Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/27/15
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1103 AM CST WED NOV 25 2015
.UPDATE...
ISSUED AT 1058 AM CST WED NOV 25 2015
High pressure sliding off to the east while the next storm system
spins up over the southern Plains. A quick wave moving up through
the Upper Midwest bringing some light sprinkles with some of the
clouds this morning. Not measurable, but possibly enough to wet
pavement. Cloud bases relatively high this morning, but steadily
moving into the area. Not a lot of changes for the forecast
overall, but a mention of sprinkles moving up the I-55 corridor
for the rest of today ahead of the approaching showers later
tonight.
&&
.SHORT TERM...(Today)
ISSUED AT 330 AM CST WED NOV 25 2015
The CWA is in between the high pressure to the east and the
developing weather system in the plains. In this position, breezy
southerly winds and warmer temperatures are to be expected today.
With the increasing waa ahead of the developing system, an increase
in low level moisture is occurring, which is will bring an increase
in cloud cover to the area. The increasing clouds could retard the
warming trend this afternoon, but believe the strong waa should be
able to compensate. So, am expecting skies to become mostly cloudy
today with highs in the 50s and southerly winds of 15 to 25 mph.
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 330 AM CST WED NOV 25 2015
00Z models are similar with cold front moving east into the IL river
valley Thu night and across eastern IL Friday afternoon. Aloft,
strong 538 dm 500 mb low over northern CA into nw NV will move
across the central Rockies on Thu and remain near the Rockies this
weekend and eject ne into the Midwest and Great Lakes on Monday
night and Tue. This will likely bring an extended unsettled weather
pattern to IL with daily rain chances through early next week.
Chances of light rain showers moves into the IL river valley this
evening and deeper into central IL overnight while southeast IL
remains dry. Milder lows tonight in the upper 40s to around 50F with
clouds and breezy south winds. Clouds and breezy south winds
continue Thu with highs in the upper 50s and lower 60s. Rain chances
also increase to 60-80% nw of the IL river by Thu afternoon and 40-
50% over heart of central IL while only 20-30% in southeast IL and
near the IN border. Rainfall amounts even nw of the IL river appear
fairly light on Thu with highest amounts near a quarter inch by
Galesburg.
Increased lift with approaching cold front and deeper moisture to
bring highest rain chances Thu night into Friday along with heaviest
rainfall ranging from 1-1.5 inches with rain chances likely
lingering over southeast IL Friday night where storm total rainfall
of 1.50-1.75 inches. This may cause some rivers and streams to go
back to near flood especially at Clay City on the Little Wabash
river. Flash flood guidance is 1.5-2 inches per hour and 2-3 inches
in 6 hours so these rainfall amounts are still less than that and
will hold off on a flood watch.
Surface low pressure to lift ne along frontal boundary just
southeast of the Ohio river into nw KY by Sunday morning. This will
likely lift showers back ne into central IL during this weekend
especially Sat night into Sunday morning. Highest rain chances will
be over southeast IL along with heaviest rainfall amounts. Even
though temps cool by this weekend, they still appear warm enough to
support rain over our area. Lingered 20-30% chances of light rain
showers early next work week as upper level low moves into the area
and keeps it cloudier and cooler.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 524 AM CST WED NOV 25 2015
Clear skies will give way to clouds around 5kft moving into the
area this morning. The clouds will begin in the west at SPI and
PIA, then spread east and reach CMI last. Based on satellite
trends and upstream observations, looks like heights will remain
VFR levels, around 3.5kft. The clouds will continue through the
day and into the night ahead of the next weather system. HRRR and
NAM12 bring some light/scattered pcpn into the area beginning
late this afternoon and into tonight. Given the waa and all the
clouds, though not that low, will go with VCSH at all TAF sites in
the new forecast for late this afternoon and into this evening.
Winds will be southerly through the period with daytime gusts to
around 25kts. Winds will decrease some during the evening, but
expecting gusts to continue.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...Auten
LONG TERM...07
AVIATION...Auten
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
524 AM CST WED NOV 25 2015
.SHORT TERM...(Today)
ISSUED AT 330 AM CST WED NOV 25 2015
The CWA is in between the high pressure to the east and the
developing weather system in the plains. In this position, breezy
southerly winds and warmer temperatures are to be expected today.
With the increasing waa ahead of the developing system, an increase
in low level moisture is occurring, which is will bring an increase
in cloud cover to the area. The increasing clouds could retard the
warming trend this afternoon, but believe the strong waa should be
able to compensate. So, am expecting skies to become mostly cloudy
today with highs in the 50s and southerly winds of 15 to 25 mph.
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 330 AM CST WED NOV 25 2015
00Z models are similar with cold front moving east into the IL river
valley Thu night and across eastern IL Friday afternoon. Aloft,
strong 538 dm 500 mb low over northern CA into nw NV will move
across the central Rockies on Thu and remain near the Rockies this
weekend and eject ne into the Midwest and Great Lakes on Monday
night and Tue. This will likely bring an extended unsettled weather
pattern to IL with daily rain chances through early next week.
Chances of light rain showers moves into the IL river valley this
evening and deeper into central IL overnight while southeast IL
remains dry. Milder lows tonight in the upper 40s to around 50F with
clouds and breezy south winds. Clouds and breezy south winds
continue Thu with highs in the upper 50s and lower 60s. Rain chances
also increase to 60-80% nw of the IL river by Thu afternoon and 40-
50% over heart of central IL while only 20-30% in southeast IL and
near the IN border. Rainfall amounts even nw of the IL river appear
fairly light on Thu with highest amounts near a quarter inch by
Galesburg.
Increased lift with approaching cold front and deeper moisture to
bring highest rain chances Thu night into Friday along with heaviest
rainfall ranging from 1-1.5 inches with rain chances likely
lingering over southeast IL Friday night where storm total rainfall
of 1.50-1.75 inches. This may cause some rivers and streams to go
back to near flood especially at Clay City on the Little Wabash
river. Flash flood guidance is 1.5-2 inches per hour and 2-3 inches
in 6 hours so these rainfall amounts are still less than that and
will hold off on a flood watch.
Surface low pressure to lift ne along frontal boundary just
southeast of the Ohio river into nw KY by Sunday morning. This will
likely lift showers back ne into central IL during this weekend
especially Sat night into Sunday morning. Highest rain chances will
be over southeast IL along with heaviest rainfall amounts. Even
though temps cool by this weekend, they still appear warm enough to
support rain over our area. Lingered 20-30% chances of light rain
showers early next work week as upper level low moves into the area
and keeps it cloudier and cooler.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 524 AM CST WED NOV 25 2015
Clear skies will give way to clouds around 5kft moving into the
area this morning. The clouds will begin in the west at SPI and
PIA, then spread east and reach CMI last. Based on satellite
trends and upstream observations, looks like heights will remain
VFR levels, around 3.5kft. The clouds will continue through the
day and into the night ahead of the next weather system. HRRR and
NAM12 bring some light/scattered pcpn into the area beginning
late this afternoon and into tonight. Given the waa and all the
clouds, though not that low, will go with VCSH at all TAF sites in
the new forecast for late this afternoon and into this evening.
Winds will be southerly through the period with daytime gusts to
around 25kts. Winds will decrease some during the evening, but
expecting gusts to continue.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Auten
LONG TERM...07
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
619 PM EST THU NOV 26 2015
.SYNOPSIS...
ISSUED AT 345 PM EST THU NOV 26 2015
RAIN SHOWERS WILL MOVE INTO THE AREA OVERNIGHT...GRADUALLY SPREADING
SOUTHEASTWARD INTO FRIDAY. LOWS WILL RANGE FROM 46 TO 53. HIGHS
FRIDAY WILL RANGE FROM THE UPPER 40S TO THE UPPER 50S...WARMEST
SOUTHEAST OF US 24. OTHERWISE...A MILD AND QUIET WEEKEND IS IN STORE
WITH HIGHS IN THE 40S AND LOWS IN THE UPPER 20S AND 30S.
&&
.UPDATE...
ISSUED AT 553 PM EST THU NOV 26 2015
GRID/ZONE UPDATE OUT TO SLOW DOWN ARRIVAL OF LARGE BAND OF RAIN
INTO THE FORECAST AREA PRIOR TO 6Z. UPSTREAM TRENDS GIVE LITTLE
HOPE OF ANYTHING MEASURABLE MAKING IT INTO FAR NW AREAS UNTIL
AFTER 4Z AT THE EARLIEST WITH RAP SHOWING EVEN LATER (6 TO 8Z).
WILL TAKE A LOOK AT 00Z SOUNDING DATA ONCE IT COMES IN AS WELL AS
RADAR TRENDS AND SEE IF ADDITIONAL UPDATE IS NEEDED.
OTHERWISE A VERY BALMY, BUT BREEZY THANKSGIVING EVENING WILL BE IN
STORE FOR THE REGION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 347 PM EST THU NOV 26 2015
A COLD FRONT WILL MOVE SOUTHEAST TONIGHT ACROSS THE FORECAST AREA.
LARGE SCALE LIFT WAS WELL AHEAD OF THE FRONT EXTENDING FROM
NORTHEAST ILLINOIS INTO SOUTHERN WISCONSIN AND SOUTHEAST LOWER
MICHIGAN. NUMEROUS SHOWERS WERE OVER THIS AREA. PRECIPITABLE WATER
VALUES WERE SEASONALLY HIGH...HOWEVER... MOST UNSTABLE CAPE VALUES
WERE LESS THAN 100 J/KG THIS AFTERNOON. KEPT THUNDER OUT FOR NOW.
EXPECT RAIN TO DEVELOP TONIGHT AND CONTINUE INTO FRIDAY ON EITHER
SIDE OF THE FRONT. CONCERN FOR HYDRO/FLOOD ISSUES AS ALTHOUGH ALL
THE SNOW HAS MELTED...RAINFALL AMOUNTS TONIGHT INTO FRIDAY MAY BE
ENOUGH TO CAUSE RISES ON RIVERS AND MAY CAUSE PONDING OF WATER
AND POSSIBLY SOME ROAD FLOODING WHERE STORM DRAINS MAY BE
PARTIALLY OR FULLY OBSTRUCTED FROM LEAVES OR GRASS. PLAN TO
MENTION THESE CONCERNS IN AN UPDATED HAZARDOUS WEATHER OUTLOOK.
CLEARING HAD ALLOWED TEMPERATURES TO RISE INTO THE 60S THIS
AFTERNOON...ALTHOUGH CLOUDS SHOULD FILL BACK IN ACROSS THE AREA AS
THE FRONT APPROACHES.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 347 PM EST THU NOV 26 2015
SPLIT CONUS FLW TO START WILL GIVE WAY TO ZONAL FLW LT PD. LEAD NRN
STREAM SPLIT SW TROUGH WILL CONT EWD THROUGH SE CANADA SHRT TERM
ALLOWING SFC FNTL BNDRY TO CONT SLOWLY PUSHING OFF TO THE S/SE
W/RAIN LINGERING FRI NIGHT. SFC RIDGE WILL BLD EWD THROUGH THE SRN
LAKES THEREAFTER AS FNTL BNDRY STALLS ACRS THE TN VALLEY ON SUN.
UPSTREAM DEEP CLOSED LOW OVR THE ROCKIES THEN EJECTS OUT INTO THE
CNTRL PLAINS ON MON AS SFC FNT LIFT BACK NORTH INTO THE OH VALLEY
W/RAIN RTNG PRIMARILY LT MON THOUGH EARLY TUE. VIGOROUS/DEEP
CYCLONIC FLW ACRS THE LAKES TUE NIGHT/WED MAY BRING A FEW SPITS OF
RAIN OR SNOW WITHIN LL CAA WING W/DRY AND SEASONABLY COOL WX XPCD IN
WAKE OF THIS SYS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 553 PM EST THU NOV 26 2015
(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 117 PM EST THU NOV 26 2015
WILL BE SLOWING DOWN ARRIVAL OF ANY RAINFALL AS WELL AS LOWER
FLIGHT CONDITIONS TILL CLOSER TO 6Z AND MAYBE LATER AT KSBN AS
UPSTREAM TRENDS AND HI RES GUIDANCE SUGGEST IT WILL TAKE A WHILE
FOR THE LARGE BAND OF RAIN AND ASSOCIATED FRONT TO WORK EAST AND
SOUTH. AHEAD OF IT STRONG LOW LEVEL FLOW WILL CONTINUE TO POSE A
LOW LEVEL WIND SHEAR THREAT THROUGH THE EVENING...SUBSIDING
SLIGHTLY OVERNIGHT. AS FOR KFWA...WILL PUSH BACK TIMING OF PRECIP
HERE AS WELL. GUSTY WINDS WILL PERSIST THROUGH THE NIGHT AT BOTH
SITES.
RAIN AND STRATUS MAY LINGER WELL THROUGH THE TAF PERIOD ONCE IT
ARRIVES BUT WILL REMAIN SOMEWHAT OPTIMISTIC AND TRY TO TIME THINGS
OUT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
UPDATE...FISHER
SYNOPSIS...MDODSON
SHORT TERM...SKIPPER
LONG TERM...T
AVIATION...FISHER
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
556 AM CST WED NOV 25 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
ISSUED AT 332 AM CST WED NOV 25 2015
DRIZZLE/RAIN/FOG POTENTIAL WERE THE MAIN CONCERNS FOR TODAY`S
FORECAST. A COUPLE SIGNIFICANT CHANGES...DELAYED THE ONSET OF
DRIZZLE UNTIL LATE MORNING/EARLY AFTERNOON AND THEN INCREASED POPS
LATE THIS AFTERNOON. LEANED TOWARD A RUC13/HRRR/SREF FOR TIMING OF
POPS TODAY.
THE STRATUS SHIELD CONTINUES TO ADVECT NORTHWARD AND WILL BLANKET
THE FORECAST AREA THROUGHOUT THE DAY TODAY. COLD FRONT LOOKS TO
CREEP INTO THE FAR NORTHWEST CORNER OF THE STATE LATER THIS AFTER
AFTERNOON AND THE LOW-LEVEL MOISTURE (BELOW 750MB) GRADUALLY
INCREASES DURING THE MORNING HOURS AND POOLS AHEAD OF THE FRONT OVER
CENTRAL IOWA BY THE AFTERNOON. THE MOISTURE ADVECTION IS SHOWN WELL
ON THE ISENTROPIC SURFACES FROM 290-300K. THE DRIZZLE REALLY
BLOSSOMS OVER CENTRAL IOWA BY AROUND 21Z AND THE LATEST HRRR
(25.05Z) HAS A GREAT HANDLE ON THIS TREND. DELAYED THE POPS OVER
MUCH OF THE FORECAST AREA UNTIL 17Z WITH A SLIGHT CHANCE ACROSS THE
SOUTHWEST B/T 15-17Z TODAY. THIS IS A PRIME EXAMPLE OF A HIGH
POPS/LOW QPF SCENARIO WHERE HIGH CONFIDENCE IN PRECIPITATION OVER
MUCH OF THE FORECAST AREA BUT LITTLE TO NO MEASURABLE PRECIPITATION
EXPECTED. HAVE MENTION OF AREAS OF DRIZZLE THROUGH THE AFTERNOON AND
THEN PATCHY FOG PAST 21Z. CHANCE OF RAIN SEEMS REASONABLE GIVEN THE
DEPTH OF THE MOISTURE GRADUALLY INCREASING THIS AFTERNOON BUT
BELIEVE THE PREDOMINANT WEATHER WILL BE DRIZZLE THROUGH 00Z
THURSDAY. NO SIGNIFICANT CHANGES TO ONGOING MAX TEMPS TODAY WITH A
MINOR INCREASE OVER THE SOUTH PER DECENT WAA AND INCREASED MOISTURE.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 332 AM CST WED NOV 25 2015
CONCERNS BECOMING MORE APPARENT FOR ACCUMULATING ICE OVER THE WEST
AND SOUTHWEST BY THURSDAY AFTERNOON AND THEN CONTINUING INTO THE
NIGHTTIME HOURS SOUTHEAST. MODELS CONTINUE IN GENERAL AGREEMENT
WITH COLD AIR SLIDER BENEATH THE TROUGH OVER THE WEST AND
NORTHWEST BY 36 HOURS. PRIOR TO THAT SIGNIFICANT UPGLIDE ACROSS
THE SFC BOUNDARY WITH STRONG MOISTURE TRANSPORT WILL RESULT IN
RATHER ROBUST RAINFALL AMOUNTS FOR LATE NOVEMBER ACROSS THE
CENTRAL AND SOUTHEAST WHERE UPWARDS OF 1.75 TO NEARLY 2 INCHES OF
RAINFALL IS EXPECTED. THE GFS EVEN BRINGS DIMINISHING ELEVATED
CAPE TO THE BORDER AND OVER SOUTHERN IOWA ON THURSDAY...BUT FOR
NOW WILL LEAVE OUT OF GRIDS. TONIGHT WILL FEATURE MOISTURE
TRANSPORT INCREASING ALONG THE BOUNDARY WITH SOUNDINGS CONTINUING
TO SATURATE ALONG WITH TEMPERATURES REMAINING NEARLY STEADY IN THE
LOWER 30S NORTHWEST TO THE UPPER 40S IN THE SOUTHEAST FROM
MIDNIGHT THROUGH TOMORROW MORNING. AS RAINFALL INCREASES NORTHWEST
AND THE BOUNDARY BEGINS TO DRIFT SOUTHEAST AS THE WAVE
APPROACHES...BUFR SOUNDINGS OVER THE WEST SHOW THAT THE COLD AIR
NEAR THE SFC WILL BEGIN TO UNDERCUT THE WARMER AIR ALOFT CREATING
A PERIOD OF 2 TO 3 HOURS OF FREEZING RAIN BEGINNING OVER THE
NORTHWEST AROUND 12Z THEN PROGRESSING SOUTH SOUTHEAST DURING THE
DAY AND AFTERNOON HOURS AS THE COLDER AIRMASS CONTINUES TO
UNDERCUT THE BOUNDARY THROUGH THE AFTERNOON HOURS.
THERE ARE SEVERAL UNCERTAINTIES IN THE FORECAST FOR ICE
ACCUMULATION THAT NEED TO BE ADDRESSED/CONSIDERED. FIRST WE WILL
BE MILD OVER MUCH OF THE AREA TODAY AND A PORTION OF TONIGHT PRIOR
THE CHANGEOVER BEGINNING TOMORROW MORNING. SECOND...THE SATURATED
GROUND MAY RETAIN MORE HEAT AND COOL LESS QUICKLY ONCE THE COLDER
AIR ADVANCES ACROSS THE AREA. THESE TWO FACTORS MAY REDUCE THE
TOTAL ICE ACCUMULATION ON GROUND SURFACES...BUT OBJECTS THAT COOL
QUICKLY WITH AIR TEMPERATURE CHANGES WILL MORE LIKELY ACCUMULATE
ICE AT A MORE NORMAL RATE. THUS...THE IMPACTS MAY BE MORE RELATED
TO ICE ACCUMULATION ON METAL OBJECTS...COLDER SURFACES AND
EVENTUALLY ROADS AS TEMPERATURES CONTINUE TO COOL THROUGH THE
EVENING HOURS. GIVEN THE TIMING OF THE CHANGEOVER...THE
NORTHWEST/WEST AREAS LOOK TO IN LINE TO RECEIVE MORE FREEZING RAIN
THEN AREAS IN THE CENTRAL AND SOUTHEAST. HOWEVER THAT BEING
SAID...THE CHANGEOVER WILL AFFECT MOST OF THE FORECAST AREA WITH
SOME FREEZING RAIN. CURRENTLY HAVE OUTLINED THE AREAS THAT HAVE
THE POTENTIAL TO REACH NEAR .20 ICE ACCUMULATIONS OR SLIGHTLY
HIGHER WITH A WATCH. ELSEWHERE THERE WILL STILL BE A DECENT CHANCE
AT SOME FREEZING RAIN POTENTIAL ACROSS NORTH CENTRAL THROUGH WEST
CENTRAL AREAS UP THROUGH 00Z AND THEN ACROSS THE SOUTHWEST THROUGH
NORTHEAST FROM 00 THROUGH 06Z FROM NEAR CRESTON NORTHEAST TO ABOUT
DES MOINES/AMES TO NEAR WATERLOO. THESE AREAS MAY RECEIVE UP TO A
TENTH OF AN INCH OF ICE ACCUMULATION. WILL LET THE DAY SHIFT
EVALUATE BUT LIKELY OTHER AREAS WILL NEED AN ADVISORY. AFTER 06Z
THE MOISTURE TRANSPORT BEGINS TO WEAKEN WITH ICE INTRODUCTION
ALOFT BECOMING LESS PREVALENT. THIS WILL RESULT IN LESSER ICE
ACCUMULATION...IF ANY IN THE SOUTHEAST. SNOWFALL AMOUNTS HAVE BEEN
CUT BACK WITH UP TO AN INCH IN THE NORTHWEST TO ABOUT A HALF INCH
THROUGH CENTRAL AREAS.
HIGHS THURSDAY WILL BE REACHED EARLY IN THE DAY WITH FALLING
TEMPERATURES FOR THE AFTERNOON AND EVENING HOURS. HIGH
TEMPERATURES FOLLOWING THE STORM WILL SETTLE INTO THE 30S FOR
FRIDAY AND SATURDAY. THE MODELS ARE ALREADY ADVERTISING THE CLOSED
LOW OVER THE WEST TO OPEN UP AND TRACK ACROSS THE CENTRAL
PLAINS/GREAT LAKES BY LATER ON SUNDAY INTO MONDAY. THE EURO IS A
BIT SLOWER BUT OVERALL THERE SHOULD BE A MIX OF RASN WITH THIS
EVENT. STILL A FAIR AMOUNT OF UNCERTAINTY WITH THE STORM AS IT
TRACKS EAST/NORTHEAST ACROSS THE REGION. BEYOND TUESDAY THE
PATTERN IS FORECAST TO RELAX AS A RIDGE BEGINS TO BUILD ACROSS THE
WEST.
&&
.AVIATION...25/12Z
ISSUED AT 540 AM CST WED NOV 25 2015
EXPECTING MVFR CIGS MOVE INTO THE TAF AREA LATE THIS MORNING AND
IFR/LIFR VIS/CIGS LATER THIS AFTERNOON INTO EARLY EVENING WITH
DRIZZLE DEVELOPING OVER MUCH OF CENTRAL IOWA. LOW CIGS CONTINUE
INTO THURSDAY MORNING WITH SOME IMPROVEMENT IN VIS AS PRECIP
CHANGES OVER TO MORE RAIN THAN DRIZZLE THIS EVENING. HRRR KEEPS
LIFR/IFR CIGS AT DSM/OTM/ALO THROUGH AT LEAST 08Z THURSDAY AND
HENCE HIGH CONFIDENCE WITH LOWER CIGS PERSISTING LATE IN THE
PERIOD.
&&
.HYDROLOGY...
ISSUED AT 326 AM CST WED NOV 25 2015
STILL SOME POTENTIAL FOR MINOR RIVER FLOODING SOUTHEAST A FEW DAYS
FOLLOWING THE RAINFALL...GIVEN THE PREVIOUS SNOWMELT NORTH AND THE
COMBINATION OF ADDITIONAL RAINFALL TONIGHT/THURSDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR ADAIR-ADAMS-AUDUBON-CALHOUN-CARROLL-CASS-CRAWFORD-
GREENE-GUTHRIE-POCAHONTAS-SAC-UNION.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...REV
AVIATION...PODRAZIK
HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
329 AM CST WED NOV 25 2015
.SYNOPSIS...
ISSUED AT 329 AM CST WED NOV 25 2015
SATELLITE FOG CHANNEL IMAGERY EARLY THIS MORNING SHOWED A LARGE
TONGUE OF STRATUS ASSOCIATED WITH MOISTURE ADVECTION LOCATED
FROM THE WESTERN GULF NORTHWARD THROUGH OK...KS AND MO INTO
IA...REACHING INTO THE WESTERN HALF OF THE FORECAST AREA. THIS
WAS IN RESPONSE TO THE INCREASING SOUTHERLY FLOW BETWEEN HIGH
PRESSURE OVER THE MID ATLANTIC REGION AND DEVELOPING LOW PRESSURE
LEE OF THE ROCKIES. SOUTH TO SOUTHEAST WINDS HOLDING AROUND 10 TO
15 MPH ACROSS THE LOCATE AREA AT THE SURFACE WERE PROVIDING
ENOUGH LOW LEVEL MIXING TO NEGATE ANY THREAT OF FOG THIS
MORNING...AND ALSO HOLDING TEMPERATURES IN A RELATIVELY MILD RANGE
FROM THE MID 30S TO MID 40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CST WED NOV 25 2015
INCREASING MOISTURE AND EVENTUAL MID LEVEL LIFT AS THE DEVELOPING
PLAINS FRONTAL SYSTEM APPROACHES WILL RESULT IN INCREASING
CLOUDS...AND EVENTUALLY LIGHT RAIN OR DRIZZLE OVER MUCH OF THE AREA
BY TONIGHT. THE BEST POTENTIAL FOR FOG NOW LOOKS TO BE LATER TONIGHT
AND TONIGHT...MAINLY OVER THE DEEPEST SNOWFIELDS AND WHERE LOW LEVEL
MOISTURE BEGINS TO CONVERGE AHEAD OF THE APPROACHING FRONT.
TODAY...BASED ON THE RATE OF MOISTURE RETURN...WITH SURFACE
DEWPOINTS IN THE 40S AND 50S STILL WELL TO THE SOUTH...THE DELAY IN
THE ONSET OF RAIN CHANCES TO MAINLY AFTERNOON INTO EVENING SHOWN BY
THE 06Z NAM LOOKS REASONABLE. THUS HAVE SLIGHT CHANCE POPS FOR LIGHT
RAIN DEVELOPING IN THE FAR NW THIS MORNING...THEN INCREASING POPS
FOR LIGHT RAIN OR DRIZZLE FROM NW TO SE DURING THE AFTERNOON AS
DEEPER SATURATION OCCURS ALONG WITH INCREASING MID LEVEL LIFT AHEAD
OF A WEAK SHORTWAVE IN THE SW FLOW ALOFT. THE POTENTIAL FOR FOG
DURING THE DAY LOOKS LIMITED TO THE FAR NORTH AND NW OVER THE DEEPER
REMAINING SNOW AND WHERE ANY WEAK LOW LEVEL MOISTURE CONVERGENCE
IS MAXIMIZED. QPF AMOUNTS WILL BE LESS THAN A TENTH OF AN INCH.
TEMPERATURES WILL CONTINUE TO GRADUALLY RISE...DESPITE MOST SITES
BECOMING OVERCAST BY MID MORNING. HIGHS BY LATE AFTERNOON WERE
KEPT IN A RANGE FROM THE LOWER 40S NORTH TO THE MID 50S IN THE FAR
SOUTH.
TONIGHT...MODEL CONSENSUS HAS THE DEVELOPING PLAINS COLD FRONT
APPROACHING FROM THE WEST...IN A SW TO NE ORIENTATION...APPROACHING
INDEPENDENCE AFTER 12Z. AN INCREASING MOISTURE FEED AHEAD OF THIS
BOUNDARY...LOW LEVEL CONVERGENCE...AND LIFT FROM MID LEVEL WAVES IN
THE SW FLOW WILL LEAD TO WIDESPREAD RAIN OVER THE AREA. ANY FOG WILL
AGAIN BE MOST LIKELY HELD TO THE NORTH AND NW THE FORECAST
AREA...BUT THIS IS NOT LIKELY TO BE DENSE DURING THIS PERIOD. QPF
AMOUNTS WILL STILL BE RATHER LIGHT...WITH UP TO A QUARTER INCH IN
THE FAR NW...IN THE STRONGEST FORCING AND CONVERGENCE...TO A FEW
HUNDREDTHS OF AN INCH IN THE EAST AND SE. THE MOIST AIRMASS AND
BRISK SOUTHERLY LOW LEVEL FLOW WILL KEEP TEMPERATURES NEARLY
STEADY THROUGH THE NIGHT IN THE 40S AND 50S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 329 AM CST WED NOV 25 2015
MAIN FORECAST CONCERN IN THE LONG TERM ARE NUMEROUS CHANCES FOR
PRECIPITATION...IN THE FROZEN AND LIQUID FORM...DURING THIS BUSY
HOLIDAY WEEKEND. AT THIS TIME IT APPEARS THAT DURING THANKSGIVING
AND INTO FRIDAY ALL PRECIP WILL BE LIQUID...AFTER THIS...FOR THE
WEEKEND IT BECOMES MORE TRICKY. FROZEN PRECIP COULD BE POSSIBLE AT
NIGHT WITH LIQUID DURING THE DAY AS MODELS AGAIN ARE STRUGGLING WITH
THE CLOSED LOW/BLOCKING PATTERN OVER THE ROCKIES.
THANKSGIVING THROUGH FRIDAY AFTERNOON...
RAIN SHOULD BE ONGOING AT THE BEGINNING OF THE PERIOD. LOW LEVEL
OMEGA AND ISENTROPIC ASCENT SUGGESTS THAT MOST OF THE HEAVIEST
PRECIP WILL BE WEST OF THE RIVER AT 12Z. LIGHT RAIN COULD BE ONGOING
ACROSS THE AREA...HOWEVER THE STRONGEST RAIN WILL BE LOCATED WITH
THE RISING MOTION ASSOCIATED WITH THE FRONT AS LARGE SCALE VORTICITY
ADVECTION IS WEAK. THE 00Z NAM 4KM SHOWS A LINE OF MODERATE
RAINSHOWERS... VIRTUALLY COLLOCATED WITH THE FRONT. THIS MODEL
DEPICTS THE BAND OF RAIN ENTERING OUR CWA AROUND 18Z AND MARCHING
THROUGH THE AREA AND EXITING BY 09Z FRIDAY. RAINFALL TOTALS OF 1 TO
2 INCHES ARE POSSIBLE WITH THE HIGHEST AMOUNTS LOCATED ALONG A LINE
FROM DBQ TO CID TO MARENGO. IT IS SAFE TO SAY THAT THANKSGIVING WILL
BE WET ACROSS OUR AREA. AS THE FRONT MOVES THROUGH THE
AREA....LINGERING PRECIP WILL ENCOUNTER COLD AIR AT THE LOW LEVELS.
WITH LARGE SCALE FLOW STILL OUT OF THE SW...A 1044 HPA HIGH TRIES TO
BUILD INTO THE AREA. IT WILL BE INTERESTING TO SEE HOW DEEP THE
COLD DOME IS AS MODELS SUGGEST A MODEST WARM NOSE ALOFT AS THE COLD
AIR MOVES INTO THE LOW LEVELS. IN THIS SITUATION...PRECIP ON THE
BACK END...ESPECIALLY NORTH OF A LINE FROM MARENGO TO DUBUQUE
COULD TRANSITION OVER TO FZRA AND THEN TO SLEET AND EVEN POSSIBLY
SN. MY CONFIDENCE IS LOW IN THIS OCCURRING...AS SUCH ADDED SCHC
FZRA AND PL ACROSS THIS AREA IN THE NORTHWEST. AT THIS TIME...DO
NOT EXPECT ANY ICE OR SN ACCUMULATIONS FRI AM. ANYTHING THAT DID
FALL WOULD MELT AS HIGHS ARE FORECAST TO BE ABOVE FREEZING FRIDAY
AFTERNOON.
FRIDAY EVENING THROUGH MONDAY MORNING...
A HIGH OVER LOW BLOCK ACROSS THE WESTERN UNITED STATES PROVIDES
MODELS WITH A TRICKY FORECAST FOR THE WEEKEND. AS THIS IS A BUSY
TRAVEL WEEKEND...THE MODEL DISCREPANCIES HAVE MY CONFIDENCE IN THE
FORECAST VERY LOW. THE GFS HAS A WAVE THAT PUSHES THE LOW TO EAST
FASTER THAN THE ECMWF. HOWEVER...THE ECMWF SLOWLY LUMBERS THE LOW
TOWARDS US AT THE SAME TIME. MODEL CONSENSUS FORECAST MOVES THE
1040+ HIGH THROUGH THE AREA QUICKLY THIS WEEKEND AS SW LOW LEVEL
FLOW ADVECTS MOISTURE BACK INTO THE AREA. THIS MEANS THAT THE
CHANCE FOR PRECIP RETURNS TO THE AREA SATURDAY THROUGH NEXT WEEK.
THIS WEEKEND IT LOOKS AS THOUGH SOME WINTRY MIX WILL FALL AT NIGHT
WITH RAIN DURING THE DAY. THIS WILL LEAD TO DIFFICULT FORECAST
ALONG WITH POSSIBLE TRAVEL ISSUES COME THIS WEEKEND ACROSS OUR AREA.
THOSE TRAVELING BACK OR THROUGH THE AREA THIS WEEKEND SHOULD PAY
ATTENTION TO FUTURE FORECASTS.
MONDAY ON...
MAJOR DIFFERENCES IN THE MODELS MAKE IT DIFFICULT TO HAVE ANY
CONFIDENCE IN THE FORECAST. WHAT ADDS TO THIS DIFFICULTY IS THE
PROXIMITY OF THE FREEZING LINE....THROUGH OUR CWA AT NIGHT AND JUST
NORTH DURING THE DAY. THERMAL PROFILES MAKE IT DIFFICULT TO DISCERN
WHAT TYPE OF FROZEN PRECIP IS EXPECTED. IF THE LOW STARTS TO MOVE
FROM THE BLOCKING PATTERN THEN INEVITABLY THIS FORECAST WILL BECOME
SLIGHTLY EASIER...UNTIL THEN OR THE MODELS AGREE ON A SOLUTION NO
CHANGES WILL BE MADE TO THE CURRENT BLENDED FORECAST. EXPECT
SPECIFICS TO CHANGE FOR THE SYSTEMS NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1131 PM CST TUE NOV 24 2015
MAIN ITEM OVERNIGHT AND THROUGH DAYBREAK IS LOW LEVEL WIND SHEAR.
KDVN VWP LAST 1-2 HRS HAS BEEN SHOWING 45 KTS AT 2KFT WHICH
VERIFIES RAP AND NAM SOUNDINGS... THUS CONTINUED MENTION OF
LLWS THROUGH ABOUT 14-15Z WEDNESDAY WITH SURFACE WINDS S/SE
AROUND 10-15 KTS. SOME PATCHY FOG IS STILL POSSIBLE TOWARD
DAYBREAK BUT CONFIDENCE DIMINISHING DUE TO WELL MIXED BOUNDARY
LAYER AND INCREASING CLOUDS. WILL SEE STRATUS OVERSPREAD THE
TERMINALS OVERNIGHT AND WEDNESDAY AM... WITH INITIALLY VFR CIGS
IN RANGE OF 3500-5000FT AGL. IN TIME WITH ARRIVAL OF BETTER LOW
LEVEL MOISTURE AND DEEPER SATURATION LATER IN THE DAY WEDNESDAY
AND WEDNESDAY NIGHT EXPECT TO SEE CIGS LOWER TO MVFR ESPECIALLY AT
KCID AND KDBQ WITH PATCHY DRIZZLE OR VERY LIGHT RAIN MAY OCCUR
WITHIN WHERE BEST MOISTURE TRANSPORT IS DEPICTED. THERE IS A
CHANCE OF SOME IFR CONDITIONS DEVELOPING AT KDBQ AND KCID LATE IN
THE TAF CYCLE...BUT CONFIDENCE TOO LOW FOR MENTION THIS FAR OUT.
HAVE ALSO MENTIONED MVFR CIGS AT KBRL AND KMLI BY WEDNESDAY
EVENING WITH LAMP AND GFS/NAM MOS GUIDANCE IN AGREEMENT...
HOWEVER SREF CIG HEIGHT PROBS VERIFYING PRETTY WELL LATE THIS
EVENING AND WOULD ACTUALLY SUPPORT BETTER POTENTIAL MAINLY TO
NORTH/WEST OF KBRL AND KMLI... WHICH IS SOMETHING TO MONITOR IN
LATER TAF ISSUANCES.
&&
.HYDROLOGY...
ISSUED AT 329 AM CST WED NOV 25 2015
LONG DURATION RAINFALL EVENT THROUGH THANKSGIVING AND INTO FRIDAY
MORNING COULD BRING RAINFALL AMOUNT FROM 1 TO 2 INCHES ACROSS THE
AREA. WITH SNOWPACK STILL ON THE GROUND...A LARGE PERCENTAGE OF
THIS STEADY RAIN COULD GO STRAIGHT TO RUNOFF. ENSEMBLE RIVER
FORECASTS SUGGEST RIVER FLOODING WHEN THE HIGHEST QPF IS USED. WHEN
USING QPF CLOSE TO WHAT IS FORECAST A FEW RIVERS GET TO ACTION
STAGE. CURRENT FORECASTS FOR KALONA AND MARENGO TAKE THESE SITES TO
FLOOD. AT THIS TIME...MY CONFIDENCE IN THIS OCCURRING AND THE
FORECAST QPF OCCURRING IS LOW. WE COULD GET ROBBED OF MOISTURE FROM
THE CONVECTION TO OUR SOUTH. WITH SUCH LOW CONFIDENCE IN THE QPF
FORECAST DECIDED TO HOLD OFF ON A FLOOD WATCH AND ISSUING FLOOD
WARNINGS FOR MARENGO AND KALONA.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...GIBBS
AVIATION...MCCLURE
HYDROLOGY...GIBBS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1145 PM CST TUE NOV 24 2015
.SYNOPSIS...
ISSUED AT 330 PM CST TUE NOV 24 2015
OTHER THAN PATCHY TO AREAS OF THIN CIRRUS...SKIES WERE SUNNY
ACROSS THE DVN CWA. MID AFTERNOON TEMPERATURES WERE IN THE MID TO
UPPER 30S ALONG HIGHWAY 20 WHERE THE DEEPEST SNOW COVER EXISTS...
TO THE LOWER 50S SOUTH OF HIGHWAY 34 WITH BARE GROUND.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM CST TUE NOV 24 2015
FORECAST FOCUS ON POTENTIAL FOR FOG AND CHANCE OF LIGHT RAIN ON
WEDNESDAY.
TONIGHT...A VEIL OF THICKENING CIRRUS WILL COVER THE CWA AS A
SHORT WAVE IN THE CENTRAL PLAINS MOVES ACROSS THE AREA IN THE
SOUTHWEST FLOW ALOFT. ALONG WITH SOUTHEAST TO SOUTH WINDS THIS
WILL MEAN TEMPERATURES WILL BE MUCH WARMER THAN THE PAST SEVERAL
NIGHTS. THE AIRMASS WILL STILL BE RATHER DRY SO BELIEVE FOG THAT
FORMS AFTER MIDNIGHT SHOULD REMAIN ON THE PATCHY SIDE. MINIMUM
TEMPERATURES WILL RANGE FROM THE LOWER 30S ALONG HIGHWAY 20 TO THE
UPPER 30S IN OUR FAR SOUTHERN CWA.
WEDNESDAY...SOUTHERLY WINDS WILL TRANSPORT INCREASING LOW LEVEL
MOISTURE FROM THE WESTERN GULF AS HIGH PRESSURE SITS OVER THE
SOUTHEAST UNITED STATES...AND A CLOSED LOW MOVES INTO NEVADA.
FORECAST SOUNDINGS INDICATE PWATS INCREASE TO 0.60 TO 0.80 INCHES
BY LATE AFTERNOON. WITH THE DETERMINISTIC MODELS SHOWING A 40 KNOT
LOW LEVEL JET FROM TX TO IA I DON`T SEE ANY REASON TO DISAGREE.
WITH THIS MOISTURE AND A COLD FRONT APPROACHING FROM THE WEST
THERE WILL BE A CHANCE OF SOME LIGHT RAIN OR DRIZZLE...MAINLY IN
THE AFTERNOON AND NEAR AND WEST OF THE MS RIVER. SKIES WILL ALSO
BECOME CLOUDY AS MODELS SPREAD/DEVELOP LOW STRATUS ACROSS THE CWA
DUE TO THE INCREASING LOW LEVEL MOISTURE...AND IT`S NOVEMBER.
MAXIMUM TEMPERATURES ARE EXPECTED TO RANGE FROM THE MID 40S ALONG
HIGHWAY 20 TO THE LOWER 50S IN OUR SOUTHERN CWA. HAASE
.LONG TERM...(WEDNESDAY NIGHT THROUGH NEXT TUESDAY)
ISSUED AT 330 PM CST TUE NOV 24 2015
WEDNESDAY NIGHT AND THURSDAY...STRENGTHENING AND DEEP
SOUTHWESTERLIES ON BACKSIDE OF LARGE ATLANTIC COAST RIDGE TO WARM-
MOIST ADVECT STRONGLY WED NIGHT...WITH PWAT/S PROJECTED TO SATURATE
TO 0.80 TO AROUND AND INCH BY DAYBREAK THU. MORE OF THE 12Z RUN
MODEL SOLUTIONS CONTINUE TO ADJUST WEST WITH MAIN NE-TO-SW ORIENTED
SFC FRONT ALIGNING UNDER THE FLOW...MAKING FOR MORE LLVL CONVERGENT
RAIN PRODUCTION/COVERAGE ACRS THE FAR NORTHWESTERN CWA LATE WED
NIGHT. THIS CONVERGENT AREA WHERE WINDS DROP OFF MAY BE WHERE THE
AREAS OF FOG FORM AFTER MIDNIGHT AS WELL. OTHERWISE THE REST OF THE
CWA JUST INCREASING PATCHY AREAS OF LIGHT RAIN OR DRIZZLE WITH A
SOUTH SFC BREEZE OF 10-15 MPH MAKING FOR STEADY TO SLOWLY RISING
TEMPS INTO THU MORNING. SEASONABLY STRONG WARM MOIST CONVEYOR IN
FULL SWING ON THU AND THU NIGHT EVENING...WITH THE MODELS HAVING
INCREASED PWATS TO VERY HIGH LEVELS FOR LATE NOVEMBER AND FROM
PREVIOUS RUNS...GENERALLY 1.1 TO 1.4 INCHES. THIS KIND OF SATURATION
COMBINED WITH DEEP VERTICAL LAYER POS OMEGAS EASILY SUPPORT A BAND
OF MODERATE RAINS RIDING UP ALONG THE FRONT AND POST-
FRONTALLY...SLOWLY PUSHING FROM WEST-TO-EAST THU INTO FRI MORNING
BEFORE CLEARING OFF TO THE EAST ACRS MOST OF THE AREA BY FRI
AFTERNOON. FURTHER WEST FRONTAL ADJUSTMENT SUPPORTS THE MOST
WIDESPREAD RAIN COVERAGE ALONG AND WEST OF THE MS RVR THROUGH 00Z
FRI...THEN PUSHING EAST THU NIGHT AND WILL BLANKET THE CWA WITH
HIGH/CATEGORICAL POPS ACCORDINGLY.
AGAIN BACK TO THE UNSEASONABLE SATURATION COMBINED WITH DURATION OF
LIFT...STILL SEE THE CWA GETTING WIDESPREAD 1-2 INCHES BY FRI
MORNING WHEN IT TAPERS OFF. BUT WILL ADJUST THE HEAVY RAINFALL AXIS
FURTHER WEST WITH LATEST THINKING AND ADVERTISE 1.5 TO 1.8+ INCHES
WEST OF A LINE FROM FREEPORT IL...TO THE QUAD CITIES AND TO KEOKUK
IA ON SOUTH ALONG THE MS RVR. 12-18 HOURS FOR THIS RAIN TO FALL WILL
HELP...BUT WILL CONTINUE TO TOUCH UPON THE ALREADY SATURATED
SOILS/SNOW MELT MAKING FOR MORE RUN-OFF THAN WHAT OCCURRED FOR AN
EVEN STRONGER EVENT BACK A WEEK AGO ON NOV 17TH. THUS SOME RIVER
LEVELS COULD REALLY COME UP TO BANKFULL OR EVEN FLOOD STAGE THROUGH
THE WEEKEND. DESPITE THE CLOUDS/PRECIP/SATURATION...A MILD TURKEY
DAY AHEAD OF THE FRONT WITH HIGHS IN THE MID 50S TO AROUND 60 ACRS
THE SOUTHEAST HALF OF THE FCST AREA...40S TO LOW 50S TO THE WEST OF
THAT UNLESS THE FRONT SLOWS MORE.
THE 12Z RUNS SUGGEST MARGINAL IN-WRAPPING LLVL COLD CONVEYOR AND
EVENTUAL TOP-DOWN COOLING ABOVE THAT PROCESS FOR A PRECIP SWITCH TO
SLEET OR FREEZING RAIN BRIEFLY ACRS THE FAR NORTHWESTERN CWA LATE
THU NIGHT...THEN TO A RAIN-SNOW MIX INTO FRI MORNING. FOR NOW WILL
ADVERTISE LESS THAN AN INCH OF WET SNOW ACCUM BY FRI MORNING
WEST/NORTHWEST OF THE CEDAR RAPIDS AREA. THE LLVLS MAY STAY WARM
ENOUGH FOR ALL RAIN ARRIVAL AT THE SFC ACRS THE EASTERN THIRD OF THE
DVN CWA THU NIGHT INTO FRI AM.
FRIDAY THROUGH SUNDAY...LATEST SUITE OF MEDIUM RANGE MODELS IN MORE
DISAGREEMENT IN HANDLING A SOUTHERN STREAM SYSTEM EJECTING OF OF THE
SOUTHERN PLAINS AND UP TOWARD THE REGION...BATTLING WESTERN GRT LKS
RIDGING AS IT DOES. TAKING A GENERAL ENSEMBLE BLEND...IT SUGGESTS
THAT A PRECIP SHIELD OFF THIS POTENTIAL SYSTEM MAY SPREAD UP ACRS THE
SOUTHERN 2/3S OF THE CWA FROM LATE SAT AND INTO SUNDAY. THE 12Z GFS
IS MILDER WITH IT/S LOW TO MID LEVEL THERMAL PARAMETERS AND SUGGESTS
MAINLY A OVERRUNNING LIGHT TO MODERATE RAIN EVENT ALONG AND SOUTH OF
THE HWY 30 CORRIDOR WITH RAIN ENDING BY LATE SUNDAY MORNING. THE
12Z ECMWF SUGGESTS A WINTRY MIX OF SLEET/FREEZING RAIN...THEN A
SWITCH OVER TO WET SNOW UP ALONG AND NORTH OF THE I80 CORRIDOR SAT
NIGHT...LINGERING LONGER INTO SUNDAY BUT SWITCHING OVER TO MAINLY A
COLD RAIN WITH COLUMN MODERATION ALOFT. WILL GO WITH HIGHER POPS
SOUTH AND ADVERTISE A RAIN-SNOW MIX IN THE NORTH FOR NOW...FURTHER
DEFINING PRECIP TYPES OVER THE NEXT SEVERAL DAYS AS WE GET CLOSER TO
THE PRECIP EVENT. HIGHS IN THE UPPER 30S TO 40S SAT INTO SUNDAY...
WITH LOWS AT NIGHT IN THE 20S TO LOWER 30S POSSIBLY BEING TOO COLD.
EARLY NEXT WEEK...THE MEDIUM RANGE SOLUTIONS STILL SUGGEST A CLOSED
UPPER LOW WITH VARYING THERMAL PROFILES DEPENDING ON THE MODEL...
ROLLING SLOWLY ACRS THE MIDWEST FOR OCCASIONAL PRECIP CHANCES FROM
LATE MONDAY THROUGH AT LEAST TUE NIGHT. ..12..
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1131 PM CST TUE NOV 24 2015
MAIN ITEM OVERNIGHT AND THROUGH DAYBREAK IS LOW LEVEL WIND SHEAR.
KDVN VWP LAST 1-2 HRS HAS BEEN SHOWING 45 KTS AT 2KFT WHICH
VERIFIES RAP AND NAM SOUNDINGS... THUS CONTINUED MENTION OF
LLWS THROUGH ABOUT 14-15Z WEDNESDAY WITH SURFACE WINDS S/SE
AROUND 10-15 KTS. SOME PATCHY FOG IS STILL POSSIBLE TOWARD
DAYBREAK BUT CONFIDENCE DIMINISHING DUE TO WELL MIXED BOUNDARY
LAYER AND INCREASING CLOUDS. WILL SEE STRATUS OVERSPREAD THE
TERMINALS OVERNIGHT AND WEDNESDAY AM... WITH INITIALLY VFR CIGS
IN RANGE OF 3500-5000FT AGL. IN TIME WITH ARRIVAL OF BETTER LOW
LEVEL MOISTURE AND DEEPER SATURATION LATER IN THE DAY WEDNESDAY
AND WEDNESDAY NIGHT EXPECT TO SEE CIGS LOWER TO MVFR ESPECIALLY AT
KCID AND KDBQ WITH PATCHY DRIZZLE OR VERY LIGHT RAIN MAY OCCUR
WITHIN WHERE BEST MOISTURE TRANSPORT IS DEPICTED. THERE IS A
CHANCE OF SOME IFR CONDITIONS DEVELOPING AT KDBQ AND KCID LATE IN
THE TAF CYCLE...BUT CONFIDENCE TOO LOW FOR MENTION THIS FAR OUT.
HAVE ALSO MENTIONED MVFR CIGS AT KBRL AND KMLI BY WEDNESDAY
EVENING WITH LAMP AND GFS/NAM MOS GUIDANCE IN AGREEMENT...
HOWEVER SREF CIG HEIGHT PROBS VERIFYING PRETTY WELL LATE THIS
EVENING AND WOULD ACTUALLY SUPPORT BETTER POTENTIAL MAINLY TO
NORTH/WEST OF KBRL AND KMLI... WHICH IS SOMETHING TO MONITOR IN
LATER TAF ISSUANCES.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...12
AVIATION...MCCLURE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1002 PM EST THU NOV 26 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE INTO NORTHERN MAINE LATE FRIDAY AND CROSS
THE REGION FRIDAY NIGHT. HIGH PRESSURE WILL BUILD ACROSS THE
REGION THROUGH THE WEEKEND. A COLD FRONT WILL CROSS THE REGION
SUNDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
930 PM UPDATE: WE DID RAISE POPS FOR ISOLD TO SCT SHWRS ACROSS
THE NW THIRD...WHICH INCLUDES THE FAR NE WITH RADAR NOW SHOWING
MORE IN THE WAY OF DEFINITIVE SHWRS CROSSING FURTHER E INTO NRN
ME FROM QB PROV. LATEST HRRR MODEL SIM RADAR REF SHOWS THIS CURRENT
BATCH OF SHWRS LASTING 2 TO 3 HRS...FOLLOWED BY A BREAK...WITH
MORE SCT-BKN CVRG SHWRS MOVG BACK INTO THE NW FROM QB ARND
DAYBREAK. FCST QPF BETWEEN NOW AND 7 AM IS ON THE VERY LGT SIDE
WITH SHWRS NOT LASTING LONG OVR LCTNS RECEIVING THEM.
OTHERWISE...WE UPDATED FCST HRLY AND OVRNGT LOW TEMPS BASED ON
LATEST OBSVD TEMPS AT 9 PM...WHICH INTERESTINGLY...SHOWED TEMPS
FALLING SIG BLO THE PRIOR FCST FOR OVRNGT LOWS OVR WRN ME JUST
SW OF OUR FA WHERE SKIES HAVE CLEARED. GIVEN SOMEWHAT VARIABLE
AMOUNTS OF BOTH LOW AND MID/HI CLDNSS XPCTD OVRNGT OVR SRN PTNS OF
THE OUR FA...THERE IS LOW CONFIDENCE IN FCST OVRNGT LOWS FOR THIS
PTN OF THE REGION.
ORGNL DISC: HIGH PRESSURE CONTINUES TO DOMINATE UNTIL LATE FRIDAY
WITH CONTINUED WARM ADVECTION AHEAD OF THE COLD FRONT. A
COMBINATION OF HIGH CLOUDS AHEAD OF THE FRONT AND AND LOWER CLOUDS
TRAPPED UNDER A SUBSIDENCE INVERSION WILL MAINTAIN GENERALLY
CLOUDY SKIES THROUGH THE PERIOD. THE COMBINATION OF WINDS...WARM
ADVECTION AND THE CLOUDS MEAN THAT LOWS WILL ONLY BE NOMINALLY
BELOW THIS AFTERNOON`S READINGS. THIS WILL ALLOW PREFRONTAL
TEMPERATURES ON FRIDAY TO REACH THE UPPER 40S TO LOWER 50S. RAIN
WILL BREAK OUT IN THE CROWN OF MAINE TOWARDS MID AFTERNOON AND
SLOWLY SPREAD SOUTH INTO THE EVENING. MUCH OF THE PRECIP WILL BE
BEHIND THIS FRONT AS WARM AND MOIST AIR FROM THE SUBTROPICAL JET
STREAM ASCENDS NORTHEASTWARD BEHIND THE SURFACE FRONT...OR
ANAFRONT. COLDER AIR WILL ARRIVE IN THE SAINT JOHN VALLEY IN THE
EVENING WITH A CHANGEOVER TO SNOW EXPECTED. EXPECT UP TO A QUARTER
INCH OF RAIN IN NORTHERN AROOSTOOK COUNTY BY EARLY EVENING.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
A COLD FRONT WILL CROSS THE REGION FRIDAY NIGHT WITH AN AREA OF
RAIN IN ADVANCE OF THE FRONT. COLDER AIR IN THE WAKE OF THE FRONT
WILL ALLOW THE PRECIPITATION TO CHANGE TO SNOW BEFORE ENDING
ACROSS NORTHERN PORTIONS OF THE FORECAST AREA. ANY SNOW
ACCUMULATIONS ACROSS NORTHERN AREAS ARE GENERALLY EXPECTED TO BE
LESS THAN AN INCH. HIGH PRESSURE WILL BUILD ACROSS THE REGION
LATER FRIDAY NIGHT THROUGH SUNDAY. EXPECT DECREASING CLOUDS ACROSS
THE REGION SATURDAY MORNING...WITH MOSTLY SUNNY SKIES DURING THE
AFTERNOON. GENERALLY EXPECT MOSTLY CLEAR SKIES ACROSS THE REGION
SATURDAY NIGHT. HOWEVER...CLOUDS COULD BEGIN TO INCREASE ACROSS
NORTHERN AREAS LATE IN ADVANCE OF AN APPROACHING COLD FRONT AND
UPPER LEVEL DISTURBANCE. THE COLD FRONT WILL CROSS THE REGION
SUNDAY...WITH AN UPPER LEVEL DISTURBANCE CROSSING NORTHERN MAINE
DURING THE AFTERNOON. EXPECT PARTLY SUNNY/MOSTLY CLOUDY SKIES
ALONG WITH A SLIGHT CHANCE OF SNOW SHOWERS ACROSS NORTHERN AREAS
SUNDAY...WITH PARTLY/MOSTLY SUNNY SKIES ACROSS CENTRAL AND
DOWNEAST PORTIONS OF THE FORECAST AREA. TEMPERATURES WILL BE AT
NEAR NORMAL...TO SLIGHTLY BELOW NORMAL...LEVELS SATURDAY/SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE EXTENDED FORECAST PERIOD WILL START OUT DRY SUNDAY NIGHT
THROUGH MONDAY NIGHT WITH A LARGE HIGH PRESSURE OVER THE
NORTHEAST. THIS RIDGE WILL GIVE WAY TO A LARGE LOW PRESSURE SYSTEM
DEVELOPING OVER THE MIDWEST/GREAT LAKES WHICH WILL PROPAGATE EWRD
NEW YORK AND NEW ENGLAND DURING THE MIDDLE PART OF NEXT WEEK. THE
PRECIP ASSOCIATED WITH THIS DISTURBANCE WILL OVERSPREAD ALL OF OUR
CWA THURSDAY NIGHT...MAINLY IN THE FORM OF SNOW EXCEPT ACROSS FAR
DOWNEAST AREAS. HOWEVER STRONG SOUTHERLY FLOW WILL DRAW WARM AIR
NORTH AND MOST OF THE PRECIP WILL MIX WITH AND CHANGE OVER TO RAIN
BY WEDNESDAY AFTERNOON. THE LOW WILL THEN MOVE EAST OF OUR CWA
WEDNESDAY NIGHT AND THURSDAY...DRAGGING A STRONG COLD FRONT SEWRD
ACROSS THE CWA...CHANGING THE RAIN BACK TO A WINTRY MIX OR ALL
SNOW. THERE ARE SOME TIME DIFFERENCES BETWEEN THE GFS AND ECMWF
SOLUTIONS...BUT BOTH SHOW THIS SAME EVENT.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: CONDITIONS WILL VARY BETWEEN VFR AND MVFR CEILINGS.
NAM GUIDANCE LOOKS TOO MOIST WITH A RELATIVELY DRY SW FLOW AND NO
PRECIP UNTIL LATER FRIDAY. HOWEVER...THE STRONG SUBSIDENCE
INVERSION WILL TRAP MOISTURE AT MVFR CEILING HEIGHTS AT TIMES
THROUGH THE PERIOD.
IFR DUE TO RAIN AND CEILINGS WILL HIT FVE...CAR AND PQI LATE
FRIDAY AFTERNOON.
SHORT TERM: MVFR TO LIFR CONDITIONS ARE EXPECTED ACROSS THE REGION
EARLY FRIDAY NIGHT...WITH IMPROVING CONDITIONS LATE. GENERALLY
EXPECT VFR CONDITIONS ACROSS THE REGION SATURDAY THROUGH SATURDAY
NIGHT...THOUGH MVFR CEILINGS COULD LINGER DOWNEAST EARLY SATURDAY.
OCCASIONAL MVFR CONDITIONS ARE POSSIBLE ACROSS NORTHERN MAINE
SUNDAY. OTHERWISE...GENERALLY VFR CONDITIONS ARE EXPECTED ACROSS
THE REGION SUNDAY INTO TUESDAY. IFR/LIFR CONDITIONS COULD THEN
DEVELOP TUESDAY NIGHT.
&&
.MARINE...
NEAR TERM: THE SCA WILL CONTINUE INTO FRIDAY EVENING WITH 25 TO 30
KTS GUSTS AND SEAS REACHING UP TO 6 FT.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED FRIDAY
NIGHT THROUGH SATURDAY. CONDITIONS ARE THEN EXPECTED TO BE BELOW
SMALL CRAFT ADVISORY LEVELS SATURDAY NIGHT/SUNDAY. VISIBILITIES
WILL BE REDUCED IN RAIN FRIDAY NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORCROSS
LONG TERM...CB/BERDES
AVIATION...VJN/NORCROSS
MARINE...VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1236 AM EST WED NOV 25 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 332 PM EST TUE NOV 24 2015
12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW AN UPR RDG OVER
THE PLAINS EXPANDING INTO THE GREAT LKS. 00Z-12Z H5 HGT RISES OVER
MUCH OF THE W HALF OF THE GREAT LKS WERE AOA 100M AND AS MUCH AS
130M AT APX AND DTX. THE 12Z INL/GRB/APX RAOBS SHOW SHARP SUBSIDENCE
INVRN IN THE H8-85 LYR. DESPITE TEMPS AT THIS ELEVATED INVRN BASE AS
LO AS -10C...RATHER DRY NATURE OF THE SUB INVRN LYR AS DEPICTED ON
THE INL AND GRB RAOBS HAS GREATLY RESTRICTED LES EVEN OVER THE E...
WHERE THE LLVL NW FLOW WAS WEAKLY CYC THIS MRNG AHEAD OF A WEAK SFC
RDG AXIS OVER THE WRN CWA EXTENDING TO THE N OF STRONGER HI CENTER
IN THE TN RIVER VALLEY. THE LO CLDS HAVE BROKEN UP SOMEWHAT WITH THE
ARRIVAL OF THE SFC RDG OVER THE W AND SCENTRAL. EVEN WHERE THE LO
CLDS HAVE DSPTD...A GOOD AMOUNT OF MID/UPR LVL MSTR ASSOCIATED WITH
STRONGER WAA IN THE NRN PLAINS IS SUPPORTING AREA OF MID/HI CLDS
SPILLING OVER THE RDG INTO THE WRN LKS.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON THE IMPACT OF
STRENGTHENING SLY FLOW THAT IS FCST TO DEVELOP TNGT/WED BETWEEN SFC
HI PRES RDG FCST TO MOVE E/BUILD UNDER THE EXPANDING UPR RDG AND
FALLING MSLP IN THE PLAINS TO THE E OF A DEEPENING TROF OVER THE W.
TNGT...SFC HI PRES SHIFTING E INTO NEW ENGLAND/MID ATLANTIC STATES
IS FCST TO BUILD TO ABOUT 1040MB BY 12Z WED. IN CONCERT WITH DVLPG
LO PRES TROF ALONG THE BORDER BTWN MN AND THE DAKOTAS...THE PRES
GRADIENT OVER THE WRN GREAT LKS IS FCST TO TIGHTEN CONSIDERABLY...
WITH S H925 WINDS INCRSG UP TO 35-40KTS ACCENTUATED BY DVLPG PRES
FALL CENTER OVER NW ONTARIO. MODELS SHOW AN AXIS OF HIER RH IN THE
SFC-H9 LYR RETURNING INTO THE CENTRAL CWA OVERNGT WITHIN THIS
STRENGTHENING SLY FLOW AND UNDER LINGERING LARGER SCALE SUBSIDENCE
INVRN. WITH AN UPSOPE LLVL SSE FLOW... MAINTAINED SOME FCST -DZ/
-FZDZ IN THIS AREA. LIMITED DEPTH OF RETURNING MOIST LYR AND/OR
DOWNSLOPE FLOW WL RESULT IN A DRY FCST FOR THE REST OF THE CWA. LO
TEMPS MAY BE TRICKY TNGT...ESPECIALLY OVER THE E. IF THE LO CLDS
LINGERING THERE DSPT THIS EVNG WITH THE PASSING OF THE SFC HI/MORE
ACYC FLOW BEFORE THE SLY FLOW PICKS UP...TEMPS COULD FALL QUICKLY
BEFORE WINDS PICK UP OVERNGT. SUSPECT THE LO CLDS WL BE RESILIENT
ENUF AND INCOMING MID/HI CLDS WL LIMIT THIS EVNG TEMP DROP...SO DID
NOT GO TOO LO WITH FCST MIN TEMPS. INCRSG S WINDS/MORE CLDS WL
LIKELY BRING RISING TEMPS OVERNGT.
WED...STEADY/GUSTY S SLOWLY VEERING SW LLVL FLOW IS FCST TO SLOWLY
INCRS MSTR DEPTH THRU THE DAY. IN CONCERT WITH SOME WEAK DEEP LYR
QVECTOR CNVGC ASSOCIATED WITH THE LARGER SCALE WAA/ISENTROPIC
ASCENT...THERE MAY BE SOME LIGHT RA OR DZ. BUT GENERAL DRYNESS OF
THE FCST AIRMASS IN THE MID LVLS/DGZ AND ONLY WEAK FORCING SUGGESTS
ANY PCPN WL BE ON THE LGT SIDE. SO MODEL QPF IS RATHER LGT AND
SPOTTY AND FOCUSED MAINLY AWAY FM THE DOWNSLOPE AREAS NEAR LK SUP.
ALTHOUGH THE CLDS WL HOLD DOWN MAX TEMPS...READINGS NOT FAR FM 40 WL
STILL BE WELL ABOVE NORMAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 416 PM EST TUE NOV 24 2015
BY 00Z THURSDAY THE INITIAL N END OF THE ELONGATED SFC TROUGH WILL
BE SET UP FROM N ONTARIO THROUGH THE W HALF OF LAKE
SUPERIOR...EXTENDING IN THE FORM OF A COLD FRONT DOWN THROUGH KS TO
THE S LOW OVER NE NM. THE NAM IS HINTING AT SOME ENHANCEMENT TO THE
PRECIP ACROSS THE N CENTRAL HIGHER TERRAIN AREAS FROM BIG BAY
THROUGH NEGAUNEE/ISHPEMING TO GWINN WEDNESDAY EVENING.
THE N END OF THE BROAD 500MBTROUGH STRETCHING FROM N CENTRAL CANADA
DOWN TO THE MAIN LOW MOVING ON SHORE IN OR/N CA THIS AFTERNOON WILL
KEEP A CUT OFF LOW SPINNING OVER THE W THIRD OF THE NATION THROUGH AT
LEAST THE FIRST HALF OF THE UPCOMING WEEKEND.
LOOK FOR THE COLD FRONT TO SWEEP TO THE E HALF OF UPPER MI BY
DAYBREAK THURSDAY. AS THE N END OF THE 500MB TROUGH SHIFTS ACROSS
MANITOBA TO E MT. WILL KEEP THE FREEZING DRIZZLE/DRIZZLE POTENTIAL
GOING OVERNIGHT WEDNESDAY NIGHT THROUGH THURSDAY MORNING...BEFORE
BETTER MOISTURE SNEAKS IN. THURSDAY AFTERNOON AND EVENING WILL BE
THE LARGEST THREAT PERIOD FOR MAINLY CENTRAL AND E UPPER MI...WITH A
SMALL CHANCE OF SLEEP S CENTRAL THURSDAY AFTERNOON INTO THE
EARLY EVENING HOURS. ELSEWHERE...SNOW SHOULD BE ON THE
DOORSTEP...CHANGING OVER TO ALL SNOW W THURSDAY MORNING AND HOLDING
OFF FAR E UNTIL THURSDAY EVENING. THE CANADIAN AND ECMWF ARE STILL
MORE ROBUST ON THE W PRECIP PUSH. THE OVERALL PICTURE IS
SIMILAR...MAKING THE FCST TRICKY. THE 12Z ECMWF DID COME IN WITH A
LITTLE LESS PRECIP THOUGH OVER CENTRAL UPPER MI...IN SOME PLACES
CLOSE TO 0.2IN LESS. A BLENDED SOLUTION STILL LOOKS GOOD...WITH A
SLANT TOWARDS THE ECMWF SOLUTION AS IT BEGINS TO COME MORE IN LINE
WITH THE GFS.
THE 500MB TROUGH AND COLDEST 850MB TEMPS OF -5 TO -8C TRAVERSES
UPPER MI FRIDAY...WITH THE GFS STILL THE MOST PROGRESSIVE. THE
FAVORABLE N-NNW SNOW WINDS OFF LAKE SUPERIOR SLOWLY SWITCH TO A MORE
W DIRECTION LATER FRIDAY WITH SNOW ENDING W TO E AS HIGH PRESSURE
BUILDS INTO THE REGION.
THE LARGE 500MB LOW OVER THE W U.S. BEGINS TO SHIFT ACROSS THE N AND
CENTRAL PLAINS LATE SUNDAY THROUGH MONDAY...BEFORE MOVING TO THE
UPPER GREAT LAKES TUESDAY. THE GFS IS MORE PROGRESSIVE THAN THE
ECMWF...WITH A NEARLY STACKED SFC-500MB LOW SPINNING ACROSS THE N/WI
BORDER BY 12Z TUESDAY. THE 00Z ECMWF SOLUTION WAS MORE WRAPPED UP
BUT WITH LESS MOISTURE AVAILABLE AND A WEAKER SFC REFLECTION. THE
SFC HIGH REMAINED STRONG OVER THE REGION THROUGH...WITH 12-24 HOUR
SLOWER RESPONSE COMPARED TO THE GFS. THE 12Z ECMWF CAME IN MUCH MORE
IN LINE WITH THE 12Z GFS WITH THE NEXT SFC LOW OVERHEAD AT 12Z
MONDAY. WILL SEE IF THIS BETTER CONSISTENCY CAN HOLD UP THROUGH THE
NEXT COUPLE OF DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1235 AM EST WED NOV 25 2015
AN INCREASING S WIND TONIGHT WILL RESULT IN IN LLWS OVERNIGT AND
DRAW MOISTER AIR INTO THE WESTERN GREAT LAKES. THIS WILL BRING
DETERIORATING CONDITIONS IN THE PRESENCE OF NOCTURNAL COOLING. THE
BEST CHANCE FOR A SUSTAINED PERIOD OF LOWER END MVFR TO IFR
CONDITIONS WILL BE AT KSAW...WHERE THE EXPECTED SSE WIND WILL
UPSLOPE. DOWNSLOPE NATURE OF THE EXPECTED FLOW AT KIWD AND KCMX MAKE
IFR CIGS LESS LIKELY. MVFR CONDITIONS ARE LIKELY TO DROP TO IFR WED
EVENING AS ADDITIONAL MOISTURE ALONG WITH SOME LIGHT RAIN OR DRIZZLE
MOVE IN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 332 PM EST TUE NOV 24 2015
RELATIVELY LIGHT WINDS THIS EVENING WILL BECOME S AND INCREASE
QUICKLY OVERNIGHT UNDER TIGHTENING PRES GRADIENT BETWEEN BUILDING HI
PRES TO THE E AND FALLING PRES IN THE PLAINS. OPTED TO UPGRADE GALE
WATCH FOR MUCH OF THE E HALF TO A WARNING FOR WED INTO THE
EVENING...WHEN THE GRADIENT/WINDS WILL DIMINISH SUFFICIENTLY. EXPECT
A WIND SHIFT TO THE NNW AFTER A COLD FRONT CROSSES THE LAKE ON WED
NIGHT INTO EARLY THU. THE TIGHT PRES GRADIENT AHEAD OF TRAILING HI
PRES WILL LEAD TO WINDS UP TO 30 KTS AND PERHAPS SOME MARGINAL GALE
FORCE WINDS INTO THU NIGHT. WINDS WILL THEN SLOWLY DIMINISH INTO FRI
AS THIS HI PRES EDGES CLOSER. ALTHOUGH W WINDS COULD INCREASE UP TO
25-30KT AGAIN ON SAT UNDER A TIGHTENING GRADIENT BETWEEN THE HI
CENTERED JUST TO THE SW AND ANOTHER LO PRES TROF SWINGING THRU
NORTHERN ONTARIO...A WEAKER GRADIENT AND LIGHTER WINDS ARE EXPECTED
TO PREVAIL ON SUN AFTER THE TROF EXITS INTO QUEBEC AND THE HI PRES
RIDGE BUILDS BACK TOWARD THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 AM THIS MORNING TO 10 PM EST THIS EVENING
FOR LSZ266-267.
LAKE MICHIGAN...
GALE WARNING FROM 10 AM THIS MORNING TO 1 AM EST THURSDAY FOR
LMZ248-250.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
559 AM CST WED NOV 25 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CST WED NOV 25 2015
SOME SIGNIFICANT CHANGES WERE MADE TO THE FORECAST FOR TODAY AND
TONIGHT...WITH IT NOT LOOKING TO BE AS WET /ESPECIALLY TONIGHT/ OR
AS FOGGY AS WE WERE ADVERTISING. IN ADDITION...FROM THE AVIATION END
OF THINGS...CLOUD HEIGHTS LOOK TO BE QUITE A BIT HIGHER THAN
ORIGINALLY ANTICIPATED AS WELL.
TEMPERATURES OVERNIGHT HAVE REMAINED FAIRLY STEADY WITH A PERSISTENT
SE WIND BLOWING AND A HEALTHY AMOUNT OF CIRRUS OVERHEAD. AN INVERTED
THROUGH AT 3AM EXTENDED FROM A LEE SIDE LOW OVER CO NORTHEAST TO THE
NW CORNER OF MN. THOUGH THERE IS EXTENSIVE STRATUS IN THE MOIST
SOUTHERLY FLOW AHEAD OF THE LOW/TROUGH...THIS STRATUS HAS BEEN
FAIRLY HIGH BASED...WITH ALL OF IOWA STILL AT OR ABOVE 4K FT...EVEN
AT 3AM. THIS IS PROBABLY THE BIGGEST REASON FOR STARTING TO BACK
AWAY FROM THE HIGH POPS AND PROLONGED DRIZZLE MENTION WE HAD. TO GET
DZ...YOU WANT TO SEE CLOUDS UNDER AT LEAST 1K FT...500 FT IS EVEN
BETTER...BUT LOWEST STRATUS DOWN IN KS IS ONLY DOWN AROUND 2K FT. 1
KM REFLECTIVITY FROM SEVERAL OF THE CAMS HAS SPORADIC RETURNS AHEAD
OF THE FRONT TODAY...THOUGH THAT IS MORE OF A REFLECTION OF
SATURATION AT THIS LEVEL AS OPPOSED TO PRECIP GENERATION...AS
EVIDENCED BY THE LACK OF RETURNS WITH THE INSTANTANEOUS PRECIP RATE
FIELD FROM THE HOPWRF. REALLY...IT DOES NOT LOOK LIKE THE DEEPER
MOISTURE AND FORCING FINALLY HOOKUP UNTIL THE MOISTURE PLUME AT H85
IS OFF TO THE EAST OF THE MPX AREA. THIS IDEA IS HIGHLIGHTED WELL BY
PRETTY MUCH ALL MEMBERS OF THE NCAR ENSEMBLE WRF...WHICH SHOW
SCATTERED SHOWERS DEVELOPING LATE THIS AFTERNOON EAST OF THE MPX
AREA. FOR TONIGHT...WITH THE FRONTAL BOUNDARY WORKING EAST OF THE
AREA...THAT WILL FURTHER HELP SUPPRESS OUR PRECIP POTENTIAL...WITH
THE MAIN PRECIP SHIELD WITH OUR POTENTIAL THANKSGIVING DAY WINTRY
PRECIP NOT ARRIVING UNTIL AFTER 12Z THURSDAY.
FOR TEMPERATURES...WITH NOT AS MUCH LOW STRATUS EXPECTED TODAY...
COMBINED WITH A HIGH STARTING POINT THIS MORNING AND THE OVER
ACHIEVING TEMPERATURES THE PAST COUPLE OF DAYS...DID BOOST HIGHS
INTO THE MID/UPPER 40S FOR EAST OF THE BOUNDARY THIS AFTERNOON.
TONIGHT...WE SHOULD SEE A PRETTY GOOD GRADIENT IN LOWS...WITH STRONG
CAA SENDING LOWS DOWN CLOSE TO 20 IN WRN MN...WITH THE LATER ARRIVAL
OF THE COLD AIR AND CONTINUED CLOUD COVER KEEPING THE EAST END OF
THE MPX AREA UP ABOVE FREEZING ONCE AGAIN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CST WED NOV 25 2015
THE THANKSGIVING SNOW EVENT REMAINS THE MAIN FORECAST CONCERN IN
THE LONG TERM. EVENTUALLY A CUT-OFF UPPER LOW WILL DRIFT NORTHEAST
AND GET CAUGHT UP IN THE WESTERLIES. THIS WILL BRING PRECIP TO THE
AREA EARLY NEXT WEEK...BUT WE CAN REFINE THE FORECASTS FOR THIS
EVENT FRI/SAT/SUN. THURSDAYS POTENTIAL TRAVEL IMPACTS REMAIN THE
FOCUS THIS MORNING.
WE WONT HAVE ANY WINTER WEATHER HEADLINES LOCALLY THIS MORNING DUE
TO UNCERTAINTY AND ALSO BASED ON THE FACT THAT OUR SNOW FORECAST
IS IN THE 1-3 INCH RANGE ACROSS THE EASTERN FORECAST AREA.
TODAY...HOWEVER...WE ARE GOING TO HAVE AN INTERNAL CONFERENCE CALL
WITH SURROUNDING NWS OFFICES...SO THE DAY SHIFT WILL ASSESS THE
WEATHER SITUATION AND COLLABORATE ANY WINTER WEATHER HEADLINES IF
NEEDED.
THE 00Z-06Z GUIDANCE HASNT DEVIATED A WHOLE LOT FROM YESTERDAYS
MODEL OUTPUT. THE GFS/ECMWF HAVE SHIFTED THE QPF PATTERN ABOUT A
COUNTY FARTHER SOUTHEAST...AND WITH THE SLOWLY EVOLVING POSITIVE
TILT TO THE SYSTEM AND POTENTIAL FOR CONVECTIVE ELEMENTS SOUTH OF
THE FORECAST AREA...WE REALLY CANT ENVISION A DRAMATIC SHIFT TO
THE NORTH. THIS MEANS THE ENTIRE WESTERN HALF OF THE FORECAST AREA
/INCLUDING ST. CLOUD...REDWOOD FALLS AND EVEN THE NORTHWEST TC
METRO/ WILL LIKELY END UP WITH LITTLE SNOW OUT OF THIS SYSTEM. WE
THINK THE P-TYPE FOR MOST OF EAST CENTRAL AND SOUTH CENTRAL MN
WILL BE SNOW. THEREFORE...WE ARE FAIRLY CONFIDENT IN THE 1-3" OF
SNOW FORECASTED FOR AREAS LIKE MANKATO...THE TWIN CITIES
METRO...AND FAR WEST CENTRAL WI. THE BIGGER CONCERN REMAINS FOR
AREAS JUST TO THE EAST OF THIS LINE - THIS INCLUDES AREAS SUCH AS
ALBERT LEA...RED WING AND EAU CLAIRE. THE P-TYPE IS MORE IN
QUESTION IN THESE AREAS...BUT IF THERE IS A QUICKER CHANGE OVER TO
SNOW...THAN THE 1-3 INCHES IN THE FORECAST WONT BE ENOUGH AND
AMOUNTS COULD BE CLOSER TO 5 OR 6 INCHES. THE NAM PRODUCES SNOW
AMOUNTS OF 5-7 INCHES IN THE EASTERN FORECAST AREA...BUT IT IS
ALSO A STRONGER/WESTERN AND SLOWER OUTLIER COMPARED TO THE
GFS/ECMWF/GEM.
AS MENTIONED IN PREVIOUS DISCUSSIONS...THE MOISTURE AND
TEMPERATURE GRADIENT IN THE EASTERN FORECAST AREA IS
IMPRESSIVE...BUT THE FGEN ISNT IS AS GOOD AS YOU MIGHT THINK...DUE
TO WEAKER CONVERGENCE. HOWEVER...THESE AREAS IN THE FAR EASTERN
FORECAST AREA SHOULD END UP JUST WEST OF THE RAIN/SNOW LINE BY
00Z FRIDAY AND THAT`S USUALLY A GOOD SPOT TO BE FOR MELTING
INDUCED FRONTOGENESIS. SO...THERE COULD BE A 2-4 HOUR WINDOW LATE
THURSDAY AFTERNOON OR THURSDAY EVENING WITH A QUICK CHANGE OVER TO
SNOW AND MODERATE TO HEAVY SNOW BASED ON THE ENHANCED LIFT AND
SLIGHT SURFACE COOLING. NOW THE SURFACE TEMPS IN WESTERN WI AND
FAR EASTERN MINNESOTA WILL BE NEAR THE FREEZING MARK AND WHILE THE
900MB-850MB TEMPS ARE COLD...THE WHOLE SOUNDING ISNT VERY COLD AND
THE DENDRITE GROWTH ZONE IS ACTUALLY HIGHER THAN THE BEST LIFT AND
FGEN...THIS ZONE IS ALSO FAIRLY NARROW. AS A RESULT...WE DONT
EXPECT HIGH SNOW RATIOS...PROBABLY MORE LIKE 8-10:1 IN WI AND FAR
EASTERN MN.
IN SUMMARY...THERE WILL BE SNOW IN EASTERN AND SOUTHERN MN...AND
WE DONT EXPECT MAJOR IMPACTS GIVEN OUR CONFIDENCE IN THE 1-3"
TOTALS. HOWEVER...BIGGER POTENTIAL IMPACTS ARE POSSIBLE IN THE
ALBERT LEA...RED WING AND EAU CLAIRE AREAS WHERE A QUICKER CHANGE
OVER TO SNOW COULD LEAD TO AMOUNTS THAT APPROACH 6 INCHES...OR A
HEALTHY COMBINATION OF SLEET AND SNOW.
THE WEEKEND LOOKS DRY WITH NEAR NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 555 AM CST WED NOV 25 2015
DESPITE MOIST SE FLOW THROUGH THE NIGHT...CIGS HAVE BEEN SLOW TO
DESCEND...THOUGH WE ARE STARTING TO SEE SOME MVFR CIGS COME OUT
OF NW IOWA THAT WILL SPREAD N/NE THIS MORNING. FAVORED THE HRRR
FOR BRINGING LOWER CIGS INTO TAFS..THOUGH DID NOT GO QUITE AS LOW
AS WHAT THE HRRR HAS...PREFERING TO KEEP CIGS TODAY MAINLY MVFR
BASED ON THE LACK OF IFR CIGS TO THE SOUTH. BESIDE THESE CLOUDS TO
THE SOUTH...AS THE FRONT APPROACHING WRN MN MOVES THROUGH...WE
WILL SEE IFR/MVFR CIGS DROP SOUTH OUT OF NODAK...THOUGH THOSE ARE
DESTINED TO IMPACT MPX TERMINALS THIS AFTERNOON INTO TONIGHT. FOR
PRECIP...AGAIN FOLLOWED THE IDEA OF THE HRRR WITH A FEW SHOWERS
DEVELOPING AHEAD OF THE FRONT THIS AFTERNOON FOR ERN MN AND WRN
WI...THOUGH NOT EXPECTING MUCH OUT OF THIS.
KMSP...WE WILL SEE CIGS SLOWLY LOWER THROUGH THE DAY AS THE COLD
FRONT MOVES IN FROM THE WEST. TIMING FOR THE FROPA STILL LOOKS
GOOD AROUND 23Z WITH WINDS GRADUALLY VEERING FROM THE SOUTH OVER
TO THE NW BETWEEN 18Z AND 3Z. MAY SEE CIGS DROP BELOW 018 BRIEFLY
WITH THE FROPA...BUT NOT ANTICIPATING CIGS BELOW THAT LEVEL FOR
GOOD UNTIL WE GET BEHIND THE FRONT. FOR THE END OF THE TAF
PERIOD...SNOW WILL BE APPROACHING MSP FROM THE SOUTH. STILL A FAIR
AMOUNT OF SPREAD WITH HOW QUICKLY SNOW GETS HERE...WITH THE GFS
GOING SHORTLY AFTER 12Z THU AND THE NAM NOT UNTIL AFTER 18Z. FOR
NOW...WENT WITH SOMETHING IN BETWEEN AND THIS CAN BE REFINED
THROUGH THE DAY TODAY.
/OUTLOOK FOR KMSP/
THU...IFR WITH SN. WINDS N 10-20 KTS.
FRI...VFR. WINDS NNW 5-10 KTS.
SAT...VFR. WINDS SW 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1144 AM CST WED NOV 25 2015
.UPDATE...ADDED AVIATION DISCUSSION.
&&
.AVIATION...EXPECT MAINLY VFR CATEGORY CIGS FOR THIS AFTERNOON
THROUGH THE EVENING HOURS. THIS SHOULD CHANGE TO MVFR WHEN THE
POTENTIAL FOR 1000-1500 FT CIGS INCREASES LATER TONIGHT INTO THE PRE-
DAWN HOURS THURSDAY. /27/
&&
.PREV DISCUSSION... /ISSUED 949 AM CST WED NOV 25 2015/
UPDATE...VERY PLEASANT CONDITIONS OCCURRING THIS THANKSGIVING EVE AS
TEMPERATURES ARE RUNNING ABOUT 10 DEGREES WARMER THAN 24 HOURS AGO.
THIS IS THANKS IN PART TO THE SOUTHERLY FLOW THAT HAS RETURNED TO
THE REGION AS A RESULT OF BEING ON THE WESTERN PERIPHERY OF A SFC
HIGH CENTERED OVER THE COAST OF MAINE. SOME CLOUD COVER WILL
INCREASE TODAY BUT SUNNY SKIES WILL MOSTLY PREVAIL AND HELP
TEMPERATURES INCREASE INTO THE UPPER 60S/LOWER 70S AS AN UPPER RIDGE
BUILDS ACROSS THE REGION. GOING FORECAST IS IN DECENT SHAPE AND MADE
A FEW ADJUSTMENTS TO INCREASE HIGH TEMPERATURES IN A COUPLE OF
LOCATIONS THAT ARE ALREADY WARMING QUICKLY. ALSO MADE SOME
ADJUSTMENTS TO HOURLY TEMPS AND SKY COVER. OVERALL...IT SHOULD BE A
RATHER FABULOUS TRAVEL DAY FOR MANY ACROSS THE ARKLAMISS AND MOST OF
THE SOUTHEAST UNITED STATES. /28/
PREV DISCUSSION... /ISSUED 420 AM CST WED NOV 25 2015/
DISCUSSION...
TODAY THROUGH THURSDAY NIGHT...
A DEEP LONGWAVE TROUGH OVER THE WESTERN CONUS WILL INDUCE AN
ANOMALOUS DOWNSTREAM RIDGE OVER THE CENTRAL GULF COAST REGION AS WE
MOVE INTO LATTER PORTIONS OF THE WEEK. STRONG MID LEVEL SUBSIDENCE
WILL GREATLY LIMIT RAIN CHANCES...BUT LOW LEVEL MOISTURE TRANSPORT
COULD BE SUFFICIENT TO PRODUCE ISOLATED SHOWER ACTIVITY OVER NE LA/SW
MS THIS AFTN PER RECENT HRRR AND OTHER HIGH RES NEAR TERM GUIDANCE.
THIS PATTERN WILL BRING MUCH MILDER LOW TEMPERATURES TO THE
ARKLAMISS WITH READINGS EXPECTED TO BE ~ 15 DEG F ABOVE CLIMATE
NORMALS. HIGH TEMPERATURES WILL BE WARMER THAN RECENTLY
OBSERVED...BUT THE WARMTH SHOULD BE TEMPERED SOME BY INCREASING
STRATOCUMULUS COVERAGE AND ESE FLOW EMANATING FROM A SLIGHTLY COOLER
AIRMASS WEDGING AROUND THE SOUTHERN APPALACHIANS. STILL EXPECT HIGHS
TO BE 5 TO 10 DEG ABOVE CLIMATOLOGY ON AVERAGE...BUT A FEW COOLER
POCKETS WILL BE POSSIBLE WHERE CLOUD COVER IS MORE PERSISTENT...
ESPECIALLY OVER EAST CENTRAL MS. /EC/
LONG TERM (FRIDAY THROUGH NEXT TUESDAY)...THE PRIMARY CONCERN IN THE
EXTENDED IS PRECIP TIMING FOR LATE THIS WEEK INTO NEXT WEEK.
AT THE BEGINNING OF THE PERIOD, AN UPPER TROUGH EXTENDING FROM
HUDSON BAY INTO THE NORTHERN PLAINS WILL BE IN THE PROCESS OF
CUTTING OFF AN UPPER LOW OVER CALIFORNIA/NEVADA. A SLOW MOVING COLD
FRONT WILL BE POSITIONED FROM THE GREAT LAKES THROUGH THE MID
MISSISSIPPI VALLEY TO THE RED RIVER VALLEY, WITH CONSIDERABLE RAIN
ONGOING IN THOSE AREAS.
HEADING INTO THE WEEKEND, CONSIDERABLE TIMING/PATTERN INCONGRUITIES
REMAIN AMONG OP/ENSEMBLE MODEL GUIDANCE, THUS DID NOT STRAY FAR FROM
ENSEMBLE MEAN AND MODEL BLEND POPS. AT THIS TIME IT APPEARS
ELONGATED MID LEVEL RIDGING AND (AT LEAST IN THE EASTERN HALF OF THE
AREA) WEDGING SURFACE HIGH PRESSURE WILL HELP DEFLECT PRECIP LARGELY
TO THE NORTHWEST THROUGH FRIDAY - MEANING DRY CONDITIONS FOR POST-
THANKSGIVING BARGAIN HUNTERS. SUBTLE IMPULSES EMBEDDED WITHIN AN
UPPER LEVEL SOUTHWESTERLY FLOW REGIME WILL ULTIMATELY ACT TO LOWER
HEIGHTS INTO THE WEEKEND. AS A RESULT, RAIN CHANCES WILL BEGIN TO
CLIMB, ESPECIALLY IN THE NORTHWEST BY SATURDAY WITH MORE WIDESPREAD
COVERAGE POSSIBLE SUNDAY AS A STRONGER DISTURBANCE IS EXPECTED TO
MOVE THROUGH.
THROUGH THE WEEKEND INTO EARLY NEXT WEEK, THE CUTOFF UPPER LOW WILL
MIGRATE INTO THE UPPER PLAINS. AS THE UPPER JET REMAINS NORTH OF THE
REGION ALMOST PARALLEL TO THE SURFACE FRONT, THE FRONT WILL ONLY
MEANDER INTO THE AREA THROUGH EARLY NEXT WEEK, GRADUALLY WEAKENING
WITH THE LOSS OF UPPER SUPPORT. HOWEVER, ABOVE AVERAGE PW IN THE 1
TO 1.5 INCH RANGE WILL STILL EXIST ACROSS THE AREA, KEEPING THE
POSSIBILITY FOR SCATTERED SHOWERS AROUND INTO EARLY NEXT WEEK.
THROUGHOUT THE ENTIRE PERIOD, ONLY ISOLATED TO LOWER END CHANCE POPS
WILL BE INCLUDED ACROSS THE PINE BELT AS THE FRONT LOOKS TO REMAIN
FARTHEST AWAY FROM THIS AREA. GUIDANCE CONTINUES TO SHOW LITTLE TO
NO INSTABILITY WITH THIS SYSTEM, THUS WE WILL CONTINUE TO KEEP
THUNDER OUT OF THE FORECAST. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 70 54 70 57 / 0 2 5 4
MERIDIAN 67 48 70 52 / 0 1 3 4
VICKSBURG 69 55 74 59 / 0 4 6 7
HATTIESBURG 71 53 72 55 / 0 4 7 4
NATCHEZ 69 57 73 60 / 0 4 6 7
GREENVILLE 67 54 70 59 / 0 3 9 9
GREENWOOD 68 52 70 57 / 0 2 10 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
27/28/EC/DL/
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
949 AM CST WED NOV 25 2015
.UPDATE...VERY PLEASANT CONDITIONS OCCURRING THIS THANKSGIVING EVE AS
TEMPERATURES ARE RUNNING ABOUT 10 DEGREES WARMER THAN 24 HOURS AGO.
THIS IS THANKS IN PART TO THE SOUTHERLY FLOW THAT HAS RETURNED TO
THE REGION AS A RESULT OF BEING ON THE WESTERN PERIPHERY OF A SFC
HIGH CENTERED OVER THE COAST OF MAINE. SOME CLOUD COVER WILL
INCREASE TODAY BUT SUNNY SKIES WILL MOSTLY PREVAIL AND HELP
TEMPERATURES INCREASE INTO THE UPPER 60S/LOWER 70S AS AN UPPER RIDGE
BUILDS ACROSS THE REGION. GOING FORECAST IS IN DECENT SHAPE AND MADE
A FEW ADJUSTMENTS TO INCREASE HIGH TEMPERATURES IN A COUPLE OF
LOCATIONS THAT ARE ALREADY WARMING QUICKLY. ALSO MADE SOME
ADJUSTMENTS TO HOURLY TEMPS AND SKY COVER. OVERALL...IT SHOULD BE A
RATHER FABULOUS TRAVEL DAY FOR MANY ACROSS THE ARKLAMISS AND MOST OF
THE SOUTHEAST UNITED STATES. /28/
&&
.PREV DISCUSSION... /ISSUED 420 AM CST WED NOV 25 2015/
DISCUSSION...
TODAY THROUGH THURSDAY NIGHT...
A DEEP LONGWAVE TROUGH OVER THE WESTERN CONUS WILL INDUCE AN
ANOMALOUS DOWNSTREAM RIDGE OVER THE CENTRAL GULF COAST REGION AS WE
MOVE INTO LATTER PORTIONS OF THE WEEK. STRONG MID LEVEL SUBSIDENCE
WILL GREATLY LIMIT RAIN CHANCES...BUT LOW LEVEL MOISTURE TRANSPORT
COULD BE SUFFICIENT TO PRODUCE ISOLATED SHOWER ACTIVITY OVER NE LA/SW
MS THIS AFTN PER RECENT HRRR AND OTHER HIGH RES NEAR TERM GUIDANCE.
THIS PATTERN WILL BRING MUCH MILDER LOW TEMPERATURES TO THE
ARKLAMISS WITH READINGS EXPECTED TO BE ~ 15 DEG F ABOVE CLIMATE
NORMALS. HIGH TEMPERATURES WILL BE WARMER THAN RECENTLY
OBSERVED...BUT THE WARMTH SHOULD BE TEMPERED SOME BY INCREASING
STRATOCUMULUS COVERAGE AND ESE FLOW EMANATING FROM A SLIGHTLY COOLER
AIRMASS WEDGING AROUND THE SOUTHERN APPALACHIANS. STILL EXPECT HIGHS
TO BE 5 TO 10 DEG ABOVE CLIMATOLOGY ON AVERAGE...BUT A FEW COOLER
POCKETS WILL BE POSSIBLE WHERE CLOUD COVER IS MORE PERSISTENT...
ESPECIALLY OVER EAST CENTRAL MS. /EC/
LONG TERM (FRIDAY THROUGH NEXT TUESDAY)...THE PRIMARY CONCERN IN THE
EXTENDED IS PRECIP TIMING FOR LATE THIS WEEK INTO NEXT WEEK.
AT THE BEGINNING OF THE PERIOD, AN UPPER TROUGH EXTENDING FROM
HUDSON BAY INTO THE NORTHERN PLAINS WILL BE IN THE PROCESS OF
CUTTING OFF AN UPPER LOW OVER CALIFORNIA/NEVADA. A SLOW MOVING COLD
FRONT WILL BE POSITIONED FROM THE GREAT LAKES THROUGH THE MID
MISSISSIPPI VALLEY TO THE RED RIVER VALLEY, WITH CONSIDERABLE RAIN
ONGOING IN THOSE AREAS.
HEADING INTO THE WEEKEND, CONSIDERABLE TIMING/PATTERN INCONGRUITIES
REMAIN AMONG OP/ENSEMBLE MODEL GUIDANCE, THUS DID NOT STRAY FAR FROM
ENSEMBLE MEAN AND MODEL BLEND POPS. AT THIS TIME IT APPEARS
ELONGATED MID LEVEL RIDGING AND (AT LEAST IN THE EASTERN HALF OF THE
AREA) WEDGING SURFACE HIGH PRESSURE WILL HELP DEFLECT PRECIP LARGELY
TO THE NORTHWEST THROUGH FRIDAY - MEANING DRY CONDITIONS FOR POST-
THANKSGIVING BARGAIN HUNTERS. SUBTLE IMPULSES EMBEDDED WITHIN AN
UPPER LEVEL SOUTHWESTERLY FLOW REGIME WILL ULTIMATELY ACT TO LOWER
HEIGHTS INTO THE WEEKEND. AS A RESULT, RAIN CHANCES WILL BEGIN TO
CLIMB, ESPECIALLY IN THE NORTHWEST BY SATURDAY WITH MORE WIDESPREAD
COVERAGE POSSIBLE SUNDAY AS A STRONGER DISTURBANCE IS EXPECTED TO
MOVE THROUGH.
THROUGH THE WEEKEND INTO EARLY NEXT WEEK, THE CUTOFF UPPER LOW WILL
MIGRATE INTO THE UPPER PLAINS. AS THE UPPER JET REMAINS NORTH OF THE
REGION ALMOST PARALLEL TO THE SURFACE FRONT, THE FRONT WILL ONLY
MEANDER INTO THE AREA THROUGH EARLY NEXT WEEK, GRADUALLY WEAKENING
WITH THE LOSS OF UPPER SUPPORT. HOWEVER, ABOVE AVERAGE PW IN THE 1
TO 1.5 INCH RANGE WILL STILL EXIST ACROSS THE AREA, KEEPING THE
POSSIBILITY FOR SCATTERED SHOWERS AROUND INTO EARLY NEXT WEEK.
THROUGHOUT THE ENTIRE PERIOD, ONLY ISOLATED TO LOWER END CHANCE POPS
WILL BE INCLUDED ACROSS THE PINE BELT AS THE FRONT LOOKS TO REMAIN
FARTHEST AWAY FROM THIS AREA. GUIDANCE CONTINUES TO SHOW LITTLE TO
NO INSTABILITY WITH THIS SYSTEM, THUS WE WILL CONTINUE TO KEEP
THUNDER OUT OF THE FORECAST. /DL/
AVIATION...INCREASING MOISTURE TRANSPORT IS BRINGING AN END TO A
LONG STREAK OF MOSTLY CLEAR SKIES WITH 4000-5000 FT CIGS ALREADY
DEVELOPING OVER THE HBG-MEI CORRIDOR EARLY THIS MORNING...BUT STILL
EXPECT MAINLY VFR CATEGORY CIGS AS WE GO THROUGH TODAY INTO THIS
EVENING. THIS SHOULD CHANGE EARLY THURSDAY MORNING WHEN THE POTENTIAL
FOR 1000-1500 FT CIGS INCREASES DURING THE PRE-DAWN HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 70 54 70 57 / 0 2 5 4
MERIDIAN 67 48 70 52 / 0 1 3 4
VICKSBURG 69 55 74 59 / 0 4 6 7
HATTIESBURG 71 53 72 55 / 0 4 7 4
NATCHEZ 69 57 73 60 / 0 4 6 7
GREENVILLE 67 54 70 59 / 0 3 9 9
GREENWOOD 68 52 70 57 / 0 2 10 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
28/CME/EC/DL
AREA FORECAST DISCUSSION
NWS JACKSON MS
420 AM CST WED NOV 25 2015
.DISCUSSION...
TODAY THROUGH THURSDAY NIGHT...
A DEEP LONGWAVE TROUGH OVER THE WESTERN CONUS WILL INDUCE AN
ANOMALOUS DOWNSTREAM RIDGE OVER THE CENTRAL GULF COAST REGION AS WE
MOVE INTO LATTER PORTIONS OF THE WEEK. STRONG MID LEVEL SUBSIDENCE
WILL GREATLY LIMIT RAIN CHANCES...BUT LOW LEVEL MOISTURE TRANSPORT
COULD BE SUFFICIENT TO PRODUCE ISOLATED SHOWER ACTIVITY OVER NE LA/SW
MS THIS AFTN PER RECENT HRRR AND OTHER HIGH RES NEAR TERM GUIDANCE.
THIS PATTERN WILL BRING MUCH MILDER LOW TEMPERATURES TO THE
ARKLAMISS WITH READINGS EXPECTED TO BE ~ 15 DEG F ABOVE CLIMATE
NORMALS. HIGH TEMPERATURES WILL BE WARMER THAN RECENTLY
OBSERVED...BUT THE WARMTH SHOULD BE TEMPERED SOME BY INCREASING
STRATOCUMULUS COVERAGE AND ESE FLOW EMANATING FROM A SLIGHTLY COOLER
AIRMASS WEDGING AROUND THE SOUTHERN APPALACHIANS. STILL EXPECT HIGHS
TO BE 5 TO 10 DEG ABOVE CLIMATOLOGY ON AVERAGE...BUT A FEW COOLER
POCKETS WILL BE POSSIBLE WHERE CLOUD COVER IS MORE PERSISTENT...
ESPECIALLY OVER EAST CENTRAL MS. /EC/
LONG TERM (FRIDAY THROUGH NEXT TUESDAY)...THE PRIMARY CONCERN IN THE
EXTENDED IS PRECIP TIMING FOR LATE THIS WEEK INTO NEXT WEEK.
AT THE BEGINNING OF THE PERIOD, AN UPPER TROUGH EXTENDING FROM
HUDSON BAY INTO THE NORTHERN PLAINS WILL BE IN THE PROCESS OF
CUTTING OFF AN UPPER LOW OVER CALIFORNIA/NEVADA. A SLOW MOVING COLD
FRONT WILL BE POSITIONED FROM THE GREAT LAKES THROUGH THE MID
MISSISSIPPI VALLEY TO THE RED RIVER VALLEY, WITH CONSIDERABLE RAIN
ONGOING IN THOSE AREAS.
HEADING INTO THE WEEKEND, CONSIDERABLE TIMING/PATTERN INCONGRUITIES
REMAIN AMONG OP/ENSEMBLE MODEL GUIDANCE, THUS DID NOT STRAY FAR FROM
ENSEMBLE MEAN AND MODEL BLEND POPS. AT THIS TIME IT APPEARS
ELONGATED MID LEVEL RIDGING AND (AT LEAST IN THE EASTERN HALF OF THE
AREA) WEDGING SURFACE HIGH PRESSURE WILL HELP DEFLECT PRECIP LARGELY
TO THE NORTHWEST THROUGH FRIDAY - MEANING DRY CONDITIONS FOR POST-
THANKSGIVING BARGAIN HUNTERS. SUBTLE IMPULSES EMBEDDED WITHIN AN
UPPER LEVEL SOUTHWESTERLY FLOW REGIME WILL ULTIMATELY ACT TO LOWER
HEIGHTS INTO THE WEEKEND. AS A RESULT, RAIN CHANCES WILL BEGIN TO
CLIMB, ESPECIALLY IN THE NORTHWEST BY SATURDAY WITH MORE WIDESPREAD
COVERAGE POSSIBLE SUNDAY AS A STRONGER DISTURBANCE IS EXPECTED TO
MOVE THROUGH.
THROUGH THE WEEKEND INTO EARLY NEXT WEEK, THE CUTOFF UPPER LOW WILL
MIGRATE INTO THE UPPER PLAINS. AS THE UPPER JET REMAINS NORTH OF THE
REGION ALMOST PARALLEL TO THE SURFACE FRONT, THE FRONT WILL ONLY
MEANDER INTO THE AREA THROUGH EARLY NEXT WEEK, GRADUALLY WEAKENING
WITH THE LOSS OF UPPER SUPPORT. HOWEVER, ABOVE AVERAGE PW IN THE 1
TO 1.5 INCH RANGE WILL STILL EXIST ACROSS THE AREA, KEEPING THE
POSSIBILITY FOR SCATTERED SHOWERS AROUND INTO EARLY NEXT WEEK.
THROUGHOUT THE ENTIRE PERIOD, ONLY ISOLATED TO LOWER END CHANCE POPS
WILL BE INCLUDED ACROSS THE PINE BELT AS THE FRONT LOOKS TO REMAIN
FARTHEST AWAY FROM THIS AREA. GUIDANCE CONTINUES TO SHOW LITTLE TO
NO INSTABILITY WITH THIS SYSTEM, THUS WE WILL CONTINUE TO KEEP
THUNDER OUT OF THE FORECAST. /DL/
&&
.AVIATION...INCREASING MOISTURE TRANSPORT IS BRINGING AN END TO A
LONG STREAK OF MOSTLY CLEAR SKIES WITH 4000-5000 FT CIGS ALREADY
DEVELOPING OVER THE HBG-MEI CORRIDOR EARLY THIS MORNING...BUT STILL
EXPECT MAINLY VFR CATEGORY CIGS AS WE GO THROUGH TODAY INTO THIS
EVENING. THIS SHOULD CHANGE EARLY THURSDAY MORNING WHEN THE POTENTIAL
FOR 1000-1500 FT CIGS INCREASES DURING THE PRE-DAWN HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 67 54 70 57 / 7 2 5 4
MERIDIAN 66 48 70 52 / 1 1 3 4
VICKSBURG 69 55 74 59 / 8 4 6 7
HATTIESBURG 71 53 72 55 / 3 4 7 4
NATCHEZ 69 57 73 60 / 12 4 6 7
GREENVILLE 66 54 70 59 / 5 3 9 9
GREENWOOD 65 52 70 57 / 6 2 10 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
/EC/DL/
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
512 PM CST THU NOV 26 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 230 PM CST THU NOV 26 2015
THE WINTER WEATHER ADVISORY FOR FREEZING DRIZZLE WAS CANCELED WITH
THE AFTERNOON FORECAST PACKAGE AS NO ADDITIONAL SNOW OR DRIZZLE
ACCUMULATIONS ARE EXPECTED.
THE PRECIPITATION THREAT CONTINUES TO SHIFT SOUTH AND EAST AS THE
LOWER AND MID LEVELS OF THE TROPOSPHERE UNDERGOES A DRYING TREND.
WILL CONTINUE TO HOLD A MENTION OF LIGHT SNOW ACROSS OUR SOUTHERN
ZONES INTO THE PRE-DAWN HOURS FRIDAY AS BUFR SOUNDINGS REVEAL
SUFFICIENT LIFT AND MODEST MOISTURE. IF SNOW IS REALIZED...
ACCUMULATIONS ARE NOT ANTICIPATED. SKIES HAVE ALREADY BEGUN TO
SCATTER ACROSS NORTHWEST NEBRASKA THIS AFTERNOON...AND THE TREND
SHOULD CONTINUE SOUTH INTO THE OVERNIGHT. COLD TEMPERATURES ARE
FORECAST IN A CLEARING POST COLD FRONT REGIME...WITH SINGLE DIGIT
LOWS ACROSS THE NORTH AND WEST...AND LOWER TEENS ACROSS OUR FAR
EASTERN ZONES AND SOUTHWEST.
WILL CONTINUE TO WATCH THE PROGRESSION OF THE GREAT BASIN UPPER LOW
ON FRIDAY AS IT RELUCTANTLY INCHES EAST TOWARD THE CENTRAL ROCKIES.
CANADIAN HIGH PRESSURE AND DRY AIR WILL DOMINATE THE
PATTERN...LEADING TO COLD HIGHS IN THE MID TO UPPER 20S. BEYOND 12Z
FRIDAY...THE BEST CHANCES OF QPF LOOK TO BE SOUTH AND EAST OF THE
FORECAST AREA...BUT WE CANNOT DISCOUNT A STRAY FLURRY OR TWO ACROSS
OUR SOUTHERN ZONES. AGAIN...NO ACCUMULATIONS ARE EXPECTED IF SNOW
IS REALIZED
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 230 PM CST THU NOV 26 2015
BY FRIDAY EVENING...ONSHORE FLOW ALONG THE TEXAS GULF COAST WILL
BEGIN FEEDING MOISTURE NORTHWARD ONTO THE HIGH PLAINS. ON THE 290K
AND 295K SURFACES...THE MIXING RATIO INCREASES TO 3.5-4G/KG IN SOUTH
CENTRAL NEBRASKA. THE MOISTURE TRANSPORT ON THOSE SURFACES SHOWS
SOME UPGLIDE OVER THE PANHANDLE AND WESTERN SANDHILLS AND THE LIFTED
AIR IS NEARLY SATURATED WITH SATURATION DEFICITS OF LESS THAN 20MB.
BY LATE SUNDAY...THE MOISTURE TRANSPORT IS MORE FROM SOUTHWEST NEW
MEXICO AND SOUTHWEST TEXAS BUT THE AVAILABLE MOISTURE IS STILL AT OR
ABOVE 3G/KG. AS A RESULT...WE WILL KEEP AT LEAST SLIGHT CHANCES OF
PRECIPITATION SATURDAY THROUGH SATURDAY EVENING. THE TEMPERATURE
PROFILES...INCLUDING THE 0-2KM MEAN AND IN THE DENDRITIC LAYER...
ARE FAVORABLE FOR SNOW. THE DENDRITIC LAYER DRIES OUT LATE SATURDAY
NIGHT AND THE PROBABILITY OF SNOW ACCUMULATION DECREASES.
HOWEVER...FORECAST SOUNDINGS STILL FAVOR SOME FORM OF
PRECIPITATION...DRIZZLE OR SNOW GRAINS. WITHOUT FEEDERS FROM
ALOFT...FREEZING DRIZZLE WOULD BE FAVORED BUT THE LIFT IS STRONGER
AND WOULD NOT FAVOR SMALL ENOUGH DROPLETS FOR WATER TO REMAIN AS
SUPER-COOLED LIQUID.
ANOTHER PULSE FROM THE UPPER LOW WILL BRING THE POSSIBILITY OF SNOW
AGAIN SUNDAY NIGHT AND MONDAY. FINALLY...THE UPPER LOW SWINGS
THROUGH MONDAY NIGHT AND ENDS THE CHANCES OF SNOW.
A RIDGE THEN BEGINS BUILDING IN THE WEST AND DRIER AND NOT SO COLD
WEATHER IS LIKELY TUESDAY THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 512 PM CST THU NOV 26 2015
MVFR CIGS ARE EXPECTED TO IMPROVE TO VFR FROM NORTH TO SOUTH THIS
EVENING AT ARCTIC HIGH PRESSURE CONTINUES TO BUILD INTO THE
REGION STABLIZING THE ATM. THE RAP MODEL SUGGESTS MVFR CIGS COULD
LINGER OVERNIGHT AND FRIDAY ACROSS FAR SOUTHWEST NEB. THIS RISK IS
SLIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JACOBS
LONG TERM...SPRINGER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1154 AM CST WED NOV 25 2015
.SYNOPSIS...
ISSUED AT 340 AM CST WED NOV 25 2015
A CONVOLUTED H5 PATTERN CONTINUES TONIGHT ACROSS NOAM WITH A
RIDGE EXTENDING FROM THE NE PACIFIC INTO THE GULF OF ALASKA.
DOWNSTREAM OF THE RIDGE...A TROUGH EXTENDED FROM NRN SASKATCHEWAN
INTO NRN CALIFORNIA. AT THE BASE OF THIS TROUGH...CLOSED LOW
PRESSURE WAS NOTED OVER SWRN OREGON. EAST OF THE TROUGH...A ZONAL
PATTERN EXISTED ACROSS THE REMAINDER OF THE LOWER 48 STATES WITH
THE EXCEPTION OF A PERSISTENT TROUGH WHICH EXTENDED FROM EASTERN
QUEBEC...SWD INTO NEW ENGLAND. AT THE SURFACE...A FRONTAL
BOUNDARY WAS ANCHORED ALONG THE NEBR/SD BORDER AND MARKED THE
LEADING EDGE OF ARCTIC AIR WHICH WAS ENTRENCHED ACROSS THE NRN
PLAINS. READINGS OFF TO THE NORTH WERE IN THE TEENS IN MONTANA
WITH BREEZY NORTHERLY WINDS. SOUTH OF THE FRONT...TEMPERATURES
WERE IN THE 20S TO LOWER 30S WITH THE EXCEPTION SERN NEBRASKA
WHERE 40S AND LOWER 50S WERE COMMON THANKS TO LOW CLOUDS AND A
DECENT INFLUX OF LOW LEVEL MOISTURE PUSHING NORTH FROM EASTERN
KANSAS. FOR NOW...THE STRATUS AND LOW LEVEL MOISTURE HAS STAYED
JUST OFF TO THE EAST AND SOUTHEAST OF THE FORECAST AREA AND
SHOULD REMAIN THERE BASED ON THE LATEST HRRR FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST WED NOV 25 2015
FOR TODAY AND TONIGHT...THE MAIN FORECAST CHALLENGE WILL BE THE
THREAT FOR A WINTRY MIX OF PCPN BEGINNING TONIGHT. FOR
TODAY...THE ARCTIC COLD FRONT WILL PUSH SOUTH THIS MORNING AND
WILL CLEAR MOST OF THE FORECAST AREA BY MID AFTERNOON. HIGHS
TODAY WILL STRUGGLE TO GET OUT OF THE 30S IN THE
NORTHWEST...WHILE 40S ELSEWHERE REMAIN ON TRACK FOR THE FORECAST.
LIKE YESTERDAY...THERE WAS A LARGE DISPARITY IN HIGH TEMPERATURES
BETWEEN THE MAV AND MET GUIDANCE. THE MET SEEMED TOO COOL FOR
NORTH PLATTE TODAY WITH ITS HIGH OF 38 GIVEN THE LATER FRONTAL
TIMING OF EARLY AFTERNOON AND TRENDED THE TEMP FORECAST MORE
TOWARD THE WARMER MAV GUIDANCE. HOWEVER DID NOT GO WITH HIGHS AS
WARM AS THE MAV GUIDANCE SUGGESTS. THIS WAS DUE TO AN ABUNDANCE
OF MID AND HIGH LEVEL CLOUD COVER EXPECTED TODAY IN ADVANCE OF
THE APPG COLD FRONT.
TONIGHT...LOW LEVEL MOISTURE WILL INCREASE BEHIND THE EXITING
COLD FRONT AS A SHIELD OF STRATUS DEVELOPS ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA. ABOVE THE STRATUS...A DECENT DRY LAYER
WILL EXIST WITH SOME WEAK LIFT NOTED JUST ABOVE THE STRATUS LAYER
OVERNIGHT. A THOROUGH EXAMINATION OF BUFKIT FORECAST SOUNDINGS
INDICATES A DECENT SETUP FOR FREEZING DRIZZLE TONIGHT...ROUGHLY
EAST OF A LINE FROM SPRINGVIEW TO OGALLALA. WEST OF THIS
LINE...TEMPERATURE PROFILES IN THE MOIST LAYER SEEM TOO COLD FOR
THE DEVELOPMENT OF FREEZING DRIZZLE AND HAVE OPTED FOR A MENTION
OF SNOW AS THERE IS SOME INDICATION OF MID LEVEL
MOISTENING...ESPECIALLY OVER NORTHWESTERN PORTIONS OF THE CWA
OVERNIGHT. EVEN WITH THE MID LEVEL MOISTENING...THE BEST MOISTURE
IS NOT COLLOCATED WITH THE BEST DENDRITIC TEMPERATURES...SO ANY
SNOW WILL BE VERY LIGHT IN NATURE. ACROSS THE FAR SOUTHEASTERN
CWA...TEMPS WILL BE WARM TO SUPPORT DRIZZLE OR VERY LIGHT RAIN
EARLY THIS EVENING...FOLLOWED BY AREAS OF FREEZING DRIZZLE
OVERNIGHT. LOW LEVEL MOISTURE WILL BE MOST FAVORABLE FOR MORE
WIDESPREAD FREEZING DRIZZLE OVERNIGHT ACROSS FRONTIER AND FAR
SERN CUSTER COUNTY OVERNIGHT...AS IT FLOWS NORTH INTO NEBRASKA
FROM KANSAS. WITH THIS IN MIND...HAVE DECIDED TO PLACE FRONTIER
COUNTY IN A WINTER WEATHER ADVISORY AS QPF FORECASTS ARE
INDICATIVE OF UP TO A FEW HUNDREDTHS OF AN INCH OF FREEZING PCPN.
HOWEVER...ATTM...THE GREATEST THREAT FOR ACCUMULATING FREEZING
PCPN APPEARS TO BE WELL EAST OF THE FORECAST AREA MORE INTO
THURSDAY. WILL RUN THE ADVISORY FROM MIDNIGHT CST TONIGHT THROUGH
6 PM CST THURSDAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM CST WED NOV 25 2015
THE THANKSGIVING HOLIDAY TRAVEL EXPECTED TO BE IMPACTED ACROSS
MUCH OF THE AREA. A UPPER LEVEL LOW CUTS OFF ACROSS SW CONUS WITH
A POSITIVELY TILTED TROUGH ACROSS THE NORTHERN PLAINS. AT THE SFC
A COLD FRONT WILL BE EAST OF THE CWA WITH ARCTIC HIGH PRESSURE
BUILDING ACROSS THE ROCKIES. THE MAIN CONCERN FOR THE DAY ON
THURSDAY WILL BE THE LOWER LEVEL TEMP PROFILE AND THE POCKET OF
MID LEVEL DRY AIR. THE LATEST MODELS HAVE TRENDED SLIGHTLY
FURTHER EAST WITH THE COLD AIR AND BUFKIT SOUNDINGS NOW
SUGGESTING BY 12Z THE LOWER PROFILE ALL BELOW ZERO C AND HAVE
FORECAST NOW ALL SNOW. LIFT IS MARGINAL AND WILL BATTLE A POCKET
OF DRY AIR...SO EXPECT SNOW TO BE LIGHT AND WILL HAVE TO MONITOR
THE LEVEL OF DRYNESS AS PRECIP COULD SEE A MIX OF FREEZING
DRIZZLE HOWEVER NOT MENTIONED AT THIS TIME. THROUGH THE DAY
ACCUMULATION WILL BE LIGHT...LESS THAN AN INCH. AS FOR
TEMPS...THE COLD AIR ADVECTION AND PERSISTENT CLOUDS WILL LIMIT
WARMING. GUIDANCE SUGGEST TEMPS REBOUND A FEW DEGREES...HOWEVER
WOULD NOT BE SURPRISED IF TEMPS HELD STEADY OR EVEN FELL DURING
THE AFTERNOON. STILL WELL BELOW NORMAL WITH HIGHS IN THE MID TO
UPPER 20S.
COLD HIGH PRESSURE BUILDS ACROSS THE NORTHERN CWA THURSDAY NIGHT
INTO FRIDAY. THIS WILL USHER IN SOME DRY AIR AND CONFINE ANY SNOW
ACTIVITY TO THE SOUTHERN CWA...WHICH MAY NEED TO BE PUSHED
FURTHER SOUTH PENDING STRENGTH OF THE HIGH. LOWS ON THE COLD
SIDE...SINGLE DIGITS AND TEENS...REBOUNDING ONLY TO THE
20S...MAYBE 30 FOR FRIDAY.
OVER THE WEEKEND THE LOW WILL LIFT NORTH ACROSS THE ROCKIES AS
THE SFC HIGH SHIFTS EAST. RECYCLED COLD AIR WILL WRAP AROUND THE
HIGH AND OVER THE AREA. ALSO GOING TO SEE THE DRY AIR GET PUSHED
EAST WITH A LITTLE BETTER MOISTURE AND A RETURN TO AT LEAST A
SLIGHT CHANCE FOR LIGHT SNOW. THE LATEST EC BROUGHT A DISTURBANCE
AHEAD OF THE UPPER LEVEL LOW AND PRODUCED A BRIEF PERIOD OF
MODERATE SNOW SATURDAY NIGHT. WILL KEEP POPS LOW FOR NOW AND MAKE
A NOTE TO WATCH CAREFULLY.
EARLY NEXT WEEK THE UPPER LOW WILL SLIDE EAST ACROSS THE NORTHERN
PLAINS. COLD AIR REMAINS IN PLACE...HOWEVER COULD SEE SOME MORE
SUN AND HIGHS REBOUNDING INTO THE 30S. A CHANCE FOR SNOW MONDAY
REMAINS IN THE FORECAST...HOWEVER AS THE UPPER LEVEL LOW PUSHES
EAST THE CHANCE FOR ANY PRECIP DIMINISHES THROUGH MID WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1154 AM CST WED NOV 25 2015
DETERIORATING FLIGHT CONDITIONS ARE ANTICIPATED ACROSS ALL WEST
CENTRAL NEBRASKA TERMINALS THIS EVENING AND OVERNIGHT. THE MODEL
CONSENSUS GENERALLY CALLS FOR A PERIOD OF LIGHT FREEZING DRIZZLE
TO BE FOLLOWED BY LIGHT SNOW. ACCUMULATIONS ARE EXPECTED TO BE
LIGHT..BUT NORTHERLY WIND GUSTS TO 20KTS WILL HELP FURTHER REDUCE
VISIBILITY. FORECAST CONFIDENCE IN TIMING OF THE ONSET OF
PRECIPITATION IS LOWER THAN AVERAGE...BUT THERE/S HIGH CONFIDENCE
THAT THE PRECIPITATION WILL OCCUR.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST
THURSDAY FOR NEZ071.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...BUTTLER
LONG TERM...MASEK
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
550 AM CST WED NOV 25 2015
.SYNOPSIS...
ISSUED AT 340 AM CST WED NOV 25 2015
A CONVOLUTED H5 PATTERN CONTINUES TONIGHT ACROSS NOAM WITH A
RIDGE EXTENDING FROM THE NE PACIFIC INTO THE GULF OF ALASKA.
DOWNSTREAM OF THE RIDGE...A TROUGH EXTENDED FROM NRN SASKATCHEWAN
INTO NRN CALIFORNIA. AT THE BASE OF THIS TROUGH...CLOSED LOW
PRESSURE WAS NOTED OVER SWRN OREGON. EAST OF THE TROUGH...A ZONAL
PATTERN EXISTED ACROSS THE REMAINDER OF THE LOWER 48 STATES WITH
THE EXCEPTION OF A PERSISTENT TROUGH WHICH EXTENDED FROM EASTERN
QUEBEC...SWD INTO NEW ENGLAND. AT THE SURFACE...A FRONTAL
BOUNDARY WAS ANCHORED ALONG THE NEBR/SD BORDER AND MARKED THE
LEADING EDGE OF ARCTIC AIR WHICH WAS ENTRENCHED ACROSS THE NRN
PLAINS. READINGS OFF TO THE NORTH WERE IN THE TEENS IN MONTANA
WITH BREEZY NORTHERLY WINDS. SOUTH OF THE FRONT...TEMPERATURES
WERE IN THE 20S TO LOWER 30S WITH THE EXCEPTION SERN NEBRASKA
WHERE 40S AND LOWER 50S WERE COMMON THANKS TO LOW CLOUDS AND A
DECENT INFLUX OF LOW LEVEL MOISTURE PUSHING NORTH FROM EASTERN
KANSAS. FOR NOW...THE STRATUS AND LOW LEVEL MOISTURE HAS STAYED
JUST OFF TO THE EAST AND SOUTHEAST OF THE FORECAST AREA AND
SHOULD REMAIN THERE BASED ON THE LATEST HRRR FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST WED NOV 25 2015
FOR TODAY AND TONIGHT...THE MAIN FORECAST CHALLENGE WILL BE THE
THREAT FOR A WINTRY MIX OF PCPN BEGINNING TONIGHT. FOR
TODAY...THE ARCTIC COLD FRONT WILL PUSH SOUTH THIS MORNING AND
WILL CLEAR MOST OF THE FORECAST AREA BY MID AFTERNOON. HIGHS
TODAY WILL STRUGGLE TO GET OUT OF THE 30S IN THE
NORTHWEST...WHILE 40S ELSEWHERE REMAIN ON TRACK FOR THE FORECAST.
LIKE YESTERDAY...THERE WAS A LARGE DISPARITY IN HIGH TEMPERATURES
BETWEEN THE MAV AND MET GUIDANCE. THE MET SEEMED TOO COOL FOR
NORTH PLATTE TODAY WITH ITS HIGH OF 38 GIVEN THE LATER FRONTAL
TIMING OF EARLY AFTERNOON AND TRENDED THE TEMP FORECAST MORE
TOWARD THE WARMER MAV GUIDANCE. HOWEVER DID NOT GO WITH HIGHS AS
WARM AS THE MAV GUIDANCE SUGGESTS. THIS WAS DUE TO AN ABUNDANCE
OF MID AND HIGH LEVEL CLOUD COVER EXPECTED TODAY IN ADVANCE OF
THE APPG COLD FRONT.
TONIGHT...LOW LEVEL MOISTURE WILL INCREASE BEHIND THE EXITING
COLD FRONT AS A SHIELD OF STRATUS DEVELOPS ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA. ABOVE THE STRATUS...A DECENT DRY LAYER
WILL EXIST WITH SOME WEAK LIFT NOTED JUST ABOVE THE STRATUS LAYER
OVERNIGHT. A THOROUGH EXAMINATION OF BUFKIT FORECAST SOUNDINGS
INDICATES A DECENT SETUP FOR FREEZING DRIZZLE TONIGHT...ROUGHLY
EAST OF A LINE FROM SPRINGVIEW TO OGALLALA. WEST OF THIS
LINE...TEMPERATURE PROFILES IN THE MOIST LAYER SEEM TOO COLD FOR
THE DEVELOPMENT OF FREEZING DRIZZLE AND HAVE OPTED FOR A MENTION
OF SNOW AS THERE IS SOME INDICATION OF MID LEVEL
MOISTENING...ESPECIALLY OVER NORTHWESTERN PORTIONS OF THE CWA
OVERNIGHT. EVEN WITH THE MID LEVEL MOISTENING...THE BEST MOISTURE
IS NOT COLLOCATED WITH THE BEST DENDRITIC TEMPERATURES...SO ANY
SNOW WILL BE VERY LIGHT IN NATURE. ACROSS THE FAR SOUTHEASTERN
CWA...TEMPS WILL BE WARM TO SUPPORT DRIZZLE OR VERY LIGHT RAIN
EARLY THIS EVENING...FOLLOWED BY AREAS OF FREEZING DRIZZLE
OVERNIGHT. LOW LEVEL MOISTURE WILL BE MOST FAVORABLE FOR MORE
WIDESPREAD FREEZING DRIZZLE OVERNIGHT ACROSS FRONTIER AND FAR
SERN CUSTER COUNTY OVERNIGHT...AS IT FLOWS NORTH INTO NEBRASKA
FROM KANSAS. WITH THIS IN MIND...HAVE DECIDED TO PLACE FRONTIER
COUNTY IN A WINTER WEATHER ADVISORY AS QPF FORECASTS ARE
INDICATIVE OF UP TO A FEW HUNDREDTHS OF AN INCH OF FREEZING PCPN.
HOWEVER...ATTM...THE GREATEST THREAT FOR ACCUMULATING FREEZING
PCPN APPEARS TO BE WELL EAST OF THE FORECAST AREA MORE INTO
THURSDAY. WILL RUN THE ADVISORY FROM MIDNIGHT CST TONIGHT THROUGH
6 PM CST THURSDAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM CST WED NOV 25 2015
THE THANKSGIVING HOLIDAY TRAVEL EXPECTED TO BE IMPACTED ACROSS
MUCH OF THE AREA. A UPPER LEVEL LOW CUTS OFF ACROSS SW CONUS WITH
A POSITIVELY TILTED TROUGH ACROSS THE NORTHERN PLAINS. AT THE SFC
A COLD FRONT WILL BE EAST OF THE CWA WITH ARCTIC HIGH PRESSURE
BUILDING ACROSS THE ROCKIES. THE MAIN CONCERN FOR THE DAY ON
THURSDAY WILL BE THE LOWER LEVEL TEMP PROFILE AND THE POCKET OF
MID LEVEL DRY AIR. THE LATEST MODELS HAVE TRENDED SLIGHTLY
FURTHER EAST WITH THE COLD AIR AND BUFKIT SOUNDINGS NOW
SUGGESTING BY 12Z THE LOWER PROFILE ALL BELOW ZERO C AND HAVE
FORECAST NOW ALL SNOW. LIFT IS MARGINAL AND WILL BATTLE A POCKET
OF DRY AIR...SO EXPECT SNOW TO BE LIGHT AND WILL HAVE TO MONITOR
THE LEVEL OF DRYNESS AS PRECIP COULD SEE A MIX OF FREEZING
DRIZZLE HOWEVER NOT MENTIONED AT THIS TIME. THROUGH THE DAY
ACCUMULATION WILL BE LIGHT...LESS THAN AN INCH. AS FOR
TEMPS...THE COLD AIR ADVECTION AND PERSISTENT CLOUDS WILL LIMIT
WARMING. GUIDANCE SUGGEST TEMPS REBOUND A FEW DEGREES...HOWEVER
WOULD NOT BE SURPRISED IF TEMPS HELD STEADY OR EVEN FELL DURING
THE AFTERNOON. STILL WELL BELOW NORMAL WITH HIGHS IN THE MID TO
UPPER 20S.
COLD HIGH PRESSURE BUILDS ACROSS THE NORTHERN CWA THURSDAY NIGHT
INTO FRIDAY. THIS WILL USHER IN SOME DRY AIR AND CONFINE ANY SNOW
ACTIVITY TO THE SOUTHERN CWA...WHICH MAY NEED TO BE PUSHED
FURTHER SOUTH PENDING STRENGTH OF THE HIGH. LOWS ON THE COLD
SIDE...SINGLE DIGITS AND TEENS...REBOUNDING ONLY TO THE
20S...MAYBE 30 FOR FRIDAY.
OVER THE WEEKEND THE LOW WILL LIFT NORTH ACROSS THE ROCKIES AS
THE SFC HIGH SHIFTS EAST. RECYCLED COLD AIR WILL WRAP AROUND THE
HIGH AND OVER THE AREA. ALSO GOING TO SEE THE DRY AIR GET PUSHED
EAST WITH A LITTLE BETTER MOISTURE AND A RETURN TO AT LEAST A
SLIGHT CHANCE FOR LIGHT SNOW. THE LATEST EC BROUGHT A DISTURBANCE
AHEAD OF THE UPPER LEVEL LOW AND PRODUCED A BRIEF PERIOD OF
MODERATE SNOW SATURDAY NIGHT. WILL KEEP POPS LOW FOR NOW AND MAKE
A NOTE TO WATCH CAREFULLY.
EARLY NEXT WEEK THE UPPER LOW WILL SLIDE EAST ACROSS THE NORTHERN
PLAINS. COLD AIR REMAINS IN PLACE...HOWEVER COULD SEE SOME MORE
SUN AND HIGHS REBOUNDING INTO THE 30S. A CHANCE FOR SNOW MONDAY
REMAINS IN THE FORECAST...HOWEVER AS THE UPPER LEVEL LOW PUSHES
EAST THE CHANCE FOR ANY PRECIP DIMINISHES THROUGH MID WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 550 AM CST WED NOV 25 2015
FOR THE KLBF TERMINAL...FOG IS CURRENTLY MOVING NORTH FROM KANSAS
INTO SOUTHERN AND CENTRAL NEBRASKA. THIS WILL CONTINUE TO BE
MONITORED AS IT IS EXPECTED TO JUST PASS TO THE EAST OF THE KLBF
TERMINAL. FOR TODAY...EXPECT MOSTLY CLOUDY SKIES WITH CIGS
FALLING TO AROUND 5000 FT AGL BY 00Z THURSDAY. CIGS WILL FALL
FURTHER TO AROUND 1500 FT AGL OVERNIGHT WITH AN INCREASED THREAT
FOR FZDZ AFTER 05Z FRIDAY. FOR THE KVTN TERMINAL...LOOK FOR CIGS
TO FALL TO AROUND 5000 FT AGL BY MID MORNING TODAY...FALLING TO
1500 TO 2500 FT AGL THIS AFTERNOON. ATTM...THE MAIN THREAT FOR
FZDZ WILL BE SOUTH OF THE TERMINAL AND WILL NOT BE INCLUDED IN THE
12Z TAF ISSUANCE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM
MIDNIGHT TONIGHT TO 6 PM CST THURSDAY FOR NEZ071.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...BUTTLER
LONG TERM...MASEK
AVIATION...BUTTLER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
340 AM CST WED NOV 25 2015
.SYNOPSIS...
ISSUED AT 340 AM CST WED NOV 25 2015
A CONVOLUTED H5 PATTERN CONTINUES TONIGHT ACROSS NOAM WITH A
RIDGE EXTENDING FROM THE NE PACIFIC INTO THE GULF OF ALASKA.
DOWNSTREAM OF THE RIDGE...A TROUGH EXTENDED FROM NRN SASKATCHEWAN
INTO NRN CALIFORNIA. AT THE BASE OF THIS TROUGH...CLOSED LOW
PRESSURE WAS NOTED OVER SWRN OREGON. EAST OF THE TROUGH...A ZONAL
PATTERN EXISTED ACROSS THE REMAINDER OF THE LOWER 48 STATES WITH
THE EXCEPTION OF A PERSISTENT TROUGH WHICH EXTENDED FROM EASTERN
QUEBEC...SWD INTO NEW ENGLAND. AT THE SURFACE...A FRONTAL
BOUNDARY WAS ANCHORED ALONG THE NEBR/SD BORDER AND MARKED THE
LEADING EDGE OF ARCTIC AIR WHICH WAS ENTRENCHED ACROSS THE NRN
PLAINS. READINGS OFF TO THE NORTH WERE IN THE TEENS IN MONTANA
WITH BREEZY NORTHERLY WINDS. SOUTH OF THE FRONT...TEMPERATURES
WERE IN THE 20S TO LOWER 30S WITH THE EXCEPTION SERN NEBRASKA
WHERE 40S AND LOWER 50S WERE COMMON THANKS TO LOW CLOUDS AND A
DECENT INFLUX OF LOW LEVEL MOISTURE PUSHING NORTH FROM EASTERN
KANSAS. FOR NOW...THE STRATUS AND LOW LEVEL MOISTURE HAS STAYED
JUST OFF TO THE EAST AND SOUTHEAST OF THE FORECAST AREA AND
SHOULD REMAIN THERE BASED ON THE LATEST HRRR FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST WED NOV 25 2015
FOR TODAY AND TONIGHT...THE MAIN FORECAST CHALLENGE WILL BE THE
THREAT FOR A WINTRY MIX OF PCPN BEGINNING TONIGHT. FOR
TODAY...THE ARCTIC COLD FRONT WILL PUSH SOUTH THIS MORNING AND
WILL CLEAR MOST OF THE FORECAST AREA BY MID AFTERNOON. HIGHS
TODAY WILL STRUGGLE TO GET OUT OF THE 30S IN THE
NORTHWEST...WHILE 40S ELSEWHERE REMAIN ON TRACK FOR THE FORECAST.
LIKE YESTERDAY...THERE WAS A LARGE DISPARITY IN HIGH TEMPERATURES
BETWEEN THE MAV AND MET GUIDANCE. THE MET SEEMED TOO COOL FOR
NORTH PLATTE TODAY WITH ITS HIGH OF 38 GIVEN THE LATER FRONTAL
TIMING OF EARLY AFTERNOON AND TRENDED THE TEMP FORECAST MORE
TOWARD THE WARMER MAV GUIDANCE. HOWEVER DID NOT GO WITH HIGHS AS
WARM AS THE MAV GUIDANCE SUGGESTS. THIS WAS DUE TO AN ABUNDANCE
OF MID AND HIGH LEVEL CLOUD COVER EXPECTED TODAY IN ADVANCE OF
THE APPG COLD FRONT.
TONIGHT...LOW LEVEL MOISTURE WILL INCREASE BEHIND THE EXITING
COLD FRONT AS A SHIELD OF STRATUS DEVELOPS ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA. ABOVE THE STRATUS...A DECENT DRY LAYER
WILL EXIST WITH SOME WEAK LIFT NOTED JUST ABOVE THE STRATUS LAYER
OVERNIGHT. A THOROUGH EXAMINATION OF BUFKIT FORECAST SOUNDINGS
INDICATES A DECENT SETUP FOR FREEZING DRIZZLE TONIGHT...ROUGHLY
EAST OF A LINE FROM SPRINGVIEW TO OGALLALA. WEST OF THIS
LINE...TEMPERATURE PROFILES IN THE MOIST LAYER SEEM TOO COLD FOR
THE DEVELOPMENT OF FREEZING DRIZZLE AND HAVE OPTED FOR A MENTION
OF SNOW AS THERE IS SOME INDICATION OF MID LEVEL
MOISTENING...ESPECIALLY OVER NORTHWESTERN PORTIONS OF THE CWA
OVERNIGHT. EVEN WITH THE MID LEVEL MOISTENING...THE BEST MOISTURE
IS NOT COLLOCATED WITH THE BEST DENDRITIC TEMPERATURES...SO ANY
SNOW WILL BE VERY LIGHT IN NATURE. ACROSS THE FAR SOUTHEASTERN
CWA...TEMPS WILL BE WARM TO SUPPORT DRIZZLE OR VERY LIGHT RAIN
EARLY THIS EVENING...FOLLOWED BY AREAS OF FREEZING DRIZZLE
OVERNIGHT. LOW LEVEL MOISTURE WILL BE MOST FAVORABLE FOR MORE
WIDESPREAD FREEZING DRIZZLE OVERNIGHT ACROSS FRONTIER AND FAR
SERN CUSTER COUNTY OVERNIGHT...AS IT FLOWS NORTH INTO NEBRASKA
FROM KANSAS. WITH THIS IN MIND...HAVE DECIDED TO PLACE FRONTIER
COUNTY IN A WINTER WEATHER ADVISORY AS QPF FORECASTS ARE
INDICATIVE OF UP TO A FEW HUNDREDTHS OF AN INCH OF FREEZING PCPN.
HOWEVER...ATTM...THE GREATEST THREAT FOR ACCUMULATING FREEZING
PCPN APPEARS TO BE WELL EAST OF THE FORECAST AREA MORE INTO
THURSDAY. WILL RUN THE ADVISORY FROM MIDNIGHT CST TONIGHT THROUGH
6 PM CST THURSDAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM CST WED NOV 25 2015
THE THANKSGIVING HOLIDAY TRAVEL EXPECTED TO BE IMPACTED ACROSS
MUCH OF THE AREA. A UPPER LEVEL LOW CUTS OFF ACROSS SW CONUS WITH
A POSITIVELY TILTED TROUGH ACROSS THE NORTHERN PLAINS. AT THE SFC
A COLD FRONT WILL BE EAST OF THE CWA WITH ARCTIC HIGH PRESSURE
BUILDING ACROSS THE ROCKIES. THE MAIN CONCERN FOR THE DAY ON
THURSDAY WILL BE THE LOWER LEVEL TEMP PROFILE AND THE POCKET OF
MID LEVEL DRY AIR. THE LATEST MODELS HAVE TRENDED SLIGHTLY
FURTHER EAST WITH THE COLD AIR AND BUFKIT SOUNDINGS NOW
SUGGESTING BY 12Z THE LOWER PROFILE ALL BELOW ZERO C AND HAVE
FORECAST NOW ALL SNOW. LIFT IS MARGINAL AND WILL BATTLE A POCKET
OF DRY AIR...SO EXPECT SNOW TO BE LIGHT AND WILL HAVE TO MONITOR
THE LEVEL OF DRYNESS AS PRECIP COULD SEE A MIX OF FREEZING
DRIZZLE HOWEVER NOT MENTIONED AT THIS TIME. THROUGH THE DAY
ACCUMULATION WILL BE LIGHT...LESS THAN AN INCH. AS FOR
TEMPS...THE COLD AIR ADVECTION AND PERSISTENT CLOUDS WILL LIMIT
WARMING. GUIDANCE SUGGEST TEMPS REBOUND A FEW DEGREES...HOWEVER
WOULD NOT BE SURPRISED IF TEMPS HELD STEADY OR EVEN FELL DURING
THE AFTERNOON. STILL WELL BELOW NORMAL WITH HIGHS IN THE MID TO
UPPER 20S.
COLD HIGH PRESSURE BUILDS ACROSS THE NORTHERN CWA THURSDAY NIGHT
INTO FRIDAY. THIS WILL USHER IN SOME DRY AIR AND CONFINE ANY SNOW
ACTIVITY TO THE SOUTHERN CWA...WHICH MAY NEED TO BE PUSHED
FURTHER SOUTH PENDING STRENGTH OF THE HIGH. LOWS ON THE COLD
SIDE...SINGLE DIGITS AND TEENS...REBOUNDING ONLY TO THE
20S...MAYBE 30 FOR FRIDAY.
OVER THE WEEKEND THE LOW WILL LIFT NORTH ACROSS THE ROCKIES AS
THE SFC HIGH SHIFTS EAST. RECYCLED COLD AIR WILL WRAP AROUND THE
HIGH AND OVER THE AREA. ALSO GOING TO SEE THE DRY AIR GET PUSHED
EAST WITH A LITTLE BETTER MOISTURE AND A RETURN TO AT LEAST A
SLIGHT CHANCE FOR LIGHT SNOW. THE LATEST EC BROUGHT A DISTURBANCE
AHEAD OF THE UPPER LEVEL LOW AND PRODUCED A BRIEF PERIOD OF
MODERATE SNOW SATURDAY NIGHT. WILL KEEP POPS LOW FOR NOW AND MAKE
A NOTE TO WATCH CAREFULLY.
EARLY NEXT WEEK THE UPPER LOW WILL SLIDE EAST ACROSS THE NORTHERN
PLAINS. COLD AIR REMAINS IN PLACE...HOWEVER COULD SEE SOME MORE
SUN AND HIGHS REBOUNDING INTO THE 30S. A CHANCE FOR SNOW MONDAY
REMAINS IN THE FORECAST...HOWEVER AS THE UPPER LEVEL LOW PUSHES
EAST THE CHANCE FOR ANY PRECIP DIMINISHES THROUGH MID WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1140 PM CST TUE NOV 24 2015
STRATUS WILL STAY TO THE EAST OF WESTERN NEBRASKA OVER NIGHT.
SOME OF THE STRATUS WILL FIND ITS WAY INTO CENTRAL NEBRASKA
THROUGH THE EARLY MORNING HOURS. COLD FRONT WILL CONTINUE TO MOVE
SOUTH OUT OF SOUTH DAKOTA INTO NORTHWEST NEBRASKA THROUGH THE
EARLY MORNING HOURS. WITH THE FRONT WEDNESDAY MORNING NORTHWEST
WINDS WILL INCREASE AND BECOME GUSTY. AREAS OF DRIZZLE WILL BE
POSSIBLE OVER NORTHWEST NEBRASKA THROUGH THE AFTERNOON AND COULD
AFFECT BOTH KVTN AND KLBF TAF SITES THROUGH THE EARLY EVENING.
CEILINGS WILL LOWER INTO MVFR CATEGORIES CIGS THROUGH THE
AFTERNOON AND THERE COULD BE SOME FREEZING DRIZZLE OVER NORTHERN
NEBRASKA AROUND 26/00Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST
THURSDAY FOR NEZ071.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...BUTTLER
LONG TERM...MASEK
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1050 AM PST WED NOV 25 2015
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTH ACROSS THE REGION
TODAY BRINGING MUCH COLDER TEMPERATURES TO THE REGION ALONG WITH A
FEW SHOWERS TO THE SOUTHERN GREAT BASIN. COLDER AIR WILL STICK
AROUND THROUGH THE HOLIDAY WEEKEND. OCCASIONAL PERIODS OF SHOWERS
ARE EXPECTED IN THE HIGHER TERRAIN OF THE SOUTHERN GREAT BASIN AND
THE SIERRA THROUGH SUNDAY. THERE IS SOME POTENTIAL FOR SHOWERS
ACROSS OTHER PARTS OF THE AREA ON SUNDAY.
&&
.UPDATE...I DID A QUICK UPDATE TO THE GRIDS TO LOWER SNOW LEVELS AND
BRING A RAIN/SNOW MIX IN PARTS OF CLARK AND SOUTHERN NYE COUNTIES AS
THE BAND OF SHOWERS HAS RESULTED IN A LITTLE SNOW MIXING IN WITH
RAIN IN INDIAN SPRINGS AND PAHRUMP. WE MAY ALSO SEE SOMETHING
SIMILAR IN THE EASTERN FOOTHILLS OF THE SPRING MOUNTAINS AND FAR
WEST SIDE OF THE LAS VEGAS VALLEY DEPENDING ON HOW INTENSE THE BAND
IS AT IT MOVES ON IN THE NEXT HOUR OR TWO.
&&
.PREVIOUS UPDATE...
ISSUED AT 953 AM PST WED NOV 25 2015
.UPDATE...A COLD FRONT EXTENDED FROM LINCOLN COUNTY TOWARD THE
CLARK/SOUTHERN NYE BORDER AND SOUTHWEST TOWARD MALIBU, CALIFORNIA.
THE FRONT JUST PASSED THROUGH DESERT ROCK SHIFTING WINDS TO THE
NORTHEAST. KESX RADAR IS FINALLY GETTING LOWER TOPPED PRECIPITATION
INTO RADAR BEAM RANGE AND THUS WE ARE SEEING SOME LIGHT RETURNS.
DESERT ROCK ASOS DID REPORT A TRACE OF RAIN AS THIS BAND PASSED
THROUGH. THE RADAR IS OVERSHOOTING SHOWERS ACROSS LINCOLN COUNTY AS
ELY HAS HAD SIMILAR CLOUDTOPS ON INFRARED SATELLITE AND REPORTED
MODERATE SNOW. SO WE SHOULD SEE SOME LIGHT ACCUMULATIONS ESPECIALLY
NORTH OF PIOCHE AS THIS BAND OF SHOWERS MOVES ON THROUGH. I ADJUSTED
THE POP GRIDS TO ACCOUNT FOR THE LATEST TRENDS ON SATELLITE AND
RADAR.
THE HRRR SEEMS TO REALLY SLOW THE WIND SHIFT DOWN WITH THE FRONT IN
THE LAS VEGAS VALLEY. THIS MAY BE A FRONT THAT GETS A WIND SHIFT
MUCH QUICKER IN AREAS NORTH OF SAHARA AVENUE AND SOUTH OF THAT SEES
A DELAY FOR WINDS TO GO NORTHWEST. EITHER WAY OBS UPSTREAM SHOW
WINDS TANKING IN STRENGTH BEHIND THE FRONT AND WINDS WILL DECREASE
IN THE LAS VEGAS VALLEY BY THIS AFTERNOON.
THE REST OF THE FORECAST LOOKS FINE AT THIS TIME.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 451 AM PST WED NOV 25 2015
.SHORT TERM...THROUGH FRIDAY NIGHT.
WINDS SHOULD BEGIN TO DECREASE AS A COLD FRONT PUSHES SOUTH ACROSS
THE REGION TODAY. THE MAIN HIGHLIGHT WITH THIS FEATURE WILL BE THE
SIGNIFICANTLY COLDER AIR (15-20 DEGREES COOLER THAN YESTERDAY) THAT
WILL SPREAD ACROSS THE REGION...REMAINING IN PLACE INTO THE HOLIDAY
WEEKEND WITH THE UPPER LEVEL LOW MEANDERING OVER THE GREAT BASIN.
RAIN AND MOUNTAIN SNOW SHOWERS MAY ALSO ACCOMPANY THE FRONT...BUT
AMOUNTS ARE EXPECTED TO REMAIN LIGHT. THE BEST CHANCES FOR SHOWERS
WILL BE ACROSS LINCOLN COUNTY TODAY. THE FOCUS THEN TURNS TO
OVERNIGHT TEMPERATURES WHICH WILL LIKELY FALL INTO THE 30`S IN THE
LAS VEGAS VALLEY AND NORTHEAST CLARK COUNTY THE NEXT COUPLE OF
NIGHTS. A FREEZE WATCH REMAINS IN PLACE FOR THESE AREAS SINCE
CONFIDENCE IN TEMPERATURES REACHING THE FREEZING MARK IS LOW AT THIS
TIME.
.LONG TERM...SATURDAY THROUGH WEDNESDAY.
BY SATURDAY MORNING...A REX BLOCK WILL BE FIRMLY IN PLACE ACROSS THE
REGION WITH A MID-LARGE UPPER LEVEL LOW PARKED OVER THE SOUTHERN
GREAT BASIN. THIS WILL KEEP CLOUDY AND COOL CONDITIONS AROUND
THROUGH MUCH OF THE WEEKEND...WITH AFTERNOON HIGHS GENERALLY RUNNING
8-12 DEGREES BELOW AVERAGE FOR LATE NOVEMBER. HOWEVER...AS DISCUSSED
IN YESTERDAY AFTERNOON`S AFD...THE FORECAST CONCERN FOR THIS PERIOD
CONTINUES TO BE WHETHER THERE WILL BE ENOUGH MOISTURE PRESENT FOR
PRECIPITATION OR NOT. OPERATIONAL MODEL GUIDANCE AND THEIR
ASSOCIATED ENSEMBLES GENERALLY AGREE IN A SECONDARY SHORTWAVE
GETTING PULLED INTO THE MAIN UPPER LOW SATURDAY AFTERNOON - SUNDAY
MORNING TIMEFRAME. SOME TIMING DIFFERENCES DO EXIST BETWEEN THE 00Z
GFS AND ECMWF SOLUTIONS...WITH THE GFS RUNNING ABOUT 12-18 HOURS
QUICKER IN BRINGING THE SECONDARY SHORTWAVE ACROSS THE REGION. LIKE
THE 12Z RUN...THE LATEST RUN OF THE GFS CONTINUES TO AGGRESSIVELY
EMPHASIZE THE AMOUNT MOISTURE ASSOCIATED WITH THIS FEATURE AS IT
ROTATES AROUND THE BASE OF THE LOW. AS A RESULT...DECIDED TO FAVOR
THE LESS AGGRESSIVE ECMWF SOLUTION...WHICH DOES INDICATE SUFFICIENT
MID-LEVEL MOISTURE WITH THIS FEATURE. THEREFORE...CONTINUED TO
MENTION SLIGHT CHANCE POPS FOR THE SATURDAY AFTERNOON-SUNDAY MORNING
TIMEFRAME...MAINLY ACROSS THE SOUTHERN GREAT BASIN ZONES. IT WILL BE
INTERESTING TO SEE HOW FUTURE MODEL RUNS EVOLVE WITH RESPECT TO
TIMING THIS SHORTWAVE AND HOW MUCH MOISTURE WILL BE ASSOCIATED WITH
IT.
THERE IS FAIRLY CONSISTENT AGREEMENT IN ANOTHER PIECE OF ENERGY
BREAKING OFF FROM THE GULF OF ALASKA LOW AND DEVELOPING A KICKER LOW
OVER THE EASTERN PACIFIC THAT WILL HELP TO BREAK THE REX BLOCK
PATTERN OVER THE REGION. UNFORTUNATELY...THAT IS THE EXTENT OF MODEL
CONSENSUS FOR THE TIME BEING...AS EACH OPERATIONAL MODEL HANDLES THE
EVOLUTION OF THIS FEATURE DIFFERENTLY...RESULTING IN A LOW
CONFIDENCE FORECAST. AS A RESULT...CONTINUED MOSTLY WITH WHAT WAS
INHERITED IN THE GRIDS FOR MONDAY THROUGH WEDNESDAY MORNING...WITH
THE CHANCES OF CONTINUED BELOW AVERAGE TEMPERATURES LOOKING HIGH FOR
MUCH OF THE AREA.
&&
.AVIATION...FOR MCCARRAN...SOUTHWEST WINDS WITH GUSTS OF 20-30 KTS
AND AREAS OF MECHANICAL TURBULENCE WILL CONTINUE THROUGH THE REST OF
THE MORNING BEFORE A COLD FRONT MOVES INTO THE LAS VEGAS VALLEY
BETWEEN 19-21Z. THIS FRONT WILL TURN THE WINDS TO THE NORTHWEST...AT
LEAST BRIEFLY. WINDS MAY RETURN TO A MORE WEST TO SOUTHWEST
DIRECTION LATER IN THE AFTERNOON OR EARLY EVENING AS THE IMPACT FROM
THE COLD FRONT DIMINISHES. FEW-SCT CLOUDS AOA 8K FEET ARE EXPECTED
THROUGH THE PERIOD. LIGHTER WINDS ARE EXPECTED THROUGH THURSDAY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...GUSTY SOUTHWEST WINDS WILL GIVE WAY TO NORTHWESTERLY
WINDS AS A COLD FRONT PUSHES THROUGH THE REGION TODAY. THE FRONT
WILL DIMINISH IN STRENGTH AS IT MOVES THROUGH THE LAS VEGAS VALLEY.
EXPECT SOME WEAK SHOWER ACTIVITY NEAR THE FRONT AS IT MOVES THROUGH
THE SOUTHERN GREAT BASIN. LIGHTER WINDS ARE EXPECTED ACROSS THE
REGION THURSDAY. SCT-BKN CLOUDS MAINLY AOA 6-8K FEET THROUGH THE
PERIOD...ALONG WITH MECHANICAL TURBULENCE NEAR THE HIGH TERRAIN.
&&
$$
UPDATE...STACHELSKI
SHORT TERM/AVIATION...WOLCOTT
LONG TERM...PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
953 AM PST WED NOV 25 2015
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTH ACROSS THE REGION
TODAY BRINGING MUCH COLDER TEMPERATURES TO THE REGION ALONG WITH A
FEW SHOWERS TO THE SOUTHERN GREAT BASIN. COLDER AIR WILL STICK
AROUND THROUGH THE HOLIDAY WEEKEND. OCCASIONAL PERIODS OF SHOWERS
ARE EXPECTED IN THE HIGHER TERRAIN OF THE SOUTHERN GREAT BASIN AND
THE SIERRA THROUGH SUNDAY. THERE IS SOME POTENTIAL FOR SHOWERS
ACROSS OTHER PARTS OF THE AREA ON SUNDAY.
&&
.UPDATE...A COLD FRONT EXTENDED FROM LINCOLN COUNTY TOWARD THE
CLARK/SOUTHERN NYE BORDER AND SOUTHWEST TOWARD MALIBU, CALIFORNIA.
THE FRONT JUST PASSED THROUGH DESERT ROCK SHIFTING WINDS TO THE
NORTHEAST. KESX RADAR IS FINALLY GETTING LOWER TOPPED PRECIPITATION
INTO RADAR BEAM RANGE AND THUS WE ARE SEEING SOME LIGHT RETURNS.
DESERT ROCK ASOS DID REPORT A TRACE OF RAIN AS THIS BAND PASSED
THROUGH. THE RADAR IS OVERSHOOTING SHOWERS ACROSS LINCOLN COUNTY AS
ELY HAS HAD SIMILAR CLOUDTOPS ON INFRARED SATELLITE AND REPORTED
MODERATE SNOW. SO WE SHOULD SEE SOME LIGHT ACCUMULATIONS ESPECIALLY
NORTH OF PIOCHE AS THIS BAND OF SHOWERS MOVES ON THROUGH. I ADJUSTED
THE POP GRIDS TO ACCOUNT FOR THE LATEST TRENDS ON SATELLITE AND
RADAR.
THE HRRR SEEMS TO REALLY SLOW THE WIND SHIFT DOWN WITH THE FRONT IN
THE LAS VEGAS VALLEY. THIS MAY BE A FRONT THAT GETS A WIND SHIFT
MUCH QUICKER IN AREAS NORTH OF SAHARA AVENUE AND SOUTH OF THAT SEES
A DELAY FOR WINDS TO GO NORTHWEST. EITHER WAY OBS UPSTREAM SHOW
WINDS TANKING IN STRENGTH BEHIND THE FRONT AND WINDS WILL DECREASE
IN THE LAS VEGAS VALLEY BY THIS AFTERNOON.
THE REST OF THE FORECAST LOOKS FINE AT THIS TIME.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 451 AM PST WED NOV 25 2015
.SHORT TERM...THROUGH FRIDAY NIGHT.
WINDS SHOULD BEGIN TO DECREASE AS A COLD FRONT PUSHES SOUTH ACROSS
THE REGION TODAY. THE MAIN HIGHLIGHT WITH THIS FEATURE WILL BE THE
SIGNIFICANTLY COLDER AIR (15-20 DEGREES COOLER THAN YESTERDAY) THAT
WILL SPREAD ACROSS THE REGION...REMAINING IN PLACE INTO THE HOLIDAY
WEEKEND WITH THE UPPER LEVEL LOW MEANDERING OVER THE GREAT BASIN.
RAIN AND MOUNTAIN SNOW SHOWERS MAY ALSO ACCOMPANY THE FRONT...BUT
AMOUNTS ARE EXPECTED TO REMAIN LIGHT. THE BEST CHANCES FOR SHOWERS
WILL BE ACROSS LINCOLN COUNTY TODAY. THE FOCUS THEN TURNS TO
OVERNIGHT TEMPERATURES WHICH WILL LIKELY FALL INTO THE 30`S IN THE
LAS VEGAS VALLEY AND NORTHEAST CLARK COUNTY THE NEXT COUPLE OF
NIGHTS. A FREEZE WATCH REMAINS IN PLACE FOR THESE AREAS SINCE
CONFIDENCE IN TEMPERATURES REACHING THE FREEZING MARK IS LOW AT THIS
TIME.
.LONG TERM...SATURDAY THROUGH WEDNESDAY.
BY SATURDAY MORNING...A REX BLOCK WILL BE FIRMLY IN PLACE ACROSS THE
REGION WITH A MID-LARGE UPPER LEVEL LOW PARKED OVER THE SOUTHERN
GREAT BASIN. THIS WILL KEEP CLOUDY AND COOL CONDITIONS AROUND
THROUGH MUCH OF THE WEEKEND...WITH AFTERNOON HIGHS GENERALLY RUNNING
8-12 DEGREES BELOW AVERAGE FOR LATE NOVEMBER. HOWEVER...AS DISCUSSED
IN YESTERDAY AFTERNOON`S AFD...THE FORECAST CONCERN FOR THIS PERIOD
CONTINUES TO BE WHETHER THERE WILL BE ENOUGH MOISTURE PRESENT FOR
PRECIPITATION OR NOT. OPERATIONAL MODEL GUIDANCE AND THEIR
ASSOCIATED ENSEMBLES GENERALLY AGREE IN A SECONDARY SHORTWAVE
GETTING PULLED INTO THE MAIN UPPER LOW SATURDAY AFTERNOON - SUNDAY
MORNING TIMEFRAME. SOME TIMING DIFFERENCES DO EXIST BETWEEN THE 00Z
GFS AND ECMWF SOLUTIONS...WITH THE GFS RUNNING ABOUT 12-18 HOURS
QUICKER IN BRINGING THE SECONDARY SHORTWAVE ACROSS THE REGION. LIKE
THE 12Z RUN...THE LATEST RUN OF THE GFS CONTINUES TO AGGRESSIVELY
EMPHASIZE THE AMOUNT MOISTURE ASSOCIATED WITH THIS FEATURE AS IT
ROTATES AROUND THE BASE OF THE LOW. AS A RESULT...DECIDED TO FAVOR
THE LESS AGGRESSIVE ECMWF SOLUTION...WHICH DOES INDICATE SUFFICIENT
MID-LEVEL MOISTURE WITH THIS FEATURE. THEREFORE...CONTINUED TO
MENTION SLIGHT CHANCE POPS FOR THE SATURDAY AFTERNOON-SUNDAY MORNING
TIMEFRAME...MAINLY ACROSS THE SOUTHERN GREAT BASIN ZONES. IT WILL BE
INTERESTING TO SEE HOW FUTURE MODEL RUNS EVOLVE WITH RESPECT TO
TIMING THIS SHORTWAVE AND HOW MUCH MOISTURE WILL BE ASSOCIATED WITH
IT.
THERE IS FAIRLY CONSISTENT AGREEMENT IN ANOTHER PIECE OF ENERGY
BREAKING OFF FROM THE GULF OF ALASKA LOW AND DEVELOPING A KICKER LOW
OVER THE EASTERN PACIFIC THAT WILL HELP TO BREAK THE REX BLOCK
PATTERN OVER THE REGION. UNFORTUNATELY...THAT IS THE EXTENT OF MODEL
CONSENSUS FOR THE TIME BEING...AS EACH OPERATIONAL MODEL HANDLES THE
EVOLUTION OF THIS FEATURE DIFFERENTLY...RESULTING IN A LOW
CONFIDENCE FORECAST. AS A RESULT...CONTINUED MOSTLY WITH WHAT WAS
INHERITED IN THE GRIDS FOR MONDAY THROUGH WEDNESDAY MORNING...WITH
THE CHANCES OF CONTINUED BELOW AVERAGE TEMPERATURES LOOKING HIGH FOR
MUCH OF THE AREA.
&&
.AVIATION...FOR MCCARRAN...SOUTHWEST WINDS WITH GUSTS OF 20-30 KTS
AND AREAS OF MECHANICAL TURBULENCE WILL CONTINUE THROUGH THE REST OF
THE MORNING BEFORE A COLD FRONT MOVES INTO THE LAS VEGAS VALLEY
BETWEEN 19-21Z. THIS FRONT WILL TURN THE WINDS TO THE NORTHWEST...AT
LEAST BRIEFLY. WINDS MAY RETURN TO A MORE WEST TO SOUTHWEST
DIRECTION LATER IN THE AFTERNOON OR EARLY EVENING AS THE IMPACT FROM
THE COLD FRONT DIMINISHES. FEW-SCT CLOUDS AOA 8K FEET ARE EXPECTED
THROUGH THE PERIOD. LIGHTER WINDS ARE EXPECTED THROUGH THURSDAY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...GUSTY SOUTHWEST WINDS WILL GIVE WAY TO NORTHWESTERLY
WINDS AS A COLD FRONT PUSHES THROUGH THE REGION TODAY. THE FRONT
WILL DIMINISH IN STRENGTH AS IT MOVES THROUGH THE LAS VEGAS VALLEY.
EXPECT SOME WEAK SHOWER ACTIVITY NEAR THE FRONT AS IT MOVES THROUGH
THE SOUTHERN GREAT BASIN. LIGHTER WINDS ARE EXPECTED ACROSS THE
REGION THURSDAY. SCT-BKN CLOUDS MAINLY AOA 6-8K FEET THROUGH THE
PERIOD...ALONG WITH MECHANICAL TURBULENCE NEAR THE HIGH TERRAIN.
&&
$$
UPDATE...STACHELSKI
SHORT TERM/AVIATION...WOLCOTT
LONG TERM...PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
933 AM PST WED NOV 25 2015
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTH ACROSS THE REGION
TODAY BRINGING MUCH COLDER TEMPERATURES TO THE REGION ALONG WITH A
FEW SHOWERS TO THE SOUTHERN GREAT BASIN. COLDER AIR WILL STICK
AROUND THROUGH THE HOLIDAY WEEKEND. OCCASIONAL PERIODS OF SHOWERS
ARE EXPECTED IN THE HIGHER TERRAIN OF THE SOUTHERN GREAT BASIN AND
THE SIERRA THROUGH SUNDAY. THERE IS SOME POTENTIAL FOR SHOWERS
ACROSS OTHER PARTS OF THE AREA ON SUNDAY.
&&
.UPDATE...A COLD FRONT EXTENDED FROM LINCOLN COUNTY TOWARD THE
CLARK/SOUTHERN NYE BORDER AND SOUTHWEST TOWARD MALIBU, CALIFORNIA.
THE FRONT JUST PASSED THROUGH DESERT ROCK SHIFTING WINDS TO THE
NORTHEAST. KESX RADAR IS FINALLY GETTING LOWER TOPPED PRECIPITATION
INTO RADAR BEAM RANGE AND THUS WE ARE SEEING SOME LIGHT RETURNS.
DESERT ROCK ASOS DID REPORT A TRACE OF RAIN AS THIS BAND PASSED
THROUGH. THE RADAR IS OVERSHOOTING SHOWERS ACROSS LINCOLN COUNTY AS
ELY HAS HAD SIMILAR CLOUDTOPS ON INFRARED SATELLITE AND REPORTED
MODERATE SNOW. SO WE SHOULD SEE SOME LIGHT ACCUMULATIONS ESPECIALLY
NORTH OF PIOCHE AS THIS BAND OF SHOWERS MOVES ON THROUGH. I ADJUSTED
THE POP GRIDS TO ACCOUNT FOR THE LATEST TRENDS ON SATELLITE AND
RADAR.
THE HRRR SEEMS TO REALLY SLOW THE WIND SHIFT DOWN WITH THE FRONT IN
THE LAS VEGAS VALLEY. THIS MAY BE A FRONT THAT GETS A WIND SHIFT
MUCH QUICKER IN AREAS NORTH OF SAHARA AVENUE AND SOUTH OF THAT SEES
A DELAY FOR WINDS TO GO NORTHWEST. EITHER WAY OBS UPSTREAM SHOW
WINDS TANKING IN STRENGTH BEHIND THE FRONT AND WINDS WILL DECREASE
IN THE LAS VEGAS VALLEY BY THIS AFTERNOON.
THE REST OF THE FORECAST LOOKS FINE AT THIS TIME.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 451 AM PST WED NOV 25 2015
.SHORT TERM...THROUGH FRIDAY NIGHT.
WINDS SHOULD BEGIN TO DECREASE AS A COLD FRONT PUSHES SOUTH ACROSS
THE REGION TODAY. THE MAIN HIGHLIGHT WITH THIS FEATURE WILL BE THE
SIGNIFICANTLY COLDER AIR (15-20 DEGREES COOLER THAN YESTERDAY) THAT
WILL SPREAD ACROSS THE REGION...REMAINING IN PLACE INTO THE HOLIDAY
WEEKEND WITH THE UPPER LEVEL LOW MEANDERING OVER THE GREAT BASIN.
RAIN AND MOUNTAIN SNOW SHOWERS MAY ALSO ACCOMPANY THE FRONT...BUT
AMOUNTS ARE EXPECTED TO REMAIN LIGHT. THE BEST CHANCES FOR SHOWERS
WILL BE ACROSS LINCOLN COUNTY TODAY. FOCUS THEN TURNS TO OVERNIGHT
TEMPERATURES WHICH WILL LIKELY FALL INTO THE 30`S IN THE LAS VEGAS
VALLEY AND NORTHEAST CLARK COUNTY THE NEXT COUPLE NIGHT. A FREEZE
WATCH REMAINS IN PLACE FOR THESES AREAS SINCE CONFIDENCE IN
TEMPERATURES REACHING THE FREEZING MARK IS LOW AT THIS TIME.
.LONG TERM...SATURDAY THROUGH WEDNESDAY.
BY SATURDAY MORNING...A REX BLOCK WILL BE FIRMLY IN PLACE ACROSS THE
REGION WITH A MID-LARGE UPPER LEVEL LOW PARKED OVER THE SOUTHERN
GREAT BASIN. THIS WILL KEEP CLOUDY AND COOL CONDITIONS AROUND
THROUGH MUCH OF THE WEEKEND...WITH AFTERNOON HIGHS GENERALLY RUNNING
8-12 DEGREES BELOW AVERAGE FOR LATE NOVEMBER. HOWEVER...AS DISCUSSED
IN YESTERDAY AFTERNOONS AFD...THE FORECAST CONCERN FOR THIS PERIOD
CONTINUES TO BE WHETHER THERE WILL BE ENOUGH MOISTURE PRESENT FOR
PRECIPITATION OR NOT. OPERATIONAL MODEL GUIDANCE AND THEIR
ASSOCIATED ENSEMBLES GENERALLY AGREE IN A SECONDARY SHORTWAVE
GETTING PULLED INTO THE MAIN UPPER LOW SATURDAY AFTERNOON - SUNDAY
MORNING TIMEFRAME. SOME TIMING DIFFERENCES DO EXIST BETWEEN THE 00Z
GFS AND ECMWF SOLUTIONS...WITH THE GFS RUNNING ABOUT 12-18 HOURS
QUICKER IN BRINGING THE SECONDARY SHORTWAVE ACROSS THE REGION. LIKE
THE 12Z RUN...THE LATEST RUN OF THE GFS CONTINUES TO AGGRESSIVELY
EMPHASIZE THE AMOUNT MOISTURE ASSOCIATED WITH THIS FEATURE AS IT
ROTATES AROUND THE BASE OF THE LOW. AS A RESULT...DECIDED TO FAVOR
THE LESS AGGRESSIVE ECMWF SOLUTION...WHICH DOES INDICATE SUFFICIENT
MID-LEVEL MOISTURE WITH THIS FEATURE. THEREFORE...CONTINUED TO
MENTION SLIGHT CHANCE POPS FOR THE SATURDAY AFTERNOON-SUNDAY MORNING
TIMEFRAME...MAINLY ACROSS THE SOUTHERN GREAT BASIN ZONES. IT WILL BE
INTERESTING TO SEE HOW FUTURE MODEL RUNS EVOLVE WITH RESPECT TO
TIMING THIS SHORTWAVE AND HOW MUCH MOISTURE WILL BE ASSOCIATED WITH
IT.
THERE IS FAIRLY CONSISTENT AGREEMENT IN ANOTHER PIECE OF ENERGY
BREAKING OFF FROM THE GULF OF ALASKA LOW AND DEVELOPING A KICKER LOW
OVER THE EASTERN PACIFIC THAT WILL HELP TO BREAK THE REX BLOCK
PATTERN OVER THE REGION. UNFORTUNATELY...THAT IS THE EXTENT OF MODEL
CONSENSUS FOR THE TIME BEING...AS EACH OPERATIONAL MODEL HANDLES THE
EVOLUTION OF THIS FEATURE DIFFERENTLY...RESULTING IN A LOW
CONFIDENCE FORECAST. AS A RESULT...CONTINUED MOSTLY WITH WHAT WAS
INHERITED IN THE GRIDS FOR MONDAY THROUGH WEDNESDAY MORNING...WITH
THE CHANCES OF CONTINUED BELOW AVERAGE TEMPERATURES LOOKING HIGH FOR
MUCH OF THE AREA.
&&
.AVIATION...FOR MCCARRAN...SOUTHWEST WINDS WITH GUSTS OF 20-30 KTS
AND AREAS OF MECHANICAL TURBULENCE WILL CONTINUE THROUGH THE REST OF
THE MORNING BEFORE A COLD FRONT MOVES INTO THE LAS VEGAS VALLEY
BETWEEN 19-21Z. THIS FRONT WILL TURN THE WINDS TO THE NORTHWEST...AT
LEAST BRIEFLY. WINDS MAY RETURN TO A MORE WEST TO SOUTHWEST
DIRECTION LATER IN THE AFTERNOON OR EARLY EVENING AS THE IMPACT FROM
THE COLD FRONT DIMINISHES. FEW-SCT CLOUDS AOA 8K FEET ARE EXPECTED
THROUGH THE PERIOD. LIGHTER WINDS ARE EXPECTED THROUGH THURSDAY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...GUSTY SOUTHWEST WINDS WILL GIVE WAY TO NORTHWESTERLY
WINDS AS A COLD FRONT PUSHES THROUGH THE REGION TODAY. THE FRONT
WILL DIMINISH IN STRENGTH AS IT MOVES THROUGH THE LAS VEGAS VALLEY.
EXPECT SOME WEAK SHOWER ACTIVITY NEAR THE FRONT AS IT MOVES THROUGH
THE SOUTHERN GREAT BASIN. LIGHTER WINDS ARE EXPECTED ACROSS THE
REGION THURSDAY. SCT-BKN CLOUDS MAINLY AOA 6-8K FEET THROUGH THE
PERIOD...ALONG WITH MECHANICAL TURBULENCE NEAR THE HIGH TERRAIN.
&&
$$
UPDATE...STACHELSKI
SHORT TERM/AVIATION...WOLCOTT
LONG TERM...PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
652 PM EST THU NOV 26 2015
.SYNOPSIS...
A SOUTHERLY FLOW OF MILD AIR WILL CONTINUE THROUGH TONIGHT AND
MOST OF FRIDAY WITH MILD WEATHER CONTINUING. A COLD FRONT WILL
CROSS THE REGION LATE FRIDAY AND FRIDAY NIGHT WITH SHOWERS AND A
RETURN TO MORE SEASONABLY CHILLY AIR FOR LATE NOVEMBER SATURDAY.
THIS DRY AND CHILLY WEATHER WILL LAST INTO EARLY NEXT WEEK BEFORE
THE NEXT STORM SYSTEM AFFECTS OUR AREA TUESDAY AND WEDNESDAY WITH
MORE RAIN SHOWERS EXPECTED AND MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SATELLITE IMAGERY SHOWS PATCHY MIDDLE TO HIGH CLOUDS ADVECTING
OVERHEAD IN ASSOCIATION WITH WARM AIR ADVECTION AROUND 500 MB AND
UP. HENCE FORECAST BEGINS PARTLY CLOUDY ALL AREAS. THE 18Z NAM IS
STILL MOST AGRESSIVE WITH LOW-LEVEL MOISTURE CREEPING UP NORTHWARD
INTO NORTHEAST PA AND SOUTH-CENTRAL NY BETWEEN 00Z AND 09Z AS
SEEN IN THE 925 MB RH FIELDS WHICH BECOME SATURATED. THE HRRR AND
RAP NOW BOTH ARE SUGGESTING LOW-LEVEL MOISTURE CREEPING NORTHEAST
IN NE PA/SC NY BTWN 5 AND 9Z SIMILAR TO NAM. BUT LOOKING AT
SATELLITE AND METARS THIS MOISTURE STILL LOOKS OVERDONE. SO WE
WILL CONTINUE WITH JUST PARTLY CLOUDY SKIES FOR THE OVERNIGHT.
PRECIPITATION WON`T BE ARRIVING BEFORE 12Z FRIDAY SO NO PRECIP IN
FORECAST GRIDS OVERNIGHT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
FOR FRIDAY, ALL SYNOPTIC MODELS CONTINUE TO SHOW THAT THE FRONTAL
SYSTEM WILL REACH LAKES ONTARIO AND ERIE BY 18Z FRIDAY AND TO
ABOUT UTICA TO PENN YAN/HORNELL AREA IN CENTRAL NY BY 00Z. THE 12Z
EUROPEAN MODEL, 15Z SREF AND 12Z NAM ARE SLOWER THAN THE 12Z GFS
WHICH HAS THE FRONT A BIT FARTHER EAST AND SOUTH AT 00Z SATURDAY.
THE 12Z CMC REMAINS THE SLOWEST WITH THIS FRONT HOLDING IT BACK TO
ABOUT SARANAC LAKE TO EXTREME SOUTHWEST NY BY 00Z SATURDAY.
MODELS HAVE TRENDED SLOWER WITH THIS FRONT AND AS A RESULT HAVE
BACKED OFF SHOWERS THAT ARE ACCOMPANYING THIS FRONT SOME. THE
MAIN DYNAMICAL FEATURE THAT WAS SUPPORTING LIFT AND RAIN
SHOWERS MAINLY BEHIND THIS FRONT WAS AN UPPER LEVEL JET STREAK
WHICH EXTENDS BEHIND THE FRONT FROM SOUTHERN QUEBEC NORTHEAST TO
THE MARITIMES AT 00Z SATURDAY. THIS JET WILL CONTINUE TO SHIFT TO
THE NORTHEAST FRIDAY NIGHT AS THE SHORT WAVE THAT WAS ASSOCIATED
WITH IT DEPARTS TO THE NORTHEAST. HENCE SHOWERS SHOULD WEAKEN AS
THE FRONT DROPS SOUTH INTO SOUTHERN NY AND NORTHEAST PA FRIDAY
NIGHT. MODEL QPFS SHOW THIS DROP OFF SIGNIFICANTLY SO HAVE POPS
DROPPING AS THE FRONT MOVES SOUTH FRIDAY NIGHT AND EARLY
SATURDAY.
SOME LINGERING LIGHT RAIN SHOWERS COULD AFFECT NORTHEAST PA AND
SOUTH CENTRAL NY SATURDAY. I KEPT SLIGHT CHANCE FOR SHOWERS GOING
ALL DAY SATURDAY FOR THE COMBINATION OF THE LINGERING
PRECIPITATION WITH THE COLD FRONT AND ALSO THE POTENTIAL FOR A
WAVE TO FORM ALONG THE FRONT AS PER THE 12Z CMC AND EUROPEAN
MODELS. THE GFS AND NAM ARE DRY ALL DAY SATURDAY IN OUR AREA.
USED SUPERBLEND OF MODELS TO COME UP WITH A CONSENSUS FORECAST.
THEN FOR SATURDAY NIGHT HIGH PRESSURE BUILDS IN AND SKIES WILL
TURN FAIR.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ALL MAIN SYNOPTIC MODELS HAVE HIGH PRESSURE AND DRY WEATHER FOR
CENTRAL NY AND NORTHEAST PA ON SUNDAY AND MONDAY. NEXT WINTER
STORM WILL BEGIN TO AFFECT REGION LATE MONDAY NIGHT AND ESPECIALLY
TUESDAY AS A LOW PRESSURE SYSTEM TRACKS NORTHEAST THROUGH THE
GREAT LAKES REGION TUESDAY INTO WEDNESDAY WITH MAINLY RAIN
SHOWERS. AS ANOTHER STRONG SOUTHERLY FLOW OF AIR SETS UP IN THE
LOW-LEVELS OF THE ATMOSPHERE AND LEADS TO MILD CONDITIONS AND RAIN
SHOWERS. THERE BEGINS TO BE TIMING DIFFERENCES WEDNESDAY NIGHT
INTO THURSDAY NEXT WEEK BUT IDEA IS THAT THE LOW WILL TRACK TO OUR
NORTHEAST AND WE WILL SEE A RETURN TO COLDER TEMPERATURES AND A
CHANCE FOR SNOW SHOWERS WEDNESDAY NIGHT WITH FAIR AND CHILLY
WEATHER FOR NEXT THURSDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
DESPITE THE GNRL WSW FLOW MESO SCALE MDLS SHOW LL SLY FLOW
BRINGING MOISTURE INTO AVP...AND PERHAPS BGM. THIS COULD RESULT IN
LATE NGT MVFR CIGS TO AVP...AND OCNL MVFR CIGS TO BGM. OTRW...VFR
CONDS WILL CONT OVRNGT AND INTO FRI. COLD FNT APRCHG LATE IN THE
TAF PD...BUT IS FCST TO CONT TO WEAKEN AND ANY PCPN LOOKS TO BEGIN
AT OR SHRTLY AFT 00Z SAT...SO NO MENTION IN THE TAFS ATTM.
.OUTLOOK...
SAT...POST-FRONTAL MVFR CLOUD DECK...BECOMING VFR.
SUN/MON/TUE...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...DJN
AVIATION...DGM/HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
644 PM EST THU NOV 26 2015
.SYNOPSIS...
A SOUTHERLY FLOW OF MILD AIR WILL CONTINUE THROUGH TONIGHT AND
MOST OF FRIDAY WITH MILD WEATHER CONTINUING. A COLD FRONT WILL
CROSS THE REGION LATE FRIDAY AND FRIDAY NIGHT WITH SHOWERS AND A
RETURN TO MORE SEASONABLY CHILLY AIR FOR LATE NOVEMBER SATURDAY.
THIS DRY AND CHILLY WEATHER WILL LAST INTO EARLY NEXT WEEK BEFORE
THE NEXT STORM SYSTEM AFFECTS OUR AREA TUESDAY AND WEDNESDAY WITH
MORE RAIN SHOWERS EXPECTED AND MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SATELLITE IMAGERY SHOWS PATCHY MIDDLE TO HIGH CLOUDS ADVECTING
OVERHEAD IN ASSOCIATION WITH WARM AIR ADVECTION AROUND 500 MB AND
UP. HENCE FORECAST BEGINS PARTLY CLOUDY ALL AREAS. THE 18Z NAM IS
STILL MOST AGRESSIVE WITH LOW-LEVEL MOISTURE CREEPING UP NORTHWARD
INTO NORTHEAST PA AND SOUTH-CENTRAL NY BETWEEN 00Z AND 09Z AS
SEEN IN THE 925 MB RH FIELDS WHICH BECOME SATURATED. THE HRRR AND
RAP NOW BOTH ARE SUGGESTING LOW-LEVEL MOISTURE CREEPING NORTHEAST
IN NE PA/SC NY BTWN 5 AND 9Z SIMILAR TO NAM. BUT LOOKING AT
SATELLITE AND METARS THIS MOISTURE STILL LOOKS OVERDONE. SO WE
WILL CONTINUE WITH JUST PARTLY CLOUDY SKIES FOR THE OVERNIGHT.
PRECIPITATION WON`T BE ARRIVING BEFORE 12Z FRIDAY SO NO PRECIP IN
FORECAST GRIDS OVERNIGHT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
FOR FRIDAY, ALL SYNOPTIC MODELS CONTINUE TO SHOW THAT THE FRONTAL
SYSTEM WILL REACH LAKES ONTARIO AND ERIE BY 18Z FRIDAY AND TO
ABOUT UTICA TO PENN YAN/HORNELL AREA IN CENTRAL NY BY 00Z. THE 12Z
EUROPEAN MODEL, 15Z SREF AND 12Z NAM ARE SLOWER THAN THE 12Z GFS
WHICH HAS THE FRONT A BIT FARTHER EAST AND SOUTH AT 00Z SATURDAY.
THE 12Z CMC REMAINS THE SLOWEST WITH THIS FRONT HOLDING IT BACK TO
ABOUT SARANAC LAKE TO EXTREME SOUTHWEST NY BY 00Z SATURDAY.
MODELS HAVE TRENDED SLOWER WITH THIS FRONT AND AS A RESULT HAVE
BACKED OFF SHOWERS THAT ARE ACCOMPANYING THIS FRONT SOME. THE
MAIN DYNAMICAL FEATURE THAT WAS SUPPORTING LIFT AND RAIN
SHOWERS MAINLY BEHIND THIS FRONT WAS AN UPPER LEVEL JET STREAK
WHICH EXTENDS BEHIND THE FRONT FROM SOUTHERN QUEBEC NORTHEAST TO
THE MARITIMES AT 00Z SATURDAY. THIS JET WILL CONTINUE TO SHIFT TO
THE NORTHEAST FRIDAY NIGHT AS THE SHORT WAVE THAT WAS ASSOCIATED
WITH IT DEPARTS TO THE NORTHEAST. HENCE SHOWERS SHOULD WEAKEN AS
THE FRONT DROPS SOUTH INTO SOUTHERN NY AND NORTHEAST PA FRIDAY
NIGHT. MODEL QPFS SHOW THIS DROP OFF SIGNIFICANTLY SO HAVE POPS
DROPPING AS THE FRONT MOVES SOUTH FRIDAY NIGHT AND EARLY
SATURDAY.
SOME LINGERING LIGHT RAIN SHOWERS COULD AFFECT NORTHEAST PA AND
SOUTH CENTRAL NY SATURDAY. I KEPT SLIGHT CHANCE FOR SHOWERS GOING
ALL DAY SATURDAY FOR THE COMBINATION OF THE LINGERING
PRECIPITATION WITH THE COLD FRONT AND ALSO THE POTENTIAL FOR A
WAVE TO FORM ALONG THE FRONT AS PER THE 12Z CMC AND EUROPEAN
MODELS. THE GFS AND NAM ARE DRY ALL DAY SATURDAY IN OUR AREA.
USED SUPERBLEND OF MODELS TO COME UP WITH A CONSENSUS FORECAST.
THEN FOR SATURDAY NIGHT HIGH PRESSURE BUILDS IN AND SKIES WILL
TURN FAIR.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ALL MAIN SYNOPTIC MODELS HAVE HIGH PRESSURE AND DRY WEATHER FOR
CENTRAL NY AND NORTHEAST PA ON SUNDAY AND MONDAY. NEXT WINTER
STORM WILL BEGIN TO AFFECT REGION LATE MONDAY NIGHT AND ESPECIALLY
TUESDAY AS A LOW PRESSURE SYSTEM TRACKS NORTHEAST THROUGH THE
GREAT LAKES REGION TUESDAY INTO WEDNESDAY WITH MAINLY RAIN
SHOWERS. AS ANOTHER STRONG SOUTHERLY FLOW OF AIR SETS UP IN THE
LOW-LEVELS OF THE ATMOSPHERE AND LEADS TO MILD CONDITIONS AND RAIN
SHOWERS. THERE BEGINS TO BE TIMING DIFFERENCES WEDNESDAY NIGHT
INTO THURSDAY NEXT WEEK BUT IDEA IS THAT THE LOW WILL TRACK TO OUR
NORTHEAST AND WE WILL SEE A RETURN TO COLDER TEMPERATURES AND A
CHANCE FOR SNOW SHOWERS WEDNESDAY NIGHT WITH FAIR AND CHILLY
WEATHER FOR NEXT THURSDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH TONIGHT WITH THE ONLY FLYING CONCERN TODAY BEING GUSTY
WINDS, ESPECIALLY AT KITH, AND TO A LESSER EXTENT KSYR AND KBGM.
TONIGHT MAINLY VFR BUT SOME LOWER CLOUDS NOW OVER WESTERN VA MAY
TRY TO SNEAK NORTHWARD INTO KAVP AND PERHAPS AS FAR NORTH AS KBGM.
CONFIDENCE NOT HIGH ON THIS AS WE HAVE SOME DIFFERENCES IN THE
COMPUTER MODELS WE USE TO FORECAST. THE BOTTOMLINE THOUGH IS THE
TWO TERMINALS MENTIONED ABOVE HAVE THE HIGHEST THREAT FOR MVFR
AFTER 06Z.
ON FRIDAY MAINLY VFR EARLY, ASIDE FROM ANY LINGERING MVFR AT KAVP
AND KBGM. WHILE THIS TAF SET IS DRY, SHOWERS LIKELY TO BE INCLUDED
IN THE NEXT FEW TAFS UPDATES WITH RAIN LIKELY 21Z FRIDAY THROUGH
OVERNIGHT FRIDAY.
.OUTLOOK...
SAT...POST-FRONTAL MVFR CLOUD DECK...BECOMING VFR.
SUN/MON/TUE...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...DJN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
247 PM EST WED NOV 25 2015
.SYNOPSIS...
STRONG HIGH PRESSURE OVER THE NORTH ATLANTIC WILL CONTROL OUR
WEATHER FOR THE REMAINDER OF THE WEEK. A DRY COLD FRONT WILL DROP
SOUTH ACROSS THE AREA SATURDAY. LOW PRESSURE WILL APPROACH FROM
THE WEST MONDAY AND TUESDAY WITH A SMALL CHANCE FOR SHOWERS
DEVELOPING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM WEDNESDAY...VERY HIGH SURFACE PRESSURES IN PLACE OVER THE
CAROLINAS WITH A 1042MB HIGH OFF NEW ENGLAND COAST EXTENDING A RIDGE
AXIS OF 1036MB INTO THE CAROLINAS. PLENTY OF ATLANTIC MOISTURE SEEN
STREAMING SOUTHWESTWARD AND COAST-PARALLEL (IN THE FORM OF CLOUDS
BUT ALSO A FEW BLIPS ON RADAR) IN THIS FLOW BUT THE COOLER NEARSHORE
WATERS HAVE CREATED JUST ENOUGH INSTABILITY AND SUNSHINE HAS LARGELY
PREVAILED. WITH THE LOSS OF DAYTIME HEATING HOWEVER THIS STABILITY
WILL BE OFFSET AND SOME OF THIS MOISTURE SHOULD START MAKING IT
ASHORE ESPECIALLY AS THE LOW LEVEL FLOW VEERS A BIT ATOP THE SURFACE
LAYER. OTHER THAN PERHAPS A SPRINKLE OR TWO MAINLY ALONG THE
PROTRUDING AREAS LIKE BALD HEAD ISLAND/SOUTHPORT AREAS SHOULD STAY
DRY. THIS IS SUPPORTED BY THE GFS AND NEWER RUNS OF THE HRRR WHEREAS
THE OPERATIONAL 12Z WRF ADVECTS SOME VERY LIGHT RAIN FURTHER INLAND,
SEEMINGLY IN ERROR.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...A REALLY INTERESTING UPPER LEVEL PATTERN
DEVELOPS THANKSGIVING DAY: AN UPPER RIDGE INTENSIFIES ACROSS THE
SE STATES WHILE A SHORTWAVE DISTURBANCE DIVES SOUTHWARD ACROSS
FLORIDA INTO THE BAHAMAS. THIS DISTURBANCE HELPS CUT OFF A BROAD
UPPER LOW ACROSS THE NORTHERN BAHAMAS WHICH THE GFS/ECMWF BOTH
SINK INTO THE CARIBBEAN SEA NEXT WEEK. THE RIDGE OVER US SHOULD
HELP DISSIPATE ANY CIRRUS ADVECTING EASTWARD FROM STORMINESS IN
THE PLAINS STATES AND WILL MAINTAIN A VERY DRY AIRMASS THROUGHOUT THE
MID AND UPPER LEVELS.
BELOW 800 MB (ABOUT 7000 FEET AGL) ONSHORE FLOW FROM THE ATLANTIC
WILL BRING IN MOISTURE...HOWEVER THE GFS/ECMWF MODELS APPEAR LESS
BULLISH ON THE DEPTH AND TIME WHERE ENOUGH MOISTURE WILL BE
PRESENT FOR CLOUD COVER. WATCHING HOW DIFFICULT A TIME THE
ATLANTIC STRATOCUMULUS HAS HAD PUSHING WESTWARD TODAY GIVES ME
PAUSE TO FORECAST ANYTHING WORSE THAN "PARTLY CLOUDY" THURSDAY.
THE LOW LEVELS SHOULD ACTUALLY DRY OUT SLIGHTLY FRIDAY WHICH
SHOULD LEAD TO MOSTLY SUNNY SKIES.
THE 12Z GFS AND 12Z ECMWF MODELS ARE PREFERRED OVER THE 12Z NAM
GIVEN WHAT APPEARS TO BE BETTER HANDLING OF THE DOMINANCE OF THE
WESTERN ATLANTIC HIGH LATER THIS WEEK. THE NAM IS LIKELY WRONG
WITH ITS DEVELOPING SURFACE LOW PRESSURE BETWEEN BERMUDA AND THE
CAROLINAS...THEN PINWHEELING IT WESTWARD AROUND THE TOPSIDE OF
THE UPPER LOW. IN THE NAM THIS FEATURE DISTORTS OUR LOW-LEVEL WIND
PATTERN AND CREATES COLD ADVECTION THAT DOESN`T APPEAR IN THE
OTHER TWO MODELS. FORECAST HIGHS/LOWS HAVE BEEN ADJUSTED VERY NEAR
THE 12Z GFS/ECMWF VALUES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...AMPLIFIED MID LEVEL PATTERN CONTINUES TO GIVE
MEDIUM RANGE GUIDANCE FITS NEXT WEEK. PERIOD BEGINS WITH FLATTENING
5H RIDGE OVERHEAD WITH SURFACE HIGH EXTENDING DOWN THE EAST COAST.
THIS WILL HELP KEEP THE REGION WARM AND DRY SATURDAY AND SUNDAY. MID
LEVEL PATTERN STARTS TO TRANSITION EARLY NEXT WEEK AS THE CLOSED LOW
OVER THE GREAT BASIN SLOWLY STARTS MOVING EAST. MOISTURE ASSOCIATED
WITH A FRONT STALLED OVER THE LOWER MS VALLEY ON SUN WILL WORK ITS
WAY EAST MON INTO TUE. MOISTURE WILL BE LIMITED BY THE TIME IT
REACHES THE LOCAL AREA AND PRECIP POTENTIAL MON INTO TUE LOOKS
LIMITED. THE FRONT ALSO DRIFTS EAST MON/TUE ENDING UP STALLED IN THE
KY/TN VALLEYS AS SURFACE HIGH ALONG THE EAST COAST HOLDS STRONG.
EVENTUALLY 5H LOW EMERGING FROM THE GREAT BASIN WILL PUSH A COLD
FRONT ACROSS THE AREA LATE IN THE PERIOD BUT THE AMOUNT OF MOISTURE
AND PRESENCE OF MID LEVEL DYNAMICS REMAINS IN QUESTION. GIVEN THE
UNCERTAINTY WILL KEEP POP CAPPED AT LOW CHC THROUGH THE PERIOD.
TEMPERATURES WILL REMAIN ABOVE CLIMO.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...HIGH PRESSURE WILL CONTINUE TO CONTROL THE REGION. A
WEAK COASTAL TROUGH WILL PRODUCE STRATOCU THAT WILL HUG THE COAST
THIS AFTERNOON. A CEILING IS POSSIBLE AT THE MYRTLES...HOWEVER SKIES
WILL REMAIN MOSTLY SCATTERED. NORTHEAST FLOW WILL BECOME GUSTY AFTER
SOLAR INSOLATION STARTS THE MIXING PROCESS. LOOK FOR LIGHT NORTHEAST
FLOW THIS EVENING WITH MAINLY A HIGH CLOUD CEILING. MODELS INTRODUCE
FOG/STRATUS OVERNIGHT. THINK INLAND TERMINALS STAND THE BEST SHOT.
THURSDAY...BECOMING VFR WITH A STRATOCU CEILING ALONG THE COAST.
EXTENDED OUTLOOK...MORNING FOG/STRATUS POSSIBLE FRIDAY. UNSETTLED
WEATHER SATURDAY THROUGH MONDAY WITH A CHANCE OF RAIN EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM WEDNESDAY...A MODERATELY STRONG GRADIENT IN PLACE DUE TO
SPRAWLING 1042MB HIGH CENTERED OFF NEW ENGLAND COAST EXTENDING A
RIDGE AXIS INTO THE CAROLINAS. PAIR THE STRENGTH OF THIS FEATURE AND
GRADIENT WITH THE BROAD SWATH OF NORTHEASTERLY FLOW ACROSS A LARGE
PORTION OF THE WESTERN ATLANTIC AND THE STAGE IS SET FOR SOME
ADVISORY-WORTHY WINDS AND SEAS. MOST ZONES WILL AVERAGE 4-6 OR
BRIEFLY 5-7 FT THOUGH THERE WILL BE A VERY NEARSHORE WAVE HEIGHT
SHADOW OFF BRUNSWICK COUNTY COAST.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...1050 MB HIGH PRESSURE OVER NEWFOUNDLAND
WILL MOVE EAST INTO THE NORTH ATLANTIC OCEAN LATER THIS WEEK...
BUT WILL CONTINUE TO EXTEND A RIDGE AXIS SOUTHWESTWARD THROUGH THE
CAROLINAS. THIS WILL MAINTAIN NE WINDS AT A HEFTY 15-20 KT THROUGH
THE PERIOD. WITH SUCH A LARGE PORTION OF THE WESTERN ATLANTIC
AFFECTED BY THESE WINDS LOOK FOR SEAS TO INCREASE TO 7-8 FEET AT
10-20 MILE DISTANCES FROM SHORE NEAR CAPE FEAR AND EAST OF WINYAH
BAY. DOMINANT WAVE PERIODS SHOULD INCREASE TO 8-10 SECONDS.
CONDITIONS WILL BE EVEN ROUGHER OUT NEAR THE GULF STREAM WHERE
CONSIDERABLE SHOWER ACTIVITY MAY ALSO OCCUR ESPECIALLY THURSDAY
AND THURSDAY NIGHT.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...NORTHEAST FLOW WILL CONTINUE THROUGH THE
PERIOD WITH HIGH PRESSURE BUILDING DOWN THE COAST. GRADIENT FOR MUCH
OF THE PERIOD WILL MAINTAIN SPEEDS IN THE 15 TO 20 KT RANGE.
EXTENDED PERIOD OF NORTHEAST FLOW AT OR ABOVE 15 KT WILL KEEP SEAS
ACROSS THE WATERS ELEVATED...ESPECIALLY IN THOSE AREAS EXPOSED TO
NORTHEAST FLOW. SEAS WILL RANGE FROM 3 FT NEAR SHORE TO AS HIGH AS 7
FT NEAR FRYING PAN SHOALS. HEADLINES WILL LIKELY BE NEEDED FOR AT
LEAST THE FIRST HALF OF THE PERIOD.
&&
.TIDES/COASTAL FLOODING...
AS OF 300 PM WEDNESDAY...HIGHER OF TWO DIURNAL CYCLES HAS BEEN
AND WILL CONTINUE TO BE MORNING TIDES. THE RIVERFRONT AT
WILMINGTON HAS BEEN REACHING ADVISORY LEVELS AT BOTH TIDES AS OF
LATE, EVEN THE LOWER EVENING HIGH TIDE. THE FORECAST (WHICH HAS
ERRED SLIGHTLY HIGH) NOW SHOWS A PEAK OF ABOUT 5.4 FT WHICH IS
JUST SHY OF ADVISORY LEVEL OF 5.5 FT MLLW.
TIDES MAY APPROACH MINOR FLOOD LEVELS AT THE BEACHES WITH THURSDAY`S
7 AM HIGH TIDE. ONLY A 0.5 TO 0.7 FOOT ANOMALY WILL BE ENOUGH TO
REACH THE 6.0 FT MLLW FLOOD LEVEL AT WRIGHTSVILLE BEACH AND 7.5 FT
MLLW AT MYRTLE BEACH. THIS APPEARS POSSIBLE GIVEN SUSTAINED
NORTHEAST WINDS EXPECTED OVERNIGHT INTO THURSDAY MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...TRA
NEAR TERM...MBB
SHORT TERM...TRA
LONG TERM...III
AVIATION...DL
TIDES/COASTAL FLOODING...MBB/TRA
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1053 PM CST TUE NOV 24 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 239 PM CST TUE NOV 24 2015
MAIN CONCERNS TONIGHT INTO TOMORROW MOSTLY CENTERED AROUND
FOG/DRIZZLE THREAT. DEW POINTS IN THE MID 30S ACROSS EASTERN
NEBRASKA INTO EASTERN KANSAS THIS AFTERNOON WILL CONTINUE TO ADVECT
NORTHWARD TONIGHT. WITH AN INVERSION IN PLACE AND SNOW COVER THIS
SHOULD LEAD TOWARDS WIDESPREAD STRATUS AND FOG. DRIZZLE WILL ALSO BE
LIKELY...ESPECIALLY AHEAD OF THE INCOMING COLD FRONT. EXPECTING TO
SEE STRATUS AND FOG EXPAND IN COVERAGE FROM ABOUT 2Z THROUGH 9Z WITH
MOST LOCATIONS UNDER STRATUS OR FOG BY 12Z WEDNESDAY. FOR NOW NO
CONCERNS WITH FREEZING DRIZZLE AS IT APPEARS THAT ANY DRIZZLE SHOULD
OCCUR WITH TEMPERATURES MAINLY 34 OR WARMER. THE ONE AREA TO WATCH
MAY BE AROUND THE JAMES VALLEY OR JUST EAST OF THERE WHERE
TEMPERATURES COULD SNEAK DOWN TO 31 OR 32 BY SUNRISE AND CAUSE A
LITTLE FREEZING ON EXPOSED SURFACES AND UNTREATED ROADS. CONFIDENCE
TOO LOW TO INCLUDE AT THIS TIME AND BELIEVE THE THREAT WILL BE EAST
OF THE COLDER TEMPERATURES. WILL HAVE EARLY EVENING LOWS IN THE
EASTERN CWA WITH RISING TEMPERATURES BUT MORE STANDARD LOWS IN THE
WESTERN CWA.
REMOVED ANY MENTION OF RAINFALL FOR WEDNESDAY AS DRY AIR ALOFT WILL
KEEP THE THREAT TO DRIZZLE OR FOG. DO STILL HAVE SOME 20 POPS OVER
PARTS OF NORTHWEST IOWA AS THERE IS A CHANCE SOME OF THIS DRIZZLE
COULD PRODUCE A HUNDREDTH OR TWO TOMORROW AFTERNOON. OTHERWISE HIGHS
MAINLY IN THE UPPER 30S TO MID 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 239 PM CST TUE NOV 24 2015
WEDNESDAY NIGHT WILL SEE SOME SPREAD OF LIGHT RAIN AND DRIZZLE NORTH
ACROSS NORTHWEST IA AND SOUTHWEST MN AS THE LOW LEVEL MOISTURE FLOW
GETS DEEPER. SOME FRONTAL LIFT OF THIS MOISTURE IS LIKELY AND HAVE
KEPT A CHANCE OF LIGHT PRECIPITATION...TENDING TO SNOW WITH THE
COOLING...OVER THE MISSOURI RIVER AREA ALL THE WAY TO CHAMBERLAIN.
SOME MIXED FREEZING RAIN AND SLEET ALSO POSSIBLE IN THE TRANSITION
AREA AS COOLING BEHIND THE FRONT PROGRESSES AND GETS DEEPER.
THANKSGIVING DAY WILL BRING CONTINUED STEADY COOLING WITH LIGHT
PRECIPITATION MAINLY SOUTHEAST HALF. THE PRECIPITATION WILL CONTINUE
TO TREND TO SNOW WITH A MIXTURE PRECEDING. THE PRECIPITATION THREAT
SHOULD PEAK AROUND THE MIDDLE OF THE DAY THEN BEGIN TO DECREASE FROM
THE WEST. GIVEN THE POSITIVE TILT NATURE OF THE SYSTEM AND FAIRLY
QUICK DRYING COMING IN BEHIND THE FRONT...LIKELY TO UNQUALIFIED POPS
WILL BE IN THE FORECAST ONLY FOR NORTHWEST IOWA INTO THE SOUTHEAST
CORNER OF SOUTHWEST MINNESOTA INCLUDING JACKSON. AT THIS TIME THE
SNOWFALL OUTLOOK IS AROUND 2 INCHES IN THIS AREA WITH LESS TO THE
WEST AND NORTH. WINDS WILL GET JUST A BIT ON THE STIFF SIDE BUT NOT
SEEN STRONG ENOUGH AT THIS TIME TO JUSTIFY A MENTION OF BLOWING SNOW
WITH THESE LIMITED AMOUNTS. THE PROBLEM WITH GETTING MORE IS THAT
THE SHORT WAVE COMING UP THE EAST SIDE OF THE SOUTHWESTERN UPPER LOW
IS GOING TO RUN INTO RIDGING FORCED BY THE NORTHERN STREAM WAVE
WHICH HELPS BRING IN THE COLDER AIR...SO THE WAVE WILL BE DAMPENED
OUT AS IT APPROACHES AND THE DECENT FRONTAL BANDING WILL NOT HAVE
MUCH TO WORK ON IT.
SNOW SHOULD MOVE OUT TO THE NORTHEAST OR SIMPLY DISSIPATE OVER THE
AREA THURSDAY NIGHT AND A COUPLE DAYS OF DRY AND COLD WEATHER WILL
ARRIVE. IT LOOKS LIKE THE MAIN UPPER LOW WILL APPROACH BY LATE IN
THE WEEKEND. MODELS DIFFER GREATLY NOT ONLY AMONG EACH OTHER BUT
FROM RUN TO RUN ON HANDLING THIS SYSTEM. A DECENT WAVE COMING UP
TOWARD THE AREA MAY TEND TO RAP BACK AROUND THE UPPER LOW. IN ANY
EVENT THERMAL CONTRAST LOOKS FAIR TO POOR IN THIS PATTERN...SO
DESPITE THE CONSIDERABLE UNCERTAINTY IN MODEL SOLUTIONS...DO NOT
LOOK FOR A BIG STORM THREAT AT THIS TIME. THE GFS SEEMS TO SERVE UP
THE BEST POTENTIAL OF A FEW INCHES OF SNOW WITH ITS POSITIONING OF
THE WAVE BY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1047 PM CST TUE NOV 24 2015
MAIN CHANGE WAS TO SLOW DOWN THE ARRIVAL OF MVFR VISIBILITY AND
LOW STRATUS OVERNIGHT. WITH TEMPERATURES STAYING UP SO FAR THIS
EVENING AND A MORE SUBSTANTIAL DEWPOINT DEPRESSION THIS
EVENING...FOG IS SLOW TO DEVELOP. A BAND OF LOW END VFR STRATUS IS
LIFTING NORTHWARD INTO NORTHWEST IOWA...WHILE HIGH CLOUDS ARE
FILTERING INTO THE WESTERN FORECAST AREA. WHILE MODELS ARE SPLIT
ON THE FOG AND STRATUS POTENTIAL OVERNIGHT...DO THINK THAT THERE
IS ENOUGH OF A POTENTIAL LATER TONIGHT WITH INCREASING
DEWPOINTS...TO LEAVE MENTION OF LOWER VISIBILITY IN FSD AND SUX
AROUND 10 TO 12Z. WITH INCREASING MOISTURE...SOME LOWER STRATUS IS
ALSO LIKELY TO FORM LATE TONIGHT/WEDNESDAY MORNING. STILL A LOT OF
UNCERTAINTY IN TIMING FOR THE LOWER CEILINGS AND HOW LONG
IFR/MVFR CONDITIONS WILL PERSIST WEDNESDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...08
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
940 PM CST THU NOV 26 2015
.UPDATE...
UPDATED TEMPERATURES TONIGHT TO BETTER CAPTURE THE FASTER ARRIVAL
OF FREEZING TEMPS WHILE ALSO BUMPING UP THE START OF FREEZING
RAIN. OPTED TO LEAVE THE ICE STORM WARNING START TIME AT 06Z
DESPITE SOME FREEZING RAIN ALREADY OCCURRING IN OUR NW COUNTIES.
WATER VAPOR IMAGERY SHOWS A DISCERNIBLE AXIS OF STRONGER ASCENT IN
SERN NM COMPLETE WITH CG LIGHTNING WELL BEHIND THE SURFACE FRONT.
DEEP AND MOIST ISENTROPIC ASCENT ATOP THIS SHALLOW COLD DOME WILL
LIKELY ALLOW FOR PRECIP TO FLOURISH IN COVERAGE OVERNIGHT WITH
MULTIPLE AXES OF TRAINING PRECIP POSSIBLE. ON THAT NOTE...THE WTM
NEAR HART HAS ALREADY MEASURED 1/3 INCH OF RAIN IN THE PAST HOUR
UNDER ONE SUCH BAND COINCIDENT WITH FREEZING TEMPS. THE IMPACT TO
AREA ROADS MAY BE WORSE THAN ORIGINALLY EXPECTED GIVEN THE FASTER
ARRIVAL OF FREEZING TEMPS AND MINIMAL RECOVERY ON FRIDAY. IN
EXPECTATION OF SLIGHTLY DEEPER FREEZING LAYER...ADDED SOME SLEET
MENTION AFTER MIDNIGHT IN THE NORTHWEST ZONES BEFORE EXPANDING
THIS SEWD TOMORROW...HOWEVER WE STILL EXPECT FREEZING RAIN TO
DOMINATE THE EVENT AT THIS TIME. REMAINDER OF FORECAST REMAINS ON
TRACK.
&&
.PREV DISCUSSION... /ISSUED 650 PM CST THU NOV 26 2015/
UPDATE...
00Z AVIATION DISCUSSION BELOW. UPDATED TO ADD KING AND STONEWALL
COUNTIES TO ICE STORM WARNING FROM THE EARLIER WINTER STORM WATCH.
UNCERTAINTIES OVER CRITICAL SURFACE TEMPS IN THE ROLLING PLAINS
ARE NO LONGER AS MANY AS BEFORE GIVEN FREEZING TEMPS ALREADY
UPSTREAM IN THE EASTERN TX PANHANDLE...FASTER FROPA AND
CONSISTENT MOS GUIDANCE INDICATING FALLING TEMPS TO AOB FREEZING
IN THE ROLLING PLAINS AFTER MIDNIGHT.
FARTHER WEST ON THE CAPROCK...THERE IS SOME CONCERN THAT THE
FREEZING RAIN AMOUNTS MAY BE TEMPERED BY A DEEPER SUB-FREEZING
COLUMN AS SHOWN BY RECENT RUNS OF THE RAP AND NAM - EFFECTIVELY
SUPPORTING MORE ICE PELLETS /SLEET/ THAN FREEZING RAIN. THESE
MODELS BOTH HAVE FREEZING DEPTHS OF 2000 TO 2500 FEET THICK AT
LUBBOCK WHICH ARE WELL ABOVE THE 1500 FEET OR SHALLOWER WINDOW
IDEAL FOR FREEZING RAIN...HOWEVER OTHER MODELS ARE MORE SHALLOW
WITH THIS CRITICAL LAYER AND SUPPORTIVE OF HEAVY ICING. SEE NO
REASON YET TO DEVIATE FROM THE CURRENT FORECAST AS THIS IS ONLY A
SMALL SAMPLING OF MODELS WITH VARIOUS ENSEMBLES OFFERING NO
CLEARER SOLUTION AT THIS TIME. AIRCRAFT SOUNDING /ACARS/ DATA AT
LBB WILL PROVE CRITICAL IN THE DAYS AHEAD FOR DETERMINING ANY ONE
PREFERENCE OF PRECIP TYPE IN THE NEAR TERM.
AVIATION...
POOR FLYING CONDITIONS WILL PREVAIL THROUGH FRI AND SATURDAY UNDER
LOW CIGS AND ACCUMULATING FROZEN PRECIP...MOSTLY ICE. MVFR CIGS
ARE QUICKLY FALLING TO IFR JUST N OF LBB AND WILL REMAIN AT THESE
LEVELS THROUGH THE TAF PERIOD. AT LBB...AN AIRPORT WEATHER
WARNING AT FOR ACCUMULATING ICE WILL BE ISSUED ONCE CONFIDENCE IN
THE DEVELOPMENT OF FREEZING RAIN BECOMES MORE CERTAIN. CURRENT
FEELING IS THIS SHOULD BE UNDERWAY FROM 09Z-12Z...THOUGH WITH
FREEZING TEMPS ALREADY NOTED SOUTH OF AMA...THIS COULD BE TOO
LATE. EXPECT BREEZY N WINDS OF 15-25 KNOTS THROUGH FRIDAY.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
ICE STORM WARNING UNTIL 6 PM CST SATURDAY FOR TXZ021>044.
&&
$$
93/26
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
650 PM CST THU NOV 26 2015
.UPDATE...
00Z AVIATION DISCUSSION BELOW. UPDATED TO ADD KING AND STONEWALL
COUNTIES TO ICE STORM WARNING FROM THE EARLIER WINTER STORM WATCH.
UNCERTAINTIES OVER CRITICAL SURFACE TEMPS IN THE ROLLING PLAINS
ARE NO LONGER AS MANY AS BEFORE GIVEN FREEZING TEMPS ALREADY
UPSTREAM IN THE EASTERN TX PANHANDLE...FASTER FROPA AND
CONSISTENT MOS GUIDANCE INDICATING FALLING TEMPS TO AOB FREEZING
IN THE ROLLING PLAINS AFTER MIDNIGHT.
FARTHER WEST ON THE CAPROCK...THERE IS SOME CONCERN THAT THE
FREEZING RAIN AMOUNTS MAY BE TEMPERED BY A DEEPER SUB-FREEZING
COLUMN AS SHOWN BY RECENT RUNS OF THE RAP AND NAM - EFFECTIVELY
SUPPORTING MORE ICE PELLETS /SLEET/ THAN FREEZING RAIN. THESE
MODELS BOTH HAVE FREEZING DEPTHS OF 2000 TO 2500 FEET THICK AT
LUBBOCK WHICH ARE WELL ABOVE THE 1500 FEET OR SHALLOWER WINDOW
IDEAL FOR FREEZING RAIN...HOWEVER OTHER MODELS ARE MORE SHALLOW
WITH THIS CRITICAL LAYER AND SUPPORTIVE OF HEAVY ICING. SEE NO
REASON YET TO DEVIATE FROM THE CURRENT FORECAST AS THIS IS ONLY A
SMALL SAMPLING OF MODELS WITH VARIOUS ENSEMBLES OFFERING NO
CLEARER SOLUTION AT THIS TIME. AIRCRAFT SOUNDING /ACARS/ DATA AT
LBB WILL PROVE CRITICAL IN THE DAYS AHEAD FOR DETERMINING ANY ONE
PREFERENCE OF PRECIP TYPE IN THE NEAR TERM.
.AVIATION...
POOR FLYING CONDITIONS WILL PREVAIL THROUGH FRI AND SATURDAY UNDER
LOW CIGS AND ACCUMULATING FROZEN PRECIP...MOSTLY ICE. MVFR CIGS
ARE QUICKLY FALLING TO IFR JUST N OF LBB AND WILL REMAIN AT THESE
LEVELS THROUGH THE TAF PERIOD. AT LBB...AN AIRPORT WEATHER
WARNING AT FOR ACCUMULATING ICE WILL BE ISSUED ONCE CONFIDENCE IN
THE DEVELOPMENT OF FREEZING RAIN BECOMES MORE CERTAIN. CURRENT
FEELING IS THIS SHOULD BE UNDERWAY FROM 09Z-12Z...THOUGH WITH
FREEZING TEMPS ALREADY NOTED SOUTH OF AMA...THIS COULD BE TOO
LATE. EXPECT BREEZY N WINDS OF 15-25 KNOTS THROUGH FRIDAY.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
ICE STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM CST SATURDAY FOR
TXZ021>044.
&&
$$
93/26
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
230 PM CST WED NOV 25 2015
.DISCUSSION...
PRONOUNCED MID/UPPER LOW OVER THE SIERRA MOUNTAIN REGION WILL
CONTINUE TO DIG SWD INTO THE SRN GREAT BASIN WHERE IT WILL REMAIN
THROUGH THE WEEKEND. THIS WILL MAINTAIN BROAD SWLY FLOW ALOFT
ACROSS THE SRN PLAINS AND SUPPLY AMPLE MOISTURE. IN
ADDITION...HURRICANE SANDRA OVER THE ERN PAC WILL CONTINUE TO
CHURN NEWD AND MAKE LANDFALL AS A TS OVER MAINLAND MEXICO EARLY
SUNDAY MORNING...WITH BROAD FEED OF ASSOCIATED TROPICAL MOISTURE
SPREADING INTO TX THROUGH THE WEEKEND. LOW LEVEL GULF MOISTURE
RETURN IS WELL UNDERWAY ACROSS THE LOWER AND MIDDLE TX COAST THIS
AFTERNOON WHICH WILL OVERSPREAD THE REST OF THE UPPER TX COAST
OVER THE NEXT FEW DAYS. THE NET RESULT WILL BE MILD AND UNSETTLED
WEATHER OVER SERN TX INTO THE WEEKEND.
AS MOISTURE RETURN OVERSPREADS THE AREA WE CAN EXPECT A GENERAL
INCREASE IN RAIN CHANCES...MOSTLY AS SCATTERED SHOWERS THURSDAY
AND FRIDAY INCREASING TO STEADIER RAIN IN THE NORTHERN COUNTIES
FRIDAY AND SATURDAY. WILL KEEP CHANCE POPS OVER THE WRN COUNTIES
BEGINNING TOMORROW MORNING WHERE HRRR SPREADS SOME LIGHT SHOWERS
OUT OF CENTRAL TX. HOWEVER...FOR ALL BUT THE IMMEDIATE COAST AND
SERN COUNTIES...PRIMARY RAIN CHANCES BEGIN FRIDAY MORNING AND
CONTINUE INTO SUNDAY. WHILE THE HEAVIEST RAIN WILL LIKELY OCCUR TO
THE NORTH AND WEST OF SOUTHEAST TX...SOME AREAS NORTH OF A
COLUMBUS-CONROE-LIVINGSTON LINE COULD STILL SEE RAIN TOTALS FROM
1-2" BETWEEN FRI AND SUN. MUCH OF THE HOUSTON METRO INTO THE COAST
ARE EXPECTED TO SEE LESSER AMOUNTS.
TEMPERATURES WILL BE QUITE WARM FOR THIS LATE IN NOV WITH
AFTERNOON HIGHS APPROACHING 80F FOR A FEW SPOTS THURSDAY AND
FRIDAY...PRIOR TO THE COLD FRONT SAGGING ACROSS THE AREA SATURDAY.
BEHIND THE FRONT WE WILL LIKELY CUT TEMPS 20 DEGREES FOR HIGHS BY
SUNDAY. WE LOOK TO REMAIN BELOW NORMAL THROUGH NEXT WEEK...WITH
UNSETTLED WEATHER CONTINUING AS MOIST WLY FLOW ALOFT REMAINS IN
PLACE.
48
&&
.MARINE...
FOR TONIGHT...WILL CONTINUE TO CARRY CAUTION FLAGS FOR THE OFFSHORE
WATERS DUE TO THE ELEVATED WINDS AND HIGHER SEAS. NEARSHORE WATER
FORECAST WILL CARRY WINDS AROUND 15 KNOTS...BUT ADD ANOTHER KNOTS OR
TWO AND CAUTION FLAGS WILL BE NEEDED THERE TOO. SLIGHT INCREASE IN
BOTH WINDS AND SEAS IS STILL ANTICIPATED TOMORROW AND FRIDAY.
ADVISORIES WILL LIKELY BE NEEDED OFFSHORE...AND CAUTION FLAGS ARE
EXPECTED FOR THE NEARSHORE WATERS AND MAYBE THE BAYS TOO. EXPECT
GRADUALLY LOWERING WINDS AND SEAS OVER THE WEEKEND WITH THE APPROACH
AND PASSAGE OF A COLD FRONT. THIS FRONT IS CURRENTLY EXPECTED TO MOVE
INTO THE WATERS LATE SATURDAY NIGHT OR EARLY SUNDAY MORNING AND
THROUGH THE AREA DURING THE DAY ON SUNDAY. AT THIS TIME...NO FLAGS
ARE ANTICIPATED BEHIND THIS FRONT DUE TO THE LOW ENOUGH WIND AND SEA
FORECAST. WILL CONTINUE TO MONITOR FOR POSSIBLE SEA FOG FORMATION
OVER THE NEXT COUPLE OF DAYS. ALSO...ELEVATED TIDES AND EXPECTED TO
PERSIST.
42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 65 76 67 75 54 / 20 40 30 70 60
HOUSTON (IAH) 66 77 70 77 62 / 20 20 30 50 40
GALVESTON (GLS) 68 75 69 75 67 / 20 20 20 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 3 PM CST THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE THURSDAY NIGHT
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...48
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
326 PM CST WED NOV 25 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CST WED NOV 25 2015
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED DEEP TROUGHING OVER THE WESTERN U.S. WITH A CLOSED LOW OVER
NEVADA...TROUGHING OVER SOUTH CENTRAL CANADA...AND BROAD RIDGING
FROM TEXAS INTO NEW ENGLAND. REAL ONLY SHORTWAVE OF NOTE WAS IN
NORTHWEST KS. SOUTHERLY LOW LEVEL FLOW UNDERNEATH THE BROAD RIDGING
HELPING TO PROPEL WARMER...MORE MOIST AIR NORTHWARD. 925MB TEMP AT
MPX JUMPED FROM 2C AT 00Z TO 6C AT 12Z. 50F DEWPOINTS WERE
APPROACHING THE IA/MO BORDER...AHEAD OF A COLD FRONT LAYED UP FROM
DLH TO LINCOLN NE. PLENTY OF CLOUDS OVERHEAD WHICH HAS KEPT TEMPS
BACK SOMEWHAT...BUT STILL WARM AND MOIST ADVECTION ALONE HAS PUSHED
READINGS WELL INTO THE 40S AND EVEN A FEW 50S FOR LOCATIONS THAT SAW
SOME PEAKS OF SUN. THE RECENT WARMTH HAS REALLY DENTED THE SNOWPACK
TOO...WITH DEPTHS MOSTLY UNDER 5 INCHES PER 12Z COOP REPORTS...WHICH
HAS GREATLY REDUCED ITS IMPACT ON TEMPERATURES. DESPITE THE
CLOUDS...NO PRECIPITATION HAS OCCURRED YET...AS THE CLOUD LAYER
REMAINS SOMEWHAT SHALLOW AND RELATIVELY SPEAKING HIGH BASED / ALL
EITHER HIGH MVFR OR VFR IN AVIATION TERMS/.
MAIN FOCUS TONIGHT IS ON THE UPPER TROUGH OVER SOUTH CENTRAL CANADA.
AS THIS TROUGH PUSHES SLIGHTLY EAST...WE SEE THE FRONT OFF TO OUR
WEST MOVE ALMOST ALL THE WAY THROUGH THE FORECAST AREA BY 12Z THU.
THE NOCTURNAL INCREASE IN THE LOW LEVEL JET SHOULD HELP TO KEEP
PUSHING WARM/MOIST AIR INTO US...NOTED IN PRECIPITABLE WATER
CLIMBING FROM 0.5-0.75 INCHES AT 18Z TODAY TO 0.75-1 INCH AT 12Z
THU. READINGS WILL LIKELY CLIMB THROUGH THE EARLY OVERNIGHT
TOO...BEFORE FALLING WITH THE FRONTAL PASSAGE. THUS ANTICIPATING
THANKSGIVING DAY CALENDAR HIGH TO OCCUR TONIGHT. THE INCREASE IN
MOISTURE ALSO OCCURS FROM NEAR THE SURFACE TO 6000 FT...WITH WEAK
ISENTROPIC LIFT TAKING PLACE IN THIS LAYER. THEREFORE WE SHOULD SEE
DRIZZLE. IN FACT...LOW LEVEL FRONTOGENESIS INCREASES AFTER MIDNIGHT
IMMEDIATELY IN THE WAKE OF THE FRONTAL PASSAGE...SO SHOULD SEE FLAT
OUT HIGHER QPF / LIGHT RAIN TAKE PLACE. THIS IS ABOUT THE SAME TIME
THAT THE SHORTWAVE IN NORTHWEST KANSAS LIFTS ACROSS THE AREA. BOTH
THE DRIZZLE AND INCREASE IN PRECIPITATION INTENSITY IS EVIDENT IN
ALL MODEL QPF PROGS...WITH VERY LITTLE DIFFERENCE. NOT EXPECTING ANY
PRECIPITATION TYPE CONCERNS TONIGHT...GIVEN TEMPERATURES STAYING
ABOVE FREEZING AND PLENTY OF MID LEVEL DRY AIR ABOVE THE LOWER
CLOUDS TO PRECLUDE ANY SEEDER-FEEDER TO INTRODUCE SNOW CRYSTALS.
THE FORECAST FOR THANKSGIVING DAY GETS MORE INTERESTING. THE TWO
UPPER TROUGHS OFF TO OUR WEST ATTEMPT TO PHASE...WHICH IN TURN
INTENSIFIES THE BAROCLINIC ZONE AROUND THE FRONT THAT MOSTLY PASSED
THROUGH OVERNIGHT...INTENSIFIES THE UPPER JET AND THROUGH THERMAL
WIND RELATIONSHIP...INTENSIFIES THE LOW TO MID LEVEL
FRONTOGENESIS. WITH PRECIPITABLE WATER PROGGED TO HOLD STEADY OR
EVEN INCREASE SLIGHTLY IN OUR SOUTHEAST...THE NET RESULT IS FOR
PRECIPITATION TO INTENSIFY THROUGH THE DAY. THE HEAVIEST
PRECIPITATION...LUCKILY IN THE FORM OF RAIN BUT DEFINITELY NOT
ENOUGH TO CAUSE HYDRO CONCERNS...LOOKS TO FALL IN CLAYTON/GRANT
COUNTIES WHERE THE BEST JUXTAPOSITION EXISTS OF STRONGEST AND
DEEPEST FRONTOGENESIS AND RIGHT ENTRANCE REGION DYNAMICS. WOULD
NOT BE SURPRISED TO EVEN SEE SOME LIGHTNING NEAR DUBUQUE WITH UP
TO 100 J/KG OF MUCAPE PROGGED. FARTHER BACK TO THE NORTHWEST...LOW
LEVEL COLD ADVECTION COMBINED WITH DEEPER SATURATION FROM THE
SURFACE TO THE TROPOPAUSE TO PREVENT LOSS OF SNOW/ICE
CRYSTALS...SHOULD HELP GRADUALLY TURN PRECIPITATION INTO SLEET
THEN SNOW. THIS IS ESPECIALLY TRUE FROM MCW TO RST AND EAU. SINCE
THE FORCING IS WEAKER COMPARED TO CLAYTON/GRANT
COUNTIES...PRECIPITATION IS LIGHTER...BUT STILL LIKELY ENOUGH TO
CAUSE TRAVELING ISSUES. THUS...HAVE ISSUED A WINTER WEATHER
ADVISORY FOR THE NORTHWEST PORTION OF THE FORECAST AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CST WED NOV 25 2015
ON THURSDAY NIGHT THE UPPER TROUGH OVER SOUTH CENTRAL CANADA FINALLY
BEGINS TO MAKE SOME BETTER PROGRESS EASTWARD. THIS WILL HELP TO PUSH
ALL OF THE FORCING...PRECIPITATION AND MOISTURE THAT WAS OVER OUR
REGION THURSDAY AFTERNOON TO THE EAST. APPEARS IT MAY TAKE UNTIL THE
LATE OVERNIGHT HOURS FOR THE PRECIPITATION TO FULLY EXIT OUR AREA.
UNTIL THEN...HOWEVER...PERSISTENT LOW LEVEL COLD ADVECTION NOTED BY
925MB TEMPS FALLING FROM -5C TO 5C AT 00Z FRI TO -8 TO -5C BY 12Z
FRI...COMBINED WITH A DRY SLOT PUNCHING IN SHOULD HELP TRANSITION
PRECIPITATION OVER TO A WINTRY MIX OF SLEET...SNOW AND
DRIZZLE/FREEZING DRIZZLE BEFORE ENDING. NOW...IT IS POSSIBLE THAT
WHEN THE DRY SLOT PUNCHES IN...THE PRECIPITATION ENDS AS WELL AS
NOTED IN THE CURRENT AND PAST RUNS OF THE GFS. APPEARS ANY SNOW OR
FREEZING DRIZZLE ACCUMULATION WILL BE LIGHT...BUT STILL ENOUGH OF AN
IMPACT TO WARRANT THE WINTER WEATHER ADVISORY FOR OUR NORTHWEST.
SNOW/FREEZING DRIZZLE AMOUNT FOR THE SOUTHEAST HALF APPEARS TOO
LITTLE TO WARRANT AN ADVISORY.
WEATHER GOES INTO QUIET AND SEASONABLY COOL LAND FOR FRIDAY INTO THE
WEEKEND AS HIGH PRESSURE MOVES IN AT THE SURFACE...AND THE AREA GOES
UNDER A WEST TO NORTHWEST FLOW ALOFT BY LATE SATURDAY. 925MB TEMPS
HOLD BETWEEN -5 AND -8C FOR FRIDAY INTO SAT MORNING BEFORE WARMING
TO 0 TO -2C SAT AFTERNOON THROUGH SUNDAY. THESE READINGS SUPPORT
HIGHS MAINLY IN THE 30S...THOUGH SOME LOCATIONS WEST OF THE MS RIVER
COULD STAY JUST BELOW 30 ON FRIDAY.
MUCH OF NEXT WEEK PER THE ECMWF/GFS/CANADIAN LOOKS LIKE WE WILL BE
DOMINATED BY THE CURRENT UPPER LOW OVER NEVADA WHICH GRADUALLY MAKES
ITS WAY EASTWARD INTO THE AREA. AHEAD OF THE UPPER LOW COULD SEE
SOME PRECIPITATION MON THROUGH TUESDAY...BUT THEN THE MOISTURE
GETS SHUNTED EASTWARD SUCH THAT ONCE THE UPPER LOW MOVES OVERHEAD
FOR WEDNESDAY...THE PRECIPITATION ENDS. CERTAINLY SOME TIMING AND
OTHER SYNOPTIC DIFFERENCES THUS PRECIPITATION CHANCES ARE ONLY IN
THE 20- 40 RANGE AT THIS TIME. COOL AIR UNDERNEATH THE UPPER LOW
COMBINED WITH PRECIPITATION EXPECTED TO KEEP TEMPERATURES NEAR OR
SLIGHTLY BELOW NORMAL...WHICH RESULTS IN SNOW AS THE MAIN
PRECIPITATION TYPE. DEFINITELY TOO MUCH UNCERTAINTY TO LOOK AT
ACCUMULATIONS AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1146 AM CST WED NOV 25 2015
WITH THE TREND IN THE MODELS SHOWING THAT THE LIFT AND MOISTURE
WILL ARRIVE LATER...DELAYED THE LOWERING OF BOTH THE CEILINGS AND
VISIBILITIES BY 3 TO 6 HOURS AT THE TAF SITES. THIS ALSO IMPACTED
THE ONSET OF THE RAIN IN THE AREA. SOUNDINGS CONTINUE TO SHOW THAT
THE PRECIPITATION WILL REMAIN RAIN AT THE TAF SITES THROUGH
26.18Z...AND THEN GRADUALLY TRANSITION TO A WINTRY MIX BETWEEN
26.18Z AND 27.00Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM NOON THURSDAY TO MIDNIGHT CST
THURSDAY NIGHT FOR WIZ017-029-033-034.
WINTER WEATHER ADVISORY FROM 9 AM THURSDAY TO MIDNIGHT CST
THURSDAY NIGHT FOR WIZ032.
MN...WINTER WEATHER ADVISORY FROM NOON THURSDAY TO MIDNIGHT CST
THURSDAY NIGHT FOR MNZ088-095.
WINTER WEATHER ADVISORY FROM 9 AM THURSDAY TO MIDNIGHT CST
THURSDAY NIGHT FOR MNZ079-086-087-094.
IA...WINTER WEATHER ADVISORY FROM NOON THURSDAY TO MIDNIGHT CST
THURSDAY NIGHT FOR IAZ009-018-019.
WINTER WEATHER ADVISORY FROM 9 AM THURSDAY TO MIDNIGHT CST
THURSDAY NIGHT FOR IAZ008.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1026 PM MST THU NOV 26 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 248 PM MST THU NOV 26 2015
...PERIODS OF SNOW TONIGHT...
...MORE LIGHT SNOW ON FRIDAY...
BUSY DAY OF WX FOR THIS HOLIDAY. LOOKS LIKE MOST AREAS HAVE FINALLY
CHANGED OVER TO ALL SNOW...EXCEPT OVER THE EXTREME SE CORNER OF THE
STATE...WHICH COULD HOLD ON TO SOME FZRA THROUGH THIS EVENING.
HIGHLIGHT IN GENERAL HAVE SO FAR WORKED OUT PRETTY WELL. MAIN
CONCERN IN THE SHORT TERM WILL BE THE SNOW POTENTIAL ESPECIALLY THIS
EVENING. IT LOOKS LIKE THE BEST WINDOW FOR ACCUMULATING SNOW WILL BE
FROM NOW THROUGH 06Z TONIGHT. THE LATEST MODEL RUNS...INCLUDING THE
HI RES WRF...HRRR...AND 18Z NAM...ALL SHOW BANDS OF HEAVY SNOW
DEVELOPING THIS EVENING AND MOVING FROM SW TO NE DURING THIS TIME.
THE QPF FORECAST IS DIFFICULT SINCE IT IS NEXT TO IMPOSSIBLE TO SAY
AT THIS POINT EXACTLY WHERE THESE HEAVY MESOSCALE BANDS DEVELOP...IF
THEY DEVELOP AS PROGGED. IT IS NOT OUT OF THE QUESTION THAT SOME
LOCAL SPOT COULD SEE SIGNIFICANT SNOWFALL TONIGHT IF ONE OF THESE
BANDS IS PERSISTENT OVER THE SAME AREA. THE HRRR HAS THE SNOW
BULLSEYE OVER THE SRN SANGRES AND SPANISH PEAKS...WHILE THE NAM SETS
UP THE HEAVIEST SNOW OVER THE NRN SANGRES AND FREMONT COUNTY.
BASED ON THE LATEST OBS AND MODEL CONSENSUS...APPEARS THE BEST BET
FOR SEEING HIGHER SNOW TOTALS WILL BE OVER THE SANGRES...WETS...AND
SRN I-25 CORRIDOR...AS THESE MESOSCALE BANDS TRANSLATE IN FROM THE
SW. HAVE UPGRADED THIS AREA TO A WINTER STORM WARNING FOR TONIGHT.
EXPECTED SNOWFALL IS IN THE 6-10 INCH RANGE...POSSIBLY HIGHER IN THE
HEAVIEST BAND. RATES OF 1-2 INCHES AN HOUR WILL BE POSSIBLE WITH
THESE BANDS. ELSEWHERE...THE ONGOING FORECAST OF 2-4 INCHES FOR THE
PLAINS AND 4-8 FOR THE MOUNTAINS AND HIGHER TERRAIN LOOKS ON TRACK.
FRIDAY...SHOULD SEE A LULL IN THE ACTION FRIDAY MORNING THROUGH
EARLY AFTERNOON...ESPECIALLY NORTH OF HIGHWAY 50. SOME ISOLD TO
SCT SHSN WILL CONTINUE OVER THE AREA. BY LATE AFTERNOON ANOTHER
WAVE OF SNOW SHOWERS SHOULD DEVELOP FROM THE SW...AND THIS WILL
BRING BACK THE THREAT OF SOME LIGHT SNOW ACCUMS TO THE AREA.
DEPENDING ON WHAT HAPPENS OVERNIGHT...MAY HAVE TO EXTEND SOME OF
THE ONGOING WARNINGS AND/OR ADVISORIES ON FRIDAY. TEMPS WILL BE
WELL BELOW AVG AS H7 TEMPS OF MINUS 15 OR LOWER CONTINUE TO SLIDE
SWD DOWN THE SRN FRONT RANGE. GFS-BASED GUIDANCE SEEMS A TAD TOO
COLD...SO HAVE LEANED TOWARDS THE WARMER NAM WHICH STILL BRINGS
HIGHS ONLY IN THE LOWER 20S ACROSS THE PLAINS. LOOKS LIKE A VERY
RAW DAY ACROSS THE CWA. ROSE
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 248 PM MST THU NOV 26 2015
FRI NIGHT THE UPR LOW WL BE CENTERED OVR THE GREAT BASIN WITH SW
FLOW ALOFT CONTINUING OVR THE FORECAST AREA. AT THE SFC OVR THE ERN
PLAINS...LOW LEVEL UPSLOPE EASTERLY WINDS WL CONTINUE ALONG WITH
THE POTENTIAL FOR LIGHT SNOWFALL. AN UPR LEVEL DISTURBANCE COMING
AROUND THE FRONT SIDE OF THE UPR LOW INTO WRN CO...SHOULD HELP
ENHANCE SNOW CHANCES ACRS THE CONTDVD...ESPECIALLY THE EASTERN SAN
JUAN MTNS...AND COULD INCREASE SNOWFALL OVR THE NRN SANGRES AND
PIKES PEAK AREA.
ON SAT...THERE IS NOT MUCH CHANGE IN THE POSITION OF THE UPR
LOW...AND BY AFTERNOON THE UPR DISTURBANCE SHOULD BE OUT OF THE
AREA. THIS IS EXPECTED TO LEAD TO A DECREASE IN PCPN CHANCES...WITH
GENERALLY JUST SOME ISOLD TO SCT CHANCES IN MOST AREAS. HOWEVER
THERE MAY CONTINUE TO BE PERSISTENT LIGHT SNOWFALL ACRS THE ERN
SAN JUAN MTNS THRU MUCH OF THE DAY. TEMPS ACRS THE SERN PLAINS WL
STILL BE COLD...WITH HIGHS RANGING FROM THE MID 20 TO LOWER
30S...MAYBE A LITTLE WARMER NR THE MTNS. THE SAN LUIS VALLEY
SHOULD SEE HIGHS IN THE UPR 30S TO AROUND 40...WITH MOSTLY 30S IN
THE UPR ARKANSAS RIVER VALLEY.
SAT NIGHT THE UPR LOW IS EXPECTED TO BEGIN LIFTING NORTHEASTWARD
INTO SWRN WY. THIS WL BRING ANOTHER UPR DISTURBANCE THRU WRN CO AND
ANOTHER ROUND OF INCREASED CHANCES FOR SNOW. ANOTHER DISTURBANCE IS
THEN EXPECTED COME AROUND THE UPR LOW DURING THE DAY SUNDAY...ONCE
AGAIN ENHANCING PCPN CHANCES OVR THE MTNS...AND THEN OVR ERN AREAS
SUN NIGHT. TEMPS ON SUN SHOULD BE A LITTLE WARMER OVR THE SERN
PLAINS...BUT STILL BELOW AVERAGE WITH READINGS IN THE 30S TO LOWER
40S. THE UPR ARKANSAS RIVER VALLEY AND SAN LUIS VALLEY SHOULD STILL
SEE HIGHS MOSTLY IN THE 30S.
THE LATEST MODEL RUNS SHOW THE UPR LOW CENTER THEN MOVING INTO
EXTREME NERN CO BY MIDDAY MON...BRINGING WESTERLY WINDS TO THE
FORECAST AREA AND DRIER CONDITIONS BY AFTERNOON. ALTHOUGH THE
CENTRAL MTNS SHOULD STILL BE SEEING SOME LIGHT SNOW. THE UPR LOW IS
THE EXPECTED TO QUICKLY MOVE EAST INTO IA BY TUE MORNING...LEAVING
THE FORECAST AREA WITH DRY CONDITIONS. A WEAK UPR DISTURBANCE IS
FORECAST TO MOVE ACRS THE AREA ON TUE NIGHT AND WED...BUT AT THIS
TIME THE MODELS DO NOT SHOW ANY PCPN ASSOCIATED WITH THIS SYSTEM.
HIGH TEMPS BY WED SHOULD BE AROUND AVERAGE. THU IT LOOKS LIKE A
SHORTWAVE RIDGE WL BE OVER THE AREA FOR ANOTHER DRY DAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1019 PM MST THU NOV 26 2015
KALS...COLD AIR SHOULD START TO MOVE INTO THE VALLEY INTO THE
EARLY MORNING HOURS AND EXPECT SNOW SHOWERS TO DEVELOP OVER THE
VALLEY BY 27/0800 UTC. SHOWERS WILL CONTINUE INTO TOMORROW. MAINLY
MVFR CONDITIONS ARE ANTICIPATED.
KCOS...LOW CIGS AND SNOW SHOWERS WILL CONTINUE INTO AT LEAST
MIDDAY TOMORROW. COULD SEE AN ENHANCED AREA OF STEADIER SNOW AFTER
DURING THE 11 -15 UTC TIME FRAME. MVFR/IFR CONDITIONS ARE
EXPECTED.
KPUB...HEAVIER SNOW SHOULD LET UP AND SHOULD SEE LIGHT SNOW/SNOW
SHOWERS DURING THE EARLY MORNING HOURS. EXPECT LIFR CONDITIONS
TRANSISTIONING INTO IFR EARLY THIS MORNING...THEN BECOMING MVFR
BY LATE MORNING.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 8 AM MST FRIDAY FOR COZ076-077-
081>086-088-089-093>099.
WINTER STORM WARNING UNTIL 8 AM MST FRIDAY FOR COZ072>075-
078>080-087.
WINTER WEATHER ADVISORY UNTIL 5 PM MST SATURDAY FOR COZ067-068.
&&
$$
SHORT TERM...ROSE
LONG TERM...28
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
100 AM EST FRI NOV 27 2015
.SYNOPSIS...
ISSUED AT 1258 AM EST FRI NOV 27 2015
RAIN WILL OVERSPREAD THE ENTIRE AREA TODAY. AREAS OF FOG ARE
EXPECTED TO DEVELOP AS WELL. LOWS WILL RANGE FROM 46 TO 53. HIGHS
IN THE 50S WILL BE REACHED EARLY IN THE DAY...THEN TEMPERATURES
WILL FALL THROUGH THE 40S INTO THE AFTERNOON. LOWS SATURDAY
MORNING WILL BE IN THE UPPER 20S TO LOWER 30S.
&&
.UPDATE...
ISSUED AT 553 PM EST THU NOV 26 2015
GRID/ZONE UPDATE OUT TO SLOW DOWN ARRIVAL OF LARGE BAND OF RAIN
INTO THE FORECAST AREA PRIOR TO 6Z. UPSTREAM TRENDS GIVE LITTLE
HOPE OF ANYTHING MEASURABLE MAKING IT INTO FAR NW AREAS UNTIL
AFTER 4Z AT THE EARLIEST WITH RAP SHOWING EVEN LATER (6 TO 8Z).
WILL TAKE A LOOK AT 00Z SOUNDING DATA ONCE IT COMES IN AS WELL AS
RADAR TRENDS AND SEE IF ADDITIONAL UPDATE IS NEEDED.
OTHERWISE A VERY BALMY, BUT BREEZY THANKSGIVING EVENING WILL BE
IN STORE FOR THE REGION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 347 PM EST THU NOV 26 2015
A COLD FRONT WILL MOVE SOUTHEAST TONIGHT ACROSS THE FORECAST
AREA. LARGE SCALE LIFT WAS WELL AHEAD OF THE FRONT EXTENDING FROM
NORTHEAST ILLINOIS INTO SOUTHERN WISCONSIN AND SOUTHEAST LOWER
MICHIGAN. NUMEROUS SHOWERS WERE OVER THIS AREA. PRECIPITABLE WATER
VALUES WERE SEASONALLY HIGH...HOWEVER... MOST UNSTABLE CAPE VALUES
WERE LESS THAN 100 J/KG THIS AFTERNOON. KEPT THUNDER OUT FOR NOW.
EXPECT RAIN TO DEVELOP TONIGHT AND CONTINUE INTO FRIDAY ON EITHER
SIDE OF THE FRONT. CONCERN FOR HYDRO/FLOOD ISSUES AS ALTHOUGH ALL
THE SNOW HAS MELTED...RAINFALL AMOUNTS TONIGHT INTO FRIDAY MAY BE
ENOUGH TO CAUSE RISES ON RIVERS AND MAY CAUSE PONDING OF WATER AND
POSSIBLY SOME ROAD FLOODING WHERE STORM DRAINS MAY BE PARTIALLY OR
FULLY OBSTRUCTED FROM LEAVES OR GRASS. PLAN TO MENTION THESE
CONCERNS IN AN UPDATED HAZARDOUS WEATHER OUTLOOK.
CLEARING HAD ALLOWED TEMPERATURES TO RISE INTO THE 60S THIS
AFTERNOON...ALTHOUGH CLOUDS SHOULD FILL BACK IN ACROSS THE AREA AS
THE FRONT APPROACHES.
&&DODSON
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 347 PM EST THU NOV 26 2015
SPLIT CONUS FLW TO START WILL GIVE WAY TO ZONAL FLW LT PD. LEAD
NRN STREAM SPLIT SW TROUGH WILL CONT EWD THROUGH SE CANADA SHRT
TERM ALLOWING SFC FNTL BNDRY TO CONT SLOWLY PUSHING OFF TO THE
S/SE W/RAIN LINGERING FRI NIGHT. SFC RIDGE WILL BLD EWD THROUGH
THE SRN LAKES THEREAFTER AS FNTL BNDRY STALLS ACRS THE TN VALLEY
ON SUN.
UPSTREAM DEEP CLOSED LOW OVR THE ROCKIES THEN EJECTS OUT INTO THE
CNTRL PLAINS ON MON AS SFC FNT LIFT BACK NORTH INTO THE OH VALLEY
W/RAIN RTNG PRIMARILY LT MON THOUGH EARLY TUE. VIGOROUS/DEEP
CYCLONIC FLW ACRS THE LAKES TUE NIGHT/WED MAY BRING A FEW SPITS OF
RAIN OR SNOW WITHIN LL CAA WING W/DRY AND SEASONABLY COOL WX XPCD
IN WAKE OF THIS SYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1258 AM EST FRI NOV 27 2015
MID TROPOSPHERIC SHORTWAVE FINALLY PRESSING SOUTHEASTWARD INTO
THE NWRN GREAT LAKES WILL FINALLY PROVIDE PUSH OF UPSTREAM
RAINFALL/LOWERED CIGS/VSBYS INTO NORTHERN INDIANA AROUND DAYBREAK.
WITH ONSLAUGHT OF CONTINUED RAINFALL/COLD AIR ADVECTION ATOP
WARM/WET GROUND HAVE LOWERED CONDS WRT VSBY/CIGS WITH IFR
CONDITIONS EXPECTED FOR MAJORITY OF DAYTIME HOURS. CONTEMPLATED
TEMPO LIFR PD AT KSBN 16-19 UTC FOR 1/2SM FG OVC003/VV003 HOWEVER
OVERALL CHANCES AND WILL REASSES NEED FOR LATER/12 UTC ISSUANCE.
LAGGED/PERTURBED MOIST LAYER LIKELY TO LEND PERSISTENT IFR CIGS AT
KFWA LONGER THAN KSBN AS FRONTAL BOUNDARY LIES OUT ACROSS NORTHERN
OHIO VALLEY BY END OF VALID PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR LMZ043-046.
&&
$$
UPDATE...FISHER
SYNOPSIS...MURPHY
SHORT TERM...SKIPPER
LONG TERM...T
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
340 AM CST FRI NOV 27 2015
.SHORT TERM: (Through Tonight)
Issued at 253 AM CST Fri Nov 27 2015
Focus continues to be precip chances and amounts. Late tonight,
focus turns to winter p-types. No changes to the Flood Watch at this
time.
Cdfnt continues to slowly push swd thru the area early this morning.
Expect this fnt to continue to slowly sink swd and shud be along the
sern CWA boarder around 00z this evening. Mdls are in good agreement
regarding mass fields thru the period. However, there are some
differences regarding how quickly precip will shift swd.
Latest guidance suggests another wave of precip will push nwd into
the area this evening/overnight, which may push precip nwd again.
While some pockets of rain may push further nwd, believe the bulk of
the precip will remain across the srn half or so of the CWA.
Focus shifts to cold temps pushing into the region behind the fnt.
At most sites across the CWA, the max temp has already occurred. Some
areas across ern portions of the CWA may rise a degree or two yet
early this morning. Otherwise, expect temps to fall thru the day.
Temps across the CWA are expected to remain above freezing today,
perhaps not by much. However, freezing temps are expected to filter
into nrn portions of the CWA late tonight. Have continued mention of
FZRA late tonight into Sat morning. Still have not mentioned ice
accum across this area as low chance of occurrence and warm ground
temps shud prevent icing.
Tilly
.LONG TERM: (Saturday through Thursday)
Issued at 339 AM CST Fri Nov 27 2015
(Saturday through Sunday)
Mdls are in fairly good agreement thru this period. However, the
latest NAM ejects the upper low into the Plains earlier than the
consensus, resulting in a deeper low forming over the area and
cooler temps aloft. This soln has not been accounted for in the
current forecast.
A few changes to the prev forecast were made. First, low level
thermal fields are once again warmer than yesterday. Have therefore
trended min temps for Sat and Sun night warmer. This will eliminate
the threat for FZRA as long as this trend continues. Mdls continue
to bring what appears to be the remnants of Hurricane Sandra into
the area on Sun into Sun night. Have raised PoPs across much of the
area to account for this soln.
(Monday through Thursday)
Mdl consensus now develops a sfc low further NW across the Plains.
This results in sly flow early in the period across the region. The
GEM continues to be an outlier and have once again disregarded this
soln. Have also once again therefore trended temps twd a GFS/ECMWF
compromise. Still appears that all precip will be out of the region
by Tues with the remainder of the forecast being dry.
Tilly
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1145 PM CST Thu Nov 26 2015
FROPA has occurred over the last hour at both KCOU and KUIN, which
produced an immediate drop of cigs below 1000 feet, with a dip in
vsbys at KUIN into MVFR cat. Expect IFR cigs to hold tough
at these locations overnight and into at least Friday morning.
MVFR vsbys in moderate to occasionally heavy rain also expected
overnight, with a slow improvement on Friday morning as the
heaviest rain shifts to the south. Meanwhile, STL Metro will
remain in the warm sector for several more hours with VFR cigs aoa
5kft as pre-frontal showers slowly work in from the west, with
LLWS potential due to winds just off the surface in the 40-50kt
range. However, based on latest RUC guidance expect FROPA in the
11-13z time frame, with a rapid drop in conditions much as KCOU
and KUIN experienced between 04-05z. IFR cigs and MVFR vsbys
expected for much of the day on Friday.
Specifics for KSTL: Expect VFR cigs for several more hours as
pre-frontal showers gradually work into the area. Looking for a
rapid deterioration in conditions around 11z as strong cold front
pushes through the TAF area, with cigs immediately dropping into
the 400-700 ft range, with MVFR vsbys in moderate to heavy rain.
Expect IFR cigs and MVFR vsbys to persist for much of the day on
Friday.
Truett
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 52 39 42 39 / 100 90 60 50
Quincy 38 34 39 34 / 80 30 20 30
Columbia 39 34 37 36 / 100 70 50 50
Jefferson City 40 35 38 36 / 100 80 60 50
Salem 60 42 44 40 / 100 100 70 60
Farmington 59 39 42 39 / 100 100 80 70
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Flood Watch through Saturday morning FOR Crawford MO-Franklin MO-
Jefferson MO-St. Charles MO-St. Louis City MO-St. Louis MO-
Washington MO.
Flood Watch through Saturday morning FOR Iron MO-Madison MO-
Reynolds MO-St. Francois MO-Ste. Genevieve MO.
Flood Watch through late tonight FOR Audrain MO-Boone MO-
Callaway MO-Cole MO-Gasconade MO-Lincoln MO-Moniteau MO-
Montgomery MO-Osage MO-Warren MO.
IL...Flood Watch through Saturday morning FOR Madison IL-Monroe IL-
St. Clair IL.
Flood Watch through Saturday morning FOR Clinton IL-Randolph IL-
Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
254 AM CST FRI NOV 27 2015
.SHORT TERM: (Through Tonight)
Issued at 253 AM CST Fri Nov 27 2015
Focus continues to be precip chances and amounts. Late tonight,
focus turns to winter p-types. No changes to the Flood Watch at this
time.
Cdfnt continues to slowly push swd thru the area early this morning.
Expect this fnt to continue to slowly sink swd and shud be along the
sern CWA boarder around 00z this evening. Mdls are in good agreement
regarding mass fields thru the period. However, there are some
differences regarding how quickly precip will shift swd.
Latest guidance suggests another wave of precip will push nwd into
the area this evening/overnight, which may push precip nwd again.
While some pockets of rain may push further nwd, believe the bulk of
the precip will remain across the srn half or so of the CWA.
Focus shifts to cold temps pushing into the region behind the fnt.
At most sites across the CWA, the max temp has already occurred. Some
areas across ern portions of the CWA may rise a degree or two yet
early this morning. Otherwise, expect temps to fall thru the day.
Temps across the CWA are expected to remain above freezing today,
perhaps not by much. However, freezing temps are expected to filter
into nrn portions of the CWA late tonight. Have continued mention of
FZRA late tonight into Sat morning. Still have not mentioned ice
accum across this area as low chance of occurrence and warm ground
temps shud prevent icing.
Tilly
.LONG TERM: (Sunday through Next Thursday)
Issued at 333 PM CST Thu Nov 26 2015
Model solutions have come into much better agreement on mass
fields here, with the wound-up storm system ejecting into the
Plains on Monday and slowly tracking east--north of our region on
Tuesday-- with northwest flow aloft to follow on Wednesday. Large
model spread then resumes for next Thursday, where the EC shows a
much deeper storm trying to take shape for the mid-MS valley than
the GFS.
Either way, pattern is very supportive of keeping the very cold air
locked in Canada. The approach of the main storm system Monday will
allow for one more decent rain chance at all locations after being
largely confined to southern MO and southern IL again on Sunday,
with dry wx for a change Tuesday and Wednesday as high pressure
builds in, and probably will continue into Thursday.
Temps look to be around average for the November-December interface.
TES
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1145 PM CST Thu Nov 26 2015
FROPA has occurred over the last hour at both KCOU and KUIN, which
produced an immediate drop of cigs below 1000 feet, with a dip in
vsbys at KUIN into MVFR cat. Expect IFR cigs to hold tough
at these locations overnight and into at least Friday morning.
MVFR vsbys in moderate to occasionally heavy rain also expected
overnight, with a slow improvement on Friday morning as the
heaviest rain shifts to the south. Meanwhile, STL Metro will
remain in the warm sector for several more hours with VFR cigs aoa
5kft as pre-frontal showers slowly work in from the west, with
LLWS potential due to winds just off the surface in the 40-50kt
range. However, based on latest RUC guidance expect FROPA in the
11-13z time frame, with a rapid drop in conditions much as KCOU
and KUIN experienced between 04-05z. IFR cigs and MVFR vsbys
expected for much of the day on Friday.
Specifics for KSTL: Expect VFR cigs for several more hours as
pre-frontal showers gradually work into the area. Looking for a
rapid deterioration in conditions around 11z as strong cold front
pushes through the TAF area, with cigs immediately dropping into
the 400-700 ft range, with MVFR vsbys in moderate to heavy rain.
Expect IFR cigs and MVFR vsbys to persist for much of the day on
Friday.
Truett
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 52 39 42 39 / 100 90 60 50
Quincy 40 34 39 34 / 80 30 20 30
Columbia 41 34 37 36 / 100 70 50 50
Jefferson City 44 35 38 36 / 100 80 60 50
Salem 59 42 44 40 / 100 100 70 60
Farmington 57 39 42 39 / 100 100 80 70
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Flood Watch through Saturday morning FOR Crawford MO-Franklin MO-
Jefferson MO-St. Charles MO-St. Louis City MO-St. Louis MO-
Washington MO.
Flood Watch from 6 AM CST this morning through Saturday morning
FOR Iron MO-Madison MO-Reynolds MO-St. Francois MO-Ste.
Genevieve MO.
Flood Watch through late tonight FOR Audrain MO-Boone MO-
Callaway MO-Cole MO-Gasconade MO-Lincoln MO-Moniteau MO-
Montgomery MO-Osage MO-Warren MO.
IL...Flood Watch through Saturday morning FOR Madison IL-Monroe IL-
St. Clair IL.
Flood Watch from 6 AM CST this morning through Saturday morning
FOR Clinton IL-Randolph IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1147 PM CST THU NOV 26 2015
.SHORT TERM: (Through Saturday)
Issued at 333 PM CST Thu Nov 26 2015
A strong wound-up storm system over the Great Basin region of the
western CONUS is expected to move little during this period,
maintaining an active southwest flow aloft over our region, and
shooting out pieces of energy or distrbances our way as well.
The first of these disturbances is expected to arrive shortly after
sundown this evening, with essentially a near continuous train thru
late Saturday after that. The effects of the rainfall that this
brings will be further augmented by a slow moving cold front thru
midday Friday and rich moisture from the Gulf of Mexico, some of
which will continue to overspread north of the front after it
passes, into the cold air.
Despite much cooler air ushering in behind the cold front,
temperatures are expected to stay above freezing for most areas thru
this entire period and will keep pcpn-types as all rain. The
exception is expected to be in parts of northeast MO and west-
central IL late Friday night and early Saturday morning, where temps
will be around the freezing mark. Fortunately, much of the pcpn by
that time should be to the south with only light spotty pcpn
currently anticipated.
Otherwise, the main concern will be the prolonged period of heavy
rainfall--especially for parts of southeast MO and far southern IL--
where rainfall totals may top 4 inches into Saturday. The Flood
Watch will continue, with the addition of Audrain and Lincoln
counties in MO, where similar QPF and contingency forecasts for area
rivers and streams exist. An expansion into Marion, Bond, and
Fayette counties in IL was also considered, with timing of onset
enough to give it one more look before making a final call. Even
though rainfall chances remain high into Saturday afternoon and into
Sunday for southeast MO and southern IL, rainfall amounts look light
enough to justify ending the FFA on Saturday as it currently does.
Temps will be quite mild for late November ahead of the front, but
will rapidly drop to below average for daytime maxes behind it, with
readings in some areas not getting out of the 30s. Fortunately,
plenty of warm air aloft should keep the pcpn as rain unless surface
temps can slip below 32F.
TES
.LONG TERM: (Sunday through Next Thursday)
Issued at 333 PM CST Thu Nov 26 2015
Model solutions have come into much better agreement on mass
fields here, with the wound-up storm system ejecting into the
Plains on Monday and slowly tracking east--north of our region on
Tuesday-- with northwest flow aloft to follow on Wednesday. Large
model spread then resumes for next Thursday, where the EC shows a
much deeper storm trying to take shape for the mid-MS valley than
the GFS.
Either way, pattern is very supportive of keeping the very cold air
locked in Canada. The approach of the main storm system Monday will
allow for one more decent rain chance at all locations after being
largely confined to southern MO and southern IL again on Sunday,
with dry wx for a change Tuesday and Wednesday as high pressure
builds in, and probably will continue into Thursday.
Temps look to be around average for the November-December interface.
TES
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1145 PM CST Thu Nov 26 2015
FROPA has occurred over the last hour at both KCOU and KUIN, which
produced an immediate drop of cigs below 1000 feet, with a dip in
vsbys at KUIN into MVFR cat. Expect IFR cigs to hold tough
at these locations overnight and into at least Friday morning.
MVFR vsbys in moderate to occasionally heavy rain also expected
overnight, with a slow improvement on Friday morning as the
heaviest rain shifts to the south. Meanwhile, STL Metro will
remain in the warm sector for several more hours with VFR cigs aoa
5kft as pre-frontal showers slowly work in from the west, with
LLWS potential due to winds just off the surface in the 40-50kt
range. However, based on latest RUC guidance expect FROPA in the
11-13z time frame, with a rapid drop in conditions much as KCOU
and KUIN experienced between 04-05z. IFR cigs and MVFR vsbys
expected for much of the day on Friday.
Specifics for KSTL: Expect VFR cigs for several more hours as
pre-frontal showers gradually work into the area. Looking for a
rapid deterioration in conditions around 11z as strong cold front
pushes through the TAF area, with cigs immediately dropping into
the 400-700 ft range, with MVFR vsbys in moderate to heavy rain.
Expect IFR cigs and MVFR vsbys to persist for much of the day on
Friday.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Flood Watch through Saturday morning FOR Crawford MO-Franklin MO-
Jefferson MO-St. Charles MO-St. Louis City MO-St. Louis MO-
Washington MO.
Flood Watch from 6 AM CST Friday through Saturday morning FOR
Iron MO-Madison MO-Reynolds MO-St. Francois MO-Ste.
Genevieve MO.
Flood Watch through late Friday night FOR Audrain MO-Boone MO-
Callaway MO-Cole MO-Gasconade MO-Lincoln MO-Moniteau MO-
Montgomery MO-Osage MO-Warren MO.
IL...Flood Watch through Saturday morning FOR Madison IL-Monroe IL-
St. Clair IL.
Flood Watch from 6 AM CST Friday through Saturday morning FOR
Clinton IL-Randolph IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1245 AM EST FRI NOV 27 2015
.SYNOPSIS...
A SOUTHERLY FLOW OF MILD AIR WILL CONTINUE THROUGH TONIGHT AND
MOST OF FRIDAY WITH MILD WEATHER CONTINUING. A COLD FRONT WILL
CROSS THE REGION LATE FRIDAY AND FRIDAY NIGHT WITH SHOWERS AND A
RETURN TO MORE SEASONABLY CHILLY AIR FOR LATE NOVEMBER SATURDAY.
THIS DRY AND CHILLY WEATHER WILL LAST INTO EARLY NEXT WEEK BEFORE
THE NEXT STORM SYSTEM AFFECTS OUR AREA TUESDAY AND WEDNESDAY WITH
MORE RAIN SHOWERS EXPECTED AND MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SATELLITE IMAGERY SHOWS PATCHY MIDDLE TO HIGH CLOUDS ADVECTING
OVERHEAD IN ASSOCIATION WITH WARM AIR ADVECTION AROUND 500 MB AND
UP. HENCE FORECAST BEGINS PARTLY CLOUDY ALL AREAS. THE 18Z NAM IS
STILL MOST AGRESSIVE WITH LOW-LEVEL MOISTURE CREEPING UP NORTHWARD
INTO NORTHEAST PA AND SOUTH-CENTRAL NY BETWEEN 00Z AND 09Z AS
SEEN IN THE 925 MB RH FIELDS WHICH BECOME SATURATED. THE HRRR AND
RAP NOW BOTH ARE SUGGESTING LOW-LEVEL MOISTURE CREEPING NORTHEAST
IN NE PA/SC NY BTWN 5 AND 9Z SIMILAR TO NAM. BUT LOOKING AT
SATELLITE AND METARS THIS MOISTURE STILL LOOKS OVERDONE. SO WE
WILL CONTINUE WITH JUST PARTLY CLOUDY SKIES FOR THE OVERNIGHT.
PRECIPITATION WON`T BE ARRIVING BEFORE 12Z FRIDAY SO NO PRECIP IN
FORECAST GRIDS OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
FOR FRIDAY, ALL SYNOPTIC MODELS CONTINUE TO SHOW THAT THE FRONTAL
SYSTEM WILL REACH LAKES ONTARIO AND ERIE BY 18Z FRIDAY AND TO
ABOUT UTICA TO PENN YAN/HORNELL AREA IN CENTRAL NY BY 00Z. THE 12Z
EUROPEAN MODEL, 15Z SREF AND 12Z NAM ARE SLOWER THAN THE 12Z GFS
WHICH HAS THE FRONT A BIT FARTHER EAST AND SOUTH AT 00Z SATURDAY.
THE 12Z CMC REMAINS THE SLOWEST WITH THIS FRONT HOLDING IT BACK TO
ABOUT SARANAC LAKE TO EXTREME SOUTHWEST NY BY 00Z SATURDAY.
MODELS HAVE TRENDED SLOWER WITH THIS FRONT AND AS A RESULT HAVE
BACKED OFF SHOWERS THAT ARE ACCOMPANYING THIS FRONT SOME. THE
MAIN DYNAMICAL FEATURE THAT WAS SUPPORTING LIFT AND RAIN
SHOWERS MAINLY BEHIND THIS FRONT WAS AN UPPER LEVEL JET STREAK
WHICH EXTENDS BEHIND THE FRONT FROM SOUTHERN QUEBEC NORTHEAST TO
THE MARITIMES AT 00Z SATURDAY. THIS JET WILL CONTINUE TO SHIFT TO
THE NORTHEAST FRIDAY NIGHT AS THE SHORT WAVE THAT WAS ASSOCIATED
WITH IT DEPARTS TO THE NORTHEAST. HENCE SHOWERS SHOULD WEAKEN AS
THE FRONT DROPS SOUTH INTO SOUTHERN NY AND NORTHEAST PA FRIDAY
NIGHT. MODEL QPFS SHOW THIS DROP OFF SIGNIFICANTLY SO HAVE POPS
DROPPING AS THE FRONT MOVES SOUTH FRIDAY NIGHT AND EARLY
SATURDAY.
SOME LINGERING LIGHT RAIN SHOWERS COULD AFFECT NORTHEAST PA AND
SOUTH CENTRAL NY SATURDAY. I KEPT SLIGHT CHANCE FOR SHOWERS GOING
ALL DAY SATURDAY FOR THE COMBINATION OF THE LINGERING
PRECIPITATION WITH THE COLD FRONT AND ALSO THE POTENTIAL FOR A
WAVE TO FORM ALONG THE FRONT AS PER THE 12Z CMC AND EUROPEAN
MODELS. THE GFS AND NAM ARE DRY ALL DAY SATURDAY IN OUR AREA.
USED SUPERBLEND OF MODELS TO COME UP WITH A CONSENSUS FORECAST.
THEN FOR SATURDAY NIGHT HIGH PRESSURE BUILDS IN AND SKIES WILL
TURN FAIR.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ALL MAIN SYNOPTIC MODELS HAVE HIGH PRESSURE AND DRY WEATHER FOR
CENTRAL NY AND NORTHEAST PA ON SUNDAY AND MONDAY. NEXT WINTER
STORM WILL BEGIN TO AFFECT REGION LATE MONDAY NIGHT AND ESPECIALLY
TUESDAY AS A LOW PRESSURE SYSTEM TRACKS NORTHEAST THROUGH THE
GREAT LAKES REGION TUESDAY INTO WEDNESDAY WITH MAINLY RAIN
SHOWERS. AS ANOTHER STRONG SOUTHERLY FLOW OF AIR SETS UP IN THE
LOW-LEVELS OF THE ATMOSPHERE AND LEADS TO MILD CONDITIONS AND RAIN
SHOWERS. THERE BEGINS TO BE TIMING DIFFERENCES WEDNESDAY NIGHT
INTO THURSDAY NEXT WEEK BUT IDEA IS THAT THE LOW WILL TRACK TO OUR
NORTHEAST AND WE WILL SEE A RETURN TO COLDER TEMPERATURES AND A
CHANCE FOR SNOW SHOWERS WEDNESDAY NIGHT WITH FAIR AND CHILLY
WEATHER FOR NEXT THURSDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
PATCHY CLOUDS AT 3-5 KFT OVER NORTHEAST PA EARLY THIS MORNING WILL
SPREAD NORTH TO THE SOUTHERN TIER OF NEW YORK BEFORE DAYBREAK.
THESE CLOUDS WILL LIKELY DISSIPATE LATER THIS MORNING. OTHERWISE
SKIES WILL BE OVC TODAY BUT CIGS HEIGHTS WILL BE IN THE VFR
CATEGORY WITH HEIGHTS ABOVE 5000 FT. SOUTHWEST WINDS TO 40 KTS AT
2000 FEET WILL RESULT IN SOME LLWS AT ELM/ITH/SYR/RME UNTIL AROUND
15Z TODAY.
A COLD FRONT WILL CROSS THE AREA THIS EVENING FOLLOWED BY SOME
RAIN SHOWERS AND CIGS LOWERING TO MVFR WITH AREAS OF IFR CIGS
AFTER 03Z SATURDAY. WINDS WILL BE SOUTHWEST AT 10 TO 20 KTS AHEAD
OF THE COLD FRONT TODAY SHIFTING TO NORTHWEST AT 5 TO 15 KTS
TONIGHT.
.OUTLOOK...
SAT...POST-FRONTAL MVFR CLOUD DECK...BECOMING VFR.
SUN/MON/TUE...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...DJN
AVIATION...MSE
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1002 AM EST FRI NOV 27 2015
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 239 AM EST FRI NOV 27 2015
A FRONT WILL PASS INDIANA FROM THE NORTHWEST LATER TODAY...THEN
STALL A LITTLE TO THE SOUTH OF OUR STATE. FROM TONIGHT INTO MONDAY
THE HOOSIER STATE WILL STAY WEDGED BETWEEN THE FRONT AND HIGH
PRESSURE TO OUR NORTH.
TUESDAY AND WEDNESDAY LOW PRESSURE AND AN ASSOCIATED COLD FRONT ARE
PREDICTED TO SLOWLY CROSS INDIANA FROM THE WEST. A HIGH PRESSURE
SYSTEM SHOULD ARRIVE THURSDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1002 AM EST FRI NOV 27 2015
RAIN CONTINUES TO STEADILY OVERSPREAD THE FORECAST AREA AS OF MID
MORNING WITH THE FRONTAL BOUNDARY SLOWLY SAGGING TOWARDS THE
REGION. THE NORTHWEST HALF OF THE FORECAST AREA IS SEEING RAIN
WITH MAINLY DRY CONDITIONS SO FAR TO THE SOUTHEAST. TEMPS WERE
GENERALLY IN THE MID AND UPPER 50S AS OF 15Z.
RAIN...RAIN AND MORE RAIN FOR CENTRAL INDIANA TODAY AND TONIGHT AS
THE AFOREMENTIONED COLD FRONT SAGS INTO THE FORECAST AREA THROUGH
THE AFTERNOON. PRIMARY ISSUES FOR THE MORNING UPDATE IS TO OFFER
BIT MORE DETAIL TO RAINFALL ONSET OVER SOUTHEAST HALF OF FORECAST
AREA AND MAYBE MORE IMPORTANTLY...THE TEMPERATURE FALLS LATER
TODAY AS THE FRONT MOVES INTO CENTRAL INDIANA.
HAVE 100 POPS GOING WHERE IT IS RAINING NOW...BUT HAVE SCALED BACK
POPS QUITE A BIT OVER SOUTHEAST COUNTIES AT LEAST INITIALLY TO
ACCOUNT FOR CURRENT OBS. HRRR/WRF ANALYSIS SHOWING A STEADY
EXPANSION TO THE PRECIP SHIELD OVER THE NEXT SEVERAL HOURS WITH
THE ENTIRE FORECAST AREA IMPACTED BY THE SECOND HALF OF THE
AFTERNOON. WILL HAVE 100 POPS OVER ALL OF CENTRAL INDIANA BY LATE
DAY.
OTHER ISSUE FOCUSES ON TEMPS. HAVE SEEN A QUICK 8-10 DEGREE DROP
WITH THE FRONTAL PASSAGE AT SITES OVER NORTHWEST INDIANA AND
NORTHERN ILLINOIS...AND EXPECT A SIMILAR IMPACT AS THE BOUNDARY
PASSES LATER TODAY. MANY LOCATIONS ARE ALREADY AT THEIR HIGHS FOR
THE DAY WITH JUST SOUTHERN COUNTIES LIKELY TO SEE A FEW DEGREE
CLIMB OVER THE NEXT FEW HOURS BEFORE THE RAIN SETTLES IN. UTILIZED
THE RAP HOURLY GUIDANCE AS A BASE FOR TEMPS THE REST OF THE DAY
WITH SOME ADDITIONAL TWEAKS BASED ON CURRENT OBS. COULD EASILY SEE
A 15 TO 20 DEGREE SPREAD IN TEMPS FROM NORTH TO SOUTH BY SUNDOWN
WITH LOWER 40S OVER THE NORTHERN WABASH VALLEY ALONG WITH A RAW
NORTHERLY WIND. COLDER AND RAINY CONDITIONS WILL CONTINUE TONIGHT.
BUNDLE UP AND BE PREPARED FOR COLDER TEMPS BY LATE AFTERNOON AND
EARLY EVENING. ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
ISSUED AT 239 AM EST FRI NOV 27 2015
THE MAIN PROBLEM IS RAIN CHANCES AS A FRONT LINGERS IN THE AREA.
GIVEN WHERE IT HAS THE LOW...THE NAM QPF FIELDS LOOKS STRANGELY DRY
AT 12Z TOMORROW. THE GFS IS MORE CONSISTENT AND THE HIGHER MAV POPS
ARE PROBABLY BEST.
THE REAL UNCERTAINTY ARRIVES SATURDAY NIGHT. THE MODELS HAVE CHANGED
A LOT WITH EVERY RUN LATELY. GIVEN PROBLEMS COMING TO A CONSISTENT
SOLUTION...AN AN ENSEMBLE EFFECT MAY BE BEST AND SO A MAV MET
CONSENSUS WILL BE USED.
THERE IS SIGNIFICANT DIFFERENCE IN LOWS IN THE NORTHERN COUNTIES
SATURDAY NIGHT WITH THE MAV COOLER. THIS APPARENTLY REFLECTS
DIFFERENT HANDLING BY THE PARENT MODELS OF COOLER DRIER AIR TRYING
TO INFILTRATE. THAT FAR OUT ITS HARD TO BE SURE WHICH IS RIGHT AND
A CONSENSUS SHOULD BE THE MOST SKILLFUL FORECAST FOR NOW.
EXCEPT AS MENTIONED IN THE PREVIOUS PARAGRAPH STATISTICAL GUIDANCE
IS CLOSE FOR THE PERIOD AND CAN BE USED WITH REASONABLE CONFIDENCE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY NIGHT/...
ISSUED AT 244 AM EST FRI NOV 27 2015
THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE RAIN CHANCES IN
ASSOCIATION WITH A POTENT LOW PRESSURE SYSTEM. AN UPPER LOW WILL
ENTER THE CENTRAL PLAINS ON MONDAY WITH A SURFACE LOW JUST OUT
AHEAD OF IT. LATEST SUPERBLEND INITIALIZATION SEEMS TO BE
HANDLING THIS SYSTEM WELL...HIGHLIGHTING HIGHEST RAIN CHANCES ON
MONDAY AND MONDAY NIGHT WITH PASSAGE OF COLD FRONT. SO...WILL NOT
DEVIATE FROM THE LIKELY POPS DURING THAT TIME FRAME. PRECIPITATION
IS STILL EXPECTED TO BE IN THE FORM OF RAIN FOR THE MAJORITY OF
THE EVENT...BUT THERE COULD BE A RAIN/SNOW MIXTURE TUESDAY
NIGHT/WEDNESDAY MORNING ACROSS THE NORTHERN COUNTIES WHEN COLDER
AIR FILTERS INTO CENTRAL INDIANA ON BACK SIDE OF AFOREMENTIONED
COLD FRONT. HIGH PRESSURE WILL RETURN ON WEDNESDAY...RESULTING IN
DRY CONDITIONS THROUGH THE REMAINDER OF THE EXTENDED PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 27/1500Z TAF ISSUANCE/...
ISSUED AT 930 AM EST FRI NOV 27 2015
PUSHED BACK THE TIMING OF MVFR/IFR CONDITIONS BY A COUPLE OF HOURS.
PREVIOUS DISCUSSION FOLLOWS...
POOR FLYING CONDITIONS WILL PREVAIL FOR DURATION OF TAF PERIOD AS
A FRONTAL SYSTEM MOVES THROUGH CENTRAL INDIANA. RAIN IS CURRENTLY
BEGINNING TO IMPACT TAF SITES...AND CONDITIONS ARE EXPECTED TO
RAPIDLY DETERIORATE OVER THE NEXT SEVERAL HOURS. MVFR CONDITIONS
CAN BE EXPECTED BY MID-MORNING...FOLLOWED BY IFR CONDITIONS BY
LATE MORNING. PERSISTENT RAIN COULD CAUSE FURTHER DETERIORATION TO
LIFR CATEGORY BY THIS AFTERNOON...STAYING AT THE IFR/LIFR MARK
THROUGH THE END OF THE TAF PERIOD. MEANWHILE...WINDS WILL START
OUT SOUTHWESTERLY AND GRADUALLY VEER TO THE WEST AND FINALLY
NORTH/NORTHEAST BY THIS EVENING. SUSTAINED SPEEDS WILL RANGE
BETWEEN 12 TO 16 KTS WITH GUSTS UP TO 25 KTS AT TIMES.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...RYAN
SHORT TERM...JK
LONG TERM....TDUD
AVIATION...TDUD/CP
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
413 AM CST FRI NOV 27 2015
.DISCUSSION... SURFACE HIGH PRESSURE CONTINUES TO DOMINATE WEATHER
CONDITIONS ACROSS THE AREA. THIS RIDGE IS CURRENTLY ENCOMPASSES THE
ENTIRE SOUTHEASTERN UNITED STATES. A SURFACE TROUGH IS DRAPED OVER
THE CENTRAL CONUS FROM THE GREAT LAKES SOUTHWESTWARD TO CENTRAL
TEXAS AND THEN TO THE PERMIAN BASIN OF WEST TEXAS. IN THE UPPER
LEVELS...RIDGE CENTERED AROUND THE BAY OF CAMPECHE EXTENDS NORTHEAST
TO THE CENTRAL GULF COAST WHILE UPPER LOW ARE IN PLACE TO THE EAST
OVER THE BAHAMAS AND TO THE WEST NEAR NEVADA. THE LOCAL CWA REMAINS
IN MILD AND HUMID CONDITIONS WITH HIGH PRESSURE ALOFT KEEPING
DAYTIME HIGHS IN THE 70S AND RAIN CHANCES TO A MINIMUM. THERE AREA
FEW ECHOS SHOWING UP ON RADAR AND THE HRRR DOES DEPICT A FEW SHOWERS
TODAY BUT THINKING THE COVERAGE WILL BE TO LOW TO HAVE ANY MENTION
OF RAIN IN THE ZONE FORECAST TODAY THROUGH SATURDAY.
THE UPPER LEVEL LOW CURRENTLY CENTERED WEST OF THE ROCKIES WILL
GRADUALLY ROTATE EAST THROUGH THE WEEKEND. THIS SLOWER MOVEMENT WILL
KEEP THE COLD FRONT CURRENTLY TO THE NORTH NEARLY STATIONARY WELL
NORTHWEST OF THE CWA. MODELS SHOW THAT THIS FRONTAL BOUNDARY WILL
FINALLY START MOVING INTO THE LOCAL REGION EARLY TO MIDDLE OF NEXT
WEEK AS THE UPPER LOW BEGINS TRACKING MORE BRISKLY EAST ACROSS THE
CENTRAL PLAINS. THE E TO ENE TRACK OF THIS LOW WILL RESULT IN A
STRETCHING FRONT AS IT MOVES IN WHICH IS TYPICALLY A FAIRLY LOW
IMPACT EVENT WITH MINIMAL THUNDER THREAT AND GENERALLY LOWER RAIN
COVERAGE. IN FACT...DO NOT HAVE ANY THUNDER IN THE EXTENDING FCST AT
ALL. THE PROGRESSION OF SLIGHT CHANCE TO CHANCE POPS WILL BE FAIRLY
SLOW FROM NW TO SOUTHEAST. THIS RUN MODELS ARE EVEN SLIGHTLY SLOWER
THAN PREVIOUS WITH NWRN ZONES NOT SEEING ANY RAIN UNTIL LATE SUNDAY.
EVEN AS THE BOUNDARY MOVES THROUGH TUESDAY IT IS ENTIRELY POSSIBLE
THAT MANY LOCATIONS IN THE CWA DO NOT SEE RAIN AT ALL. THE ECMWF IS
ON THE WETTER SIDE HOWEVER WITH POP GUIDANCE IN THE 50 TO 70 PERCENT
RANGE VS MEX WHICH IS NOT EVEN HALF THAT. KEPT THE LONG TERM FCST
CLOSE TO THE PREVIOUS WHICH IS ON THE DRIER SIDE OF MODEL GUIDANCE.
MEFFER
&&
.AVIATION... NOT A LOT OF DIFFERENCE BETWEEN LAST 24HR AND THE NEXT.
CEILINGS WILL REMAIN IN THE 1.5K FT AREA THIS MORNING AND RISE TO
AROUND 2-3K FT DURING THE DAY TODAY BUT WILL BE INTERMITTENT AS LOW
LEVEL CLEARING WILL GIVE WAY TO DECKS AROUND 12-15K FT. TONIGHT WILL
BE ABOUT THE SAME AS CEILINGS WILL FALL ONCE AGAIN TO AROUND 1.5K FT
BUT SOME AREAS WILL BE IN AND OUT OF THE LOW LEVEL DECKS. WINDS WILL
BE VERY WEAK TO CALM OVERNIGHT. IF LOW LEVEL CEILINGS CLEAR FOR A
TIME THERE MAY BE SOME LIGHT FOG FORMATION. WILL SHOW THIS AS A
TEMPO GROUP TOWARD THE END OF THE 12Z TAF PACK BUT ONLY BRING DOWN
TO AROUND 3SM.
&&
.MARINE... HIGH PRESSURE OVER THE ATLANTIC COAST LINE WILL BE SLOW
TO MOVE THROUGH THE END OF THE WEEK. GUIDANCE HAS COME IN A LITTLE
SLOWER WITH THE PROGRESSION OF STORM SYSTEM AND HIGH PRESSURE
BREAKING DOWN AND WILL MAINTAIN CURRENT FORECAST WITH A FEW MINOR
TWEAKS. A COLD FRONT WILL PROGRESS SOUTHEASTWARD AND STALL NEAR
TEXARKANA TODAY. AS A RESULT...THE STRONG PRESSURE GRADIENT WILL
REMAIN OVER THE SOUTHERN US AND GULF COASTAL WATERS. EASTERLY WINDS
WILL REMAIN ELEVATED TODAY THEN SHIFT TO SOUTHEAST INTO THE WEEKEND.
THE COLD FRONT IS EXPECTED TO MOVE TO THE COAST AND STALL AGAIN BY
TUESDAY.
&&
DECISION SUPPORT...
DSS CODE....GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 74 58 74 59 / 10 10 10 10
BTR 77 62 77 61 / 10 10 10 10
ASD 74 59 74 58 / 10 10 10 10
MSY 76 63 75 61 / 10 10 10 10
GPT 73 58 72 57 / 10 10 10 10
PQL 75 57 74 54 / 10 10 10 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...COASTAL FLOOD ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
LAZ040-050-058-060>062-064-066>070-072.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ552-555-
570-572-575-577.
SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR GMZ536-538-550-557.
MS...COASTAL FLOOD ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
MSZ080>082.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ555-570-
572-575-577.
SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR GMZ538-550-557.
&&
$$
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
635 AM PST FRI NOV 27 2015
.SYNOPSIS...
A COLD UPPER LOW WILL REMAIN IN PLACE OVER THE WEEKEND...KEEPING
TEMPERATURES 10-15 DEGREES BELOW NORMAL. ISOLATED SNOW SHOWERS ARE POSSIBLE
THROUGH TONIGHT ACROSS THE SOUTHERN SIERRA AND NORTHEASTERN LINCOLN
COUNTY. OTHERWISE EXPECT VARIABLE PASSING CLOUDS THROUGH SUNDAY.
IMPROVING CONDITIONS AND MODERATING TEMPERATURES ARE EXPECTED BY
EARLY NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH SUNDAY.
REX BLOCK PATTERN CONTINUES TO HOLD TONIGHT...KEEPING OUR PERSISTENT
UPPER LEVEL LOW OVER THE REGION AND BELOW AVERAGE TEMPERATURES ON
THE HORIZON THROUGH THE END OF THE WEEKEND. THUS FAR...TEMPERATURES
ARE HOLDING HIGHER THAN EXPECTED IN PORTIONS OF THE FREEZE WARNING
AREA TONIGHT...ESPECIALLY IN THE LAS VEGAS VALLEY WHERE NORTHWEST
WINDS DEVELOPED EARLIER THIS EVENING. THIS CONTINUES TO MIX OUT THE
COLDER AIR AT THE SURFACE...CURRENTLY KEEPING TEMPERATURES GENERALLY
BETWEEN 40-45F ACROSS MOST VALLEY LOCALES AT THE 2AM HOUR. PORTIONS
OF SUMMERLIN AND MOUNTAINS EDGE ARE CURRENTLY COMING IN IN THE MID
TO UPPER 30S AT THIS HOUR.
EXPECT CLOUDS ASSOCIATED WITH A SUB-SYNOPTIC LOW OFF OF THE SOUTHERN
CALIFORNIA COAST TO SPREAD EASTWARD ACROSS THE REGION
TODAY...HELPING TO KEEP TEMPERATURES DOWN. THERE WILL BE SUFFICIENT
ENOUGH MOISTURE COMBINED WITH COLD TEMPERATURE PROFILES TO YIELD
ISOLATED SNOW SHOWERS...MAINLY ACROSS NORTHWESTERN INYO COUNTY AND
NORTHEASTERN LINCOLN COUNTY TODAY AND TONIGHT. LOCAL HI-RES MODELS
AND THE LAST SEVERAL RUNS OF THE HRRR ALSO HINT AT ISOLATED SNOW
SHOWERS DEVELOPING IN THE SPRING MOUNTAINS AND SHEEP RANGE AROUND
20Z THIS AFTERNOON. HOWEVER...ACCUMULATIONS ARE EXPECTED TO BE
MINIMAL IN ALL AREAS.
SUNDAY...00Z OPERATIONAL MODEL GUIDANCE IS IN GOOD AGREEMENT IN A
WEAK SHORTWAVE GETTING PULLED INTO THE STAGNANT LOW...YIELDING A
QUICK INCREASE IN CLOUD COVER ACROSS OUR SOUTHERN ZONES DURING THE
DAY. MORE IMPORTANTLY...GUIDANCE SEEMS TO BE ONBOARD WITH THE
EVOLUTION OF THE NEXT SHORTWAVE THAT WILL KICK OUR STAGNANT LOW
EASTWARD...BREAKING THE REX BLOCK PATTERN. AS A RESULT...CLEARING
SKIES AND A SLIGHT WARMUP WILL BE THE STORY SUNDAY AS OUR LOW
DEPARTS THE AREA AND SHORTWAVE RIDGING BEGINS TO MOVE IN LATE SUNDAY
NIGHT.
.LONG TERM...MONDAY THROUGH THURSDAY.
AFTER A FEW WEEKS OF FAIRLY ACTIVE WEATHER...THE UPCOMING EXTENDED
PERIOD APPEARS TO RELATIVELY TAME. SHORTWAVE RIDGING AND QUIET
WEATHER MONDAY WILL GIVE WAY TO SOME WEAK SHORTWAVE ENERGY MOVING
THROUGH THE REGION. THIS MAY BRIEFLY ENHANCE NORTHERLY WINDS ACROSS
THE REGION TUESDAY...PARTICULARLY IN FAVORED AREAS SUCH AS THE
COLORADO RIVER VALLEY. RIDGING TAKES CONTROL AGAIN FOR WEDNESDAY AND
THURSDAY BRINGING MORE QUIET WEATHER. TEMPERATURES ARE LIKELY TO
CLIMB SLIGHTLY ABOVE NORMAL BY MID-LATE WEEK.
&&
.AVIATION...FOR MCCARRAN...GUSTY NORTHWEST WINDS ARE EXPECTED TO
CONTINUE AT THE TERMINAL THROUGH LATE MORNING...WITH SPEEDS RANDING
BETWEEN 10-15KTS AND GUSTS BETWEEN 20-25KTS AT TIMES. WINDS LOOK
TO DECREASE BY EARLY AFTERNOON AT SPEEDS AROUND 10KTS.
EXPECT THIS PATTERN TO HOLD THROUGH THIS EVENING BEFORE WINDS BECOME
LIGHT AND VARIABLE ONCE AGAIN. EXPECT SCT-BKN CIGS TODAY AOA 15KFT
WITH SCT AS LOW AS 8KFT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...EXPECT GUSTY NORTHERLY WINDS TO CONTINUE AT KVGT
THROUGH DAYBREAK...WITH SPEEDS BETWEEN 10-15KTS AND GUSTS 20-25KTS.
EXPECT NORTHERLY WINDS TO CONTINUE ACROSS THE LAS
VEGAS...OWENS...AND COLORADO RIVER VALLEYS TODAY WITH SPEEDS
GENERAL RANGING BETWEEN 10-15KTS AND GUSTS OF 20-25KTS AWAY FROM
THE LAS VEGAS VALLEY. KDAG WILL SEE VARIABLE DIRECTIONS WITH SPEEDS
GENERALLY REMAINING BELOW 10KTS. EXPECT SCT-BKN CIGS GENERALLY UNDER
10KFT ACROSS THE REGION TODAY...WITH ISOLATED SNSH AND LOCAL
MOUNTAIN OBSCURATIONS POSSIBLE IN THE SOUTHERN SIERRA NEAR KBIH
TODAY.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...PULLIN
LONG TERM.............WOLCOTT
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
328 AM PST FRI NOV 27 2015
.SYNOPSIS...
A COLD UPPER LOW WILL REMAIN IN PLACE OVER THE WEEKEND...KEEPING
TEMPERATURES 10-15 DEGREES BELOW NORMAL. ISOLATED SNOW SHOWERS ARE POSSIBLE
THROUGH TONIGHT ACROSS THE SOUTHERN SIERRA AND NORTHEASTERN LINCOLN
COUNTY. OTHERWISE EXPECT VARIABLE PASSING CLOUDS THROUGH SUNDAY.
IMPROVING CONDITIONS AND MODERATING TEMPERATURES ARE EXPECTED BY
EARLY NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH SUNDAY.
REX BLOCK PATTERN CONTINUES TO HOLD TONIGHT...KEEPING OUR PERSISTENT
UPPER LEVEL LOW OVER THE REGION AND BELOW AVERAGE TEMPERATURES ON
THE HORIZON THROUGH THE END OF THE WEEKEND. THUS FAR...TEMPERATURES
ARE HOLDING HIGHER THAN EXPECTED IN PORTIONS OF THE FREEZE WARNING
AREA TONIGHT...ESPECIALLY IN THE LAS VEGAS VALLEY WHERE NORTHWEST
WINDS DEVELOPED EARLIER THIS EVENING. THIS CONTINUES TO MIX OUT THE
COLDER AIR AT THE SURFACE...CURRENTLY KEEPING TEMPERATURES GENERALLY
BETWEEN 40-45F ACROSS MOST VALLEY LOCALES AT THE 2AM HOUR. PORTIONS
OF SUMMERLIN AND MOUNTAINS EDGE ARE CURRENTLY COMING IN IN THE MID
TO UPPER 30S AT THIS HOUR.
EXPECT CLOUDS ASSOCIATED WITH A SUB-SYNOPTIC LOW OFF OF THE SOUTHERN
CALIFORNIA COAST TO SPREAD EASTWARD ACROSS THE REGION
TODAY...HELPING TO KEEP TEMPERATURES DOWN. THERE WILL BE SUFFICIENT
ENOUGH MOISTURE COMBINED WITH COLD TEMPERATURE PROFILES TO YIELD
ISOLATED SNOW SHOWERS...MAINLY ACROSS NORTHWESTERN INYO COUNTY AND
NORTHEASTERN LINCOLN COUNTY TODAY AND TONIGHT. LOCAL HI-RES MODELS
AND THE LAST SEVERAL RUNS OF THE HRRR ALSO HINT AT ISOLATED SNOW
SHOWERS DEVELOPING IN THE SPRING MOUNTAINS AND SHEEP RANGE AROUND
20Z THIS AFTERNOON. HOWEVER...ACCUMULATIONS ARE EXPECTED TO BE
MINIMAL IN ALL AREAS.
SUNDAY...00Z OPERATIONAL MODEL GUIDANCE IS IN GOOD AGREEMENT IN A
WEAK SHORTWAVE GETTING PULLED INTO THE STAGNANT LOW...YIELDING A
QUICK INCREASE IN CLOUD COVER ACROSS OUR SOUTHERN ZONES DURING THE
DAY. MORE IMPORTANTLY...GUIDANCE SEEMS TO BE ONBOARD WITH THE
EVOLUTION OF THE NEXT SHORTWAVE THAT WILL KICK OUR STAGNANT LOW
EASTWARD...BREAKING THE REX BLOCK PATTERN. AS A RESULT...CLEARING
SKIES AND A SLIGHT WARMUP WILL BE THE STORY SUNDAY AS OUR LOW
DEPARTS THE AREA AND SHORTWAVE RIDGING BEGINS TO MOVE IN LATE SUNDAY
NIGHT.
.LONG TERM...MONDAY THROUGH THURSDAY.
AFTER A FEW WEEKS OF FAIRLY ACTIVE WEATHER...THE UPCOMING EXTENDED
PERIOD APPEARS TO RELATIVELY TAME. SHORTWAVE RIDGING AND QUIET
WEATHER MONDAY WILL GIVE WAY TO SOME WEAK SHORTWAVE ENERGY MOVING
THROUGH THE REGION. THIS MAY BRIEFLY ENHANCE NORTHERLY WINDS ACROSS
THE REGION TUESDAY...PARTICULARLY IN FAVORED AREAS SUCH AS THE
COLORADO RIVER VALLEY. RIDGING TAKES CONTROL AGAIN FOR WEDNESDAY AND
THURSDAY BRINGING MORE QUIET WEATHER. TEMPERATURES ARE LIKELY TO
CLIMB SLIGHTLY ABOVE NORMAL BY MID-LATE WEEK.
&&
.AVIATION...FOR MCCARRAN...GUSTY NORTHWEST WINDS ARE EXPECTED TO
CONTINUE AT THE TERMINAL FOR THE NEXT SEVERAL HOURS...WITH SPEEDS
RANDING BETWEEN 10-15KTS AND GUSTS BETWEEN 20-25KTS AT TIMES. WINDS
WILL DIMINISH AFTER DAYBREAK FOR SEVERAL HOURS BEFORE NORTH TO
NORTHWEST WINDS RESUME BY LATE MORNING AT SPEEDS AROUND 10KTS.
EXPECT THIS PATTERN TO HOLD THROUGH THIS EVENING BEFORE WINDS BECOME
LIGHT AND VARIABLE ONCE AGAIN. EXPECT SCT-BKN CIGS TODAY AOA 15KFT
WITH FEW AS LOW AS 8KFT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...EXPECT GUSTY NORTHERLY WINDS TO CONTINUE AT KVGT
THROUGH DAYBREAK...WITH SPEEDS BETWEEN 10-15KTS AND GUSTS 20-25KTS.
EXPECT NORTHERLY WINDS TO CONTINUE ACROSS THE LAS
VEGAS...OWENS...AND COLORADO RIVER VALLEYS TODAY WITH SPEEDS
GENERAL RANGING BETWEEN 10-15KTS AND GUSTS OF 20-25KTS AWAY FROM
THE LAS VEGAS VALLEY. KDAG WILL SEE VARIABLE DIRECTIONS WITH SPEEDS
GENERALLY REMAINING BELOW 10KTS. EXPECT SCT-BKN CIGS GENERALLY UNDER
10KFT ACROSS THE REGION TODAY...WITH ISOLATED SNSH AND LOCAL
MOUNTAIN OBSCURATIONS POSSIBLE IN THE SOUTHERN SIERRA NEAR KBIH
TODAY. &&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...PULLIN
LONG TERM.............WOLCOTT
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1011 AM EST FRI NOV 27 2015
.SYNOPSIS...
DRY HIGH PRESSURE WILL PREVAIL THROUGH THE FIRST HALF OF THE WEEKEND
BEFORE A COLD FRONT SETTLES INTO THE REGION FROM THE NORTH AND WEST
SUNDAY. COOL AND WET HIGH PRESSURE WILL PREVAIL ON MONDAY AND
TUESDAY. ANOTHER FRONT THEN ARRIVES FROM THE WEST IN THE MIDDLE OF
THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM EST FRIDAY...THE MAIN ADJUSTMENT TO THE FORECAST THIS
MORNING WAS TO INCREASE MAX TEMPERATURES ABOUT A CATEGORY MOST
AREAS. THIS IS SLIGHTLY ABOVE VALUES SUPPORTED BY MORNING SOUNDING
THICKNESSES BUT IS IN LINE WITH BL AND 850 MB TEMP INCREASES OVER
YESTERDAY...WHEN IT WAS QUITE WARM...PLUS WARM HOURLY TEMPS ON THE
LATEST RAP RUN.
OTHERWISE...HIGH PRESSURE CENTERED OVER THE REGION WILL REMAIN IN
PLACE LEADING TO LIGHT NORTHERLY FLOW AT THE SURFACE...WHILE LOW
LEVEL FLOW VEERS SOUTHERLY THROUGH THE DAY TO HELP EROSE ANY
LINGERING MORNING STRATUS. A STRONG UPPER RIDGE OVER THE NORTH
CENTRAL GULF WILL CONTINUE TO EXTEND ATOP THE SOUTHEAST
STATES...EFFECTIVELY REINFORCING THE SURFACE HIGH. FURTHER
WEST...THE FRONTAL SYSTEM RESPONSIBLE FOR WIDESPREAD WINTRY
CONDITIONS ACROSS THE PLAINS STATES IS NOT REALLY EXPECTED TO MAKE
MUCH PROGRESS EASTWARD THROUGH THE PERIOD...LIKELY BEING NEAR/ALONG
THE OH/MS RIVER VALLEYS BY EARLY SATURDAY. MID/HIGH CLOUDS ARE
EXPECTED TO STREAM IN OCCASIONALLY THROUGH THE PERIOD ASSOCIATED
WITH THIS FRONTAL AXIS...CARRIED ALONG BY THE MEAN WESTERLY FLOW
ALOFT. THE FCST REMAINS DRY WITH THE ABOVE MENTIONED SKY COVER
HIGHLIGHTED...ALL WITH ABOVE NORMAL TEMPERATURES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRI...HIGH PRESSURE AND QUASI-ZONAL FLOW WILL
CHARACTERIZE THE PATTERN OVER THE SOUTHEAST CONUS SATURDAY AND
SATURDAY NIGHT...THOUGH ENOUGH MOISTURE IS SEEN IN THE COLUMN TO
EXPECT SOME MID-HIGH CLOUD COVER. PLEASANTLY WARM CONDITIONS WITH MAX
TEMPS ON THE ORDER OF 10 DEGREES ABOVE NORMAL ARE IN STORE FOR
SATURDAY. BY SUNDAY HOWEVER THE PATTERN BEGINS TO CHANGE AS TROUGH
SWINGS OFF THE NEW ENGLAND COAST AND RESULTING CONFLUENCE ALLOWS SFC
HIGH TO BUILD OUT OF CANADA...DRIVING A BACKDOOR COLD FRONT SOUTH
INTO VIRGINIA. ALONG THE SAME BOUNDARY...A WEAK SFC WAVE SHOULD
DEVELOP OVER THE MISSISSIPPI DELTA REGION IN RESPONSE TO WRN CONUS
UPPER CYCLONE. THIS FEATURE MAY INDUCE ENOUGH WARM ADVECTION OVER THE
AREA TO BRING IN PRECIP EARLY IN THE DAY...BUT MORE LIKELY IT WILL BE
SUNDAY NIGHT AS THE FRONT SETTLES SOUTHWARD. COOLER BUT STILL ABOVE
NORMAL TEMPS WILL RESULT SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF EARLY FRI MRNG...BACK DOOR COLD FRONT ASSOC WITH STRONG HIGH
PRESSURE OVER NEW ENGLAND WILL SET UP EARLY MONDAY...AND THOUGH LOW
LEVELS REMAIN MOIST...SOME DRYING OCCURS BRIEFLY ALOFT. GFS AND EC
PRODUCE MOST OF THEIR QPF NORTH OF THE CWFA WELL N OF THE WEDGE
BOUNDARY. AS MIDLEVEL HEIGHTS BEGIN TO FALL AHEAD OF NEXT MISSISSIPPI
VALLEY SYSTEM...A SLIGHT UPTICK IN WAA AND MOISTURE FLUX OCCURS MON
NIGHT AND TUE WHICH IMPLIES BETTER PRECIP COVERAGE. HOWEVER THE SETUP
DOES NOT LOOK PARTICULARLY SUPPORTIVE OF HEAVY RAIN...WITH GFS PWATS
REMAINING AROUND 1 INCH AND LLVL WIND SPEEDS BEING RELATIVELY TAME
PRIOR TO COLD FROPA WED. COLD ADVECTION AND NW FLOW BEHIND THIS FRONT
ARE SOMEWHAT SHORT-LIVED...AS GLOBAL MODELS INDICATE A SRN STREAM
SHORTWAVE WILL INTERACT WITH THE FRONT OVER NRN FLORIDA BY EARLY FRI.
IN THE WEDGE MON-TUE...EXPECT NEAR-NORMAL MAX TEMPS BUT WITH WARM
MINS. SLIGHTLY ABOVE NORMAL TEMPS IN DOWNSLOPING FLOW WED WILL BE
FOLLOWED BY COLDER AIR FOR THE LATE WEEK.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS ARE GENERALLY EXPECTED
THROUGH THE PERIOD AS HIGH PRESSURE PREVAILS. ANY LINGERING LOWER
STRATUS NEAR THE BLUE RIDGE ESCARPMENT WILL ERODE THROUGH LATE
MORNING. OTHERWISE...HIGH CIRRUS WILL DOMINATE THE SKIES WITH A
GRADUAL LOWERING TO THE MID LEVELS THROUGH THE LATER HALF OF THE TAF
CYCLE. GUIDANCE DOES FAVOR WIDESPREAD LOWERING OF VSBY DUE TO FOG
ON SATURDAY MORNING AS THE BOUNDARY LAYER DECOUPLES AMIDST LIGHT
WINDS...HOWEVER DUE TO ONLY MODEST CONFIDENCE...OPTED TO ONLY
INCLUDE MVFR OUTSIDE OF THE MTNS/FTHILLS SITES. WINDS WILL REMAIN
LIGHT/NORTHERLY THROUGH THE PERIOD.
OUTLOOK...DRY THROUGH THE FIRST HALF OF THE WEEKEND AS HIGH
PRESSURE PREVAILS AHEAD OF A BACK DOOR FRONT ON SUNDAY/MONDAY.
ANOTHER SYSTEM WILL APPROACH FROM THE WEST ON TUESDAY YIELDING
CONTINUED PRECIPITATION CHANCES WITH RESTRICTIONS.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-12Z
KCLT HIGH 96% HIGH 100% HIGH 100% HIGH 89%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% MED 77%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 89%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 83%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 94%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...WIMBERLEY
NEAR TERM...CDG/HG
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...CDG/HG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
944 AM CST FRI NOV 27 2015
.UPDATE...
LATEST RADAR IMAGERY SHOWS A FEW LIGHT RAIN SHOWERS JUST
WEST/NORTHWEST OF THE CWA WITH SOME SPRINKLES LIKELY REACHING THE
GROUND OVER NORTHWEST ZONES. REGIONAL RADAR SHOWS LIGHT RAIN AS
FAR SOUTH AS NORTHERN MISSISSIPPI...AND LATEST HRRR MODEL RUNS
INDICATE LIGHT RAIN AND SPRINKLES WILL CONTINUE TO PROGRESS
NORTHEAST INTO NORTHWEST ZONES THROUGH THE AFTERNOON. MADE SLIGHT
TWEAKS TO THE SLIGHT CHANCE POPS THROUGH THE AFTERNOON AND WILL
MENTION SPRINKLES TO THE SOUTHEAST OF THAT AREA. HOWEVER...MORE
SIGNIFICANT RAINFALL WILL NOT ARRIVE UNTIL THIS EVENING ACROSS
NORTHWEST PARTS OF THE MID STATE. HIGHS FOR TODAY STILL SEEM
REASONABLE IN THE MID 60S TO LOWER 70S...BUT DID NUDGE THEM DOWN A
DEGREE IN NORTHWEST ZONES DUE TO CLOUD COVER AND PRECIP. REST OF
FORECAST IS ON TRACK.
SHAMBURGER
&&
.PREV DISCUSSION...
UPDATE...FOR 12Z AVIATION DISCUSSION.
AVIATION UPDATE...12Z AVIATION DISCUSSION.
RIDGING INFLUENCES SHOULD KEEP MID STATE DRY THRU 28/00Z WITH SLY
WINDS 5-10 KTS AND BKN CI EXPECTED. SLOW MOVING FRONTAL SYSTEM SHOULD
BEGIN INFLUENCING CKV WX BY NO LATER THAN 28/01Z. AS LOW LEVEL GRADUALLY
MOISTEN...LOOK FOR A SLOW PROGRESSION FROM VFR TO IFR CEILINGS CKV
WITH MVFR VSBYS 28/05Z-28/12Z. EXPECT VFR CONDITIONS THRU 28/12Z BNA/CSV
WITH LOW LEVEL STRATUS FORMATION 28/06Z-28/12Z BNA. MVFR VSBYS DUE TO
LIGHT SHWRS ARE EXPECTED BY 28/09Z. CONTINUED PERSISTENCE OF SLY SFC
WINDS AROUND 5KT EXPECTED 28/00Z-28/12Z.
PREV DISCUSSION...
SHORT TERM(TODAY-SUN)...
UPPER LEVEL LOW OVER THE WESTERN U.S. HAS MOVED VERY LITTLE OVER
THE PAST 24 HRS. IT IS THE EVENTUAL EASTWARD MOVEMENT OF THIS
FEATURE THAT WILL BEGIN TO TILT THE WEATHER PATTERN TOWARD A MORE
PROGRESSIVE ONE. IN THE MEANTIME...LATEST NATIONAL RADAR IMAGERY
SHOWS A LARGE AREA OF PRECIPITATION ACROSS THE MID WEST
SOUTHWESTWARD THROUGH THE CENTRAL AND SOUTHERN PLAINS. THE EASTERN
EXTENT OF THE RAIN AREA IS INTO MUCH OF MO AND AR.
ACROSS THE SOUTHEASTERN U.S....AN UPPER LEVEL RIDGE STRETCHES FROM
THE NRN GULF TO THE CAROLINAS. ADDITIONALLY...SFC RIDGING IS LOCATED
OVER THE MID ATLANTIC AND REACHES SOUTHWESTWARD. A RATHER STRONG SUB
POLAR JET IS LOCATED BETWEEN THE UPPER RIDGE AND THE UPPER TROUGH
AXIS OVER THE WEST.
WITH TIME...THE JET WILL SETTLE SLOWLY SOUTHEASTWARD BRINGING AN
EVENTUAL INCREASE TO OUR POPS HERE IN MIDDLE TN. THE POP BREAKDOWN
LOOKS LIKE GENERALLY LOW POPS THROUGH SATURDAY. THE EXCEPTION WILL
BE OUR NORTHWEST CORNER WHERE THE POPS WILL QUICKLY RAMP UP INTO THE
LIKELY TO DEFINITIVE CATEGORY. BY SAT NT AND SUN...POPS WILL RAMP UP
AREA WIDE AS AN INVERTED SFC TROUGH BEGINS TO AMPLIFY AND IMPULSES
BECOME MORE PREVALENT WITHIN THE SOUTHWESTERLY FLOW.
AS FAR AS QPF AMOUNTS THOUGH SUN NT GOES...WE COULD SEE AS MUCH AS
2 TO 2 1/2 INCHES FAR NW...WITH AN INCH OR SO EAST.
FOR THE NEAR TERM TEMPS...MILD CONDITIONS WILL BE HERE FOR A WHILE.
LOW TEMPS WILL RUN ABOUT 20 DEGREES ABOVE NORMAL WITH LOWS EXPECTED
TO BE MOSTLY IN THE 50S. HIGHS WILL ALSO BE WARMER THAN NORMAL BY 10
TO 15 DEGREES OR SO. THE DAILY RECORDS FOR THE WARMEST MIN TEMPS
ARE WELL INTO THE 60S...SO NO RECORD BREAKING WARMTH IS EXPECTED IN
TERMS OF OUR MILD MINS COMING UP.
LONG TERM(MON-THU)...
THE SLY SFC TO SWLY UPPER LEVEL MOISTURE RICH FETCH PATTERN WILL
CONTINUE TO BE IN PLACE FOR THE FIRST PART OF NEXT WORK WEEK.
THUS...EXPECT WET WX PATTERN TO CONTINUE THRU AT TUE AFTERNOON
ACROSS THE MID STATE...AS FINALLY A SURFACE COLD FRONT PUSHES
THRU THE REGION BY TUE AFTERNOON. BELIEVE PCPN WILL BE OF SHWR
NATURE OUT AHEAD OF FRONTAL PASSAGE WITH SOME WRAP AROUND MOISTURE
BEHIND PASSAGE...RESULTING IN LIGHT RAIN ACROSS THE AREA TUE
NIGHT. BEST POTENTIAL FOR MODERATE RAINFALL CONTINUE TO LOOK LIKE
IT WILL BE DURING THE DAY ON MON. SFC HIGH PRESSURE INFLUENCES
FROM THE ROCKIES WILL THEN TRY TO BUILD INTO THE MID STATE AS WED
PROGRESSES...AND SHOULD PROVIDE DRY CONDITIONS ACROSS AT LEAST NW
PORTIONS OF MID STATE...BUT A PASSING WEAK UPPER LEVEL SHORTWAVE
IN CONTINUANCE OF THE ABOVE MENTIONED SWLY FLOW PATTERN ALOFT COULD
RESULT IN LIGHT SHWRS ACROSS REMAINDER OF MID STATE AS WED PROGRESSES.
EXPECT THE MID STATE TO REMAIN DRY ON WED NIGHT BEFORE YET ANOTHER
UPPER LEVEL SYSTEM MOVES INTO THE AREA FROM THE SW...PER LEAN TOWARD
LATEST GFS SOLUTION...THU AFTERNOON PROGRESSES...RESULTING IN AT
LEAST A SLIGHT CHANCE OF SHWRS DURING THE AFTERNOON HRS ON THU
ACROSS THE MID STATE.
AS FOR TEMPS...LOOK FOR SEASONAL WARM TEMPS TO CONTINUE ACROSS THE
MID STATE THRU TUE AFTERNOON. AFTER FRONTAL PASSAGE...PER ABOVE
MENTIONED SFC HIGH PRESSURE INFLUENCES FROM THE ROCKIES...A CAA
PATTERN WILL SET IN RESULTING IN TEMPS FALLING TO AROUND SEASONAL
NORMAL VALUES AS THE END OF NEXT WORK WEEK APPROACHES.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 56 67 54 61 / 30 50 70 80
CLARKSVILLE 56 65 52 60 / 80 80 80 80
CROSSVILLE 51 65 51 59 / 10 20 50 70
COLUMBIA 54 68 54 61 / 20 30 70 80
LAWRENCEBURG 54 68 55 61 / 10 20 60 80
WAVERLY 56 66 54 61 / 50 60 80 80
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
554 AM CST FRI NOV 27 2015
.DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION.
&&
.AVIATION...
AS OF 11Z...ONLY KIAH/KHOU WERE EXPERIENCING IFR/LIFR CIGS DUE TO
SEA FOG DEVELOPING OFF GALVESTON BAY. EXPECT LOW CIGS AT THESE
TERMINALS THROUGH 14-15Z THIS MORNING. OTHERWISE WE HAVE A HODGE
PODGE OF CEILINGS ACROSS THE AREA WITH VFR AT KGLS/KLBX AND MVFR
FOR KSGR/KCXO/KUTS/KCLL. OVERALL THINK CEILINGS RISE TO
2000-3000FT LEVELS WITH VFR/MVFR CIGS THROUGH THE AFTERNOON MUCH
LIKE YESTERDAY. CIGS THEN DROP AFTER SUNSET TO MVFR AND THEN IFR
AS NO REAL CHANGE IN THE AIRMASS. THAT CHANGE IN AIRMASS IS COMING
IN THE FORM OF A COLD FRONT. ADDED WIND SHIFT FOR MOST TAFS FROM
00Z TO 09Z SAT FOR ALL TAFS EXCEPT FOR KLBX/KGLS WHERE THE FRONT
MIGHT NOT REACH ASSUMING IT STALLS. BASED FROPA ON LATEST HRRR AND
WRF ARW/NMM RUNS. FRONT SEEMS TO BE MOVING FASTER THAN THESE
MODELS ANYWAY. THIS PUTS THE FRONT INTO KCLL RIGHT AROUND 00Z AND
THEN KIAH AROUND 09Z SO IT DOES TAKE ITS TIME PUSHING SOUTH AND
WHY IT MAY STALL. ALSO NOTE THAT THIS IS ABOUT 6-12 HOURS FASTER
THAN THE LATEST NAM/GFS RUNS. BASICALLY THE FROPA AND WIND SHIFT
IS A LOW CONFIDENCE FORECAST BUT ONE THAT COULD REASONABLY OCCUR.
SUSPECT THAT THE TIMING OF THE WIND SHIFT AND FRONT WILL CHANGE
WITH BETTER GUIDANCE AND FUTURE TAF UPDATES. REGARDLESS OF WHEN
THE FRONT PUSHES THROUGH...CIGS MAY NOT CHANGE MUCH AND REMAIN IN
THE IFR/MVFR CATEGORIES GOING INTO SATURDAY.
39
&&
.PREV DISCUSSION... /ISSUED 438 AM CST FRI NOV 27 2015/
DISCUSSION...
SE TEXAS CONTINUED BETWEEN AN UPPER LEVEL RIDGE OVER THE GULF OF
MEXICO AND AN UPPER LEVEL TROUGH ACROSS THE NORTHERN PLAINS AND
CENTRAL ROCKIES. A COLD FRONT WAS ALSO MOVING SLOWLY THROUGH THE
NORTHERN AND CENTRAL PORTIONS OF THE STATE AT 4 AM. BECAUSE OF
THE PROXIMITY OF THE UPPER LEVEL HIGH PRESSURE RIDGE...THE BEST
MOISTURE AXIS WAS ACROSS CENTRAL AND NORTHERN TEXAS EARLY THIS
MORNING. THE MAIN FORECAST ITEM OF CONCERN INCLUDE INCREASING RAIN
CHANCES TODAY THROUGH THE WEEKEND AS A COLD FRONT MOVES INTO THE
AREA.
THERE WERE SOME SLIGHT MODEL DIFFERENCES REGARDING THE TIMING OF
THE COLD FRONTAL PASSAGE. A MODEL CONSENSUS HAS THE FRONT ENTERING
THE COLLEGE STATION AREA DURING THE EARLY EVENING PERIOD LATER
TODAY. THE FRONT WILL THEN BE SLOW TO MOVE THROUGH THE FORECAST
AREA TONIGHT AND SATURDAY...AND MAY STALL BEFORE REACHING THE
COAST DURING THE DAY ON SUNDAY. A CONSENSUS OF THE MODELS HAS THE
BEST CHANCES OF RAIN TONIGHT AND SATURDAY ALONG AND BEHIND THE
COLD FRONT AS IT MOVES SLOWLY INTO THE FORECAST AREA.
BEST RAINFALL AMOUNTS OVER THE NEXT 4-DAY PERIOD ARE STILL
EXPECTED TO BE OVER THE NORTHWESTERN SET OF COUNTIES. MODEL PW/S
DO REACH A MAXIMUM OF 1.8 TO 2.0 INCHES ON SATURDAY...MAINLY OVER
THE NORTHWESTERN HALF OF THE FORECAST AREA. HOWEVER...MODEL
SOUNDING PROFILE FORECASTS ARE STILL NOT VERY CONDUCIVE FOR
THUNDERSTORM DEVELOPMENT. A MODEL CONSENSUS HAS A 4-DAY RAINFALL
TOTAL BY MIDDAY MONDAY RANGING FROM 1 TO 2 INCHES ALONG AND NORTH
OF A LINE FROM GROVETON TO HUNTSVILLE TO BRENHAM. LESS THAN ONE
HALF OF AN INCH IS FORECAST BY THE MODELS ALONG AND SOUTH OF A
LINE FROM LIBERTY TO HOUSTON TO BAY CITY.
LESSONING CHANCES OF RAIN IS EXPECTED ON MONDAY OVER MOST AREAS.
AN UPPER LEVEL LOW PRESSURE TROUGH IS THEN EXPECTED TO MOVE ACROSS
THE PLAINS BY THE MIDDLE OF NEXT WEEK. THIS SYSTEM WILL BRING
INCREASING CHANCES OF RAIN TUESDAY AND WEDNESDAY.
40
MARINE...
A COLD FRONT WILL APPROACH SE TX TONIGHT AND SATURDAY. THE FRONT MAY
PUSH OFF THE UPPER TX COAST LATER ON SUNDAY. UNTIL THEN FRESH TO
STRONG SE WINDS WILL CONTINUE WITH ROUGH SEAS OFFSHORE. ADVISORIES
AND CAUTIONS WILL CONTINUE THROUGH THE MORNING HOURS. WINDS SHOULD
BE DECREASING THIS AFTERNOON AND EXPECT SEAS TO DECREASE SOME. THERE
ARE SOME LONGER PERIOD SWELLS MIXED WITH WIND WAVES WHICH MAY KEEP
SEAS AT MODERATE TO ROUGH LEVELS. SEAS SHOULD DECREASE FURTHER
SUNDAY INTO MONDAY AS WINDS DECREASE AHEAD OF THE COLD FRONT. THE
FRONT SHOULD SHIFT WINDS TO THE NORTH MONDAY BUT SHOULD NOT BE VERY
STRONG. A STRONGER COLD FRONT MAY PUSH OFF THE COAST TUESDAY NIGHT
INTO WEDNESDAY. STRONG NORTHEAST WINDS MAY DEVELOP IN ITS WAKE LATER
ON WEDNESDAY.
SEA FOG...IT APPEARS THAT SEA FOG MAY NOT FORM SINCE WATER TEMPS
HAVE INCREASED AND MOISTURE LEVELS REMAIN JUST LOW ENOUGH THAT FOG
MAY NOT FORM.
COASTAL FLOOD POTENTIAL...TIDES AT EAGLE POINT AND GALVESTON NORTH
JETTY ARE ABOUT 1.5 TO 1.9 FEET ABOVE ASTRONOMICAL LEVELS THIS
MORNING. THIS IS LEADING TO TOTAL WATER LEVELS OF AROUND 3 FEET
ABOVE MLLW. HIGH TIDE AT GALVESTON NORTH JETTY THIS EVENING AROUND
6PM CST IS ABOUT 2 FEET ABOVE MLLW SO ADDING AN ADDITIONAL 1.5 FEET
WOULD YIELD WATER LEVELS AROUND 3.5 FEET ABOVE MLLW. ONCE AGAIN
THESE LEVELS WOULD CAUSE IMPACTS TO HIGHWAY 87 ALONG BOLIVAR
PENINSULA. A COASTAL FLOOD ADVISORY MAY BE NEEDED AGAIN SHOULD THESE
TIDE TRENDS CONTINUE INTO THE AFTERNOON.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 49 50 46 53 / 50 70 60 70 60
HOUSTON (IAH) 78 65 69 57 67 / 30 40 40 40 30
GALVESTON (GLS) 75 68 74 64 72 / 20 20 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...
WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS
FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
148 PM PST FRI NOV 27 2015
.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM CENTERED OVER THE GREAT BASIN...WILL
KEEP THE WEATHER VERY COOL OR DOWNRIGHT COLD THROUGH THE HOLIDAY
WEEKEND. SCATTERED SHOWERS WILL CONTINUE THROUGH EARLY EVENING
MAINLY FOR SAN DIEGO COUNTY...WITH SHOWERS TAPERING OFF TOWARDS LATE
EVENING. 1 TO 3 INCHES OF NEW SNOWFALL MAY OCCUR IN THE MOUNTAINS
AROUND 4500 FEET OR HIGHER...MAINLY IN THE SAN DIEGO AND RIVERSIDE
COUNTY MOUNTAINS. THE NIGHTS WILL BE VERY COLD THIS WEEKEND WITH
BELOW FREEZING TEMPERATURES LIKELY IN PORTIONS OF THE VALLEYS AND
DESERT AREAS. DRY AND WARMER NEXT WEEK AS LOW PRESSURE DRIFTS EAST
WITH WEAK OFFSHORE SURFACE FLOW.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
A STRONG VORT MAX IS CURRENTLY ROTATING AROUND THE GREAT BASIN
TROUGH AND SWOOPING DOWN THROUGH SOUTHERN CALIFORNIA...ACCORDING TO
WATER VAPOR SATELLITE. ALSO...ON VISIBLE SATELLITE A CIRCULATION IS
EVIDENT WHICH IS SLOWLY MAKING ITS WAY TOWARD THE SAN DIEGO COUNTY
COAST. ISOLATED TO SCATTERED SHOWERS ASSOCIATED WITH THE THESE
FEATURES ARE CONTINUING...MAINLY OVER SAN DIEGO COUNTY...ALTHOUGH
A POP-UP STATIONARY HEAVY SHOWER IN SOUTHERN ORANGE COUNTY PRODUCED
SOME PEA SIZE HAIL AND 0.38 INCHES OF RAIN IN 10 MINUTES. THERE ARE
ALSO SOME ISOLATED SHOWERS EVIDENT IN THE SOUTHERN INLAND EMPIRE
AND SOME LIGHT SNOW SHOWERS IN THE SAN BERNARDINO COUNTY MOUNTAINS.
RAINFALL AMOUNTS FROM MOST OF THE SHOWERS TODAY HAS BEEN MAINLY ON
THE ORDER OF 0.03-0.10 INCHES WITH LOCAL 0.20-0.30 INCH AMOUNTS
UNDER THE HEAVIER CELLS. TAKING A LOOK AT WEB-CAMS AND TEMPERATURES
IN THE MOUNTAINS...SNOW LEVELS ARE CURRENTLY AT AROUND 4500-5000
FEET. AS THE VORT MAX CONTINUES TO MOVE THROUGH THE REGION...LATEST
HRRR NOW SHOWS SCATTERED LIGHT TO MODERATE SHOWERS
CONTINUING...MAINLY OVER AND WEST OF THE SAN DIEGO COUNTY
MOUNTAINS...THROUGH EARLY EVENING...WITH SHOWERS GRADUALLY
DISSIPATING IN THE MID TO LATE EVENING. SNOW LEVELS CURRENTLY AT
4500-5000 FEET THIS AFTERNOON WILL LIKELY DROP TO 4000-4500 FEET
THIS EVENING...WITH ADDITIONAL SNOW ACCUMULATIONS OF 1-3 INCHES
POSSIBLE IN THE RIVERSIDE AND SAN DIEGO COUNTY MOUNTAINS...MAINLY
ABOVE 4500 FOOT ELEVATION. CONSIDERING WHAT THE HRRR SHOWS...HAVE
EXTENDED THE WINTER WEATHER ADVISORY THROUGH 7 PM FOR THE SAN DIEGO
AND RIVERSIDE COUNTY MOUNTAINS. ADDITIONAL PRECIPITATION AMOUNTS
OVER THE RIVERSIDE COUNTY MOUNTAINS AND OVER AND WEST OF THE SAN
DIEGO COUNTY MOUNTAINS LOOK TO BE GENERALLY ABOUT 0.05-0.20
INCHES...WITH A TRACE TO A TENTH OF AN INCH ELSEWHERE OVER AND WEST
OF THE MOUNTAINS. TEMPERATURES CURRENTLY ARE SEVERAL DEGREES LOWER
THAN AT THIS TIME YESTERDAY...AND DAY-TIME HIGHS WILL BE 10-20
DEGREES BELOW NORMAL.
SATURDAY AND SUNDAY...THE TROUGH WILL GRADUALLY MOVE OFF TO THE EAST
WITH MAINLY ZONAL FLOW ALOFT FOR MOST OF NEXT WEEK. MEANWHILE...WEAK
OFFSHORE FLOW KICKING IN TONIGHT THROUGH MOST OF NEXT WEEK WILL
BRING DRYING AND VERY GRADUAL WARMING THROUGH THAT PERIOD...WITH DAY-
TIME HIGHS REACHING BACK ABOVE NORMAL BY WEDNESDAY.
HOWEVER...OVERNIGHT LOWS THE NEXT FEW NIGHTS WILL BE BELOW FREEZING
FOR MANY INLAND VALLEY DUE TO THE LINGERING COLD AIR MASS...DRIER
AIR...LIGHT WINDS AND MOSTLY CLEAR SKIES. A FREEZE WARNING GOES INTO
EFFECT LATE TONIGHT FOR THE HIGH DESERTS AND CENTRAL/EASTERN INLAND
EMPIRE...WITH A FREEZE WATCH REMAINING IN EFFECT FOR OVERNIGHT
SATURDAY NIGHT. THE INLAND EMPIRE WAS A LITTLE BIT OF A QUESTION
MARK AS TO IF TEMPERATURES WOULD GET LOW ENOUGH FOR A FREEZE...BUT
LOCAL WRF SHOWS THAT THERE SHOULD BE ENOUGH DRYING...AND MOS
GUIDANCE SHOWS LOWS REACHING THE 29-32 DEGREE RANGE.
MEANWHILE...WITH LINGERING MOISTURE IN THE AREA...DOES NOT LOOK
LIKELY THAT THE SAN DIEGO COUNTY VALLEYS WILL REACH BELOW FREEZING
FOR LATE TONIGHT/SATURDAY MORNING...SO HAVE OPTED FOR A FROST
ADVISORY...ALTHOUGH FREEZE CONDITIONS LOOK MORE LIKELY FOR OVERNIGHT
SATURDAY NIGHT DUE TO INCREASED DRYING...SO THE FREEZE WATCH REMAINS
IN EFFECT FOR THAT TIME PERIOD. IN ADDITION...SOME OF THE COLDER
PORTIONS OF THE LOWER DESERTS MAY ALSO GET COLD ENOUGH...IN THE 33
TO 36 DEGREE RANGE...FOR FROST CONDITIONS...SO A FROST ADVISORY HAS
BEEN ISSUED FOR THOSE AREAS FOR OVERNIGHT TONIGHT. SIMILARLY COLD
CONDITIONS ARE LIKELY IN THESE AREAS OVERNIGHT SUNDAY NIGHT AS WELL.
BY OVERNIGHT MONDAY...TEMPERATURES MAY BE HIGH ENOUGH WHERE FROST
AND FREEZE WILL NO LONGER BE A CONCERN.
IN THE EXTENDED...ONSHORE FLOW LOOKS LIKE IT WILL RETURN
THURSDAY...WITH A TROUGH MOVING THROUGH SOUTHERN CALIFORNIA ON
FRIDAY. THE ECMWF SPITS OUT SOME PRECIPITATION WITH THIS
TROUGH...WHILE THE GFS IS MOSTLY DRY. A SLIGHT CHANCE OF SHOWERS HAS
BEEN ADDED FOR PORTIONS OF THE AREA FOR FRIDAY.
&&
.AVIATION...
272100Z...COAST/VALLEYS/MTNS...SCT/BKN CLOUDS...WITH BASES 4500 TO
6000 FT MSL AND TOPS NEAR 9000 FT MSL...WILL CONTINUE THROUGH THIS
AFTERNOON. SKIES THIS EVENING WILL BECOME SKC-SCT...WITH GREATEST
CLOUD COVERAGE NEAR THE MTNS. -SHRA WILL BE POSSIBLE THROUGH THIS
AFTERNOON...WITH GREATEST COVERAGE IN SAN DIEGO COUNTY. ABOVE 4000
FT MSL...SCATTERED SNOW SHOWERS AND CLOUDS INTERSECTING TERRAIN WILL
REDUCE SFC VIS TO LESS THAN 1 SM AT TIMES TODAY.
DESERTS...FEW-BKN AT OR ABOVE 10000 FT MSL WITH UNRESTRICTED VIS
THROUGH SAT MORNING.
&&
.MARINE...
100 PM...SCATTERED SHOWERS WILL CONTINUE THROUGH THIS AFTERNOON. NO
HAZARDOUS MARINE CONDITIONS ARE EXPECTED SATURDAY THROUGH WEDNESDAY.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING FOR
RIVERSIDE COUNTY MOUNTAINS-SAN DIEGO COUNTY MOUNTAINS.
FREEZE WARNING FROM 1 AM TO 8 AM PST SATURDAY FOR APPLE AND
LUCERNE VALLEYS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-
THE INLAND EMPIRE.
FROST ADVISORY FROM 1 AM TO 8 AM PST SATURDAY FOR COACHELLA
VALLEY-SAN DIEGO COUNTY DESERTS-SAN DIEGO COUNTY VALLEYS-
SAN GORGONIO PASS NEAR BANNING.
FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR
APPLE AND LUCERNE VALLEYS-SAN BERNARDINO AND RIVERSIDE
COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY VALLEYS.
PZ...NONE.
&&
$$
PUBLIC...HARRISON
AVIATION/MARINE/BEACHES...JJT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
321 PM MST FRI NOV 27 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 319 PM MST FRI NOV 27 2015
...SOME AREAS OF LIGHT SNOW TONIGHT...
...COLD BUT LESS SNOW TOMORROW...
THE MODELS ARE NOT DOING VERY WELL TODAY IN CAPTURING BL PROCESSES
AND THE CLOUD/PRECIP POTENTIAL ACROSS THE CWA. RELATIVELY SHALLOW
COLD AIR AND SERLY FLOW ACROSS EL PASO COUNTY HAS LEAD TO LIGHT SNOW
THROUGH TODAY...ALBEIT WITH LITTLE ACCUMULATION...WHILE THE REST OF
THE PLAINS HAVE STAYED GENERALLY PRECIP-FREE. MEANWHILE...THE SAN
LUIS VALLEY HAS SEEN A GOOD AMOUNT OF SUN...DESPITE DEEP SATURATED
LAYERS PROGGED BY THE MODELS. SO...THE SHORT TERM FORECAST IS A BIT
PROBLEMATIC AND PERSISTENCE WILL RULE FOR NOW.
TONIGHT...ANOTHER WAVE OF LIGHT SNOW SHOWERS IS LIKELY AS THE LOW
PRESSURE SYSTEM OVER NW AZ/SW UT EJECTS TO THE NE INTO WY BY SAT
AFTERNOON. BEST FORCING FROM THIS DISTURBANCE WILL BE THIS
EVENING...SO BEST CHANCE OF ADDITIONAL ACCUMULATING SN WILL BE FROM
NOW THROUGH ABOUT 06Z TONIGHT. MOST ACCUMS SHOULD BE ON THE LIGHT
SIDE...UNDER AN INCH. THE SAN JUANS WILL CONTINUE TO SEE STEADY
LIGHT TO MDT SNOW SO WILL CONTINUE THE ADVISORY FOR THAT AREA.
ANOTHER AREA THAT MIGHT SEE SOME RESPECTABLE ACCUMS IS THE ARKANSAS
RIVER CANYON ALONG WITH FREMONT COUNTY....THE NRN SANGRES...AND THE
WET MTN VALLEY. HIGH RES MODELS LIKE THE HRRR ARE SHOWING THE BEST
EVENING POTENTIAL IN THAT REGION...WITH SEVERAL INCHES OF SNOW
POSSIBLE BY SATURDAY MORNING. STILL PRETTY UNCERTAIN WHERE EXACTLY
THE HIGHEST ACCUMS WILL BE...OR WHETHER THIS HEAVIER BAND OF SNOW
DEVELOPS AT ALL...SO WILL KEEP HEADLINE-FREE FOR NOW. WILL HAVE TO
KEEP A CLOSE WATCH ON HOW THINGS DEVELOP THIS EVENING. IN
GENERAL...SUSPECT THE MODELS ARE OVERDOING PRECIP POTENTIAL THROUGH
SAT MORNING SO HAVE CUT BACK QPF ACCORDINGLY. HAVE ADDED SOME
AREAS OF PC FZDZ OVER THE ERN PLAINS INTO SAT MORNING...AS MODEL
SOUNDING INDICATE SOME POTENTIAL FOR ADDITIONAL LIGHT FZDZ IN THE
SHALLOW COLD AIR MASS.
SATURDAY...CONDITIONS SHOULD IMPROVE SOMEWHAT BUT IT WILL CONTINUE
TO BE COLD...WITH TEMPS ON THE PLAINS STRUGGLING TO HIT 30 DEGREES.
WARMEST SPOTS WILL BE THE MID ELEVATION AREAS CLOSE TO THE WETS AND
SRN SANGRES...DEPENDING ON HOW DEEP THE COLD AIR IS. THE SAN LUIS
VALLEY SHOULD ALSO GET ABOVE FREEZING FOR MUCH OF THE AFTERNOON. WILL
KEEP VERY LOW POPS IN FOR THE AREA TOMORROW AFTERNOON. THE GFS
CONTINUES TO SHOW SOME LIGHT QPF OVER SE CO...WHILE THE NAM IS
SHOWING DRY CONDITIONS. WITH THE UPPER LOW STILL TO OUR NW THERE
WILL STILL BE SOME MODEST FORCING AND MOISTURE FOR PRECIP...BUT
CHANCES FOR MEASURABLE PRECIP DO NOT LOOK VERY HIGH...AND THE MORE
LIKELY SCENARIO IS FOR SOME CLEARING BY SAT AFTERNOON. ROSE
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 319 PM MST FRI NOV 27 2015
SAT NIGHT THE UPR LOW IS EXPECTED TO BE AROUND THE EXTREME SWRN
CORNER OF WY. FORECAST MODELS ARE GENERALLY DRY...BUT DO SHOW THE
POTENTIAL FOR SOME LIGHT SNOW...BUT PORTIONS OF THE FAR SERN
PLAINS COULD SEE SOME PATCHY FZDZ AS WELL. MOST LOCATIONS SHOULD
SEE LOWS IN THE TEENS.
ON SUN THE UPR LOW CENTER IS FORECAST TO MOVE INTO CENTRAL WY. A
DISTURBANCE IN THE FLOW AROUND THE SRN SIDE OF THE LOW...IS EXPECTED
TO MOVE INTO WRN CO...ENHANCING SNOW CHANCES ALONG THE CONTDVD AND
MAYBE INTO THE TELLER COUNTY AND PIKES PEAK AREA IN THE AFTERNOON.
ACRS THE SERN PLAINS AND MTNS THERE WL CONTINUE TO BE THE POSSIBILITY
OF SOME LIGHT SNOW...WITH SOME PATCHY FZDZ STILL POSSIBLE IN AREAS
NEAR THE KS BORDER. HIGH TEMPS ON SUN ARE EXPECTED TO BE IN THE 30S
OVER MOST OF THE LOWER ELEVATION LOCATIONS.
SUN EVENING THE UPR TROF AND DISTURBANCE MOVE ACRS THE FORECAST
AREA...LIKELY BRINGING A BETTER CHANCE FOR SNOW TO THE EASTERN MTNS
AND PLAINS. AT THIS TIME ANY SNOW ACCUMULATIONS ARE EXPECTED TO BE
LIGHT. BY LATE NIGHT/EARLY MON MORNING THE DISTURBANCE IS EXPECTED
TO MOVE EAST OF THE AREA AND WITH THE PCPN LIFTING NORTHEASTWARD. THE
NAM IS A LITTLE FASTER ENDING THE PCPN FROM WEST TO EAST THAN THE
GFS.
ON MON THE UPR LOW IS EXPECTED TO MOVE INTO THE ERN HALF OF
NE...LEAVING W TO NW FLOW ALOFT OVR THE FORECAST AREA...ALONG WITH
DRIER CONDITIONS. MSTR IN THE NW FLOW WL LIKELY KEEP SOME LIGHT
SNOWFALL GOING OVER THE CENTRAL MTNS ON MON. HIGHS ON MON MAY GET
INTO THE LOWER 40S OVR SOME OF THE SERN PLAINS...BUT THE REST OF THE
LOWER ELEVATIONS SHOULD MAINLY BE IN THE 30S.
TUE THROUGH FRI DRY WX IS EXPECTED WITH HIGH TEMPS WARMING A LITTLE
EACH DAY...WITH HIGHS BY FRI BEING IN THE 50S OVR THE SERN PLAINS
AND IN THE 40S OVER THE HIGH VALLEY AREAS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 319 PM MST FRI NOV 27 2015
PERIODS OF LIGHT SHSN WILL CONTINUE TO BE POSSIBLE THROUGH ABOUT 06-
08Z TONIGHT...AS ANOTHER DISTURBANCE MOVES THROUGH NRN CO. MVFR TO
OCCASIONALLY IFR CONDITIONS WILL BE POSSIBLE WITH THE PRECIP. SOME
FG CAN NOT BE RULED OUT EARLY SAT MORNING...ESPECIALLY AT KALS...BUT
WILL KEEP KALS VFR FOR NOW. SOME MODEL GUIDANCE IS PREDICTING LOW
CIGS TO CONTINUE THROUGH SAT AFTERNOON AT KPUB AND ESPECIALLY
KCOS...BUT THE MORE LIKELY SCENARIO IS FOR VFR CONDITIONS AT LEAST
BY SAT AFTERNOON. WITH CONTINUED SERLY SFC WINDS...THERE IS STILL A
SIGNIFICANT POSSIBILITY THAT KCOS ESPECIALLY COULD REMAIN MVFR TO
IFR WITH LOW CIGS. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST SATURDAY FOR COZ067-068.
&&
$$
SHORT TERM...ROSE
LONG TERM...28
AVIATION...ROSE
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
255 PM CST FRI NOV 27 2015
.SHORT TERM...(Tonight)
ISSUED AT 250 PM CST FRI NOV 27 2015
The cold front draped across the eastern half of the country has
almost made it all the way through ILXs area this afternoon, and is
currently in the vicinity of I-70. Plenty of precipitation in the
region moving up from the SW. Precip is expected to continue,
particularly in the south and east through the overnight. The big
issues are the northern extent of the measurable precip, and the
timing of the cold air moving in behind it. HRRR and NAM both
trying to pull the precip further south after 06z, which should
remove the threat for FZRA later tonight. The forward progression
of the cooler air is also working against the rainfall as it is much
drier than the airmass over Central Illinois. The dry air is slowly
eroding the llvl RH and some of the weaker echos in the NW are only
seeing low clouds, and not reporting precip. Even in the NW where
the rain chances may recede after midnight, the low clouds and
potential for a misty night remain.
&&
.LONG TERM...(Saturday through Friday)
ISSUED AT 250 PM CST FRI NOV 27 2015
Our area should be in between shortwaves on Saturday with a definite
trend south with the axis of heavier QPF from previous forecasts.
With our area in between shortwave trofs on Saturday, it appears the
better chances for rain will be across southeast Illinois, closer to
the frontal boundary and any associated weak surface wave that will
track northeast along it. Forecast soundings not very supporting of
any precip further north during the day so we will see a gradual
shift south with the higher POPs as the boundary gets a nudge to the
south by afternoon. Forecast soundings showing some drier air (900-
800 mb)advecting south into the region during the day as well but
expect quite a bit of cloudiness to hang around during the day with
the lingering POPs mainly across the southern third of the forecast
area by afternoon.
Low POPs will remain Saturday night into Sunday with the GFS showing
a weak lead shortwave coming out of the large upper low over the
southwest U.S. Sunday afternoon and evening with the main push from
the low to our southwest not getting into central Illinois until
Monday. That is when we will see likely POPs return across the
entire area with forecast soundings continuing to support rain
during the day, and then as we see cold advection settle in around
the backside of the upper low Monday night, we will see a mix or
changeover to light snow before the main forcing/lift ejects off to
the northeast on Tuesday. The main 500 mb trof axis will not shift
off to our east until Wednesday, so we will continue with at
least some low chance POPs Tuesday and Tuesday night associated
with the cold pool aloft. Finally, by Wednesday, the system should
be far enough to our northeast to have a dry forecast for the
entire area along with seasonably cool temperatures.
As the large upper low continues to drift away from the Midwest late
Wednesday into the end of the work week, upper level heights will
start to increase across the region, with more of a semi-zonal flow
pattern depicted on medium range models. This should result in a
rather quiet weather scene over the region with near normal
temperatures and little if any rain or snow.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1133 AM CST FRI NOV 27 2015
Aviation forecast is dismal at best. Low cigs and bad visibility
is the rule, not the exception through the pd. PIA may lose the
majority of the precip, but still expecting MVFR cigs through the
overnight and mist. Rain, drizzle, low clouds with the front
stalling in the Ohio River Valley. Scattered nature of the heavier
showers putting some variability in the conditions, but
predominantly IFR, with some LIFR through the overnight. Northerly
winds will continue throughout, pretty brisk 10-15kts, some gusts
to 20.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...HJS
LONG TERM...Smith
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
332 PM EST FRI NOV 27 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 320 PM EST FRI NOV 27 2015
CHILLY...WET AND RAW CONDITIONS ARE EXPECTED THROUGH LATE SATURDAY
AS A COLD FRONT SLOWLY SLIPS SOUTH THROUGH THE REGION. AFTER A BRIEF
PERIOD OF DRY WEATHER SUNDAY...THE FRONT WILL RETURN NORTH INTO
CENTRAL INDIANA EARLY NEXT WEEK...USHERING IN MORE RAIN AND
UNSETTLED CONDITIONS. COOLER AND DRIER WEATHER IS THEN EXPECTED BY
MIDWEEK AS HIGH PRESSURE BUILDS ACROSS THE MIDWEST.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 320 PM EST FRI NOV 27 2015
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON WITH A COLD
FRONT SLOWLY SAGGING INTO NORTHERN COUNTIES. HAVE SEEN A 7 TO 10
DEGREE DROP WITHIN A SHORT PERIOD OF TIME IMMEDIATELY FOLLOWING THE
FRONTAL PASSAGE. AT 20Z...THE FRONT WAS ROUGHLY ALIGNED FROM JUST
NORTH OF KMIE W/SW THROUGH CENTRAL VERMILLION COUNTY. TEMPS WERE IN
THE 40S NORTH OF THE FRONT...WITH MID 50S TO LOWER 60S SOUTH OF THE
BOUNDARY.
THE RAIN AND TEMPERATURE SHIFT ARE THE PRIMARY ISSUES FOR THE NEAR
TERM AS THE FRONTAL BOUNDARY CONTINUES ITS SLOW SOUTHWARD TREK
THROUGH THE NIGHT. EXPECT THE FRONT TO PASS THE INDY METRO OVER THE
NEXT 3 HOURS OR SO...AND SHOULD CLEAR THE METRO AREA TO THE SOUTH
AROUND OR SHORTLY AFTER 00Z. THE DEVELOPMENT OF A SECONDARY SURFACE
WAVE ALONG THE FRONT WILL SLOW THE SOUTHWARD PUSH OF THE BOUNDARY
EVEN FURTHER OVERNIGHT...WITH THE FRONT LIKELY TO BE LOCATED
SOMEWHERE IN THE VICINITY OF THE THE FAR SOUTHERN COUNTIES BY
DAYBREAK SATURDAY.
THE LOW LEVEL JET WILL WEAKEN THROUGH THE EVENING AS THE FRONT
STRETCHES OUT. WHILE THE JET WEAKENS...DEEP ISENTROPIC LIFT WILL
CONTINUE OVERNIGHT AND BECOME FOCUSED OVER THE SOUTHERN HALF OF THE
FORECAST AREA IN CLOSE PROXIMITY TO THE SURFACE BOUNDARY.
ADDITIONALLY...FAVORABLE UPPER LEVEL DYNAMICS WILL PERSIST FOR MUCH
OF THE NIGHT WITH THE REGION REMAINING NEAR THE RIGHT REAR QUAD OF
THE DEPARTING UPPER JET OVER THE EASTERN GREAT LAKES. ALL THIS
POINTS TO CONTINUED RAIN OVERNIGHT WITH MOST WIDESPREAD AND HEAVIER
RATES SETTING UP ALONG AND SOUTH OF I-70. 100 POPS REMAINS VALID FOR
THE ENTIRE FORECAST AREA. WINDS WILL REMAIN AROUND 10-15 MPH
OVERNIGHT...SHIFTING TO A RAW AND CHILLY N/NE FLOW WITH THE FRONTAL
PASSAGE.
TEMPS...TOOK CURRENT OBS AND UTILIZED THE 18Z RAP AS A STARTING
POINT FOR HOURLY TEMP TRENDS OVER THE NEXT 6 TO 8 HOURS WITH THE
FRONT SLIDING SOUTH. LOWS WILL RANGE FROM THE UPPER 30S TO MID 40S
FROM NORTH TO SOUTH OVER MUCH OF THE AREA WHICH IS MUCH CLOSER TO
THE WARMER MAV GUIDANCE. DEPENDING ON WHERE THE FRONT LIES AT 12Z
SATURDAY WILL ULTIMATELY DETERMINE HOW COOL FAR SOUTHERN COUNTIES
GET. QUITE POSSIBLE THAT LOCALES FROM BEDFORD THROUGH SEYMOUR AND
NORTH VERNON HANG UP CLOSER TO 50.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 320 PM EST FRI NOV 27 2015
FORECAST CHALLENGES REMAIN FOCUSED PRIMARILY ON PRECIP CHANCES WITH
A PERSISTENT UNSETTLED WEATHER PATTERN FOR MUCH OF THE SHORT TERM
WITH A BRIEF BREAK WEDGED INTO THE MIDDLE OF THE PERIOD ON SUNDAY.
AFOREMENTIONED SECONDARY SURFACE WAVE WILL DRIFT SLOWLY ALONG THE
BOUNDARY THROUGH THE OHIO VALLEY SATURDAY...WITH RAIN CONTINUING
ACROSS MOST OF THE FORECAST AREA. ISENTROPIC LIFT AND LOW LEVEL
FORCING WILL BE STRONGEST OVER THE SOUTHERN HALF OF THE FORECAST
AREA WITH MOST WIDESPREAD RAIN EXPECTED HERE THROUGH THE DAY. THE
DEEPER LIFT AND MOISTURE WILL BEGIN TO SHIFT SOUTHEAST AS THE LOW
MOVES INTO THE CENTRAL APPALACHIANS SATURDAY EVENING...RESULTING IN
LIGHT SHOWERS ENDING FROM NORTHWEST TO SOUTHEAST OVER MOST OF THE
AREA SATURDAY NIGHT. MODEL SOUNDINGS AND RH PROGS SHOW LOW LEVEL
MOISTURE LINGERING WELL BEHIND THE PRECIP SHIELD WITH MOST AREAS
REMAINING CLOUDY INTO SUNDAY. SOME CLEARING IS POSSIBLE OVER FAR
NORTHERN COUNTIES TOWARDS DAYBREAK SUNDAY.
PERSISTENT SOUTHWEST FLOW ALOFT DRAWING PACIFIC MOISTURE INTO THE
REGION WILL BECOME ZONAL AND EVEN BRIEFLY RIDGE AS STRONG SURFACE
HIGH PRESSURE EXPANDS EAST ACROSS THE GREAT LAKES ON SUNDAY. THIS
WILL SERVE TO SHIFT DEEPER MOISTURE AND BULK OF THE RAINFALL SOUTH
INTO THE TENNESSEE AND LOWER OHIO VALLEYS LATE SATURDAY NIGHT
THROUGH SUNDAY AND GIVE MOST OF THE FORECAST AREA A RESPITE FROM THE
WET PATTERN. EXPECT SOME SUNSHINE FOR NORTHERN COUNTIES SUNDAY WITH
MOSTLY CLOUDY SKIES PERSISTING NEAR AND SOUTH OF I-70. CANNOT RULE
OUT A COUPLE LIGHT SHOWERS OVER SOUTHERN COUNTIES SUNDAY BUT MOST
SHOULD STAY DRY.
ELONGATED AND STRONG UPPER LOW OVER THE INTERMOUNTAIN WEST WILL
BEGIN TO EJECT OUT INTO THE CENTRAL PLAINS SUNDAY NIGHT AND
MONDAY...LEADING TO A RESUMPTION OF THE MOIST SOUTHWEST FLOW INTO
THE OHIO VALLEY AHEAD OF THE SYSTEM. SURFACE CYCLOGENESIS WILL
COMMENCE EARLY MONDAY IN RESPONSE TO THE EASTWARD MOVEMENT OF THE
UPPER LOW...DEEPENING QUICKLY AS IT PULLS NORTH INTO THE UPPER
MIDWEST MONDAY NIGHT. THIS WILL PROMPT THE FRONTAL BOUNDARY TO LIFT
BACK NORTH INTO THE REGION AS A WARM FRONT. TIMING DIFFERENCES IN
PLAY AT THIS POINT BETWEEN MODELS WITH THE ECMWF AND TO A LESSER
EXTENT THE OP GFS FASTER IN BRINGING PRECIP BACK NORTH LATE SUNDAY
NIGHT INTO MONDAY. WILL REINTRODUCE LOW POPS SUNDAY NIGHT OVER ALL
BUT FAR NORTHERN COUNTIES...WITH HIGHER POPS MONDAY AS STEADIER
RAINS ENCOMPASS THE FORECAST AREA AS THE WARM FRONT LIFTS NORTH.
TEMPS...A MOS BLEND OVERALL WORKED WELL FOR HIGHS THROUGH THE
PERIOD...WITH TEMPS PRIMARILY IN THE 40S SATURDAY AND SUNDAY...AND
UPPER 40S TO LOWER 50S MONDAY. LEANED CLOSER TO RAW MODEL TEMPS FOR
LOWS AS MAV AND MET GUIDANCE LOOKED TOO AGGRESSIVE AND FAR TOO COLD
WITH LOWS THROUGH THE PERIOD. LINGERING CLOUDS SHOULD KEEP MOST
AREAS ABOVE FREEZING BOTH SATURDAY AND SUNDAY NIGHTS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 230 PM EST FRI NOV 27 2015
A FRONTAL SYSTEM AND ASSOCIATED UPPER LEVEL LOW WILL MOVE THROUGH
THE GREAT LAKES REGION TO START THE LONG TERM...BRINGING RAIN
CHANCES TO THE AREA MONDAY NIGHT INTO TUESDAY. BY TUESDAY NIGHT
COOLER TEMPERATURES WILL MOVE IN BEHIND THE FRONT AND COULD SEE
CHANCES FOR LIGHT RAIN AND SNOW FOR TUESDAY NIGHT INTO WEDNESDAY
WITH THE UPPER LOW MOVING THROUGH TO THE NORTH. AFTER THAT HIGH
PRESSURE WILL BUILD OVER THE AREA BRINGING DRY WEATHER WITH IT.
HIGHS SHOULD BE IN THE LOW TO MID 40S WEDNESDAY AND WARM BY A
COUPLE DEGREES BY FRIDAY.
&&
.AVIATION /DISCUSSION FOR 272100Z KIND TAF UPDATE/...
ISSUED AT 332 PM EST FRI NOV 27 2015
SHOULD BEGIN TO SEE IFR CEILINGS BECOME MORE PREVALENT AT THE KIND
TERMINAL OVER THE NEXT FEW HOURS AS SURFACE FRONT APPROACHES. TIMING
OF FRONTAL PASSAGE/WIND SHIFT STILL LOOKS GOOD BASED ON SHORT TERM
MODEL GUIDANCE.
PREVIOUS DISCUSSION FOLLOWS.
CONDITIONS WILL CONTINUE TO DETERIORATE TO IFR OVER THE NEXT FEW
HOURS FROM WEST TO EAST. VISIBILITIES IN RAIN ARE MAINLY VFR TO
MVFR BUT CEILINGS ALREADY INTO KLAF AND JUST UPSTREAM OF KHUF ARE
IFR. FORECAST SOUNDINGS INDICATE THESE LOW CEILINGS WILL HANG
AROUND THROUGH THE REST OF THE PERIOD WHILE RAIN CHANCES WILL
DECREASE IN THE NORTH DURING THE OVERNIGHT. SREF PROBABILITIES ARE
NOT AS PESSIMISTIC BUT ALSO ARE NOT CAPTURING THE CURRENT
SITUATION VERY WELL. THE FRONT WILL SLOWLY SINK SOUTH OF THE SITES
THROUGH THE PERIOD BUT A SURFACE WAVE MOVING ALONG IT WILL KEEP IT
FROM PROGRESSING ANY FURTHER SOUTH THAN THE OHIO RIVER THROUGH THE
PERIOD WHICH WILL KEEP LOW CEILINGS HANGING AROUND THE ENTIRE
TIME. WINDS WILL BE NORTHERLY NORTH OF THE FRONT AND SOUTHERLY
COMPONENT TO THE SOUTH OF IT...BUT ALL SITES BUT KLAF COULD SEE
THEM BACKING AS THE SURFACE WAVE MOVES ALONG THE FRONT TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....CP
AVIATION...CP/JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
320 PM EST FRI NOV 27 2015
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW
&&
.SYNOPSIS...
ISSUED AT 320 PM EST FRI NOV 27 2015
CHILLY...WET AND RAW CONDITIONS ARE EXPECTED THROUGH LATE SATURDAY
AS A COLD FRONT SLOWLY SLIPS SOUTH THROUGH THE REGION. AFTER A BRIEF
PERIOD OF DRY WEATHER SUNDAY...THE FRONT WILL RETURN NORTH INTO
CENTRAL INDIANA EARLY NEXT WEEK...USHERING IN MORE RAIN AND
UNSETTLED CONDITIONS. COOLER AND DRIER WEATHER IS THEN EXPECTED BY
MIDWEEK AS HIGH PRESSURE BUILDS ACROSS THE MIDWEST.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 320 PM EST FRI NOV 27 2015
RAIN CONTINUES ACROSS THE FORECAST AREA THIS AFTERNOON WITH A COLD
FRONT SLOWLY SAGGING INTO NORTHERN COUNTIES. HAVE SEEN A 7 TO 10
DEGREE DROP WITHIN A SHORT PERIOD OF TIME IMMEDIATELY FOLLOWING THE
FRONTAL PASSAGE. AT 20Z...THE FRONT WAS ROUGHLY ALIGNED FROM JUST
NORTH OF KMIE W/SW THROUGH CENTRAL VERMILLION COUNTY. TEMPS WERE IN
THE 40S NORTH OF THE FRONT...WITH MID 50S TO LOWER 60S SOUTH OF THE
BOUNDARY.
THE RAIN AND TEMPERATURE SHIFT ARE THE PRIMARY ISSUES FOR THE NEAR
TERM AS THE FRONTAL BOUNDARY CONTINUES ITS SLOW SOUTHWARD TREK
THROUGH THE NIGHT. EXPECT THE FRONT TO PASS THE INDY METRO OVER THE
NEXT 3 HOURS OR SO...AND SHOULD CLEAR THE AREA TO THE SOUTH AROUND
OR SHORTLY AFTER 00Z. THE DEVELOPMENT OF A SECONDARY SURFACE WAVE
ALONG THE FRONT WILL SLOW THE SOUTHWARD PUSH OF THE BOUNDARY EVEN
FURTHER OVERNIGHT...WITH THE FRONT LIKELY TO BE LOCATED SOMEWHERE IN
THE VICINITY OF THE THE FAR SOUTHERN COUNTIES BY DAYBREAK SATURDAY.
THE LOW LEVEL JET WILL WEAKEN THROUGH THE EVENING AS THE FRONT
STRETCHES OUT. WHILE THE JET WEAKENS...DEEP ISENTROPIC LIFT WILL
CONTINUE OVERNIGHT AND BECOME FOCUSED OVER THE SOUTHERN HALF OF THE
FORECAST AREA IN CLOSE PROXIMITY TO THE SURFACE BOUNDARY.
ADDITIONALLY...FAVORABLE UPPER LEVEL DYNAMICS WILL PERSIST FOR MUCH
OF THE NIGHT WITH THE REGION REMAINING NEAR THE RIGHT REAR QUAD OF
THE DEPARTING UPPER JET OVER THE EASTERN GREAT LAKES. ALL THIS
POINTS TO CONTINUED RAIN OVERNIGHT WITH MOST WIDESPREAD AND HEAVIER
RATES SETTING UP ALONG AND SOUTH OF I-70. 100 POPS REMAINS VALID FOR
THE ENTIRE FORECAST AREA. WINDS WILL REMAIN AROUND 10-15 MPH
OVERNIGHT...SHIFTING TO A RAW AND CHILLY N/NE FLOW WITH THE FRONTAL
PASSAGE.
TEMPS...TOOK CURRENT OBS AND UTILIZED THE 18Z RAP AS A STARTING
POINT FOR HOURLY TEMP TRENDS OVER THE NEXT 6 TO 8 HOURS WITH THE
FRONT SLIDING SOUTH. LOWS WILL RANGE FROM THE UPPER 30S TO MID 40S
FROM NORTH TO SOUTH OVER MUCH OF THE AREA WHICH IS MUCH CLOSER TO
THE WARMER MAV GUIDANCE. DEPENDING ON WHERE THE FRONT LIES AT 12Z
SATURDAY WILL ULTIMATELY DETERMINE HOW COOL FAR SOUTHERN COUNTIES
GET. QUITE POSSIBLE THAT LOCALES FROM BEDFORD THROUGH SEYMOUR AND
NORTH VERNON HANG UP CLOSER TO 50.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 320 PM EST FRI NOV 27 2015
FORECAST CHALLENGES REMAIN FOCUSED PRIMARILY ON PRECIP CHANCES WITH
A PERSISTENT UNSETTLED WEATHER PATTERN FOR MUCH OF THE SHORT TERM
WITH A BRIEF BREAK WEDGED INTO THE MIDDLE OF THE PERIOD ON SUNDAY.
AFOREMENTIONED SECONDARY SURFACE WAVE WILL DRIFT SLOWLY ALONG THE
BOUNDARY THROUGH THE OHIO VALLEY SATURDAY...WITH RAIN CONTINUING
ACROSS MOST OF THE FORECAST AREA. ISENTROPIC LIFT AND LOW LEVEL
FORCING WILL BE STRONGEST OVER THE SOUTHERN HALF OF THE FORECAST
AREA WITH MOST WIDESPREAD RAIN EXPECTED HERE THROUGH THE DAY. THE
DEEPER LIFT AND MOISTURE WILL BEGIN TO SHIFT SOUTHEAST AS THE LOW
MOVES INTO THE CENTRAL APPALACHIANS SATURDAY EVENING...RESULTING IN
LIGHT SHOWERS ENDING FROM NORTHWEST TO SOUTHEAST OVER MOST OF THE
AREA SATURDAY NIGHT. MODEL SOUNDINGS AND RH PROGS SHOW LOW LEVEL
MOISTURE LINGERING WELL BEHIND THE PRECIP SHIELD WITH MOST AREAS
REMAINING CLOUDY INTO SUNDAY. SOME CLEARING IS POSSIBLE OVER FAR
NORTHERN COUNTIES TOWARDS DAYBREAK SUNDAY.
PERSISTENT SOUTHWEST FLOW ALOFT DRAWING PACIFIC MOISTURE INTO THE
REGION WILL BECOME ZONAL AND EVEN BRIEFLY RIDGE AS STRONG SURFACE
HIGH PRESSURE EXPANDS EAST ACROSS THE GREAT LAKES ON SUNDAY. THIS
WILL SERVE TO SHIFT DEEPER MOISTURE AND BULK OF THE RAINFALL SOUTH
INTO THE TENNESSEE AND LOWER OHIO VALLEYS LATE SATURDAY NIGHT
THROUGH SUNDAY AND GIVE MOST OF THE FORECAST AREA A RESPITE FROM THE
WET PATTERN. EXPECT SOME SUNSHINE FOR NORTHERN COUNTIES SUNDAY WITH
MOSTLY CLOUDY SKIES PERSISTING NEAR AND SOUTH OF I-70. CANNOT RULE
OUT A COUPLE LIGHT SHOWERS OVER SOUTHERN COUNTIES SUNDAY BUT MOST
SHOULD STAY DRY.
ELONGATED AND STRONG UPPER LOW OVER THE INTERMOUNTAIN WEST WILL
BEGIN TO EJECT OUT INTO THE CENTRAL PLAINS SUNDAY NIGHT AND
MONDAY...LEADING TO A RESUMPTION OF THE MOIST SOUTHWEST FLOW INTO
THE OHIO VALLEY AHEAD OF THE SYSTEM. SURFACE CYCLOGENESIS WILL
COMMENCE EARLY MONDAY IN RESPONSE TO THE EASTWARD MOVEMENT OF THE
UPPER LOW...DEEPENING QUICKLY AS IT PULLS NORTH INTO THE UPPER
MIDWEST MONDAY NIGHT. THIS WILL PROMPT THE FRONTAL BOUNDARY TO LIFT
BACK NORTH INTO THE REGION AS A WARM FRONT. TIMING DIFFERENCES IN
PLAY AT THIS POINT BETWEEN MODELS WITH THE ECMWF AND TO A LESSER
EXTENT THE OP GFS FASTER IN BRINGING PRECIP BACK NORTH LATE SUNDAY
NIGHT INTO MONDAY. WILL REINTRODUCE LOW POPS SUNDAY NIGHT OVER ALL
BUT FAR NORTHERN COUNTIES...WITH HIGHER POPS MONDAY AS STEADIER
RAINS ENCOMPASS THE FORECAST AREA AS THE WARM FRONT LIFTS NORTH.
TEMPS...A MOS BLEND OVERALL WORKED WELL FOR HIGHS THROUGH THE
PERIOD...WITH TEMPS PRIMARILY IN THE 40S SATURDAY AND SUNDAY...AND
UPPER 40S TO LOWER 50S MONDAY. LEANED CLOSER TO RAW MODEL TEMPS FOR
LOWS AS MAV AND MET GUIDANCE LOOKED TOO AGGRESSIVE AND FAR TOO COLD
WITH LOWS THROUGH THE PERIOD. LINGERING CLOUDS SHOULD KEEP MOST
AREAS ABOVE FREEZING BOTH SATURDAY AND SUNDAY NIGHTS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 230 PM EST FRI NOV 27 2015
A FRONTAL SYSTEM AND ASSOCIATED UPPER LEVEL LOW WILL MOVE THROUGH
THE GREAT LAKES REGION TO START THE LONG TERM...BRINGING RAIN
CHANCES TO THE AREA MONDAY NIGHT INTO TUESDAY. BY TUESDAY NIGHT
COOLER TEMPERATURES WILL MOVE IN BEHIND THE FRONT AND COULD SEE
CHANCES FOR LIGHT RAIN AND SNOW FOR TUESDAY NIGHT INTO WEDNESDAY
WITH THE UPPER LOW MOVING THROUGH TO THE NORTH. AFTER THAT HIGH
PRESSURE WILL BUILD OVER THE AREA BRINGING DRY WEATHER WITH IT.
HIGHS SHOULD BE IN THE LOW TO MID 40S WEDNESDAY AND WARM BY A
COUPLE DEGREES BY FRIDAY.
&&
.AVIATION /DISCUSSION FOR 271800Z TAF ISSUANCE/...
ISSUED AT 1145 AM EST FRI NOV 27 2015
CONDITIONS WILL CONTINUE TO DETERIORATE TO IFR OVER THE NEXT FEW
HOURS FROM WEST TO EAST. VISIBILITIES IN RAIN ARE MAINLY VFR TO
MVFR BUT CEILINGS ALREADY INTO KLAF AND JUST UPSTREAM OF KHUF ARE
IFR. FORECAST SOUNDINGS INDICATE THESE LOW CEILINGS WILL HANG
AROUND THROUGH THE REST OF THE PERIOD WHILE RAIN CHANCES WILL
DECREASE IN THE NORTH DURING THE OVERNIGHT. SREF PROBABILITIES ARE
NOT AS PESSIMISTIC BUT ALSO ARE NOT CAPTURING THE CURRENT
SITUATION VERY WELL. THE FRONT WILL SLOWLY SINK SOUTH OF THE SITES
THROUGH THE PERIOD BUT A SURFACE WAVE MOVING ALONG IT WILL KEEP IT
FROM PROGRESSING ANY FURTHER SOUTH THAN THE OHIO RIVER THROUGH THE
PERIOD WHICH WILL KEEP LOW CEILINGS HANGING AROUND THE ENTIRE
TIME. WINDS WILL BE NORTHERLY NORTH OF THE FRONT AND SOUTHERLY
COMPONENT TO THE SOUTH OF IT...BUT ALL SITES BUT KLAF COULD SEE
THEM BACKING AS THE SURFACE WAVE MOVES ALONG THE FRONT TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....CP
AVIATION...CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
236 PM EST FRI NOV 27 2015
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 239 AM EST FRI NOV 27 2015
A FRONT WILL PASS INDIANA FROM THE NORTHWEST LATER TODAY...THEN
STALL A LITTLE TO THE SOUTH OF OUR STATE. FROM TONIGHT INTO MONDAY
THE HOOSIER STATE WILL STAY WEDGED BETWEEN THE FRONT AND HIGH
PRESSURE TO OUR NORTH.
TUESDAY AND WEDNESDAY LOW PRESSURE AND AN ASSOCIATED COLD FRONT ARE
PREDICTED TO SLOWLY CROSS INDIANA FROM THE WEST. A HIGH PRESSURE
SYSTEM SHOULD ARRIVE THURSDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1002 AM EST FRI NOV 27 2015
RAIN CONTINUES TO STEADILY OVERSPREAD THE FORECAST AREA AS OF MID
MORNING WITH THE FRONTAL BOUNDARY SLOWLY SAGGING TOWARDS THE
REGION. THE NORTHWEST HALF OF THE FORECAST AREA IS SEEING RAIN
WITH MAINLY DRY CONDITIONS SO FAR TO THE SOUTHEAST. TEMPS WERE
GENERALLY IN THE MID AND UPPER 50S AS OF 15Z.
RAIN...RAIN AND MORE RAIN FOR CENTRAL INDIANA TODAY AND TONIGHT AS
THE AFOREMENTIONED COLD FRONT SAGS INTO THE FORECAST AREA THROUGH
THE AFTERNOON. PRIMARY ISSUES FOR THE MORNING UPDATE IS TO OFFER
BIT MORE DETAIL TO RAINFALL ONSET OVER SOUTHEAST HALF OF FORECAST
AREA AND MAYBE MORE IMPORTANTLY...THE TEMPERATURE FALLS LATER
TODAY AS THE FRONT MOVES INTO CENTRAL INDIANA.
HAVE 100 POPS GOING WHERE IT IS RAINING NOW...BUT HAVE SCALED BACK
POPS QUITE A BIT OVER SOUTHEAST COUNTIES AT LEAST INITIALLY TO
ACCOUNT FOR CURRENT OBS. HRRR/WRF ANALYSIS SHOWING A STEADY
EXPANSION TO THE PRECIP SHIELD OVER THE NEXT SEVERAL HOURS WITH
THE ENTIRE FORECAST AREA IMPACTED BY THE SECOND HALF OF THE
AFTERNOON. WILL HAVE 100 POPS OVER ALL OF CENTRAL INDIANA BY LATE
DAY.
OTHER ISSUE FOCUSES ON TEMPS. HAVE SEEN A QUICK 8-10 DEGREE DROP
WITH THE FRONTAL PASSAGE AT SITES OVER NORTHWEST INDIANA AND
NORTHERN ILLINOIS...AND EXPECT A SIMILAR IMPACT AS THE BOUNDARY
PASSES LATER TODAY. MANY LOCATIONS ARE ALREADY AT THEIR HIGHS FOR
THE DAY WITH JUST SOUTHERN COUNTIES LIKELY TO SEE A FEW DEGREE
CLIMB OVER THE NEXT FEW HOURS BEFORE THE RAIN SETTLES IN. UTILIZED
THE RAP HOURLY GUIDANCE AS A BASE FOR TEMPS THE REST OF THE DAY
WITH SOME ADDITIONAL TWEAKS BASED ON CURRENT OBS. COULD EASILY SEE
A 15 TO 20 DEGREE SPREAD IN TEMPS FROM NORTH TO SOUTH BY SUNDOWN
WITH LOWER 40S OVER THE NORTHERN WABASH VALLEY ALONG WITH A RAW
NORTHERLY WIND. COLDER AND RAINY CONDITIONS WILL CONTINUE TONIGHT.
BUNDLE UP AND BE PREPARED FOR COLDER TEMPS BY LATE AFTERNOON AND
EARLY EVENING. ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
ISSUED AT 239 AM EST FRI NOV 27 2015
THE MAIN PROBLEM IS RAIN CHANCES AS A FRONT LINGERS IN THE AREA.
GIVEN WHERE IT HAS THE LOW...THE NAM QPF FIELDS LOOKS STRANGELY DRY
AT 12Z TOMORROW. THE GFS IS MORE CONSISTENT AND THE HIGHER MAV POPS
ARE PROBABLY BEST.
THE REAL UNCERTAINTY ARRIVES SATURDAY NIGHT. THE MODELS HAVE CHANGED
A LOT WITH EVERY RUN LATELY. GIVEN PROBLEMS COMING TO A CONSISTENT
SOLUTION...AN AN ENSEMBLE EFFECT MAY BE BEST AND SO A MAV MET
CONSENSUS WILL BE USED.
THERE IS SIGNIFICANT DIFFERENCE IN LOWS IN THE NORTHERN COUNTIES
SATURDAY NIGHT WITH THE MAV COOLER. THIS APPARENTLY REFLECTS
DIFFERENT HANDLING BY THE PARENT MODELS OF COOLER DRIER AIR TRYING
TO INFILTRATE. THAT FAR OUT ITS HARD TO BE SURE WHICH IS RIGHT AND
A CONSENSUS SHOULD BE THE MOST SKILLFUL FORECAST FOR NOW.
EXCEPT AS MENTIONED IN THE PREVIOUS PARAGRAPH STATISTICAL GUIDANCE
IS CLOSE FOR THE PERIOD AND CAN BE USED WITH REASONABLE CONFIDENCE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 230 PM EST FRI NOV 27 2015
A FRONTAL SYSTEM AND ASSOCIATED UPPER LEVEL LOW WILL MOVE THROUGH
THE GREAT LAKES REGION TO START THE LONG TERM...BRINGING RAIN
CHANCES TO THE AREA MONDAY NIGHT INTO TUESDAY. BY TUESDAY NIGHT
COOLER TEMPERATURES WILL MOVE IN BEHIND THE FRONT AND COULD SEE
CHANCES FOR LIGHT RAIN AND SNOW FOR TUESDAY NIGHT INTO WEDNESDAY
WITH THE UPPER LOW MOVING THROUGH TO THE NORTH. AFTER THAT HIGH
PRESSURE WILL BUILD OVER THE AREA BRINGING DRY WEATHER WITH IT.
HIGHS SHOULD BE IN THE LOW TO MID 40S WEDNESDAY AND WARM BY A
COUPLE DEGREES BY FRIDAY.
&&
.AVIATION /DISCUSSION FOR 271800Z TAF ISSUANCE/...
ISSUED AT 1145 AM EST FRI NOV 27 2015
CONDITIONS WILL CONTINUE TO DETERIORATE TO IFR OVER THE NEXT FEW
HOURS FROM WEST TO EAST. VISIBILITIES IN RAIN ARE MAINLY VFR TO
MVFR BUT CEILINGS ALREADY INTO KLAF AND JUST UPSTREAM OF KHUF ARE
IFR. FORECAST SOUNDINGS INDICATE THESE LOW CEILINGS WILL HANG
AROUND THROUGH THE REST OF THE PERIOD WHILE RAIN CHANCES WILL
DECREASE IN THE NORTH DURING THE OVERNIGHT. SREF PROBABILITIES ARE
NOT AS PESSIMISTIC BUT ALSO ARE NOT CAPTURING THE CURRENT
SITUATION VERY WELL. THE FRONT WILL SLOWLY SINK SOUTH OF THE SITES
THROUGH THE PERIOD BUT A SURFACE WAVE MOVING ALONG IT WILL KEEP IT
FROM PROGRESSING ANY FURTHER SOUTH THAN THE OHIO RIVER THROUGH THE
PERIOD WHICH WILL KEEP LOW CEILINGS HANGING AROUND THE ENTIRE
TIME. WINDS WILL BE NORTHERLY NORTH OF THE FRONT AND SOUTHERLY
COMPONENT TO THE SOUTH OF IT...BUT ALL SITES BUT KLAF COULD SEE
THEM BACKING AS THE SURFACE WAVE MOVES ALONG THE FRONT TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...RYAN
SHORT TERM...JK
LONG TERM....CP
AVIATION...CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1200 PM EST FRI NOV 27 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 239 AM EST FRI NOV 27 2015
A FRONT WILL PASS INDIANA FROM THE NORTHWEST LATER TODAY...THEN
STALL A LITTLE TO THE SOUTH OF OUR STATE. FROM TONIGHT INTO MONDAY
THE HOOSIER STATE WILL STAY WEDGED BETWEEN THE FRONT AND HIGH
PRESSURE TO OUR NORTH.
TUESDAY AND WEDNESDAY LOW PRESSURE AND AN ASSOCIATED COLD FRONT ARE
PREDICTED TO SLOWLY CROSS INDIANA FROM THE WEST. A HIGH PRESSURE
SYSTEM SHOULD ARRIVE THURSDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1002 AM EST FRI NOV 27 2015
RAIN CONTINUES TO STEADILY OVERSPREAD THE FORECAST AREA AS OF MID
MORNING WITH THE FRONTAL BOUNDARY SLOWLY SAGGING TOWARDS THE
REGION. THE NORTHWEST HALF OF THE FORECAST AREA IS SEEING RAIN
WITH MAINLY DRY CONDITIONS SO FAR TO THE SOUTHEAST. TEMPS WERE
GENERALLY IN THE MID AND UPPER 50S AS OF 15Z.
RAIN...RAIN AND MORE RAIN FOR CENTRAL INDIANA TODAY AND TONIGHT AS
THE AFOREMENTIONED COLD FRONT SAGS INTO THE FORECAST AREA THROUGH
THE AFTERNOON. PRIMARY ISSUES FOR THE MORNING UPDATE IS TO OFFER
BIT MORE DETAIL TO RAINFALL ONSET OVER SOUTHEAST HALF OF FORECAST
AREA AND MAYBE MORE IMPORTANTLY...THE TEMPERATURE FALLS LATER
TODAY AS THE FRONT MOVES INTO CENTRAL INDIANA.
HAVE 100 POPS GOING WHERE IT IS RAINING NOW...BUT HAVE SCALED BACK
POPS QUITE A BIT OVER SOUTHEAST COUNTIES AT LEAST INITIALLY TO
ACCOUNT FOR CURRENT OBS. HRRR/WRF ANALYSIS SHOWING A STEADY
EXPANSION TO THE PRECIP SHIELD OVER THE NEXT SEVERAL HOURS WITH
THE ENTIRE FORECAST AREA IMPACTED BY THE SECOND HALF OF THE
AFTERNOON. WILL HAVE 100 POPS OVER ALL OF CENTRAL INDIANA BY LATE
DAY.
OTHER ISSUE FOCUSES ON TEMPS. HAVE SEEN A QUICK 8-10 DEGREE DROP
WITH THE FRONTAL PASSAGE AT SITES OVER NORTHWEST INDIANA AND
NORTHERN ILLINOIS...AND EXPECT A SIMILAR IMPACT AS THE BOUNDARY
PASSES LATER TODAY. MANY LOCATIONS ARE ALREADY AT THEIR HIGHS FOR
THE DAY WITH JUST SOUTHERN COUNTIES LIKELY TO SEE A FEW DEGREE
CLIMB OVER THE NEXT FEW HOURS BEFORE THE RAIN SETTLES IN. UTILIZED
THE RAP HOURLY GUIDANCE AS A BASE FOR TEMPS THE REST OF THE DAY
WITH SOME ADDITIONAL TWEAKS BASED ON CURRENT OBS. COULD EASILY SEE
A 15 TO 20 DEGREE SPREAD IN TEMPS FROM NORTH TO SOUTH BY SUNDOWN
WITH LOWER 40S OVER THE NORTHERN WABASH VALLEY ALONG WITH A RAW
NORTHERLY WIND. COLDER AND RAINY CONDITIONS WILL CONTINUE TONIGHT.
BUNDLE UP AND BE PREPARED FOR COLDER TEMPS BY LATE AFTERNOON AND
EARLY EVENING. ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
ISSUED AT 239 AM EST FRI NOV 27 2015
THE MAIN PROBLEM IS RAIN CHANCES AS A FRONT LINGERS IN THE AREA.
GIVEN WHERE IT HAS THE LOW...THE NAM QPF FIELDS LOOKS STRANGELY DRY
AT 12Z TOMORROW. THE GFS IS MORE CONSISTENT AND THE HIGHER MAV POPS
ARE PROBABLY BEST.
THE REAL UNCERTAINTY ARRIVES SATURDAY NIGHT. THE MODELS HAVE CHANGED
A LOT WITH EVERY RUN LATELY. GIVEN PROBLEMS COMING TO A CONSISTENT
SOLUTION...AN AN ENSEMBLE EFFECT MAY BE BEST AND SO A MAV MET
CONSENSUS WILL BE USED.
THERE IS SIGNIFICANT DIFFERENCE IN LOWS IN THE NORTHERN COUNTIES
SATURDAY NIGHT WITH THE MAV COOLER. THIS APPARENTLY REFLECTS
DIFFERENT HANDLING BY THE PARENT MODELS OF COOLER DRIER AIR TRYING
TO INFILTRATE. THAT FAR OUT ITS HARD TO BE SURE WHICH IS RIGHT AND
A CONSENSUS SHOULD BE THE MOST SKILLFUL FORECAST FOR NOW.
EXCEPT AS MENTIONED IN THE PREVIOUS PARAGRAPH STATISTICAL GUIDANCE
IS CLOSE FOR THE PERIOD AND CAN BE USED WITH REASONABLE CONFIDENCE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY NIGHT/...
ISSUED AT 244 AM EST FRI NOV 27 2015
THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE RAIN CHANCES IN
ASSOCIATION WITH A POTENT LOW PRESSURE SYSTEM. AN UPPER LOW WILL
ENTER THE CENTRAL PLAINS ON MONDAY WITH A SURFACE LOW JUST OUT
AHEAD OF IT. LATEST SUPERBLEND INITIALIZATION SEEMS TO BE
HANDLING THIS SYSTEM WELL...HIGHLIGHTING HIGHEST RAIN CHANCES ON
MONDAY AND MONDAY NIGHT WITH PASSAGE OF COLD FRONT. SO...WILL NOT
DEVIATE FROM THE LIKELY POPS DURING THAT TIME FRAME. PRECIPITATION
IS STILL EXPECTED TO BE IN THE FORM OF RAIN FOR THE MAJORITY OF
THE EVENT...BUT THERE COULD BE A RAIN/SNOW MIXTURE TUESDAY
NIGHT/WEDNESDAY MORNING ACROSS THE NORTHERN COUNTIES WHEN COLDER
AIR FILTERS INTO CENTRAL INDIANA ON BACK SIDE OF AFOREMENTIONED
COLD FRONT. HIGH PRESSURE WILL RETURN ON WEDNESDAY...RESULTING IN
DRY CONDITIONS THROUGH THE REMAINDER OF THE EXTENDED PERIOD.
&&
.AVIATION /DISCUSSION FOR 271800Z TAF ISSUANCE/...
ISSUED AT 1145 AM EST FRI NOV 27 2015
CONDITIONS WILL CONTINUE TO DETERIORATE TO IFR OVER THE NEXT FEW
HOURS FROM WEST TO EAST. VISIBILITIES IN RAIN ARE MAINLY VFR TO
MVFR BUT CEILINGS ALREADY INTO KLAF AND JUST UPSTREAM OF KHUF ARE
IFR. FORECAST SOUNDINGS INDICATE THESE LOW CEILINGS WILL HANG
AROUND THROUGH THE REST OF THE PERIOD WHILE RAIN CHANCES WILL
DECREASE IN THE NORTH DURING THE OVERNIGHT. SREF PROBABILITIES ARE
NOT AS PESSIMISTIC BUT ALSO ARE NOT CAPTURING THE CURRENT
SITUATION VERY WELL. THE FRONT WILL SLOWLY SINK SOUTH OF THE SITES
THROUGH THE PERIOD BUT A SURFACE WAVE MOVING ALONG IT WILL KEEP IT
FROM PROGRESSING ANY FURTHER SOUTH THAN THE OHIO RIVER THROUGH THE
PERIOD WHICH WILL KEEP LOW CEILINGS HANGING AROUND THE ENTIRE
TIME. WINDS WILL BE NORTHERLY NORTH OF THE FRONT AND SOUTHERLY
COMPONENT TO THE SOUTH OF IT...BUT ALL SITES BUT KLAF COULD SEE
THEM BACKING AS THE SURFACE WAVE MOVES ALONG THE FRONT TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...RYAN
SHORT TERM...JK
LONG TERM....TDUD
AVIATION...CP
AREA FORECAST DISCUSSION
NWS GOODLAND KS
207 PM MST FRI NOV 27 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 207 PM MST FRI NOV 27 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SNOW LARGE
CLOSED LOW STILL IN PLACE ACROSS THE GREAT BASIN WITH EXTENSIVE
PLUME OF PACIFIC MOISTURE ACROSS THE SOUTHERN PLAINS...CENTRAL
MISSISSIPPI VALLEY AND NORTHEAST US. DRY LAYER (APPARENT ON
SATELLITE) IS STILL INFLUENCE OUR CWA AND WILL CONTINUE TO
COMPLICATE PRECIP TYPE THROUGH SATURDAY NIGHT.
THIS AFTERNOON-SATURDAY...STAGNANT/COLD PATTERN PERSISTS THROUGH
THESE PERIODS WITH POST FRONTAL/COLD AIR MASS LINGERING IN PLACE.
WEAK FRONTOGENETIC FORCING AND ISENTROPIC UPGLIDE REMAIN IN
PLACE. THE BIGGEST QUESTION REGARDING PRECIP CHANCES/TYPE IS THE
DEPTH/NATURE OF THE MOISTURE PROFILE OVER OUR CWA. A DRY LAYER IN
THE LOWEST 6000 KFT OF THE ATMOSPHERE DEVELOPED OVER NEBRASKA THIS
MORNING AND ADVECTED SOUTH ACROSS OUR CWA PUTTING AN END TO
PRECIP. THERE IS AN INDICATION OF RETURN FLOW/UPSLOPE FLOW
DEVELOPING LATE TONIGHT WITH INCREASING MOISTURE IN THE -3 TO -8C
LAYER SUPPORTIVE OF VERY LIGHT FREEZING RAIN OR FREEZING DRIZZLE.
THE QUESTION IS WHETHER THIS FLOW ACTUALLY DEVELOPS AS NORTHERLY
WINDS (INDICATED BY MOST GUIDANCE) SHOULD KEEP A PERSISTENT DRY
LAYER IN PLACE LIMITING POTENTIAL OR AT THE VERY LEAST COVERAGE.
GFS APPEARS TO BE THE MOST AGGRESSIVE ON SHIFTING BL FLOW TO THE
SOUTHEAST. A COMPLICATED PRECIP TYPE FORECAST BECOMES EVEN MORE
UNCERTAIN IF THE RETURN FLOW DOESN`T OCCUR AND MODEL SOUNDINGS END
UP OVERDONE. AFTER COLLABORATION...DECISION WAS MADE TO HOLD OFF
ON ADVISORY FOR TONIGHT AND SATURDAY AND I PLAN ON HANDLING THE
POTENTIAL WITH SPS FOR NOW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 207 PM MST FRI NOV 27 2015
SOUTHWEST FLOW WILL CONTINUE OVER THE CENTRAL PLAINS THROUGH SUNDAY
NIGHT AS AN UPPER LOW MOVES FROM NORTHERN UTAH INTO SOUTHWEST
WYOMING SUNDAY. THE LOW WILL THEN MOVE EAST INTO SOUTHEAST WYOMING
SUNDAY NIGHT AND INTO SOUTHWEST NEBRASKA MONDAY. SURFACE HIGH
PRESSURE WILL CONTINUE OVER THE CENTRAL PLAINS THROUGH SUNDAY. A
TROUGH WILL MOVE INTO EASTERN COLORADO SUNDAY NIGHT AND THEN MOVE
INTO CENTRAL KANSAS MONDAY AFTERNOON.
PLAN TO GO WITH LOW POPS SATURDAY NIGHT SINCE FORCING AND MID LEVEL
MOISTURE IS NOT THAT IMPRESSIVE. LOWER LEVEL MOISTURE IS
DECREASING AS WELL. FORECAST SOUNDINGS INDICATE THE POSSIBILITY OF
SOME LIGHT FREEZING DRIZZLE ALONG WITH SOME LIGHT SNOW OR
FLURRIES. LOW AND MID LEVEL MOISTURE INCREASE SUNDAY. FORCING
INCREASES SUNDAY AFTERNOON AND GOES INTO THE NIGHT. PLAN TO GO
WITH HIGHER CHANCE AND LIKELY POPS FOR THOSE PERIODS. LIGHT
FREEZING DRIZZLE SHOULD TAPER OFF BY EVENING AS MID LEVELS
SATURATE AND ICE FORMS IN THE COLUMN. OVERNIGHT MID LEVEL MOISTURE
STARTS DECREASING AGAIN SO WILL INTRODUCE SOME LIGHT FREEZING
DRIZZLE ALONG WITH THE LIGHT SNOW. TOTAL SNOW ACCUMULATIONS FROM
SUNDAY AFTERNOON THROUGH MONDAY SHOULD RANGE FROM 1 TO 3 INCHES
WITH THE HEAVIER AMOUNTS OVER THE NORTHEAST HALF OF THE FA.
MIN TEMPERATURES SHOULD COOL TO THE MID TO UPPER TEENS SATURDAY
NIGHT AND THE LOWER 20S SUNDAY NIGHT. MAX TEMPERATURES SHOULD
REACH THE LOWER 30S SUNDAY AND THE MID 30S MONDAY.
IN THE EXTENDED...(MONDAY NIGHT THROUGH FRIDAY)...
THE UPPER LOW WILL MOVE INTO EASTERN NEBRASKA MONDAY NIGHT WITH
NORTHWEST FLOW TUESDAY. A RIDGE WILL START BUILDING INTO THE
ROCKIES AND PLAINS WEDNESDAY AND WILL CONTINUE OVER THE PLAINS
FRIDAY. A SHORTWAVE WILL DIVE SOUTH THROUGH THE RIDGE
WEDNESDAY/WEDNESDAY NIGHT. HOWEVER MOISTURE AND FORCING IS LACKING
WITH THIS FEATURE SO NO PRECIPITATION IS EXPECTED. SUBSIDENCE IS
EVIDENT ACROSS THE FA FROM MONDAY NIGHT THROUGH FRIDAY AS THE
UPPER LOW EXITS AND THE RIDGE BUILDS IN BEHIND IT. CONSEQUENTLY,
POPS WILL BE NIL.
MIN TEMPERATURES WILL VARY FROM THE MID TO UPPER TEENS MODERATING TO
THE LOWER 20S THURSDAY AND FRIDAY NIGHTS. MAX TEMPERATURES SHOULD BE
UPPER 30S AND LOWER 40S TUESDAY AND WEDNESDAY MODERATING TO THE MID
AND UPPER 40S THURSDAY AND FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1040 AM MST FRI NOV 27 2015
A DRY LAYER BELOW 6000 KFT AGL HAS MOVED OVER BOTH KGLD AND KMCK
AND ALLOWED CONDITIONS TO IMPROVE TO VFR. MODELS SHOW THE LOWER
LEVELS BEGINNING TO SATURATE AGAIN LATE THIS EVENING FROM THE
SOUTH TO THE NORTH WITH MVFR...POSSIBLE IFR CONDITIONS...AND
FREEZING DRIZZLE. IT APPEARS KMCK WILL BE JUST NORTH OF THE LOWEST
CONDITIONS BASED ON MAIN LOW LEVEL MOISTURE AXIS (SHIFT IN WINDS
TO THE SOUTHEAST). WHILE THE TREAT FOR FREEZING DRIZZLE PREVAILING
IS BETTER AT KGLD THERE IS STILL A GOOD SHOT OF FREEZING DRIZZLE
BY 12-18Z. I COULDNT RULE OUT PRECIP MIXING WITH SLEET OR CHANGING
TO SNOW FOR BRIEF PERIODS...HOWEVER THIS IS LESS CERTAIN AND
CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE MENTION IN THE TAFS
DURING THIS UPDATE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1123 AM CST FRI NOV 27 2015
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST 04Z BEFORE SOME
MARINE LAYER CLOUD DECKS DEVELOP AND SPREAD OVER THE
REGION...SETTLING INTO IFR AND LOCALIZED LIFR CIGS BETWEEN 06Z AND
14Z...THEN IMPROVING THROUGH MVFR TO LOW END VFR BY 28/18Z. 24/RR
&&
.PREV DISCUSSION... /ISSUED 413 AM CST FRI NOV 27 2015/
DISCUSSION... SURFACE HIGH PRESSURE CONTINUES TO DOMINATE WEATHER
CONDITIONS ACROSS THE AREA. THIS RIDGE IS CURRENTLY ENCOMPASSES THE
ENTIRE SOUTHEASTERN UNITED STATES. A SURFACE TROUGH IS DRAPED OVER
THE CENTRAL CONUS FROM THE GREAT LAKES SOUTHWESTWARD TO CENTRAL
TEXAS AND THEN TO THE PERMIAN BASIN OF WEST TEXAS. IN THE UPPER
LEVELS...RIDGE CENTERED AROUND THE BAY OF CAMPECHE EXTENDS NORTHEAST
TO THE CENTRAL GULF COAST WHILE UPPER LOW ARE IN PLACE TO THE EAST
OVER THE BAHAMAS AND TO THE WEST NEAR NEVADA. THE LOCAL CWA REMAINS
IN MILD AND HUMID CONDITIONS WITH HIGH PRESSURE ALOFT KEEPING
DAYTIME HIGHS IN THE 70S AND RAIN CHANCES TO A MINIMUM. THERE AREA
FEW ECHOS SHOWING UP ON RADAR AND THE HRRR DOES DEPICT A FEW SHOWERS
TODAY BUT THINKING THE COVERAGE WILL BE TO LOW TO HAVE ANY MENTION
OF RAIN IN THE ZONE FORECAST TODAY THROUGH SATURDAY.
THE UPPER LEVEL LOW CURRENTLY CENTERED WEST OF THE ROCKIES WILL
GRADUALLY ROTATE EAST THROUGH THE WEEKEND. THIS SLOWER MOVEMENT WILL
KEEP THE COLD FRONT CURRENTLY TO THE NORTH NEARLY STATIONARY WELL
NORTHWEST OF THE CWA. MODELS SHOW THAT THIS FRONTAL BOUNDARY WILL
FINALLY START MOVING INTO THE LOCAL REGION EARLY TO MIDDLE OF NEXT
WEEK AS THE UPPER LOW BEGINS TRACKING MORE BRISKLY EAST ACROSS THE
CENTRAL PLAINS. THE E TO ENE TRACK OF THIS LOW WILL RESULT IN A
STRETCHING FRONT AS IT MOVES IN WHICH IS TYPICALLY A FAIRLY LOW
IMPACT EVENT WITH MINIMAL THUNDER THREAT AND GENERALLY LOWER RAIN
COVERAGE. IN FACT...DO NOT HAVE ANY THUNDER IN THE EXTENDING FCST AT
ALL. THE PROGRESSION OF SLIGHT CHANCE TO CHANCE POPS WILL BE FAIRLY
SLOW FROM NW TO SOUTHEAST. THIS RUN MODELS ARE EVEN SLIGHTLY SLOWER
THAN PREVIOUS WITH NWRN ZONES NOT SEEING ANY RAIN UNTIL LATE SUNDAY.
EVEN AS THE BOUNDARY MOVES THROUGH TUESDAY IT IS ENTIRELY POSSIBLE
THAT MANY LOCATIONS IN THE CWA DO NOT SEE RAIN AT ALL. THE ECMWF IS
ON THE WETTER SIDE HOWEVER WITH POP GUIDANCE IN THE 50 TO 70 PERCENT
RANGE VS MEX WHICH IS NOT EVEN HALF THAT. KEPT THE LONG TERM FCST
CLOSE TO THE PREVIOUS WHICH IS ON THE DRIER SIDE OF MODEL GUIDANCE.
MEFFER
AVIATION... NOT A LOT OF DIFFERENCE BETWEEN LAST 24HR AND THE NEXT.
CEILINGS WILL REMAIN IN THE 1.5K FT AREA THIS MORNING AND RISE TO
AROUND 2-3K FT DURING THE DAY TODAY BUT WILL BE INTERMITTENT AS LOW
LEVEL CLEARING WILL GIVE WAY TO DECKS AROUND 12-15K FT. TONIGHT WILL
BE ABOUT THE SAME AS CEILINGS WILL FALL ONCE AGAIN TO AROUND 1.5K FT
BUT SOME AREAS WILL BE IN AND OUT OF THE LOW LEVEL DECKS. WINDS WILL
BE VERY WEAK TO CALM OVERNIGHT. IF LOW LEVEL CEILINGS CLEAR FOR A
TIME THERE MAY BE SOME LIGHT FOG FORMATION. WILL SHOW THIS AS A
TEMPO GROUP TOWARD THE END OF THE 12Z TAF PACK BUT ONLY BRING DOWN
TO AROUND 3SM.
MARINE... HIGH PRESSURE OVER THE ATLANTIC COAST LINE WILL BE SLOW
TO MOVE THROUGH THE END OF THE WEEK. GUIDANCE HAS COME IN A LITTLE
SLOWER WITH THE PROGRESSION OF STORM SYSTEM AND HIGH PRESSURE
BREAKING DOWN AND WILL MAINTAIN CURRENT FORECAST WITH A FEW MINOR
TWEAKS. A COLD FRONT WILL PROGRESS SOUTHEASTWARD AND STALL NEAR
TEXARKANA TODAY. AS A RESULT...THE STRONG PRESSURE GRADIENT WILL
REMAIN OVER THE SOUTHERN US AND GULF COASTAL WATERS. EASTERLY WINDS
WILL REMAIN ELEVATED TODAY THEN SHIFT TO SOUTHEAST INTO THE WEEKEND.
THE COLD FRONT IS EXPECTED TO MOVE TO THE COAST AND STALL AGAIN BY
TUESDAY.
DECISION SUPPORT...
DSS CODE....GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 74 58 74 59 / 10 10 10 10
BTR 77 62 77 61 / 10 10 10 10
ASD 74 59 74 58 / 10 10 10 10
MSY 76 63 75 61 / 10 10 10 10
GPT 73 58 72 57 / 10 10 10 10
PQL 75 57 74 54 / 10 10 10 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ552-555-
570-572-575-577.
SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR GMZ536-538-550-557.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ555-570-
572-575-577.
SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR GMZ538-550-557.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
314 PM EST FRI NOV 27 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 313 PM EST FRI NOV 27 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NRN BRANCH NW FLOW
ALF PENETRATING INTO THE UPR LKS TO THE N OF PERSISTENT WRN TROF/SE
RDG SRN BRANCH FLOW REGIME DOMINATING THE CONUS. NW FLOW IN ADVANCE
OF SFC HI PRES CENTERED IN THE NCNTRL PLAINS IS ADVECTING COLDER AIR
INTO THE AREA...WITH UPSTREAM 12Z H85 TEMPS -13C AT INL AND -14C AT
YPL. THERE IS QUITE A BIT OF LK EFFECT CLD COVER OVER THE CWA...BUT
LO SUBSIDENCE INVRN...WITH INVRN BASE AT 12Z NEAR H9-925 AT INL AND
YPL...HAS GREATLY LIMITED THE INTENSITY AND COVERAGE OF THE LES
IMPACTING AREAS NEAR LK SUP. THE VERY DRY NATURE OF THE INCOMING
AIRMASS...WITH 12Z PWAT ABOUT 0.08 INCH AT BOTH INL/YPL /ABOUT 35
PCT OF NORMAL/...HAS ALSO HAD A NEGATIVE IMPACT ON PCPN. LO TEMPS
THIS MRNG WERE QUITE FRIGID AND AS LO AS -5 TO -10F UNDER SFC RDG
AXIS STRETCHING FM THE HI CENTER IN THE DAKOTAS INTO NW ONTARIO.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LO CLDS TRENDS/TEMPS AS DRY
HI PRES RDG IS FCST SLIDE SLOWLY SE THRU THE UPR LKS THRU SAT.
TNGT...AS SFC RDG AXIS/SHARP ACYC LLVL FLOW UNDER AREA OF DEEP LYR
QVECTOR DVGC AND LOWERING SUBSIDENCE INVRN BASE/DRY AIR SETTLES ACRS
UPR MI...EXPECT LINGERING LK CLDS TO CLR. WITH PWATS IN THE 0.1 TO
0.2 INCH RANGE/LIGHT WINDS/VERY LO TEMPS OBSVD UPSTREAM THIS MRNG...
WL FAVOR THE LO END OF GUIDANCE FOR MIN TEMPS FCST...ESPECIALLY IN
AREAS WITH SN COVER. ARRIVAL OF SHARPER PRES GRADIENT/STEADY W WINDS/
PERHAPS MORE PERSISTENT LK CLDS OVER THE KEWEENAW ON THE NRN FLANK OF
THE RDG AXIS PASSING TO THE S WL LIMIT THE DIURNAL TEMP DROP THERE.
SAT...LARGER SCALE SUBSIDENCE/STEADY W WINDS UNDER THE SHARPER PRES
GRADIENT/STEADY W FLOW TO THE N OF HI PRES RDG AXIS FCST TO STRETCH
FM MN ACRS WI INTO NRN LOWER MI ARE FCST TO LIFT H85 TEMPS INTO THE
0C TO -2C RANGE BY 00Z SUN. UNDER LINGERING AXIS OF DRY AIR...EXPECT
MOSUNNY SKIES. ALTHOUGH LOWERING SUN ANGLE WL LIMIT DEGREE OF DIURNAL
HEATING...STILL EXPECT TEMPS TO REBOUND INTO THE LO/MID 30S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 306 PM EST FRI NOV 27 2015
THE UPPER TROUGH CURRENTLY MOVING THROUGH EASTERN CANADA WILL
CONTINUE TO THE EAST THROUGH THE WEEKEND...AS AN UPPER RIDGE
REMAINS OVER THE CANADIAN ROCKIES. THIS WILL KEEP THE ARCTIC AIR
TRAPPED OVER FAR NORTHERN CANADA THROUGH THE LONG TERM PERIOD AND
LIKELY INTO NEXT WEEKEND. THUS...EXPECT TEMPERATURES TO BE AT OR
ABOVE NORMAL VALUES DURING THE LONG TERM FORECAST AND LOOKING AT
THE CFSV2 AND LONG RANGE ECMWF ENSEMBLES...THAT PATTERN LOOKS LIKE
IT WILL REMAIN THROUGH MUCH OF DECEMBER.
JUMPING BACK TO THE SHORTER TERM FORECAST...THE UPPER GREAT LAKES
REGION WILL BE BETWEEN THE DEPARTING EASTERN CANADIAN TROUGH AND A
UPPER LOW SLOWLY SHIFTING EAST OUT OF THE ROCKIES AND TOWARDS THE
GREAT LAKES REGION. THAT WILL LEAVE THE AREA THE AREA WITH NO UPPER
LEVEL SUPPORT FOR ANY SUBSTANTIAL PRECIPITATION SATURDAY THROUGH
MONDAY WITH HIGH PRESSURE OVER THE AREA FOR MUCH OF THAT PERIOD.
THERE IS ONE THING TO MENTION. A WEAK TROUGH MOVING ACROSS NORTHERN
LAKE SUPERIOR ON SATURDAY WILL SLOWLY VEER THE BL WINDS AROUND TO A
LIGHT NORTHERLY DIRECTION FOR A TIME LATE SATURDAY NIGHT INTO
SUNDAY. ASSOCIATED WITH THAT TURN TO THE NORTH...MODELS CONTINUE TO
SHOW LOW LEVEL MOISTURE TRAPPED BELOW THE SUBSIDENCE INVERSION
AROUND 920MB MOVING SOUTH INTO THE NORTHERN HALF OF THE CWA.
COMPARED TO YESTERDAY/S MODEL RUNS...THE CLOUD DEPTH IS SHALLOWER
AND VERY CLOSE TO THE SURFACE. WILL FOLLOW THE MORE PESSIMISTIC SIDE
OF THE FORECAST FOR CLOUD COVER LATE SATURDAY NIGHT INTO EARLY
SUNDAY AFTERNOON BASED OFF THE INDICATED LOW CLOUDS ON THE NAM/GFS
FOR AT LEAST THE NORTH HALF OF THE CWA. AS WINDS BECOME LIGHT SUNDAY
AFTERNOON AND THEN TURN BACK TO THE SOUTHWEST SUNDAY EVENING...WOULD
EXPECT THE CLOUDS TO PUSH BACK OUT OF THE AREA. WITH AS LOW AS THE
CLOUDS ARE INDICATED IN MODELS TODAY...MAY NEED TO BE CONCERNED
ABOUT REDUCED VISIBILITIES OVER THE NORTH CENTRAL FOR SUNDAY
MORNING.
FOR MONDAY NIGHT INTO WEDNESDAY...THE UPPER LOW THAT IS CURRENTLY
OVER THE ROCKIES WILL LIFT EAST-NORTHEAST THROUGH THE UPPER GREAT
LAKES REGION. AS THE UPPER LOW MOVES THROUGH THE CENTRAL PLAINS AND
A SHORTWAVE ROUNDS THE SOUTHERN SIDE OF THE LOW...A SURFACE LOW
WILL DEVELOP AND LIFT NORTHEAST WITH THE UPPER LOW. THAT SURFACE
LOW WILL TRACK ACROSS CENTRAL/EASTERN UPPER MICHIGAN TUESDAY NIGHT.
EXPECT PRECIPITATION TO LIFT NORTHEAST INTO THE AREA OVERNIGHT
MONDAY NIGHT AND THEN CONTINUE INTO TUESDAY NIGHT BEFORE QUICKLY
ENDING ON WEDNESDAY. MODELS HAVE TRENDED LOWER ON QPF
VALUES SINCE YESTERDAY...WITH VALUES GENERALLY BETWEEN A QUARTER AND
HALF AN INCH BY WEDNESDAY MORNING. THE OTHER TREND IN THE MODELS IS
FOR GENERALLY WARMER TEMPERATURES ALOFT UNDER THE UPPER LOW...WHICH
INCREASES THE RAIN POTENTIAL ACROSS THE CENTRAL/EASTERN U.P. BUT
IT STILL LOOKS LIKE THERE IS THE POTENTIAL FOR A FEW INCHES OF
SNOW ACCUMULATION OVER THE WESTERN THIRD OF THE U.P.. EXPECT THE
MAIN PUSH OF PRECIPITATION TO OCCUR LATE MONDAY NIGHT INTO EARLY
TUESDAY AFTERNOON IN ASSOCIATION WITH THE MID LEVEL WARM AIR
ADVECTION AHEAD OF THE UPPER LOW. THEN EXPECT JUST LIGHT
PRECIPITATION THE REST OF THE WAY AS THE UPPER LOW MOVES
THROUGH...ALTHOUGH THE FAR WEST COULD SEE SOME MODERATE SNOW AS
THE AREA OF FORCING FROM EARLIER IN THE DAY ROTATES AROUND THE
UPPER LOW AND IS FOCUSED OVER WESTERN LAKE SUPERIOR AND NEAR THE
WESTERN U.P.. AS THE LOW DEPARTS...DON/T THINK THERE WILL BE MUCH
OPPORTUNITY FOR LAKE ENHANCED/EFFECT SNOW...AS THE MID LEVELS
QUICKLY DRY OUT DUE TO THE APPROACHING UPPER RIDGE AND LOW LEVEL
TEMPERATURES STRUGGLE TO GET MUCH COLDER THAN -5C. THAT UPPER RIDGE
WILL SLIDE OVER THE AREA WEDNESDAY NIGHT AND LEAD TO DRY CONDITIONS
INTO THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1237 PM EST FRI NOV 27 2015
AS A HI PRES RDG/DRIER AIR MOVE SLOWLY ACROSS THE UPR LKS AND WINDS
GRADUALLY BACK TO THE WSW TNGT...EXPECT LINGERING LO CLDS/MVFR CIGS
TO GIVE WAY TO VFR CONDITIONS. CMX WL BE THE LAST TO SEE IMPROVEMENT
AS THE BACKING FLOW UPSLOPES THERE FOR A LONGER TIME.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 313 PM EST FRI NOV 27 2015
AS A HI PRES RIDGE STRETCHING FROM THE NORTHERN PLAINS INTO THE
CENTRAL GREAT LAKES TONIGHT...A STRENGTHENING WSW WIND UP TO 25-30
KTS WILL DEVELOP OVER LAKE SUPERIOR UNDER THE TIGHT PRES GRADIENT
AND LO PRES CROSSING NRN ONTARIO. THE STRONGEST WINDS WILL OCCUR
BETWEEN ISLE ROYALE AND THE KEWEENAW...WHERE TERRAIN INFLUENCES
TYPICALLY ACCENTUATE THIS FLOW. THESE STRONGER WINDS WILL DIMINISH
STEADILY LATER ON SAT AND VEER TO THE NE THRU SUN AS A WEAK LO PRES
TROF/SLACKER GRADIENT DIP INTO THE UPPER LAKES AND HI PRES BUILDS
INTO NW ONTARIO. ONCE THE HI SHIFTS TO THE E...EXPECT LIGHT S WINDS
ON MON. A STRONGER E WIND UP TO 25 KTS WILL THEN DEVELOP ON TUE AS A
DEEP LO PRES MOVES INTO THE UPPER MIDWEST. WINDS WILL SHIFT TO THE
NNW ON WED FOLLOWING THE PASSAGE OF THIS LO TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
915 AM PST FRI NOV 27 2015
.SYNOPSIS...A COLD UPPER LOW WILL REMAIN IN PLACE OVER THE
WEEKEND...KEEPING TEMPERATURES 10-15 DEGREES BELOW NORMAL. ISOLATED
SNOW SHOWERS ARE POSSIBLE THROUGH TONIGHT ACROSS THE SOUTHERN SIERRA
AND NORTHEASTERN LINCOLN COUNTY. OTHERWISE EXPECT VARIABLE PASSING
CLOUDS THROUGH SUNDAY. IMPROVING CONDITIONS AND MODERATING
TEMPERATURES ARE EXPECTED BY EARLY NEXT WEEK. &&
.UPDATE...A FEW LIGHT (MOSTLY VIRGA SHOWERS) EXIST ACROSS EASTERN
CLARK AND MOHAVE COUNTIES THIS MORNING WITH SOME LIGHT SHOWERS ALSO
EVIDENT ON SATELLITE ACROSS THE SIERRA. EXPECT THIS TO CONTINUE MUCH
OF THE DAY BUT ANY PRECIPITATION AMOUNTS WILL BE QUITE LIGHT. I
BOOSTED POPS UPWARDS VERY SLIGHTLY FOR THE HIGHER TERRAIN OF THE
SPRING MOUNTAINS...NORTHERN MOHAVE COUNTY...AND THE SIERRA BUT
OTHERWISE DRY CONDITIONS ARE EXPECTED TODAY.
ALSO TWEAKED SKY COVER A BIT BUT OVERALL THE FORECAST IS IN GOOD
SHAPE.
-OUTLER-
&&
.SHORT TERM...TODAY THROUGH SUNDAY.
REX BLOCK PATTERN CONTINUES TO HOLD TONIGHT...KEEPING OUR PERSISTENT
UPPER LEVEL LOW OVER THE REGION AND BELOW AVERAGE TEMPERATURES ON
THE HORIZON THROUGH THE END OF THE WEEKEND. THUS FAR...TEMPERATURES
ARE HOLDING HIGHER THAN EXPECTED IN PORTIONS OF THE FREEZE WARNING
AREA TONIGHT...ESPECIALLY IN THE LAS VEGAS VALLEY WHERE NORTHWEST
WINDS DEVELOPED EARLIER THIS EVENING. THIS CONTINUES TO MIX OUT THE
COLDER AIR AT THE SURFACE...CURRENTLY KEEPING TEMPERATURES GENERALLY
BETWEEN 40-45F ACROSS MOST VALLEY LOCALES AT THE 2AM HOUR. PORTIONS
OF SUMMERLIN AND MOUNTAINS EDGE ARE CURRENTLY COMING IN IN THE MID
TO UPPER 30S AT THIS HOUR.
EXPECT CLOUDS ASSOCIATED WITH A SUB-SYNOPTIC LOW OFF OF THE SOUTHERN
CALIFORNIA COAST TO SPREAD EASTWARD ACROSS THE REGION
TODAY...HELPING TO KEEP TEMPERATURES DOWN. THERE WILL BE SUFFICIENT
ENOUGH MOISTURE COMBINED WITH COLD TEMPERATURE PROFILES TO YIELD
ISOLATED SNOW SHOWERS...MAINLY ACROSS NORTHWESTERN INYO COUNTY AND
NORTHEASTERN LINCOLN COUNTY TODAY AND TONIGHT. LOCAL HI-RES MODELS
AND THE LAST SEVERAL RUNS OF THE HRRR ALSO HINT AT ISOLATED SNOW
SHOWERS DEVELOPING IN THE SPRING MOUNTAINS AND SHEEP RANGE AROUND
20Z THIS AFTERNOON. HOWEVER...ACCUMULATIONS ARE EXPECTED TO BE
MINIMAL IN ALL AREAS.
SUNDAY...00Z OPERATIONAL MODEL GUIDANCE IS IN GOOD AGREEMENT IN A
WEAK SHORTWAVE GETTING PULLED INTO THE STAGNANT LOW...YIELDING A
QUICK INCREASE IN CLOUD COVER ACROSS OUR SOUTHERN ZONES DURING THE
DAY. MORE IMPORTANTLY...GUIDANCE SEEMS TO BE ONBOARD WITH THE
EVOLUTION OF THE NEXT SHORTWAVE THAT WILL KICK OUR STAGNANT LOW
EASTWARD...BREAKING THE REX BLOCK PATTERN. AS A RESULT...CLEARING
SKIES AND A SLIGHT WARMUP WILL BE THE STORY SUNDAY AS OUR LOW
DEPARTS THE AREA AND SHORTWAVE RIDGING BEGINS TO MOVE IN LATE SUNDAY
NIGHT.
.LONG TERM...MONDAY THROUGH THURSDAY.
AFTER A FEW WEEKS OF FAIRLY ACTIVE WEATHER...THE UPCOMING EXTENDED
PERIOD APPEARS TO RELATIVELY TAME. SHORTWAVE RIDGING AND QUIET
WEATHER MONDAY WILL GIVE WAY TO SOME WEAK SHORTWAVE ENERGY MOVING
THROUGH THE REGION. THIS MAY BRIEFLY ENHANCE NORTHERLY WINDS ACROSS
THE REGION TUESDAY...PARTICULARLY IN FAVORED AREAS SUCH AS THE
COLORADO RIVER VALLEY. RIDGING TAKES CONTROL AGAIN FOR WEDNESDAY AND
THURSDAY BRINGING MORE QUIET WEATHER. TEMPERATURES ARE LIKELY TO
CLIMB SLIGHTLY ABOVE NORMAL BY MID-LATE WEEK.
&&
.AVIATION...FOR MCCARRAN...GUSTY NORTHWEST WINDS ARE EXPECTED TO
CONTINUE AT THE TERMINAL THROUGH LATE MORNING...WITH SPEEDS RANDING
BETWEEN 10-15KTS AND GUSTS BETWEEN 20-25KTS AT TIMES. WINDS LOOK
TO DECREASE BY EARLY AFTERNOON AT SPEEDS AROUND 10KTS.
EXPECT THIS PATTERN TO HOLD THROUGH THIS EVENING BEFORE WINDS BECOME
LIGHT AND VARIABLE ONCE AGAIN. EXPECT SCT-BKN CIGS TODAY AOA 15KFT
WITH SCT AS LOW AS 8KFT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...EXPECT GUSTY NORTHERLY WINDS TO CONTINUE AT KVGT
THROUGH DAYBREAK...WITH SPEEDS BETWEEN 10-15KTS AND GUSTS 20-25KTS.
EXPECT NORTHERLY WINDS TO CONTINUE ACROSS THE LAS
VEGAS...OWENS...AND COLORADO RIVER VALLEYS TODAY WITH SPEEDS
GENERAL RANGING BETWEEN 10-15KTS AND GUSTS OF 20-25KTS AWAY FROM
THE LAS VEGAS VALLEY. KDAG WILL SEE VARIABLE DIRECTIONS WITH SPEEDS
GENERALLY REMAINING BELOW 10KTS. EXPECT SCT-BKN CIGS GENERALLY UNDER
10KFT ACROSS THE REGION TODAY...WITH ISOLATED SNSH AND LOCAL
MOUNTAIN OBSCURATIONS POSSIBLE IN THE SOUTHERN SIERRA NEAR KBIH
TODAY.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...PULLIN
LONG TERM.............WOLCOTT
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
251 PM CST FRI NOV 27 2015
.DISCUSSION...
FEW CHANGES HAVE BEEN TO THE ONGOING FORECAST PACKAGE...WITH A
VERY MILD AND WET WEEK AHEAD FOR THE MID STATE. RADAR IMAGERY
THIS AFTERNOON SHOWS LIGHT RAIN CONTINUES PROGRESSING EASTWARD
ACROSS WEST TENNESSEE INTO OUR WESTERN ZONES. LATEST 12Z MODEL
GUIDANCE AND 19Z HRRR INDICATE LIGHT RAIN WILL CONTINUE TO
GRADUALLY INCREASE IN COVERAGE ACROSS THE NORTHWEST HALF OF THE
CWA THIS EVENING AND OVERNIGHT...THEN SPREAD FURTHER EAST ON
SATURDAY. RAIN ANTICIPATED TO BECOME EVEN MORE WIDESPREAD AND OF
HEAVIER INTENSITY SATURDAY NIGHT INTO SUNDAY AS A COLD FRONT SLIPS
INTO NORTHWEST MIDDLE TENNESSEE...AND A WEAK AREA OF LOW PRESSURE
RIDES UP THE FRONT ACROSS THE CWA. TEMPS WERE KEPT CLOSE TO
PREVIOUS VALUES THROUGH SUNDAY WITH LOWS IN THE 50S AND HIGHS IN
THE 50S/60S...WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
MODELS INDICATE RAIN WILL SLACKEN OFF SOME LATE SUNDAY NIGHT INTO
EARLY MONDAY...BEFORE INCREASING AGAIN MONDAY NIGHT INTO TUESDAY
AS THE MAIN UPPER LEVEL LOW AND ASSOCIATED 80 KT H5 SPEED MAX
EJECTS EASTWARD ACROSS THE MIDWEST. LATEST GFS FORECAST SOUNDINGS
SHOW K-INDEX VALUES IN THE MID 30S AND LI VALUES OF -1 ON MONDAY
NIGHT...SO WILL MENTION A SLIGHT CHANCE FOR THUNDERSTORMS DURING
THAT TIMEFRAME ALTHOUGH POTENTIAL IS LOW. TOTAL QPF THROUGH NEXT
WEDNESDAY IS A BIT HIGHER THAN PREVIOUS FORECASTS WITH MOST AREAS
LOOKING TO SEE 2 TO 3 INCHES OF RAIN...ALTHOUGH GFS AND ECMWF
REMAIN A BIT HIGHER IN THE 2 TO 4 INCH RANGE.
NORTHWEST FLOW IN THE WAKE OF THE UPPER LOW WILL DRY OUR AREA OUT
FROM WEST TO EAST ON WEDNESDAY...BUT 12Z GFS/ECMWF INDICATE
ANOTHER UPPER TROUGH WILL SHIFT ACROSS THE SOUTHEASTERN CONUS
THURSDAY INTO FRIDAY...WITH GFS INDICATING ANOTHER ROUND OF LIGHT
RAIN BUT EMCWF KEEPING US DRY. WILL SHOW LOW POPS DURING THIS TIME
PERIOD IN AGREEMENT WITH SURROUNDING OFFICES. COOLER TEMPS LOOK
LIKELY FOR LATE NEXT WEEK WITH READINGS CLOSER TO NORMAL FOR THIS
TIME OF YEAR...WITH LOWS IN THE 30S AND HIGHS IN THE 40S/50S.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 58 67 56 61 / 40 60 80 80
CLARKSVILLE 58 62 51 58 / 80 80 80 80
CROSSVILLE 53 64 55 61 / 10 20 60 80
COLUMBIA 57 67 56 61 / 30 40 80 80
LAWRENCEBURG 56 68 56 62 / 20 30 70 80
WAVERLY 58 64 53 59 / 60 70 80 80
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
233 PM CST FRI NOV 27 2015
.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
AS OF 3 PM...THE COLD FRONT WAS LOCATED ALONG A LINE FROM NEAR
LEXINGTON TO AUSTIN TO DEL RIO. TEMPERATURES AHEAD OF THE BOUNDARY
ARE IN THE MIDDLE TO UPPER 70S WITH TEMPS BEHIND THE FRONT QUICKLY
DROPPING INTO THE 40S. THE FRONT IS SLOWLY PUSHING SOUTH AND
EXPECT IT TO CONTINUE TO DO SO THROUGH THE REST OF THE AFTERNOON
AND EVENING. THE FRONT SHOULD BE AT OUR SOUTHERN BORDER AROUND
MIDNIGHT AND THEN CLEAR THE AREA SHORTLY AFTER. SOME OF THE MODEL
GUIDANCE IS COMING IN WITH SLIGHTLY HIGHER TOTALS FOR OUR AREA
FOR TONIGHT JUST BEHIND THE FRONTAL BOUNDARY. THE GFS IS SHOWING
SOME 2 INCH IN 6 HOUR RAIN TOTALS FOR THE I-35 CORRIDOR BEHIND
THE FRONT. AM A BIT SKEPTICAL OF AMOUNTS THIS HIGH FOR THIS
AREA...BUT IT IS WORTH NOTING. THE GFS SEEMS TO HAVE INITIALIZED
THE PW VALUES TOO HIGH WITH 2 INCH VALUES ACROSS THE SOUTHEASTERN
HALF OF THE AREA. THE SPC MESOANALYSIS ONLY SHOWS 1.8
INCHES...WHICH IS STILL ABNORMALLY HIGH FOR THIS TIME OF THE YEAR.
DO THINK RAIN WILL FALL FOR THE I-35 CORRIDOR AND EVEN IF 2 INCHES
FALL OVER 6 HOURS...RAIN RATES SHOULD BE LESS THAN AN INCH PER
HOUR AS THE BULK OF THE HEAVY RAIN WILL FALL IN THE COLD SECTOR
AND THE BEST WARM-RAIN PROCESSES WILL BE SHUT DOWN.
CONTINUE TO THINK THE HIGHER AMOUNTS OF QPF MAY ACTUALLY FALL
ACROSS THE WESTERN COUNTIES....BETWEEN DEL RIO AND SAN ANTONIO.
THE VARIOUS WRF MODELS AND NOW THE HRRR CONTINUE TO PROG A WEAK
SURFACE TROUGH TO DEVELOP NEAR DEL RIO...THEN TRACK TO THE ESE IN
THE EVENING HOURS. THIS FEATURE WOULD LIKELY HELP LOCALLY ENHANCE
THE LIFT TO SUPPORT BETTER PRECIPITATION RATES. THE LOW WILL ALSO
ALLOW FOR SLIGHTLY WARMER TEMPERATURES TO PERSIST IN THE AREA AS
SOME OF THE AIR BECOMES WRAPPED AROUND THE SURFACE LOW ALSO
ALLOWING FOR SLIGHTLY BETTER PRECIP RATES. IN ADDITION TO THE
EXPECTED SURFACE TROUGH...850 MB MOISTURE TRANSPORT VECTORS ARE
POINTING TO THIS REGION AS WELL FOR THE BEST POTENTIAL FOR
HEAVIER RAINFALL. WE ARE ALREADY SEEING MORE ENHANCEMENT IN THE
REFLECTIVITIES ACROSS THE WESTERN COUNTIES VERSUS THE EASTERN AND
THIS IS LIKELY THE REASON. OUR STORM TOTAL PRECIP GRAPHIC FOR THIS
EVENING THROUGH SUNDAY WILL SHOW THE HIGHEST AMOUNTS ALONG AN AXIS
FROM ZAVALA COUNTY UP INTO MEDINA/UVALDE AND NORTHEAST INTO THE
HILL COUNTRY AND I-35 CORRIDOR. AM EXPECTING 1-2 INCHES OF
ADDITIONAL RAIN FOR THIS AREA WITH ISOLATED AMOUNTS REACHING 4+.
WHILE THERE ARE ABNORMALLY HIGH AMOUNTS OF MOISTURE IN THE
ATMOSPHERE AND A FRONT...THERE ARE SEVERAL INGREDIENTS LACKING FOR
A MORE SIGNIFICANT RAINFALL EVENT FOR OUR AREA. THE FIRST IS DEEP
FORCING FOR LIFT IN THE ATMOSPHERE. THE AREA REMAINS BETWEEN THE
UPPER LOW CENTERED OVER UTAH AND A RIDGE IN THE GULF OF MEXICO.
THE BEST SHEAR AXIS /LIFT/ REMAINS WELL NORTH OF THE AREA. THIS
MEANS OUR MAIN LIFTING MECHANISM WILL BE WARM AIR ADVECTION OVER
THE FRONTAL INVERSION. SECOND...OUR REGION IS ALSO UNDERNEATH THE
RIGHT EXIT REGION OF THE UPPER JET WHICH ALSO ISNT FAVORABLE FOR
DEEP CONVECTION. THIRD...WE DO HAVE A COLD FRONT IN PLACE BUT
THIS FRONT IS NOT EXPECTED TO STALL AND THUS WILL NOT SERVE AS A
FOCUS FOR TRAINING OF CONVECTION. LASTLY...THE 850 FRONT WILL
REMAIN NORTH OF THE AREA...DETACHED FROM THE SURFACE FRONT WHICH
WILL NOT ENHANCE FRONTAL LIFT ALONG THE BOUNDARY. TO
SUMMARIZE...WE ARE STILL EXPECTING SOME HIGHER RAIN AMOUNTS IN
LOCALIZED PLACES...BUT WE ARE LACKING MECHANISMS FOR INTENSE
RAINFALL RATES OUT OF THE EXPECTED ACTIVITY.
LOWS TONIGHT WILL DROP INTO THE 30S/40S FOR MUCH OF THE AREA AND
HIGHS TOMORROW WILL NOT WARM MUCH FROM THOSE VALUES. OVERRUNNING
CONDITIONS ARE EXPECTED TO PERSIST TOMORROW AFTERNOON AND WILL
CONTINUE WITH FAIRLY HIGH RAIN CHANCES. PRECIP AMOUNTS SHOULD BE
LESS TOMORROW AS THE MID-LEVELS DRY OUT FROM TODAY. THE MID-LEVELS
WILL CONTINUE TO DRY SATURDAY NIGHT...LOWERING RAIN AMOUNTS EVEN
FURTHER. THE HIGHER RAIN CHANCES AND PRECIP AMOUNTS ARE EXPECTED
TO BE NORTH OF AREA...IN CLOSER PROXIMITY TO THE SHEAR AXIS. LOWS
TOMORROW NIGHT WILL DROP DOWN INTO THE 30S AND 40S ONCE AGAIN.
&&
.LONG TERM (SUNDAY THROUGH FRIDAY)...
FOR SUNDAY...HIGH TEMPERATURES WILL REBOUND A BIT...BUT NOT BY
MUCH AS NORTH WINDS REMAIN AT THE SURFACE. SOUTHWEST FLOW ALOFT
WILL ALSO PERSIST AND EXPECT LOW POPS TO CONTINUE FOR LIGHT
SHOWERS. UPPER FLOW IS EXPECTED TO BECOME MORE WESTERLY BY MONDAY
WHICH SHOULD SHIFT THE RAIN CHANCES TO THE EASTERN HALF OF THE
AREA...AND THESE POPS WILL ONLY BE 20 PERCENT.
THE STRONG UPPER LOW CURRENTLY OVER UTAH WILL FINALLY PUSH EAST
AND EJECT INTO THE PLAINS BY MONDAY AFTERNOON. THIS WILL SEND
ANOTHER REINFORCING COLD FRONT INTO THE AREA MONDAY NIGHT INTO
TUESDAY NIGHT. THIS WILL ALLOW NORTH FLOW TO CONTINUE FOR THE
REMAINDER OF THE FORECAST WHICH SHOULD EQUATE TO CONTINUED BELOW
NORMAL TEMPERATURES. LARGE SCALE LIFT ARRIVES TO THE AREA TUESDAY
NIGHT INTO WEDNESDAY AS AN OPEN TROUGH APPROACHES THE AREA. THIS
SHOULD ALLOW FOR DECENT ISENTROPIC LIFT TO SET UP OVER THE AREA
AND WE COULD SEE MORE WIDESPREAD RAIN DEVELOP. THIS ACTIVITY LOOKS
TO BE MUCH LIGHTER THAN THE CURRENT EVENT AND MORE TYPICAL FOR
THE WINTER SEASON. THE FORECAST WILL DRY OUT FOR THURSDAY AND
FRIDAY WITH CONTINUED BELOW NORMAL TEMPERATURES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 44 46 43 49 45 / 90 80 70 60 30
AUSTIN BERGSTROM INTL AIRPORT 43 47 44 49 44 / 80 80 70 60 30
NEW BRAUNFELS MUNI AIRPORT 45 47 44 51 45 / 80 80 70 60 20
BURNET MUNI AIRPORT 41 44 40 47 42 / 90 80 70 70 20
DEL RIO INTL AIRPORT 41 47 44 57 45 / 80 60 50 30 -
GEORGETOWN MUNI AIRPORT 40 44 41 48 42 / 90 80 70 70 30
HONDO MUNI AIRPORT 43 48 44 53 46 / 90 80 70 50 10
SAN MARCOS MUNI AIRPORT 44 46 44 50 45 / 80 80 70 60 30
LA GRANGE - FAYETTE REGIONAL 50 50 44 51 48 / 80 70 60 60 30
SAN ANTONIO INTL AIRPORT 47 48 45 51 47 / 90 80 70 60 20
STINSON MUNI AIRPORT 49 50 46 53 48 / 80 80 70 50 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...TREADWAY
SYNOPTIC/GRIDS...HAMPSHIRE
PUBLIC SERVICE/DATA COLLECTION...LH
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1015 AM CST FRI NOV 27 2015
.DISCUSSION...
TEXAS COLD FRONT IS MAKING STEADY PROGRESS SOUTHWARD THIS MORNING.
SOUTHEAST TEXAS TEMPERATURES AHEAD OF THE FRONT ARE IN THE 70S...AND
READINGS ARE QUICKLY FALLING INTO THE UPPER 40S TO LOWER 50S BEHIND
THE BOUNDARY. EXPECT THE FRONT TO MAKE IT INTO OUR NORTHERN COUNTIES
LATE THIS AFTERNOON OR EARLY THIS EVENING. WEAK DISTURBANCES IN THE
SOUTHWEST FLOW ALOFT WILL HELP TO PRODUCE SOME RAIN ACROSS PARTS OF
SOUTHEAST TEXAS TODAY (SHOWERS AND MAYBE AN ISOLATED THUNDERSTORM OR
TWO) WITH THE BETTER CHANCES NORTH AND NORTHWEST. EXPECT TO SEE INCREASING
RAIN COVERAGE TONIGHT AS THE FRONT MAKES SLOW PROGRESS ACROSS OUR AREA.
STILL THINK WE COULD BE LOOKING AT AN ALMOST 20 TO 25 DEGREE SPREAD
IN HIGH TEMPERATURES OVER THE WEEKEND FROM IN/AROUND THE COLLEGE STATION
AREA) TO IN/AROUND THE GALVESTON BAY AREA IF THE FRONT STALLS NEAR THE
COAST. 42
&&
.PREV DISCUSSION... /ISSUED 554 AM CST FRI NOV 27 2015/
DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
AS OF 11Z...ONLY KIAH/KHOU WERE EXPERIENCING IFR/LIFR CIGS DUE TO
SEA FOG DEVELOPING OFF GALVESTON BAY. EXPECT LOW CIGS AT THESE
TERMINALS THROUGH 14-15Z THIS MORNING. OTHERWISE WE HAVE A HODGE
PODGE OF CEILINGS ACROSS THE AREA WITH VFR AT KGLS/KLBX AND MVFR
FOR KSGR/KCXO/KUTS/KCLL. OVERALL THINK CEILINGS RISE TO
2000-3000FT LEVELS WITH VFR/MVFR CIGS THROUGH THE AFTERNOON MUCH
LIKE YESTERDAY. CIGS THEN DROP AFTER SUNSET TO MVFR AND THEN IFR
AS NO REAL CHANGE IN THE AIRMASS. THAT CHANGE IN AIRMASS IS COMING
IN THE FORM OF A COLD FRONT. ADDED WIND SHIFT FOR MOST TAFS FROM
00Z TO 09Z SAT FOR ALL TAFS EXCEPT FOR KLBX/KGLS WHERE THE FRONT
MIGHT NOT REACH ASSUMING IT STALLS. BASED FROPA ON LATEST HRRR AND
WRF ARW/NMM RUNS. FRONT SEEMS TO BE MOVING FASTER THAN THESE
MODELS ANYWAY. THIS PUTS THE FRONT INTO KCLL RIGHT AROUND 00Z AND
THEN KIAH AROUND 09Z SO IT DOES TAKE ITS TIME PUSHING SOUTH AND
WHY IT MAY STALL. ALSO NOTE THAT THIS IS ABOUT 6-12 HOURS FASTER
THAN THE LATEST NAM/GFS RUNS. BASICALLY THE FROPA AND WIND SHIFT
IS A LOW CONFIDENCE FORECAST BUT ONE THAT COULD REASONABLY OCCUR.
SUSPECT THAT THE TIMING OF THE WIND SHIFT AND FRONT WILL CHANGE
WITH BETTER GUIDANCE AND FUTURE TAF UPDATES. REGARDLESS OF WHEN
THE FRONT PUSHES THROUGH...CIGS MAY NOT CHANGE MUCH AND REMAIN IN
THE IFR/MVFR CATEGORIES GOING INTO SATURDAY.
39
PREV DISCUSSION... /ISSUED 438 AM CST FRI NOV 27 2015/
DISCUSSION...
SE TEXAS CONTINUED BETWEEN AN UPPER LEVEL RIDGE OVER THE GULF OF
MEXICO AND AN UPPER LEVEL TROUGH ACROSS THE NORTHERN PLAINS AND
CENTRAL ROCKIES. A COLD FRONT WAS ALSO MOVING SLOWLY THROUGH THE
NORTHERN AND CENTRAL PORTIONS OF THE STATE AT 4 AM. BECAUSE OF
THE PROXIMITY OF THE UPPER LEVEL HIGH PRESSURE RIDGE...THE BEST
MOISTURE AXIS WAS ACROSS CENTRAL AND NORTHERN TEXAS EARLY THIS
MORNING. THE MAIN FORECAST ITEM OF CONCERN INCLUDE INCREASING RAIN
CHANCES TODAY THROUGH THE WEEKEND AS A COLD FRONT MOVES INTO THE
AREA.
THERE WERE SOME SLIGHT MODEL DIFFERENCES REGARDING THE TIMING OF
THE COLD FRONTAL PASSAGE. A MODEL CONSENSUS HAS THE FRONT ENTERING
THE COLLEGE STATION AREA DURING THE EARLY EVENING PERIOD LATER
TODAY. THE FRONT WILL THEN BE SLOW TO MOVE THROUGH THE FORECAST
AREA TONIGHT AND SATURDAY...AND MAY STALL BEFORE REACHING THE
COAST DURING THE DAY ON SUNDAY. A CONSENSUS OF THE MODELS HAS THE
BEST CHANCES OF RAIN TONIGHT AND SATURDAY ALONG AND BEHIND THE
COLD FRONT AS IT MOVES SLOWLY INTO THE FORECAST AREA.
BEST RAINFALL AMOUNTS OVER THE NEXT 4-DAY PERIOD ARE STILL
EXPECTED TO BE OVER THE NORTHWESTERN SET OF COUNTIES. MODEL PW/S
DO REACH A MAXIMUM OF 1.8 TO 2.0 INCHES ON SATURDAY...MAINLY OVER
THE NORTHWESTERN HALF OF THE FORECAST AREA. HOWEVER...MODEL
SOUNDING PROFILE FORECASTS ARE STILL NOT VERY CONDUCIVE FOR
THUNDERSTORM DEVELOPMENT. A MODEL CONSENSUS HAS A 4-DAY RAINFALL
TOTAL BY MIDDAY MONDAY RANGING FROM 1 TO 2 INCHES ALONG AND NORTH
OF A LINE FROM GROVETON TO HUNTSVILLE TO BRENHAM. LESS THAN ONE
HALF OF AN INCH IS FORECAST BY THE MODELS ALONG AND SOUTH OF A
LINE FROM LIBERTY TO HOUSTON TO BAY CITY.
LESSONING CHANCES OF RAIN IS EXPECTED ON MONDAY OVER MOST AREAS.
AN UPPER LEVEL LOW PRESSURE TROUGH IS THEN EXPECTED TO MOVE ACROSS
THE PLAINS BY THE MIDDLE OF NEXT WEEK. THIS SYSTEM WILL BRING
INCREASING CHANCES OF RAIN TUESDAY AND WEDNESDAY.
MARINE...
A COLD FRONT WILL APPROACH SE TX TONIGHT AND SATURDAY. THE FRONT MAY
PUSH OFF THE UPPER TX COAST LATER ON SUNDAY. UNTIL THEN FRESH TO
STRONG SE WINDS WILL CONTINUE WITH ROUGH SEAS OFFSHORE. ADVISORIES
AND CAUTIONS WILL CONTINUE THROUGH THE MORNING HOURS. WINDS SHOULD
BE DECREASING THIS AFTERNOON AND EXPECT SEAS TO DECREASE SOME. THERE
ARE SOME LONGER PERIOD SWELLS MIXED WITH WIND WAVES WHICH MAY KEEP
SEAS AT MODERATE TO ROUGH LEVELS. SEAS SHOULD DECREASE FURTHER
SUNDAY INTO MONDAY AS WINDS DECREASE AHEAD OF THE COLD FRONT. THE
FRONT SHOULD SHIFT WINDS TO THE NORTH MONDAY BUT SHOULD NOT BE VERY
STRONG. A STRONGER COLD FRONT MAY PUSH OFF THE COAST TUESDAY NIGHT
INTO WEDNESDAY. STRONG NORTHEAST WINDS MAY DEVELOP IN ITS WAKE LATER
ON WEDNESDAY.
SEA FOG...IT APPEARS THAT SEA FOG MAY NOT FORM SINCE WATER TEMPS
HAVE INCREASED AND MOISTURE LEVELS REMAIN JUST LOW ENOUGH THAT FOG
MAY NOT FORM.
COASTAL FLOOD POTENTIAL...TIDES AT EAGLE POINT AND GALVESTON NORTH
JETTY ARE ABOUT 1.5 TO 1.9 FEET ABOVE ASTRONOMICAL LEVELS THIS
MORNING. THIS IS LEADING TO TOTAL WATER LEVELS OF AROUND 3 FEET
ABOVE MLLW. HIGH TIDE AT GALVESTON NORTH JETTY THIS EVENING AROUND
6PM CST IS ABOUT 2 FEET ABOVE MLLW SO ADDING AN ADDITIONAL 1.5 FEET
WOULD YIELD WATER LEVELS AROUND 3.5 FEET ABOVE MLLW. ONCE AGAIN
THESE LEVELS WOULD CAUSE IMPACTS TO HIGHWAY 87 ALONG BOLIVAR
PENINSULA. A COASTAL FLOOD ADVISORY MAY BE NEEDED AGAIN SHOULD THESE
TIDE TRENDS CONTINUE INTO THE AFTERNOON.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 49 50 46 53 / 50 70 60 70 60
HOUSTON (IAH) 78 65 69 57 67 / 30 40 40 40 30
GALVESTON (GLS) 75 68 74 64 72 / 20 20 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 3 PM CST THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
934 AM PST FRI NOV 27 2015
.SYNOPSIS...A STRONG UPPER HIGH WILL SLOWLY MEANDER EASTWARD
ACROSS SOUTHERN BRITISH COLUMBIA FROM NOW THROUGH SUNDAY...WITH
SOME SLOW WEAKENING ON BEGINNING ON SUNDAY. THIS WILL KEEP
WESTERN WASHINGTON CLEAR AND DRY THROUGH THE REMAINDER OF
THANKSGIVING WEEKEND. THE UPPER HIGH WILL BREAK DOWN AT THE START
OF NEXT WEEK...ALLOWING PACIFIC FRONTAL SYSTEMS TO BRING A RETURN
TO MORE TYPICALLY WET WEATHER.
&&
.SHORT TERM...A STRONG BLOCKING UPPER HIGH WAS CENTERED OVER
NORTHERN VANCOUVER ISLAND THIS MORNING...WITH THE 12Z PORT HARDY
SOUNDING REGISTERING A 500 MB HEIGHT OF 575 DECAMETERS. IT WILL
TAKE ALL THE WAY THROUGH SUNDAY FOR THIS FEATURE TO SLOWLY MEANDER
EASTWARD ACROSS SOUTHERN B.C.. IN THE MEANTIME...IT WILL CONTINUE
TO SUPPORT DRY NE/E FLOW ALOFT OVER WRN WA...AND THE WARM AIR
ALOFT WILL LEAD TO STABLE CONDITIONS WITH STRONG LOW-LEVEL
INVERSIONS.
SO THAT LEAVES AIR STAGNATION AS THE MAIN ISSUE WITH WHICH TO
CONTEND. ALREADY THIS MORNING...BOTH MARYSVILLE AND SOUTH TACOMA
WERE IN THE AIR QUALITY CATEGORY OF UNHEALTHY FOR SENSITIVE
GROUPS DUE TO WOOD SMOKE. QUALITATIVELY...THERE IS A LITTLE MORE
LOW-HANGING BROWN HAZE OUT THE WINDOW HERE IN NORTHEAST SEATTLE
THIS MORNING THAN YESTERDAY. LOOKING AHEAD...PRESSURE GRADIENTS
WILL BE QUITE WEAK THROUGH SUNDAY...AND THE WARMEST AIR ALOFT
APPEARS TO COME ON SATURDAY NIGHT. WILL MOSTLY LIKELY TAKE UNTIL
MONDAY FOR SMOKE DISPERSION TO IMPROVE.
BY MONDAY...BOTH THE 12Z GFS AND 12Z NAM MODELS TAKE THE WEAKENED
CENTER OF OUR BLOCKING HIGH EAST INTO ALBERTA. THIS WOULD ALLOW A
SHORTWAVE IMPULSE TO BRUSH THE AREA ON MONDAY. AT THE LEAST...THIS
WOULD IMPROVE MIXING AND AIR QUALITY BY REMOVING THE CAP OF WARM
AIR ALOFT AND BRINGING A MODEST INCREASE IN WIND. AT THE MOST...IT
COULD ALSO BRING SOME CLOUDS AND A LITTLE RAIN. REGARDING
RAIN...AMOUNTS WOULD BE LIGHT. IT IS FAIRLY TYPICAL FOR THE FIRST
SYSTEM TRYING TO BUDGE A BLOCKING HIGH TO FIZZLE AS IT FIGHTS ITS
WAY INTO A DRY AIR MASS...BUT IT MAY ALSO HELP OPEN THE DOOR FOR A
RETURN TO TYPICALLY WET AND ACTIVE WEATHER BEYOND MONDAY. WILL
HAVE TO CONSIDER INCREASING POPS FOR MONDAY IN THE NEXT FORECAST
PACKAGE.HANER
.LONG TERM...FROM PREVIOUS DISCUSSION...THE UPPER HIGH SHOULD BE
OUT OF THE PICTURE FOR WESTERN WASHINGTON BY MONDAY...WITH
SOUTHERLY FLOW ALOFT DEVELOPING AS AN UPPER TROUGH APPROACHES THE
PACIFIC NORTHWEST FROM OFFSHORE. MODELS HAVE BEEN INCONSISTENT
WITH REGARD TO WHEN THE FIRST FRONTAL SYSTEM WILL BRING
PRECIPITATION BACK TO THE FORECAST AREA...BUT A WEAK ONE WILL
PROBABLY ARRIVE BY TUESDAY AND POSSIBLY EVEN ON MONDAY. THE COLD
AIR MASS OVER THE LOWLANDS SHOULD MIX OUT FAIRLY QUICKLY AS ALL
THIS OCCURS. A WETTER SYSTEM SHOULD ARRIVE BY WEDNESDAY...AND WET
WEATHER WILL LIKELY CONTINUE THURSDAY. MCDONNAL
&&
.AVIATION...AS THE STRONG UPPER LEVEL RIDGE OVER THE PACIFIC
NORTHWEST THIS MORNING DRIFTS SLOWLY EAST...IT WILL MAINTAIN COOL
DRY NORTHEAST FLOW ALOFT OVER WESTERN WASHINGTON THROUGH THIS
WEEKEND. A WEAK SURFACE RIDGE OVER SOUTHERN BRITISH COLUMBIA WILL
MAINTAIN DRY NORTH TO NORTHEAST LOW LEVEL OFFSHORE.
THE AIR MASS WILL REMAIN DRY AND STABLE THROUGH THE WEEKEND WITH
MINIMAL FOG OR STRATUS IN THE MORNING. MORNING AIR TEMPERATURES WILL
BE NEAR OR BELOW FREEZING SO ISOLATED FREEZING FOG IS POSSIBLE.
KSEA...CLEAR SKIES. SURFACE WIND NORTHERLY 4-8 KT. KAM
&&
.MARINE...A STRONG SURFACE RIDGE OVER SOUTHERN BRITISH COLUMBIA WILL
MAINTAIN LIGHT NORTHEASTERLY FLOW TODAY. THE RIDGE WILL WEAKEN THIS
AFTERNOON WITH LIGHT OFFSHORE FLOW CONTINUING OVER THE INTERIOR
THOUGH THE WEEKEND. ON SUNDAY...AS AN OFFSHORE FRONTAL SYSTEM
APPROACHES THE REGION WINDS OVER THE COASTAL WATERS WILL SHIFT TO
SOUTHERLY AND BEGIN INCREASING.
E WINDS AT THE NEAH BAY BUOY HAVE DROPPED TO 10-12 KT THIS MORNING
AND THE LATEST 06Z CANADIAN LAM...00Z ARW...AND 15Z HRRR KEEP THE
WINDS BELOW SCA LEVELS THE REST OF TODAY...SO THE SCA FOR THE WEST
ENTRANCE AND COASTAL ZONE 150 WILL BE ENDED.
MODELS HAVE BEEN DOING THEIR TYPICAL WIGGLE-WAGGLE IN THE DAY 3-5
PERIOD AND HAVE SPED UP THE TIMING OF THE NEXT FRONTAL SYSTEM BACK
TO SOMETIME ON MONDAY. WINDS OVER THE COASTAL WATERS WILL SHIFT TO
SOUTHERLY ON SUNDAY AND BEGIN INCREASING AHEAD OF THE APPROACHING
FRONT. SUBSEQUENT FRONTAL SYSTEMS ARRIVING MIDWEEK AND LATER WILL
LIKELY BE STRONGER WITH POTENTIAL FOR GALES AT SOME POINT.
THE CURRENT PERIOD OF KING TIDES WILL HAVE THE HIGHEST TIDES THIS
YEAR. FORTUNATELY STRONG HIGH PRESSURE OVER THE AREA AND RELATIVELY
LIGHT WINDS APPEAR LIKELY TO KEEP THE TIDAL ANOMALIES MINIMAL. NO
COASTAL FLOODING IS FORECAST DURING THE HIGH TIDES. KAM
&&
.HYDROLOGY...FLOODING IS NOT EXPECTED FOR THE NEXT SEVEN DAYS.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...AIR STAGNATION ADVISORY UNTIL NOON PST MONDAY FOR ADMIRALTY
INLET AREA-BELLEVUE AND VICINITY-BREMERTON AND VICINITY-
EAST PUGET SOUND LOWLANDS-EASTERN STRAIT OF JUAN DE FUCA-
EVERETT AND VICINITY-HOOD CANAL AREA-LOWER CHEHALIS VALLEY
AREA-SAN JUAN COUNTY-SEATTLE AND VICINITY-SOUTHWEST
INTERIOR-TACOMA AREA-WESTERN SKAGIT COUNTY-WESTERN STRAIT
OF JUAN DE FUCA-WESTERN WHATCOM COUNTY.
PZ...NONE.
&&
$$
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