-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 022004
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
304 PM EST SUN MAR 2 2014

.SYNOPSIS...
POTENT WINTER SYSTEM INTO MONDAY WITH NORTH TO SOUTH COOLING DURING
THE STORM.  DRIER AND COLD AIR QUICKLY RETURNS MONDAY AFTERNOON AND
NIGHT.

&&

.NEAR TERM /THROUGH MONDAY/...
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FIRST WAVE AND S/W TROF EXITING OFF TO NE AS OF 19Z. CURRENTLY IN A
LULL ACROSS SE OH AND W WV WITH A SUBTLE WAVE INBOUND WITH PERHAPS
AN UPTICK IN PRECIP ACROSS SE OH IN THE 21 TO 00Z TIME FRAME.
REPORTS THUS FAR INDICATE A TENTH TO QUARTER INCH OF ICE ACCRETION
ACROSS PORTIONS OF SE OH WITH A FEW INCHES OF SNOW/SLEET TO BOOT.
FRONTAL BOUNDARY LOOKS TO BE ROLLING INTO THE MOUNTAINS CURRENTLY.
COLD AIR IN BL REALLY DID NOT BUDGE MUCH DURING THE HEAVY PRECIP
FROM FIRST WAVE...FROM INITIAL PENETRATION. SHOULD SEE A FURTHER S
PUSH OF LOW LEVEL COLD AIR NEXT SEVERAL HOURS...BEHIND THIS INITIAL
WAVE.

TRENDS STILL HOLDING FOR A S SHIFT IN MAX QPF AXIS WITH THE MORE
POTENT WAVE TONIGHT. AS SUCH MADE SOME CHANGES WITH THE ICE/SNOW
TOTALS TO DECREASE AMOUNTS N OF I64 AND SE OH. ON THE FLIP
SIDE...HAD TO INCREASE THE SNOW/ICE ALONG AND ESPECIALLY S OF I64
CORRIDOR. TRIED TO ALLOW SOME WIGGLE ROOM FOR ANY WOBBLE BACK NORTH
WITH QPF AXIS. SEE PREVIOUS DISCUSSION BELOW REGARDING
AMOUNTS...AS THAT THINKING STILL HOLDS TRUE WITH THIS ISSUANCE.
OVERALL HEADLINES WILL REMAIN. DO THINK SE OH/NE KY/W WV COULD BE
ENDED EARLY AND WILL PASS THIS ALONG TO EVENING SHIFT FOR ANY
ADJUSTMENTS WITH ENDING TIMES.

ALSO WILL BE MONITORING WATER PROBLEMS ACROSS THE S COAL FIELDS/SE
WV INTO THIS EVENING...BEFORE THE CHANGEOVER.

PREVIOUS DISCUSSION BELOW...

SOME NOTABLE TRENDS IN THE 12Z NAM AND LATEST RUC/HRRR. SEEMS
INITIAL PUSH OF BOUNDARY IS A LITTLE S COMPARED TO LAST NIGHTS
RUNS BEHIND THE INITIAL WAVE. THIS WOULD SHIFT MAIN QPF AXIS WITH
SECOND...MORE POTENT...WAVE AND S/W TROF FURTHER S. GENERALLY
SOUTH OF METRO I64 CORRIDOR AND ACROSS THE C AND S WV MOUNTAINS.
THIS WOULD SUGGEST LESS QPF AND THUS LESS ICE/SNOW ACROSS N WV AND
SE OH. MAY BE KNOCKING THE FREEZING RAIN TOTALS DOWN SOME ACROSS
THE N AND ALSO THE SNOW TOTALS. ALONG THE METRO 64 CORRIDOR FROM
HTS TO CRW...APPEARS THE BEST THREAT FOR ICE ACCRETION WOULD BE
FROM 00 TO 03Z GIVE OR TAKE AN HOUR. AFTER THAT...DEPTH OF COLD
AIR IS FORECAST TO DEEPEN ENOUGH FOR MAINLY SLEET AS THE NEXT
SURGE OF PRECIP MOVES IN FROM THE W WITH THE NEXT WAVE AND S/W
TROF APPROACHING. NAM/RUC/HRRR SUGGESTS A LULL IN PRECIP ACROSS THIS
AREA BEFORE THE NEXT SURGE MOVES IN WHICH WOULD LESSEN ICE
ACCRETION. TRANSITION TO SNOW ACROSS THOSE LOCALES SHOULD BE
COMPLETE 05-07Z. AS A RESULT...MAY BE LOOKING AT MORE SLEET IN
THIS CORRIDOR THAN ICE SHOULD THESE TRENDS HOLD. WITH THE S SHIFT
OF QPF AXIS FROM SECOND WAVE...THE COAL FIELDS OVER TO SE WV MAY
BE IN LINE FOR THE MAJOR ICE ACCRETION...ON THE ORDER OF HALF AN
INCH TO THREE QUARTERS OF AN INCH. AS THE DEPTH OF COLDER AIR
INCREASES DOWN THERE BY 09Z...SWITCH TO HEAVY SNOW WILL OCCUR WITH
NAM SUGGESTING A SWATCH OF 8 TO 12 INCHES ON TOP OF THE
ICE/SLEET...WITH AMOUNTS TAPERING OFF FURTHER N...WITH 4 TO 6
ALONG HTS TO CRW LINE. IT SHOULD BE NOTED THAT THIS IS A NARROW
ZONE OF 50 MILES OR SO THAT COULD CHANGE ON FUTURE RUNS THIS
AFTERNOON. WILL BE WATCHING HOW FAR S THE BOUNDARY GETS WITH THIS
INITIAL WAVE TODAY. NEEDLESS TO SAY...ANYONE WITHIN THIS MAIN QPF
AXIS ON THE SECOND WAVE STANDS THE GREATEST CHANCE OF SEEING THE
WORST OF THIS STORM IN TERMS OF ICE AND HEAVY SNOW ON TOP OF THAT.

WILL HAVE HEADLINES WITH UPDATED FORECAST THINKING CONCERNING
AMOUNTS BY LUNCH TIME.
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
FOR ABOUT 3 TO 5 HOURS 12Z TO 15Z/17Z THE MAIN SUPPORT FROM THE
RIGHT REAR OF A STRENGTHENING 250 MB JET MAX WILL BE STILL PASSING
THROUGH. THAT 250 MB JET MAX GOES FROM AROUND 150 KNOTS TONIGHT TO
180 KNOTS MONDAY MORNING. THINKING THIS WILL ENHANCE THE SNOW MOSTLY
EKN-CRW-LNP CORRIDOR ON EAST...INCLUDING BKW.  SO MODERATE TO HEAVY
SNOW POSSIBLE FOR A FEW HOURS IN THE CENTRAL AND SRN WV MOUNTAINS
BEFORE THAT SUPPORT EXITS BY 18Z MONDAY.  COULD NOT RULE OUT T ON
EITHER SIDE OF 12Z IN SOUTHERN COUNTIES SO POT GRIDS ARE 5 TO 10
PERCENT NOT ZERO. THE LAST OF THE FREEZING RAIN AND SLEET SHOULD BE
CHANGING TO SNOW IN VIRGINIA AT 12Z MONDAY.  HAVE A SHARP NORTHWEST
EDGE TO THE 12Z TO 18Z SNOW ACCUMULATION WITH A 6 TO 7 INCH MAXIMUM
BETWEEN EKN AND BKW IN THE CENTRAL WV MOUNTAINS. SO HAVE LOWERED
SNOW AMOUNTS FOR 12Z TO 18Z MONDAY FOR THE HTS-PKB-CKB AREA ON
NW...THINKING THOSE COUNTIES TOO FAR NORTH AND WEST.

OF COURSE...THAT SHARP GRADIENT COULD SHIFT...IF THE WAVE IS A FEW
HOURS SLOWER OR FASTER THAN THIS DETERMINISTIC FORECAST HAS.

WILL BE FASTER LOWERING POPS FROM NNW TO SSE ON MONDAY. SOME 925 TO
805 MOISTURE MAY TRY TO REFORM SCATTERED LOWER CLOUDS AFTER THE
LAYERED CLOUDS EXIT...BUT NO FLAKES FIGURED IN THOSE LOWER
CLOUDS.

HAVE TEMPERATURES STILL DROPPING IN MANY COUNTIES 12Z TO 14Z
MONDAY.  READINGS RECOVER A FEW DEGREES IN THE WEST DURING THE
AFTERNOON WITH THAT PARTIAL CLEARING.  A COLD MID WINTER LIKE NIGHT
FOR MONDAY NIGHT INTO TUESDAY MORNING.  WITH THE FRESH SNOW
COVER...HAVE SOME BELOW ZERO IN SOUTHEAST OHIO AND IN THE MOUNTAIN
VALLEYS.

NO SIGNIFICANT CHANGES MADE TO TUESDAY NIGHT INTO WEDNESDAY.  LEFT
THE SLIGHT CHANCE POP ACROSS THE NORTH FOR OVERNIGHT TUESDAY
NIGHT...BUT BASICALLY A DRY PATTERN THROUGH WEDNESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
BY MONDAY NIGHT...FRONTAL SYSTEM WILL BE EAST OF THE
APPALACHIANS...WHILE AN UPPER TROUGH...EVIDENT AT H5 VORTICITY MAX
PASSES JUST NORTH OF THE AREA. THE CMC/ECMWF/GFS KEEP THIS
FEATURE ACROSS PA THROUGH EARLY TUESDAY MORNING. THE NAM IS THE
ONLY MODEL BRINGING VORTICITY MAX FURTHER SOUTH INTO THE OH VALLEY
AND WV BY 00Z TUESDAY.

THE GFS AND ECMWF INDICATE COLD AIR FILTERING BEHIND THE
FRONT...EVIDENT N H85 TEMPERATURES GETTING INTO THE MINUS 11C BY
00Z TUESDAY. BY THIS TIME AND THE REST OF MONDAY NIGHT MOST PCPN
SHOULD BE EAST OF THE MOUNTAINS EXCEPT FOR UPSLOPE SNOW OVER THE
EASTERN MOUNTAINS FOR ANY LINGERING LOW LEVEL MOISTURE THROUGH 12Z
TUESDAY. THEREFORE...REFINED LIKELY POPS OVER THE PREFERRED UPSLOPE
AREA UNDER NORTHERLY FLOW.

A CANADIAN HIGH PRESSURE BUILDS IN FROM THE NORTHWEST...AND MOVES
EAST ACROSS THE GREAT LAKES INTO THE NORTHEAST STATES WEDNESDAY
AND WEDNESDAY NIGHT.

GFS AND ECMWF BOTH START BRINGING WARMER AIR FROM THE SOUTH AND
SOUTHWEST BY 06Z WEDNESDAY...INCREASING SOME FOR A GRADUAL WARMING
TREND WEDNESDAY AND THURSDAY. REMOVED PCPN WITH THE HIGH
PRESSURE DUE TO LACK OF MOISTURE AND FORCING WEDNESDAY AND
THURSDAY.

WENT WITH WARMER HPC GUIDANCE FOR HIGHS THROUGH THE PERIOD.
POPULATED HPC LOWS WITH LOOK LOWER THAN PREVIOUS ISSUANCE. TWEAKED
LOWS DOWN TO BETTER MATCH WITH NEIGHBORING OFFICES.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
WIDESPREAD IFR CONDITIONS WITH PASSING OF SURFACE WAVE. ACTUAL COLD
FRONT SAGGING THROUGH MOUNTAINS AS OF 18Z. BRIEF LULL IN PRECIP SE
OH/NE KY/W WV BEFORE NEXT SURGE OF PRECIP WORKS IN THIS EVENING.
HAVE MIXED PRECIP CHANGING TO ALL SNOW OVERNIGHT WITH CONTINUED IFR
CONDITIONS WITH SOME LIFR VSBY IN THE SNOW FOR KCRW/KBKW/KEKN.
CONDITIONS GRADUALLY IMPROVE ON MONDAY AS THE SYSTEM EXITS OFF TO
THE NE BY 18Z.

FLOW WILL TURN NORTH BEHIND THE FRONT.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: TIMING PRECIP TYPE CHANGEOVER MAY VARY A FEW
HOURS AND AS A RESULT FLIGHT CONDITIONS.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       20   21   22   23   00   01   02   03   04   05   06   07
EST 1HRLY       15   16   17   18   19   20   21   22   23   00   01   02
CRW CONSISTENCY  H    H    L    H    H    H    H    H    H    H    M    M
HTS CONSISTENCY  H    H    H    H    H    H    L    L    M    M    M    M
BKW CONSISTENCY  H    H    L    L    L    L    L    L    L    L    L    H
EKN CONSISTENCY  L    L    L    M    M    M    M    M    M    M    M    M
PKB CONSISTENCY  H    H    H    H    H    M    H    H    M    M    M    L
CKB CONSISTENCY  H    H    H    H    M    M    M    M    M    M    M    M

AFTER 18Z MONDAY...
WIDESPREAD IFR IN WINTER PRECIPITATION LINGERS INTO MONDAY MAINLY
ACROSS CENTRAL AND EASTERN CWA.
-- End Changed Discussion --

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
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WV...WINTER STORM WARNING UNTIL 4 PM EST MONDAY FOR WVZ005>008-014-
     016>020-029>032-039-040.
     WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST MONDAY
     FOR WVZ033>036.
     WINTER STORM WARNING UNTIL 4 PM EST MONDAY FOR WVZ013-015-
     024>028-037-038-046-047.
     WINTER STORM WARNING UNTIL 10 AM EST MONDAY FOR WVZ009>011.
OH...WINTER STORM WARNING UNTIL 4 PM EST MONDAY FOR OHZ087.
     WINTER STORM WARNING UNTIL 10 AM EST MONDAY FOR OHZ066-067-075-
     076-083>086.
KY...WINTER STORM WARNING UNTIL 4 PM EST MONDAY FOR KYZ101>103-105.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST MONDAY
     FOR VAZ003-004.
-- End Changed Discussion --

&&

$$
SYNOPSIS...RPY/JMV/30
NEAR TERM...30
SHORT TERM...KTB
LONG TERM...RPY
AVIATION...30