043
FXUS62 KCAE 170328
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1028 PM EST THU JAN 16 2025
SYNOPSIS
DRY AND SEASONABLE TEMPERATURES THROUGH FRIDAY WITH HIGH
PRESSURE OVER THE AREA. WIDESPREAD SHOWERS EXPECTED SATURDAY AS
A LOW PRESSURE SYSTEM MOVES INTO THE EASTERN U.S. BEHIND THE
SYSTEM, EXPECT WELL BELOW NORMAL TEMPERATURES AS A ANOMALOUSLY
DEEP TROUGH AND SURFACE HIGH PUSHES AN ARCTIC AIR MASS INTO THE
CENTRAL AND EASTERN US. BY THE MIDDLE OF NEXT WEEK, A COASTAL
LOW WILL LIKELY INCREASE PRECIPITATION CHANCES WITH SOME WINTRY
POTENTIAL POSSIBLE BUT STILL UNCERTAIN.
NEAR TERM /UNTIL 7 AM FRIDAY MORNING/
KEY MESSAGE(S):
- BREEZY WINDS CONTINUE ON AREA LAKES.
HIGH PRESSURE CONTINUING TO RIDGE OVER THE AREA WITH CLEAR SKIES
EXPECTED OVERNIGHT. A LINGERING PRESSURE GRADIENT REMAINS IN
PLACE AND WHILE THE STRONGEST GUSTS HAVE SUBSIDED AS A SURFACE
INVERSION HAS DEVELOPING, A LOW LEVEL JET AROUND 925MB WILL
REMAIN STRONG WITH HIRES FORECAST SOUNDINGS INDICATING IT WILL
BE BETWEEN 30 TO 35 KNOTS. WHILE FOR THE MOST PART, THIS WILL
NOT MIX DOWN OVER LAND, SOMEWHAT MORE FAVORABLE MIXING OVER
LAKES MAY LEAD TO SOME BREEZY WINDS ON AREA LAKES. LOWS TONIGHT
EXPECTED TO DROP TO NEAR FREEZING.
SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/
KEY MESSAGE(S):
- DRY HIGH PRESSURE IN PLACE FRIDAY. SHOWERS MOVE IN SATURDAY
AHEAD OF A STRONG FRONT.
SURFACE HIGH PRESSURE WILL SHIFT THROUGHOUT FRIDAY AS FAIRLY
PROGRESSIVE FLOW ACROSS THE SOUTHERN US CONTINUES. CLEAR SKIES AND
TEMPS RIGHT AROUND AVERAGE ARE EXPECTED WITH LIGHT WINDS, EVENTUALLY
TURNING OUT OF THE SOUTH BY THE EVENING. DEW POINTS WILL STEADILY
INCREASE CONSEQUENTLY OVERNIGHT INTO SATURDAY MORNING AS STRONG
SOUTHERLY FLOW APPROACHES FROM THE WEST. A MODEST PLUME OF
MOISTURE AHEAD OF THE SURFACE LOW WILL PUSH INTO OUR AREA BY
SATURDAY MORNING, BUT THE PROGRESSIVE NATURE OF THE DRIVING
SHORTWAVE AND EXTREMELY DRY AIRMASS IN PLACE CURRENTLY WILL
DRASTICALLY LIMIT THE NORTHERN EXTENT OF THE DEEPEST MOISTURE.
PWAT'S ACROSS THE CSRA SHOULD STILL CLIMB INTO THE 1.0-1.25"
RANGE AND THERE WILL BE STRONG, BUT SHORT LIVED, ISENTROPIC LIFT
AND WARM ADVECTION THROUGHOUT SATURDAY MORNING-EARLY AFTERNOON.
POP'S ARE HIGH ACROSS THE ENTIRE AREA, BUT QPF TOTALS ARE
RELATIVELY LOW; 0.50-0.75 IN THE CSRA, FALLING TO THE NORTH WITH
0.2-0.5 IN THE MIDLANDS. AS THIS INITIAL SURFACE LOW AND MID-
LEVEL SHORTWAVE MOVES OFFSHORE LATE SATURDAY, THERE IS SOME
POTENTIAL FOR PRECIP REDEVELOPING WEST- NORTHWEST OF THE SURFACE
LOW, AND ALONG THE STALLING SURFACE FRONT, AS ANOTHER VORT LOBE
SWINGS DOWN ACROSS THE DEEP SOUTH AS PART OF THE PRIMARY LONG
WAVE TROUGH AXIS. MOST GUIDANCE NOW SHOW SOME REDEVELOPMENT AS
LINGERING SCATTERED SHOWER ACTIVITY THROUGHOUT SATURDAY NIGHT
INTO SUNDAY MORNING BUT QPF WILL REMAIN LOW.
LONG TERM /SUNDAY THROUGH THURSDAY/
KEY MESSAGE(S):
- A VERY STRONG COLD FRONT ARRIVES LATE SUNDAY AS THE LINGERING
SURFACE LOW LIFTS NORTHEAST.
- TEMPS 15-25 DEGREES BELOW AVERAGE EXPECTED MONDAY THROUGH THURSDAY.
- WINTRY PRECIP CHANCES CONTINUE FOR MID-WEEK, BUT CONFIDENCE
REMAINS LOW.
THE AFOREMENTIONED SURFACE LOW WILL LIFT NORTHEAST SUNDAY, FOLLOWED
BY THE LONG DISCUSSED COLD FRONT. SO THERE WILL NOT LIKELY BE
MUCH OF A DIURNAL SWING SUNDAY AS STRONG ADVECTION ARRIVES
DURING THE DAY. FOR MONDAY AND TUESDAY, THE BROAD TROUGH OF THE
ARCTIC AIRMASS WILL SETTLE INTO THE CENTRAL AND EASTERN US. EC
AND NAEFS ARE IN EXCELLENT AGREEMENT OVER THE GENERAL NATURE OF
THE INITIAL AIRMASS WITH HIGHLY ANOMALOUS COLD, BUT NOT RECORD
SETTING; TEMPS 15-25 DEGREES BELOW AVERAGE YIELD HIGHS IN THE
~30'S OR LOW 40'S, ALONG WITH OVERNIGHT LOWS IN THE TEENS OR LOW
20'. EC EFI CONTINUES TO SHOW EFI VALUES BETWEEN 0.9 AND 0.95
MONDAY AND TUESDAY, BUT SOT IS VERY LOW; A CLASSIC HIGH
CONFIDENCE IN WELL BELOW AVERAGE, BUT NOT EXTREME TEMPS, SIGNAL.
REGARDLESS, THE LREF OUTPUT SUGGESTS WE WILL APPROACH OR EXCEED
COLD WEATHER ADVISORY CRITERIA AT SOME POINT NEXT WEEK, SO STAY
AWARE OF THAT POTENTIAL NEW PRODUCT ISSUANCE. FROZEN PIPES AND
RELATED IMPACTS ARE BECOMING MORE LIKELY DURING THE MID- WEEK
PERIOD AS HIGH TEMPS WILL ONLY MAKE IT ABOVE FREEZING FOR A FEW
HOURS EACH DAY.
LATE TUESDAY AND INTO WEDNESDAY IS WHEN THE WINTRY PRECIP POTENTIAL
STARTS TO ENTER THE PICTURE. BASED ON THE LAST HANDFUL OF GUIDANCE
SUITES, THERE IS ONLY A LITTLE MORE CLARITY ON THE POSSIBILITY OF
WINTER WEATHER NEXT WEEK. BASED ON EXTENT OF THE COLD AIRMASS AND
ASSOCIATED SURFACE HIGH PRESSURE, A SUPPRESSED LOW TRACK
SOLUTION LOOKS MORE AND MORE LIKELY WITH ANY WINTRY PRECIP
CHANCES ACTUALLY INCREASING THE FURTHER SOUTH YOU GO IN THE
MIDLANDS AND CSRA. GEFS, AND ECE TO A LESSER EXTENT, HAVE
TRENDED TOWARDS THIS SOLUTION OVER THE PAST SEVERAL RUNS WITH
PROBABILITIES OF 1" OF SNOW IN THE CENTRAL AND NORTHERN
MIDLANDS DECREASING NOTABLY AS THE SURFACE HIGH SETTLES INTO THE
TN VALLEY. THE GEFS AND DETERMINISTIC GFS REMAIN THE MOST
SUPPRESSED, WITH LITTLE-NO PRECIP INTO THE FORECAST AREA. THE
CANADIAN AND AT ITS ENSEMBLE ARE THE OTHER END OF THE SPECTRUM,
WITH A NORTHERN GOM ORIENTED STORM TRACK AND SIGNIFICANTLY MORE
MOISTURE OVERRUN INTO EASTERN GA AND SC; THE EC AND ITS
ENSEMBLE LOOKS TO BE DIRECTLY IN THE MIDDLE OF THESE TWO
SOLUTIONS OVER THE LAST FEWS SUITES. THE KEY FEATURE OF THE
FORECAST IS HOW THE LOW LEVEL COLD AIR AND SURFACE HIGH PRESSURE
IS HANDLED AND HOW FAR SOUTHEAST IT CAN REACH. HOW THIS HIGH
PRESSURE PROGRESSES IS A RESULT OF EXTREMELY STRONG CONFLUENCE
ALONG THE WESTERN FLANK OF THE TROUGH MAIN TROUGH. AND HOW THIS
CONFLUENCE PROGRESSES IS A RESULT OF A CUTOFF LOW IN THE PACIFIC
AND ITS INTERACTION WITH THE MAIN TROUGH. A FASTER PHASE OF
THIS CUTOFF DRAGS THE SURFACE HIGH FURTHER WEST, AND A SLOWER
PHASE CAUSES THE OPPOSITE. UNFORTUNATELY WITH CHAOTIC NATURE OF
CUTOFFS SITTING UNDER RIDGE AXES, IT WILL TAKE SEVERAL MORE DAYS
TO GET CONSISTENT MODEL GUIDANCE ON THIS EVENT. BUT GENERALLY,
THE GFS-EC SOLUTION OF A SLOWER DECAY OF THE CUTOFF-RIDGE
PATTERN IN THE PACIFIC IS MORE LIKELY GIVEN TYPICAL MODEL BIASES
IN BLOCKING PATTERNS.
OVERALL, THE FORECAST HINGES ON A NOTORIOUS SYNOPTIC SCALE
INTERACTION. BUT BEYOND THAT THE GENERAL PATTERN IS FAVORABLE
WITH A SUPPRESSED GOM STORM TRACK SOLUTION LOOKING LIKELY.
WHETHER THAT YIELDS SNOW- WINTRY PRECIP INTO THE MIDLANDS AND
CSRA IS HIGHLY UNCERTAIN AT THIS TIME.
AVIATION /04Z FRIDAY THROUGH TUESDAY/
VFR CONDITIONS THROUGH THE TAF PERIOD.
SKIES REMAIN CLEAR ACROSS THE REGION THIS EVENING AS HIGH
PRESSURE BUILDS IN FROM THE WEST. AS EXPECTED, WINDS AT THE
TERMINALS HAVE DIMINISHED, NOW THAT THE NOCTURNAL INVERSION HAS
SET UP. WINDS DURING THE NEXT FEW HOURS WILL GENERALLY BE
BETWEEN 5 AND 10 KNOTS, BECOMING LIGHT AND VARIABLE. THE LIGHT
WINDS AND CLEAR SKIES SHOULD CONTINUE INTO FRIDAY WITH
MID TO HIGH LEVEL CLOUDINESS ARRIVING NEAR THE END OF THE
CURRENT TAF PERIOD.
EXTENDED AVIATION OUTLOOK...THE NEXT CHANCE FOR SIGNIFICANT
RESTRICTIONS WILL BE LATE FRIDAY AND SATURDAY AS MOISTURE
SPREADS INTO THE SOUTHEAST.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
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