368 
FXUS61 KRNK 220111
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
811 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TONIGHT. LOW PRESSURE
DEVELOPING ACROSS THE GULF COAST STATES WILL IMPACT OUR WEATHER
SUNDAY WHILE HIGH PRESSURE WEDGES DOWN FROM THE NORTHEAST.

&&

.NEAR TERM /THROUGH SUNDAY/...
SURFACE HIGH PRESSURE OVER THE OHIO VALLEY WILL MOVE NORTHEAST
INTO NEW ENGLAND TONIGHT AND SUNDAY. LOW PRESSURE ALONG THE
LOUISIANA COAST WILL MOVE NORTHEAST TOWARD THE CAROLINA COAST BY
LATE SUNDAY. 

LIGHT AND VARIABLE SURFACE WINDS TONIGHT WILL GRADUALLY BECOME
EAST BY SUNDAY AFTERNOON AND CONTINUE TO VEER TO THE SOUTHEAST BY
LATE IN THE DAY. MODELS ARE SHOWING INCREASING MID AND HIGH LEVEL
MOISTURE WITH A DRY LAYER BETWEEN 600 AND 900 MB. NONE OF THE
GUIDANCE...INCLUDING THE HPC AND SPC SREF...THE LOCAL WRF OR
BUFKIT SHOW ANY PRECIPITATION IN THE FORECAST AREA UNTIL AFTER
18Z...AND THAT IS JUST FOR THE NORTHWEST NORTH CAROLINA MOUNTAINS.
BY 00Z MONDAY THE CHANCE OF RAIN WILL REACH THE REST OF NORTHERN
NORTH CAROLINA AND EXTREME SOUTHERN VIRGINIA. HAVE ADJUSTED THE
TIMING AND SLOWED DOWN THE ONSET OF RAINFALL TO ACCOUNT FOR THIS
GUIDANCE.

PLAYED LOWS TONIGHT CLOSE TO MOS...DROPPED A COUPLE DEGREES FROM
PREVIOUS FORECAST DUE TO SLOWER ARRIVAL OF CLOUDS. HIGH
TEMPERATURES ON SUNDAY WILL BE INFLUENCED BY THE DELAYED ONSET OF
PCPN AND THICKENING LOUD COVER. WENT WITH ADJMAVBC.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
THE TREND OF THE GUIDANCE TO SLOW THE PRECIPITATION ASSOCIATED WITH 
THE COASTAL LOW WILL CONTINUE INTO SUNDAY NIGHT. HAVE MADE 
ADJUSTMENTS TO THE POPS THAT REFLECT A SLOWER TIMING OF THE HIGHER 
POPS INTO THE AREA...HOWEVER HAVE MAINTAINED ROUGHLY THE SAME 
ORIENTATION OF THOSE POPS WITH THE HIGHEST PERCENTAGE ACROSS THE 
SOUTHEAST PART OF THE FORECAST AREA. HAVE CONTINUED THE TREND OF A 
SLOWER EXITING SYSTEM MONDAY INTO EARLY TUESDAY. AS SUCH...HAVE 
INCREASED POPS ON MONDAY INTO MONDAY NIGHT AS COMPARED TO EARLIER 
NUMBERS.

A STRONG...COOL...RAIN FED WEDGE WILL DEVELOP BY MONDAY...AND LAST 
THROUGH AT LEAST TUESDAY. AS SUCH...HAVE GONE WITH FORECAST HIGH 
TEMPERATURES BOTH MONDAY AND TUESDAY LOWER THAN GUIDANCE. BY LATE 
TUESDAY...BUT MORE ESPECIALLY TUESDAY NIGHT...WE WILL SEE A 
TRANSITION TO ISOLATED TO SCATTERED CONVECTIVE PRECIPITATION IN 
ADVANCE OF AN APPROACHING COLD FRONT. WILL HAVE ISOLATED SHOWERS IN 
THE WEST TUESDAY AFTERNOON...BUT INCREASING COVERAGE OF SHOWERS FROM 
WEST TO EAST ON TUESDAY NIGHT...BUT NOTHING HIGHER THAN CHANCE POPS 
AT THIS TIME.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ECMWF HAS A SURFACE AND UPPER LEVEL LOW OVER THE MIDWEST
APPROACHING THE REGION WEDNESDAY NIGHT INTO THURSDAY MORNING. THE
LOW PUSHES NORTHEAST OVER THE GREAT LAKES WITH MOST OF THE ENERGY
FOLLOWING AND SLIDING NORTH OF THE FORECAST AREA. HAVE CHANCE POPS
IN THE NORTHERN AND CENTRAL PORTIONS OF THE COUNTY WARNING AREA
AND TAPERING OFF FROM THE SOUTHEAST TO NORTHWEST THROUGH FRIDAY.
AGAIN WITH TEMPERATURES AND 1000-850MB...850-700MB THICKNESSES
LOWERING TO NEAR FREEZING...SOME LIGHT SNOW CAN BE MIXED IN WITH
THE RAIN ESPECIALLY IN THE HIGHER ELEVATIONS WEST OF THE BLUE
RIDGE THURSDAY NIGHT. 

MAX TEMPERATURES WILL START COOLING DOWN INTO THE LOW TO MID 40S
IN THE WEST TO LOW 50S IN THE PIEDMONT AREAS OF VA/NC.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH SUNDAY WITH
INCREASING MID AND HIGH CLOUDS. EXPECT VFR CONDITIONS THROUGH THE
PERIOD WITH THE EXCEPTION OF RIVER VALLEY FOG IN WEST VIRGINIA. SO HAVE
MAINTAINED MVFR FOG IN LWB DURING THE EARLY MORNING. 

LOW PRESSURE WILL SLIDE NORTHEAST FROM THE GULF COAST STATES TO
THE SOUTHEAST COAST BY MONDAY NIGHT. CEILINGS WILL CONTINUE TO
LOWER SUNDAY THROUGH MONDAY. RAINFALL IS EXPECTED AT THE TAF SITES
LATE SUNDAY. MODELS WERE STILL SLOWING DOWN THE ARRIVAL TIME
OF THE RAIN...SO WITH THAT IN MIND WE MAY NOT SEE SUB VFR
CONDITIONS UNTIL AFTER 00Z MONDAY.

TUESDAY WILL FEATURE IMPROVING CONDITIONS AS THE AFC LOW TRACKS
NORTHEAST UP THE EASTERN SEABOARD...WITH HIGH PRESSURE BUILDING
OVER THE MID ATLANTIC FOR THE MIDDLE OF THE WEEK.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...AMS
SHORT TERM...DS
LONG TERM...REB
AVIATION...AMS/KK