Severe Thunderstorm Warning 117, NWS Newport/Morehead City, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
410 PM EDT TUE AUG 11 2009

.SYNOPSIS...
THE HOT PATTERN OF THE LAST COUPLE DAYS WILL FINALLY BREAK AS A
TROUGH SLIDES OVER THE EASTERN U.S. TONIGHT. THE ASSOCIATED COLD
FRONT WILL SLIDE EAST ACROSS NC INTO WEDNESDAY MORNING...BEFORE
STALLING JUST WEST OF THE COASTAL PLAINS. THIS AREA WILL BECOME THE
FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS OVER THE NEXT COUPLE
DAYS AS WARM MOIST AIR CONTINUES TO FILTER INTO THE REGION. THE
UPPER LEVEL TROUGH WILL BEGIN TO BREAK DOWN FRIDAY...WITH A RIDGE
BUILDING BACK OVER THE WEST ATLANTIC.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 3 PM TUE...UPPER LVL TROUGH REMAINS W OF THE MOUNTAINS...AND
IS EXPECTED TO SLIDE E OVERNIGHT. THIS FEATURE WILL DEEPEN IN W
FLOW OVER THE REGION AND INCREASE SHEAR MARGINALLY INTO WED
MORNING. IN THE MEANTIME THE MID LVLS WILL BECOME MORE SATURATED
AND SHOULD SUPPORT ISO TSRA WELL AHEAD OF THE SFC FRONT LATE
TONIGHT...WITH SOME SCT ACTIVITY DEVELOPING TOWARDS DAYBREAK. THE
ADDED CLOUDS AND WAA SHOULD HOLD TEMPS IN THE MID TO UPPER 70S.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM TUE...THE THERMAL HEIGHTS WILL DROP IN RESPONSE TO THE
TROF...AND ADDED CLOUD COVER SHOULD KEEP DAYTIME HIGHS SEVERAL DEG
COOLER THAN TODAY WITH TEMPS STRUGGLING TO REACH 90. SOME BREAKS
IN THE CLOUDS ARE POSSIBLE...ESP NEARER THE COAST WHERE SEA BREEZE
FLOW COULD PUSH SOME OF THE STORM ACTIVITY INLAND. PREC WATER
VALUES WILL JUMP TO AROUND 2.25-2.5 BY WED AFTERNOON...AND THOUGH
SHEAR AND INSTABILITY MARGINAL...COULD HAVE SOME WET MICROBURST
RESULT IN DAMAGING WINDS. SPC HAS THE REGION IN A SLIGHT RISK FOR
WED...AND WITH FZ LVLS OVER 14K FT DONT SEE HAIL AS MUCH OF A
THREAT. ANOTHER HAZARD WILL BE THE POTENTIAL FOR LOCALIZED
FLOODING...ESP IF STORMS TRAIN OVER THE SAME AREAS. RAINFALL RATES
WILL BE SIGNIFICANT IN THIS TYPE OF AIRMASS WITH 1-2 POSSIBLE IN
AN HOUR. THOUGH CONVECTIVE...STILL EXPECT COVERAGE OF 50-60%
ACROSS MOST OF THE AREA GIVEN VERY MOIST AIRMASS. THE A SERIES OF
EMBEDDED AND MORE DIFFICULT TO TIME WEAK IMPULSES TRAVELING AROUND
THE BASE OF THE UPPER LVL TROF WILL TRIGGER ON AND OFF TSRA
ACTIVITY THROUGH LATE WEEK...WITH THE BEST CHANCE NEAREST THE
CONVERGENCE FRONTAL ZONE INLAND. HPC SHOWS 2-3 OF WIDESPREAD
RAINFALL LIKELY OVER THE NEXT 1-5 DAYS. PREC WATER VALUES DO NOT
APPRECIABLY DROP BELOW 2...SO WARM...HUMID...AND WET FCST ON TAP
FOR THE EAST.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 PM TUE...THE TROF BREAKS DOWN LATE WEEK AND THE DYNAMICS
WILL WEAKEN OVER THE AREA IN RESPONSE. A RIDGE OF HIGH PRES OVER
THE W ATLANTIC WILL BUILD INTO THE AREA. DESPITE MORE
SUBSIDENCE...THE CONTINUED WAA KEEPING PRES WATER OVER 2 WILL
KEEP AT LEAST A MINIMAL CHANCE FOR TSRA THROUGH THE WEEKEND AND
INTO NEXT WEEK.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
VFR EXPECTED TO PREVAIL THIS EVENING WITH LCL MVFR/IRF IN WDLY SCT
CONVECTIVE ACTIVITY. CONVECTIVE ACTIVITY BECOMING MORE WDSPRD
OVERNIGHT WITH CURRENT LINE OVER WRN NC MOVING E. FRONT WILL JUMP
INTO PIEDMONT TROF POSITION WED THEN REMAIN STALLED NEAR AREA
THU-SAT...LEADING TO SCT CONVECTIVE ACTIVITY DURING PERIOD WITH
ASSCTD MVFR/IFR. MUGGY CONDITIONS AND LIGHTER WINDS WILL LEAD TO
MORE THREAT EARLY MORNING FOG/STRATUS AS WELL.

&&

.MARINE...
USED NGM/GFS BLEND TONIGHT-FRI...THEN LEANED TO HPC/ECMWF FOR
SAT-SUN. EXPECT WINDS TO INCREASE SLIGHTLY THIS EVENING AS FRONT
DROPS INTO INLAND TROF POSTIONS. WENT WITH SCEC FOR CENTRAL WATERS
FOR 20KT/5 FT...AND MAINLY 15-20 KTS REST OF AREA TONIGHT AND
DIMINISHING TOWARD MORNING. FRONT THEN EXPECTED TO STALL INLAND
WED-SAT WITH PSBL SFC WVS MOVING ALONG IT RESULTING IN YO-YOING OF
WIND SPEEDS. LOW CONFIDENCE IN TIMING OF ANY WAVES SO MAINLY KEPT
WINDS SW 10-15 KTS WED-SAT. DID INDICATE WIND SHIFT WITH FRONTAL
PASSAGE SUN PER HPC/ECMWF BUT LOW CONFIDENCE IN THIS FEATURE.

USED PREVIOUS FCST AND WW3 FOR SEAS IN SHORT TERM...THEN KEPT IT
MAINLY 2-3 FT REST OF PERIOD AS WW3 LOOKS TOO HIGH SAT-SUN WITH
STRONGER GFS WINDS.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.

&&

SYNOPSIS...SJ
NEAR TERM...SJ
SHORT TERM...SJ
LONG TERM...SJ
AVIATION...JBM
MARINE...JBM

HAZARDOUS WEATHER OUTLOOK FOR EASTERN NORTH CAROLINA
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
305 AM EDT TUE AUG 11 2009

NCZ029-044>047-079>081-090>095-098-103-104-120900-
MARTIN-PITT-WASHINGTON-TYRRELL-MAINLAND DARE-GREENE-BEAUFORT-
MAINLAND HYDE-DUPLIN-LENOIR-JONES-CRAVEN-PAMLICO-CARTERET-ONSLOW-
OUTER BANKS DARE-OUTER BANKS HYDE-
305 AM EDT TUE AUG 11 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN NORTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

THE COMBINATION OF HOT TEMPERATURES AND HIGH HUMIDITY WILL RESULT
IN HEAT INDICES BETWEEN 100 AND 105 DEGREES MAINLY BETWEEN 11 AM
AND 5 PM ACROSS MOST OF THE AREA.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.