Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/14/16
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
128 PM PST FRI FEB 12 2016
.SYNOPSIS...
FAIR AND VERY WARM WEATHER AGAIN TODAY...WITH TEMPERATURES LOWERING
A FEW DEGREES ON SATURDAY AS THE RIDGE OF HIGH PRESSURE WEAKENS.
ANOTHER WARM-UP EXPECTED SUNDAY THROUGH TUESDAY AS THE RIDGE ALOFT
RE-BUILDS AND STRONGER OFFSHORE FLOW MOVES IN. LOCALLY STRONG AND
GUSTY NORTHEAST TO EAST WINDS POSSIBLE IN THE PASSES...CANYONS AND
COASTAL FOOTHILLS SUNDAY THROUGH TUESDAY...WITH STRONGEST WINDS ON
MONDAY. BY NEXT WEDNESDAY...THE RIDGE WILL WEAKEN AND ONSHORE FLOW
RETURNS...RESULTING IN DECREASING TEMPERATURES. A LOW PRESSURE
TROUGH WILL CONTINUE TO COOLING TREND AND MAY BRING SOME SHOWERS TO
THE REGION ON THURSDAY.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AFTERNOON VISIBLE SATELLITE SHOWS A LARGE AREA OF FOG OVER THE
OFFSHORE WATERS NEAR SAN CLEMENTE ISLAND...WITH THIN HIGH CLOUDS TO
THE NORTHWEST. LOOKING AT THE 12Z MIRAMAR SOUNDING AND COMPARING TO
YESTERDAYS 12Z SOUNDING...THE ATMOSPHERE HAS COOLED SLIGHTLY UP
THROUGH 600 MB. MEANWHILE...OFFSHORE PRESSURE GRADIENTS CONTINUE TO
WEAKEN...WITH GRADIENTS OF 7.0 MB FROM SAN DIEGO TO TONOPAH AND 7.9
MB FROM SAN DIEGO TO SALT LAKE CITY...WHEREAS THE GRADIENTS WERE
12.9 MB AND 14.4 MB RESPECTIVELY AT THIS TIME YESTERDAY. AS A
RESULT...NORTHEAST TO EAST WIND GUSTS ARE ONLY IN THE 15-20 MPH
RANGE IN THE PASSES/CANYONS AND COASTAL FOOTHILLS. THE WEAKER
OFFSHORE FLOW IS ALLOWING FOR A SEA BREEZE TO BRING MINOR COOLING TO
THE COAST TODAY...WITH SAN DIEGO ONLY SHOWING A TEMPERATURE OF 77
RIGHT NOW...WHEREAS IT WAS 82 AT 1 PM YESTERDAY. HOWEVER...HIGHS
ELSEWHERE WILL STILL BE 10-20 DEGREES...AND LOCALLY 25
DEGREES...ABOVE NORMAL. IN THE INLAND COASTAL AREAS...VALLEYS AND
LOWER DESERTS...EXPECT HIGHS IN THE MID-TO-UPPER 80S...MID-TO-UPPER
70S AT THE BEACHES AND HIGH DESERTS...70S AT THE LOWER MOUNTAIN
SLOPES...AND THE LOW 60S AT THE HIGH ELEVATIONS. WE MAY HAVE A FEW
STATIONS REACHING RECORD HIGHS AGAIN TODAY.
WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL RIDGE OVER SOUTHERN
CALIFORNIA SLOWLY BEING NUDGED EAST...WITH A TROUGH FAR TO THE WEST.
WITH OFFSHORE FLOW CONTINUING TO WEAKEN TONIGHT...IT MAY ALLOW FOR
SOME DENSE FOG TO REACH THE COASTAL AREAS UP TO A FEW MILES INLAND
LATE TONIGHT INTO SATURDAY MORNING. IN FACT...THE 19Z HRRR SEEMS TO
HAVE INITIALIZED THE AREA OF FOG OFFSHORE PRETTY WELL...AND HAS
DENSE FOG MOVING INTO THE COAST BY MID-EVENING. A TROUGH MOVING
INLAND OVER THE PACIFIC NORTHWEST SATURDAY WILL CREATE SOME COOLING
FOR SATURDAY...BUT TEMPERATURES WILL STILL BE WELL ABOVE NORMAL.
SUNDAY INTO TUESDAY...RIDGING TO THE WEST WILL BUILD BACK OVER THE
REGION. THIS...IN ADDITION TO STRENGTHENING OFFSHORE FLOW RESULTING
FROM STRONG SURFACE HIGH PRESSURE OVER THE GREAT BASIN...WILL CREATE
ANOTHER WARM-UP...WITH HIGHS ONCE AGAIN REACHING 10-20 DEGREES...AND
LOCALLY 25 DEGREES...ABOVE NORMAL. MONDAY AND TUESDAY LOOK LIKE THE
WARMEST DAYS...WITH DAILY HIGH TEMPERATURE RECORDS AT A FEW TO
SEVERAL STATIONS POSSIBLY GETTING BROKEN. MODELS INDICATE THAT THE
OFFSHORE PRESSURE GRADIENTS FROM SAN DIEGO TO TONOPAH STRENGTHEN TO
ABOUT 7-10 MB SUNDAY...AND THEN 11-16 MB MONDAY. MEANWHILE...UPPER
SUPPORT INCREASES AS WELL...WITH 850 MB WINDS OUT OF THE NORTHEAST
REACHING ABOUT 10-20 KT ON SUNDAY...AND THEN 15-30 KT ON MONDAY.
THUS...LOOK FOR WEAK TO LOCALLY MODERATE SANTA ANA WINDS ON
SUNDAY...WITH NORTHEAST TO EAST WIND GUSTS OF 25-40 MPH IN THE
PASSES/CANYONS AND COASTAL FOOTHILLS...AND THEN WINDS STRENGTHENING
FURTHER MONDAY...WITH NORTHEAST TO EAST WIND GUSTS REACHING 40-50
MPH AND LOCALLY 60 MPH IN THE PASSES/CANYONS AND COASTAL FOOTHILLS.
OFFSHORE FLOW WEAKENS A LITTLE ON TUESDAY.
THE RIDGE STARTS TO WEAKEN AND WE TURN BACK ONSHORE DURING THE DAY
WEDNESDAY AS A TROUGH APPROACHES THE WEST COAST...CREATING COOLER
CONDITIONS. THE LONG-RANGE MODELS ARE STILL IN A FAIR AMOUNT OF
DISAGREEMENT REGARDING HOW DEEP AND STRONG THE TROUGH WILL BE AS IT
MOVES INLAND ON THURSDAY. THE 12Z GFS IS PRETTY SIMILAR TO THE 06Z
RUN...SHOWING A WEAK TROUGH AND ASSOCIATED PRECIPITATION MOVING BY
TO OUR NORTH...LEAVING US MOSTLY DRY. HOWEVER...THE 12Z ECMWF IS
MUCH STRONGER...WETTER AND SLOWER FOR SOUTHERN CALIFORNIA. THE 12Z
CANADIAN SEEMS TO SHOW COMPROMISE BETWEEN THE ECMWF AND GFS.
CONSIDERING THAT 2 OF THE 3 LONG RANGE MODELS CONSISTENTLY SHOW
PRECIP FOR THURSDAY...HAVE INCREASED THE POPS A BIT. AT THE VERY
LEAST...EXPECT THE COOLING TREND TO CONTINUE INTO THURSDAY.
&&
.AVIATION...
122100Z...FEW-SCT CLOUDS AOA 20000 FT MSL AND UNRESTRICTED VIS
THROUGH SATURDAY. THERE IS A CHANCE OF LOW CLOUDS AND FOG WITH VIS
2SM OR LESS JUST REACHING THE COAST LATE TONIGHT INTO SATURDAY
MORNING...POSSIBLY VCNTY KSAN/KCRQ/KSNA. CONFIDENCE IS SLIGHTLY
HIGHER AT THIS TIME FOR FOG OCCURRENCE DUE TO NEW HI-RES MODEL
GUIDANCE. WILL STICK WITH VCFG FOR COASTAL TAF SITES FOR NOW
THOUGH...BUT MAYBE A FEW MORE LOW CLOUDS.
&&
.MARINE...
100 PM...FOG WITH VISIBILITY 1SM OR LESS IS LIKELY OVER THE COASTAL
WATERS AND APPROACHING THE COAST TONIGHT THROUGH SATURDAY MORNING.
OTHERWISE NO HAZARDOUS MARINE WEATHER IS EXPECTED SATURDAY AFTERNOON
THROUGH TUESDAY.
&&
.BEACHES...
100 PM...A LONG-PERIOD SWELL FROM 290 DEGREES WILL BUILD
TODAY...PEAKING SATURDAY AT 9 FT/18 SEC. THIS WILL GENERATE HIGH
SURF OF 4 TO 8 FEET TODAY THROUGH SUNDAY WITH HIGHEST SETS NORTH OF
NEWPORT BEACH AND SOUTH OF DEL MAR. A HIGH SURF ADVISORY REMAINS IN
EFFECT FROM 10 AM TODAY THROUGH 8 PM SUNDAY. SWELL AND SURF WILL
SUBSIDE MONDAY.
&&
.FIRE WEATHER...
LIGHT OFFSHORE WINDS WILL CONTINUE THROUGH SATURDAY...THEN OFFSHORE
WINDS STRENGTHEN A LITTLE SUNDAY...WITH NORTHEAST TO EAST GUSTS 25-
40 MPH IN THE PASSES/CANYONS AND COASTAL FOOTHILLS...AND THEN
STRENGTHEN FURTHER ON MONDAY...WITH NORTHEAST TO EAST GUSTS 40-50
MPH AND LOCALLY 60 MPH IN THE PASSES/CANYONS AND COASTAL FOOTHILLS.
THE OFFSHORE FLOW WILL COMBINE WITH VERY WARM CONDITIONS AND MINIMUM
RELATIVE HUMIDITIES IN THE SINGLE DIGITS TO TEENS TO CREATE ELEVATED
TO POSSIBLY CRITICAL FIRE WEATHER CONCERNS ON MONDAY. OVERNIGHT
HUMIDITY RECOVERIES LOOK TO BE POOR TO LOCALLY MODERATE.
HUMIDITY WILL START TO INCREASE WEDNESDAY AS ONSHORE FLOW RETURNS
AND A TROUGH APPROACHES FROM THE PACIFIC. THIS TROUGH COULD PRODUCE
WETTING RAINS NEXT THURSDAY.
&&
.SKYWARN...
SKYWARN ACTIVATION WILL NOT BE NEEDED TODAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY UNTIL 8 PM PST SUNDAY FOR ORANGE COUNTY
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
PZ...NONE.
&&
$$
PUBLIC/FIRE WEATHER...HARRISON
AVIATION/MARINE/BEACHES...TS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
400 PM EST FRI FEB 12 2016
.SYNOPSIS...
AN ARCTIC FRONT WILL CROSS THE AREA TONIGHT. HIGH PRESSURE WILL
BUILD ACROSS THE AREA LATER THIS WEEKEND AND THEN MOVE EAST
SUNDAY NIGHT. LOW PRESSURE WILL DEEPEN ACROSS THE LOWER MISSISSIPPI
VALLEY MONDAY AND THEN MOVE ALONG THE APPALACHIANS TUESDAY AND THEN
NORTH INTO CANADA WEDNESDAY. MORE HIGH PRESSURE WILL BUILD IN FOR
THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
FLURRIES POSSIBLE POCONOS AND EXTREME SOUTH EDGE OF OUR AREA LATE
THIS DAY AS PER RADAR AND OBS.
TONIGHT...SHALLOW MOIST ADVECTION ON S-SW FLOW PRIOR TO THE CFP.
SNOW SHOWERS OR FLURRIES APPEAR PROBABLE FOR A FEW HOURS NEAR
MIDNIGHT AS PER A BLEND OF MODELS AND WPC. HRRR AND HRRX LOOK
ACCEPTABLE AS A TIMING GUIDE. SW WIND MAY GUST 15 MPH EARLY
TONIGHT. THEN A WIND SHIFT TO NORTHWEST AND GUSTY 20-30 MPH BY
DAWN SATURDAY....POSSIBLE ISOLATED GUSTS 40-45 MPH AT SUNRISE PER
ARRIVING STRONG CAA AND PRES RISES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
WIND CHILL ADVY AND WIND ADVY POSTED IN ADDITION TO PRIOR WIND
CHILL WARNING. SPS FROM YDY NO LONGER NEEDED.
DEEPENING BOUNDARY LAYER MOMENTUM TRANSFER IS FEATURED ASSOCIATED
WITH THE ONCOMING ARCTIC AIRMASS INVASION. LARGE LOW LVL LAPSE
RATES AND BTV SNOW SQUALL PARAMETER INDICATING A POSSIBILITY OF
FLURRIES OR SQUALLS BUT WILL THE SFC TT/TD SPREAD EXCEED 25F AND
MAKE THOSE SQUALLS JUST VIRGA? SEEMS LIKE BEST CHC FOR A SQUALL
WOULD BE THE MORNING AND IN THE REGION S OF THE PA TURNPIKE.
AM THINKING OF GUSTS 50 MPH IN THE POCONOS AND ALSO SCATTERED 50
MPH GUSTS DEVELOPING IN THE KRDG-KPHL-KILG KACY AND NORTH SIDE OF
DE BAY SLOT FOR THE AFTN. WIND ADVY ISSUED. NOT SURE HOW MANY
NOTICED BUT THE NAM AND OP ECMWF HAVE BEEN A LITTLE CONSERVATIVE
ON WIND. JUST LOOKS LIKE TOO DEEP A MIXED LAYER TO AVOID CONNECTING
A FEW EDDIES OF 50 KT GUSTS DOWN FROM 6000 TO 7000 FT ALOFT. THE
INVERSION SINKS TO NEAR 850 MB LATE IN THE DAY SATURDAY.
STRONGEST WINDS ASIDE FROM THE INITIAL BURST NEAR 11-12Z, MAY BE
LATE AFTN AND EVENING. FOR NOW WANTED TO LIMIT ADVY ONLY TO THE
DAY AND IF ITS GUSTING 40 KT AT 3 PM SATURDAY, THEN SUSPECT IT CAN
GUST 40-45 KT THROUGH 10 PM. CONFIDENCE ON VERIFICATION IS
AVERAGE. THIS COULD BE OVERDONE BUT HAVE SEEN REPEATEDLY THE POCS
WIND MATCH THE OVERWATER WIND NEAR 44065, AND NW FLOW STRONGEST
GUSTS NEAR A RDG-PHL LINE. ALSO ADDED MD E SHORE ALONG THE STILL
WARM CHES BAY AND DELAWARE ALONG THE BAY FROM WILMINGTON TO LEWES
WHERE I THINK SOME HEFTY GUSTS COULD ADD TO THE CHILL.
OTHERWISE WIDESPREAD GUSTS 40 MPH SATURDAY WITH PARTLY TO MOSTLY
SUNNY SKIES .. TENDING TO CLEAR LATE DAY.
WINDS WERE DERIVED FROM THE GFS, THE TEMPS FROM THE NAM MOS BLENDED
WITH THE 2M TEMPS OF THE 12Z GFS/NAM. HRRX INDICATED NEAR 0 AT KMPO
AT 17Z SATURDAY...WITHOUT A WIND CHILL. CANT SEE IT MORE THAN 17F
AT PHL AT 18Z SAT...MAYBE EVEN A DEGREE OR 2 COLDER?.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THE HEART OF THE ARCTIC AIR MASS WILL BE ACROSS THE AREA SATURDAY
NIGHT AND INTO SUNDAY. DANGEROUSLY COLD TEMPERATURES AND WIND CHILL
READINGS WILL BE ACROSS THE ENTIRE FORECAST AREA. NO PRECIPITATION
IS EXPECTED. WINDS WILL DIMINISH THROUGH THE DAY SUNDAY. LOW
TEMPERATURES SAT NIGHT AROUND -10 ACROSS THE FAR NORTH AND CLOSER TO
5 DEGREES ACROSS THE METRO PHILLY AREAS AND OVER THE DELMARVA. HIGH
TEMPS SUNDAY IN THE TEENS MOST AREAS...BUT SINGLE DIGITS OVER THE
SRN POCONOS. WIND CHILL READINGS -20 TO -32 FAR NORTH AND -5 TO -10
OVER THE DELMARVA.
THE NEXT STORM SYSTEM WILL DEEPEN ACROSS THE SOUTH MONDAY AND MOVE
UP THE INLAND EAST COAST TUESDAY/WEDNESDAY. THE TRACK OF THE SYSTEM
THAT SEEMS TO BE COMING INTO BETTER AGREEMENT AMONGST THE OP MODELS
FAVOR A LOW TRACK ACROSS THE CENTRAL/WESTERN PART OF OUR AREA. THIS
WILL ALLOW A DECENT FLOW OF WARMER AIR TO OVERSPREAD THE REGION. THE
PRECIPITATION WILL BEGIN ACROSS THE AREA MONDAY AS SNOW...BUT WILL
CHANGE TO RAIN LATER MON NIGHT AND REMAIN MOSTLY RAIN TUESDAY. THE
QPF COULD BE UP TO 2 INCHES OF RAIN IN MANY AREAS. THERE IS ALSO
SOME CHC FOR AN ACCUMULATING SNOW MONDAY ACROSS (MOST LIKELY)
ERN/NERN PA BEFORE THE CHANGE TO RAIN. EARLIEST PREDICTIONS FOR SNOW
ACCUMS WOULD BE AROUND 1-3 INCHES AT THIS POINT. THE DETAILS WILL BE
TUNED UP AS THE WEEKEND PROGRESSES.
THE STORM MOVES UP INTO CANADA WEDNESDAY AND WILL BE FOLLOWED BY HIGH
PRESSURE AND DRIER COOLER AIR FOR THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THIS EVENING...VFR CONDITIONS WILL CONTINUE WITH LIGHT SOUTH TO
SOUTHWEST WINDS ACROSS THE TERMINALS.
TONIGHT THROUGH EARLY SATURDAY MORNING...A COLD FRONT WILL APPROACH
THE REGION FROM THE WEST. AN AREA OF SNOW SHOWERS LOOKS TO DEVELOP
IN ADVANCE OF THE FRONTAL PASSAGE AND SNOW SHOWERS ARE EXPECTED TO
REACH ALL TERMINALS. VISIBILITIES AND CEILINGS ARE EXPECTED TO DROP
TO MVFR CONDITIONS AS THE SNOW SHOWERS MOVE THROUGH. ONCE THE
SHOWERS CLEAR THE REGION, BETWEEN 05-09Z FROM WEST TO EAST, A RETURN
TO VFR CONDITIONS IS ANTICIPATED. SNOW SHOWERS MAY DISSIPATE BEFORE
FULLY REACHING KACY AND KMIV BUT LATEST GUIDANCE LEADS US TO INCLUDE
THE SNOW SHOWERS FOR LATE TONIGHT/EARLY SATURDAY.
SATURDAY...THE BIGGEST ISSUE AFFECTING AVIATION TRAVEL ON SATURDAY
WILL BE THE WINDS. BEHIND THE AFOREMENTIONED COLD FRONT, THE WINDS
WILL QUICKLY TURN TO THE WEST THEN NORTHWEST AND BECOME VERY GUSTY.
SUSTAINED WINDS WILL BE AROUND 15-20 KNOTS BY 12-15Z AND INCREASE
INTO THE AFTERNOON. WIND GUSTS FROM 25 KNOTS EARLY WILL INCREASE TO
NEAR 40 KNOTS BY THE AFTERNOON.
OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED. NORTHWEST
WINDS 10 TO 25 KNOTS WITH GUSTS 30-35 KNOTS EARLY, DIMINISHING
SOME OVERNIGHT INTO SUNDAY. GUSTS STILL 20-25 KNOTS OVERNIGHT INTO
EARLY SUNDAY.
MONDAY-MONDAY NIGHT...DEGRADING CONDITIONS WITH MVFR/IFR LIKELY
THROUGH THE DAY MONDAY INTO MONDAY NIGHT. SNOW POSSIBLY
BEGINNING MONDAY FOR MANY AREAS, POSSIBLY MIXING WITH RAIN AT
TIMES FOR SOME AREAS.
TUESDAY-TUESDAY NIGHT...WIDESPREAD MVFR/IFR CONDITIONS. WINDY.
WEDNESDAY...IMPROVING CONDITIONS. WINDY.
&&
.MARINE...
LULL IN THE WIND AND SEAS WILL END SHORTLY AFTER MIDNIGHT.
GALES AND FREEZING SPRAY WARNINGS-ADVISORIES POSTED. THE HEAVIEST
FREEZING SPRAY WILL BE MIDNIGHT TO 7 AM ALONG THE SHORE WHERE SSTS
NOW DOWN TO ABOUT 35-36F AND USED 35 FOR THE ZY THRESHOLD.
ISOLATED 50 KT GUSTS POSSIBLE SATURDAY IN FUNNELED NW WIND DOWN DE
BAY.
OUTLOOK...
SATURDAY-SATURDAY NIGHT...GALE WARNING CONTINUES WITH STRONG
NORTHWEST FLOW ACROSS THE AREA. FREEZING SPRAY ADVISORY REMAINS IN
EFFECT AS VERY COLD AIR AND STRONG WINDS WILL LEAD TO AT LEAST
MODERATE FREEZING SPRAY.
SUNDAY-SUNDAY NIGHT...GALE WARNING AND FREEZING SPRAY ADVISORY
CONTINUE INTO SUNDAY MORNING. HOWEVER, WINDS WILL DIMINISH THROUGH
THE DAY AND SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA.
MONDAY...SUB-SCA CONDITIONS.
MONDAY NIGHT-WEDNESDAY...SMALL CRAFT ADVISORY CONDITIONS
LIKELY...GALES POSSIBLE AS STRONG LOW PRESSURE MOVES UP THE EAST
COAST.
&&
.HYDROLOGY...
BEFORE EVERYONE HEADS INTO THE WEEKEND, I WANTED TO BRING NEXT
WEEK`S STORM INTO LIGHT AND MENTION THAT THERE IS A POTENTIAL FOR
FLOODING ACROSS THE HSA. THERE`S STILL A LOT THAT NEEDS TO UNFOLD,
BUT THE 5-DAY WPC QPF OF 1.50 TO 2.50 INCHES OF LIQUID COMBINED WITH
ANOTHER 0.25 TO 0.50 INCH OF SWE ON THE GROUND WOULD VERY LIKELY
CAUSE NUISANCE LOW-LYING FLOODING AND POSSIBLY SOME MINOR TO
MODERATE RIVER FLOODING (RIVERS ASSOCIATED WITH OUR FORECAST
POINTS). THIS ASSUMES MOST, IF NOT ALL, THE PRECIPITATION FALLS AS
RAIN.
THE UNCERTAINTY THIS AFTERNOON IS LARGE. YESTERDAY AT THIS TIME, THE
PRECIPITATION WAS HEAVIEST TUESDAY AND TUESDAY NIGHT. NOW IT`S LATE
MONDAY NIGHT INTO TUESDAY. BESIDES TIMING, TRACK IS QUITE DIFFERENT
BETWEEN THE GFS AND EURO WITH THE EURO BEING FURTHER WEST AND MORE
LIQUIDY. TRACK WILL PLAY A ROLE IN TEMPS AND NOT ONLY AFFECT WHAT
TYPE OF PRECIPITATION FALLS, BUT ALSO AFFECT WHAT REMAINING SWE
MELTS. THERE`S ABOUT 0.25 TO 0.50 SCATTERED ACROSS THE AREA. I CAN
SAY WE ARE IN A BETTER SPOT THAN ON THE 3RD AND 4TH WHEN THERE WAS
IN EXCESS OF 2.00 OF SWE ALONG THE I-78 CORRIDOR. AS AN FYI, ONE OF
THE MAIN REASONS WE DIDN`T SEE THE FLOODING, THAT MODELS SUGGESTED,
ON THE 3RD AND 4TH WAS BECAUSE ALL THE SWE DID NOT RAPIDLY COME OUT
OF THE SNOWPACK. SNOWMELT CAN BE A TOUGH NUT TO CRACK.
WHILE THE LACK OF SWE IS LOOKING BETTER ACROSS THE HSA, NOT ALL THE
RIVERS HAVE RECEDED BACK TO WHERE THEY WERE PRIOR TO THE 3RD. SO
RIVERS WILL START HIGHER AND THE COLD THIS WEEKEND WILL SURELY GET
THE GROUND HARD FOR A VERY EFFICIENT RUNOFF.
SO THE TAKE AWAY HEADING INTO THE WEEKEND IS TO UNDERSTAND THAT IF
THE MONDAY INTO TUESDAY (OR TUESDAY INTO WEDNESDAY) EVENT IS ALL
LIQUID ACROSS THE AREA, LOW-LYING, POOR DRAINAGE FLOODING IS LIKELY
AND MINOR TO MODERATE RIVER FLOODING IS POSSIBLE. IF THE
PRECIPITATION STARTS OFF AS SNOW OR ICE, THE FLOODING THREAT
DECREASES. IF ALL SNOW FALLS, WE`RE POTENTIALLY JUST KICKING THE CAN
DOWN THE ROAD FOR FUTURE FLOODING. TIME WILL TELL.
&&
.CLIMATE...
NEAR RECORD COLD IS STILL EXPECTED FOR PORTIONS OF OUR AREA SUNDAY
MORNING, DESPITE THE MOS GUIDANCE...AND BY FAR THE COLDEST AIR OF
THE SEASON SO FAR.
BEST CHANCE FOR RECORD EQUALING OR EXCEEDING FOR VALENTINES DAY:
KABE, KTTN, KPHL AND KMPO.
RECORD LOW MAX`S CAN ONLY OCCUR FOR THIS EVENT ON SUNDAY THE 14TH,
IF THEN. THOSE HAVE BEEN ADDED RECENTLY BELOW.
SITE 2015-16 COLDEST SO FAR RECORD LOW FEB. 14TH ----RER LOW MAX
---------------------- --------------------
ABE 8 -1 IN 1979 14-1979
ACY 10 -6 IN 1979 13-1979
PHL 12 +2 IN 1979 14-1979
ILG 12 -4 IN 1979 13-1979
RDG 10 -4 IN 1983
TTN 9 0 IN 1916
GED 13 -7 IN 1979
MPO -1 -12 IN 1970
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND CHILL ADVISORY FROM 6 PM SATURDAY TO 9 AM EST SUNDAY FOR
PAZ060>062-070-071-101>106.
WIND ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR PAZ054-055-
060-061-070-071-101>106.
WIND CHILL WARNING FROM 6 AM SATURDAY TO 1 PM EST SUNDAY FOR
PAZ054-055.
NJ...WIND CHILL ADVISORY FROM 6 PM SATURDAY TO 9 AM EST SUNDAY FOR
NJZ007>010-012>027.
WIND ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR NJZ001-014-
016>027.
WIND CHILL WARNING FROM 6 AM SATURDAY TO 1 PM EST SUNDAY FOR
NJZ001.
DE...WIND CHILL ADVISORY FROM 6 PM SATURDAY TO 9 AM EST SUNDAY FOR
DEZ001-002.
WIND ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR DEZ001>004.
MD...WIND CHILL ADVISORY FROM 6 PM SATURDAY TO 9 AM EST SUNDAY FOR
MDZ008-012.
WIND ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR MDZ008-012-
015-020.
MARINE...HEAVY FREEZING SPRAY WARNING FROM MIDNIGHT SATURDAY NIGHT TO 9
AM EST SUNDAY FOR ANZ450>453.
GALE WARNING FROM 4 AM SATURDAY TO 10 AM EST SUNDAY FOR ANZ430-
431-450>455.
FREEZING SPRAY ADVISORY FROM 4 AM SATURDAY TO 10 AM EST SUNDAY
FOR ANZ430-431-454-455.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...DRAG 4P
SHORT TERM...DRAG 4P
LONG TERM...O`HARA
AVIATION...DRAG/O`HARA 4P
MARINE...DRAG/O`HARA 4P
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
255 PM CST FRI FEB 12 2016
.SHORT TERM...(Tonight)
ISSUED AT 255 PM CST FRI FEB 12 2016
A weak clipper system will exit southeast of central IL late this
afternooon, with its diminishing area of very light snow/flurries se
of the IL river ending soon, with best light snow chances east of IL
over central IN. MVFR clouds already scattering nw of the IL river
like at PIA and HRRR model handling this clearing well. These clouds
to decrease se of the IL river during late afternoon/early evening,
and over southeast IL by mid evening. Brisk NW winds of 15-25 mph
and gusts to 30 mph will gradually diminish during the night,
reaching 5-15 mph later tonight. Strong 1046 mb polar high pressure
west of Lake Winnipeg Canada to settle se into MN/IA by sunrise Sat
and bring a frigid night to the region. Lows by early Saturday
morning range from around zero north of I-72 to 4-8F in southeast IL
from I-70 southeast. Wind chills by dawn will range from 5-15 below
zero with a few spots from I-74 north dipping to 15-17 below zero
like at Bloomington, Galesburg and Champaign. Will hold off on a
wind chill advisory overnight into mid Sat morning, but will issue
SPS to address these bitter cold wind chills especially in our
northern CWA.
&&
.LONG TERM...(Saturday through Friday)
ISSUED AT 255 PM CST FRI FEB 12 2016
Very cold conditions expected to start the day Saturday across
central and southeast Illinois as Arctic high pressure builds across
the area. The relatively slight pressure gradient that will
accompany the surface high should keep Wind Chill values warmer than
advisory criteria for the most part, but high temperatures should
only top out in the teens.
Beyond the initially cold conditions, our attention turns to an
approaching clipper system, which is likely to be the most
significant weather system to impact the area over the next week.
This clipper has trended faster in recent model runs, with snow now
expected to start breaking locally after midnight Saturday
night/Sunday morning. The system will be pushing into a very dry
airmass which should limit the snow accumulation to some degree.
However, fairly strong isentropic ascent and mixing ratios of 2-3
G/KG over at least a 12 hour period should be able to produce 2"=4"
snow totals. In fact, would not be surprised if we need to boost
accumulations further once the exact track of the system is more
clear (it has trended s bit south in the latest runs). One other
thing that will need to be monitored is that the moisture depth is
progged to be rather shallow during the period of potential snow.
This fact is also a reason to limit snow accumulations for now, and
we also need to monitor the threat for freezing drizzle due to a
potential lack of ice crystals.
The faster trend of the clipper system should now have Monday ending
up dry. Another weak clipper system may impact the area Tuesday into
Tuesday night, but it does not appear significant at this time.
After that, the next chance for precipitation should not occur
before the end of the week. However, model agreement in the details
of the late week system is weak at best. Temperatures should
gradually be trending warmer next week, with well above normal
temperatures likely by the end of the week (near 50 degrees for
highs). If these trends hold, the late week system, if/when it
impacts the area, should be a rain producer.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1155 AM CST FRI FEB 12 2016
A weak clipper system was bringing a band of light snow and
flurries that was progessing se of the IL river and approaching
I-72 at midday. The light snow was bringing vsbys down to 1-3
miles for 1-2 hours at PIA and will affect BMI and CMI next few
hours and possibly briefly bring MVFR vsbys to DEC early this
afternoon. MVFR ceilings are expected to scattered out from nw to
se late this afternoon and early evening. Brisk NW winds of 13-18
kts and gusts of 18-25 kts into this evening will diminish to
around 10 kts by overnight and down to 5-9 kts late tonight into
Saturday morning. 1046 mb arctic high pressure west of Lake
Winnipeg Canada will settle into eastern IA by 18Z/noon Sat as it
weakens a bit to 1041 mb. This will provide the fair weather
tonight into Sat with winds diminishing as high pressure settles
in.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...BAK
AVIATION...07
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1134 PM CST THU FEB 11 2016
.UPDATE...
ISSUED AT 908 PM CST THU FEB 11 2016
Light snow is just now beginning to move into western parts of
central Illinois, even though radar indicates it should already
be occurring. Observations show very few lower clouds so if any
light snow is occurring out there, it is flurries and the
observational sites are not picking it up yet. Still thinking that
some light snow will occur in the southwestern parts of the CWA
overnight, so believe current forecast still looks good for the
remainder of the night. May make some tweaks to overnight low
temps in the southeast, but remainder of the area, current
forecast looks fine. Update out shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 323 PM CST THU FEB 11 2016
A fast moving clipper will produce light snow starting this evening
across western Illinois, with most of the focused lift overnight
primarily remaining across our southwestern counties. The general
trend in the 12z models has been to focus the better chances of
measurable snowfall over our southwestern and southern counties.
Have increased PoPs to likely in a narrow corridor southwest of a
line from Jacksonville to Effingham, progressing from SW to SE with
time overnight. The HRRR is the farthest southwest with the latest
updated path of forcing for precip, with the NAM80, Canadian GEM,
and ECMWF still extending at least some snow accumulation across all
of our CWA except the far NE counties NE of CMI. The NAM12 is
similar to the HRRR in limiting snow to the SW half of our CWA. Have
reduced the PoPs in our N and NE counties, north of I-74, to slight
chance. Chance PoPs were limited to generally south of a line from
Galesburg to Lincoln to Paris. Snow amounts from Jacksonville to
Effingham could reach between a half inch and one inch, with a
dusting to a half inch as far north as Rushville to Lincoln to
Decatur. South to southwest winds should remain less than 10 mph
during the snowfall, so drifting should not be a big problem
overnight.
Low temps tonight will generally settle out in the mid-teens, as
cloud cover limits the diurnal swing to only around a 10 degree drop-
off.
.LONG TERM...(Friday through Thursday)
ISSUED AT 323 PM CST THU FEB 11 2016
Friday may start out with a few lingering snow showers south of
I-70, but little additional accumulation is expected after
sunrise. The bigger story will be the arrival of very cold air on
increasing northwest winds Friday afternoon, as strong pressure
rises develop ahead of the surface high center. The tight pressure
gradient will produce wind gusts over 30 mph at times, which could
cause minor drifting of the snowfall from tonight, so slippery
travel could develop from that Friday afternoon and evening.
Wind chills late Friday night will drop very close to advisory
levels of -15F north of Peoria, with wind chills below zero in all
of our forecast area. Actual air temps will be range from zero to 8
above zero, but NW winds will remain strong enough to push wind
chills well below zero.
The next main concern will be the system for Sunday into Monday.
Model differences remain with the 12z model updates. The Canadian
GEM has started showing the splitting of energy as the trough
reaches Illinois, similar to what the ECMWF was showing yesterday.
The ECMWF has changed and now maintains the trough energy across
Illinois Sunday evening, with total QPF amounts that support snow
amounts of 1 to 2". The Canadian GEM QPF amounts support around 1
inch west of I-55, with little to no snow accum east of I-55. The
GFS remains the only model that develops a distinct surface
low/circulation that tracks across northern IL Sunday evening, with
total QPF amounts that support snowfall of 4" to 7" in our northern
counties, and 3-4" in the south. The 12z NAM now includes forecast
info through 6 pm Sunday, and is showing plenty of snow as well,
despite no surface low moving across IL. The NAM has 3-5" across our
counties for just the first 12 hours of the event through 6 pm
Sunday. We have increased PoPs into the likely category for Sunday
nearly everywhere, and likely PoPs east of I-57 Sunday night.
Our compromise forecast for QPF came out to 0.23-0.30", correlating
to snowfall amounts of 2-4", with the higher totals from Peoria and
north. There still remains quite a bit of uncertainty with how much
moisture will fall, so updates to QPF and resultant snow accums are
likely with subsequent model runs.
The accumulating snows should primarily be done by Monday morning,
but lingering light snow or flurries could continue into afternoon.
If precip does linger into the afternoon, the snow may mix
with or change to rain.
All of the extended models show a low deepening south of Illinois on
Monday, and progressing up into the Appalachian mountains Monday
night, with precip mainly southeast of our area. However, the
blended initialization kept slight chance PoPs in the eastern half
of Illinois Monday night through Tuesday night, mainly due to that
strong system.
A warming trend is indicated for next week, as upper level ridging
gradually pushes east into Illinois. We should see mid-level warming
increase enough to support high temps climbing into the upper 30s to
low 40s Tuesday and Wed, with sunshine and mid 40s to around 50 for
Thursday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1134 PM CST THU FEB 11 2016
Snow has not begun at any of the TAF sites yet, but with mosaic
radar loop showing most of the snow still west of the area and
nothing being reported under the higher returns on radar, thinking
is that flurries will occur at most of the TAF sites overnight,
with SPI only site getting light snow overnight for a few hours
from 07z to 09z. Vis at SPI during the light snow will be 3sm
while remainder of the time, think vis will be VFR. Do not see
cigs dropping to MVFR levels until after the snow has ended over
the area, due to very dry lower layers...seen on 00z UA sounding
and any snow currently falling is just moistening up the lower
layer. MVFR cigs at 2.5kft will occur from early morning til
afternoon in the west and later afternoon in the east. Then clouds
will scatter out and last til evening. Winds will be light out of
the southwest to start, but then become westerly and then
northwesterly for the afternoon and evening. Light wind speeds til
after winds shift to west and northwest. Then speeds increase and
become gusty with gusts of 23-38kts possible.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...Shimon
LONG TERM...Shimon
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
316 AM EST FRI FEB 12 2016
.UPDATE...
THE LONG TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 330 PM EST THU FEB 11 2016
A COLD UPPER TROUGH OVER ONTARIO AND THE ST. LAWRENCE VALLEY WILL KEEP US
UNDER A NORTHWEST FLOW ALOFT AND TEMPERATURES COLDER THAN NORMAL THROUGH
EARLY NEXT WEEK. A CLIPPER WILL GIVE US A CHANCE OF LIGHT SNOW TOWARDS
DAYBREAK OVER WESTERN SECTIONS AND MOST AREAS FRIDAY. LAKE EFFECT
SNOW SHOWERS MAY LINGER TO MIDDAY SATURDAY ACROSS OUR NORTHEAST.
COLD HIGH PRESSURE WILL BUILD EAST ACROSS OUR REGION SATURDAY AND
SATURDAY NIGHT. AN APPROACHING AREA OF LOW PRESSURE WILL SPREAD
SNOW ACROSS OUR REGION SUNDAY INTO MONDAY. ANOTHER SYSTEM WILL
BRING A CHANCE OF SNOW MONDAY AND MONDAY NIGHT. FINALLY A FOURTH
SYSTEM WILL BRING A CHANCE OF SNOW OR MIXED PRECIPITATION AROUND THE
MIDDLE OF NEXT WEEK. TEMPERATURES WILL BETENTIALGIN TO MODERATE
TOWARDS THE MIDDLE OF NEXT WEEK AS OUR UPPER FLOW BECOMES MORE
ZONAL.
&&
.NEAR TERM.../TONIGHT AND FRIDAY/
ISSUED AT 822 PM EST THU FEB 11 2016
GOING FORECAST IS IN EXCELLENT SHAPE. FLAKES MAY FLY ACROSS PORTIONS
OF CENTRAL INDIANA BY THE MORNING RUSH. FEEL CHANCE POPS HANDLE THIS
BEST HOWEVER AS THERE IS A LOT OF NEAR SURFACE DRY AIR TO OVERCOME.
WILL HAVE TO MONITOR FOR POSSIBLE IMPACTS TO FRIDAY MORNING COMMUTE
ACROSS THE AREA...ESPECIALLY AS HRRR AND NAM PROFILES INDICATE FIRST
FLAKES MAY BEGIN REACHING THE GROUND DURING THE HEART OF THE
COMMUTE. HOWEVER...RATES APPEAR UNLIKELY TO BE SUCH THAT RAPID
ACCUMULATION WOULD OCCUR...WHICH WOULD LIMIT POTENTIAL IMPACT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 330 PM EST THU FEB 11 2016
HIGH PRESSURE CENTERED OVER ILLINOIS WILL MOVE EAST ACROSS INDIANA THIS
EVENING AND ON TO THE EAST BY MONDAY. A WEAK CLIPPER OVER THE UPPER
MIDWEST AND NORTHERN PLAINS WILL MOVE TO THE MIDDLE MISSISSIPPI VALLEY
LATE TONIGHT AND ACROSS THE OHIO VALLEY FRIDAY.
MOSTLY CLEAR CONDITIONS WERE OCCURRING ACROSS WESTERN SECTIONS THIS AFTERNOON
WHILE PARTLY CLOUDY CONDITIONS WERE THE RULE IN THE EAST. MID/HIGH CLOUDS
OVER THE MIDDLE MISSISSIPPI VALLEY WILL MOVE OUR WAY AND THICKEN OVERNIGHT.
ANY SNOW FROM THE CLIPPER PROBABLY WON`T REACH OUR AREA UNTIL AFTER 09Z AND
THIS WILL BE MAINLY ACROSS WESTERN AND SOUTHWEST AREAS.
SCATTERED LIGHT SNOW SHOWERS WILL SPREAD EAST ACROSS OUR REGION FRIDAY. AMOUNTS
WILL BE GENERALLY A QUARTER INCH. BUT SOME LAKE EFFECT SNOW SHOWERS ARE POSSIBLE
ACROSS OUR NORTHEAST LATE FRIDAY AS OUR FLOW BECOMES MORE NORTHERLY AND AMOUNTS
THERE WILL BE A LITTLE HIGHER BY LATE FRIDAY.
LOWERED TEMPERATURES SLIGHTLY CENTRAL AND EAST TONIGHT AS HIGH PRESSURE WILL
PROVIDE GOOD RADIATIONAL COOLING EARLY ON. OTHERWISE...A MOS BLEND OF TEMPERATURES
SEEM REASONABLE. WINDS WILL BE LIGHT TONIGHT AND THEN BECOME NORTHWEST WITH
GUSTS UP TO 25 MPH BY FRIDAY AFTERNOON AS A PRESSURE GRADIENT STRENGTHENS.
&&
.SHORT TERM.../FRIDAY NIGHT THROUGH SUNDAY/
ISSUED AT 330 PM EST THU FEB 11 2016
WE WILL REMAIN UNDER A COLD NORTHWEST FLOW FRIDAY NIGHT SATURDAY AS HIGH
PRESSURE OVER THE NORTHERN PLAINS BUILDS OUR WAY. MODELS INDICATE SOME FETCH OFF
OF LAKE MICHIGAN WHICH WILL PRODUCE SCATTERED LAKE EFFECT SNOW SHOWERS OVER
NORTHEAST SECTIONS. WHILE COLD AND DRY WEATHER WILL BE THE RULE ELSEWHERE.
MODELS INDICATE 850 TEMPERATURES OF -15 TO -21 CELSIUS SATURDAY AND -8 TO -12
CELSIUS SUNDAY. THIS WILL TRANSLATE TO HIGHS IN THE TEENS SATURDAY 20 TO 26
DEGREES SUNDAY. LOWS WILL BE MOSTLY IN THE SINGLE DIGITS BOTH FRIDAY AND
SATURDAY NIGHT. BUT LOWS NEAR ZERO ARE POSSIBLE SATURDAY NIGHT OVER NORTHEAST
SECTIONS AS CLOUDS MAY NOT ARRIVE THERE UNTIL LATE.
THE BIGGEST CONCERN WILL BE SNOW AMOUNTS SUNDAY AS AREA OF LOW PRESSURE MOVES
INTO THE UPPER MIDWEST AND A STRONGER CLIPPER MOVES OUR WAY. THE NAM/OPERATIONAL
GFS AND THE NEW EURO ALL INDICATE AN INCH OR TWO OF SNOW BY SUNDAY AFTERNOON...
WHILE THE CANADIAN HARDLY HAS ANYTHING AS MOST OF ITS PRECIPITATION IS FARTHER
SOUTHWEST. FOR NOW WILL GO WITH A BLEND. WILL RAISE POPS TO LIKELY OVER WEST
CENTRAL AND NORTHWEST AND GO WITH HIGH CHANCE POPS ELSEWHERE BY SUNDAY AFTERNOON.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 316 AM EST FRI FEB 12 2016
A LOT OF MOVING PARTS IN REGARDS TO THE EARLY WEEK SYSTEM POISED
TO AFFECT THE EASTERN U S AND THE 00Z MODEL SUITE DID LITTLE TO
INCREASE THE LOW CONFIDENCE IN HIGHLIGHTING SPECIFIC IMPACTS TO
CENTRAL INDIANA. THE EXTENDED PERIOD WILL BE ACTIVE WITH VARIOUS
SNOW THREATS THROUGH MIDWEEK BEFORE A WARMING TREND COMMENCES FOR
THE SECOND HALF OF THE WEEK.
NORTHERN STREAM CLIPPER SYSTEM WILL SWING THROUGH THE LOWER GREAT
LAKES LATE SUNDAY AND EARLY MONDAY AND WILL PRESENT CHANCES FOR
SNOW. AT THE SAME TIME...LOW PRESSURE ORGANIZING OVER THE LOWER
MISSISSIPPI VALLEY WILL TRACK NORTHEAST INTO THE LOWER APPALACHIANS
BY TUESDAY. ADDITIONALLY...OP GFS AND ECMWF BOTH TRACK ANOTHER
CLIPPER INTO THE MID MISSISSIPPI VALLEY. THE 00Z RUNS OF THE
OPERATIONAL MODELS ARE TRACKING THE MAIN SYSTEM EAST OF THE
APPALACHIANS AND ARE SUGGESTIVE OF LESS OF AN IMPACT TO THE REGION
WITH NO PHASING WITH THE CLIPPER TO THE NORTHWEST. GFS ENSEMBLE
MEMBERS ON THE OTHER HAND ARE ALL OVER THE PLACE WITH THE SURFACE
LOW TRACK DUE TO VARYING DEGREES OF PHASING IN THE UPPER LEVELS.
FURTHER MUDDYING THE WATERS IS THE MARGINAL TEMPS IN THE NEAR
SURFACE LAYER WHICH ARGUES FOR EVEN THE POSSIBILITY FOR OTHER PRECIP
TYPES TO MIX IN WITH SNOW FOR A TIME ON MONDAY AND TUESDAY.
THE UPPER LEVEL FLOW AND TELECONNECTION PATTERN SUGGESTS
POTENTIAL IS THERE FOR SOME SHIFT NORTH AND WEST TO THE MAIN
SYSTEM. WITH THE PRIMARY UPPER WAVE STILL OUT OVER THE PACIFIC AND
NOT FULLY SAMPLED YET...FUTURE MODEL RUNS TODAY AND SATURDAY WILL
BE CRITICAL IN DETERMINING IF THE MAIN STORM SHIFTS LEFT AND
PRESENTS A GREATER IMPACT TO PARTS OF THE FORECAST AREA FOR EARLY
WEEK. AT THIS TIME HOWEVER...ATTEMPTING TO EMPLOY ANY DETAIL
INCLUDING POTENTIAL SNOWFALL AMOUNTS IS POINTLESS. WILL CARRY
CHANCES OF SNOW MONDAY AND TUESDAY WITH A POSSIBILITY FOR RAIN TO
MIX IN ACROSS THE SOUTH TUESDAY AS CRITICAL LOW LEVEL THICKNESSES
WARM.
HIGH PRESSURE WILL BRING DRIER WEATHER TO THE REGION BY
MIDWEEK...WITH EXPANDING RIDGING ALOFT AND STRONG SOUTHERLY FLOW
PROVIDING A NICE WARMUP BY THE END OF THE WEEK AS TEMPERATURES GO
ABOVE NORMAL.
&&
.AVIATION /DISCUSSION FOR THE 120900Z TAF UPDATE/...
ISSUED AT 316 AM EST FRI FEB 12 2016
LITTLE CHANGE NEEDED FOR THE EARLY MORNING UPDATE. SEEING AREA OF SNOW
SHOWERS IMPACT CENTRAL ILLINOIS AS THEY MOVE SOUTHEAST. ANY
IMPACTS AGAIN LOOK PRIMARILY FOCUSED ON THE KBMG AND KHUF
TERMINALS THROUGH MID MORNING.
06Z DISCUSSION FOLLOWS.
UPPER DISTURBANCE CURRENTLY DROPPING SOUTHEAST THROUGH NORTHERN MISSOURI
IS EXPECTED TO SETTLE INTO WESTERN KENTUCKY AROUND SUNRISE FRIDAY. COULD
BE SOME LIGHT SNOW AT THE TERMINALS ROUGHLY 121000Z-121600Z ASSOCIATED WITH
THIS FEATURE...MAINLY IN THE KHUF/KBMG AREAS...BUT IT APPEARS ANY
IFR VISIBILITY RESTRICTIONS WILL REMAIN SOUTHWEST OF THE TERMINALS
CLOSER TO VORTICITY CENTER.
OTHERWISE...EXPECTING CEILINGS TO GRADUALLY LOWER OVERNIGHT AND INTO THE
MORNING HOURS ON FRIDAY...EVENTUALLY FALLING INTO THE MVFR CATEGORY TOWARDS
MIDDAY FRIDAY AS COLD ADVECTION DEVELOPS IN THE WAKE OF THE DISTURBANCE.
LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 260-280 DEGREES AT 10-13 KTS
BY MIDDAY FRIDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$TENTIAL
SYNOPSIS...JH
NEAR TERM...JH/NIELD
SHORT TERM...JH
LONG TERM....RYAN
AVIATION...JAS/RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1138 PM EST THU FEB 11 2016
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 330 PM EST THU FEB 11 2016
A COLD UPPER TROUGH OVER ONTARIO AND THE ST. LAWRENCE VALLEY WILL KEEP US
UNDER A NORTHWEST FLOW ALOFT AND TEMPERATURES COLDER THAN NORMAL THROUGH
EARLY NEXT WEEK. A CLIPPER WILL GIVE US A CHANCE OF LIGHT SNOW TOWARDS
DAYBREAK OVER WESTERN SECTIONS AND MOST AREAS FRIDAY. LAKE EFFECT
SNOW SHOWERS MAY LINGER TO MIDDAY SATURDAY ACROSS OUR NORTHEAST.
COLD HIGH PRESSURE WILL BUILD EAST ACROSS OUR REGION SATURDAY AND
SATURDAY NIGHT. AN APPROACHING AREA OF LOW PRESSURE WILL SPREAD
SNOW ACROSS OUR REGION SUNDAY INTO MONDAY. ANOTHER SYSTEM WILL
BRING A CHANCE OF SNOW MONDAY AND MONDAY NIGHT. FINALLY A FOURTH
SYSTEM WILL BRING A CHANCE OF SNOW OR MIXED PRECIPITATION AROUND THE
MIDDLE OF NEXT WEEK. TEMPERATURES WILL BEGIN TO MODERATE TOWARDS THE
MIDDLE OF NEXT WEEK AS OUR UPPER FLOW BECOMES MORE ZONAL.
&&
.NEAR TERM.../TONIGHT AND FRIDAY/
ISSUED AT 822 PM EST THU FEB 11 2016
GOING FORECAST IS IN EXCELLENT SHAPE. FLAKES MAY FLY ACROSS PORTIONS
OF CENTRAL INDIANA BY THE MORNING RUSH. FEEL CHANCE POPS HANDLE THIS
BEST HOWEVER AS THERE IS A LOT OF NEAR SURFACE DRY AIR TO OVERCOME.
WILL HAVE TO MONITOR FOR POSSIBLE IMPACTS TO FRIDAY MORNING COMMUTE
ACROSS THE AREA...ESPECIALLY AS HRRR AND NAM PROFILES INDICATE FIRST
FLAKES MAY BEGIN REACHING THE GROUND DURING THE HEART OF THE
COMMUTE. HOWEVER...RATES APPEAR UNLIKELY TO BE SUCH THAT RAPID
ACCUMULATION WOULD OCCUR...WHICH WOULD LIMIT POTENTIAL IMPACT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 330 PM EST THU FEB 11 2016
HIGH PRESSURE CENTERED OVER ILLINOIS WILL MOVE EAST ACROSS INDIANA THIS
EVENING AND ON TO THE EAST BY MONDAY. A WEAK CLIPPER OVER THE UPPER
MIDWEST AND NORTHERN PLAINS WILL MOVE TO THE MIDDLE MISSISSIPPI VALLEY
LATE TONIGHT AND ACROSS THE OHIO VALLEY FRIDAY.
MOSTLY CLEAR CONDITIONS WERE OCCURRING ACROSS WESTERN SECTIONS THIS AFTERNOON
WHILE PARTLY CLOUDY CONDITIONS WERE THE RULE IN THE EAST. MID/HIGH CLOUDS
OVER THE MIDDLE MISSISSIPPI VALLEY WILL MOVE OUR WAY AND THICKEN OVERNIGHT.
ANY SNOW FROM THE CLIPPER PROBABLY WON`T REACH OUR AREA UNTIL AFTER 09Z AND
THIS WILL BE MAINLY ACROSS WESTERN AND SOUTHWEST AREAS.
SCATTERED LIGHT SNOW SHOWERS WILL SPREAD EAST ACROSS OUR REGION FRIDAY. AMOUNTS
WILL BE GENERALLY A QUARTER INCH. BUT SOME LAKE EFFECT SNOW SHOWERS ARE POSSIBLE
ACROSS OUR NORTHEAST LATE FRIDAY AS OUR FLOW BECOMES MORE NORTHERLY AND AMOUNTS
THERE WILL BE A LITTLE HIGHER BY LATE FRIDAY.
LOWERED TEMPERATURES SLIGHTLY CENTRAL AND EAST TONIGHT AS HIGH PRESSURE WILL
PROVIDE GOOD RADIATIONAL COOLING EARLY ON. OTHERWISE...A MOS BLEND OF TEMPERATURES
SEEM REASONABLE. WINDS WILL BE LIGHT TONIGHT AND THEN BECOME NORTHWEST WITH
GUSTS UP TO 25 MPH BY FRIDAY AFTERNOON AS A PRESSURE GRADIENT STRENGTHENS.
&&
.SHORT TERM.../FRIDAY NIGHT THROUGH SUNDAY/
ISSUED AT 330 PM EST THU FEB 11 2016
WE WILL REMAIN UNDER A COLD NORTHWEST FLOW FRIDAY NIGHT SATURDAY AS HIGH
PRESSURE OVER THE NORTHERN PLAINS BUILDS OUR WAY. MODELS INDICATE SOME FETCH OFF
OF LAKE MICHIGAN WHICH WILL PRODUCE SCATTERED LAKE EFFECT SNOW SHOWERS OVER
NORTHEAST SECTIONS. WHILE COLD AND DRY WEATHER WILL BE THE RULE ELSEWHERE.
MODELS INDICATE 850 TEMPERATURES OF -15 TO -21 CELSIUS SATURDAY AND -8 TO -12
CELSIUS SUNDAY. THIS WILL TRANSLATE TO HIGHS IN THE TEENS SATURDAY 20 TO 26
DEGREES SUNDAY. LOWS WILL BE MOSTLY IN THE SINGLE DIGITS BOTH FRIDAY AND
SATURDAY NIGHT. BUT LOWS NEAR ZERO ARE POSSIBLE SATURDAY NIGHT OVER NORTHEAST
SECTIONS AS CLOUDS MAY NOT ARRIVE THERE UNTIL LATE.
THE BIGGEST CONCERN WILL BE SNOW AMOUNTS SUNDAY AS AREA OF LOW PRESSURE MOVES
INTO THE UPPER MIDWEST AND A STRONGER CLIPPER MOVES OUR WAY. THE NAM/OPERATIONAL
GFS AND THE NEW EURO ALL INDICATE AN INCH OR TWO OF SNOW BY SUNDAY AFTERNOON...
WHILE THE CANADIAN HARDLY HAS ANYTHING AS MOST OF ITS PRECIPITATION IS FARTHER
SOUTHWEST. FOR NOW WILL GO WITH A BLEND. WILL RAISE POPS TO LIKELY OVER WEST
CENTRAL AND NORTHWEST AND GO WITH HIGH CHANCE POPS ELSEWHERE BY SUNDAY AFTERNOON.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 237 PM EST FEB 11 2016
AN ACTIVE WEATHER PATTERN IS IN PLACE FOR THE LONG TERM. MODEL
VARIABILITY WITH THIS SYSTEM HAS BEEN AND CONTINUES TO BE FAIRLY
HIGH...AS DESCRIBED FURTHER BELOW. ESSENTIALLY AN UPPER WAVE WILL
MOVE SOMEWHERE THROUGH THE GREAT LAKES WITH AN ASSOCIATED SURFACE
SYSTEM SOMEWHERE TO ITS SOUTH AND THIS WILL BRING SNOW CHANCES TO
THE AREA. HOW MUCH SNOW AND WHERE IS STILL VERY MUCH IN QUESTION.
GFS ENSEMBLE MEMBERS ARE CLUSTERING MORE WITH THE HIGHER AMOUNTS
OVER NORTHERN INDIANA WITH A FEW MEMBERS PUTTING THE MAX ACROSS
THE CENTRAL PART OF THE STATE. 24 HOUR MAX AMOUNTS IN THE GEFS
VARY FROM 2 INCHES TO AROUND 6 INCHES. THE 12Z OPERATIONAL GFS HAS
A MAX OF AROUND 4+ INCHES ACROSS THE NORTHERN THIRD OF THE STATE
WITH 2-3 INCH AMOUNTS CENTRAL AND SHARPLY LESS SOUTH. THE 12Z
ECMWF THOUGH SHOWS SNOWFALL MAXES TO THE NORTH AND SOUTH WITH THE
IND CWA IN A LOCAL MINIMUM WITH AROUND 1-1.5 INCHES OR LESS. ECM
RUNS HAVE BEEN BOUNCING FROM A SOLUTION WITH A MAX WELL SOUTH OF
THE FORECAST AREA TO HIGHEST AMOUNTS ACROSS THE SOUTHERN COUNTIES.
0Z CANADIAN ENSEMBLE AVERAGE FAVORS THE SOLUTION THAT PUTS THE MAX
WELL SOUTH OF THE AREA. 0Z GFS CIPS ANALOGS SHOW THE HIGHEST
PROBABILITY FOR 2 INCHES OR GREATER IS ACROSS THE NORTHERNMOST
COUNTIES OF THE FORECAST AREA AND PROBABILITIES TAPER OFF HEADING
SOUTH.
FORECAST MODELS ARE FAIRLY CONSISTENT IN SHOWING DECENT
FORCING DURING THE SUNDAY NIGHT PERIOD SO WILL INCREASE POPS TO
LIKELY DURING THAT TIME. AT THIS MOMENT THOUGH WILL NOT CHANGE
SNOWFALL AMOUNTS FROM THOSE GIVEN BY THE BLENDED INITIALIZATION.
SNOW CHANCES STAY AROUND FOR MONDAY THROUGH TUESDAY IN CYCLONIC
FLOW. SHOULD SEE A SLOW WARMING TREND THROUGH THE WEEK WITH SMALL
CHANCES FOR RAIN OR SNOW TUESDAY AND WEDNESDAY.
&&
.AVIATION /DISCUSSION FOR THE 120600Z TAFS/...
ISSUED AT 1138 PM EST THU FEB 11 2016
UPPER DISTURBANCE CURRENTLY DROPPING SOUTHEAST THROUGH NORTHERN MISSOURI
IS EXPECTED TO SETTLE INTO WESTERN KENTUCKY AROUND SUNRISE FRIDAY. COULD
BE SOME LIGHT SNOW AT THE TERMINALS ROUGHLY 121000Z-121600Z ASSOCIATED WITH
THIS FEATURE...MAAINLY IN THE KHUF/KBMG AREAS...BUT IT APPEARS ANY IFR
VISIBILITY RESTRICTIONS WILL REMAIN SOUTHWEST OF THE TERMINALS CLOSER TO
VORTICITY CENTER.
OTHERWISE...EXPECTING CEILINGS TO GRADUALLY LOWER OVERNIGHT AND INTO THE
MORNING HOURS ON FRIDAY...EVENTUALLY FALLING INTO THE MVFR CATEGORY TOWARDS
MIDDAY FRIDAY AS COLD ADVECTION DEVELOPS IN THE WAKE OF THE DISTURBANCE.
LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 260-280 DEGREES AT 10-13 KTS
BY MIDDAY FRIDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/NIELD
SHORT TERM...JH
LONG TERM...CP
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1143 PM CST THU FEB 11 2016
...AVIATION UPDATE...
.UPDATE...
ISSUED AT 803 PM CST THU FEB 11 2016
NARROW BAND OF MOSTLY LIGHT SNOW HAS SET UP FROM JUST SW OF DMX
SE THROUGH CENTERVILLE AND OTTUMWA S-SE TO NEAR QUINCY IL AS SEEN
ON AREA RADARS. IN THE DVN FORECAST AREA...SNOW HAD BEGUN OVER
THE PAST HOUR IN FAIRFIELD WITH UPSTREAM VISIBILITIES AROUND 2 1/2
TO 3SM IN ADJACENT S CENTRAL IA . THE LATEST HRRR...RAP AND NAM
HIGH RES MODELS KEEP THIS AXIS OF LIGHT SNOW...CONFINED TO SE
IA...NE MO INTO W CENTRAL IL...MAINLY NORTH OF HIGHWAY 34. THIS IS
THE AXIS OF MAIN UPPER LEVEL FORCING...WHICH IS NUDGED UP AGAINST
A DEEP DRY AIRMASS TO THE NORTHEAST. SURFACE DEWPOINTS OVER
EASTERN IA AND POINTS EAST AND NORTH WERE ONLY IN THE SINGLE
DIGITS...AND THE KDVN 00Z/12 SOUNDING INDICATED A DEEP DRY LAYER
BELOW 700 MB.
THIS WILL LIKELY KEEP MEASURABLE SNOW LIMITED TO SE IA...FAR NW MO
AND W CENTRAL IL OVER THE NEXT SEVERAL HOURS AND HAVE BACKED DOWN
ON SNOW AMOUNTS OVER THE CENTRAL AND NORTH FOR OVERNIGHT TO TRACE
AMOUNTS AT BEST. WILL HAVE TO WATCH A WEAK AREA OF LIFT THE NW
FLOW ALOFT PRODUCING LIGHT SNOW IN THE MSP AREA FOR MUCH LATER
TONIGHT AS IT PROGRESSES TOWARD FAR EASTERN IA AND NW IL. WILL
HANDLE THIS WITH VERY LOW POPS AND KEEP A MENTION OF AT LEAST
FLURRIES IN ALL AREAS THROUGH THE OVERNIGHT.
&&
.SYNOPSIS...
ISSUED AT 327 PM CST THU FEB 11 2016
HIGH PRESSURE CENTERED OVER THE EASTERN CWA THIS AFTERNOON AS
LEADING TO CLEAR SKIES AND DRY WEATHER FOR MOST OF THE AREA. A
FAST MOVING CLIPPER IS FORECAST TO AFFECT THE AREA LATER TODAY AND
TONIGHT AND WILL BE THE MAIN FORECAST CONCERN IN THE SHORT TERM
FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 327 PM CST THU FEB 11 2016
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES FOR SNOW
ASSOCIATED WITH A FAST CLIPPER ACROSS THE AREA TODAY. DRY AIR IN
PLACE WITH THE HIGH OVERHEAD WILL LIMIT OVERALL SNOWFALL TOTALS TO
AROUND AN INCH...WITH LOCALLY HIGHER AMOUNTS JUST OVER AN INCH.
HIRES GUIDANCE IS IN GOOD AGREEMENT THAT THIS WILL START NEAR 00Z
AND BE OUT OF THE AREA BY 08Z.
GUIDANCE TODAY HELD STRONG WITH THE CONSENSUS ON TIMING AND
STRONGEST FORCING WILL REMAIN ACROSS OUR FAR SOUTHERN ZONES. WWD
HAS AROUND AN INCH OF SNOW FOR THIS AREA AND OUR FORECAST
REPRESENTS THIS. LATEST RUNS OF THE HRRR SUGGESTS THAT THE BEST
SNOW WILL BE OUT OF THE AREA BY 06Z WITH LINGERING FLURRIES
THROUGH 09Z ACROSS THE FAR SOUTHERN CWA. WINDS WILL REMAIN LIGHT
SO LITTLE TO NO IMPACTS ARE EXPECTED FROM THIS SNOW. ANY SNOW THAT
ACCUMULATES SHOULD BE DONE BY THE EARLY HOURS.
FRIDAY WILL BE QUIET AND SLIGHTLY WARMER..WITH CLEARING SKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 327 PM CST THU FEB 11 2016
FRIDAY NIGHT...LATEST SUITE OF 12Z RUN MODELS SUGGEST 1045 MB ARCTIC
HIGH PRESSURE STILL ON TRACK TO SURGE DOWN THE UPPER TO MID MS
RIVER VALLEY FRI NIGHT INTO SAT WITH A SCOURING EFFECT. THIS
FEATURE TO COLD DUMP LLVL TEMPS/THICKNESS VALUES TO PRODUCE SUB-
ZERO LOWS ACRS MOST OF THE CWA...BUT SOME CONCERN THAT ONGOING
MIXING SFC WINDS IN INCOMING HIGH PRESSURE GRADIENT TO LIMIT A
COMPLETE BOTTOM OUT. BUT DUE TO BRUTE FORCE COLD AIR
ADVECTION...WILL STILL GO WITH LOWS FROM 5 TO NEAR 10 BELOW ZERO
ACRS THE NORTHWESTERN THIRD OF THE CWA...0 TO 5 BELOW ALONG AND
NORTH OF I80...AND TO THE LOW SINGLE DIGITS ABOVE ZERO IN THE
SOUTHERN CWA. SFC WINDS DECREASING TO 7-10 MPH TOWARD SUNRISE SAT
STILL TO PRODUCE ADVISORY LEVEL WIND CHILLS ACRS AT LEAST THE
NORTHWESTERN THIRD OF THE DVN CWA...AND POSSIBLY ALONG THE HWY 20
CORRIDOR IN NW IL.
SATURDAY AND SUNDAY...THE ARCTIC HIGH OVERHEAD WILL MAKE FOR
TEMPORARY CLEAR AND CALM/LIGHT WIND CONDITIONS FOR FIRST PART OF THE
DAY SAT...WITH HIGH CLOUDS ON THE INCREASE AS THE AFTERNOON
PROGRESSES. THIS AHEAD OF THE ORGANIZING SHORT WAVE UPPER TROF THAT
WILL LOOK TO PROPAGATE TOWARD THE SOUTHWESTERN GRT LKS AND MID MS
RIVER VALLEY ON SUNDAY IN BROADENING WEST-NORTHWESTERLY STEERING
FLOW. THE VARIOUS MEDIUM RANGE SOLUTIONS SUGGEST SOME TYPE OF
ASSOCIATED WARM AIR ADVECTION WING OF SNOW WILL LOOK TO TRY TO GET
INTO THE WESTERN OR SOUTHWESTERN CWA BY EARLY SAT EVENING...BUT
FEEL MODELS MAY BE TOO QUICK WITH THIS TAKING INTO ACCOUNT
STRENGTH OF DRY SFC RIDGE AXIS STILL ON THE MOVE OVER AND EAST OF
THE CWA AT THAT TIME. BUT BY MIDNIGHT SAT NIGHT...BOTH THE 12Z RUN
ECMWF AND GEM SUGGEST SOME LIGHT SNOW ACCUMS STARTING TO TAKE
PLACE ALREADY IN THE FAR SOUTHWESTERN CWA. AGAIN SIDING WITH THE
12Z GEM/ECMWF WHICH ARE IN DECENT AGREEMENT...THE WAA WING OF SNOW
AHEAD OF THE MAIN UPPER TROF WILL LOOK TO CONTINUE TO SPREAD
EASTWARD ACRS MUCH OF THE WESTERN 2/3S OF THE CWA THROUGH 12Z
SUNDAY...BUT MAY GET ERODED SOME AS IT DOES BY ONGOING DRY AIR IN
PLACE AND ALSO SOME IMPACT OF MUCH OF THE INITIAL LIFT GOING INTO
THE TOP-DOWN SATURATION PROCESS. THE LATEST GEM MAY HAVE THE BEST
HANDLE ON THIS IDEA WITH JUST A DUSTING TO HALF INCH WEST OF THE
MS RIVER BY 12Z SUNDAY...BUT WILL GO WITH A FEW TENTHS TO NEAR AN
INCH SOUTHWEST OF A LINE FROM DBQ...TO THE QUAD CITIES...AND TO
MACOMB IN WESTERN IL.
THEN THE MAIN SNOW EVENT WITH THE UPPER TROF WILL LOOK TO OCCUR ON
SUNDAY AND WILL CONTINUE TO ADJUST POPS UP INTO LIKELY OR EVEN
CATEGORICAL. BUT THE 12Z RUN AMERICAN MODELS/ESPECIALLY THE 12Z GFS/
WHICH HINT AT HIGH END ADVISORY OR EVEN LOW END WARNING CRITERIA
AMOUNT SNOWS BY SUNDAY EVENING COMBINING THE TWO SNOW MAKING
PROCESSES...SEEM TOO WET...TOO STRONG LOOKING AT MID AND UPPER LEVEL
JET DYNAMICS MORE FAVORABLE TO THE SOUTH...AND THEIR DEEP SATURATION
IN THE DENDRITIC GROWTH ZONE FOR MUCH OF SUNDAY MORNING INTO EARLY
AFTERNOON. SO CURRENTLY FAVOR A BLEND OF THE 12Z GEM/ECMWF MOISTURE
AND FORCING PROFILES WHICH SUGGEST MOST OF THE CWA TO GET 1-3 OR 2-4
INCHES OF SNOW BY SUNDAY EVENING. INCREASING SOUTH WINDS OF 15-20
MPH MAY PRODUCE SOME DRIFTING TROUBLE BY SUNDAY AFTERNOON AS
WELL...SO THERE MAY BE A NEED FOR AN EVENTUAL ADVISORY EVEN WITH THE
LIGHTER AMOUNTS PRODUCED BY THESE FAVORED SOLUTIONS. STILL 1-3 MORE
MODEL RUNS NEEDED TO FURTHER DEFINE THIS SNOW EVENT FOR MORE
CONFIDENCE.
MONDAY THROUGH NEXT THU...AS THE PASSING TROF CONTINUES TO EVOLVE
ALONG AND EAST OF THE REGION EARLY NEXT WEEK..RESULTANT MAJOR STORM
SHOULD TAKE OFF WELL TO THE EAST/SOUTHEAST OF LOCAL AREA OF CONCERN.
BUT THERE MAY BE SOME NUISANCE LIGHT SNOW AT TIMES ACRS THE AREA IN
THE WAKE OF THE MAIN SYSTEM...OR EVEN A SECONDARY WEAK CLIPPER LATE
MONDAY INTO TUE. LONGER RANGE INDICATIONS THEN SUGGEST THE CLIPPER
INDUCING NORTHWESTERLIES WILL EVENTUALLY GIVE WAY TO MILDER UPPER
RIDGING BY MID TO LATE NEXT WEEK...BUT THE TREND HAS BEEN TO DELAY
IT/S ARRIVAL ESPECIALLY IF RE-ENFORCING TROFFINESS ESTABLISHES ACRS
THE WESTERN GRT LKS TUE INTO WED LIKE SOME OF THE LATEST ENSEMBLES
SUGGEST. ..12..
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1143 PM CST THU FEB 11 2016
A WEAK UPPER LEVEL DISTURBANCE DIVING SOUTHEAST OUT OF MN IS
EXPECTED TO BRING ANOTHER ROUND OF LOWERED CIGS AND POTENTIAL
FLURRIES LATER TONIGHT INTO EARLY FRIDAY MORNING. THE LATEST
FORECASTS HAVE A LOW CONFIDENCE PERIOD OF MVFR CIGS...AROUND 2500
FT AGL...CENTERED ON THIS FEATURE. EARLIER ON...LIGHT SNOW
ASSOCIATED WITH A SEPARATE SYSTEM EXITING INTO MO AND IL WILL
AFFECT PRIMARILY THE BRL SITE EARLY...FOLLOWED BY A SEVERAL HOUR
PERIOD OF VFR CONDITIONS AT ALL SITES. ON FRIDAY...AN ARCTIC COLD
FRONT WILL PUSH THROUGH DURING THE MORNING HOURS. THIS WILL BE
FOLLOWED BY BRISK NORTHWEST WINDS AND FALLING TEMPERATURES. THERE
MAY ALSO BE FLURRIES WITH THIS FEATURE...WHICH ARE NOT INCLUDED IN
THE CURRENT FORECASTS. WINDS WILL LIKELY DIMINISH IN THE EVENING
WITH CLEARING SKIES AS ARCTIC HIGH PRESSURE BUILDS INTO THE
REGION.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...12
AVIATION...SHEETS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1125 PM EST THU FEB 11 2016
.UPDATE...
ISSUED AT 1100 PM EST THU FEB 11 2016
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS.
MUCH OF THE 0Z GUIDANCE AND RECENT SHORT TERM MODEL RUNS HAVE
SHIFTED THE AXIS OF HEAVIER SNOW TO THE SOUTH...AND THIS WOULD PUT
THE BEST CHANCE FOR ONE INCH OF ACCUMULATION OR MORE ON FRI
MORNING ALONG THE SOUTHERN TIER OF COUNTIES IN THE CURRENT
ADVISORY. THIS SHOULD AFFECT THE MORNING COMMUTE. HOWEVER...SNOW
SHOWERS ARE ALSO POSSIBLE FURTHER NORTH...POSSIBLY AFFECTING THE
TAIL END OF THE MODEL COMMUTE.
UPDATE ISSUED AT 830 PM EST THU FEB 11 2016
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATIONS.
TIMING OF THE ONSET OF SNOW AND ASSOCIATED POPS HAS BEEN FRESHENED
UP LATE TONIGHT AND EARLY ON FRI BASED ON RECENT MODEL TRENDS.
18Z AND RECENT HRRR RUNS GENERALLY KEEP THE HIGHEST QPF AND BEST
CHANCES FOR MEASURABLE SNOW SOUTH OF THE HAL ROGERS PARKWAY AND KY
80 CORRIDOR. IN THIS AREA...AROUND AN INCH IS ANTICIPATED THROUGH
NOON ON FRIDAY. FURTHER NORTH...LESSER AMOUNTS ARE ANTICIPATED.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 255 PM EST THU FEB 11 2016
19Z SFC ANALYSIS SHOWS AN AREA OF HIGH PRESSURE SLIPPING INTO THE
OHIO VALLEY. TO THE SOUTH AND WEST OF THIS...LOW PRESSURE IS
STARTING TO DEVELOP. ON SATELLITE...SOME LOWER AND MID LEVEL
CLOUDS ARE CLEARING OUT OF THE AREA WHILE THE NEXT ROUND OF
CLOUDS ARE HEADING TOWARD THE AREA FROM THE NORTHWEST. THE PARTIAL
SUNSHINE OF TODAY HELPED TEMPERATURES TO REBOUND INTO THE MID AND
UPPER 20S NORTH AND UPPER 20S TO LOWER 30S IN THE SOUTH.
DEWPOINTS...MEANWHILE...ARE RUNNING IN THE 10 TO 15 DEGREE RANGE
WITH LIGHT WINDS...GENERALLY FROM THE NORTHWEST.
THE MODELS ARE IN GREAT AGREEMENT ALOFT WITH THE EASTERN TROUGH
RETREATING TO THE NORTH TONIGHT. IN THE NORTHWEST FLOW THAT
FOLLOWS FOR KENTUCKY A QUICK HITTING SHORTWAVE WILL PUNCH THROUGH
THE TENNESSEE VALLEY FRIDAY MORNING. THE CORE OF THIS WILL MAINLY
PASS WEST OF EASTERN KENTUCKY...BUT ALSO BRING SOME HEIGHT FALLS
TO THE AREA FOR THE DAY. ANOTHER SHARP TROUGH TO THE NORTH WILL
SWING THROUGH THE GREAT LAKES LATER FRIDAY INTO SATURDAY MORNING
WITH ADDITIONAL STREAMS OF ENERGY BRUSHING THE NORTHEAST PORTION
OF THE STATE. GIVEN THE MODEL AGREEMENT WILL FAVOR A GENERAL
BLEND ALONG WITH A LEAN TOWARD THE HIGHER RESOLUTION NAM12 AND
HRRR.
SENSIBLE WEATHER WILL FEATURE A QUIET AND CHILLY EVENING WITH
LIGHT SNOW DEVELOPING TOWARD DAWN IN THE WEST AND SHORTLY AFTER IN
THE EAST. THE CLIPPER SYSTEM BRINGING THE SNOW WILL TARGET THE
SOUTHERN PORTION OF THE AREA FRIDAY MORNING WITH AROUND AN INCH OF
SNOW EXPECTED. THE SNOW SHOULD TAPER OFF BY NOON FOR MOST OF
EASTERN KENTUCKY...BUT COULD LINGER IN THE FAR NORTHEAST.
ADDITIONAL SNOW SHOWERS WILL BE POSSIBLE IN THE EVENING AND
OVERNIGHT INTO SATURDAY MORNING...WITH ACCUMULATIONS MAINLY
CONFINED TO THE FAR EASTERN PARTS OF THE AREA DUE TO UPSLOPE
FLOW. THIS FIRST BATCH OF SNOW WILL BE ROBUST FOR A FEW HOURS
DURING THE MORNING AND RIGHT THROUGH THE MORNING COMMUTE HOURS.
ON ACCOUNT OF THIS...AND AS IT TARGETS SOME OF THE MAIN
THOROUGHFARES IN OUR CWA...HAVE ISSUED AN ADVISORY FOR OUR
SOUTHERN TIER OVER TO PIKE COUNTY FROM 10Z THROUGH 17Z. AN SPS
WILL BE ISSUED FOR THE REMAINDER OF THE AREA FOR LATE TONIGHT
INTO FRIDAY MORNING. AN ADDITIONAL SPS OR ADVISORY MAY BE NEEDED
FOR LATER FRIDAY INTO EARLY SATURDAY FOR OUR UPSLOPE AREAS. WILL
DETAIL ALL THIS IN THE HWO...AS WELL.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND
GRIDS THROUGH THE NIGHT BEFORE FAVORING THE SUPERBLEND THEREAFTER.
ONLY MADE SOME MINOR ADJUSTMENTS TO THE TEMPS TONIGHT AND FRIDAY
NIGHT DUE TO TERRAIN DIFFERENCES BOTH NIGHTS. AS FOR POPS...WENT
ON THE HIGH SIDE OF MOS GUIDANCE THROUGH THE PERIOD...GENERALLY IN
LINE WITH THE MET TONIGHT/FRIDAY AND MUCH ABOVE FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 359 PM EST THU FEB 11 2016
...ANOTHER WINTER STORM ON TAP FOR EARLY NEXT WEEK...
ARCTIC AIR WILL BE ENTRENCHED OVER THE AREA BY SATURDAY...SETTING
UP A VERY COLD DAY WHERE WE WILL LIKELY EXCEED OUR COLDEST HIGH
TEMPERATURES ON RECORD FOR THE DATE. HIGHS WILL STRUGGLE TO REACH
THE MID TO UPPER TEENS. GIVEN THE COLD AIRMASS AND CONTINUED
NORTHWEST FLOW...SOME FLURRIES/SNOW SHOWERS WILL REMAIN POSSIBLE
THROUGH THE DAY AND EVEN INTO THE EVENING...BUT SHOULD NOT POSE
MUCH OF AN IMPACT TO THE AREA. A COLD NIGHT WILL BE SEEN SATURDAY
NIGHT...WITH SOME RECOVERY IN TEMPERATURES EXPECTED ON SUNDAY.
HOWEVER...MID/HIGH CLOUDS WILL INCREASE AND WE COULD START SEEING
SOME FLURRIES/LIGHT SNOW SHOWERS DURING THE DAY SUNDAY. BY SUNDAY
NIGHT...A WARM FRONT WILL PUSH NORTH ACROSS THE AREA WITH LIGHT
SNOW BREAKING OUT ACROSS THE REGION. THIS LOOKS LIKE IT COULD
PRODUCE A LIGHT COATING OF SNOW ACROSS MOST OF THE AREA INTO EARLY
MONDAY MORNING.
THIS BRINGS US INTO EARLY NEXT WEEK...WHERE CONFIDENCE REMAINS
SOMEWHAT LOW AS MODELS ARE STILL SORTING OUT ALL THE DIFFERENCES.
12Z GFS/ECMWF HAVE TRENDED TOWARD A MORE NORTHERN TRACK OF THE
LOW...WITH MILDER CONDITIONS SPREADING INTO EASTERN KENTUCKY. THIS
MAY SUPPORT A CHANGEOVER TO RAIN ON MONDAY...OR FREEZING RAIN IF
TEMPERATURES IN THE VALLEYS DON`T RECOVER FAST ENOUGH.
HOWEVER...THE TRACK OF THE SYSTEM WILL DETERMINE EXACTLY WHERE
SNOW/FREEZING RAIN/RAIN FALLS...SO UNTIL MODELS COME INTO
AGREEMENT...TRYING TO PIN DOWN DETAILS WILL BE VERY DIFFICULT.
REGARDLESS...THOSE WITH PLANS EARLY NEXT WEEK SHOULD STAY AWARE OF
THE POTENTIAL FOR A WINTER STORM IN THE COMING DAYS AND CHECK BACK
WITH THE FORECAST. AS THIS SYSTEM DEPARTS BY TUESDAY...IT LOOKS
LIKE A WEAK TROUGH DEVELOPS OVER THE AREA AGAIN WITH POTENTIAL
RAIN/SNOW SHOWERS LINGERING INTO MIDWEEK. BY THE END OF THE
WEEK...THE TROUGH EXITS WITH STRONG RIDGING BUILDING BACK INTO THE
AREA. THIS WILL YIELD A MORE SIGNIFICANT WARM UP BY THE END OF
NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 735 PM EST THU FEB 11 2016
MVFR SHOULD PREVAIL THROUGH AT LEAST THE FIRST 9 TO 12Z HOURS OF
THE PERIOD. HOWEVER...CIGS SHOULD THEN LOWER INTO THE MVFR RANGE
TOWARD DAWN AS A CLIPPER SYSTEM BRINGS SOME SNOW TO THE AREA. THIS
SHOULD AFFECT THE FOUR SOUTHERNMOST OF THE TAF SITES. THE BEST
CHANCES FOR LOW VIS AND CIGS WILL BE THROUGH THE SOUTHERN HALF OF
THE CWA PEAKING IN THE 12Z TO 16Z RANGE. WINDS WILL BE RELATIVELY
LIGHT AT 5 TO 10 KT DURING THE PERIOD...GENERALLY FROM THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM TO NOON EST FRIDAY FOR KYZ068-
069-079-080-083>088-110-112>118-120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION
NWS GRAY ME
348 PM EST FRI FEB 12 2016
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL CROSS THE REGION TONIGHT THROUGH SATURDAY
USHERING IN THE COLDEST AIRMASS OF THE SEASON THUS FAR. AS THIS
COLD AIR INTERACTS WITH A TROUGH OF LOW PRESSURE OVER THE GULF OF
MAINE...A PERIOD OF MODERATE TO HEAVY SNOW WILL BE POSSIBLE ALONG
THE MIDCOAST REGION OF MAINE. BEYOND THIS...THE COMBINATION OF COLD
TEMPERATURES AND STRONG NORTHWEST WINDS WILL CAUSE DANGEROUSLY COLD
WIND CHILLS SATURDAY NIGHT AND SUNDAY. TEMPERATURES WILL RAPIDLY
MODERATE NEXT WEEK WITH A WINTRY MIX OF PRECIPITATION POTENTIALLY
TRANSITIONING TO RAIN ON MONDAY NIGHT AND TUESDAY ALONG WITH STRONG
SOUTHERLY WINDS.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
HIGH IMPACT WEATHER POTENTIAL: SNOW DEVELOPS ALONG THE MIDCOAST
OVERNIGHT.
CURRENT PATTERN: EARLY AFTERNOON WATER VAPOR IMAGERY REVEALS RIDGE-
TROUGH PATTERN ACROSS THE CONUS...WITH IMPRESSIVE PORTION OF THE
POLAR VORTEX CURRENTLY CENTERED OVER JAMES BAY. SOUTH OF THIS
FEATURE...WATER VAPOR IMAGERY DEFINES A DIGGING SHORTWAVE /DARKENING
OF THE IMAGERY/ OVER THE NORTHERN OHIO VALLEY. THIS WILL HELP FORCE
CYCLOGENESIS OFF THE MID ATLANTIC COAST THAT WILL RACE NORTHEAST
WELL SOUTH AND EAST OF NEW ENGLAND THROUGH SATURDAY. A WEAKER
SURFACE LOW IS CURRENTLY DEPICTED OVER THE EASTERN GREAT LAKES
ASSOCIATED WITH FORCING AHEAD OF THE H5 LOW OVER JAMES BAY. AS THIS
LATTER FEATURE DIVES SOUTH AND EAST TOWARDS NEW ENGLAND THIS
WEEKEND...THE ASSOCIATED SURFACE LOW WILL BE ABSORBED INTO THE
DEVELOPING SYSTEM OFFSHORE. OUR PRIMARY WEATHER IMPACTS WILL BE
1- WHAT HAPPENS BETWEEN THESE SYSTEMS AS IMPRESSIVE MID AND UPPER
LEVEL FORCING COMBINES WITH VERY SUBSTANTIAL INSTABILITY OVER THE
RELATIVELY WARM GULF OF MAINE WATERS AND 2- THE RAMIFICATIONS OF
ARRIVING ARCTIC AIR. TEMPS AT H8 THIS MORNING WERE -35C OVER JAMES
BAY WITH TEMPERATURES CLOSE TO THIS REACHING NEW ENGLAND ON
SATURDAY...PRESENTING WIND CHILL CONCERNS AS IMPRESSIVE COLD
ADVECTION DRIVES THIS AIR INTO THE REGION.
TONIGHT: EXPECT A GENERAL INCREASE IN MID AND UPPER LEVEL
CLOUDINESS PER A LOOK AT AFTERNOON VISIBLE SATELLITE IMAGERY AS
WEAK WARM ADVECTION CONTINUES AHEAD OF APPROACHING SURFACE LOW NOW
NORTH OF LAKE ONTARIO. FORCING FOR ASCENT WILL BE ON THE INCREASE
WITH TOP DOWN SATURATION LIKELY BRINGING SNOW SHOWER ACTIVITY INTO
THE MOUNTAINS OVERNIGHT. WE/LL TALK MORE ABOUT THE NORLUN EVENT IN
THE SHORT TERM SECTION BELOW...BUT EXPERIMENTAL HRRR IS ON BOARD
WITH THE 12Z GUIDANCE SUITE IN DEVELOPING LLEVEL CONVERGENCE IN THE
VICINITY OF PENOBSCOT BAY BY MIDNIGHT TONIGHT...WITH SNOW DEVELOPING
IN THIS REGION AND CONTINUING THROUGH THE MORNING. WITH A GOOD
FLUFF FACTOR HELPING ACCUMULATIONS...COULD SEE 1-3 INCHES OVER
KNOX/WALDO COUNTIES BY DAYBREAK.
TEMPERATURES: WITH SOUTHWEST FLOW ONGOING AND CLOUDS ON THE
INCREASE...TEMPERATURES WILL BE A GOOD BIT WARMER THAN THE PREVIOUS
NIGHT BUT GIVEN THE CHILLY HIGHS OF TODAY...WILL CERTAINLY NOT BE
WARM. EXPECT LOWS IN THE SINGLE DIGITS IN THE MOUNTAINS THROUGH THE
LOWER TEENS ALONG THE COAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
...SIGNIFICANT SNOW ALONG THE MID COAST BECOMING INCREASINGLY
LIKELY SATURDAY...
...DANGEROUSLY COLD WIND CHILLS SATURDAY NIGHT THROUGHOUT THE
REGION...
HIGH IMPACT WEATHER POTENTIAL: HEAVY SNOW TOTALS POSSIBLE IN THE
VICINITY OF PENOBSCOT BAY SATURDAY WITH ATTENTION THEN TURNING TO
ADVISORY-WARNING LEVEL WIND CHILLS SATURDAY NIGHT.
SATURDAY: CORE OF H5 LOW ALOFT SINKS FROM JAMES BAY AT DAYBREAK
SOUTH AND EAST INTO NORTHERN NEW ENGLAND TOWARDS EVENING WITH T8S
NEARING -30C OVER MY WESTERN ZONES BY 00Z/SUN. COL REGION BETWEEN
LOW LEVEL REFLECTION OF THIS H5 LOW AND THE DEVELOPING SYSTEM WELL
SOUTH AND EAST OF THE BENCHMARK APPEARS TO BE ALLOWING ALL THE
INGREDIENTS FOR A BONA-FIDE NORLUN EVENT TO BE PRESENT AS THE H8
FLOW GOES SLACK ALONG WITH A DEVELOPING LLEVEL CONVERGENCE ZONE.
THERE WILL BE AMPLE INSTABILITY IN THE LLEVELS WITH WATER SURFACE TO
H8 DELTA TS NEAR -15 AND DELTA TS TO H7 NEARING -30C. THIS ALLOWS
FOR A TREMENDOUS AMOUNT OF LLEVEL INSTABILITY...WITH OCEAN-INDUCED
CAPE VALUES OF 500-1000 J/KG PORTRAYED ON THE 12Z NAM AND GFS.
THIS COULD VERY WELL PROMOTE THUNDER WITH ANY SNOW BAND THAT DOES
DEVELOP.
SNOW RATIOS: THE DENDRITIC GROWTH ZONE WILL BE BELOW THE PRIMARY
AREA OF LIFT DURING THE HEIGHT OF THE EVENT...BUT IT WILL STILL GET
CLIPPED AND SEE NO REASON WHY WE CAN/T FORCE 15-20:1 RATIOS OUT OF
THIS SETUP.
THERE IS UNCANNY AGREEMENT IN THE 12Z SUITE /NAM-GFS-ECMWF-GEM/ ON
THE PLACEMENT OF THE MESOSCALE BAND OVER PENOBSCOT BAY. WHILE THIS
WOULD TEND TO SUGGEST ABOVE NORMAL CONFIDENCE...THE FACT THAT THIS
IS A NORLUN EVENT BEGS CAUTION. A LOOK A THE 00Z NCAR ENSEMBLE
SHOWS ABOUT 40% OF THE MEMBERS DIRECTLY IMPACTING OUR AREA. WOULD
REALLY LIKE TO SEE THIS EVENT COME INTO THE NEAR TERM-HIGH
RESOLUTION GUIDANCE WINDOW AND AS SUCH...WITH THE WORD OUT RIGHT NOW
WITH THE WATCH...WILL LET THE EVENING SHIFT TAKE A FINAL LOOK AT
THINGS BEFORE MAKING A FINAL DECISION ON WINTER STORM WARNINGS VS.
WINTER WEATHER ADVISORIES. THAT BEING SAID...CERTAINLY CANNOT RULE
OUT SOME 1 FOOT+ SNOWFALL AMOUNTS SOMEWHERE IN THE MID COAST REGION
GIVEN THE SETUP ABOVE.
TEMPERATURES: MAY RISE SLIGHTLY IN THE EARLY MORNING...BUT WILL
THEN REVERSE COURSE AND FALL THROUGH THE AFTERNOON WITH ALL
LOCATIONS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO BY EVENING. WIND
CHILLS WILL REACH ADVISORY LEVELS IN THE MOUNTAINS IN THE
AFTERNOON...WITH THE MOST DANGEROUS VALUES HOLDING OFF UNTIL
SATURDAY NIGHT. NONETHELESS...WIND CHILLS WILL BECOME
INCREASINGLY DANGEROUS BY LATE AFTERNOON/EVENING.
WINDS: VERY IMPRESSIVE COLD AIR ADVECTION WILL YIELD STEEP LLEVEL
LAPSE RATES...WHICH SHOULD BE ABLE TO MIX ANYTHING THE ATMOSPHERE
HAS TO OFFER WIND-WISE IN THE LOWEST 5KFT. HIGHEST WINDS IN THE
COLUMN ARE AROUND 30KTS /A BIT HIGHER OFFSHORE/ SO WILL PAINT GUSTS
AROUND 30MPH INLAND /HIGHER ON THE HILLTOPS/ AND 30-40MPH ALONG THE
COAST. NOTE: WINDS WILL NOT BE THIS STRONG IN THE VICINITY OF THE
NORLUN TROUGH AND THUS SIGNIFICANT BLOWING/DRIFTING WILL NOT
INITIALLY BE A PROBLEM. HOWEVER...BY SATURDAY EVENING...THERE
WILL LIKELY BE SIGNIFICANT BLOWING/DRIFTING...AND WILL HAVE TO
WATCH FOR THIS IF THE SNOW DOES MATERIALIZE.
SATURDAY NIGHT: H5 LOW OPENS UP AND SHIFTS EAST WITH THE CORE OF THE
COLDEST AIR ALOFT OVERHEAD UNDER CONTINUED STRONG NORTHWEST WINDS AS
GRADIENT BETWEEN 1035 MB HIGH OVER THE GREAT LAKES COMBINES WITH
OFFSHORE-MOVING NORLUN TO CONTINUE WINDS OF 15G25KTS. CONCERNS WILL
TURN TO DANGEROUSLY COLD WIND CHILLS...WHICH SHOULD HAVE NO PROBLEM
HITTING WARNING CRITERIA IN THE MOUNTAINS AND FOOTHILLS...BUT LIKELY
REMAIN AT ADVISORY LEVELS ALONG THE COAST. AM HONESTLY A BIT
SURPRISED IN THE MET/MAV LOW TEMPERATURE SPREAD AS WE SHOULD
REMAIN WELL-MIXED THROUGH THE NIGHT. DID GIVE SOME NOD TO THE
COLDER MET...WITH LOWS BELOW ZERO IN ALL LOCATIONS...AND PERHAPS
AS LOW AS -20 IN THE MOUNTAINS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH IMPACT WEATHER: DANGEROUSLY COLD WIND CHILLS LINGER INTO AT
LEAST SUNDAY MORNING. A STORM COULD BRING SNOW/FREEZING RAIN/RAIN
TO THE REGION MONDAY NIGHT INTO TUESDAY NIGHT. STRONG WINDS ARE
POSSIBLE WITH THIS SYSTEM AS WELL.
DEEP PERSISTENT 500 TROUGH OVER THE ERN CONUS ON SUNDAY WILL SHIFT
NE AND WEAKEN BY EARLY NEXT WEEK...AND THIS ALLOWS THE HEMISPHERIC
WAVE PATTERN TO BECOME LESS AMPLIFIED WITH A HIGHER WAVE NUMBER.
THE OVERALL +PNA PATTERN WEAKENS EARLY TO MID-WEEK...AND TRIES TO
BREAK DOWN BY THE END OF THE WEEK. OF NOTE THOUGH...IS SRN STREAM
WAVE THAT DIGS OVER S CENTRAL CONUS MON AND LIFTS NWD TUE AND WED
AS NRN STREAM DIVES INTO IT AND THIS COULD PRODUCE THE HIGH IMPACT
STORM OVER NEW ENGLAND AROUND TUESDAY.
SUNDAY START IN THE THROES OF THE THE VERY COLD AIR MASS IN THE
REGION WITH STRONG PRES GRAD IN PLACE AND GUSTY NW WINDS. THE
DANGEROUS WIND CHILLS LINGER THRU THE MORNING BUT AS TEMPS WARM
FROM LOWS BELOW ZERO EVERYWHERE...AND WITH PRES GRADIENT
SLACKENING AS SFC HIGH BUILDS IN SHOULD SEE WIND CHILLS RISE TO
MORE BEARABLE LVLS BY AFTERNOON. STILL...THE TAIL OF THE CAA WILL
HOLD THRU MOST OF THE DAY AND HIGHS WILL STRUGGLE TO REACH ZERO IN
THE N...AND TO REACH 10F IN THE SOUTH. AS THE SFC HIGH MOVES OVER
THE REGION LOOK FOR DECOUPLING IN MOST PLACES AND VERY GIVEN GOOD RAD
COOLING GIVEN COLD AIR IN PLACE AND A STARTING POINT NEAR OR BELOW
ZERO. WENT BELOW SUPERBLEND FOR MINS IN MOST PLACES...AND
SIGNIFICANTLY BELOW IN THE MORE SHELTERED SPOTS. THIS SHOULD BRINGUS
LOWS 10 BELOW TO ZERO IN THE COASTAL PLAIN...WITH LOWS DROPPING
TO -20 OR LOWER IN THE SHELTERED MOUNTAIN VALLEYS.
ON MONDAY LOOK FOR WARMER AIR TO START WORKING IN...AND HIGHS
REBOUND INTO THE TEENS TO MID 20S...WITH INCREASING CLOUDS IN THE
AFTERNOON.
THE NEXT SYSTEM MOVES IN ON MON NIGHT AND TUE. SOME DIFFERENCES IN
THE MODEL AS TO HAVE FAR W THE SFC LOW TRACKS...WITH THE GFS AND
GGEM PASSING IT S-N THRU THE MIDDLE OF ME...AND THE EURO AND GEFS
MEAN BRINGING IT NWD ALONG THE NY/VT BORDER...WHICH WOULD BE THE
WARMER SOLN...AND LIKELY LEAD TO SNOW TO FZRA/PL TO RAIN SOLN IN
MANY SPOTS. THE MORE EASTERLY TRACK WOULD SEE SNOW LAST LONGER
INTO THE STORM AWAY FROM THE COAST. P-TYPE WILL BE ONE OF THE BIG
ISSUES WITH THIS SYSTEM AND CONFIDENCE IS LOW AS TO HOW IT WILL
ALL UNFOLD. ONE THING TO NOTE IS THAT WE ARE COMING OUT OF VERY
COLD AIRMASS...AND DESPITE THE BEST WINDS ABOVE THE INVERSION IT
WILL BE SLOW TO BREAK OUT OF THAT LOW LVL COLD AIR...WHICH WILL
PROBABLY HOLD ON LONGER THAN THE MODELS SUGGEST. ANOTHER ISSUE
COULD BE STRONG WINDS...ALTHOUGH WITH THE INVERSION MAY BE TOUGH
FOR THOSE WINDS TO MIX TO THE SFC...AT LEAST FOR ANY SIGNIFICANT
LENGTH OF TIME.
THE WHOLE SYSTEM WILL MOVE OUT LATE TUE NIGHT AND WED. COULD BUST
OUT INTO WARMER AIR ON WED BEHIND THE SYSTEM WITH HIGHS CLIMBING
INTO THE UPPER 30S TO LOW 40S. COLD FRONT SWINGS THRU WED NIGHT
WITH UPPER LVL TROUGH ON THU AND TEMPS DROP BACK AGAIN...BELOW
NORMAL...BUT NOT TOO FAR...WITH HIGHS IN THE 20S TO AROUND 30.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR UNDER MOSTLY CLEAR CONDITIONS ATTM. EXPECT
DETERIORATING CONDITIONS THROUGH THE COMING TAF PERIOD WITH SNOW
DEVELOPING OVERNIGHT AT RKD AND LIKELY AUG WITH IFR/LIFR
RESTRICTIONS. FOR A PERIOD SATURDAY...INCH PER HOUR SNOWFALL RATES
ARE POSSIBLE...MOST LIKELY AT RKD. FURTHER WEST...ARCTIC FRONT
WILL BRING A ROUND OF SNOW SHOWERS...MOST LIKELY TO BRING
RESTRICTIONS TO LEB/HIE...BUT BRIEF RESTRICTIONS ARE POSSIBLE
SOUTH AND EAST OF THIS AS WELL. CONDITIONS IMPROVE SATURDAY NIGHT
WITH VFR CONDITIONS RETURNING FOR SUNDAY.
AFTER LIGHT WINDS OVERNIGHT...STRONG NORTHWEST WINDS /15G25KTS/
WILL DEVELOP BY LATE MORNING SATURDAY AND CONTINUE THROUGH
SATURDAY NIGHT.
LONG TERM...MAINLY VFR SUN THRU MON WITH GUSTY NW WINDS
DIMINISHING DURING SUN AFTERNOON. COULD SEE EXTENDED PERIOD OF
IFR OR LOWER IN SN/FZRA/RA MON NIGHT INTO TUE NIGHT.
&&
.MARINE...
SHORT TERM...WINDS/WAVES BELOW SMALL CRAFT LEVELS INTO TOMORROW
MORNING BEFORE INTENSE COLD ADVECTION BEHIND AN ARCTIC COLD FRONT
BRINGS A PERIOD OF GALES TO THE OUTER WATERS BY LATE SATURDAY
AFTERNOON THROUGH SUNDAY MORNING WITH WINDS LIKELY REMAINING BELOW
GALE FORCE IN THE BAYS. IN ADDITION...HEAVY FREEZING SPRAY
WARNINGS HAVE BEEN HOISTED SATURDAY EVENING THROUGH SUNDAY MORNING
GIVEN THE COMBINATION OF THE AFOREMENTIONED WINDS AND THE COLDEST
AIRMASS OF THE SEASON THUS FAR.
LONG TERM...NW WIND DIMINISH SLOWLY THRU SUNDAY...AS DOES
INTENSITY OF FREEZING SPRAY...BUT WILL LKLY HOLD TO SCA WINDS
THRU SUN EVE. AFTER A BRIEF BREAK IN THE WINDS ON MON AND MON
NIGHT...LOOK FOR S WINDS TO REACH SCA LVLS EARLY TUE AND COULD
REACH GALES BY TUE AFTERNOON AND EVE...BEFORE DIMINISHING WED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL WARNING FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST
SUNDAY FOR MEZ012>014-018>022.
WIND CHILL WARNING FROM 7 PM SATURDAY TO 10 AM EST SUNDAY FOR
MEZ007>009.
WIND CHILL ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST
SUNDAY FOR MEZ023>028.
WINTER STORM WATCH FROM MIDNIGHT EST TONIGHT THROUGH SATURDAY
EVENING FOR MEZ022-027-028.
NH...WIND CHILL WARNING FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST
SUNDAY FOR NHZ004>013-015.
WIND CHILL WARNING FROM 7 PM SATURDAY TO 10 AM EST SUNDAY FOR
NHZ001>003.
WIND CHILL ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 10 AM EST
SUNDAY FOR NHZ014.
MARINE...HEAVY FREEZING SPRAY WARNING FROM 7 PM SATURDAY TO 10 AM EST
SUNDAY FOR ANZ150>154.
SMALL CRAFT ADVISORY FROM NOON SATURDAY TO 10 AM EST SUNDAY
FOR ANZ151-153.
GALE WARNING FROM 4 PM SATURDAY TO 10 AM EST SUNDAY FOR ANZ150-
152-154.
&&
$$
SYNOPSIS...ARNOTT
NEAR TERM...ARNOTT
SHORT TERM...ARNOTT
LONG TERM...CEMPA
AVIATION...ARNOTT/CEMPA
MARINE...ARNOTT/CEMPA
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
548 PM EST FRI FEB 12 2016
.SYNOPSIS...
AN ARCTIC FRONT WILL BRING SNOW SHOWERS TO THE AREA THROUGH
SATURDAY. MUCH COLDER TEMPERATURES AND DANGEROUS WIND CHILLS WILL
CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
BASED ON LATEST OBSERVATIONS AND RADAR TRENDS CURRENT TIMING OF
POTENTIAL SQUALL CONDITIONS STILL LOOKS GOOD AS WV IMAGERY SHOWS
THE JET CORE ROUNDING THE BASE OF THE LONGWAVE PIVOTING OVER THE
AREA. NOT MUCH CHANGE IS NEEDED AT THIS TIME TO THE ONGOING
FORECAST OTHER THAN MINOR ADJUSTMENTS TO HOURLY TEMPERATURES.
PREV DISCUSSION FOLLOWS..
SHORTWAVE PIVOTING ALONG THE BASE OF THE UPPER TROUGH WILL SUPPORT
INCREASING SNOW CHANCES IN THE RIDGES AHEAD OF THE ARCTIC FRONT
PASSAGE PROGGED FOR THIS EVENING/OVERNIGHT. BOTH HI RES AND LONGER
RANGE MODEL SOUNDINGS IN BUFKIT SUGGEST A PERIOD WHERE DEEP
MOISTURE...IN A LAYER FROM ABOUT 600MB TO 850MB...WILL BE WELL
WITHIN THE DENDRITIC GROWTH ZONE. THIS SHOULD SUPPORT EFFICIENT
SNOWFALL FOR A PERIOD...WITH ADDITIONAL SNOW SHOWERS ANTICIPATED
WITH AND BEHIND THE FRONT IN UPSLOPE SNOW UNTIL THE WHOLE BOUNDARY
LAYER FALLS WELL BELOW THE GROWTH ZONE. WITH THIS IN MIND...A
WINTER WEATHER ADVISORY WAS ISSUED FOR THE RIDGES OF PRESTON
TUCKER AND GARRETT COUNTIES THROUGH SATURDAY MORNING.
ELSEWHERE...THE MODEL GUIDANCE HAS CHANGED LITTLE WITH THE TIMING
OF THE SNOW SHOWERS AND POTENTIAL SQUALLS AHEAD OF THE FRONT
PROGGED FOR PASSAGE OVERNIGHT. EXPECT THE LINE TO BE INTO EASTERN
OHIO AND NORTHWESTERN PA BY 00Z AND PITTSBURGH BY 03Z. VARIOUS
RUNS OF THE HRRR AND TO A LESSER DEGREE OTHER SNOW SQUALLS PROGS SUGGEST
THAT THERE WILL BE SOME WEAKENING AS THE LINE COMES ACROSS.
GENERALLY ANTICIPATE A HALF TO AN INCH OF SNOW...WITH SLIGHTLY
HIGHER AMOUNTS NORTH OF PITTSBURGH.
BEHIND THE FRONT...STRONG COLD ADVECTION WILL STEEPEN LAPSE RATES
AND PROVIDE FOR A PERIOD OF GUSTY WINDS AREAWIDE UNTIL LATE
SATURDAY WITH MAXIMUM WIND IN THE BOUNDARY LAYER APPROACHING 25
TO 35KTS. THIS...ADDED TO TEMPERATURES FALLING INTO THE SINGLE
DIGITS WILL LEAD TO WIND CHILL VALUES WELL BELOW ZERO. THIS
SUPPORTS THE WIND CHILL ADVISORY THAT WAS ISSUED. 40MPH WIND
GUSTS OVERNIGHT IN THE RIDGES WILL ALLOW VALUES TO GET VERY CLOSE
TO WARNING CRITERIA BUT AT THIS POINT...THE WATCH HAS BEEN
UPGRADED TO AN ADVISORY WITH SOME -25 VALUES POSSIBLE IN THE
HIGHEST TERRAIN OF TUCKER COUNTY.
IN ADDITION TO THE WIND...LAKE EFFECT SNOW SHOWERS WILL BE
POSSIBLE IN NORTHWEST FLOW WITH MOST IF NOT ALL OF THE MODEL
GUIDANCE SUGGESTING SEVERAL DUAL-LAKE SNOW BANDS. THE LATEST
ITERATION OF MODELS HAS THE MORE PROMINENT BAND SHIFTED SLIGHTLY
SOUTH FROM LAST NIGHT SO WITH UNCERTAINTY IN THE ACTUAL PLACEMENT
OF SNOW BANDS...HAVE OPTED TO UPGRADE THE LAKE EFFECT SNOW WATCH
FOR VENANGO COUNTY TO AN ADVISORY FOR MERCER...VENANGO...AND
FOREST COUNTIES. ADDITIONAL LAKE PLUMES MAY SUPPORT SNOW BEYOND
THESE ADVISORIES THROUGH SATURDAY AFTERNOON...BUT WITH UNCERTAINTY
IN THEIR PLACEMENT...NO ADDITIONAL HEADLINES WERE ADDED.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO TAPER OFF AND SHIFT
NORTHWARD AS A SURFACE RIDGE ATTEMPTS TO BUILD OVERHEAD FOR
SUNDAY. THIS SHOULD ALLOW FOR THE WIND TO BACK OFF...WITH WIND
CHILL CONCERNS DIMINISHING IN OHIO. HOWEVER...WITH THE HIGH
PRESSURE AND LIGHT WIND...TEMPERATURES WILL FALL CLOSE TO OR BELOW
ZERO SATURDAY NIGHT...SO ADVISORIES WILL REMAIN AS IS FOR THE REST
OF THE CWA UNTIL SUNDAY MORNING. TEMPERATURES WILL MODERATE A FEW
DEGREES ON SUNDAY WITH A RETURN OF SOUTHERLY FLOW AND SCATTERING
OF THE CLOUDS. TEMPERATURE FORECAST WAS A BLEND OF GUIDANCE FOR
BOTH PERIODS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
SHORTWAVE MOVING EAST ACROSS THE GREAT LAKES WILL BRING WARM
ADVECTION ALONG WITH AN INCREASE IN DEEPER MOISTURE SUNDAY NIGHT
INTO MONDAY. THIS WILL GIVE A PERIOD OF SNOW ESPECIALLY SOUTH OF
PITTSBURGH WITH SOME ACCUMULATION EXPECTED. TEMPERATURES LOOK TO
RISE LATER SUNDAY NIGHT AND WILL PUSH TO NEAR THE SEASONAL AVERAGE
MONDAY. BY LATER MONDAY THROUGH TUESDAY A STRONG SOUTHERN STREAM
SHORTWAVE WILL INDUCE LOW PRESSURE ALONG THE GULF COAST WHICH WILL
QUICKLY MOVE ACROSS THE MID ATLANTIC STATES. MODELS STILL DIFFER
ON EXACT TRACK BUT SYSTEM WILL CROSS THE SOUTHERN APPALACHIANS AND
INTENSIFY AS IT MOVES TOWARD NEW ENGLAND BY TUESDAY NIGHT.
POTENTIAL FOR SIGNIFICANT SNOW...BUT ALSO POTENTIAL FOR A MIX WITH
RAIN OR ALL RAIN WHERE BETTER QPF IS FORECAST. FOR NOW HAVE NOT
STRAYED FAR FROM PREVIOUS FORECAST ALTHOUGH EVEN THE WARMER ECMWF
WRAPS COLD AIR BACK IN LATER TUESDAY SO HAVE KEPT MAINLY SNOW.
SYSTEM EXITS TUESDAY NIGHT...BUT WILL BE FOLLOWED BY FAST MOVING
CLIPPER SYSTEM WEDNESDAY WHICH WILL DELIVER ANOTHER PERIOD OF SNOW
SHOWERS FOLLOWED BY A QUICK SHOT OF COLD AIR. HEIGHTS ALOFT THEN
BEGIN TO RISE THURSDAY INTO FRIDAY WITH STRONG WARM
ADVECTION...ESPECIALLY ON FRIDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
LIGHT SNOW HAS DROPPED VSBY TO MVFR OR BELOW FOR A TIME AT KMGW AND
KLBE AS A SHORTWAVE SHIFTS EAST TO THE MID ATLANTIC. SNOW SHOWERS
ALSO WILL DEVELOP AHEAD OF APPROACHING ARCTIC FRONT...WITH MVFR TO
IFR THIS EVENING WITH AND BEHIND THE FRONT. WINDS WILL BE GUSTY OVER
25KTS AND TURNING NORTHWEST WITH AND BEHIND THE FRONT.
.OUTLOOK.../FRIDAY NIGHT THROUGH WEDNESDAY/...
SCATTERED RESTRICTIONS IN SNOW SHOWERS SATURDAY. LOW PRESSURE
SYSTEMS WILL BRING WIDESPREAD RESTRICTIONS LATER SUNDAY NIGHT
THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR MDZ001.
WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001.
OH...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST
SATURDAY FOR OHZ039-048-049-057>059-068-069.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR OHZ040-041-050.
PA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR PAZ007>009-013>016-020>023-029-031-073>076.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST SATURDAY FOR
PAZ007>009.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST
SATURDAY FOR WVZ003-004-012.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR WVZ001-002-021-509>514.
WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR
WVZ512>514.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
423 PM EST FRI FEB 12 2016
.SYNOPSIS...
AN ARCTIC FRONT WILL BRING SNOW SHOWERS TO THE AREA THROUGH
SATURDAY. MUCH COLDER TEMPERATURES AND DANGEROUS WIND CHILLS WILL
CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
SHORTWAVE PIVOTING ALONG THE BASE OF THE UPPER TROUGH WILL SUPPORT
INCREASING SNOW CHANCES IN THE RIDGES AHEAD OF THE ARCTIC FRONT
PASSAGE PROGGED FOR THIS EVENING/OVERNIGHT. BOTH HI RES AND LONGER
RANGE MODEL SOUNDINGS IN BUFKIT SUGGEST A PERIOD WHERE DEEP
MOISTURE...IN A LAYER FROM ABOUT 600MB TO 850MB...WILL BE WELL
WITHIN THE DENDRITIC GROWTH ZONE. THIS SHOULD SUPPORT EFFICIENT
SNOWFALL FOR A PERIOD...WITH ADDITIONAL SNOW SHOWERS ANTICIPATED
WITH AND BEHIND THE FRONT IN UPSLOPE SNOW UNTIL THE WHOLE BOUNDARY
LAYER FALLS WELL BELOW THE GROWTH ZONE. WITH THIS IN MIND...A
WINTER WEATHER ADVISORY WAS ISSUED FOR THE RIDGES OF PRESTON
TUCKER AND GARRETT COUNTIES THROUGH SATURDAY MORNING.
ELSEWHERE...THE MODEL GUIDANCE HAS CHANGED LITTLE WITH THE TIMING
OF THE SNOW SHOWERS AND POTENTIAL SQUALLS AHEAD OF THE FRONT
PROGGED FOR PASSAGE OVERNIGHT. EXPECT THE LINE TO BE INTO EASTERN
OHIO AND NORTHWESTERN PA BY 00Z AND PITTSBURGH BY 03Z. VARIOUS
RUNS OF THE HRRR AND TO A LESSER DEGREE OTHER SNOW SQUALLS PROGS SUGGEST
THAT THERE WILL BE SOME WEAKENING AS THE LINE COMES ACROSS.
GENERALLY ANTICIPATE A HALF TO AN INCH OF SNOW...WITH SLIGHTLY
HIGHER AMOUNTS NORTH OF PITTSBURGH.
BEHIND THE FRONT...STRONG COLD ADVECTION WILL STEEPEN LAPSE RATES
AND PROVIDE FOR A PERIOD OF GUSTY WINDS AREAWIDE UNTIL LATE
SATURDAY WITH MAXIMUM WIND IN THE BOUNDARY LAYER APPROACHING 25
TO 35KTS. THIS...ADDED TO TEMPERATURES FALLING INTO THE SINGLE
DIGITS WILL LEAD TO WIND CHILL VALUES WELL BELOW ZERO. THIS
SUPPORTS THE WIND CHILL ADVISORY THAT WAS ISSUED. 40MPH WIND
GUSTS OVERNIGHT IN THE RIDGES WILL ALLOW VALUES TO GET VERY CLOSE
TO WARNING CRITERIA BUT AT THIS POINT...THE WATCH HAS BEEN
UPGRADED TO AN ADVISORY WITH SOME -25 VALUES POSSIBLE IN THE
HIGHEST TERRAIN OF TUCKER COUNTY.
IN ADDITION TO THE WIND...LAKE EFFECT SNOW SHOWERS WILL BE
POSSIBLE IN NORTHWEST FLOW WITH MOST IF NOT ALL OF THE MODEL
GUIDANCE SUGGESTING SEVERAL DUAL-LAKE SNOW BANDS. THE LATEST
ITERATION OF MODELS HAS THE MORE PROMINENT BAND SHIFTED SLIGHTLY
SOUTH FROM LAST NIGHT SO WITH UNCERTAINTY IN THE ACTUAL PLACEMENT
OF SNOW BANDS...HAVE OPTED TO UPGRADE THE LAKE EFFECT SNOW WATCH
FOR VENANGO COUNTY TO AN ADVISORY FOR MERCER...VENANGO...AND
FOREST COUNTIES. ADDITIONAL LAKE PLUMES MAY SUPPORT SNOW BEYOND
THESE ADVISORIES THROUGH SATURDAY AFTERNOON...BUT WITH UNCERTAINTY
IN THEIR PLACEMENT...NO ADDITIONAL HEADLINES WERE ADDED.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO TAPER OFF AND SHIFT
NORTHWARD AS A SURFACE RIDGE ATTEMPTS TO BUILD OVERHEAD FOR
SUNDAY. THIS SHOULD ALLOW FOR THE WIND TO BACK OFF...WITH WIND
CHILL CONCERNS DIMINISHING IN OHIO. HOWEVER...WITH THE HIGH
PRESSURE AND LIGHT WIND...TEMPERATURES WILL FALL CLOSE TO OR BELOW
ZERO SATURDAY NIGHT...SO ADVISORIES WILL REMAIN AS IS FOR THE REST
OF THE CWA UNTIL SUNDAY MORNING. TEMPERATURES WILL MODERATE A FEW
DEGREES ON SUNDAY WITH A RETURN OF SOUTHERLY FLOW AND SCATTERING
OF THE CLOUDS. TEMPERATURE FORECAST WAS A BLEND OF GUIDANCE FOR
BOTH PERIODS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
SHORTWAVE MOVING EAST ACROSS THE GREAT LAKES WILL BRING WARM
ADVECTION ALONG WITH AN INCREASE IN DEEPER MOISTURE SUNDAY NIGHT
INTO MONDAY. THIS WILL GIVE A PERIOD OF SNOW ESPECIALLY SOUTH OF
PITTSBURGH WITH SOME ACCUMULATION EXPECTED. TEMPERATURES LOOK TO
RISE LATER SUNDAY NIGHT AND WILL PUSH TO NEAR THE SEASONAL AVERAGE
MONDAY. BY LATER MONDAY THROUGH TUESDAY A STRONG SOUTHERN STREAM
SHORTWAVE WILL INDUCE LOW PRESSURE ALONG THE GULF COAST WHICH WILL
QUICKLY MOVE ACROSS THE MID ATLANTIC STATES. MODELS STILL DIFFER
ON EXACT TRACK BUT SYSTEM WILL CROSS THE SOUTHERN APPALACHIANS AND
INTENSIFY AS IT MOVES TOWARD NEW ENGLAND BY TUESDAY NIGHT.
POTENTIAL FOR SIGNIFICANT SNOW...BUT ALSO POTENTIAL FOR A MIX WITH
RAIN OR ALL RAIN WHERE BETTER QPF IS FORECAST. FOR NOW HAVE NOT
STRAYED FAR FROM PREVIOUS FORECAST ALTHOUGH EVEN THE WARMER ECMWF
WRAPS COLD AIR BACK IN LATER TUESDAY SO HAVE KEPT MAINLY SNOW.
SYSTEM EXITS TUESDAY NIGHT...BUT WILL BE FOLLOWED BY FAST MOVING
CLIPPER SYSTEM WEDNESDAY WHICH WILL DELIVER ANOTHER PERIOD OF SNOW
SHOWERS FOLLOWED BY A QUICK SHOT OF COLD AIR. HEIGHTS ALOFT THEN
BEGIN TO RISE THURSDAY INTO FRIDAY WITH STRONG WARM
ADVECTION...ESPECIALLY ON FRIDAY.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
LIGHT SNOW HAS DROPPED VSBY TO MVFR OR BELOW FOR A TIME AT KMGW AND
KLBE AS A SHORTWAVE SHIFTS EAST TO THE MID ATLANTIC. SNOW SHOWERS
ALSO WILL DEVELOP AHEAD OF APPROACHING ARCTIC FRONT...WITH MVFR TO
IFR THIS EVENING WITH AND BEHIND THE FRONT. WINDS WILL BE GUSTY OVER
25KTS AND TURNING NORTHWEST WITH AND BEHIND THE FRONT.
.OUTLOOK.../FRIDAY NIGHT THROUGH WEDNESDAY/...
SCATTERED RESTRICTIONS IN SNOW SHOWERS SATURDAY. LOW PRESSURE
SYSTEMS WILL BRING WIDESPREAD RESTRICTIONS LATER SUNDAY NIGHT
THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR MDZ001.
WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001.
OH...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST
SATURDAY FOR OHZ039-048-049-057>059-068-069.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR OHZ040-041-050.
PA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR PAZ007>009-013>016-020>023-029-031-073>076.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST SATURDAY FOR
PAZ007>009.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST
SATURDAY FOR WVZ003-004-012.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR WVZ001-002-021-509>514.
WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR
WVZ512>514.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
145 PM EST FRI FEB 12 2016
.SYNOPSIS...
AN ARCTIC FRONT WILL BRING SNOW SHOWERS TO THE AREA LATER TODAY
THROUGH SATURDAY. MUCH COLDER TEMPERATURES AND DANGEROUS WIND
CHILLS WILL CONTINUE INTO THE WEEKEND BEHIND IT.
&&
.NEAR TERM /THROUGH SATURDAY/...
SHORTWAVE PIVOTING ALONG THE BASE OF THE UPPER TROUGH WILL SUPPORT
INCREASING SNOW CHANCES IN THE RIDGES LATER THIS AFTERNOON AHEAD
OF THE ARCTIC FRONT PASSAGE PROGGED FOR THIS EVENING/OVERNIGHT.
BOTH HI RES AND LONGER RANGE MODEL SOUNDINGS IN BUFKIT SUGGEST A
PERIOD WHERE DEEP MOISTURE...IN A LAYER FROM ABOUT 600MB TO
850MB...WILL BE WELL WITHIN THE DENDRITIC GROWTH ZONE. THIS SHOULD
SUPPORT EFFICIENT SNOWFALL FOR A PERIOD THIS AFTERNOON AHEAD OF
THE ARCTIC FRONT...WITH ADDITIONAL SNOW SHOWERS ANTICIPATED WITH
AND BEHIND THE FRONT IN UPSLOPE SNOW UNTIL THE WHOLE BOUNDARY
LAYER FALLS WELL BELOW VALUES FOR EFFICIENT SNOWFALL. WITH THIS IN
MIND...A WINTER WEATHER ADVISORY WAS ISSUED FOR THE RIDGES OF
PRESTON TUCKER AND GARRETT COUNTIES THROUGH SATURDAY MORNING.
ELSEWHERE...THE MODEL GUIDANCE HAS CHANGED LITTLE WITH THE TIMING
OF THE SNOW SHOWERS AND POTENTIAL SQUALLS AHEAD OF THE FRONT
PROGGED FOR PASSAGE OVERNIGHT. EXPECT THE LINE TO BE INTO EASTERN
OHIO AND NORTHWESTERN PA BY 00Z AND PITTSBURGH BY 03Z. VARIOUS
RUNS OF THE HRRR AND TO A LESSER DEGREE OTHER SNOW SQUALLS PROGSSUGGEST
THAT THERE WILL BE SOME WEAKENING AS THE LINE COMES ACROSS.
GENERALLY ANTICIPATE A HALF TO AN INCH OF SNOW...WITH SLIGHTLY
HIGHER AMOUNTS NORTH OF PITTSBURGH.
BEHIND THE FRONT...STRONG COLD ADVECTION WILL STEEPEN LAPSE RATES
AND PROVIDE FOR A PERIOD OF GUSTY WINDS AREAWIDE UNTIL LATE
SATURDAY WITH MAXIMUM WIND IN THE BOUNDARY LAYER APPROACHING 25
TO 35KTS. THIS...ADDED TO TEMPERATURES FALLING INTO THE SINGLE
DIGITS WILL LEAD TO WIND CHILL VALUES WELL BELOW ZERO. THIS
SUPPORTS THE WIND CHILL ADVISORY THAT WAS ISSUED WITH ADDITIONAL
CONCERN FOR THE RIDGES...AS 40MPH WIND GUSTS MAY SUPPORT AN
UPGRADE OF THE WIND CHILL WATCH THIS AFTERNOON. FURTHER ANALYSIS
WILL BE MADE WITH A DECISION LATER IN THIS SHIFT.
IN ADDITION TO THE WIND...LAKE EFFECT SNOW SHOWERS WILL BE
POSSIBLE IN NORTHWEST FLOW WITH MOST IF NOT ALL OF THE MODEL
GUIDANCE SUGGESTING SEVERAL GUAL-LAKE SNOW BANDS. THE LATEST
ITERATION OF MODELS HAS THE MORE PROMINENT BAND SHIFTED SLIGHTLY
SOUTH FROM LAST NIGHT SO WITH UNCERTAINTY IN THE ACTUAL PLACEMENT
OF SNOW BANDS...HAVE OPTED TO UPGRADE THE LAKE EFFECT SNOW WATCH
FOR VENANGO COUNTY TO AN ADVISORY FOR MERCER...VENANGO...AND
FOREST COUNTIES. ADDITIONAL LAKE PLUMES MAY SUPPORT SNOW BEYOND
THESE ADVISORIES THROUGH SATURDAY AFTERNOON...BUT WITH UNCERTAINTY
IN THEIR PLACEMENT...NO ADDITIONAL HEADLINES WERE ADDED.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
LAKE-EFFECT SNOW SHOWERS ACROSS THE NORTH WILL BE WANING LATE
SATURDAY NIGHT AS THE UPPER-LEVEL LOW MOVES EAST AND A SURFACE HIGH
APPROACHES FROM THE WEST. NORTHWEST FLOW BEHIND THE EXITING FRONT
WILL BRING TEMPERATURES NEAR THE ZERO DEGREE MARK FOR SUNDAY MORNING
LOWS. WITH HIGH PRESSURE STARTING TO BUILD IN...WINDS WILL BE
DECREASING ACROSS EASTERN OHIO. TO THE EAST AND NORTH
HOWEVER...SEVERAL MORE HOURS OF STRONG AND GUSTY WINDS WILL MEAN
WIND CHILL VALUES BELOW -10F. THE HIGHEST ELEVATIONS COULD SEE WIND
CHILLS AT OR BELOW -25F. WITH THIS IN MIND...THE WIND CHILL ADVISORY
WILL CONTINUE FOR MUCH OF THE CWA INTO SUNDAY MORNING...WITH A WIND
CHILL WATCH ACROSS GARRETT AND EASTERN TUCKER COUNTIES.
BRIEF RIDGING SUNDAY AFTERNOON WILL FINALLY DISRUPT THE MEAN
NORTHWEST FLOW PATTERN ALOFT. WARM AIR ADVECTION WILL GRADUALLY KICK
INTO GEAR...BUT WITH SUCH A LOW STARTING POINT...HIGHS WILL STAY
WELL BELOW AVERAGE SUNDAY. THE NEXT WEAK WAVE ARRIVES MONDAY MORNING
SPREADING CLOUDS AND LIGHT SNOW BACK ACROSS THE FORECAST AREA. AN
INCREASE OF CLOUD COVER AND RELATIVELY WARMER AIR SURGING NORTHWARD
WILL KEEP LOWS FROM BOTTOMING OUT MONDAY MORNING.
TAX
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A DIGGING TROUGH WILL DEEPEN A SURFACE LOW NEAR THE LOWER MISSISSIPPI
VALLEY MONDAY. STRONG SUPPORT FROM THE UPPER-LEVEL JET WILL DEEPEN
THE LOW FURTHER AS IT ADVANCES THROUGH THE SOUTHEASTERN CONUS MONDAY
AFTERNOON. INCREASED SOUTHERLY FLOW WILL TAP INTO GULF AND ATLANTIC
MOISTURE...SPREADING IT NORTHWARD INTO OUR REGION AND EAST. STRONG
ISENTROPIC ASCENT WILL BRING PRECIPITATION THROUGH AT LEAST OUR
EASTERN ZONES BY LATE MONDAY INTO TUESDAY MORNING. STILL QUESTIONS
SURROUNDING THE EXACT TRACK OF THE LOW AND THE RESULTANT WESTWARD
EDGE OF PRECIPITATION...PRECIPITATION TYPE...AND INTENSITY. AS OF THE
00Z RUNS...GUIDANCE IS FAIRLY CONSISTENT ACROSS THE MODEL
SUITE...BUT ALL HAVE NUDGED THE SURFACE LOW WEST OF THEIR POSITION
24HRS AGO.
CURRENT FORECAST CALLS FOR LIKELY SNOW TUESDAY MORNING REACHING WEST
TO THE OHIO RIVER INCLUDING PITTSBURGH. SIGNIFICANT MODEL SPREAD
DOES EXIST FOR HIGH TEMPERATURE VALUES TUESDAY...AND WITH THE
WESTWARD TREND...HAVE BUMPED UP HIGHS A FEW DEGREES. THIS WOULD
FAVOR AT LEAST SOME MIX OF RAIN/SNOW TUESDAY AFTERNOON THAT COULD
ULTIMATELY CUT INTO THE POTENTIAL FOR ACCUMULATING SNOW. BEHIND THIS
SYSTEM...THE BROAD UPPER TROUGH WILL BRIEFLY RE-ESTABLISH OVER THE
NORTHEAST. TEMPERATURES WILL INITIALLY DROP BELOW AVERAGE
THURSDAY...BEFORE REBOUNDING WITH WARM AIR ADVECTION BY THE WEEKEND.
TAX
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE MORNING BEFORE THE NEXT
SYSTEM BRINGS ANOTHER ROUND OF SNOW AND FLIGHT RESTRICTIONS THIS
AFTERNOON/EVENING. GUSTY NORTHWEST WINDS WILL COMMENCE BY EVENING
AS A COLD FRONT MOVES THROUGH THE AREA WITH A BURST OF SNOW
SHOWERS ALONG IT.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
RESTRICTIONS WILL BE POSSIBLE IN SNOW SHOWERS LATER FRIDAY INTO
SATURDAY. THE NEXT CHANCE FOR WIDESPREAD IFR WILL BE WITH LOW
PRESSURE MONDAY AND TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST
SATURDAY FOR MDZ001.
WIND CHILL WATCH FROM MIDNIGHT EST TONIGHT THROUGH SUNDAY
MORNING FOR MDZ001.
OH...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST
SATURDAY FOR OHZ039-048-049-057>059-068-069.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR OHZ040-041-050.
PA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR PAZ007>009-013>016-020>023-029-031-073>076.
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
SATURDAY FOR PAZ007>009.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST
SATURDAY FOR WVZ003-004-012.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
FOR WVZ001-002-021-509>513.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST
SATURDAY FOR WVZ512>514.
WIND CHILL WATCH FROM MIDNIGHT EST TONIGHT THROUGH SUNDAY
MORNING FOR WVZ514.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
710 PM EST SAT FEB 13 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 401 PM EST SAT FEB 13 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP TROF OVER SE CANADA
INTO THE NE CONUS WITH THE CORE OF THE COLDEST AIR WELL E OF HERE
NOW. UPSTREAM...NEXT SHORTWAVE OF INTEREST IS MOVING ACROSS THE NRN
ROCKIES. CLOSER TO HOME...WITH LATEST RAP ANALYSIS SHOWING 850MB
TEMPS ACROSS LAKE SUPERIOR RANGING FROM AROUND -19C W TO -25C E...
LES CONTINUES. HOWEVER...UNDER RISING HEIGHTS/SUBSIDENCE...
INVERSION IS DOWN TO AROUND 3KFT W AND 5KFT E. SO...LES IS LIGHT...
BUT STILL EFFECTIVE AT REDUCING VIS OVER THE E DUE TO SMALL
SNOWFLAKE SIZE. WELL AWAY FROM LAKE EFFECT...IT`S BEEN A MOSTLY
SUNNY DAY OVER SCNTRL UPPER MI.
LINGERING LIGHT LES WILL END FROM W TO E TONIGHT AS SFC HIGH PRES
RIDGE PASSES ACROSS THE FCST AREA. WITH MODERATING AIR MASS
RESULTING IN THE DGZ LIFTING INTO THE SHALLOW CONVECTIVE
LAYER...MIGHT BE ABLE TO FLUFF UP AN INCH OR TWO OF SNOW
ACCUMULATION WHERE STRENGTHENING LAND BREEZES FOCUS CONVERGENCE...
MOST LIKELY IN THE E HALF OF ALGER/NRN SCHOOLCRAFT COUNTIES. RIDGE
WILL ARRIVE OVER WRN UPPER MI EARLY THIS EVENING AND THE E
OVERNIGHT. LOSS OF LAKE EFFECT CLOUDS WITH BACKING WINDS WILL BE
REPLACED BY SOME INCREASE IN HIGH CLOUDS IN WAA PATTERN AHEAD OF
SHORTWAVE MOVING INTO THE NRN/CNTRL PLAINS. THAT SAID...ALL AREAS
WILL SEE AT LEAST A SHORT PERIOD OF VERY GOOD RADIATIONAL COOLING
CONDITIONS. IT STILL APPEARS THE CNTRL FCST AREA WILL HAVE THE
LONGEST PERIOD OF EXCELLENT RADIATIONAL COOLING DUE TO CLEAR SKIES
TO START THE EVENING...LATER ARRIVAL OF HIGH CLOUDS AND LONGER
PERIOD OF LIGHT/CALM WIND. AS WITH PREVIOUS FCSTS...MAINTAINED A MIN
TEMP FCST AT OR BLO THE LOWEST GUIDANCE WITH THE TRADITIONAL COLDEST
SPOTS FALLING TOWARD -20F. MOST IF NOT ALL LOCATIONS WILL FALL BLO
0F.
ON SUN...SHORTWAVE MOVING OUT OVER THE PLAINS TONIGHT WILL TRACK ESE
WITH ASSOCIATED DEEP LAYER FORCING PER QVECTORS AND BEST ISENTROPIC
ASCENT PASSING S OF UPPER MI. MODEL TREND OF RECENT DAYS TO PUSH
FORCING/PCPN FARTHER S HAS HELD UP IN LATEST MODEL RUNS. AS A
RESULT...DO NOT EXPECT ANY -SN ASSOCIATED WITH THIS FEATURE TO REACH
THE FCST AREA SUN. ATTENTION THEN TURNS TO LES OFF LAKE MICHIGAN
UNDER DEVELOPING/INCREASING SOUTHERLY FLOW ON THE BACKSIDE OF
DEPARTING HIGH PRES. 850MB TEMPS AROUND -17C AT 12Z RISE TO AROUND
-14C BY 00Z MON...CERTAINLY LOW ENOUGH TO SUPPORT LES. LARGE SCALE
ANTICYCLONIC FLOW AND INVERSIONS AT 4-5KFT WILL LIMIT INTENSITY OF
LES. IN ADDITION...MOST HIGH RES MODEL GUIDANCE DEPICT THE LES
MOSTLY AS A BAND LIFTING N ON A WIND CONVERGENCE ZONE. WHILE THIS
MAY LEAD TO A BURST OF MDT SNOWFALL...ESPECIALLY WITH DGZ SOLIDLY IN
THE CONVECTIVE LAYER...THE HEAVIER SNOW WOULD NOT LAST LONG. FOR
NOW...EXPECT SNOW ACCUMULATIONS UNDER 1 INCH...BUT NOT OUT OF THE
QUESTION FOR LOCALIZED INCH OR TWO OF SNOW ACCUMULATION IF THE
CONVERGENCE ZONE IS STRONG.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 PM EST SAT FEB 13 2016
LONG TERM STARTS 00Z MON WITH A SHORTWAVE NEAR SRN LAKE MICHIGAN
THAT WILL CROSS LAKE HURON BY 12Z MON AND THEN MOVE INTO
QUEBEC...AND ANOTHER SHORTWAVE OVER CENTRAL MN THAT WILL MOVE OVER
OR JUST S OF THE CWA LATE SUN NIGHT INTO MON AFTERNOON...AND YET
ANOTHER SHORTWAVE WILL FOLLOW THE SECOND BY ABOUT 12 HOURS. NOT
REALLY LOOKING FOR A LOT OF SYNOPTIC QPF...BUT THE FORCING/MOISTURE
WILL ENHANCE LES OFF LAKE MICHIGAN IN THE SLY FLOW AHEAD OF THE
ACCOMPANYING SFC TROUGH. SLY WIND LAKE EFFECT IS ALWAYS TRICKY...BUT
LOOKS LIKE IT SHOULD START UP AROUND 00Z MON AND REACH A PEAK
BETWEEN 06Z AND 18Z MON WHILE SHIFTING E AND ENDING BEFORE 00Z TUE.
AT THIS POINT...IT LOOKS LIKE THE MOST SNOW WILL FALL ACROSS
MENOMINEE...DELTA...AND SCHOOLCRAFT COUNTIES...AND POSSIBLY INTO
COUNTIES JUST N OF THOSE. THINK WITH S WINDS...THINK MENOMINEE
COUNTY SEEING MUCH LES IS NOT AS LIKELY. OVERALL...ONLY EXPECTING 2
TO MAYBE 3 INCHES IN THESE AREAS. ELSEWHERE...AROUND AN INCH OR LESS.
MAY SEE SOME LIGHT LES OVER W WIND SNOWBELTS MON NIGHT INTO TUE
MORNING AS 850MB TEMPS WILL BE MARGINAL BUT ADDITIONAL SHORTWAVE
WILL PROVIDE SOME ENHANCEMENT. NOT LOOKING AT SIGNIFICANT AMOUNTS.
SFC TROUGH MOVES THROUGH TUE AHEAD OF AN UPPER WAVE. THIS TURNS
WINDS OUT OF THE NW-NNW BY TUE AFTERNOON/EVENING AND DROPS 850MB
TEMPS TO AROUND-15Z BY 00Z WED AND -19C BY 12Z WED. A SFC RIDGE
MOVES THROUGH BY 00Z THU...ENDING MOST OR ALL LES. NOT EXPECTING
SIGNIFICANT SNOWFALL AMOUNTS GIVEN CHANGING WIND DIRECTIONS AND
QUICK ENTRANCE OF THE RIDGE.
COULD SEE A MORE POTENT SYSTEM LATE IN THE WEEK...WITH THE
POSSIBILITY OF SNOW...RAIN...AND FREEZING RAIN. HOWEVER...CONFIDENCE
EVEN IN THE GENERAL STRENGTH/TRACK OF THE SYSTEM IS LOW AS MODELS
VARY FROM RUN TO RUN AND DISAGREE MODEL TO MODEL. CERTAINLY LOOKS
LIKE A WARMUP IS IN STORE FOR AT LEAST THU NIGHT AND FRI...BUT CAN
NOT SAY MUCH ELSE WITH CONFIDENCE. MAINLY WENT WITH A WINTRY MIX OF
PRECIP IN THE FORECAST...WITH CONSENSUS POPS FIELDS OTHERWISE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 709 PM EST SAT FEB 13 2016
WITH WINDS BACKING AS HIGH PRES MOVES E...CROSSING UPPER MI
TONIGHT...LINGERING LAKE EFFECT SNOW SHOWERS AFFECTING KCMX WILL END
LATE THIS EVENING WITH CONDITIONS GOING TO VFR. UNTIL THEN...EXPECT
MVFR TO IFR VSBY AT KCMX IN LES. OTHERWISE...VFR CONDITIONS ARE
EXPECTED AT KIWD AND KSAW THRU THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 401 PM EST SAT FEB 13 2016
AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR TONIGHT...WINDS WILL
DIMINISH AND BECOME LIGHT UNDER 15KT FOR A TIME. ONCE THIS HIGH
SHIFTS E OF THE AREA...S WINDS WILL INCREASE UP TO 25-30KT SUN INTO
MON MORNING UNDER THE TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING
HIGH AND AN APPROACHING LOW PRES TROF IN THE PLAINS. THERE COULD BE
A FEW GALE FORCE GUSTS SUN NIGHT OVER THE E HALF OF THE LAKE.
ALTHOUGH WINDS WILL DIMINISH LATER MON...ANOTHER ROUND OF STRONG NNW
WINDS UP TO 30KT WILL DEVELOP TUE/TUE NIGHT FOLLOWING A COLD FRONTAL
PASSAGE. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE
GUSTS. WINDS WILL THEN DIMINISH WED WITH ARRIVAL OF ANOTHER HIGH
PRES RIDGE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
703 PM EST SAT FEB 13 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 401 PM EST SAT FEB 13 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP TROF OVER SE CANADA
INTO THE NE CONUS WITH THE CORE OF THE COLDEST AIR WELL E OF HERE
NOW. UPSTREAM...NEXT SHORTWAVE OF INTEREST IS MOVING ACROSS THE NRN
ROCKIES. CLOSER TO HOME...WITH LATEST RAP ANALYSIS SHOWING 850MB
TEMPS ACROSS LAKE SUPERIOR RANGING FROM AROUND -19C W TO -25C E...
LES CONTINUES. HOWEVER...UNDER RISING HEIGHTS/SUBSIDENCE...
INVERSION IS DOWN TO AROUND 3KFT W AND 5KFT E. SO...LES IS LIGHT...
BUT STILL EFFECTIVE AT REDUCING VIS OVER THE E DUE TO SMALL
SNOWFLAKE SIZE. WELL AWAY FROM LAKE EFFECT...IT`S BEEN A MOSTLY
SUNNY DAY OVER SCNTRL UPPER MI.
LINGERING LIGHT LES WILL END FROM W TO E TONIGHT AS SFC HIGH PRES
RIDGE PASSES ACROSS THE FCST AREA. WITH MODERATING AIR MASS
RESULTING IN THE DGZ LIFTING INTO THE SHALLOW CONVECTIVE
LAYER...MIGHT BE ABLE TO FLUFF UP AN INCH OR TWO OF SNOW
ACCUMULATION WHERE STRENGTHENING LAND BREEZES FOCUS CONVERGENCE...
MOST LIKELY IN THE E HALF OF ALGER/NRN SCHOOLCRAFT COUNTIES. RIDGE
WILL ARRIVE OVER WRN UPPER MI EARLY THIS EVENING AND THE E
OVERNIGHT. LOSS OF LAKE EFFECT CLOUDS WITH BACKING WINDS WILL BE
REPLACED BY SOME INCREASE IN HIGH CLOUDS IN WAA PATTERN AHEAD OF
SHORTWAVE MOVING INTO THE NRN/CNTRL PLAINS. THAT SAID...ALL AREAS
WILL SEE AT LEAST A SHORT PERIOD OF VERY GOOD RADIATIONAL COOLING
CONDITIONS. IT STILL APPEARS THE CNTRL FCST AREA WILL HAVE THE
LONGEST PERIOD OF EXCELLENT RADIATIONAL COOLING DUE TO CLEAR SKIES
TO START THE EVENING...LATER ARRIVAL OF HIGH CLOUDS AND LONGER
PERIOD OF LIGHT/CALM WIND. AS WITH PREVIOUS FCSTS...MAINTAINED A MIN
TEMP FCST AT OR BLO THE LOWEST GUIDANCE WITH THE TRADITIONAL COLDEST
SPOTS FALLING TOWARD -20F. MOST IF NOT ALL LOCATIONS WILL FALL BLO
0F.
ON SUN...SHORTWAVE MOVING OUT OVER THE PLAINS TONIGHT WILL TRACK ESE
WITH ASSOCIATED DEEP LAYER FORCING PER QVECTORS AND BEST ISENTROPIC
ASCENT PASSING S OF UPPER MI. MODEL TREND OF RECENT DAYS TO PUSH
FORCING/PCPN FARTHER S HAS HELD UP IN LATEST MODEL RUNS. AS A
RESULT...DO NOT EXPECT ANY -SN ASSOCIATED WITH THIS FEATURE TO REACH
THE FCST AREA SUN. ATTENTION THEN TURNS TO LES OFF LAKE MICHIGAN
UNDER DEVELOPING/INCREASING SOUTHERLY FLOW ON THE BACKSIDE OF
DEPARTING HIGH PRES. 850MB TEMPS AROUND -17C AT 12Z RISE TO AROUND
-14C BY 00Z MON...CERTAINLY LOW ENOUGH TO SUPPORT LES. LARGE SCALE
ANTICYCLONIC FLOW AND INVERSIONS AT 4-5KFT WILL LIMIT INTENSITY OF
LES. IN ADDITION...MOST HIGH RES MODEL GUIDANCE DEPICT THE LES
MOSTLY AS A BAND LIFTING N ON A WIND CONVERGENCE ZONE. WHILE THIS
MAY LEAD TO A BURST OF MDT SNOWFALL...ESPECIALLY WITH DGZ SOLIDLY IN
THE CONVECTIVE LAYER...THE HEAVIER SNOW WOULD NOT LAST LONG. FOR
NOW...EXPECT SNOW ACCUMULATIONS UNDER 1 INCH...BUT NOT OUT OF THE
QUESTION FOR LOCALIZED INCH OR TWO OF SNOW ACCUMULATION IF THE
CONVERGENCE ZONE IS STRONG.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 PM EST SAT FEB 13 2016
LONG TERM STARTS 00Z MON WITH A SHORTWAVE NEAR SRN LAKE MICHIGAN
THAT WILL CROSS LAKE HURON BY 12Z MON AND THEN MOVE INTO
QUEBEC...AND ANOTHER SHORTWAVE OVER CENTRAL MN THAT WILL MOVE OVER
OR JUST S OF THE CWA LATE SUN NIGHT INTO MON AFTERNOON...AND YET
ANOTHER SHORTWAVE WILL FOLLOW THE SECOND BY ABOUT 12 HOURS. NOT
REALLY LOOKING FOR A LOT OF SYNOPTIC QPF...BUT THE FORCING/MOISTURE
WILL ENHANCE LES OFF LAKE MICHIGAN IN THE SLY FLOW AHEAD OF THE
ACCOMPANYING SFC TROUGH. SLY WIND LAKE EFFECT IS ALWAYS TRICKY...BUT
LOOKS LIKE IT SHOULD START UP AROUND 00Z MON AND REACH A PEAK
BETWEEN 06Z AND 18Z MON WHILE SHIFTING E AND ENDING BEFORE 00Z TUE.
AT THIS POINT...IT LOOKS LIKE THE MOST SNOW WILL FALL ACROSS
MENOMINEE...DELTA...AND SCHOOLCRAFT COUNTIES...AND POSSIBLY INTO
COUNTIES JUST N OF THOSE. THINK WITH S WINDS...THINK MENOMINEE
COUNTY SEEING MUCH LES IS NOT AS LIKELY. OVERALL...ONLY EXPECTING 2
TO MAYBE 3 INCHES IN THESE AREAS. ELSEWHERE...AROUND AN INCH OR LESS.
MAY SEE SOME LIGHT LES OVER W WIND SNOWBELTS MON NIGHT INTO TUE
MORNING AS 850MB TEMPS WILL BE MARGINAL BUT ADDITIONAL SHORTWAVE
WILL PROVIDE SOME ENHANCEMENT. NOT LOOKING AT SIGNIFICANT AMOUNTS.
SFC TROUGH MOVES THROUGH TUE AHEAD OF AN UPPER WAVE. THIS TURNS
WINDS OUT OF THE NW-NNW BY TUE AFTERNOON/EVENING AND DROPS 850MB
TEMPS TO AROUND-15Z BY 00Z WED AND -19C BY 12Z WED. A SFC RIDGE
MOVES THROUGH BY 00Z THU...ENDING MOST OR ALL LES. NOT EXPECTING
SIGNIFICANT SNOWFALL AMOUNTS GIVEN CHANGING WIND DIRECTIONS AND
QUICK ENTRANCE OF THE RIDGE.
COULD SEE A MORE POTENT SYSTEM LATE IN THE WEEK...WITH THE
POSSIBILITY OF SNOW...RAIN...AND FREEZING RAIN. HOWEVER...CONFIDENCE
EVEN IN THE GENERAL STRENGTH/TRACK OF THE SYSTEM IS LOW AS MODELS
VARY FROM RUN TO RUN AND DISAGREE MODEL TO MODEL. CERTAINLY LOOKS
LIKE A WARMUP IS IN STORE FOR AT LEAST THU NIGHT AND FRI...BUT CAN
NOT SAY MUCH ELSE WITH CONFIDENCE. MAINLY WENT WITH A WINTRY MIX OF
PRECIP IN THE FORECAST...WITH CONSENSUS POPS FIELDS OTHERWISE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 642 PM EST SAT FEB 13 2016
WITH WINDS BACKING AS HIGH PRES MOVES E...CROSSING UPPER MI
TONIGHT...LINGERING LAKE EFFECT SNOW SHOWERS AFFECTING KCMX WILL END
LATE THIS EVENING WITH CONDITIONS GOING TO VFR. OTHERWISE...VFR
CONDITIONS ARE EXPECTED AT KIWD AND KSAW THRU THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 401 PM EST SAT FEB 13 2016
AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR TONIGHT...WINDS WILL
DIMINISH AND BECOME LIGHT UNDER 15KT FOR A TIME. ONCE THIS HIGH
SHIFTS E OF THE AREA...S WINDS WILL INCREASE UP TO 25-30KT SUN INTO
MON MORNING UNDER THE TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING
HIGH AND AN APPROACHING LOW PRES TROF IN THE PLAINS. THERE COULD BE
A FEW GALE FORCE GUSTS SUN NIGHT OVER THE E HALF OF THE LAKE.
ALTHOUGH WINDS WILL DIMINISH LATER MON...ANOTHER ROUND OF STRONG NNW
WINDS UP TO 30KT WILL DEVELOP TUE/TUE NIGHT FOLLOWING A COLD FRONTAL
PASSAGE. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE
GUSTS. WINDS WILL THEN DIMINISH WED WITH ARRIVAL OF ANOTHER HIGH
PRES RIDGE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR
LSZ265>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
827 PM CST SAT FEB 13 2016
.UPDATE...
Issued at 825 PM CST SAT FEB 13 2016
Have made a significant adjustment to the winter weather advisory
by starting it later based on radar and short range model trends.
Regional radar loops shows the northwest-southeast band of snow from
northwest IA through northeast MO will miss the CWA overnight. the
southern edge may nick Schuyler county but no appreciable
accumulations expected. Inspection of the progged IRK sounding
reveals a desert-like sub-cloud region which will evaporate any snow
which falls out of the mid level deck. All that said still expecting
moderately strong isentropic ascent to top-down saturate this arid
zone late tonight resulting in light snow to develop across northern
MO with the best chance for accumulating snow over northeast MO.
Will also be watching for the development of freezing drizzle over
west central MO...mainly south of KC...during the pre-dawn hours.
Still looks like a small window for occurrence before the warm front
pushes through. Trend in HRRR reflectivity output has been to
decrease coverage and intensity as well as contain it more over the
southwestern counties. 00z NAM supports this.
&&
.DISCUSSION...
Issued at 327 PM CST SAT FEB 13 2016
Main forecast challenges deal with weather type and headlines. The
forecast area is really being split by wintry weather, both
spatially and temporally, with snowfall in our northeast and light
freezing drizzle in our south. The snowfall will likely start earlier
(late this evening) than the freezing drizzle, which may hold off
unto closer to sunrise. Strong isentropic ascent will eventually
saturate the lowest several thousand feet of the atmosphere in north
central to northeastern Missouri. Have delayed onset of snow several
hours based on forecast soundings,the large temperature/ dewpoint
depressions on surface observations and the relatively high cloud
bases. Forecast soundings for the Kirksville area saturate around
midnight or perhaps a little later. Have waited until then to
increase PoPs into the likely range. Snow amounts in our northeastern
zones are still expected to be in the 1" to as much as 3" range in
Schuyler County. After coordination with neighbors, have issued a
winter weather advisory for our extreme northeastern counties,
including the Kirksville area.
The other aspect of this wintry episode is the potential for
freezing drizzle in the southern half of the forecast area.
Confidence in this is quite a bit lower than with the snowfall in
the northeast. First, the lowest several thousand feet never really
saturate. Second, by the time saturation begins to lower, the warm
front lifts through, warms the surface above freezing and desaturates
the sounding aloft. So there really only looks like a marginal
potential for several hours when lift is maximized coincident with
the greatest amount of saturation. This seems to be around the 12Z
time frame +/- an hour or two. However, freezing drizzle can have a
major impact on travel as it can be deceptive in it`s ability to
slicken roads. So it`ll be important for people who have to travel
Sunday morning to understand that roads may be slick. But for now,
confidence just isn`t high enough to issue an advisory at this time.
Another clipper system will move through Monday night/ Tuesday
morning. Forecast soundings show the lowest several thousand feet to
be above freezing, even all the way into the northeastern portions of
the forecast area. So for snow, the wave should have little impact
with regards to wintry weather in the forecast area and we should see
just rain or perhaps a rain/snow mix in our northern zones.
The rest of the forecast looks quiet regarding precipitation. An
upper level ridge will spread east with low level flow out of the
south. This will help temperatures soar to well above normal levels
by Thursday into Friday. Highs may be in the 70s in parts of the
forecast area Thursday and potentially into Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 544 PM CST SAT FEB 13 2016
Widespread VFR ceilings around 5k ft agl across the region. A nw-se
oriented band of snow is developing from central IA and will stream
through northeast MO overnight with KIRK near the western edge of any
accumulating snow.
To the south expect to see MVFR ceilings form across west central MO
during the pre-dawn hours with areas of freezing drizzle developing.
May even see some sleet mixed in. The area of freezing drizzle should
expand towards central MO by late morning. Further north temperatures
will be cold enough for mainly snow across north central into
northeast MO.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...Winter Weather Advisory from 4 AM to 6 PM CST Sunday for MOZ008-
017-025-033.
&&
$$
UPDATE...MJ
DISCUSSION...CDB
AVIATION...MJ
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
559 PM CST SAT FEB 13 2016
.DISCUSSION...
Issued at 327 PM CST SAT FEB 13 2016
Main forecast challenges deal with weather type and headlines. The
forecast area is really being split by wintry weather, both
spatially and temporally, with snowfall in our northeast and light
freezing drizzle in our south. The snowfall will likely start earlier
(late this evening) than the freezing drizzle, which may hold off
unto closer to sunrise. Strong isentropic ascent will eventually
saturate the lowest several thousand feet of the atmosphere in north
central to northeastern Missouri. Have delayed onset of snow several
hours based on forecast soundings,the large temperature/ dewpoint
depressions on surface observations and the relatively high cloud
bases. Forecast soundings for the Kirksville area saturate around
midnight or perhaps a little later. Have waited until then to
increase PoPs into the likely range. Snow amounts in our northeastern
zones are still expected to be in the 1" to as much as 3" range in
Schuyler County. After coordination with neighbors, have issued a
winter weather advisory for our extreme northeastern counties,
including the Kirksville area.
The other aspect of this wintry episode is the potential for
freezing drizzle in the southern half of the forecast area.
Confidence in this is quite a bit lower than with the snowfall in
the northeast. First, the lowest several thousand feet never really
saturate. Second, by the time saturation begins to lower, the warm
front lifts through, warms the surface above freezing and desaturates
the sounding aloft. So there really only looks like a marginal
potential for several hours when lift is maximized coincident with
the greatest amount of saturation. This seems to be around the 12Z
time frame +/- an hour or two. However, freezing drizzle can have a
major impact on travel as it can be deceptive in it`s ability to
slicken roads. So it`ll be important for people who have to travel
Sunday morning to understand that roads may be slick. But for now,
confidence just isn`t high enough to issue an advisory at this time.
Another clipper system will move through Monday night/ Tuesday
morning. Forecast soundings show the lowest several thousand feet to
be above freezing, even all the way into the northeastern portions of
the forecast area. So for snow, the wave should have little impact
with regards to wintry weather in the forecast area and we should see
just rain or perhaps a rain/snow mix in our northern zones.
The rest of the forecast looks quiet regarding precipitation. An
upper level ridge will spread east with low level flow out of the
south. This will help temperatures soar to well above normal levels
by Thursday into Friday. Highs may be in the 70s in parts of the
forecast area Thursday and potentially into Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 544 PM CST SAT FEB 13 2016
Widespread VFR ceilings around 5k ft agl across the region. A nw-se
oriented band of snow is developing from central IA and will stream
through northeast MO overnight with KIRK near the western edge of any
accumulating snow.
To the south expect to see MVFR ceilings form across west central MO
during the pre-dawn hours with areas of freezing drizzle developing.
May even see some sleet mixed in. The area of freezing drizzle should
expand towards central MO by late morning. Further north temperatures
will be cold enough for mainly snow across north central into
northeast MO.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...Winter Weather Advisory from 9 PM this evening to 6 PM CST
Sunday for MOZ008-017-025-033.
&&
$$
DISCUSSION...CDB
AVIATION...MJ
[top]
Area Forecast Discussion
National Weather Service SPRINGFIELD MO
548 PM CST SAT FEB 13 2016
.SHORT TERM...(This Evening through Sunday)
Issued at 0217 PM CST SAT Fib 13 2016
Cold and dry air has invaded much of the Missouri Ozarks region this
afternoon. There are some areas across central Missouri that has
barely reached 20 degrees. The main story for tonight into early
tomorrow will be the threat of a light wintry mix and freezing
drizzle. The latest Hi-Res forecast models all indicate very light
precis to begin to develop between midnight and 3 am across
western and southern Missouri. The latest RUC and HRRR even shows
some convective like precis which indicates pockets of sleet
possible.
The overall message for late tonight into tomorrow morning is we
are expecting only very light amounts of a light wintry mix but
could be impacts on roads and travel in the morning. Ground and
road temperatures have had time to cool down over the past 24
hours. The freezing line will settle somewhere near the Missouri
and Kansas border tonight before it begins to retreat eastward
during the morning hours. There will be very light precis falling
across the Missouri Ozarks with the better potential for higher
amounts across the eastern Ozarks. Freezing drizzle and some light
sleet is expected across the western half of the area and a wintry
mix with some light snow is expected across the eastern half of
the area early on. This will slowly transition to just a cold
light rain or drizzle late tomorrow morning into the early
afternoon from west to east.
We will issue a winter weather advisory for light amounts and
possible travel impacts in the morning. Like what we saw a few
weeks ago...it does not take much freezing drizzle to cause big
travel problems in the Ozarks region. All areas in the advisory
area can expect a very light glaze of ice possible. A dusting of
light sleet or light snow can be expected east of Highway 65 with
up to an inch of snow possible from the Highway 63 corridor and
eastward. Most area will warm up above freezing by Sunday
afternoon with some areas out across far western Missouri near 50.
.LONG TERM...(Sunday Night through Saturday)
Issued at 0217 PM CST SAT Fib 13 2016
There may be some fog developing late Sunday night into Monday
morning. This will need to be watched because temperatures again
may be around or slightly below freezing. The best potential for
fog will be along and south of the I-44 corridor across southern
Missouri.
Milder temperatures return on Monday. A quick moving upper level
system across the Midwest on Tuesday may bring a few more clouds
and a slight chance of showers across central Missouri and the
eastern Ozarks. Decent upper Level ridging will develop across
the central U.S. for the middle and end of next week. This will
allow for way above average temperatures for the region. Highs
will be in the 60s and possible lower 70s. A preview of Spring is
coming next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 0535 PM CST SAT Fib 13 2016
Flight conditions are terminals across the Ozarks will see VFR
conditions into this evening. Conditions will deteriorate towards
midnight as a winter storm system moves into the region. Ceilings
will fall to MVFR with limitations to visibilities also dropping
to MVFR levels.
Low level wind shear will impact aerodromes after midnight through
sunrise as the winter system moves through the area.
Freezing and frozen precipitation will impact the region after
midnight and through sunrise. While precipitation will continuethrough
the morning, slowly improving flight conditions are expected
Sunday afternoon into Sunday evening.
&&
.SGF Watches/Warnings/Advisories...
MO...Winter Weather Advisory from midnight tonight to noon CST Sunday
for MOZ055>058-066>071-077>083-088>098-101>106.
KS...NONE.
&&
$$
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...Hatch
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1150 PM CST THU FEB 11 2016
.UPDATE:
Issued at 859 PM CST Thu Feb 11 2016
Have made some minor adjustments to snowfall based on this
evening`s radar and satellite trends. Water vapor is showing a mid
level vort max currently dropping southeastward out of eastern
Nebraska into northwestern Missouri with a deformation axis
extending from northeast Missouri into west central Iowa. It is
taking some time for the snow to overtake the dry air in the low
levels, so only reports of snow so far in the CWA have flurries
over northeast Missouri. Do think the accumulating snow currently
over Iowa will move into northeast Missouri and west central
Illinois shortly. It still appears the the intensity of the
snowfall will weaken as it moves southeast per the recent runs of
the the RAP. Do not expect much accumulation of snow as far south
at I-70 before midnight...so have shifted the 1 inch totals
slightly northward into northeast Missouri and west central
Illinois with lesser amounts to the south. It still will be a cold
night, so even light snowfall amounts could impact travel. Also
watching second area of radar returns over western Missouri which
has only one or two reports of light snow with it. Any snow
accumulations with it should be light as it moves across the
southern CWA over the next few hours.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 1230 PM CST Thu Feb 11 2016
A northwest flow shortwave now dropping southeastward into western
SD will move quickly through our area tonight. Light snow will
spread southeastward into northeast MO early this evening, then
through the St Louis metro area around midnight. Still looking like
a quick shot of dry, powdery snow with most places picking up to 1
inch of accumulation, but there may be a narrow band of 1-2 inches
extending from near IRK southeast through the St Louis metro area.
Latest NAM and HRRR model runs have the band a little further west
than previous model runs. Most of the accumulating snow should
shift southeast of our forecast area by 12Z Friday. Low
temperatures will be similar to the previous night, and around 5
degrees below normal.
GKS
.LONG TERM: (Friday through Next Thursday)
Issued at 316 PM CST Thu Feb 11 2016
A strong cold front will move southeastward through our forecast
area on Friday with strengthening winds as the surface pressure
gradient tightens as a strong 1040-1045 mb surface high builds
southeastward into the area from the northern Plains behind the cold
front. Temperatures may begin to fall in northeast MO behind the
front already by Friday afternoon. Much colder temperatures are
expected for Friday night and Saturday with wind chills down to
around 10 below zero late Friday night and early Saturday morning
across northeast MO and west central IL. Snow should spread
southeastward into at least northeast MO and west central IL late
Saturday night as low-mid level warm air advection increases ahead
of an approaching northern stream shortwave. It still appears that
the ECMWF model is a little too quick bringing precipitation into
our forecast area already be Saturday afternoon and evening with an
initially very dry boundary layer on the backside of the surface
ridge. The better chance of precipitation should occur on Sunday as
a southwesterly low level jet brings increasing low level moisture
into our area ahead of the shortwave. It is too early to pin down
exact snow totals, but it initially appears that 2-4 inches is
possible across northeast MO and west central IL with lesser amounts
of 1-2 inches further south for Saturday night and Sunday. Another
round of precipitation is expected, mainly on Monday, as a southern
stream shortwave and associated surface low pass south of our area.
This precipitation should be confined mainly to southeast MO and
southwest IL. With temperatures trending up as we head into the
next work week there may also be precipitation type issues with a
mix of snow, sleet and rain possible. Will keep the rest of the
forecast dry with a warming trend, although the ECMWF model does
depict some weaker weather systems bringing a brief period or two of
light QPF to our area. The GFS model is dry for the remainder of
the period after Monday with a dry cold frontal passage on Tuesday
afternoon and evening. Both the GFS and ECMWF models depict a warm
weather pattern by Thursday with upper level ridging over the region
along with strong s-swly low level winds likely leading to well
above normal temperatures.
GKS
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1149 PM CST Thu Feb 11 2016
Snow will continue to move quickly across the area during the
overnight hours reducing visibilities to MVFR or possibly IFR at
times. The snow will move into the St. Louis area terminals in the
next hour and out by 09-11Z. The snow will also move out of KUIN
and KCOU by 06-08Z. Snow accumulations of up to 1 inch are
possible. Then MVFR ceilings are expected to persist through the
morning hours before drier air moves in and allows VFR conditions
to develop.
Specifics for KSTL: An area of snow is expected to move into the
terminal between 06-07Z and move out by 10Z. Any snow
accumulations are expected to be less than an inch. Then MVFR
ceilings are expected to persist through the morning hours before
drier air moves in and allows VFR conditions to develop.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
930 AM MST FRI FEB 12 2016
.UPDATE...
WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS SHOW A RIDGE AXIS OVER
THE GREAT BASIN AND NORTHERN ROCKIES WITH A 500MB HEIGHT IN EXCESS
OF 570DAM OVER SOUTH CENTRAL MT. COLD UPPER LOW DROPPING INTO THE
NORTH CENTRAL CONUS HAS ALLOWED FOR SOME COLDER LOW LEVEL AIR AND
EAST WINDS TO PUSH INTO OUR CWA SINCE LAST NIGHT...UNDERCUTTING
WHAT IS A RATHER STRONG RIDGE ALOFT. MOIST OVERRUNNING OF THIS
SHALLOW COLDER AIRMASS HAS ALLOWED FOR AREAS OF LIGHT PCPN IN THE
FORM OF RAIN/SNOW TO DEVELOP SINCE LAST NIGHT. LATEST RADAR TRENDS
SUGGEST AN EASTWARD MOVEMENT OF THE PCPN ALREADY...AND LOOKS LIKE
OUR WESTERN FOOTHILLS WILL BE MAINLY DRY FROM THIS POINT ON AS
BAROCLINITY SHIFTS EAST. HAVE LOWERED POPS FOR OUR WEST...
INCLUDING BILLINGS WHICH MAY SEE A LITTLE VERY LIGHT RAIN OR SNOW
THROUGH EARLY AFTERNOON...BUT OTHERWISE THIS IS LOOKING MORE LIKE
A DRY DAY FOR THE BILLINGS METRO AREA. THERE IS STILL POTENTIAL
FOR LIGHT SNOW TO MIX WITH LIGHT FREEZING PCPN OVER OUR EAST
TONIGHT AS A WARM LAYER OVERRUNS THE SHALLOW COLD...WITH BELOW
FREEZING SFC TEMPS LIKELY TO OCCUR ACROSS OUR EAST TONIGHT. WILL
NEED TO MONITOR THIS BUT PCPN SHOULD REMAIN LIGHT AND SOMEWHAT
SPOTTY...REDUCING THE POTENTIAL IMPACTS. TEMPS TODAY WILL HANG IN
THE 30S TO MID 40S ACROSS OUR CENTRAL AND EASTERN PARTS...WITH A
PERSISTENT LIGHT EASTERLY WIND...BUT SHOULD SEE 50S EMERGE ALONG
OUR FOOTHILLS AS DOWNSLOPE WINDS DEVELOP. JKL
&&
.SHORT TERM...VALID FOR TDY AND SAT...
A COUPLE OF SYSTEMS WILL IMPACT THE FORECAST AREA THROUGH THE
SHORT TERM. THE FIRST SYSTEM IS STARTING TO MAKE ITS WAY ACROSS
SOUTHWEST MONTANA AND APPROACHING OUR FAR WESTERN COUNTIES. RADAR
ECHOES ARE INCREASING BUT CLOUD BASES STILL REMAIN FAIRLY HIGH AS
NO PRECIP HAS BEEN REPORTED ACROSS THE LIVINGSTON AND BOZEMAN
AREAS. FURTHER EAST TOWARD THE DAKOTA BORDER...A COLD FRONT BACKED
ITS WAY INTO THAT AREA YESTERDAY AND HAS MADE ITS WAY WESTWARD
PAST BILLINGS EARLY THIS MORNING. SATELLITE IS SHOWING A LOW
STRATUS DECK FROM ABOUT MILES CITY EASTWARD BUT NO PRECIP NOR FOG
HAS BEEN REPORTED. THE HRRR MODEL BRINGS SOME VERY LIGHT SHOWER
ACTIVITY INTO OUR WESTERN AREAS THIS MORNING BUT IT DOESN`T MAKE
IT AS FAR EAST AS BILLINGS. HOWEVER...THE GFS AND ECMWF KEEP
SCATTERED AREAS OF PRECIP ACROSS OUR ENTIRE AREA TODAY WITH THE
BEST CHANCES ACROSS OUR WEST THIS MORNING AND EASTERN ZONES THIS
AFTERNOON AND EVENING. AS A RESULT...WE HAVE REMOVED PRECIP
CHANCES THIS MORNING ACROSS THE EAST AND LOWERED CHANCES JUST A
BIT ELSEWHERE. THERE WILL BE A LARGE CONTRAST WITH TEMPERATURES
TODAY WITH BAKER ONLY SEEING TEMPERATURES AROUND 30 WHILE
LIVINGSTON COULD SEE 50 DEGREES.
FOR SATURDAY...A MUCH STRONGER SYSTEM WITHIN A NORTHWEST FLOW
ALOFT MOVES SOUTHEAST ACROSS OUR AREA DURING THE DAY AND LINGERING
ACROSS OUR FAR EASTERN COUNTIES INTO TONIGHT. WE WILL CONTINUE
WITH A HIGH POP CHANCE ACROSS MOST AREAS THROUGH THE DAY WITH
LIKELY POPS ACROSS CUSTER AND FALLON COUNTIES INTO TONIGHT.
SOUNDINGS FROM MILES CITY TO EKALAKA AND POINTS EAST SHOW THE
POSSIBILITY OF SOME LIGHT FREEZING RAIN AFTER MIDNIGHT TONIGHT SO
AREA ROADS MAY BE SLICK. TEMPERATURES SATURDAY WILL WARM BACK INTO
THE 50S WITH 40S ALONG THE DAKOTA BORDERS. HOOLEY
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
WARM AND ABOVE AVERAGE TEMPERATURES WILL CONTINUE THROUGH NEXT
WEEK AS A RIDGE OF HIGH PRESSURE TO OUR WEST IS STUBBORN TO ERODE.
NOT EXPECTING CONDITIONS TO BE AS WARM AS THIS PAST TUESDAY AND
WEDNESDAY...BUT TEMPERATURES WILL STILL BE IN THE UPPER 50S TO
NEAR 60 IN THE DOWNSLOPING NORTHWEST FLOW.
SEVERAL DISTURBANCES WILL PUSH THROUGH THE AREA DURING THE WEEK.
THE FIRST ONE WILL MOVE THROUGH MONDAY NIGHT THROUGH TUESDAY.
EXPECTING MOSTLY RAIN WITH THIS SYSTEM AS AIR AND GROUND
TEMPERATURES SHOULD STAY ABOVE FREEZING. PRETTY GOOD PRESSURE
RISES BEHIND THIS SYSTEM ALSO BRING ABOUT THE CHANCE FOR SOME
GUSTY CONDITIONS LATE MONDAY THROUGH TUESDAY AFTERNOON. THOUGH
WITH THE BEST PRESSURE RISES APPEARING TO MOVE THROUGH AT NIGHT
WILL NOT ISSUE ANY HIGHLIGHTS AT THIS TIME. IN ADDITION...STRONGEST
MID-LEVEL WINDS LOOK TO STAY MOSTLY WEST OF BILLINGS AND ROUNDUP.
A WEAK WAVE MOVES THROUGH WEDNESDAY BUT LITTLE MOISTURE AND UPPER
LEVEL FORCING SHOULD KEEP SHOWER CHANCES LOW. LAST SYSTEM
APPROACHES FROM THE SOUTHWEST TOWARDS THE LATER PART OF THE WEEK.
BETTER DYNAMICS WITH THIS SYSTEM ARE EXPECTED BUT THE SPLITTING
AND WEAKENING NATURE OF THIS SYSTEM SHOULD JUST ALLOW FOR A SLIGHT
CHANCE OF POPS IN THE PLAINS...WITH MOST OF THE WESTERN TERRAIN
SEEING ANY APPRECIABLE PRECIP. DOBBS
&&
.AVIATION...
MVFR CONDITIONS POSSIBLE TODAY. RAIN/SNOW SHOWERS POSSIBLE THIS
MORNING FROM KLVM TO KMLS...EVENTUALLY SHIFTING TO AREAS EAST OF
KBIL-KSHR FOR THIS EVENING. LIGHT FREEZING RAIN AND PATCHY FOG ARE
POSSIBLE EAST OF KBIL-KSHR TONIGHT. MVFR CONDITIONS THEN POSSIBLE
AT TIMES AGAIN ON SATURDAY ACROSS SOUTHERN MONTANA AND NORTH-
CENTRAL WYOMING. SNOW SHOWERS POSSIBLE SAT MORNING ACROSS SOUTHERN
MT...THEN RAIN SHOWERS POSSIBLE SAT AFTERNOON FOR SOUTHERN MT AND
NORTH-CENTRAL WY. RMS/JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 044 034/052 033/054 038/058 041/059 038/060 037/055
2/O 13/W 23/W 24/W 22/W 11/E 11/E
LVM 057 037/048 034/049 040/055 045/056 041/056 036/052
2/R 04/W 35/W 34/W 32/W 11/N 22/W
HDN 045 029/053 031/054 034/058 037/059 034/060 034/054
3/O 14/W 23/W 24/W 32/W 11/E 11/E
MLS 037 026/050 029/052 033/054 037/054 034/055 033/053
3/S 46/W 21/B 23/W 22/W 11/E 11/E
4BQ 038 028/051 030/050 032/053 037/055 034/059 033/055
3/S 34/W 32/W 24/W 32/W 11/B 11/E
BHK 030 018/043 028/047 028/048 032/049 030/050 029/050
1/E 46/W 31/B 12/W 22/W 11/B 11/E
SHR 046 027/052 027/049 032/054 034/056 032/058 031/054
2/O 13/W 53/W 23/W 22/W 11/B 11/E
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
409 AM MST FRI FEB 12 2016
.SHORT TERM...VALID FOR TDY AND SAT...
A COUPLE OF SYSTEMS WILL IMPACT THE FORECAST AREA THROUGH THE
SHORT TERM. THE FIRST SYSTEM IS STARTING TO MAKE ITS WAY ACROSS
SOUTHWEST MONTANA AND APPROACHING OUR FAR WESTERN COUNTIES. RADAR
ECHOES ARE INCREASING BUT CLOUD BASES STILL REMAIN FAIRLY HIGH AS
NO PRECIP HAS BEEN REPORTED ACROSS THE LIVINGSTON AND BOZEMAN
AREAS. FURTHER EAST TOWARD THE DAKOTA BORDER...A COLD FRONT BACKED
ITS WAY INTO THAT AREA YESTERDAY AND HAS MADE ITS WAY WESTWARD
PAST BILLINGS EARLY THIS MORNING. SATELLITE IS SHOWING A LOW
STRATUS DECK FROM ABOUT MILES CITY EASTWARD BUT NO PRECIP NOR FOG
HAS BEEN REPORTED. THE HRRR MODEL BRINGS SOME VERY LIGHT SHOWER
ACTIVITY INTO OUR WESTERN AREAS THIS MORNING BUT IT DOESN`T MAKE
IT AS FAR EAST AS BILLINGS. HOWEVER...THE GFS AND ECMWF KEEP
SCATTERED AREAS OF PRECIP ACROSS OUR ENTIRE AREA TODAY WITH THE
BEST CHANCES ACROSS OUR WEST THIS MORNING AND EASTERN ZONES THIS
AFTERNOON AND EVENING. AS A RESULT...WE HAVE REMOVED PRECIP
CHANCES THIS MORNING ACROSS THE EAST AND LOWERED CHANCES JUST A
BIT ELSEWHERE. THERE WILL BE A LARGE CONTRAST WITH TEMPERATURES
TODAY WITH BAKER ONLY SEEING TEMPERATURES AROUND 30 WHILE
LIVINGSTON COULD SEE 50 DEGREES.
FOR SATURDAY...A MUCH STRONGER SYSTEM WITHIN A NORTHWEST FLOW
ALOFT MOVES SOUTHEAST ACROSS OUR AREA DURING THE DAY AND LINGERING
ACROSS OUR FAR EASTERN COUNTIES INTO TONIGHT. WE WILL CONTINUE
WITH A HIGH POP CHANCE ACROSS MOST AREAS THROUGH THE DAY WITH
LIKELY POPS ACROSS CUSTER AND FALLON COUNTIES INTO TONIGHT.
SOUNDINGS FROM MILES CITY TO EKALAKA AND POINTS EAST SHOW THE
POSSIBILITY OF SOME LIGHT FREEZING RAIN AFTER MIDNIGHT TONIGHT SO
AREA ROADS MAY BE SLICK. TEMPERATURES SATURDAY WILL WARM BACK INTO
THE 50S...WITH 40S ALONG THE DAKOTA BORDERS. HOOLEY
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
WARM AND ABOVE AVERAGE TEMPERATURES WILL CONTINUE THROUGH NEXT
WEEK AS A RIDGE OF HIGH PRESSURE TO OUR WEST IS STUBBORN TO ERODE.
NOT EXPECTING CONDITIONS TO BE AS WARM AS THIS PAST TUESDAY AND
WEDNESDAY...BUT TEMPERATURES WILL STILL BE IN THE UPPER 50S TO
NEAR 60 IN THE DOWNSLOPING NORTHWEST FLOW.
SEVERAL DISTURBANCES WILL PUSH THROUGH THE AREA DURING THE WEEK.
THE FIRST ONE WILL MOVE THROUGH MONDAY NIGHT THROUGH TUESDAY.
EXPECTING MOSTLY RAIN WITH THIS SYSTEM AS AIR AND GROUND
TEMPERATURES SHOULD STAY ABOVE FREEZING. PRETTY GOOD PRESSURE
RISES BEHIND THIS SYSTEM ALSO BRING ABOUT THE CHANCE FOR SOME
GUSTY CONDITIONS LATE MONDAY THROUGH TUESDAY AFTERNOON. THOUGH
WITH THE BEST PRESSURE RISES APPEARING TO MOVE THROUGH AT NIGHT
WILL NOT ISSUE ANY HIGHLIGHTS AT THIS TIME. IN ADDITION...STRONGEST
MID-LEVEL WINDS LOOK TO STAY MOSTLY WEST OF BILLINGS AND ROUNDUP.
A WEAK WAVE MOVES THROUGH WEDNESDAY BUT LITTLE MOISTURE AND UPPER
LEVEL FORCING SHOULD KEEP SHOWER CHANCES LOW. LAST SYSTEM
APPROACHES FROM THE SOUTHWEST TOWARDS THE LATER PART OF THE WEEK.
BETTER DYNAMICS WITH THIS SYSTEM ARE EXPECTED BUT THE SPLITTING
AND WEAKENING NATURE OF THIS SYSTEM SHOULD JUST ALLOW FOR A SLIGHT
CHANCE OF POPS IN THE PLAINS...WITH MOST OF THE WESTERN TERRAIN
SEEING ANY APPRECIABLE PRECIP. DOBBS
&&
.AVIATION...
MVFR CONDITIONS POSSIBLE AT ALL TERMINALS EXCEPT KSHR THROUGH 18Z
TOMORROW AS A DISTURBANCE SLIDES ACROSS THE AREA. MOSTLY RAIN IS
EXPECTED THOUGH SNOW SHOWERS ARE POSSIBLE AT KLVM...KMLS...AND
KBHK. MVFR CONDITIONS POSSIBLE AT KSHR FROM 18Z TO 00Z. CONDITIONS
BEGIN TO CLEAR OUT BY 21 TO 00Z TOMORROW FROM WEST TO EAST. DOBBS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 045 034/052 033/054 038/058 041/059 038/060 037/055
3/W 13/W 23/W 24/W 22/W 11/E 11/E
LVM 055 037/048 034/049 040/055 045/056 041/056 036/052
3/W 04/W 35/W 34/W 32/W 11/N 22/W
HDN 045 029/053 031/054 034/058 037/059 034/060 034/054
3/W 14/W 23/W 24/W 32/W 11/E 11/E
MLS 038 026/050 029/052 033/054 037/054 034/055 033/053
2/W 46/W 21/B 23/W 22/W 11/E 11/E
4BQ 039 028/051 030/050 032/053 037/055 034/059 033/055
2/W 34/W 32/W 24/W 32/W 11/B 11/E
BHK 030 018/043 028/047 028/048 032/049 030/050 029/050
1/E 46/W 31/B 12/W 22/W 11/B 11/E
SHR 047 027/052 027/049 032/054 034/056 032/058 031/054
2/W 13/W 53/W 23/W 22/W 11/B 11/E
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
919 PM CST SAT FEB 13 2016
.UPDATE...
ISSUED AT 910 PM CST SAT FEB 13 2016
SOME WILD WEATHER IN WESTERN SOUTH DAKOTA THIS EVENING WITH
LIGHTNING...LOCALIZED HEAVY RAIN AND SEVERAL WIND GUSTS 45 TO 57
MPH. THE SHORTWAVE TROF TRACKS ACROSS THE NORTHERN PLAINS INTO
IOWA/SOUTHERN WI/IL THROUGH SUNDAY. THE MAIN AREA OF SNOW WILL BE
FROM SD INTO MN/IA/IL THROUGH MORNING. OVERALL DID NOT MAKE ANY
SIGNIFICANT CHANGES TO THE LIGHT SNOW AMOUNTS. NORTHEAST NEBRASKA
AND WESTERN CENTRAL IOWA SHOULD GET CLIPPED BY THE LIGHT SNOW WITH
AN INCH OR SO POSSIBLE. A FEW EARLIER HRRR RUNS WERE HINTING AT
POSSIBLE BANDING OF LIGHT SNOW FARTHER SOUTH...HOWEVER THE LATEST
HRRR DID NOT HAVE THIS. OUR OAX 00Z SOUNDING WAS SATURATED BETWEEN
H800 AND H850MB...WITH DRY AIR BELOW THIS. LIFT INCREASES AND
AROUND 09Z/10Z COULD SEE FLURRIES OR A DUSTING TOWARD TO THE
PLATTE RIVER/METRO AREA.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 306 PM CST SAT FEB 13 2016
PRECIPITATION CHANCES WITH A COUPLE OF SHORTWAVES DIVING THROUGH THE
PLAINS TONIGHT AND MONDAY NIGHT...AND WARMING TEMPERATURES...ARE THE
PRIMARY FORECAST CONCERNS.
STEEPENING NORTHWEST MID LEVEL FLOW IS EXPECTED OVER THE NEXT COUPLE
OF DAYS AS SHORTWAVES ROLLING THROUGH THAT FLOW TONIGHT AND MONDAY
NIGHT CARVE OUT A DEEPER TROUGH IN THE EASTERN STATES. EACH OF THOSE
SHORTWAVES WILL BRING PRECIPITATION CHANCES TO THE PLAINS...BUT
TRACKS OF BOTH LOOK TO FAVOR AREAS TO OUR NORTH AND NORTHEAST FOR
BEST POTENTIAL FOR ACCUMULATING SNOWS.
TONIGHTS SHORTWAVE WAS MOVING THROUGH EASTERN MONTANA THIS AFTERNOON
AND WILL PUSH THROUGH OUR AREA LATE TONIGHT AND SUNDAY MORNING.
SOUTH TO SOUTHEAST LOW LEVEL FLOW WILL INCREASE AHEAD OF
SYSTEM...AND ALONG WITH ABUNDANT CLOUD COVER...EXPECT TEMPERATURES
TO SLOWLY RISE OVERNIGHT FROM THE TEENS OR LOWER 20S TO THE 25 TO 30
DEGREE RANGE BY SUNRISE. PRECIPITATION-WISE...ALREADY SEEING SOME
MID LEVEL REFLECTIVITIES SHOWING UP ON AREA RADARS AS WING OF MID
LEVEL WARM ADVECTION BEGINS. EXPECT THAT AREA TO EXPAND IN COVERAGE
AS WE HEAD TOWARD MIDNIGHT WHEN LAYERED FRONTOGENETICAL FORCING IS
MAXIMIZED. THAT SHIFTS TO THE EAST BY 12Z...TAKING BULK OF
PRECIPITATION WITH IT. SO OUR NORTHEAST COUNTIES HAVE THE BEST
CHANCE FOR ACCUMULATING SNOWS...BUT STILL SHOULD TOTAL JUST AN INCH
OR SO THERE.
BEHIND SHORTWAVE...MODEST MIXING REGIME WILL SET UP AS NORTHWEST
WINDS DOMINATE AND SOME DECREASE IN CLOUD COVER IS EXPECTED. SHOULD
SEE SOME 40S FOR MUCH OF THE CWA SUNDAY AFTERNOON WITH 30S HOLDING
IN THE NORTHEAST. WESTERLY LOW LEVEL WIND COMPONENT WILL REMAIN INTO
MONDAY BEFORE NEXT SHORTWAVE BEGINS TO EJECT TOWARD THE AREA MONDAY
NIGHT. THUS TEMPERATURES WILL REMAIN RELATIVELY MILD AS COMPARED TO
RECENT TEMPS...WITH LOWS IN THE 20S AND HIGHS AGAIN IN THE 40S
MONDAY AFTERNOON...AND PERHAPS WARMER IN THE SOUTH WHERE NO
SNOWCOVER EXISTS AND SOUTHWEST WINDS KICK IN MONDAY AFTERNOON.
SIMILAR SCENARIO IS EXPECTED MONDAY NIGHT AS TONIGHT WITH SHORTWAVE
TRACK FOCUSING BEST PRECIP CHANCES TO OUR NORTH AND EAST. HOWEVER A
BETTER INITIAL MOISTURE PROFILE SUGGESTS A BROADER AREA OF
PRECIPITATION WILL RESULT WHEN WARM ADVECTION OVERSPREADS THE AREA
MONDAY EVENING. HAVE FAIRLY HIGH CHANCE POPS FOR MUCH OF EASTERN
NEBRASKA THEN...WITH AREA SHIFTING INTO WESTERN IOWA AFTER
MIDNIGHT. PRECIPITATION TYPE WILL ALSO BE AN ISSUE WITH MUCH
WARMER TEMPERATURE PROFILE THAN TONIGHT. FORECAST SOUNDINGS
SUGGEST A CHANCE FOR MIXED PRECIPITATION FOR ALL BUT FAR NORTHEAST
NEBRASKA AND WEST CENTRAL IOWA. WILL MAINTAIN A CHANCE FOR RAIN OR
SNOW MOST AREAS UNTIL FINER DETAILS CAN BE WORKED OUT. AND WITH
THE POTENTIAL MIX EXPECTED...AND RELATIVELY MILD TEMPS
OVERNIGHT...SNOWFALL ACCUMULATION FOR MOST AREAS WILL BE MINIMAL.
NORTHWEST LOW LEVEL FLOW TUESDAY AFTERNOON BEHIND SHORTWAVE AGAIN
OFFERS LITTLE IN THE WAY OF COOLING WITH NEUTRAL TEMPERATURE
ADVECTION NOTED. THUS HIGHS AGAIN IN THE 40S FOR MUCH OF EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH 30S IN THE NORTHEAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM CST SAT FEB 13 2016
A WARMING TREND IS EXPECTED THROUGH THE REST OF THE WORK WEEK WITH
RISING MID LEVEL HEIGHTS THE HIGHLIGHT OF THE FORECAST.
NORTHWEST MID LEVEL FLOW WILL BE REPLACED BY MODEST RIDGING BY
WEDNESDAY NIGHT AS TROUGH DIGS JUST OFF THE WEST COAST AND EASTERN
TROUGH SWINGS INTO THE MID ATLANTIC STATES. GRADUALLY WARMING 850
TEMPERATURES FROM SUB ZERO TUESDAY AFTERNOON TO THE MID TEENS
THURSDAY EVENING DEMONSTRATE THE MAGNITUDE OF BACKGROUND
WARMING...SUGGESTING SURFACE TEMPERATURES INTO THE 50S LOOK ON TRACK
BY THEN. PLENTY OF SUNSHINE SHOULD HELP AS WELL.
BY FRIDAY...A SHORTWAVE RIDING THROUGH THE NORTHERN PLAINS WILL PUSH
A TROUGH/COOL FRONT THROUGH OUR REGION...BUT PRECIPITATION WILL
REMAIN WELL TO OUR NORTH. AND ONLY BRIEF COOLING IS FORECAST FRIDAY
NIGHT BEFORE WARM ADVECTION AGAIN KICKS IN FOR SATURDAY.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 515 PM CST SAT FEB 13 2016
VFR CONDITIONS THROUGH MOST OF THE PERIOD...EXCEPT FOR A PERIOD OF
MVFR CEILINGS WITH SOME LIGHT SNOW AT KOFK 07-11Z AND 09-13Z AT
KOMA. SOUTHEAST WINDS GREATER THAN 12 KNOTS INITIALLY...WITH GUSTS
UP TO 22 TO 28 KNOTS...EVENTUALLY BECOMING NORTHWEST THROUGH TIME.
SNOWFALL AMOUNTS AT BOTH KOFK/KOMA MAYBE UP TO ONE HALF INCH.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...ZAPOTOCNY
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1115 AM CST FRI FEB 12 2016
.SYNOPSIS...
ISSUED AT 320 AM CST FRI FEB 12 2016
ARCTIC HIGH PRESSURE CONTINUES TO BUILD SOUTH FROM THE DAKOTAS AND
MINNESOTA INTO NEBRASKA. AT 08Z...THE LEADING EDGE OF THE FRONT WAS
ANALYZED FROM NEAR PINE RIDGE SOUTH DAKOTA THROUGH NORTH PLATTE THEN
SOUTHEAST ACROSS NCTRL KS. A LARGE AREA OF STRATUS EXTENDS NORTH AND
EAST OF THE FRONT. NO INDICATION YET OF FOG DEVELOPMENT IN WESTERN
NEBRASKA. THE RAP AND HRRR MODELS BOTH SUGGEST DEVELOPMENT NEAR THE
WESTERN EDGE OF THE STRATUS ALONG ADVANCING COLD FRONT IN THE
WESTERN SANDHILLS INTO SOUTHWEST NEBRASKA THIS MORNING. TEMPERATURES
RANGING FROM 26 TO 32 ACROSS WESTERN NEBRASKA...WITH COLDER TEENS
REPORTED IN EASTERN SOUTH DAKOTA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CST FRI FEB 12 2016
THE MAIN FORECAST CONCERNS WILL BE THE BACKDOOR COLD FRONT FORECAST
TO PUSH INTO THE WESTERN NEBRASKA PANHANDLE AND NORTHEAST COLORADO
BY LATE THIS AFTERNOON AND ITS EFFECTS ON HIGH TEMPERATURES ACROSS
WESTERN NEBRASKA TODAY. ONLY MINOR ADJUSTMENTS TO HIGHS TODAY. NEAR
38 IN THE SWRN TIER OF COUNTIES IN CLOSER PROXIMITY TO THE FRONT.
LOWER 20S IN BOYD AND NERN HOLT COUNTY WHERE TEMPERATURES WILL
ACTUALLY HOLD STEADY THROUGH THE DAY FROM THIS MORNINGS LOWS.
FOR TONIGHT...A WARM FRONT WILL BEGIN TO PUSH EAST INTO WESTERN
NEBRASKA. WITH WIDESPREAD STRATUS ALREADY IN PLACE...CONDITIONS WILL
BE FAVORABLE FOR PATCHY FREEZING DRIZZLE TO BEGIN DEVELOPING DUE TO
A LACK OF ICE CRYSTALS INTRODUCED FROM ALOFT. THE PATCHY FREEZING
DRIZZLE FORECAST TO BEGIN LATE THIS EVENING MAINLY WEST OF A LINE
FROM GORDON THROUGH NORTH PLATTE...ADVANCING FURTHER EAST TO NEAR
VALENTINE THROUGH BROKEN BOW BY LATE TONIGHT. WHERE SOME SATURATION
DOES EXIST UP INTO THE DENDRITIC LAYER...A 20 TO 30 PERCENT CHANCE
FOR LIGHT SNOW ACROSS THE EASTERN TWO THIRDS OF THE FORECAST AREA.
THERE WILL BE AN AREA IN BETWEEN WHERE FREEZING DRIZZLE AND LIGHT
SNOW MAY BOTH OCCUR...MAINLY ACROSS WESTERN CHERRY COUNTY SOUTH
THROUGH THE CENTRAL SANDHILLS INTO SOUTHWESTERN NEBRASKA. SINCE ONLY
A SMALL AMOUNT OF FREEZING DRIZZLE CAN IMPACT TRAVEL...WILL CONTINUE
TO HIGHLIGHT THE POTENTIAL FOR THE LIGHT FREEZING DRIZZLE TONIGHT
INTO SATURDAY MORNING IN A SPECIAL WEATHER STATEMENT AND THE
HAZARDOUS WEATHER OUTLOOK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CST FRI FEB 12 2016
12Z SATURDAY AND BEYOND. SATURDAY WILL BE ANOTHER TRANSITION DAY AS
AN ELEVATED WARM FRONT LIFTS EAST ACROSS THE SANDHILLS.
HOWEVER...OUTSIDE OF THE EASTERN PANHANDLE AND WESTERN
SANDHILLS...ALL OTHER LOCATIONS WILL CONTINUE TO SEE TEMPERATURES
BELOW FREEZING. THIS WILL FACILITATE A CONTINUED MENTION
OF FREEZING DRIZZLE INTO THE EARLY AFTERNOON AS SOUNDINGS
INDICATE SATURATION BELOW THE DGZ WHERE THERE/S WEAK OMEGA. WHERE
SUFFICIENT SATURATION IS SHOWN IS ACROSS OUR NORTHEASTERN ZONES
WHERE LIGHT SNOW IS FORECAST. THE MODELS ONLY SUGGEST A FEW
HUNDRETHS AT MOST QPF...AND WITH VERY WEAK LIFT SEEN...SNOW
ACCUMULATIONS SHOULD ONLY AMOUNT TO A FEW TENTHS AT BEST.
ADDITIONAL SNOW CHANCES ARE POSSIBLE ACROSS OUR FAR NORTHERN
ZONES SATURDAY EVENING INTO EARLY SUNDAY AS A FAST MOVING MID-
LEVEL DISTURBANCE DROPS SOUTHEAST ACROSS THE DAKOTAS. THE MODELS
CONTINUE TO INDICATE THE BEST FORCING AND MOISTURE NORTH OF THE
BORDER ACROSS THE DAKOTAS...SO ONLY A FEW TENTHS ADDITIONAL SNOW
ACCUMULATIONS ARE EXPECTED.
WARMING TEMPERATURES ARE FORECAST FOR SUNDAY AS H85 T/S ARE SHOWN TO
CLIMB BACK ABOVE 0C FOR THE ENTIRE CWA. HIGHS IN THE 40S ARE
FORECAST. SUNDAY EVENING...THE MODELS DEPICT A FAST MOVING MID-
LEVEL DISTURBANCE DROPPING SOUTHEAST ACROSS THE HIGH PLAINS
OF COLORADO INTO WESTERN KANSAS. AT THIS POINT...FORCING IS TOO
WEAK WITHIN THE CWA FOR PRECIPITATION...BUT THE 00Z MODELS HAVE
TRENDED SLIGHTLY EAST WITH THE PROJECTED QPF. WILL NEED TO
MONITOR CLOSELY AS AT THIS POINT WE HAVE A DRY FORECAST GOING.
INTO EARLY NEXT WEEK A GRADUAL WARMING TREND IS FORECAST AS
RIDGING BUILDS EAST INTO THE WESTERN ROCKIES AND A TROUGH DEEPENS
INTO THE SOUTHEASTERN STATES. NORTHWEST FLOW ALOFT WILL USHER
ANOTHER DISTURBANCE ACROSS THE REGION LATE MONDAY INTO
TUESDAY...BUT THE MODELS LARGELY DISAGREE IN THE LOCATION OF THE
BEST FORCING...WILL KEEP THE INHERITED DRY FORECAST GOING FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1115 AM CST FRI FEB 12 2016
AS WIND SWINGS AROUND TO THE SOUTHEAST...THE PROBABILITY OF CEILING
BELOW 1000 FEET WILL INCREASE LATE THIS AFTERNOON AND INTO TONIGHT.
IN ADDITION TO THE LOW CEILINGS...THERE IS A RISK OF FREEZING
DRIZZLE AND LOW LEVEL ICING AFTER 03Z WEST OF AN ANW-BBW LINE. LIGHT
SNOW SHOWERS ARE EXPECTED ALONG AND EAST OF A VTN-LBF LINE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
727 AM CST FRI FEB 12 2016
.SYNOPSIS...
ISSUED AT 320 AM CST FRI FEB 12 2016
ARCTIC HIGH PRESSURE CONTINUES TO BUILD SOUTH FROM THE DAKOTAS AND
MINNESOTA INTO NEBRASKA. AT 08Z...THE LEADING EDGE OF THE FRONT WAS
ANALYZED FROM NEAR PINE RIDGE SOUTH DAKOTA THROUGH NORTH PLATTE THEN
SOUTHEAST ACROSS NCTRL KS. A LARGE AREA OF STRATUS EXTENDS NORTH AND
EAST OF THE FRONT. NO INDICATION YET OF FOG DEVELOPMENT IN WESTERN
NEBRASKA. THE RAP AND HRRR MODELS BOTH SUGGEST DEVELOPMENT NEAR THE
WESTERN EDGE OF THE STRATUS ALONG ADVANCING COLD FRONT IN THE
WESTERN SANDHILLS INTO SOUTHWEST NEBRASKA THIS MORNING. TEMPERATURES
RANGING FROM 26 TO 32 ACROSS WESTERN NEBRASKA...WITH COLDER TEENS
REPORTED IN EASTERN SOUTH DAKOTA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CST FRI FEB 12 2016
THE MAIN FORECAST CONCERNS WILL BE THE BACKDOOR COLD FRONT FORECAST
TO PUSH INTO THE WESTERN NEBRASKA PANHANDLE AND NORTHEAST COLORADO
BY LATE THIS AFTERNOON AND ITS EFFECTS ON HIGH TEMPERATURES ACROSS
WESTERN NEBRASKA TODAY. ONLY MINOR ADJUSTMENTS TO HIGHS TODAY. NEAR
38 IN THE SWRN TIER OF COUNTIES IN CLOSER PROXIMITY TO THE FRONT.
LOWER 20S IN BOYD AND NERN HOLT COUNTY WHERE TEMPERATURES WILL
ACTUALLY HOLD STEADY THROUGH THE DAY FROM THIS MORNINGS LOWS.
FOR TONIGHT...A WARM FRONT WILL BEGIN TO PUSH EAST INTO WESTERN
NEBRASKA. WITH WIDESPREAD STRATUS ALREADY IN PLACE...CONDITIONS WILL
BE FAVORABLE FOR PATCHY FREEZING DRIZZLE TO BEGIN DEVELOPING DUE TO
A LACK OF ICE CRYSTALS INTRODUCED FROM ALOFT. THE PATCHY FREEZING
DRIZZLE FORECAST TO BEGIN LATE THIS EVENING MAINLY WEST OF A LINE
FROM GORDON THROUGH NORTH PLATTE...ADVANCING FURTHER EAST TO NEAR
VALENTINE THROUGH BROKEN BOW BY LATE TONIGHT. WHERE SOME SATURATION
DOES EXIST UP INTO THE DENDRITIC LAYER...A 20 TO 30 PERCENT CHANCE
FOR LIGHT SNOW ACROSS THE EASTERN TWO THIRDS OF THE FORECAST AREA.
THERE WILL BE AN AREA IN BETWEEN WHERE FREEZING DRIZZLE AND LIGHT
SNOW MAY BOTH OCCUR...MAINLY ACROSS WESTERN CHERRY COUNTY SOUTH
THROUGH THE CENTRAL SANDHILLS INTO SOUTHWESTERN NEBRASKA. SINCE ONLY
A SMALL AMOUNT OF FREEZING DRIZZLE CAN IMPACT TRAVEL...WILL CONTINUE
TO HIGHLIGHT THE POTENTIAL FOR THE LIGHT FREEZING DRIZZLE TONIGHT
INTO SATURDAY MORNING IN A SPECIAL WEATHER STATEMENT AND THE
HAZARDOUS WEATHER OUTLOOK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CST FRI FEB 12 2016
12Z SATURDAY AND BEYOND. SATURDAY WILL BE ANOTHER TRANSITION DAY AS
AN ELEVATED WARM FRONT LIFTS EAST ACROSS THE SANDHILLS.
HOWEVER...OUTSIDE OF THE EASTERN PANHANDLE AND WESTERN
SANDHILLS...ALL OTHER LOCATIONS WILL CONTINUE TO SEE TEMPERATURES
BELOW FREEZING. THIS WILL FACILITATE A CONTINUED MENTION
OF FREEZING DRIZZLE INTO THE EARLY AFTERNOON AS SOUNDINGS
INDICATE SATURATION BELOW THE DGZ WHERE THERE/S WEAK OMEGA. WHERE
SUFFICIENT SATURATION IS SHOWN IS ACROSS OUR NORTHEASTERN ZONES
WHERE LIGHT SNOW IS FORECAST. THE MODELS ONLY SUGGEST A FEW
HUNDRETHS AT MOST QPF...AND WITH VERY WEAK LIFT SEEN...SNOW
ACCUMULATIONS SHOULD ONLY AMOUNT TO A FEW TENTHS AT BEST.
ADDITIONAL SNOW CHANCES ARE POSSIBLE ACROSS OUR FAR NORTHERN
ZONES SATURDAY EVENING INTO EARLY SUNDAY AS A FAST MOVING MID-
LEVEL DISTURBANCE DROPS SOUTHEAST ACROSS THE DAKOTAS. THE MODELS
CONTINUE TO INDICATE THE BEST FORCING AND MOISTURE NORTH OF THE
BORDER ACROSS THE DAKOTAS...SO ONLY A FEW TENTHS ADDITIONAL SNOW
ACCUMULATIONS ARE EXPECTED.
WARMING TEMPERATURES ARE FORECAST FOR SUNDAY AS H85 T/S ARE SHOWN TO
CLIMB BACK ABOVE 0C FOR THE ENTIRE CWA. HIGHS IN THE 40S ARE
FORECAST. SUNDAY EVENING...THE MODELS DEPICT A FAST MOVING MID-
LEVEL DISTURBANCE DROPPING SOUTHEAST ACROSS THE HIGH PLAINS
OF COLORADO INTO WESTERN KANSAS. AT THIS POINT...FORCING IS TOO
WEAK WITHIN THE CWA FOR PRECIPITATION...BUT THE 00Z MODELS HAVE
TRENDED SLIGHTLY EAST WITH THE PROJECTED QPF. WILL NEED TO
MONITOR CLOSELY AS AT THIS POINT WE HAVE A DRY FORECAST GOING.
INTO EARLY NEXT WEEK A GRADUAL WARMING TREND IS FORECAST AS
RIDGING BUILDS EAST INTO THE WESTERN ROCKIES AND A TROUGH DEEPENS
INTO THE SOUTHEASTERN STATES. NORTHWEST FLOW ALOFT WILL USHER
ANOTHER DISTURBANCE ACROSS THE REGION LATE MONDAY INTO
TUESDAY...BUT THE MODELS LARGELY DISAGREE IN THE LOCATION OF THE
BEST FORCING...WILL KEEP THE INHERITED DRY FORECAST GOING FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 726 AM CST FRI FEB 12 2016
CURRENT IFR CEILINGS WITH VSBY BTWN 1 AND 3SM AT KVTN FCST TO
IMPROVE TO P6SM OVC009 AFTER 15Z...THEN MVFR AFTER 17Z. AFTER
06Z/13TH A TEMPO ADDED FOR LIGHT SNOW. AT KLBF MVFR CEILING FCST
TODAY. FOR TONIGHT...IFR CEILINGS AFTER 03Z WITH THE POSSIBILITY
FOR PATCHY FZDZ. DID NOT INCLUDE IN TAF ATTM AS CONFIDENCE AND
COVERAGE TOO LOW TO INCLUDE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
320 AM CST FRI FEB 12 2016
.SYNOPSIS...
ISSUED AT 320 AM CST FRI FEB 12 2016
ARCTIC HIGH PRESSURE CONTINUES TO BUILD SOUTH FROM THE DAKOTAS AND
MINNESOTA INTO NEBRASKA. AT 08Z...THE LEADING EDGE OF THE FRONT WAS
ANALYZED FROM NEAR PINE RIDGE SOUTH DAKOTA THROUGH NORTH PLATTE THEN
SOUTHEAST ACROSS NCTRL KS. A LARGE AREA OF STRATUS EXTENDS NORTH AND
EAST OF THE FRONT. NO INDICATION YET OF FOG DEVELOPMENT IN WESTERN
NEBRASKA. THE RAP AND HRRR MODELS BOTH SUGGEST DEVELOPMENT NEAR THE
WESTERN EDGE OF THE STRATUS ALONG ADVANCING COLD FRONT IN THE
WESTERN SANDHILLS INTO SOUTHWEST NEBRASKA THIS MORNING. TEMPERATURES
RANGING FROM 26 TO 32 ACROSS WESTERN NEBRASKA...WITH COLDER TEENS
REPORTED IN EASTERN SOUTH DAKOTA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CST FRI FEB 12 2016
THE MAIN FORECAST CONCERNS WILL BE THE BACKDOOR COLD FRONT FORECAST
TO PUSH INTO THE WESTERN NEBRASKA PANHANDLE AND NORTHEAST COLORADO
BY LATE THIS AFTERNOON AND ITS EFFECTS ON HIGH TEMPERATURES ACROSS
WESTERN NEBRASKA TODAY. ONLY MINOR ADJUSTMENTS TO HIGHS TODAY. NEAR
38 IN THE SWRN TIER OF COUNTIES IN CLOSER PROXIMITY TO THE FRONT.
LOWER 20S IN BOYD AND NERN HOLT COUNTY WHERE TEMPERATURES WILL
ACTUALLY HOLD STEADY THROUGH THE DAY FROM THIS MORNINGS LOWS.
FOR TONIGHT...A WARM FRONT WILL BEGIN TO PUSH EAST INTO WESTERN
NEBRASKA. WITH WIDESPREAD STRATUS ALREADY IN PLACE...CONDITIONS WILL
BE FAVORABLE FOR PATCHY FREEZING DRIZZLE TO BEGIN DEVELOPING DUE TO
A LACK OF ICE CRYSTALS INTRODUCED FROM ALOFT. THE PATCHY FREEZING
DRIZZLE FORECAST TO BEGIN LATE THIS EVENING MAINLY WEST OF A LINE
FROM GORDON THROUGH NORTH PLATTE...ADVANCING FURTHER EAST TO NEAR
VALENTINE THROUGH BROKEN BOW BY LATE TONIGHT. WHERE SOME SATURATION
DOES EXIST UP INTO THE DENDRITIC LAYER...A 20 TO 30 PERCENT CHANCE
FOR LIGHT SNOW ACROSS THE EASTERN TWO THIRDS OF THE FORECAST AREA.
THERE WILL BE AN AREA IN BETWEEN WHERE FREEZING DRIZZLE AND LIGHT
SNOW MAY BOTH OCCUR...MAINLY ACROSS WESTERN CHERRY COUNTY SOUTH
THROUGH THE CENTRAL SANDHILLS INTO SOUTHWESTERN NEBRASKA. SINCE ONLY
A SMALL AMOUNT OF FREEZING DRIZZLE CAN IMPACT TRAVEL...WILL CONTINUE
TO HIGHLIGHT THE POTENTIAL FOR THE LIGHT FREEZING DRIZZLE TONIGHT
INTO SATURDAY MORNING IN A SPECIAL WEATHER STATEMENT AND THE
HAZARDOUS WEATHER OUTLOOK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CST FRI FEB 12 2016
12Z SATURDAY AND BEYOND. SATURDAY WILL BE ANOTHER TRANSITION DAY AS
AN ELEVATED WARM FRONT LIFTS EAST ACROSS THE SANDHILLS.
HOWEVER...OUTSIDE OF THE EASTERN PANHANDLE AND WESTERN
SANDHILLS...ALL OTHER LOCATIONS WILL CONTINUE TO SEE TEMPERATURES
BELOW FREEZING. THIS WILL FACILITATE A CONTINUED MENTION
OF FREEZING DRIZZLE INTO THE EARLY AFTERNOON AS SOUNDINGS
INDICATE SATURATION BELOW THE DGZ WHERE THERE/S WEAK OMEGA. WHERE
SUFFICIENT SATURATION IS SHOWN IS ACROSS OUR NORTHEASTERN ZONES
WHERE LIGHT SNOW IS FORECAST. THE MODELS ONLY SUGGEST A FEW
HUNDRETHS AT MOST QPF...AND WITH VERY WEAK LIFT SEEN...SNOW
ACCUMULATIONS SHOULD ONLY AMOUNT TO A FEW TENTHS AT BEST.
ADDITIONAL SNOW CHANCES ARE POSSIBLE ACROSS OUR FAR NORTHERN
ZONES SATURDAY EVENING INTO EARLY SUNDAY AS A FAST MOVING MID-
LEVEL DISTURBANCE DROPS SOUTHEAST ACROSS THE DAKOTAS. THE MODELS
CONTINUE TO INDICATE THE BEST FORCING AND MOISTURE NORTH OF THE
BORDER ACROSS THE DAKOTAS...SO ONLY A FEW TENTHS ADDITIONAL SNOW
ACCUMULATIONS ARE EXPECTED.
WARMING TEMPERATURES ARE FORECAST FOR SUNDAY AS H85 T/S ARE SHOWN TO
CLIMB BACK ABOVE 0C FOR THE ENTIRE CWA. HIGHS IN THE 40S ARE
FORECAST. SUNDAY EVENING...THE MODELS DEPICT A FAST MOVING MID-
LEVEL DISTURBANCE DROPPING SOUTHEAST ACROSS THE HIGH PLAINS
OF COLORADO INTO WESTERN KANSAS. AT THIS POINT...FORCING IS TOO
WEAK WITHIN THE CWA FOR PRECIPITATION...BUT THE 00Z MODELS HAVE
TRENDED SLIGHTLY EAST WITH THE PROJECTED QPF. WILL NEED TO
MONITOR CLOSELY AS AT THIS POINT WE HAVE A DRY FORECAST GOING.
INTO EARLY NEXT WEEK A GRADUAL WARMING TREND IS FORECAST AS
RIDGING BUILDS EAST INTO THE WESTERN ROCKIES AND A TROUGH DEEPENS
INTO THE SOUTHEASTERN STATES. NORTHWEST FLOW ALOFT WILL USHER
ANOTHER DISTURBANCE ACROSS THE REGION LATE MONDAY INTO
TUESDAY...BUT THE MODELS LARGELY DISAGREE IN THE LOCATION OF THE
BEST FORCING...WILL KEEP THE INHERITED DRY FORECAST GOING FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1120 PM CST THU FEB 11 2016
MVFR/IFR/LOCAL LIFR CIGS AND FOG SHOULD SPREAD SLOWLY SOUTH AND
WEST OVERNIGHT AND THEN IMPROVE TO IFR/MVFR 18Z FRIDAY. A PATCH OF
VFR MAY DEVELOP FRIDAY AFTN ACROSS NCNTL NEB AS INDICATED BY THE
NAM AND RAP WHICH VARY WITH THE LOCATION BETWEEN KANW AND KLBF.
THE FORECAST USES THE NAM FOR THIS FEATURE WHICH KEEPS KLBF IN
MVFR ALL DAY.
CIGS SHOULD LOWER FRIDAY EVENING AS A WARM FRONT BEGINS TO MOVE
EAST THROUGH WRN NEB. THE FRONT MAY BE THE FOCUS FOR LIGHT SNOW
AND FREEZING DRIZZLE/FOG.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1120 PM CST THU FEB 11 2016
.SYNOPSIS...
ISSUED AT 309 PM CST THU FEB 11 2016
THE SURFACE DATA AT 19Z SHOWED THE WARM FRONT ACROSS THE WESTERN
NEBRASKA SANDHILLS. THE EDGE OF CLOUDINESS WAS ACROSS CENTRAL AND
NORTH CENTRAL NEBRASKA. IN THE UPPER LEVELS...WATER VAPOR IMAGERY
INDICATED A POTENTIAL VORTICITY ANOMALY ALONG THE NEBRASKA-SOUTH
DAKOTA STATE LINE MOVING SOUTHEAST.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 309 PM CST THU FEB 11 2016
CLOUDS WILL INCREASE AGAIN LATE TONIGHT IN CENTRAL AND WESTERN
NEBRASKA. WEAK LIFT IN THE SATURATED ISOTHERMAL LAYER OVER CENTRAL
AND NORTHERN NEBRASKA WILL PRODUCE LIGHT FREEZING DRIZZLE LATE
TONIGHT AFTER MIDNIGHT. OTHERWISE...TONIGHT...THE WARM FRONT WILL
BACK THROUGH WESTERN AND SOUTHERN NEBRASKA BRINGING MODERATE NORTH
TO NORTHWEST WIND AND COLDER TEMPERATURES FRIDAY. WITH THE FRONT
STALLING ON THE PLAINS OF WYOMING AND COLORADO...CLOUDS WILL
PROBABLY HANG IN MOST OF THE DAY FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 309 PM CST THU FEB 11 2016
MID TERM...FRIDAY NIGHT THROUGH SUNDAY...IN THE MID RANGE
PERIOD...PRECIPITATION CHANCES AND FREEZING DRIZZLE POTENTIAL WILL
BE THE MAIN FORECAST CHALLENGE FOR LATE FRIDAY NIGHT INTO SATURDAY.
THIS WILL BE FOLLOWED BY THE THREAT FOR LIGHT SNOW ACROSS THE
SANDHILLS AND NORTHERN NEBRASKA SATURDAY NIGHT INTO SUNDAY. FOR
FRIDAY NIGHT...THE BOUNDARY LAYER ARCTIC FRONT WILL REMAIN ANCHORED
ACROSS THE PANHANDLE FRIDAY NIGHT INTO THE MORNING HOURS ON
SATURDAY. AT THE SAME TIME...A H750 WARM FRONT WILL BEGIN TO TRACK
EAST OF THE PANHANDLE...BECOMING ORIENTED ALONG A MERRIMAN TO NORTH
PLATTE LINE BY 12Z SATURDAY. LIFT WILL INCREASE INVOF...AND EAST OF
THE ELEVATED FRONT OVERNIGHT...LEADING TO INCREASED CHANCES FOR
LIGHT PRECIPITATION. EAST OF THE ELEVATED WARM FRONT...SNOW WILL BE
THE MAIN PTYPE...WHILE ALONG AND WEST OF THE FRONT...FREEZING
DRIZZLE WILL BE THE MAIN THREAT. WILL LEAVE THE FREEZING PTYPE
MENTION AS FZDZ FOR NOW AS THERE IS A DECENT DRY LAYER ABOVE THE
MOIST LAYER WHICH EXTENDS APPROXIMATELY FROM THE SFC TO 800MB. ON
SATURDAY...THIS ELEVATED WARM FRONT WILL CONTINUE TO TRACK EAST AND
WILL PUSH INTO CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA BY
00Z SUNDAY. HOWEVER...WITH THE EXCEPTION OF THE PANHANDLE AND FAR
WESTERN CWA...H850 TEMPS WILL REMAIN BELOW FREEZING. THIS WILL
FACILITATE AT LEAST A FZDZ MENTION INTO THE AFTERNOON HOURS. THIS
FREEZING DRIZZLE THREAT WILL BEGIN TO WANE DURING THE AFTERNOON
HOURS AS THE H750 FRONT STALLS ACROSS THE EASTERN CWA...AND ELEVATED
LIFT WEAKENS CONSIDERABLY. BY SATURDAY EVENING...A FAST MOVING MID
LEVEL DISTURBANCE WILL TRACK INTO THE WESTERN DAKOTAS...CLEARING THE
EASTERN DAKOTAS BY 12Z SUNDAY. LIGHT SNOW CONTINUES TO BE A THREAT
IN ASSOCIATION WITH THIS FEATURE...HOWEVER IT APPEARS AT THIS
TIME...IT WILL BE CONFINED TO THE NORTHERN THIRD OF THE FORECAST
AREA. QPF/S WILL BE VERY LIGHT AS THE BEST FORCING WILL RESIDE NORTH
OF THE FORECAST AREA OVER SOUTH DAKOTA.
LONG RANGE...SUNDAY NIGHT THROUGH THURSDAY...ON SUNDAY NIGHT...THE
GFS AND ECMWF HAVE A MID LEVEL DISTURBANCE TRACKING ACROSS COLORADO
INTO KANSAS. LOW POPS WERE PLACED IN THE FORECAST IN THE FAR SWRN
CORNER OF THE FORECAST AREA WHICH IS ON THE NORTHERN PERIPHERY OF
THE BEST LIFT...WHICH RESIDES OVER NWRN KS AND EAST CENTRAL
COLORADO. AFTER SUNDAY NIGHT...THE OVERALL PATTERN BEGINS TO FLATTEN
WITH A LOW AMPLITUDE RIDGE IN THE WEST AND LOW AMPLITUDE TROUGH IN
THE EAST. WEST NORTHWEST FLOW WILL RESIDE ACROSS THE FORECAST AREA
EARLY IN THE WEEK WITH A RIDGE BUILDING INTO THE CENTRAL CONUS BY
MIDWEEK NEXT WEEK. DRY CONDITIONS AND WARM TEMPERATURES ARE EXPECTED
WITH HIGHS GENERALLY IN THE 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1120 PM CST THU FEB 11 2016
MVFR/IFR/LOCAL LIFR CIGS AND FOG SHOULD SPREAD SLOWLY SOUTH AND
WEST OVERNIGHT AND THEN IMPROVE TO IFR/MVFR 18Z FRIDAY. A PATCH OF
VFR MAY DEVELOP FRIDAY AFTN ACROSS NCNTL NEB AS INDICATED BY THE
NAM AND RAP WHICH VARY WITH THE LOCATION BETWEEN KANW AND KLBF.
THE FORECAST USES THE NAM FOR THIS FEATURE WHICH KEEPS KLBF IN
MVFR ALL DAY.
CIGS SHOULD LOWER FRIDAY EVENING AS A WARM FRONT BEGINS TO MOVE
EAST THROUGH WRN NEB. THE FRONT MAY BE THE FOCUS FOR LIGHT SNOW
AND FREEZING DRIZZLE/FOG.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...BUTTLER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS PORTLAND OR
301 AM PST FRI FEB 12 2016
.SYNOPSIS...A DECENT PACIFIC COLD FRONT WILL MOVE ONTO THE COAST MID
MORNING TODAY AND MOVE ACROSS THE REMAINDER OF SOUTHWEST WASHINGTON
AND NORTHWEST OREGON TODAY FOR A DECENT SHOT OF RAIN. SNOW LEVELS
WILL FALL BELOW THE CASCADE PASSES TONIGHT AS AN AREA OF SHOWERS
ASSOCIATED WITH THE ASSOCIATED UPPER TROUGH MOVES THROUGH WESTERN
WASHINGTON AND CLIPS THE NORTH PART OF OUR FORECAST AREA. A WARM
FRONT WILL BRING INCREASING RAIN TO THE NORTH PART OF THE AREA
SATURDAY AFTERNOON AND ALL OF SOUTHWEST WASHINGTON AND NORTHWEST
OREGON SATURDAY NIGHT AND SUNDAY. THE RAIN WILL BE HEAVY AT TIMES
SATURDAY NIGHT AS THE FIRST STRONGER WAVE ALONG THE WARM FRONT MOVES
THROUGH...FOLLOWED BY A SECOND WEAKER WAVE ON SUNDAY. THE WARM FRONT
WILL LIFT NORTH INTO WESTERN WASHINGTON SUNDAY NIGHT AND MONDAY WITH
RAIN DECREASING FROM THE SOUTH. ADDITIONAL UNSETTLED WEATHER WILL
PRODUCE MORE VALLEY RAIN AND MOUNTAIN SNOW THE MIDDLE AND LATTER
PARTS OF NEXT WEEK.
&&
.SHORT TERM...THE WARM FRONT WITH THE SYSTEM OFF THE COAST BROUGHT
SOME RAIN TO SOUTHWEST WASHINGTON AND NORTHWEST OREGON FRIDAY
AFTERNOON AND EVENING. THE COLDER CLOUD TOPS ASSOCIATED WITH THE
COLD FRONT SEPARATED FROM THE LOW LEVEL FRONT AND BROUGHT A PERIOD
OF DECENT RAIN TO THE COAST OVERNIGHT. THE MAIN LOW LEVEL COLD FRONT
IS STILL OFFSHORE EARLY THIS MORNING AND WILL MOVE ONSHORE MID
MORNING TODAY WITH ONE MORE SHOT OF RAIN AS IT MOVES THROUGH THE
INLAND AREAS TODAY. THE FRONT WILL BE EAST OF THE CASCADES BY MID
AFTERNOON.
THE ASSOCIATED COOL UPPER TROUGH IS OFFSHORE THIS MORNING...AND WILL
MOVE THROUGH WESTERN WASHINGTON AND FAR NORTHERN OREGON TONIGHT FOR
SOME SHOWERS. SNOW LEVELS WILL FALL BELOW THE CASCADE PASSES
TONIGHT...BUT SNOW AMOUNTS WILL LIKELY STAY BELOW ADVISORY CRITERIA.
THERE IS A SLIGHT CHANCE OF THUNDER OVER THE NORTHERN COASTAL WATERS
LATE TODAY AND TONIGHT...AND NEAR THE NORTH COASTAL ZONES TONIGHT.
ATTENTION WILL THEN TURN TO THE SYSTEM NOW APPROACHING 150W. THE
WARM FRONT FROM THIS SYSTEM WILL SPREAD INTO SOUTHWEST WASHINGTON
AND NORTHWEST OREGON SATURDAY AFTERNOON AND BE OVER THE ENTIRE AREA
SATURDAY NIGHT AND SUNDAY. THE FIRST WAVE RIDING ALONG THE WARM
FRONT WILL MOVE THROUGH SATURDAY NIGHT. THIS WAVE LOOKS FAIRLY
STRONG...MAY PRODUCE GALE FORCE WINDS OVER THE COASTAL WATERS...AND
LOCALLY HEAVY RAIN OVER SOUTHWEST WASHINGTON AND NORTHWEST OREGON. A
SECOND WEAKER WAVE WILL KEEP THE RAIN GOING ON SUNDAY. SNOW LEVELS
WILL INITIALLY BE AROUND THE PASSES LATE SATURDAY AND A GOOD PART OF
SATURDAY NIGHT BEFORE RISING WELL ABOVE THE PASSES SUNDAY. GIVEN THE
MODEL QPF...THERE APPEARS A GOOD CHANCE THAT PORTIONS OF THE SOUTH
WASHINGTON CASCADES AND PERHAPS THE NORTH OREGON CASCADES ABOVE 4000-
5000 FT WILL SEE ENOUGH SNOW...SOMEWHERE ON THE ORDER OF 4 TO 8
INCHES...TO REQUIRE A SNOW ADVISORY SATURDAY NIGHT BEFORE THE SNOW
LEVEL RISES.
THE RAIN SHOULD DECREASE FROM THE SOUTH EITHER LATE SUNDAY OR SUNDAY
NIGHT AS THE WAR FRONT LIFTS NORTH. TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
SUNDAY NIGHT THROUGH THURSDAY...THE PROGRESSIVE WEATHER PATTERN WILL
PERSIST INTO NEXT WEEK. MODELS CONTINUE TO SHOW A FLAT UPPER LEVEL
RIDGE MOVING OVER THE PAC NW EARLY NEXT WEEK. THIS COULD BRING A
BRIEF BREAK FROM THE RAIN MONDAY...BUT WILL MAINTAIN SOME CHANCE POPS
IN THE FORECAST DUE TO LINGERING INSTABILITY. A WEAK SHORTWAVE
DISTURBANCE LOOKS TO RIDE OVER THE TOP OF THE RIDGE ON TUESDAY AND
WILL LIKELY PUSH ANOTHER FRONT ACROSS THE REGION LATE TUESDAY/EARLY
WEDNESDAY BRINGING MORE RAIN. CASCADE SNOW LOOKS TO RETURN WEDNESDAY
AFTERNOON WITH SNOW LEVELS LOWERING TO AROUND 3500 FT. UNSETTLED
WEATHER AND LOWERING SNOW LEVELS CONTINUE INTO THURSDAY AS THE BASE
OF THE TROUGH MOVES ACROSS THE FORECAST AREA. MONDAY WILL LIKELY BE
THE WARMEST DAY...WITH TEMPS TRENDING COOLER EARLY NEXT WEEK. /64
&&
.AVIATION...A VERY MIXED BAG IN TERMS OF CONDITIONS AT THIS HOUR. FOG
AND LOW CLOUDS HAVE HUNG AROUND THE WILLAMETTE VALLEY AND NORTH TO
INCLUDE THE TUALATIN VALLEY AS WELL. AS SUCH HAVE SEEN VLIFR CONDS AT
KEUG...KSLE...AND KHIO AT TIMES BUT WITH PERIODIC IMPROVEMENTS TO
JUST STRAIGHT IFR CIGS/VSBYS. HAVE SEEN CIGS AT KPDX EVEN BE RATHER
INCONSISTENT AS A MVFR DECK HAS WAVERED BETWEEN 1500 FEET AGL AND NON
EXISTENT. GIVEN THE STRATUS/FOG DECK IS RATHER NEBULOUS AND MODEL/MOS
GUIDANCE IS FAR LESS THAN HELPFUL..HAVE VERY LOW CONFIDENCE FOR MOST
OF THE INLAND TAFS COVERING THE NEXT SEVERAL HOURS. COASTAL TERMINALS
SAW A DECENT BREAK IN THE LOW CLOUDS AND FOG...HOWEVER...THERE IS
JUST ENOUGH ONSHORE FLOW TO PUSH THE MARINE DECK ONSHORE. WILL LIKELY
SEE THE COASTAL TERMINALS REMAIN IFR WITH CIGS 007-010 THROUGH AT
LEAST 21Z. IN GENERAL...GUIDANCE INDICATES CONDS IMPROVING TO VFR
SOMETIME AT OR AFTER 13/00Z.
KPDX AND APPROACHES...LOW CONFIDENCE IN THE FORECAST AS CIGS REMAIN
HIGHLY VARIABLE. THE MVFR 016 AGL CIGS CURRENTLY IN PLACE SHOW LITTLE
SIGN OF MOVING ALTHOUGH GORGE OUTFLOW WINDS ARE PROBABLY KEEPING THEM
FORM DROPPING LOWER. WEB CAMS OF DOWNTOWN PORTLAND SHOW SOME LOWER
CLOUDS BANKING UP AGAINST THE WEST HILLS. SHOULD THE WINDS EASE
BEFORE 18Z OR SO...MAY SEE SOME IFR CIGS QUICKLY DRIFT OVER THE FIELD
THIS MORNING. OTHERWISE...EXPECT THE CIGS TO LIFT BECMG VFR AFT 21Z.
/JBONK
&&
.MARINE...WINDS HAVE BEEN VERY SLOW TO INCREASE TONIGHT AND HAVE JUST
RECENTLY SEEN GUSTS CLIMB REACHING 20-25 KT. DECIDED TO EXTEND THE
SCA FOR WINDS THROUGH 8 AM THIS MORNING BASED ON LOOSELY BETTER
PERFORMANCE OUT OF THE HRRR MODEL THUS FAR AND IT`S TIMING OF
DROPPING WINDS BELOW CRITERIA THEN. STILL...THIS REMAINS A VERY
MARGINAL WIND EVENT. LONG PERIOD SWELL CONTINUES TO BUILD THIS
MORNING AND SHOULD BE PEAKING IN THE 13-15 FT RANGE SHORTLY.
NEXT EVENT OF NOTE WILL BE A THREAT FOR LOW END GALE GUSTS SATURDAY
NIGHT. MODELS HAVE CONTINUED TO BACK OFF ON THE WIND SPEEDS OVER THE
LAST 48 HOURS. STILL HAVE LOW END GALE GUSTS IN THE FORECAST FOR THE
TIME BEING. OPTED TO HOLD OFF ISSUING A WATCH AS THE DECREASING TREND
WOULD GIVE ANOTHER 12 HOURS WORTH OF MODEL RUNS TO SEE THOSE GUSTS
FALL BACK TOWARD THE LOWER 30 KT RANGE AND THUS OUT OF GALE CRITERIA.
SURFACE PRESSURE FEATURES THEREAFTER REMAIN HIGHLY VARIABLE IN
LOCATION AND TIMING. THE TREND...THOUGH... IS FOR SEAS TO FALL BELOW
10 FT SUNDAY EVENING WITH WINDS BECOMING LESS AND LESS EVENTFUL.
/JBONK
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 AM PST THIS MORNING
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST
SUNDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
4 AM PST SATURDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEDFORD OR
931 PM PST THU FEB 11 2016
.DISCUSSION...AN UPDATE HAS BEEN MADE TO THE FORECASTS OF THE
PROBABILITY OF PRECIPITATION AND PRECIPITATION QUANTITY TONIGHT
THROUGH FRIDAY. A WEAK COLD FRONT IS OFFSHORE AND WILL TRACK
EAST AND DISSIPATE THROUGH FRIDAY. THERE IS A HIGH PROBABILITY OF
LIGHT RAIN NEAR THE COAST AND OVER THE COASTAL RANGE...TAPERING TO
CHANCE TO LIKELY POPS IN THE REMAINDER OF SOUTHWEST OREGON AND A
SLIGHT CHANCE FOR MUCH OF KLAMATH COUNTY AND CENTRAL SISKIYOU
COUNTY. WITH A SHALLOW MOIST LAYER, THIS WILL BE A LIGHT DRIZZLY
RAIN WHERE IT DOES RAIN INLAND. DESPITE THE CLOUD
COVER...TEMPERATURES WILL REMAIN WELL ABOVE NORMAL ON FRIDAY.
TEMPERATURES WILL BE A BIT COOLER...AROUND NORMAL ON SATURDAY.
THE NEXT SYSTEM WILL HAVE ITS FOCUS NORTH OF OUR AREA BUT THE GFS
CONTINUES TO INDICATE IT WILL BRING LIGHT RAIN NORTH OF THE UMPQUA
DIVIDE SATURDAY NIGHT THROUGH SUNDAY WITH THE PROBABILITY
DIMINISHING AS ONE TRAVELS FARTHER TO THE SOUTH AND EAST.
HIGH PRESSURE LOOKS TO BUILD SUNDAY NIGHT INTO TUESDAY NIGHT. THE
TIMING...STRENGTH AND POSITION OF THE NEXT TROUGH ARE STILL IN
QUESTION BUT THERE HAS BEEN CONSISTENCY IN INDICATING A CHANGE IN
THE PATTERN AND THE ARRIVAL OF A STRONGER SYSTEM AT MID-WEEK. THE
00Z GFS HAS TRENDED FARTHER SOUTH WITH A FOCUS OF PRECIPITATION
FROM AROUND MT SHASTA SOUTHWARD TO CENTRAL CALIFORNIA.
&&
.AVIATION...FOR THE 12/00Z TAF CYCLE... VFR CONDITIONS WILL PREVAIL
INTO TONIGHT. AREAS OF MVFR CIGS/VSBYS IN LIGHT RAIN WILL DEVELOP
ALONG THE COAST LATE TONIGHT AND SPREAD INLAND TO THE CASCADES DURING
THE DAY FRIDAY WITH AREAS OF HIGHER TERRAIN BECOMING OBSCURED.
-JRS
&&
.MARINE...UPDATED 900 PM PST THU FEB 11 2016...MIXED HIGH WEST
SWELL AT 19 TO 20 SECONDS AND MODERATE SOUTHWEST SWELL AT 10 TO 11
SECONDS WILL STEEPEN AND INCREASE INTO FRIDAY MORNING WITH THE
PERIOD BECOMING 17 TO 18 SECONDS. SEAS WILL THEN REMAIN WESTERLY
WITH A GRADUALLY DIMINISHING PERIOD THROUGH SUNDAY. COMBINED SEAS
WILL BUILD TO 13 TO 14 FEET THROUGH FRIDAY MORNING...SUBSIDE TO 12
FEET FRIDAY AFTERNOON THROUGH SATURDAY...REBUILD TO 12 TO 13 FEET
SATURDAY NIGHT...THEN SUBSIDE BELOW 10 FEET SUNDAY AFTERNOON. A
WEAK COLD FRONT WILL MOVE ONSHORE FRIDAY MORNING...AND THIS WILL
BRING SMALL CRAFT WINDS TO THE NORTHERN OUTER WATERS TONIGHT.
OFFSHORE HIGH PRESSURE WILL BUILD FRIDAY...THEN WEAKEN SATURDAY. A
SLIGHTLY STRONGER COLD FRONT WILL MOVE ONSHORE SATURDAY NIGHT.
OFFSHORE HIGH PRESSURE WILL REBUILD SUNDAY...THEN WEAKEN TUESDAY
AS A STRONGER FRONT APPROACHES THE AREA. -JRS
&&
.PREV DISCUSSION... /ISSUED 241 PM PST THU FEB 11 2016/
DISCUSSION...SKIES ARE THINNING OUT IN THE WAKE OF THE WEAK
SHORTWAVE THAT MOVED THROUGH THE AREA THIS MORNING. THIS IS IN
RESPONSE TO AN UPPER RIDGE BUILDING AHEAD OF A DEEPENING TROUGH NEAR
35N/140W. THIS SHOULD SLOW DOWN THE EASTWARD PROGRESSION OF THE
FRONT LATE TONIGHT. CURRENT HRRR MODEL SUGGEST THIS AND IS IN LINE
WITH THE NAM AND GFS. THEREFORE HAVE ADJUSTED POPS DOWN FOR THIS
EVENING AND TONIGHT, KEEPING THE BEST CHANCE FOR ANY RAIN OVER THE
MARINE WATERS AND ALONG THE COAST, NORTH OF CAPE BLANCO. I DON`T
THINK RAINFALL WILL MAKE MUCH IF ANY PROGRESS INLAND TONIGHT, BUT
STILL KEPT IN A SLIGHT CHANCE TO CHANCE ALONG THE SOUTH COAST AND IN
PORTIONS OF COOS AND NORTHWEST DOUGLAS COUNTY. SKIES SHOULD REMAIN
MOSTLY CLEAR THROUGH THIS EVENING BEFORE INCREASING AHEAD OF THE
COLD FRONT TONIGHT.
THE COLD FRONT WILL REACH THE COAST FRIDAY MORNING, THEN MOVING
ONSHORE DURING THE DAY FRIDAY. THIS WILL BRING THE BEST CHANCE FOR
MEASURABLE RAIN WITH MOST OF THE RAIN CENTERED ALONG THE COASTAL
MOUNTAINS AND CASCADES. EVEN THEN, QPF AMOUNTS ARE NOT EXPECTED TO
BE SIGNIFICANT AND MODELS HAVE BEEN TRENDING LOWER WITH QPF AMOUNTS.
SNOW LEVELS WILL LOWER ON FRIDAY, BUT WILL REMAIN ABOVE ALL THE
PASSES THROUGH FRIDAY.
A MOIST WESTERLY FLOW WILL SET UP FRIDAY NIGHT WITH A WEAK SHORT
WAVE MOVING THROUGH. MOST SHOWERS ARE EXPECTED TO REMAIN ALONG AND
WEST OF THE CASCADES, BUT THEY ARE EXPECTED TO BE LIGHT WITH SNOW
LEVELS BETWEEN 4500 AND 5000 FEET. THEREFORE WERE NOT EXPECTING
MUCH, IF ANY IMPACT ON ANY OF THE ROADS IN THE CASCADES.
500 MB HEIGHTS INCREASE SOME AS WEAK RIDGING BUILDS INTO THE AREA
SATURDAY. CONDITIONS SHOULD BE DRY DURING THE DAY, THEN A WARM FRONT
WILL ARRIVE SATURDAY NIGHT BRINGING STEADY LIGHT TO MODERATE
PRECIPITATION. THE BEST CHANCE FOR HEAVIER PRECIPITATION WILL BE IN
THE NORTHERN PART OF THE AREA SATURDAY EVENING, THEN THE FOCUS WILL
SHIFT SOUTH SATURDAY NIGHT THROUGH SUNDAY. SNOW LEVELS SATURDAY NIGHT
WILL INCREASE AND LIKELY BE ABOVE ALL THE PASSES THROUGH SUNDAY.
THE UPPER RIDGE WILL BUILD BACK INTO THE AREA SUNDAY NIGHT WITH
RAIN DECREASING, THEN ENDING FROM SOUTH TO NORTH. -PETRUCELLI
LONG TERM DISCUSSION...MONDAY THROUGH THURSDAY. MODELS AND THE
ENSEMBLE PLOTS START IN REMARKABLY GOOD AGREEMENT MONDAY WITH AN
UPPER LEVEL RIDGE OVER THE WEST COAST SHUNTING SYSTEMS JUST TO THE
NORTH OF THE FORECAST AREA. IT IS NOT UNTIL WEDNESDAY MORNING THAT
THE MODEL PLOTS SHOW ANY SIGNIFICANT DIVERGENCE...BUT THE MAIN
DIFFERENCES ARE WITH TIMING OF THE SHIFTING OF THE UPPER LEVEL RIDGE
TO THE EAST. THE GFS IS SLIGHTLY FASTER ON WEDNESDAY BRINGING
PRECIPITATION ONTO THE COAST WEDNESDAY MORNING, WITH THE ECMWF
BRINGING IT IN IN THE AFTERNOON. FROM THERE THE OVERALL PATTERN OF
AN UPPER LEVEL TROUGH OVER THE WEST COAST REMAINS FOR ALL OF THE
PLOTS...BUT THAT IS THE ONLY AGREEMENT WITH PLOTS ALL OVER THE
PLACE WITH DEPTH AND PLACEMENT OF THESE UPPER TROUGHS. WITH THIS IN
MIND HAVE GONE WITH THE ENSEMBLE MEAN POPS FOR THE REMAINDER OF THE
EXTENDED FORECAST. -SVEN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL
4 PM PST SUNDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY UNTIL 4 AM PST FRIDAY FOR PZZ370.
$$
DW/MAP/JRS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1101 PM EST SAT FEB 13 2016
.SYNOPSIS...
A STRONG BUT QUICKLY-MOVING SURFACE HIGH WILL MOVE ACROSS THE
REGION TONIGHT AND SUNDAY. A STORM SYSTEM WILL BEGIN FORM TO THE
SOUTH OF THE STATE ON MONDAY. A WINTRY MIX AND PERHAPS PLAIN RAIN
WILL OCCUR AFTER AN INITIAL PERIOD OF SNOW. THE LOW PRESSURE
CENTER SHOULD PASS OVER EASTERN PA ON TUESDAY. LATER IN THE
WEEK...A RIDGE OF HIGH PRESSURE MOVES IN ALOFT WITH MUCH WARMER
AIR FOR LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
10 PM UPDATE...
A FEW DISTINCT SNOW BANDS ARE LEFT OVER THE AREA WITH A VERY
PERSISTENT PAIR. BUT THEY ALL LOOK LIKE THEY WILL MIGRATE SLOWLY
TO THE SOUTH THROUGH THE NEXT FEW HOURS AS THE FLOW VEERS. ANY
ACCUMULATIONS WILL BE LIGHT...AND THE NARROW-NESS OF THE BANDS
WILL MAKE IT HIGHLY LOCALIZED. TEMPS ALREADY BELOW ZERO IN THE
NORTH AND TEMPS ON TRACK TO HIT FCST LOWS. WINDS DO NOT GO
SLACK...SO THE MIXING WILL KEEP THE TEMPS FROM GOING TOO LOW. THE
WIND CHILL ADVY/WARN LOOK WELL PLACED AND TIMED. THE WIND SHOULD
BECOME EVEN LIGHTER THROUGH THE DAY FROM W-E AND ALLOW THE WC
FLAGS TO DIE ON SCHEDULE.
8 PM UPDATE...
SNOW BANDS CONTINUE RUNNING NW-SE THRU THE AREA. INTERESTING TO
NOTE THAT THE HRRR AND RAP BOTH MAKE THE LONG BAND THRU THE
CENTRAL MTNS REACH DOWN INTO LEBANON AND LANCASTER COUNTIES ON THE
BERKS BORDER. THIS IS VERY NEARLY THE LOCATION OF THE BIG ACCIDENT
EARLIER TODAY. THE SHSN DO APPEAR TO DISSIPATE BY MIDNIGHT...THO.
WILL KEEP POPS IN FOR MOST PLACE FOR THE TIME BEING BUT CALL
ADDTNL ACCUMS LESS THAN AN INCH EVERYWHERE.
PREV...
OVERNIGHT THE MASSIVE SURFACE HIGH MOVES IN SHOULD BE OVERHEAD BY
SUNDAY MORNING. THIS WILL LOWER THE INVERSION HEIGHT...SHUTTING
OFF THE SNOW SHOWERS THIS EVENING AND EARLY TONIGHT AND SHUTTING
DOWN THE WINDS. THE LIGHT WINDS BEFORE SUNRISE COULD SQUEEZE OUT A
FEW MORE DEGREES OF RADIATIONAL COOLING. GOING TO BE A VERY COLD
MORNING. MANY LOCATIONS WILL LIKELY HAVE THEIR COLDEST OVERNIGHT
LOW OF THE SEASON.
&&
.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE IN CONTROL. WINDS SLACKEN AND TEMPS ONLY AS MILD AS
SAT...BUT SHOULD FEEL BETTER.
THE HIGH MOVES RAPIDLY TO THE EAST LATE SUNDAY NIGHT. EARLY
RADIATIONAL COOLING SHOULD DROP TEMPERATURES OFF FAST SUNDAY
EVENING. BUT RETURN FLOW COULD CAUSE TEMPERATURES TO BEGIN TO
SLOWLY RISE SUNDAY NIGHT INTO MONDAY MORNING.
GOING TO BE INTERESTING MONDAY-TUESDAY WEATHER!
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
*IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT
WEEK.
DID NOT CHANGE MUCH FOR MONDAY...TUE FRAME.
MAIN THING WAS TO INSERT SOME ZR INTO THE GRIDS AFTER 00Z
TUE...THROUGH LATE TUESDAY MORNING. BASED ON WPC GRAPHICS.
ALSO DID UP POPS SOME.
DID NOT DO A LOT WITH SNOW AMTS SO FAR. MAY ADJUST MORE LATER.
EC MAY BE TO FAR WEST...BUT EITHER WAY...EXPECT SOME SNOW TO
PILE UP ACROSS SOUTH CENTRAL PA BY LATE MONDAY AFT...ABOUT
1 TO 2 INCHES...AS SYSTEM LIFTS NE FAST...AND WARM ADVECTION
WAITS FOR NO MAN.
MORE DETAIL BELOW.
CLOUDS AND POTENTIAL LIGHT SNOW COULD ARRIVE IN SOUTHWESTERN
AREAS MONDAY MORNING AS INDICATED IN SOME ENSEMBLE FORECASTS.
BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT
SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER
SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE
BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND
ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD
CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS
EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS
EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL
UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST
FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE
LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS.
WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS
EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL
ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A
POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS
HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY.
EXPECT BULK OF PCPN TO BE OUT OF THE AREA BY LATE TUE AM.
ANOTHER COLD FRONT WED. DID UP POPS SOME ACROSS THE WEST.
MOISTURE IS LIMITED.
NOT A BAD DAY FOR THU OR FRI...AS HIGH PRESSURE BUILDS INTO
THE AREA.
PERHAPS A FEW RAIN AND SNOW SHOWERS FOR LATE IN THE WEEK WITH
THE NEXT COLD FRONT.
NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS
HEIGHTS ARE FORECAST TO RISE AND A LOW PRESSURE SYSTEM LIFTS
THROUGH THE GREAT LAKES TO THE WEST OF PA.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
ARCTIC AIR HAS BROUGHT COLD TEMPERATURES AND STRONG GUSTY WINDS TO
THE REGION. SNOW SQUALLS ARE COMMON IN THE WESTERN MOUNTAINS WITH
IMPACTS ON KJST AND KBFD. A BAND OF SHOWERS OVER CENTRAL PA HAS
BROUGHT ONLY MVFR CIGS AND VSBYS TO UNV...SO WILL LEAVE A BRIEF
TEMPO THROUGH 08Z...AS MODELS HAVE MOST SHOWERS OUTSIDE OF THE NW
MTNS FADING BY 09Z. AS THE THERMAL PROFILE IS ADIABATICALLY
NEUTRAL EXPECT ANY GUSTY WINDS ALOFT TO FILTER TO THE SURFACE. SO
SNOW AND BLOWING SNOW IS POSSIBLE WITH THE STRONG GUSTY WINDS.
GOOD GUST SPREADS TOO WHICH AFFECT TAKEOFF/LANDINGS. GUSTS OVER
30KTS HAVE BEEN OBSERVED.
BFD AND JST WILL SEE IFR CIGS AND VSBYS CONTINUING UNTIL AROUND
09Z AS THE TROUGH LIFTS TO THE NORTHEAST THE WINDS WILL SHIFT TO
THE NORTH AND DIMINISH. THIS WILL END THE GUSTS AND CEASE MOST
BLOWING SNOW...ALSO CUTTING OFF MOST LAKE EFFECT AND TOPOGRAPHIC
ENHANCEMENTS. THERE SHOULD THEN BE IMPROVED CONDITIONS.
THINGS SHOULD BE MUCH NICER SUNDAY...THOUGH A TAD COLD WITH
TEMPERATURES WELL BELOW NORMAL.
HIGH PRESSURE SUNDAY DRIFTS EAST OVERNIGHT SO THE PERIOD OF NICE
WEATHER WITH VFR WILL BE SHORT LIVED AS CLOUDS AND POTENTIAL
PRECIPITATION MOVE IN FOR MONDAY AND INTO TUESDAY. SNOW AND
ASSORTED WINTRY PRECIPITATION WILL LIKELY AFFECT FLYING MONDAY
INTO TUESDAY.
OUTLOOK...
SUN...NO SIG WX EXPECTED MAINLY VFR.
MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING.
MON NIGHT AND TUE...SNOW LIKELY WRN HALF OF PENN...WITH RAIN
AND/OR SNOW IN THE SE. WIDESPREAD RESTRICTIONS SET IN. LLWS POSS
SE.
WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN
PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST.
THU...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037-
041-042.
WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-
017>019-024>028-033>036-045-046-049>053-056>059-063>066.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM/DANGELO
SHORT TERM...GRUMM
LONG TERM...FITZGERALD/GARTNER/MARTIN
AVIATION...CERU/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1012 PM EST SAT FEB 13 2016
.SYNOPSIS...
A STRONG BUT QUICKLY-MOVING SURFACE HIGH WILL MOVE ACROSS THE
REGION TONIGHT AND SUNDAY. A STORM SYSTEM WILL BEGIN FORM TO THE
SOUTH OF THE STATE ON MONDAY. A WINTRY MIX AND PERHAPS PLAIN RAIN
WILL OCCUR AFTER AN INITIAL PERIOD OF SNOW. THE LOW PRESSURE
CENTER SHOULD PASS OVER EASTERN PA ON TUESDAY. LATER IN THE
WEEK...A RIDGE OF HIGH PRESSURE MOVES IN ALOFT WITH MUCH WARMER
AIR FOR LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
10 PM UPDATE...
A FEW DISTINCT SNOW BANDS ARE LEFT OVER THE AREA WITH A VERY
PERSISTENT PAIR. BUT THEY ALL LOOK LIKE THEY WILL MIGRATE SLOWLY
TO THE SOUTH THROUGH THE NEXT FEW HOURS AS THE FLOW VEERS. ANY
ACCUMULATIONS WILL BE LIGHT...AND THE NARROW-NESS OF THE BANDS
WILL MAKE IT HIGHLY LOCALIZED. TEMPS ALREADY BELOW ZERO IN THE
NORTH AND TEMPS ON TRACK TO HIT FCST LOWS. WINDS DO NOT GO
SLACK...SO THE MIXING WILL KEEP THE TEMPS FROM GOING TOO LOW. THE
WIND CHILL ADVY/WARN LOOK WELL PLACED AND TIMED. THE WIND SHOULD
BECOME EVEN LIGHTER THROUGH THE DAY FROM W-E AND ALLOW THE WC
FLAGS TO DIE ON SCHEDULE.
8 PM UPDATE...
SNOW BANDS CONTINUE RUNNING NW-SE THRU THE AREA. INTERESTING TO
NOTE THAT THE HRRR AND RAP BOTH MAKE THE LONG BAND THRU THE
CENTRAL MTNS REACH DOWN INTO LEBANON AND LANCASTER COUNTIES ON THE
BERKS BORDER. THIS IS VERY NEARLY THE LOCATION OF THE BIG ACCIDENT
EARLIER TODAY. THE SHSN DO APPEAR TO DISSIPATE BY MIDNIGHT...THO.
WILL KEEP POPS IN FOR MOST PLACE FOR THE TIME BEING BUT CALL
ADDTNL ACCUMS LESS THAN AN INCH EVERYWHERE.
PREV...
OVERNIGHT THE MASSIVE SURFACE HIGH MOVES IN SHOULD BE OVERHEAD BY
SUNDAY MORNING. THIS WILL LOWER THE INVERSION HEIGHT...SHUTTING
OFF THE SNOW SHOWERS THIS EVENING AND EARLY TONIGHT AND SHUTTING
DOWN THE WINDS. THE LIGHT WINDS BEFORE SUNRISE COULD SQUEEZE OUT A
FEW MORE DEGREES OF RADIATIONAL COOLING. GOING TO BE A VERY COLD
MORNING. MANY LOCATIONS WILL LIKELY HAVE THEIR COLDEST OVERNIGHT
LOW OF THE SEASON.
&&
.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE IN CONTROL. WINDS SLACKEN AND TEMPS ONLY AS MILD AS
SAT...BUT SHOULD FEEL BETTER.
THE HIGH MOVES RAPIDLY TO THE EAST LATE SUNDAY NIGHT. EARLY
RADIATIONAL COOLING SHOULD DROP TEMPERATURES OFF FAST SUNDAY
EVENING. BUT RETURN FLOW COULD CAUSE TEMPERATURES TO BEGIN TO
SLOWLY RISE SUNDAY NIGHT INTO MONDAY MORNING.
GOING TO BE INTERESTING MONDAY-TUESDAY WEATHER!
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
*IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT
WEEK.
DID NOT CHANGE MUCH FOR MONDAY...TUE FRAME.
MAIN THING WAS TO INSERT SOME ZR INTO THE GRIDS AFTER 00Z
TUE...THROUGH LATE TUESDAY MORNING. BASED ON WPC GRAPHICS.
ALSO DID UP POPS SOME.
DID NOT DO A LOT WITH SNOW AMTS SO FAR. MAY ADJUST MORE LATER.
EC MAY BE TO FAR WEST...BUT EITHER WAY...EXPECT SOME SNOW TO
PILE UP ACROSS SOUTH CENTRAL PA BY LATE MONDAY AFT...ABOUT
1 TO 2 INCHES...AS SYSTEM LIFTS NE FAST...AND WARM ADVECTION
WAITS FOR NO MAN.
MORE DETAIL BELOW.
CLOUDS AND POTENTIAL LIGHT SNOW COULD ARRIVE IN SOUTHWESTERN
AREAS MONDAY MORNING AS INDICATED IN SOME ENSEMBLE FORECASTS.
BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT
SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER
SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE
BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND
ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD
CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS
EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS
EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL
UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST
FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE
LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS.
WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS
EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL
ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A
POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS
HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY.
EXPECT BULK OF PCPN TO BE OUT OF THE AREA BY LATE TUE AM.
ANOTHER COLD FRONT WED. DID UP POPS SOME ACROSS THE WEST.
MOISTURE IS LIMITED.
NOT A BAD DAY FOR THU OR FRI...AS HIGH PRESSURE BUILDS INTO
THE AREA.
PERHAPS A FEW RAIN AND SNOW SHOWERS FOR LATE IN THE WEEK WITH
THE NEXT COLD FRONT.
NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS
HEIGHTS ARE FORECAST TO RISE AND A LOW PRESSURE SYSTEM LIFTS
THROUGH THE GREAT LAKES TO THE WEST OF PA.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
ARCTIC AIR HAS BROUGHT COLD TEMPERATURES AND STRONG GUSTY WINDS TO
THE REGION. SNOW SQUALLS ARE COMMON IN THE WESTERN MOUNTAINS WITH
IMPACTS ON KJST AND KBFD. SOME OF THE STRONGER LAKE STREAMERS AND
SNOW SHOWERS HAVE MADE TO THE MARYLAND BORDER IN SOUTHEASTERN PA.
SO SNOW AND BLOWING SNOW IS POSSIBLE WITH THE STRONG GUSTY WINDS.
GOOD GUST SPREADS TOO WHICH AFFECT TAKEOFF/LANDINGS. GUSTS OVER
30KTS HAVE BEEN OBSERVED.
IFR AND MVFR MOST OF WEST. VFR WITH TIME MVFR IN CENTRAL AREAS.
MOSTLY VFR WITH TIMES MVFR WITH SNOW/BLOWING SNOW IN SOME PARTS
OF SOUTHEAST TODAY.
THE SNOW SHOWERS AND WINDS WILL DIMINISH THIS EVENING AND
OVERNIGHT. THINGS SHOULD BE MUCH NICER SUNDAY...THOUGH A TAD COLD.
NEED A HEATED JOY STICK.
HIGH PRESSURE SUNDAY DRIFTS EAST OVERNIGHT SO THE PERIOD OF NICE
WEATHER WITH VFR WILL BE SHORT LIVED AS CLOUDS AND POTENTIAL
PRECIPITATION MOVE IN FOR MONDAY AND INTO TUESDAY. SNOW AND
ASSORTED WINTRY PRECIPITATION WILL LIKELY AFFECT FLYING MONDAY
INTO TUESDAY.
OUTLOOK...
SUN...NO SIG WX EXPECTED MAINLY VFR.
MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING.
MON NIGHT AND TUE...SNOW LIKELY WRN HALF OF PENN...WITH RAIN
AND/OR SNOW IN THE SE. WIDESPREAD RESTRICTIONS SET IN. LLWS POSS
SE.
WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN
PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST.
THU...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037-
041-042.
WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-
017>019-024>028-033>036-045-046-049>053-056>059-063>066.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM/DANGELO
SHORT TERM...GRUMM
LONG TERM...FITZGERALD/GARTNER/MARTIN
AVIATION...GRUMM/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
806 PM EST SAT FEB 13 2016
.SYNOPSIS...
THE POLAR VORTEX PUSHED ARCTIC AIR INTO THE REGION FOR THE
WEEKEND. A STRONG BUT FAST MOVING SURFACE HIGH WILL MOVE THROUGH
THE REGION BEHIND THE VORTEX. SOUTHWESTERLY FLOW ALOFT WILL ALLOW
MOISTURE AND A STORM SYSTEM TO BRING SNOW AND A WINTRY MIX TO THE
REGION MONDAY INTO TUESDAY. LATER IN THE WEEK A RIDGE MOVES IN
ALOFT WITH MUCH WARMER AIR FORECAST LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 7 AM SUNDAY MORNING/...
8 PM UPDATE...
SNOW BANDS CONTINUE RUNNING NW-SE THRU THE AREA. INTERESTING TO
NOTE THAT THE HRRR AND RAP BOTH MAKE THE LONG BAND THRU THE
CENTRAL MTNS REACH DOWN INTO LEBANON AND LANCASTER COUNTIES ON THE
BERKS BORDER. THIS IS VERY NEARLY THE LOCATION OF THE BIG ACCIDENT
EARLIER TODAY. THE SHSN DO APPEAR TO DISSIPATE BY MIDNIGHT...THO.
WILL KEEP POPS IN FOR MOST PLACE FOR THE TIME BEING BUT CALL
ADDTNL ACCUMS LESS THAN AN INCH EVERYWHERE.
PREV...
OVERNIGHT THE MASSIVE SURFACE HIGH MOVES IN SHOULD BE OVERHEAD BY
SUNDAY MORNING. THIS WILL LOWER THE INVERSION HEIGHT...SHUTTING
OFF THE SNOW SHOWERS THIS EVENING AND EARLY TONIGHT AND SHUTTING
DOWN THE WINDS. THE LIGHT WINDS BEFORE SUNRISE COULD SQUEEZE OUT A
FEW MORE DEGREES OF RADIATIONAL COOLING. GOING TO BE A VERY COLD
MORNING. MANY LOCATIONS WILL LIKELY HAVE THEIR COLDEST OVERNIGHT
LOW OF THE SEASON.
&&
.SHORT TERM /7 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE IN CONTROL. WINDS SLACKEN AND TEMPS ONLY AS MILD AS
SAT...BUT SHOULD FEEL BETTER.
THE HIGH MOVES RAPIDLY TO THE EAST LATE SUNDAY NIGHT. EARLY
RADIATIONAL COOLING SHOULD DROP TEMPERATURES OFF FAST SUNDAY
EVENING. BUT RETURN FLOW COULD CAUSE TEMPERATURES TO BEGIN TO
SLOWLY RISE SUNDAY NIGHT INTO MONDAY MORNING.
GOING TO BE INTERESTING MONDAY-TUESDAY WEATHER!
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
*IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT
WEEK.
DID NOT CHANGE MUCH FOR MONDAY...TUE FRAME.
MAIN THING WAS TO INSERT SOME ZR INTO THE GRIDS AFTER 00Z
TUE...THROUGH LATE TUESDAY MORNING. BASED ON WPC GRAPHICS.
ALSO DID UP POPS SOME.
DID NOT DO A LOT WITH SNOW AMTS SO FAR. MAY ADJUST MORE LATER.
EC MAY BE TO FAR WEST...BUT EITHER WAY...EXPECT SOME SNOW TO
PILE UP ACROSS SOUTH CENTRAL PA BY LATE MONDAY AFT...ABOUT
1 TO 2 INCHES...AS SYSTEM LIFTS NE FAST...AND WARM ADVECTION
WAITS FOR NO MAN.
MORE DETAIL BELOW.
CLOUDS AND POTENTIAL LIGHT SNOW COULD ARRIVE IN SOUTHWESTERN
AREAS MONDAY MORNING AS INDICATED IN SOME ENSEMBLE FORECASTS.
BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT
SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER
SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE
BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND
ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD
CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS
EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS
EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL
UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST
FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE
LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS.
WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS
EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL
ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A
POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS
HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY.
EXPECT BULK OF PCPN TO BE OUT OF THE AREA BY LATE TUE AM.
ANOTHER COLD FRONT WED. DID UP POPS SOME ACROSS THE WEST.
MOISTURE IS LIMITED.
NOT A BAD DAY FOR THU OR FRI...AS HIGH PRESSURE BUILDS INTO
THE AREA.
PERHAPS A FEW RAIN AND SNOW SHOWERS FOR LATE IN THE WEEK WITH
THE NEXT COLD FRONT.
NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS
HEIGHTS ARE FORECAST TO RISE AND A LOW PRESSURE SYSTEM LIFTS
THROUGH THE GREAT LAKES TO THE WEST OF PA.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
ARCTIC AIR HAS BROUGHT COLD TEMPERATURES AND STRONG GUSTY WINDS TO
THE REGION. SNOW SQUALLS ARE COMMON IN THE WESTERN MOUNTAINS WITH
IMPACTS ON KJST AND KBFD. SOME OF THE STRONGER LAKE STREAMERS AND
SNOW SHOWERS HAVE MADE TO THE MARYLAND BORDER IN SOUTHEASTERN PA.
SO SNOW AND BLOWING SNOW IS POSSIBLE WITH THE STRONG GUSTY WINDS.
GOOD GUST SPREADS TOO WHICH AFFECT TAKEOFF/LANDINGS. GUSTS OVER
30KTS HAVE BEEN OBSERVED.
IFR AND MVFR MOST OF WEST. VFR WITH TIME MVFR IN CENTRAL AREAS.
MOSTLY VFR WITH TIMES MVFR WITH SNOW/BLOWING SNOW IN SOME PARTS
OF SOUTHEAST TODAY.
THE SNOW SHOWERS AND WINDS WILL DIMINISH THIS EVENING AND
OVERNIGHT. THINGS SHOULD BE MUCH NICER SUNDAY...THOUGH A TAD COLD.
NEED A HEATED JOY STICK.
HIGH PRESSURE SUNDAY DRIFTS EAST OVERNIGHT SO THE PERIOD OF NICE
WEATHER WITH VFR WILL BE SHORT LIVED AS CLOUDS AND POTENTIAL
PRECIPITATION MOVE IN FOR MONDAY AND INTO TUESDAY. SNOW AND
ASSORTED WINTRY PRECIPITATION WILL LIKELY AFFECT FLYING MONDAY
INTO TUESDAY.
OUTLOOK...
SUN...NO SIG WX EXPECTED MAINLY VFR.
MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING.
MON NIGHT AND TUE...SNOW LIKELY WRN HALF OF PENN...WITH RAIN
AND/OR SNOW IN THE SE. WIDESPREAD RESTRICTIONS SET IN. LLWS POSS
SE.
WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN
PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST.
THU...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037-
041-042.
WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-
017>019-024>028-033>036-045-046-049>053-056>059-063>066.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM/DANGELO
SHORT TERM...GRUMM
LONG TERM...FITZGERALD/GARTNER/MARTIN
AVIATION...GRUMM/MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1208 PM EST FRI FEB 12 2016
.SYNOPSIS...
A FAST MOVING UPPER LEVEL DISTURBANCE WILL BRING A BRIEF CHANCE OF
PRECIPITATION TO MUCH OF THE AREA TODAY. A STRONG DOME OF CANADIAN
HIGH PRESSURE WILL SETTLE IN OVER THE WEEKEND...USHERING IN ANOTHER
PERIOD OF COLD TEMPERATURES. THIS WILL BE FOLLOWED BY ANOTHER
WEATHER SYSTEM WHICH WILL PRODUCE A BETTER CHANCE OF PRECIPITATION
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1715 UTC...POPS WERE ADJUSTED BASED ON RADAR TRENDS...FAVORING A
BAND OF SNOW FROM GREENVILLE AND SPARTANBURG TO JUST SOUTH OF
CHARLOTTE. WINDS WERE UPDATED WITH A BLEND OF THE NAM AND ADJMAV...
ALLOWING GUSTS TO INCREASE LATER TODAY AS A SURFACE LOW MOVES OFF THE
COAST AND A TIGHT PRESSURE GRADIENT MOVES IN FROM THE WEST.
1500 UTC UPDATE...POPS HAVE BEEN ADJUSTED TO ACCOUNT FOR LIGHT SNOW
MOVING ACROSS UPSTATE NC. WINDS WERE UPDATED TO INCLUDE THE LATEST
NAM GUIDANCE...WITH GUSTS INCREASING AT HIGHER MC MOUNTAIN ELEVATIONS
LATER TODAY. ONLY MINOR ADJUSTMENTS WERE MADE TO MAXIMUM
TEMPERATURES.
AS OF 650 AM...THE MODELS SEEM TO BE LATCHING ONTO MORE MOISTURE OR
BETTER LLVL LIFT EAST OF THE MTNS. THE 6Z GFS AND THE LATEST RAP AND
HRRR NOW HAVE HIGHER POP/MORE COVERAGE OF SNOW SHOWERS ACROSS THE
PIEDMONT. IT LOOKS LIKE A BAND MAY SET UP SOMEWHERE ACROSS THE
UPSTATE. HOWEVER...CONFIDENCE IS STILL LOW. POPS MAY NEED TO BE
ADJUSTED UPWARD IF TRENDS ON RADAR LOOK TO BE LINING UP WITH THE
HRRR. OTHERWISE...FCST LOOKS ON TRACK.
AS OF 315 AM...A VIGOROUS SHORT WAVE CAN BE SEEN ON WATER VAPOR
IMAGERY DIVING INTO THE OHIO VALLEY TOWARD THE BASE OF A LONG WAVE
TROF ALONG THE EAST COAST. THIS WAVE WILL CROSS THE CWFA JUST AFTER
DAYBREAK...AND WILL BE ACCOMPANIED BY A 130 KT 300 MB JET. THIS WILL
RESULT IN STRONG MID AND UPPER LEVEL FORCING FROM ABOUT 12Z TO 18Z
TODAY. AT THE SFC...A WEAK ALBERTA CLIPPER WAS ANALYZED OVER
MO...AND WILL STREAK JUST SOUTH OF THE CWFA DURING THE DAY. LLVL FLOW
IS BACKING OUT OF THE WSW...BUT STRUGGLING TO TAP INTO MUCH MOISTURE.
SO THE FORECAST CHALLENGE FOR TODAY WILL BE HOW MUCH QPF WILL
ACCOMPANY THE SYSTEM...AS THE OP MODELS SHOW SOME SPREAD ON COVERAGE
AND AMOUNTS. THE 00Z NAM KEEPS THE PIEDMONT DRY...WHILE THE
OTHER OP MODELS HAVE SOME LIGHT AMOUNTS. I LIKE THE AGREEMENT OF THE
CAMS ON THE SIMULATED REFLECTIVITY...SHOWING LIGHT PRECIP BREAKING
OUT ACRS THE MTNS RIGHT AROUND DAYBREAK...THEN QUICKLY SPREADING
EAST ACROSS THE PIEDMONT DURING THE LATE MORNING HOURS. BY EARLY
AFTN...THE MODELS SHOW PRECIP CONFINED TO WESTERLY UPSLOPE AREAS
ALONG THE TN BORDER. I THINK MUCH OF WHAT THE CAMS ARE SHOWING WOULD
BE VIRGA...GIVEN THE MOISTURE MAINLY IN THE MID LEVELS. SO POPS SHOW
LIKELY IN THE MTNS...ESP NEAR THE TN BORDER...WHILE ONLY SLIGHT
CHANCE TO LOW-END CHANCE EAST. FCST PROFILES SHOW THAT THIS WOULD BE
A RAIN/SNOW EVENT...WITH WET-BULB EFFECTS ALLOWING FOR LIGHT SNOW
SHOWERS AND/OR FLURRIES JUST ABOUT ANYWHERE THIS MORNING. ACCUMS
THRU THE DAY WILL BE IN THE MTNS...WITH NOTHING MORE THAN A DUSTING
EXPECTED ELSEWHERE. TEMPS SHOULD BE ABOUT 10-15 DEGREES BELOW NORMAL
UNDER MOSTLY CLOUDY SKIES AND SPOTTY PRECIP.
TONIGHT...THE CLIPPER SYSTEM WILL ALREADY BE DEVELOPING A NEW LOW
OUT OVER THE ATLANTIC JUST EAST OF THE OUTER BANKS BY EARLY
EVENING...WHILE A STRONG ARCTIC HIGH (PRESSURE AROUND 1044 MB)
BUILDS IN ACROSS THE PLAINS TO THE SOUTHEAST STATES. THE SFC
PRESSURE GRADIENT NEVER GETS THAT IMPRESSIVE ATOP THE CWFA.
HOWEVER...THE 850 MB FLOW RAMPS UP OUT OF THE NW TO 40-55 KT ACROSS
THE NC MTNS WITH VERY STRONG CAA. THIS WILL RESULT IN A DOWN RIGHT
COLD AND BLUSTERY NIGHT IN THE MTNS...WITH THE ADDITION OF LINGERING
MOISTURE FOR NW FLOW SNOW SHOWERS. IN FACT...THE COLD AIR AND NEAR
PERFECT ORTHOGOTHAL DIRECTION COULD MAKE FOR EFFICIENT SNOW
PRODUCING SHOWERS ALONG THE TN LINE. THE EXPECTED SNOW WITH THE
CLIPPER ALONG WITH THE NW FLOW SNOW SHOULD RESULT IN TOTAL ACCUMS OF
2-4" ACROSS THE USUAL NW FLOW UPSLOPE AREAS. THIS ALONG WITH WINDS
IN THE 25-40 MPH RANGE AND GUSTS IN THE 40-55 MPH RANGE SEEMS TO
WARRANT A WINTER WEATHER ADVISORY. I WILL START IT AT NOON TO
EMCOMPASS THE SNOW ACCUMS EXPECTED TODAY...AND GO THRU 6 AM SATURDAY
(WHEN SNOW SHOWER ACTIVITY WILL TAPER OFF). IN ADDITION...TEMPS WILL
BE PLUMMETING INTO THE TEENS TO SINGLE DIGITS...SO WIND CHILLS WILL
BE IN THE -5 TO -15 F RANGE FOR MOST LOCATIONS ABOVE 3500 FT. A WIND
CHILL ADVISORY WILL BE ISSUED STARTING AT MIDNIGHT...ALTHOUGH SOME
LOCATIONS ABOVE 5000 FT OR SO MAY START SEEING DANGEROUS WIND CHILLS
EARLIER IN THE EVENING. THE REST OF THE CWFA SHOULD SEE CLEARING
SKIES AND LINGERING WINDS WITH CHILLY TEMPS ABOUT 8-15 DEGREES BELOW
NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM EST FRIDAY...A BROAD TROUGH OF LOW PRESSURE WILL EXTEND
SOUTHWARD ACROSS THE EASTERN UNITED STATES SATURDAY FROM A LOW
CENTER OVER SOUTHERN QUEBEC. ISOLATED TO SCATTERED NW FLOW SNOW
SHOWERS COULD LINGER ACROSS THE NORTHERN MOUNTAINS EARLY
SATURDAY...BUT WITH MOISTURE DIMINISHING THROUGH THE DAY. COLD
MORNING TEMPERATURES AND BRISK NW FLOW WILL PERMIT BITTER WIND
CHILLS TO CONTINUE THROUGH SATURDAY MORNING ACROSS THE
MOUNTAINS...AND ON INTO SATURDAY NIGHT/SUNDAY MORNING ACROSS THE
NORTHERN MOUNTAINS. MEANWHILE...VERY COLD AIR WILL DIVE SOUTHEAST
FROM CANADA INTO THE REGION ON THE BACK SIDE OF THE TROUGH AS THE
ASSOCIATED ARCTIC HIGH PRESSURE MOVES ACROSS THE MIDWEST ON SATURDAY
AND REACHES THE EASTERN SEABOARD BY LATE SUNDAY. IN THE COLD
AIRMASS...MAX TEMPERATURES WILL RUN AT LEAST 20 DEGREES BELOW CLIMO
IN MOST AREAS...WHILE SUNDAY MORNING MINS WILL BE 10 TO 20 DEGREES
BELOW CLIMO. A WIND CHILL ADVISORY WILL CONTINUE UNTIL MID SUNDAY
MORNING ACROSS THE NORTHERN NC MOUNTAINS.
THE UPPER FLOW WILL FLATTEN SLIGHTLY OVER THE EAST ON SUNDAY AS A
NORTHERN STREAM SHORTWAVE DIGS INTO THE MIDWEST WHILE A SOUTHERN
STREAM SYSTEM TAKES SHAPE FROM THE FOUR CORNERS REGION TOWARD TX.
THE FIRST HINT OF MID LEVEL UPGLIDE MOISTURE WILL ARRIVE IN THE CWA
FROM THE WEST ON SUNDAY...BUT WITH DRY LOW LEVELS PRECLUDING ANY
PRECIPITATION FROM REACHING THE GROUND THROUGH LATE DAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 300 AM EST FRIDAY...A WINTRY MIXED MAG OF PRECIPITATION IS
LOOKING LIKELY STARTING SUNDAY NIGHT INTO MONDAY GIVEN THE VERY COLD
AND DRY AIRMASS THAT WILL BE PRESENT OVER THE AREA BEFORE ONSET.
THERE IS GOOD MODEL CONSENSUS ON THE ENERGY WITH THE SOUTHERN STREAM
SYSTEM SHARPENING UP RAPIDLY OVER THE LOWER MS RIVER VALLEY SUNDAY
NIGHT INTO MONDAY. MEANWHILE...THE SURFACE HIGH CENTER TO THE NORTH
WILL RETREAT OFFSHORE. LOW LEVEL UPGLIDE MOISTURE WILL FILL IN
RAPIDLY ACROSS OUR AREA EARLY MONDAY...WITH THE 850 MB ZERO ISOTHERM
ALONG THE SOUTHERN FRINGE OF THE AREA AROUND DAYBREAK MOVING RAPIDLY
TOWARD THE NORTHERN FRINGE OF THE FORECAST AREA BY MID AFTERNOON.
EVEN THOUGH COLD AIR DAMMING IS VERY LIKELY...THE COLD AIR MAY ONLY
STAY DEEPLY ENTRENCHED EAST OF THE NORTHERN BLUE RIDGE GIVEN THE
INCREASINGLY OFFSHORE PARENT HIGH LOCATION. STILL...PROFILES ARE
PLENTY COLD FOR PRECIPITATION TO START AS SNOW THROUGHOUT BEFORE
DAYBREAK MONDAY...WITH A BLOSSOMING WARM NOSE THEN INVADING THE
SOUTHERN TIER OF THE FORECAST AREA MONDAY MORNING AND MOVING
NORTHWARD ACROSS THE REGION THROUGH THE DAY.
THE BEST UPPER FORCING ACTUALLY ARRIVES MONDAY NIGHT AS UPPER JET
DIVERGENCE BRIEFLY SETS UP AND DEEP LAYER Q VECTOR FORCING CROSSES
THE REGION AHEAD OF THE INCREASINGLY NEGATIVE TILT UPPER TROUGH.
FORCING AND MOISTURE WILL BE STRONGLY FOCUSED ON THE REGION LATE
MONDAY NIGHT/EARLY TUESDAY WITH THE SURFACE LOW CENTER LIKELY
TRACKING THROUGH THE CENTRAL CAROLINAS...THE CAD GETTING FURTHER
PINCHED OFF TO THE NORTH...AND THE HEAVIEST PRECIPITATION DURING THE
WARMEST PART OF THE EPISODE.
SO...THERE ARE PLENTY OF POTENTIAL HAZARDS. SIGNIFICANT ICE AND SNOW
ACCUMULATIONS WILL BE POSSIBLE...MAINLY OVER WESTERN NC AND
ESPECIALLY ALONG AND NORTH OF INTERSTATE 40. IN ADDITION...HEAVY QPF
COULD CREATE SOME HYDRO ISSUES MONDAY NIGHT INTO TUESDAY MORNING
WITH THE FRONTOGENESIS MAX WEST OF THE PASSING 850 MB LOW LIKELY
LINGERING OVER THE EASTERN SLOPES OF THE MOUNTAIN. THE HEAVY
RAINFALL ON TOP OF ACCUMULATED SNOW AND ICE COULD CREATE SOME LOCAL
ICE DAMMING PROBLEMS ON SHALLOW SLOPED ROOFS. FINALLY...SURFACE
BASED CAPE VALUES OF 200 TO 300 J/KG ARE POSSIBLE TOWARD DAYBREAK
TUESDAY IN THE LOWER PIEDMONT...WITH 850 TO 500 MB LAPSE RATES OF
6.5 TO 7.0 DEG C/KM...ALONG WITH BACKED 50 KT 850 MB FLOW. THIS
COULD CREATE A BRIEF SEVERE THUNDERSTORM THREAT FROM CHESTER TO
MONROE OR THEREABOUTS AROUND DAYBREAK TUESDAY. OTHERWISE...DRYING
WILL DEVELOP FROM THE SOUTHWEST THROUGH TUESDAY AFTERNOON...WITH
NORTHERN MOUNTAIN UPSLOPE MOISTURE BRIEFLY DRYING UP.
A REINFORCING CLIPPER MAY DIVE INTO THE MEAN EASTERN TROUGH TUESDAY
NIGHT...WITH THE GFS MORE AMPLIFIED THAN THE ECMWF...PRODUCING
MAINLY ADDITIONAL UPSLOPE SNOW SHOWER COVERAGE OVER THE WESTERN
MOUNTAINS. HEIGHTS WILL BUILD EASTWARD FROM THE BROAD WESTERN RIDGE
WEDNESDAY THROUGH THURSDAY...WITH ASSOCIATED WARMING AND DRYING.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
AT KCLT...SNOWFALL REMAINS POSSIBLE VERY EARLY IN THE FORECAST...
WITH RESULTING VSBY AND CIG RESTRICTIONS. IMPROVEMENT IS EXPECTED
THIS AFTERNOON...AS SNOW MOVES OFF TO THE EAST. NE WINDS ARE EXPECTED
TO SHIFT TO SW THIS AFTERNOON...THEN VEER NW THIS EVENING BEHIND A
DEPARTING LOW PRESSURE SYSTEM. WIND GUST POTENTIAL WILL INCREASE
OVERNIGHT AND EARLY TUESDAY.
AT KAVL...SNOW SHOWERS WITH CIG AND VSBY RESTRICTIONS MAY LINGER IN
THE VICINITY THIS AFTERNOON AND EVENING...BACKING OFF TOWARD THE TN
BORDER TOWARD DAWN. NW WINDS WILL INCREASE AS A LOW PRESSURE SYSTEM
DEPARTS AND THE PRESSURE GRADIENT TIGHTENS AHEAD OF HIGH PRESSURE.
ELSEWHERE...SNOW SHOWERS WILL MOVE OFF TO THE EAST...WITH CIGS AND
VSBY IMPROVING. WINDS WILL FAVOR THE W THIS AFTERNOON AND
EVENING...VEERING NW OVERNIGHT...WITH GUST POTENTIAL GRADUALLY
INCREASING.
OUTLOOK...AN ARCTIC AIR MASS WILL BUILD OVER THE REGION THIS
WEEKEND...WITH UPSLOPE CLOUDS ON THE WEST SIDE OF THE APPALACHIANS.
A SIGNIFICANT WINTER WEATHER SYSTEM IS POSSIBLE EARLY NEXT WEEK.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-12Z
KCLT MED 71% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KAND LOW 57% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WINTER WEATHER ADVISORY UNTIL 6 AM EST SATURDAY FOR NCZ033-
048>052.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST SUNDAY
FOR NCZ033-049-050.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY
FOR NCZ048-051-052-058-059.
SC...NONE.
&&
$$
SYNOPSIS...HG
NEAR TERM...ARK/JAT
SHORT TERM...HG
LONG TERM...HG
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1001 AM EST FRI FEB 12 2016
.SYNOPSIS...
A FAST MOVING UPPER LEVEL DISTURBANCE WILL BRING A BRIEF CHANCE OF
PRECIPITATION TO MUCH OF THE AREA TODAY. A STRONG DOME OF CANADIAN
HIGH PRESSURE WILL SETTLE IN OVER THE WEEKEND...USHERING IN ANOTHER
PERIOD OF COLD TEMPERATURES. THIS WILL BE FOLLOWED BY ANOTHER
WEATHER SYSTEM WHICH WILL PRODUCE A BETTER CHANCE OF PRECIPITATION
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1500 UTC UPDATE...POPS HAVE BEEN ADJUSTED TO ACCOUNT FOR LIGHT SNOW
MOVING ACROSS UPSTATE NC. WINDS WERE UPDATED TO INCLUDE THE LATEST
NAM GUIDANCE...WITH GUSTS INCREASING AT HIGHER MC MOUNTAIN ELEVATIONS
LATER TODAY. ONLY MINOR ADJUSTMENTS WERE MADE TO MAXIMUM
TEMPERATURES.
AS OF 650 AM...THE MODELS SEEM TO BE LATCHING ONTO MORE MOISTURE OR
BETTER LLVL LIFT EAST OF THE MTNS. THE 6Z GFS AND THE LATEST RAP AND
HRRR NOW HAVE HIGHER POP/MORE COVERAGE OF SNOW SHOWERS ACROSS THE
PIEDMONT. IT LOOKS LIKE A BAND MAY SET UP SOMEWHERE ACROSS THE
UPSTATE. HOWEVER...CONFIDENCE IS STILL LOW. POPS MAY NEED TO BE
ADJUSTED UPWARD IF TRENDS ON RADAR LOOK TO BE LINING UP WITH THE
HRRR. OTHERWISE...FCST LOOKS ON TRACK.
AS OF 315 AM...A VIGOROUS SHORT WAVE CAN BE SEEN ON WATER VAPOR
IMAGERY DIVING INTO THE OHIO VALLEY TOWARD THE BASE OF A LONG WAVE
TROF ALONG THE EAST COAST. THIS WAVE WILL CROSS THE CWFA JUST AFTER
DAYBREAK...AND WILL BE ACCOMPANIED BY A 130 KT 300 MB JET. THIS WILL
RESULT IN STRONG MID AND UPPER LEVEL FORCING FROM ABOUT 12Z TO 18Z
TODAY. AT THE SFC...A WEAK ALBERTA CLIPPER WAS ANALYZED OVER
MO...AND WILL STREAK JUST SOUTH OF THE CWFA DURING THE DAY. LLVL FLOW
IS BACKING OUT OF THE WSW...BUT STRUGGLING TO TAP INTO MUCH MOISTURE.
SO THE FORECAST CHALLENGE FOR TODAY WILL BE HOW MUCH QPF WILL
ACCOMPANY THE SYSTEM...AS THE OP MODELS SHOW SOME SPREAD ON COVERAGE
AND AMOUNTS. THE 00Z NAM KEEPS THE PIEDMONT DRY...WHILE THE
OTHER OP MODELS HAVE SOME LIGHT AMOUNTS. I LIKE THE AGREEMENT OF THE
CAMS ON THE SIMULATED REFLECTIVITY...SHOWING LIGHT PRECIP BREAKING
OUT ACRS THE MTNS RIGHT AROUND DAYBREAK...THEN QUICKLY SPREADING
EAST ACROSS THE PIEDMONT DURING THE LATE MORNING HOURS. BY EARLY
AFTN...THE MODELS SHOW PRECIP CONFINED TO WESTERLY UPSLOPE AREAS
ALONG THE TN BORDER. I THINK MUCH OF WHAT THE CAMS ARE SHOWING WOULD
BE VIRGA...GIVEN THE MOISTURE MAINLY IN THE MID LEVELS. SO POPS SHOW
LIKELY IN THE MTNS...ESP NEAR THE TN BORDER...WHILE ONLY SLIGHT
CHANCE TO LOW-END CHANCE EAST. FCST PROFILES SHOW THAT THIS WOULD BE
A RAIN/SNOW EVENT...WITH WET-BULB EFFECTS ALLOWING FOR LIGHT SNOW
SHOWERS AND/OR FLURRIES JUST ABOUT ANYWHERE THIS MORNING. ACCUMS
THRU THE DAY WILL BE IN THE MTNS...WITH NOTHING MORE THAN A DUSTING
EXPECTED ELSEWHERE. TEMPS SHOULD BE ABOUT 10-15 DEGREES BELOW NORMAL
UNDER MOSTLY CLOUDY SKIES AND SPOTTY PRECIP.
TONIGHT...THE CLIPPER SYSTEM WILL ALREADY BE DEVELOPING A NEW LOW
OUT OVER THE ATLANTIC JUST EAST OF THE OUTER BANKS BY EARLY
EVENING...WHILE A STRONG ARCTIC HIGH (PRESSURE AROUND 1044 MB)
BUILDS IN ACROSS THE PLAINS TO THE SOUTHEAST STATES. THE SFC
PRESSURE GRADIENT NEVER GETS THAT IMPRESSIVE ATOP THE CWFA.
HOWEVER...THE 850 MB FLOW RAMPS UP OUT OF THE NW TO 40-55 KT ACROSS
THE NC MTNS WITH VERY STRONG CAA. THIS WILL RESULT IN A DOWN RIGHT
COLD AND BLUSTERY NIGHT IN THE MTNS...WITH THE ADDITION OF LINGERING
MOISTURE FOR NW FLOW SNOW SHOWERS. IN FACT...THE COLD AIR AND NEAR
PERFECT ORTHOGOTHAL DIRECTION COULD MAKE FOR EFFICIENT SNOW
PRODUCING SHOWERS ALONG THE TN LINE. THE EXPECTED SNOW WITH THE
CLIPPER ALONG WITH THE NW FLOW SNOW SHOULD RESULT IN TOTAL ACCUMS OF
2-4" ACROSS THE USUAL NW FLOW UPSLOPE AREAS. THIS ALONG WITH WINDS
IN THE 25-40 MPH RANGE AND GUSTS IN THE 40-55 MPH RANGE SEEMS TO
WARRANT A WINTER WEATHER ADVISORY. I WILL START IT AT NOON TO
EMCOMPASS THE SNOW ACCUMS EXPECTED TODAY...AND GO THRU 6 AM SATURDAY
(WHEN SNOW SHOWER ACTIVITY WILL TAPER OFF). IN ADDITION...TEMPS WILL
BE PLUMMETING INTO THE TEENS TO SINGLE DIGITS...SO WIND CHILLS WILL
BE IN THE -5 TO -15 F RANGE FOR MOST LOCATIONS ABOVE 3500 FT. A WIND
CHILL ADVISORY WILL BE ISSUED STARTING AT MIDNIGHT...ALTHOUGH SOME
LOCATIONS ABOVE 5000 FT OR SO MAY START SEEING DANGEROUS WIND CHILLS
EARLIER IN THE EVENING. THE REST OF THE CWFA SHOULD SEE CLEARING
SKIES AND LINGERING WINDS WITH CHILLY TEMPS ABOUT 8-15 DEGREES BELOW
NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM EST FRIDAY...A BROAD TROUGH OF LOW PRESSURE WILL EXTEND
SOUTHWARD ACROSS THE EASTERN UNITED STATES SATURDAY FROM A LOW
CENTER OVER SOUTHERN QUEBEC. ISOLATED TO SCATTERED NW FLOW SNOW
SHOWERS COULD LINGER ACROSS THE NORTHERN MOUNTAINS EARLY
SATURDAY...BUT WITH MOISTURE DIMINISHING THROUGH THE DAY. COLD
MORNING TEMPERATURES AND BRISK NW FLOW WILL PERMIT BITTER WIND
CHILLS TO CONTINUE THROUGH SATURDAY MORNING ACROSS THE
MOUNTAINS...AND ON INTO SATURDAY NIGHT/SUNDAY MORNING ACROSS THE
NORTHERN MOUNTAINS. MEANWHILE...VERY COLD AIR WILL DIVE SOUTHEAST
FROM CANADA INTO THE REGION ON THE BACK SIDE OF THE TROUGH AS THE
ASSOCIATED ARCTIC HIGH PRESSURE MOVES ACROSS THE MIDWEST ON SATURDAY
AND REACHES THE EASTERN SEABOARD BY LATE SUNDAY. IN THE COLD
AIRMASS...MAX TEMPERATURES WILL RUN AT LEAST 20 DEGREES BELOW CLIMO
IN MOST AREAS...WHILE SUNDAY MORNING MINS WILL BE 10 TO 20 DEGREES
BELOW CLIMO. A WIND CHILL ADVISORY WILL CONTINUE UNTIL MID SUNDAY
MORNING ACROSS THE NORTHERN NC MOUNTAINS.
THE UPPER FLOW WILL FLATTEN SLIGHTLY OVER THE EAST ON SUNDAY AS A
NORTHERN STREAM SHORTWAVE DIGS INTO THE MIDWEST WHILE A SOUTHERN
STREAM SYSTEM TAKES SHAPE FROM THE FOUR CORNERS REGION TOWARD TX.
THE FIRST HINT OF MID LEVEL UPGLIDE MOISTURE WILL ARRIVE IN THE CWA
FROM THE WEST ON SUNDAY...BUT WITH DRY LOW LEVELS PRECLUDING ANY
PRECIPITATION FROM REACHING THE GROUND THROUGH LATE DAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 300 AM EST FRIDAY...A WINTRY MIXED MAG OF PRECIPITATION IS
LOOKING LIKELY STARTING SUNDAY NIGHT INTO MONDAY GIVEN THE VERY COLD
AND DRY AIRMASS THAT WILL BE PRESENT OVER THE AREA BEFORE ONSET.
THERE IS GOOD MODEL CONSENSUS ON THE ENERGY WITH THE SOUTHERN STREAM
SYSTEM SHARPENING UP RAPIDLY OVER THE LOWER MS RIVER VALLEY SUNDAY
NIGHT INTO MONDAY. MEANWHILE...THE SURFACE HIGH CENTER TO THE NORTH
WILL RETREAT OFFSHORE. LOW LEVEL UPGLIDE MOISTURE WILL FILL IN
RAPIDLY ACROSS OUR AREA EARLY MONDAY...WITH THE 850 MB ZERO ISOTHERM
ALONG THE SOUTHERN FRINGE OF THE AREA AROUND DAYBREAK MOVING RAPIDLY
TOWARD THE NORTHERN FRINGE OF THE FORECAST AREA BY MID AFTERNOON.
EVEN THOUGH COLD AIR DAMMING IS VERY LIKELY...THE COLD AIR MAY ONLY
STAY DEEPLY ENTRENCHED EAST OF THE NORTHERN BLUE RIDGE GIVEN THE
INCREASINGLY OFFSHORE PARENT HIGH LOCATION. STILL...PROFILES ARE
PLENTY COLD FOR PRECIPITATION TO START AS SNOW THROUGHOUT BEFORE
DAYBREAK MONDAY...WITH A BLOSSOMING WARM NOSE THEN INVADING THE
SOUTHERN TIER OF THE FORECAST AREA MONDAY MORNING AND MOVING
NORTHWARD ACROSS THE REGION THROUGH THE DAY.
THE BEST UPPER FORCING ACTUALLY ARRIVES MONDAY NIGHT AS UPPER JET
DIVERGENCE BRIEFLY SETS UP AND DEEP LAYER Q VECTOR FORCING CROSSES
THE REGION AHEAD OF THE INCREASINGLY NEGATIVE TILT UPPER TROUGH.
FORCING AND MOISTURE WILL BE STRONGLY FOCUSED ON THE REGION LATE
MONDAY NIGHT/EARLY TUESDAY WITH THE SURFACE LOW CENTER LIKELY
TRACKING THROUGH THE CENTRAL CAROLINAS...THE CAD GETTING FURTHER
PINCHED OFF TO THE NORTH...AND THE HEAVIEST PRECIPITATION DURING THE
WARMEST PART OF THE EPISODE.
SO...THERE ARE PLENTY OF POTENTIAL HAZARDS. SIGNIFICANT ICE AND SNOW
ACCUMULATIONS WILL BE POSSIBLE...MAINLY OVER WESTERN NC AND
ESPECIALLY ALONG AND NORTH OF INTERSTATE 40. IN ADDITION...HEAVY QPF
COULD CREATE SOME HYDRO ISSUES MONDAY NIGHT INTO TUESDAY MORNING
WITH THE FRONTOGENESIS MAX WEST OF THE PASSING 850 MB LOW LIKELY
LINGERING OVER THE EASTERN SLOPES OF THE MOUNTAIN. THE HEAVY
RAINFALL ON TOP OF ACCUMULATED SNOW AND ICE COULD CREATE SOME LOCAL
ICE DAMMING PROBLEMS ON SHALLOW SLOPED ROOFS. FINALLY...SURFACE
BASED CAPE VALUES OF 200 TO 300 J/KG ARE POSSIBLE TOWARD DAYBREAK
TUESDAY IN THE LOWER PIEDMONT...WITH 850 TO 500 MB LAPSE RATES OF
6.5 TO 7.0 DEG C/KM...ALONG WITH BACKED 50 KT 850 MB FLOW. THIS
COULD CREATE A BRIEF SEVERE THUNDERSTORM THREAT FROM CHESTER TO
MONROE OR THEREABOUTS AROUND DAYBREAK TUESDAY. OTHERWISE...DRYING
WILL DEVELOP FROM THE SOUTHWEST THROUGH TUESDAY AFTERNOON...WITH
NORTHERN MOUNTAIN UPSLOPE MOISTURE BRIEFLY DRYING UP.
A REINFORCING CLIPPER MAY DIVE INTO THE MEAN EASTERN TROUGH TUESDAY
NIGHT...WITH THE GFS MORE AMPLIFIED THAN THE ECMWF...PRODUCING
MAINLY ADDITIONAL UPSLOPE SNOW SHOWER COVERAGE OVER THE WESTERN
MOUNTAINS. HEIGHTS WILL BUILD EASTWARD FROM THE BROAD WESTERN RIDGE
WEDNESDAY THROUGH THURSDAY...WITH ASSOCIATED WARMING AND DRYING.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...THE 6Z GFS AND LATEST HRRR HAVE TRENDED MUCH
WETTER WITH THIS FAST-MOVING WEAK LOW PRESSURE SYSTEM TODAY. THEY
ARE SUGGESTING THAT THERE MAY BE ENUF MOISTURE AND LLVL SUPPORT FOR
A BAND OF SNOW SHOWERS SOMEWHERE ACROSS THE PIEDMONT. THE HRRR HAS
IT SETTING UP FROM KAND TO SOUTH OF KUZA AND KCLT. STILL HAVE THE
TEMPO FOR KCLT FOR 14-18Z...BUT WENT A LITTLE MORE PESSIMISTIC WITH
RESTRICTIONS DUE TO INCREASED CHANCE FOR A HEAVIER SNOW SHOWER.
STILL THINK ODDS ARE FOR MAINLY VIRGA AND FLURRIES FOR MOST OF THE
AREAS EAST OF THE MOUNTAINS. AT KAVL...STILL EXPECT VCSH FOR SNOW
SHOWERS. CIGS SHOULD BE MAINLY VFR...BUT THE PESSIMISTIC GFS HAS
SOME MVFR CIGS/VSBY DUE TO SNOW. THIS EVENING THRU THE
OVERNIGHT...NW FLOW BEHIND THE DEPARTING LOW WILL RAMP UP...SCOURING
OUT THE LOW CLOUDS AND MOISTURE EAST OF THE MTNS...BUT KEEPING A
CHANCE FOR MVFR OR LOW VFR STRATUS AND PERIODIC SNOW SHOWERS AT KAVL
WITH GUSTY NNW WINDS. WINDS EAST OF THE MTNS WILL FAVOR NE THRU
ABOUT MIDDAY OR EARLY AFTN...THEN SWITCH TO SW FOR THIS AFTN AND
EVENING. THEN SHIFT TO NW LATE EVENING.
OUTLOOK...AN ARCTIC AIR MASS WILL BUILD OVER THE REGION THIS
WEEKEND...WITH UPSLOPE CLOUDS ON THE WEST SIDE OF THE APPALACHIANS.
A SIGNIFICANT WINTER WEATHER SYSTEM IS POSSIBLE EARLY NEXT WEEK.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT HIGH 91% HIGH 90% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 95% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 91% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 98% HIGH 100% HIGH 100% HIGH 100%
KAND MED 78% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WINTER WEATHER ADVISORY UNTIL 6 AM EST SATURDAY FOR NCZ033-
048>052.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST SUNDAY
FOR NCZ033-049-050.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY
FOR NCZ048-051-052-058-059.
SC...NONE.
&&
$$
SYNOPSIS...HG
NEAR TERM...ARK/JAT
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
653 AM EST FRI FEB 12 2016
.SYNOPSIS...
A FAST MOVING UPPER LEVEL DISTURBANCE WILL BRING A BRIEF CHANCE OF
PRECIPITATION TO MUCH OF THE AREA TODAY. A STRONG DOME OF CANADIAN
HIGH PRESSURE WILL SETTLE IN OVER THE WEEKEND...USHERING IN ANOTHER
PERIOD OF COLD TEMPERATURES. THIS WILL BE FOLLOWED BY ANOTHER
WEATHER SYSTEM WHICH WILL PRODUCE A BETTER CHANCE OF PRECIPITATION
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 650 AM...THE MODELS SEEM TO BE LATCHING ONTO MORE MOISTURE OR
BETTER LLVL LIFT EAST OF THE MTNS. THE 6Z GFS AND THE LATEST RAP AND
HRRR NOW HAVE HIGHER POP/MORE COVERAGE OF SNOW SHOWERS ACROSS THE
PIEDMONT. IT LOOKS LIKE A BAND MAY SET UP SOMEWHERE ACROSS THE
UPSTATE. HOWEVER...CONFIDENCE IS STILL LOW. POPS MAY NEED TO BE
ADJUSTED UPWARD IF TRENDS ON RADAR LOOK TO BE LINING UP WITH THE
HRRR. OTHERWISE...FCST LOOKS ON TRACK.
AS OF 315 AM...A VIGOROUS SHORT WAVE CAN BE SEEN ON WATER VAPOR
IMAGERY DIVING INTO THE OHIO VALLEY TOWARD THE BASE OF A LONG WAVE
TROF ALONG THE EAST COAST. THIS WAVE WILL CROSS THE CWFA JUST AFTER
DAYBREAK...AND WILL BE ACCOMPANIED BY A 130 KT 300 MB JET. THIS WILL
RESULT IN STRONG MID AND UPPER LEVEL FORCING FROM ABOUT 12Z TO 18Z
TODAY. AT THE SFC...A WEAK ALBERTA CLIPPER WAS ANALYZED OVER
MO...AND WILL STREAK JUST SOUTH OF THE CWFA DURING THE DAY. LLVL FLOW
IS BACKING OUT OF THE WSW...BUT STRUGGLING TO TAP INTO MUCH MOISTURE.
SO THE FORECAST CHALLENGE FOR TODAY WILL BE HOW MUCH QPF WILL
ACCOMPANY THE SYSTEM...AS THE OP MODELS SHOW SOME SPREAD ON COVERAGE
AND AMOUNTS. THE 00Z NAM KEEPS THE PIEDMONT DRY...WHILE THE
OTHER OP MODELS HAVE SOME LIGHT AMOUNTS. I LIKE THE AGREEMENT OF THE
CAMS ON THE SIMULATED REFLECTIVITY...SHOWING LIGHT PRECIP BREAKING
OUT ACRS THE MTNS RIGHT AROUND DAYBREAK...THEN QUICKLY SPREADING
EAST ACROSS THE PIEDMONT DURING THE LATE MORNING HOURS. BY EARLY
AFTN...THE MODELS SHOW PRECIP CONFINED TO WESTERLY UPSLOPE AREAS
ALONG THE TN BORDER. I THINK MUCH OF WHAT THE CAMS ARE SHOWING WOULD
BE VIRGA...GIVEN THE MOISTURE MAINLY IN THE MID LEVELS. SO POPS SHOW
LIKELY IN THE MTNS...ESP NEAR THE TN BORDER...WHILE ONLY SLIGHT
CHANCE TO LOW-END CHANCE EAST. FCST PROFILES SHOW THAT THIS WOULD BE
A RAIN/SNOW EVENT...WITH WET-BULB EFFECTS ALLOWING FOR LIGHT SNOW
SHOWERS AND/OR FLURRIES JUST ABOUT ANYWHERE THIS MORNING. ACCUMS
THRU THE DAY WILL BE IN THE MTNS...WITH NOTHING MORE THAN A DUSTING
EXPECTED ELSEWHERE. TEMPS SHOULD BE ABOUT 10-15 DEGREES BELOW NORMAL
UNDER MOSTLY CLOUDY SKIES AND SPOTTY PRECIP.
TONIGHT...THE CLIPPER SYSTEM WILL ALREADY BE DEVELOPING A NEW LOW
OUT OVER THE ATLANTIC JUST EAST OF THE OUTER BANKS BY EARLY
EVENING...WHILE A STRONG ARCTIC HIGH (PRESSURE AROUND 1044 MB)
BUILDS IN ACROSS THE PLAINS TO THE SOUTHEAST STATES. THE SFC
PRESSURE GRADIENT NEVER GETS THAT IMPRESSIVE ATOP THE CWFA.
HOWEVER...THE 850 MB FLOW RAMPS UP OUT OF THE NW TO 40-55 KT ACROSS
THE NC MTNS WITH VERY STRONG CAA. THIS WILL RESULT IN A DOWN RIGHT
COLD AND BLUSTERY NIGHT IN THE MTNS...WITH THE ADDITION OF LINGERING
MOISTURE FOR NW FLOW SNOW SHOWERS. IN FACT...THE COLD AIR AND NEAR
PERFECT ORTHOGOTHAL DIRECTION COULD MAKE FOR EFFICIENT SNOW
PRODUCING SHOWERS ALONG THE TN LINE. THE EXPECTED SNOW WITH THE
CLIPPER ALONG WITH THE NW FLOW SNOW SHOULD RESULT IN TOTAL ACCUMS OF
2-4" ACROSS THE USUAL NW FLOW UPSLOPE AREAS. THIS ALONG WITH WINDS
IN THE 25-40 MPH RANGE AND GUSTS IN THE 40-55 MPH RANGE SEEMS TO
WARRANT A WINTER WEATHER ADVISORY. I WILL START IT AT NOON TO
EMCOMPASS THE SNOW ACCUMS EXPECTED TODAY...AND GO THRU 6 AM SATURDAY
(WHEN SNOW SHOWER ACTIVITY WILL TAPER OFF). IN ADDITION...TEMPS WILL
BE PLUMMETING INTO THE TEENS TO SINGLE DIGITS...SO WIND CHILLS WILL
BE IN THE -5 TO -15 F RANGE FOR MOST LOCATIONS ABOVE 3500 FT. A WIND
CHILL ADVISORY WILL BE ISSUED STARTING AT MIDNIGHT...ALTHOUGH SOME
LOCATIONS ABOVE 5000 FT OR SO MAY START SEEING DANGEROUS WIND CHILLS
EARLIER IN THE EVENING. THE REST OF THE CWFA SHOULD SEE CLEARING
SKIES AND LINGERING WINDS WITH CHILLY TEMPS ABOUT 8-15 DEGREES BELOW
NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM EST FRIDAY...A BROAD TROUGH OF LOW PRESSURE WILL EXTEND
SOUTHWARD ACROSS THE EASTERN UNITED STATES SATURDAY FROM A LOW
CENTER OVER SOUTHERN QUEBEC. ISOLATED TO SCATTERED NW FLOW SNOW
SHOWERS COULD LINGER ACROSS THE NORTHERN MOUNTAINS EARLY
SATURDAY...BUT WITH MOISTURE DIMINISHING THROUGH THE DAY. COLD
MORNING TEMPERATURES AND BRISK NW FLOW WILL PERMIT BITTER WIND
CHILLS TO CONTINUE THROUGH SATURDAY MORNING ACROSS THE
MOUNTAINS...AND ON INTO SATURDAY NIGHT/SUNDAY MORNING ACROSS THE
NORTHERN MOUNTAINS. MEANWHILE...VERY COLD AIR WILL DIVE SOUTHEAST
FROM CANADA INTO THE REGION ON THE BACK SIDE OF THE TROUGH AS THE
ASSOCIATED ARCTIC HIGH PRESSURE MOVES ACROSS THE MIDWEST ON SATURDAY
AND REACHES THE EASTERN SEABOARD BY LATE SUNDAY. IN THE COLD
AIRMASS...MAX TEMPERATURES WILL RUN AT LEAST 20 DEGREES BELOW CLIMO
IN MOST AREAS...WHILE SUNDAY MORNING MINS WILL BE 10 TO 20 DEGREES
BELOW CLIMO. A WIND CHILL ADVISORY WILL CONTINUE UNTIL MID SUNDAY
MORNING ACROSS THE NORTHERN NC MOUNTAINS.
THE UPPER FLOW WILL FLATTEN SLIGHTLY OVER THE EAST ON SUNDAY AS A
NORTHERN STREAM SHORTWAVE DIGS INTO THE MIDWEST WHILE A SOUTHERN
STREAM SYSTEM TAKES SHAPE FROM THE FOUR CORNERS REGION TOWARD TX.
THE FIRST HINT OF MID LEVEL UPGLIDE MOISTURE WILL ARRIVE IN THE CWA
FROM THE WEST ON SUNDAY...BUT WITH DRY LOW LEVELS PRECLUDING ANY
PRECIPITATION FROM REACHING THE GROUND THROUGH LATE DAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 300 AM EST FRIDAY...A WINTRY MIXED MAG OF PRECIPITATION IS
LOOKING LIKELY STARTING SUNDAY NIGHT INTO MONDAY GIVEN THE VERY COLD
AND DRY AIRMASS THAT WILL BE PRESENT OVER THE AREA BEFORE ONSET.
THERE IS GOOD MODEL CONSENSUS ON THE ENERGY WITH THE SOUTHERN STREAM
SYSTEM SHARPENING UP RAPIDLY OVER THE LOWER MS RIVER VALLEY SUNDAY
NIGHT INTO MONDAY. MEANWHILE...THE SURFACE HIGH CENTER TO THE NORTH
WILL RETREAT OFFSHORE. LOW LEVEL UPGLIDE MOISTURE WILL FILL IN
RAPIDLY ACROSS OUR AREA EARLY MONDAY...WITH THE 850 MB ZERO ISOTHERM
ALONG THE SOUTHERN FRINGE OF THE AREA AROUND DAYBREAK MOVING RAPIDLY
TOWARD THE NORTHERN FRINGE OF THE FORECAST AREA BY MID AFTERNOON.
EVEN THOUGH COLD AIR DAMMING IS VERY LIKELY...THE COLD AIR MAY ONLY
STAY DEEPLY ENTRENCHED EAST OF THE NORTHERN BLUE RIDGE GIVEN THE
INCREASINGLY OFFSHORE PARENT HIGH LOCATION. STILL...PROFILES ARE
PLENTY COLD FOR PRECIPITATION TO START AS SNOW THROUGHOUT BEFORE
DAYBREAK MONDAY...WITH A BLOSSOMING WARM NOSE THEN INVADING THE
SOUTHERN TIER OF THE FORECAST AREA MONDAY MORNING AND MOVING
NORTHWARD ACROSS THE REGION THROUGH THE DAY.
THE BEST UPPER FORCING ACTUALLY ARRIVES MONDAY NIGHT AS UPPER JET
DIVERGENCE BRIEFLY SETS UP AND DEEP LAYER Q VECTOR FORCING CROSSES
THE REGION AHEAD OF THE INCREASINGLY NEGATIVE TILT UPPER TROUGH.
FORCING AND MOISTURE WILL BE STRONGLY FOCUSED ON THE REGION LATE
MONDAY NIGHT/EARLY TUESDAY WITH THE SURFACE LOW CENTER LIKELY
TRACKING THROUGH THE CENTRAL CAROLINAS...THE CAD GETTING FURTHER
PINCHED OFF TO THE NORTH...AND THE HEAVIEST PRECIPITATION DURING THE
WARMEST PART OF THE EPISODE.
SO...THERE ARE PLENTY OF POTENTIAL HAZARDS. SIGNIFICANT ICE AND SNOW
ACCUMULATIONS WILL BE POSSIBLE...MAINLY OVER WESTERN NC AND
ESPECIALLY ALONG AND NORTH OF INTERSTATE 40. IN ADDITION...HEAVY QPF
COULD CREATE SOME HYDRO ISSUES MONDAY NIGHT INTO TUESDAY MORNING
WITH THE FRONTOGENESIS MAX WEST OF THE PASSING 850 MB LOW LIKELY
LINGERING OVER THE EASTERN SLOPES OF THE MOUNTAIN. THE HEAVY
RAINFALL ON TOP OF ACCUMULATED SNOW AND ICE COULD CREATE SOME LOCAL
ICE DAMMING PROBLEMS ON SHALLOW SLOPED ROOFS. FINALLY...SURFACE
BASED CAPE VALUES OF 200 TO 300 J/KG ARE POSSIBLE TOWARD DAYBREAK
TUESDAY IN THE LOWER PIEDMONT...WITH 850 TO 500 MB LAPSE RATES OF
6.5 TO 7.0 DEG C/KM...ALONG WITH BACKED 50 KT 850 MB FLOW. THIS
COULD CREATE A BRIEF SEVERE THUNDERSTORM THREAT FROM CHESTER TO
MONROE OR THEREABOUTS AROUND DAYBREAK TUESDAY. OTHERWISE...DRYING
WILL DEVELOP FROM THE SOUTHWEST THROUGH TUESDAY AFTERNOON...WITH
NORTHERN MOUNTAIN UPSLOPE MOISTURE BRIEFLY DRYING UP.
A REINFORCING CLIPPER MAY DIVE INTO THE MEAN EASTERN TROUGH TUESDAY
NIGHT...WITH THE GFS MORE AMPLIFIED THAN THE ECMWF...PRODUCING
MAINLY ADDITIONAL UPSLOPE SNOW SHOWER COVERAGE OVER THE WESTERN
MOUNTAINS. HEIGHTS WILL BUILD EASTWARD FROM THE BROAD WESTERN RIDGE
WEDNESDAY THROUGH THURSDAY...WITH ASSOCIATED WARMING AND DRYING.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...THE 6Z GFS AND LATEST HRRR HAVE TRENDED MUCH
WETTER WITH THIS FAST-MOVING WEAK LOW PRESSURE SYSTEM TODAY. THEY
ARE SUGGESTING THAT THERE MAY BE ENUF MOISTURE AND LLVL SUPPORT FOR
A BAND OF SNOW SHOWERS SOMEWHERE ACROSS THE PIEDMONT. THE HRRR HAS
IT SETTING UP FROM KAND TO SOUTH OF KUZA AND KCLT. STILL HAVE THE
TEMPO FOR KCLT FOR 14-18Z...BUT WENT A LITTLE MORE PESSIMISTIC WITH
RESTRICTIONS DUE TO INCREASED CHANCE FOR A HEAVIER SNOW SHOWER.
STILL THINK ODDS ARE FOR MAINLY VIRGA AND FLURRIES FOR MOST OF THE
AREAS EAST OF THE MOUNTAINS. AT KAVL...STILL EXPECT VCSH FOR SNOW
SHOWERS. CIGS SHOULD BE MAINLY VFR...BUT THE PESSIMISTIC GFS HAS
SOME MVFR CIGS/VSBY DUE TO SNOW. THIS EVENING THRU THE
OVERNIGHT...NW FLOW BEHIND THE DEPARTING LOW WILL RAMP UP...SCOURING
OUT THE LOW CLOUDS AND MOISTURE EAST OF THE MTNS...BUT KEEPING A
CHANCE FOR MVFR OR LOW VFR STRATUS AND PERIODIC SNOW SHOWERS AT KAVL
WITH GUSTY NNW WINDS. WINDS EAST OF THE MTNS WILL FAVOR NE THRU
ABOUT MIDDAY OR EARLY AFTN...THEN SWITCH TO SW FOR THIS AFTN AND
EVENING. THEN SHIFT TO NW LATE EVENING.
OUTLOOK...AN ARCTIC AIR MASS WILL BUILD OVER THE REGION THIS
WEEKEND...WITH UPSLOPE CLOUDS ON THE WEST SIDE OF THE APPALACHIANS.
A SIGNIFICANT WINTER WEATHER SYSTEM IS POSSIBLE EARLY NEXT WEEK.
CONFIDENCE TABLE...
12-18Z 18-24Z 00-06Z 06-12Z
KCLT HIGH 95% MED 79% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 94% HIGH 100%
KHKY HIGH 91% HIGH 83% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 86% HIGH 87% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM EST SATURDAY
FOR NCZ033-048>052.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST SUNDAY
FOR NCZ033-049-050.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY
FOR NCZ048-051-052-058-059.
SC...NONE.
&&
$$
SYNOPSIS...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
611 PM CST SAT FEB 13 2016
.UPDATE...
ISSUED AT 557 PM CST SAT FEB 13 2016
UPDATED AVIATION DISCUSSION FOLLOWS. ALSO MADE A COUPLE OF UPDATES
TO THE WEATHER GRIDS TO INTRODUCE THUNDER MENTION TO THE FREEZING
RAIN/SLEET AND SNOW THAT IS CONTINUING TO BE FORECAST ACROSS THE
WINTER WEATHER ADVISORY AREA. CLOUD TO GROUND LIGHTNING HAS BEEN
CONSISTENTLY BEING GENERATED ON THE PVA SIDE OF THIS POTENT UPPER
WAVE OVER THE PAST 6 HOURS...INCLUDING AN UPTICK IN LIGHTNING
ACTIVITY TO OVER 30 CG LIGHTNING STRIKES LAST HOUR. WILL CONTINUE
TO MONITOR TRENDS THIS EVENING TO SEE IF/WHEN ANY FORECAST ZONES
MAY NEED TO BE UPGRADED TO A WARNING FOR HEAVY SNOW. LATEST HRRR
OUTPUT SEEMS TO SUGGEST THIS CWA WILL BE MISSED BY THE MOST
INTENSE CONVECTIVELY-INFLUENCED SNOW OVERNIGHT. STAY TUNED.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 235 PM CST SAT FEB 13 2016
FAIRLY ACTIVE SHORT TERM FORECAST FOR THE AREA AS TWO FEATURES
WILL COMBINE TO PRODUCE MODERATE TO OCCASIONALLY HEAVY SNOWFALL
OVER THE CWA. THE STRONG SHORTWAVE THAT WILL SLIDE SOUTHEAST
ACROSS SOUTHWEST SOUTH DAKOTA IS STILL LOCATED IN CENTRAL MONTANA
AT THIS TIME...AND IS LEADING TO A COUPLE AREAS OF PRECIPITATION
IN EASTERN MONTANA (ONE ALONG THE WARM FRONT AND ANOTHER TIED TO
THE SHORTWAVE AND COLD FRONT). CLOSER TO THE AREA...SEEING
PRECIPITATION JUST TO THE WEST OF THE MISSOURI RIVER THAT IS
SLOWLY MOVING EAST-SOUTHEAST. THIS PRECIPITATION IS DUE TO THE
INITIAL AREA OF MID-LEVEL WARM AIR ADVECTION AHEAD OF THE WARM
FRONT STRETCHING SOUTH-SOUTHEAST THROUGH FAR WESTERN SOUTH DAKOTA.
WEBCAMS SHOW THAT THE PRECIPITATION TOWARDS HAAKON/STANLEY
COUNTIES IS IN THE FORM OF RAIN AND WITH SURFACE TEMPERATURES IN
THAT AREA AROUND OR ABOVE FREEZING...DON/T THINK THERE IS TOO MUCH
FREEZING RAIN OCCURRING AT THIS POINT. FARTHER NORTH...RAP
ANALYSIS SOUNDINGS INDICATE THE WARM NOSE ALOFT WEAKENS WHICH
SHOULD TRANSITION THE PRECIP TO SNOW THE FARTHER NORTH YOU HEAD.
OVER THE REST OF THE AREA...CLOUDS HAVE BEEN LOWERING WITH THE
INCREASING LOW LEVEL MOISTURE AND DEPARTING SURFACE RIDGE.
TEMPERATURES ARE STILL FAIRLY COLD OVER NORTHEAST SD...WHERE 2PM
TEMPERATURES RANGE FROM THE UPPER SINGLE DIGITS AT K8D3 TO 13 AT
KABR AND THEN 17 AT KMBG.
MODELS CONTINUING TO STRUGGLE WITH THE TRACK/EVOLUTION OF THE
SHORTWAVE IN MONTANA...WHICH LEADS TO SOME UNCERTAINTY IN THE
FORECAST SNOWFALL OVER N.C./N.E. SOUTH DAKOTA THIS EVENING INTO
THE OVERNIGHT HOURS. LATEST RUNS OF THE RAP AND 12Z GLOBAL
MODELS HAVE TRENDED THE TRACK OF THE STRONGEST FORCING A LITTLE
FARTHER TO THE SOUTHWEST AND IN SOME CASES ONLY BARELY BRUSHING
SOUTHWESTERN SD. WHILE THAT BEST FORCING SLIDES SOUTHWEST OF
MUCH OF THE AREA...STILL HAVE SOME SUPPORT FROM THE UPPER TROUGH
AND ESPECIALLY FROM THE WARM AIR ADVECTION / ISENTROPIC ASCENT
ALONG AND AHEAD OF THAT TROUGH THROUGH THE EARLY OVERNIGHT
HOURS. FAIRLY STRONG LIFT WITH THE WAA (AND SEEN IN THE 700MB
OMEGA) WITH FAVORABLE 850-500MB Q-VECTOR DIVERGENCE.
THEREFORE...EXPECT TO SEE A FAIRLY QUICK HITTING (4-7HR PERIOD)
AREA OF PRECIPITATION MOVING THROUGH THE AREA...ESPECIALLY THIS
EVENING INTO THE EARLY OVERNIGHT HOURS. MODELS HAVE TRENDED QPF
AMOUNTS TO THE NORTH WITH THE MOST RECENT RUNS...SOME EVEN
SHOWING 12HR QPF AMOUNTS EXCEEDING 0.6IN BETWEEN
MOBRIDGE/ABERDEEN. THAT POTENTIAL (LIKELY SOMEWHAT CONVECTIVELY
DRIVEN WITH 750-500MB LAPSE RATES AROUND 7 C/KM) WILL NEED TO BE
WATCHED THROUGH THE EVENING AND IF IT SETS UP AS SHOWN WITH SOME
OF THE HIGHER RES RUNS...MAY NEED TO UPGRADE A FEW COUNTIES TO
WARNINGS. WITH THAT FARTHER NORTH TREND...EXPECT A LITTLE LESS
IMPACT FOR THE SOUTHWESTERN CWA...BUT STILL THINK THE POTENTIAL
FOR FREEZING RAIN THROUGH THE FIRST PART OF THE EVENING BEFORE
TRANSITIONING TO SNOW FOR A BRIEF PERIOD BEFORE ENDING. THAT
NORTHWARD SHIFT SHOULD KEEP SNOWFALL AMOUNTS BELOW 2 INCHES FROM
PIERRE AND SOUTHWEST (WHERE SOME AREAS WILL STAY MAINLY RAIN).
AS FOR SNOWFALL AMOUNTS OVER THE NORTH CENTRAL AND
NORTHEAST...HAVE A GENERAL 3-6 INCHES WITH SNOW RATIOS
INCREASING FROM AROUND 10-1 AROUND THE MISSOURI RIVER TO THE
12-14 TO 1 RANGE OVER THE NORTHEAST. OVER THE NORTHEAST...A GOOD
PORTION OF THE LIFT IS AT OR ABOVE THE DGZ...WHICH WILL LIKELY
LEAD TO MORE COLUMNS IN THE SNOW PROCESS AND MORE POTENTIAL FOR
COMPACTING (ALONG WITH AGGREGATION AS THE SNOW FALLS THROUGH THE
CLOUD LAYER BELOW THE DGZ). THUS...DIDN/T WANT TO GO MUCH HIGHER
THAN THE PREVIOUSLY MENTIONED VALUES ...ALTHOUGH RATIOS COULD
BRIEFLY INCREASE IF THE FORCING ALIGNS A LITTLE LOWER AND IN THE
DGZ. WITH THE HIGHER QPF AND RATIOS...HAVE NEAR WARNING SNOWFALL
AMOUNTS (5.5-6IN) OVER MCPHERSON/EDMUNDS/BROWN/MARSHALL/DAY
COUNTIES. WITH THE VARIABILITY IN THE MODEL RUNS TODAY...DIDN/T
HAVE ENOUGH CONFIDENCE TO UPGRADE TO A WARNING AT THIS POINT AND
THE EVENING SHIFT WILL NEED TO MONITOR FOR A POSSIBLE UPGRADE. IN
ADDITION...WITH THE SNOW OCCURRING LATE THIS EVENING AND DURING
THE EARLY OVERNIGHT HOURS...THOUGHT THE IMPACTS WOULD BE LOWER
THAN IF IT OCCURRED DURING THE DAY.
ONE OTHER ITEM TO MENTION WILL BE THE GUSTY SOUTH-SOUTHEAST
WINDS INITIALLY THIS EVENING AHEAD OF THE TROUGH (GUSTS TO
25-30MPH). THAT WILL LEAD TO PATCHY/AREAS OF BLOWING SNOW AND
WILL CONTINUE TO MENTION THAT IN THE FORECAST/WSW.
FOR THE REST OF THE PERIOD...THE SNOW WILL DIMINISH FROM WEST TO
EAST LATE TONIGHT AND THROUGH THE DAY ON SUNDAY (LARGELY OVER
THE EASTERN HALF/THIRD OF THE CWA). A BROAD SURFACE TROUGH WILL
BE OVER THE AREA AND LIMIT THE WINDS AND IN TURN ANY BLOWING SNOW
CONCERNS. IN ADDITION...WITH THE WARM AIR OVER THE
AREA BEHIND THE WARM FRONT THAT MOVED THROUGH...HIGHS WILL RISE
INTO THE MID/UPPER 20S OVER THE FAR EAST TO THE LOWER 40S ALONG
AND WEST OF THE MISSOURI RIVER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 235 PM CST SAT FEB 13 2016
LOW TEMP FORECAST FOR SUNDAY NIGHT IS A BIT TRICKY. AREA WILL STILL
BE IN A RELATIVELY MILD AIR MASS WITH 925MB TEMPS AROUND 0C TO +2C
AND A LIGHT WEST TO SOUTHWEST SFC WIND. ALTHOUGH...WILL HAVE TO KEEP
IN MIND THE FRESH COAT OF SNOW THAT WILL BE OVER MUCH OF THE AREA.
THERE WILL BE SOME DEGREE OF CLOUD COVER AS WELL...SO TRYING TO
FIGURE OUT WHICH VARIABLES HAVE THE BIGGEST IMPACT ON TEMPS IS
TRICKY.
WILL THEN BE WATCHING THE NEXT PIECE OF SHORTWAVE ENERGY WHICH WILL
BE DROPPING SOUTHEAST THROUGH THE AREA MONDAY NIGHT. HAVE INCREASED
POPS FOR THIS EVENT AS MODELS ARE IN PRETTY GOOD AGREEMENT ON TIMING
AND PLACEMENT OF QPF. AGAIN...COULD BE DEALING WITH MIXED PRECIP
ISSUES AS THERE WILL BE WARM AIR IN PLACE.
YET ANOTHER WAVE MOVES THROUGH TUESDAY NIGHT BUT IS LOOKING RATHER
WEAK AT THIS POINT. SUPERBLEND GAVE SLIGHT CHANCE POPS AND THIS
LOOKS GOOD FOR THE TIME BEING. ONLY CHANGE HERE WAS TO REMOVE THE
SLIGHT CHANCES THEY INITIAL GAVE ON TUESDAY AND HELD THINGS OFF TO
TUESDAY NIGHT PER MODEL DATA.
TEMPS THROUGHOUT THE PERIOD STAY ON THE MILD SIDE...ESPECIALLY BY
THURSDAY WHEN MODELS TRY TO BRING IN SOME VERY MILD AIR. 925MB TEMPS
AROUND +20C SHOW UP IN THE MODELS OVER SOUTHWEST AND SOUTH CENTRAL
SD. SUPERBLEND TEMPS HAVE READINGS AS WARM AS THE 60S OVER THE
SOUTHWEST CWA ON THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 557 PM CST SAT FEB 13 2016
FLIGHT CATEGORY WILL BE BOUNCING IN AND OUT OF MVFR/IFR RANGE FOR
CIGS AND VISBIES WITH FREEZING RAIN AND SNOW /PERHAPS EVEN SOME
THUNDER TOO/ PROBABLE AT THE KPIR TERMINAL NOW THROUGH MIDNIGHT.
KMBG...KABR AND KATY WILL PROBABLY JUST SEE LIGHT TO MODERATE SNOW
OVERNIGHT INTO SUNDAY MORNING. BREEZY CONDITIONS AT KMBG AND KPIR
WILL SUBSIDE WITHIN THE NEXT SEVERAL HOURS...BUT AT
KABR/KATY...THE BREEZY TO OCCASIONALLY WINDY SOUTHERLY WINDS WILL
PERSIST INTO SUNDAY MORNING BEFORE BACKING DOWN.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR SDZ003-
004-009-015-016-033>036-045-048-051.
WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR SDZ007-008-011-
019>023.
WINTER WEATHER ADVISORY UNTIL 9 AM CST SUNDAY FOR SDZ005-006-010-
017-018-037.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR MNZ039-046.
&&
$$
UPDATE...DORN
SHORT TERM...SRF
LONG TERM...TDK
AVIATION...DORN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
926 PM CST SAT FEB 13 2016
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
FORECAST FOR TONIGHT LOOKS TO BE ON TRACK. FOCUS WAS ON WINTER
WEATHER MOVING IN TOMORROW. UPDATED WSW AND MOVED UP START TIME TO
15Z FOR COUNTIES WEST OF I-65 DUE TO MODELS INDICATING AN EARLIER
ONSET OF PRECIP DESPITE PRETTY DRY LOW LEVELS OVERNIGHT. STILL
SOME UNCERTAINTY OF HOW FAST THE ABOVE FREEZING TEMPS MOVE IN.
SREF PLUMES ARE INDICATED A RATHER QUICK CHANGEOVER TO RAIN ACROSS
THE AREA AND LIMITS SNOW TOTALS. ON THE OTHER HAND THE 00Z NAM HAS
COME IN COLDER THAN PREVIOUS SOLUTIONS AND TRACKS HEAVIER PRECIP
ACROSS THE I-4O CORRIDOR. 00Z NAM ALSO HOLDS SURFACE TEMPS BELOW
FREEZING UNTIL MONDAY MORNING FOR THE NORTHERN PLATEAU. THERE
LOOKS TO BE A WINDOW OF OPPORTUNITY FOR SOME ICE ACCUMULATIONS FOR
THIS AREA. MIDNIGHT SHIFT WILL NEED TO MONITOR THE NORTHERN
PLATEAU FOR POSSIBLE UPGRADE TO A WINTER STORM WARNING.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR CIGS WILL CONTINUE SPREADING OVER AIRPORTS THIS EVENING AND
GRADUALLY LOWER THROUGH THE NIGHT. EXPECTING MAINLY VIRGA WITH
SOME -SHSN AROUND AIRPORTS AS EARLY AS 12-16Z...POSSIBLY EVEN
EARLIER PER HRRR MODEL RUNS...BUT MAIN -SHSN WILL BEGIN IN THE
14-19Z TIMEFRAME AND CONTINUE THROUGH THE END OF THE CURRENT TAF
PERIOD WITH CIGS/VIS LOWERING TO MVFR. LIGHT NORTHEAST WINDS THIS
EVENING WILL VEER TO SOUTHEASTERLY AND INCREASE DURING THE DAY
TOMORROW WITH GUSTS UP TO 20 KTS POSSIBLE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 6 AM CST MONDAY FOR
CLAY-CUMBERLAND-DAVIDSON-DE KALB-FENTRESS-JACKSON-MACON-OVERTON-
PICKETT-PUTNAM-SMITH-SUMNER-TROUSDALE-WHITE-WILSON.
WINTER WEATHER ADVISORY FROM 9 AM SUNDAY TO 6 AM CST MONDAY FOR
CHEATHAM-DICKSON-HOUSTON-HUMPHREYS-MONTGOMERY-ROBERTSON-STEWART.
&&
$$
SHORT TERM/AVIATION........55/SHAMBURGER
LONG TERM..................10/REAGAN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
543 PM CST SAT FEB 13 2016
.UPDATE...
FOR 00Z AVIATION DISCUSSION.
&&
.DISCUSSION...
1040 MBAR SURFACE HIGH CENTERED OVER THE MID WEST THIS AFTERNOON
WILL KEEP COLD AIR WORKING DOWN INTO THE MID STATE TONIGHT INTO
EARLY SUNDAY. STRONG MID AND UPPER JET PATTERN ACROSS THE REGION
WITH ONGOING SPEED MAX PUNCHING DOWN THROUGH SOUTHEAST KANSAS AT
12Z SUNDAY MORNING WILL STRENGTHEN WEST TO EAST ACROSS KENTUCKY
SUNDAY AFTERNOON THROUGH SUNDAY NIGHT. WITH COLD TEMPS ALREADY IN
PLACE AM EXPECTING TO SEE A WINTRY MIX OF SNOW...SLEET AND
FREEZING RAIN MOVING INTO THE MID STATE FROM THE NORTHWEST DURING
THE DAY SUNDAY. I DON`T SEE A LOT OF SURFACE REFLECTION WITH THIS
SYSTEM BUT THERE IS A WEAK SURFACE WAVE THAT DEVELOPS IN THE LOWER
MISSISSIPPI VALLEY SUNDAY NIGHT THAT WILL ACT AS A FOCUS TO
INTENSIFY THE PRECIP HERE IN THE MID STATE. THIS WILL BE A QUICK
HITTING WINTER EVENT BUT FORTUNATELY ENOUGH WARMER TEMPS GET
ADVECTED INTO THE MID STATE AND THE WINTRY PRECIP WILL LIKELY
CHANGE TO ALL RAIN AS WE GO THROUGH SUNDAY EVENING WITH ONE
EXCEPTION BEING THE UPPER CUMBERLAND WHERE IT MAY BE LATE SUNDAY
NIGHT BEFORE A CHANGE OVER OCCURS IN THAT AREA. THIS SHOULD
ALLEVIATE ANY PROBLEMS THAT INITIALLY DEVELOPS ON ROADWAYS RATHER
QUICKLY.
I`VE KEPT POPS IN THE FORECAST THROUGH TUESDAY NIGHT THEN DRY
WEDNESDAY AND THURSDAY WITH RAIN CHANCES RETURNING FRIDAY NIGHT
AND SATURDAY. TEMPS MODERATE AS WE GO THROUGH THE WORK WEEK WITH
HIGHS BY FRIDAY IN THE MIDDLE 60`S.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR CIGS WILL CONTINUE SPREADING OVER AIRPORTS THIS EVENING AND
GRADUALLY LOWER THROUGH THE NIGHT. EXPECTING MAINLY VIRGA WITH
SOME -SHSN AROUND AIRPORTS AS EARLY AS 12-16Z...POSSIBLY EVEN
EARLIER PER HRRR MODEL RUNS...BUT MAIN -SHSN WILL BEGIN IN THE
14-19Z TIMEFRAME AND CONTINUE THROUGH THE END OF THE CURRENT TAF
PERIOD WITH CIGS/VIS LOWERING TO MVFR. LIGHT NORTHEAST WINDS THIS
EVENING WILL VEER TO SOUTHEASTERLY AND INCREASE DURING THE DAY
TOMORROW WITH GUSTS UP TO 20 KTS POSSIBLE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 6 AM CST MONDAY FOR
CHEATHAM-CLAY-CUMBERLAND-DAVIDSON-DE KALB-DICKSON-FENTRESS-
HOUSTON-HUMPHREYS-JACKSON-MACON-MONTGOMERY-OVERTON-PICKETT-
PUTNAM-ROBERTSON-SMITH-STEWART-SUMNER-TROUSDALE-WHITE-WILSON.
&&
$$
SHORT TERM/AVIATION........55/SHAMBURGER
LONG TERM..................10/REAGAN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1201 PM EST FRI FEB 12 2016
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL PASS JUST SOUTH OF THE REGION THIS
AFTERNOON BRINGING PERIODS OF LIGHT SNOW OR SNOW SHOWERS
ESPECIALLY ACROSS THE MOUNTAINS. A SURGE OF ARCTIC AIR FOLLOWS
THIS SYSTEM OVERNIGHT RESULTING IN VERY WINDY CONDITIONS AND
BITTERLY COLD TEMPERATURES...ALONG WITH SOME ADDED SNOW SHOWERS
FOR THE FAR WESTERN SLOPES OF THE APPALACHIANS INTO SATURDAY. BY
MONDAY ANOTHER WINTER STORM SYSTEM WILL BEGIN TO AFFECT THE REGION
WITH THE POTENTIAL FOR SNOW AND MIXED PRECIPITATION THROUGH THE
FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EST FRIDAY...
COLUMN CONTINUING TO SLOWLY MOISTEN AS AXIS OF ISENTROPIC LIFT
SPILLS EAST AHEAD OF THE STRONG UPPER SHORTWAVE SEEN ON WATER
VAPOR PASSING TO THE SOUTH. LATEST SHORT TERM GUIDANCE CONTINUES
TO VARY ON JUST HOW FAR EAST ANY OF THESE BANDS WILL MAKE IT WITH
SOME PRIMARILY CONFINED TO THE WESTERN SLOPES...WHILE OTHERS
INCLUDING THE WRF-ARW AND TO SOME DEGREE THE HRRR SPILL LIGHT
SNOW EAST TO THE BLUE RIDGE AND POINTS EAST. ALTHOUGH THIS LOOKS
OVERDONE...PERIOD OF BACKING ALOFT MAY BE ENOUGH TO HELP PUSH
LIGHT SNOW FARTHER EAST THAN TYPICAL DOWNSLOPING WOULD ALLOW
ESPCLY WITH THE UPSTREAM TRAILING CHANNELED VORT AXIS SEEN BACK
IN KY. THUS BUMPED UP AMOUNTS A BIT ACROSS THE FAR SW PER CURRENT
TRAJECTORY OF SNOW TO THE WEST AND HEADING OUT EAST OF THE BLUE
RIDGE FOR AT LEAST A COATING. APPEARS LEAST AMOUNT OF SNOW MAY
OCCUR OVER THE NORTH AS THE TRANSFER OF ENERGY FROM THE MOUNTAINS
TO THE COASTAL DUCKS FARTHER SOUTH THROUGH THE AFTERNOON. STILL
GOING HEADLINES ON TRACK FOR AN INCH OR SO TODAY OUT WEST AND
COMBINED UPSLOPE OVERNIGHT SO NO CHANGES THERE OTHER THAN TO TWEAK
AMOUNTS. ALSO MADE SOME SLIGHT UPWARD ADJUSTS TO TEMPS MAINLY EAST
WHERE COULD SURGE UP AS A FEW BREAKS DEVELOP AHEAD OF ANY PRECIP
THAT ATTEMPTS TO HEAD EAST OF THE RIDGES. THINK MOST PTYPE EVEN
OUT THERE TO BE SNOW GIVEN COLDNESS ALOFT SO RUNNING WITH MOSTLY
SNOW/SNOW SHOWERS.
WILL NEED TO TAKE A LOOK AT THE WINDS OVERNIGHT INTO SATURDAY
MORNING BEHIND THE PASSING ARCTIC FRONT AS COULD SEE WARNING
CRITERIA SW BUT WILL AWAIT 12Z GUIDANCE BEFORE UPDATING.
PREVIOUS DISCUSSION AS OF 400 AM EST FRIDAY...
THE MAIN WEATHER PLAYERS FOR OUR REGION TODAY AND TONIGHT WILL BE AN
UPPER LEVEL SHORT WAVE BRINGING SOME LIGHT SNOW TO THE FAR WESTERN
PORTION OF THE AREA BEFORE A STRONG COLD FRONT MOVES THROUGH AND SETS
OFF ANOTHER ROUND OF UPSLOPE SNOW SHOWERS WEST OF THE BLUE RIDGE.
BELIEVE THE MOUNTAIN EMPIRE REGION WILL SEE AN INCH OR LESS OF SNOW
BEFORE THE UPSLOPE REALLY KICKS IN AND PROVIDES ADDITIONAL ACCUMULATIONS
ALONG THE FAR WESTERN SLOPES THROUGH TONIGHT. THE AIR MOVING IN BEHIND
THE FRONT IS QUITE COLD INDEED AND WILL CREATE SOME VERY STEEP LOW LEVEL
LAPSE RATES AND EVEN A BIT OF CAPE...WHICH MAY BRING US ANOTHER CHANCE
FOR A PERIOD OF THUNDERSNOW EARLY TONIGHT. MESO MODELS ALSO INDICATE
A DECENT UPSTREAM CONTRIBUTION TO THE MOISTURE FROM THE GREAT LAKES.
BELIEVE THESE FACTORS WILL COMBINE TO GENERATE SNOW ACCUMULATIONS
GENERALLY IN THE 2 TO 4 INCH RANGE FOR THE WESTERN SLOPES WITH SOME
LOCALLY HIGHER AMOUNTS POSSIBLE SO WILL ISSUE AN ADVISORY FOR THIS AREA
FROM THIS AFTERNOON THROUGH TONIGHT.
LOW LEVEL WINDS WILL ALSO START TO INCREASE TONIGHT AND GOOD MOMENTUM
TRANSFER IN THE BOUNDARY LAYER WILL ALLOW FOR QUITE A BIT OF WIND
OVERNIGHT WITH GUSTS OVER 40 MPH EXPECTED ESPECIALLY OVER THE HIGHER
TERRAIN. THIS WILL COMBINE WITH TEMPERATURES WEST OF THE BLUE RIDGE
FALLING INTO THE SINGLE DIGITS TO GENERATE WIND CHILL VALUES OF 5 TO 15
BELOW ZERO...WITH READINGS TO 25 BELOW FOR WESTERN GREENBRIER COUNTY IN
WEST VIRGINIA. WINDS WILL GRADUALLY SUBSIDE ON SATURDAY BUT THE
COMBINATION OF WIND AND VERY COLD TEMPERATURES WILL CONTINUE TO
GENERATE VERY LOW WIND CHILL VALUES THROUGH SUNDAY MORNING. A WIND
CHILL ADVISORY WILL BE ISSUED FOR THE AREA ALONG AND WEST OF THE BLUE
RIDGE FROM TONIGHT THROUGH SUNDAY MORNING WITH A WIND CHILL WARNING FOR
WESTERN GREENBRIER. CONDITIONS EAST OF THE RIDGE WILL NOT BE QUITE AS
SEVERE AS LOWS TONIGHT REACH THE 15 TO 20 DEGREE RANGE WITH WIND CHILL
VALUES INTO THE SINGLE DIGITS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 430 AM EST FRIDAY...
COLDEST AIR OF THE SEASON STILL SLATED TO BE SPREADING INTO THE
REGION FOR SATURDAY...WITH TEMPERATURES BOTTOMING OUT SUNDAY
MORNING. THE MODELS HAVE BACKED OFF THE INTENSITY OF THE COLD AIR
MASS JUST SLIGHTLY WITH EACH SUCCEEDING RUN...NOW STOPPING AROUND
-22C ACROSS THE FAR NORTHERN PORTION OF THE CWA. SIMILAR EVENTS
THE PAST TWO YEARS HAVE SEEN READINGS CLOSER TO -25/-26C...SO FEEL
CONFIDENT THAT MORNING LOW TEMPERATURES SUNDAY MORNING WILL FALL A
COUPLE OF DEGREES SHY OF WHAT WE SAW THE LAST COUPLE OF YEARS WITH
SIMILAR ARCTIC OUTBREAKS. ALSO...SNOW COVER IS LIMITED EAST OF
THE ALLEGHANY FRONT AND THE MOUNTAINS OF SW VA/NW NC...SO THAT
WILL ALSO NOT HELP DRIVE TEMPERATURES TO THE LEVELS WE SAW AROUND
THIS TIME LAST YEAR. NONETHELESS...IT WILL BE BITTERLY COLD AND
VERY WINDY...PROMPTING A CONTINUATION OF THE WIND CHILL ADVISORIES
WEST OF THE BLUE RIDGE AND THE WARNING FOR WESTERN GREENBRIER.
WINDS WILL BEGIN TO DIMINISH LATE IN THE DAY AND SATURDAY
NIGHT...BUT WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS AND
NEAR 0 TO -5F AT THE HIGHER ELEVATIONS...THE ADVISORIES/WARNINGS
ARE WARRANTED TO CONTINUE INTO SUNDAY MORNING AS IT WILL TAKE VERY
LITTLE FOR WIND CHILLS TO MEET CRITERIA WITH TEMPS THAT LOW.
UPSLOPE SNOW SHOWERS SHOULD BE WINDING DOWN SATURDAY MORNING
FAIRLY QUICKLY AS THE VERY DRY ARCTIC AIR MASS SPREADS INTO THE
REGION. WILL KEEP SLIGHT CHANCE TO LOW CHANCE POPS FOR SNOW
SHOWERS GOING THROUGH MID-DAY...THEN END THEM...ALBEIT SOME
FLURRIES COULD CONTINUE INTO THE AFTERNOON AS ARCTIC COLD-
ADVECTION SQUEAKS OUT ANY REMAINING MOISTURE. WINDS WILL BE
STRONG AND GUSTY THROUGHOUT THE DAY...BUT LIKELY DROP BELOW
ADVISORY CRITERIA IN THE WEST DURING THE AFTERNOON...ALTHOUGH THAT
IS LUMPED INTO THE WSW.
THE ARCTIC HIGH SETTLES OVER THE REGION SUNDAY MORNING WITH...AS
NOTED ABOVE...BITTERLY COLD TEMPERATURES...BUT WINDS TRENDING
TOWARD CALM. BY AFTERNOON...THE ARCTIC HIGH HAS ALREADY SHIFTED
TOWARD THE VA/MD COAST WITH RETURN FLOW EVIDENT ESPECIALLY IN
SOUTHWEST VA. A NORTHERN STREAM SHORT WAVE QUICKLY MOVES TOWARD
THE REGION BY SUNDAY AFTERNOON...WITH INCREASING MOISTURE FROM TOP
DOWN. THE ANTECEDENT AIR MASS WILL CLEARLY BE VERY DRY AND COLD
AND NOT SURE HOW QUICKLY THE AIR MASS WILL SATURATE TO ALLOW
GENERATED PRECIPITATION ALOFT TO REACH THE GROUND. INDICATIONS ARE
THAT THIS SHOULD BEGIN TO TAKE PLACE AFTER SUNSET IN THE WEST AND
CLOSER TO MIDNIGHT IN THE EAST. THUS...WILL LEAVE THE DAYTIME
HOURS OF SUNDAY DRY WITH POPS BELOW 15 PERCENT. ALL PRECIPITATION
SUNDAY NIGHT WILL BE SNOW ACROSS THE ENTIRE CWA AS THE SOUNDINGS
REMAIN BELOW FREEZING AT ALL LEVELS.
AS WE MOVE INTO MONDAY...THE SITUATION BECOMES INCREASINGLY
COMPLICATED. THE NORTHERN STREAM SHORT WAVE WILL MOVE NORTHEAST OF
THE REGION EARLY MONDAY...WHILE A STRONGER SOUTHERN STREAM SHORT
WAVE DEEPENS INTO THE MID-SOUTH. DEEP SURFACE LOW PRESSURE WILL
THEN DEVELOP IN RESPONSE TO THIS SECOND SOUTHERN STREAM SHORT WAVE
ACROSS THE MID-SOUTH...MOVING TOWARD THE EASTERN TN VALLEY BY
MONDAY EVENING. ALL OF THE MODELS HAVE TAKEN A SLIGHT WEST JOG
WITH THE SURFACE LOW PRESSURE...RESULTING IN THE POTENTIAL FOR
WARMER AIR FROM THE SOUTH AND SOUTHEAST TO ENCROACH ON THE REGION.
NONETHELESS...THE ANTECEDENT AIR MASS WILL BE VERY COLD AND MODELS
OFTEN ADVERTISE A WARMUP TOO QUICKLY WITH THIS TYPE OF SITUATION.
A WARM FRONT WILL LIE ACROSS THE REGION MONDAY NIGHT...THEN BEGIN
TO LIFT NORTHWARD EARLY TUE. THIS IS WHEN THE P-TYPE ISSUES WILL
BEGIN WITH A TRANSITION FROM SNOW TO SLEET TO FREEZING RAIN AND
PERHAPS EVEN RAIN IN PARTS OF THE PIEDMONT. THIS ENTIRE PERIOD
WILL EVENTUALLY HAVE TO BE HANDLED BY TOP-DOWN OR SIMILAR P-TYPE
PROCEDURES...BUT GIVEN IT IS STILL OUT IN THE DAY 4 AND BEYOND
PERIOD....WILL STICK WITH A RAIN/SNOW MIXTURE FOR NOW. ALTHOUGH
SNOW/SLEET/ICE AMOUNTS STILL HIGHLY IN QUESTION...IT STILL APPEARS
QUITE CERTAIN THAT WINTER STORM CRITERIA WILL LIKELY BE MET ACROSS
MUCH OF THE CWA IN THE SUN NIGHT THROUGH EARLY TUE TIME
FRAME...WITH STILL THE POTENTIAL FOR SIGNIFICANT SNOWFALL
ACCUMULATIONS IN THE WESTERN MOUNTAINS. THUS...WILL CONTINUE TO
HIGHLIGHT THIS POTENTIAL IN THE HWO. A WINTER STORM WATCH FOR THIS
PERIOD WILL LIKELY NEED TO FOLLOW ON THE HEELS OF THE CURRENT
WINTER WEATHER ADVISORIES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 100 PM EST THURSDAY...
A DEEPENING SURFACE LOW...REMAINING MOSTLY INLAND...WILL TRACK
ACROSS THE CWA TUE...MOVING TOWARD THE NORTHERN MID-ATLANTIC BY
EVENING. SIGNIFICANT WINTER WEATHER WILL LIKELY CONTINUE FOR MUCH
OF THE CWA...BUT POTENTIALLY TRANSITIONING TO RAIN ACROSS THE
PIEDMONT. BUFKIT SHOWS CONSIDERABLE VERTICAL MOTION IN THE SNOW
GROWTH ZONE EARLY TUESDAY...SO THERE COULD BE A BURST OF HEAVY
SNOW/SLEET BEFORE THE DRY SLOT SPREADS INTO THE REGION FROM THE
SOUTHWEST AND SHUTS OFF THE HEAVIER PRECIPITATION...WHICH SHOULD
OCCUR BY MIDDAY TUE. BY EVENING...COLDER AIR BEGINS TO FILTER
BACK INTO THE WESTERN AREAS AND UPSLOPE SNOW SHOWERS COMMENCE ONCE
AGAIN.
IN THE WAKE OF THE STRONG SYNOPTIC SYSTEM TUESDAY...ANOTHER
CLIPPER IS EVIDENT IN CONTINUED NORTHWEST FLOW ALOFT. OVERALL
WARMING OF ANY SIGNIFICANCE LOOKS LIMITED DURING THIS PERIOD.
ALTHOUGH PREVIOUS RUNS OF THE GFS SHOWED SUBSTANTIAL WARMING
DURING THIS TIME FRAME...THAT IS NOT EVIDENT TODAY. MEXMOS KEEPS
WESTERN AREAS MOSTLY AT OR BELOW FREEZING THROUGH MIDWEEK...WITH
ONLY LIMITED WARMING DURING THE LATER HALF OF THE WEEK. THE
CLIPPER TUE NIGHT/WED...COULD BRING ADDITIONAL MINOR SNOW
ACCUMULATIONS TO THE WESTERN PARTS OF THE CWA BEFORE MOVING
NORTHEAST OF THE REGION. OUTSIDE OF UPSLOPE SNOW SHOWERS...THAT
SHOULD BE THE LAST OF ANY SYNOPTIC-SCALE INDUCED PRECIPITATION FOR
THIS PERIOD.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1150 AM EST FRIDAY...
LOWER CIGS AND ASSOCIATED LIGHT SNOW BANDS WILL CONTINUE TO HEAD
EAST CROSSING THE BLUE RIDGE BY EARLY AFTERNOON. THIS WILL RESULT
IN PERIODS OF MVFR/IFR OVER THE WESTERN SITES AND BRIEF MVFR
ESPCLY AROUND KDAN BY MID AFTERNOON. ONCE THE WINDS TURN MORE
NORTHWEST SHOULD SEE CONDITIONS IMPROVE OVER THE EAST AND RETURN
TO VFR BY EARLY EVENING IF NOT SOONER.
HOWEVER FOR KBCB/KBLF/KLWB THE NWLY WINDS WILL BE UPSLOPE AND
THIS WILL KEEP SNOW SHOWERS AT THESE LOCATIONS WITH MVFR/IFR
CIGS/VSBYS INTO THIS EVENING AT KBCB...CONTINUING OVERNIGHT AT
KBLF/KLWB. BEHIND THE FRONT ALL SITES WILL SEE SIGNIFICANT WIND
GUSTS AS A WELL MIXED BOUNDARY LAYER ALLOWS FOR EFFICIENT MOMENTUM
TRANSFER OF INCREASING LOW LEVEL FLOW. EXPECT G40-45KT AT KROA
WITH GUSTS AOA 35KT FOR KBCB/KBLF OVERNIGHT.
A GRADUAL RETURN TO VFR APPEARS LIKELY ON SATURDAY ALTHOUGH
KBLF/KLWB LIKELY TO KEEP MVFR IN SNOW SHOWERS AROUND UNTIL LATE IN
THE DAY. WINDS WILL REMAIN STRONG ON SATURDAY WITH GUSTS TO 30-40
KTS LIKELY UNTIL HIGH PRESSURE BUILDS IN DURING THE AFTERNOON.
EXTENDED DISCUSSION...
THE NEXT LOW PRESSURE SYSTEM WILL ARRIVE ON SUNDAY NIGHT.
CONFIDENCE IS HIGH THAT POOR FLYING WEATHER WILL TAKE PLACE DURING
MONDAY AND TUESDAY. THIS SYSTEM WILL LIKELY BRING WINTRY
PRECIPITATION TO MUCH OF THE AREA...BUT FURTHER UPDATES FROM THE
LONGER RANGE MODELS MAY IMPACT THE DETAILS ON PRECIPITATION TYPE
AND STORM TRACK. ANOTHER WEAK CLIPPER AREA OF LOW PRESSURE MAY
KEEP MVFR CONDITIONS ACROSS THE MOUNTAINS TUESDAY NIGHT INTO
WEDNESDAY WITH MAINLY VFR EAST OF THE BLUE RIDGE.
&&
.CLIMATE...
COLDEST AIR OF THE SEASON ARRIVES THIS WEEKEND. SEVERAL RECORD LOW
MAX TEMPERATURES AND LOW TEMPERATURES ARE POSSIBLE. BELOW ARE THE
CURRENT RECORDS FOR SATURDAY 2/13 AND SUNDAY 2/14.
SATURDAY 02/13/2016
SITE MINT YEAR LOMAX YEAR
KBLF 4 1988 19 1988
KDAN 11 1955 32 1981
KLYH 5 1979 9 1899
KROA 8 1917 18 1914
KRNK -4 1969 14 1955
SUNDAY 02/14/2016
SITE MINT YEAR LOMAX YEAR
KBLF 5 1971 16 1960
KDAN 15 1986 32 1986
KLYH 4 1899 24 1905
KROA 10 1943 26 1986
KRNK -2 1969 24 1986
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
SUNDAY FOR VAZ007-009>020-022>024-032>035.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR VAZ007-009-
015.
NC...WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
SUNDAY FOR NCZ001-002-018.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR NCZ001-018.
WV...WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
SUNDAY FOR WVZ042>044-507.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR WVZ042-043-
508.
WIND CHILL WARNING FROM 11 PM THIS EVENING TO 10 AM EST SUNDAY
FOR WVZ508.
&&
$$
SYNOPSIS...JH/MBS
NEAR TERM...JH/MBS
SHORT TERM...RAB
LONG TERM...AMS/RAB
AVIATION...JH/MBS/WP
CLIMATE...CF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1006 AM EST FRI FEB 12 2016
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL PASS JUST SOUTH OF THE REGION THIS
AFTERNOON BRINGING PERIODS OF LIGHT SNOW OR SNOW SHOWERS
ESPECIALLY ACROSS THE MOUNTAINS. A SURGE OF ARCTIC AIR FOLLOWS
THIS SYSTEM OVERNIGHT RESULTING IN VERY WINDY CONDITIONS AND
BITTERLY COLD TEMPERATURES...ALONG WITH SOME ADDED SNOW SHOWERS
FOR THE FAR WESTERN SLOPES OF THE APPALACHIANS INTO SATURDAY. BY
MONDAY ANOTHER WINTER STORM SYSTEM WILL BEGIN TO AFFECT THE REGION
WITH THE POTENTIAL FOR SNOW AND MIXED PRECIPITATION THROUGH THE
FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EST FRIDAY...
COLUMN CONTINUING TO SLOWLY MOISTEN AS AXIS OF ISENTROPIC LIFT
SPILLS EAST AHEAD OF THE STRONG UPPER SHORTWAVE SEEN ON WATER
VAPOR PASSING TO THE SOUTH. LATEST SHORT TERM GUIDANCE CONTINUES
TO VARY ON JUST HOW FAR EAST ANY OF THESE BANDS WILL MAKE IT WITH
SOME PRIMARILY CONFINED TO THE WESTERN SLOPES...WHILE OTHERS
INCLUDING THE WRF-ARW AND TO SOME DEGREE THE HRRR SPILL LIGHT
SNOW EAST TO THE BLUE RIDGE. ALTHOUGH THIS LOOKS
OVERDONE...PERIOD OF BACKING ALOFT MAY BE ENOUGH TO HELP PUSH
LIGHT SNOW FARTHER EAST THAN TYPICAL DOWNSLOPING WOULD ALLOW
ESPCLY WITH THE UPSTREAM TRAILING CHANNELED VORT AXIS SEEN BACK
IN KY. THUS BUMPED UP AMOUNTS A BIT ACROSS THE FAR SW PER CURRENT
TRAJECTORY OF SNOW TO THE WEST AND HEADING OUT TO THE BLUE RIDGE
FOR AT LEAST A COATING. APPEARS LEAST AMOUNT OF SNOW MAY OCCUR
OVER THE NORTH AS THE TRANSFER OF ENERGY FROM THE MOUNTAINS TO THE
COASTAL DUCKS FARTHER SOUTH THROUGH THE AFTERNOON. STILL GOING
HEADLINES ON TRACK FOR AN INCH OR SO TODAY OUT WEST AND COMBINED
UPSLOPE OVERNIGHT SO NO CHANGES THERE OTHER THAN TO TWEAK AMOUNTS.
ALSO MADE SOME SLIGHT UPWARD ADJUSTS TO TEMPS MAINLY EAST WHERE
COULD SURGE UP AS A FEW BREAKS DEVELOP AHEAD OF ANY PRECIP THAT
ATTEMPTS TO HEAD EAST OF THE RIDGES. THINK MOST PTYPE EVEN OUT
THERE TO BE SNOW GIVEN COLDNESS ALOFT SO RUNNING WITH MOSTLY
SNOW/SNOW SHOWERS.
WILL NEED TO TAKE A LOOK AT THE WINDS OVERNIGHT INTO SATURDAY
MORNING BEHIND THE PASSING ARCTIC FRONT AS COULD SEE WARNING
CRITERIA SW BUT WILL AWAIT 12Z GUIDANCE BEFORE UPDATING.
PREVIOUS DISCUSSION AS OF 400 AM EST FRIDAY...
THE MAIN WEATHER PLAYERS FOR OUR REGION TODAY AND TONIGHT WILL BE AN
UPPER LEVEL SHORT WAVE BRINGING SOME LIGHT SNOW TO THE FAR WESTERN
PORTION OF THE AREA BEFORE A STRONG COLD FRONT MOVES THROUGH AND SETS
OFF ANOTHER ROUND OF UPSLOPE SNOW SHOWERS WEST OF THE BLUE RIDGE.
BELIEVE THE MOUNTAIN EMPIRE REGION WILL SEE AN INCH OR LESS OF SNOW
BEFORE THE UPSLOPE REALLY KICKS IN AND PROVIDES ADDITIONAL ACCUMULATIONS
ALONG THE FAR WESTERN SLOPES THROUGH TONIGHT. THE AIR MOVING IN BEHIND
THE FRONT IS QUITE COLD INDEED AND WILL CREATE SOME VERY STEEP LOW LEVEL
LAPSE RATES AND EVEN A BIT OF CAPE...WHICH MAY BRING US ANOTHER CHANCE
FOR A PERIOD OF THUNDERSNOW EARLY TONIGHT. MESO MODELS ALSO INDICATE
A DECENT UPSTREAM CONTRIBUTION TO THE MOISTURE FROM THE GREAT LAKES.
BELIEVE THESE FACTORS WILL COMBINE TO GENERATE SNOW ACCUMULATIONS
GENERALLY IN THE 2 TO 4 INCH RANGE FOR THE WESTERN SLOPES WITH SOME
LOCALLY HIGHER AMOUNTS POSSIBLE SO WILL ISSUE AN ADVISORY FOR THIS AREA
FROM THIS AFTERNOON THROUGH TONIGHT.
LOW LEVEL WINDS WILL ALSO START TO INCREASE TONIGHT AND GOOD MOMENTUM
TRANSFER IN THE BOUNDARY LAYER WILL ALLOW FOR QUITE A BIT OF WIND
OVERNIGHT WITH GUSTS OVER 40 MPH EXPECTED ESPECIALLY OVER THE HIGHER
TERRAIN. THIS WILL COMBINE WITH TEMPERATURES WEST OF THE BLUE RIDGE
FALLING INTO THE SINGLE DIGITS TO GENERATE WIND CHILL VALUES OF 5 TO 15
BELOW ZERO...WITH READINGS TO 25 BELOW FOR WESTERN GREENBRIER COUNTY IN
WEST VIRGINIA. WINDS WILL GRADUALLY SUBSIDE ON SATURDAY BUT THE
COMBINATION OF WIND AND VERY COLD TEMPERATURES WILL CONTINUE TO
GENERATE VERY LOW WIND CHILL VALUES THROUGH SUNDAY MORNING. A WIND
CHILL ADVISORY WILL BE ISSUED FOR THE AREA ALONG AND WEST OF THE BLUE
RIDGE FROM TONIGHT THROUGH SUNDAY MORNING WITH A WIND CHILL WARNING FOR
WESTERN GREENBRIER. CONDITIONS EAST OF THE RIDGE WILL NOT BE QUITE AS
SEVERE AS LOWS TONIGHT REACH THE 15 TO 20 DEGREE RANGE WITH WIND CHILL
VALUES INTO THE SINGLE DIGITS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 430 AM EST FRIDAY...
COLDEST AIR OF THE SEASON STILL SLATED TO BE SPREADING INTO THE
REGION FOR SATURDAY...WITH TEMPERATURES BOTTOMING OUT SUNDAY
MORNING. THE MODELS HAVE BACKED OFF THE INTENSITY OF THE COLD AIR
MASS JUST SLIGHTLY WITH EACH SUCCEEDING RUN...NOW STOPPING AROUND
-22C ACROSS THE FAR NORTHERN PORTION OF THE CWA. SIMILAR EVENTS
THE PAST TWO YEARS HAVE SEEN READINGS CLOSER TO -25/-26C...SO FEEL
CONFIDENT THAT MORNING LOW TEMPERATURES SUNDAY MORNING WILL FALL A
COUPLE OF DEGREES SHY OF WHAT WE SAW THE LAST COUPLE OF YEARS WITH
SIMILAR ARCTIC OUTBREAKS. ALSO...SNOW COVER IS LIMITED EAST OF
THE ALLEGHANY FRONT AND THE MOUNTAINS OF SW VA/NW NC...SO THAT
WILL ALSO NOT HELP DRIVE TEMPERATURES TO THE LEVELS WE SAW AROUND
THIS TIME LAST YEAR. NONETHELESS...IT WILL BE BITTERLY COLD AND
VERY WINDY...PROMPTING A CONTINUATION OF THE WIND CHILL ADVISORIES
WEST OF THE BLUE RIDGE AND THE WARNING FOR WESTERN GREENBRIER.
WINDS WILL BEGIN TO DIMINISH LATE IN THE DAY AND SATURDAY
NIGHT...BUT WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS AND
NEAR 0 TO -5F AT THE HIGHER ELEVATIONS...THE ADVISORIES/WARNINGS
ARE WARRANTED TO CONTINUE INTO SUNDAY MORNING AS IT WILL TAKE VERY
LITTLE FOR WIND CHILLS TO MEET CRITERIA WITH TEMPS THAT LOW.
UPSLOPE SNOW SHOWERS SHOULD BE WINDING DOWN SATURDAY MORNING
FAIRLY QUICKLY AS THE VERY DRY ARCTIC AIR MASS SPREADS INTO THE
REGION. WILL KEEP SLIGHT CHANCE TO LOW CHANCE POPS FOR SNOW
SHOWERS GOING THROUGH MID-DAY...THEN END THEM...ALBEIT SOME
FLURRIES COULD CONTINUE INTO THE AFTERNOON AS ARCTIC COLD-
ADVECTION SQUEAKS OUT ANY REMAINING MOISTURE. WINDS WILL BE
STRONG AND GUSTY THROUGHOUT THE DAY...BUT LIKELY DROP BELOW
ADVISORY CRITERIA IN THE WEST DURING THE AFTERNOON...ALTHOUGH THAT
IS LUMPED INTO THE WSW.
THE ARCTIC HIGH SETTLES OVER THE REGION SUNDAY MORNING WITH...AS
NOTED ABOVE...BITTERLY COLD TEMPERATURES...BUT WINDS TRENDING
TOWARD CALM. BY AFTERNOON...THE ARCTIC HIGH HAS ALREADY SHIFTED
TOWARD THE VA/MD COAST WITH RETURN FLOW EVIDENT ESPECIALLY IN
SOUTHWEST VA. A NORTHERN STREAM SHORT WAVE QUICKLY MOVES TOWARD
THE REGION BY SUNDAY AFTERNOON...WITH INCREASING MOISTURE FROM TOP
DOWN. THE ANTECEDENT AIR MASS WILL CLEARLY BE VERY DRY AND COLD
AND NOT SURE HOW QUICKLY THE AIR MASS WILL SATURATE TO ALLOW
GENERATED PRECIPITATION ALOFT TO REACH THE GROUND. INDICATIONS ARE
THAT THIS SHOULD BEGIN TO TAKE PLACE AFTER SUNSET IN THE WEST AND
CLOSER TO MIDNIGHT IN THE EAST. THUS...WILL LEAVE THE DAYTIME
HOURS OF SUNDAY DRY WITH POPS BELOW 15 PERCENT. ALL PRECIPITATION
SUNDAY NIGHT WILL BE SNOW ACROSS THE ENTIRE CWA AS THE SOUNDINGS
REMAIN BELOW FREEZING AT ALL LEVELS.
AS WE MOVE INTO MONDAY...THE SITUATION BECOMES INCREASINGLY
COMPLICATED. THE NORTHERN STREAM SHORT WAVE WILL MOVE NORTHEAST OF
THE REGION EARLY MONDAY...WHILE A STRONGER SOUTHERN STREAM SHORT
WAVE DEEPENS INTO THE MID-SOUTH. DEEP SURFACE LOW PRESSURE WILL
THEN DEVELOP IN RESPONSE TO THIS SECOND SOUTHERN STREAM SHORT WAVE
ACROSS THE MID-SOUTH...MOVING TOWARD THE EASTERN TN VALLEY BY
MONDAY EVENING. ALL OF THE MODELS HAVE TAKEN A SLIGHT WEST JOG
WITH THE SURFACE LOW PRESSURE...RESULTING IN THE POTENTIAL FOR
WARMER AIR FROM THE SOUTH AND SOUTHEAST TO ENCROACH ON THE REGION.
NONETHELESS...THE ANTECEDENT AIR MASS WILL BE VERY COLD AND MODELS
OFTEN ADVERTISE A WARMUP TOO QUICKLY WITH THIS TYPE OF SITUATION.
A WARM FRONT WILL LIE ACROSS THE REGION MONDAY NIGHT...THEN BEGIN
TO LIFT NORTHWARD EARLY TUE. THIS IS WHEN THE P-TYPE ISSUES WILL
BEGIN WITH A TRANSITION FROM SNOW TO SLEET TO FREEZING RAIN AND
PERHAPS EVEN RAIN IN PARTS OF THE PIEDMONT. THIS ENTIRE PERIOD
WILL EVENTUALLY HAVE TO BE HANDLED BY TOP-DOWN OR SIMILAR P-TYPE
PROCEDURES...BUT GIVEN IT IS STILL OUT IN THE DAY 4 AND BEYOND
PERIOD....WILL STICK WITH A RAIN/SNOW MIXTURE FOR NOW. ALTHOUGH
SNOW/SLEET/ICE AMOUNTS STILL HIGHLY IN QUESTION...IT STILL APPEARS
QUITE CERTAIN THAT WINTER STORM CRITERIA WILL LIKELY BE MET ACROSS
MUCH OF THE CWA IN THE SUN NIGHT THROUGH EARLY TUE TIME
FRAME...WITH STILL THE POTENTIAL FOR SIGNIFICANT SNOWFALL
ACCUMULATIONS IN THE WESTERN MOUNTAINS. THUS...WILL CONTINUE TO
HIGHLIGHT THIS POTENTIAL IN THE HWO. A WINTER STORM WATCH FOR THIS
PERIOD WILL LIKELY NEED TO FOLLOW ON THE HEELS OF THE CURRENT
WINTER WEATHER ADVISORIES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 100 PM EST THURSDAY...
A DEEPENING SURFACE LOW...REMAINING MOSTLY INLAND...WILL TRACK
ACROSS THE CWA TUE...MOVING TOWARD THE NORTHERN MID-ATLANTIC BY
EVENING. SIGNIFICANT WINTER WEATHER WILL LIKELY CONTINUE FOR MUCH
OF THE CWA...BUT POTENTIALLY TRANSITIONING TO RAIN ACROSS THE
PIEDMONT. BUFKIT SHOWS CONSIDERABLE VERTICAL MOTION IN THE SNOW
GROWTH ZONE EARLY TUESDAY...SO THERE COULD BE A BURST OF HEAVY
SNOW/SLEET BEFORE THE DRY SLOT SPREADS INTO THE REGION FROM THE
SOUTHWEST AND SHUTS OFF THE HEAVIER PRECIPITATION...WHICH SHOULD
OCCUR BY MIDDAY TUE. BY EVENING...COLDER AIR BEGINS TO FILTER
BACK INTO THE WESTERN AREAS AND UPSLOPE SNOW SHOWERS COMMENCE ONCE
AGAIN.
IN THE WAKE OF THE STRONG SYNOPTIC SYSTEM TUESDAY...ANOTHER
CLIPPER IS EVIDENT IN CONTINUED NORTHWEST FLOW ALOFT. OVERALL
WARMING OF ANY SIGNIFICANCE LOOKS LIMITED DURING THIS PERIOD.
ALTHOUGH PREVIOUS RUNS OF THE GFS SHOWED SUBSTANTIAL WARMING
DURING THIS TIME FRAME...THAT IS NOT EVIDENT TODAY. MEXMOS KEEPS
WESTERN AREAS MOSTLY AT OR BELOW FREEZING THROUGH MIDWEEK...WITH
ONLY LIMITED WARMING DURING THE LATER HALF OF THE WEEK. THE
CLIPPER TUE NIGHT/WED...COULD BRING ADDITIONAL MINOR SNOW
ACCUMULATIONS TO THE WESTERN PARTS OF THE CWA BEFORE MOVING
NORTHEAST OF THE REGION. OUTSIDE OF UPSLOPE SNOW SHOWERS...THAT
SHOULD BE THE LAST OF ANY SYNOPTIC-SCALE INDUCED PRECIPITATION FOR
THIS PERIOD.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AS OF 630 AM EST FRIDAY...
DEVELOPING COASTAL LOW WILL BRING NELY WINDS AND MAYBE A FLURRY TO KDAN
EARLY IN THE PERIOD...BUT THIS LOW IS NOT EXPECTED TO HAVE A MAJOR
IMPACT ON TAF SITES. HOWEVER...THE APPROACHING SHORT WAVE AND COLD
FRONT ARE EXPECTED TO SPREAD SIGNIFICANT WEATHER TO ALL TAF SITES
STARTING MID/LATE MORNING. EAST OF THE BLUE RIDGE SOME SNOW SHOWERS AND
A TEMPO MVFR CIG MAY AFFECT KROA/KLYH/KDAN BUT FROPA WILL BRING NWLY
WINDS AND DOWNSLOPE TO BRING VFR CONDITIONS FOR THE LATTER PORTION OF
THE PERIOD. FOR KBCB/KBLF/KLWB THE NWLY WINDS WILL BE UPSLOPE AND THIS
WILL KEEP SNOW SHOWERS AT THESE LOCATIONS WITH MVFR/IFR CIGS/VSBYS.
BEHIND THE FRONT ALL SITES WILL SEE SIGNIFICANT WIND GUSTS AS A WELL
MIXED BOUNDARY LAYER ALLOWS FOR EFFICIENT MOMENTUM TRANSFER OF
INCREASING LOW LEVEL FLOW. EXPECT G40KT AT KROA WITH GUSTS AOA 30KT FOR
KBCB/KLWB/KBLF.
EXTENDED DISCUSSION...
EXPECT VFR SAT AFTERNOON THROUGH SUNDAY WITH SUBSIDING
WINDS...THOUGH SOME MVFR INTO SAT NIGHT POSSIBLE AT BLF.
THE NEXT LOW PRESSURE SYSTEM WILL ARRIVE ON SUNDAY NIGHT.
CONFIDENCE IS HIGH THAT POOR FLYING WEATHER WILL TAKE PLACE
DURING MONDAY AND TUESDAY. THIS SYSTEM WILL LIKELY BRING WINTRY
PRECIPITATION TO MUCH OF THE AREA...BUT FURTHER UPDATES FROM THE
LONGER RANGE MODELS MAY IMPACT THE DETAILS ON PRECIPITATION TYPE
AND STORM TRACK.
&&
.CLIMATE...
COLDEST AIR OF THE SEASON ARRIVES THIS WEEKEND. SEVERAL RECORD LOW
MAX TEMPERATURES AND LOW TEMPERATURES ARE POSSIBLE. BELOW ARE THE
CURRENT RECORDS FOR SATURDAY 2/13 AND SUNDAY 2/14.
SATURDAY 02/13/2016
SITE MINT YEAR LOMAX YEAR
KBLF 4 1988 19 1988
KDAN 11 1955 32 1981
KLYH 5 1979 9 1899
KROA 8 1917 18 1914
KRNK -4 1969 14 1955
SUNDAY 02/14/2016
SITE MINT YEAR LOMAX YEAR
KBLF 5 1971 16 1960
KDAN 15 1986 32 1986
KLYH 4 1899 24 1905
KROA 10 1943 26 1986
KRNK -2 1969 24 1986
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
SUNDAY FOR VAZ007-009>020-022>024-032>035.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR VAZ007-009-
015.
NC...WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
SUNDAY FOR NCZ001-002-018.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR NCZ001-018.
WV...WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
SUNDAY FOR WVZ042>044-507.
WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR WVZ042-043-
508.
WIND CHILL WARNING FROM 11 PM THIS EVENING TO 10 AM EST SUNDAY
FOR WVZ508.
&&
$$
SYNOPSIS...JH/MBS
NEAR TERM...JH/MBS
SHORT TERM...RAB
LONG TERM...AMS/RAB
AVIATION...MBS/WP
CLIMATE...CF
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
354 AM EST SUN FEB 14 2016
.SYNOPSIS...
09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A PROGRESSIVE UPPER
LEVEL PATTERN ACROSS THE CONUS EARLY THIS MORNING. DEEP AND VERY
COLD LONGWAVE TROUGHING REMAINS OVER THE NORTHEASTERN STATES...BUT
IS BEGINNING TO SHOW SIGNS OF LIFTING NORTHEASTWARD. FURTHER
UPSTREAM A STRONG NORTHERN STREAM JET IS ARRIVING OVER THE
PACIFIC NORTHWEST/BRITISH COLUMBIA COASTS BEFORE SPILLING OVER THE
ROCKIES INTO A SHORTWAVE TROUGH MIGRATING THROUGH THE NORTHERN
PLAINS/UPPER MIDWEST. CLOSER TO HOME THE UPPER PATTERN IS MORE
QUIET...WITH A GENERALLY ZONAL FLOW ALONG THE NORTHERN GULF COAST
INTO THE FLORIDA PENINSULA. COLUMN OVER OUR HEADS REMAINS QUITE
DRY THIS MORNING...AND THIS DRY AIR COMBINED WITH LITTLE TO NO
SYNOPTIC FORCING FOR ASCENT IS PROVIDING CLEAR SKIES.
AT THE SURFACE...1035MB HIGH PRESSURE CENTERED OVER WEST VIRGINIA
CONTINUES TO RIDGE SOUTHWARD INTO THE EASTERN GULF AND OVER THE
FLORIDA PENINSULA...PROVIDING A GENERAL NORTHEASTERLY SYNOPTIC
FLOW ACROSS THE REGION. TEMPERATURES AS OF 4 AM ARE SEASONABLY
COOL...WITH MIDDLE 30S UP TOWARD CHIEFLAND AND GENERALLY 40S
ELSEWHERE. STILL SOME POTENTIAL FOR AN HOUR OR SO OF TEMPERATURES
NEAR FREEZING ACROSS PORTIONS OF INTERIOR LEVY COUNTY BEFORE THE
SUN RISES...WITH A TOUCH OF FROST IN PLACES. HOWEVER...OCCASIONAL
PUFFS OF WIND TO AROUND 5 MPH SHOULD PREVENT COMPLETE DECOUPLING
OF THE BOUNDARY LAYER...KEEP THINGS SLIGHTLY MIXED...AND PREVENT
TEMPS FROM GETTING TOO LOW. IT MAY BE A COOL MORNING FOR US...BUT
IT COULD CERTAINLY BE WORSE. WAS JUST LOOKING AT THE OBSERVATIONS
ACROSS NEW ENGLAND...AND BOSTON LOGAN INTERNATIONAL AIRPORT (JUST
AS AN EXAMPLE) HAD AN AIR TEMPERATURE OF -7 F...AND A WIND CHILL
OF -33 F. MAKES THINGS SEEM NOT QUITE AS CHILLY AROUND THESE
PARTS.
&&
.SHORT TERM (TODAY THROUGH MONDAY)...
A VERY PLEASANT DAY ON TAP FOR THE SECOND HALF OF THE WEEKEND
AFTER A SEASONABLY COOL START TO THE MORNING. ZONAL FLOW ALOFT AND
HIGH PRESSURE AT THE SURFACE WILL KEEP THE FORECAST DRY. LOW LEVEL
WINDS SHIFT MORE TO THE EAST THROUGH THE DAY AND BEGIN TO MIGRATE
SOME HIGHER LEVELS OF MOISTURE ACROSS THE PENINSULA FROM THE
ATLANTIC BELOW 850MB. WITH DIURNAL MIXING WORKING ON THIS ADDED
MOISTURE...SHOULD SEE A FEW-SCT SHALLOW CUMULUS FIELD DEVELOP
MIDDAY INTO THE EARLY AFTERNOON...MAKING THE FORECAST MOSTLY SUNNY
TO PARTLY SUNNY. VERY DRY AIR REMAINS ABOVE 850MB...SO IF WE MIX
EFFICIENTLY ENOUGH...WE MAY LOOSE THE SCT CLOUDS LATE IN THE DAY.
WILL HAVE TO SEE IF WE CAN MIX THAT HIGH. TEMPERATURES END UP JUST
A TAD BELOW NORMAL FOR MID FEBRUARY...WITH MID 60S FAR NORTH...TO
THE UPPER 60S CENTRAL ZONES...AND LOWER 70S SOUTH. MAY BE A FEW
DEGREES COOLER AT THE SHORE FOR EACH OF THESE AREAS AS WINDS
SLACKEN AND POTENTIALLY TURN LIGHT ONSHORE FOR A BRIEF TIME THIS
AFTERNOON.
FAIR AND DRY WEATHER CONTINUES FOR TONIGHT...WITH LOW TEMPERATURES
NOT QUITE AS COOL. LOOKING FOR LOWS IN THE UPPER 40S FAR
NORTH...AND 50S ELSEWHERE. WE CAN ALL HANDLE THAT. DURING THE
OVERNIGHT...WELL OFF TO THE WEST AND NORTHWEST...OUR NEXT WEATHER
SYSTEM WILL BEGIN TO TAKE SHAPE. WEAK SHORTWAVE ENERGY WILL EJECT
OFF THE SOUTHERN PLAINS INTO THE WESTERN GULF OF MEXICO...WHILE
NORTHERN STREAM ENERGY DIVES SOUTHEAST THROUGH THE CENTRAL PLAINS.
BY THE END OF THE NIGHT...LOW PRESSURE WILL BEGIN TO TAKE SHAPE
NEAR THE ARKLATEX REGION. THIS SYSTEM WILL BRING OUR NEXT RAIN
CHANCES BEGINNING LATER MONDAY INTO MONDAY NIGHT.
GENERALLY SPEAKING...MONDAY WILL BE ANOTHER DRY DAY. HOWEVER...A
FEW THINGS WILL COME INTO PLACE LATE IN THE AFTERNOON WHICH
SUGGEST A FEW WIDELY SCT SHOWERS COULD BREAK OUT. CURRENTLY HAVE A
20% POP IN THE FORECAST FOR MOST AREAS AFTER 2 PM. MOISTURE WILL
STILL BE KIND OF LACKING THROUGH THE COLUMN MONDAY AFTERNOON...BUT
WILL BE WATCHING THAT INITIAL SHORTWAVE APPROACH THE REGION LATE
IN THE DAY...SPREADING A BROAD SWATH OF QVECTOR CONVERGENCE
ACROSS THE PENINSULA AHEAD OF IT. ALONG WITH THIS WEAK SYNOPTIC
SUPPORT FOR LIFT...MID-LEVEL LAPSE RATES WILL BE FAIRLY DECENT
(6-7C/KM)...OVER DECENT TERRESTRIAL DIURNAL HEATING. GIVEN SOME
KINEMATICS AND THE DECENT THERMODYNAMICS...WOULD BE SURPRISED IF
WE DID NOT SEE A FEW SHOWERS BREAK OUT BY THE TIME WE REACH PEAK
HEATING. EITHER WAY...SHOWERS WILL BE WIDELY SCT AND BRIEF IN
NATURE...SO IMPACT WILL BE MINOR. OTHERWISE...LOOKING FOR A SLOW
INCREASE IN CLOUDS THROUGH THE DAY...WITH TEMPERATURES RISING INTO
THE 70S. ONCE AGAIN...AN ONSHORE COMPONENT TO THE WIND AT THE
IMMEDIATE SHORE DURING THE AFTERNOON SHOULD KEEP THE BEACHES
SEVERAL DEGREES COOLER THAN LOCATIONS EVEN JUST A MILES OR TWO
INLAND.
BETTER CHANCES FOR SHOWER OR EVEN A STORMS ARRIVE MONDAY NIGHT
WITH THE ACTUAL COLD FRONT. AT THIS TIME...THE THREAT FOR STRONG
TO THUNDERSTORMS ACROSS OUR FORECAST AREA IS LOW. MORE ON THIS
PART OF THE FORECAST AND BEYOND IN THE LONG TERM DISCUSSION BELOW.
&&
.LONG TERM (TUESDAY THROUGH NEXT SATURDAY)...
UPPER LEVEL TROUGHING OVER THE EASTERN STATES CONTINUES THROUGH WED
AS A SHORT WAVE TROUGH SWINGS ACROSS THE NORTHERN GULF COASTAL
STATES TO THE MID-ATLANTIC COAST...DRAGGING A SURFACE LOW WITH IT
THAT TRAILS A COLD FRONT SOUTHWARD. THIS FRONT CROSSES THE GULF
COAST AND FL EARLY TUE THEN EXITS BY TUE NIGHT. IN RESPONSE
HIGH PRESSURE RIDGING ACROSS FL FROM THE ATLANTIC WILL SHIFT EAST
WITH LOW LEVEL FLOW TURNING FROM SOUTHEAST TO SOUTHWEST...THEN
NORTHWEST BEHIND THE FRONT. THE SOUTHERLY COMPONENT OF THE FLOW WILL
HELP MOISTEN THE ATMOSPHERE BUT ONLY MODERATELY. MODEL PWAT VALUES
RANGE IN THE 1 TO 1.5 INCH RANGE. WHILE THE MOISTURE WILL BE SOMEWHAT
LIMITED THERE WILL STILL BE ENOUGH...ALONG WITH SOME LIFT PROVIDED BY
THE FRONT...TO SUPPORT CHANCE-LIKELY SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS. THE BEST ODDS OF STRONG TO SEVERE STORMS IS EXPECTED
TO STAY WELL NORTH OF THE AREA...CLOSER TO THE SHORT WAVE TROUGH AND
SURFACE LOW.
FOR WED THROUGH SAT - THE UPPER TROUGH MOVES TO THE OPEN ATLANTIC AS AN
UPPER RIDGE BUILDS NORTH OVER THE WESTERN STATES THEN SLIDES EAST...
FLATTENING OVER THE SOUTHEAST QUARTER OF THE CONUS BY SAT. AT THE SURFACE
CANADIAN HIGH PRESSURE RIDGES TO THE WESTERN GULF COAST AND MOVES
EAST... SPRAWLING ACROSS THE EASTERN SEABOARD BY FRI THEN SETTLING
IN ACROSS THE SOUTHEASTERN STATES AND THE ADJACENT ATLANTIC FOR
SAT. THE AREA WILL BE DOMINATED BY CLEAR TO SUNNY SKIES AND A COOL
DRY AIR MASS AS LOW LEVEL FLOW TURNS FROM NORTHERLY TO EASTERLY.
TEMPERATURES WILL RUN CLOSE TO SEASONAL...BUT ON THE COOL SIDE FOR
THE MOST PART.
&&
.AVIATION... VFR CONDITIONS EXPECTED TO PREVAIL ACROSS WEST-CENTRAL
AND SOUTHWEST FLORIDA THROUGH THE DURATION OF THE TAF PERIOD.
NORTHEAST WINDS BECOME MORE EASTERLY AFTER SUNRISE AND REMAIN
EASTERLY THROUGH THE DAY. FEW-SCT CUMULUS FIELDS DEVELOPS EAST TO
WEST ACROSS THE PENINSULA DURING THE AFTERNOON HOURS...WITH BASES
GENERALLY 3-4KFT.
&&
.MARINE...
HIGH PRESSURE CENTERED WELL TO OUR NORTH WILL MIGRATE OFF THE
EASTERN SEABOARD TODAY AND TONIGHT. IN RESPONSE...LOCAL WIND WILL
COME AROUND FROM THE NORTHEAST TO A MORE EASTERLY DIRECTION. OUR
NEXT COLD FRONT WILL THEN APPROACH THE EASTERN GULF OF MEXICO
MONDAY...AND PASS THROUGH THE FORECAST WATERS MONDAY NIGHT OR
TUESDAY MORNING. WINDS WILL SHIFT NORTHWEST AND THEN NORTH BEHIND
THIS FRONT FOR THE MIDDLE OF THE WEEK AS HIGH PRESSURE ONCE AGAIN
BUILDS TO OUR NORTH.
&&
.FIRE WEATHER...
HIGH PRESSURE WELL TO OUR NORTH WILL SHIFT EASTWARD INTO THE
ATLANTIC LATER TODAY AND TONIGHT. IN RESPONSE...WINDS WILL SHIFT
FROM NORTHEASTERLY TO EASTERLY LATER TODAY. THE EASTERLY FLOW
BRINGS A SLOW RETURN OF LOW LEVEL MOISTURE FROM THE ATLANTIC
AND PREVENTS RELATIVE HUMIDITY FROM DROPPING BELOW CRITICAL
LEVELS THE REMAINDER OF THE WEEKEND INTO THE EARLY WEEK PERIOD.
THE NEXT COLD FRONT TO IMPACT OUR REGION ARRIVES MONDAY NIGHT OR
TUESDAY MORNING WITH A QUICK ROUND OF SHOWERS. DRY WEATHER RETURNS
BY TUESDAY AFTERNOON...AND CONTINUES THROUGH THE REMAINDER OF THE
WEEK AS HIGH PRESSURE BUILDS SLOWLY DOWN FROM THE NORTH.
FOG POTENTIAL...
NO FOG IS EXPECTED THROUGH THE REMAINDER OF THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 70 55 75 62 / 0 0 20 50
FMY 73 56 77 64 / 0 0 20 30
GIF 69 54 76 61 / 0 10 20 50
SRQ 69 56 72 61 / 0 0 20 40
BKV 70 53 77 59 / 0 0 20 60
SPG 69 57 73 62 / 0 0 20 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH TUESDAY EVENING FOR
COASTAL CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL
SARASOTA.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
324 AM CST SUN FEB 14 2016
.SHORT TERM...(Today)
ISSUED AT 324 AM CST SUN FEB 14 2016
08z/2am water vapor imagery shows a vigorous short-wave trough over
eastern Nebraska. A narrow band of snow has developed well in
advance of this feature across the central sections of Iowa and
Illinois in association with strong 700-500mb layer frontogenesis.
Latest radar imagery/surface obs show the snow band centered along a
Galesburg...to Lincoln...to Marshall line. This band is expected to
gradually lift northward over the next few hours, as frontogenetic
forcing shifts northward and weakens. Snowfall of one half inch or
less will be likely with this initial burst of snow early this
morning. The main precip event will hold off until later this
morning as stronger/more widespread synoptic lift associated with
the short-wave arrives. HRRR seems to be handling the current
precip field better than any other model, so have followed its
solution closely in the short-term. It shows snow rapidly
developing in advance of the approaching wave and spreading eastward
into central Illinois between 15z and 18z. Based on speed of wave,
a 4-5 hour period of light to moderate snow is expected from late
morning through mid-afternoon before the precip begins to diminish
from west to east late in the day. Total snowfall still appears to
be 2-3 inches across most areas, with the highest totals of 4-5
inches focused along/northwest of the Illinois River. Will continue
the Winter Weather Advisory through 6pm accordingly.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 324 AM CST SUN FEB 14 2016
All models show the strongest lift quickly shifting east of the area
late this afternoon into the early evening, suggesting a rapid end
to the accumulating snow. Will linger chance PoPs across the north
and east through the evening, then will go dry across the board
overnight. Forecast soundings show a loss of ice crystals within
the profile, resulting in a period of light freezing drizzle as the
precip ends.
Monday still appears to be a cool and mostly dry day: however, a few
of the models are showing some light precip with another short-wave
skirting through the area. The GFS is the most bullish with precip,
while the NAM and ECMWF show very little. Given presence of at
least weak lift, will carry slight chance PoPs for rain/snow across
the southern half of the KILX CWA Monday afternoon.
A more significant wave will push into the region on Tuesday,
bringing another round of light precip. Models generally track the
500mb vort max right across central Illinois, resulting in most of
the precip being focused across the northern half of Illinois.
Thermal profiles will be cold enough to support snow initially late
Monday night into Tuesday morning: however, as temperatures climb
into the upper 30s and lower 40s, the snow will transition to a
rain/snow mix or all rain by Tuesday afternoon. Minor snow
accumulations of 1 inch or less are expected during the morning
before the snow mixes with/changes to rain.
After that, the big weather story for the end of the week will be a
pronounced warming trend as upper-level ridging builds across the
Midwest. High temperatures will reach the upper 40s and lower 50s
on Thursday, then will climb even higher into the upper 50s and
lower 60s by Friday. A weak cold front will push through Illinois
on Friday, with 00z Feb 14 models now pulling back on their QPF.
Will still mention low chance PoPs for rain showers with FROPA on
Friday, followed by a return to mild/dry weather next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1140 PM CST SAT FEB 13 2016
Snow has begun in western parts of IL, but radar shows it is along
a narrow band. Believe this is just acting to moisten the lower
levels some. So thinking is not much snow will occur with this, so
will just have a TEMPO group at all sites overnight for 2hrs of
light snow with MVFR vis and cigs 3.5kft or above. Then as the
main wave reaches the area in the morning, more snow arrives,
starting around 15z at SPI and PIA with IFR vis and cigs in the
MVFR range. Based on HiRes models, that pockets of more intense
snowfall will be possible so will have TEMPO group at all sites
for vis below 1sm and cigs below 1kft...LIFR conditions. These
conditions will be in the late morning in the west to afternoon in
the east. As snow departs to the east, conditions will gradually
improve during the afternoon and then snow should completely stop
in the evening hours, though PIA and BMI may see light snow last
longer, being closer to the main mid level wave. Winds will be
southeast through the period. Wind speeds will around 10kts overnight
and into the morning hours, but then increase tomorrow with gusts
over 20kts. Once the snow begins to taper off, speeds will
decrease and winds will become more south-southeast.
&&
.ILX Watches/Warnings/Advisories...
Winter Weather Advisory until 6 PM CST this evening for
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
316 AM CST SUN FEB 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 222 AM CST SUN FEB 14 2016
Cold front moving through the area early this morning bumping winds
briefly behind the boundary to gusts in the 20 knots range
locally. The larger observation picture and local GFS MOS
guidance suggests winds will quickly become lighter and westerly
this morning. Stratus will be mainly confined to the extreme
south central counties and based on the HRRR is likely to exit by
11 or 12 UTC. The consensus of most of the models data for this
afternoon points toward highs in the mid to upper 50s; perhaps
pushing 60 degrees along the Oklahoma line. However the model
variance is quite low lending to better confidence. Light winds
and cloudy skies are likely tonight as a secondary shortwave seen
for several runs now, rotates through the region. The GFS is the
only model producing any measurable QPF while others strongly
suggestive of a completely dry passage. The models are a few
degrees warmer than most MOS solutions.
.LONG TERM...(Monday THROUGH Saturday)
ISSUED AT 222 AM CST SUN FEB 14 2016
The remainder of the week is a story of a strong warming trend,
incrementally each day, to highs likely in the upper 70s and low
80s by Thursday. With such warm temperatures by Thursday,
critical fire weather may become a concern if gusts are
sufficient in the afternoon.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Sunday NIGHT)
ISSUED AT 152 AM CST SUN FEB 14 2016
VFR conditions will persist through the remainder of this TAF
period. A cold front moving through the area will create
moderately gusty northwest winds through the morning hours that
will weaken to light westerly with the loss of the stronger
gradient later in the morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 56 31 62 36 / 0 10 0 0
GCK 57 30 64 35 / 0 10 0 0
EHA 58 32 66 36 / 0 0 0 0
LBL 58 30 66 36 / 0 0 0 0
HYS 52 31 58 36 / 10 10 0 0
P28 58 33 64 39 / 0 10 0 0
&&
.DDC Watches/Warnings/Advisories...NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
446 AM EST SUN FEB 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM EST SUN FEB 14 2016
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF OVER
SE CANADA SLOWLY WEAKENING AND ALLOWING A SHRTWV RDG AXIS WITH 12HR
H5 HGT RISES UP TO 100M TO BRING LARGER SCALE SUBSIDENCE TO THE CWA.
SOME LK CLDS/LIGHT LES IS STILL LINGERING OVER THE TIP OF THE
KEWEENAW AND IN THE SN BELTS E OF MUNISING UNDER AREA OF H85 TEMPS
AOB -20C/LLVL NW FLOW...BUT SUBSIDENCE HAS HAD A SGNFT IMPACT ON
LIMITING THE INTENSITY OF THIS PCPN. ELSEWHERE SKIES HAVE CLEARED.
UNDER THE MOCLR SKIES ACRS THE W AND CENTRAL/PWAT NEAR 0.05 INCH OR
30 PCT OF NORMAL/LGT WINDS ASSOCIATED WITH SFC HI PRES PASSING THRU
WI...TEMPS AT SOME OF THE INTERIOR COLD SPOTS IN THAT AREA HAVE
FALLEN WELL BLO -20F. LOOKING TO THE W...THERE ARE TWO SHRTWVS OF
INTEREST. THE STRONGEST IS SLIDING ESEWD THRU THE DAKOTAS...WHILE
THE OTHER DISTURBANCE IS MOVING E INTO FAR SRN MANITOBA. DESPITE
VERY DRY LLVL AIR DEPICTED ON THE 00Z MPX RAOB... SOME LO/MID CLDS
AHEAD OF THESE SHRTWVS ARE PUSHING E THRU MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON CLD/POP TRENDS THIS
AFTN/TNGT ASSOCIATED WITH DISTURBANCES TO THE W AND INCRSG SLY FLOW/
WAA UNDER TIGHTENING PRES GRADIENT AS THE WI HI PRES SHIFTS TO THE
E. BIGGEST CONCERN IS POTENTIAL FOR SOME LES OFF LK MI WITH THE
INCRSG S WIND.
TODAY...STRONGER SRN MOST SHRTWV TO THE W IS FCST TO SLIDE TOWARD
THE LOWER LKS. SINCE ACCOMPANYING DPVA/DEEP LYR QVECTOR CNVGC IS
PROGGED TO STAY TO THE S OF UPR MI...MODELS SHOW VERY DRY MID LVL
AIR LINGERING OVER UPR MI. SOME MID LVL MSTR IS FCST TO MOVE INTO
THE WRN CWA LATER TODAY AHEAD OF THE WEAKER NRN DISTURBANCE...WHICH
IS FCST TO REACH NEAR INL BY 00Z MON. BUT DOWNSLOPE NATURE OF INCRSG
S WIND UNDER TIGHTENING PRES GRADIENT BTWN HI PRES SHIFTING TOWARD
THE MID ATLANTIC AND FALLING MSLP IN MN SHOULD KEEP THE W PCPN FREE
DESPITE THE INCRSG MID CLDS. THE SHORTER TIME GUIDANCE IS IN GOOD
AGREEMENT ON GENERATING SOME LGT LES OFF LK MI BY 18Z WITH SSE SFC-
H925 FLOW FLOWING UP THE LONG AXIS OF LK MI. WHILE THE ORIENTATION
OF THE FLOW UP LK MI AND H85 TEMPS REBOUNDING ONLY TO ARND -15C ARE
FAVORABLE...THE DRYNESS OF THE AIRMASS IN PLACE PER THE 00Z GRB RAOB
AS WELL ACYC NATURE OF THE H925 FLOW/LO INVRN BASE NEAR 4K FT AGL
AWAY FM DYNAMIC FORCING ASSOCIATED WITH TWO SHRTWVS TO THE W SHOULD
LIMIT COVERAGE OF SN SHOWERS/POPS AND ESPECIALLY SN TOTALS. WHILE A
FEW PLACES COULD PICK UP AN INCH OF SN...MOST LOCATIONS SHOULD SEE
LESS. INCRSG SUN ANGLE/A GOOD DEAL OF SUNSHINE AWAY FM THE LK CLDS
STREAMING OFF LK MI AND AHEAD OF DEEPER MID LVL MSTR MOVING IN FM
THE W SHOULD ALLOW VERY LO TEMPS THIS MRNG TO RECOVER CLOSER TO
NORMAL THIS AFTN.
TNGT...ARRIVAL OF SOME DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF NRN
SHRTWV TNGT IN THE PRESENCE OF PERSISTENT SLY FLOW UP THE LONG AXIS
OF LK MI AND H85 TEMPS FCST TO REMAIN AS LO AS ABOUT -13C OVER NRN
LK MI THRU 12Z MON WL ALLOW FOR SOME LK ENHANCEMENT OF THE LES IN
THE 06Z-12Z TIME TNGT. MODELS SHOW SOME SHARPER LLVL CNVGC IMPACTING
PORTIONS OF THE SE CWA AS FAR E AS THE GARDEN PENINSULA BY 12Z.
CONSIDERING THE FAVORABLE DEPTH OF THE DGZ AFTER THE ARRIVAL OF THE
DEEPER MSTR...SUSPECT SN FALL RATES COULD REACH 1-2 INCHES PER HR
UNDER THIS AXIS OF CNVGC. ALTHOUGH A GOOD NUMBER OF THE HI RES
MODELS INDICATE THIS AXIS OF LLVL CNVGC WL BE RATHER TRANSIENT...
SOME DO SHOW A SLOWER DRIFT THAT COULD RESULT IN SOME ADVY SN
TOTALS. AWAY FM THE LK MI ENHANCEMENT...ANY SN WL BE LGT...
ESPECIALLY IN AREAS OVER THE W/NW NEAR LK SUP WHERE THE S WIND WL
DOWNSLOPE. LO TEMPS TNGT WL BE MUCH WARMER THAN THIS MRNG WITH
INCRSG MSTR/STEADY SSW FLOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 442 AM EST SUN FEB 14 2016
...ACTIVE PATTERN WITH WINTRY MIX POSSIBLE LATE THIS WEEK...
IN THE LARGE SCALE...ENERGETIC PACIFIC JET STREAM WILL LEAD TO
ACTIVE AMPLIFIED FLOW AND CHANGEABLE WEATHER PATTERN NEXT 7-10 DAYS
ACROSS NORTH AMERICA. MAIN CHANCE OF WIDESPREAD LGT SNOW OCCURS MON
WITH LAKE ENHANCED SNOW POSSIBLE IN AREAS DOWNWIND OF LK MICHIGAN.
BETTER CHANCES OF LAKE EFFECT OFF LK SUPERIOR OCCUR TUE AFTN THROUGH
WED AS MORE COLD AIR SWEEPS OVER GREAT LAKES. NEXT STRONGER SYSTEM
WITH WARM AIR ADVECTION ARRIVES IN SOME SHAPE OR FORM THU/FRI.
WARMING ALOFT WILL LEAD TO LIQUID PRECIP AT SOME POINT THU NIGHT INTO
FRI...BUT THAT MAY BE PRECEEDED BY WIDESPREAD LIGHT TO MODERATE SNOW.
EXTENT OF PRECIP WITH THE SYSTEM IS UNKNOWN THOUGH AS MODELS DIFFER
ON WHERE STRONGEST SFC LOW AND LIFT FOR PRECIP DEVELOPS. PLENTY OF
TIME TO SORT OUT THESE DETAILS. NO MATTER HOW YOU LOOK AT IT APPEARS
A MESSY MIX OF WINTRY WEATHER WOULD OCCUR THU NIGHT INTO FRI.
ON MON...DEEP TROUGHING ALOFT FM THIS WEEKEND WILL BE GONE...BUT
SHORTWAVE TROUGH WILL BE ON ITS WAY TO RE-SHARPENING TROUGHING INTO
TUE. SHORTWAVE AND SFC LOW ON LEADING EDGE OF TROUGHING WILL HELP IN
SPREADING WIDESPREAD LGT SNOW ACROSS CWA. CONVERGENT SRLY FLOW OFF
LK MICHIGAN AND SUFFICIENT OVER-WATER INSTABILITY WITH H85 TEMPS
AROUND -13C OPENS DOOR FOR LAKE ENHANCEMENT MON MORNING INTO EARLY
MON AFTN. MAJORITY OF HIGH RES QPF INDICATES NARROW BAND/S OF LAKE
EFFECT WITH POSSIBILITY OF SNOW RATES OVER 1 INCH PER HOUR HELPED
OUT BY DEEP DGZ OVER 10KFT. MOST GUIDANCE ALSO SHOWS SUCH BANDS
SHIFTING ALONG AND NOT STAYING PUT OVER ONE LOCATION. AREA MOST
FAVORED FOR LAKE ENHANCEMENT AND A FEW INCHES OF SNOW WOULD BE
MENOMINEE COUNTY INTO SOUTHERN DELTA AND SOUTHERN SCHOOLCRAFT
COUNTIES. STILL TOO EARLY TO DO ANY TYPE OF HEADLINE SINCE IT IS
UNDERTAIN WHERE HEAVIER LAKE ENHANCED SNOW OCCURS...BUT MAY NEED A
HEADLINE EVENTUALLY. WILL MENTION HEAVIER SNOW POSSIBILITY IN THE
HAZARDOUS WEATHER OUTLOOK.
GENERALLY QUIET MON NIGHT INTO TUE MORNING AHEAD OF STRONGER
SHORTWAVE AND SFC LOW/TROUGH DROPPING ACROSS MANTIOBA/ONTARIO.
SOUNDINGS SHOW LOW-LEVEL MOISTURE WITH TEMPS WARMER THAN -8C SO
COULD SEE FZDZ POSSIBLE...ESPECIALLY WEST CLOSER TO APPROACHING SFC
TROUGH. MAIN IMPACT OF LOW-LEVEL MOISTURE/CLOUDS WILL BE TO HELP
KEEP TEMPS IN THE MID TEENS TO LOWER 20S. A FAR CRY FM THE BITTER
COLD OCCURRING THIS MORNING. WENT TOWARD WARMER GUIDANCE ON TUE AS
IF TROUGH SLOWS SOME ON TUE...WOULD HAVE OPPORTUNITY FOR TEMPS TO
REACH LOW-MID 30S. TROUGH ARRIVES IN THE AFTN NORTHWEST THEN SWEEPS
OVER REST OF CWA BY EVENING. A BURST OF MODERATE TO HEAVY SNOW ON
TROUGH AXIS SEEMS REASONABLE. THOUGH THIS WOULD BE BRIEF...ITS
ARRIVAL MAY TIME OUT WITH AFTN/EVENING COMMUTE. WILL BE SOMETHING
TO KEEP AWARE OF. LAKE EFFECT IN THE WAKE OF THE TROUGH SHOULD BE
OKAY TO START BUT AS LARGE HIGH PRESSURE QUICKLY BUILDS IN...EXPECT
IT TO BEGIN TO STRUGGLE. SOUNDINGS SHOW QUICKLY DEVELOPING
SUBSIDENCE WITH GFS POINT AT P53 /MUNISING/ SHOWING INVERSIONS OVER
6-8KFT TUE EVENING LOWERING TO 4-5KFT BY MIDNIGHT. GOOD PART OF DGZ
IS WITHIN THE LAKE CONVECTIVE LAYER...BUT SUBSIDENCE ALOFT AND QUICK
FORMATION OF ANTICYCLONIC SFC FLOW WITH THE HIGH BUILDING IN SHOULD
LIMIT LES INTENSITY. KEPT POPS HIGH...BUT QPF/SNOW QUICKLY COMES
DOWN AFT TUE EVENING. GUSTY NW WINDS 20-30 MPH WITH THE COLD AIR
ADVECTION IN BLYR SHOULD LEAD TO BLSN/LOWER VSBY AND COULD TIP THIS
TO NEEDING AN ADVY. JURY STILL OUT ON THAT THOUGH. WILL MENTION IN
THE HAZARDOUS WEATHER OUTLOOK.
LAKE EFFECT RUNS ITS COURSE ON WED AND AS SFC RIDGE CROSSES WED AFTN
INTO WED EVENING...SHOULD SHUT DOWN ON WED EVENING WITH LOSS OF
ONSHORE FLOW. SCT MID-HIGH CLOUDS...BUT MAY BE ANOTHER CHILLY NIGHT
WITH THE RIDGE IN THE VCNTY. GIVEN THIS SETUP PROBABLY DID NOT GO
COLD ENOUGH AND LATER SHIFTS MAY NEED TO LOWER TEMPS BELOW CONSENSUS.
LOWEST GUIDANCE SHOWING MINS IN THE SINGLE NUMBERS BLO ZERO FOR THE
INTERIOR.
ATTN LATE THIS WEEK IS ON STRONG WARM AIR ADVECTION PATTERN AS SFC
RIDGE SLIDES OVER NEW ENGLAND AND STRONG SFC LOW...THANKS IN PART TO
THAT VIGOROUS PACIFIC JET STREAM MENTIONED AT THE TOP...EXPANDS OVER
FM THE CANADIAN ROCKIES TO THE NORTHERN PLAINS. COLD AIR ALOFT WILL
GIVE WAY TO H85 TEMPS ABOVE ZERO AS EARLY AS THU EVENING WITH SURGE
OF WARMER AIR /H85 TEMPS MAYBE AS WARM AS +6C/ WASHING ACROSS THE
WESTERN GREAT LAKES ON FRI. WARMING EVENTUALLY MAKES IT TO SFC WITH
HIGH TEMPS WELL INTO THE 30S IF NOT INTO LOW 40S FOR PARTS OF
WESTERN CWA. UNTIL WARMING MAKES IT TO SFC...THE WARM AIR ALOFT WILL
RESULT IN THE SNOW THAT DEVELOPS IN WARM AIR ADVECTION PATTERN THU
AFTN INTO THU NIGHT TO CHANGE TO LIQUID PRECIP FM WEST TO EAST LATE
THU NIGHT INTO FRI. PRECIP COULD BE ENHANCED DEPENDING ON STRENGTH
OF SHORTWAVE DIGGING ACROSS THE UPPER GREAT LAKES. TEMPS WILL BE ON
THE RISE BUT LINGERING COLD TEMPS NEAR SFC COULD RESULT IN FZRA AND
ICING ISSUES AT LEAST BRIEFLY FOR PARTS OF CWA. SINCE S FLOW IS
STRONG AS SEEN BY THE H85 WINDS NEAR 50 KTS INTO WI ON THU NIGHT AS
THE SFC HIGH IS MORE EAST OF HERE VERSUS NORTHEAST /LIMITING COLD
DRY EASTERLY SFC FLOW THAT WOULD TEMPER SFC WARMING/...THINK THE
WARMING AT THE SFC WILL ARRIVE PRETTY QUICKLY SO MIXED PRECIP SHOULD
CONVERT TO RAIN EVEN AT THE SFC LATER FRI MORNING INTO FRI AFTN.
WILL CONTINUE TO MENTION WINTRY MIX AND ICE POTENTIAL IN THE
HAZARDOUS WEATHER OUTLOOK.
TREND IS FOR COOLER TEMPS TO RETURN NEXT SAT ONCE THE LARGE SFC LOW
AND WARM FRONT PASS TO THE EAST. JUST A SMALL CHANCE FOR SNOW
SHOWERS AT THAT TIME. CONSENSUS GUIDANCE UTILIZED FOR TEMPS WHICH
BROUGHT TEMPS BACK INTO THE 20S TO LOWER 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1221 AM EST SUN FEB 14 2016
WINDS BACKING SW AS A HIGH PRES RIDGE MOVES E ACROSS AREA HAVE
LIFTED LAKE EFFECT SNOW SHOWERS NORTH OF KCMX LATE THIS EVENING.
EXPECT VFR CONDITIONS AT ALL TAF SITES INTO SUN AFTERNOON. A S-SE
FLOW DEVELOPING LATER SUN AFTERNOON ALONG WITH AN UPPER DISTURBANCE
MOVING IN FROM THE WEST WILL BRING INCREASING CLOUDS TO KSAW AND
KIWD WITH CIGS LOWERING TO MVFR TOWARD EVENING. CIGS WILL LOWER
TOWARD MVFR AT KCMX BY LATE SUN EVENING. SSE FLOW WILL LIKELY BRING
SOME LIGHT LAKE EFFECT SNOW INTO KSAW BY LATE EVENING AS WELL.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 AM EST SUN FEB 14 2016
AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES DEPARTING TO THE E AND
A LO PRES TROF APPROACHING FROM THE W...EXPECT LIGHT WINDS TODAY
OVER THE LAKE TO INCREASE TO S WINDS UP TO 30 KTS TONIGHT. THE
HIGHEST WINDS WILL OCCUR NEAR THE CANADIAN BORDER OVER THE E
HALF...WHERE A FEW GALE FORCE GUSTS TO 35 KTS ARE POSSIBLE. THESE
WINDS WILL DIMINISH ON MON UNDER A WEAKENING GRADIENT. AFTER A
PERIOD OF RELATIVELY LIGHT WINDS LATER ON MON AND MON
NIGHT...ANOTHER ROUND OF STRONG NNW WINDS THAT WILL AT LEAST
APPROACH 35 KT GALES FOR A SHORT TIME WILL DEVELOP TUE NIGHT
FOLLOWING A COLD FRONTAL PASSAGE. BEST CHANCE FOR THESE GALES TO 35
KTS WILL BE OVER THE NCENTRAL AND E HALF. WINDS WILL THEN DIMINISH
WED WITH ARRIVAL OF ANOTHER HIGH PRES RIDGE. BUT STRONGER SSE WIND
UP TO 30 KTS WILL ARRIVE ON THU UNDER A TIGHTENING PRES GRADIENT
BETWEEN THIS HI SHIFTING TO THE E AND ANOTHER APPROACHING LO PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 AM EST SUN FEB 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM EST SUN FEB 14 2016
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF OVER
SE CANADA SLOWLY WEAKENING AND ALLOWING A SHRTWV RDG AXIS WITH 12HR
H5 HGT RISES UP TO 100M TO BRING LARGER SCALE SUBSIDENCE TO THE CWA.
SOME LK CLDS/LIGHT LES IS STILL LINGERING OVER THE TIP OF THE
KEWEENAW AND IN THE SN BELTS E OF MUNISING UNDER AREA OF H85 TEMPS
AOB -20C/LLVL NW FLOW...BUT SUBSIDENCE HAS HAD A SGNFT IMPACT ON
LIMITING THE INTENSITY OF THIS PCPN. ELSEWHERE SKIES HAVE CLEARED.
UNDER THE MOCLR SKIES ACRS THE W AND CENTRAL/PWAT NEAR 0.05 INCH OR
30 PCT OF NORMAL/LGT WINDS ASSOCIATED WITH SFC HI PRES PASSING THRU
WI...TEMPS AT SOME OF THE INTERIOR COLD SPOTS IN THAT AREA HAVE
FALLEN WELL BLO -20F. LOOKING TO THE W...THERE ARE TWO SHRTWVS OF
INTEREST. THE STRONGEST IS SLIDING ESEWD THRU THE DAKOTAS...WHILE
THE OTHER DISTURBANCE IS MOVING E INTO FAR SRN MANITOBA. DESPITE
VERY DRY LLVL AIR DEPICTED ON THE 00Z MPX RAOB... SOME LO/MID CLDS
AHEAD OF THESE SHRTWVS ARE PUSHING E THRU MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON CLD/POP TRENDS THIS
AFTN/TNGT ASSOCIATED WITH DISTURBANCES TO THE W AND INCRSG SLY FLOW/
WAA UNDER TIGHTENING PRES GRADIENT AS THE WI HI PRES SHIFTS TO THE
E. BIGGEST CONCERN IS POTENTIAL FOR SOME LES OFF LK MI WITH THE
INCRSG S WIND.
TODAY...STRONGER SRN MOST SHRTWV TO THE W IS FCST TO SLIDE TOWARD
THE LOWER LKS. SINCE ACCOMPANYING DPVA/DEEP LYR QVECTOR CNVGC IS
PROGGED TO STAY TO THE S OF UPR MI...MODELS SHOW VERY DRY MID LVL
AIR LINGERING OVER UPR MI. SOME MID LVL MSTR IS FCST TO MOVE INTO
THE WRN CWA LATER TODAY AHEAD OF THE WEAKER NRN DISTURBANCE...WHICH
IS FCST TO REACH NEAR INL BY 00Z MON. BUT DOWNSLOPE NATURE OF INCRSG
S WIND UNDER TIGHTENING PRES GRADIENT BTWN HI PRES SHIFTING TOWARD
THE MID ATLANTIC AND FALLING MSLP IN MN SHOULD KEEP THE W PCPN FREE
DESPITE THE INCRSG MID CLDS. THE SHORTER TIME GUIDANCE IS IN GOOD
AGREEMENT ON GENERATING SOME LGT LES OFF LK MI BY 18Z WITH SSE SFC-
H925 FLOW FLOWING UP THE LONG AXIS OF LK MI. WHILE THE ORIENTATION
OF THE FLOW UP LK MI AND H85 TEMPS REBOUNDING ONLY TO ARND -15C ARE
FAVORABLE...THE DRYNESS OF THE AIRMASS IN PLACE PER THE 00Z GRB RAOB
AS WELL ACYC NATURE OF THE H925 FLOW/LO INVRN BASE NEAR 4K FT AGL
AWAY FM DYNAMIC FORCING ASSOCIATED WITH TWO SHRTWVS TO THE W SHOULD
LIMIT COVERAGE OF SN SHOWERS/POPS AND ESPECIALLY SN TOTALS. WHILE A
FEW PLACES COULD PICK UP AN INCH OF SN...MOST LOCATIONS SHOULD SEE
LESS. INCRSG SUN ANGLE/A GOOD DEAL OF SUNSHINE AWAY FM THE LK CLDS
STREAMING OFF LK MI AND AHEAD OF DEEPER MID LVL MSTR MOVING IN FM
THE W SHOULD ALLOW VERY LO TEMPS THIS MRNG TO RECOVER CLOSER TO
NORMAL THIS AFTN.
TNGT...ARRIVAL OF SOME DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF NRN
SHRTWV TNGT IN THE PRESENCE OF PERSISTENT SLY FLOW UP THE LONG AXIS
OF LK MI AND H85 TEMPS FCST TO REMAIN AS LO AS ABOUT -13C OVER NRN
LK MI THRU 12Z MON WL ALLOW FOR SOME LK ENHANCEMENT OF THE LES IN
THE 06Z-12Z TIME TNGT. MODELS SHOW SOME SHARPER LLVL CNVGC IMPACTING
PORTIONS OF THE SE CWA AS FAR E AS THE GARDEN PENINSULA BY 12Z.
CONSIDERING THE FAVORABLE DEPTH OF THE DGZ AFTER THE ARRIVAL OF THE
DEEPER MSTR...SUSPECT SN FALL RATES COULD REACH 1-2 INCHES PER HR
UNDER THIS AXIS OF CNVGC. ALTHOUGH A GOOD NUMBER OF THE HI RES
MODELS INDICATE THIS AXIS OF LLVL CNVGC WL BE RATHER TRANSIENT...
SOME DO SHOW A SLOWER DRIFT THAT COULD RESULT IN SOME ADVY SN
TOTALS. AWAY FM THE LK MI ENHANCEMENT...ANY SN WL BE LGT...
ESPECIALLY IN AREAS OVER THE W/NW NEAR LK SUP WHERE THE S WIND WL
DOWNSLOPE. LO TEMPS TNGT WL BE MUCH WARMER THAN THIS MRNG WITH
INCRSG MSTR/STEADY SSW FLOW.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 PM EST SAT FEB 13 2016
LONG TERM STARTS 00Z MON WITH A SHORTWAVE NEAR SRN LAKE MICHIGAN
THAT WILL CROSS LAKE HURON BY 12Z MON AND THEN MOVE INTO
QUEBEC...AND ANOTHER SHORTWAVE OVER CENTRAL MN THAT WILL MOVE OVER
OR JUST S OF THE CWA LATE SUN NIGHT INTO MON AFTERNOON...AND YET
ANOTHER SHORTWAVE WILL FOLLOW THE SECOND BY ABOUT 12 HOURS. NOT
REALLY LOOKING FOR A LOT OF SYNOPTIC QPF...BUT THE FORCING/MOISTURE
WILL ENHANCE LES OFF LAKE MICHIGAN IN THE SLY FLOW AHEAD OF THE
ACCOMPANYING SFC TROUGH. SLY WIND LAKE EFFECT IS ALWAYS TRICKY...BUT
LOOKS LIKE IT SHOULD START UP AROUND 00Z MON AND REACH A PEAK
BETWEEN 06Z AND 18Z MON WHILE SHIFTING E AND ENDING BEFORE 00Z TUE.
AT THIS POINT...IT LOOKS LIKE THE MOST SNOW WILL FALL ACROSS
MENOMINEE...DELTA...AND SCHOOLCRAFT COUNTIES...AND POSSIBLY INTO
COUNTIES JUST N OF THOSE. THINK WITH S WINDS...THINK MENOMINEE
COUNTY SEEING MUCH LES IS NOT AS LIKELY. OVERALL...ONLY EXPECTING 2
TO MAYBE 3 INCHES IN THESE AREAS. ELSEWHERE...AROUND AN INCH OR LESS.
MAY SEE SOME LIGHT LES OVER W WIND SNOWBELTS MON NIGHT INTO TUE
MORNING AS 850MB TEMPS WILL BE MARGINAL BUT ADDITIONAL SHORTWAVE
WILL PROVIDE SOME ENHANCEMENT. NOT LOOKING AT SIGNIFICANT AMOUNTS.
SFC TROUGH MOVES THROUGH TUE AHEAD OF AN UPPER WAVE. THIS TURNS
WINDS OUT OF THE NW-NNW BY TUE AFTERNOON/EVENING AND DROPS 850MB
TEMPS TO AROUND-15Z BY 00Z WED AND -19C BY 12Z WED. A SFC RIDGE
MOVES THROUGH BY 00Z THU...ENDING MOST OR ALL LES. NOT EXPECTING
SIGNIFICANT SNOWFALL AMOUNTS GIVEN CHANGING WIND DIRECTIONS AND
QUICK ENTRANCE OF THE RIDGE.
COULD SEE A MORE POTENT SYSTEM LATE IN THE WEEK...WITH THE
POSSIBILITY OF SNOW...RAIN...AND FREEZING RAIN. HOWEVER...CONFIDENCE
EVEN IN THE GENERAL STRENGTH/TRACK OF THE SYSTEM IS LOW AS MODELS
VARY FROM RUN TO RUN AND DISAGREE MODEL TO MODEL. CERTAINLY LOOKS
LIKE A WARMUP IS IN STORE FOR AT LEAST THU NIGHT AND FRI...BUT CAN
NOT SAY MUCH ELSE WITH CONFIDENCE. MAINLY WENT WITH A WINTRY MIX OF
PRECIP IN THE FORECAST...WITH CONSENSUS POPS FIELDS OTHERWISE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1221 AM EST SUN FEB 14 2016
WINDS BACKING SW AS A HIGH PRES RIDGE MOVES E ACROSS AREA HAVE
LIFTED LAKE EFFECT SNOW SHOWERS NORTH OF KCMX LATE THIS EVENING.
EXPECT VFR CONDITIONS AT ALL TAF SITES INTO SUN AFTERNOON. A S-SE
FLOW DEVELOPING LATER SUN AFTERNOON ALONG WITH AN UPPER DISTURBANCE
MOVING IN FROM THE WEST WILL BRING INCREASING CLOUDS TO KSAW AND
KIWD WITH CIGS LOWERING TO MVFR TOWARD EVENING. CIGS WILL LOWER
TOWARD MVFR AT KCMX BY LATE SUN EVENING. SSE FLOW WILL LIKELY BRING
SOME LIGHT LAKE EFFECT SNOW INTO KSAW BY LATE EVENING AS WELL.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 AM EST SUN FEB 14 2016
AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES DEPARTING TO THE E AND
A LO PRES TROF APPROACHING FROM THE W...EXPECT LIGHT WINDS TODAY
OVER THE LAKE TO INCREASE TO S WINDS UP TO 30 KTS TONIGHT. THE
HIGHEST WINDS WILL OCCUR NEAR THE CANADIAN BORDER OVER THE E
HALF...WHERE A FEW GALE FORCE GUSTS TO 35 KTS ARE POSSIBLE. THESE
WINDS WILL DIMINISH ON MON UNDER A WEAKENING GRADIENT. AFTER A
PERIOD OF RELATIVELY LIGHT WINDS LATER ON MON AND MON
NIGHT...ANOTHER ROUND OF STRONG NNW WINDS THAT WILL AT LEAST
APPROACH 35 KT GALES FOR A SHORT TIME WILL DEVELOP TUE NIGHT
FOLLOWING A COLD FRONTAL PASSAGE. BEST CHANCE FOR THESE GALES TO 35
KTS WILL BE OVER THE NCENTRAL AND E HALF. WINDS WILL THEN DIMINISH
WED WITH ARRIVAL OF ANOTHER HIGH PRES RIDGE. BUT STRONGER SSE WIND
UP TO 30 KTS WILL ARRIVE ON THU UNDER A TIGHTENING PRES GRADIENT
BETWEEN THIS HI SHIFTING TO THE E AND ANOTHER APPROACHING LO PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1221 AM EST SUN FEB 14 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 401 PM EST SAT FEB 13 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP TROF OVER SE CANADA
INTO THE NE CONUS WITH THE CORE OF THE COLDEST AIR WELL E OF HERE
NOW. UPSTREAM...NEXT SHORTWAVE OF INTEREST IS MOVING ACROSS THE NRN
ROCKIES. CLOSER TO HOME...WITH LATEST RAP ANALYSIS SHOWING 850MB
TEMPS ACROSS LAKE SUPERIOR RANGING FROM AROUND -19C W TO -25C E...
LES CONTINUES. HOWEVER...UNDER RISING HEIGHTS/SUBSIDENCE...
INVERSION IS DOWN TO AROUND 3KFT W AND 5KFT E. SO...LES IS LIGHT...
BUT STILL EFFECTIVE AT REDUCING VIS OVER THE E DUE TO SMALL
SNOWFLAKE SIZE. WELL AWAY FROM LAKE EFFECT...IT`S BEEN A MOSTLY
SUNNY DAY OVER SCNTRL UPPER MI.
LINGERING LIGHT LES WILL END FROM W TO E TONIGHT AS SFC HIGH PRES
RIDGE PASSES ACROSS THE FCST AREA. WITH MODERATING AIR MASS
RESULTING IN THE DGZ LIFTING INTO THE SHALLOW CONVECTIVE
LAYER...MIGHT BE ABLE TO FLUFF UP AN INCH OR TWO OF SNOW
ACCUMULATION WHERE STRENGTHENING LAND BREEZES FOCUS CONVERGENCE...
MOST LIKELY IN THE E HALF OF ALGER/NRN SCHOOLCRAFT COUNTIES. RIDGE
WILL ARRIVE OVER WRN UPPER MI EARLY THIS EVENING AND THE E
OVERNIGHT. LOSS OF LAKE EFFECT CLOUDS WITH BACKING WINDS WILL BE
REPLACED BY SOME INCREASE IN HIGH CLOUDS IN WAA PATTERN AHEAD OF
SHORTWAVE MOVING INTO THE NRN/CNTRL PLAINS. THAT SAID...ALL AREAS
WILL SEE AT LEAST A SHORT PERIOD OF VERY GOOD RADIATIONAL COOLING
CONDITIONS. IT STILL APPEARS THE CNTRL FCST AREA WILL HAVE THE
LONGEST PERIOD OF EXCELLENT RADIATIONAL COOLING DUE TO CLEAR SKIES
TO START THE EVENING...LATER ARRIVAL OF HIGH CLOUDS AND LONGER
PERIOD OF LIGHT/CALM WIND. AS WITH PREVIOUS FCSTS...MAINTAINED A MIN
TEMP FCST AT OR BLO THE LOWEST GUIDANCE WITH THE TRADITIONAL COLDEST
SPOTS FALLING TOWARD -20F. MOST IF NOT ALL LOCATIONS WILL FALL BLO
0F.
ON SUN...SHORTWAVE MOVING OUT OVER THE PLAINS TONIGHT WILL TRACK ESE
WITH ASSOCIATED DEEP LAYER FORCING PER QVECTORS AND BEST ISENTROPIC
ASCENT PASSING S OF UPPER MI. MODEL TREND OF RECENT DAYS TO PUSH
FORCING/PCPN FARTHER S HAS HELD UP IN LATEST MODEL RUNS. AS A
RESULT...DO NOT EXPECT ANY -SN ASSOCIATED WITH THIS FEATURE TO REACH
THE FCST AREA SUN. ATTENTION THEN TURNS TO LES OFF LAKE MICHIGAN
UNDER DEVELOPING/INCREASING SOUTHERLY FLOW ON THE BACKSIDE OF
DEPARTING HIGH PRES. 850MB TEMPS AROUND -17C AT 12Z RISE TO AROUND
-14C BY 00Z MON...CERTAINLY LOW ENOUGH TO SUPPORT LES. LARGE SCALE
ANTICYCLONIC FLOW AND INVERSIONS AT 4-5KFT WILL LIMIT INTENSITY OF
LES. IN ADDITION...MOST HIGH RES MODEL GUIDANCE DEPICT THE LES
MOSTLY AS A BAND LIFTING N ON A WIND CONVERGENCE ZONE. WHILE THIS
MAY LEAD TO A BURST OF MDT SNOWFALL...ESPECIALLY WITH DGZ SOLIDLY IN
THE CONVECTIVE LAYER...THE HEAVIER SNOW WOULD NOT LAST LONG. FOR
NOW...EXPECT SNOW ACCUMULATIONS UNDER 1 INCH...BUT NOT OUT OF THE
QUESTION FOR LOCALIZED INCH OR TWO OF SNOW ACCUMULATION IF THE
CONVERGENCE ZONE IS STRONG.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 PM EST SAT FEB 13 2016
LONG TERM STARTS 00Z MON WITH A SHORTWAVE NEAR SRN LAKE MICHIGAN
THAT WILL CROSS LAKE HURON BY 12Z MON AND THEN MOVE INTO
QUEBEC...AND ANOTHER SHORTWAVE OVER CENTRAL MN THAT WILL MOVE OVER
OR JUST S OF THE CWA LATE SUN NIGHT INTO MON AFTERNOON...AND YET
ANOTHER SHORTWAVE WILL FOLLOW THE SECOND BY ABOUT 12 HOURS. NOT
REALLY LOOKING FOR A LOT OF SYNOPTIC QPF...BUT THE FORCING/MOISTURE
WILL ENHANCE LES OFF LAKE MICHIGAN IN THE SLY FLOW AHEAD OF THE
ACCOMPANYING SFC TROUGH. SLY WIND LAKE EFFECT IS ALWAYS TRICKY...BUT
LOOKS LIKE IT SHOULD START UP AROUND 00Z MON AND REACH A PEAK
BETWEEN 06Z AND 18Z MON WHILE SHIFTING E AND ENDING BEFORE 00Z TUE.
AT THIS POINT...IT LOOKS LIKE THE MOST SNOW WILL FALL ACROSS
MENOMINEE...DELTA...AND SCHOOLCRAFT COUNTIES...AND POSSIBLY INTO
COUNTIES JUST N OF THOSE. THINK WITH S WINDS...THINK MENOMINEE
COUNTY SEEING MUCH LES IS NOT AS LIKELY. OVERALL...ONLY EXPECTING 2
TO MAYBE 3 INCHES IN THESE AREAS. ELSEWHERE...AROUND AN INCH OR LESS.
MAY SEE SOME LIGHT LES OVER W WIND SNOWBELTS MON NIGHT INTO TUE
MORNING AS 850MB TEMPS WILL BE MARGINAL BUT ADDITIONAL SHORTWAVE
WILL PROVIDE SOME ENHANCEMENT. NOT LOOKING AT SIGNIFICANT AMOUNTS.
SFC TROUGH MOVES THROUGH TUE AHEAD OF AN UPPER WAVE. THIS TURNS
WINDS OUT OF THE NW-NNW BY TUE AFTERNOON/EVENING AND DROPS 850MB
TEMPS TO AROUND-15Z BY 00Z WED AND -19C BY 12Z WED. A SFC RIDGE
MOVES THROUGH BY 00Z THU...ENDING MOST OR ALL LES. NOT EXPECTING
SIGNIFICANT SNOWFALL AMOUNTS GIVEN CHANGING WIND DIRECTIONS AND
QUICK ENTRANCE OF THE RIDGE.
COULD SEE A MORE POTENT SYSTEM LATE IN THE WEEK...WITH THE
POSSIBILITY OF SNOW...RAIN...AND FREEZING RAIN. HOWEVER...CONFIDENCE
EVEN IN THE GENERAL STRENGTH/TRACK OF THE SYSTEM IS LOW AS MODELS
VARY FROM RUN TO RUN AND DISAGREE MODEL TO MODEL. CERTAINLY LOOKS
LIKE A WARMUP IS IN STORE FOR AT LEAST THU NIGHT AND FRI...BUT CAN
NOT SAY MUCH ELSE WITH CONFIDENCE. MAINLY WENT WITH A WINTRY MIX OF
PRECIP IN THE FORECAST...WITH CONSENSUS POPS FIELDS OTHERWISE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1221 AM EST SUN FEB 14 2016
WINDS BACKING SW AS A HIGH PRES RIDGE MOVES E ACROSS AREA HAVE
LIFTED LAKE EFFECT SNOW SHOWERS NORTH OF KCMX LATE THIS EVENING.
EXPECT VFR CONDITIONS AT ALL TAF SITES INTO SUN AFTERNOON. A S-SE
FLOW DEVELOPING LATER SUN AFTERNOON ALONG WITH AN UPPER DISTURBANCE
MOVING IN FROM THE WEST WILL BRING INCREASING CLOUDS TO KSAW AND
KIWD WITH CIGS LOWERING TO MVFR TOWARD EVENING. CIGS WILL LOWER
TOWARD MVFR AT KCMX BY LATE SUN EVENING. SSE FLOW WILL LIKELY BRING
SOME LIGHT LAKE EFFECT SNOW INTO KSAW BY LATE EVENING AS WELL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 401 PM EST SAT FEB 13 2016
AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR TONIGHT...WINDS WILL
DIMINISH AND BECOME LIGHT UNDER 15KT FOR A TIME. ONCE THIS HIGH
SHIFTS E OF THE AREA...S WINDS WILL INCREASE UP TO 25-30KT SUN INTO
MON MORNING UNDER THE TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING
HIGH AND AN APPROACHING LOW PRES TROF IN THE PLAINS. THERE COULD BE
A FEW GALE FORCE GUSTS SUN NIGHT OVER THE E HALF OF THE LAKE.
ALTHOUGH WINDS WILL DIMINISH LATER MON...ANOTHER ROUND OF STRONG NNW
WINDS UP TO 30KT WILL DEVELOP TUE/TUE NIGHT FOLLOWING A COLD FRONTAL
PASSAGE. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE
GUSTS. WINDS WILL THEN DIMINISH WED WITH ARRIVAL OF ANOTHER HIGH
PRES RIDGE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
333 AM CST SUN FEB 14 2016
.DISCUSSION...
Issued at 331 AM CST SUN FEB 14 2016
Watching a couple areas of developing precipitation early this
morning. The first is over Iowa and eastern Nebraska ahead of a
shortwave trough dropping out of the Northern Plains. The second is
across eastern KS into southwest MO ahead of a strong 60-kt low-level
jet. The latter area should continue to expand into west central and
into central Missouri through the morning, where forecast soundings
suggest a mix of sleet and snow, and possibly light freezing rain or
freezing drizzle as well. Given the very dry air just off the ground,
current thinking is that sleet may be the more common precip type
across these areas this morning with only light accumulation.
However, if freezing rain/drizzle starts to dominate then a winter
weather advisory may need to be expanded into areas near and south of
US 50.
Both areas of precipitation should merge and overspread much of
northern, central and eastern Missouri later this morning.
Precipitation across these areas should be mostly snow, with as much
as 1 to 2 inches possible near the US 63 corridor where a winter
weather advisory remains in effect through the afternoon. Warm air
advection later today will allow for a quick warm up with much of
western MO and eastern KS rising into the middle to upper 40s by
afternoon.
The remainder of the forecast looks increasingly spring-like as
ridging to the west gradually makes its way into the center of the
nation by Thursday and Friday. This will allow temperatures to rise
into the 50s Monday through Wednesday, and well into the 60s Thursday
and Friday with a few 70 degree readings not out of the question. The
only mentionable chance for precipitation will arrive with another
weak clipper system Monday night and early Tuesday. Could see some
light snow across north central Missouri with this system and mostly
rain elsewhere.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1138 PM CST SAT FEB 13 2016
Widespread VFR cloud cover around 6k ft agl expected to lower into
MVFR category towards sunrise with patchy freezing drizzle and sleet
forming over parts of west central MO, mostly just south and east of
Kansas City and spread towards central MO during the morning hours.
Further north areas of light snow expected to form over north central
and northeast MO with some accumulations the further east you go.
Precipitation will quickly exit east and likely be out of most of the
forecast area by early afternoon with ceilings likewise improving to
VFR.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...Winter Weather Advisory until 6 PM CST this evening for MOZ008-
017-025-033.
&&
$$
UPDATE...MJ
DISCUSSION...Hawblitzel
AVIATION...MJ
Area Forecast Discussion
National Weather Service SPRINGFIELD MO
1156 PM CST SAT FEB 13 2016
.SHORT TERM...(This Evening through Sunday)
Issued at 0217 PM CST SAT Fib 13 2016
Cold and dry air has invaded much of the Missouri Ozarks region this
afternoon. There are some areas across central Missouri that has
barely reached 20 degrees. The main story for tonight into early
tomorrow will be the threat of a light wintry mix and freezing
drizzle. The latest Hi-Res forecast models all indicate very light
precis to begin to develop between midnight and 3 am across
western and southern Missouri. The latest RUC and HRRR even shows
some convective like precis which indicates pockets of sleet
possible.
The overall message for late tonight into tomorrow morning is we
are expecting only very light amounts of a light wintry mix but
could be impacts on roads and travel in the morning. Ground and
road temperatures have had time to cool down over the past 24
hours. The freezing line will settle somewhere near the Missouri
and Kansas border tonight before it begins to retreat eastward
during the morning hours. There will be very light precis falling
across the Missouri Ozarks with the better potential for higher
amounts across the eastern Ozarks. Freezing drizzle and some light
sleet is expected across the western half of the area and a wintry
mix with some light snow is expected across the eastern half of
the area early on. This will slowly transition to just a cold
light rain or drizzle late tomorrow morning into the early
afternoon from west to east.
We will issue a winter weather advisory for light amounts and
possible travel impacts in the morning. Like what we saw a few
weeks ago...it does not take much freezing drizzle to cause big
travel problems in the Ozarks region. All areas in the advisory
area can expect a very light glaze of ice possible. A dusting of
light sleet or light snow can be expected east of Highway 65 with
up to an inch of snow possible from the Highway 63 corridor and
eastward. Most area will warm up above freezing by Sunday
afternoon with some areas out across far western Missouri near 50.
.LONG TERM...(Sunday Night through Saturday)
Issued at 0217 PM CST SAT Fib 13 2016
There may be some fog developing late Sunday night into Monday
morning. This will need to be watched because temperatures again
may be around or slightly below freezing. The best potential for
fog will be along and south of the I-44 corridor across southern
Missouri.
Milder temperatures return on Monday. A quick moving upper level
system across the Midwest on Tuesday may bring a few more clouds
and a slight chance of showers across central Missouri and the
eastern Ozarks. Decent upper Level ridging will develop across
the central U.S. for the middle and end of next week. This will
allow for way above average temperatures for the region. Highs
will be in the 60s and possible lower 70s. A preview of Spring is
coming next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1146 PM CST SAT FEB 13 2016
For the KSGF/KJLN/KBBG tafs: VFR ceilings are expected to lower as
lift and eventually precipitation increases as an upper level
disturbance/jet max approaches from the wnw. Freezing
rain/drizzle (KSGF and KBBG) and liquid rain/drizzle (KJLN) are
expected to develop toward 09-10z then end toward 18z. Believe
lower clouds will hang in at KBBG and KSGF for a longer period
after the precip ends versus KJLN.
&&
.SGF Watches/Warnings/Advisories...
MO...Winter Weather Advisory until noon CST Sunday for MOZ055>058-
066>071-077>083-088>098-101>106.
KS...NONE.
&&
$$
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...DSA
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1142 PM CST SAT FEB 13 2016
.UPDATE...
Issued at 825 PM CST SAT FEB 13 2016
Have made a significant adjustment to the winter weather advisory
by starting it later based on radar and short range model trends.
Regional radar loops shows the northwest-southeast band of snow from
northwest IA through northeast MO will miss the CWA overnight. the
southern edge may nick Schuyler county but no appreciable
accumulations expected. Inspection of the progged IRK sounding
reveals a desert-like sub-cloud region which will evaporate any snow
which falls out of the mid level deck. All that said still expecting
moderately strong isentropic ascent to top-down saturate this arid
zone late tonight resulting in light snow to develop across northern
MO with the best chance for accumulating snow over northeast MO.
Will also be watching for the development of freezing drizzle over
west central MO...mainly south of KC...during the pre-dawn hours.
Still looks like a small window for occurrence before the warm front
pushes through. Trend in HRRR reflectivity output has been to
decrease coverage and intensity as well as contain it more over the
southwestern counties. 00z NAM supports this.
&&
.DISCUSSION...
Issued at 327 PM CST SAT FEB 13 2016
Main forecast challenges deal with weather type and headlines. The
forecast area is really being split by wintry weather, both
spatially and temporally, with snowfall in our northeast and light
freezing drizzle in our south. The snowfall will likely start earlier
(late this evening) than the freezing drizzle, which may hold off
unto closer to sunrise. Strong isentropic ascent will eventually
saturate the lowest several thousand feet of the atmosphere in north
central to northeastern Missouri. Have delayed onset of snow several
hours based on forecast soundings,the large temperature/ dewpoint
depressions on surface observations and the relatively high cloud
bases. Forecast soundings for the Kirksville area saturate around
midnight or perhaps a little later. Have waited until then to
increase PoPs into the likely range. Snow amounts in our northeastern
zones are still expected to be in the 1" to as much as 3" range in
Schuyler County. After coordination with neighbors, have issued a
winter weather advisory for our extreme northeastern counties,
including the Kirksville area.
The other aspect of this wintry episode is the potential for
freezing drizzle in the southern half of the forecast area.
Confidence in this is quite a bit lower than with the snowfall in
the northeast. First, the lowest several thousand feet never really
saturate. Second, by the time saturation begins to lower, the warm
front lifts through, warms the surface above freezing and desaturates
the sounding aloft. So there really only looks like a marginal
potential for several hours when lift is maximized coincident with
the greatest amount of saturation. This seems to be around the 12Z
time frame +/- an hour or two. However, freezing drizzle can have a
major impact on travel as it can be deceptive in it`s ability to
slicken roads. So it`ll be important for people who have to travel
Sunday morning to understand that roads may be slick. But for now,
confidence just isn`t high enough to issue an advisory at this time.
Another clipper system will move through Monday night/ Tuesday
morning. Forecast soundings show the lowest several thousand feet to
be above freezing, even all the way into the northeastern portions of
the forecast area. So for snow, the wave should have little impact
with regards to wintry weather in the forecast area and we should see
just rain or perhaps a rain/snow mix in our northern zones.
The rest of the forecast looks quiet regarding precipitation. An
upper level ridge will spread east with low level flow out of the
south. This will help temperatures soar to well above normal levels
by Thursday into Friday. Highs may be in the 70s in parts of the
forecast area Thursday and potentially into Friday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1138 PM CST SAT FEB 13 2016
Widespread VFR cloud cover around 6k ft agl expected to lower into
MVFR category towards sunrise with patchy freezing drizzle and sleet
forming over parts of west central MO, mostly just south and east of
Kansas City and spread towards central MO during the morning hours.
Further north areas of light snow expected to form over north central
and northeast MO with some accumulations the further east you go.
Precipitation will quickly exit east and likely be out of most of the
forecast area by early afternoon with ceilings likewise improving to
VFR.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...Winter Weather Advisory from 4 AM to 6 PM CST Sunday for MOZ008-
017-025-033.
&&
$$
UPDATE...MJ
DISCUSSION...CDB
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1128 PM CST SAT FEB 13 2016
.UPDATE...
ISSUED AT 910 PM CST SAT FEB 13 2016
SOME WILD WEATHER IN WESTERN SOUTH DAKOTA THIS EVENING WITH
LIGHTNING...LOCALIZED HEAVY RAIN AND SEVERAL WIND GUSTS 45 TO 57
MPH. THE SHORTWAVE TROF TRACKS ACROSS THE NORTHERN PLAINS INTO
IOWA/SOUTHERN WI/IL THROUGH SUNDAY. THE MAIN AREA OF SNOW WILL BE
FROM SD INTO MN/IA/IL THROUGH MORNING. OVERALL DID NOT MAKE ANY
SIGNIFICANT CHANGES TO THE LIGHT SNOW AMOUNTS. NORTHEAST NEBRASKA
AND WESTERN CENTRAL IOWA SHOULD GET CLIPPED BY THE LIGHT SNOW WITH
AN INCH OR SO POSSIBLE. A FEW EARLIER HRRR RUNS WERE HINTING AT
POSSIBLE BANDING OF LIGHT SNOW FARTHER SOUTH...HOWEVER THE LATEST
HRRR DID NOT HAVE THIS. OUR OAX 00Z SOUNDING WAS SATURATED BETWEEN
H800 AND H850MB...WITH DRY AIR BELOW THIS. LIFT INCREASES AND
AROUND 09Z/10Z COULD SEE FLURRIES OR A DUSTING TOWARD TO THE
PLATTE RIVER/METRO AREA.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 306 PM CST SAT FEB 13 2016
PRECIPITATION CHANCES WITH A COUPLE OF SHORTWAVES DIVING THROUGH THE
PLAINS TONIGHT AND MONDAY NIGHT...AND WARMING TEMPERATURES...ARE THE
PRIMARY FORECAST CONCERNS.
STEEPENING NORTHWEST MID LEVEL FLOW IS EXPECTED OVER THE NEXT COUPLE
OF DAYS AS SHORTWAVES ROLLING THROUGH THAT FLOW TONIGHT AND MONDAY
NIGHT CARVE OUT A DEEPER TROUGH IN THE EASTERN STATES. EACH OF THOSE
SHORTWAVES WILL BRING PRECIPITATION CHANCES TO THE PLAINS...BUT
TRACKS OF BOTH LOOK TO FAVOR AREAS TO OUR NORTH AND NORTHEAST FOR
BEST POTENTIAL FOR ACCUMULATING SNOWS.
TONIGHTS SHORTWAVE WAS MOVING THROUGH EASTERN MONTANA THIS AFTERNOON
AND WILL PUSH THROUGH OUR AREA LATE TONIGHT AND SUNDAY MORNING.
SOUTH TO SOUTHEAST LOW LEVEL FLOW WILL INCREASE AHEAD OF
SYSTEM...AND ALONG WITH ABUNDANT CLOUD COVER...EXPECT TEMPERATURES
TO SLOWLY RISE OVERNIGHT FROM THE TEENS OR LOWER 20S TO THE 25 TO 30
DEGREE RANGE BY SUNRISE. PRECIPITATION-WISE...ALREADY SEEING SOME
MID LEVEL REFLECTIVITIES SHOWING UP ON AREA RADARS AS WING OF MID
LEVEL WARM ADVECTION BEGINS. EXPECT THAT AREA TO EXPAND IN COVERAGE
AS WE HEAD TOWARD MIDNIGHT WHEN LAYERED FRONTOGENETICAL FORCING IS
MAXIMIZED. THAT SHIFTS TO THE EAST BY 12Z...TAKING BULK OF
PRECIPITATION WITH IT. SO OUR NORTHEAST COUNTIES HAVE THE BEST
CHANCE FOR ACCUMULATING SNOWS...BUT STILL SHOULD TOTAL JUST AN INCH
OR SO THERE.
BEHIND SHORTWAVE...MODEST MIXING REGIME WILL SET UP AS NORTHWEST
WINDS DOMINATE AND SOME DECREASE IN CLOUD COVER IS EXPECTED. SHOULD
SEE SOME 40S FOR MUCH OF THE CWA SUNDAY AFTERNOON WITH 30S HOLDING
IN THE NORTHEAST. WESTERLY LOW LEVEL WIND COMPONENT WILL REMAIN INTO
MONDAY BEFORE NEXT SHORTWAVE BEGINS TO EJECT TOWARD THE AREA MONDAY
NIGHT. THUS TEMPERATURES WILL REMAIN RELATIVELY MILD AS COMPARED TO
RECENT TEMPS...WITH LOWS IN THE 20S AND HIGHS AGAIN IN THE 40S
MONDAY AFTERNOON...AND PERHAPS WARMER IN THE SOUTH WHERE NO
SNOWCOVER EXISTS AND SOUTHWEST WINDS KICK IN MONDAY AFTERNOON.
SIMILAR SCENARIO IS EXPECTED MONDAY NIGHT AS TONIGHT WITH SHORTWAVE
TRACK FOCUSING BEST PRECIP CHANCES TO OUR NORTH AND EAST. HOWEVER A
BETTER INITIAL MOISTURE PROFILE SUGGESTS A BROADER AREA OF
PRECIPITATION WILL RESULT WHEN WARM ADVECTION OVERSPREADS THE AREA
MONDAY EVENING. HAVE FAIRLY HIGH CHANCE POPS FOR MUCH OF EASTERN
NEBRASKA THEN...WITH AREA SHIFTING INTO WESTERN IOWA AFTER
MIDNIGHT. PRECIPITATION TYPE WILL ALSO BE AN ISSUE WITH MUCH
WARMER TEMPERATURE PROFILE THAN TONIGHT. FORECAST SOUNDINGS
SUGGEST A CHANCE FOR MIXED PRECIPITATION FOR ALL BUT FAR NORTHEAST
NEBRASKA AND WEST CENTRAL IOWA. WILL MAINTAIN A CHANCE FOR RAIN OR
SNOW MOST AREAS UNTIL FINER DETAILS CAN BE WORKED OUT. AND WITH
THE POTENTIAL MIX EXPECTED...AND RELATIVELY MILD TEMPS
OVERNIGHT...SNOWFALL ACCUMULATION FOR MOST AREAS WILL BE MINIMAL.
NORTHWEST LOW LEVEL FLOW TUESDAY AFTERNOON BEHIND SHORTWAVE AGAIN
OFFERS LITTLE IN THE WAY OF COOLING WITH NEUTRAL TEMPERATURE
ADVECTION NOTED. THUS HIGHS AGAIN IN THE 40S FOR MUCH OF EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH 30S IN THE NORTHEAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM CST SAT FEB 13 2016
A WARMING TREND IS EXPECTED THROUGH THE REST OF THE WORK WEEK WITH
RISING MID LEVEL HEIGHTS THE HIGHLIGHT OF THE FORECAST.
NORTHWEST MID LEVEL FLOW WILL BE REPLACED BY MODEST RIDGING BY
WEDNESDAY NIGHT AS TROUGH DIGS JUST OFF THE WEST COAST AND EASTERN
TROUGH SWINGS INTO THE MID ATLANTIC STATES. GRADUALLY WARMING 850
TEMPERATURES FROM SUB ZERO TUESDAY AFTERNOON TO THE MID TEENS
THURSDAY EVENING DEMONSTRATE THE MAGNITUDE OF BACKGROUND
WARMING...SUGGESTING SURFACE TEMPERATURES INTO THE 50S LOOK ON TRACK
BY THEN. PLENTY OF SUNSHINE SHOULD HELP AS WELL.
BY FRIDAY...A SHORTWAVE RIDING THROUGH THE NORTHERN PLAINS WILL PUSH
A TROUGH/COOL FRONT THROUGH OUR REGION...BUT PRECIPITATION WILL
REMAIN WELL TO OUR NORTH. AND ONLY BRIEF COOLING IS FORECAST FRIDAY
NIGHT BEFORE WARM ADVECTION AGAIN KICKS IN FOR SATURDAY.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1125 PM CST SAT FEB 13 2016
SOME LIGHT SNOW COULD AFFECT KOFK FROM 09-12Z. OTHERWISE...VFR
CONDITIONS...BECOMING MVFR BY 09Z-12Z AT KOFK..THEN BACK TO VFR BY
15Z. MVFR AT KOMA 13Z-19Z. SOUTHEAST WINDS AT OR GREATER THAN 12
KNOTS INITIALLY...DROPPING BELOW BY 12-13Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...ZAPOTOCNY
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS Tulsa OK
255 AM CST SUN FEB 14 2016
.DISCUSSION...
The dry low-levels are winning out so far this morning...with the
atmosphere being very slow to moisten. HRRR and RUC both suggest
that light precipitation won`t develop into the forecast until
beyond 12z...and it`s still looking like the deeper valley regions
of Carroll...Madison and Franklin counties will experience the
main impact from any light icing. Have opted to extend the winter
weather advisory until 18z...with temperatures warming above
freezing by early afternoon. Afternoon temperatures across the
remainder of the forecast area will be highly dependent on amount
of clearing...and have nudged highs down a few degrees over the
previous forecast.
The main story for next week will be an impressive warming
trend...especially toward the end of the week. A weak boundary
should work into the region by Tuesday beneath the northwesterly
upper flow...but still expect afternoon highs to reach the 60s in
most locations. The big warmup comes by Thursday and continuing
into Friday as strong south to southwest winds develop. Will
continue to go at or above the warmest guidance numbers...with
current forecast highs for Thursday near record levels.
Temperatures should moderate some going into next weekend...but
still remain well above seasonal norms. Have kept the forecast dry
at this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 53 37 65 44 / 30 0 10 10
FSM 48 37 63 39 / 50 20 10 10
MLC 54 38 65 42 / 30 20 10 0
BVO 55 33 64 34 / 20 0 10 10
FYV 43 31 60 35 / 50 10 10 10
BYV 41 32 59 36 / 50 10 10 10
MKO 49 36 63 38 / 40 10 10 10
MIO 49 33 61 38 / 30 0 10 10
F10 54 37 65 40 / 30 10 10 10
HHW 60 45 67 42 / 20 50 20 0
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...Winter Weather Advisory until noon CST today for ARZ001-002-010-
011-019-020.
&&
$$
SHORT TERM...20
LONG TERM....18
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.
UPDATE ISSUED AT 1009 PM CST SAT FEB 13 2016
A LATE UPDATE...BUT NECESSARY NONE THE LESS. UPGRADED A NUMBER OF
COUNTIES TO A WINTER STORM WARNING FOR HEAVY SNOW. THERE ARE
PRESENTLY AREAS EXPERIENCING 0.5 TO 1.0 INCH AN HOUR SNOWFALL
RATES. EAGLE BUTTE REPORTED 5.5 INCHES OF SNOW ABOUT AN HOUR AGO
AND STILL SNOWING. WITH THE HRRR/RAP UPDATING AND HIGHLIGHTING
ABOUT 6 MORE HOURS OF LIFT/FORCING CAPABLE OF GENERATING THESE
HIGH SNOWFALL RATES OF ACCUMULATION. THIS STORM SYSTEM SHOULD END
UP PRODUCING A WIDESPREAD 5 TO 7 INCH SNOWFALL HIGHLIGHTED MAINLY
WITHIN THE WARNED AREA. UPDATES ARE OUT.
UPDATE ISSUED AT 557 PM CST SAT FEB 13 2016
UPDATED AVIATION DISCUSSION FOLLOWS. ALSO MADE A COUPLE OF UPDATES
TO THE WEATHER GRIDS TO INTRODUCE THUNDER MENTION TO THE FREEZING
RAIN/SLEET AND SNOW THAT IS CONTINUING TO BE FORECAST ACROSS THE
WINTER WEATHER ADVISORY AREA. CLOUD TO GROUND LIGHTNING HAS BEEN
CONSISTENTLY BEING GENERATED ON THE PVA SIDE OF THIS POTENT UPPER
WAVE OVER THE PAST 6 HOURS...INCLUDING AN UPTICK IN LIGHTNING
ACTIVITY TO OVER 30 CG LIGHTNING STRIKES LAST HOUR. WILL CONTINUE
TO MONITOR TRENDS THIS EVENING TO SEE IF/WHEN ANY FORECAST ZONES
MAY NEED TO BE UPGRADED TO A WARNING FOR HEAVY SNOW. LATEST HRRR
OUTPUT SEEMS TO SUGGEST THIS CWA WILL BE MISSED BY THE MOST
INTENSE CONVECTIVELY-INFLUENCED SNOW OVERNIGHT. STAY TUNED.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 235 PM CST SAT FEB 13 2016
FAIRLY ACTIVE SHORT TERM FORECAST FOR THE AREA AS TWO FEATURES
WILL COMBINE TO PRODUCE MODERATE TO OCCASIONALLY HEAVY SNOWFALL
OVER THE CWA. THE STRONG SHORTWAVE THAT WILL SLIDE SOUTHEAST
ACROSS SOUTHWEST SOUTH DAKOTA IS STILL LOCATED IN CENTRAL MONTANA
AT THIS TIME...AND IS LEADING TO A COUPLE AREAS OF PRECIPITATION
IN EASTERN MONTANA (ONE ALONG THE WARM FRONT AND ANOTHER TIED TO
THE SHORTWAVE AND COLD FRONT). CLOSER TO THE AREA...SEEING
PRECIPITATION JUST TO THE WEST OF THE MISSOURI RIVER THAT IS
SLOWLY MOVING EAST-SOUTHEAST. THIS PRECIPITATION IS DUE TO THE
INITIAL AREA OF MID-LEVEL WARM AIR ADVECTION AHEAD OF THE WARM
FRONT STRETCHING SOUTH-SOUTHEAST THROUGH FAR WESTERN SOUTH DAKOTA.
WEBCAMS SHOW THAT THE PRECIPITATION TOWARDS HAAKON/STANLEY
COUNTIES IS IN THE FORM OF RAIN AND WITH SURFACE TEMPERATURES IN
THAT AREA AROUND OR ABOVE FREEZING...DON/T THINK THERE IS TOO MUCH
FREEZING RAIN OCCURRING AT THIS POINT. FARTHER NORTH...RAP
ANALYSIS SOUNDINGS INDICATE THE WARM NOSE ALOFT WEAKENS WHICH
SHOULD TRANSITION THE PRECIP TO SNOW THE FARTHER NORTH YOU HEAD.
OVER THE REST OF THE AREA...CLOUDS HAVE BEEN LOWERING WITH THE
INCREASING LOW LEVEL MOISTURE AND DEPARTING SURFACE RIDGE.
TEMPERATURES ARE STILL FAIRLY COLD OVER NORTHEAST SD...WHERE 2PM
TEMPERATURES RANGE FROM THE UPPER SINGLE DIGITS AT K8D3 TO 13 AT
KABR AND THEN 17 AT KMBG.
MODELS CONTINUING TO STRUGGLE WITH THE TRACK/EVOLUTION OF THE
SHORTWAVE IN MONTANA...WHICH LEADS TO SOME UNCERTAINTY IN THE
FORECAST SNOWFALL OVER N.C./N.E. SOUTH DAKOTA THIS EVENING INTO
THE OVERNIGHT HOURS. LATEST RUNS OF THE RAP AND 12Z GLOBAL
MODELS HAVE TRENDED THE TRACK OF THE STRONGEST FORCING A LITTLE
FARTHER TO THE SOUTHWEST AND IN SOME CASES ONLY BARELY BRUSHING
SOUTHWESTERN SD. WHILE THAT BEST FORCING SLIDES SOUTHWEST OF
MUCH OF THE AREA...STILL HAVE SOME SUPPORT FROM THE UPPER TROUGH
AND ESPECIALLY FROM THE WARM AIR ADVECTION / ISENTROPIC ASCENT
ALONG AND AHEAD OF THAT TROUGH THROUGH THE EARLY OVERNIGHT
HOURS. FAIRLY STRONG LIFT WITH THE WAA (AND SEEN IN THE 700MB
OMEGA) WITH FAVORABLE 850-500MB Q-VECTOR DIVERGENCE.
THEREFORE...EXPECT TO SEE A FAIRLY QUICK HITTING (4-7HR PERIOD)
AREA OF PRECIPITATION MOVING THROUGH THE AREA...ESPECIALLY THIS
EVENING INTO THE EARLY OVERNIGHT HOURS. MODELS HAVE TRENDED QPF
AMOUNTS TO THE NORTH WITH THE MOST RECENT RUNS...SOME EVEN
SHOWING 12HR QPF AMOUNTS EXCEEDING 0.6IN BETWEEN
MOBRIDGE/ABERDEEN. THAT POTENTIAL (LIKELY SOMEWHAT CONVECTIVELY
DRIVEN WITH 750-500MB LAPSE RATES AROUND 7 C/KM) WILL NEED TO BE
WATCHED THROUGH THE EVENING AND IF IT SETS UP AS SHOWN WITH SOME
OF THE HIGHER RES RUNS...MAY NEED TO UPGRADE A FEW COUNTIES TO
WARNINGS. WITH THAT FARTHER NORTH TREND...EXPECT A LITTLE LESS
IMPACT FOR THE SOUTHWESTERN CWA...BUT STILL THINK THE POTENTIAL
FOR FREEZING RAIN THROUGH THE FIRST PART OF THE EVENING BEFORE
TRANSITIONING TO SNOW FOR A BRIEF PERIOD BEFORE ENDING. THAT
NORTHWARD SHIFT SHOULD KEEP SNOWFALL AMOUNTS BELOW 2 INCHES FROM
PIERRE AND SOUTHWEST (WHERE SOME AREAS WILL STAY MAINLY RAIN).
AS FOR SNOWFALL AMOUNTS OVER THE NORTH CENTRAL AND
NORTHEAST...HAVE A GENERAL 3-6 INCHES WITH SNOW RATIOS
INCREASING FROM AROUND 10-1 AROUND THE MISSOURI RIVER TO THE
12-14 TO 1 RANGE OVER THE NORTHEAST. OVER THE NORTHEAST...A GOOD
PORTION OF THE LIFT IS AT OR ABOVE THE DGZ...WHICH WILL LIKELY
LEAD TO MORE COLUMNS IN THE SNOW PROCESS AND MORE POTENTIAL FOR
COMPACTING (ALONG WITH AGGREGATION AS THE SNOW FALLS THROUGH THE
CLOUD LAYER BELOW THE DGZ). THUS...DIDN/T WANT TO GO MUCH HIGHER
THAN THE PREVIOUSLY MENTIONED VALUES ...ALTHOUGH RATIOS COULD
BRIEFLY INCREASE IF THE FORCING ALIGNS A LITTLE LOWER AND IN THE
DGZ. WITH THE HIGHER QPF AND RATIOS...HAVE NEAR WARNING SNOWFALL
AMOUNTS (5.5-6IN) OVER MCPHERSON/EDMUNDS/BROWN/MARSHALL/DAY
COUNTIES. WITH THE VARIABILITY IN THE MODEL RUNS TODAY...DIDN/T
HAVE ENOUGH CONFIDENCE TO UPGRADE TO A WARNING AT THIS POINT AND
THE EVENING SHIFT WILL NEED TO MONITOR FOR A POSSIBLE UPGRADE. IN
ADDITION...WITH THE SNOW OCCURRING LATE THIS EVENING AND DURING
THE EARLY OVERNIGHT HOURS...THOUGHT THE IMPACTS WOULD BE LOWER
THAN IF IT OCCURRED DURING THE DAY.
ONE OTHER ITEM TO MENTION WILL BE THE GUSTY SOUTH-SOUTHEAST
WINDS INITIALLY THIS EVENING AHEAD OF THE TROUGH (GUSTS TO
25-30MPH). THAT WILL LEAD TO PATCHY/AREAS OF BLOWING SNOW AND
WILL CONTINUE TO MENTION THAT IN THE FORECAST/WSW.
FOR THE REST OF THE PERIOD...THE SNOW WILL DIMINISH FROM WEST TO
EAST LATE TONIGHT AND THROUGH THE DAY ON SUNDAY (LARGELY OVER
THE EASTERN HALF/THIRD OF THE CWA). A BROAD SURFACE TROUGH WILL
BE OVER THE AREA AND LIMIT THE WINDS AND IN TURN ANY BLOWING SNOW
CONCERNS. IN ADDITION...WITH THE WARM AIR OVER THE
AREA BEHIND THE WARM FRONT THAT MOVED THROUGH...HIGHS WILL RISE
INTO THE MID/UPPER 20S OVER THE FAR EAST TO THE LOWER 40S ALONG
AND WEST OF THE MISSOURI RIVER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 235 PM CST SAT FEB 13 2016
LOW TEMP FORECAST FOR SUNDAY NIGHT IS A BIT TRICKY. AREA WILL STILL
BE IN A RELATIVELY MILD AIR MASS WITH 925MB TEMPS AROUND 0C TO +2C
AND A LIGHT WEST TO SOUTHWEST SFC WIND. ALTHOUGH...WILL HAVE TO KEEP
IN MIND THE FRESH COAT OF SNOW THAT WILL BE OVER MUCH OF THE AREA.
THERE WILL BE SOME DEGREE OF CLOUD COVER AS WELL...SO TRYING TO
FIGURE OUT WHICH VARIABLES HAVE THE BIGGEST IMPACT ON TEMPS IS
TRICKY.
WILL THEN BE WATCHING THE NEXT PIECE OF SHORTWAVE ENERGY WHICH WILL
BE DROPPING SOUTHEAST THROUGH THE AREA MONDAY NIGHT. HAVE INCREASED
POPS FOR THIS EVENT AS MODELS ARE IN PRETTY GOOD AGREEMENT ON TIMING
AND PLACEMENT OF QPF. AGAIN...COULD BE DEALING WITH MIXED PRECIP
ISSUES AS THERE WILL BE WARM AIR IN PLACE.
YET ANOTHER WAVE MOVES THROUGH TUESDAY NIGHT BUT IS LOOKING RATHER
WEAK AT THIS POINT. SUPERBLEND GAVE SLIGHT CHANCE POPS AND THIS
LOOKS GOOD FOR THE TIME BEING. ONLY CHANGE HERE WAS TO REMOVE THE
SLIGHT CHANCES THEY INITIAL GAVE ON TUESDAY AND HELD THINGS OFF TO
TUESDAY NIGHT PER MODEL DATA.
TEMPS THROUGHOUT THE PERIOD STAY ON THE MILD SIDE...ESPECIALLY BY
THURSDAY WHEN MODELS TRY TO BRING IN SOME VERY MILD AIR. 925MB TEMPS
AROUND +20C SHOW UP IN THE MODELS OVER SOUTHWEST AND SOUTH CENTRAL
SD. SUPERBLEND TEMPS HAVE READINGS AS WARM AS THE 60S OVER THE
SOUTHWEST CWA ON THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1137 PM CST SAT FEB 13 2016
SNOW EVENT IS ONGOING. IFR CONDITIONS SHOULD BEGIN TO IMPROVE AT
KMBG OVER THE NEXT FEW HOURS. KPIR AND KATY MAY BOUNCE IN AND OUT
OF MVFR/IFR CONDITIONS FOR A FEW MORE HOURS...BUT THEN KPIR SHOULD
BEGIN TO IMPROVE WHILE KATY BEGINS TO TANK. KATY AND KABR SHOULD
REMAIN DOWN IN MODERATE TO HEAVY SNOW AND BREEZY SOUTHERLY WINDS
THROUGH SUNRISE BEFORE CONDITIONS BEGIN TO IMPROVE SUNDAY MORNING.
LATE IN THE TAF PERIOD...ANOTHER ROUND OF SUB-VFR CONDITIONS COULD
BE WORKING INTO THE KPIR AND KMBG TERMINALS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR SDZ009-
015-016-034-036.
WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR SDZ007-008-021.
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR SDZ003-
004-033-035-045-048-051.
WINTER WEATHER ADVISORY UNTIL 9 AM CST SUNDAY FOR SDZ005.
WINTER STORM WARNING UNTIL 9 AM CST SUNDAY FOR SDZ006-010-017-018-
037.
WINTER STORM WARNING UNTIL NOON CST SUNDAY FOR SDZ011-019-020-022-
023.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR MNZ039-046.
&&
$$
UPDATE...DORN
SHORT TERM...SRF
LONG TERM...TDK
AVIATION...DORN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1015 PM CST SAT FEB 13 2016
.UPDATE...
ISSUED AT 1009 PM CST SAT FEB 13 2016
A LATE UPDATE...BUT NECESSARY NONE THE LESS. UPGRADED A NUMBER OF
COUNTIES TO A WINTER STORM WARNING FOR HEAVY SNOW. THERE ARE
PRESENTLY AREAS EXPERIENCING 0.5 TO 1.0 INCH AN HOUR SNOWFALL
RATES. EAGLE BUTTE REPORTED 5.5 INCHES OF SNOW ABOUT AN HOUR AGO
AND STILL SNOWING. WITH THE HRRR/RAP UPDATING AND HIGHLIGHTING
ABOUT 6 MORE HOURS OF LIFT/FORCING CAPABLE OF GENERATING THESE
HIGH SNOWFALL RATES OF ACCUMULATION. THIS STORM SYSTEM SHOULD END
UP PRODUCING A WIDESPREAD 5 TO 7 INCH SNOWFALL HIGHLIGHTED MAINLY
WITHIN THE WARNED AREA. UPDATES ARE OUT.
UPDATE ISSUED AT 557 PM CST SAT FEB 13 2016
UPDATED AVIATION DISCUSSION FOLLOWS. ALSO MADE A COUPLE OF UPDATES
TO THE WEATHER GRIDS TO INTRODUCE THUNDER MENTION TO THE FREEZING
RAIN/SLEET AND SNOW THAT IS CONTINUING TO BE FORECAST ACROSS THE
WINTER WEATHER ADVISORY AREA. CLOUD TO GROUND LIGHTNING HAS BEEN
CONSISTENTLY BEING GENERATED ON THE PVA SIDE OF THIS POTENT UPPER
WAVE OVER THE PAST 6 HOURS...INCLUDING AN UPTICK IN LIGHTNING
ACTIVITY TO OVER 30 CG LIGHTNING STRIKES LAST HOUR. WILL CONTINUE
TO MONITOR TRENDS THIS EVENING TO SEE IF/WHEN ANY FORECAST ZONES
MAY NEED TO BE UPGRADED TO A WARNING FOR HEAVY SNOW. LATEST HRRR
OUTPUT SEEMS TO SUGGEST THIS CWA WILL BE MISSED BY THE MOST
INTENSE CONVECTIVELY-INFLUENCED SNOW OVERNIGHT. STAY TUNED.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 235 PM CST SAT FEB 13 2016
FAIRLY ACTIVE SHORT TERM FORECAST FOR THE AREA AS TWO FEATURES
WILL COMBINE TO PRODUCE MODERATE TO OCCASIONALLY HEAVY SNOWFALL
OVER THE CWA. THE STRONG SHORTWAVE THAT WILL SLIDE SOUTHEAST
ACROSS SOUTHWEST SOUTH DAKOTA IS STILL LOCATED IN CENTRAL MONTANA
AT THIS TIME...AND IS LEADING TO A COUPLE AREAS OF PRECIPITATION
IN EASTERN MONTANA (ONE ALONG THE WARM FRONT AND ANOTHER TIED TO
THE SHORTWAVE AND COLD FRONT). CLOSER TO THE AREA...SEEING
PRECIPITATION JUST TO THE WEST OF THE MISSOURI RIVER THAT IS
SLOWLY MOVING EAST-SOUTHEAST. THIS PRECIPITATION IS DUE TO THE
INITIAL AREA OF MID-LEVEL WARM AIR ADVECTION AHEAD OF THE WARM
FRONT STRETCHING SOUTH-SOUTHEAST THROUGH FAR WESTERN SOUTH DAKOTA.
WEBCAMS SHOW THAT THE PRECIPITATION TOWARDS HAAKON/STANLEY
COUNTIES IS IN THE FORM OF RAIN AND WITH SURFACE TEMPERATURES IN
THAT AREA AROUND OR ABOVE FREEZING...DON/T THINK THERE IS TOO MUCH
FREEZING RAIN OCCURRING AT THIS POINT. FARTHER NORTH...RAP
ANALYSIS SOUNDINGS INDICATE THE WARM NOSE ALOFT WEAKENS WHICH
SHOULD TRANSITION THE PRECIP TO SNOW THE FARTHER NORTH YOU HEAD.
OVER THE REST OF THE AREA...CLOUDS HAVE BEEN LOWERING WITH THE
INCREASING LOW LEVEL MOISTURE AND DEPARTING SURFACE RIDGE.
TEMPERATURES ARE STILL FAIRLY COLD OVER NORTHEAST SD...WHERE 2PM
TEMPERATURES RANGE FROM THE UPPER SINGLE DIGITS AT K8D3 TO 13 AT
KABR AND THEN 17 AT KMBG.
MODELS CONTINUING TO STRUGGLE WITH THE TRACK/EVOLUTION OF THE
SHORTWAVE IN MONTANA...WHICH LEADS TO SOME UNCERTAINTY IN THE
FORECAST SNOWFALL OVER N.C./N.E. SOUTH DAKOTA THIS EVENING INTO
THE OVERNIGHT HOURS. LATEST RUNS OF THE RAP AND 12Z GLOBAL
MODELS HAVE TRENDED THE TRACK OF THE STRONGEST FORCING A LITTLE
FARTHER TO THE SOUTHWEST AND IN SOME CASES ONLY BARELY BRUSHING
SOUTHWESTERN SD. WHILE THAT BEST FORCING SLIDES SOUTHWEST OF
MUCH OF THE AREA...STILL HAVE SOME SUPPORT FROM THE UPPER TROUGH
AND ESPECIALLY FROM THE WARM AIR ADVECTION / ISENTROPIC ASCENT
ALONG AND AHEAD OF THAT TROUGH THROUGH THE EARLY OVERNIGHT
HOURS. FAIRLY STRONG LIFT WITH THE WAA (AND SEEN IN THE 700MB
OMEGA) WITH FAVORABLE 850-500MB Q-VECTOR DIVERGENCE.
THEREFORE...EXPECT TO SEE A FAIRLY QUICK HITTING (4-7HR PERIOD)
AREA OF PRECIPITATION MOVING THROUGH THE AREA...ESPECIALLY THIS
EVENING INTO THE EARLY OVERNIGHT HOURS. MODELS HAVE TRENDED QPF
AMOUNTS TO THE NORTH WITH THE MOST RECENT RUNS...SOME EVEN
SHOWING 12HR QPF AMOUNTS EXCEEDING 0.6IN BETWEEN
MOBRIDGE/ABERDEEN. THAT POTENTIAL (LIKELY SOMEWHAT CONVECTIVELY
DRIVEN WITH 750-500MB LAPSE RATES AROUND 7 C/KM) WILL NEED TO BE
WATCHED THROUGH THE EVENING AND IF IT SETS UP AS SHOWN WITH SOME
OF THE HIGHER RES RUNS...MAY NEED TO UPGRADE A FEW COUNTIES TO
WARNINGS. WITH THAT FARTHER NORTH TREND...EXPECT A LITTLE LESS
IMPACT FOR THE SOUTHWESTERN CWA...BUT STILL THINK THE POTENTIAL
FOR FREEZING RAIN THROUGH THE FIRST PART OF THE EVENING BEFORE
TRANSITIONING TO SNOW FOR A BRIEF PERIOD BEFORE ENDING. THAT
NORTHWARD SHIFT SHOULD KEEP SNOWFALL AMOUNTS BELOW 2 INCHES FROM
PIERRE AND SOUTHWEST (WHERE SOME AREAS WILL STAY MAINLY RAIN).
AS FOR SNOWFALL AMOUNTS OVER THE NORTH CENTRAL AND
NORTHEAST...HAVE A GENERAL 3-6 INCHES WITH SNOW RATIOS
INCREASING FROM AROUND 10-1 AROUND THE MISSOURI RIVER TO THE
12-14 TO 1 RANGE OVER THE NORTHEAST. OVER THE NORTHEAST...A GOOD
PORTION OF THE LIFT IS AT OR ABOVE THE DGZ...WHICH WILL LIKELY
LEAD TO MORE COLUMNS IN THE SNOW PROCESS AND MORE POTENTIAL FOR
COMPACTING (ALONG WITH AGGREGATION AS THE SNOW FALLS THROUGH THE
CLOUD LAYER BELOW THE DGZ). THUS...DIDN/T WANT TO GO MUCH HIGHER
THAN THE PREVIOUSLY MENTIONED VALUES ...ALTHOUGH RATIOS COULD
BRIEFLY INCREASE IF THE FORCING ALIGNS A LITTLE LOWER AND IN THE
DGZ. WITH THE HIGHER QPF AND RATIOS...HAVE NEAR WARNING SNOWFALL
AMOUNTS (5.5-6IN) OVER MCPHERSON/EDMUNDS/BROWN/MARSHALL/DAY
COUNTIES. WITH THE VARIABILITY IN THE MODEL RUNS TODAY...DIDN/T
HAVE ENOUGH CONFIDENCE TO UPGRADE TO A WARNING AT THIS POINT AND
THE EVENING SHIFT WILL NEED TO MONITOR FOR A POSSIBLE UPGRADE. IN
ADDITION...WITH THE SNOW OCCURRING LATE THIS EVENING AND DURING
THE EARLY OVERNIGHT HOURS...THOUGHT THE IMPACTS WOULD BE LOWER
THAN IF IT OCCURRED DURING THE DAY.
ONE OTHER ITEM TO MENTION WILL BE THE GUSTY SOUTH-SOUTHEAST
WINDS INITIALLY THIS EVENING AHEAD OF THE TROUGH (GUSTS TO
25-30MPH). THAT WILL LEAD TO PATCHY/AREAS OF BLOWING SNOW AND
WILL CONTINUE TO MENTION THAT IN THE FORECAST/WSW.
FOR THE REST OF THE PERIOD...THE SNOW WILL DIMINISH FROM WEST TO
EAST LATE TONIGHT AND THROUGH THE DAY ON SUNDAY (LARGELY OVER
THE EASTERN HALF/THIRD OF THE CWA). A BROAD SURFACE TROUGH WILL
BE OVER THE AREA AND LIMIT THE WINDS AND IN TURN ANY BLOWING SNOW
CONCERNS. IN ADDITION...WITH THE WARM AIR OVER THE
AREA BEHIND THE WARM FRONT THAT MOVED THROUGH...HIGHS WILL RISE
INTO THE MID/UPPER 20S OVER THE FAR EAST TO THE LOWER 40S ALONG
AND WEST OF THE MISSOURI RIVER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 235 PM CST SAT FEB 13 2016
LOW TEMP FORECAST FOR SUNDAY NIGHT IS A BIT TRICKY. AREA WILL STILL
BE IN A RELATIVELY MILD AIR MASS WITH 925MB TEMPS AROUND 0C TO +2C
AND A LIGHT WEST TO SOUTHWEST SFC WIND. ALTHOUGH...WILL HAVE TO KEEP
IN MIND THE FRESH COAT OF SNOW THAT WILL BE OVER MUCH OF THE AREA.
THERE WILL BE SOME DEGREE OF CLOUD COVER AS WELL...SO TRYING TO
FIGURE OUT WHICH VARIABLES HAVE THE BIGGEST IMPACT ON TEMPS IS
TRICKY.
WILL THEN BE WATCHING THE NEXT PIECE OF SHORTWAVE ENERGY WHICH WILL
BE DROPPING SOUTHEAST THROUGH THE AREA MONDAY NIGHT. HAVE INCREASED
POPS FOR THIS EVENT AS MODELS ARE IN PRETTY GOOD AGREEMENT ON TIMING
AND PLACEMENT OF QPF. AGAIN...COULD BE DEALING WITH MIXED PRECIP
ISSUES AS THERE WILL BE WARM AIR IN PLACE.
YET ANOTHER WAVE MOVES THROUGH TUESDAY NIGHT BUT IS LOOKING RATHER
WEAK AT THIS POINT. SUPERBLEND GAVE SLIGHT CHANCE POPS AND THIS
LOOKS GOOD FOR THE TIME BEING. ONLY CHANGE HERE WAS TO REMOVE THE
SLIGHT CHANCES THEY INITIAL GAVE ON TUESDAY AND HELD THINGS OFF TO
TUESDAY NIGHT PER MODEL DATA.
TEMPS THROUGHOUT THE PERIOD STAY ON THE MILD SIDE...ESPECIALLY BY
THURSDAY WHEN MODELS TRY TO BRING IN SOME VERY MILD AIR. 925MB TEMPS
AROUND +20C SHOW UP IN THE MODELS OVER SOUTHWEST AND SOUTH CENTRAL
SD. SUPERBLEND TEMPS HAVE READINGS AS WARM AS THE 60S OVER THE
SOUTHWEST CWA ON THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 557 PM CST SAT FEB 13 2016
FLIGHT CATEGORY WILL BE BOUNCING IN AND OUT OF MVFR/IFR RANGE FOR
CIGS AND VISBIES WITH FREEZING RAIN AND SNOW /PERHAPS EVEN SOME
THUNDER TOO/ PROBABLE AT THE KPIR TERMINAL NOW THROUGH MIDNIGHT.
KMBG...KABR AND KATY WILL PROBABLY JUST SEE LIGHT TO MODERATE SNOW
OVERNIGHT INTO SUNDAY MORNING. BREEZY CONDITIONS AT KMBG AND KPIR
WILL SUBSIDE WITHIN THE NEXT SEVERAL HOURS...BUT AT
KABR/KATY...THE BREEZY TO OCCASIONALLY WINDY SOUTHERLY WINDS WILL
PERSIST INTO SUNDAY MORNING BEFORE BACKING DOWN.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR SDZ009-
015-016-034-036.
WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR SDZ007-008-021.
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR SDZ003-
004-033-035-045-048-051.
WINTER WEATHER ADVISORY UNTIL 9 AM CST SUNDAY FOR SDZ005.
WINTER STORM WARNING UNTIL 9 AM CST SUNDAY FOR SDZ006-010-017-018-
037.
WINTER STORM WARNING UNTIL NOON CST SUNDAY FOR SDZ011-019-020-022-
023.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR MNZ039-046.
&&
$$
UPDATE...DORN
SHORT TERM...SRF
LONG TERM...TDK
AVIATION...DORN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
346 AM MST SUN FEB 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM MST SUN FEB 14 2016
RATHER STG WNW FLOW ALOFT WILL CONTINUE OVER NRN CO THRU TONIGHT.
MOISTURE WILL GRADUALLY INCREASE IN THE MTNS BY MIDDAY WITH BETTER
LAPSE RATES BY AFTN. THUS SHOULD SEE A GRADUAL INCREASE IN SNOW BY
AFTN WHICH WILL CONTINUE THRU THE EVENING HOURS ESPECIALLY ALONG AND
NORTH OF I-70. AFTER MIDNIGHT MOISTURE WILL DECREASE SOMEWHAT
HOWEVER WILL STILL SEE PERIODS OF LIGHTER OROGRAPHIC SNOW IN MOST
MTN AREAS. MEANWHILE GUSTY WINDS WILL PRODUCE AREAS OF BLOWING SNOW
ABV 10000 FT. WILL ISSUE AN ADVISORY FOR MTN AREAS ALONG AND NORTH
OF I-70 THIS AFTN THRU TONIGHT. PORTIONS OF ZN 31 COULD GET CLOSE
TO WARNING CRITERIA IF LATEST HRRR IS CORRECT.
AT LOWER ELEVATIONS A PACIFIC FNT WILL MOVE ACROSS THIS AFTN WITH
GUSTY NWLY WINDS DEVELOPING FM THE FOOTHILLS ACROSS THE PLAINS. WITH
STG DOWNSLOPE COMPONENT IN PLACE PCPN POTENTIAL OVER NERN CO LOOKS
TO BE RATHER LOW HOWEVER THERE WILL BE SOME MID LVL QG ASCENT
LATER THIS AFTN INTO THE EARLY EVENING HOURS SO WILL KEEP IN A
SLIGHT CHC OF SHOWERS. AS FOR HIGHS READINGS WILL BE COOLER THIS
AFTN WITH TEMPS IN THE UPPER 40S TO LOWER 50S ACROSS NERN CO.
AS FOR HIGH WIND THREAT OVERALL THERE IS NEVER REALLY MUCH OF A MTN
WAVE FOR ANY EXTENDED PERIOD OF TIME TODAY OR TONIGHT. THUS DON`T
EXPECT ANY WIDESPREAD HIGH WINDS ALTHOUGH THERE COULD BE A FEW
BRIEF HIGHER GUSTS IN THE NORMAL WINDY AREAS IN AND NR THE
FOOTHILLS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM MST SUN FEB 14 2016
MODELS HAVE STRONG NORTHWESTERLY FLOW ALOFT FOR THE FORECAST AREA
MONDAY THROUGH TUESDAY NIGHT. JET LEVEL SPEEDS ARE 80 TO 110
KNOTS ALL FOUR PERIODS. THE QG VERTICAL VELOCITY FIELDS HAVE WEAK
DOWNWARD SYNOPTIC SCALE ENERGY FOR THE CWA ALL FOUR PERIODS. THE
BOUNDARY LAYER FLOW LOOKS TO BE DOMINATED BY DOWNSLOPING THROUGH
TUESDAY NIGHT. FOR MOISTURE...THERE IS SOME PROGGED OVER THE HIGH
MOUNTAINS MONDAY INTO MONDAY EVENING...THEN IT DECREASES. THERE IS
SOME OVER THE PLAINS...MOSTLY IN THE UPPER AND MID LEVELS MONDAY.
TUESDAY AND TUESDAY NIGHT ARE PRETTY DRY IN ALL AREAS. THE QPF
FIELDS SHOWS LIMITED SNOWFALL IN THE HIGH MOUNTAINS MONDAY AND
MONDAY NIGHT. FOR POPS...NOTHING FOR THE PLAINS...TO DRY AND
DOWNSLOPING. FOR THE MOUNTAINS...THERE IS SOME MOISTURE MONDAY AND
MONDAY NIGHT AS WELL AS HELP WITH OROGRAPHICS...HOWEVER...
MOISTURE DECREASES SLOWLY THROUGH THOSE TWO PERIODS...THERE IS
SLIGHT WARM AIR ADVECTION...AND NO HELP FROM SYNOPTIC SCALE LIFT.
CURRENT GFE GRIDS HAVE 50-80% POPS IN THE HIGH MOUNTAINS MONDAY
AND MONDAY NIGHT...THIS LOOK REASONABLE. SNOWFALL AMOUNTS WILL BE
HIGHEST IN ZONE 31...BUT HIGHLIGHT CRITERIA AMOUNTS ARE UNLIKELY.
FOR TEMPERATURES...MONDAY`S HIGHS ARE 1-3 C WARMER THAN TODAY`S.
TUESDAY HIGHS ARE 1-2 C WARMER THAN MONDAY`S. FOR THE LATER DAYS
...WEDNESDAY THROUGH SATURDAY...AN UPPER RIDGE MOVES ACROSS
WEDNESDAY INTO EARLY THURSDAY. A WEAK UPPER TROUGH THEN PUSHES
THROUGH BY FRIDAY MORNING. FLAT UPPER RIDGE RETURNS THROUGH EARLY
SATURDAY. ZONAL FLOW IS PROGGED DON SATURDAY. THERE MAY BE ENOUGH
ENERGY AND MOISTURE FOR LIMITED MOUNTAIN POPS THURSDAY AFTERNOON
INTO EARLY FRIDAY. TEMPERATURES WILL STAY ABOVE SEASONAL NORMALS
ALL FOUR DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 335 AM MST SUN FEB 14 2016
WINDS EARLY THIS MORNING HAVE BECOME SLY. BY 16Z THEY MAY BECOME
MORE WLY AND THEN GRADUALLY SHIFT TO A MORE WNW DIRECTION BY EARLY
AFTN. LATEST HRRR INDICATES SOME GUSTS FM 30 TO 35 MPH MAY OCCUR FM
20Z TO AROUND 00Z. BY EARLY EVENING WINDS WILL BECOME MORE WSW AND
THEN SSW BY 06Z. AS FOR CLOUD COVER MAY SEE CEILINGS BRIEFLY DROP
DOWN TO 8000 FT LATE THIS AFTN INTO EARLY EVENING AS A FAST MOVING
DISTURBANCE MOVES ACROSS WHICH MAY PRODUCE VIRGA OR A FEW SPRINKLES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM MST MONDAY FOR
COZ034.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 5 PM MST MONDAY FOR
COZ031-033.
&&
$$
SHORT TERM...RPK
LONG TERM...RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
829 AM EST SUN FEB 14 2016
.UPDATE...
A COASTAL TROUGH IS EXPECTED TO DEVELOP THIS AFTERNOON. MODELS
DIVERGE WITH THIS FEATURE. NAM DEPICTS A LOW DEVELOPING IN THE
TROUGH...WITH BETTER RAIN CHANCES...WHEREAS GFS AND HRRR DEPICT A
MUCH WEAKER TROUGH WITH RAIN LARGELY STAYING OVER THE WATERS. THUS
FAR NAM IS TOO STRONG WITH TROUGH AS COMPARED TO OBSERVED...SO WILL
BE TRENDING TOWARD HRRR WITH UPDATE.
&&
.AVIATION...
PREVAILING VFR CONDITIONS ARE EXPECTED THIS MORNING. STRATUS IS
EXPECTED TO DEVELOP OVER THE COASTAL WATERS AND MOVE ASHORE THIS
AFTERNOON. AS A RESULT MVFR CIGS ARE EXPECTED OVER COASTAL TAF
SITES LATE THIS AFTERNOON INTO TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 57 42 69 54 / 0 10 30 70
SSI 54 44 64 57 / 10 20 20 70
JAX 61 46 72 59 / 20 10 20 70
SGJ 60 53 72 59 / 20 20 20 70
GNV 66 47 76 57 / 0 0 10 70
OCF 68 51 77 59 / 0 0 10 60
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
STRUBLE
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
505 AM CST SUN FEB 14 2016
.SHORT TERM...(Today)
ISSUED AT 324 AM CST SUN FEB 14 2016
08z/2am water vapor imagery shows a vigorous short-wave trough over
eastern Nebraska. A narrow band of snow has developed well in
advance of this feature across the central sections of Iowa and
Illinois in association with strong 700-500mb layer frontogenesis.
Latest radar imagery/surface obs show the snow band centered along a
Galesburg...to Lincoln...to Marshall line. This band is expected to
gradually lift northward over the next few hours, as frontogenetic
forcing shifts northward and weakens. Snowfall of one half inch or
less will be likely with this initial burst of snow early this
morning. The main precip event will hold off until later this
morning as stronger/more widespread synoptic lift associated with
the short-wave arrives. HRRR seems to be handling the current
precip field better than any other model, so have followed its
solution closely in the short-term. It shows snow rapidly
developing in advance of the approaching wave and spreading eastward
into central Illinois between 15z and 18z. Based on speed of wave,
a 4-5 hour period of light to moderate snow is expected from late
morning through mid-afternoon before the precip begins to diminish
from west to east late in the day. Total snowfall still appears to
be 2-3 inches across most areas, with the highest totals of 4-5
inches focused along/northwest of the Illinois River. Will continue
the Winter Weather Advisory through 6pm accordingly.
.LONG TERM...(Tonight through Saturday)
ISSUED AT 324 AM CST SUN FEB 14 2016
All models show the strongest lift quickly shifting east of the area
late this afternoon into the early evening, suggesting a rapid end
to the accumulating snow. Will linger chance PoPs across the north
and east through the evening, then will go dry across the board
overnight. Forecast soundings show a loss of ice crystals within
the profile, resulting in a period of light freezing drizzle as the
precip ends.
Monday still appears to be a cool and mostly dry day: however, a few
of the models are showing some light precip with another short-wave
skirting through the area. The GFS is the most bullish with precip,
while the NAM and ECMWF show very little. Given presence of at
least weak lift, will carry slight chance PoPs for rain/snow across
the southern half of the KILX CWA Monday afternoon.
A more significant wave will push into the region on Tuesday,
bringing another round of light precip. Models generally track the
500mb vort max right across central Illinois, resulting in most of
the precip being focused across the northern half of Illinois.
Thermal profiles will be cold enough to support snow initially late
Monday night into Tuesday morning: however, as temperatures climb
into the upper 30s and lower 40s, the snow will transition to a
rain/snow mix or all rain by Tuesday afternoon. Minor snow
accumulations of 1 inch or less are expected during the morning
before the snow mixes with/changes to rain.
After that, the big weather story for the end of the week will be a
pronounced warming trend as upper-level ridging builds across the
Midwest. High temperatures will reach the upper 40s and lower 50s
on Thursday, then will climb even higher into the upper 50s and
lower 60s by Friday. A weak cold front will push through Illinois
on Friday, with 00z Feb 14 models now pulling back on their QPF.
Will still mention low chance PoPs for rain showers with FROPA on
Friday, followed by a return to mild/dry weather next weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 500 AM CST SUN FEB 14 2016
First wave of snow was pushing into our eastern TAF sites this
morning with a break in the snow through about 15z before another
round of snow and IFR cigs moves in for the rest of the day.
Latest surface observations to our west indicates cigs improve
to low VFR with occasional MVFR cigs/vsbys in very light snow.
However, across western Iowa into northwest Missouri, a band
of light to moderate snow was located and based on the present
movement of the snow, it will push into our western areas between
14z-16z, and over the far eastern TAF sites by 18z. Cigs and Vsbys
will lower to IFR to occasional VLIFR where some of the heavier
bands of snow setup. The snow is expected to taper to flurries
by late afternoon or early this evening and as the precip starts
to edge off to our east, there is the threat for some patchy
freezing drizzle this evening, mainly from 00z-06z. Due to the
patchy nature of the precip this evening, will not include in
the TAFs at this time, but something to keep an eye on with
later forecasts today.
Southeast winds of 12 to 17 kts are expected today with a few
gusts around 23 kts into this afternoon with winds turning
more into a southerly direction tonight with speeds of 10 kts
or less.
&&
.ILX Watches/Warnings/Advisories...
Winter Weather Advisory until 6 PM CST this evening for
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1051 AM EST SUN FEB 14 2016
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 1040 AM EST SUN FEB 14 2016
CENTRAL INDIANA WILL BE UNDER AN ACTIVE WEATHER PATTERN THROUGH
NEXT WEEK AS A SERIES OF DISTURBANCES MOVE THROUGH THE REGION. THE
FIRST WILL START IMPACTING THE AREA THIS MORNING...RESULTING IN 1 TO
4 INCHES OF SNOWFALL BY TONIGHT ACROSS CENTRAL INDIANA. THE SECOND
DISTURBANCE WILL PASS THROUGH ON MONDAY...BUT RAIN MIXING IN WILL
LIMIT SNOW ACCUMULATIONS. YET ANOTHER SYSTEM WILL BRING MIXED
PRECIPITATION ON TUESDAY. FURTHER OUT...A WARM UP CAN BE EXPECTED
DURING THE EXTENDED PERIOD WITH RAIN CHANCES ON FRIDAY.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1034 AM EST SUN FEB 14 2016
CURRENTLY SEEING A LULL IN ACCUMULATING SNOWFALL ACROSS CENTRAL
INDIANA. A RELATIVELY DRY COLUMN HAS KEPT MOST OF THE SNOW THAT
FELL EARLIER THIS MORNING FROM ACCUMULATING EXCEPT IN THE HEAVIEST
BAND WHERE UP TO HALF AN INCH WAS REPORTED. A COMPACT UPPER WAVE
SEEN IN SATELLITE IMAGERY OVER IOWA WILL CONTINUE TO MOVE TOWARD
THE AREA TODAY AND ISENTROPIC LIFT WILL INCREASE FROM THE
SOUTH. RADAR TRENDS AND HI RES GUIDANCE INDICATE ACCUMULATING SNOW
WILL MOVE BACK INTO WESTERN INDIANA STARTING AROUND NOON AND
OVERSPREAD THE AREA FROM THERE. THE LAST FEW RUNS OF BOTH THE RAP
AND HRRR CONTINUE TO INDICATE THE HEAVIEST SNOW WILL FALL ACROSS
THE SOUTHERN COUNTIES AND THEY SHOW A DECENT SWATH OF 2-3 INCHES
FROM AROUND I-70 SOUTH WITH 3-4 INCHES SOUTH OF A BLOOMINGTON TO
COLUMBUS LINE AND PERHAPS EVEN ISOLATED 5 INCH AMOUNTS. BASED ON
THIS HAVE UPPED SNOWFALL AMOUNTS TO 1 TO 3 INCHES IN THE
NORTHEAST...2 TO 3 CENTRAL AND 3 TO 4 SOUTH WITH ISOLATED HIGHER
AMOUNTS. RAP AND HRRR BOTH SHOW HEAVIEST SNOW STARTING AROUND 2-3
PM AND MOVING OUT OF THE AREA BY AROUND 6 PM...BUT HAVE GIVEN THIS
A BIT OF CUSHION ON EITHER SIDE IN THE TIMING IN THE WSW. MADE NO
ADJUSTMENTS TO THE AREAL EXTENT OF THE ADVISORY BUT DID BUMP UP
AMOUNTS AND ADDED TIMING OF HEAVIEST SNOW.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 334 AM EST SUN FEB 14 2016
THE MAIN FOCUS OF THE SHORT TERM PERIOD WILL BE THE REMNANTS OF
THE FIRST SYSTEM FOLLOWED BY ANOTHER DISTURBANCE ON TUESDAY.
ISENTROPIC LIFT ABRUPTLY CUTS OFF ACROSS CENTRAL INDIANA AFTER MON
03Z AS MOISTURE DECREASES. SO...RAPIDLY DECREASED POPS FROM WEST
TO EAST AFTER SUN 06Z WITH JUST A FEW ADDITIONAL TENTHS OF AN INCH
OF SNOW ACCUMULATION OVERNIGHT.
FOCUS THEN TURNS TO THE NEXT UPPER WAVE PROGGED TO MOVE THROUGH ON
MONDAY EVENING. EXPECT A LULL IN ACTIVITY ON MONDAY AFTERNOON WITH
JUST A BRIEF SPIKE IN PRECIPITATION ON MONDAY EVENING AS THAT
UPPER WAVE MOVES THROUGH...BUT MOISTURE APPEARS LIMITED. SO...WILL
ONLY GO WITH SLIGHT CHANCE POPS FOR MONDAY EVENING AND NIGHT.
FINALLY...A THIRD DISTURBANCE WILL TRACK ACROSS THE AREA ON
TUESDAY. THIS WILL BE MORE OF A MIXED PRECIPITATION EVENT THOUGH
AS TEMPERATURES TOP OFF IN THE UPPER 30S/LOW 40S ON TUESDAY
AFTERNOON. AS COOLER AIR MOVES IN ON TUESDAY NIGHT...THE NORTHERN
HALF OF CENTRAL INDIANA WILL SEE A TURN OVER TO SNOW...WHILE
SOUTHERN PORTIONS CAN EXPECT A RAIN/SNOW MIX. DURING THE DAY ON
TUESDAY...NORTHERN PORTIONS WILL SEE A RAIN/SNOW MIX...WHILE THE
SOUTHERN COUNTIES WILL RECEIVE MAINLY RAIN.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY|/...
ISSUED AT 309 AM EST SUN FEB 14 2016
PRIMARY FOCUS THROUGH THE EXTENDED PERIOD WILL BE A FEBRUARY THAW
AS THE BROAD UPPER RIDGE OVER THE WESTERN PART OF THE COUNTRY
FINALLY SHIFTS EAST. TEMPERATURES WILL SURGE TO ABOVE NORMAL
LEVELS BY FRIDAY AND CONTINUING INTO THE WEEKEND.
THE OHIO VALLEY WILL REMAIN IN A COOL CYCLONIC FLOW ALOFT ON
WEDNESDAY AS THE UPPER TROUGH SLOWLY SHIFTS AWAY TO THE EAST . NOT
OUT OF THE QUESTION TO SEE LINGERING FLURRIES OR VERY LIGHT SNOW
SHOWERS IN THIS SETUP...BUT WILL LEAVE DRY AT THIS TIME WITH
SURFACE HIGH PRESSURE ASSERTING ITS INFLUENCE BY LATE DAY.
THE HIGH WILL SHIFT ACROSS THE GREAT LAKES AND INTO NEW ENGLAND
BY EARLY FRIDAY. AT THE SAME TIME...STRONG LOW PRESSURE WILL
DEVELOP OVER THE NORTHERN PLAINS THEN MOVE EAST INTO THE GREAT
LAKES BY FRIDAY. A STRONG S/SW FLOW WILL DEVELOP BETWEEN THE HIGH
TO THE EAST AND THE LOW TO THE NORTHWEST...RESULTING IN WINDY
CONDITIONS ON FRIDAY AND MUCH WARMER TEMPERATURES AS STRONG WARM
ADVECTION DEVELOPS AHEAD OF THE ASSOCIATED COLD FRONT. SCATTERED
RAIN SHOWERS WILL ACCOMPANY THE PASSAGE OF THE COLD FRONT LATE
FRIDAY. DRY WEATHER WILL RETURN ON SATURDAY WITH HIGH PRESSURE
BEFORE ANOTHER SYSTEM BRINGS PRECIP FOR LATE WEEKEND.
HIGHS WILL RISE INTO THE 50S TO NEAR 60 BY FRIDAY...REMAINING
ABOVE NORMAL IN THE UPPER 40S TO MID 50S OVER THE WEEKEND.
&&
.AVIATION /DISCUSSION FOR 141500Z KIND TAF UPDATE/...
ISSUED AT 924 AM EST SUN FEB 14 2016
IMPROVED VISIBILITIES THROUGH AROUND 17Z TO BETTER MATCH
CURRENT CONDITIONS. NO OTHER CHANGES ARE NEEDED AT THIS TIME.
PREVIOUS AVIATION DISCUSSION FOLLOWS...
POOR FLYING CONDITIONS DEVELOPING IN SNOW...ESPECIALLY THIS
AFTERNOON AND EVENING.
MOISTURE STEADILY EXPANDING INTO CENTRAL INDIANA EARLY THIS
MORNING BUT SOUNDINGS SHOW DRY AIR REMAINS WITHIN THE BOUNDARY
LAYER. AS LIFT STRENGTHENS THROUGH THE MORNING IT WILL AID LOW
LEVEL SATURATION WITH LIGHT SNOW DEVELOPING ACROSS THE TERMINALS.
ANY RESTRICTIONS SHOULD REMAIN IN THE MVFR CATEGORY THIS
MORNING...ALTHOUGH BOTH KBMG AND KHUF MAY SEE BRIEF DROPS IN SNOW
TO IFR.
MUCH STRONGER ISENTROPIC LIFT WILL ARRIVE BY EARLY AFTERNOON IN
ADVANCE OF A VIGOROUS WAVE ALOFT. COMBINED WITH FRONTOGENETICAL
FORCING IN THE MID LEVELS...EXPECT A 3 TO 6 HOUR PERIOD WITH
MODERATE TO OCCASIONALLY HEAVY SNOW FROM THE AFTERNOON INTO THE
EVENING WITH LIFR AND LOWER CONDITIONS EXPECTED. HI-RES GUIDANCE
SHIFTS THE BAND OF WIDESPREAD HEAVIER SNOW TO OUR EAST DURING THE
EVENING BUT PRESENCE OF FORCING IN THE MID LEVELS COURTESY OF THE
WAVE ALOFT SHOULD ENABLE SCATTERED SNOW SHOWERS INTO THE
OVERNIGHT WITH PERIODIC IFR RESTRICTIONS. SNOW SHOWERS ARE LIKELY
TO DIMINISH IN THE PREDAWN HOURS BUT MVFR STRATUS WILL LINGER
THROUGH THE END OF THE FORECAST PERIOD.
SOUTHEAST WINDS AT 10 TO 15KTS THROUGH THE DAY WILL GRADUALLY VEER
TO SOUTHERLY OVERNIGHT AND DIMINISH AFTER MIDNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR INZ028-
029-035>037-043>047-051>056-060>065-067>072.
&&
$$
SYNOPSIS...TDUD/CP
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....RYAN
AVIATION...RYAN/JH
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
913 AM CST SUN FEB 14 2016
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 912 AM CST SUN FEB 14 2016
WV imagery indicates a weak upper level shortwave trough sliding
southeast across the Central Plains. Meanwhile, a secondary upper
level shortwave is moving southeast out of the Northern Rockies
of western Montana. Near the surface, a weak area of high pressure
is moving slowly southeast across eastern Colorado.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 222 AM CST SUN FEB 14 2016
Cold front moving through the area early this morning bumping winds
briefly behind the boundary to gusts in the 20 knots range
locally. The larger observation picture and local GFS MOS
guidance suggests winds will quickly become lighter and westerly
this morning. Stratus will be mainly confined to the extreme
south central counties and based on the HRRR is likely to exit by
11 or 12 UTC. The consensus of most of the models data for this
afternoon points toward highs in the mid to upper 50s; perhaps
pushing 60 degrees along the Oklahoma line. However the model
variance is quite low lending to better confidence. Light winds
and cloudy skies are likely tonight as a secondary shortwave seen
for several runs now, rotates through the region. The GFS is the
only model producing any measurable QPF while others strongly
suggestive of a completely dry passage. The models are a few
degrees warmer than most MOS solutions.
.LONG TERM...(Monday THROUGH Saturday)
ISSUED AT 222 AM CST SUN FEB 14 2016
The remainder of the week is a story of a strong warming trend,
incrementally each day, to highs likely in the upper 70s and low
80s by Thursday. With such warm temperatures by Thursday,
critical fire weather may become a concern if gusts are
sufficient in the afternoon.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Monday MORNING)
ISSUED AT 529 AM CST SUN FEB 14 2016
Winds will be northwesterly at around 10 knots this morning but will
become light and variable as the day progresses. A weak upper disturbance
moving over the region tonight could bring a few sprinkles or flurries
but cigs should remain VFR. By very late in the period, winds will become
northwesterly again and could increase into the 10-15 knot range.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 56 32 61 37 / 10 10 0 0
GCK 57 31 63 35 / 10 10 0 0
EHA 58 33 65 37 / 0 10 0 0
LBL 58 32 65 35 / 0 10 0 0
HYS 53 32 57 36 / 10 10 0 0
P28 59 34 64 38 / 10 10 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Gerard
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
530 AM CST SUN FEB 14 2016
...Updated aviation discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 222 AM CST SUN FEB 14 2016
Cold front moving through the area early this morning bumping winds
briefly behind the boundary to gusts in the 20 knots range
locally. The larger observation picture and local GFS MOS
guidance suggests winds will quickly become lighter and westerly
this morning. Stratus will be mainly confined to the extreme
south central counties and based on the HRRR is likely to exit by
11 or 12 UTC. The consensus of most of the models data for this
afternoon points toward highs in the mid to upper 50s; perhaps
pushing 60 degrees along the Oklahoma line. However the model
variance is quite low lending to better confidence. Light winds
and cloudy skies are likely tonight as a secondary shortwave seen
for several runs now, rotates through the region. The GFS is the
only model producing any measurable QPF while others strongly
suggestive of a completely dry passage. The models are a few
degrees warmer than most MOS solutions.
.LONG TERM...(Monday THROUGH Saturday)
ISSUED AT 222 AM CST SUN FEB 14 2016
The remainder of the week is a story of a strong warming trend,
incrementally each day, to highs likely in the upper 70s and low
80s by Thursday. With such warm temperatures by Thursday,
critical fire weather may become a concern if gusts are
sufficient in the afternoon.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Monday MORNING)
ISSUED AT 529 AM CST SUN FEB 14 2016
Winds will be northwesterly at around 10 knots this morning but will
become light and variable as the day progresses. A weak upper disturbance
moving over the region tonight could bring a few sprinkles or flurries
but cigs should remain VFR. By very late in the period, winds will become
northwesterly again and could increase into the 10-15 knot range.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 56 32 61 37 / 10 10 0 0
GCK 57 31 63 35 / 10 10 0 0
EHA 58 33 65 37 / 0 0 0 0
LBL 58 32 65 35 / 0 0 0 0
HYS 53 32 57 36 / 10 10 0 10
P28 59 34 64 38 / 10 10 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Gerard
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
511 AM CST SUN FEB 14 2016
.UPDATE...
Issued at 511 AM CST SUN FEB 14 2016
The latest RAP and NAM isentropic progs continue to show the
better saturation and lift focusing to the east of the forecast
area. With the HRRR handling the shower activity earlier and
taking it out of the area, have reasonable confidence that precip
is pretty much over. Will be sending out an update to the forecast
to reflect this.
&&
.SHORT TERM...(Today and Tonight)
Issued at 324 AM CST SUN FEB 14 2016
08Z water vapor imagery shows a shortwave moving east across NEB and
SD and a weaker wave across AZ and NM. There also appears to be a
shortwave over British Columbia moving towards ID and MT. Surface
observations show a general trough of low pressure across the Great
Plains from west TX to the Canadian boarder as the arctic high
pressure system continues to move east. Locally, surface winds have
generally remained from the east with shallow dry air remaining over
the forecast area noted by the dewpoints still in the single digits.
For today, models show the best forcing and isentropic upglide
occurring now with the shortwave just north of the forecast area.
Once it passes to the east, the warm air advection pattern becomes
focused to the east of the forecast area and should bring an end to
precip chances for the rest of the day. Radar is starting to show
some shower activity developing over eastern KS similar to the HRRR.
RAP forecast soundings hint at some weak elevated instability but
the low level moisture has been slow to move into east central KS.
Will increase chances for precip and mention freezing rain in the
forecast. This activity should be short lived and be moving east of
the area by 8am. Think there should be some sunshine by the
afternoon behind the shortwave. So with some insolation and warm air
moving in from the west, high are forecast to be around 50 to the
mid 50s.
Tonight models show another low amplitude wave moving across the
forecast area with the GFS most aggressive in generating a couple
hundredths of precip. Model progs of forcing are rather disorganized
and continue to show deep layer moisture lacking. Because of this
think any precip is likely to remain a trace event. Precip type is
somewhat uncertain in that both the GFS and NAM forecast soundings
show a decent warm nose of +3 to +5 C. So snow is unlikely, and with
the dry air in place within low levels of the atmosphere and a
westerly wind this afternoon and evening unlikely to advect low
level moisture into the area, drizzle does not look much more
likely. The GFS would suggest temps are warm enough for any precip
to be liquid. Meanwhile the NAM has surface temps around freezing
but a lot more dry air to overcome. Think the NAM is probably
handling the thermal profile within the boundary layer better than
the GFS so have lows in the lower 30s for tonight. As for precip
type, will stick with sprinkles which possible could freeze on
elevated surfaces if there is not to much low level dry air.
.LONG TERM...(Monday through Saturday)
Issued at 324 AM CST SUN FEB 14 2016
Another shortwave in the northwest flow aloft is forecasted to track
over the area Monday morning, but should be mostly dry. The next in
the parade of shortwaves will pass over the area Tuesday morning,
and like the previous waves will lack any appreciable low level
moisture. Also, the better mid level moisture will be centered over
IA. There is a chance there may be enough precipitation falling into
this dry layer for rain to reach the surface. The better chances for
this light rain will be mainly over far northeast KS, and amounts
look to be rather minor. Luckily there is a deep enough layer of
above freezing temperatures even after saturation therefore frozen
precipitation should not be an issue. Beyond that an upper ridge
will build eastward over the central US causing temperatures to warm
well above normal. By Thursday the guidance shows highs around 70,
but given the models tendencies to underestimate these situations
have increased the highs by a few degrees. There will be some
concern for elevated fire danger on Thursday and Friday given the
warm temperatures and gusty winds.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday Morning)
Issued at 511 AM CST SUN FEB 14 2016
Models continue to trend drier in the low levels and with forcing
for precip diminishing, VFR conditions should prevail through
tonight.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Wolters
LONG TERM...Sanders
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
625 AM EST SUN FEB 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM EST SUN FEB 14 2016
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF OVER
SE CANADA SLOWLY WEAKENING AND ALLOWING A SHRTWV RDG AXIS WITH 12HR
H5 HGT RISES UP TO 100M TO BRING LARGER SCALE SUBSIDENCE TO THE CWA.
SOME LK CLDS/LIGHT LES IS STILL LINGERING OVER THE TIP OF THE
KEWEENAW AND IN THE SN BELTS E OF MUNISING UNDER AREA OF H85 TEMPS
AOB -20C/LLVL NW FLOW...BUT SUBSIDENCE HAS HAD A SGNFT IMPACT ON
LIMITING THE INTENSITY OF THIS PCPN. ELSEWHERE SKIES HAVE CLEARED.
UNDER THE MOCLR SKIES ACRS THE W AND CENTRAL/PWAT NEAR 0.05 INCH OR
30 PCT OF NORMAL/LGT WINDS ASSOCIATED WITH SFC HI PRES PASSING THRU
WI...TEMPS AT SOME OF THE INTERIOR COLD SPOTS IN THAT AREA HAVE
FALLEN WELL BLO -20F. LOOKING TO THE W...THERE ARE TWO SHRTWVS OF
INTEREST. THE STRONGEST IS SLIDING ESEWD THRU THE DAKOTAS...WHILE
THE OTHER DISTURBANCE IS MOVING E INTO FAR SRN MANITOBA. DESPITE
VERY DRY LLVL AIR DEPICTED ON THE 00Z MPX RAOB... SOME LO/MID CLDS
AHEAD OF THESE SHRTWVS ARE PUSHING E THRU MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON CLD/POP TRENDS THIS
AFTN/TNGT ASSOCIATED WITH DISTURBANCES TO THE W AND INCRSG SLY FLOW/
WAA UNDER TIGHTENING PRES GRADIENT AS THE WI HI PRES SHIFTS TO THE
E. BIGGEST CONCERN IS POTENTIAL FOR SOME LES OFF LK MI WITH THE
INCRSG S WIND.
TODAY...STRONGER SRN MOST SHRTWV TO THE W IS FCST TO SLIDE TOWARD
THE LOWER LKS. SINCE ACCOMPANYING DPVA/DEEP LYR QVECTOR CNVGC IS
PROGGED TO STAY TO THE S OF UPR MI...MODELS SHOW VERY DRY MID LVL
AIR LINGERING OVER UPR MI. SOME MID LVL MSTR IS FCST TO MOVE INTO
THE WRN CWA LATER TODAY AHEAD OF THE WEAKER NRN DISTURBANCE...WHICH
IS FCST TO REACH NEAR INL BY 00Z MON. BUT DOWNSLOPE NATURE OF INCRSG
S WIND UNDER TIGHTENING PRES GRADIENT BTWN HI PRES SHIFTING TOWARD
THE MID ATLANTIC AND FALLING MSLP IN MN SHOULD KEEP THE W PCPN FREE
DESPITE THE INCRSG MID CLDS. THE SHORTER TIME GUIDANCE IS IN GOOD
AGREEMENT ON GENERATING SOME LGT LES OFF LK MI BY 18Z WITH SSE SFC-
H925 FLOW FLOWING UP THE LONG AXIS OF LK MI. WHILE THE ORIENTATION
OF THE FLOW UP LK MI AND H85 TEMPS REBOUNDING ONLY TO ARND -15C ARE
FAVORABLE...THE DRYNESS OF THE AIRMASS IN PLACE PER THE 00Z GRB RAOB
AS WELL ACYC NATURE OF THE H925 FLOW/LO INVRN BASE NEAR 4K FT AGL
AWAY FM DYNAMIC FORCING ASSOCIATED WITH TWO SHRTWVS TO THE W SHOULD
LIMIT COVERAGE OF SN SHOWERS/POPS AND ESPECIALLY SN TOTALS. WHILE A
FEW PLACES COULD PICK UP AN INCH OF SN...MOST LOCATIONS SHOULD SEE
LESS. INCRSG SUN ANGLE/A GOOD DEAL OF SUNSHINE AWAY FM THE LK CLDS
STREAMING OFF LK MI AND AHEAD OF DEEPER MID LVL MSTR MOVING IN FM
THE W SHOULD ALLOW VERY LO TEMPS THIS MRNG TO RECOVER CLOSER TO
NORMAL THIS AFTN.
TNGT...ARRIVAL OF SOME DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF NRN
SHRTWV TNGT IN THE PRESENCE OF PERSISTENT SLY FLOW UP THE LONG AXIS
OF LK MI AND H85 TEMPS FCST TO REMAIN AS LO AS ABOUT -13C OVER NRN
LK MI THRU 12Z MON WL ALLOW FOR SOME LK ENHANCEMENT OF THE LES IN
THE 06Z-12Z TIME TNGT. MODELS SHOW SOME SHARPER LLVL CNVGC IMPACTING
PORTIONS OF THE SE CWA AS FAR E AS THE GARDEN PENINSULA BY 12Z.
CONSIDERING THE FAVORABLE DEPTH OF THE DGZ AFTER THE ARRIVAL OF THE
DEEPER MSTR...SUSPECT SN FALL RATES COULD REACH 1-2 INCHES PER HR
UNDER THIS AXIS OF CNVGC. ALTHOUGH A GOOD NUMBER OF THE HI RES
MODELS INDICATE THIS AXIS OF LLVL CNVGC WL BE RATHER TRANSIENT...
SOME DO SHOW A SLOWER DRIFT THAT COULD RESULT IN SOME ADVY SN
TOTALS. AWAY FM THE LK MI ENHANCEMENT...ANY SN WL BE LGT...
ESPECIALLY IN AREAS OVER THE W/NW NEAR LK SUP WHERE THE S WIND WL
DOWNSLOPE. LO TEMPS TNGT WL BE MUCH WARMER THAN THIS MRNG WITH
INCRSG MSTR/STEADY SSW FLOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 442 AM EST SUN FEB 14 2016
...ACTIVE PATTERN WITH WINTRY MIX POSSIBLE LATE THIS WEEK...
IN THE LARGE SCALE...ENERGETIC PACIFIC JET STREAM WILL LEAD TO
ACTIVE AMPLIFIED FLOW AND CHANGEABLE WEATHER PATTERN NEXT 7-10 DAYS
ACROSS NORTH AMERICA. MAIN CHANCE OF WIDESPREAD LGT SNOW OCCURS MON
WITH LAKE ENHANCED SNOW POSSIBLE IN AREAS DOWNWIND OF LK MICHIGAN.
BETTER CHANCES OF LAKE EFFECT OFF LK SUPERIOR OCCUR TUE AFTN THROUGH
WED AS MORE COLD AIR SWEEPS OVER GREAT LAKES. NEXT STRONGER SYSTEM
WITH WARM AIR ADVECTION ARRIVES IN SOME SHAPE OR FORM THU/FRI.
WARMING ALOFT WILL LEAD TO LIQUID PRECIP AT SOME POINT THU NIGHT INTO
FRI...BUT THAT MAY BE PRECEEDED BY WIDESPREAD LIGHT TO MODERATE SNOW.
EXTENT OF PRECIP WITH THE SYSTEM IS UNKNOWN THOUGH AS MODELS DIFFER
ON WHERE STRONGEST SFC LOW AND LIFT FOR PRECIP DEVELOPS. PLENTY OF
TIME TO SORT OUT THESE DETAILS. NO MATTER HOW YOU LOOK AT IT APPEARS
A MESSY MIX OF WINTRY WEATHER WOULD OCCUR THU NIGHT INTO FRI.
ON MON...DEEP TROUGHING ALOFT FM THIS WEEKEND WILL BE GONE...BUT
SHORTWAVE TROUGH WILL BE ON ITS WAY TO RE-SHARPENING TROUGHING INTO
TUE. SHORTWAVE AND SFC LOW ON LEADING EDGE OF TROUGHING WILL HELP IN
SPREADING WIDESPREAD LGT SNOW ACROSS CWA. CONVERGENT SRLY FLOW OFF
LK MICHIGAN AND SUFFICIENT OVER-WATER INSTABILITY WITH H85 TEMPS
AROUND -13C OPENS DOOR FOR LAKE ENHANCEMENT MON MORNING INTO EARLY
MON AFTN. MAJORITY OF HIGH RES QPF INDICATES NARROW BAND/S OF LAKE
EFFECT WITH POSSIBILITY OF SNOW RATES OVER 1 INCH PER HOUR HELPED
OUT BY DEEP DGZ OVER 10KFT. MOST GUIDANCE ALSO SHOWS SUCH BANDS
SHIFTING ALONG AND NOT STAYING PUT OVER ONE LOCATION. AREA MOST
FAVORED FOR LAKE ENHANCEMENT AND A FEW INCHES OF SNOW WOULD BE
MENOMINEE COUNTY INTO SOUTHERN DELTA AND SOUTHERN SCHOOLCRAFT
COUNTIES. STILL TOO EARLY TO DO ANY TYPE OF HEADLINE SINCE IT IS
UNDERTAIN WHERE HEAVIER LAKE ENHANCED SNOW OCCURS...BUT MAY NEED A
HEADLINE EVENTUALLY. WILL MENTION HEAVIER SNOW POSSIBILITY IN THE
HAZARDOUS WEATHER OUTLOOK.
GENERALLY QUIET MON NIGHT INTO TUE MORNING AHEAD OF STRONGER
SHORTWAVE AND SFC LOW/TROUGH DROPPING ACROSS MANTIOBA/ONTARIO.
SOUNDINGS SHOW LOW-LEVEL MOISTURE WITH TEMPS WARMER THAN -8C SO
COULD SEE FZDZ POSSIBLE...ESPECIALLY WEST CLOSER TO APPROACHING SFC
TROUGH. MAIN IMPACT OF LOW-LEVEL MOISTURE/CLOUDS WILL BE TO HELP
KEEP TEMPS IN THE MID TEENS TO LOWER 20S. A FAR CRY FM THE BITTER
COLD OCCURRING THIS MORNING. WENT TOWARD WARMER GUIDANCE ON TUE AS
IF TROUGH SLOWS SOME ON TUE...WOULD HAVE OPPORTUNITY FOR TEMPS TO
REACH LOW-MID 30S. TROUGH ARRIVES IN THE AFTN NORTHWEST THEN SWEEPS
OVER REST OF CWA BY EVENING. A BURST OF MODERATE TO HEAVY SNOW ON
TROUGH AXIS SEEMS REASONABLE. THOUGH THIS WOULD BE BRIEF...ITS
ARRIVAL MAY TIME OUT WITH AFTN/EVENING COMMUTE. WILL BE SOMETHING
TO KEEP AWARE OF. LAKE EFFECT IN THE WAKE OF THE TROUGH SHOULD BE
OKAY TO START BUT AS LARGE HIGH PRESSURE QUICKLY BUILDS IN...EXPECT
IT TO BEGIN TO STRUGGLE. SOUNDINGS SHOW QUICKLY DEVELOPING
SUBSIDENCE WITH GFS POINT AT P53 /MUNISING/ SHOWING INVERSIONS OVER
6-8KFT TUE EVENING LOWERING TO 4-5KFT BY MIDNIGHT. GOOD PART OF DGZ
IS WITHIN THE LAKE CONVECTIVE LAYER...BUT SUBSIDENCE ALOFT AND QUICK
FORMATION OF ANTICYCLONIC SFC FLOW WITH THE HIGH BUILDING IN SHOULD
LIMIT LES INTENSITY. KEPT POPS HIGH...BUT QPF/SNOW QUICKLY COMES
DOWN AFT TUE EVENING. GUSTY NW WINDS 20-30 MPH WITH THE COLD AIR
ADVECTION IN BLYR SHOULD LEAD TO BLSN/LOWER VSBY AND COULD TIP THIS
TO NEEDING AN ADVY. JURY STILL OUT ON THAT THOUGH. WILL MENTION IN
THE HAZARDOUS WEATHER OUTLOOK.
LAKE EFFECT RUNS ITS COURSE ON WED AND AS SFC RIDGE CROSSES WED AFTN
INTO WED EVENING...SHOULD SHUT DOWN ON WED EVENING WITH LOSS OF
ONSHORE FLOW. SCT MID-HIGH CLOUDS...BUT MAY BE ANOTHER CHILLY NIGHT
WITH THE RIDGE IN THE VCNTY. GIVEN THIS SETUP PROBABLY DID NOT GO
COLD ENOUGH AND LATER SHIFTS MAY NEED TO LOWER TEMPS BELOW CONSENSUS.
LOWEST GUIDANCE SHOWING MINS IN THE SINGLE NUMBERS BLO ZERO FOR THE
INTERIOR.
ATTN LATE THIS WEEK IS ON STRONG WARM AIR ADVECTION PATTERN AS SFC
RIDGE SLIDES OVER NEW ENGLAND AND STRONG SFC LOW...THANKS IN PART TO
THAT VIGOROUS PACIFIC JET STREAM MENTIONED AT THE TOP...EXPANDS OVER
FM THE CANADIAN ROCKIES TO THE NORTHERN PLAINS. COLD AIR ALOFT WILL
GIVE WAY TO H85 TEMPS ABOVE ZERO AS EARLY AS THU EVENING WITH SURGE
OF WARMER AIR /H85 TEMPS MAYBE AS WARM AS +6C/ WASHING ACROSS THE
WESTERN GREAT LAKES ON FRI. WARMING EVENTUALLY MAKES IT TO SFC WITH
HIGH TEMPS WELL INTO THE 30S IF NOT INTO LOW 40S FOR PARTS OF
WESTERN CWA. UNTIL WARMING MAKES IT TO SFC...THE WARM AIR ALOFT WILL
RESULT IN THE SNOW THAT DEVELOPS IN WARM AIR ADVECTION PATTERN THU
AFTN INTO THU NIGHT TO CHANGE TO LIQUID PRECIP FM WEST TO EAST LATE
THU NIGHT INTO FRI. PRECIP COULD BE ENHANCED DEPENDING ON STRENGTH
OF SHORTWAVE DIGGING ACROSS THE UPPER GREAT LAKES. TEMPS WILL BE ON
THE RISE BUT LINGERING COLD TEMPS NEAR SFC COULD RESULT IN FZRA AND
ICING ISSUES AT LEAST BRIEFLY FOR PARTS OF CWA. SINCE S FLOW IS
STRONG AS SEEN BY THE H85 WINDS NEAR 50 KTS INTO WI ON THU NIGHT AS
THE SFC HIGH IS MORE EAST OF HERE VERSUS NORTHEAST /LIMITING COLD
DRY EASTERLY SFC FLOW THAT WOULD TEMPER SFC WARMING/...THINK THE
WARMING AT THE SFC WILL ARRIVE PRETTY QUICKLY SO MIXED PRECIP SHOULD
CONVERT TO RAIN EVEN AT THE SFC LATER FRI MORNING INTO FRI AFTN.
WILL CONTINUE TO MENTION WINTRY MIX AND ICE POTENTIAL IN THE
HAZARDOUS WEATHER OUTLOOK.
TREND IS FOR COOLER TEMPS TO RETURN NEXT SAT ONCE THE LARGE SFC LOW
AND WARM FRONT PASS TO THE EAST. JUST A SMALL CHANCE FOR SNOW
SHOWERS AT THAT TIME. CONSENSUS GUIDANCE UTILIZED FOR TEMPS WHICH
BROUGHT TEMPS BACK INTO THE 20S TO LOWER 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 625 AM EST SUN FEB 14 2016
DRY AIR ASSOCIATED WITH A HI PRES RDG TO THE E WL BRING VFR WX TO
THE TAF SITES THRU THIS AFTN. BUT AS DEEPER MSTR ARRIVES FM THE W
AHEAD OF AN APRCHG DISTURBANCE AND THE S WIND ON THE WRN FLANK OF
THIS HI ADVECTS MORE LLVL MSTR INTO UPR MI OFF LK MI...SOME LOWER
MVFR CIGS WL DVLP OVER THE AREA TNGT. THE BEST CHANCE FOR THE LOWER
MVFR CONDITIONS AND -SN WL BE AT SAW...WHICH WL BE MORE INFLUENCED
BY THE LK MI MOISTENING. WITH A DOWNSLOPE S WIND AND ABSENCE OF LK
MI INFLUENCE...IWD HAS THE BEST SHOT TO MAINTAIN A HIER CIG LONGER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 AM EST SUN FEB 14 2016
AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES DEPARTING TO THE E AND
A LO PRES TROF APPROACHING FROM THE W...EXPECT LIGHT WINDS TODAY
OVER THE LAKE TO INCREASE TO S WINDS UP TO 30 KTS TONIGHT. THE
HIGHEST WINDS WILL OCCUR NEAR THE CANADIAN BORDER OVER THE E
HALF...WHERE A FEW GALE FORCE GUSTS TO 35 KTS ARE POSSIBLE. THESE
WINDS WILL DIMINISH ON MON UNDER A WEAKENING GRADIENT. AFTER A
PERIOD OF RELATIVELY LIGHT WINDS LATER ON MON AND MON
NIGHT...ANOTHER ROUND OF STRONG NNW WINDS THAT WILL AT LEAST
APPROACH 35 KT GALES FOR A SHORT TIME WILL DEVELOP TUE NIGHT
FOLLOWING A COLD FRONTAL PASSAGE. BEST CHANCE FOR THESE GALES TO 35
KTS WILL BE OVER THE NCENTRAL AND E HALF. WINDS WILL THEN DIMINISH
WED WITH ARRIVAL OF ANOTHER HIGH PRES RIDGE. BUT STRONGER SSE WIND
UP TO 30 KTS WILL ARRIVE ON THU UNDER A TIGHTENING PRES GRADIENT
BETWEEN THIS HI SHIFTING TO THE E AND ANOTHER APPROACHING LO PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
948 AM CST SUN FEB 14 2016
.UPDATE...
ISSUED AT 942 AM CST SUN FEB 14 2016
NO SIGNIFICANT CHANGES WITH THIS UPDATE. CUT PRECIPITATION CHANCES
AS THE SNOW HAS VACATED THE FORECAST AREA...BUT DID LEAVE A
MENTION OF PATCHY FREEZING DRIZZLE OVER THE EASTERN THIRD OF THE
FORECAST AREA...MAINLY THE JAMES RIVER VALLEY. EXPERIMENTAL HRRR
RUNS HAVE BEEN CONSISTENT...SHOWING FREEZING DRIZZLE ON THE BACK
EDGE OF THE SNOW. WHILE THE OPERATIONAL HRRR IS NOT SHOWING THE
SAME SCENARIO...EARLIER EXPERIMENTAL RUNS HANDLED THIS MORNINGS
FREEZING DRIZZLE WELL. LATEST RAP FORECAST SOUNDINGS OVER
JAMESTOWN ALSO SUPPORT THIS SCENARIO.
UPDATE ISSUED AT 634 AM CST SUN FEB 14 2016
OVERALL...NO SIGNIFICANT CHANGE WITH THIS FORECAST UPDATE OTHER
THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC. CONTINUED THE
WINTER WEATHER ADVISORY ACROSS CENTRAL NORTH DAKOTA WITH FREEZING
DRIZZLE STILL FAVORED UNDER THE STRATUS DECK WITH ICE CRYSTALS
LACKING THROUGH MUCH OF THE COLUMN AS OBSERVED ON THE 12 UTC KBIS
SOUNDING. HOWEVER...SATURATION AT THE TOP OF THE LOW LEVEL
MOISTURE LAYER DOES APPROACH -10 TO -12 C...ALLOWING FOR A
CHANGE OVER TO SNOW OCCASIONALLY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 241 AM CST SUN FEB 14 2016
MAIN CONCERN IN THE SHORT TERM IS FREEZING DRIZZLE THAT DEVELOPED
BEFORE MIDNIGHT - ON THE WESTERN EDGE OF THE AREA OF LIGHT SNOW THAT
CONTINUES TO MOVE EAST ACROSS THE STATE. WILL BE ADDING A WINTER
WEATHER ADVISORY BACK INTO SOUTH CENTRAL NORTH DAKOTA BECAUSE OF THE
FREEZING DRIZZLE...AND EXTENDING THE ADVISORY THAT ENCOMPASSES ALL
OF CENTRAL NORTH DAKOTA UNTIL NOON CST.
CURRENTLY...UPPER LEVEL SHORTWAVE TROUGH EXTENDED FROM MANITOBA
SOUTHWARD ACROSS THE CENTRAL/EASTERN DAKOTAS. A CIRCULATION WAS NOTED
IN THE SATELLITE PICS OVER SOUTH CENTRAL/SOUTHEASTERN SOUTH
DAKOTA...WITH ANOTHER CIRCULATION NOTED IN THE REGIONAL RADAR LOOPS
OVER THE TURTLE MOUNTAINS AND DEVILS LAKE BASIN. THE AREA OF SNOW
ASSOCIATED WITH THE SHORTWAVE CONTINUED TO PUSH EASTWARD...WITH THE
WESTERN EDGE OF THE SNOW NEAR BOTTINEAU AND EAST OF THE MINOT AREA
IN THE NORTH CENTRAL...AND IN THE JAMES RIVER BASIN. AT THE
SURFACE...A WARM FRONT EXTENDED FROM NEAR STANLEY TO GLEN ULLIN AND
EAST OF HETTINGER...WHERE WEST TO NORTHWEST WINDS HAD DEVELOPED AND
LOW CLOUDS WERE DISSIPATING.
FORECAST SOUNDINGS DID SHOW THAT ONCE THE SNOW ENDS IN CENTRAL NORTH
DAKOTA THAT A DEEP LAYER OF SUPERCOOLED AIR WITH NO ICE CRYSTALS
ABOVE IT WOULD DOMINATE CENTRAL NORTH DAKOTA. THE FREEZING DRIZZLE
DEVELOPED AT BISMARCK AND LIGHT RADAR RETURNS SURROUNDING THE
BISMARCK RADAR CONFIRM THAT LIGHT FOG PARTICLES/DRIZZLE WERE INTENSE
ENOUGH TO BE DETECTED BY RADAR. MENTION OF FOG WEST OF THE SNOW
BANDS ARE LIKELY ACCOMPANIED BY FREEZING DRIZZLE. THINKING AREA OF
PATCHY FREEZING DRIZZLE IS BETWEEN THE AREA OF SNOW IN THE EAST AND
THE WARM FRONT TO THE WEST. WILL ADDRESS THIS WITH THE WINTER
WEATHER ADVISORY IN PLACE FOR ALL OF CENTRAL NORTH DAKOTA.
THE WARM FRONT IS FORECAST TO MOVE EAST ACROSS THE STATE TODAY...AND
HIGHS SHOULD RANGE FROM AROUND 40 FAR SOUTHWEST TO AROUND 30 TURTLE
MOUNTAINS/JAMES VALLEY. WEAK SHORTWAVE ENERGY IN THE NORTHWEST FLOW
ALOFT MAY BRING SOME LIGHT RAIN TO FAR SOUTHWESTERN NORTH DAKOTA
THIS AFTERNOON. A MILD NIGHT TONIGHT WITH LIGHT WESTERLY WINDS AND
LOW TEMPERATURES IN THE 20S ARE EXPECTED.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 241 AM CST SUN FEB 14 2016
ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST.
THE 00 UTC SUITES ARE IN GOOD AGREEMENT ON A BROAD UPPER LEVEL
RIDGE BUILDING ACROSS THE CENTRAL CONUS THIS COMING WEEK...WITH
RESULTANT ABOVE NORMAL TEMPERATURES FOR THE PERIOD. THE 00 UTC
NAEFS MEAN 850 MB TEMPERATURE ANOMALIES ARE FORECAST TO CLIMB TO
THEIR 97.5 TO 99.5+ PERCENTILES BY THURSDAY ACROSS WESTERN AND
CENTRAL NORTH DAKOTA. THIS SUPPORTS THE POTENTIAL FOR WIDESPREAD
50S FOR HIGHS ALONG AND WEST OF THE MISSOURI RIVER BY
THURSDAY...POSSIBLY APPROACHING RECORD VALUES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 634 AM CST SUN FEB 14 2016
AT 1230Z A SURFACE LOW PRESSURE TROUGH/WARM FRONT EXTENDED FROM THE
BORDER OF SASKATCHEWAN/MANITOBA TO NEAR KMOT TO NEAR KBIS AND ALONG
THE MISSOURI RIVER SOUTH INTO SD. WEST OF THE FRONT AT KISN/KDIK
WEST TO NORTHWEST WINDS WILL PREVAIL...AND MVFR CIGS TO BECOME VFR
BY AROUND 13Z-15Z THIS MORNING. MEANWHILE ALONG AND EAST OF THE
FRONT AT KBIS/KMOT/KJMS LOOK FOR IFR/MVFR CIGS AND VSBYS IN LIGHT
SNOW...FOG AND FREEZING DRIZZLE. CONDITIONS IMPROVING AT KMOT/KBIS
BY 18Z. KJMS TO REMAIN MVFR/IFR UNTIL LATE AFTERNOON OR EARLY
EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ZH
SHORT TERM...JV
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1033 AM EST SUN FEB 14 2016
.SYNOPSIS...
SNOW WILL OCCUR NORTH OF A WARM FRONT THAT WILL APPROACH FROM THE
SOUTHWEST TODAY AND LIFT THROUGH THE AREA TONIGHT. AN AREA OF LOW
PRESSURE WILL PASS JUST SOUTHEAST OF THE REGION MONDAY AFTERNOON
AND NIGHT. ANOTHER LOW PRESSURE SYSTEM WILL CROSS THE AREA TUESDAY
AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH TONIGHT/...
ADJUSTMENTS FOR THE NEAR TERM OF THE FORECAST WERE FOCUSED ON THE
SNOW POTENTIAL THIS AFTERNOON...WITH SOME SLIGHT ADJUSTMENTS TO
FORECAST NUMBERS REQUIRED. SOME MINOR CHANGES WERE ALSO MADE
OVERNIGHT AND GOING INTO MONDAY...BUT THE FORECAST THINKING FOR
THE SETUP FROM OVERNIGHT INTO TOMORROW HAS NOT CHANGED MUCH.
WATER VAPOR SATELLITE IMAGERY SHOWS A WELL-DEFINED SPIN IN
IOWA...ASSOCIATED WITH THE SHORTWAVE THAT IS MOVING TOWARD THE
REGION TODAY. AS THIS SHORTWAVE MOVES EAST...FORCING IS BEGINNING
TO INCREASE IN THE LOWER OHIO VALLEY...DRIVEN JUST AS MUCH BY
FORCING A LITTLE LOWER IN THE ATMOSPHERE. WITH HIGH PRESSURE
MOVING EAST OF THE OHIO VALLEY...A SWITCH TO SOUTHERLY FLOW HAS
OCCURRED...AND WARM FRONTAL PROCESSES ARE UNDERWAY. CONVERGENCE
AND ISENTROPIC ASCENT IS GRADUALLY INCREASING IN STRENGTH AHEAD OF
THE INCREASED SOUTHERLY FLOW...AND PRECIPITATION IN ILLINOIS /
WESTERN KENTUCKY / EASTERN MISSOURI HAS BECOME WIDESPREAD.
ALTHOUGH MODELS ARE IN STRONG AGREEMENT ON THIS OVERALL
SETUP...THERE ARE STILL SOME CONFLICTING FACTORS PREVENTING A
HIGH-CONFIDENCE FORECAST FOR THE EVENTUAL SNOWFALL NUMBERS. RECENT
HIGH-RESOLUTION MODEL RUNS AND SOME OF THE 06Z OPERATIONAL RUNS
HAVE DEFINITELY INDICATED A LITTLE STRONGER FORCING THAN PERHAPS
PREVIOUSLY INDICATED. CONSEQUENTLY...QPF AMOUNTS (ESPECIALLY OVER
THE FAR SOUTHWESTERN CWA) HAVE INCREASED AS WELL. OF COURSE...QPF
SHOULD ONLY BE USED AS ONE FACTOR IN THE FORECAST PROCESS...AND
NEEDS TO BE SCRUTINIZED. THE LOCATION AND STRENGTH OF THE FORCING
AND MOISTURE ARE OF GREATER CONCERN TO LOOK INTO. FOR
EXAMPLE...BOTH THE RECENT HRRR AND RAP RUNS HAVE AROUND A TENTH OF
AN INCH OF LIQUID EQUIVALENT IN THE SOUTHWESTERN ILN COUNTIES
BEFORE 18Z...VALUES THAT ARE SIMPLY NOT OCCURRING RIGHT NOW (WITH
JUST ONE OR TWO REPORTS OF SOME LIGHT SNOW FROM THE MOSTLY-VIRGA
ECHOES CURRENTLY MOVING THROUGH CENTRAL AND EASTERN KENTUCKY).
FURTHERMORE...SNOW RATIOS MUST BE CONSIDERED THROUGH THE DEPTH OF
THE THERMAL PROFILE...AND CANNOT BE BASED SOLELY ON SURFACE
TEMPERATURES. IN FACT...IT IS THE STRENGTH OF THE WARMING ALOFT
(LEADING TO THE ISENTROPIC ASCENT) THAT WILL HELP LIMIT SNOW
RATIOS...BY DEVELOPING A DEEP ISOTHERMAL LAYER OF ROUGHLY -8C TO
-10C FROM THE SURFACE THROUGH 700MB. THIS IS NOT ESPECIALLY
FAVORABLE FOR EFFICIENT SNOW PRODUCTION...AND WILL LIKELY KEEP
RATIOS AT OR BELOW 15:1. HOWEVER...THERE WILL BE A PERIOD WHERE
THE CONTRIBUTION OF FORCING FROM THE SHORTWAVE ALLOWS FOR ASCENT
THROUGH AN EVEN DEEPER LAYER...PERHAPS ALLOWING FOR A PERIOD OF AN
HOUR OR TWO WITH SOME HEAVIER SNOW RATES.
WITH ALL THE FACTORS CONSIDERED TOGETHER...SNOW NUMBERS WERE
INCREASED BY ABOUT A HALF INCH THROUGH THE CENTER OF THE ILN
FORECAST AREA...AND BY ALMOST AN INCH IN THE FAR SOUTH AND
SOUTHWEST. THE WSW PRODUCT WAS BROKEN OUT INTO TWO GROUPS TO
ALLOW FOR A 2-3 INCH FORECAST AND A 3-4 INCH FORECAST.
THE FORECAST THINKING DID NOT CHANGE MUCH WITH REGARDS TO THE
POTENTIAL FOR FREEZING DRIZZLE EARLY MONDAY MORNING. ONCE THE
DEEP-LAYER MOISTURE HAS DEPARTED...AND SATURATION IS LIMITED TO
BELOW -10C...ICE CRYSTALS ARE UNLIKELY TO BE INTRODUCED INTO THE
ATMOSPHERE. THOUGH STRONG FORCING WILL ALSO BE DEPARTED...WEAK
ISENTROPIC ASCENT WILL CONTINUE IN THE LOW-LEVELS...ALLOWING FOR
THE POTENTIAL FOR FREEZING DRIZZLE. THOUGH TEMPERATURES WILL BE
RISING GOING INTO MONDAY MORNING...THE COLD GROUND CONDITIONS
WILL BE VERY SLUGGISH IN THEIR RESPONSE...WITH SOME POTENTIAL FOR
LIGHT DEPOSITION OF ICE IF DRIZZLE IS ABLE TO DEVELOP.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
SHORT WAVE TRACKING OUT OF THE SOUTHERN PLAINS WILL HEAD INTO THE
CENTRAL APPALACHIANS MONDAY INTO MONDAY NIGHT. GUIDANCE IS COMING
INTO PRETTY GOOD AGREEMENT THAT THE ASSOCIATED SURFACE LOW WILL
MOVE FROM MIDDLE TENNESSEE INTO EASTERN KENTUCKY AND THEN WEST
VIRGINIA. SHIELD OF PRECIPITATION NORTH OF THE LOW WILL SPREAD
INTO THE SOUTHERN AND EASTERN ZONES MONDAY AFTERNOON THROUGH
MONDAY NIGHT. WARMER TEMPERATURES SHOULD RESULT IN MUCH OF THE
PRECIPITATION WILL BE IN THE FORM OF RAIN EXCEPT PERHAPS ON THE
NORTHWEST EDGE.
A NARROW SURFACE RIDGE WILL MOVE ACROSS THE REGION TUESDAY
MORNING PROVIDING A BRIEF RESPITE FROM PRECIPITATION. BUT THEN A
WELL DEVELOPED CLIPPER WILL MOVE ACROSS THE AREA TUESDAY AFTERNOON
AND NIGHT. 00Z NAM AND GFS ARE IN EXCELLENT AGREEMENT BUT WITH THE
ECMWF BEING A BIT SLOWER THERE IS SOME TIMING UNCERTAINTY.
CURRENTLY APPEARS THAT THIS WILL BRING SNOW IN THE NORTHERN PART
OF THE FORECAST AREA WITH RAIN OR SNOW IN THE SOUTH DEPENDING ON
THE LOW LEVEL TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ON WEDNESDAY...WILL GO WITH A DRY FORECAST...ALTHOUGH CONSIDERABLE
CAA STRATOCUMULUS IS EXPECTED.
FOR WEDNESDAY NIGHT INTO THURSDAY...HIGH PRESSURE WILL BUILD SOUTH
INTO THE OHIO VALLEY. SKIES ARE EXPECTED TO BECOME PARTLY CLOUDY.
MODELS DIFFERENT ON THE EXTENT OF COLD AIR FILTERING IN THE
REGION...SO HAVE SIDED WITH A WPC BLENDED APPROACH.
AS THE HIGH MOVES EAST THURSDAY NIGHT...A WARM FRONT IS FORECAST TO
APPROACH FROM THE WEST. WE SHOULD SEE AN INCREASE IN WAA INDUCED
CLOUDS. AS OF NOW...ANY PCPN GENERATED WITH THE WARM FRONT IS
EXPECTED TO STAY NORTHWEST OF THE AREA. OVERNIGHT LOWS WILL BE EARLY
FOLLOWED BY SLOWLY RISING TEMPERATURES AS WINDS INCREASE FROM THE
SOUTH.
FOR FRIDAY INTO FRIDAY NIGHT...LOW PRESSURE WILL TRAVERSE THE GREAT
LAKES AS A COLD FRONT PUSHES IN FROM THE NORTHWEST. MODELS VARY ON
HOW MUCH MOISTURE WILL BE PULLED NORTHWARD ALONG AND AHEAD OF THE
FRONT SYSTEM...ALONG WITH THE TIMING...SO HAVE GONE WITH A CHANCE OF
RAIN. FRIDAY CERTAINLY LOOKS TO BE THE WARMEST DAY OF THE EXTENDED
WITH TEMPERATURES RISING INTO THE 50S AREA WIDE.
ON SATURDAY...FRONT EXITS TO THE EAST...BUT CAA STRATOCUMULUS MOVES
INTO THE REGION. PCPN WILL MOVE EAST AS WELL. TEMPERATURES WILL COOL
INTO THE MID 40S TO LOWER 50S FOR HIGHS.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR AND DRY CONDITIONS WILL START OUT THE TAF PERIOD. ALTHOUGH A
FEW FLURRIES CANNOT BE RULED OUT AT KCVG THIS MORNING MOST OF THE SNOW
WILL MOVE INTO THE TAF SITES THIS AFTERNOON INTO TONIGHT. CIGS
WILL LOWER AND VSBYS WILL BE REDUCED WITH THE SNOWFALL.
THE DEEPER MOISTURE WILL MOVE OUT TONIGHT. THERE IS SOME QUESTION
AS TO WHETHER ICE WILL BE IN THE CLOUDS OVERNIGHT TONIGHT INTO
EARLY MONDAY MORNING. WHETHER OR NOT THERE IS OR NOT WILL
DETERMINE WHETHER OR NOT LIGHT SNOW WILL CONTINUE OVERNIGHT
TONIGHT OR WHETHER FREEZING DRIZZLE WILL BE PRESENT. THERE ARE
ENOUGH INDICATIONS TO SUGGEST THAT SNOW WILL TRANSITION TO
FREEZING DRIZZLE AND THEREFORE HAVE FREEZING DRIZZLE IN TOWARDS
THE END OF THE TAF PERIOD. CIGS WILL BE LOWER IN THE IFR CATEGORY
DURING THIS TIME AND POTENTIALLY EVEN LIFR.
OUTLOOK...MVFR/IFR CONDITIONS ARE POSSIBLE WITH PRECIPITATION
FROM MONDAY THROUGH TUESDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR OHZ063>065-
070>074-077>082-088.
KY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR KYZ089>100.
IN...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR INZ066-
073>075-080.
&&
$$
SYNOPSIS...
NEAR TERM...HATZOS
SHORT TERM...
LONG TERM...HICKMAN
AVIATION...NOVAK
AREA FORECAST DISCUSSION
NWS Tulsa OK
550 AM CST SUN FEB 14 2016
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
MVFR conditions this morning are expected to persist into the
afternoon hours for much of Northeast Oklahoma...while persisting
through the day for Southeast Oklahoma and Northwest Arkansas. A
surface boundary moving through the region along with an upper
level wave approaching will allow for light areas of rain/drizzle
for Eastern Oklahoma and Northwest Arkansas today. Some light
freezing rain/drizzle could be possible this morning for
FYV/ROG/XNA sites. Periods of IFR conditions could also be
possible within any precipitation. Overnight...VFR conditions are
forecast for Northeast Oklahoma...while MVFR should remain for the
rest of the CWA.
&&
.PREV DISCUSSION... /ISSUED 255 AM CST SUN FEB 14 2016/
DISCUSSION...
The dry low-levels are winning out so far this morning...with the
atmosphere being very slow to moisten. HRRR and RUC both suggest
that light precipitation won`t develop into the forecast until
beyond 12z...and it`s still looking like the deeper valley regions
of Carroll...Madison and Franklin counties will experience the
main impact from any light icing. Have opted to extend the winter
weather advisory until 18z...with temperatures warming above
freezing by early afternoon. Afternoon temperatures across the
remainder of the forecast area will be highly dependent on amount
of clearing...and have nudged highs down a few degrees over the
previous forecast.
The main story for next week will be an impressive warming
trend...especially toward the end of the week. A weak boundary
should work into the region by Tuesday beneath the northwesterly
upper flow...but still expect afternoon highs to reach the 60s in
most locations. The big warmup comes by Thursday and continuing
into Friday as strong south to southwest winds develop. Will
continue to go at or above the warmest guidance numbers...with
current forecast highs for Thursday near record levels.
Temperatures should moderate some going into next weekend...but
still remain well above seasonal norms. Have kept the forecast dry
at this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 53 37 65 44 / 30 0 10 10
FSM 48 37 63 39 / 50 20 10 10
MLC 54 38 65 42 / 30 20 10 0
BVO 55 33 64 34 / 20 0 10 10
FYV 43 31 60 35 / 50 10 10 10
BYV 41 32 59 36 / 50 10 10 10
MKO 49 36 63 38 / 40 10 10 10
MIO 49 33 61 38 / 30 0 10 10
F10 54 37 65 40 / 30 10 10 10
HHW 60 45 67 42 / 20 50 20 0
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...Winter Weather Advisory until noon CST today for ARZ001-002-010-
011-019-020.
&&
$$
AVIATION...20
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
956 AM EST SUN FEB 14 2016
.SYNOPSIS...
SURFACE HIGH WILL MOVE ACROSS THE TODAY...THEN OFF THE EAST COAST
TONIGHT. A DEEPENING UPPER LVL TROF OVER THE CENTRAL CONUS WILL
SPAWN A LOW PRES SYSTEM...WHICH WILL LIKELY TRACK NORTHWARD ACROSS
EASTERN PA ON TUESDAY. LATER IN THE WEEK...A RIDGE OF HIGH PRESSURE
MOVES IN ALOFT WITH MUCH WARMER AIR FOR LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
WITH THE EXCEPTION OF THE NORTHERN TIER COUNTIES....IN MOST AREAS
TEMPERATURES ARE IN THE SINGLE DIGITS TO LOW TEENS IN THE SOUTH
AND WITH LIGHT WINDS THE WINDCHILL ISSUES ARE NO LONGER
SIGNIFICANT. ALONG THE NEW YORK BORDER THERE ARE STILL MANY
LOCATIONS WITH TEMPERATURES BELOW ZERO AND WINDCHILLS IN THE -10
TO -20 RANGE.
THE TEMPERATURES SHOULD RISE TODAY AND WITH LIGHT WINDS ALL
WINDCHILL ISSUES WILL BE HISTORY. WE HAVE LET BOTH THE ADVISORY
AND WARNINGS EXPIRE AS OF 11 AM.
HIGH PRESSURE OVER THE REGION WILL MOVE OUT OVER THE WESTERN
ATLANTIC AND HIGH CLOUDS FROM THE APPROACHING STORM SYSTEM WILL
SPREAD CLOUDS FROM SOUTHWEST TO NORTHEAST OVER THE REGION THIS
AFTERNOON AND EVENING. LIGHT SNOW COULD ARRIVE IN EXTREME
SOUTHEASTERN AREAS LATER THIS EVENING.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE HRRR AND 12Z NAM SHOW LIGHT SNOW ARRIVING LATER EVENING IN
SOUTHWESTERN AREAS AND VERY SLOWY SPREADING NORTHWARD.
IT SHOULD BECOME CLOUDY OVERNIGHT OVER MUCH OF THE REGION WITH
TEMPERATURES FALLING EARLY THEN SLOWLY RISING OVERNIGHT. ANY SNOW
WILL BE VERY LIGHT AND MAINLY OVER THE SOUTHERN THIRD OF THE
REGION.
THE SREF IMPLIES MAINLY VERY LIGHT SNOW OVER SOUTHWESTERN AND
WESTERN AREAS THROUGH MID-MORNING MONDAY. THEN THE PROBABILITY OF
SNOW RAPIDLY SPREADS NORTHWARD IN THE AFTERNOON HOURS WITH SNOW OR
MIXED PRECIPITATION EVERYWHERE BY LATE AFTERNOON. BUT WARM AIR
WILL CAUSE A MIXING WITH ICE PELLETS AND FREEZING RAIN IN SOUTHERN
AREAS BY AFTERNOON.
THE SNOW WILL MIX WITH ICE PELLETS FARTHER NORTH LATER IN THE
EVENING AND OVERNIGHT WHICH IS THE NEXT PERIOD.
WE ARE GOING TO ISSUE A WINTER WEATHER ADVISORY AFTER ABOUT
MIDDAY AFTER WE SEE MORE 12Z MODELS AND ENSEMBLES.
PREVIOUS:
DEVELOPING WAA BTWN DEPARTING SFC HIGH AND WEAKENING SHORTWAVE
APPROACHING FROM THE MIDWEST WILL SPREAD INCREASING CLOUDINESS
ACROSS THE STATE OVERNIGHT. A BIT OF LGT SNOW COULD DEVELOP OVR
THE SOUTHERN AND WESTERN COUNTIES LATE SUN NIGHT.
HOWEVER...RESIDUAL LOW PWAT AIR ASSOC WITH DEPARTING ARCTIC AIR
MASS SHOULD LIMIT ANY ACCUMS TO A DUSTING.
EARLY RADIATIONAL COOLING SHOULD DROP TEMPERATURES OFF FAST THIS
EVENING...BUT RETURN FLOW AND INCREASING CLOUD COVER SHOULD CAUSE
TEMPERATURES TO BEGIN TO SLOWLY RISE LATE TONIGHT.
SPOTTY LGT SNOW ACROSS CENTRAL/SOUTHERN PA MON MORNING WILL
LIKELY GIVE WAY TO A STEADIER SNOW ACROSS SOUTHERN PA LATE IN THE
DAY...AS ISENTROPIC LIFT INCREASES AHEAD OF POTENT SHORTWAVE
APPROACHING FROM THE MISS VALLEY AND ASSOC SOUTHERLY LL JET.
GEFS/SREF PTYPE PROBS SUGGEST SOME MIXING MAY WORK INTO THE S TIER
COUNTIES BY EVENING.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MDL SPREAD CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW
ACROSS EASTERN PA TUESDAY...SUPPORTING RAISING POPS TO NEAR 100
PCT LATE MONDAY-EARLY TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR
RAIN ACROSS EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. BULK OF
MDL GUIDANCE SUPPORTS AN EVENTUAL TURNOVER TO RAIN ACROSS ALL BUT
PERHAPS THE NW MTNS BY EARLY TUES AM. ENSEMBLE PLUMES AND WPC
GUIDANCE SUPPORT A GENERAL 1-3 INCH SNOW ACCUM BEFORE CHANGEOVER.
SFC HIGH PROGGED EAST OF NJ IS IN A POSITION UNFAVORABLE TO HOLD
LL COLD AIR IN PLACE. HOWEVER...A TRANSITION PERIOD OF FZRA STILL
APPEARS QUITE POSSIBLE ACROSS CENTRAL PA MON EVENING. WPC GUIDANCE
SUPPORTS MARGINAL WARNING CRITERIA FOR ICE ACCRETION OVR THE SC
MTNS. HOWEVER...SREF/GEFS PLUMES INDICATE SUCH ICE AMTS ARE FAR
FROM CERTAIN. HAVE THEREFORE DECIDED TO HOLD OFF ON HEADLINES
ATTM. MAIN EVENT DOESN/T UNFOLD UNTIL LATE MONDAY...SO STILL TIME
TO HONE FCST WITH BENEFIT OF LATER GUIDANCE.
WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS
SOUTHEAST PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL
ENSEMBLE RIVER FORECASTS SUGGESTS MINOR FLOODING IS A POSSIBILITY
ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS HIGHLIGHTED SE
PA FOR A SLIGHT RISK OF FLOODING TUESDAY.
NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS
HEIGHTS ARE FORECAST TO RISE AND A PSBL LOW PRESSURE SYSTEM LIFTS
THROUGH THE GREAT LAKES TO THE WEST OF PA.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
GENERALLY GOOD WEATHER TODAY BECOME VFR ALL LOCATIONS. COLD WITH
LIGHT WINDS. CLOUDS MOVE IN LATER THIS AFTERNOON AND EVENING AHEAD
OF APPROACHING WAVE.
PERIOD OF NICE WEATHER WILL BE SHORT-LIVED AS CIG RESTRICTIONS
SLIDE IN FROM THE SW AGAIN STARTING OVERNIGHT TONIGHT AHEAD OF
NEXT STORM SYSTEM. SNOW MONDAY WILL TRANSITION TO ASSORTED WINTRY
PRECIPITATION MONDAY NIGHT AND THEN AREAS OF RAIN IN THE SE HALF
ON TUE. EXPECT A LONG-DURATION IMPACT TO FLYING CONDITIONS MONDAY
INTO TUESDAY.
OUTLOOK...
MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING.
MON NIGHT AND TUE...SNOW LIKELY WRN HALF OF PENN...WITH RAIN
AND/OR SNOW IN THE SE. WIDESPREAD RESTRICTIONS SET IN. LLWS POSS
SE.
WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN
PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST.
THU...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL 11 AM EST THIS MORNING FOR PAZ004>006-
037-041-042.
WIND CHILL ADVISORY UNTIL 11 AM EST THIS MORNING FOR
PAZ010>012-017>019-024>028-033>036-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...FITZGERALD/GARTNER
AVIATION...GRUMM/RXR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
307 PM MST SUN FEB 14 2016
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 306 PM MST SUN FEB 14 2016
A FAST MOVING SYSTEM WAS PRODUCING ITS GREATEST IMPACTS THIS
AFTERNOON INTO EARLY EVENING. THE DYNAMICAL PORTION OF THE STORM
IS DRIVEN BY A N-S ORIENTED 110KT JET STREAK. THIS JET SHIFTED
INTO NW CO AROUND MIDDAY AND WILL BE EAST OF THE DIVIDE THIS
EVENING. DENDRITIC CRYSTAL GROWTH REGION IS NEAR SATURATION
THROUGH THIS PERIOD AT AROUND 600MB/14KFT. ON THE EAST SIDE OF
THE JET NOSE...SNOW SPREAD INTO NW COLORADO JUST BEFORE NOON AND
INTO THE ROARING FORK VALLEY AROUND 1PM. THE I-70 CORRIDOR FROM
GLENWOOD EAST COULD GET SOME LIGHT ACCUMULATION THIS AFTERNOON.
BEFORE MIDNIGHT THE DYNAMICAL PORTION OF THE STORM IS OVER AND IT
BECOMES AN WNW OROGRAPHIC EVENT. THIS IS STILL OPTIMAL FOR THE
PARK RANGE AND STEAMBOAT SPRINGS AREA. CURRENT HIGHLIGHTS
EMPHASIZE THE BEST SNOW FROM STEAMBOAT NORTHWARD AND THIS STILL
LOOKS CORRECT. THE PARK RANGE TO VAIL PASS AND THE FLAT TOPS AND
ADJOINING VALLEYS WILL CONTINUE TO SEE SNOW ACCUMULATIONS THROUGH
THE NIGHT. WIND GUSTS OF 30-40 MPH OVER THE HIGH TERRAIN WILL
PRODUCE BLOWING AND DRIFTING SNOW. AREAS OF LATE NIGHT FOG WILL
LIKELY FORM IN NW COLORADO...EASTERN PORTIONS OF THE I-70
CORRIDOR...AND ROARING FORK VALLEY.
UPPER LEVEL SUPPORT BY WAY OF THE JET STREAM WILL HAVE SHIFTED
WELL TO OUR EAST BY MONDAY MORNING WHICH SHOULD CAUSE SNOWFALL UP
NORTH TO DECREASE IN INTENSITY. ACCORDING TO THE NAM AND GFS...SNOW
IS NOT OVER THOUGH AS FAVORABLE OROGRAPHICS THEN KICK IN ALLOWING
SNOW TO CONTINUE FOR MUCH OF MONDAY ESPECIALLY FOR THE MOUNTAINS
AND FLAT TOPS. HOWEVER...THE VERY SHORT RANGE MODELS...TO INCLUDE
THE HRRR AND RAP13...SHOW PRECIP DWINDLING THROUGH THE DAY WITH
ONLY MINIMAL ACCUMULATION EXPECTED. WITH H7 WINDS COMING FROM THE
NORTHWEST...OROGRAPHICS LOOK LIKE THEY WILL BE IN PLAY SO THE
GOING ADVISORIES WILL REMAIN IN PLACE. LATER SHIFTS CAN REASSESS
AND PULL DOWN EARLY IF NEEDED.
THE REST OF THE CWA WILL SEE WARMING TEMPS MONDAY WITH MANY AREAS
SEEING PARTLY CLOUDY SKIES. AREAS DOWN SOUTH WILL LIKELY SEE MORE
SUN THAN CLOUDS WHILE MTNS WILL SEE VARIABLE CLOUDINESS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 306 PM MST SUN FEB 14 2016
BY NOON TUESDAY...SNOWFALL WILL HAVE ENDED AS HEIGHT RISES
INDICATE HIGH PRESSURE BUILDING IN. THE HIGH PRESSURE WILL BE IN
CONTROL FROM TUESDAY THROUGH THURSDAY WITH ONLY SOME HIGH CLOUDS
MOVING OVERHEAD FROM TIME TO TIME. TEMPERATURES WILL CONTINUE
THEIR WARM TREND FOR A NICE START TO THE WORK WEEK.
STARTING LATE WEDNESDAY...BOTH THE GFS AND EC HIGHLIGHT AN AREA OF
LOW PRESSURE APPROACHING THE WEST COAST BRINGING PLENTY OF PRECIP
TO NRN CALIF UP INTO BRITISH COLUMBIA. HOWEVER...THE CLOSED LOW
FILLS IN AND MOVES NORTH WHILE THE ASSOD TROUGH CONTINUES TO MOVE
EASTWARD. THERE IS SOME UPPER LEVEL SUPPORT WITH THIS FEATURE AS
THE JET STREAM CARRIES THIS WAVE ACROSS THE INTERMOUNTAIN WEST. AS
THE WAVE MOVES EAST...THE JET BECOMES MORE EAST TO WEST ORIENTED
WHICH WILL CAUSE THE SYSTEM TO QUICKLY MOVE OVER THE AREA. MODELS
SUGGEST INCREASED CLOUDS THURSDAY WITH SOME SHOWERS THROUGH THE
DAY. THE HEAVIEST PRECIP LOOKS TO FALL LATE THURSDAY NIGHT INTO
EARLY FRIDAY MORNING AGAIN FAVORING THE NRN AND CENTRAL
MTNS...FLAT TOPS...AND POSSIBLY THE GRAND MESA. BECAUSE OF THE JET
ORIENTATION THOUGH...IT LOOKS AS THOUGH A QUICK 6 HRS OF HEAVIER
PRECIP BEFORE IT SHUTS OFF ABRUPTLY BY DAYBREAK FRIDAY. A FEW MORE
MODEL RUNS WILL INCREASE CONFIDENCE WITH EVOLUTION OF SYSTEM.
AFTER THAT...A WEAK WAVE LOOKS TO MOVE OVER THE CWA SATURDAY
BRINGING VERY LIGHT PRECIP TO THE AREA BEFORE IT QUICKLY SHIFTS
EASTWARD.
EXPECT A NICE START TO THE WORK WEEK BEFORE MORE PRECIP ENTERS
THE PICTURE THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL ALSO
REMAIN ON THE WARM SIDE WHICH WILL BE NICE FRO MID-FEBRUARY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MID DAY)
ISSUED AT 1000 AM MST SUN FEB 14 2016
SNOW WILL INCREASE ALONG AND NORTH OF THE CO I-70 CORRIDOR THROUGH
THE AFTERNOON. AFT 21Z MOUNTAIN TOPS ACROSS NW COLORADO WILL
BECOME OBSCURED AT TIMES. KEGE KASE WILL HAVE PERIODS OF MVFR
CONDITIONS WITH CIGS 030-050 AND VSBY 3-5SM IN SNOW. STRONG NW
WINDS AT AND ABOVE MTN TOP LEVEL WILL KEEP TURBULENCE ELEVATED
WITH POSSIBILITY OF LOW LEVEL WIND SHEAR. AFT 12Z SNOW WILL BE
LIMITED TO THE MTNS ALONG AND NORTH OF VAIL PASS INTO WYOMING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST MONDAY NIGHT FOR
COZ004-005-013.
WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ010.
UT...NONE.
&&
$$
SHORT TERM...JOE/TGR
LONG TERM...TGR
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
956 AM MST SUN FEB 14 2016
.UPDATE...
ISSUED AT 955 AM MST SUN FEB 14 2016
W/NWLY SFC WINDS HAVE BEEN QUITE STRONG ABOVE TIMBERLINE THIS
MORNING WITH LOCALIZED GUSTS UPWARDS OF 70 MPH. HIGH MTN CAMS
INDICATED CONSIDERABLE BLOWING SNOW MAINLY ABOVE TIMBERLINE.
HOWEVER IN THE PAST HOURS...THESE SAME WIND SENSORS HAVE SHOWN A
DROP OFF IN WIND SPEEDS. THIS MATCHES WELL WITH MODEL GUIDANCE AS
IT INDICATES A REDUCTION IN MTN TOP FLOW DURING THE NEXT 2-4 HRS...
THEN A STEADY INCREASE AS THE NOSE OF A 120-130KT JET PASSES OVER
NRN COLORADO. AS FOR THE SNOW POTENTIAL IN THE HIGH COUNTRY...
SLOW GOING NEXT FEW HOURS...THEN A STEADY INCREASE IN BOTH COVERAGE
AND INTENSITY AS 700-500MB QUASI-GEOSTROPHIC ASCENT INCREASING AND
COLD AIR ADVECTION KICKS IN THE WAKE OF A WEAK SHORTWAVE TROUGH MODELS
SHOW SWEEPING ACROSS N-CNTRL/NERN COLORADO LATER THIS AFTERNOON.
THE CONVEYOR PACIFIC MOISTURE UPSTREAM OF NWRN COLORADO DOES NOT
LOOK TERRIBLY DEEP...BUT COMBO OF LARGE SCALE LIFT AND OROGRAPHIC
FORCING SHOULD HAVE LITTLE TROUBLE GENERATING THE SNOW AMOUNTS
INDICATED IN THE WINTER WEATHER ADVISORY ISSUED FOR THE NRN MTN
ZONES 31..33-34 STARTING AT 19Z TODAY. STG WINDS...BITTER COLD
WIND CHILLS AND CONSIDERABLE BLOWING SNOW MAY POSE MORE OF A
PROBLEM FOR MTN RESIDENTS AND HIGH COUNTRY TRAVELERS ESPLY THOSE
CROSSING THE HIGH PASSES LATER THIS AFTERNOON AND EVENING.
ELSEWHERE...WESTERLY WINDS IN THE FRONT RANGE FOOTHILLS ARE ALSO
EXPECTED TO STRENGTHEN THIS AFTERNOON. COULD SEE GUSTS IN THE
45-55 MPH RANGE. NEARBY PLAINS ALREADY SEEING THESE GUSTY WLY
WINDS WITH THE STNRY MTN WAVE HELPING TO MIX DOWN STRONGER FLOW
ALOFT. SHOULD SEE THE STRONGER GUSTY WLY WINDS FIRST WITHIN THE
I-25 CORRIDOR AND THEN OUT ACROSS THE NERN PLAINS THIS AFTERNOON.
IN ADDITION...MODEL CROSS SECTIONS SHOW CLOUD BASES LOWERING OVER
THE NERN PLAINS THIS AFTERNOON WITH PASSAGE OF THE WEAK SHORTWAVE.
ITS POSSIBLE WE COULD SEE A FEW LIGHT RAIN SHOWERS OR RAIN/SNOW
SHOWERS OUT THERE...BUT MEASURABLE PRECIP NOT LIKELY AS THE SUB-
CLOUD LAYER APPEARS QUITE DRY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM MST SUN FEB 14 2016
RATHER STG WNW FLOW ALOFT WILL CONTINUE OVER NRN CO THRU TONIGHT.
MOISTURE WILL GRADUALLY INCREASE IN THE MTNS BY MIDDAY WITH BETTER
LAPSE RATES BY AFTN. THUS SHOULD SEE A GRADUAL INCREASE IN SNOW BY
AFTN WHICH WILL CONTINUE THRU THE EVENING HOURS ESPECIALLY ALONG AND
NORTH OF I-70. AFTER MIDNIGHT MOISTURE WILL DECREASE SOMEWHAT
HOWEVER WILL STILL SEE PERIODS OF LIGHTER OROGRAPHIC SNOW IN MOST
MTN AREAS. MEANWHILE GUSTY WINDS WILL PRODUCE AREAS OF BLOWING SNOW
ABV 10000 FT. WILL ISSUE AN ADVISORY FOR MTN AREAS ALONG AND NORTH
OF I-70 THIS AFTN THRU TONIGHT. PORTIONS OF ZN 31 COULD GET CLOSE
TO WARNING CRITERIA IF LATEST HRRR IS CORRECT.
AT LOWER ELEVATIONS A PACIFIC FNT WILL MOVE ACROSS THIS AFTN WITH
GUSTY NWLY WINDS DEVELOPING FM THE FOOTHILLS ACROSS THE PLAINS. WITH
STG DOWNSLOPE COMPONENT IN PLACE PCPN POTENTIAL OVER NERN CO LOOKS
TO BE RATHER LOW HOWEVER THERE WILL BE SOME MID LVL QG ASCENT
LATER THIS AFTN INTO THE EARLY EVENING HOURS SO WILL KEEP IN A
SLIGHT CHC OF SHOWERS. AS FOR HIGHS READINGS WILL BE COOLER THIS
AFTN WITH TEMPS IN THE UPPER 40S TO LOWER 50S ACROSS NERN CO.
AS FOR HIGH WIND THREAT OVERALL THERE IS NEVER REALLY MUCH OF A MTN
WAVE FOR ANY EXTENDED PERIOD OF TIME TODAY OR TONIGHT. THUS DON`T
EXPECT ANY WIDESPREAD HIGH WINDS ALTHOUGH THERE COULD BE A FEW
BRIEF HIGHER GUSTS IN THE NORMAL WINDY AREAS IN AND NR THE
FOOTHILLS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM MST SUN FEB 14 2016
MODELS HAVE STRONG NORTHWESTERLY FLOW ALOFT FOR THE FORECAST AREA
MONDAY THROUGH TUESDAY NIGHT. JET LEVEL SPEEDS ARE 80 TO 110
KNOTS ALL FOUR PERIODS. THE QG VERTICAL VELOCITY FIELDS HAVE WEAK
DOWNWARD SYNOPTIC SCALE ENERGY FOR THE CWA ALL FOUR PERIODS. THE
BOUNDARY LAYER FLOW LOOKS TO BE DOMINATED BY DOWNSLOPING THROUGH
TUESDAY NIGHT. FOR MOISTURE...THERE IS SOME PROGGED OVER THE HIGH
MOUNTAINS MONDAY INTO MONDAY EVENING...THEN IT DECREASES. THERE IS
SOME OVER THE PLAINS...MOSTLY IN THE UPPER AND MID LEVELS MONDAY.
TUESDAY AND TUESDAY NIGHT ARE PRETTY DRY IN ALL AREAS. THE QPF
FIELDS SHOWS LIMITED SNOWFALL IN THE HIGH MOUNTAINS MONDAY AND
MONDAY NIGHT. FOR POPS...NOTHING FOR THE PLAINS...TO DRY AND
DOWNSLOPING. FOR THE MOUNTAINS...THERE IS SOME MOISTURE MONDAY AND
MONDAY NIGHT AS WELL AS HELP WITH OROGRAPHICS...HOWEVER...
MOISTURE DECREASES SLOWLY THROUGH THOSE TWO PERIODS...THERE IS
SLIGHT WARM AIR ADVECTION...AND NO HELP FROM SYNOPTIC SCALE LIFT.
CURRENT GFE GRIDS HAVE 50-80% POPS IN THE HIGH MOUNTAINS MONDAY
AND MONDAY NIGHT...THIS LOOK REASONABLE. SNOWFALL AMOUNTS WILL BE
HIGHEST IN ZONE 31...BUT HIGHLIGHT CRITERIA AMOUNTS ARE UNLIKELY.
FOR TEMPERATURES...MONDAY`S HIGHS ARE 1-3 C WARMER THAN TODAY`S.
TUESDAY HIGHS ARE 1-2 C WARMER THAN MONDAY`S. FOR THE LATER DAYS
...WEDNESDAY THROUGH SATURDAY...AN UPPER RIDGE MOVES ACROSS
WEDNESDAY INTO EARLY THURSDAY. A WEAK UPPER TROUGH THEN PUSHES
THROUGH BY FRIDAY MORNING. FLAT UPPER RIDGE RETURNS THROUGH EARLY
SATURDAY. ZONAL FLOW IS PROGGED DON SATURDAY. THERE MAY BE ENOUGH
ENERGY AND MOISTURE FOR LIMITED MOUNTAIN POPS THURSDAY AFTERNOON
INTO EARLY FRIDAY. TEMPERATURES WILL STAY ABOVE SEASONAL NORMALS
ALL FOUR DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 955 AM MST SUN FEB 14 2016
WESTERLY WINDS HAVE FINALLY TAKEN HOLD OF THE DENVER METRO AREA
WITH THE MTN WAVE AND LEE TROUGH MOVING OFF AND AWAY FROM THE
FRONT RANGE. CANNOT DISCOUNT OCCASIONAL S-SELY WINDS AT KAPA AND
KDEN NEXT HOUR OR TWO...BUT PREVAILING WIND SHOULD BE W-NWLY.
CLOSE TO THE FOOTHILLS...WINDS AT KBJC SHOULD STAY W-NWLY REST OF
THE DAY AND AT TIMES QUITE STRONG WITH PEAK GUSTS POTENTIALLY TO
AROUND 40KTS. WIND SPEEDS NOT LIKELY TO BE AS STRONG AT KDEN AND
KAPA BUT GUSTS TO 30 KTS OR SO NOT OUT OF THE QUESTION THIS
AFTERNOON. NO PRECIP TODAY AND CIGS SHOULD REMAIN ABOVE 7000 FEET
AGL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM MST MONDAY FOR COZ034.
WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ031-033.
&&
$$
UPDATE...BAKER
SHORT TERM...RPK
LONG TERM...RJK
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
416 PM EST SUN FEB 14 2016
.SYNOPSIS...
A SURFACE RIDGE EXTENDING THROUGH THE FORECAST AREA TODAY WILL
SHIFT OFF THE COAST TONIGHT. A WARM FRONT WILL DEVELOP SOUTH OF
THE FORECAST AREA TONIGHT. THE FRONT WILL LIFT NORTHWARD AND INTO
THE AREA MONDAY AHEAD OF A COLD FRONT. THE COLD FRONT WILL MOVE
THROUGH THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
COLD AND DRY HIGH PRESSURE CENTERED OVER NEW ENGLAND CONTINUES TO
RIDGE INTO THE SOUTHEASTERN STATES WITH DEWPOINTS IN THE SINGLE
DIGITS ACROSS THE FORECAST AREA. INCREASING CLOUDS THROUGH THE DAY
HAVE LIMITED TEMPERATURES THIS AFTERNOON. CLOUDS EXPECTED TO
CONTINUE TO INCREASE THROUGH THE NIGHT AS LOW LEVEL FLOW BECOMES
MORE SOUTHEASTERLY OFF THE ATLANTIC AFTER 00Z AND WEAK ISENTROPIC
UPGLIDE OVERSPREADS THE COLD DOME OF HIGH PRESSURE IN PLACE. THE
CLOUD COVER WILL ACTUALLY HELP TEMPERATURES REMAIN SOMEWHAT STEADY
OVERNIGHT ALTHOUGH PERSISTENT NORTHEASTERLY FLOW WILL USHER IN
SOME COOLER AIR ACROSS THE NORTHERN MIDLANDS AS AN IN SITU COLD
AIR DAMMING WEDGE DEVELOPS. MOISTURE WILL REMAIN VERY SHALLOW IN
THE LOWEST 4000-5000FT WITH DRY AIR ALOFT AND NO MOISTURE IN THE
SNOW GROWTH AREA. NO DYNAMICAL FORCING OVERNIGHT WITH THE ONLY
LIFT OCCURRING FROM ISENTROPIC UPGLIDE. THINK MUCH OF ANY
PRECIPITATION OVERNIGHT WILL FALL AS VIRGA AND GO INTO SATURATING
THE NEAR SURFACE LAYER WITH LITTLE IF ANY REACHING THE GROUND.
POPS INCREASE AFTER 06Z INTO THE CHANCE RANGE BY EARLY MORNING AND
SOUNDINGS INDICATE PREDOMINATE PTYPE WOULD BE FREEZING
RAIN/DRIZZLE BUT MINIMAL IMPACTS EXPECTED.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MODEL FORECAST THERMAL PROFILES CONTINUE TO SUPPORT VERY LIGHT
FREEZING RAIN/DRIZZLE MAINLY ALONG AND NORTH OF A LINE FROM
MANNING TO AIKEN TO MCCORMICK DURING THE 12Z-15Z TIME FRAME
BEFORE SURFACE TEMPS BEGIN TO WARM ABOVE FREEZING FROM SOUTHEAST
TO NORTHWEST AS STRONG WARM ADVECTION AHEAD OF THE APPROACHING
SYSTEM ERODES THE WEDGE. CANNOT RULE OUT A TRACE OF ICE
ACCUMULATION ACROSS THE NORTHERN MIDLANDS AND AFTER COLLABORATION
WITH NEIGHBORING OFFICES DECIDED TO POST A FREEZING RAIN ADVISORY
FOR LANCASTER AND CHESTERFIELD COUNTIES ENDING AT 17Z. THINK
IMPACTS WILL BE MINIMAL WITH ANY ICING OCCURRING ON ELEVATED
SURFACES AND THERE IS A POSSIBILITY THAT LITTLE ACCUMULATION
OCCURS AT ALL GIVEN THE LACK OF DEEPER MOISTURE AVAILABLE.
CHANCES OF RAIN INCREASE THROUGH THE AFTERNOON INTO EVENING AS THE
UPPER TROUGH AMPLIFIES TO OUR WEST AND UPPER FORCING/ASCENT
INCREASE FROM WEST TO EAST. GENERALLY EXPECT A LULL IN PRECIP FROM
MID MORNING THROUGH LATE AFTERNOON AND THEN POPS RAMP UP TO
CATEGORICAL OVERNIGHT. POTENTIAL FOR PERIODS OF HEAVY RAIN AS
STRONG SOUTHERLY 50-55KT LOW LEVEL JET PROVIDES AMPLE MOISTURE
TRANSPORT INTO THE REGION. CANNOT RULE OUT AN ISOLATED ELEVATED
THUNDERSTORM AS LAPSE RATES BECOME STEEP AND CROSS TOTALS REMAIN
HIGH...ALTHOUGH SURFACE BASED INSTABILITY IS RELATIVELY
NON-EXISTENT. AVERAGE RAINFALL AMOUNTS COULD RANGE FROM A QUARTER
INCH TO AS MUCH AS 0.75 INCHES DUE TO INCREASED FORCING AS THE
UPPER TROUGH TAKES A NEGATIVE TILT.
NON STANDARD TEMPERATURE TREND EXPECTED WITH TEMPS RISING LATE
AFTERNOON AND OVERNIGHT MONDAY NIGHT DUE TO WARM ADVECTION AHEAD
OF THE SURFACE LOW. BREEZY CONDITIONS ALSO LIKELY AND A LAKE WIND
ADVISORY MAY BE NEEDED.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SHORTWAVE TROUGH EMBEDDED IN THE UPPER TROUGH OVER THE EASTERN
PART OF THE COUNTRY WILL EJECT EAST ACROSS THE FORECAST AREA TUESDAY
MORNING. THIS WILL DRIVE A COLD FRONT EAST THROUGH THE FORECAST AREA
EARLY TUESDAY. THE GFS MOVES THE MOISTURE OUT OF THE AREA MORE
QUICKLY THAN THE NAM AND IS WARMER WITH HIGH TEMPERATURES ON
TUESDAY. LEANED TOWARD THE GFS AND HAVE POPS GRADUALLY DECREASING
AFTER 12Z AND POPS LESS THAN 15 BY 18Z. THE MODELS CONTINUE TO SHOW
MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH ANOTHER MID-LEVEL
SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY
NIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN US
BEHIND THE FRONT WITH A MUCH DRIER AIRMASS RETURNING THROUGH THE
END OF THE WORK WEEK. SURFACE LOW PRESSURE OVER SOUTHEASTERN
CANADA IS EXPECTED TO BRING THE NEXT FRONTAL BOUNDARY NEAR THE
AREA THIS WEEKEND. TEMPERATURES WILL GENERALLY BE NEAR TO ABOVE
NORMAL THROUGH THE LONG TERM PERIOD WITH HIGHS IN THE UPPER 50S TO
60S AND LOWS IN THE 30S AND 40S.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
MVFR CIGS DEVELOPING ACROSS THE TAF SITES THIS EVENING.
SURFACE HIGH PRESSURE RIDGING INTO THE REGION FROM THE NORTHEAST
WILL MOVE OFF THE COAST TONIGHT. MOISTURE AND ISENTROPIC LIFT
WILL INCREASE ACROSS THE AREA LATE TONIGHT WITH A SLIGHT CHANCE
OF RAIN AT AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING
JUST BEFORE DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE
THROUGH THE MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...
THE THREAT OF ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT
MENTION OF PRECIP DUE TO LOW CONFIDENCE IN TIMING AND MINIMAL IF
ANY VISIBILITY IMPACTS.
CLOUDS ARE EXPECTED TO INCREASE AND LOWER TO MVFR THIS EVENING
AS ONSHORE FLOW PROMOTES WEDGE DEVELOPMENT. THE HRRR IS MORE
PESSIMISTIC THAN MOST OF THE OTHER GUIDANCE AND TAKES THE CEILINGS
DOWN TO IFR OVERNIGHT. WINDS WILL BE EASTERLY 10 KNOTS OR LESS.
NO FOG EXPECTED TO DEVELOP LATE TONIGHT DUE TO WIND AND CLOUDS.
EXTENDED AVIATION OUTLOOK...CIG/VSBY RESTRICTIONS POSSIBLE MONDAY AFTERNOON
INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM CROSSES
THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT INTO TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FREEZING RAIN ADVISORY FROM 1 AM TO NOON EST MONDAY FOR SCZ015-
016.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
317 PM EST SUN FEB 14 2016
.SYNOPSIS...
A SURFACE RIDGE EXTENDING THROUGH THE FORECAST AREA TODAY WILL
SHIFT OFF THE COAST TONIGHT. A WARM FRONT WILL DEVELOP SOUTH OF
THE FORECAST AREA TONIGHT. THE FRONT WILL LIFT NORTHWARD AND INTO
THE AREA MONDAY AHEAD OF A COLD FRONT. THE COLD FRONT WILL MOVE
THROUGH THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLD AND DRY HIGH PRESSURE CENTERED OVER NEW ENGLAND CONTINUES TO
RIDGE INTO THE SOUTHEASTERN STATES WITH DEWPOINTS IN THE SINGLE
DIGITS ACROSS THE FORECAST AREA. INCREASING CLOUDS THROUGH THE DAY
HAVE LIMITED TEMPERATURES THIS AFTERNOON. CLOUDS EXPECTED TO
CONTINUE TO INCREASE THROUGH THE NIGHT AS LOW LEVEL FLOW BECOMES
MORE SOUTHEASTERLY OFF THE ATLANTIC AFTER 00Z AND WEAK ISENTROPIC
UPGLIDE OVERSPREADS THE COLD DOME OF HIGH PRESSURE IN PLACE. THE
CLOUD COVER WILL ACTUALLY HELP TEMPERATURES REMAIN SOMEWHAT STEADY
OVERNIGHT ALTHOUGH PERSISTENT NORTHEASTERLY FLOW WILL USHER IN
SOME COOLER AIR ACROSS THE NORTHERN MIDLANDS AS AN IN SITU COLD
AIR DAMMING WEDGE DEVELOPS. MOISTURE WILL REMAIN VERY SHALLOW IN
THE LOWEST 4000-5000FT WITH DRY AIR ALOFT AND NO MOISTURE IN THE
SNOW GROWTH AREA. NO DYNAMICAL FORCING OVERNIGHT WITH THE ONLY
LIFT OCCURRING FROM ISENTROPIC UPGLIDE. THINK MUCH OF ANY
PRECIPITATION OVERNIGHT WILL FALL AS VIRGA AND GO INTO SATURATING
THE NEAR SURFACE LAYER WITH LITTLE IF ANY REACHING THE GROUND.
POPS INCREASE AFTER 06Z INTO THE CHANCE RANGE BY EARLY MORNING AND
SOUNDINGS INDICATE PREDOMINATE PTYPE WOULD BE FREEZING
RAIN/DRIZZLE BUT MINIMAL IMPACTS EXPECTED.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
MODEL FORECAST THERMAL PROFILES CONTINUE TO SUPPORT VERY LIGHT
FREEZING RAIN/DRIZZLE MAINLY ALONG AND NORTH OF A LINE FROM
MANNING TO AIKEN TO MCCORMICK DURING THE 12Z-15Z TIME FRAME
BEFORE SURFACE TEMPS BEGIN TO WARM ABOVE FREEZING FROM SOUTHEAST
TO NORTHWEST AS STRONG WARM ADVECTION AHEAD OF THE APPROACHING
SYSTEM ERODES THE WEDGE. CANNOT RULE OUT A TRACE OF ICE
ACCUMULATION ACROSS THE NORTHERN MIDLANDS AND AFTER COLLABORATION
WITH NEIGHBORING OFFICES DECIDED TO POST A FREEZING RAIN ADVISORY
FOR LANCASTER AND CHESTERFIELD COUNTIES ENDING AT 17Z. THINK
IMPACTS WILL BE MINIMAL WITH ANY ICING OCCURRING ON ELEVATED
SURFACES AND THERE IS A POSSIBILITY THAT LITTLE ACCUMULATION
OCCURS AT ALL GIVEN THE LACK OF DEEPER MOISTURE AVAILABLE.
CHANCES OF RAIN INCREASE THROUGH THE AFTERNOON INTO EVENING AS THE
UPPER TROUGH AMPLIFIES TO OUR WEST AND UPPER FORCING/ASCENT
INCREASE FROM WEST TO EAST. GENERALLY EXPECT A LULL IN PRECIP FROM
MID MORNING THROUGH LATE AFTERNOON AND THEN POPS RAMP UP TO
CATEGORICAL OVERNIGHT. POTENTIAL FOR PERIODS OF HEAVY RAIN AS
STRONG SOUTHERLY 50-55KT LOW LEVEL JET PROVIDES AMPLE MOISTURE
TRANSPORT INTO THE REGION. CANNOT RULE OUT AN ISOLATED ELEVATED
THUNDERSTORM AS LAPSE RATES BECOME STEEP AND CROSS TOTALS REMAIN
HIGH...ALTHOUGH SURFACE BASED INSTABILITY IS RELATIVELY
NON-EXISTENT. AVERAGE RAINFALL AMOUNTS COULD RANGE FROM A QUARTER
INCH TO AS MUCH AS 0.75 INCHES DUE TO INCREASED FORCING AS THE
UPPER TROUGH TAKES A NEGATIVE TILT.
NON STANDARD TEMPERATURE TREND EXPECTED WITH TEMPS RISING LATE
AFTERNOON AND OVERNIGHT MONDAY NIGHT DUE TO WARM ADVECTION AHEAD
OF THE SURFACE LOW. BREEZY CONDITIONS ALSO LIKELY AND A LAKE WIND
ADVISORY MAY BE NEEDED.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SHORTWAVE TROUGH EMBEDDED IN THE UPPER TROUGH OVER THE EASTERN
PART OF THE COUNTRY WILL EJECT EAST ACROSS THE FORECAST AREA TUESDAY
MORNING. THIS WILL DRIVE A COLD FRONT EAST THROUGH THE FORECAST AREA
EARLY TUESDAY. THE GFS MOVES THE MOISTURE OUT OF THE AREA MORE
QUICKLY THAN THE NAM AND IS WARMER WITH HIGH TEMPERATURES ON
TUESDAY. LEANED TOWARD THE GFS AND HAVE POPS GRADUALLY DECREASING
AFTER 12Z AND POPS LESS THAN 15 BY 18Z. THE MODELS CONTINUE TO SHOW
MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH ANOTHER MID-LEVEL
SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY
NIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN US
BEHIND THE FRONT WITH A MUCH DRIER AIRMASS RETURNING THROUGH THE
END OF THE WORK WEEK. SURFACE LOW PRESSURE OVER SOUTHEASTERN
CANADA IS EXPECTED TO BRING THE NEXT FRONTAL BOUNDARY NEAR THE
AREA THIS WEEKEND. TEMPERATURES WILL GENERALLY BE NEAR TO ABOVE
NORMAL THROUGH THE LONG TERM PERIOD WITH HIGHS IN THE UPPER 50S TO
60S AND LOWS IN THE 30S AND 40S.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THROUGH MOST OF THE PERIOD WITH MVFR CEILINGS
DEVELOPING TONIGHT INTO MONDAY.
DRY SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE
FORECAST AREA FROM THE NORTHEAST THIS AFTERNOON BEFORE SHIFTING
OFF THE COAST TONIGHT. MOISTURE AND ISENTROPIC LIFT WILL INCREASE
ACROSS THE AREA LATE TONIGHT WITH A SLIGHT CHANCE OF RAIN AT
AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING JUST BEFORE
DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE
MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF
ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP
IN CURRENT ISSUANCE DUE TO LOW CONFIDENCE IN TIMING. RAIN IS
EXPECTED TO BE LIGHT SO EXPECT ONLY MINIMAL IF ANY VISIBILITY
IMPACTS. CLOUDS ARE EXPECTED TO INCREASE AND LOWER TO MVFR LATE
TONIGHT/EARLY MONDAY AS ONSHORE FLOW PROMOTES WEDGE DEVELOPMENT.
THE HRRR IS MORE PESSIMISTIC THAN MOST OF THE OTHER GUIDANCE AND
TAKES THE CEILINGS DOWN TO IFR OVERNIGHT. WINDS WILL BE OUT OF THE
ENE THROUGH THE PERIOD AT AROUND 10 KNOTS OR LESS. NO FOG EXPECTED
TO DEVELOP LATE TONIGHT DUE TO WIND AND INCREASING CLOUDS.
EXTENDED AVIATION OUTLOOK...CIG/VSBY RESTRICTIONS POSSIBLE MONDAY INTO
TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM CROSSES
THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FREEZING RAIN ADVISORY FROM 1 AM TO NOON EST MONDAY FOR SCZ015-
016.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1244 PM EST SUN FEB 14 2016
.SYNOPSIS...
A SURFACE RIDGE EXTENDING THROUGH THE FORECAST AREA TODAY WILL
SHIFT OFF THE COAST TONIGHT. A WARM FRONT WILL DEVELOP SOUTH OF
THE FORECAST AREA TONIGHT. THE FRONT WILL LIFT NORTHWARD AND INTO
THE AREA MONDAY AHEAD OF A COLD FRONT. THE COLD FRONT WILL MOVE
THROUGH THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...SURFACE HIGH PRESSURE CENTERED OVER NEW ENGLAND THIS
MORNING CONTINUES TO RIDGE INTO THE SOUTHEASTERN STATES USHERING
IN COOL AND DRY AIR OVER THE FORECAST AREA. DEWPOINTS REMAIN VERY
LOW FROM AROUND 0 TO 5 DEGREES ACROSS THE MIDLANDS AND CSRA.
SATELLITE IMAGERY SHOWS AN AREA OF MID LEVEL CLOUDS EXTENDING
ACROSS THE UPSTATE INTO THE NORTHERN AND CENTRAL
MIDLANDS...ALTHOUGH THEY HAVE BEEN ERODING ON THE EASTERN SIDE.
THIS HAS SLOWED THE TEMPERATURES FROM RISING AS FAST COMPARED TO
AREAS TO THE SOUTH AND HAVE UPDATED HOURLY TEMP GRIDS TO ACCOUNT
FOR THE LARGER DIFFERENCE. TEMPERATURES STILL ON TRACK TO RISE
INTO THE MID 40S ACROSS THE CSRA BUT WILL STRUGGLE THROUGH THE 30S
ACROSS THE NORTHERN MIDLANDS. SOME LIGHT VIRGA SHOWING UP REGIONAL
RADAR ACROSS WESTERN NORTH CAROLINA BUT NO STATIONS ARE REPORTING
ANY PRECIPITATION WITH SO MUCH DRY AIR IN PLACE ABOVE THE SURFACE.
DO NOT EXPECT ANY PRECIPITATION TO REACH THE GROUND THIS
AFTERNOON.
TONIGHT...THE RIDGE WILL SHIFT OFF THE COAST AND A LOW-LEVEL
ONSHORE FLOW WILL DEVELOP IN THE FORECAST AREA. THE MODELS SHOW AN
INVERTED TROUGH OR WARM FRONT DEVELOPING NEAR THE COAST.
HOWEVER...THERE IS CONSISTENCY WITH DEEPER MOISTURE REMAINING
NORTHWEST OF THE FORECAST AREA WELL AHEAD OF AN UPPER TROUGH.
LOW-LEVEL MOISTURE AND ISENTROPIC LIFT WILL RESULT IN A
POSSIBILITY OF PRECIPITATION DEVELOPING BUT WITH SHALLOW MOISTURE
AND LITTLE UPPER-LEVEL LIFT AMOUNTS SHOULD BE LIGHT. THE
NAM...GFS...ECMWF AND NEARLY ALL SREF MEMBERS SHOW VERY LITTLE
QPF...MAINLY NEAR 0.01 OF AN INCH. THE ARW AND SPC WRF KEEP
SIGNIFICANT PRECIPITATION NORTHWEST OF THE FORECAST AREA
OVERNIGHT. THE TEMPERATURE GUIDANCE WAS CONSISTENT IN THE NORTH
PART OF THE FORECAST AREA...BUT THE NAM WAS COLDER IN THE SOUTH
SECTION. WE USED A GUIDANCE CONSENSUS FOR THE TEMPERATURE
FORECAST. MODEL FORECAST SOUNDINGS INDICATE FREEZING RAIN AS THE
PREDOMINATE PRECIPITATION TYPE FOR ALL BUT THE EXTREME SOUTHEAST
SECTION. A WINTER WEATHER ADVISORY FOR LIGHT FREEZING RAIN MAY BE
NEEDED FOR LATE TONIGHT.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
THE NAM...GFS...AND ECMWF DISPLAY AN ONSHORE FLOW INTO THE
FORECAST AREA WITH A WARM FRONT LIFTING NORTHWARD AND INTO THE
AREA MONDAY. PRECIPITATION MAY OCCUR MAINLY ASSOCIATED WITH
ISENTROPIC LIFT. LITTLE UPPER-LEVEL LIFT IS INDICATED. THE MODELS
HAVE SHALLOW MOISTURE AND LIGHT PRECIPITATION AMOUNTS. THE
NAM...GFS...AND ECMWF HAVE QPF AROUND 0.01 OF AN INCH MONDAY
MORNING...AND 0.01 TO 0.1 OF AN INCH MONDAY AFTERNOON. MODEL
FORECAST SOUNDINGS INDICATE A PREDOMINATE PRECIPITATION TYPE OF
FREEZING RAIN EXCEPT IN THE EXTREME SOUTHEAST PART. THE FREEZING
RAIN THREAT SHOULD DIMINISH FROM SOUTH TO NORTH AS THE WARM FRONT
LIFTS NORTHWARD. USED AN AVERAGE OF THE NAM AND GFS FOR THE
TIMING. THE NAM WAS SLOWER ERODING THE COLDEST AIR AND MAY BE
CORRECT BECAUSE OF THE WEDGE PATTERN BUT THE MODEL HAS HAD A COLD
BIAS OF LATE. BASED ON THE MODEL AGREEMENT WITH LITTLE QPF AND
EXPECTED SHALLOW MOISTURE WE HAVE NOT POSTED A WINTER STORM WATCH
BECAUSE THE CHANCE OF 0.25 OF AN INCH OF ICE WAS TOO LOW.
HOWEVER...A WINTER WEATHER ADVISORY MAY BE NEEDED.
TEMPERATURES SHOULD BE ABOVE FREEZING MONDAY NIGHT WITH WARMING
AHEAD OF THE APPROACHING COLD FRONT. THE BULK OF THE RAINFALL
SHOULD OCCUR MONDAY NIGHT ASSOCIATED WITH CONVERGENCE AHEAD OF THE
COLD FRONT...STRONG H85 JET...AND H5 SHORTWAVE TROUGH. THE MODELS
DISPLAY QPF OF 0.25 TO 1 INCH WITH THE NAM AND ECMWF SHOWING THE
GREATER AMOUNTS. WE LEANED TOWARD THE HIGHER VALUES BASED ON THE
MODEL CONSISTENCY OF A 50-KNOTS H85 JET. THE NAM MAINTAINS
SURFACE-BASED STABILITY WITH LI/S ABOVE ZERO. HOWEVER...A FEW
ELEVATED THUNDERSTORMS MAY OCCUR WITH CROSS TOTALS FORECAST IN THE
MID AND UPPER 20S. EXPECT RISING TEMPERATURES MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE MODELS DISPLAY DRYING BEHIND THE COLD FRONT AND H5 SHORTWAVE
TROUGH FOR TUESDAY. WE HAVE FORECASTED A DIMINISHED SHOWER CHANCE.
FOLLOWED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. THE
MODELS SHOW MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH A MID-
LEVEL SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA
TUESDAY NIGHT. THE MODELS DEPICT DRY RIDGING DOMINATING DURING THE
MEDIUM-RANGE PERIOD. THE GFS...ECMWF...AND EKD MOS HAVE NEAR OR
ABOVE NORMAL TEMPERATURES WITH POPS LESS THAN 20 PERCENT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THROUGH MOST OF THE PERIOD WITH MVFR CEILINGS
DEVELOPING TONIGHT INTO MONDAY.
DRY SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE
FORECAST AREA FROM THE NORTHEAST THIS AFTERNOON BEFORE SHIFTING
OFF THE COAST TONIGHT. MOISTURE AND ISENTROPIC LIFT WILL INCREASE
ACROSS THE AREA LATE TONIGHT WITH A SLIGHT CHANCE OF RAIN AT
AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING JUST BEFORE
DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE
MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF
ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP
IN CURRENT ISSUANCE DUE TO LOW CONFIDENCE IN TIMING. RAIN IS
EXPECTED TO BE LIGHT SO EXPECT ONLY MINIMAL IF ANY VISIBILITY
IMPACTS. CLOUDS ARE EXPECTED TO INCREASE AND LOWER TO MVFR LATE
TONIGHT/EARLY MONDAY AS ONSHORE FLOW PROMOTES WEDGE DEVELOPMENT.
THE HRRR IS MORE PESSIMISTIC THAN MOST OF THE OTHER GUIDANCE AND
TAKES THE CEILINGS DOWN TO IFR OVERNIGHT. WINDS WILL BE OUT OF THE
ENE THROUGH THE PERIOD AT AROUND 10 KNOTS OR LESS. NO FOG EXPECTED
TO DEVELOP LATE TONIGHT DUE TO WIND AND INCREASING CLOUDS.
EXTENDED AVIATION OUTLOOK...CIG/VSBY RESTRICTIONS POSSIBLE MONDAY INTO
TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM CROSSES
THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
251 PM CST SUN FEB 14 2016
.SHORT TERM...(Tonight)
ISSUED AT 251 PM CST SUN FEB 14 2016
Will continue the Winter Weather Advisory until 6 pm across CWA.
Between 2-4 inches of snow has fallen across much of central and
southeast IL so far today, with the highest amounts from Galesburg
to Lincoln and Decatur southwest to Springfield and Taylorville.
Less than 1 inch of additional snow expected east of I-57 and from I-
74 north where light snow lingers longest into late afternoon and
early evening. Some patchy freezing drizzle to develop from west to
east during late afternoon and into tonight as we lose mid level
cloud layer. Vigorous 539 dm 500 mb low over far nw IL will track
into ne IL by early evening and into Lake Erie overnight with a
lingering short wave trof hanging back over the Midwest into Monday.
This should keep low clouds around along with trace amounts of
precipitation (very light snow/flurries and patchy freezing drizzle
especially this evening). Temperatures will be nearly steady
tonight mostly in the low to mid 20s. Brisk southeast winds 10-20
mph and gusts to 25 mph this afternoon to diminish to 5-10 mph
overnight and veer more southerly.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 251 PM CST SUN FEB 14 2016
Monday is apt to be a mostly quiet day, with temperatures climbing
back toward normal for mid-February. Some model guidance continues
to suggest very light rain/snow falling across the western or
southern portion of the forecast area by afternoon as a weak short
wave crosses the region. However, the already weak wave is
diminishing further as it shears into the mean upper trof, and
really do not expect measurable precipitation with this feature.
Maintained a Slight Chance afternoon PoP for continuity and to blend
with our neighbors, but feel these PoPs can probably be dropped if
models continue to look as they do now.
The forecast for late Monday night into Tuesday remains problematic
as model guidance continues to show notable differences in the
timing/track of a clipper system. Run to run consistency with this
system has been a problem too. Blended guidance still suggests
temperatures warming enough by afternoon for most of the
precipitation to change to rain. However, faster solutions suggest
most, if not all, of the precipitation will have fallen by then.
Thermal profiles support all snow during the Monday night and most
of Tuesday morning hours, so it is looking increasingly likely that
at least minor snow accumulation can be expected with this system.
For now, have most locations seeing around 1" total, but this will
obviously need to be tweaked as the models come to a stronger
consensus in the next few runs.
Whatever snow we do get Tuesday will not be around long as upper
heights rise and southerly low level flow develops heading into the
end of the week. These factors support temperatures rising to well
above normal levels, with highs by Friday topping out around 60
across most of the forecast area. A cold front coming through
Friday/Friday night may have rainfall associated with it, but it
does not appear likely to be significant. Behind the cold front,
temperatures remain above normal, with the mean flow coming in off
the Pacific coast. Another disturbance within this zonal flow may
bring additional rainfall by the end of the weekend, but expected
differences (at this time range) in timing/track of this system
exist.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1159 AM CST SUN FEB 14 2016
Light to moderate snow that has been bringing vsbys down to
1/4-3/4 mile along with ceilings between 500-1500 ft across
central IL past few hours. The back edge of this snow was along a
Burlington, IA to Jacksonville line and HRRR has the snow
diminishing eastward toward the IN border by 21Z. But there is
some wrap around light snow over central/se IA that will affect
northern TAF sites along I-74 through dusk. Could see some patchy
freezing drizzle develop from west to east during late afternoon
and into the evening but coverage too limited to mention at this
time. SE winds 10-17 kts and gusts of 18-25 kts this afternoon to
diminish to around 10 kts this evening and then 5-8 kts overnight
and veer SSE. SSW winds 5-9 kts expected Monday morning. Kept low
clouds of MVFR to IFR around tonight into Monday morning with
vsbys becoming MVFR later this afternoon as snow diminishing and
continues MVFR vsbys with some fog/low level moisture tonight and
linger into Monday morning as winds become lighter.
&&
.ILX Watches/Warnings/Advisories...
Winter Weather Advisory until 6 PM CST this evening for
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...07
LONG TERM...BAK
AVIATION...07
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1159 AM CST SUN FEB 14 2016
.UPDATE...
ISSUED AT 1045 AM CST SUN FEB 14 2016
Updated the forecast to address snowfall today and will continue
the winter weather advisory across CWA through 6 pm today. Second
and larger band of light to moderate snow had spread east across
IL by late this morning, with back edge of this snow just west of
CWA. Though more wrap around mainly light snows were over central
and eastern IA and will spread across northern CWA during the
afternoon, keeping them in the snow longer and also higher total
snowfall amounts of 3-4 inches. Central and southeast CWA to see
an additional 1-3 inches rest of today with total of 2-3 inches,
though heavier bands of snow from Springfield south to Litchfield
and east toward Taylorville and Shelbyville. Southeast winds of
10-20 mph and gusts to around 25 mph to continue some blowing and
drifting snow. Temps at 1030 am were in the upper teens and lower
20s. Highs this afternoon in the mid to upper 20s look on track.
540 dm 500 mb low over east central Iowa to track into northern/ne
IL by 00Z/6 pm today and then into nw Ohio by 06Z/midnight
tonight. This feature associated with the wrap around snows in
central/eastern IA that moves across the northern CWA during the
afternoon. Otherwise back edge of snow to spread eastward across
central/se IL during the afternoon and some patchy freezing
drizzle appears in sw CWA late this afternoon and rest of CWA
during tonight as we lose mid level clouds.
&&
.SHORT TERM...(Today)
ISSUED AT 324 AM CST SUN FEB 14 2016
08z/2am water vapor imagery shows a vigorous short-wave trough over
eastern Nebraska. A narrow band of snow has developed well in
advance of this feature across the central sections of Iowa and
Illinois in association with strong 700-500mb layer frontogenesis.
Latest radar imagery/surface obs show the snow band centered along a
Galesburg...to Lincoln...to Marshall line. This band is expected to
gradually lift northward over the next few hours, as frontogenetic
forcing shifts northward and weakens. Snowfall of one half inch or
less will be likely with this initial burst of snow early this
morning. The main precip event will hold off until later this
morning as stronger/more widespread synoptic lift associated with
the short-wave arrives. HRRR seems to be handling the current
precip field better than any other model, so have followed its
solution closely in the short-term. It shows snow rapidly
developing in advance of the approaching wave and spreading eastward
into central Illinois between 15z and 18z. Based on speed of wave,
a 4-5 hour period of light to moderate snow is expected from late
morning through mid-afternoon before the precip begins to diminish
from west to east late in the day. Total snowfall still appears to
be 2-3 inches across most areas, with the highest totals of 4-5
inches focused along/northwest of the Illinois River. Will continue
the Winter Weather Advisory through 6pm accordingly.
.LONG TERM...(Tonight through Saturday)
ISSUED AT 324 AM CST SUN FEB 14 2016
All models show the strongest lift quickly shifting east of the area
late this afternoon into the early evening, suggesting a rapid end
to the accumulating snow. Will linger chance PoPs across the north
and east through the evening, then will go dry across the board
overnight. Forecast soundings show a loss of ice crystals within
the profile, resulting in a period of light freezing drizzle as the
precip ends.
Monday still appears to be a cool and mostly dry day: however, a few
of the models are showing some light precip with another short-wave
skirting through the area. The GFS is the most bullish with precip,
while the NAM and ECMWF show very little. Given presence of at
least weak lift, will carry slight chance PoPs for rain/snow across
the southern half of the KILX CWA Monday afternoon.
A more significant wave will push into the region on Tuesday,
bringing another round of light precip. Models generally track the
500mb vort max right across central Illinois, resulting in most of
the precip being focused across the northern half of Illinois.
Thermal profiles will be cold enough to support snow initially late
Monday night into Tuesday morning: however, as temperatures climb
into the upper 30s and lower 40s, the snow will transition to a
rain/snow mix or all rain by Tuesday afternoon. Minor snow
accumulations of 1 inch or less are expected during the morning
before the snow mixes with/changes to rain.
After that, the big weather story for the end of the week will be a
pronounced warming trend as upper-level ridging builds across the
Midwest. High temperatures will reach the upper 40s and lower 50s
on Thursday, then will climb even higher into the upper 50s and
lower 60s by Friday. A weak cold front will push through Illinois
on Friday, with 00z Feb 14 models now pulling back on their QPF.
Will still mention low chance PoPs for rain showers with FROPA on
Friday, followed by a return to mild/dry weather next weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1159 AM CST SUN FEB 14 2016
Light to moderate snow that has been bringing vsbys down to
1/4-3/4 mile along with ceilings between 500-1500 ft across
central IL past few hours. The back edge of this snow was along a
Burlington, IA to Jacksonville line and HRRR has the snow
diminishing eastward toward the IN border by 21Z. But there is
some wrap around light snow over central/se IA that will affect
northern TAF sites along I-74 through dusk. Could see some patchy
freezing drizzle develop from west to east during late afternoon
and into the evening but coverage too limited to mention at this
time. SE winds 10-17 kts and gusts of 18-25 kts this afternoon to
diminish to around 10 kts this evening and then 5-8 kts overnight
and veer SSE. SSW winds 5-9 kts expected Monday morning. Kept low
clouds of MVFR to IFR around tonight into Monday morning with
vsbys becoming MVFR later this afternoon as snow diminishing and
continues MVFR vsbys with some fog/low level moisture tonight and
linger into Monday morning as winds become lighter.
&&
.ILX Watches/Warnings/Advisories...
Winter Weather Advisory until 6 PM CST this evening for
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...07
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1045 AM CST SUN FEB 14 2016
.UPDATE...
ISSUED AT 1045 AM CST SUN FEB 14 2016
Updated the forecast to address snowfall today and will continue
the winter weather advisory across CWA through 6 pm today. Second
and larger band of light to moderate snow had spread east across
IL by late this morning, with back edge of this snow just west of
CWA. Though more wrap around mainly light snows were over central
and eastern IA and will spread across northern CWA during the
afternoon, keeping them in the snow longer and also higher total
snowfall amounts of 3-4 inches. Central and southeast CWA to see
an additional 1-3 inches rest of today with total of 2-3 inches,
though heavier bands of snow from Springfield south to Litchfield
and east toward Taylorville and Shelbyville. Southeast winds of
10-20 mph and gusts to around 25 mph to continue some blowing and
drifting snow. Temps at 1030 am were in the upper teens and lower
20s. Highs this afternoon in the mid to upper 20s look on track.
540 dm 500 mb low over east central Iowa to track into northern/ne
IL by 00Z/6 pm today and then into nw Ohio by 06Z/midnight
tonight. This feature associated with the wrap around snows in
central/eastern IA that moves across the northern CWA during the
afternoon. Otherwise back edge of snow to spread eastward across
central/se IL during the afternoon and some patchy freezing
drizzle appears in sw CWA late this afternoon and rest of CWA
during tonight as we lose mid level clouds.
&&
.SHORT TERM...(Today)
ISSUED AT 324 AM CST SUN FEB 14 2016
08z/2am water vapor imagery shows a vigorous short-wave trough over
eastern Nebraska. A narrow band of snow has developed well in
advance of this feature across the central sections of Iowa and
Illinois in association with strong 700-500mb layer frontogenesis.
Latest radar imagery/surface obs show the snow band centered along a
Galesburg...to Lincoln...to Marshall line. This band is expected to
gradually lift northward over the next few hours, as frontogenetic
forcing shifts northward and weakens. Snowfall of one half inch or
less will be likely with this initial burst of snow early this
morning. The main precip event will hold off until later this
morning as stronger/more widespread synoptic lift associated with
the short-wave arrives. HRRR seems to be handling the current
precip field better than any other model, so have followed its
solution closely in the short-term. It shows snow rapidly
developing in advance of the approaching wave and spreading eastward
into central Illinois between 15z and 18z. Based on speed of wave,
a 4-5 hour period of light to moderate snow is expected from late
morning through mid-afternoon before the precip begins to diminish
from west to east late in the day. Total snowfall still appears to
be 2-3 inches across most areas, with the highest totals of 4-5
inches focused along/northwest of the Illinois River. Will continue
the Winter Weather Advisory through 6pm accordingly.
.LONG TERM...(Tonight through Saturday)
ISSUED AT 324 AM CST SUN FEB 14 2016
All models show the strongest lift quickly shifting east of the area
late this afternoon into the early evening, suggesting a rapid end
to the accumulating snow. Will linger chance PoPs across the north
and east through the evening, then will go dry across the board
overnight. Forecast soundings show a loss of ice crystals within
the profile, resulting in a period of light freezing drizzle as the
precip ends.
Monday still appears to be a cool and mostly dry day: however, a few
of the models are showing some light precip with another short-wave
skirting through the area. The GFS is the most bullish with precip,
while the NAM and ECMWF show very little. Given presence of at
least weak lift, will carry slight chance PoPs for rain/snow across
the southern half of the KILX CWA Monday afternoon.
A more significant wave will push into the region on Tuesday,
bringing another round of light precip. Models generally track the
500mb vort max right across central Illinois, resulting in most of
the precip being focused across the northern half of Illinois.
Thermal profiles will be cold enough to support snow initially late
Monday night into Tuesday morning: however, as temperatures climb
into the upper 30s and lower 40s, the snow will transition to a
rain/snow mix or all rain by Tuesday afternoon. Minor snow
accumulations of 1 inch or less are expected during the morning
before the snow mixes with/changes to rain.
After that, the big weather story for the end of the week will be a
pronounced warming trend as upper-level ridging builds across the
Midwest. High temperatures will reach the upper 40s and lower 50s
on Thursday, then will climb even higher into the upper 50s and
lower 60s by Friday. A weak cold front will push through Illinois
on Friday, with 00z Feb 14 models now pulling back on their QPF.
Will still mention low chance PoPs for rain showers with FROPA on
Friday, followed by a return to mild/dry weather next weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 500 AM CST SUN FEB 14 2016
First wave of snow was pushing into our eastern TAF sites this
morning with a break in the snow through about 15z before another
round of snow and IFR cigs moves in for the rest of the day.
Latest surface observations to our west indicates cigs improve
to low VFR with occasional MVFR cigs/vsbys in very light snow.
However, across western Iowa into northwest Missouri, a band
of light to moderate snow was located and based on the present
movement of the snow, it will push into our western areas between
14z-16z, and over the far eastern TAF sites by 18z. Cigs and Vsbys
will lower to IFR to occasional VLIFR where some of the heavier
bands of snow setup. The snow is expected to taper to flurries
by late afternoon or early this evening and as the precip starts
to edge off to our east, there is the threat for some patchy
freezing drizzle this evening, mainly from 00z-06z. Due to the
patchy nature of the precip this evening, will not include in
the TAFs at this time, but something to keep an eye on with
later forecasts today.
Southeast winds of 12 to 17 kts are expected today with a few
gusts around 23 kts into this afternoon with winds turning
more into a southerly direction tonight with speeds of 10 kts
or less.
&&
.ILX Watches/Warnings/Advisories...
Winter Weather Advisory until 6 PM CST this evening for
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
250 PM EST SUN FEB 14 2016
.UPDATE...
LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 1040 AM EST SUN FEB 14 2016
CENTRAL INDIANA WILL BE UNDER AN ACTIVE WEATHER PATTERN THROUGH
NEXT WEEK AS A SERIES OF DISTURBANCES MOVE THROUGH THE REGION. THE
FIRST WILL START IMPACTING THE AREA THIS MORNING...RESULTING IN 1 TO
4 INCHES OF SNOWFALL BY TONIGHT ACROSS CENTRAL INDIANA. THE SECOND
DISTURBANCE WILL PASS THROUGH ON MONDAY...BUT RAIN MIXING IN WILL
LIMIT SNOW ACCUMULATIONS. YET ANOTHER SYSTEM WILL BRING MIXED
PRECIPITATION ON TUESDAY. FURTHER OUT...A WARM UP CAN BE EXPECTED
DURING THE EXTENDED PERIOD WITH RAIN CHANCES ON FRIDAY.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1034 AM EST SUN FEB 14 2016
CURRENTLY SEEING A LULL IN ACCUMULATING SNOWFALL ACROSS CENTRAL
INDIANA. A RELATIVELY DRY COLUMN HAS KEPT MOST OF THE SNOW THAT
FELL EARLIER THIS MORNING FROM ACCUMULATING EXCEPT IN THE HEAVIEST
BAND WHERE UP TO HALF AN INCH WAS REPORTED. A COMPACT UPPER WAVE
SEEN IN SATELLITE IMAGERY OVER IOWA WILL CONTINUE TO MOVE TOWARD
THE AREA TODAY AND ISENTROPIC LIFT WILL INCREASE FROM THE
SOUTH. RADAR TRENDS AND HI RES GUIDANCE INDICATE ACCUMULATING SNOW
WILL MOVE BACK INTO WESTERN INDIANA STARTING AROUND NOON AND
OVERSPREAD THE AREA FROM THERE. THE LAST FEW RUNS OF BOTH THE RAP
AND HRRR CONTINUE TO INDICATE THE HEAVIEST SNOW WILL FALL ACROSS
THE SOUTHERN COUNTIES AND THEY SHOW A DECENT SWATH OF 2-3 INCHES
FROM AROUND I-70 SOUTH WITH 3-4 INCHES SOUTH OF A BLOOMINGTON TO
COLUMBUS LINE AND PERHAPS EVEN ISOLATED 5 INCH AMOUNTS. BASED ON
THIS HAVE UPPED SNOWFALL AMOUNTS TO 1 TO 3 INCHES IN THE
NORTHEAST...2 TO 3 CENTRAL AND 3 TO 4 SOUTH WITH ISOLATED HIGHER
AMOUNTS. RAP AND HRRR BOTH SHOW HEAVIEST SNOW STARTING AROUND 2-3
PM AND MOVING OUT OF THE AREA BY AROUND 6 PM...BUT HAVE GIVEN THIS
A BIT OF CUSHION ON EITHER SIDE IN THE TIMING IN THE WSW. MADE NO
ADJUSTMENTS TO THE AREAL EXTENT OF THE ADVISORY BUT DID BUMP UP
AMOUNTS AND ADDED TIMING OF HEAVIEST SNOW.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 334 AM EST SUN FEB 14 2016
THE MAIN FOCUS OF THE SHORT TERM PERIOD WILL BE THE REMNANTS OF
THE FIRST SYSTEM FOLLOWED BY ANOTHER DISTURBANCE ON TUESDAY.
ISENTROPIC LIFT ABRUPTLY CUTS OFF ACROSS CENTRAL INDIANA AFTER MON
03Z AS MOISTURE DECREASES. SO...RAPIDLY DECREASED POPS FROM WEST
TO EAST AFTER SUN 06Z WITH JUST A FEW ADDITIONAL TENTHS OF AN INCH
OF SNOW ACCUMULATION OVERNIGHT.
FOCUS THEN TURNS TO THE NEXT UPPER WAVE PROGGED TO MOVE THROUGH ON
MONDAY EVENING. EXPECT A LULL IN ACTIVITY ON MONDAY AFTERNOON WITH
JUST A BRIEF SPIKE IN PRECIPITATION ON MONDAY EVENING AS THAT
UPPER WAVE MOVES THROUGH...BUT MOISTURE APPEARS LIMITED. SO...WILL
ONLY GO WITH SLIGHT CHANCE POPS FOR MONDAY EVENING AND NIGHT.
FINALLY...A THIRD DISTURBANCE WILL TRACK ACROSS THE AREA ON
TUESDAY. THIS WILL BE MORE OF A MIXED PRECIPITATION EVENT THOUGH
AS TEMPERATURES TOP OFF IN THE UPPER 30S/LOW 40S ON TUESDAY
AFTERNOON. AS COOLER AIR MOVES IN ON TUESDAY NIGHT...THE NORTHERN
HALF OF CENTRAL INDIANA WILL SEE A TURN OVER TO SNOW...WHILE
SOUTHERN PORTIONS CAN EXPECT A RAIN/SNOW MIX. DURING THE DAY ON
TUESDAY...NORTHERN PORTIONS WILL SEE A RAIN/SNOW MIX...WHILE THE
SOUTHERN COUNTIES WILL RECEIVE MAINLY RAIN.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 250 PM EST SUN FEB 14 2016
THE SECOND HALF OF THIS WEEK WILL BE MUCH WARMER AS AN UPPER RIDGE
OVER THE WESTERN U.S. BUILDS EASTWARD. MODELS INDICATE HIGH
PRESSURE WILL BE ACROSS OUR REGION WEDNESDAY EVENING AND THIS WILL
MOVE ON TO THE EAST COAST BY FRIDAY AS STRONG LOW PRESSURE MOVES
INTO THE UPPER MIDWEST BY FRIDAY. A STRONG SOUTHERLY FLOW WILL
DEVELOP AHEAD OF THIS LOW AND PRODUCING WIND GUSTS UP TO 30 MPH FRIDAY.
FRIDAY WILL ALSO BE QUITE WARM WITH HIGHS FROM THE MIDDLE 50S TO LOWER 60S.
MODELS INDICATE LOW CHANCES OF A FEW SHOWERS FRIDAY AND FRIDAY EVENING AS
A COLD FRONT MOVES INTO OUR REGION FRIDAY NIGHT. SATURDAY WILL BE DRY AND
A FEW DEGREES COOLER. LOW PRESSURE MOVING INTO THE MISSISSIPPI VALLEY WILL
BRING LOW CHANCES OF RAIN AGAIN BY SUNDAY. STAYED CLOSE TO MODEL
INITIALIZATION TEMPERATURES IN MOST CASES.
&&
.AVIATION /DISCUSSION FOR 141800Z TAF ISSUANCE/...
ISSUED AT 1200 PM EST SUN FEB 14 2016
POOR FLYING CONDITIONS WILL OCCUR...ESPECIALLY THIS AFTERNOON
AND EARLY TONIGHT.
AREA OF SNOW OVER ILLINOIS WILL SPREAD EAST INTO INDIANA AS AN
UPPER DISTURBANCE MOVING INTO NORTHERN ILLINOIS MOVES SOUTHEAST
ACROSS OUR REGION. EXPECT LIFR CONDITIONS AT TIMES THIS AFTERNOON
AND STILL MOSTLY IFR EARLY TONIGHT AS SNOW SHOWERS GRADUALLY
DIMINISH. CONDITIONS WILL EVENTUALLY IMPROVE TO MVFR LATER
TONIGHT WITH CEILINGS 1 TO 2 THOUSAND AND VISIBILITIES GRADUALLY
IMPROVING TO 6 MILES AS SOME SUBSIDENCE DEVELOPS ALOFT.
EVEN THOUGH MODELS INDICATE SOME DRYING ALOFT BY MONDAY...A LOW
LEVEL INVERSION WILL KEEP CEILINGS MVFR THROUGH THE DAY MONDAY.
EAST TO SOUTHEAST WINDS UP TO 15 KNOTS WILL BE THE RULE EARLY ON...
BECOMING SOUTHEAST AROUND 10 KNOTS LATE TODAY AND SOUTH OR SOUTHWEST
5 TO 8 KNOTS LATE TONIGHT AND MONDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR INZ028-
029-035>037-043>047-051>056-060>065-067>072.
&&
$$
SYNOPSIS...TDUD/CP
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....JH
AVIATION...JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1200 PM EST SUN FEB 14 2016
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 1040 AM EST SUN FEB 14 2016
CENTRAL INDIANA WILL BE UNDER AN ACTIVE WEATHER PATTERN THROUGH
NEXT WEEK AS A SERIES OF DISTURBANCES MOVE THROUGH THE REGION. THE
FIRST WILL START IMPACTING THE AREA THIS MORNING...RESULTING IN 1 TO
4 INCHES OF SNOWFALL BY TONIGHT ACROSS CENTRAL INDIANA. THE SECOND
DISTURBANCE WILL PASS THROUGH ON MONDAY...BUT RAIN MIXING IN WILL
LIMIT SNOW ACCUMULATIONS. YET ANOTHER SYSTEM WILL BRING MIXED
PRECIPITATION ON TUESDAY. FURTHER OUT...A WARM UP CAN BE EXPECTED
DURING THE EXTENDED PERIOD WITH RAIN CHANCES ON FRIDAY.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1034 AM EST SUN FEB 14 2016
CURRENTLY SEEING A LULL IN ACCUMULATING SNOWFALL ACROSS CENTRAL
INDIANA. A RELATIVELY DRY COLUMN HAS KEPT MOST OF THE SNOW THAT
FELL EARLIER THIS MORNING FROM ACCUMULATING EXCEPT IN THE HEAVIEST
BAND WHERE UP TO HALF AN INCH WAS REPORTED. A COMPACT UPPER WAVE
SEEN IN SATELLITE IMAGERY OVER IOWA WILL CONTINUE TO MOVE TOWARD
THE AREA TODAY AND ISENTROPIC LIFT WILL INCREASE FROM THE
SOUTH. RADAR TRENDS AND HI RES GUIDANCE INDICATE ACCUMULATING SNOW
WILL MOVE BACK INTO WESTERN INDIANA STARTING AROUND NOON AND
OVERSPREAD THE AREA FROM THERE. THE LAST FEW RUNS OF BOTH THE RAP
AND HRRR CONTINUE TO INDICATE THE HEAVIEST SNOW WILL FALL ACROSS
THE SOUTHERN COUNTIES AND THEY SHOW A DECENT SWATH OF 2-3 INCHES
FROM AROUND I-70 SOUTH WITH 3-4 INCHES SOUTH OF A BLOOMINGTON TO
COLUMBUS LINE AND PERHAPS EVEN ISOLATED 5 INCH AMOUNTS. BASED ON
THIS HAVE UPPED SNOWFALL AMOUNTS TO 1 TO 3 INCHES IN THE
NORTHEAST...2 TO 3 CENTRAL AND 3 TO 4 SOUTH WITH ISOLATED HIGHER
AMOUNTS. RAP AND HRRR BOTH SHOW HEAVIEST SNOW STARTING AROUND 2-3
PM AND MOVING OUT OF THE AREA BY AROUND 6 PM...BUT HAVE GIVEN THIS
A BIT OF CUSHION ON EITHER SIDE IN THE TIMING IN THE WSW. MADE NO
ADJUSTMENTS TO THE AREAL EXTENT OF THE ADVISORY BUT DID BUMP UP
AMOUNTS AND ADDED TIMING OF HEAVIEST SNOW.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 334 AM EST SUN FEB 14 2016
THE MAIN FOCUS OF THE SHORT TERM PERIOD WILL BE THE REMNANTS OF
THE FIRST SYSTEM FOLLOWED BY ANOTHER DISTURBANCE ON TUESDAY.
ISENTROPIC LIFT ABRUPTLY CUTS OFF ACROSS CENTRAL INDIANA AFTER MON
03Z AS MOISTURE DECREASES. SO...RAPIDLY DECREASED POPS FROM WEST
TO EAST AFTER SUN 06Z WITH JUST A FEW ADDITIONAL TENTHS OF AN INCH
OF SNOW ACCUMULATION OVERNIGHT.
FOCUS THEN TURNS TO THE NEXT UPPER WAVE PROGGED TO MOVE THROUGH ON
MONDAY EVENING. EXPECT A LULL IN ACTIVITY ON MONDAY AFTERNOON WITH
JUST A BRIEF SPIKE IN PRECIPITATION ON MONDAY EVENING AS THAT
UPPER WAVE MOVES THROUGH...BUT MOISTURE APPEARS LIMITED. SO...WILL
ONLY GO WITH SLIGHT CHANCE POPS FOR MONDAY EVENING AND NIGHT.
FINALLY...A THIRD DISTURBANCE WILL TRACK ACROSS THE AREA ON
TUESDAY. THIS WILL BE MORE OF A MIXED PRECIPITATION EVENT THOUGH
AS TEMPERATURES TOP OFF IN THE UPPER 30S/LOW 40S ON TUESDAY
AFTERNOON. AS COOLER AIR MOVES IN ON TUESDAY NIGHT...THE NORTHERN
HALF OF CENTRAL INDIANA WILL SEE A TURN OVER TO SNOW...WHILE
SOUTHERN PORTIONS CAN EXPECT A RAIN/SNOW MIX. DURING THE DAY ON
TUESDAY...NORTHERN PORTIONS WILL SEE A RAIN/SNOW MIX...WHILE THE
SOUTHERN COUNTIES WILL RECEIVE MAINLY RAIN.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY|/...
ISSUED AT 309 AM EST SUN FEB 14 2016
PRIMARY FOCUS THROUGH THE EXTENDED PERIOD WILL BE A FEBRUARY THAW
AS THE BROAD UPPER RIDGE OVER THE WESTERN PART OF THE COUNTRY
FINALLY SHIFTS EAST. TEMPERATURES WILL SURGE TO ABOVE NORMAL
LEVELS BY FRIDAY AND CONTINUING INTO THE WEEKEND.
THE OHIO VALLEY WILL REMAIN IN A COOL CYCLONIC FLOW ALOFT ON
WEDNESDAY AS THE UPPER TROUGH SLOWLY SHIFTS AWAY TO THE EAST . NOT
OUT OF THE QUESTION TO SEE LINGERING FLURRIES OR VERY LIGHT SNOW
SHOWERS IN THIS SETUP...BUT WILL LEAVE DRY AT THIS TIME WITH
SURFACE HIGH PRESSURE ASSERTING ITS INFLUENCE BY LATE DAY.
THE HIGH WILL SHIFT ACROSS THE GREAT LAKES AND INTO NEW ENGLAND
BY EARLY FRIDAY. AT THE SAME TIME...STRONG LOW PRESSURE WILL
DEVELOP OVER THE NORTHERN PLAINS THEN MOVE EAST INTO THE GREAT
LAKES BY FRIDAY. A STRONG S/SW FLOW WILL DEVELOP BETWEEN THE HIGH
TO THE EAST AND THE LOW TO THE NORTHWEST...RESULTING IN WINDY
CONDITIONS ON FRIDAY AND MUCH WARMER TEMPERATURES AS STRONG WARM
ADVECTION DEVELOPS AHEAD OF THE ASSOCIATED COLD FRONT. SCATTERED
RAIN SHOWERS WILL ACCOMPANY THE PASSAGE OF THE COLD FRONT LATE
FRIDAY. DRY WEATHER WILL RETURN ON SATURDAY WITH HIGH PRESSURE
BEFORE ANOTHER SYSTEM BRINGS PRECIP FOR LATE WEEKEND.
HIGHS WILL RISE INTO THE 50S TO NEAR 60 BY FRIDAY...REMAINING
ABOVE NORMAL IN THE UPPER 40S TO MID 50S OVER THE WEEKEND.
&&
.AVIATION /DISCUSSION FOR 141800Z TAF ISSUANCE/...
ISSUED AT 1200 PM EST SUN FEB 14 2016
POOR FLYING CONDITIONS WILL OCCUR...ESPECIALLY THIS AFTERNOON
AND EARLY TONIGHT.
AREA OF SNOW OVER ILLINOIS WILL SPREAD EAST INTO INDIANA AS AN
UPPER DISTURBANCE MOVING INTO NORTHERN ILLINOIS MOVES SOUTHEAST
ACROSS OUR REGION. EXPECT LIFR CONDITIONS AT TIMES THIS AFTERNOON
AND STILL MOSTLY IFR EARLY TONIGHT AS SNOW SHOWERS GRADUALLY
DIMINISH. CONDITIONS WILL EVENTUALLY IMPROVE TO MVFR LATER
TONIGHT WITH CEILINGS 1 TO 2 THOUSAND AND VISIBILITIES GRADUALLY
IMPROVING TO 6 MILES AS SOME SUBSIDENCE DEVELOPS ALOFT.
EVEN THOUGH MODELS INDICATE SOME DRYING ALOFT BY MONDAY...A LOW
LEVEL INVERSION WILL KEEP CEILINGS MVFR THROUGH THE DAY MONDAY.
EAST TO SOUTHEAST WINDS UP TO 15 KNOTS WILL BE THE RULE EARLY ON...
BECOMING SOUTHEAST AROUND 10 KNOTS LATE TODAY AND SOUTH OR SOUTHWEST
5 TO 8 KNOTS LATE TONIGHT AND MONDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR INZ028-
029-035>037-043>047-051>056-060>065-067>072.
&&
$$
SYNOPSIS...TDUD/CP
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....RYAN
AVIATION...JH
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1120 AM CST SUN FEB 14 2016
.UPDATE...
Issued at 511 AM CST SUN FEB 14 2016
The latest RAP and NAM isentropic progs continue to show the
better saturation and lift focusing to the east of the forecast
area. With the HRRR handling the shower activity earlier and
taking it out of the area, have reasonable confidence that precip
is pretty much over. Will be sending out an update to the forecast
to reflect this.
&&
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 324 AM CST SUN FEB 14 2016
08Z water vapor imagery shows a shortwave moving east across NEB and
SD and a weaker wave across AZ and NM. There also appears to be a
shortwave over British Columbia moving towards ID and MT. Surface
observations show a general trough of low pressure across the Great
Plains from west TX to the Canadian boarder as the arctic high
pressure system continues to move east. Locally, surface winds have
generally remained from the east with shallow dry air remaining over
the forecast area noted by the dewpoints still in the single digits.
For today, models show the best forcing and isentropic upglide
occurring now with the shortwave just north of the forecast area.
Once it passes to the east, the warm air advection pattern becomes
focused to the east of the forecast area and should bring an end to
precip chances for the rest of the day. Radar is starting to show
some shower activity developing over eastern KS similar to the HRRR.
RAP forecast soundings hint at some weak elevated instability but
the low level moisture has been slow to move into east central KS.
Will increase chances for precip and mention freezing rain in the
forecast. This activity should be short lived and be moving east of
the area by 8am. Think there should be some sunshine by the
afternoon behind the shortwave. So with some insolation and warm air
moving in from the west, high are forecast to be around 50 to the
mid 50s.
Tonight models show another low amplitude wave moving across the
forecast area with the GFS most aggressive in generating a couple
hundredths of precip. Model progs of forcing are rather disorganized
and continue to show deep layer moisture lacking. Because of this
think any precip is likely to remain a trace event. Precip type is
somewhat uncertain in that both the GFS and NAM forecast soundings
show a decent warm nose of +3 to +5 C. So snow is unlikely, and with
the dry air in place within low levels of the atmosphere and a
westerly wind this afternoon and evening unlikely to advect low
level moisture into the area, drizzle does not look much more
likely. The GFS would suggest temps are warm enough for any precip
to be liquid. Meanwhile the NAM has surface temps around freezing
but a lot more dry air to overcome. Think the NAM is probably
handling the thermal profile within the boundary layer better than
the GFS so have lows in the lower 30s for tonight. As for precip
type, will stick with sprinkles which possible could freeze on
elevated surfaces if there is not to much low level dry air.
.LONG TERM...(Monday through Saturday)
Issued at 324 AM CST SUN FEB 14 2016
Another shortwave in the northwest flow aloft is forecasted to track
over the area Monday morning, but should be mostly dry. The next in
the parade of shortwaves will pass over the area Tuesday morning,
and like the previous waves will lack any appreciable low level
moisture. Also, the better mid level moisture will be centered over
IA. There is a chance there may be enough precipitation falling into
this dry layer for rain to reach the surface. The better chances for
this light rain will be mainly over far northeast KS, and amounts
look to be rather minor. Luckily there is a deep enough layer of
above freezing temperatures even after saturation therefore frozen
precipitation should not be an issue. Beyond that an upper ridge
will build eastward over the central US causing temperatures to warm
well above normal. By Thursday the guidance shows highs around 70,
but given the models tendencies to underestimate these situations
have increased the highs by a few degrees. There will be some
concern for elevated fire danger on Thursday and Friday given the
warm temperatures and gusty winds.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1120 AM CST SUN FEB 14 2016
VFR conditions are expected through the period. Mid-level clouds
will move through the area overnight before skies begin to clear
tomorrow morning.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Wolters
LONG TERM...Sanders
AVIATION...Heller
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1115 AM CST SUN FEB 14 2016
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 912 AM CST SUN FEB 14 2016
WV imagery indicates a weak upper level shortwave trough sliding
southeast across the Central Plains. Meanwhile, a secondary upper
level shortwave is moving southeast out of the Northern Rockies
of western Montana. Near the surface, a weak area of high pressure
is moving slowly southeast across eastern Colorado.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 222 AM CST SUN FEB 14 2016
Cold front moving through the area early this morning bumping winds
briefly behind the boundary to gusts in the 20 knots range
locally. The larger observation picture and local GFS MOS
guidance suggests winds will quickly become lighter and westerly
this morning. Stratus will be mainly confined to the extreme
south central counties and based on the HRRR is likely to exit by
11 or 12 UTC. The consensus of most of the models data for this
afternoon points toward highs in the mid to upper 50s; perhaps
pushing 60 degrees along the Oklahoma line. However the model
variance is quite low lending to better confidence. Light winds
and cloudy skies are likely tonight as a secondary shortwave seen
for several runs now, rotates through the region. The GFS is the
only model producing any measurable QPF while others strongly
suggestive of a completely dry passage. The models are a few
degrees warmer than most MOS solutions.
.LONG TERM...(Monday THROUGH Saturday)
ISSUED AT 222 AM CST SUN FEB 14 2016
The remainder of the week is a story of a strong warming trend,
incrementally each day, to highs likely in the upper 70s and low
80s by Thursday. With such warm temperatures by Thursday,
critical fire weather may become a concern if gusts are
sufficient in the afternoon.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Monday AFTERNOON)
ISSUED AT 1113 AM CST SUN FEB 14 2016
VFR conditions will prevail at all TAF sites through early
Monday morning. Light and variable winds will persist across
southwest and central Kansas through tonight as surface high
pressure moves southeast across the Western High Plains into
western Oklahoma.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 56 32 61 37 / 10 10 0 0
GCK 57 31 63 35 / 10 10 0 0
EHA 59 33 65 37 / 0 10 0 0
LBL 58 32 65 35 / 0 10 0 0
HYS 54 32 57 36 / 10 10 0 0
P28 59 34 64 38 / 10 10 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
420 PM EST SUN FEB 14 2016
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 419 PM EST SUN FEB 14 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW DEAMPLIFYING FLOW ACROSS N
AMERICA. DEEP TROF THAT WAS OVER SE CANADA/NE CONUS 24HRS AGO IS
LIFTING NE...LEAVING BEHIND A BROAD TROF OVER THE CNTRL AND ERN
CONUS DOWNSTREAM OF A BROAD RIDGE CENTERED JUST OFF THE W COAST. A
VIGOROUS LOOKING SHORTWAVE IS TRACKING ACROSS NRN IL. ASSOCIATED
SHIELD OF SNOW HAS PASSED S OF THE AREA TODAY. UPSTREAM...SHORTWAVE
TROF OVER MANITOBA/WRN MN WILL BE THE NEXT FEATURE OF INTEREST
DURING THE SHORT TERM. MEANWHILE...INCREASING SOUTHERLY FLOW ON THE
BACKSIDE OF HIGH PRES NOW OVER THE LOWER LAKES/MID ATLANTIC STATES
IS BRINGING LES NORTHWARD OFF LAKE MI UNDER 850MB TEMPS AROUND -16C
ACROSS THE N HALF OF THE LAKE PER LATEST RAP ANALYSIS. SATELLITE AND
RADAR IMAGERY INDICATE LES HAS NOT BEEN WELL ORGANIZED AS IT LIFTED
N INTO THE SE FCST AREA THIS AFTN. THE HEAVIER SNOW HAS IMPACTED
MENOMINEE COUNTY...BUT WEB CAMS SUGGEST SNOW ACCUMULATIONS HAVE BEEN
UNDER 1 INCH.
AFOREMENTIONED SHORTWAVE TROF ACROSS WRN MN WILL SHIFT E...REACHING
CNTRL LAKE SUPERIOR/CNTRL UPPER MI AROUND 12Z MON. MODELS ARE IN
GOOD AGREEMENT SHOWING A PERIOD OF DEEP LAYER FORCING PER QVECTORS
AND A CORRESPONDING INCREASE IN DEEPER MOISTURE AHEAD OF FEATURE.
THIS SHOULD YIELD AT LEAST SOME AREAS OF -SN MOVING ACROSS THE FCST
AREA TONIGHT. OF MORE INTEREST IS WHAT HAPPENS DOWNWIND OF LAKE MI.
WITH 850MB TEMPS OF -13/-14C ACROSS NRN LAKE MI...SYNOPTIC
FORCING/DEEPER MOSITURE WILL LEAD TO A PERIOD OF LAKE ENHANCEMENT.
IN ADDITION...AS WEAK SFC TROF ASSOCIATED WITH SHORTWAVE MOVES
ACROSS THE AREA...THE CONVERGENCE ALONG THE TROF SHARPENS UP AS IT
REACHES LAKE MI...LEADING TO A FOCUSING OF THE LAKE ENHANCED SNOW.
FCST SOUNDINGS SHOW THE DGZ ENCOMPASSING A VERY DEEP LAYER 9-10FT
THICK. WHILE MODELS DON`T SHOW MUCH UPWARD MOTION IN THAT LAYER DUE
TO THE OVERALL WEAK SYNOPTIC FORCING...IT WILL STILL HELP FLUFF UP
SNOW ACCUMULATIONS. SFC TROF STEADILY CROSSES NRN LAKE MI/SE FCST
AREA ROUGHLY DURING THE 09Z-21Z TIME FRAME. STEADY PROGRESSION WILL
LIMIT SNOW ACCUMULATIONS...BUT POTENTIAL IS THERE FOR SEVERAL INCHES
OF SNOW. FOR NOW...FCST WILL SHOW TOTAL SNOW ACCUMULATION
TONIGHT/MON OF 2-3 INCHES WITH LOCAL 4 INCH AMOUNTS FROM MENOMINEE
COUNTY INTO LUCE COUNTY...SUB ADVY AMOUNTS. HOWEVER...WILL NEED TO
MONITOR THE INCREASE IN ENHANCEMENT ALONG/JUST AHEAD OF THE SFC
TROF. SINCE MUCH OF THE SNOW ACCUMULATION WILL OCCUR WITH THIS
FEATURE AND OVER A RELATIVELY SHORT PERIOD OF TIME...THE HIGHER
SNOWFALL RATES MAY REQUIRE ISSUANCE OF AN ADVY LATER. ELSEWHERE...
SNOW ACCMULATIONS SHOULD BE UNDER 1 INCH. WITH PASSAGE OF SFC
TROF...-SN WILL END.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 252 PM EST SUN FEB 14 2016
FIRST CHANCE OF ANY SORT OF SIGNIFICANT PRECIP IN THE LONG TERM IS
TUE AS A SHORTWAVE MOVES THROUGH AND TURNS LOW LEVEL WINDS NWLY
LATER IN THE DAY. 850MB TEMPS DROP TO -15C BY 00Z WED BEHIND THE
SHORTWAVE AND MAY DROP A DEGREE OR TWO MORE THROUGH WED MORNING AS
WINDS TURN NNW. A SFC RIDGE WILL MOVE IN QUICKLY BEHIND THE
SHORTWAVE...BUT MODELS DISAGREE ON HOW FAST. THE 00Z/14 ECMWF HAS
THE RIDGE OVER WRN LAKE SUPERIOR BY 18Z AND ERN LAKE SUPERIOR BY 00Z
THU...THE 12Z/14 GFS IS ABOUT 6 HOURS SLOWER...OTHER MODELS ARE IN
BETWEEN THESE SOLUTIONS. THIS WILL HELP LIMIT ACCUMULATIONS...BUT
BEFORE THE LES CUTS OFF WE COULD SEE GENERALLY 3-5 INCHES IN THE NW-
NNW WIND SNOWBELTS LATE TUE THROUGH WED (MAINLY THROUGH WED
MORNING).
ATTENTION THEN TURNS TO LATE IN THE WEEK AS MODELS CONTINUE TO SHOW
A STRONG DISTURBANCE MOVING THROUGH...ALTHOUGH MODELS STRUGGLE WITH
RUN TO RUN CONTINUITY AND AGREEMENT WITH THE COMPLEX SYSTEM. GENERAL
IDEA IS THAT STRONG WAA WILL BEGIN LATE WED NIGHT INTO THU AND
CONTINUE UNTIL A SFC LOW AND UPPER SHORTWAVE MOVES THROUGH OR NEARBY
LATE FRI INTO FRI NIGHT. AGREE WITH PREVIOUS SHIFT THAT WE COULD SEE
A SHORT PERIOD OF SNOW IN THE WAA REGIME BEFORE TEMPS WARM ENOUGH TO
SUPPORT ALL LIQUID PRECIP. AFTER THE CHANGE OVER TO LIQUID...COULD
SEE A SHORT PERIOD OF FREEZING RAIN (POSSIBLY NON-CONVECTIONAL
FREEZING RAIN WHERE SFC AIR IS ABOVE FREEZING BUT ROADS ARE BELOW
FREEZING)...BUT THE STRENGTH OF THE SLY FLOW AND WAA SHOULD END THE
FREEZING ASPECT OF THE RAIN FAIRLY QUICKLY. GFS SHOWS 0.25-0.5
INCHES OF LIQUID QPF ON FRI...THE ECMWF HAS 0.3-1.0 INCHES...THE GEM
HAS SIMILAR AMOUNTS TO THE GFS...BUT DISPLACED SE. COLD AIR SURGES
INTO THE ARE BEHIND THE SYSTEM FRI NIGHT...BUT IT DOES NOT LOOK LIKE
THERE IS MUCH FORCING FOR PRECIP AT THAT POINT...SO SNOWFALL
POTENTIAL ON THE BACK SIDE LOOKS LIMITED...NOT EVEN COLD ENOUGH FOR
SIGNIFICANT LAKE EFFECT.
VERY LIMITED CONFIDENCE FOR THE WEEKEND...BUT IN GENERAL IT DOES
LOOK LIKE COLDER AIR MOVES IN INTO THE MIDDLE OF NEXT WEEK WITH
POTENTIAL FOR SOME DISTURBANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1246 PM EST SUN FEB 14 2016
VFR CONDITIONS SHOULD CONTINUE THIS AFTN AT KIWD/KCMX/KSAW...THOUGH
STRATOCU AHEAD OF A DISTURBANCE WILL SPREAD E TO KIWD...AND STRATOCU
WILL ALSO LIFT N OFF LAKE MI TO KSAW. ATTM...IT IS EXPECTED THAT THE
CIGS ASSOCIATED WITH THE STRATOCU WILL BE ABOVE 3500FT. AS
DISTURBANCE MOVES CLOSER...EXPECT CONDITIONS TO FALL TO MVFR AT ALL
TERMINALS TONIGHT. WHILE SOME -SN WILL MOVE ACROSS THE AREA...THE
BEST CHC OF -SN AND PERHAPS A PERIOD OF IFR VIS WILL BE AT KSAW...
WHICH WILL BE MORE INFLUENCED BY MOISTURE ADVECTING N OFF LAKE MI.
WITH A DOWNSLOPE S WIND AND ABSENCE OF LAKE MI INFLUENCE...KIWD IS
LEAST LIKELY TO SEE ANY -SN. MVFR CONDITIONS WILL CONTINUE MON
MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST SUN FEB 14 2016
TIGHTENING PRES GRADIENT BETWEEN HIGH PRES NEAR THE E COAST AND A
LOW PRES TROF APPROACHING FROM THE W WILL RESULT IN SOUTHERLY WINDS
OF 20-30KT TONIGHT. THE STRONGEST WINDS WILL OCCUR OVER THE E HALF
OF THE LAKE WHERE THERE MAY BE A FEW GALE FORCE GUSTS TO 35KT. WINDS
WILL DIMINISH MON AS PRES GRADIENT WEAKENS. AFTER A PERIOD OF
RELATIVELY LIGHT WINDS UNDER 20KT MON NIGHT/TUE MORNING...PASSAGE OF
A COLD FRONT TUE WILL BRING A PERIOD OF STRONGER NORTHERLY WINDS OF
20-30KT. THERE MAY BE A PERIOD OF GALES OVER THE CNTRL PORTION OF
THE LAKE TUE NIGHT IN ADDITION TO HEAVY FREEZING SPRAY. WINDS WILL
THEN DIMINISH TO UNDER 20KT WED WITH ARRIVAL OF ANOTHER HIGH PRES
RIDGE. STRONGER SSE WIND UP TO 30 KTS WILL ARRIVE ON THU UNDER A
TIGHTENING PRES GRADIENT BETWEEN THIS HIGH SHIFTING TO THE E AND
ANOTHER APPROACHING LOW PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
254 PM EST SUN FEB 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM EST SUN FEB 14 2016
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF OVER
SE CANADA SLOWLY WEAKENING AND ALLOWING A SHRTWV RDG AXIS WITH 12HR
H5 HGT RISES UP TO 100M TO BRING LARGER SCALE SUBSIDENCE TO THE CWA.
SOME LK CLDS/LIGHT LES IS STILL LINGERING OVER THE TIP OF THE
KEWEENAW AND IN THE SN BELTS E OF MUNISING UNDER AREA OF H85 TEMPS
AOB -20C/LLVL NW FLOW...BUT SUBSIDENCE HAS HAD A SGNFT IMPACT ON
LIMITING THE INTENSITY OF THIS PCPN. ELSEWHERE SKIES HAVE CLEARED.
UNDER THE MOCLR SKIES ACRS THE W AND CENTRAL/PWAT NEAR 0.05 INCH OR
30 PCT OF NORMAL/LGT WINDS ASSOCIATED WITH SFC HI PRES PASSING THRU
WI...TEMPS AT SOME OF THE INTERIOR COLD SPOTS IN THAT AREA HAVE
FALLEN WELL BLO -20F. LOOKING TO THE W...THERE ARE TWO SHRTWVS OF
INTEREST. THE STRONGEST IS SLIDING ESEWD THRU THE DAKOTAS...WHILE
THE OTHER DISTURBANCE IS MOVING E INTO FAR SRN MANITOBA. DESPITE
VERY DRY LLVL AIR DEPICTED ON THE 00Z MPX RAOB... SOME LO/MID CLDS
AHEAD OF THESE SHRTWVS ARE PUSHING E THRU MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON CLD/POP TRENDS THIS
AFTN/TNGT ASSOCIATED WITH DISTURBANCES TO THE W AND INCRSG SLY FLOW/
WAA UNDER TIGHTENING PRES GRADIENT AS THE WI HI PRES SHIFTS TO THE
E. BIGGEST CONCERN IS POTENTIAL FOR SOME LES OFF LK MI WITH THE
INCRSG S WIND.
TODAY...STRONGER SRN MOST SHRTWV TO THE W IS FCST TO SLIDE TOWARD
THE LOWER LKS. SINCE ACCOMPANYING DPVA/DEEP LYR QVECTOR CNVGC IS
PROGGED TO STAY TO THE S OF UPR MI...MODELS SHOW VERY DRY MID LVL
AIR LINGERING OVER UPR MI. SOME MID LVL MSTR IS FCST TO MOVE INTO
THE WRN CWA LATER TODAY AHEAD OF THE WEAKER NRN DISTURBANCE...WHICH
IS FCST TO REACH NEAR INL BY 00Z MON. BUT DOWNSLOPE NATURE OF INCRSG
S WIND UNDER TIGHTENING PRES GRADIENT BTWN HI PRES SHIFTING TOWARD
THE MID ATLANTIC AND FALLING MSLP IN MN SHOULD KEEP THE W PCPN FREE
DESPITE THE INCRSG MID CLDS. THE SHORTER TIME GUIDANCE IS IN GOOD
AGREEMENT ON GENERATING SOME LGT LES OFF LK MI BY 18Z WITH SSE SFC-
H925 FLOW FLOWING UP THE LONG AXIS OF LK MI. WHILE THE ORIENTATION
OF THE FLOW UP LK MI AND H85 TEMPS REBOUNDING ONLY TO ARND -15C ARE
FAVORABLE...THE DRYNESS OF THE AIRMASS IN PLACE PER THE 00Z GRB RAOB
AS WELL ACYC NATURE OF THE H925 FLOW/LO INVRN BASE NEAR 4K FT AGL
AWAY FM DYNAMIC FORCING ASSOCIATED WITH TWO SHRTWVS TO THE W SHOULD
LIMIT COVERAGE OF SN SHOWERS/POPS AND ESPECIALLY SN TOTALS. WHILE A
FEW PLACES COULD PICK UP AN INCH OF SN...MOST LOCATIONS SHOULD SEE
LESS. INCRSG SUN ANGLE/A GOOD DEAL OF SUNSHINE AWAY FM THE LK CLDS
STREAMING OFF LK MI AND AHEAD OF DEEPER MID LVL MSTR MOVING IN FM
THE W SHOULD ALLOW VERY LO TEMPS THIS MRNG TO RECOVER CLOSER TO
NORMAL THIS AFTN.
TNGT...ARRIVAL OF SOME DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF NRN
SHRTWV TNGT IN THE PRESENCE OF PERSISTENT SLY FLOW UP THE LONG AXIS
OF LK MI AND H85 TEMPS FCST TO REMAIN AS LO AS ABOUT -13C OVER NRN
LK MI THRU 12Z MON WL ALLOW FOR SOME LK ENHANCEMENT OF THE LES IN
THE 06Z-12Z TIME TNGT. MODELS SHOW SOME SHARPER LLVL CNVGC IMPACTING
PORTIONS OF THE SE CWA AS FAR E AS THE GARDEN PENINSULA BY 12Z.
CONSIDERING THE FAVORABLE DEPTH OF THE DGZ AFTER THE ARRIVAL OF THE
DEEPER MSTR...SUSPECT SN FALL RATES COULD REACH 1-2 INCHES PER HR
UNDER THIS AXIS OF CNVGC. ALTHOUGH A GOOD NUMBER OF THE HI RES
MODELS INDICATE THIS AXIS OF LLVL CNVGC WL BE RATHER TRANSIENT...
SOME DO SHOW A SLOWER DRIFT THAT COULD RESULT IN SOME ADVY SN
TOTALS. AWAY FM THE LK MI ENHANCEMENT...ANY SN WL BE LGT...
ESPECIALLY IN AREAS OVER THE W/NW NEAR LK SUP WHERE THE S WIND WL
DOWNSLOPE. LO TEMPS TNGT WL BE MUCH WARMER THAN THIS MRNG WITH
INCRSG MSTR/STEADY SSW FLOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 252 PM EST SUN FEB 14 2016
FIRST CHANCE OF ANY SORT OF SIGNIFICANT PRECIP IN THE LONG TERM IS
TUE AS A SHORTWAVE MOVES THROUGH AND TURNS LOW LEVEL WINDS NWLY
LATER IN THE DAY. 850MB TEMPS DROP TO -15C BY 00Z WED BEHIND THE
SHORTWAVE AND MAY DROP A DEGREE OR TWO MORE THROUGH WED MORNING AS
WINDS TURN NNW. A SFC RIDGE WILL MOVE IN QUICKLY BEHIND THE
SHORTWAVE...BUT MODELS DISAGREE ON HOW FAST. THE 00Z/14 ECMWF HAS
THE RIDGE OVER WRN LAKE SUPERIOR BY 18Z AND ERN LAKE SUPERIOR BY 00Z
THU...THE 12Z/14 GFS IS ABOUT 6 HOURS SLOWER...OTHER MODELS ARE IN
BETWEEN THESE SOLUTIONS. THIS WILL HELP LIMIT ACCUMULATIONS...BUT
BEFORE THE LES CUTS OFF WE COULD SEE GENERALLY 3-5 INCHES IN THE NW-
NNW WIND SNOWBELTS LATE TUE THROUGH WED (MAINLY THROUGH WED
MORNING).
ATTENTION THEN TURNS TO LATE IN THE WEEK AS MODELS CONTINUE TO SHOW
A STRONG DISTURBANCE MOVING THROUGH...ALTHOUGH MODELS STRUGGLE WITH
RUN TO RUN CONTINUITY AND AGREEMENT WITH THE COMPLEX SYSTEM. GENERAL
IDEA IS THAT STRONG WAA WILL BEGIN LATE WED NIGHT INTO THU AND
CONTINUE UNTIL A SFC LOW AND UPPER SHORTWAVE MOVES THROUGH OR NEARBY
LATE FRI INTO FRI NIGHT. AGREE WITH PREVIOUS SHIFT THAT WE COULD SEE
A SHORT PERIOD OF SNOW IN THE WAA REGIME BEFORE TEMPS WARM ENOUGH TO
SUPPORT ALL LIQUID PRECIP. AFTER THE CHANGE OVER TO LIQUID...COULD
SEE A SHORT PERIOD OF FREEZING RAIN (POSSIBLY NON-CONVECTIONAL
FREEZING RAIN WHERE SFC AIR IS ABOVE FREEZING BUT ROADS ARE BELOW
FREEZING)...BUT THE STRENGTH OF THE SLY FLOW AND WAA SHOULD END THE
FREEZING ASPECT OF THE RAIN FAIRLY QUICKLY. GFS SHOWS 0.25-0.5
INCHES OF LIQUID QPF ON FRI...THE ECMWF HAS 0.3-1.0 INCHES...THE GEM
HAS SIMILAR AMOUNTS TO THE GFS...BUT DISPLACED SE. COLD AIR SURGES
INTO THE ARE BEHIND THE SYSTEM FRI NIGHT...BUT IT DOES NOT LOOK LIKE
THERE IS MUCH FORCING FOR PRECIP AT THAT POINT...SO SNOWFALL
POTENTIAL ON THE BACK SIDE LOOKS LIMITED...NOT EVEN COLD ENOUGH FOR
SIGNIFICANT LAKE EFFECT.
VERY LIMITED CONFIDENCE FOR THE WEEKEND...BUT IN GENERAL IT DOES
LOOK LIKE COLDER AIR MOVES IN INTO THE MIDDLE OF NEXT WEEK WITH
POTENTIAL FOR SOME DISTURBANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1246 PM EST SUN FEB 14 2016
VFR CONDITIONS SHOULD CONTINUE THIS AFTN AT KIWD/KCMX/KSAW...THOUGH
STRATOCU AHEAD OF A DISTURBANCE WILL SPREAD E TO KIWD...AND STRATOCU
WILL ALSO LIFT N OFF LAKE MI TO KSAW. ATTM...IT IS EXPECTED THAT THE
CIGS ASSOCIATED WITH THE STRATOCU WILL BE ABOVE 3500FT. AS
DISTURBANCE MOVES CLOSER...EXPECT CONDITIONS TO FALL TO MVFR AT ALL
TERMINALS TONIGHT. WHILE SOME -SN WILL MOVE ACROSS THE AREA...THE
BEST CHC OF -SN AND PERHAPS A PERIOD OF IFR VIS WILL BE AT KSAW...
WHICH WILL BE MORE INFLUENCED BY MOISTURE ADVECTING N OFF LAKE MI.
WITH A DOWNSLOPE S WIND AND ABSENCE OF LAKE MI INFLUENCE...KIWD IS
LEAST LIKELY TO SEE ANY -SN. MVFR CONDITIONS WILL CONTINUE MON
MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 AM EST SUN FEB 14 2016
AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES DEPARTING TO THE E AND
A LO PRES TROF APPROACHING FROM THE W...EXPECT LIGHT WINDS TODAY
OVER THE LAKE TO INCREASE TO S WINDS UP TO 30 KTS TONIGHT. THE
HIGHEST WINDS WILL OCCUR NEAR THE CANADIAN BORDER OVER THE E
HALF...WHERE A FEW GALE FORCE GUSTS TO 35 KTS ARE POSSIBLE. THESE
WINDS WILL DIMINISH ON MON UNDER A WEAKENING GRADIENT. AFTER A
PERIOD OF RELATIVELY LIGHT WINDS LATER ON MON AND MON
NIGHT...ANOTHER ROUND OF STRONG NNW WINDS THAT WILL AT LEAST
APPROACH 35 KT GALES FOR A SHORT TIME WILL DEVELOP TUE NIGHT
FOLLOWING A COLD FRONTAL PASSAGE. BEST CHANCE FOR THESE GALES TO 35
KTS WILL BE OVER THE NCENTRAL AND E HALF. WINDS WILL THEN DIMINISH
WED WITH ARRIVAL OF ANOTHER HIGH PRES RIDGE. BUT STRONGER SSE WIND
UP TO 30 KTS WILL ARRIVE ON THU UNDER A TIGHTENING PRES GRADIENT
BETWEEN THIS HI SHIFTING TO THE E AND ANOTHER APPROACHING LO PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1247 PM EST SUN FEB 14 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM EST SUN FEB 14 2016
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF OVER
SE CANADA SLOWLY WEAKENING AND ALLOWING A SHRTWV RDG AXIS WITH 12HR
H5 HGT RISES UP TO 100M TO BRING LARGER SCALE SUBSIDENCE TO THE CWA.
SOME LK CLDS/LIGHT LES IS STILL LINGERING OVER THE TIP OF THE
KEWEENAW AND IN THE SN BELTS E OF MUNISING UNDER AREA OF H85 TEMPS
AOB -20C/LLVL NW FLOW...BUT SUBSIDENCE HAS HAD A SGNFT IMPACT ON
LIMITING THE INTENSITY OF THIS PCPN. ELSEWHERE SKIES HAVE CLEARED.
UNDER THE MOCLR SKIES ACRS THE W AND CENTRAL/PWAT NEAR 0.05 INCH OR
30 PCT OF NORMAL/LGT WINDS ASSOCIATED WITH SFC HI PRES PASSING THRU
WI...TEMPS AT SOME OF THE INTERIOR COLD SPOTS IN THAT AREA HAVE
FALLEN WELL BLO -20F. LOOKING TO THE W...THERE ARE TWO SHRTWVS OF
INTEREST. THE STRONGEST IS SLIDING ESEWD THRU THE DAKOTAS...WHILE
THE OTHER DISTURBANCE IS MOVING E INTO FAR SRN MANITOBA. DESPITE
VERY DRY LLVL AIR DEPICTED ON THE 00Z MPX RAOB... SOME LO/MID CLDS
AHEAD OF THESE SHRTWVS ARE PUSHING E THRU MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON CLD/POP TRENDS THIS
AFTN/TNGT ASSOCIATED WITH DISTURBANCES TO THE W AND INCRSG SLY FLOW/
WAA UNDER TIGHTENING PRES GRADIENT AS THE WI HI PRES SHIFTS TO THE
E. BIGGEST CONCERN IS POTENTIAL FOR SOME LES OFF LK MI WITH THE
INCRSG S WIND.
TODAY...STRONGER SRN MOST SHRTWV TO THE W IS FCST TO SLIDE TOWARD
THE LOWER LKS. SINCE ACCOMPANYING DPVA/DEEP LYR QVECTOR CNVGC IS
PROGGED TO STAY TO THE S OF UPR MI...MODELS SHOW VERY DRY MID LVL
AIR LINGERING OVER UPR MI. SOME MID LVL MSTR IS FCST TO MOVE INTO
THE WRN CWA LATER TODAY AHEAD OF THE WEAKER NRN DISTURBANCE...WHICH
IS FCST TO REACH NEAR INL BY 00Z MON. BUT DOWNSLOPE NATURE OF INCRSG
S WIND UNDER TIGHTENING PRES GRADIENT BTWN HI PRES SHIFTING TOWARD
THE MID ATLANTIC AND FALLING MSLP IN MN SHOULD KEEP THE W PCPN FREE
DESPITE THE INCRSG MID CLDS. THE SHORTER TIME GUIDANCE IS IN GOOD
AGREEMENT ON GENERATING SOME LGT LES OFF LK MI BY 18Z WITH SSE SFC-
H925 FLOW FLOWING UP THE LONG AXIS OF LK MI. WHILE THE ORIENTATION
OF THE FLOW UP LK MI AND H85 TEMPS REBOUNDING ONLY TO ARND -15C ARE
FAVORABLE...THE DRYNESS OF THE AIRMASS IN PLACE PER THE 00Z GRB RAOB
AS WELL ACYC NATURE OF THE H925 FLOW/LO INVRN BASE NEAR 4K FT AGL
AWAY FM DYNAMIC FORCING ASSOCIATED WITH TWO SHRTWVS TO THE W SHOULD
LIMIT COVERAGE OF SN SHOWERS/POPS AND ESPECIALLY SN TOTALS. WHILE A
FEW PLACES COULD PICK UP AN INCH OF SN...MOST LOCATIONS SHOULD SEE
LESS. INCRSG SUN ANGLE/A GOOD DEAL OF SUNSHINE AWAY FM THE LK CLDS
STREAMING OFF LK MI AND AHEAD OF DEEPER MID LVL MSTR MOVING IN FM
THE W SHOULD ALLOW VERY LO TEMPS THIS MRNG TO RECOVER CLOSER TO
NORMAL THIS AFTN.
TNGT...ARRIVAL OF SOME DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF NRN
SHRTWV TNGT IN THE PRESENCE OF PERSISTENT SLY FLOW UP THE LONG AXIS
OF LK MI AND H85 TEMPS FCST TO REMAIN AS LO AS ABOUT -13C OVER NRN
LK MI THRU 12Z MON WL ALLOW FOR SOME LK ENHANCEMENT OF THE LES IN
THE 06Z-12Z TIME TNGT. MODELS SHOW SOME SHARPER LLVL CNVGC IMPACTING
PORTIONS OF THE SE CWA AS FAR E AS THE GARDEN PENINSULA BY 12Z.
CONSIDERING THE FAVORABLE DEPTH OF THE DGZ AFTER THE ARRIVAL OF THE
DEEPER MSTR...SUSPECT SN FALL RATES COULD REACH 1-2 INCHES PER HR
UNDER THIS AXIS OF CNVGC. ALTHOUGH A GOOD NUMBER OF THE HI RES
MODELS INDICATE THIS AXIS OF LLVL CNVGC WL BE RATHER TRANSIENT...
SOME DO SHOW A SLOWER DRIFT THAT COULD RESULT IN SOME ADVY SN
TOTALS. AWAY FM THE LK MI ENHANCEMENT...ANY SN WL BE LGT...
ESPECIALLY IN AREAS OVER THE W/NW NEAR LK SUP WHERE THE S WIND WL
DOWNSLOPE. LO TEMPS TNGT WL BE MUCH WARMER THAN THIS MRNG WITH
INCRSG MSTR/STEADY SSW FLOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 442 AM EST SUN FEB 14 2016
...ACTIVE PATTERN WITH WINTRY MIX POSSIBLE LATE THIS WEEK...
IN THE LARGE SCALE...ENERGETIC PACIFIC JET STREAM WILL LEAD TO
ACTIVE AMPLIFIED FLOW AND CHANGEABLE WEATHER PATTERN NEXT 7-10 DAYS
ACROSS NORTH AMERICA. MAIN CHANCE OF WIDESPREAD LGT SNOW OCCURS MON
WITH LAKE ENHANCED SNOW POSSIBLE IN AREAS DOWNWIND OF LK MICHIGAN.
BETTER CHANCES OF LAKE EFFECT OFF LK SUPERIOR OCCUR TUE AFTN THROUGH
WED AS MORE COLD AIR SWEEPS OVER GREAT LAKES. NEXT STRONGER SYSTEM
WITH WARM AIR ADVECTION ARRIVES IN SOME SHAPE OR FORM THU/FRI.
WARMING ALOFT WILL LEAD TO LIQUID PRECIP AT SOME POINT THU NIGHT INTO
FRI...BUT THAT MAY BE PRECEEDED BY WIDESPREAD LIGHT TO MODERATE SNOW.
EXTENT OF PRECIP WITH THE SYSTEM IS UNKNOWN THOUGH AS MODELS DIFFER
ON WHERE STRONGEST SFC LOW AND LIFT FOR PRECIP DEVELOPS. PLENTY OF
TIME TO SORT OUT THESE DETAILS. NO MATTER HOW YOU LOOK AT IT APPEARS
A MESSY MIX OF WINTRY WEATHER WOULD OCCUR THU NIGHT INTO FRI.
ON MON...DEEP TROUGHING ALOFT FM THIS WEEKEND WILL BE GONE...BUT
SHORTWAVE TROUGH WILL BE ON ITS WAY TO RE-SHARPENING TROUGHING INTO
TUE. SHORTWAVE AND SFC LOW ON LEADING EDGE OF TROUGHING WILL HELP IN
SPREADING WIDESPREAD LGT SNOW ACROSS CWA. CONVERGENT SRLY FLOW OFF
LK MICHIGAN AND SUFFICIENT OVER-WATER INSTABILITY WITH H85 TEMPS
AROUND -13C OPENS DOOR FOR LAKE ENHANCEMENT MON MORNING INTO EARLY
MON AFTN. MAJORITY OF HIGH RES QPF INDICATES NARROW BAND/S OF LAKE
EFFECT WITH POSSIBILITY OF SNOW RATES OVER 1 INCH PER HOUR HELPED
OUT BY DEEP DGZ OVER 10KFT. MOST GUIDANCE ALSO SHOWS SUCH BANDS
SHIFTING ALONG AND NOT STAYING PUT OVER ONE LOCATION. AREA MOST
FAVORED FOR LAKE ENHANCEMENT AND A FEW INCHES OF SNOW WOULD BE
MENOMINEE COUNTY INTO SOUTHERN DELTA AND SOUTHERN SCHOOLCRAFT
COUNTIES. STILL TOO EARLY TO DO ANY TYPE OF HEADLINE SINCE IT IS
UNDERTAIN WHERE HEAVIER LAKE ENHANCED SNOW OCCURS...BUT MAY NEED A
HEADLINE EVENTUALLY. WILL MENTION HEAVIER SNOW POSSIBILITY IN THE
HAZARDOUS WEATHER OUTLOOK.
GENERALLY QUIET MON NIGHT INTO TUE MORNING AHEAD OF STRONGER
SHORTWAVE AND SFC LOW/TROUGH DROPPING ACROSS MANTIOBA/ONTARIO.
SOUNDINGS SHOW LOW-LEVEL MOISTURE WITH TEMPS WARMER THAN -8C SO
COULD SEE FZDZ POSSIBLE...ESPECIALLY WEST CLOSER TO APPROACHING SFC
TROUGH. MAIN IMPACT OF LOW-LEVEL MOISTURE/CLOUDS WILL BE TO HELP
KEEP TEMPS IN THE MID TEENS TO LOWER 20S. A FAR CRY FM THE BITTER
COLD OCCURRING THIS MORNING. WENT TOWARD WARMER GUIDANCE ON TUE AS
IF TROUGH SLOWS SOME ON TUE...WOULD HAVE OPPORTUNITY FOR TEMPS TO
REACH LOW-MID 30S. TROUGH ARRIVES IN THE AFTN NORTHWEST THEN SWEEPS
OVER REST OF CWA BY EVENING. A BURST OF MODERATE TO HEAVY SNOW ON
TROUGH AXIS SEEMS REASONABLE. THOUGH THIS WOULD BE BRIEF...ITS
ARRIVAL MAY TIME OUT WITH AFTN/EVENING COMMUTE. WILL BE SOMETHING
TO KEEP AWARE OF. LAKE EFFECT IN THE WAKE OF THE TROUGH SHOULD BE
OKAY TO START BUT AS LARGE HIGH PRESSURE QUICKLY BUILDS IN...EXPECT
IT TO BEGIN TO STRUGGLE. SOUNDINGS SHOW QUICKLY DEVELOPING
SUBSIDENCE WITH GFS POINT AT P53 /MUNISING/ SHOWING INVERSIONS OVER
6-8KFT TUE EVENING LOWERING TO 4-5KFT BY MIDNIGHT. GOOD PART OF DGZ
IS WITHIN THE LAKE CONVECTIVE LAYER...BUT SUBSIDENCE ALOFT AND QUICK
FORMATION OF ANTICYCLONIC SFC FLOW WITH THE HIGH BUILDING IN SHOULD
LIMIT LES INTENSITY. KEPT POPS HIGH...BUT QPF/SNOW QUICKLY COMES
DOWN AFT TUE EVENING. GUSTY NW WINDS 20-30 MPH WITH THE COLD AIR
ADVECTION IN BLYR SHOULD LEAD TO BLSN/LOWER VSBY AND COULD TIP THIS
TO NEEDING AN ADVY. JURY STILL OUT ON THAT THOUGH. WILL MENTION IN
THE HAZARDOUS WEATHER OUTLOOK.
LAKE EFFECT RUNS ITS COURSE ON WED AND AS SFC RIDGE CROSSES WED AFTN
INTO WED EVENING...SHOULD SHUT DOWN ON WED EVENING WITH LOSS OF
ONSHORE FLOW. SCT MID-HIGH CLOUDS...BUT MAY BE ANOTHER CHILLY NIGHT
WITH THE RIDGE IN THE VCNTY. GIVEN THIS SETUP PROBABLY DID NOT GO
COLD ENOUGH AND LATER SHIFTS MAY NEED TO LOWER TEMPS BELOW CONSENSUS.
LOWEST GUIDANCE SHOWING MINS IN THE SINGLE NUMBERS BLO ZERO FOR THE
INTERIOR.
ATTN LATE THIS WEEK IS ON STRONG WARM AIR ADVECTION PATTERN AS SFC
RIDGE SLIDES OVER NEW ENGLAND AND STRONG SFC LOW...THANKS IN PART TO
THAT VIGOROUS PACIFIC JET STREAM MENTIONED AT THE TOP...EXPANDS OVER
FM THE CANADIAN ROCKIES TO THE NORTHERN PLAINS. COLD AIR ALOFT WILL
GIVE WAY TO H85 TEMPS ABOVE ZERO AS EARLY AS THU EVENING WITH SURGE
OF WARMER AIR /H85 TEMPS MAYBE AS WARM AS +6C/ WASHING ACROSS THE
WESTERN GREAT LAKES ON FRI. WARMING EVENTUALLY MAKES IT TO SFC WITH
HIGH TEMPS WELL INTO THE 30S IF NOT INTO LOW 40S FOR PARTS OF
WESTERN CWA. UNTIL WARMING MAKES IT TO SFC...THE WARM AIR ALOFT WILL
RESULT IN THE SNOW THAT DEVELOPS IN WARM AIR ADVECTION PATTERN THU
AFTN INTO THU NIGHT TO CHANGE TO LIQUID PRECIP FM WEST TO EAST LATE
THU NIGHT INTO FRI. PRECIP COULD BE ENHANCED DEPENDING ON STRENGTH
OF SHORTWAVE DIGGING ACROSS THE UPPER GREAT LAKES. TEMPS WILL BE ON
THE RISE BUT LINGERING COLD TEMPS NEAR SFC COULD RESULT IN FZRA AND
ICING ISSUES AT LEAST BRIEFLY FOR PARTS OF CWA. SINCE S FLOW IS
STRONG AS SEEN BY THE H85 WINDS NEAR 50 KTS INTO WI ON THU NIGHT AS
THE SFC HIGH IS MORE EAST OF HERE VERSUS NORTHEAST /LIMITING COLD
DRY EASTERLY SFC FLOW THAT WOULD TEMPER SFC WARMING/...THINK THE
WARMING AT THE SFC WILL ARRIVE PRETTY QUICKLY SO MIXED PRECIP SHOULD
CONVERT TO RAIN EVEN AT THE SFC LATER FRI MORNING INTO FRI AFTN.
WILL CONTINUE TO MENTION WINTRY MIX AND ICE POTENTIAL IN THE
HAZARDOUS WEATHER OUTLOOK.
TREND IS FOR COOLER TEMPS TO RETURN NEXT SAT ONCE THE LARGE SFC LOW
AND WARM FRONT PASS TO THE EAST. JUST A SMALL CHANCE FOR SNOW
SHOWERS AT THAT TIME. CONSENSUS GUIDANCE UTILIZED FOR TEMPS WHICH
BROUGHT TEMPS BACK INTO THE 20S TO LOWER 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1246 PM EST SUN FEB 14 2016
VFR CONDITIONS SHOULD CONTINUE THIS AFTN AT KIWD/KCMX/KSAW...THOUGH
STRATOCU AHEAD OF A DISTURBANCE WILL SPREAD E TO KIWD...AND STRATOCU
WILL ALSO LIFT N OFF LAKE MI TO KSAW. ATTM...IT IS EXPECTED THAT THE
CIGS ASSOCIATED WITH THE STRATOCU WILL BE ABOVE 3500FT. AS
DISTURBANCE MOVES CLOSER...EXPECT CONDITIONS TO FALL TO MVFR AT ALL
TERMINALS TONIGHT. WHILE SOME -SN WILL MOVE ACROSS THE AREA...THE
BEST CHC OF -SN AND PERHAPS A PERIOD OF IFR VIS WILL BE AT KSAW...
WHICH WILL BE MORE INFLUENCED BY MOISTURE ADVECTING N OFF LAKE MI.
WITH A DOWNSLOPE S WIND AND ABSENCE OF LAKE MI INFLUENCE...KIWD IS
LEAST LIKELY TO SEE ANY -SN. MVFR CONDITIONS WILL CONTINUE MON
MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 AM EST SUN FEB 14 2016
AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES DEPARTING TO THE E AND
A LO PRES TROF APPROACHING FROM THE W...EXPECT LIGHT WINDS TODAY
OVER THE LAKE TO INCREASE TO S WINDS UP TO 30 KTS TONIGHT. THE
HIGHEST WINDS WILL OCCUR NEAR THE CANADIAN BORDER OVER THE E
HALF...WHERE A FEW GALE FORCE GUSTS TO 35 KTS ARE POSSIBLE. THESE
WINDS WILL DIMINISH ON MON UNDER A WEAKENING GRADIENT. AFTER A
PERIOD OF RELATIVELY LIGHT WINDS LATER ON MON AND MON
NIGHT...ANOTHER ROUND OF STRONG NNW WINDS THAT WILL AT LEAST
APPROACH 35 KT GALES FOR A SHORT TIME WILL DEVELOP TUE NIGHT
FOLLOWING A COLD FRONTAL PASSAGE. BEST CHANCE FOR THESE GALES TO 35
KTS WILL BE OVER THE NCENTRAL AND E HALF. WINDS WILL THEN DIMINISH
WED WITH ARRIVAL OF ANOTHER HIGH PRES RIDGE. BUT STRONGER SSE WIND
UP TO 30 KTS WILL ARRIVE ON THU UNDER A TIGHTENING PRES GRADIENT
BETWEEN THIS HI SHIFTING TO THE E AND ANOTHER APPROACHING LO PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
317 PM CST SUN FEB 14 2016
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
THE MAIN FORECAST CHALLENGE THROUGH MONDAY AFTERNOON IS
PRECIPITATION. A MID LEVEL SHORTWAVE AND A SURFACE TROUGH WILL
TRAVERSE THE FORECAST AREA LATE THIS EVENING WHILE ANOTHER SYSTEM
APPROACHES NORTHWEST NEBRASKA MONDAY AFTERNOON.
THIS EVENING AND TONIGHT...THE 12Z MODEL SUITE ALONG WITH HRRR AND
RAP GENERALLY AGREE WITH PREVIOUS FORECAST PACKAGE...SO MADE MINOR
ADJUSTMENTS TO PRECIPITATION AND TEMPERATURES. WEAK RADAR ECHOES
OVER PARTS OF NORTHERN NEBRASKA AND THE PANHANDLE TODAY HAVE BEEN
THE RESULT OF MID LEVEL CLOUDS AND VIRGA...VERIFIED BY WEB CAMERAS
AND SURFACE OBS. THE GFS...ECM...AND NAM SHOW SUFFICIENT 500-700 HPA
FRONTOGENESIS ACROSS THE FORECAST AREA THIS EVENING...BUT FORECAST
SOUNDINGS INDICATE CONTINUED LOW LEVEL DRY AIR...ESPECIALLY ACROSS
SOUTHWEST NEBRASKA. THE RAP AND NAM BRING SATURATION AS LOW AS
850HPA ACROSS THE NORTH WHILE THE HRRR SHOWS SCATTERED LIGHT SHOWERS
NORTH AND FAR SOUTHWEST. DESPITE THE DRY AIR IN THE SOUTH...RAP
FORECAST SOUNDINGS SUGGEST AMPLE LOW LEVEL LIFT TO SUPPORT A LIGHT
SHOWER IF EVAPORATIVE COOLING OCCURS. KEPT SCHC MENTION GENERALLY
ACROSS THE NORTHERN THIRD OF THE FORECAST AREA AND SPRINKLES/
FLURRIES FOR THE REMAINDER. THE TEMPERATURE PROFILE GENERALLY
SUPPORTS RAIN AS 0-2KFT AGL TEMPS AND SFC WET BULB REMAIN ABOVE
FREEZING. HOWEVER...DID MENTION RASN AFTER 03Z AS SATURATION AND
LIFT OCCUR IN THE DGZ. MOST OF THE FORCING AND LOW/MID LEVEL
MOISTURE MOVE EAST AFTER 06Z WHEN ALL SNOW WOULD BE BETTER
SUPPORTED. KEPT MIN TEMPS ABOVE MOS GUIDANCE TO ACCOUNT FOR
CLOUDS...850HPA TEMPS ABOVE 0C...AND WINDS STAYING NEAR 10 KTS.
MONDAY...TRENDED MAX TEMPS UP A DEGREE OR TWO TO FOLLOW THE ECM AND
MAV MORE CLOSELY. DESPITE INCREASING CLOUD COVER THROUGH THE
DAY...WAA AT 850HPA AND DOWNSLOPING WINDS SHOULD OVERCOME. THE NEXT
WAVE OF MOISTURE ENTERS NORTHWEST NEBRASKA EARLY AFTERNOON...BUT LOW
LEVEL DRY AIR MAY HANG ON THROUGH LATE AFTERNOON OR EARLY EVENING.
ISENTROPIC LIFT IS MORE EVIDENT WITH THIS SYSTEM...ESPECIALLY ACROSS
THE NORTH. INCLUDED SCHC AS EARLY AS 18Z FAR NORTHWEST...BUT BETTER
CHANCE OCCURS AFTER 00Z AS LOW LEVEL MOISTENING AND LIFT INCREASE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
MONDAY NIGHT THROUGH WEDNESDAY...A FAIRLY POTENT UPPER LEVEL
DISTURBANCE NEAR OR JUST OVER THE COAST OF CNTL BRITISH COLUMBIA
WILL MOVE RAPIDLY THROUGH THE MISSOURI BASIN MONDAY NIGHT. THE PTYPE
IS RAIN SHOWERS AS THE FCST AREA WILL BE ON THE SRN OR WARM SIDE OF
THE DISTURBANCE. LOWS TUESDAY MORNING FALL INTO THE LOWER 30S.
COOLING ALOFT COULD PERHAPS PRODUCE A MIX BUT THE PREDOMINATE PTYPE
IS RAIN.
THE MORNING RUN OF THE ECM SHOWS SHOWERS AS FAR SOUTH AS INTERSTATE
80 WITH THIS SYSTEM. THE MODEL CONSENSUS IS ALONG OR NORTH OF
NEBRASKA HIGHWAY 2. THE ECM SHOWS MUCH MORE ROBUST 700-500MB
MOISTURE BUT VERY MODEST SATURATION IN THE 850-700MB LAYER.
THE THREE GUIDANCE DATA SETS ARE VERY CLOSE FOR HIGHS TUESDAY IN THE
LOWER 40S TO MID 50S. SOME MIDLEVEL COOLING IN THE MORNING WILL HAVE
TO BE OVERCOME. H850MB TEMPERATURES SHOULD RISE TO 0C TO 8C BY LATE
AFTERNOON. A MIX OF SUN AND CLOUDS WAS INDICATED IN THE MODELS.
THERMAL RIDGING CONTINUES TO BUILD TUESDAY NIGHT AND WEDNESDAY WITH
H850MB TEMPERATURES RISING TO 5C TO 10C. THIS SUPPORTS LOWS IN THE
UPPER 20S TO LOWER 30S AND HIGHS IN THE 50S TO NEAR 60. GENERALLY
CLEAR SKIES ARE EXPECTED DURING THIS TIME. SOME HIGH CIRRUS MAY BE
OVERHEAD IN THE AFTERNOON.
WEDNESDAY NIGHT THROUGH SUNDAY...THURSDAY IS THE BIG DAY. WEST-
SOUTHWEST WINDS ARE UNIDIRECTIONAL TO 700MB AND H850MB TEMPERATURES
RISE TO 15C TO 20C. HIGHS WILL EASILY RISE INTO THE 60S. THE GFS AND
ECM SHOW A LONG WAVE TROF FLUSHING WARM AIR ACROSS THE ROCKIES AND
INTO THE CNTL PLAINS. HIGH CLOUDINESS ASSOCIATED WITH A BAROCLINIC
LEAF POSITIONED ACROSS THE NRN PLAINS AND MIDWEST COULD PLACE THE
FCST AREA IN NEARLY FULL SUN. LATER FORECASTS MAY RAISE HIGHS A BIT.
A BLEND OF GUIDANCE PLUS BIAS CORRECTION WAS THE BASIS FOR THE
TEMPERATURE FORECAST.
A KINK SHOWED UP IN THE FORECAST THURSDAY NIGHT ASSOCIATED WITH A
PACIFIC COLD FRONT FRIDAY. 700MB WINDS INCREASE TO 60 TO 75 KTS
AHEAD OF THE FRONT IN THE ECM AND GFS. COUPLED WITH A PV1.5 ANOMALY
AND 6 HR PRESSURE RISES OF 12-16MB...A PERIOD OF STRONG OR HIGH WIND
GUSTS COULD DEVELOP THURSDAY NIGHT. LATER FORECASTS WILL MONITOR
THIS POTENTIAL WIND EVENT.
LOW PRESSURE TRACKS INTO THE UPPER MIDWEST FRIDAY AND THIS SHOULD
SEND A PACIFIC COLD FRONT THROUGH THE FCST AREA. H850MB TEMPERATURES
COOL TO 5C TO 10C SUPPORTING HIGHS IN THE 50S TO AROUND 60.
DOWNSLOPING WEST NORTHWEST WINDS NEAR 25 TO 30 MPH WILL CONTINUE TO
SUPPORT DEEP VERTICAL MIXING.
ZONAL FLOW ALOFT IS IN PLACE SATURDAY AND A NEW SFC LOW FORMS ON THE
NRN HIGH PLAINS. NO SIGNIFICANT WARMING OR COOLING IS SHOWN AT
H850MB BUT WEAK WINDS SUGGEST A SHALLOWER MIXING HEIGHT. THE
FORECAST FOR HIGHS IN THE 50S WOULD APPEAR THE BEST FIT.
SOME SORT OF COLD FRONT IS SHOWN BY THE GFS...ECM AND GFS ENSEMBLE
SATURDAY NIGHT COOLING HIGHS INTO THE 40S TO AROUND 50 SUNDAY. THE
MODELS ARE IN GOOD AGREEMENT WITH A DOUBLE BARREL HIGH PRESSURE
SYSTEM OVER SCNTL CANADA AND THE CNTL ROCKIES. THIS WOULD PUT THE
BRAKES ON ANY SORT ARCTIC AIR AS THE MILDER PACIFIC HIGH ACROSS THE
ROCKIES DOMINATES THE COLDER ARCTIC AIR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1125 AM CST SUN FEB 14 2016
VFR CONDITIONS WILL CONTINUE FOR MOST OF WESTERN NEBRASKA THROUGH
MIDDAY MONDAY...AND STRATUS OVER NORTHERN/EASTERN NEBRASKA
AFFECTING KONL WILL SLOWLY LIFT THIS AFTERNOON. A FEW LIGHT RAIN
SHOWERS WILL MOVE THROUGH THE AREA THIS EVENING...BUT VISBY OR CIG
RESTRICTIONS ARE NOT ANTICIPATED. AMBIENT SURFACE WINDS WILL
GENERALLY STAY AROUND 10 KTS OUT OF THE WEST THROUGH THE FORECAST
PERIOD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNIVELY
LONG TERM...CDC
AVIATION...SNIVELY
AREA FORECAST DISCUSSION
NWS BISMARCK ND
331 PM CST SUN FEB 14 2016
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CST SUN FEB 14 2016
MILD WEATHER WILL CONTINUE THROUGH MONDAY...WITH SOME PATCHY FOG
POSSIBLE TONIGHT OVER CENTRAL ND AND AN INCREASING CHANCE OF LIGHT
RAIN OR SNOW OVER WESTERN AND CENTRAL ND MONDAY AFTERNOON.
FIRST OF ALL...WE HAVE REMOVED ANY MENTION OF FREEZING DRIZZLE IN
THE FORECAST FOR THE REMAINDER OF THE AFTERNOON GIVEN THE LACK OF
OBSERVATIONAL EVIDENCE OF IT OVER EAST CENTRAL ND THROUGH 21 UTC.
FORECAST SOUNDINGS IN PLACES LIKE JAMESTOWN SHOW THE STRATUS DECK
/LOW CLOUDS/ BEING WARMER THAN -12 C...WHICH SUPPORTS SUPERCOOLED
LIQUID DROPS AND NOT ICE CRYSTALS...BUT OMEGA IN THAT LAYER IS ON
ITS WAY DOWNWARD AND SO THE PROBABILITY OF FREEZING DRIZZLE WILL
ONLY LOWER THROUGH THE REST OF THE DAY.
TONIGHT...WE ADDED PATCHY FOG TO THE FORECAST OVER CENTRAL ND OUT
OF RESPECT TO SNOWMELT TODAY...INITIALLY-LIGHT WINDS WITHIN 1000
FT OF THE GROUND...AND SIMULATION OF ITS DEVELOPMENT IN THE 15-19
UTC RUNS OF THE OPERATIONAL AND EXPERIMENTAL HRRR AND THE 12 UTC
NAM-NEST. HOWEVER...FORECAST SOUNDINGS SUGGEST THE LOW LEVELS MAY
BECOME A BIT TOO TURBULENT FOR FOG IN MOST AREAS AFTER 09 UTC PER
INCREASING WESTERLY WINDS JUST ABOVE THE GROUND...WHICH PRODUCES
MODIFIED RICHARDSON NUMBERS GREATER THAN 0.00. OTHERWISE...WE ARE
EXPECTING A RELATIVELY MILD NIGHT WITH LOWS IN THE 20S F...AND IT
SHOULD BE DRY AFTER ANY LATE-AFTERNOON SHOWERS IN SOUTHWESTERN ND
DISSIPATE AS A WEAK SHORTWAVE TROUGH CONTINUES INTO SD.
ON MONDAY...THE 12 UTC GFS...ECMWF...AND NAM ALL SHOW A SHORTWAVE
TROUGH MOVING INTO WESTERN ND BY AFTERNOON. THAT WAVE CAN BE SEEN
CRASHING ONTO THE CENTRAL BRITISH COLUMBIA COASTLINE ON AFTERNOON
MOISTURE CHANNEL IMAGERY...AND GIVEN ITS APPARENT CIRCULATION AND
POST-TROUGH DARKENING ON THOSE SATELLITE IMAGES...MODEL GUIDANCE
APPEARS VERY REASONABLE IN SHOWING A MODERATE TO POSSIBLY STRONG
SURGE OF QG-FORCING CROSSING THE AREA BEGINNING MONDAY AFTERNOON.
WE ARE THUS ADVERTISING POPS OF 40+ PERCENT OVER MOST OF WESTERN
AND CENTRAL ND MONDAY AFTERNOON. PRECIPITATION TYPE WILL LIKELY
BE DRIVEN MAINLY BY BOUNDARY LAYER TEMPERATURES AS THE WARM LAYER
ALOFT WILL INITIALLY BE SUB-SATURATED IN SOUTHWEST ND /PROMOTING
WET BULB COOLING/...AND TOO COLD FOR MELTING ALOFT ELSEWHERE WITH
850-MB TEMPERATURES BELOW 1 C. WE THUS HAVE A MIX OF RAIN AND SNOW
IN THE FORECAST ACROSS THE AREA...WITH QPF FROM 18 TO 00 UTC OF
0.10 INCHES OR LESS PER THE 12 UTC MODEL SUITE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CST SUN FEB 14 2016
ACTIVE FLOW REMAINS OVER THE REGION FOR THE EARLY PORTION OF THE
WEEK...THEN WE FINALLY TRANSITION TO A MORE PROGRESSIVE FLOW
PATTERN FOR THE REMAINDER OF THE LONG TERM PERIOD.
MODELS TRENDING STRONGER WITH A S/WV TROUGH/CLIPPER SYSTEM MOVING
ACROSS THE NORTHERN PLAINS MONDAY AND MONDAY NIGHT. PRECIPITATION
TYPE BY MONDAY EVENING SHOULD BE ALL SNOW WITH MODELS IN AGREEMENT
WITH CAA LOWERING TEMPERATURES ALOFT TO BELOW FREEZING THROUGH THE
SATURATION LAYER. MAY SEE SOME LIGHT ACCUMULATIONS WITH THIS WAVE
GIVEN THE UPTICK IN QPF AND LIFT. CURRENT THINKING IS THAT THIS
WILL REMAIN SUB-ADVISORY TYPE SNOWFALL SO DID NOT MENTION IN THE
HWO WITH THIS FORECAST ISSUANCE.
THIS CLIPPER IS QUICKLY FOLLOWED BY ANOTHER WEAKER WAVE TUESDAY
THROUGH EARLY WEDNESDAY. THERMAL PROFILE SUGGEST ALL SNOW WITH
THIS S/WV.
BROAD UPPER LEVEL RIDGING WILL DRY THINGS OUT TOWARDS THURSDAY
ALONG WITH MILD/WELL ABOVE NORMAL TEMPERATURES IN THE 30S
EAST...40S NORTHWEST AND CENTRAL...AND MID/UPPER 50S OVER THE
SOUTHWEST. A GOOD SOUTHERLY RETURN FLOW WILL INCREASE MIXING AND
MAY LEAD TO EVEN WARMER DAYTIME HIGHS FOR THURSDAY THAN WHAT IS
CURRENTLY FORECAST. FOR NOW LEANED MORE CONSERVATIVE.
UPPER LEVEL S/WV TROUGH FOLLOWS THE RIDGE THURSDAY NIGHT/FRIDAY.
MODEL SPREAD STILL HIGH RIGHT NOW IN REGARDS TO THIS WAVE. MAY SEE
SOME IMPACTFUL WEATHER THOUGH ASSOCIATED WITH THIS TOWARDS THE
END OF THE WEEK...RIGHT NOW VERY UNCERTAIN BUT WILL BE WORTH
KEEPING AN EYE ON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 330 PM CST SUN FEB 14 2016
LINGERING MVFR CEILINGS FROM CENTRAL ND INTO THE JAMES RIVER VALLEY
COULD BRIEFLY LIFT INTO THE VFR RANGE IN THE LATE AFTERNOON AND
EVENING...BUT THEN A BRIEF WINDOW OF SOME FOG IS POSSIBLE TONIGHT
AND INTO THE EARLY MORNING HOURS ON MONDAY...FOLLOWED BY SOME LOW
STRATUS. ELSEWHERE...KISN AND KDIK SHOULD REMAIN IN VFR CONDITIONS
THROUGHOUT THE PERIOD. WINDS WILL GENERALLY REMAIN LIGHT OUT OF
THE WEST AND NORTHWEST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CJS
LONG TERM...NH
AVIATION...ZH/CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1235 PM CST SUN FEB 14 2016
.UPDATE...
ISSUED AT 1235 PM CST SUN FEB 14 2016
WE INCREASED HIGH TEMPERATURES OVER SOUTHWEST AND SOUTH CENTRAL ND
WITH THIS UPDATE AS TEMPERATURES BEHIND THE WARM FRONT IN LOCALES
WITH 2 INCHES OR LESS OF SNOW ON THE GROUND HAVE WARMED RAPIDLY
IN THE LAST FEW HOURS. WE ARE NOW ADVERTISING LOWER 40S F EVEN IN
BISMARCK/MANDAN THIS AFTERNOON...WHICH ADMITTEDLY MAY NOT BE QUITE
WARM ENOUGH SINCE IT IS ALREADY 40 F HERE AT 1830 UTC. ONLY MINOR
CHANGES WERE MADE TO OTHER FORECAST FIELDS FOR THIS AFTERNOON. WE
WILL CONSIDER THE POSSIBLE ADDITION OF PATCHY FOG TO TONIGHT WITH
THE NEXT FORECAST RELEASE GIVEN SNOWMELT TODAY.
UPDATE ISSUED AT 942 AM CST SUN FEB 14 2016
NO SIGNIFICANT CHANGES WITH THIS UPDATE. CUT PRECIPITATION CHANCES
AS THE SNOW HAS VACATED THE FORECAST AREA...BUT DID LEAVE A
MENTION OF PATCHY FREEZING DRIZZLE OVER THE EASTERN THIRD OF THE
FORECAST AREA...MAINLY THE JAMES RIVER VALLEY. EXPERIMENTAL HRRR
RUNS HAVE BEEN CONSISTENT...SHOWING FREEZING DRIZZLE ON THE BACK
EDGE OF THE SNOW. WHILE THE OPERATIONAL HRRR IS NOT SHOWING THE
SAME SCENARIO...EARLIER EXPERIMENTAL RUNS HANDLED THIS MORNINGS
FREEZING DRIZZLE WELL. LATEST RAP FORECAST SOUNDINGS OVER
JAMESTOWN ALSO SUPPORT THIS SCENARIO.
UPDATE ISSUED AT 634 AM CST SUN FEB 14 2016
OVERALL...NO SIGNIFICANT CHANGE WITH THIS FORECAST UPDATE OTHER
THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC. CONTINUED THE
WINTER WEATHER ADVISORY ACROSS CENTRAL NORTH DAKOTA WITH FREEZING
DRIZZLE STILL FAVORED UNDER THE STRATUS DECK WITH ICE CRYSTALS
LACKING THROUGH MUCH OF THE COLUMN AS OBSERVED ON THE 12 UTC KBIS
SOUNDING. HOWEVER...SATURATION AT THE TOP OF THE LOW LEVEL
MOISTURE LAYER DOES APPROACH -10 TO -12 C...ALLOWING FOR A
CHANGE OVER TO SNOW OCCASIONALLY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 241 AM CST SUN FEB 14 2016
MAIN CONCERN IN THE SHORT TERM IS FREEZING DRIZZLE THAT DEVELOPED
BEFORE MIDNIGHT - ON THE WESTERN EDGE OF THE AREA OF LIGHT SNOW THAT
CONTINUES TO MOVE EAST ACROSS THE STATE. WILL BE ADDING A WINTER
WEATHER ADVISORY BACK INTO SOUTH CENTRAL NORTH DAKOTA BECAUSE OF THE
FREEZING DRIZZLE...AND EXTENDING THE ADVISORY THAT ENCOMPASSES ALL
OF CENTRAL NORTH DAKOTA UNTIL NOON CST.
CURRENTLY...UPPER LEVEL SHORTWAVE TROUGH EXTENDED FROM MANITOBA
SOUTHWARD ACROSS THE CENTRAL/EASTERN DAKOTAS. A CIRCULATION WAS NOTED
IN THE SATELLITE PICS OVER SOUTH CENTRAL/SOUTHEASTERN SOUTH
DAKOTA...WITH ANOTHER CIRCULATION NOTED IN THE REGIONAL RADAR LOOPS
OVER THE TURTLE MOUNTAINS AND DEVILS LAKE BASIN. THE AREA OF SNOW
ASSOCIATED WITH THE SHORTWAVE CONTINUED TO PUSH EASTWARD...WITH THE
WESTERN EDGE OF THE SNOW NEAR BOTTINEAU AND EAST OF THE MINOT AREA
IN THE NORTH CENTRAL...AND IN THE JAMES RIVER BASIN. AT THE
SURFACE...A WARM FRONT EXTENDED FROM NEAR STANLEY TO GLEN ULLIN AND
EAST OF HETTINGER...WHERE WEST TO NORTHWEST WINDS HAD DEVELOPED AND
LOW CLOUDS WERE DISSIPATING.
FORECAST SOUNDINGS DID SHOW THAT ONCE THE SNOW ENDS IN CENTRAL NORTH
DAKOTA THAT A DEEP LAYER OF SUPERCOOLED AIR WITH NO ICE CRYSTALS
ABOVE IT WOULD DOMINATE CENTRAL NORTH DAKOTA. THE FREEZING DRIZZLE
DEVELOPED AT BISMARCK AND LIGHT RADAR RETURNS SURROUNDING THE
BISMARCK RADAR CONFIRM THAT LIGHT FOG PARTICLES/DRIZZLE WERE INTENSE
ENOUGH TO BE DETECTED BY RADAR. MENTION OF FOG WEST OF THE SNOW
BANDS ARE LIKELY ACCOMPANIED BY FREEZING DRIZZLE. THINKING AREA OF
PATCHY FREEZING DRIZZLE IS BETWEEN THE AREA OF SNOW IN THE EAST AND
THE WARM FRONT TO THE WEST. WILL ADDRESS THIS WITH THE WINTER
WEATHER ADVISORY IN PLACE FOR ALL OF CENTRAL NORTH DAKOTA.
THE WARM FRONT IS FORECAST TO MOVE EAST ACROSS THE STATE TODAY...AND
HIGHS SHOULD RANGE FROM AROUND 40 FAR SOUTHWEST TO AROUND 30 TURTLE
MOUNTAINS/JAMES VALLEY. WEAK SHORTWAVE ENERGY IN THE NORTHWEST FLOW
ALOFT MAY BRING SOME LIGHT RAIN TO FAR SOUTHWESTERN NORTH DAKOTA
THIS AFTERNOON. A MILD NIGHT TONIGHT WITH LIGHT WESTERLY WINDS AND
LOW TEMPERATURES IN THE 20S ARE EXPECTED.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 241 AM CST SUN FEB 14 2016
ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST.
THE 00 UTC SUITES ARE IN GOOD AGREEMENT ON A BROAD UPPER LEVEL
RIDGE BUILDING ACROSS THE CENTRAL CONUS THIS COMING WEEK...WITH
RESULTANT ABOVE NORMAL TEMPERATURES FOR THE PERIOD. THE 00 UTC
NAEFS MEAN 850 MB TEMPERATURE ANOMALIES ARE FORECAST TO CLIMB TO
THEIR 97.5 TO 99.5+ PERCENTILES BY THURSDAY ACROSS WESTERN AND
CENTRAL NORTH DAKOTA. THIS SUPPORTS THE POTENTIAL FOR WIDESPREAD
50S FOR HIGHS ALONG AND WEST OF THE MISSOURI RIVER BY
THURSDAY...POSSIBLY APPROACHING RECORD VALUES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1235 PM CST SUN FEB 14 2016
AREAS OF PATCHY FREEZING DRIZZLE AND SNOW FLURRIES ARE MAKING THEIR
WAY OUT OF CENTRAL NORTH DAKOTA AND INTO THE EASTERN PART OF THE
STATE. LOWER STRATUS CLOUDS WILL KEEP KMOT/KBIS/KJMS IN MVFR
CEILINGS THROUGH THE EARLY PART OF THIS AFTERNOON...WHILE
SCATTERED IFR CEILINGS WILL BE POSSIBLE OVER KJMS THROUGH 19Z.
CEILINGS WILL LIFT TO VFR FOR A BRIEF WINDOW OVER THESE SITES IN
THE LATE AFTERNOON AND EARLY EVENING HOURS...AND THEN A BRIEF
WINDOW OF SOME FOG MAY BE POSSIBLE LATE TONIGHT AND INTO THE EARLY
MORNING HOURS ON MONDAY...FOLLOWED BY SOME LOW STRATUS.
ELSEWHERE...KISN AND KDIK SHOULD REMAIN IN VFR CONDITIONS
THROUGHOUT THE PERIOD. WINDS WILL GENERALLY REMAIN LIGHT OUT OF
THE WEST AND NORTHWEST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...JV
LONG TERM...AYD
AVIATION...ZH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1213 PM EST SUN FEB 14 2016
.SYNOPSIS...
SNOW WILL OCCUR NORTH OF A WARM FRONT THAT WILL APPROACH FROM THE
SOUTHWEST TODAY AND LIFT THROUGH THE AREA TONIGHT. AN AREA OF LOW
PRESSURE WILL PASS JUST SOUTHEAST OF THE REGION MONDAY AFTERNOON
AND NIGHT. ANOTHER LOW PRESSURE SYSTEM WILL CROSS THE AREA TUESDAY
AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH TONIGHT/...
ADJUSTMENTS FOR THE NEAR TERM OF THE FORECAST WERE FOCUSED ON THE
SNOW POTENTIAL THIS AFTERNOON...WITH SOME SLIGHT ADJUSTMENTS TO
FORECAST NUMBERS REQUIRED. SOME MINOR CHANGES WERE ALSO MADE
OVERNIGHT AND GOING INTO MONDAY...BUT THE FORECAST THINKING FOR
THE SETUP FROM OVERNIGHT INTO TOMORROW HAS NOT CHANGED MUCH.
WATER VAPOR SATELLITE IMAGERY SHOWS A WELL-DEFINED SPIN IN
IOWA...ASSOCIATED WITH THE SHORTWAVE THAT IS MOVING TOWARD THE
REGION TODAY. AS THIS SHORTWAVE MOVES EAST...FORCING IS BEGINNING
TO INCREASE IN THE LOWER OHIO VALLEY...DRIVEN JUST AS MUCH BY
FORCING A LITTLE LOWER IN THE ATMOSPHERE. WITH HIGH PRESSURE
MOVING EAST OF THE OHIO VALLEY...A SWITCH TO SOUTHERLY FLOW HAS
OCCURRED...AND WARM FRONTAL PROCESSES ARE UNDERWAY. CONVERGENCE
AND ISENTROPIC ASCENT IS GRADUALLY INCREASING IN STRENGTH AHEAD OF
THE INCREASED SOUTHERLY FLOW...AND PRECIPITATION IN ILLINOIS /
WESTERN KENTUCKY / EASTERN MISSOURI HAS BECOME WIDESPREAD.
ALTHOUGH MODELS ARE IN STRONG AGREEMENT ON THIS OVERALL
SETUP...THERE ARE STILL SOME CONFLICTING FACTORS PREVENTING A
HIGH-CONFIDENCE FORECAST FOR THE EVENTUAL SNOWFALL NUMBERS. RECENT
HIGH-RESOLUTION MODEL RUNS AND SOME OF THE 06Z OPERATIONAL RUNS
HAVE DEFINITELY INDICATED A LITTLE STRONGER FORCING THAN PERHAPS
PREVIOUSLY INDICATED. CONSEQUENTLY...QPF AMOUNTS (ESPECIALLY OVER
THE FAR SOUTHWESTERN CWA) HAVE INCREASED AS WELL. OF COURSE...QPF
SHOULD ONLY BE USED AS ONE FACTOR IN THE FORECAST PROCESS...AND
NEEDS TO BE SCRUTINIZED. THE LOCATION AND STRENGTH OF THE FORCING
AND MOISTURE ARE OF GREATER CONCERN TO LOOK INTO. FOR
EXAMPLE...BOTH THE RECENT HRRR AND RAP RUNS HAVE AROUND A TENTH OF
AN INCH OF LIQUID EQUIVALENT IN THE SOUTHWESTERN ILN COUNTIES
BEFORE 18Z...VALUES THAT ARE SIMPLY NOT OCCURRING RIGHT NOW (WITH
JUST ONE OR TWO REPORTS OF SOME LIGHT SNOW FROM THE MOSTLY-VIRGA
ECHOES CURRENTLY MOVING THROUGH CENTRAL AND EASTERN KENTUCKY).
FURTHERMORE...SNOW RATIOS MUST BE CONSIDERED THROUGH THE DEPTH OF
THE THERMAL PROFILE...AND CANNOT BE BASED SOLELY ON SURFACE
TEMPERATURES. IN FACT...IT IS THE STRENGTH OF THE WARMING ALOFT
(LEADING TO THE ISENTROPIC ASCENT) THAT WILL HELP LIMIT SNOW
RATIOS...BY DEVELOPING A DEEP ISOTHERMAL LAYER OF ROUGHLY -8C TO
-10C FROM THE SURFACE THROUGH 700MB. THIS IS NOT ESPECIALLY
FAVORABLE FOR EFFICIENT SNOW PRODUCTION...AND WILL LIKELY KEEP
RATIOS AT OR BELOW 15:1. HOWEVER...THERE WILL BE A PERIOD WHERE
THE CONTRIBUTION OF FORCING FROM THE SHORTWAVE ALLOWS FOR ASCENT
THROUGH AN EVEN DEEPER LAYER...PERHAPS ALLOWING FOR A PERIOD OF AN
HOUR OR TWO WITH SOME HEAVIER SNOW RATES.
WITH ALL THE FACTORS CONSIDERED TOGETHER...SNOW NUMBERS WERE
INCREASED BY ABOUT A HALF INCH THROUGH THE CENTER OF THE ILN
FORECAST AREA...AND BY ALMOST AN INCH IN THE FAR SOUTH AND
SOUTHWEST. THE WSW PRODUCT WAS BROKEN OUT INTO TWO GROUPS TO
ALLOW FOR A 2-3 INCH FORECAST AND A 3-4 INCH FORECAST.
THE FORECAST THINKING DID NOT CHANGE MUCH WITH REGARDS TO THE
POTENTIAL FOR FREEZING DRIZZLE EARLY MONDAY MORNING. ONCE THE
DEEP-LAYER MOISTURE HAS DEPARTED...AND SATURATION IS LIMITED TO
BELOW -10C...ICE CRYSTALS ARE UNLIKELY TO BE INTRODUCED INTO THE
ATMOSPHERE. THOUGH STRONG FORCING WILL ALSO BE DEPARTED...WEAK
ISENTROPIC ASCENT WILL CONTINUE IN THE LOW-LEVELS...ALLOWING FOR
THE POTENTIAL FOR FREEZING DRIZZLE. THOUGH TEMPERATURES WILL BE
RISING GOING INTO MONDAY MORNING...THE COLD GROUND CONDITIONS
WILL BE VERY SLUGGISH IN THEIR RESPONSE...WITH SOME POTENTIAL FOR
LIGHT DEPOSITION OF ICE IF DRIZZLE IS ABLE TO DEVELOP.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
SHORT WAVE TRACKING OUT OF THE SOUTHERN PLAINS WILL HEAD INTO THE
CENTRAL APPALACHIANS MONDAY INTO MONDAY NIGHT. GUIDANCE IS COMING
INTO PRETTY GOOD AGREEMENT THAT THE ASSOCIATED SURFACE LOW WILL
MOVE FROM MIDDLE TENNESSEE INTO EASTERN KENTUCKY AND THEN WEST
VIRGINIA. SHIELD OF PRECIPITATION NORTH OF THE LOW WILL SPREAD
INTO THE SOUTHERN AND EASTERN ZONES MONDAY AFTERNOON THROUGH
MONDAY NIGHT. WARMER TEMPERATURES SHOULD RESULT IN MUCH OF THE
PRECIPITATION WILL BE IN THE FORM OF RAIN EXCEPT PERHAPS ON THE
NORTHWEST EDGE.
A NARROW SURFACE RIDGE WILL MOVE ACROSS THE REGION TUESDAY
MORNING PROVIDING A BRIEF RESPITE FROM PRECIPITATION. BUT THEN A
WELL DEVELOPED CLIPPER WILL MOVE ACROSS THE AREA TUESDAY AFTERNOON
AND NIGHT. 00Z NAM AND GFS ARE IN EXCELLENT AGREEMENT BUT WITH THE
ECMWF BEING A BIT SLOWER THERE IS SOME TIMING UNCERTAINTY.
CURRENTLY APPEARS THAT THIS WILL BRING SNOW IN THE NORTHERN PART
OF THE FORECAST AREA WITH RAIN OR SNOW IN THE SOUTH DEPENDING ON
THE LOW LEVEL TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ON WEDNESDAY...WILL GO WITH A DRY FORECAST...ALTHOUGH CONSIDERABLE
CAA STRATOCUMULUS IS EXPECTED.
FOR WEDNESDAY NIGHT INTO THURSDAY...HIGH PRESSURE WILL BUILD SOUTH
INTO THE OHIO VALLEY. SKIES ARE EXPECTED TO BECOME PARTLY CLOUDY.
MODELS DIFFERENT ON THE EXTENT OF COLD AIR FILTERING IN THE
REGION...SO HAVE SIDED WITH A WPC BLENDED APPROACH.
AS THE HIGH MOVES EAST THURSDAY NIGHT...A WARM FRONT IS FORECAST TO
APPROACH FROM THE WEST. WE SHOULD SEE AN INCREASE IN WAA INDUCED
CLOUDS. AS OF NOW...ANY PCPN GENERATED WITH THE WARM FRONT IS
EXPECTED TO STAY NORTHWEST OF THE AREA. OVERNIGHT LOWS WILL BE EARLY
FOLLOWED BY SLOWLY RISING TEMPERATURES AS WINDS INCREASE FROM THE
SOUTH.
FOR FRIDAY INTO FRIDAY NIGHT...LOW PRESSURE WILL TRAVERSE THE GREAT
LAKES AS A COLD FRONT PUSHES IN FROM THE NORTHWEST. MODELS VARY ON
HOW MUCH MOISTURE WILL BE PULLED NORTHWARD ALONG AND AHEAD OF THE
FRONT SYSTEM...ALONG WITH THE TIMING...SO HAVE GONE WITH A CHANCE OF
RAIN. FRIDAY CERTAINLY LOOKS TO BE THE WARMEST DAY OF THE EXTENDED
WITH TEMPERATURES RISING INTO THE 50S AREA WIDE.
ON SATURDAY...FRONT EXITS TO THE EAST...BUT CAA STRATOCUMULUS MOVES
INTO THE REGION. PCPN WILL MOVE EAST AS WELL. TEMPERATURES WILL COOL
INTO THE MID 40S TO LOWER 50S FOR HIGHS.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL BRIEFLY BEGIN THE TAF PERIOD...BEFORE
ACCUMULATING SNOW MOVES INTO THE REGION FROM THE WEST. THIS SNOW
IS EXPECTED TO LEAD TO PERIODS OF IFR VISIBILITIES DURING THE LATE
AFTERNOON AND EARLY EVENING. CEILINGS WILL ALSO LIKELY DROP TO THE
MVFR RANGE DURING THIS TIME FRAME.
ONCE THE MAIN ACCUMULATING SNOW HAS COME TO AN END...PRECIPITATION
WILL BECOME MUCH LIGHTER. HOWEVER...IT APPEARS THAT THERE WILL BE
A CONTINUED CHANCE FOR EITHER VERY LIGHT SNOW OR FREEZING DRIZZLE
TO DEVELOP. SINCE AT LEAST SOME FREEZING DRIZZLE IS EXPECTED...AND
WILL BE THE PRIMARY CONCERN FOR AVIATION...IT WAS INCLUDED AS THE
MAIN WEATHER TYPE IN THE TAFS. FREEZING DRIZZLE WILL BE POSSIBLE
UNTIL TEMPERATURES WARM ABOVE FREEZING AT SOME POINT MONDAY
MORNING. REGARDLESS OF HOW MUCH FREEZING DRIZZLE DEVELOPS...THERE
IS HIGH CONFIDENCE IN IFR (AND PROBABLY LIFR) CEILINGS DURING THIS
PART OF THE FORECAST.
FOR THE REST OF MONDAY...IT APPEARS THAT RAIN WILL MOVE INTO THE
REGION FROM THE SOUTH...THOUGH HOW MUCH REACHES THE TAF SITES IS
STILL UNCERTAIN. CEILINGS WILL BE VERY SLOW TO LIFT...AND IFR
CONDITIONS ARE EXPECTED THROUGH THE END OF THE FORECAST PERIOD.
OUTLOOK...MVFR/IFR CONDITIONS WILL CONTINUE ON MONDAY AFTERNOON
AND INTO MONDAY NIGHT...WITH ANOTHER WEATHER SYSTEM BRINGING
MVFR/IFR CONDITIONS AGAIN ON TUESDAY AND TUESDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR OHZ063>065-
070>074-077>082-088.
KY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR KYZ089>100.
IN...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR INZ066-
073>075-080.
&&
$$
SYNOPSIS...
NEAR TERM...HATZOS
SHORT TERM...
LONG TERM...HICKMAN
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
256 PM PST SUN FEB 14 2016
.SYNOPSIS...MOIST ONSHORE FLOW CONTINUES TO BRING RAIN AND DRIZZLE TO
THE COAST RANGE AND CASCADES THIS AFTERNOON...WITH OCCASIONAL LIGHT
RAIN IN THE LOWLANDS. THE SURFACE WARM FRONT WILL LIFT NORTH THROUGH
WASHINGTON TONIGHT...AND RAIN WILL DECREASE FROM THE SOUTH AS HIGHER
PRESSURE BUILDS INTO WESTERN OREGON. WEAK DISTURBANCES MOVING THROUGH
WASHINGTON WILL KEEP THE THREAT OF RAIN AT TIMES PORTLAND NORTHWARD
THROUGH TUESDAY WITH DRIER WEATHER TO THE SOUTH. A COLD FRONT IS
EXPECTED TO MOVE THROUGH WEDNESDAY AFTERNOON AND EVENING... FOLLOWED
BY LOWERING SNOW LEVELS IN THE CASCADES THURSDAY. ANOTHER PACIFIC
FRONT APPEARS LIKELY TO MOVE THROUGH THE FORECAST AREA THURSDAY NIGHT
AND FRIDAY.
&&
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...RAINFALL CONTINUES TO ADD
UP ALONG THE WASHINGTON AND FAR NORTH OREGON CASCADES THIS
AFTERNOON...WHERE AS MUCH AS 2-4 INCHES OF RAIN HAVE BEEN REPORTED
THUS FAR IN PLENTY OF UPSLOPE FLOW. ELSEWHERE...NWS DOPPLER RADAR
SEEMS TO BE INDICATING A DECREASE IN COVERAGE AND INTENSITY...THOUGH
COAST AND COAST RANGE RAWS STATIONS CONTINUE TO REPORT A FEW
HUNDREDTHS OF AN INCH PER HOUR. MOST OF THE RAIN HAS ENDED FOR THE
WILLAMETTE VALLEY AS THE BEST FORCING PUSHES NORTH AND EAST OF OUR
FORECAST AREA. MEANWHILE...W-SW 850 MB FLOW ON THE ORDER OF 35-45 KT
SHOULD BE ENOUGH TO KEEP SOME RAIN IN THE PICTURE TONIGHT IN THE
COAST RANGE AND CASCADES. RAIN RATES SHOULD EASE UP A BIT TONIGHT AS
THE DEEPEST MOISTURE TRANSPORT SHIFTS NORTH WITH THE WARM FRONT INTO
WASHINGTON.
HIGHER PRESSURE IS ALREADY BUILDING NORTHWARD INTO OREGON...BOTH AT
THE SURFACE AND ALOFT. THIS WILL ACCELERATE THE DRYING TREND
TONIGHT...ESPECIALLY SALEM SOUTHWARD. ADDITIONALLY...THIS SHOULD
FORCE THE MAIN BAROCLINIC ZONE AND DEEPEST MOISTURE TRANSPORT
NORTHWARD INTO VANCOUVER ISLAND AND NW WASHINGTON. MOST MODELS SHOW
AT LEAST 20-30 KT OF W-SW 850 MB FLOW CONTINUING PORTLAND NORTHWARD
INTO MONDAY...WHICH IN THIS MOIST AIR MASS SHOULD BE ENOUGH TO KEEP
SOME RAIN AND DRIZZLE GOING ACROSS MUCH OF SW WASHINGTON. EVEN KEPT
SOME LOW-END POPS IN THE FORECAST FOR THE PDX METRO...THOUGH THE BEST
CHANCE FOR RAIN WILL BE IN OROGRAPHICALLY FAVORED AREAS OF THE HIGHER
TERRAIN.
WITH WARMER AIR MOVING IN ALOFT...THE CHANCE FOR INVERSIONS AND
VALLEY FOG WILL BE INCREASING FOR THE EUGENE AREA TONIGHT/MON MORNING
THEN ACROSS MUCH OF CWA MON NIGHT/EARLY TUE. THIS COULD PUT A MONKEY
WRENCH IN THE TEMPERATURE FORECASTS...BUT FOR NOW GUIDANCE SUGGESTS
ANY FOG WILL BURN OFF EARLY ENOUGH FOR IT TO HAVE LITTLE IMPACT ON
MAX TEMPS. OTHERWISE...WITH 500 MB HEIGHTS AROUND 570 DAM AND 850 MB
TEMPS ON THE ORDER OF +4 TO +8 DEG C...EXPECT TEMPS TO REMAIN A FEW
DEGREES ABOVE NORMAL THROUGH TUESDAY AND PROBABLY WEDNESDAY AS WELL.
NIGHTS WILL BE UNSEASONABLY MILD DUE TO THE HIGH DEWPOINTS ASSOCIATED
WITH THIS MOIST AIR MASS.
MODELS ARE COMING INTO REASONABLE AGREEMENT THAT A COLD FRONT WILL
APPROACH THE PAC NW COAST EARLY WED...SPREADING RAIN ACROSS OUR
FORECAST AREA WEDNESDAY AFTERNOON AND EVENING. EXPECT A QUICK DROP IN
SNOW LEVELS AFTER THIS SYSTEM MOVES THROUGH...WITH SNOW LEVELS
POSSIBLY AS LOW AS THE CASCADE PASSES BY WED NIGHT. 18Z GFS SHOWS
925-850 MB WINDS REACHING 45-55 KT ALONG THE COAST WED AFTERNOON. IF
THIS VERIFIES IT COULD BE A BIT WINDY ALONG THE COAST JUST AHEAD OF
THE FRONT...THOUGH AM INCLINED TO BELIEVE THE NEUTRAL OR NEGATIVE
TILT TO THIS SYSTEM WILL KEEP THE STRONGEST WINDS SOUTH OF OUR
FORECAST AREA.WEAGLE
.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY...PROGRESSIVE PATTERN
CONTINUES THROUGH LATE NEXT WEEK...WITH BACK-TO-BACK SYSTEMS
BRINGING RAIN THROUGH AT LEAST FRIDAY. UPPER-LEVEL TROUGH DROPS DOWN
OUT OF THE GULF OF ALASKA MIDWEEK...BRINGING SNOW LEVELS MAYBE FAR
ENOUGH DOWN TO BRING SOME SNOW TO HIGHER ELEVATIONS IN THE CASCADE
FOOTHILLS THURSDAY. SNOW LEVELS COME UP A BIT ON FRIDAY AHEAD OF THE
NEXT FRONT MOVING THROUGH MID-DAY. SNOW LEVELS DROP BACK DOWN BEHIND
THIS FRONT FRIDAY NIGHT FOR ANOTHER BRIEF CHANCE FOR SNOW IN HIGHER
ELEVATIONS OF THE CASCADE FOOTHILLS EARLY SATURDAY. MODELS ARE
SUGGESTING RIDGING BUILDING BACK IN NEXT WEEKEND WHICH WOULD BRING
BACK DRY OFFSHORE FLOW. -MCCOY
&&
.AVIATION...WIDESPREAD MVFR INLAND AND IFR OVER THE COAST EARLY
THIS AFTERNOON. MOST RECENT GUIDANCE SUGGESTS SLOW IMPROVEMENT TO
MVFR/LOW-END VFR AFTER 18Z MON FOR THE INTERIOR VALLEYS. COASTAL
AREAS LIKELY TO REMAIN IFR TO MVFR THROUGH MON AFTERNOON. WARM
FRONT SLOWLY LIFT N LATE TONIGHT AND MON AND WOULD EXPECT AREAS S
OF A KONP-KCVO LINE TO HAVE MORE VFR AFTER 18Z MON. STRONG WLY
850 MB FLOW WILL MAINTAIN IFR OR WORSE CONDITIONS FOR THE HIGHER
TERRAIN THROUGH TONIGHT.
KPDX AND APPROACHES...LOW-END MVFR CIGS AROUND 1500 FT EXPECTED TO
PERSIST THROUGH MON MORNING. GOOD CHANCE THAT AREAS OF IFR WILL
DEVELOP OVERNIGHT. A GRADUAL IMPROVEMENT TO HIGH-END MVFR OR EVEN
LOW-END VFR 18Z MON. WEISHAAR
&&
.MARINE...WARM FRONT DRAPED OVER THE WATERS THIS AFTERNOON. WIND
SPEEDS HAVE EASED JUST A BIT FROM THIS MORNING...WITH ALL OUTER
BUOYS REPORTING 20 KT OR LESS AT 21Z. 14Z RUC A LITTLE WEAKER ON
FORECAST WIND SPEEDS TONIGHT COMPARED TO THE LATEST 12Z NAM. NAM
AND GFS ON TRACK SHOWING THE SLIGHT DECREASE IN BOUNDARY LAYER
WIND SPEEDS FOR THE AFTERNOON. HOWEVER...MODELS INCREASE THE WIND
SPEEDS TONIGHT. HAVE OPTED TO EXTEND THE SMALL CRAFT ADVISORY FOR
WIND OVER THE NRN WATERS THROUGH 08Z TUE. SRN WATERS WILL BE A
LITTLE TRICKY. NAM AND GFS SHOW A PERIOD OF SUB-ADVISORY WIND
SPEEDS THIS EVENING THROUGH ABOUT 08Z MON...THEN INDICATE A SLIGHT
INCREASE THEREAFTER. DECIDED TO GO WITH TWO DISTINCT SMALL CRAFT
ADVISORIES DUE TO THE TIME LENGTH OF FORECAST SUB-ADVISORY SPEEDS.
THE NEXT SIGNIFICANT SYSTEM REACHES THE WATERS LATE WED. GFS AND
ECMWF CONTINUE TO EXHIBIT DIFFERENCES...ESPECIALLY TIMING. FAVORED
THE ECMWF BUT WITH SLIGHTLY STRONGER WIND SPEEDS. POTENTIAL EXISTS
FOR LOW-END GALE GUSTS WED NIGHT. MODELS IN A LITTLE BETTER
AGREEMENT WITH THE FRI SYSTEM AND HAVE HIGH CONFIDENCE THAT SOLID
GALES WILL DEVELOP. HAVE INDICATED GUSTS TO 40 KT OVER THE OUTER
WATERS.
SEAS HOVERING AT OR JUST ABOVE 10 FT THIS MORNING. GUIDANCE
SUGGESTS LITTLE CHANGE THROUGH TONIGHT. SEAS LIKELY TO BE JUST
UNDER 10 FT MON...BUT THEN EXCEED 10 FT LATE MON AFTERNOON OR
EARLY EVENING. LATEST ENP RUN HAS SEAS INCREASING TO NEAR 15 FT
AROUND MID-WEEK. MODELS DIFFER OVER THE WEEKEND...BUT HAVE SOME
SEMBLANCE OF SURFACE HIGH PRES AND LIGHT OFFSHORE SURFACE FLOW.
THUS...THE 20 FT SEAS GUIDANCE SHOWED YESTERDAY FOR THE WEEKEND
ARE NO LONGER PRESENT. INSTEAD...LATEST SPECTRAL ANALYSIS FOR
BUOY 029 NOW SHOWS 10 TO 12 FT SUN. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM PST MONDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST MONDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM PST THIS EVENING FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM MIDNIGHT TONIGHT TO 6 PM
PST MONDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 1 PM
PST THIS AFTERNOON.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 7 PM
THIS EVENING TO MIDNIGHT PST TONIGHT.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 9 AM TO
NOON PST MONDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
325 PM EST SUN FEB 14 2016
.SYNOPSIS...
COLD HIGH PRESSURE MOVES EAST AND OFF THE MID ATLANTIC COAST TONIGHT.
A WARM FRONTAL BOUNDARY WORKS TOWARD THE TENNESSEE VALLEY BY THIS
EVENING WITH SNOW MOVING INTO THE MOUNTAINS. BY MONDAY...LOW
PRESSURE WORKS FROM THE LOWER MISSISSIPPI VALLEY TO THE SOUTHERN
APPALACHIANS. WITH COLD AIR IN PLACE EXPECT SNOW CHANGING TO A
WINTRY MIX MONDAY INTO MONDAY NIGHT. THIS SYSTEM MOVES EAST BY
TUESDAY AFTERNOON.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 325 PM EST SUNDAY...
WINTER STORM WARNINGS REMAIN IN EFFECT UNTIL NOON ON TUESDAY.
ARCTIC HIGH PRESSURE WILL TRAVEL EAST TONIGHT...AS A LONGWAVE TROUGH
DEVELOPS OVER THE CENTRAL UNITED STATES. WARM AND MOIST AIR FROM
THE ATLANTIC AND GULF OF MEXICO WILL OVERRUN THE ARCTIC AIR
RESULTING IN SNOW TONIGHT.
LIGHT SNOW HAS STARTED IN THE MOUNTAINS THIS AFTERNOON AND WILL
INCREASE IN COVERAGE AND SPREAD EASTWARD TONIGHT. PTYPE WILL STAY AS
ALL SNOW TONIGHT BECAUSE AIRMASS IS VERY COLD WITH THERMAL PROFILE
STAYING BELOW ZERO THROUGH 12Z MONDAY. SHAPED EVENING POPS TOWARDS A
BLEND OF HRRR AND HIRESW-ARW-EAST...THEN LEANED TOWARDS GFS. NAM
SOLUTION WAS TOO SLOW AND TOO DEEP WITH THE STORM...THUS FOLLOWED
WPC WEIGHTING MORE TOWARDS GFS. MODELS FAVOR A MOUNTAIN EMPIRE TO
WESTERN GREENBRIER CORRIDOR FOR HEAVIER SNOW BAND POTENTIAL BY
MIDNIGHT TONIGHT. SMALLER BANDS OF SNOW SHOULD SLIDE EAST TO THE
PIEDMONT THROUGH THE NIGHT. USED A SNOW TO LIQUID RATIOS CLOSE A
20:1 RANGE EARLY TONIGHT...THEN DROPPING TOWARD 15:1 BY 12Z MONDAY.
LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOWER TEENS IN THE
NORTHWEST MOUNTAINS TO THE LOWER 20S IN THE PIEDMONT.
AN UPPER LEVEL TROUGH WILL AMPLIFY OVER THE MISSISSIPPI RIVER VALLEY
TONIGHT AND MONDAY. SEVERAL SHORTWAVES WILL ROTATE AROUND THE UPPER
TROUGH. WARMER AIR WILL PUSH IN ALOFT AND MIX IN SLEET AND FREEZING
RAIN ON MONDAY. THE COLDER AIR WILL HOLD IN THE NORTH THE LONGEST.
TEMPERATURES WILL CLIMB IN THE LOWER TO MID 30S WEST OF I77 MONDAY
AFTERNOON...AND WARM AIR WILL ALSO PUSH NORTH INTO SOUTHEAST
PORTIONS OF FORECAST AREA MONDAY AFTERNOON. USED A TOPDOWN APPROACH
FOR WEATHER TYPE WITH PRIMARY MODEL GFS. ICE ACCUMULATIONS OF TWO-
TENTHS OF AN INCH OR LESS EXPECTED IN MOST AREAS THROUGH MONDAY
NIGHT. SNOW ACCUMULATIONS WILL VARY GREATLY BECAUSE OF THE WINTRY
MIX FROM 2 INCHES IN NORTH CAROLINA PIEDMONT TO AS MUCH AS 5 TO 10
INCHES IN NORTHWEST GREENBRIER BY MONDAY NIGHT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 322 PM EST SUNDAY...
MAY INIT WITHIN A LULL IN HEAVIER PRECIP AS A DRY SLOT REMAINS IN
BETWEEN THE DEPARTING NORTHERN STREAM SYSTEM AND THE AXIS OF BETTER
LIFT ASSOCIATED WITH THE ACTUAL SURFACE LOW APPROACHING FROM THE SW.
THIS MAINLY BETWEEN 00Z AND 06Z BEFORE THE NEXT SLUG OF DEEPER MOISTURE
ARRIVES OVER THE FAR WEST AROUND OR SHORTLY AFTER MIDNIGHT. WITH MODEL
CONSENSUS IN TRACKING THE MAIN WAVE EITHER OVER THE MOUNTAINS OR JUST
TO THE WEST...WILL CONTINUE TO SEE VERY STRONG WARM ADVECTION ALOFT.
THIS SEEN VIA MOST GUIDANCE SHOWING 50+ KTS AT 85H FROM THE SOUTH WHILE
TEMPS WITHIN THAT LAYER SURGE TO +4C TO +6C IN THE WARM NOSE. HOWEVER
THROUGH MIDNIGHT WILL STILL SEE MUCH OF THE REGION HAVE SURFACE TEMPS
NEAR OR JUST BELOW FREEZING MAKING FOR CONTINUED LIGHT FREEZING RAIN IN
ALL EXCEPT THE FAR WEST AND SE. APPEARS ADDED QPF THOUGH WILL BE LIGHT
AND MAINLY SUPPORTED BY WEAK LOW LEVEL ISENTROPIC LIFT BLUE RIDGE.
BIGGER CONCERN DEVELOPS AFTER MIDNIGHT WHEN THE HEAVIER BAND OF PRECIP
ALONG THE SURFACE TROUGH/WAVE SHIFTS EAST REACHING THE PIEDMONT
OVERNIGHT. MODELS SHOW CONTINUED WARMING IN THE BOUNDARY LAYER UNDER
THIS HEAVIER PRECIP AXIS AS COMBO OF THE DEEPENING WARMING ALOFT AND
PERHAPS PRECIP FALLING THROUGH THAT LAYER HELP TO BUMP MOST TO ABOVE
FREEZING FROM AFTER MIDNIGHT UNTIL EARLY TUESDAY. SINCE THIS MAY BE
SLOWER TO ERODE OVER THE EARLIER SNOW PACK...SLOWLY TRANSITIONING THE
PTYPE FROM FREEZING RAIN TO ALL RAIN FROM SOUTH TO NORTH BY MORNING.
THUS RUNNING WITH SOME LIGHT ADDED SNOW FAR NW EARLY ON...FOLLOWED BY
MORE SIGNIFICANT ICING ESPCLY BLUE RIDGE AND POINTS NORTH/EAST OF ROUTE
460 WHERE COULD SEE UP TO A QUARTER INCH OF ICE IN THE LATE EVENING TO
SHORTLY AFTER MIDNIGHT TIME FRAME. KEPT TEMPS NEAR FREEZING OR JUST
BELOW EARLY ON WITH SLOW RISES BY MORNING WHEN MOST SHOULD BE NEAR OR
JUST ABOVE FREEZING EXCLUDING THE VALLEYS UP NORTH. ALSO IF TEMPS END
UP WARMER AND QPF IS MORE THEN POTENTIAL FOR FLOODING ESPCLY EAST AS
MODELS SHOW A GOOD INCH OF QPF BLUE RIDGE EAST OVERNIGHT ON TOP OF
EARLIER SNOW/ICE AND FROZEN GROUND. THEREFORE ADDED MENTION TO THE HWO
FOR POSSIBLE FLOOD WATCH CONCERNS ON THE HEELS OF THE WINTER STORM
HEADLINES BY TUESDAY.
SYSTEM GOES NEGATIVE TILT AND QUICKLY EXITS BY TUESDAY AFTERNOON
ALLOWING COLD ADVECTION TO KICK BACK IN ESPCLY MOUNTAINS WHERE MAY
SWITCH TO SNOW SHOWERS WESTERN SLOPES. ELSEWHERE AFTER EARLY HIGH POPS
EAST EXPECT A BREAK UNDER WEAK SUBSIDENCE AHEAD OF YET ANOTHER DIGGING
UPSTREAM CLIPPER THAT WILL BE APPROACHING THE WEST LATE IN THE DAY.
COULD ALSO SEE SOME BREAKS DEVELOP THAT SHOULD ALLOW TEMPS TO RECOVER
BACK INTO THE 30S/40S MOUNTAINS AND POSSIBLY LOW 50S PIEDMONT.
THE CLIPPER GLIDES IN FROM THE WEST ON THE TAIL OF THE DEPARTING SYSTEM
TUESDAY NIGHT WITH TEMPS ALOFT COLD ENOUGH FOR A PERIOD OF SNOW
MOUNTAINS AND RAIN/SNOW EAST OVERNIGHT. LATEST MODELS SUGGEST AN INCH
OR TWO OF SNOW COULD OCCUR ACROSS THE HIGHER WESTERN ELEVATIONS BUT
LITTLE ELSEWHERE AS TEMPS MARGINAL HEADING EAST OF THE BLUE RIDGE. THUS
INCLUDING SOME HIGH CHANCE POPS WEST...AND LOW POPS TO JUST EAST OF THE
MOUNTAINS FOR NOW. LOWS MAINLY UPPER 20S TO LOW/MID 30S EAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EST SUNDAY...
UPPER TROUGH WILL LINGER WEDNESDAY BEHIND A DEPARTING CLIPPER THAT
SHOULD CONTINUE TO DRIVE UPSLOPE FLOW...PRIMARILY ACROSS THE WESTERN
SLOPES WEDNESDAY INTO WEDNESDAY NIGHT. THIS SUPPORTS KEEPING ADDED SNOW
SHOWERS OVER THE WEST ESPCLY WEDNESDAY BEFORE TAPERING OFF WEDNESDAY
NIGHT AS WEAK HIGH PRESSURE BUILDS IN. THUS KEEPING CHANCE POPS OVER
THE FAR WEST INTO LATE WEDNESDAY NIGHT. SHORTWAVE RIDGING STARTS TO
TAKE SHAPE THURSDAY AS CHILLY HIGH PRESSURE SHIFTS TO THE NORTH AND
MUCH DRIER AIR WORKS IN. THIS WILL KEEP TEMPS CLOSER TO NORMAL LEVELS
BY THURSDAY ALTHOUGH STILL WELL INTO THE 20S AT NIGHT.
A MUCH MORE TRANQUIL AND NEEDED WARMER SCENARIO TO UNFOLD FROM FRIDAY
INTO THE WEEKEND WITH OVERALL ZONAL FLOW IN PLACE AS THE MAJORITY OF
ANY COLD AIR REMAINS TO THE NORTH. WILL SEE A WEAK COOL FRONT SNEAK
THROUGH WITH PERHAPS A FEW MOUNTAIN RAIN SHOWERS FRIDAY NIGHT INTO
SATURDAY...AND AHEAD OF ANOTHER FRONT SUNDAY...OTHERWISE KEEPING THINGS
DRY. THIS ALONG WITH MUCH WARMER 85H TEMPS SUPPORTS HIGHS 50-55
FRIDAY...50S TO NEAR 60 PIEDMONT SATURDAY...AND OVERALL 50S ON SUNDAY.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
AS OF 1234 PM EST SUNDAY...
POOR FLYING CONDITIONS EXPECTED DURING THE TAF PERIOD BECAUSE OF WINTER
STORM WITH SNOW MIXED WITH SLEET AND FREEZING RAIN. GUSTY
SOUTHEAST WINDS ARE ALSO POSSIBLE ALONG THE RIDGES. PILOTS SHOULD
WATCH FOR MOUNTAIN OBSCURATIONS.
VFR CEILINGS THIS AFTERNOON WILL LOWER TO MVFR IN CLOUDS AND
SNOW LATE THIS AFTERNOON INTO TONIGHT. WARM FRONT AND SNOW WILL
MOVE INTO THE WESTERN AREAS BY 22Z...AND SHIFT EAST TONIGHT. LOOK
FOR VSBYS/CIGS TO DROP TO MVFR AND LOWER ESPECIALLY WEST OF THE
BLUE RIDGE BY 06Z...WITH IFR CIGS/VSBYS SPREADING EAST OVERNIGHT.
LIGHT WINDS WILL BECOME SOUTHEAST THIS AFTERNOON INTO TONIGHT
WITH SOME GUSTS OVER BLF TO 20KTS AFTER 00Z MONDAY. EXPECT SNOW
SWITCHING TO SLEET/FREEZING RAIN MONDAY WITH THIS MIX INTO MONDAY
NIGHT AND EARLY TUESDAY. MVFR TO IFR CIGS/VSBYS TO REMAIN. SOME
RAIN IS EXPECTED AT LEAST DAN/BLF AS WARMER SURGE OF AIR RIDES IN
TUESDAY.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED DISCUSSION...
THIS STORM EXITS TUESDAY AFTERNOON...BUT IS FOLLOWED QUICKLY BY A CLIPPER
SYSTEM THAT MAY IMPACT THE AREA FOR TUESDAY NIGHT-WEDNESDAY...POSSIBLY
RESULTING IN THE CONTINUATION OF POOR FLYING CONDITIONS.
HIGH PRESSURE BUILDS IN THURSDAY WITH VFR RETURNING.
&&
.CLIMATE...
COLDEST AIR OF THE SEASON HAS SETTLED OVER THE MID ATLANTIC
REGION. ROANOKE...DANVILLE...AND BLUEFIELD SET RECORD LOW
TEMPERATURES SUNDAY MORNING. SEE RECORD EVENT REPORT (RER) FOR
MORE DETAILS. SEVERAL CLIMATE SITES MAY BREAK RECORDS FOR LOW
MAXIMUM TEMPERATURES TODAY. THE CURRENT RECORDS ARE LISTED BELOW.
SUNDAY 02/14/2016
SITE LOMAX YEAR
KBLF 16 1960
KDAN 32 1986
KLYH 24 1905
KROA 26 1986
KRNK 24 1986
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR NCZ001>006-
018>020.
WV...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...JH/WP
NEAR TERM...KK
SHORT TERM...JH
LONG TERM...JH
AVIATION...KK/WP
CLIMATE...CF