FXUS61 KLWX 120210
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
910 PM EST FRI DEC 11 2009
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE MID ATLANTIC
OVERNIGHT...AND MOVE OFFSHORE ON SATURDAY. LOW PRESSURE WILL
IMPACT THE REGION LATE SATURDAY INTO SUNDAY NIGHT...BRINGING RAIN
AND POSSIBLY A WINTRY MIX TO THE REGION. HIGH PRESSURE BUILDS IN
BRIEFLY FOR MONDAY...WITH ANOTHER COLD FRONT EXPECTED TUESDAY.
HIGH PRESSURE BUILDS ACROSS THE MID ATLANTIC FOR THE REMAINDER OF
THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
HIPRES CURRENTLY CENTERED OVER THE VA/NC APPALACHIANS TO CONTINUE
PUSHING EAST OVER THE AREA REST OF TNGT. CLR SKIES AND LGT WINDS
ALLOWING GOOD RADIATIONAL COOLING CONDITIONS AS HIPRES SETTLES
OVRHD. TEMPS AT INTERIOR LOCALES SHOULD DROP TO NEAR LAST NIGHT/S
READINGS...CALM WINDS WILL ALLOW FOR MORE URBAN AND OPEN WATER
EFFECTS TO CREATE HEAT ISLANDS. LOWS WILL RANGE FROM AROUND 10F
FOR SHELTERED LOCATIONS IN THE POTOMAC HIGHLANDS TO LOWER 20S AT
INTERIOR LOCALES...MID 20S IN THE URBAN AND COASTAL LOCATIONS.
WINDS ARE CURRENTLY 15 TO 20 MPH ACROSS THE MOUNTAINS OUT
WEST...THOUGH THEY WILL EASE AS THE HIGH MOVES FURTHER EAST...WIND
CHILLS OUT WEST MAY BE SUBZERO IN SOME LOCALES...THOUGH NOT LOW
ENOUGH FOR AN ADVISORY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
SFC HIPRES/H8 RIDGE AXIS BEGINS TO PUSH OFF THE MID ATLANTIC COAST
SAT...PLACING THE REGION IN SLY RETURN FLOW DURING THE AFTN. ENSUING
WAA PATTERN WILL MODERATE THE AIRMASS WITH DAYTIME HIGHS IN THE
L40S...EXCEPT MU30S ACROSS THE HIGH ELEVATIONS. A SUNNY START TO THE
DAY WILL GIVE WAY INCREASING HI CLDS AS THE ULVL JET MAX PUSHES NWD
OVER THE REGION.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
COASTAL LOW PRESSURE WILL IMPACT THE MID ATLANTIC REGION LATE
SATURDAY INTO SUNDAY. RUN TO RUN MODEL CONSISTENCY HAS SHOWN THE
TENDENCY TO PUSH THE LOW CENTER A LITTLE FURTHER INLAND. BOTH THE
GFS AND NAM CONTINUE TO BRING PRECIP TO THE CWFA LATE SATURDAY
NIGHT...MAINLY AFTER 06Z. A WINTRY MIX OF SNOW...SLEET...RAIN AND
FREEZING RAIN WILL BE POSSIBLE ESPECIALLY WEST OF THE BLUE RIDGE
MOUNTAINS. THERE COULD ALSO BE A BRIEF PERIOD OF THE WINTRY MIX
ACROSS THE FOOTHILLS OF VA...AND THE NORTHERN/WESTERN SUBURBS OF DC
AND BALTIMORE BEFORE PRECIPITATION TURNS TO ALL RAIN. OVERALL...ANY
ACCUMULATIONS OF ICE ARE EXPECTED TO BE LIGHT... WITH WEST OF THE
BLUE RIDGE MOUNTAINS HAVING THE BEST CHANCES OF ANY ACCUMULATIONS.
HIGH PRESSURE WILL BUILD IN BRIEFLY FOR MONDAY...WITH THE NEXT COLD
FRONT EXPECTED FOR TUESDAY. HIGH PRESSURE WILL BUILD BACK OVER THE
AREA FOR THE REMAINDER OF THE WEEK.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
WEST WINDS HAVE WEAKENED TO LESS THAN 10 KT ACROSS THE
TERMINALS...AND WILL BE LIGHT/CALM BETWEEN 03Z- 12Z. VFR
CONDITIONS EXPECTED THRU SAT AFTN UNDER HIGH PRESSURE...SKC EXPECTED THRU
SAT MRNG WITH HI CLDS INCREASING DURING THE AFTN.
SUB VFR CIGS/VSBYS ARE LIKELY FOR SATURDAY NIGHT/SUNDAY AS LOW
PRESSURE IMPACTS THE REGION. A WINTRY MIX IS POSSIBLE AT KMRB...WITH
SOME FREEZING RAIN/SLEET/SNOW. FOR THE REMAINDER OF THE TERMINAL
SITES...THE WINTRY 4 25 47 NE6 30.36S
MARY ESTHER NOT AVBL
MILTON CLOUDY 45 26 47 NE7 30.36R
WHTNG S FIELD CLOUDY 46 23 40 NE9 30.36R
PENSACOLA CLOUDY 44 25 47 NE7 30.35R
NAS PENSACOLA CLOUDY 47 26 44 NE9 30.34S
VALPARAISO MOCLDY 44 25 46 NE9 30.36F
$$
...MARINE OBSERVATIONS...
STATION/POSITION TIME TEMP WIND PRES WAVE
AIR SEA DIR/SP/G HT/PER
(UTC) (F) (DEG/KT/KT) (MB) (FT/S)
PASCAGOULA 0200 46 70/ 8/ 11 1026.3F
PETIT BOIS ISL 0200 47 60/ 17/ 21 1026.5F
E DAUPHIN ISLAND 0100 46 60/ 14/ 16 1027.5R
MIDDLE BAY LIGHT 0100 45 50/ 12 N/A
USCG MOBILE BAY 0200 44 56 40/ 10/ 13 1028.3R
STATE DOCKS 0200 54 N/A
MEAHER PARK 0100 43 30/ 4 1028.1R
12 S ORANGE BCH 0200 52 64 60/ 19/ 23 1026.6S 5/ 6
PENSACOLA BAY 0200 45 55 VRB 6/ 10 1028.8F
67 S FORT MORGAN 0200 61 74 1024.7F
115 SE PENSACOLA 0055 62 73 70/ 21/ 27 1025.3 8/ 7
MID GULF/42001 0200 76 78 100/ 21/ 23 1018.3R 8/ 8
EAST GULF/42003 0200 72 76 60/ 19/ 23 1021.0R 7/ 7
$$
...NEARBY LOCATIONS...
CITY SKY/WX TMP DP RH WIND PRES REMARKS
GULFPORT CLOUDY 47 30 51 NE8 30.31S
BILOXI CLOUDY 45 25 45 NE10 30.32S
PASCAGOULA CLOUDY 45 26 47 NE7 30.33F
HATTIESBURG CLOUDY 40 26 57 E6 30.35F
LAUREL CLOUDY 39 21 48 MISG 30.32F
MERIDIAN CLOUDY 39 19 44 NE7 30.37S
MERIDIAN NAS CLOUDY 39 19 44 E5 30.39R
MONTGOMERY CLOUDY 40 19 43 NE5 30.43R
MAXWELL AFB CLOUDY 41 18 38 E8 30.43R
TROY MOCLDY 40 23 50 E5 30.41R
FORT RUCKER MOCLDY 41 23 48 E3 30.39S
DALEVILLE CLOUDY 42 23 47 NE8 30.40R
DOTHAN MOCLDY 41 25 53 E7 30.43S
$$
...OTHER SURROUNDING LOCATIONS...
CITY SKY/WX TMP DP RH WIND PRES REMARKS
BIRMINGHAM CLOUDY 37 12 35 E3 30.43R
TUSCALOOSA CLOUDY 40 22 48 NE3 30.43R
COLUMBUS GA CLOUDY 39 16 39 E8 30.42F
PANAMA CITY MOCLDY 44 26 49 MISG 30.35F
TALLAHASSEE CLOUDY 44 29 55 NE9 30.40R
BATON ROUGE LGT RAIN 43 33 68 E12 30.28R
NEW ORLEANS LGT RAIN 46 38 73 NE9 30.30R
SLIDELL LGT RAIN 45 31 58 E6 30.31R
JACKSON CLOUDY 41 21 44 N8 30.35F
MCCOMB CLOUDY 40 23 50 E5 30.33R
$$
...SURROUNDING MARINE OBSERVATIONS...
STATION/POSITION TIME TEMP WIND PRES WAVE
AIR SEA DIR/SP/G HT/PER
(UTC) (F) (DEG/KT/KT) (MB) (FT/S)
GULFPORT 0200 48 80/ 18/ 22 1026.4R
WAVELAND 0200 46 66 60/ 14/ 16 1025.4F
GULFPORT W PIER 0200 46 70/ 16/ 19 1026.0F
PASCAGOULA RGN A 0200 46 70/ 13/ 15 1026.7F
SHIP ISLAND 0200 48 80/ 18/ 22 1026.4R
PASCAGOULA PORT 0200 65 N/A
GRAND ISLE 0200 55 60 60/ 17/ 22 1024.1R
SOUTHWEST PASS 0100 60 70/ 28/ 29 1022.4F
PILOT STATION E 0200 64 55 90/ 26/ 34 1023.6R
SHELL BEACH 0200 51 53 70/ 20/ 24 1024.1F
BAYOU LABRANCH 0200 46 51 100/ 8/ 12 1026.4F
W LAKE PONCHRTRN 0100 46 70/ 16/ 19 N/A
PANAMA CITY 0200 42 61 60/ 10/ 15 1027.6R
APALACHICOLA 0200 44 VRB 15/ 19 1027.9F
TYNDALL TOWER C 0200 51 65 70/ 26/ 30 1026.3R
S APLCHCLA/42036 0200 72 76 60/ 19/ 23 1021.0R 7/ 7
$$