Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

000
FXUS62 KTBW 221851
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
251 PM EDT WED OCT 22 2014

.SYNOPSIS...
ALOFT - A TROUGH REACHED FROM THE CENTRAL CANADIAN PRAIRIES TO THE
SOUTHERN HIGH PLAINS...A RIDGE EXTENDED FROM THE WESTERN GULF
COAST TO ONTARIO...AND A LOW WAS ON THE VA/NC COAST. SURFACE -
HIGH PRESSURE ALONG THE ONTARIO/QUEBEC BORDER SPRAWLED DOWN TO THE
GULF COAST...THE SURFACE REFLECTION OF THE VA/NC UPPER LOW TRAILED
A FRONTAL BOUNDARY THAT ARCED SOUTHWARD THEN WESTWARD ACROSS
SOUTHERN FL...AND TROPICAL DEPRESSION NINE WAS IN THE BAY OF
CAMPECHE.

&&

.SHORT TERM (TONIGHT AND THURSDAY)...
THE UPPER LOW AND TROUGHING SLIP OFF THE EASTERN SEABOARD AS THE
WESTERN UPPER RIDGE SHIFTS EASTS...FROM THE GREAT LAKES TO THE
CENTRAL GULF COAST...AND FLATTENS SOME AS A SHORT WAVE TROUGH
DROPS ACROSS THE UPPER GREAT LAKES FROM CENTRAL CANADA. THE HIGH
PRESSURE ON THE GULF COAST SETTLES IN ALONG THE GULF COAST TO THE
SOUTHEAST U.S. WITH THE FRONT MORPHING INTO A TROUGH AND SAGGING
IN JUST SOUTH OF THE KEYS. TROPICAL DEPRESSION NINE EXITS THE BAY
OF CAMPECHE FOR THE EAST COAST OF THE YUCATAN.

DEEPER MOISTURE ALONG THE FRONT/TROUGH WILL EXIT THE AREA TODAY
DRIER AND SLIGHTLY AIR WORKS IN FROM THE NORTHWEST AND NORTH...
THE CURRENT FORECASTS WILL KEEP SOME LOW END SHOWERS AND STORMS
ACROSS THE FAR SOUTHERN AND SOUTHEASTERN COUNTIES THIS AFTERNOON
THEN END PRECIPITATION IN THE EARLY EVENING...WITH RAIN FREE
CONDITIONS FOR ALL LOCATIONS THROUGH THU.

ENOUGH DRY AIR WORKS TO PRECLUDE ANY LATE NIGHT FOG. OTHERWISE
MOSTLY CLEAR/SUNNY ACROSS THE NORTH WHILE SOUTHERN COUNTIES WILL
BE PARTLY CLOUDY/SUNNY. LOWS TONIGHT WILL BE COOL IN THE
NORTH...UPPER 40 TO AROUND 50...WHILE CENTRAL AND SOUTHERN AREAS
WILL BE JUST UNDER OR AROUND NORMAL. HIGHS THU JUST UNDER NORMAL.

.LONG TERM (THURSDAY NIGHT-WEDNESDAY)...
A VIGOROUS S/WV WILL MOVE SE OUT OF GA AND ACROSS FL FRI NIGHT.
MODELS SHOW SIGNIFICANT H7-H3 Q-VECTOR CONVERGENCE WHICH INDICATES
LARGE SCALE LIFT FRI AND FRI NIGHT W/ THIS SYSTEM. THAT
SAID...AVAILABLE MOISTURE WILL STRONGLY LIMIT PRECIP POTENTIAL AS
DEEPEST MOISTURE REMAINS CONFINED ACROSS S FL ALONG AND SOUTH OF A
STATIONARY FRONTAL BOUNDARY FORECAST TO BE NEAR OR JUST SOUTH OF
LAKE OKEECHOBEE PER GFS AND ECMWF. SHOULD NOTE THE NAM IS MUCH
MORE AGGRESSIVE DRAWING THIS BOUNDARY AND ASSOC MOISTURE NORTH
AHEAD OF THE UPR S/WV ON FRI...BUT THIS IS DUE TO A MUCH FURTHER
NORTH FORECAST POSITION OF TD9 IN THE NAM WHICH HELPS PUSH
MOISTURE NORTH INTO CEN FL DUE TO LOW LEVEL ESE FLOW AROUND THE
LOW LEVEL CENTER. AM COMPLETELY DISREGARDING THIS SOLN GIVEN
EXPECTED TRACK OF THE SYSTEM MUCH FURTHER SOUTH PER ECMWF...GFS
AND NHC OFFICIAL TRACK FORECAST. GIVEN THIS...APPEARS ONLY FAR SRN
COUNTIES WILL HAVE ENOUGH MOISTURE TO PROVIDE SIG PRECIP
POTENTIAL ASSOC W/ THE S/WV WILL SHOW 20-35 POPS WHICH IS MOST
CLOSELY FOLLOWING MAV GUIDANCE. DEEP S FL COULD GET SIGNIFICANT
RAINFALL GIVEN DEEP TROPICAL AIRMASS OVER THAT REGION...BUT THE
HIGHEST QPF IS EXPECTED TO REMAIN JUST SOUTH OF FMY AREA.
REINFORCING HIGH PRESSURE WILL SHOVE THE FRONT AND AFOREMENTIONED
MOISTURE POOL WELL SE OF THE REGION BY SAT WITH COOLER AND DRIER
AIR FILTERING INTO THE AREA. THIS WILL PROVIDE SOME CRISP...COOL
MORNING LOWS SLIGHTLY BELOW NORMAL OVER THE WEEKEND WITH HIGHS
GENERALLY NEAR NORMAL VALUES WHICH IS IN THE LOW TO MID 80S.
EXPECT A WARMING AND MOISTENING TREND EARLY NEXT WEEK AS MID TO UP
LEVEL RIDGE MOVES ACROSS THE AREA AND ESE FLOW RETURNS AS SFC HIGH
MOVES OFF THE MID ATL COAST.

VERY UNCLEAR WRT WHAT HAPPENS TO TD9 NEXT WEEK. THE GFS SPLITS
ENERGY ASSOC W/ TD9 IN TWO PIECES ON EITHER SIDE OF CUBA. ONE
PIECE RACES OFF TO THE ENE AHEAD OF THE AFOREMENTIONED S/WV WITH
THE OTHER REMAINING IN THE WRN CARIBBEAN. GFS THEN STRENGTHENS
THE PIECE LEFT BEHIND AND MOVES IT NORTH INTO THE ERN GOMEX AS A
STRONG TS. COULD HAPPEN...BUT WAY TO COMPLICATED AND NOT NEAR
ENOUGH SUPPORT BY OTHER MODELS TO PUT MUCH STOCK IN THAT SOLN OUT
7 DAYS. THAT SAID...SHOULD NOTE THE ECMWF DOES SHOWS A WEAK LOW
PRESSURE FEATURE BETWEEN YUCATAN AND CUBA AS WELL...SO WILL BE
INTERESTING TO SEE WHAT BECOMES OF TD9 NEXT WEEK. FOR NOW FOLLOWED
ECMWF FOR LAST FEW PERIODS OF THE FORECAST WHICH IS MUCH LESS
AGGRESSIVE THAN THE GFS.

&&

.AVIATION...
22/18Z-23/18Z. PREVAILING VFR AT NORTHERN TERMINALS...FEW-SCT MID
AND HIGH CLOUDS WITH NORTHEAST WINDS. FOR PGD/FMY/RSW...BKN VFR
CIGS WITH VCNTY SHRA AND TSRA ENDING AT 02Z FOR PGD AND 05Z FOR
BOTH FMY AND RSW. EXPECT OCNL LATE MVFR CIGS. LIGHT EASTERLY WINDS
INCREASE SLIGHTLY FROM THE NE THU MORNING.

&&

.MARINE...
HIGH PRESSURE WILL BUILD NORTH OF THE REGION THROUGH THE WEEKEND AS
AN AREA OF LOW PRESSURE RESIDES SOUTH OF FLORIDA. THIS WILL INCREASE
THE PRESSURE GRADIENT AND WINDS ACROSS THE AREA. EXPECT ADVISORY
LEVEL WINDS ON GULF WATERS STARTING TONIGHT AND CONTINUING THROUGH
THURSDAY MORNING. ELEVATED EAST-NORTHEAST FLOW WILL THEN CONTINUE
ACROSS THE WATERS THROUGH THE WEEKEND...WITH WINDS PERIODICALLY
REACHING EXERCISE CAUTION OR ADVISORY LEVELS.

&&

.FIRE WEATHER...
HIGH PRESSURE SETTLES IN ACROSS THE GULF COAST AND SOUTHEASTERN
STATES THROUGH THE PERIOD...DOMINATING MUCH OF THE NORTH HALF OF THE
AREA WITH GENERALLY DRY CONDITIONS. A FRONT OVER SOUTHERN FLORIDA
THIS AFTERNOON SLIPS SOUTH TONIGHT THEN RESIDES AS A TROUGH OF LOW
PRESSURE BETWEEN THE KEYS AND CUBA. THE SOUTHERN AREA WILL BE DRY
THURSDAY BUT THEN MOISTURE DRIFTING NORTHWARD WILL BRING SOME
SHOWERS AND THUNDERSTORMS INTO THE WEEKEND.

DRY AIR WORKING IN FROM THE NORTH WILL BRING RH LEVELS APPROACHING
35 PERCENT ACROSS MUCH OF THE NATURE COAST THURSDAY. ONE EXCEPTION
WILL BE LEVY COUNTY WHERE THE RH WILL DROP BELOW 35 PERCENT FOR
AROUND 4 HOURS. HOWEVER ERC VALUES DO NOT SUPPORT A RED FLAG
WARNING.

FOG POTENTIAL TONIGHT...FOG IS NOT EXPECTED.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  64  84  63  82 /   0   0   0  10
FMY  68  86  70  83 /  30   0  20  40
GIF  63  82  61  83 /   0   0  10  10
SRQ  65  86  65  82 /   0   0  10  10
BKV  52  83  53  82 /   0   0  10  10
SPG  69  82  68  80 /   0   0  10  10

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 10 AM EDT
     THURSDAY FOR ENGLEWOOD TO TARPON SPRINGS OUT 20 NM-
     ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON
     SPRINGS TO SUWANNEE RIVER OUT 20 NM-TARPON SPRINGS TO
     SUWANNEE RIVER OUT 20 TO 60 NM.

     SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EDT
     THURSDAY FOR BONITA BEACH TO ENGLEWOOD OUT 20 NM-
     BONITA BEACH TO ENGLEWOOD OUT 20 TO 60 NM.

&&

$$

SHORT TERM/AVIATION/FIRE WEATHER...09/RUDE
LONG TERM...88/GITTINGER
MARINE...007/DOUGHERTY
DECISION SUPPORT...24/HUBBARD








USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.