Scientific Forecaster Discussion
fxus62 kmfl 170054
Area forecast discussion
National Weather Service Miami Florida
754 PM EST Tue Jan 16 2018
the forecast remains on track this evening, with just a few
isolated light showers possible over Atlantic waters overnight.
The 00z mfl sounding indicates pwats remain quite low over the
area, so do not expect shower activity on land in South Florida
overnight. No changes have been made to the forecast.
Previous discussion... /issued 627 PM EST Tue Jan 16 2018/
Aviation...current north-northeast winds 8-12kts backs north-northwest for East Coast
after 03z-06z. Next front arrives tomorrow afternoon, dry, with
just an increase in mid-upper level clouds expected. Winds
increase from the northwest 8-12kts for all sites after 15z, with
potential for gustiness later in the afternoon.
Previous discussion... /issued 336 PM EST Tue Jan 16 2018/
high pressure along the mid-Atlantic coast has been responsible
for breezy northeast winds. Despite the northeast flow, precipitable waters
remain low in the 0.50-0.75 range, and rain chances should remain
low in the short term. On Wednesday, a deep trough of low pressure
will begin to push eastward over the Appalachians. This will
drive a cold front through South Florida on Wednesday. The latest
guidance brings the front through a few hours earlier during the
day on Wednesday. The front will be mainly dry, with tropical
moisture sill located too far south of our region. As this feature
crosses South Florida, winds will once again become more
northerly. Maximum temperatures Wednesday afternoon are forecast
to be in the low to mid 70s, except near 70 in the northwest
portion of the area, as the front will reach that location sooner.
After the passage of the front late Wednesday, northerly winds
will advect a dry and cool airmass southward across our County Warning Area. Good
radiational cooling should allow temperatures to fall into the mid
30s west of Lake Okeechobee, low 40s for the rest of the
interior, and upper 40s to near 50 along the East Coast Metro
region. The latest National Weather Service forecast is about 2 degrees colder for the
low temperature on Thursday morning compared with our previous
forecast. This is because the guidance is showing colder
temperatures. This may partially be due to the earlier timing of
the frontal passage. Northerly flow will continue through the day
Thursday, keeping temperatures from rising above the mid 60s,
some 10 to 15 degrees below seasonal norms. By Friday, lower level
flow will veer to the northeast, acting to moderate temperatures
and increase moisture.
GFS and European model (ecmwf) prog surface high pressure to be located over the southeast
US and northern Florida by late Friday. The high pressure will move
eastward into the Atlantic over the weekend, acting to veer winds
easterly across South Florida. This will help deeper tropical
moisture to our south to life northward, causing rain chances to
increase by Sunday. We should have relatively weak winds by early
next week. High temps may approach 80 degrees for much of the area
next Monday. There is the slight possibility of another cold
front early next week, but models are currently showing it being a
weak one, and not causing a significant dip in temps.
Marine...gusty northeast winds of 15 to 20 knots will weaken a
little tonight and back to northerly Wednesday morning. A cold
front will pass through South Florida waters on Wednesday. Behind
the front, north winds will increase to as high as 20 to 25 knots
at times, especially late Wednesday through early Thursday. Seas
will briefly diminish tonight and Wednesday morning before
increasing late Wednesday and remaining high through Thursday. A
Small Craft Advisory will likely be needed beginning late
Wednesday for the Gulf and Atlantic waters.
Beach forecast...through early this evening, gusty northeasterly
winds will bring a high rip current risk along the Atlantic
beaches. Winds become more northerly on Wednesday, possibly
lowering the risk back down to moderate.
Preliminary point temps/pops...
West Palm Beach 58 72 47 63 / 10 10 0 10
Fort Lauderdale 61 73 49 64 / 10 10 0 10
Miami 60 73 50 64 / 10 10 0 10
Naples 54 70 41 62 / 0 0 0 0