FXUS61 KRLX 231854
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
155 PM EST WED DEC 23 2009
.SYNOPSIS...
HIGH PRESSURE TONIGHT...SHIFTS EAST AS TEMPERATURES TURN WARMER
THURSDAY. RAINY AND BREEZY OCCLUDED FRONT EXPECTED THURSDAY NIGHT
THROUGH CHRISTMAS. TURNING COLDER AGAIN THIS WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
HIGH PRESSURE RIDGE TO OUR NW WILL BREAK DOWN DURING THE OVERNIGHT
AND INTO THURSDAY. STORM SYSTEM OVER THE LOWER MISSISSIPPI VALLEY
WILL MOVE NORTHWARD DURING THE DAY TOMORROW. MODELS CONTINUE TO
SLOW SYSTEM DOWN A TAD AS LOW WINDS UP. WAA ON SOUTHERLY FLOW WILL
WARM TEMPERATURES TOMORROW INTO THE 30S AND 40S WITH CLOUDS
INCREASING AS WELL. OCCLUDED FRONT APPROACHES LATE IN THE DAY
TOMORROW AND INTRODUCED SLGT CHC POPS OVER EXTREME SOUTHERN ZONES.
WENT WITH A BLEND OF GEM/GMOS/MET GUIDANCE FOR LOWS AND HIGHS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
NOT MUCH CHANGE FROM PREVIOUS MODEL RUNS. STRONG LOW PRESSURE WILL
LIFT WELL NORTH AND WEST OF OUR AREA CHRISTMAS EVE AND CHRISTMAS
DAY. WARM FRONT WILL LIFT NORTH CHRISTMAS EVE NIGHT...FOLLOWED BY A
COLD FRONT CHRISTMAS DAY. STRONG SURFACE HIGH PRESSURE RIDGING
SOUTHWARD EAST OF THE MOUNTAINS WILL BE SLOW TO GET DISLODGED BY THE
APPROACHING SYSTEM. THE ONE CHANGE IS THAT MODELS PUT US IN A
RELATIVE DRY SLOT FRIDAY NIGHT INTO SATURDAY BEHIND THE COLD
FRONT...BEFORE WRAPAROUND MOISTURE AND COLD ADVECTION COME BACK IN
FORCE DURING SATURDAY.
EXPECT MAIN PRECIP BAND TO DEVELOP ACROSS THE AREA THURSDAY
NIGHT...AND LIFT OUT WITH THE WARM FRONT FRIDAY MORNING. AROUND A
HALF INCH OF RAINFALL IS EXPECTED MOST AREAS...WHICH SHOULD NOT BE
ENOUGH TO CAUSE SIGNIFICANT FLOODING WITH THE MELTING SNOW PACK.
HOWEVER...IF MORE RAINFALL OCCURS...THEN THIS WOULD BECOME MORE OF A
PROBLEM. FOR NOW...NO MENTION OF FLOODING ISSUES.
WITH THAT STRONG HIGH ONLY SLOWLY GIVING WAY...STILL LOOKS LIKE AN
ICING EVENT SETTING UP FOR MAINLY EAST FACING SLOPES OF THE NORTHERN
AND CENTRAL MOUNTAINS THURSDAY NIGHT INTO FRIDAY MORNING...BEFORE
WARM AIR FINALLY ERODES THE COLD AIR DAMMED UP AGAINST THE
MOUNTAINS. THIS MAY LEAD TO AN ADVISORY OR WARNING...BUT STILL LOTS
OF TIME FOR DAY SHIFT TO EVALUATE FURTHER. IN ANY EVENT...THE WARM
AIR WILL WIN OUT LATER FRIDAY MORNING. TEMPERATURES WILL REALLY
REBOUND AHEAD OF THE COLD FRONT FRIDAY...WITH GUSTY SOUTH WINDS.
WINDS MAY ALSO BE AN ISSUE IN THE MOUNTAINS FRIDAY WITH A 60 TO 70
KT 850 MB SOUTHERLY JET FORECAST. AGAIN...WILL LET DAY SHIFT FURTHER
EVALUATE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODELS APPEAR TO BE IN BETTER AGREEMENT WITH THE OVERALL PATTERN.
WEATHER CONTINUES TO REMAIN UNSETTLED FOR THE FIRST PART OF THE LONG
TERM AS THE UPPER LOW FINALLY MOVES OFF TO THE EAST ACROSS
OHIO...BEFORE FINALLY MOVING ACROSS NEW ENGLAND BY MID WEEK. LIGHT
SNOW SHOWERS WILL CONTINUE TO OCCUR THROUGH THE FIRST PART OF THE
WEEK UNDER THE INFLUENCE OF THE UPPER LEVEL LOW...ESPECIALLY IN
FAVORED UPSLOPE AREAS IN THE NORTHERN AND CENTRAL MOUNTAINS IN THE
NW FLOW BEHIND THE LOW AS IT CONTINUES TO MOVE EASTWARD. A BRIEF
BREAK IS EXPECTED IN THE PRECIPITATION MID WEEK AS HIGH PRESSURE
ATTEMPTS TO BRIEFLY BUILD IN...BUT ANOTHER SYSTEM IS EXPECTED TO
ARRIVE LATE IN THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE REST OF THE AFTERNOON AND
EVENING. SOME MVFR TO IFR POSSIBLE AT EKN AND CRW UNDER MOSTLY SCT
HIGH TO MID CLOUDS BETWEEN 05Z-12Z. CLOUDS INCREASE THROUGH 18Z
THURSDAY.
AFTER 18Z THURSDAY...
SYSTEM IMPACTS AREA THURSDAY NIGHT INTO FRIDAY...WITH RAIN AND
POSSIBLE IFR. FREEZING RAIN ALSO A THREAT IN THE WV MOUNTAIN
VALLEYS...AND LOW LEVEL WIND SHEAR NOT OUT OF THE QUESTION AREAWIDE
FRIDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...MDP/JS/JMV
NEAR TERM...JS
SHORT TERM...JMV
LONG TERM...SL/JMV
AVIATION...JS
