Area Forecast Discussion
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826 FXUS62 KTAE 181045 AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 645 AM EDT Fri Apr 18 2014 .Near Term [Through Today]... The 03 UTC regional surface analysis showed a rather wavy, east-west oriented frontal boundary from central FL through the Gulf of Mexico. There was no closed surface low yet, but all of the global models insist that one will form in the northern Gulf by around dawn. Vapor imagery and upper air data showed an approaching potent trough over TX, though a preceding short wave trough appeared to be translating northeastward over the FL Panhandle. It`s this initial short wave trough that is associated with the massive blowup of deep moist convection over the eastern Gulf of Mexico early this morning. Widespread rain from these MCSs has spread over most of our forecast area, and we expect this will continue throughout the day. With precip water values 50 to 100% above climo, rain rates will occasionally be very high, so we will leave our Flood Watch up and unchanged for our entire forecast area. The global model consensus brings the surface low near Apalachicola by late afternoon. Although there will be a lot of rain and clouds today, the mean of the Convection Allowing Model (CAM) forecast SBCAPE is in the 500- 1000 J/kg range this afternoon around Cross City and Perry. Given the expected 0-1 km bulk shear magnitude will be around 30 KT in that area, it`s reasonable to be concerned about isolated, low-topped supercells- with damaging wind gusts or perhaps even a brief tornado. Elsewhere we think that thunderstorms will be elevated enough to limit vertical mixing, though the low level winds are strong enough that wind gusts up to 40 MPH are possible. .Short Term [Tonight Through Sunday]... The surface low pressure system will be departing to our east tonight but rain chances will continue through Saturday as wrap around moisture associated with the upper low swings through the Tri-state region. Most of this rain should be light. Deep layer ridging will begin to build in on Sunday with warming temperatures and dry conditions. .Long Term [Sunday Night Through Friday]... By early next week the next weak trough and shortwave moves into Gulf region with weak zonal flow across local area. A surface low well to our NW brings a weak front to the Nrn Gulf before retreating back Nwd on Wed. This will bring a slight chance of rain and isold thunderstorms to the NRN counties Tues and Tues night followed by drying trend. Throughout the entire period, both high and low temps will shows a gradual warming trend. Inland highs Monday in the upper 70s to around 80 will rise to the mid 80s Wed and Thurs. Inland Lows Sun night in the low to mid 50s will rise by Thurs night to the low 60s. && .Aviation...
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[Through 12z Saturday] Rain, occasional thunderstorms, and low cigs (lower MVFR to IFR) are expected at all terminals today. The heaviest rain will end from south to north this evening, followed by IFR cigs and occasional DZ.
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&& .Marine... Winds and seas will continue to increase today with gale conditions developing over the western and offshore legs. For the nearshore waters of the Big Bend...advisory conditions will prevail at least through the passage of the low pressure system tonight. The gale conditions for the remainder of the coastal waters will also subside tonight with advisory conditions diminishing by Saturday evening. The strong onshore flow will result in heavy surf and high risk of rip currents along area beaches from Franklin County westward. A coastal flood watch is also in effect along Wakulla County eastward to the mouth of the Suwannee River. && .Fire Weather... With such wet conditions today, there will be no fire weather issues (i.e. Red flag conditions) through at least this weekend. && .Hydrology... We continue to be on track for a moderate to heavy rainfall event across much of the forecast area Friday and into Friday Night. Rainfall totals of 2 to 3 inches are expected to be fairly common, with higher amounts perhaps up to 5 to 6 inches will be possible. In general, the rivers most likely to flood and have higher impacts will be in the Florida Panhandle and Big Bend where flows are already somewhat elevated. Where the heaviest rain falls, there should also be other flooding on smaller streams and creeks, as well as areas of high water in low-lying areas and fields. A more detailed hydrology discussion is available on our ESF (Hydrologic Outlook) product, which can be found here: The most up-to-date river forecast information can always be found on our AHPS page (below). http:/ && .Preliminary Point Temps/PoPs... Tallahassee 69 53 67 51 76 / 100 60 30 10 0 Panama City 66 50 72 54 77 / 100 30 10 0 0 Dothan 63 48 70 51 76 / 100 50 20 0 0 Albany 63 50 65 50 75 / 100 80 40 10 0 Valdosta 69 55 65 51 75 / 100 80 40 10 0 Cross City 77 59 68 51 77 / 100 60 30 10 0 Apalachicola 70 56 71 53 73 / 100 30 10 0 0 && .TAE Watches/Warnings/Advisories... FL...Flood Watch through late tonight for Calhoun-Central Walton- Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf- Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden- Holmes-Inland Bay-Inland Dixie-Inland Franklin-Inland Gulf- Inland Jefferson-Inland Taylor-Inland Wakulla-Inland Walton- Jackson-Lafayette-Leon-Liberty-Madison-South Walton- Washington. COASTAL Flood Watch from 11 AM EDT this morning through this evening for Coastal Dixie-Coastal Jefferson-Coastal Taylor- Coastal Wakulla. High Rip Current Risk through this evening for Coastal Bay- Coastal Franklin-Coastal Gulf-South Walton. High Surf Advisory until 2 AM EDT /1 AM CDT/ Saturday for Coastal Bay-Coastal Franklin-Coastal Gulf-South Walton. GA...Flood Watch through late tonight for Baker-Ben Hill-Berrien- Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-Dougherty-Early- Grady-Irwin-Lanier-Lee-Lowndes-Miller-Mitchell-Quitman- Randolph-Seminole-Terrell-Thomas-Tift-Turner-Worth. AL...Flood Watch through late tonight for Coffee-Dale-Geneva-Henry- Houston. GM...Small Craft Advisory until 8 PM EDT this evening for Apalachee Bay-Coastal waters From Ochlockonee River to Apalachicola FL out to 20 NM-Coastal waters from Suwannee River to Keaton Beach FL out 20 NM. Gale Warning until 8 PM EDT this evening for Coastal waters from Apalachicola to Destin FL out 20 NM-Waters from Suwannee River to Apalachicola FL from 20 to 60 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM. && $$ NEAR TERM...FOURNIER SHORT TERM...BARRY LONG TERM...BLOCK AVIATION...FOURNIER MARINE...BARRY FIRE WEATHER...FOURNIER HYDROLOGY...LAMERS is the U.S. government's official web portal to all federal, state and local government web resources and services.