Southeast Florida Weather Outlook (2-28-14)

Beach_Image100

 

Analysis

 

For southeast Florida weather, during the overnight hours, it was cloudy.  There were periods of rain/showers.  There was also fog in some areas.

Animated Radar with Satellite Overlaid (Early Morning)

Animated Radar with Satellite Overlaid (Early Morning)

 

Overnight lows were mostly in the upper 50’s to the middle 60’s.  Some areas further inland (mainly in Palm Beach and Broward Counties) had minimums in the middle 50’s.  Winds were light mostly out of the northwest and north with periods of calm winds.

During the day, the main band of rain moved offshore shortly after daybreak.  It remained mostly cloudy with gradual clearing taking place from generally northwest to southeast.  By early afternoon, most areas had become sunny to partly sunny. The rain area had moved well offshore into the western Bahamas.

Animated Radar with Satellite Overlaid (Afternoon)

Animated Radar with Satellite Overlaid (Afternoon)

 

Daytime maximum temperatures ranged from near 70 to the upper 70’s.  Winds were mostly west and northwest at 5 – 15 mph.

Late this afternoon, the front that moved through on Friday was located in the Florida Straits as a stationary front extending east into the western Bahamas and southwest into western Cuba. A weak surface High is located in the northeast Gulf of Mexico.  A trough is located to the east of Florida helping to keep surface winds more northerly.

Satellite Imagery Overlaid with Fronts (Late Afternoon)

Satellite Imagery Overlaid with Fronts (Late Afternoon)

 

Drier air was filtering in behind the front with humidity levels falling to the 40’s and 50’s percent range for most of the region.

Relative Humidity/Steering Flow – Low Level (Afternoon)

Relative Humidity/Steering Flow –
Low Level (Afternoon)

 

With the drier air and cooler temperatures, dewpoint temperatures were in the 40’s and 50’s.  With even drier and cooler air in north Florida, dewpoint temperatures were in the 20’s and 30’s.

Surface Dewpoint Temperatures (Afternoon)

Surface Dewpoint Temperatures (Afternoon)

 

Winds will remain more northerly overnight rather than veering quickly to the northeast.  And under clear skies with drier air and light winds, it will be a good night for radiational cooling.  Overnight lows will be generally in the 50’s to low 60’s.

 

Forecast

 

Short Range Forecast:

For tonight, it will be clear to partly cloudy.  Lows will be in the low 50’s to middle 50’s inland to upper 50’s to low 60’s at the metro and coastal areas.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the upper 40’s to around 50.  Some areas near the immediate coastal areas of Miami-Dade County may see lows in the middle 60’s.

Winds will be north to north northeast at 6 – 12 knots. Seas will be 2 – 3 feet except 2 – 4 feet in Palm Beach County.  Intracoastal waters and Biscayne Ba will have a light chop.

 

At the middle and upper levels, the axis of the trough will move east of Florida putting the southeast U.S. and Florida in a northwest flow aloft.  A trough approaches the west coast.  In between the two troughs, a ridge builds into the central U.S. from the southern Gulf of Mexico/western Caribbean (at times strengthening to 588 DM).  Locally, heights will rise to middle 580’s DM by Sunday. In the next few days, the trough from the west coast propagates eastward approaching the eastern U.S. As this occurs, the High shifts eastward into the western Caribbean/near Cuba.  In advance of the trough, the flow aloft over becomes southwesterly across the eastern U.S. including Florida.  Behind the trough, the flow becomes rather zonal.

500 mb (Mid-Level) Flow 3-1-14

500 mb (Mid-Level) Flow 3-1-14

500 mb (Mid-Level) Flow 3-3-14

500 mb (Mid-Level) Flow 3-3-14



As the axis of the trough moves east resulting with a more northwest flow aloft, this will allow for the stationary front to move further southeast  away from the region and well into Cuba.

WPC Forecast 2-28-14 (7:00 pm)

WPC Forecast 2-28-14 (7:00 pm)

 

Drier air will continue to filter in with the flow aloft becoming northwest.  This will set the stage for a pleasant weekend with sunny skies.  PWAT (Precipitable Water) will fall to below normal levels and range between ½” and 1” for the weekend resulting in nil chance of showers.  Afternoon temperatures will be seasonably warm with mild nighttime temperatures. Temperatures will be warming though.

GFS Extended MOS Forecast

GFS Extended MOS Forecast

 

With a building surface High to the north and become established in the Atlantic over the weekend, winds will veer to the northeast and east.

GFS Wind & Precip Forecast Model 2-28-14(12z) at 048 Hours

GFS Wind & Precip Forecast Model 2-28-14(12z) at 048 Hours

 

Winds may freshen up somewhat later on Saturday into Sunday which may raise the risk of rip currents.

There will be little change for the beginning of next week other than winds becoming more southeasterly and south as a front advances into the southeast U.S.

WPC Forecast 3-3-14 (7:00 am)

WPC Forecast 3-3-14 (7:00 am)

 

With the winds becoming more southeast and south, there will be some increase in moisture which may lead to the development of some showers.

 

For Saturday, it will be sunny.  Highs will be in the upper 70’s to the middle 80’s.  Lows Saturday night will be around 60 to the middle 60’s.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the middle and upper 50’s.  Some areas near the immediate coastal areas of Miami-Dade and Broward Counties may see lows near the upper 60’s.

Winds will be northerly at 9 – 14 knots becoming northeast Saturday night at 11 – 16 knots.  Seas will be 2 – 4 feet becoming 2 – 5 feet Saturday night.  Intracoastal waters and Biscayne Bay will have a light chop becoming moderate chop Saturday night.

For Sunday, it will be sunny.  Highs will be around 80 to the low 80’s.  Some areas in the interior may reach the middle 80’s.  Lows Sunday night will be in the low 60’s to upper 60’s.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the upper 50’s to around 60.   Some areas near the immediate coastal areas of Miami-Dade County may see lows near 70.

Winds will be east northeast at 9 – 16 knots becoming east northeast and east at 5 – 12 knots Saturday night.  Seas will be 2 – 5 feet decreasing to 2 – 4 feet Sunday night.  Intracoastal waters and Biscayne Bay will have a moderate chop becoming light chop Sunday night.

With increased onshore winds, there may be a slight to possibly moderate risk of rip currents.  An update via twitter will be sent out as warranted on Sunday with the rip current risk level.

For Monday, it will be partly sunny to partly cloudy.  Highs will be in the low to middle 80’s.  Some areas in the interior may reach the upper 80’s while some of the immediate coastal areas (mainly in Miami-Dade County) may be around 80.  Lows Monday night will be low 60’s to upper 60’s.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the upper 50’s to around 60.

Winds will be south and south southeast 5 – 9 knots becoming south southwest to variable at 5 – 8 knots.  Seas will be 2 – 4 feet becoming 2 – 3 feet.  Intracoastal waters and Biscayne Bay will have a light chop becoming smooth in the southern portions (Miami-Dade and Broward Counties).

 

Medium Range Outlook:

In the middle and upper levels, by early-middle next week, the trough will be over the eastern half of the U.S. with the High having been shunted eastward into the Atlantic near Cuba/Central Bahamas. As this occurs, heights will lower to around the 580 – low 580’s DM range.  A southwest flow aloft continues over the southeast U.S. and Florida.  Broad ridging moves into the western U.S.

500 mb (Mid-Level) Flow 3-4-14

500 mb (Mid-Level) Flow 3-4-14

 

With little support (flow aloft parallels the front), the front will make slow southward progress early next week and weaken as it does so.

WPC Forecast 3-4-14 (7:00 am)

WPC Forecast 3-4-14 (7:00 am)

 

The front will reach south Florida by the middle of next week in a highly weakened state.  It will dissipate near the region.

WPC Forecast 3-5-14 (7:00 am)

WPC Forecast 3-5-14 (7:00 am)

 

Rain chances look sparse into mid-week with the best chance in the northern region.

GFS Wind & Precip Forecast Model 2-28-14(12z) at 129 Hours

GFS Wind & Precip Forecast Model 2-28-14(12z) at 129 Hours

 

 

Extended Range Outlook:

At the middle and upper levels, the trough slides further east while sharpening with a possible Low taking shape over the southeast U.S.  It also appears that the flow may split between the northern and southern streams – at least for a period of time.  Heights will lower over the region to around 570 DM – 576 DM range.  Broad ridging continues near the western U.S/west coast.

500 mb (Mid-Level) Flow 3-7-14

500 mb (Mid-Level) Flow 3-7-14

 

A surface Low pressure is forecast to develop in the Gulf of Mexico toward the end of next week with an attending cold front.

WPC Forecast 3-6-14 (7:00 am)

WPC Forecast 3-6-14 (7:00 am)

 

The Low is forecast to move northeast to off the southeast U.S. coast by the end of next week with the cold front moving through south Florida during that time.

WPC Forecast 3-7-14 (7:00 am)

WPC Forecast 3-7-14 (7:00 am)

 

The GFS model depicts an area of showers to accompany the system.

GFS Wind & Precip Forecast Model 2-28-14(12z) at 177 Hours

GFS Wind & Precip Forecast Model 2-28-14(12z) at 177 Hours

 

Although, it is too early to determine the potential for thunderstorms, with the surface Low well south and fairly deep, there is that potential.   Much of it will depend on the timing with the passage of the activity (daytime heating or the lack of it), the depth and position of the surface Low, shear, temperatures aloft, etc. With these types of systems, spring is notorious for thunderstorm development for this region.

Looking further out, the GFS indicates another frontal passage around the 10th of March.

GFS Wind & Precip Forecast Model 2-28-14(12z) at 240 Hours

GFS Wind & Precip Forecast Model 2-28-14(12z) at 240 Hours

 

At this time, it looks to be a dry passage.  The GFS model has been showing various levels of cooling with this frontal system.  At various runs, it has indicated minimums as low as in the 40’s.  But as we have seen before, there can be significant run to run and day to day variations.  For now will go with the idea that minimum temperatures will be in the 50’s.  This is still 10 days out and there is plenty of time to monitor.

The GFS then shows another frontal passage just before the middle of the month.  This front appears to have some showers associated with it as there is better moisture return with this system.

GFS Wind & Precip Forecast Model 2-28-14(12z) at 312 Hours

GFS Wind & Precip Forecast Model 2-28-14(12z) at 312 Hours

 

With the succession of frontal passages, this may be an extended period of cooler weather.

 

These are long range forecast and a lot can happen and are subject to large errors.

 

Climate Index Indicators:

The PNA index current phase is weakly positive/near neutral range.  It is forecast remain nearly neutral for the next few days.  It is then forecast to trend toward a moderate positive phase in the latter portion of the first week of March and continues positive into the middle of March while possibly showing a weakening signal.

Forecast PNA Index 2-21-14 (12z) (source: raleighwx.americanwx.com)

Forecast PNA Index 2-21-14 (12z)
(source: raleighwx.americanwx.com)

 

This suggests initially a low amplitude (more zonal – west to east flow) pattern for the next few days.   As the positive signal strengthens into the first week of March, this suggests a trough becomes established over the eastern U.S. while a ridging occurs over the western U.S.  With the index remaining positive, this pattern looks to remain in place through the middle of March with some possible de-amplification taking place as the positive signal weakens somewhat.

Troughs are usually associated with cooler/colder conditions while ridges are associated with warmer conditions. During the neutral/near neutral phase, there typically is less amplitude to the flow.  Weather systems will generally track west to east and in a high amplitude setup, weather systems can dive out of the northern latitudes (bring cold air) well southward or weather systems from the south (bring warm air) well northward.

The AO (Arctic Oscillation) index is currently in a weak to moderate negative phase.  It is forecast to trend toward the neutral range into the first week of March with some members trending weakly negative again while other members trend it positive into the middle of March.

Forecast AO Index 2-21-14 (12z) (source: raleighwx.americanwx.com)

Forecast AO Index 2-21-14 (12z)
(source: raleighwx.americanwx.com)

 

A positive phase of the index would tend to “bottle” up the colder air in the northern Latitudes and is less likely to dip far southward.    A negative phase would have the tendency for allowing cold air to spill further southward into the U.S. from the northern latitudes.  The current negative phase is indicative of the very cold Arctic outbreak that is occurring over portions of the U.S.  Cold temperature records are anticipated at some locations.

The NAO (North Atlantic Oscillation) has been largely in the neutral/weakly positive range for an extended period of time.  It is forecast to trend slightly stronger positive into the first week of March.  Some members showing a trend toward weak negative phase around the second week of March before returning back to a more neutral phase toward the middle of the month.

Forecast NAO Index 2-21-14 (12z) (source: raleighwx.americanwx.com)

Forecast NAO Index 2-21-14 (12z)
(source: raleighwx.americanwx.com)

 

A negative phase tends to lead to cold air intrusion for the eastern portion of the U.S.

 

For further reading regarding these indices and others used, click here.

 

Below is the forecast 500 mb pattern for the 6 – 10 day and 8 – 14 day period.  The graphics indicate that on average for the 6 – 10 day period, there will be a broad trough in the eastern U.S. with a ridge in the western U.S.  The average pattern for the 8 – 14 day period indicates that there is little overall change other than the trough will shift a little further eastward into the eastern U.S and possibly flattening out a little.  Ridging continues in the western U.S.

Average 500 mb Flow 6 – 10 Day Period

Average 500 mb Flow 6 – 10 Day Period

Average 500 mb Flow 8 – 14 Day Period

Average 500 mb Flow 8 – 14 Day Period



Below is the forecast 6 – 10 day and 8 – 14 day temperature outlook. The 6 – 10 Day outlook indicates higher probability of below normal temperatures for the central and eastern U.S. except for south Florida where temperatures are forecast to be normal.  The western U.S. will have a higher probability of above normal to normal temperatures.  In the 8 – 14 day period, there is little change except for some moderation on the probabilities of cooler air and increased likelihood for most of Florida.

 

6 – 10 Day Temperature Outlook

6 – 10 Day Temperature Outlook

8 – 14 Day Temperature Outlook

8 – 14 Day Temperature Outlook



Stay updated. Visit the website to check for constant updates via twitter or follow on twitter @Theweathercentr.

 

Southeast Florida Weather Outlook (2-27-14)

Beach_Image100

 

Analysis

 

For southeast Florida weather, during the overnight hours, it was mostly cloudy.  A band of showers moving southeast affected portions of the area.  Other showers were in the Florida Straits and offshore in the Atlantic.  Other showers were further north in central Florida.

Animated Radar with Satellite Overlaid (Early Morning)

Animated Radar with Satellite Overlaid (Early Morning)

 

Southwest winds of 5 – 15 mph kept temperatures from falling much overnight.  Lows were rather uniform with temperatures from the middle 60’s to low 70’s.

During the day, the band of showers continued moving southeast and into the Florida Straits during the morning.  It was cloudy for the early portion of the day with some breaks occurring.  For portion of the day, it became partly sunny to partly cloudy.  Later in the afternoon, clouds were on the increase.  An area of rain in the eastern Gulf of Mexico was moving eastward while the areal coverage was increasing.

False radar returns in the animation below near southeast Florida are attributable to CHAF.

Animated Radar with Satellite Overlaid (Afternoon)

Animated Radar with Satellite Overlaid (Afternoon)

 

High temperatures were mostly in the middle 70’s to around 80 with some areas well inland in Palm Beach and Broward Counties remaining in the low 70’s.  Winds became mostly light northwesterly.

Late this afternoon, the weak cold front was located across the southern tip of Florida.  Abundant clouds were along and behind the front.

Satellite Imagery Overlaid with Fronts (Late Afternoon)

Satellite Imagery Overlaid with Fronts (Late Afternoon)

 

There was a wide variation of dewpoint temperatures across the state today.  In south Florida, closer to the front, dewpoint temperatures were in the 50’s and 60’s, while in north Florida where there were cooler temperatures and drier air, dewpoint temperatures ranged from the 20’s to the 40’s.

Surface Dewpoint Temperatures (Afternoon)

Surface Dewpoint Temperatures (Afternoon)

 

Below is the low level moisture level depicting much drier air over northern Florida.  Note that area of higher moisture in the southeast Gulf of Mexico.  This is where the area of rain was developing.

Relative Humidity/Steering Flow – Low Level (Afternoon)

Relative Humidity/Steering Flow –
Low Level (Afternoon)

 

An upper level feature will be moving across the region overnight.  The combination of this feature, the front nearby and sufficient moisture will lead to increasing chance of rain/showers overnight and into early Friday.

 

 

Forecast

 

Short Range Forecast:

For tonight, it will be cloudy.  There will be periods of rain/showers.  Lows will be in the upper 50’s to the middle 60’s.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the middle 50’s.

Winds will be north northeast at 8 – 13 knots.  Seas will be 2 – 4 feet.  Intracoastal waters and Biscayne Bay will have a light chop.

 

At the middle and upper levels, in the next few days, a trough located in the eastern U.S. will rotate eastward into the western Atlantic.  This will transition the flow from the west-southwest to west/northwest over the southeast U.S. and Florida.  A Low approaching the U.S. west coast weakens and opens up as a trough and moves into the west-central U.S.  In between these two troughs, a High will bulge north and east from the Caribbean.  Heights will rapidly rise from around mid-570’s DM this morning’s soundings to around the mid-580’s DM by Sunday.

500 mb (Mid-Level) Flow 2-28-14

500 mb (Mid-Level) Flow 2-28-14

500 mb (Mid-Level) Flow 3-2-14

500 mb (Mid-Level) Flow 3-2-14



With the axis of the trough is still to the west (flow aloft southwest), the weakening front has been moving slowly southward across south Florida during the day.  There was little in the way of surface convergence to initiate shower development.  The front will move into the Florida Straits/near Cuba later tonight.  As indicated above, an upper level feature will move across Florida overnight bringing an increasing chance of rain/showers.

WPC Forecast 2-28-14 (1:00 am)

WPC Forecast 2-28-14 (1:00 am)

 

The front will then become nearly stationary on Friday.

WPC Forecast 2-27-14 (7:00 pm)

WPC Forecast 2-27-14 (7:00 pm)

 

As the axis of the trough moves to the east by later Friday into Saturday (northwest flow aloft), the front will move further southward to well south into Cuba on Saturday.

High pressure builds in behind the front and becomes established in the Atlantic during the weekend.

GFS Wind & Precip Forecast Model 2-27-14(12z) at 075 Hours

GFS Wind & Precip Forecast Model 2-27-14(12z) at 075 Hours

 

This will provide with a northeast winds veering more easterly and possibly east southeast by later on Sunday at light to moderate speeds.  As winds become more onshore, the risk of rip currents may increase.

The weekend will be sunny, pleasant and seasonably warm.  Drier air with PWAT (Precipitable Water) falling to between ½” to 1” will prevail.  Temperatures will be slowly moderating with highs temperatures generally in the upper 70’s to low 80’s with lows mostly in the 60’s.

 

For Friday, it will be it will be cloudy but decreasing as the day progresses from north to south becoming clear to partly cloudy by Friday night.  Rain/showers early will diminish as the day progresses. Highs will be in the middle and upper 70’s.  Lows Friday night will be around 60 to the middle 60’s.   Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the middle and upper 50’s. Some areas near the immediate coastal areas of Miami-Dade Counti may see lows in the upper 60’s.

Winds will be north northeast at 9 – 14 knots diminishing to 6 – 12 knots Friday night.  Seas will be 2 – 4 feet diminishing to 2 – 3 feet Friday night.  Intracoastal waters and Biscayne Bay will have a light chop except moderate chop in Palm Beach County during the day.

For Saturday, it will be sunny.  Highs will be in the upper 70’s to low 80’s.  Lows Saturday night will be in the low 60’s to upper 60’s.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the upper 50’s to around 60.

Winds will be north and north northeast at 7 – 12 knots becoming northeast 8 – 14 knots Saturday night.  Seas will be 2 – 4 feet.  Intracoastal waters and Biscayne Bay will have light chop to moderate chop Saturday night in the southern portions (Miami-Dade and Broward Counties).

As winds become more onshore, there may be a slight risk of rip currents.  An update via twitter will be sent out on Saturday as warranted with the rip current risk level.

For Sunday, it will be sunny.  Highs will be around 80 to the low 80’s.  Some of the immediate coastal areas may see highs around the upper 70’s.  Lows Sunday night will be in the low 60’s to upper 60’s.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the upper 50’s to around 60.  Some areas near the immediate coastal areas of Miami-Dade and Broward Counties may see lows around 70.

Winds will be east northeast at 6- 13 knots becoming east and east southeast at 6- 12 knots.  Seas will be 2 – 4 feet decreasing to 2 – 3 feet Sunday night.  Intracoastal waters and Biscayne Bay will have a light to moderate chop becoming light chop Sunday night.

With winds more onshore, there may be a slight risk of rip currents.  An update via twitter will be sent out on Sunday as warranted with the rip current risk level.

 

Medium Range Outlook:

In the middle and upper levels, by early next week, the High will be centered near Cuba.  The trough in the western U.S. is traverses eastward toward the eastern U.S. which shunts the High eastward into the Atlantic.  Between the trough to the west and High to the east, there is a broad southwest flow across the eastern U.S. including Florida.  Ridging approaches the west coast of the U.S.

500 mb (Mid-Level) Flow 3-3-14

500 mb (Mid-Level) Flow 3-3-14

 

Mostly sunny and dry weather will continue into early next week.  PWAT remains below 1” into Monday before gradually increasing.

Early next week, a frontal system will move into the southeast U.S.

WPC Forecast 3-3-14 (7:00 am)

WPC Forecast 3-3-14 (7:00 am)

 

This will push the surface High further east into the Atlantic causing winds to veer more to the southeast allowing for moisture to slowly increase.

As the front encounters the upper High and the flow aloft parallels the frontal system, it will lose steam with its forward progression and weakens.  On Tuesday, it will be moving into central Florida.

WPC Forecast 3-4-14 (7:00 am)

WPC Forecast 3-4-14 (7:00 am)

 

Extended Range Outlook:

At the middle and upper levels, the trough continues near the eastern U.S. with little overall movement.  Southwest flow aloft continues over the southeast U.S. and Florida.  A ridge has propagated into the western U.S.

500 mb (Mid-Level) Flow 3-6-14

500 mb (Mid-Level) Flow 3-6-14

 

The front limps into south Florida around the middle of next week.

WPC Forecast 3-5-14 (7:00 am)

WPC Forecast 3-5-14 (7:00 am)

 

It appears that a building surface High to the north will bridge the front with winds becoming northeasterly.  Some showers will accompany the front across south Florida. With general northeast winds, activity may be more focused on the western side of south Florida although showers will also stream in from the Atlantic.

GFS Wind & Precip Forecast Model 2-27-14(12z) at 153 Hours

GFS Wind & Precip Forecast Model 2-27-14(12z) at 153 Hours

 

The pressure gradient may tighten up causing winds to increase.  This may lead to deteriorating boating and marine conditions.

 

Toward the end of the week, a low pressure system will be developing/organizing over the Gulf of Mexico.

WPC Forecast 3-6-14 (7:00 am)

WPC Forecast 3-6-14 (7:00 am)

 

A band of showers will be accompanying this system as it moves across Florida toward the end of next week.

GFS Wind & Precip Forecast Model 2-27-14(12z) at 183 Hours

GFS Wind & Precip Forecast Model 2-27-14(12z) at 183 Hours

 

GFS model currently is showing some decent parameters for the possibility of thunderstorms. However, other elements will have to come together such as timing of the frontal passage, depth/position of the surface Low, etc.  As usual, this far out, a lot can change.

Looking at longer range, the GFS model indicates that a long wave trough may become established over the eastern U.S. in the 8 – 10 day period. This may allow for a couple of other fronts to move through the region well into the extended period.  This may bring in below normal temperatures for the region.

The GFS model shows frontal system to move through the region around the following weekend.

GFS Wind & Precip Forecast Model 2-27-14(12z) at 228 Hours

GFS Wind & Precip Forecast Model 2-27-14(12z) at 228 Hours

 

This appears to be a dry frontal passage

The GFS indicates another frontal system just before the middle of the month.

GFS Wind & Precip Forecast Model 2-27-14(12z) at 324 Hours

GFS Wind & Precip Forecast Model 2-27-14(12z) at 324 Hours

 

As mentioned earlier, this is a long way out and is susceptible to significant errors as a lot can happen.

 

Stay updated. Visit the website to check for constant updates via twitter or follow on twitter @Theweathercentr.

 

Southeast Florida Weather Outlook (2-26-14)

Beach_Image100

 

Analysis

 

For southeast Florida weather, during the overnight hours, it was mainly clear to partly cloudy.  Fog developed over most of the interior of south Florida.  This prompted the issuance of a  Dense Fog Advisory for almost all of south Florida.  The only areas excluded from the advisory were the metro and coastal areas of Miami-Dade and Broward Counties.

Animated Radar with Satellite Overlaid (Early Morning)

Animated Radar with Satellite Overlaid (Early Morning)

 

Overnight minimum temperatures were in the low 60’s to upper 60’s with areas further inland (primarily in Palm Beach and Broward Counties) in the upper 50’s to around 60.  Winds were generally light offshore with periods of calm.

During the day, it was mainly sunny.  By later in the afternoon, high clouds from the tops of convection being blown by upper level winds off toward the southeast was affecting the region.  Showers were well to the north of the area.

False radar returns in the animation below near the Florida Keys are attributable to CHAF.

Animated Radar with Satellite Overlaid (Afternoon)

Animated Radar with Satellite Overlaid (Afternoon)

 

High temperatures were mostly in the low to middle 80’s with some areas reaching the upper 80’s.  Winds were out of the southwest and west at around 15 mph and gusty.  A southward moving frontal system was located across north central Florida late this afternoon.

Some drier air lingered at the low levels over the area.

Relative Humidity/Steering Flow – Low Level (Afternoon)

Relative Humidity/Steering Flow –
Low Level (Afternoon)

 

This helped to keep dewpoint temperatures mostly in the 60’s with middle and upper 50’s in portions of Palm Beach County.  Higher dewpoint temperatures of around 70 to the lower 70’s was evident in the southeast Gulf of Mexico where there was a higher level of moisture.

Surface Dewpoint Temperatures (Afternoon)

Surface Dewpoint Temperatures (Afternoon)

 

 

Forecast

 

Short Range Forecast:

For tonight, it will be cloudy.  There may be some isolated to widely scattered showers later.  Lows will be in the middle 60’s to near 70.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows around 60 to the low 60’s.

Winds will be west southwest at 8 – 13 knots except 12 – 18 knots in the Gulf Stream. Seas will be 2 – 4 feet.  Intracoastal waters and Biscayne Bay will have a light chop.

 

At the middle and upper levels, a zonal to west-southwest flow aloft will take place initially over the southeast U.S. including Florida as a trough rotates into the eastern U.S.  Ridging continues in the western U.S. with a Low approaching the U.S. west coast. The ridge in the Caribbean continues well to the south.  The trough will amplify southward in the next few days with heights falling into the mid 570’s DM range from around 580 DM.  By Saturday, the trough will have propagated to the east of Florida while sharpening as the ridge in the Caribbean bulges northward leading to increasing heights over the region. Winds aloft will transition briefly to the northwest over the region bringing in drier continental air.  In the western U.S., the Low will have opened up as a trough as it approaches the west coast.

500 mb (Mid-Level) Flow 2-27-14

500 mb (Mid-Level) Flow 2-27-14

500 mb (Mid-Level) Flow 3-1-14

500 mb (Mid-Level) Flow 3-1-14



The reinvigorated cold front will move into south Florida by early Thursday and be in the Florida Straits by Thursday evening.

WPC Forecast 2-27-14 (7:00 am)

WPC Forecast 2-27-14 (7:00 am)

WPC Forecast 2-27-14 (7:00 pm)

WPC Forecast 2-27-14 (7:00 pm)



The front will then become nearly stationary in the Florida Straits on Friday.

WPC Forecast 2-28-14 (7:00 am)

WPC Forecast 2-28-14 (7:00 am)

 

PWAT (Precipitable Water) will be in the 1 ½” – 1 ¾” range for Thursday into Friday which is well above normal for this time of year.  With the presence of the front and higher PWAT, showers are forecast for the region.  Although instability is rather lacking, with surface converge due to the front and high PWAT values plus daytime heating, may lead to widely isolated to widely scattered thundershowers. The activity should continue into early Friday before tapering off.

GFS Wind & Precip Forecast Model 2-26-14(12z) at 030 Hours

GFS Wind & Precip Forecast Model 2-26-14(12z) at 030 Hours

GFS Wind & Precip Forecast Model 2-26-14(12z) at 048 Hours

GFS Wind & Precip Forecast Model 2-26-14(12z) at 048 Hours



Thursday night/Friday morning may be rather cool and rainy. There may be some low stratus clouds reducing visibilities.

Today’s models indicate that the front will move through more cleanly and there will be less in the way of residual showers on Friday.

 

For Thursday, it will be it will be cloudy.  There will be increasing coverage of showers becoming likely and continue into Thursday night.  There may be isolated thundershowers in the afternoon. Highs will be in the middle 70’s to low 80’s, but may be lower if clouds and showers move in earlier.  Lows Thursday night will be in the upper 50’s to middle 60’s.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the low to middle 50’s.

Winds will be west and northwest becoming north northwest in the afternoon in Palm Beach County at 7 – 14 knots.  Thursday night, winds will be north to north northeast at 9 – 15 knots.  Seas will be 2 – 4 feet.  Intracoastal waters and Biscayne Bay will have a light chop.

For Friday, it will be cloudy but diminishing from north to south as the day the progresses.  There will be a good chance of showers that will be decreasing from north to south.  Highs will be in the middle and upper 70’s.  Lows Friday night will around 60 to the middle 60’s.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the middle and upper 50’s. Some areas near the immediate coastal areas of Miami-Dade County may see lows in the upper 60’s.

Winds will be northeast to northeast at 6 – 11 knots becoming northeast 8 – 13 knots Thursday night in the southern areas (Miami-Dade and Broward Counties).  Seas will be 2 – 4 feet.  Intracoastal waters and Biscayne Bay will have a light chop becoming moderate chop Friday night in the southern portions.

As winds become more onshore, there may be a slight risk of rip currents.  An update via twitter will be sent out on Friday as warranted with the rip current risk level.

For Saturday, it will be sunny.  Highs will be around 80 to the low 80’s.  Lows Saturday night will be in the low 60’s to upper 60’s.  Some areas well inland (especially in Palm Beach and Broward Counties) may see lows in the upper 50’s to around 60.  Some areas near the immediate coastal areas may see lows around 70.

Winds will be north northeast and northeast becoming northeast and east northeast Saturday night at 6 – 13 knots becoming 8 – 15 knots Saturday night.  Seas will be 2 – 4 feet.  Intracoastal waters and Biscayne Bay will have a moderate chop except light chop in Palm Beach County.

With increasing onshore winds, there may be a slight to possibly moderate risk of rip currents.  An update via twitter will be sent on Saturday as warranted with the rip current risk level.

 

Medium Range Outlook:

In the middle and upper levels, the trough has lifted out and the High in the Caribbean expands north and east.  The High becomes centered near Cuba.  Heights rise rapidly into the middle 580’s DM.  The trough  that was near the west coast of the U.S. has progressed into the western U.S.  The flow aloft becomes more southwest over the southeast U.S. including Florida.

500 mb (Mid-Level) Flow 3-2-14

500 mb (Mid-Level) Flow 3-2-14

 

Over the weekend, a surface High builds in from the north and becomes established in the Atlantic. Winds will veer to the northeast and then east during the weekend.  The building High will help to push the moisture from the front in the Florida Straits further away southward.

GFS Wind & Precip Forecast Model 2-26-14(12z) at 099 Hours

GFS Wind & Precip Forecast Model 2-26-14(12z) at 099 Hours

 

This will bring dry and pleasant weather over the region which will continue into the early part of next week.  PWAT decrease to less than 1” over the weekend and at times below ⅔”.  After a brief cool down, temperatures will warm to above normal.

GFS Extended MOS Forecast

GFS Extended MOS Forecast

 

As a frontal system moves toward the southeast U.S. late in the weekend, the High in the Atlantic shifts further eastward.  This will result in winds veering more to the east and southeast.  As the pressure gradient tightens up between the two features, winds may freshen some.  This may lead to some deteriorating boating conditions.  Additionally with increasing onshore winds, the risk of rip currents may increase.

 

Extended Range Outlook:

At the middle and upper levels, the High near Cuba moves north and east into the Atlantic as a trough makes slow eastward progression in the central U.S.  toward the eastern U.S.  As the trough moves east, a ridge moves into the western U.S. The southwest flow aloft continues over the southeast U.S. and Florida.

500 mb (Mid-Level) Flow 3-6-14

500 mb (Mid-Level) Flow 3-6-14

 

An interesting facet is that models have been latching on to the idea that there will be some sort of tropical development in the western Pacific and how it interacts with upstream systems as it gets picked up by the westerlies.  This may complicate forecast models as to how this feature will be handled which may lead to large run to run and day to day variances.

A front is forecast to move into north Florida around the early-middle of next week.

WPC Forecast 3-4-14 (7:00 am)

WPC Forecast 3-4-14 (7:00 am)

 

The front is forecast to continue moving southeast through the state and moving off the southeast Florida coast around the middle of next week.

WPC Forecast 3-5-14 (7:00 am)

WPC Forecast 3-5-14 (7:00 am)

 

The GFS model shows showers will accompany the front as it moves down the state.

GFS Wind & Precip Forecast Model 2-26-14(12z) at 153 Hours

GFS Wind & Precip Forecast Model 2-26-14(12z) at 153 Hours

GFS Wind & Precip Forecast Model 2-26-14(12z) at 168 Hours

GFS Wind & Precip Forecast Model 2-26-14(12z) at 168 Hours



There has been run to run and day to day variability with minimum temperature forecast.  The forecast will hinge on the timing of the passage of the frontal system and how quickly winds veer to the northeast.  Current thinking is that minimums will be mostly in the 50’s and 60’s.

Looking further out, the GFS model is showing the potential of another frontal system moving through the region about five days later (around March 10).

GFS Wind & Precip Forecast Model 2-26-14(12z) at 288 Hours

GFS Wind & Precip Forecast Model 2-26-14(12z) at 288 Hours

 

Stay updated. Visit the website to check for constant updates via twitter or follow on twitter @Theweathercentr.

 

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