Scientific Forecaster Discussion

NWS Discussion
			
				

Area forecast discussion 
National Weather Service Miami Florida 
819 PM EDT Sat may 25 2013 


Update... 


Gusty northeast winds continue this evening over South Florida 
with the East Coast reporting gusts up to 27 miles per hour in some locales. 
A moderate to high risk of rip currents is expected over the 
Atlantic beaches for the weekend. A very dry air mass above the 
boundary layer associated with a very strong middle level high 
pressure system over Mexico is suppressing the moisture to the 
boundary layer only. Dry conditions are expected on Sunday with 
only a minor chance of a few weak marine showers especially at 
night, when the coastal convergence is highest. No West Coast sea 
breeze is expected to form on Sunday. High temperatures on Sunday 
will range from the low to middle 80s along the East Coast to the low 
90s from Naples to Mainland Monroe. For Monday, a fast moving 
shower moving from NE to SW into the Gulf waters cannot be ruled 
out late in the day. An increase in moisture and diurnal 
convection is expected after Monday. 


&& 


Previous discussion... /issued 725 PM EDT Sat may 25 2013/ 


Aviation... 
high pressure centered over the southeast United States will keep South 
Florida in a mostly dry NE/east wind flow through the day on Sunday. 
Only issue is winds which will gust to around 20 knots during the 
day. VFR conditions expected with partly to mostly clear skies. 


Molleda 


Previous discussion... /issued 236 PM EDT Sat may 25 2013/ 


Short term (tonight-Monday night)... 
plenty of dry air along with rising upper heights in the wake of the 
frontal boundary that passed through today will lead to more of a 
suppressed environment through the remainder of the weekend. Model 
time heights/soundings around the local area reflect this and 
generally indicate most of the moisture remaining confined within 
the lower 4 kft underneath a strong subsidence inversion. 
Precipitable water values are forecast to steadily drop tonight and 
bottom out just above half of an inch Sunday before steadily 
trending back up into the upcoming week. However...moderate 
northeasterly winds and plenty of low-level moisture may allow for a 
few shallow brief showers to develop over the adjacent Atlantic 
waters and spread ashore through the remainder of the 
weekend...especially through the overnight and early morning hours. 
This lines up well with the latest WRF solutions...which indicate a 
few light showers developing and spreading ashore over the northern 
areas later tonight into Sunday. On Monday...deep easterly flow up 
to around 18 kft along with increasing moisture may lead to few 
showers developing inland and toward the Gulf Coast areas through 
the afternoon/evening hours. However...in the absence of a Gulf 
Coast sea breeze due to the moderate easterly flow in place along 
with the middle-level dry air...mainly brief showers will be 
anticipated. Along the East Coast...temperatures will remain 
slightly below normal each day. 85/ag 


Long term (tuesday-friday)... 
additional moisture is forecast to enter the region early next week 
as a middle to upper level trough is forecast to deepen in the eastern 
Gulf with a chance of showers and thunderstorms returning to the 
region. There is some consensus amongst the model guidance that 
deeper layered tropical moisture and a deepening of the middle to upper 
level trough could occur around middle-week and persist for a couple of 
days with more widespread convection possible. Will have to wait and 
see if future guidance persists with these synoptic features. 


Blowing dust 


Marine... winds and seas will quickly increase through the 
remainder of the weekend in the wake of a weak frontal boundary as 
high pressure builds over the region. Although advisory level 
winds and seas are not anticipated at this time...mariners 
operating small craft are encouraged to exercise caution...mainly 
over the Atlantic waters this weekend. 


At the East Coast beaches...strong rip currents will be likely by 
Sunday due to moderate onshore winds and building surf. 


Fire weather... 
despite the drier air that is forecast to spread over the area 
through the remainder of the weekend and into the upcoming 
week...relative humidities are forecast to remain above critical 
levels each day. Easterly winds will become gusty through the 
afternoon periods. 


&& 


Preliminary point temps/pops... 
West Palm Beach 72 82 73 83 / - 10 10 10 
Fort Lauderdale 76 85 77 86 / - 10 20 10 
Miami 75 84 75 85 / - 10 20 20 
Naples 69 91 69 91 / - 10 10 20 


&& 


Mfl watches/warnings/advisories... 
Florida...none. 
Am...none. 
GM...none. 
&& 


$$ 


Discussion/marine/fire...71/je 
aviation/radar...59/rm