Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/23/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
823 PM MST FRI NOV 22 2013
.UPDATE...OBSERVATIONS IN THE MOUNTAINS ARE INDICATING DECENT
EASTERLY FLOW OVER THE RIDGES. WITH THE UPPER LOW REMAINING WELL
TO OUR NORTHWEST...IT APPEARS THE DEFORMATION BAND WILL REMAIN
WEST OF US AND THE EASTERLY FLOW PATTERN WILL CONTINUE THROUGH THE
NIGHT. THE STRONG SURFACE HIGH OVER THE NORTHERN PLAINS AND COLD
AIR/NORTHERLY FLOW ON THE NORTHEAST COLORADO PLAINS WILL ALSO
HELP MAINTAIN THE EASTERLY FLOW SETUP. HAVE BUMPED UP THE WIND
SPEED FORECASTS IN THE MOUNTAIN AREAS THROUGH THE OVERNIGHT HOURS.
OTHER ELEMENTS OF THE FORECAST HAVE BEEN ADJUSTED SLIGHTLY AS
DETAILED BELOW.
&&
.AVIATION...DRY AIR AT LOW AND MID LEVELS IS GOING TO COMBINE WITH
THE MAIN DEFORMATION BANDS REMAINING WEST OF US TO KEEP THE DENVER
AREA AIRPORTS DRY OVERNIGHT. LIGHT NORTHERLY WINDS AT THE PRESENT
TIME ARE GOING TO BE FIGHTING AGAINST A TENDENCY FOR THE WINDS TO
RETURN TO DRAINAGE. WILL PROBABLY SEE A WIND SHIFT TO SOUTHERLY
AFTER 06Z. NO OTHER AVIATION IMPACTS EXPECTED THROUGH TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 707 PM MST FRI NOV 22 2013/
SHORT TERM...TONIGHT AND SATURDAY...
THE UPPER LOW SPINS IN PLACE THIS EVENING SOMEWHERE NEAR SAN
DIEGO. SATELLITE LOOPS SHOW A DEFINED DEFORMATION ZONE ACOSS
UTAH INTO NORTHWEST COLORADO...AND AN APPARENT DRY SLOT INTO
SOUTH CENTRAL COLORADO. INTERESTINGLY THE 00Z SOUNDING SHOWED
A PRONOUNCED DRY SLOT CENTERED AROUND 700 MB...ONE REASON SNOW
HAS HAD A HARD TIME ADVANCING NORTHWARD AS SEEN ON RADAR LOOPS.
FOR TONIGHT RUC SHOWS A BIT OF SNOW ON THE PALMER...AND WESTERN
AND SOUTHERN SUBURBS OF DENVER WITH UP TO 4 INCHES IN PARK COUNTY
AND THE CENTRAL MOUNTAINS..WITH LITTLE SNOW NORTH OF I70. GRIDS
SHOW THIS TREND...WE DID GET ONE REPORT OF TOUGH TRAVEL
CONDITIONS IN SNOW AND BLOWING SNOW ON LOVELAND PASS...
WILL RAISE SNOW AMOUNTS A BIT IN THE HIGH COUNTRY...AND WITH
CLOUD COVER THE MINS MAY BE A BIT TOO LOW IN THE METRO AREA...BUT
TEMPS ARE TRICKY...WITH ONE HOUR OF CLEARING TEMPS COULD DROP INTO
THE TEENS. WILL EDGE UPWARD.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY...UPPER LEVEL LOW WILL
CONTINUE TO SLOWLY MOVE EAST ACROSS ARIZONA AND NEW MEXICO SATURDAY
NIGHT THROUGH MONDAY. A DEFORMATION ZONE OVER COLORADO WILL KEEP
SNOW GOING OVER SOUTHERN COLORADO...MEANWHILE NORTHERN COLORADO WILL
REMAIN ON THE DRY SIDE OF THE DEFORMATION ZONE. HIGHS CLOUDS WILL
WILL CONTINUE TO SPREAD OVER NORTHERN COLORADO HELPING TO KEEP
TEMPERATURES COOL SUNDAY. BEST CHANCE FOR SNOW WILL BE SOUTH OF
INTERSTATE 70...MAINLY OVER PARK AND LINCOLN COUNTIES.
UPPER LEVEL RIDGE WILL BUILD OVER THE GREAT BASIN AND CENTRAL
ROCKIES TUESDAY THROUGH THURSDAY. THIS WILL KEEP DRY CONDITIONS OVER
COLORADO. AIRMASS WILL WARM WITH HIGHS NEAR NORMAL TO SLIGHTLY ABOVE
NORMAL WITH READINGS IN THE UPPER 40S TO MID 50S.
THE NEXT STORM SYSTEM IS FORECASTED TO DIG SOUTH ALONG THE
CALIFORNIA COAST LATE NEXT WEEK. THIS WILL CAUSE FLOW ALOFT TO
BECOME SOUTHWESTERLY. MILD TEMPERATURES AND DRY CONDITIONS ARE
EXPECTED NEXT FRIDAY AND LIKELY INTO NEXT WEEKEND.
AVIATION...LOOKS LIKE SNOW WILL STAY AWAY FROM DIA...WITH A
SLIGHT CHANCE OF SNOW SHOWERS AT APA AND BJC...BUT NOT EXPECTING
REDUCTION TO VISIBILITIES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM....99
AVIATION...RTG
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
707 PM MST FRI NOV 22 2013
.SHORT TERM...TONIGHT AND SATURDAY...
THE UPPER LOW SPINS IN PLACE THIS EVENING SOMEWHERE NEAR SAN
DIEGO. SATELLITE LOOPS SHOW A DEFINED DEFORMATION ZONE ACOSS
UTAH INTO NORTHWEST COLORADO...AND AN APPARENT DRY SLOT INTO
SOUTH CENTRAL COLORADO. INTERESTINGLY THE 00Z SOUNDING SHOWED
A PRONOUNCED DRY SLOT CENTERED AROUND 700 MB...ONE REASON SNOW
HAS HAD A HARD TIME ADVANCING NORTHWARD AS SEEN ON RADAR LOOPS.
FOR TONIGHT RUC SHOWS A BIT OF SNOW ON THE PALMER...AND WESTERN
AND SOUTHERN SUBURBS OF DENVER WITH UP TO 4 INCHES IN PARK COUNTY
AND THE CENTRAL MOUNTAINS..WITH LITTLE SNOW NORTH OF I70. GRIDS
SHOW THIS TREND...WE DID GET ONE REPORT OF TOUGH TRAVEL
CONDITIONS IN SNOW AND BLOWING SNOW ON LOVELAND PASS...
WILL RAISE SNOW AMOUNTS A BIT IN THE HIGH COUNTRY...AND WITH
CLOUD COVER THE MINS MAY BE A BIT TOO LOW IN THE METRO AREA...BUT
TEMPS ARE TRICKY...WITH ONE HOUR OF CLEARING TEMPS COULD DROP INTO
THE TEENS. WILL EDGE UPWARD.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY...UPPER LEVEL LOW WILL
CONTINUE TO SLOWLY MOVE EAST ACROSS ARIZONA AND NEW MEXICO SATURDAY
NIGHT THROUGH MONDAY. A DEFORMATION ZONE OVER COLORADO WILL KEEP
SNOW GOING OVER SOUTHERN COLORADO...MEANWHILE NORTHERN COLORADO WILL
REMAIN ON THE DRY SIDE OF THE DEFORMATION ZONE. HIGHS CLOUDS WILL
WILL CONTINUE TO SPREAD OVER NORTHERN COLORADO HELPING TO KEEP
TEMPERATURES COOL SUNDAY. BEST CHANCE FOR SNOW WILL BE SOUTH OF
INTERSTATE 70...MAINLY OVER PARK AND LINCOLN COUNTIES.
UPPER LEVEL RIDGE WILL BUILD OVER THE GREAT BASIN AND CENTRAL
ROCKIES TUESDAY THROUGH THURSDAY. THIS WILL KEEP DRY CONDITIONS OVER
COLORADO. AIRMASS WILL WARM WITH HIGHS NEAR NORMAL TO SLIGHTLY ABOVE
NORMAL WITH READINGS IN THE UPPER 40S TO MID 50S.
THE NEXT STORM SYSTEM IS FORECASTED TO DIG SOUTH ALONG THE
CALIFORNIA COAST LATE NEXT WEEK. THIS WILL CAUSE FLOW ALOFT TO
BECOME SOUTHWESTERLY. MILD TEMPERATURES AND DRY CONDITIONS ARE
EXPECTED NEXT FRIDAY AND LIKELY INTO NEXT WEEKEND.
&&
.AVIATION...LOOKS LIKE SNOW WILL STAY AWAY FROM DIA...WITH A
SLIGHT CHANCE OF SNOW SHOWERS AT APA AND BJC...BUT NOT EXPECTING
REDUCTION TO VISIBILITIES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RTG
LONG TERM....MEIER
AVIATION...RTG
AREA FORECAST DISCUSSION
NWS PUEBLO CO
315 PM MST THU NOV 21 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 248 PM MST THU NOV 21 2013
...SNOW BAND TO BRING LOCALLY HEAVY SNOW AMOUNTS TO PART OF SOUTHERN
COLORADO...
CURRENTLY...
ARCTIC AIRMASS HAS MOVED ACROSS THE PLAINS...WITH TEMPS IN THE 20S
PLAINS AND OVC SKIES. COLD AIR HAS NOT MADE IT OVER THE MTNS YET AND
THE SLV STILL HAD TEMPS AOA 50F.
A WELL DEFINED JET STREAK WAS NOTED RAGING ACROSS S CALIF INTO THE 4
CORNERS.
REST OF TODAY THROUGH TOMORROW...
SIMULATIONS CONTINUE TO INDICATE A SNOW BAND CAPABLE OF LOCALLY
HEAVY SNOW WILL SET UP OVER SOUTHERN COLORADO LATER THIS EVENING
INTO TOMORROW. THE GUIDANCE HAS BEEN VERY CONSISTENT WITH THIS BAND
OVER THE LAST SEVERAL DAYS. LATEST 18Z NAM CONTINUES TO SHOW THIS
PATTERN AND THE HRRR SUPPORTS THE DEVELOPMENT OF THIS BAND. THIS
BAND IS ASSOCIATED WITH A BAROCLINIC ZONE IN THE 600-7000MB LAYER
THAT IS PROGGED NOT TOO MOVE TOO MUCH. IT APPEARS AT THIS TIME THE
BEST CHANCE OF HEAVIER SNOW WILL FALL GENERALLY ALONG AND SOUTH OF
US HIGHWAY 50.
SNOWFALL AMOUNTS WITH THIS BAND FOR TONIGHT THROUGH TOMORROW
ACCORDING TO GUIDANCE ARE RATHER IMPRESSIVE..AND HAVE CUT BACK FROM
GUIDANCE...STILL 4-7" AMOUNTS WILL BE POSSIBLE OVER NEARLY ALL OF
THE SAN LUIS VALLEY AND MOST OF THE PLAINS GENERALLY SOUTH OF
HIGHWAY 50 AND WEST OF SPRINGFIELD.
THE SANGRES...WETS AND SAN JUANS SHOULD DO VERY WELL WITH THIS
EVENT...WITH 12-18" OVER THE SAN JUANS AND NEAR A FOOT OVER THE
SANGRES AND WETS.
FARTHER NORTH LESS SNOW IS LIKELY AND HAVE CUT BACK ON AMOUNTS IN
THE CENTRAL MOUNTAINS. HAVE ALSO DOWNGRADED WARNINGS TO ADVISORIES
FOR PARTS OF THE CENTRAL MOUNTAIN REGION.
THE PIKES PEAK REGION WILL SEE ON AND OF SNOW SHOWERS WITH 1-3"
POSSIBLE THROUGH THE PERIOD. THE BEST CHANCE OF SNOW MAY OCCUR LATER
TOMORROW AS THE BAND LIFTS A BIT TO THE NORTH. HOWEVER THE SNOW IS
EXPECTED TO BE DECREASING AS THE FRONTOGENETICAL FORCING LESSENS
WITH TIME.
TOMORROW WILL BE ANOTHER COLD DAY WITH HIGHS ON THE 20S ALL AREAS.
WE MAY SEE SOME BREAKS IN THE CLOUDS LATE IN THE DAY OVER THE
NORTHERN PARTS OF THE CWA. /HODANISH
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 248 PM MST THU NOV 21 2013
...SNOW AND COLD CONTINUES...
FRIDAY NIGHT-SATURDAY...SNOW ACROSS THE EASTERN PLAINS WILL SLOWLY
WIND DOWN BETWEEN 06Z-09Z EARLY SATURDAY MORNING ACROSS THE EASTERN
PLAINS AS THE BEST LIFT MOVES AWAY FROM THE AREA.
ATTENTION THEN TURNS TO THE CUT OFF LOW SPINNING OVER SOUTHERN
CALIFORNIA. THE GFS AND THE NAM ARE IN SOMEWHAT BETTER AGREEMENT
WITH THE EC MODELS HANDLING OF THE LOW AND AM NOW MORE CONFIDENT THE
LOW WILL TAKE A MORE NORTHERLY TRACK THEN PREVIOUS GFS FORECASTS
HAVE SHOWN. IN COORDINATION WITH DDC/GLD/GJT I HAVE INCREASED POPS
ACROSS ALL OF THE MOUNTAIN AREAS SATURDAY AND SUNDAY...AND ACROSS
THE PLAINS ON SUNDAY. IF CURRENT MODEL TRENDS CONTINUE...I AM FAIRLY
CERTAIN THE WINTER STORM WARNING FOR THE SAN JUANS WILL NEED TO BE
EXTENDED THROUGH AT LEAST SATURDAY EVENING. THE 18Z NAM12 SHOWS 30
INCHES OF SNOWFALL BETWEEN 00Z SATURDAY AND 12Z SUNDAY ACROSS THE
SAN JUANS. THE 12Z GFS PAINTS 20 INCHES DURING THE SAME TIME FRAME.
TOO EARLY TO EXTEND THE WARNING AT THIS TIME.
SUNDAY...AS SNOW CHANCES REMAIN HIGH ALONG THE CONTINENTAL
DIVIDE...MODELS DIFFER ON HOW MUCH SNOW WILL FALL ACROSS THE EASTERN
MOUNTAINS AND THE PLAINS ON SUNDAY. THE GFS/NAM12 SHOW A
VORT MAX ROTATING AROUND THE CUTOFF LOW BETWEEN 09Z-12Z SUNDAY
MORNING...AND PUSHING IT THROUGH THE EASTERN PLAINS. THE GFS IS MUCH
WEAKER WITH THIS FEATURE AND SHOWS NO MORE THEN A DUSTING OF SNOW
ACROSS THE PLAINS...3 TO 6 INCHES IN THE WET MOUNTAINS AND THE
SANGRES THROUGH 00Z MONDAY. THE NAM SHOWS ALMOST A FOOT OF SNOW
ACROSS THE SAME MOUNTAIN ZONES AND UP TO 3 INCHES ALONG THE HIGHWAY
50 CORRIDOR EAST OF PUB (LAA/LHX). I HAVE TAKEN THE MORE
CONSERVATIVE GFS ROUTE AT THIS TIME...INCREASING POPS AND SNOW
AMOUNTS SLIGHTLY. HIGHLIGHT CRITERIA MAY BE REACHED IN THE
SANGRES/WETS IF THE NAM SOLUTION VERIFIES.
MONDAY-THURSDAY...MODELS DRY OUT THE FORECAST AREA RATHER QUICKLY
MONDAY...WITH ONLY A FEW REMAINING SNOW SHOWERS MONDAY MORNING. WEST
AND NORTHWEST FLOW WILL KEEP THE AREA DRY THROUGHOUT THE PERIOD.
500MB AND 700MB WINDS TURN MORE WEST AND SOUTHWEST LATE WEDNESDAY
THROUGH THURSDAY AHEAD OF ANOTHER PACIFIC STORM SYSTEM. TEMPERATURES
WILL REBOUND BACK TO AVERAGE LEVELS AS WELL. -PJC
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 248 PM MST THU NOV 21 2013
A SNOW BAND WILL DEVELOP OVER SOUTHERN COLORADO LATER THIS AFTERNOON
AND LAST INTO TOMORROW. THE HEAVIEST SNOW WILL FALL GENERALLY ALONG
AND SOUTH OF HIGHWAY 50. KALS WILL BE IMPACTED WITH SIGNIFICANT
ACCUMULATING SNOW LIKELY...WITH UP TO 6" POSSIBLE. SNOW WILL BEGIN
AT KALS THIS EVENING...~03Z...AND LAST INTO TOMORROW.
KPUB WILL BE ON THE NORTHERN GRADIENT BUT STILL EXPECT 1-3" OF
ACCUMULATING SNOW TONIGHT INTO TOMORROW.
KCOS WILL SEE MUCH SNOW...BUT LOW CIGS WILL LIKELY LAST THROUGH
TOMORROW. THE BEST CHANCE FORM SOME ACCUMULATING SNOW MAY ACTUALLY
BE TOMORROW AFTERNOON AS THE BAND LIFTS A BIT TO THE NORTH.
GIVEN THE CURRENT GUIDANCE...ALL AIRPORTS...KCOS...KALS AND KPUB
WILL SEE IFR CONDITIONS FORM MOST IF NOT ALL OF THE NEXT 24H.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 6 PM MST
FRIDAY FOR COZ062-063-076>078-083-086-089-093-097>099.
WINTER WEATHER ADVISORY UNTIL 6 PM MST FRIDAY FOR COZ058-059-061-
064.
WINTER STORM WARNING FROM 11 PM THIS EVENING TO 6 PM MST FRIDAY
FOR COZ069>075-079-080-087-088-094.
WINTER STORM WARNING UNTIL 6 PM MST FRIDAY FOR COZ060-065>068.
&&
$$
SHORT TERM...HODANISH
LONG TERM...PJC
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1239 PM MST THU NOV 21 2013
.UPDATE...
ISSUED AT 1238 PM MST THU NOV 21 2013
SHALLOW COLD FRONT HAS SLIPPED TO THE NORTH SIDE OF THE
ROAN/TAVAPUTS PLATEAUS BY MIDDAY...SETTING UP FOR SOME OVERRUNNING
PRECIPITATION THERE WITH MOIST SOUTHERLY FLOW ALOFT. VALLEY TEMPS
WERE GENERALLY IN THE 20S TO AROUND 30 ACROSS NW CO AND NEAR
FREEZING IN VERNAL...AND DON/T EXPECT MUCH WARMING UNDER THE
CLOUDS. ROADS WERE GENERALLY WET FROM FROM WEBCAMS AND SPOTTER
REPORTS WITH SOME ACCUMULATING ON THE GRASS...BUT THINK ROADS WILL
BEGIN COLLECTING SNOW HEADING INTO EVENING. THUS...HAVE ISSUED A
WINTER WEATHER ADVISORY UNTIL 9 PM FOR THE NW CO VALLEYS
EXCLUDING STEAMBOAT WITH 2-4 INCHES EXPECTED GENERALLY SOUTH OF
HWY 4O. ALSO EXTENDED THE ADVISORY FOR THE EASTERN UINTAS AND
FLATTOPS...AND ADDED ZONE 4 TO THE ADVISORY BASED ON SPOTTER
REPORTS OF 6-8 INCHES AROUND HAHNS PEAK AND STEAMBOAT LAKES.
CLOUDS CONTINUE TO INDICATE A CONVECTIVE NATURE ON VISIBLE
SATELLITE IMAGES ACROSS SE UT/SW CO FOR A SHIFT TO MORE SHOWERY
PRECIPITATION...WITH SOME BREAKS IN THE CLOUD COVER. WITH THE
LIGHTNING POTENTIAL INDEX SHOWING SOME THREAT OF
THUNDERSTORMS AND THE AREA BEING IN SPC DAY 1 CONVECTIVE OUTLOOK...
HAVE ADDED ISOLATED THUNDERSTORMS THIS AFTERNOON TO SE UT AND SW CO.
UPDATE ISSUED AT 843 AM MST THU NOV 21 2013
A COLD FRONT WAS SLIPPING SOUTH ACROSS NE UT/NW CO THIS MORNING
AND APPEARS TO HAVE PUSHED TO ROUGHLY A MEEKER TO PRICE LINE.
PRECIPITATION WAS IN THE FORM OF SNOW AT CRAIG...MEEKER...AND JUST
CHANGED TO SNOW AT VERNAL. SURFACE AIR NEAR SATURATION IN MANY
PLACES FOR AREAS OF FOG AS WELL. 14Z RUC SHOWED THE FRONT STALLING
AROUND THE I-70 CORRIDOR OR A LITTLE SOUTH THIS AFTERNOON...WITH
HI-RESOLUTION HRRR MODEL INDICATING SOME OVERRUNNING PRECIPITATION
ACROSS NE UT/NW CO INTO THE AFTERNOON. WILL HAVE TO WATCH THIS
AREA FOR SNOW ACCUMULATION BUT FOR NOW ANTICIPATE THE TEMPS WILL
BE WARM ENOUGH TO PREVENT HIGHLIGHT CRITERIA SNOW ACCUMS THERE
TODAY. CLOUDS HAVE A CONVECTIVE NATURE ON VISIBLE SATELLITE IMAGES
THIS MORNING ACROSS SE UT/SW CO FOR A SHIFT TO MORE SHOWERY
PRECIPITATION AT LEAST IN THE SOUTHERN VALLEYS DURING THE MORNING.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 348 AM MST THU NOV 21 2013
DEEP MOISTURE CONTINUES TO LINGER OVER THE REGION FROM THE PAST
FEW DAYS OF ATMOSPHERIC SATURATION. 300K/305K MOISTURE TRANSPORT
VECTORS SHOW A STEADY STREAM OF ZONAL MOISTURE FROM ABOUT THE FOUR
CORNERS SOUTH...BUT THAT IS NOT STOPPING MOST OF WESTERN CO AND
EASTERN UT FROM CONTINUING TO PRECIPITATE EARLY THIS MORNING. IR
SATELLITE AND RADAR SHOW INDICATE SHOWERS WITH LOW CLOUD TOPS
MOVING NORTHEAST AND BEGINNING TO BREAK UP...BUT NEARLY EVERY WX
STATION IN THE CWA IS REPORTING LIGHT PRECIPITATION AND/OR FOG.
A CLOSED UPPER LEVEL LOW CURRENTLY OVER NORTHERN CA AND NEVADA IS
SLOWLY MAKING ITS WAY EASTWARD...AND AS IT DOES...A LONG FETCH OF
SOUTHWEST FLOW WILL PROVIDE STRONG ISENTROPIC UPLIFT OVER AN
ALREADY COOL AIRMASS. SIGNIFICANT SNOWFALL IS EXPECTED AT ALL
SOUTHERN CO/UT MOUNTAIN LOCATIONS.
ANOTHER MAJOR FACTOR IN TODAY/S WEATHER IS STRONG FRONTOGENESIS
WHICH WILL BE OVER NORTHERN UT AND CO AROUND NOON TODAY MAKING
IT/S WAY SOUTH TO THE FOUR CORNERS BY THURSDAY NIGHT. THIS
STRENGTHENING FRONTAL PASSAGE WILL LOWER SNOW LEVELS FROM NORTH TO
SOUTH TODAY BEFORE ERODING INTO THE LARGER TROUGH FUELED BY THE
CLOSED LOW OVER NEVADA. EXPECTING COLD ADVECTIVE-INDUCED SNOW
SHOWERS NORTH OF THE FRONT. SOUTHWEST FLOW WILL STRENGTHEN BY
THURSDAY NIGHT AND TRANSPORT A SLUG OF MOISTURE BACK INTO THE
REGION OVER A DEFORMATION ZONE LEFTOVER BY THE COLD FRONT FROM
THURSDAY AFTERNOON. WITH SUCH A SATURATED ENVIRONMENT ALREADY AND
A STRONG DEFORMATION ZONE...IT WILL NOT TAKE MUCH TO PRODUCE A LOT
OF PRECIPITATION WITHIN A MATTER OF HOURS OVERNIGHT AND FRIDAY
MORNING.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 AM MST THU NOV 21 2013
MODELS SHOW THE UPPER LEVEL LOW MOVING VERY SLOWLY WITH PIECES OF
ENERGY KEEPING CLOUD COVER AND PRECIPITATION IN THE PICTURE
THROUGH THE EARLY PART OF THE WEEKEND. NORTHERN UT/CO ARE NOT LIKELY TO
SEE MUCH IN THE WAY OF PRECIPITATION BY THE TIME FRIDAY NIGHT
ROLLS AROUND.
SATURDAY THROUGH WEDNESDAY...FOR THE MOST PART THE MID-RANGE
MODELS ARE IN MUCH BETTER AGREEMENT IN TIMING THE SW U.S. AS IT
MOVES FROM BAJA CALIFORNIA INTO NM SAT THROUGH MON. ON SAT THE
LOW CENTER SHOULD BE OVER SOUTHERN CA WITH ITS COLD FRONT
ORIENTATED N TO S OVER CENTRAL AND EASTERN AZ. THROUGHOUT SAT A
FOUNTAIN OF STRONG MOIST SOUTHERLY FLOW FEEDING INTO STRONG UPPER
DIVERGENCE WILL MOVE OVER SE UT AND SRN CO...ALL SPREADING OUT
INTO A DEFORMATION ZONE OVER CENTRAL AND NORTHERN CO AND UT. THIS
SETUP SHOULD CONTINUE WIDESPREAD PCPN OVER THE SOUTHERN TWO THIRDS
OF THE FORECAST AREA AND HAVE INCREASED CLOUD COVER AND POPS TO
REFLECT THIS.
THE GFS AND ECMWF BOTH PLACE THE CLOSED LOW OVER CENTRAL AZ AT
18Z ON SUNDAY AND PUSH THE COLD FRONT EAST OF THE AREA ALONG WITH
THE BEST UPWARD MOTION. ABOUT THIS TIME MOISTURE IS PROJECTED TO
BEGIN WRAPPING AROUND THE NORTH SIDE OF THE LOW...THOUGH THERE
ISN`T A STRONG TROWAL SIGNATURE IN THE TEMP FIELDS. STILL...THE
MOISTURE IN THE E AND NE FLOW TO THE NORTH OF THE LOW CENTER
SHOULD KEEP CLOUDS AND PCPN OVER THE SOUTHERN PART OF THE FORECAST
AREA UNTIL MONDAY MORNING.
TUESDAY AND WEDNESDAY...A RIDGE WILL BUILD OVER THE WESTERN U.S.
AND BRING A WARMING AND DRYING TREND OF CO AND UT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT
1226 PM MST THU NOV 21 2013
WIDESPREAD LOW CLOUDS AND PRECIPITATION OVER THE NEXT 24 HOURS WILL
PRODUCE PERIODS OF MVFR AND IFR CONDITIONS AT THE MOUNTAIN AND
HIGH VALLEY TAF SITES AND AIRPORTS. MOST MOUNTAINS AND HIGH
MOUNTAIN PASSES WILL BE OBSCURED BY CLOUDS AND SNOWFALL. OTHER TAF
SITES AND AIRPORTS WILL SEE PERIODS OF MVFR CIGS AND VSBYS FROM
RAIN OR SNOW.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 9 PM MST THIS EVENING FOR
COZ001>003.
WINTER STORM WARNING UNTIL 6 PM MST SATURDAY FOR COZ018-019.
WINTER STORM WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING
FOR COZ014.
WINTER STORM WARNING UNTIL MIDNIGHT MST FRIDAY NIGHT FOR COZ009-
010-012-017.
WINTER WEATHER ADVISORY UNTIL 6 AM MST FRIDAY FOR COZ004-013.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM MST SATURDAY
FOR COZ022-023.
UT...WINTER WEATHER ADVISORY UNTIL 9 PM MST THIS EVENING FOR UTZ023-
025.
WINTER STORM WARNING UNTIL 6 PM MST SATURDAY FOR UTZ028.
&&
$$
UPDATE...JAD
SHORT TERM...JAM
LONG TERM...JAM/CC
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1013 AM MST THU NOV 21 2013
.UPDATE...
&&
.SHORT TERM...MAIN BATCH OF LIFT HAS MOVED ONTO THE FAR EASTERN
PLAINS...RADAR IS INDICATING THE WIDESPREAD LIGHT TO MODERATE
SNOW IS CURRENTLY LOCATED THERE. STILL SOME LIGHT SNOW ALONG THE
FOOTHILLS AND URBAN CORRIDOR. FROM WEB CAMS...IT LOOKS LIKE ONLY
SCATTERED AREAS OF LIGHT SNOW ACROSS THE MOUNTAINS. STILL
EXPECTED OCCASIONAL LIGHT SNOW TO CONTINUE THROUGH THE
AFTERNOON...AS THERE WILL STILL BE WEAK LIFT ACROSS THE AREA WITH
THE MAIN LOW STILL SOUTHWEST OF COLORADO. LATEST MODELS INDICATING
ANY ADDITIONAL SNOW ACCUMULATION TO BE 3 INCHES OR LESS THROUGH
THE AFTERNOON...WITH THE HIGHEST AMOUNTS FAR EASTERN PLAINS. WITH
COLD AIRMASS IN PLACE...SHOULDN`T TAKE MUCH FOR SNOW TO BE
GENERATED WITH THE WEAK LIFT. WITH ONLY LIGHT SNOW EXPECTED...WILL
LET THE ADVISORY FOR THE FOOTHILLS AND URBAN CORRIDOR EXPIRE AT
NOON AND KEEP THE ADVISORY FOR THE REST OF THE PLAINS GOING FOR
THE AFTERNOON WHERE THERE IS BETTER LIFT. LATEST RAP IS HINTING AT
AN INCREASE IN MID LEVEL QG ASCENT LATER THIS AFTERNOON AND EARLY
EVENING WHICH COULD INCREASE THE SNOW. FOR NOW WILL LEAVE THE
CURRENT POPS GOING AND WILL ADDRESS THIS LATER.
.AVIATION...MAIN BATCH OF SNOW HAS MOVED EAST ONTO THE PLAINS.
STILL LIGHT SNOW ONGOING ACROSS THE DENVER AREA...WITH AN AREA OF
MODERATE SNOW MOVING EAST ACROSS WESTERN ADAMS COUNTY INTO THE
DENVER AREA. STILL EXPECTING MFR CONDITIONS TO PREVAIL THROUGH THE
AFTERNOON WITH AREAS OF IFR CONDITIONS. IMPROVEMENT STILL EXPECTED
BY MIDNIGHT. OVERALL CURRENT TAF TRENDS SEEM REASONABLE.
ADDITIONAL ACCUMULATIONS OF AROUND AN INCH.
&&
.PREV DISCUSSION... /ISSUED 326 AM MST THU NOV 21 2013/
SHORT TERM...IT APPEARS THAT THE STRONGEST WINDS...GREATEST
TEMPERATURE GRADIENT...AND STRONGEST LIFT ASSOCIATED WITH THE
OVERNIGHT COLD FRONT HAVE PASSED OUR AREA. COLD ADVECTION ON NORTH
WINDS WILL CONTINUE TODAY WITH TEMPERATURES ON THE PLAINS STEADY
OR FALLING AND LITTLE TEMPERATURE RISE IN THE MOUNTAINS. THERE
STILL APPEARS TO BE WIDESPREAD LIGHT SNOW IN THE COLD AIR. MAIN
CHANGE FROM LAST NIGHTS FORECAST IS TO ACCOUNT FOR THE SECONDARY
AREA OF WEAK LIFT EVIDENT ON THE SATELLITE PICTURES AND RADARS NOW
OVER NORTHWESTERN COLORADO. WHILE THE OROGRAPHIC ENHANCEMENT ON
THE PALMER DIVIDE SHOULD FADE THIS MORNING...THIS AREA OF LIFT
WILL MOVE OVER THE COLD AIR COVERING NORTHEASTERN COLORADO. SO THE
FOCUS SHOULD SHIFT FROM THE SOUTHERN PART OF OUR AREA BACK TOWARD
THE NORTH THIS MORNING...THEN WE SHOULD SEE A FURTHER DECREASE IN
THE SNOW THIS AFTERNOON BUT THERE COULD STILL BE SOME WEAK LIFT
OVER THE NORTHERN BORDER AREAS. THE NEXT BATCH OF LIFT STILL
EXPECTED TO GO FURTHER SOUTH...MAINLY SOUTH OF OUR AREA...BUT THIS
WILL NEED TO BE WATCHED AS WELL AS IT WILL NOT TAKE MUCH TO
GENERATE MORE LIGHT SNOW. THIS THREAT SEEMS TO BE DEALT WITH
ADEQUATELY AT THIS TIME...BUT WE MAY NEED HIGHER POPS FURTHER
NORTH TONIGHT.
SNOWFALL SHOULD REMAIN LIGHT FOR THE MOST PART...PERHAPS NOT UP TO
THE USUAL ADVISORY CRITERIA IN MOST PLACES. HOWEVER THE ROADS GOT
WETTED DOWN PRETTY WELL LAST NIGHT AND TEMPERATURES WILL BE IN THE
TEENS THIS MORNING...SO IT SEEMS THERE IS A PRETTY SUBSTANTIAL
THREAT OF ICY ROADS. I WILL HANG ON TO THE ADVISORIES WE HAVE AND
ADD AN ADVISORY THROUGH 4 PM FOR NORTHEASTERN COLORADO WHERE THE
MOST SNOW MAY BE DURING THE DAY.
LONG TERM...AN UPPER LEVEL LOW WILL REMAIN CUT OFF OVER NEAR
BAJA CALIFORNIA ON FRI WITH WSW FLOW ALOFT. MEANWHILE COLD HIGH
PRES AT THE SFC WILL REMAIN OVER ERN CO. CROSS-SECTIONS SHOW
ABUNDANT MOISTURE ACROSS THE MTNS HOWEVER LAPSE RATES ARE POOR AND
THERE IS NO MID LVL ASCENT. AT THIS TIME IT LOOKS LIKE THE BEST
CHC OF SNOW IN THE MTNS WILL BE SOUTH OF I-70 WITH ONLY LIGHT
ACCUMULATIONS. OVER NERN CO THERE IS NO UPSLOPE COMPONENT AS A
SHALLOW LYR OF COLD AIR WILL REMAIN OVER THE AREA SO WILL KEEP
HIGHS IN THE UPPER 20S TO LOWER 30S. THERE COULD BE SOME LINGERING
LIGHT SNOW OVER THE SRN FOOTHILLS AND OVER THE PALMER DIVIDE SO
WILL KEEP IN SOME LOW POPS IN THESE AREAS.
BY SAT THE UPPER LEVEL LOW WILL BE OVER SRN CALIFORNIA WITH QUITE A
BIT OF MID AND HIGH LEVEL MOISTURE IN SWLY FLOW ALOFT MOVING ACROSS
THE AREA. ONCE AGAIN COULD SEE A CHC OF SNOW SHOWERS IN THE MTNS
THRU THE DAY HOWEVER WITH POOR LAPSE RATES AMOUNTS SHOULD BE LIGHT.
MEANWHILE ANOTHER SURGE OF COLD AIR IS FCST TO MOVE SE ACROSS THE
NRN AND CNTRL PLAINS ON SAT WITH SOME OF THIS AIR POSSIBLY AFFECTING
NERN CO. AS A RESULT 850-700 MB TEMPS DO NOT CHANGE MUCH ON SAT SO
WILL KEEP READINGS IN THE 30S.
FOR SUN THE UPPER LEVEL LOW OVER THE SWRN US WILL BEGIN TO MOVE ENE
THRU SUN NIGHT. THE GFS KEEPS THE BULK OF THIS SYSTEM OVER THE SRN
ROCKIES WITH MOST OF THE MOISTURE AND PCPN STAYING OVER SRN CO.
MEANWHILE THE ECMWF AND GEM SHOW A SIGNIFICANT PIECE OF ENERGY
MOVING NE INTO ERN CO BY SUN EVENING WITH PCPN THREAT MUCH FURTHER
NORTH AFFECTING THE NERN PLAINS. AT THIS TIME WILL MENTIONS SOME
LOW POPS MAINLY OVER SRN AREAS OF THE CWA FOR SUN AFTN AND NIGHT.
IN THE MTNS LOOKS LIKE THE BEST CHC OF SNOW WILL BE MAINLY SOUTH OF
I-70. AS FOR HIGHS WILL WRM HIGHS BACK INTO THE LOWER TO MID 40S
OVER NERN CO ALTHOUGH THE FAR ERN PLAINS COULD STAY IN THE 30S
DEPENDING ON CLOUD COVER.
BY MON THE UPPER LEVEL LOW IS FCST TO MOVE MORE ESE WITH DRIER AIR
MOVING INTO NRN CO. THUS THIS WOULD END PCPN CHANCES AND ALLOW FOR
WARMER TEMPS WITH READINGS IN THE 45 TO 50 DEGREE RANGE OVER NERN
CO. FOR TUE A FLAT UPPER LEVEL RIDGE WILL BE OVER NRN CO WITH DRY
CONDITIONS. TEMPS SHOULD CONTINUE TO MODERATE WITH READINGS NEAR
SEASONAL LEVELS. ON WED THE FLAT UPPER LEVEL RIDGE IS FCST TO
CONTINUE WITH LITTLE CHC FOR PCPN. MEANWHILE ANOTHER COLD FNT MAY
MOVE INTO NERN CO DURING THE DAY BRINGING COOLER TEMPS.
AVIATION...LIGHT SNOW IS EXPECTED THROUGH THE MORNING WITH IFR
CONDITIONS PREVAILING. GRADUAL IMPROVEMENT WITH MVFR PREVAILING
THIS AFTERNOON AND EVENING...BUT STILL AREAS OF IFR. FURTHER
IMPROVEMENT IS POSSIBLE AFTER MIDNIGHT...AND LIKELY BY FRIDAY
MORNING. ADDITIONAL SNOWFALL AT THE DENVER AREA AIRPORTS WILL
LIKELY BE IN THE 1 TO 2 INCH RANGE...MAINLY THIS MORNING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR COZ042-
044-048>051.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ035-036-
038>041-043-045-046.
&&
$$
SHORT TERM...D-L
LONG TERM....RPK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
844 AM MST THU NOV 21 2013
.UPDATE...
ISSUED AT 843 AM MST THU NOV 21 2013
A COLD FRONT WAS SLIPPING SOUTH ACROSS NE UT/NW CO THIS MORNING
AND APPEARS TO HAVE PUSHED TO ROUGHLY A MEEKER TO PRICE LINE.
PRECIPITATION WAS IN THE FORM OF SNOW AT CRAIG...MEEKER...AND JUST
CHANGED TO SNOW AT VERNAL. SURFACE AIR NEAR SATURATION IN MANY
PLACES FOR AREAS OF FOG AS WELL. 14Z RUC SHOWED THE FRONT STALLING
AROUND THE I-70 CORRIDOR OR A LITTLE SOUTH THIS AFTERNOON...WITH
HI-RESOLUTION HRRR MODEL INDICATING SOME OVERRUNNING PRECIPITATION
ACROSS NE UT/NW CO INTO THE AFTERNOON. WILL HAVE TO WATCH THIS
AREA FOR SNOW ACCUMULATION BUT FOR NOW ANTICIPATE THE TEMPS WILL
BE WARM ENOUGH TO PREVENT HIGHLIGHT CRITERIA SNOW ACCUMS THERE
TODAY. CLOUDS HAVE A CONVECTIVE NATURE ON VISIBLE SATELLITE IMAGES
THIS MORNING ACROSS SE UT/SW CO FOR A SHIFT TO MORE SHOWERY
PRECIPITATION AT LEAST IN THE SOUTHERN VALLEYS DURING THE MORNING.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 348 AM MST THU NOV 21 2013
DEEP MOISTURE CONTINUES TO LINGER OVER THE REGION FROM THE PAST
FEW DAYS OF ATMOSPHERIC SATURATION. 300K/305K MOISTURE TRANSPORT
VECTORS SHOW A STEADY STREAM OF ZONAL MOISTURE FROM ABOUT THE FOUR
CORNERS SOUTH...BUT THAT IS NOT STOPPING MOST OF WESTERN CO AND
EASTERN UT FROM CONTINUING TO PRECIPITATE EARLY THIS MORNING. IR
SATELLITE AND RADAR SHOW INDICATE SHOWERS WITH LOW CLOUD TOPS
MOVING NORTHEAST AND BEGINNING TO BREAK UP...BUT NEARLY EVERY WX
STATION IN THE CWA IS REPORTING LIGHT PRECIPITATION AND/OR FOG.
A CLOSED UPPER LEVEL LOW CURRENTLY OVER NORTHERN CA AND NEVADA IS
SLOWLY MAKING ITS WAY EASTWARD...AND AS IT DOES...A LONG FETCH OF
SOUTHWEST FLOW WILL PROVIDE STRONG ISENTROPIC UPLIFT OVER AN
ALREADY COOL AIRMASS. SIGNIFICANT SNOWFALL IS EXPECTED AT ALL
SOUTHERN CO/UT MOUNTAIN LOCATIONS.
ANOTHER MAJOR FACTOR IN TODAY/S WEATHER IS STRONG FRONTOGENESIS
WHICH WILL BE OVER NORTHERN UT AND CO AROUND NOON TODAY MAKING
IT/S WAY SOUTH TO THE FOUR CORNERS BY THURSDAY NIGHT. THIS
STRENGTHENING FRONTAL PASSAGE WILL LOWER SNOW LEVELS FROM NORTH TO
SOUTH TODAY BEFORE ERODING INTO THE LARGER TROUGH FUELED BY THE
CLOSED LOW OVER NEVADA. EXPECTING COLD ADVECTIVE-INDUCED SNOW
SHOWERS NORTH OF THE FRONT. SOUTHWEST FLOW WILL STRENGTHEN BY
THURSDAY NIGHT AND TRANSPORT A SLUG OF MOISTURE BACK INTO THE
REGION OVER A DEFORMATION ZONE LEFTOVER BY THE COLD FRONT FROM
THURSDAY AFTERNOON. WITH SUCH A SATURATED ENVIRONMENT ALREADY AND
A STRONG DEFORMATION ZONE...IT WILL NOT TAKE MUCH TO PRODUCE A LOT
OF PRECIPITATION WITHIN A MATTER OF HOURS OVERNIGHT AND FRIDAY
MORNING.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 AM MST THU NOV 21 2013
MODELS SHOW THE UPPER LEVEL LOW MOVING VERY SLOWLY WITH PIECES OF
ENERGY KEEPING CLOUD COVER AND PRECIPITATION IN THE PICTURE
THROUGH THE EARLY PART OF THE WEEKEND. NORTHERN UT/CO ARE NOT LIKELY TO
SEE MUCH IN THE WAY OF PRECIPITATION BY THE TIME FRIDAY NIGHT
ROLLS AROUND.
SATURDAY THROUGH WEDNESDAY...FOR THE MOST PART THE MID-RANGE
MODELS ARE IN MUCH BETTER AGREEMENT IN TIMING THE SW U.S. AS IT
MOVES FROM BAJA CALIFORNIA INTO NM SAT THROUGH MON. ON SAT THE
LOW CENTER SHOULD BE OVER SOUTHERN CA WITH ITS COLD FRONT
ORIENTATED N TO S OVER CENTRAL AND EASTERN AZ. THROUGHOUT SAT A
FOUNTAIN OF STRONG MOIST SOUTHERLY FLOW FEEDING INTO STRONG UPPER
DIVERGENCE WILL MOVE OVER SE UT AND SRN CO...ALL SPREADING OUT
INTO A DEFORMATION ZONE OVER CENTRAL AND NORTHERN CO AND UT. THIS
SETUP SHOULD CONTINUE WIDESPREAD PCPN OVER THE SOUTHERN TWO THIRDS
OF THE FORECAST AREA AND HAVE INCREASED CLOUD COVER AND POPS TO
REFLECT THIS.
THE GFS AND ECMWF BOTH PLACE THE CLOSED LOW OVER CENTRAL AZ AT
18Z ON SUNDAY AND PUSH THE COLD FRONT EAST OF THE AREA ALONG WITH
THE BEST UPWARD MOTION. ABOUT THIS TIME MOISTURE IS PROJECTED TO
BEGIN WRAPPING AROUND THE NORTH SIDE OF THE LOW...THOUGH THERE
ISN`T A STRONG TROWAL SIGNATURE IN THE TEMP FIELDS. STILL...THE
MOISTURE IN THE E AND NE FLOW TO THE NORTH OF THE LOW CENTER
SHOULD KEEP CLOUDS AND PCPN OVER THE SOUTHERN PART OF THE FORECAST
AREA UNTIL MONDAY MORNING.
TUESDAY AND WEDNESDAY...A RIDGE WILL BUILD OVER THE WESTERN U.S.
AND BRING A WARMING AND DRYING TREND OF CO AND UT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 348 AM MST THU NOV 21 2013
WIDESPREAD LOW CLOUDS AND PRECIPITATION OVER THE NEXT 24 HOURS WILL
PRODUCE PERIODS OF MVFR AND IFR CONDITIONS AT THE MOUNTAIN AND
HIGH VALLEY TAF SITES AND AIRPORTS. MOST MOUNTAINS AND HIGH
MOUNTAIN PASSES WILL BE OBSCURED BY CLOUDS AND SNOWFALL. OTHER TAF
SITES AND AIRPORTS WILL SEE PERIODS OF MVFR CIGS AND VSBYS FROM
RAIN OR SNOW.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 6 PM MST SATURDAY FOR COZ018-019.
WINTER STORM WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING
FOR COZ014.
WINTER STORM WARNING UNTIL MIDNIGHT MST FRIDAY NIGHT FOR COZ009-
010-012-017.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM MST SATURDAY
FOR COZ022-023.
WINTER WEATHER ADVISORY UNTIL 9 PM MST THIS EVENING FOR COZ013.
UT...WINTER STORM WARNING UNTIL 6 PM MST SATURDAY FOR UTZ028.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR UTZ023.
&&
$$
UPDATE...JAD
SHORT TERM...JAM
LONG TERM...JAM/CC
AVIATION...CC
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
742 PM EST FRI NOV 22 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION THIS EVENING WITH A
SECONDARY STRONGER COLD FRONT DISSIPATING SOUTHEAST THROUGH OUR
AREA SATURDAY EVENING. STRONG HIGH PRESSURE FROM THE MIDWEST WILL
BUILD INTO THE MID-ATLANTIC REGION LATE SUNDAY THROUGH MONDAY. LOW
PRESSURE DEVELOPING OVER THE SOUTHEAST STATES WILL THEN AFFECT THE
AREA TUESDAY INTO EARLY THURSDAY. MORE HIGH PRESSURE FROM THE
UPPER MIDWEST IS EXPECTED LATER THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
730 PM EARLY ESTF UPDATE FOR THE 930 PM SLOT: A COLD FRONT CROSSING
THE APPALACHIANS AT 7 PM WILL CROSS OUR AREA BETWEEN APPROXIMATELY 9
PM (POCONOS) AND 1 AM TONIGHT (COAST) 6Z/23. SCATTERED TO NUMEROUS
LIGHT SHOWERS MOVING EASTWARD THROUGH THE AREA WILL END FROM WEST
TO EAST WITH THE SHARP INCREASE IN NORTHWEST WINDS TONIGHT AND THE
ASSOCIATED ARRIVAL OF MUCH DRIER AIR. THE NAM AND NOW THE RAP I
THINK HAVE BEEN MORE ACCURATE REGARDING THE EVOLUTION OF THIS
ENTIRE EVENT FROM YESTERDAYS CYCLES THROUGH THE 18Z/22 VERSION. IT
LOOKS LIKE THE FRONT IS GENERATING A DECENT BAND OF SHOWERS NOW
FROM MOUNT POCONOS SWWD AND THAT IS SUPPOSED TO MAXIMIZE IN
ISOLATED .1/HR MDT SHOWERS IN CENTRAL NJ BY 04Z. POPS HAVE BEEN
RECENTLY BOOSTED IN E CENTRAL PA THROUGH CENTRAL AND COASTAL NJ AS
WELL AS S DE.
OTHERWISE...NORTHWEST WINDS ARE EXPECTED TO BECOME GUSTY BETWEEN
20 AND 35 MPH FOR A COUPLE OF HOURS IMMEDIATELY SUBSEQUENT TO THE
COLD FRONTAL WINDSHIFT PASSAGE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
A BREEZY COOLER DAY IS EXPECTED SATURDAY. AS THICKNESSES DROP ACROSS
THE AREA, HIGH TEMPERATURES ARE EXPECTED TO BE 8 TO 13 DEGREES COOLER
THAN THEY WERE TODAY. NORTHWEST WINDS ARE EXPECTED TO PREVAIL ACROSS
THE AREA, WITH GUSTS OF 20-30 MPH POSSIBLE. THIS WILL MAKE IT FEEL
MUCH COOLER THAN THE ACTUAL AIR TEMPERATURE. WE ARE NOT EXPECTING
ANY PRECIPITATION UNTIL LATE IN THE DAY WHEN A SECONDARY AND MUCH
STRONGER COLD FRONT MAKES ITS WAY SEWD INTO OUR AREA WITH VERY LARGE
925-700 MB LAPSE RATES OF 8.5C/KM...LE MOISTURE INJECTED ESEWD AHEAD
OF THE FRONT WHICH STANDS A GOOD CHANCE OF YIELDING FLURRIES OR
POSSIBLY EVEN AN ISOLATED SNOW SQUALL ACROSS THE NORTHWESTERN
HILLY ZONES...ESPECIALLY ALONG AND N OF RTE 80.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THE TEMPERATURE DECLINE WILL CONTINUE SATURDAY NIGHT THROUGH MOST
OF SUNDAY ON ROBUST NORTHWEST WINDS CREATED BY A STRONG PRESSURE
GRADIENT OVER THE REGION. WINDS IN THE 20 TO 30 MPH RANGE CAN BE
EXPECTED, WITH HIGHER GUSTS ESPECIALLY ON SUNDAY WITH COLD AIR
ADVECTION. HIGH TEMPERATURES ON SUNDAY WILL ONLY REACH INTO THE
MID 20S UP NORTH, AND EVEN THE SOUTHERN AREAS WON/T GET OUT OF THE
MID 30S. WITH THE STRONG WINDS, THE SENSIBLE TEMPERATURES IN THE
NORTH WILL BE IN THE TEENS, AND IN THE 20S SOUTH. THIS WILL BE THE
COLDEST OUTBREAK OF THE SEASON SO FAR, AND WILL SEEM QUITE
HARSH...EVEN BY LATE NOVEMBER STANDARDS. A FEW LAKE EFFECT SNOW
FLURRIES/SHOWERS CANNOT BE RULED OUT...ESPECIALLY NORTH OF
I-78..SATURDAY NIGHT AND SUNDAY. WITH THE STRONG WINDS ON SUNDAY,
WE WILL BE KEEPING AN EYE OUT FOR BLOWOUT TIDES. BUT CURRENT MODEL
GUIDANCE SUGGESTS THERE SHOULD NOT BE A PROBLEM. AS HIGH PRESSURE
BUILDS OVER THE CAROLINAS SUNDAY NIGHT, WINDS WILL LESSEN, BUT
UNDER MAINLY CLEAR SKIES, TEMPERATURES COULD SINK DOWN TO THE LOW
TEENS IN THE NORTH AND LOW 20S SOUTH SUNDAY NIGHT. AS THE FLOW
BECOMES SOUTH- SOUTHWESTERLY ON MONDAY, TEMPERATURES WILL
MODERATE, AND WITH BENIGN WEATHER, CONDITIONS WILL BE MORE
TOLERABLE, ALTHOUGH STILL BELOW NORMAL FOR THIS TIME OF YEAR.
ATTENTION THEN TURNS TO THE NEXT COLD FRONT MOVING IN FROM THE
NORTHWEST TUESDAY NIGHT INTO WEDNESDAY AND A DEEPENING LOW PRESSURE
SYSTEM FROM THE GULF COAST. THE LATEST GFS HAS THIS FRONT SLOWING
DOWN AS IT REACHES THE COAST, WITH THE LOW MOVING NORTH ALONG IT,
MOVING OFF THE NORTH CAROLINA COAST WEDNESDAY AFTERNOON. THIS
SCENARIO WOULD STILL CAUSE PROBLEMS FOR THE REGION IN TERMS OF WIND,
AND POSSIBLY TIDAL ISSUES, BUT IT WOULD TEND TO KEEP THE BULK OF
THE PRECIPITATION SOUTH OF THE I-95 CORRIDOR WHERE IS SHOULD FALL
MAINLY AS RAIN. THE THREAT OF RAIN/SNOW SHOWERS NORTH OF I-95
CONTINUES, ALBEIT WITH LOWER AMOUNTS DUE TO THE TRACT.
UNFORTUNATELY, OTHER MODELS INDICATE A DIFFERENT SOLUTION. THE
CANADIAN MODEL DRAWS THE LOW INTO THE SLOWLY ADVANCING COLD FRONT
AND KEEPS IT MAINLY INLAND AS IT MOVES INTO NORTHERN NEW JERSEY LATE
TUESDAY NIGHT AND WELL OUT OF THE AREA BY LATE WEDNESDAY AFTERNOON. THIS
WOULD MEAN A WARMER AND FASTER SOLUTION, AND PERHAPS CAUSE LESS
CONCERN FOR ANY TIDAL ISSUES, BUT RAINFALL AMOUNTS COULD BE
HEAVIER. THE EUROPEAN MODEL PROJECTS THE LOW MOVING OFF THE JERSEY
COAST, ALMOST LIKE A BLEND OF THE GFS AND CANADIAN MODEL. THIS TRACK
WOULD MEAN HEAVIER RAINFALL AMOUNTS ALONG THE COASTLINE LIKE THE
CANADIAN SUGGESTS, BUT COULD INCREASE THE POTENTIAL FOR FROZEN
PRECIPITATION NORTH OF THE I-95 CORRIDOR.
GIVEN ALL THIS UNCERTAINLY, NO SIGNIFICANT CHANGES WERE MADE TO THE
WEATHER GRIDS FOR THIS SYSTEM IN AN ATTEMPT TO AVOID YO-YOING THE
FORECAST UNTIL A CLEARER SOLUTION EMERGES (HOPEFULLY) IN THE NEXT
FEW FORECAST CYCLES. WE WILL CONTINUE TO MENTION THE POTENTIAL FOR A
NOR`EASTER IN THE HWO AS WELL. BASED ON VARIOUS MODEL OUTPUT,
WEDNESDAY LOOKS LIKE THE ACTION DAY, WHICH OF COURSE FALLS ON A
BUSY TRAVEL DAY.
NO MATTER WHICH MODEL IS USED TO TRACK THE STORM SYSTEM TUESDAY
INTO WEDNESDAY, ALL MODELS AGREE WITH HIGH PRESSURE FROM THE
UPPER MIDWEST BUILDING EAST BEGINNING THANKSGIVING DAY, REACHING
THE COAST FRIDAY. WEATHER WILL BE GENERALLY BENIGN AND
TEMPERATURES WILL BE BELOW NORMAL.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...VFR CIGS MAY BRIEFLY LOWER TO MVFR CONDS IN SHOWERS THIS
EVENING THEN A GUSTY NW WIND OF 22-32KT FOLLOWS A COLD FRONTAL PASSAGE
FROM NW TO SE LATE THIS EVENING PER THE TAFS WITH SKIES BECOMING CLEAR
OR MOSTLY CLEAR AFTER 06Z OR 07Z.
SATURDAY...VFR SCT CLOUDS AOA 10000 FT WITH SCT-BKN CLOUDS DEVELOPING
AFTER 22Z AHEAD OF THE NEXT COLD FRONT VCNTY KTTN-KABE-KRDG. NW WIND
GUSTS AROUND 20 KT BECOMING W EARLY AFTERNOON...THEN NW TOWARD
00Z WITH GUSTS INCREASING TO 25 OR 30 KT.
OUTLOOK...
SAT NIGHT AND SUN...VFR. POSSIBLE LIGHT SNOW SHWRS, MAINLY
NORTHWEST OF KPHL. GUSTY NORTHWEST WINDS, MAINLY 15 TO 25 KTS.
HIGHER GUSTS TO 30 KTS AND PSBLY EVEN HIGHER ON SUN WITH MIXING.
HIGH CONFIDENCE.
SUN NIGHT THROUGH MON...VFR. DIMINISHING WINDS. NW WINDS BECMG SW
BY MONDAY NIGHT, MAINLY 10 KNOTS OR LESS. HIGH CONFIDENCE
TUESDAY...VFR EARLY WITH LOWER CONDITIONS AND RAIN POSSIBLY
DEVELOPING DEPENDING ON TRACK OF LOW PRESSURE DEVELOPING TO OUR
SOUTH. LOW CONFIDENCE.
TUESDAY NIGHT AND WED...IFR CONDITIONS POSSIBLE DEPENDING ON TRACK
OF LOW PRESSURE SYSTEM DEVELOPING TO OUR SOUTH. LOW CONFIDENCE.
&&
.MARINE...
A SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT TONIGHT INTO
SATURDAY AS WINDS ARE EXPECTED TO INCREASE TO ADVISORY LEVELS
TONIGHT BEHIND THE STRONG COLD FRONTAL PASSAGE AND CONTINUE INTO
SATURDAY. IT IS POSSIBLE THERE MAY BE A BRIEF DROP OFF IN WIND
GUSTS DURING THE AFTERNOON SATURDAY, BEFORE PICKING BACK UP DURING
THE EVENING, BUT WE WILL KEEP THE ADVISORY THROUGH THE DAY
SATURDAY.
SAT NIGHT AND SUN...NW WINDS WILL INCREASE AS THE PRESSURE GRADIENT
OVER THE REGION TIGHTENS, COUPLED WITH COLD AIR ADVECTION. GUSTS
AROUND 40 KT EXPECTED ON SUNDAY. GALE WARNINGS HAVE BEEN POSTED
STARTING SATURDAY EVENING GIVEN THE HIGH CONFIDENCE IN THIS
SCENARIO. SEAS SHOULD INCREASE TO AROUND 6 FEET SUNDAY.
SUNDAY NIGHT INTO MONDAY...WIND GUSTS DIMINISH WITH TIME AS THE
PGRAD RELAXES AND SURFACE HIGH PRESSURE BUILDS OVER THE REGION.
WINDS AND SEAS DECREASE TO SCA LEVELS SUNDAY NIGHT, FOLLOWED BY
SUB- ADVISORY CONDITIONS DURING MONDAY.
TUESDAY...OVERALL, SUB-ADVISORY CONDITIONS EXPECTED AT THIS TIME,
BUT THE TRACK OF DEVELOPING LOW PRESSURE TO OUR SOUTH MAY LEAD TO
SOME STRONGER WIND GUSTS OR INCREASING SEAS. DEPENDING ON THE
TRACK OF THE LOW, THERE COULD BE A NEED FOR SCA FLAGS AT SOME
POINT LATER TUE, BUT CONFIDENCE REMAINS LOW.
&&
.FIRE WEATHER...
COLD/DRY AIR WILL MOVE ACROSS THE AREA ON SUNDAY BEHIND A STRONG
COLD FRONT TONIGHT /SATURDAY MORNING. THERE IS SOME PRECIPITATION
EXPECTED WITH THE FRONTAL PASSAGE, BUT IT IS EXPECTED TO BE LIGHT.
WITH VERY STRONG WINDS EXPECTED AND THE DRY AIR EXPECTED, THE THREAT
FOR FIRE SPREAD WILL LIKELY INCREASE ON SUNDAY.
&&
.CLIMATE...
A REEVALUATION OF TEMPS THE REMAINDER OF NOVEMBER AT PHL YIELDS A
PROBABLE MUCH COLDER OUTCOME FOR THE MONTH...PROBABLY CLOSER TO
2.5 TO 3 DEGS BELOW NORMAL! CONSIDERING THAT WE`RE ABOUT HALF A
DEGREE BELOW NORMAL NOW... THAT MEANS THE PERIOD FROM THE 24TH
THROUGH THE 29TH WILL PROBABLY BE VERY COLD HERE...THAT 6 DAY PERIOD
DRIVING THE AVERAGE DEPARTURE FOR THE ENTIRE MONTH DOWN BY AT LEAST
2 DEGREES.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST SATURDAY FOR ANZ430-431-
450>455.
GALE WARNING FROM 6 PM SATURDAY TO 6 PM EST SUNDAY FOR ANZ430-
431-450>455.
&&
$$
SYNOPSIS...MIKETTA
NEAR TERM...DRAG/MIKETTA 741P
SHORT TERM...MIKETTA
LONG TERM...ROBERTSON
AVIATION...DRAG/ROBERTSON/MIKETTA 741P
MARINE...DRAG/ROBERTSON/MIKETTA
FIRE WEATHER...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MIAMI FL
932 AM EST THU NOV 21 2013
.UPDATE...
SOMEBODY APPARENTLY FORGOT TO FLIP THE CALENDAR AS THE 12Z MFL
SOUNDING LOOKS MORE LIKE EARLY TO MID OCTOBER WITH PWAT CLOSE TO
TWO INCHES AND CAPE OF OVER 1000 J/KG. WATER VAPOR IMAGERY
CONTINUES TO SHOW ZONAL FLOW ACROSS THE PENINSULA WITH A DEEP
PLUME OF MOISTURE STRETCHING FROM THE WESTERN GULF OF MEXICO INTO
THE ATLANTIC WITH SURFACE ANALYSIS SHOWING AN OLD DECAYING FRONTAL
BOUNDARY LYING UNDERNEATH. SOUTH FLORIDA IS IN THE WARM SECTOR AND
PLENTY OF DIURNAL HEATING WILL TAKE PLACE TODAY WITH AMPLE
SUNSHINE SOUTH OF A CLOUD DECK THAT IS LOCATED NEAR LAKE
OKEECHOBEE. THE SOUNDING ALSO SHOWS THE LOW LEVEL FLOW HAS BECOME
MORE EASTERLY BUT THEN BECOMES WESTERLY ABOVE 12-13 K FEET.
CURRENTLY ONGOING IS A BAND OF SHOWERS EAST OF PALM BEACH COUNTY
AND THE TREND WILL BE FOR ADDITIONAL ACTIVITY TO BUILD INLAND FROM
THIS BAND IN THE LOW LEVEL FLOW AND THEN SLOWLY PROPAGATE INLAND.
THIS IS WHAT THE HRRR SHOWS WHICH THEREFORE SEEMS REASONABLE AND
IT HAS BEEN PERFORMING QUITE WELL OVER THE LAST FEW DAYS. THE
WESTERLY FLOW ALOFT WILL OFFSET THE LOW LEVEL EASTERLIES AND ONCE
CONVECTION DEVELOPS INTO A FEW THUNDERSTORMS, MOVEMENT WILL BE
VERY SLOW SO THE POSSIBILITY OF LOCALLY HEAVY RAINS STILL WILL BE
PRESENT. IN ADDITION, THE ATMOSPHERE HAS DESTABILIZED SOMEWHAT
FROM 24 HOURS AGO AND CONVECTION WILL LIKELY DEVELOP OVER THE
MAINLAND EARLIER WHICH THE HRRR ALSO DEPICTS.
KOB
&&
.PREV DISCUSSION... /ISSUED 609 AM EST THU NOV 21 2013/
AVIATION...
ISOLATED TO SCATTERED SHOWERS WILL CONTINUE OVER THE EAST COAST
TAF SITES TODAY INTO TONIGHT. SO WILL KEEP VCSH IN THE EAST COAST
TAF SITES THROUGH TONIGHT. THE WINDS WILL INCREASE FROM LIGHT AND
VARIABLE EARLY THIS MORNING TO 5 TO 10 KNOTS FROM THE EAST BY LATE
THIS MORNING INTO EARLY THIS AFTERNOON. THE CEILING AND VIS WILL
ALSO REMAIN IN THE VFR CONDITIONS TODAY INTO TONIGHT FOR THE EAST
COAST TAF SITES DUE TO THE UNKNOWN TIMING OF THE SHOWERS.
FOR KAPF TAF SITE...THE WINDS WILL REMAIN EASTERLY TODAY INTO
TONIGHT WITH SPEEDS OF 5 KNOTS OR LESS EXCEPT 5 TO 10 KNOTS DURING
THE AFTERNOON HOURS. THERE COULD BE SOME SHOWERS THIS AFTERNOON AT
KAPF TAF SITE...SO WILL KEEP THE VCSH IN THE FORECAST BETWEEN 15Z
AND 23Z TODAY. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR
CONDITIONS AT KAPF TAF SITE.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 346 AM EST THU NOV 21 2013/
SHORT TERM (TODAY-SATURDAY)...
DEEP MOISTURE PLUME EXTENDING FROM EAST TO WEST ALONG AND AHEAD OF A
STALLED FRONTAL BOUNDARY WILL CONTINUE TO SUPPORT SCATTERED SHOWERS
AND A FEW THUNDERSTORMS THROUGH A GOOD PORTION OF THE SHORT-TERM
PERIOD. MODEL SOUNDINGS AROUND THE LOCAL AREA REFLECT THIS MOIST
ENVIRONMENT AND SHOW PRECIPITABLE WATER VALUES RANGING FROM 1.6-1.9"
THROUGH FRIDAY...THEN DECREASING INTO THE 1.25-1.5" RANGE THROUGH
THE DAY SATURDAY AS SOME DRIER AIR FILTERS IN FROM NORTH TO SOUTH
AND THE BOUNDARY CONTINUES TO DIMINISH. RECENTLY ANIMATED WATER
VAPOR LOOP SHOWED MOSTLY ZONAL FLOW ACROSS THE REGION WITH PLENTY OF
MID/UPPER MOISTURE STREAMING OVERHEAD. THE LATEST SHORT-RANGE MODEL
GUIDANCE INDICATES RISING UPPER HEIGHTS AS A RIDGE BUILDS OVERHEAD
THROUGH FRIDAY. TEMPERATURES WILL REMAIN SEVERAL DEGREES ABOVE
AVERAGE WITH OVERNIGHT LOWS RANGING FROM THE MID 60S INLAND TO THE
LOWER 70S ALONG THE EAST COAST/METRO LOCATIONS EACH NIGHT. AFTERNOON
HIGHS ARE FORECAST TO REACH THE LOW TO MID 80S EACH DAY. THIS
COMBINED WITH DEWPOINTS REMAINING IN THE UPPER 60S WILL KEEP THE
HUMID CONDITIONS IN PLACE.
LONG TERM (SUNDAY-THURSDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS CONSISTENT AND IN DECENT
AGREEMENT ON THE LARGE SCALE SHOWING A QUITE PROGRESSIVE PATTERN
THROUGH THE UPCOMING WEEK FEATURING TWO FRONTAL BOUNDARIES OF
INTEREST TO OUR LOCAL AREA. THE FIRST OF THE TWO IS FORECAST TO
APPROACH AND MOVE THROUGH THE LOCAL AREA THROUGH THE DAY SUNDAY.
ALTHOUGH VERY LITTLE SENSIBLE WEATHER IS ANTICIPATED WITH THIS
BOUNDARY DUE TO A LIMITED SOURCE OF DEEP LAYER MOISTURE...THE MAIN
IMPACTS WILL COME ALONG THE COAST AND OUT ACROSS THE ADJACENT
COASTAL WATERS DUE TO STRONG NORTHEAST WINDS AND BUILDING SEAS/SURF
IN THE WAKE OF THE BOUNDARY...ESPECIALLY OVER THE ADJACENT ATLANTIC
WATERS. THIS WILL TRANSLATE TO A PERIOD OF HAZARDOUS RIP CURRENTS
ALONG THE EAST COAST BEACHES FROM JUPITER TO MIAMI BEACH LATE SUNDAY
THROUGH MONDAY.
FOR THE SECOND SYSTEM...CYCLOGENESIS IN RESPONSE TO A STRONG
SHORTWAVE TROUGH IS FORECAST THROUGH THE DAY MONDAY ALONG THE TEXAS
COAST BEFORE RACING ENE ALONG THE NORTHERN GULF COAST THROUGH
TUESDAY. A COLD FRONT ASSOCIATED WITH THIS FEATURE WILL APPROACH THE
FLORIDA PENINSULA THROUGH THIS TIME AND SWEEP THROUGH OUR LOCAL AREA
THROUGH THE DAY WEDNESDAY. THERE ARE SOME MINOR TIMING DIFFERENCES
BETWEEN THE GFS AND ECMWF DUE TO A MORE PROGRESSIVE ECMWF SOLUTION.
ALTHOUGH THERE REMAINS PLENTY OF UNCERTAINTY BEING THIS FAR OUT INTO
THE PERIOD...WE WILL ADVERTISE HIGHER RAIN CHANCES ASSOCIATED WITH
THIS BOUNDARY DUE TO BETTER FORCING AND MOISTURE ALONG AND AHEAD OF
THE FRONTAL BOUNDARY. DESPITE THE TWO FRONTAL PASSAGES NEXT WEEK...
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE AVERAGE THROUGH THE
EXTENDED PERIOD.
AVIATION...
ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TO AFFECT THE EAST
COAST TAF SITES TODAY...AS THE WINDS WILL REMAIN LIGHT AND
VARIABLE EARLY THIS MORNING INCREASING TO 5 TO 10 KNOTS FROM THE
EASTERLY DIRECTION LATE THIS MORNING INTO EARLY AFTERNOON. KFLL
AND KFXE COULD EVEN SEE HEAVY RAINFALL OFF AND ON IN THE NEXT
COUPLE OF HOURS WITH VIS AND CEILING FALL INTO THE MVFR
CONDITIONS. SO HAVE ADDED A TEMPO GROUP FOR THE VIS AND CEILING
UNTIL 08Z FOR KFLL AND KFXE TAF SITES. THE CEILING AND VIS OVER
REST OF THE EAST COAST TAF SITES WILL REMAIN IN THE VFR CONDITIONS
WITH VCSH.
THE WINDS AT KAPF TAF SITE WILL REMAIN LIGHT AND VARIABLE THROUGH
EARLY THIS MORNING BEFORE INCREASING TO 5 TO 10 KNOTS FROM THE
EASTERLY DIRECTION LATE THIS MORNING IN EARLY THIS AFTERNOON. THE
WEATHER WILL REMAIN DRY THROUGH 15Z BEFORE SOME SHOWERS COULD
AFFECT THE TAF SITE FOR THE AFTERNOON HOURS. SO HAVE ADDED VCSH TO
KAPF TAF SITE AFTER 15Z TODAY. THE CEILING AND VIS WILL REMAIN IN
THE VFR CONDITIONS TODAY...DUE TO THE UNKNOWN TIMING OF THE
SHOWERS.
BNB
MARINE...
LIGHT WINDS WILL REMAIN IN PLACE ACROSS THE LOCAL WATERS THROUGH
FRIDAY AS A FRONTAL BOUNDARY STALLS OVER THE AREA. THE BEST CHANCE
FOR SHOWERS AND STORMS WILL REMAIN ALONG THE ATLANTIC COAST INTO
FRIDAY. A SMALL TO MODERATE NORTHERLY SWELL ASSOCIATED WITH FRESH TO
STRONG NORTHEAST WINDS NORTH OF THE FRONT WILL CONTINUE TO SPREAD
SOUTH OVER THE ATLANTIC WATERS THROUGH THE REMAINDER OF THE WEEK. A
STRONG COLD FRONT WILL PUSH THROUGH THE MARINE AREA BY THE END OF
THE WEEKEND WITH STRONG NORTHEAST WINDS AND BUILDING SEAS EXPECTED
SUNDAY NIGHT THROUGH MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 74 83 70 / 50 50 40 20
FORT LAUDERDALE 83 75 82 74 / 50 40 40 20
MIAMI 84 73 83 72 / 40 40 40 20
NAPLES 86 68 85 68 / 40 20 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
359 AM EST THU NOV 21 2013
.DISCUSSION...
CURRENTLY...
EVENING SOUNDINGS CAME IN QUITE MOIST WITH BOTH KTBW/KMFL PWAT
VALUES NEARING 2.0". EVEN SO...LATEST RUC ANALYSIS SHOWS A POCKET OF
RELATIVELY DRY AIR IMMEDIATELY UPSTREAM WITH H100-H70 MEAN RH VALUES
DROPPING FROM AOA 90PCT OVER THE PENINSULA TO BLO 75PCT N OF THE
BAHAMAS. WEAK UPR LVL SUPPORT AS THE H30-H20 WINDS OVERHEAD ARE ARE
AOB 50KTS. HOWEVER...LCL H85-H50 VORT MAXES ALONG THE WEAKENING
BOUNDARY OVER S FL HAVE BEEN PROVIDING SUFFICIENT MID LVL SUPPORT TO
MAINTAIN SCT SHRA ACTIVITY OVER THE ATLC. DESPITE FAIRLY COOL TEMPS
ALOFT (H70 ARND 6C...H50 BTWN -8C AND -9C) LAPSE RATES ACRS THE
REGION ARE QUITE WEAK...GENERALLY AOB 5.5C/KM.
TODAY-TONIGHT...
THE CENTER OF THE LARGE H100-H70 RIDGE AXIS BLANKETING THE ERN CONUS
WILL PUSH OFF THE NEW ENGLAND COAST AND STEADILY WEAKEN. AS IT
DOES...ITS SRN EXTENSION TO BECOME DOMINANT OVER THE MID ATLC. THE
STATIONARY FRONTAL BOUNDARY OVER S FL WILL WASH OUT...ALLOWING THE
RELATIVELY TIGHT PGRAD TO THE N TO EXPAND SWD...RESULTING IN A DEEP
AND STEADY ERLY BREEZE ACRS CENTRAL FL.
DESPITE DECREASING MOISTURE UPSTREAM AND A WEAK THERMODYNAMIC
PROFILE...SHRA ACTIVITY OVER THE ATLC HAS PERSISTED FOR SVRL HRS.
DEPTH AND STRENGTH OF THE ONSHORE FLOW WILL CONTINUE TO PUSH POCKETS
OF ENHANCED MOISTURE ONSHORE...WILL STICK CLOSE TO MOS GUIDANCE FOR
PRECIP AND WORD FOR COVERAGE...NO THUNDER AS THE SUPPORT AND
INSTABILITY OVERHEAD AND UPSTREAM ARE TOO WEAK. WILL GO WITH
50-60PCT ALONG THE TREASURE COAST...40-50PCT SPACE COAST...
DECREASING TO 30-40PCT OVER THE INTERIOR FOR TODAY...DECREASING TO
20-30PCT S OF I-4...LESS THAN 20PCT N OF I-4.
DEEP ONSHORE FLOW AND MID/UPR LVL CLDS WILL RESULT IN FAIRLY UNIFORM
MAX TEMPS IN THE U70S ALONG THE COAST...L80S INTERIOR. MIN TEMPS
WILL BE QUITE MILD FOR LATE FALL...U60S/M70S ALONG THE COAST...
M/U60S INTERIOR...A SOLID 10-15F ABV AVG.
FRI...
HIGH PRESSURE RIDGE VICINITY OF THE CAROLINAS EARLY WILL WEAKEN
AND SHIFT SOUTHEAST AS A COLD FRONT PUSHES TOWARDS THE SOUTHEAST
STATES. THIS WILL CAUSE ONSHORE FLOW TO WEAKEN. THE GFS HAS GONE
BACK TO A LITTLE MORE DRYING WITH THIS RUN AND WITH THE WEAKENING
LOW LEVEL FLOW...THE MODEL FOCUSES POPS IN SOUTHERN SECTIONS...WITH
VALUES LESS THAN 10 PERCENT IN THE NORTH. WITH SOME WEAK RIDGING
ALOFT AND SUBSIDENCE WILL FOLLOW CLOSE TO THE MOS NUMBERS.
WEEKEND...
WEAK HIGH PRESSURE RIDGE WILL EXTEND OVER THE AREA ON SAT THEN A
COLD FRONT IS SHOWN ON OUR DOORSTEP FIRST THING SUNDAY MORNING.
PRE FRONTAL CONVERGENCE WILL BE WEAK SO WILL JUST MAINTAIN A
SLIGHT CHANCE FOR SHOWERS AS PER MOS GUIDANCE...EVEN THOUGH MOS IS
ALREADY SHOWING DRYING OCCURRING IN THE NORTH BY EARLY SUNDAY. THE
MAIN STORY SUNDAY WILL BE GUSTY NORTHERLY WINDS WHICH SHOULD
REQUIRE AT LEAST A LAKE WIND ADVISORY AND MAYBE EVEN A STRAIGHT
WIND ADVISORY AS 925 MB WINDS ARE FORECAST 25-30 KNOTS IN THE
AFTERNOON. TEMPS WILL CONTINUE ABOVE NORMAL SAT AND SAT NIGHT THEN
ON SUNDAY MAX TEMPS MAY STRUGGLE TO REACH 70 IN THE NORTH AND MID
70S CENTRAL. SOUTHERN SECTIONS MIGHT REACH THE UPPER 70S BEFORE
COLD ADVECTION KICKS IN.
MON-THU...
EARLY TO MID WEEK LOOKS LIKE A QUITE DYNAMIC PERIOD AS THE MODELS
ARE STILL DEVELOPING A LOW IN THE NORTHWEST GULF OF MEXICO ON MON
AND MOVING IT EAST/NORTHEAST THROUGH WED. THE GFS IS A TAD SLOWER
AND FARTHER SOUTH THAN THE ECMWF BUT OVERALL THE MODELS ARE IN
DECENT AGREEMENT.
ON MON...THE COOL/DRY AIR MASS WILL MODIFY AS LOW LEVEL FLOW
BECOMES EASTERLY. MOS HAS SLIGHT CHANCE POPS ACROSS THE SOUTH AS
SURFACE DEW POINTS ARE FORECAST TO MODIFY INTO THE UPPER 50S BUT
THE NORTH LOOKS TOO DRY FOR MENTIONABLE POPS WITH DEW POINTS IN THE
LOWER 50S.
MON NIGHT THE GFS SHOWS INCREASING EAST/SOUTHEAST LOW LEVEL FLOW
AND SOME ISENTROPIC LIFT DEVELOPING. EXPECT SOME ONSHORE MOVING
SHOWERS ALONG THE COAST AND THERE MAY ALSO BE SOME AREAS OF RAIN
BREAKING OUT. MOS POPS ARE AROUND 25 PERCENT AND WILL GO WITH THAT
ACROSS THE AREA.
FOR TUE AND WED...THE GFS SHOWS A BAND OF HIGHER MOISTURE LIFTING
NORTH ACROSS THE AREA TUE ALONG PSEUDO WARM FRONT. WITH
INCREASING LOW LEVEL WINDS IN RESPONSE TO LOW CENTER WHICH IS FORECAST
TO BE VICINITY MISSISSIPPI DELTA REGION...WILL INTRODUCE A SLIGHT
CHANCE FOR STORMS IN ADDITION TO BUMPING POPS TO 40 PERCENT
THROUGH THE PERIOD.
THE GENERAL SYNOPTIC PATTERN IS SUGGESTIVE OF A THREAT FOR STRONG-
SEVERE STORMS DUE TO DEEPENING LOW PRESSURE CLOSE TO THE STATE.
THE GFS SHOWED THE ASSOCIATED MID LEVEL SHORTWAVE TROUGH TAKING
ON A SLIGHT NEGATIVE TILT...HOWEVER QUITE STRONGLY DIFFLUENT FLOW
ALOFT SUGGESTS CONSIDERABLE DEBRIS CLOUDINESS OVERSPREADING THE
WARM SECTOR...LIMITING INSTABILITY.
TIMING IS FAR FROM CERTAIN AT THIS POINT AND THERE IS PLENTY OF
TIME TO REFINE THE FORECAST.
SNEAK PEAK FOR THANKSGIVING DAY...THE MODELS SHOW COLD FRONT EAST
OF THE AREA EARLY SO EXPECT A DRIER AIR MASS AND COOLER TEMPS.
&&
.AVIATION...
THRU 21/15Z...ERLY LLWS FL015 INTERIOR SITES...OCNL SFC WND G22KTS
ALONG THE COAST S OF KTIX...W OF KMLB-KOBE PREVAILING CIGS BTWN
FL060-080 WITH ISOLD MVFR COASTAL SHRAS N OF KTIX...E OF KMLB-KOBE
PREVAILING CIGS BTWN FL040-060 WITH SCT MVFR SHRAS.
BTWN 21/15Z-21/23Z...OCNL SFC WND G18-22KTS N OF KVRB-KISM...
PREVAILING CIGS BTWN FL040-060 WITH SCT MVFR SHRAS...BRIEF IFR VSBYS
IN +SHRAS.
AFT 21/23Z...PREVAILING CIGS BTWN FL080-100...CHC MVFR SHRAS S OF
KMLB-KOBE...SLGT CHC N OF KMLB-KOBE.
&&
.MARINE...
TODAY-TONIGHT...LCL DATA BUOY/C-MAN NETWORK SHOWING A CONSISTENT
15-20KTS OF ERLY FLOW WITH 5-7FT SEAS NEARSHORE AND 8-9FT OFFSHORE.
HOWEVER...BUOY012 IS STARTING TO PICK UP A NEW SWELL TRAIN...ONE
WITH DOMINANT PDS BTWN 11-12SEC AS OPPOSED TO BUOY008/009 WHOSE
DOMINANT PDS ARE BTWN 8-9SEC.
WHILE THE LONGER SWELL PD WILL HELP DAMPEN THE ROUGH SEAS...
CONDITIONS WILL REMAIN HAZARDOUS FOR SMALL CRAFT. THE CENTER OF
A LARGE HIGH PRES RIDGE OVER THE ERN CONUS WILL PUSH OFF THE NEW
ENGLAND COAST AND WEAKEN. THIS WILL ALLOW THE SRN EXTENSION OF THE
RIDGE TO BECOME DOMINANT AND BUILD OVER THE MID ATLC. LCL SFC/BNDRY
LYR WINDS WILL WEAKEN...ALBEIT SLOWLY..AS THE REDEVELOPING RIDGE
KEEPS A FAIRLY TIGHT PGRAD ACRS THE REGION...ONE CAPABLE OF
MAINTAINING A MODERATE TO FRESH ERLY BREEZE ACRS THE LCL ATLC. WILL
NEED TO ADJUST THE TIMING OF THE CURRENT SCA...AT MINIMUM PLANS ARE
TO EXTEND IT FOR THE OFFSHORE LEG THRU 22/09Z.
FRI-SAT...HIGH PRESSURE RIDGE NORTH OF THE AREA FRI WILL WEAKEN AND
SHIFT SOUTHEAST AHEAD OF A COLD FRONT. EASTERLY FLOW WILL
GRADUALLY WEAKEN FRI BUT THE COMBINATION OF WINDS AND SEAS SHOULD
PRODUCE POOR-HAZARDOUS CONDITIONS FOR SMALL CRAFT. WILL GO WITH AN
ADVISORY FOR SEAS THROUGH FRI AFTERNOON AS WINDS WILL BE CLOSE TO
15 KNOTS THEN AND SEAS STILL 5-8 FEET.
THE GOOD NEWS LOOKS TO BE THAT ON SAT THE WINDS WILL DIMINISH TO
5-10 KNOTS. CONDITIONS TRAVERSING THE INLETS MAY STILL BE
HAZARDOUS THOUGH AS SWELLS 4-5 FEET CONTINUE IN THE ATLANTIC.
SUN-MON...STRONG COLD FRONT IS STILL PROGGED TO SWEEP FROM THE
NORTHERN WATERS EARLY IN THE DAY TO SOUTH OF THE WATERS BY
AFTERNOON. MODEL LOW LEVEL WINDS STILL SUGGEST THAT NORTHERLY
WINDS GUSTING TO 30 KNOTS WILL BE POSSIBLE. THE FLOW WILL SWING
AROUND TO THE NORTHEAST/EAST ON MON AND STILL LOOK QUITE GUSTY
20-25 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 78 68 80 63 / 40 20 10 10
MCO 82 67 82 63 / 30 20 10 10
MLB 80 73 81 66 / 50 30 20 10
VRB 80 73 81 66 / 50 30 30 10
LEE 81 65 82 62 / 30 20 10 10
SFB 82 67 82 63 / 30 20 10 10
ORL 82 67 82 64 / 30 20 10 10
FPR 81 73 81 66 / 60 30 30 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20
NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM-WATERS FROM FLAGLER BEACH TO
VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS
FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-
WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET
20 TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 AM TO 4 PM EST
FRIDAY FOR COASTAL WATERS FROM FLAGLER BEACH TO VOLUSIA
BREVARD COUNTY LINE OUT 20 NM-COASTAL WATERS FROM SEBASTIAN
INLET TO JUPITER INLET OUT 20 NM-COASTAL WATERS FROM
VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET OUT 20 NM-
WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20
TO 60 NM OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER
INLET 20 TO 60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD
COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
929 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE MOVING OFF THE COAST OF THE NORTHEAST STATES WILL
DIRECT A MOIST ONSHORE FLOW INTO THE FORECAST AREA TODAY AND
TONIGHT. WEAK HIGH PRESSURE WILL BE OVER THE AREA FRIDAY. AN
APPROACHING COLD FRONT WILL MOVE INTO THE REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISENTROPIC LIFT OVER THE PRESSURE RIDGE EXTENDING INTO THE
FORECAST AREA FROM THE NORTH WILL BRING CLOUDY SKIES TODAY. THE
NAM AND GFS SHOW BUILDING H5 HEIGHTS. BELIEVE THE MOISTURE WILL
REMAIN SHALLOW SO ANY RAINFALL SHOULD BE LIGHT AND IT IS
QUESTIONABLE WHETHER MEASURABLE RAIN WILL OCCUR. EXPECT MOST
OF THE AREA WILL HAVE OCCASIONAL SPRINKLES. USED AN AVERAGE OF
THE GFS AND ECMWF MOS FOR THE POP FORECAST. THE CHANCE OF
MEASURABLE RAIN WILL BE HIGHEST IN THE SOUTH AND WEST WHERE
MOISTURE WILL BE A LITTLE DEEPER. THE HRRR INDICATES GREATER
COVERAGE OF RAIN AREAS IN SOUTH AND WEST SECTIONS TODAY. WE USED
THE COOLER TEMPERATURE GUIDANCE BECAUSE OF THE WEDGE PATTERN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
ISENTROPIC LIFT OVER THE WEDGE RIDGE WILL CONTINUE TO BRING
CLOUDINESS TONIGHT. THE NAM AND GFS MOS POPS WERE IN POOR
AGREEMENT. THE NAM MOS DISPLAYED CATEGORICAL POPS WHILE THE GFS
MOS HAD SLIGHT CHANCE POPS. WE HAVE CONTINUED TO LEAN TOWARD THE
MORE CONSISTENT GFS...THINKING THE MOISTURE WILL REMAIN SHALLOW
UNDER H5 RIDGING. HOWEVER...EXPECT OCCASIONAL SPRINKLES WITH MORE
OF A CHANCE OF MEASURABLE RAIN IN THE SOUTH AND WEST CLOSER TO
DEEPER MOISTURE. THE NAM AND GFS SHOW LESS ISENTROPIC LIFT LATE
TONIGHT AS THE LOW-LEVEL FLOW DIMINISHES WITH WEAK HIGH PRESSURE
SETTLING OVER THE AREA. HIGH LOW-LEVEL MOISTURE AND LIGHT WIND
WILL LIKELY LEAD TO FOG. ALL OF THE GFS AND NAM MOS INDICATE FOG
LATE TONIGHT INTO FRIDAY MORNING. THE FOG MAY BECOME DENSE. WEAK
HIGH PRESSURE SHOULD REMAIN OVER THE AREA FRIDAY INTO FRIDAY NIGHT
AHEAD OF THE APPROACHING COLD FRONT. SUPPORT FOR RAIN APPEARS WEAK
DURING THIS TIME WITH THE MAIN FORCING ASSOCIATED WITH THE FRONT
STILL WEST OF THE AREA. WE USED THE GUIDANCE CONSENSUS FOR THE LOW
TEMPERATURE TONIGHT. USED THE COOLER HIGH TEMPERATURE GUIDANCE
BECAUSE OF CLOUDINESS FRIDAY. BELIEVE THE WARMER LOW TEMPERATURE
GUIDANCE IS BETTER FRIDAY NIGHT BECAUSE OF MIXING AHEAD OF THE
FRONT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT DURING THE MEDIUM-RANGE
PERIOD. THE MODELS DISPLAY A COLD FRONT MOVING THROUGH THE AREA
SATURDAY. MOST OF THE MOS GUIDANCE INDICATES CHANCE POPS SATURDAY AND
THIS APPEARS REASONABLE WITH H85 WESTERLY FLOW AHEAD OF THE FRONT
LIMITING CONVERGENCE AND MOISTURE. DRY AND COLD HIGH PRESSURE
SHOULD DOMINATE BEHIND THE FRONT FOR SUNDAY THROUGH MONDAY. THE GFS...
ECMWF...AND EKD MOS HAVE LOWS MAINLY IN THE MIDDLE 20S MONDAY
MORNING WITH THE HIGH OVER THE FORECAST AREA AND STRONG NET RADIATIONAL
COOLING. THE MODELS ARE ALSO IN GOOD AGREEMENT SHOWING LOW
PRESSURE FROM THE GULF OF MEXICO SPREADING DEEP MOISTURE INTO THE
FORECAST AREA FOR TUESDAY AND TUESDAY NIGHT. WE HAVE FORECASTED
LIKELY POPS BECAUSE OF THE MODEL CONSISTENCY. THE ECMWF WAS A
LITTLE FASTER LIFTING THE LOW NORTHEAST OF THE AREA WEDNESDAY SO
WE DID NOT FORECAST QUITE SO HIGH A POP ON THAT DAY. THE MODELS
INDICATE ENOUGH WARMING WILL OCCUR AHEAD OF THE SYSTEM FOR AN ALL-
LIQUID EVENT.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN MVFR CEILINGS WITH DETERIORATING CONDITIONS
TONIGHT.
WEAK ISENTROPIC LIFT OVER THE SURFACE HIGH PRESSURE SYSTEM
CURRENTLY IN PLACE HAS RESULTED IN MVFR STRATUS FOR TODAY. RADAR
CONTINUES TO SHOW PATCHY LIGHT RAIN OR SPRINKLES WHICH ARE
EXPECTED FOR MUCH OF THE DAY. THIS ACTIVITY IS NOT EXPECTED TO
BE MUCH IMPACT AT THE TERMINALS WITH MINIMAL IMPACT. MVFR
CEILINGS BELOW 2000FT SHOULD PERSIST THROUGH EARLY AFTERNOON BUT
THINK CEILINGS WILL RISE ABOVE 2000FT AFTER 18Z ALL TERMINALS AND
LOW VFR CEILINGS MAY BRIEFLY OCCUR TIL AROUND 01Z-03Z CAE/CUB/OGB.
STRONG AGREEMENT IN THE MODEL GUIDANCE IN ABUNDANT LOW LEVEL
MOISTURE RESULTING IN DEVELOPING IFR CEILINGS AND VISIBILITY
REDUCTION INTO THE MVFR/IFR RANGE AFTER 03Z-06Z. WINDS THROUGH THE
PERIOD WILL BE FROM THE NORTHEAST...WITH WIND SPEEDS AROUND 5 TO
10 MPH THROUGH 21Z THEN GRADUALLY WEAKENING TO LESS THAN 5 MPH
OVERNIGHT.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE EARLY FRIDAY.
SHOWERS AND ASSOCIATED RESTRICTIONS LATE FRIDAY INTO SATURDAY AS A
COLD FRONT MOVES THROUGH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
649 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE MOVING OFF THE COAST OF THE NORTHEAST STATES WILL
DIRECT A MOIST ONSHORE FLOW INTO THE FORECAST AREA TODAY AND
TONIGHT. WEAK HIGH PRESSURE WILL BE OVER THE AREA FRIDAY. AN
APPROACHING COLD FRONT WILL MOVE INTO THE REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISENTROPIC LIFT OVER THE PRESSURE RIDGE EXTENDING INTO THE
FORECAST AREA FROM THE NORTH WILL BRING CLOUDY SKIES TODAY. THE
NAM AND GFS SHOW BUILDING H5 HEIGHTS. BELIEVE THE MOISTURE WILL
REMAIN SHALLOW SO ANY RAINFALL SHOULD BE LIGHT AND IT IS
QUESTIONABLE WHETHER MEASURABLE RAIN WILL OCCUR. EXPECT MOST
OF THE AREA WILL HAVE OCCASIONAL SPRINKLES. USED AN AVERAGE OF
THE GFS AND ECMWF MOS FOR THE POP FORECAST. THE CHANCE OF
MEASURABLE RAIN WILL BE HIGHEST IN THE SOUTH AND WEST WHERE
MOISTURE WILL BE A LITTLE DEEPER. THE HRRR INDICATES GREATER
COVERAGE OF RAIN AREAS IN SOUTH AND WEST SECTIONS TODAY. WE USED
THE COOLER TEMPERATURE GUIDANCE BECAUSE OF THE WEDGE PATTERN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
ISENTROPIC LIFT OVER THE WEDGE RIDGE WILL CONTINUE TO BRING
CLOUDINESS TONIGHT. THE NAM AND GFS MOS POPS WERE IN POOR
AGREEMENT. THE NAM MOS DISPLAYED CATEGORICAL POPS WHILE THE GFS
MOS HAD SLIGHT CHANCE POPS. WE HAVE CONTINUED TO LEAN TOWARD THE
MORE CONSISTENT GFS...THINKING THE MOISTURE WILL REMAIN SHALLOW
UNDER H5 RIDGING. HOWEVER...EXPECT OCCASIONAL SPRINKLES WITH MORE
OF A CHANCE OF MEASURABLE RAIN IN THE SOUTH AND WEST CLOSER TO
DEEPER MOISTURE. THE NAM AND GFS SHOW LESS ISENTROPIC LIFT LATE
TONIGHT AS THE LOW-LEVEL FLOW DIMINISHES WITH WEAK HIGH PRESSURE
SETTLING OVER THE AREA. HIGH LOW-LEVEL MOISTURE AND LIGHT WIND
WILL LIKELY LEAD TO FOG. ALL OF THE GFS AND NAM MOS INDICATE FOG
LATE TONIGHT INTO FRIDAY MORNING. THE FOG MAY BECOME DENSE. WEAK
HIGH PRESSURE SHOULD REMAIN OVER THE AREA FRIDAY INTO FRIDAY NIGHT
AHEAD OF THE APPROACHING COLD FRONT. SUPPORT FOR RAIN APPEARS WEAK
DURING THIS TIME WITH THE MAIN FORCING ASSOCIATED WITH THE FRONT
STILL WEST OF THE AREA. WE USED THE GUIDANCE CONSENSUS FOR THE LOW
TEMPERATURE TONIGHT. USED THE COOLER HIGH TEMPERATURE GUIDANCE
BECAUSE OF CLOUDINESS FRIDAY. BELIEVE THE WARMER LOW TEMPERATURE
GUIDANCE IS BETTER FRIDAY NIGHT BECAUSE OF MIXING AHEAD OF THE
FRONT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT DURING THE MEDIUM-RANGE
PERIOD. THE MODELS DISPLAY A COLD FRONT MOVING THROUGH THE AREA
SATURDAY. MOST OF THE MOS GUIDANCE INDICATES CHANCE POPS SATURDAY AND
THIS APPEARS REASONABLE WITH H85 WESTERLY FLOW AHEAD OF THE FRONT
LIMITING CONVERGENCE AND MOISTURE. DRY AND COLD HIGH PRESSURE
SHOULD DOMINATE BEHIND THE FRONT FOR SUNDAY THROUGH MONDAY. THE GFS...
ECMWF...AND EKD MOS HAVE LOWS MAINLY IN THE MIDDLE 20S MONDAY
MORNING WITH THE HIGH OVER THE FORECAST AREA AND STRONG NET RADIATIONAL
COOLING. THE MODELS ARE ALSO IN GOOD AGREEMENT SHOWING LOW
PRESSURE FROM THE GULF OF MEXICO SPREADING DEEP MOISTURE INTO THE
FORECAST AREA FOR TUESDAY AND TUESDAY NIGHT. WE HAVE FORECASTED
LIKELY POPS BECAUSE OF THE MODEL CONSISTENCY. THE ECMWF WAS A
LITTLE FASTER LIFTING THE LOW NORTHEAST OF THE AREA WEDNESDAY SO
WE DID NOT FORECAST QUITE SO HIGH A POP ON THAT DAY. THE MODELS
INDICATE ENOUGH WARMING WILL OCCUR AHEAD OF THE SYSTEM FOR AN ALL-
LIQUID EVENT.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN MVFR CEILINGS WITH DETERIORATING CONDITIONS
TONIGHT.
WEAK ISENTROPIC LIFT OVER THE SURFACE HIGH PRESSURE SYSTEM
CURRENTLY IN PLACE HAS RESULTED IN A LOWERING MVFR STRATUS DECK
EARLY THIS MORNING. RADAR SHOWING SOME PATCHY SPRINKLES OR EVEN A
POSSIBLE SHOWER AND THIS WILL LIKELY PERSIST THROUGH THE DAY TODAY
BUT THERE IS NOT EXPECTED TO BE MUCH IMPACT AT THE TERMINALS FROM
THESE LIGHT SHOWERS AND THEREFORE IS NOT INCLUDED IN THE FORECAST
DUE TO THE SCATTERED NATURE AND MINIMAL IMPACT. MVFR CEILINGS
BELOW 2000FT SHOULD PERSIST THROUGH EARLY AFTERNOON BUT THINK
CEILINGS WILL RISE ABOVE 2000FT AFTER 18Z ALL TERMINALS AND LOW
VFR CEILINGS MAY BRIEFLY OCCUR TIL AROUND 01Z-03Z CAE/CUB/OGB.
STRONG AGREEMENT IN THE MODEL GUIDANCE IN ABUNDANT LOW LEVEL
MOISTURE RESULTING IN DEVELOPING IFR CEILINGS AND VISIBILITY
REDUCTION INTO THE MVFR/IFR RANGE AFTER 03Z-06Z. WINDS THROUGH THE
PERIOD WILL BE FROM THE NORTHEAST...WITH WIND SPEEDS AROUND 5 TO
10 MPH THROUGH 21Z THEN GRADUALLY WEAKENING TO LESS THAN 5 MPH
OVERNIGHT.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE EARLY FRIDAY.
SHOWERS AND ASSOCIATED RESTRICTIONS LATE FRIDAY INTO SATURDAY AS A
COLD FRONT MOVES THROUGH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
543 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE MOVING OFF THE COAST OF THE NORTHEAST STATES WILL
DIRECT A MOIST ONSHORE FLOW INTO THE FORECAST AREA TODAY AND
TONIGHT. WEAK HIGH PRESSURE WILL BE OVER THE AREA FRIDAY. AN
APPROACHING COLD FRONT WILL MOVE INTO THE REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISENTROPIC LIFT OVER THE PRESSURE RIDGE EXTENDING INTO THE
FORECAST AREA FROM THE NORTH WILL BRING CLOUDY SKIES TODAY. THE
NAM AND GFS SHOW BUILDING H5 HEIGHTS. BELIEVE THE MOISTURE WILL
REMAIN SHALLOW SO ANY RAINFALL SHOULD BE LIGHT AND IT IS
QUESTIONABLE WHETHER MEASURABLE RAIN WILL OCCUR. EXPECT MOST
OF THE AREA WILL HAVE OCCASIONAL SPRINKLES. USED AN AVERAGE OF
THE GFS AND ECMWF MOS FOR THE POP FORECAST. THE CHANCE OF
MEASURABLE RAIN WILL BE HIGHEST IN THE SOUTH AND WEST WHERE
MOISTURE WILL BE A LITTLE DEEPER. THE HRRR INDICATES GREATER
COVERAGE OF RAIN AREAS IN SOUTH AND WEST SECTIONS TODAY. WE USED
THE COOLER TEMPERATURE GUIDANCE BECAUSE OF THE WEDGE PATTERN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
ISENTROPIC LIFT OVER THE WEDGE RIDGE WILL CONTINUE TO BRING
CLOUDINESS TONIGHT. THE NAM AND GFS MOS POPS WERE IN POOR
AGREEMENT. THE NAM MOS DISPLAYED CATEGORICAL POPS WHILE THE GFS
MOS HAD SLIGHT CHANCE POPS. WE HAVE CONTINUED TO LEAN TOWARD THE
MORE CONSISTENT GFS...THINKING THE MOISTURE WILL REMAIN SHALLOW
UNDER H5 RIDGING. HOWEVER...EXPECT OCCASIONAL SPRINKLES WITH MORE
OF A CHANCE OF MEASURABLE RAIN IN THE SOUTH AND WEST CLOSER TO
DEEPER MOISTURE. THE NAM AND GFS SHOW LESS ISENTROPIC LIFT LATE
TONIGHT AS THE LOW-LEVEL FLOW DIMINISHES WITH WEAK HIGH PRESSURE
SETTLING OVER THE AREA. HIGH LOW-LEVEL MOISTURE AND LIGHT WIND
WILL LIKELY LEAD TO FOG. ALL OF THE GFS AND NAM MOS INDICATE FOG
LATE TONIGHT INTO FRIDAY MORNING. THE FOG MAY BECOME DENSE. WEAK
HIGH PRESSURE SHOULD REMAIN OVER THE AREA FRIDAY INTO FRIDAY NIGHT
AHEAD OF THE APPROACHING COLD FRONT. SUPPORT FOR RAIN APPEARS WEAK
DURING THIS TIME WITH THE MAIN FORCING ASSOCIATED WITH THE FRONT
STILL WEST OF THE AREA. WE USED THE GUIDANCE CONSENSUS FOR THE LOW
TEMPERATURE TONIGHT. USED THE COOLER HIGH TEMPERATURE GUIDANCE
BECAUSE OF CLOUDINESS FRIDAY. BELIEVE THE WARMER LOW TEMPERATURE
GUIDANCE IS BETTER FRIDAY NIGHT BECAUSE OF MIXING AHEAD OF THE
FRONT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT DURING THE MEDIUM-RANGE
PERIOD. THE MODELS DISPLAY A COLD FRONT MOVING THROUGH THE AREA
SATURDAY. MOST OF THE MOS GUIDANCE INDICATES CHANCE POPS SATURDAY AND
THIS APPEARS REASONABLE WITH H85 WESTERLY FLOW AHEAD OF THE FRONT
LIMITING CONVERGENCE AND MOISTURE. DRY AND COLD HIGH PRESSURE
SHOULD DOMINATE BEHIND THE FRONT FOR SUNDAY THROUGH MONDAY. THE GFS...
ECMWF...AND EKD MOS HAVE LOWS MAINLY IN THE MIDDLE 20S MONDAY
MORNING WITH THE HIGH OVER THE FORECAST AREA AND STRONG NET RADIATIONAL
COOLING. THE MODELS ARE ALSO IN GOOD AGREEMENT SHOWING LOW
PRESSURE FROM THE GULF OF MEXICO SPREADING DEEP MOISTURE INTO THE
FORECAST AREA FOR TUESDAY AND TUESDAY NIGHT. WE HAVE FORECASTED
LIKELY POPS BECAUSE OF THE MODEL CONSISTENCY. THE ECMWF WAS A
LITTLE FASTER LIFTING THE LOW NORTHEAST OF THE AREA WEDNESDAY SO
WE DID NOT FORECAST QUITE SO HIGH A POP ON THAT DAY. THE MODELS
INDICATE ENOUGH WARMING WILL OCCUR AHEAD OF THE SYSTEM FOR AN ALL-
LIQUID EVENT.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN VFR VISIBILITIES THROUGH THE PERIOD...BUT LOWER
CONFIDENCE REGARDING CEILINGS.
STRONG SURFACE HIGH PRESSURE CONTINUES TO RIDGE DOWN THE EAST
COAST OVER THE FORECAST AREA. A WEAK UPPER DISTURBANCE MOVING OVER
THE REGION IS AIDING IN WEAK REFLECTIVITY RETURNS OVER THE
MIDLANDS AND CSRA THOUGH NO OBSERVATIONS REPORT PRECIPITATION.
WEAK ISENTROPIC LIFTING HAS RESULTED IN FAIRLY WIDESPREAD MVFR
CEILINGS ACROSS THE SOUTHEAST. CAE/CUB BEGIN FORECAST WITH MVFR
CEILINGS AND EXPECT AGS/DNL/OGB WILL LOWER INTO MVFR RANGE BY 08Z
DESPITE CONFLICTING MOS GUIDANCE. EXPECT MVFR CEILINGS TO PERSIST
THROUGH THE MORNING HOURS BEFORE CEILINGS RISE DUE TO DIURNAL
INSOLATION AROUND 18Z. CEILINGS LIKELY TO FALL BACK TO MVFR AFTER
03Z AS ONSHORE FLOW CONTINUES WITH WEAK ISENTROPIC LIFT. SPRINKLES
POSSIBLE THROUGH THE PERIOD BUT MEASURABLE RAIN CHANCES ARE LOW
AND WILL NOT INCLUDE IN FORECAST DUE TO LACK OF VISIBILITY
RESTRICTIONS EXPECTED. WINDS SHOULD REMAIN NORTHEASTERLY AROUND 5
TO 10 MPH THROUGH THE FORECAST PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE THRU THU NT/EARLY
FRI. SHOWERS AND ASSOCIATED RESTRICTIONS LATE FRIDAY INTO SATURDAY
AS A COLD FRONT MOVES THROUGH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
304 PM CST THU NOV 21 2013
.DISCUSSION...
304 PM CST
TONIGHT...
CONSIDERABLE SOLAR SHIELDING HAS KEPT TEMPERATURES IN CHECK FOR MUCH
OF THE DAY IN THE MID/UPR 40S...EXCEPT FOR THE FEW THIN SPOTS IN THE
CLOUDS THAT ALLOWED TEMPS TO QUICKLY BUMP TO 50 DEGREES. HOWEVER
THESE THIN SPOTS HAVE SINCE DISSIPATED. A QUASI-STATIONARY BOUNDARY
WAS ORIENTED FROM CENTRAL MISSOURI NORTHEAST THROUGH LEE/OGLE COUNTY
AND TO AROUND MILWAUKEE...THEN STRETCHING EAST ACROSS LOWER
MICHIGAN. NORTH OF THIS BOUNDARY SLIGHTLY DRIER AIR WAS BEGINNING TO
SEEP SOUTH/SOUTHEAST...MEANWHILE SOUTH OF THE BOUNDARY DEW PTS HAVE
RISEN INTO THE LOW/MID 40S. JUST WEST OF THE CWFA...TEMPS HAVE BEEN
ABLE TO COOL INTO LOW 30S AND PRECIP WAS FALLING AS A MIX OF
RA/SN/SLEET. ACROSS NORTHCENTRAL IOWA TEMPS ARE MUCH COOLER IN THE
20S AND PRECIP IS MAINLY LIGHT SNOW.
A VERY WEAK WAVE WILL RIDE ALONG THE FRONTAL BOUNDARY AND HELP TO
RE-DEVELOP PRECIP...SLOWLY OVERSPREADING THE REMAINDER OF NORTHERN
IL/NORTHWEST IN LATER THIS EVE. LATEST GUIDANCE COUPLED WITH
SOUNDINGS...SUGGEST ANY PRECIP OVER OUR CWFA THIS EVENING SHOULD
REMAIN IN LIQUID FORM AND BE LIGHT WITH MINIMAL LIFT IN THE NEAR SFC
ENVIRONMENT. HOWEVER AS THE BOUNDARY BEGINS TO SLOWLY SHIFT
SOUTHEAST OVERNIGHT...TEMPS WILL STEADILY COOL AND START TO
INTRODUCE A RAIN/SNOW MIX FOR THE FAR NORTH/NORTHWEST PORTIONS OF
THE CWFA.
TEMPS OVERNIGHT WILL HINGE UPON THE PLACEMENT OF THE FRONTAL
BOUNDARY...WITH TEMPS ALONG AND SOUTHEAST OF A PONTIAC TO CHICAGO
LINE HOLDING ARND 40 DEGREES. TO THE NORTHWEST OF THIS LINE TEMPS
WILL LIKELY FALL INTO THE MID/UPR 30S.
CONFIDENCE...HIGH.
FRIDAY THROUGH FRIDAY NIGHT...
MAIN FOCUS FOR FRI WILL BE ON THE ENDING TIME OF PRECIP...WHICH
GUIDANCE DIFFERS ON. WITH THE LACK OF A STRONG PUSH TO THE FRONTAL
BOUNDARY EARLY FRI...IT APPEARS LIGHT PRECIP/DRIZZLE/FLURRIES WILL
PERSIST FOR PORTIONS OF THE CWFA. AS THE DAY
PROGRESSES...ANTI-CYCLONIC FLOW ACROSS THE NORTHERN PLAINS WILL
SLIDE SOUTH/SOUTHEAST...AND HELP TO FURTHER ERODE ANY LINGERING
MOISTURE. LCL ARW 8KM SIMULATION INDICATES PRECIP ENDING ARND
13-15Z...HOWEVER RH FIELDS IN THE 1050-850MB LAYER HOLD TOUGH AT 90%
WOULD COULD SUGGEST SOME DRIZZLE/FLURRIES OR POSSIBLY A LGT RA/SN
MIX MAY BE PATCHY THRU MID-MORNING. NORTHERLY FLOW WILL STRENGTHEN
THROUGHOUT THE DAY...WHICH WILL HELP BRING LOWER DEW PTS AND ANY
LINGERING PRECIP THAT DOES ENCOUNTER A PARTIAL MELT WILL LIKELY
MAINTAIN THE DENDRITIC FORM BY LATE MORNING BEFORE DRYING BY EARLY
AFTN HOURS.
LCL WRF INDICATES A NARROW LAKE EFFECT SNOW BAND BEGINNING EARLY FRI
MORNING...PUSHING INTO SOUTHWEST LOWER MICHIGAN. AT THIS TIME IT
APPEARS FAR NORTHWEST IN WILL REMAIN WEST OF THIS BAND OF LIGHT
SNOW.
HIGH TEMPS ACROSS THE CWFA WILL OCCUR IN THE MORNING HOURS...HOLDING
IN THE MID 30S TO LOW 40S. THERMAL TROUGH OF -4 TO -8 DEG C WILL
ARRIVE BY FRI AFTN...WHICH WILL BE MILD COMPARED TO WHAT CONTINUES
TO BE PROGGED FOR SAT.
CONFIDENCE IN PRECIP ENDING MID-MORNING...MEDIUM/HIGH.
CONFIDENCE IN TEMPS...HIGH.
SATURDAY THROUGH WEDNESDAY...
ARCTIC AIR MASS CONTINUES TO BE THE MAIN FEATURE FOR THE UPCOMING
WEEKEND...WITH A SLUG OF TEMPS AT 850MB ARND -16 TO -18 DEG C
ARRIVING SAT. BY SUN THE 500MB TROUGH AXIS WILL BEGIN TO PIVOT
EAST...AS THE SFC RIDGE ARRIVES SAT NGT/SUN ACROSS THE REGION
PROVIDING CONTINUED DRY BUT COLD WEATHER. TEMPS SAT WILL STRUGGLE TO
WARM BEYOND THE UPR 20S...THEN IF WINDS CAN DIMINISH AS ADVERTISED
SAT NGT...TEMPS MAY TUMBLE TO THE SINGLE DIGITS ABOVE ZERO ACROSS
PORTIONS OF THE WESTERN/NORTHWEST CWFA EARLY SUN. CLOSER TO CHICAGO
AND NORTHWEST IN TEMPS WILL REMAIN IN THE LOW/MID TEENS.
THEN FOR DESPITE P-CLOUDY TO MOSTLY SUNNY SKIES...TEMPS SUN WILL
HOLD IN THE MID/UPR 20S.
A SHORTWAVE WILL TRAVERSE THE GREAT LAKES MON...WITH A CHC FOR A
PERIOD OF RAIN/SNOW. YET ANOTHER SFC RIDGE IS PROGGED TO SLIDE SOUTH
INTO THE NORTHERN PLAINS TUE AFTN/EVE...WITH NORTHWEST FLOW
RETURNING TO THE FORECAST AREA. SOME DEGREE OF CONCERN EXISTS FOR
TUE/WED AS GUIDANCE HAS HINTED THAT THE SOUTHERN STREAM VORT MAY
NUDGE FURTHER NORTH. IF THIS TREND CONTINUES...THIS MAY BECOME A
WEATHER SYSTEM OF CONCERN FOR THE HOLIDAY TRAVEL PERIOD NEXT WEEK.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS LOWERING TO IFR THIS EVENING.
* -RA THIS AFTN TAPERING TO -DZ THIS EVENING.
* GUSTY N WINDS OVERNIGHT THROUGH FRIDAY.
* -RA RETURNS EARLY FRIDAY MORNING AND CHANGES OVER TO -RASN BY
MID MORNING...AND ENDS LATE MORNING/EARLY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE IS OVER SOUTHERN ONTARIO WITH ITS COLD FRONT SLOWLY
APPROACHING NORTHERN IL FROM THE NW. THE COLD FRONT STRETCHES FROM
MILWAUKEE TO DUBUQUE WITH LIGHT WINDS JUST AHEAD OF IT. NW TO N
WINDS AND IFR TO LIFR CIGS ARE BEHIND THE FRONT. A WEAK UPPER
LEVEL DISTURBANCE IS ALSO PUSHING INTO SOUTHERN IL AND EXPECTING
THE PRECIP TO OUR SOUTH TO PUSH NORTH AHEAD OF THE DISTURBANCE.
THERE IS STILL A BIT OF UNCERTAINTY ABOUT HOW FAR NORTH THE PRECIP
WILL REACH. KEPT PRECIP AT ALL OF THE EASTERN TERMINALS BUT
DOWNGRADED RFD TO VCSH BECAUSE I THINK -RA WILL REMAIN JUST TO
ITS SOUTH. ATMOSPHERIC MOISTURE REMAINS PLENTIFUL SO CONTINUED -DZ
THROUGH THE EVENING AT ALL LOCATIONS...AND THROUGH THE MORNING AT
RFD.
CIGS HAVE BEEN DIFFICULT AS THE LOWER CIGS OVER IA AND WI HAVE NOT
BUDGED THIS MORNING. THEREFORE TIMING WHEN IF AND WHEN THEY WILL
MOVE INTO ORD HAS BEEN EXTREMELY DIFFICULT. A FEW SOUTHERN WI
SITES HAVE FINALLY REGISTERED IFR CIGS SO USED THAT TO GET THE
TIMING FEATURED IN THE TAFS. THINKING THE LOWER CIGS WILL BE TIED
TO THE PRECIP...AND IFR CIGS ARE ASSOCIATED WITH THE FRONTAL
PASSAGE. CONFIDENCE IS HIGH THAT CIGS WILL FALL...BUT LOW AS FAR
AS WHEN. ALSO KEPT LIFR OUT OF MOST OF THE TAFS DUE TO A LACK OF
CONFIDENCE...BUT LOOKING UPSTREAM THEY ARE STILL POSSIBLE.
WINDS WILL GO LIGHT AND VARIABLE AHEAD OF THE FRONT AND THEN
BECOME NNE ARND 6KT IMMEDIATELY BEHIND THE FRONT. THE GRADIENT
CONTINUES TO TIGHTEN WITH N WINDS 15G20+ KT BY FRIDAY MORNING.
RAIN ALSO RETURNS AHEAD OF THE UPPER LEVEL TROUGH AXIS. COLD AIR
MOVES IN AND PRECIP WILL BECOME A RAIN/SNOW MIX BY MID MORNING.
MAY SEE A BRIEF PERIOD OF SNOW NEAR THE END OF THE PRECIP IN THE
LATE MORNING/EARLY AFTERNOON BUT SOUNDINGS INDICATE ICE CRYSTALS
MAY NOT BE PRESENT SO ALL SNOW WILL BE DIFFICULT. NO ACCUMULATION
IS EXPECTED AT THIS TIME BUT SLICK RUNWAYS ARE LIKELY. VSBY COULD
BE MORE REDUCED THAN INDICATED BUT CIGS SHOULD BE ON A SLOW RISE.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CIG TRENDS...MEDIUM-LOW CONFIDENCE IN TIMING.
* LOW CONFIDENCE IN LIFR CIGS FORMING.
* HIGH CONFIDENCE IN PRECIP THIS EVENING AND TOMORROW...MEDIUM
CONFIDENCE IN TIMING AND CHANGE OVER TO -RASN.
* MEDIUM CONFIDENCE IN VSBY ASSOCIATED WITH PRECIP.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT...DRY/VFR.
* SATURDAY...DRY/VFR. STRONG/GUSTY NORTHWEST WINDS.
* SUNDAY...DRY/VFR.
* MONDAY...CHANCE OF RAIN/SNOW SHOWERS. MVFR POSSIBLE.
* TUESDAY AND WEDNESDAY...DRY/VFR.
&&
.MARINE...
132 PM CST
MAIN MARINE FORECAST CONCERNS INCLUDE PERIODS OF STRONG
NORTH-NORTHWEST WINDS TONIGHT INTO EARLY FRIDAY...AND AGAIN LATE
FRIDAY NIGHT THROUGH SATURDAY. A PERIOD OF GALES APPEARS LIKELY
DURING THE LATE FRIDAY NIGHT THROUGH SATURDAY TIME FRAME. WESTERLY
GALES APPEAR POSSIBLE MONDAY...IN ASSOCIATION WITH ANOTHER LOW AND
APPROACHING COLD FRONT AT THAT TIME.
WEAK LOW PRESSURE OVER THE NORTHERN LAKES WILL PULL AWAY TO THE
NORTHEAST TONIGHT...TRAILING A COLD FRONT ACROSS LAKE MICHIGAN THIS
EVENING. COLD CANADIAN HIGH PRESSURE SPREADING SOUTH ACROSS THE
PLAINS WILL RESULT IN A FAIRLY TIGHT SURFACE PRESSURE GRADIENT
DEVELOPING ACROSS THE WESTERN LAKES...WITH NORTHERLY WINDS
INCREASING TO 30 KT ACROSS LAKE MICHIGAN TONIGHT THROUGH MIDDAY
FRIDAY. WEAK HIGH PRESSURE RIDGING FROM THE EASTERN PERIPHERY OF THE
PLAINS HIGH WILL THEN MOVE ACROSS THE LAKE FRIDAY AFTERNOON ALLOWING
WINDS TO DECREASE/BACK WEST. ANOTHER LOW WILL MOVE ACROSS THE
NORTHERN LAKES LATE FRIDAY HOWEVER...TRAILING ANOTHER COLD FRONT
ACROSS THE LAKE FRIDAY NIGHT. EVEN STRONGER HIGH PRESSURE BUILDING
SOUTH FROM CANADA SATURDAY AND SATURDAY NIGHT BEHIND THIS FRONT WILL
SET UP ANOTHER PERIOD OF STRONG NORTHERLY WINDS...WITH FORECAST
SOUNDINGS CONTINUING TO DEPICT GALES FROM LATE FRIDAY NIGHT THROUGH
SATURDAY EVENING. COLD CANADIAN AIR WILL PRODUCE STEEP LOW LEVEL
LAPSE RATES DURING THIS PERIOD...WITH DEEP MIXING HELPING TO
MAXIMIZE TRANSFER OF WIND MOMENTUM TO THE SURFACE. AIR TEMPERATURES
FALLING INTO THE MID/UPPER 20S MAY PRODUCE SOME FREEZING SPRAY...BUT
WITH WATER TEMPERATURES STILL IN THE MID 40S...CONFIDENCE REMAINS
TOO LOW TO INCLUDE ANY WIDESPREAD FREEZING SPRAY CONDITIONS IN THE
FORECAST AT THIS TIME.
WINDS WILL DECREASE SUNDAY...AS THE NORTHERN PERIPHERY OF THE STRONG
SURFACE HIGH PUSHES EAST ACROSS LAKE MICHIGAN. LONGER RANGE MODEL
RUNS INDICATE ANOTHER LOW WILL MOVE ACROSS THE NORTHERN LAKES SUNDAY
NIGHT AND MONDAY HOWEVER...WITH ANOTHER COLD FRONT MOVING ACROSS THE
LAKE MONDAY NIGHT AS THE ACTIVE PATTERN CONTINUES. FORECAST GUIDANCE
INDICATES A PERIOD OF WEST-SOUTHWEST GALES ARE POSSIBLE SUNDAY NIGHT
INTO MONDAY AHEAD OF THE COLD FRONT.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...4 AM FRIDAY TO 6 AM SATURDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
217 PM CST Thu Nov 21 2013
.DISCUSSION...
ISSUED 205 PM CST Thu Nov 21 2013
Another surge of light rain was tracking northeast into our
area early this afternoon ahead of a weak shortwave over
Kansas. A nearly stationary frontal boundary stretching from
southwest Missouri northeast through eastern Wisconsin will move
little until the aforementioned wave in Kansas pushes to our
northeast tonight. Behind that boundary, Arctic air was spilling
south into the southern Plains with temperatures early this
afternoon ranging from the mid 20s to lower 30s from Kansas south
into the Panhandle of Texas.
SHORT TERM...Tonight through Sunday
Main forecast concern this period will be how quickly the precip
shuts down Friday morning and then after that, its how cold
temperatures will be this weekend. Not too much to argue about as
far as the models are concerned in the short-term as the Arctic
boundary, now to our west, will push through our area tonight with
the colder air mass lagging behind some as the low level flow turns
more north-northeast for a time on Friday, with the bigger push of
much colder air more south than east. But that will change later
tomorrow afternoon and evening as the boundary shifts well off to
our east and cold high pressure settles in from the west. As far
as precip is concerned, forecast soundings to our north continue
to indicate we lose the ice crystals at the cloud top layer by
morning suggesting only a very narrow window of opportunity for
any mix of rain and snow. Just based off the NAM-WRF soundings
it looks more like drizzle than anything else but for now will
hold with the rain-snow mix wording in the grids Friday morning.
Based off the forecast soundings and time height cross sections we
should hold on to the low level moisture/clouds for a time on
Friday. But with the initial push of Arctic air more to our west,
we should see a slow climb in temperatures during the late morning
into the early afternoon hours. The real push of cold air moves
in late in the afternoon and into the overnight hours as the surface
high edges east into the region setting up for a cold and blustery
weekend. A gusty north to northwest wind is expected on Saturdy with
highs struggling to reach 30 in the north and edging into the middle
30s south with wind chills ranging from the teens north to the upper
20s south. With the center of the Arctic air mass pushing right into
central Illinois Sunday morning, look for overnight lows ranging from
around 9 degrees far northwest to the upper teens far southeast. Wind
chills will be in the 5 to 10 degree range. Winds will be quite a bit
lighter on Sunday as Arctic high pressure moves slowly across central
Illinois, but afternoon temperatures will be slow to recover from the
early morning chill with readings mostly in the 20s.
LONG TERM...Monday through Thursday
Split upper flow pattern forecast into early next week with model
differences still seen with respect to how strongly the northern
stream wave amplifies across the Great Lakes starting on Tuesday.
The GFE remains the least amplified, and as a result, does not
bring as much cold air south into our area, while the ECMWF and UK
models were much more amplified with the northern stream, resulting
in another push of Arctic air south into our area by mid-week. The
latest GFS ensemble mean has trended a bit more amplified with the
northern stream by late Tuesday into early Wednesday, before the
flow quickly deamplifies after Wednesday. We have seen this type of
scenario before with the models this fall season with the ECMWF usually
the most aggressive with the push of cold air south, while the GFS
has been quite a bit more conservative with respect to how deep the
upper trofs become off to our east. So far, the GFS has done a better
job with respect to verifying the amount of cold air spilling south
into our area.
As far as precip is concerned, with a return flow setting up across
the region on Monday. The combination of moisture from the southwest
cutoff low and a northern stream wave and associated frontal boundary
approaching from the northwest, warrants at least a slight chance for
light snow in the morning, and the possibility for a light snow and
rain mix in the afternoon. After that, we start to see some significant
differences with the models with again, the ECMWF more aggressive with
the northern stream and actually shows a phases soultion with the
southwest cutoff low by Tuesday of next week, opening up the cold air
flood gates once more. The GFS is quite a bit less amplified with
no phasing indicated late Tuesday into Wednesday. For now, will not
make any significant changes to the extended with temperatures still
expected to average well below normal thru the week with the most
significant threat for widespread precip over the lower Mississippi
valley, and then up the East coast late Tuesday night through
Thanksgiving day.
Smith
&&
.AVIATION...
ISSUED 1144 AM CST Thu Nov 21 2013
An area of rain is currently pushing into central Illinois from
the southwest and will overspread the entire area over the next
1 to 2 hours. While VFR ceilings are initially present as the rain
first begins, upstream obs and latest HRRR data both suggest
ceilings dropping to IFR later this afternoon into tonight.
Steadiest rains and lowest ceilings will generally be focused
along and south of a KIJX to KBMI line, meaning the period of IFR
ceilings will be a bit shorter at KPIA than the other central
Illinois terminals. As a cold front pushes eastward across the
state overnight, ceilings will climb back into the MVFR category
after 10z at KPIA, then after 13z further east at KCMI. Winds will
initially be southerly this afternoon, then will go light/variable
this evening. Once front passes, strong northwesterly winds
gusting over 20kt will develop by Friday morning.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1224 PM CST THU NOV 21 2013
.DISCUSSION...
303 AM CST
PERIODS OF PRECIP AND FALLING TEMPS WILL BE THE FOCUS FOR THE NEXT
SEVERAL DAYS. WATER VAPOR IMAGERY SHOWS VERY BROAD TROUGHING OVER
THE CONUS WITH THE LOCAL AREA UNDERNEATH THE BELT OF SOUTHWESTERLY
FLOW EAST OF THE TROUGH AXIS. SEVERAL WAVES CONTINUE TO TRAVERSE
THIS FLOW...ONE OF WHICH HAS DEPARTED TO THE NORTHEAST WITH ANOTHER
MOVING ACROSS SOUTHERN ILLINOIS AND A THIRD MOVING ACROSS EASTERN
KANSAS/OKLAHOMA AND SOUTHWEST MISSOURI. ON THE LARGER SCALE...A LOW
CIRCULATION OVER CALIFORNIA/NEVADA IS IN THE PROCESS OF CUTTING OFF
FROM A STRONGER STREAM OVER BRITISH COLUMBIA. AT THE SURFACE...AN
EXPANSIVE AREA OF HIGH PRESSURE IS OVER NORTHERN NEW ENGLAND WITH A
RIDGE AXIS EXTENDING DOWN TO THE FLORIDA PANHANDLE. AN INVERTED
TROUGH AXIS IS STRETCHED FROM THE SOUTHERN PLAINS TO THE ARROWHEAD
OF MINNESOTA WITH A 1040 MB HIGH STRENGTHENING AS IT SPREADS INTO
THE NORTHERN HIGH PLAINS.
TODAY THROUGH FRIDAY...THE SURFACE INVERTED TROUGH CURRENTLY ACROSS
IOWA WILL BE SHIFTING EASTWARD TODAY AND SHOULD BE EAST OF THE CWA
LATER TONIGHT. THE TROUGH WILL REMAIN FAIRLY WEAK AS IT AFFECTS THE
AREA GIVEN THAT PHASING BETWEEN THE AMPLIFYING UPPER TROUGH MOVING
INTO THE NORTHERN PLAINS AND THE WAVES TRAVERSING THE SOUTHWESTERLY
FLOW NOW OVER THE LOCAL AREA IS NOT MATERIALIZING. THE FOCUS FOR
PRECIPITATION WILL BE MORE CLOSELY TIED TO THE AFOREMENTIONED
SHORTWAVES UPSTREAM OF THE AREA AND A STRENGTHENING MID LEVEL
BAROCLINIC ZONE. RADAR MOSAIC SHOWS A CORRIDOR OF RAIN SHOWERS FROM
SOUTHERN ILLINOIS NORTHEAST TO LAKE ERIE TIED TO THE DEPARTING WAVE
TO THE EAST AND THE WAVE MOVING ACROSS SOUTHERN ILLINOIS. THE TAIL
END OF THIS WAVE MAY HELP TO PUSH SHOWER ACTIVITY INTO THE FAR
SOUTHEAST CWA THIS MORNING. AS THE KS/OK/MO WAVE WORKS IN LATER THIS
AFTERNOON THE PRECIP SHIELD LOOKS TO SPREAD ACROSS THE REST OF THE
AREA WHICH WILL BE ABOUT THE TIME THAT THE SURFACE TROUGH AXIS
CROSSES THE AREA. EXPECT THE BULK OF THE PRECIP TO FALL ACROSS THE
SOUTHEAST HALF TO TWO-THIRDS OF THE AREA THROUGH THIS EVENING...WITH
THE MOST WIDESPREAD COVERAGE LIKELY OCCURRING LATE THIS AFTERNOON
THROUGH THE EVENING. ONCE THE LAST OF THE MAIN WAVES DEPARTS THIS
EVENING PRECIP COVERAGE BECOMES MORE OF A CHALLENGE BUT WILL
PROBABLY DIMINISH LATE THIS EVENING OR EARLY TONIGHT. THE UPPER
TROUGH NOW WORKING INTO THE NORTHERN PLAINS WILL BE WORKING EAST
PUSHING COLDER AIR SOUTHEAST WITH IT FRIDAY MORNING. THE COLD
ADVECTION MAY BE ABLE TO WRING OUT SOME ADDITIONAL SHOWERS AS IT
SPREADS IN FRIDAY WITH RESIDUAL MOISTURE STILL IN PLACE. FORCING AND
MOISTURE REALLY DROP OFF DURING THE AFTERNOON OR EVEN BY AFTERNOON
SO WILL HASTEN THE DECREASE IN POPS WITH MOST IF NOT ALL AREAS DRY
BY AFTERNOON. WITH THE FALLING MID LEVEL TEMPS...ANY RAIN ACTIVITY
WILL TRY TO MIX WITH SNOW AS THE COLD AIR ARRIVES BUT IT MAY BE THAT
PRECIP ENDS BEFORE THIS REALLY HAS A CHANCE TO OCCUR. HIGHS TODAY
WILL BE IN THE UPPER 40S TO NEAR 50 WITH HIGHS FRIDAY LIKELY
OCCURRING DURING THE MORNING WITH UPPER 30S NORTHWEST AND MID 40S
SOUTHEAST...WITH FALLING TEMPS DURING THE AFTERNOON.
SATURDAY AND SUNDAY...ANOTHER WAVE WILL BE MOVING DOWN THE WESTERN
PORTION OF THE UPPER TROUGH HELPING TO AMPLIFY IT AND BRINGING A
SECOND PUSH OF COLD AIR SATURDAY MORNING. A 1042+MB HIGH WILL BE
BUILDING INTO THE PLAINS WITH BREEZY NORTHWEST WINDS DEVELOPING TO
ITS EAST ACROSS THE LOCAL AREA. WITH H85 TEMPS FALLING TO AROUND
-16C SURFACE TEMPS WILL HAVE A HARD TIME WARMING FROM THEIR MORNING
READINGS...WITH HIGHS EXPECTED TO RANGE FROM THE MID/UPPER 20S NORTH
TO AROUND 30/LOWER 30S SOUTH. THE CENTER OF THE HIGH WILL BE
CROSSING CENTRAL ILLINOIS SUNDAY WITH THE RIDGE AXIS CROSSING THE
CWA. THIS WILL ALLOW FOR LITTLE MIXING FOR MOST OF THE DAY THOUGH A
LIGHT SOUTHWEST WIND MAY SET UP LATER IN THE DAY. H85 TEMPS WILL BE
WARNING TO AROUND -6 TO -8C BY LATE DAY AS THE UPPER TROUGH AXIS
MOVES TO THE EAST AND LOW AMPLITUDE UPPER RIDGING BRINGS WARM
ADVECTION BACK TO THE MID AND UPPER MISSISSIPPI RIVER VALLEY AND
WESTERN GREAT LAKES. WILL CONTINUE WITH HIGHS MAINLY IN THE MID 20S
DESPITE THE WARMING ALOFT DUE TO THE WEAK MIXING AND NEED TO REBOUND
FROM MORNING READINGS IN THE TEENS.
MONDAY THROUGH WEDNESDAY...A TROUGH WILL MOVE SOUTHEAST ACROSS
CENTRAL CANADA SHUNTING THE UPPER RIDGING TO THE EAST SUNDAY NIGHT
AND MONDAY WITH THE PASSAGE OF THE TROUGH AXIS POSSIBLY BRINGING
SOME SNOW SHOWERS DURING THE DAY MONDAY. A SOUTHWEST WIND AND H85
TEMPS AROUND -3 OR -4C SHOULD ALLOW TEMPS TO RECOVER INTO THE MID
30S. GUIDANCE IS AT ODDS FROM TUESDAY ONWARD WITH THE HANDLING OF
THE CUTOFF LOW /THE ONE CUTTING OFF OVER SOUTHERN CALIFORNIA TODAY
AND TOMORROW/ AND POTENTIAL PHASING WITH THE NORTHERN STREAM TROUGH.
CONFIDENCE IS LOW IN WHETHER TEMPS REMAIN NEAR MONDAYS VALUES OR
COOL OFF ONCE AGAIN THANKS TO DISCREPANCIES ON WHETHER A SECOND
TROUGH TRAILS THE MONDAY TROUGH BRINGING ANOTHER PUSH OF COLD AIR OR
NOT.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS LOWERING TO IFR THIS EVENING.
* -RA THIS AFTN TAPERING TO -DZ THIS EVENING.
* GUSTY N WINDS OVERNIGHT THROUGH FRIDAY.
* -RA RETURNS EARLY FRIDAY MORNING AND CHANGES OVER TO -RASN BY
MID MORNING...AND ENDS LATE MORNING/EARLY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE IS OVER SOUTHERN ONTARIO WITH ITS COLD FRONT SLOWLY
APPROACHING NORTHERN IL FROM THE NW. THE COLD FRONT STRETCHES FROM
MILWAUKEE TO DUBUQUE WITH LIGHT WINDS JUST AHEAD OF IT. NW TO N
WINDS AND IFR TO LIFR CIGS ARE BEHIND THE FRONT. A WEAK UPPER
LEVEL DISTURBANCE IS ALSO PUSHING INTO SOUTHERN IL AND EXPECTING
THE PRECIP TO OUR SOUTH TO PUSH NORTH AHEAD OF THE DISTURBANCE.
THERE IS STILL A BIT OF UNCERTAINTY ABOUT HOW FAR NORTH THE PRECIP
WILL REACH. KEPT PRECIP AT ALL OF THE EASTERN TERMINALS BUT
DOWNGRADED RFD TO VCSH BECAUSE I THINK -RA WILL REMAIN JUST TO
ITS SOUTH. ATMOSPHERIC MOISTURE REMAINS PLENTIFUL SO CONTINUED -DZ
THROUGH THE EVENING AT ALL LOCATIONS...AND THROUGH THE MORNING AT
RFD.
CIGS HAVE BEEN DIFFICULT AS THE LOWER CIGS OVER IA AND WI HAVE NOT
BUDGED THIS MORNING. THEREFORE TIMING WHEN IF AND WHEN THEY WILL
MOVE INTO ORD HAS BEEN EXTREMELY DIFFICULT. A FEW SOUTHERN WI
SITES HAVE FINALLY REGISTERED IFR CIGS SO USED THAT TO GET THE
TIMING FEATURED IN THE TAFS. THINKING THE LOWER CIGS WILL BE TIED
TO THE PRECIP...AND IFR CIGS ARE ASSOCIATED WITH THE FRONTAL
PASSAGE. CONFIDENCE IS HIGH THAT CIGS WILL FALL...BUT LOW AS FAR
AS WHEN. ALSO KEPT LIFR OUT OF MOST OF THE TAFS DUE TO A LACK OF
CONFIDENCE...BUT LOOKING UPSTREAM THEY ARE STILL POSSIBLE.
WINDS WILL GO LIGHT AND VARIABLE AHEAD OF THE FRONT AND THEN
BECOME NNE ARND 6KT IMMEDIATELY BEHIND THE FRONT. THE GRADIENT
CONTINUES TO TIGHTEN WITH N WINDS 15G20+ KT BY FRIDAY MORNING.
RAIN ALSO RETURNS AHEAD OF THE UPPER LEVEL TROUGH AXIS. COLD AIR
MOVES IN AND PRECIP WILL BECOME A RAIN/SNOW MIX BY MID MORNING.
MAY SEE A BRIEF PERIOD OF SNOW NEAR THE END OF THE PRECIP IN THE
LATE MORNING/EARLY AFTERNOON BUT SOUNDINGS INDICATE ICE CRYSTALS
MAY NOT BE PRESENT SO ALL SNOW WILL BE DIFFICULT. NO ACCUMULATION
IS EXPECTED AT THIS TIME BUT SLICK RUNWAYS ARE LIKELY. VSBY COULD
BE MORE REDUCED THAN INDICATED BUT CIGS SHOULD BE ON A SLOW RISE.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CIG TRENDS...MEDIUM-LOW CONFIDENCE IN TIMING.
* LOW CONFIDENCE IN LIFR CIGS FORMING.
* HIGH CONFIDENCE IN PRECIP THIS EVENING AND TOMORROW...MEDIUM
CONFIDENCE IN TIMING AND CHANGE OVER TO -RASN.
* MEDIUM CONFIDENCE IN VSBY ASSOCIATED WITH PRECIP.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT...DRY/VFR.
* SATURDAY...DRY/VFR. STRONG/GUSTY NORTHWEST WINDS.
* SUNDAY...DRY/VFR.
* MONDAY...CHANCE OF RAIN/SNOW SHOWERS. MVFR POSSIBLE.
* TUESDAY AND WEDNESDAY...DRY/VFR.
&&
.MARINE...
318 AM...A COLD FRONT WILL MOVE SOUTH ACROSS THE NORTHERN PART OF
LAKE MICHIGAN THIS EVENING AND THEN MOVE SOUTH OF THE LAKE BY
FRIDAY MORNING. WINDS WILL SHIFT NORTHERLY BEHIND THE FRONT AND
INCREASE TO 30KTS. THERE APPEARS TO BE A SHORT PERIOD IMMEDIATELY
BEHIND THE FRONT WHERE GUSTS COULD REACH LOW END GALES. AT THIS
POINT...NOT SURE HOW LONG THAT PERIOD MAY LAST AND HAVE OPTED TO
INCLUDE JUST GALE GUST WORDING WITH THIS FORECAST. STRONG HIGH
PRESSURE WILL SURGE SOUTH ACROSS THE PLAINS TONIGHT INTO FRIDAY
WHILE ANOTHER STRONGER HIGH SPREADS ACROSS SOUTH CENTRAL CANADA.
IN BETWEEN THESE TWO SYSTEMS...A TROUGH OF LOWER PRESSURE WILL
MOVE ACROSS THE NORTHERN LAKES LATE FRIDAY NIGHT AND SLOWLY DEEPEN
AS IT MOVES ACROSS THE EASTERN LAKE SATURDAY. NORTHERLY WINDS WILL
SLOWLY DIMINISH FRIDAY AFTERNOON...THEN SHIFT WESTERLY...PERHAPS
BRIEFLY SOUTHWESTERLY...AHEAD OF THIS TROUGH. AS IT SHIFTS EAST...
THE TWO HIGH PRESSURE SYSTEMS WILL MERGE INTO ONE SPRAWLING HIGH
OVER THE PLAINS FRIDAY NIGHT INTO SATURDAY. THE GRADIENT WILL
TIGHTEN BEHIND THE DEPARTING TROUGH AND THIS STRONG HIGH. WINDS
WILL SHIFT NORTHWEST FRIDAY NIGHT AND INCREASE TO GALES BY
SATURDAY MORNING WITH A PERIOD OF 40KTS IN THE MORNING ESPECIALLY
ACROSS THE NORTH HALF. THE WINDS WILL SLOWLY DIMINISH BY SATURDAY
EVENING AND CONTINUE DIMINISHING SATURDAY NIGHT. AIR TEMPERATURES
ARE EXPECTED TO FALL INTO THE MID TO UPPER 20S BY SATURDAY EVENING
AND LIKELY REMAIN IN THE LOWER TO MID 20S FOR MUCH OF SATURDAY
NIGHT. ITS POSSIBLE THERE COULD BE SOME FREEZING SPRAY BUT WITH
WATER TEMPERATURES STILL IN THE MID 40S...CONFIDENCE IS TOO LOW TO
INCLUDE ANY MENTION WITH THIS FORECAST.
THE HIGH WILL SLOWLY WEAKEN AS IT MOVES SOUTHEAST TO THE OHIO
VALLEY SUNDAY AND TO THE MID ATLANTIC MONDAY. A WEAKER RIDGE
AXIS EXTENDING NORTH WILL CROSS LAKE MICHIGAN SUNDAY AFTERNOON
SHIFTING WINDS TO THE SOUTHWEST. ANOTHER LOW PRESSURE WILL MOVE
ACROSS SOUTH CENTRAL ONTARIO AND THE NORTHERN LAKES SUNDAY NIGHT
INTO MONDAY. THE GRADIENT WILL TIGHTEN QUICKLY SUNDAY EVENING
WITH SOUTHWEST GALES DEVELOPING SUNDAY NIGHT...TURNING WESTERLY
MONDAY WITH THE GALES DIMINISHING MONDAY AFTERNOON INTO MONDAY
EVENING. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...4 AM FRIDAY TO 6 AM SATURDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1144 AM CST Thu Nov 21 2013
.DISCUSSION...
ISSUED 1041 AM CST Thu Nov 21 2013
Nearly stationary frontal boundary extending from far northern
Illinois southwestward to the Texas panhandle will serve as the
primary focusing mechanism for rain today and tonight. Short-wave
trough evident on 16z/10am water vapor imagery over Kansas/Oklahoma
will track along the boundary this afternoon, providing enhanced
synoptic lift. As a result, expect rain to become widespread across
all of central and southeast Illinois as the day progresses.
Upstream obs have shown mainly rain: however, a few lightning
strikes were observed earlier in southwest Missouri. Will
therefore maintain isolated thunder wording across the southern
half of the KILX this afternoon. Despite a light southerly wind,
extensive cloud cover and precip will keep high temperatures
mainly in the lower 50s. Forecast update will be issued shortly.
Barnes
&&
.AVIATION...
ISSUED 1144 AM CST Thu Nov 21 2013
An area of rain is currently pushing into central Illinois from
the southwest and will overspread the entire area over the next
1 to 2 hours. While VFR ceilings are initially present as the rain
first begins, upstream obs and latest HRRR data both suggest
ceilings dropping to IFR later this afternoon into tonight.
Steadiest rains and lowest ceilings will generally be focused
along and south of a KIJX to KBMI line, meaning the period of IFR
ceilings will be a bit shorter at KPIA than the other central
Illinois terminals. As a cold front pushes eastward across the
state overnight, ceilings will climb back into the MVFR category
after 10z at KPIA, then after 13z further east at KCMI. Winds will
initially be southerly this afternoon, then will go light/variable
this evening. Once front passes, strong northwesterly winds
gusting over 20kt will develop by Friday morning.
Barnes
&&
.PREV DISCUSSION...
ISSUED 228 AM CST Thu Nov 21 2013
Showers have been scattered over about the southeast half of the
forecast area the last few hours, with regional radar imagery at 2
am showing a sizable break in the rain across much of Missouri.
Latest surface map showed low pressure over the Texas panhandle,
with a frontal boundary arcing northeast to link up with a cold
front across central Minnesota and western Iowa. Water vapor
imagery over the last few hours has shown the split upper flow
taking better hold as a trough digs across California, and another
trough over eastern Saskatchewan in the northern stream. This
split flow will play a big part in the arrival of a couple shots
of very cold air over the next week.
SHORT TERM...Today through Friday:
Cold front will get a healthy kick eastward later today, as the
two upper streams interact somewhat over the Plains. Another surge
of moisture will stream northeast into the forecast area, and will
maintain categorical rain chances over about the southeast 2/3 of
the CWA by afternoon. Cannot rule out a rumble or two of thunder,
but that should be few and far between. The front should push
through the CWA tonight, with the brunt of the precipitation more
toward the Ohio River by sunrise, but am expecting some post-
frontal rain to linger over the southeast at least into early
afternoon.
LONG TERM...Saturday through Wednesday:
Arctic air will plunge over the Great Lakes region this weekend,
bringing the coldest air of the season to central Illinois. 850 mb
temps of -14C expected Saturday night. Northwest CWA will struggle
to reach freezing Saturday, and much of the area will only be
around 30 for Sunday. A fairly stiff northwest wind is expected as
strong Canadian high pressure moves in, resulting in wind chills
in the single digits by Sunday morning.
The high pressure will exit to our southeast Sunday night as the
next storm system approaches from the northern Plains. Longer
range models remain agreeable with a storm system developing over
the Gulf in response to the large cutoff low in the southern
stream finally ejecting eastward, and that will prevent meaningful
moisture return to aid the northern front. Will see some light
snow with this front on Monday, perhaps mixing with some afternoon
rain, but only a dusting of accumulation expected.
Longer range models experiencing some timing differences in
how far to plunge the next Arctic outbreak southward. The GFS
keeps us relatively mild with the ECMWF remaining much more
aggressive, with 850 mb temperatures ranging from zero to -15C
by midweek. The discrepancy is because the GFS is much slower with
the progression of the closed low over the southeast U.S., helping
to bottle the cold air mass much further north. Have not made much
change to the forecast at this point, which had been trending toward
the colder solution. However, both are in agreement with dry
weather for the pre-Thanksgiving travel rush in the immediate area.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
303 PM CST Thu Nov 21 2013
.SHORT TERM...(This Evening through Friday)
Issued at 256 PM CST THU NOV 21 2013
.Synopsis...
Water vapor imagery shows a shortwave trough over the northern
plains propagating east towards the great lakes, while energy
begins to cut off over central CA. At the surface, a strong cold
front has pushed through the entire forecast area with
temperatures continuing to fall in response to strong cold air
advection.
.Short Term... (Tonight)
For tonight the forcing for continued precipitation looks to be
mainly driven by mid level frontogenesis. The NAM and RAP progs
show weakening isentropic upglide early in the evening as the 850
front continues to push south. Then by the late evening and
overnight mid level drying near the better mid level
frontogenetical forcing suggests that precip could come to an end
since there is no lift within the low level cloud from isentropic
features for light freezing drizzle. With this in mind have
trended POPs down for most areas overnight. The latest
HRRR/RAP13/NAM12 continue to show this band of precip currently
from Minneapolis to Hiawatha, associated with some mid level
frontogenesis, to lift northeast into northwest MO. Therefore have
some likely pops for the early evening across far northeast KS.
Otherwise the forecast will only have some chance pops through the
rest of tonight. Did not feel confident enough to lower pops any
further since there will be some mid level frontogenesis through
the night. Also will not make any major changes to the advisory
other than to end it earlier in the day Friday. It is one of those
situations that with the advisory already out it doesn`t make
sense to cancel it early since there remains the potential for
some light frozen precip with reports of slick roads coming in.
Since forcing is weak and moisture will continue to lessen through
the night, additional precipitation is anticipated to be on the
light side with accumulations generally around a tenth of an inch in
water equivalent. The mid level drying will also make it difficult
for snow to occur since the dendritic growth zone is not expected to
be saturated. Because of this there shouldn`t be any ice crystals
for snow. So think freezing rain and sleet will be the primary
precip type through the night if precip does fall. Continued cold
air advection should cause temperatures to fall into the teens and
mid 20s for the forecast area by sunrise Friday.
.LONG TERM...(Friday Night through Thursday)
Issued at 256 PM CST THU NOV 21 2013
Friday...Becomes a race with the incoming drier air as to how much
precipitation can fall on Friday as high pressure continues to surge
into the southern plains through the day. Back to the west an upper
low advances into Baja, lifting a lobe of moisture into southern
Kansas in the mid levels. Frontogenesis gets some further
enhancement from northern trof dropping energy into the area mid to
late day. Isentropic charts indicate downglide in the lower levels,
with 700mb chart showing some broad convergence in the wind field
through the noon hour. With lack of strong lift and incoming drier
air have pulled back on precip chances and amounts but not ready to
remove entirely for the southern counties just yet. Enough
consensus in incoming dry air from north to end the advisory earlier
for generally the I70 counties, but will hang onto it through noon
for those south of I70. Temperature profiles are finally cold enough
for all snow along the northern edge but hold onto a weak warm nose
across the SE and will keep a S/IP mix for these areas. Went colder
on both highs and lows given current reflection in observations with
highs upper 20s to near freezing and dropping overnight into the
upper teens.
Saturday and Sunday... Continue to go on the cool side of guidance
on Saturday with high pressure still on the move to the south. Have
highs near freezing and lows in the lower to middle teens. Incoming
clouds from the southwest on Sunday plus a return to southerly
surface low on the wrn side of the high should bring highs back into
the middle 30s on Sunday.
Monday: An upper level trough forming out of the Four Corners region
will propagate to the east. The 12Z ECMWF/GFS are in reasonable
agreement pertaining to the location of the trough. A jet streak of
up to 100kt winds associated with this trough should eject
additional moisture into Oklahoma and Kansas. Southerly winds in
this region should help support moisture transfer over eastern
Kansas. This additional moisture, along with freezing temperatures,
could support light snow over eastern Kansas.
By Tuesday, the trough should pivot to the south due to a ridging
stream wave over the western CONUS. The trough should stay further
south into Texas and Oklahoma. Winds shift from southerly to
northerly as the trough moves south. The ridging pattern over the
western CONUS will translate towards the east by Wednesday, bringing
quiet weather to the region. Lows will be in the 20s overnight and
highs will be in the upper 30s/lower 40s for the rest of the week.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1121 AM CST THU NOV 21 2013
Think CIGS and VSBY could bounce around between IFR and MVFR
through this evening. Forcing for precip looks to be weak such
that precip intensity should remain light through the evening so
do not anticipate LIFR or VLIFR conditions at this time. Think
precip type is likely to remain FZRAPL. See the updated discussion
for further details. With the quicker frontal timing and cold air
moving south, will start freezing precip a little sooner at the
terminals. Also with dry air working in overnight from the north,
will bring an end to precip sooner as well which should also allow
VSBY to improve. Models show CIGS gradually improving by mid
morning Friday.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 6 AM CST Friday FOR KSZ008>012-
020>024-026-034>036-038-039.
WINTER WEATHER ADVISORY from 6 PM this evening to 6 AM CST
Friday FOR KSZ040.
WINTER WEATHER ADVISORY until Noon CST Friday FOR KSZ037.
WINTER WEATHER ADVISORY from 6 PM this evening to Noon CST
Friday FOR KSZ054>056-058-059.
&&
$$
SHORT TERM...67/Wolters
LONG TERM...67/JTS
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1121 AM CST Thu Nov 21 2013
...AVIATION UPDATE...
.UPDATE...
Issued at 1034 AM CST THU NOV 21 2013
Updated the forecast to go with a quicker trend in bringing the
cold air south behind the front. Also tweaked pops for this
afternoon and tonight to follow latest trends in short term model
trends.
Forcing...
NAM and RAP progs continue to show isentropic lift and weak moisture
advection up over the shallow layer of cold air. In addition the
higher resolution models suggest a band of precip forming by mid
afternoon across northern KS in response to a band of mid level
frontogenesis. However by the early evening the low level
isentropic lift dissipates along with any weak moisture advection and
the layer where the stronger frontogenetical forcing starts to dry
out. because of this have trended pops down for the late night
hours.
Precip type...
Model forecast soundings do not have much saturation in the
dendritic growth zone for ice crystals. The one exception may be
across far north central KS during the late afternoon where the
cold air may be deep enough with some saturation in the dendritic
growth zone for a brief period of snow. Otherwise the forecast
anticipates mainly light freezing rain as surface temps continue
to fall through the day. Sleet should become mixed in with any
freezing rain as the shallow cold air approaches -10C allowing for
any supper cooled water to freeze before hitting the ground.
&&
.SHORT TERM...(Today and Tonight)
Issued at 517 AM CST THU NOV 21 2013
The main focus for the short term is on the approaching system that
will bring a wintry mix of precipitation to the forecast area. Early
this morning, another embedded shortwave skimmed across southern
Kansas. The combination of an increasing mid-level jet advecting more
moisture into the region and decent isentropic lift in the 300K-315K
layer resulted in the development of scattered showers and a few
isolated thunderstorms across northern Oklahoma and southern Kansas
early this morning. At 11z, this activity was beginning to lift
northward into central Kansas. This precipitation will continue to
spread across much of the outlook area through the day with
scattered areas of precipitation persisting through the evening and
overnight hours.
The main focus with this activity will be precipitation type as
plummeting temperatures will result in the development of a wintry
mix. Early this morning, a mid-level trough continued to dig
southward across Canada and into the Northern Plains, ultimately
helping to push a cold front into the region. As of 11z, this cold
front had already advanced into north central Kansas with regional
observation sites showing breezy northerly winds behind this front
advecting much colder air into the area. In fact, temperatures had
already dropped into the mid 30s in north central Kansas with
readings in the teens and 20s across much of Nebraska. This cold air
will overspread the forecast area today as the cold front tracks
southeast of the area by this afternoon. As a result, went with a
non-diurnal trend for temperatures today as most locations will see
temperatures steadily dropping through the day. High temperatures
will range from the lower 50s over east central Kansas down into the
middle 30s over north central Kansas. These plummeting temperatures
combined with scattered precipitation today through tonight will
result in a mixed bag of precipitation types. Over eastern Kansas,
temperatures should stay above freezing through the daytime hours
and keep precipitation in the form of light rain through this
afternoon and into early this evening. However, across north central
Kansas, temperatures are expected to drop into the middle 20s to
middle 30s through the day. Model soundings have consistently been
showing a prevailing warm nose of roughly +3C to +5C this afternoon
in that region, with saturation diminishing within the dendritic
growth zone. These features combined with dropping surface
temperatures will result in areas of light freezing rain, freezing
drizzle and/or sleet developing late this morning through this
afternoon across locations generally along and west of a line
stretching from Marysville to Manhattan and Council Grove. As
temperatures continue to plummet across eastern Kansas, expect to
see this mix of light freezing rain/drizzle and sleet shift into
northeast Kansas tonight. Locations generally southeast of I-35
likely won`t see this transition from rain to mixed wintry precip
until around midnight. Across north central Kansas, model soundings
show the warm nose diminishing this evening, so the loss of this
warmer air aloft combined with dropping surface temperatures will
result in the precipitation type transitioning over toward a mix of
sleet and snow before eventually becoming all snow by around 9pm
over far north central Kansas and closer to midnight over much of
northern and north central Kansas. Overnight low temperatures will
ultimately bottom out in the upper teens to upper 20s from northwest
to southeast over the CWA.
While several wintry precipitation types are expected with this
system, the one thing it lacks is abundant moisture. As a result,
much of the region will likely see a prolonged period of just light
precipitation. Snow accumulations over north central Kansas are
expected to be less than one inch and less than one-half inch over
east central Kansas. Ice accumulations are also expected to be light
at less than one-tenth inch. However, this light precipitation could
still be enough to cause slick road conditions across the region,
especially on bridges and overpasses. As a result, have extended the
Winter Weather Advisory to cover the entire outlook area by tonight.
One very noteworthy trend with the 00z model runs is the speed at
which the drier air moves into the area as surface high pressure
advances southward along the lee-side of the Rockies. The
GFS/ECMWF/GEM are all in agreement in having this precipitation
diminishing over north central Kansas after 06z with much of the
forecast area shown as being dry by around 12z Friday. However, both
the 00z and 06z runs of the NAM are much slower with the progression
of the dry air and keep precipitation across much of the CWA into
Friday morning. Considering the combination of these model trends
and current observations further north of the CWA, have trended more
with the progressive dry-air solutions of the GFS/ECMWF/GEM and thus
have trended downward with the PoPs after midnight, especially
across north central Kansas.
.LONG TERM...(Friday through Wednesday)
Issued at 517 AM CST THU NOV 21 2013
Southwest to zonal flow will be present across the Central Plains on
Friday. A northern Plains upper trough with energy extending south
into the Central Plains will move east into the Great Lakes and
Ontario Province by 00Z Saturday. The cold air depth increases
through the day on Friday. Drier air will move south into Kansas by
afternoon, effectively ending light snow in the northern counties.
Forecast soundings from models show a wintry mix as dry air aloft
will keep the dendritic snow growth portion of the sounding
unsaturated. So expect to see some periods of freezing drizzle,
freezing rain and sleet will all be possible at one time or another.
The GFS and ECMWF are much drier than the NAM with the moisture
profiles. Have gone with a compromise with them for this forecast.
With drier air advecting into northern Kansas in the afternoon
expect precipitation along the Nebraska border to come to an end
while light precipitation is expected to continue across east
central Kansas into the afternoon hours. Temperatures will be near
or below freezing through the day. Models show the the warm nose
around 850 MB to 800 MB going away by late afternoon in east central
Kansas and could see a brief period of light snow before sunset.
Cold arctic air will spread eastward across eastern Kansas with lows
dropping down into the teens to lower 20s.
For the weekend an upper level low in the southwest begins to move
out into the Southern Plains early next week. This may bring a
chance of the light snow or sleet into northeast and east central
Kansas Sunday night. The Upper low is forecast to move across Texas
then into the Gulf Coast States by mid week. With the low passing
well south it will keep any precipitation well to the south. Highs
int he 30s and 40s will be common with lows in the 20s Sunday
through Wednesday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1121 AM CST THU NOV 21 2013
Think CIGS and VSBY could bounce around between IFR and MVFR
through this evening. Forcing for precip looks to be weak such
that precip intensity should remain light through the evening so
do not anticipate LIFR or VLIFR conditions at this time. Think
precip type is likely to remain FZRAPL. See the updated discussion
for further details. With the quicker frontal timing and cold air
moving south, will start freezing precip a little sooner at the
terminals. Also with dry air working in overnight from the north,
will bring an end to precip sooner as well which should also allow
VSBY to improve. Models show CIGS gradually improving by mid
morning Friday.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 9 PM this evening to 9 AM CST
Friday FOR KSZ011-012-023-024-026.
WINTER WEATHER ADVISORY until 9 AM CST Friday FOR KSZ008>010-
020>022-034.
WINTER WEATHER ADVISORY from 9 PM this evening to 3 PM CST
Friday FOR KSZ037>040-054>056-058-059.
WINTER WEATHER ADVISORY until 3 PM CST Friday FOR KSZ035-036.
&&
$$
UPDATE...Wolters
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1035 AM CST Thu Nov 21 2013
.UPDATE...
Issued at 1034 AM CST THU NOV 21 2013
Updated the forecast to go with a quicker trend in bringing the
cold air south behind the front. Also tweaked pops for this
afternoon and tonight to follow latest trends in short term model
trends.
Forcing...
NAM and RAP progs continue to show isentropic lift and weak moisture
advection up over the shallow layer of cold air. In addition the
higher resolution models suggest a band of precip forming by mid
afternoon across northern KS in response to a band of mid level
frontogenesis. However by the early evening the low level
isentropic lift dissipates along with any weak moisture advection and
the layer where the stronger frontogenetical forcing starts to dry
out. because of this have trended pops down for the late night
hours.
Precip type...
Model forecast soundings do not have much saturation in the
dendritic growth zone for ice crystals. The one exception may be
across far north central KS during the late afternoon where the
cold air may be deep enough with some saturation in the dendritic
growth zone for a brief period of snow. Otherwise the forecast
anticipates mainly light freezing rain as surface temps continue
to fall through the day. Sleet should become mixed in with any
freezing rain as the shallow cold air approaches -10C allowing for
any supper cooled water to freeze before hitting the ground.
&&
.SHORT TERM...(Today and Tonight)
Issued at 517 AM CST THU NOV 21 2013
The main focus for the short term is on the approaching system that
will bring a wintry mix of precipitation to the forecast area. Early
this morning, another embedded shortwave skimmed across southern
Kansas. The combination of an increasing mid-level jet advecting more
moisture into the region and decent isentropic lift in the 300K-315K
layer resulted in the development of scattered showers and a few
isolated thunderstorms across northern Oklahoma and southern Kansas
early this morning. At 11z, this activity was beginning to lift
northward into central Kansas. This precipitation will continue to
spread across much of the outlook area through the day with
scattered areas of precipitation persisting through the evening and
overnight hours.
The main focus with this activity will be precipitation type as
plummeting temperatures will result in the development of a wintry
mix. Early this morning, a mid-level trough continued to dig
southward across Canada and into the Northern Plains, ultimately
helping to push a cold front into the region. As of 11z, this cold
front had already advanced into north central Kansas with regional
observation sites showing breezy northerly winds behind this front
advecting much colder air into the area. In fact, temperatures had
already dropped into the mid 30s in north central Kansas with
readings in the teens and 20s across much of Nebraska. This cold air
will overspread the forecast area today as the cold front tracks
southeast of the area by this afternoon. As a result, went with a
non-diurnal trend for temperatures today as most locations will see
temperatures steadily dropping through the day. High temperatures
will range from the lower 50s over east central Kansas down into the
middle 30s over north central Kansas. These plummeting temperatures
combined with scattered precipitation today through tonight will
result in a mixed bag of precipitation types. Over eastern Kansas,
temperatures should stay above freezing through the daytime hours
and keep precipitation in the form of light rain through this
afternoon and into early this evening. However, across north central
Kansas, temperatures are expected to drop into the middle 20s to
middle 30s through the day. Model soundings have consistently been
showing a prevailing warm nose of roughly +3C to +5C this afternoon
in that region, with saturation diminishing within the dendritic
growth zone. These features combined with dropping surface
temperatures will result in areas of light freezing rain, freezing
drizzle and/or sleet developing late this morning through this
afternoon across locations generally along and west of a line
stretching from Marysville to Manhattan and Council Grove. As
temperatures continue to plummet across eastern Kansas, expect to
see this mix of light freezing rain/drizzle and sleet shift into
northeast Kansas tonight. Locations generally southeast of I-35
likely won`t see this transition from rain to mixed wintry precip
until around midnight. Across north central Kansas, model soundings
show the warm nose diminishing this evening, so the loss of this
warmer air aloft combined with dropping surface temperatures will
result in the precipitation type transitioning over toward a mix of
sleet and snow before eventually becoming all snow by around 9pm
over far north central Kansas and closer to midnight over much of
northern and north central Kansas. Overnight low temperatures will
ultimately bottom out in the upper teens to upper 20s from northwest
to southeast over the CWA.
While several wintry precipitation types are expected with this
system, the one thing it lacks is abundant moisture. As a result,
much of the region will likely see a prolonged period of just light
precipitation. Snow accumulations over north central Kansas are
expected to be less than one inch and less than one-half inch over
east central Kansas. Ice accumulations are also expected to be light
at less than one-tenth inch. However, this light precipitation could
still be enough to cause slick road conditions across the region,
especially on bridges and overpasses. As a result, have extended the
Winter Weather Advisory to cover the entire outlook area by tonight.
One very noteworthy trend with the 00z model runs is the speed at
which the drier air moves into the area as surface high pressure
advances southward along the lee-side of the Rockies. The
GFS/ECMWF/GEM are all in agreement in having this precipitation
diminishing over north central Kansas after 06z with much of the
forecast area shown as being dry by around 12z Friday. However, both
the 00z and 06z runs of the NAM are much slower with the progression
of the dry air and keep precipitation across much of the CWA into
Friday morning. Considering the combination of these model trends
and current observations further north of the CWA, have trended more
with the progressive dry-air solutions of the GFS/ECMWF/GEM and thus
have trended downward with the PoPs after midnight, especially
across north central Kansas.
.LONG TERM...(Friday through Wednesday)
Issued at 517 AM CST THU NOV 21 2013
Southwest to zonal flow will be present across the Central Plains on
Friday. A northern Plains upper trough with energy extending south
into the Central Plains will move east into the Great Lakes and
Ontario Province by 00Z Saturday. The cold air depth increases
through the day on Friday. Drier air will move south into Kansas by
afternoon, effectively ending light snow in the northern counties.
Forecast soundings from models show a wintry mix as dry air aloft
will keep the dendritic snow growth portion of the sounding
unsaturated. So expect to see some periods of freezing drizzle,
freezing rain and sleet will all be possible at one time or another.
The GFS and ECMWF are much drier than the NAM with the moisture
profiles. Have gone with a compromise with them for this forecast.
With drier air advecting into northern Kansas in the afternoon
expect precipitation along the Nebraska border to come to an end
while light precipitation is expected to continue across east
central Kansas into the afternoon hours. Temperatures will be near
or below freezing through the day. Models show the the warm nose
around 850 MB to 800 MB going away by late afternoon in east central
Kansas and could see a brief period of light snow before sunset.
Cold arctic air will spread eastward across eastern Kansas with lows
dropping down into the teens to lower 20s.
For the weekend an upper level low in the southwest begins to move
out into the Southern Plains early next week. This may bring a
chance of the light snow or sleet into northeast and east central
Kansas Sunday night. The Upper low is forecast to move across Texas
then into the Gulf Coast States by mid week. With the low passing
well south it will keep any precipitation well to the south. Highs
int he 30s and 40s will be common with lows in the 20s Sunday
through Wednesday.
&&
.AVIATION...(For the 12Z TAFs through 12Z Friday Morning)
Issued at 545 AM CST THU NOV 21 2013
For the 12z TAFs, light rain showers will gradually spread northward
into the TAF sites this morning, with CIGS/VIS gradually diminishing
to MVFR conditions this morning and eventually to IFR conditions by
this afternoon. Breezy northerly winds behind the passage of the
cold front will be ushering much colder air into the region today
and tonight, resulting in these light rain showers transitioning
over to a wintry mix of freezing rain/drizzle, sleet, and eventually
light snow this afternoon through Friday morning. Late tonight into the
overnight hours, CIGS/VIS conditions may improve slightly to low-end
MVFR, but will need to continue to monitor the trends with this
precipitation.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 9 PM this evening to 9 AM CST
Friday FOR KSZ011-012-023-024-026.
WINTER WEATHER ADVISORY until 9 AM CST Friday FOR KSZ008>010-
020>022-034.
WINTER WEATHER ADVISORY from 9 PM this evening to 3 PM CST
Friday FOR KSZ037>040-054>056-058-059.
WINTER WEATHER ADVISORY until 3 PM CST Friday FOR KSZ035-036.
&&
$$
UPDATE...Wolters
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
712 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE SLOWLY SLIDES DOWN THE NORTHEAST ATLANTIC COAST
TODAY AND FRIDAY. A STRONG COLD FRONT CROSSES THE REGION ON
SATURDAY. CANADIAN HIGH PRESSURE BUILDS INTO THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK...USHERING IN THE COLDEST
TEMPERATURES OF THE FALL SEASON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRONG ~1040MB (+2 STD DEV MSLP) HIGH OVER THE ST LAWRENCE RIVER
VALLEY THIS MORNING CONTINUES TO RIDGE OVER THE LOCAL AREA.
ALOFT...RIDGE HAS LOCATED OVER THE ERN CONUS AS THIS WEEKENDS
STORM SYSTEM TAKES SHAPE OVER SRN CANADA. H85 HIGH HAS LOCATED
OVER ERN NC WITH FLOW AROUND THE WRN PERIPHERY BECOMING S-SW BELOW
A STRONG SUBSIDENCE INVERSION. RETURN FLOW WILL ADVECT MOISTURE
OVER THE CAROLINAS NWD THIS MORNING. ALREADY BEGINNING TO SEE BKN-
OVC MID DECK SPREAD OVER THE LOCAL AREA. SHOWERS HAVE DEVELOPED
OFF THE SE NC COAST ALONG A WEAK COASTAL BOUNDARY EARLY THIS
MORNING. LATEST RUC GUIDANCE SUGGESTS THAT THE BOUNDARY WILL
LINGER THRU THE MORNING BEFORE WEAKENING. MODEST UPPER LEVEL
SUPPORT AND MOISTURE OVERRUNNING THE BOUNDARY WILL RESULT IN
ISOLATED SPRINKLES OVER MAINLY NE NC THRU MID MORNING. NO
MEASURABLE RAINFALL IS ANTICIPATED.
WITH AFOREMENTIONED STRONG HIGH TO THE NORTH AND RIDGING OVER THE
LOCAL AREA (CAD SETUP)...EXPECT CLOUD COVER TO CONTINUE TO THICKEN
THRU THE MORNING INTO THE AFTERNOON. WAA WILL ALSO ENHANCE THE
CLOUD COVER. OTHERWISE...SFC HIGH WILL BEGIN TO BREAK DOWN
TODAY...DRIFTING SWD OFF THE NE COAST BUT REMAINING RIDGED OVER
THE LOCAL AREA. RIDGE AXIS WILL PUSH OFFSHORE LATE TODAY...BUT WLY
FLOW WILL CONTINUE ALOFT. THE RESULTANT WAA WILL BE ENOUGH TO WARM
TEMPS INTO THE LOW-MID 50S INLAND TO UPPER 50S ALONG THE COAST
(SLIGHTLY BELOW NORMAL)...REGARDLESS OF CLOUDY SKIES AND
PERSISTENT ONSHORE FLOW. MODELS REMAIN RATHER AGGRESSIVE WITH LIGHT
RAIN/DRIZZLE TODAY BUT DRY LOW LEVELS WILL PREVENT ANY CHANCE FOR
PRECIP TO MATERIALIZE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A STRONG COLD FRONT WILL CROSS THE LOCAL AREA LATE FRIDAY NIGHT
INTO EARLY SATURDAY MORNING...USHERING IN THE COLDEST AIR OF THE
FALL SEASON TO THE MID-ATLANTIC.
FRIDAY...
STRONG AMPLIFICATION OF NRN STREAM TROUGH ACROSS SRN CANADA AND
THE GREAT LAKES REGION WILL OCCUR FRIDAY. A LEAD SHORTWAVE WILL
PUSH AN ASSOCIATED COLD FRONT ACROSS THE OH VALLEY EARLY
FRI...REACHING THE CNTRL APPALACHIANS FRI AFTERNOON.
MEANWHILE...THE SFC HIGH WILL BREAK DOWN OVER THE REGION...WITH
SFC WINDS RETURNING TO THE SW. HOWEVER...WLY FLOW WILL CONTINUE
ALOFT...ADVECTING MOISTURE (+1 STD DEV PRECIP WATERS) FROM THE
KY/TN VALLEYS. INCREASING MOISTURE WILL REINFORCE THE CLOUD COVER
WITH MOSTLY CLOUDY-CLOUDY CONDITIONS EXPECTED AGAIN FRI.
INCREASING HEIGHTS/THICKNESSES AND H85 TEMPS +9C WILL TRANSLATE TO
TEMPS GENERALLY IN THE MID 60S...EVEN WITH CLOUD COVER. FRIDAY
WILL REMAIN DRY AS PRECIP WILL REMAIN ALONG THE FRONT OVER THE
CNTRL APPALACHIANS LATE FRIDAY.
FRIDAY NIGHT-SATURDAY...
LATEST MODEL GUIDANCE HAS BETTER RESOLVED THE DIFFERENCES WITH
THE LEADING SHORTWAVE FRIDAY...RESULTING IN BETTER AGREEMENT WITH
PUSHING THE FRONT OVER THE LOCAL AREA FRIDAY NIGHT. FORCING WILL
BE RATHER LIMITED AS THE TROUGH DYNAMICS WILL REMAIN WELL
NORTH...BUT SUFFICIENT MOISTURE ALONG THE FRONT WILL BE ENOUGH TO
PRODUCE SCATTERED LIGHT SHOWERS. BETTER MOISTURE AND OMEGA OVER
THE SE MAY LEAD TO BETTER DEVELOPMENT LATE FRI NIGHT...BUT WILL
ONLY LEAVE CHANCE POPS ATTM. QPF AMOUNTS WILL BE LIGHT WITH
AMOUNTS GENERALLY LESS THAN TWO TENTHS OF AN INCH. SEVERAL LOCALES
WILL ONLY RECEIVE A FEW HUNDREDTHS OF AN INCH. THE BIGGEST IMPACT
WILL NOT BE THE LIGHT PRECIP...BUT INSTEAD THE COLD AIR THAT WILL
ACCOMPANY THE FRONT. HIGHS WILL LIKELY BE REACHED SAT MORNING
(MID-UPPER 50S)...BEFORE TEMPS FALL DURING THE DAY SATURDAY. BY
6PM SAT...TEMPS ARE FORECAST TO BE IN THE LOW-MID 40S UNDER
RAPIDLY CLEARING SKIES. THE STRONGEST CAA WILL ARRIVE SAT NIGHT AS
NW WINDS INCREASE WITH GUSTS UP TO 25-30 MPH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CDFNT MOVES WELL OFF THE CST SAT NGT...AND ANY PCPN ASSOCIATED W/IT
XPCD TO END AFT MDNGT. DRY...MUCH COLDER AND WINDY WX XPCD SUN. SFC
HI PRES REACHES/BUILDS OVR THE RGN SUN NGT INTO MON. H85 TEMPS FCST
TO FALL TO OR BLO -10 DEGS C SUN NGT...THEN BE SLO TO RECOVER ON
MON. LO PRES TO SLO DEVELOP INVOF SRN PLAINS/WRN GULF STATES ERY
NEXT WEEK...THEN TRACK ENE TO THE MDATLC/SE STATES BY WED. WILL
BRING INCRSG CLDNS/POPS FM THE SW ON TUE. RIGHT NOW...HIGHEST PROB
FOR PCPN IS TUE NGT INTO WED AS SFC LO PRES TRACKS OFF THE CST OF
THE CAROLINAS.
LO TEMPS SAT NGT FM THE M20S W TO L30S AT THE CST. HI TEMPS SUN FM
THE M30S W AND N...TO ARND 40F SE (W/ WIND CHILLS IN THE 20S). LO
TEMPS SUN NGT FM ARND 20F INLAND TO U20S/ARND 30F AT THE CST. HI
TEMPS MON IN THE L/M40S. MODERATION CONTS MON NGT THROUGH TUE. LO
TEMPS MON NGT FM ARND 30F INLAND TO THE U30S NR THE CST...HI TEMPS
TUE FM THE M40S W TO L50S SE. HI TEMPS WED FM THE L40S WELL INLAND
TO L50S AT THE CST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
STRONG HIGH PRESSURE (NEARLY 1040MB) WILL BE SLOW TO RETREAT TODAY.
MEANWHILE...MOISTURE WILL INCREASE FROM THE S RESULTING IN
WIDESPREAD OVC CIGS. NAM/RUC HAVE BACKED-OFF FROM EARLIER
PESSIMISTIC FORECASTS WITH RESPECT TO CIGS. WILL CONTINUE WITH PREVAILING
CIGS FALLING TO 4K FT...WITH PERIODIC MVFR CIGS PRIMARILY AT
RIC/PHF. A LIGHT NE WIND SHOULD PREVAIL TODAY...BEFORE SHIFTING TO
SE TONIGHT.
HIGH PRESSURE SLOWLY SETTLES SSE THROUGH FRIDAY AS A STRONG COLD
FRONT APPROACHES FROM THE NW. A FEW -SHRA ARE POSSIBLE WITH THE
FRONTAL PASSAGE FRIDAY NIGHT/EARLY SATURDAY. A SECONDARY COLD FRONT
SWINGS THROUGH THE REGION SATURDAY NIGHT FOLLOWED BY A GUSTY NW WIND
SUNDAY. WIND SPEEDS ARE EXPECTED TO REACH 15-20KT...WITH GUSTS TO
25-30KT.
&&
.MARINE...
HIGH PRESSURE BUILDS ACROSS NEW ENGLAND THIS MORNING...BEFORE
SETTLING OFF OF CAPE COD AND GRADUALLY WEAKENING THIS AFTERNOON. THE
SURFACE PRESSURE GRADIENT SLACKENS ACROSS THE AREA ALLOWING THE
CURRENT E/NE WIND TO CONTINUE ITS DIMINISHING TREND. SCAS REMAIN IN
PLACE FOR WAVES/SEAS FOR THE MOUTH OF BAY THROUGH 12Z...OCEAN FROM
CAPE CHARLES TO VA/NC BORDER THROUGH 15Z...AND OCEAN OFF THE
CURRITUCK OUTER BANKS THROUGH 17Z. HIGH PRESSURE CONTINUES TO SINK S
AND WEAKEN OFF THE MID ATLANTIC AND SOUTHEAST COASTS TONIGHT THROUGH
FRIDAY. MEANWHILE...LOW PRESSURE TRACKS THROUGH THE SAINT LAWRENCE
VALLEY ALLOWING THE WIND TO SHIFT TO SW. THIS LOW PRESSURE SYSTEM
PULLS A COLD FRONT ACROSS THE MID ATLANTIC COAST FRIDAY
NIGHT...FOLLOWED BY A SHALLOW CAA SURGE. MINIMAL SCA CONDITIONS ARE
POSSIBLE FOR THE NON-OCEAN ZONES LATE FRIDAY NIGHT THROUGH SATURDAY
MORNING. A SECONDARY COLD FRONT ARRIVES SATURDAY EVENING...FOLLOWED
BY A 24-36HR STRONG CAA NW SURGE. THERE IS A HIGH LIKELIHOOD FOR
HIGH-END SCA CONDITIONS SATURDAY NIGHT THROUGH SUNDAY
EVENING...ALONG WITH THE POTENTIAL FOR GALE FORCE WIND (MAINLY IN
GUSTS). A GRADUAL IMPROVEMENT IS EXPECTED MONDAY INTO TUESDAY. THERE
IS A POTENTIAL FOR A MODERATE TO STRONG NNE WIND BY THE MIDDLE OF
NEXT WEEK AS LOW PRESSURE DEEPENS AND TRACKS OFF THE SOUTHEAST COAST.
&&
.EQUIPMENT...
THE KAKQ RADAR WILL BE DOWN THROUGH AT LEAST TUESDAY, NOVEMBER 26TH
FOR RADOME REPAIRS. SEE THE PUBLIC INFORMATION STATEMENT (PNSAKQ)
FOR ADDITIONAL DETAILS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ656-
658.
&&
$$
SYNOPSIS...BMD/SAM
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...ALB
AVIATION...AJZ
MARINE...AJZ
EQUIPMENT...AKQ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
443 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE SLOWLY SLIDES DOWN THE NORTHEAST ATLANTIC COAST
TODAY AND FRIDAY. A STRONG COLD FRONT CROSSES THE REGION ON
SATURDAY. CANADIAN HIGH PRESSURE BUILDS INTO THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK...USHERING IN THE COLDEST
TEMPERATURES OF THE FALL SEASON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRONG ~1040MB (+2 STD DEV MSLP) HIGH OVER THE ST LAWRENCE RIVER
VALLEY THIS MORNING CONTINUES TO RIDGE OVER THE LOCAL AREA.
ALOFT...RIDGE HAS LOCATED OVER THE ERN CONUS AS THIS WEEKENDS
STORM SYSTEM TAKES SHAPE OVER SRN CANADA. H85 HIGH HAS LOCATED
OVER ERN NC WITH FLOW AROUND THE WRN PERIPHERY BECOMING S-SW BELOW
A STRONG SUBSIDENCE INVERSION. RETURN FLOW WILL ADVECT MOISTURE
OVER THE CAROLINAS NWD THIS MORNING. ALREADY BEGINNING TO SEE BKN-
OVC MID DECK SPREAD OVER THE LOCAL AREA. SHOWERS HAVE DEVELOPED
OFF THE SE NC COAST ALONG A WEAK COASTAL BOUNDARY EARLY THIS
MORNING. LATEST RUC GUIDANCE SUGGESTS THAT THE BOUNDARY WILL
LINGER THRU THE MORNING BEFORE WEAKENING. MODEST UPPER LEVEL
SUPPORT AND MOISTURE OVERRUNNING THE BOUNDARY WILL RESULT IN
ISOLATED SPRINKLES OVER MAINLY NE NC THRU MID MORNING. NO
MEASURABLE RAINFALL IS ANTICIPATED.
WITH AFOREMENTIONED STRONG HIGH TO THE NORTH AND RIDGING OVER THE
LOCAL AREA (CAD SETUP)...EXPECT CLOUD COVER TO CONTINUE TO THICKEN
THRU THE MORNING INTO THE AFTERNOON. WAA WILL ALSO ENHANCE THE
CLOUD COVER. OTHERWISE...SFC HIGH WILL BEGIN TO BREAK DOWN
TODAY...DRIFTING SWD OFF THE NE COAST BUT REMAINING RIDGED OVER
THE LOCAL AREA. RIDGE AXIS WILL PUSH OFFSHORE LATE TODAY...BUT WLY
FLOW WILL CONTINUE ALOFT. THE RESULTANT WAA WILL BE ENOUGH TO WARM
TEMPS INTO THE LOW-MID 50S INLAND TO UPPER 50S ALONG THE COAST
(SLIGHTLY BELOW NORMAL)...REGARDLESS OF CLOUDY SKIES AND
PERSISTENT ONSHORE FLOW. MODELS REMAIN RATHER AGGRESSIVE WITH LIGHT
RAIN/DRIZZLE TODAY BUT DRY LOW LEVELS WILL PREVENT ANY CHANCE FOR
PRECIP TO MATERIALIZE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A STRONG COLD FRONT WILL CROSS THE LOCAL AREA LATE FRIDAY NIGHT
INTO EARLY SATURDAY MORNING...USHERING IN THE COLDEST AIR OF THE
FALL SEASON TO THE MID-ATLANTIC.
FRIDAY...
STRONG AMPLIFICATION OF NRN STREAM TROUGH ACROSS SRN CANADA AND
THE GREAT LAKES REGION WILL OCCUR FRIDAY. A LEAD SHORTWAVE WILL
PUSH AN ASSOCIATED COLD FRONT ACROSS THE OH VALLEY EARLY
FRI...REACHING THE CNTRL APPALACHIANS FRI AFTERNOON.
MEANWHILE...THE SFC HIGH WILL BREAK DOWN OVER THE REGION...WITH
SFC WINDS RETURNING TO THE SW. HOWEVER...WLY FLOW WILL CONTINUE
ALOFT...ADVECTING MOISTURE (+1 STD DEV PRECIP WATERS) FROM THE
KY/TN VALLEYS. INCREASING MOISTURE WILL REINFORCE THE CLOUD COVER
WITH MOSTLY CLOUDY-CLOUDY CONDITIONS EXPECTED AGAIN FRI.
INCREASING HEIGHTS/THICKNESSES AND H85 TEMPS +9C WILL TRANSLATE TO
TEMPS GENERALLY IN THE MID 60S...EVEN WITH CLOUD COVER. FRIDAY
WILL REMAIN DRY AS PRECIP WILL REMAIN ALONG THE FRONT OVER THE
CNTRL APPALACHIANS LATE FRIDAY.
FRIDAY NIGHT-SATURDAY...
LATEST MODEL GUIDANCE HAS BETTER RESOLVED THE DIFFERENCES WITH
THE LEADING SHORTWAVE FRIDAY...RESULTING IN BETTER AGREEMENT WITH
PUSHING THE FRONT OVER THE LOCAL AREA FRIDAY NIGHT. FORCING WILL
BE RATHER LIMITED AS THE TROUGH DYNAMICS WILL REMAIN WELL
NORTH...BUT SUFFICIENT MOISTURE ALONG THE FRONT WILL BE ENOUGH TO
PRODUCE SCATTERED LIGHT SHOWERS. BETTER MOISTURE AND OMEGA OVER
THE SE MAY LEAD TO BETTER DEVELOPMENT LATE FRI NIGHT...BUT WILL
ONLY LEAVE CHANCE POPS ATTM. QPF AMOUNTS WILL BE LIGHT WITH
AMOUNTS GENERALLY LESS THAN TWO TENTHS OF AN INCH. SEVERAL LOCALES
WILL ONLY RECEIVE A FEW HUNDREDTHS OF AN INCH. THE BIGGEST IMPACT
WILL NOT BE THE LIGHT PRECIP...BUT INSTEAD THE COLD AIR THAT WILL
ACCOMPANY THE FRONT. HIGHS WILL LIKELY BE REACHED SAT MORNING
(MID-UPPER 50S)...BEFORE TEMPS FALL DURING THE DAY SATURDAY. BY
6PM SAT...TEMPS ARE FORECAST TO BE IN THE LOW-MID 40S UNDER
RAPIDLY CLEARING SKIES. THE STRONGEST CAA WILL ARRIVE SAT NIGHT AS
NW WINDS INCREASE WITH GUSTS UP TO 25-30 MPH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CDFNT MOVES WELL OFF THE CST SAT NGT...AND ANY PCPN ASSOCIATED W/IT
XPCD TO END AFT MDNGT. DRY...MUCH COLDER AND WINDY WX XPCD SUN. SFC
HI PRES REACHES/BUILDS OVR THE RGN SUN NGT INTO MON. H85 TEMPS FCST
TO FALL TO OR BLO -10 DEGS C SUN NGT...THEN BE SLO TO RECOVER ON
MON. LO PRES TO SLO DEVELOP INVOF SRN PLAINS/WRN GULF STATES ERY
NEXT WEEK...THEN TRACK ENE TO THE MDATLC/SE STATES BY WED. WILL
BRING INCRSG CLDNS/POPS FM THE SW ON TUE. RIGHT NOW...HIGHEST PROB
FOR PCPN IS TUE NGT INTO WED AS SFC LO PRES TRACKS OFF THE CST OF
THE CAROLINAS.
LO TEMPS SAT NGT FM THE M20S W TO L30S AT THE CST. HI TEMPS SUN FM
THE M30S W AND N...TO ARND 40F SE (W/ WIND CHILLS IN THE 20S). LO
TEMPS SUN NGT FM ARND 20F INLAND TO U20S/ARND 30F AT THE CST. HI
TEMPS MON IN THE L/M40S. MODERATION CONTS MON NGT THROUGH TUE. LO
TEMPS MON NGT FM ARND 30F INLAND TO THE U30S NR THE CST...HI TEMPS
TUE FM THE M40S W TO L50S SE. HI TEMPS WED FM THE L40S WELL INLAND
TO L50S AT THE CST.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
STRONG HIGH PRESSURE (NEARLY 1040MB) WILL BE SLOW TO RETREAT TODAY.
MEANWHILE...MOISTURE WILL INCREASE FROM THE S RESULTING IN
WIDESPREAD OVC CIGS. NOT CURRENTLY GOING AS PESSIMISTIC AS THE
NAM/RUC...WHICH SUGGEST THE POTENTIAL FOR IFR/LOW MVFR CIGS LATER
TODAY ALONG WITH -RA/DZ...AS SREF PROBS INDICATE THE HIGHEST
LIKELIHOOD OF IFR OVER THE MOUNTAINS. THE 06Z FORECAST WILL HAVE
PREVAILING CIGS FALLING TO 4K FT AT MOST SITES WITH 2K FT AT
RIC/PHF. A LIGHT NE WIND SHOULD PREVAIL TODAY...BEFORE SHIFTING TO
SE TONIGHT.
HIGH PRESSURE SLOWLY SETTLES SSE THROUGH FRIDAY AS A STRONG COLD
FRONT APPROACHES FROM THE NW. A FEW -SHRA ARE POSSIBLE WITH THE
FRONTAL PASSAGE FRIDAY NIGHT/EARLY SATURDAY. A SECONDARY COLD FRONT
SWINGS THROUGH THE REGION SATURDAY NIGHT FOLLOWED BY A GUSTY NW WIND
SUNDAY. WIND SPEEDS ARE EXPECTED TO REACH 15-20KT...WITH GUSTS TO
25-30KT.
&&
.MARINE...
HIGH PRESSURE BUILDS ACROSS NEW ENGLAND THIS MORNING...BEFORE
SETTLING OFF OF CAPE COD AND GRADUALLY WEAKENING THIS AFTERNOON. THE
SURFACE PRESSURE GRADIENT SLACKENS ACROSS THE AREA ALLOWING THE
CURRENT E/NE WIND TO CONTINUE ITS DIMINISHING TREND. SCAS REMAIN IN
PLACE FOR WAVES/SEAS FOR THE MOUTH OF BAY THROUGH 12Z...OCEAN FROM
CAPE CHARLES TO VA/NC BORDER THROUGH 15Z...AND OCEAN OFF THE
CURRITUCK OUTER BANKS THROUGH 17Z. HIGH PRESSURE CONTINUES TO SINK S
AND WEAKEN OFF THE MID ATLANTIC AND SOUTHEAST COASTS TONIGHT THROUGH
FRIDAY. MEANWHILE...LOW PRESSURE TRACKS THROUGH THE SAINT LAWRENCE
VALLEY ALLOWING THE WIND TO SHIFT TO SW. THIS LOW PRESSURE SYSTEM
PULLS A COLD FRONT ACROSS THE MID ATLANTIC COAST FRIDAY
NIGHT...FOLLOWED BY A SHALLOW CAA SURGE. MINIMAL SCA CONDITIONS ARE
POSSIBLE FOR THE NON-OCEAN ZONES LATE FRIDAY NIGHT THROUGH SATURDAY
MORNING. A SECONDARY COLD FRONT ARRIVES SATURDAY EVENING...FOLLOWED
BY A 24-36HR STRONG CAA NW SURGE. THERE IS A HIGH LIKELIHOOD FOR
HIGH-END SCA CONDITIONS SATURDAY NIGHT THROUGH SUNDAY
EVENING...ALONG WITH THE POTENTIAL FOR GALE FORCE WIND (MAINLY IN
GUSTS). A GRADUAL IMPROVEMENT IS EXPECTED MONDAY INTO TUESDAY. THERE
IS A POTENTIAL FOR A MODERATE TO STRONG NNE WIND BY THE MIDDLE OF
NEXT WEEK AS LOW PRESSURE DEEPENS AND TRACKS OFF THE SOUTHEAST COAST.
&&
.EQUIPMENT...
THE KAKQ RADAR WILL BE DOWN THROUGH AT LEAST TUESDAY, NOVEMBER 26TH
FOR RADOME REPAIRS. SEE THE PUBLIC INFORMATION STATEMENT (PNSAKQ)
FOR ADDITIONAL DETAILS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ658.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ656.
&&
$$
SYNOPSIS...BMD/SAM
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...ALB
AVIATION...AJZ
MARINE...AJZ
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
405 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE SLOWLY SLIDES DOWN THE NORTHEAST ATLANTIC COAST
TODAY AND FRIDAY. A STRONG COLD FRONT CROSSES THE REGION ON SATURDAY.
ANOTHER CANADIAN HIGH PRESSURE SYSTEM BUILDS INTO THE AREA EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRONG ~1040MB (+2 STD DEV MSLP) HIGH OVER THE ST LAWRENCE RIVER
VALLEY THIS MORNING CONTINUES TO RIDGE OVER THE LOCAL AREA.
ALOFT...RIDGE HAS LOCATED OVER THE ERN CONUS AS THIS WEEKENDS
STORM SYSTEM TAKES SHAPE OVER SRN CANADA. H85 HIGH HAS LOCATED
OVER ERN NC WITH FLOW AROUND THE WRN PERIPHERY BECOMING S-SW BELOW
A STRONG SUBSIDENCE INVERSION. RETURN FLOW WILL ADVECT MOISTURE
OVER THE CAROLINAS NWD THIS MORNING. ALREADY BEGINNING TO SEE BKN-
OVC MID DECK SPREAD OVER THE LOCAL AREA. SHOWERS HAVE DEVELOPED
OFF THE SE NC COAST ALONG A WEAK COASTAL BOUNDARY EARLY THIS
MORNING. LATEST RUC GUIDANCE SUGGESTS THAT THE BOUNDARY WILL
LINGER THRU THE MORNING BEFORE WEAKENING. MODEST UPPER LEVEL
SUPPORT AND MOISTURE OVERRUNNING THE BOUNDARY WILL RESULT IN
ISOLATED SPRINKLES OVER MAINLY NE NC THRU MID MORNING. NO
MEASURABLE RAINFALL IS ANTICIPATED.
WITH AFOREMENTIONED STRONG HIGH TO THE NORTH AND RIDGING OVER THE
LOCAL AREA (CAD SETUP)...EXPECT CLOUD COVER TO CONTINUE TO THICKEN
THRU THE MORNING INTO THE AFTERNOON. WAA WILL ALSO ENHANCE THE
CLOUD COVER. OTHERWISE...SFC HIGH WILL BEGIN TO BREAK DOWN
TODAY...DRIFTING SWD OFF THE NE COAST BUT REMAINING RIDGED OVER
THE LOCAL AREA. RIDGE AXIS WILL PUSH OFFSHORE LATE TODAY...BUT WLY
FLOW WILL CONTINUE ALOFT. THE RESULTANT WAA WILL BE ENOUGH TO WARM
TEMPS INTO THE LOW-MID 50S INLAND TO UPPER 50S ALONG THE COAST
(SLIGHTLY BELOW NORMAL)...REGARDLESS OF CLOUDY SKIES AND
PERSISTENT ONSHORE FLOW. MODELS REMAIN RATHER AGGRESSIVE WITH LIGHT
RAIN/DRIZZLE TODAY BUT DRY LOW LEVELS WILL PREVENT ANY CHANCE FOR
PRECIP TO MATERIALIZE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE WX PATTERN CHANGES ON FRIDAY AS SFC HIGH PRESSURE BREAKS DOWN
AND A STRONG COLD FRONT CROSSES THE OH VALLEY AND HEADS FOR THE
MID ATLANTIC REGION. WARM AIR ADVECTION FROM THE SW WILL CONTINUE
INCREASING TRENDS IN TEMP/DEWPOINT FIELDS DESPITE MOSTLY CLOUDY TO
CLOUDY SKIES. EXPECT HIGHS IN THE LOWER TO MID 60S AREAWIDE (UPPER
60S POSSIBLE COASTAL SE VA/NE NC). A LEE TROUGH DEVELOPS BY FRI
AFTN AND THE PERSISTENT ONSHORE WINDS FROM THE PAST SEVERAL DAY
WILL FINALLY TURN TO THE S-SW THROUGH THE DAY. THE MORE ROBUST
CONVECTIVE-BASED MODELS ARE GENERATING PRECIPITATION DURING THE
AFTN. CURRENT THINKING IS THAT THESE PARTICULAR MODELS ARE
OVERDONE. WEST WINDS ALOFT AND DEVELOPING SW SFC WINDS WILL ACT TO
DOWNSLOPE THE AREA AND KEEP CONDITIONS DRY...WHICH IS MORE IN LINE
WITH THE MORE BROAD-BRUSHED MODEL SOLUTIONS THAT TEND TO BE CLOSER
TO REALITY WHEN IT COMES TO THE DAY 3 FORECAST. WILL NEED TO SEE
HOW 12Z MODELS TREND TOMORROW REGARDING POTENTIAL PRECIP FRI AFTN.
A STRONG COLD FRONT WILL PUSH ACROSS THE MID ATLANTIC REGION LATE
FRI NIGHT INTO SATURDAY MORNING...WHICH WILL PROVIDE THE BEST SHOT
FOR PRECIPITATION WITHIN THE SHORT TERM FORECAST. OVERALL QPF
AMOUNTS ARE LESS THAN 0.25 INCHES AND WILL FALL AS ALL RAIN. THE
COLDER AIR MOVING IN BEHIND THE FRONT WILL NOT ARRIVE UNTIL AFTER
THE PRECIP HAS MOVED OFFSHORE. WILL NEED TO MONITOR ANY CHANGES
CLOSELY SINCE TIMING DIFFERENCES COULD INFLUENCE P-TYPE (MAINLY IF
THE FRONT IS SLOWER TO PUSH THROUGH THE AREA). THIS SYSTEM WILL
PRODUCE A TIGHT SFC PRESSURE GRADIENT AND A TIGHT TEMPERATURE
GRADIENT AS ANOTHER COLD ARCTIC AIRMASS MOVES IN BEHIND THE
DEPARTING FRONT. SW WINDS WILL SHIFT TO THE W JUST AHEAD OF THE
FRONTAL PASSAGE AND TEMPS WILL STAY ELEVATED OVERNIGHT...WITH LOWS
IN THE UPPER 40S NW TO LOWER 50S SE. HIGH TEMPS ON SAT SHOULD PEAK
IN THE MID 50S TO LOWER 60S SE BY LATE MORNING...THEN FALL THROUGH
THE DAY AS BREEZY WINDS TURN TO THE NW AND THE ARCTIC AIRMASS
BEGINS TO INFILTRATE THE REGION FROM THE NW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CDFNT MOVES WELL OFF THE CST SAT NGT...AND ANY PCPN ASSOCIATED W/IT
XPCD TO END AFT MDNGT. DRY...MUCH COLDER AND WINDY WX XPCD SUN. SFC
HI PRES REACHES/BUILDS OVR THE RGN SUN NGT INTO MON. H85 TEMPS FCST
TO FALL TO OR BLO -10 DEGS C SUN NGT...THEN BE SLO TO RECOVER ON
MON. LO PRES TO SLO DEVELOP INVOF SRN PLAINS/WRN GULF STATES ERY
NEXT WEEK...THEN TRACK ENE TO THE MDATLC/SE STATES BY WED. WILL
BRING INCRSG CLDNS/POPS FM THE SW ON TUE. RIGHT NOW...HIGHEST PROB
FOR PCPN IS TUE NGT INTO WED AS SFC LO PRES TRACKS OFF THE CST OF
THE CAROLINAS.
LO TEMPS SAT NGT FM THE M20S W TO L30S AT THE CST. HI TEMPS SUN FM
THE M30S W AND N...TO ARND 40F SE (W/ WIND CHILLS IN THE 20S). LO
TEMPS SUN NGT FM ARND 20F INLAND TO U20S/ARND 30F AT THE CST. HI
TEMPS MON IN THE L/M40S. MODERATION CONTS MON NGT THROUGH TUE. LO
TEMPS MON NGT FM ARND 30F INLAND TO THE U30S NR THE CST...HI TEMPS
TUE FM THE M40S W TO L50S SE. HI TEMPS WED FM THE L40S WELL INLAND
TO L50S AT THE CST.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
STRONG HIGH PRESSURE (NEARLY 1040MB) WILL BE SLOW TO RETREAT TODAY.
MEANWHILE...MOISTURE WILL INCREASE FROM THE S RESULTING IN
WIDESPREAD OVC CIGS. NOT CURRENTLY GOING AS PESSIMISTIC AS THE
NAM/RUC...WHICH SUGGEST THE POTENTIAL FOR IFR/LOW MVFR CIGS LATER
TODAY ALONG WITH -RA/DZ...AS SREF PROBS INDICATE THE HIGHEST
LIKELIHOOD OF IFR OVER THE MOUNTAINS. THE 06Z FORECAST WILL HAVE
PREVAILING CIGS FALLING TO 4K FT AT MOST SITES WITH 2K FT AT
RIC/PHF. A LIGHT NE WIND SHOULD PREVAIL TODAY...BEFORE SHIFTING TO
SE TONIGHT.
HIGH PRESSURE SLOWLY SETTLES SSE THROUGH FRIDAY AS A STRONG COLD
FRONT APPROACHES FROM THE NW. A FEW -SHRA ARE POSSIBLE WITH THE
FRONTAL PASSAGE FRIDAY NIGHT/EARLY SATURDAY. A SECONDARY COLD FRONT
SWINGS THROUGH THE REGION SATURDAY NIGHT FOLLOWED BY A GUSTY NW WIND
SUNDAY. WIND SPEEDS ARE EXPECTED TO REACH 15-20KT...WITH GUSTS TO
25-30KT.
&&
.MARINE...
HIGH PRESSURE BUILDS ACROSS NEW ENGLAND THIS MORNING...BEFORE
SETTLING OFF OF CAPE COD AND GRADUALLY WEAKENING THIS AFTERNOON. THE
SURFACE PRESSURE GRADIENT SLACKENS ACROSS THE AREA ALLOWING THE
CURRENT E/NE WIND TO CONTINUE ITS DIMINISHING TREND. SCAS REMAIN IN
PLACE FOR WAVES/SEAS FOR THE MOUTH OF BAY THROUGH 12Z...OCEAN FROM
CAPE CHARLES TO VA/NC BORDER THROUGH 15Z...AND OCEAN OFF THE
CURRITUCK OUTER BANKS THROUGH 17Z. HIGH PRESSURE CONTINUES TO SINK S
AND WEAKEN OFF THE MID ATLANTIC AND SOUTHEAST COASTS TONIGHT THROUGH
FRIDAY. MEANWHILE...LOW PRESSURE TRACKS THROUGH THE SAINT LAWRENCE
VALLEY ALLOWING THE WIND TO SHIFT TO SW. THIS LOW PRESSURE SYSTEM
PULLS A COLD FRONT ACROSS THE MID ATLANTIC COAST FRIDAY
NIGHT...FOLLOWED BY A SHALLOW CAA SURGE. MINIMAL SCA CONDITIONS ARE
POSSIBLE FOR THE NON-OCEAN ZONES LATE FRIDAY NIGHT THROUGH SATURDAY
MORNING. A SECONDARY COLD FRONT ARRIVES SATURDAY EVENING...FOLLOWED
BY A 24-36HR STRONG CAA NW SURGE. THERE IS A HIGH LIKELIHOOD FOR
HIGH-END SCA CONDITIONS SATURDAY NIGHT THROUGH SUNDAY
EVENING...ALONG WITH THE POTENTIAL FOR GALE FORCE WIND (MAINLY IN
GUSTS). A GRADUAL IMPROVEMENT IS EXPECTED MONDAY INTO TUESDAY. THERE
IS A POTENTIAL FOR A MODERATE TO STRONG NNE WIND BY THE MIDDLE OF
NEXT WEEK AS LOW PRESSURE DEEPENS AND TRACKS OFF THE SOUTHEAST COAST.
&&
.EQUIPMENT...
THE KAKQ RADAR WILL BE DOWN THROUGH AT LEAST TUESDAY, NOVEMBER 26TH
FOR RADOME REPAIRS. SEE THE PUBLIC INFORMATION STATEMENT (PNSAKQ)
FOR ADDITIONAL DETAILS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ658.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ656.
&&
$$
SYNOPSIS...BMD
NEAR TERM...SAM
SHORT TERM...BMD
LONG TERM...ALB
AVIATION...AJZ
MARINE...AJZ
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
623 PM EST FRI NOV 22 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 341 PM EST FRI NOV 22 2013
COLD AIR WILL MOVE IN AND BRING LAKE EFFECT SNOW SHOWERS OVER THE
WEEKEND. FROM 2 TO 4 INCHES OF SNOW AN BE EXPECTED ALONG THE LAKE
MICHIGAN COASTAL COUNTIES WITH AN INCH OR LESS INLAND. A CLIPPER
WILL BRING SOME LIGHT SNOW ON MONDAY AND MORE COLD AIR WILL ARRIVE
LATER IN THE WEEK. AT THIS POINT...IT LOOKS LIKE THERE WILL BE NO
BIG STORMS FOR THANKSGIVING TRAVELERS IN MICHIGAN.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 341 PM EST FRI NOV 22 2013
FORECAST IMPACTS ARE FOR LAKE EFFECT SNOW SHOWERS BEGINNING LATE
TONIGHT AND LASTING INTO SUNDAY. THE HEAVIEST SNOW SHOULD FALL
SATURDAY NIGHT AND ACCUMS OF 2 TO 4 INCHES ARE POSSIBLE BY THE
TIME THE EVENT WINDS DOWN. TRAVEL IMPACTS ARE MITIGATED BY THIS
OCCURRING ON A WEEKEND NIGHT...SO NO ADVISORY SHOULD BE NEEDED.
FLOW LOOKS TO BE NW DURING MOST OF THE EVENT BUT THEN GOES WEST
LATE SUNDAY. BY THAT TIME...INVERSION HEIGHTS ARE LOWERING AND
WARM AIR ADVECTION IS BEGINNING SO THE SNOW SHOWERS THAT MOVE
INLAND ON WEST FLOW SHOULD BE LIGHT.
WE TRANSITION TO A WARM ADVECTION SNOW EVENT LATE SUNDAY NIGHT AS
A CLIPPER IS COMING DOWN FROM CENTRAL CANADA...BUT THE BULK OF
THAT SHOULD ARRIVE AFTER SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 341 PM EST FRI NOV 22 2013
NEXT WEEK WILL BE FAIRLY CHILLY WITH HIGHS IN THE 30S. A COLD FRONT
WILL CROSS LOWER MICHIGAN TUESDAY AND PROVIDE AN OPPORTUNITY FOR
LIGHT SNOW SHOWERS. INVERSION HEIGHTS BRIEFLY CLIMB TO AROUND 6K FT
LATE TUESDAY AND THAT LOOKS TO BE THE BEST OPPORTUNITY FOR SHSN.
HOWEVER...BOUNDARY LAYER WINDS QUICKLY BECOME NORTHERLY AS THE CORE
OF THE COLD AIR MOVES EAST AND WILL LIMIT THE SNOW POTENTIAL EXCEPT
ADJACENT TO THE LAKE SHORE. THANKSGIVING AND FRIDAY LOOK MAINLY DRY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 622 PM EST FRI NOV 22 2013
EXPECT A BAND OF SNOW SHOWERS AROUND SUNRISE SATURDAY TO BRING A
BRIEF PERIOD OF IFR CONDITIONS WITH SOME BLOWING SNOW TO THE THE
TAF SITES OUTSIDE OF THE I-69 CORRIDOR.
OTHERWISE THE CLEARING THAT IS ALREADY UNDERWAY... AS I WRITE THIS
AT 2315Z... WILL CONTINUE TO PROGRESS TO ALL OF OUR TAF SITES
THIS EVENING. BY 01Z- 02Z IT SEEM TO ME ALL TAF SITES SHOULD HAVE
EITHER CLEAR SKIES OR JUST CIRRUS CLOUDS. THIS IS THANKS TO A HIGH
PRESSURE RIDGE MOVING THROUGH THE AREA BEHIND THE FIRST COLD
FRONT.
THERE IS HOWEVER AN ARCTIC COLD FRONT OVER WESTERN LAKE SUPERIOR
AT 23Z. THAT FRONT WILL DROP SOUTH THROUGH THE NIGHT REACHING THE
GRR CWA TAF SITES IN THE 10Z-14Z TIME FRAME. GIVEN THE STRONG
CONVERGENCE ON THE FRONT AND DECENT DYNAMICS...PLUS SIGNIFICANT
LIFT IN THE DGZ ALONG THE FRONT... I EXPECT A NARROW BAND OF
MODERATE TO HEAVY SNOW SHOWERS TO DROP SOUTH THROUGH ALL BUT THE
JXN TAF SITES WITH THE FRONT. THIS BAND OF SNOW SHOWERS IS SHOWN
BY THE NAM...NAMDNG5...RAP AND HRRR MODELS. ONCE THROUGH THERE
WILL ONCE AGAIN BE A BRIEF CLEARING. HOWEVER BY MID TO LATE
AFTERNOON LAKE EFFECT SHOULD KICK IN NEAR AND WEST OF US-131 SO
THOSE SITES SHOULD SEE SOME SNOW SHOWERS DURING THE AFTERNOON AND
EVENING. MKG AND AZO SHOULD SEE THE MOST DETERIORATED CONDITIONS
DUE TO THE LAKE EFFECT SNOW SHOWERS SATURDAY AFTERNOON.
&&
.MARINE...
ISSUED AT 354 PM EST FRI NOV 22 2013
GALE WATCH IS UPGRADED TO A WARNING BEGINNING 9 AM SATURDAY.
NORTHWEST GALES TO 35 KNOTS SATURDAY COMBINE WITH FREQUENT SNOW
SQUALLS TO MAKE LAKE MICHIGAN HAZARDOUS TO MARINERS. KEPT THE GALE
WARNING GOING INTO SUNDAY AFTERNOON ALTHOUGH THIS MAY BE ABLE TO
BE DOWNGRADED TO SMALL CRAFT ADVISORY AS WINDS MAY SLACKEN A BIT
LATE SATURDAY NIGHT INTO SUNDAY MORNING AS HIGH PRESSURE BEGINS TO
TEMPORARILY BUILD IN.
&&
.HYDROLOGY...
ISSUED AT 341 PM EST FRI NOV 22 2013
NO HYDRO ISSUES THIS WEEK WITH COLD AIR AND FROZEN PRECIP.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 9 AM EST SATURDAY FOR LMZ844>849.
GALE WARNING FROM 9 AM SATURDAY TO 4 PM EST SUNDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...93
AVIATION...WDM
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1155 PM EST WED NOV 20 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 416 PM EST WED NOV 20 2013
THE OVERALL WEATHER PATTERN WILL REMAIN QUITE MESSY...MAKING THE
OVERALL FORECAST TRICKY OVER THE NEXT DAY. A LIGHT WET SNOW IS
EXPECTED ACROSS THE INTERIOR WEST THIS EVENING BEFORE A COLD FRONT
PUSHES INTO THE WESTERN CWA THURSDAY AFTERNOON.
LATE THIS AFTERNOON AND TONIGHT...MID-LEVEL SW FLOW AHEAD OF DEEP
TROUGHING DEVELOPING ACROSS CENTRAL CANADA WILL CONTINUE THROUGH
THURSDAY. AN ASSOCIATED SFC TROUGH ORIENTED ACROSS THE UPPER MS
VALLEY BETWEEN LOW PRESSURE OVER HUDSON BAY AND DEVELOPING LOW
PRESSURE ACROSS THE SOUTHERN HIGH PLAINS WILL SLOWLY PUSH EAST. A
WELL-DEFINED MID-LEVEL SHORTWAVE TROUGH CURRENTLY CENTERED NEAR
SIOUX FALLS WILL CONTINUE ITS NORTHEASTWARD PROGRESSION THIS EVENING
AND BE THE MAIN PLAYER IN PRECIPITATION.
MANY CONVOLUTED FORCING MECHANISMS WILL BE AT WORK THIS EVENING. A
COMPLICATED LOW-LEVEL FGEN PATTERN SLOPING TO THE SE WITH HEIGHT AND
A WEAK UPPER-LEVEL JET STREAK MERGING WITH THE POLAR JET WILL IMPOSE
CONFLICTING OMEGA FIELDS ON EACH OTHER. THIS WEAK UPPER JET STREAK
APPEARS TO BE SOME CONVECTIVE FEEDBACK TIED TO A CLUSTER OF
PERSISTENT STORMS OVER IA AND MO. MEANWHILE...WEAK ISENTROPIC ASCENT
ON THE 290-295K SFCS WILL ASSIST SOME MID-LEVEL PRECIP DEVELOPMENT
THIS EVENING. OVERALL...PRECIP LOOKS TO BE CONTROLLED BY THE
ISENTROPIC ASCENT AND Q-VECTOR CONV WITH THE MID-LEVEL WAVE.
A BROKEN SHIELD OF RAIN AND SNOW SHOWERS HAS DEVELOPED ACROSS
WESTERN WI OVER THE PAST SEVERAL HOURS. THIS HAS EASED SOME CONCERNS
THAT THE MIXED OMEGA FIELD WOULD SUPPRESS PRECIP. THE RAP HAS
MAINTAINED A DECENT HANDLE ON THE PRECIP EVOLUTION...SO HAVE
FOLLOWED IT FOR THE OVERALL PRECIP PATTERN WHILE EMPLOYING THE NAM
FOR THE SYNOPTIC EVOLUTION. PRECIP HAS JUST STARTED TO SPREAD INTO
THE INTERIOR WEST NEAR WI AND WILL CONTINUE NORTHWARD INTO THE
EVENING. THERE IS GOOD AGREEMENT THAT THE GREATEST COVERAGE WILL BE
MID TO LATE EVENING ACROSS MUCH OF THE WEST HALF OF THE CWA BEFORE
PRECIP SPREADS EASTWARD OVERNIGHT WITH THE WAVE.
PTYPE LOOKS TO BE MOSTLY WET SNOW FOR ALL BUT THE NEAR LAKE SUPERIOR
SHORELINE AS WETBULB ZERO LEVELS WILL BE WELL BELOW 1KFT. A SUB
700MB DRY LAYER MAY INHIBIT PRECIP INITIALLY...BUT GIVEN CURRENT
RADAR RETURNS IN WI...PRECIP RATES SHOULD BE HIGH ENOUGH TO OVERCOME
THE DRY AIR IN A HOUR OR SO. SNOW RATIOS SHOULD BE QUITE
LOW...GENERALLY 8-10:1 AS MOST LIFT WILL BE W/IN TEMPS HIGHER THAN
THE DGZ. SOME AGGREGATION COULD BE POSSIBLE THROUGH A DEEP
ISOTHERMAL LAYER BETWEEN -3 AND -5C...SO LARGER WET FLAKES ARE
POSSIBLE. TOTAL SNOWFALL THROUGH TONIGHT IS FORECAST TO BE 0.5-1.5
INCHES FOR THE INTERIOR WEST HALF...HIGHEST FROM IRON RIVER TO
CHAMPION. WOULD NOT BE SURPRISED IF SOME LOCATIONS TOP 2 INCHES
GIVEN THE HEAVIER SHOWER ACTIVITY EXPECTED. SHORELINE LOCATIONS WILL
SEE MINIMAL ACCUMULATION AS A RESULT OF LOWER ELEVATION AND
DOWNSLOPING WITH A GENERAL SOUTH WIND.
OVERALL PRECIP COVERAGE WILL DIMINISH SLOWLY AS THE SHIELD
PROGRESSES EASTWARD. HOWEVER...CONTINUED SOUTH TO SSW FLOW OFF LAKE
MI SHOULD YIELD A LAKE-ENHANCED BAND OF RAIN AND SNOW SHOWERS
ACROSS EASTERN DELTA INTO SCHOOLCRAFT COUNTIES. MEANWHILE...MINIMAL
FZDZ WILL BE POSSIBLE ACROSS THE FAR WEST LATE TONIGHT AS SOME
MID-LEVEL DRYING BEHIND THE SHORTWAVE LIMITS LIFT TO THE BARELY
SUB-FREEZING LOW-LEVELS.
THURSDAY...AN OVERALL LULL IN PRECIP IS EXPECTED THROUGH THURSDAY
MORNING BEHIND THE MID-LEVEL WAVE...BUT THE SFC TROUGH WILL BEGIN TO
TRACK ACROSS THE CWA DURING THE AFTERNOON ACROSS THE WEST. HIGH
TEMPS WILL BE FAIRLY EARLY IN THE DAY FOR THE WEST HALF...WITH
FALLING TEMPS THROUGHOUT THE AFTERNOON. HIGHER MOISTURE WITH THE
FRONT AND DROPPING TEMPS WILL INCREASE SNOW SHOWER COVERAGE
WEST...ESPECIALLY FOR THE HIGHER TERRAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 416 PM EST WED NOV 20 2013
SPLIT FLOW PATTERN PERSISTS THROUGH LATE THIS WEEK THEN FLOW PATTERN
BECOMES PHASED THIS WEEKEND INTO INTO FIRST PART OF NEXT WEEK WHICH
ALLOWS COLDEST AIR OF THE SEASON TO ARRIVE. COUPLE OF SHORTWAVES AND
SMALLER JET STREAKS LIFT ACROSS THURSDAY NIGHT INTO FRIDAY. BEST
CHANCE OF SYNOPTIC PRECIPITATION OCCURS THURSDAY NIGHT...ESPECIALLY
OVER THE SOUTH AND EAST. THOUGH THERE COULD BE SOME MIXED RAIN AND
SNOW EARLY THURSDAY EVENING IN THE EAST...SOUNDINGS AND THICKNESSES
BEYOND THAT TIME INDICATE COLD AIR WILL STAY IN PLACE LEADING TO SNOW
AS ONLY PTYPE THROUGH THE THANKSGIVING HOLIDAY.
MAY SEE ENHANCEMENT TO SNOW OVER THE WEST AND NORTH THURSDAY NIGHT
AS TEMPS AT INVERSION TOP OR H85 FALL TO -8C TO -10C GIVING A DELTA
T TO AROUND 13C. MORE SIGNIFICANT CONTRIBUTION FROM THE LAKE
ENHANCEMENT MAY BE OVER HIGHER TERRAIN OF NCNTRL AS LARGER SCALE
FORCING FOR SNOW PERSISTS INTO DAYBREAK ON FRIDAY. A FEW INCHES OF
SNOW MAY OCCUR OVER THURSDAY NIGHT FOR HIGHER TERRAIN OF MARQUETTE
COUNTY AND FOR FAVORED INLAND SNOWBELTS OF WESTERN ALGER COUNTY.
ELSEWHERE SNOW AMOUNTS OF AN INCH OR TWO ARE POSSIBLE.
ARCTIC FRONT WILL BE BLASTING SOUTH ACROSS MANITOBA AND NORTHERN
ONTARIO ON FRIDAY BUT WILL NOT ARRIVE OVER UPR LAKES UNTIL FRIDAY
EVENING. SO...FRIDAY MAY END UP A FAIRLY QUIET BTWN SYSTEMS DAY AS
CWA WILL BE IN WAKE OF THURSDAY NIGHT WAVE AND STILL AHEAD OF ARCTIC
FRONT/STRONG COLD AIR ADVECTION/LK EFFECT SNOWS FOR LATER FRIDAY
NIGHT INTO THE WEEKEND. PARTIAL CLEARING MAY OCCUR BUT WITH LIMITED
WARM AIR ADVECTION AHEAD OF THE FRONT...TEMPS WILL SILL END UP IN
THE 20S. WINDS WILL BE ON THE LIGHTER SIDE COMPARED TO THE WINDY
CONDITIONS COMING FOR THE WEEKEND.
ARCTIC FRONT SWEEPS THROUGH ON FRIDAY NIGHT. TEMPS STARTING OUT THE
EVENING IN THE UPR 20S WILL BE SOLIDLY IN THE TEENS OVER THE WEST BY
DAYBREAK ON SATURDAY AND GOING NOWHERE FAST. TEMPS WILL STAY STEADY
OR FALL SLIGHTLY ON SATURDAY AS PLUNGE OF COLD AIR AT H85 AND H7
DRIVES ACROSS THE GREAT LAKES REGION. EXPECT LK EFFECT SNOWS TO RAMP
UP SIGNIFICANTLY. INTITAL BURST OF SNOW OCCURS FRIDAY EVENING OVER
THE KEWEENAW WITH SUFFICIENT OVERWATER INSTABILITY COMBINING WITH
LOW-LEVEL CONVERGENCE ALONG FRONT. SOUNDINGS INDICATE FAVORABLE
MOISTURE AND LOCATION OF DGZ INTERSECTING PROJECTED UVM. SLR/S
SHOULD INCREASE TO MORE OF A FLUFFY 15-20:1 WITH STRONG NW WINDS IN
BLYR ONLY THING PROHIBITING SLR/S WELL OVER 20:1. ONCE BURST OF
HEAVIER SNOW SLIDES ACROSS CWA WITH THE ARCTIC FRONT...EXPECT
PERIOD OF HEAVY NNW FLOW LK EFFECT THROUGH THE DAY. NNW WINDS IN
BLYR AND A STILL OPEN LK NIPEGON COULD LEAD TO HEAVIEST SNOW
SHOWERS SETTING UP BTWN MQT AND MUNISING. SNOW TOTALS LATER
FRIDAY NIGHT THROUGH SATURDAY WILL BE AT LEAST ADVY ALONG MUCH OF
LK SUPERIOR WITH SOME AREAS SEEING WARNING AMOUNTS OF 10 INCHES IN
12 HOURS. STRONG WINDS WITH THE FLUFFIER SNOW WILL RESULT IN AREAS
OF BLOWING SNOW/REDUCED VSBY. PRETTY CONFIDENT HEADLINES FOR THIS
EVENT WILL BE COMING IN THE NEXT COUPLE DAYS. FOR NOW...WILL KEEP
GRAPHICAL MENTION IN THE EHWO AND A MENTION IN HAZARDOUS WEATHER
OUTLOOK.
DEPARTING DEEPER MOISTURE AND LOWERING INVERSIONS/INCREASING
ANTICYCLONIC FLOW WITH ARRIVAL OF SFC RIDGE WILL PUT A CRIMP IN LK
EFFECT BY SATURDAY NIGHT. STILL MAY SEE ADVY AMOUNTS OVER THE EAST
THOUGH AS OVERWATER INSTABILITY REMAINS MORE THAN SUFFICIENT AND
THERE WILL LIKELY BE SOME UPTICK OF LOW-LEVEL CONVERGENCE AS WINDS
BACK MORE WESTERLY OVR LAND WITH THE ARRIVAL OF THE SFC RIDGE TOWARD
WESTERN UPR MICHIGAN. TRANSITION ON SUNDAY AS SFC RIDGE CROSSES.
COULD BE TRICKY SINCE COLD AIR LINGERS AND WINDS BECOME FAVORABLE
FOR LK EFFECT OFF LK MICHIGAN. INITIALLY WINDS HAVE ENOUGH SOUTHERLY
COMPONENT TO INCLUDE HIGHER POPS OVER MUCH OF SCHOOLCRAFT AND LUCE
COUNTIES...THEN EVENTUALLY ON SUNDAY NIGHT THE WINDS HAVE ENOUGH OF
A WESTERLY COMPONENT TO PUSH MOST OF MORE SIGNIFICANT LK EFFECT
FARTHER TO THE EAST. HOWEVER...CLIPPER LOW PRESSURE SYSTEM DROPPING
TO NORTH OF LK SUPERIOR WILL SPREAD ADDITIONAL SNOW ACROSS NORTHERN
AND EASTERN UPR MICHIGAN.
ANOTHER BOUT OF COLD AIR AND LK EFFECT LIKELY IN WAKE OF THAT
CLIPPER TUESDAY AND WEDNESDAY. ONCE AGAIN AREAS FAVORED BY NNW
FLOW OVER CNTRL AND EASTERN CWA WILL SEE THE BEST SHOT AT HEAVIER
SNOW. PLENTY OF TIME TO ASSESS THIS POTENTIAL ONCE WE GET PAST THE
WEEKEND LK EFFECT SNOWS. PEEK AHEAD TO THANKSGIVING SHOWS THE COLD
AIR PERSISTS WHILE LINGERING LK EFFECT RUNS ITS COURSE. SO...AT
LEAST AT THIS POINT...NO LARGE SCALE LOW PRESSURE SYSTEM/WIDESPREAD
SNOW EXPECTED FOR THE THANKSGIVING TIME FRAME. PROBABLY GOES WITHOUT
SAYING...BUT OBVIOUSLY THERE IS PLENTY OF TIME FOR THIS TO CHANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED NOV 20 2013
LIGHT SNOW WILL MOVE OUT THIS MORNING WITH CONDITIONS SLOWLY
IMPROVING. IFR CIGS SHOULD DEVELOP AT IWD AND SAW OVERNIGHT AS WINDS
BECOME MORE SSW AND LOW-LEVEL MOISTURE INCREASES BEHIND THE PRECIP.
ALL SITES SHOULD SEE SOME CIG IMPROVEMENT THURSDAY MORNING WITH SOME
LOW-LEVEL DRYING AND MINIMAL LIFT. THE EXCEPTION WILL BE CMX...WHERE
AN APPROACHING COLD FRONT WILL BRING NW WINDS AND INCREASINGLY
UPSLOPE FLOW. LAKE EFFECT SNOW SHOWERS AND MVFR CONDITIONS EXPECTED
AT ALL TAF SITES THU AFTERNOON WHICH WILL REMAIN THROUGH THU EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST WED NOV 20 2013
SOUTHERLY WINDS OF UP TO 30 KNOTS FOR EASTERN LAKE SUPERIOR LATE
THIS AFTERNOON WILL DIMINISH TO LESS THAN 20 KNOTS BY THURSDAY
MORNING AS A COLD FRONT NEARS WESTERN LAKE SUPERIOR. THE COLD FRONT
IS EXPECTED TO CROSS LAKE SUPERIOR BEGINNING FAR WEST MID-THURSDAY
MORNING...AND REACHING THE FAR EAST THURSDAY EVENING. WINDS WILL
QUICKLY VEER TO THE NW AROUND 30 KNOTS FOR MUCH OF LAKE SUPERIOR
BEHIND THE FRONT. EXPECT THESE WINDS TO CONTINUE THROUGH THURSDAY
EVENING BEFORE DIMINISHING ON FRIDAY.
STRONG HIGH PRESSURE BUILDING ACROSS CENTRAL CANADA WILL BEGIN TO
IMPINGE ON LOW PRESSURE DEVELOPING OVER THE LOWER GREAT LAKES FRIDAY
AFTERNOON AND EVENING. WEST WINDS OF 20-30 KNOTS ACROSS WESTERN LAKE
SUPERIOR FRIDAY EVENING WILL BECOME NW GALES TO 35 KNOTS WEST TO NW
GALES TO 45 KNOTS EAST SATURDAY MORNING. THE WINDS WILL GRADUALLY
DIMINISH TO UNDER 20 KNOTS BY SUNDAY MORNING. WITH ARCTIC AIR MOVING
OVER THE LAKE...THERE IS A POTENTIAL FOR WIDESPREAD FREEZING SPRAY
SATURDAY AND SATURDAY NIGHT. THEN AN APPROACHING LOW PRESSURE FROM
CANADA WILL BACK WINDS SW TO 20-30 KNOTS BY MONDAY MORNING. ANOTHER
COLD FRONT WILL FOLLOW MONDAY AFTERNOON WITH 20-30 KNOTS NW WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY NIGHT
FOR LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KLUBER
LONG TERM...JLA
AVIATION...07
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1201 PM CST THU NOV 21 2013
.DISCUSSION...
HAVE ISSUED A WINTER WEATHER ADVISORY FROM SOUTHEAST NEB TO
SOUTHWEST/WEST CENTRAL IA. LIGHT FREEZING RAIN IS ACCUMULATING ON
ELEVATED SURFACES...AND EVEN ON SOME ROADWAYS. SLEET HAS BEGUN TO
MIX IN...WHICH WILL AT LEAST PUT A DAMPER ON THE ICING..BUT COULD
ALSO KEEP ROADS ON THE SLICK SIDE. PRECIPITATION SHOULD TRANSITION
TO SLEET AND SNOW THROUGH THE AFTERNOON...BUT OVERALL...RISK OF
HAZARDOUS TRAVEL WAS HIGH ENOUGH IN BAND OF HEAVIEST PRECIPITATION
TO WARRANT A HEADLINE.
MAYES
&&
.PREV DISCUSSION... /ISSUED 1127 AM CST THU NOV 21 2013/
AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK
MESSY CONDITIONS ARE LARGELY FOCUSED ON THE FIRST 12 HOURS OF THE
TAF PERIOD. PERIODS OF MVFR CEILINGS MAY BECOME IFR OR EVEN LIFR
IN SNOWY AREAS LATER THIS EVENING. AT KOMA/KLNK...HAVE INCLUDED A
TEMPO MENTION OF LIGHT FREEZING RAIN FROM 18-20Z...WITH LIGHT
FREEZING RAIN REPORTS IN BOTH METRO AREAS ALREADY...THEN A MIX OF
SLEET AND SNOW LATER THIS AFTERNOON AS PRECIPITATION CHANGES OVER.
MOST LIKELY PERIOD FOR MODERATE SNOWFALL RATES WOULD BE 00-06Z AT
KOMA/KLNK...AND AROUND 22-04Z AT KOFK. GUSTY NORTH WINDS WILL
CONTINUE THROUGH AROUND 06Z AS WELL. SNOW WILL END AND CEILINGS
WILL SCATTER OUT AROUND OR SHORTLY AFTER MIDNIGHT...WITH WINDS
AROUND 12-15KT CONTINUING THROUGH MUCH OF THE NIGHT BEFORE
DIMINISHING IN THE MORNING.
MAYES
PREV DISCUSSION... /ISSUED 1047 AM CST THU NOV 21 2013/
DISCUSSION...
A BAND OF LIGHT PRECIPITATION HAS DEVELOPED IN SOUTHEAST NEBRASKA.
TEMPERATURES ARE FALLING BELOW FREEZING FASTER THAN MOST MODELS
HAD PROGGED...AND HAVE UPDATED TEMPERATURES FOR A FASTER FALL THIS
MORNING...LEVELING OFF SOMEWHAT TODAY BEFORE FALLING AGAIN THIS
EVENING. RAP ANALYSIS INDICATES A WARM NOSE ABOVE THE
SURFACE...WITH ABOVE-FREEZING TEMPERATURES AROUND 850-700 MB STILL
IN PLACE IN MOST AREAS SOUTH OF I-80. UPDATED PRECIPITATION TYPES
TO INCLUDE MORE OF A FREEZING RAIN MENTION IN THE SOUTHEAST
CWA...BEFORE MIXING WITH AND CHANGING TO SLEET IN THE EARLY
TO MID AFTERNOON. REPORTS INDICATE SOME LIGHT ICE ACCUMULATION ON
ELEVATED SURFACES /I.E. WINDOWS AND VEHICLES/ BUT NOT YET ON
ROADS...THUS WILL STICK WITH AN SPS FOR NOW TO HIGHLIGHT THE
BRIEF/LIGHT FREEZING RAIN.
MAYES
PREV DISCUSSION... /ISSUED 423 AM CST THU NOV 21 2013/
DISCUSSION...
THE BULK OF THE WEATHER WILL BE IN THE FIRST 36HRS OF THE
FORECAST WITH THE MAIN FORECAST CONCERNS ONSET OF PRECIPITATION
AND PRECIPITATION TYPE AND SNOWFALL AMOUNTS.
LATEST SATELLITE AND RADAR TRENDS SHOW ENHANCED CLOUDS QUICKLY
LIFTING NORTHEAST THIS MORNING ACROSS KANSAS AND MISSOURI. THE
WSR-88D RADAR HAD A BAND OF RAIN FROM HAYS TO EMPORIA INTO
SOUTHEAST KANSAS...SHIFTING EAST AND LIFTING NORTHEAST. AT THE
SURFACE...ALL SITES HAD NORTH WINDS...WITH THE GUSTY WINDS TO A
NEBRASKA CITY RED OAK LINE. TEMPERATURES WERE IN THE LOWER 20S
NORTH TO 40 SOUTH.
COMPLEX PATTERN TODAY RESULTING FROM SPLIT FLOW REGIME. A SHORTWAVE
TROF ENERGY WITHIN THE LONGWAVE TROF PASSES TO OUR SOUTH THIS
MORNING. 40M HT FALLS WERE NOTED WITH THE CA H5 TROF AND A 100-140KT
JET EXTENDED FROM OFF THE CAL COAST INTO SOUTHERN ARIZONA. THE
FORECAST AREA IS UNDER THE INFLUENCE OF THESE WEATHER
SYSTEMS...HOWEVER THE FORCING IS WEAKER DUE TO THE LACK OF FOCUS.
THIS MORNING...AS THE H3 JET MOVES INTO KANSAS AND MISSOURI...UPPER
LEVEL DIVERGENCE IN THE LEFT EXIT REGION OVER THE AREA QUICKLY MOVES
INTO ILLINOIS BY 18Z. THE H5 LOW CLOSES OFF OVER SOUTHERN CALIFORNIA
THIS AFTERNOON...MEANWHILE...ENERGY FROM THE NORTHERN STREAM MOVES
THROUGH THE NORTHERN PLAINS WITH UPPER LEVEL DIVERGENCE FROM THE
RIGHT ENTRANCE REGION OF THE JET INCREASING OVER THE WESTERN PLAINS.
THERE IS SOME FRONTOGENESIS OVER CENTRAL NEBRASKA THIS
MORNING...THEN LIFTS BACK TO THE NORTHWEST BY MIDDAY...IS FAIRLY
WEAK IN NORTHEAST NEBRASKA THIS AFTERNOON THEN STRENGTHENS AND MOVES
THROUGH THE REST OF THE FORECAST AREA TONIGHT.
HAVE LOWERED POPS FOR MUCH OF THE FORECAST AREA THIS MORNING AS
THE BEST CHANCE FOR MEASURABLE PRECIPITATION LOOKS TO BE SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA. ALTHOUGH THE GFS/EC HAVE SOME TENTH
OF AN INCH PRECIP AMOUNTS IN THE SOUTHEAST NEBRASKA...HI
RESOLUTION HRRR/RAP/NAM ARE A BIT DRIER. THE NAM SEEMED TO HAVE
THE BEST HANDLE ON THE LOW LEVEL TEMPS AND DEWPOINTS. THE GFS/EC
WERE WAY TOO MOIST. FOR THIS PACKAGE LEANED TOWARD THE
NAM/HOPWRF/4KM WRF. HAVE HIGHER POPS SOUTH OF A BEATRICE TO RED
OAK LINE THIS MORNING WITH SLIGHT CHANCES FARTHER NORTH TOWARD
OMAHA. DUE TO THE COLD AIR...FORECAST SOUNDINGS AND TIMESECTIONS
SHOW A MIX OF PRECIP TYPES. WHERE THE PRECIPITATION IS EXPECTED
TO ACCUMULATE...IT SHOULD BE MAINLY RAIN...HOWEVER THERE COULD BE
A MIX FARTHER NORTH IN THE COLDER AIR. DID NOT ISSUE ANY HEADLINES
DUE TO LOW CONFIDENCE IN EXTENT OF ACCUMULATION OF ANY MIXED
PRECIPITATION. NORTHWEST WINDS AT 20 TO 30 MPH SUSTAINED WILL
CONTINUE AND TEMPERATURES WILL NOT GO ANYWHERE...HOLDING MAINLY IN
THE 20S NORTH AND 30S SOUTH.
THIS AFTERNOON...THE COLD AIR WILL BECOME DEEPER AND SNOW IS
EXPECTED TO DEVELOP OVER NORTHERN NEBRASKA WITH THE NORTHERN
STREAM TROF...WITH AREA OF PRECIPITATION OVER FAR SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA SHIFTING EASTWARD. LIGHT SNOW SHOULD
THEN OVERSPREAD THE AREA...MOVING OUT OF THE FORECAST AREA AFTER
06Z. DUE TO THE SHORTER DURATION OF PRECIPITATION HAVE LOWERED
AMOUNTS AND THEY NOW AVERAGE A TRACE TO 1.5 INCHES.
SURFACE HIGH PRESSURE WILL BUILD IN FRIDAY THEN A REINFORCING SHOT
OF COLD AIR SATURDAY. THE ARCTIC FRONT MOVES THROUGH SATURDAY WITH
THE BRUNT OF THE COLD AIR SLIDING TO OUR EAST OVER IOWA AND THE
GREAT LAKES AS THE MID LEVEL TROF DIG INTO THE EASTERN U.S. BY
SUNDAY...SOUTHWEST FLOW WILL RETURN AND TEMPERATURES WILL
RECOVER...BUT WILL REMAIN WELL BELOW NORMAL. THE STORM SYSTEM OVER
THE SOUTHWEST U.S. WILL SHIFT TOWARD THE FOUR CORNERS REGION AND
PRECIP CHANCES MAY BE NEEDED SUNDAY NIGHT INTO MONDAY. ANY
PRECIPITATION LOOKS TO BE LIGHT AND MAY NOT MEASURE. MONDAY ANOTHER
WEAK COLD FRONT MOVES THROUGH WITH A MID LEVEL TROF MOVING THROUGH
THE GREAT LAKES AND THE CLOSE LOW SLOWLY TRACKING ACROSS THE
SOUTHERN PLAINS. THERE ARE SOME AMPLITUDE DIFFERENCE IN THE H5
PATTERN BY WEDNESDAY. THE EC HAS A SHARPENING TROF OVER THE GREAT
LAKES WITH BACKDOOR COOLING...WHILE THE GFS IS FLATTER WITH WARMING
AHEAD OF A WEAK FRONT.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NEZ067-
068-088>093.
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ056-
069-079-080-090-091.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1127 AM CST THU NOV 21 2013
.AVIATION...
MESSY CONDITIONS ARE LARGELY FOCUSED ON THE FIRST 12 HOURS OF THE
TAF PERIOD. PERIODS OF MVFR CEILINGS MAY BECOME IFR OR EVEN LIFR
IN SNOWY AREAS LATER THIS EVENING. AT KOMA/KLNK...HAVE INCLUDED A
TEMPO MENTION OF LIGHT FREEZING RAIN FROM 18-20Z...WITH LIGHT
FREEZING RAIN REPORTS IN BOTH METRO AREAS ALREADY...THEN A MIX OF
SLEET AND SNOW LATER THIS AFTERNOON AS PRECIPITATION CHANGES
OVER. MOST LIKELY PERIOD FOR MODERATE SNOWFALL RATES WOULD BE
00-06Z AT KOMA/KLNK...AND AROUND 22-04Z AT KOFK. GUSTY NORTH WINDS
WILL CONTINUE THROUGH AROUND 06Z AS WELL. SNOW WILL END AND
CEILINGS WILL SCATTER OUT AROUND OR SHORTLY AFTER MIDNIGHT...WITH
WINDS AROUND 12-15KT CONTINUING THROUGH MUCH OF THE NIGHT BEFORE
DIMINISHING IN THE MORNING.
MAYES
&&
.PREV DISCUSSION... /ISSUED 1047 AM CST THU NOV 21 2013/
DISCUSSION...
A BAND OF LIGHT PRECIPITATION HAS DEVELOPED IN SOUTHEAST NEBRASKA.
TEMPERATURES ARE FALLING BELOW FREEZING FASTER THAN MOST MODELS
HAD PROGGED...AND HAVE UPDATED TEMPERATURES FOR A FASTER FALL THIS
MORNING...LEVELING OFF SOMEWHAT TODAY BEFORE FALLING AGAIN THIS
EVENING. RAP ANALYSIS INDICATES A WARM NOSE ABOVE THE
SURFACE...WITH ABOVE-FREEZING TEMPERATURES AROUND 850-700 MB STILL
IN PLACE IN MOST AREAS SOUTH OF I-80. UPDATED PRECIPITATION TYPES
TO INCLUDE MORE OF A FREEZING RAIN MENTION IN THE SOUTHEAST
CWA...BEFORE MIXING WITH AND CHANGING TO SLEET IN THE EARLY
TO MID AFTERNOON. REPORTS INDICATE SOME LIGHT ICE ACCUMULATION ON
ELEVATED SURFACES /I.E. WINDOWS AND VEHICLES/ BUT NOT YET ON
ROADS...THUS WILL STICK WITH AN SPS FOR NOW TO HIGHLIGHT THE
BRIEF/LIGHT FREEZING RAIN.
MAYES
PREV DISCUSSION... /ISSUED 423 AM CST THU NOV 21 2013/
DISCUSSION...
THE BULK OF THE WEATHER WILL BE IN THE FIRST 36HRS OF THE
FORECAST WITH THE MAIN FORECAST CONCERNS ONSET OF PRECIPITATION
AND PRECIPITATION TYPE AND SNOWFALL AMOUNTS.
LATEST SATELLITE AND RADAR TRENDS SHOW ENHANCED CLOUDS QUICKLY
LIFTING NORTHEAST THIS MORNING ACROSS KANSAS AND MISSOURI. THE
WSR-88D RADAR HAD A BAND OF RAIN FROM HAYS TO EMPORIA INTO
SOUTHEAST KANSAS...SHIFTING EAST AND LIFTING NORTHEAST. AT THE
SURFACE...ALL SITES HAD NORTH WINDS...WITH THE GUSTY WINDS TO A
NEBRASKA CITY RED OAK LINE. TEMPERATURES WERE IN THE LOWER 20S
NORTH TO 40 SOUTH.
COMPLEX PATTERN TODAY RESULTING FROM SPLIT FLOW REGIME. A SHORTWAVE
TROF ENERGY WITHIN THE LONGWAVE TROF PASSES TO OUR SOUTH THIS
MORNING. 40M HT FALLS WERE NOTED WITH THE CA H5 TROF AND A 100-140KT
JET EXTENDED FROM OFF THE CAL COAST INTO SOUTHERN ARIZONA. THE
FORECAST AREA IS UNDER THE INFLUENCE OF THESE WEATHER
SYSTEMS...HOWEVER THE FORCING IS WEAKER DUE TO THE LACK OF FOCUS.
THIS MORNING...AS THE H3 JET MOVES INTO KANSAS AND MISSOURI...UPPER
LEVEL DIVERGENCE IN THE LEFT EXIT REGION OVER THE AREA QUICKLY MOVES
INTO ILLINOIS BY 18Z. THE H5 LOW CLOSES OFF OVER SOUTHERN CALIFORNIA
THIS AFTERNOON...MEANWHILE...ENERGY FROM THE NORTHERN STREAM MOVES
THROUGH THE NORTHERN PLAINS WITH UPPER LEVEL DIVERGENCE FROM THE
RIGHT ENTRANCE REGION OF THE JET INCREASING OVER THE WESTERN PLAINS.
THERE IS SOME FRONTOGENESIS OVER CENTRAL NEBRASKA THIS
MORNING...THEN LIFTS BACK TO THE NORTHWEST BY MIDDAY...IS FAIRLY
WEAK IN NORTHEAST NEBRASKA THIS AFTERNOON THEN STRENGTHENS AND MOVES
THROUGH THE REST OF THE FORECAST AREA TONIGHT.
HAVE LOWERED POPS FOR MUCH OF THE FORECAST AREA THIS MORNING AS
THE BEST CHANCE FOR MEASURABLE PRECIPITATION LOOKS TO BE SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA. ALTHOUGH THE GFS/EC HAVE SOME TENTH
OF AN INCH PRECIP AMOUNTS IN THE SOUTHEAST NEBRASKA...HI
RESOLUTION HRRR/RAP/NAM ARE A BIT DRIER. THE NAM SEEMED TO HAVE
THE BEST HANDLE ON THE LOW LEVEL TEMPS AND DEWPOINTS. THE GFS/EC
WERE WAY TOO MOIST. FOR THIS PACKAGE LEANED TOWARD THE
NAM/HOPWRF/4KM WRF. HAVE HIGHER POPS SOUTH OF A BEATRICE TO RED
OAK LINE THIS MORNING WITH SLIGHT CHANCES FARTHER NORTH TOWARD
OMAHA. DUE TO THE COLD AIR...FORECAST SOUNDINGS AND TIMESECTIONS
SHOW A MIX OF PRECIP TYPES. WHERE THE PRECIPITATION IS EXPECTED
TO ACCUMULATE...IT SHOULD BE MAINLY RAIN...HOWEVER THERE COULD BE
A MIX FARTHER NORTH IN THE COLDER AIR. DID NOT ISSUE ANY HEADLINES
DUE TO LOW CONFIDENCE IN EXTENT OF ACCUMULATION OF ANY MIXED
PRECIPITATION. NORTHWEST WINDS AT 20 TO 30 MPH SUSTAINED WILL
CONTINUE AND TEMPERATURES WILL NOT GO ANYWHERE...HOLDING MAINLY IN
THE 20S NORTH AND 30S SOUTH.
THIS AFTERNOON...THE COLD AIR WILL BECOME DEEPER AND SNOW IS
EXPECTED TO DEVELOP OVER NORTHERN NEBRASKA WITH THE NORTHERN
STREAM TROF...WITH AREA OF PRECIPITATION OVER FAR SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA SHIFTING EASTWARD. LIGHT SNOW SHOULD
THEN OVERSPREAD THE AREA...MOVING OUT OF THE FORECAST AREA AFTER
06Z. DUE TO THE SHORTER DURATION OF PRECIPITATION HAVE LOWERED
AMOUNTS AND THEY NOW AVERAGE A TRACE TO 1.5 INCHES.
SURFACE HIGH PRESSURE WILL BUILD IN FRIDAY THEN A REINFORCING SHOT
OF COLD AIR SATURDAY. THE ARCTIC FRONT MOVES THROUGH SATURDAY WITH
THE BRUNT OF THE COLD AIR SLIDING TO OUR EAST OVER IOWA AND THE
GREAT LAKES AS THE MID LEVEL TROF DIG INTO THE EASTERN U.S. BY
SUNDAY...SOUTHWEST FLOW WILL RETURN AND TEMPERATURES WILL
RECOVER...BUT WILL REMAIN WELL BELOW NORMAL. THE STORM SYSTEM OVER
THE SOUTHWEST U.S. WILL SHIFT TOWARD THE FOUR CORNERS REGION AND
PRECIP CHANCES MAY BE NEEDED SUNDAY NIGHT INTO MONDAY. ANY
PRECIPITATION LOOKS TO BE LIGHT AND MAY NOT MEASURE. MONDAY ANOTHER
WEAK COLD FRONT MOVES THROUGH WITH A MID LEVEL TROF MOVING THROUGH
THE GREAT LAKES AND THE CLOSE LOW SLOWLY TRACKING ACROSS THE
SOUTHERN PLAINS. THERE ARE SOME AMPLITUDE DIFFERENCE IN THE H5
PATTERN BY WEDNESDAY. THE EC HAS A SHARPENING TROF OVER THE GREAT
LAKES WITH BACKDOOR COOLING...WHILE THE GFS IS FLATTER WITH WARMING
AHEAD OF A WEAK FRONT.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1047 AM CST THU NOV 21 2013
.DISCUSSION...
A BAND OF LIGHT PRECIPITATION HAS DEVELOPED IN SOUTHEAST NEBRASKA.
TEMPERATURES ARE FALLING BELOW FREEZING FASTER THAN MOST MODELS
HAD PROGGED...AND HAVE UPDATED TEMPERATURES FOR A FASTER FALL THIS
MORNING...LEVELING OFF SOMEWHAT TODAY BEFORE FALLING AGAIN THIS
EVENING. RAP ANALYSIS INDICATES A WARM NOSE ABOVE THE
SURFACE...WITH ABOVE-FREEZING TEMPERATURES AROUND 850-700 MB STILL
IN PLACE IN MOST AREAS SOUTH OF I-80. UPDATED PRECIPITATION TYPES
TO INCLUDE MORE OF A FREEZING RAIN MENTION IN THE SOUTHEAST
CWA...BEFORE MIXING WITH AND CHANGING TO SLEET IN THE EARLY
TO MID AFTERNOON. REPORTS INDICATE SOME LIGHT ICE ACCUMULATION ON
ELEVATED SURFACES /I.E. WINDOWS AND VEHICLES/ BUT NOT YET ON
ROADS...THUS WILL STICK WITH AN SPS FOR NOW TO HIGHLIGHT THE
BRIEF/LIGHT FREEZING RAIN.
MAYES
&&
.PREV DISCUSSION... /ISSUED 532 AM CST THU NOV 21 2013/
AVIATION...12Z TAFS FOR KOFK...KLNK AND KOMA.
MVFR CIGS AND NORTH WINDS 20 TO 30KT CAN BE EXPECTED INTO THE
AFTERNOON WITH PRECIPITATION STAYING TO THE NORTH AND SOUTH OF TAF
SITES. IN THE 20Z TO 00Z TIMEFRAME...LIGHT SNOW WILL BEGIN TO
DEVELOP AND COULD BECOME MODERATE AT TIMES BETWEEN 00Z AND 06Z.
CIGS WILL FALL TO BELOW FL010 WITH VSBYS BETWEEN 1 AND 2 MILES AT
TIMES. ISOLATED VSBYS BELOW A MILE ARE CERTAINLY POSSIBLE...AND A
BRIEF MIX OF SLEET COULD OCCUR AT KLNK AND KOMA BEFORE 00Z. THE
SNOW SHOULD MOVE EAST OF TAF SITES BETWEEN 06Z AND 09Z WITH THE
NORTH WINDS DECREASING TO 15KT. CIGS WILL LIKELY LIFT TO VFR
BEFORE THE END OF THE TAF PERIOD.
DERGAN
PREV DISCUSSION... /ISSUED 423 AM CST THU NOV 21 2013/
DISCUSSION...
THE BULK OF THE WEATHER WILL BE IN THE FIRST 36HRS OF THE
FORECAST WITH THE MAIN FORECAST CONCERNS ONSET OF PRECIPITATION
AND PRECIPITATION TYPE AND SNOWFALL AMOUNTS.
LATEST SATELLITE AND RADAR TRENDS SHOW ENHANCED CLOUDS QUICKLY
LIFTING NORTHEAST THIS MORNING ACROSS KANSAS AND MISSOURI. THE
WSR-88D RADAR HAD A BAND OF RAIN FROM HAYS TO EMPORIA INTO
SOUTHEAST KANSAS...SHIFTING EAST AND LIFTING NORTHEAST. AT THE
SURFACE...ALL SITES HAD NORTH WINDS...WITH THE GUSTY WINDS TO A
NEBRASKA CITY RED OAK LINE. TEMPERATURES WERE IN THE LOWER 20S
NORTH TO 40 SOUTH.
COMPLEX PATTERN TODAY RESULTING FROM SPLIT FLOW REGIME. A SHORTWAVE
TROF ENERGY WITHIN THE LONGWAVE TROF PASSES TO OUR SOUTH THIS
MORNING. 40M HT FALLS WERE NOTED WITH THE CA H5 TROF AND A 100-140KT
JET EXTENDED FROM OFF THE CAL COAST INTO SOUTHERN ARIZONA. THE
FORECAST AREA IS UNDER THE INFLUENCE OF THESE WEATHER
SYSTEMS...HOWEVER THE FORCING IS WEAKER DUE TO THE LACK OF FOCUS.
THIS MORNING...AS THE H3 JET MOVES INTO KANSAS AND MISSOURI...UPPER
LEVEL DIVERGENCE IN THE LEFT EXIT REGION OVER THE AREA QUICKLY MOVES
INTO ILLINOIS BY 18Z. THE H5 LOW CLOSES OFF OVER SOUTHERN CALIFORNIA
THIS AFTERNOON...MEANWHILE...ENERGY FROM THE NORTHERN STREAM MOVES
THROUGH THE NORTHERN PLAINS WITH UPPER LEVEL DIVERGENCE FROM THE
RIGHT ENTRANCE REGION OF THE JET INCREASING OVER THE WESTERN PLAINS.
THERE IS SOME FRONTOGENESIS OVER CENTRAL NEBRASKA THIS
MORNING...THEN LIFTS BACK TO THE NORTHWEST BY MIDDAY...IS FAIRLY
WEAK IN NORTHEAST NEBRASKA THIS AFTERNOON THEN STRENGTHENS AND MOVES
THROUGH THE REST OF THE FORECAST AREA TONIGHT.
HAVE LOWERED POPS FOR MUCH OF THE FORECAST AREA THIS MORNING AS
THE BEST CHANCE FOR MEASURABLE PRECIPITATION LOOKS TO BE SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA. ALTHOUGH THE GFS/EC HAVE SOME TENTH
OF AN INCH PRECIP AMOUNTS IN THE SOUTHEAST NEBRASKA...HI
RESOLUTION HRRR/RAP/NAM ARE A BIT DRIER. THE NAM SEEMED TO HAVE
THE BEST HANDLE ON THE LOW LEVEL TEMPS AND DEWPOINTS. THE GFS/EC
WERE WAY TOO MOIST. FOR THIS PACKAGE LEANED TOWARD THE
NAM/HOPWRF/4KM WRF. HAVE HIGHER POPS SOUTH OF A BEATRICE TO RED
OAK LINE THIS MORNING WITH SLIGHT CHANCES FARTHER NORTH TOWARD
OMAHA. DUE TO THE COLD AIR...FORECAST SOUNDINGS AND TIMESECTIONS
SHOW A MIX OF PRECIP TYPES. WHERE THE PRECIPITATION IS EXPECTED
TO ACCUMULATE...IT SHOULD BE MAINLY RAIN...HOWEVER THERE COULD BE
A MIX FARTHER NORTH IN THE COLDER AIR. DID NOT ISSUE ANY HEADLINES
DUE TO LOW CONFIDENCE IN EXTENT OF ACCUMULATION OF ANY MIXED
PRECIPITATION. NORTHWEST WINDS AT 20 TO 30 MPH SUSTAINED WILL
CONTINUE AND TEMPERATURES WILL NOT GO ANYWHERE...HOLDING MAINLY IN
THE 20S NORTH AND 30S SOUTH.
THIS AFTERNOON...THE COLD AIR WILL BECOME DEEPER AND SNOW IS
EXPECTED TO DEVELOP OVER NORTHERN NEBRASKA WITH THE NORTHERN
STREAM TROF...WITH AREA OF PRECIPITATION OVER FAR SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA SHIFTING EASTWARD. LIGHT SNOW SHOULD
THEN OVERSPREAD THE AREA...MOVING OUT OF THE FORECAST AREA AFTER
06Z. DUE TO THE SHORTER DURATION OF PRECIPITATION HAVE LOWERED
AMOUNTS AND THEY NOW AVERAGE A TRACE TO 1.5 INCHES.
SURFACE HIGH PRESSURE WILL BUILD IN FRIDAY THEN A REINFORCING SHOT
OF COLD AIR SATURDAY. THE ARCTIC FRONT MOVES THROUGH SATURDAY WITH
THE BRUNT OF THE COLD AIR SLIDING TO OUR EAST OVER IOWA AND THE
GREAT LAKES AS THE MID LEVEL TROF DIG INTO THE EASTERN U.S. BY
SUNDAY...SOUTHWEST FLOW WILL RETURN AND TEMPERATURES WILL
RECOVER...BUT WILL REMAIN WELL BELOW NORMAL. THE STORM SYSTEM OVER
THE SOUTHWEST U.S. WILL SHIFT TOWARD THE FOUR CORNERS REGION AND
PRECIP CHANCES MAY BE NEEDED SUNDAY NIGHT INTO MONDAY. ANY
PRECIPITATION LOOKS TO BE LIGHT AND MAY NOT MEASURE. MONDAY ANOTHER
WEAK COLD FRONT MOVES THROUGH WITH A MID LEVEL TROF MOVING THROUGH
THE GREAT LAKES AND THE CLOSE LOW SLOWLY TRACKING ACROSS THE
SOUTHERN PLAINS. THERE ARE SOME AMPLITUDE DIFFERENCE IN THE H5
PATTERN BY WEDNESDAY. THE EC HAS A SHARPENING TROF OVER THE GREAT
LAKES WITH BACKDOOR COOLING...WHILE THE GFS IS FLATTER WITH WARMING
AHEAD OF A WEAK FRONT.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
232 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHEAST UNITED STATES WILL MOVE OFF THE
COAST TONIGHT AND LEAD TO A SOUTHERLY FLOW OF MILDER AIR FOR
THURSDAY. A WARM FRONT WITH RAIN SHOWERS WILL MOVE THROUGH THE
REGION THURSDAY NIGHT AND FRIDAY. A STRONG COLD FRONT WILL MOVE
THROUGH THE REGION FRIDAY NIGHT, WHICH WILL USHER IN MUCH COLDER
AIR STARTING SUNDAY. THIS COLD AIR COULD GENERATE SIGNIFICANT
LAKE EFFECT SNOWS IN THE LAKE EFFECT SNOW BELTS OF NORTH CENTRAL
NEW YORK.
&&
.NEAR TERM /THROUGH TODAY/...
745 PM UPDATE... ONLY MINOR TWEAKS WERE MADE TO THE GRIDS EARLY
THIS EVE...WITH OUR EXISTING FCST IN GOOD SHAPE.
SAT IMAGERY/SFC OBS ARE SHOWING THIN HIGH CLDNS CROSSING CNY/NE PA
THIS EVE. GIVEN SAT TRENDS UPSTREAM...WE THINK WE`LL CONTINUE TO
SEE SOME HIGH CLOUD COVER OVERNIGHT...BUT GIVEN ITS FAIRLY
TRANSPARENT NATURE...PTLY CLDY SEEMS LIKE A GOOD SKY COVER
DESCRIPTOR. THERE WAS SOME THINKING EARLIER TDY THAT A MARINE LYR
CLOUD DECK COULD SNEAK UP INTO OUR SERN ZNS BY...OR JUST AFTER
09Z THU. ALTHOUGH THERE IS SOME PATCHY SC ATTM ACRS SRN VA...WE
THINK THAT LWR CLDS WILL NOT MAKE IT TO NE PA BY DAYBREAK FOR SVRL
REASONS...LACK OF CLOUD DVLPMT/ONSHORE FLOW ATTM OVER MOST OF THE
DELMARVA RGN OR NJ...WEAK LOW-LVL FLOW...AND A VERY DRY RESIDENT
AMS IN THE BLYR (SFC DEW PTS NEAR 10F OVER MUCH OF ERN PA ATTM).
WE STILL FEEL CONFIDENT SOME OF OUR NORMALLY COLDER SHELTERED VLYS
WILL DROP INTO THE TEENS BY DAYBREAK. AS A RESULT...WE BASICALLY
LEFT OUR LOW TEMP FCST ALONE...AND JUST MASSAGED SOME NEAR-TERM
TEMPS AND DEW PTS THIS EVE.
PREV DISC... HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S INTO
THIS EVENING AS THE UPPER LEVEL RDG AXIS SLOWLY MOVES E. EXPECT
ONLY SOME PATCHY CIRRUS AT TIMES WORKG OVER THE UPR LVL RDG AXIS
WHICH WILL BE MOVG OVHD THIS EVE. OTHERWISE FAIR WX THIS EVENING.
FOR OVERNIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12..12Z CMC AND RUC13 AS WELL AS THE LATEST 12Z GFS
ALL SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE
MIDDLE ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING
NORTHWARD REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS
LAYER FARTHER S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS
REACHING NRN PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM/GFS
AND CMC.
ON THURSDAY THERE WILL BE A SOUTHERLY RETURN FLOW SETTING UP AS
THE SFC HIGH IS OFFSHORE. THE 925 MB TO 850 MB WINDS WILL BE FROM
THE SOUTH AND BASED ON THE LATEST NAM...GFS AND CMC MODELS LL
MOISTURE WILL BE ON THE INCREASE THURSDAY AS CIRRUS AND MID CLDS
POUR IN FROM THE WEST AS HI LEVEL THERMAL ADVECTIONS BEGIN IN
ADVANCE OF THE NEXT SYSTEM. THEREFORE WILL HAVE INCREASING AMNTS
OF CLDS DURING THE DAY THURSDAY. LOOKS LIKE ANY PRECIP WILL HOLD
OFF B4 00Z FRI.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
FOR THURSDAY NIGHT...AN UPPER LEVEL JET STREAK WITH THE NEXT
SYSTEM WILL PUSH INTO THE LOWER LAKES/UPR OH VLLY AND SUPPORT A
SWRLY LLJ AT ARND 850 MB WHICH WILL LEAD TO A SHOT OF WAA AND
MOISTURE ADVTN INTO NY AND NRN PA. THIS WAA WILL LEAD TO A BATCH
OF LIGHT RAIN SPREADING ACRS MOST OF THE CWA BETWEEN 6Z AND
12Z FRI...WITH SOME LIGHTER PRECIP POTENTIALLY ARRIVING A TAD
EARLIER IN WRN NY. MODEL SOUNDING DATA SUGGESTS ALL RAIN
SPREADING EWRD AS THERE WILL BE NON-DIURNAL TEMP TRENDS WITH THE
MIN/S OCCURRING IN THU EVENING AND RISING TEMPS OVERNIGHT INTO FRI
AM WHEN THE BULK OF THE PRECIP ARRIVES.
AFTER THIS FIRST SHOT OF WAA RAIN SHRA PASSES...THERE WILL BE A
LULL IN THE RAINFALL FRI AM IN ADVANCE OF THE CD FRNT WHICH
REACHES WRN NY BY 18Z AND THEN CROSSES THE REST OF C NY/NE PA BY
FRI EVE. THERE WILL BE SHRA WITH THIS FRONT AND A LITTLE BEHIND
IT. THEN THERE WILL BE ANOTHER LULL IN THE PRECIP UNTIL THE NEXT
WAVE APPROACHES SAT PM WHICH WILL BE ASSCTD WITH A SFC LO AND THE
TRUE ARCTIC FRNT WHICH REACHES INTO THE ERN LAKES SAT PM. FOR
SAT...IT LOOKS LIKE BY AFTERNOON MOST OF THE CWA WILL SEE SN SHWRS
AND FLURRIES AS 850 MB TEMPS DROP TO -10C OR BLO. AGAIN THERE WILL
BE A NON-DIURNAL TEMP TREND SAT PM WITH STRG CAA. MAXES SHUD OCCUR
LATE MORNING SAT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
230 AM UPDATE...
SEE NO REASON TO MAKE TOO MANY CHGS TO EXTNDD FCST. COLD TEMPS
EXPECTED FOR SUNDAY AS THICKNESS VALUES DROP BLO 500DM FOR A TIME
DRG THE AFTN. H8 TEMPS EXPECTED TO RANGE BTWN -15C AND -20C,
YIELDING HIGHS IN THE 20S. THIS WL BE SOME 20F DEGREES BLO NORMAL
FOR THE DAY. AN UPR LOW WL BEGIN TO EJECT OUT OF THE PLAINS ON
TUESDAY WITH MED RANGE MODELS INDICATING A SFC LOW WL DVLP ACRS
THE NRN GOM BY 12Z TUESDAY. HWVR, WHERE IT GOES FM THERE IS UP IN
THE AIR AT THIS POINT, WITH 00Z EC BRINGING IT INTO MID-ATLANTIC
STATES BY MID-WEEK AND GFS KEEPING IT CONFINED TO SE COAST. HV
GONE WITH A VAGUE 30 POPS FOR TUE/WED DUE TO SIGNIFICANT AMNT OF
UNCERTAINTY.
PREVIOUS DISCUSSION...
EXTENDED FORECAST BEGINS WITH A VERY COLD AIRMASS ACROSS THE
NORTHEAST AS A DEEP UPPER LEVEL TROF SWINGS THROUGH THE AREA. BOTH
THE GFS/ECMWF CONTINUE TO ADVERTISE T85 AROUND -16C/-18C FOR 18Z
SUN. THEY BOTH HAVE BEEN CONSISTENT WITH THIS COLD AIRMASS FOR
SEVERAL RUNS NOW INDICATING A HIGH LIKELY HOOD OF OCCURRENCE.
INITIALLY THE LOW LEVEL FLOW SATURDAY NIGHT LOOKS AROUND 290
DEGREES THEN SHIFTS MORE NORTHWEST AFTER 06Z AS A SECONDARY TROF
PASSES. ON SUNDAY, THE LOW LEVEL FLOW WILL BACK AS H85 RIDGE MOVES
THROUGH THE AREA. FOR SATURDAY NIGHT THROUGH SUNDAY WILL CONTINUE
TO ADVERTISE LIKELY POPS FOR LES PRIMARILY SOUTHEAST OF LAKE
ONTARIO. SNOW ACCUMS THROUGH THE PERIOD WILL LIKELY REACH SEVERAL
INCHES WITH A LAKE SNOW ADVISORY MOST LIKELY NEEDED SATURDAY NIGHT
INTO SUNDAY AS THE EVENT APPROACHES. A SHORT FETCH AND LIMITED
SYNOPTIC MOISTURE MAY LIMIT ACCUMS BUT THE AIRMASS IS VERY COLD
FOR THIS TIME OF THE YEAR.
MONDAY NIGHT INTO WEDNESDAY, A NORTHERN STREAM SYSTEM WILL MOVE
THROUGH THE UPPER GREAT LAKES AND ACROSS EASTERN CANADA. WILL
MENTION CHC/SLIGHT CHC POPS FOR SNOW SHOWERS. THE MEDIUM RANGE
MODELS HAVE HINTED AT A NORTHERN/SOUTHERN STREAM PHASING TUE INTO
WED WITH THE DEVELOPMENT OF A STRONG COAST LOW WHICH COULD IMPACT
THE FORECAST AREA. THE LATEST OPERATIONAL RUNS OF THE GFS/ECMWF
NOW SHOW THE SYSTEM REMAINING PRIMARILY EAST/SOUTH OF THE AREA.
IT`S STILL EARLY, SOMETHING TO WATCH.
TEMPS THROUGH THE PERIOD WILL BE AROUND 10-15 DEGREES BELOW
NORMAL.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
HIGH PRESSURE WILL KEEP TERMINALS VFR FOR THE NEXT 24 HOURS. SCT-
BKN 25KFT CIGS EXPECTED THROUGH 13Z-17Z BEFORE MID-DECK BEGINS TO MOVE
IN. AFTER 21Z ACROSS WESTERN TERMINALS OVC050 EXPECTED BY 21Z AND
SLOWLY PROGRESSING EAST FROM THERE. OVERALL NO RESTRICTIONS
EXPECTED THROUGH 06Z FRIDAY THOUGH A STRAY SHOWER WILL BE POSSIBLE
TOWARD THE END OF TAF VALID TIME.
EAST TO SOUTHEAST WINDS AROUND 5 KTS OVERNIGHT BECOMING SOUTH
AROUND 8 KTS STARTING 15Z.
OUTLOOK...
LATE THURSDAY NIGHT INTO FRIDAY...MVFR AND POSSIBLY IFR
RESTRICTIONS LIKELY FROM RAIN SHOWERS.
FRI NIGHT INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD
FRONT PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT
SHSN...ESPECIALLY CENTRAL NY TERMINALS.
SUNDAY NIGHT AND MONDAY MORNING...VFR.
MONDAY AFTN...RESTRICTIONS POSSIBLE IN SNOW SHOWERS PRIMARILY NYS
TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/DJN/TAC
NEAR TERM...CMG/DJN/MLJ
SHORT TERM...DJN
LONG TERM...PVN/RRM
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1231 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHEAST UNITED STATES WILL MOVE OFF THE
COAST TONIGHT AND LEAD TO A SOUTHERLY FLOW OF MILDER AIR FOR
THURSDAY. A WARM FRONT WITH RAIN SHOWERS WILL MOVE THROUGH THE
REGION THURSDAY NIGHT AND FRIDAY. A STRONG COLD FRONT WILL MOVE
THROUGH THE REGION FRIDAY NIGHT, WHICH WILL USHER IN MUCH COLDER
AIR STARTING SUNDAY. THIS COLD AIR COULD GENERATE SIGNIFICANT
LAKE EFFECT SNOWS IN THE LAKE EFFECT SNOW BELTS OF NORTH CENTRAL
NEW YORK.
&&
.NEAR TERM /THROUGH TODAY/...
745 PM UPDATE... ONLY MINOR TWEAKS WERE MADE TO THE GRIDS EARLY
THIS EVE...WITH OUR EXISTING FCST IN GOOD SHAPE.
SAT IMAGERY/SFC OBS ARE SHOWING THIN HIGH CLDNS CROSSING CNY/NE PA
THIS EVE. GIVEN SAT TRENDS UPSTREAM...WE THINK WE`LL CONTINUE TO
SEE SOME HIGH CLOUD COVER OVERNIGHT...BUT GIVEN ITS FAIRLY
TRANSPARENT NATURE...PTLY CLDY SEEMS LIKE A GOOD SKY COVER
DESCRIPTOR. THERE WAS SOME THINKING EARLIER TDY THAT A MARINE LYR
CLOUD DECK COULD SNEAK UP INTO OUR SERN ZNS BY...OR JUST AFTER
09Z THU. ALTHOUGH THERE IS SOME PATCHY SC ATTM ACRS SRN VA...WE
THINK THAT LWR CLDS WILL NOT MAKE IT TO NE PA BY DAYBREAK FOR SVRL
REASONS...LACK OF CLOUD DVLPMT/ONSHORE FLOW ATTM OVER MOST OF THE
DELMARVA RGN OR NJ...WEAK LOW-LVL FLOW...AND A VERY DRY RESIDENT
AMS IN THE BLYR (SFC DEW PTS NEAR 10F OVER MUCH OF ERN PA ATTM).
WE STILL FEEL CONFIDENT SOME OF OUR NORMALLY COLDER SHELTERED VLYS
WILL DROP INTO THE TEENS BY DAYBREAK. AS A RESULT...WE BASICALLY
LEFT OUR LOW TEMP FCST ALONE...AND JUST MASSAGED SOME NEAR-TERM
TEMPS AND DEW PTS THIS EVE.
PREV DISC... HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S INTO
THIS EVENING AS THE UPPER LEVEL RDG AXIS SLOWLY MOVES E. EXPECT
ONLY SOME PATCHY CIRRUS AT TIMES WORKG OVER THE UPR LVL RDG AXIS
WHICH WILL BE MOVG OVHD THIS EVE. OTHERWISE FAIR WX THIS EVENING.
FOR OVERNIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12..12Z CMC AND RUC13 AS WELL AS THE LATEST 12Z GFS
ALL SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE
MIDDLE ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING
NORTHWARD REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS
LAYER FARTHER S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS
REACHING NRN PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM/GFS
AND CMC.
ON THURSDAY THERE WILL BE A SOUTHERLY RETURN FLOW SETTING UP AS
THE SFC HIGH IS OFFSHORE. THE 925 MB TO 850 MB WINDS WILL BE FROM
THE SOUTH AND BASED ON THE LATEST NAM...GFS AND CMC MODELS LL
MOISTURE WILL BE ON THE INCREASE THURSDAY AS CIRRUS AND MID CLDS
POUR IN FROM THE WEST AS HI LEVEL THERMAL ADVECTIONS BEGIN IN
ADVANCE OF THE NEXT SYSTEM. THEREFORE WILL HAVE INCREASING AMNTS
OF CLDS DURING THE DAY THURSDAY. LOOKS LIKE ANY PRECIP WILL HOLD
OFF B4 00Z FRI.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
FOR THURSDAY NIGHT...AN UPPER LEVEL JET STREAK WITH THE NEXT
SYSTEM WILL PUSH INTO THE LOWER LAKES/UPR OH VLLY AND SUPPORT A
SWRLY LLJ AT ARND 850 MB WHICH WILL LEAD TO A SHOT OF WAA AND
MOISTURE ADVTN INTO NY AND NRN PA. THIS WAA WILL LEAD TO A BATCH
OF LIGHT RAIN SPREADING ACRS MOST OF THE CWA BETWEEN 6Z AND
12Z FRI...WITH SOME LIGHTER PRECIP POTENTIALLY ARRIVING A TAD
EARLIER IN WRN NY. MODEL SOUNDING DATA SUGGESTS ALL RAIN
SPREADING EWRD AS THERE WILL BE NON-DIURNAL TEMP TRENDS WITH THE
MIN/S OCCURRING IN THU EVENING AND RISING TEMPS OVERNIGHT INTO FRI
AM WHEN THE BULK OF THE PRECIP ARRIVES.
AFTER THIS FIRST SHOT OF WAA RAIN SHRA PASSES...THERE WILL BE A
LULL IN THE RAINFALL FRI AM IN ADVANCE OF THE CD FRNT WHICH
REACHES WRN NY BY 18Z AND THEN CROSSES THE REST OF C NY/NE PA BY
FRI EVE. THERE WILL BE SHRA WITH THIS FRONT AND A LITTLE BEHIND
IT. THEN THERE WILL BE ANOTHER LULL IN THE PRECIP UNTIL THE NEXT
WAVE APPROACHES SAT PM WHICH WILL BE ASSCTD WITH A SFC LO AND THE
TRUE ARCTIC FRNT WHICH REACHES INTO THE ERN LAKES SAT PM. FOR
SAT...IT LOOKS LIKE BY AFTERNOON MOST OF THE CWA WILL SEE SN SHWRS
AND FLURRIES AS 850 MB TEMPS DROP TO -10C OR BLO. AGAIN THERE WILL
BE A NON-DIURNAL TEMP TREND SAT PM WITH STRG CAA. MAXES SHUD OCCUR
LATE MORNING SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EXTENDED FORECAST BEGINS WITH A VERY COLD AIRMASS ACROSS THE
NORTHEAST AS A DEEP UPPER LEVEL TROF SWINGS THROUGH THE AREA. BOTH
THE GFS/ECMWF CONTINUE TO ADVERTISE T85 AROUND -16C/-18C FOR 18Z
SUN. THEY BOTH HAVE BEEN CONSISTENT WITH THIS COLD AIRMASS FOR
SEVERAL RUNS NOW INDICATING A HIGH LIKELY HOOD OF OCCURRENCE.
INITIALLY THE LOW LEVEL FLOW SATURDAY NIGHT LOOKS AROUND 290
DEGREES THEN SHIFTS MORE NORTHWEST AFTER 06Z AS A SECONDARY TROF
PASSES. ON SUNDAY, THE LOW LEVEL FLOW WILL BACK AS H85 RIDGE MOVES
THROUGH THE AREA. FOR SATURDAY NIGHT THROUGH SUNDAY WILL CONTINUE
TO ADVERTISE LIKELY POPS FOR LES PRIMARILY SOUTHEAST OF LAKE
ONTARIO. SNOW ACCUMS THROUGH THE PERIOD WILL LIKELY REACH SEVERAL
INCHES WITH A LAKE SNOW ADVISORY MOST LIKELY NEEDED SATURDAY NIGHT
INTO SUNDAY AS THE EVENT APPROACHES. A SHORT FETCH AND LIMITED
SYNOPTIC MOISTURE MAY LIMIT ACCUMS BUT THE AIRMASS IS VERY COLD
FOR THIS TIME OF THE YEAR.
MONDAY NIGHT INTO WEDNESDAY, A NORTHERN STREAM SYSTEM WILL MOVE
THROUGH THE UPPER GREAT LAKES AND ACROSS EASTERN CANADA. WILL
MENTION CHC/SLIGHT CHC POPS FOR SNOW SHOWERS. THE MEDIUM RANGE
MODELS HAVE HINTED AT A NORTHERN/SOUTHERN STREAM PHASING TUE INTO
WED WITH THE DEVELOPMENT OF A STRONG COAST LOW WHICH COULD IMPACT
THE FORECAST AREA. THE LATEST OPERATIONAL RUNS OF THE GFS/ECMWF
NOW SHOW THE SYSTEM REMAINING PRIMARILY EAST/SOUTH OF THE AREA.
IT`S STILL EARLY, SOMETHING TO WATCH.
TEMPS THROUGH THE PERIOD WILL BE AROUND 10-15 DEGREES BELOW
NORMAL.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
HIGH PRESSURE WILL KEEP TERMINALS VFR FOR THE NEXT 24 HOURS. SCT-
BKN 25KFT CIGS EXPECTED THROUGH 13Z-17Z BEFORE MID-DECK BEGINS TO MOVE
IN. AFTER 21Z ACROSS WESTERN TERMINALS OVC050 EXPECTED BY 21Z AND
SLOWLY PROGRESSING EAST FROM THERE. OVERALL NO RESTRICTIONS
EXPECTED THROUGH 06Z FRIDAY THOUGH A STRAY SHOWER WILL BE POSSIBLE
TOWARD THE END OF TAF VALID TIME.
EAST TO SOUTHEAST WINDS AROUND 5 KTS OVERNIGHT BECOMING SOUTH
AROUND 8 KTS STARTING 15Z.
OUTLOOK...
LATE THURSDAY NIGHT INTO FRIDAY...MVFR AND POSSIBLY IFR
RESTRICTIONS LIKELY FROM RAIN SHOWERS.
FRI NIGHT INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD
FRONT PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT
SHSN...ESPECIALLY CENTRAL NY TERMINALS.
SUNDAY NIGHT AND MONDAY MORNING...VFR.
MONDAY AFTN...RESTRICTIONS POSSIBLE IN SNOW SHOWERS PRIMARILY NYS
TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/TAC
NEAR TERM...DJN/MLJ
SHORT TERM...DJN
LONG TERM...RRM
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1225 PM EST THU NOV 21 2013
.SYNOPSIS...
A COASTAL TROUGH WILL BRING PERIODS OF ATLANTIC CLOUD COVER ONSHORE
THROUGH FRIDAY. A COLD FRONT WILL CROSS THE AREA LATE SATURDAY
FOLLOWED BY A BRIEF PERIOD OF VERY COLD AIR. A SIGNIFICANT RAIN
EVENT IS BECOMING MORE LIKELY TOWARD THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...EAST TO NORTHEAST LOW-LEVEL FLOW WILL
PROVIDE SOME ATLANTIC MOISTURE WHILE WESTERLY WINDS ALOFT SPREAD A
VARIETY OF MID AND HIGH CLOUDS INTO THE REGION. REGARDLESS...ENOUGH
BREAKS IN THE CLOUDS THIS MORNING TO ALLOW FOR A RAPID WARM-UP...
ESPECIALLY ACROSS COASTAL SOUTHEAST NC WHERE TEMPS ARE ALREADY IN
THE MID TO UPPER 50S. COOLER TEMPERATURES (LOWER 50S) PREVAIL ACROSS
REMAINING AREAS...AND THE MODELS CONTINUE TO VARY SIGNIFICANTLY WITH
MAX TEMPS THIS AFTERNOON. PLAN TO LOWER TEMPS WHERE THE CLOUD
COVER IS EXPECTED TO HAVE THE MOST IMPACT WHILE NUDGING THEM UPWARDS
WHERE THE BIGGEST BREAKS ARE ANTICIPATED. OVERALL...A TRICKY TEMP
FORECAST TODAY GIVEN THE RESIDUAL WEDGE...VARYING CLOUD COVER... AND
LOWER MID-LATE NOVEMBER SUN ANGLE. WIDELY SCATTERED SHOWER ACTIVITY
ASSOCIATED WITH THE WEAK TROUGH WILL PRIMARILY REMAIN OVER THE WATER
THROUGH MUCH OF THE DAY...THOUGH A COUPLE OF THEM MAY MAKE IT TO THE
COAST LATER IN THE DAY.
PREVIOUS DISCUSSION...
DRY RIDGING AT 700 AND 500 MILLIBARS USUALLY IMPLIES BENIGN WEATHER
DOWN HERE AT THE SURFACE. NOT SO THIS TIME AS A TIGHT PRESSURE
GRADIENT AROUND THE SOUTHERN PERIPHERY OF 1038 MB HIGH PRESSURE OVER
NEW ENGLAND...PLUS A WEAK COASTAL TROUGH OUT NEAR THE GULF STREAM
ARE ADVECTING ATLANTIC MOISTURE ONSHORE. THIS MOISTURE EXTENDS
VERTICALLY TO AROUND 8000 FEET AT WHICH POINT A SIGNIFICANT LAYER OF
DRY AIR EXISTS WITHIN THE WESTERLY FLOW ALOFT.
AS WAS TRUE ON THE 00Z MODEL RUNS...THERE ARE STILL UNANSWERED BASIC
QUESTIONS CONCERNING TODAY`S FORECAST USING THE 06Z RUNS. THE AMOUNT
OF LOW CLOUD COVER THAT REMAINS INTO THE AFTERNOON WILL LARGELY
DETERMINE OUR TEMPERATURES. ANY ISENTROPIC LIFT IS SITUATED VERY LOW
IN THE ATMOSPHERE AND BECOMES QUITE WEAK BY AFTERNOON. THERE IS
NEARLY A TEN-DEGREE DIFFERENCE BETWEEN THE 00Z NAM AND GFS INLAND...
AND NO CLEAR SIGNAL WHICH MODEL...IF EITHER...IS RIGHT. THE WEDGE
PATTERN TO THE PRESSURE AND WIND FIELDS ACROSS THE CAROLINAS IMPLIES
THE COOLER GFS MAY BE THE WAY TO GO...ALTHOUGH I WOULD FEEL MORE
CONFIDENT IN THIS DECISION IF THERE WERE RAIN AND/OR WIDESPREAD LOW
STRATUS ACROSS CENTRAL NORTH CAROLINA TO HELP OFFSET INSOLATION. THE
06Z RUNS ESSENTIALLY MIRRORED THEIR 00Z COUNTERPARTS...BUT THE
LATEST RUC AND HRRR HAVE COME FIRMLY INTO LINE WITH THE WARMER 00Z
AND 06Z NAM.
THE AIRMASS IS MODIFYING QUICKLY OVERHEAD WITH WARM ADVECTION IN THE
800-950 MB LAYER ADDING A GOOD 2-3 DEGREES C THROUGH THIS EVENING.
ALONG THIS COAST THIS SHOULD YIELD HIGHS IN THE UPPER 60S...PERHAPS
EVEN SQUEAKING OUT A 70 DEGREE READING HERE AND THERE AWAY FROM THE
BEACHES. FARTHER INLAND IS WHERE LARGER QUESTIONS REMAIN. WITH LOW
CONFIDENCE I AM FORECASTING HIGHS IN THE 62-64 RANGE ALONG THE I-95
CORRIDOR...60-61 FOR BENNETTSVILLE AND DARLINGTON...AND 64-67 FROM
ELIZABETHTOWN AND WHITEVILLE THROUGH MARION...LAKE CITY AND
KINGSTREE.
ALTHOUGH RADAR SHOWS A BAND OF SHOWERS ALONG THE WESTERN EDGE OF THE
GULF STREAM...PROBABILITIES OF MEASURABLE RAIN ARE LOW TODAY GIVEN
POOR ISENTROPIC LIFT SHOWN ON ANY MODEL. LINEAR EXTRAPOLATION OF THE
SHOWERS SHOULD HAVE ALREADY PUSHED THEM ONSHORE HOURS AGO...
INDICATING LOCAL ENVIRONMENTAL CONDITIONS OUT AT THE EDGE OF THE
GULF STREAM ARE PROBABLY KEY TO SUSTAINING THIS ACTIVITY. I AM
INCLUDING A 20 POP NEAR THE COAST LATER TODAY JUST IN CASE SOMETHING
SNEAKS IN OFF THE WATER DURING THE BEST WARM ADVECTION AROUND NOON.
WIND FIELDS SHOULD WEAKEN TONIGHT AS THE HIGH OVER NEW ENGLAND
RAPIDLY WEAKENS AND SHIFTS OFFSHORE. PLENTY OF LOW LEVEL ATLANTIC
MOISTURE WILL MODERATE TEMPERATURES...AND LOWS SHOULD RANGE FROM
AROUND 50 IN LUMBERTON TO THE MID 50S AT THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE FORECAST CHALLENGE CONTINUES TO THE BE
THE WEAK FORCING AND MOISTURE ASSOCIATED WITH A COASTAL TROUGH
FRIDAY THEN THE MOISTURE WITH A LONG ADVERTISED FRONT MOVING ACROSS
LATE SATURDAY/EARLY SUNDAY. THE GUIDANCE HAS WALKED BACK MOISTURE
WITH THE COASTAL TROUGH FRIDAY AND WITH THE ERRATIC NATURE OF THESE
TYPE OF FEATURES AND VOLATILITY OF GUIDANCE...THE BEST OPTION IS TO
KEEP POPS AS THEY ARE. FOR SATURDAY I HAVE FINE TUNED POPS TO
EMPHASIZE THE AFTERNOON AND EVENING HOURS PER THE LATEST MODEL
GUIDANCE. AS FOR TEMPERATURES...THE MET NUMBERS ARE WARMER ACROSS
THE BOARD AND GENERALLY LEANED TOWARD THESE NUMBERS THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...THE EXTENDED FORECAST LOOKS TO BE VERY
ACTIVE WITH THE EMPHASIS NOW SHIFTING TO THE END OF THE PERIOD WHEN
A CUTOFF LOW OUT WEST OPENS UP AND MOVES ACROSS THE SOUTHEAST.
SUNDAY AND MONDAY ARE FAIRLY CLEAR CUT AS COLD AIR ADVECTION
DOMINATES WITH TEMPERATURES MOST LIKELY NOT GETTING OUT OF THE 40S
SUNDAY AND DEPENDING ON DECOUPLING...MONDAY MORNINGS LOWS WELL INTO
THE 20S. FOR TUESDAY AND WEDNESDAY...THE LOW TAKES SHAPE IN THE GULF
OF MEXICO WITH A RELATIVELY WEAK AND FLEETING COLD AIR WEDGE HANGING
ON. ISENTROPIC LIFT DEVELOPS IN EARNEST LATE TUESDAY. THE LOW
ATTEMPTS TO REDEVELOP ALONG THE COASTAL FRONT WEDNESDAY BUT AT LEAST
AT THIS POINT DOESN/T BECOME DOMINANT. TOUGH CALL ON MILLER A OR B
SCENARIO HOWEVER THIS FAR OUT THIS IS HAGGLING OVER DETAILS AND RAIN
WILL CONTINUE WEDNESDAY AS THE MID LEVEL SYSTEM MOVES ACROSS. WE
HAVE FAIRLY HIGH POPS FOR TUESDAY AND ESPECIALLY WEDNESDAY ALREADY
SO I ONLY INCREMENTALLY INCREASED POPS. NO CHANGES TO TEMPERATURE
FORECAST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...CURRENT VISIBLE SATELLITE IMAGERY SHOWS PATCHES OF
ALTOCUMULUS 8-10KFT MAINLY OVER KFLO AND OUR INLAND COUNTIES. THERE
ARE ALSO SOME SCT 2-3KFT CLOUDS LINGERING ALONG THE COAST. VFR
SHOULD PREVAIL THIS AFTN WITH NORTHEAST WINDS AOB 10 KTS...THOUGH WE
COULD SEE SOME TEMPO MVFR CIGS ALONG THE COAST. LIGHT WINDS TONIGHT
WITHIN A VERY MOIST LOW LEVEL ENVIRONMENT SHOULD SUPPORT FOG AFTER
06Z FRIDAY. HOWEVER...MODEL SOUNDINGS AND GUIDANCE SUGGEST MID LEVEL
CIGS WILL PREVAIL TONIGHT...WHICH WOULD PREVENT OPTIMAL RADIATIONAL
COOLING. THEREFORE...WILL ONLY INCLUDE MVFR FOG FOR ALL SITES...
BEGINNING WITH KLBT AND KFLO BY 06Z. THESE INLAND SITES HAVE THE
BEST CHANCES FOR FOG...BUT WIDESPREAD IFR SEEMS UNLIKELY WITH THE
EXPECTED CLOUD COVER. EXPECT VFR DURING THE DAY ON FRIDAY WITH S-SE
WINDS AROUND 5 KTS.
EXTENDED OUTLOOK...CHANCE OF SHOWERS/MVFR CIGS ON SATURDAY WITH A
COLD FRONT. VFR SUNDAY AND MONDAY. EXPECT GUSTY NORTH WINDS ON
SUNDAY BEHIND THE FRONT. INCREASING CHANCE FOR SHOWERS ON TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...BASED ON THE MARINE OBSERVATIONS IT IS
IMPLIED THAT SMALL CRAFT CONDITIONS LIKELY CONTINUE ACROSS THE OUTER
COASTAL WATERS...EXCEPT FROM MURRELLS INLET TO LITTLE RIVER INLET.
CONDITIONS WILL SLOWLY IMPROVE AS THE WEAKENING COASTAL TROUGH
SHIFTS FARTHER WEST. MAY NEED TO REFINE THE ENDING TIME OF THE
REMAINING SMALL CRAFT AREAS BASED ON TRENDS HEADING INTO THIS
AFTERNOON...BUT UNTIL THEN CHOPPY SEAS WILL CONTINUE WITH THE
NORTHEAST TO EAST FETCH THAT HAS BEEN IN PLACE. WIDELY SCATTERED
SHOWERS WILL PRIMARILY AFFECT THE OUTER COASTAL WATERS THROUGH MOST
OF THE DAY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...THE PROLONGED NORTHEAST FLOW WILL BE ABATING
AT THE BEGINNING OF THE PERIOD AS SURFACE HIGH PRESSURE WEAKENS AND
ELONGATES WEST TO EAST. A WEAK SOUTH TO SOUTHWEST TO EVENTUALLY
WESTERLY FLOW WILL THEN TAKE PLACE. SPEEDS WILL REMAIN TEPID AROUND
TEN KNOTS. SATURDAY EVENING THE FRONT WILL CROSS THE WATERS AND BY
0600 UTC SUNDAY ELEMENTS WILL BE VERY DIFFERENT FROM JUST A FEW
HOURS EARLIER AS NORTH WINDS OF 25-30 KNOTS DEVELOP. A BRIEF GALE
WARNING CANNOT BE RULED OUT. SEAS OF COURSE WILL BE BENIGN FOR MOST
OF THE PERIOD BUT RAMPING UP QUICKLY ESPECIALLY ACROSS THE OUTER
WATERS LATE WITH THE RAPID INCREASE IN WIND SPEEDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...POTENT COLD AIR ADVECTION WILL DOMINATE THE
COASTAL WATERS SUNDAY WITH NORTH WINDS OF 20-25 KNOTS. WITH THE
PROGRESSIVE PATTERN...THE SURFACE HIGH WILL QUICKLY MOVE ACROSS THE
WATERS MONDAY WITH NORTHEAST WINDS DOWN TO 10-15 KNOTS AND EVEN LESS
BY THE END OF THE DAY. SEAS WILL BE HIGH SUNDAY BUT CONFINED TO THE
OUTER WATERS CONSIDERING THE FETCH WITH A SMALL CRAFT ADVISORY
LIKELY CONTINUING. MONDAY SEAS DROP TO 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ250-252-
256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
921 AM EST THU NOV 21 2013
.SYNOPSIS...
A COASTAL TROUGH WILL BRING PERIODS OF ATLANTIC CLOUD COVER ONSHORE
THROUGH FRIDAY. A COLD FRONT WILL CROSS THE AREA LATE SATURDAY
FOLLOWED BY A BRIEF PERIOD OF VERY COLD AIR. A SIGNIFICANT RAIN
EVENT IS BECOMING MORE LIKELY TOWARD THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...EAST TO NORTHEAST LOW-LEVEL FLOW WILL
PROVIDE SOME ATLANTIC MOISTURE WHILE WESTERLY WINDS ALOFT SPREAD A
VARIETY OF MID AND HIGH CLOUDS INTO THE REGION. REGARDLESS...ENOUGH
BREAKS IN THE CLOUDS THIS MORNING TO ALLOW FOR A RAPID WARM-UP...
ESPECIALLY ACROSS COASTAL SOUTHEAST NC WHERE TEMPS ARE ALREADY IN
THE MID TO UPPER 50S. COOLER TEMPERATURES (LOWER 50S) PREVAIL ACROSS
REMAINING AREAS...AND THE MODELS CONTINUE TO VARY SIGNIFICANTLY WITH
MAX TEMPS THIS AFTERNOON. PLAN TO LOWER TEMPS WHERE THE CLOUD
COVER IS EXPECTED TO HAVE THE MOST IMPACT WHILE NUDGING THEM UPWARDS
WHERE THE BIGGEST BREAKS ARE ANTICIPATED. OVERALL...A TRICKY TEMP
FORECAST TODAY GIVEN THE RESIDUAL WEDGE...VARYING CLOUD COVER... AND
LOWER MID-LATE NOVEMBER SUN ANGLE. WIDELY SCATTERED SHOWER ACTIVITY
ASSOCIATED WITH THE WEAK TROUGH WILL PRIMARILY REMAIN OVER THE WATER
THROUGH MUCH OF THE DAY...THOUGH A COUPLE OF THEM MAY MAKE IT TO THE
COAST LATER IN THE DAY.
PREVIOUS DISCUSSION...
DRY RIDGING AT 700 AND 500 MILLIBARS USUALLY IMPLIES BENIGN WEATHER
DOWN HERE AT THE SURFACE. NOT SO THIS TIME AS A TIGHT PRESSURE
GRADIENT AROUND THE SOUTHERN PERIPHERY OF 1038 MB HIGH PRESSURE OVER
NEW ENGLAND...PLUS A WEAK COASTAL TROUGH OUT NEAR THE GULF STREAM
ARE ADVECTING ATLANTIC MOISTURE ONSHORE. THIS MOISTURE EXTENDS
VERTICALLY TO AROUND 8000 FEET AT WHICH POINT A SIGNIFICANT LAYER OF
DRY AIR EXISTS WITHIN THE WESTERLY FLOW ALOFT.
AS WAS TRUE ON THE 00Z MODEL RUNS...THERE ARE STILL UNANSWERED BASIC
QUESTIONS CONCERNING TODAY`S FORECAST USING THE 06Z RUNS. THE AMOUNT
OF LOW CLOUD COVER THAT REMAINS INTO THE AFTERNOON WILL LARGELY
DETERMINE OUR TEMPERATURES. ANY ISENTROPIC LIFT IS SITUATED VERY LOW
IN THE ATMOSPHERE AND BECOMES QUITE WEAK BY AFTERNOON. THERE IS
NEARLY A TEN-DEGREE DIFFERENCE BETWEEN THE 00Z NAM AND GFS INLAND...
AND NO CLEAR SIGNAL WHICH MODEL...IF EITHER...IS RIGHT. THE WEDGE
PATTERN TO THE PRESSURE AND WIND FIELDS ACROSS THE CAROLINAS IMPLIES
THE COOLER GFS MAY BE THE WAY TO GO...ALTHOUGH I WOULD FEEL MORE
CONFIDENT IN THIS DECISION IF THERE WERE RAIN AND/OR WIDESPREAD LOW
STRATUS ACROSS CENTRAL NORTH CAROLINA TO HELP OFFSET INSOLATION. THE
06Z RUNS ESSENTIALLY MIRRORED THEIR 00Z COUNTERPARTS...BUT THE
LATEST RUC AND HRRR HAVE COME FIRMLY INTO LINE WITH THE WARMER 00Z
AND 06Z NAM.
THE AIRMASS IS MODIFYING QUICKLY OVERHEAD WITH WARM ADVECTION IN THE
800-950 MB LAYER ADDING A GOOD 2-3 DEGREES C THROUGH THIS EVENING.
ALONG THIS COAST THIS SHOULD YIELD HIGHS IN THE UPPER 60S...PERHAPS
EVEN SQUEAKING OUT A 70 DEGREE READING HERE AND THERE AWAY FROM THE
BEACHES. FARTHER INLAND IS WHERE LARGER QUESTIONS REMAIN. WITH LOW
CONFIDENCE I AM FORECASTING HIGHS IN THE 62-64 RANGE ALONG THE I-95
CORRIDOR...60-61 FOR BENNETTSVILLE AND DARLINGTON...AND 64-67 FROM
ELIZABETHTOWN AND WHITEVILLE THROUGH MARION...LAKE CITY AND
KINGSTREE.
ALTHOUGH RADAR SHOWS A BAND OF SHOWERS ALONG THE WESTERN EDGE OF THE
GULF STREAM...PROBABILITIES OF MEASURABLE RAIN ARE LOW TODAY GIVEN
POOR ISENTROPIC LIFT SHOWN ON ANY MODEL. LINEAR EXTRAPOLATION OF THE
SHOWERS SHOULD HAVE ALREADY PUSHED THEM ONSHORE HOURS AGO...
INDICATING LOCAL ENVIRONMENTAL CONDITIONS OUT AT THE EDGE OF THE
GULF STREAM ARE PROBABLY KEY TO SUSTAINING THIS ACTIVITY. I AM
INCLUDING A 20 POP NEAR THE COAST LATER TODAY JUST IN CASE SOMETHING
SNEAKS IN OFF THE WATER DURING THE BEST WARM ADVECTION AROUND NOON.
WIND FIELDS SHOULD WEAKEN TONIGHT AS THE HIGH OVER NEW ENGLAND
RAPIDLY WEAKENS AND SHIFTS OFFSHORE. PLENTY OF LOW LEVEL ATLANTIC
MOISTURE WILL MODERATE TEMPERATURES...AND LOWS SHOULD RANGE FROM
AROUND 50 IN LUMBERTON TO THE MID 50S AT THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE FORECAST CHALLENGE CONTINUES TO THE BE
THE WEAK FORCING AND MOISTURE ASSOCIATED WITH A COASTAL TROUGH
FRIDAY THEN THE MOISTURE WITH A LONG ADVERTISED FRONT MOVING ACROSS
LATE SATURDAY/EARLY SUNDAY. THE GUIDANCE HAS WALKED BACK MOISTURE
WITH THE COASTAL TROUGH FRIDAY AND WITH THE ERRATIC NATURE OF THESE
TYPE OF FEATURES AND VOLATILITY OF GUIDANCE...THE BEST OPTION IS TO
KEEP POPS AS THEY ARE. FOR SATURDAY I HAVE FINE TUNED POPS TO
EMPHASIZE THE AFTERNOON AND EVENING HOURS PER THE LATEST MODEL
GUIDANCE. AS FOR TEMPERATURES...THE MET NUMBERS ARE WARMER ACROSS
THE BOARD AND GENERALLY LEANED TOWARD THESE NUMBERS THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...THE EXTENDED FORECAST LOOKS TO BE VERY
ACTIVE WITH THE EMPHASIS NOW SHIFTING TO THE END OF THE PERIOD WHEN
A CUTOFF LOW OUT WEST OPENS UP AND MOVES ACROSS THE SOUTHEAST.
SUNDAY AND MONDAY ARE FAIRLY CLEAR CUT AS COLD AIR ADVECTION
DOMINATES WITH TEMPERATURES MOST LIKELY NOT GETTING OUT OF THE 40S
SUNDAY AND DEPENDING ON DECOUPLING...MONDAY MORNINGS LOWS WELL INTO
THE 20S. FOR TUESDAY AND WEDNESDAY...THE LOW TAKES SHAPE IN THE GULF
OF MEXICO WITH A RELATIVELY WEAK AND FLEETING COLD AIR WEDGE HANGING
ON. ISENTROPIC LIFT DEVELOPS IN EARNEST LATE TUESDAY. THE LOW
ATTEMPTS TO REDEVELOP ALONG THE COASTAL FRONT WEDNESDAY BUT AT LEAST
AT THIS POINT DOESN/T BECOME DOMINANT. TOUGH CALL ON MILLER A OR B
SCENARIO HOWEVER THIS FAR OUT THIS IS HAGGLING OVER DETAILS AND RAIN
WILL CONTINUE WEDNESDAY AS THE MID LEVEL SYSTEM MOVES ACROSS. WE
HAVE FAIRLY HIGH POPS FOR TUESDAY AND ESPECIALLY WEDNESDAY ALREADY
SO I ONLY INCREMENTALLY INCREASED POPS. NO CHANGES TO TEMPERATURE
FORECAST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SURFACE ANALYSIS THIS MORNING SHOWS HIGH PRESSURE
WEDGING DOWN FROM NEW ENGLAND AND A COASTAL TROUGH OFFSHORE. THE
ASSOCIATED E-NE LOW LEVEL FLOW IS ADVECTING PLENTY OF LOW/MID LEVEL
MOISTURE OVER THE CAROLINAS. EXPECT VFR CIGS 5-8KFT TO PREVAIL TODAY
WITH FEW/SCT MVFR CLOUDS DURING THE DAY. FCST SOUNDINGS AND GUIDANCE
INDICATE POCKETS OF MVFR CIGS MAY DEVELOP THIS MORNING...SO HAVE
INCLUDED TEMPO GROUPS TO ACCOUNT FOR THIS. THE BEST CHANCES FOR MVFR
WILL BE AT OUR SOUTHERN TERMINALS...AS MORE WIDESPREAD MVFR IS BEING
REPORTED DOWN TOWARD KCHS. NORTHEAST WINDS 6-10 KTS TODAY WILL
BECOME AOB 5 KTS AFTER 00Z FRIDAY. ABUNDANT LOW LEVEL MOISTURE MAY
SUPPORT FOG/STRATUS DEVELOPMENT OVERNIGHT...ESPECIALLY INLAND. WILL
INCLUDE MVFR VSBYS AFTER 06Z FOR ALL TAF SITES.
EXTENDED OUTLOOK...CHANCE OF SHOWERS/MVFR CIGS ON SATURDAY WITH A
COLD FRONT. VFR SUNDAY AND MONDAY. EXPECT GUSTY NORTH WINDS ON
SUNDAY BEHIND THE FRONT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...BASED ON THE MARINE OBSERVATIONS IT IS
IMPLIED THAT SMALL CRAFT CONDITIONS LIKELY CONTINUE ACROSS THE OUTER
COASTAL WATERS...EXCEPT FROM MURRELLS INLET TO LITTLE RIVER INLET.
CONDITIONS WILL SLOWLY IMPROVE AS THE WEAKENING COASTAL TROUGH
SHIFTS FARTHER WEST. MAY NEED TO REFINE THE ENDING TIME OF THE
REMAINING SMALL CRAFT AREAS BASED ON TRENDS HEADING INTO THIS
AFTERNOON...BUT UNTIL THEN CHOPPY SEAS WILL CONTINUE WITH THE
NORTHEAST TO EAST FETCH THAT HAS BEEN IN PLACE. WIDELY SCATTERED
SHOWERS WILL PRIMARILY AFFECT THE OUTER COASTAL WATERS THROUGH MOST
OF THE DAY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...THE PROLONGED NORTHEAST FLOW WILL BE ABATING
AT THE BEGINNING OF THE PERIOD AS SURFACE HIGH PRESSURE WEAKENS AND
ELONGATES WEST TO EAST. A WEAK SOUTH TO SOUTHWEST TO EVENTUALLY
WESTERLY FLOW WILL THEN TAKE PLACE. SPEEDS WILL REMAIN TEPID AROUND
TEN KNOTS. SATURDAY EVENING THE FRONT WILL CROSS THE WATERS AND BY
0600 UTC SUNDAY ELEMENTS WILL BE VERY DIFFERENT FROM JUST A FEW
HOURS EARLIER AS NORTH WINDS OF 25-30 KNOTS DEVELOP. A BRIEF GALE
WARNING CANNOT BE RULED OUT. SEAS OF COURSE WILL BE BENIGN FOR MOST
OF THE PERIOD BUT RAMPING UP QUICKLY ESPECIALLY ACROSS THE OUTER
WATERS LATE WITH THE RAPID INCREASE IN WIND SPEEDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...POTENT COLD AIR ADVECTION WILL DOMINATE THE
COASTAL WATERS SUNDAY WITH NORTH WINDS OF 20-25 KNOTS. WITH THE
PROGRESSIVE PATTERN...THE SURFACE HIGH WILL QUICKLY MOVE ACROSS THE
WATERS MONDAY WITH NORTHEAST WINDS DOWN TO 10-15 KNOTS AND EVEN LESS
BY THE END OF THE DAY. SEAS WILL BE HIGH SUNDAY BUT CONFINED TO THE
OUTER WATERS CONSIDERING THE FETCH WITH A SMALL CRAFT ADVISORY
LIKELY CONTINUING. MONDAY SEAS DROP TO 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
AMZ250-252-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
659 AM EST THU NOV 21 2013
.SYNOPSIS...
A WEAK TROUGH WILL AFFECT THE NORTH CAROLINA COAST TODAY. STRONG HIGH
PRESSURE WILL LINGER NORTH AND EAST OF THE AREA TONIGHT AND FRIDAY.
A STRONG COLD FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT AND MOVE
OFFSHORE SATURDAY AND SATURDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD
IN FROM THE NORTHWEST SUNDAY AND MONDAY. LOW PRESSURE WILL APPROACH
FROM THE SOUTHWEST TUESDAY AND CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 650 AM THURSDAY...A WEAK INVERTED TROUGH CONTINUES TO
PRODUCE SHOWERS FROM THE SOUTHERN COASTAL SECTION AND THEN NORTH
ALONG THE HIGHWAY 17 CORRIDOR. PER THE LATEST RAP AND HRR-R 4 KM
MODEL...THESE SHOWERS WILL CONTINUE INTO THE AFTERNOON. AMOUNTS
WILL BE LIGHT...LARGELY ONE-TENTH OF AN INCH OR LESS. HAVE KEPT
POPS IN THE 20 TO 30 PCT RANGE GIVEN THE LIGHT NATURE OF THE
SHOWERS. HAVE ALSO BEEFED UP CLOUD COVER ACROSS THE REGION FOR THE
REMAIN OF THE DAY...AND ACCORDINGLY HAVE LOWERED MAXIMUM
TEMPERATURES A COUPLE OF DEGREES AS WELL...GIVEN THE CLOUDINESS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
AS OF 310 AM THURSDAY...THE THREAT OF ANY PRECIPITATION SHOULD END
BY THIS EVENING...WITH SOME PARTIAL CLEARING OVERNIGHT. THE AXIS
OF THE SURFACE RIDGE WILL SETTLE OVER THE AREA TONIGHT...BUT WITH
A LIGHT ONSHORE FLOW...MINIMUM TEMPERATURES WILL RANGE IN THE
UPPER 40S TO MID 50S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 3 AM THU...00Z GFS/ECMWF IN GOOD AGREEMENT THROUGH THE END
OF THE WEEK. UPPER RIDGE OVER THE REGION BECOMES ZONAL AS POWERFUL
UPPER TROF BEGINS TO MOVE TOWARD THE SOUTHEAST...WHILE AT THE
SURFACE THE HIGH OVER THE CAROLINAS WILL MOVE SOUTHEAST. THE STRONG
COLD FRONT SWEEPS THROUGH ON SATURDAY. PREFER THE TIMING OF THE
FRONTAL PASSAGE FROM THE ECMWF AS IT MATCHES UP WELL WITH THE HPC
SOLUTION. GFS APPEARS ABOUT 6 HOURS TOO FAST. THE FRONT WILL ENTER
THE NORTHERN COUNTIES AROUND 12Z AND WILL BE SOUTH OF THE ENTIRE
AREA BY 00Z SUNDAY. GOOD LIFT AND CONVERGENCE ALONG THE FRONT.
HAVE KEPT POPS AT 40%. MUCH COLDER AND DRIER AIRMASS QUICKLY
OVERSPREADS THE REGION BEHIND THE FRONT. LIKE THE LAST ARCTIC
BLAST NOT TOO LONG AGO IT APPEARS THIS ONE WILL NOT BE AROUND FOR
VERY LONG EITHER. THE SURFACE RIDGE OVER THE NORTHERN PLAINS
SATURDAY WILL BE OVER THE CAROLINAS MONDAY THEN OFF THE COAST
TUESDAY...SO COLD NORTHERLY FLOW SATURDAY WILL BECOME SOUTHERLY ON
TUESDAY. RESULTING HIGHS WILL BE ONLY IN THE LOWER TO MID 40S
SUNDAY BUT WARMING QUICKLY TO THE MID AND UPPER 50S ON TUESDAY.
MODELS NOT HANDLING VERY WELL THE SYSTEM HEADING OUT OF THE GULF
NEXT WEEK. LOOKS LIKE THE ECMWF HAS A SLIGHT EDGE AT THE SURFACE
WHEN COMPARED TO THE HPC SOLUTION. HAVE RAISED POPS TO 40-50
PERCENT TUESDAY AND 50 PERCENT FOR WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 655 AM THU...PATCHY SHOWERS ARE AFFECTING EASTERN PORTIONS
OF THE CWA...INCLUDING THE KEWN AIRPORT. SOME LIGHT RAIN MAY ALSO
IMPACT THE OTHER THREE TAF SITES. ANY CEILINGS SHOULD REMAIN AOA
3000 FEET AS AREA OF BROKEN MID AND HIGH CLOUDS WILL OVERSPREAD
THE AREA FROM THE WEST AS THE DAY WEARS ON. SOME BREAKS IN THE
CLOUDS COUPLED WITH A LOW-LEVEL INVERSION MAY LEAD TO SOME PATCHY
FOG LATE TONIGHT AND HAVE INCLUDED MVFR LEVEL FOG AT ALL TAF SITES
LATER TONIGHT/EARLY FRIDAY MORNING.
LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM THU...VFR THROUGH FRIDAY. THE EXCEPTION WILL BE A FEW
HOURS EITHER SIDE OF 12Z FRIDAY AND SATURDAY WITH THE POSSIBILITY
OF SOME VFR/MVFR FOG. SCATTERED SHOWERS EXPECTED ON SATURDAY AHEAD
OF A STRONG COLD FRONT WITH MVFR CIGS/VSBYS. THE FRONT WILL PASS
THROUGH FROM THE NORTH DURING THE DAY WITH WINDS RAPIDLY VEERING
FROM SOUTHWEST IN THE MORNING TO DUE NORTH BY LATE AFTERNOON. MUCH
DRIER AND COLDER AIRMASS QUICKLY OVERSPREADS THE REGION BEHIND THE
FRONT. SKIES WILL BECOME CLEAR/VFR EARLY SATURDAY EVENING. BREEZY
CONDITIONS EXPECTED SUNDAY WITH NORTH WINDS 15-25 KNOTS. SURFACE
RIDGE WILL BUILD TOWARD THE AREA MONDAY. VFR CONDITIONS CONTINUE
WITH HIGH CLOUD DECK FILTERING IN DURING THE DAY AND GRADUALLY
LOWERING ALONG WITH LIGHT AND VARIABLE WINDS.
&&
.MARINE...
.SHORT TERM /TODAY AND TONIGHT/...
AS OF 7 AM THURSDAY...NOT MUCH CHANGE TO THE MARINE CONDITIONS AT
THIS TIME. WINDS ARE GENERALLY E/NE AT 10 TO 15 KNOTS ON ALL
WATERS. SEAS REMAIN AT 6 TO 7 FEET AT ALL LOCATIONS SO NO CHANGES
TO THE CURRENT SMALL CRAFT ADVISORY STATUS. SEAS SHOULD SLOW
SUBSIDE TO 5 FEET OR LESS BY LATE TONIGHT AS EASTERLY WINDS DROP
TO 10 KNOTS OR LESS OVER MOST OF THE COASTAL WATERS AND SOUNDS.
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM THU...USED A BLEND OF THE 00Z GFS/ECMWF FOR THE MARINE
WINDS THROUGH FRIDAY NIGHT. GFS IS RUNNING AROUND 6 HOURS TOO FAST
WITH THE TIMING OF THE FRONT ON SATURDAY AND PREFER THE ECMWF. THE
SURFACE RIDGE ALONG THE EAST COAST FRIDAY WILL QUICKLY MOVE
SOUTHEAST OFF THE COAST FRIDAY NIGHT. FRIDAY APPEARS TO BE THE
BEST BOATING DAY IN THE LONG TERM PORTION OF THE FORECAST. EAST
FLOW FRIDAY MORNING WILL BECOME SOUTHERLY IN THE AFTERNOON THEN
SOUTHWEST FRIDAY NIGHT AND CONTINUING INTO SATURDAY. WINDS WILL
AVERAGE 5-10 KNOTS AND SEAS 2-4 FEET FRIDAY. WINDS AND SEAS WILL
GRADUALLY INCREASE AFTER THAT FRIDAY NIGHT INTO SATURDAY AS A
STRONG COLD FRONT APPROACHES. THE FRONT WILL ENTER THE NORTHERN
WATERS SATURDAY AROUND 12Z...MOVE THROUGH THE CENTRAL WATERS
AROUND 18Z AND WILL BE SOUTH OF THE SOUTHERN WATERS BY 00Z SUNDAY.
STRONG SMALL CRAFT CONDITIONS WILL DEVELOP QUICKLY BEHIND THE
FRONT SPREADING ACROSS THE MARINE ZONES FROM NORTH TO SOUTH
SATURDAY NIGHT. CONDITIONS WILL IMPROVE EARLY NEXT WEEK AS A
SURFACE RIDGE BUILDS INTO THE AREA WITH WINDS/SEAS DIMINISHING AS
A RESULT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...HSA
AVIATION...CTC/HSA
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
625 AM EST THU NOV 21 2013
.SYNOPSIS...
A COASTAL TROUGH WILL BRING PERIODS OF ATLANTIC CLOUD COVER ONSHORE
THROUGH FRIDAY. A COLD FRONT WILL CROSS THE AREA LATE SATURDAY
FOLLOWED BY A BRIEF PERIOD OF VERY COLD AIR. A SIGNIFICANT RAIN
EVENT IS BECOMING MORE LIKELY TOWARD THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...DRY RIDGING AT 700 AND 500 MILLIBARS USUALLY
IMPLIES BENIGN WEATHER DOWN HERE AT THE SURFACE. NOT SO THIS TIME AS
A TIGHT PRESSURE GRADIENT AROUND THE SOUTHERN PERIPHERY OF 1038 MB
HIGH PRESSURE OVER NEW ENGLAND...PLUS A WEAK COASTAL TROUGH OUT NEAR
THE GULF STREAM ARE ADVECTING ATLANTIC MOISTURE ONSHORE. THIS
MOISTURE EXTENDS VERTICALLY TO AROUND 8000 FEET AT WHICH POINT A
SIGNIFICANT LAYER OF DRY AIR EXISTS WITHIN THE WESTERLY FLOW ALOFT.
AS WAS TRUE ON THE 00Z MODEL RUNS...THERE ARE STILL UNANSWERED BASIC
QUESTIONS CONCERNING TODAY`S FORECAST USING THE 06Z RUNS. THE AMOUNT
OF LOW CLOUD COVER THAT REMAINS INTO THE AFTERNOON WILL LARGELY
DETERMINE OUR TEMPERATURES. ANY ISENTROPIC LIFT IS SITUATED VERY LOW
IN THE ATMOSPHERE AND BECOMES QUITE WEAK BY AFTERNOON. THERE IS
NEARLY A TEN-DEGREE DIFFERENCE BETWEEN THE 00Z NAM AND GFS
INLAND...AND NO CLEAR SIGNAL WHICH MODEL...IF EITHER...IS RIGHT. THE
WEDGE PATTERN TO THE PRESSURE AND WIND FIELDS ACROSS THE CAROLINAS
IMPLIES THE COOLER GFS MAY BE THE WAY TO GO...ALTHOUGH I WOULD FEEL
MORE CONFIDENT IN THIS DECISION IF THERE WERE RAIN AND/OR WIDESPREAD
LOW STRATUS ACROSS CENTRAL NORTH CAROLINA TO HELP OFFSET INSOLATION.
THE 06Z RUNS ESSENTIALLY MIRRORED THEIR 00Z COUNTERPARTS...BUT THE
LATEST RUC AND HRRR HAVE COME FIRMLY INTO LINE WITH THE WARMER 00Z
AND 06Z NAM.
THE AIRMASS IS MODIFYING QUICKLY OVERHEAD WITH WARM ADVECTION IN THE
800-950 MB LAYER ADDING A GOOD 2-3 DEGREES C THROUGH THIS EVENING.
ALONG THIS COAST THIS SHOULD YIELD HIGHS IN THE UPPER 60S...PERHAPS
EVEN SQUEAKING OUT A 70 DEGREE READING HERE AND THERE AWAY FROM THE
BEACHES. FARTHER INLAND IS WHERE LARGER QUESTIONS REMAIN. WITH LOW
CONFIDENCE I AM FORECASTING HIGHS IN THE 62-64 RANGE ALONG THE I-95
CORRIDOR...60-61 FOR BENNETTSVILLE AND DARLINGTON...AND 64-67 FROM
ELIZABETHTOWN AND WHITEVILLE THROUGH MARION...LAKE CITY AND
KINGSTREE.
ALTHOUGH RADAR SHOWS A BAND OF SHOWERS ALONG THE WESTERN EDGE OF THE
GULF STREAM...PROBABILITIES OF MEASURABLE RAIN ARE LOW TODAY GIVEN
POOR ISENTROPIC LIFT SHOWN ON ANY MODEL. LINEAR EXTRAPOLATION OF THE
SHOWERS SHOULD HAVE ALREADY PUSHED THEM ONSHORE HOURS AGO...
INDICATING LOCAL ENVIRONMENTAL CONDITIONS OUT AT THE EDGE OF THE
GULF STREAM ARE PROBABLY KEY TO SUSTAINING THIS ACTIVITY. I AM
INCLUDING A 20 POP NEAR THE COAST LATER TODAY JUST IN CASE SOMETHING
SNEAKS IN OFF THE WATER DURING THE BEST WARM ADVECTION AROUND NOON.
WIND FIELDS SHOULD WEAKEN TONIGHT AS THE HIGH OVER NEW ENGLAND
RAPIDLY WEAKENS AND SHIFTS OFFSHORE. PLENTY OF LOW LEVEL ATLANTIC
MOISTURE WILL MODERATE TEMPERATURES...AND LOWS SHOULD RANGE FROM
AROUND 50 IN LUMBERTON TO THE MID 50S AT THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE FORECAST CHALLENGE CONTINUES TO THE BE
THE WEAK FORCING AND MOISTURE ASSOCIATED WITH A COASTAL TROUGH
FRIDAY THEN THE MOISTURE WITH A LONG ADVERTISED FRONT MOVING ACROSS
LATE SATURDAY/EARLY SUNDAY. THE GUIDANCE HAS WALKED BACK MOISTURE
WITH THE COASTAL TROUGH FRIDAY AND WITH THE ERRATIC NATURE OF THESE
TYPE OF FEATURES AND VOLATILITY OF GUIDANCE...THE BEST OPTION IS TO
KEEP POPS AS THEY ARE. FOR SATURDAY I HAVE FINE TUNED POPS TO
EMPHASIZE THE AFTERNOON AND EVENING HOURS PER THE LATEST MODEL
GUIDANCE. AS FOR TEMPERATURES...THE MET NUMBERS ARE WARMER ACROSS
THE BOARD AND GENERALLY LEANED TOWARD THESE NUMBERS THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...THE EXTENDED FORECAST LOOKS TO BE VERY
ACTIVE WITH THE EMPHASIS NOW SHIFTING TO THE END OF THE PERIOD WHEN
A CUTOFF LOW OUT WEST OPENS UP AND MOVES ACROSS THE SOUTHEAST.
SUNDAY AND MONDAY ARE FAIRLY CLEAR CUT AS COLD AIR ADVECTION
DOMINATES WITH TEMPERATURES MOST LIKELY NOT GETTING OUT OF THE 40S
SUNDAY AND DEPENDING ON DECOUPLING...MONDAY MORNINGS LOWS WELL INTO
THE 20S. FOR TUESDAY AND WEDNESDAY...THE LOW TAKES SHAPE IN THE GULF
OF MEXICO WITH A RELATIVELY WEAK AND FLEETING COLD AIR WEDGE HANGING
ON. ISENTROPIC LIFT DEVELOPS IN EARNEST LATE TUESDAY. THE LOW
ATTEMPTS TO REDEVELOP ALONG THE COASTAL FRONT WEDNESDAY BUT AT LEAST
AT THIS POINT DOESN/T BECOME DOMINANT. TOUGH CALL ON MILLER A OR B
SCENARIO HOWEVER THIS FAR OUT THIS IS HAGGLING OVER DETAILS AND RAIN
WILL CONTINUE WEDNESDAY AS THE MID LEVEL SYSTEM MOVES ACROSS. WE
HAVE FAIRLY HIGH POPS FOR TUESDAY AND ESPECIALLY WEDNESDAY ALREADY
SO I ONLY INCREMENTALLY INCREASED POPS. NO CHANGES TO TEMPERATURE
FORECAST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SURFACE ANALYSIS THIS MORNING SHOWS HIGH PRESSURE
WEDGING DOWN FROM NEW ENGLAND AND A COASTAL TROUGH OFFSHORE. THE
ASSOCIATED E-NE LOW LEVEL FLOW IS ADVECTING PLENTY OF LOW/MID LEVEL
MOISTURE OVER THE CAROLINAS. EXPECT VFR CIGS 5-8KFT TO PREVAIL TODAY
WITH FEW/SCT MVFR CLOUDS DURING THE DAY. FCST SOUNDINGS AND GUIDANCE
INDICATE POCKETS OF MVFR CIGS MAY DEVELOP THIS MORNING...SO HAVE
INCLUDED TEMPO GROUPS TO ACCOUNT FOR THIS. THE BEST CHANCES FOR MVFR
WILL BE AT OUR SOUTHERN TERMINALS...AS MORE WIDESPREAD MVFR IS BEING
REPORTED DOWN TOWARD KCHS. NORTHEAST WINDS 6-10 KTS TODAY WILL
BECOME AOB 5 KTS AFTER 00Z FRIDAY. ABUNDANT LOW LEVEL MOISTURE MAY
SUPPORT FOG/STRATUS DEVELOPMENT OVERNIGHT...ESPECIALLY INLAND. WILL
INCLUDE MVFR VSBYS AFTER 06Z FOR ALL TAF SITES.
EXTENDED OUTLOOK...CHANCE OF SHOWERS/MVFR CIGS ON SATURDAY WITH A
COLD FRONT. VFR SUNDAY AND MONDAY. EXPECT GUSTY NORTH WINDS ON
SUNDAY BEHIND THE FRONT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...THE PRESSURE GRADIENT ALONG THE SOUTHERN
PERIPHERY OF STRONG HIGH PRESSURE OVER NEW ENGLAND IS FUELING OUR
STRONG NORTHEAST WINDS THIS MORNING. A WEAK COASTAL TROUGH OUT NEAR
THE GULF STREAM IS HELPING MAINTAIN NORTHEASTERLY WINDS RATHER THAN
EASTERLY. WIND SPEEDS WILL GRADUALLY DIMINISH...BUT IT WILL TAKE
TIME FOR MARINE CONDITIONS TO SIGNIFICANTLY IMPROVE. SMALL CRAFT
ADVISORY CONDITIONS (BOTH WINDS AND SEAS) SHOULD CONTINUE THROUGH
LATE THIS EVENING FOR ALL BUT THE PROTECTED PORTION OF LONG BAY
WHERE LOWER WINDS AND SEAS SHOULD ALLOW THE ADVISORY TO BE DROPPED
LATER THIS MORNING.
BY TONIGHT THE STRONG HIGH OVER NEW ENGLAND SHOULD RAPIDLY WEAKEN AS
IT PUSHES EAST INTO THE ATLANTIC. THIS WILL RESULT IN A TREND TOWARD
LIGHTER WIND SPEEDS LOCALLY...AND EVENTUALLY LOWER SEA HEIGHTS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...THE PROLONGED NORTHEAST FLOW WILL BE ABATING
AT THE BEGINNING OF THE PERIOD AS SURFACE HIGH PRESSURE WEAKENS AND
ELONGATES WEST TO EAST. A WEAK SOUTH TO SOUTHWEST TO EVENTUALLY
WESTERLY FLOW WILL THEN TAKE PLACE. SPEEDS WILL REMAIN TEPID AROUND
TEN KNOTS. SATURDAY EVENING THE FRONT WILL CROSS THE WATERS AND BY
0600 UTC SUNDAY ELEMENTS WILL BE VERY DIFFERENT FROM JUST A FEW
HOURS EARLIER AS NORTH WINDS OF 25-30 KNOTS DEVELOP. A BRIEF GALE
WARNING CANNOT BE RULED OUT. SEAS OF COURSE WILL BE BENIGN FOR MOST
OF THE PERIOD BUT RAMPING UP QUICKLY ESPECIALLY ACROSS THE OUTER
WATERS LATE WITH THE RAPID INCREASE IN WIND SPEEDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...POTENT COLD AIR ADVECTION WILL DOMINATE THE
COASTAL WATERS SUNDAY WITH NORTH WINDS OF 20-25 KNOTS. WITH THE
PROGRESSIVE PATTERN...THE SURFACE HIGH WILL QUICKLY MOVE ACROSS THE
WATERS MONDAY WITH NORTHEAST WINDS DOWN TO 10-15 KNOTS AND EVEN LESS
BY THE END OF THE DAY. SEAS WILL BE HIGH SUNDAY BUT CONFINED TO THE
OUTER WATERS CONSIDERING THE FETCH WITH A SMALL CRAFT ADVISORY
LIKELY CONTINUING. MONDAY SEAS DROP TO 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
AMZ250-252-256.
SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR AMZ254.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
312 AM EST THU NOV 21 2013
.SYNOPSIS...
A WEAK TROUGH WILL AFFECT THE NORTH CAROLINA COAST TODAY. STRONG HIGH
PRESSURE WILL LINGER NORTH AND EAST OF THE AREA TONIGHT AND FRIDAY.
A STRONG COLD FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT AND MOVE
OFFSHORE SATURDAY AND SATURDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD
IN FROM THE NORTHWEST SUNDAY AND MONDAY. LOW PRESSURE WILL APPROACH
FROM THE SOUTHWEST TUESDAY AND CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 310 AM THURSDAY...WITH A WEAK INVERTED TROUGH OFFSHORE...AND
AN ONSHORE FLOW BELOW 850 MB...SHOWERS HAVE BECOME A BIT MORE
WIDESPREAD OVER THE PAST COUPLE OF HOURS. THIS IS BEING BEST
HANDLED BY THE RAP MODEL...WHICH SHOWS THIS LIGHT RAINFALL
LINGERING IN THE AREA THROUGH ALOT OF THE DAY. AS A RESULT WILL
HAVE 20 TO 30 PCT POPS OVER MOST OF THE AREA FOR THE BALANCE OF
THE OVERNIGHT AND DAYTIME HOURS. WITH THE WARMER ONSHORE
FLOW...MAXIMUM TEMPERATURES WILL BE WELL INTO THE 60S OVER MOST OF
THE AREA TODAY. WINDS WILL DECREASE AS THE GRADIENT DIMINISHES
WITH A PIECE OF THE LARGE SURFACE HIGH BREAKING OFF OVER
SOUTHEASTERN VIRGINIA/NORTHEASTERN NORTH CAROLINA LATER TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
AS OF 310 AM THURSDAY...THE THREAT OF ANY PRECIPITATION SHOULD END
BY THIS EVENING...WITH SOME PARTIAL CLEARING OVERNIGHT. THE AXIS
OF THE SURFACE RIDGE WILL SETTLE OVER THE AREA TONIGHT...BUT WITH
A LIGHT ONSHORE FLOW...MINIMUM TEMPERATURES WILL RANGE IN THE
UPPER 40S TO MID 50S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 3 AM THU...00Z GFS/ECMWF IN GOOD AGREEMENT THROUGH THE END
OF THE WEEK. UPPER RIDGE OVER THE REGION BECOMES ZONAL AS POWERFUL
UPPER TROF BEGINS TO MOVE TOWARD THE SOUTHEAST...WHILE AT THE
SURFACE THE HIGH OVER THE CAROLINAS WILL MOVE SOUTHEAST. THE STRONG
COLD FRONT SWEEPS THROUGH ON SATURDAY. PREFER THE TIMING OF THE
FRONTAL PASSAGE FROM THE ECMWF AS IT MATCHES UP WELL WITH THE HPC
SOLUTION. GFS APPEARS ABOUT 6 HOURS TOO FAST. THE FRONT WILL ENTER
THE NORTHERN COUNTIES AROUND 12Z AND WILL BE SOUTH OF THE ENTIRE
AREA BY 00Z SUNDAY. GOOD LIFT AND CONVERGENCE ALONG THE FRONT.
HAVE KEPT POPS AT 40%. MUCH COLDER AND DRIER AIRMASS QUICKLY
OVERSPREADS THE REGION BEHIND THE FRONT. LIKE THE LAST ARCTIC
BLAST NOT TOO LONG AGO IT APPEARS THIS ONE WILL NOT BE AROUND FOR
VERY LONG EITHER. THE SURFACE RIDGE OVER THE NORTHERN PLAINS
SATURDAY WILL BE OVER THE CAROLINAS MONDAY THEN OFF THE COAST
TUESDAY...SO COLD NORTHERLY FLOW SATURDAY WILL BECOME SOUTHERLY ON
TUESDAY. RESULTING HIGHS WILL BE ONLY IN THE LOWER TO MID 40S
SUNDAY BUT WARMING QUICKLY TO THE MID AND UPPER 50S ON TUESDAY.
MODELS NOT HANDLING VERY WELL THE SYSTEM HEADING OUT OF THE GULF
NEXT WEEK. LOOKS LIKE THE ECMWF HAS A SLIGHT EDGE AT THE SURFACE
WHEN COMPARED TO THE HPC SOLUTION. HAVE RAISED POPS TO 40-50
PERCENT TUESDAY AND 50 PERCENT FOR WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 1245 AM THU...DECK OF CLOUDS AROUND 4000 FEET WILL LINGER
THROUGH THE OVERNIGHT HOURS...ALTHOUGH A BRIEF PERIOD OF MVFR
CEILINGS MAY OCCUR...ESPECIALLY AT KOAJ. SOME LIGHT SHOWERS ARE
OCCURRING BUT THEY WILL BE LIGHT AND SHOULD NOT AFFECT CEILINGS OR
VSBYS VERY MUCH. NOT MUCH CHANGE IN THE CEILING HEIGHT IS EXPECTED
DURING THURSDAY AS GENERALLY VFR CONDITIONS CONTINUE. EXPECT A
BROKEN DECK AROUND 10000 FEET BY TONIGHT.
LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM THU...VFR THROUGH FRIDAY. THE EXCEPTION WILL BE A FEW
HOURS EITHER SIDE OF 12Z FRIDAY AND SATURDAY WITH THE POSSIBILITY
OF SOME VFR/MVFR FOG. SCATTERED SHOWERS EXPECTED ON SATURDAY AHEAD
OF A STRONG COLD FRONT WITH MVFR CIGS/VSBYS. THE FRONT WILL PASS
THROUGH FROM THE NORTH DURING THE DAY WITH WINDS RAPIDLY VEERING
FROM SOUTHWEST IN THE MORNING TO DUE NORTH BY LATE AFTERNOON. MUCH
DRIER AND COLDER AIRMASS QUICKLY OVERSPREADS THE REGION BEHIND THE
FRONT. SKIES WILL BECOME CLEAR/VFR EARLY SATURDAY EVENING. BREEZY
CONDITIONS EXPECTED SUNDAY WITH NORTH WINDS 15-25 KNOTS. SURFACE
RIDGE WILL BUILD TOWARD THE AREA MONDAY. VFR CONDITIONS CONTINUE
WITH HIGH CLOUD DECK FILTERING IN DURING THE DAY AND GRADUALLY
LOWERING ALONG WITH LIGHT AND VARIABLE WINDS.
&&
.MARINE...
.SHORT TERM /TODAY AND TONIGHT/...
AS OF 315 AM THURSDAY...N/NE WINDS ARE GENERALLY 15 KNOTS OR LESS
CURRENTLY AS WINDS CONTINUE TO TREND DOWNWARD. SEAS AT ALL OF THE
PLATFORMS REMAIN AT 6 TO 7 FEET...SO A SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT FOR TODAY...ENDING FROM NORTH TO SOUTH AS THE
DAYS WEARS ON. SEAS SHOULD SLOW SUBSIDE TO 5 FEET OR LESS BY LATE
TONIGHT AS EASTERLY WINDS DROP TO 10 KNOTS OR LESS OVER MOST OF
THE COASTAL WATERS AND SOUNDS.
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM THU...USED A BLEND OF THE 00Z GFS/ECMWF FOR THE MARINE
WINDS THROUGH FRIDAY NIGHT. GFS IS RUNNING AROUND 6 HOURS TOO FAST
WITH THE TIMING OF THE FRONT ON SATURDAY AND PREFER THE ECMWF. THE
SURFACE RIDGE ALONG THE EAST COAST FRIDAY WILL QUICKLY MOVE
SOUTHEAST OFF THE COAST FRIDAY NIGHT. FRIDAY APPEARS TO BE THE
BEST BOATING DAY IN THE LONG TERM PORTION OF THE FORECAST. EAST
FLOW FRIDAY MORNING WILL BECOME SOUTHERLY IN THE AFTERNOON THEN
SOUTHWEST FRIDAY NIGHT AND CONTINUING INTO SATURDAY. WINDS WILL
AVERAGE 5-10 KNOTS AND SEAS 2-4 FEET FRIDAY. WINDS AND SEAS WILL
GRADUALLY INCREASE AFTER THAT FRIDAY NIGHT INTO SATURDAY AS A
STRONG COLD FRONT APPROACHES. THE FRONT WILL ENTER THE NORTHERN
WATERS SATURDAY AROUND 12Z...MOVE THROUGH THE CENTRAL WATERS
AROUND 18Z AND WILL BE SOUTH OF THE SOUTHERN WATERS BY 00Z SUNDAY.
STRONG SMALL CRAFT CONDITIONS WILL DEVELOP QUICKLY BEHIND THE
FRONT SPREADING ACROSS THE MARINE ZONES FROM NORTH TO SOUTH
SATURDAY NIGHT. CONDITIONS WILL IMPROVE EARLY NEXT WEEK AS A
SURFACE RIDGE BUILDS INTO THE AREA WITH WINDS/SEAS DIMINISHING AS
A RESULT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...HSA
AVIATION...CTC/HSA
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1242 AM EST THU NOV 21 2013
.SYNOPSIS...
STRONG HIGH PRESSURE WILL EXTEND SOUTHWEST INTO THE REGION THROUGH
THURSDAY THEN MOVE OFFSHORE FRIDAY. A COLD FRONT WILL APPROACH
FROM THE WEST FRIDAY NIGHT AND MOVE OFFSHORE LATE SATURDAY. STRONG
HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND MONDAY.
LOW PRESSURE WILL APPROACH FROM THE SOUTHWEST TUESDAY AND CROSS
THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1240 AM THURSDAY...WEAK INVERTED TROUGH OFFSHORE IS LEADING
TO SOME LIGHT SHOWERS OFF CORE BANKS AND THE SOUTHERN PORTION OF
THE OUTER BANKS. THE RAP AND 4KM WRF MODELS INDICATE THAT SOME OF
THIS PRECIPITATION WILL REACH LAND AREAS OVERNIGHT AND HAVE ADDED
A SLIGHT POP TO THE FORECAST BASICALLY FROM CAPE LOOKOUT TO CAPE
HATTERAS. ANY RAINFALL AMOUNTS WILL BE VERY LIGHT. MID AND HIGH
CLOUDS WILL CONTINUE TO STREAM OVER THE AREA FROM THE WEST
OVERNIGHT AND TEMPERATURES WILL LIKELY ONLY FALL A COUPLE OF MORE
DEGREES BY MORNING.
&&
.SHORT TERM /FRIDAY/...
AS OF 210 PM WEDNESDAY...WL CONT TO SEE PLENTY OF CLOUDS OVER THE
AREA WITH MOISTURE BELOW 10000 FT PER ONSHORE FLOW AROUND HIGH PRES.
HGTS ALOFT WILL BE RISING SO NOT EXPECTING PRECIP OVER LAND WITH
NO FORCING. WILL SEE ENOUGH PEAKS OF SUN FOR HIGHS 60 TO 65. GRDNT
IS MUCH WEAKER ALONG THE CST THU AND EXPECT WINDS MAINLY IN THE 10
TO 15 MPH RANGE ESPCLY LATER IN THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WED...HIGH PRESSURE TO THE NORTH WILL REMAIN IN
CONTROL THU NIGHT THROUGH FRI. WILL CONTINUE TO KEEP FORECAST
DRY...THOUGH MODELS SHOW LOW LEVEL MOISTURE INCREASING AND
POSSIBLE LIGHT SHOWERS ALONG THE SOUTHERN ZONES. FRI AND SAT
EXPECT TEMPS NEAR CLIMO...WITH RETURN FLOW RE-
DEVELOPING...GENERALLY 65-70 DEGREES. A COLD FRONT WILL APPROACH
EASTERN NC FRI NIGHT...MOVING THROUGH THE AREA SATURDAY. WILL
MAINTAIN CHANCE POPS SAT THROUGH SAT EVENING...TAPERING OFF FROM W
TO E SAT NIGHT. COLD HIGH PRESSURE WILL BUILD IN FROM THE WEST
SUN/MON AS UPPER TROUGH MOVES OFF THE EASTERN US. A FEW COLD DAYS
EXPECTED WITH LOW LEVEL THICKNESS VALUES SUPPORTING HIGH TEMPS
GENERALLY IN THE 40S...ABOUT 20 DEGREES BELOW CLIMO. OVERNIGHT
LOWS SUN NIGHT/MON MORNING LIKELY IN THE 20S/MID 30S. COULD HAVE
POTENTIAL FOR FROST/FREEZE ALONG THE OUTER BANKS.
A LOW PRESSURE SYSTEM WILL DEVELOP IN THE GULF OF MEXICO
TUESDAY...AND MOVE THROUGH THE SE US TUESDAY AND WEDNESDAY. ECMWF
AND GFS CONTINUE TO DIFFER IN SPECIFIC DETAILS...MAINLY
TIMING...TRACK AND STRENGTH. WPC CONTINUES TO FAVOR THE SLOWER
SOLUTION LEANING SLIGHTLY CLOSER TO THE GFS...SO WILL LEAN TOWARDS
THAT FOR NOW. GOOD RAIN CHANCES EXPECTED WITH THIS SYSTEM...AND
INCREASED POPS TO HIGH CHANCE FOR TUE NIGHT/WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SHORT TERM /TONIGHT AND THU/...
AS OF 1245 AM THU...DECK OF CLOUDS AROUND 4000 FEET WILL LINGER
THROUGH THE OVERNIGHT HOURS...ALTHOUGH A BRIEF PERIOD OF MVFR
CEILINGS MAY OCCUR...ESPECIALLY AT KOAJ. NOT MUCH CHANGE IN THE
CEILING HEIGHT IS EXPECTED DURING THURSDAY AS GENERALLY VFR
CONDITIONS CONTINUE.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 215 PM WED...PRED VFR CONDITIONS EXPECTED THROUGH FRI NIGHT.
BRIEF PATCHY FOG AND STRATUS WILL BE POSSIBLE THU NIGHT AND FRI
NIGHT WITH INCREASING LOW LEVEL MOISTURE. A COLD FRONT WILL MOVE
THROUGH THE AREA SAT WITH SCT SHOWERS DEVELOPING...PERIODS OF SUB-
VFR CONDITIONS WILL BE POSSIBLE SAT AND SAT NIGHT. HIGH PRESSURE
WILL BUILD OVER THE AREA SUN AND MON WITH PRED VFR CONDITIONS WITH
GUSTY N/NW WINDS SUN.
&&
.MARINE...
.SHORT TERM /THROUGH THU/...
AS OF 1245 AM THURSDAY...SEAS REMAIN IN THE 6 TO 7 FOOT RANGE AT
THE BUOYS ALONG THE COAST WITH THE BUOY 10 MILES NORTHEAST OF
DUCK...THE BUOY 13 MILES EAST OF OREGON INLET AND DIAMOND BUOY ALL
REPORTING 7 FEET. WINDS HAVE SUBSIDING TO GENERALLY 15 TO 20 KNOTS
AT ALL SITE. ON THUR AS THE HIGH TO THE N WEAKENS AND SHIFTS E
WILL CONT TO SEE WINDS DIMINISH WITH DIR BECOMING MORE
ENE...SPEEDS SHOULD BE AOB 15 KTS LATE. SEAS WILL SLOWLY SUBSIDE
WITH SCA ENDING LATE DAY OR EVENING ALL WTRS.
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 215 PM WED...HIGH PRESSURE TO THE NORTH WILL CONTINUE TO BE
THE DOMINANT FEATURE THROUGH FRI NIGHT. E/NE WINDS GENERALLY 10KT
OR LESS THU NIGHT THROUGH FRI...WITH WINDS VEERING BECOMING SWLY
FRI NIGHT INTO SAT. SWLY WINDS WILL INCREASE TO 10-20KT SAT AHEAD
OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL MOVE THROUGH THE
WATERS SAT EVENING. STRONG N/NW WINDS 15-25KT WILL DEVELOP BEHIND
THE FRONT LATE SAT NIGHT AND CONTINUE INTO SUN NIGHT. SEAS WILL
BUILD TO 4-8FT...HIGHEST NORTH OF OCRACOKE. SCA CONDITIONS
EXPECTED TO DEVELOP SAT EVENING AND CONTINUE THROUGH SUN NIGHT.
HIGH PRESSURE WILL BUILD OVER THE AREA SUN AND MON. NORTHERLY
WINDS WILL SLOWLY DIMINISH LATE SUN NIGHT AND BECOME SLY MON NIGHT
INTO TUE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF
LONG TERM...CQD
AVIATION...CTC/CQD
MARINE...CTC/CQD/RF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1251 AM CST THU NOV 21 2013
.UPDATE...
ISSUED AT 1251 AM CST THU NOV 21 2013
COLD HIGH PRESSURE CONTINUES TO PUSH INTO THE STATE FROM THE
NORTHWEST. CLEARING AT WILLISTON...AND WESTERN EDGE OF CLOUDS
EXPECTED TO MOVE EASTWARD DURING THE EARLY MORNING HOURS. LINGERING
FLURRIES FOR ANOTHER HOUR OR TWO FROM NEAR HETTINGER TO
BISMARCK/MANDAN TO HARVEY...LIGHT SNOW CONTINUING EAST OF THIS LINE
FOR 2-4 HOURS TAPERING TO FLURRIES. LITTLE ADDITIONAL ACCUMULATION
EXPECTED. TEMPERATURES AROUND ZERO IN CROSBY IN THE FAR NORTHWEST
CORNER OF NORTH DAKOTA. EXPECTING LOWS OF 5 BELOW TO NEAR 15 BELOW
IN THE FAR NORTHWEST CORNER THIS MORNING...WITH WIND CHILLS OF 20 TO
30 BELOW ZERO AND WILL KEEP THE CURRENT WIND CHILL ADVISORY GOING
FOR THE DIVIDE/WILLIAMS/BURKE/MOUNTRAIL COUNTY AREA.
UPDATE ISSUED AT 947 PM CST WED NOV 20 2013
DID ISSUE A WIND CHILL ADVISORY FOR THE NORTHWEST TONIGHT INTO
THURSDAY MORNING WITH WIND CHILLS OF -25 TO -30 EXPECTED.
TEMPERATURES WILL QUICKLY FALL BELOW ZERO ACROSS THE NORTHWEST BY
05 UTC AS SKIES CLEAR WITH FRESH SNOW AS THE SURFACE HIGH
CONTINUES TO BUILD INTO WESTERN NORTH DAKOTA.
UPDATE ISSUED AT 645 PM CST WED NOV 20 2013
UPDATE TO CANCEL THE WINTER WEATHER ADVISORY FOR
WILLIAMS...DUNN...MOUNTRAIL...MCKENZIE AND RENVILLE COUNTIES.
HOWEVER...A WIND CHILL ADVISORY MAY BE NEEDED TONIGHT ACROSS THE
NORTHWEST. WIND CHILL VALUES MAY APPROACH -25 AS A QUICK DROP OFF
IN SURFACE TEMPERATURES TO NEAR -10 ARE EXPECTED WITH THE NEW SNOW
COVER AND CLEARING SKIES.
UPDATE ISSUED AT 447 PM CST WED NOV 20 2013
QUICK UPDATE TO EXPAND THE WINTER WEATHER ADVISORY INTO
RENVILLE...TOWNER...BOTTINEAU...PIERCE AND ROLETTE COUNTIES.
HEAVY BANDED SNOW IS EXPECTED TO RESULT IN 3 TO 5 INCHES OF SNOW
FOR THESE AREAS WITH VISIBILITIES NEAR ONE QUARTER OF A MILE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
LATEST RADAR AND WEATHER CAMERAS INDICATE SNOW FROM WEST CENTRAL
INTO NORTH CENTRAL NORTH DAKOTA. SNOW HAS BEEN HEAVY AT TIMES WITH
VISIBILITY DOWN TO A QUARTER. LATEST REPORTS AND ESTIMATES INDICATE
1-2 INCHES HAS FALLEN FROM WILLISTON TO DICKINSON. LIKELY SOME
HIGHER AMOUNTS IN A PERSISTENT BAND ACROSS MAINLY MCKENZIE COUNTY.
THIS BAND HAS BECOMING MORE ENHANCED ACROSS MOUNTRAIL INTO WARD
COUNTY IN THE PAST HOUR.
EXPECT ANOTHER 2 TO 4 HOURS OF LIGHT TO MODERATE SNOW IN THE
ADVISORY AREA...BEFORE SHIFTING FARTHER SOUTH AND EAST. 12 UTC
MODEL GUIDANCE AND THE LATEST MESOSCALE RAP AND HRRR SHOW
PRECIPITATION ENDING QUICKLY AROUND 00 UTC IN WESTERN NORTH DAKOTA
AS BEST FRONTOGENETICAL FORCING SHIFTS INTO CENTRAL NORTH DAKOTA.
THIS SHOULD PUT AN END TO ACCUMULATING SNOW OVER THE ADVISORY AREA
BY MID EVENING. CURRENT HAZARD GOES UNTIL 10 PM AND EVENING SHIFT
CAN CANCEL EARLY IF NEEDED.
BEST SNOW CHANCES ARE OVER CENTRAL NORTH DAKOTA THIS EVENING. AND
ACCUMULATIONS OF AROUND AN INCH ARE POSSIBLE OVER THE SOUTH
CENTRAL AND FAR SOUTHWEST...FROM BOWMAN AND HETTINGER TO BISMARCK
AND JAMESTOWN. LESSER AMOUNTS...UNDER AN INCH ARE EXPECTED FROM
SELFRIDGE TO LAMOURE AND OAKES. MODEL SOUNDINGS INDICATE WARM
TEMPERATURES ALOFT IN THE FAR SOUTH CENTRAL...THUS HAVE INCLUDED A
MENTION OF MIXED PRECIPITATION SOUTH OF BISMARCK TO THE SOUTHERN
JAMES RIVER VALLEY.
PRECIPITATION ENDS QUICKLY IN THE CENTRAL AS THE UPPER TROUGH
TRANSLATES INTO THE AREA LATE TONIGHT. THEN WE ARE LOOKING AT VERY
COLD TEMPERATURES AND WIND CHILLS LATE TONIGHT AND THURSDAY. WIND
CHILLS FROM 10 BELOW SOUTH TO 20 BELOW NORTHWEST CAN BE EXPECTED
EARLY THURSDAY MORNING.
THURSDAY IS EXPECTED TO BE DRY BUT COLD WITH HIGHS OF 10 TO 20 ABOVE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE COLDEST AIR OF THE
SEASON THUS FAR FOR FRIDAY NIGHT INTO SATURDAY MORNING.
THE 12 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A WEAK
CLIPPER SYSTEM PROPAGATING NEAR THE INTERNATIONAL BORDER THURSDAY
NIGHT INTO FRIDAY MORNING. THIS IS FOLLOWED BY A 1050 MB HIGH
BUILDING ACROSS NORTH DAKOTA THROUGH THE REMAINDER OF THE DAY ON
FRIDAY. WHEN COMBINED WITH THE SNOW COVER THAT WILL BE ACROSS THE
NORTH...THE COLDEST NIGHT OF THE SEASON THUS FAR IS EXPECTED WITH
LOWS NEAR -15 NORTH...WITH THE SINGLE DIGITS BELOW ZERO ACROSS THE
SOUTH. DID UNDERCUT ALL GUIDANCE BY AT LEAST FIVE DEGREES ACROSS
THE SNOWPACK FOR LOWS FRIDAY NIGHT. WIND CHILLS MAY APPROACH
ADVISORY CRITERIA OF -25 TO -30 EARLY SATURDAY MORNING ACROSS THE
NORTH. HIGHS WARM BACK INTO THE 30S ON SUNDAY IN THE WARM SECTOR
OF A SOUTHERN CANADA CLIPPER. HOWEVER...THIS WARM UP IS BRIEF AS
ANOTHER COOL CANADIAN AIRMASS PROPAGATES SOUTH EARLY NEXT WEEK
UNDER NORTHWEST FLOW ALOFT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1251 AM CST THU NOV 21 2013
IFR CONDITIONS IN SNOW AT KJMS THROUGH 10Z...THEN MVFR THROUGH 15Z.
MVFR STRATUS AT KBIS THROUGH 10 UTC. OTHERWISE....CONDITIONS WILL
REMAIN VFR ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE NIGHT
AS SURFACE HIGH PRESSURE BUILDS IN. NORTHWEST WINDS TO EVENTUALLY
BECOME SOUTHWEST LATER ON THURSDAY AFTERNOON/EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ001-002-
009-010.
&&
$$
UPDATE...JV
SHORT TERM...TWH
LONG TERM...AYD
AVIATION...JV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1154 PM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 1154 PM CST WED NOV 20 2013
MADE SOME FURTHER ADJUSTMENTS TO POPS TO ALIGN WITH THE EASTWARD
PROGRESSION OF THE MAIN SNOW BAND. ADDED IN A PATCHY FREEZING
DRIZZLE MENTION DURING THE NEXT FEW HOURS FOR OUR SOUTH AND EAST
AS WE HAVE HAD SOME REPORTS FROM KFAR AND KBDE. HOWEVER...THE
FZDZ WILL NOT LAST LONG AS MODEL SOUNDINGS HAVE THE COLUMN
SATURATING FAIRLY QUICKLY AFTER 06Z. KEPT SNOW AMOUNTS CLOSE TO
WHAT WE HAD GOING WITH ONLY MINOR TWEAKS.
UPDATE ISSUED AT 927 PM CST WED NOV 20 2013
MAIN ADJUSTMENT WAS TO PUT OUT A QUICK WINTER WX ADVISORY FOR OUR
NORTHWESTERN CWA AND FAR NORTHERN VALLEY COUNTIES AS WE HAVE HAD
REPORTS OF NEARLY 5 INCHES AT STARKWEATHER AND AROUND 4 AT MADDOCK
AND SNOW CONTINUES. PUTTING THE ROEBBER METHOD SNOW RATIO
CALCULATIONS FOR BOTH THE GFS AND NAM PUTS OUR NORTHWESTERN CWA
INTO AN OVER 20 TO 1 RATIO...WHICH MAY EXPLAIN THE HIGHER AMOUNTS
THAN EXPECTED. THE SNOW BAND WILL CONTINUE TO SLOWLY TRANSITION
EASTWARD AS THE 700MB FRONTOGENESIS BAND MOVES FURTHER INTO THE
NORTHERN RED RIVER VALLEY. THE STRENGTH OF THE FRONTOGENESIS BAND
IS EXPECTED TO DIMINISH AS IT MOVES EAST SO THINK THAT THE AMOUNTS
FROM GFK AND FURTHER SOUTH AND EAST WILL BE LIGHTER THAT THOSE IN
THE DVL AREA. CUT POPS IN THE SOUTH AS NOT MUCH HAS BEEN REACHING
THE GROUND OVER SOUTH CENTRAL ND AND MODELS HAVE BEEN TRENDING
LIGHTER WITH ANY SNOW IN THE SOUTHERN VALLEY. ALSO SLOWED THE
MOVEMENT OF SNOW INTO NORTHWESTERN MN. COOLED TEMPS DOWN A BIT
MORE IN THE NORTHWESTERN COUNTIES AS SINGLE DIGITS JUST TO OUR
NORTH AND WEST EVEN WITH CLOUD COVER CONTINUES TO FILTER INTO THE
AREA.
UPDATE ISSUED AT 642 PM CST WED NOV 20 2013
ADJUSTED POPS FOR GOING RADAR TRENDS. CURRENT SNOW BAND OVER THE
DVL AREA WILL MOVE SOUTHEASTWARD TONIGHT...WITH MODELS SHOWING
SOME WEAKENING. THE WRF AND ONE HRRR RUN SHOW VERY LITTLE SNOW
MAKING IT TO OUR SOUTHERN COUNTIES. THE 18Z NAM AND LATEST HRRR
RUN HOWEVER HAVE A NARROW BAND MOVING THROUGH LATE THIS EVENING.
CUT POPS IN THE SOUTH A BIT...BUT DID NOT REMOVE THEM COMPLETELY.
STILL THINK THAT THE 1 TO 3 INCHES NORTH OF HIGHWAY 200 WITH
HIGHEST AMOUNTS NEAR DVL SEEMS REASONABLE...SO WILL MAINTAIN SNOW
AMOUNTS. TEMPS HAVE BEEN FALLING IN THE NORTHWEST A BIT FASTER
THAN EXPECTED...AND THAT AREA HAS THE BEST CHANCE OF SEEING SOME
CLEARING TOWARDS MORNING. THUS...CUT LOWS A FEW DEGREES DOWN
FURTHER INTO THE SINGLE DIGITS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 339 PM CST WED NOV 20 2013
THE MAIN FORECAST CHALLENGES THIS AFTERNOON INCLUDE LIGHT SNOW
EVENT LATE TODAY AND TONIGHT...AND TEMPS THE NEXT SEVERAL DAYS.
THE COLD FRONT HAS PROGRESSED LITTLE OVER THE PAST FEW
HOURS...ALLOWING TEMPS INTO WC MN TO WARM NICELY...WITH KOTT SITTING
AT 49 DEGREES AS OF 21Z. AS AN UPPER SHORTWAVE TROUGH CONTINUES TO
PROPAGATE EASTWARD ACROSS SOUTHERN CANADA AND THE STRONGER COLD
SURGE ACCELERATES SOUTHEASTWARD...COLDER AIR WILL FILTER INTO THE
SOUTHEAST COUNTIES OVERNIGHT.
THE INITIAL BAND OF LIGHT SNOW THAT MOVED FROM PARTS OF THE DEVILS
LAKE BASIN INTO THE NORTHERN VALLEY HAS NOT BEEN HANDLED VERY WELL
BY THE MODELS...BUT HAS PUT DOWN SOME LIGHT SNOW ACCUMULATIONS FROM
THE DEVILS LAKE AREA EAST NORTHEASTWARD.
ATTENTION REMAINS FOCUSED ON AN AREA OF SNOW ACROSS NW AND NC ND
FORCED BY MID-LEVEL FRONTOGENESIS. SEVERAL RECENT OBS ACROSS NW ND
HAVE INDICATED +SN. 12Z RUNS OF THE NAM/ECMWF/GFS ALL BRING THE
BRUNT OF THIS BAND ACROSS THE DEVILS LAKE BASIN INTO THE NORTHERN
VALLEY...AND THIS MATCHES WELL WITH OBSERVED TRENDS. THUS AT THIS
POINT...IT STILL APPEARS THAT 1 TO 3 INCHES OF ACCUMULATION IS ON
TRACK FOR THESE AREAS....ALTHOUGH A FEW ISOLATED HIGHER AMOUNTS
CANNOT BE RULED OUT. MODELS DO SHOW A WEAKENING TREND OF THE
FRONTOGENETICAL BAND OVERNIGHT...SO CURRENT THINKING IS THAT
TOTALS WILL REMAIN MOSTLY BELOW ADVISORY THRESHOLDS.
HOWEVER...THE EXACT LOCATION OF THE BAND AND ITS INTENSITY WILL
NEED TO BE MONITORED OVERNIGHT. FARTHER SOUTHEAST...GENERALLY ONLY
VERY LIGHT ACCUMULATIONS ARE EXPECTED. WINDS WILL REMAIN IN THE 15
TO 20 MPH RANGE OVERNIGHT...WITH SOME HIGHER GUSTS. HAVE NOT
MENTIONED ANY BLOWING SNOW...BUT THIS WILL BE SOMETHING TO WATCH
AS WELL.
AS HIGH PRESSURE AREA BUILDS INTO WESTERN ND BY LATE
TONIGHT...THE COLUMN BEGINS TO DRY OUT...SO SOME CLEARING IS
POSSIBLE LATE TONIGHT OVER THE DEVILS LAKE REGION. THIS MAY AFFECT
HOW LOW TEMPS FALL IN THIS AREA. OTHERWISE...CLOUDS WILL PERSIST
OVER MOST OF THE AREA TONIGHT. DESPITE PERSISTENT LOW-LEVEL COLD
ADVECTION...TEMPS SHOULD STAY MAINLY IN THE TEENS ACROSS THE
SOUTHEAST HALF OF THE AREA OVERNIGHT. .
FOR THURSDAY...THERE COULD BE A BIT OF LINGERING LIGHT SNOW EAST OF
THE VALLEY...WITH SFC HIGH PRESSURE AND CONTINUED COLD ADVECTION
LIMITING THE TEMP RISE...EVEN WITH SOME SUNSHINE...ESPECIALLY ACROSS
THE NORTH. TOMORROW NIGHT...WARM ADVECTION DEVELOPS AHEAD OF AN
UPPER SHORTWAVE TROUGH DIVING SOUTHEASTWARD FROM CANADA ON THE
PERIPHERY OF AN AMPLIFYING RIDGE ACROSS THE WESTERN CONUS. A MAJOR
QUESTION WILL BE HOW FAR TEMPS CAN FALL WITH DEVELOPING WARM
ADVECTION GIVEN SOME NEW SNOW ON THE GROUND IN PLACES. AT THIS
POINT KEPT LOWS MAINLY IN THE SINGLE DIGITS TO LOW TEENS. THE 12Z
GFS/ECMWF/NAM ALL KEEP ANY PRECIP FROM SYSTEM TO THE SOUTH OUT OF
THE AREA. AS A RESULT...MOST AREAS SHOULD REMAIN DRY THURSDAY
NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 339 PM CST WED NOV 20 2013
THE NEXT WAVE DROPS ACROSS THE REGION ON FRIDAY...WITH A REINFORCING
COLD FRONT MOVING SOUTHWARD DURING THE DAY. SOME LIGHT SNOW MAY
ACCOMPANY THE SYSTEM WITH SOME Q-VECTOR CONVERGENCE IN THE
700-300MB LAYER AND A 300 MB JET STREAK NOSING INTO THE DAKOTAS.
A STRONG 1049 MB ARCTIC HIGH WILL BUILD SOUTHWARD FRIDAY NIGHT INTO
SATURDAY...CENTERED OVER CENTRAL OR WESTERN ND SATURDAY MORNING.
BEHIND THE FRONT...925 MB TEMPS WILL FALL TO AROUND -16 TO
-20C...HIGHEST TO THE NORTH. TEMPS FRIDAY NIGHT SHOULD BE DOWN INTO
AT LEAST THE SINGLE DIGITS...WITH THE BEST LIKELIHOOD FOR SUBZERO
READINGS ACROSS NORTHWESTERN AREAS...WHERE SOME SNOWCOVER MAY EXIST
AND WINDS WILL BE LIGHTEST. TEMPS ON SATURDAY WILL LIKELY REMAIN
WELL BELOW NORMAL IN THE SINGLE DIGITS AND TEENS...WITH WEAK MIXING
UNDER THE SFC HIGH.
500 MB PATTERN BECOMES A BIT MORE WEST-NORTHWEST AS TROUGH AND COLD
AIRMASS MOVE EAST SUNDAY AND MONDAY. THUS LOOK FOR TEMPS TO
MODERATE QUICKLY SUN-MON BACK TO NEAR NORMAL VALUES. A FAST MOVING
SFC LOW WILL MOVE THRU CNTRL MANITOBA INTO WRN ONTARIO TO LAKE
SUPERIOR SUNDAY-MON...SPREADING SOME LOW CHANCES FOR LIGHT SNOW INTO
LAKE OF THE WOODS REGION. A SHOT OF COLDER AIR FOLLOWS THIS SFC LOW
FOR MID WEEK AS HIGH PRESSURE DROPS SOUTH. OUTSIDE OF SOME LOW
CHANCES FOR LIGHT SNOW IN LAKE OF THE WOODS AREA...DRY FCST FOR
SUNDAY INTO NEXT WEDENSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM CST WED NOV 20 2013
CIGS HAVE BEEN MOSTLY MVFR ALTHOUGH THERE HAS BEEN SOME IFR CIGS
AT KBJI. THE HEAVIER SNOW BAND OVER KGFK HAS DROPPING VIS TO
AROUND 1SM...ALTHOUGH KDVL HAS STARTED COMING BACK UP. ACCOUNTED
FOR THE EASTWARD MOVEMENT OF THE SNOW BAND AND INCLUDED SOME TEMPO
GROUPS FOR KGFK...KTVF...AND KBJI AS WELL AS KDVL FOR LINGERING
FLURRIES. DO NOT THINK THAT ANY VIS WILL GO DOWN TO BELOW A MILE
AS THERE HAS BEEN A WEAKENING TREND. SNOW SHOULD MOVE OUT OF THE
AREA AFTER 12Z...ALTHOUGH SOME MVFR CIGS WILL HANG AROUND A BIT
LONGER INTO THE MORNING. EVENTUALLY THE LOWER CLOUDS WILL CLEAR
OUT AND LEAVE SOME SCATTERED TO BROKEN CIRRUS. NORTH WINDS WITH
HIGH GUSTS OVERNIGHT WILL DIMINISH DURING THE DAY ON THURSDAY AND
EVENTUALLY BECOME LIGHT AND VARIBLE AND THEN SHIFT TO THE
SOUTHWEST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR NDZ006>008-
014>016-024-026-054.
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR MNZ004.
&&
$$
UPDATE...JR
SHORT TERM...MAKOWSKI
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1040 PM EST FRI NOV 22 2013
.SYNOPSIS...
COLD FRONT WILL EXIT EAST OF THE AREA THIS EVENING WITH A RIDGE
BUILDING IN FROM THE WEST. AN ARCTIC COLD FRONT WILL PUSH SOUTH
ACROSS THE AREA ON SATURDAY WITH LAKE EFFECT SNOW DEVELOPING. STRONG
HIGH PRESSURE WILL BUILD EAST ACROSS THE OHIO VALLEY LATE SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATE...CHANGED THE WATCH TO A LAKE EFFECT SNOW WARNING FOR
ASHTABULA...ERIE...AND CRAWFORD COUNTY. ALSO EXPANDED THE WATCH
TO INCLUDE LAKE COUNTY IN ADDITION TO GEAUGA. STILL A BIT OF A
QUESTION IF WARNING AMOUNTS WILL BE REACHED IN LAKE AND GEAUGA
GIVEN THE SHORT FETCH AND BUILDING HIGH PRESSURE ALTHOUGH DO
BELIEVE THERE IS A POSSIBILITY GIVEN LIFT FROM TERRAIN...EXTREME
INSTABILITY AND DEEP MIXING EXPECTED. FURTHER EAST THERE IS A GOOD
CHANCE OF HAVING A CONNECTION TO LAKE HURON. WITH MANY OTHER
POSITIVE FACTORS...DECIDED TO UPGRADE. GUSTY WINDS WILL ALSO
PRESENT A PROBLEM WHERE SNOWFALL IS HEAVIEST...CAUSING BLOWING AND
DRIFTING. OTHERWISE CLEARING ON TRACK FOR AREA OVERNIGHT SO WILL
CONTINUE WITH TREND OVERNIGHT.
ORIGINAL...AREA RADARS CONTINUE TO SHOW A LIGHT DRIZZLE ACROSS NE
OHIO/NW PA LATE THIS AFTERNOON. WILL CARRY DRIZZLE IN THE FORECAST
FOR A FEW HOURS WITH CONDITIONS DRYING OUT BEHIND THE COLD FRONT
THIS EVENING.
SURFACE ANALYSIS SHOWS ONE AREA OF LOW PRESSURE OVER QUEBEC WITH A
SECONDARY LOW DEVELOPING DEVELOPING NORTH OF LAKE SUPERIOR. THE FIRST
LOW WILL EXIT TO THE NORTHEAST TONIGHT WITH A RIDGE SHARPLY BUILDING
INTO THE LOW LEVELS IN ADVANCE OF THE SECOND SYSTEM. SATELLITE
IMAGERY SHOWS THE CLEARING LINE MOVING ACROSS WESTERN LOWER MICHIGAN
AND WILL PUSH INTO NW OHIO DURING THE EVENING. SKIES WILL CLEAR
EXCEPT FOR NE OH/NW PA WHERE ENHANCED TROUGHING DOWNWIND OF THE LAKE
WILL AID LAKE EFFECT CLOUD DEVELOPMENT. TEMPERATURES WILL FALL INTO
THE UPPER 20S FOR INLAND AREAS...HOLDING NEAR 30 ALONG THE LAKE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
UPPER LEVEL TROUGH SEEN ON WATER VAPOR IMAGERY OVER CANADA WILL
SURGE SOUTH OVER THE GREAT LAKES REGION ON SATURDAY...PUSHING AN
ARCTIC COLD FRONT SOUTH ACROSS THE AREA. THE 850MB TEMPERATURE AT
CHURCHILL MANITOBA WAS DOWN TO -24C THIS MORNING AND MODELS ARE IN
AGREEMENT THAT THE H850 TEMPERATURE WILL DROP TO NEAR -18C BY SUNDAY
MORNING. THE INITIAL FRONTAL PASSAGE WILL LACK MOISTURE AND WILL
JUST CARRY CHANCE POPS FOR MOST AREAS EXCEPT DOWNWIND OF LAKE ERIE.
THOSE AREAS WILL SEE A QUICK BURST OF SNOW WITH THE FRONT AND COULD
RESULT IN UP TO AN INCH OF SNOW ACCUMULATION OVER THE HIGHER
TERRAIN.
A BREAK IS EXPECTED BEFORE THE LAKE EFFECT SNOW RAMPS UP DURING THE
EVENING AS THE MOISTURE DEPTH INCREASES WITH THE PASSAGE OF THE
UPPER LEVEL TROUGH. THE COMBINATION OF EXTREME INSTABILITY OVER THE
LAKE AND UPSLOPE NORTHWESTERLY FLOW WILL ALLOW LAKE EFFECT SNOW
SHOWERS TO FILL IN ACROSS THE SNOW BELT. THE HEAVIEST ACCUMULATIONS
ARE EXPECTED IN NW PA WHERE MODELS INDICATE WE WILL ESTABLISH A LAKE
HURON CONNECTION. SNOWFALL RATES BENEATH THIS BAND COULD BE 2 INCHES
PER HOUR BUT HARD TO DEFINE EXACTLY WHERE THIS BAND WILL SET. IT
LOOKS LIKE FAIRLY HIGH CHANCES OF IT IMPACTING ERIE AND CRAWFORD PA.
THE AIRMASS IS COLD ENOUGH THAT NOT EXPECTING THE LAKE TO REDUCE
ACCUMULATIONS ENOUGH TO LEAVE THE LAKESHORE AREAS OUT.
ACCUMULATIONS IN NW PA WILL EXCEED 6 INCHES IN MANY AREAS BUT
LOCAL AMOUNTS COULD EXCEED A FOOT BY THE TIME THE SNOW ENDS IF THE
BAND BECOMES STATIONARY.
HAVE EXPANDED THE LES WATCH TO INCLUDE GEAUGA COUNTY WHERE THE
UPSLOPE COMPONENT WILL CAUSE ENOUGH ENHANCEMENT FOR ACCUMULATIONS OF
4 TO 8 INCHES. THE BULK OF THIS WILL FALL ON SATURDAY NIGHT WITH THE
PASSAGE OF THE UPPER LEVEL TROUGH. THE REST OF THE SNOW BELT WILL
SEE ACCUMULATING SNOW AND LAKE EFFECT SNOW ADVISORIES MAY BE NEEDED
IN PERIPHERY COUNTIES. NORTHWEST WINDS WILL CONTRIBUTE TO BLUSTERY
CONDITIONS WITH SPEEDS OF 15 TO 25 MPH AND GUSTS TO 35 MPH. THE SNOW
WILL HAVE A HIGH SNOW/LIQUID RATIO (15:1 OR EVEN 18:1) GIVEN THE
COLD AIRMASS AND WILL BLOW AROUND EASILY.
STRONG HIGH PRESSURE OVER THE MIDWEST WILL EXPAND OVER THE OHIO
VALLEY ON SUNDAY AND WILL BE ACCOMPANIED BY VERY DRY AIR. DEWPOINTS
FALL INTO THE SINGLE DIGITS AND TEENS AND SNOW WILL DECREASE IN
COVERAGE FROM WEST TO EAST AS THIS DRY AIR INTRUDES. THE
COMPLICATING FACTOR OF THIS FORECAST IS HOW LONG IT WILL TAKE FOR
SNOW TO DECREASE...GIVEN THE LIMITED MOISTURE WITH THE SYSTEM.
DECIDED TO LET THE WATCHES CONTINUE FOR ANOTHER FORECAST PACKAGE TO
ALLOW ADDITIONAL TIME TO CONSIDER THE MOISTURE QUALITY AND PLACEMENT
OF LAKE EFFECT SNOW BANDS BEFORE MAKING DETERMINATION ON
WARNINGS/ADVISORIES. HEAVY SNOW ALSO NOT EXPECTED TO DEVELOP UNTIL
SATURDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
VERY FEW CHANGES TO THE LONG TERM TODAY AS THE PERIOD LOOKS COLD
WITH OCCASIONAL SNOW SHOWERS. WILL TRY TO START THE PERIOD OFF DRY
ON MONDAY. A SYSTEM WILL PASS TO THE NORTH ON TUESDAY AND DRAG A
COLD FRONT ACROSS THE REGION. SOME WARM AIR ADVECTION PRECIP COULD
OCCUR AS EARLY AS MONDAY NIGHT BUT BETTER CHANCES FOR MEASURABLE
PRECIP WILL COME WITH THE FRONT. WINDS WILL BECOME FAVORABLE FOR
LAKE EFFECT SNOW LATE TUESDAY THROUGH WEDNESDAY NIGHT. MOISTURE
APPEARS TO BE SOMEWHAT LIMITED AS IT WILL BE A DRY AIRMASS. AS A
RESULT...NO MORE THAN CHANCE POPS FOR THE TIME BEING. THE SURFACE
RIDGE WILL MOVE JUST TO EAST OF THE AREA ON THURSDAY AND THEN LINGER
ON FRIDAY. THIS WILL PREVENT AN AIRMASS CHANGE. HIGH TEMPS THE
ENTIRE WEEK WILL BE A GOOD 10 TO 15 DEGREES BELOW NORMAL.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
DIFFICULT FORECAST FOR THE OVERNIGHT HOURS. SIGNIFICANT
DRYING...AT LEAST AT MID LEVELS WILL BE COMING IN OVERNIGHT.
EVENING NW GUSTS WILL SUBSIDE SOME AND THE WINDS WILL BACK MORE
WESTERLY AS TEMPORARY RIDGING NUDGES TOWARD THE AREA. QUESTIONS
WILL BE WHAT WILL HAPPEN WITH THE CURRENT IFR/MVFR CEILINGS. MOST
MODEL GUIDANCE WANTS TO CLEAR OR SCATTER THAT OUT LEAVING VFR
CONDITIONS FOR MORNING. ONE MODEL...THE HRRR WOULD LIKE TO
REDEVELOP AT LEAST AN MVFR CEILING ACROSS THE WEST AFTER 09Z AND
NEVER REALLY GET RID OF A NON-VFR CEILING ACROSS THE EAST. HAVE
TRENDED THE FORECAST IN THIS MORE PESSIMISTIC DIRECTION. MODELS
HAVE BEEN TOO FAST ALL DAY...AND OUR CURRENT CEILING SITUATION HAS
HUNG ON LONGER THAN IT WAS SUPPOSE TO.
FOR SATURDAY...NEXT TROUGH WILL DROP SOUTH ACROSS THE AREA FOR THE
AFTERNOON HOURS. SOME SCATTERED SNOW ACTIVITY POSSIBLE WITH
THIS...THE SNOW SHOWERS LIKELY FOR THE SNOWBELT. THIS WILL RETURN
CONDITIONS TO MVFR OR LOWER. WINDS WILL ALSO BE GUSTY
SATURDAY...WITH 25 KNOTS FOR MOST...30 KNOTS FOR SOME. FOR THE
EXTENDED PORTION OF THE CLE TAF...WINDS WILL REMAIN GUSTY EVEN
AFTER 00Z SUN.
OUTLOOK...NON VFR MAINLY OVER NE OH AND NW PA SATURDAY NIGHT THROUGH
SUNDAY BECAUSE OF LAKE EFFECT. NON VFR RETURNING LATE MONDAY NIGHT
INTO TUESDAY AND CONTINUING ACROSS NE OH/NW PA ON WEDNESDAY.
&&
.MARINE...
WITH THE EXCEPTION OF A FEW HOURS LATER TONIGHT WILL LIKELY SEE
SMALL CRAFT CONDITIONS THE ENTIRE PERIOD. NW FLOW WILL CONTINUE
TONIGHT THROUGH SUNDAY. SPEEDS WILL INCREASE LATE SATURDAY AS A
SECONDARY COLD FRONT CROSSES THE LAKE. COULD GET SUSTAINED WINDS IN
THE 25 TO 30 KNOT RANGE FOR SEVERAL HOURS BEHIND THE FRONT. WINDS
WILL BECOME SW ON MONDAY AS SURFACE RIDGE CROSSES THE LAKE. SPEEDS
WILL REMAIN UP WITH SUSTAINED WINDS OF AT LEAST 20 KNOTS. ANOTHER
COLD FRONT WILL CROSS THE LAKE ON TUESDAY CAUSING THE FLOW TO RETURN
TO THE NW. STRONG NORTH TO NW FLOW WILL THEN CONTINUE THROUGH
WEDNESDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...LAKE EFFECT SNOW WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
EVENING FOR OHZ012-013.
LAKE EFFECT SNOW WARNING FROM NOON SATURDAY TO MIDNIGHT EST
SUNDAY NIGHT FOR OHZ014-089.
PA...LAKE EFFECT SNOW WARNING FROM NOON SATURDAY TO MIDNIGHT EST
SUNDAY NIGHT FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/TK
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...OUDEMAN
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
648 PM EST FRI NOV 22 2013
.SYNOPSIS...
COLD FRONT WILL EXIT EAST OF THE AREA THIS EVENING WITH A RIDGE
BUILDING IN FROM THE WEST. AN ARCTIC COLD FRONT WILL PUSH SOUTH
ACROSS THE AREA ON SATURDAY WITH LAKE EFFECT SNOW DEVELOPING. STRONG
HIGH PRESSURE WILL BUILD EAST ACROSS THE OHIO VALLEY LATE SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATE...FORECAST ON TRACK. NO SIGNIFICANT CHANGES.
ORIGINAL...AREA RADARS CONTINUE TO SHOW A LIGHT DRIZZLE ACROSS NE
OHIO/NW PA LATE THIS AFTERNOON. WILL CARRY DRIZZLE IN THE FORECAST
FOR A FEW HOURS WITH CONDITIONS DRYING OUT BEHIND THE COLD FRONT
THIS EVENING.
SUFACE ANALYSIS SHOWS ONE AREA OF LOW PRESSURE OVER QUEBEC WITH A
SEONDARY LOW DEVELOPING DEVELOPING NORTH OF LAKE SUPERIOR. THE FIRST
LOW WILL EXIT TO THE NORTHEAST TONIGHT WITH A RIDGE SHARPLY BUILDING
INTO THE LOW LEVELS IN ADVANCE OF THE SECOND SYSTEM. SATELLITE
IMAGERY SHOWS THE CLEARING LINE MOVING ACROSS WESTERN LOWER MICHIGAN
AND WILL PUSH INTO NW OHIO DURING THE EVENING. SKIES WILL CLEAR
EXCEPT FOR NE OH/NW PA WHERE ENHANCED TROUGHING DOWNWIND OF THE LAKE
WILL AID LAKE EFFECT CLOUD DEVELOPEMENT. TEMPERATURES WILL FALL INTO
THE UPPER 20S FOR INLAND AREAS...HOLDING NEAR 30 ALONG THE LAKE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
UPPER LEVEL TROUGH SEEN ON WATER VAPOR IMAGERY OVER CANADA WILL
SURGE SOUTH OVER THE GREAT LAKES REGION ON SATURDAY...PUSHING AN
ARCTIC COLD FRONT SOUTH ACROSS THE AREA. THE 850MB TEMPERATURE AT
CHURCHILL MANITOBA WAS DOWN TO -24C THIS MORNING AND MODELS ARE IN
AGREEMENT THAT THE H850 TEMPERATURE WILL DROP TO NEAR -18C BY SUNDAY
MORNING. THE INITIAL FRONTAL PASSAGE WILL LACK MOISTURE AND WILL
JUST CARRY CHANCE POPS FOR MOST AREAS EXCEPT DOWNWIND OF LAKE ERIE.
THOSE AREAS WILL SEE A QUICK BURST OF SNOW WITH THE FRONT AND COULD
RESULT IN UP TO AN INCH OF SNOW ACCUMULATION OVER THE HIGHER
TERRAIN.
A BREAK IS EXPECTED BEFORE THE LAKE EFFECT SNOW RAMPS UP DURING THE
EVENING AS THE MOISTURE DEPTH INCREASES WITH THE PASSAGE OF THE
UPPER LEVEL TROUGH. THE COMBINATION OF EXTREME INSTABILITY OVER THE
LAKE AND UPSLOPE NORTHWESTERLY FLOW WILL ALLOW LAKE EFFECT SNOW
SHOWERS TO FILL IN ACROSS THE SNOW BELT. THE HEAVIEST ACCUMULATIONS
ARE EXPECTED IN NW PA WHERE MODELS INDICATE WE WILL ESTABLISH A LAKE
HURON CONNECTION. SNOWFALL RATES BENEATH THIS BAND COULD BE 2 INCHES
PER HOUR BUT HARD TO DEFINE EXACTLY WHERE THIS BAND WILL SET. IT
LOOKS LIKE FAIRLY HIGH CHANCES OF IT IMPACTING ERIE AND CRAWFORD PA.
THE AIRMASS IS COLD ENOUGH THAT NOT EXPECTING THE LAKE TO REDUCE
ACCUMULATIONS ENOUGH TO LEAVE THE LAKESHORE AREAS OUT.
ACCUMULATIONS IN NW PA WILL EXCEED 6 INCHES IN MANY AREAS BUT
LOCAL AMOUNTS COULD EXCEED A FOOT BY THE TIME THE SNOW ENDS IF THE
BAND BECOMES STATIONARY.
HAVE EXPANDED THE LES WATCH TO INCLUDE GEAUGA COUNTY WHERE THE
UPSLOPE COMPONENT WILL CAUSE ENOUGH ENHANCEMENT FOR ACCUMULATIONS OF
4 TO 8 INCHES. THE BULK OF THIS WILL FALL ON SATURDAY NIGHT WITH THE
PASSAGE OF THE UPPER LEVEL TROUGH. THE REST OF THE SNOW BELT WILL
SEE ACCUMULATING SNOW AND LAKE EFFECT SNOW ADVISORIES MAY BE NEEDED
IN PERIPHERY COUNTIES. NORTHWEST WINDS WILL CONTRIBUTE TO BLUSTERLY
CONDITIONS WITH SPEEDS OF 15 TO 25 MPH AND GUSTS TO 35 MPH. THE SNOW
WILL HAVE A HIGH SNOW/LIQUID RATIO (15:1 OR EVEN 18:1) GIVEN THE
COLD AIRMASS AND WILL BLOW AROUND EASILY.
STRONG HIGH PRESSURE OVER THE MIDWEST WILL EXPAND OVER THE OHIO
VALLEY ON SUNDAY AND WILL BE ACCOMPANIED BY VERY DRY AIR. DEWPOINTS
FALL INTO THE SINGLE DIGITS AND TEENS AND SNOW WILL DECREASE IN
COVERAGE FROM WEST TO EAST AS THIS DRY AIR INTRUDES. THE
COMPLICATING FACTOR OF THIS FORECAST IS HOW LONG IT WILL TAKE FOR
SNOW TO DECREASE...GIVEN THE LIMITED MOISTURE WITH THE SYSTEM.
DECIDED TO LET THE WATCHES CONTINUE FOR ANOTHER FORECAST PACKAGE TO
ALLOW ADDITIONAL TIME TO CONSIDER THE MOISTURE QUALITY AND PLACEMENT
OF LAKE EFFECT SNOW BANDS BEFORE MAKING DETERMINATION ON
WARNINGS/ADVISORIES. HEAVY SNOW ALSO NOT EXPECTED TO DEVELOP UNTIL
SATURDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
VERY FEW CHANGES TO THE LONG TERM TODAY AS THE PERIOD LOOKS COLD
WITH OCCASIONAL SNOW SHOWERS. WILL TRY TO START THE PERIOD OFF DRY
ON MONDAY. A SYSTEM WILL PASS TO THE NORTH ON TUESDAY AND DRAG A
COLD FRONT ACROSS THE REGION. SOME WARM AIR ADVECTION PRECIP COULD
OCCUR AS EARLY AS MONDAY NIGHT BUT BETTER CHANCES FOR MEASURABLE
PRECIP WILL COME WITH THE FRONT. WINDS WILL BECOME FAVORABLE FOR
LAKE EFFECT SNOW LATE TUESDAY THROUGH WEDNESDAY NIGHT. MOISTURE
APPEARS TO BE SOMEWHAT LIMITED AS IT WILL BE A DRY AIRMASS. AS A
RESULT...NO MORE THAN CHANCE POPS FOR THE TIME BEING. THE SURFACE
RIDGE WILL MOVE JUST TO EAST OF THE AREA ON THURSDAY AND THEN LINGER
ON FRIDAY. THIS WILL PREVENT AN AIRMASS CHANGE. HIGH TEMPS THE
ENTIRE WEEK WILL BE A GOOD 10 TO 15 DEGREES BELOW NORMAL.
&&
.AVIATION /23Z SATURDAY THROUGH WEDNESDAY/...
DIFFICULT FORECAST FOR THE OVERNIGHT HOURS. SIGNIFICANT
DRYING...AT LEAST AT MIDLEVELS WILL BE COMING IN OVERNIGHT.
EVENING NW GUSTS WILL SUBSIDE SOME AND THE WINDS WILL BACK MORE
WESTERLY AS TEMPORARY RIDGING NUDGES TOWARD THE AREA. QUESTIONS
WILL BE WHAT WILL HAPPEN WITH THE CURRENT IFR/MVFR CEILINGS. MOST
MODEL GUIDANCE WANTS TO CLEAR OR SCATTER THAT OUT LEAVING VFR
CONDITIONS FOR MORNING. ONE MODEL...THE HRRR WOULD LIKE TO
REDEVELOP AT LEAST AN MVFR CEILING ACROSS THE WEST AFTER 09Z AND
NEVER REALLY GET RID OF A NON-VFR CEILING ACROSS THE EAST. HAVE
TRENDED THE FORECAST IN THIS MORE PESSIMISTIC DIRECTION. MODELS
HAVE BEEN TOO FAST ALL DAY...AND OUR CURRENT CEILING SITUATION HAS
HUNG ON LONGER THAN IT WAS SUPPOSE TO.
FOR SATURDAY...NEXT TROUGH WILL DROP SOUTH ACROSS THE AREA FOR THE
AFTERNOON HOURS. SOME SCATTERED SNOW ACTIVITY POSSIBLE WITH
THIS...THE SNOW SHOWERS LIKELY FOR THE SNOWBELT. THIS WILL RETURN
CONDITIONS TO MVFR OR LOWER. WINDS WILL ALSO BE GUSTY
SATURDAY...WITH 25 KNOTS FOR MOST...30 KNOTS FOR SOME. FOR THE
EXTENDED PORTION OF THE CLE TAF...WINDS WILL REMAIN GUSTY EVEN
AFTER 00Z SUN.
OUTLOOK...NON VFR MAINLY OVER NE OH AND NW PA SATURDAY NIGHT THROUGH
SUNDAY BECAUSE OF LAKE EFFECT. NON VFR RETURNING LATE MONDAY NIGHT
INTO TUESDAY AND CONTINUING ACROSS NE OH/NW PA ON WEDNESDAY.
&&
.MARINE...
WITH THE EXCEPTION OF A FEW HOURS LATER TONIGHT WILL LIKELY SEE
SMALL CRAFT CONDITIONS THE ENTIRE PERIOD. NW FLOW WILL CONTINUE
TONIGHT THROUGH SUNDAY. SPEEDS WILL INCREASE LATE SATURDAY AS A
SECONDARY COLD FRONT CROSSES THE LAKE. COULD GET SUSTAINED WINDS IN
THE 25 TO 30 KNOT RANGE FOR SEVERAL HOURS BEHIND THE FRONT. WINDS
WILL BECOME SW ON MONDAY AS SURFACE RIDGE CROSSES THE LAKE. SPEEDS
WILL REMAIN UP WITH SUSTAINED WINDS OF AT LEAST 20 KNOTS. ANOTHER
COLD FRONT WILL CROSS THE LAKE ON TUESDAY CAUSING THE FLOW TO RETURN
TO THE NW. STRONG NORTH TO NW FLOW WILL THEN CONTINUE THROUGH
WEDNESDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...LAKE EFFECT SNOW WATCH FROM SATURDAY EVENING THROUGH SUNDAY
EVENING FOR OHZ013-014-089.
PA...LAKE EFFECT SNOW WATCH FROM SATURDAY EVENING THROUGH SUNDAY
EVENING FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/TK
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...OUDEMAN
MARINE...KUBINA
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
927 PM CST FRI NOV 22 2013
.UPDATE...
PRECIP CONTINUES TO GRADUALLY SHIFT TO THE EAST THIS EVENING. THIS
TREND WILL CONTINUE OVERNIGHT/EARLY SATURDAY. FREEZING
RAIN/FREEZING DRIZZLE WILL CONT TO BE PRIMARY PRECIP EXCEPT IN FAR
SE PART OF FA WHERE TEMPS ARE ABOVE FREEZING. PRECIP HAS ENDED FOR
THE MOST PART ACROSS NORTHERN AND PARTS OF WESTERN OK SO PART OF
THE WINTER WX ADVISORY WAS CANCELED. HOWEVER... A FEW SNOW
FLURRIES COULD OCCUR IN THIS AREA OVERNIGHT AND SOME ROADS MAY
STILL HAVE SLICK SPOTS FROM THE EARLIER PRECIP. UPDATES WILL BE
OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 549 PM CST FRI NOV 22 2013/
AVIATION...
23/00Z TAFS...TEMPO/PREVAILING -FZDZ/-FZRA WILL CONTINUE FIRST 2
TO 4 HOURS OF TERMINALS FCST NEAR AND SOUTH OF INTERSTATE-40.
PRIMARILY MVFR/VFR CONDITIONS THROUGH TONIGHT WITH VFR TOMORROW.
STRONG NORTHERLY WIND WILL CONTINUE EXCEPT FAR NORTHWEST
TERMINALS...WITH THOSE SITES INCREASING AGAIN TOMORROW WITH
REINFORCING CANADIAN AIRMASS.
PREV DISCUSSION... /ISSUED 300 PM CST FRI NOV 22 2013/
DISCUSSION...
TWO MAIN FORECAST CONCERNS TO COVER...-FZRA/SLEET TODAY AND
SNOW/SLEET CHANCES LATE SATURDAY THROUGH MONDAY.
CURRENTLY...ACTIVE WINTER WEATHER CONTINUES TO IMPACT MUCH OF
OKLAHOMA AND NRN TEXAS. FREEZING RAIN AND SLEET CONTINUE TO FALL
ACROSS PORTIONS OF WRN N TX AND THROUGH WRN AND CENTRAL OK THIS
AFTERNOON...THE IMPACTS OF WHICH HAVE PROMPTED A FEW TO SAY...WELL
THAT ESCALATED QUICKLY. WITH SFC TEMPS HOLDING AT OR NEAR
FREEZING...ROADS HAVE BECOME HAZARDOUS IN SOME PLACES ACROSS THE
REGION...WITH NUMEROUS TRAFFIC ACCIDENTS REPORTED VIA SOCIAL
MEDIA/LOCAL MEDIA/AND SPOTTERS. MOST ROADS REMAIN WET...NOT
FROZEN...WITH ELEVATED SURFACES...SUCH AS BRIDGES AND OVERPASSES THE
MOST LIKELY TO HAVE ICING. BEST ADVICE...SLOW DOWN. 18Z SPECIAL
RELEASE FROM OUN SHOWS A DECENT SLEET/FZRA SOUNDING...WITH BOTH
PRECIP TYPES FALLING AT VARIOUS TIMES AT THE OFFICE AND ACROSS THE
OKC METRO/REGION THROUGH THE PAST FEW HOURS. MOST IMPRESSIVE...THE
NEAR SFC FREEZING LAYER HAS REMAINED AS DEEP...-7 C AT BOTH 12 AND
18Z APPROXIMATELY 430M AGL. MESOSCALE MODELS...SUCH AS THE HRRR AND
RAP SEEM TO HAVE A DECENT HANDLE ON THE OVERALL PROGRESSION OF THE
SYSTEM. STARTING THIS MORNING...700MB WINDS BEGAN TO VEER BACK TO
THE SW...WITH GOOD WAA AND MOISTURE RETURN. WITH THE GOOD ISENTROPIC
RESPONSE...WELL VISUALIZED AT THE 305K LEVEL...ABOUT THE HEIGHT OF
THE 750-700MB LEVEL...FZRA AND SLEET WILL CONTINUE THROUGH THE
AFTN/EARLY EVENING HRS...SLOWLY SHIFTING S/SE THROUGH 00Z AS THE
ARCTIC HIGH CONTINUES TO PROTRUDE INTO NRN OK. AREAS OF -FZRA/-FZDZ
WILL LIKELY LINGER ACROSS CENTRAL OK THROUGH MIDNIGHT...WITH THE
REMAINDER OF ACTIVITY CONTINUING TO SHIFT SOUTHWARD THROUGH EARLY
SATURDAY MORNING...WITH AREAS OF -FZRA/-FZDZ/-RA NEAR/ALONG THE RED
RIVER VALLEY THROUGH SUNRISE.
SATURDAY DURING THE DAY SHOULD BE DRY...BUT COLD...WITH HIGHS ONLY
CLIMBING INTO THE MID/UPPER 30S...WITH WIND CHILLS IN THE TEENS AS
NORTH WINDS PERSIST. WINTER WEATHER WILL THEN MAKE A RETURN LATE
SATURDAY NIGHT AND CONTINUE THROUGH MONDAY. A DEEPENING UPPER
LOW...A BOWLING BALL IF YOU WILL...CONTINUES TO DIG DOWN THE WEST
COAST THIS AFTERNOON...WELL VISUALIZED ON WV IMAGERY. THIS
DEEPENING H500 TROUGH WILL CONTINUE TO DIG S/SE AND SWING EWRD
ACROSS THE DESERT SOUTHWEST. AS KG MENTIONED LAST NIGHT...THERE IS
NO APPARENT KICKER TO FORCE THIS FEATURE QUICKLY ACROSS THE SRN
PLAINS...SO ITS A RELATIVELY SLOW MOVING...BUT STRONG TROUGH.
GUIDANCE REMAINS IN DECENT AGREEMENT WITH THE TRANSITION OF THE
UPPER TROUGH...WITH A DECENT REGION OF ISENTROPIC LIFT DEVELOPING
ACROSS THE PANHANDLES AND FAR WRN OK SATURDAY NIGHT. GFS AND NAM
BUFR PROFILES TAKEN ACROSS THE REGION CONTINUE TO SHOW A SNOW/SLEET
MIX TO START...WITH A TRANSITION TO SNOW THROUGH SUNDAY...SPREADING
EASTWARD ACROSS THE REGION. GIVEN IT IS WINTER IN THE SRN
PLAINS...TIMING AND IMPACTS ARE LIKELY TO CHANGE BETWEEN NOW AND
THEN. HOWEVER...CONFIDENCE IS GROWING IN MUCH OF WRN N TX AND
CENTRAL AND WRN OK TO SEE THERE FIRST SNOW FLAKES OF THE YEAR. BEST
CHANCES WILL BE FROM WRN N TX THROUGH CENTRAL OK...WITH MOST
LOCATIONS SEEING A TRACE TO 2 INCHES...WITH SOME SEEING AS MUCH AS
3. OF COURSE...SOME LOCATIONS MAY SEE MORE SLEET THAN SNOW. LIGHT
SNOW/SLEET CHANCES WILL CONTINUE THROUGH MONDAY...WITH A TRANSITION
TO RAIN/SNOW MIX POSSIBLE...AND RAIN ACROSS SRN OK/NRN TX THROUGH
TUESDAY MORNING.
DRY...CALM WEATHER WILL THEN PERSIST FOR THE REMAINDER OF THE
HOLIDAY WEEK...WITH HIGHS WARMING BACK INTO THE LOWER 50S BY
THANKSGIVING DAY...CONTINUING THROUGH THE WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 27 38 26 32 / 80 10 20 50
HOBART OK 27 38 26 31 / 60 10 30 50
WICHITA FALLS TX 29 39 28 34 / 70 10 30 70
GAGE OK 22 34 21 30 / 10 0 30 50
PONCA CITY OK 27 37 20 34 / 10 0 10 30
DURANT OK 33 42 31 38 / 90 20 10 60
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR OKZ017>020-
022>047-050-051.
TX...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR TXZ083>090.
&&
$$
25/11
AREA FORECAST DISCUSSION
NWS NORMAN OK
549 PM CST FRI NOV 22 2013
.AVIATION...
23/00Z TAFS...TEMPO/PREVAILING -FZDZ/-FZRA WILL CONTINUE FIRST 2
TO 4 HOURS OF TERMINALS FCST NEAR AND SOUTH OF INTERSTATE-40.
PRIMARILY MVFR/VFR CONDITIONS THROUGH TONIGHT WITH VFR TOMORROW.
STRONG NORTHERLY WIND WILL CONTINUE EXCEPT FAR NORTHWEST
TERMINALS...WITH THOSE SITES INCREASING AGAIN TOMORROW WITH
REINFORCING CANADIAN AIRMASS.
&&
.PREV DISCUSSION... /ISSUED 300 PM CST FRI NOV 22 2013/
DISCUSSION...
TWO MAIN FORECAST CONCERNS TO COVER...-FZRA/SLEET TODAY AND
SNOW/SLEET CHANCES LATE SATURDAY THROUGH MONDAY.
CURRENTLY...ACTIVE WINTER WEATHER CONTINUES TO IMPACT MUCH OF
OKLAHOMA AND NRN TEXAS. FREEZING RAIN AND SLEET CONTINUE TO FALL
ACROSS PORTIONS OF WRN N TX AND THROUGH WRN AND CENTRAL OK THIS
AFTERNOON...THE IMPACTS OF WHICH HAVE PROMPTED A FEW TO SAY...WELL
THAT ESCALATED QUICKLY. WITH SFC TEMPS HOLDING AT OR NEAR
FREEZING...ROADS HAVE BECOME HAZARDOUS IN SOME PLACES ACROSS THE
REGION...WITH NUMEROUS TRAFFIC ACCIDENTS REPORTED VIA SOCIAL
MEDIA/LOCAL MEDIA/AND SPOTTERS. MOST ROADS REMAIN WET...NOT
FROZEN...WITH ELEVATED SURFACES...SUCH AS BRIDGES AND OVERPASSES THE
MOST LIKELY TO HAVE ICING. BEST ADVICE...SLOW DOWN. 18Z SPECIAL
RELEASE FROM OUN SHOWS A DECENT SLEET/FZRA SOUNDING...WITH BOTH
PRECIP TYPES FALLING AT VARIOUS TIMES AT THE OFFICE AND ACROSS THE
OKC METRO/REGION THROUGH THE PAST FEW HOURS. MOST IMPRESSIVE...THE
NEAR SFC FREEZING LAYER HAS REMAINED AS DEEP...-7 C AT BOTH 12 AND
18Z APPROXIMATELY 430M AGL. MESOSCALE MODELS...SUCH AS THE HRRR AND
RAP SEEM TO HAVE A DECENT HANDLE ON THE OVERALL PROGRESSION OF THE
SYSTEM. STARTING THIS MORNING...700MB WINDS BEGAN TO VEER BACK TO
THE SW...WITH GOOD WAA AND MOISTURE RETURN. WITH THE GOOD ISENTROPIC
RESPONSE...WELL VISUALIZED AT THE 305K LEVEL...ABOUT THE HEIGHT OF
THE 750-700MB LEVEL...FZRA AND SLEET WILL CONTINUE THROUGH THE
AFTN/EARLY EVENING HRS...SLOWLY SHIFTING S/SE THROUGH 00Z AS THE
ARCTIC HIGH CONTINUES TO PROTRUDE INTO NRN OK. AREAS OF -FZRA/-FZDZ
WILL LIKELY LINGER ACROSS CENTRAL OK THROUGH MIDNIGHT...WITH THE
REMAINDER OF ACTIVITY CONTINUING TO SHIFT SOUTHWARD THROUGH EARLY
SATURDAY MORNING...WITH AREAS OF -FZRA/-FZDZ/-RA NEAR/ALONG THE RED
RIVER VALLEY THROUGH SUNRISE.
SATURDAY DURING THE DAY SHOULD BE DRY...BUT COLD...WITH HIGHS ONLY
CLIMBING INTO THE MID/UPPER 30S...WITH WIND CHILLS IN THE TEENS AS
NORTH WINDS PERSIST. WINTER WEATHER WILL THEN MAKE A RETURN LATE
SATURDAY NIGHT AND CONTINUE THROUGH MONDAY. A DEEPENING UPPER
LOW...A BOWLING BALL IF YOU WILL...CONTINUES TO DIG DOWN THE WEST
COAST THIS AFTERNOON...WELL VISUALIZED ON WV IMAGERY. THIS
DEEPENING H500 TROUGH WILL CONTINUE TO DIG S/SE AND SWING EWRD
ACROSS THE DESERT SOUTHWEST. AS KG MENTIONED LAST NIGHT...THERE IS
NO APPARENT KICKER TO FORCE THIS FEATURE QUICKLY ACROSS THE SRN
PLAINS...SO ITS A RELATIVELY SLOW MOVING...BUT STRONG TROUGH.
GUIDANCE REMAINS IN DECENT AGREEMENT WITH THE TRANSITION OF THE
UPPER TROUGH...WITH A DECENT REGION OF ISENTROPIC LIFT DEVELOPING
ACROSS THE PANHANDLES AND FAR WRN OK SATURDAY NIGHT. GFS AND NAM
BUFR PROFILES TAKEN ACROSS THE REGION CONTINUE TO SHOW A SNOW/SLEET
MIX TO START...WITH A TRANSITION TO SNOW THROUGH SUNDAY...SPREADING
EASTWARD ACROSS THE REGION. GIVEN IT IS WINTER IN THE SRN
PLAINS...TIMING AND IMPACTS ARE LIKELY TO CHANGE BETWEEN NOW AND
THEN. HOWEVER...CONFIDENCE IS GROWING IN MUCH OF WRN N TX AND
CENTRAL AND WRN OK TO SEE THERE FIRST SNOW FLAKES OF THE YEAR. BEST
CHANCES WILL BE FROM WRN N TX THROUGH CENTRAL OK...WITH MOST
LOCATIONS SEEING A TRACE TO 2 INCHES...WITH SOME SEEING AS MUCH AS
3. OF COURSE...SOME LOCATIONS MAY SEE MORE SLEET THAN SNOW. LIGHT
SNOW/SLEET CHANCES WILL CONTINUE THROUGH MONDAY...WITH A TRANSITION
TO RAIN/SNOW MIX POSSIBLE...AND RAIN ACROSS SRN OK/NRN TX THROUGH
TUESDAY MORNING.
DRY...CALM WEATHER WILL THEN PERSIST FOR THE REMAINDER OF THE
HOLIDAY WEEK...WITH HIGHS WARMING BACK INTO THE LOWER 50S BY
THANKSGIVING DAY...CONTINUING THROUGH THE WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 29 38 26 32 / 100 10 20 50
HOBART OK 27 38 26 31 / 80 10 30 50
WICHITA FALLS TX 30 39 28 34 / 100 10 30 70
GAGE OK 21 34 21 30 / 10 0 30 50
PONCA CITY OK 28 37 20 34 / 10 0 10 30
DURANT OK 34 42 31 38 / 100 20 10 60
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR OKZ004>047-
050-051.
TX...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR TXZ083>090.
&&
$$
25/11
AREA FORECAST DISCUSSION
NWS NORMAN OK
1216 PM CST THU NOV 21 2013
.AVIATION...
STRONG COLD FRONT IS MOVING THROUGH THE AREA. BRISK NORTH WINDS
AND MVFR CONDITIONS WILL OCCUR BEHIND THE FRONT. PRECIPITATION IS
CHANCES ARE SOMEWHAT UNCERTAIN AS MODELS HAVE VERY DIFFERENT
SOLUTIONS WITH RESPECT TO PRECIPITATION DEVELOPMENT... ESPECIALLY
NORTHWEST. BUT PRECIPITATION THAT OCCURS WILL MAINLY BE IN THE
FORM OF RAIN WHERE SURFACE TEMPERATURES ARE ABOVE FREEZING... AND
FREEZING RAIN WHERE TEMPERATURES ARE BELOW FREEZING. THERE WILL
ALSO BE SOME SLEET POSSIBLE AT KGAG AND KWWR LATE IN THE FORECAST
PERIOD.
&&
.PREV DISCUSSION... /ISSUED 956 AM CST THU NOV 21 2013/
UPDATE...
COLD FRONT IS MOVING QUICKLY AND IS WELL AHEAD OF SCHEDULE. NONE
OF THE SYNOPTIC SCALE MODELS HAVE DONE WELL WITH THIS TIMING AND
THE TIMING IS EVEN QUICKER THAN THE ACCELERATED TIMING THAT THE
MIDNIGHT SHIFT WORKED IN. HAVE UPDATED THE FORECAST WITH AN EVEN
FASTER ARRIVAL OF THE COLD FRONT CLOSER TO WHAT THE RAP IS
FORECASTING.
PREV DISCUSSION... /ISSUED 625 AM CST THU NOV 21 2013/
DISCUSSION...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
HIGH CONFIDENCE IN MVFR TO IFR CONDITIONS THROUGH THE ENTIRE
FORECAST PERIOD. AN AREA OF SHRA/TSRA WILL CONTINUE TO MOVE ACROSS
NORTHERN OK NEAR PNC THROUGH LATE THIS MORNING. A STRONG COLD
FRONT WILL THEN MOVE INTO WWR/GAG AROUND 14-15Z RESULTING IN A
WIND SHIFT FROM THE NORTH. SUSTAINED WINDS AROUND 25 TO 30 KT...LOW
CIGS...AND EVENTUALLY FZRA/DZ WILL ACCOMPANY THIS ARCTIC FRONT
THROUGH 12Z TOMORROW.
PREV DISCUSSION... /ISSUED 529 AM CST THU NOV 21 2013/
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE ACROSS PORTIONS OF NORTHERN OK
EARLY THIS MORNING WITHIN ZONE OF ISENTROPIC ASCENT AHEAD OF A MID
LEVEL SHORTWAVE TROUGH. EXPECT MOST OF THIS ACTIVITY TO SHIFT OUT
OF OUR FA AROUND 15-18Z. AROUND 430 AM...THE HIGHLY ANTICIPATED
COLD FRONT WAS MOVING INTO SW KS. THIS IS A BIT FASTER THAN MOST
OF THE MODELS SUGGESTED YESTERDAY...WHICH OFTEN OCCURS WITH ARCTIC
AIRMASSES. DECIDED TO SPEED UP THE FRONT CLOSER TO THE FASTEST
SOLUTIONS...THE CANADIAN AND HRRR. EXPECT THE FRONT FROM NEAR PNC
TO KINGFISHER AND ELK CITY AROUND NOON. TEMPS WILL HAVE A CHANCE
TO CLIMB AHEAD OF IT WITHIN SW 850 FLOW ACROSS CENTRAL/SW OK AND
WESTERN NORTH TEXAS FROM THE MID 60S TO UPPER 70S
RESPECTIVELY...BUT WILL QUICKLY DROP BEHIND IT. STILL EXPECT
ENOUGH INSTABILITY AHEAD OF THE FRONT OVER WESTERN NORTH TEXAS AND
SOUTHERN OK FOR SOME STRONGER STORMS TO DEVELOP LATE THIS
AFTERNOON AND EARLY THIS EVENING. THE PRESSURE GRADIENT WITH THE
FRONT WILL ALSO SUPPORT HIGH ENOUGH WINDS FOR AN ADVISORY THROUGH
LATE TONIGHT. THE MAIN CONCERN...HOWEVER...WILL BE POST-FRONTAL
FREEZING RAIN AND DRIZZLE EARLY TOMORROW MORNING.
CONFIDENCE IS HIGH ENOUGH THAT AT LEAST SOME ICING WILL OCCUR ON
ELEVATED SURFACES AS PERSISTENT LIGHT FREEZING RAIN/DRIZZLE
DEVELOPS BEHIND THE FRONT WITH ENOUGH LOW TO MID LEVEL MOISTURE
PRESENT....AND SOME SUBTLE ISENTROPIC ASCENT NEAR SC/S/SW OK. THE
NAM12 IS STILL THE MOST AGGRESSIVE SOLUTION WITH REGARDS TO
QPF...KEEPING SOUTHERLY TO EASTERLY FLOW PRESENT ON THE 290-300K
SURFACES THROUGH FRIDAY MORNING AND THUS MORE SIGNFICANT
ISENTROPIC ASCENT. IT CONTINUES TO BE THE OUTLIER THOUGH AND AM
NOT VERY CONFIDENT IN IT VERIFYING. ALSO HAVE INCLUDED SNOW AND
SLEET FOR W/N/NW OK. THIS IS WHERE A WEAK MID LEVEL SHORTWAVE
TROUGH WILL ROUND A SHORTWAVE RIDGE THROUGH LATE FRIDAY
MORNING...ENOUGH MOISTURE WILL BE PRESENT THROUGH THE DENDRITIC
ZONE...AND DIV ALOFT WILL ASSIST IN LIFT. EXPECT MAYBE AN INCH
ACROSS THE NW ZONES FRIDAY. FREEZING DRIZZLE MAY LINGER MAINLY
ALONG AND SOUTH OF I40 THROUGH LATE FRI NIGHT...BUT DO NOT EXPECT
MUCH ICE ACCUMULATION WITH THIS AS MUCH DRIER LOW-MID LEVEL AIR
QUICKLY DIVES SOUTH.
THE NEXT CHALLENGE IN THE FORECAST WILL BE THE PROGRESSION OF A
CLOSED LOW MOVING OVER THE SW CONUS SUN. SOLUTIONS SUGGEST AT
LEAST A NORTHERN BRANCH OF THE LOW MOVING CLOSER TO OUR NECK OF
THE WOODS WITH THIS SYSTEM. CONFIDENCE IS INCREASING THAT
SNOW/SLEET AND RAIN WILL ACCOMPANY THIS FEATURE SUNDAY THROUGH AT
LEAST MONDAY. WILL CONTINUE TO INCREASE POPS AND MENTION
SNOW...ALTHOUGH AMOUNTS ARE STILL UNCLEAR.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 29 34 29 / 40 70 50 30
HOBART OK 70 27 32 27 / 30 30 40 20
WICHITA FALLS TX 76 32 34 30 / 80 60 60 40
GAGE OK 55 23 27 24 / 20 60 30 20
PONCA CITY OK 57 28 34 29 / 70 40 40 20
DURANT OK 67 41 41 36 / 50 80 60 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR OKZ004>030-033>038.
WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST FRIDAY FOR
OKZ014>017-021>025-027>029-033>038-044.
TX...WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST FRIDAY FOR
TXZ083>086.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
956 AM CST THU NOV 21 2013
.UPDATE...
COLD FRONT IS MOVING QUICKLY AND IS WELL AHEAD OF SCHEDULE. NONE
OF THE SYNOPTIC SCALE MODELS HAVE DONE WELL WITH THIS TIMING AND
THE TIMING IS EVEN QUICKER THAN THE ACCELERATED TIMING THAT THE
MIDNIGHT SHIFT WORKED IN. HAVE UPDATED THE FORECAST WITH AN EVEN
FASTER ARRIVAL OF THE COLD FRONT CLOSER TO WHAT THE RAP IS
FORECASTING.
&&
.PREV DISCUSSION... /ISSUED 625 AM CST THU NOV 21 2013/
DISCUSSION...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
HIGH CONFIDENCE IN MVFR TO IFR CONDITIONS THROUGH THE ENTIRE
FORECAST PERIOD. AN AREA OF SHRA/TSRA WILL CONTINUE TO MOVE ACROSS
NORTHERN OK NEAR PNC THROUGH LATE THIS MORNING. A STRONG COLD
FRONT WILL THEN MOVE INTO WWR/GAG AROUND 14-15Z RESULTING IN A
WIND SHIFT FROM THE NORTH. SUSTAINED WINDS AROUND 25 TO 30 KT...LOW
CIGS...AND EVENTUALLY FZRA/DZ WILL ACCOMPANY THIS ARCTIC FRONT
THROUGH 12Z TOMORROW.
PREV DISCUSSION... /ISSUED 529 AM CST THU NOV 21 2013/
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE ACROSS PORTIONS OF NORTHERN OK
EARLY THIS MORNING WITHIN ZONE OF ISENTROPIC ASCENT AHEAD OF A MID
LEVEL SHORTWAVE TROUGH. EXPECT MOST OF THIS ACTIVITY TO SHIFT OUT
OF OUR FA AROUND 15-18Z. AROUND 430 AM...THE HIGHLY ANTICIPATED
COLD FRONT WAS MOVING INTO SW KS. THIS IS A BIT FASTER THAN MOST
OF THE MODELS SUGGESTED YESTERDAY...WHICH OFTEN OCCURS WITH ARCTIC
AIRMASSES. DECIDED TO SPEED UP THE FRONT CLOSER TO THE FASTEST
SOLUTIONS...THE CANADIAN AND HRRR. EXPECT THE FRONT FROM NEAR PNC
TO KINGFISHER AND ELK CITY AROUND NOON. TEMPS WILL HAVE A CHANCE
TO CLIMB AHEAD OF IT WITHIN SW 850 FLOW ACROSS CENTRAL/SW OK AND
WESTERN NORTH TEXAS FROM THE MID 60S TO UPPER 70S
RESPECTIVELY...BUT WILL QUICKLY DROP BEHIND IT. STILL EXPECT
ENOUGH INSTABILITY AHEAD OF THE FRONT OVER WESTERN NORTH TEXAS AND
SOUTHERN OK FOR SOME STRONGER STORMS TO DEVELOP LATE THIS
AFTERNOON AND EARLY THIS EVENING. THE PRESSURE GRADIENT WITH THE
FRONT WILL ALSO SUPPORT HIGH ENOUGH WINDS FOR AN ADVISORY THROUGH
LATE TONIGHT. THE MAIN CONCERN...HOWEVER...WILL BE POST-FRONTAL
FREEZING RAIN AND DRIZZLE EARLY TOMORROW MORNING.
CONFIDENCE IS HIGH ENOUGH THAT AT LEAST SOME ICING WILL OCCUR ON
ELEVATED SURFACES AS PERSISTENT LIGHT FREEZING RAIN/DRIZZLE
DEVELOPS BEHIND THE FRONT WITH ENOUGH LOW TO MID LEVEL MOISTURE
PRESENT....AND SOME SUBTLE ISENTROPIC ASCENT NEAR SC/S/SW OK. THE
NAM12 IS STILL THE MOST AGGRESSIVE SOLUTION WITH REGARDS TO
QPF...KEEPING SOUTHERLY TO EASTERLY FLOW PRESENT ON THE 290-300K
SURFACES THROUGH FRIDAY MORNING AND THUS MORE SIGNFICANT
ISENTROPIC ASCENT. IT CONTINUES TO BE THE OUTLIER THOUGH AND AM
NOT VERY CONFIDENT IN IT VERIFYING. ALSO HAVE INCLUDED SNOW AND
SLEET FOR W/N/NW OK. THIS IS WHERE A WEAK MID LEVEL SHORTWAVE
TROUGH WILL ROUND A SHORTWAVE RIDGE THROUGH LATE FRIDAY
MORNING...ENOUGH MOISTURE WILL BE PRESENT THROUGH THE DENDRITIC
ZONE...AND DIV ALOFT WILL ASSIST IN LIFT. EXPECT MAYBE AN INCH
ACROSS THE NW ZONES FRIDAY. FREEZING DRIZZLE MAY LINGER MAINLY
ALONG AND SOUTH OF I40 THROUGH LATE FRI NIGHT...BUT DO NOT EXPECT
MUCH ICE ACCUMULATION WITH THIS AS MUCH DRIER LOW-MID LEVEL AIR
QUICKLY DIVES SOUTH.
THE NEXT CHALLENGE IN THE FORECAST WILL BE THE PROGRESSION OF A
CLOSED LOW MOVING OVER THE SW CONUS SUN. SOLUTIONS SUGGEST AT
LEAST A NORTHERN BRANCH OF THE LOW MOVING CLOSER TO OUR NECK OF
THE WOODS WITH THIS SYSTEM. CONFIDENCE IS INCREASING THAT
SNOW/SLEET AND RAIN WILL ACCOMPANY THIS FEATURE SUNDAY THROUGH AT
LEAST MONDAY. WILL CONTINUE TO INCREASE POPS AND MENTION
SNOW...ALTHOUGH AMOUNTS ARE STILL UNCLEAR.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 29 34 29 / 40 70 50 30
HOBART OK 70 27 32 27 / 30 30 40 20
WICHITA FALLS TX 76 32 34 30 / 80 60 60 40
GAGE OK 55 23 27 24 / 20 60 30 20
PONCA CITY OK 57 28 34 29 / 70 40 40 20
DURANT OK 67 41 41 36 / 50 80 60 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR OKZ004>030-033>038.
WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST FRIDAY FOR
OKZ014>017-021>025-027>029-033>038-044.
TX...WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST FRIDAY FOR
TXZ083>086.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
743 PM CST FRI NOV 22 2013
.UPDATE...
UPDATED TO REDUCE RAIN CHANCES ACROSS THE EAST THIS EVENING.
&&
.DISCUSSION...
CURRENT RADAR TRENDS AND HRRR MODEL RUN INDICATING PRECIPITATION
HOLDING OFF ON DEVELOPMENT AND SPREADING EAST INTO NORTHEAST
MISSISSIPPI UNTIL AFTER 08Z TONIGHT. HAVE REDUCED RAIN CHANCES
ACCORDINGLY. ALL OTHER FORECAST PARAMETERS ARE CURRENTLY ON TRACK.
JAB
&&
.PREV DISCUSSION... /ISSUED 402 PM CST FRI NOV 22 2013/
DISCUSSION...
CURRENTLY...
THE COLD FRONT IS NOW LOCATED FROM EASTERN OHIO...DOWN THROUGH
MIDDLE TENNESSEE...AND INTO CENTRAL MISSISSIPPI. NNW WINDS ARE
RELATIVELY STRONG WITH SUSTAINED 15-20 MPH WITH SOME GUSTS TO 25
MPH. STRONG CAA IS CURRENTLY TAKING PLACE JUST TO THE NORTH OF THE
MID-SOUTH...WITH WIDESPREAD 30S LOCATED ACROSS SOUTHERN MISSOURI.
TEMPERATURES WILL CONTINUE TO COOL THROUGH THIS EVENING WITH LOWS
BOTTOMING OUT IN THE UPPER 30S AND LOWER 40S.
ANOTHER VORT MAX WILL PUSH THROUGH THE MID-SOUTH
OVERNIGHT...TRIGGERING SOME SHOWERS OVER MOST OF THE MID-SOUTH
WITH RAIN CHANCES TAPERING OFF BY MID-MORNING ON SATURDAY. EXTREME
NORTHEAST ARKANSAS MAY SEE A BRIEF CHANCE OF SOME SLEET EARLY IN
THE MORNING ON SATURDAY.
TEMPERATURES DURING THE DAY ON SATURDAY WILL REMAIN COOL...WITH
HIGHS NEAR 50 DEGREES. THE COLDEST AIR THAT WE HAVE SEEN SINCE
LAST WEEK WILL MOVE INTO THE REGION AND STAY PUT THROUGH EARLY
NEXT WEEK. HIGH PRESSURE WILL CENTER OVER THE MID-SOUTH OVERNIGHT
ON SUNDAY...LOWERING TEMPERATURES INTO THE LOW 20S AND EVEN SOME
TEENS IN OUR NORTHERN COUNTIES UNDER CLEAR SKIES.
..SUNDAY THROUGH WEDNESDAY...
COLD AIR WILL REMAIN IN PLACE ON SUNDAY AFTERNOON...WITH HIGHS
ONLY REACHING INTO THE 30S IN WEST TENNESSEE AND NORTHEAST
ARKANSAS...WITH NORTH MISSISSIPPI IN THE LOW 40S. WITH THE COLD
AIR IN PLACE...A CUTOFF LOW WILL BEGIN TO MEANDER INTO THE MID-
SOUTH SUNDAY NIGHT...BRINGING MOISTURE INTO THE MAJORITY OF THE REGION.
MODEL GUIDANCE SUGGESTS THAT THE CUTOFF LOW WILL TAKE A MORE
SOUTHERN ROUTE...WHICH SHOULD DRAW MORE MOISTURE INTO THE REGION
EVEN WITH A DRY AIRMASS IN PLACE. THE ISSUE STILL LIES WITH
TIMING...AS THE GFS MOVES THE SYSTEM THROUGH A TAD BIT QUICKER
THAN THE ECMWF. THE SLOWER TIMING OF THE ECMWF KEEPS THE REGION IN
A WARM SECTOR LONGER...WHICH COULD OFFSET THE COOLING NEEDED FOR
ANY KIND OF MIXED PRECIPITATION.
THE FIRST CHANCE FOR ANY MENTIONABLE FROZEN PRECIPITATION STARTS
MONDAY MORNING FOR THE NORTHERN PARTS OF NORTHEAST ARKANSAS AND
WEST TENNESSEE...BUT ONLY A SLIGHT CHANCE ATTM. MODEL SOUNDINGS
TEMPERATURES ARE RIGHT ON THE EDGE OF BEING JUST COOL ENOUGH TO
POSSIBLY SUPPORT SOME SLEET/FREEZING RAIN. ONCE THE SUN GOES DOWN ON
MONDAY...A LARGER PORTION OF WEST TENNESSEE AND NORTHEAST ARKANSAS
WILL SEE A CHANCE OF SLEET AND OR SNOW DEPENDING ON THE AMOUNT
SATURATION IN THE HIGHER LEVELS OF THE ATMOSPHERE.
ON WEDNESDAY...ANOTHER BRIEF CHANCE OF SNOW WILL BE POSSIBLE IN
THE MORNING ACROSS A LARGER PART OF THE CWA AS THE UPPER LEVEL LOW
EXITS THE REGION. HIGH PRESSURE WILL BUILD INTO THE MID-SOUTH ON
THURSDAY INTO THE WEEKEND WITH TEMPERATURES WARMING INTO THE
UPPER 40S AND LOWER 50S FOR THANKSGIVING DAY.
AC3
&&
.AVIATION...
00Z TAF CYCLE
A MIX OF MVFR AND IFR CIGS PREVAIL AT THE TERMINALS THIS EVENING
AND SHOULD CONTINUE THROUGH THE NIGHT. MVFR CIGS ARE COMMON AT
KJBR AND KMEM...WHEREAS IFR CIGS PREVAIL AT KMKL AND KTUP. THERE
MAY BE TEMPORARY IFR REDUCTIONS LATER TONIGHT AT KMEM ALSO. IN
ADDITION TO THE LOW CIGS...EXPECT INCREASING LIGHT RAIN CHANCES
SPREADING FROM WEST TO EAST LATER THIS EVENING INTO EARLY SATURDAY
MORNING. THE GREATEST RAIN POTENTIAL WILL EXIST AT KTUP. WINDS
WILL REMAIN STRONG AND GUSTY FROM THE NORTH BEHIND A COLD FRONT
THAT MOVED ACROSS THE AREA EARLIER TODAY.
LOW CIGS WILL QUICKLY IMPROVE AT ALL TERMINALS SATURDAY MORNING AS
A DRIER AIRMASS MOVES INTO THE REGION. SOUTHWEST FLOW ALOFT WILL
HELP TO MAINTAIN A BROKEN MID LEVEL CLOUD DECK THROUGH MUCH OF THE
DAY BUT CONDITIONS SHOULD REMAIN VFR FROM MID MORNING ONWARD.
GUSTY NORTH WINDS WILL CONTINUE THROUGH SATURDAY AT ALL SITES.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 40 48 25 40 / 50 10 0 0
MKL 39 48 20 37 / 30 10 0 0
JBR 36 46 23 36 / 50 0 0 0
TUP 45 52 24 43 / 50 20 10 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1156 AM CST THU NOV 21 2013
.UPDATE...
UPDATED FOR AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1032 AM CST THU NOV 21 2013/
UPDATE...MORNING UPDATE.
CURRENTLY...A COLD FRONT EXTENDS FROM NORTHWEST MISSOURI...THROUGH
EASTERN KANSAS...AND PARALLEL TO THE OKLAHOMA PANHANDLE. MOST
HEAVY RAIN IS OCCURRING OUT AHEAD OF THE FRONT...WHERE WAA OVERRUNNING
IS OCCURRING IN SOUTHERN MISSOURI AND EASTERN KANSAS. TEMPERATURES
BEHIND THE FRONT ARE IN THE 30S...WITH 50S OUT AHEAD OF THE FRONT.
TEMPERATURES ACROSS THE MID-SOUTH ARE HOLDING STEADY IN THE UPPER
50S AND SLOWLY WARMING UNDER PARTLY SUNNY SKIES AND MODERATE WAA.
TEMPERATURES TODAY MAY LEVEL OUT SOONER RATHER THAN LATER...DUE TO
THE ABUNDANT CLOUD COVER LOCATED JUST TO THE WEST OF THE
MISSISSIPPI RIVER. WINDS ARE BEGINNING TO GUST A BIT...PREDOMINANTLY
NEAR THE MISSISSIPPI RIVER...WITH GUSTS TO 20 MPH OUT OF THE SSE.
RAIN SHOWERS ARE CURRENTLY HOLDING BACK IN CENTRAL ARKANSAS...BUT
ARE EXPECTED TO MOVE INTO THE MEMPHIS METRO AREA AROUND 5PM WITH
WIDESPREAD SHOWERS DEVELOPING LATER THIS EVENING.
FORECAST IS ON TRACK AND NO IMMEDIATE CHANGES ARE NEEDED.
AC3
PREV DISCUSSION... /ISSUED 525 AM CST THU NOV 21 2013/
DISCUSSION...
A DEVELOPING LOW PRESSURE SYSTEM NEAR THE OKLAHOMA PANHANDLE IS
ALREADY BEGINNING TO SPREAD RAIN INTO NORTH CENTRAL ARKANSAS.
EXPECT THIS BAND TO CONTINUE PUSHING EAST THIS MORNING AND WILL
PUSH INTO NORTHEAST ARKANSAS BY LATER THIS MORNING. IN
ADDITION...LATEST HRRR CONTINUES TO SHOW SPOTTY WAA SHOWERS
DEVELOPING THIS MORNING INTO THIS AFTERNOON OVER A GOOD PORTION OF
THE CWA. AS A RESULT...HAVE EITHER BUMPED UP POPS OR ADDED POPS TO
MUCH OF THE CWA. THE ONLY LOCATIONS THAT MAY STAY DRY WILL BE LONG
THE TENNESSEE RIVER IN WEST TENNESSEE AND NORTHEAST MISSISSIPPI.
IN ADDITION...STRATUS CONTINUES TO STREAM TOWARD NORTHEAST
MISSISSIPPI FROM THE SOUTHEAST WHILE ABUNDANT MID TO HIGH CLOUDS
STREAM IN FROM THE WEST. THUS EXPECT BY THIS AFTERNOON THE ENTIRE
CWA WILL BE MOSTLY CLOUDY. THE CLOUDS AND SHOWERS MAY HINDER
TEMPERATURES FROM WARMING AS MUCH AS PREVIOUSLY THOUGHT BUT SINCE
THERE IS DECENT WAA OCCURRING TODAY HAVE LEFT HIGHS RANGING FROM
THE LOWER 60S TO UPPER 60S FOR NOW.
BY TONIGHT...EXPECT RAIN TO BE FALLING ACROSS AT LEAST THE
EASTERN ARKANSAS...THE MISSOURI BOOTHEEL...MUCH OF WEST TENNESSEE
AND NORTHWEST MISSISSIPPI. THE ASSOCIATED COLD FRONT WILL BEGIN TO
PUSH INTO THE AREA AFTER MIDNIGHT. CAN/T RULE OUT A FEW EMBEDDED
THUNDERSTORMS OCCURRING AHEAD OF THE FRONT. THE FRONT WILL
CONTINUE TO PUSH THROUGH THE MIDSOUTH ON FRIDAY INTO FRIDAY NIGHT
NUMEROUS TO WIDESPREAD SHOWERS WILL OCCUR ON FRIDAY AND FRIDAY
NIGHT ACROSS THE ENTIRE MIDSOUTH. COLDER AIR WILL USHER INTO THE
MIDSOUTH BEHIND THE FRONT. EXPECT HIGHS ON SATURDAY TO OCCUR IN
THE MORNING WITH NEAR STEADY TEMPERATURES OR SLIGHTLY FALLING
TEMPERATURES IN THE AFTERNOON. SOME LINGERING RAIN MAY OCCUR
ACROSS NORTH MISSISSIPPI SATURDAY MORNING OTHERWISE CONDITIONS
WILL BE DRY. EXPECT THE HIGHS ON SATURDAY MORNING TO BE IN THE THE
LOWER 40S TO LOWER 50S WITH TEMPERATURES DROPPING INTO UPPER 30S
TO UPPER 40S IN THE AFTERNOON.
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE MIDSOUTH ON SUNDAY BUT BY
SUNDAY NIGHT CLOUDS WILL BEGIN INCREASING AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM ALONG THE GULF COAST WHICH WOULD IMPACT THE
MIDSOUTH MONDAY THROUGH TUESDAY EVENING. WITH COLD AIR IN
PLACE...THIS IS A SYSTEM THAT BEARS WATCHING. PRECIPITATION WILL BEGIN TO
SPREAD INTO THE MIDSOUTH SUNDAY EVENING. EXPECT LOWS TO ACTUALLY OCCUR
IN THE EVENING. TEMPERATURES WILL LIKELY HOLD STEADY OR SLIGHTLY
RISE AFTER MIDNIGHT AS CLOUDS AHEAD OF THE SYSTEM SPREAD INTO THE
AREA. THE BIG QUESTION WILL BE WHAT THE TEMPERATURE IS AT A GIVEN
LOCATION WHEN THE PRECIPITATION STARTS. EXPECT MOST LOCATIONS TO
BE NEAR OR SLIGHTLY ABOVE FREEZING THUS PRECIPITATION WILL LIKELY
BE RAIN. HOWEVER WOULD NOT BE SURPRISED TO SEE AN INITIAL PERIOD
OF SLEET OCCUR DUE TO THE AMOUNT OF DRY AIR IN THE LOW LEVELS TO
OVERCOME BEFORE RAIN REACHES THE SURFACE. THE POSSIBLE EXCEPTION
MAY BE EXTREME NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND
EXTREME NORTHWEST TENNESSEE WHERE TEMPERATURES MAY BE SLIGHTLY
BELOW FREEZING THUS ALLOWING PRECIPITATION WOULD FALL AS SNOW BUT
AGAIN COULD INITIALLY BEGIN AS SLEET. EVEN IF THIS WOULD OCCUR THE
GROUND IS TOO WARM FOR ANY ACCUMULATION TO OCCUR. ANY SNOW THAT
WOULD BE OCCURRING MONDAY MORNING WOULD QUICKLY CHANGEOVER TO RAIN
AS TEMPERATURES RISE ABOVE FREEZING.
AS THE SFC LOW TRACKS EASTWARD ALONG THE GULF COAST...COLDER AIR
WILL BEGIN TO WRAP AROUND THE BACK SIDE OF THE LOW ON TUESDAY INTO
TUESDAY NIGHT. BOTH THE 00Z ECMWF AND THE 00Z GFS SHOW THAT
TEMPERATURES WILL BE FALLING ON TUESDAY. ONE THING THAT BEARS
WATCHING IS HOW LOW THE TEMPERATURES DROP TUESDAY AFTERNOON INTO
TUESDAY NIGHT AS THE POTENT UPPER LOW SWINGS INTO THE AREA BEHIND
THE DEPARTING SFC LOW. THE 00Z ECMWF IS COLDER THAN THE 00Z GFS
WHICH IF ECMWF SOLUTION WERE TO END UP BEING
CORRECT...PRECIPITATION COULD CHANGEOVER TO SNOW TUESDAY NIGHT.
HOWEVER A LOT OF TIMES...THE PRECIPITATION CUTS OFF BEFORE THE
REALLY COLD AIR GETS INTO THE AREA SO WILL JUST HAVE TO WAIT AND
SEE. COLD HIGH PRESSURE WILL BUILD INTO THE MIDSOUTH ON WEDNESDAY. THE
ONLY SURE BET FROM THE WEEKEND TIME PERIOD THROUGH THE END OF THE
FORECAST PERIOD IS THAT TEMPERATURES WILL BE WAY BELOW NORMAL.
HIGHS WILL RANGE FROM THE MID 30S TO THE UPPER 40S.
KRM
&&
.AVIATION...
18Z TAFS
MOIST GULF AIR WAS FLOWING INTO THE MIDSOUTH A LITTLE AHEAD OF
SCHEDULE 1730Z. WIDESPREAD SHOWERS WERE NOTED ON RADAR AROUND
JBR AND SHOULD BE INTO MEM TOWARD 20Z. MVFR CIGS HAD STREAMED
NORTH THROUGH THE DELTA INTO MEM...AND EXPECT THE CLEAR SPOT
BETWEEN TUP AND MKL TO CLOSE DOWN BY MID AFTERNOON. JBR AND MEM
WILL LIKELY SEE CIGS DROP BELOW THE FL020 FUEL ALTERNATE THIS
AFTERNOON. AMD FOR BOTH SITES HAVE BEEN SENT ACCORDINGLY.
PREFRONTAL IFR CIGS APPEAR A GOOD BET BY LATE EVENING...PERSISTING
THROUGH THE OVERNIGHT...AHEAD OF THE APPROACHING COLD FRONT.
VSBY SHOULD IMPROVE WITH THE ARRIVAL OF THE ARCTIC AIR 11Z TO 14Z...
BUT POST FRONTAL IFR CIGS WILL LIKELY BE QUITE STUBBORN TO IMPROVE
TO MVFR BY 22/18Z.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1032 AM CST THU NOV 21 2013
.UPDATE...MORNING UPDATE.
CURRENTLY...A COLD FRONT EXTENDS FROM NORTHWEST MISSOURI...THROUGH
EASTERN KANSAS...AND PARALLEL TO THE OKLAHOMA PANHANDLE. MOST
HEAVY RAIN IS OCCURRING OUT AHEAD OF THE FRONT...WHERE WAA OVERRUNNING
IS OCCURRING IN SOUTHERN MISSOURI AND EASTERN KANSAS. TEMPERATURES
BEHIND THE FRONT ARE IN THE 30S...WITH 50S OUT AHEAD OF THE FRONT.
TEMPERATURES ACROSS THE MID-SOUTH ARE HOLDING STEADY IN THE UPPER
50S AND SLOWLY WARMING UNDER PARTLY SUNNY SKIES AND MODERATE WAA.
TEMPERATURES TODAY MAY LEVEL OUT SOONER RATHER THAN LATER...DUE TO
THE ABUNDANT CLOUD COVER LOCATED JUST TO THE WEST OF THE
MISSISSIPPI RIVER. WINDS ARE BEGINNING TO GUST A BIT...PREDOMINANTLY
NEAR THE MISSISSIPPI RIVER...WITH GUSTS TO 20 MPH OUT OF THE SSE.
RAIN SHOWERS ARE CURRENTLY HOLDING BACK IN CENTRAL ARKANSAS...BUT
ARE EXPECTED TO MOVE INTO THE MEMPHIS METRO AREA AROUND 5PM WITH
WIDESPREAD SHOWERS DEVELOPING LATER THIS EVENING.
FORECAST IS ON TRACK AND NO IMMEDIATE CHANGES ARE NEEDED.
AC3
&&
.PREV DISCUSSION... /ISSUED 525 AM CST THU NOV 21 2013/
&&
.DISCUSSION...
A DEVELOPING LOW PRESSURE SYSTEM NEAR THE OKLAHOMA PANHANDLE IS
ALREADY BEGINNING TO SPREAD RAIN INTO NORTH CENTRAL ARKANSAS.
EXPECT THIS BAND TO CONTINUE PUSHING EAST THIS MORNING AND WILL
PUSH INTO NORTHEAST ARKANSAS BY LATER THIS MORNING. IN
ADDITION...LATEST HRRR CONTINUES TO SHOW SPOTTY WAA SHOWERS
DEVELOPING THIS MORNING INTO THIS AFTERNOON OVER A GOOD PORTION OF
THE CWA. AS A RESULT...HAVE EITHER BUMPED UP POPS OR ADDED POPS TO
MUCH OF THE CWA. THE ONLY LOCATIONS THAT MAY STAY DRY WILL BE LONG
THE TENNESSEE RIVER IN WEST TENNESSEE AND NORTHEAST MISSISSIPPI.
IN ADDITION...STRATUS CONTINUES TO STREAM TOWARD NORTHEAST
MISSISSIPPI FROM THE SOUTHEAST WHILE ABUNDANT MID TO HIGH CLOUDS
STREAM IN FROM THE WEST. THUS EXPECT BY THIS AFTERNOON THE ENTIRE
CWA WILL BE MOSTLY CLOUDY. THE CLOUDS AND SHOWERS MAY HINDER
TEMPERATURES FROM WARMING AS MUCH AS PREVIOUSLY THOUGHT BUT SINCE
THERE IS DECENT WAA OCCURRING TODAY HAVE LEFT HIGHS RANGING FROM
THE LOWER 60S TO UPPER 60S FOR NOW.
BY TONIGHT...EXPECT RAIN TO BE FALLING ACROSS AT LEAST THE
EASTERN ARKANSAS...THE MISSOURI BOOTHEEL...MUCH OF WEST TENNESSEE
AND NORTHWEST MISSISSIPPI. THE ASSOCIATED COLD FRONT WILL BEGIN TO
PUSH INTO THE AREA AFTER MIDNIGHT. CAN/T RULE OUT A FEW EMBEDDED
THUNDERSTORMS OCCURRING AHEAD OF THE FRONT. THE FRONT WILL
CONTINUE TO PUSH THROUGH THE MIDSOUTH ON FRIDAY INTO FRIDAY NIGHT
NUMEROUS TO WIDESPREAD SHOWERS WILL OCCUR ON FRIDAY AND FRIDAY
NIGHT ACROSS THE ENTIRE MIDSOUTH. COLDER AIR WILL USHER INTO THE
MIDSOUTH BEHIND THE FRONT. EXPECT HIGHS ON SATURDAY TO OCCUR IN
THE MORNING WITH NEAR STEADY TEMPERATURES OR SLIGHTLY FALLING
TEMPERATURES IN THE AFTERNOON. SOME LINGERING RAIN MAY OCCUR
ACROSS NORTH MISSISSIPPI SATURDAY MORNING OTHERWISE CONDITIONS
WILL BE DRY. EXPECT THE HIGHS ON SATURDAY MORNING TO BE IN THE THE
LOWER 40S TO LOWER 50S WITH TEMPERATURES DROPPING INTO UPPER 30S
TO UPPER 40S IN THE AFTERNOON.
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE MIDSOUTH ON SUNDAY BUT BY
SUNDAY NIGHT CLOUDS WILL BEGIN INCREASING AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM ALONG THE GULF COAST WHICH WOULD IMPACT THE
MIDSOUTH MONDAY THROUGH TUESDAY EVENING. WITH COLD AIR IN
PLACE...THIS IS A SYSTEM THAT BEARS WATCHING. PRECIPITATION WILL BEGIN TO
SPREAD INTO THE MIDSOUTH SUNDAY EVENING. EXPECT LOWS TO ACTUALLY OCCUR
IN THE EVENING. TEMPERATURES WILL LIKELY HOLD STEADY OR SLIGHTLY
RISE AFTER MIDNIGHT AS CLOUDS AHEAD OF THE SYSTEM SPREAD INTO THE
AREA. THE BIG QUESTION WILL BE WHAT THE TEMPERATURE IS AT A GIVEN
LOCATION WHEN THE PRECIPITATION STARTS. EXPECT MOST LOCATIONS TO
BE NEAR OR SLIGHTLY ABOVE FREEZING THUS PRECIPITATION WILL LIKELY
BE RAIN. HOWEVER WOULD NOT BE SURPRISED TO SEE AN INITIAL PERIOD
OF SLEET OCCUR DUE TO THE AMOUNT OF DRY AIR IN THE LOW LEVELS TO
OVERCOME BEFORE RAIN REACHES THE SURFACE. THE POSSIBLE EXCEPTION
MAY BE EXTREME NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND
EXTREME NORTHWEST TENNESSEE WHERE TEMPERATURES MAY BE SLIGHTLY
BELOW FREEZING THUS ALLOWING PRECIPITATION WOULD FALL AS SNOW BUT
AGAIN COULD INITIALLY BEGIN AS SLEET. EVEN IF THIS WOULD OCCUR THE
GROUND IS TOO WARM FOR ANY ACCUMULATION TO OCCUR. ANY SNOW THAT
WOULD BE OCCURRING MONDAY MORNING WOULD QUICKLY CHANGEOVER TO RAIN
AS TEMPERATURES RISE ABOVE FREEZING.
AS THE SFC LOW TRACKS EASTWARD ALONG THE GULF COAST...COLDER AIR
WILL BEGIN TO WRAP AROUND THE BACK SIDE OF THE LOW ON TUESDAY INTO
TUESDAY NIGHT. BOTH THE 00Z ECMWF AND THE 00Z GFS SHOW THAT
TEMPERATURES WILL BE FALLING ON TUESDAY. ONE THING THAT BEARS
WATCHING IS HOW LOW THE TEMPERATURES DROP TUESDAY AFTERNOON INTO
TUESDAY NIGHT AS THE POTENT UPPER LOW SWINGS INTO THE AREA BEHIND
THE DEPARTING SFC LOW. THE 00Z ECMWF IS COLDER THAN THE 00Z GFS
WHICH IF ECMWF SOLUTION WERE TO END UP BEING
CORRECT...PRECIPITATION COULD CHANGEOVER TO SNOW TUESDAY NIGHT.
HOWEVER A LOT OF TIMES...THE PRECIPITATION CUTS OFF BEFORE THE
REALLY COLD AIR GETS INTO THE AREA SO WILL JUST HAVE TO WAIT AND
SEE. COLD HIGH PRESSURE WILL BUILD INTO THE MIDSOUTH ON WEDNESDAY. THE
ONLY SURE BET FROM THE WEEKEND TIME PERIOD THROUGH THE END OF THE
FORECAST PERIOD IS THAT TEMPERATURES WILL BE WAY BELOW NORMAL.
HIGHS WILL RANGE FROM THE MID 30S TO THE UPPER 40S.
KRM
&&
.AVIATION...
12Z TAF CYCLE
STRATUS SEEMS TO STILL HAVING TROUBLE MAKING IT TO TUP...BUT STILL
FEEL LIKE IT WILL MAKE IN BY SUNRISE. OTHERWISE VFR AT THE OTHER
SITES THROUGH MOST OF THE DAY.
LIGHT SHOWERS WILL BEGIN TO APPROACH JBR DURING THE MID
AFTERNOON...MEM SLIGHTLY BEFORE SUNSET...MKL JUST AFTER
SUNSET...AND TUP BY MIDNIGHT...STEADY RAIN WILL FOLLOW BY 3-4
HOURS. CIGS WILL LOWER TO MVFR LEVELS AS THE STEADIER RAIN
BEGINS...AND LIKELY TO IFR LEVELS BY MIDNIGHT AT ALL SITES.
WINDS SOUTHEAST 5 TO 10 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 67 57 60 42 / 30 70 100 70
MKL 66 54 59 41 / 20 50 100 60
JBR 62 52 54 37 / 40 100 90 40
TUP 68 55 65 47 / 10 20 70 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
525 AM CST THU NOV 21 2013
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 347 AM CST THU NOV 21 2013/
DISCUSSION...
A DEVELOPING LOW PRESSURE SYSTEM NEAR THE OKLAHOMA PANHANDLE IS
ALREADY BEGINNING TO SPREAD RAIN INTO NORTH CENTRAL ARKANSAS.
EXPECT THIS BAND TO CONTINUE PUSHING EAST THIS MORNING AND WILL
PUSH INTO NORTHEAST ARKANSAS BY LATER THIS MORNING. IN
ADDITION...LATEST HRRR CONTINUES TO SHOW SPOTTY WAA SHOWERS
DEVELOPING THIS MORNING INTO THIS AFTERNOON OVER A GOOD PORTION OF
THE CWA. AS A RESULT...HAVE EITHER BUMPED UP POPS OR ADDED POPS TO
MUCH OF THE CWA. THE ONLY LOCATIONS THAT MAY STAY DRY WILL BE LONG
THE TENNESSEE RIVER IN WEST TENNESSEE AND NORTHEAST MISSISSIPPI.
IN ADDITION...STRATUS CONTINUES TO STREAM TOWARD NORTHEAST
MISSISSIPPI FROM THE SOUTHEAST WHILE ABUNDANT MID TO HIGH CLOUDS
STREAM IN FROM THE WEST. THUS EXPECT BY THIS AFTERNOON THE ENTIRE
CWA WILL BE MOSTLY CLOUDY. THE CLOUDS AND SHOWERS MAY HINDER
TEMPERATURES FROM WARMING AS MUCH AS PREVIOUSLY THOUGHT BUT SINCE
THERE IS DECENT WAA OCCURRING TODAY HAVE LEFT HIGHS RANGING FROM
THE LOWER 60S TO UPPER 60S FOR NOW.
BY TONIGHT...EXPECT RAIN TO BE FALLING ACROSS AT LEAST THE
EASTERN ARKANSAS...THE MISSOURI BOOTHEEL...MUCH OF WEST TENNESSEE
AND NORTHWEST MISSISSIPPI. THE ASSOCIATED COLD FRONT WILL BEGIN TO
PUSH INTO THE AREA AFTER MIDNIGHT. CAN/T RULE OUT A FEW EMBEDDED
THUNDERSTORMS OCCURRING AHEAD OF THE FRONT. THE FRONT WILL
CONTINUE TO PUSH THROUGH THE MIDSOUTH ON FRIDAY INTO FRIDAY NIGHT
NUMEROUS TO WIDESPREAD SHOWERS WILL OCCUR ON FRIDAY AND FRIDAY
NIGHT ACROSS THE ENTIRE MIDSOUTH. COLDER AIR WILL USHER INTO THE
MIDSOUTH BEHIND THE FRONT. EXPECT HIGHS ON SATURDAY TO OCCUR IN
THE MORNING WITH NEAR STEADY TEMPERATURES OR SLIGHTLY FALLING
TEMPERATURES IN THE AFTERNOON. SOME LINGERING RAIN MAY OCCUR
ACROSS NORTH MISSISSIPPI SATURDAY MORNING OTHERWISE CONDITIONS
WILL BE DRY. EXPECT THE HIGHS ON SATURDAY MORNING TO BE IN THE THE
LOWER 40S TO LOWER 50S WITH TEMPERATURES DROPPING INTO UPPER 30S
TO UPPER 40S IN THE AFTERNOON.
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE MIDSOUTH ON SUNDAY BUT BY
SUNDAY NIGHT CLOUDS WILL BEGIN INCREASING AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM ALONG THE GULF COAST WHICH WOULD IMPACT THE
MIDSOUTH MONDAY THROUGH TUESDAY EVENING. WITH COLD AIR IN
PLACE...THIS IS A SYSTEM THAT BEARS WATCHING. PRECIPITATION WILL BEGIN TO
SPREAD INTO THE MIDSOUTH SUNDAY EVENING. EXPECT LOWS TO ACTUALLY OCCUR
IN THE EVENING. TEMPERATURES WILL LIKELY HOLD STEADY OR SLIGHTLY
RISE AFTER MIDNIGHT AS CLOUDS AHEAD OF THE SYSTEM SPREAD INTO THE
AREA. THE BIG QUESTION WILL BE WHAT THE TEMPERATURE IS AT A GIVEN
LOCATION WHEN THE PRECIPITATION STARTS. EXPECT MOST LOCATIONS TO
BE NEAR OR SLIGHTLY ABOVE FREEZING THUS PRECIPITATION WILL LIKELY
BE RAIN. HOWEVER WOULD NOT BE SURPRISED TO SEE AN INITIAL PERIOD
OF SLEET OCCUR DUE TO THE AMOUNT OF DRY AIR IN THE LOW LEVELS TO
OVERCOME BEFORE RAIN REACHES THE SURFACE. THE POSSIBLE EXCEPTION
MAY BE EXTREME NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND
EXTREME NORTHWEST TENNESSEE WHERE TEMPERATURES MAY BE SLIGHTLY
BELOW FREEZING THUS ALLOWING PRECIPITATION WOULD FALL AS SNOW BUT
AGAIN COULD INITIALLY BEGIN AS SLEET. EVEN IF THIS WOULD OCCUR THE
GROUND IS TOO WARM FOR ANY ACCUMULATION TO OCCUR. ANY SNOW THAT
WOULD BE OCCURRING MONDAY MORNING WOULD QUICKLY CHANGEOVER TO RAIN
AS TEMPERATURES RISE ABOVE FREEZING.
AS THE SFC LOW TRACKS EASTWARD ALONG THE GULF COAST...COLDER AIR
WILL BEGIN TO WRAP AROUND THE BACK SIDE OF THE LOW ON TUESDAY INTO
TUESDAY NIGHT. BOTH THE 00Z ECMWF AND THE 00Z GFS SHOW THAT
TEMPERATURES WILL BE FALLING ON TUESDAY. ONE THING THAT BEARS
WATCHING IS HOW LOW THE TEMPERATURES DROP TUESDAY AFTERNOON INTO
TUESDAY NIGHT AS THE POTENT UPPER LOW SWINGS INTO THE AREA BEHIND
THE DEPARTING SFC LOW. THE 00Z ECMWF IS COLDER THAN THE 00Z GFS
WHICH IF ECMWF SOLUTION WERE TO END UP BEING
CORRECT...PRECIPITATION COULD CHANGEOVER TO SNOW TUESDAY NIGHT.
HOWEVER A LOT OF TIMES...THE PRECIPITATION CUTS OFF BEFORE THE
REALLY COLD AIR GETS INTO THE AREA SO WILL JUST HAVE TO WAIT AND
SEE. COLD HIGH PRESSURE WILL BUILD INTO THE MIDSOUTH ON WEDNESDAY. THE
ONLY SURE BET FROM THE WEEKEND TIME PERIOD THROUGH THE END OF THE
FORECAST PERIOD IS THAT TEMPERATURES WILL BE WAY BELOW NORMAL.
HIGHS WILL RANGE FROM THE MID 30S TO THE UPPER 40S.
KRM
&&
.AVIATION...
06Z TAF CYCLE
STRATUS SEEMS TO STILL HAVING TROUBLE MAKING IT TO TUP...BUT STILL
FEEL LIKE IT WILL MAKE IN BY SUNRISE. OTHERWISE VFR AT THE OTHER
SITES THROUGH MOST OF THE DAY.
LIGHT SHOWERS WILL BEGIN TO APPROACH JBR DURING THE MID
AFTERNOON...MEM SLIGHTLY BEFORE SUNSET...MKL JUST AFTER
SUNSET...AND TUP BY MIDNIGHT...STEADY RAIN WILL FOLLOW BY 3-4
HOURS. CIGS WILL LOWER TO MVFR LEVELS AS THE STEADIER RAIN
BEGINS...AND LIKELY TO IFR LEVELS BY MIDNIGHT AT ALL SITES.
WINDS SOUTHEAST 5 TO 10 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 67 57 60 42 / 30 70 100 70
MKL 66 54 59 41 / 20 50 100 60
JBR 62 52 54 37 / 40 100 90 40
TUP 68 55 65 47 / 10 20 70 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
347 AM CST THU NOV 21 2013
.DISCUSSION...
A DEVELOPING LOW PRESSURE SYSTEM NEAR THE OKLAHOMA PANHANDLE IS
ALREADY BEGINNING TO SPREAD RAIN INTO NORTH CENTRAL ARKANSAS.
EXPECT THIS BAND TO CONTINUE PUSHING EAST THIS MORNING AND WILL
PUSH INTO NORTHEAST ARKANSAS BY LATER THIS MORNING. IN
ADDITION...LATEST HRRR CONTINUES TO SHOW SPOTTY WAA SHOWERS
DEVELOPING THIS MORNING INTO THIS AFTERNOON OVER A GOOD PORTION OF
THE CWA. AS A RESULT...HAVE EITHER BUMPED UP POPS OR ADDED POPS TO
MUCH OF THE CWA. THE ONLY LOCATIONS THAT MAY STAY DRY WILL BE LONG
THE TENNESSEE RIVER IN WEST TENNESSEE AND NORTHEAST MISSISSIPPI.
IN ADDITION...STRATUS CONTINUES TO STREAM TOWARD NORTHEAST
MISSISSIPPI FROM THE SOUTHEAST WHILE ABUNDANT MID TO HIGH CLOUDS
STREAM IN FROM THE WEST. THUS EXPECT BY THIS AFTERNOON THE ENTIRE
CWA WILL BE MOSTLY CLOUDY. THE CLOUDS AND SHOWERS MAY HINDER
TEMPERATURES FROM WARMING AS MUCH AS PREVIOUSLY THOUGHT BUT SINCE
THERE IS DECENT WAA OCCURRING TODAY HAVE LEFT HIGHS RANGING FROM
THE LOWER 60S TO UPPER 60S FOR NOW.
BY TONIGHT...EXPECT RAIN TO BE FALLING ACROSS AT LEAST THE
EASTERN ARKANSAS...THE MISSOURI BOOTHEEL...MUCH OF WEST TENNESSEE
AND NORTHWEST MISSISSIPPI. THE ASSOCIATED COLD FRONT WILL BEGIN TO
PUSH INTO THE AREA AFTER MIDNIGHT. CAN/T RULE OUT A FEW EMBEDDED
THUNDERSTORMS OCCURRING AHEAD OF THE FRONT. THE FRONT WILL
CONTINUE TO PUSH THROUGH THE MIDSOUTH ON FRIDAY INTO FRIDAY NIGHT
NUMEROUS TO WIDESPREAD SHOWERS WILL OCCUR ON FRIDAY AND FRIDAY
NIGHT ACROSS THE ENTIRE MIDSOUTH. COLDER AIR WILL USHER INTO THE
MIDSOUTH BEHIND THE FRONT. EXPECT HIGHS ON SATURDAY TO OCCUR IN
THE MORNING WITH NEAR STEADY TEMPERATURES OR SLIGHTLY FALLING
TEMPERATURES IN THE AFTERNOON. SOME LINGERING RAIN MAY OCCUR
ACROSS NORTH MISSISSIPPI SATURDAY MORNING OTHERWISE CONDITIONS
WILL BE DRY. EXPECT THE HIGHS ON SATURDAY MORNING TO BE IN THE THE
LOWER 40S TO LOWER 50S WITH TEMPERATURES DROPPING INTO UPPER 30S
TO UPPER 40S IN THE AFTERNOON.
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE MIDSOUTH ON SUNDAY BUT BY
SUNDAY NIGHT CLOUDS WILL BEGIN INCREASING AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM ALONG THE GULF COAST WHICH WOULD IMPACT THE
MIDSOUTH MONDAY THROUGH TUESDAY EVENING. WITH COLD AIR IN
PLACE...THIS IS A SYSTEM THAT BEARS WATCHING. PRECIPITATION WILL BEGIN TO
SPREAD INTO THE MIDSOUTH SUNDAY EVENING. EXPECT LOWS TO ACTUALLY OCCUR
IN THE EVENING. TEMPERATURES WILL LIKELY HOLD STEADY OR SLIGHTLY
RISE AFTER MIDNIGHT AS CLOUDS AHEAD OF THE SYSTEM SPREAD INTO THE
AREA. THE BIG QUESTION WILL BE WHAT THE TEMPERATURE IS AT A GIVEN
LOCATION WHEN THE PRECIPITATION STARTS. EXPECT MOST LOCATIONS TO
BE NEAR OR SLIGHTLY ABOVE FREEZING THUS PRECIPITATION WILL LIKELY
BE RAIN. HOWEVER WOULD NOT BE SURPRISED TO SEE AN INITIAL PERIOD
OF SLEET OCCUR DUE TO THE AMOUNT OF DRY AIR IN THE LOW LEVELS TO
OVERCOME BEFORE RAIN REACHES THE SURFACE. THE POSSIBLE EXCEPTION
MAY BE EXTREME NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND
EXTREME NORTHWEST TENNESSEE WHERE TEMPERATURES MAY BE SLIGHTLY
BELOW FREEZING THUS ALLOWING PRECIPITATION WOULD FALL AS SNOW BUT
AGAIN COULD INITIALLY BEGIN AS SLEET. EVEN IF THIS WOULD OCCUR THE
GROUND IS TOO WARM FOR ANY ACCUMULATION TO OCCUR. ANY SNOW THAT
WOULD BE OCCURRING MONDAY MORNING WOULD QUICKLY CHANGEOVER TO RAIN
AS TEMPERATURES RISE ABOVE FREEZING.
AS THE SFC LOW TRACKS EASTWARD ALONG THE GULF COAST...COLDER AIR
WILL BEGIN TO WRAP AROUND THE BACK SIDE OF THE LOW ON TUESDAY INTO
TUESDAY NIGHT. BOTH THE 00Z ECMWF AND THE 00Z GFS SHOW THAT
TEMPERATURES WILL BE FALLING ON TUESDAY. ONE THING THAT BEARS
WATCHING IS HOW LOW THE TEMPERATURES DROP TUESDAY AFTERNOON INTO
TUESDAY NIGHT AS THE POTENT UPPER LOW SWINGS INTO THE AREA BEHIND
THE DEPARTING SFC LOW. THE 00Z ECMWF IS COLDER THAN THE 00Z GFS
WHICH IF ECMWF SOLUTION WERE TO END UP BEING
CORRECT...PRECIPITATION COULD CHANGEOVER TO SNOW TUESDAY NIGHT.
HOWEVER A LOT OF TIMES...THE PRECIPITATION CUTS OFF BEFORE THE
REALLY COLD AIR GETS INTO THE AREA SO WILL JUST HAVE TO WAIT AND
SEE. COLD HIGH PRESSURE WILL BUILD INTO THE MIDSOUTH ON WEDNESDAY. THE
ONLY SURE BET FROM THE WEEKEND TIME PERIOD THROUGH THE END OF THE
FORECAST PERIOD IS THAT TEMPERATURES WILL BE WAY BELOW NORMAL.
HIGHS WILL RANGE FROM THE MID 30S TO THE UPPER 40S.
KRM
&&
.AVIATION...
06Z TAF CYCLE
SAME FORECAST THINKING THIS TAF PERIOD. MVFR CIGS STILL ADVANCING
NORTHWEST ACROSS ALABAMA WILL HAVE A SLIGHT DELAY IN REACHING TUP.
OTHERWISE VFR AT THE OTHER SITES. BY NOON LIGHT SHOWERS WILL BEGIN
TO AFFECT JBR...WITH ACTIVITY SLOWLY WORKING IT`S WAY SOUTH INTO MEM
AND MKL. LATER IN THE PERIOD CIGS WILL DEVELOP NEAR THE IFR/MVFR
THRESHOLD AT JBR AS A COLD FRONT PUSHES IN...OTHERWISE VFR CIGS
WILL CONTINUE ELSEWHERE THRU 22/06Z. THOUGH NOT LONG AFTER THIS
TIME FRAME CIGS AND VSBY WILL START DETERIORATING AT MEM AND MKL.
WINDS WILL BE SOUTHEAST THROUGH SOUTH AT MAINLY 5 TO 10 KTS.
JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 67 57 60 42 / 30 70 100 70
MKL 66 54 59 41 / 20 50 100 60
JBR 62 52 54 37 / 40 100 90 40
TUP 68 55 65 47 / 10 20 70 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
348 PM CST THU NOV 21 2013
.DISCUSSION...
THERE HAS BEEN PRETTY GOOD SHOWER COVERAGE TODAY ACROSS MAINLY THE WESTERN
PORTIONS OF THE AREA...WITH A COUPLE 1 TO 2 INCH RAINFALL ESTIMATED
AMOUNTS EMBEDDED IN THE ACTIVITY. THE HRRR HAS DONE A DECENT JOB ON
TODAY`S COVERAGE...AND IF IT HOLDS TRUE EXPECT TO SEE LESS COVERAGE
LATER THIS AFTERNOON AND THIS EVENING. THE STRONG COLD FRONT WITH ASSOCIATED
SHOWERS AND THUNDERSTORMS IS STILL ON SCHEDULE TO MOVE INTO OUR NORTHERN
COUNTIES CLOSE TO SUNRISE TOMORROW...THEN MOVE THROUGH THE REST OF THE
AREA DURING THE MORNING AND AFTERNOON HOURS. BREEZY NORTH WINDS AND
A SHARP TEMPERATURE DROP WILL FOLLOW THE FRONTAL PASSAGE...AND HIGHS
FOR THE DAY WILL LIKELY OCCUR IN THE EARLY MORNING HOURS UP NORTH AND
IN THE LATE MORNING OR EARLY AFTERNOON HOURS NEAR THE COAST. COLDER
TEMPERATURES AND LINGERING RAIN/SHOWER CHANCES ARE THEN SET TO PERSIST
THROUGH MUCH OF THE WEEKEND. INCREASING RAIN CHANCES ARE THEN EXPECTED
BEGINNING LATE SUNDAY AND ON INTO TUESDAY MORNING AS THE NEXT STORM
SYSTEM DEVELOPS AND MOVES ACROSS THE AREA. MODELS CONTINUE TO DIFFER
ON THE TIMING AND LOCATION OF THIS SYSTEM`S WESTERN GULF OF MEXICO SURFACE
LOW. IF THIS SYSTEM STAYS CLOSER TO THE COAST PER ECMWF...THERE COULD
BE A BRIEF WINDOW OF STRONG/SEVERE STORMS NEAR THE COAST ON MONDAY MORNING.
IF THE LOW IS FURTHER OFFSHORE PER GFS...MUCH OF THE AREA WILL JUST
SEE COLD RAIN. OVERALL...HAVE LOWERED ALL TEMPERATURES A COUPLE OF DEGREES
OVER THE WEEKEND AND INTO THE START OF NEXT WEEK. IF THIS TREND PERSISTS
AND LOTS OF PARAMETERS COME TOGETHER AND FALL INTO PLACE...WE MIGHT
NEED TO TAKE A CLOSER LOOK AT THE POSSIBILITY OF SOME FROZEN PRECIPITATION
CHANCES SUNDAY NIGHT THROUGH MONDAY MORNING ACROSS PORTIONS OF OUR FAR
NORTHERN COUNTIES. AT THIS TIME...FROZEN STUFF HAS MUCH BETTER CHANCES
OF OCCURRING WELL OFF TO OUR NORTHWEST AND WEST. EVERYTHING IS STILL
ON SCHEDULE TO CLEAR ON OUT OF THE AREA ON TUESDAY RESULTING IN MUCH
QUIETER WEATHER AS WE HEAD TOWARD THE THANKSGIVING HOLIDAY. AFTER
TOMORROW...THANKSGIVING DAY WILL PROBABLY BE THE FIRST DAY THE AREA
HAS HIGH TEMPERATURES COME BACK ABOVE 60 DEGREES.
42
&&
.MARINE...
MODERATE ONSHORE WINDS WILL CONTINUE THROUGH TONIGHT AS THE NEXT
COLD FRONT APPROACHES THE AREA. THERE IS AGAIN A CHANCE OF SEA FOG
TOMORROW MORNING. IT WILL BE A CHALLENGE THOUGH GIVEN HOW WATER
TEMPERATURES HAVE WARMED A BIT. DEWPOINTS ARE IN THE MID 70S
THOUGH. IF WINDS DUE BACK MORE EASTERLY NEAR THE COAST AS ECMWF
AND NAM HINT WOULD BE A MORE FAVORABLE SET UP FOR SEA FOG
DEVELOPMENT. RAP AND TEXAS TECH WRF ARE FASTEST WITH THE FRONT
HAVING IT ON PACE TO REACH THE COAST BY MID AFTERNOON. BEHIND THE
FRONT WINDS WILL BE ON THE INCREASE. WINDS WILL REACH ADVISORY
CRITERIA LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING. WINDS
SHOULD PEAK IN THE 20 TO 30KT RANGE SATURDAY AFTERNOON WITH GUSTS
APPROACHING GALE FORCE. SEAS IN OFFSHORE AREAS WILL BUILD TO
AROUND 9 TO 12 FEET. STRONG NORTHERLY WINDS WILL BEGIN TO TURN
NORTHEASTERLY SUNDAY BUT REMAIN STRONG.
MODELS CONTINUE TO ADVERTISE A COASTAL LOW DEVELOPING MONDAY AND
MOVING ACROSS THE WATERS TUESDAY. THE GFS IS SLOWER WITH THE COASTAL
LOW AND KEEPS IT FARTHER OFFSHORE. THE ECMWF IS FASTER WITH THE LOW
AND HUGS IT CLOSER TO THE COAST LINE. EASTERLY WINDS WILL HELP TO
ELEVATE TIDES AND WE WILL NEED TO MONITOR FOR ANY COASTAL FLOODING.
23
&&
.PREV DISCUSSION... /ISSUED 1130 AM CST THU NOV 21 2013/
DISCUSSION...
SEE AVIATION FOR 18Z TAF ISSUANCE.
AVIATION...
MANY THINGS IN CONSIDERATION WITH THE TAF PACKAGE THIS MORNING.
SHOWERS HAVE BEEN SCATTERED IN THE WESTERN HALF OF OUR CWA AND
BECOME MORE ISOLATED TOWARDS THE EAST. SHOWERS ARE FORMING OFF OF
ISENTROPIC LIFT OR UPGLIDE. MORE UPPER LEVEL CONVERGENCE EXISTS
OFF TO OUR EAST WHICH HAS LIMITED SHOWER PRODUCTION. IN GENERAL
TERMINALS IN OUR WESTERN AREAS HAVE THE BEST CHANCE OF SEEING RAIN
WITH TERMINALS TOWARDS THE EAST HAVING A LESSER CHANCE. THIS IS
SUPPORTED BY THE HRRR AND TEXAS TECH WRF MODELS. THE HRRR SEEMS TO
HAVE THE BEST HANDLE OF WHAT IS CURRENTLY GOING ON. HRRR HAS
PRECIP MOVING NORTHWARDS WITH MORE REDEVELOPMENT AT KCLL.
WIDESPREAD MVFR AND IFR CIGS TODAY WILL CONTINUE TO LOWER TOWARDS
IFR AND LIFR BY FRIDAY MORNING. THERE IS A SLIGHT CHANCE OF SOME
SEA FOG AS ECMWF AND NAM SHOWING EASTERLY WINDS TONIGHT. CHANCES
APPEARS LOW BUT GIVEN HIGH DEWPOINTS CAN`T RULE IT OUT.
A COLD FRONT CURRENTLY LOCATED IN THE TEXAS PANHANDLE WILL
CONTINUE TO PUSH SOUTHWARDS TODAY AND MAKE IT TO KCLL AROUND 5 TO
7AM. A LINE OF THUNDERSTORMS WILL BE WITH THE FRONT. BEST UPPER
LEVEL SUPPORT IS OFF TO OUR NORTH THOUGH SO LINE SHOULD BE
WEAKENING AS IT MOVES SOUTHWARDS. THE FRONT WILL MOST LIKELY BE
AT THE COAST AROUND 12 TO 3PM. THE EXACT TIMING WILL BE TRICKY
THOUGH AS FRONTS GENERALLY SLOW DOWN DURING THE DAY. WITH THIS
BEING SAID MODELS ARE SLOW GIVEN THE CURRENT FRONTAL POSITION. THE
TEXAS TECH WRF IS THE FASTEST BRINGING THE FRONT TO THE COAST
AROUND 1PM. BEHIND THE FRONT LIGHT RAIN AND SOME WIND WITH IFR TO
LIFR CONDITIONS CAN BE EXPECTED. 23
CLIMATE...
THE RECORD HIGH MINIMUM TEMPERATURE FOR COLLEGE STATION (CLL) TODAY
IS 67 DEGREES SET IN 1982. THE LOW TEMPERATURE THIS MORNING AT CLL
WAS 67 DEGREES. IF CLL`S TEMPERATURE DOES NOT FALL BELOW 67 BEFORE
MIDNIGHT...TODAY`S RECORD HIGH MINIMUM TEMPERATURE WILL BE TIED. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 56 56 38 45 36 / 70 70 50 40 20
HOUSTON (IAH) 69 70 43 51 41 / 50 70 60 50 20
GALVESTON (GLS) 69 75 50 55 45 / 40 70 60 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1205 PM CST THU NOV 21 2013
.AVIATION...
FOR THE 18Z TAFS...A DIFFICULT FORECAST FOR THE NEXT 24 HOURS. NORTH
WINDS OF 20-30KTS ARE EXPECTED THROUGH THE PERIOD. IFR CEILINGS AT
KAMA AND KDHT MAY FLIRT WITH LIFR HEIGHTS AT TIMES TODAY...THEN ARE
EXPECTED TO IMPROVE TO MVFR BY AROUND 03Z. CEILINGS AT ALL 3 TAF SITES
SHOULD THEN DEGRADE TO IFR AGAIN BETWEEN 09Z AND 12Z FRIDAY. PERIODS
OF LIGHT FREEZING DRIZZLE AND FREEZING MIST OR FOG WILL GIVE WAY TO
FREEZING DRIZZLE AND SNOW GRAINS OR FLURRIES BETWEEN 03Z AND 06Z
FRIDAY. THE LOWEST VISIBILITIES WILL GENERALLY OCCUR WITH HEAVIER
PERIODS OF PRECIPITATION. CONFIDENCE IN THE EXACT TIMING OF
PRECIPITATION REMAINS LOW...THOUGH POOR CONDITIONS WILL PERSIST PAST
THE END OF THIS TAF PERIOD.
NF
&&
.PREV DISCUSSION... /ISSUED 1148 AM CST THU NOV 21 2013/
UPDATE...
ARCTIC COLD FRONT HAS PLOWED THROUGH MOST OF THE AREA THIS
MORNING...AND IS CURRENTLY PUSHING THROUGH THE FAR SOUTHEAST TX
PANHANDLE. TEMPERATURES AT 11 AM RANGING FROM THE UPPER 20S IN THE
WESTERN OK PANHANDLE TO THE UPPER 60S IN THE SOUTHEAST TX
PANHANDLE...AN IMPRESSIVE 40 DEGREE RANGE. STRATUS HAS SPILLED SOUTH
BEHIND THE FRONT IN THE STRONG COLD AIR ADVECTION...WITH SOME POST-
FRONTAL FOG AS WELL AND A FEW REPORTS OF SOME MIST/LIGHT DRIZZLE. FOG
HAS BEEN MOST PREVALENT IMMEDIATELY BEHIND THE FRONT...WITH SOME LOW-
LEVEL DRIER AIR FILTERING IN FROM THE NORTH ALLOWING FOR VSBYS TO COME
UP SOME FARTHER NORTH OF THE FRONT.
FOR THE REST OF THIS AFTERNOON...TEMPS WILL CONTINUE TO FALL INTO THE
20S AND 30S AS STRONG COLD AIR ADVECTION PERSISTS. ANY PRECIPITATION
THROUGH LATE THIS AFTERNOON IS EXPECTED TO BE VERY LIGHT. MID-LEVELS
STAY DRY THROUGH THIS TIME...SO ANY LIGHT PRECIPITATION WILL LIKELY
BE IN THE FORM OF DRIZZLE OR FREEZING DRIZZLE...WITH THE BETTER
CHANCES OF THIS ACROSS THE NORTHERN HALF OF THE AREA WHERE THE LOW-
LEVEL MOIST LAYER WILL DEEPEN SOONER. FARTHER SOUTH...THINK SOME
FOG/FREEZING FOG WILL BE THE MORE LIKELY SCENARIO FOR THE REST OF THE
AFTERNOON UNTIL THE MOIST LAYER CAN DEEPEN FURTHER. FORECAST
SOUNDINGS SHOW TEMPERATURES IN THE LOW-LEVEL MOIST LAYER POSSIBLY
DIPPING TO AROUND -6C OR LOWER ACROSS THE OK PANHANDLE LATE THIS
AFTERNOON...WHICH MAY BE COLD ENOUGH TO SUPPORT SOME ICE CRYSTAL
GROWTH AND RESULTANT VERY LIGHT SNOW/FLURRIES. GIVEN THE LIGHT
NATURE OF ANY PRECIP THROUGH THE AFTERNOON AND WARM GROUND TEMPS TO
START THE DAY...EXPECT ANY IMPACTS TO BE FAIRLY MINIMAL THROUGH THIS
AFTERNOON AND THUS WILL KEEP THE WINTER WEATHER ADVISORY START TIME
AT 6 PM THIS EVENING.
KB
PREV DISCUSSION... /ISSUED 523 AM CST THU NOV 21 2013/
DISCUSSION...
MULTIPLE CHANCES TO SEE A WINTRY MIX OF PRECIPITATION STILL EXPECTED
FROM TODAY THROUGH EARLY NEXT WEEK.
THE ARCTIC COLD FRONT CONTINUES TO SURGE SOUTHWARD ABOUT 3 HOURS
AHEAD OF SCHEDULE FROM YESTERDAY. THE MODELS WITH THE CLOSEST
DEPICTION OF THE FASTER FRONTAL TIMING HAS BEEN THE RUC AND THE 00Z
GFS. WITH A BLEND OF THESE TWO MODELS THE FRONT IS EXPECTED TO BE
MOSTLY THROUGH THE PANHANDLES BY NOON TODAY. THIS WILL CAUSE HIGH
TEMPERATURES TO BE COLDER THAN PREVIOUSLY ADVERTISED. THE MOST
NOTICEABLE CHANCE IN TEMPERATURE FROM YESTERDAY WILL BE IN THE
OKLAHOMA PANHANDLE WHICH REACHED INTO THE 60S BUT WILL STRUGGLE TO
REACH THE 40 DEGREE MARK TODAY.
THE FORECAST STILL SHOWS DECENT CHANCES FOR THE TEXAS AND OKLAHOMA
PANHANDLE TO SEE SOME FORM OF WINTRY PRECIPITATION BETWEEN NOW AND
SATURDAY MORNING. THE QUESTION WILL BE WHERE CAN WE GET ENOUGH
MOISTURE IN THE DENDRITIC SNOW GROWTH ZONE TO MAKE A SOLID TRANSITION
TO MOSTLY OR ALL SNOW. THE BEST AREA FOR THIS TO HAPPEN IS EXPECTED
TO BE NORTH OF A DALHART TO ELKHART LINE. THE REMAINDER OF THE AREA
WILL HAVE A CHANCE TO SEE A FEW FLAKES BUT FREEZING DRIZZLE AND OR
FREEZING RAIN SEEMS A MORE LIKELY FORECAST. WHILE WE ARE EXPECTING
ANY WINTRY PRECIPITATION ACCUMULATIONS TO REMAIN LIGHT LOCATIONS NORTH
OF THE DALHART TO ELKHART LINE COULD SEE BETWEEN 1 TO 3 INCHES OF
SNOW WHILE THERE WILL BE A CHANCE FOR LIGHT ICE ACCUMULATIONS ACROSS
ELEVATED SURFACES ACROSS THE PANHANDLES.
SATURDAY REMAINS THE LULL DAY BEFORE A CLOSED UPPER LEVEL LOW EJECTS
FROM THE DESERT SOUTHWEST. AS THIS LOW MOVES ACROSS THE PANHANDLES WE
COULD SEE ANOTHER ROUND OF WINTRY PRECIPITATION WHICH MAY NEED AN
ADVISORY FOR THE SATURDAY NIGHT AND SUNDAY TIME FRAME. BY MONDAY DRIER
CONDITIONS BEGIN TO SETTLE IN FOR THE LATER HALF OF THIS FORECAST
CYCLE.
FIRE WEATHER...
NEITHER ELEVATED NOR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
FOR THE NEXT SEVEN DAYS.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
06/02
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1148 AM CST THU NOV 21 2013
.UPDATE...
ARCTIC COLD FRONT HAS PLOWED THROUGH MOST OF THE AREA THIS
MORNING...AND IS CURRENTLY PUSHING THROUGH THE FAR SOUTHEAST TX
PANHANDLE. TEMPERATURES AT 11 AM RANGING FROM THE UPPER 20S IN THE
WESTERN OK PANHANDLE TO THE UPPER 60S IN THE SOUTHEAST TX
PANHANDLE...AN IMPRESSIVE 40 DEGREE RANGE. STRATUS HAS SPILLED SOUTH
BEHIND THE FRONT IN THE STRONG COLD AIR ADVECTION...WITH SOME POST-
FRONTAL FOG AS WELL AND A FEW REPORTS OF SOME MIST/LIGHT DRIZZLE. FOG
HAS BEEN MOST PREVALENT IMMEDIATELY BEHIND THE FRONT...WITH SOME LOW-
LEVEL DRIER AIR FILTERING IN FROM THE NORTH ALLOWING FOR VSBYS TO COME
UP SOME FARTHER NORTH OF THE FRONT.
FOR THE REST OF THIS AFTERNOON...TEMPS WILL CONTINUE TO FALL INTO THE
20S AND 30S AS STRONG COLD AIR ADVECTION PERSISTS. ANY PRECIPITATION
THROUGH LATE THIS AFTERNOON IS EXPECTED TO BE VERY LIGHT. MID-LEVELS
STAY DRY THROUGH THIS TIME...SO ANY LIGHT PRECIPITATION WILL LIKELY
BE IN THE FORM OF DRIZZLE OR FREEZING DRIZZLE...WITH THE BETTER
CHANCES OF THIS ACROSS THE NORTHERN HALF OF THE AREA WHERE THE LOW-
LEVEL MOIST LAYER WILL DEEPEN SOONER. FARTHER SOUTH...THINK SOME
FOG/FREEZING FOG WILL BE THE MORE LIKELY SCENARIO FOR THE REST OF THE
AFTERNOON UNTIL THE MOIST LAYER CAN DEEPEN FURTHER. FORECAST
SOUNDINGS SHOW TEMPERATURES IN THE LOW-LEVEL MOIST LAYER POSSIBLY
DIPPING TO AROUND -6C OR LOWER ACROSS THE OK PANHANDLE LATE THIS
AFTERNOON...WHICH MAY BE COLD ENOUGH TO SUPPORT SOME ICE CRYSTAL
GROWTH AND RESULTANT VERY LIGHT SNOW/FLURRIES. GIVEN THE LIGHT
NATURE OF ANY PRECIP THROUGH THE AFTERNOON AND WARM GROUND TEMPS TO
START THE DAY...EXPECT ANY IMPACTS TO BE FAIRLY MINIMAL THROUGH THIS
AFTERNOON AND THUS WILL KEEP THE WINTER WEATHER ADVISORY START TIME
AT 6 PM THIS EVENING.
KB
&&
.PREV DISCUSSION... /ISSUED 523 AM CST THU NOV 21 2013/
DISCUSSION...
MULTIPLE CHANCES TO SEE A WINTRY MIX OF PRECIPITATION STILL EXPECTED
FROM TODAY THROUGH EARLY NEXT WEEK.
THE ARCTIC COLD FRONT CONTINUES TO SURGE SOUTHWARD ABOUT 3 HOURS
AHEAD OF SCHEDULE FROM YESTERDAY. THE MODELS WITH THE CLOSEST
DEPICTION OF THE FASTER FRONTAL TIMING HAS BEEN THE RUC AND THE 00Z
GFS. WITH A BLEND OF THESE TWO MODELS THE FRONT IS EXPECTED TO BE
MOSTLY THROUGH THE PANHANDLES BY NOON TODAY. THIS WILL CAUSE HIGH
TEMPERATURES TO BE COLDER THAN PREVIOUSLY ADVERTISED. THE MOST
NOTICEABLE CHANCE IN TEMPERATURE FROM YESTERDAY WILL BE IN THE
OKLAHOMA PANHANDLE WHICH REACHED INTO THE 60S BUT WILL STRUGGLE TO
REACH THE 40 DEGREE MARK TODAY.
THE FORECAST STILL SHOWS DECENT CHANCES FOR THE TEXAS AND OKLAHOMA
PANHANDLE TO SEE SOME FORM OF WINTRY PRECIPITATION BETWEEN NOW AND
SATURDAY MORNING. THE QUESTION WILL BE WHERE CAN WE GET ENOUGH
MOISTURE IN THE DENDRITIC SNOW GROWTH ZONE TO MAKE A SOLID TRANSITION
TO MOSTLY OR ALL SNOW. THE BEST AREA FOR THIS TO HAPPEN IS EXPECTED
TO BE NORTH OF A DALHART TO ELKHART LINE. THE REMAINDER OF THE AREA
WILL HAVE A CHANCE TO SEE A FEW FLAKES BUT FREEZING DRIZZLE AND OR
FREEZING RAIN SEEMS A MORE LIKELY FORECAST. WHILE WE ARE EXPECTING
ANY WINTRY PRECIPITATION ACCUMULATIONS TO REMAIN LIGHT LOCATIONS NORTH
OF THE DALHART TO ELKHART LINE COULD SEE BETWEEN 1 TO 3 INCHES OF
SNOW WHILE THERE WILL BE A CHANCE FOR LIGHT ICE ACCUMULATIONS ACROSS
ELEVATED SURFACES ACROSS THE PANHANDLES.
SATURDAY REMAINS THE LULL DAY BEFORE A CLOSED UPPER LEVEL LOW EJECTS
FROM THE DESERT SOUTHWEST. AS THIS LOW MOVES ACROSS THE PANHANDLES WE
COULD SEE ANOTHER ROUND OF WINTRY PRECIPITATION WHICH MAY NEED AN
ADVISORY FOR THE SATURDAY NIGHT AND SUNDAY TIME FRAME. BY MONDAY DRIER
CONDITIONS BEGIN TO SETTLE IN FOR THE LATER HALF OF THIS FORECAST
CYCLE.
FIRE WEATHER...
NEITHER ELEVATED NOR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
FOR THE NEXT SEVEN DAYS.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
08/02
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1130 AM CST THU NOV 21 2013
.DISCUSSION...
SEE AVIATION FOR 18Z TAF ISSUANCE.
&&
.AVIATION...
MANY THINGS IN CONSIDERATION WITH THE TAF PACKAGE THIS MORNING.
SHOWERS HAVE BEEN SCATTERED IN THE WESTERN HALF OF OUR CWA AND
BECOME MORE ISOLATED TOWARDS THE EAST. SHOWERS ARE FORMING OFF OF
ISENTROPIC LIFT OR UPGLIDE. MORE UPPER LEVEL CONVERGENCE EXISTS
OFF TO OUR EAST WHICH HAS LIMITED SHOWER PRODUCTION. IN GENERAL
TERMINALS IN OUR WESTERN AREAS HAVE THE BEST CHANCE OF SEEING RAIN
WITH TERMINALS TOWARDS THE EAST HAVING A LESSER CHANCE. THIS IS
SUPPORTED BY THE HRRR AND TEXAS TECH WRF MODELS. THE HRRR SEEMS TO
HAVE THE BEST HANDLE OF WHAT IS CURRENTLY GOING ON. HRRR HAS
PRECIP MOVING NORTHWARDS WITH MORE REDEVELOPMENT AT KCLL.
WIDESPREAD MVFR AND IFR CIGS TODAY WILL CONTINUE TO LOWER TOWARDS
IFR AND LIFR BY FRIDAY MORNING. THERE IS A SLIGHT CHANCE OF SOME
SEA FOG AS ECMWF AND NAM SHOWING EASTERLY WINDS TONIGHT. CHANCES
APPEARS LOW BUT GIVEN HIGH DEWPOINTS CAN`T RULE IT OUT.
A COLD FRONT CURRENTLY LOCATED IN THE TEXAS PANHANDLE WILL
CONTINUE TO PUSH SOUTHWARDS TODAY AND MAKE IT TO KCLL AROUND 5 TO
7AM. A LINE OF THUNDERSTORMS WILL BE WITH THE FRONT. BEST UPPER
LEVEL SUPPORT IS OFF TO OUR NORTH THOUGH SO LINE SHOULD BE
WEAKENING AS IT MOVES SOUTHWARDS. THE FRONT WILL MOST LIKELY BE
AT THE COAST AROUND 12 TO 3PM. THE EXACT TIMING WILL BE TRICKY
THOUGH AS FRONTS GENERALLY SLOW DOWN DURING THE DAY. WITH THIS
BEING SAID MODELS ARE SLOW GIVEN THE CURRENT FRONTAL POSITION. THE
TEXAS TECH WRF IS THE FASTEST BRINGING THE FRONT TO THE COAST
AROUND 1PM. BEHIND THE FRONT LIGHT RAIN AND SOME WIND WITH IFR TO
LIFR CONDITIONS CAN BE EXPECTED. 23
&&
.PREV DISCUSSION... /ISSUED 954 AM CST THU NOV 21 2013/
DISCUSSION...
MADE SOME MINOR CHANGES TO THE FORECAST...WITH SOME UPWARD ADJUSTMENTS
TO DEW POINTS (READINGS ALREADY IN THE 70S ALONG AND SOUTH OF A LINE
FROM COLLEGE STATION TO HOUSTON TO GALVESTON) AND SOME TWEAKS TO TODAY`S
POPS. OTHER THAN THAT...FORECAST LOOKS TO BE ON TRACK. THE STRONG COLD
FRONT IS CURRENTLY MOVING SOUTHWARD INTO THE NORTHERN OKLAHOMA AREA...AND
THIS IS THE BOUNDARY THAT WILL BE MOVING THROUGH OUR AREA DURING THE
DAY TOMORROW. STILL EXPECTING A SHARP TEMPERATURE DROP TO OCCUR BEHIND
THE FRONT WITH READINGS LIKELY FALLING INTO THE 40S AND 50S NORTH AND
CENTRAL BEFORE SUNSET. THERE WILL ALSO BE A GOOD SHOT OF RAINFALL WITH
THE FRONT. THE WEEKEND LOOKS COLD...AND NO REAL WARMUP IS ANTICIPATED
UNTIL AROUND THE END OF NEXT WEEK. THANKSGIVING IS STILL LOOKING DRY.
42
CLIMATE...
THE RECORD HIGH MINIMUM TEMPERATURE FOR COLLEGE STATION (CLL) TODAY
IS 67 DEGREES SET IN 1982. THE LOW TEMPERATURE THIS MORNING AT CLL
WAS 67 DEGREES. IF CLL`S TEMPERATURE DOES NOT FALL BELOW 67 BEFORE
MIDNIGHT...TODAY`S RECORD HIGH MINIMUM TEMPERATURE WILL BE TIED. 42
PREV DISCUSSION... /ISSUED 606 AM CST THU NOV 21 2013/
DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION...
AVIATION...
GULF MOISTURE CONTINUES TO INCREASE OVER SE TX THIS MORNING WITH
SOME SHOWER ACTIVITY. LIFR/IFR TO MVFR CIGS HAVE BEEN WIDESPREAD
THIS MORNING. MOST TERMINALS ARE AT IFR CIGS WITH MAINLY THE
HOUSTON TERMINALS AND KGLS BEING THE EXCEPTIONS. EXPECT CIGS TO
IMPROVE LATE THIS MORNING BUT WRF/HRRR HINT AT INCREASE IN
COVERAGE OF SHOWERS. COULD GET SOME MVFR/VFR CIGS THIS AFTERNOON
BEFORE CIGS CRASH BACK TO IFR OR EVEN LIFR FOR THE OVERNIGHT.
MODELS SEEM TO BE SPEEDING UP THE FRONT AS EXPECTED FOR EARLY
FRIDAY. FRONT MAINLY IMPACT KCLL BEFORE 12Z FRI AND THEN BEFORE
18Z FRI IN THE 30HR KIAH TAF. THE UPCOMING 18Z TAFS WILL REFLECT
THE FRONTAL PASSAGE AND EXPECTED TSRA.
KCLL/KUTS/KCXO...LOOKS LIKE IFR CIGS THROUGH THE MORNING AND
AFTERNOON AND IMPROVING LATE. SHOWERS POSSIBLE DURING THIS TIME AS
WELL. THINK THERE COULD BE A BREAK IN ACTIVITY FROM 20-21Z THROUGH
01Z FRI. CIGS WILL THEN BEGIN TO CRASH. CONVECTION IMPACT KCLL
AFTER 05Z WITH TSRA LIKELY AT TERMINAL BEFORE 12Z FRI WITH THE
FRONT.
KIAH/KHOU/KSGR...MAINLY MVFR CIGS THIS MORNING INTO THE AFTERNOON
WITH SHOWERS DEVELOPING. EXPECT THERE TO BE SOMEWHAT OF A BREAK IN
THE LATE AFTERNOON INTO THE EVENING BEFORE CIGS GO BACK DOWN TO
MVFR/IFR LEVELS. MAY SEEN LIFR CIGS WITH WINDS DECREASING
OVERNIGHT AS COLD FRONT APPROACHES. FRONT SHOULD REACH KIAH AROUND
15-18Z FRI WITH TSRA LIKELY.
KLBX/KGLS...AGAIN MVFR/IFR CIGS BUT LOOKS LIKE LESS CLOUD COVER AT
GLS FOR NOW. MAY GET SOME SHOWER ACTIVITY INCREASE LIKE MOST
INLAND TERMINALS. DO THINK MVFR/IFR CIGS LIKELY IN THE EVENING AND
PERHAPS PERIODS OF LIFR CIGS OVERNIGHT. WILL NEED TO WATCH KGLS
FOR SEA FOG FORMATION AND VSBY BECOMING MORE RESTRICTED THAN 4SM.
39
PREV DISCUSSION... /ISSUED 416 AM CST THU NOV 21 2013/
DISCUSSION...
A COUPLE OF RAINY PERIODS WILL AFFECT SE TX OVER THE NEXT FIVE
DAYS. A COLD FRONT WHICH WAS MOVING SOUTHWARD ACROSS THE NORTHERN
PLAINS EARLY THIS MORNING WILL PUSH INTO THE STATE TONIGHT AND
ACROSS SE TX ON FRIDAY. ISENTROPIC LIFT WILL KEEP CLOUDS AND RAIN
CHANCES OVERHEAD THROUGH SATURDAY WITH A BRIEF BREAK FROM THE
RAINY CONDITIONS SATURDAY NIGHT INTO SUNDAY. HOWEVER...THE SECOND
RAIN EVENT WILL OCCUR SUNDAY NIGHT THROUGH TUESDAY AS A STRONG
UPPER LEVEL LOW MOVES ACROSS THE STATE AND A SURFACE LOW MOVES UP
THE COAST.
A FAIRLY DEEP MOISTURE LAYER WILL BE FOCUSED BY WARM AIR ADVECTION
TO HELP BRING SCATTERED RAIN SHOWERS TODAY. THERE IS A SEA FOG
THREAT TONIGHT -- SEE THE MARINE SECTION BELOW FOR MORE DETAILS.
EXPECT WIDESPREAD RAIN AND ISOLATED THUNDERSTORMS TO BEGIN OUT
WEST LATE TONIGHT AND AREA WIDE ON FRIDAY AS THE COLD FRONT MOVES
THROUGH. MODEL PW/S GET AS HIGH AS 1.8 INCHES...ABOUT 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. GOING FOR JUST
ISOLATED THUNDER GIVEN THE LACK UP UPPER LEVEL SUPPORT. BOTH THE
GFS AND ECMWF ADVERTISE A BREAK ON SATURDAY NIGHT AND SUNDAY.
SUNDAY NIGHT AND EARLY MONDAY MORNING WILL THEN LIKELY BE THE
COLDEST NIGHT OF THE PERIOD AS TEMPERATURES FALL INTO THE 30S OVER
MOST OF THE INLAND COUNTIES...WITH MID 30S EXPECTED NORTH OF A
LINE FROM BRENHAM TO LIBERTY.
CHILLY AND RAINY CONDITIONS ARE LIKELY ON MONDAY AS THE SURFACE
LOW GETS ORGANIZED OFF BROWNSVILLE AND MOVES UP THE COAST. THE GFS
AND ECMWF DIFFER A BIT ON THE TIMING AND LENGTH OF THE EVENT...BUT
THINK THAT THE BULK OF THE RAINFALL WILL PUSH EAST OF THE STATE
BY TUESDAY. KEPT A CHANCE OF RAIN ON TUESDAY WITH THE UPPER TROUGH
PUSHING EASTWARD OVERHEAD.
MARINE...
SFC LOW OVER THE PLAINS WILL KEEP SE WINDS IN PLACE TODAY AT
MODERATE LEVELS. SEAS SHOULD BE SLOWLY SUBSIDING BUT SHOULD REMAIN
AT MODERATE LEVELS. WINDS WILL CONTINUE TO DECREASE THROUGH THE
EVENING HOURS INTO FRIDAY. STRONG COLD FRONT IS STILL ON TRACK TO
PUSH THROUGH THE COASTAL WATERS FRI NIGHT INTO SATURDAY. LIKELY
HAVE ADVISORY CONDITIONS WITH GUSTS TO NEAR GALE FORCE. THERE MAY
BE AN COUPLE OF HOURS WITH WIND GUSTS TO GALE FORCE BUT NOT ENOUGH
TO NEED A GALE WATCH/WARNING AT THIS TIME. LIKELY HAVE 20 TO 30KT
WINDS WITH GUSTS TO 35KTS. SEAS IN OFFSHORE AREAS WILL BUILD TO
AROUND 8 TO 11 FEET BY SAT AFTERNOON. STRONG NORTHERLY WINDS WILL
PERSIST INTO SUNDAY BUT TURN MORE TO THE NORTHEAST.
MODELS BECOMING A MORE CONSISTENT WITH THE DEVELOPMENT OF A
COASTAL LOW SUN NIGHT INTO MON AS A STRONG UPPER LEVEL SYSTEM
MOVES THROUGH TX. COASTAL LOW SHOULD REMAIN OFF THE COAST BUT
SUPPORT STRONG EASTERLY WINDS. THIS SHOULD ELEVATE TIDES AND WILL
NEED TO MONITOR FOR ANY COASTAL FLOODING. AGAIN THIS IS STILL FOR
EARLY NEXT WEEK AND NEEDS TO BE WATCHED CLOSELY FOR ANY CHANGES.
SEA FOG POTENTIAL...ANOTHER CHALLENGING FORECAST FOR SEA FOG. THE
PROBLEMS FOR SEA FOG FORMATION SEEM TO BE SLIGHTLY HIGHER WATER
TEMPS THAN THE PREVIOUS SEA FOG EVENT AND NOT QUITE AS DEEP
MOISTURE. THAT SAID...SOME OBS IN THE GULF SHOW LOW/MID 70
DEWPOINT TEMPS WHICH SHOULD ADVECT TOWARDS THE COAST. THINK BEST
CHANCES FOR FOG FORMATION WILL BE LATE THIS EVENING THROUGH FRIDAY
MORNING AHEAD OF THE FRONT. FOG MAY THICKEN AGAIN FRIDAY EVENING
JUST AHEAD OF THE FRONT BUT ONCE THE FRONT PUSHES THROUGH...THREAT
FOR FOG WILL END.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 60 61 40 49 / 40 60 80 40 30
HOUSTON (IAH) 79 69 69 45 55 / 40 50 70 60 40
GALVESTON (GLS) 77 69 71 52 59 / 40 30 70 60 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
549 AM CST THU NOV 21 2013
.AVIATION...
LOW STRATUS AND LIGHT FOG ARE EXPECTED TO HANG ON IN THE VICINITY
OF KLBB THROUGH 14 OR 15 UTC. OTHERWISE....VFR CONDITIONS ARE
EXPECTED AT BOTH TERMINALS WITH WESTERLY WINDS THROUGH MIDDAY.
THEN...A STRONG COLD FRONT WILL SWEEP THROUGH THE AREA...BRINGING A
WIND SHIFT TO THE NORTH...PERHAPS SOME BLOWING DUST ALONG THE FRONT...AND
SUSTAINED WIND SPEEDS RAMPING UP TO ABOUT 25 KTS BY 23 UTC. LOW
STRATUS IS EXPECTED TO FILL BACK IN TONIGHT WITH A RETURN TO IFR
CONDITIONS AND THERE WILL ALSO BE A CHANCE OF DRIZZLE...FREEZING
DRIZZLE AND SLEET OVERNIGHT...WITH VERY LIGHT ACCUMULATIONS.
&&
.PREV DISCUSSION... /ISSUED 409 AM CST THU NOV 21 2013/
SHORT TERM...
A STRONG COLD FRONT WAS BARRELING SOUTH THIS MORNING THROUGH THE
HIGH PLAINS. AT 3 AM CST THE LEADING EDGE OF THE FRONT WAS LOCATED
NEAR PUEBLO COLORADO TO GREAT BEND KANSAS. NORTHERLY WINDS OF 25 TO
35 MPH WERE BLOWING BEHIND THE FRONT WITH 6 TO 8 MB/6 HR PRESSURE
RISES AND TEMPERATURES WERE QUICKLY DROPPING INTO THE SINGLE DIGITS
ACROSS MUCH OF WYOMING. THE FRONT/S ADVANCE WAS A COUPLE HRS AHEAD OF
NAM AND GFS GUIDANCE...NOT UNUSUAL...WHILE THE HRRR AND RAP
SHORT-RANGE PROGS WERE MORE IN LINE WITH THE FRONT/S ACTUAL
PROGRESS. THE RAP SUGGESTS A WEAK NW-N WIND SHIFT WILL WORK THROUGH
THE CWFA THIS MORNING. THIS SHOULD HELP SCOUR OUT THE LOW STRATUS AND
FOG FROM NORTH TO SOUTH EARLY TO MID MORNING. THE ACTUAL FRONT COULD
BE ON THE DOORSTEP OF OUR NORTHERN COUNTIES BY ABOUT NOON...AND
CLEAR OUR SRN COUNTIES BY 5 PM OR SO. HIGH TEMPERATURES MAY BE
REACHED AROUND NOON ACROSS THE NORTH...WITH TEMPS FALLING IN THE
AFTERNOON...THEN FALLING QUICKLY FOR ALL AREAS IN THE EVENING AS THE
CAA REALLY TAKES HOLD. WE/VE COOLED TEMPS DOWN QUITE A BIT ACROSS
THE NORTH WHILE WE STILL EXPECT SOUTHERN ZONES TO REACH THE UPPER
60S AND LOW 70S BEFORE THE FRONT HITS.
IT APPEARS THAT THE PRE-FRONTAL WIND SHIFT AND EARLIER FROPA WILL
REALLY LIMIT T-STORM CHANCES THIS AFTERNOON AND EVENING...LIKELY
CONFINING THE RISK AREA TO THE EASTERN AND SOUTHERN ROLLING
PLAINS...AND WE/VE TRIMMED POPS BACK ACCORDINGLY. STRONG LIFT ALONG
THE FRONT MAY LEAD TO THE DEVELOPMENT OF A THIN LINE OF STORMS AS
SUGGESTED BY THE TTU-WRF. SOME ISOLD STRONGER CORES WITH SMALL HAIL
ARE POSSIBLE...BUT SEVERE POTENTIAL LOOKS SMALL.
THEN THE MAIN FOCUS WILL QUICKLY SHIFT TO TIMING THE CHANGEOVER TO
FREEZING PRECIP FRIDAY EVENING AND WHAT ARE THE POTENTIAL
ACCUMULATIONS. FORECAST TEMP PROFILES SHOW THAT THE SWITCH COULD
BEGIN AS EARLY AS 8 OR 9 PM ACROSS THE FAR SRN PANHANDLE WITH TEMPS
LIKELY COLD ENOUGH TO SUPPORT FROZEN PRECIP ACROSS THE ENTIRE CWA
ASIDE FROM THE SOUTHERN ROLLING PLAINS BY AROUND MIDNIGHT.
HOWEVER...FRIDAY EVENING...FORECAST SOUNDINGS DO NOT SHOW DEEP
SATURATION THUS WE ANTICIPATE THAT PRECIP INITIALLY IN THE WAKE OF
THE FRONT WILL START OUT AS DRIZZLE...THEN MIX AND SWITCH TO
FREEZING DRIZZLE. DEEPER SATURATION AND BETTER MID-LVL LIFT IS
PROGGED TO ARRIVE AFTER MIDNIGHT AND DURING THE MIDNIGHT TO 6 AM
PERIOD WE SHOULD SEE BETTER CHANCES AT SOME SLEET AND FREEZING RAIN.
SLEET WILL ALSO BE MORE LIKELY ACROSS THE COLDER AREAS OF THE NW
SPLNS AND SW TX PANHANDLE...WITH FREEZING DRIZZLE/RAIN DOMINANT IN
THE ROLLING PLAINS. FORECAST ICE/SLEET PRECIP ACCUMULATIONS LOOK
MINIMAL BEFORE MIDNIGHT...THEN INCREASE SOMEWHAT BY 6 AM...ALTHOUGH
REMAINING LIGHT. THE INITIAL ACCUMULATIONS WILL ALSO /HOPEFULLY/ BE
MITIGATED SOMEWHAT BY THE RELATIVELY WARM GROUND. THUS...AT THIS
TIME WE WILL NOT HOIST ANY WINTER WEATHER ADVISORIES...ALTHOUGH IT
IS NOT OUT OF THE QUESTION THAT ONE MAY BE NEEDED AFTER MIDNIGHT.
ALSO OF NOTE WILL BE THE GUSTY NORTH WINDS AND THE COLD WIND CHILL
TEMPS. BOTH OF THESE ARE EXPECTED TO FALL SHORT OF ADVISORY
CONDITIONS BUT WILL CONTRIBUTE TO AN OVERALL WINTRY ATMOSPHERE.
LONG TERM...
A COMPLEX FORECAST CONTINUES ON IN THE LONG TERM FORECAST THROUGH
AT LEAST EARLY NEXT WEEK. THE MAIN ISSUE WILL BE THE PRECIPITATION
TYPE AND INTENSITY. BEST CHANCES OF PRECIPITATION WILL BE
MAINTAINED DURING THE DAY ON FRIDAY WITH LESSER CHANCES ON
SATURDAY. LIFT FROM WARM AIR ADVECTION ABOVE THE COLD AIR DOME
WILL GENERALLY BE WEAK. FLOW ON THE MOIST ISENTROPIC SURFACES WILL
BE ONLY 5-10 KNOTS THROUGH THE DURATION OF THE EVENT.
HOWEVER...SOME STRONGER FLOW MAY BE POSSIBLE NEAR THE TEXAS/NEW
MEXICO STATE LINE. A MID LEVEL DRY LAYER AROUND 700MB WILL ENTER
THE AREA ON FRIDAY WHICH ADDS SOME ADDITIONAL COMPLEXITY TO THE
PRECIPITATION TYPE. AS COLD AS THE TEMPERATURE WILL BE AT THE
SURFACE...WOULD MOSTLY EXPECT EITHER FREEZING DRIZZLE OR SLEET.
THE WARM LAYER ALOFT WILL START OUT ON FRIDAY AROUND AN ASTOUNDING
7-9C BUT SLOWLY WEAKEN THROUGH THE EVENT. THE SUBFREEZING LAYER AT
THE SURFACE ON FRIDAY WILL BE AROUND 3KFT ALLOWING FOR POSSIBLE
SLEET TO DEVELOP. WITH THE LIFT GENERALLY BEING WEAK...WOULD
ANTICIPATE MORE DRIZZLE THAN RAINFALL. THERE MAY BE A SLIGHT LULL
IN PRECIPITATION ON SATURDAY WITH SOME LOW LEVEL DRYING BEFORE THE
NEXT SYSTEM AFFECTS THE REGION.
MODELS ARE COMING IN AN AGREEMENT IN MOVING A CLOSED LOW FROM WEST
TO EAST DIRECTLY OVER THE AREA INSTEAD OF EJECTING IT OUT MORE
NORTH. PRECIPITATION TYPE STILL IS AMBIGUOUS AT THIS TIME BUT
PRECIPITATION CHANCES WERE RAISED AREA WIDE WITH GROWING
CONFIDENCE IN THE TRACK OF THIS SYSTEM. THE UPPER LEVEL SYSTEM IS
FORECAST TO SWEEP OUT OF WEST TEXAS ON TUESDAY BUT WE COULD SEE
SOME TROWAL PRECIPITATION BEFORE THE SYSTEM FINALLY DEPARTS EAST.
AFTERWARDS...TEMPERATURES WILL WARM IN TIME FOR A THANKSGIVING DAY
FEAST. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 55 17 26 19 31 / 0 20 40 30 20
TULIA 59 19 27 23 34 / 10 20 40 30 20
PLAINVIEW 64 21 27 23 33 / 10 20 40 30 20
LEVELLAND 67 22 29 21 33 / 0 30 40 30 20
LUBBOCK 69 24 29 25 34 / 10 30 40 30 20
DENVER CITY 68 23 29 22 33 / 0 40 40 30 20
BROWNFIELD 70 24 29 24 34 / 10 40 40 30 20
CHILDRESS 65 24 31 27 38 / 20 30 40 30 20
SPUR 72 25 31 26 37 / 20 40 40 30 20
ASPERMONT 73 27 32 29 39 / 20 50 40 30 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS AMARILLO TX
523 AM CST THU NOV 21 2013
.DISCUSSION...
MULTIPLE CHANCES TO SEE A WINTRY MIX OF PRECIPITATION STILL EXPECTED
FROM TODAY THROUGH EARLY NEXT WEEK.
THE ARCTIC COLD FRONT CONTINUES TO SURGE SOUTHWARD ABOUT 3 HOURS
AHEAD OF SCHEDULE FROM YESTERDAY. THE MODELS WITH THE CLOSEST
DEPICTION OF THE FASTER FRONTAL TIMING HAS BEEN THE RUC AND THE 00Z
GFS. WITH A BLEND OF THESE TWO MODELS THE FRONT IS EXPECTED TO BE
MOSTLY THROUGH THE PANHANDLES BY NOON TODAY. THIS WILL CAUSE HIGH
TEMPERATURES TO BE COLDER THAN PREVIOUSLY ADVERTISED. THE MOST
NOTICEABLE CHANCE IN TEMPERATURE FROM YESTERDAY WILL BE IN THE
OKLAHOMA PANHANDLE WHICH REACHED INTO THE 60S BUT WILL STRUGGLE TO
REACH THE 40 DEGREE MARK TODAY.
THE FORECAST STILL SHOWS DECENT CHANCES FOR THE TEXAS AND OKLAHOMA
PANHANDLE TO SEE SOME FORM OF WINTRY PRECIPITATION BETWEEN NOW AND
SATURDAY MORNING. THE QUESTION WILL BE WHERE CAN WE GET ENOUGH
MOISTURE IN THE DENDRITIC SNOW GROWTH ZONE TO MAKE A SOLID TRANSITION
TO MOSTLY OR ALL SNOW. THE BEST AREA FOR THIS TO HAPPEN IS EXPECTED
TO BE NORTH OF A DALHART TO ELKHART LINE. THE REMAINDER OF THE AREA
WILL HAVE A CHANCE TO SEE A FEW FLAKES BUT FREEZING DRIZZLE AND OR
FREEZING RAIN SEEMS A MORE LIKELY FORECAST. WHILE WE ARE EXPECTING
ANY WINTRY PRECIPITATION ACCUMULATIONS TO REMAIN LIGHT LOCATIONS NORTH
OF THE DALHART TO ELKHART LINE COULD SEE BETWEEN 1 TO 3 INCHES OF
SNOW WHILE THERE WILL BE A CHANCE FOR LIGHT ICE ACCUMULATIONS ACROSS
ELEVATED SURFACES ACROSS THE PANHANDLES.
SATURDAY REMAINS THE LULL DAY BEFORE A CLOSED UPPER LEVEL LOW EJECTS
FROM THE DESERT SOUTHWEST. AS THIS LOW MOVES ACROSS THE PANHANDLES WE
COULD SEE ANOTHER ROUND OF WINTRY PRECIPITATION WHICH MAY NEED AN
ADVISORY FOR THE SATURDAY NIGHT AND SUNDAY TIME FRAME. BY MONDAY DRIER
CONDITIONS BEGIN TO SETTLE IN FOR THE LATER HALF OF THIS FORECAST
CYCLE.
&&
.FIRE WEATHER...
NEITHER ELEVATED NOR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
FOR THE NEXT SEVEN DAYS.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
08/14
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
409 AM CST THU NOV 21 2013
.SHORT TERM...
A STRONG COLD FRONT WAS BARRELING SOUTH THIS MORNING THROUGH THE
HIGH PLAINS. AT 3 AM CST THE LEADING EDGE OF THE FRONT WAS LOCATED
NEAR PUEBLO COLORADO TO GREAT BEND KANSAS. NORTHERLY WINDS OF 25 TO
35 MPH WERE BLOWING BEHIND THE FRONT WITH 6 TO 8 MB/6 HR PRESSURE
RISES AND TEMPERATURES WERE QUICKLY DROPPING INTO THE SINGLE DIGITS
ACROSS MUCH OF WYOMING. THE FRONT/S ADVANCE WAS A COUPLE HRS AHEAD OF
NAM AND GFS GUIDANCE...NOT UNUSUAL...WHILE THE HRRR AND RAP
SHORT-RANGE PROGS WERE MORE IN LINE WITH THE FRONT/S ACTUAL
PROGRESS. THE RAP SUGGESTS A WEAK NW-N WIND SHIFT WILL WORK THROUGH
THE CWFA THIS MORNING. THIS SHOULD HELP SCOUR OUT THE LOW STRATUS AND
FOG FROM NORTH TO SOUTH EARLY TO MID MORNING. THE ACTUAL FRONT COULD
BE ON THE DOORSTEP OF OUR NORTHERN COUNTIES BY ABOUT NOON...AND
CLEAR OUR SRN COUNTIES BY 5 PM OR SO. HIGH TEMPERATURES MAY BE
REACHED AROUND NOON ACROSS THE NORTH...WITH TEMPS FALLING IN THE
AFTERNOON...THEN FALLING QUICKLY FOR ALL AREAS IN THE EVENING AS THE
CAA REALLY TAKES HOLD. WE/VE COOLED TEMPS DOWN QUITE A BIT ACROSS
THE NORTH WHILE WE STILL EXPECT SOUTHERN ZONES TO REACH THE UPPER
60S AND LOW 70S BEFORE THE FRONT HITS.
IT APPEARS THAT THE PRE-FRONTAL WIND SHIFT AND EARLIER FROPA WILL
REALLY LIMIT T-STORM CHANCES THIS AFTERNOON AND EVENING...LIKELY
CONFINING THE RISK AREA TO THE EASTERN AND SOUTHERN ROLLING
PLAINS...AND WE/VE TRIMMED POPS BACK ACCORDINGLY. STRONG LIFT ALONG
THE FRONT MAY LEAD TO THE DEVELOPMENT OF A THIN LINE OF STORMS AS
SUGGESTED BY THE TTU-WRF. SOME ISOLD STRONGER CORES WITH SMALL HAIL
ARE POSSIBLE...BUT SEVERE POTENTIAL LOOKS SMALL.
THEN THE MAIN FOCUS WILL QUICKLY SHIFT TO TIMING THE CHANGEOVER TO
FREEZING PRECIP FRIDAY EVENING AND WHAT ARE THE POTENTIAL
ACCUMULATIONS. FORECAST TEMP PROFILES SHOW THAT THE SWITCH COULD
BEGIN AS EARLY AS 8 OR 9 PM ACROSS THE FAR SRN PANHANDLE WITH TEMPS
LIKELY COLD ENOUGH TO SUPPORT FROZEN PRECIP ACROSS THE ENTIRE CWA
ASIDE FROM THE SOUTHERN ROLLING PLAINS BY AROUND MIDNIGHT.
HOWEVER...FRIDAY EVENING...FORECAST SOUNDINGS DO NOT SHOW DEEP
SATURATION THUS WE ANTICIPATE THAT PRECIP INITIALLY IN THE WAKE OF
THE FRONT WILL START OUT AS DRIZZLE...THEN MIX AND SWITCH TO
FREEZING DRIZZLE. DEEPER SATURATION AND BETTER MID-LVL LIFT IS
PROGGED TO ARRIVE AFTER MIDNIGHT AND DURING THE MIDNIGHT TO 6 AM
PERIOD WE SHOULD SEE BETTER CHANCES AT SOME SLEET AND FREEZING RAIN.
SLEET WILL ALSO BE MORE LIKELY ACROSS THE COLDER AREAS OF THE NW
SPLNS AND SW TX PANHANDLE...WITH FREEZING DRIZZLE/RAIN DOMINANT IN
THE ROLLING PLAINS. FORECAST ICE/SLEET PRECIP ACCUMULATIONS LOOK
MINIMAL BEFORE MIDNIGHT...THEN INCREASE SOMEWHAT BY 6 AM...ALTHOUGH
REMAINING LIGHT. THE INITIAL ACCUMULATIONS WILL ALSO /HOPEFULLY/ BE
MITIGATED SOMEWHAT BY THE RELATIVELY WARM GROUND. THUS...AT THIS
TIME WE WILL NOT HOIST ANY WINTER WEATHER ADVISORIES...ALTHOUGH IT
IS NOT OUT OF THE QUESTION THAT ONE MAY BE NEEDED AFTER MIDNIGHT.
ALSO OF NOTE WILL BE THE GUSTY NORTH WINDS AND THE COLD WIND CHILL
TEMPS. BOTH OF THESE ARE EXPECTED TO FALL SHORT OF ADVISORY
CONDITIONS BUT WILL CONTRIBUTE TO AN OVERALL WINTRY ATMOSPHERE.
&&
.LONG TERM...
A COMPLEX FORECAST CONTINUES ON IN THE LONG TERM FORECAST THROUGH
AT LEAST EARLY NEXT WEEK. THE MAIN ISSUE WILL BE THE PRECIPITATION
TYPE AND INTENSITY. BEST CHANCES OF PRECIPITATION WILL BE
MAINTAINED DURING THE DAY ON FRIDAY WITH LESSER CHANCES ON
SATURDAY. LIFT FROM WARM AIR ADVECTION ABOVE THE COLD AIR DOME
WILL GENERALLY BE WEAK. FLOW ON THE MOIST ISENTROPIC SURFACES WILL
BE ONLY 5-10 KNOTS THROUGH THE DURATION OF THE EVENT.
HOWEVER...SOME STRONGER FLOW MAY BE POSSIBLE NEAR THE TEXAS/NEW
MEXICO STATE LINE. A MID LEVEL DRY LAYER AROUND 700MB WILL ENTER
THE AREA ON FRIDAY WHICH ADDS SOME ADDITIONAL COMPLEXITY TO THE
PRECIPITATION TYPE. AS COLD AS THE TEMPERATURE WILL BE AT THE
SURFACE...WOULD MOSTLY EXPECT EITHER FREEZING DRIZZLE OR SLEET.
THE WARM LAYER ALOFT WILL START OUT ON FRIDAY AROUND AN ASTOUNDING
7-9C BUT SLOWLY WEAKEN THROUGH THE EVENT. THE SUBFREEZING LAYER AT
THE SURFACE ON FRIDAY WILL BE AROUND 3KFT ALLOWING FOR POSSIBLE
SLEET TO DEVELOP. WITH THE LIFT GENERALLY BEING WEAK...WOULD
ANTICIPATE MORE DRIZZLE THAN RAINFALL. THERE MAY BE A SLIGHT LULL
IN PRECIPITATION ON SATURDAY WITH SOME LOW LEVEL DRYING BEFORE THE
NEXT SYSTEM AFFECTS THE REGION.
MODELS ARE COMING IN AN AGREEMENT IN MOVING A CLOSED LOW FROM WEST
TO EAST DIRECTLY OVER THE AREA INSTEAD OF EJECTING IT OUT MORE
NORTH. PRECIPITATION TYPE STILL IS AMBIGUOUS AT THIS TIME BUT
PRECIPITATION CHANCES WERE RAISED AREA WIDE WITH GROWING
CONFIDENCE IN THE TRACK OF THIS SYSTEM. THE UPPER LEVEL SYSTEM IS
FORECAST TO SWEEP OUT OF WEST TEXAS ON TUESDAY BUT WE COULD SEE
SOME TROWAL PRECIPITATION BEFORE THE SYSTEM FINALLY DEPARTS EAST.
AFTERWARDS...TEMPERATURES WILL WARM IN TIME FOR A THANKSGIVING DAY
FEAST. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 55 17 26 19 31 / 0 20 40 30 20
TULIA 59 19 27 23 34 / 10 20 40 30 20
PLAINVIEW 64 21 27 23 33 / 10 20 40 30 20
LEVELLAND 67 22 29 21 33 / 0 30 40 30 20
LUBBOCK 69 23 29 24 33 / 10 30 40 30 20
DENVER CITY 68 23 29 22 33 / 0 40 40 30 20
BROWNFIELD 70 24 29 24 34 / 10 40 40 30 20
CHILDRESS 65 24 31 27 38 / 20 30 40 30 20
SPUR 72 25 31 26 37 / 20 40 40 30 20
ASPERMONT 73 27 32 29 39 / 20 50 40 30 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/01
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
327 PM CST THU NOV 21 2013
.SHORT TERM...
TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
LATEST RUNS OF HRRR AND 4 KM WRF/NMM MODELS ARE INDICATING THAT THE
MOISTURE WILL BE DELAYED UNTIL LATER THIS EVENING FOR THE ARRIVAL OF
THE EXPECTED AREA OF PRECIPITATION. CURRENT AREA OF PRECIPITATION
OVER SOUTH CENTRAL IOWA MAY STRUGGLE TO MAKE IT HERE...AS THIS WILL
FIGHT DRY LOW LEVELS OVER THE AREA. FOR NOW...WILL PUSH BACK ARRIVAL
OF PRECIPITATION A BIT THIS EVENING...AS WELL AS THE CHANGEOVER TO
LIGHT SNOW LATER TONIGHT.
SYNOPTIC AND MESOSCALE MODELS ARE SLOWING THE SATURATION OF THE AIR
COLUMN UNTIL MID TO LATE EVENING FROM SOUTHWEST TO NORTHEAST. AREA
OF GOOD 850MB TO 700MB FRONTOGENESIS RESPONSE WILL PUSH EAST
SOUTHEAST THROUGH THE AREA BETWEEN 06Z AND 15Z FRIDAY...DRIVING THE
MAIN AREA OF PRECIPITATION. BEST UPWARD VERTICAL MOTION WILL BE OVER
THE NORTHWEST HALF OF THE AREA LATER TONIGHT...WITH AREAS TO THE
SOUTHEAST SEEING LESS.
AIR COLUMN WILL COOL FROM THE TOP DOWN AS COLD AIR ADVECTION KICKS
IN TONIGHT...SO WILL CONTINUE THE TRANSITION FROM RAIN OR RAIN/SNOW
MIX TO ALL LIGHT SNOW FROM NORTHWEST TO SOUTHEAST. EXPECTING AROUND
0.5 INCHES ON GRASSY AREAS FROM DARLINGTON TO MADISON TO SHEBOYGAN
AND NORTHWESTWARD...WITH LOWER AMOUNTS TO THE SOUTHEAST.
MILWAUKEE...RACINE AND KENOSHA MAY ONLY SEE A DUSTING AT BEST.
CLOUDS WILL GRADUALLY MIX OUT LATER ON FRIDAY...WITH COLD AIR
ADVECTION CONTINUING. WINDS WILL GRADUALLY WEAKEN AS THE DAY GOES
ON...BUT TEMPERATURES WILL STRUGGLE TO RISE MUCH OUT OF THE LOWER
TO MID 30S.
FRIDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE HIGH
LOW PRESSURE MOVING EAST ACROSS THE NORTHERN GREAT LAKES AND NEW
ENGLAND WILL SWEEP AN ARCTIC COLD FRONT ACROSS THE REGION FRI NT
INTO SAT. 850 MB TEMPS TO DROP TO -17C ON SAT AND SCT-BKN
STRATOCUMULUS CLOUDS ARE EXPECTED. HIGH TEMPS ONLY IN THE 20S
ARE FORECAST AND BRISK WINDS WILL MAKE FOR WIND CHILLS IN THE
SINGLE DIGITS AND TEENS ALL WEEKEND. ARCTIC HIGH PRESSURE TO THEN
MOVE FROM THE NRN PLAINS TO THE UPPER MS RIVER VALLEY BY 12Z SUN.
LIGHTER WIND AND RADIATIONAL COOLING WILL SUPPORT VERY COLD TEMPS
IN THE SINGLE DIGITS OVER SOUTH CENTRAL WI AND TEENS IN ERN WI.
THE HIGH WILL MOVE EAST FOR SUN AFTERNOON WITH SWLY WINDS AND WARM
ADVECTION BEGINNING. HIGH TEMPS ONCE AGAIN STUCK IN THE 20S.
.LONG TERM...
SUNDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM
SWLY WINDS AND WARM ADVECTION WILL CONTINUE SUN NT INTO MON AS LOW
PRESSURE ONCE AGAIN TRACKS EAST ACROSS SRN CANADA. THERE ARE SMALL
CHANCES OF LGT SNOW WITH THE WARM ADVECTION DURING THIS TIME. A
COLD FRONT...WEAKER THAN PREVIOUS FRONTS...WILL MOVE ACROSS THE
REGION MON NT AND WILL BE ABLE TO MAINTAIN BELOW NORMAL TEMPS.
NWLY WINDS WILL THEN PREVAIL TUE-WED WITH A POLAR HIGH FINALLY
ARRIVING OVER WI FOR THANKSGIVING DAY. MAINLY DRY AND COLD
CONDITIONS ARE EXPECTED.
&&
.AVIATION/00Z TAFS/...
MVFR CEILINGS ARE EXPECTED TO SPREAD EAST ACROSS THE EASTERN SITES
BY EARLY THIS EVENING. MADISON WILL SEE MVFR CEILINGS AS WELL. WINDS
WILL BECOME NORTH NORTHWESTERLY THIS EVENING...GRADUALLY BECOMING
STRONGER AS THE NIGHT GOES ON.
EXPECTING LIGHT RAIN WITH MVFR VISIBILITIES AND IFR CEILINGS TO MOVE
INTO MADISON AROUND 03Z FRIDAY...AND AROUND 05Z FRIDAY AT THE
EASTERN SITES. THE LIGHT RAIN SHOULD MIX WITH LIGHT SNOW FOR A FEW
HOURS STARTING BETWEEN 06Z TO 08Z FRIDAY...BEFORE BECOMING ALL LIGHT
SNOW BETWEEN 08Z AND 10Z FRIDAY.
ANY LINGERING LIGHT SNOW SHOULD END BETWEEN 13Z TO 15Z FRIDAY WEST
TO EAST. GUSTY NORTH NORTHWEST WINDS SHOULD OCCUR BY 10Z
FRIDAY...LINGERING THROUGH FRIDAY.
SNOW ACCUMULATIONS ON GRASSY AREAS SHOULD BE AROUND 0.5 INCHES AT
MADISON...WITH A DUSTING AT BEST AT THE EASTERN SITES. RUNWAYS
SHOULD REMAIN JUST WET DURING THIS TIME...AS GROUND TEMPERATURES
REMAIN AROUND OR JUST ABOVE FREEZING DURING THE LIGHT SNOW. MVFR
CLOUDS SHOULD GRADUALLY MIX OUT IN THE AFTERNOON...WITH
NORTH NORTHWEST WINDS GRADUALLY WEAKENING BY LATE AFTERNOON.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM LATE TONIGHT INTO LATE
FRIDAY NIGHT ACROSS THE NEARSHORE WATERS. A TIGHT PRESSURE GRADIENT
WILL DEVELOP WITH THE COLD AIRMASS MOVING INTO THE REGION DURING
THIS TIME...GENERATING GUSTY NORTH NORTHWEST WINDS. THESE WINDS WILL
GENERATE HIGH WAVES UP TO 4 TO 7 FEET FRIDAY.
THE SMALL CRAFT ADVISORY WILL LIKELY NEED TO BE EXTENDED THROUGH
SATURDAY NIGHT...AS ANOTHER SHOT OF COLD AIR SURGES INTO THE AREA.
NORTHWEST WIND GUSTS MAY REACH 35 KNOTS AT TIMES...SO A GALE WATCH
WOULD NEED TO BE CONSIDERED AS WELL. HIGH WAVES WOULD REMAIN TOWARD
AND OVER THE OPEN WATERS.
WINDS WILL BE NEAR SMALL CRAFT ADVISORY LEVELS AT TIMES INTO EARLY
NEXT WEEK...AS THE PRESSURE GRADIENT REMAINS TIGHT ACROSS THE AREA.
HIGH WAVES MAY OCCUR TOWARD THE OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 AM FRIDAY TO 6 AM CST SATURDAY FOR
LMZ643>646.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD
FRIDAY NIGHT THROUGH THURSDAY...GEHRING
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
115 PM CST THU NOV 21 2013
.UPDATE...
LATEST RUNS OF HRRR AND 4 KM WRF/NMM MODELS ARE INDICATING THAT
THE MOISTURE WILL BE DELAYED UNTIL THIS EVENING FOR THE ARRIVAL OF
THE EXPECTED AREA OF PRECIPITATION. THEY KEEP THE AREA FAIRLY DRY
THROUGH 00Z FRIDAY. THUS...WILL LIKELY BE TRENDING DOWNWARD WITH
POPS LATER THIS AFTERNOON. CLOUDY SKIES WILL CONTINUE...KEEPING
TEMPERATURES IN THE LOWER TO MID 40S.
WILL LIKELY PUSH BACK ARRIVAL OF PRECIPITATION THIS EVENING...AS
WELL AS THE CHANGEOVER TO LIGHT SNOW LATER TONIGHT. SYNOPTIC AND
MESOSCALE MODELS ARE SLOWING THE SATURATION OF THE AIR COLUMN
UNTIL MID TO LATE EVENING FROM SOUTHWEST TO NORTHEAST. AREA OF
GOOD 850MB TO 700MB FRONTOGENESIS RESPONSE WILL PUSH EAST
SOUTHEAST THROUGH THE AREA BETWEEN 06Z AND 15Z FRIDAY...DRIVING
THE MAIN AREA OF PRECIPITATION.
AIR COLUMN WILL COOL FROM THE TOP DOWN AS COLD AIR ADVECTION
KICKS IN TONIGHT...SO WILL CONTINUE THE TRANSITION FROM RAIN OR
RAIN/SNOW MIX TO ALL LIGHT SNOW FROM NORTHWEST TO SOUTHEAST. STILL
EXPECTING UP TO AN INCH NEAR THE WISCONSIN DELLS AREA...TO A FEW
TENTHS OF AN INCH TOWARD KENOSHA.
&&
.AVIATION/18Z TAFS/...
VFR CEILINGS ARE EXPECTED AT THE EASTERN SITES THIS AFTERNOON AND
EVENING. MADISON MAY SEE SOME MVFR/IFR CEILINGS PERIODICALLY...BUT
SHOULD COME UP TO VFR AS WELL. LIGHT AND VARIABLE WINDS THIS
AFTERNOON WILL GRADUALLY BECOME NORTH NORTHWEST THIS
EVENING...WITH THE PASSAGE OF THE COLD FRONT.
EXPECTING LIGHT RAIN WITH MVFR VISIBILITIES AND IFR CEILINGS TO
MOVE INTO TAF SITES AT 03Z AT MADISON...AND AROUND 05Z AT THE
EASTERN SITES. THE LIGHT RAIN SHOULD MIX WITH LIGHT SNOW FOR AN
HOUR OR TWO BEGINNING BETWEEN 06Z AND 08Z FRIDAY...BEFORE
BECOMING ALL LIGHT SNOW BETWEEN 08Z AND 10Z FRIDAY.
THE LIGHT SNOW SHOULD END BETWEEN 14Z TO 16Z FRIDAY WEST TO EAST.
GUSTY NORTH NORTHWEST WINDS SHOULD OCCUR BY 10Z FRIDAY...LINGERING
THROUGH FRIDAY.
SNOW ACCUMULATIONS ON GRASSY AREAS SHOULD BE AROUND 0.5 INCHES AT
MADISON...WITH A DUSTING AT THE EASTERN SITES. RUNWAYS SHOULD
REMAIN JUST WET DURING THIS TIME...AS GROUND TEMPERATURES REMAIN
AROUND OR JUST ABOVE FREEZING DURING THE LIGHT SNOW. MVFR CLOUDS
SHOULD GRADUALLY MIX OUT IN THE AFTERNOON.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM LATE TONIGHT INTO LATE
FRIDAY NIGHT ACROSS THE NEARSHORE WATERS. A TIGHT PRESSURE
GRADIENT WILL DEVELOP WITH THE COLD AIRMASS MOVING INTO THE REGION
DURING THIS TIME...GENERATING GUSTY NORTH NORTHWEST WINDS. THESE
WINDS WILL GENERATE HIGH WAVES UP TO 4 TO 7 FEET FRIDAY.
THE SMALL CRAFT ADVISORY MAY NEED TO BE EXTENDED THROUGH SATURDAY
NIGHT...AS ANOTHER SHOT OF COLD AIR SURGES INTO THE AREA.
NORTHWEST WIND GUSTS MAY REACH 35 KNOTS AT TIMES...SO A GALE
WATCH WOULD NEED TO BE CONSIDERED AS WELL. HIGH WAVES WOULD REMAIN
TOWARD AND OVER THE OPEN WATERS.
&&
.PREV DISCUSSION... /ISSUED 511 AM CST THU NOV 21 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
CURRENT LULL IN PCPN SHOULD CONTINUE UNTIL LATE THIS AFTERNOON WITH
APPROACH OF FORCING WITH NEXT SHORT WAVE. LIGHT FOG WILL CONTINUE
WITH LIGHT...MOIST SRLY LOW LEVEL FLOW AHEAD OF SURFACE TROUGH AXIS
UNTIL IT SAGS SOUTHEAST OF CWA AROUND MIDDAY. BLENDED TIMING HAS
PCPN MOVING IN LATE THIS AFTERNOON AND EARLY EVENING PER LAYER Q-
VECTOR CONVERGENCE...WITH THE MAJORITY OF QPF FALLING BETWEEN 03Z
AND 09Z FRIDAY WITH STRONGER 850-700 MB FRONTOGENESIS. TEMPS WARM
ENOUGH FOR ALL RAIN TO START...THEN RAIN WILL MIX AND CHANGE OVER TO
SNOW WITH COLLAPSE OF COLUMN TEMPS ON FORECAST SOUNDINGS OVERNIGHT.
LOW QPF AMOUNTS WILL HOLD SNOW TOTALS IN THE NW TO AROUND 1
INCH...WHILE SE WILL ONLY SEE A DUSTING TO A FEW TENTHS OF AN INCH
WITH LATER TURNOVER.
MODELS KEEP 925 MB TEMPS AT/ABOVE 0C UNTIL 00Z FRI...WITH NAM FCST
SOUNDINGS SHOWING MIXING UP TO THESE 925 MB TEMPS WHILE GFS AND
ECMWF DO NOT MIX AS DEEP. WITH WARM OVERNIGHT TEMPERATURES WILL
FOLLOW CONSENSUS TEMPS THAT BRING HIGHS INTO THE LOW TO MID 40S.
THESE SHOULD BE REACHED BY EARLY AFTERNOON...THEN STEADY OR SLOWLY
COOL WITH NORTHWEST WINDS BEHIND PASSAGE OF TROUGH. SLOW COOLING
THROUGH THE EVENING ACCELERATES WITH COLD ADVECTION DROPPING 925 MB
TEMPS COOL TO -3C TO -7C BY 12Z FRIDAY.
FRIDAY - CONFIDENCE...MEDIUM 500 MILLIBAR SHORTWAVE SHIFTS EAST
DURING THE AFTERNOON. THE NAM IS A BIT MORE GENEROUS LINGERING LIGHT
QPF IN THE MORNING WHILE THE GFS AND ECMWF SHOW JUST A HINT IN THE
FAR SE CORNER. 700 WAVE WHISKS EAST FAIRLY QUICK THOUGH STILL A
DECENT FRONTOGENETICAL BAND LINGERING SO WILL KEEP SOME POPS DURING
THE MORNING. AIRMASS COLD ENOUGH FOR ALL SNOW PER BUFKIT SOUNDING
PROFILE. DRIER AIR STARTS TO WORK IN DURING THE AFTERNOON...WITH
SOME AREAS POSSIBLY SEEING SOME SUN BEFORE NOONTIME. BUFKIT/MOS/LOW
LEVEL RH PROGS ALL SUGGESTING THIS SO WILL TREND THE SKY
GRIDS IN THIS DIRECTION.
FRIDAY NIGHT AND SATURDAY - CONFIDENCE...MEDIUM COLD FRONT
ARRIVES WITH 850 TEMPS PLUNGING FROM AROUND -5C EARLY FRIDAY
EVENING TO AROUND -15 TO -18C SATURDAY MORNING. 925 TEMPS AROUND
-11 TO -13C WITH BLUSTERY CONDITIONS. SO TEMPS WILL STRUGGLE IN
THE 20S SATURDAY. UPPER FLOW IS STILL STRONGLY CYCLONIC THOUGH
AIRMASS PROGGED TO BE VERY DRY.
SATURDAY NIGHT AND SUNDAY - CONFIDENCE... VERY COLD AIRMASS IN
PLACE. 925 TEMPS AVERAGING -14C. WINDS EXPECTED TO DROP OFF ESP IN
SC WI WHERE SFC RIDGE AXIS NUDGES IN WITH TIME. SINGLE DIGIT TEMPS
QUITE LIKELY IN THESE AREAS. RIDGE AXIS SHIFTS EAST LATER ON SUNDAY
ALLOWING FOR EASTWARD DISPLACEMENT OF LOW LEVEL THERMAL TROUGH.
TEMPS WILL ONCE AGAIN STRUGGLE INTO THE 20S FOR DAYTIME HIGHS.
SUNDAY NIGHT AND MONDAY - CONFIDENCE...MEDIUM GFS/ECMWF SHOWING
PRECIP DEVELOPMENT WITH SURFACE/850 FRONTS. SOME RIGHT ENTRANCE
REGION JET DYNAMICS AT PLAY AS WELL. 1000-500 MILLIBAR THICKNESSES
BORDERLINE THOUGH BUFKIT SOUNDINGS...850/925 TEMPS PRETTY SUPPORTIVE
OF ALL SNOW. ECMWF A BIT MORE ROBUST WITH QPF AMOUNTS IN THE SE
BETWEEN 12-18Z MONDAY SHOWING OVER 0.10 LIQUID. POPS MAY NEED TO BE
RAISED IF MODEL CONSISTENCY/CONSENSUS BECOMES ESTABLISHED.
TUESDAY AND WEDNESDAY - CONFIDENCE...MEDIUM COLD AIRMASS GETS
REINFORCED ON THE ECMWF WITH ANOTHER COLD TROUGH BEING CARVED OUT
ACROSS THE WESTERN LAKES...WHILE THE GFS KEEPS THIS FURTHER NORTH
WHILE THE GFS HAS MORE OF A GLANCING SHOT OF THIS FURTHER NORTH. SO
A DISCREPANCY EXISTS WITH THE THERMAL FIELDS DURING THIS PERIOD.
LEANED ON THE ALLBLEND AT THIS POINT.
AVIATION/12Z TAFS/...
CURRENT MVFR VSBYS AND CEILINGS WILL LINGER THROUGH MOST OF THE DAY
..EXCEPT AT EASTERN TAF SITES WHERE TEMPS HAVE HELD UP WITH FLOW
OFF OF RELATIVELY WARMER LAKE. THESE LOCATIONS ARE EXPECTED TO DIP
TO MVFR LEVELS LATER THIS MORNING INTO THE AFTERNOON AS TEMPS COOL
WITH WINDS BECOME LIGHT WESTERLY...THEN NORTHWEST AS SURFACE TROUGH
SAG SOUTH. NEXT SHORT WAVE BRINGS CHC OF PCPN INTO SRN WI AROUND
21Z...WITH STEADY LIGHT PCPN BY MID-EVENING. WILL START OUT AS
RAIN...THEN MIX WITH SNOW AT KMSN BY 04Z...AND EASTERN SITES AROUND
MIDNIGHT.
KMSN WILL GO OVER TO ALL LIGHT SNOW BY MIDNIGHT...WITH SNOW TOTALS
AROUND 1/2 INCH. KENW AND KMKE WILL STAY MIXY UNTIL 09Z..THEN ALL
LIGHT SNOW. LATE TURNOVER WILL LIMIT ACCUMULATIONS TO A FEW TENTHS
OF AN INCH...MAINLY ON GRASSY AREAS. WILL SEE OCCASIONAL IFR VSBYS
DURING THE PERIOD OF STEADY LIGHT PCPN.
MARINE...
SMALL CRAFT ADVISORY ALLOWED TO EXPIRE AS WINDS AND WAVES HAD
SUBSIDED BY 10Z. ISSUED ANOTHER ADVISORY FOR LATE TONIGHT THROUGH
FRIDAY NIGHT AS NORTH WINDS INCREASE BEHIND SURFACE TROUGH TONIGHT
WITH THE LONG FETCH BUILDING WAVES TO 3 TO 6 FEET BY FRIDAY MORNING.
WINDS EASE FOR A TIME FRIDAY AFTERNOON AS SURFACE RIDGE PASSES
THROUGH...THEN INCREASE AGAIN FROM THE WEST BACK TO SMALL CRAFT
LEVELS. TIME PERIOD WAS TOO SHORT TO BREAK HEADLINE.
CURRENT END TIME REFLECTS POTENTIAL FOR GALES SATURDAY...BUT TOO
MUCH UNCERTAINTY TO ISSUE A WATCH. IF LATER FORECASTS DO NOT SUPPORT
A GALE HEADLINE...THEN CURRENT ADVISORY WILL HAVE TO BE EXTENDED AS
CURRENT FORECAST WINDS STAY UP INTO SUNDAY MORNING.
WINDS AND WAVES MAY REACH SMALL CRAFT ADVISORY LEVELS AT TIMES
EARLY NEXT WEEK...AS GUSTY OFFSHORE WINDS ARE EXPECTED AS LOW
PRESSURE PASSES THOUGH NORTH OF LAKE SUPERIOR. HIGH WAVES TOWARD THE
OPEN WATERS ARE POSSIBLE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 AM FRIDAY TO 6 AM CST SATURDAY FOR
LMZ643>646.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...REM
FRIDAY THROUGH WEDNESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
355 AM CST Sat Nov 23 2013
.SHORT TERM...(Today and Tonight)
Issued at 346 AM CST SAT NOV 23 2013
Regional radar indicates a few echoes of light precipitation over
eastern Kansas. At this time expect those echoes to represent some
mid to high based precipitation, occurring at roughly 10 to 12 kft,
where RAP soundings indicate the lowest level of saturation. Below
that level, soundings indicate very dry air, which will preclude any
of the precipitation from reaching the surface.
The cold weather will continue across the area through the rest of
the weekend as cold northerly air continues to filter into the
Central Plains. The major culprit for this abnormally cold period is
an incredibly anomalous surface ridge located right on the Canadian
border with North Dakota. Currently, observations in far southern
Canada indicated roughly 1050 mb for the surface ridge and
temperatures in the -15 to -20 range. This ridge will slide
south/southeast and become centered over northern Missouri late
Saturday night into early Sunday morning. NAM has the surface ridge
approaching 1050 mb even as it becomes centered over the KC Metro
Sunday morning. Should the ridge maintain 1045 to 1050 mb as it
moves into the KC Metro its anomaly would carry nearly 4 standard
deviations from the seasonal normal, an incredible value.
Ahead of this ridge, cold air will continue to move into northern
and central Missouri causing temperatures on Saturday to remain
extremely chilly, with highs generally remaining in the lower to
middle 20s along and north of Interstate 70, with perhaps a few
areas south of Interstate 70 reaching the lower 30s.
As the aforementioned ridge moves overhead Saturday night the skies
will clear and winds will go calm, providing an incredible
opportunity for the surface to radiate outward. The result will be
record - or at the very least - near record temperatures for Sunday
morning across all of eastern Kansas and northern/central Missouri.
Even though the source region of this ridge demonstrates
temperatures well below 0 the lack of snow cover across areas north
of the forecast area will allow the airmass to modify. At this time
we can expect temperatures along and north of Interstate 70 to be in
the single digits - near zero degrees - Sunday morning, with areas
along Interstate 70 being near 10 degrees, and areas south of the
interstate being in the 10 to 15 degree range (See Climate portion
of the AFD for record lows for 11/24 in the KC Metro and St.
Joseph). Wind chills for Sunday morning will closely resemble the
morning lows, since the ridge being parked overhead will generally
prevent much in the way of surface flow, but ironically the coldest
wind chills Sunday morning could occur south of Interstate 70 where
light easterly winds in combination with the cold temperatures could
bring wind chill values to near zero. Only a modest diurnal warming
can be expected for Sunday as sunshine and perhaps the beginning of
southerly return flow could aid in getting the temperatures back
near the middle 30s by Sunday afternoon.
Very little - if any - relief from the cold temperatures are
expected through the early part of next week. In fact, after
Monday`s "warming" trend back into the lower 40s, expect another
cold front to blast through the area pulling temperatures back into
the 20s and 30s for Tuesday. At this time will continue a dry
forecast into the early part of the week, but there is a hint that
there could be some extremely light snowfall on Sunday night into
Monday morning. Southerly return flow late Sunday could usher a very
tiny amount of low level moisture into the area and spread it over
the aforementioned very cold surface temperatures. With a southern
stream cutoff low over the 4 Corner region, and a northern stream
long wave trough gently sagging southward into the area there could
be some ascent interaction with the moisture, however at this point
it was very difficult to even find modest lift. So, as previously
mentioned, have gone with a dry forecast for Sunday night, but
upcoming shifts will need to monitor the chances for very light,
likely non-accumulating, snow for Sunday night into Monday morning.
.LONG TERM...(Sunday through Friday)
Issued at 346 AM CST SAT NOV 23 2013
For Tuesday, and through the rest of the week, cool and dry
conditions are expected to prevail. Medium range operational and
ensemble models all point at Tuesday arriving with a trough swinging
through the center of the nation. Below the base of the trough a
cutoff low --currently noted spinning over Southern California--
will be phasing with the larger synoptic trough. Models continue to
show strong agreement that the cutoff low, even as it phases into
the base of trough, will stay south of Kansas and Missouri as it
transits the nation, thus allowing still more cold dry Canadian air
to slip south into the Plains States as a northwest flow prevails.
However, by late in the work week Tuesdays prevailing trough will
have pivoted fare to our east, and with another shortwave trough
expected to drop into the West Coast the flow across the center of
the nation should transit to more of a zonal flow across the Plains,
thus allowing a little moderation in our temperatures for the tail
end of the week. Thus, at this time, dry weather is expected, with
highs in the 30s prevailing Tuesday and Wednesday, creeping into the
40s for Friday and Saturday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1110 PM CST FRI NOV 22 2013
VFR conditions are expected through the entire forecast as deeper, drier
air continues to build into the region from the north. Despite the
absence of lower clouds, a steady stream of mid to upper level
moisture should keep things cloudy with high level clouds. Winds will
be persistent from the north, increasing some tomorrow morning and
becoming gusty. Winds should diminish very late in the valid period
as high pressure builds into the region.
&&
.CLIMATE...
Issued at 346 AM CST SAT NOV 23 2013
Record lows for November 24...
Value Date
Kansas City 9 11/24/1950
St. Joseph 9 11/24/1950
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Leighton
LONG TERM...Cutter
AVIATION...CDB
CLIMATE...Leighton
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
324 AM EST SAT NOV 23 2013
.SYNOPSIS...
A STRONG ARCTIC COLD FRONT WILL CROSS THE AREA LATER THIS MORNING
FOLLOWED BY THE COLDEST TEMPERATURES OF THE SEASON. LOW PRESSURE
WILL EMERGE FROM THE NORTHERN GULF OF MEXICO BRINGING A SIGNIFICANT
RAIN EVENT FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...AN ARCTIC COLD FRONT CURRENTLY EXTENDING
FROM SOUTHEASTERN VIRGINIA INTO THE NC FOOTHILLS IS EXPECTED TO
MOVE SOUTHEAST...CROSSING THROUGH THE EASTERN CAROLINAS LATE THIS
MORNING. THERE ARE MINOR TIMING DIFFERENCES WITH THIS FRONT BUT IT
APPEARS THE 06/07Z RUC HAS THE BEST HANDLE ON ITS CURRENT AND
FORECAST POSITIONS OUT THROUGH 18Z. AS IS TYPICAL WITH A MORNING
COLD FRONTAL PASSAGE...MOS HIGHS SHOULD BE SEVERAL DEGREES TOO
COOL AS THEY RESOLVE A WIDE/BLURRED FRONTAL ZONE RATHER THAN THE
TIGHT TEMPERATURE GRADIENT THAT ACTUALLY EXISTS. MY FORECAST HIGHS
ARE 2-3 DEGREES ABOVE MOS (63-68...WARMEST NEAR GEORGETOWN)
ALTHOUGH THESE READINGS SHOULD OCCUR ONLY BRIEFLY AT THE TIME OF
FRONTAL PASSAGE WITH FALLING TEMPERATURES EXPECTED THROUGHOUT THE
AFTERNOON.
RADAR COMPOSITES REVEAL LARGE AREA OF VERY LIGHT SHOWERY RAIN ACROSS
THE CAROLINAS CURRENTLY. THIS APPEARS TO BE ASSOCIATED WITH WEAK
ISENTROPIC LIFT WITHIN A MID-LAYER CLOUD DECK 7000-12000 FT AGL.
MODELS SHOW ISENTROPIC LIFT HAVING ITS GREATEST MAGNITUDE (AND
THAT`S NOT SAYING MUCH) BETWEEN NOW AND NOON...WITH NEUTRAL TO
ISENTROPIC DOWNGLIDE CONDITIONS DEVELOPING DURING THE AFTERNOON. MY
QPF NUMBERS ARE BARELY A TENTH OF AN INCH OR LESS IN MOST SPOTS.
CLOUDS WILL PROBABLY NOT BREAK IN ANY SUBSTANTIAL SENSE DURING THE
DAY...AND THE LACK OF INSOLATION WILL NOT BE ABLE TO OFFSET
STRENGTHENING COLD ADVECTION DURING THE AFTERNOON.
FOR TONIGHT HIGH PRESSURE OVER THE CENTRAL PLAINS WILL SURGE
EASTWARD AS A SHORTWAVE EMBEDDED IN THE NORTHEASTERN U.S. TROUGH
SWINGS THROUGH VIRGINIA. THIS WILL LEAD TO THE REAL ARCTIC SURGE OF
THIS EVENT DEVELOPING AROUND OR JUST BEFORE MIDNIGHT. 850 MB
TEMPERATURES WILL FALL FROM AROUND +6C THIS EVENING TO -3C BY
DAYBREAK SUNDAY...AS WINDS AT THE TOP OF THE WELL-MIXED BOUNDARY
LAYER WINDS INCREASE TO 20-30 KNOTS. THE TEMPERATURE FORECAST
TONIGHT IS ACTUALLY QUITE TRICKY AS STRONG WINDS AND GOOD MIXING CAN
SOMETIMES CREATE A NIGHTTIME DEEP DRY-ADIABATIC PROFILE TYPICAL OF
DAYTIME CONDITIONS...WITH LOW TEMPERATURES ENDING UP MUCH WARMER
THAN ONE WOULD THINK POSSIBLE GIVEN THE AIRMASS. MY FORECAST LOWS
ARE A BIT ABOVE MOS GUIDANCE AND RANGE FROM NEAR FREEZING FROM
LUMBERTON TO DARLINGTON...TO 35-38 AT THE COAST.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...COLD AND DRY ARCTIC HIGH BUILDS IN SUNDAY WITH
TEMPERATURES FALLING SHORT OF 50 DURING THE DAY. SURFACE RIDGE AXIS
SHIFTS CLOSE TO THE REGION SUN NIGHT...ENDING COLD ADVECTION BUT
PUTTING RADIATIONAL COOLING IN PLAY. DEEP DRY AIR...LIGHT
WINDS...AND UNSEASONABLY COLD AIR IN PLACE WILL RESULT IN LOWS IN
THE LOW TO MID 20S IN MANY LOCATIONS WITH ISOLATED UPPER TEENS
POSSIBLE INLAND.
WHILE SOME AIR MASS MODIFICATION IS EXPECTED ON MON VERY LOW
STARTING TEMPS COMBINED WITH NORTHEAST FLOW WILL AGAIN KEEP HIGHS
WELL BELOW CLIMO. INCREASING HIGH CLOUD MON AFTERNOON WILL LIMIT
INSOLATION...FURTHER HINDERING TEMP RECOVERY. CLOUDS START TO LOWER
MON NIGHT AS WEAK ISENTROPIC LIFT IS ENHANCED BY DEVELOPMENT OF WEAK
COASTAL TROUGH MON NIGHT. GIVEN THE DEPTH OF THE DRY AIR AND THE
PROPENSITY OF GUIDANCE TO UNDERESTIMATE THE DRY AIR AND THUS
INTRODUCE POP A LITTLE TOO EARLY DO NOT PLAN MAJOR CHANGES TO
INHERITED PRECIP CHANCES MON NIGHT. INCREASING CLOUD COVER WILL HELP
KEEPS MON NIGHT LOWS SIGNIFICANTLY WARMER THAN SUN NIGHT AND MORE
IMPORTANTLY ABOVE FREEZING.
AT THIS POINT IT DOES NOT APPEAR THE MONDAY MORNING RECORD LOWS WILL
BE IN PLAY.
RECORD LOWS FOR NOVEMBER 25 AND THE NORMALS:
--------------------------------------------
ILM - 20 - 1970 NORMAL - 43
FLO - 17 - 1950 NORMAL - 41
CRE - 17 - 1950 NORMAL - 44
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...PERIOD BEGINS WITH A SOUTHERN STREAM SYSTEM
ALREADY AFFECTING THE REGION. ISENTROPIC LIFT WILL TAP INTO DEEP
MOISTURE SPREADING OVER THE AREA AHEAD OF THE GULF COAST SYSTEM ON
TUE. THIS WILL LEAD TO RAIN WITH INTENSITY GRADUALLY INCREASING
THROUGHOUT THE DAY. AT THIS POINT THE MEDIUM RANGE SOLUTIONS DIVERGE
SOMEWHAT. DISTANCE WISE THE TRACKS ARE NOT FAR APART...BUT AS IS
USUALLY THE CASE FOR THE COASTAL CAROLINAS A SMALL DIFFERENCE IN THE
TRACK COULD LEAD TO HUGE DIFFERENCES IN THE FORECAST. WHAT IS KNOWN
IS A POTENT STORM IS LIKELY TO IMPACT THE REGION WITH HEAVY RAIN AND
GUSTY WINDS LATE TUE NIGHT AND WED. THE NATURE OF THE
RAIN...STRATIFORM AS OPPOSED TO MORE CONVECTIVE AND HIGH/LOW
TEMPERATURES ARE WHAT REMAIN UNCERTAIN. AN INLAND TRACK WOULD LEAD
TO WARMER TEMPERATURES BUT ALSO OPEN UP THE POSSIBILITY OF SEVERE
WEATHER. THE INHERITED FORECAST LIES IN THE MIDDLE OF THE GUIDANCE
ENVELOPE AND REMAINS IN GOOD AGREEMENT WITH THE GFS ENSEMBLES.
THEREFORE WILL NOT MAKE MANY CHANGES AT THIS TIME.
SURFACE HIGH BUILDS IN BEHIND THE EXITING SYSTEM BUT THE MID LEVEL
PATTERN REMAINS MORE PROGRESSIVE WHICH KEEPS COLDEST AIR NORTH OF
THE AREA. COLD ADVECTION THU INTO FRI WILL HOLD TEMPERATURES BELOW
CLIMO BUT NOT SEVERAL CATEGORIES BELOW.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...VFR WILL SOON DETERIORATE TO MVFR/POSSIBLE IFR AND
PERSIST THROUGH THIS AFTERNOON AS A COLD FRONT BRINGS UNSETTLED
WEATHER. TOWARDS THE END OF THE TAF PERIOD...ANTICIPATE CONDITIONS
TO IMPROVE TO VFR.
FOR THE EARLY MORNING HOURS...MID CLOUDS WILL LOWER TO MVFR AS
ILLUSTRATED BY LATEST MODELS...JUST AHEAD OF AN APPROACHING
ARCTIC COLD FRONT SITUATED BETWEEN KAVL AND KCLT. COULD NOT
COMPLETELY RULE OUT CIGS LOWERING EVEN MORE TO IFR...HOWEVER
CONFIDENCE REMAINS TOO LOW. FOG DEVELOPMENT IS POSSIBLE...ESPECIALLY
WITH ANY RAINFALL. RAIN CHANCES SHOULD PEAK AROUND THE TIME OF THE
FRONTAL PASSAGE...GENERALLY 10Z INLAND AND 13-14Z COAST. BEHIND THE
FRONT...EXPECT MVFR CEILINGS TO PERSIST INTO THIS EVENING...WITH
LINGERING -RA POSSIBLE THROUGH EARLY AFTERNOON. BY THIS EVENING...
CLOUDS SHOULD BREAK...WITH INCREASINGLY GUSTY NORTH WINDS.
EXTENDED OUTLOOK...VFR WITH BREEZY CONDITIONS EXPECTED ON SUNDAY.
VFR EXPECTED ON MONDAY...WITH LOW PRESSURE BRINGING RAIN
TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...BIG CHANGES ARE COMING OVER THE NEXT 12-24
HOURS AS AN ARCTIC COLD FRONT MOVES ACROSS THE AREA. THE FRONT
ITSELF WILL MOVE ACROSS THE COASTAL WATERS LATE THIS MORNING...
SHIFTING OUR SOUTHWEST WINDS AROUND TO THE NORTH BUT WITHOUT ANY
IMMEDIATE INCREASE IN SPEED. THAT WILL WAIT UNTIL THIS EVENING
WHEN HIGH PRESSURE OVER THE CENTRAL PLAINS SURGES EAST AND BEGINS
TO PUSH VERY CHILLY AIR OFFSHORE. NORTH WINDS SHOULD INCREASE TO
25-30 KNOTS AFTER MIDNIGHT. MODELS SHOW WINDS AT 1000-1500 FT
ABOVE GROUND LEVEL REACHING 35 KNOTS...AND FOR THIS REASON A GALE
WATCH HAS BEEN ISSUED FOR THE POTENTIAL THESE WINDS WILL MIX DOWN
TO THE OCEAN SURFACE IN GUSTS LATE TONIGHT. THE COLD AIR GALE
EVENT WE HAD EARLIER THIS MONTH FEATURED WINDS ABOUT 5 KNOTS
STRONGER AT 1000-1500 FT ALTITUDE THAN WHAT IS EXPECTED
TONIGHT...SO IT IS NOT GUARANTEED WE WILL SEE GALE-FORCE GUSTS
ACTUALLY MEASURED AT THE GROUND/OCEAN SURFACE.
SEAS CURRENTLY ARE 4 FT OUT AT THE FRYING PAN SHOALS BUOY AND 2 FT
AT THE BUOY SOUTH OF THE MOUTH OF THE CAPE FEAR RIVER. SEAS SHOULD
NOT CHANGE APPRECIABLY UNTIL LATE THIS EVENING...BUT WILL REALLY
START TO BUILD AFTER MIDNIGHT IN RESPONSE TO THE INCREASING WIND
SPEEDS. DOMINANT WAVE PERIODS CURRENTLY AROUND 8 SECONDS SHOULD
SHORTLY CONSIDERABLY ONCE THE WINDS START CRANKING AFTER MIDNIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...STRONG NORTHERLY FLOW CONTINUES SUN WITH SOLID
SCA CONDITIONS FOR AT LEAST THE FIRST HALF OF THE DAY. COLD
ADVECTION AND PRESSURE GRADIENT START TO WEAKEN LATER IN THE DAY
WITH WINDS DROPPING UNDER 20 KT IN THE EVENING. WINDS VEER TO
NORTHEAST SUN NIGHT AND MON AS CENTER OF SURFACE HIGH MOVES OVER
EASTERN NORTH CAROLINA. WEAK COASTAL TROUGH STARTS TO DEVELOP LATER
MON AND MON NIGHT AS SURFACE HIGH BECOMES ELONGATED TO THE
NORTHEAST. NEARSHORE WINDS WILL REMAIN NORTHEAST BUT CLOSER TO 20 NM
VARIABLE OR EVEN SOUTHEAST WINDS MAY DEVELOP BEFORE THE END OF THE
PERIOD. GRADIENT REMAINS WEAK IN THE VICINITY OF THE TROUGH WHICH
WILL KEEP WIND SPEEDS CLOSER TO 10 KT MON NIGHT. SEAS 4 TO 7 FT TO
START THE PERIOD FALL TO 3 TO 5 FT SUN NIGHT AND CONTINUE TO DROP AS
WINDS VEER AND WEAKEN. BY THE END OF THE PERIOD SEAS WILL BE 2 TO 3
FT.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...LARGE AMOUNT OF UNCERTAINTY FOR THE PERIOD AS
FAR AS WIND DIRECTION IS CONCERNED. THINK SCA EVENT IS IN THE WORKS
TUE NIGHT OR WED AS STRENGTHENING LOW PRESSURE SYSTEM EMERGING FROM
THE NORTHERN GULF OF MEXICO TRAVELS UP THE EAST COAST. THE TRACK OF
THE LOW REMAINS THE STICKING POINT AND WILL DETERMINE WIND
DIRECTION. CONFIDENT STRONG EAST TO SOUTHEAST FLOW WILL DEVELOP ON
TUE BUT FROM THERE CONFIDENCE DROPS. AT THIS POINT THE FAVORED
SOLUTION IS A TRACK JUST INLAND OF THE COAST WHICH LEADS TO STRONG
SOUTHERLY FLOW BECOMING SOUTHWEST LATE TUE NIGHT. SOUTHWEST WINDS
VEER TO NORTHWEST ON WED AS THE COLD FRONT PUSHES OFF THE COAST AND
HIGH PRESSURE STARTS TO BUILD IN. THE ELEVATED WIND SPEEDS COMBINED
WITH THE VARYING DIRECTIONS WILL RESULT IN A VERY CHAOTIC SEA STATE
FOR MUCH OF THE PERIOD. SEAS BUILD TUE INTO TUE NIGHT...REACHING 5
TO 8 FT AT THEIR ZENITH...THEN SLOWLY SUBSIDING DURING WED AS
OFFSHORE FLOW DEVELOPS AND INCREASES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR AMZ250-
252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...SGL/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1232 AM EST SAT NOV 23 2013
.SYNOPSIS...
A STRONG ARCTIC COLD FRONT WILL CROSS THE AREA SATURDAY MORNING
FOLLOWED BY THE COLDEST TEMPERATURES OF THE SEASON. A SIGNIFICANT
RAIN EVENT APPEARS LIKELY FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1230 AM SATURDAY...ASIDE FROM RAISING FORECAST LOWS BY A
COUPLE DEGREES AND INCREASING FORECAST CLOUD COVERAGE...NO
SIGNIFICANT CHANGES ARE NEEDED. PREVIOUS DISCUSSION FROM 1030 PM
FOLLOWS...
LATEST SFC ANALYSIS PLACES THE ARCTIC FRONT IN THE NC MTNS. MOISTURE
ESPECIALLY IN THE LOW AND MID LEVELS WILL CONTINUE TO OVERSPREAD THE
FA OVERNIGHT. MAIN BELT OF MOISTURE WILL RESIDE ALONG THE IMMEDIATE
ARCTIC FRONT...AS WELL AS AFTER ITS PASSAGE. LATEST HRRR ILLUSTRATES
-SHRA ACTIVITY TO REACH AND/OR BREAKOUT ACROSS THE NW PORTIONS OF
THE FA AFTER MIDNIGHT...AND SLOWLY PUSH TO AND OFF THE COAST DURING
THE AM DAYLIGHT HOURS. ONCE THE ARCTIC FRONT CLEARS THE
MOUNTAINS...IT WILL PICK UP SPEED AND MOMENTUM AS IT TRACKS TO THE
EASTERN CAROLINAS BY DAYBREAK SATURDAY. HAVE BASICALLY KEPT CURRENT
POPS PEAKING IN THE GOOD CHANCE TO LIKELY CATEGORIES THROUGH
DAYBREAK SAT. STILL LOOKING AT RW- FOR PCPN TYPE...WITH NO THUNDER.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...A QUICK CHANGE IN THE TEMPERATURES IS ON TAP
STARTING SATURDAY MORNING AS A COLD FRONT WILL PUSH OFF THE COAST
AND BRING IN THE COLDEST AIR OF THE SEASON.
THE MODELS ARE ALL SHOWING PRECIPITATION ALONG THE FRONT AND JUST
BEHIND THE FRONT AS IT SWEEPS OFF THE COAST. THE LATEST 09 UTC
SREF IS SHOWING A 90% CHANCE OF MEASURABLE PRECIPITATION BUT THE
PROBABILITIES FOR GREATER THAN 0.10 INCHES IS AROUND 50%. SO THIS
IMPLIES PROBABILITIES WILL BE HIGH BUT QPF WILL BE LESS THAN
EARLIER ADVERTISE.
THE OTHER STORY WILL BE THE COLD AIR THAT WILL BE ADVECTING INTO
THE REGION. LOWS WILL DROP INTO THE MIDDLE 30S SATURDAY NIGHT AND
THE MIDDLE 20S ON SUNDAY NIGHT...AND THESE COLD TEMPERATURES WILL
THREATEN THE RECORD LOWS FOR THE 25TH ALONG THE COAST.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...COLD AND QUIET TO START THE PERIOD...BUT A
SIGNIFICANT STORM SYSTEM IS LOOKING MORE LIKELY TO IMPACT THE
REGION FOR THE MID-WEEK PERIOD.
ARCTIC HIGH PRESSURE WILL BE ENTRENCHED OVER THE AREA ON
MONDAY...AND WITH A VERY COLD MORNING FROM WHICH TO
RECOVER...SUNSHINE WILL ONLY HELP TEMPS RISE INTO THE 40S TO AROUND
50 ON MONDAY...OR ABOUT 15 DEGREES BELOW NORMAL. LOWS MONDAY NIGHT
WILL DROP TO BELOW CLIMO AS WELL...BUT DEVELOPING SOUTHERLY FLOW
WILL KEEP TEMPS MUCH WARMER THAN WHAT WILL BE EXPERIENCED AT THE
START OF THE PERIOD.
BIG CHANGES OCCUR THEREAFTER AS THE 5H PATTERN BECOMES HIGHLY
AMPLIFIED. CUTOFF SOUTHERN STREAM LOW ACROSS THE 4-CORNERS EJECTS
EASTWARD TOWARDS THE SOUTHEAST...WHILE A NORTHERN STREAM VORT MAX
DROPS ACROSS THE GREAT LAKES. IN A FLOW THAT IS NOT TOO FAST...THIS
IS A TYPICAL SETUP FOR A POTENTIAL COASTAL STORM AS THESE FEATURES
INTERACT ALONG THE COAST. THIS CASE APPEARS NO DIFFERENT...ALTHOUGH
TIMING AND INTENSITY DIFFERENCES STILL EXIST. THE ECM/CMC KEEP THE
SOUTHERN STREAM LOW MORE CLOSED AND AMPLIFIED...WHICH HELPS DEVELOP
A LOW IN THE GULF OF MEXICO WHICH WILL THEN RIDE UP THE EAST COAST.
THE GFS IS MORE PROGRESSIVE AND KEEPS THE LOW WELL OFFSHORE...BUT IS
NOTICEABLY EAST AND FASTER THAN MANY OF ITS ENSEMBLES. WILL FAVOR
FOR NOW THE ECM/CMC...BUT NOT FOCUS ON SPECIFICS SINCE THERE IS
STILL TEMPORAL AND SPATIAL UNCERTAINTY.
REGARDLESS...A -3SD 5H LOW IN THE GULF OF MEXICO IS A CLEAR SIGNAL
FOR STRONG CYCLOGENESIS...AND IT IS LIKELY THAT A LOW PRESSURE WILL
IMPACT THE LOCAL AREA BEGINNING TUESDAY NIGHT AND LASTING THROUGH
WEDNESDAY. AMPLE MOISTURE WILL BE PRESENT...COMMON OF COURSE WITH A
LOW FROM THE GULF OF MEXICO...AND MDT/HVY RAIN WILL OVERSPREAD THE
AREA...WITH CONSIDERABLE QPF POSSIBLE. ADDITIONALLY...IF THE INLAND
TRACK VERIFIES...THE COASTAL SECTIONS OF THE AREA WILL BE
WARM-SECTORED...HENCE CREATING A NON-ZERO SEVERE THREAT...WITH
STRONG LOW-LEVEL SHEAR EAST OF THE COASTAL/WARM FRONT. THE ONE THING
THAT DOES...NOT...APPEAR TO BE A PROBLEM WITH THIS EVENT WILL BE
WINTRY PRECIP. BY THE TIME COLD ENOUGH AIR WORKS INTO THE
CWA...MOISTURE WILL BE GONE. NEVERTHELESS...A SIGNIFICANT WEATHER
EVENT THE DAY BEFORE THANKSGIVING COULD LEAD TO WIDESPREAD TRAVEL
HEADACHES.
TEMPS TUE/WED WILL BE TRICKY AS A WEDGE SETUP WILL KEEP INLAND TEMPS
MUCH COOLER THAN THE COAST...AND A 10-15 DEGREE TEMP GRADIENT ACROSS
THE CWA IS POSSIBLE. THURS/FRI WILL BE DRY BEHIND THE DEPARTING
SYSTEM...BUT WELL BELOW NORMAL AS CAA DEVELOPS ON NORTH WINDS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...VFR WILL SOON DETERIORATE TO MVFR/POSSIBLE IFR AND
PERSIST THROUGH THIS AFTERNOON AS A COLD FRONT BRINGS UNSETTLED
WEATHER. TOWARDS THE END OF THE TAF PERIOD...ANTICIPATE CONDITIONS
TO IMPROVE TO VFR.
FOR THE EARLY MORNING HOURS...MID CLOUDS WILL LOWER TO MVFR AS
ILLUSTRATED BY LATEST MODELS...JUST AHEAD OF AN APPROACHING
ARCTIC COLD FRONT SITUATED BETWEEN KAVL AND KCLT. COULD NOT
COMPLETELY RULE OUT CIGS LOWERING EVEN MORE TO IFR...HOWEVER
CONFIDENCE REMAINS TOO LOW. FOG DEVELOPMENT IS POSSIBLE...ESPECIALLY
WITH ANY RAINFALL. RAIN CHANCES SHOULD PEAK AROUND THE TIME OF THE
FRONTAL PASSAGE...GENERALLY 10Z INLAND AND 13-14Z COAST. BEHIND THE
FRONT...EXPECT MVFR CEILINGS TO PERSIST INTO THIS EVENING...WITH
LINGERING -RA POSSIBLE THROUGH EARLY AFTERNOON. BY THIS EVENING...
CLOUDS SHOULD BREAK...WITH INCREASINGLY GUSTY NORTH WINDS.
EXTENDED OUTLOOK...VFR WITH BREEZY CONDITIONS EXPECTED ON SUNDAY.
VFR EXPECTED ON MONDAY...WITH LOW PRESSURE BRINGING RAIN
TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM SATURDAY...NO SIGNIFICANT CHANGES ARE NEEDED. PREVIOUS
DISCUSSION FROM 1030 PM FOLLOWS...
A RELAXED SFC PRESSURE GRADIENT TO PREVAIL LEADING UP TO THE PASSAGE
OF THE ARCTIC COLD FRONT DURING THE AM HRS OF SATURDAY...AFTER
DAYBREAK. THE SFC PRESSURE PATTERN WILL BE CONDUCIVE FOR THE CURRENT
WESTERLY WIND DIRECTION THAT WILL VEER TO THE NW BY DAYBREAK SAT IN
RESPONSE TO THE ARCTIC COLD FRONT CLIMBING AT THE DOORSTEPS OF THE
FORECAST AREA. SIGNIFICANT SEAS WILL HOLD IN THE 2 TO 4 FOOT
RANGE...WITH A 2 TO 3 FOOT EASTERLY SWELL AT 8 TO 10 SECOND PERIODS
DOMINATING THE OVERALL WAVE SPECTRUM ACROSS THESE WATERS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...THE MARINE WATERS WILL BEING GOING DOWN HILL
QUICKLY AS A STRONG ARCTIC COLD FRONT CROSSES THE WATER BEGINNING
SATURDAY MORNING. THIS WILL BRING STRONG COLD AIR ADVECTION OVER
THE WATERS AND WIND SPEEDS JUST BELOW GALE CONDITIONS. SMALL CRAFT
CONDITION ARE GIVE BEGINNING LATE SATURDAY AND THE WATERS MAYBE
APPROACHING GALE CONDITION BY SUNRISE SUNDAY FOR A FEW HOURS.
MARINERS ARE ADVISE TO MONITOR THE FORECAST FOR A POSSIBLE GALE
WARNING IF THEY ARE NEEDED. SEAS WILL RISE TO 6 TO 8 FEET BY SUNDAY
MORNING.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...QUIET MARINE CONDITIONS TO START THE PERIOD
WILL RAPIDLY DETERIORATE THROUGH MID-WEEK AS A COASTAL STORM WILL
POSSIBLY IMPACT THE AREA TUE/WED. HIGH PRESSURE NEAR THE AREA WILL
DRIFT E/NE THROUGH MONDAY...KEEPING WINDS LESS THAN 10 KTS AND
SHIFTING TO THE EAST THROUGH THE DAY. WINDS THEN INCREASE STEADILY
AS A COASTAL LOW IS EXPECTED TO DEVELOP AND MOVE UP THE COAST. THE
EXACT PLACEMENT AND TIMING OF THIS SYSTEM IS STILL IN QUESTION DUE
TO MODEL UNCERTAINTY...BUT EXPECT WINDS TO INCREASE FROM THE SE ON
TUESDAY...BEFORE SHIFTING TO THE SW...AND EVENTUALLY NW ON WEDNESDAY
AS THE LOW MOVES TO THE NE. WINDS SPEEDS WILL BE AROUND 15-20
KTS...POSSIBLY STRONGER...REGARDLESS OF DIRECTION DURING THIS TIME.
THIS WILL CREATE HAZARDOUS SEAS...WITH WAVE HEIGHTS RISING TO 4-7 FT
FROM SEVERAL DIFFERENT DIRECTIONS. A SMALL CRAFT ADVISORY IS
POSSIBLE TUESDAY AND WEDNESDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRH
NEAR TERM...DCH/TRA
SHORT TERM...DRH
LONG TERM...JDW
AVIATION...SGL/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1106 PM EST FRI NOV 22 2013
.SYNOPSIS...
A STRONG ARCTIC COLD FRONT WILL CROSS THE AREA SATURDAY MORNING
FOLLOWED BY THE COLDEST TEMPERATURES OF THE SEASON. A SIGNIFICANT
RAIN EVENT APPEARS LIKELY FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1015 PM FRIDAY...LATEST SFC ANALYSIS PLACES THE ARCTIC FRONT
ROUGHLY ALONG A LINE BETWEEN MWK-TNB-FQD-1A5-RHP. WHICH STILL
KEEPS IT TEMPORARILY HUNG-UP ACROSS THE APPALACHIAN MOUNTAINS.
MOISTURE ESPECIALLY IN THE LOW AND MID LEVELS WILL CONTINUE TO
OVERSPREAD THE FA OVERNIGHT. MAIN BELT OF MOISTURE WILL RESIDE
ALONG THE IMMEDIATE ARCTIC FRONT...AS WELL AS AFTER ITS PASSAGE.
LATEST HRRR ILLUSTRATES -SHRA ACTIVITY TO REACH AND/OR BREAKOUT
ACROSS THE NW PORTIONS OF THE FA AFTER MIDNIGHT...AND SLOWLY PUSH
TO AND OFF THE COAST DURING THE AM DAYLIGHT HOURS. ONCE THE ARCTIC
FRONT CLEARS THE MOUNTAINS...IT WILL PICK UP SPEED AND MOMENTUM AS
IT TRACKS TO THE EASTERN CAROLINAS BY DAYBREAK SATURDAY. HAVE
BASICALLY KEPT CURRENT POPS PEAKING IN THE GOOD CHANCE TO LIKELY
CATEGORIES THROUGH DAYBREAK SAT. STILL LOOKING AT RW- FOR PCPN
TYPE...WITH NO THUNDER.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...A QUICK CHANGE IN THE TEMPERATURES IS ON TAP
STARTING SATURDAY MORNING AS A COLD FRONT WILL PUSH OFF THE COAST
AND BRING IN THE COLDEST AIR OF THE SEASON.
THE MODELS ARE ALL SHOWING PRECIPITATION ALONG THE FRONT AND JUST
BEHIND THE FRONT AS IT SWEEPS OFF THE COAST. THE LATEST 09 UTC
SREF IS SHOWING A 90% CHANCE OF MEASURABLE PRECIPITATION BUT THE
PROBABILITIES FOR GREATER THAN 0.10 INCHES IS AROUND 50%. SO THIS
IMPLIES PROBABILITIES WILL BE HIGH BUT QPF WILL BE LESS THAN
EARLIER ADVERTISE.
THE OTHER STORY WILL BE THE COLD AIR THAT WILL BE ADVECTING INTO
THE REGION. LOWS WILL DROP INTO THE MIDDLE 30S SATURDAY NIGHT AND
THE MIDDLE 20S ON SUNDAY NIGHT...AND THESE COLD TEMPERATURES WILL
THREATEN THE RECORD LOWS FOR THE 24TH ALONG THE COAST.
RECORD LOWS - DECEMBER 24TH
ILM - 23 IN 1970.
FLO - 19 IN 1970.
CRE - 28 IN 2008
(NOTE RECORDS FOR NORTH MYRTLE BEACH/MYRTLE BEACH ARE FOR
1948-1956 AND 1988-PRESENT AND 1970 TEMPERATURES WAS NOT
RECORDED).
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...COLD AND QUIET TO START THE PERIOD...BUT A
SIGNIFICANT STORM SYSTEM IS LOOKING MORE LIKELY TO IMPACT THE
REGION FOR THE MID-WEEK PERIOD.
ARCTIC HIGH PRESSURE WILL BE ENTRENCHED OVER THE AREA ON
MONDAY...AND WITH A VERY COLD MORNING FROM WHICH TO
RECOVER...SUNSHINE WILL ONLY HELP TEMPS RISE INTO THE 40S TO AROUND
50 ON MONDAY...OR ABOUT 15 DEGREES BELOW NORMAL. LOWS MONDAY NIGHT
WILL DROP TO BELOW CLIMO AS WELL...BUT DEVELOPING SOUTHERLY FLOW
WILL KEEP TEMPS MUCH WARMER THAN WHAT WILL BE EXPERIENCED AT THE
START OF THE PERIOD.
BIG CHANGES OCCUR THEREAFTER AS THE 5H PATTERN BECOMES HIGHLY
AMPLIFIED. CUTOFF SOUTHERN STREAM LOW ACROSS THE 4-CORNERS EJECTS
EASTWARD TOWARDS THE SOUTHEAST...WHILE A NORTHERN STREAM VORT MAX
DROPS ACROSS THE GREAT LAKES. IN A FLOW THAT IS NOT TOO FAST...THIS
IS A TYPICAL SETUP FOR A POTENTIAL COASTAL STORM AS THESE FEATURES
INTERACT ALONG THE COAST. THIS CASE APPEARS NO DIFFERENT...ALTHOUGH
TIMING AND INTENSITY DIFFERENCES STILL EXIST. THE ECM/CMC KEEP THE
SOUTHERN STREAM LOW MORE CLOSED AND AMPLIFIED...WHICH HELPS DEVELOP
A LOW IN THE GULF OF MEXICO WHICH WILL THEN RIDE UP THE EAST COAST.
THE GFS IS MORE PROGRESSIVE AND KEEPS THE LOW WELL OFFSHORE...BUT IS
NOTICEABLY EAST AND FASTER THAN MANY OF ITS ENSEMBLES. WILL FAVOR
FOR NOW THE ECM/CMC...BUT NOT FOCUS ON SPECIFICS SINCE THERE IS
STILL TEMPORAL AND SPATIAL UNCERTAINTY.
REGARDLESS...A -3SD 5H LOW IN THE GULF OF MEXICO IS A CLEAR SIGNAL
FOR STRONG CYCLOGENESIS...AND IT IS LIKELY THAT A LOW PRESSURE WILL
IMPACT THE LOCAL AREA BEGINNING TUESDAY NIGHT AND LASTING THROUGH
WEDNESDAY. AMPLE MOISTURE WILL BE PRESENT...COMMON OF COURSE WITH A
LOW FROM THE GULF OF MEXICO...AND MDT/HVY RAIN WILL OVERSPREAD THE
AREA...WITH CONSIDERABLE QPF POSSIBLE. ADDITIONALLY...IF THE INLAND
TRACK VERIFIES...THE COASTAL SECTIONS OF THE AREA WILL BE
WARM-SECTORED...HENCE CREATING A NON-ZERO SEVERE THREAT...WITH
STRONG LOW-LEVEL SHEAR EAST OF THE COASTAL/WARM FRONT. THE ONE THING
THAT DOES...NOT...APPEAR TO BE A PROBLEM WITH THIS EVENT WILL BE
WINTRY PRECIP. BY THE TIME COLD ENOUGH AIR WORKS INTO THE
CWA...MOISTURE WILL BE GONE. NEVERTHELESS...A SIGNIFICANT WEATHER
EVENT THE DAY BEFORE THANKSGIVING COULD LEAD TO WIDESPREAD TRAVEL
HEADACHES.
TEMPS TUE/WED WILL BE TRICKY AS A WEDGE SETUP WILL KEEP INLAND TEMPS
MUCH COOLER THAN THE COAST...AND A 10-15 DEGREE TEMP GRADIENT ACROSS
THE CWA IS POSSIBLE. THURS/FRI WILL BE DRY BEHIND THE DEPARTING
SYSTEM...BUT WELL BELOW NORMAL AS CAA DEVELOPS ON NORTH WINDS.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...VFR EXPECTED THIS EVENING AS CONDITIONS BEGIN TO
DETERIORATE OVERNIGHT AND PERSIST THROUGH THE VALID TAF PERIOD AS
A COLD FRONTAL PASSAGE BRINGS UNSETTLED WEATHER...ALONG WITH
LOWERED CIGS AND PATCHY FOG.
LIGHT SHOWERS THAT MOVED ACROSS THE AREA EARLIER HAVE SINCE
DISSIPATED THOUGH LATEST OBS SHOW THAT RESIDUAL FOG AT KCRE
CONTINUES...CREATING MVFR ATTM. INTO THE OVERNIGHT HOURS...EXPECT
SOUTH-SOUTHWEST WINDS AOB 5 KTS. CLOUDS ACROSS THE AREA WILL
INCREASE AND CIGS WILL LOWER TO MVFR AS ILLUSTRATED BY LATEST
TIME-HEIGHT ANALYSIS AND FCST SOUNDINGS...JUST AHEAD OF AN
APPROACHING ARCTIC COLD FRONT. COULD NOT COMPLETELY RULE OUT CIGS
LOWERING EVEN MORE TO IFR...HOWEVER CONFIDENCE REMAINS LOW. WILL
ALSO MENTION THAT FOG IS POSSIBLE AS WELL...ESPECIALLY ASSOCIATED
WITH RAIN ACTIVITY...BUT EXPECT LOWERED RESTRICTIONS TO BE MORE
CORRELATED TO LOWERED CIGS. EXPECT RAIN CHANCES TO INCREASE AS WELL
JUST AHEAD AND ALONG THE FRONTAL BOUNDARY...WHICH WILL PUSH THROUGH
LATE OVERNIGHT INTO THE MORNING HOURS FROM WEST TO EAST. BEHIND THE
FRONTAL PASSAGE...EXPECT MVFR CONDITIONS TO PERSIST DUE TO LOW CIGS
THROUGH SATURDAY EARLY EVENING...WITH LINGERING ISOLATED AREAS OF
-RA POSSIBLE. WINDS WILL BECOME NORTHERLY AOB 10 KTS...WITH SLIGHTLY
HIGHER WINDS POSSIBLE ALONG THE COAST.
EXTENDED OUTLOOK...EXPECT BREEZY VFR CONDITIONS FOLLOWING FROPA ON
SUNDAY. VFR ON MONDAY. SHOWERS LIKELY ON TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM FRIDAY...A RELAXED SFC PRESSURE GRADIENT TO PREVAIL
LEADING UP TO THE PASSAGE OF THE ARCTIC COLD FRONT DURING THE AM
HRS OF SATURDAY...AFTER DAYBREAK. THE SFC PRESSURE PATTERN WILL BE
CONDUCIVE FOR THE CURRENT WESTERLY WIND DIRECTION THAT WILL VEER
TO THE NW BY DAYBREAK SAT IN RESPONSE TO THE ARCTIC COLD FRONT
CLIMBING AT THE DOORSTEPS OF THE FORECAST AREA. SIGNIFICANT SEAS
WILL HOLD IN THE 2 TO 4 FOOT RANGE...WITH A 2 TO 3 FOOT EASTERLY
SWELL AT 8 TO 10 SECOND PERIODS DOMINATING THE OVERALL WAVE
SPECTRUM ACROSS THESE WATERS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...THE MARINE WATERS WILL BEING GOING DOWN HILL
QUICKLY AS A STRONG ARCTIC COLD FRONT CROSSES THE WATER BEGINNING
SATURDAY MORNING. THIS WILL BRING STRONG COLD AIR ADVECTION OVER
THE WATERS AND WIND SPEEDS JUST BELOW GALE CONDITIONS. SMALL CRAFT
CONDITION ARE GIVE BEGINNING LATE SATURDAY AND THE WATERS MAYBE
APPROACHING GALE CONDITION BY SUNRISE SUNDAY FOR A FEW HOURS.
MARINERS ARE ADVISE TO MONITOR THE FORECAST FOR A POSSIBLE GALE
WARNING IF THEY ARE NEEDED. SEAS WILL RISE TO 6 TO 8 FEET BY SUNDAY
MORNING.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...QUIET MARINE CONDITIONS TO START THE PERIOD
WILL RAPIDLY DETERIORATE THROUGH MID-WEEK AS A COASTAL STORM WILL
POSSIBLY IMPACT THE AREA TUE/WED. HIGH PRESSURE NEAR THE AREA WILL
DRIFT E/NE THROUGH MONDAY...KEEPING WINDS LESS THAN 10 KTS AND
SHIFTING TO THE EAST THROUGH THE DAY. WINDS THEN INCREASE STEADILY
AS A COASTAL LOW IS EXPECTED TO DEVELOP AND MOVE UP THE COAST. THE
EXACT PLACEMENT AND TIMING OF THIS SYSTEM IS STILL IN QUESTION DUE
TO MODEL UNCERTAINTY...BUT EXPECT WINDS TO INCREASE FROM THE SE ON
TUESDAY...BEFORE SHIFTING TO THE SW...AND EVENTUALLY NW ON WEDNESDAY
AS THE LOW MOVES TO THE NE. WINDS SPEEDS WILL BE AROUND 15-20
KTS...POSSIBLY STRONGER...REGARDLESS OF DIRECTION DURING THIS TIME.
THIS WILL CREATE HAZARDOUS SEAS...WITH WAVE HEIGHTS RISING TO 4-7 FT
FROM SEVERAL DIFFERENT DIRECTIONS. A SMALL CRAFT ADVISORY IS
POSSIBLE TUESDAY AND WEDNESDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRH
NEAR TERM...DCH
SHORT TERM...DRH
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
330 AM CST SAT NOV 23 2013
.DISCUSSION...
MID LEVEL VORT CENTER STILL POISED TO SLIDE ACROSS THE MID STATE
THIS MORNING. STILL SEEING SOME DESCENT REFLECTIVITY RETURNS TO OUR
WEST ACROSS WESTERN TN AND NRN MS. NUMERICAL GUIDANCE IS QUITE LOW
WITH THE POPS BUT WILL GO AHEAD AND ADHERE TO CURRENT RADAR TRENDS
AND THE HRRR WHICH ALSO SUPPORTS SOME SHOWER ACTIVITY FOR THIS
MORNING. SO...FOR THIS MORNING WILL INCLUDE A SLIGHT CHANCE OF
SHOWERS. HRRR CLEARS THE ACTIVITY FROM THE MID STATE BY 18Z.
PARTIAL CLEARING WILL COMMENCE IN THE AFTERNOON.
CLEARING TO COMMENCE IN EARNEST BY EVENING AS A STRONG COLD SFC HIGH
CONTINUES TO BUILD SOUTHEASTWARD. TEMPS TO TODAY WILL WARM LITTLE AS
THE CAA AT 850 MB RAMPS UP. BY SUNDAY MORNING...SFC HIGH WILL STILL
BE OVER NRN MO. LOW TEMPS WILL REACH THE UPPER TEENS TO LOWER 20S
AND A NORTHERLY 10-15 MPH WIND WILL BE ONGOING. THIS WILL EQUATE TO
WINDCHILL READINGS OF 5 TO 10 DEGREES....QUITE COLD FOR LATE
NOVEMBER.
SUNDAY DURING THE DAY...COLD WEATHER WILL CONTINUE. NORTH WINDS OF
10 TO 15 MPH WILL COMBINE WITH HIGHS IN THE 30S TO PRODUCE WINDCHILL
READINGS ONLY IN THE 20S FOR THE AFTERNOON. COLD INDEED FOR YOUR
SUNDAY.
SUNDAY NIGHT...SOME PARTIAL HIGH CLOUDINESS WILL BEGIN TO RETURN
LATE AS A STORM SYSTEM STARTS DEVELOPING IN THE WESTERN GULF. THIS
SYSTEM WILL TRACK NORTHEAST AND BRING A CHANCE OF PRECIPITATION TO
THE MID STATE MONDAY NIGHT INTO TUESDAY. THE LATEST GFS SOLUTION IS
FURTHER SOUTH WITH THE TRACK AND KEEPS THE BULK OF THE MOISTURE
SOUTH OF MIDDLE TN. THE EURO SOLUTION HOWEVER...IS FURTHER NORTH
WITH THE MOISTURE. THUS...FOR THE FCST...POPS WILL BE KEPT DOWN INTO
THE CHANCE CATEGORY...WITH THE HIGHEST POPS GENERALLY SOUTH. AS FOR
THE PRECIP TYPE MON NIGHT AND TUESDAY...SOUNDINGS STILL SUPPORT A
RAIN AND SLEET MIX. THE DEEP MOISTURE/SUB FREEZING THERMAL
CONNECTION IS NOT IN FOCUS WITH THIS EVENT. THE EURO
SOLUTION...WHICH IS MORE BULLISH WITH THE MOISTURE...IS WARMER MON
NT AND SUPPORTS A MOSTLY RAIN EVENT. GFS...IN CONTRAST...IS DRIER
BUT COLDER. THEREFORE...WITHOUT A POSITIVE MOISTURE/SUBFREEZING
CONNECTION...WILL CONTINUE TO LEAN TOWARD A RAIN/SLEET MIX. THUS...I
WILL BE GOING ABOVE GUIDANCE FOR THE MON NIGHT MINIMUMS.
ON TUESDAY...THE LOWER LEVEL ISENTROPICALLY INDUCED PRECIP WILL BE
PULLING EAST. AT THAT TIME THE FOCUS WILL SHIFT TOWARD THE UPPER
LEVEL SYSTEM. LATEST RUNS BRING THE UPPER LOW EASTWARD ACROSS THE
PANHANDLE OF FL. THIS IS MUCH FURTHER SOUTH THAN PREVIOUS RUNS. WILL
THEREFORE LEAN TOWARD DECREASING THE RAIN/SNOW FCST FROM EARLIER FOR
TUES NT. FURTHERMORE...THE UPPER SYSTEM LOOKS WEAKER IN TERMS OF
MOISTURE EXPANSE AS A TRANSITION TOWARD ANY NEGATIVE TILT
ORIENTATION NOW LOOKS ABSENT.
ON WEDNESDAY...A RETURN TO MOSTLY SUNNY SKIES WILL BE IN STORE. COLD
BUT NOT TOO TERRIBLY COLD FOR THE REST OF THE WEEK. THANKSGIVING
WILL FEATURE MOSTLY CLEAR SKIES...LOWS IN THE 20S HIGHS IN THE 40S.
50 TO 55 DEGREES FOR HIGHS ON FRIDAY...THE BUSIEST SHOPPING DAY OF
THE YEAR...AS AN UPPER RIDGE AXIS DEVELOPS OVER THE SPINE OF THE MS
RIVER.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 47 22 36 23 / 20 05 0 0
CLARKSVILLE 44 18 33 20 / 20 05 0 0
CROSSVILLE 44 18 31 20 / 20 05 0 0
COLUMBIA 49 22 38 24 / 20 05 0 10
LAWRENCEBURG 50 22 38 24 / 20 05 0 10
WAVERLY 45 19 34 21 / 20 05 0 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1139 PM CST FRI NOV 22 2013
.UPDATE...
UPDATED FOR THE 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 743 PM CST FRI NOV 22 2013/
UPDATE...
UPDATED TO REDUCE RAIN CHANCES ACROSS THE EAST THIS EVENING.
DISCUSSION...
CURRENT RADAR TRENDS AND HRRR MODEL RUN INDICATING PRECIPITATION
HOLDING OFF ON DEVELOPMENT AND SPREADING EAST INTO NORTHEAST
MISSISSIPPI UNTIL AFTER 08Z TONIGHT. HAVE REDUCED RAIN CHANCES
ACCORDINGLY. ALL OTHER FORECAST PARAMETERS ARE CURRENTLY ON TRACK.
JAB
&&
.PREV DISCUSSION... /ISSUED 402 PM CST FRI NOV 22 2013/
CURRENTLY...
THE COLD FRONT IS NOW LOCATED FROM EASTERN OHIO...DOWN THROUGH
MIDDLE TENNESSEE...AND INTO CENTRAL MISSISSIPPI. NNW WINDS ARE
RELATIVELY STRONG WITH SUSTAINED 15-20 MPH WITH SOME GUSTS TO 25
MPH. STRONG CAA IS CURRENTLY TAKING PLACE JUST TO THE NORTH OF THE
MID-SOUTH...WITH WIDESPREAD 30S LOCATED ACROSS SOUTHERN MISSOURI.
TEMPERATURES WILL CONTINUE TO COOL THROUGH THIS EVENING WITH LOWS
BOTTOMING OUT IN THE UPPER 30S AND LOWER 40S.
ANOTHER VORT MAX WILL PUSH THROUGH THE MID-SOUTH
OVERNIGHT...TRIGGERING SOME SHOWERS OVER MOST OF THE MID-SOUTH
WITH RAIN CHANCES TAPERING OFF BY MID-MORNING ON SATURDAY. EXTREME
NORTHEAST ARKANSAS MAY SEE A BRIEF CHANCE OF SOME SLEET EARLY IN
THE MORNING ON SATURDAY.
TEMPERATURES DURING THE DAY ON SATURDAY WILL REMAIN COOL...WITH
HIGHS NEAR 50 DEGREES. THE COLDEST AIR THAT WE HAVE SEEN SINCE
LAST WEEK WILL MOVE INTO THE REGION AND STAY PUT THROUGH EARLY
NEXT WEEK. HIGH PRESSURE WILL CENTER OVER THE MID-SOUTH OVERNIGHT
ON SUNDAY...LOWERING TEMPERATURES INTO THE LOW 20S AND EVEN SOME
TEENS IN OUR NORTHERN COUNTIES UNDER CLEAR SKIES.
.SUNDAY THROUGH WEDNESDAY...
COLD AIR WILL REMAIN IN PLACE ON SUNDAY AFTERNOON...WITH HIGHS
ONLY REACHING INTO THE 30S IN WEST TENNESSEE AND NORTHEAST
ARKANSAS...WITH NORTH MISSISSIPPI IN THE LOW 40S. WITH THE COLD
AIR IN PLACE...A CUTOFF LOW WILL BEGIN TO MEANDER INTO THE MID-
SOUTH SUNDAY NIGHT...BRINGING MOISTURE INTO THE MAJORITY OF THE REGION.
MODEL GUIDANCE SUGGESTS THAT THE CUTOFF LOW WILL TAKE A MORE
SOUTHERN ROUTE...WHICH SHOULD DRAW MORE MOISTURE INTO THE REGION
EVEN WITH A DRY AIRMASS IN PLACE. THE ISSUE STILL LIES WITH
TIMING...AS THE GFS MOVES THE SYSTEM THROUGH A TAD BIT QUICKER
THAN THE ECMWF. THE SLOWER TIMING OF THE ECMWF KEEPS THE REGION IN
A WARM SECTOR LONGER...WHICH COULD OFFSET THE COOLING NEEDED FOR
ANY KIND OF MIXED PRECIPITATION.
THE FIRST CHANCE FOR ANY MENTIONABLE FROZEN PRECIPITATION STARTS
MONDAY MORNING FOR THE NORTHERN PARTS OF NORTHEAST ARKANSAS AND
WEST TENNESSEE...BUT ONLY A SLIGHT CHANCE ATTM. MODEL SOUNDINGS
TEMPERATURES ARE RIGHT ON THE EDGE OF BEING JUST COOL ENOUGH TO
POSSIBLY SUPPORT SOME SLEET/FREEZING RAIN. ONCE THE SUN GOES DOWN ON
MONDAY...A LARGER PORTION OF WEST TENNESSEE AND NORTHEAST ARKANSAS
WILL SEE A CHANCE OF SLEET AND OR SNOW DEPENDING ON THE AMOUNT
SATURATION IN THE HIGHER LEVELS OF THE ATMOSPHERE.
ON WEDNESDAY...ANOTHER BRIEF CHANCE OF SNOW WILL BE POSSIBLE IN
THE MORNING ACROSS A LARGER PART OF THE CWA AS THE UPPER LEVEL LOW
EXITS THE REGION. HIGH PRESSURE WILL BUILD INTO THE MID-SOUTH ON
THURSDAY INTO THE WEEKEND WITH TEMPERATURES WARMING INTO THE
UPPER 40S AND LOWER 50S FOR THANKSGIVING DAY.
AC3
&&
.AVIATION...
06Z TAF CYCLE
PRIMARILY MVFR CIGS AND VSBYS WILL PREVAIL THROUGH THE REMAINDER
OF THE NIGHT. LIGHT RAIN SHOWERS WILL CONTINUE TO OVERSPREAD THE
AREA FROM WEST TO EAST. THE GREATEST RAIN POTENTIAL WILL EXIST AT
KTUP...WHERE PREVAILED -RA IN LATEST TAF THROUGH SATURDAY MORNING.
WINDS WILL REMAIN STRONG AND GUSTY FROM THE NORTH BEHIND A COLD
FRONT THAT MOVED ACROSS THE AREA EARLIER TODAY.
LOW CIGS WILL QUICKLY IMPROVE AT ALL TERMINALS SATURDAY MORNING AS
A DRIER AIRMASS MOVES INTO THE REGION. SOUTHWEST FLOW ALOFT WILL
HELP TO MAINTAIN A BROKEN MID LEVEL CLOUD DECK THROUGH MUCH OF THE
DAY BUT CONDITIONS SHOULD REMAIN VFR FROM MID MORNING ONWARD.
GUSTY NORTH WINDS WILL CONTINUE THROUGH SATURDAY INTO SATURDAY
EVENING AT ALL SITES.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 40 48 25 40 / 50 10 0 0
MKL 39 48 20 37 / 30 10 0 0
JBR 36 46 23 36 / 50 0 0 0
TUP 45 52 24 43 / 50 20 10 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
852 AM MST SAT NOV 23 2013
.UPDATE...
ISSUED AT 852 AM MST SAT NOV 23 2013
COMPLEX SCENARIO THIS MORNING AND PRECIPITATION TYPE IS DETERMINED
BY THE POSITIONING OF SHALLOW COLD FRONT. HEAVY WET SNOW HAS
TAPERED OFF OVER EAST CENTRAL UTAH INTO WEST CENTRAL COLORADO. BUT
THE COLDER AIR NEVER REACHED THE SRN VALLEYS WITH RAIN AT DURANGO
AND MIXED RAIN/SNOW AT PAGOSA SPRINGS. ELECTED TO CANCEL THE
WEATHER WEATHER ADVISORY OR WINTER STORM WARNING FOR THE SRN
VALLEYS. HEAVY SNOW IS STILL POSSIBLE FOR THE SWRN COLORADO
VALLEYS...BUT NOT DURING THE NEXT SEVERAL HOURS.
PROMINENT CLOSED UPPER LOW OVER SRN CALIFORNIA WILL CONTINUE TO
SEND MOISTURE ACROSS THE REGION THROUGH SUNDAY. MOIST CONVEYOR
BELT IS NOTED OVER ARIZONA INTO SRN UTAH AND THIS ACTIVITY WILL
SLOWLY SHIFT EAST. PRECIPITATION TYPE REMAINS A CHALLENGE AND WILL
NEED TO MAKE AN ASSESSMENT...BUT ANY SNOW THAT FALLS WILL BE
CLOSER ALIGNED AS "SIERRA CEMENT" RATHER THAN THE TYPICAL POWDERY
FLUFF THAT WESTERN COLORADO TYPICALLY RECEIVES. FOR THE I70
CORRIDOR WHERE HEAVY WET SNOW FELL...CURRENT GUIDANCE SUGGEST THAT
THE COLDER SURFACE TEMPS WILL MODERATE AND THAT SNOW WILL CHANGE
OVER TO RAIN. NOT FULLY CONFIDENT WITH THIS SOLUTION BUT SEEMS
REASONABLE IF DEW POINTS CLIMB INTO THE MID 30S. LOTS OF FORECAST
QUESTIONS TODAY AS THIS WINTER STORM CONTINUES TO EVOLVE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 438 AM MST SAT NOV 23 2013
UPPER LEVEL LOW CONTINUES TO PUMP MOISTURE INTO OUR REGION...OVERRUNNING
COLD AIR AT THE SURFACE AND PRODUCING HEAVY WET SNOW. EXPECTING
TEMPS TO STAY SOMEWHAT HINDERED TODAY...AS CLOUD COVER WITH
INTERMITTENT BANDS OF SNOW CONTINUES AND NOW A COLD SNOW-COVERED
SURFACE IS PRESENT IN MANY AREAS. MANY NORMALLY ARID AREAS
RECEIVED NOTABLE AMOUNTS OF SNOW OVERNIGHT INCLUDING OVER 5 INCHES
JUST SOUTH OF MOAB AND OVER 3 INCHES AT GRAND JUNCTION AS OF
MIDNIGHT WITH LIGHT TO MODERATE SNOW CONTINUING SINCE. THAT BEING
SAID...SNOW LEVELS IN THE SOUTHERN CWA HAVE NOT REACHED VALLEY
FLOORS...KEEPING BOTH CORTEZ AND DURANGO IN RAIN INSTEAD OF
CHANGING OVER TO SNOW. NOT EXPECTING THIS TO CHANGE
TODAY...ESPECIALLY WITH WARM AIR CONTINUING TO PUMP UP INTO THE
REGION AT MID LEVELS.
CURRENT RADAR SHOWS BAND OF MODERATE SNOW FROM MOAB NORTHEAST TO
EAGLE. TRICKY ADVISORY/WARNING EVENTS THIS WEEKEND...AS SNOW IS
COMING IN WAVES. KEPT ADVISORIES OUT FOR THE GRAND VALLEY AND I-70
CORRIDOR TO EDWARDS UNTIL 11AM AS THE SNOW CONTINUES TO COME DOWN
IN LIGHT TO MODERATE RATES. CAN ALREADY SEE MORE LIGHT ECHOES
ON RADAR MOVING INTO THE NORTHERN SAN JUANS MTNS. FAVORING A
BLEND OF THE RAP AND NAM12 IN THE SHORT TERM AS THE RAP IS
IDENTIFYING SMALLER SCALE FEATURES BUT THE NAM IS BETTER ON
TIMING. THAT BEING SAID...THE BEST CHANCE OF SNOWFALL BY LATE
MORNING TODAY WILL BE DOWN IN THE FOUR CORNERS AREA. THIS
PRECIPITATION WILL GRADUALLY MOVE NORTHEAST THROUGHOUT THE
AFTERNOON AND IS EXPECTED TO REACH THE GRAND VALLEY AND I-70
CORRIDOR AGAIN BY THIS EVENING. DECIDED TO NOT PUT OUT ANY NEW
ADVISORIES AT THIS POINT SINCE SNOWFALL AMTS LOOK TO BE LESS THAN
THIS ONGOING FRI NIGHT/SAT MORNING EVENT...BUT DEFINITELY
SOMETHING THAT WE WILL BE KEEPING AN EYE ON. THE UPPER LEVEL JET
MOVES EAST TONIGHT...WHICH WILL BE ONE LESS FACTOR TO HELP
SMPLIFY THE SNOWFALL RATES TODAY. DYNAMICAL LIFTING AHEAD OF THE
LOW PRESSURE REMAINS DECENT FOR CONTINUATION OF SNOW PRODUCTION
THROUGH A WELL-SATURATED ENVIRONMENT.
THE FUN CONTINUES THROUGH SUNDAY AS THE UPPER LEVEL LOW FINALLY
ACCELERATES EAST OVER THE FOUR CORNERS BY SUNDAY EVENING. AS THE
LOW PROCEEDS EAST... WRAPAROUND MOISTURE AIDED BY DISTURBANCES
WITHIN THE SYSTEM WILL CONTINUE UNTIL THE ENTIRETY IS OUT OF THE
REGION FOR THE EARLY WORKWEEK.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 438 AM MST SAT NOV 23 2013
SHOULD NOTICE A DIMINISH IN PRECIPITATION BY SUNDAY NIGHT IN ALL
AREAS BUT THE CENTRAL TO EASTERN SAN JUAN MTNS UP INTO THE
GUNNISON VALLEY WHICH WILL LIKELY CONTINUE THROUGH MONDAY MORNING.
MONDAY THROUGH FRIDAY...ON MONDAY THE LOW CENTER WILL HAVE MOVED
TO NE NM AND INTO THE TX/OK PANHANDLES. NORTH TO NORTHEAST FLOW
ALOFT WILL SPREAD ACROSS THE AREA AND PCPN WILL BE CONFINED TO THE
CO SW MTS AND THE CONTINENTAL DIVIDE IN THE NORTHERN AND CENTRAL
CO MTS. CLEARING SKIES AND DRYING CONDITIONS WILL SPREAD EAST FROM
EASTERN UT. A SHARP RIDGE WILL BUILD OVER THE GREAT BASIN MON NIGHT
AND MOVE EAST...WITH THE UPPER RIDGELINE PASSING OVER EASTERN UT
AND WESTERN CO ON WED. THURSDAY AND FRIDAY THE PATTERN TRANSITIONS
FROM THE DOMINANT RIDGE OVER THE WEST TO THE NEXT BIG PACIFIC
TROUGH...WHICH THE MIDRANGE MODELS MOVE ONSHORE OVER NORTHERN
CALIFORNIA ON FRIDAY. SW WINDS ALOFT WILL INCREASE OVER THE
FORECAST AREA FRIDAY WITH INCREASING CLOUDS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 438 AM MST SAT NOV 23 2013
A SIGNIFICANT WINTER STORM WILL CONTINUE TO PRODUCE WIDESPREAD
MVFR CIGS AND VSBYS ACROSS WESTERN CO AND EASTERN UT THROUGH
SUNDAY. PERIODS OF IFR...AND BRIEF LIFR...ARE EXPECTED AT KEGE...
KRIL...KTEX...KGJT...KDRO...KCEZ...AND KPSO. THE MOUNTAINS AND
HIGH MOUNTAIN PASSES WILL BE FREQUENTLY OBSCURED.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR COZ018-019.
UT...WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR UTZ028.
WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR UTZ029.
&&
$$
UPDATE...PF
SHORT TERM...JAM
LONG TERM...JAM/CC
AVIATION...CC
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
440 AM MST SAT NOV 23 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 438 AM MST SAT NOV 23 2013
UPPER LEVEL LOW CONTINUES TO PUMP MOISTURE INTO OUR REGION...OVERRUNNING
COLD AIR AT THE SURFACE AND PRODUCING HEAVY WET SNOW. EXPECTING
TEMPS TO STAY SOMEWHAT HINDERED TODAY...AS CLOUD COVER WITH
INTERMITTENT BANDS OF SNOW CONTINUES AND NOW A COLD SNOW-COVERED
SURFACE IS PRESENT IN MANY AREAS. MANY NORMALLY ARID AREAS
RECEIVED NOTABLE AMOUNTS OF SNOW OVERNIGHT INCLUDING OVER 5 INCHES
JUST SOUTH OF MOAB AND OVER 3 INCHES AT GRAND JUNCTION AS OF
MIDNIGHT WITH LIGHT TO MODERATE SNOW CONTINUING SINCE. THAT BEING
SAID...SNOW LEVELS IN THE SOUTHERN CWA HAVE NOT REACHED VALLEY
FLOORS...KEEPING BOTH CORTEZ AND DURANGO IN RAIN INSTEAD OF
CHANGING OVER TO SNOW. NOT EXPECTING THIS TO CHANGE
TODAY...ESPECIALLY WITH WARM AIR CONTINUING TO PUMP UP INTO THE
REGION AT MID LEVELS.
CURRENT RADAR SHOWS BAND OF MODERATE SNOW FROM MOAB NORTHEAST TO
EAGLE. TRICKY ADVISORY/WARNING EVENTS THIS WEEKEND...AS SNOW IS
COMING IN WAVES. KEPT ADVISORIES OUT FOR THE GRAND VALLEY AND I-70
CORRIDOR TO EDWARDS UNTIL 11AM AS THE SNOW CONTINUES TO COME DOWN
IN LIGHT TO MODERATE RATES. CAN ALREADY SEE MORE LIGHT ECHOES
ON RADAR MOVING INTO THE NORTHERN SAN JUANS MTNS. FAVORING A
BLEND OF THE RAP AND NAM12 IN THE SHORT TERM AS THE RAP IS
IDENTIFYING SMALLER SCALE FEATURES BUT THE NAM IS BETTER ON
TIMING. THAT BEING SAID...THE BEST CHANCE OF SNOWFALL BY LATE
MORNING TODAY WILL BE DOWN IN THE FOUR CORNERS AREA. THIS
PRECIPITATION WILL GRADUALLY MOVE NORTHEAST THROUGHOUT THE
AFTERNOON AND IS EXPECTED TO REACH THE GRAND VALLEY AND I-70
CORRIDOR AGAIN BY THIS EVENING. DECIDED TO NOT PUT OUT ANY NEW
ADVISORIES AT THIS POINT SINCE SNOWFALL AMTS LOOK TO BE LESS THAN
THIS ONGOING FRI NIGHT/SAT MORNING EVENT...BUT DEFINITELY
SOMETHING THAT WE WILL BE KEEPING AN EYE ON. THE UPPER LEVEL JET
MOVES EAST TONIGHT...WHICH WILL BE ONE LESS FACTOR TO HELP
SMPLIFY THE SNOWFALL RATES TODAY. DYNAMICAL LIFTING AHEAD OF THE
LOW PRESSURE REMAINS DECENT FOR CONTINUATION OF SNOW PRODUCTION
THROUGH A WELL-SATURATED ENVIRONMENT.
THE FUN CONTINUES THROUGH SUNDAY AS THE UPPER LEVEL LOW FINALLY
ACCELERATES EAST OVER THE FOUR CORNERS BY SUNDAY EVENING. AS THE
LOW PROCEEDS EAST... WRAPAROUND MOISTURE AIDED BY DISTURBANCES
WITHIN THE SYSTEM WILL CONTINUE UNTIL THE ENTIRETY IS OUT OF THE
REGION FOR THE EARLY WORKWEEK.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 438 AM MST SAT NOV 23 2013
SHOULD NOTICE A DIMINISH IN PRECIPITATION BY SUNDAY NIGHT IN ALL
AREAS BUT THE CENTRAL TO EASTERN SAN JUAN MTNS UP INTO THE
GUNNISON VALLEY WHICH WILL LIKELY CONTINUE THROUGH MONDAY MORNING.
MONDAY THROUGH FRIDAY...ON MONDAY THE LOW CENTER WILL HAVE MOVED
TO NE NM AND INTO THE TX/OK PANHANDLES. NORTH TO NORTHEAST FLOW
ALOFT WILL SPREAD ACROSS THE AREA AND PCPN WILL BE CONFINED TO THE
CO SW MTS AND THE CONTINENTAL DIVIDE IN THE NORTHERN AND CENTRAL
CO MTS. CLEARING SKIES AND DRYING CONDITIONS WILL SPREAD EAST FROM
EASTERN UT. A SHARP RIDGE WILL BUILD OVER THE GREAT BASIN MON NIGHT
AND MOVE EAST...WITH THE UPPER RIDGELINE PASSING OVER EASTERN UT
AND WESTERN CO ON WED. THURSDAY AND FRIDAY THE PATTERN TRANSITIONS
FROM THE DOMINANT RIDGE OVER THE WEST TO THE NEXT BIG PACIFIC
TROUGH...WHICH THE MIDRANGE MODELS MOVE ONSHORE OVER NORTHERN
CALIFORNIA ON FRIDAY. SW WINDS ALOFT WILL INCREASE OVER THE
FORECAST AREA FRIDAY WITH INCREASING CLOUDS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 438 AM MST SAT NOV 23 2013
A SIGNIFICANT WINTER STORM WILL CONTINUE TO PRODUCE WIDESPREAD
MVFR CIGS AND VSBYS ACROSS WESTERN CO AND EASTERN UT THROUGH
SUNDAY. PERIODS OF IFR...AND BRIEF LIFR...ARE EXPECTED AT KEGE...
KRIL...KTEX...KGJT...KDRO...KCEZ...AND KPSO. THE MOUNTAINS AND
HIGH MOUNTAIN PASSES WILL BE FREQUENTLY OBSCURED.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR COZ018-019.
WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ007-
008.
WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR COZ022.
WINTER WEATHER ADVISORY UNTIL 8 AM MST THIS MORNING FOR COZ006.
WINTER STORM WARNING UNTIL 11 AM MST SUNDAY FOR COZ023.
UT...WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR UTZ028.
WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR UTZ022-029.
WINTER WEATHER ADVISORY UNTIL 8 AM MST THIS MORNING FOR UTZ027.
&&
$$
SHORT TERM...JAM
LONG TERM...JAM/CC
AVIATION...CC
AREA FORECAST DISCUSSION
NWS ALBANY NY
1023 AM EST SAT NOV 23 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL PLUNGE SOUTH THROUGH THE REGION THIS
AFTERNOON...AND TRIGGER LAKE EFFECT SNOW DOWNWIND OF THE EASTERN
GREAT LAKES...WITH SNOW SHOWERS AND SQUALLS IN MANY OTHER PARTS
OF THE REGION. HIGH PRESSURE WILL BUILD EAST FROM THE GREAT
PLAINS TONIGHT AND SLIDE OFFSHORE BY MONDAY...BRINGING WINDY AND
WINTER LIKE VERY COLD CONDITIONS. LATE MONDAY A WARM FRONT WILL
PUSH THROUGH THE REGION. ANOTHER WEAK COLD FRONT WILL FOLLOW ON
TUESDAY...AS A STORM EJECTS NORTHWARD ALONG THE ATLANTIC SEABOARD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1023 AM...THE ENTIRE AREA IS STILL PRECIP-FREE LATE THIS
MORNING...AS SHORT-WAVE RIDGING STILL IN CONTROL. HOWEVER...LAKE
ENHANCED SNOW STARTING TO DEVELOP ACROSS THE EASTERN LAKE ONTARIO
COUNTIES AND THE TUG HILL AHEAD OF AN ARCTIC BOUNDARY...WHICH IS
ALLOWING WESTERLY FLOW TO ALIGN WITH FURTHER COOLING ALOFT. HIGH
RES MODELS SUCH AS THE HRRR AND LOCAL WRF INDICATE BANDS OF LAKE
ENHANCED SNOW SHOWERS AND SQUALLS WILL DEVELOP EARLY THIS
AFTERNOON ACROSS THE WESTERN ADIRONDACKS...AND PUSH SOUTH AND EAST
ALONG THE ARCTIC FRONT LATER THIS AFTERNOON INTO THE EARLY
EVENING. BEST ACCUMULATIONS STILL LOOK TO BE ACROSS HERKIMER
COUNTY...WHERE MORE LAKE MOISTURE AND UPSLOPE COMPONENT WILL
ENHANCE SNOWFALL...ALTHOUGH A QUICK INCH OR TWO OF ACCUMULATION
WILL BE POSSIBLE ESPECIALLY FROM THE MOHAWK VALLEY NORTHWARD INTO
THE ADIRONDACKS. SCATTERED SNOW SHOWERS AND EVEN A FEW SQUALLS MAY
MAKE IT INTO THE CAPITAL REGION AND EASTERN CATSKILLS AROUND 4-6
PM. RAISED POPS IN THESE AREAS TO ACCOUNT FOR THIS POSSIBLE
ACTIVITY ALONG THE ARCTIC BOUNDARY.
AS THE ARCTIC FRONT MOVES THROUGH THE FLOW BEHIND IT WILL QUICKLY
TURN TO A 310 TO 320 ORIENTATION SO THE LAKE ENHANCED SNOW SHOWERS
AND SQUALLS WILL NOT LAST THAT LONG OVER NORTHERN HERKIMER COUNTY
AND HAVE LIMITED THE ACCUMULATIONS TO 3 TO 6 INCHES THROUGH THIS
EVENING. SNOW SQUALLS WILL LIKELY AFFECT AT LEAST PARTS OF THE
MOHAWK AND SCHOHARIE VALLEYS...AND THE EASTERN CATSKILLS AFTER THE
FLOW BECOMES 310 TO 320 DEGREES...BUT THIS IS NOT LIKELY TO OCCUR
UNTIL THIS EVENING.
TEMPS WILL NOT RISE VERY MUCH FROM THE MORNING LOWS DUE TO THE COLD
ADVECTION THAT WILL BE OCCURRING. HIGHS TODAY WILL BE BETWEEN THE
UPPER 20S AND 40 FOR MOST OF THE FORECAST AREA...WITH LOW OR MID 40S
OVER THE MID HUDSON VALLEY AND NORTHWEST CT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
ITS WINTER...FOR REAL AS TEMPS WILL RUN 10-20F BLO NORMALS NEXT
FEW DAYS. GUID SUITE GFS/NAM/GEM IN FAIRLY GOOD AGREEMENT DURING
MOST OF THIS PERIOD. 500HPA TROF AXIS SWINGS THROUGH REGION THIS
EVNG...ARCTIC CDFNT SURGES SOUTH THROUGH REST OF RGN...AND FRIGID
AIR FOR NOV POURS IN. CDFNT WILL TRIGGER SNOW SQUALLS AND -SHSN WITH
ITS PASSAGE THIS EVENING...THEN EVENT EVOLVES INTO LK EFFECT/NW-N
FLOW TRRN EVENT. LK EFFECT FOCUS QUICKLY SHIFTS W OF FCA BASED ON
NAM/LOCAL WRF DURING LATE EVNG HOURS. REST OF NIGHT UPSLOPE -SHSN
OVER GREENS...ADIRONDACKS AND CATSKILLS. BY SUNDAY CAP SETS UP OVER
LK ONT AT 4KFT BASED ON BUFKIT. THIS SHOULD DIMINISH ANY LK
EFFECT...AND FLOW IS SUCH IT WILL BE WEST OF FCA...AND NOT PENETRATE
VERY FAR INLAND WITHOUT HELP FROM TRRN OR OTHER LAKES.
WIND GRADIENT BECOMES VERY STRONG AT 12-14 MB ACRS NYS TNGT AND
SUN. BY SUNDAY MORNING FLOW IS PARALLEL UP TO 500 HPA. STRONG WINDS
WILL BUFFET THE REGION WITH NAM/GFS BDNRY LAYER WINDS 25-35
KTS...AND MET/MAV GUID WINDS 15-25MPH. WIND ADVISORIES MAY NEED TO
BE CONSIDERED FOR TNGT AND SUN. AWAY FM E GRTLKS SKIES WILL BCM PS
SUNDAY...BUT ANY SUN WILL HARDLY BE NOTICEABLE.
WINDS COMBINED WITH TEMPS IN SINGLE DIGITS TO TEENS...ONLY RISING
TO TEENS TO MID 20S SUNDAY WILL RESULT IN WIND CHILLS JUST ABV
ADVISORY VALUES. IT WILL BE QUITE A MAJOR CHANGE FM PAST FEW
WEEKS.
SUN NT THE MAIN 500HPA TROF AXIS SHIFTS EAST OF FCA AND LARGE SFC
HIGH SLIDES FM OH VLY TO DELMARVA WITH RIDGE N INTO QB. WINDS
WILL GRADUALLY DIMINISH AS RIDGE CRESTS OVR RGN BY DAYBREAK. WITH
CLEAR SKIES...SNOW COVER IN MANY PLACES N & W OF ALB...LONG NIGHT
AND WINDS BCMG LT AND VRBL...TEMPS WILL PLUNGE TO SINGLE DIGITS
TO TEENS WITH LOWS BELOW ZERO IN SOME PARTS OF ADIRONDACKS.
MONDAY SFC HIGH SLIDES OFFSHORE AND WMFNT PUSHES THRU RGN. MOST
OF THE GUID BRINGS INCRG CLOUDS...BUT LITTLE QPF. GIVEN THE
MAGNITUDE OF THE CD AIR THAT`S HERE...AND RESIDUAL LK
EFFECT...WILL CONSIDER KEEPING CHC -SHSN. MON NT A WK CDFNT AND
500HPA TROF PASS ACROSS RGN. THE GFS/GEM TRIGGERS ANOTHER ROUND OF
SCT -SHSN...AGAIN MAINLY N & W WHERE SOME LK ENHANCEMENT WILL
ASSIST....THE NAM MAINLY DRY.
BY TUES ALL GUID HAS A CDFNT DROPPING SE INTO THE GRTLKS AS 500HPA
CUTOFF DIGS INTO GRTLKS. MDLS BY TUES HAVE SOME SPREAD...BUT WERE
CONVERGING ON A SOLUTION....EVEN THOUGH THEY HAVE MADE A
SIGNIFICANT SHIFT FM MOST OF FRI GUID. GEM/ECMWF/HPC WEAKLY PHASE
THE N AND S STREAM 500HPA TROFS OVER THE EAST ON TUES...WITH EAST
COASTAL STORM DEEPENING AND MOVING NE THROUGH GA/CAROLINA PIEDMONT
BEFORE MOVING JUST OFFSHORE AND NORTHWARD TO LONG ISLAND NY.
OPERATIONAL GFS TAKES THIS SYSTEM OUT TO SEA LARGELY S OF FCA..AND
IS NOW AN OUTLIER...EVEN TO ITS OWN ENSEMBLE...WHICH IS COALESCING
AROUND A FEW CAMPS...QPF OF EITHER 0.1...1.0 AND 1.5 INCHES LIQ.
MOST MEMBERS START WITH AND INCH OR TWO OF SNOW CHANGE MOSTLY TO
RAIN. 4 OR 5 ARE STILL MOSTLY SNOW...BUT ONLY ONE OF THE 1.0 QPF
MEMBERS IS ALL SNOW. MOST HAVE A QPF OF 1-1.5 INCHES LIQ.
LATE TUES MIX PCPN WILL OVERSPREAD RGN FM S TO N...CHANGING
QUICKLY TO RAIN.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
COASTAL STORM IS OFF NJ COAST WED MORNING....500HPA TROF SWINGS
OFFSHORE...AS DOES STORM...WITH PCPN ENDING FM W TO E DURING THE
MORNING. ANOTHER ARCTIC HIGH BUILDS TWRD RGN FM ONT/QB WED NT INTO
THANKSGIVING. WINDS WILL BE BRISK AGAIN DURING THIS PERIOD AND
TEMPS WELL BLO NORMAL. WITH N-NW FLOW LK RESPONSE WILL BE LIMITED
AND WELL WEST OF AREA. SOME SCT UPSLOPE -SHSN WILL BE AROUND.
THE WEEK WILL END WITH LARGE SFC HIGH PRESSURE OVER EASTERN PARTS
OF NATION...BUT SIGNIFICANT 500HPA TROF OVER NE AND E GRTLKS. THIS
TROF WILL LIKELY ENHANCE LK EFFECT RESPONSE...MAINLY W OF
FCA...BUT SOME -SHSN OVER W REACHES OF FCA. MOST OF REGN WILL BE
COLD AND DRY. TEMPS WILL BE WELL BLO NORMAL AND MORE TYPICAL OF
JANUARY. WILL POPULATE WITH HPC MIDNIGHT GRIDS.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
MAINLY VFR CONDITIONS EXPECTED AT THE KGFL/KALB/KPSF TAF SITES TODAY
WITH NO PCPN FCST. OCCASIONAL MVFR CONDITIONS WILL STILL OCCUR AT
KGFL/KALB/KPSF UNTIL AROUND 15Z. WESTERLY SURFACE WINDS WILL BLOW AT
12 TO 15 KTS WITH GUSTS OF 20 TO 25 KTS.
LATE IN THE DAY AN ARCTIC COLD FRONT WILL MOVE THROUGH AND MAY BE
ACCOMPANIED BY SCATTERED SNOW SHOWERS AND POSSIBLY HEAVIER SNOW
SQUALLS AT THE TAF SITES...ESP AFTER 22Z/SAT. THIS COULD BRING
VSBY/CIG REDUCTIONS INTO THE IFR/LIFR RANGE...ESP AT KGFL/KALB AND
KPSF WELL INTO THE EVENING. FOR NOW HAVE ONLY INDICATED VCSH IN THE
TAF FORECASTS FOR KGFL/KALB/KPSF. SURFACE WINDS WILL PICK UP EVEN
MORE AFTER THE FRONTAL PASSAGE WITH GUSTS UP TO AROUND 30 KTS
POSSIBLE...ESPECIALLY AT KALB/KPSF.
OUTLOOK...
SUNDAY: MODERATE OPERATIONAL IMPACT. WINDY.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT.BREEZY NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
TUESDAY NIGHT: HIGH OPERATIONAL IMPACT. RA/SN LIKELY.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS.
A SERIES OF COLD FRONTS WILL BRING LIGHT PRECIPITATION TO THE AREA
OVER THE WEEKEND. HEAVIEST LIQUID EQUIVALENT PRECIPITATION WILL BE
OVER THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY WHERE 0.10
TO 0.33 INCHES MAY FALL...MAINLY AS SNOW. LITTLE RIVER RESPONSE IS
EXPECTED. MAINLY DRY AND WEATHER IS EXPECTED FOR MONDAY AND
TUESDAY.
THE FRIGID AIR MASS ON SUNDAY WILL ALLOW ICE TO BEGIN TO FORM ON
SHALLOWER LAKES AND RIVERS SUNDAY INTO EARLY NEXT WEEK.
TUESDAY INTO WEDNESDAY A COASTAL STORM COULD BRING 1 TO 2 INCHES
OF RAIN TO MUCH OF THE REGION...RESULTING IN SIGNIFICANT WITHIN
BANK RISES.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ032.
LAKE EFFECT SNOW ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
SUNDAY FOR NYZ038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...GJM/JPV
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...GJM
HYDROLOGY...SNYDER/NAS
AREA FORECAST DISCUSSION
NWS MIAMI FL
1004 AM EST SAT NOV 23 2013
.UPDATE...
LATEST SURFACE ANALYSIS SHOWS WEAK FRONTAL SYSTEM APPROACHING
NORTHERN FLORIDA AT THIS TIME. THIS SYSTEM WILL NEVER REALLY MAKE
IT PASSED SOUTH FLORIDA BUT RATHER BY PASS THE REGION TO THE NORTH
TONIGHT WITH WINDS PICKING UP BEHIND IT FROM THE NORTH TOMORROW AS
DESCRIBED BELOW. AHEAD OF IT TODAY, SATELLITE IMAGERY AND SURFACE
ANALYSIS SHOW SUBTLE CONVERGENCE LINE CUTTING ACROSS THE NEAR
SHORE MIAMI DADE WATERS AND ACROSS MIAMI DADE AND COLLIER COUNTIES
BETWEEN TAMIAMI TRAIL AND ALLIGATOR ALLEY. NORTH OF THESE ROAD
LAND MARKS AREA DEW POINTS MOSTLY IN THE 60S AND SOUTH OF THEM IN
THE LOW 70S. BLENDED GPSMET/AMSU SATELLITE BASED PRODUCT ALSO
SHOWS PRECIPITABLE WATER VALUES WELL ABOVE NORMAL PARTICULARLY
ACROSS SOUTHERN SECTIONS OF CWA DESPITE THE FACT THIS MORNING
SOUNDING IS NOT AS SATURATED AS LAST THREE WERE. WHAT THIS MORNING
SNDG SHOWED SOMEWHAT BETTER THAN LAST COUPLE OF DAYS WAS STEEPER
LOW LEVEL LAPSE RATES. GIVEN THERE IS A CHANCE OF INLAND AREAS
WARMING INTO THE LOWER TO MID 80S INTO THIS AFTERNOON DESPITE
INCREASING CLOUDINESS PARAMETERS SUPPORT A SLIGHT CHANCE OF A
THUNDERSTORM.
ENSEMBLE OF LOCAL HIGH RES MODELS HINT AT THIS ACROSS AREAS SOUTH
OF ALLIGATOR ALLEY AS WE HEAD IN THE AFTERNOON AND EARLY EVENING.
HOWEVER, THE HRRR DOES NOT REFLECT THIS. GIVEN THIS, INCREASED
RAIN CHANCES A BIT TO AROUND 30% AND MENTIONED A SLIGHT CHANCE OF
A THUNDERSTORM THIS AFTERNOON PARTICULARLY ACROSS AREAS SOUTH OF
ALLIGATOR ALLEY AWAY FROM THE EAST COAST.
NO MAJOR CONCERNS WITH ANY ACTIVITY THAT MANAGES TO DEVELOP TODAY
OTHER THAN THE SLIGHT RISK OF A LIGHTNING STRIKE ACROSS THE
AFOREMENTIONED AREAS.
&&
.PREV DISCUSSION... /ISSUED 614 AM EST SAT NOV 23 2013/
AVIATION...
OUTSIDE OF A FEW SHOWERS SPREADING ASHORE ALONG THE EAST COAST
THAT HAVE THE POTENTIAL OF BRIEFLY ALTERING CIGS/VSBYS TO MVFR
LEVELS...VFR CONDITIONS WILL PREVAIL WITH LIGHT EASTERLY WINDS.
PREV DISCUSSION... /ISSUED 302 AM EST SAT NOV 23 2013/
.DRIER WEATHER FOR FIRST HALF OF THIS WEEKEND...BEFORE INCREASED
MOISTURE ALONG WITH WINDY CONDITIONS FOR SECOND HALF OF THE
WEEKEND...
SHORT TERM...
AN OLD FRONTAL BOUNDARY WILL SLOWLY DISSIPATE THROUGH TONIGHT OVER
THE FLORIDA KEYS...AS HIGH PRESSURE OVER THE MID ATLANTIC STATES MOVES
EAST INTO THE ATLANTIC WATERS. THIS WILL KEEP AN EASTERLY WIND
FLOW OVER SOUTH FLORIDA TODAY INTO TONIGHT ALONG WITH MOSTLY DRY
WEATHER. THE ONLY CHANCE OF SEEING A SHOWER OR TWO IS OVER THE
EAST COAST METRO AREAS AND THE ATLANTIC WATERS. SO WILL KEEP A
SLIGHT CHANCE OF POPS IN FOR THE EAST COAST METRO AREAS THROUGH
TONIGHT WHILE REST OF SOUTH FLORIDA REMAINS DRY.
THE HIGH WILL CONTINUE TO MOVE FURTHER EAST INTO THE ATLANTIC WATERS
ON SUNDAY...AS A STRONG COLD FRONT MOVES SOUTHWARD FROM THE SOUTHEASTERN
UNITED STATES AND THROUGH SOUTH FLORIDA. THIS WILL ALLOW FOR THE
WIND FLOW TO BACK FROM A EASTERLY DIRECTION TODAY TO A NORTHERLY
FLOW ON SUNDAY...AS THE WINDS INCREASE FROM 10 TO 15 MPH TODAY TO
WINDY CONDITIONS LATE SUNDAY. THIS FRONT WILL ALSO ALLOW SCATTERED
SHOWERS OVER THE EAST COAST METRO AREAS ON SUNDAY...WITH ISOLATED
SHOWERS ELSEWHERE OVER SOUTH FLORIDA.
THE THREAT OF RIP CURRENTS WILL ALSO CONTINUE ALONG THE EAST COAST
BEACHES OF SOUTH FLORIDA THIS WEEKEND INTO EARLY NEXT WEEK.
LONG TERM...
THE STRONG COLD FRONT WILL CONTINUE TO MOVE INTO THE FLORIDA KEYS
EARLY NEXT WEEK...AS A STRONG HIGH PRESSURE MOVES EAST FROM THE
CENTRAL UNITED STATES INTO THE MID ATLANTIC STATES. THIS WILL KEEP
THE PRESSURE GRADIENT OVER SOUTH FLORIDA TIGHT ALLOWING FOR BREEZY
TO WINDY NORTHERLY WINDS ALONG WITH ISOLATED TO SCATTERED SHOWERS.
THE STRONG HIGH PRESSURE WILL THEN MOVE EAST INTO THE ATLANTIC
WATERS MIDDLE OF NEXT WEEK...AS LOW PRESSURE DEVELOPS IN THE
NORTHERN GULF OF MEXICO AND MOVES NORTHEAST INTO THE SOUTHEASTERN
UNITED STATES. THIS SHOULD ALLOW FOR ANOTHER STRONG COLD FRONT TO
MOVE THROUGH THE AREA THROUGH THE MIDDLE OF NEXT WEEK BRINGING IN
DEEP TROPICAL MOISTURE TO THE AREA. ALTHOUGH MUCH OF THE FORCING
WILL REMAIN NORTH OF OUR AREA...THERE IS A CHANCE OF A SQUALL LINE
DEVELOPING AHEAD OF THE FRONT AS IT APPROACHES AND MOVES THROUGH
FROM WEST TO EAST. THIS FEATURE WILL NEED TO BE MONITORED OVER THE
WEEKEND AND INTO NEXT WEEK AS THIS SYSTEM EVOLVES WEST OF OUR AREA
AND CONFIDENCE IN MORE OF THE DETAILS INCREASE.
AVIATION...
OUTSIDE OF A FEW SHOWERS SPREADING ASHORE ALONG THE EAST COAST
THAT HAVE THE POTENTIAL OF BRIEFLY ALTERING CIGS/VSBYS TO MVFR
LEVELS...VFR CONDITIONS WILL PREVAIL WITH LIGHT EASTERLY WINDS.
MARINE...
THE WINDS WILL BE NORTHEAST TO EAST AT 10 TO 15 KNOTS TODAY INTO
TONIGHT...EXCEPT FOR MIAMI-DADE ATLANTIC WATERS WHERE THEY WILL
BE 15 TO 20 KNOTS THIS MORNING BEFORE DECREASING TO 10 TO 15 KNOTS
THIS AFTERNOON. THE WINDS WILL THEN BACK TO A NORTHERLY DIRECTION
AND RAPIDLY INCREASING TO NEAR GALE FORCE CONDITIONS BY SUNDAY
NIGHT. THIS WILL ALLOW FOR THE ATLANTIC SEAS TO BE 3 TO 5 FEET
TODAY INTO TONIGHT...BEFORE RAPIDLY INCREASING TO 11 TO 13 FEET BY
SUNDAY NIGHT. FOR THE GULF SIDE...THE SEAS WILL REMAIN 2 FEET OR
LESS TODAY INTO TONIGHT BEFORE RAPIDLY INCREASING TO 4 TO 6 FEET
NEAR-SHORE TO 6 TO 8 FEET OFFSHORE SUNDAY NIGHT. SO WILL HAVE A
SCA UP FOR THE ATLANTIC WATERS TODAY WITH A SCEC UP FOR REST OF
SOUTH FLORIDA WATERS.
WE WILL ALSO CONTINUE TO MONITOR THE WINDS AND SEAS FOR SUNDAY
AFTERNOON INTO SUNDAY NIGHT TO SEE IF A SCA OR EVEN A GALE WARNING
WILL BE NEEDED IN LATER FORECAST FOR ALL OF THE LOCAL WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 70 79 69 / 20 20 40 40
FORT LAUDERDALE 83 72 80 73 / 30 30 40 40
MIAMI 84 71 81 72 / 30 30 40 40
NAPLES 84 66 82 64 / 20 20 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...52/PS
AVIATION/RADAR...23/SK
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
531 AM CST Sat Nov 23 2013
.SHORT TERM...(Today and Tonight)
Issued at 346 AM CST SAT NOV 23 2013
Regional radar indicates a few echoes of light precipitation over
eastern Kansas. At this time expect those echoes to represent some
mid to high based precipitation, occurring at roughly 10 to 12 kft,
where RAP soundings indicate the lowest level of saturation. Below
that level, soundings indicate very dry air, which will preclude any
of the precipitation from reaching the surface.
The cold weather will continue across the area through the rest of
the weekend as cold northerly air continues to filter into the
Central Plains. The major culprit for this abnormally cold period is
an incredibly anomalous surface ridge located right on the Canadian
border with North Dakota. Currently, observations in far southern
Canada indicated roughly 1050 mb for the surface ridge and
temperatures in the -15 to -20 range. This ridge will slide
south/southeast and become centered over northern Missouri late
Saturday night into early Sunday morning. NAM has the surface ridge
approaching 1050 mb even as it becomes centered over the KC Metro
Sunday morning. Should the ridge maintain 1045 to 1050 mb as it
moves into the KC Metro its anomaly would carry nearly 4 standard
deviations from the seasonal normal, an incredible value.
Ahead of this ridge, cold air will continue to move into northern
and central Missouri causing temperatures on Saturday to remain
extremely chilly, with highs generally remaining in the lower to
middle 20s along and north of Interstate 70, with perhaps a few
areas south of Interstate 70 reaching the lower 30s.
As the aforementioned ridge moves overhead Saturday night the skies
will clear and winds will go calm, providing an incredible
opportunity for the surface to radiate outward. The result will be
record - or at the very least - near record temperatures for Sunday
morning across all of eastern Kansas and northern/central Missouri.
Even though the source region of this ridge demonstrates
temperatures well below 0 the lack of snow cover across areas north
of the forecast area will allow the airmass to modify. At this time
we can expect temperatures along and north of Interstate 70 to be in
the single digits - near zero degrees - Sunday morning, with areas
along Interstate 70 being near 10 degrees, and areas south of the
interstate being in the 10 to 15 degree range (See Climate portion
of the AFD for record lows for 11/24 in the KC Metro and St.
Joseph). Wind chills for Sunday morning will closely resemble the
morning lows, since the ridge being parked overhead will generally
prevent much in the way of surface flow, but ironically the coldest
wind chills Sunday morning could occur south of Interstate 70 where
light easterly winds in combination with the cold temperatures could
bring wind chill values to near zero. Only a modest diurnal warming
can be expected for Sunday as sunshine and perhaps the beginning of
southerly return flow could aid in getting the temperatures back
near the middle 30s by Sunday afternoon.
Very little - if any - relief from the cold temperatures are
expected through the early part of next week. In fact, after
Monday`s "warming" trend back into the lower 40s, expect another
cold front to blast through the area pulling temperatures back into
the 20s and 30s for Tuesday. At this time will continue a dry
forecast into the early part of the week, but there is a hint that
there could be some extremely light snowfall on Sunday night into
Monday morning. Southerly return flow late Sunday could usher a very
tiny amount of low level moisture into the area and spread it over
the aforementioned very cold surface temperatures. With a southern
stream cutoff low over the 4 Corner region, and a northern stream
long wave trough gently sagging southward into the area there could
be some ascent interaction with the moisture, however at this point
it was very difficult to even find modest lift. So, as previously
mentioned, have gone with a dry forecast for Sunday night, but
upcoming shifts will need to monitor the chances for very light,
likely non-accumulating, snow for Sunday night into Monday morning.
.LONG TERM...(Sunday through Friday)
Issued at 346 AM CST SAT NOV 23 2013
For Tuesday, and through the rest of the week, cool and dry
conditions are expected to prevail. Medium range operational and
ensemble models all point at Tuesday arriving with a trough swinging
through the center of the nation. Below the base of the trough a
cutoff low --currently noted spinning over Southern California--
will be phasing with the larger synoptic trough. Models continue to
show strong agreement that the cutoff low, even as it phases into
the base of trough, will stay south of Kansas and Missouri as it
transits the nation, thus allowing still more cold dry Canadian air
to slip south into the Plains States as a northwest flow prevails.
However, by late in the work week Tuesdays prevailing trough will
have pivoted fare to our east, and with another shortwave trough
expected to drop into the West Coast the flow across the center of
the nation should transit to more of a zonal flow across the Plains,
thus allowing a little moderation in our temperatures for the tail
end of the week. Thus, at this time, dry weather is expected, with
highs in the 30s prevailing Tuesday and Wednesday, creeping into the
40s for Friday and Saturday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 529 AM CST SAT NOV 23 2013
No change to existing aviation forecast. Expect winds to be light and
variable tonight.
&&
.CLIMATE...
Issued at 346 AM CST SAT NOV 23 2013
Record lows for November 24...
Value Date
Kansas City 9 11/24/1950
St. Joseph 9 11/24/1950
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Leighton
LONG TERM...Cutter
AVIATION...Leighton
CLIMATE...Leighton
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
521 AM CST SAT NOV 23 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CST SAT NOV 23 2013
1050 MB ARCTIC HIGH PRESSURE CENTERED NEAR MINOT ND THIS MORNING
WILL DROP SOUTH THROUGH THE UPPER MISSOURI RIVER BASIN AND BE
CENTERED NEAR KANSAS CITY BY 12Z SUNDAY. AN ARCTIC COLD FRONT WILL
BACK PART WAY INTO THE FCST AREA THIS MORNING AND THEN LIFT NORTH
A BIT TONIGHT. A BANK OF STRATUS DEVELOPING BETWEEN
PHILIP...WINNER AND AINSWORTH IS EXPECTED TO EXPAND WEST AND
SOUTH...PERHAPS TO INTERSTATE 80 BY 15Z THIS MORNING.
THE MODELS APPEAR TO BE OVERFORECASTING THIS CLOUD COVER AND THIS IS
TYPICAL WITH FRESH SNOW COVER. MID AND HIGH LEVEL CLOUDINESS BLOWING
OFF FROM THE SWRN U.S. UPPER LEVEL LOW IS EXPECTED TO CONTINUE
ACROSS THE SRN HALF OF THE FCST AREA TODAY AND TONIGHT AND THE BANK
OF STRATUS SHOULD SLOWLY ERODE THIS AFTERNOON ACROSS NCNTL NEB. NOTE
THE RAP13 HANGS THE STRATUS ACROSS VALENTINE ALL DAY THROUGH 00Z.
FCST ERRORS WITH CLOUD COVER COULD BE LARGE TODAY AND TONIGHT.
ALL OF THIS SUGGESTS TEMPS WILL REMAIN BELOW FREEZING ACROSS ALL OF
THE FCST AREA TODAY WITH TEENS IN THE NORTHEAST TO NEAR 30 ACROSS
THE WEST AND SOUTHWEST WHERE THE ARCTIC FRONT WILL NOT REACH. LOWS
TONIGHT SHOULD FALL INTO THE TEENS AND SINGLE DIGITS WITH THE
COLDEST LOWS IN THE NORTHEAST. A LOW LEVEL JET/STRONG RETURN FLOW
AROUND THE ARCTIC HIGH SETS UP ACROSS WRN NEB TONIGHT WHICH SHOULD
LIMIT LOWS TO THE TEENS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 309 AM CST SAT NOV 23 2013
PERIOD WILL BE DOMINATED BY A LARGE BLOCKING RIDGE OF UPPER LEVEL
HIGH PRESSURE ACROSS THE NORTHERN ATLANTIC. THIS WILL CONTINUE TO
SUPPORT DEEP TROUGHING ACROSS THE HUDSON BAY AREA...WITH SHOTS OF
COLD ARCTIC AIR MOVING SOUTHEAST ACROSS CANADA INTO THE NORTHERN
AND EASTERN UNITED STATES ON THE WESTERN/SOUTHWESTERN SIDE OF THE
DEEP TROUGH. IT APPEARS THAT OUR AREA WILL BE ON THE SOUTHWEST
EDGE OF THESE ARCTIC AIR INTRUSIONS. IN FACT...WESTERN AND
SOUTHWEST NEBRASKA MAY STAY WEST OF THE ARCTIC AIR AND BE
DOMINATED BY A PACIFIC AIRMASS. THE ECMWF IS ADVERTISING A
POTENTIAL CHINOOK DOWNSLOPE EVENT BOTH WEDNESDAY AND
FRIDAY...WHICH COULD BOOST TEMPERATURES INTO THE 50S. WILL NOT
JUMP ONTO THIS SOLUTION FULLY...BUT WILL TREND TEMPS UP A DEGREE
OR TWO. OVERALL THE PATTERN APPEARS TO BE LOOKING A LITTLE WARMER
IN THE COMING DAYS. STILL NO PRECIPITATION EXPECTED AS A DRY
NORTHWEST FLOW ALOFT CONTINUES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 514 AM CST SAT NOV 23 2013
THE MVFR/LOCAL IFR CIGS ACROSS NCNTL NEB IS EXPECTED TO DRIFT WEST
A BIT THIS MORNING AND THE LIFT NORTH AND OUT OF THE FCST AREA BY
AROUND 03Z THIS EVENING. THE MODELS ARE QUITE DIFFERENT WITH THE EXPANSE
AND DURATION OF THIS FEATURE BUT THE RAP APPEARS TO BE VERIFYING
THE BEST AND IS THE BASIS FOR THE FORECAST.
THE STRATUS COULD ACTUALLY MOVE WEST OF KVTN THIS MORNING WITH VFR
DEVELOPING. SO THE RAP IS THE BEST MODEL BUT THE EXPANSE AND
LOCATION OF THE STRATUS REMAINS UNCERTAIN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1006 AM EST SAT NOV 23 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL CROSS THE REGION EARLY THIS AFTERNOON WITH
A FEW SNOW SHOWERS OR BRIEF SQUALLS. THIS FRONT WILL USHER IN THE
COLDEST AIR OF THE SEASON SO FAR WITH AREAS OF LAKE EFFECT SNOW
SOUTHEAST OF THE LAKES TONIGHT AND SUNDAY. TEMPERATURES WILL
MODERATE SOME EARLY NEXT WEEK BUT REMAIN BELOW AVERAGE. A FRESH
BATCH OF VERY COLD AIR IS EXPECTED BY THANKSGIVING WITH FREQUENT
CHANCES OF SOME LIGHT SNOW THROUGH THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
OUR WEATHER WILL BECOME CONSIDERABLY MORE WINTRY IN THE NEXT
COUPLE HOURS AS A STRONG ARCTIC FRONT MOVES ACROSS OUR REGION
DURING THE AFTERNOON HOURS. AHEAD OF THIS...SOME LAKE EFFECT SNOWS
HAVE DEVELOPED EAST OF LAKE ONTARIO. BECAUSE THESE MAY PRODUCE
SOME PRE-FRONTAL SNOW ACCUMULATIONS HAVE MOVED UP THE TIMING OF
THE ADVISORY EAST OF LAKE ONTARIO BY A COUPLE HOURS...HOWEVER
THESE ACCUMULATIONS WILL BE NORTH OF THE STEADIEST POST-FRONTAL
SNOWS SO THE STORM TOTALS REMAIN THE SAME. ELSEWHERE IS A MIX OF
SUN AND CLOUDS...WHICH WILL QUICKLY FILL IN WITH THE PASSAGE OF
THE FRONT. SPEAKING OF THE COLD FRONT...AT 1000 AM THE BOUNDARY
HAD JUST REACHED TORONTO. FOLLOWING THE HRRR TIMING...EXPECT THE
FRONT TO REACH BUFFALO AROUND NOON...AS IT QUICKLY DROPS TO THE
SOUTHWEST. THIS WILL BRING A ROUND OF SNOW SHOWERS WITH THE
FRONT...BEFORE THE EVENT EVOLVES INTO A LAKE EFFECT ONE. MOST
LOCATIONS ARE AT OR NEAR DAYTIME HIGHS LATE THIS MORNING..WITH
TEMPERATURES FALLING INTO THE 20S BEHIND THE ARCTIC FRONT THIS
AFTERNOON.
BY NOONTIME OR SHORTLY AFTER THE STRONG ARCTIC FRONT WILL CROSS THE
REGION FROM NORTHWEST TO SOUTHEAST ALONG WITH A SHARP MID LEVEL
TROUGH AND VORTICITY MAXIMA. THIS WILL PRODUCE A BRIEF BAND OF SNOW
SHOWERS IN MOST AREAS. THE ARCTIC FRONT WILL BRIEFLY BECOME LAKE
ENHANCED AS WELL EAST OF BOTH LAKES WITH A BRIEF BURST OF HEAVIER
SNOW OFF LAKE ERIE FROM THE BUFFALO SOUTHTOWNS INTO THE SOUTHERN
TIER. THIS MAY PRODUCE A QUICK INCH OR SO OF ACCUMULATION. A SIMILAR
EFFECT WILL TAKE PLACE EAST OF LAKE ONTARIO AN HOUR OR TWO LATER.
OUTSIDE OF LAKE EFFECT AREAS ANY ACCUMULATION WILL BE VERY LIGHT...
A DUSTING TO HALF INCH.
THE MAIN CONCERN CONTINUES TO REVOLVE AROUND LAKE EFFECT POTENTIAL
BEHIND THE ARCTIC FRONT. 850MB TEMPS DROP TO AROUND -18C TONIGHT
WHICH WILL SUPPORT EXTREME INSTABILITY WITH LAKE INDUCED EQUILIBRIUM
LEVELS RISING TO 17K FEET OR BETTER. THE MAIN MITIGATING FACTORS TO
A LARGER EVENT WILL BE A SHORT NORTHWEST FETCH AND RELATIVELY
SHALLOW AND SPARSE SYNOPTIC SCALE MOISTURE.
OFF LAKE ONTARIO...
THERE WILL BE A LITTLE LONGER PERIOD OF WESTERLY FLOW ALONG AND JUST
BEHIND THE ARCTIC FRONT THIS AFTERNOON AS BOTH THE NAM AND GFS HAVE
A WEAK FRONTAL WAVE CROSSING THROUGH THE SAINT LAWRENCE VALLEY NEAR
THE CORE OF STRONGEST DPVA AHEAD OF THE MID LEVEL TROUGH. THIS WAVE
SHOULD BRING A BRIEF PERIOD OF DEEPER MOISTURE...AND THAT COMBINED
WITH UPSLOPE ENHANCEMENT ON THE TUG HILL SHOULD PRODUCE A BRIEF
WINDOW OF HEAVIER SNOW. MAY SEE A QUICK 3-6 INCHES ON THE TUG HILL
DURING THE AFTERNOON AND EARLY EVENING...WITH 2-3 INCH AMOUNTS FOR
THE REST OF LEWIS COUNTY AND SOUTHERN/EASTERN JEFFERSON COUNTY.
BY MID EVENING FLOW WILL QUICKLY TURN NORTHWEST TO 310-320 DEGREES.
THIS WILL CARRY LAKE EFFECT SOUTH AND BREAK IT APART INTO MULTIPLE
BANDS...WITH THE FLOW VEERING FURTHER TO AROUND 330 DEGREES LATE
TONIGHT AND SUNDAY MORNING. NORTHWEST FLOW EVENTS ARE VERY SUBTLE
AND DIFFICULT TO PINPOINT WHERE GREATER ACCUMS WILL OCCUR. THE
HEAVIEST BAND MAY END UP BEING OVER CENTRAL AND SOUTHEAST OSWEGO
COUNTY WITH A SLIGHTLY LONGER FETCH AND ENHANCED CONVERGENCE
ORIGINATING FROM A CONCAVE SHAPED BAY ON THE NORTHERN SHORE NEAR
KINGSTON ONTARIO. ANOTHER MORE DOMINANT BAND ALSO TYPICALLY FORMS
FROM THE EASTERN SUBURBS OF ROCHESTER EAST ACROSS WAYNE COUNTY AND
NORTHEAST ONTARIO COUNTY...POSSIBLY CLIPPING CAYUGA COUNTY NEAR THE
THRUWAY.
FARTHER WEST...MESOSCALE MODELS AND OVERALL PATTERN CONTINUE TO
POINT TO THE POTENTIAL FOR A GEORGIAN BAY CONNECTION SOMEWHERE
BETWEEN ROCHESTER AND BUFFALO STARTING THIS EVENING. THESE ARE THE
MOST DIFFICULT OF ALL TO TIME AND PLACE...BUT CAN BRING VERY NARROW
CORRIDORS OF ENHANCED ACCUMULATION. WITH THIS IN MIND...HAVE OFFERED
SOME HIGHER ACCUMULATIONS IN THE FORECAST FOR EASTERN NIAGARA...
ORLEANS...AND GENESEE COUNTIES TONIGHT. THE FORECAST ACCUMULATIONS
ARE LIKELY TOO BROAD BRUSHED...BUT EXACT BAND PLACEMENT IS TOO
UNCERTAIN FOR ANY MORE DETAIL AT THIS TIME.
OFF LAKE ERIE...
FOLLOWING THE BRIEF BURST OF LAKE ENHANCEMENT EARLY THIS AFTERNOON
EXPECT MULTIPLE BANDS TO DEVELOP ON NORTHWEST FLOW...WITH UPSLOPE
ENHANCEMENT ACROSS THE HIGHER TERRAIN. THE SHORT FETCH WILL KEEP
THIS ACTIVITY RELATIVELY LIGHT MOST OF THE TIME ACROSS THE HIGHER
TERRAIN...ALTHOUGH PERSISTENCE MAY LEAD TO SOME DECENT SNOW TOTALS
THROUGH TONIGHT AND INTO SUNDAY ON THE CHAUTAUQUA RIDGE AND POSSIBLY
THE HILLS OF SOUTHERN ERIE/WYOMING COUNTIES. ACROSS SOUTHWEST
CHAUTAUQUA COUNTY AN UPSTREAM CONNECTION TO LAKE HURON IS STILL A
POSSIBILITY. MESOSCALE MODELS CONTINUE TO SHOW THE STRONGEST AND
MOST PERSISTENT LAKE HURON BAND TO BE OVER NORTHWEST PA...BUT IT MAY
OCCASIONALLY MIGRATE INTO SOUTHWEST CHAUTAUQUA COUNTY ESPECIALLY
THIS EVENING AND AGAIN ON SUNDAY. IF THIS OCCURS THERE WOULD BE
ENHANCED SNOW TOTALS IN PLACES SUCH AS SHERMAN AND CLYMER. AMOUNTS
WILL BE DRAMATICALLY LESS ALONG THE LAKESHORE WITHOUT THE BENEFIT OF
UPSLOPE FLOW.
AS FAR AS HEADLINES GO...DECIDED TO SIMPLIFY AND CHANGE ALL
HEADLINES TO THE LAKE EFFECT VARIETY. UNFORTUNATELY IN NORTHWEST
FLOW LAKE EFFECT SNOW ADVISORIES NEED TO BE BROAD BRUSHED FOR MANY
AREAS SOUTHEAST OF THE LAKES...BUT ACTUAL ADVISORY AMOUNTS WILL ONLY
BE REALIZED IN VERY NARROW BANDS WITH MANY AREAS COMING IN WITH
SUB-ADVISORY ACCUMULATIONS. THE LAKE EFFECT SNOW WARNING WILL REMAIN
FOR CHAUTAUQUA COUNTY...WITH THE BEST CHANCE OF WARNING CRITERIA
ONLY IN THE SOUTHWEST CORNER OF THE COUNTY. WILL KEEP OSWEGO COUNTY
AN ADVISORY FOR NOW...BUT IT IS POSSIBLE THIS COULD NEED UPGRADING
TO A WARNING IF A PERSISTENT BAND DEVELOPS OVER THE CENTRAL AND
SOUTHEAST PORTION OF THE COUNTY. NORTHWEST FLOW IS UNFAVORABLE FOR
THE CORRIDOR FROM NIAGARA FALLS TO THE BUFFALO METRO AREA...AND ALSO
ALLEGANY COUNTY SO THESE AREAS WERE REMOVED FROM HEADLINES.
IT WILL ALSO BECOME WINDY BEHIND THE ARCTIC FRONT WITH GUSTS IN THE
40-45 MPH RANGE...ESPECIALLY SOUTHEAST OF LAKE ONTARIO. THIS WILL
PRODUCE BLOWING AND DRIFTING SNOW IN AREAS WHICH RECEIVE MORE THAN
AN INCH OR TWO OF ACCUMULATION. TEMPERATURES WILL DROP INTO THE
TEENS TONIGHT IN ALL AREAS EXCEPT THE IMMEDIATE LAKESHORES. WIND
CHILLS WILL DROP TO NEAR ZERO AT TIMES LATE TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
A NORTHWEST FLOW OF VERY COLD AIR WILL IMPACT THE AREA ON SUNDAY.
AFTERNOON TEMPERATURES WILL STRUGGLE TO GET ABOVE THE LOWER
20S...AND SOME LOCATIONS ACROSS THE HIGHER ELEVATIONS EAST OF BOTH
LAKES WILL LIKELY SEE READINGS IN THE UPPER TEENS.
THESE VERY COLD TEMPERATURES WILL RESULT IN EXTREME INSTABILITY OVER
THE LAKES...WITH LAKE EQUILIBRIUM LEVELS EXPECTED TO RANGE FROM
15K-18K FEET...ESPECIALLY DURING THE FIRST HALF OF THE DAY. THE
LATEST BUFKIT PROFILES STILL SHOW PLENTY OF MOISTURE INTERSECTING
THE FAVORABLE SNOW GROWTH REGION AS WELL. AS A RESULT...ONGOING LAKE
SNOW BANDS WILL REMAIN INTACT THROUGHOUT THE DAY. THE ONE FACTOR
THAT WILL LIMIT SNOW ACCUMULATIONS WILL BE THE RELATIVELY SHORT
FETCH ACROSS THE LAKES. HOWEVER...THE MESOSCALE MODELS STILL
SUGGESTS THAT UPSTREAM CONNECTIONS TO LAKE HURON AND GEORGIAN BAY
WILL COME INTO PLAY AND HELP TO ENHANCE THE SNOWFALL AT TIMES. THIS
WILL BE ESPECIALLY TRUE ALONG THE CHAUTAUQUA RIDGE.
FOR LAKE ONTARIO...THE CONNECTION TO GEORGIAN BAY MAY HAVE THE
BIGGEST IMPACT ALONG THE WESTERN SHORES OF THE LAKE DURING THE
MORNING...INCLUDING AREAS NORTHEAST OF BUFFALO. AS THE BOUNDARY
LAYER WINDS BACK A LITTLE MORE DURING THE AFTERNOON...THE STEADIER
LAKE SNOWS MAY SHIFT TO THE EAST AND IMPACT AREAS SOUTHEAST OF THE
LAKE MORE.
THE COMBINATION OF SNOW AND NORTHWEST WINDS GUSTING UP TO ABOUT 30
MPH WILL CONTINUE TO HAVE A SIGNIFICANT IMPACT ON TRAVEL ACROSS THE
AREA ON SUNDAY. AS A RESULT...LAKE EFFECT SNOW WARNINGS/ADVISORIES
ARE IN PLACE AS OUTLINED BELOW.
SUNDAY NIGHT...HIGH PRESSURE AT THE SURFACE WILL SHIFT EAST INTO THE
MIDDLE ATLANTIC STATES. THIS WILL CAUSE THE BOUNDARY LAYER WINDS TO
BACK TO THE SOUTHWEST...WHILE THE LOW LEVEL SHEAR INCREASES. AT THE
SAME TIME...LAKE EQUILIBRIUM LEVELS WILL BE LOWERING AS TEMPERATURES
ALOFT GET WARMER. ALL OF THESE FACTORS WILL CAUSE THE ONGOING LAKE
SNOW BANDS TO LIFT SLOWLY TO THE NORTH AND WEAKEN AS THE NIGHT WEARS
ON. HOWEVER...THERE STILL WILL BE PLENTY OF LOW LEVEL MOISTURE
WITHIN THE SNOW GROWTH AREA TO GENERATE A COUPLE MORE INCHES OF SNOW
SOUTHEAST OF THE LAKES.
ON MONDAY...THE FOCUS WILL SHIFT MORE TO THE SYNOPTIC SCALE. THE
SURFACE RIDGE WILL SLIDE OFF THE EAST COAST...WHILE A CLIPPER DIVES
SOUTHEAST ACROSS ONTARIO PROVINCE. WARM AIR ADVECTION AND A DEEPER
LAYER OF MOISTURE AHEAD OF THE CLIPPER WILL GENERATE A MORE
WIDESPREAD AREA OF LIGHT SNOW...ESPECIALLY DURING THE AFTERNOON.
THE PRESSURE GRADIENT BETWEEN THE HIGH AND APPROACHING LOW WILL
LIKELY RESULT IN RATHER WINDY CONDITIONS...ESPECIALLY NORTHEAST OF
LAKE ERIE. TEMPERATURES ON MONDAY WILL MODERATE INTO THE LOWER TO MID
30S ACROSS THE LOWER ELEVATIONS...BUT THE BRISK WINDS WILL KEEP WIND
CHILLS IN THE 20S.
LIGHT SNOW WILL CONTINUE TO IMPACT OUR AREA MONDAY NIGHT AS THE LOW
TRACKS SOUTH OF JAMES BAY INTO SOUTHERN QUEBEC.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ON TUESDAY LOW PRESSURE WILL MOVE ACROSS ONTARIO AND QUEBEC. THIS
MAY BRING A FEW MORE LIGHT SNOW SHOWERS TO THE REGION AND THE
AIRMASS REMAINS JUST COLD ENOUGH FOR SOME LAKE ENHANCEMENT EAST AND
NORTHEAST OF BOTH LAKES.
NEXT WEDNESDAY STILL BEARS WATCHING FOR A POTENTIAL EAST COAST
STORM. THE MID LEVEL CLOSED LOW CURRENTLY STUCK OVER THE SOUTHWEST
STATES WILL EJECT EASTWARD AND REACH THE MID ATLANTIC COAST BY LATE
WEDNESDAY. AT THE SAME TIME ANOTHER SHARP NORTHERN STREAM TROUGH
WILL DIG THROUGH THE GREAT LAKES. MODEL GUIDANCE VARIES ON THE
INTERACTION AND POTENTIAL PHASING OF THESE TWO SYSTEMS.
12Z GFS IS INDICATING A SHORT SHOT OF LAKE EFFECT SNOW IN
SOUTHWESTERLY FLOW WHICH MAY IMPACT THE METRO AREAS OF
BUFFALO...ROCHESTER...AND WATERTOWN WEDNESDAY AND WEDNESDAY
NIGHT...FOLLOWED BY COLDER NORTHWEST TO NORTH WINDS ACROSS THE LAKES
AS THE COASTAL LOW DEVELOPS AND ANOTHER ROUND OF LAKE SNOW SOUTH AND
SOUTHEAST OF THE LAKES.
12Z ECMWF DEVELOPS THE COASTAL LOW CLOSER TO THE EAST COAST AND
INDICATES A SNOW EVENT FOR THE COASTAL REGION AND INLAND TO EASTERN
NEW YORK STATE DURING TUESDAY NIGHT THROUGH WEDNESDAY AFTERNOON...
THEN A WEAK LAKE RESPONSE FOLLOWED BY COLD HIGH PRESSURE ON THURSDAY.
IN EITHER CASE...AFTER AN UNSETTLED MID WEEK PERIOD...THERE WILL BE
AN INFLUX OF COLDER AIR FOR THANKSGIVING DAY AND A BIT OF A WARMING
TREND FOR THE END OF THE WEEK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
THROUGH NOON MOST AREAS WILL BE VFR AHEAD OF THE FRONT...WITH
PATCHY MVFR CIGS EAST OF THE LAKES.
AN ARCTIC FRONT WILL CROSS THE AREA EARLY THIS AFTERNOON WITH A
BRIEF PERIOD OF SNOW SHOWERS AND SOME LAKE ENHANCEMENT EAST OF THE
LAKES WITH BRIEF IFR. LATER THIS AFTERNOON AND TONIGHT LAKE EFFECT
SNOW SHOWERS WILL DEVELOP SOUTHEAST OF THE LAKES WITH LOCAL IFR AT
TIMES. THE TAF SITES MOST LIKELY IMPACTED BY MORE PERSISTENT SNOW
SHOWERS WILL BE KJHW AND KROC...WITH LESSER COVERAGE NEAR KBUF AND
KIAG. OVER AT KART...LAKE ENHANCED SNOW DURING THE AFTERNOON AND
EVENING WILL PRODUCE OCCASIONAL IFR...THEN EXPECT AN IMPROVEMENT TO
VFR TONIGHT AS LAKE EFFECT PUSHES WELL SOUTH OF THE AREA.
OUTLOOK...
SUNDAY...AREAS OF IFR SOUTHEAST OF THE LAKES IN LAKE EFFECT SNOW.
MONDAY THROUGH WEDNESDAY...VFR WITH A CHANCE OF SNOW SHOWERS AND
ASSOCIATED BRIEF MVFR/IFR.
&&
.MARINE...
WINDS WILL INCREASE TODAY ALONG AND BEHIND A STRONG ARCTIC COLD
FRONT. THIS WILL BRING MARGINAL GALE FORCE WINDS TO THE EAST HALF OF
LAKE ONTARIO THIS AFTERNOON AND EVENING. ELSEWHERE WINDS WILL
INCREASE TO 30 KNOTS. TONIGHT WINDS WILL BECOME NORTHWEST AND
DIMINISH A LITTLE TO AROUND 25 KNOTS. MODERATE TO STRONG
NORTHWESTERLIES WILL CONTINUE THROUGH SUNDAY.
WITH COLD AIR ENTRENCHED ACROSS THE GREAT LAKES IT WILL BE WINDY
THROUGH MUCH OF NEXT WEEK WITH SMALL CRAFT ADVISORIES ALL THE TIME
AND A FEW BRIEF OPPORTUNITIES AT GALE FORCE WINDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST SUNDAY FOR NYZ001>003-
011>014-020-085.
LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ007-008.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST SUNDAY FOR NYZ004>006.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST SUNDAY FOR NYZ019.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LOZ030.
SMALL CRAFT ADVISORY UNTIL 1 AM EST MONDAY FOR LOZ042.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR LOZ043>045.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LOZ043>045-
063>065.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM
EST SUNDAY FOR SLZ022-024.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...TJP
LONG TERM...TJP
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
948 AM EST SAT NOV 23 2013
.SYNOPSIS... A COLD FRONT WILL CONTINUE TO DROP SOUTH ACROSS THE
CAROLINAS TODAY WITH A REINFORCING COLD FRONT TO FOLLOW TONIGHT AS
COLD HIGH PRESSURE BUILDS IN FOR THE REMAINDER OF THE WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 940 AM SATURDAY...
OVERVIEW: POTENT SHORTWAVE ENERGY OVER THE UPPER MIDWEST AT 08Z THIS
MORNING WILL DIG SOUTHEAST THROUGH THE OH VALLEY THIS AFTERNOON...
AMPLIFYING AN UPPER LEVEL TROUGH AS IT PROGRESSES TOWARD THE MID-
ATLANTIC COAST TONIGHT. IN THE LOWER LEVELS...A COLD FRONT EXTENDING
FROM CENTRAL GA NORTHEAST THROUGH CENTRAL NC AND SOUTHEAST VA AT 08Z
WILL PROGRESS SOUTHEAST TO THE COAST THIS MORNING...FOLLOWED BY A
STRONGER REINFORCING COLD FRONT THIS EVENING...THE LEADING EDGE OF
AN ARCTIC AIRMASS (1045-1050 MB SFC HIGH IN THE CENTRAL CONUS)
BUILDING INTO THE REGION OVERNIGHT. -VINCENT
AS OF 12Z THIS MORNING THE COLD FRONT WAS DRAPED ACROSS CENTRAL
NORTH CAROLINA WHERE IT WAS BEGINNING TO STALL OUT. VISIBLE
SATELLITE IMAGERY HAD SHOWN A DISTINCT BOUNDARY WITH THE TRIAD
CLEARING OUT FOR A TIME EARLIER THIS MORNING BUT SINCE THEN CLOUDS
HAVE BEGUN TO BACK BUILD OVER THE TRIANGLE AREA AND NEW CLOUD COVER
HAS ADVECTED INTO THE TRIAD FROM THE WEST. AS A RESULT...EXPECT HIGH
TEMPERATURES TODAY TO BE ABOUT WHAT THEY ARE NOW WITH MAYBE SOME
SLIGHT INCREASES TO THE CURRENT OBSERVED TEMPERATURES. AS FAR AS
PRECIPITATION GOES...IT SHOULD REMAIN LIGHT IN THE FRONTAL ZONE AND
POINTS SOUTH AND EAST WITH TOTALS A COUPLE HUNDREDTHS OF AN INCH OR
LESS. LATER THIS MORNING AND INTO THE AFTERNOON COLD AIR ADVECTION
SHOULD TAKE OVER DROPPING TEMPERATURES IN THE NORTHERN HALF OF THE
CWA WITH CLOUD COVER TO THE SOUTH KEEPING TEMPERATURES DOWN THERE AS
WELL. WITH THE ONSET OF COLD AIR ADVECTION WE SHOULD SEE A DECREASE
IN DEWPOINTS AS WELL AS AN INCREASE IN THE WIND GUSTS...UP TO 15
KNOTS OR SO AND THIS HAS ALREADY BEGUN TO OCCUR IN THE TRIAD.
FOR THIS AFTERNOON BOTH THE RAP AND THE NAM ARE DEPICTING A FAIRLY
WELL DEFINED 500 MB VORT MAX THAT WILL RUN ALONG THE FRONT AND
PROVIDE SOME EXTRA FORCING FOR SOME SPRINKLES TO LIGHT RAIN ACROSS
THE SOUTHERN HALF OF THE CWA. HAVE INCREASED POPS TO CHANCE IN THE
SOUTH AROUND 18Z AND THEN QUICKLY TAPERING OFF AFTER DARK.
THE SURFACE HIGH WILL CONTINUE TO BUILD IN FROM THE NORTHWEST
TONIGHT AND A REINFORCING DRY COLD FRONT WILL HELP SKIES CLEAR FORM
NORTH TO SOUTH. COMBINED COLD AIR ADVECTION AND CLEARING WILL HELP
TEMPERATURES DROP INTO THE MIDDLE 20S FOR LOWS IN THE TRIAD WITH
UPPER 20S TO LOW 30S ELSEWHERE.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 325 AM SATURDAY...
STRONG ARCTIC HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION
ON SUNDAY...BECOMING CENTERED OVER THE AREA SUNDAY NIGHT. WITH COLD
ADVECTION PERSISTING THROUGH MUCH OF THE DAY...1000-850 MB
THICKNESSES BETWEEN 1265-1275 METERS IN THE AFTERNOON...AND H85
TEMPS RANGING FROM -10C (S) TO -13C (N)...EXPECT TEMPERATURES TO
STRUGGLE OUT OF THE 30S IN MOST LOCATIONS...AND WILL INDICATE HIGHS
RANGING FROM JUST ABOVE FREEZING (~34F) IN THE NW TO NEAR 40F IN THE
FAR S/SE. WITH A COLD/DRY ARCTIC AIRMASS SETTLING OVERHEAD SUN
NIGHT...EXPECT OPTIMAL RADIATIONAL COOLING AND LOWS IN THE TEENS TO
LOWER 20S...COLDEST IN RURAL AND LOW-LYING AREAS. -VINCENT
&&
.LONG TERM /MONDAY THOUGH FRIDAY/...
AS OF 222 AM SATURDAY...
...A GOOD SOAKING RAIN TUE-WED...
...PRECIPITATION MAY BEGIN AS A BRIEF WINTRY MIX IN THE NW PIEDMONT
IF THE PRECIPITATION BEGINS BEFORE 12Z TUESDAY...
THE CORE OF THE ARCTIC AIR MASS WILL BE LOCATED OVER THE REGION AT
12Z MONDAY. HIGH PRESSURE WILL GRADUALLY SHIFT OFFSHORE MONDAY
NIGHT. MODELS ARE IN EXCELLENT AGREEMENT WITH THE PARENT HIGH
PRESSURE MOVING OFFSHORE MONDAY NIGHT (VERY CRITICAL TO THIS
FORECAST). THIS TO BE FOLLOWED BY A RAPID INCREASE IN MID AND UPPER
LEVEL MOISTURE MONDAY NIGHT. THEREFORE... A CONTINUED MOSTLY SUNNY
DAY IS FORECAST MONDAY WITH HIGHS 40-45. INCREASING CLOUDINESS
MONDAY NIGHT WITH LOWS 30-35.
A SIGNIFICANT MID/UPPER LEVEL LOW PRESSURE IS FORECAST TO EJECT OUT
OF TEXAS TUESDAY MORNING... THEN TRACK EAST ALONG THE GULF COAST AND
ACROSS THE SOUTHEASTERN STATES TUESDAY THROUGH WEDNESDAY. RECENT
DETERMINISTIC MODELS HAVE BEEN FORECASTING A COUPLE OF STRUNG OUT
WEAK LOW PRESSURE CENTERS TO TRACK FROM THE N-NE GULF OF MEXICO
ALONG THE CAROLINA COAST TUE-WED. THIS IS IMPORTANT IN THAT THERE
APPEARS TO BE LITTLE PHASING OF THE POLAR JET WITH THIS SOUTHERN
BRANCH SYSTEM UNTIL THE SYSTEM IS PAST OUR LATITUDE AND OFFSHORE
LATE WED... KEEPING THE SURFACE SYSTEM(S) WEAK AND STRUNG OUT
INSTEAD OF ONE STRONG LOW PRESSURE. REGARDLESS... THIS STILL APPEARS
TO BE A GOOD RAINFALL PRODUCER FOR OUR REGION. MANY AREAS HAVE HAD
LESS THAN 25 PERCENT OF THE AVERAGE RAINFALL SINCE SEPTEMBER.
AS FOR PRECIPITATION TYPE (P-TYPE)... CONFIDENCE CONTINUES HIGH IN
THAT RAIN WILL BE PREDOMINATE P-TYPE DUE TO THE RAPIDLY DEVELOPING
PROMINENT WARM NOSE ALOFT. HOWEVER IN THE WESTERN AND NORTHERN
PIEDMONT ZONES SOME LIGHT SNOW/SLEET/FREEZING RAIN MAY FALL AT THE
ONSET DEPENDING ON TIMING. IF THE PRECIPITATION DEVELOPS EARLY
ENOUGH (BEFORE 15Z)... THERE MAY BE SOME NUISANCE LIGHT SNOW/SLEET
(12Z) BEFORE A QUICK CHANGE TO LIGHT FREEZING RAIN/RAIN THEN ALL
RAIN BY 15Z. THE MAJORITY OF ENSEMBLE FORECASTS INDICATE STRONG WAA
JUST ABOVE THE BOUNDARY LAYER TAKING THE 1000/850 AND 850/700
PARTIAL THICKNESSES WELL INTO THE HISTORICALLY "ALL RAIN" CATEGORY
RATHER QUICKLY TUESDAY.
THE AMOUNT OF VERY DRY AIR IN PLACE BEFORE MOISTENING TUESDAY
MORNING APPEARS SUBSTANTIAL... WITH DEW POINTS FORECAST IN THE 15-20
RANGE AROUND 12Z IN THE PIEDMONT. PARTIALS IN THE 1295-1305 / 1550
RANGE RAPIDLY WARM WITH TIME...SUGGESTING A POSSIBLE LIGHT
FROZEN/FREEZING EVENT IN THE NW (TRACE AMOUNTS) QUICKLY CHANGING TO
RAIN. THE SURFACE WET BULB FORECASTS QUICKLY MODIFY AFTER
DAYBREAK... REACHING THE LOWER 30S BY MIDDAY AND MID 30S BY EVENING.
GIVEN THAT THERE WILL BE PLENTY OF EVAPORATION AT THE LEADING EDGE
OF THE PRECIPITATION SHIELD... SUGGESTING THAT ANYTHING THAT REACHES
THE SURFACE WILL BE VERY LIGHT THROUGH THE CRITICAL PERIOD (10Z-
13Z). THEREFORE... WE WILL MAINTAIN THE "ALL RAIN" FORECAST FOR NOW
GIVEN THE UNCERTAINTY OF TIMING OF ARRIVAL OF THE PRECIPITATION
NOTING THAT ANYTHING OTHER THAN RAIN WOULD MOST LIKELY BE OF
NUISANCE.
THE LATEST OPERATIONAL EUROPEAN CONTINUES TO BE QUICK AND ROBUST
WITH DEVELOPING/SPREADING PRECIPITATION NE ACROSS WESTERN NC BETWEEN
06Z AND 12Z TUESDAY. EVEN THE LATEST NAM A FEW ENSEMBLE MEMBERS ARE
THIS AGGRESSIVE... WITH AS MUCH AS 0.25 OF QPF BY 12Z IN THE HKY TO
INT AREAS. IF THIS WERE TO OCCUR... THE SOUNDINGS INDICATE RAPIDLY
WARMING MID LEVELS BETWEEN 06Z/12Z TUESDAY... BECOMING A PROMINENT
WARM NOSE ALOFT AS EARLY AS 18Z. THE NEAR SURFACE LAYER MAY BE VERY
CLOSE TO OR SLIGHTLY BELOW FREEZING FOR A COUPLE OF HOURS CENTERED
AROUND 12Z. THEREFORE... THE CURRENT WORST CASE SCENARIO WOULD BE
FOR SOME LIGHT SNOW AND SLEET TO DEVELOP BEFORE SUNRISE... QUICKLY
BECOMING LIGHT FREEZING RAIN AROUND 12Z... THEN RAIN BY 15Z AS
WARMING ALOFT AND HEAVIER RAIN WARMS THE COLUMN FROM THE TOP DOWN.
THIS WOULD BE THE ONE CAVEAT... IF THE LATEST EC AND SOME ENSEMBLE
MEMBERS PROVE CORRECT IN THE QUICKER ARRIVAL OF LIGHT PRECIPITATION
BEFORE OR AROUND DAYBREAK... THEN MORE IN THE WAY OF SOME LIGHT
FREEZING RAIN OR EVEN SOME BRIEF LIGHT FROZEN HYDROMETERS MAY FALL
IN THE NW.
SENSIBLE WEATHER THEN... PREDOMINATELY COLD RAIN IS EXPECTED TUESDAY
INTO TUESDAY NIGHT... WITH PERIODS OF RAIN EVEN INTO WEDNESDAY AS
THE MID/UPPER LOW FOLLOW... AND TRACK ACROSS THE REGION WEDNESDAY.
PARTIAL THICKNESSES SUPPORT A BRIEF MIX OR CHANGE TO LIGHT SNOW
(LITTLE ACCUMULATION EXPECTED CURRENTLY) BEFORE ENDING IN THE NW AND
N PIEDMONT BETWEEN 18Z AND 23Z WED.
IF THE 1-2 INCH QPF OF RAINFALL WORKS OUT BEFORE HAND... AND WITH
TEMPS WELL ABOVE 35 WED AFTERNOON... IT WOULD HAVE TO SNOW HEAVILY
TO ACCUMULATE. THIS IS NOT ANTICIPATED AT THIS TIME.
CLEARING IS EXPECTED WEDNESDAY NIGHT AND DRY COLD CONDITIONS CAN BE
EXPECTED THANKSGIVING DAY AND FRIDAY. LOWS IN THE LOWER TO MID 20S.
HIGHS IN THE LOWER TO MID 40S (15-20 DEGREES BELOW NORMAL).
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 645 AM SATURDAY...
24-HR TAF PERIOD: WINDS WILL SHIFT TO THE NW/NNW AT 8-12 KT WITH
SPORADIC GUSTS UP TO 15-20 KT POSSIBLE FOR SEVERAL HOURS AFTER A
COLD FROPA THIS MORNING...WITH WINDS EVENTUALLY DECREASING TO 5-10
KT LATER THIS AFTERNOON. A SECONDARY AND STRONGER ARCTIC COLD
FRONTAL PASSAGE WILL OCCUR THIS EVE/TONIGHT. DUE TO STRONG PRESSURE
RISES BEHIND THE ARCTIC FRONT...EXPECT NW/NNW WINDS TO RAPIDLY
INCREASE AND BECOME SUSTAINED AT 13-17 KT WITH GUSTS UP TO 25 KT
LATE TONIGHT THROUGH SUNDAY MORNING. AT THIS TIME...EXPECT VFR
CONDITIONS TO PREVAIL ASIDE FROM ISOLD AREAS OF FOG AND MVFR STRATUS
FOR A FEW HOURS THIS MORNING...PERHAPS AFFECTING THE FAY TERMINAL
THROUGH 12-14Z.
LOOKING AHEAD: VFR CONDITIONS ASSOCIATED WITH ARCTIC HIGH PRESSURE
WILL PREVAIL TONIGHT THROUGH MONDAY. A SIGNIFICANT STORM SYSTEM WILL
DEVELOP ALONG THE GULF COAST MON/MON NIGHT...THEN TRACK NORTHEAST
ALONG THE CAROLINA COAST ON TUE/WED. EXPECT WIDESPREAD ADVERSE
AVIATION CONDITIONS MON NIGHT THROUGH WED. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT/ELLIS
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
633 AM EST SAT NOV 23 2013
.SYNOPSIS...
A STRONG ARCTIC COLD FRONT WILL CROSS THE AREA LATER THIS MORNING
FOLLOWED BY THE COLDEST TEMPERATURES OF THE SEASON. LOW PRESSURE
WILL EMERGE FROM THE NORTHERN GULF OF MEXICO BRINGING A SIGNIFICANT
RAIN EVENT FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...AN ARCTIC COLD FRONT CURRENTLY EXTENDING FROM
CENTRAL NORTH CAROLINA INTO THE UPSTATE OF SOUTH CAROLINA IS
EXPECTED TO MOVE SOUTHEAST...CROSSING THROUGH THE EASTERN CAROLINAS
LATE THIS MORNING. THERE ARE STILL SOME TIMING DIFFERENCES WITH THIS
FRONT: THE 06Z NAM AND 06Z GFS ARE TOO FAST BUT THE 10Z RUC HAS A
GOOD HANDLE ON ITS CURRENT AND FORECAST POSITIONS OUT THROUGH 18Z.
AS IS TYPICAL WITH A MORNING COLD FRONTAL PASSAGE...MOS HIGHS SHOULD
BE SEVERAL DEGREES TOO COOL AS THEY RESOLVE A TOO-WIDE/BLURRED
FRONTAL ZONE RATHER THAN THE TIGHT TEMPERATURE GRADIENT THAT
ACTUALLY EXISTS. MY FORECAST HIGHS ARE 2-3 DEGREES ABOVE MOS
(63-68...WARMEST NEAR GEORGETOWN) ALTHOUGH THESE READINGS SHOULD
OCCUR ONLY BRIEFLY AT THE TIME OF FRONTAL PASSAGE WITH FALLING
TEMPERATURES EXPECTED THROUGHOUT THE AFTERNOON.
RADAR COMPOSITES REVEAL BAND OF LIGHT SHOWERY RAIN ACROSS THE
EASTERN CAROLINAS EXTENDING BACK TO THE SAVANNAH RIVER SOUTH OF
AUGUSTA. THIS APPEARS TO BE ASSOCIATED WITH WEAK ISENTROPIC LIFT
WITHIN A MID-LAYER CLOUD DECK 7000-12000 FT AGL. MODELS SHOW
ISENTROPIC LIFT HAVING ITS GREATEST MAGNITUDE (AND THAT`S NOT SAYING
MUCH) BETWEEN NOW AND NOON...WITH NEUTRAL TO ISENTROPIC DOWNGLIDE
CONDITIONS DEVELOPING FROM NORTH TO SOUTH. MY QPF NUMBERS ARE LESS
THAN ONE TENTH OF AN INCH EVERYWHERE. CLOUDS WILL PROBABLY NOT BREAK
IN ANY SUBSTANTIAL SENSE DURING THE DAY...AND THE LACK OF INSOLATION
WILL NOT BE ABLE TO OFFSET STRENGTHENING COLD ADVECTION DURING THE
AFTERNOON.
FOR TONIGHT HIGH PRESSURE OVER THE CENTRAL PLAINS WILL SURGE
EASTWARD AS A SHORTWAVE EMBEDDED IN THE NORTHEASTERN U.S. TROUGH
SWINGS THROUGH VIRGINIA. THIS WILL LEAD TO THE REAL ARCTIC SURGE OF
THIS EVENT DEVELOPING AROUND OR JUST BEFORE MIDNIGHT. 850 MB
TEMPERATURES WILL FALL FROM AROUND +6C THIS EVENING TO -3C BY
DAYBREAK SUNDAY...AS WINDS AT THE TOP OF THE WELL-MIXED BOUNDARY
LAYER WINDS INCREASE TO 20-30 KNOTS. THE TEMPERATURE FORECAST
TONIGHT IS ACTUALLY QUITE TRICKY AS STRONG WINDS AND GOOD MIXING CAN
SOMETIMES CREATE A NIGHTTIME DEEP DRY-ADIABATIC PROFILE TYPICAL OF
DAYTIME CONDITIONS...WITH LOW TEMPERATURES ENDING UP MUCH WARMER
THAN ONE WOULD THINK POSSIBLE GIVEN THE AIRMASS. MY FORECAST LOWS
ARE A BIT ABOVE MOS GUIDANCE AND RANGE FROM NEAR FREEZING FROM
LUMBERTON TO DARLINGTON...TO 35-38 AT THE COAST.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...COLD AND DRY ARCTIC HIGH BUILDS IN SUNDAY WITH
TEMPERATURES FALLING SHORT OF 50 DURING THE DAY. SURFACE RIDGE AXIS
SHIFTS CLOSE TO THE REGION SUN NIGHT...ENDING COLD ADVECTION BUT
PUTTING RADIATIONAL COOLING IN PLAY. DEEP DRY AIR...LIGHT
WINDS...AND UNSEASONABLY COLD AIR IN PLACE WILL RESULT IN LOWS IN
THE LOW TO MID 20S IN MANY LOCATIONS WITH ISOLATED UPPER TEENS
POSSIBLE INLAND.
WHILE SOME AIR MASS MODIFICATION IS EXPECTED ON MON VERY LOW
STARTING TEMPS COMBINED WITH NORTHEAST FLOW WILL AGAIN KEEP HIGHS
WELL BELOW CLIMO. INCREASING HIGH CLOUD MON AFTERNOON WILL LIMIT
INSOLATION...FURTHER HINDERING TEMP RECOVERY. CLOUDS START TO LOWER
MON NIGHT AS WEAK ISENTROPIC LIFT IS ENHANCED BY DEVELOPMENT OF WEAK
COASTAL TROUGH MON NIGHT. GIVEN THE DEPTH OF THE DRY AIR AND THE
PROPENSITY OF GUIDANCE TO UNDERESTIMATE THE DRY AIR AND THUS
INTRODUCE POP A LITTLE TOO EARLY DO NOT PLAN MAJOR CHANGES TO
INHERITED PRECIP CHANCES MON NIGHT. INCREASING CLOUD COVER WILL HELP
KEEPS MON NIGHT LOWS SIGNIFICANTLY WARMER THAN SUN NIGHT AND MORE
IMPORTANTLY ABOVE FREEZING.
AT THIS POINT IT DOES NOT APPEAR THE MONDAY MORNING RECORD LOWS WILL
BE IN PLAY.
RECORD LOWS FOR NOVEMBER 25 AND THE NORMALS:
--------------------------------------------
ILM - 20 - 1970 NORMAL - 43
FLO - 17 - 1950 NORMAL - 41
CRE - 17 - 1950 NORMAL - 44
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...PERIOD BEGINS WITH A SOUTHERN STREAM SYSTEM
ALREADY AFFECTING THE REGION. ISENTROPIC LIFT WILL TAP INTO DEEP
MOISTURE SPREADING OVER THE AREA AHEAD OF THE GULF COAST SYSTEM ON
TUE. THIS WILL LEAD TO RAIN WITH INTENSITY GRADUALLY INCREASING
THROUGHOUT THE DAY. AT THIS POINT THE MEDIUM RANGE SOLUTIONS DIVERGE
SOMEWHAT. DISTANCE WISE THE TRACKS ARE NOT FAR APART...BUT AS IS
USUALLY THE CASE FOR THE COASTAL CAROLINAS A SMALL DIFFERENCE IN THE
TRACK COULD LEAD TO HUGE DIFFERENCES IN THE FORECAST. WHAT IS KNOWN
IS A POTENT STORM IS LIKELY TO IMPACT THE REGION WITH HEAVY RAIN AND
GUSTY WINDS LATE TUE NIGHT AND WED. THE NATURE OF THE
RAIN...STRATIFORM AS OPPOSED TO MORE CONVECTIVE AND HIGH/LOW
TEMPERATURES ARE WHAT REMAIN UNCERTAIN. AN INLAND TRACK WOULD LEAD
TO WARMER TEMPERATURES BUT ALSO OPEN UP THE POSSIBILITY OF SEVERE
WEATHER. THE INHERITED FORECAST LIES IN THE MIDDLE OF THE GUIDANCE
ENVELOPE AND REMAINS IN GOOD AGREEMENT WITH THE GFS ENSEMBLES.
THEREFORE WILL NOT MAKE MANY CHANGES AT THIS TIME.
SURFACE HIGH BUILDS IN BEHIND THE EXITING SYSTEM BUT THE MID LEVEL
PATTERN REMAINS MORE PROGRESSIVE WHICH KEEPS COLDEST AIR NORTH OF
THE AREA. COLD ADVECTION THU INTO FRI WILL HOLD TEMPERATURES BELOW
CLIMO BUT NOT SEVERAL CATEGORIES BELOW.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...IFR/LIFR IS OCCURRING GENERALLY BENEATH AND AHEAD OF AN
E-W AREA OF LIGHT RAIN THIS MORNING. AS A COLD FRONT MOVES SOUTH
THIS MORNING EXPECT LIFR/IFR CONDITIONS TO SHIFT N-S WITH
IMPROVEMENT TEMPORARILY TO VFR IN THE WAKE OF THE FRONT.
MODELS SUGGEST COPIOUS AMOUNTS OF MOISTURE REMAINING BEHIND THE
FRONT WITH AN APPROACHING UPPER IMPULSE. CONFIDENCE IS HIGH MVFR
CIGS WILL REDEVELOP LATER THIS MORNING AT ALL TERMINALS ALTHOUGH
CONFIDENCE IN TIMING IS LOW. EXPECT MVFR CEILINGS TO PERSIST
THROUGH THE AFTERNOON WITH LINGERING -RA. BY LATE AFTERNOON MVFR
SHOULD IMPROVE TO VFR AT KFLO/KMYR...WITH IMPROVEMENT TO VFR IN THE
EARLY EVENING AT THE COASTAL TERMINALS. VFR EXPECTED THROUGH THE
REMAINDER OF THE EVENING AND OVERNIGHT AS NORTH WINDS WINDS INCREASE
AND SIGNIFICANT DRYING OF THE LOW LEVELS OCCUR.
EXTENDED OUTLOOK...VFR WITH BREEZY CONDITIONS EXPECTED ON SUNDAY.
VFR EXPECTED ON MONDAY...WITH LOW PRESSURE BRINGING RAIN
TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...BIG CHANGES ARE COMING OVER THE NEXT 12-24
HOURS AS AN ARCTIC COLD FRONT MOVES ACROSS THE AREA. THE FRONT
ITSELF WILL MOVE ACROSS THE COASTAL WATERS LATE THIS MORNING...
SHIFTING OUR SOUTHWEST WINDS AROUND TO THE NORTH BUT WITHOUT ANY
IMMEDIATE INCREASE IN SPEED. THAT WILL WAIT UNTIL THIS EVENING
WHEN HIGH PRESSURE OVER THE CENTRAL PLAINS SURGES EAST AND BEGINS
TO PUSH VERY CHILLY AIR OFFSHORE. NORTH WINDS SHOULD INCREASE TO
25-30 KNOTS AFTER MIDNIGHT. MODELS SHOW WINDS AT 1000-1500 FT
ABOVE GROUND LEVEL REACHING 35 KNOTS...AND FOR THIS REASON A GALE
WATCH HAS BEEN ISSUED FOR THE POTENTIAL THESE WINDS WILL MIX DOWN
TO THE OCEAN SURFACE IN GUSTS LATE TONIGHT. THE COLD AIR GALE
EVENT WE HAD EARLIER THIS MONTH FEATURED WINDS ABOUT 5 KNOTS
STRONGER AT 1000-1500 FT ALTITUDE THAN WHAT IS EXPECTED
TONIGHT...SO IT IS NOT GUARANTEED WE WILL SEE GALE-FORCE GUSTS
ACTUALLY MEASURED AT THE GROUND/OCEAN SURFACE.
SEAS CURRENTLY ARE 4 FT OUT AT THE FRYING PAN SHOALS BUOY AND 2 FT
AT THE BUOY SOUTH OF THE MOUTH OF THE CAPE FEAR RIVER. SEAS SHOULD
NOT CHANGE APPRECIABLY UNTIL LATE THIS EVENING...BUT WILL REALLY
START TO BUILD AFTER MIDNIGHT IN RESPONSE TO THE INCREASING WIND
SPEEDS. DOMINANT WAVE PERIODS CURRENTLY AROUND 8 SECONDS SHOULD
SHORTLY CONSIDERABLY ONCE THE WINDS START CRANKING AFTER MIDNIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...STRONG NORTHERLY FLOW CONTINUES SUN WITH SOLID
SCA CONDITIONS FOR AT LEAST THE FIRST HALF OF THE DAY. COLD
ADVECTION AND PRESSURE GRADIENT START TO WEAKEN LATER IN THE DAY
WITH WINDS DROPPING UNDER 20 KT IN THE EVENING. WINDS VEER TO
NORTHEAST SUN NIGHT AND MON AS CENTER OF SURFACE HIGH MOVES OVER
EASTERN NORTH CAROLINA. WEAK COASTAL TROUGH STARTS TO DEVELOP LATER
MON AND MON NIGHT AS SURFACE HIGH BECOMES ELONGATED TO THE
NORTHEAST. NEARSHORE WINDS WILL REMAIN NORTHEAST BUT CLOSER TO 20 NM
VARIABLE OR EVEN SOUTHEAST WINDS MAY DEVELOP BEFORE THE END OF THE
PERIOD. GRADIENT REMAINS WEAK IN THE VICINITY OF THE TROUGH WHICH
WILL KEEP WIND SPEEDS CLOSER TO 10 KT MON NIGHT. SEAS 4 TO 7 FT TO
START THE PERIOD FALL TO 3 TO 5 FT SUN NIGHT AND CONTINUE TO DROP AS
WINDS VEER AND WEAKEN. BY THE END OF THE PERIOD SEAS WILL BE 2 TO 3
FT.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...LARGE AMOUNT OF UNCERTAINTY FOR THE PERIOD AS
FAR AS WIND DIRECTION IS CONCERNED. THINK SCA EVENT IS IN THE WORKS
TUE NIGHT OR WED AS STRENGTHENING LOW PRESSURE SYSTEM EMERGING FROM
THE NORTHERN GULF OF MEXICO TRAVELS UP THE EAST COAST. THE TRACK OF
THE LOW REMAINS THE STICKING POINT AND WILL DETERMINE WIND
DIRECTION. CONFIDENT STRONG EAST TO SOUTHEAST FLOW WILL DEVELOP ON
TUE BUT FROM THERE CONFIDENCE DROPS. AT THIS POINT THE FAVORED
SOLUTION IS A TRACK JUST INLAND OF THE COAST WHICH LEADS TO STRONG
SOUTHERLY FLOW BECOMING SOUTHWEST LATE TUE NIGHT. SOUTHWEST WINDS
VEER TO NORTHWEST ON WED AS THE COLD FRONT PUSHES OFF THE COAST AND
HIGH PRESSURE STARTS TO BUILD IN. THE ELEVATED WIND SPEEDS COMBINED
WITH THE VARYING DIRECTIONS WILL RESULT IN A VERY CHAOTIC SEA STATE
FOR MUCH OF THE PERIOD. SEAS BUILD TUE INTO TUE NIGHT...REACHING 5
TO 8 FT AT THEIR ZENITH...THEN SLOWLY SUBSIDING DURING WED AS
OFFSHORE FLOW DEVELOPS AND INCREASES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR AMZ250-
252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS PORTLAND OR
245 AM PST FRI NOV 22 2013
.SYNOPSIS...HIGH PRESSURE OVER THE PACIFIC NORTHWEST WILL MAINTAIN
DRY AND COOL CONDITIONS INTO NEXT WEEK. A STORM SYSTEM LOOKS
INCREASINGLY LIKELY TO SHIFT SOUTH OF THE REGION...BUT THERE IS
STILL A SMALL CHANCE A FEW SHOWERS COULD SPREAD INTO OUR COASTAL
AND SOUTHERN ZONES DURING THE MIDDLE PART OF NEXT WEEK.
&&
.SHORT TERM...PRESSURE GRADIENTS CONTINUE TO INCREASE ACROSS THE
CASCADES WITH THE KTTD-KDLS GRADIENT APPROACHING 10MB. AS SUCH...
WINDS SHOULD CONTINUE TO STRENGTHEN THIS MORNING WITH GUSTS
APPROACHING 45 MPH AROUND TROUTDALE. 40 TO 60 MPH GUSTS WILL BE
COMMON ACROSS THE WESTERN COLUMBIA RIVER GORGE WITH GUSTS LIKELY
EXCEEDING 80 MPH AT CROWN POINT. AT THIS POINT...ALL MODELS
INCLUDING THE RAP ARE TRYING TO RELAX THE GRADIENT THIS
MORNING...BUT CLIMATOLOGY WOULD SUGGEST OTHERWISE. SO FAR POWER
OUTAGES HAVE BEEN RATHER MINIMAL...BUT IF THE CROSS CASCADE GRADIENT
STARTS TO TRACK MUCH LOWER THAN -10MB THEN WE MAY NEED TO ISSUE A
WIND ADVISORY FOR THE EASTERN SUBURBS OF PORTLAND.
ASIDE FROM A FEW HIGH CLOUDS OCCASIONALLY CREEPING ACROSS THE
NORTHERN HALF OF THE CWA...SKIES ARE CLEAR. WHEN COMBINED WITH
DEWPOINTS IN THE TEENS AND TWENTIES...TEMPERATURES HAVE ONCE AGAIN
FALLEN WELL BELOW FREEZING THIS MORNING AT MANY LOCATIONS.
HOWEVER...IT SHOULD BE NOTED THAT TEMPERATURES HAVE STAYED UP A BIT
HIGHER THAN EXPECTED AROUND MCMINNVILLE...AURORA...DALLAS...AND
SALEM WHERE NORTHERLY WINDS REMAIN 5 TO 10 KT. PRESUMABLY THIS IS
DUE TO THE SUBSIDENCE INVERSION LOWERING TO NEAR 1500 FEET...AND
THUS CAUSING THE GORGE WINDS TO BE BLOCKED BY THE COAST RANGE.
RATHER THAN SPREADING OUT EVENLY NORTH AND SOUTH...THE SYNOPTIC
SCALE NORTH TO SOUTH PRESSURE GRADIENT IS LIKELY AIDING IN MOST OF
THIS MASS SPREADING SOUTHWARD INTO THE CENTRAL AND SOUTHERN
WILLAMETTE VALLEY. PRESUMABLY ENOUGH RADIATIONAL COOLING WILL ALLOW
THE SURFACE TO DECOUPLE AT MANY OF THE AFOREMENTIONED LOCATIONS AT
SOME POINT TONIGHT...BUT GIVEN GORGE WINDS WILL LIKELY STRENGTHEN A
BIT OVER THE NEXT FEW HOURS...WE MAY BE IN FOR QUITE THE MIN
TEMPERATURE FORECAST BUST AT THESE LOCATIONS THIS MORNING.
OTHERWISE...THERE WILL NOT BE MUCH CHANGE OVER THE NEXT SEVERAL DAYS
AS HIGH PRESSURE CONTINUES. THE EAST TO WEST PRESSURE GRADIENT
SHOULD WEAKEN SLOWLY INTO THE MIDDLE PART OF NEXT WEEK...WHICH MEANS
THE STRONGER WINDS SHOULD SUBSIDE TO MORE NUISANCE LEVELS.
A SOUTHERLY WIND SHIFT SHOULD ALSO CAUSE MARINE CLOUDS TO PUSH UP
THE COAST SUNDAY INTO MONDAY...AND THUS LOW TEMPERATURES SHOULD
MODERATE ALONG THE COAST. FURTHER INLAND...THE LOWER ATMOSPHERE
SHOULD MOISTEN OVER THE NEXT COUPLE OF DAYS...INCREASING VALLEY FOG
AND LOW CLOUD DEVELOPMENT. HOWEVER...MOS NUMBERS DO NOT REALLY
SUGGEST THIS OUTCOME. AS A RESULT...WENT A LITTLE MORE MIDDLE OF THE
ROAD...BUMPING UP OUR MAX TEMPERATURES A BIT...WHILE TRYING TO KEEP
THEM BELOW MOS NUMBERS. /NEUMAN
.LONG TERM...MINIMAL CHANGES IN THE EXTENDED...PREVIOUS DISCUSSION
FOLLOWS...DRY WEATHER WILL CONTINUE NEXT WED UNDER HIGH PRES.
SOME BETTER AGREEMENT IN THE OPERATIONAL 12Z GFS AND ECMWF THAN
YESTERDAY. BOTH DEPICT A CLOSED LOW PRESSURE SYSTEM WILL PASS UNDER
THE RIDGE AND TOWARDS THE REGION BEFORE DROPPING SE ALONG THE
CALIFORNIA COAST. DEPENDING ON HOW CLOSE TO THE FORECAST AREA IT
PASSES...THE SOUTHERNMOST ZONES MAY SEE SOME LIGHT SHOWERS.
OTHERWISE THANKSGIVING DAY LOOKS TO BE PARTLY TO MOSTLY CLOUDY AND
DRY. TEMPERATURES WILL GRADUALLY TREND TOWARDS SEASONABLE LEVELS
NEXT WEEK.
&&
.AVIATION...VFR. NO CHANGES AS PERSISTENT PATTERN CONTINUES NEXT
24 HRS. GUSTY EAST WINDS CONTINUE UNDER COLD HIGH PRESSURE.
STRONGEST GUSTS WILL BE THROUGH THE COLUMBIA RIVER GORGE WHERE
GUSTS TO 35-40 KT ARE EXPECTED. BREEZY AND GUSTY CONDITIONS ALSO
EXPECTED ALONG THE COAST...ESPECIALLY NEAR COASTAL GAPS.
KPDX AND APPROACHES...VFR. BREEZY EAST WINDS OVERNIGHT. GUSTS
25-35 KT WILL RESUME SHORTLY AFTER DAYBREAK SATURDAY.
&&
.MARINE...A PERSISTENT WEATHER PATTERN OF HIGH PRESSURE INLAND
AND LOWER PRESSURE OFFSHORE WILL CONTINUE TODAY WITH GUSTY
EASTERLY WINDS NEAR THE COASTAL GAPS. HAVE EXTENDED THE SMALL
CRAFT ADVISORY FOR THESE EASTERLY WINDS THROUGH THIS MORNING. THE
WINDS WILL VEER TO THE SOUTH SUNDAY AFTERNOON AS LOWER PRESSURE
APPROACHES FROM THE WEST. SOUTHERLY WINDS WILL PERSIST THROUGH WED
AND FLIRT WITH SMALL CRAFT ADVISORY CONDITIONS AT TIMES. SEAS WILL
REMAIN BETWEEN 3 AND 6 FEET.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM PST THIS MORNING FROM
CAPE SHOALWATER WA TO FLORENCE OR OUT 10 NM- AND FROM CAPE
SHOALWATER WA TO CASCADE HEAD OR 10 TO 60 NM.
&&
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
600 AM CST SAT NOV 23 2013
.UPDATE...FOR 12Z AVIATION DISCUSSION.
&&
.AVIATION...12Z AVAITION DISCUSSION.
UNCERTAINTIES...MVFR CEILING EROSION TIMINGS CKV/BNA AND IFR CSV...ANY
IMPACTS FROM ISO SHWRS THRU 23/16Z. WITH ISO NATURE OF SHWRS PER REGIONAL
RADAR AND NO OBS SITES REPORTING...AND EXPECTING TO CONTINUE THRU 23/16Z...
WILL NOT MENTION. SFC RIDGING INFLUENCES WILL USHER OUT LOW CLOUDS/EROSION
OF LOW LEVEL CEILINGS 23/17Z W TO 23/20Z E. BKN CI CONTINUING THRU 23/23Z
W TO 24/02Z E. CONTINUED BUILDING RIDGING INFLUENCES/DRY NWLY FLOW ALOFT
SHOULD SUPPORT SKC BY 24/06Z. NLY SFC WINDS GUSTS TO 20KTS PER PRESSURE
GRADIENT INFLUENCES WILL SLOWLY WEAKEN TO SUSTAINED 10-12 KTS AS SFC RIDGING
INFLUENCES BUILD INTO MID STATE AFTER 23/23Z.
&&
.PREV DISCUSSION.../ISSUED 330 AM CST SAT NOV 23 2013/
DISCUSSION...
MID LEVEL VORT CENTER STILL POISED TO SLIDE ACROSS THE MID STATE
THIS MORNING. STILL SEEING SOME DESCENT REFLECTIVITY RETURNS TO OUR
WEST ACROSS WESTERN TN AND NRN MS. NUMERICAL GUIDANCE IS QUITE LOW
WITH THE POPS BUT WILL GO AHEAD AND ADHERE TO CURRENT RADAR TRENDS
AND THE HRRR WHICH ALSO SUPPORTS SOME SHOWER ACTIVITY FOR THIS
MORNING. SO...FOR THIS MORNING WILL INCLUDE A SLIGHT CHANCE OF
SHOWERS. HRRR CLEARS THE ACTIVITY FROM THE MID STATE BY 18Z.
PARTIAL CLEARING WILL COMMENCE IN THE AFTERNOON.
CLEARING TO COMMENCE IN EARNEST BY EVENING AS A STRONG COLD SFC HIGH
CONTINUES TO BUILD SOUTHEASTWARD. TEMPS TO TODAY WILL WARM LITTLE AS
THE CAA AT 850 MB RAMPS UP. BY SUNDAY MORNING...SFC HIGH WILL STILL
BE OVER NRN MO. LOW TEMPS WILL REACH THE UPPER TEENS TO LOWER 20S
AND A NORTHERLY 10-15 MPH WIND WILL BE ONGOING. THIS WILL EQUATE TO
WINDCHILL READINGS OF 5 TO 10 DEGREES....QUITE COLD FOR LATE
NOVEMBER.
SUNDAY DURING THE DAY...COLD WEATHER WILL CONTINUE. NORTH WINDS OF
10 TO 15 MPH WILL COMBINE WITH HIGHS IN THE 30S TO PRODUCE WINDCHILL
READINGS ONLY IN THE 20S FOR THE AFTERNOON. COLD INDEED FOR YOUR
SUNDAY.
SUNDAY NIGHT...SOME PARTIAL HIGH CLOUDINESS WILL BEGIN TO RETURN
LATE AS A STORM SYSTEM STARTS DEVELOPING IN THE WESTERN GULF. THIS
SYSTEM WILL TRACK NORTHEAST AND BRING A CHANCE OF PRECIPITATION TO
THE MID STATE MONDAY NIGHT INTO TUESDAY. THE LATEST GFS SOLUTION IS
FURTHER SOUTH WITH THE TRACK AND KEEPS THE BULK OF THE MOISTURE
SOUTH OF MIDDLE TN. THE EURO SOLUTION HOWEVER...IS FURTHER NORTH
WITH THE MOISTURE. THUS...FOR THE FCST...POPS WILL BE KEPT DOWN INTO
THE CHANCE CATEGORY...WITH THE HIGHEST POPS GENERALLY SOUTH. AS FOR
THE PRECIP TYPE MON NIGHT AND TUESDAY...SOUNDINGS STILL SUPPORT A
RAIN AND SLEET MIX. THE DEEP MOISTURE/SUB FREEZING THERMAL
CONNECTION IS NOT IN FOCUS WITH THIS EVENT. THE EURO
SOLUTION...WHICH IS MORE BULLISH WITH THE MOISTURE...IS WARMER MON
NT AND SUPPORTS A MOSTLY RAIN EVENT. GFS...IN CONTRAST...IS DRIER
BUT COLDER. THEREFORE...WITHOUT A POSITIVE MOISTURE/SUBFREEZING
CONNECTION...WILL CONTINUE TO LEAN TOWARD A RAIN/SLEET MIX. THUS...I
WILL BE GOING ABOVE GUIDANCE FOR THE MON NIGHT MINIMUMS.
ON TUESDAY...THE LOWER LEVEL ISOTROPICALLY INDUCED PRECIP WILL BE
PULLING EAST. AT THAT TIME THE FOCUS WILL SHIFT TOWARD THE UPPER
LEVEL SYSTEM. LATEST RUNS BRING THE UPPER LOW EASTWARD ACROSS THE
PANHANDLE OF FL. THIS IS MUCH FURTHER SOUTH THAN PREVIOUS RUNS. WILL
THEREFORE LEAN TOWARD DECREASING THE RAIN/SNOW FCST FROM EARLIER FOR
TUES NT. FURTHERMORE...THE UPPER SYSTEM LOOKS WEAKER IN TERMS OF
MOISTURE EXPANSE AS A TRANSITION TOWARD ANY NEGATIVE TILT
ORIENTATION NOW LOOKS ABSENT.
ON WEDNESDAY...A RETURN TO MOSTLY SUNNY SKIES WILL BE IN STORE. COLD
BUT NOT TOO TERRIBLY COLD FOR THE REST OF THE WEEK. THANKSGIVING
WILL FEATURE MOSTLY CLEAR SKIES...LOWS IN THE 20S HIGHS IN THE 40S.
50 TO 55 DEGREES FOR HIGHS ON FRIDAY...THE BUSIEST SHOPPING DAY OF
THE YEAR...AS AN UPPER RIDGE AXIS DEVELOPS OVER THE SPINE OF THE MS
RIVER.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
736 AM CST SAT NOV 23 2013
.UPDATE...
LATEST HRRR...TTU-WRF...RUC...NAM AND GFS ALL STILL SHOWING DRIER
WORKING NORTHEAST TO SOUTHWEST ACROSS THE PANHANDLES DURING THE DAY
TODAY WITH A DECREASE IN THE PRECIP. HOWEVER...MODELS NOT PICKING UP
ON PRECIP LIFTING NORTHEAST OUT OF NM AND ERRING ON THE SIDE OF
CAUTION AS ROADS AND HIGHWAYS REMAIN SLICK AND ICY FROM FREEZING RAIN
AND FREEZING DRIZZLE LAST NIGHT. PRECIP COMING OUT OF NM MAY CREATE
ANOTHER ROUND OF FREEZING RAIN...FREEZING DRIZZLE OR SLEET ADDING TO
THE ICY CONDITIONS. DECIDED TO TO ISSUE A WINTER WEATHER ADVISORY
FOR WINTRY PRECIP THROUGH 12Z MONDAY DUE TO THE UNCERTAINITES AND LOW
CONFIDENCE IN THE SHORT RANGE AND HIGH RES MODELS.
UPDATED PUBLIC PRODUCTS HAVE BEEN ISSUED.
SCHNEIDER
&&
.PREV DISCUSSION... /ISSUED 522 AM CST SAT NOV 23 2013/
UPDATE...
MOST OF THE PRECIPITATION HAS LEFT THE AREA...THUS THE WINTER WEATHER
WILL BE ALLOWED TO EXPIRE AT THE TOP OF THE HOUR. HOWEVER...ICY ROADS
REMAIN IN THE PANHANDLES...THUS WILL ISSUE AN SPS TO COVER THE SLICK
CONDITIONS THAT WILL REMAIN FOR AT LEAST THE MORNING HOURS.
JOHNSON
AVIATION...
FOR THE 12Z TAFS...CONDITIONS WILL CONTINUE TO IMPROVE THROUGH THE
MORNING HOURS...WITH VFR CONDITIONS EXPECTED AT ALL THREE TAF SITES
FROM 18 TO 00Z. AFTER 00Z...MOISTURE FROM THE NEXT SYSTEM WILL BEGIN
TO STREAM INTO THE REGION...BRINGING LOWER CEILINGS...BR...AND
EVENTUALLY SN. AS WITH YESTERDAY...TEMPERATURES WILL REMAIN BELOW OR
NEAR FREEZING ALL DAY...THUS ANY BR THAT DEVELOPS CARRIES THE ADDED
THREAT OF ICING.
JOHNSON
PREV DISCUSSION... /ISSUED 409 AM CST SAT NOV 23 2013/
DISCUSSION...
CLOSED UPPER LOW OVER SOUTHERN CALIFORNIA AND NORTHERN BAJA WILL
BEGIN TO EJECT SLOWLY EAST TODAY...MOVING ACROSS THE SOUTHWESTERN
STATES BY 12Z SUNDAY...AND THEN ACROSS THE SOUTHERN ROCKIES SUNDAY
NIGHT. SHORTWAVE RIDGE AHEAD OF THE UPPER LOW WILL REMAIN OVER THE
FORECAST AREA TODAY AND THEN WILL SHIFT EAST AWAY FROM THE PANHANDLES
SUNDAY. ANY WINTRY PRECIPITATION TODAY WILL BE RATHER LIGHT AND LOW
CONFIDENCE PREVAILS ON PRECIP TYPE. FREEZING DRIZZLE AND LIGHT
FREEZING RAIN HAS ALREADY GLAZED ROADS AND HIGHWAYS IN THE FORECAST
AREA SINCE ABOUT 05Z TO 10Z SATURDAY BUT MOVING NORTHEAST OUT OF THE
FORECAST AREA. THE LATEST HRRR SHOWING DRYING TREND THROUGH THE DAY
TODAY UNTIL THE NEXT ROUND OF PRECIP MOVES INTO THE PANHANDLES AFTER
00Z SUNDAY. WILL HOLD OFF ON ANY ADVISORIES...WATCHES OR WARNINGS
TODAY AS THE CURRENT WINTER WEATHER ADVISORY SET TO EXPIRE AT 12Z
TODAY. BEST CHANCES FOR ANOTHER ROUND OF FREEZING AND OR FROZEN
PRECIPITATION...MAINLY SNOW AND SLEET...WILL OCCUR TONIGHT THROUGH
SUNDAY AND SUNDAY NIGHT AS THE LEADING SHORTWAVE ASSOCIATED WITH THE
UPPER LOW TRACKS EAST OUT OF THE FOUR CORNERS REGION AND SOUTHERN
ROCKIES BY 06Z SUNDAY WITH THE MAIN SHORTWAVE AFFECTING THE
PANHANDLES BY 00Z MONDAY. NAM STILL OVERLY BULLISH ON POPS AND QPF
WHILE THE GFS AND ECMWF DIFFER ON TIMING AND TRACK OF THE UPPER LOW.
THE GFS IS FASTER THAN THE ECMWF AND FURTHER SOUTH WITH THE CLOSED
UPPER LOW. LOW CONFIDENCE IN THE MEDIUM RANGE MODELS BUT LEAN TOWARD
THE ECMWF SOLUTION.
BOTH THE ECMWF AND GFS SHUTTING OFF THE PRECIP BY LATE MONDAY AS THE
CLOSED UPPER LOW DIGS SOUTH OF THE PANHANDLES BY 00Z TUESDAY AND BEST
LIFT WELL SOUTH AND EAST OF THE FORECAST AREA. DRIER AIR TO WORK INTO
THE PANHANDLES BY MONDAY NIGHT ALLOWING FOR CLEARING SKIES BY 12Z
TUESDAY. SLOWLY MODERATING TEMPS AND DRY TUESDAY THROUGH THE END OF
NEXT WEEK AS LEE SURFACE TROUGH DEVELOPS BY THE MIDDLE OF NEXT WEEK
AND WARMER SOUTHERLY FLOW PREVAILS. ANOTHER COLD FRONT MAY PUSH
THROUGH THE PANHANDLES BY NEXT SATURDAY.
SCHNEIDER
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY
THROUGH LATE NEXT WEEK.
SCHNEIDER
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
16/11
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
522 AM CST SAT NOV 23 2013
.UPDATE...
MOST OF THE PRECIPITATION HAS LEFT THE AREA...THUS THE WINTER WEATHER
WILL BE ALLOWED TO EXPIRE AT THE TOP OF THE HOUR. HOWEVER...ICY ROADS
REMAIN IN THE PANHANDLES...THUS WILL ISSUE AN SPS TO COVER THE SLICK
CONDITIONS THAT WILL REMAIN FOR AT LEAST THE MORNING HOURS.
JOHNSON
&&
.AVIATION...
FOR THE 12Z TAFS...CONDITIONS WILL CONTINUE TO IMPROVE THROUGH THE
MORNING HOURS...WITH VFR CONDITIONS EXPECTED AT ALL THREE TAF SITES
FROM 18 TO 00Z. AFTER 00Z...MOISTURE FROM THE NEXT SYSTEM WILL BEGIN
TO STREAM INTO THE REGION...BRINGING LOWER CEILINGS...BR...AND
EVENTUALLY SN. AS WITH YESTERDAY...TEMPERATURES WILL REMAIN BELOW OR
NEAR FREEZING ALL DAY...THUS ANY BR THAT DEVELOPS CARRIES THE ADDED
THREAT OF ICING.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 409 AM CST SAT NOV 23 2013/
DISCUSSION...
CLOSED UPPER LOW OVER SOUTHERN CALIFORNIA AND NORTHERN BAJA WILL
BEGIN TO EJECT SLOWLY EAST TODAY...MOVING ACROSS THE SOUTHWESTERN
STATES BY 12Z SUNDAY...AND THEN ACROSS THE SOUTHERN ROCKIES SUNDAY
NIGHT. SHORTWAVE RIDGE AHEAD OF THE UPPER LOW WILL REMAIN OVER THE
FORECAST AREA TODAY AND THEN WILL SHIFT EAST AWAY FROM THE PANHANDLES
SUNDAY. ANY WINTRY PRECIPITATION TODAY WILL BE RATHER LIGHT AND LOW
CONFIDENCE PREVAILS ON PRECIP TYPE. FREEZING DRIZZLE AND LIGHT
FREEZING RAIN HAS ALREADY GLAZED ROADS AND HIGHWAYS IN THE FORECAST
AREA SINCE ABOUT 05Z TO 10Z SATURDAY BUT MOVING NORTHEAST OUT OF THE
FORECAST AREA. THE LATEST HRRR SHOWING DRYING TREND THROUGH THE DAY
TODAY UNTIL THE NEXT ROUND OF PRECIP MOVES INTO THE PANHANDLES AFTER
00Z SUNDAY. WILL HOLD OFF ON ANY ADVISORIES...WATCHES OR WARNINGS
TODAY AS THE CURRENT WINTER WEATHER ADVISORY SET TO EXPIRE AT 12Z
TODAY. BEST CHANCES FOR ANOTHER ROUND OF FREEZING AND OR FROZEN
PRECIPITATION...MAINLY SNOW AND SLEET...WILL OCCUR TONIGHT THROUGH
SUNDAY AND SUNDAY NIGHT AS THE LEADING SHORTWAVE ASSOCIATED WITH THE
UPPER LOW TRACKS EAST OUT OF THE FOUR CORNERS REGION AND SOUTHERN
ROCKIES BY 06Z SUNDAY WITH THE MAIN SHORTWAVE AFFECTING THE
PANHANDLES BY 00Z MONDAY. NAM STILL OVERLY BULLISH ON POPS AND QPF
WHILE THE GFS AND ECMWF DIFFER ON TIMING AND TRACK OF THE UPPER LOW.
THE GFS IS FASTER THAN THE ECMWF AND FURTHER SOUTH WITH THE CLOSED
UPPER LOW. LOW CONFIDENCE IN THE MEDIUM RANGE MODELS BUT LEAN TOWARD
THE ECMWF SOLUTION.
BOTH THE ECMWF AND GFS SHUTTING OFF THE PRECIP BY LATE MONDAY AS THE
CLOSED UPPER LOW DIGS SOUTH OF THE PANHANDLES BY 00Z TUESDAY AND BEST
LIFT WELL SOUTH AND EAST OF THE FORECAST AREA. DRIER AIR TO WORK INTO
THE PANHANDLES BY MONDAY NIGHT ALLOWING FOR CLEARING SKIES BY 12Z
TUESDAY. SLOWLY MODERATING TEMPS AND DRY TUESDAY THROUGH THE END OF
NEXT WEEK AS LEE SURFACE TROUGH DEVELOPS BY THE MIDDLE OF NEXT WEEK
AND WARMER SOUTHERLY FLOW PREVAILS. ANOTHER COLD FRONT MAY PUSH
THROUGH THE PANHANDLES BY NEXT SATURDAY.
SCHNEIDER
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY
THROUGH LATE NEXT WEEK.
SCHNEIDER
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
THE FOLLOWING ZONES: DALLAM...HANSFORD...HARTLEY...MOORE...
OLDHAM...SHERMAN.
OK...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
THE FOLLOWING ZONES: CIMARRON...TEXAS.
&&
$$
16/11
AREA FORECAST DISCUSSION...CORRECTED
NWS AMARILLO TX
409 AM CST SAT NOV 23 2013
.DISCUSSION...
CLOSED UPPER LOW OVER SOUTHERN CALIFORNIA AND NORTHERN BAJA WILL
BEGIN TO EJECT SLOWLY EAST TODAY...MOVING ACROSS THE SOUTHWESTERN
STATES BY 12Z SUNDAY...AND THEN ACROSS THE SOUTHERN ROCKIES SUNDAY
NIGHT. SHORTWAVE RIDGE AHEAD OF THE UPPER LOW WILL REMAIN OVER THE
FORECAST AREA TODAY AND THEN WILL SHIFT EAST AWAY FROM THE PANHANDLES
SUNDAY. ANY WINTRY PRECIPITATION TODAY WILL BE RATHER LIGHT AND LOW
CONFIDENCE PREVAILS ON PRECIP TYPE. FREEZING DRIZZLE AND LIGHT
FREEZING RAIN HAS ALREADY GLAZED ROADS AND HIGHWAYS IN THE FORECAST
AREA SINCE ABOUT 05Z TO 10Z SATURDAY BUT MOVING NORTHEAST OUT OF THE
FORECAST AREA. THE LATEST HRRR SHOWING DRYING TREND THROUGH THE DAY
TODAY UNTIL THE NEXT ROUND OF PRECIP MOVES INTO THE PANHANDLES AFTER
00Z SUNDAY. WILL HOLD OFF ON ANY ADVISORIES...WATCHES OR WARNINGS
TODAY AS THE CURRENT WINTER WEATHER ADVISORY SET TO EXPIRE AT 12Z
TODAY. BEST CHANCES FOR ANOTHER ROUND OF FREEZING AND OR FROZEN
PRECIPITATION...MAINLY SNOW AND SLEET...WILL OCCUR TONIGHT THROUGH
SUNDAY AND SUNDAY NIGHT AS THE LEADING SHORTWAVE ASSOCIATED WITH THE
UPPER LOW TRACKS EAST OUT OF THE FOUR CORNERS REGION AND SOUTHERN
ROCKIES BY 06Z SUNDAY WITH THE MAIN SHORTWAVE AFFECTING THE
PANHANDLES BY 00Z MONDAY. NAM STILL OVERLY BULLISH ON POPS AND QPF
WHILE THE GFS AND ECMWF DIFFER ON TIMING AND TRACK OF THE UPPER LOW.
THE GFS IS FASTER THAN THE ECMWF AND FURTHER SOUTH WITH THE CLOSED
UPPER LOW. LOW CONFIDENCE IN THE MEDIUM RANGE MODELS BUT LEAN TOWARD
THE ECMWF SOLUTION.
BOTH THE ECMWF AND GFS SHUTTING OFF THE PRECIP BY LATE MONDAY AS THE
CLOSED UPPER LOW DIGS SOUTH OF THE PANHANDLES BY 00Z TUESDAY AND BEST
LIFT WELL SOUTH AND EAST OF THE FORECAST AREA. DRIER AIR TO WORK INTO
THE PANHANDLES BY MONDAY NIGHT ALLOWING FOR CLEARING SKIES BY 12Z
TUESDAY. SLOWLY MODERATING TEMPS AND DRY TUESDAY THROUGH THE END OF
NEXT WEEK AS LEE SURFACE TROUGH DEVELOPS BY THE MIDDLE OF NEXT WEEK
AND WARMER SOUTHERLY FLOW PREVAILS. ANOTHER COLD FRONT MAY PUSH
THROUGH THE PANHANDLES BY NEXT SATURDAY.
SCHNEIDER
&&
.FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY
THROUGH LATE NEXT WEEK.
SCHNEIDER
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 31 17 25 22 34 / 30 70 60 30 20
BEAVER OK 31 18 28 23 37 / 10 40 50 30 10
BOISE CITY OK 31 18 28 21 39 / 20 50 50 20 10
BORGER TX 33 21 29 23 38 / 20 60 60 30 20
BOYS RANCH TX 32 20 26 24 36 / 30 70 60 30 20
CANYON TX 31 18 25 22 34 / 30 70 60 30 20
CLARENDON TX 33 20 25 25 36 / 30 60 60 40 20
DALHART TX 31 17 26 20 38 / 30 60 50 20 20
GUYMON OK 31 18 29 23 40 / 20 50 50 20 10
HEREFORD TX 31 18 27 21 36 / 40 70 60 30 20
LIPSCOMB TX 32 17 29 26 37 / 10 50 60 30 10
PAMPA TX 32 18 24 23 33 / 20 60 60 30 20
SHAMROCK TX 34 21 27 25 36 / 20 60 60 40 20
WELLINGTON TX 34 21 27 24 36 / 20 60 70 40 20
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
THE FOLLOWING ZONES: DALLAM...HANSFORD...HARTLEY...MOORE...
OLDHAM...SHERMAN.
OK...WINTER WEATHER ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
THE FOLLOWING ZONES: CIMARRON...TEXAS.
&&
$$
16/11
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
959 AM MST SAT NOV 23 2013
.SYNOPSIS...
PACIFIC LOW PRESSURE WILL CONTINUE TO PRODUCE SCATTERED TO NUMEROUS
SHOWERS TODAY FROM PHOENIX EASTWARD...WITH LESSER COVERAGE OVER THE
WESTERN DESERTS. THERE WILL BE A LINGERING CHANCE FOR RAIN
SUNDAY...MAINLY OVER SOUTH-CENTRAL ARIZONA BUT ACCUMULATIONS...IF
ANY...WILL BE MUCH LOWER. HIGH TEMPERATURES WILL REMAIN WELL BELOW
NORMAL THIS WEEKEND. DRY WEATHER AND WARMER TEMPERATURES WILL RETURN
MONDAY THROUGH THE LATTER PART OF NEXT WEEK.
&&
.DISCUSSION...
THE UPPER LOW CENTER HAS STARTED TO MAKE SOME MOVEMENT TO THE
NORTHEAST OVER THE PAST SIX HOURS. THE MAIN BAND OF RAIN HAS ALSO
SHIFTED MORE TO THE EAST AND CURRENTLY RESIDES FROM ACROSS THE FAR
EAST METRO PHOENIX AREA EASTWARD THROUGH GILA COUNTY. RAINFALL RATES
ARE GENERALLY ON THE LIGHT SIDE...OR LESS THAN A TENTH OF AN INCH
PER HOUR. CLOSER TO THE LOW CENTER AND MID LEVEL COOL CORE...HEAVIER
AND MORE SHOWERY TYPE RAIN HAS AFFECTED NORTHWEST MARICOPA COUNTY
SINCE 7 AM. LATEST HRRR MODEL REFLECTIVITY SHOWS THE EASTERN RAIN
BAND EVENTUALLY PUSHING EASTWARD AND WEAKENING THIS AFTERNOON. MORE
SCATTERED SHOWERY TYPE RAIN WILL BE POSSIBLE THROUGHOUT THE DAY
MAINLY FOCUSED ACROSS SOUTHWEST ARIZONA. HAVE TRIMMED BACK ON POPS
FOR THIS AFTERNOON ACROSS THE REST OF THE METRO PHOENIX AREA WHERE
RAIN HAS STOPPED. HOWEVER...UNTIL THE LOW MOVES OUT OF THE AREA
SUNDAY NIGHT...SLIGHT CHANCE TO CHANCE POPS ARE IN THE FORECAST FOR
MUCH OF THE AREA. WILL SEE VERY LITTLE DAYTIME IMPROVEMENT IN
TEMPERATURES...MAYBE INCREASING 5-7 DEGREES IN MOST AREAS FROM
OVERNIGHT LOWS.
&&
.PREVIOUS DISCUSSION...
IMPRESSIVE PACIFIC CLOSED UPPER LOW CONTINUED TO SPIN MORE OR LESS
IN PLACE ALONG THE FAR SERN CA/FAR NRN BAJA COAST AT 3 AM THIS
MORNING...KEEPING A PRONOUNCED DIFLUENT SIGNATURE IN PLACE OVER
ARIZONA. BANDS OF RAIN SHOWERS CONTINUED TO MOVE NORTH ACROSS SOUTH
CENTRAL ARIZONA...HOWEVER THE INTENSITIES WERE LESS THAN WHAT WAS
OBSERVED EARLIER...DURING THE DAY ON FRIDAY. MOST HOURLY RAINFALL
TOTALS HAVE BEEN BELOW ONE TENTH OF AN INCH SINCE MIDNIGHT...AND
LATEST 3 HOURS ACCUMULATIONS FROM THE MARICOPA COUNTY FLOOD CONTROL
GAGES SHOWED VALUES BELOW ONE TENTH OF AN INCH ACROSS WESTERN
MARICOPA COUNTY...AND BETWEEN ONE QUARTER AND ONE HALF INCH OVER THE
GREATER PHOENIX AREA. LITTLE RAINFALL WAS OCCURRING OVER SERN CA AND
THE WESTERN DESERTS...AND IR/VAPOR IMAGERY DEPICTED DRY SLOTTING
OCCURRING OVER OUR WESTERN CWA. PROGS ALL INDICATE THAT THE UPPER
LOW WILL START TO MOVE INLAND TODAY...SHIFTING THE DEEPER MOISTURE
EASTWARD ALONG WITH THE BEST DYNAMICS AND UPPER DIFLUENCE. GIVEN
THAT THE RAINFALL INTENSITIES HAVE BEEN DIMINISHED FOR SOME TIME AND
THAT THERE WILL CONTINUE TO BE DECREASING SHOWERS FROM THE WEST
DURING THE DAY TODAY...WE OPTED TO CANCEL THE FLOOD WATCH EARLY. IT
IS POSSIBLE THAT SMALLER HYDRO ISSUES MAY CROP UP DURING THE
DAY...PROBABLY ACROSS THE EASTERN PORTIONS OF THE GREATER PHOENIX
AREA OR SOUTHERN GILA COUNTY...BUT THEY MOST LIKELY WOULD BE ABLE TO
BE HANDLED WITH FLOOD ADVISORIES. CURRENT POP TRENDS FOR TODAY AND
TONIGHT LOOK GOOD AND FEW CHANGES WERE MADE. EXPECT SLIGHT CHANCES
FOR SHOWERS ACROSS THE WESTERN CWA BY THIS EVENING WITH LINGERING
CHANCES FROM PHOENIX EASTWARD. AS THE LOW EDGES EASTWARD...SOME COLD
AIR ALOFT WILL SHIFT INTO THE WESTERN/CENTRAL DESERTS LEADING TO
SOME INSTABILITY AND A SLIGHT CHANCE FOR EMBEDDED THUNDERSTORMS.
THUS FORECASTS FROM PHOENIX WESTWARD MENTION SLIGHT CHANCES FOR
THUNDER THIS AFTERNOON. EXPECT HIGH TEMPS TODAY TO REMAIN AT LEAST
10 DEGREES BELOW NORMALS...GIVEN THE COOL DAMP AIRMASS IN PLACE AND
THE PERSISTENT CLOUDS AND SHOWERS.
UPPER LOW WILL CONTINUE TO BODILY MOVE EASTWARD ACROSS THE STATE
SUNDAY...LEADING TO A DRYING TREND FROM THE WEST...WITH PRECIP
CHANCES LOWERING TO SLIGHT CHANCES BY AFTERNOON FROM THE GREATER
PHOENIX AREA WESTWARD. MAY SEE AN ISOLATED AFTERNOON THUNDERSTORM
SUNDAY ACROSS THE CENTRAL DESERTS AS THE COLD POOL ALOFT SHIFTS
OVERHEAD. OF COURSE...WITH THE THE MAIN LOW MOVING DIRECTLY
OVERHEAD...TEMPS SUNDAY WILL STAY VERY COOL WITH MOST DESERT LOCALES
STRUGGLING TO REACH INTO THE LOW TO MID 60S.
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE WEST MONDAY INTO THE
MIDDLE OF NEXT WEEK FOR DRY CONDITIONS AND A WARMING TREND. EXPECT
HIGHS TO CLIMB GRADUALLY...REACHING SEASONAL NORMALS BY TUESDAY
UNDER MOSTLY SUNNY OR SUNNY SKIES.
VARIOUS EXTENDED RANGE MODELS...SUCH AS GFS...ECMWF AND
CANADIAN...AS WELL AS THEIR ENSEMBLES...ALL SUGGEST THAT ANOTHER
PACIFIC LOW PRESSURE SYSTEM MAY IMPACT THE DESERT SOUTHWEST LATER
NEXT WEEK. HOWEVER...ENSEMBLE MEMBER SPREADS ARE EXTREME AND THERE
IS LITTLE RUN TO RUN CONSISTENCY WITH THESE MODELS AND LITTLE MODEL
TO MODEL CONSISTENCY. LATEST GFS MOVES A SIGNIFICANT LOW INTO
ARIZONA BY NEXT FRIDAY...WHILE THE ECMWF CLOSES OFF THE LOW AND
SHIFTS IT WELL OFF THE CA COAST AT THAT TIME. GIVEN MODEL
UNCERTAINTIES...LEFT SOME MODEST POPS ACROSS THE CWA THURSDAY INTO
FRIDAY...MAINLY OVER THE WESTERN DESERTS. POPS ARE NEAR OR A BIT
ABOVE CLIMO. SHOULD THE LATEST EUROPEAN GUIDANCE BE SPOT ON...WE
WILL NOT SEE ANY PRECIP THRU AT LEAST FRIDAY...BUT IT HAS SHOWN
SIGNIFICANT DEVIATIONS RUN TO RUN SO ITS CURRENT SOLUTION CANNOT BE
TRUSTED.
&&
.AVIATION...
SOUTH-CENTRAL AZ...INCLUDING KPHX...KIWA...AND KSDL...
RAIN SHOWER ACTIVITY HAS GRADUALLY DIMINISHED IN AREAL COVERAGE
OVERNIGHT WHILE ALSO TRANSITIONING EAST OF THE PHX METRO. LIGHT
SHOWERS WILL CONTINUE TO STREAM FROM SOUTH TO NORTH GNLY THROUGH
23/1800Z WARRANTING -SHRA MENTION. EARLY MORNING CIGS HAVE THE
POTENTIAL TO BOUNCE BETWEEN VFR AND MVFR LEVELS. CONFIDENCE IS
MODERATE OF CIGS BREAKING OUT IN TO THE 5-6KFT RANGE BY MIDDAY.
SHOWERS WILL BECOME MORE VICINITY IN NATURE BY EVENING AS THEY
TRANSITION FURTHER TO THE EAST. EXPECT PERIODIC TERRAIN OBSCURATIONS
FROM CLOUDS POSSIBLE INTO THE OVERNIGHT HOURS. WINDS WILL GENERALLY
HOLD EAST HEADINGS WITH 8 TO 12 KNOTS OF SPEED POSSIBLE.
SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
WIDELY SCATTERED LIGHT SHOWER ACTIVITY WILL PERSIST ACROSS SE
CALIFORNIA THROUGH THIS EVENING...PARTICULARLY AT KBLH WHERE MVFR
CIGS/VSBY IMPACTS ARE EXPECTED THROUGH MID MORNING. UPPER LOW
PRESSURE RESPONSIBLE FOR GENERATING THE PRECIP ACTIVITY WILL BEGIN
TO MOVE FURTHER INLAND OVER SOUTHEAST CALIFORNIA...INTRODUCING
COOLER TEMPERATURES ALOFT AND THE POTENTIAL FOR ISOLATED THUNDER
DEVELOPMENT DURING THE AFTERNOON HOURS. CONFIDENCE IS LOW TO
MODERATE FOR ORGANIZED ACTIVITY NEAR THE TERMINALS...SO LEFT ANY
VCTS OR CB MENTION OUT OF THE 12Z TAF PACKAGE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
LOW PRESSURE WILL CONTINUE TO EXIT TO THE EAST MONDAY...LEAVING WELL
BELOW NORMAL TEMPERATURES AND A DRYING TREND IN TERMS OF
PRECIPITATION. COLDER AIR WILL LIE AGAINST THE CONTINENTAL DIVIDE
THROUGH MIDWEEK...KEEPING SURFACE GRADIENTS TIGHTENED AND MORE
PRONOUNCED EASTERLY WINDS DEVELOPING ACROSS EASTERN AND CENTRAL
ARIZONA. HIGH PRESSURE WILL BUILD ACROSS THE REGION...RESULTING IN A
WARMING TREND THROUGH MIDWEEK AND A RETURN TO NEAR NORMAL
TEMPERATURES BY TUESDAY. LATER INTO NEXT WEEK ANOTHER STORM SYSTEM
IS FORECAST TO DEVELOP OFF THE PACIFIC BRINGING WITH IT COOLER
TEMPERATURES FOR THE LATE WEEK AND POTENTIALLY ANOTHER ROUND OF
RAIN/SNOW SHOWER ACTIVITY TO THE REGION BY NEXT WEEKEND.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...CB
AVIATION...NOLTE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
917 AM MST SAT NOV 23 2013
.SYNOPSIS...
PACIFIC LOW PRESSURE WILL CONTINUE TO PRODUCE SCATTERED TO NUMEROUS
SHOWERS TODAY FROM PHOENIX EASTWARD...WITH LESSER COVERAGE OVER THE
WESTERN DESERTS. THERE WILL BE A LINGERING CHANCE FOR RAIN
SUNDAY...MAINLY OVER SOUTH-CENTRAL ARIZONA BUT ACCUMULATIONS...IF
ANY...WILL BE MUCH LOWER. HIGH TEMPERATURES WILL REMAIN WELL BELOW
NORMAL THIS WEEKEND. DRY WEATHER AND WARMER TEMPERATURES WILL RETURN
MONDAY THROUGH THE LATTER PART OF NEXT WEEK.
&&
.DISCUSSION...
THE UPPER LOW CENTER HAS STARTED TO MAKE SOME MOVEMENT TO THE
NORTHEAST OVER THE PAST SIX HOURS. THE MAIN BAND OF RAIN HAS ALSO
SHIFTED MORE TO THE EAST AND CURRENTLY RESIDES FROM ACROSS THE FAR
EAST METRO PHOENIX AREA EASTWARD THROUGH GILA COUNTY. RAINFALL RATES
ARE GENERALLY ON THE LIGHT SIDE...OR LESS THAN A TENTH OF AN INCH
PER HOUR. CLOSER TO THE LOW CENTER AND MID LEVEL COOL CORE...HEAVIER
AND MORE SHOWERY TYPE RAIN HAS AFFECTED NORTHEAST MARICOPA COUNTY
SINCE 7 AM. LATEST HRRR MODEL REFLECTIVITY SHOWS THE EASTERN RAIN
BAND EVENTUALLY PUSHING EASTWARD AND WEAKENING THIS AFTERNOON. MORE
SCATTERED SHOWERY TYPE RAIN WILL BE POSSIBLE THROUGHOUT THE DAY
MAINLY FOCUSED ACROSS SOUTHWEST ARIZONA. HAVE TRIMMED BACK ON POPS
FOR THIS AFTERNOON ACROSS THE REST OF THE METRO PHOENIX AREA WHERE
RAIN HAS STOPPED. HOWEVER...UNTIL THE LOW MOVES OUT OF THE AREA
SUNDAY NIGHT...SLIGHT CHANCE TO CHANCE POPS ARE IN THE FORECAST FOR
MUCH OF THE AREA. WILL SEE VERY LITTLE DAYTIME IMPROVEMENT IN
TEMPERATURES...MAYBE INCREASING 5-7 DEGREES IN MOST AREAS FROM
OVERNIGHT LOWS.
&&
.PREVIOUS DISCUSSION...
IMPRESSIVE PACIFIC CLOSED UPPER LOW CONTINUED TO SPIN MORE OR LESS
IN PLACE ALONG THE FAR SERN CA/FAR NRN BAJA COAST AT 3 AM THIS
MORNING...KEEPING A PRONOUNCED DIFLUENT SIGNATURE IN PLACE OVER
ARIZONA. BANDS OF RAIN SHOWERS CONTINUED TO MOVE NORTH ACROSS SOUTH
CENTRAL ARIZONA...HOWEVER THE INTENSITIES WERE LESS THAN WHAT WAS
OBSERVED EARLIER...DURING THE DAY ON FRIDAY. MOST HOURLY RAINFALL
TOTALS HAVE BEEN BELOW ONE TENTH OF AN INCH SINCE MIDNIGHT...AND
LATEST 3 HOURS ACCUMULATIONS FROM THE MARICOPA COUNTY FLOOD CONTROL
GAGES SHOWED VALUES BELOW ONE TENTH OF AN INCH ACROSS WESTERN
MARICOPA COUNTY...AND BETWEEN ONE QUARTER AND ONE HALF INCH OVER THE
GREATER PHOENIX AREA. LITTLE RAINFALL WAS OCCURRING OVER SERN CA AND
THE WESTERN DESERTS...AND IR/VAPOR IMAGERY DEPICTED DRY SLOTTING
OCCURRING OVER OUR WESTERN CWA. PROGS ALL INDICATE THAT THE UPPER
LOW WILL START TO MOVE INLAND TODAY...SHIFTING THE DEEPER MOISTURE
EASTWARD ALONG WITH THE BEST DYNAMICS AND UPPER DIFLUENCE. GIVEN
THAT THE RAINFALL INTENSITIES HAVE BEEN DIMINISHED FOR SOME TIME AND
THAT THERE WILL CONTINUE TO BE DECREASING SHOWERS FROM THE WEST
DURING THE DAY TODAY...WE OPTED TO CANCEL THE FLOOD WATCH EARLY. IT
IS POSSIBLE THAT SMALLER HYDRO ISSUES MAY CROP UP DURING THE
DAY...PROBABLY ACROSS THE EASTERN PORTIONS OF THE GREATER PHOENIX
AREA OR SOUTHERN GILA COUNTY...BUT THEY MOST LIKELY WOULD BE ABLE TO
BE HANDLED WITH FLOOD ADVISORIES. CURRENT POP TRENDS FOR TODAY AND
TONIGHT LOOK GOOD AND FEW CHANGES WERE MADE. EXPECT SLIGHT CHANCES
FOR SHOWERS ACROSS THE WESTERN CWA BY THIS EVENING WITH LINGERING
CHANCES FROM PHOENIX EASTWARD. AS THE LOW EDGES EASTWARD...SOME COLD
AIR ALOFT WILL SHIFT INTO THE WESTERN/CENTRAL DESERTS LEADING TO
SOME INSTABILITY AND A SLIGHT CHANCE FOR EMBEDDED THUNDERSTORMS.
THUS FORECASTS FROM PHOENIX WESTWARD MENTION SLIGHT CHANCES FOR
THUNDER THIS AFTERNOON. EXPECT HIGH TEMPS TODAY TO REMAIN AT LEAST
10 DEGREES BELOW NORMALS...GIVEN THE COOL DAMP AIRMASS IN PLACE AND
THE PERSISTENT CLOUDS AND SHOWERS.
UPPER LOW WILL CONTINUE TO BODILY MOVE EASTWARD ACROSS THE STATE
SUNDAY...LEADING TO A DRYING TREND FROM THE WEST...WITH PRECIP
CHANCES LOWERING TO SLIGHT CHANCES BY AFTERNOON FROM THE GREATER
PHOENIX AREA WESTWARD. MAY SEE AN ISOLATED AFTERNOON THUNDERSTORM
SUNDAY ACROSS THE CENTRAL DESERTS AS THE COLD POOL ALOFT SHIFTS
OVERHEAD. OF COURSE...WITH THE THE MAIN LOW MOVING DIRECTLY
OVERHEAD...TEMPS SUNDAY WILL STAY VERY COOL WITH MOST DESERT LOCALES
STRUGGLING TO REACH INTO THE LOW TO MID 60S.
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE WEST MONDAY INTO THE
MIDDLE OF NEXT WEEK FOR DRY CONDITIONS AND A WARMING TREND. EXPECT
HIGHS TO CLIMB GRADUALLY...REACHING SEASONAL NORMALS BY TUESDAY
UNDER MOSTLY SUNNY OR SUNNY SKIES.
VARIOUS EXTENDED RANGE MODELS...SUCH AS GFS...ECMWF AND
CANADIAN...AS WELL AS THEIR ENSEMBLES...ALL SUGGEST THAT ANOTHER
PACIFIC LOW PRESSURE SYSTEM MAY IMPACT THE DESERT SOUTHWEST LATER
NEXT WEEK. HOWEVER...ENSEMBLE MEMBER SPREADS ARE EXTREME AND THERE
IS LITTLE RUN TO RUN CONSISTENCY WITH THESE MODELS AND LITTLE MODEL
TO MODEL CONSISTENCY. LATEST GFS MOVES A SIGNIFICANT LOW INTO
ARIZONA BY NEXT FRIDAY...WHILE THE ECMWF CLOSES OFF THE LOW AND
SHIFTS IT WELL OFF THE CA COAST AT THAT TIME. GIVEN MODEL
UNCERTAINTIES...LEFT SOME MODEST POPS ACROSS THE CWA THURSDAY INTO
FRIDAY...MAINLY OVER THE WESTERN DESERTS. POPS ARE NEAR OR A BIT
ABOVE CLIMO. SHOULD THE LATEST EUROPEAN GUIDANCE BE SPOT ON...WE
WILL NOT SEE ANY PRECIP THRU AT LEAST FRIDAY...BUT IT HAS SHOWN
SIGNIFICANT DEVIATIONS RUN TO RUN SO ITS CURRENT SOLUTION CANNOT BE
TRUSTED.
&&
.AVIATION...
SOUTH-CENTRAL AZ...INCLUDING KPHX...KIWA...AND KSDL...
RAIN SHOWER ACTIVITY HAS GRADUALLY DIMINISHED IN AREAL COVERAGE
OVERNIGHT WHILE ALSO TRANSITIONING EAST OF THE PHX METRO. LIGHT
SHOWERS WILL CONTINUE TO STREAM FROM SOUTH TO NORTH GNLY THROUGH
23/1800Z WARRANTING -SHRA MENTION. EARLY MORNING CIGS HAVE THE
POTENTIAL TO BOUNCE BETWEEN VFR AND MVFR LEVELS. CONFIDENCE IS
MODERATE OF CIGS BREAKING OUT IN TO THE 5-6KFT RANGE BY MIDDAY.
SHOWERS WILL BECOME MORE VICINITY IN NATURE BY EVENING AS THEY
TRANSITION FURTHER TO THE EAST. EXPECT PERIODIC TERRAIN OBSCURATIONS
FROM CLOUDS POSSIBLE INTO THE OVERNIGHT HOURS. WINDS WILL GENERALLY
HOLD EAST HEADINGS WITH 8 TO 12 KNOTS OF SPEED POSSIBLE.
SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
WIDELY SCATTERED LIGHT SHOWER ACTIVITY WILL PERSIST ACROSS SE
CALIFORNIA THROUGH THIS EVENING...PARTICULARLY AT KBLH WHERE MVFR
CIGS/VSBY IMPACTS ARE EXPECTED THROUGH MID MORNING. UPPER LOW
PRESSURE RESPONSIBLE FOR GENERATING THE PRECIP ACTIVITY WILL BEGIN
TO MOVE FURTHER INLAND OVER SOUTHEAST CALIFORNIA...INTRODUCING
COOLER TEMPERATURES ALOFT AND THE POTENTIAL FOR ISOLATED THUNDER
DEVELOPMENT DURING THE AFTERNOON HOURS. CONFIDENCE IS LOW TO
MODERATE FOR ORGANIZED ACTIVITY NEAR THE TERMINALS...SO LEFT ANY
VCTS OR CB MENTION OUT OF THE 12Z TAF PACKAGE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
LOW PRESSURE WILL CONTINUE TO EXIT TO THE EAST MONDAY...LEAVING WELL
BELOW NORMAL TEMPERATURES AND A DRYING TREND IN TERMS OF
PRECIPITATION. COLDER AIR WILL LIE AGAINST THE CONTINENTAL DIVIDE
THROUGH MIDWEEK...KEEPING SURFACE GRADIENTS TIGHTENED AND MORE
PRONOUNCED EASTERLY WINDS DEVELOPING ACROSS EASTERN AND CENTRAL
ARIZONA. HIGH PRESSURE WILL BUILD ACROSS THE REGION...RESULTING IN A
WARMING TREND THROUGH MIDWEEK AND A RETURN TO NEAR NORMAL
TEMPERATURES BY TUESDAY. LATER INTO NEXT WEEK ANOTHER STORM SYSTEM
IS FORECAST TO DEVELOP OFF THE PACIFIC BRINGING WITH IT COOLER
TEMPERATURES FOR THE LATE WEEK AND POTENTIALLY ANOTHER ROUND OF
RAIN/SNOW SHOWER ACTIVITY TO THE REGION BY NEXT WEEKEND.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...CB
AVIATION...NOLTE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
311 PM MST SAT NOV 23 2013
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 311 PM MST SAT NOV 23 2013
COMPLEX PATTERN TODAY AS COLDER AIR MOVED INTO SOUTHEAST
UTAH...LOWERING THE SNOW LEVELS TO THE VALLEY FLOORS. BUT
SOUTHWEST COLORADO HAS STAYED IN THE WARM SECTOR WITH THE SNOW
LEVEL AROUND 8000 FEET. TELLURIDE AWOS OBSERVED LIGHT RAIN EARLIER
TODAY. SOUTHWEST COLORADO HAS BEEN A CHALLENGE WITH RESPECT TO
PRECIPITATION TYPE DURING THE PAST DAY OR TWO. CONFIDENCE IS
INCREASING THAT SNOW LEVELS WILL LOWER TO THE VALLEY FLOORS
(EXCEPT SOUTH OF CORTEZ) AS THE MOIST CONVEYOR BELT OVER ERN
ARIZONA SHIFTS INTO NWRN NEW MEXICO INTO EXTREME SWRN COLORADO.
MID LEVEL TEMPS IN THE CONVEYOR BELT IS COLDER AND DIABATIC COOLING
PROCESSES WILL RESULT IN RAIN CHANGING OVER TO SNOW. WITH SOUTHEAST
LOW LEVEL FLOW...THE RAP AND DOWNSCALED 5KM NAM SHOW THE QPF
BULLSEYE ALONG THE MONTEZUMA/LA PLATA COUNTY LINE AND MONTICELLO
UTAH WITH AREAS EXCEEDING 1 INCH OF PCPN DURING THE NEXT 12 HOURS.
THIS EQUATES TO A SNOW ACCUMULATION OF 6-12 INCHES OF "SIERRA
CEMENT" (HEAVY WET SNOW) FOR THE THIS AREA OVERNIGHT.
FOR EAST CENTRAL UTAH AND THE UNCOMPAHGRE/GRAND VALLEY...SOUTHEAST
FLOW WILL A WARMING EFFECT THAT ERODES THE COLDER SURFACE AIR.
THIS ELIMINATES THE CHANCE OF A REPEAT PERFORMANCE OF HEAVY SNOW
FROM CANYONLANDS NATIONAL PARK TO DEBEQUE CANYON. THE OVERRUNNING
PATTERN WILL NO LONGER EXIST AND THE AREAL EXTENT OF PRECIPITATION
WILL HAVE LESSENED. FARTHER NORTH...MOSTLY DRY ALTHOUGH SOME
DISSIPATING BANDS OF LIGHT SNOW MAY GENERATE FLURRIES OVER NE
UTAH/NW COLORADO.
SUNDAY AND SUNDAY NIGHT...THE CLOSED UPPER LOW WILL BE WEAKENING
AS IT MOVES INTO NWRN NEW MEXICO. ACTIVE WEATHER WILL STILL EXIST
BENEATH THE UPPER LOW SO ACCUMULATING SNOW CONTINUES ACROSS SW
COLORADO. BUT THE MOISTURE FIELD OVER ERN UTAH AND NORTHWEST
COLORADO WILL BE ERODING. AS THE LOW CONTINUES TO TRACK ACROSS NEW
MEXICO...LOW LEVEL FLOW BECOMES NORTHWEST THAT FAVORS THE NWRN SAN
JUANS AND THE SRN UNCOMPAHGRE PLATEAU (DALLAS DIVIDE/RIDGWAY AND
OURAY). BUT SNOW RATES WILL BE DIMINISHING AS THE UPPER LOW WILL
BE MOVING DOWNSTREAM. BY THE TIME THE UPPER LOW DOES DEPART THE
REGION LATE SUNDAY NIGHT...STORM TOTAL QPF AND SNOWFALL WILL BE
QUITE IMPRESSIVE FOR THE SRN PORTION OF THE FORECAST AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 311 PM MST SAT NOV 23 2013
THE UPPER LOW WILL HAVE TRANSLATED THE ROCKIES TO NEAR THE TEXAS
PANHANDLE BY SUNRISE ON MONDAY...THEN BE FORCED SOUTHWARD BY A
STRONG DIP IN THE NORTHERN STREAM ACROSS THE UPPER MISSISSIPPI
VALLEY. LINGERING WRAP AROUND MOISTURE WILL BE EXITING THE FAR
SOUTHERN CWA LATE BY MORNING AS THE UPPER LOW BEGINS TO BE FORCED
SOUTHWARD. THE RETREATING MOISTURE WILL BE REPLACED BY ANOTHER BATCH
OF HIGH LEVEL MOISTURE BEING TRANSPORTED IN ON THE NORTHERLY STREAM.
NAM/GFS DIFFERING A BIT WITH THE GFS SATURATING THE UPPER END OF THE
DENDRITIC LAYER NEAR 500MB. THE NAM A BIT MORE AGGRESSIVE WITH
SATURATION DOWN TO THE TOP OF THE NORTHERN DIVIDE MOUNTAINS THROUGH
A LARGER PORTION OF THE DENDRITIC LAYER. ASCENT IS WEAK WITH
OROGRAPHICS THE MAIN DRIVER IN THE NORTH FLOW SO WOULD EXPECT ANY
ACCUMULATIONS TO BE ON THE LIGHT SIDE. FOR NOW WILL KEEP JUST
SOME SMALL POPS IN PLACE THROUGH THE AFTERNOON UNTIL MODEL
AGREEMENT ALIGNS BETTER. TEMPERATURES ARE SURE TO BE AFFECTED BY
THE SNOW COVER ESPECIALLY OVER SOUTHEAST UTAH INTO SOUTHWEST
COLORADO SO UNDERCUT GUIDANCE NUMBERS IN MANY AREAS.
THERE SHOULD BE SLOW WARM-UP GOING INTO THE MID TO LATE WEEK PERIOD
THOUGH THE STRONG NORTHERN STREAM FLOW JUST OFF TO OUR NORTHEAST
WILL CONTINUE TO RE-ENFORCE THE COLD AIR ALOFT. VALLEY INVERSIONS
WITH THE SNOW PACK WILL CONTINUE TO PUT A DAMPER ON WARMING SO AGAIN
TEMPERATURES FROM BLENDED MODELS WERE LOWERED. A WEAK WAVE PASSAGE
ON THURSDAY MAY BRING A BIT A PASSING HIGH CLOUDINESS BUT IS NOT
LIKELY TO ADD MUCH TO MIXING. OUT WEST THE EASTERN PACIFIC TROF WILL
BE SPLITTING WITH ONE BATCH CATCHING THE WESTERLIES ACROSS THE
NORTHERN CONUS BORDER. THE OTHER MAIN BATCH WILL CLOSE OFF ANOTHER
LOW ALONG THE CALIFORNIA COASTLINE. SOME OF THIS SOUTHERN ENERGY
SHEARS OUT OF THE LOW AND PROGRESSES ACROSS THE CENTRAL ROCKIES
PULLING MOISTURE WITH IT. FOR NOW IT SEEMS THIS WILL BE MAINLY IN
THE FORM OF HIGH CLOUDINESS THROUGH THE LATE WEEK PERIOD. SO FOR NOW
A MAINLY DRY FORECAST LOOKS ON TRACK FOR HOLIDAY TRAVEL WITH
TEMPERATURES GRADUALLY WARMING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 311 PM MST SAT NOV 23 2013
ANOTHER BATCH OF ENERGY AND MOISTURE IS LIFTING ACROSS SOUTHWEST
COLORADO AND FAR EASTERN UTAH THIS AFTERNOON...BUT IS MIXING IN
WITH A BIT OF DRIER AIR ALOFT. THIS IS LEAVING A MORE SHOWERY FEEL
TO PRECIPITATION WITH VFR CONDITIONS OVER MANY OF THE FORECAST
TERMINALS LATE THIS AFTERNOON. THE STRONGER MOISTURE IS JUST TO
THE WEST OF THE 4 CORNERS AND IS AIDING IN SNOW AND LOW CLOUDINESS
OVER THE KCNY TERMINAL. MOIST UPSLOPE FLOW IS ALSO KEEPING MVFR
CIGS PUSHED UP AGAINST THE SOUTHERN SAN JUANS AND THE KDRO
TERMINAL. THE WESTERN MOISTURE PLUME WILL BE SPREADING EASTWARD
OVERNIGHT AND EXPECT DETERIORATING FLIGHT CONDITIONS OVER MANY OF
THE TAF SITES OVERNIGHT WITH THE BIGGEST IMPACTS OVER KDRO...KTEX
CLOSER TO THE CORE OF THE PASSING STORM SYSTEM TO THE SOUTH.
MOUNTAIN OBSCURATION WILL BE PROMINENT OVER MANY AREAS THROUGH
SUNDAY NIGHT BEFORE SOME DRYING BEGINS TO PUSH IN FROM THE NORTH.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 3 AM MST MONDAY FOR COZ018-019.
WINTER WEATHER ADVISORY UNTIL NOON MST SUNDAY FOR COZ021.
WINTER STORM WARNING UNTIL NOON MST SUNDAY FOR COZ022-023.
UT...WINTER STORM WARNING UNTIL 3 AM MST MONDAY FOR UTZ028.
WINTER WEATHER ADVISORY UNTIL NOON MST SUNDAY FOR UTZ029.
&&
$$
SHORT TERM...PF
LONG TERM...15
AVIATION...15
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
943 AM MST SAT NOV 23 2013
.UPDATE...
ISSUED AT 852 AM MST SAT NOV 23 2013
COMPLEX SCENARIO THIS MORNING AND PRECIPITATION TYPE IS DETERMINED
BY THE POSITIONING OF SHALLOW COLD FRONT. HEAVY WET SNOW HAS
TAPERED OFF OVER EAST CENTRAL UTAH INTO WEST CENTRAL COLORADO. BUT
THE COLDER AIR NEVER REACHED THE SRN VALLEYS WITH RAIN AT DURANGO
AND MIXED RAIN/SNOW AT PAGOSA SPRINGS. ELECTED TO CANCEL THE
WEATHER WEATHER ADVISORY OR WINTER STORM WARNING FOR THE SRN
VALLEYS. HEAVY SNOW IS STILL POSSIBLE FOR THE SWRN COLORADO
VALLEYS...BUT NOT DURING THE NEXT SEVERAL HOURS.
PROMINENT CLOSED UPPER LOW OVER SRN CALIFORNIA WILL CONTINUE TO
SEND MOISTURE ACROSS THE REGION THROUGH SUNDAY. MOIST CONVEYOR
BELT IS NOTED OVER ARIZONA INTO SRN UTAH AND THIS ACTIVITY WILL
SLOWLY SHIFT EAST. PRECIPITATION TYPE REMAINS A CHALLENGE AND WILL
NEED TO MAKE AN ASSESSMENT...BUT ANY SNOW THAT FALLS WILL BE
CLOSER ALIGNED AS "SIERRA CEMENT" RATHER THAN THE TYPICAL POWDERY
FLUFF THAT WESTERN COLORADO TYPICALLY RECEIVES. FOR THE I70
CORRIDOR WHERE HEAVY WET SNOW FELL...CURRENT GUIDANCE SUGGEST THAT
THE COLDER SURFACE TEMPS WILL MODERATE AND THAT SNOW WILL CHANGE
OVER TO RAIN. NOT FULLY CONFIDENT WITH THIS SOLUTION BUT SEEMS
REASONABLE IF DEW POINTS CLIMB INTO THE MID 30S. LOTS OF FORECAST
QUESTIONS TODAY AS THIS WINTER STORM CONTINUES TO EVOLVE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 438 AM MST SAT NOV 23 2013
UPPER LEVEL LOW CONTINUES TO PUMP MOISTURE INTO OUR REGION...OVERRUNNING
COLD AIR AT THE SURFACE AND PRODUCING HEAVY WET SNOW. EXPECTING
TEMPS TO STAY SOMEWHAT HINDERED TODAY...AS CLOUD COVER WITH
INTERMITTENT BANDS OF SNOW CONTINUES AND NOW A COLD SNOW-COVERED
SURFACE IS PRESENT IN MANY AREAS. MANY NORMALLY ARID AREAS
RECEIVED NOTABLE AMOUNTS OF SNOW OVERNIGHT INCLUDING OVER 5 INCHES
JUST SOUTH OF MOAB AND OVER 3 INCHES AT GRAND JUNCTION AS OF
MIDNIGHT WITH LIGHT TO MODERATE SNOW CONTINUING SINCE. THAT BEING
SAID...SNOW LEVELS IN THE SOUTHERN CWA HAVE NOT REACHED VALLEY
FLOORS...KEEPING BOTH CORTEZ AND DURANGO IN RAIN INSTEAD OF
CHANGING OVER TO SNOW. NOT EXPECTING THIS TO CHANGE
TODAY...ESPECIALLY WITH WARM AIR CONTINUING TO PUMP UP INTO THE
REGION AT MID LEVELS.
CURRENT RADAR SHOWS BAND OF MODERATE SNOW FROM MOAB NORTHEAST TO
EAGLE. TRICKY ADVISORY/WARNING EVENTS THIS WEEKEND...AS SNOW IS
COMING IN WAVES. KEPT ADVISORIES OUT FOR THE GRAND VALLEY AND I-70
CORRIDOR TO EDWARDS UNTIL 11AM AS THE SNOW CONTINUES TO COME DOWN
IN LIGHT TO MODERATE RATES. CAN ALREADY SEE MORE LIGHT ECHOES
ON RADAR MOVING INTO THE NORTHERN SAN JUANS MTNS. FAVORING A
BLEND OF THE RAP AND NAM12 IN THE SHORT TERM AS THE RAP IS
IDENTIFYING SMALLER SCALE FEATURES BUT THE NAM IS BETTER ON
TIMING. THAT BEING SAID...THE BEST CHANCE OF SNOWFALL BY LATE
MORNING TODAY WILL BE DOWN IN THE FOUR CORNERS AREA. THIS
PRECIPITATION WILL GRADUALLY MOVE NORTHEAST THROUGHOUT THE
AFTERNOON AND IS EXPECTED TO REACH THE GRAND VALLEY AND I-70
CORRIDOR AGAIN BY THIS EVENING. DECIDED TO NOT PUT OUT ANY NEW
ADVISORIES AT THIS POINT SINCE SNOWFALL AMTS LOOK TO BE LESS THAN
THIS ONGOING FRI NIGHT/SAT MORNING EVENT...BUT DEFINITELY
SOMETHING THAT WE WILL BE KEEPING AN EYE ON. THE UPPER LEVEL JET
MOVES EAST TONIGHT...WHICH WILL BE ONE LESS FACTOR TO HELP
SMPLIFY THE SNOWFALL RATES TODAY. DYNAMICAL LIFTING AHEAD OF THE
LOW PRESSURE REMAINS DECENT FOR CONTINUATION OF SNOW PRODUCTION
THROUGH A WELL-SATURATED ENVIRONMENT.
THE FUN CONTINUES THROUGH SUNDAY AS THE UPPER LEVEL LOW FINALLY
ACCELERATES EAST OVER THE FOUR CORNERS BY SUNDAY EVENING. AS THE
LOW PROCEEDS EAST... WRAPAROUND MOISTURE AIDED BY DISTURBANCES
WITHIN THE SYSTEM WILL CONTINUE UNTIL THE ENTIRETY IS OUT OF THE
REGION FOR THE EARLY WORKWEEK.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 438 AM MST SAT NOV 23 2013
SHOULD NOTICE A DIMINISH IN PRECIPITATION BY SUNDAY NIGHT IN ALL
AREAS BUT THE CENTRAL TO EASTERN SAN JUAN MTNS UP INTO THE
GUNNISON VALLEY WHICH WILL LIKELY CONTINUE THROUGH MONDAY MORNING.
MONDAY THROUGH FRIDAY...ON MONDAY THE LOW CENTER WILL HAVE MOVED
TO NE NM AND INTO THE TX/OK PANHANDLES. NORTH TO NORTHEAST FLOW
ALOFT WILL SPREAD ACROSS THE AREA AND PCPN WILL BE CONFINED TO THE
CO SW MTS AND THE CONTINENTAL DIVIDE IN THE NORTHERN AND CENTRAL
CO MTS. CLEARING SKIES AND DRYING CONDITIONS WILL SPREAD EAST FROM
EASTERN UT. A SHARP RIDGE WILL BUILD OVER THE GREAT BASIN MON NIGHT
AND MOVE EAST...WITH THE UPPER RIDGELINE PASSING OVER EASTERN UT
AND WESTERN CO ON WED. THURSDAY AND FRIDAY THE PATTERN TRANSITIONS
FROM THE DOMINANT RIDGE OVER THE WEST TO THE NEXT BIG PACIFIC
TROUGH...WHICH THE MIDRANGE MODELS MOVE ONSHORE OVER NORTHERN
CALIFORNIA ON FRIDAY. SW WINDS ALOFT WILL INCREASE OVER THE
FORECAST AREA FRIDAY WITH INCREASING CLOUDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 943 AM MST SAT NOV 23 2013
ANOTHER BATCH OF MOISTURE IS MOVING NORTHWARD ACROSS THE SOUTHERN
UTAH AND COLORADO LINE. MIXED PRECIPITATION IS POSSIBLE IN THIS
BAND WHICH LOOK TO AFFECT THE KCNY AND KGJT TERMINALS THROUGH THE
EARLY PORTION OF THE FORECAST. STRATUS AND LOW CLOUDS ARE
CURRENTLY AFFECTING THE KASE AND KMTJ TERMINALS. EXPECT SOME
IMPROVEMENT FROM THESE SITES THROUGH EARLY AFTERNOON...THOUGH
PASSING SHOWERS NEAR KMTJ MAY TEMPORARILY KEEP LOWERED FLIGHT
CRITERIA IN PLACE. UNSETTLED CONDITIONS WILL REMAIN OVER THE
REGION THROUGH THE NEXT 24 HOURS. MOUNTAIN OBSCURATIONS AND
LOWERED FLIGHT CRITERIA REMAIN IN THE PICTURE THROUGH AT LEAST
MONDAY AFTERNOON.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR COZ018-019.
UT...WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR UTZ028.
WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR UTZ029.
&&
$$
UPDATE...PF
SHORT TERM...JAM
LONG TERM...JAM/CC
AVIATION...15
AREA FORECAST DISCUSSION
NWS ALBANY NY
1242 PM EST SAT NOV 23 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL PLUNGE SOUTH THROUGH THE REGION THIS
AFTERNOON...AND TRIGGER LAKE EFFECT SNOW DOWNWIND OF THE EASTERN
GREAT LAKES...WITH SNOW SHOWERS AND SQUALLS IN MANY OTHER PARTS
OF THE REGION. HIGH PRESSURE WILL BUILD EAST FROM THE GREAT
PLAINS TONIGHT AND SLIDE OFFSHORE BY MONDAY...BRINGING WINDY AND
WINTER LIKE VERY COLD CONDITIONS. LATE MONDAY A WARM FRONT WILL
PUSH THROUGH THE REGION. ANOTHER WEAK COLD FRONT WILL FOLLOW ON
TUESDAY...AS A STORM EJECTS NORTHWARD ALONG THE ATLANTIC SEABOARD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENT OBSERVATIONS AND TRENDS ARE CONSISTENT WITH CURRENT
FORECAST. SO...PREVIOUS DISCUSSION STILL DESCRIBES THE FACTORS IN
THE FORECAST THROUGH THIS AFTERNOON.
PREV AFD BELOW...
THE ENTIRE AREA IS STILL PRECIP- FREE LATE THIS MORNING...AS
SHORT- WAVE RIDGING STILL IN CONTROL. HOWEVER...LAKE ENHANCED SNOW
STARTING TO DEVELOP ACROSS THE EASTERN LAKE ONTARIO COUNTIES AND
THE TUG HILL AHEAD OF AN ARCTIC BOUNDARY...WHICH IS ALLOWING
WESTERLY FLOW TO ALIGN WITH FURTHER COOLING ALOFT. HIGH RES MODELS
SUCH AS THE HRRR AND LOCAL WRF INDICATE BANDS OF LAKE ENHANCED
SNOW SHOWERS AND SQUALLS WILL DEVELOP EARLY THIS AFTERNOON ACROSS
THE WESTERN ADIRONDACKS...AND PUSH SOUTH AND EAST ALONG THE ARCTIC
FRONT LATER THIS AFTERNOON INTO THE EARLY EVENING. BEST
ACCUMULATIONS STILL LOOK TO BE ACROSS HERKIMER COUNTY...WHERE MORE
LAKE MOISTURE AND UPSLOPE COMPONENT WILL ENHANCE
SNOWFALL...ALTHOUGH A QUICK INCH OR TWO OF ACCUMULATION WILL BE
POSSIBLE ESPECIALLY FROM THE MOHAWK VALLEY NORTHWARD INTO THE
ADIRONDACKS. SCATTERED SNOW SHOWERS AND EVEN A FEW SQUALLS MAY
MAKE IT INTO THE CAPITAL REGION AND EASTERN CATSKILLS AROUND 4-6
PM. RAISED POPS IN THESE AREAS TO ACCOUNT FOR THIS POSSIBLE
ACTIVITY ALONG THE ARCTIC BOUNDARY.
AS THE ARCTIC FRONT MOVES THROUGH THE FLOW BEHIND IT WILL QUICKLY
TURN TO A 310 TO 320 ORIENTATION SO THE LAKE ENHANCED SNOW SHOWERS
AND SQUALLS WILL NOT LAST THAT LONG OVER NORTHERN HERKIMER COUNTY
AND HAVE LIMITED THE ACCUMULATIONS TO 3 TO 6 INCHES THROUGH THIS
EVENING. SNOW SQUALLS WILL LIKELY AFFECT AT LEAST PARTS OF THE
MOHAWK AND SCHOHARIE VALLEYS...AND THE EASTERN CATSKILLS AFTER THE
FLOW BECOMES 310 TO 320 DEGREES...BUT THIS IS NOT LIKELY TO OCCUR
UNTIL THIS EVENING.
TEMPS WILL NOT RISE VERY MUCH FROM THE MORNING LOWS DUE TO THE COLD
ADVECTION THAT WILL BE OCCURRING. HIGHS TODAY WILL BE BETWEEN THE
UPPER 20S AND 40 FOR MOST OF THE FORECAST AREA...WITH LOW OR MID 40S
OVER THE MID HUDSON VALLEY AND NORTHWEST CT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
ITS WINTER...FOR REAL AS TEMPS WILL RUN 10-20F BLO NORMALS NEXT
FEW DAYS. GUID SUITE GFS/NAM/GEM IN FAIRLY GOOD AGREEMENT DURING
MOST OF THIS PERIOD. 500HPA TROF AXIS SWINGS THROUGH REGION THIS
EVNG...ARCTIC CDFNT SURGES SOUTH THROUGH REST OF RGN...AND FRIGID
AIR FOR NOV POURS IN. CDFNT WILL TRIGGER SNOW SQUALLS AND -SHSN WITH
ITS PASSAGE THIS EVENING...THEN EVENT EVOLVES INTO LK EFFECT/NW-N
FLOW TRRN EVENT. LK EFFECT FOCUS QUICKLY SHIFTS W OF FCA BASED ON
NAM/LOCAL WRF DURING LATE EVNG HOURS. REST OF NIGHT UPSLOPE -SHSN
OVER GREENS...ADIRONDACKS AND CATSKILLS. BY SUNDAY CAP SETS UP OVER
LK ONT AT 4KFT BASED ON BUFKIT. THIS SHOULD DIMINISH ANY LK
EFFECT...AND FLOW IS SUCH IT WILL BE WEST OF FCA...AND NOT PENETRATE
VERY FAR INLAND WITHOUT HELP FROM TRRN OR OTHER LAKES.
WIND GRADIENT BECOMES VERY STRONG AT 12-14 MB ACRS NYS TNGT AND
SUN. BY SUNDAY MORNING FLOW IS PARALLEL UP TO 500 HPA. STRONG WINDS
WILL BUFFET THE REGION WITH NAM/GFS BDNRY LAYER WINDS 25-35
KTS...AND MET/MAV GUID WINDS 15-25MPH. WIND ADVISORIES MAY NEED TO
BE CONSIDERED FOR TNGT AND SUN. AWAY FM E GRTLKS SKIES WILL BCM PS
SUNDAY...BUT ANY SUN WILL HARDLY BE NOTICEABLE.
WINDS COMBINED WITH TEMPS IN SINGLE DIGITS TO TEENS...ONLY RISING
TO TEENS TO MID 20S SUNDAY WILL RESULT IN WIND CHILLS JUST ABV
ADVISORY VALUES. IT WILL BE QUITE A MAJOR CHANGE FM PAST FEW
WEEKS.
SUN NT THE MAIN 500HPA TROF AXIS SHIFTS EAST OF FCA AND LARGE SFC
HIGH SLIDES FM OH VLY TO DELMARVA WITH RIDGE N INTO QB. WINDS
WILL GRADUALLY DIMINISH AS RIDGE CRESTS OVR RGN BY DAYBREAK. WITH
CLEAR SKIES...SNOW COVER IN MANY PLACES N & W OF ALB...LONG NIGHT
AND WINDS BCMG LT AND VRBL...TEMPS WILL PLUNGE TO SINGLE DIGITS
TO TEENS WITH LOWS BELOW ZERO IN SOME PARTS OF ADIRONDACKS.
MONDAY SFC HIGH SLIDES OFFSHORE AND WMFNT PUSHES THRU RGN. MOST
OF THE GUID BRINGS INCRG CLOUDS...BUT LITTLE QPF. GIVEN THE
MAGNITUDE OF THE CD AIR THAT`S HERE...AND RESIDUAL LK
EFFECT...WILL CONSIDER KEEPING CHC -SHSN. MON NT A WK CDFNT AND
500HPA TROF PASS ACROSS RGN. THE GFS/GEM TRIGGERS ANOTHER ROUND OF
SCT -SHSN...AGAIN MAINLY N & W WHERE SOME LK ENHANCEMENT WILL
ASSIST....THE NAM MAINLY DRY.
BY TUES ALL GUID HAS A CDFNT DROPPING SE INTO THE GRTLKS AS 500HPA
CUTOFF DIGS INTO GRTLKS. MDLS BY TUES HAVE SOME SPREAD...BUT WERE
CONVERGING ON A SOLUTION....EVEN THOUGH THEY HAVE MADE A
SIGNIFICANT SHIFT FM MOST OF FRI GUID. GEM/ECMWF/HPC WEAKLY PHASE
THE N AND S STREAM 500HPA TROFS OVER THE EAST ON TUES...WITH EAST
COASTAL STORM DEEPENING AND MOVING NE THROUGH GA/CAROLINA PIEDMONT
BEFORE MOVING JUST OFFSHORE AND NORTHWARD TO LONG ISLAND NY.
OPERATIONAL GFS TAKES THIS SYSTEM OUT TO SEA LARGELY S OF FCA..AND
IS NOW AN OUTLIER...EVEN TO ITS OWN ENSEMBLE...WHICH IS COALESCING
AROUND A FEW CAMPS...QPF OF EITHER 0.1...1.0 AND 1.5 INCHES LIQ.
MOST MEMBERS START WITH AND INCH OR TWO OF SNOW CHANGE MOSTLY TO
RAIN. 4 OR 5 ARE STILL MOSTLY SNOW...BUT ONLY ONE OF THE 1.0 QPF
MEMBERS IS ALL SNOW. MOST HAVE A QPF OF 1-1.5 INCHES LIQ.
LATE TUES MIX PCPN WILL OVERSPREAD RGN FM S TO N...CHANGING
QUICKLY TO RAIN.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
COASTAL STORM IS OFF NJ COAST WED MORNING....500HPA TROF SWINGS
OFFSHORE...AS DOES STORM...WITH PCPN ENDING FM W TO E DURING THE
MORNING. ANOTHER ARCTIC HIGH BUILDS TWRD RGN FM ONT/QB WED NT INTO
THANKSGIVING. WINDS WILL BE BRISK AGAIN DURING THIS PERIOD AND
TEMPS WELL BLO NORMAL. WITH N-NW FLOW LK RESPONSE WILL BE LIMITED
AND WELL WEST OF AREA. SOME SCT UPSLOPE -SHSN WILL BE AROUND.
THE WEEK WILL END WITH LARGE SFC HIGH PRESSURE OVER EASTERN PARTS
OF NATION...BUT SIGNIFICANT 500HPA TROF OVER NE AND E GRTLKS. THIS
TROF WILL LIKELY ENHANCE LK EFFECT RESPONSE...MAINLY W OF
FCA...BUT SOME -SHSN OVER W REACHES OF FCA. MOST OF REGN WILL BE
COLD AND DRY. TEMPS WILL BE WELL BLO NORMAL AND MORE TYPICAL OF
JANUARY. WILL POPULATE WITH HPC MIDNIGHT GRIDS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AN ARCTIC COLD FRONT WILL APPROACH FROM THE THE NORTHWEST THIS
AFTERNOON...CROSSING THE TERMINALS BETWEEN AROUND 21Z AND 00Z.
SCATTERED SNOW SHOWERS AND EVEN A FEW SNOW SQUALLS ARE POSSIBLE
ASSOCIATED WITH THE PASSAGE OF THE FRONT. WILL MENTION A TEMPO
GROUP AT KALB/KPSF/KGFL TO ACCOUNT FOR THE SNOW SHOWERS...BUT WILL
ONLY EXPLICITLY MENTION MVFR CONDITIONS FOR NOW SINCE ANY IFR/LIFR
EXPECTED TO BE BRIEF. LESS OF A CHANCE OF MEASURABLE SNOW AT
KPOU...SO ONLY MENTIONED VCSH THERE. A FEW ADDITIONAL SNOW SHOWERS
ARE POSSIBLE BEHIND THE FRONT TONIGHT...BEFORE SHIFTING WELL SOUTH
AND WEST OF THE AREA BY SUNDAY MORNING. MAINLY VFR CONDITIONS ARE
EXPECTED EXPECT IN SNOW SHOWERS.
GUSTY NORTHWEST WINDS WILL BE ANOTHER CONCERN THROUGH THE
PERIOD...WITH SUSTAINED SPEEDS AROUND 12-19 KT WITH GUSTS OF 25 TO
NEAR 35 KT POSSIBLE...ESPECIALLY ON SUNDAY.
OUTLOOK...
SUNDAY: MODERATE OPERATIONAL IMPACT. WINDY.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT.BREEZY NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
TUESDAY NIGHT: HIGH OPERATIONAL IMPACT. RA/SN LIKELY.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS.
A SERIES OF COLD FRONTS WILL BRING LIGHT PRECIPITATION TO THE AREA
OVER THE WEEKEND. HEAVIEST LIQUID EQUIVALENT PRECIPITATION WILL BE
OVER THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY WHERE 0.10
TO 0.33 INCHES MAY FALL...MAINLY AS SNOW. LITTLE RIVER RESPONSE IS
EXPECTED. MAINLY DRY AND WEATHER IS EXPECTED FOR MONDAY AND
TUESDAY.
THE FRIGID AIR MASS ON SUNDAY WILL ALLOW ICE TO BEGIN TO FORM ON
SHALLOWER LAKES AND RIVERS SUNDAY INTO EARLY NEXT WEEK.
TUESDAY INTO WEDNESDAY A COASTAL STORM COULD BRING 1 TO 2 INCHES
OF RAIN TO MUCH OF THE REGION...RESULTING IN SIGNIFICANT WITHIN
BANK RISES.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ032.
LAKE EFFECT SNOW ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
SUNDAY FOR NYZ038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...GJM/NAS/JPV
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...JPV
HYDROLOGY...SNYDER/NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1237 PM EST SAT NOV 23 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL PLUNGE SOUTH THROUGH THE REGION THIS
AFTERNOON...AND TRIGGER LAKE EFFECT SNOW DOWNWIND OF THE EASTERN
GREAT LAKES...WITH SNOW SHOWERS AND SQUALLS IN MANY OTHER PARTS
OF THE REGION. HIGH PRESSURE WILL BUILD EAST FROM THE GREAT
PLAINS TONIGHT AND SLIDE OFFSHORE BY MONDAY...BRINGING WINDY AND
WINTER LIKE VERY COLD CONDITIONS. LATE MONDAY A WARM FRONT WILL
PUSH THROUGH THE REGION. ANOTHER WEAK COLD FRONT WILL FOLLOW ON
TUESDAY...AS A STORM EJECTS NORTHWARD ALONG THE ATLANTIC SEABOARD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1023 AM...THE ENTIRE AREA IS STILL PRECIP-FREE LATE THIS
MORNING...AS SHORT-WAVE RIDGING STILL IN CONTROL. HOWEVER...LAKE
ENHANCED SNOW STARTING TO DEVELOP ACROSS THE EASTERN LAKE ONTARIO
COUNTIES AND THE TUG HILL AHEAD OF AN ARCTIC BOUNDARY...WHICH IS
ALLOWING WESTERLY FLOW TO ALIGN WITH FURTHER COOLING ALOFT. HIGH
RES MODELS SUCH AS THE HRRR AND LOCAL WRF INDICATE BANDS OF LAKE
ENHANCED SNOW SHOWERS AND SQUALLS WILL DEVELOP EARLY THIS
AFTERNOON ACROSS THE WESTERN ADIRONDACKS...AND PUSH SOUTH AND EAST
ALONG THE ARCTIC FRONT LATER THIS AFTERNOON INTO THE EARLY
EVENING. BEST ACCUMULATIONS STILL LOOK TO BE ACROSS HERKIMER
COUNTY...WHERE MORE LAKE MOISTURE AND UPSLOPE COMPONENT WILL
ENHANCE SNOWFALL...ALTHOUGH A QUICK INCH OR TWO OF ACCUMULATION
WILL BE POSSIBLE ESPECIALLY FROM THE MOHAWK VALLEY NORTHWARD INTO
THE ADIRONDACKS. SCATTERED SNOW SHOWERS AND EVEN A FEW SQUALLS MAY
MAKE IT INTO THE CAPITAL REGION AND EASTERN CATSKILLS AROUND 4-6
PM. RAISED POPS IN THESE AREAS TO ACCOUNT FOR THIS POSSIBLE
ACTIVITY ALONG THE ARCTIC BOUNDARY.
AS THE ARCTIC FRONT MOVES THROUGH THE FLOW BEHIND IT WILL QUICKLY
TURN TO A 310 TO 320 ORIENTATION SO THE LAKE ENHANCED SNOW SHOWERS
AND SQUALLS WILL NOT LAST THAT LONG OVER NORTHERN HERKIMER COUNTY
AND HAVE LIMITED THE ACCUMULATIONS TO 3 TO 6 INCHES THROUGH THIS
EVENING. SNOW SQUALLS WILL LIKELY AFFECT AT LEAST PARTS OF THE
MOHAWK AND SCHOHARIE VALLEYS...AND THE EASTERN CATSKILLS AFTER THE
FLOW BECOMES 310 TO 320 DEGREES...BUT THIS IS NOT LIKELY TO OCCUR
UNTIL THIS EVENING.
TEMPS WILL NOT RISE VERY MUCH FROM THE MORNING LOWS DUE TO THE COLD
ADVECTION THAT WILL BE OCCURRING. HIGHS TODAY WILL BE BETWEEN THE
UPPER 20S AND 40 FOR MOST OF THE FORECAST AREA...WITH LOW OR MID 40S
OVER THE MID HUDSON VALLEY AND NORTHWEST CT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
ITS WINTER...FOR REAL AS TEMPS WILL RUN 10-20F BLO NORMALS NEXT
FEW DAYS. GUID SUITE GFS/NAM/GEM IN FAIRLY GOOD AGREEMENT DURING
MOST OF THIS PERIOD. 500HPA TROF AXIS SWINGS THROUGH REGION THIS
EVNG...ARCTIC CDFNT SURGES SOUTH THROUGH REST OF RGN...AND FRIGID
AIR FOR NOV POURS IN. CDFNT WILL TRIGGER SNOW SQUALLS AND -SHSN WITH
ITS PASSAGE THIS EVENING...THEN EVENT EVOLVES INTO LK EFFECT/NW-N
FLOW TRRN EVENT. LK EFFECT FOCUS QUICKLY SHIFTS W OF FCA BASED ON
NAM/LOCAL WRF DURING LATE EVNG HOURS. REST OF NIGHT UPSLOPE -SHSN
OVER GREENS...ADIRONDACKS AND CATSKILLS. BY SUNDAY CAP SETS UP OVER
LK ONT AT 4KFT BASED ON BUFKIT. THIS SHOULD DIMINISH ANY LK
EFFECT...AND FLOW IS SUCH IT WILL BE WEST OF FCA...AND NOT PENETRATE
VERY FAR INLAND WITHOUT HELP FROM TRRN OR OTHER LAKES.
WIND GRADIENT BECOMES VERY STRONG AT 12-14 MB ACRS NYS TNGT AND
SUN. BY SUNDAY MORNING FLOW IS PARALLEL UP TO 500 HPA. STRONG WINDS
WILL BUFFET THE REGION WITH NAM/GFS BDNRY LAYER WINDS 25-35
KTS...AND MET/MAV GUID WINDS 15-25MPH. WIND ADVISORIES MAY NEED TO
BE CONSIDERED FOR TNGT AND SUN. AWAY FM E GRTLKS SKIES WILL BCM PS
SUNDAY...BUT ANY SUN WILL HARDLY BE NOTICEABLE.
WINDS COMBINED WITH TEMPS IN SINGLE DIGITS TO TEENS...ONLY RISING
TO TEENS TO MID 20S SUNDAY WILL RESULT IN WIND CHILLS JUST ABV
ADVISORY VALUES. IT WILL BE QUITE A MAJOR CHANGE FM PAST FEW
WEEKS.
SUN NT THE MAIN 500HPA TROF AXIS SHIFTS EAST OF FCA AND LARGE SFC
HIGH SLIDES FM OH VLY TO DELMARVA WITH RIDGE N INTO QB. WINDS
WILL GRADUALLY DIMINISH AS RIDGE CRESTS OVR RGN BY DAYBREAK. WITH
CLEAR SKIES...SNOW COVER IN MANY PLACES N & W OF ALB...LONG NIGHT
AND WINDS BCMG LT AND VRBL...TEMPS WILL PLUNGE TO SINGLE DIGITS
TO TEENS WITH LOWS BELOW ZERO IN SOME PARTS OF ADIRONDACKS.
MONDAY SFC HIGH SLIDES OFFSHORE AND WMFNT PUSHES THRU RGN. MOST
OF THE GUID BRINGS INCRG CLOUDS...BUT LITTLE QPF. GIVEN THE
MAGNITUDE OF THE CD AIR THAT`S HERE...AND RESIDUAL LK
EFFECT...WILL CONSIDER KEEPING CHC -SHSN. MON NT A WK CDFNT AND
500HPA TROF PASS ACROSS RGN. THE GFS/GEM TRIGGERS ANOTHER ROUND OF
SCT -SHSN...AGAIN MAINLY N & W WHERE SOME LK ENHANCEMENT WILL
ASSIST....THE NAM MAINLY DRY.
BY TUES ALL GUID HAS A CDFNT DROPPING SE INTO THE GRTLKS AS 500HPA
CUTOFF DIGS INTO GRTLKS. MDLS BY TUES HAVE SOME SPREAD...BUT WERE
CONVERGING ON A SOLUTION....EVEN THOUGH THEY HAVE MADE A
SIGNIFICANT SHIFT FM MOST OF FRI GUID. GEM/ECMWF/HPC WEAKLY PHASE
THE N AND S STREAM 500HPA TROFS OVER THE EAST ON TUES...WITH EAST
COASTAL STORM DEEPENING AND MOVING NE THROUGH GA/CAROLINA PIEDMONT
BEFORE MOVING JUST OFFSHORE AND NORTHWARD TO LONG ISLAND NY.
OPERATIONAL GFS TAKES THIS SYSTEM OUT TO SEA LARGELY S OF FCA..AND
IS NOW AN OUTLIER...EVEN TO ITS OWN ENSEMBLE...WHICH IS COALESCING
AROUND A FEW CAMPS...QPF OF EITHER 0.1...1.0 AND 1.5 INCHES LIQ.
MOST MEMBERS START WITH AND INCH OR TWO OF SNOW CHANGE MOSTLY TO
RAIN. 4 OR 5 ARE STILL MOSTLY SNOW...BUT ONLY ONE OF THE 1.0 QPF
MEMBERS IS ALL SNOW. MOST HAVE A QPF OF 1-1.5 INCHES LIQ.
LATE TUES MIX PCPN WILL OVERSPREAD RGN FM S TO N...CHANGING
QUICKLY TO RAIN.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
COASTAL STORM IS OFF NJ COAST WED MORNING....500HPA TROF SWINGS
OFFSHORE...AS DOES STORM...WITH PCPN ENDING FM W TO E DURING THE
MORNING. ANOTHER ARCTIC HIGH BUILDS TWRD RGN FM ONT/QB WED NT INTO
THANKSGIVING. WINDS WILL BE BRISK AGAIN DURING THIS PERIOD AND
TEMPS WELL BLO NORMAL. WITH N-NW FLOW LK RESPONSE WILL BE LIMITED
AND WELL WEST OF AREA. SOME SCT UPSLOPE -SHSN WILL BE AROUND.
THE WEEK WILL END WITH LARGE SFC HIGH PRESSURE OVER EASTERN PARTS
OF NATION...BUT SIGNIFICANT 500HPA TROF OVER NE AND E GRTLKS. THIS
TROF WILL LIKELY ENHANCE LK EFFECT RESPONSE...MAINLY W OF
FCA...BUT SOME -SHSN OVER W REACHES OF FCA. MOST OF REGN WILL BE
COLD AND DRY. TEMPS WILL BE WELL BLO NORMAL AND MORE TYPICAL OF
JANUARY. WILL POPULATE WITH HPC MIDNIGHT GRIDS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AN ARCTIC COLD FRONT WILL APPROACH FROM THE THE NORTHWEST THIS
AFTERNOON...CROSSING THE TERMINALS BETWEEN AROUND 21Z AND 00Z.
SCATTERED SNOW SHOWERS AND EVEN A FEW SNOW SQUALLS ARE POSSIBLE
ASSOCIATED WITH THE PASSAGE OF THE FRONT. WILL MENTION A TEMPO
GROUP AT KALB/KPSF/KGFL TO ACCOUNT FOR THE SNOW SHOWERS...BUT WILL
ONLY EXPLICITLY MENTION MVFR CONDITIONS FOR NOW SINCE ANY IFR/LIFR
EXPECTED TO BE BRIEF. LESS OF A CHANCE OF MEASURABLE SNOW AT
KPOU...SO ONLY MENTIONED VCSH THERE. A FEW ADDITIONAL SNOW SHOWERS
ARE POSSIBLE BEHIND THE FRONT TONIGHT...BEFORE SHIFTING WELL SOUTH
AND WEST OF THE AREA BY SUNDAY MORNING. MAINLY VFR CONDITIONS ARE
EXPECTED EXPECT IN SNOW SHOWERS.
GUSTY NORTHWEST WINDS WILL BE ANOTHER CONCERN THROUGH THE
PERIOD...WITH SUSTAINED SPEEDS AROUND 12-19 KT WITH GUSTS OF 25 TO
NEAR 35 KT POSSIBLE...ESPECIALLY ON SUNDAY.
OUTLOOK...
SUNDAY: MODERATE OPERATIONAL IMPACT. WINDY.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT.BREEZY NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
TUESDAY NIGHT: HIGH OPERATIONAL IMPACT. RA/SN LIKELY.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS.
A SERIES OF COLD FRONTS WILL BRING LIGHT PRECIPITATION TO THE AREA
OVER THE WEEKEND. HEAVIEST LIQUID EQUIVALENT PRECIPITATION WILL BE
OVER THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY WHERE 0.10
TO 0.33 INCHES MAY FALL...MAINLY AS SNOW. LITTLE RIVER RESPONSE IS
EXPECTED. MAINLY DRY AND WEATHER IS EXPECTED FOR MONDAY AND
TUESDAY.
THE FRIGID AIR MASS ON SUNDAY WILL ALLOW ICE TO BEGIN TO FORM ON
SHALLOWER LAKES AND RIVERS SUNDAY INTO EARLY NEXT WEEK.
TUESDAY INTO WEDNESDAY A COASTAL STORM COULD BRING 1 TO 2 INCHES
OF RAIN TO MUCH OF THE REGION...RESULTING IN SIGNIFICANT WITHIN
BANK RISES.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ032.
LAKE EFFECT SNOW ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
SUNDAY FOR NYZ038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...GJM/JPV
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...JPV
HYDROLOGY...SNYDER/NAS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
407 PM CST SAT NOV 23 2013
.DISCUSSION...
145 PM CST
MAIN FORECAST CONCERNS CONTINUE TO BE COLD TEMPERATURES AND SOME
LIGHT LAKE EFFECT SNOW OVER MAINLY PORTER COUNTY TONIGHT INTO
SUNDAY...THEN THE POTENTIAL FOR SOME LIGHT SNOW AREA-WIDE ON MONDAY
WITH A DIGGING UPPER DISTURBANCE. COLDER THAN NORMAL WEATHER LOOKS
TO CONTINUE THROUGH THE PERIOD...THOUGH NO SUBSTANTIAL ORGANIZED
PRECIP PRODUCERS ARE NOTED IN MODEL GUIDANCE THROUGH NEXT WEEKEND.
STRONG 1048 MB HIGH PRESSURE WAS BUILDING SOUTHEAST ACROSS THE
NORTHERN PLAINS AND UPPER MIDWEST THIS AFTERNOON IN ASSOCIATION WITH
A SOLID PUSH OF COLD/DRY ARCTIC AIR. AIR TEMPS IN THE TEENS TO MID
20S AND SURFACE DEW POINTS IN THE LOWER SINGLE DIGITS CHARACTERIZE
THIS AIR MASS...POINTING TO A COLD NIGHT TONIGHT ACROSS THE FORECAST
AREA AS CLEARING SKIES AND DECREASING WINDS MAKE FOR FAVORABLE
COOLING CONDITIONS. OVERNIGHT LOWS ARE EXPECTED TO RANGE FROM THE
SINGLE DIGITS TO MID TEENS...WITH THE COOLEST READINGS ACROSS NORTH
CENTRAL IL WEST OF CHICAGO WHERE WINDS WILL DIMINISH MORE
SUBSTANTIALLY AND AWAY FROM URBAN WARMTH AND LAKE-INDUCED CLOUDS
DOWNWIND OF LAKE MICHIGAN INTO INDIANA. SOME LIGHT LAKE EFFECT SNOW
SHOWERS WERE IMPINGING UPON PARTS OF NORTHWEST AND NORTH CENTRAL
INDIANA INCLUDING PORTER COUNTY THIS AFTERNOON...AND THIS IS
EXPECTED TO CONTINUE TONIGHT WITH NEARLY UNIDIRECTIONAL WINDS FROM
ABOUT 330 DEGREES THROUGH THE DEEP LAKE-INDUCED MIXED LAYER. WINDS
WILL BACK MORE WESTERLY DURING THE DAY SUNDAY...PUSHING ANY
LINGERING LAKE EFFECT FLURRIES OR LIGHT SNOW SHOWERS EAST OF THE
CWA. WHILE COLD AIR ALOFT (-18 C AT 850 HPA) WILL CONTINUE TO
PRODUCE LARGE LAKE-INDUCED DELTA T/S IN EXCESS OF 20 DEG AND DEEP
EQUILIBRIUM LEVELS ABOVE 10 KFT...LACK OF MOISTURE AND MULTI-BAND
ORGANIZATION WILL KEEP SNOW SHOWERS ON THE LIGHT SIDE IN PORTER
COUNTY. SOME MINOR ACCUMULATIONS LESS THAN AN INCH IS POSSIBLE IN
EXTREME NORTHEAST PORTER COUNTY TONIGHT BEFORE BANDS MOVE EAST OF
AREA SUNDAY. COLD START TO TEMPS SUNDAY AND SURFACE RIDGE MOVING
ACROSS THE AREA EXPECTED TO LIMIT TEMPS TO MID-20S MOST AREAS AGAIN
DESPITE AMPLE SUNSHINE.
THE NEXT IN A SERIES OF NORTHWEST FLOW UPPER TROUGHS IS PROGGED TO
DIG ACROSS THE UPPER MIDWEST SUNDAY/MONDAY. GUIDANCE INDICATES THE
MAIN DEEP LAYER FORCING WILL PASS LARGELY NORTH OF THE CWA MONDAY...
THOUGH 30-40 KT SOUTHWEST 850 HPA FLOW IS EXPECTED TO PRODUCE
SUFFICIENT WARM/MOIST ADVECTION AND ISENTROPIC ASCENT TO GENERATE
LIGHT SNOW ACROSS THE FORECAST AREA DURING THE DAY. SNOWFALL AMOUNTS
TO PERHAPS AN INCH OR SO APPEAR POSSIBLE AT THIS TIME...WITH THE
GREATEST AMOUNTS GENERALLY NORTH OF I-80 BASED ON QPF PLACEMENT
CLOSER TO THE BETTER DEEP LAYER FORCING TO OUR NORTH. A SECOND VORT
DIGS INTO THE TROUGH LATE MONDAY NIGHT/TUESDAY WHICH SLOWS EASTWARD
PROGRESSION OF THE UPPER TROUGH ACROSS THE REGION AND MAY PRODUCE
SOME ADDITIONAL LIGHT SNOW OR FLURRIES MONDAY NIGHT-TUESDAY. THE
UPPER TROUGH AXIS EVENTUALLY SLIDES OFF TO THE EAST TUESDAY
NIGHT/WEDNESDAY...WITH WEAK RIDGING ALOFT DEVELOPING AND PRODUCING
DRY CONDITIONS. THE EXCEPTION MAY BE ACROSS LAKE/PORTER COUNTIES IN
NORTHWEST INDIANA WHERE NORTH FLOW AHEAD OF THE APPROACHING SFC
RIDGE WILL LIKELY PRODUCE LAKE EFFECT SNOW SHOWERS TUESDAY
NIGHT/WEDNESDAY.
THE UPPER TROUGH AXIS MOVES EAST OF THE AREA FRIDAY. GUIDANCE
DEPICTS ANOTHER MID-LEVEL SHORT WAVE APPROACHING THE REGION
SATURDAY...THOUGH THE SURFACE LOW AGAIN PASSES NORTH OF THE AREA.
SOME POTENTIAL FOR A LITTLE LIGHT RAIN/SNOW OR LIGHT SNOW SATURDAY
AND SATURDAY NIGHT MAINLY ACROSS NORTHERN PARTS OF THE CWA...THOUGH
THE 12Z ECMWF APPEARS TO BE TRENDING FARTHER NORTH FOR NOW.
TEMPERATURES NEXT WEEK LOOK TO REMAIN SUBSTANTIALLY BELOW NORMAL FOR
LATE NOVEMBER...WITH LOW/MID 30S FOR HIGHS MOST DAYS AND LOWS IN THE
LOW/MID 20S. THIS IS ABOUT 10 DEGREES BELOW OUR NORMAL HIGHS FOR
THIS TIME OF YEAR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* NONE
RC/IZZI
//DISCUSSION...UPDATED 18Z...
COLD FRONT PUSHING THROUGH CENTRAL IL AND STRONG HIGH PRESSURE
OVER THE NORTHERN PLAINS BUILDING SOUTHEAST TO MO BY SUNDAY
MORNING. TIGHT PRESSURE GRADIENT OVER THE WESTERN GREAT LAKES THIS
AFTERNOON WITH WINDS GENERALLY 320-350 DEGREES AND GUSTING TO 25
KT. AS THE HIGH MOVES SOUTHEAST THE PRESSURE GRADIENT WILL
GRADUALLY RELAX ALLOWING WINDS TO DIMINISH TONIGHT. AN AREA OF
MORE SOLID STRATOCU JUST BEHIND THE COLD FRONT HAS MOVED SOUTH OF
THE CHICAGO-ROCKFORD AREAS WITH ONLY SCT STRATOCU REMAINING OVER
NORTHERN IL. HOWEVER AREAS OF STRATOCU FILLING IN UPSTREAM OVER
WI. DON`T ANTICIPATE MUCH EXPANSION OF THIS CLOUD COVER AS A VERY
DRY LOW LEVEL AIRMASS IS SPREADING SOUTH. EXPECT MAINLY SCT CLOUDS
3500-4000 FT THIS AFTERNOON BUT AREAS OF BKN CLOUD
POSSIBLE...REMAINING VFR. MORE SOLID CLOUD COVER OVER NORTHERN IN
DUE TO LAKE EFFECT...WITH GYY EXPECTED TO BE MAINLY BKN AROUND
3000-4000. CLOUDS OVER NORTHERN IL SHOULD DISSIPATE AROUND OR
SHORTLY AFTER SUNSET...WHILE LAKE EFFECT CLOUDS SLOWLY SHIFT
FURTHER EAST OVER NORTH CENTRAL IN DUE TO LOW LEVEL WINDS
GRADUALLY BECOMING MORE NW.
AS THE HIGH SHIFTS EAST INTO THE OHIO VALLEY SUNDAY...WINDS WILL
TURN WEST THEN SOUTHWEST DURING THE DAY SUNDAY.
ALLSOPP
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN ALL ELEMENTS.
RC/IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHC OF SNOW AND IFR WITH LIGHT ACCUMULATION POSSIBLE.
TUESDAY...MVFR AND FLURRIES POSSIBLE IN THE MORNING.
WEDNESDAY-FRIDAY...CHC FOR LAKE EFFECT MVFR CLOUDS BUT MAINLY
VFR.
MTF
&&
.MARINE...
151 PM CST
LOW PRESSURE OVER SOUTHEAST CANADA CONTINUES TO SHIFT EAST WHILE A
STRONG CANADIAN HIGH SINKS INTO THE CENTRAL PLAINS THIS EVENING.
THE HIGH SLOWLY WEAKENS AS IT PASSES OVER THE SOUTHERN MISSISSIPPI
RIVER VALLEY TOMORROW AFTERNOON AND THEN REACHES THE CAROLINAS BY
MONDAY MORNING. NORTHWEST GALES WILL CONTINUE THROUGH THIS EVENING
BEFORE THE THE GRADIENT WEAKENS AND WINDS DIMINISH. ***SOMETHING
ABOUT THE SMALL CRAFT***
AS THE HIGH SHIFTS EAST...A LOW PRESSURE SYSTEM DROPS INTO MANITOBA
SUNDAY EVENING. THE PRESSURE GRADIENT TIGHTENS OVER THE LAKE AND
SOUTHWEST GALES ARE EXPECTED LATE SUNDAY EVENING THROUGH MONDAY
AFTERNOON. ***AS SUCH HAVE ISSUED A GALE WATCH ACROSS THE OPEN
WATERS.*** THE LOW PASSES NORTH OF THE GREAT LAKES MONDAY WITH WINDS
TURNING WEST BEHIND ITS COLD FRONT MONDAY EVENING. WINDS CONTINUE
TO VEER TO THE NORTH TUESDAY NIGHT AS HIGH PRESSURE SHIFTS
SOUTHWEST. THE HIGH/S CENTER PASSES NORTH OF THE GREAT LAKES
WEDNESDAY AFTERNOON. GUIDANCE DIFFERS ON THE PATTERN AFTER
WEDNESDAY WITH THE ECMWF INDICATING THE HIGH WILL DISSIPATE WHILE A
LOW MOVES OVER THE LAKE THURSDAY EVENING. THE GFS ON THE OTHER HAND
HAS THE HIGH SHIFTING EAST AND THE NEXT LOW STAYING WELL NORTH OF
THE LAKES AND OVER HUDSON BAY. THEREFORE FOR NOW WILL HAVE WEAK
SOUTH WINDS ON THURSDAY BECOMING NORTHWEST.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM
SATURDAY.
GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...9 PM SUNDAY TO 9 PM
MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 3 PM
SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
242 PM CST Sat Nov 23 2013
.DISCUSSION...
ISSUED 230 PM CST Sat Nov 23 2013
1050 mb Arctic high pressure centered over northeast South Dakota
early this afternoon has brought a real taste of winter weather to
the area. Clouds quickly increased along the leading edge of the
Arctic air mass late this morning to our north and that band of
clouds and flurries has quickly spread south early this afternoon.
Temperatures were not going anywhere with readings ranging from
the mid 20s north to the lower 30s far southeast. Wind chills were
the real story today with most areas in the 10 to 20 degree range
early this afternoon.
SHORT TERM...Tonight through Tuesday
Temperatures the main forecast concern this period along with
light snow chances Monday as another cold blast settles southeast
into the region.
The center of the cold air mass will edge over our area by Sunday
morning bringing very cold temperatures to the entire forecast
area with early morning lows from around 5 far northwest to the low
teens far southeast. Wind chill indices will range from 0 to 5 below.
The large high pressure system will drift off to our east by late
Sunday bringing another cold day to our area but with much lighter
winds. Return flow sets up across the west Sunday night as the high
shifts well off to our east with deeper moisture from the cutoff low
over the southern Plains and a northern stream wave and cold front
approach from the northwest.
Prefer the more consistent look to the GFS and past few runs of the
ECMWF which brings some decent isentropic lift into our area Monday
morning as pressure deficits lower suggesting we may see a period of
light snow by mid to late morning which should track east over the
remainder of the forecast area by afternoon. At this time, snowfall
looks to be quite light, less than an inch, especially across the
north. The NAM seems to be too agressive with the moisture transport
north into the colder air compared to the GFS and ECMWF with the
latest ECMWF splitting the two significant areas of lift, with one
area of forcing tracking to our north later on Monday, while the
second area of lift and moisture associated with the southwest
cutoff tracks just south of I-70.
The southwest system is expected to eject rather quickly northeast
into eastern TN by late Tuesday keeping the more significant rain
and snow just south of our area. Meanwhile, further north, another
Arctic surge is forecast to drop 850 temps down to between -12 and
-15 by late Tuesday night accompanied by rather gusty north winds
again thanks to the deepening storm system off to our southeast.
Another night with temperatures in the teens to middle 20s with
wind chills down into the single digits north to the low-mid teens
southeast.
LONG TERM...Wednesday through Saturday
Split flow pattern to prevail through the week featuring several
fast moving shortwaves in the northern stream, which will influence
our weather, while another cutoff low moves into southern California
by Friday. That feature will then move in a similar way to the current
upper low over the southwest U.S. this weekend, affecting the southern
Plains beyond this forecast period.
We will start out rather cold midweek as the next Arctic air mass
settles across the Midwest, but the upper pattern will deamplify
somewhat by the end of the week bringing in slightly warmer air to
our area by Friday and Saturday when afternoon temperatures rise
into the upper 30s to lower 40s, which is still well below normal
for this time of year. Precip-wise...little if any rain or snow
is expected this period with our only chances coming along with
the disturbances in the northern stream late in the week. However,
forcing and deeper moisture will be lacking with these systems so
will continue to go with a dry forecast through Saturday.
Smith
&&
.AVIATION...
ISSUED 1131 AM CST Sat Nov 23 2013
Large area of diurnal cloud cover has developed and spread across
central Illinois late this morning. Based on satellite timing tools
and to a lesser extent the latest HRRR data, think MVFR ceilings
will persist at the terminals until after 20/21z. Once clouds
dissipate/track further southeastward, clear skies are expected
tonight into Sunday. Strong northwesterly winds gusting to between
20 and 25kt will gradually subside to around 10kt toward sunset.
As high pressure builds into the Illinois River Valley late
tonight into Sunday morning, winds will become light/variable at
KPIA, but will remain northwesterly at around 5kt at the remaining
TAF sites.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1146 AM CST SAT NOV 23 2013
.DISCUSSION...
1056 AM CST
FOR MORNING UPDATE...
A COUPLE OF MINOR CHANGES TO GOING FORECAST THIS MORNING. MADE SOME
TWEAKS TO MAX/HOURLY TEMPS THROUGH THE AFTERNOON HOURS AND
MAINTAINED SOME SCATTERED FLURRIES ACROSS THE SOUTHERN CWA INTO
EARLY AFTERNOON.
ARCTIC COLD FRONT PUSHED SOUTH ACROSS THE FORECAST AREA EARLY THIS
MORNING. TEMPS HAVE REACHED HIGHS IN THE LOW-MID 20S ACROSS THE
NORTHERN HALF OR SO OF THE FORECAST AREA...WITH STRONG COLD
ADVECTION EXPECTED OFFSET ANY SUN-INDUCED WARMING. FARTHER SOUTH
TEMPS HAVE RISEN INTO THE UPPER 20S...BUT WILL LIKELY FALL A COUPLE
DEGREES THIS AFTERNOON OF DEGREES AS COLDER AIR SURGES SOUTH. AREA
OF STRATOCU ACROSS THE CENTRAL/SOUTHERN PARTS OF THE CWA HAVE BEEN
PRODUCING FLURRIES...AND WILL CONTINUE TO DO SO ACROSS THE SOUTHERN
COUNTIES INTO EARLY AFTERNOON AHEAD OF STRONG MID-LEVEL VORT
PROPAGATING SOUTHEASTWARD ACROSS THE AREA. OTHERWISE...VERY DRY LOW
LEVEL ARCTIC AIR WITH DEW POINT TEMPS IN THE SINGLE DIGITS IS
SPREADING ACROSS THE REGION AND SHOULD PRECLUDE MUCH IN THE WAY OF
ADDITIONAL DEEPER STRATOCU OR FLURRIES ONCE THE VORT DEPARTS.
OTHERWISE...PARTLY CLOUDY...WINDY AND COLD ARE THE WEATHER WORDS FOR
THE REMAINDER OF THE DAY.
THUS HAVE MADE SOME ADJUSTMENTS TO HOURLY TEMPS AND MAX TEMP GRIDS
AS OUTLINED ABOVE...AND HAVE MAINTAINED SCATTERED FLURRIES INTO THE
EARLY AFTERNOON HOURS ACROSS THE SOUTH.
RATZER
//PREV DISCUSSION...
308 AM CST
THE VERY COLD AIR IS RIGHT ON OUR DOOR STEP EARLY THIS MORNING. THE
MAIN FORECAST CONCERNS CONTINUE TO FOCUS ON THE UNSEASONABLE COLD
CONDITIONS EXPECTED ACROSS THE AREA TODAY AND ON SUNDAY.
THE ARCTIC FRONT IS CURRENTLY ENTERING FAR NORTHERN ILLINOIS AS OF
THIS WRITING...AND THIS FRONT WILL CONTINUE TO SHIFT SOUTHWARD
ACROSS THE AREA THROUGH THE EARLY MORNING HOURS TODAY. ONCE THE
FRONT PASSES...EXPECT THE WINDS TO QUICKLY INCREASE OUT OF THE
NORTHWEST. A STRONG AREA OF SURFACE HIGH PRESSURE...CURRENTLY AROUND
1050 MB ACROSS NORTHWESTERN NORTH DAKOTA...WILL BUILD SOUTHWARD DOWN
THE MISSOURI RIVER VALLEY THROUGH THE DAY TODAY. AS THIS
OCCURS...THIS WILL DEVELOP A RATHER STOUT SURFACE PRESSURE GRADIENT
ACROSS THE REGION. THIS GRADIENT WILL LIKELY SUPPORT WIND SPEEDS OF
20 TO 25 MPH WITH GUSTS UP TO 35 MPH FOR MUCH OF THE DAY. THE
COMBINATION OF THESE WINDS WITH TEMPERATURES IN THE LOW TO MID
20S...WILL RESULT IN WIND CHILLS OF 5 TO 10 ABOVE NORTH TO 10 TO 15
ABOVE SOUTH.
IN ADDITION TO THE STRONG COLD WINDS...A SHEARED MID LEVEL
DISTURBANCE...CURRENTLY NOTED IN THE WATER VAPOR IMAGERY DROPPING
SOUTHEASTWARD ACROSS SOUTHERN MN...COULD PRODUCE ENOUGH LIFT TO
RESULT IN SOME LIGHT SNOW FLURRIES THIS MORNING AS THE COLDER AIR
ARRIVES. THERE HAVE BEEN NUMEROUS REPORTS OF THIS ALREADY UPSTREAM
ACROSS WI...AND I SEE NO REASON WHY THIS WILL NOT CONTINUE SOUTHWARD
THIS MORNING. ALTHOUGH THIS WILL NOT BE MUCH OF AN IMPACT...I DID
ADD SOME ISOLATED FLURRIES IN THROUGH MID MORNING. WITH PLENTY OF
STRATOCU CU EXPECTED IN THE WAKE OF THE FRONT...I ALSO INCREASED SKY
COVER TO GO PARTLY SUNNY TO MOSTLY CLOUDY THIS MORNING...TRENDING
MORE PARTLY CLOUDY THIS AFTERNOON.
TONIGHT STILL APPEARS TO BE A VERY COLD NIGHT...ESPECIALLY ACROSS
WESTERN SECTIONS OF THE AREA. THE SURFACE HIGH IS EXPECTED TO BECOME
CENTERED ACROSS NORTHERN MISSOURI BY 12 UTC SUNDAY...WHICH WILL
LIKELY ALLOW FOR ENOUGH OF A GRADIENT TO KEEP SOME NORTHWEST WINDS
GOING ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA. THIS
SHOULD ALLOW FOR SLIGHTLY WARMER CONDITIONS HERE...BUT OUT WEST
ACROSS NORTH CENTRAL ILLINOIS...THE WINDS SHOULD DIMINISH SOME
OVERNIGHT...AND THIS SHOULD ALLOW TEMPS TO DROP INTO THE SINGLE
DIGITS. FARTHER EAST TOWARDS THE CHICAGO AREA...TEMPERATURES ARE
STILL EXPECTED TO DROP IN THE LOWER TO MIDDLE TEENS.
THESE VERY COLD CONDITIONS WILL SUPPORT SOME LAKE EFFECT SNOW SHOWERS
LATER TODAY AND TONIGHT. HOWEVER...WITH A NORTHWESTERLY BOUNDARY
LAYER FLOW OVER THE LAKE...MUCH OF THIS ACTIVITY WILL REMAIN TO THE
EAST OF MY AREA...WITH ONLY NORTHEASTERN PORTER COUNTY POSSIBLY
GETTING SOME LIGHTER SNOW.
THIS COLD START TO SUNDAY WILL LIKELY ONLY ALLOW TEMPS TO REBOUND
INTO THE MIDDLE TO PERHAPS UPPER 20S SUNDAY AFTERNOON. THE SURFACE
FLOW SHOULD TURN SOUTHWESTERLY SUNDAY AFTERNOON AS THE SURFACE HIGH
CONTINUES TO SHIFT SOUTHEASTWARD TOWARDS THE TENNESSEE VALLEY. WIND
SPEEDS WILL LIKELY INCREASE SUNDAY NIGHT INTO MONDAY...SO THIS
SHOULD NOT ALLOW TEMPS TO DROP OFF MUCH SUNDAY NIGHT.
A CLIPPER SYSTEM IS EXPECTED TO TRACK ACROSS SOUTHERN ONTARIO INTO
MONDAY. AS IT DOES SO...IT SHOULD SET UP SOME STIFF SOUTHWESTERLY
FLOW AS THE SURFACE GRADIENT STRENGTHENS BETWEEN THE CLIPPER AND
THE SURFACE HIGH SETTING UP ACROSS THE SOUTHEASTERN CONUS. THIS
INCREASE IN SOUTHWESTERLY FLOW APPEARS THAT IT WILL ALSO SET UP
SOME GOOD ISENTROPIC ASCENT ACROSS NORTHERN ILLINOIS ON MONDAY.
THIS COMBINED WITH A GLANCING BLOW OF SOME OF THE BETTER 500-300
MB Q-VECTOR CONVERGENCE...COMPLEMENTS OF THE UPPER DISTURBANCE
DIGGING ACROSS THE GREAT LAKES...MAY BE ENOUGH TO PRODUCE SOME
LIGHT SNOW ACROSS THE AREA ON MONDAY. OVERALL...THIS WILL NOT BE A
BIG SNOW MAKER FOR US AS IT APPEARS THAT MOISTURE WILL BE
SOMEWHAT LIMITED. ANOTHER STORM SYSTEM EXPECTED TO BE TAKING SHAPE
ACROSS THE GULF COAST REGION MAY ROB A LOT OF THE BETTER MOISTURE.
HOWEVER...THERE COULD CERTAINLY BE ENOUGH FORCING AND MOISTURE TO
RESULT IN SOME LIGHT ACCUMULATIONS ACROSS THE AREA ON MONDAY...SO
THIS WILL HAVE TO BE MONITORED. I HAVE INCREASED POPS INTO THE
HIGH END CHANCE CATEGORY...MAINLY FOR NORTHERN ILLINOIS...CLOSER
TO THE BETTER UPPER FORCING.
ANOTHER DECENT REINFORCING SHOT OF COLD AIR WILL DROP ACROSS THE
REGION BY TUESDAY AS THE CLIPPER SYSTEM DROPS ANOTHER COLD FRONT
ACROSS THE AREA. THERE IS A SLIGHT CHANCE THAT SOME FLURRIES COULD
ACCOMPANY THIS COLDER AIR INTO TUESDAY...ESPECIALLY CONSIDERING THAT
ANOTHER MID LEVEL DISTURBANCE IS EXPECTED TO QUICKLY TRANSITION
SOUTHEASTWARD ACROSS THE AREA. THIS COULD AGAIN RESULT IN ENOUGH
FORCING TO SQUEEZE OUT SOME LIGHT SNOW FLURRIES.
WITH THIS NEXT COLD PUSH...ANOTHER SURFACE HIGH WILL LIKELY SHIFT
SOUTHEAST SOMEWHERE ACROSS THE GREAT LAKES INTO MIDWEEK. THE
NORTHERLY FLOW THIS SETS UP COULD PRODUCE SOME MORE LAKE EFFECT SNOW
INTO NORTHWESTERN INDIANA BY WEDNESDAY.
TOWARDS THE END OF NEXT WEEK...THE PARADE OF CLIPPER SYSTEMS WILL
CONTINUE...WITH YET ANOTHER ONE EXPECTED TO TRANSITIONS TO OUR NORTH
BY LATE WEEK. TEMPERATURES THROUGH THE PERIOD LOOK TO CONTINUE ON
THE COLD SIDE OF NORMAL...WITH ONLY A SLOW MODERATION EXPECTED LATER
IN THE WEEK.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NNW WINDS GUSTING TO 25 KT THIS AFTERNOON DIMINISHING OVERNIGHT.
ALLSOPP
//DISCUSSION...UPDATED 18Z...
COLD FRONT PUSHING THROUGH CENTRAL IL AND STRONG HIGH PRESSURE
OVER THE NORTHERN PLAINS BUILDING SOUTHEAST TO MO BY SUNDAY
MORNING. TIGHT PRESSURE GRADIENT OVER THE WESTERN GREAT LAKES THIS
AFTERNOON WITH WINDS GENERALLY 320-350 DEGREES AND GUSTING TO 25
KT. AS THE HIGH MOVES SOUTHEAST THE PRESSURE GRADIENT WILL
GRADUALLY RELAX ALLOWING WINDS TO DIMINISH TONIGHT. AN AREA OF
MORE SOLID STRATOCU JUST BEHIND THE COLD FRONT HAS MOVED SOUTH OF
THE CHICAGO-ROCKFORD AREAS WITH ONLY SCT STRATOCU REMAINING OVER
NORTHERN IL. HOWEVER AREAS OF STRATOCU FILLING IN UPSTREAM OVER
WI. DON`T ANTICIPATE MUCH EXPANSION OF THIS CLOUD COVER AS A VERY
DRY LOW LEVEL AIRMASS IS SPREADING SOUTH. EXPECT MAINLY SCT CLOUDS
3500-4000 FT THIS AFTERNOON BUT AREAS OF BKN CLOUD
POSSIBLE...REMAINING VFR. MORE SOLID CLOUD COVER OVER NORTHERN IN
DUE TO LAKE EFFECT...WITH GYY EXPECTED TO BE MAINLY BKN AROUND
3000-4000. CLOUDS OVER NORTHERN IL SHOULD DISSIPATE AROUND OR
SHORTLY AFTER SUNSET...WHILE LAKE EFFECT CLOUDS SLOWLY SHIFT
FURTHER EAST OVER NORTH CENTRAL IN DUE TO LOW LEVEL WINDS
GRADUALLY BECOMING MORE NW.
AS THE HIGH SHIFTS EAST INTO THE OHIO VALLEY SUNDAY...WINDS WILL
TURN WEST THEN SOUTHWEST DURING THE DAY SUNDAY.
ALLSOPP
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM-HIGH CONFIDENCE IN CLOUD FORECAST. MOSTLY SCT CLOUDS BUT
COULD BE AREAS OF CIGS 3500-4000 FT THIS AFTERNOON.
ALLSOPP
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHC OF SNOW AND IFR WITH LIGHT ACCUMULATION POSSIBLE.
TUESDAY...MVFR AND FLURRIES POSSIBLE IN THE MORNING.
WEDNESDAY-FRIDAY...CHC FOR LAKE EFFECT MVFR CLOUDS BUT MAINLY
VFR.
MTF
&&
.MARINE...
145 AM CST
THE ACTIVE LATE AUTUMN PATTERN CONTINUES OVER THE GREAT LAKES WITH
AN ONGOING GALE TODAY FOLLOWING A COLD FRONTAL PASSAGE THAT OCCURRED
LAST NIGHT. ROBUST ARCTIC HIGH PRESSURE ACROSS THE NORTHERN PLAINS
THIS MORNING WILL BUILD SOUTHEAST AND KEEP A FAIRLY TIGHT PRESSURE
GRADIENT OVER THE LAKE. THIS WILL BE ENHANCED ONE AGAIN SUNDAY NIGHT
AS A LOW PRESSURE...OF 40 MB DIFFERENCE FROM THE HIGH
CENTER...SLIDES ACROSS THE CANADIAN PRAIRIE PROVINCES INTO ONTARIO.
WHILE IT WILL BE WARMER AIR RETURNING AHEAD OF THE LOW ON SUNDAY
NIGHT INTO EARLY MONDAY...THAT AIR WILL STILL BE FAR COOLER THAN THE
LAKE SURFACE TEMPERATURES SETTING THE STAGE FOR DEEP MIXING WITHIN
THAT PRESSURE GRADIENT. SOME GUSTS NEARING STORM FORCE ARE POSSIBLE
ACROSS THE NORTH. AN ASSOCIATED COLD FRONT WILL THEN MOVE ACROSS THE
LAKE MONDAY NIGHT AND THAT TOO MAY CONTINUE SOME GALES. USING THE
CIPS ANALOGS THERE ARE A COUPLE PAST EVENTS WITH SIMILAR LOW AND
HIGH PRESSURE PLACEMENT AS TO MONDAY MORNING...THOUGH NOT AS SHARP
OF A PRESSURE DIFFERENCE. THEY DO SHOW AT LEAST GALES ALONG THE
MICHIGAN SHORE SO GALES SHOULD BE PRETTY MUCH A DEFINITE OVER THE
OPEN WATER BY DAYBREAK MONDAY. HIGH PRESSURE THEN LOOKS TO MOVE OVER
THE LAKE BY WEDNESDAY INTO THE HOLIDAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM
SATURDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 3 PM
SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1131 AM CST Sat Nov 23 2013
.DISCUSSION...
ISSUED 1038 AM CST Sat Nov 23 2013
Much colder airmass is flowing into central Illinois this morning
behind a departing frontal boundary. Thanks to steep low-level
lapse rates, an area of diurnal CU has rapidly developed and
expanded across north-central Illinois over the past hour. Clouds
are dropping southward and will overspread much of the KILX CWA
except the far southwest around Jacksonville through midday. Given
favorable lapse rates seen on local LAPS soundings and rapid cloud
development, would not be surprised to see a few snow flurries as
well. Have updated the forecast to better reflect current sky
trends and to add flurries. Otherwise, windy and cold weather will
be the rule. Wind gusts will reach the 25 to 30 mph range,
creating wind-chill values in the teens. Actual air temperatures
will remain nearly steady or slowly fall through the 20s during
the afternoon.
Barnes
&&
.AVIATION...
ISSUED 1131 AM CST Sat Nov 23 2013
Large area of diurnal cloud cover has developed and spread across
central Illinois late this morning. Based on satellite timing tools
and to a lesser extent the latest HRRR data, think MVFR ceilings
will persist at the terminals until after 20/21z. Once clouds
dissipate/track further southeastward, clear skies are expected
tonight into Sunday. Strong northwesterly winds gusting to between
20 and 25kt will gradually subside to around 10kt toward sunset.
As high pressure builds into the Illinois River Valley late
tonight into Sunday morning, winds will become light/variable at
KPIA, but will remain northwesterly at around 5kt at the remaining
TAF sites.
Barnes
&&
.PREV DISCUSSION...
ISSUED 320 AM CST Sat Nov 23 2013
An arctic cold front to pass through IL dry this morning. Below
normal temperatures expected across central IL through at least
Thanksgiving with upper level trofing into the eastern states.
Generally dry conditions expected expect for a chance of light
snow on Monday over mainly northern areas due to a northern stream
system moving into the Great Lakes region with yet another polar
cold front moving through Monday night.
SHORT TERM...Today through Monday night
An arctic cold front extending from weak 1020 mb low pressure over
northern Lake Huron through nw IL (approaching Rockford and the
Quad Cities), southern IA and central NE. 1050 mb arctic high
pressure was over nw ND and over se Saskatchewan and sw Manitoba.
Cirrus clouds are spreading east across central and southern IL
from the central plains ahead of this cold front. Temperatures
range from the lower 20s nw of the IL river to the lower 30s from
I-70 southeast.
Arctic cold front to pass quickly se across central and southeast
IL during this morning with brisk nw winds gusting to 20 to 30 mph
behind this front during mid or late morning and into this afternoon
as arctic high pressure pushes into western parts of MN/IA by sunset.
Temps to only rise slightly this morning into the mid 20s nw of
the IL river and near 37F at Lawrenceville before slowly falling
behind the cold front later this morning and afternoon. Partly to
mostly sunny skies expected today with cirrus clouds shifting
southward during the morning while stratocumulus clouds to affect
ne areas by midday and be more prominent over Indiana with nw flow
off warmer waters of Lake MI.
High pressure weakens a bit to 1046 mb as it moves into northern
MO by dawn Sunday clearing skies early this evening over central
IL and diminishing winds. This to bring the coldest night of the
season with lows in the upper single digits over central IL and
lower teens in southeast IL. Wind chills to get as cold as zero to
minus 5 over central IL overnight into early Sunday morning. High
pressure continues to weaken to 1038 mb as it settles into the mid
MS and OH river valleys by sunset Sunday. This to bring ample
sunday and lighter winds Sunday to central IL but staying cold
with highs in the mid to upper 20s. High pressure drifts east into
the mid Atlantic states by dawn Monday while still ridging
westward into the mid MS valley and keeping fair and cold weather
over central/se IL. Lows Sunday night in the mid to upper teens
with coldest readings in east central IL.
A northern stream short wave dives se toward the Great Lakes
region late Monday and Monday night driving a another polar cold
front se through IL. ECMWF and GFS models brings some light qpf
into central and northern IL Monday while NAM still keeping it
drier. Will add 20-40% chance of light snow to areas from I-72
north Monday. Low levels are fairly dry so this will limit snow
chances and amounts. Mostly cloudy skies Monday with highs in the
mid to upper 30s.
LONG TERM...Tuesday through Saturday
Strong 555 dm 500 mb low spining off the Southern CA coast near
San Diego to track east and develop a stronger storm system over
the southern plains Monday, into the southeast States Tuesday and
up the East Coast Wednesday, and departing the Northeast by
Thanksgiving. Extended models have been consistent on keeping this
moisture south and east of IL while reinforcing colder air into
the region for the middle of next week as 850 mb temps get as cold
as 10-14C. So below normal temperatures likely through at least
Thanksgiving. Temperatures to gradually modify next Friday and
Saturday as upper level heights and 850 mb temps rise and dry
conditions still prevail which GFS and ECWMF both agree on.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
400 PM EST SAT NOV 23 2013
.SYNOPSIS...
ISSUED AT 458 AM EST SAT NOV 23 2013
A STRONG COLD FRONT WILL TRACK ACROSS THE REGION EARLY THIS MORNING
AND RESULT IN BRISK AND COLDER CONDITIONS. ALONG WITH THE COLDER AIR
WILL COME INCREASING IN LAKE EFFECT SNOW SHOWERS ACROSS FAR
NORTH CENTRAL INDIANA AND SOUTHWEST LOWER MICHIGAN THROUGH
THROUGH SUNDAY MORNING. ONLY A SLIGHT MODERATION FROM THE COLD
CONDITIONS CAN BE EXPECTED MONDAY BEFORE YET ANOTHER COLD FRONT
DROPS THROUGH THE REGION ON TUESDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 400 PM EST SAT NOV 23 2013
ARCTIC AIRMASS ASSOCIATED WITH 1050MB SURFACE HIGH IS CURRENTLY
ENGULFING THE REGION...LEADING TO FALLING TEMPS AND A DECENT LAKE
RESPONSE. 850MB TEMPS CONTINUE TO FALL INTO THE UPPER TEENS BELOW
ZERO AND 700MB DELTA-T`S ARE AT OR ABOVE 30C. CERTAINLY PLENTY OF
LAKE INDUCED INSTABILITY BUT DEGREE OF UPSTREAM DRY AIR AND LOW
LEVEL FLOW TRAJECTORIES REMAIN A LIMITING FACTOR. AS PREVIOUSLY
MENTIONED...SURFACE DEWPOINTS OVER WISCONSIN ARE HOVERING AT OR
BELOW ZERO. 330 DEGREE SURFACE WINDS GIVE A DECENT FETCH ALONG LAKE
MICHIGAN BUT MOISTURE AND SENSIBLE/LATENT HEAT FLUX CAN ONLY DO SO
MUCH...ESPECIALLY GIVEN STRONG GRADIENT AND MARGINAL UPSTREAM
PRECONDITIONING FROM WESTERN LAKE SUPERIOR. THIS IS BORNE OUT BY
RELATIVELY DRY NEAR SURFACE PROFILES ON FORECAST SOUNDINGS AND
CEILINGS GENERALLY ABOVE 3 KFT DURING THE DAY TODAY. DRY AIR ALOFT
IS ALSO PREVENTING CONVECTIVE DEPTHS FROM GETTING MUCH ABOVE 7
KFT...PER NAM AND RAP FORECAST SOUNDINGS. APPEARS TO BE SOME
SEMBLANCE OF FRICTIONAL CONVERGENCE OR THERMALLY-INDUCED PRESSURE
TROUGHING ALONG THE EASTERN SHORE OF LAKE MICHIGAN BUT STRONG
NORTHWEST GRADIENT IS DISRUPTING THE FORMATION OF A SINGLE DOMINANT
BAND AND HEAVIER SNOW SHOWERS HAVE BEEN FAIRLY SPORADIC AND
DISORGANIZED THROUGHOUT THE DAY. 12Z HI-RES GUIDANCE SUGGESTS BANDS
MAY BECOME A LITTLE BETTER ORGANIZED OVERNIGHT BUT THE
AFOREMENTIONED LIMITING FACTORS WILL REMAIN LARGELY IN PLACE THROUGH
THE MORNING WITH A STIFF NORTHWEST WIND...PERSISTENT SYNOPTIC-SCALE
DRY AIR ADVECTION...AND A WELL MIXED BOUNDARY LAYER. STRONG
INSTABILITY...LONG DURATION...AND NEARLY IDEAL DGZ PLACEMENT WILL
CONTINUE TO AT LEAST PARTIALLY OFFSET THOSE NEGATIVE FACTORS THOUGH
AND WILL CONTINUE TO SEE SPURTS OF HEAVIER SNOW SHOWERS THROUGH
TOMORROW MORNING THAT COULD EVENTUALLY ADD UP TO 3-5 INCHES IN THE
ADVISORY AREA. STILL DONT EXPECT WARNING CRITERIA SNOWFALL. THE ONLY
POSSIBLE EXCEPTION MAY BE IN CASS COUNTY MI WHERE 5-8 INCHES MAY BE
POSSIBLE IF A MORE ORGANIZED/FOCUSED BAND DEVELOPS BUT CONFIDENCE IN
THIS OCCURRING IS TOO LOW TO WARRANT AN UPGRADE AT THIS POINT.
BACKING LOW LEVEL WINDS AND PERSISTENT SUBSIDENCE/DRY AIR ADVECTION
WILL BRING AN END TO LAKE AFFECT SNOW SHOWERS AROUND MIDDAY TOMORROW.
OTHER MAIN STORY DURING THIS SHORT TERM PERIOD WILL BE THE VERY COLD
TEMPERATURES. STRONG GRADIENT AND LAKE INDUCED CLOUD COVER WILL
PREVENT ANY DECOUPLING OR RADIATIVE COOLING OVERNIGHT FOR MOST OF
OUR CWA BUT VERY COLD THERMAL PROFILES ADVECTING INTO THE AREA WILL
STILL SUPPORT LOWS GENERALLY IN THE MID TEENS. COMBINED WITH THE
WIND...IT WILL FEEL LIKE THE LOW SINGLE DIGITS IN SOME AREAS. HIGHS
TOMORROW WILL STRUGGLE TO GET OUT OF THE MID 20S GIVEN 925MB TEMPS
STILL AROUND -11C. MODELS CONTINUE TO STRUGGLE WITH THE MAGNITUDE OF
THIS COLD AIRMASS AND HAVE CONTINUED TO LEAN ON THE COOLER SIDE OF
GUIDANCE.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 PM EST SAT NOV 23 2013
PREFERENCE THIS AFTN LIES W/SHARPER H5 EVOLUTION ALOFT MID PD IN
RESPONSE TO EWD EJECTION OF STG SRN STREAM SW UNDERNEATH AMPLIFYING
NRN STREAM ACRS THE WRN LAKES WHICH PROVIDES A PATHWAY FOR SOME XPCD
PHASING ALOFT. AS SUCH AND IN TANDEM W/GEM/NAM/EC TRENDS...BUMPED
POPS CONSIDERABLY WED-THU FOR WHAT SHLD BE A SIG LK EFFECT SNOW
EVENT AS YET ANOTHER SURGE OF COLD CANADIAN AIR FUNNELS SWD ACRS THE
LAKES.
STEEP NW FLW ALOFT CONTS THROUGH THE END OF THE PD W/PROMISE OF
CONTD WELL BLO NORMAL TEMPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1246 PM EST SAT NOV 23 2013
ARCTIC COLD FRONT HAS NOW CLEARED BOTH TERMINALS AND VERY COLD
AIRMASS BEHIND IT HAS IGNITED NUMEROUS LAKE EFFECT SNOW SHOWERS
ACROSS THE AREA. RECENT RADAR/SURFACE OBSERVATIONS AND 12Z HI-RES
GUIDANCE SUGGEST THE STRONGEST BANDS WILL REMAIN NORTHEAST OF KSBN
BUT A FEW WEAKER BANDS COULD IMPACT THE TERMINAL THROUGH TONIGHT
WITH BRIEF IFR VISIBILITIES. KFWA COULD ALSO SEE A FEW SNOW
SHOWERS THIS AFTERNOON AND OVERNIGHT BUT IMPACT SHOULD REMAIN
LIMITED GIVEN DISTANCE FROM THE LAKE. STRONG TURBULENT MIXING AND
VERY DRY UPSTREAM AIRMASS WILL LIKELY KEEP CEILINGS IN MVFR OR
BETTER CATEGORY AT BOTH TERMINALS THROUGH THE PERIOD WITH LAKE
EFFECT SNOW TAPERING OFF LATE TOMORROW MORNING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST SUNDAY FOR INZ004>006.
MI...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST SUNDAY FOR MIZ077>079.
OH...NONE.
LM...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LMZ043-046.
&&
$$
SYNOPSIS...MURPHY
SHORT TERM...AGD
LONG TERM...T
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
219 PM CST Sat Nov 23 2013
...Updated short term discussion...
.SYNOPSIS...
ISSUED AT 1109 AM CST SAT NOV 23 2013
At 12z Saturday a -25c 500mb low was located over southern
California. A 300mb +100kt jet streak extended from the based of
this upper low northeast into the four corners region. A 700mb to
500mb deformation zone was located from Wyoming, across Colorado,
into Oklahoma and a 700mb baroclinic zone extended from southern
Colorado into northern Oklahoma. Along and south of this
baroclinic zone was also where the better 850mb to 500mb moisture
appears to be located based on upper air analysis. A surface to
850mb ridge axis extended from northeast New Mexico into southern
Nebraska. An area of high pressure at the surface at 12z was
located over the eastern Dakotas. The Dodge City sounding this
morning indicated a of drier air was located in the 900mb to 750mb
layer, however the Amarillo sounding indicated a deep layer of
moisture extending from the surface to the 700mb layer.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 218 PM CST SAT NOV 23 2013
Models this morning were all in decent agreement with the
southern California upper low slowly moving east across the
southwest United States over the next 24 hours. Ahead of this
upper trough, isentropic lift and moisture on the I290 and I295
surfaces will improve across southwest Kansas. As this moisture
and lift improves the clouds will thicken and lower with even some
light snow becoming possible across far southwest Kansas after 03z
based on the NAM. The latest HRRR was even a bit more aggressive
with the precipitation spreading into southwest Kansas after 00z
Sunday, and currently given the precipitation that was already
occurring near Amarillo as of 19z will begin to trend toward this
slightly quicker solution. This area of light snow will then
spread north and east through the overnight period but the better
moisture return and isentropic lift still appears to be confined
near and south of the Oklahoma border overnight. As a result not
expected much in the way of accumulation until the 300mb jet,
which was located over Arizona at 12z, begins to approach
southwest Kansas after 06z. Possible exception to this will be
extreme southwest Kansas near Elkhart.
Steady light snow will spread across southwest Kansas after 06z
Sunday as synoptic scale lift improves. Given that the moisture
and low level isentropic lift will already be in place am
currently leaning towards the NAM in snowfall amounts from roughly
06z to 18z Sunday. As a result snow amounts ranging from one to
around two inches still appear reasonable south of a Ulysses to
Dodge City to Pratt line. The higher 2 inch amounts will be mainly
confined near the Oklahoma border on Sunday. Given snow amounts of
around 2 inches being possible near the Oklahoma border was
considering a winter weather advisory, however at this time given
that this is expected to be only a marginal event over a small
area have decided to hold off with any type of headlines. Snow
accumulations of less than one inch is likely further north given
the late timing of the isentropic lift and depth of dry air
forecast in the lower levels.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 150 PM CST SAT NOV 23 2013
Moderation of temperatures is expected in the extended period.
Values will start below normal Monday and end up around normal by
next Saturday. No precipitation is expected during the period as
moisture will remain well southeast of the area. A series of weak
front will move across the region next week with the main impact in
the form of wind shifts.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1109 AM CST SAT NOV 23 2013
VFR cigs will gradually lower this evening with MVFR cigs
developing at DDC and GCK after 03z as the lower levels of the
atmosphere saturates. Light snow will then be possible towards 12z
at DDC and GCK with ceilings continuing to lower to near IFR
criteria at DDC and GCK. At HYS the latest BUFR soundings
indicating VFR conditions likely through early Sunday morning.
Northeast winds at 10 to near 15 knots will decrease after sunset
and then gradually veer to the southeast overnight, as an area of
high pressure at the surface moves from the northern plains into
the mid Mississippi valley.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 18 29 23 37 / 20 30 10 10
GCK 18 30 21 38 / 20 30 10 10
EHA 22 29 23 35 / 80 60 10 10
LBL 22 30 22 34 / 80 70 10 10
HYS 13 31 20 39 / 0 20 10 10
P28 17 28 24 36 / 30 50 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burgert
LONG TERM...Sugden
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS PADUCAH KY
212 PM CST Sat Nov 23 2013
.SHORT TERM...(This Evening through Sunday)
ISSUED AT 151 PM CST SAT NOV 23 2013
High confidence in short term. Very cold through the weekend.
Expect a real test of the pipes with nearly 40 hours of below
freezing temperatures this weekend. With one possible exception
around noon Sunday could slip above freezing for a few hours. We
did tap into the extremely dry aloft...around 10 percent rh...for
a couple hours today as dew points dropped below any horizontal
advection values...but have since risen considerably as the mixing
layer shallowed with the suns angle decline. Winds will back off
overnight and lose a lot of the gusts but they are not expected to
diminish at least until Sunday. A southerly flow is not expected
until next week.
.LONG TERM...(Sunday Night through Saturday)
ISSUED AT 151 PM CST SAT NOV 23 2013
Focus will continue to be on how to handle the complex mid
tropospheric pattern forecast to take shape across the conus early
to mid week. Upper cut off low over the SW U.S. is forecast to
track east Sunday through Monday, reaching S/SW Texas by 12z
Tuesday. Northern stream flow will remain strong out of Canada with
a general trof over the east Canada into the NE U.S. and Great Lakes
region. A lot could be written about model trends and the details.
We will refer you to WPC and their Model Diagnostic Discussion for
the extensive details (product PMDHMD). In short summary, the GFS
has been the most consistent (relatively speaking) model since
Thursday. It continues to keep the southern stream h5 low separate
and mostly uninfluenced by the northern steam, while the other
models are having difficulty in whether or not there will be
phasing aspect. This will depend on how much energy can dig SSE into
the Great Lakes, Upper Midwest mid level trof. The NAM has been
discounted at this time. The 12z UKMET favors the GFS and prior
ECMWF runs (not the 12z). Will use a blend of those models.
All in all, this will result in little change in the forecast.
Monday afternoon, and night, we will introduce some sprinkles or
flurries pretty much area wide, as the GFS tries to saturate the
925-700mb layer from the west ahead of trofs at h8/h7. This
elongated band has been present in the GFS for several model runs
now. Monday night through very early Tuesday evening, will keep
chance PoPs going across the SSE 1/3 or so of the area, with
essentially dry conditions to the north and west of the Ohio. As far
as precip type. Again given low confidence in the track and
evolution of the system, and also accounting for the impact the
arctic airmass may have on the area, will keep it R--/S--.
Additional adjustments will probably be required once the models can
resolve whether or not the southern stream system will remain its
own entity, or if there will be some kind of phasing aspect.
The forecast Wednesday through Saturday still looks dry. Another
blast of cold high pressure will develop and move southeast across
the east 1/2 of the CONUS. Temperatures will remain below normal.
&&
.AVIATION...
ISSUED AT 1055 AM CST SAT NOV 23 2013
Considerable high cloud cover continued to stream across the area.
NNW winds will persist through the afternoon, gusty at times
(15-20kt). Main challenge will be with strato-cu over the nrn 1/2
of IL. The RAP seems to handle this best, per 950-900mb layer rh
progs. Other models seem too dry. Will follow the RAP, and place a
hedge SCT deck near 3k/ft in, and leave it, since the RAP holds on
to the low level moisture all the way through 06z. Steady north
winds near 10 kts expected tonight.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...KH
LONG TERM...CN
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1055 AM CST Sat Nov 23 2013
.UPDATE...
ISSUED AT 1055 AM CST SAT NOV 23 2013
Updated the AVIATION section.
&&
.SHORT TERM...(Today through Monday)
ISSUED AT 1246 AM CST SAT NOV 23 2013
Clouds will gradually disperse later today as satellite trends
become more entrenched. Cold day today still on tap with highs in
the upper 30s-mid 40s prevailing. Sat night still offers coldest
air with clear out and lows making their way into the teens.
High pressure settling across the PAH FA allows a brief warmup
Sunday as moisture increases from the west again. Pcpn chances
will ramp up by
.LONG TERM...(Monday Night through Friday)
ISSUED AT 215 AM CST SAT NOV 23 2013
Main long term forecast concern is the potential for a little wet
snow Monday night and Tuesday. Models are in good agreement that a
split flow pattern will exist Monday night and Tuesday. Our precip
potential will come from the southern stream system...which will
primarily affect the Gulf Coast states. The consensus solution of
the 00z model suite brings the northern fringe of measurable qpf up
to about the Ohio River. Looking at the thermal profiles from the
00z nam and 03z sref mean...the column would be almost entirely
below freezing except for the boundary layer. Therefore...precip
type should be mainly snow. Given that surface temps will be above
freezing and precip will be light...no impacts are anticipated on
travel. Precip type could be rain at times since boundary layer
temps will be just above freezing. Pops will be kept in the chance
category over southwest KY...and a dry forecast will continue in
most of southern IL and southeast MO.
Phasing of the northern and southern stream systems will occur to
our east on Wednesday...creating a rather strong East Coast storm.
This system will bring another shot of unseasonably cold air
southward across the mid section of the nation. 850 mb temps will
again fall to around minus 10...similar to the air mass that is
enveloping our region this weekend. Highs Wednesday will likely be
in the 30s in most places.
Looking to Thanksgiving and Friday...the upper level flow pattern
will become less amplified as the East Coast system exits to the
east. Temps will slowly moderate...possibly reaching seasonal norms
by the weekend. Dry conditions are expected for the holiday itself
and Friday.
&&
.AVIATION...
ISSUED AT 1055 AM CST SAT NOV 23 2013
Considerable high cloud cover continued to stream across the area.
NNW winds will persist through the afternoon, gusty at times
(15-20kt). Main challenge will be with strato-cu over the nrn 1/2
of IL. The RAP seems to handle this best, per 950-900mb layer rh
progs. Other models seem too dry. Will follow the RAP, and place a
hedge SCT deck near 3k/ft in, and leave it, since the RAP holds on
to the low level moisture all the way through 06z. Steady north
winds near 10 kts expected tonight.
..CN..
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
545 PM EST SAT NOV 23 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT WITH A STRONG NORTHWEST
FLOW SETTING UP BEHIND IT. HIGH PRESSURE WILL BUILD SOUTH OF NEW
ENGLAND SUNDAY THROUGH MONDAY. A COLD FRONT WILL SLOWLY APPROACH
FROM THE WEST MONDAY NIGHT AND TUESDAY AND WILL CROSS THE REGION
TUESDAY NIGHT. LOW PRESSURE WILL MOVE UP THE EAST COAST ON
WEDNESDAY. HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST
THURSDAY THROUGH FRIDAY. HIGH PRESSURE WILL CREST OVER THE REGION
ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
UPDATE...ARCTIC COLD FNT MAKING QUICK PROGRESS TOWARDS THE CWFA
ATTM. SHSN AND SQUALLS WILL BECOME MORE NUMEROUS AS IT APPROACHES
THIS EVENING. STRONG CAA IS DESTABILIZING THE LLVLS...ALLOWING
SHSN TO BECOME QUITE INTENSE AT TIMES. LOOKING AT UPSTREAM OBS AND
WEBCAMS...VSBYS WILL DROP TO 1/4SM OR LESS AT TIMES. HAVE ADDED
HEAVY SN WORDING TO SRN NH AND ADJACENT SWRN ME FOR THE NEXT
SEVERAL HOURS AS SQUALLS TRACK OVER THESE AREAS.
ADDITIONALLY...ABOVE FREEZING TEMPS TODAY WILL MEAN ROAD TEMPS
WILL BE WARM ENOUGH TO MELT SNFL INITIALLY. HOWEVER...RAPIDLY
FALLING TEMPS WILL MEAN THIS WILL REFREEZE...CREATING VERY ICY
ROADWAYS. SEEING AS THESE SHSN WILL BE CROSSING INTERSTATES
89...93...AND 95 THIS IS A CONCERN. USED A BLEND OF THE LATEST RAP
AND HRRR TO TREND POP OVER THE NEXT FEW HOURS. OTHERWISE FORECAST
LOOKS ON TRACK AS BITTER COLD HEADS TOWARDS THE REGION.
PREVIOUS DISCUSSION...AN ARCTIC COLD FRONT WILL BE MOVING THROUGH
LATE TONIGHT. WINDS WILL BE DROPPING OFF SOMEWHAT AND TURNING MORE
TO THE SW AHEAD OF THE FRONT THIS AFTERNOON AND THIS EVENING. ONCE
THE FRONT MOVES THROUGH WINDS WILL STIFFEN FROM THE NW. THERE IS
SOME INDICATION THAT A BAND OF SNOW WILL MOVE THROUGH SRN NH AND
SW MAINE AROUND MIDNIGHT. THIS BAND CAN BE SEEN ON RADAR MOVING
THROUGH THE ADIRONDACKS ATTM.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
FOR SUNDAY WE HAVE ISSUED A WIND ADVISORY. LOOKING AT BUFKIT DATA
SHOWS WINDS TO 40 TO 50 KTS DOWN TO 2K FEET WITH STEEP LAPSE
RATES. THE STRONGEST WINDS ARE LIKELY TO BE IN THE 18Z TO 03Z TIME
FRAME. WINDS GUSTS TO 45 TO 50 MPH ARE CERTAINLY POSSIBLE. EXPECT
THERE WILL BE POWER OUTAGES AS THE DAY GOES ON. TEMPERATURES WILL
RISE ABOUT 5 TO 10 DEGREES TOMORROW WHICH WILL PUT HIGH TEMPS IN
THE 20S MOST EVERYWHERE WITH SOME UPPER TEENS IN THE MOUNTAINS.
THIS IS A GOOD 20 DEGREES BELOW NORMAL. SNOW SHOWERS WILL BE
LIKELY IN THE MOUNTAINS WITH 1 TO 3 INCHES POSSIBLE. FOR SUNDAY
NIGHT WINDS WILL ABATE SOMEWHAT AFTER MIDNIGHT BUT TEMPS WILL
PLUNGE. EXPECT AROUND ZERO IN THE MOUNTAINS AND NEAR 10 AT THE
COAST. RECORD LOW FOR PORTLAND MONDAY IS 9 DEGREES. WILL BE CLOSE
TO THIS.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
RIDGE OF HIGH PRESSURE WILL CREST OVER THE REGION MONDAY BEFORE
SHIFTING OFFSHORE. EXPECT A SUNNY START TO THE DAY BEFORE HIGH
CLOUDS SPILL IN FROM THE WEST IN THE AFTERNOON. WILL BE ANOTHER COLD
ONE WITH HIGHS ONLY REACHING THE UPPER TEENS TO LOWER 20S NORTH AND
MID 20S TO NEAR 30 SOUTH.
AREA OF WEAK OVER-RUNNING AHEAD LOW PRESSURE MOVING THROUGH SOUTHERN
CANADA WILL PUSH IN FROM THE WEST MONDAY NIGHT BRINGING SOME LIGHT
SNOW TO THE REGION. BEST CHANCES OF PRECIP WILL BE IN NORTHERN ZONES
WHERE AN INCH OR TWO OF ACCUMULATION WILL BE POSSIBLE. ELSEWHERE
JUST LOOKING FOR A LIGHT DUSTING. LOOKING FOR LOWS IN THE MID TEENS
TO LOWER 20S.
CLOUDS AND LINGERING FLURRIES WILL GIVE WAY TO PARTLY SUNNY SKIES ON
TUESDAY. COLD FRONT APPROACHING FROM THE WEST MAY BRING SNOW SHOWERS
TO THE MOUNTAINS BY LATE IN THE DAY. SHOULD SEE A MUCH WARMER DAY
WITH TEMPS RANGING THROUGH THE 30S.
COLD FRONT WILL SWING THROUGH THE REGION TUESDAY NIGHT BRINGING A
CHANCE OF SNOW SHOWERS IN THE NORTH AND VARIABLE CLOUDS ACROSS
SOUTHERN AREAS. OVERNIGHT LOWS WILL RANGE THROUGH THE 20S.
MODELS STILL FAR APART ON WEDNESDAY WITH THE ECMWF BRINGING LOW
PRESSURE UP THE EAST COAST AND GFS TAKING THE SAME SYSTEM WELL
OFFSHORE. AT THIS POINT SUPER BLEND GIVING LIKELY POPS WITH A MIX OF
RAIN AND SNOW IN THE SOUTH AND SNOW IN THE FOOTHILLS AND NORTH. SO
POTENTIAL IS STILL THERE FOR SIGNIFICANT SNOW IN THE NORTH AND A
MESSY MIX IN THE SOUTH. HIGH TEMPS WILL RANGE THOUGH THE 30S TO
NEAR 40.
HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST THURSDAY
THROUGH FRIDAY. EXPECT TEMPS ONCE AGAIN BELOW NORMAL THURSDAY AS
COLD CANADIAN AIR FLOODS IN ON A STRONG NORTHERLY WINDS. WILL SEE
TEMPS MODERATE SOMEWHAT ON FRIDAY AS HIGH PRESSURE CRESTS OVER THE
REGION.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...EXPECT MOSTLY VFR. BRIEF MVFR/IFR PSBL LATE TONIGHT
IN SNOW SHOWERS. HIE WILL SEE MOSTLY MVFR.
LONG TERM...VFR MONDAY THROUGH TUESDAY. IFR/LIFR CEILINGS AND VSBY
DEVELOPING ON WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
SHORT TERM...GALE WARNING HAS BEEN ISSUED.
LONG TERM...GALES POSSIBLE ON WEDNESDAY.
&&
.CLIMATE...
SIGNIFICANT OUTBREAK OF EARLY SEASON COLD AIR WILL CHALLENGE SOME
LOCAL RECORDS OVER THE NEXT COUPLE OF DAYS. AT KPWM THE RECORD
COLD MAXIMUM TEMP FOR 11/24 IS 28 SET IN 1989. THE TEMP AROUND
MIDNIGHT TONIGHT WILL LIKELY BE THE WARMEST KPWM GETS ALL
DAY...AND WILL BE VERY CLOSE TO 28 DEG. ON 11/25 KPWM HAS A RECORD
COLD MAXIMUM TEMP OF 29 SET IN 1993. THE CURRENT FORECAST IS FOR A
HIGH TEMP AROUND 30. FOR LOW TEMP ON 11/25...KPWM SET A RECORD IN
2000 OF 9 DEG. THE CURRENT FORECAST IS FOR 11/25 IS A LOW TEMP
AROUND 10 DEG.
SIMILARLY FOR KCON...RECORD COLD MAXIMUM TEMP FOR 11/24 IS 27 SET
IN 2000. WHILE IN 1993 THE RECORD COLD MAXIMUM TEMP WAS SET AT 29.
THE RECORD LOW TEMP FOR 11/25 IS 5 DEG SET IN 1956 AND 2000.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WIND ADVISORY FROM 7 AM SUNDAY TO 1 AM EST MONDAY FOR
MEZ007>009-012>014-018>028.
NH...WIND ADVISORY FROM 7 AM SUNDAY TO 1 AM EST MONDAY FOR
NHZ001>010-013-014.
MARINE...GALE WARNING FROM 7 AM SUNDAY TO 7 AM EST MONDAY FOR
ANZ150>154.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1112 AM CST Sat Nov 23 2013
.SHORT TERM...(Today and Tonight)
Issued at 346 AM CST SAT NOV 23 2013
Regional radar indicates a few echoes of light precipitation over
eastern Kansas. At this time expect those echoes to represent some
mid to high based precipitation, occurring at roughly 10 to 12 kft,
where RAP soundings indicate the lowest level of saturation. Below
that level, soundings indicate very dry air, which will preclude any
of the precipitation from reaching the surface.
The cold weather will continue across the area through the rest of
the weekend as cold northerly air continues to filter into the
Central Plains. The major culprit for this abnormally cold period is
an incredibly anomalous surface ridge located right on the Canadian
border with North Dakota. Currently, observations in far southern
Canada indicated roughly 1050 mb for the surface ridge and
temperatures in the -15 to -20 range. This ridge will slide
south/southeast and become centered over northern Missouri late
Saturday night into early Sunday morning. NAM has the surface ridge
approaching 1050 mb even as it becomes centered over the KC Metro
Sunday morning. Should the ridge maintain 1045 to 1050 mb as it
moves into the KC Metro its anomaly would carry nearly 4 standard
deviations from the seasonal normal, an incredible value.
Ahead of this ridge, cold air will continue to move into northern
and central Missouri causing temperatures on Saturday to remain
extremely chilly, with highs generally remaining in the lower to
middle 20s along and north of Interstate 70, with perhaps a few
areas south of Interstate 70 reaching the lower 30s.
As the aforementioned ridge moves overhead Saturday night the skies
will clear and winds will go calm, providing an incredible
opportunity for the surface to radiate outward. The result will be
record - or at the very least - near record temperatures for Sunday
morning across all of eastern Kansas and northern/central Missouri.
Even though the source region of this ridge demonstrates
temperatures well below 0 the lack of snow cover across areas north
of the forecast area will allow the airmass to modify. At this time
we can expect temperatures along and north of Interstate 70 to be in
the single digits - near zero degrees - Sunday morning, with areas
along Interstate 70 being near 10 degrees, and areas south of the
interstate being in the 10 to 15 degree range (See Climate portion
of the AFD for record lows for 11/24 in the KC Metro and St.
Joseph). Wind chills for Sunday morning will closely resemble the
morning lows, since the ridge being parked overhead will generally
prevent much in the way of surface flow, but ironically the coldest
wind chills Sunday morning could occur south of Interstate 70 where
light easterly winds in combination with the cold temperatures could
bring wind chill values to near zero. Only a modest diurnal warming
can be expected for Sunday as sunshine and perhaps the beginning of
southerly return flow could aid in getting the temperatures back
near the middle 30s by Sunday afternoon.
Very little - if any - relief from the cold temperatures are
expected through the early part of next week. In fact, after
Monday`s "warming" trend back into the lower 40s, expect another
cold front to blast through the area pulling temperatures back into
the 20s and 30s for Tuesday. At this time will continue a dry
forecast into the early part of the week, but there is a hint that
there could be some extremely light snowfall on Sunday night into
Monday morning. Southerly return flow late Sunday could usher a very
tiny amount of low level moisture into the area and spread it over
the aforementioned very cold surface temperatures. With a southern
stream cutoff low over the 4 Corner region, and a northern stream
long wave trough gently sagging southward into the area there could
be some ascent interaction with the moisture, however at this point
it was very difficult to even find modest lift. So, as previously
mentioned, have gone with a dry forecast for Sunday night, but
upcoming shifts will need to monitor the chances for very light,
likely non-accumulating, snow for Sunday night into Monday morning.
.LONG TERM...(Sunday through Friday)
Issued at 346 AM CST SAT NOV 23 2013
For Tuesday, and through the rest of the week, cool and dry
conditions are expected to prevail. Medium range operational and
ensemble models all point at Tuesday arriving with a trough swinging
through the center of the nation. Below the base of the trough a
cutoff low --currently noted spinning over Southern California--
will be phasing with the larger synoptic trough. Models continue to
show strong agreement that the cutoff low, even as it phases into
the base of trough, will stay south of Kansas and Missouri as it
transits the nation, thus allowing still more cold dry Canadian air
to slip south into the Plains States as a northwest flow prevails.
However, by late in the work week Tuesdays prevailing trough will
have pivoted fare to our east, and with another shortwave trough
expected to drop into the West Coast the flow across the center of
the nation should transit to more of a zonal flow across the Plains,
thus allowing a little moderation in our temperatures for the tail
end of the week. Thus, at this time, dry weather is expected, with
highs in the 30s prevailing Tuesday and Wednesday, creeping into the
40s for Friday and Saturday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1110 AM CST SAT NOV 23 2013
VFR conditions expected through the period. Wind speeds will greatly
decrease post-sunset, likely becoming variable as the surface high
shifts over the area. Southeasterly winds will return after sunrise
as the sfc high moves east.
&&
.CLIMATE...
Issued at 346 AM CST SAT NOV 23 2013
Record lows for November 24...
Value Date
Kansas City 9 11/24/1950
St. Joseph 9 11/24/1950
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Leighton
LONG TERM...Cutter
AVIATION...Blair
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1203 PM EST SAT NOV 23 2013
.SYNOPSIS... A COLD FRONT WILL CONTINUE TO DROP SOUTH ACROSS THE
CAROLINAS TODAY WITH A REINFORCING COLD FRONT TO FOLLOW TONIGHT AS
COLD HIGH PRESSURE BUILDS IN FOR THE REMAINDER OF THE WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 940 AM SATURDAY...
OVERVIEW: POTENT SHORTWAVE ENERGY OVER THE UPPER MIDWEST AT 08Z THIS
MORNING WILL DIG SOUTHEAST THROUGH THE OH VALLEY THIS AFTERNOON...
AMPLIFYING AN UPPER LEVEL TROUGH AS IT PROGRESSES TOWARD THE MID-
ATLANTIC COAST TONIGHT. IN THE LOWER LEVELS...A COLD FRONT EXTENDING
FROM CENTRAL GA NORTHEAST THROUGH CENTRAL NC AND SOUTHEAST VA AT 08Z
WILL PROGRESS SOUTHEAST TO THE COAST THIS MORNING...FOLLOWED BY A
STRONGER REINFORCING COLD FRONT THIS EVENING...THE LEADING EDGE OF
AN ARCTIC AIRMASS (1045-1050 MB SFC HIGH IN THE CENTRAL CONUS)
BUILDING INTO THE REGION OVERNIGHT. -VINCENT
AS OF 12Z THIS MORNING THE COLD FRONT WAS DRAPED ACROSS CENTRAL
NORTH CAROLINA WHERE IT WAS BEGINNING TO STALL OUT. VISIBLE
SATELLITE IMAGERY HAD SHOWN A DISTINCT BOUNDARY WITH THE TRIAD
CLEARING OUT FOR A TIME EARLIER THIS MORNING BUT SINCE THEN CLOUDS
HAVE BEGUN TO BACK BUILD OVER THE TRIANGLE AREA AND NEW CLOUD COVER
HAS ADVECTED INTO THE TRIAD FROM THE WEST. AS A RESULT...EXPECT HIGH
TEMPERATURES TODAY TO BE ABOUT WHAT THEY ARE NOW WITH MAYBE SOME
SLIGHT INCREASES TO THE CURRENT OBSERVED TEMPERATURES. AS FAR AS
PRECIPITATION GOES...IT SHOULD REMAIN LIGHT IN THE FRONTAL ZONE AND
POINTS SOUTH AND EAST WITH TOTALS A COUPLE HUNDREDTHS OF AN INCH OR
LESS. LATER THIS MORNING AND INTO THE AFTERNOON COLD AIR ADVECTION
SHOULD TAKE OVER DROPPING TEMPERATURES IN THE NORTHERN HALF OF THE
CWA WITH CLOUD COVER TO THE SOUTH KEEPING TEMPERATURES DOWN THERE AS
WELL. WITH THE ONSET OF COLD AIR ADVECTION WE SHOULD SEE A DECREASE
IN DEWPOINTS AS WELL AS AN INCREASE IN THE WIND GUSTS...UP TO 15
KNOTS OR SO AND THIS HAS ALREADY BEGUN TO OCCUR IN THE TRIAD.
FOR THIS AFTERNOON BOTH THE RAP AND THE NAM ARE DEPICTING A FAIRLY
WELL DEFINED 500 MB VORT MAX THAT WILL RUN ALONG THE FRONT AND
PROVIDE SOME EXTRA FORCING FOR SOME SPRINKLES TO LIGHT RAIN ACROSS
THE SOUTHERN HALF OF THE CWA. HAVE INCREASED POPS TO CHANCE IN THE
SOUTH AROUND 18Z AND THEN QUICKLY TAPERING OFF AFTER DARK.
THE SURFACE HIGH WILL CONTINUE TO BUILD IN FROM THE NORTHWEST
TONIGHT AND A REINFORCING DRY COLD FRONT WILL HELP SKIES CLEAR FORM
NORTH TO SOUTH. COMBINED COLD AIR ADVECTION AND CLEARING WILL HELP
TEMPERATURES DROP INTO THE MIDDLE 20S FOR LOWS IN THE TRIAD WITH
UPPER 20S TO LOW 30S ELSEWHERE.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 325 AM SATURDAY...
STRONG ARCTIC HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION
ON SUNDAY...BECOMING CENTERED OVER THE AREA SUNDAY NIGHT. WITH COLD
ADVECTION PERSISTING THROUGH MUCH OF THE DAY...1000-850 MB
THICKNESSES BETWEEN 1265-1275 METERS IN THE AFTERNOON...AND H85
TEMPS RANGING FROM -10C (S) TO -13C (N)...EXPECT TEMPERATURES TO
STRUGGLE OUT OF THE 30S IN MOST LOCATIONS...AND WILL INDICATE HIGHS
RANGING FROM JUST ABOVE FREEZING (~34F) IN THE NW TO NEAR 40F IN THE
FAR S/SE. WITH A COLD/DRY ARCTIC AIRMASS SETTLING OVERHEAD SUN
NIGHT...EXPECT OPTIMAL RADIATIONAL COOLING AND LOWS IN THE TEENS TO
LOWER 20S...COLDEST IN RURAL AND LOW-LYING AREAS. -VINCENT
&&
.LONG TERM /MONDAY THOUGH FRIDAY/...
AS OF 222 AM SATURDAY...
...A GOOD SOAKING RAIN TUE-WED...
...PRECIPITATION MAY BEGIN AS A BRIEF WINTRY MIX IN THE NW PIEDMONT
IF THE PRECIPITATION BEGINS BEFORE 12Z TUESDAY...
THE CORE OF THE ARCTIC AIR MASS WILL BE LOCATED OVER THE REGION AT
12Z MONDAY. HIGH PRESSURE WILL GRADUALLY SHIFT OFFSHORE MONDAY
NIGHT. MODELS ARE IN EXCELLENT AGREEMENT WITH THE PARENT HIGH
PRESSURE MOVING OFFSHORE MONDAY NIGHT (VERY CRITICAL TO THIS
FORECAST). THIS TO BE FOLLOWED BY A RAPID INCREASE IN MID AND UPPER
LEVEL MOISTURE MONDAY NIGHT. THEREFORE... A CONTINUED MOSTLY SUNNY
DAY IS FORECAST MONDAY WITH HIGHS 40-45. INCREASING CLOUDINESS
MONDAY NIGHT WITH LOWS 30-35.
A SIGNIFICANT MID/UPPER LEVEL LOW PRESSURE IS FORECAST TO EJECT OUT
OF TEXAS TUESDAY MORNING... THEN TRACK EAST ALONG THE GULF COAST AND
ACROSS THE SOUTHEASTERN STATES TUESDAY THROUGH WEDNESDAY. RECENT
DETERMINISTIC MODELS HAVE BEEN FORECASTING A COUPLE OF STRUNG OUT
WEAK LOW PRESSURE CENTERS TO TRACK FROM THE N-NE GULF OF MEXICO
ALONG THE CAROLINA COAST TUE-WED. THIS IS IMPORTANT IN THAT THERE
APPEARS TO BE LITTLE PHASING OF THE POLAR JET WITH THIS SOUTHERN
BRANCH SYSTEM UNTIL THE SYSTEM IS PAST OUR LATITUDE AND OFFSHORE
LATE WED... KEEPING THE SURFACE SYSTEM(S) WEAK AND STRUNG OUT
INSTEAD OF ONE STRONG LOW PRESSURE. REGARDLESS... THIS STILL APPEARS
TO BE A GOOD RAINFALL PRODUCER FOR OUR REGION. MANY AREAS HAVE HAD
LESS THAN 25 PERCENT OF THE AVERAGE RAINFALL SINCE SEPTEMBER.
AS FOR PRECIPITATION TYPE (P-TYPE)... CONFIDENCE CONTINUES HIGH IN
THAT RAIN WILL BE PREDOMINATE P-TYPE DUE TO THE RAPIDLY DEVELOPING
PROMINENT WARM NOSE ALOFT. HOWEVER IN THE WESTERN AND NORTHERN
PIEDMONT ZONES SOME LIGHT SNOW/SLEET/FREEZING RAIN MAY FALL AT THE
ONSET DEPENDING ON TIMING. IF THE PRECIPITATION DEVELOPS EARLY
ENOUGH (BEFORE 15Z)... THERE MAY BE SOME NUISANCE LIGHT SNOW/SLEET
(12Z) BEFORE A QUICK CHANGE TO LIGHT FREEZING RAIN/RAIN THEN ALL
RAIN BY 15Z. THE MAJORITY OF ENSEMBLE FORECASTS INDICATE STRONG WAA
JUST ABOVE THE BOUNDARY LAYER TAKING THE 1000/850 AND 850/700
PARTIAL THICKNESSES WELL INTO THE HISTORICALLY "ALL RAIN" CATEGORY
RATHER QUICKLY TUESDAY.
THE AMOUNT OF VERY DRY AIR IN PLACE BEFORE MOISTENING TUESDAY
MORNING APPEARS SUBSTANTIAL... WITH DEW POINTS FORECAST IN THE 15-20
RANGE AROUND 12Z IN THE PIEDMONT. PARTIALS IN THE 1295-1305 / 1550
RANGE RAPIDLY WARM WITH TIME...SUGGESTING A POSSIBLE LIGHT
FROZEN/FREEZING EVENT IN THE NW (TRACE AMOUNTS) QUICKLY CHANGING TO
RAIN. THE SURFACE WET BULB FORECASTS QUICKLY MODIFY AFTER
DAYBREAK... REACHING THE LOWER 30S BY MIDDAY AND MID 30S BY EVENING.
GIVEN THAT THERE WILL BE PLENTY OF EVAPORATION AT THE LEADING EDGE
OF THE PRECIPITATION SHIELD... SUGGESTING THAT ANYTHING THAT REACHES
THE SURFACE WILL BE VERY LIGHT THROUGH THE CRITICAL PERIOD (10Z-
13Z). THEREFORE... WE WILL MAINTAIN THE "ALL RAIN" FORECAST FOR NOW
GIVEN THE UNCERTAINTY OF TIMING OF ARRIVAL OF THE PRECIPITATION
NOTING THAT ANYTHING OTHER THAN RAIN WOULD MOST LIKELY BE OF
NUISANCE.
THE LATEST OPERATIONAL EUROPEAN CONTINUES TO BE QUICK AND ROBUST
WITH DEVELOPING/SPREADING PRECIPITATION NE ACROSS WESTERN NC BETWEEN
06Z AND 12Z TUESDAY. EVEN THE LATEST NAM A FEW ENSEMBLE MEMBERS ARE
THIS AGGRESSIVE... WITH AS MUCH AS 0.25 OF QPF BY 12Z IN THE HKY TO
INT AREAS. IF THIS WERE TO OCCUR... THE SOUNDINGS INDICATE RAPIDLY
WARMING MID LEVELS BETWEEN 06Z/12Z TUESDAY... BECOMING A PROMINENT
WARM NOSE ALOFT AS EARLY AS 18Z. THE NEAR SURFACE LAYER MAY BE VERY
CLOSE TO OR SLIGHTLY BELOW FREEZING FOR A COUPLE OF HOURS CENTERED
AROUND 12Z. THEREFORE... THE CURRENT WORST CASE SCENARIO WOULD BE
FOR SOME LIGHT SNOW AND SLEET TO DEVELOP BEFORE SUNRISE... QUICKLY
BECOMING LIGHT FREEZING RAIN AROUND 12Z... THEN RAIN BY 15Z AS
WARMING ALOFT AND HEAVIER RAIN WARMS THE COLUMN FROM THE TOP DOWN.
THIS WOULD BE THE ONE CAVEAT... IF THE LATEST EC AND SOME ENSEMBLE
MEMBERS PROVE CORRECT IN THE QUICKER ARRIVAL OF LIGHT PRECIPITATION
BEFORE OR AROUND DAYBREAK... THEN MORE IN THE WAY OF SOME LIGHT
FREEZING RAIN OR EVEN SOME BRIEF LIGHT FROZEN HYDROMETERS MAY FALL
IN THE NW.
SENSIBLE WEATHER THEN... PREDOMINATELY COLD RAIN IS EXPECTED TUESDAY
INTO TUESDAY NIGHT... WITH PERIODS OF RAIN EVEN INTO WEDNESDAY AS
THE MID/UPPER LOW FOLLOW... AND TRACK ACROSS THE REGION WEDNESDAY.
PARTIAL THICKNESSES SUPPORT A BRIEF MIX OR CHANGE TO LIGHT SNOW
(LITTLE ACCUMULATION EXPECTED CURRENTLY) BEFORE ENDING IN THE NW AND
N PIEDMONT BETWEEN 18Z AND 23Z WED.
IF THE 1-2 INCH QPF OF RAINFALL WORKS OUT BEFORE HAND... AND WITH
TEMPS WELL ABOVE 35 WED AFTERNOON... IT WOULD HAVE TO SNOW HEAVILY
TO ACCUMULATE. THIS IS NOT ANTICIPATED AT THIS TIME.
CLEARING IS EXPECTED WEDNESDAY NIGHT AND DRY COLD CONDITIONS CAN BE
EXPECTED THANKSGIVING DAY AND FRIDAY. LOWS IN THE LOWER TO MID 20S.
HIGHS IN THE LOWER TO MID 40S (15-20 DEGREES BELOW NORMAL).
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1200 PM SATURDAY...
24 HOUR TAF PERIOD: VFR CONDITIONS SHOULD PREVAIL AT MOST LOCATIONS
THROUGH THE TAF PERIOD WITH THE EXCEPTION OF KFAY WHICH MIGHT SEE A
BRIEF DROP TO MVFR THIS AFTERNOON WITH SOME LIGHT RAIN ASSOCIATED
WITH A SHORTWAVE MOVING THROUGH THE CHARLOTTE AREA AT THIS TIME.
OTHERWISE NORTHWESTERLY FLOW THIS AFTERNOON AT 5-10 KNOTS WITH THE
OCCASIONAL GUST TO 15 KNOTS THROUGH SUNSET. OVERNIGHT TONIGHT A
REINFORCING COLD FRONT WILL COME THROUGH AND ALTHOUGH IT WILL BE
DRY...THE WINDS WILL PICK UP CONSIDERABLY AFTER 4Z IN THE TRIAD AND
AFTER 6Z ELSEWHERE. WINDS WILL BE NORTHERLY. EXPECT 10-15 KNOTS
SUSTAINED GUSTING UPWARDS OF 25 KTS FROM 6Z THROUGH THE END OF THE
TAF PERIOD. EXPECT SKIES TO CLEAR OUT ONCE THE SECONDARY FRONT
PASSES THROUGH AS THE SURFACE HIGH BUILDS INTO THE AREA.
LONG TERM: A FAIRLY POTENT STORM SYSTEM WILL MOVE INTO THE AREA FROM
THE SOUTHWEST ON TUESDAY NIGHT INTO WEDNESDAY...FOLLOWED BY A
SECONDARY LOW WEDNESDAY NIGHT INTO THURSDAY. BOTH LOWS ARE PROGGED
TO TRACK OFF THE COAST AT THIS TIME. WHILE SEVERE WX SHOULD NOT BE A
THREAT...AN EXTENDED PERIOD OF MODERATE RAIN WITH ADVERSE AVIATION
CONDITIONS WILL BE PROBABLE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ELLIS
NEAR TERM...VINCENT/ELLIS
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1210 PM CST SAT NOV 23 2013
.AVIATION...DISCUSSION FOR 18Z TAFS
FLYING CONDITIONS WILL GENERALLY DETERIORATE THROUGH THE NEXT 12-18
HOURS AS PRECIP CHANCES INCREASE AND CIGS/VSBYS DECREASE. THOUGH
KAMA AND POSSIBLY KDHT COULD BE AFFECTED BY SOME LIGHT SLEET OR SNOW
OVER THE NEXT FEW HOURS...THE MAIN CONCERN WILL BE LATER TONIGHT AS A
MORE INTENSE SNOW BAND WORKS THROUGH THE AREA FROM SW TO NE. HAVE
TIMED OUT BEST CHANCES FOR THIS BAND...BUT TEMPO GROUPS WILL LIKELY
BE NEEDED LATER. WE COULD SEE A LITTLE FREEZING DRIZZLE SUN
MORNING...BUT REFRAINED FROM INCLUDING THIS IN THE TAFS AT THIS TIME
AS IT SHOULD BE PRETTY PATCHY. CIGS WILL BE SLOW TO INCREASE ON
SUN...LIKELY STAYING IFR OR LOW END MVFR THROUGH 18Z.
SIMPSON
&&
.PREV DISCUSSION... /ISSUED 736 AM CST SAT NOV 23 2013/
UPDATE...
LATEST HRRR...TTU-WRF...RUC...NAM AND GFS ALL STILL SHOWING DRIER
WORKING NORTHEAST TO SOUTHWEST ACROSS THE PANHANDLES DURING THE DAY
TODAY WITH A DECREASE IN THE PRECIP. HOWEVER...MODELS NOT PICKING UP
ON PRECIP LIFTING NORTHEAST OUT OF NM AND ERRING ON THE SIDE OF
CAUTION AS ROADS AND HIGHWAYS REMAIN SLICK AND ICY FROM FREEZING RAIN
AND FREEZING DRIZZLE LAST NIGHT. PRECIP COMING OUT OF NM MAY CREATE
ANOTHER ROUND OF FREEZING RAIN...FREEZING DRIZZLE OR SLEET ADDING TO
THE ICY CONDITIONS. DECIDED TO TO ISSUE A WINTER WEATHER ADVISORY
FOR WINTRY PRECIP THROUGH 12Z MONDAY DUE TO THE UNCERTAINITES AND LOW
CONFIDENCE IN THE SHORT RANGE AND HIGH RES MODELS.
UPDATED PUBLIC PRODUCTS HAVE BEEN ISSUED.
SCHNEIDER
PREV DISCUSSION... /ISSUED 522 AM CST SAT NOV 23 2013/
UPDATE...
MOST OF THE PRECIPITATION HAS LEFT THE AREA...THUS THE WINTER WEATHER
WILL BE ALLOWED TO EXPIRE AT THE TOP OF THE HOUR. HOWEVER...ICY ROADS
REMAIN IN THE PANHANDLES...THUS WILL ISSUE AN SPS TO COVER THE SLICK
CONDITIONS THAT WILL REMAIN FOR AT LEAST THE MORNING HOURS.
JOHNSON
AVIATION...
FOR THE 12Z TAFS...CONDITIONS WILL CONTINUE TO IMPROVE THROUGH THE
MORNING HOURS...WITH VFR CONDITIONS EXPECTED AT ALL THREE TAF SITES
FROM 18 TO 00Z. AFTER 00Z...MOISTURE FROM THE NEXT SYSTEM WILL BEGIN
TO STREAM INTO THE REGION...BRINGING LOWER CEILINGS...BR...AND
EVENTUALLY SN. AS WITH YESTERDAY...TEMPERATURES WILL REMAIN BELOW OR
NEAR FREEZING ALL DAY...THUS ANY BR THAT DEVELOPS CARRIES THE ADDED
THREAT OF ICING.
JOHNSON
PREV DISCUSSION... /ISSUED 409 AM CST SAT NOV 23 2013/
DISCUSSION...
CLOSED UPPER LOW OVER SOUTHERN CALIFORNIA AND NORTHERN BAJA WILL
BEGIN TO EJECT SLOWLY EAST TODAY...MOVING ACROSS THE SOUTHWESTERN
STATES BY 12Z SUNDAY...AND THEN ACROSS THE SOUTHERN ROCKIES SUNDAY
NIGHT. SHORTWAVE RIDGE AHEAD OF THE UPPER LOW WILL REMAIN OVER THE
FORECAST AREA TODAY AND THEN WILL SHIFT EAST AWAY FROM THE PANHANDLES
SUNDAY. ANY WINTRY PRECIPITATION TODAY WILL BE RATHER LIGHT AND LOW
CONFIDENCE PREVAILS ON PRECIP TYPE. FREEZING DRIZZLE AND LIGHT
FREEZING RAIN HAS ALREADY GLAZED ROADS AND HIGHWAYS IN THE FORECAST
AREA SINCE ABOUT 05Z TO 10Z SATURDAY BUT MOVING NORTHEAST OUT OF THE
FORECAST AREA. THE LATEST HRRR SHOWING DRYING TREND THROUGH THE DAY
TODAY UNTIL THE NEXT ROUND OF PRECIP MOVES INTO THE PANHANDLES AFTER
00Z SUNDAY. WILL HOLD OFF ON ANY ADVISORIES...WATCHES OR WARNINGS
TODAY AS THE CURRENT WINTER WEATHER ADVISORY SET TO EXPIRE AT 12Z
TODAY. BEST CHANCES FOR ANOTHER ROUND OF FREEZING AND OR FROZEN
PRECIPITATION...MAINLY SNOW AND SLEET...WILL OCCUR TONIGHT THROUGH
SUNDAY AND SUNDAY NIGHT AS THE LEADING SHORTWAVE ASSOCIATED WITH THE
UPPER LOW TRACKS EAST OUT OF THE FOUR CORNERS REGION AND SOUTHERN
ROCKIES BY 06Z SUNDAY WITH THE MAIN SHORTWAVE AFFECTING THE
PANHANDLES BY 00Z MONDAY. NAM STILL OVERLY BULLISH ON POPS AND QPF
WHILE THE GFS AND ECMWF DIFFER ON TIMING AND TRACK OF THE UPPER LOW.
THE GFS IS FASTER THAN THE ECMWF AND FURTHER SOUTH WITH THE CLOSED
UPPER LOW. LOW CONFIDENCE IN THE MEDIUM RANGE MODELS BUT LEAN TOWARD
THE ECMWF SOLUTION.
BOTH THE ECMWF AND GFS SHUTTING OFF THE PRECIP BY LATE MONDAY AS THE
CLOSED UPPER LOW DIGS SOUTH OF THE PANHANDLES BY 00Z TUESDAY AND BEST
LIFT WELL SOUTH AND EAST OF THE FORECAST AREA. DRIER AIR TO WORK INTO
THE PANHANDLES BY MONDAY NIGHT ALLOWING FOR CLEARING SKIES BY 12Z
TUESDAY. SLOWLY MODERATING TEMPS AND DRY TUESDAY THROUGH THE END OF
NEXT WEEK AS LEE SURFACE TROUGH DEVELOPS BY THE MIDDLE OF NEXT WEEK
AND WARMER SOUTHERLY FLOW PREVAILS. ANOTHER COLD FRONT MAY PUSH
THROUGH THE PANHANDLES BY NEXT SATURDAY.
SCHNEIDER
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY
THROUGH LATE NEXT WEEK.
SCHNEIDER
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
09/08