280
FXUS61 KRNK 221911
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
211 PM EST SUN DEC 22 2024
SYNOPSIS
THE HIGH PRESSURE SYSTEM WILL MOVE EAST TODAY AND OFFSHORE
TONIGHT. ON MONDAY, A LOW PRESSURE SYSTEM TRACKS ACROSS THE
GREAT LAKES WHICH THEN BRINGS A CHANCE OF PRECIPITATION TO THE
CENTRAL APPALACHIANS ON TUESDAY. A COASTAL SYSTEM BRINGS A
CHANCE OF FREEZING RAIN TO THE VA/NC PIEDMONT ON TUESDAY AS
WELL.
NEAR TERM /THROUGH TONIGHT/
AS OF 200 PM EST SUNDAY...
KEY MESSAGES:
1) COLD AND MOSTLY CLEAR SKIES TODAY
THE NORTHEASTERN SURFACE HIGH CONTINUES TO MIGRATE TOWARDS THE
ATLANTIC AND WILL CAUSE A SHIFT IN WIND DIRECTION FROM THE EAST AND
THEN FROM THE SOUTH BY MONDAY EVENING. SOUTHERLY WINDS WILL BE AIDED
BY A SURFACE LOW PRESSURE SYSTEM MAKING ITS WAY EAST THROUGH THE
GREAT LAKES. THIS SYSTEM IS CURRENTLY PROJECTED TO JUST MISS OUR
REGION WITH A SMALL CHANCE OF GRAZING AND GIVING THE MOST NORTHERN
MOUNTAINOUS COUNTIES A CHANCE OF PRECIPITATION.
IN THE MEANTIME, IT WILL BE ANOTHER COLD ONE WITH HIGHS TODAY IN THE
30S FOR MOST OF THE REGION. WINDS WILL BE RELATIVELY QUIET BUT
OVERNIGHT TEMPERATURES ARE STILL EXPECTED TO BE IN THE 20S AND
TEENS, PARTICULARLY AT HIGHER ELEVATIONS. AREAS THAT STILL HAVE SNOW
ON THE GROUND CAN EXPECT TO BE COLDER THAN SURROUNDING LOCATIONS.
THE HIGH TEMPERATURES ON MONDAY ARE EXPECTED TO BE SUBTLY WARMER AS
500MB HEIGHTS INCREASE AND BECOME MORE ZONAL OVER THE MID-ATLANTIC.
SKIES WILL BE REMAIN CLEAR FOR MOST OF THIS PORTION OF THE FORECAST
PERIOD. CIRRUS MAY PASS THROUGH LATER THIS EVENING BETWEEN 5-9PM BUT
WIDESPREAD CLOUD COVER WILL LIKELY RETURN AS THE SURFACE LOW
PRESSURE SYSTEM GETS CLOSER.
CONFIDENCE IN TEMPERATURE FORECAST IS HIGH.
CONFIDENCE IN PRECIPITATION FORECAST IS LOW.
CONFIDENCE IN CLOUD COVERAGE IS AVERAGE.
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY /
AS OF 200 PM EST SUNDAY...
KEY MESSAGES:
1) SLIGHT RAIN CHANCES WILL BE POSSIBLE ACROSS THE NC AND VA
PIEDMONT TUESDAY MORNING.
2) FREEZING RAIN MAY BE POSSIBLE EARLY TUESDAY ACROSS THE PIEDMONT;
HOWEVER, FREEZING RAIN ACCUMULATION LOOKS TO REMAIN AROUND 0.01.
SURFACE HIGH PRESSURE WILL LINGER ACROSS THE AREA ON MONDAY;
HOWEVER, A MORE ACTIVE UPPER LEVEL PATTERN LOOKS TO BRING MINIMAL
RAIN CHANCES TO THE AREA EARLY TUESDAY MORNING.
AS HIGH PRESSURE BREAKS DOWN ACROSS THE REGION TUESDAY MORNING, A
NEGATIVELY TILTED SHORTWAVE TROUGH LOOKS TO PROGRESS THROUGH THE
EASTERN GREAT LAKES AND NEW YORK. AT THE SAME TIME, A WEAK SHORTWAVE
EMBEDDED IN THE SOUTHERN JET STREAM LOOKS TO PROGRESS THROUGH
GEORGIA AND THE CAROLINAS. THIS SOUTHERN SYSTEM HAS ENSEMBLE SUPPORT
OF DEVELOPING AN INVERTED SURFACE TROUGH ALONG THE BAROCLINIC ZONE
OFF THE CAROLINA'S COASTLINE. THIS MAY BRING LIGHT RAIN SHOWERS TO
THE PIEDMONT, WITH INITIAL PRECIPITATION TYPE FALLING AS FREEZING
RAIN FOR SOME. THE THE LARGEST PRECIPITATION AXIS REMAINING PRIMARILY
ACROSS THE NORTH AND SOUTH CAROLINA PIEDMONT, IT IS UNLIKELY THAT
THESE AREAS WILL SEE MUCH MORE THAN 0.01 INCHES OF FREEZING RAIN
BEFORE TEMPERATURES WARM UP AND TRANSITIONS TO ALL RAIN FOR THE
REMAINDER OF THE MORNING. THE AFOREMENTIONED NORTHERN STREAM SYSTEM
MAY BRING LIGHT SNOW SHOWERS EARLY TO WESTERN GREENBRIER COUNTY AS A
TRAILING VORTICITY STREAMER FROM THE MAIN SHORTWAVE PROGRESSES
THROUGH NORTHERN WEST VIRGINIA EARLY TUESDAY.
BY TUESDAY AFTERNOON INTO THE EVENING, A MORE AMPLIFIED SHORTWAVE
TROUGH ACROSS THE CENTRAL PLAINS EXTENDING FROM SOUTH TEXAS TOWARDS
SOUTH CENTRAL CANADA IS EXPECTED TO LEAD TO ENHANCED RIDGE BUILDING
ACROSS THE SOUTHEAST. THIS RIDGE BUILDING LOOKS TO CREATE AN
ENHANCED ZONE OF CONVERGENCE ALOFT OVER THE REGION, WHICH SEEMS TO
CREATE ENOUGH SUBSIDENCE OVER THE AREA THAT PRECIPITATION FROM THE
TWO PREVIOUSLY DISCUSSED SYSTEMS LOOK TO END BY MID DAY TUESDAY.
BY WEDNESDAY, SURFACE HIGH PRESSURE LOOKS TO SETTLE INTO NEW ENGLAND
AHEAD OF THE AFOREMENTIONED CENTRAL PLAINS SHORTWAVE. AS THE HIGH
PRESSURE SETTLES INTO THE NORTHEAST, WEDGING IS EXPECTED TO DEVELOP
EAST OF THE APPALACHIANS STARTING WEDNESDAY. WHILE THIS WILL KEEP THE
AREA DRY, THE REGION IS EXPECTED TO BE MOSTLY COVERED IN CLOUD
COVER, WHICH WILL KEEP TEMPERATURES NEAR NORMAL.
OUTSIDE OF THE SLIGHT RAIN CHANCES EARLY TUESDAY MORNING, HIGH
TEMPERATURES TUESDAY LOOK TO CLIMB INTO THE UPPER 40S TO LOW 50S
ACROSS THE AREA. LOWS WILL GENERALLY REMAIN IN THE UPPER 20S TO LOW
30S TUESDAY NIGHT, AND CLIMB INTO THE MID TO UPPER 40S WEDNESDAY.
/CONFIDENCE LEVELS IN FORECAST PARAMETERS/
- MODERATE TO HIGH CONFIDENCE IN TEMPERATURES
- LOW TO MODERATE CONFIDENCE IN PRECIPITATION PROBABILITIES
LONG TERM /THURSDAY THROUGH SUNDAY/
AS OF 200 PM EST SUNDAY...
KEY MESSAGES:
1) MINIMAL RAIN CHANCES EXPECTED, WITH AN UNSETTLED WEATHER PATTERN
BEYOND CHRISTMAS.
2) NEAR NORMAL TEMPERATURES ARE EXPECTED TO END THE HOLIDAY WEEK.
A COMPLEX AND ACTIVE WEATHER PATTERN LOOKS TO DEVELOP ACROSS THE
CONUS TO WRAP UP 2024. THE AFOREMENTIONED SHORTWAVE ACROSS THE
CENTRAL UNITED STATES ON TUESDAY IS EXPECTED TO SLOWLY PROGRESS INTO
THE AREA ON THURSDAY MORNING; HOWEVER, A MORE POTENT AND AMPLIFIED
UPSTREAM TROUGH PUSHING INTO NORTHWEST TEXAS IS EXPECTED TO AMPLIFY
THE RIDGE DOWNSTREAM ACROSS THE EASTERN CONUS. THIS RIDGE
AMPLIFICATION IS EXPECTED TO ELONGATE THE PREVIOUSLY DISCUSSED
SHORTWAVE MOVING INTO THE REGION THURSDAY. WHILE PRECIPITATION
CHANCES WILL BE POSSIBLE, THEY LOOK TO REMAIN LOW FOR THE TIME BEING
AS ANY FORCING FOR ASCENT IS QUICKLY DIMINISHED BY LARGER SCALE
SUBSIDENCE. GIVEN THIS RIDGE AMPLIFICATION, THE WEST TEXAS TROUGH
LOOKS TO LIFT NORTHEAST INTO THE WESTERN GREAT LAKES REGION BY
FRIDAY MORNING. THIS WILL CONTINUE TO KEEP THE REGION DRY AT THIS
TIME THROUGH AT LEAST THE EARLY WEEKEND. WHILE UPPER LEVEL RIDGING
WILL BE IN PLACE, TEMPERATURES WILL BE PRIMARILY NEAR NORMAL DUE TO
THE INCREASED CLOUD COVER FROM ALL OF THE AFOREMENTIONED SHORTWAVES
MOVING THROUGH THE REGION. THIS WILL MAKE IT DIFFICULT FOR ANY
SIGNIFICANT WARM TEMPERATURES TO DEVELOP DURING THE END OF THE
HOLIDAY WEEK AND INTO THE WEEKEND. TEMPERATURES OVERALL LOOK TO
REMAIN NEAR TO SLIGHTLY ABOVE NORMAL, WITH OVERNIGHT LOWS REMAINING
A TOUCH ON THE WARMER SIDE ACROSS THE REGION.
/CONFIDENCE LEVELS IN FORECAST PARAMETERS/
- MODERATE CONFIDENCE IN TEMPERATURES
- MODERATE CONFIDENCE IN PRECIPITATION PROBABILITIES
AVIATION /19Z SUNDAY THROUGH FRIDAY/
AS OF 200 PM EST SUNDAY...
CLEAR SKIES THIS MORNING/EARLY AFTERNOON WITH VFR CONDITIONS AT ALL
TERMINALS. WINDS ARE EXPECTED TO BECOME MORE EASTERLY (BUT WEAK) AS
THE NORTHERN SURFACE HIGH PRESSURE SYSTEM MOVES TOWARDS THE ATLANTIC.
ONLY WEATHER OF NOTE IS A PLUME OF CIRRUS THAT IS LIKELY TO PASS
OVER ALL TERMINALS AROUND 5PM-9PM THIS EVENING.
CONFIDENCE IN THIS FORECAST IS ABOVE AVERAGE.
EXTENDED AVIATION OUTLOOK...
TERMINAL CONDITIONS ARE DEPENDENT ON A SERIES OF SHORTWAVES THAT
WILL MAKE THEIR WAY THROUGH THE UNITED STATES LATER THIS WEEK. MOST
OF THESE SYSTEMS ARE EXPECTED TO BE DIVERTED WELL AWAY FROM THE
REGION BUT TWO SYSTEMS OF NOTE MAY AT LEAST BRING MVFR CONDITIONS TO
KLWB AND KDAN IN THE COMING DAYS. THESE STORM SYSTEMS ARE HEAVILY
DEPENDENT ON A RIDGE OVER THE MID-ATLANTIC SO THERE IS A LOT OF
UNCERTAINTY IN THIS EXTENDED AVIATION FORECAST.
CONFIDENCE IN THIS FORECAST IS LOW.
RNK WATCHES/WARNINGS/ADVISORIES
VA...NONE.
NC...NONE.
WV...NONE.
SYNOPSIS...AMS/CG
NEAR TERM...CG
SHORT TERM...EB
LONG TERM...EB
AVIATION...CG
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