Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 48 49 50
000
FXUS62 KTBW 260741
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
341 AM EDT WED AUG 26 2015

.SYNOPSIS...IN THE MID/UPPER LEVELS...AN AMPLIFIED MERIDIONAL FLOW
CONTINUES THROUGHOUT THE CONUS WITH HIGH PRESSURE RIDGING FROM NEW
MEXICO NORTHWARD THROUGH EASTERN MONTANA. A CLOSED UPPER LOW ON THE
ONTARIO/QUEBEC BORDER MOVES SLOWLY NORTHWARD. LONG WAVE TROUGHING
EXTENDS FROM THIS LOW THROUGH THE OHIO RIVER VALLEY SOUTHWARD TO
NORTHERN FLORIDA. THE SUBTROPICAL RIDGE EXTENDS WEST OVER THE
BAHAMAS AND SOUTHERN FLORIDA. THE TROUGH DEEPENS FURTHER ON THURSDAY
AND CAUSES THE SUBTROPICAL RIDGE TO WEAKEN AND SHIFT TO THE EAST. ON
THE SURFACE...A STATIONARY FRONTAL BOUNDARY EXTENDS ALONG THE
EASTERN SEABOARD...OVER NORTHERN FLORIDA AND INTO THE GULF OF
MEXICO. AS THE TROUGH DEEPENS ON THURSDAY...IT WILL CAUSE THE
FRONTAL BOUNDARY TO SHIFT FARTHER SOUTH OVER CENTRAL FLORIDA.

.SHORT TERM (TODAY-THURSDAY)...WEST SOUTHWEST ONSHORE FLOW WILL
CONTINUE THROUGH THURSDAY WITH SHOWERS AND STORMS FORMING OVER THE
COASTAL WATERS AND MOVING INLAND. THE HIGHEST RAIN CHANCES WILL
OCCUR SOUTH OF TAMPA BAY WITH SEA BREEZE COLLISIONS BETWEEN THE WEST
COAST SEA BREEZE AND EAST COAST SEA BREEZE OVER THE INLAND COUNTIES.
AS THE STATIONARY FRONT SHIFTS SOUTH ON THURSDAY...THIS WILL CREATE
HIGHER RAIN CHANCES WITH WIDESPREAD SHOWERS AND STORMS THROUGHOUT
THE AFTERNOON. TEMPERATURES WILL REMAIN ON THE WARM SIDE ON
WEDNESDAY COMING IN A FEW DEGREES ABOVE AVERAGE. AS THE BOUNDARY
SHIFTS SOUTH OVER CENTRAL FLORIDA ON THURSDAY...THE TEMPS WILL COOL
DOWN TO A MORE SEASONAL NORM.

TROPICAL STORM ERIKA CURRENTLY LOCATED APPROXIMATELY 750 MILES EAST
SOUTHEAST OF PUERTO RICO IS TRACKING WEST NORTHWEST TOWARD THE
LESSER ANTILLES ISLANDS AROUND 18 KNOTS. MODELS HAVE THE STORM
CONTINUING TO TRACK WEST NORTHWEST TOWARD THE BAHAMAS OVER THE NEXT
5 DAYS. NO DIRECT IMPACTS ARE EXPECTED AT THE CURRENT TIME FOR
CENTRAL AND SOUTHWEST FLORIDA BUT WE WILL CONTINUE TO CLOSELY
MONITOR THIS STORM THROUGHOUT THE WEEK.

&&

.MID/LONG TERM (THURSDAY NIGHT-TUESDAY)...
A MID LEVEL TROUGH OVER THE EASTERN U.S. SOUTHWARD INTO THE GULF OF
MEXICO EARLY IN THE PERIOD WILL BECOME POSITIVELY TILTED AND SHIFT
WESTWARD OVER THE WEEKEND INTO EARLY NEXT WEEK AS A RIDGE BUILDS IN
FROM THE EAST. MEANWHILE AT THE SURFACE THE STALLED BOUNDARY OVER
THE REGION THURSDAY NIGHT AND FRIDAY WILL WASH OUT OVER THE WEEKEND
WITH HIGH PRESSURE BUILDING IN FROM THE EAST HELPING TO LIFT THE
SUBTROPICAL RIDGE TO THE NORTH. THE BIG QUESTION IS WHERE AND HOW
STRONG ERIKA WILL BE DURING THIS TIME. THE LATEST GFS IS KEEPING
ERIKA WEAK AND MORE OF A WAVE AS IT MOVES ACROSS/NEAR SOUTH FLORIDA
SUNDAY AND INTO THE EASTERN GULF OF MEXICO EARLY NEXT WEEK WHILE THE
CANADIAN AND NOW ALSO THE ECMWF KEEP IT STRONGER. AT THE PRESENT
TIME THE NHC FORECAST IS STILL BRINGING ERIKA THROUGH THE BAHAMAS
AND TOWARD THE FLORIDA SOUTHEAST COAST SUNDAY NIGHT INTO MONDAY SO
STAY TUNED AS THE FORECAST COULD CHANGE OVER THE NEXT FEW DAYS.

FOR THURSDAY NIGHT THROUGH SATURDAY WE WILL SEE A GRADUAL TRANSITION
BACK TO A MORE EAST TO SOUTHEAST FLOW AS THE TROUGH WEAKENS AND THE
HIGH PRESSURE BEGINS TO BUILD IN FROM THE EAST. WE WILL HAVE PLENTY
OF MOISTURE AROUND WITH A SHOWER OR STORM POSSIBLE AT ALMOST
ANYTIME...BUT BEST CHANCES ON LAND SHOULD BE DURING THE AFTERNOON
AND EVENING HOURS WITH THE SEA BREEZE CIRCULATIONS.

FORECAST FOR SUNDAY THROUGH TUESDAY IS HIGHLY DEPENDENT ON THE TRACK
AND STRENGTH OF ERIKA. AT THE PRESENT TIME HAVE FOLLOWED A CONSENSUS
OF THE MODELS AND LEFT LIKELY POPS IN THE FORECAST EACH DAY.
HOWEVER...IF ERIKA IS ON THE STRONGER SIDE OF THE FORECAST THEN
SUNDAY COULD BE A RATHER DRY DAY AS WE WOULD BE IN THE SUBSIDENCE
ZONE OUT AHEAD OF THE SYSTEM. WE WILL HAVE TO WAIT AND SEE HOW
THINGS EVOLVE OVER THE NEXT FEW DAYS.

DAYTIME HIGH TEMPERATURES SHOULD BE NEAR NORMAL DURING FRIDAY AND
SATURDAY WITH READINGS CLIMBING INTO THE UPPER 80S TO LOWER 90S.
THEN WITH THE EXPECTED INCREASE IN CLOUDS AND MOISTURE SUNDAY
THROUGH TUESDAY HIGHS SHOULD BE NEAR TO A COUPLE OF DEGREES BELOW
NORMAL IN THE MID 80S TO AROUND 90. OVERNIGHT LOWS WILL REMAIN NEAR
NORMAL IN THE MID 70S INLAND TO NEAR 80 ALONG THE COAST THROUGH THE
PERIOD.

&&

.AVIATION...OVERALL VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED SO WILL
KEEP VCTS AT ALL TERMINALS DURING THE AFTERNOON. BRIEF MVFR/IFR
CEILING AND VISIBILITY CONDITIONS ARE POSSIBLE IN THE VICINITY OF
HEAVIER RAINS AND THUNDERSTORMS.

&&

.MARINE...INTERACTION BETWEEN A TROUGH OF LOW PRESSURE TO THE NORTH
AND SUBTROPICAL HIGH PRESSURE OVER SOUTHERN FLORIDA WILL KEEP WEST
SOUTHWEST WINDS ACROSS THE GULF COAST WATERS THROUGH FRIDAY. WINDS
WILL SHIFT TO THE EAST SOUTHEAST OVER THE WEEKEND AS HIGH PRESSURE
SHIFTS SLIGHTLY NORTHWARD. WINDS WILL REMAIN BELOW 10 KNOTS AND SEAS
2 FEET OR LESS EXCEPT IN THE VICINITY OF THUNDERSTORMS WHERE LOCALLY
HEAVY RAIN...GUSTY WINDS...LOCALLY HIGHER SEAS...AND FREQUENT CLOUD
TO WATER LIGHTNING WILL OCCUR.

&&

.FIRE WEATHER...NO FIRE WEATHER ISSUES ARE ANTICIPATED AS A MOIST
TROPICAL AIR MASS REMAINS OVER THE FLORIDA PENINSULA.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  92  77  89  76 /  30  20  60  30
FMY  91  75  89  75 /  50  20  80  30
GIF  93  75  90  74 /  50  30  70  30
SRQ  91  77  89  75 /  30  30  60  40
BKV  93  73  90  72 /  30  20  60  30
SPG  91  79  89  77 /  20  20  60  30

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&

$$

SHORT TERM/AVIATION/MARINE/FIRE WEATHER...74/WYNN
MID/LONG TERM/DECISION SUPPORT...69/CLOSE



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