Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/13/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
931 AM MST SUN JAN 11 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE TO BE THE STORY THROUGH THE EARLY
PART OF THIS WEEK...AS A SERIES OF FAST MOVING TROUGHS CONTINUE TO
MOVE THROUGH THE DESERT SOUTHWEST. SHOWERS WILL ONCE AGAIN BE
POSSIBLE THIS AFTERNOON INTO MONDAY MORNING...FOLLOWED BY A
SLIGHT CHANCE AGAIN EARLY TUESDAY. HIGH PRESSURE WILL RETURN TO THE
AREA BY MID WEEK WITH DRY WEATHER AND SLOWLY INCREASING TEMPERATURES
EXPECTED FROM WEDNESDAY INTO NEXT WEEKEND.
&&
.DISCUSSION...
LATEST SATELLITE IMAGERY SHOWS A MODESTLY IMPRESSIVE SHORTWAVE
TROUGH OVER SOUTHERN CALIFORNIA WITH THE PV ANOMALY CENTERED ALONG
THE SOUTHERN CALIFORNIA COAST. UPPER LEVEL ANALYSIS SHOWS A RATHER
COMPACT...BUT STRONG JET STREAK ALONG THE BASE OF THE UPPER TROUGH.
THIS WILL PROVIDE SOME NECESSARY LIFT FOR SHOWER DEVELOPMENT TODAY
AND TONIGHT. IR IMAGERY SHOWS AN EXTENSIVE AREA OF STRATO-CU
STREAMING NORTHEASTWARD OVER BAJA AND SOUTHEAST CALIFORNIA IN AN
AREA OF 0.75 TO 1.00 INCH PRECIPITABLE WATER. ISOLATED SHOWERS HAVE
BEEN FAIRLY PERSISTENT ACROSS PORTIONS OF SOUTHEAST CALIFORNIA SO
FAR THIS MORNING AND EXPECTING THESE TO INCREASE IN COVERAGE
SOMEWHAT BY LATE AFTERNOON AS THE PV ANOMALY SWINGS THROUGH. AM ALSO
ANTICIPATING SOME SHOWER DEVELOPMENT OVER THE GULF OF CALIFORNIA OR
NORTHWEST SONORA MEXICO THIS AFTERNOON WHICH WILL MOVE INTO YUMA
COUNTY BY LATE THIS AFTERNOON AND THROUGH THE REST OF SOUTH-CENTRAL
ARIZONA THIS EVENING. HAVE INCREASED POPS IN THESE AREAS INTO THE
CHANCE CATEGORY AND KEEPING THE LIKELY WORDING FROM PHOENIX EASTWARD
FOR LATE THIS EVENING INTO THE OVERNIGHT. RAINFALL AMOUNTS ARE NOT
EXPECTED TO BE MUCH WITH MOST LOCATIONS SEEING UP TO A TENTH OF AN
INCH...BUT SOME LOCALIZED SPOTS SHOULD RECEIVE A QUARTER OF AN
INCH.
&&
.PREVIOUS DISCUSSION...
THE LOW TO THE WEST OF LOS ANGELES HAS BEEN WELL ADVERTISED FOR THE
PAST SEVERAL DAYS...HOWEVER IT WOULD SUBJECTIVELY APPEAR THAT IT IS
A BIT MORE INTENSE THAN THE 00Z MODELS INDICATED. 00Z NAM AND GFS
AND TO SOME EXTENT THE EUROPEAN DON`T INDICATE ANY PRECIPITATION
ACROSS SOUTHERN CALIFORNIA THIS MORNING AND THIS IS OBVIOUSLY
INCORRECT. HRRR AND HI-RES MODELS ARE ALSO STRUGGLING A BIT AT THE
MOMENT BUT THE PARALLEL GFS /13KM/ SEEMS TO HAVE A DECENT HANDLE ON
THE SITUATION AND APPEARS TO HAVE INITIALIZED THE BEST OF ANY
AVAILABLE MODEL. GFS13 SUGGESTS THE LOW WILL MOVE ONSHORE LATER THIS
MORNING WITH PRECIPITATION DEVELOPING OVER ARIZONA LATER THIS
AFTERNOON/EVENING AS IT TAPS INTO SOMEWHAT HIGHER MID/LOWER
TROPOSPHERIC MOISTURE. MODEL QPF OVER THE PAST FEW DAYS HAS NEVER
BEEN MUCH MORE THAN A FEW HUNDREDTHS TO A TENTH OF AN INCH ACROSS
THE DESERTS /CLOSER TO A QUARTER OF AN INCH EAST OF PHOENIX/ AND
THIS STILL HOLDS TRUE WITH TODAY`S 00Z MODELS /INCLUDING THE GFS13/.
LOOKS LIKE A HIGH POP...LOW QPF EVENT. BUMPED UP POPS QUITE A BIT
THIS EVENING AND OVERNIGHT FOR ARIZONA ALTHOUGH SOUTHEAST CALIFORNIA
MAY END UP MISSING OUT ON THE MAJORITY OF THE RAINFALL. TIMING IS
LARGELY UNCHANGED FROM WHAT I INHERITED /06Z-18Z MONDAY IS THE
PRIMARY TIME FOR RAIN CHANCES/.
SHOWERS WILL TAPER OFF QUICKLY MONDAY NIGHT YET MOISTURE WILL REMAIN
SOMEWHAT ELEVATED BEHIND THE DEPARTING TROUGH. ON ITS HEELS WILL BE
THE SYSTEM PRESENTLY WEST OF WASHINGTON/OREGON AS IT IS FORECAST TO
DIVE SOUTHWARD THROUGH THE GREAT BASIN AND INTO ARIZONA TUESDAY
MORNING. AS THERE WILL BE SOME MOISTURE IN PLACE AND THE COLD CORE
OF THE LOW WILL PASS SOMEWHAT CLOSE TO THE FORECAST AREA...I WILL
RETAIN AT LEAST A 20-30 POP EAST OF PHOENIX FOR TUESDAY/TUESDAY
AFTERNOON PER SREF AND NAEFS GUIDANCE. HOWEVER THE OVER-LAND
TRAJECTORY OF THIS TROUGH SHOULD MITIGATE WIDESPREAD PRECIPITATION
ACROSS THE REST OF THE AREA.
LOOKING AHEAD TO WEDNESDAY AND BEYOND...RIDGING WILL RETURN TO THE
AREA BUT NOT NEARLY TO THE EXTENT AS WAS SEEN A FEW DAYS AGO. THIS
SHOULD RESULT IN GRADUALLY INCREASING TEMPERATURES AND LITTLE TO NO
CHANCE OF PRECIPITATION ACROSS THE AREA. HIGHS WILL EVENTUALLY CREEP
BACK INTO THE MID 70S BY LATE WEEK/NEXT WEEKEND.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT INCREASING CLOUD COVER AND CIGS LOWERING TO AROUND 7KFT AT
TIMES AFTER 20Z THIS AFTERNOON...AND CONTINUING OVERNIGHT BEFORE
BECOMING SCATTERED AOA 9KFT LATE MONDAY MORNING. ORGANIZED SHOWERS
SHOULD HOLD OFF UNTIL LATER THIS EVENING/AFTER 04Z MONDAY. SURFACE
WINDS WILL REMAIN VERY LIGHT WITH PROLONGED PERIODS OF VARIABLE
DIRECTION THROUGH AT LEAST 12 MONDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
TUESDAY WILL SEE THE FINAL IN A SERIES OF TROUGHS MOVE THROUGH THE
AREA. LOOKS LIKE THE BEST CHANCE OF PRECIPITATION WILL BE IN THE
MOUNTAINS EAST OF PHOENIX. SHOWERS SHOULD TAPER OFF QUICKLY TUESDAY
NIGHT WITH DRY WEATHER FORECAST WEDNESDAY INTO THE WEEKEND. THERE
COULD ALSO BE SOME LOCALIZED BREEZINESS WITH THE TUESDAY SYSTEM
ESPECIALLY DOWN THE COLORADO RIVER AND ACROSS THE RIDGETOPS EAST OF
PHOENIX. NOTHING HIGH ENOUGH TO WARRANT ANY FIRE WEATHER HEADLINES
THOUGH. AS FOR MOISTURE...HUMIDITIES WILL DROP A BIT FROM MID WEEK
ONWARD YET AFTERNOON READINGS WILL ONLY DROP INTO THE 20-30 PERCENT
RANGE WITH GOOD OVERNIGHT RECOVERIES EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...LEINS
AVIATION...MEYERS
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION...CORRECTED
NWS PHOENIX AZ
600 AM MST SUN JAN 11 2015
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE TO BE THE STORY THROUGH THE EARLY
PART OF THIS WEEK...AS A SERIES OF FAST MOVING TROUGHS CONTINUE TO
MOVE THROUGH THE DESERT SOUTHWEST. SHOWERS WILL ONCE AGAIN BE
POSSIBLE LATE TONIGHT INTO MONDAY MORNING...FOLLOWED BY A SLIGHT
CHANCE AGAIN EARLY TUESDAY. HIGH PRESSURE WILL RETURN TO THE AREA BY
MID WEEK WITH DRY WEATHER AND SLOWLY INCREASING TEMPERATURES
EXPECTED FROM WEDNESDAY INTO NEXT WEEKEND.
&&
.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY CONTINUES TO INDICATE AN ACTIVE
PATTERN ACROSS THE WESTERN CONUS. THE VERY WEAK TROUGH THAT BROUGHT
A FEW LIGHT RAIN SHOWERS TO THE REGION ON SATURDAY WAS BARELY
VISIBLE ACROSS NEW MEXICO...MEANWHILE A COMPACT UPPER LOW WAS
SPINNING UP WEST OF LOS ANGELES AND ANOTHER WEAKER SYSTEM WAS
LOCATED OFF THE WASHINGTON/OREGON COAST NEAR 45N/135W. ACROSS THE
REGION AS OF 0845Z THIS MORNING...CONDITIONS WERE MOSTLY DRY
ALTHOUGH REGIONAL RADAR IMAGERY SUGGESTED A FEW SHOWERS WERE TRYING
TO SPILL OVER THE COASTAL MOUNTAINS INTO JOSHUA TREE NATIONAL PARK.
TEMPS WERE GENERALLY IN THE LOWER 50S ACROSS THE DESERTS WITH NEARLY
CALM WINDS AT ALL SITES.
THE LOW TO THE WEST OF LOS ANGELES HAS BEEN WELL ADVERTISED FOR THE
PAST SEVERAL DAYS...HOWEVER IT WOULD SUBJECTIVELY APPEAR THAT IT IS
A BIT MORE INTENSE THAN THE 00Z MODELS INDICATED. 00Z NAM AND GFS
AND TO SOME EXTENT THE EUROPEAN DON`T INDICATE ANY PRECIPITATION
ACROSS SOUTHERN CALIFORNIA THIS MORNING AND THIS IS OBVIOUSLY
INCORRECT. HRRR AND HI-RES MODELS ARE ALSO STRUGGLING A BIT AT THE
MOMENT BUT THE PARALLEL GFS /13KM/ SEEMS TO HAVE A DECENT HANDLE ON
THE SITUATION AND APPEARS TO HAVE INITIALIZED THE BEST OF ANY
AVAILABLE MODEL. GFS13 SUGGESTS THE LOW WILL MOVE ONSHORE LATER THIS
MORNING WITH PRECIPITATION DEVELOPING OVER ARIZONA LATER THIS
AFTERNOON/EVENING AS IT TAPS INTO SOMEWHAT HIGHER MID/LOWER
TROPOSPHERIC MOISTURE. MODEL QPF OVER THE PAST FEW DAYS HAS NEVER
BEEN MUCH MORE THAN A FEW HUNDREDTHS TO A TENTH OF AN INCH ACROSS
THE DESERTS /CLOSER TO A QUARTER OF AN INCH EAST OF PHOENIX/ AND
THIS STILL HOLDS TRUE WITH TODAY`S 00Z MODELS /INCLUDING THE GFS13/.
LOOKS LIKE A HIGH POP...LOW QPF EVENT. BUMPED UP POPS QUITE A BIT
THIS EVENING AND OVERNIGHT FOR ARIZONA ALTHOUGH SOUTHEAST CALIFORNIA
MAY END UP MISSING OUT ON THE MAJORITY OF THE RAINFALL. TIMING IS
LARGELY UNCHANGED FROM WHAT I INHERITED /06Z-18Z MONDAY IS THE
PRIMARY TIME FOR RAIN CHANCES/.
SHOWERS WILL TAPER OFF QUICKLY MONDAY NIGHT YET MOISTURE WILL REMAIN
SOMEWHAT ELEVATED BEHIND THE DEPARTING TROUGH. ON ITS HEELS WILL BE
THE SYSTEM PRESENTLY WEST OF WASHINGTON/OREGON AS IT IS FORECAST TO
DIVE SOUTHWARD THROUGH THE GREAT BASIN AND INTO ARIZONA TUESDAY
MORNING. AS THERE WILL BE SOME MOISTURE IN PLACE AND THE COLD CORE
OF THE LOW WILL PASS SOMEWHAT CLOSE TO THE FORECAST AREA...I WILL
RETAIN AT LEAST A 20-30 POP EAST OF PHOENIX FOR TUESDAY/TUESDAY
AFTERNOON PER SREF AND NAEFS GUIDANCE. HOWEVER THE OVER-LAND
TRAJECTORY OF THIS TROUGH SHOULD MITIGATE WIDESPREAD PRECIPITATION
ACROSS THE REST OF THE AREA.
LOOKING AHEAD TO WEDNESDAY AND BEYOND...RIDGING WILL RETURN TO THE
AREA BUT NOT NEARLY TO THE EXTENT AS WAS SEEN A FEW DAYS AGO. THIS
SHOULD RESULT IN GRADUALLY INCREASING TEMPERATURES AND LITTLE TO NO
CHANCE OF PRECIPITATION ACROSS THE AREA. HIGHS WILL EVENTUALLY CREEP
BACK INTO THE MID 70S BY LATE WEEK/NEXT WEEKEND.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT INCREASING CLOUD COVER AND CIGS LOWERING TO AROUND 7KFT AT
TIMES AFTER 20Z THIS AFTERNOON...AND CONTINUING OVERNIGHT BEFORE
BECOMING SCATTERED AOA 9KFT LATE MONDAY MORNING. ORGANIZED SHOWERS
SHOULD HOLD OFF UNTIL LATER THIS EVENING/AFTER 04Z MONDAY. SURFACE
WINDS WILL REMAIN VERY LIGHT WITH PROLONGED PERIODS OF VARIABLE
DIRECTION THROUGH AT LEAST 12 MONDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
TUESDAY WILL SEE THE FINAL IN A SERIES OF TROUGHS MOVE THROUGH THE
AREA. LOOKS LIKE THE BEST CHANCE OF PRECIPITATION WILL BE IN THE
MOUNTAINS EAST OF PHOENIX. SHOWERS SHOULD TAPER OFF QUICKLY TUESDAY
NIGHT WITH DRY WEATHER FORECAST WEDNESDAY INTO THE WEEKEND. THERE
COULD ALSO BE SOME LOCALIZED BREEZINESS WITH THE TUESDAY SYSTEM
ESPECIALLY DOWN THE COLORADO RIVER AND ACROSS THE RIDGETOPS EAST OF
PHOENIX. NOTHING HIGH ENOUGH TO WARRANT ANY FIRE WEATHER HEADLINES
THOUGH. AS FOR MOISTURE...HUMIDITIES WILL DROP A BIT FROM MID WEEK
ONWARD YET AFTERNOON READINGS WILL ONLY DROP INTO THE 20-30 PERCENT
RANGE WITH GOOD OVERNIGHT RECOVERIES EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...MEYERS
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
158 AM MST SUN JAN 11 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE TO BE THE STORY THROUGH THE EARLY
PART OF THIS WEEK...AS A SERIES OF FAST MOVING TROUGHS CONTINUE TO
MOVE THROUGH THE DESERT SOUTHWEST. SHOWERS WILL ONCE AGAIN BE
POSSIBLE LATE TONIGHT INTO MONDAY MORNING...FOLLOWED BY A SLIGHT
CHANCE AGAIN EARLY TUESDAY. HIGH PRESSURE WILL RETURN TO THE AREA BY
MID WEEK WITH DRY WEATHER AND SLOWLY INCREASING TEMPERATURES
EXPECTED FROM WEDNESDAY INTO NEXT WEEKEND.
&&
.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY CONTINUES TO INDICATE AN ACTIVE
PATTERN ACROSS THE WESTERN CONUS. THE VERY WEAK TROUGH THAT BROUGHT
A FEW LIGHT RAIN SHOWERS TO THE REGION ON SATURDAY WAS BARELY
VISIBLE ACROSS NEW MEXICO...MEANWHILE A COMPACT UPPER LOW WAS
SPINNING UP WEST OF LOS ANGELES AND ANOTHER WEAKER SYSTEM WAS
LOCATED OFF THE WASHINGTON/OREGON COAST NEAR 45N/135W. ACROSS THE
REGION AS OF 0845Z THIS MORNING...CONDITIONS WERE MOSTLY DRY
ALTHOUGH REGIONAL RADAR IMAGERY SUGGESTED A FEW SHOWERS WERE TRYING
TO SPILL OVER THE COASTAL MOUNTAINS INTO JOSHUA TREE NATIONAL PARK.
TEMPS WERE GENERALLY IN THE LOWER 50S ACROSS THE DESERTS WITH NEARLY
CALM WINDS AT ALL SITES.
THE LOW TO THE WEST OF LOS ANGELES HAS BEEN WELL ADVERTISED FOR THE
PAST SEVERAL DAYS...HOWEVER IT WOULD SUBJECTIVELY APPEAR THAT IT IS
A BIT MORE INTENSE THAN THE 00Z MODELS INDICATED. 00Z NAM AND GFS
AND TO SOME EXTENT THE EUROPEAN DON`T INDICATE ANY PRECIPITATION
ACROSS SOUTHERN CALIFORNIA THIS MORNING AND THIS IS OBVIOUSLY
INCORRECT. HRRR AND HI-RES MODELS ARE ALSO STRUGGLING A BIT AT THE
MOMENT BUT THE PARALLEL GFS /13KM/ SEEMS TO HAVE A DECENT HANDLE ON
THE SITUATION AND APPEARS TO HAVE INITIALIZED THE BEST OF ANY
AVAILABLE MODEL. GFS13 SUGGESTS THE LOW WILL MOVE ONSHORE LATER THIS
MORNING WITH PRECIPITATION DEVELOPING OVER ARIZONA LATER THIS
AFTERNOON/EVENING AS IT TAPS INTO SOMEWHAT HIGHER MID/LOWER
TROPOSPHERIC MOISTURE. MODEL QPF OVER THE PAST FEW DAYS HAS NEVER
BEEN MUCH MORE THAN A FEW HUNDREDTHS TO A TENTH OF AN INCH ACROSS
THE DESERTS /CLOSER TO A QUARTER OF AN INCH EAST OF PHOENIX/ AND
THIS STILL HOLDS TRUE WITH TODAY`S 00Z MODELS /INCLUDING THE GFS13/.
LOOKS LIKE A HIGH POP...LOW QPF EVENT. BUMPED UP POPS QUITE A BIT
THIS EVENING AND OVERNIGHT FOR ARIZONA ALTHOUGH SOUTHEAST CALIFORNIA
MAY END UP MISSING OUT ON THE MAJORITY OF THE RAINFALL. TIMING IS
LARGELY UNCHANGED FROM WHAT I INHERITED /06Z-18Z MONDAY IS THE
PRIMARY TIME FOR RAIN CHANCES/.
SHOWERS WILL TAPER OFF QUICKLY MONDAY NIGHT YET MOISTURE WILL REMAIN
SOMEWHAT ELEVATED BEHIND THE DEPARTING TROUGH. ON ITS HEELS WILL BE
THE SYSTEM PRESENTLY WEST OF WASHINGTON/OREGON AS IT IS FORECAST TO
DIVE SOUTHWARD THROUGH THE GREAT BASIN AND INTO ARIZONA TUESDAY
MORNING. AS THERE WILL BE SOME MOISTURE IN PLACE AND THE COLD CORE
OF THE LOW WILL PASS SOMEWHAT CLOSE TO THE FORECAST AREA...I WILL
RETAIN AT LEAST A 20-30 POP EAST OF PHOENIX FOR TUESDAY/TUESDAY
AFTERNOON PER SREF AND NAEFS GUIDANCE. HOWEVER THE OVER-LAND
TRAJECTORY OF THIS TROUGH SHOULD MITIGATE WIDESPREAD PRECIPITATION
ACROSS THE REST OF THE AREA.
LOOKING AHEAD TO WEDNESDAY AND BEYOND...RIDGING WILL RETURN TO THE
AREA BUT NOT NEARLY TO THE EXTENT AS WAS SEEN A FEW DAYS AGO. THIS
SHOULD RESULT IN GRADUALLY INCREASING TEMPERATURES AND LITTLE TO NO
CHANCE OF PRECIPITATION ACROSS THE AREA. HIGHS WILL EVENTUALLY CREEP
BACK INTO THE MID 70S BY LATE WEEK/NEXT WEEKEND.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
RESIDUAL MOISTURE WILL ENSURE MID AND HIGH LEVEL CIGS WILL PERSIST
THROUGH AT LEAST SUNDAY EVENING. POSSIBLY DIPPING AS LOW AS 7K-8K FT
AT TIMES...CIGS SHOULD NOT POSE MUCH OF AN AVIATION CONCERN...AND
ORGANIZED SHOWERS SHOULD HOLD OFF UNTIL LATER SUNDAY NIGHT. SFC
WINDS WILL REMAIN VERY LIGHT WITH PROLONGED PERIODS OF VARIABLE
DIRECTION...THOUGH GENERALLY FAVORING SOME EASTERLY COMPONENT
THROUGH SUNDAY AFTERNOON...THEN EVENTUALLY CARRYING SOME WESTERLY
DRIFT BY SUNSET.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
TUESDAY WILL SEE THE FINAL IN A SERIES OF TROUGHS MOVE THROUGH THE
AREA. LOOKS LIKE THE BEST CHANCE OF PRECIPITATION WILL BE IN THE
MOUNTAINS EAST OF PHOENIX. SHOWERS SHOULD TAPER OFF QUICKLY TUESDAY
NIGHT WITH DRY WEATHER FORECAST WEDNESDAY INTO THE WEEKEND. THERE
COULD ALSO BE SOME LOCALIZED BREEZINESS WITH THE TUESDAY SYSTEM
ESPECIALLY DOWN THE COLORADO RIVER AND ACROSS THE RIDGETOPS EAST OF
PHOENIX. NOTHING HIGH ENOUGH TO WARRANT ANY FIRE WEATHER HEADLINES
THOUGH. AS FOR MOISTURE...HUMIDITIES WILL DROP A BIT FROM MID WEEK
ONWARD YET AFTERNOON READINGS WILL ONLY DROP INTO THE 20-30 PERCENT
RANGE WITH GOOD OVERNIGHT RECOVERIES EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...MO
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
915 PM PST SAT JAN 10 2015
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL BRING OCCASIONAL LIGHT RAIN AND HIGH
ELEVATION MOUNTAIN SNOW TONIGHT AND SUNDAY AS IT MOVES ACROSS
SOUTHERN CALIFORNIA. DRY AND COOL ON MONDAY IN NORTHERLY FLOW ALOFT.
WARMER TUESDAY THROUGH THURSDAY WITH GUSTY OFFSHORE WINDS AS SURFACE
HIGH PRESSURE BUILDS OVER THE GREAT BASIN. MILD AND DRY CONDITIONS
WILL CONTINUE INTO NEXT WEEKEND WITH SEASONAL TEMPERATURES.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
9 PM RADAR IMAGERY SHOWED A LARGE BAND OF LIGHT RAIN OVER THE
COASTAL WATERS MOVING NORTHEAST INTO ORANGE AND SAN BERNARDINO
COUNTIES. THE EASTERN EDGE OF THIS RAIN BAND BROUGHT 0.20-0.30" OF
PRECIP TO NORTHWEST ORANGE COUNTY AND THE SAN BERNARDINO MOUNTAINS
TODAY. FARTHER SOUTHEAST MEASURABLE RAIN WAS HARD TO FIND IN
RIVERSIDE AND SAN DIEGO COUNTIES WHERE ONLY A FEW LIGHT
SHOWERS/SPRINKLES WERE REPORTED.
THE MOISTURE INCREASE ACROSS SOCAL THE PAST 24 HOURS HAS BEEN
SIGNIFICANT. THE PRECIPITABLE WATER ON THE 12Z NKX SOUNDING WAS
0.55". THIS EVENING IT JUMPED TO 1.05". THIS WILL SUPPORT CONTINUED
LIGHT PRECIP THROUGH SUNDAY WITH THE RAIN WILL GRADUALLY SHIFTING
EASTWARD TONIGHT WITH THE UPPER TROUGH. LIGHT PRECIPITATION WILL
BECOME MORE WIDESPREAD SUNDAY MORNING WHEN THE SHORTWAVE MOVES
ACROSS SOUTHERN CALIFORNIA. THERE MAY BE EMBEDDED AREAS OF MODERATE
RAIN SUNDAY MORNING WITH THE SHORTWAVE ALOFT AND WEAK LOW LEVEL
CONVERGENCE WITH THE SURFACE TROUGH.
THE HIGH REZ WRF AND HRRR MODELS HAVE NOT HANDLED QPF WITH THIS
SYSTEM VERY WELL. NOT QUITE SURE WHY. THE GLOBAL GFS AND ECMWF ARE
PERFORMING BETTER AND WERE THE PREFERRED MODELS THIS EVENING.
HIGHEST PRECIP AMOUNTS WILL BE OVER THE SAN BERNARDINO MOUNTAINS
WHERE WEAK BUT CONTINUOUS SOUTHERLY FLOW AHEAD OF THE TROUGH WILL
ENHANCE OROGRAPHICS. AN INCH OF RAIN IS POSSIBLE IN THIS AREA BY
SUNDAY EVENING. OROGRAPHICS WILL NOT BE A FACTOR IN THE SAN JACINTO
AND SAN DIEGO COUNTY MOUNTAINS.
ASIDE FROM THE SAN BERNARDINO MOUNTAINS...RAIN TOTALS WILL RANGE
FROM A TENTH TO A HALF INCH...MOST OF IT IN THE FORM OF
STEADY...LIGHT BENEFICIAL SOAKING RAINS. SNOW LEVELS FROM 6500-7000
FEET WILL CONFINE ACCUMULATING SNOW TO THE HIGHER ELEVATIONS OF THE
SAN BERNARDINO AND SAN JACINTO MOUNTAINS. THE PRECIP WILL TAPER OFF
SUNDAY EVENING AND END SUNDAY NIGHT.
MONDAY THROUGH WEDNESDAY...ONSHORE FLOW MONDAY WILL SHIFT OFFSHORE
TUESDAY AND WEDNESDAY AS A STRONG INSIDE SLIDER DIVES SOUTHWARD
ACROSS THE GREAT BASIN AND OVER THE LOWER COLORADO RIVER VALLEY.
GUSTY OFFSHORE WINDS WILL BEGIN ON TUESDAY...WITH PEAK WINDS TUESDAY
NIGHT AND WEDNESDAY WHEN WIND ADVISORIES MAY BE NEEDED. THE
DRY OFFSHORE FLOW WILL CLEAR OUT THE MARINE LAYER WEST OF THE
MOUNTAINS AND ALSO PUSH MAX TEMPS SEVERAL DEGREES ABOVE AVERAGE LATE
NEXT WEEK.
&&
.AVIATION...
100400Z...SCT-BKN CLOUD DECKS IN THE 6000-20000 FT MSL LAYER OVER
AND WEST OF THE MOUNTAINS AND OVER THE HIGH DESERTS THROUGH 11/0900
UTC...WITH EMBEDDED LIGHT SHOWERS/SPRINKLES AND LOCAL VIS 5 SM
POSSIBLE AT TIMES. SHOWERS INCREASING IN COVERAGE AND SLIGHTLY IN
INTENSITY OVER AND WEST OF THE MOUNTAINS AND THE HIGH DESERTS
OVERNIGHT...WITH MULTIPLE BKN-OVC CLOUD LAYERS 3000-15000 FT
MSL...AREAS OF VIS 3-5 SM...LOCALLY AOB 2 SM...AND MOUNTAIN
OBSCURATION ABOVE 3000 FT MSL. LOWER DESERTS WILL EXPERIENCE MOSTLY
UNRESTRICTED VIS...WITH FEW-SCT CLOUDS AOA 10000 FT MSL...BECOMING
SCT-BKN IN THE 6000-15000 FT MSL LAYER AFTER 11/0900 UTC WITH A
POSSIBLE ISOLATED SHOWER AT TIMES PRODUCING VIS DOWN TO 5 SM AND BKN
CIGS DOWN TO 3000 FT MSL. SHOWERS DECREASING BY 11/18Z...TAPERING
OFF THROUGH SUNDAY EVENING.
&&
.MARINE...
800 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY.
&&
.BEACHES...
800 PM...SURFLINE SURF REPORTS STILL INDICATE SURF OF 3-5 FEET
OCCURRING MAINLY SOUTH OF DEL MAR AND NORTH OF NEWPORT BEACH. SURF
WILL DECLINE TONIGHT THROUGH SUNDAY AS THE SWELL DIMINISHES.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MOEDE
AVIATION/MARINE/BEACHES...23
AREA FORECAST DISCUSSION
NWS PUEBLO CO
738 PM MST MON JAN 12 2015
.UPDATE...
ISSUED AT 733 PM MST MON JAN 12 2015
AREAS OF FZFG PRECIP ARE BECOMING MORE SPOTTY AND LIGHT ACROSS
EL PASO COUNTY...AND THIS TREND SHOULD CONTINUE OVERNIGHT.
DENSE FOG LIKELY TO REMAIN AN ISSUE...SO HAVE REPLACED THE
WINTER WEATHER ADVISORY WITH A FREEZING FOG ADVISORY...WHICH
COMBINES THE ELEMENTS OF DENSE FOG AND SPOTTY FREEZING DRIZZLE.
SHOULD SEE THESE AREAS OF DENSE FOG BREAK UP LATER TUESDAY
MORNING. LATEST NAM HAS CUT BACK ON SNOW AMOUNTS FOR THE ERN
MTS TOMORROW...SO WILL HOLD BACK ON ANY HIGHLIGHTS FOR SNOW E OF
THE CONTDVD AND SURROUNDING AREAS. ROSE
UPDATE ISSUED AT 541 PM MST MON JAN 12 2015
UPDATED FOR LATEST OBS AND TRENDS. CUT BACK ON POPS A LITTLE
OVER THE ERN ZONES AS PRECIP SHIFTS TOT HE EAST. HEADLINES
LOOK ON TRACK. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 238 PM MST MON JAN 12 2015
CURRENTLY...DENSE FOG AND FREEZING DRIZZLE CONTINUE ACROSS EL
PASO COUNTY...FORCED BY WEAK E-SE UPSLOPE FLOW AND AIDED BY A
FAIRLY DEEP FRESH SNOW COVER...ESPECIALLY OVER THE EASTERN HALF OF
THE COUNTY. GIVEN LATEST HRRR PROG OF LOW LEVEL E-SE WINDS
CONTINUING THROUGH THE EVENING...WILL EXTEND TIME OF WINTER WX ADV
INTO MID EVENING. NOT EXPECTING MUCH MORE IN THE WAY OF ICE
ACCUMULATION...BUT WITH MOST OBSERVATION SITES STILL REPORTING
FZDZ...WILL HOLD OFF ON CONVERTING TO A DENSE FOG ADVISORY FOR
NOW...THOUGH ONE MAY BEE NEEDED LATER TONIGHT. ELSEWHERE...WEAK
TROUGH WAS PRODUCING SOME LIGHT SNOW OVER THE EASTERN
PLAINS...WHILE MOUNTAINS HAVE SEEN ONLY A FEW FLURRIES AS MUCH OF
THE AREA IS CURRENTLY BETWEEN WAVES.
OVERNIGHT...UPPER LOW WILL DROP SOUTH THROUGH GREAT BASIN...TAKING
A TRACK SLIGHTLY TO THE WEST OF YESTERDAY`S MODEL SOLUTIONS.
EXPECT SNOW TO BREAK OUT THIS EVENING OVER THE SOUTHWEST MOUNTAINS
THEN SPREAD NORTHWARD THROUGH THE LA GARITAS AND SAWATCH RANGE
BY MIDNIGHT. KEPT THE WARNING IN PLACE FOR THE SAN JUANS...AND
CHANGED WATCH TO AN ADVISORY FARTHER NORTH. EASTERN MOUNTAINS WILL
SEE OCCASIONAL FLURRIES THROUGH THE NIGHT...THEN A STEADIER LIGHT
SNOW BEGINS TOWARD MORNING AS UPWARD MOTION GRADUALLY STRENGTHENS.
ONCE BAND OF SNOW ON THE PLAINS EXITS THE AREA THIS
EVENING...SUSPECT LOWER ELEVATIONS WILL SEE ONLY SOME SOME
FLURRIES/FOG/-FZDZ OVERNIGHT...AS SHALLOW UPSLOPE FLOW WILL BE THE
MAIN MECHANISM DRIVING CLOUDS/PRECIP. NAM HINTS AT SOME DRYING
AFTER 06Z AS LOW/MID LEVEL FLOW TAKES ON A VERY SLIGHT SW
COMPONENT...THOUGH DOUBTFUL IT WILL BE ENOUGH TO SCOUR OUT CLOUDS
AND FOG...THOUGH VISIBILITY MIGHT IMPROVE MARGINALLY. GIVEN
AMOUNT OF CLOUD COVER...NUDGED LOW TEMPS UP SLIGHTLY...ESPECIALLY
EASTERN PLAINS.
TUESDAY...UPPER TROUGH CONTINUES TO DROP SOUTH OR SLIGHTLY
SOUTHWEST INTO ARIZONA...WITH TRACK A LITTLE LESS FAVORABLE FOR
HEAVY SNOW OVER THE EASTERN MOUNTAINS AND PLAINS. CONTINENTAL
DIVIDE WILL STILL SEE PERIODS OF MODERATE/HEAVY SNOW THROUGH THE
DAY AS MOIST S-SW FLOW CONTINUES...WITH LIGHTER AND LESS STEADY
SNOW OVER THE REMAINING MOUNTAINS AND WESTERN VALLEYS. EASTERN
MOUNTAINS WILL SEE SOME LIGHT SNOW THROUGH THE DAY...POSSIBLY
BECOMING A LITTLE HEAVIER LATE IN THE AFTERNOON AS SURFACE THROUGH
700 MB FLOW BECOMES MORE UPSLOPE IN RESPONSE TO FALLING PRESSURE
OVER NWRN NM. I-25 CORRIDOR AND PLAINS MAY STAY DRY MUCH OF THE
DAY...WITH SNOW DEVELOPING LATE IN THE AFTERNOON...ESPECIALLY
FROM SOUTH OF PUEBLO TO THE NM BORDER. MAX TEMPS TO GO NOWHERE
ONCE AGAIN WITH CLOUDS AND SNOW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 238 PM MST MON JAN 12 2015
TUESDAY NIGHT AND WEDNESDAY...MODELS ARE IN FAIRLY GOOD AGREEMENT ON
TIMING AND LOCATION OF THE UPPER TROUGH THROUGH WED. TUE NIGHT THE
UPPER LOW DROPS SOUTH NEAR THE 4 CORNERS AND CONTINUES DUE SOUTH
INTO S-SE ARIZONA. WED MORNING THIS UPPER LOW WEAKENS AND SLIDES TO
THE EAST ACROSS SOUTHERN NEW MEXICO. THE EC...GFS AND NAM MODELS ARE
ALL INDICATING THIS PATH...WHICH IS A LITTLE TOO FAR SOUTH FOR ANY
LONG-LASTING SIGNIFICANT SNOWFALL EVENT...IF IT HOLDS TOGETHER.
THEREFORE...FINE TUNED THE POP GRIDS SLIGHTLY TO SHOW WIDESPREAD
AREAL COVERAGE OF PCPN TUE NIGHT BEFORE MIDNIGHT...THEN THE FOCUS OF
THE SNOW WILL SHIFT TO THE SOUTH AS THE LOW PULLS SOUTH AND PCPN
BEGINS TAPERING OFF ACROSS THE NORTH. WED MORNING ISOLATED TO LOW
END SCATTERED POPS ARE FORECAST FOR THE SOUTHERN MTS...THEN PCPN
ENDS AND CLOUDS START TO DIMINISH FROM NORTH TO SOUTH THROUGH THE
AFTERNOON. LOOK FOR A COLD NIGHT TUE WITH LOWS IN THE TEENS TO
SINGLE DIGITS...THEN SLIGHTLY WARMER ON WED AS CONDITIONS BEGIN TO
IMPROVE.
WEDNESDAY NIGHT THROUGH SATURDAY...HIGH PRESSURE OVER THE DESERT SW
WILL HELP TO SHUNT MUCH OF THE ACTIVITY NORTH OF COLORADO...KEEPING
THE FORECAST AREA DRY WITH GRADUAL WARMING. TWO DISTURBANCES WILL
CROSS THE NORTHERN ROCKIES...ONE THU NIGHT AND THE OTHER ON
SAT...BUT AT THIS TIME THEY LOOK TOO FAR NORTH TO AFFECT THE CWA.
LOOK FOR COOL NIGHTS WITH AFTN MAX TEMPS IN THE 40S AND 50S FOR THE
PLAINS...30S TO AROUND 40F FOR THE HIGH VALLEYS.
SUNDAY AND MONDAY...ANOTHER STRONGER DISTURBANCE MOVES INTO THE PAC
NW ON SUNDAY. BOTH THE GFS AND EC STILL PAINT DRY WESTERLY FLOW
ALOFT FOR THE STATE BOTH DAYS...BUT THE EXTENDED PROCEDURE KEEPS
WANTING TO INCLUDE ISOLATED POPS FOR THE CENT MTS
INITIALLY...SPREADING TO ALL OF THE MTS FOR MON. AT THIS TIME...SEE
NO STRONG REASON TO STRAY FAR FROM THE PROCEDURE SINCE A SLIGHT
CHANGE IN COURSE FOR THE WEEKEND DISTURBANCE COULD CERTAINLY BROUGHT
ISOLATED SNOW TO OUR MTS. MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 238 PM MST MON JAN 12 2015
AT KALS...MVFR CIGS ALREADY RETURNING LATE THIS AFTERNOON AND
WILL CONTINUE OVERNIGHT AND THROUGH THE DAY TUESDAY. MAY SEE SOME
FLURRIES AFTER 04Z...THEN A BETTER CHANCE OF SNOW SHOWERS AND
PERIODS OF IFR VISIBILITY 14Z-23Z.
AT KCOS...HAD HOPED SOME LIGHT SNOW WOULD HELP LIFT FOG THIS
AFTERNOON...BUT WITH MAIN AREA OF SNOW NOW WELL EAST OF THE
TERMINAL...EXPECT LIFR CONDITIONS TO PERSIST ALL NIGHT. SOME VERY
LIGHT FZDZ WILL PERSIST THROUGH 02Z-04Z...THOUGH THINK ICE
ACCUMULATIONS WILL BE MINOR. MODEL SOLUTIONS HINT AT SOME DRYING
AND A SUBTLE INCREASE IN VISIBILITY AFTER 06Z-09Z...THOUGH SUSPECT
CONDITIONS WILL STILL STAY LIFR THROUGH THE NIGHT AND INTO THE
MORNING TUES. LIGHT SNOW AND A NORTHEAST WIND WILL DEVELOP TUES
AFTER 16Z-18Z...WHICH SHOULD IMPROVE VIS/CIGS INTO THE IFR
CATEGORY BY MID AFTERNOON.
AT KPUB...AFTER SOME BRIEF MVFR CIGS THIS AFTERNOON...EXPECT CIGS
TO DROP BACK BELOW BKN010 AFTER 00Z...WITH SOME MVFR VIS IN FOG
AND FLURRIES THROUGH THE NIGHT. ON TUE...MVFR CIGS WILL CONTINUE
THROUGH THE DAY...WITH PERIODS OF IFR CIGS/VIS BECOMING MORE
LIKELY IN THE AFTERNOON AS LIGHT SNOW DEVELOPS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 8 AM MST TUESDAY FOR COZ084-085.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 11 PM MST
TUESDAY FOR COZ058-060-061-064-066.
WINTER STORM WARNING UNTIL 5 PM MST TUESDAY FOR COZ068.
&&
$$
UPDATE...ROSE
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
553 PM MST MON JAN 12 2015
.UPDATE...
ISSUED AT 541 PM MST MON JAN 12 2015
UPDATED FOR LATEST OBS AND TRENDS. CUT BACK ON POPS A LITTLE
OVER THE ERN ZONES AS PRECIP SHIFTS TOT HE EAST. HEADLINES
LOOK ON TRACK. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 238 PM MST MON JAN 12 2015
CURRENTLY...DENSE FOG AND FREEZING DRIZZLE CONTINUE ACROSS EL
PASO COUNTY...FORCED BY WEAK E-SE UPSLOPE FLOW AND AIDED BY A
FAIRLY DEEP FRESH SNOW COVER...ESPECIALLY OVER THE EASTERN HALF OF
THE COUNTY. GIVEN LATEST HRRR PROG OF LOW LEVEL E-SE WINDS
CONTINUING THROUGH THE EVENING...WILL EXTEND TIME OF WINTER WX ADV
INTO MID EVENING. NOT EXPECTING MUCH MORE IN THE WAY OF ICE
ACCUMULATION...BUT WITH MOST OBSERVATION SITES STILL REPORTING
FZDZ...WILL HOLD OFF ON CONVERTING TO A DENSE FOG ADVISORY FOR
NOW...THOUGH ONE MAY BEE NEEDED LATER TONIGHT. ELSEWHERE...WEAK
TROUGH WAS PRODUCING SOME LIGHT SNOW OVER THE EASTERN
PLAINS...WHILE MOUNTAINS HAVE SEEN ONLY A FEW FLURRIES AS MUCH OF
THE AREA IS CURRENTLY BETWEEN WAVES.
OVERNIGHT...UPPER LOW WILL DROP SOUTH THROUGH GREAT BASIN...TAKING
A TRACK SLIGHTLY TO THE WEST OF YESTERDAY`S MODEL SOLUTIONS.
EXPECT SNOW TO BREAK OUT THIS EVENING OVER THE SOUTHWEST MOUNTAINS
THEN SPREAD NORTHWARD THROUGH THE LA GARITAS AND SAWATCH RANGE
BY MIDNIGHT. KEPT THE WARNING IN PLACE FOR THE SAN JUANS...AND
CHANGED WATCH TO AN ADVISORY FARTHER NORTH. EASTERN MOUNTAINS WILL
SEE OCCASIONAL FLURRIES THROUGH THE NIGHT...THEN A STEADIER LIGHT
SNOW BEGINS TOWARD MORNING AS UPWARD MOTION GRADUALLY STRENGTHENS.
ONCE BAND OF SNOW ON THE PLAINS EXITS THE AREA THIS
EVENING...SUSPECT LOWER ELEVATIONS WILL SEE ONLY SOME SOME
FLURRIES/FOG/-FZDZ OVERNIGHT...AS SHALLOW UPSLOPE FLOW WILL BE THE
MAIN MECHANISM DRIVING CLOUDS/PRECIP. NAM HINTS AT SOME DRYING
AFTER 06Z AS LOW/MID LEVEL FLOW TAKES ON A VERY SLIGHT SW
COMPONENT...THOUGH DOUBTFUL IT WILL BE ENOUGH TO SCOUR OUT CLOUDS
AND FOG...THOUGH VISIBILITY MIGHT IMPROVE MARGINALLY. GIVEN
AMOUNT OF CLOUD COVER...NUDGED LOW TEMPS UP SLIGHTLY...ESPECIALLY
EASTERN PLAINS.
TUESDAY...UPPER TROUGH CONTINUES TO DROP SOUTH OR SLIGHTLY
SOUTHWEST INTO ARIZONA...WITH TRACK A LITTLE LESS FAVORABLE FOR
HEAVY SNOW OVER THE EASTERN MOUNTAINS AND PLAINS. CONTINENTAL
DIVIDE WILL STILL SEE PERIODS OF MODERATE/HEAVY SNOW THROUGH THE
DAY AS MOIST S-SW FLOW CONTINUES...WITH LIGHTER AND LESS STEADY
SNOW OVER THE REMAINING MOUNTAINS AND WESTERN VALLEYS. EASTERN
MOUNTAINS WILL SEE SOME LIGHT SNOW THROUGH THE DAY...POSSIBLY
BECOMING A LITTLE HEAVIER LATE IN THE AFTERNOON AS SURFACE THROUGH
700 MB FLOW BECOMES MORE UPSLOPE IN RESPONSE TO FALLING PRESSURE
OVER NWRN NM. I-25 CORRIDOR AND PLAINS MAY STAY DRY MUCH OF THE
DAY...WITH SNOW DEVELOPING LATE IN THE AFTERNOON...ESPECIALLY
FROM SOUTH OF PUEBLO TO THE NM BORDER. MAX TEMPS TO GO NOWHERE
ONCE AGAIN WITH CLOUDS AND SNOW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 238 PM MST MON JAN 12 2015
TUESDAY NIGHT AND WEDNESDAY...MODELS ARE IN FAIRLY GOOD AGREEMENT ON
TIMING AND LOCATION OF THE UPPER TROUGH THROUGH WED. TUE NIGHT THE
UPPER LOW DROPS SOUTH NEAR THE 4 CORNERS AND CONTINUES DUE SOUTH
INTO S-SE ARIZONA. WED MORNING THIS UPPER LOW WEAKENS AND SLIDES TO
THE EAST ACROSS SOUTHERN NEW MEXICO. THE EC...GFS AND NAM MODELS ARE
ALL INDICATING THIS PATH...WHICH IS A LITTLE TOO FAR SOUTH FOR ANY
LONG-LASTING SIGNIFICANT SNOWFALL EVENT...IF IT HOLDS TOGETHER.
THEREFORE...FINE TUNED THE POP GRIDS SLIGHTLY TO SHOW WIDESPREAD
AREAL COVERAGE OF PCPN TUE NIGHT BEFORE MIDNIGHT...THEN THE FOCUS OF
THE SNOW WILL SHIFT TO THE SOUTH AS THE LOW PULLS SOUTH AND PCPN
BEGINS TAPERING OFF ACROSS THE NORTH. WED MORNING ISOLATED TO LOW
END SCATTERED POPS ARE FORECAST FOR THE SOUTHERN MTS...THEN PCPN
ENDS AND CLOUDS START TO DIMINISH FROM NORTH TO SOUTH THROUGH THE
AFTERNOON. LOOK FOR A COLD NIGHT TUE WITH LOWS IN THE TEENS TO
SINGLE DIGITS...THEN SLIGHTLY WARMER ON WED AS CONDITIONS BEGIN TO
IMPROVE.
WEDNESDAY NIGHT THROUGH SATURDAY...HIGH PRESSURE OVER THE DESERT SW
WILL HELP TO SHUNT MUCH OF THE ACTIVITY NORTH OF COLORADO...KEEPING
THE FORECAST AREA DRY WITH GRADUAL WARMING. TWO DISTURBANCES WILL
CROSS THE NORTHERN ROCKIES...ONE THU NIGHT AND THE OTHER ON
SAT...BUT AT THIS TIME THEY LOOK TOO FAR NORTH TO AFFECT THE CWA.
LOOK FOR COOL NIGHTS WITH AFTN MAX TEMPS IN THE 40S AND 50S FOR THE
PLAINS...30S TO AROUND 40F FOR THE HIGH VALLEYS.
SUNDAY AND MONDAY...ANOTHER STRONGER DISTURBANCE MOVES INTO THE PAC
NW ON SUNDAY. BOTH THE GFS AND EC STILL PAINT DRY WESTERLY FLOW
ALOFT FOR THE STATE BOTH DAYS...BUT THE EXTENDED PROCEDURE KEEPS
WANTING TO INCLUDE ISOLATED POPS FOR THE CENT MTS
INITIALLY...SPREADING TO ALL OF THE MTS FOR MON. AT THIS TIME...SEE
NO STRONG REASON TO STRAY FAR FROM THE PROCEDURE SINCE A SLIGHT
CHANGE IN COURSE FOR THE WEEKEND DISTURBANCE COULD CERTAINLY BROUGHT
ISOLATED SNOW TO OUR MTS. MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 238 PM MST MON JAN 12 2015
AT KALS...MVFR CIGS ALREADY RETURNING LATE THIS AFTERNOON AND
WILL CONTINUE OVERNIGHT AND THROUGH THE DAY TUESDAY. MAY SEE SOME
FLURRIES AFTER 04Z...THEN A BETTER CHANCE OF SNOW SHOWERS AND
PERIODS OF IFR VISIBILITY 14Z-23Z.
AT KCOS...HAD HOPED SOME LIGHT SNOW WOULD HELP LIFT FOG THIS
AFTERNOON...BUT WITH MAIN AREA OF SNOW NOW WELL EAST OF THE
TERMINAL...EXPECT LIFR CONDITIONS TO PERSIST ALL NIGHT. SOME VERY
LIGHT FZDZ WILL PERSIST THROUGH 02Z-04Z...THOUGH THINK ICE
ACCUMULATIONS WILL BE MINOR. MODEL SOLUTIONS HINT AT SOME DRYING
AND A SUBTLE INCREASE IN VISIBILITY AFTER 06Z-09Z...THOUGH SUSPECT
CONDITIONS WILL STILL STAY LIFR THROUGH THE NIGHT AND INTO THE
MORNING TUES. LIGHT SNOW AND A NORTHEAST WIND WILL DEVELOP TUES
AFTER 16Z-18Z...WHICH SHOULD IMPROVE VIS/CIGS INTO THE IFR
CATEGORY BY MID AFTERNOON.
AT KPUB...AFTER SOME BRIEF MVFR CIGS THIS AFTERNOON...EXPECT CIGS
TO DROP BACK BELOW BKN010 AFTER 00Z...WITH SOME MVFR VIS IN FOG
AND FLURRIES THROUGH THE NIGHT. ON TUE...MVFR CIGS WILL CONTINUE
THROUGH THE DAY...WITH PERIODS OF IFR CIGS/VIS BECOMING MORE
LIKELY IN THE AFTERNOON AS LIGHT SNOW DEVELOPS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 8 PM MST THIS EVENING FOR COZ084-
085.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 11 PM MST
TUESDAY FOR COZ058-060-061-064-066.
WINTER STORM WARNING UNTIL 5 PM MST TUESDAY FOR COZ068.
&&
$$
UPDATE...ROSE
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1132 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1121 AM MST SUN JAN 11 2015
UPDATED THE FORECAST BASED ON THE LATEST HIGH RESOLUTION MODEL
DATA FOR THIS AFTERNOON AND TONIGHT. RADAR AND SATELLITE INDICATE
THE FRONTAL BOUNDARY HAS PUSHED THROUGH THE PALMER DIVIDE WITH
INCREASED CLOUDS AND LIGHT RADAR RETURNS. NOT SEEING ANY REPORTS
FROM OBSERVATIONS OF PRECIPITATION REACHING THE GROUND YET AS DEW
POINT DEPRESSIONS ARE STILL HIGH. EXPECT THE FRONT TO CONTINUE
SOUTH THIS AFTERNOON...WITH CLOUD COVER FILLING IN BY THIS EVENING
ALONG ALL OF THE I-25 CORRIDOR. MODELS HAVE SNOW BY 6 PM OVER EL
PASO COUNTY...AND QUICKLY SATURATING SOUTH TO PUEBLO THROUGH THE
EVENING. BASED ON THE LATEST DATA...INCREASED SNOWFALL TOTALS FOR
THIS EVENING WITH 1 TO 3 INCHES OF EL PASO COUNTY AND AROUND HALF
AN INCH IN PUEBLO. THERE IS THE POSSIBILITY THAT SNOW COULD BE
HEAVIER AT TIMES...ESPECIALLY FOR A SHORT PERIOD FROM 8 PM THROUGH
AROUND MIDNIGHT...AND LOCALLY HIGHER AMOUNTS ARE POSSIBLE. MOZLEY
UPDATE ISSUED AT 903 AM MST SUN JAN 11 2015
UPDATED TO EXPIRE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY.
OBSERVATIONS INDICATE A FEW AREAS OF FOG STILL PERSIST AND WILL
CONTINUE TO PRODUCE REDUCED VISIBILITIES THROUGH NOON. MOZLEY
UPDATE ISSUED AT 724 AM MST SUN JAN 11 2015
MADE ADJUSTMENTS TO PRIMARILY NEAR-TERM GRIDS AS WELL AS SOME OF
THE SHORT-TERM GRIDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1029 AM MST SUN JAN 11 2015
KALS...LOW STRATUS WILL PERSIST ACROSS THE SAN LUIS VALLEY THROUGH
MONDAY MORNING. EXPECT FOG TO REDEVELOP THIS EVENING WITH IFR TO
LIFR CONDITIONS DUE TO LOWERED CIGS AND VIS. SNOW SHOWERS OVER THE
MOUNTAINS COULD MOVE INTO THE VALLEY AND MAY BRIEFLY IMPACT THE
TERMINAL TONIGHT.
KCOS...A COLD FRONT IS CURRENTLY DROPPING SOUTH OVER THE PALMER
DIVIDE WITH LOW STRATUS AND SNOW EXPECTED TO DEVELOP OVER THE
TERMINAL THROUGH THIS AFTERNOON. MODEL GUIDANCE SUGGESTS SNOW WILL
BE HEAVIEST BETWEEN 03-08Z TONIGHT WITH A COUPLE OF INCHES OF SNOW
POSSIBLE ON THE RUNWAYS. LIGHT SNOW WILL CONTINUE INTO MONDAY
MORNING.
KPUB...VFR CONDITIONS THROUGH MID AFTERNOON WITH A COLD FRONT
DROPPING SOUTH ACROSS THE TERMINAL LATER THIS AFTERNOON. STRATUS
WILL FILL IN BEHIND THE COLD FRONT. INITIALLY RAIN...CHANGING TO
SNOW IS FORECAST THIS EVENING WITH SNOW PERSISTING OVERNIGHT.
MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1034 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 903 AM MST SUN JAN 11 2015
UPDATED TO EXPIRE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY.
OBSERVATIONS INDICATE A FEW AREAS OF FOG STILL PERSIST AND WILL
CONTINUE TO PRODUCE REDUCED VISIBILITIES THROUGH NOON. MOZLEY
UPDATE ISSUED AT 724 AM MST SUN JAN 11 2015
MADE ADJUSTMENTS TO PRIMARILY NEAR-TERM GRIDS AS WELL AS SOME OF
THE SHORT-TERM GRIDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1029 AM MST SUN JAN 11 2015
KALS...LOW STRATUS WILL PERSIST ACROSS THE SAN LUIS VALLEY THROUGH
MONDAY MORNING. EXPECT FOG TO REDEVELOP THIS EVENING WITH IFR TO
LIFR CONDITIONS DUE TO LOWERED CIGS AND VIS. SNOW SHOWERS OVER THE
MOUNTAINS COULD MOVE INTO THE VALLEY AND MAY BRIEFLY IMPACT THE
TERMINAL TONIGHT.
KCOS...A COLD FRONT IS CURRENTLY DROPPING SOUTH OVER THE PALMER
DIVIDE WITH LOW STRATUS AND SNOW EXPECTED TO DEVELOP OVER THE
TERMINAL THROUGH THIS AFTERNOON. MODEL GUIDANCE SUGGESTS SNOW WILL
BE HEAVIEST BETWEEN 03-08Z TONIGHT WITH A COUPLE OF INCHES OF SNOW
POSSIBLE ON THE RUNWAYS. LIGHT SNOW WILL CONTINUE INTO MONDAY
MORNING.
KPUB...VFR CONDITIONS THROUGH MID AFTERNOON WITH A COLD FRONT
DROPPING SOUTH ACROSS THE TERMINAL LATER THIS AFTERNOON. STRATUS
WILL FILL IN BEHIND THE COLD FRONT. INITIALLY RAIN...CHANGING TO
SNOW IS FORECAST THIS EVENING WITH SNOW PERSISTING OVERNIGHT.
MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS PUEBLO CO
912 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 903 AM MST SUN JAN 11 2015
UPDATED TO EXPIRE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY.
OBSERVATIONS INDICATE A FEW AREAS OF FOG STILL PERSIST AND WILL
CONTINUE TO PRODUCE REDUCED VISIBILITIES THROUGH NOON. MOZLEY
UPDATE ISSUED AT 724 AM MST SUN JAN 11 2015
MADE ADJUSTMENTS TO PRIMARILY NEAR-TERM GRIDS AS WELL AS SOME OF
THE SHORT-TERM GRIDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 355 AM MST SUN JAN 11 2015
FOR KALS...LOW CLOUDS AND AREAS OF DENSE FOG ARE EXPECTED INTO MID-
MORNING WITH CONDITIONS THEN IMPROVING BEFORE ANOTHER ROUND OF LOW
CLOUDS AND FOG DEVELOP AGAIN TONIGHT.
FOR KCOS AND KPUB...OTHER THAN SOME LOCALIZED LOW CLOUDS AND FOG
EARLY THIS MORNING...VFR CONDITIONS ARE ANTICIPATED TODAY BEFORE
CONDITIONS DETERIORATE BY TONIGHT IN THE WAKE OF A COLD FRONT MOVING
ACROSS SOUTHEASTERN COLORADO TODAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AREA FORECAST DISCUSSION
NWS PUEBLO CO
724 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 724 AM MST SUN JAN 11 2015
MADE ADJUSTMENTS TO PRIMARILY NEAR-TERM GRIDS AS WELL AS SOME OF
THE SHORT-TERM GRIDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 355 AM MST SUN JAN 11 2015
FOR KALS...LOW CLOUDS AND AREAS OF DENSE FOG ARE EXPECTED INTO MID-
MORNING WITH CONDITIONS THEN IMPROVING BEFORE ANOTHER ROUND OF LOW
CLOUDS AND FOG DEVELOP AGAIN TONIGHT.
FOR KCOS AND KPUB...OTHER THAN SOME LOCALIZED LOW CLOUDS AND FOG
EARLY THIS MORNING...VFR CONDITIONS ARE ANTICIPATED TODAY BEFORE
CONDITIONS DETERIORATE BY TONIGHT IN THE WAKE OF A COLD FRONT MOVING
ACROSS SOUTHEASTERN COLORADO TODAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM MST THIS MORNING FOR COZ069>071.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
442 AM MST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 355 AM MST SUN JAN 11 2015
FOR KALS...LOW CLOUDS AND AREAS OF DENSE FOG ARE EXPECTED INTO MID-
MORNING WITH CONDITIONS THEN IMPROVING BEFORE ANOTHER ROUND OF LOW
CLOUDS AND FOG DEVELOP AGAIN TONIGHT.
FOR KCOS AND KPUB...OTHER THAN SOME LOCALIZED LOW CLOUDS AND FOG
EARLY THIS MORNING...VFR CONDITIONS ARE ANTICIPATED TODAY BEFORE
CONDITIONS DETERIORATE BY TONIGHT IN THE WAKE OF A COLD FRONT MOVING
ACROSS SOUTHEASTERN COLORADO TODAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM MST THIS MORNING FOR COZ069>071.
&&
$$
SHORT TERM...77
LONG TERM...28
AVIATION...77
AREA FORECAST DISCUSSION
NWS TAUNTON MA
654 PM EST MON JAN 12 2015
.SYNOPSIS...
AN ARCTIC FRONT MOVES ACROSS THE REGION LATER TONIGHT WITH MUCH
COLDER WEATHER TUESDAY...TUESDAY NIGHT INTO WEDNESDAY. THE ARCTIC
AIR WILL LIKELY RESULT IN SCATTERED SNOW SHOWERS ACROSS CAPE COD AND
PLYMOUTH COUNTY TUE AND WED WITH MINOR ACCUMULATIONS POSSIBLE. LOW
PRESSURE PASSES SOUTH THURSDAY...THEN A COLD FRONT WILL DROP
SOUTH ACROSS THE REGION FRIDAY FOLLOWED BY HIGH PRES SATURDAY. A
COLD FRONT MOVES ACROSS THE REGION SUNDAY OR SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
645 PM UPDATE...
BACK EDGE OF STEADIER RAINFALL ALONG AND SOUTH OF THE SOUTH
COAST...BUT STILL PATCHY LIGHT RAIN EXTENDING BACK TO THE I95
CORRIDOR. MODELS HAVE BEEN TOO SLOW WITH RAIN EXITING THE REGION
ALTHOUGH THE HRRR IS STARTING TO CATCH UP. WE EXPECT RAIN ENDING
02-06Z ACROSS SE NEW ENG WITH ACK THE LAST TO DRY OUT.
COOLING ALOFT DOES NOT OCCUR TIL AFT 06Z IN SE NEW ENG WHILE
LOWER LEVELS ARE COOLING FASTER SO THERE IS A LOW PROB THE PRECIP
COULD END AS MIX OF RAIN/SLEET BUT IT IS MORE LIKELY PRECIP EXITS
BEFORE COLDER AIR ARRIVES.
TEMPS IN THE INTERIOR ARE HOVERING AROUND FREEZING AND THERE IS
CONCERN FOR AREAS OF BLACK ICE DEVELOPING WHICH MAY REACH THE I95
CORRIDOR BY MIDNIGHT AS TEMPS FALL TO FREEZING. SUB FREEZING
TEMPS ARRIVE NEAR THE SOUTH COAST AFTER MIDNIGHT BUT THE GUSTY NW
WINDS SHOULD ALLOW FOR ENOUGH DRYING TO PRECLUDE BLACK ICE HERE.
FURTHER NW...SOME LIGHT SNOW AHEAD OF THE ARCTIC FRONT WILL AFFECT
PORTIONS OF NW MA THIS EVENING. ARCTIC FRONT AND POST FRONTAL
AIRMASS INVADES THE AREA 06Z-12Z WITH TEMPS FALLING QUICKLY INTO
THE TEENS AND 20S BY SUNRISE. GUSTY NNE WINDS ACCOMPANY THE
FRONTAL PASSAGE AND WILL PROVIDE WIND CHILLS FROM -5 TO +5 ACROSS
MUCH OF THE REGION BY DAYBREAK!
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TUESDAY...
1045 MB ARCTIC HIGH OVER THE GREAT LAKES ADVECTS INTO NORTHERN NEW
ENGLAND. THIS IS A CLASSIC SETUP FOR A SHALLOW ARCTIC AIRMASS TO
SETTLE ACROSS SOUTHERN NEW ENGLAND WITH 925 MB TEMPS COLDER THAN 850
MB. THUS ANOMALOUS COLD DAY TOMORROW WITH TEMPS AROUND 15 DEGS
COLDER THAN NORMAL WITH HIGHS ONLY IN THE TEENS INLAND TO THE 20S
ALONG THE COAST! IN ADDITION A GUSTY NNE WIND WILL PROVIDE BITTER
COLD WIND CHILLS.
GIVEN THIS SHALLOW COLD AIRMASS USED THE COLDER 2 METER TEMPS AS MOS
TEMPS WERE TOO WARM.
MOST OF THE REGION WILL BE DRY TOMORROW WITH THE EXCEPTION OF CAPE
COD/NANTUCKET AND PLYMOUTH COUNTY AS THE TRAJECTORY OF THE COLD AIR
ON NNE FLOW GENERATES OCEAN EFFECT SNOW SHOWERS. NAM BUFKIT AT CHH
OFFERED UP TO 300J OF OCEAN INDUCED CAPE AND AN EQUILIBRIUM LEVEL
AROUND 5 FT. THIS COMBINED WITH CYCLONIC FLOW AT H8 AND H7 SHOULD BE
SUFFICIENT FOR NUMEROUS SNOW BANDS OFF THE OCEAN INTO PLYMOUTH AND
CAPE COD...POSSIBLY ACK AND MVY TOO. ALL MODEL GUIDANCE OFFERING AT
LEAST SOME QPF AND MODELS TYPICALLY ARE TOO CONSERVATIVE WITH QPF IN
THESE EVENTS. GIVEN LOW LEVEL LAPSE RATES PEAK AT 18C /-12C TOP OF
BLYR AND SST +6C/ THINKING POTENTIAL FOR AT LEAST AN INCH OF SNOW.
TUE NIGHT...
OCEAN EFFECT SNOW SHOWERS CONTINUE BUT LIKELY NOT AS ROBUST AS MID
LEVEL FLOW BECOMES MORE ANTICYCLONIC ALONG WITH SUBSIDENCE INVERSION
LOWERING AND LIMITING SHALLOW UPDRAFT POTENTIAL. LOW LEVEL LAPSE
RATES EASE AS WELL. THEREFORE SNOW BANDS LIKELY NOT AS ROBUST AS TUE
AFTN.
VERY COLD NIGHT WITH ARCTIC AIRMASS AND RADIATIONAL COOLING
CONDITIONS. SIDED WITH THE COLDER MOS GUID WHICH YIELDS MOST
LOCATIONS OUTSIDE THE URBAN AREAS TO DIP INTO THE SINGLE DIGITS WITH
-2F TO -8F CT RVR VLY /I-91 CORRIDOR/ OF MA.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
* OCEAN-EFFECT FLURRIES FOR CAPE COD LINGER INTO WEDNESDAY
* DRY WEATHER AND BELOW NORMAL TEMPS INTO SATURDAY...THEN A BRIEF
WARMUP POSSIBLE SUNDAY
OVERVIEW...
+NAO PATTERN WITH LACK OF DOWNSTREAM BLOCKING WILL CONTINUE TO
DOMINATE THE PATTERN THROUGH THE EXTENDED PERIOD RESULTING IN
PROGRESSIVE PATTERN AND LACK OF ANY STORMS. TEMPS WILL AVERAGE BELOW
NORMAL FOR MUCH OF THE PERIOD AS WESTERN US RIDGING AND POLAR VORTEX
ACROSS HUDSON BAY WILL RESULT IN BROAD TROF ACROSS GT LAKES AND
NORTHEAST WITH OCCASIONAL NORTHERN STREAM SHORTWAVES REINFORCING
COLDER AIR.
WEDNESDAY INTO THURSDAY...
HIGH PRES IN CONTROL WILL BRING DRY WEATHER AND BELOW NORMAL TEMPS
AS SHALLOW ARCTIC AIR OOZES SOUTH INTO THE REGION. HOWEVER...CLOUDS
AND OCEAN EFFECT FLURRIES WILL LIKELY LINGER ACROSS PORTIONS OF SE
COASTAL MA AND CAPE COD INTO WEDNESDAY AS NE FLOW COMBINES WITH
STEEP LOW LEVEL LAPSE RATES OVER THE OCEAN. PRECIP WILL LIKELY BE
JUST FLURRIES AS SUBSIDENCE INVERSION LOWERS WITH MIXED LAYER
BECOMING SHALLOW. TEMPS MOSTLY IN THE 20S WED WITH SLIGHT MODERATION
THU.
FRIDAY...
SOME UNCERTAINTY WITH TIMING OF A COLD FRONT DROPPING
SOUTH FROM CANADA. GFS IS FASTER AND MORE AGGRESSIVE THAN ECMWF
PUSHING FRONT TO THE SOUTH. FOLLOWED A BLEND OF THE GUIDANCE WHICH
TEMPERS MORE AGGRESSIVE GFS. STILL MAINLY DRY AS MOISTURE IS
LIMITED...SO JUST A LOW PROB FOR A FEW FLURRIES.
SATURDAY THROUGH MONDAY...
TIMING OF FEATURES IS UNCERTAIN AT THIS TIME RANGE IN PROGRESSIVE
PATTERN BUT IT LOOKS LIKE HIGH PRES WILL BRING DRY AND SEASONABLY
COLD CONDITIONS SATURDAY...THEN A BRIEF WARMUP FOLLOWED BY A COLD
FROPA SOME TIME SUNDAY OR SUNDAY NIGHT WHICH MAY BRING A FEW
SHOWERS. COOLER AND DRIER WEATHER FOLLOWS MONDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...RAIN EXITS SE NEW ENG 02-06Z WITH ACK LAST TO DRY OUT.
LOW PROB PRECIP ENDS AS A MIX OF RAIN/SLEET. AREAS OF IFR IMPROVE
TO VFR 02-06Z BUT MVFR CIGS MAY LINGER ACROSS CAPE/ISLANDS
OVERNIGHT. N WIND GUSTS INCREASING TO 20-25 KT AFT MIDNIGHT.
TUE/TUE NIGHT...MVFR SOUTHEAST MA ALONG WITH OCEAN EFFECT SNOW
SHOWERS. MINOR ACCUMULATIONS POSSIBLE. MVFR MAY BLEED INTO RI AND
EASTERN MA. OTHERWISE VFR ELSEWHERE. NNE WINDS 25-30 KT OVER CAPE
COD AND THE ISLANDS DIMINISHING TO 15 KT TUE NIGHT. LIGHTER WINDS
ELSEWHERE.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE IN
EXACT TIMING.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE IN
EXACT TIMING.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...MODERATE CONFIDENCE.
WEDNESDAY AND THURSDAY...HIGH CONFIDENCE. MAINLY VFR...EXCEPT AREAS
OF MVFR CIGS ACROSS E MA AND ESPECIALLY CAPE COD. SCT FLURRIES
POSSIBLE SE MA AND CAPE COD...MAINLY DURING WED.
FRIDAY AND SATURDAY...MODERATE CONFIDENCE. VFR
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...ARCTIC FRONT SWEEPS ACROSS THE WATERS 03Z-09Z FROM NORTH
TO SOUTH. NNE WINDS GUSTS UP TO 30 KT TOWARD MORNING. LIGHT FREEZING
SPRAY POSSIBLE TOWARD MORNING.
TUESDAY...GUSTY NNE WINDS UP TO 30 KT WITH ARCTIC HIGH MOVING INTO
NORTHERN NEW ENGLAND. ROUGH SEAS 10-15 FT EAST OF CAPE COD. SNOW
SHOWERS OVER EASTERN MA WATERS INCLUDING CAPE COD BAY AND NANTUCKET
SOUND WILL LIMIT VSBY. LIGHT FREEZING SPRAY LIKELY NEAR SHORE.
TUE NIGHT...WINDS DIMINISH AS HIGH PRES MOVES OVERHEAD. SEAS
SUBSIDED AS WELL ALONG WITH RISK OF FREEZING SPRAY DIMINISHING.
OCEAN EFFECT SNOW SHOWERS LINGER ESPECIALLY DURING THE EVENING.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...MODERATE CONFIDENCE.
WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE. HIGH PRESSURE TO THE N
WILL RESULT IN LIGHT NE WINDS AND SEAS BELOW SCA. OCEAN EFFECT SNOW
SHOWERS POSSIBLE ACROSS WATERS N AND E OF CAPE COD WEDNESDAY.
FRIDAY...MODERATE CONFIDENCE. MAY SEE A PERIOD OF GUSTY NW WINDS
DEVELOPING WHICH MAY REACH SCA THRESHOLDS.
SATURDAY...MODERATE CONFIDENCE. LIGHT WINDS AND SEAS BELOW SCA.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR
ANZ231>235-237-250-251-254>256.
SMALL CRAFT ADVISORY FROM 1 AM TO 1 PM EST TUESDAY FOR ANZ230-
236.
&&
$$
SYNOPSIS...KJC/NOCERA
NEAR TERM...KJC/NOCERA
SHORT TERM...NOCERA
LONG TERM...KJC
AVIATION...KJC/NOCERA
MARINE...KJC/NOCERA
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
445 AM EST SUN JAN 11 2015
.SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
INVERTED COASTAL TROUGH IS FINALLY NEARING THE COAST WITH LIGHT RAIN
SHOWERS MOVING ONSHORE ROUGHLY NORTH OF MAYPORT EARLY THIS MORNING.
COMPLICATED SCENARIO IS MAKING FOR A LOW CONFIDENCE FORECAST TODAY
BUT THE THINKING IS THAT SHOWER ACTIVITY WILL CONTINUE TO INCREASE
THIS MORNING AS AN UPPER LEVEL DISTURBANCE (CURRENTLY OVER THE
NORTHEAST GULF OF MEXICO) MOVES NORTHEAST ACROSS OUR REGION. THIS
WILL PROVIDE UPPER SUPPORT THAT SHOULD LEND A HELPING HAND TO LIFT
ALREADY PRESENT ALONG THE COASTAL TROUGH AT THE SURFACE.
PRECIP TIMING WILL BE A CHALLENGE TODAY BUT THE GENERAL EXPECTATION
IS FOR SCATTERED TO NUMEROUS SHOWERS ALONG THE COAST WITH MUCH
LESSER CHANCES FARTHER INLAND. WE SHOULD SEE A DECREASING TREND IN
RAIN CHANCES LATER THIS AFTERNOON INTO THIS EVENING IN THE WAKE OF
THE FIRST UPPER DISTURBANCE. TEMPERATURES WILL BE CHALLENGING TODAY
AND WE HAVE FAVORED A MODEL BLEND WHICH RESULTS IN A WIDE RANGE OF
MAX TEMPS...LOW 50S NORTH TO MID 70S SOUTH. MOSTLY CLOUDY SKIES ARE
EXPECTED TO PERSIST THROUGH THE DAY.
THERE SHOULD BE A LULL IN PRECIP THIS EVENING BEFORE A STRONGER
UPPER LEVEL DISTURBANCE LIFTS NORTHEAST OUT OF THE GULF OF MEXICO
AND MOVES INTO OUR REGION AFTER MIDNIGHT TONIGHT. THIS WILL BRING
A SIGNIFICANT INCREASE IN RAIN CHANCES LATE TONIGHT(EARLY MONDAY
MORNING) WITH EVEN A FEW THUNDERSTORMS EXPECTED DUE TO INCREASING
ELEVATED INSTABILITY. CLOUD COVER AND WARM MOIST SOUTHERLY FLOW
WILL RESULT IN A MILD NIGHT WITH TEMPS IN THE 50S AND 60S FOR MOST
AREAS.
SHORTWAVE ENERGY WILL MOVE NORTHEASTWARD THROUGH OUR REGION ON
MONDAY...PROMPTING A WARM FRONT TO LIFT NORTHWARD FROM THE FL
PENINSULA. THIS WILL INDUCE STRONG ISENTROPIC LIFT...AND A COUPLE OF
WAVES OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL STREAM ACROSS OUR
AREA FROM THE GULF OF MEXICO. ONE BATCH WILL MOVE ONSHORE INTO THE
SUWANNEE VALLEY AND SOUTHEAST GA DURING THE EARLY MORNING
HOURS...WITH ANOTHER SHOT OF MOSTLY ELEVATED CONVECTION POSSIBLE
DURING THE AFTERNOON HOURS. RAINFALL AMOUNTS WILL AVERAGE AROUND A
HALF INCH. THE WARM FRONT SHOULD LIFT NORTHWARD INTO INTERIOR
SOUTHEAST GA BY LATE MONDAY AFTERNOON...AND DECREASING COVERAGE OF
RAINFALL FROM SOUTHWEST TO NORTHEAST SHOULD ALLOW HIGHS TO CLIMB
WELL INTO THE 70S FOR NORTHEAST FL...WITH 60S EXPECTED FOR INTERIOR
SOUTHEAST GA. FORCING ALOFT WILL DECREASE MONDAY NIGHT AS SHORTWAVE
ENERGY DEPARTS. UNSEASONABLY WARM AND MOIST CONDITIONS WILL PREVAIL
AS A COLD FRONT ONLY SLOWLY APPROACHES FROM THE NORTHWEST. FOG
FORMATION SEEMS LIKELY...BUT DUE TO UNCERTAINTY IN CLOUD
COVER...KEPT ONLY PATCHY COVERAGE IN THE FORECAST GRIDS FOR NOW.
LOWS WILL RANGE FROM 55-60.
SOUTHWEST FLOW ALOFT WILL PREVAIL ON TUESDAY IN ADVANCE OF ANOTHER
SHORTWAVE THAT WILL BE TRAVERSING THE SOUTHEASTERN STATES.
MEANWHILE...STRONG HIGH PRESSURE WILL BEGIN TO WEDGE SOUTHWARD INTO
OUR AREA BY LATE TUES...PUSHING A COLD FRONT SLOWLY SOUTHWARD
THROUGH OUR REGION TUES NIGHT. ANOTHER ROUND OF FOG WILL BE POSSIBLE
TUES NIGHT AHEAD OF THIS FRONT. FORCING ALOFT SHOULD BE MINIMAL ON
TUESDAY...WITH WIDELY SCATTERED SHOWERS NEAR THE ALTAMAHA AS THE
COLD FRONT MOVES THROUGH AND ALONG THE COAST AS ONSHORE FLOW
STRENGTHENS...WITH ONLY ISOLATED ACTIVITY ELSEWHERE. ABOVE NORMAL
TEMPS WILL PREVAIL AHEAD OF THIS COLD FRONT....WITH MID/UPPER 60S
FOR SOUTHEAST GA AND COASTAL NORTHEAST FL...WHILE 70S PERSIST FOR
INLAND NORTHEAST FL. AS ONSHORE FLOW STRENGTHENS TUES NIGHT AND WED
IN CONCERT WITH THE FRONT SLIPPING SOUTHWARD...ISOLATED TO WIDELY
SCATTERED SHOWERS WILL REMAIN POSSIBLE REGION-WIDE. LOWS NORTH OF
THE FRONT WILL FALL BACK TO THE 40S FOR SOUTHEAST GA TUES
NIGHT...WITH 50S FOR NORTHEAST FL.
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE SOUTHWARD INTO THE FL PENINSULA ON WEDNESDAY
AS HIGH PRESSURE OVER THE MID-ATLANTIC AND THE TENNESSEE VALLEY
WEDGES SOUTHWARD INTO OUR AREA. NORTHEAST FLOW AND WEAK ISENTROPIC
LIFT WILL KEEP ISOLATED SHOWERS IN THE FORECAST...WITH CLOUDS AND
COOL AIR ADVECTION KEEPING HIGHS IN THE 50S FOR SOUTHEAST GA...WITH
60S FOR NORTHEAST FL. A DEEPENING LONG WAVE TROUGH WILL DIG INTO THE
SOUTHEASTERN STATES BY WED NIGHT AND THURS...INDUCING CYCLOGENESIS
ALONG THE FRONTAL BOUNDARY IN THE GULF OF MEXICO. THIS WAVE OF LOW
PRESSURE WILL MIGRATE EASTWARD ACROSS THE FL PENINSULA ON
THURS...WITH STRONG ISENTROPIC LIFT DEVELOPING STEADY RAINFALL OVER
MUCH OF OUR REGION BY LATE WED NIGHT INTO THURS. RAIN CHANCES FOR
THESE TIME PERIODS MAY NEED TO BE INCREASED IN FUTURE FORECASTS.
LOWS WED NIGHT WILL RANGE FROM THE 40S NORTH OF I-10 TO THE 50S
ELSEWHERE. HIGHS THURS WILL REMAIN IN THE 50S NORTH OF I-10...WITH
60S ELSEWHERE. A FEW LINGERING SHOWERS WILL BE POSSIBLE THURS NIGHT
IN NORTHEAST FL AS A COLD FRONT DRIVES SOUTHEASTWARD.
A SEASONABLY COOL AND DRY AIR MASS WILL BUILD INTO OUR REGION FOR
FRI AND SAT AS COOL HIGH PRESSURE SETTLES OVER THE SOUTHEASTERN
STATES. HIGHS WILL GENERALLY RANGE FROM 55-60...WITH LOWS DROPPING
BACK TO THE 30S INLAND AND 40S AT THE COAST. TEMPERATURES WILL
MODERATE SATURDAY NIGHT AND NEXT SUNDAY AS HIGH PRESSURE MOVES OFF
THE U.S. EASTERN SEABOARD AND ONSHORE WINDS DEVELOP.
&&
.AVIATION...
THE HRRR MODEL HAS RECENTLY BACKED WAY OFF ON LOW CEILINGS THIS
MORNING AND THIS SEEMS TO BE PLAYING OUT AS ALL NORTHEAST FLORIDA
TAF SITES ARE NOW REPORTING VFR CONDITIONS. THE CEILING FORECAST
WILL BE DIFFICULT TO SAY THE LEAST THROUGHOUT THE DAY BUT THE
IMPROVED CEILING HEIGHTS WILL LIKELY CONTINUE THROUGH MUCH OF THE
MORNING BEFORE LOW CEILINGS REDEVELOP ALONG THE COAST EARLY THIS
AFTERNOON. RAIN SHOWERS WILL BE POSSIBLE AT THE COASTAL TERMINALS
OFF AN ON THROUGH THIS AFTERNOON. TIMING THIS ACTIVITY WILL PROVE
DIFFICULT BUT IMPACTS SHOULD BE BRIEF WITH MAINLY MVFR VISIBILITY
REDUCTIONS.
&&
.MARINE...
PREVAILING NORTHEAST TO EAST FLOW TODAY WITH SUSTAINED WINDS
GENERALLY AVERAGING 15 TO 20 KNOTS WITH THE HIGHER SPEEDS EXPECTED
OVER THE OFFSHORE WATERS. HAVE REPLACED THE SCA OVER THE NEARSHORE
WATERS WITH AN SCEC HEADLINE FOR TODAY. A DIMINISHING TREND IN THE
WINDS IS EXPECTED TONIGHT. AN SCA REMAINS IN EFFECT FOR THE
OFFSHORE WATERS THROUGH MONDAY TO ACCOUNT FOR THE POSSIBILITY OF
SEAS LINGERING IN THE 5 TO 7 FT RANGE. LIGHT WINDS WILL PREVAIL
MONDAY AND TUESDAY...BUT CONSIDERABLE UNCERTAINTY REMAINS IN THE SEA
HEIGHT FORECASTS. ANOTHER SURGE OF NORTH TO NORTHEAST WINDS AND
BUILDING SEAS IS EXPECTED TUESDAY NIGHT AND WEDNESDAY AS STRONG HIGH
PRESSURE BUILDS NORTH OF OUR REGION...PUSHING A COLD FRONT SOUTHWARD
THROUGH THE COASTAL WATERS. LOW PRESSURE WILL THEN MIGRATE EASTWARD
ACROSS THE FLORIDA PENINSULA ON THURSDAY...WITH A PERIOD OF STEADY
RAINFALL EXPECTED OVER THE COASTAL WATERS INTO THURSDAY EVENING.
RIP CURRENTS: MODERATE RISK TODAY DUE TO ONSHORE FLOW AND INCREASED
SURF.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 53 49 67 54 / 30 60 60 20
SSI 59 56 66 55 / 60 70 60 30
JAX 65 58 73 58 / 50 60 60 30
SGJ 70 62 72 60 / 60 50 60 30
GNV 70 60 76 58 / 20 60 60 20
OCF 76 62 77 60 / 20 50 60 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 5 PM EST MONDAY FOR ALTAMAHA SOUND GA
TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-FERNANDINA
BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-ST
AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ALTAMAHA
SOUND GA TO FERNANDINA BEACH FL OUT 20 NM-FERNANDINA BEACH
TO ST AUGUSTINE FL OUT 20 NM.
&&
$$
SHULER/NELSON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
902 PM CST MON JAN 12 2015
.UPDATE...
547 PM CST
MAIN FORECAST CONCERNS THIS EVENING ARE WITH ONGOING LAKE EFFECT
SNOW SHOWERS ACROSS PORTIONS OF NORTHEAST ILLINOIS AND NORTHWEST
INDIANA.
OVER THE LAST COUPLE OF HOURS...THERMODYNAMIC CONDITIONS OVER THE
LAKE HAVE BECOME INCREASINGLY MORE FAVORABLE FOR LAKE EFFECT SNOW
DEVELOPMENT ACROSS BOTH ILLINOIS AND INDIANA. THIS HAS INCLUDED
INCREASING INVERSION HEIGHTS AND DELTA TS COINCIDING WITH
STRENGTHENING LOW LEVEL CONVERGENCE ALONG THE SOUTHERN END OF THE
LAKE. THESE MORE FAVORABLE CONDITIONS LOOK TO REMAIN THROUGH AROUND
THE 2Z TIME FRAME TONIGHT...BEFORE CONDITIONS BEGIN TO BECOME LESS
FAVORABLE FROM THE POINT FORWARD INTO THE NIGHT. ALTHOUGH THE SNOW
SHOWERS WILL LIKELY PERSIST...THEY WILL BECOME LESS INTENSE WITH
TIME INTO THE LATE EVENING AND OVERNIGHT HOURS ESPECIALLY WITH THE
LOSS OF THE LARGE SCALE ASCENT OWING TO A PASSING MID LEVEL TROUGH.
VEERING LOW LEVEL FLOW FOR THE REMAINDER OF THE EVENING WILL FOCUS
THE DEVELOPMENT MORE INTO THE ILLINOIS SIDE...BUT WITH SOME FLURRIES
STILL POSSIBLE IN LAKE IN. APPROACHING THE 8-9Z TIME FRAME
TONIGHT...WORSENING THERMODYNAMIC CONDITIONS WILL CONTINUE AS MUCH
DRIER AIR BELOW THE INVERSION PUSH SOUTH DOWN THE LAKE WITH THE SNOW
DEVELOPMENT SHUTTING OFF TOWARDS EARLY TUESDAY MORNING.
A BROAD AREA OF LIGHT...BRIEFLY/ISOLATED MODERATE...SNOW WILL
CONTINUE THROUGH MID EVENING. VIS WILL LIKELY FALL TO
3-5SM...BRIEFLY FALLING TO 1-2SM UNDER ANY HEAVIER SNOW SHOWER WITH
THE CURRENT SNOWFALL FORECAST OF AT MOST AROUND AN INCH IN SOME
LOCATIONS NEAR THE LAKE STILL ON TRACK.
RODRIGUEZ
&&
.SHORT TERM...
233 PM CST
TONIGHT THROUGH TUESDAY...
MAIN FOCUS FOR THIS EVENING WILL BE ON THE POTENTIAL FOR A LAKE
EFFECT SNOW BAND TO SLOWLY PIVOT WEST AND IMPACT FAR NORTHEAST IL.
THROUGHOUT THIS AFTERNOON OCCASIONAL FLURRIES HAVE BEEN OBSERVED
ACROSS NORTHWEST IN...AND ALONG THE CHICAGO SHORELINE. ABUNDANT
SUNSHINE HAS DEVELOPED ELSEWHERE WITH TEMPS GENERALLY IN THE
MID/UPR TEENS. THE CLOUDS HAVE LINGERED LONGER ACROSS NORTHWEST
IN...WHICH HAS HELPED TO HOLD TEMPS UP A LITTLE IN THE LOW 20S.
LLVL FLOW IS GENERALLY FROM THE NORTH...HOWEVER SITES ACROSS
NORTHERN WISC HAVE STARTED TO TREND NORTHEASTERLY AS SFC RIDGING
CONTINUES TO BUILD IN FROM THE WEST.
BUT AS ELUDED TO EARLIER...THE MAIN CONCERN IS WITH THE SNOW BAND.
HI-RES LOCAL ARW8KM GUIDANCE HAS MAINTAINED A NARROW BAND STREAMING
SOUTH ACROSS THE LAKE THIS AFTN...THEN AS LLVL FLOW TURNS
NORTHEASTERLY...THIS BAND WILL BEGIN TO PIVOT WEST TOWARDS NORTHEAST
IL OR MAINLY COOK COUNTY. THIS APPEARS TO BE FOCUSED ON A 00Z
TIMEFRAME...THEN LIFTING NORTH TOWARDS LAKE COUNTY IL. THERE IS SOME
WEAK LLVL FORCING/CONVERGENCE ALONG THE SOUTHWEST TIP OF LAKE
MICHIGAN...WHICH COULD PROVIDE SOME MINOR BUMP TO THE INTENSITY OF
THIS BAND ACROSS NORTHEAST IL BETWEEN 02-06Z. OTHERWISE SHORTLY AFT
9Z TUE ENOUGH SCOURING FROM THE SFC RIDGE OVERHEAD WILL BRING AN END
TO THE LIGHT SNOW. FLURRIES MAY LINGER UNTIL JUST PRIOR TO DAYBREAK
TUE...THEN EXPECT MOSTLY SUNNY SKIES TO PREVAIL TUE.
GIVEN THE LOW LIQUID-RATIO...NOT EXPECTING MUCH ACCUMS TO OCCUR
WITH THIS BAND. HOWEVER WITH THAT BEING SAID...IT DOES APPEAR
BASED ON A FEW SITES USING THE COBB TECHNIQUE AROUND 1 INCH OF
SNOW MAY OCCUR IN PORTIONS OF NORTHERN COOK/LAKE COUNTY IL.
WITH THE LACK OF A ROBUST GRADIENT OVERNIGHT...TEMPS SHUD EASILY
RADIATE INTO THE SINGLE DIGITS ABOVE ZERO. A FEW SPOTS COULD DIP
BELOW ZERO OVERNIGHT ACROSS THE NORTHWEST CWFA. WIND CHILL VALUES
OVERNIGHT WILL BE BETWEEN -5 TO -14 DEGREES. THEN FOR TUE WITH AMPLE
SUNSHINE...DEPARTING MID-LVL TROUGH...TEMPS SHUD GENERALLY BE IN THE
MID/UPR TEENS. TUE NIGHT CONTINUED DRY CONDS ARE EXPECTED...WITH
ANOTHER COLD NIGHT AS LOWS DIP TO ARND ZERO TO A FEW DEGREES BELOW
ZERO.
WEDNESDAY...
SFC RIDGING STRETCHES FROM NEW ENGLAND SOUTHWEST ACROSS THE OHIO
VALLEY. GUIDANCE HAS CONTINUED TO BRING A MOISTURE STARVED BOUNDARY
EAST ACROSS THE CENTRAL CONUS EARLY WED...BRINGING AN INCREASE TO
MID/UPR LEVEL MOISTURE WED AFTN/EVE ACROSS THE FORECAST AREA. AT
THIS TIME EXPECT ENOUGH DRY AIR WITHIN THE BOUNDARY LYR TO MAINTAIN
DRY CONDS. THEN BY WED NGT SFC RIDGING APPEARS TO RETURN TO THE
MID-MISSOURI VALLEY. LLVL FLOW WILL BE LIGHT FROM THE
SOUTHWEST...WITH TEMPS REMAINING COOL FOR ONE MORE DAY IN THE LOW
20S.
BEACHLER
&&
.LONG TERM...
233 PM CST
THURSDAY THROUGH MONDAY...
ENSEMBLES CONTINUE TO LEAN TOWARDS A PATTERN ADJUSTMENTS FOR THE
SECOND HALF OF THE WEEK THROUGH THE WEEKEND. ALL SIGNALS POINT
TOWARDS A TRANSITION OUT OF THE COOL TROUGHING PATTERS ACROSS THE
GREAT LAKES...TOWARDS A RELATIVELY PROGRESSIVE SEMI-ZONAL FLOW. SFC
RIDGING SHUD MAINTAIN DRY CONDS THUR/FRI/SAT/SUN...WITH TEMPS
WARMING INTO THE UPR 20S THUR...MID 30S FRI...AND POSSIBLY TOUCHING
40 BY SAT AFTN. AT THIS TIME THE NEXT POSSIBILITY FOR APPRECIABLE
PRECIP APPEARS TO BE SUN EVE/MON.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LAKE EFFECT SNOW SHOWERS BECOMING LESS ORGANIZED. A FEW HOURS OF
LIGHT SHSN WITH MAINLY VFR/HIGH-END MVFR CIG AND VIS POSSIBLE
REMAINDER OF THIS EVENING.
* HIGH-END MVFR CIGS 2500-3000 FT LINGERING INTO TUESDAY MORNING.
* NORTH WINDS 10-15 KT THIS EVENING BECOMING NORTHEAST OVERNIGHT
AND DIMINISHING INTO TUESDAY MORNING.
RATZER
//DISCUSSION...UPDATED 00Z...
ONLY REAL CONCERN THROUGH THIS TAF PERIOD IS LAKE EFFECT SNOW
SHOWERS OVER THE CHICAGO METRO TERMINALS...AND THEIR IMPACT ON
VIS/CIGS ESPECIALLY THROUGH THIS EVENING.
REGIONAL RADAR MOSAIC DEPICTS BROAD AREA OF LIGHT-MODERATE
SPREADING SOUTH-SOUTHWEST OVER WESTERN LAKE MICHIGAN AND INTO LAKE
AND COOK COUNTIES OF ILLINOIS AND ACROSS NORTHWEST INDIANA.
ENVIRONMENTAL CONDITIONS FOR LAKE EFFECT SNOW APPEARS TO BE BEST
THIS EVENING...WITH INCREASING CONVERGENCE AND THE PASSAGE OF A
MID-LEVEL TROUGH AXIS MAXIMIZING OTHERWISE RELATIVELY UNIMPRESSIVE
SETUP FOR SIGNIFICANT LAKE SNOW. LOWERING INVERSION IN THE WAKE OF
THE MID LEVEL WAVE TONIGHT SHOULD HELP DECREASE THE INTENSITY OF
SNOW SHOWERS BEYOND THIS EVENING...WITH WARMING ALOFT AND EVENTUAL
SHIFT TO MORE EASTERLY WIND TUESDAY MORNING TO FURTHER DIMINISH
ORGANIZATION OF SNOW SHOWERS.
FOR THIS EVENING HOWEVER...EXPECT MVFR CIG/VIS CONDITIONS IN SNOW
SHOWERS FOR ORD ALONG WESTERN PERIPHERY OF BAND...WHILE MDW WILL
LIKELY SEE AN OCCASIONAL IFR VSBY 1 1/2SM TO 2SM CLOSER TO THE
LAKE AND MORE DIRECTION DOWN FETCH OF BOUNDARY LAYER WIND FIELD.
SNOW SHOWERS WILL LIKELY PRODUCE SOME MINOR ACCUMS...AGAIN
ESPECIALLY AT MDW. CONDITIONS LOOK TO FAVOR WEAKENING AND
DECREASING ORGANIZATION AFTER 04-05Z...WITH LIGHTER SNOW SHOWERS
AND FLURRIES LINGERING OVERNIGHT. CIGS GENERALLY MVFR EVEN IN SNOW
SHOWERS.
WINDS...NORTHERLY WINDS 350-010 EXPECTED TO SHIFT MORE 020-040
OVERNIGHT WITH SPEEDS NEAR 15 KT DIMINISHING BELOW 10 KT BY
MORNING. WINDS CONTINUE TO VEER TO THE EAST TUESDAY...AND MAY BE
LIGHT/VARIABLE AT TIMES TUES AFTN.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM HIGH IN SHSN/FLURRIES DURATION...BUT HIGH THAT IMPACTS
WILL BE MINIMAL WITH HIGH-MVFR OR VFR CONDITIONS.
* HIGH IN WIND TRENDS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY THROUGH SUNDAY...PRIMARILY VFR. CHANCE OF SNOW SUNDAY
NIGHT. SOUTHWEST WINDS WEDNESDAY THROUGH FRIDAY BECOMING WEST-
SOUTHWEST SATURDAY AND SUNDAY.
RATZER
&&
.MARINE...
248 PM CST
A WEAK SURFACE TROUGH EXTENDS FROM NEW ENGLAND THROUGH THE
CENTRAL GULF COAST. A LARGE AREA OF ARCTIC HIGH PRESSURE IS
CENTERED OVER MINNESOTA. LAKE MICHIGAN WILL REMAIN SITUATED
BETWEEN THE STRONG HIGH AND THE WEAK THROUGH TONIGHT...WITH
MODESTLY STRONG...AROUND 30KT...NORTH WINDS LATE THIS AFTERNOON
AND THEN GRADUALLY VEERING MORE NORTHEASTERLY TO EASTERLY AS THE
HIGH APPROACHES THE LAKE. HAVE MAINTAINED THE SMALL CRAFT ADVISORY
FOR THE ILLINOIS AND INDIANA NEARSHORE WATERS...GENERALLY FOR
STRONG WINDS...DUE TO ICE COVERAGE. HOWEVER...THE OPEN WATERS OF
THE LAKE REMAIN OPEN AND THE OUTER PORTIONS OF THE NEARSHORE
WATERS WILL LIKELY SEE WAVES HAZARDOUS TO SMALL CRAFT AS WELL.
WINDS WILL DIMINISH BEGINNING TUESDAY MORNING AS THE HIGH SPREADS
SOUTH AND EAST...WITH THE AXIS OF THE HIGH PRESSURE CROSSING THE
LAKE TUESDAY AFTERNOON AND EVENING. THE HIGH WILL SETTLE INTO THE
OHIO VALLEY WEDNESDAY NIGHT AND THURSDAY WHILE WEAKENING
MEANWHILE...LOW PRESSURE WILL DROP OUT OF THE NORTHERN CANADIAN
ROCKIES WEDNESDAY AFTERNOON...CROSSING LAKE WINNIPEG WEDNESDAY
EVENING AND THEN TRACKING EAST ACROSS CENTRAL ONTARIO WEDNESDAY
NIGHT AND THURSDAY. THIS WILL LEAD TO STRENGTHENING SWLY WINDS
OVER THE LAKE...WITH THE STRONGEST WINDS...ARND 20-25KT...OVER THE
NORTHERN PORTIONS OF THE LAKE WHERE THE PRESSURE GRADIENT WILL BE
STRONGEST.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM TUESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
840 PM CST Mon Jan 12 2015
.UPDATE...
ISSUED AT 835 PM CST MON JAN 12 2015
Cloud deck streaming south-southwest off of Lake Michigan affecting
mainly our eastern counties early this evening. However, the short
term models continue to suggest a more of a southwest to west push
in the clouds as the night wears on as boundary layer winds turn
more into the northeast and east. A few flurries possible out of
the stratocumulus deck, especially over our eaastern counties, but
coverage expected to be limited. The large Arctic high is expected
to push to our north over the next 24 hours keeping a northeast to
easterly flow, which eventually will steer what is left of the
stratocu deck out to our west late tonight and during the day on
Tuesday. Have made some adjustments to the sky cover and overnight
low temps, especially over the far northwest where a few locations
were a few degrees from the expected overnight low. Will have the
updated ZFP out by 900 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 246 PM CST MON JAN 12 2015
Low broken to overcast (MVFR) clouds over eastern IL this afternoon
will gradually diminish into this evening, though more lake effect
clouds from Lake MI could drift sw into parts of central IL later
this evening and overnight especially from I-74 ne. Brisk north
winds with gusts of 15 to 25 mph that is causing some blowing snow
in rural areas over central IL today will gradually diminish to
around 10 mph during the night and veer to the ne by Tue morning.
Strong 1047 mb arctic high pressure near the Dakotas/MN border will
drift east into the Great Lakes region Tue and bring dry and cold
weather to region into tomorrow. Went a bit colder with lows tonight
using CONSMOS guidance to near or just below zero nw by Knox and
Stark counties where wind chills will approach 15F below overnight.
Lows mostly in the single digits above zero tonight with low to mid
teens in southeast IL from I-70 south where there is no snow cover.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 246 PM CST MON JAN 12 2015
Cold high pressure from Canada will move across the Midwest through
early Wednesday bringing dry conditions and cold temperatures. High
temperatures in the upper teens and lower 20s are expected through
this time period, with lows Wednesday morning generally single
digits with a few below zero readings possible from I-74 northward.
A shortwave trough will move across the Midwest Wednesday into
Wednesday night bringing weak lift and potentially enough moisture
to bring scattered snow flurries. At this point, model precipitation
forecasts are light and scattered indicating not much chance for
significant snow accumulation. Have included chance of flurries for
this feature due to model trends toward a more amplified and moister
solution.
Following the Wednesday/Wednesday night shortwave, low level warm
advection and developing southerly flow under a mean 500 mb ridge
will bring a warming trend with highs becoming above normal...mainly
40s...by Saturday.
Next chance for precipitation doesn`t look until early next week at
least. Model forecasts still have not featured much consistency in
this time period, indicating significant uncertainty. Current round
of forecasts from morning model runs tending toward more of a split
flow pattern with a northern and southern stream disturbance around
Illinois with little impact, but can`t rule out either disturbance
tracking through Illinois instead at this point.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 510 PM CST MON JAN 12 2015
Main forecast concern will be lake clouds streaming southwest into
parts of our forecast area overnight as boundary layer winds become
more northeast. Current satellite data and upstream surface obs
continues to show a stream of moisture tracking south and southwest
into far easterly Illinois early this evening. Forecast soundings
off the HRRR and Rapid Refresh suggest we will see at least a
scattered deck at 1500-2000 feet at BMI, CMI and DEC. Later tonight
boundary layer winds are forecast to veer more into a northeast to
east direction, which may push the clouds even further to the west
late tonight. That is a low probability of occurrence at this point
so will not include a scattered group at PIA and SPI. Other than
the lake clouds, not much else to be concerned with as another
Arctic high settles into the region overnight. Gusty surface winds
will diminish this evening out of the north and turn more into a
northeast direction tonight with speeds ranging from 10 to 15 kts
at BMI, DEC and CMI, while dropping down to between 6 to 10 kts
further west at PIA and SPI. Look for a northeast wind at 10 to
15 kts on Tuesday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...07/EJL
LONG TERM...Onton
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
549 PM CST MON JAN 12 2015
.UPDATE...
547 PM CST
MAIN FORECAST CONCERNS THIS EVENING ARE WITH ONGOING LAKE EFFECT
SNOW SHOWERS ACROSS PORTIONS OF NORTHEAST ILLINOIS AND NORTHWEST
INDIANA.
OVER THE LAST COUPLE OF HOURS...THERMODYNAMIC CONDITIONS OVER THE
LAKE HAVE BECOME INCREASINGLY MORE FAVORABLE FOR LAKE EFFECT SNOW
DEVELOPMENT ACROSS BOTH ILLINOIS AND INDIANA. THIS HAS INCLUDED
INCREASING INVERSION HEIGHTS AND DELTA TS COINCIDING WITH
STRENGTHENING LOW LEVEL CONVERGENCE ALONG THE SOUTHERN END OF THE
LAKE. THESE MORE FAVORABLE CONDITIONS LOOK TO REMAIN THROUGH AROUND
THE 2Z TIME FRAME TONIGHT...BEFORE CONDITIONS BEGIN TO BECOME LESS
FAVORABLE FROM THE POINT FORWARD INTO THE NIGHT. ALTHOUGH THE SNOW
SHOWERS WILL LIKELY PERSIST...THEY WILL BECOME LESS INTENSE WITH
TIME INTO THE LATE EVENING AND OVERNIGHT HOURS ESPECIALLY WITH THE
LOSS OF THE LARGE SCALE ASCENT OWING TO A PASSING MID LEVEL TROUGH.
VEERING LOW LEVEL FLOW FOR THE REMAINDER OF THE EVENING WILL FOCUS
THE DEVELOPMENT MORE INTO THE ILLINOIS SIDE...BUT WITH SOME FLURRIES
STILL POSSIBLE IN LAKE IN. APPROACHING THE 8-9Z TIME FRAME
TONIGHT...WORSENING THERMODYNAMIC CONDITIONS WILL CONTINUE AS MUCH
DRIER AIR BELOW THE INVERSION PUSH SOUTH DOWN THE LAKE WITH THE SNOW
DEVELOPMENT SHUTTING OFF TOWARDS EARLY TUESDAY MORNING.
A BROAD AREA OF LIGHT...BRIEFLY/ISOLATED MODERATE...SNOW WILL
CONTINUE THROUGH MID EVENING. VIS WILL LIKELY FALL TO
3-5SM...BRIEFLY FALLING TO 1-2SM UNDER ANY HEAVIER SNOW SHOWER WITH
THE CURRENT SNOWFALL FORECAST OF AT MOST AROUND AN INCH IN SOME
LOCATIONS NEAR THE LAKE STILL ON TRACK.
RODRIGUEZ
&&
.SHORT TERM...
233 PM CST
TONIGHT THROUGH TUESDAY...
MAIN FOCUS FOR THIS EVENING WILL BE ON THE POTENTIAL FOR A LAKE
EFFECT SNOW BAND TO SLOWLY PIVOT WEST AND IMPACT FAR NORTHEAST IL.
THROUGHOUT THIS AFTERNOON OCCASIONAL FLURRIES HAVE BEEN OBSERVED
ACROSS NORTHWEST IN...AND ALONG THE CHICAGO SHORELINE. ABUNDANT
SUNSHINE HAS DEVELOPED ELSEWHERE WITH TEMPS GENERALLY IN THE
MID/UPR TEENS. THE CLOUDS HAVE LINGERED LONGER ACROSS NORTHWEST
IN...WHICH HAS HELPED TO HOLD TEMPS UP A LITTLE IN THE LOW 20S.
LLVL FLOW IS GENERALLY FROM THE NORTH...HOWEVER SITES ACROSS
NORTHERN WISC HAVE STARTED TO TREND NORTHEASTERLY AS SFC RIDGING
CONTINUES TO BUILD IN FROM THE WEST.
BUT AS ELUDED TO EARLIER...THE MAIN CONCERN IS WITH THE SNOW BAND.
HI-RES LOCAL ARW8KM GUIDANCE HAS MAINTAINED A NARROW BAND STREAMING
SOUTH ACROSS THE LAKE THIS AFTN...THEN AS LLVL FLOW TURNS
NORTHEASTERLY...THIS BAND WILL BEGIN TO PIVOT WEST TOWARDS NORTHEAST
IL OR MAINLY COOK COUNTY. THIS APPEARS TO BE FOCUSED ON A 00Z
TIMEFRAME...THEN LIFTING NORTH TOWARDS LAKE COUNTY IL. THERE IS SOME
WEAK LLVL FORCING/CONVERGENCE ALONG THE SOUTHWEST TIP OF LAKE
MICHIGAN...WHICH COULD PROVIDE SOME MINOR BUMP TO THE INTENSITY OF
THIS BAND ACROSS NORTHEAST IL BETWEEN 02-06Z. OTHERWISE SHORTLY AFT
9Z TUE ENOUGH SCOURING FROM THE SFC RIDGE OVERHEAD WILL BRING AN END
TO THE LIGHT SNOW. FLURRIES MAY LINGER UNTIL JUST PRIOR TO DAYBREAK
TUE...THEN EXPECT MOSTLY SUNNY SKIES TO PREVAIL TUE.
GIVEN THE LOW LIQUID-RATIO...NOT EXPECTING MUCH ACCUMS TO OCCUR
WITH THIS BAND. HOWEVER WITH THAT BEING SAID...IT DOES APPEAR
BASED ON A FEW SITES USING THE COBB TECHNIQUE AROUND 1 INCH OF
SNOW MAY OCCUR IN PORTIONS OF NORTHERN COOK/LAKE COUNTY IL.
WITH THE LACK OF A ROBUST GRADIENT OVERNIGHT...TEMPS SHUD EASILY
RADIATE INTO THE SINGLE DIGITS ABOVE ZERO. A FEW SPOTS COULD DIP
BELOW ZERO OVERNIGHT ACROSS THE NORTHWEST CWFA. WIND CHILL VALUES
OVERNIGHT WILL BE BETWEEN -5 TO -14 DEGREES. THEN FOR TUE WITH AMPLE
SUNSHINE...DEPARTING MID-LVL TROUGH...TEMPS SHUD GENERALLY BE IN THE
MID/UPR TEENS. TUE NIGHT CONTINUED DRY CONDS ARE EXPECTED...WITH
ANOTHER COLD NIGHT AS LOWS DIP TO ARND ZERO TO A FEW DEGREES BELOW
ZERO.
WEDNESDAY...
SFC RIDGING STRETCHES FROM NEW ENGLAND SOUTHWEST ACROSS THE OHIO
VALLEY. GUIDANCE HAS CONTINUED TO BRING A MOISTURE STARVED BOUNDARY
EAST ACROSS THE CENTRAL CONUS EARLY WED...BRINGING AN INCREASE TO
MID/UPR LEVEL MOISTURE WED AFTN/EVE ACROSS THE FORECAST AREA. AT
THIS TIME EXPECT ENOUGH DRY AIR WITHIN THE BOUNDARY LYR TO MAINTAIN
DRY CONDS. THEN BY WED NGT SFC RIDGING APPEARS TO RETURN TO THE
MID-MISSOURI VALLEY. LLVL FLOW WILL BE LIGHT FROM THE
SOUTHWEST...WITH TEMPS REMAINING COOL FOR ONE MORE DAY IN THE LOW
20S.
BEACHLER
&&
.LONG TERM...
233 PM CST
THURSDAY THROUGH MONDAY...
ENSEMBLES CONTINUE TO LEAN TOWARDS A PATTERN ADJUSTMENTS FOR THE
SECOND HALF OF THE WEEK THROUGH THE WEEKEND. ALL SIGNALS POINT
TOWARDS A TRANSITION OUT OF THE COOL TROUGHING PATTERS ACROSS THE
GREAT LAKES...TOWARDS A RELATIVELY PROGRESSIVE SEMI-ZONAL FLOW. SFC
RIDGING SHUD MAINTAIN DRY CONDS THUR/FRI/SAT/SUN...WITH TEMPS
WARMING INTO THE UPR 20S THUR...MID 30S FRI...AND POSSIBLY TOUCHING
40 BY SAT AFTN. AT THIS TIME THE NEXT POSSIBILITY FOR APPRECIABLE
PRECIP APPEARS TO BE SUN EVE/MON.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* LAKE EFFECT SNOW SHOWERS THIS EVENING...MVFR CONDITIONS LIKELY
THROUGH BRIEF IFR VSBY IS POSSIBLE IN SHSN PARTICULARLY FOR
MDW. SNOW EXPECTED TO TAPER TO FLURRIES OVERNIGHT.
* NORTH WINDS 10-15 KT WITH A FEW HIGHER GUSTS POSSIBLE THIS
EVENING BECOMING NORTHEAST OVERNIGHT AND DIMINISHING INTO
TUESDAY MORNING.
RATZER
//DISCUSSION...UPDATED 00Z...
ONLY REAL CONCERN THROUGH THIS TAF PERIOD IS LAKE EFFECT SNOW
SHOWERS OVER THE CHICAGO METRO TERMINALS...AND THEIR IMPACT ON
VIS/CIGS ESPECIALLY THROUGH THIS EVENING.
REGIONAL RADAR MOSAIC DEPICTS BROAD AREA OF LIGHT-MODERATE
SPREADING SOUTH-SOUTHWEST OVER WESTERN LAKE MICHIGAN AND INTO LAKE
AND COOK COUNTIES OF ILLINOIS AND ACROSS NORTHWEST INDIANA.
ENVIRONMENTAL CONDITIONS FOR LAKE EFFECT SNOW APPEARS TO BE BEST
THIS EVENING...WITH INCREASING CONVERGENCE AND THE PASSAGE OF A
MID-LEVEL TROUGH AXIS MAXIMIZING OTHERWISE RELATIVELY UNIMPRESSIVE
SETUP FOR SIGNIFICANT LAKE SNOW. LOWERING INVERSION IN THE WAKE OF
THE MID LEVEL WAVE TONIGHT SHOULD HELP DECREASE THE INTENSITY OF
SNOW SHOWERS BEYOND THIS EVENING...WITH WARMING ALOFT AND EVENTUAL
SHIFT TO MORE EASTERLY WIND TUESDAY MORNING TO FURTHER DIMINISH
ORGANIZATION OF SNOW SHOWERS.
FOR THIS EVENING HOWEVER...EXPECT MVFR CIG/VIS CONDITIONS IN SNOW
SHOWERS FOR ORD ALONG WESTERN PERIPHERY OF BAND...WHILE MDW WILL
LIKELY SEE AN OCCASIONAL IFR VSBY 1 1/2SM TO 2SM CLOSER TO THE
LAKE AND MORE DIRECTION DOWN FETCH OF BOUNDARY LAYER WIND FIELD.
SNOW SHOWERS WILL LIKELY PRODUCE SOME MINOR ACCUMS...AGAIN
ESPECIALLY AT MDW. CONDITIONS LOOK TO FAVOR WEAKENING AND
DECREASING ORGANIZATION AFTER 04-05Z...WITH LIGHTER SNOW SHOWERS
AND FLURRIES LINGERING OVERNIGHT. CIGS GENERALLY MVFR EVEN IN SNOW
SHOWERS.
WINDS...NORTHERLY WINDS 350-010 EXPECTED TO SHIFT MORE 020-040
OVERNIGHT WITH SPEEDS NEAR 15 KT DIMINISHING BELOW 10 KT BY
MORNING. WINDS CONTINUE TO VEER TO THE EAST TUESDAY...AND MAY BE
LIGHT/VARIABLE AT TIMES TUES AFTN.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH IN MVFR CONDITIONS IN SNOW SHOWERS THIS EVE FOR ORD AND
OCCASIONAL IFR MAINLY AT MDW.
* MEDIUM IN TIMING OF SNOW SHOWER DIMINISHING/ENDING OVERNIGHT.
* HIGH IN WIND TRENDS...AND IN VFR CONDITIONS DEVELOPING TUESDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY THROUGH SUNDAY...PRIMARILY VFR. CHANCE OF SNOW SUNDAY
NIGHT. SOUTHWEST WINDS WEDNESDAY THROUGH FRIDAY BECOMING WEST-
SOUTHWEST SATURDAY AND SUNDAY.
RATZER
&&
.MARINE...
248 PM CST
A WEAK SURFACE TROUGH EXTENDS FROM NEW ENGLAND THROUGH THE
CENTRAL GULF COAST. A LARGE AREA OF ARCTIC HIGH PRESSURE IS
CENTERED OVER MINNESOTA. LAKE MICHIGAN WILL REMAIN SITUATED
BETWEEN THE STRONG HIGH AND THE WEAK THROUGH TONIGHT...WITH
MODESTLY STRONG...AROUND 30KT...NORTH WINDS LATE THIS AFTERNOON
AND THEN GRADUALLY VEERING MORE NORTHEASTERLY TO EASTERLY AS THE
HIGH APPROACHES THE LAKE. HAVE MAINTAINED THE SMALL CRAFT ADVISORY
FOR THE ILLINOIS AND INDIANA NEARSHORE WATERS...GENERALLY FOR
STRONG WINDS...DUE TO ICE COVERAGE. HOWEVER...THE OPEN WATERS OF
THE LAKE REMAIN OPEN AND THE OUTER PORTIONS OF THE NEARSHORE
WATERS WILL LIKELY SEE WAVES HAZARDOUS TO SMALL CRAFT AS WELL.
WINDS WILL DIMINISH BEGINNING TUESDAY MORNING AS THE HIGH SPREADS
SOUTH AND EAST...WITH THE AXIS OF THE HIGH PRESSURE CROSSING THE
LAKE TUESDAY AFTERNOON AND EVENING. THE HIGH WILL SETTLE INTO THE
OHIO VALLEY WEDNESDAY NIGHT AND THURSDAY WHILE WEAKENING
MEANWHILE...LOW PRESSURE WILL DROP OUT OF THE NORTHERN CANADIAN
ROCKIES WEDNESDAY AFTERNOON...CROSSING LAKE WINNIPEG WEDNESDAY
EVENING AND THEN TRACKING EAST ACROSS CENTRAL ONTARIO WEDNESDAY
NIGHT AND THURSDAY. THIS WILL LEAD TO STRENGTHENING SWLY WINDS
OVER THE LAKE...WITH THE STRONGEST WINDS...ARND 20-25KT...OVER THE
NORTHERN PORTIONS OF THE LAKE WHERE THE PRESSURE GRADIENT WILL BE
STRONGEST.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM TUESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
512 PM CST Mon Jan 12 2015
.SHORT TERM...(Tonight)
ISSUED AT 246 PM CST MON JAN 12 2015
Low broken to overcast (MVFR) clouds over eastern IL this afternoon
will gradually diminish into this evening, though more lake effect
clouds from Lake MI could drift sw into parts of central IL later
this evening and overnight especially from I-74 ne. Brisk north
winds with gusts of 15 to 25 mph that is causing some blowing snow
in rural areas over central IL today will gradually diminish to
around 10 mph during the night and veer to the ne by Tue morning.
Strong 1047 mb arctic high pressure near the Dakotas/MN border will
drift east into the Great Lakes region Tue and bring dry and cold
weather to region into tomorrow. Went a bit colder with lows tonight
using CONSMOS guidance to near or just below zero nw by Knox and
Stark counties where wind chills will approach 15F below overnight.
Lows mostly in the single digits above zero tonight with low to mid
teens in southeast IL from I-70 south where there is no snow cover.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 246 PM CST MON JAN 12 2015
Cold high pressure from Canada will move across the Midwest through
early Wednesday bringing dry conditions and cold temperatures. High
temperatures in the upper teens and lower 20s are expected through
this time period, with lows Wednesday morning generally single
digits with a few below zero readings possible from I-74 northward.
A shortwave trough will move across the Midwest Wednesday into
Wednesday night bringing weak lift and potentially enough moisture
to bring scattered snow flurries. At this point, model precipitation
forecasts are light and scattered indicating not much chance for
significant snow accumulation. Have included chance of flurries for
this feature due to model trends toward a more amplified and moister
solution.
Following the Wednesday/Wednesday night shortwave, low level warm
advection and developing southerly flow under a mean 500 mb ridge
will bring a warming trend with highs becoming above normal...mainly
40s...by Saturday.
Next chance for precipitation doesn`t look until early next week at
least. Model forecasts still have not featured much consistency in
this time period, indicating significant uncertainty. Current round
of forecasts from morning model runs tending toward more of a split
flow pattern with a northern and southern stream disturbance around
Illinois with little impact, but can`t rule out either disturbance
tracking through Illinois instead at this point.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 510 PM CST MON JAN 12 2015
Main forecast concern will be lake clouds streaming southwest into
parts of our forecast area overnight as boundary layer winds become
more northeast. Current satellite data and upstream surface obs
continues to show a stream of moisture tracking south and southwest
into far easterly Illinois early this evening. Forecast soundings
off the HRRR and Rapid Refresh suggest we will see at least a
scattered deck at 1500-2000 feet at BMI, CMI and DEC. Later tonight
boundary layer winds are forecast to veer more into a northeast to
east direction, which may push the clouds even further to the west
late tonight. That is a low probability of occurrence at this point
so will not include a scattered group at PIA and SPI. Other than
the lake clouds, not much else to be concerned with as another
Arctic high settles into the region overnight. Gusty surface winds
will diminish this evening out of the north and turn more into a
northeast direction tonight with speeds ranging from 10 to 15 kts
at BMI, DEC and CMI, while dropping down to between 6 to 10 kts
further west at PIA and SPI. Look for a northeast wind at 10 to
15 kts on Tuesday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07/EJL
LONG TERM...Onton
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
200 PM CST SUN JAN 11 2015
.SHORT TERM...
325 AM CST
THROUGH MONDAY NIGHT...
UPPER LEVEL FLOW IS ZONAL WITH A SHORTWAVE TROUGH OVER TX. THE WAVE
WEAKENS AS IT MOVES OVER CENTRAL IL THIS EVENING. A SECOND SHORTWAVE
IS OVER THE DESERT SOUTHWEST AND IT WILL WEAKEN AS IT MOVES OVER THE
REGION MONDAY MORNING. AN UPPER LEVEL TROUGH IS STRETCHED OUT OVER
SOUTHERN CANADA AND IT/S TROUGH AXIS PASSES THROUGH THE REGION
MONDAY NIGHT.
A SURFACE HIGH IS OVER THE CENTRAL ATLANTIC COAST WHILE A WEAK
TROUGH/COLD FRONT STRETCHES FROM IOWA THROUGH SOUTHERN ONTARIO. THE
TROUGH/COLD FRONT WILL SAG SOUTH OVER THE CWA LATE THIS AFTERNOON
INTO THIS EVENING WHILE THE WEAK SURFACE LOW ASSOCIATED WITH THE
TROUGH SHIFTS NORTHEAST INTO SOUTHWEST QUEBEC. THE OTHER PLAYER IS
A LARGE HIGH PRESSURE SYSTEM CURRENTLY OVER SOUTHWEST CANADA WILL
SHIFT SOUTHEAST REACHING THE NORTHERN PLAINS TONIGHT BEFORE MOVING
OVER OUR NECK OF THE WOODS TUESDAY.
MOISTURE SURGES NORTH WITH THE FIRST SHORTWAVE TROUGH THIS AFTERNOON
AND EVENING. THERE SHOULD BE AMPLE LIFT FROM THE ON GOING WAA AND
ALONG THE TROUGH/COLD FRONT. GUIDANCE CONTINUES TO FEATURE A BAND
OF DECENT FRONTOGENESIS SINKING SOUTHEAST THROUGH THE CWA THIS
EVENING. THE NAM IS MORE EXCITED ABOUT THE FORCING THAN THE GFS.
THE NAM FEATURES A STRONG BAND STRETCHING FROM CHICAGO THROUGH LA
SALLE AT MIDNIGHT THAT QUICKLY SHIFTS SOUTHEAST TO A DETROIT MI TO
GIBSON CITY IL LINE BY 6AM MONDAY. THE GFS SHOWS A SIMILAR
PROGRESSION...JUST WEAKER. WHILE THE BAND IS IMPRESSIVE...OTHER
FACTORS SUCH AS EPV ARE MISSING SO I AM NOT EXCITED ABOUT INTENSE
BANDS OF SNOW. THAT BEING SAID...SOME ENHANCED BANDS OF SNOW MAY
FORM LEADING TO LOCALIZED HIGHER SNOW TOTALS.
PRECIP SPREADS NORTH THIS AFTERNOON WITH PRECIP FALLING SOUTH OF A
WAUKEGAN TO ROCKFORD LINE BY 6PM CST. EXPECTING SNOW FOR ALL AREAS
EXCEPT THOSE SOUTH OF A PONTIAC IL TO RENSSELAER INDIANA LINE.
SOUNDINGS SOUTH OF THIS LINE FEATURE PARTIAL MELTING ALOFT THAT MAY
LEAD TO SLEET MIXED WITH SNOW. NOT SURE HOW LONG SLEET OR A MIX OF
SLEET AND SNOW WILL FALL SOUTH OF THIS LINE AS COOLING MAY HELP THE
PRECIP TURN OVER TO ALL SNOW SOONER THAN FORECAST. IF THAT
HAPPENS...SNOW AMOUNTS WILL BE HIGHER THAN CURRENTLY FORECAST.
FOR THE AREAS NORTH OF THE PONTIAC TO RENSSELAER LINE...STEADY LIGHT
TO MODERATE SNOW IS EXPECTED THROUGH THE EVENING. A FEW BANDS OF
MODERATE TO POSSIBLY HEAVY SNOW MAY FORM ALONG AND SOUTH OF A
CHICAGO TO LA SALLE LINE AFTER MIDNIGHT. EXPECTING ALL SNOW ACROSS
THE CWA AFTER MIDNIGHT AND THE SNOW SLOWLY EXITS TO THE SOUTHEAST
THROUGH MID MONDAY MORNING.
HAVE LOWER STORM TOTAL SNOWFALL AMOUNTS THAN THE PREVIOUS FORECAST
DUE TO LESS CONFIDENCE IN BANDS OF HEAVIER SNOW AND HIGHER
CONFIDENCE IN SLEET MIXED WITH SNOW IN THE SOUTHERN CWA. EXPECTING
1 TO 2 INCHES ALONG AND SOUTH OF A OHARE TO AMBOY LINE WITH 1 TO
3...MAYBE LOCALIZED 4 INCHES SOUTH OF A GARY INDIANA TO LA SALLE
LINE.
WINDS TURN NORTH MONDAY LEADING TO THE POSSIBILITY OF LAKE EFFECT
SNOW OVER NW INDIANA MONDAY. STILL NOT OVERLY IMPRESSED WITH THE
LAKE EFFECT SET UP AS WELL WITH VERY MARGINAL DELTA T/S...DRY
FORECAST SOUNDINGS...AND SOME ICE OVER THE LAKE. AS SUCH CAPPED
POPS IN THE CHANCE RANGE. WINDS VEER TO NORTHEAST MONDAY EVENING
AND THE BAND OF SNOW SHIFTS WEST TO OVER ILLINOIS.
TEMPS MONDAY WILL VARY FROM THE MID TEENS OVER NORTH CENTRAL IL TO
THE MID 20S OVER NW INDIANA. LOWS WILL VARY FROM AROUND +10
DOWNTOWN TO 0 TO +5 IN OUTLYING AREAS. SOME ISOLATED LOCATIONS MAY
DIP BELOW ZERO.
JEE
&&
.LONG TERM...
325 AM CST
TUESDAY THROUGH SATURDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE CONUS TUESDAY WITH TROUGH
AXES/SHORTWAVES MOVING THROUGH THE REGION TUESDAY...WEDNESDAY AND
THURSDAY. THE SURFACE HIGH SITS OVER THE CWA TUESDAY AND SLOWLY
SINKS SOUTH WEDNESDAY. A CLIPPER SYSTEM PASSES TO OUR NORTH
WEDNESDAY NIGHT INTO THURSDAY WITH ANOTHER SURFACE HIGH MOVING OVER
THE REGION LATE IN THE WEEK.
LOOKING AT A DRY REST OF THE WEEK WITH HIGH TEMPS IN THE TEENS
TUESDAY AND WEDNESDAY. THEN WE GET INTO A WARMING TREND WITH AT OR
SLIGHTLY ABOVE FREEZING HIGH TEMPS BY THE END OF THE WEEK. THE ONLY
REALLY COLD NIGHT IS TUESDAY NIGHT WITH LOWS BETWEEN 0 AND -10 AWAY
FROM THE CITY BUT LIGHT WINDS WILL KEEP WIND CHILLS WARMER THAN
-20.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SNOW DEVELOPING BETWEEN 5-7 PM THIS EVENING. BRIEF (APPROX 1
HR) PERIOD OF VERY LGT SNOW/FLURRIES EXPECTED BEFORE MAIN SNOW
AREA... BETWEEN 3-4 PM AT MDW AND 4-5 PM AT ORD.
* HIGHLY VARYING VSBYS... CIGS... AND SNOW RATE/INTENSITY DURING
THIS EVENT.
* IFR VSBY WITH PERIODIC LIFR POSSIBLE IN VARIABLE BANDS OF SNOW.
CIGS LOWER TO MVFR/IFR THIS EVENING.
* SOUTH TO SOUTHWEST WINDS TURN NORTHWEST OVERNIGHT AND INCREASE
OUT OF THE NORTH MONDAY.
ED F
//DISCUSSION...UPDATED 18Z...
WET SNOW TO COMMENCE AROUND THE 23Z (MDW) AND 00Z (ORD) HOUR WITH
CIGS AND VSBYS TO LOWER QUICKLY WITH SNOW ONSET AS IT SPREADS FROM
SOUTH TO NORTH. THIS EVENT CONTINUES TO APPEAR THAT IT WILL POSSES
A BANDED NATURE OF THE SNOW BANDS... WHICH MAY RESULT IN HEAVIER
SNOW/HIGHER ACCUMULATIONS WHERE THE HEAVIER BANDS SET UP. OTHER
THAN THAT...GENERALLY SPEAKING AREAS TOWARD THE SOUTH AND EAST
WILL POTENTIALLY SEE A LONGER DURATION SNOW EVENT AND HENCE A
HIGHER OVERALL ACCUMULATION. PRECIPITATION TYPE TO REMAIN ALL SNOW
ACROSS THE CHICAGO METRO... BUT SLEET WILL BE ONLY AROUND 50 MILES
SOUTH.
THE TRANSIENT BANDED NATURE OF THE SNOW CONTINUES TO THUS
SUGGESTED HIGH VARIABILITY IN CIGS AND ESPECIALLY VSBYS THROUGHOUT
THE COURSE OF THE EVENING. SEEING SOME AGREEMENT AND CONSISTENCY
IN THE HIGH RESOLUTION MODELS FOR TWO SEPARATE BEST PERIODS OF
OPPORTUNITY FOR BRIEF PERIODS OF HEAVIER SNOW (45-90 MINUTE
DURATION EACH) PERHAPS CENTERED AROUND THE 23Z-01Z AND 03Z-05Z
TIME FRAMES. HAVE HIGHLIGHTED THESE WINDOWS FOR EXPECTED POORER
CONDITIONS IN THE TAFS... HOWEVER IDENTIFYING THESE WINDOWS
REMAINS A CHALLENGE AND IS SUBJECT TO CHANGE.
RFD EXPECTED TO REMAIN JUST NORTH OF THE SNOW BUT MAY SEE A BRIEF
DURATION VERY LIGHT ACCUMULATION. SOUTH TO SOUTHWEST WIND WILL
TURN NORTHWEST TO NORTH OVERNIGHT BEHIND A COLD FRONT. EXPECT MVFR
CIGS TO LIFT TO VFR BY SUNRISE WITH DRYER AIR SPREADING IN BEHIND
THE FRONT.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN SNOW... MEDIUM TO HIGH CONFIDENCE IN TIMING.
* HIGH CONFIDENCE THAT CONDITIONS WILL BE HIGHLY VARIABLE... LOW
CONFIDENCE ON SPECIFIC TIMING AND DURATION OF POOREST (VSBYS AND
CIGS) CONDITIONS.
* HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS POSSIBLE. A CHANCE OF LIGHT SNOW SHOWERS. NORTH
WINDS.
TUESDAY...MVFR CIGS POSSIBLE. NORTHEAST-EAST WINDS.
WEDNESDAY THROUGH SATURDAY...PRIMARILY VFR. SOUTHWEST TO WEST
WINDS.
MDB
&&
.MARINE...
254 AM CST
WEAK LOW PRESSURE IS MOVING ACROSS UPPER MICHIGAN THIS MORNING WITH
A TROUGH AXIS/COLD FRONT TRAILING IT TO THE SOUTHWEST. STRONG HIGH
PRESSURE OVER THE CAROLINA COAST WILL SHIFT OFFSHORE THROUGH THE DAY
ALLOWING THE SURFACE TROUGH TO SAG SOUTHEASTWARD INTO TONIGHT. THE
FAIRLY STRONG PRESSURE GRADIENT ACROSS LAKE MICHIGAN EARLY THIS
MORNING CONTINUES TO GENERATE STEADY WINDS BUT SPEEDS WILL STEADILY
DIMINISH THROUGH THE MORNING AS THE PRESSURE GRADIENT WEAKENS. WINDS
WILL SHIFT TO THE NORTHWEST TONIGHT AS THE FRONT PASSES WITH A
FURTHER SHIFT TO THE NORTH OCCURRING MONDAY MORNING. STRONG HIGH
PRESSURE ACROSS CENTRAL CANADA THIS MORNING WILL STRENGTHEN AS IT
MOVES SOUTHEAST INTO THE EASTERN DAKOTAS OVERNIGHT. AS A
RESULT...SPEEDS WILL PICK UP WITH GUSTS TO AROUND 25 KT LIKELY WITH
SOME CLOSER TO 30 KT POSSIBLE AT TIMES DURING THE DAY MONDAY BEFORE
WINDS TURN MORE TO THE NORTHEAST AND EASE MONDAY EVENING/NIGHT AS
THE HIGH SPREADS ACROSS THE LAKES.
THE HIGH WILL SHIFT SOUTH OF THE GREAT LAKES LATER WEDNESDAY. A
SERIES OF LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK ACROSS SOUTHERN
CANADA AND THE NORTHERN TIER OF STATES INTO LATE WEEK LEADING TO
PERIODIC WIND SHIFTS AND INCREASES IN SPEED.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1158 AM CST Sun Jan 11 2015
.UPDATE...
ISSUED AT 1045 AM CST SUN JAN 11 2015
Will continue the winter weather advisory from this afternoon
until 9 am Monday morning from Lincoln and Rantoul south for a
wintery mix of precipitation. Have nudged temperatures up a bit
today as current mercury levels running 1-2 degrees warmer with
most areas in the lower 30s (ranging from 29F at Galesburg to 36
at Mount Carmel airport). But low dewpoints in the mid teens to
lower 20s with wet bulb zero readings in the mid to upper 20s will
cause temps to slip back 1-2F as precipitation moves in from the
south during this afternoon. Radar shows a narrow band of light
precipitation lifting north of I-72 but most of this appears to be
virga with dry low levels. Litchfield had a 1-2 hour period of
light sleet with this band earlier this morning. Main area of
precipitation is lifting northward into southern IL (south of
I-64) and should overspread central/se IL during the afternoon.
Have brought in a mix of light freezing rain and light rain into
southeast IL southeast of I-70 this afternoon which continues into
this evening and this could lower their ice accumulations south of
I-70. Light snow and sleet expected to develop north of winter wx
advisory area in frontogenetic band setting up over the IL river
valley later this afternoon, with half to 1 inch of snow by dusk.
Mixture of light freezing rain and sleet expected over heart of
central IL especially from Lincoln south to I-70 with ice
accumulations generally less than a tenth of an inch through dusk.
More snow and ice acculuations expected tonight with 1-2 inches north
and one to two tenths inch ice central sections and less than a
tenth inch of ice southeast of I-70 near highway 50 in southern 3
counties.
&&
.SHORT TERM...(Today)
ISSUED AT 341 AM CST SUN JAN 11 2015
Warm air surging north ahead of the next cold front will ride up and
over the cold dome of air in place across central IL. 40kt of
isentropic lift along the 300K surface will help the layer of clouds
around 6K FT deepen with time as additional moisture arrives. Light
freezing rain or sleet will advance northward this morning, possibly
reaching our southern counties a little before Noon. At the same
time, a frontogenetical circulation across our northern counties
will work to produce light snow/sleet north of a line from
Bloomington to Havana, and especially from Peoria and north. The
models have shown this band of snow over the past several runs. So
it is possible we could have a region in the central portion of our
forecast area (generally along I-72) remain dry while snow falls
north and freezing rain/sleet falls to the south. Eventually we
should see freezing rain/sleet overspread our central counties up to
I-72 and continue into the evening. 00z/NAM soundings definitely
show a warm bias over the cooler GFS and ECMWF. We trended slightly
warmer with surface temps across the southerly half of the area as a
result, and pushed chances of freezing rain farther north as well.
In light of the northward trend for icing from freezing rain, in
conjunction with snow/sleet later in the event, we expanded the
advisory area northward another row of counties to now include
Champaign and Lincoln. Icing potential from freezing rain could
climb between one and two tenths of an inch toward the I-70
corridor. There is low potential for isolated areas to see a quarter
inch of ice, which is our trigger for an ice storm warning. If the
warmer trend is correct, our southern counties along highway 50
could become all rain later this afternoon and early evening, which
would reduce ice totals as you headed south of I-70.
The 00z/NAM is also indicating an extended period of sleet will be
possible toward I-72. If that developed, we could see 0.5" of sleet,
which is one trigger for a winter storm warning. At this point, we
do not have high enough confidence of widespread areas receiving
0.25" of ice nor 0.5" of sleet to warrant an upgrade to a winter
storm warning. We will keep the headlines as an advisory. QPF
amounts in general do not seem to support ice and sleet
accumulations that high from this event.
Even models generally lower on QPF, there is evidence in the GFS and
NAM of banded precipitation, which could create large variations in
snow/sleet/ice amounts over short distances. There is a 100mb layer
of the Fn convergent portion of frontogenesis across our forecast
area, with negative EPV just above that layer to allow for CSI-type
banding. Pinpointing those bands is difficult even this close to the
event. As hourly HRRR and RAP model updates come in and we compare
to satellite and radar, we will have a better chance to do short
term updates on snow/sleet/ice amounts where bands appear more
likely.
For now, we will stick with snow totals north of I-72 in the 1-2"
range, with ice totals of in the 0.1-0.2" range with the highest
amounts along the I-70 corridor. Sleet totals would reduce snow
amounts along the I-72 corridor and northward. So snowfall totals
will be dependent on how long the airmass supports sleet instead of
transitioning to snow.
High temps today could climb above freezing south of I-70 and
possibly toward Jacksonville. Highs could delay until later this
afternoon when the warmest air aloft reaches its peak between 22z
and 02z. Northern areas should see mainly around 30 for highs. Winds
will be southerly during most of this event, which in general is not
our normal surface wind for a major ice storm due to surface temps
and dewpoints usually rising from south to north in those
situations.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 341 AM CST SUN JAN 11 2015
Tonight after midnight, on the back edge of the storm, normally
would see more snow in the forecast soundings...but even in the wake
of the system, particularly in the east and southeast, warm air in
the mid levels holding on to more sleet potential. Models also
showing the formation of a dry slot now...between the more
frontogenetic banding to the north and the remains of the system.
This may end up taking a chunk out of the QPF for after midnight
depending on the progression of the system. That same drying
starting to show in the column Monday morning as the loss of any
crystals will steer the forecast from snow and wintry mix...to
potential for freezing drizzle. Depending on the speed of the
system, as it has been getting progressively quicker, as well as the
efficacy of the dry slot...the early morning commute on Monday
morning along and south of a line from SPI to DNV may be a bit
messy.
Beyond this weekends system, forecast dries out with high pressure
dominating the weather through next week. Wave digging in over the
western half of the CONUS shearing out the energy moving along the
southern tier of the country, missing the Midwest midweek.
Temperatures at mid levels trying to level out somewhat, but cooler
than climatology continues until a more significant chance for warm
up kicks in next weekend when southerly flow kicks in again on the
back side of exiting high pressure ridge. Same southerly flow
bringing up the next chance for precip for next weekend potentially
from the southwest...and warm enough at this point to trend in some
rain.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1155 AM CST SUN JAN 11 2015
VFR ceilings of 3.5-5K feet at midday will lower to MVFR ceilings
during next few hours as mixed light precipitation develops
northward. Visibilities to also lower to MVFR during the afternoon
as light freezing rain and sleet develops along I-72 with light
snow and sleet further north at PIA and BMI. Ceilings to drop
below 1k ft during this evening with vsbys down to 1-2 miles with
mixed precipitation gradually changing to light snow along I-72
during overnight. Models show low clouds decrease from nw to se
behind cold front during Monday morning and linger longest at CMI
and DEC which currently kept them in MVFR ceilings through the
morning. South winds near 10 kts this afternoon to become lighter
this evening and then switch to the north overnight and increase
to 10-14 kts with gusts of 15-20 kts during Monday morning.
Weak 1020 mb surface low pressure over nw Gulf of Mexico to lift
ne across the southeast states through tonight while increasing
isentropic lift and moisture into central IL this afternoon and
evening. Associated short wave over MO/AR to lift nne across IL
into tonight and help develop the mixed precipitation this
afternoon and tonight, then ending Monday morning as it shifts se
of central IL. Strong 1048 mb arctic high pressure pushing into
the eastern Dakotas by 18Z/noon Monday to return tight pressure
gradient over IL with brisk northerly winds developing Monday
morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 9 AM CST Monday FOR ILZ042>057-
061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1048 AM CST SUN JAN 11 2015
.SHORT TERM...
325 AM CST
THROUGH MONDAY NIGHT...
UPPER LEVEL FLOW IS ZONAL WITH A SHORTWAVE TROUGH OVER TX. THE WAVE
WEAKENS AS IT MOVES OVER CENTRAL IL THIS EVENING. A SECOND SHORTWAVE
IS OVER THE DESERT SOUTHWEST AND IT WILL WEAKEN AS IT MOVES OVER THE
REGION MONDAY MORNING. AN UPPER LEVEL TROUGH IS STRETCHED OUT OVER
SOUTHERN CANADA AND IT/S TROUGH AXIS PASSES THROUGH THE REGION
MONDAY NIGHT.
A SURFACE HIGH IS OVER THE CENTRAL ATLANTIC COAST WHILE A WEAK
TROUGH/COLD FRONT STRETCHES FROM IOWA THROUGH SOUTHERN ONTARIO. THE
TROUGH/COLD FRONT WILL SAG SOUTH OVER THE CWA LATE THIS AFTERNOON
INTO THIS EVENING WHILE THE WEAK SURFACE LOW ASSOCIATED WITH THE
TROUGH SHIFTS NORTHEAST INTO SOUTHWEST QUEBEC. THE OTHER PLAYER IS
A LARGE HIGH PRESSURE SYSTEM CURRENTLY OVER SOUTHWEST CANADA WILL
SHIFT SOUTHEAST REACHING THE NORTHERN PLAINS TONIGHT BEFORE MOVING
OVER OUR NECK OF THE WOODS TUESDAY.
MOISTURE SURGES NORTH WITH THE FIRST SHORTWAVE TROUGH THIS AFTERNOON
AND EVENING. THERE SHOULD BE AMPLE LIFT FROM THE ON GOING WAA AND
ALONG THE TROUGH/COLD FRONT. GUIDANCE CONTINUES TO FEATURE A BAND
OF DECENT FRONTOGENESIS SINKING SOUTHEAST THROUGH THE CWA THIS
EVENING. THE NAM IS MORE EXCITED ABOUT THE FORCING THAN THE GFS.
THE NAM FEATURES A STRONG BAND STRETCHING FROM CHICAGO THROUGH LA
SALLE AT MIDNIGHT THAT QUICKLY SHIFTS SOUTHEAST TO A DETROIT MI TO
GIBSON CITY IL LINE BY 6AM MONDAY. THE GFS SHOWS A SIMILAR
PROGRESSION...JUST WEAKER. WHILE THE BAND IS IMPRESSIVE...OTHER
FACTORS SUCH AS EPV ARE MISSING SO I AM NOT EXCITED ABOUT INTENSE
BANDS OF SNOW. THAT BEING SAID...SOME ENHANCED BANDS OF SNOW MAY
FORM LEADING TO LOCALIZED HIGHER SNOW TOTALS.
PRECIP SPREADS NORTH THIS AFTERNOON WITH PRECIP FALLING SOUTH OF A
WAUKEGAN TO ROCKFORD LINE BY 6PM CST. EXPECTING SNOW FOR ALL AREAS
EXCEPT THOSE SOUTH OF A PONTIAC IL TO RENSSELAER INDIANA LINE.
SOUNDINGS SOUTH OF THIS LINE FEATURE PARTIAL MELTING ALOFT THAT MAY
LEAD TO SLEET MIXED WITH SNOW. NOT SURE HOW LONG SLEET OR A MIX OF
SLEET AND SNOW WILL FALL SOUTH OF THIS LINE AS COOLING MAY HELP THE
PRECIP TURN OVER TO ALL SNOW SOONER THAN FORECAST. IF THAT
HAPPENS...SNOW AMOUNTS WILL BE HIGHER THAN CURRENTLY FORECAST.
FOR THE AREAS NORTH OF THE PONTIAC TO RENSSELAER LINE...STEADY LIGHT
TO MODERATE SNOW IS EXPECTED THROUGH THE EVENING. A FEW BANDS OF
MODERATE TO POSSIBLY HEAVY SNOW MAY FORM ALONG AND SOUTH OF A
CHICAGO TO LA SALLE LINE AFTER MIDNIGHT. EXPECTING ALL SNOW ACROSS
THE CWA AFTER MIDNIGHT AND THE SNOW SLOWLY EXITS TO THE SOUTHEAST
THROUGH MID MONDAY MORNING.
HAVE LOWER STORM TOTAL SNOWFALL AMOUNTS THAN THE PREVIOUS FORECAST
DUE TO LESS CONFIDENCE IN BANDS OF HEAVIER SNOW AND HIGHER
CONFIDENCE IN SLEET MIXED WITH SNOW IN THE SOUTHERN CWA. EXPECTING
1 TO 2 INCHES ALONG AND SOUTH OF A OHARE TO AMBOY LINE WITH 1 TO
3...MAYBE LOCALIZED 4 INCHES SOUTH OF A GARY INDIANA TO LA SALLE
LINE.
WINDS TURN NORTH MONDAY LEADING TO THE POSSIBILITY OF LAKE EFFECT
SNOW OVER NW INDIANA MONDAY. STILL NOT OVERLY IMPRESSED WITH THE
LAKE EFFECT SET UP AS WELL WITH VERY MARGINAL DELTA T/S...DRY
FORECAST SOUNDINGS...AND SOME ICE OVER THE LAKE. AS SUCH CAPPED
POPS IN THE CHANCE RANGE. WINDS VEER TO NORTHEAST MONDAY EVENING
AND THE BAND OF SNOW SHIFTS WEST TO OVER ILLINOIS.
TEMPS MONDAY WILL VARY FROM THE MID TEENS OVER NORTH CENTRAL IL TO
THE MID 20S OVER NW INDIANA. LOWS WILL VARY FROM AROUND +10
DOWNTOWN TO 0 TO +5 IN OUTLYING AREAS. SOME ISOLATED LOCATIONS MAY
DIP BELOW ZERO.
JEE
&&
.LONG TERM...
325 AM CST
TUESDAY THROUGH SATURDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE CONUS TUESDAY WITH TROUGH
AXES/SHORTWAVES MOVING THROUGH THE REGION TUESDAY...WEDNESDAY AND
THURSDAY. THE SURFACE HIGH SITS OVER THE CWA TUESDAY AND SLOWLY
SINKS SOUTH WEDNESDAY. A CLIPPER SYSTEM PASSES TO OUR NORTH
WEDNESDAY NIGHT INTO THURSDAY WITH ANOTHER SURFACE HIGH MOVING OVER
THE REGION LATE IN THE WEEK.
LOOKING AT A DRY REST OF THE WEEK WITH HIGH TEMPS IN THE TEENS
TUESDAY AND WEDNESDAY. THEN WE GET INTO A WARMING TREND WITH AT OR
SLIGHTLY ABOVE FREEZING HIGH TEMPS BY THE END OF THE WEEK. THE ONLY
REALLY COLD NIGHT IS TUESDAY NIGHT WITH LOWS BETWEEN 0 AND -10 AWAY
FROM THE CITY BUT LIGHT WINDS WILL KEEP WIND CHILLS WARMER THAN
-20.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SNOW SPREADING NORTH/MOVING IN LATE THIS AFTERNOON/EARLY THIS
EVENING...ENDING OVERNIGHT.
* IFR VSBY WITH PERIODIC LIFR POSSIBLE IN VARIABLE BANDS OF SNOW.
CIGS LOWER TO MVFR/IFR THIS EVENING.
* SOUTH TO SOUTHWEST WINDS TURN NORTHWEST EARLY TONIGHT AND
INCREASE OUT OF THE NORTH MONDAY.
ED F
//DISCUSSION...UPDATED 12Z...
VFR CONDITIONS WILL CONTINUE THROUGH THE DAY BEFORE DETERIORATING
LATE THIS AFTERNOON AND THIS EVENING AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE REGION. SNOW WILL SPREAD NORTHWARD ACROSS THE
TERMINALS LATE THIS AFTERNOON THROUGH THE EVENING...THEN COME TO
AN END OVERNIGHT. RFD WILL LIKELY REMAIN JUST NORTH OF THE SNOW
BAND BUT WILL CONTINUE WITH A PROB30 MENTION FOR NOW.
OTHERWISE...SNOW MAY FALL IN SEVERAL BANDS WHICH SUGGESTS THAT
THERE MAY BE A HIGH DEGREE OF VARIABILITY IN CIGS AND ESPECIALLY
VSBY. SNOW WILL PROBABLY FALL CONTINUOUSLY FOR THE MOST PART BUT
INTENSITY MAY FLUCTUATE QUITE A BIT. HAVE GOOD CONFIDENCE IN THE
OVERALL TIME WINDOW FOR SNOWFALL BUT THE DETAILS SUCH AS
IDENTIFYING THE BEST WINDOW FOR LOWEST VSBY REMAINS A
CHALLENGE...TANKS TO THE TRANSIENT NATURE OF THE EXPECTED
BANDS. SOUTH TO SOUTHWEST WINDS WILL PREVAIL INTO THE EVENING AS
WELL BEFORE TURNING WEST THEN NORTHWEST TONIGHT BEHIND A FRONT.
MVFR CIGS MAY END UP PREVAILING INTO MONDAY MORNING BUT THERE IS
ALSO SUPPORT FOR LESS MVFR COVERAGE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN SNOW OCCURRING THIS EVENING. HIGH CONFIDENCE
IN START TIME. MEDIUM-HIGH CONFIDENCE IN END TIME.
* HIGH CONFIDENCE IN IFR VSBY OCCURRING IN SNOW WITH MEDIUM
CONFIDENCE IN LIFR VSBY OCCURRING INTERMITTENTLY. LOW CONFIDENCE
IN DURATION OF LIFR VSBY. HIGH CONFIDENCE IN CIG TRENDS THROUGH
THE EVENING. MEDIUM CONFIDENCE IN CIG TRENDS OVERNIGHT.
* HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS POSSIBLE. A CHANCE OF LIGHT SNOW SHOWERS. NORTH
WINDS.
TUESDAY...MVFR CIGS POSSIBLE. NORTHEAST-EAST WINDS.
WEDNESDAY THROUGH SATURDAY...PRIMARILY VFR. SOUTHWEST TO WEST
WINDS.
MDB
&&
.MARINE...
254 AM CST
WEAK LOW PRESSURE IS MOVING ACROSS UPPER MICHIGAN THIS MORNING WITH
A TROUGH AXIS/COLD FRONT TRAILING IT TO THE SOUTHWEST. STRONG HIGH
PRESSURE OVER THE CAROLINA COAST WILL SHIFT OFFSHORE THROUGH THE DAY
ALLOWING THE SURFACE TROUGH TO SAG SOUTHEASTWARD INTO TONIGHT. THE
FAIRLY STRONG PRESSURE GRADIENT ACROSS LAKE MICHIGAN EARLY THIS
MORNING CONTINUES TO GENERATE STEADY WINDS BUT SPEEDS WILL STEADILY
DIMINISH THROUGH THE MORNING AS THE PRESSURE GRADIENT WEAKENS. WINDS
WILL SHIFT TO THE NORTHWEST TONIGHT AS THE FRONT PASSES WITH A
FURTHER SHIFT TO THE NORTH OCCURRING MONDAY MORNING. STRONG HIGH
PRESSURE ACROSS CENTRAL CANADA THIS MORNING WILL STRENGTHEN AS IT
MOVES SOUTHEAST INTO THE EASTERN DAKOTAS OVERNIGHT. AS A
RESULT...SPEEDS WILL PICK UP WITH GUSTS TO AROUND 25 KT LIKELY WITH
SOME CLOSER TO 30 KT POSSIBLE AT TIMES DURING THE DAY MONDAY BEFORE
WINDS TURN MORE TO THE NORTHEAST AND EASE MONDAY EVENING/NIGHT AS
THE HIGH SPREADS ACROSS THE LAKES.
THE HIGH WILL SHIFT SOUTH OF THE GREAT LAKES LATER WEDNESDAY. A
SERIES OF LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK ACROSS SOUTHERN
CANADA AND THE NORTHERN TIER OF STATES INTO LATE WEEK LEADING TO
PERIODIC WIND SHIFTS AND INCREASES IN SPEED.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1047 AM CST Sun Jan 11 2015
.UPDATE...
ISSUED AT 1045 AM CST SUN JAN 11 2015
Will continue the winter weather advisory from this afternoon
until 9 am Monday morning from Lincoln and Rantoul south for a
wintery mix of precipitation. Have nudged temperatures up a bit
today as current mercury levels running 1-2 degrees warmer with
most areas in the lower 30s (ranging from 29F at Galesburg to 36
at Mount Carmel airport). But low dewpoints in the mid teens to
lower 20s with wet bulb zero readings in the mid to upper 20s will
cause temps to slip back 1-2F as precipitation moves in from the
south during this afternoon. Radar shows a narrow band of light
precipitation lifting north of I-72 but most of this appears to be
virga with dry low levels. Litchfield had a 1-2 hour period of
light sleet with this band earlier this morning. Main area of
precipitation is lifting northward into southern IL (south of
I-64) and should overspread central/se IL during the afternoon.
Have brought in a mix of light freezing rain and light rain into
southeast IL southeast of I-70 this afternoon which continues into
this evening and this could lower their ice accumulations south of
I-70. Light snow and sleet expected to develop north of winter wx
advisory area in frontogenetic band setting up over the IL river
valley later this afternoon, with half to 1 inch of snow by dusk.
Mixture of light freezing rain and sleet expected over heart of
central IL especially from Lincoln south to I-70 with ice
accumulations generally less than a tenth of an inch through dusk.
More snow and ice acculuations expected tonight with 1-2 inches north
and one to two tenths inch ice central sections and less than a
tenth inch of ice southeast of I-70 near highway 50 in southern 3
counties.
&&
.SHORT TERM...(Today)
ISSUED AT 341 AM CST SUN JAN 11 2015
Warm air surging north ahead of the next cold front will ride up and
over the cold dome of air in place across central IL. 40kt of
isentropic lift along the 300K surface will help the layer of clouds
around 6K FT deepen with time as additional moisture arrives. Light
freezing rain or sleet will advance northward this morning, possibly
reaching our southern counties a little before Noon. At the same
time, a frontogenetical circulation across our northern counties
will work to produce light snow/sleet north of a line from
Bloomington to Havana, and especially from Peoria and north. The
models have shown this band of snow over the past several runs. So
it is possible we could have a region in the central portion of our
forecast area (generally along I-72) remain dry while snow falls
north and freezing rain/sleet falls to the south. Eventually we
should see freezing rain/sleet overspread our central counties up to
I-72 and continue into the evening. 00z/NAM soundings definitely
show a warm bias over the cooler GFS and ECMWF. We trended slightly
warmer with surface temps across the southerly half of the area as a
result, and pushed chances of freezing rain farther north as well.
In light of the northward trend for icing from freezing rain, in
conjunction with snow/sleet later in the event, we expanded the
advisory area northward another row of counties to now include
Champaign and Lincoln. Icing potential from freezing rain could
climb between one and two tenths of an inch toward the I-70
corridor. There is low potential for isolated areas to see a quarter
inch of ice, which is our trigger for an ice storm warning. If the
warmer trend is correct, our southern counties along highway 50
could become all rain later this afternoon and early evening, which
would reduce ice totals as you headed south of I-70.
The 00z/NAM is also indicating an extended period of sleet will be
possible toward I-72. If that developed, we could see 0.5" of sleet,
which is one trigger for a winter storm warning. At this point, we
do not have high enough confidence of widespread areas receiving
0.25" of ice nor 0.5" of sleet to warrant an upgrade to a winter
storm warning. We will keep the headlines as an advisory. QPF
amounts in general do not seem to support ice and sleet
accumulations that high from this event.
Even models generally lower on QPF, there is evidence in the GFS and
NAM of banded precipitation, which could create large variations in
snow/sleet/ice amounts over short distances. There is a 100mb layer
of the Fn convergent portion of frontogenesis across our forecast
area, with negative EPV just above that layer to allow for CSI-type
banding. Pinpointing those bands is difficult even this close to the
event. As hourly HRRR and RAP model updates come in and we compare
to satellite and radar, we will have a better chance to do short
term updates on snow/sleet/ice amounts where bands appear more
likely.
For now, we will stick with snow totals north of I-72 in the 1-2"
range, with ice totals of in the 0.1-0.2" range with the highest
amounts along the I-70 corridor. Sleet totals would reduce snow
amounts along the I-72 corridor and northward. So snowfall totals
will be dependent on how long the airmass supports sleet instead of
transitioning to snow.
High temps today could climb above freezing south of I-70 and
possibly toward Jacksonville. Highs could delay until later this
afternoon when the warmest air aloft reaches its peak between 22z
and 02z. Northern areas should see mainly around 30 for highs. Winds
will be southerly during most of this event, which in general is not
our normal surface wind for a major ice storm due to surface temps
and dewpoints usually rising from south to north in those
situations.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 341 AM CST SUN JAN 11 2015
Tonight after midnight, on the back edge of the storm, normally
would see more snow in the forecast soundings...but even in the wake
of the system, particularly in the east and southeast, warm air in
the mid levels holding on to more sleet potential. Models also
showing the formation of a dry slot now...between the more
frontogenetic banding to the north and the remains of the system.
This may end up taking a chunk out of the QPF for after midnight
depending on the progression of the system. That same drying
starting to show in the column Monday morning as the loss of any
crystals will steer the forecast from snow and wintry mix...to
potential for freezing drizzle. Depending on the speed of the
system, as it has been getting progressively quicker, as well as the
efficacy of the dry slot...the early morning commute on Monday
morning along and south of a line from SPI to DNV may be a bit
messy.
Beyond this weekends system, forecast dries out with high pressure
dominating the weather through next week. Wave digging in over the
western half of the CONUS shearing out the energy moving along the
southern tier of the country, missing the Midwest midweek.
Temperatures at mid levels trying to level out somewhat, but cooler
than climatology continues until a more significant chance for warm
up kicks in next weekend when southerly flow kicks in again on the
back side of exiting high pressure ridge. Same southerly flow
bringing up the next chance for precip for next weekend potentially
from the southwest...and warm enough at this point to trend in some
rain.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 600 AM CST SUN JAN 11 2015
Timing of precip and precip type the main forecast concerns this
period. Next wave of low pressure will start to affect the area this
morning. The current VFR ceilings at 5-6K ft will thicken and
lower during the morning. Some light snow, sleet and freezing rain
are expected to develop across our southern TAF sites (KSPI, KDEC
and KCMI) in the 17z-19z time frame. DEC, SPI, and CMI could
transition to all freezing rain toward mid-afternoon as the warm
layer aloft increases temp to +3C. The northern TAF sites (KBMI
and KPIA) should remain a bit colder, seeing more of a light snow
and sleet mixture develop overhead between 18z- 20z. Once the
precip begins it will be just a matter of an hour or two before we
see cigs drop from low VFR to MVFR, and then IFR/LIFR after
21-22z. Forecast soundings suggest the higher probability for
freezing rain would be from SPI to DEC to near CMI with more of a
sleet and light snow mix further north at BMI, with mostly light
snow expected at PIA. Surface temperatures across our southern TAF
sites will warm to near the freezing mark but in all probability,
should begin to cool off by a degree or two after the precip
begins.
Look for the light wintry mix to continue on and off tonight with a
transition over to light snow as the night wears on due to a cold
front pushing acrs the area and cooling temps off just enough in
the lower levels of the atmosphere for the changeover to occur.
Surface winds will remain out of the south today with speeds of 8
to 12 kts. As the cold front approaches this evening, winds will
start to veer more into a westerly direction. Once the front
passes across the area between 04z-08z, winds will become N-NW and
remain generally less than 10kt through 12z/6am Monday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 9 AM CST Monday FOR ILZ042>057-
061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
816 AM CST SUN JAN 11 2015
.SHORT TERM...
325 AM CST
THROUGH MONDAY NIGHT...
UPPER LEVEL FLOW IS ZONAL WITH A SHORTWAVE TROUGH OVER TX. THE WAVE
WEAKENS AS IT MOVES OVER CENTRAL IL THIS EVENING. A SECOND SHORTWAVE
IS OVER THE DESERT SOUTHWEST AND IT WILL WEAKEN AS IT MOVES OVER THE
REGION MONDAY MORNING. AN UPPER LEVEL TROUGH IS STRETCHED OUT OVER
SOUTHERN CANADA AND IT/S TROUGH AXIS PASSES THROUGH THE REGION
MONDAY NIGHT.
A SURFACE HIGH IS OVER THE CENTRAL ATLANTIC COAST WHILE A WEAK
TROUGH/COLD FRONT STRETCHES FROM IOWA THROUGH SOUTHERN ONTARIO. THE
TROUGH/COLD FRONT WILL SAG SOUTH OVER THE CWA LATE THIS AFTERNOON
INTO THIS EVENING WHILE THE WEAK SURFACE LOW ASSOCIATED WITH THE
TROUGH SHIFTS NORTHEAST INTO SOUTHWEST QUEBEC. THE OTHER PLAYER IS
A LARGE HIGH PRESSURE SYSTEM CURRENTLY OVER SOUTHWEST CANADA WILL
SHIFT SOUTHEAST REACHING THE NORTHERN PLAINS TONIGHT BEFORE MOVING
OVER OUR NECK OF THE WOODS TUESDAY.
MOISTURE SURGES NORTH WITH THE FIRST SHORTWAVE TROUGH THIS AFTERNOON
AND EVENING. THERE SHOULD BE AMPLE LIFT FROM THE ON GOING WAA AND
ALONG THE TROUGH/COLD FRONT. GUIDANCE CONTINUES TO FEATURE A BAND
OF DECENT FRONTOGENESIS SINKING SOUTHEAST THROUGH THE CWA THIS
EVENING. THE NAM IS MORE EXCITED ABOUT THE FORCING THAN THE GFS.
THE NAM FEATURES A STRONG BAND STRETCHING FROM CHICAGO THROUGH LA
SALLE AT MIDNIGHT THAT QUICKLY SHIFTS SOUTHEAST TO A DETROIT MI TO
GIBSON CITY IL LINE BY 6AM MONDAY. THE GFS SHOWS A SIMILAR
PROGRESSION...JUST WEAKER. WHILE THE BAND IS IMPRESSIVE...OTHER
FACTORS SUCH AS EPV ARE MISSING SO I AM NOT EXCITED ABOUT INTENSE
BANDS OF SNOW. THAT BEING SAID...SOME ENHANCED BANDS OF SNOW MAY
FORM LEADING TO LOCALIZED HIGHER SNOW TOTALS.
PRECIP SPREADS NORTH THIS AFTERNOON WITH PRECIP FALLING SOUTH OF A
WAUKEGAN TO ROCKFORD LINE BY 6PM CST. EXPECTING SNOW FOR ALL AREAS
EXCEPT THOSE SOUTH OF A PONTIAC IL TO RENSSELAER INDIANA LINE.
SOUNDINGS SOUTH OF THIS LINE FEATURE PARTIAL MELTING ALOFT THAT MAY
LEAD TO SLEET MIXED WITH SNOW. NOT SURE HOW LONG SLEET OR A MIX OF
SLEET AND SNOW WILL FALL SOUTH OF THIS LINE AS COOLING MAY HELP THE
PRECIP TURN OVER TO ALL SNOW SOONER THAN FORECAST. IF THAT
HAPPENS...SNOW AMOUNTS WILL BE HIGHER THAN CURRENTLY FORECAST.
FOR THE AREAS NORTH OF THE PONTIAC TO RENSSELAER LINE...STEADY LIGHT
TO MODERATE SNOW IS EXPECTED THROUGH THE EVENING. A FEW BANDS OF
MODERATE TO POSSIBLY HEAVY SNOW MAY FORM ALONG AND SOUTH OF A
CHICAGO TO LA SALLE LINE AFTER MIDNIGHT. EXPECTING ALL SNOW ACROSS
THE CWA AFTER MIDNIGHT AND THE SNOW SLOWLY EXITS TO THE SOUTHEAST
THROUGH MID MONDAY MORNING.
HAVE LOWER STORM TOTAL SNOWFALL AMOUNTS THAN THE PREVIOUS FORECAST
DUE TO LESS CONFIDENCE IN BANDS OF HEAVIER SNOW AND HIGHER
CONFIDENCE IN SLEET MIXED WITH SNOW IN THE SOUTHERN CWA. EXPECTING
1 TO 2 INCHES ALONG AND SOUTH OF A OHARE TO AMBOY LINE WITH 1 TO
3...MAYBE LOCALIZED 4 INCHES SOUTH OF A GARY INDIANA TO LA SALLE
LINE.
WINDS TURN NORTH MONDAY LEADING TO THE POSSIBILITY OF LAKE EFFECT
SNOW OVER NW INDIANA MONDAY. STILL NOT OVERLY IMPRESSED WITH THE
LAKE EFFECT SET UP AS WELL WITH VERY MARGINAL DELTA T/S...DRY
FORECAST SOUNDINGS...AND SOME ICE OVER THE LAKE. AS SUCH CAPPED
POPS IN THE CHANCE RANGE. WINDS VEER TO NORTHEAST MONDAY EVENING
AND THE BAND OF SNOW SHIFTS WEST TO OVER ILLINOIS.
TEMPS MONDAY WILL VARY FROM THE MID TEENS OVER NORTH CENTRAL IL TO
THE MID 20S OVER NW INDIANA. LOWS WILL VARY FROM AROUND +10
DOWNTOWN TO 0 TO +5 IN OUTLYING AREAS. SOME ISOLATED LOCATIONS MAY
DIP BELOW ZERO.
JEE
&&
.LONG TERM...
325 AM CST
TUESDAY THROUGH SATURDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE CONUS TUESDAY WITH TROUGH
AXES/SHORTWAVES MOVING THROUGH THE REGION TUESDAY...WEDNESDAY AND
THURSDAY. THE SURFACE HIGH SITS OVER THE CWA TUESDAY AND SLOWLY
SINKS SOUTH WEDNESDAY. A CLIPPER SYSTEM PASSES TO OUR NORTH
WEDNESDAY NIGHT INTO THURSDAY WITH ANOTHER SURFACE HIGH MOVING OVER
THE REGION LATE IN THE WEEK.
LOOKING AT A DRY REST OF THE WEEK WITH HIGH TEMPS IN THE TEENS
TUESDAY AND WEDNESDAY. THEN WE GET INTO A WARMING TREND WITH AT OR
SLIGHTLY ABOVE FREEZING HIGH TEMPS BY THE END OF THE WEEK. THE ONLY
REALLY COLD NIGHT IS TUESDAY NIGHT WITH LOWS BETWEEN 0 AND -10 AWAY
FROM THE CITY BUT LIGHT WINDS WILL KEEP WIND CHILLS WARMER THAN
-20.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SNOW SPREADING NORTH/MOVING IN LATE THIS AFTERNOON/EARLY THIS
EVENING...ENDING OVERNIGHT.
* IFR VSBY WITH PERIODIC LIFR POSSIBLE IN VARIABLE BANDS OF SNOW.
CIGS LOWER TO MVFR/IFR THIS EVENING.
* SOUTH TO SOUTHWEST WINDS TURN NORTHWEST EARLY TONIGHT AND
INCREASE OUT OF THE NORTH MONDAY.
ED F
//DISCUSSION...UPDATED 12Z...
VFR CONDITIONS WILL CONTINUE THROUGH THE DAY BEFORE DETERIORATING
LATE THIS AFTERNOON AND THIS EVENING AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE REGION. SNOW WILL SPREAD NORTHWARD ACROSS THE
TERMINALS LATE THIS AFTERNOON THROUGH THE EVENING...THEN COME TO
AN END OVERNIGHT. RFD WILL LIKELY REMAIN JUST NORTH OF THE SNOW
BAND BUT WILL CONTINUE WITH A PROB30 MENTION FOR NOW.
OTHERWISE...SNOW MAY FALL IN SEVERAL BANDS WHICH SUGGESTS THAT
THERE MAY BE A HIGH DEGREE OF VARIABILITY IN CIGS AND ESPECIALLY
VSBY. SNOW WILL PROBABLY FALL CONTINUOUSLY FOR THE MOST PART BUT
INTENSITY MAY FLUCTUATE QUITE A BIT. HAVE GOOD CONFIDENCE IN THE
OVERALL TIME WINDOW FOR SNOWFALL BUT THE DETAILS SUCH AS
IDENTIFYING THE BEST WINDOW FOR LOWEST VSBY REMAINS A
CHALLENGE...TANKS TO THE TRANSIENT NATURE OF THE EXPECTED
BANDS. SOUTH TO SOUTHWEST WINDS WILL PREVAIL INTO THE EVENING AS
WELL BEFORE TURNING WEST THEN NORTHWEST TONIGHT BEHIND A FRONT.
MVFR CIGS MAY END UP PREVAILING INTO MONDAY MORNING BUT THERE IS
ALSO SUPPORT FOR LESS MVFR COVERAGE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN SNOW OCCURRING THIS EVENING. HIGH CONFIDENCE
IN START TIME. MEDIUM-HIGH CONFIDENCE IN END TIME.
* HIGH CONFIDENCE IN IFR VSBY OCCURRING IN SNOW WITH MEDIUM
CONFIDENCE IN LIFR VSBY OCCURRING INTERMITTENTLY. LOW CONFIDENCE
IN DURATION OF LIFR VSBY. HIGH CONFIDENCE IN CIG TRENDS THROUGH
THE EVENING. MEDIUM CONFIDENCE IN CIG TRENDS OVERNIGHT.
* HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS POSSIBLE. A CHANCE OF LIGHT SNOW SHOWERS. NORTH
WINDS.
TUESDAY...MVFR CIGS POSSIBLE. NORTHEAST-EAST WINDS.
WEDNESDAY THROUGH SATURDAY...PRIMARILY VFR. SOUTHWEST TO WEST
WINDS.
MDB
&&
.MARINE...
254 AM CST
WEAK LOW PRESSURE IS MOVING ACROSS UPPER MICHIGAN THIS MORNING WITH
A TROUGH AXIS/COLD FRONT TRAILING IT TO THE SOUTHWEST. STRONG HIGH
PRESSURE OVER THE CAROLINA COAST WILL SHIFT OFFSHORE THROUGH THE DAY
ALLOWING THE SURFACE TROUGH TO SAG SOUTHEASTWARD INTO TONIGHT. THE
FAIRLY STRONG PRESSURE GRADIENT ACROSS LAKE MICHIGAN EARLY THIS
MORNING CONTINUES TO GENERATE STEADY WINDS BUT SPEEDS WILL STEADILY
DIMINISH THROUGH THE MORNING AS THE PRESSURE GRADIENT WEAKENS. WINDS
WILL SHIFT TO THE NORTHWEST TONIGHT AS THE FRONT PASSES WITH A
FURTHER SHIFT TO THE NORTH OCCURRING MONDAY MORNING. STRONG HIGH
PRESSURE ACROSS CENTRAL CANADA THIS MORNING WILL STRENGTHEN AS IT
MOVES SOUTHEAST INTO THE EASTERN DAKOTAS OVERNIGHT. AS A
RESULT...SPEEDS WILL PICK UP WITH GUSTS TO AROUND 25 KT LIKELY WITH
SOME CLOSER TO 30 KT POSSIBLE AT TIMES DURING THE DAY MONDAY BEFORE
WINDS TURN MORE TO THE NORTHEAST AND EASE MONDAY EVENING/NIGHT AS
THE HIGH SPREADS ACROSS THE LAKES.
THE HIGH WILL SHIFT SOUTH OF THE GREAT LAKES LATER WEDNESDAY. A
SERIES OF LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK ACROSS SOUTHERN
CANADA AND THE NORTHERN TIER OF STATES INTO LATE WEEK LEADING TO
PERIODIC WIND SHIFTS AND INCREASES IN SPEED.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
605 AM CST Sun Jan 11 2015
.SHORT TERM...(Today)
ISSUED AT 341 AM CST SUN JAN 11 2015
Warm air surging north ahead of the next cold front will ride up and
over the cold dome of air in place across central IL. 40kt of
isentropic lift along the 300K surface will help the layer of clouds
around 6K FT deepen with time as additional moisture arrives. Light
freezing rain or sleet will advance northward this morning, possibly
reaching our southern counties a little before Noon. At the same
time, a frontogenetical circulation across our northern counties
will work to produce light snow/sleet north of a line from
Bloomington to Havana, and especially from Peoria and north. The
models have shown this band of snow over the past several runs. So
it is possible we could have a region in the central portion of our
forecast area (generally along I-72) remain dry while snow falls
north and freezing rain/sleet falls to the south. Eventually we
should see freezing rain/sleet overspread our central counties up to
I-72 and continue into the evening. 00z/NAM soundings definitely
show a warm bias over the cooler GFS and ECMWF. We trended slightly
warmer with surface temps across the southerly half of the area as a
result, and pushed chances of freezing rain farther north as well.
In light of the northward trend for icing from freezing rain, in
conjunction with snow/sleet later in the event, we expanded the
advisory area northward another row of counties to now include
Champaign and Lincoln. Icing potential from freezing rain could
climb between one and two tenths of an inch toward the I-70
corridor. There is low potential for isolated areas to see a quarter
inch of ice, which is our trigger for an ice storm warning. If the
warmer trend is correct, our southern counties along highway 50
could become all rain later this afternoon and early evening, which
would reduce ice totals as you headed south of I-70.
The 00z/NAM is also indicating an extended period of sleet will be
possible toward I-72. If that developed, we could see 0.5" of sleet,
which is one trigger for a winter storm warning. At this point, we
do not have high enough confidence of widespread areas receiving
0.25" of ice nor 0.5" of sleet to warrant an upgrade to a winter
storm warning. We will keep the headlines as an advisory. QPF
amounts in general do not seem to support ice and sleet
accumulations that high from this event.
Even models generally lower on QPF, there is evidence in the GFS and
NAM of banded precipitation, which could create large variations in
snow/sleet/ice amounts over short distances. There is a 100mb layer
of the Fn convergent portion of frontogenesis across our forecast
area, with negative EPV just above that layer to allow for CSI-type
banding. Pinpointing those bands is difficult even this close to the
event. As hourly HRRR and RAP model updates come in and we compare
to satellite and radar, we will have a better chance to do short
term updates on snow/sleet/ice amounts where bands appear more
likely.
For now, we will stick with snow totals north of I-72 in the 1-2"
range, with ice totals of in the 0.1-0.2" range with the highest
amounts along the I-70 corridor. Sleet totals would reduce snow
amounts along the I-72 corridor and northward. So snowfall totals
will be dependent on how long the airmass supports sleet instead of
transitioning to snow.
High temps today could climb above freezing south of I-70 and
possibly toward Jacksonville. Highs could delay until later this
afternoon when the warmest air aloft reaches its peak between 22z
and 02z. Northern areas should see mainly around 30 for highs. Winds
will be southerly during most of this event, which in general is not
our normal surface wind for a major ice storm due to surface temps
and dewpoints usually rising from south to north in those
situations.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 341 AM CST SUN JAN 11 2015
Tonight after midnight, on the back edge of the storm, normally
would see more snow in the forecast soundings...but even in the wake
of the system, particularly in the east and southeast, warm air in
the mid levels holding on to more sleet potential. Models also
showing the formation of a dry slot now...between the more
frontogenetic banding to the north and the remains of the system.
This may end up taking a chunk out of the QPF for after midnight
depending on the progression of the system. That same drying
starting to show in the column Monday morning as the loss of any
crystals will steer the forecast from snow and wintry mix...to
potential for freezing drizzle. Depending on the speed of the
system, as it has been getting progressively quicker, as well as the
efficacy of the dry slot...the early morning commute on Monday
morning along and south of a line from SPI to DNV may be a bit
messy.
Beyond this weekends system, forecast dries out with high pressure
dominating the weather through next week. Wave digging in over the
western half of the CONUS shearing out the energy moving along the
southern tier of the country, missing the Midwest midweek.
Temperatures at mid levels trying to level out somewhat, but cooler
than climatology continues until a more significant chance for warm
up kicks in next weekend when southerly flow kicks in again on the
back side of exiting high pressure ridge. Same southerly flow
bringing up the next chance for precip for next weekend potentially
from the southwest...and warm enough at this point to trend in some
rain.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 600 AM CST SUN JAN 11 2015
Timing of precip and precip type the main forecast concerns this
period. Next wave of low pressure will start to affect the area this
morning. The current VFR ceilings at 5-6K ft will thicken and
lower during the morning. Some light snow, sleet and freezing rain
are expected to develop across our southern TAF sites (KSPI, KDEC
and KCMI) in the 17z-19z time frame. DEC, SPI, and CMI could
transition to all freezing rain toward mid-afternoon as the warm
layer aloft increases temp to +3C. The northern TAF sites (KBMI
and KPIA) should remain a bit colder, seeing more of a light snow
and sleet mixture develop overhead between 18z- 20z. Once the
precip begins it will be just a matter of an hour or two before we
see cigs drop from low VFR to MVFR, and then IFR/LIFR after
21-22z. Forecast soundings suggest the higher probability for
freezing rain would be from SPI to DEC to near CMI with more of a
sleet and light snow mix further north at BMI, with mostly light
snow expected at PIA. Surface temperatures across our southern TAF
sites will warm to near the freezing mark but in all probability,
should begin to cool off by a degree or two after the precip
begins.
Look for the light wintry mix to continue on and off tonight with a
transition over to light snow as the night wears on due to a cold
front pushing acrs the area and cooling temps off just enough in
the lower levels of the atmosphere for the changeover to occur.
Surface winds will remain out of the south today with speeds of 8
to 12 kts. As the cold front approaches this evening, winds will
start to veer more into a westerly direction. Once the front
passes across the area between 04z-08z, winds will become N-NW and
remain generally less than 10kt through 12z/6am Monday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from Noon today to 9 AM CST Monday FOR
ILZ042>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
550 AM CST SUN JAN 11 2015
.SHORT TERM...
325 AM CST
THROUGH MONDAY NIGHT...
UPPER LEVEL FLOW IS ZONAL WITH A SHORTWAVE TROUGH OVER TX. THE WAVE
WEAKENS AS IT MOVES OVER CENTRAL IL THIS EVENING. A SECOND SHORTWAVE
IS OVER THE DESERT SOUTHWEST AND IT WILL WEAKEN AS IT MOVES OVER THE
REGION MONDAY MORNING. AN UPPER LEVEL TROUGH IS STRETCHED OUT OVER
SOUTHERN CANADA AND IT/S TROUGH AXIS PASSES THROUGH THE REGION
MONDAY NIGHT.
A SURFACE HIGH IS OVER THE CENTRAL ATLANTIC COAST WHILE A WEAK
TROUGH/COLD FRONT STRETCHES FROM IOWA THROUGH SOUTHERN ONTARIO. THE
TROUGH/COLD FRONT WILL SAG SOUTH OVER THE CWA LATE THIS AFTERNOON
INTO THIS EVENING WHILE THE WEAK SURFACE LOW ASSOCIATED WITH THE
TROUGH SHIFTS NORTHEAST INTO SOUTHWEST QUEBEC. THE OTHER PLAYER IS
A LARGE HIGH PRESSURE SYSTEM CURRENTLY OVER SOUTHWEST CANADA WILL
SHIFT SOUTHEAST REACHING THE NORTHERN PLAINS TONIGHT BEFORE MOVING
OVER OUR NECK OF THE WOODS TUESDAY.
MOISTURE SURGES NORTH WITH THE FIRST SHORTWAVE TROUGH THIS AFTERNOON
AND EVENING. THERE SHOULD BE AMPLE LIFT FROM THE ON GOING WAA AND
ALONG THE TROUGH/COLD FRONT. GUIDANCE CONTINUES TO FEATURE A BAND
OF DECENT FRONTOGENESIS SINKING SOUTHEAST THROUGH THE CWA THIS
EVENING. THE NAM IS MORE EXCITED ABOUT THE FORCING THAN THE GFS.
THE NAM FEATURES A STRONG BAND STRETCHING FROM CHICAGO THROUGH LA
SALLE AT MIDNIGHT THAT QUICKLY SHIFTS SOUTHEAST TO A DETROIT MI TO
GIBSON CITY IL LINE BY 6AM MONDAY. THE GFS SHOWS A SIMILAR
PROGRESSION...JUST WEAKER. WHILE THE BAND IS IMPRESSIVE...OTHER
FACTORS SUCH AS EPV ARE MISSING SO I AM NOT EXCITED ABOUT INTENSE
BANDS OF SNOW. THAT BEING SAID...SOME ENHANCED BANDS OF SNOW MAY
FORM LEADING TO LOCALIZED HIGHER SNOW TOTALS.
PRECIP SPREADS NORTH THIS AFTERNOON WITH PRECIP FALLING SOUTH OF A
WAUKEGAN TO ROCKFORD LINE BY 6PM CST. EXPECTING SNOW FOR ALL AREAS
EXCEPT THOSE SOUTH OF A PONTIAC IL TO RENSSELAER INDIANA LINE.
SOUNDINGS SOUTH OF THIS LINE FEATURE PARTIAL MELTING ALOFT THAT MAY
LEAD TO SLEET MIXED WITH SNOW. NOT SURE HOW LONG SLEET OR A MIX OF
SLEET AND SNOW WILL FALL SOUTH OF THIS LINE AS COOLING MAY HELP THE
PRECIP TURN OVER TO ALL SNOW SOONER THAN FORECAST. IF THAT
HAPPENS...SNOW AMOUNTS WILL BE HIGHER THAN CURRENTLY FORECAST.
FOR THE AREAS NORTH OF THE PONTIAC TO RENSSELAER LINE...STEADY LIGHT
TO MODERATE SNOW IS EXPECTED THROUGH THE EVENING. A FEW BANDS OF
MODERATE TO POSSIBLY HEAVY SNOW MAY FORM ALONG AND SOUTH OF A
CHICAGO TO LA SALLE LINE AFTER MIDNIGHT. EXPECTING ALL SNOW ACROSS
THE CWA AFTER MIDNIGHT AND THE SNOW SLOWLY EXITS TO THE SOUTHEAST
THROUGH MID MONDAY MORNING.
HAVE LOWER STORM TOTAL SNOWFALL AMOUNTS THAN THE PREVIOUS FORECAST
DUE TO LESS CONFIDENCE IN BANDS OF HEAVIER SNOW AND HIGHER
CONFIDENCE IN SLEET MIXED WITH SNOW IN THE SOUTHERN CWA. EXPECTING
1 TO 2 INCHES ALONG AND SOUTH OF A OHARE TO AMBOY LINE WITH 1 TO
3...MAYBE LOCALIZED 4 INCHES SOUTH OF A GARY INDIANA TO LA SALLE
LINE.
WINDS TURN NORTH MONDAY LEADING TO THE POSSIBILITY OF LAKE EFFECT
SNOW OVER NW INDIANA MONDAY. STILL NOT OVERLY IMPRESSED WITH THE
LAKE EFFECT SET UP AS WELL WITH VERY MARGINAL DELTA T/S...DRY
FORECAST SOUNDINGS...AND SOME ICE OVER THE LAKE. AS SUCH CAPPED
POPS IN THE CHANCE RANGE. WINDS VEER TO NORTHEAST MONDAY EVENING
AND THE BAND OF SNOW SHIFTS WEST TO OVER ILLINOIS.
TEMPS MONDAY WILL VARY FROM THE MID TEENS OVER NORTH CENTRAL IL TO
THE MID 20S OVER NW INDIANA. LOWS WILL VARY FROM AROUND +10
DOWNTOWN TO 0 TO +5 IN OUTLYING AREAS. SOME ISOLATED LOCATIONS MAY
DIP BELOW ZERO.
JEE
&&
.LONG TERM...
325 AM CST
TUESDAY THROUGH SATURDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE CONUS TUESDAY WITH TROUGH
AXES/SHORTWAVES MOVING THROUGH THE REGION TUESDAY...WEDNESDAY AND
THURSDAY. THE SURFACE HIGH SITS OVER THE CWA TUESDAY AND SLOWLY
SINKS SOUTH WEDNESDAY. A CLIPPER SYSTEM PASSES TO OUR NORTH
WEDNESDAY NIGHT INTO THURSDAY WITH ANOTHER SURFACE HIGH MOVING OVER
THE REGION LATE IN THE WEEK.
LOOKING AT A DRY REST OF THE WEEK WITH HIGH TEMPS IN THE TEENS
TUESDAY AND WEDNESDAY. THEN WE GET INTO A WARMING TREND WITH AT OR
SLIGHTLY ABOVE FREEZING HIGH TEMPS BY THE END OF THE WEEK. THE ONLY
REALLY COLD NIGHT IS TUESDAY NIGHT WITH LOWS BETWEEN 0 AND -10 AWAY
FROM THE CITY BUT LIGHT WINDS WILL KEEP WIND CHILLS WARMER THAN
-20.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* SNOW MOVING IN LATE THIS AFTERNOON/EARLY THIS EVENING...ENDING
OVERNIGHT.
* IFR VSBY WITH PERIODIC LIFR POSSIBLE IN SNOW. CIGS LOWER TO
MVFR/IFR THIS EVENING.
* SOUTH TO SOUTHWEST WINDS TURN NORTHWEST EARLY TONIGHT.
MDB
//DISCUSSION...UPDATED 12Z...
VFR CONDITIONS WILL CONTINUE THROUGH THE DAY BEFORE DETERIORATING
LATE THIS AFTERNOON AND THIS EVENING AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE REGION. SNOW WILL SPREAD NORTHWARD ACROSS THE
TERMINALS LATE THIS AFTERNOON THROUGH THE EVENING...THEN COME TO
AN END OVERNIGHT. RFD WILL LIKELY REMAIN JUST NORTH OF THE SNOW
BAND BUT WILL CONTINUE WITH A PROB30 MENTION FOR NOW.
OTHERWISE...SNOW MAY FALL IN SEVERAL BANDS WHICH SUGGESTS THAT
THERE MAY BE A HIGH DEGREE OF VARIABILITY IN CIGS AND ESPECIALLY
VSBY. SNOW WILL PROBABLY FALL CONTINUOUSLY FOR THE MOST PART BUT
INTENSITY MAY FLUCTUATE QUITE A BIT. HAVE GOOD CONFIDENCE IN THE
OVERALL TIME WINDOW FOR SNOWFALL BUT THE DETAILS SUCH AS
IDENTIFYING THE BEST WINDOW FOR LOWEST VSBY REMAINS A
CHALLENGE...TANKS TO THE TRANSIENT NATURE OF THE EXPECTED
BANDS. SOUTH TO SOUTHWEST WINDS WILL PREVAIL INTO THE EVENING AS
WELL BEFORE TURNING WEST THEN NORTHWEST TONIGHT BEHIND A FRONT.
MVFR CIGS MAY END UP PREVAILING INTO MONDAY MORNING BUT THERE IS
ALSO SUPPORT FOR LESS MVFR COVERAGE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN SNOW OCCURRING THIS EVENING. HIGH CONFIDENCE
IN START TIME. MEDIUM-HIGH CONFIDENCE IN END TIME.
* HIGH CONFIDENCE IN IFR VSBY OCCURRING IN SNOW WITH MEDIUM
CONFIDENCE IN LIFR VSBY OCCURRING INTERMITTENTLY. LOW CONFIDENCE
IN DURATION OF LIFR VSBY. HIGH CONFIDENCE IN CIG TRENDS THROUGH
THE EVENING. MEDIUM CONFIDENCE IN CIG TRENDS OVERNIGHT.
* HIGH CONFIDENCE IN WIND TRENDS.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS POSSIBLE. A CHANCE OF LIGHT SNOW SHOWERS. NORTH
WINDS.
TUESDAY...MVFR CIGS POSSIBLE. NORTHEAST-EAST WINDS.
WEDNESDAY THROUGH SATURDAY...PRIMARILY VFR. SOUTHWEST TO WEST
WINDS.
MDB
&&
.MARINE...
254 AM CST
WEAK LOW PRESSURE IS MOVING ACROSS UPPER MICHIGAN THIS MORNING WITH
A TROUGH AXIS/COLD FRONT TRAILING IT TO THE SOUTHWEST. STRONG HIGH
PRESSURE OVER THE CAROLINA COAST WILL SHIFT OFFSHORE THROUGH THE DAY
ALLOWING THE SURFACE TROUGH TO SAG SOUTHEASTWARD INTO TONIGHT. THE
FAIRLY STRONG PRESSURE GRADIENT ACROSS LAKE MICHIGAN EARLY THIS
MORNING CONTINUES TO GENERATE STEADY WINDS BUT SPEEDS WILL STEADILY
DIMINISH THROUGH THE MORNING AS THE PRESSURE GRADIENT WEAKENS. WINDS
WILL SHIFT TO THE NORTHWEST TONIGHT AS THE FRONT PASSES WITH A
FURTHER SHIFT TO THE NORTH OCCURRING MONDAY MORNING. STRONG HIGH
PRESSURE ACROSS CENTRAL CANADA THIS MORNING WILL STRENGTHEN AS IT
MOVES SOUTHEAST INTO THE EASTERN DAKOTAS OVERNIGHT. AS A
RESULT...SPEEDS WILL PICK UP WITH GUSTS TO AROUND 25 KT LIKELY WITH
SOME CLOSER TO 30 KT POSSIBLE AT TIMES DURING THE DAY MONDAY BEFORE
WINDS TURN MORE TO THE NORTHEAST AND EASE MONDAY EVENING/NIGHT AS
THE HIGH SPREADS ACROSS THE LAKES.
THE HIGH WILL SHIFT SOUTH OF THE GREAT LAKES LATER WEDNESDAY. A
SERIES OF LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK ACROSS SOUTHERN
CANADA AND THE NORTHERN TIER OF STATES INTO LATE WEEK LEADING TO
PERIODIC WIND SHIFTS AND INCREASES IN SPEED.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
342 AM CST Sun Jan 11 2015
.SHORT TERM...(Today)
ISSUED AT 341 AM CST SUN JAN 11 2015
Warm air surging north ahead of the next cold front will ride up and
over the cold dome of air in place across central IL. 40kt of
isentropic lift along the 300K surface will help the layer of clouds
around 6K FT deepen with time as additional moisture arrives. Light
freezing rain or sleet will advance northward this morning, possibly
reaching our southern counties a little before Noon. At the same
time, a frontogenetical circulation across our northern counties
will work to produce light snow/sleet north of a line from
Bloomington to Havana, and especially from Peoria and north. The
models have shown this band of snow over the past several runs. So
it is possible we could have a region in the central portion of our
forecast area (generally along I-72) remain dry while snow falls
north and freezing rain/sleet falls to the south. Eventually we
should see freezing rain/sleet overspread our central counties up to
I-72 and continue into the evening. 00z/NAM soundings definitely
show a warm bias over the cooler GFS and ECMWF. We trended slightly
warmer with surface temps across the southerly half of the area as a
result, and pushed chances of freezing rain farther north as well.
In light of the northward trend for icing from freezing rain, in
conjunction with snow/sleet later in the event, we expanded the
advisory area northward another row of counties to now include
Champaign and Lincoln. Icing potential from freezing rain could
climb between one and two tenths of an inch toward the I-70
corridor. There is low potential for isolated areas to see a quarter
inch of ice, which is our trigger for an ice storm warning. If the
warmer trend is correct, our southern counties along highway 50
could become all rain later this afternoon and early evening, which
would reduce ice totals as you headed south of I-70.
The 00z/NAM is also indicating an extended period of sleet will be
possible toward I-72. If that developed, we could see 0.5" of sleet,
which is one trigger for a winter storm warning. At this point, we
do not have high enough confidence of widespread areas receiving
0.25" of ice nor 0.5" of sleet to warrant an upgrade to a winter
storm warning. We will keep the headlines as an advisory. QPF
amounts in general do not seem to support ice and sleet
accumulations that high from this event.
Even models generally lower on QPF, there is evidence in the GFS and
NAM of banded precipitation, which could create large variations in
snow/sleet/ice amounts over short distances. There is a 100mb layer
of the Fn convergent portion of frontogenesis across our forecast
area, with negative EPV just above that layer to allow for CSI-type
banding. Pinpointing those bands is difficult even this close to the
event. As hourly HRRR and RAP model updates come in and we compare
to satellite and radar, we will have a better chance to do short
term updates on snow/sleet/ice amounts where bands appear more
likely.
For now, we will stick with snow totals north of I-72 in the 1-2"
range, with ice totals of in the 0.1-0.2" range with the highest
amounts along the I-70 corridor. Sleet totals would reduce snow
amounts along the I-72 corridor and northward. So snowfall totals
will be dependent on how long the airmass supports sleet instead of
transitioning to snow.
High temps today could climb above freezing south of I-70 and
possibly toward Jacksonville. Highs could delay until later this
afternoon when the warmest air aloft reaches its peak between 22z
and 02z. Northern areas should see mainly around 30 for highs. Winds
will be southerly during most of this event, which in general is not
our normal surface wind for a major ice storm due to surface temps
and dewpoints usually rising from south to north in those
situations.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 341 AM CST SUN JAN 11 2015
Tonight after midnight, on the back edge of the storm, normally
would see more snow in the forecast soundings...but even in the wake
of the system, particularly in the east and southeast, warm air in
the mid levels holding on to more sleet potential. Models also
showing the formation of a dry slot now...between the more
frontogenetic banding to the north and the remains of the system.
This may end up taking a chunk out of the QPF for after midnight
depending on the progression of the system. That same drying
starting to show in the column Monday morning as the loss of any
crystals will steer the forecast from snow and wintry mix...to
potential for freezing drizzle. Depending on the speed of the
system, as it has been getting progressively quicker, as well as the
efficacy of the dry slot...the early morning commute on Monday
morning along and south of a line from SPI to DNV may be a bit
messy.
Beyond this weekends system, forecast dries out with high pressure
dominating the weather through next week. Wave digging in over the
western half of the CONUS shearing out the energy moving along the
southern tier of the country, missing the Midwest midweek.
Temperatures at mid levels trying to level out somewhat, but cooler
than climatology continues until a more significant chance for warm
up kicks in next weekend when southerly flow kicks in again on the
back side of exiting high pressure ridge. Same southerly flow
bringing up the next chance for precip for next weekend potentially
from the southwest...and warm enough at this point to trend in some
rain.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1105 PM CST SAT JAN 10 2015
Timing of precip and precip type the main forecast concerns this
period. Next wave of low pressure will start to affect the area on
Sunday bringing a thickening and lowering cig during the morning
with some light snow, sleet and freezing rain affecting our southern
TAF sites (KSPI, KDEC and KCMI) in the 17z-19z time frame, with
our remaining northern sites (KBMI and KPIA) seeing more of a light
snow and sleet mixture move in from 19z-21z. Once the precip begins
it will be just a matter of an hour or two before we see cigs drop
from low VFR to MVFR, and then IFR/LIFR after 00z. Forecast soundings
suggest the higher probability for freezing rain would be from SPI
to DEC to near CMI with more of a sleet and light snow mix further
north at BMI, with mostly light snow expected at PIA. Surface
temperatures across our southern TAF sites will warm to near the
freezing mark but in all probability, should begin to cool off by
a degree or two after the precip begins.
Look for the light wintry mix to continue on and off thru the night
with a transition over to light snow as the night wears on due to
a cold front pushing acrs the area and cooling temps off just enough
in the lower levels of the atmosphere for the changeover to occur.
Surface winds will remain out of the south thru the day Sunday with
speeds of 10 to 15 kts and then start to veer more into a westerly
direction late in the evening as a cold front approaches and then
passes across our forecast area during the overnight hours.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from Noon today to 9 AM CST Monday FOR
ILZ042>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1154 AM EST SUN JAN 11 2015
.SYNOPSIS...
ISSUED AT 555 AM EST SUN JAN 11 2015
A COLD FRONT DROPPING SOUTHEAST ACROSS THE GREAT LAKES WILL
COMBINE WITH A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST FROM THE
SOUTHERN PLAINS TO CAUSE SNOW TO OVERSPREAD OUR AREA FROM SOUTH
TO NORTH THIS AFTERNOON. THE SNOW WILL CONTINUE ACROSS THE AREA
TONIGHT BEFORE TAPERING OFF FROM NORTHWEST TO SOUTHEAST MONDAY
MORNING. SNOW MAY BE MIXED WITH SLEET SOUTH OF ROUTE 24. NEW SNOW
ACCUMULATIONS ARE EXPECTED TO BE 2 TO 4 INCHES... WITH HEAVIEST
AMOUNTS ALONG A KNOX INDIANA TO DEFIANCE OHIO LINE. HIGHS TODAY WILL
BE IN THE UPPER 20S AND LOWER 30S... WITH LOWS TONIGHT IN THE MID
20S.
&&
.UPDATE...
ISSUED AT 1057 AM EST SUN JAN 11 2015
ISSUED A WINTER WX ADVISORY FOR COUNTIES SE OF THE HWY 24 CORRIDOR
IN OH/IN AS 12Z NAM AND LAST SEVERAL HRRR CYCLES HAVE TRENDED A
LITTLE WARMER/NORTH WITH WARM LAYER ALOFT (1-3C) THIS EVENING/EARLY
OVERNIGHT. AS A RESULT ADDED IN SOME LIGHT ICING AND CHANCES FOR
FREEZING RAIN DURING THIS TIME. THIS IN ADDITION TO 2-3" OF
SNOW/SLEET WARRANTS THE HEADLINE. OTHERWISE...NO SIGNIFICANT CHANGES
MADE TO THE FCST INTO THIS EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM EST SUN JAN 11 2015
VIGOROUS SRN STREAM DISTURBANCE OVR CNTRL TX WILL LIFT OUT NEWD INTO
CONFLUENT FLW ACRS THE LAKES AND PHASE W/DOMINANT NRN STREAM SW
AMPLIFYING THROUGH SE CANADA. POTENT LL MSTR SURGE READILY OBSVD IN
00Z RAOBS ACRS TX/OK AND XPCD TO RACE NEWD INTO THE LAKES BY EARLY
AFTN. ISENTROPIC CHARTS IMPRESSIVE TO SAY THE LEAST W/DEEP 4+ G/KG
MIXR NOTED COMMENSURATE W/ESCALATING PRES ADVTN FM 21-09Z BFR
TAILING OFF...AND NO DOUBT TIED TO JET COUPLING ALOFT BOTH LT THIS
AFTN AND OVERNIGHT.
WHILE SHEARING NATURE OF SRN STREAM SW WILL DAMPEN BACKGROUND
FORCING...FGEN RESPONSE AND ASSOCD BANDED PCPN SEEN IN MOST
INDIVIDUAL 00Z MODEL SOLUTIONS MORE THAN ADEQUATELY HINT OF THE
POTENTIAL FOR ONE OR MORE OVER PERFORMING SNOW BANDS TO FORM BOTH
THIS AFTN AND AGAIN THIS EVENING...EITHER OF WHICH MAY YIELD
SUBSTANTIALLY MORE SNOW THAN CURRENTLY INDICATED IN GRIDS ESP
THROUGH CNTR OF CWA. PRIMARY PROBLEM THOUGH IS EXACT LOCATION W/EACH
SOLUTION VARIED ENOUGH TO DAMPEN OUT NEEDED RESOLUTION W/A BLENDED
CONSENSUS QPF SIGNAL. REGARDLESS...BUMPED PRECIP OVR ALL AREAS
HIGHER. CORRESPONDING SNOW AMTS ARE A TAD HIGHER AS WELL W/AN
EXCEPTION ACRS THE FAR SOUTH WHERE WARM NOSE INTRUSION WILL YIELD A
PD OF SLEET THIS EVENING. THERMAL PROFILES ARE LACKING W/SIG WAA
ONGOING NOW THROUGH THIS AFTN W/SHALLOW HIGH CNTRD DGZ NOTED IN BUFR
SNDGS. HWVR CONCERN EXISTS ESP IN LIGHT OF HIGHER TRENDING QPF
SIGNALS AMONG MOST MODEL GUIDANCE. WILL DEFER HEADLINES IF ANY TO
THE DAY SHIFT TO SORT OUT W/HOPEFULLY BETTER ALIGNED 12Z GUIDANCE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM EST SUN JAN 11 2015
FLOW ALOFT TRENDING ZONAL ACROSS THE CONUS THIS WEEK SO A WARMUP IN
STORE... BUT WILL NEED TO ENDURE ONE MORE COLD SNAP BEFORE THEN AS A
SHALLOW ARCTIC AIRMASS MOVES INTO THE AREA BEHIND MONDAY`S CDFNT AND
THEN LINGERS THROUGH WED NGT AS HIGH PRESSURE MOVES SLOWLY SE FROM
THE NRN PLAINS ACROSS THE MIDWEST TUE-WED. WHILE TEMPS WILL BE WELL
BLO NORMAL IN THIS TIMEFRAME... WINDS WILL BE LIGHT SO COLD SHOULD
BE A LITTLE MORE TOLERABLE THAN PAST COUPLE OF COLD WAVES AND ATTM
DONT THINK ANY WIND CHILL HEADLINES WILL BE NEEDED THIS WEEK.
MAINTAINED GOING CATEGORICAL SNOW POPS ACROSS SE TAPERING TO LOW CHC
NW MONDAY MORNING AS FGEN FORCING ALONG H85 FRONT DROPS SE ACROSS
THE AREA WITH LINGERING MOIST AIRMASS IN PLACE. CONTD LOW SLR`S SE
WITH DEEP ISOTHERMAL NEAR FREEZING LAYER IN THIS AREA AND
HIGH/SHALLOW DGZ... FCST SNOW ACCUMS <1". DRY/SHALLOW ARCTIC AIRMASS
AND WINDS QUICKLY VEERING TO NNE MONDAY SUGGESTS LITTLE POTENTIAL
FOR POST-FRONTAL LAKE EFFECT... BUT DID MAINTAIN A LOW CHC IN THE
FAR NW IN THE AFTN. MODEST CAA SHOULD HOLD TEMPS NEARLY STEADY IN
THE 20S MONDAY... PLUMMETING TO AROUND ZERO MONDAY NIGHT AS SKIES
CLEAR AND WINDS DIMINISH. SHALLOW ARCTIC AIRMASS/WK LOW LEVEL MIXING
AS HIGH BUILDS INTO THE AREA TUE-WED SHOULD LIMIT DIURNAL TEMP RISES
WITH HIGHS ONLY 10-15 AND LOWS 0 TO -10. ZONAL FLOW ALOFT AND SW LOW
LEVEL FLOW LATE IN THE WEEK SHOULD RESULT IN A GOOD WARMUP WITH
TEMPS PRBLY A BIT ABOVE NORMAL BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1153 AM EST SUN JAN 11 2015
VFR CLOUD DECK NEAR 5-6 KFT WILL CONTINUE TO LOWER THIS AFTERNOON
WITH SSW WINDS NEAR 10 KNOTS. CONDITIONS RAPIDLY DETERIORATE TO
IFR THIS EVENING AS SNOW AND DEEPER MOISTURE (POSSIBLY MIXED WITH
SLEET AT KFWA) OVERSPREADS THE REGION. OTHERWISE...LIGHT WINDS
TONIGHT WILL SHIFT NORTHWEST IN WAKE OF FRONTAL BOUNDARY MONDAY
MORNING WITH GRADUAL IMPROVEMENT IN CIGS/VIS ANTICIPATED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR INZ026-027-032>034.
MI...NONE.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR OHZ016-024-025.
LM...NONE.
&&
$$
UPDATE...STEINWEDEL
SYNOPSIS...JT
SHORT TERM...T
LONG TERM...JT
AVIATION...STEINWEDEL
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...CORRECTION
NWS NORTHERN INDIANA
1103 AM EST SUN JAN 11 2015
.SYNOPSIS...
ISSUED AT 555 AM EST SUN JAN 11 2015
A COLD FRONT DROPPING SOUTHEAST ACROSS THE GREAT LAKES WILL
COMBINE WITH A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST FROM THE
SOUTHERN PLAINS TO CAUSE SNOW TO OVERSPREAD OUR AREA FROM SOUTH
TO NORTH THIS AFTERNOON. THE SNOW WILL CONTINUE ACROSS THE AREA
TONIGHT BEFORE TAPERING OFF FROM NORTHWEST TO SOUTHEAST MONDAY
MORNING. SNOW MAY BE MIXED WITH SLEET SOUTH OF ROUTE 24. NEW SNOW
ACCUMULATIONS ARE EXPECTED TO BE 2 TO 4 INCHES... WITH HEAVIEST
AMOUNTS ALONG A KNOX INDIANA TO DEFIANCE OHIO LINE. HIGHS TODAY WILL
BE IN THE UPPER 20S AND LOWER 30S... WITH LOWS TONIGHT IN THE MID
20S.
&&
.UPDATE...
ISSUED AT 1057 AM EST SUN JAN 11 2015
ISSUED A WINTER WX ADVISORY FOR COUNTIES SE OF THE HWY 24 CORRIDOR
IN OH/IN AS 12Z NAM AND LAST SEVERAL HRRR CYCLES HAVE TRENDED A
LITTLE WARMER/NORTH WITH WARM LAYER ALOFT (1-3C) THIS EVENING/EARLY
OVERNIGHT. AS A RESULT ADDED IN SOME LIGHT ICING AND CHANCES FOR
FREEZING RAIN DURING THIS TIME. THIS IN ADDITION TO 2-3" OF
SNOW/SLEET WARRANTS THE HEADLINE. OTHERWISE...NO SIGNIFICANT CHANGES
MADE TO THE FCST INTO THIS EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM EST SUN JAN 11 2015
VIGOROUS SRN STREAM DISTURBANCE OVR CNTRL TX WILL LIFT OUT NEWD INTO
CONFLUENT FLW ACRS THE LAKES AND PHASE W/DOMINANT NRN STREAM SW
AMPLIFYING THROUGH SE CANADA. POTENT LL MSTR SURGE READILY OBSVD IN
00Z RAOBS ACRS TX/OK AND XPCD TO RACE NEWD INTO THE LAKES BY EARLY
AFTN. ISENTROPIC CHARTS IMPRESSIVE TO SAY THE LEAST W/DEEP 4+ G/KG
MIXR NOTED COMMENSURATE W/ESCALATING PRES ADVTN FM 21-09Z BFR
TAILING OFF...AND NO DOUBT TIED TO JET COUPLING ALOFT BOTH LT THIS
AFTN AND OVERNIGHT.
WHILE SHEARING NATURE OF SRN STREAM SW WILL DAMPEN BACKGROUND
FORCING...FGEN RESPONSE AND ASSOCD BANDED PCPN SEEN IN MOST
INDIVIDUAL 00Z MODEL SOLUTIONS MORE THAN ADEQUATELY HINT OF THE
POTENTIAL FOR ONE OR MORE OVER PERFORMING SNOW BANDS TO FORM BOTH
THIS AFTN AND AGAIN THIS EVENING...EITHER OF WHICH MAY YIELD
SUBSTANTIALLY MORE SNOW THAN CURRENTLY INDICATED IN GRIDS ESP
THROUGH CNTR OF CWA. PRIMARY PROBLEM THOUGH IS EXACT LOCATION W/EACH
SOLUTION VARIED ENOUGH TO DAMPEN OUT NEEDED RESOLUTION W/A BLENDED
CONSENSUS QPF SIGNAL. REGARDLESS...BUMPED PRECIP OVR ALL AREAS
HIGHER. CORRESPONDING SNOW AMTS ARE A TAD HIGHER AS WELL W/AN
EXCEPTION ACRS THE FAR SOUTH WHERE WARM NOSE INTRUSION WILL YIELD A
PD OF SLEET THIS EVENING. THERMAL PROFILES ARE LACKING W/SIG WAA
ONGOING NOW THROUGH THIS AFTN W/SHALLOW HIGH CNTRD DGZ NOTED IN BUFR
SNDGS. HWVR CONCERN EXISTS ESP IN LIGHT OF HIGHER TRENDING QPF
SIGNALS AMONG MOST MODEL GUIDANCE. WILL DEFER HEADLINES IF ANY TO
THE DAY SHIFT TO SORT OUT W/HOPEFULLY BETTER ALIGNED 12Z GUIDANCE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM EST SUN JAN 11 2015
FLOW ALOFT TRENDING ZONAL ACROSS THE CONUS THIS WEEK SO A WARMUP IN
STORE... BUT WILL NEED TO ENDURE ONE MORE COLD SNAP BEFORE THEN AS A
SHALLOW ARCTIC AIRMASS MOVES INTO THE AREA BEHIND MONDAY`S CDFNT AND
THEN LINGERS THROUGH WED NGT AS HIGH PRESSURE MOVES SLOWLY SE FROM
THE NRN PLAINS ACROSS THE MIDWEST TUE-WED. WHILE TEMPS WILL BE WELL
BLO NORMAL IN THIS TIMEFRAME... WINDS WILL BE LIGHT SO COLD SHOULD
BE A LITTLE MORE TOLERABLE THAN PAST COUPLE OF COLD WAVES AND ATTM
DONT THINK ANY WIND CHILL HEADLINES WILL BE NEEDED THIS WEEK.
MAINTAINED GOING CATEGORICAL SNOW POPS ACROSS SE TAPERING TO LOW CHC
NW MONDAY MORNING AS FGEN FORCING ALONG H85 FRONT DROPS SE ACROSS
THE AREA WITH LINGERING MOIST AIRMASS IN PLACE. CONTD LOW SLR`S SE
WITH DEEP ISOTHERMAL NEAR FREEZING LAYER IN THIS AREA AND
HIGH/SHALLOW DGZ... FCST SNOW ACCUMS <1". DRY/SHALLOW ARCTIC AIRMASS
AND WINDS QUICKLY VEERING TO NNE MONDAY SUGGESTS LITTLE POTENTIAL
FOR POST-FRONTAL LAKE EFFECT... BUT DID MAINTAIN A LOW CHC IN THE
FAR NW IN THE AFTN. MODEST CAA SHOULD HOLD TEMPS NEARLY STEADY IN
THE 20S MONDAY... PLUMMETING TO AROUND ZERO MONDAY NIGHT AS SKIES
CLEAR AND WINDS DIMINISH. SHALLOW ARCTIC AIRMASS/WK LOW LEVEL MIXING
AS HIGH BUILDS INTO THE AREA TUE-WED SHOULD LIMIT DIURNAL TEMP RISES
WITH HIGHS ONLY 10-15 AND LOWS 0 TO -10. ZONAL FLOW ALOFT AND SW LOW
LEVEL FLOW LATE IN THE WEEK SHOULD RESULT IN A GOOD WARMUP WITH
TEMPS PRBLY A BIT ABOVE NORMAL BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 555 AM EST SUN JAN 11 2015
MOISTURE STREAMING N-NE AHEAD OF SRN PLAINS SHRTWV SHOULD RESULT
IN GRADUAL LOWERING OF VFR CLOUD DECK TODAY... WITH IFR CONDITIONS
DVLPG THIS AFTN/EVE AS SNOW OVERSPREADS THE AREA FROM SOUTH-NORTH.
SNOW EXPECTED TO CONT OVERNIGHT AND THEN TAPER OFF AROUND DAYBREAK
MONDAY. MODEST SW WINDS WILL CONT TODAY... SHIFTING NW AROUND
DAYBREAK MONDAY AS A CDFNT MOVES SE ACROSS THE AREA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR INZ026-027-032>034.
MI...NONE.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR OHZ016-024-025.
LM...NONE.
&&
$$
UPDATE...STEINWEDEL
SYNOPSIS...JT
SHORT TERM...T
LONG TERM...JT
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1057 AM EST SUN JAN 11 2015
.SYNOPSIS...
ISSUED AT 555 AM EST SUN JAN 11 2015
A COLD FRONT DROPPING SOUTHEAST ACROSS THE GREAT LAKES WILL
COMBINE WITH A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST FROM THE
SOUTHERN PLAINS TO CAUSE SNOW TO OVERSPREAD OUR AREA FROM SOUTH
TO NORTH THIS AFTERNOON. THE SNOW WILL CONTINUE ACROSS THE AREA
TONIGHT BEFORE TAPERING OFF FROM NORTHWEST TO SOUTHEAST MONDAY MORNING. SNOW
MAY BE MIXED WITH SLEET SOUTH OF ROUTE 24. NEW SNOW ACCUMULATIONS
ARE EXPECTED TO BE 2 TO 4 INCHES... WITH HEAVIEST AMOUNTS ALONG A
KNOX INDIANA TO DEFIANCE OHIO LINE. HIGHS TODAY WILL BE IN THE
UPPER 20S AND LOWER 30S... WITH LOWS TONIGHT IN THE MID 20S.
&&
.UPDATE...
ISSUED AT 1057 AM EST SUN JAN 11 2015
ISSUED A WINTER WX ADVISORY FOR COUNTIES SE OF THE HWY 24 CORRIDOR
IN OH/IN AS 12Z NAM AND LAST SEVERAL HRRR CYCLES HAVE TRENDED A
LITTLE WARMER/NORTH WITH WARM LAYER ALOFT (1-3C) THIS EVENING/EARLY
OVERNIGHT. AS A RESULT ADDED IN SOME LIGHT ICING AND CHANCES FOR
FREEZING RAIN DURING THIS TIME. THIS IN ADDITIONAL TO 2-3" OF
SNOW/SLEET WARRANTS THE HEADLINE. OTHERWISE...NO SIGNIFICANT CHANGES
MADE TO THE FCST INTO THIS EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM EST SUN JAN 11 2015
VIGOROUS SRN STREAM DISTURBANCE OVR CNTRL TX WILL LIFT OUT NEWD INTO
CONFLUENT FLW ACRS THE LAKES AND PHASE W/DOMINANT NRN STREAM SW
AMPLIFYING THROUGH SE CANADA. POTENT LL MSTR SURGE READILY OBSVD IN
00Z RAOBS ACRS TX/OK AND XPCD TO RACE NEWD INTO THE LAKES BY EARLY
AFTN. ISENTROPIC CHARTS IMPRESSIVE TO SAY THE LEAST W/DEEP 4+ G/KG
MIXR NOTED COMMENSURATE W/ESCALATING PRES ADVTN FM 21-09Z BFR
TAILING OFF...AND NO DOUBT TIED TO JET COUPLING ALOFT BOTH LT THIS
AFTN AND OVERNIGHT.
WHILE SHEARING NATURE OF SRN STREAM SW WILL DAMPEN BACKGROUND
FORCING...FGEN RESPONSE AND ASSOCD BANDED PCPN SEEN IN MOST
INDIVIDUAL 00Z MODEL SOLUTIONS MORE THAN ADEQUATELY HINT OF THE
POTENTIAL FOR ONE OR MORE OVER PERFORMING SNOW BANDS TO FORM BOTH
THIS AFTN AND AGAIN THIS EVENING...EITHER OF WHICH MAY YIELD
SUBSTANTIALLY MORE SNOW THAN CURRENTLY INDICATED IN GRIDS ESP
THROUGH CNTR OF CWA. PRIMARY PROBLEM THOUGH IS EXACT LOCATION W/EACH
SOLUTION VARIED ENOUGH TO DAMPEN OUT NEEDED RESOLUTION W/A BLENDED
CONSENSUS QPF SIGNAL. REGARDLESS...BUMPED PRECIP OVR ALL AREAS
HIGHER. CORRESPONDING SNOW AMTS ARE A TAD HIGHER AS WELL W/AN
EXCEPTION ACRS THE FAR SOUTH WHERE WARM NOSE INTRUSION WILL YIELD A
PD OF SLEET THIS EVENING. THERMAL PROFILES ARE LACKING W/SIG WAA
ONGOING NOW THROUGH THIS AFTN W/SHALLOW HIGH CNTRD DGZ NOTED IN BUFR
SNDGS. HWVR CONCERN EXISTS ESP IN LIGHT OF HIGHER TRENDING QPF
SIGNALS AMONG MOST MODEL GUIDANCE. WILL DEFER HEADLINES IF ANY TO
THE DAY SHIFT TO SORT OUT W/HOPEFULLY BETTER ALIGNED 12Z GUIDANCE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM EST SUN JAN 11 2015
FLOW ALOFT TRENDING ZONAL ACROSS THE CONUS THIS WEEK SO A WARMUP IN
STORE... BUT WILL NEED TO ENDURE ONE MORE COLD SNAP BEFORE THEN AS A
SHALLOW ARCTIC AIRMASS MOVES INTO THE AREA BEHIND MONDAY`S CDFNT AND
THEN LINGERS THROUGH WED NGT AS HIGH PRESSURE MOVES SLOWLY SE FROM
THE NRN PLAINS ACROSS THE MIDWEST TUE-WED. WHILE TEMPS WILL BE WELL
BLO NORMAL IN THIS TIMEFRAME... WINDS WILL BE LIGHT SO COLD SHOULD
BE A LITTLE MORE TOLERABLE THAN PAST COUPLE OF COLD WAVES AND ATTM
DONT THINK ANY WIND CHILL HEADLINES WILL BE NEEDED THIS WEEK.
MAINTAINED GOING CATEGORICAL SNOW POPS ACROSS SE TAPERING TO LOW CHC
NW MONDAY MORNING AS FGEN FORCING ALONG H85 FRONT DROPS SE ACROSS
THE AREA WITH LINGERING MOIST AIRMASS IN PLACE. CONTD LOW SLR`S SE
WITH DEEP ISOTHERMAL NEAR FREEZING LAYER IN THIS AREA AND
HIGH/SHALLOW DGZ... FCST SNOW ACCUMS <1". DRY/SHALLOW ARCTIC AIRMASS
AND WINDS QUICKLY VEERING TO NNE MONDAY SUGGESTS LITTLE POTENTIAL
FOR POST-FRONTAL LAKE EFFECT... BUT DID MAINTAIN A LOW CHC IN THE
FAR NW IN THE AFTN. MODEST CAA SHOULD HOLD TEMPS NEARLY STEADY IN
THE 20S MONDAY... PLUMMETING TO AROUND ZERO MONDAY NIGHT AS SKIES
CLEAR AND WINDS DIMINISH. SHALLOW ARCTIC AIRMASS/WK LOW LEVEL MIXING
AS HIGH BUILDS INTO THE AREA TUE-WED SHOULD LIMIT DIURNAL TEMP RISES
WITH HIGHS ONLY 10-15 AND LOWS 0 TO -10. ZONAL FLOW ALOFT AND SW LOW
LEVEL FLOW LATE IN THE WEEK SHOULD RESULT IN A GOOD WARMUP WITH
TEMPS PRBLY A BIT ABOVE NORMAL BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 555 AM EST SUN JAN 11 2015
MOISTURE STREAMING N-NE AHEAD OF SRN PLAINS SHRTWV SHOULD RESULT
IN GRADUAL LOWERING OF VFR CLOUD DECK TODAY... WITH IFR CONDITIONS
DVLPG THIS AFTN/EVE AS SNOW OVERSPREADS THE AREA FROM SOUTH-NORTH.
SNOW EXPECTED TO CONT OVERNIGHT AND THEN TAPER OFF AROUND DAYBREAK
MONDAY. MODEST SW WINDS WILL CONT TODAY... SHIFTING NW AROUND
DAYBREAK MONDAY AS A CDFNT MOVES SE ACROSS THE AREA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR INZ026-027-032>034.
MI...NONE.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR OHZ016-024-025.
LM...NONE.
&&
$$
UPDATE...STEINWEDEL
SYNOPSIS...JT
SHORT TERM...T
LONG TERM...JT
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1149 PM CST SAT JAN 10 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 344 PM CST SAT JAN 10 2015
TEMPERATURES AND CLOUD COVER WERE THE MAIN FORECAST ISSUE FOR
TONIGHT AS SURFACE HIGH PRESSURE MOVES EAST THIS EVENING ALLOWING
FOR A WEAK TROUGH TO PUSH INTO THE STATE OVERNIGHT. FORECAST
SOUNDINGS SUGGEST AN INVERSION DEVELOPING THIS EVENING TRAPPING
LOW LEVEL MOISTURE AND RESULTING IN A STRATUS SHIELD OVER CENTRAL
TO NORTHERN IOWA. PRETTY HIGH RH AT 925MB THIS EVENING AND ALSO
SHOULD BE A LITTLE ADDED MOISTURE WITH THE STRONG WAA TODAY OVER
THE SNOW PACK. INCREASE CLOUD COVER TONIGHT WHICH SHOULD HELP KEEP
OVERNIGHT LOWS UP SLIGHTLY WARMER THAN PREVIOUSLY FORECAST. THE
HOPWRF AND HRRR HAVE CLOUD COVER THROUGH MUCH OF THE NIGHT OVER
THE NORTHERN SECTION OF THE FORECAST AREA.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 344 PM CST SAT JAN 10 2015
A FEW MINOR ISSUES IN THE NEAR TERM...WITH MAINLY A DRY AND QUIET
FORECAST THROUGHOUT THE MID/LONG RANGE. SOUTHERN STREAM UPPER
LEVEL TROUGH WILL BE LIFTING OUT OF THE SOUTHERN HIGH PLAINS
INTO THE OHIO VALLEY SUNDAY INTO EARLY MONDAY. ADDITIONALLY A
NORTHERN STREAM TROUGH WILL BE DROPPING THROUGH THE NORTHERN
PLAINS AND INTO THE GREAT LAKES WITH THAT WAVE SOMEWHAT SHEARING
APART AS IT DROPS SOUTH. WAA AND SOME WEAK THETA-E ADVECTION WILL
CREEP INTO THE FAR SOUTHEASTERN CWA WITH THE SOUTHERN STREAM
TROUGH...WHICH WILL BRING A CHANCE FOR SOME LIGHT SNOW TO THE FAR
SOUTHEASTERN CWA SUNDAY NIGHT. NAM SHOWS DEEPER SATURATION KEEPING
THE PRECIP MAINLY VERY LIGHT SNOW...WHILE THE GFS DOES SHOW SOME
QUESTION AS TO THE DEEPER SATURATION AND ICE INTRODUCTION WITH A
POTENTIAL FOR SOME VERY LIGHT FZDZ. OVERALL THE BULK OF THE PRECIP
IS EXPECTED TO STAY TO THE SOUTH AND SOUTHEAST OF THE CWA...SO
ONLY LIGHT ACCUMULATIONS UNDER AN INCH ARE POSSIBLE AND WENT WITH
HIGH CHANCE POPS. A STRONGER COLD FRONT WILL PUSH THROUGH THE CWA
WITH THE NORTHERN STREAM TROUGH AND COULD BRING SOME FLURRIES
SUNDAY NIGHT TO THE REMAINDER OF THE CWA...AND SOME GUSTY WINDS
INTO MONDAY. COLD ARCTIC HIGH PRESSURE TO BUILD INTO THE CWA FOR
MONDAY NIGHT INTO TUESDAY WITH TEMPS FALLING WELL BELOW NORMAL
AGAIN.
NORTHWESTERLY UPPER LEVEL FLOW REMAINS IN PLACE INTO
THURSDAY...WITH THE FLOW FLATTENING OUT SOME TOWARD THE WEEKEND.
THE MAIN PUSH OF SHORTWAVES SHOULD REMAIN TO THE NORTH OF THE
CWA...SO EXPECT DRY CONDITIONS WITH MAINLY AN INCREASE IN CLOUD
COVER. TEMPERATURES WARM ALOFT AS WELL THROUGH THE END OF THE
PERIOD...SO A WARMING TREND IS ON TAP THROUGH THE WEEKEND.
TEMPERATURES ARE EXPECTED TO REBOUND CLOSER TO THE SEASONAL
AVERAGE OR EVEN PUSH ABOVE AVERAGE TOWARD THE END OF THE FORECAST
PERIOD.
&&
.AVIATION...11/06Z
ISSUED AT 1149 PM CST SAT JAN 10 2015
SURFACE BOUNDARY WILL MOVE VERY SLOWLY SOUTH ACROSS THE FORECAST
AREA DURING THE REMAINDER OF THE NIGHT INTO SUNDAY. WHILE MOST
LOCATIONS WILL SEE VFR CEILINGS...LOCALIZED MVFR TO IFR CEILINGS
WILL OCCUR NEAR THE SURFACE FRONT AS IT DRIFTS SOUTHWARD. THERE
WILL BE INCREASING THREAT OF SOME LIGHT PRECIPITATION NEAR KOTM
LATE SUNDAY EVENING WITH LITTLE THREAT ELSEWHERE. WINDS WILL
INCREASE FROM THE NORTH LATE IN THE FORECAST PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...BEERENDS
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
134 PM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1216 PM MST SUN JAN 11 2015
ACROSS THE AREA AT 19Z...MOST AREAS IN THE 30S WITH SOME AREAS IN
THE WEST GETTING INTO L40S. INCREASE IN AREAL COVERAGE IN CLOUDS
EXPECTED THRU THE AFTERNOON WITH APPROACH OF FRONT. GOING FORECAST
HAS HANDLED WELL.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 400 AM MST SUN JAN 11 2015
TODAY-TONIGHT...LOOKS LIKE THE DAY WILL START OFF WITH SOME HIGH
CLOUDS GENERALLY NEAR THE KS/NE BORDER BUT AS THE DAY PROGRESSES MID
CLOUDS MOVE IN FROM THE NORTHWEST. LOW LEVELS OF THE ATMOSPHERE
REMAIN RATHER DRY SO NO PRECIPITATION EXPECTED. DURING THE OVERNIGHT
HOURS MODELS SUGGESTING A WEAK WEATHER DISTURBANCE PER 700-500MB
MOISTURE TO MOVE ALONG AND JUST SOUTH OF THE PALMER DIVIDE
BRINGING A SLIGHT CHANCE OF LIGHT SNOW TO PARTS OF FAR EASTERN
COLORADO...BEST CHANCE FOR CHEYENNE AND KIT CARSON COUNTIES. FOR
REMAINING AREAS GENERALLY ALONG/WEST OF THE CO/KS BORDER 850-700MB
MOISTURE SATURATES BUT MID LEVEL MOISTURE A BIT LACKING SO HAVE
KEPT SOME SMALL CHANCES FOR FLURRIES.
BIGGER CHALLENGE TODAY IS HIGH TEMPERATURES. MOST OF THE MODELS HAVE
BEEN WAY TOO COOL/COLD THE PAST SEVERAL DAYS EXCEPT FOR A FEW. HAVE
RELIED ON THOSE BETTER PERFORMING MODELS FOR THIS FORECAST AS TIMING
OF COLD FRONT AND ARRIVAL OF LEADING EDGE OF ARCTIC AIR WILL BE
CRITICAL. 18Z 850MB TEMPS SEVERAL DEGREES ABOVE 0F AND THROUGH 21Z
STILL ABOVE ZERO FOR ALL BUT THE NORTHERN EDGE OF YUMA COUNTY. BY
00Z THE COLD PUSH REACHES INTERSTATE 70. AFTER SEEING THE 9Z RUC AND
LATEST HRRR (WHICH DID RATHER WELL WITH SATURDAYS TEMPERATURES) HAVE
FINALIZED HIGHS IN THE MID/UPPER 30S ALONG/NORTH OF THE KS/NE BORDER
WITH 40S TO THE SOUTH. HAVE AROUND 50 IN THE TRIBUNE AREA. 1040MB
SFC HIGH REACHES THE AREA TONIGHT LOWS TONIGHT 5-10F ACROSS THE
NORTHEAST 1/2 OF THE AREA WITH 10-15F TO THE SOUTHWEST.
MONDAY-MONDAY NIGHT...1043MB SFC HIGH NOSING INTO THE AREA DURING
THE MORNING THEN WEAKENING JUST A BIT. SHOULD SEE SOME LINGERING
LIGHT SNOW ACROSS MOST OF FAR EASTERN COLORADO IN THE MORNING BEFORE
MID LEVEL MOISTURE MOVES AWAY LEAVING THE AREA UNDER PLENTY OF
CLOUDS. FOR THE OVERNIGHT HOURS WE ARE IN BETWEEN DEPARTING SYSTEM
AND APPROACHING UPPER TROUGH AND NEXT BATCH OF MOISTURE WITH SHORT
WAVE RIDGING OVER THE AREA. MID LEVEL MOISTURE LACKING FOR ANY
PRECIP SO JUST MOSTLY CLOUDY/CLOUDY CONDITIONS EXPECTED. HIGH
TEMPERATURES ONLY IN THE MID TEENS TO LOW 20S (NORTHEAST TO
SOUTHWEST ORIENTATION ACROSS THE AREA) WITH OVERNIGHT LOWS GENERALLY
5F-13F.
TUESDAY-TUESDAY NIGHT...AROUND SUNRISE BASE OF UPPER TROUGH EXPECTED
OVER SALT LAKE CITY AREA CLOSING OFF WHILE MOVING SOUTHEAST TOWARD
NORTHWEST NEW MEXICO/FOUR CORNERS AREA. DURING THE OVERNIGHT HOURS
WEAKEN THE LOW A BIT WHILE ALSO PUSHING IT EAST/SOUTHEAST.
FORECAST ISSUE FOR THE PERIOD IS TIMING AND PLACEMENT OF
PRECIPITATION CHANCES. MODELS IN GENERAL AGREE ON BRINGING
INCREASING MOISTURE TO THE AREA FROM THE WEST/SOUTHWEST DURING THE
DAY WITH A BIT OF DIFFERING SOLUTIONS AS TO WHETHER OR NOT SOME
DRIER AIR MOVES IN FROM THE NORTHWEST. NAM SAYS NO WHILE GFS/ECMWF
SAY YES. SO FOR NOW VERY LITTLE CHANGE MADE TO FORECAST. GFS/ECWMF
IN BETTER AGREEMENT BRINGING DRIER IN FROM THE NORTHWEST DURING THE
NIGHT WHICH IS SIMILAR TO LAST NIGHTS SOLUTIONS. SO FOR NOW...NO
CHANGES MADE.
TEMPERATURES WILL CONTINUE TO BE COLD WITH HIGH TEMPERATURES IN THE
LOW TO MID 20S AND LOWS GENERALLY 10-15F...COLDEST AROUND MCCOOK
WITH HIGHEST VALUES FROM FLAGLER TO LEOTI.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 211 AM MST SUN JAN 11 2015
FORECAST CHALLENGES ARE RESOLVING THE WARMING TEMPERATURES AND
PERSISTENT WEST TO EAST/WARM TO COOL GRADIENT ACROSS THE FORECAST
AREA.
THE UPPER TROUGH THAT MOVED THROUGH THE CENTRAL HIGH PLAINS REGION
LATE TUESDAY AND TUESDAY NIGHT MOVES OUT OF THE REGION WEDNESDAY.
NORTHWEST FLOW WILL BE IN PLACE WEDNESDAY NIGHT AND THURSDAY AS THE
UPPER RIDGE MOVES OVER THE ROCKIES AND HIGH PLAINS. COLD AIR AT THE
SURFACE IS SWEPT OUT OF THE CENTRAL HIGH PLAINS AS THE HIGH PRESSURE
AREA MOVES EAST AND A LEE TROUGH DEEPENS NEAR THE EASTERN COLORADO
BORDER.
DIFFERENCES ARE SHOWING UP BETWEEN THE GFS AND ECMWF OVER THE
CENTRAL HIGH PLAINS REGION THURSDAY NIGHT AND FRIDAY. THE ECMWF IS
PRODUCING TWO SEPARATE WEAKER SHORT WAVE TROUGHS THAT MOVE ACROSS
THE FORECAST AREA WHILE THE GFS IS PRODUCING A STRONGER CLOSED LOW
CENTER THAT FITS INTO THE TIMING OF THE SECOND OPEN WAVE
IDENTIFIED BY THE ECMWF FRIDAY AFTERNOON AND EVENING. MAY END UP
JUST SEEING AN INCREASE IN HIGH CLOUDS ASSOCIATED WITH THE WAVE ON
FRIDAY...BUT EXTENDED BLEND MAY BE TOO DRY AS IT HAS VERY LITTLE
CLOUD COVER IN FORECAST BEYOND WEDNESDAY WITH OVERALL DRY
CONDITIONS AND TEMPERATURES WARMING THROUGH THE END OF THE WEEK
WITH RIDGING ALOFT EXPECTED ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 400 AM MST SUN JAN 11 2015
KGLD...VFR CONDITIONS THROUGH 22Z WITH WINDS VARIABLE AT 5KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH A GRADUAL
INCREASE IN CLOUDS STARTING MID TO LATE MORNING. AROUND 23Z
STRATUS STARTS TO APPROACH THE TERMINAL AS WINDS BECOME NORTHERLY
AROUND 10KTS. ITS EXPECTED THAT FROM 00Z THROUGH 11Z STRATUS WILL
COVER THE TERMINAL WITH VLIFR CIGS. SHORTLY AFTER 11Z STRATUS
CONCENTRATION SHIFTS TO THE WEST POSSIBLY ALLOWING VFR CONDITIONS
TO RETURN WITH NORTHEAST WINDS AROUND 10KTS. SOME SNOW FLURRIES
ARE POSSIBLE AT THE TAIL END OF THE PERIOD.
KMCK...VFR CONDITIONS THROUGH 20Z WITH WINDS VARIABLE AT 3KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH AN INCREASE IN
MID AND HIGH CLOUDS MID TO LATE MORNING. AROUND 21Z STRATUS
APPROACHES THE TERMINAL FROM THE NORTH WITH WINDS SHIFTING TO THE
NORTHEAST AROUND 5KTS. BY 23Z IF NOT AN HOUR OR POSSIBLY TWO
EARLIER VLIFR CIGS EXPECTED WITH NORTH WINDS AROUND 10KTS. THESE
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 06Z-07Z BEFORE
RETURNING TO VFR AS THE SATURATED LOW LEVEL AIRMASS MOVES
WEST/SOUTHWEST OF THE TERMINAL.
&&
.HYDROLOGY...
ISSUED AT 133 PM MST SUN JAN 11 2015
ICE JAM CONCERNS WILL PERSIST OVER THE NEXT SEVERAL DAYS ON
THE REPUBLICAN RIVER NEAR DOANE RD 333...SOUTH AND WEST OF
BENKELMAN. WITH MOST OF THE UPCOMING WEEK HAVING HIGH TEMPS NEAR TO
ABOVE FREEZING...AND OVERNIGHT LOWS DROPPING INTO THE TEENS AND EVEN
SINGLE NUMBERS ABOVE ZERO EARLY ON...THE RIVER IN THAT AREA WILL SEE
FREEZING AT NIGHT WITH MELTING OF ICE DURING THE DAY. RISES IN THE
GRAPH GAGE OF BENN1 DO REFLECT THIS ALTHOUGH A DECREASING TREND HAS
BEEN SEEN OVER PAST FEW DAYS. ALTHOUGH THIS GAGE IS A FEW MILES
DOWNSTREAM FROM THE TROUBLE SITE...TREND DOES REFLECT. OVERALL SITE
WILL HAVE TO CONTINUE TO BE MONITORED DURING THIS TIME. THE ONLY
HELP THIS AREA WILL SEE IS THAT THE WARMING TREND BY THE END OF THE
WEEK MAY DO ENOUGH MELTING DURING THE DAY ON THE RIVER ICE TO
ALLEVIATE CONDITIONS TO REDUCE MINOR FLOODING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...99
LONG TERM...LOCKHART
AVIATION...99
HYDROLOGY...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1216 PM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1216 PM MST SUN JAN 11 2015
ACROSS THE AREA AT 19Z...MOST AREAS IN THE 30S WITH SOME AREAS IN
THE WEST GETTING INTO L40S. INCREASE IN AREAL COVERAGE IN CLOUDS
EXPECTED THRU THE AFTERNOON WITH APPROACH OF FRONT. GOING FORECAST
HAS HANDLED WELL.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 400 AM MST SUN JAN 11 2015
TODAY-TONIGHT...LOOKS LIKE THE DAY WILL START OFF WITH SOME HIGH
CLOUDS GENERALLY NEAR THE KS/NE BORDER BUT AS THE DAY PROGRESSES MID
CLOUDS MOVE IN FROM THE NORTHWEST. LOW LEVELS OF THE ATMOSPHERE
REMAIN RATHER DRY SO NO PRECIPITATION EXPECTED. DURING THE OVERNIGHT
HOURS MODELS SUGGESTING A WEAK WEATHER DISTURBANCE PER 700-500MB
MOISTURE TO MOVE ALONG AND JUST SOUTH OF THE PALMER DIVIDE
BRINGING A SLIGHT CHANCE OF LIGHT SNOW TO PARTS OF FAR EASTERN
COLORADO...BEST CHANCE FOR CHEYENNE AND KIT CARSON COUNTIES. FOR
REMAINING AREAS GENERALLY ALONG/WEST OF THE CO/KS BORDER 850-700MB
MOISTURE SATURATES BUT MID LEVEL MOISTURE A BIT LACKING SO HAVE
KEPT SOME SMALL CHANCES FOR FLURRIES.
BIGGER CHALLENGE TODAY IS HIGH TEMPERATURES. MOST OF THE MODELS HAVE
BEEN WAY TOO COOL/COLD THE PAST SEVERAL DAYS EXCEPT FOR A FEW. HAVE
RELIED ON THOSE BETTER PERFORMING MODELS FOR THIS FORECAST AS TIMING
OF COLD FRONT AND ARRIVAL OF LEADING EDGE OF ARCTIC AIR WILL BE
CRITICAL. 18Z 850MB TEMPS SEVERAL DEGREES ABOVE 0F AND THROUGH 21Z
STILL ABOVE ZERO FOR ALL BUT THE NORTHERN EDGE OF YUMA COUNTY. BY
00Z THE COLD PUSH REACHES INTERSTATE 70. AFTER SEEING THE 9Z RUC AND
LATEST HRRR (WHICH DID RATHER WELL WITH SATURDAYS TEMPERATURES) HAVE
FINALIZED HIGHS IN THE MID/UPPER 30S ALONG/NORTH OF THE KS/NE BORDER
WITH 40S TO THE SOUTH. HAVE AROUND 50 IN THE TRIBUNE AREA. 1040MB
SFC HIGH REACHES THE AREA TONIGHT LOWS TONIGHT 5-10F ACROSS THE
NORTHEAST 1/2 OF THE AREA WITH 10-15F TO THE SOUTHWEST.
MONDAY-MONDAY NIGHT...1043MB SFC HIGH NOSING INTO THE AREA DURING
THE MORNING THEN WEAKENING JUST A BIT. SHOULD SEE SOME LINGERING
LIGHT SNOW ACROSS MOST OF FAR EASTERN COLORADO IN THE MORNING BEFORE
MID LEVEL MOISTURE MOVES AWAY LEAVING THE AREA UNDER PLENTY OF
CLOUDS. FOR THE OVERNIGHT HOURS WE ARE IN BETWEEN DEPARTING SYSTEM
AND APPROACHING UPPER TROUGH AND NEXT BATCH OF MOISTURE WITH SHORT
WAVE RIDGING OVER THE AREA. MID LEVEL MOISTURE LACKING FOR ANY
PRECIP SO JUST MOSTLY CLOUDY/CLOUDY CONDITIONS EXPECTED. HIGH
TEMPERATURES ONLY IN THE MID TEENS TO LOW 20S (NORTHEAST TO
SOUTHWEST ORIENTATION ACROSS THE AREA) WITH OVERNIGHT LOWS GENERALLY
5F-13F.
TUESDAY-TUESDAY NIGHT...AROUND SUNRISE BASE OF UPPER TROUGH EXPECTED
OVER SALT LAKE CITY AREA CLOSING OFF WHILE MOVING SOUTHEAST TOWARD
NORTHWEST NEW MEXICO/FOUR CORNERS AREA. DURING THE OVERNIGHT HOURS
WEAKEN THE LOW A BIT WHILE ALSO PUSHING IT EAST/SOUTHEAST.
FORECAST ISSUE FOR THE PERIOD IS TIMING AND PLACEMENT OF
PRECIPITATION CHANCES. MODELS IN GENERAL AGREE ON BRINGING
INCREASING MOISTURE TO THE AREA FROM THE WEST/SOUTHWEST DURING THE
DAY WITH A BIT OF DIFFERING SOLUTIONS AS TO WHETHER OR NOT SOME
DRIER AIR MOVES IN FROM THE NORTHWEST. NAM SAYS NO WHILE GFS/ECMWF
SAY YES. SO FOR NOW VERY LITTLE CHANGE MADE TO FORECAST. GFS/ECWMF
IN BETTER AGREEMENT BRINGING DRIER IN FROM THE NORTHWEST DURING THE
NIGHT WHICH IS SIMILAR TO LAST NIGHTS SOLUTIONS. SO FOR NOW...NO
CHANGES MADE.
TEMPERATURES WILL CONTINUE TO BE COLD WITH HIGH TEMPERATURES IN THE
LOW TO MID 20S AND LOWS GENERALLY 10-15F...COLDEST AROUND MCCOOK
WITH HIGHEST VALUES FROM FLAGLER TO LEOTI.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 211 AM MST SUN JAN 11 2015
FORECAST CHALLENGES ARE RESOLVING THE WARMING TEMPERATURES AND
PERSISTENT WEST TO EAST/WARM TO COOL GRADIENT ACROSS THE FORECAST
AREA.
THE UPPER TROUGH THAT MOVED THROUGH THE CENTRAL HIGH PLAINS REGION
LATE TUESDAY AND TUESDAY NIGHT MOVES OUT OF THE REGION WEDNESDAY.
NORTHWEST FLOW WILL BE IN PLACE WEDNESDAY NIGHT AND THURSDAY AS THE
UPPER RIDGE MOVES OVER THE ROCKIES AND HIGH PLAINS. COLD AIR AT THE
SURFACE IS SWEPT OUT OF THE CENTRAL HIGH PLAINS AS THE HIGH PRESSURE
AREA MOVES EAST AND A LEE TROUGH DEEPENS NEAR THE EASTERN COLORADO
BORDER.
DIFFERENCES ARE SHOWING UP BETWEEN THE GFS AND ECMWF OVER THE
CENTRAL HIGH PLAINS REGION THURSDAY NIGHT AND FRIDAY. THE ECMWF IS
PRODUCING TWO SEPARATE WEAKER SHORT WAVE TROUGHS THAT MOVE ACROSS
THE FORECAST AREA WHILE THE GFS IS PRODUCING A STRONGER CLOSED LOW
CENTER THAT FITS INTO THE TIMING OF THE SECOND OPEN WAVE
IDENTIFIED BY THE ECMWF FRIDAY AFTERNOON AND EVENING. MAY END UP
JUST SEEING AN INCREASE IN HIGH CLOUDS ASSOCIATED WITH THE WAVE ON
FRIDAY...BUT EXTENDED BLEND MAY BE TOO DRY AS IT HAS VERY LITTLE
CLOUD COVER IN FORECAST BEYOND WEDNESDAY WITH OVERALL DRY
CONDITIONS AND TEMPERATURES WARMING THROUGH THE END OF THE WEEK
WITH RIDGING ALOFT EXPECTED ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 400 AM MST SUN JAN 11 2015
KGLD...VFR CONDITIONS THROUGH 22Z WITH WINDS VARIABLE AT 5KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH A GRADUAL
INCREASE IN CLOUDS STARTING MID TO LATE MORNING. AROUND 23Z
STRATUS STARTS TO APPROACH THE TERMINAL AS WINDS BECOME NORTHERLY
AROUND 10KTS. ITS EXPECTED THAT FROM 00Z THROUGH 11Z STRATUS WILL
COVER THE TERMINAL WITH VLIFR CIGS. SHORTLY AFTER 11Z STRATUS
CONCENTRATION SHIFTS TO THE WEST POSSIBLY ALLOWING VFR CONDITIONS
TO RETURN WITH NORTHEAST WINDS AROUND 10KTS. SOME SNOW FLURRIES
ARE POSSIBLE AT THE TAIL END OF THE PERIOD.
KMCK...VFR CONDITIONS THROUGH 20Z WITH WINDS VARIABLE AT 3KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH AN INCREASE IN
MID AND HIGH CLOUDS MID TO LATE MORNING. AROUND 21Z STRATUS
APPROACHES THE TERMINAL FROM THE NORTH WITH WINDS SHIFTING TO THE
NORTHEAST AROUND 5KTS. BY 23Z IF NOT AN HOUR OR POSSIBLY TWO
EARLIER VLIFR CIGS EXPECTED WITH NORTH WINDS AROUND 10KTS. THESE
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 06Z-07Z BEFORE
RETURNING TO VFR AS THE SATURATED LOW LEVEL AIRMASS MOVES
WEST/SOUTHWEST OF THE TERMINAL.
&&
.HYDROLOGY...
ISSUED AT 916 AM MST SUN JAN 11 2015
FLSGLD HAS BEEN RE-ISSUED FOR THE NEXT 12 HOURS TO ACCOMMODATE
MINOR ICE JAM FLOODING NEAR DOANE RD 333...5SM WEST OF BENKELMAN.
LATEST CALL TO COUNTY DISPATCH HAS GIVEN US A NO CHANGE IN
CONDITIONS AT THIS TIME. WILL CONTINUE TO MONITOR THRU THE DAY. A
COMBINATION OF FREEZING TEMPS AT NIGHT..WITH THE ADDITION OF
WATER LET LOOSE FROM DAM UPSTREAM COULD ALLOW CONDITIONS TO
CONTINUE FOR NEXT SEVERAL DAYS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...99
LONG TERM...LOCKHART
AVIATION...99
HYDROLOGY...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
916 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 910 AM MST SUN JAN 11 2015
UPDATE ISSUED TO MAKE MINOR CHANGES IN TEMPS BASED OFF OF LATEST
HOURLIES...OTHERWISE FORECAST IN GOOD SHAPE AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 400 AM MST SUN JAN 11 2015
TODAY-TONIGHT...LOOKS LIKE THE DAY WILL START OFF WITH SOME HIGH
CLOUDS GENERALLY NEAR THE KS/NE BORDER BUT AS THE DAY PROGRESSES MID
CLOUDS MOVE IN FROM THE NORTHWEST. LOW LEVELS OF THE ATMOSPHERE
REMAIN RATHER DRY SO NO PRECIPITATION EXPECTED. DURING THE OVERNIGHT
HOURS MODELS SUGGESTING A WEAK WEATHER DISTURBANCE PER 700-500MB
MOISTURE TO MOVE ALONG AND JUST SOUTH OF THE PALMER DIVIDE
BRINGING A SLIGHT CHANCE OF LIGHT SNOW TO PARTS OF FAR EASTERN
COLORADO...BEST CHANCE FOR CHEYENNE AND KIT CARSON COUNTIES. FOR
REMAINING AREAS GENERALLY ALONG/WEST OF THE CO/KS BORDER 850-700MB
MOISTURE SATURATES BUT MID LEVEL MOISTURE A BIT LACKING SO HAVE
KEPT SOME SMALL CHANCES FOR FLURRIES.
BIGGER CHALLENGE TODAY IS HIGH TEMPERATURES. MOST OF THE MODELS HAVE
BEEN WAY TOO COOL/COLD THE PAST SEVERAL DAYS EXCEPT FOR A FEW. HAVE
RELIED ON THOSE BETTER PERFORMING MODELS FOR THIS FORECAST AS TIMING
OF COLD FRONT AND ARRIVAL OF LEADING EDGE OF ARCTIC AIR WILL BE
CRITICAL. 18Z 850MB TEMPS SEVERAL DEGREES ABOVE 0F AND THROUGH 21Z
STILL ABOVE ZERO FOR ALL BUT THE NORTHERN EDGE OF YUMA COUNTY. BY
00Z THE COLD PUSH REACHES INTERSTATE 70. AFTER SEEING THE 9Z RUC AND
LATEST HRRR (WHICH DID RATHER WELL WITH SATURDAYS TEMPERATURES) HAVE
FINALIZED HIGHS IN THE MID/UPPER 30S ALONG/NORTH OF THE KS/NE BORDER
WITH 40S TO THE SOUTH. HAVE AROUND 50 IN THE TRIBUNE AREA. 1040MB
SFC HIGH REACHES THE AREA TONIGHT LOWS TONIGHT 5-10F ACROSS THE
NORTHEAST 1/2 OF THE AREA WITH 10-15F TO THE SOUTHWEST.
MONDAY-MONDAY NIGHT...1043MB SFC HIGH NOSING INTO THE AREA DURING
THE MORNING THEN WEAKENING JUST A BIT. SHOULD SEE SOME LINGERING
LIGHT SNOW ACROSS MOST OF FAR EASTERN COLORADO IN THE MORNING BEFORE
MID LEVEL MOISTURE MOVES AWAY LEAVING THE AREA UNDER PLENTY OF
CLOUDS. FOR THE OVERNIGHT HOURS WE ARE IN BETWEEN DEPARTING SYSTEM
AND APPROACHING UPPER TROUGH AND NEXT BATCH OF MOISTURE WITH SHORT
WAVE RIDGING OVER THE AREA. MID LEVEL MOISTURE LACKING FOR ANY
PRECIP SO JUST MOSTLY CLOUDY/CLOUDY CONDITIONS EXPECTED. HIGH
TEMPERATURES ONLY IN THE MID TEENS TO LOW 20S (NORTHEAST TO
SOUTHWEST ORIENTATION ACROSS THE AREA) WITH OVERNIGHT LOWS GENERALLY
5F-13F.
TUESDAY-TUESDAY NIGHT...AROUND SUNRISE BASE OF UPPER TROUGH EXPECTED
OVER SALT LAKE CITY AREA CLOSING OFF WHILE MOVING SOUTHEAST TOWARD
NORTHWEST NEW MEXICO/FOUR CORNERS AREA. DURING THE OVERNIGHT HOURS
WEAKEN THE LOW A BIT WHILE ALSO PUSHING IT EAST/SOUTHEAST.
FORECAST ISSUE FOR THE PERIOD IS TIMING AND PLACEMENT OF
PRECIPITATION CHANCES. MODELS IN GENERAL AGREE ON BRINGING
INCREASING MOISTURE TO THE AREA FROM THE WEST/SOUTHWEST DURING THE
DAY WITH A BIT OF DIFFERING SOLUTIONS AS TO WHETHER OR NOT SOME
DRIER AIR MOVES IN FROM THE NORTHWEST. NAM SAYS NO WHILE GFS/ECMWF
SAY YES. SO FOR NOW VERY LITTLE CHANGE MADE TO FORECAST. GFS/ECWMF
IN BETTER AGREEMENT BRINGING DRIER IN FROM THE NORTHWEST DURING THE
NIGHT WHICH IS SIMILAR TO LAST NIGHTS SOLUTIONS. SO FOR NOW...NO
CHANGES MADE.
TEMPERATURES WILL CONTINUE TO BE COLD WITH HIGH TEMPERATURES IN THE
LOW TO MID 20S AND LOWS GENERALLY 10-15F...COLDEST AROUND MCCOOK
WITH HIGHEST VALUES FROM FLAGLER TO LEOTI.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 211 AM MST SUN JAN 11 2015
FORECAST CHALLENGES ARE RESOLVING THE WARMING TEMPERATURES AND
PERSISTENT WEST TO EAST/WARM TO COOL GRADIENT ACROSS THE FORECAST
AREA.
THE UPPER TROUGH THAT MOVED THROUGH THE CENTRAL HIGH PLAINS REGION
LATE TUESDAY AND TUESDAY NIGHT MOVES OUT OF THE REGION WEDNESDAY.
NORTHWEST FLOW WILL BE IN PLACE WEDNESDAY NIGHT AND THURSDAY AS THE
UPPER RIDGE MOVES OVER THE ROCKIES AND HIGH PLAINS. COLD AIR AT THE
SURFACE IS SWEPT OUT OF THE CENTRAL HIGH PLAINS AS THE HIGH PRESSURE
AREA MOVES EAST AND A LEE TROUGH DEEPENS NEAR THE EASTERN COLORADO
BORDER.
DIFFERENCES ARE SHOWING UP BETWEEN THE GFS AND ECMWF OVER THE
CENTRAL HIGH PLAINS REGION THURSDAY NIGHT AND FRIDAY. THE ECMWF IS
PRODUCING TWO SEPARATE WEAKER SHORT WAVE TROUGHS THAT MOVE ACROSS
THE FORECAST AREA WHILE THE GFS IS PRODUCING A STRONGER CLOSED LOW
CENTER THAT FITS INTO THE TIMING OF THE SECOND OPEN WAVE
IDENTIFIED BY THE ECMWF FRIDAY AFTERNOON AND EVENING. MAY END UP
JUST SEEING AN INCREASE IN HIGH CLOUDS ASSOCIATED WITH THE WAVE ON
FRIDAY...BUT EXTENDED BLEND MAY BE TOO DRY AS IT HAS VERY LITTLE
CLOUD COVER IN FORECAST BEYOND WEDNESDAY WITH OVERALL DRY
CONDITIONS AND TEMPERATURES WARMING THROUGH THE END OF THE WEEK
WITH RIDGING ALOFT EXPECTED ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 400 AM MST SUN JAN 11 2015
KGLD...VFR CONDITIONS THROUGH 22Z WITH WINDS VARIABLE AT 5KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH A GRADUAL
INCREASE IN CLOUDS STARTING MID TO LATE MORNING. AROUND 23Z
STRATUS STARTS TO APPROACH THE TERMINAL AS WINDS BECOME NORTHERLY
AROUND 10KTS. ITS EXPECTED THAT FROM 00Z THROUGH 11Z STRATUS WILL
COVER THE TERMINAL WITH VLIFR CIGS. SHORTLY AFTER 11Z STRATUS
CONCENTRATION SHIFTS TO THE WEST POSSIBLY ALLOWING VFR CONDITIONS
TO RETURN WITH NORTHEAST WINDS AROUND 10KTS. SOME SNOW FLURRIES
ARE POSSIBLE AT THE TAIL END OF THE PERIOD.
KMCK...VFR CONDITIONS THROUGH 20Z WITH WINDS VARIABLE AT 3KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH AN INCREASE IN
MID AND HIGH CLOUDS MID TO LATE MORNING. AROUND 21Z STRATUS
APPROACHES THE TERMINAL FROM THE NORTH WITH WINDS SHIFTING TO THE
NORTHEAST AROUND 5KTS. BY 23Z IF NOT AN HOUR OR POSSIBLY TWO
EARLIER VLIFR CIGS EXPECTED WITH NORTH WINDS AROUND 10KTS. THESE
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 06Z-07Z BEFORE
RETURNING TO VFR AS THE SATURATED LOW LEVEL AIRMASS MOVES
WEST/SOUTHWEST OF THE TERMINAL.
&&
.HYDROLOGY...
ISSUED AT 916 AM MST SUN JAN 11 2015
FLSGLD HAS BEEN RE-ISSUED FOR THE NEXT 12 HOURS TO ACCOMMODATE
MINOR ICE JAM FLOODING NEAR DOANE RD 333...5SM WEST OF BENKELMAN.
LATEST CALL TO COUNTY DISPATCH HAS GIVEN US A NO CHANGE IN
CONDITIONS AT THIS TIME. WILL CONTINUE TO MONITOR THRU THE DAY. A
COMBINATION OF FREEZING TEMPS AT NIGHT..WITH THE ADDITION OF
WATER LET LOOSE FROM DAM UPSTREAM COULD ALLOW CONDITIONS TO
CONTINUE FOR NEXT SEVERAL DAYS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...99
LONG TERM...LOCKHART
AVIATION...99
HYDROLOGY...JN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
900 AM CST SUN JAN 11 2015
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 900 AM CST SUN JAN 11 2015
WV IMAGERY AND 12Z UPPER AIR ANALYSIS INDICATE A WEAK UPPER LEVEL
SHORTWAVE TROUGH LIFTING NORTHEASTWARD ACROSS THE CENTRAL PLAINS
THIS MORNING. MEANWHILE, ANOTHER WEAK UPPER LEVEL SHORTWAVE IS
PUSHING ASHORE INTO SOUTHERN CALIFORNIA. NEAR THE SURFACE, A LEE
SIDE TROUGH OF LOW PRESSURE IS SITUATED NEAR AND ALONG THE COLORADO
BORDER WHILE A COLD FRONT IS SINKING SOUTHWARD ACROSS THE NORTHERN
PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST SUN JAN 11 2015
OTHER THAN POTENTIAL FOR FOG DEVELOPMENT LATER THIS MORNING, THE
SHORT TERM FORECAST IS ONE OF FAIRLY BENIGN WEATHER. SOMEWHAT
RELATIVE UNCERTAINTY EXISTS WITH RESPECT TO TEMPERATURES AT LEAST
THIS AFTERNOON AS WELL. THE WEAK COLD FRONT POISED TO MOVE INTO THE
AREA LATER TONIGHT WAS POSITIONED ACROSS NORTHWEST KANSAS INTO
EASTERN NEBRASKA. LIGHT SOUTHWEST WILL PERSIST AHEAD OF THIS SURFACE
FEATURE TODAY. ALREADY THIS MORNING, THE DEW POINT DEPRESSIONS HAVE
FALLEN TO ONE TO THREE DEGREES AT LOCATIONS LIKE SCOTT CITY, TO
SYRACUSE AND GARDEN CITY, WHERE THE NAM WAS MOST PRONOUNCED IN
DEVELOPING FOG. THE MODEL TREND WAS TO DEVELOP THIS SURFACE
RADIATION FOG BETWEEN AROUND 11 TO 14 Z BEFORE AN
INSOLATION/VERTICAL MIXING INDUCED DISSIPATION. TEMPERATURES FOR THIS
AFTERNOON WILL ALSO BE A CHALLENGE AS THE MID LEVEL CLOUDS NOW
INCREASING ACROSS SOUTH CENTRAL KANSAS WILL INHIBIT INSOLATION AND
RESULTANT SURFACE HEATING LATER IN THE MORNING. TEMPERATURES WILL BE
WARMEST IN THE WEST THIS AFTERNOON. THE COLD FRONT WILL PLUNGE
THROUGH WESTERN KANSAS AROUND 00 UTC AS A MID LEVEL WAVE SHIFTS INTO
EASTERN KANSAS THIS EVENING. THE MODELS AND MOS OUTPUT INDICATE A
HIGH LEVEL OF AGREEMENT ON LOWS OVERNIGHT IN THE LOW SINGLE DIGITS
CWA-WIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CST SUN JAN 11 2015
MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH AN UPPER LEVEL
TROUGH, LOCATED AROUND 50N 140W AT 00Z SUNDAY, MOVING ACROSS THE
NORTHWESTERN UNITED STATES ON MONDAY. BY 12Z TUESDAY THIS UPPER
LEVEL SYSTEM WILL BE LOCATED AROUND THE FOUR CORNERS REGION. AS
THIS NEXT SYSTEM MOVES INTO THE FOUR CORNERS REGION ON MONDAY A
SURFACE RIDGE AXIS WILL BE CROSSING CENTRAL KANSAS AND MID TO HIGH
LEVEL MOISTURE WILL BEGIN TO SPREAD ACROSS WESTERN KANSAS. BASED
ON THE INCREASING CLOUD COVER AND NORTHEAST/EASTERLY FLOW OF COLD
AIR IN THE LOWER LEVELS ADVECTING INTO WESTERN KANSAS THE PREVIOUS
FORECAST STILL LOOKS ON TRACK WITH HIGHS MAINLY IN THE LOW TO MID
20S.
MONDAY NIGHT AND TUESDAY THE SURFACE WINDS WILL GRADUALLY VEER TO
THE SOUTH/SOUTHEAST AS THE SURFACE HIGH SLIDES EAST TOWARDS THE
MISSISSIPPI VALLEY. AS THE SOUTH/SOUTHEASTERLY FLOW DEVELOPS THE
0-1KM AGL DEWPOINTS WILL BEGIN TO SLOWLY INCREASE ACROSS FAR
WESTERN/SOUTHWEST KANSAS AND WARM AIR ADVECTION WILL BEGIN TO
DEVELOP. 800MB TO 500MB MOISTURE IS ALSO FORECAST TO CONTINUE TO
INCREASE ACROSS THE CENTRAL HIGH PLAINS AS THE UPPER LEVEL TROUGH
MOVES EAST TOWARDS THE CENTRAL ROCKIES. AT THIS TIME PRECIPITATION
CHANCES THROUGH MID DAY ON TUESDAY APPEARS SMALL GIVEN THE LIMITED
LOW LEVEL MOISTURE AND LIFT, EVEN FROM THE MORE AGGRESSIVE NAM AND
ECMWF. BY TUESDAY AFTERNOON SOME LIGHT SNOW WILL BE POSSIBLE
ACROSS PORTIONS OF WESTERN GIVEN THE INCREASING MOISTURE AND LIFT
IN THE 900MB TO 800MB LEVEL FROM THE NAM AND ECMWF. THIS
PRECIPITATION WILL THEN SPREAD NORTH AND EAST THROUGH THE
OVERNIGHT HOURS AS 700MB FRONTOGENESIS IMPROVES AHEAD OF THE UPPER
LEVEL TROUGH/LOW WHICH WILL BE MOVING EAST ACROSS NEW MEXICO AND
COLORADO TUESDAY NIGHT. CONFIDENCE ON SNOWFALL AMOUNTS STILL
REMAIN LOW ACROSS WESTERN KANSAS THIS MORNING GIVEN THE CURRENT
DISCREPANCIES BETWEEN THE MODELS CONCERNING MOISTURE AND LIFT,
EVEN WITH THE ENHANCED LIFT FROM THE 700MB FRONTOGENISIS WHICH
WILL BE CROSSING WESTERN KANSAS DURING THE OVERNIGHT HOURS.
BY EARLY WEDNESDAY THE MOISTURE AND LIFT AHEAD OF THE UPPER LEVEL
TROUGH APPEARS TO BE CONFINED TO PORTIONS OF SOUTH CENTRAL KANSAS.
THIS IS FORECAST TO BE QUICKLY SHIFTED EAST AND MODEL THIS MORNING
INDICATING SUBSIDENCE ALONG WITH SOME DRIER AIR RETURNING BEHIND
THIS UPPER LEVEL TROUGH BY LATE DAY. GIVEN CLEARING KANSAS DURING
THE AFTERNOON WILL STAY CLOSE TO THE LATEST GUIDANCE WITH HIGHS
CLIMBING BACK INTO THE 30S WEDNESDAY AFTERNOON. A WARMING TREND
CAN THEN BE EXPECTED THROUGH THE REMAINDER OF THE WEEK BASED ON
IMPROVING AND PERSISTENT DOWNSLOPE FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 513 AM CST SUN JAN 11 2015
IFR CEILINGS WILL ATTEMPT TO SPREAD INTO THE DDC AREA EARLY THIS
MORNING AS SOUTH/SOUTHEASTERLY WINDS DRAW MORE HUMID AIR IN THE
LOWER LEVELS ACROSS SOUTH CENTRAL KANSAS. AT THIS TIME ONLY THE
NAM SPREADS THESE IFR CEILINGS FAR ENOUGH WEST TO IMPACT DDC AND
HYS BETWEEN 15 AND 18Z. AS OF 11Z...BASED ON THE LATEST SATELLITE
LOOP AND SURFACE OBSERVATIONS WILL FAVOR THE SLOWER HRRR AND
KEEPING THE MAIN STATUS JUST SOUTHEAST OF DDC. A COLD FRONT WILL
MOVE ACROSS SOUTHWEST KANSAS TODAY AND AS THIS COLD FRONT PASSES
THE SOUTH WINDS WILL SHIFT TO THE NORTH AND INCREASE TO 10 TO 15
KNOTS. IN ADDITION TO THE NORTH/NORTHEAST WINDS THE LOWER LEVELS
OF THE ATMOSPHERE WILL SATURATE FROM THE SURFACE AROUND 1500FT
AGL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 11 23 11 / 0 0 0 10
GCK 44 11 23 11 / 0 0 0 10
EHA 49 16 26 16 / 0 0 0 10
LBL 44 15 24 14 / 0 0 0 10
HYS 39 8 20 9 / 0 0 0 10
P28 39 16 26 13 / 0 10 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJOHNSON
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
515 AM CST SUN JAN 11 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST SUN JAN 11 2015
OTHER THAN POTENTIAL FOR FOG DEVELOPMENT LATER THIS MORNING, THE
SHORT TERM FORECAST IS ONE OF FAIRLY BENIGN WEATHER. SOMEWHAT
RELATIVE UNCERTAINTY EXISTS WITH RESPECT TO TEMPERATURES AT LEAST
THIS AFTERNOON AS WELL. THE WEAK COLD FRONT POISED TO MOVE INTO THE
AREA LATER TONIGHT WAS POSITIONED ACROSS NORTHWEST KANSAS INTO
EASTERN NEBRASKA. LIGHT SOUTHWEST WILL PERSIST AHEAD OF THIS SURFACE
FEATURE TODAY. ALREADY THIS MORNING, THE DEW POINT DEPRESSIONS HAVE
FALLEN TO ONE TO THREE DEGREES AT LOCATIONS LIKE SCOTT CITY, TO
SYRACUSE AND GARDEN CITY, WHERE THE NAM WAS MOST PRONOUNCED IN
DEVELOPING FOG. THE MODEL TREND WAS TO DEVELOP THIS SURFACE
RADIATION FOG BETWEEN AROUND 11 TO 14 Z BEFORE AN
INSOLATION/VERTICAL MIXING INDUCED DISSIPATION. TEMPERATURES FOR THIS
AFTERNOON WILL ALSO BE A CHALLENGE AS THE MID LEVEL CLOUDS NOW
INCREASING ACROSS SOUTH CENTRAL KANSAS WILL INHIBIT INSOLATION AND
RESULTANT SURFACE HEATING LATER IN THE MORNING. TEMPERATURES WILL BE
WARMEST IN THE WEST THIS AFTERNOON. THE COLD FRONT WILL PLUNGE
THROUGH WESTERN KANSAS AROUND 00 UTC AS A MID LEVEL WAVE SHIFTS INTO
EASTERN KANSAS THIS EVENING. THE MODELS AND MOS OUTPUT INDICATE A
HIGH LEVEL OF AGREEMENT ON LOWS OVERNIGHT IN THE LOW SINGLE DIGITS
CWA-WIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CST SUN JAN 11 2015
MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH AN UPPER LEVEL
TROUGH, LOCATED AROUND 50N 140W AT 00Z SUNDAY, MOVING ACROSS THE
NORTHWESTERN UNITED STATES ON MONDAY. BY 12Z TUESDAY THIS UPPER
LEVEL SYSTEM WILL BE LOCATED AROUND THE FOUR CORNERS REGION. AS
THIS NEXT SYSTEM MOVES INTO THE FOUR CORNERS REGION ON MONDAY A
SURFACE RIDGE AXIS WILL BE CROSSING CENTRAL KANSAS AND MID TO HIGH
LEVEL MOISTURE WILL BEGIN TO SPREAD ACROSS WESTERN KANSAS. BASED
ON THE INCREASING CLOUD COVER AND NORTHEAST/EASTERLY FLOW OF COLD
AIR IN THE LOWER LEVELS ADVECTING INTO WESTERN KANSAS THE PREVIOUS
FORECAST STILL LOOKS ON TRACK WITH HIGHS MAINLY IN THE LOW TO MID
20S.
MONDAY NIGHT AND TUESDAY THE SURFACE WINDS WILL GRADUALLY VEER TO
THE SOUTH/SOUTHEAST AS THE SURFACE HIGH SLIDES EAST TOWARDS THE
MISSISSIPPI VALLEY. AS THE SOUTH/SOUTHEASTERLY FLOW DEVELOPS THE
0-1KM AGL DEWPOINTS WILL BEGIN TO SLOWLY INCREASE ACROSS FAR
WESTERN/SOUTHWEST KANSAS AND WARM AIR ADVECTION WILL BEGIN TO
DEVELOP. 800MB TO 500MB MOISTURE IS ALSO FORECAST TO CONTINUE TO
INCREASE ACROSS THE CENTRAL HIGH PLAINS AS THE UPPER LEVEL TROUGH
MOVES EAST TOWARDS THE CENTRAL ROCKIES. AT THIS TIME PRECIPITATION
CHANCES THROUGH MID DAY ON TUESDAY APPEARS SMALL GIVEN THE LIMITED
LOW LEVEL MOISTURE AND LIFT, EVEN FROM THE MORE AGGRESSIVE NAM AND
ECMWF. BY TUESDAY AFTERNOON SOME LIGHT SNOW WILL BE POSSIBLE
ACROSS PORTIONS OF WESTERN GIVEN THE INCREASING MOISTURE AND LIFT
IN THE 900MB TO 800MB LEVEL FROM THE NAM AND ECMWF. THIS
PRECIPITATION WILL THEN SPREAD NORTH AND EAST THROUGH THE
OVERNIGHT HOURS AS 700MB FRONTOGENESIS IMPROVES AHEAD OF THE UPPER
LEVEL TROUGH/LOW WHICH WILL BE MOVING EAST ACROSS NEW MEXICO AND
COLORADO TUESDAY NIGHT. CONFIDENCE ON SNOWFALL AMOUNTS STILL
REMAIN LOW ACROSS WESTERN KANSAS THIS MORNING GIVEN THE CURRENT
DISCREPANCIES BETWEEN THE MODELS CONCERNING MOISTURE AND LIFT,
EVEN WITH THE ENHANCED LIFT FROM THE 700MB FRONTOGENISIS WHICH
WILL BE CROSSING WESTERN KANSAS DURING THE OVERNIGHT HOURS.
BY EARLY WEDNESDAY THE MOISTURE AND LIFT AHEAD OF THE UPPER LEVEL
TROUGH APPEARS TO BE CONFINED TO PORTIONS OF SOUTH CENTRAL KANSAS.
THIS IS FORECAST TO BE QUICKLY SHIFTED EAST AND MODEL THIS MORNING
INDICATING SUBSIDENCE ALONG WITH SOME DRIER AIR RETURNING BEHIND
THIS UPPER LEVEL TROUGH BY LATE DAY. GIVEN CLEARING KANSAS DURING
THE AFTERNOON WILL STAY CLOSE TO THE LATEST GUIDANCE WITH HIGHS
CLIMBING BACK INTO THE 30S WEDNESDAY AFTERNOON. A WARMING TREND
CAN THEN BE EXPECTED THROUGH THE REMAINDER OF THE WEEK BASED ON
IMPROVING AND PERSISTENT DOWNSLOPE FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 513 AM CST SUN JAN 11 2015
IFR CEILINGS WILL ATTEMPT TO SPREAD INTO THE DDC AREA EARLY THIS
MORNING AS SOUTH/SOUTHEASTERLY WINDS DRAW MORE HUMID AIR IN THE
LOWER LEVELS ACROSS SOUTH CENTRAL KANSAS. AT THIS TIME ONLY THE
NAM SPREADS THESE IFR CEILINGS FAR ENOUGH WEST TO IMPACT DDC AND
HYS BETWEEN 15 AND 18Z. AS OF 11Z...BASED ON THE LATEST SATELLITE
LOOP AND SURFACE OBSERVATIONS WILL FAVOR THE SLOWER HRRR AND
KEEPING THE MAIN STATUS JUST SOUTHEAST OF DDC. A COLD FRONT WILL
MOVE ACROSS SOUTHWEST KANSAS TODAY AND AS THIS COLD FRONT PASSES
THE SOUTH WINDS WILL SHIFT TO THE NORTH AND INCREASE TO 10 TO 15
KNOTS. IN ADDITION TO THE NORTH/NORTHEAST WINDS THE LOWER LEVELS
OF THE ATMOSPHERE WILL SATURATE FROM THE SURFACE AROUND 1500FT
AGL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 11 23 11 / 0 0 10 10
GCK 43 11 23 11 / 0 0 10 10
EHA 49 16 26 16 / 0 0 10 10
LBL 44 15 24 14 / 0 0 10 10
HYS 39 8 20 9 / 0 0 10 10
P28 39 16 26 13 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
400 AM MST SUN JAN 11 2015
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 400 AM MST SUN JAN 11 2015
TODAY-TONIGHT...LOOKS LIKE THE DAY WILL START OFF WITH SOME HIGH
CLOUDS GENERALLY NEAR THE KS/NE BORDER BUT AS THE DAY PROGRESSES MID
CLOUDS MOVE IN FROM THE NORTHWEST. LOW LEVELS OF THE ATMOSPHERE
REMAIN RATHER DRY SO NO PRECIPITATION EXPECTED. DURING THE OVERNIGHT
HOURS MODELS SUGGESTING A WEAK WEATHER DISTURBANCE PER 700-500MB
MOISTURE TO MOVE ALONG AND JUST SOUTH OF THE PALMER DIVIDE
BRINGING A SLIGHT CHANCE OF LIGHT SNOW TO PARTS OF FAR EASTERN
COLORADO...BEST CHANCE FOR CHEYENNE AND KIT CARSON COUNTIES. FOR
REMAINING AREAS GENERALLY ALONG/WEST OF THE CO/KS BORDER 850-700MB
MOISTURE SATURATES BUT MID LEVEL MOISTURE A BIT LACKING SO HAVE
KEPT SOME SMALL CHANCES FOR FLURRIES.
BIGGER CHALLENGE TODAY IS HIGH TEMPERATURES. MOST OF THE MODELS HAVE
BEEN WAY TOO COOL/COLD THE PAST SEVERAL DAYS EXCEPT FOR A FEW. HAVE
RELIED ON THOSE BETTER PERFORMING MODELS FOR THIS FORECAST AS TIMING
OF COLD FRONT AND ARRIVAL OF LEADING EDGE OF ARCTIC AIR WILL BE
CRITICAL. 18Z 850MB TEMPS SEVERAL DEGREES ABOVE 0F AND THROUGH 21Z
STILL ABOVE ZERO FOR ALL BUT THE NORTHERN EDGE OF YUMA COUNTY. BY
00Z THE COLD PUSH REACHES INTERSTATE 70. AFTER SEEING THE 9Z RUC AND
LATEST HRRR (WHICH DID RATHER WELL WITH SATURDAYS TEMPERATURES) HAVE
FINALIZED HIGHS IN THE MID/UPPER 30S ALONG/NORTH OF THE KS/NE BORDER
WITH 40S TO THE SOUTH. HAVE AROUND 50 IN THE TRIBUNE AREA. 1040MB
SFC HIGH REACHES THE AREA TONIGHT LOWS TONIGHT 5-10F ACROSS THE
NORTHEAST 1/2 OF THE AREA WITH 10-15F TO THE SOUTHWEST.
MONDAY-MONDAY NIGHT...1043MB SFC HIGH NOSING INTO THE AREA DURING
THE MORNING THEN WEAKENING JUST A BIT. SHOULD SEE SOME LINGERING
LIGHT SNOW ACROSS MOST OF FAR EASTERN COLORADO IN THE MORNING BEFORE
MID LEVEL MOISTURE MOVES AWAY LEAVING THE AREA UNDER PLENTY OF
CLOUDS. FOR THE OVERNIGHT HOURS WE ARE IN BETWEEN DEPARTING SYSTEM
AND APPROACHING UPPER TROUGH AND NEXT BATCH OF MOISTURE WITH SHORT
WAVE RIDGING OVER THE AREA. MID LEVEL MOISTURE LACKING FOR ANY
PRECIP SO JUST MOSTLY CLOUDY/CLOUDY CONDITIONS EXPECTED. HIGH
TEMPERATURES ONLY IN THE MID TEENS TO LOW 20S (NORTHEAST TO
SOUTHWEST ORIENTATION ACROSS THE AREA) WITH OVERNIGHT LOWS GENERALLY
5F-13F.
TUESDAY-TUESDAY NIGHT...AROUND SUNRISE BASE OF UPPER TROUGH EXPECTED
OVER SALT LAKE CITY AREA CLOSING OFF WHILE MOVING SOUTHEAST TOWARD
NORTHWEST NEW MEXICO/FOUR CORNERS AREA. DURING THE OVERNIGHT HOURS
WEAKEN THE LOW A BIT WHILE ALSO PUSHING IT EAST/SOUTHEAST.
FORECAST ISSUE FOR THE PERIOD IS TIMING AND PLACEMENT OF
PRECIPITATION CHANCES. MODELS IN GENERAL AGREE ON BRINGING
INCREASING MOISTURE TO THE AREA FROM THE WEST/SOUTHWEST DURING THE
DAY WITH A BIT OF DIFFERING SOLUTIONS AS TO WHETHER OR NOT SOME
DRIER AIR MOVES IN FROM THE NORTHWEST. NAM SAYS NO WHILE GFS/ECMWF
SAY YES. SO FOR NOW VERY LITTLE CHANGE MADE TO FORECAST. GFS/ECWMF
IN BETTER AGREEMENT BRINGING DRIER IN FROM THE NORTHWEST DURING THE
NIGHT WHICH IS SIMILAR TO LAST NIGHTS SOLUTIONS. SO FOR NOW...NO
CHANGES MADE.
TEMPERATURES WILL CONTINUE TO BE COLD WITH HIGH TEMPERATURES IN THE
LOW TO MID 20S AND LOWS GENERALLY 10-15F...COLDEST AROUND MCCOOK
WITH HIGHEST VALUES FROM FLAGLER TO LEOTI.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 211 AM MST SUN JAN 11 2015
FORECAST CHALLENGES ARE RESOLVING THE WARMING TEMPERATURES AND
PERSISTENT WEST TO EAST/WARM TO COOL GRADIENT ACROSS THE FORECAST
AREA.
THE UPPER TROUGH THAT MOVED THROUGH THE CENTRAL HIGH PLAINS REGION
LATE TUESDAY AND TUESDAY NIGHT MOVES OUT OF THE REGION WEDNESDAY.
NORTHWEST FLOW WILL BE IN PLACE WEDNESDAY NIGHT AND THURSDAY AS THE
UPPER RIDGE MOVES OVER THE ROCKIES AND HIGH PLAINS. COLD AIR AT THE
SURFACE IS SWEPT OUT OF THE CENTRAL HIGH PLAINS AS THE HIGH PRESSURE
AREA MOVES EAST AND A LEE TROUGH DEEPENS NEAR THE EASTERN COLORADO
BORDER.
DIFFERENCES ARE SHOWING UP BETWEEN THE GFS AND ECMWF OVER THE
CENTRAL HIGH PLAINS REGION THURSDAY NIGHT AND FRIDAY. THE ECMWF IS
PRODUCING TWO SEPARATE WEAKER SHORT WAVE TROUGHS THAT MOVE ACROSS
THE FORECAST AREA WHILE THE GFS IS PRODUCING A STRONGER CLOSED LOW
CENTER THAT FITS INTO THE TIMING OF THE SECOND OPEN WAVE
IDENTIFIED BY THE ECMWF FRIDAY AFTERNOON AND EVENING. MAY END UP
JUST SEEING AN INCREASE IN HIGH CLOUDS ASSOCIATED WITH THE WAVE ON
FRIDAY...BUT EXTENDED BLEND MAY BE TOO DRY AS IT HAS VERY LITTLE
CLOUD COVER IN FORECAST BEYOND WEDNESDAY WITH OVERALL DRY
CONDITIONS AND TEMPERATURES WARMING THROUGH THE END OF THE WEEK
WITH RIDGING ALOFT EXPECTED ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 400 AM MST SUN JAN 11 2015
KGLD...VFR CONDITIONS THROUGH 22Z WITH WINDS VARIABLE AT 5KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH A GRADUAL
INCREASE IN CLOUDS STARTING MID TO LATE MORNING. AROUND 23Z
STRATUS STARTS TO APPROACH THE TERMINAL AS WINDS BECOME NORTHERLY
AROUND 10KTS. ITS EXPECTED THAT FROM 00Z THROUGH 11Z STRATUS WILL
COVER THE TERMINAL WITH VLIFR CIGS. SHORTLY AFTER 11Z STRATUS
CONCENTRATION SHIFTS TO THE WEST POSSIBLY ALLOWING VFR CONDITIONS
TO RETURN WITH NORTHEAST WINDS AROUND 10KTS. SOME SNOW FLURRIES
ARE POSSIBLE AT THE TAIL END OF THE PERIOD.
KMCK...VFR CONDITIONS THROUGH 20Z WITH WINDS VARIABLE AT 3KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH AN INCREASE IN
MID AND HIGH CLOUDS MID TO LATE MORNING. AROUND 21Z STRATUS
APPROACHES THE TERMINAL FROM THE NORTH WITH WINDS SHIFTING TO THE
NORTHEAST AROUND 5KTS. BY 23Z IF NOT AN HOUR OR POSSIBLY TWO
EARLIER VLIFR CIGS EXPECTED WITH NORTH WINDS AROUND 10KTS. THESE
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 06Z-07Z BEFORE
RETURNING TO VFR AS THE SATURATED LOW LEVEL AIRMASS MOVES
WEST/SOUTHWEST OF THE TERMINAL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...LOCKHART
AVIATION...99
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
101 AM EST SUN JAN 11 2015
.UPDATE...
ISSUED AT 101 AM EST SUN JAN 11 2015
A LARGE AREA OF MID-LEVEL CLOUDS ARE MOVING IN FROM WESTERN KENTUCKY.
THESE WILL LIKELY MAKE IT INTO LOCATIONS WEST OF I-75 BEFORE
DAWN...LIKELY RESULTING IN TEMPERATURES RECOVERING SOMEWHAT OFF OF
THEIR OVERNIGHT LOWS. WILL FRESHEN UP THE FORECAST TO ACCOUNT FOR
THESE TRENDS.
UPDATE ISSUED AT 1043 PM EST SAT JAN 10 2015
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT TRENDS IN OBSERVATIONS.
THIS ALLOWED FOR SLIGHTLY LOWER MIN T IN SOME OF THE EASTERN AND
NORTHEASTERN VALLEYS AND IN THE EKQ AREA. OVERALL...NO SIGNIFICANT
CHANGES WERE NEEDED AT THIS TIME.
UPDATE ISSUED AT 725 PM EST SAT JAN 10 2015
ANOTHER CHILLY NIGHT IS IN STORE...ESPECIALLY IN THE VALLEYS...AS SFC
HIGH PRESSURE BEGINS TO DEPART TO THE EAST TONIGHT. THIS SHOULD SET
THE STAGE FOR A MODERATE RIDGE VALLEY SPLIT ON THE ORDER OF 8 TO 11
DEGREES. THE NORMALLY COLDER EASTERN SPOTS IN NE KY AND NEAR THE WV
AND VA BORDERS MIGHT REACH THE SINGLE DIGITS. ATTM...ONLY SOME
ADJUSTMENTS WERE MADE TO HOURLY TEMP AND DEWPOINT GRIDS BASED ON
RECENT OBSERVATIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 340 PM EST SAT JAN 10 2015
19Z SFC ANALYSIS SHOWS MODIFIED ARCTIC HIGH PRESSURE OVER EASTERN
KENTUCKY. THIS HAS KEPT THE SKIES CLEAR AND WINDS LIGHT TODAY
THROUGHOUT THE AREA...HELPING TO SEND TEMPERATURES INTO THE UPPER
20S AND LOWER 30S FOR MOST OF THE CWA...DESPITE AN AWFULLY CHILLY
START. READINGS AT 3 PM RANGE FROM 25 DEGREES JUST NORTH OF FLEMING
COUNTY TO 34 DEGREES IN BELL AND HARLAN COUNTIES. DEWPOINTS...
MEANWHILE...ARE GENERALLY IN THE LOW SINGLE DIGITS ABOVE ZERO.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE RETREAT OF THE DEEP
TROUGH RESPONSIBLE FOR THIS LATEST COLD BLAST TONIGHT AND THE
APPROACHING OF A WEAKER SOUTHERN STREAM TROUGH INTO SUNDAY NIGHT.
HEIGHTS WILL SLOWLY RISE FROM TONIGHT INTO THE DAY SUNDAY THOUGH
MORE ENERGY WILL START TO STREAM IN FROM THE SOUTHERN STREAM LATER
SUNDAY THROUGH SUNDAY NIGHT. WITH THE GOOD MODEL AGREEMENT HAVE
FOLLOWED THE HRRR AND NAM12 MOST CLOSELY FOR THIS SHORT TERM PORTION
OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE ANOTHER CHILLY NIGHT...BUT MILDER THAN
LAST NIGHT...UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS WILL SET
THE STAGE FOR A DECENT RIDGE TO VALLEY TEMPERATURE DIFFERENCE THROUGH
THE NIGHT. TEMPS WILL REBOUND THROUGH THE DAY SUNDAY EVEN AS CLOUDS
QUICKLY INCREASE AND THICKEN FROM THE WEST. WHILE READINGS ARE
EXPECTED TO RISE ABOVE FREEZING FOR THE ENTIRE CWA BEFORE THE CHANCES
OF LIGHT RAIN MOVE IN...THE DRY AIR IN PLACE MAY RESULT IN A MIXTURE
OF RAIN AND SLEET INITIALLY ALONG AND NORTH OF INTERSTATE 64. IN
ADDITION...THOUGH AIR TEMPERATURE WILL BE A COUPLE OF DEGREES ABOVE
FREEZING...PATCHY FREEZING RAIN WILL BE POSSIBLE DUE TO SUB FREEZING
ROAD TEMPERATURES AND SHADED LOCATIONS. ACCORDINGLY...HAVE ADDED A
TOUCH OF FREEZING RAIN TO THE WX GRIDS FROM LATE SUNDAY AFTERNOON
THROUGH EARLY EVENING. THEREAFTER...RAIN WILL BE THE PCPN TYPE
THROUGH THE REST OF THE NIGHT AS THE FIRST IN A SERIES OF LOW
PRESSURE WAVES RIDES THROUGH THE OHIO VALLEY. TEMPERATURES SHOULD BE
STEADY OR SLOWLY RISE THROUGH THE NIGHT. WILL ISSUE AN SPS TO ADDRESS
THE WINTRY MIX POTENTIAL FOR NORTHERN PARTS OF THE AREA LATE SUNDAY.
ONCE AGAIN USED THE BCCONSSHORT/SUPERBLEND AS A STARTING POINT FOR
THE T...TD...AND WIND GRIDS WITH SOME MODERATE TERRAIN BASED POINT
ADJUSTMENTS FOR LOWS TONIGHT. AS FOR POPS...ENDED UP IN LINE WITH THE
MET MOS THROUGH THE SHORT TERM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 240 PM EST SAT JAN 10 2015
WHILE CONFIDENCE IS HIGH TO START THE UPCOMING WEEK...CONFIDENCE
FADES AS WE HEAD INTO TUESDAY AND BEYOND AS QUESTIONS SWIRL WITH
JUST HOW FAR SOUTH A FRONTAL BOUNDARY STALLS...WHICH IN TURN WILL
DETERMINE JUST HOW ACTIVE AND WHAT TYPE OF PRECIPITATION WE DEAL
WITH THROUGH THURSDAY.
TO START THE PERIOD...A SHORTWAVE TROUGH WILL BE PUSHING ACROSS THE
AREA MONDAY...YIELDING A DAMP DAY WITH PERIODS OF RAIN AND DRIZZLE.
LIFT AND MOISTURE ARE ALL PRESENT TO SUPPORT CATEGORICAL POPS
THROUGH MOST OF THE DAY. BY MONDAY NIGHT...DEEPER MOISTURE WILL EXIT
TO THE SOUTH AND EAST AS A COLD FRONT PUSHES SOUTH. HOWEVER...MODEL
SOUNDINGS REMAIN SUPPORTIVE OF PERSISTENT PERIOD OF DRIZZLE THROUGH
MONDAY NIGHT AND INTO TUESDAY. AT THE SAME TIME...SHALLOW COLD AIR
WILL BE SPREADING SOUTH BEHIND THE COLD FRONT. THIS WILL SET UP THE
STAGE FOR SOME LIGHT FREEZING RAIN/DRIZZLE INTO TUESDAY MORNING.
FORECAST CONFIDENCE ERODES ON TUESDAY...AS GFS KEEPS THE BOUNDARY
FARTHER NORTH...KEEPING THE THREAT OF PRECIPITATION AROUND FOR MUCH
OF SOUTHEAST KENTUCKY THROUGH THE DAY. ON THE OTHER HAND...THE ECMWF
SINKS THE FRONT SOUTHWARD AND KEEPS THE AREA DRY THROUGH TUESDAY AND
BEYOND. SIMPLY CANNOT DISCOUNT THE GFS SOLUTION...SO WILL KEEP SOME
LOW POPS AROUND THROUGH TUESDAY. AS TEMPERATURES ARE NOT EXPECTED TO
CLIMB PAST FREEZING...ANY PRECIPITATION THAT DOES EXIST COULD POSE
PROBLEMS THROUGH THE DAY. HOWEVER...GFS DOES SHOW SOME MID LEVEL
MOISTURE SPREADING BACK OVERHEAD...POSSIBLY SUPPORTING FEEDER/SEEDER
PROCESSES BY LATE MORNING INTO THE AFTERNOON HOURS. AT THE SAME
TIME...STILL A BIT OF A WARM NOSE ON THE GFS SOUNDINGS THROUGH THE
DAY...SO ANY SEEDER FEEDER PROCESSES COULD JUST INCREASE THE
INTENSITY OF ANY FREEZING RAIN. HOWEVER...ANY SLIGHT CHANGES IN THE
LOWER TEMPERATURE PROFILE ON TUESDAY WOULD SIGNIFICANT ALTER
PRECIPITATION TYPE. THUS...PLANNING TO GO FAIRLY LIBERAL ON THE
PRECIPITATION TYPES THIS FAR OUT AND GO WITH A MIXTURE OF
SLEET/FREEZING RAIN/AND POSSIBLY SOME SNOW ENTERING THE PICTURE ON
TUESDAY.
BY TUESDAY NIGHT INTO THURSDAY...THE QUESTIONS REMAIN ON HOW FAR
NORTH PRECIPITATION CHANCES WILL LAST. THE ECMWF REMAINS LESS
OPTIMISTIC ON ANY PRECIPITATION CHANCES...WHILE THE GFS KEEPS SOME
CHANCES IN SOUTHEAST KENTUCKY THROUGH THURSDAY. GIVEN THE MODELS
DISAGREEMENT HAVE OPTED FOR SOME LOW POPS THROUGH THURSDAY ACROSS
SOUTHEAST KENTUCKY. IF PRECIPITATION OCCURS...THE THREAT FOR
FREEZING DRIZZLE...SNOW...AND RAIN WILL CONTINUE. THUS...THERE IS A
CHANCE FOR A AN EXTENDED PERIOD OF FROZEN PRECIPITATION IN SOUTHEAST
KENTUCKY. ALL MODELS ARE TRENDING DRIER BY LATE THURSDAY INTO NEXT
WEEKEND...SO WILL DRY OUT THE FORECAST FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 101 AM EST SUN JAN 11 2015
BESIDES SOME MID-LEVEL CLOUD COVER MOVING IN FROM THE WEST TOWARDS
DAWN...VFR CONDITIONS WILL HOLD ON THROUGH THE DAY. LIGHT
PRECIPITATION WILL THREATEN LOCATIONS FROM WEST TO EAST IN THE
AFTERNOON AND ESPECIALLY INTO THE EVENING HOURS. CEILINGS WILL LIKELY
LOWER TO MVFR BETWEEN 00 AND 06Z. WINDS WILL GENERALLY BE FROM THE
SOUTH AT AROUND 5 KTS OR LESS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
334 PM EST SUN JAN 11 2015
.SYNOPSIS...
ARCTIC HIGH PRESSURE WILL SHIFT OFF THE EAST COAST TONIGHT. A WEAK COLD
FRONT WILL CROSS THE AREA ON MONDAY. HIGH PRESSURE WILL BUILD NORTH
THROUGH MIDWEEK BEFORE LOW PRESSURE MOVES OFF THE CAROLINA COAST
THURSDAY NIGHT. HIGH PRESSURE THEN PREVAILS INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH MONDAY/...
CLOUDS CONTINUE TO INCREASE THIS AFTERNOON AND EVENING AHEAD OF
APPROACHING SOUTHERN STREAM STORM SYSTEM. TEMPERATURES ABOVE
FREEZING IN MOST LOCATIONS AND MAY BE SLOW TO FALL EARLY THIS
EVENING.
THE PRIMARY CONCERN OF THE SHORT TERM FORECAST IS THE POTENTIAL FOR
A LIGHT ICING EVENT ACROSS MOST IF NOT THE ENTIRE AREA LATE TONIGHT
AND EARLY MONDAY MORNING. THE ONE CRITICAL ELEMENT OF THE FORECAST
WILL BE THE SFC TEMPERATURES. NOT MUCH CHANGE IN THE THERMAL PROFILE
ALOFT...AS A WARM NOSE GREATER THAN 3C WILL BE IN PLACE ACROSS MOST
OF THE AREA BY THE TIME PRECIP STARTS. SOME SLEET MAY MIX IN AT THE
ONSET ACROSS THE NORTHERN THIRD OF THE AREA BUT THIS SHOULD BE SHORT
LIVED. ADMITTEDLY IT IS DISCONCERTING TO SEE THE SPREAD IN SFC TEMPS
AND THE MODELS TRYING TO HANG ON TO ABOVE FREEZING AIR. THIS IS NOT
TOTALLY UNEXPECTED SINCE THE SFC HIGH OFF THE COAST WILL NOT SUPPORT
A CLASSIC CAD AND THERE WILL NOT BE COLD AIR REPLENISHMENT FROM THE
NORTHEAST. WE WILL HAVE TO RELY ON AN IN-SITU CAD EVENT/WET BULB
PROCESSES TO TAKE PLACE...AND THIS DOES SUPPORT TEMPS FALLING BELOW
FREEZING ACROSS MOST OF THE AREA FOR AT LEAST SEVERAL HOURS
OVERNIGHT. THE FIRST PLACES TO RISE ABOVE FREEZING (ASSUMING THEY
FALL BELOW) WILL BE THE HIGHER ELEVATIONS (THE WARM NOSE WILL WORK
DOWN TO THEM FIRST) AND THE COASTAL PLAIN (THE SOUTHERLY FLOW WILL
PREVENT TEMPERATURES FROM STAYING COLD). IN ADDITION TO A COLDER
START FROM THIS AFTERNOON...THE PRECIP-INDUCED COOLING WILL HAVE A
HARDER TIME SCOURING OUT OF NORTHERN MD...THE EASTERN WV
PANHANDLE...AND PERHAPS FAR NORTHERN VA. IN THIS AREA WE HAVE THE
HIGHEST CONFIDENCE OF ACCUMULATING ICE.
PRECIP START TIME IS SHOWING SOME VARIATION IN THE MODELS...WITH
RECENT HRRR AND RAP RUNS WELL AFTER MIDNIGHT. DIDN/T MAKE MUCH
CHANGE TO THE GOING FORECAST POPS AS THE MAJORITY OF THE MODELS
STILL WARRANT POPS INCREASING JUST PRIOR TO MIDNIGHT. HOWEVER
WIDESPREAD PRECIP MAY NOT START UNTIL AFTER 09Z.
ICE ACCUMULATIONS SHOULD BE LIGHT GIVEN THE TEMPERATURES NEAR
FREEZING BUT AS NOTED ABOVE...THE HIGHEST AMOUNTS ARE EXPECTED
CLOSER TO THE MD/PA BORDER. HAVE CAPPED THESE AROUND 0.1 INCH...BUT
A FEW HIGHER REPORTS ARE POSSIBLE. OTHER AREAS WILL PROBABLY BE
LESS...BUT TEMPS/PRECIP RATES WILL HAVE TO BE MONITORED. ANOTHER
ISSUE TO CONSIDER IS THE AMBIENT COLD GROUND AFTER THE RECENT COLD
SPELL. COULD SEE ACCRETION OCCUR EVEN WITH AIR TEMPS SLIGHTLY ABOVE
FREEZING. TYPICALLY SHADED SPOTS AND BRIDGES WOULD BE A GREATER
CONCERN FOR THE GROUND ACCUMULATIONS. IMPORTANTLY...FZRA WILL LIKELY
BE AFFECTING MUCH OF THE AREA DURING THE MORNING COMMUTE. THEREFORE
HAVE ISSUED A FREEZING RAIN ADVISORY FOR THE ENTIRE AREA. IT WILL
RUN THROUGH 9 AM FOR MOST OF THE AREA EXCEPT THE COLDER LOCATIONS
MENTIONED ABOVE WHERE IT WILL BE IN EFFECT UNTIL 1 PM. THESE TIMES
MAY BE A LITTLE LENGTHY FOR SOME LOCATIONS...BUT WANTED TO
INCORPORATE UNCERTAINTY AND UNEVEN DISTRIBUTION OF THE TEMPERATURE
CURVE.
THE PRECIP WILL BE ALL RAIN DURING THE AFTERNOON AND BEGIN TO TAPER
OFF FROM WEST TO EAST. A STRONGER LLJ WILL MEAN PLENTY OF FORCING
AND MOISTURE FOR A GENERALLY STEADY RAIN...IN ADDITION TO HELPING
ELIMINATE ANY INVERSION AND THE TEMPERATURES RISE. MID 40S WILL BE
POSSIBLE IN THE SOUTHERN PART OF THE AREA...WITH THE NORTH STUCK IN
THE MID 30S.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
ANOTHER SURGE OF ARCTIC AIR WILL POUR INTO THE MIDDLE ATLANTIC
REGION MONDAY NIGHT. TEMPERATURES WILL DROP INTO THE TEENS IN MOST
AREAS WITH LOWER 20S IN THE BALTIMORE AND WASHINGTON DC METRO.
COLD HIGH PRESSURE WILL BUILD IN FOR TUESDAY AND TEMPERATURES WILL
NOT RISE ALL THAT MUCH DESPITE SUNSHINE. HIGH TEMPERATURES WILL ONLY
REACH THE MIDDLE TO UPPER 20S IN MOST LOCATIONS...PERHAPS LOW 30S
OVER SOUTHERN PORTIONS OF THE AREA. DRIER AIR WILL ALSO FILSTER IN
WITH THE HIGH PRESSURE RIDGE. HAVE REMOVED POPS FOR ALL AREAS
DURING THE DAY. ANOTHER COLD NIGHT EXPECTED TUESDAY NIGHT WITH
LOWS IN THE TEENS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE LONG TERM WILL BEGIN WITH THE MID-ATLANTIC IN A WEAK CAD
SITUATION DUE TO ELONGATED TROUGHING TO OUR NORTH...STRETCHING FROM
THE GREAT LAKES TO NEW ENGLAND...AND A BROAD AREA OF TROUGHING
LOCATED ALONG AND OFF THE SOUTHEAST COAST TO OUR SOUTH. WHILE MOST
OF THE PRECIPITATION ASSOCIATED WITH THE TROUGHING SHOULD STAY TO
OUR SOUTH THROUGH MIDWEEK...A WEAK SHORTWAVE CROSSING THE AREA DURING THE
DAYTIME WEDNESDAY WILL PROVIDE THE BEST CHANCE FOR PRECIP TO REACH
THE CWA. THUS CHANCE POPS MAINLY CONFINED TO THE SOUTHEASTERN SECTOR
OF THE CWA WEDNESDAY THROUGH THURSDAY. COLD AIR IN PLACE AT THE
SURFACE AND LACK OF STRONG WARM NOSE IN THE MID-LEVELS SHOULD ENSURE
THAT ANY PRECIP THAT DOES FALL WILL BE IN THE FORM OF SNOW...WITH
THE EXCEPTION OF THE FAR SOUTHERN PORTION OF THE CWA WHERE TEMPS
SHOULD BE WARM ENOUGH DURING THE DAYTIME THURSDAY TO PRODUCE PLAIN
RAIN. POPS CURRENTLY TOO LOW TO EXPECT ANY ACCUMULATION.
BROAD HIGH PRESSURE WILL BEGIN TO BUILD IN WEDNESDAY NIGHT BEFORE
ENCOMPASSING THE ENTIRE EASTERN CONUS BY FRIDAY NIGHT. UPPER LEVEL
RIDGING DURING THIS SAME TIME WILL LEAD TO PLENTY OF SUNSHINE AND
NEAR NORMAL TEMPS. WEAK SOUTHERLY FLOW WILL BEGIN TO DEVELOP AS THE
HIGH MOVES OFF THE COAST SATURDAY NIGHT AND SUNDAY WILL BRING ABOVE
NORMAL TEMPS IN LIGHT SOUTHERLY FLOW.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
CLOUDS WILL CONTINUE TO LOWER LATE THIS AFTERNOON AND EVENING AHEAD
OF AN APPROACHING LOW PRESSURE SYSTEM. PRECIP WILL BEGIN AROUND
MIDNIGHT...WITH IFR CONDITIONS GRADUALLY DEVELOPING BY DAYBREAK.
COULD BE LOWER AT TIMES. A PERIOD OF FZRA IS LIKELY AT THE
TERMINALS...BUT TEMPERATURES WILL BE VERY CLOSE TO FREEZING. IAD/MRB
HAVE THE GREATEST CHANCE AT A PROLONGED PERIOD OF ICING. THE THREAT
FOR ICING WILL DECREASE BETWEEN 12-15Z...WITH RAIN EXPECTED INTO THE
AFTERNOON AND CONTINUED IFR OR LOWER CONDITIONS. SOME IMPROVEMENT
POSSIBLE BY LATE AFTERNOON AS PRECIP TAPERS OFF. A COLD FRONT WILL
PASS THROUGH LATE IN THE DAY AND SHIFT LIGHT WINDS FROM S TO NW.
VFR CONDITIONS ARE EXPECTED TUESDAY INTO TUESDAY NIGHT. CONFIDENCE
IS LOW IN THE OCCURRENCE OF AVIATION HAZARDS THROUGH THE LONG TERM
PERIOD.
&&
.MARINE...
LIGHT SOUTHERLY WINDS WILL CONTINUE THROUGH TONIGHT AND MOST OF
MONDAY. AS A LOW PRESSURE SYSTEM APPROACHES THE WATER. PRECIPITATION
WILL MOVE IN LATE TONIGHT AND LAST THROUGH MONDAY. A PERIOD OF
FREEZING RAIN IS POSSIBLE...BUT A MAJORITY OF THE EVENT WILL BE
PLAIN RAIN ON THE WATERS. A COLD FRONT WILL MOVE THROUGH LATE IN THE
DAY AND SHIFT WINDS TO THE NW.
SMALL CRAFT CONDITIONS MAY BE POSSIBLE TUESDAY INTO TUESDAY NIGHT
ON ALL WATERS. A SMALL CRAFT ADVISORY MAY ALSO BE NECESSARY INTO
THE DAY WEDNESDAY WITH BREEZY NORTHERLY WINDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR DCZ001.
MD...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR MDZ011-013-014-016>018-504-506-508.
FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
MONDAY FOR MDZ003>006-501>503-505-507.
VA...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR VAZ025>031-036>040-050>057-501>504-506>508.
FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
MONDAY FOR VAZ505.
WV...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR WVZ050-055-501>506.
FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
MONDAY FOR WVZ051>053.
MARINE...NONE.
&&
$$
SYNOPSIS...KRW
NEAR TERM...ADS
SHORT TERM...KRW
LONG TERM...CEB
AVIATION...ADS/CEB/KRW
MARINE...ADS/CEB/KRW
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
432 AM EST SUN JAN 11 2015
.SYNOPSIS...
TEMPERATURES WILL MODERATE TODAY FOLLOWED BY A WINTRY MIX OF
PRECIPITATION TONIGHT INTO MONDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
HIGH CLOUDS HAVE ENCOMPASSED MOST OF THE NORTHERN TWO-THIRDS OF
THE CWA THROUGH THE NIGHT. THIS HAS KEPT TEMPERATURES FROM
CRATERING TOO BAD ACROSS PENNSYLVANIA AND OHIO...HOWEVER TO THE
SOUTH...TEMPERATURES HAVE FALLEN OFF QUITE DECIDEDLY. IN
FACT...ACROSS THE NORTHERN TWO-THIRDS OF THE AREA...TEMPERATURES
HAVE MANAGED TO RECOVER A FEW DEGREES FROM EARLIER OVERNIGHT LOWS.
THAT SAID...DRASTIC CHANGES IN THE MOISTURE AND THERMODYNAMIC
PROFILES ACROSS THE CWA ARE IN STORE OVER THE NEXT 24 TO 36 HOURS
THAT WILL LIKELY HAVE FAR REACHING IMPACTS UPON TRAVEL AND
COMMERCE FOR MOST OF THE UPPER OHIO VALLEY.
MODEL SOLUTIONS HAVE BEEN LARGELY LATCHING ONTO A SYSTEM MOVING
THROUGH THE AREA THIS EVENING INTO MONDAY FOR SEVERAL DAYS. THE
OVERNIGHT MODEL RUNS WERE LITTLE CHANGED FROM THIS...HOWEVER THE
THERMODYNAMIC PROFILES THAT HAVE COME OUT OF THE MORE RECENT NAM
AND SREF ENSEMBLE RUNS HAVE BECOME MORE PROBLEMATIC FOR MUCH OF
THE FORECAST AREA. ADDITIONALLY...THE HRRR IS POINTING IN A
DIRECTION THAT MAKES THIS FORECASTER TAKE PAUSE DUE TO A WARMER
BOUNDARY LAYER THAN IN PREVIOUS RUNS. THESE WARMER SOLUTIONS WOULD
GENERALLY BE A SEEMINGLY GOOD THING TO SEE FROM THE
MODELS...HOWEVER THERE ARE A LOT OF THINGS THAT MAKE SEEING WARM
LAYERS IN THE MODELS HIGHLY PROBLEMATIC GOING FORWARD.
FIRST...OVERNIGHT LOWS ACROSS MOST OF THE AREA WERE IN THE SINGLE
DIGITS THIS MORNING...AFTER SEVERAL SUCCESSIVE DAYS OF ARCTIC
COLD. WHILE HIGHS WILL MODERATE SUBSTANTIALLY TODAY...HIGH CLOUDS
ARE FAIRLY COMMON THIS MORNING...AND A MID-CLOUD DECK IS RUNNING
QUICK ON THE HEELS OF THE MORNING HIGH CLOUDS FOR THIS AFTERNOON.
THIS WILL LIKELY LIMIT THE UPWARD MOBILITY OF TEMPERATURES THIS
AFTERNOON...EVEN WITH A DRY COLUMN...SOME MODEST MIXING...WARM
ADVECTION...AND SUBSTANTIALLY WARMER AIR COMING OVER THE REGION
OFF THE DECK. THAT SAID...IT SEEMS AT THE VERY LEAST THAT
EVERYWHERE SOUTH OF PITTSBURGH SHOULD ECLIPSE FREEZING
TODAY...WITH SOME AREAS TOWARD MORGANTOWN AND SUCH LIKELY RUNNING
ABOVE 40F THIS AFTERNOON. HOWEVER...WITH VERY COLD GROUND AND SNOW
COVER...THIS WARMER AIR WILL LIKELY DO LITTLE BEYOND WORK ON
MELTING SOME OF THE SNOW COVER...AND WITH LIMITED SUN...LIKELY
HAVE LITTLE EFFECT UPON THE GROUND ITSELF.
WITH FAIRLY DEEP ISENTROPIC LIFT MOVING INTO THE AREA AFTER 00Z
TONIGHT...THIS WILL ALSO ALLOW TIME FOR THE BOUNDARY LAYER TO
DECOUPLE AND LIKELY COOL A FEW DEGREES FROM THE DAYTIME HIGHS
PRIOR TO PRECIPITATION ONSET. THAT COMBINED WITH MODEST WARM
ADVECTION AND A STILL RATHER DRY COLUMN MAKES A CONTINUATION OF
WARMER BOUNDARY LAYER AIR PROBLEMATIC GOING INTO THE OVERNIGHT
ACROSS THE VAST MAJORITY OF THE AREA. IT WOULD SEEM WARM ADVECTION
SHOULD BE OVERCOME BY WET BULB COOLING...AND NAM AND GFS 925 MB
TEMPERATURES GENERALLY REVEAL THIS TREND FAIRLY WELL LATE THIS
EVENING. HOWEVER...THE NAM ALLOWS FOR SURFACE WARM ADVECTION TO
TAKE OVER AND WARM MUCH OF THE FORECAST AREA SOUTH OF A GENERAL
NEW CASTLE TO DUBOIS LINE ABOVE FREEZING IN THE LOW LEVELS SUCH
THAT IT SUGGESTS PLAIN RAIN WOULD BE LIKELY TO BE FALLING ACROSS
ALL OF THESE AREAS BY MONDAY MORNING. WHILE THIS IS CERTAINLY
METEOROLOGICALLY PLAUSIBLE...ANTECEDENT COLD AND ABUNDANT FROST
IN THE GROUND WILL ALMOST UNDOUBTEDLY CAUSE THE GROUND TO FREEZING
BACK UP OVERNIGHT TONIGHT. THAT SAID...WHETHER AIR TEMPERATURES
ARE BELOW FREEZING OR NOT MAY NOT BE PARTICULARLY MEANINGFUL TO
WHETHER RAIN IS FREEZING ON CONTACT WITH THE SURFACE OVER MUCH OF
THE AREA. AS SUCH...FOR AREAS WHERE MODEL SOUNDINGS SUGGEST RAIN
OR FREEZING RAIN...A FREEZING RAIN ADVISORY HAS BEEN HOISTED FOR
TONIGHT THROUGH MONDAY MORNING.
A BIT FURTHER NORTH AND GENERALLY IN CENTRAL OHIO TOWARD AREAS
JUST SOUTH OF I-80 IN PENNSYLVANIA...MODEL SOUNDINGS REALLY WAFFLE
QUITE A BIT IN HOW THEY HANDLE THE ELEVATED MELTING LAYER AND
WHETHER P-TYPES WILL REMAIN SNOW...SLEET...OR TREND TOWARD
FREEZING RAIN FOR A TIME. IN THIS CORRIDOR GENERALLY NORTH OF THE
PITTSBURGH AREA...INCLUDING ZANESVILLE...BUTLER...AND
PUNXSUTAWNEY...A WIDE RANGE OF WINTRY WEATHER IS EXPECTED. HOWEVER
HERE...AIR TEMPERATURES ARE GENERALLY LIKELY TO STAY BELOW
FREEZING THROUGHOUT THE EVENT. AS SUCH...SNOW AND ICE
ACCUMULATIONS ARE MUCH MORE LIKELY IN THIS CORRIDOR...WITH
PROBLEMS FROM BOTH LIKELY TO BE MORE LONG LASTING AS WELL.
AGAIN FARTHER NORTH...AND GENERALLY NORTH OF I-80...THE MAJORITY
OF THE MODEL GUIDANCE POINTS TOWARD A NEARLY ALL SNOW EVENT. THIS
JIVES WELL WITH THERMAL PROFILE EXPECTATIONS AND GIVEN THE LARGE
SCALE LIFTING PROFILE AND THE FACT THAT IT BISECTS THE DENDRITIC
GROWTH LAYER...PARTICULARLY ON MONDAY MORNING...A MODERATE
ACCUMULATING SNOW SEEMS LIKELY. WINTER WEATHER ADVISORIES HAVE
BEEN ISSUED HERE FOR SNOW FOR THE EVENT...THOUGH A PERIOD OF
MIXING WITH SLEET MAY BE POSSIBLE AS WELL.
WHILE THERE IS STILL A FAIR AMOUNT OF MODEL SPREAD FOR THIS
EVENT...THE FACT THAT COLD AIR HAS BEEN ENTRENCHED FOR SO LONG AND
WE HAVE SNOW COVER ALLOWS ENOUGH CONFIDENCE FOR HEADLINES TO BE
ISSUED. HOWEVER...IF THE COLDER GFS SOLUTION VERIFIES...SNOW
ACCUMULATIONS WILL LIKELY REPLACE THE ICE ACCUMULATIONS IN THE
FORECAST FOR SOME AREAS SOUTH OF I-80. THOSE AREAS IN PARTICULAR
SHOULD STAY ABREAST OF THE LATEST FORECAST UPDATES AS THE SYSTEM
UNFOLDS. ADDITIONALLY...TO THE SOUTHEAST IN THE CWA...A LATE ONSET
OF PRECIPITATION COMBINED WITH 850 MB TEMPERATURES CLIMBING AS
HIGH AS +5C WITH STRONGER WARM ADVECTION THROUGH THE EVENT REALLY
MAKE FORECASTING ICE PROBLEMATIC. DUE TO A LATER ONSET...HEADLINES
WERE NOT ISSUED FOR THIS AREA IN ORDER TO ALLOW FUTURE SHIFTS TO
FURTHER ANALYZE THE EVOLUTION OF THE SYSTEM AS IT NEARS.
HOWEVER...A PERIOD OF ICING EVEN HERE MAY BE POSSIBLE DEPENDING
UPON HOW WARM IT DOES GET THIS AFTERNOON AND WHETHER WARM
ADVECTION CAN BE OVERCOME BY WET BULB COOLING OVERNIGHT.
ALL AREAS SHOULD TRANSITION BACK TOWARD COLDER WEATHER BY MONDAY
AFTERNOON AS A COLD FRONT SLICES THROUGH THE AREA. THIS SHOULD END
THE THREAT OF ANY ADDITIONAL ICING ACROSS THE CWA. FRIES
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BEGINNING TO SINK IN FROM THE NORTH MON NIGHT WILL
QUICKLY LOWER INVERSION HEIGHTS AND DRY OUT THE COLUMN...SHUTTING
DOWN PRECIPITATION CHANCES NORTH TO SOUTH THROUGH TUES MORNING. COLD
AND DRY NRLY FLOW WILL BRING 850MB TEMPS NEAR -10C ACROSS THE NORTH
TUES MORNING...WHILE THE SLIGHTLY WARMER AND MORE MOIST AIRMASS GETS
HUNG NEAR OUR SE RIDGES IN THE ZONAL FLOW ALOFT. THIS WILL SET UP A
FAIRLY STRONG GRADIENT OF CLOUDS AND TEMPERATURES NORTH TO SOUTH
ACROSS OUR CWA TUES AND EARLY WEDS. TUES MORNING TEMPS WILL RANGE
FROM THE LOW SINGLE DIGITS NORTH OF I-80 TO IN THE LOW 20S IN OUR
SRNMOST ZONES. WITH HIGH PRESSURE SETTLING IN ACROSS THOSE COLD NRN
AREAS...SFC FLOW IS EXPECTED TO BE FAIRLY LIGHT BUT WIND CHILL
VALUES DO APPROACH ADVISORY CRITERIA. THIS WILL NEED TO BE MONITORED
IN FURTHER UPDATES.
SRN MOISTURE IS RELUCTANT TO FULLY CLEAR THE SE RIDGES TUES NIGHT
AND ANOTHER WEAK UPPER LEVEL WAVE PUSHES THAT MOISTURE FURTHER NORTH
MIDDAY WEDS. ALTHOUGH MODEL SOLNS DIVERGE ON JUST HOW FAR THAT
MOISTURE RETURNS...WILL KEEP SLIGHT CHC SNOW IN FOR THE HIGHEST
ELEVATIONS. THE UPPER LEVEL WAVE EJECTS REMAINING MOISTURE WEDS
AFTERNOON...AND WITH HIGH PRESSURE FIRMLY IN CONTROL...A DRY MIDWEEK
CAN BE EXPECTED.
TAX
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
CONSIDERABLE MODEL AGREEMENT EXISTS IN THE EXTENDED AS THE
RELATIVELY DRY TREND IS EXPECTED TO CONTINUE INTO DAY 7 WITH NO
MAJOR SYSTEMS FORECAST. SFC HIGH PRESSURE WILL HOLD IN THE AREA THROUGH
THURS...KEEPING TWO WEAK SYSTEMS OUT OF THE FORECAST AREA WITH ONE
STREAMING WELL NORTH AND ANOTHER WELL TO OUR SOUTH. AN INCREASE IN
CLOUDS AND MAYBE A FEW LIGHT SNOW SHOWERS COULD DEVELOP ON THE SRN
TAIL OF THE NRN TRACK SYSTEM...BUT LITTLE ELSE IS EXPECTED.
TEMPERATURES WILL MODERATE CLOSER TO NORMALS THURS AND FRIDAY. SFC
HIGH WILL BUILD BACK IN TOWARDS THE END OF THE WORK WEEK. AS THE
AXIS OF THE HIGH SHIFTS EAST OF THE AREA NEXT WEEKEND SRLY FLOW WILL
BRING TEMPERATURES ABOVE AVERAGE.
TAX
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
GENERALLY CALM WINDS WITH A FEW HIGH CLOUDS OVERNIGHT WILL GIVE
WAY TO INCREASING SOUTHWESTERLY FLOW ON SUNDAY WITH BROKEN HIGH
CLOUDS CONTINUING. THE NEXT SYSTEM WILL APPROACH FROM THE
SOUTHWEST SUNDAY EVENING AND SPREAD A WINTRY MIX OF PRECIPITATION
OVER ALL THE SITES. PRECIPITATION TYPES SEEM LIKELY TO RANGE THE
FULL GAMUT...WITH SPECIFICS STILL LOW CONFIDENCE AS MODEL
SOLUTIONS VARY WILDLY. HOWEVER...DUE TO RECENT VERY COLD WEATHER
AND WARM ADVECTION ALOFT...IT WOULD SEEM AT LEAST SOME ICING IS
POSSIBLE OVERNIGHT AT MOST TERMINALS SAVE FOR THE FAR
NORTH...WHERE COLD AIR SHOULD REMAIN DEEP ENOUGH FOR ALL SNOW TO
FALL. FRIES
OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
VFR CONDITIONS RETURN WITH HIGH PRESSURE MIDWEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR OHZ039>041-048-057.
FREEZING RAIN ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR OHZ049-050-058-059-068-069.
PA...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR PAZ013>016-020-022.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
MONDAY FOR PAZ007>009.
FREEZING RAIN ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR PAZ021-023-029-031-073>076.
WV...FREEZING RAIN ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR WVZ001>004-012.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
123 PM EST SUN JAN 11 2015
.UPDATE...
ISSUED AT 109 PM EST SUN JAN 11 2015
LAKE EFFECT SNOW ADVISORY HAS BEEN ONCE AGAIN BEEN POSTED FOR THE
KEWEENAW PENINSULA /N HOUGHTON AND KEWEENAW COUNTY/ UNTIL 06Z
TONIGHT. THE 1-2IN/HR SNOWFALL RATES SHOULD BE DIMINISHING LATER
THIS AFTERNOON AND THE MAIN BANDS WILL SHIFT FARTHER S AS MORE NW
FLOW PUSHES IN. THE RE-INTRODUCTION OF COLDER AIR ALOFT SHOULD
BRING THE DGZ DOWN NEAR OR BELOW THE SFC. THE LARGE FLAKES WITH
RATIOS OF 25:1 WILL BE COME TO AN END...RETURNING TO NEAR 20:1.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST SUN JAN 11 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF PERSISTING
OVER ERN NAMERICA. HOWEVER...HEIGHTS HAVE BEEN RISING SIGNIFICANTLY
OVER THE ERN CONUS (00Z RAOBS SHOW 12HR 500MB HEIGHT RISES OF
100-200M FROM THE UPPER MISSISSIPPI VALLEY TO THE E COAST)...
INDICATING A RELAXATION OF THE RECENT VERY COLD PATTERN. UPSTREAM...
A SHORTWAVE TROF IS DROPPING S INTO SASKATCHEWAN/MANITOBA. THIS WILL
BE THE MAIN FEATURE OF INTEREST IN THE SHORT TERM AS IT SWINGS SE
INTO THE UPPER GREAT LAKES LATE TONIGHT/MON MORNING. 850MB TEMPS ARE
CURRENTLY AROUND -18C PER LATEST RUC ANALYSIS...AND THIS IS
CONTINUING TO SUPPORT LES OVER LAKE SUPERIOR. A SFC TROF...ENHANCED
BY THE RELATIVELY WARM WATERS...EXTENDS ACROSS LAKE SUPERIOR EARLY
THIS MORNING. OVER WRN LAKE SUPERIOR...LAND BREEZE ENHANCED FLOW
AHEAD OF TROF IS FOCUSING LES MOSTLY OFFSHORE OF WRN UPPER MI...
EXCEPT OVER THE KEWEENAW. TO THE E...LES IS WELL OFFSHORE WITH HINTS
OF A CONVERGENT DOMINANT BAND ALONG TROF TO THE E OF STANNARD ROCK.
MODELS SHOW THE SFC TROF CURRENTLY OVER LAKE SUPERIOR WEAKENING AND
DRIFTING SE TODAY. OVER WRN LAKE SUPERIOR...NOT MUCH CHANGE IN WIND
DIRECTION IS INDICATED AS THIS OCCURS. OVER ERN LAKE SUPERIOR...LES
WILL DRIFT SLOWLY S AS WINDS BECOME MORE WNW. AS A RESULT...SCT TO
NMRS -SHSN WILL LINGER OVER NW UPPER MI TODAY...MAINLY THE
KEWEENAW...WHILE TO THE E...-SHSN SHOULD SETTLE/DEVELOP SE AND AT
LEAST BRUSH THE SHORE E OF MUNISING. -SHSN WON`T PUSH TOO FAR INLAND
SINCE THERE IS LITTLE N COMPONENT TO THE WIND. WITH INVERSION AT
3-4KFT...LES WILL BE ON THE LIGHT SIDE. DGZ DOES DOMINATE THE
CONVECTIVE LAYER THOUGH...AND THIS WILL LEAD TO HIGHER SNOW TO WATER
RATIOS. MIGHT SEE A COUPLE OF INCHES WHERE LES IS MOST PERSISTENT
TODAY. MEANWHILE...AHEAD OF THE APPROACHING SHORTWAVE TROF...MODELS
SHOW STRENGTHENING OF A JET STREAK FROM NRN MN TO NEW ENGLAND/SRN
QUEBEC TODAY. RIGHT ENTRANCE OF THIS JET MAY PROVIDE SUFFICIENT
FORCING FOR A STREAK OF -SN/FLURRIES TO DEVELOP AND SPREAD FROM MN
TO NRN WI/SRN UPPER MI LATE THIS AFTN/EVENING. OVER THE LAST DAY OR
SO...ALL MODEL GUIDANCE HAS TRENDED TOWARD SHOWING THIS STREAK OF
-SN. LOW-LEVEL DRY AIR WILL BE A HINDRANCE...BUT GIVEN MODEL
TRENDS...AT LEAST SCHC POPS ARE WARRANTED LATE AFTN/EVENING ACROSS
THE SRN FCST AREA.
TONIGHT...SHORTWAVE WILL SWING SE...PASSING ACROSS THE UPPER LAKES
LATE TONIGHT/MON MORNING. SINCE BULK OF THE DEEP LAYER FORCING
PASSES TO THE NE AND THERE IS AN ABSENCE OF ANY MOISTURE INFLOW IN
ADVANCE OF THIS DISTURBANCE...ACCOMPANYING PCPN SHOULD BE LIMITED TO
AREAS NEAR LAKE SUPERIOR. VEERING FLOW TO THE NW AND 850MB TEMPS
FALLING BACK TO -20 TO -24C BY 12Z MON IN THE WAKE OF ATTENDANT COLD
FROPA WILL BRING AN INCREASE IN LES TONIGHT INTO MON MORNING.
GFS/NAM FCST SOUNDINGS SHOW LIMITED IMPACT ON INVERSION...ONLY
RISING TO NEAR 5KFT...WHICH IS A LITTLE SURPRISING SINCE THE DEEP
LAYER FORCING PER QVECTORS IS NOT THAT WEAK. FORCING AND DEGREE OF
OVERWATER INSTABILITY WARRANTS CATEGORICAL POPS FOR AREAS FAVORED BY
NW WINDS TONIGHT. FOR NOW...EXPECT 1-3 INCHES OF SNOW BY DAYBREAK
MON. THE LONGER FETCH INTO NCNTRL UPPER MI AND DEEPER DGZ THERE
SUGGEST GREATER COVERAGE OF 2-3 INCH AMOUNTS WILL BE FROM MUNISING
EASTWARD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 438 AM EST SUN JAN 11 2015
DECENT AGREEMENT THAT LARGE TROUGH OVER EASTERN CANADA GRADUALLY
LOSES ITS INFLUENCE OVER THE GREAT LAKES BY NEXT WEEKEND. A COUPLE OF
LAST PUSHES OF ARCTIC AIR WILL GIVE UPPER GREAT LAKES GLANCING BLOWS
OF COLDER TEMPS...FIRST ON MONDAY...THEN AGAIN ON THURSDAY. BY NEXT
WEEKEND ZONAL FLOW IS IN FULL SWING AS STRONG JET STREAK PLOWING
ACROSS THE PACIFIC MASHES HEIGHTS DOWN OVER THE WESTERN CONUS. H85
TEMPS AS LOW AS -24C ON MONDAY MORNING WILL BE REPLACED WITH VALUES
RISING ABOVE ZERO ON FRIDAY. EXPECT TEMPS TO BE WELL INTO THE 20S AT
THE SFC BY THE TIME WE REACH LATE THIS WEEK.
INITIAL BATCH OF COLD AIR TIED TO SHORTWAVE DROPPING OVER THE AREA
TONIGHT RESULTS IN LAKE EFFECT SNOW SHOWERS KICKING UP IN NNW-N FLOW
INTO MONDAY MORNING. LIMITED DIRECT IMPACT FM THE SHORTWAVE TO
ENHANCE THE LES. INVERSIONS UP TO 5KFT AND GENERAL UNIDIRECTIONAL
FLOW WITHIN THE CLOUD LAYER WILL AID IN ORGANIZATION. SINCE MUCH OF
CLOUD LAYER IS WITHIN THE DGZ COULD SEE FEW INCHES OF FLUFFY
ACCUMULATION. A NEGATIVE FACTOR WILL BE BLYR WINDS STEADILY VEERING
FM NW TO NNE LATE TONIGHT INTO MONDAY MORNING WHICH WILL NOT ALLOW
THE BANDS TO AFFECT ANY ONE LOCATION FOR TOO LONG OF A DURATION.
TIMING WILL MATTER AS IF THE STRONGER LES DROPS ALONG LK SUPERIOR
EARLIER ON MONDAY...THEN THE MORNING COMMUTE WOULD BE IMPACTED. MAY
MENTION IN HWO...BUT OVERALL SEEMS LIKE MAY BE ABLE TO GET BY WITHOUT
HAVING A HEADLINE FOR THE LES. INVERSIONS LOWER FURTHER BY MONDAY
AFTN BELOW 5KFT AND LOW-LEVEL CONVERGENCE WEAKENS AS LARGE HIGH
PRESSURE RIDGE OVER 1040MB BUILDS FM THE NORTHERN PLAINS TOWARD THE
WESTERN GREAT LAKES...SO LES WILL CONTINUE TO TREND DOWNWARD IN
INTENSITY.
BY MONDAY NIGHT WHATEVER IS LEFT OF THE LES SHOULD BE SPUTTERING
ALONG AS MAINLY FLURRIES FOR THE SNOW BELTS EAST OF MARQUETTE AS
WINDS BACK NW. RIDGE/DRY AIR AND CONTINUAL BACKING WINDS WILL END
LES OVERNIGHT. CALM BUT COLD CONDITIONS INLAND WITH THE RIDGING
OVERHEAD. A BIT MORE OF A GRADIENT WSW WIND KEEPS TEMPS NOT AS COLD
OVER THE KEWEENAW AND NEAR LK SUPERIOR. INLAND THOUGH...PWATS LESS
THAN 0.10 INCH AND CALM CONDITIONS WILL RESULT IN PRIME RADIATIONAL
COOLING WITH TYPICAL COLD SPOTS POSSIBLY DROPPING TO READINGS LOWER
THAN 20 BLO. THANKFULLY NO WIND CHILL ISSUES AS IT SHOULD BE CALM
WHERE TEMPS ARE THAT LOW.
RIDGE STILL ENOUGH IN VCNTY TUESDAY TO LIMIT MIXING DEPTH AND THUS
KEEP MAX TEMPS IN THE LOW-MID TEENS. EXCEPTION WILL BE ALONG LK
SUPERIOR WEST THROUGH NCNTRL WHERE WSW FLOW PROVIDES SOME DOWNSLOPE
WARMING AND COULD BOOST TEMPS ABOVE 20 DEGREES. A RELATIVE HEAT
WAVE COMPARED TO THE CHILL THAT HAS BEEN AROUND THE LAST WEEK OR SO.
WSW WINDS MAY GET GUSTY OVER LK SUPERIOR AND KEWEENAW ON TUESDAY
NIGHT. MAY SEE WINDS OVER 30 MPH FOR PARTS OF THE KEWEENAW. WINDS MAY
STAY STRONG ENOUGH TO RESULT IN TEMPS NEAR LK SUPERIOR STAYING STEADY
OR ONLY SLIGHTLY FALLING. INLAND OVER WEST HALF...BLENDED BACK TOWARD
GOING FORECAST WITH MINS SLIPPING BLO ZERO AS IT WOULD NOT TAKE MUCH
DECOUPLING TO HAVE TEMPS FALL OFF IN INTERIOR SHELTERED AREAS. COULD
SEE DECENT RANGE IN MIN TEMPS OVR THE CWA THIS NIGHT.
WEAK LOW PRESSURE TROUGH...EXTENSION FM STRONGER LOW PRESSURE TIED
TO SHORTWAVE OVER NORTHERN ONTARIO...CROSSES LK SUPERIOR ON
WEDNESDAY. GIVEN WEST-SOUTHWEST WINDS...BEST CHANCE OF ANY LGT SNOW
WOULD BE ON THE KEWEENAW. ONCE THE TROUGH SLIDES FARTHER OVER THE
AREA ON WEDNESDAY NIGHT INTO THURSDAY...SHOWED CHANCES ALONG MUCH OF
THE NORTHERN CWA. MARGINAL FM A STRICT LES STANDPOINT WITH H85 TEMPS
ONLY AROUND -12C...BUT BOTH GFS AND ECMWF HINT AT ADDITIONAL FORCING
AND MOISTENING...SO COULD BE LAKE ENHANCED SNOW FOR AT LEAST A BRIEF
PERIOD. TROUGH THEN BOUNCES EAST ON FRIDAY AND MAY EVEN TAKE SHAPE
AS A WARM FRONT...AT LEAST ALOFT. DOES SEEM THAT GFS AND ECMWF HINT
THAT THERE WOULD BE SW-W WINDS FOR FRIDAY WITH H85 TEMPS WARMING
ABOVE 0C. GFS SOUNDINGS INDICATE SHALLOW MIXING HEIGHT WITH MOST OF
THE WARMING STAYING ALOFT. INCREASED TEMPS A BIT OVER CONSENSUS WITH
THE HINTS SHOWING UP AND HAVE MID 20S INLAND AND A SHOT AT CRACKING
30 DEGREES ALONG LK SUPERIOR WITH THE SW WINDS. RAN TEMPS UP TO 30
DEGREES FOR NOW...BUT BIAS CORRECTED ECMWF GUIDANCE DID HAVE EVEN
MID 30S. LIKELY WOULD NEED TO HAVE DECENT SUNSHINE/MIXING FOR THAT
TO HAPPEN...BUT FOR NOW INCHED HIGH TEMPS UP SOME. LAST TIME NWS
OFFICE IN NEGAUNEE TOWNSHIP SAW A HIGH TEMP OF 30 DEGREES WAS JUST
AFTER CHRISTMAS ON THE MORNING OF 27 DEC. TEMPS WENT IN A FREE FALL
AFTER THAT THOUGH AND HAVE ONLY BEEN ABOVE 20 DEGREES DURING THE
DAYTIME HOURS ON ONE DAY...3 JAN. A FEW DAYS WITH HIGHS IN THE 20S
WOULD BE QUITE WELCOME.
NO ADJUSTMENTS TO CONSENSUS FORECAST FOR NEXT WEEKEND AS ECMWF IS
TRYING TO SHOW A STRONGER/DIGGIER SHORTWAVE AND STRONGER COLD FRONT
PASSAGE...WHILE THE GFS TURNS MORE PROGRESSIVE AND KEEPS TROUGH TO
THE NORTH SO THUS ANOTHER WARMER DAY. GEM-NH ON ITS LAST PANEL AT 00Z
SAT 17 JAN LOOKS MORE LIKE THE GFS. USED A BLEND FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 123 PM EST SUN JAN 11 2015
DESPITE LIGHTER WINDS THAN LATE...THE LARGE MORE PRISTINE SNOWFLAKES
HAVE STILL BEEN QUITE PRODUCTIVE AT REDUCING VIS AT CMX. HAVE HAD
REPORTS OF 1-2IN/HR SNOWFALL IN THE DOMINANT BAND OF LAKE EFFECT
SNOW SET UP TO THE W AND NW OF CMX. THIS BAND WILL LIKELY SHIFT
ACROSS CMX LATER THIS AFTERNOON...WITH VIS LINGERING AROUND 1SM INTO
THE EVENING HOURS. LATER TONIGHT NW WINDS WILL SLOWLY PUSH IN BEHIND
A COLD FRONT DROPPING THROUGH THE AREA. THE BEST CHANCE OF SNOW WILL
THEN SHIFT FARTHER S OF CMX AFTER 04-06Z...WITH CEILINGS GOING BACK
TO MVFR TO HIGH END IFR.
IWD WILL STAY VFR UNTIL MORE WNW-N FLOW PUSHES LAKE EFFECT SNOW
SHOWERS INTO THE AREA AROUND/AFTER 08Z MONDAY. LOOK FOR NEAR IFR
CEILING/VIS TO LINGER THROUGH 18Z MONDAY.
AT SAW...THE N FLOW BRING -SHSN BY 06Z...WITH IFR CONDITIONS
EXPECTED TO BEGIN BETWEEN 12-16Z MONDAY AS BETTER CONVERGENCE SETS
UP ON MAINLY N FLOW OFF LAKE SUPERIOR BEHIND THE PASSING COLD FRONT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EST SUN JAN 11 2015
WINDS HAVE DIMINISHED BLO 25 KTS AND WILL STAY THAT WAY THROUGH MOST
OF TONIGHT EVEN AS LOW PRESSURE TROUGH WORKS ACROSS THE LAKE. STRONGER
COLD FRONT SWEEPS OVER LK SUPERIOR LATE TONIGHT AND EXPECT WINDS TO
SHIFT TO THE NORTH AND PEAK AROUND 30 KTS AROUND SUNRISE ON MONDAY...BEFORE
QUICKLY DIMINISHING TO LESS THAN 20 KTS ON MONDAY AFTN. HEAVY FREEZING
SPRAY WILL RETURN LATE TONIGHT BUT UNLIKE LAST WEEK...IT WILL NOT
LAST LONG...ENDING BY MONDAY EVENING AS HIGH PRESSURE DRIFTS ACROSS.
WINDS WILL INCREASE AGAIN LATE MONDAY NIGHT INTO TUESDAY OUT OF THE
SOUTHWEST. STRONGEST WINDS TO 30 KTS EXPECTED OVER WESTERN AND NORTH
CENTRAL LK SUPERIOR. COULD SEE GALE GUSTS TUESDAY AFTN INTO TUESDAY
EVENING BTWN TIP OF KEWEENAW AND ISLE ROYALE. HEAVY FREEZING SPRAY IS
NOT EXPECTED AS WILL BE HIGHER THAN SEEN RECENTLY. WINDS DIMINISH TO
25 KTS OR LESS BY WEDNESDAY AND SHOULD REMAIN AT SIMILAR SPEEDS
THROUGH LATE THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST MONDAY FOR MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 4 PM EST MONDAY FOR
LSZ248>251-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM TO 1 PM EST MONDAY FOR
LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 1 PM EST MONDAY FOR
LSZ242-263.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KF
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...KF
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
111 PM EST SUN JAN 11 2015
.UPDATE...
ISSUED AT 109 PM EST SUN JAN 11 2015
LAKE EFFECT SNOW ADVISORY HAS BEEN ONCE AGAIN BEEN POSTED FOR THE
KEWEENAW PENINSULA /N HOUGHTON AND KEWEENAW COUNTY/ UNTIL 06Z
TONIGHT. THE 1-2IN/HR SNOWFALL RATES SHOULD BE DIMINISHING LATER
THIS AFTERNOON AND THE MAIN BANDS WILL SHIFT FARTHER S AS MORE NW
FLOW PUSHES IN. THE RE-INTRODUCTION OF COLDER AIR ALOFT SHOULD
BRING THE DGZ DOWN NEAR OR BELOW THE SFC. THE LARGE FLAKES WITH
RATIOS OF 25:1 WILL BE COME TO AN END...RETURNING TO NEAR 20:1.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST SUN JAN 11 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF PERSISTING
OVER ERN NAMERICA. HOWEVER...HEIGHTS HAVE BEEN RISING SIGNIFICANTLY
OVER THE ERN CONUS (00Z RAOBS SHOW 12HR 500MB HEIGHT RISES OF
100-200M FROM THE UPPER MISSISSIPPI VALLEY TO THE E COAST)...
INDICATING A RELAXATION OF THE RECENT VERY COLD PATTERN. UPSTREAM...
A SHORTWAVE TROF IS DROPPING S INTO SASKATCHEWAN/MANITOBA. THIS WILL
BE THE MAIN FEATURE OF INTEREST IN THE SHORT TERM AS IT SWINGS SE
INTO THE UPPER GREAT LAKES LATE TONIGHT/MON MORNING. 850MB TEMPS ARE
CURRENTLY AROUND -18C PER LATEST RUC ANALYSIS...AND THIS IS
CONTINUING TO SUPPORT LES OVER LAKE SUPERIOR. A SFC TROF...ENHANCED
BY THE RELATIVELY WARM WATERS...EXTENDS ACROSS LAKE SUPERIOR EARLY
THIS MORNING. OVER WRN LAKE SUPERIOR...LAND BREEZE ENHANCED FLOW
AHEAD OF TROF IS FOCUSING LES MOSTLY OFFSHORE OF WRN UPPER MI...
EXCEPT OVER THE KEWEENAW. TO THE E...LES IS WELL OFFSHORE WITH HINTS
OF A CONVERGENT DOMINANT BAND ALONG TROF TO THE E OF STANNARD ROCK.
MODELS SHOW THE SFC TROF CURRENTLY OVER LAKE SUPERIOR WEAKENING AND
DRIFTING SE TODAY. OVER WRN LAKE SUPERIOR...NOT MUCH CHANGE IN WIND
DIRECTION IS INDICATED AS THIS OCCURS. OVER ERN LAKE SUPERIOR...LES
WILL DRIFT SLOWLY S AS WINDS BECOME MORE WNW. AS A RESULT...SCT TO
NMRS -SHSN WILL LINGER OVER NW UPPER MI TODAY...MAINLY THE
KEWEENAW...WHILE TO THE E...-SHSN SHOULD SETTLE/DEVELOP SE AND AT
LEAST BRUSH THE SHORE E OF MUNISING. -SHSN WON`T PUSH TOO FAR INLAND
SINCE THERE IS LITTLE N COMPONENT TO THE WIND. WITH INVERSION AT
3-4KFT...LES WILL BE ON THE LIGHT SIDE. DGZ DOES DOMINATE THE
CONVECTIVE LAYER THOUGH...AND THIS WILL LEAD TO HIGHER SNOW TO WATER
RATIOS. MIGHT SEE A COUPLE OF INCHES WHERE LES IS MOST PERSISTENT
TODAY. MEANWHILE...AHEAD OF THE APPROACHING SHORTWAVE TROF...MODELS
SHOW STRENGTHENING OF A JET STREAK FROM NRN MN TO NEW ENGLAND/SRN
QUEBEC TODAY. RIGHT ENTRANCE OF THIS JET MAY PROVIDE SUFFICIENT
FORCING FOR A STREAK OF -SN/FLURRIES TO DEVELOP AND SPREAD FROM MN
TO NRN WI/SRN UPPER MI LATE THIS AFTN/EVENING. OVER THE LAST DAY OR
SO...ALL MODEL GUIDANCE HAS TRENDED TOWARD SHOWING THIS STREAK OF
-SN. LOW-LEVEL DRY AIR WILL BE A HINDRANCE...BUT GIVEN MODEL
TRENDS...AT LEAST SCHC POPS ARE WARRANTED LATE AFTN/EVENING ACROSS
THE SRN FCST AREA.
TONIGHT...SHORTWAVE WILL SWING SE...PASSING ACROSS THE UPPER LAKES
LATE TONIGHT/MON MORNING. SINCE BULK OF THE DEEP LAYER FORCING
PASSES TO THE NE AND THERE IS AN ABSENCE OF ANY MOISTURE INFLOW IN
ADVANCE OF THIS DISTURBANCE...ACCOMPANYING PCPN SHOULD BE LIMITED TO
AREAS NEAR LAKE SUPERIOR. VEERING FLOW TO THE NW AND 850MB TEMPS
FALLING BACK TO -20 TO -24C BY 12Z MON IN THE WAKE OF ATTENDANT COLD
FROPA WILL BRING AN INCREASE IN LES TONIGHT INTO MON MORNING.
GFS/NAM FCST SOUNDINGS SHOW LIMITED IMPACT ON INVERSION...ONLY
RISING TO NEAR 5KFT...WHICH IS A LITTLE SURPRISING SINCE THE DEEP
LAYER FORCING PER QVECTORS IS NOT THAT WEAK. FORCING AND DEGREE OF
OVERWATER INSTABILITY WARRANTS CATEGORICAL POPS FOR AREAS FAVORED BY
NW WINDS TONIGHT. FOR NOW...EXPECT 1-3 INCHES OF SNOW BY DAYBREAK
MON. THE LONGER FETCH INTO NCNTRL UPPER MI AND DEEPER DGZ THERE
SUGGEST GREATER COVERAGE OF 2-3 INCH AMOUNTS WILL BE FROM MUNISING
EASTWARD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 438 AM EST SUN JAN 11 2015
DECENT AGREEMENT THAT LARGE TROUGH OVER EASTERN CANADA GRADUALLY
LOSES ITS INFLUENCE OVER THE GREAT LAKES BY NEXT WEEKEND. A COUPLE OF
LAST PUSHES OF ARCTIC AIR WILL GIVE UPPER GREAT LAKES GLANCING BLOWS
OF COLDER TEMPS...FIRST ON MONDAY...THEN AGAIN ON THURSDAY. BY NEXT
WEEKEND ZONAL FLOW IS IN FULL SWING AS STRONG JET STREAK PLOWING
ACROSS THE PACIFIC MASHES HEIGHTS DOWN OVER THE WESTERN CONUS. H85
TEMPS AS LOW AS -24C ON MONDAY MORNING WILL BE REPLACED WITH VALUES
RISING ABOVE ZERO ON FRIDAY. EXPECT TEMPS TO BE WELL INTO THE 20S AT
THE SFC BY THE TIME WE REACH LATE THIS WEEK.
INITIAL BATCH OF COLD AIR TIED TO SHORTWAVE DROPPING OVER THE AREA
TONIGHT RESULTS IN LAKE EFFECT SNOW SHOWERS KICKING UP IN NNW-N FLOW
INTO MONDAY MORNING. LIMITED DIRECT IMPACT FM THE SHORTWAVE TO
ENHANCE THE LES. INVERSIONS UP TO 5KFT AND GENERAL UNIDIRECTIONAL
FLOW WITHIN THE CLOUD LAYER WILL AID IN ORGANIZATION. SINCE MUCH OF
CLOUD LAYER IS WITHIN THE DGZ COULD SEE FEW INCHES OF FLUFFY
ACCUMULATION. A NEGATIVE FACTOR WILL BE BLYR WINDS STEADILY VEERING
FM NW TO NNE LATE TONIGHT INTO MONDAY MORNING WHICH WILL NOT ALLOW
THE BANDS TO AFFECT ANY ONE LOCATION FOR TOO LONG OF A DURATION.
TIMING WILL MATTER AS IF THE STRONGER LES DROPS ALONG LK SUPERIOR
EARLIER ON MONDAY...THEN THE MORNING COMMUTE WOULD BE IMPACTED. MAY
MENTION IN HWO...BUT OVERALL SEEMS LIKE MAY BE ABLE TO GET BY WITHOUT
HAVING A HEADLINE FOR THE LES. INVERSIONS LOWER FURTHER BY MONDAY
AFTN BELOW 5KFT AND LOW-LEVEL CONVERGENCE WEAKENS AS LARGE HIGH
PRESSURE RIDGE OVER 1040MB BUILDS FM THE NORTHERN PLAINS TOWARD THE
WESTERN GREAT LAKES...SO LES WILL CONTINUE TO TREND DOWNWARD IN
INTENSITY.
BY MONDAY NIGHT WHATEVER IS LEFT OF THE LES SHOULD BE SPUTTERING
ALONG AS MAINLY FLURRIES FOR THE SNOW BELTS EAST OF MARQUETTE AS
WINDS BACK NW. RIDGE/DRY AIR AND CONTINUAL BACKING WINDS WILL END
LES OVERNIGHT. CALM BUT COLD CONDITIONS INLAND WITH THE RIDGING
OVERHEAD. A BIT MORE OF A GRADIENT WSW WIND KEEPS TEMPS NOT AS COLD
OVER THE KEWEENAW AND NEAR LK SUPERIOR. INLAND THOUGH...PWATS LESS
THAN 0.10 INCH AND CALM CONDITIONS WILL RESULT IN PRIME RADIATIONAL
COOLING WITH TYPICAL COLD SPOTS POSSIBLY DROPPING TO READINGS LOWER
THAN 20 BLO. THANKFULLY NO WIND CHILL ISSUES AS IT SHOULD BE CALM
WHERE TEMPS ARE THAT LOW.
RIDGE STILL ENOUGH IN VCNTY TUESDAY TO LIMIT MIXING DEPTH AND THUS
KEEP MAX TEMPS IN THE LOW-MID TEENS. EXCEPTION WILL BE ALONG LK
SUPERIOR WEST THROUGH NCNTRL WHERE WSW FLOW PROVIDES SOME DOWNSLOPE
WARMING AND COULD BOOST TEMPS ABOVE 20 DEGREES. A RELATIVE HEAT
WAVE COMPARED TO THE CHILL THAT HAS BEEN AROUND THE LAST WEEK OR SO.
WSW WINDS MAY GET GUSTY OVER LK SUPERIOR AND KEWEENAW ON TUESDAY
NIGHT. MAY SEE WINDS OVER 30 MPH FOR PARTS OF THE KEWEENAW. WINDS MAY
STAY STRONG ENOUGH TO RESULT IN TEMPS NEAR LK SUPERIOR STAYING STEADY
OR ONLY SLIGHTLY FALLING. INLAND OVER WEST HALF...BLENDED BACK TOWARD
GOING FORECAST WITH MINS SLIPPING BLO ZERO AS IT WOULD NOT TAKE MUCH
DECOUPLING TO HAVE TEMPS FALL OFF IN INTERIOR SHELTERED AREAS. COULD
SEE DECENT RANGE IN MIN TEMPS OVR THE CWA THIS NIGHT.
WEAK LOW PRESSURE TROUGH...EXTENSION FM STRONGER LOW PRESSURE TIED
TO SHORTWAVE OVER NORTHERN ONTARIO...CROSSES LK SUPERIOR ON
WEDNESDAY. GIVEN WEST-SOUTHWEST WINDS...BEST CHANCE OF ANY LGT SNOW
WOULD BE ON THE KEWEENAW. ONCE THE TROUGH SLIDES FARTHER OVER THE
AREA ON WEDNESDAY NIGHT INTO THURSDAY...SHOWED CHANCES ALONG MUCH OF
THE NORTHERN CWA. MARGINAL FM A STRICT LES STANDPOINT WITH H85 TEMPS
ONLY AROUND -12C...BUT BOTH GFS AND ECMWF HINT AT ADDITIONAL FORCING
AND MOISTENING...SO COULD BE LAKE ENHANCED SNOW FOR AT LEAST A BRIEF
PERIOD. TROUGH THEN BOUNCES EAST ON FRIDAY AND MAY EVEN TAKE SHAPE
AS A WARM FRONT...AT LEAST ALOFT. DOES SEEM THAT GFS AND ECMWF HINT
THAT THERE WOULD BE SW-W WINDS FOR FRIDAY WITH H85 TEMPS WARMING
ABOVE 0C. GFS SOUNDINGS INDICATE SHALLOW MIXING HEIGHT WITH MOST OF
THE WARMING STAYING ALOFT. INCREASED TEMPS A BIT OVER CONSENSUS WITH
THE HINTS SHOWING UP AND HAVE MID 20S INLAND AND A SHOT AT CRACKING
30 DEGREES ALONG LK SUPERIOR WITH THE SW WINDS. RAN TEMPS UP TO 30
DEGREES FOR NOW...BUT BIAS CORRECTED ECMWF GUIDANCE DID HAVE EVEN
MID 30S. LIKELY WOULD NEED TO HAVE DECENT SUNSHINE/MIXING FOR THAT
TO HAPPEN...BUT FOR NOW INCHED HIGH TEMPS UP SOME. LAST TIME NWS
OFFICE IN NEGAUNEE TOWNSHIP SAW A HIGH TEMP OF 30 DEGREES WAS JUST
AFTER CHRISTMAS ON THE MORNING OF 27 DEC. TEMPS WENT IN A FREE FALL
AFTER THAT THOUGH AND HAVE ONLY BEEN ABOVE 20 DEGREES DURING THE
DAYTIME HOURS ON ONE DAY...3 JAN. A FEW DAYS WITH HIGHS IN THE 20S
WOULD BE QUITE WELCOME.
NO ADJUSTMENTS TO CONSENSUS FORECAST FOR NEXT WEEKEND AS ECMWF IS
TRYING TO SHOW A STRONGER/DIGGIER SHORTWAVE AND STRONGER COLD FRONT
PASSAGE...WHILE THE GFS TURNS MORE PROGRESSIVE AND KEEPS TROUGH TO
THE NORTH SO THUS ANOTHER WARMER DAY. GEM-NH ON ITS LAST PANEL AT 00Z
SAT 17 JAN LOOKS MORE LIKE THE GFS. USED A BLEND FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 652 AM EST SUN JAN 11 2015
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO AFFECT KCMX TODAY UNDER
WNW WINDS. THERE IS SOME UNCERTAINTY IN VIS/CIG IMPACTS...BUT SINCE
CONDITIONS FAVOR MOSTLY LIGHT PCPN...EXPECT MVFR CONDITIONS TO
PREVAIL WITH SOME BRIEF PERIODS OF IFR. COLD FRONT PASSING THIS
EVENING WILL LIKELY BRING A PERIOD OF IFR CONDITIONS TO KCMX...AND
POTENTIALLY LIFR. AS WINDS SHIFT TOWARD A NORTHERLY DIRECTION
OVERNIGHT WHICH IS TYPICALLY LESS FAVORABLE FOR POOR
CONDITIONS/PERSISTENT HEAVIER SNOW SHOWERS AT KCMX...EXPECT MVFR
CONDITIONS TO RETURN. AT KIWD/KSAW...VFR CONDITIONS WILL PREVAIL
INTO THE EVENING HRS AS LOW-LEVEL AIR MASS REMAINS RELATIVELY DRY.
AS WINDS SHIFT NW TONIGHT IN ASSOCIATION WITH COLD FROPA...LAKE
EFFECT SNOW SHOWERS WILL INCREASE AT KIWD...DROPPING CONDITIONS TO
IFR LATE. AT KSAW...EXPECT MVFR CONDITIONS TO DEVELOP OVERNIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EST SUN JAN 11 2015
WINDS HAVE DIMINISHED BLO 25 KTS AND WILL STAY THAT WAY THROUGH MOST
OF TONIGHT EVEN AS LOW PRESSURE TROUGH WORKS ACROSS THE LAKE. STRONGER
COLD FRONT SWEEPS OVER LK SUPERIOR LATE TONIGHT AND EXPECT WINDS TO
SHIFT TO THE NORTH AND PEAK AROUND 30 KTS AROUND SUNRISE ON MONDAY...BEFORE
QUICKLY DIMINISHING TO LESS THAN 20 KTS ON MONDAY AFTN. HEAVY FREEZING
SPRAY WILL RETURN LATE TONIGHT BUT UNLIKE LAST WEEK...IT WILL NOT
LAST LONG...ENDING BY MONDAY EVENING AS HIGH PRESSURE DRIFTS ACROSS.
WINDS WILL INCREASE AGAIN LATE MONDAY NIGHT INTO TUESDAY OUT OF THE
SOUTHWEST. STRONGEST WINDS TO 30 KTS EXPECTED OVER WESTERN AND NORTH
CENTRAL LK SUPERIOR. COULD SEE GALE GUSTS TUESDAY AFTN INTO TUESDAY
EVENING BTWN TIP OF KEWEENAW AND ISLE ROYALE. HEAVY FREEZING SPRAY IS
NOT EXPECTED AS WILL BE HIGHER THAN SEEN RECENTLY. WINDS DIMINISH TO
25 KTS OR LESS BY WEDNESDAY AND SHOULD REMAIN AT SIMILAR SPEEDS
THROUGH LATE THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST MONDAY FOR MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 4 PM EST MONDAY FOR
LSZ248>251-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM TO 1 PM EST MONDAY FOR
LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 1 PM EST MONDAY FOR
LSZ242-263.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KF
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
653 AM EST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST SUN JAN 11 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF PERSISTING
OVER ERN NAMERICA. HOWEVER...HEIGHTS HAVE BEEN RISING SIGNIFICANTLY
OVER THE ERN CONUS (00Z RAOBS SHOW 12HR 500MB HEIGHT RISES OF
100-200M FROM THE UPPER MISSISSIPPI VALLEY TO THE E COAST)...
INDICATING A RELAXATION OF THE RECENT VERY COLD PATTERN. UPSTREAM...
A SHORTWAVE TROF IS DROPPING S INTO SASKATCHEWAN/MANITOBA. THIS WILL
BE THE MAIN FEATURE OF INTEREST IN THE SHORT TERM AS IT SWINGS SE
INTO THE UPPER GREAT LAKES LATE TONIGHT/MON MORNING. 850MB TEMPS ARE
CURRENTLY AROUND -18C PER LATEST RUC ANALYSIS...AND THIS IS
CONTINUING TO SUPPORT LES OVER LAKE SUPERIOR. A SFC TROF...ENHANCED
BY THE RELATIVELY WARM WATERS...EXTENDS ACROSS LAKE SUPERIOR EARLY
THIS MORNING. OVER WRN LAKE SUPERIOR...LAND BREEZE ENHANCED FLOW
AHEAD OF TROF IS FOCUSING LES MOSTLY OFFSHORE OF WRN UPPER MI...
EXCEPT OVER THE KEWEENAW. TO THE E...LES IS WELL OFFSHORE WITH HINTS
OF A CONVERGENT DOMINANT BAND ALONG TROF TO THE E OF STANNARD ROCK.
MODELS SHOW THE SFC TROF CURRENTLY OVER LAKE SUPERIOR WEAKENING AND
DRIFTING SE TODAY. OVER WRN LAKE SUPERIOR...NOT MUCH CHANGE IN WIND
DIRECTION IS INDICATED AS THIS OCCURS. OVER ERN LAKE SUPERIOR...LES
WILL DRIFT SLOWLY S AS WINDS BECOME MORE WNW. AS A RESULT...SCT TO
NMRS -SHSN WILL LINGER OVER NW UPPER MI TODAY...MAINLY THE
KEWEENAW...WHILE TO THE E...-SHSN SHOULD SETTLE/DEVELOP SE AND AT
LEAST BRUSH THE SHORE E OF MUNISING. -SHSN WON`T PUSH TOO FAR INLAND
SINCE THERE IS LITTLE N COMPONENT TO THE WIND. WITH INVERSION AT
3-4KFT...LES WILL BE ON THE LIGHT SIDE. DGZ DOES DOMINATE THE
CONVECTIVE LAYER THOUGH...AND THIS WILL LEAD TO HIGHER SNOW TO WATER
RATIOS. MIGHT SEE A COUPLE OF INCHES WHERE LES IS MOST PERSISTENT
TODAY. MEANWHILE...AHEAD OF THE APPROACHING SHORTWAVE TROF...MODELS
SHOW STRENGTHENING OF A JET STREAK FROM NRN MN TO NEW ENGLAND/SRN
QUEBEC TODAY. RIGHT ENTRANCE OF THIS JET MAY PROVIDE SUFFICIENT
FORCING FOR A STREAK OF -SN/FLURRIES TO DEVELOP AND SPREAD FROM MN
TO NRN WI/SRN UPPER MI LATE THIS AFTN/EVENING. OVER THE LAST DAY OR
SO...ALL MODEL GUIDANCE HAS TRENDED TOWARD SHOWING THIS STREAK OF
-SN. LOW-LEVEL DRY AIR WILL BE A HINDRANCE...BUT GIVEN MODEL
TRENDS...AT LEAST SCHC POPS ARE WARRANTED LATE AFTN/EVENING ACROSS
THE SRN FCST AREA.
TONIGHT...SHORTWAVE WILL SWING SE...PASSING ACROSS THE UPPER LAKES
LATE TONIGHT/MON MORNING. SINCE BULK OF THE DEEP LAYER FORCING
PASSES TO THE NE AND THERE IS AN ABSENCE OF ANY MOISTURE INFLOW IN
ADVANCE OF THIS DISTURBANCE...ACCOMPANYING PCPN SHOULD BE LIMITED TO
AREAS NEAR LAKE SUPERIOR. VEERING FLOW TO THE NW AND 850MB TEMPS
FALLING BACK TO -20 TO -24C BY 12Z MON IN THE WAKE OF ATTENDANT COLD
FROPA WILL BRING AN INCREASE IN LES TONIGHT INTO MON MORNING.
GFS/NAM FCST SOUNDINGS SHOW LIMITED IMPACT ON INVERSION...ONLY
RISING TO NEAR 5KFT...WHICH IS A LITTLE SURPRISING SINCE THE DEEP
LAYER FORCING PER QVECTORS IS NOT THAT WEAK. FORCING AND DEGREE OF
OVERWATER INSTABILITY WARRANTS CATEGORICAL POPS FOR AREAS FAVORED BY
NW WINDS TONIGHT. FOR NOW...EXPECT 1-3 INCHES OF SNOW BY DAYBREAK
MON. THE LONGER FETCH INTO NCNTRL UPPER MI AND DEEPER DGZ THERE
SUGGEST GREATER COVERAGE OF 2-3 INCH AMOUNTS WILL BE FROM MUNISING
EASTWARD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 438 AM EST SUN JAN 11 2015
DECENT AGREEMENT THAT LARGE TROUGH OVER EASTERN CANADA GRADUALLY
LOSES ITS INFLUENCE OVER THE GREAT LAKES BY NEXT WEEKEND. A COUPLE OF
LAST PUSHES OF ARCTIC AIR WILL GIVE UPPER GREAT LAKES GLANCING BLOWS
OF COLDER TEMPS...FIRST ON MONDAY...THEN AGAIN ON THURSDAY. BY NEXT
WEEKEND ZONAL FLOW IS IN FULL SWING AS STRONG JET STREAK PLOWING
ACROSS THE PACIFIC MASHES HEIGHTS DOWN OVER THE WESTERN CONUS. H85
TEMPS AS LOW AS -24C ON MONDAY MORNING WILL BE REPLACED WITH VALUES
RISING ABOVE ZERO ON FRIDAY. EXPECT TEMPS TO BE WELL INTO THE 20S AT
THE SFC BY THE TIME WE REACH LATE THIS WEEK.
INITIAL BATCH OF COLD AIR TIED TO SHORTWAVE DROPPING OVER THE AREA
TONIGHT RESULTS IN LAKE EFFECT SNOW SHOWERS KICKING UP IN NNW-N FLOW
INTO MONDAY MORNING. LIMITED DIRECT IMPACT FM THE SHORTWAVE TO
ENHANCE THE LES. INVERSIONS UP TO 5KFT AND GENERAL UNIDIRECTIONAL
FLOW WITHIN THE CLOUD LAYER WILL AID IN ORGANIZATION. SINCE MUCH OF
CLOUD LAYER IS WITHIN THE DGZ COULD SEE FEW INCHES OF FLUFFY
ACCUMULATION. A NEGATIVE FACTOR WILL BE BLYR WINDS STEADILY VEERING
FM NW TO NNE LATE TONIGHT INTO MONDAY MORNING WHICH WILL NOT ALLOW
THE BANDS TO AFFECT ANY ONE LOCATION FOR TOO LONG OF A DURATION.
TIMING WILL MATTER AS IF THE STRONGER LES DROPS ALONG LK SUPERIOR
EARLIER ON MONDAY...THEN THE MORNING COMMUTE WOULD BE IMPACTED. MAY
MENTION IN HWO...BUT OVERALL SEEMS LIKE MAY BE ABLE TO GET BY WITHOUT
HAVING A HEADLINE FOR THE LES. INVERSIONS LOWER FURTHER BY MONDAY
AFTN BELOW 5KFT AND LOW-LEVEL CONVERGENCE WEAKENS AS LARGE HIGH
PRESSURE RIDGE OVER 1040MB BUILDS FM THE NORTHERN PLAINS TOWARD THE
WESTERN GREAT LAKES...SO LES WILL CONTINUE TO TREND DOWNWARD IN
INTENSITY.
BY MONDAY NIGHT WHATEVER IS LEFT OF THE LES SHOULD BE SPUTTERING
ALONG AS MAINLY FLURRIES FOR THE SNOW BELTS EAST OF MARQUETTE AS
WINDS BACK NW. RIDGE/DRY AIR AND CONTINUAL BACKING WINDS WILL END
LES OVERNIGHT. CALM BUT COLD CONDITIONS INLAND WITH THE RIDGING
OVERHEAD. A BIT MORE OF A GRADIENT WSW WIND KEEPS TEMPS NOT AS COLD
OVER THE KEWEENAW AND NEAR LK SUPERIOR. INLAND THOUGH...PWATS LESS
THAN 0.10 INCH AND CALM CONDITIONS WILL RESULT IN PRIME RADIATIONAL
COOLING WITH TYPICAL COLD SPOTS POSSIBLY DROPPING TO READINGS LOWER
THAN 20 BLO. THANKFULLY NO WIND CHILL ISSUES AS IT SHOULD BE CALM
WHERE TEMPS ARE THAT LOW.
RIDGE STILL ENOUGH IN VCNTY TUESDAY TO LIMIT MIXING DEPTH AND THUS
KEEP MAX TEMPS IN THE LOW-MID TEENS. EXCEPTION WILL BE ALONG LK
SUPERIOR WEST THROUGH NCNTRL WHERE WSW FLOW PROVIDES SOME DOWNSLOPE
WARMING AND COULD BOOST TEMPS ABOVE 20 DEGREES. A RELATIVE HEAT
WAVE COMPARED TO THE CHILL THAT HAS BEEN AROUND THE LAST WEEK OR SO.
WSW WINDS MAY GET GUSTY OVER LK SUPERIOR AND KEWEENAW ON TUESDAY
NIGHT. MAY SEE WINDS OVER 30 MPH FOR PARTS OF THE KEWEENAW. WINDS MAY
STAY STRONG ENOUGH TO RESULT IN TEMPS NEAR LK SUPERIOR STAYING STEADY
OR ONLY SLIGHTLY FALLING. INLAND OVER WEST HALF...BLENDED BACK TOWARD
GOING FORECAST WITH MINS SLIPPING BLO ZERO AS IT WOULD NOT TAKE MUCH
DECOUPLING TO HAVE TEMPS FALL OFF IN INTERIOR SHELTERED AREAS. COULD
SEE DECENT RANGE IN MIN TEMPS OVR THE CWA THIS NIGHT.
WEAK LOW PRESSURE TROUGH...EXTENSION FM STRONGER LOW PRESSURE TIED
TO SHORTWAVE OVER NORTHERN ONTARIO...CROSSES LK SUPERIOR ON
WEDNESDAY. GIVEN WEST-SOUTHWEST WINDS...BEST CHANCE OF ANY LGT SNOW
WOULD BE ON THE KEWEENAW. ONCE THE TROUGH SLIDES FARTHER OVER THE
AREA ON WEDNESDAY NIGHT INTO THURSDAY...SHOWED CHANCES ALONG MUCH OF
THE NORTHERN CWA. MARGINAL FM A STRICT LES STANDPOINT WITH H85 TEMPS
ONLY AROUND -12C...BUT BOTH GFS AND ECMWF HINT AT ADDITIONAL FORCING
AND MOISTENING...SO COULD BE LAKE ENHANCED SNOW FOR AT LEAST A BRIEF
PERIOD. TROUGH THEN BOUNCES EAST ON FRIDAY AND MAY EVEN TAKE SHAPE
AS A WARM FRONT...AT LEAST ALOFT. DOES SEEM THAT GFS AND ECMWF HINT
THAT THERE WOULD BE SW-W WINDS FOR FRIDAY WITH H85 TEMPS WARMING
ABOVE 0C. GFS SOUNDINGS INDICATE SHALLOW MIXING HEIGHT WITH MOST OF
THE WARMING STAYING ALOFT. INCREASED TEMPS A BIT OVER CONSENSUS WITH
THE HINTS SHOWING UP AND HAVE MID 20S INLAND AND A SHOT AT CRACKING
30 DEGREES ALONG LK SUPERIOR WITH THE SW WINDS. RAN TEMPS UP TO 30
DEGREES FOR NOW...BUT BIAS CORRECTED ECMWF GUIDANCE DID HAVE EVEN
MID 30S. LIKELY WOULD NEED TO HAVE DECENT SUNSHINE/MIXING FOR THAT
TO HAPPEN...BUT FOR NOW INCHED HIGH TEMPS UP SOME. LAST TIME NWS
OFFICE IN NEGAUNEE TOWNSHIP SAW A HIGH TEMP OF 30 DEGREES WAS JUST
AFTER CHRISTMAS ON THE MORNING OF 27 DEC. TEMPS WENT IN A FREE FALL
AFTER THAT THOUGH AND HAVE ONLY BEEN ABOVE 20 DEGREES DURING THE
DAYTIME HOURS ON ONE DAY...3 JAN. A FEW DAYS WITH HIGHS IN THE 20S
WOULD BE QUITE WELCOME.
NO ADJUSTMENTS TO CONSENSUS FORECAST FOR NEXT WEEKEND AS ECMWF IS
TRYING TO SHOW A STRONGER/DIGGIER SHORTWAVE AND STRONGER COLD FRONT
PASSAGE...WHILE THE GFS TURNS MORE PROGRESSIVE AND KEEPS TROUGH TO
THE NORTH SO THUS ANOTHER WARMER DAY. GEM-NH ON ITS LAST PANEL AT 00Z
SAT 17 JAN LOOKS MORE LIKE THE GFS. USED A BLEND FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 652 AM EST SUN JAN 11 2015
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO AFFECT KCMX TODAY UNDER
WNW WINDS. THERE IS SOME UNCERTAINTY IN VIS/CIG IMPACTS...BUT SINCE
CONDITIONS FAVOR MOSTLY LIGHT PCPN...EXPECT MVFR CONDITIONS TO
PREVAIL WITH SOME BRIEF PERIODS OF IFR. COLD FRONT PASSING THIS
EVENING WILL LIKELY BRING A PERIOD OF IFR CONDITIONS TO KCMX...AND
POTENTIALLY LIFR. AS WINDS SHIFT TOWARD A NORTHERLY DIRECTION
OVERNIGHT WHICH IS TYPICALLY LESS FAVORABLE FOR POOR
CONDITIONS/PERSISTENT HEAVIER SNOW SHOWERS AT KCMX...EXPECT MVFR
CONDITIONS TO RETURN. AT KIWD/KSAW...VFR CONDITIONS WILL PREVAIL
INTO THE EVENING HRS AS LOW-LEVEL AIR MASS REMAINS RELATIVELY DRY.
AS WINDS SHIFT NW TONIGHT IN ASSOCIATION WITH COLD FROPA...LAKE
EFFECT SNOW SHOWERS WILL INCREASE AT KIWD...DROPPING CONDITIONS TO
IFR LATE. AT KSAW...EXPECT MVFR CONDITIONS TO DEVELOP OVERNIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EST SUN JAN 11 2015
WINDS HAVE DIMINISHED BLO 25 KTS AND WILL STAY THAT WAY THROUGH MOST
OF TONIGHT EVEN AS LOW PRESSURE TROUGH WORKS ACROSS THE LAKE. STRONGER
COLD FRONT SWEEPS OVER LK SUPERIOR LATE TONIGHT AND EXPECT WINDS TO
SHIFT TO THE NORTH AND PEAK AROUND 30 KTS AROUND SUNRISE ON MONDAY...BEFORE
QUICKLY DIMINISHING TO LESS THAN 20 KTS ON MONDAY AFTN. HEAVY FREEZING
SPRAY WILL RETURN LATE TONIGHT BUT UNLIKE LAST WEEK...IT WILL NOT
LAST LONG...ENDING BY MONDAY EVENING AS HIGH PRESSURE DRIFTS ACROSS.
WINDS WILL INCREASE AGAIN LATE MONDAY NIGHT INTO TUESDAY OUT OF THE
SOUTHWEST. STRONGEST WINDS TO 30 KTS EXPECTED OVER WESTERN AND NORTH
CENTRAL LK SUPERIOR. COULD SEE GALE GUSTS TUESDAY AFTN INTO TUESDAY
EVENING BTWN TIP OF KEWEENAW AND ISLE ROYALE. HEAVY FREEZING SPRAY IS
NOT EXPECTED AS WILL BE HIGHER THAN SEEN RECENTLY. WINDS DIMINISH TO
25 KTS OR LESS BY WEDNESDAY AND SHOULD REMAIN AT SIMILAR SPEEDS
THROUGH LATE THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 4 PM EST MONDAY FOR
LSZ248>251-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM TO 1 PM EST MONDAY FOR
LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 1 PM EST MONDAY FOR
LSZ242-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
518 AM EST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST SUN JAN 11 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF PERSISTING
OVER ERN NAMERICA. HOWEVER...HEIGHTS HAVE BEEN RISING SIGNIFICANTLY
OVER THE ERN CONUS (00Z RAOBS SHOW 12HR 500MB HEIGHT RISES OF
100-200M FROM THE UPPER MISSISSIPPI VALLEY TO THE E COAST)...
INDICATING A RELAXATION OF THE RECENT VERY COLD PATTERN. UPSTREAM...
A SHORTWAVE TROF IS DROPPING S INTO SASKATCHEWAN/MANITOBA. THIS WILL
BE THE MAIN FEATURE OF INTEREST IN THE SHORT TERM AS IT SWINGS SE
INTO THE UPPER GREAT LAKES LATE TONIGHT/MON MORNING. 850MB TEMPS ARE
CURRENTLY AROUND -18C PER LATEST RUC ANALYSIS...AND THIS IS
CONTINUING TO SUPPORT LES OVER LAKE SUPERIOR. A SFC TROF...ENHANCED
BY THE RELATIVELY WARM WATERS...EXTENDS ACROSS LAKE SUPERIOR EARLY
THIS MORNING. OVER WRN LAKE SUPERIOR...LAND BREEZE ENHANCED FLOW
AHEAD OF TROF IS FOCUSING LES MOSTLY OFFSHORE OF WRN UPPER MI...
EXCEPT OVER THE KEWEENAW. TO THE E...LES IS WELL OFFSHORE WITH HINTS
OF A CONVERGENT DOMINANT BAND ALONG TROF TO THE E OF STANNARD ROCK.
MODELS SHOW THE SFC TROF CURRENTLY OVER LAKE SUPERIOR WEAKENING AND
DRIFTING SE TODAY. OVER WRN LAKE SUPERIOR...NOT MUCH CHANGE IN WIND
DIRECTION IS INDICATED AS THIS OCCURS. OVER ERN LAKE SUPERIOR...LES
WILL DRIFT SLOWLY S AS WINDS BECOME MORE WNW. AS A RESULT...SCT TO
NMRS -SHSN WILL LINGER OVER NW UPPER MI TODAY...MAINLY THE
KEWEENAW...WHILE TO THE E...-SHSN SHOULD SETTLE/DEVELOP SE AND AT
LEAST BRUSH THE SHORE E OF MUNISING. -SHSN WON`T PUSH TOO FAR INLAND
SINCE THERE IS LITTLE N COMPONENT TO THE WIND. WITH INVERSION AT
3-4KFT...LES WILL BE ON THE LIGHT SIDE. DGZ DOES DOMINATE THE
CONVECTIVE LAYER THOUGH...AND THIS WILL LEAD TO HIGHER SNOW TO WATER
RATIOS. MIGHT SEE A COUPLE OF INCHES WHERE LES IS MOST PERSISTENT
TODAY. MEANWHILE...AHEAD OF THE APPROACHING SHORTWAVE TROF...MODELS
SHOW STRENGTHENING OF A JET STREAK FROM NRN MN TO NEW ENGLAND/SRN
QUEBEC TODAY. RIGHT ENTRANCE OF THIS JET MAY PROVIDE SUFFICIENT
FORCING FOR A STREAK OF -SN/FLURRIES TO DEVELOP AND SPREAD FROM MN
TO NRN WI/SRN UPPER MI LATE THIS AFTN/EVENING. OVER THE LAST DAY OR
SO...ALL MODEL GUIDANCE HAS TRENDED TOWARD SHOWING THIS STREAK OF
-SN. LOW-LEVEL DRY AIR WILL BE A HINDRANCE...BUT GIVEN MODEL
TRENDS...AT LEAST SCHC POPS ARE WARRANTED LATE AFTN/EVENING ACROSS
THE SRN FCST AREA.
TONIGHT...SHORTWAVE WILL SWING SE...PASSING ACROSS THE UPPER LAKES
LATE TONIGHT/MON MORNING. SINCE BULK OF THE DEEP LAYER FORCING
PASSES TO THE NE AND THERE IS AN ABSENCE OF ANY MOISTURE INFLOW IN
ADVANCE OF THIS DISTURBANCE...ACCOMPANYING PCPN SHOULD BE LIMITED TO
AREAS NEAR LAKE SUPERIOR. VEERING FLOW TO THE NW AND 850MB TEMPS
FALLING BACK TO -20 TO -24C BY 12Z MON IN THE WAKE OF ATTENDANT COLD
FROPA WILL BRING AN INCREASE IN LES TONIGHT INTO MON MORNING.
GFS/NAM FCST SOUNDINGS SHOW LIMITED IMPACT ON INVERSION...ONLY
RISING TO NEAR 5KFT...WHICH IS A LITTLE SURPRISING SINCE THE DEEP
LAYER FORCING PER QVECTORS IS NOT THAT WEAK. FORCING AND DEGREE OF
OVERWATER INSTABILITY WARRANTS CATEGORICAL POPS FOR AREAS FAVORED BY
NW WINDS TONIGHT. FOR NOW...EXPECT 1-3 INCHES OF SNOW BY DAYBREAK
MON. THE LONGER FETCH INTO NCNTRL UPPER MI AND DEEPER DGZ THERE
SUGGEST GREATER COVERAGE OF 2-3 INCH AMOUNTS WILL BE FROM MUNISING
EASTWARD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 438 AM EST SUN JAN 11 2015
DECENT AGREEMENT THAT LARGE TROUGH OVER EASTERN CANADA GRADUALLY
LOSES ITS INFLUENCE OVER THE GREAT LAKES BY NEXT WEEKEND. A COUPLE OF
LAST PUSHES OF ARCTIC AIR WILL GIVE UPPER GREAT LAKES GLANCING BLOWS
OF COLDER TEMPS...FIRST ON MONDAY...THEN AGAIN ON THURSDAY. BY NEXT
WEEKEND ZONAL FLOW IS IN FULL SWING AS STRONG JET STREAK PLOWING
ACROSS THE PACIFIC MASHES HEIGHTS DOWN OVER THE WESTERN CONUS. H85
TEMPS AS LOW AS -24C ON MONDAY MORNING WILL BE REPLACED WITH VALUES
RISING ABOVE ZERO ON FRIDAY. EXPECT TEMPS TO BE WELL INTO THE 20S AT
THE SFC BY THE TIME WE REACH LATE THIS WEEK.
INITIAL BATCH OF COLD AIR TIED TO SHORTWAVE DROPPING OVER THE AREA
TONIGHT RESULTS IN LAKE EFFECT SNOW SHOWERS KICKING UP IN NNW-N FLOW
INTO MONDAY MORNING. LIMITED DIRECT IMPACT FM THE SHORTWAVE TO
ENHANCE THE LES. INVERSIONS UP TO 5KFT AND GENERAL UNIDIRECTIONAL
FLOW WITHIN THE CLOUD LAYER WILL AID IN ORGANIZATION. SINCE MUCH OF
CLOUD LAYER IS WITHIN THE DGZ COULD SEE FEW INCHES OF FLUFFY
ACCUMULATION. A NEGATIVE FACTOR WILL BE BLYR WINDS STEADILY VEERING
FM NW TO NNE LATE TONIGHT INTO MONDAY MORNING WHICH WILL NOT ALLOW
THE BANDS TO AFFECT ANY ONE LOCATION FOR TOO LONG OF A DURATION.
TIMING WILL MATTER AS IF THE STRONGER LES DROPS ALONG LK SUPERIOR
EARLIER ON MONDAY...THEN THE MORNING COMMUTE WOULD BE IMPACTED. MAY
MENTION IN HWO...BUT OVERALL SEEMS LIKE MAY BE ABLE TO GET BY WITHOUT
HAVING A HEADLINE FOR THE LES. INVERSIONS LOWER FURTHER BY MONDAY
AFTN BELOW 5KFT AND LOW-LEVEL CONVERGENCE WEAKENS AS LARGE HIGH
PRESSURE RIDGE OVER 1040MB BUILDS FM THE NORTHERN PLAINS TOWARD THE
WESTERN GREAT LAKES...SO LES WILL CONTINUE TO TREND DOWNWARD IN
INTENSITY.
BY MONDAY NIGHT WHATEVER IS LEFT OF THE LES SHOULD BE SPUTTERING
ALONG AS MAINLY FLURRIES FOR THE SNOW BELTS EAST OF MARQUETTE AS
WINDS BACK NW. RIDGE/DRY AIR AND CONTINUAL BACKING WINDS WILL END
LES OVERNIGHT. CALM BUT COLD CONDITIONS INLAND WITH THE RIDGING
OVERHEAD. A BIT MORE OF A GRADIENT WSW WIND KEEPS TEMPS NOT AS COLD
OVER THE KEWEENAW AND NEAR LK SUPERIOR. INLAND THOUGH...PWATS LESS
THAN 0.10 INCH AND CALM CONDITIONS WILL RESULT IN PRIME RADIATIONAL
COOLING WITH TYPICAL COLD SPOTS POSSIBLY DROPPING TO READINGS LOWER
THAN 20 BLO. THANKFULLY NO WIND CHILL ISSUES AS IT SHOULD BE CALM
WHERE TEMPS ARE THAT LOW.
RIDGE STILL ENOUGH IN VCNTY TUESDAY TO LIMIT MIXING DEPTH AND THUS
KEEP MAX TEMPS IN THE LOW-MID TEENS. EXCEPTION WILL BE ALONG LK
SUPERIOR WEST THROUGH NCNTRL WHERE WSW FLOW PROVIDES SOME DOWNSLOPE
WARMING AND COULD BOOST TEMPS ABOVE 20 DEGREES. A RELATIVE HEAT
WAVE COMPARED TO THE CHILL THAT HAS BEEN AROUND THE LAST WEEK OR SO.
WSW WINDS MAY GET GUSTY OVER LK SUPERIOR AND KEWEENAW ON TUESDAY
NIGHT. MAY SEE WINDS OVER 30 MPH FOR PARTS OF THE KEWEENAW. WINDS MAY
STAY STRONG ENOUGH TO RESULT IN TEMPS NEAR LK SUPERIOR STAYING STEADY
OR ONLY SLIGHTLY FALLING. INLAND OVER WEST HALF...BLENDED BACK TOWARD
GOING FORECAST WITH MINS SLIPPING BLO ZERO AS IT WOULD NOT TAKE MUCH
DECOUPLING TO HAVE TEMPS FALL OFF IN INTERIOR SHELTERED AREAS. COULD
SEE DECENT RANGE IN MIN TEMPS OVR THE CWA THIS NIGHT.
WEAK LOW PRESSURE TROUGH...EXTENSION FM STRONGER LOW PRESSURE TIED
TO SHORTWAVE OVER NORTHERN ONTARIO...CROSSES LK SUPERIOR ON
WEDNESDAY. GIVEN WEST-SOUTHWEST WINDS...BEST CHANCE OF ANY LGT SNOW
WOULD BE ON THE KEWEENAW. ONCE THE TROUGH SLIDES FARTHER OVER THE
AREA ON WEDNESDAY NIGHT INTO THURSDAY...SHOWED CHANCES ALONG MUCH OF
THE NORTHERN CWA. MARGINAL FM A STRICT LES STANDPOINT WITH H85 TEMPS
ONLY AROUND -12C...BUT BOTH GFS AND ECMWF HINT AT ADDITIONAL FORCING
AND MOISTENING...SO COULD BE LAKE ENHANCED SNOW FOR AT LEAST A BRIEF
PERIOD. TROUGH THEN BOUNCES EAST ON FRIDAY AND MAY EVEN TAKE SHAPE
AS A WARM FRONT...AT LEAST ALOFT. DOES SEEM THAT GFS AND ECMWF HINT
THAT THERE WOULD BE SW-W WINDS FOR FRIDAY WITH H85 TEMPS WARMING
ABOVE 0C. GFS SOUNDINGS INDICATE SHALLOW MIXING HEIGHT WITH MOST OF
THE WARMING STAYING ALOFT. INCREASED TEMPS A BIT OVER CONSENSUS WITH
THE HINTS SHOWING UP AND HAVE MID 20S INLAND AND A SHOT AT CRACKING
30 DEGREES ALONG LK SUPERIOR WITH THE SW WINDS. RAN TEMPS UP TO 30
DEGREES FOR NOW...BUT BIAS CORRECTED ECMWF GUIDANCE DID HAVE EVEN
MID 30S. LIKELY WOULD NEED TO HAVE DECENT SUNSHINE/MIXING FOR THAT
TO HAPPEN...BUT FOR NOW INCHED HIGH TEMPS UP SOME. LAST TIME NWS
OFFICE IN NEGAUNEE TOWNSHIP SAW A HIGH TEMP OF 30 DEGREES WAS JUST
AFTER CHRISTMAS ON THE MORNING OF 27 DEC. TEMPS WENT IN A FREE FALL
AFTER THAT THOUGH AND HAVE ONLY BEEN ABOVE 20 DEGREES DURING THE
DAYTIME HOURS ON ONE DAY...3 JAN. A FEW DAYS WITH HIGHS IN THE 20S
WOULD BE QUITE WELCOME.
NO ADJUSTMENTS TO CONSENSUS FORECAST FOR NEXT WEEKEND AS ECMWF IS
TRYING TO SHOW A STRONGER/DIGGIER SHORTWAVE AND STRONGER COLD FRONT
PASSAGE...WHILE THE GFS TURNS MORE PROGRESSIVE AND KEEPS TROUGH TO
THE NORTH SO THUS ANOTHER WARMER DAY. GEM-NH ON ITS LAST PANEL AT 00Z
SAT 17 JAN LOOKS MORE LIKE THE GFS. USED A BLEND FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1246 AM EST SUN JAN 11 2015
ALTHOUGH WRLY FLOW LES OVER THE KEWEENAW HAS SHIFTED NORTH OF
CMX...EXPECT THAT THE AREA OF FAVORABLE LOW LEVEL CONV WILL DROP
BACK TO THE SOUTH OVERNIGHT...BRINGING LIGHT LES BACK INTO CMX. WITH
THE GENERALLY LIGHT WINDS...THERE IS MORE UNCERTAINTY ON WHERE THE
LES BANDS WILL DEVELOP AND HOW LONG THEY WILL PERSIST AT THE
TERMINAL. HOWEVER...THERE IS SUFFICIENT INSTABILITY TO SUPPORT LES
INTO THE IFR RANGE TODAY AS WEST WINDS INCREASE. WINDS WILL VEER TO
THE NW BY LATE EVENING BEHIND A COLD FRONT AND BECOME MORE GUSTY.
FOR KIWD/KSAW...EXPECT VFR CONDITIONS TO PREVAIL FOR THE TAF PERIOD.
ONLY OCCASIONAL MID/HIGH CLOUDS ARE EXPECTED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EST SUN JAN 11 2015
WINDS HAVE DIMINISHED BLO 25 KTS AND WILL STAY THAT WAY THROUGH MOST
OF TONIGHT EVEN AS LOW PRESSURE TROUGH WORKS ACROSS THE LAKE. STRONGER
COLD FRONT SWEEPS OVER LK SUPERIOR LATE TONIGHT AND EXPECT WINDS TO
SHIFT TO THE NORTH AND PEAK AROUND 30 KTS AROUND SUNRISE ON MONDAY...BEFORE
QUICKLY DIMINISHING TO LESS THAN 20 KTS ON MONDAY AFTN. HEAVY FREEZING
SPRAY WILL RETURN LATE TONIGHT BUT UNLIKE LAST WEEK...IT WILL NOT
LAST LONG...ENDING BY MONDAY EVENING AS HIGH PRESSURE DRIFTS ACROSS.
WINDS WILL INCREASE AGAIN LATE MONDAY NIGHT INTO TUESDAY OUT OF THE
SOUTHWEST. STRONGEST WINDS TO 30 KTS EXPECTED OVER WESTERN AND NORTH
CENTRAL LK SUPERIOR. COULD SEE GALE GUSTS TUESDAY AFTN INTO TUESDAY
EVENING BTWN TIP OF KEWEENAW AND ISLE ROYALE. HEAVY FREEZING SPRAY IS
NOT EXPECTED AS WILL BE HIGHER THAN SEEN RECENTLY. WINDS DIMINISH TO
25 KTS OR LESS BY WEDNESDAY AND SHOULD REMAIN AT SIMILAR SPEEDS
THROUGH LATE THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 4 PM EST MONDAY FOR
LSZ248>251-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM TO 1 PM EST MONDAY FOR
LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 1 PM EST MONDAY FOR
LSZ242-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1158 PM EST SAT JAN 10 2015
.AVIATION...
VFR CEILING ABOVE 5000 FEET WILL PERSIST THROUGH THE MORNING AND
THEN GIVE WAY TO HIGHER CLOUDS BEFORE THE NEXT LOW PRESSURE SYSTEM
ARRIVES SUNDAY NIGHT. RADAR RETURNS PROVED TO BE MOSTLY VIRGA DURING
THE EVENING AND WILL DIMINISH DURING THE REST OF THE NIGHT. MBS ALSO
REPORTED 1 HOUR OF MVFR CEILING DURING THE EVENING ON THE EDGE OF
THE LAKE CLOUD PLUME STREAMING INTO NORTHERN LOWER MICHIGAN. THAT IS
WHERE THE BULK OF MVFR CEILING WILL REMAIN THROUGH THE DAY. EXPECT
VFR TO PERSIST ALL AREAS UNTIL SNOW MOVES IN WITH THE NEXT SYSTEM
TOWARD SUNDAY EVENING. IFR RESTRICTION DOWN TO 1 MILE LOOKS LIKELY
WITH THIS PATTERN EXCEPT MBS BEING ON THE EDGE IS MORE LIKELY TO SEE
MVFR.
FOR DTW... MOSTLY VIRGA INDICATED BY RADAR DURING THE EVENING DID
MANAGE A 10SM -SN REPORT AT DTW...AND HELPED TAKE CEILING DOWN TO
5000 FT FOR A SHORT PERIOD. THIS MOISTURE WILL EXIT EASTWARD WITH A
VFR CEILING REBOUND ABOVE 5000 FEET THROUGH THE MORNING. SNOW IS
EXPECTED TO DEVELOP BY LATE AFTERNOON AND LAST THROUGH SUNDAY NIGHT.
IFR/LIFR RESTRICTION IS LIKELY AND MODERATE POTENTIAL FOR
ACCUMULATION IN THE 1-2 INCH RANGE.
//DTW THRESHOLD PROBABILITIES...
* HIGH PROBABILITY FOR SNOW AS PRECIPITATION TYPE SUNDAY NIGHT.
&&
.PREV DISCUSSION...ISSUED 334 PM EST SAT JAN 10 2015
SHORT TERM...TONIGHT
SE MICHIGAN WILL EASE INTO MORE OF A QUASI-ZONAL SLIGHTLY CONFLUENT
MID LEVEL FLOW TONIGHT...BASE OF THE PREDOMINANT CENTRAL CANADIAN
TROUGH DICTATING CONDITIONS RECENTLY FINALLY RELEASING NORTH AND
EAST. A TRANSITION TOWARD LOW LEVEL SOUTH-SOUTHWEST FLOW WILL
INITIATE THE EARLY STAGES OF A PERIOD OF WARM AIR ADVECTION THAT
WILL PERSIST THROUGH THE REMAINDER OF THE WEEKEND. VERY LIMITED
MOISTURE RETURN NOTED UPSTREAM THIS AFTERNOON WITHIN THE ENSUING
BROADENING ISENTROPIC ASCENT TIED TO THIS PROCESS. DESPITE THE
GENERAL WARMING THROUGH THE THERMAL PROFILE...THERE WILL REMAIN SOME
PERPETUATION OF THE ONGOING WEAK LAKE MOISTURE FLUX. THIS WILL
CONTRIBUTE SLIGHTLY TO THE OVERALL MOISTURE QUALITY NORTH OF THE I-
69 CORRIDOR... PROVIDING A WINDOW FOR SOME ADDITIONAL LIGHT SNOW
SHOWER DEVELOPMENT TONIGHT. ELSEWHERE LITTLE MORE THAN
FLURRIES...RECENT NAM AND RAP SOUNDING DATA STILL LEAVE A HEALTHY
DRY LAYER WITHIN THE LOWEST 4000 FT THROUGH THE NIGHT.
EXISTING ENVIRONMENT REMAINS FAVORABLE FOR A GOOD NOCTURNAL COOLING
RESPONSE THIS EVENING...PARTICULARLY SOUTHERN/CENTRAL SECTIONS WHERE
SKIES ARE NOW CLEAR. THIS WILL BRING LOWS IN MANY LOCALES INTO THE
SINGLE DIGITS EARLY TONIGHT. A THICKENING CLOUD DECK AND SOME
INCREASE IN THE SOUTHWEST GRADIENT WILL THEN ALLOW TEMPERATURES TO
RISE GRADUALLY HEADING INTO THE EARLY MORNING PERIOD. TEMPERATURES
BACK INTO LOW-MID TEENS BY DAYBREAK.
LONG TERM...
THE SQUEEZE PLAY LOOKS TO BE ON LATE TOMORROW/TOMORROW NIGHT AS
UPPER WAVE AND ASSOCIATED MOISTURE OVER TEXAS MAKES A RUN NORTHEAST
TOWARD THE CENTRAL GREAT LAKES. AT THE SAME TIME...ANOTHER STRONG
NORTHERN STREAM TROUGH WILL BE DROPPING SOUTHEAST FROM CENTRAL
CANADA. THE TROUGH AXIS IS DISTINCTLY POSITIVELY TILTED AND WILL ACT
TO SHUNT/SHEAR OUT THE WAVE TO OUR SOUTH. REASONABLE AGREEMENT WITH
SUFFICIENT MOISTURE TRANSPORT SNEAKING ACROSS THE MICHIGAN BORDER TO
SUPPORT SOME LIGHT SNOW...AS 850-700 MB SPECIFIC HUMIDITY OF 3+ G/KG
SEEN REACHING THE M-59 CORRIDOR (REGIONAL GEM/GFS) OR EVEN AS FAR
NORTH AS THE I-69 CORRIDOR (NAM). THERMAL PROFILES ARE NOT IDEAL FOR
HIGH SNOW TO LIQUID RATIOS HOWEVER. FORCING FROM ISENTROPIC ASCENT
PROSPECTIVE IS NOT VERY AGGRESSIVE...AND BEST 850 MB FGEN LOOKS TO
BE OCCURRING AT OR JUST SOUTH OF THE MICHIGAN BORDER. NOT MUCH OF A
SURFACE REFLECTION AS WELL. THIS APPEARS TO BE A 1 TO 2 INCH
SNOWFALL FOR MOST OF SOUTHEAST MICHIGAN (FOCUSED M-59 SOUTH) BY THE
TIME THE SNOW ENDS MONDAY MORNING. 925 MB TEMPS PROGGED TO RISE TO
AROUND -5 C...BUT BOUNDARY LAYER DEPTH WILL FAIL TO REACH THIS
LEVEL...AND A SLOW GRIND INTO THE 20S FOR HIGHS EXPECTED
TOMORROW...WITH TEMPS HOLDING NEARLY STEADY SUNDAY EVENING/NIGHT
WITH THE INCREASE IN MOISTURE AND SNOW. SURPRISINGLY...NORTHERN
STREAM TROUGH LOOKS TO BE PROVIDING ONLY A GLANCING BLOW WITH THE
COLD AIR...AS 850 MB TEMPS PROGGED TO DROP INTO MID NEGATIVE TEENS
(PER 12Z EURO)...WITH DRY AIR/SUBSIDENCE WINNING OUT AT THIS
LEVEL...WITH RH DROPPING BELOW 50 PERCENT. STILL...WITH LONG FETCH
NORTHERLY FLOW DEVELOPING OVER LAKE HURON ON MONDAY...ENOUGH COLD
AIR/INSTABILITY/SATURATION AT THE 925 MB LEVEL TO GENERATE SOME SNOW
SHOWERS...PROBABLY BRUSHING THE LAKE HURON SHORELINE...BUT THE
SHALLOW NATURE IS EXPECTED TO LIMIT THE INTENSITY. LOW LEVEL WINDS
EVEN BECOME LIGHT NORTHEAST/ONSHORE BY MONDAY EVENING...BUT AGAIN
WITH THE AMOUNT OF DRY AIR AROUND AND SHALLOW NATURE...SHOULD LIMIT
ACTIVITY TO SCATTERED LIGHT SNOW SHOWERS...WITH JUST LIGHT
ACCUMULATIONS EXPECTED OVER THE NORTHERN THUMB REGION.
SPLIT FLOW ALOFT AND STABLE COLD ANTICYCLONE AT THE SURFACE WILL
LEAD TO COLD AND DRY WEATHER TUESDAY AND WEDNESDAY. WITH SNOW PACK
AND LIGHT WINDS WE COULD SEE TEMPS TANK PRETTY WELL TUESDAY NIGHT
PROVIDED ENOUGH CLEARING TAKES PLACE. THE COLD AIRMASS BEGINS TO
SCOUR OUT A BIT THURSDAY AS SURFACE PRESSURE GRADIENT TIGHTENS AHEAD
OF INCOMING UPPER TROUGH. FRONTAL PASSAGE LATE THURSDAY COULD LEAD
TO A FEW LIGHT SNOW SHOWERS...BUT IT WILL BE MOISTURE STARVED SO
WILL KEEP POPS OUT FOR NOW. PROGRESSIVE NATURE OF THE TROUGH WILL
ALLOW RISING HEIGHTS AND WARM AIR ADVECTION FRIDAY WITH TEMPERATURES
POSSIBLY FINALLY APPROACHING NORMAL BY NEXT WEEKEND.
MARINE...
COLD SOUTHWEST FLOW OVER THE CENTRAL GREAT LAKES THIS AFTERNOON
LEADING TO SUSTAINED WINDS OF 20 TO 30 KNOTS OVER LAKE HURON AS THE
AREA IS SANDWICHED IN BETWEEN LOW PRESSURE OVER ONTARIO AND HIGH
PRESSURE ALONG THE OHIO RIVER. A MARGINAL GUST TO GALES REMAIN
POSSIBLE FOR ANOTHER FEW HOURS AND WILL EXTEND HEAVY FREEZING
WARNING INTO THE EVENING...BUT THE HIGH WILL BE SLOWING EXITING
EAST...ALLOWING THE PRESSURE GRADIENT TO RELAX AS WE HEAD INTO
TONIGHT AND ESPECIALLY TOMORROW...AS ANOTHER ARCTIC COLD FRONT
APPROACHES. THIS FRONT WILL SLIDE THROUGH TOMORROW NIGHT INTO
MONDAY...LEADING TO NORTHERLY WINDS OVER LAKE HURON. THE ARCTIC AIR
IN THE WAKE OF THIS FRONT WILL BE MORE SHALLOW...THUS REDUCING
MIXING DEPTHS...WITH GUSTS ONLY UP TO 30 KNOTS EXPECTED DURING
MONDAY. WINDS WILL DECREASE RAPIDLY MONDAY EVENING/NIGHT AS STRONG
HIGH PRESSURE SETTLES OVER THE ENTIRE GREAT LAKES REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
SHORT TERM...MR
LONG TERM....SF/DT
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1137 PM EST SAT JAN 10 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 320 PM EST SAT JAN 10 2015
A SLIGHT WARM UP IS ON THE WAY FOR THIS COMING WEEK. AS THE WARM
AIR STARTS TO MOVE IN TONIGHT THERE WILL BE A PERIOD OF LIGHT SNOW
SHOWERS...MOSTLY NORTH AND WEST OF GRAND RAPIDS. ANOTHER PERIOD OF
LIGHT SNOW WILL CROSS AREAS NEAR AND SOUTH OF INTERSTATE 96 SUNDAY
NIGHT AS THE COLD AIR ONCE AGAIN TRIES TO PUSH BACK SOUTHWARD. AS
OUR LAST POLAR ORIGIN HIGH OF THIS CURRENT WEATHER PATTERN MOVES
IN MONDAY SKIES WILL BE MOSTLY CLOUDY BUT WILL SEE CLEARING LATE
IN THE DAY. WITH THE HIGH OVERHEAD ON TUESDAY EXPECT MOSTLY SUNNY
SKIES AND VERY COLD TEMPERATURES FOR ONE MORE DAY. LOW WILL BE BELOW
ZERO IN MOST AREAS THAT NIGHT. BEY0ND THAT A SLOW WARM UP BEGINS. BY
NEXT SATURDAY WE MAY HAVE HIGH ABOVE FREEZING.
&&
.UPDATE...
ISSUED AT 951 PM EST SAT JAN 10 2015
WILL REDUCE POPS TO CHANCE OR SLIGHT CHANCE EVERYWHERE OVERNIGHT. A
LOT OF SHEAR IS SHOWING UP IN THE PROFILES WHICH IS REDUCING THE
LAKE ENHANCEMENT. ANY SNOW SHOULD REMAIN WITH LESS THAN AN INCH OF
ACCUMULATION POSSIBLE OVER PARTS OF THE NW CWA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 320 PM EST SAT JAN 10 2015
WE HAVE THE DEPARTING OF THE WEEK LONG COLD PATTERN UNDERWAY AS I
WRITE THIS. THIS WAS THE LONGEST STRING OF DAYS IN A ROW WITH
HIGHS BELOW 20 DEGREES IN GRAND RAPIDS SINCE THE MIDDLE OF
FEBRUARY IN 2007. THIS WILL BE HISTORY ON SUNDAY.
AS THE WARM AIR SURGES IN TONIGHT... EVEN WITH VERY FEEBLE
MOISTURE (PRECIPITABLE WATER SURGES TO A THIRD OF AN INCH/ 75TH
PERCENTILE)...SOME LIGHT SNOW IS EXPECTED WEST OF US-131 AND NORTH
OF GRAND RAPIDS DURING THE EARLY TO MID EVENING. THIS IS SHOWN BY
THE NAM... GFS... ECMWF... HRRR AND RAP MODELS TO VARYING DEGREES.
THERE IS A SURFACE BASED THERMAL BOUNDARY (20 DEGREE HOLLAND / 12AT
GRAND RAPIDS) CURRENTLY LOCATED FROM SOUTH HAVEN TO NEAR GRAND
RAPIDS TO NEAR MOUNT PLEASANT. THIS IS CURRENTLY FOCUSING SNOW
SHOWERS NEAR THE LAKE SHORE AND HELP FOCUS THE SNOW SHOWERS WITH
WARM AIR PUSH TONIGHT. ALSO HELPING THIS EVENT TOO IS THE LIFT
ASSOCIATED WITH THE ENTRANCE REGION TO DEPARTING UPPER LEVEL JET
CORE. THERE IS A 3 HOUR WINDOW WHERE OUR NORTHWEST CWA WILL HAVE
SOLID NEAR SATURATED AIR FROM AROUND 1000 FT AGL TO NEAR 10,000 FT
AGL. GIVEN HOW COLD IT IS...THAT IS MORE THAN ENOUGH TO LEAD TO
LIGHT SNOW SHOWERS.
ONCE THAT IS DONE SUNDAY NIGHT WE GET THE INTERPLAY OF THAT SAME
JET EXIT REGION WITH EXIT REGION OF JET CORE LIFTING NORTHWARD
FROM A SOUTHERN STREAM WAVE. THIS RESULTS IN A COUPLED JET AND THE
PRECIPITABLE WATER SURGES EVEN HIGHER TO NEARLY A HALF INCH WITH IS
ABOUT DOUBLE NORMAL. SO I AM THINKING LIGHT SNOW IS MORE THAN
LIKELY SOUTH OF INTERSTATE 96 SUNDAY NIGHT. IT IS MY EXPERIENCE
THAT THIS SORT OF EVENT NEARLY ALWAYS RESULTS IN MEASURABLE
PRECIPITATION SO I HAVE HIGH CONFIDENCE THERE WILL BE LIGHT SNOW
ALONG THE I-94 CORRIDOR SUNDAY NIGHT.
ONCE THAT IS DONE A JET CORE ON THE NORTHERN STREAM...DIVING DUE
SOUTHEAST FROM THE NORTHERN ARCTIC TOWARD HUDSON BY TUESDAY BRINGS
US OUR LAST SURGE OF VERY COLD AIR FOR TUESDAY. SINCE THE JET CORE
THIS TIME WILL BE WELL NORTH OF MICHIGAN THIS WILL BE SHALLOW COLD
AIR AND WINDS AT THE SURFACE WILL BE NORTHEAST SO WE GET TO SEE
MOSTLY SUNNY SKIES FOR A CHANGE! EVEN SO WITH SNOW ON THE GROUND
OVER MOST OF THE AREA IT WILL BE VERY COLD ONE LAST DAY.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 320 PM EST SAT JAN 10 2015
THE LONG TERM PORTION OF THE FCST LOOKS TO BE VERY QUIET FOR THIS
TIME OF THE YEAR. WE WILL START OFF WITH A COLD MORNING AT THE
BEGINNING OF THE PERIOD...AND THEN MODERATE AT THE END OF THE PERIOD.
WE WILL SEE A VERY COLD MORNING TUE MORNING AND AGAIN ON TUE
NIGHT/WED MORNING. HIGH PRESSURE PROVIDING A LIGHT GRADIENT AND
MAINLY CLEAR SKIES...WILL COMBINE WITH OUR SNOW PACK TO ALLOW MOST
TEMPS TO DROP BELOW ZERO TUE MORNING AND WED MORNING.
SOME MODERATION IN TEMPS WILL TAKE PLACE FOR WED AND THU AS RETURN
FLOW FROM THE WSW WILL SET UP OVER THE AREA. HIGH PRESSURE WILL DROP
SOUTH...AND WE WILL EVENTUALLY SEE A COLD FRONT TRY TO APPROACH THE
AREA FROM THE NW. TOUGH TO TELL HOW FAR SOUTH THIS FRONT WILL MAKE
IT...BUT IT COULD BRING A LOW CHC OF SNOW TO THE NRN PORTION OF THE
AREA ON THU. THE FRONTAL POSITION WILL ALSO DICTATE HOW WARM WE GET.
THE GFS TAKES IT A BIT FURTHER SOUTH WHILE THE EURO HOLDS IT UP
NORTH OF THE AREA.
THE BEST MODERATION IN TEMPS WILL COME AT THE END OF THE PERIOD.
AFTER THE THU SYSTEM MOVES BY...WE WILL GET BACK INTO A RETURN FLOW
PATTERN ONCE AGAIN. A ZONAL FLOW ALOFT WILL KEEP THE COLD AIR AND
WAVES OF LOW PRESSURE FAR ENOUGH NORTH TO KEEP OUR AREA DRY. WE
SHOULD SEE TEMPS AT LEAST GET INTO THE 30S BY NEXT SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1137 PM EST SAT JAN 10 2015
VFR CONDITIONS SHOULD PREVAIL THROUGH SUNDAY ALTHOUGH THERE WILL
BE AREAS OF LIGHT SNOW AND CEILINGS IN THE 2500 TO 3000 FOOT
RANGE AT MKG AT TIMES TONIGHT. SOUTHWEST WINDS AROUND 10 KNOTS
THROUGH SUNDAY WITH SOME GUSTS OVER 20 KNOTS TONIGHT AT MKG.
&&
.MARINE...
ISSUED AT 320 PM EST SAT JAN 10 2015
I WILL ALLOW THE FREEZING SPRAY WARNING TO CONTINUE THROUGH 7 PM
AS WINDS ARE NEAR 25 KNOTS OVER THE WATER AND TEMPERATURES WERE IN
THE TEENS. SEEMS THAT TEMPERATURES WILL RISE INTO THE 20S IN THE
NEAR SHORE THIS EVENING ALLOWING US TO LET THE WARNING EXPIRE ON
TIME. WINDS WILL REMAIN STRONG ENOUGH FOR SMALL CRAFT INTO SUNDAY.
WE WILL HAVE TO WATCH TO SEE HOW MUCH THE ICE GROWS. THANKS TO
GLERL WE KNOW THERE IS ABOUT 22% ICE COVERAGE ON LAKE MICHIGAN NOW
AND THAT IF FORECAST TO INCREASE INTO THE MIDDLE OF NEXT WEEK.
&&
.HYDROLOGY...
ISSUED AT 320 PM EST SAT JAN 10 2015
LITTLE CHANGE SINCE YESTERDAY. CONTINUED THE FLOOD ADVISORY FOR THE
FLAT RIVER NEAR SMYRNA AS IT SHOULD REMAIN ABOVE BANKFULL INTO NEXT
WEEK. A COUPLE RIVERS REMAIN NEAR BUT UNDER BANKFULL AND WILL HAVE
TO BE MONITORED. FREEZE UP ICE JAMS MAY CAUSE FLUCTUATIONS IN RIVER
LEVELS INTO NEXT WEEK... BUT SERIOUS FLOODING IS NOT MUCH OF A
CONCERN UNTIL SNOWMELT AND ICE BREAKUP HAPPENS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...JK
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1156 PM CST Sat Jan 10 2015
.UPDATE:
Issued at 916 PM CST Sat Jan 10 2015
Temperatures have been slow to drop this evening due to southerly
winds and mid level clouds advecting northeastward through much of
the area, particularly southeast MO into southwest IL. The
operational models keep the precipitation out of our forecast area
until after 12Z Sunday. The latest HRRR model does bring some
light precipitation into our area already between 10-12Z Sunday,
but this is likely too early with an initially dry surface and
boundary layer. The precipitation may begin as sleet due to
evaporative cooling with very low surface dew points, but should
transition to freezing rain later in the morning with a pronounced
elevated warm layer.
GKS
&&
.SHORT TERM: (Through Late Tonight)
Issued at 333 PM CST Sat Jan 10 2015
The latest data suggests that the weather tonight should be rather
tranquil but seasonably cold. Heights aloft will be on the rise as
the eastern U.S. trof departs and short wave ridging increases ahead
of the lifting west TX upper low trof. In response the gradual
backing of the mid/upper level flow will allow clouds/moisture to
beginning spread into the area, especially overnight.
Glass
.LONG TERM: (Sunday through Next Saturday)
Issued at 333 PM CST Sat Jan 10 2015
Present indications are the winter weather event still remains on
track Sunday into Sunday night. Although the aforementioned
lifting upper low/trof will be weakening, it will spread weak
large scale ascent across the area Sunday into early Sunday
evening. This combined with ascent via low level warm advection
will allow precipitation to spread and develop northward from the
lower MS Valley into Missouri on Sunday morning. The primary
thrust will be across the southeast third of the CWA -
southeast/east central MO into southern IL. I am anticipating the
bulk of the precipitation to be in liquid form aka freezing rain.
Model soundings in this region show a deepening and strengthening
elevated warm layer, thus any sleet should occur in a small window
near the onset of the precipitation. Surface temperatures during
the day on Sunday will actually be warming in response to the low
level warm advection and will hover near freezing by mid-late
afternoon, however the speed at which this warming proceeds may be
hampered some by diabatic effects. Ground temperatures from the
recent Arctic blasts remain quite cold adding to the ice accretion
potential. Further north the precipitation coverage on Sunday as
well as the actual threat remains much more in question and pops
are only in the chance range. The elevated warm layer further
north is much weaker as well, allowing for a greater threat of
sleet should precipitation occur. Some of the guidance actually
suggests a narrow west-east warm advection band could quickly lift
northward across the northern half of the CWA but confidence at
this point is low.
The forecast for Sunday night is hardly clear cut. I think the main
thrust of warm advection precipitation will have exited the CWA to
the east or be close to exiting at 00Z Monday. However weak warm
advection will persist in the evening and a weak trailing vort max
will track across the area. We could see a band of light snow across
northern MO into central IL in association with ascent with the vort
max and mid level convergence/frontogenesis, while further south the
warm advection may contribute to very light freezing rain or freezing
drizzle.
Cumulatively this looks like a light event, with ice amounts of a
tenth of an inch or less in the most threatened region of southeast
and east central MO into southern IL. A winter weather advisory
has been hoisted in this area with the main impact being on travel
from ice accumulation on untreated roadways.
Clouds and cold advection dominate on Monday with a chance of snow
in the morning. The clouds should slowly clear north-south during
the day. Arctic high pressure but not as formidable as recent
systems will dominate the region Tuesday into Wednesday. A
progressive upper trof will move through the lower/mid MS Valley
late Wednesday with any precipitation threat looking to be to the
south of us at this time. In the wake of this trof the flow aloft
flattens and heights rise, leading to moderating temperatures the
later half of the week and into next Saturday.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1114 PM CST Sat Jan 10 2015
Complex fcst beyond 18Z Sunday. Prior to that expect a VFR
overcast with sthrly winds. Mdls indicate a narrow band of precip
lifting north thru MO and the sthrn half of IL Sunday mrng. Low
lvls remain rather dry so not sure any of this will reach the
ground and have not included this in the TAFs attm. Two areas of
precip dvlp/move into the region from late mrng thru the aftn. The
first area of precip will move into sthrn MO late mrng and then
on into e cntrl MO and sthrn IL drng the aftn. The STL metro sites
should be on the NW fringe of this area of precip. P-types will
also be a challenge as sfc temps are expected to hover near
freezing thru the day and a degree or two in either direction has
a significant effect on impacts. Have kept -FZRA going even though
fcst high temps are 32-34 degrees based on very cold grounds temps
due to recent cold temps. Bulk of the precip should exit east drng
the evng with -FZDZ remaining the rest of the night as addntl
upper lvl energy passes thru the region. The second batch of precip
is fcst to dvlp across nthrn MO ENE into SE IA and nthrn IL drng
the aftn. KUIN appears to be on the sthrn edge of this precip.
Soundings indicate colder conditions aloft further north so went
with a SN/PL mix though can`t rule out -FZRA/FZDZ mixing in drng
the aftn. This precip is fcst to continue into the overnight hrs and
should gradually transition to all snow after 6Z. KCOU may end up
too far west to be impacted by the larger area of precip to affect
the STL metro area and too far south to get in on the band of
sleet and snow to affect KUIN. If precip does occur at KCOU, it is
likely to be -RA/DZ drng the day as sfc temps are fcst to rise
into the mid 30s switching to -FZDZ drng the evng as sfc temps cool.
Have a low end MVFR CIG/VSBY fcst going Sunday night but fully
expect both elements to be IFR at some point drng the night.
Specifics for KSTL:
VFR conditions expected thru 18Z. Precip is expected to move into
the terminal drng the aftn with sfc temps near 32. Have -FZRA in
the TAF due to cold ground temps. If temps rise above 32 then
elevated sfcs will not experiencing icing effects. Bulk of the
precip moves out of the terminal drng the evng bcmng -FZDZ as air
temps drop below freezing. -FZDZ is expected to continue thru the
night possibly ending as a bit of light snow or flurries. Have a
low end MVFR fcst going but fully expect both IFR CIGs/VSBYs
Sunday night.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER WEATHER ADVISORY from 8 AM Sunday to 6 AM CST Monday FOR
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Lincoln MO-Madison MO-Osage MO-Reynolds MO-St. Charles MO-
St. Francois MO-St. Louis City MO-St. Louis MO-Ste.
Genevieve MO-Warren MO-Washington MO.
IL...WINTER WEATHER ADVISORY from 8 AM Sunday to 6 AM CST Monday FOR
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey
IL-Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
Randolph IL-St. Clair IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1208 PM CST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1207 PM CST SUN JAN 11 2015
LETS ADMIT IT: OVERALL TODAY IS TURNING OUT TO BE A SOMEWHAT
NICER DAY THAN ANTICIPATED 24 HOURS AGO...WITH MOSTLY SUNNY SKIES
AND LARGELY AS A RESULT...WARMER TEMPERATURES. HAVE TO GIVE A BIG
KUDOS TO NIGHT SHIFT FORECASTER WHO CRANKED UP HIGH TEMPS 7-9
DEGREES FROM PREVIOUS FORECAST. ALTHOUGH THIS MAY END UP BEING A
TOUCH TOO WARM IN A FEW SPOTS...BASED ON TRENDS SO FAR TODAY OPTED
TO MAKE NO CHANGE WHATSOEVER AND LET THESE HIGHS RIDE...WHICH
RANGE FROM UPPER 20S NORTH...NEAR-30 TRI-CITIES AND LOW 40S NEAR
AND SOUTH OF THE STATE LINE. AM KEEPING A CLOSE EYE ON AN
EXPANSIVE DECK OF LOWER STRATUS OVER SOUTHERN KS THAT IS SLOWLY-
BUT-SURELY PUSHING NORTH-NORTHEAST...BUT SHORT TERM MODELS SUCH AS
THE RAP13/HRRR BARELY BRUSH THIS LOWER CLOUD DECK INTO THE FAR
SOUTH/SOUTHEASTERN CWA IN KS ZONES...IF EVEN AT ALL LATER
TODAY/THIS EVENING. EVENTUALLY THIS AFTERNOON...A SOMEWHAT
STEADIER NORTH BREEZE WILL FINALLY BECOME ESTABLISHED AS MODEST
PRESSURE RISES MOVE SOUTHWARD INTO THE AREA FROM THE EXPANSIVE
SURFACE HIGH CURRENTLY CENTERED FROM NORTHEAST MONTANA NORTHWARD.
LEGIT LOW LEVEL COLD AIR ADVECTION DOES NOT REALLY KICK IN THOUGH
UNTIL VERY LATE THIS AFTERNOON/THIS EVENING...
NO FORECAST CHANGES POSTED YET BEYOND 00Z/6PM THIS EVENING...
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 253 AM CST SUN JAN 11 2015
THE FOCUS DURING THE SHORT TERM PERIODS WILL AGAIN BE CENTERED
AROUND CLOUDS AND TEMPERATURES. THE PATTERN ALOFT FEATURED
WESTERLY FLOW ACROSS OUR REGION WITH EMBEDDED WAVES IN THE FLOW.
ONE SUCH WAVE WAS TRANSLATING ACROSS KS...WHICH WILL HAVE LITTLE
CONSEQUENCE FOR OUR AREA. FARTHER NORTH ENERGY MOVING SOUTH FM
CANADA WAS MOVING SOUTH INTO THE NORTHERN PLAINS AND THIS WILL
SEND A REINFORCING COLD FRONT ACROSS THE PLAINS LATE THIS AFTN AND
TONIGHT.
CURRENT CONDITIONS AS OF 08Z PLACED A COOL FRONTAL BOUNDARY JUST
SOUTH OF THE PLATTE RIVER. TEMPERATURES BEHIND THE FRONT AVERAGED IN
THE SINGLE DIGITS AND TEENS WHILE AHEAD OF THE BOUNDARY READINGS
AVERAGED IN THE MIDDLE 20S. SO FAR FOG HAS YET TO FORM AND IF TRENDS
CONTINUE WILL REMOVE MENTION FOR THE EARLY MORNING HOURS.
WITH NO REAL PUSH OF THE FRONT TODAY...THE BOUNDARY IS ONLY EXPECTED
TO GRADUALLY SAG SOUTH INTO OUR SOUTHERN ZONES LATE THIS AFTN OR
EARLY EVENING. AHEAD OF THE FRONT TEMPS COULD EASILY BE QUITE
MILD IN THE 40S ACROSS MUCH OF KS...SIMILAR TO RAP DEPICTION BUT
THIS WILL ALSO BE DEPENDENT UPON CLOUD COVER. THE NAM IS ALSO ROBUST
WITH LLVL MOISTURE AND LOW CLOUDS LIFTING NORTH AHEAD OF THE
APPROACHING SHORTWAVE AND SURGES MOISTURE NORTH OF THE FRONT. THE
GFS KEEPS THE BRUNT OF THE CLOUDS SOUTH OF THE BOUNDARY. THE NAM
IS STILL SUFFERING FROM OVERZEALOUS SNOWPACK INITIALIZATION AND
LLVL MOISTURE FIELDS LIKELY DUE TO POTENTIAL SNOW MELT AND HAD TO
SHY AWAY FROM IT FOR THIS FORECAST. FOR THE FORECAST TODAY...HAVE
WENT WITH VARYING CLOUD COVER THRU THE FIRST PART OF THE AFTN WITH
TEMPS SIMILAR TO RAP WITH READINGS RANGING FROM THE UPPER 20S IN
OUR NORTHERN CWA (NORTH OF FRONT) TO TEMPS IN THE 40S ACROSS MUCH
OF NORTH CENTRAL KS (SOUTH OF BOUNDARY). CLOUD COVER WILL INCREASE
AND TEMPS COOL N/S WITH ARRIVAL OF SECONDARY COLD FRONT LATER THIS
AFTN AND TONIGHT.
CLOUD COVER WITH FRONT/WAVE WILL BE AT MID/HIGH LEVELS SO NOT
LOOKING FOR PCPN WITH THE SECONDARY COLD FRONT THIS EVENING/TONIGHT.
COLDER CONDITIONS WILL SETTLE IN DURING THE NIGHT AS A 1045 MB
SURFACE HIGH BUILDS SOUTH FM THE DAKOTAS. THE AIRMASS CHANGE IS A
DROP OF NEARLY 10C AT H85 FROM THIS MORNING TO MONDAY MORNING.
OVERNIGHT LOWS PRIMARILY IN THE SINGLE DIGITS COMBINED WITH A STEADY
NORTH WIND WILL PRODUCE WIND CHILLS BELOW ZERO BUT VALUES ARE NOT
LOOKING QUITE COLD ENOUGH FOR AN HWO MENTION ATTM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 253 AM CST SUN JAN 11 2015
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM LIE WITH
TEMPERATURES AND EARLY WEEK PRECIPITATION CHANCES.
MONDAY STILL ON TRACK TO BE THE COLDEST DAY OF THE FORECAST
PERIOD...WITH MODELS IN GOOD AGREEMENT SHOWING THE CWA BEING ON THE
SOUTHERN END OF AN UPPER LEVEL TROUGH AXIS EXTENDING BACK UP INTO
THE HUDSON BAY AREA. THIS TROUGH CONTINUES TO SWING THROUGH/EAST OF
THE CWA DURING THE DAYTIME HOURS MONDAY...WITH ZONAL TO SLIGHT NWRLY
FLOW BUILDING IN BEHIND. EVEN WITH THIS TROUGH SWINGING
THROUGH...MODELS NOT SHOWING AN ABUNDANCE OF MOISTURE AND CONTINUE
TO KEEP CONDITIONS DRY. THIS SYSTEM BRINGS A REINFORCING SHOT OF
NRLY WINDS AND COLDER AIR...SPEEDS ARE ONLY TOPPING OUT AROUND 10 TO
15 MPH IN THE MORNING...BUT WILL DIMINISH WITH TIME AS SFC HIGH
PRESSURE SETTLES FURTHER SOUTH. THE CENTER OF THE SFC HIGH REMAINS
OFF TO THE N/NE OF THE CWA...ENDING UP OVER FAR NERN NEB AT
00Z...THEN SHIFTS OVER TO THE CENTRAL PORTIONS OF THE IA/MN BORDER
BY TUESDAY MORNING...WHICH WILL BRING A GRADUAL TRANSITION IN WINDS
TO THE EAST THAN MORE SOUTHERLY BY 12Z TUESDAY. DID NOT MAKE NOTABLE
CHANGES TO INHERITED HIGHS FOR MONDAY...WHICH RANGE FROM THE LOWER
TEENS IN THE FAR NORTH TO LOWER 20S ACROSS NC KS. OVERNIGHT LOWS
MONDAY NIGHT/TUESDAY MORNING LOOK TO BOTTOM OUT IN THE SINGLE DIGITS
BELOW ZERO IN THE NORTHEAST TO NEAR 10 DEGREES IN THE FAR SW.
TUESDAY/TUESDAY NIGHT...MAIN STORY LIES WITH AN UPPER LEVEL
DISTURBANCE WHICH BY SUNRISE TUESDAY HAS DUG SOUTH INTO THE CENTRAL
ROCKIES/4 CORNERS REGION...WITH ZONAL FLOW IN PLACE ACROSS OUR AREA.
THROUGH THE DAYTIME HOURS...MODELS IN DECENT AGREEMENT SHOWING A
CLOSED CIRCULATION DEVELOPING OVER THE 4 CORNERS REGION...AND
TREKKING MAINLY EAST INTO THE TUESDAY NIGHT PERIOD...BUT ALSO
FILLING WITH TIME. THE 00Z ECMWF/GFS/GEM ARE ALL IN PRETTY GOOD
AGREEMENT SHOWING THE BRUNT OF THIS SYSTEM SLIDING TO THE SOUTH OF
THE CWA...BARELY GETTING CLIPPED BY THE NRN EDGE OF
PRECIPITATION...IF AT ALL. DISCOUNTED THE 00Z NAM...WHICH WAS
NOTABLY FURTHER NORTH AND DEEPER WITH THE SYSTEM...AND SHOWED SOME
LOCATIONS GETTING UPWARDS OF 4 INCHES OF SNOW. THE 06Z RUN HAS COME
MORE IN LINE WITH THE ECMWF/GFS/GEM. CONTINUED TO KEEP SOME 30-40
POPS CONFINED TO THE FAR S/SWRN PORTIONS OF THE CWA...WITH SOME 20
POPS BUFFERING THAT AREA TO THE NORTH. AT THIS POINT...IF SNOW DOES
MAKE IT FAR ENOUGH NORTH TO AFFECT OUR CWA...NOT EXPECTING MUCH IN
THE WAY OF ACCUMULATION. EXPECTING A BUMP UP IN TEMPS...WITH HIGHS
CURRENTLY FORECAST TO REACH THE LOWER 20S.
THROUGH THE REMAINDER OF THE LONG TERM PERIOD...WEDNESDAY THROUGH
SATURDAY...THE FORECAST CONTINUES TO BE A DRY ONE...WITH MODELS IN
DECENT AGREEMENT SHOWING NORTHWESTERLY FLOW DEVELOPING FOR WED/THURS
THANKS TO AT LEAST BRIEF RIDGING OVER THE WRN CONUS...BEFORE
BECOMING MORE ZONAL INTO FRI/SAT WITH AN APPROACHING DISTURBANCE
FROM THE NW. EXPECTING MODERATING TEMPERATURES ALOFT TO WORK THEIR
WAY IN FROM THE WEST...AND ALONG WITH THE POTENTIAL FOR MORE
DOWNSLOPING WRLY WINDS ESP THURS/FRI...TEMPS CLIMB A BIT EACH
DAY...AND ARE FORECAST BACK IN THE LOW/MID 40S CWA-WIDE FOR FRIDAY.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1207 PM CST SUN JAN 11 2015
CONFIDENCE IS QUITE HIGH IN PRECIPITATION-FREE WEATHER AND VFR
VISIBILITY THROUGH THE NEXT 24 HOURS...WHILE CONFIDENCE IS
REASONABLY HIGH (BUT NOT AS HIGH) IN VFR CEILING LASTING
THROUGHOUT. SURFACE HIGH PRESSURE BUILDING SOUTHWARD FROM THE
NORTHERN PLAINS WILL ALLOW INITIALLY LIGHT EASTERLY BREEZES EARLY
THIS AFTERNOON TO BECOME BETTER ESTABLISHED FROM A NORTHERLY
DIRECTION LATER THIS AFTERNOON INTO THIS EVENING...WITH AT LEAST A
FEW HOURS OF GUST POTENTIAL TO AROUND 18KT. MAINLY DURING A 5-HOUR
WINDOW FROM 23Z-04Z...SOME MODELS SUGGEST THAT AT LEAST A BRIEF
MVFR CEILING COULD PASS THROUGH THE AREA...BUT GIVEN THE TRACK
RECORD OF SOME MODELS/GUIDANCE THE PAST 24 HOURS ALONG WITH ALMOST
NO UPSTREAM EVIDENCE OF THIS...HAVE KEPT THE TAFS VFR FOR NOW BUT
WHILE HINTING AT THE MVFR POSSIBILITY WITH A "SCT010" MENTION.
BREEZES WILL REMAIN NORTHERLY THROUGH THE NIGHT AND INTO MONDAY
MORNING...BUT WITH A SUBTLE DECREASE IN SPEEDS AS THE HIGH
PRESSURE CENTER EDGES CLOSER.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...FAY
LONG TERM...ADP
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
520 AM CST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 253 AM CST SUN JAN 11 2015
THE FOCUS DURING THE SHORT TERM PERIODS WILL AGAIN BE CENTERED
AROUND CLOUDS AND TEMPERATURES. THE PATTERN ALOFT FEATURED
WESTERLY FLOW ACROSS OUR REGION WITH EMBEDDED WAVES IN THE FLOW.
ONE SUCH WAVE WAS TRANSLATING ACROSS KS...WHICH WILL HAVE LITTLE
CONSEQUENCE FOR OUR AREA. FARTHER NORTH ENERGY MOVING SOUTH FM
CANADA WAS MOVING SOUTH INTO THE NORTHERN PLAINS AND THIS WILL
SEND A REINFORCING COLD FRONT ACROSS THE PLAINS LATE THIS AFTN AND
TONIGHT.
CURRENT CONDITIONS AS OF 08Z PLACED A COOL FRONTAL BOUNDARY JUST
SOUTH OF THE PLATTE RIVER. TEMPERATURES BEHIND THE FRONT AVERAGED IN
THE SINGLE DIGITS AND TEENS WHILE AHEAD OF THE BOUNDARY READINGS
AVERAGED IN THE MIDDLE 20S. SO FAR FOG HAS YET TO FORM AND IF TRENDS
CONTINUE WILL REMOVE MENTION FOR THE EARLY MORNING HOURS.
WITH NO REAL PUSH OF THE FRONT TODAY...THE BOUNDARY IS ONLY EXPECTED
TO GRADUALLY SAG SOUTH INTO OUR SOUTHERN ZONES LATE THIS AFTN OR
EARLY EVENING. AHEAD OF THE FRONT TEMPS COULD EASILY BE QUITE
MILD IN THE 40S ACROSS MUCH OF KS...SIMILAR TO RAP DEPICTION BUT
THIS WILL ALSO BE DEPENDENT UPON CLOUD COVER. THE NAM IS ALSO ROBUST
WITH LLVL MOISTURE AND LOW CLOUDS LIFTING NORTH AHEAD OF THE
APPROACHING SHORTWAVE AND SURGES MOISTURE NORTH OF THE FRONT. THE
GFS KEEPS THE BRUNT OF THE CLOUDS SOUTH OF THE BOUNDARY. THE NAM
IS STILL SUFFERING FROM OVERZEALOUS SNOWPACK INITIALIZATION AND
LLVL MOISTURE FIELDS LIKELY DUE TO POTENTIAL SNOW MELT AND HAD TO
SHY AWAY FROM IT FOR THIS FORECAST. FOR THE FORECAST TODAY...HAVE
WENT WITH VARYING CLOUD COVER THRU THE FIRST PART OF THE AFTN WITH
TEMPS SIMILAR TO RAP WITH READINGS RANGING FROM THE UPPER 20S IN
OUR NORTHERN CWA (NORTH OF FRONT) TO TEMPS IN THE 40S ACROSS MUCH
OF NORTH CENTRAL KS (SOUTH OF BOUNDARY). CLOUD COVER WILL INCREASE
AND TEMPS COOL N/S WITH ARRIVAL OF SECONDARY COLD FRONT LATER THIS
AFTN AND TONIGHT.
CLOUD COVER WITH FRONT/WAVE WILL BE AT MID/HIGH LEVELS SO NOT
LOOKING FOR PCPN WITH THE SECONDARY COLD FRONT THIS EVENING/TONIGHT.
COLDER CONDITIONS WILL SETTLE IN DURING THE NIGHT AS A 1045 MB
SURFACE HIGH BUILDS SOUTH FM THE DAKOTAS. THE AIRMASS CHANGE IS A
DROP OF NEARLY 10C AT H85 FROM THIS MORNING TO MONDAY MORNING.
OVERNIGHT LOWS PRIMARILY IN THE SINGLE DIGITS COMBINED WITH A STEADY
NORTH WIND WILL PRODUCE WIND CHILLS BELOW ZERO BUT VALUES ARE NOT
LOOKING QUITE COLD ENOUGH FOR AN HWO MENTION ATTM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 253 AM CST SUN JAN 11 2015
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM LIE WITH
TEMPERATURES AND EARLY WEEK PRECIPITATION CHANCES.
MONDAY STILL ON TRACK TO BE THE COLDEST DAY OF THE FORECAST
PERIOD...WITH MODELS IN GOOD AGREEMENT SHOWING THE CWA BEING ON THE
SOUTHERN END OF AN UPPER LEVEL TROUGH AXIS EXTENDING BACK UP INTO
THE HUDSON BAY AREA. THIS TROUGH CONTINUES TO SWING THROUGH/EAST OF
THE CWA DURING THE DAYTIME HOURS MONDAY...WITH ZONAL TO SLIGHT NWRLY
FLOW BUILDING IN BEHIND. EVEN WITH THIS TROUGH SWINGING
THROUGH...MODELS NOT SHOWING AN ABUNDANCE OF MOISTURE AND CONTINUE
TO KEEP CONDITIONS DRY. THIS SYSTEM BRINGS A REINFORCING SHOT OF
NRLY WINDS AND COLDER AIR...SPEEDS ARE ONLY TOPPING OUT AROUND 10 TO
15 MPH IN THE MORNING...BUT WILL DIMINISH WITH TIME AS SFC HIGH
PRESSURE SETTLES FURTHER SOUTH. THE CENTER OF THE SFC HIGH REMAINS
OFF TO THE N/NE OF THE CWA...ENDING UP OVER FAR NERN NEB AT
00Z...THEN SHIFTS OVER TO THE CENTRAL PORTIONS OF THE IA/MN BORDER
BY TUESDAY MORNING...WHICH WILL BRING A GRADUAL TRANSITION IN WINDS
TO THE EAST THAN MORE SOUTHERLY BY 12Z TUESDAY. DID NOT MAKE NOTABLE
CHANGES TO INHERITED HIGHS FOR MONDAY...WHICH RANGE FROM THE LOWER
TEENS IN THE FAR NORTH TO LOWER 20S ACROSS NC KS. OVERNIGHT LOWS
MONDAY NIGHT/TUESDAY MORNING LOOK TO BOTTOM OUT IN THE SINGLE DIGITS
BELOW ZERO IN THE NORTHEAST TO NEAR 10 DEGREES IN THE FAR SW.
TUESDAY/TUESDAY NIGHT...MAIN STORY LIES WITH AN UPPER LEVEL
DISTURBANCE WHICH BY SUNRISE TUESDAY HAS DUG SOUTH INTO THE CENTRAL
ROCKIES/4 CORNERS REGION...WITH ZONAL FLOW IN PLACE ACROSS OUR AREA.
THROUGH THE DAYTIME HOURS...MODELS IN DECENT AGREEMENT SHOWING A
CLOSED CIRCULATION DEVELOPING OVER THE 4 CORNERS REGION...AND
TREKKING MAINLY EAST INTO THE TUESDAY NIGHT PERIOD...BUT ALSO
FILLING WITH TIME. THE 00Z ECMWF/GFS/GEM ARE ALL IN PRETTY GOOD
AGREEMENT SHOWING THE BRUNT OF THIS SYSTEM SLIDING TO THE SOUTH OF
THE CWA...BARELY GETTING CLIPPED BY THE NRN EDGE OF
PRECIPITATION...IF AT ALL. DISCOUNTED THE 00Z NAM...WHICH WAS
NOTABLY FURTHER NORTH AND DEEPER WITH THE SYSTEM...AND SHOWED SOME
LOCATIONS GETTING UPWARDS OF 4 INCHES OF SNOW. THE 06Z RUN HAS COME
MORE IN LINE WITH THE ECMWF/GFS/GEM. CONTINUED TO KEEP SOME 30-40
POPS CONFINED TO THE FAR S/SWRN PORTIONS OF THE CWA...WITH SOME 20
POPS BUFFERING THAT AREA TO THE NORTH. AT THIS POINT...IF SNOW DOES
MAKE IT FAR ENOUGH NORTH TO AFFECT OUR CWA...NOT EXPECTING MUCH IN
THE WAY OF ACCUMULATION. EXPECTING A BUMP UP IN TEMPS...WITH HIGHS
CURRENTLY FORECAST TO REACH THE LOWER 20S.
THROUGH THE REMAINDER OF THE LONG TERM PERIOD...WEDNESDAY THROUGH
SATURDAY...THE FORECAST CONTINUES TO BE A DRY ONE...WITH MODELS IN
DECENT AGREEMENT SHOWING NORTHWESTERLY FLOW DEVELOPING FOR WED/THURS
THANKS TO AT LEAST BRIEF RIDGING OVER THE WRN CONUS...BEFORE
BECOMING MORE ZONAL INTO FRI/SAT WITH AN APPROACHING DISTURBANCE
FROM THE NW. EXPECTING MODERATING TEMPERATURES ALOFT TO WORK THEIR
WAY IN FROM THE WEST...AND ALONG WITH THE POTENTIAL FOR MORE
DOWNSLOPING WRLY WINDS ESP THURS/FRI...TEMPS CLIMB A BIT EACH
DAY...AND ARE FORECAST BACK IN THE LOW/MID 40S CWA-WIDE FOR FRIDAY.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 518 AM CST SUN JAN 11 2015
VFR CONDITIONS ARE FORECAST THRU THE TAF PERIOD. CLOUD COVER IS
EXPECTED TO BE VARIABLE TODAY...BUT INCREASE/THICKEN BY LATE AFTN
INTO TONIGHT WITH THE PASSAGE OF A SECONDARY COLD FRONTAL
BOUNDARY. WINDS WILL REMAIN FROM A NORTHERLY DIRECTION AND WILL
INCREASE NEAR 15KTS BEHIND THE FRONT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...ADP
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
301 AM CST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 253 AM CST SUN JAN 11 2015
THE FOCUS DURING THE SHORT TERM PERIODS WILL AGAIN BE CENTERED
AROUND CLOUDS AND TEMPERATURES. THE PATTERN ALOFT FEATURED
WESTERLY FLOW ACROSS OUR REGION WITH EMBEDDED WAVES IN THE FLOW.
ONE SUCH WAVE WAS TRANSLATING ACROSS KS...WHICH WILL HAVE LITTLE
CONSEQUENCE FOR OUR AREA. FARTHER NORTH ENERGY MOVING SOUTH FM
CANADA WAS MOVING SOUTH INTO THE NORTHERN PLAINS AND THIS WILL
SEND A REINFORCING COLD FRONT ACROSS THE PLAINS LATE THIS AFTN AND
TONIGHT.
CURRENT CONDITIONS AS OF 08Z PLACED A COOL FRONTAL BOUNDARY JUST
SOUTH OF THE PLATTE RIVER. TEMPERATURES BEHIND THE FRONT AVERAGED IN
THE SINGLE DIGITS AND TEENS WHILE AHEAD OF THE BOUNDARY READINGS
AVERAGED IN THE MIDDLE 20S. SO FAR FOG HAS YET TO FORM AND IF TRENDS
CONTINUE WILL REMOVE MENTION FOR THE EARLY MORNING HOURS.
WITH NO REAL PUSH OF THE FRONT TODAY...THE BOUNDARY IS ONLY EXPECTED
TO GRADUALLY SAG SOUTH INTO OUR SOUTHERN ZONES LATE THIS AFTN OR
EARLY EVENING. AHEAD OF THE FRONT TEMPS COULD EASILY BE QUITE
MILD IN THE 40S ACROSS MUCH OF KS...SIMILAR TO RAP DEPICTION BUT
THIS WILL ALSO BE DEPENDENT UPON CLOUD COVER. THE NAM IS ALSO ROBUST
WITH LLVL MOISTURE AND LOW CLOUDS LIFTING NORTH AHEAD OF THE
APPROACHING SHORTWAVE AND SURGES MOISTURE NORTH OF THE FRONT. THE
GFS KEEPS THE BRUNT OF THE CLOUDS SOUTH OF THE BOUNDARY. THE NAM
IS STILL SUFFERING FROM OVERZEALOUS SNOWPACK INITIALIZATION AND
LLVL MOISTURE FIELDS LIKELY DUE TO POTENTIAL SNOW MELT AND HAD TO
SHY AWAY FROM IT FOR THIS FORECAST. FOR THE FORECAST TODAY...HAVE
WENT WITH VARYING CLOUD COVER THRU THE FIRST PART OF THE AFTN WITH
TEMPS SIMILAR TO RAP WITH READINGS RANGING FROM THE UPPER 20S IN
OUR NORTHERN CWA (NORTH OF FRONT) TO TEMPS IN THE 40S ACROSS MUCH
OF NORTH CENTRAL KS (SOUTH OF BOUNDARY). CLOUD COVER WILL INCREASE
AND TEMPS COOL N/S WITH ARRIVAL OF SECONDARY COLD FRONT LATER THIS
AFTN AND TONIGHT.
CLOUD COVER WITH FRONT/WAVE WILL BE AT MID/HIGH LEVELS SO NOT
LOOKING FOR PCPN WITH THE SECONDARY COLD FRONT THIS EVENING/TONIGHT.
COLDER CONDITIONS WILL SETTLE IN DURING THE NIGHT AS A 1045 MB
SURFACE HIGH BUILDS SOUTH FM THE DAKOTAS. THE AIRMASS CHANGE IS A
DROP OF NEARLY 10C AT H85 FROM THIS MORNING TO MONDAY MORNING.
OVERNIGHT LOWS PRIMARILY IN THE SINGLE DIGITS COMBINED WITH A STEADY
NORTH WIND WILL PRODUCE WIND CHILLS BELOW ZERO BUT VALUES ARE NOT
LOOKING QUITE COLD ENOUGH FOR AN HWO MENTION ATTM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 253 AM CST SUN JAN 11 2015
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM LIE WITH
TEMPERATURES AND EARLY WEEK PRECIPITATION CHANCES.
MONDAY STILL ON TRACK TO BE THE COLDEST DAY OF THE FORECAST
PERIOD...WITH MODELS IN GOOD AGREEMENT SHOWING THE CWA BEING ON THE
SOUTHERN END OF AN UPPER LEVEL TROUGH AXIS EXTENDING BACK UP INTO
THE HUDSON BAY AREA. THIS TROUGH CONTINUES TO SWING THROUGH/EAST OF
THE CWA DURING THE DAYTIME HOURS MONDAY...WITH ZONAL TO SLIGHT NWRLY
FLOW BUILDING IN BEHIND. EVEN WITH THIS TROUGH SWINGING
THROUGH...MODELS NOT SHOWING AN ABUNDANCE OF MOISTURE AND CONTINUE
TO KEEP CONDITIONS DRY. THIS SYSTEM BRINGS A REINFORCING SHOT OF
NRLY WINDS AND COLDER AIR...SPEEDS ARE ONLY TOPPING OUT AROUND 10 TO
15 MPH IN THE MORNING...BUT WILL DIMINISH WITH TIME AS SFC HIGH
PRESSURE SETTLES FURTHER SOUTH. THE CENTER OF THE SFC HIGH REMAINS
OFF TO THE N/NE OF THE CWA...ENDING UP OVER FAR NERN NEB AT
00Z...THEN SHIFTS OVER TO THE CENTRAL PORTIONS OF THE IA/MN BORDER
BY TUESDAY MORNING...WHICH WILL BRING A GRADUAL TRANSITION IN WINDS
TO THE EAST THAN MORE SOUTHERLY BY 12Z TUESDAY. DID NOT MAKE NOTABLE
CHANGES TO INHERITED HIGHS FOR MONDAY...WHICH RANGE FROM THE LOWER
TEENS IN THE FAR NORTH TO LOWER 20S ACROSS NC KS. OVERNIGHT LOWS
MONDAY NIGHT/TUESDAY MORNING LOOK TO BOTTOM OUT IN THE SINGLE DIGITS
BELOW ZERO IN THE NORTHEAST TO NEAR 10 DEGREES IN THE FAR SW.
TUESDAY/TUESDAY NIGHT...MAIN STORY LIES WITH AN UPPER LEVEL
DISTURBANCE WHICH BY SUNRISE TUESDAY HAS DUG SOUTH INTO THE CENTRAL
ROCKIES/4 CORNERS REGION...WITH ZONAL FLOW IN PLACE ACROSS OUR AREA.
THROUGH THE DAYTIME HOURS...MODELS IN DECENT AGREEMENT SHOWING A
CLOSED CIRCULATION DEVELOPING OVER THE 4 CORNERS REGION...AND
TREKKING MAINLY EAST INTO THE TUESDAY NIGHT PERIOD...BUT ALSO
FILLING WITH TIME. THE 00Z ECMWF/GFS/GEM ARE ALL IN PRETTY GOOD
AGREEMENT SHOWING THE BRUNT OF THIS SYSTEM SLIDING TO THE SOUTH OF
THE CWA...BARELY GETTING CLIPPED BY THE NRN EDGE OF
PRECIPITATION...IF AT ALL. DISCOUNTED THE 00Z NAM...WHICH WAS
NOTABLY FURTHER NORTH AND DEEPER WITH THE SYSTEM...AND SHOWED SOME
LOCATIONS GETTING UPWARDS OF 4 INCHES OF SNOW. THE 06Z RUN HAS COME
MORE IN LINE WITH THE ECMWF/GFS/GEM. CONTINUED TO KEEP SOME 30-40
POPS CONFINED TO THE FAR S/SWRN PORTIONS OF THE CWA...WITH SOME 20
POPS BUFFERING THAT AREA TO THE NORTH. AT THIS POINT...IF SNOW DOES
MAKE IT FAR ENOUGH NORTH TO AFFECT OUR CWA...NOT EXPECTING MUCH IN
THE WAY OF ACCUMULATION. EXPECTING A BUMP UP IN TEMPS...WITH HIGHS
CURRENTLY FORECAST TO REACH THE LOWER 20S.
THROUGH THE REMAINDER OF THE LONG TERM PERIOD...WEDNESDAY THROUGH
SATURDAY...THE FORECAST CONTINUES TO BE A DRY ONE...WITH MODELS IN
DECENT AGREEMENT SHOWING NORTHWESTERLY FLOW DEVELOPING FOR WED/THURS
THANKS TO AT LEAST BRIEF RIDGING OVER THE WRN CONUS...BEFORE
BECOMING MORE ZONAL INTO FRI/SAT WITH AN APPROACHING DISTURBANCE
FROM THE NW. EXPECTING MODERATING TEMPERATURES ALOFT TO WORK THEIR
WAY IN FROM THE WEST...AND ALONG WITH THE POTENTIAL FOR MORE
DOWNSLOPING WRLY WINDS ESP THURS/FRI...TEMPS CLIMB A BIT EACH
DAY...AND ARE FORECAST BACK IN THE LOW/MID 40S CWA-WIDE FOR FRIDAY.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1048 PM CST SAT JAN 10 2015
A COLD FRONTAL BOUNDARY IS WORKING SOUTH OF THE TERMINALS AT THIS
HOUR AND WINDS WILL BE FROM A LIGHT NORTHERLY DIRECTION THRU THE
TAF PERIOD. NEXT CONCERN IS THE POTENTIAL FOR STRATUS AND OR FOG
DEVELOPMENT OVERNIGHT BUT MODELS STILL LOOK A BIT ROBUST ON THIS
COMPARED TO CURRENT OBSERVATIONS AND WILL MONITOR TRENDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...ADP
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
733 PM PST MON JAN 12 2015
.SYNOPSIS...A STORM SYSTEM DROPPING OUT OF THE GREAT BASIN WILL
BRING UNSETTLED CONDITIONS TO LINCOLN AND MOHAVE COUNTIES TONIGHT
THROUGH TUESDAY AS IT DROPS INTO ARIZONA. GUSTY NORTH WINDS WILL
BUILD IN BEHIND THIS FEATURE ON TUESDAY ACROSS MUCH OF THE REGION.
HIGH PRESSURE AND SLOWLY REBOUNDING TEMPERATURES ARE EXPECTED
THROUGH THE WEEKEND WITH ONLY PERIODIC HIGH CLOUDS EXPECTED.
&&
.UPDATE...TRACKING A COLD FRONT MOVING SOUTH THROUGH THE SOUTHERN
GREAT BASIN THIS EVENING AS WELL AS AN ASSOCIATED BAND OF
PRECIPITATION MOVING THROUGH LINCOLN COUNTY. THIS PRECIPITATION BAND
WAS SITUATED BETWEEN ALAMO AND MESQUITE AT THIS HOUR. PRECIPITATION
IS EXPECTED TO END RAPIDLY BEHIND THIS FRONT WHILE ALONG THE FRONT
THE HRRR SUGGESTS THE DEVELOPMENT FURTHER WEST INTO CLARK...INYO AND
SAN BERNARDINO COUNTIES THAT WHAT WE HAD IN THE FORECAST. HAVE
UPDATED POP/WX/SKY/QPF GRIDS TO REFLECT THE CURRENT TRENDS AND TO
INTRODUCE SLIGHT CHANCE POPS FOR PORTIONS OF THE WESTERN CWA AS WELL
AS THE LAS VEGAS VALLEY WHERE A FEW SPRINKLES MAY FALL BETWEEN
06-10Z TONIGHT. HAVE ALSO INCLUDED A MENTION OF PATCHY FOG FOR
WESTERN SAN BERNARDINO COUNTY THROUGH 09Z TONIGHT IN RESPONSE TO FOG
REPORTED IN RIDGECREST. AFTER 09Z NORTHERLY WINDS ASSOCIATED WITH
THE FRONT SHOULD MIX THINGS UP WELL ENOUGH TO REMOVE FURTHER CHANCES
OF FOG.
&&
.AVIATION...FOR MCCARRAN...PERIODS OF SCT-BKN CLOUD COVER ARE
ANTICIPATED OVERNIGHT BUT CIGS ARE EXPECTED TO REMAIN AOA 5K FT.
THERE WILL BE A SLIGHT CHANCE OF A FEW SPRINKLES BETWEEN 06Z-10Z
TONIGHT. WINDS TONIGHT MAY TO TRANSITION FROM A SOUTHERLY DIRECTION
TO A NORTH/NORTHWEST DIRECTION AT 8 TO 12 KTS WITH GUSTS TO 20 KTS
BETWEEN 06Z-10Z...HOWEVER CONFIDENCE IS LOW. CONFIDENCE IS HIGHER
THAT THESE NORTHERLY WINDS WILL IMPACT THE TERMINAL BY 15Z-18Z.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCT-BKN CLOUD COVER CAN BE EXPECTED OVERNIGHT WITH CIGS
BETWEEN 4K-9K FT. BKN-OVC CONDITIONS WILL BE MORE PREVALENT EAST OF
A KMLF-KLAS-KEED LINE TONIGHT WHERE SHOWERS WILL BE POSSIBLE. PATCHY
FOG IS ONCE AGAIN POSSIBLE ACROSS EASTERN SAN BERNARDINO COUNTY
THROUGH ROUGHLY MIDNIGHT. WIDESPREAD NORTHERLY WINDS CAN BE EXPECTED
BY TUESDAY MORNING...STRONGEST ALONG THE COLORADO RIVER.
&&
.PREV DISCUSSION...
ISSUED 205 PM PST MON JAN 12 2015
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT...
CONSIDERABLE CLOUD COVER REMAINS ACROSS MUCH OF THE FORECAST AREA
THIS AFTERNOON WITH EVEN A FEW POCKETS OF FOG PERSISTING EARLY THIS
AFTERNOON...ESPECIALLY ACROSS THE WESTERN DESERTS OF SAN BERNARDINO
COUNTY NEAR SEARLES VALLEY. MEANWHILE A TROUGH OF LOW PRESSURE IS
DIGGING SOUTH OUT OF THE NORTHERN GREAT BASIN AND IS EXPECTED TO
SWING INTO ARIZONA BY MIDDAY TOMORROW. THIS FEATURE WILL AID IN
BREAKING OUT PRECIPITATION ACROSS LINCOLN COUNTY THIS EVENING AND
PERSISTING OVERNIGHT IN MOHAVE COUNTY AS THE STORM MOVES THROUGH.
SHOWER ACTIVITY MAY BREAK OUT AS FAR WEST AS LAKE MEAD BUT GREATEST
PROBABILITIES WILL BE FURTHER EAST. BY TOMORROW AFTERNOON THE LOW
WILL HAVE PUSHED WELL SOUTH AND EAST TO BE LOCATED ACROSS NORTHERN
ARIZONA WITH IMPROVING CONDITIONS EXPECTED ACROSS OUR REGION.
ONE OTHER NOTE...THIS STORM SYSTEM WILL BRING A MARKED PUSH OF
NORTH WINDS ACROSS THE AREA LATE TONIGHT ACROSS OUR SOUTHERN GREAT
BASIN ZONES AND BY LATE MORNING ACROSS OUR SOUTHERN DESERT ZONES
SOUTH OF INTERSTATE 40. GUSTY CONDITIONS CAN BE EXPECTED ALONG THE
COLORADO RIVER BUT WIND SPEEDS TO LOOK TO STAY A BIT SHY OF ANY WIND
PRODUCTS.
.LONG TERM...WEDNESDAY THROUGH SUNDAY...
HIGH PRESSURE RIDGING WILL RETURN MIDWEEK ONWARD ALLOWING FOR
TEMPERATURES TO GRADUALLY CLIMB BACK INTO ABOVE NORMAL TERRITORY.
TEMPERATURES OVER THE WEEKEND LOOK TO AVERAGE 4 TO 6 DEGREES ABOVE
SEASONAL AVERAGES UNDER PERIODS OF HIGH CLOUDS. MODELS HAVE BEEN
TRENDING TOWARDS MAINTAINING HIGH PRESSURE OVER THE REGION AND
KEEPING THE STORM TRACK WELL TO OUR NORTH THROUGH AT LEAST EARLY
NEXT WEEK SO I TRIMMED THE VERY LIMITED POPS WE HAD IN PLACE FOR
SOME OF OUR SIERRA AND NORTHERN GREAT BASIN ZONES IN FAVOR OF A
DRIER FORECAST.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT REQUESTED
BUT SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS
ACCORDING TO STANDARD OPERATING PROCEDURES.
&&
$$
UPDATE/AVIATION...WOLCOTT
PREV DISCUSSION...OUTLER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
905 AM PST SUN JAN 11 2015
.SYNOPSIS...UNSETTLED WEATHER WILL CONTINUE ACROSS THE REGION
THROUGH MONDAY AS TWO SYSTEMS PUSH THROUGH. THE FIRST WILL BRING
PRECIPITATION ACROSS MUCH OF THE MOJAVE DESERT TODAY. THE SECOND
WILL PUSH ACROSS THE SOUTHERN GREAT BASIN INTO UTAH AND ARIZONA
MONDAY BRINGING ADDITIONAL CHANCES FOR PRECIPITATION TO THOSE AREAS.
DRY AND PLEASANT WEATHER WILL RETURN TUESDAY THROUGH NEXT WEEK.
&&
.UPDATE...A BROAD ARC OF PRECIPITATION COULD BE SEEN ON MOSAIC RADAR
LOOPS EXTENDING FROM THE SOUTHERN CALIFORNIA COAST ACROSS
WESTERN AND NORTHERN SAN BERNARDINO COUNTY INTO CLARK COUNTY NEVADA
THIS MORNING. THE LATEST HRRR AND NAM/GFS QPF DEPICTIONS INDICATE
THIS ARC...ON THE NORTHERN PERIPHERY OF A CIRCULATION CURRENTLY
CENTERED NEAR LOS ANGELES...WILL SLOWLY MIGRATE TO THE EAST TODAY
THEN SLOWLY LOSE DEFINITION THIS EVENING AS THE ASSOCIATED
CIRCULATION MOVES INTO SOUTHERN ARIZONA. THIS WILL PRODUCE LIKELY TO
CATEGORICAL PRECIPITATION ACROSS THE AREA BETWEEN I-40 AND DEATH
VALLEY...NORTHERN CLARK COUNTY AND THE WESTERN GRAND CANYON.
POP/WX/QPF GRIDS WERE UPDATED ACCORDINGLY. STORM TOTAL QPF AMOUNTS
HAVE BEEN INCREASED TO REFLECT AND AVERAGE BETWEEN 0.25-0.50 INCHES
ACROSS CENTRAL CLARK COUNTY AND THE SPRING MOUNTAINS TODAY.
&&
.AVIATION...FOR MCCARRAN...A STORM OVER SOUTHERN CALIFORNIA WILL
SPREAD RAIN AND LOW CIGS INTO THE LAS VEGAS AREA THE REST OF TODAY
THEN TAPER OFF THIS EVENING. PERIODS OF LIGHT TO MODERATE RAIN CAN
BE EXPECTED THROUGH LATE THIS AFTERNOON AND CIGS WILL LIKELY LOWER
TO AROUND 3K FEET. WINDS WILL REMAIN LIGHT...GENERALLY UNDER 8
KTS THROUGH THE PERIOD. THERE IS A VERY (EMPHASIS ON VERY) REMOTE
CHANCE OF FOG DEVELOPMENT OVERNIGHT IF WETTING RAIN FALLS IN/AROUND
THE TERMINAL TODAY AND SKIES CLEAR OVERNIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...A BROAD AREA OF RAIN WILL CONTINUE TO SPREAD ACROSS
SOUTHEAST CALIFORNIA...FAR SOUTHERN NEVADA AND NORTHWEST ARIZONA
TODAY. CLOUD BASES WILL LOWER TO 3K-7K FEET IN AND NEAR ANY
SHOWERS WITH MOUNTAIN OBSCURATIONS LIKELY. VSBY WILL MAINLY BE VFR
WITH MVFR OR LOWER IN ANY HEAVIER SHOWERS. WINDS WILL REMAIN
GENERALLY LIGHT THROUGH THE PERIOD. PATCHY FOG DEVELOPMENT WILL BE
POSSIBLE TONIGHT IN AREAS THAT SEE WETTING RAIN TODAY AND CLEARING
SKIES TONIGHT.
&&
.PREV DISCUSSION...
223 AM PST SUN JAN 11 2015
.SHORT TERM...TODAY THROUGH MONDAY NIGHT...ACT TWO OF THE THREE
SYSTEM WEEKEND IS UNDERWAY THIS MORNING WITH LIGHT RAIN BEING
REPORTED ACROSS THE WESTERN PORTIONS OF SAN BERNARDINO COUNTY.
AMOUNTS HAVE BEEN LIGHT THUS FAR...STAYING UNDER A TENTH OF AN INCH
AS OF 2 AM. THIS AREA OF PRECIPITATION WILL CONTINUE TO SLOWLY
EXPAND NORTHEAST THIS MORNING BEFORE TRANSLATING EAST ACROSS FAR
SOUTHERN NEVADA AND NORTHWEST ARIZONA THIS AFTERNOON INTO TONIGHT.
THE CORE OF THE TOTAL PRECIPITATION WITH THIS SYSTEM IS EXPECTED TO
FALL ALONG A 120-180 MILE WIDE BAND CENTERED ON A LINE FROM ROUGHLY
BARSTOW TO SEARCHLIGHT TO KINGMAN. IN THIS BAND QPF TOTALS ARE
EXPECTED TO BE BETWEEN 0.10-0.33 INCHES...WITH LIGHTER AMOUNTS
FALLING TO THE NORTH AND SOUTH. LAS VEGAS WILL LIKELY BE SITUATED
ALONG THE NORTHERN FRINGE OF THIS BAND...AND CURRENT ESTIMATES ARE
RAINFALL TOTALS OF A TRACE TO ONE-TENTH OF AN INCH FOR THE VALLEY.
SNOW LEVELS WILL HOVER IN THE 7000-800 FOOT RANGE...AND THUS
SNOWFALL WILL ONLY BE A FACTOR ON THE HIGHEST ROADS...AND EVEN
THERE...SNOWFALL TOTALS SHOULD REMAIN IN THE 1-3 INCH RANGE.
CONDITIONS SHOULD IMPROVE IN MOST AREAS BY THIS EVENING AS DRIER AIR
TRIES TO WORK IN. HOWEVER...THERE IS SLIGHT CONCERN FOR THE
DEVELOPMENT OF PATCHY FOG IN AREAS THAT SEE WETTING RAIN TODAY AND
CLEARING SKIES TONIGHT. DON`T HAVE MUCH CONFIDENCE IN AREAS AT THIS
TIME AND WILL LET SUBSEQUENT SHIFTS TAKE ANOTHER LOOK AT THAT
POTENTIAL FOR TONIGHT.
ANOTHER SYSTEM WILL DIVE SOUTH ACROSS THE SOUTHERN GREAT BASIN
MONDAY. MODELS HAVE SHOWN A SIGNIFICANT EASTWARD TREND IN THIS
SYSTEM OVER THE PAST COUPLE DAYS. AS A RESULT HAVE KNOCKED DOWN
PRECIPITATION CHANCES IN MAY AREAS FOR MONDAY. THE BEST CHANCES WILL
RESIDE OVER EASTERN LINCOLN AS WELL AS CENTRAL AND NORTHERN MOHAVE
COUNTIES. THIS SYSTEM HAS A BIT LESS MOISTURE TO WORK WITH AND SNOW
LEVELS WILL REMAIN GENERALLY ABOVE 6000-6500 FEET...THUS SIGNIFICANT
ACCUMULATING SNOW IS NOT ANTICIPATED. THIS SECOND SYSTEM WILL EXIT
THE AREA MONDAY NIGHT/TUESDAY MORNING.
.LONG TERM...TUESDAY THROUGH SATURDAY...BY TUESDAY MORNING EXPECT
THE TROUGH TO BE AMPLIFYING OVER UTAH...WITH ANY LEFTOVER PRECIP
CHANCES CONFINED TO THE FAR EASTERN FRINGES OF THE CWA. NORTHERLY
FLOW BETWEEN THE TROUGH AND A HIGH AMPLITUDE RIDGE ALONG THE WEST
COAST WILL BRING GUSTY NORTH WINDS TO THE FAVORED AREAS TUESDAY AND
WEDNESDAY...PARTICULARLY THE COLORADO RIVER VALLEY. A WEAK TROUGH
PASSING THROUGH THE PACIFIC NORTHWEST WEDNESDAY INTO THURSDAY
FLATTENS THE RIDGE...LEAVING WEAK WESTERLY FLOW OVER OUR AREA WITH
HIGH HEIGHTS THURSDAY INTO FRIDAY. BY SATURDAY THERE IS MODEL
AGREEMENT ON THE EXISTENCE OF A TROUGH JUST OFF THE WEST COAST...BUT
CONSIDERABLE SPREAD IN ITS EXACT LOCATION AND STRENGTH. THAT WILL BE
SOMETHING TO WATCH IN THE NEAR FUTURE...BUT FOR THE TIME BEING...IT
SHOULD BE DRY THROUGH THE LONG TERM WITH TEMPERATURES RUNNING A FEW
DEGREES ABOVE AVERAGE FOR MID JANUARY.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT REQUESTED
BUT SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS
THROUGH MONDAY ACCORDING TO STANDARD OPERATING PROCEDURES.
&&
$$
UPDATE/AVIATION...ADAIR
SHORT TERM...WOLCOTT
LONG TERM.............MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1221 AM CST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1221 AM CST SUN JAN 11 2015
LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH PUSHING SOUTH
INTO SOUTHERN ALBERTA/SASKATCHEWAN EARLY THIS MORNING. THE RIGHT
ENTRANCE REGION OF A 110KT 300MB JET WAS RESULTING IN LARGE SCALE
ASCENT PER 850-300MB OMEGA FIELD ACROSS WESTERN NORTH DAKOTA.
HOWEVER WITH A LACK OF A SURFACE FEATURE...THE OMEGA/VERTICAL MOTION
FIELD IS MORE OR LESS MAXIMIZED IN THE 700-500 LAYER PER LATEST TIME
HEIGHT CROSS SECTIONS. THIS IS FORECAST TO SLIDE EAST INTO SOUTH
CENTRAL NORTH DAKOTA BETWEEN 09Z AND 15Z SUNDAY. LATEST
RAP13/NAM/GFS/HRRR PRODUCE AN AREA OF LIGHT SNOW FROM KDIK TO KBIS
AND JUST SOUTH OF KJMS DURING OVERNIGHT. HAVE USED A BLEND OF THESE
SOLUTIONS TO INCREASE POPS OVER SOUTH CENTRAL NORTH DAKOTA
OVERNIGHT. EXPECTING ABOUT A HALF INCH IN THE SOUTHWEST TO THE
SOUTHERN BORDER...WITH AROUND TWO TENTHS FARTHER NORTH ALONG/NEAR
I-94. LATEST NAM/RAP13 BUFKIT SOUNDINGS SHOW THE OMEGA LAYER IS
CENTERED IN THE DENDRITIC GROWTH ZONE IN A SUPERSATURATED
ENVIRONMENT WITH RESPECT TO ICE...WITH THE FROST POINT EXCEEDING THE
TEMPERATURE PROFILE. BUT AS MENTIONED ABOVE...MAIN THING LACKING
FOR MORE INTENSE SNOWFALL DEVELOPMENT IS THERE IS NOTHING AT THE
SURFACE BEING REFLECTED TO ENHANCE CONVERGENCE...NO SIGNIFICANT
PRESSURE FALLS/NO SURFACE LOW/FRONT. ONCE THIS SHORTWAVE PASSES
BY...LARGE SCALE SUBSIDENCE TAKES CONTROL WITH A DISTINCT/SHARP
CLEARING LINE DEVELOPING IN THE NORTHWEST SUNDAY MORNING...AND
INTO SOUTH CENTRAL NORTH DAKOTA DURING THE EARLY AFTERNOON.
THE WIND CHILL ADVISORY IS HAVING A HARD TIME MEETING CRITERIA
EXCEPT IN THE TURTLE MOUNTAINS. WILL LET IT CONTINUE FOR NOW AND
REVISIT IT FOR THE NEXT FORECAST CYCLE. THE CLEARING LINE IS IN
SOUTHERN CANADA WHERE CURRENT WIND CHILL TEMPERATURES ARE 30 TO 36
BELOW ZERO...SO WE MAY ACTUALLY SEE BETTER VERIFICATION OF THE WIND
CHILL ADVISORY LATER SUNDAY MORNING AS CLOUDS DIMINISH AND
CLEARING SETS IN.
UPDATE ISSUED AT 923 PM CST SAT JAN 10 2015
MAIN CHANGE FOR LATE EVENING UPDATE WAS TO RAISE LOW TEMPERATURES
A BIT OVER THE NORTH CENTRAL AS CLOUD COVER HAS PUSHED WELL INTO
THE AREA. HAVE ALSO ADJUSTED POPS UP A LITTLE OVER THE
WEST...ALTHOUGH STILL SOME QUESTION ON HOW MUCH SNOW IF ANY WILL
MAKE IT TO THE GROUND WITH A RELATIVELY DRY LOWER ATMOSPHERE.
UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 625 PM CST SAT JAN 10 2015
PREVIOUS FORECAST WAS IN PRETTY GOOD SHAPE WITH ONLY CHANGE BEING
ADVANCING CLOUDS A LITTLE FASTER THAN PREVIOUSLY THOUGHT.
OTHERWISE...SNOW CHANCES CONTINUE FOR LATER THIS EVENING MAINLY
WEST INTO PORTIONS OF SOUTH CENTRAL. WILL KEEP AN EYE ON HOW THIS
EVOLVES OVER MONTANA TO SEE IF ANY CHANGES ARE NEEDED ON
SUBSEQUENT UPDATES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 301 PM CST SAT JAN 10 2015
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS SNOW CHANCES
WITH AN APPROACHING SHORTWAVE LATE TONIGHT THROUGH SUNDAY
MORNING...AND WIND CHILLS NORTH TONIGHT THROUGH MIDDAY SUNDAY.
A SHORTWAVE MOVING THROUGH MEAN WRN CANADA UPPER RIDGE CURRENTLY
MOVING FROM BRITISH COLUMBIA INTO ALBERTA...WILL COMBINE WITH A
NORTHERN STREAM SAVE DROPPING SOUTH FROM THE NORTHWEST TERRITORIES
AND MOVE INTO THE NORTHERN PLAINS LATE TONIGHT INTO SUNDAY. MID
LEVEL FORCING WILL PRODUCE A BAND OF LIGHT SNOW SPREADING FROM THE
LEE OF THE CANADIAN ROCKIES INTO EASTERN MONTANA THIS
EVENING...AND THEN ACROSS WESTERN NORTH DAKOTA AND INTO NORTHERN
SOUTH DAKOTA LATE TONIGHT THROUGH SUNDAY MORNING. THE TREND FROM
PREVIOUS RUNS HAS BEEN A LITTLE FARTHER NORTH WITH THE LIGHT
SNOW. HAVE UTILIZED BASICALLY A BLEND OF DETERMINISTIC GUIDANCE
WHICH BRINGS SLIGHT CHANCE TO CHANCE POPS MAINLY WEST AND SOUTH OF
LAKE SAKAKAWEA AND THE MISSOURI RIVER TONIGHT AND INTO THE FAR
SOUTH CENTRAL SUNDAY MORNING. THE LATEST MESOSCALE RAP AND HRRR
CONTINUE TO BRING THE BAND OF LIGHT SNOW EVEN A LITTLE FARTHER
NORTH...LIFTING NORTH AND EAST OF THE MISSOURI. WILL STICK WITH
THE CURRENT BLEND FOR NOW. SNOW AMOUNTS ARE EXPECTED TO BE LIGHT
WITH UNDER A HALF INCH...WITH POSSIBLY A HALF INCH TO AN INCH FROM
THE WEST CENTRAL INTO SOUTHWEST NORTH DAKOTA.
TO THE NORTH AND EAST...TEMPERATURES ARE IN THE SINGLE DIGITS
ABOVE ZERO ALONG THE CANADIAN BORDER...AND SHOULD DROP QUICKLY
THIS EVENING. WINDS WILL NOT BE STRONG BUT A STEADY 5 TO 10 MPH.
THIS WILL PRODUCE ADVISORY CRITERIA WINDS AGAIN LATE THIS EVENING
THROUGH SUNDAY MORNING ALONG THE CANADIAN BORDER. WILL ISSUE
ANOTHER ADVISORY TO COVER THIS.
SUNDAY WILL BRING TEMPERATURES SIMILAR TO TODAY WITH HIGHS FROM
NEAR ZERO NORTHEAST TO THE LOWER TEENS SOUTHWEST AND SOUTH
CENTRAL.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 301 PM CST SAT JAN 10 2015
COLD WITH DANGEROUS WIND CHILLS SUNDAY NIGHT...FOLLOWED BY A WARMING
TREND.
UPPER LEVEL NORTHWEST FLOW AND A LARGE SURFACE ARCTIC HIGH PRESSURE
SYSTEM WILL BE IN PLACE SUNDAY EVENING...WITH THE FORECAST CENTER OF
THE ARCTIC HIGH OVER SOUTHEASTERN SASKATCHEWAN/NORTHWESTERN
NORTH DAKOTA AROUND SUNSET SUNDAY EVENING. THE HIGH CENTER MOVES
SOUTHEAST ACROSS THE STATE SUNDAY NIGHT. BY DAYBREAK MONDAY MORNING
THE HIGH CENTER SHOULD BE OVER THE EASTERN DAKOTAS. NORTHWEST WINDS
SHOULD BE RATHER LIGHT - 5 TO 10 MPH SUNDAY EVENING AND UP TO 5 MPH
LATE SUNDAY NIGHT. LOW TEMPERATURES SHOULD BOTTOM OUT AROUND 15 TO
20 BELOW OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA. THE HIGH
CENTER SHOULD BE NORTH AND EAST OF THE SOUTHWESTERN PORTION OF THE
STATE...AND THERE THE OVERNIGHT LOWS SHOULD BE IN THE 10 TO 15 BELOW
ZERO RANGE. THESE MINIMUM TEMPERATURES COMBINED WITH THE WINDS UP TO
10 MPH AT TIMES WILL COMBINE TO PRODUCE WIND CHILLS IN THE 25 TO 30
BELOW ZERO RANGE (PERHAPS SOME ISOLATED LOCALES REACHING 35 BELOW
ZERO WIND CHILLS) FOR ALL BUT THE FAR SOUTHWESTERN COUNTIES OF NORTH
DAKOTA.
MONDAY AND MONDAY NIGHT: THE ARCTIC HIGH PRESSURE WILL CONTINUE
MOVING SOUTHEAST...AND THE UPPER LEVEL FLOW BEGINS CHANGING FROM
NORTHWEST TO A MORE ZONAL FLOW. LOOKING AT HIGHS MONDAY FROM JUST
ABOVE ZERO IN THE TURTLE MOUNTAINS AND JAMES RIVER VALLEY...TO THE
LOWER TEENS IN THE SOUTHWEST. LOWS WILL STILL BE BELOW ZERO MONDAY
NIGHT AS THE RESIDUAL ARCTIC AIR REMAINS OVER THE REGION.
THE CHANGING WEATHER PATTERN SHOULD BEGIN TO BE FELT ON TUESDAY AS
AN UPPER LEVEL RIDGE BEGINS BUILDING INTO THE WESTERN PLAINS...AND
AS SOUTHERLY SURFACE WINDS BEGIN TO BRING A MILDER PACIFIC AIRMASS
INTO THE REGION. LOOKING AT HIGHS TUESDAY IN THE TEENS AND LOWER 20S.
DRY CONDITIONS WILL CONTINUE AND TEMPERATURES WILL CONTINUE TO
MODERATE THROUGH THE WEEK AS PACIFIC RIDGING CONTINUES TO BUILD.
HIGHS ARE FORECAST TO BE AROUND AVERAGE (20S TO LOWER 30S) ON
WEDNESDAY...AND ABOVE AVERAGE (UPPER 20S TO MID/UPPER 30S) THURSDAY
THROUGH SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1221 AM CST SUN JAN 11 2015
A PERIOD OF LIGHT SNOW AND MVFR CIGS/VSBYS CAN BE EXPECTED AT
KDIK/KBIS THROUGH MID MORNING SUNDAY. KDIK WILL LIKELY HOLD ONTO THE
MVFR CIGS UNTIL MID AFTERNOON...WHILE KBIS WILL BEGIN TO SEE CIGS BY
15Z SUNDAY. THE REST OF THE TERMINALS WILL REMAIN VFR WITH A
CLEARING SKY COMMENCING DURING THE DAY SUNDAY FROM NORTHWEST TO
SOUTHEAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR NDZ002>005-011>013.
&&
$$
UPDATE...KS
SHORT TERM...TWH
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
316 PM EST SUN JAN 11 2015
.SYNOPSIS...
RAIN TONIGHT. A COLD FRONT MOVE THROUGH ON MONDAY. WEAK WAVE OF LOW
PRESSURE SOUTH POSSIBLE MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
REMAIN CONCERNED WITH THE MODEL TRENDS OF GETTING WARMER FOR
TONIGHT IN SOUTHEAST OHIO AND EXTREME NORTHWESTERN WV. MET/MAV AND
LAV GUIDANCE ARE WARMER THAN THE FORECAST...BUT THE HRRR STILL SHOWS
WET BULBING CAUSING ISSUES. WITH SUCH LOW DEW POINTS
CURRENTLY...FROZEN GROUND...AND ADVISORIES ALREADY IN PLACE...WILL
HOLD TIGHT...BUT EVENING SHIFT WILL NEED TO MONITOR THIS CLOSELY.
HRRR AND NAM SOUNDINGS SHOWING POTENTIAL PROBLEMS IN THE SOUTHEAST
UPSLOPE AREAS OF THE NORTHERN MOUNTAINS AS WELL. IN THIS REGION
HOWEVER...LAV GUIDANCE IS SHOWING TEMPERATURE HOOVERING RIGHT AROUND
FREEZING AT LWB...WHICH IS NOT NORMALLY THE COLDEST SPOT. WITH
GROUND FROZEN...THINK THAT POCKETS OF FREEZING RAIN A GOOD BET. WILL
ISSUE A FREEZING RAIN ADVISORY OVERNIGHT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
WITH THE FRONTAL BOUNDARY OFF TO THE SOUTHEAST...WILL BE INFLUENCED
BY A DEVELOPING INVERTED SURFACE TROUGH SETTING UP ALONG THE
MOUNTAINS IN COMBINATION WITH A WEAK MID AND UPPER LEVEL WAVE. THE
RESULT IN THE GRIDS IS NOT TOO MUCH OF A CHANGE IN TERMS OF THE
POPS...KEEPING THE LOW END POPS OVER THE MOUNTAINS BEFORE ENDING
WEDNESDAY. LARGELY BASED THE POPS ON LOW-MID LEVEL LAYER
FRONTOGENESIS WHICH IS ON THE WEAKER SIDE...BUT STILL PRESENT WHEN
LOOKING AT THE NAM.
AN OVERRUNNING SITUATION WILL BE PRESENT WITH THE MOISTURE OVER THE
MOUNTAINS AS THE TROUGH SETS UP AND WILL KEEP IT SIMPLE IN THE
WEATHER GRIDS BY USING THE WARM LAYER ALOFT FROM THE NAM. THIS
CREATES BRIEF SLEET/FREEZING RAIN POTENTIAL BEFORE THE COLD AIR
ADVECTION TAKES HOLD AND TRANSITIONS THE WEATHER TYPE TO ALL SNOW
INTO TUESDAY. ALL THE WHILE...POPS WILL BE LOWERING.
NOT SEEING MUCH OF A TEMPERATURE RECOVERY TUESDAY FROM MONDAY NIGHT
GIVEN THE CLOUD COVER AND WEAK COLD AIR ADVECTION WHICH WILL BE HELD
IN CHECK BY THE MOISTURE PUSH FROM THE AFOREMENTIONED SURFACE TROUGH
FROM THE SOUTH. KEEPING IT COLD ENOUGH IN THE FORECAST FOR OFF AND
ON LIGHT SNOW OVER THE MOUNTAINS AFTER THE FULL PRECIPITATION TYPE
TRANSITION TUESDAY AND TUESDAY NIGHT...WITH SOME LOCATIONS CLIMBING
ABOVE FREEZING WEDNESDAY AS 850MB TEMPERATURES MODIFY SLIGHTLY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
COLDER AIR SWEEPS IN FOR A SEASONABLY COOL EXTENDED. EXPECTING A
MAINLY DRY EXTENDED IS IN THE CARDS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
CLOUDS WILL GRADUALLY BE LOWERING WITH PRECIPITATION MOVING IN
TONIGHT. THE PRECIPITATION WILL BE RAIN FOR MOST OF THE REGION...BUT
SOME SLEET OR FREEZING RAIN IS POSSIBLE IN THE SOUTHEAST UPSLOPE
AREAS OF POCAHONTAS COUNTY...AND CENTRAL OHIO AND EXTREME
NORTHWESTERN WV. A COLD FRONT WILL PUSH THROUGH ON MONDAY...WITH
MORE RESTRICTIONS IN CEILINGS AND PRECIPITATION POSSIBLE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: HIGH THIS AFTERNOON...THEN MEDIUM.
ALTERNATE SCENARIO: TIMING OF LOWERING CEILINGS AND VISIBILITY
RESTRICTIONS COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05
06 07 EST 1HRLY 15 16 17 18 19 20 21 22 23
00 01 02 CRW CONSISTENCY H H H H H H H
H H M M M HTS CONSISTENCY H H H H H H
H H H M H H BKW CONSISTENCY H H H H H
H H H H M M H EKN CONSISTENCY H H H H
H H H H H H H M PKB CONSISTENCY H H H
H H H H H M M M M CKB CONSISTENCY H H
H H H H H H H H M H
AFTER 18Z MONDAY...
IFR POSSIBLE MONDAY AFTERNOON...AND IN THE MOUNTAINS AND SOUTHERN
COUNTIES MONDAY NIGHT AND TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR WVZ046-047.
FREEZING RAIN ADVISORY UNTIL 6 AM EST MONDAY FOR WVZ009>011.
OH...WINTER WEATHER ADVISORY UNTIL 9 AM EST MONDAY FOR OHZ066-067.
FREEZING RAIN ADVISORY UNTIL 6 AM EST MONDAY FOR OHZ075-076-
083>085.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...RPY
SHORT TERM...26
LONG TERM...30
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
222 PM EST SUN JAN 11 2015
.SYNOPSIS...
RAIN TONIGHT. A COLD FRONT MOVE THROUGH ON MONDAY. WEAK WAVE OF LOW
PRESSURE SOUTH POSSIBLE MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
REMAIN CONCERNED WITH THE MODEL TRENDS OF GETTING WARMER FOR
TONIGHT IN SOUTHEAST OHIO AND EXTREME NORTHWESTERN WV. MET/MAV AND LAV
GUIDANCE ARE WARMER THAN THE FORECAST...BUT THE HRRR STILL SHOWS WET
BULBING CAUSING ISSUES. WITH SUCH LOW DEW POINTS CURRENTLY...FROZEN
GROUND...AND ADVISORIES ALREADY IN PLACE...WILL HOLD TIGHT...BUT
EVENING SHIFT WILL NEED TO MONITOR THIS CLOSELY.
HRRR AND NAM SOUNDINGS SHOWING POTENTIAL PROBLEMS IN THE SOUTHEAST
UPSLOPE AREAS OF THE NORTHERN MOUNTAINS AS WELL. IN THIS REGION
HOWEVER...LAV GUIDANCE IS SHOWING TEMPERATURE HOOVERING RIGHT AROUND
FREEZING AT LWB...WHICH IS NOT NORMALLY THE COLDEST SPOT. WITH
GROUND FROZEN...THINK THAT POCKETS OF FREEZING RAIN A GOOD BET. WILL
ISSUE A FREEZING RAIN ADVISORY OVERNIGHT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
TEMPERATURES ALREADY MAINLY ABOVE FREEZING TO START THE
PERIOD...EXCEPT FOR VERY NW CWA IN PERRY AND MORGAN COUNTY. SO
LINGER WINTER WEATHER ADVISORY THERE UNTIL 9AM FOR FREEZING
RAIN...POSSIBLY MIXED WITH SOME SLEET/SNOW. HAVE HIGH POPS AT THE
START OF THE PERIOD...AS COLD FRONT BEGINS MOVING THROUGH. THAT
FRONT WILL CROSS CWA MONDAY WITH MAINLY RAIN. AS THE COLD AIR WORKS
IN LATER MONDAY AND MONDAY NIGHT...EXPECT A TRANSITION FROM RAIN TO
SLEET TO SNOW. MOISTURE ALREADY BECOMING FAIRLY LIMITED BY THE TIME
COLD ENOUGH AIR WORKS IN FOR SNOW...SO ONLY HAVE LIGHT ACCUMULATIONS
AND MAINLY IN THE NORTHERN MOUNTAINOUS COUNTIES.
A WAVE RIDES UP THE FRONT TUESDAY...SO HANG ONTO POPS ACROSS THE
EAST INTO TUESDAY NIGHT...THEN GRADUALLY DECREASE. DO HAVE HIGHER
POPS FOR THIS THAN PREVIOUS FORECAST...BUT STILL ONLY GETTING UP TO
AROUND A 40 PERCENT CHANCE AS THE MAIN ACTIVITY LOOKS TO STAY SE OF
CWA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
COLDER AIR SWEEPS IN FOR A SEASONABLY COOL EXTENDED. AFTER THE
SYSTEM MONDAY/EARLY TUESDAY...APPEARS A MAINLY DRY EXTENDED IS IN
THE CARDS. THE MODELS CONTINUE E WITH SYSTEM MIDWEEK. DID LEAVE SOME
SMALL POPS ACROSS E HALF OF CWA FOR MIDWEEK AS THIS SYSTEM MAY TREND
A BIT W WITH TIME.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
CLOUDS WILL GRADUALLY BE LOWERING WITH PRECIPITATION MOVING IN
TONIGHT. THE PRECIPITATION WILL BE RAIN FOR MOST OF THE REGION...BUT
SOME SLEET OR FREEZING RAIN IS POSSIBLE IN THE SOUTHEAST UPSLOPE
AREAS OF POCAHONTAS COUNTY...AND CENTRAL OHIO AND EXTREME
NORTHWESTERN WV. A COLD FRONT WILL PUSH THROUGH ON MONDAY...WITH
MORE RESTRICTIONS IN CEILINGS AND PRECIPITATION POSSIBLE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: HIGH THIS AFTERNOON...THEN MEDIUM.
ALTERNATE SCENARIO: TIMING OF LOWERING CEILINGS AND VISIBILITY
RESTRICTIONS COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H M
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
IFR POSSIBLE MONDAY AFTERNOON...AND IN THE MOUNTAINS AND SOUTHERN
COUNTIES MONDAY NIGHT AND TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR WVZ046-047.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR WVZ009>011.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM EST
MONDAY FOR OHZ066-067.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR OHZ075-076-083>085.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...RPY
SHORT TERM...MZ
LONG TERM...30
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1213 PM EST SUN JAN 11 2015
.SYNOPSIS...
MOISTURE/CLOUDS INCREASES TODAY...BUT NOT QUITE AS COLD IN AFTERNOON.
COLD FRONT SAGS SOUTH MONDAY. WEAK WAVE OF LOW PRESSURE SOUTH
POSSIBLE MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
BASED ON LATEST MODELS AND SATELLITE TRENDS...WILL INCREASE CLOUD
COVER FOR THIS AFTERNOON.
AM A BIT CONCERNED WITH THE MODEL TRENDS OF GETTING WARMER FOR THIS
AFTERNOON AND TONIGHT IN SOUTHEAST OHIO. MET/MAV AND LAV GUIDANCE
ARE MUCH WARMER THAN FORECAST...BUT THE HRRR STILL SHOWS WET BULBING
CAUSING ISSUES. WILL HOLD TIGHT FOR THE MORNING UPDATE...BUT WILL
HAVE TO TAKE A GOOD HARD LOOK FOR THE AFTERNOON PACKAGE.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY/...
TEMPERATURES ALREADY MAINLY ABOVE FREEZING TO START THE
PERIOD...EXCEPT FOR VERY NW CWA IN PERRY AND MORGAN COUNTY. SO
LINGER WINTER WEATHER ADVISORY THERE UNTIL 9AM FOR FREEZING
RAIN...POSSIBLY MIXED WITH SOME SLEET/SNOW. HAVE HIGH POPS AT THE
START OF THE PERIOD...AS COLD FRONT BEGINS MOVING THROUGH. THAT
FRONT WILL CROSS CWA MONDAY WITH MAINLY RAIN. AS THE COLD AIR WORKS
IN LATER MONDAY AND MONDAY NIGHT...EXPECT A TRANSITION FROM RAIN TO
SLEET TO SNOW. MOISTURE ALREADY BECOMING FAIRLY LIMITED BY THE TIME
COLD ENOUGH AIR WORKS IN FOR SNOW...SO ONLY HAVE LIGHT ACCUMULATIONS
AND MAINLY IN THE NORTHERN MOUNTAINOUS COUNTIES.
A WAVE RIDES UP THE FRONT TUESDAY...SO HANG ONTO POPS ACROSS THE
EAST INTO TUESDAY NIGHT...THEN GRADUALLY DECREASE. DO HAVE HIGHER
POPS FOR THIS THAN PREVIOUS FORECAST...BUT STILL ONLY GETTING UP TO
AROUND A 40 PERCENT CHANCE AS THE MAIN ACTIVITY LOOKS TO STAY SE OF
CWA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
COLDER AIR SWEEPS IN FOR A SEASONABLY COOL EXTENDED. AFTER THE
SYSTEM MONDAY/EARLY TUESDAY...APPEARS A MAINLY DRY EXTENDED IS IN
THE CARDS. THE MODELS CONTINUE E WITH SYSTEM MIDWEEK. DID LEAVE SOME
SMALL POPS ACROSS E HALF OF CWA FOR MIDWEEK AS THIS SYSTEM MAY TREND
A BIT W WITH TIME.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
CLOUDS WILL GRADUALLY BE LOWERING WITH PRECIPITATION MOVING IN
TONIGHT. THE PRECIPITATION WILL BE RAIN FOR MOST OF THE REGION...BUT
SOME SLEET OR FREEZING RAIN IS POSSIBLE IN THE SOUTHEAST UPSLOPE
AREAS OF POCAHONTAS COUNTY...AND CENTRAL OHIO AND EXTREME
NORTHWESTERN WV. A COLD FRONT WILL PUSH THROUGH ON MONDAY...WITH
MORE RESTRICTIONS IN CEILINGS AND PRECIPITATION POSSIBLE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: HIGH THIS AFTERNOON...THEN MEDIUM.
ALTERNATE SCENARIO: TIMING OF LOWERING CEILINGS AND VISIBILITY
RESTRICTIONS COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H M
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
IFR POSSIBLE MONDAY AFTERNOON...AND IN THE MOUNTAINS AND SOUTHERN
COUNTIES MONDAY NIGHT AND TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR WVZ009>011.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM EST
MONDAY FOR OHZ066-067.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR OHZ075-076-083>085.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...RPY
SHORT TERM...MZ
LONG TERM...30
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1020 AM EST SUN JAN 11 2015
.SYNOPSIS...
SOUTHERLY FLOW WILL DRAW MILDER AIR INTO THE OHIO VALLEY TODAY...
ALONG WITH INCREASING MOISTURE. THIS WILL SET THE STAGE FOR A THE
DEVELOPMENT OF A MIX OF SNOW...SLEET...AND FREEZING RAIN ACROSS
THE AREA THIS AFTERNOON INTO MONDAY. DRY CONDITIONS WILL RETURN
MONDAY NIGHT AS HIGH PRESSURE BUILDS OVER THE GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
ADDITIONAL UNCERTAINTY NOW WITH WARMER MODEL SOLUTIONS...CREATING
THE GREATER LIGHT ICE ACCUMULATION THREAT A LITTLE FURTHER NORTH
FROM CONNERSVILLE/RICHMOND THROUGH DAYTON AND NORTHEAST TO
DELAWARE OHIO. THIS AREA WILL ALSO MIX WITH SOME SLEET AND SNOW.
WHILE COBB SOLUTION FROM HRRR AND RAP DO HAVE THE CVG/ILN TEMPERATURE
PROFILE WITH PRECIPITATION TYPE AS MOSTLY RAIN...THE BIG CAVEAT
HERE IS ROAD SURFACE TEMPERATURES STILL 25 TO 29 DEGREES. DESPITE
AIR TEMPS RISING ABOVE FREEZING IN THIS AREA...THE CURRENT
THINKING IS THAT CLOUDS TODAY WILL NOT ALLOW ROAD SURFACE
TEMPERATURES TO RISE ABOVE FREEZING SO SEEMINGLY WET SURFACES WILL
BECOME GLAZED WITH ICE.
TEMPERATURES TODAY EVEN ARE TRICKY...WITH HIGH RESOLUTION MODELS
INDICATING BIG WARMUP AT PORTSMOUTH TO ABOVE 40 FOR HIGHS...BUT VERY
SLOW WARMUP SO FAR SO KEEPING WITH THE UPPER 30S. NEAR 30 FOR MOST
OTHER LOCATIONS...AND MID 30S NEAR/SOUTH OF OHIO RIVER.
PREVIOUS DISCUSSION FOLLOWS...
MID LEVEL FLOW BACKS SW AHEAD OF SRN SHORTWAVE TROF WHICH
EJECTS NE INTO OHIO VALLEY TONIGHT. THIS S/W PHASES WITH THE NRN
STREAM AND DAMPENS OUT AHEAD OF NRN STREAM TROF WHICH DROPS SE
THRU THE GREAT LAKES TONIGHT INTO MONDAY. 45 KT 8H JET DEVELOPS
THIS AFTN AHEAD OF THE AFOREMENTIONED S/W. THIS WILL LEAD TO
FAVORABLE ISENTROPIC LIFT AND LOW LEVEL CONVERGENCE. NATIONAL
RADAR MOSAIC ALREADY SHOWS LEADING EDGE OF PRECIP SPREADING NORTH
FROM THE SRN PLAINS INTO THE LOWER MS VLY INTO FAR WESTERN TN/WRN
KY. SYNOPTIC MODELS HOLD OFF PRECIP UNTIL LATE THIS AFTN INTO THE
WESTERN HALF OF THE FA. HOWEVER...MESOSCALE MODELS SHOW AN AXIS
OF PRECIP THAT PIVOTS N PRIOR TO THE MAIN AREA FILLING IN. AIRMASS
IS VERY DRY...SO THIS INITIAL SHOT OF PRECIP WILL LIKELY AT LEAST
PARTIALLY EVAPORATE AND LEAD TO EVAPORATIVE COOLING. GIVEN HOW FAR
NORTH THE PRECIP ALREADY IS HAVE ONLY SLOWED ONSET VERY SLIGHTLY
TO ACCOUNT FOR THIS EVAPORATION...WITH POPS LKLY INTO THE WEST BY
EVENING.
MODEL SOLNS HAVE TRENDED WARMER AND CURRENT SFC TEMPERATURES ARE
RUNNING WARMER THAN GUIDANCE. NAM SOLN IS STRONGER WITH THE LLJ
AND THEREFORE IS WARMER AND HAS MORE QPF. WHILE THE GFS/ECMWF SOLNS
HAVE LESS QPF BUT ARE COOLER. HAVE USED A BLENDED APPROACH FOR SFC
TEMPERATURES AND TOP DOWN GFS SOLN TO PRODUCE PRECIPITATION TYPE.
THIS YIELDS SNOW MIXING WITH AND CHANGING TO FREEZING RAIN ACRS
ALL BUT THE SE WHERE RAIN WILL PREVAIL. THE FAR NW WILL LKLY REMAIN
MAINLY SNOW.
AGREE WITH LATEST PC PROBABILITY GRAPHICS WITH MAINLY SNOW ACRS
FAR NRN PORTIONS OF WEST CENTRAL OHIO WHERE 1 TO 3 INCHES STORM
TOTAL LKLY AND LOCALLY UP TO 4 INCHES POSSIBLE. THE BEST AREA FOR
ICE ACCUMULATION LOOKS TO OCCUR IN A BAND FROM NEAR RICHMOND TO
NORTH OF DAYTON TO NORTH OF COLUMBUS. (THE NORTHERN I-70
CORRIDOR). STORM TOTAL ICE TOTALS HERE LOOK TO BE ONE TO TWO
TENTHS OF AN INCH.
OVERNIGHT TEMPERATURES WILL NOT DROP OFF TOO MUCH WITH LOWS FROM
THE UPPER 20S NW TO THE MID 30S SE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
NRN STREAM TROF TO DROPS SE THRU THE GREAT LAKES MONDAY. ASSOCIATED
SFC FRONT TO SWEEP SE THRU ILN/S FA MONDAY MORNING. PRECIPITATION
WILL DECREASE DURING THE DAY AND TAPER OFF MONDAY EVENING. EXPECT
PRECIP TO CHANGE TO SNOW IN LOW LEVEL CAA BUT WITH DEEP MOISTURE SHIFTING
EAST DAYTIME SNOW WILL BE AN INCH OR LESS WITH THE HIGHEST TOTALS
OVER WEST CENTRAL OHIO. EXPECT NON-DIURNAL TEMPERATURES MONDAY
WITH EARLY HIGHS RANGING FROM NEAR 30 NW TO THE UPPER 30S SE.
IN LOW LEVEL CAA PATTERN READINGS TO BE 5 TO 10 DEGREES BELOW
NORMAL MONDAY NIGHT WITH LOWS FROM THE SINGLE DIGITS ACROSS NW
PORTIONS OF THE FA WHERE THERE WILL BE MORE SNOW ON THE GROUND TO
THE LOW 20S ACROSS THE FAR SOUTHERN PORTIONS OF THE FA.
SFC HIGH PRESSURE TO BUILD ACRS THE GREAT LAKES TUESDAY...OFFERING
DRY CONDITIONS AND TEMPERATURES 10 TO 13 DEGREES BELOW NORMAL.
HIGHS ARE EXPECTED TO RANGE FROM THE MID/UPR TEENS NW TO THE UPPER
20S SE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
CAA UNDER NE FLOW LINGERS INTO WED AND THEN MOSTLY QUIET EXTENDED
PERIOD AS OVERALL FLOW BECOMES MORE AMPLIFIED AHEAD OF THE WEST
COAST RIDGE. A WEAK SHORT WAVE PASSES THROUGH THE GREAT LAKES AT
THE SAME TIME THE SOUTHERN STREAM RAMPS UP A MORE PRONOUNCED
THROUGH TO PULL JUST OFF THE EAST COAST. AT THIS TIME...FORECAST
AREA APPEARS TO BE BETWEEN BOTH OF THESE SYSTEMS...WITH MORE
LIKELY AFFECTS TO COME FROM THE GREAT LAKES SHORT WAVE...SO HAVE
KEPT SMALL CHANCES OF SNOW SHOWERS ACROSS THE NORTH ON THURSDAY
NIGHT BUT OTHERWISE CONTINUED DRY. BOTH OPERATIONAL AND PARALLEL
GFS AND ECMWF HAVE THESE SYSTEMS IN RELATIVELY CLOSE AGREEMENT AND
THEN RIDGING AGAIN FOR THE WEEKEND.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BE MOVING EAST TODAY. TROUGH OF LOW PRESSURE
CARRYING MOISTURE OVER A COLD SURFACE LAYER WILL PRODUCE A WINTRY
MIX OF PRECIPITATION STARTING AROUND 22Z. NORTHERN TAF SITES DAY
CMH AND LCK SHOULD SEE MAINLY SN AND PL TRANSITIONING TO
FZRAPL THEN BACK TO SNOW...WHILE FARTHER SOUTH AT CVG LUK AND
ILN...PRECIP SHOULD CHANGE TO RAIN. MVFR CONDITIONS ARE EXPECTED
WITH THE PRECIP...DROPPING TO IFR AS THE BOUNDARY LAYER BECOMES
SATURATED TOWARD THE END OF THE FORECAST. WINDS ARE FORECAST TO
STAY OUT OF THE SOUTH UNDER 10 KNOTS...SHIFTING TO SOUTHWEST LATE.
AS THE SYSTEM MOVES EAST ON MONDAY...WIND WILL SHIFT TO NORTHWEST
AT CVG IN VCSH.
OUTLOOK...MVFR CEILINGS MAY LINGER INTO MONDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 4 PM EST MONDAY FOR OHZ026-034-
035-042>046-051>056-060>065-070>072-077.
FREEZING RAIN ADVISORY UNTIL 10 AM EST MONDAY FOR OHZ073-074-
078>080.
KY...FREEZING RAIN ADVISORY UNTIL 10 AM EST MONDAY FOR KYZ089>093.
IN...WINTER WEATHER ADVISORY UNTIL 4 PM EST MONDAY FOR INZ050-058-
059-066-073-074.
FREEZING RAIN ADVISORY UNTIL 10 AM EST MONDAY FOR INZ075-080.
&&
$$
SYNOPSIS...AR
NEAR TERM...JDR
SHORT TERM...AR
LONG TERM...JDR
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
953 AM EST SUN JAN 11 2015
.SYNOPSIS...
MOISTURE/CLOUDS INCREASES TODAY...BUT NOT QUITE AS COLD IN AFTERNOON.
COLD FRONT SAGS SOUTH MONDAY. WEAK WAVE OF LOW PRESSURE SOUTH
POSSIBLE MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
BASED ON LATEST MODELS AND SATELLITE TRENDS...WILL INCREASE CLOUD
COVER FOR THIS AFTERNOON.
AM A BIT CONCERNED WITH THE MODEL TRENDS OF GETTING WARMER FOR THIS
AFTERNOON AND TONIGHT IN SOUTHEAST OHIO. MET/MAV AND LAV GUIDANCE
ARE MUCH WARMER THAN FORECAST...BUT THE HRRR STILL SHOWS WET BULBING
CAUSING ISSUES. WILL HOLD TIGHT FOR THE MORNING UPDATE...BUT WILL
HAVE TO TAKE A GOOD HARD LOOK FOR THE AFTERNOON PACKAGE.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY/...
TEMPERATURES ALREADY MAINLY ABOVE FREEZING TO START THE
PERIOD...EXCEPT FOR VERY NW CWA IN PERRY AND MORGAN COUNTY. SO
LINGER WINTER WEATHER ADVISORY THERE UNTIL 9AM FOR FREEZING
RAIN...POSSIBLY MIXED WITH SOME SLEET/SNOW. HAVE HIGH POPS AT THE
START OF THE PERIOD...AS COLD FRONT BEGINS MOVING THROUGH. THAT
FRONT WILL CROSS CWA MONDAY WITH MAINLY RAIN. AS THE COLD AIR WORKS
IN LATER MONDAY AND MONDAY NIGHT...EXPECT A TRANSITION FROM RAIN TO
SLEET TO SNOW. MOISTURE ALREADY BECOMING FAIRLY LIMITED BY THE TIME
COLD ENOUGH AIR WORKS IN FOR SNOW...SO ONLY HAVE LIGHT ACCUMULATIONS
AND MAINLY IN THE NORTHERN MOUNTAINOUS COUNTIES.
A WAVE RIDES UP THE FRONT TUESDAY...SO HANG ONTO POPS ACROSS THE
EAST INTO TUESDAY NIGHT...THEN GRADUALLY DECREASE. DO HAVE HIGHER
POPS FOR THIS THAN PREVIOUS FORECAST...BUT STILL ONLY GETTING UP TO
AROUND A 40 PERCENT CHANCE AS THE MAIN ACTIVITY LOOKS TO STAY SE OF
CWA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
COLDER AIR SWEEPS IN FOR A SEASONABLY COOL EXTENDED. AFTER THE
SYSTEM MONDAY/EARLY TUESDAY...APPEARS A MAINLY DRY EXTENDED IS IN
THE CARDS. THE MODELS CONTINUE E WITH SYSTEM MIDWEEK. DID LEAVE SOME
SMALL POPS ACROSS E HALF OF CWA FOR MIDWEEK AS THIS SYSTEM MAY TREND
A BIT W WITH TIME.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT 10Z...STILL LIKE OUR 06Z TRENDS OF BRINGING THE CLOUD DECK AT 7
TO 8 THSD FT NE INTO CWA FASTER. HAVE THE POTENTIAL OF SOME SLEET OR
FLAKES IN SE OHIO THIS AFTERNOON...BUT POPS ONLY IN CHANCE RANGE.
AS POPS INCREASE THIS EVENING...MILDER AIR ALOFT. HAVE SOME
FREEZING RAIN POSSIBLE AS FAR SOUTH AS JUST NORTH OF HTS IN
SOUTHEAST OHIO AND INTO THE PKB VCNTY...WITH HIGHER RISK OF FREEZING
RAIN IN INTERIOR SECTIONS OF SE OHIO.
CONDITIONS DETERIORATING WITH WIDESPREAD MVFR CEILING AND VSBY
DEVELOPING 03Z TO 06Z. MOSTLY RAIN HTS-CRW-BKW ON SOUTH...WITH RAIN
AND POCKETS OF FREEZING RAIN ALONG THE UNI-PKB-CKB-EKN CORRIDOR.
CEILINGS BECOMING 2 TO 3 THSD FT AND VSBY 3 TO 5 MILES 03Z TO 06Z.
BY 12Z MONDAY...FREEZING RAIN LESS WIDESPREAD WITH MOSTLY LIGHT RAIN.
AS COLUMN CONTINUES TO SATURATE...CONFIDENCE LOWERED TO MEDIUM...NOT
SURE HOW LOW THE CEILINGS WILL GO BETWEEN 06Z AND 12Z ESPECIALLY IN
SE OHIO AND ALSO OVER THE MOUNTAIN COUNTIES OF WV.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: SOME RENEGADE INITIAL PCPN MAY REACH THE GROUND
IN THE OHIO VALLEY IN THE FORM OF SOME SLEET PELLETS OR FLAKES 18Z
TODAY TO 00Z MONDAY...DROPPING VSBY BRIEFLY LOWER.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z MONDAY...
IFR POSSIBLE MONDAY...AND MOUNTAINS AND SOUTHERN COUNTIES MONDAY
NIGHT AND TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR WVZ009>011.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM EST
MONDAY FOR OHZ066-067.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR OHZ075-076-083>085.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...RPY
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS TULSA OK
1128 PM CST SAT JAN 10 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
MVFR TO VFR CONDITIONS ARE CURRENTLY FOUND ACROSS EASTERN
OKLAHOMA AND WESTERN ARKANSAS. CONDITIONS WILL CONTINUE TO
DETERIORATE OVERNIGHT INTO SUNDAY...ESPECIALLY ACROSS SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS WHERE IFR CONDITIONS WILL BECOME
MORE COMMON.
&&
.PREV DISCUSSION... /ISSUED 934 PM CST SAT JAN 10 2015/
..UPDATE...
DISCUSSION...
UPPER WAVE CURRENTLY OVER FAR WEST TX WILL LIFT NORTHEASTWARD
ACROSS THE LOCAL REGION DURING THE DAY ON SUNDAY. PRECIPITATION
HAS BEGUN TO EXPAND ACROSS SOUTH CENTRAL TX AND THIS WILL SPREAD
NORTHEASTWARD OVERNIGHT AND THROUGH THE DAY ON SUNDAY. CURRENTLY
LOW LEVEL CONDITIONS REMAIN VERY DRY ACROSS THE AREA BUT WILL
MOISTEN AS PRECIPITATION INTENSITY INCREASES OVERNIGHT. SFC TEMPS
REMAIN THE LARGEST VARIABLE CONCERNING PRECIPITATION TYPE AS A
STOUT WARM LAYER ALOFT WILL ENSURE COMPLETE MELTING OF DROPLETS.
INITIAL PRECIP WILL LIKELY RESULT IN A BRIEF PERIOD OF WET BULB
COOLING HOWEVER SUSTAINED WARM ADVECTION ALONG WITH FURTHER
WARMING POTENTIAL WITHIN HEAVIER PRECIP BANDS SUGGESTS ANY COOLING
WILL BE BRIEF. THIS ALIGNS WILL ALL AVAILABLE HOURLY GUIDANCE SFC
TRENDS AND W/ THE EARLIER FORECAST THOUGHTS. THE END RESULT IS A
FZRA / RA MIX W/ LIMITED POTENTIAL FOR ICE ACCUMULATIONS. ELEVATED
SFCS AND THE MORE SHELTERED VALLEYS OF NW AR AND FAR SE OK WILL BE
MOST PRONE TO MEASURABLE ICE ACCUMULATIONS...AND EVEN THEN THE
AMOUNTS ARE EXPECTED TO REMAIN LIGHT.
THE UPDATED FORECAST WILL EXPAND HIGH PRECIP CHANCES ACROSS SE OK
PER CONSISTENT TRENDS IN HRRR DATA. OTHERWISE THE FORECAST IS
TRACKING WELL WITH MINIMAL ADJUSTMENTS NEEDED.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL NOON SUNDAY FOR OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL NOON SUNDAY FOR ARZ002-ARZ011-
ARZ019-ARZ020-ARZ029.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
854 PM EST MON JAN 12 2015
.SYNOPSIS...
A LARGE HIGH PRESSURE SYSTEM WILL BUILD SOUTHEAST INTO PENNSYLVANIA
EARLY TUESDAY AND REMAIN OVER THE REGION THROUGH THE END OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE LAST OF THE RAIN IS EXITING THE LOWER SUSQ VALLEY AS OF
01Z...AS COLD FRONT PUSHES SOUTHEAST OF THE REGION. RADAR TRENDS
AND LATEST HRRR INDICATE THE PRECIP WILL END OVR LANCASTER CO ARND
03Z. SOME LINGERING OROGRAPHIC FLURRIES SHOULD PERSIST LATE INTO
THE NIGHT OVR THE NW MTNS/LAUREL HIGHLANDS. HOWEVER...EVEN THESE
SHOULD END TOWARD DAWN...AS SFC HIGH AND ASSOC LOW PWAT AIR MASS
ARRIVES.
ARRIVAL OF DRIER AIR WILL BRING CLEARING SKIES AFTER MIDNIGHT.
HOWEVER...MOISTURE TRAPPED BELOW INVERSION WILL PRODUCE
PERSISTENT STRATO-CU ACROSS THE ALLEGHENY PLATEAU. LOW TEMPS WILL
TUMBLE SOME 15-20F FROM TODAY`S HIGHS TO BOTTOM OUT IN THE SINGLE
DIGITS NORTH...TO ARND 20F IN THE SOUTHEAST...SOME 10-15 DEG BELOW
NORMAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
DESPITE ABUNDANT SUNSHINE...TEMPS WILL NOT RISE MUCH TUESDAY. THIS
AIR MASS PRODUCED HIGH TEMPS OVR WISCONSIN TODAY BTWN 5-15F AND
ALTHOUGH IT WILL MODIFY A BIT...GEFS MEAN 925MB TEMPS ONLY SUPPORT
MAX TEMPS FROM THE LOWER TEENS OVER THE N MTNS...TO THE M20S
ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
A BROADENING LONGWAVE TROF OVER THE EASTERN HALF OF THE CONUS WILL
LEAD TO COLD AND GENERALLY DRY WEATHER ACROSS THE REGION THROUGH
THE PERIOD. HIGH PRESSURE WILL BUILD OVER THE AREA TUESDAY
NIGHT...ALLOWING FOR CLEARING SKIES AND CALM WINDS. THIS SHOULD
ALLOW LOWS TO DROP CONSIDERABLY BY WEDNESDAY MORNING. HAVE DROPPED
TEMPS LOWER THAN GUIDANCE ACCORDINGLY. THE PATTERN THROUGH THE
WEEK SHOULD SEE SEVERAL WEAK AND MAINLY DRY SHORTWAVES IN THE NRN
STREAM THAT COULD BRING A SLIGHT CHANCE OF LIGHT PCPN...MAINLY
FRIDAY AFTN IN THE NW MTNS...AND LATE THIS UPCOMING WEEKEND.
CONSIDERING THE PHASE SHIFT AND INCONSISTENCIES OF THE
ENSEMBLES...HAVE LEFT ONLY CHANCE POPS. TEMPS SHOULD SEE A GENERAL
RISE AS THE WEEK CONTINUES INTO THE WEEKEND...WITH HIGHS IN THE
40S ALONG THE SOUTHERN TIER POSSIBLE BY LATE IN THE WEEKEND.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
STILL SOME LIGHT RAIN ACROSS THE SE. THIS SHOULD BE GONE
BY MIDNIGHT.
A LITTLE LIGHT SNOW AT JST.
RADAR RETURN JUST MOVED SOUTH OF THE OFFICE...MOST LIKELY
THE LEADING EDGE OF THE COOLER AIR.
EXPECT COLDER AIR AND GUSTY WINDS TO PICK UP FROM NW TO
SE OVERNIGHT.
LOW CIGS SHOULD SLOWLY THIN OUT LATE TONIGHT AND EARLY
TUE. BREEZY ON TUE...AS HIGH PRESSURE BUILDS TOWARD THE
AREA.
AFTER THIS...LOOKING AT VFR CONDITIONS LATER TUE INTO THE
END OF THE WEEK...AS HIGH PRESSURE BUILDS IN.
VERY DRY AIR LOW LEVELS WILL ALLOW WIDE LARGE SWING IN MAX
AND MIN TEMPS. WITH TENDENCY FOR A STRONG INVERSION EACH
NIGHT...WILL HAVE TO WATCH FOR THE POTENTIAL FOR A COMBINATION
OF ICE FOG...HZ...AND SMOKE TO FORM EACH MORNING AFTER TUESDAY
MORNING...AS THE CENTER OF THE HIGH REMAINS NEARBY...AND A
STRONG INVERSION REMAINS ACROSS THE AREA.
ALSO SYSTEMS PASSING JUST SOUTH OF PA THIS WEEK...WILL NEED
TO WATCH THESE...IN CASE MODELS SHOW ANY TRENDS TO THE NORTH.
OUTLOOK...
WED-THU...LOW CIGS POSSIBLE SOUTH/SOUTHEAST WITH LOW LEVEL
MARITIME FLOW.
FRI-SAT...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/CERU
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
833 PM EST MON JAN 12 2015
.SYNOPSIS...
A LARGE HIGH PRESSURE SYSTEM WILL BUILD SOUTHEAST INTO PENNSYLVANIA
EARLY TUESDAY AND REMAIN OVER THE REGION THROUGH THE END OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE LAST OF THE RAIN IS EXITING THE LOWER SUSQ VALLEY AS OF
01Z...AS COLD FRONT PUSHES SOUTHEAST OF THE REGION. RADAR TRENDS
AND LATEST HRRR INDICATE THE PRECIP WILL END OVR LANCASTER CO ARND
03Z. SOME LINGERING OROGRAPHIC FLURRIES SHOULD PERSIST LATE INTO
THE NIGHT OVR THE NW MTNS/LAUREL HIGHLANDS. HOWEVER...EVEN THESE
SHOULD END TOWARD DAWN...AS SFC HIGH AND ASSOC LOW PWAT AIR MASS
ARRIVES.
ARRIVAL OF DRIER AIR WILL BRING CLEARING SKIES AFTER MIDNIGHT.
HOWEVER...MOISTURE TRAPPED BELOW INVERSION WILL PRODUCE
PERSISTENT STRATO-CU ACROSS THE ALLEGHENY PLATEAU. LOW TEMPS WILL
TUMBLE SOME 15-20F FROM TODAY`S HIGHS TO BOTTOM OUT IN THE SINGLE
DIGITS NORTH...TO ARND 20F IN THE SOUTHEAST...SOME 10-15 DEG BELOW
NORMAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
DESPITE ABUNDANT SUNSHINE...TEMPS WILL NOT RISE MUCH TUESDAY. THIS
AIR MASS PRODUCED HIGH TEMPS OVR WISCONSIN TODAY BTWN 5-15F AND
ALTHOUGH IT WILL MODIFY A BIT...GEFS MEAN 925MB TEMPS ONLY SUPPORT
MAX TEMPS FROM THE LOWER TEENS OVER THE N MTNS...TO THE M20S
ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
A BROADENING LONGWAVE TROF OVER THE EASTERN HALF OF THE CONUS WILL
LEAD TO COLD AND GENERALLY DRY WEATHER ACROSS THE REGION THROUGH
THE PERIOD. HIGH PRESSURE WILL BUILD OVER THE AREA TUESDAY
NIGHT...ALLOWING FOR CLEARING SKIES AND CALM WINDS. THIS SHOULD
ALLOW LOWS TO DROP CONSIDERABLY BY WEDNESDAY MORNING. HAVE DROPPED
TEMPS LOWER THAN GUIDANCE ACCORDINGLY. THE PATTERN THROUGH THE
WEEK SHOULD SEE SEVERAL WEAK AND MAINLY DRY SHORTWAVES IN THE NRN
STREAM THAT COULD BRING A SLIGHT CHANCE OF LIGHT PCPN...MAINLY
FRIDAY AFTN IN THE NW MTNS...AND LATE THIS UPCOMING WEEKEND.
CONSIDERING THE PHASE SHIFT AND INCONSISTENCIES OF THE
ENSEMBLES...HAVE LEFT ONLY CHANCE POPS. TEMPS SHOULD SEE A GENERAL
RISE AS THE WEEK CONTINUES INTO THE WEEKEND...WITH HIGHS IN THE
40S ALONG THE SOUTHERN TIER POSSIBLE BY LATE IN THE WEEKEND.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
STILL SOME PRECIPITATION TO THE SW...MINOR ADJUSTMENTS MADE
TO THE 21Z TAFS.
EARLIER DISCUSSION BELOW.
WIDESPREAD IFR/MVFR WILL CONTINUE THROUGH THE DAY ALONG WITH
SPOTTY LIGHT PRECIPITATION THAT WILL GRADUALLY DECREASE IN
COVERAGE TOWARD EVENING.
A COLD FRONTAL PASSAGE THIS AFTERNOON WILL BE MARKED BY A WIND
SHIFT TO THE NW AND ANY KIND OF RAIN OR FREEZING RAIN TURNING
BACK TO SNOW SHOWERS AS THE PRECIPITATION WINDS DOWN OVERALL.
EXPECT PCPN TO SHUT OFF ACROSS MOST OF THE AIRSPACE BY MIDNIGHT
WITH SOME LIGHT SNOW SHOWERS POSSIBLY LINGERING OVER THE WESTERN
AND NORTHERN HIGHER ELEVATIONS.
FLYING CONDITIONS SHOULD RETURN TO VFR ON TUESDAY AS HIGH
PRESSURE SHIFTS EAST FROM THE GREAT LAKES INTO THE NORTHEAST.
OUTLOOK...
WED-THU...LOW CIGS POSSIBLE SOUTH/SOUTHEAST WITH LOW LEVEL MARITIME
FLOW.
FRI-SAT...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/CERU
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1133 PM CST SAT JAN 10 2015
.UPDATE...
ISSUED AT 933 PM CST SAT JAN 10 2015
TEMPERATURES HAVE BEEN PROBLEMATIC THIS EVENING AS THEY HAVE
ACTUALLY RISEN THROUGH THE EVENING AHEAD OF A WEAK COLD FRONT
TRACKING EAST THROUGH NORTH CENTRAL WISCONSIN ON DOWN TO CENTRAL
IOWA. TEMPS ARE IN THE UPPER TEENS TO LOW 20S AHEAD OF THE FRONT
WHERE SOME 3-5KFT STRATUS IS HELPING TO KEEP THOSE TEMPERATURES
UP. SKIES CLEAR OUT ONCE THE FRONT COMES THROUGH AND THE
TEMPERATURES DROP INTO THE SINGLE DIGITS. 11.02Z RAP LOW LEVEL
MOISTURE FIELDS SHOW THIS AREA OF LOWER CLOUDS SHIFTING EAST OF
THE AREA SHORTLY AFTER MIDNIGHT. SO...LOW TEMPERATURES STILL
SHOULD BE HIT OVERNIGHT...IT JUST MAY TAKE A LITTLE LONGER TO GET
DOWN THERE.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 209 PM CST SAT JAN 10 2015
NORTHWEST FLOW ALOFT CONTINUES ACROSS THE REGION PER LATEST WATER
VAPOR/500 MB RAP ANALYSIS. A WEAK MID-LEVEL WAVE/SURFACE TROUGH
WITHIN THIS FLOW WAS DROPPING INTO THE DAKOTAS/MN THIS AFTERNOON
WITH DECENT WING OF 285-290K ISENTROPIC LIFT/WAA OUT AHEAD OF IT
INTO OUR AREA. THIS HAS RESULTED IN WIDESPREAD EXPANSION OF
ALTOCUMULUS/STRATOCUMULUS THROUGH THE DAY. NO SNOW FLURRY ACTIVITY
YET PER SURFACE OBSERVATIONS...BUT RADAR PICKING UP ON VIRGA AROUND
3KFT...SO EXPECTING AT LEAST A FEW FLURRIES GOING THROUGH THE REST
OF THIS AFTERNOON. OTHERWISE...TEMPERATURES ACROSS THE AREA THIS
AFTERNOON WERE IN THE SINGLE DIGITS/TEENS ABOVE ZERO.
LOOK FOR THE MID-LEVEL WAVE/SURFACE TROUGH TO CONTINUE SLIPPING
SOUTHEAST INTO THE REGION THIS EVENING...AND THEN EAST OF THE AREA
AROUND MIDNIGHT. WILL KEEP MENTION OF FLURRIES IN THROUGH THE
EVENING HOURS...MAINLY NORTHEAST OF I-94 BUT THEN DROPPED THEM AFTER
MIDNIGHT WITH FORCING EXITING THE AREA. OTHERWISE...LOOKS LIKE
SUBSTANTIAL MID-LEVEL CLOUD COVER WILL LINGER THROUGH THE OVERNIGHT
HOURS. AS A RESULT...TEMPERATURES ONLY EXPECTED TO DROP INTO THE
SINGLE DIGITS BELOW TO NEAR 10 ABOVE.
FOR SUNDAY AFTERNOON/EVENING...LOOKING AT ANOTHER WEAK MID-LEVEL
TROUGH DROPPING ACROSS THE REGION. NAM INDICATING DECENT AMOUNT OF
850-500MB FRONTOGENESIS WITH THE TROUGH AS IT DROPS SOUTHEAST ACROSS
THE AREA. BASED ON THIS SIGNAL...ADDED MENTION OF FLURRIES AS NAM
BUFKIT SOUNDINGS SHOWING ALMOST TOTAL COLUMN SATURATION. PLAN ON
HIGHS MOSTLY IN THE TEENS...WITH A FEW LOWER 20S ACROSS NORTHEAST IA
INTO FAR SOUTHWEST WI. NORTHWEST WINDS AND A PUSH OF ARCTIC AIR
OVERSPREAD THE AREA OVERNIGHT WITH LOWS DIPPING DOWN INTO THE SINGLE
DIGITS ABOVE AND BELOW ZERO. COMBINED WITH NORTHWEST WINDS AROUND 10
MPH...LOOKING FOR WIND CHILL VALUES IN THE TEENS TO NEAR 20 BELOW
ACROSS PARTS OF SOUTHEAST MN INTO NORTH CENTRAL WI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 209 PM CST SAT JAN 10 2015
COLD START TO THE NEW WORK WEEK AS MODIFIED ARCTIC AIRMASS MOVES
ACROSS THE REGION. PLAN ON HIGHS MONDAY AND TUESDAY IN THE SINGLE
DIGITS/TEENS ABOVE ZERO WITH LOWS MONDAY NIGHT IN THE SINGLE DIGITS
ABOVE AND BELOW ZERO.
LOOKING AT A SLOW WARMING TREND THEN FOR WEDNESDAY THROUGH SATURDAY
AS FLOW ACROSS THE CONUS BECOMES MORE HIGH ZONAL. THIS WILL TAP MORE
PACIFIC ORIGIN AIR INTO THE REGION WITH ARCTIC AIR RETREATING BACK
NORTH OF THE CANADIAN BORDER. MODEL CONSENSUS PRODUCES HIGH
TEMPERATURES WEDNESDAY IN THE TEENS TO LOWER 20S...THEN MODERATING
INTO THE UPPER 20S TO LOWER 30S BY FRIDAY AND SATURDAY. INCREASE IN
MID-LEVEL HEIGHTS/RIDGING KEEPS ANY WEATHER WELL NORTH OF THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1133 PM CST SAT JAN 10 2015
THE MVFR STRATUS DECK HAS SHIFTED OFF TO THE EAST OF LSE/RST WITH
SOME HIGH LEVEL CLOUDS MOVING IN FROM UPSTREAM. WINDS WILL REMAIN
ON THE LIGHT SIDE ON SUNDAY AS THE COLD FRONT STALLS OUT AND
DRIFTS EAST THROUGH THE DAY. THERE IS A FEATURE THAT APPEARS TO
MOVE IN TOMORROW EVENING WHICH COULD PRODUCE A VERY SHORT PERIOD
OF LIGHT SNOW. THE LOW LEVELS MAY BE TOO DRY FOR THIS SNOW TO
REACH THE GROUND...SO FOR NOW HAVE JUST ADDED A P6SM -SN TO THE
TAFS TOMORROW EVENING FOR WHEN IT LOOKS LIKE IT WILL SWING
THROUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM....DAS
LONG TERM.....DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1035 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1015 AM MST SUN JAN 11 2015
ANOTHER INTERESTING AND CHALLENGING AFTERNOON FORECAST TODAY WITH
THE MODIFIED ARCTIC AIR INTRUSION ALONG WITH SNOW CHANCES.
WATCHING THE COLD AIR ADVECTION ACROSS NORTHEAST WYOMING AND
WESTERN SOUTH DAKOTA...AND OUR CURRENT TEMPERATURE TRENDS...
HAVE MODIFIED OUR MAXIMUM TEMPERATURES SLIGHTLY...AS WELL AS
MASSAGED THE GRIDDED FORECASTS TO SHOW FALLING TEMPERATURES BY
SUPPER TIME AS THE NAM TEMPS HAVE A DECENT HANDLE ON THIS.
WEAK SHORTWAVE TROUGH ALOFT AND DECENT UPWARD VERTICAL MOTION
MOVE ACROSS OUR COUNTIES THIS AFTERNOON WITH MESOSCALE LIFT AND
UPSLOPE LIFT ALONG AND EAST OF THE MOUNTAINS AIDING IN INCREASING
AREAL COVERAGE OF SNOW...SO HAVE ADJUSTED POPS TO ACCOUNT FOR
THIS...ESPECIALLY WITH THE 12Z NAM SHOWING OUR LOW AND MID LEVELS
SATURATING NICELY THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 320 AM MST SUN JAN 11 2015
CURRENT IR SATELLITE LOOP AND SURFACE OBS ACROSS THE REGION SHOW
YET ANOTHER REINFORCING SHOT OF COLD ARCTIC AIR ACROSS
MONTANA...PUSHING SOUTHWARD EARLY THIS MORNING. THE LEADING EDGE
OF THE FRONT APPEARS TO HAVE JUST PUSHED INTO NORTHERN
WYOMING...WITH WINDS SHIFTING INTO THE NORTH AT GILLETTE AND
SHERIDAN AND INCREASING BAROMETRIC PRESSURE. THANKFULLY...MODELS
SHOW THE BULK OF THE COLDEST AIR STAYING EAST OF THE REGION AS
SOUTHEAST WYOMING AND WESTERN NEBRASKA AS THE AREA GETS BRUSHED BY
THE ARCTIC DOME OVER THE DAKOTAS BY THIS TIME TOMORROW MORNING.
HOWEVER...WE EXPECT MORE SNOWFALL IN THIS EVENT COMPARED TO THE
PREVIOUS ARCTIC FRONTAL PASSAGES IN THE LAST WEEK AS FRONTOGENESIS
COMBINES WITH UPSLOPE FLOW AND MID TO UPPER LEVEL DYNAMICS FROM A
SERIES OF UPPER LEVEL DISTURBANCES MOVING ACROSS THE GREAT BASIN
REGION AND INTO THE CENTRAL ROCKY MOUNTAINS THROUGH LATE MONDAY
NIGHT.
THE ARCTIC FRONT AND ASSOCIATED COLDER AIRMASS WILL BEGIN TO PUSH
INTO THE REGION LATE THIS MORNING...AND THEN ACROSS THE REST OF
THE HIGH PLAINS INTO COLORADO THROUGH THIS AFTERNOON. HIGH
TEMPERATURES WILL OCCUR SOMETIME THIS MORNING BEFORE TEMPERATURES
LOWER INTO THE TEENS AND 20S ACROSS THE HIGH PLAINS LATE THIS
AFTERNOON. THE FRONT WILL THEN STALL NEAR OR JUST WEST OF THE
LARAMIE RANGE...CREATING A NATURAL CONVERGENCE BOUNDARY WITH EAST
TO SOUTHEAST WINDS ACROSS THE HIGH PLAINS AND WEST TO SOUTHWEST
WINDS WEST OF THE FRONT. IN ADDITION...SOME WARM AIR ADVECTION
ALOFT AROUND 700MB IS EXPECTED AHEAD OF EACH UPPER LEVEL
DISTURBANCE AS THEY MOVE TOWARDS THE FORECAST AREA. THIS WILL
CREATE LIFT AND WILL ACT LIKE A WARM FRONTAL BOUNDARY WITH
RELATIVELY WARM AND MOIST AIR OVERRUNNING COLD AIR NEAR THE
SURFACE. EXPECT A HIGH POP/LOW QPF EVENT BEGINNING LATE TODAY
THROUGH TONIGHT. SNOWFALL WILL REMAIN NEAR THE MOUNTAINS THROUGH
MOST OF TODAY...BUT WHEN THE ARCTIC FRONT MOVES SOUTH AND WEST
ACROSS THE AREA...SNOWFALL WILL THEN DEVELOP FURTHER EAST ACROSS
EXTREME SOUTHEAST WYOMING AND WESTERN NEBRASKA. MAINLY EXPECT
LIGHT SNOW INTENSITY...WITH PERHAPS SOME BANDS OF MODERATE SNOW
ALONG THE LARAMIE RANGE AND IN THE MOUNTAINS. 3 TO 6 INCHES OF
SNOW APPEARS TO BE A GOOD BET FOR THE MOUNTAINS THROUGH
TONIGHT...WITH 1 TO 3 INCHES FOR THE HIGH VALLEYS AND HIGH PLAINS.
PRETTY SURE A FEW LOCATIONS OUTSIDE THE MOUNTAINS WILL RECEIVE 4
OR 5 INCHES...BUT THESE WILL BE TOO ISOLATED AND DIFFICULT TO PIN
DOWN FOR A WINTER WEATHER ADVISORY AT THIS TIME. WITH WINDS
SHIFTING INTO THE SOUTH BY EARLY MONDAY MORNING...THE POTENTIAL
FOR DENSE FOG IS HIGH OVER THE CHEYENNE RIDGE AND SOUTHERN LARAMIE
RANGE DUE TO UPSLOPE FLOW FROM THE OPPOSITE DIRECTION. THERE IS A
SMALL CHANCE AT SOME FREEZING DRIZZLE...BUT CURRENT MODEL
SOUNDINGS DO NOT SUPPORT A WIDESPREAD EVENT FOR MORE THAN AN HOUR
OR TWO.
EXPECT A BRIEF BREAK ON MONDAY AS THE LOW AND UPPER LEVELS DRY OUT
A BIT...BUT MAY STILL HAVE SOME LINGERING FOG WITH SOUTHERLY WINDS
THROUGH THE DAY ACROSS THE CHEYENNE RIDGE. MODELS THEN SHOW THE
THIRD UPPER LEVEL DISTURBANCE PUSHING ONSHORE AND DEVELOPING A
MORE POTENT UPPER LEVEL TROUGH ACROSS THE EASTERN GREAT BASIN
REGION. THIS SYSTEM WILL BRING A HIGHER CHANCE OF MODERATE TO
HEAVY SNOW TO THE WASATCH AND WEST OF THE CONTINENTAL DIVIDE.
MODELS HAVE CONTINUED TRENDING THIS SYSTEM SOUTH OF THE FORECAST
AREA...AS IT DIGS SOUTHEAST INTO THE FOUR CORNERS REGION AND
CONTINUES MOVING SOUTHEAST OR EAST. HOWEVER...WILL HAVE TO MONITOR
THE EVOLUTION OF THIS SYSTEM AS IT PUSHES ONSHORE SINCE THE 00Z
AND 06Z NAM SHOW THE TROUGH BECOMING A CLOSED LOW AS IT DRIFTS
EAST OVER COLORADO. THIS SOLUTION WOULD TYPICALLY RESULT IN MORE
SNOWFALL ACROSS SOUTHEAST WYOMING. KEPT POP FOR THE LOWER
ELEVATIONS OF SOUTHEAST WYOMING BETWEEN 15 TO 25 PERCENT FOR
NOW...WITH VALUES BELOW 10 PERCENT EAST OF I25. TEMPERATURES WILL
BE BELOW NORMAL FOR BOTH MONDAY AND TUESDAY...WITH HIGHS IN THE
20S TO LOW 30S...WARMEST WEST OF THE LARAMIE RANGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 219 AM MST SUN JAN 11 2015
00Z MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT WITH A MEAN RIDGE
WEST OF THE ROCKIES AND A TROUGH FROM THE GREAT PLAINS EASTWARD
MIDWEEK. THE RIDGE TRANSLATES EAST AND DEAMPLIFIES AS SHORTWAVE
ENERGY MOVES FROM THE PACIFIC NORTHWEST ACROSS ID/MT INTO WY/NE
THURSDAY THROUGH FRIDAY. NOT EXPECTING ANY PRECIPITATION AS MOISTURE
WILL BE LIMITED. WILL SEE AN INCREASE IN WESTERLY WINDS FRIDAY WITH
GUSTS OF 30 TO 40 KT POSSIBLE OVER THE NORTHERN LARAMIE RANGE. HIGH
TEMPERATURES WILL MODERATE FROM THE 20S AND 30S WEDNESDAY TO THE
30S AND 40S THURSDAY AND FRIDAY. THE MILD TEMPERATURES WILL LIKELY
PERSIST INTO NEXT WEEKEND AS A MORE ZONAL PATTERN ALOFT DEVELOPS
WITH BREEZY TO WINDY WESTERLY WINDS CONTINUING. THERE ARE INDICATIONS
THAT PACIFIC MOISTURE WILL SPREAD EAST INTO SOUTH CENTRAL WY SUNDAY
WITH LIGHT SNOW POSSIBLE ACROSS SOUTHERN CARBON COUNTY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 219 AM MST SUN JAN 11 2015
LATEST HRRR MODEL DATA DEPICTS VFR CONDITIONS PREVAILING EAST OF
THE LARAMIE RANGE THROUGH MIDDAY FOLLOWED BY DETERIORATING CIGS
AND VSBYS THIS AFTERNOON AS A COLD FRONT PUSHES SOUTH ACROSS THE
FORECAST AREA. WEST OF THE LARAMIE RANGE...MVFR TO IFR CONDITIONS
WILL DEVELOP IN LOW CIGS AND LIGHT SNOW. THE MOUNTAINS WILL BE
OBSCURED THROUGH THE PERIOD. WINDS WILL SHIFT FROM SOUTHWESTERLY
TO NORTHERLY WITH FROPA. SPEEDS WILL AVERAGE LESS THAN 15 KT.
&&
.FIRE WEATHER...
ISSUED AT 159 AM MST SUN JAN 11 2015
NO FIRE WEATHER CONCERNS THROUGH THE WEEK WITH COOL
TEMPERATURES...UNSETTLED CONDITIONS AT TIMES...AND HIGH HUMIDITIES
CONTINUING OVER THE AREA. A WARMING TREND IS EXPECTED BY LATE THIS
WEEK...BUT DAYTIME HUMIDITIES WILL REMAIN OVER 40 PERCENT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...TJT
LONG TERM...MJ
AVIATION...MJ
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
323 AM MST SUN JAN 11 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 320 AM MST SUN JAN 11 2015
CURRENT IR SATELLITE LOOP AND SURFACE OBS ACROSS THE REGION SHOW
YET ANOTHER REINFORCING SHOT OF COLD ARCTIC AIR ACROSS
MONTANA...PUSHING SOUTHWARD EARLY THIS MORNING. THE LEADING EDGE
OF THE FRONT APPEARS TO HAVE JUST PUSHED INTO NORTHERN
WYOMING...WITH WINDS SHIFTING INTO THE NORTH AT GILLETTE AND
SHERIDAN AND INCREASING BAROMETRIC PRESSURE. THANKFULLY...MODELS
SHOW THE BULK OF THE COLDEST AIR STAYING EAST OF THE REGION AS
SOUTHEAST WYOMING AND WESTERN NEBRASKA AS THE AREA GETS BRUSHED BY
THE ARCTIC DOME OVER THE DAKOTAS BY THIS TIME TOMORROW MORNING.
HOWEVER...WE EXPECT MORE SNOWFALL IN THIS EVENT COMPARED TO THE
PREVIOUS ARCTIC FRONTAL PASSAGES IN THE LAST WEEK AS FRONTOGENESIS
COMBINES WITH UPSLOPE FLOW AND MID TO UPPER LEVEL DYNAMICS FROM A
SERIES OF UPPER LEVEL DISTURBANCES MOVING ACROSS THE GREAT BASIN
REGION AND INTO THE CENTRAL ROCKY MOUNTAINS THROUGH LATE MONDAY
NIGHT.
THE ARCTIC FRONT AND ASSOCIATED COLDER AIRMASS WILL BEGIN TO PUSH
INTO THE REGION LATE THIS MORNING...AND THEN ACROSS THE REST OF
THE HIGH PLAINS INTO COLORADO THROUGH THIS AFTERNOON. HIGH
TEMPERATURES WILL OCCUR SOMETIME THIS MORNING BEFORE TEMPERATURES
LOWER INTO THE TEENS AND 20S ACROSS THE HIGH PLAINS LATE THIS
AFTERNOON. THE FRONT WILL THEN STALL NEAR OR JUST WEST OF THE
LARAMIE RANGE...CREATING A NATURAL CONVERGENCE BOUNDARY WITH EAST
TO SOUTHEAST WINDS ACROSS THE HIGH PLAINS AND WEST TO SOUTHWEST
WINDS WEST OF THE FRONT. IN ADDITION...SOME WARM AIR ADVECTION
ALOFT AROUND 700MB IS EXPECTED AHEAD OF EACH UPPER LEVEL
DISTURBANCE AS THEY MOVE TOWARDS THE FORECAST AREA. THIS WILL
CREATE LIFT AND WILL ACT LIKE A WARM FRONTAL BOUNDARY WITH
RELATIVELY WARM AND MOIST AIR OVERRUNNING COLD AIR NEAR THE
SURFACE. EXPECT A HIGH POP/LOW QPF EVENT BEGINNING LATE TODAY
THROUGH TONIGHT. SNOWFALL WILL REMAIN NEAR THE MOUNTAINS THROUGH
MOST OF TODAY...BUT WHEN THE ARCTIC FRONT MOVES SOUTH AND WEST
ACROSS THE AREA...SNOWFALL WILL THEN DEVELOP FURTHER EAST ACROSS
EXTREME SOUTHEAST WYOMING AND WESTERN NEBRASKA. MAINLY EXPECT
LIGHT SNOW INTENSITY...WITH PERHAPS SOME BANDS OF MODERATE SNOW
ALONG THE LARAMIE RANGE AND IN THE MOUNTAINS. 3 TO 6 INCHES OF
SNOW APPEARS TO BE A GOOD BET FOR THE MOUNTAINS THROUGH
TONIGHT...WITH 1 TO 3 INCHES FOR THE HIGH VALLEYS AND HIGH PLAINS.
PRETTY SURE A FEW LOCATIONS OUTSIDE THE MOUNTAINS WILL RECEIVE 4
OR 5 INCHES...BUT THESE WILL BE TOO ISOLATED AND DIFFICULT TO PIN
DOWN FOR A WINTER WEATHER ADVISORY AT THIS TIME. WITH WINDS
SHIFTING INTO THE SOUTH BY EARLY MONDAY MORNING...THE POTENTIAL
FOR DENSE FOG IS HIGH OVER THE CHEYENNE RIDGE AND SOUTHERN LARAMIE
RANGE DUE TO USPLOPE FLOW FROM THE OPPOSITE DIRECTION. THERE IS A
SMALL CHANCE AT SOME FREEZING DRIZZLE...BUT CURRENT MODEL
SOUNDINGS DO NOT SUPPORT A WIDESPREAD EVENT FOR MORE THAN AN HOUR
OR TWO.
EXPECT A BRIEF BREAK ON MONDAY AS THE LOW AND UPPER LEVELS DRY OUT
A BIT...BUT MAY STILL HAVE SOME LINGERING FOG WITH SOUTHERLY WINDS
THROUGH THE DAY ACROSS THE CHEYENNE RIDGE. MODELS THEN SHOW THE
THIRD UPPER LEVEL DISTURBANCE PUSHING ONSHORE AND DEVELOPING A
MORE POTENT UPPER LEVEL TROUGH ACROSS THE EASTERN GREAT BASIN
REGION. THIS SYSTEM WILL BRING A HIGHER CHANCE OF MODERATE TO
HEAVY SNOW TO THE WASATCH AND WEST OF THE CONTINENTAL DIVIDE.
MODELS HAVE CONTINUED TRENDING THIS SYSTEM SOUTH OF THE FORECAST
AREA...AS IT DIGS SOUTHEAST INTO THE FOUR CORNERS REGION AND
CONTINUES MOVING SOUTHEAST OR EAST. HOWEVER...WILL HAVE TO MONITOR
THE EVOLUTION OF THIS SYSTEM AS IT PUSHES ONSHORE SINCE THE 00Z
AND 06Z NAM SHOW THE TROUGH BECOMING A CLOSED LOW AS IT DRIFTS
EAST OVER COLORADO. THIS SOLUTION WOULD TYPICALLY RESULT IN MORE
SNOWFALL ACROSS SOUTHEAST WYOMING. KEPT POP FOR THE LOWER
ELEVATIONS OF SOUTHEAST WYOMING BETWEEN 15 TO 25 PERCENT FOR
NOW...WITH VALUES BELOW 10 PERCENT EAST OF I25. TEMPERATURES WILL
BE BELOW NORMAL FOR BOTH MONDAY AND TUESDAY...WITH HIGHS IN THE
20S TO LOW 30S...WARMEST WEST OF THE LARAMIE RANGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 219 AM MST SUN JAN 11 2015
00Z MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT WITH A MEAN RIDGE
WEST OF THE ROCKIES AND A TROUGH FROM THE GREAT PLAINS EASTWARD
MIDWEEK. THE RIDGE TRANSLATES EAST AND DEAMPLIFIES AS SHORTWAVE
ENERGY MOVES FROM THE PACIFIC NORTHWEST ACROSS ID/MT INTO WY/NE
THURSDAY THROUGH FRIDAY. NOT EXPECTING ANY PRECIPITATION AS MOISTURE
WILL BE LIMITED. WILL SEE AN INCREASE IN WESTERLY WINDS FRIDAY WITH
GUSTS OF 30 TO 40 KT POSSIBLE OVER THE NORTHERN LARAMIE RANGE. HIGH
TEMPERATURES WILL MODERATE FROM THE 20S AND 30S WEDNESDAY TO THE
30S AND 40S THURSDAY AND FRIDAY. THE MILD TEMPERATURES WILL LIKELY
PERSIST INTO NEXT WEEKEND AS A MORE ZONAL PATTERN ALOFT DEVELOPS
WITH BREEZY TO WINDY WESTERLY WINDS CONTINUING. THERE ARE INDICATIONS
THAT PACIFIC MOISTURE WILL SPREAD EAST INTO SOUTH CENTRAL WY SUNDAY
WITH LIGHT SNOW POSSIBLE ACROSS SOUTHERN CARBON COUNTY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 219 AM MST SUN JAN 11 2015
LATEST HRRR MODEL DATA DEPICTS VFR CONDITIONS PREVAILING EAST OF
THE LARAMIE RANGE THROUGH MIDDAY FOLLOWED BY DETERIORATING CIGS
AND VSBYS THIS AFTERNOON AS A COLD FRONT PUSHES SOUTH ACROSS THE
FORECAST AREA. WEST OF THE LARAMIE RANGE...MVFR TO IFR CONDITIONS
WILL DEVELOP IN LOW CIGS AND LIGHT SNOW. THE MOUNTAINS WILL BE
OBSCURED THROUGH THE PERIOD. WINDS WILL SHIFT FROM SOUTHWESTERLY
TO NORTHERLY WITH FROPA. SPEEDS WILL AVERAGE LESS THAN 15 KT.
&&
.FIRE WEATHER...
ISSUED AT 159 AM MST SUN JAN 11 2015
NO FIRE WEATHER CONCERNS THROUGH THE WEEK WITH COOL
TEMPERATURES...UNSETTLED CONDITIONS AT TIMES...AND HIGH HUMIDITIES
CONTINUING OVER THE AREA. A WARMING TREND IS EXPECTED BY LATE THIS
WEEK...BUT DAYTIME HUMIDITIES WILL REMAIN OVER 40 PERCENT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...TJT
LONG TERM...MJ
AVIATION...MJ
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1003 PM MST SAT JAN 10 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 136 PM MST SAT JAN 10 2015
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
SNOW POTENTIAL INCREASING ACROSS THE AREA THIS EVENING AND SUNDAY AS
THE UPPER LEVEL WAVE MOVES TOWARD THE REGION.
TONIGHT-SUNDAY:
LATEST WATER VAPOR LOOP WAS SHOWING THE VORT LOBE
MOVING THROUGH SOUTHEAST OREGON. THIS FEATURE IS EXPECTED IS TO
TRANSLATE EAST THROUGH THE REGION TONIGHT AND SUNDAY. LATEST IR
LOOP WAS ALREADY SHOWING THE MOISTURE INCREASING ACROSS UTAH AND
LIFTING NORTHEAST. AT THIS POINT...IT APPEARS LIKE THE BEST CHANCE
OF SNOW WILL BE ACROSS THE MOUNTAINS DUE TO GOOD OROGRAPHICS AND
WEAK MID LEVEL JET STREAK. MEANWHILE...A WEAK BOUNDARY CURRENTLY
MOVING THROUGH NORTHERN MONTANA WILL INTERACT WITH THIS WAVE
TOMORROW AFTERNOON IN THE EASTERN PLAINS. THERE MAY BE ENOUGH
CONDITIONAL INSTABILITY TO PRODUCE A FEW AFTERNOON SNOW SHOWERS.
HOWEVER...IT WILL BE HIGHLY DEPENDENT ON HOW MUCH SUNSHINE CAN
OCCUR WITH COOLER TEMPERATURES ALOFT. AT THIS POINT...NOT REAL
CONFIDENT ABOUT THE SUNSHINE FACTOR TOMORROW...ESPECIALLY WITH ALL
OF THE CLOUD COVER CURRENTLY MOVING THROUGH IDAHO AND NEVADA. WE
DID RAISE SNOW CHANCES MAINLY IN THE NORTHERN PANHANDLE TOMORROW
AFTERNOON AS THE LOW LEVEL COLDER AIR MOVES INTO THE AREA CAUSING
THE LOW LEVEL THETA SURFACES (290-295K)TO RISE FAIRLY QUICKLY DUE
TO GOOD COLD AIR ADVECTION. THIS SNOW WILL SPREAD SOUTH DURING
LATE AFTERNOON INTO THE SOUTHERN PANHANDLE AND SOUTHEAST WYOMING.
AS A RESULT...WE RAISED SNOW CHANCES DURING THE EVENING.
OVERALL...NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION WITH
SNOWFALL AMOUNTS GENERALLY AN INCH OR LESS IN THE EASTERN PLAINS
WITH GENERALLY 3-5 INCH AMOUNTS IN THE MOUNTAINS.
SUNDAY NIGHT-MONDAY:
ATMOSPHERE REMAINS FAIRLY SATURATED DURING THE EVENING INTO THE
OVERNIGHT HOURS...BUT THE UPPER LEVEL WAVE SHOULD BEGIN TO MOVE
OUT OF THE AREA BY THE EARLY SUNDAY EVENING. AS A RESULT...THIS
MAY RESULT IN SOME LINGERING LIGHT SNOW FLURRIES ALONG WITH SOME
PATCHY FOG. WE WERE NOT ENTIRELY CONFIDENT WITH THE FREEZING
DRIZZLE POTENTIAL AT THIS TIME...SINCE THE COLUMN STILL APPEARS TO
BE MOSTLY SATURATED. WE MAY DRY OUT A BIT ALOFT ON MONDAY
MORNING...BUT THE LIFT WILL ALSO BE QUITE MINIMAL. HOWEVER...WE
MAY HAVE TO KEEP AN EYE OUT ON THE CHEYENNE RIDGE DUE TO GOOD
UPSLOPE FLOW TRYING TO DEVELOP IN THE MORNING WHICH MAY RESULT IN
SOME PATCHY DENSE FOG. OTHERWISE...CHILLY CONDITIONS WILL PREVAIL
AS THE CANADIAN HIGH KEEPS ITS GRIP ON THE AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 136 PM MST SAT JAN 10 2015
MONDAY NIGHT...POSITIVELY TILTED SHORTWAVE TROUGH ALOFT TRACKS
ACROSS WESTERN WYOMING...EASTERN UTAH AND WESTERN COLORADO...WITH
THE NAM...GFS AND ECMWF KEEPING THE BULK OF THE SNOWFALL WITH THE
SHORTWAVE TROUGH...TO OUR SOUTH OVER COLORADO. ALTHOUGH THE 12Z NAM
DID SHOW MORE QPF OVER OUR FORECAST AREA...THAN DOES THE 18Z NAM OR
THE 12Z GFS AND ECMWF. WITH THIS TYPE OF TRACK THAT THE MODELS
INDICATE...WILL HAVE HIGH POPS...NEAR 100 PERCENT OVER THE HIGHER
PEAKS OF OUR SNOWY AND SIERRA MADRE RANGES...DUE TO DYNAMICS AND
OROGRAPHICS...WITH LOWER POPS NEAR THESE MOUNTAINS...AND FAR
SOUTHEAST WYOMING AND WESTERN NEBRASKA WILL LIKELY MISS OUT OF
MUCH OF THE MEASURABLE SNOWFALL EVENT.
TUESDAY...AFOREMENTIONED SHORTWAVE TROUGH ALOFT MOVES TO NORTHERN
NEW MEXICO BY SUPPERTIME...THOUGH WITH OROGRAPHIC SNOWS CONTINUING
ACROSS OUR SNOWY AND SIERRA MADRE RANGES...AND A FEW SNOW SHOWERS
NEARBY...AND DRY ELSEWHERE.
WEDNESDAY...BREEZY TO WINDY DAY ON TAP WITH NORTHWEST FLOW
ALOFT...AND DEEP UNIDIRECTIONAL NORTHWEST FLOW AT THE SURFACE AND
ALOFT...AND BASED ON THE PROGGED 700 MB GRADIENTS. MINIMAL LOW AND
MID LEVEL MOISTURE AND LACK OF LIFT SUGGESTS DRY WEATHER FOR ALL OUR
FORECAST AREA.
THURSDAY...WE EXPECT A DECENT WARMING TREND AS THE FLOW ALOFT BACKS
TO WEST...INDUCING OUR TYPICAL CHINOOK DOWNSLOPE WARMING AND SURFACE
LEE TROUGHING...AND IF THE OPACITY...THICKNESS...OF ANY MIDDLE AND
HIGH CLOUDS IS MINIMAL...EXPECT MAXIMUM TEMPERATURES TO SOAR WELL
INTO THE 30S ACROSS THE HIGHER VALLEY WEST OF INTERSTATE 25...AND
40S AND SOME 50S EAST OF I-25. PREFER THE WARMER GFS MEX MOS MAXIMA
OVER THE COOLER ECMWF MOS BASED ON THE SYNOPTIC PATTERN...EXPERIENCE
AND HOW MUCH DOWNSLOPE WARMING OFTEN ADDS TO THE POTENTIAL HIGH
TEMPERATURES.
FRIDAY...GFS AND ECMWF DIVERGE WITH THE 10/12Z ECMWF MAINTAINING
FAST WEST NORTHWEST FLOW ALOFT OVER OUR COUNTIES...WHEREAS THE
10/12Z GFS HAS BROAD TROUGHING ALOFT OVER OUR AREA. FOR
TEMPERATURES...THIS WOULD MAKE A SIGNIFICANT DIFFERENCE AND PREFER
THE WARMER GFS MOS MAX MAXIMA...AGAIN BASED ON EXPECTED SNOWMELT AND
WITH EXPERIENCE SEEING HOW MUCH DOWNSLOPE KATABATIC WARMING
DOES...ASSUMING MINIMAL OPACITY...THICKNESS...OF MIDDLE AND HIGH
CLOUDS.
SATURDAY...WITH ZONAL FLOW CONTINUING...ANOTHER DRY DAY ON TAP WITH
LIMITED LOW AND MID LEVEL MOISTURE AVAILABILITY. SLIGHTLY COOLER
TEMPERATURES ON TAP WITH MORE OPAQUE MIDDLE AND HIGH CLOUDS LIKELY
DOWNWIND OF FAST MOVING SHORTWAVE TROUGHS ALOFT TRAVERSING ACROSS
THE GREAT BASIN AND ROCKIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 959 PM MST SAT JAN 10 2015
EXPECT LOWERING CLOUDS OVER THE NEXT 24 HOURS AS A COLD FRONT
CURRENTLY IN MONTANA DROPS SOUTH AND LAYS UP AGAINST THE LARAMIE
RANGE BY LATE SUNDAY AFTERNOON. BEHIND THE FRONT...NORTHEAST
UPSLOPING WINDS WILL CREATE IFR/LIFR CONDITIONS WITH STRATUS AND
LIGHT SNOW THAT WILL CONTINUE INTO MONDAY. HRRR CONTINUES TO
SUGGEST LOWERING CONDITIONS AT KRWL TONIGHT...BUT GIVEN SIMILAR
CONDITIONS LAST NIGHT AND NOTHING HAPPENING...CONFIDENCE IS NOT
THERE TO BRING THEM DOWN.
&&
.FIRE WEATHER...
ISSUED AT 136 PM MST SAT JAN 10 2015
MINIMAL ISSUES DUE TO EXPECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...REC
LONG TERM...RUBIN
AVIATION...GCC
FIRE WEATHER...REC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1049 PM MST MON JAN 12 2015
.UPDATE...
ISSUED AT 733 PM MST MON JAN 12 2015
AREAS OF FZFG PRECIP ARE BECOMING MORE SPOTTY AND LIGHT ACROSS
EL PASO COUNTY...AND THIS TREND SHOULD CONTINUE OVERNIGHT.
DENSE FOG LIKELY TO REMAIN AN ISSUE...SO HAVE REPLACED THE
WINTER WEATHER ADVISORY WITH A FREEZING FOG ADVISORY...WHICH
COMBINES THE ELEMENTS OF DENSE FOG AND SPOTTY FREEZING DRIZZLE.
SHOULD SEE THESE AREAS OF DENSE FOG BREAK UP LATER TUESDAY
MORNING. LATEST NAM HAS CUT BACK ON SNOW AMOUNTS FOR THE ERN
MTS TOMORROW...SO WILL HOLD BACK ON ANY HIGHLIGHTS FOR SNOW E OF
THE CONTDVD AND SURROUNDING AREAS. ROSE
UPDATE ISSUED AT 541 PM MST MON JAN 12 2015
UPDATED FOR LATEST OBS AND TRENDS. CUT BACK ON POPS A LITTLE
OVER THE ERN ZONES AS PRECIP SHIFTS TOT HE EAST. HEADLINES
LOOK ON TRACK. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 238 PM MST MON JAN 12 2015
CURRENTLY...DENSE FOG AND FREEZING DRIZZLE CONTINUE ACROSS EL
PASO COUNTY...FORCED BY WEAK E-SE UPSLOPE FLOW AND AIDED BY A
FAIRLY DEEP FRESH SNOW COVER...ESPECIALLY OVER THE EASTERN HALF OF
THE COUNTY. GIVEN LATEST HRRR PROG OF LOW LEVEL E-SE WINDS
CONTINUING THROUGH THE EVENING...WILL EXTEND TIME OF WINTER WX ADV
INTO MID EVENING. NOT EXPECTING MUCH MORE IN THE WAY OF ICE
ACCUMULATION...BUT WITH MOST OBSERVATION SITES STILL REPORTING
FZDZ...WILL HOLD OFF ON CONVERTING TO A DENSE FOG ADVISORY FOR
NOW...THOUGH ONE MAY BEE NEEDED LATER TONIGHT. ELSEWHERE...WEAK
TROUGH WAS PRODUCING SOME LIGHT SNOW OVER THE EASTERN
PLAINS...WHILE MOUNTAINS HAVE SEEN ONLY A FEW FLURRIES AS MUCH OF
THE AREA IS CURRENTLY BETWEEN WAVES.
OVERNIGHT...UPPER LOW WILL DROP SOUTH THROUGH GREAT BASIN...TAKING
A TRACK SLIGHTLY TO THE WEST OF YESTERDAY`S MODEL SOLUTIONS.
EXPECT SNOW TO BREAK OUT THIS EVENING OVER THE SOUTHWEST MOUNTAINS
THEN SPREAD NORTHWARD THROUGH THE LA GARITAS AND SAWATCH RANGE
BY MIDNIGHT. KEPT THE WARNING IN PLACE FOR THE SAN JUANS...AND
CHANGED WATCH TO AN ADVISORY FARTHER NORTH. EASTERN MOUNTAINS WILL
SEE OCCASIONAL FLURRIES THROUGH THE NIGHT...THEN A STEADIER LIGHT
SNOW BEGINS TOWARD MORNING AS UPWARD MOTION GRADUALLY STRENGTHENS.
ONCE BAND OF SNOW ON THE PLAINS EXITS THE AREA THIS
EVENING...SUSPECT LOWER ELEVATIONS WILL SEE ONLY SOME SOME
FLURRIES/FOG/-FZDZ OVERNIGHT...AS SHALLOW UPSLOPE FLOW WILL BE THE
MAIN MECHANISM DRIVING CLOUDS/PRECIP. NAM HINTS AT SOME DRYING
AFTER 06Z AS LOW/MID LEVEL FLOW TAKES ON A VERY SLIGHT SW
COMPONENT...THOUGH DOUBTFUL IT WILL BE ENOUGH TO SCOUR OUT CLOUDS
AND FOG...THOUGH VISIBILITY MIGHT IMPROVE MARGINALLY. GIVEN
AMOUNT OF CLOUD COVER...NUDGED LOW TEMPS UP SLIGHTLY...ESPECIALLY
EASTERN PLAINS.
TUESDAY...UPPER TROUGH CONTINUES TO DROP SOUTH OR SLIGHTLY
SOUTHWEST INTO ARIZONA...WITH TRACK A LITTLE LESS FAVORABLE FOR
HEAVY SNOW OVER THE EASTERN MOUNTAINS AND PLAINS. CONTINENTAL
DIVIDE WILL STILL SEE PERIODS OF MODERATE/HEAVY SNOW THROUGH THE
DAY AS MOIST S-SW FLOW CONTINUES...WITH LIGHTER AND LESS STEADY
SNOW OVER THE REMAINING MOUNTAINS AND WESTERN VALLEYS. EASTERN
MOUNTAINS WILL SEE SOME LIGHT SNOW THROUGH THE DAY...POSSIBLY
BECOMING A LITTLE HEAVIER LATE IN THE AFTERNOON AS SURFACE THROUGH
700 MB FLOW BECOMES MORE UPSLOPE IN RESPONSE TO FALLING PRESSURE
OVER NWRN NM. I-25 CORRIDOR AND PLAINS MAY STAY DRY MUCH OF THE
DAY...WITH SNOW DEVELOPING LATE IN THE AFTERNOON...ESPECIALLY
FROM SOUTH OF PUEBLO TO THE NM BORDER. MAX TEMPS TO GO NOWHERE
ONCE AGAIN WITH CLOUDS AND SNOW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 238 PM MST MON JAN 12 2015
TUESDAY NIGHT AND WEDNESDAY...MODELS ARE IN FAIRLY GOOD AGREEMENT ON
TIMING AND LOCATION OF THE UPPER TROUGH THROUGH WED. TUE NIGHT THE
UPPER LOW DROPS SOUTH NEAR THE 4 CORNERS AND CONTINUES DUE SOUTH
INTO S-SE ARIZONA. WED MORNING THIS UPPER LOW WEAKENS AND SLIDES TO
THE EAST ACROSS SOUTHERN NEW MEXICO. THE EC...GFS AND NAM MODELS ARE
ALL INDICATING THIS PATH...WHICH IS A LITTLE TOO FAR SOUTH FOR ANY
LONG-LASTING SIGNIFICANT SNOWFALL EVENT...IF IT HOLDS TOGETHER.
THEREFORE...FINE TUNED THE POP GRIDS SLIGHTLY TO SHOW WIDESPREAD
AREAL COVERAGE OF PCPN TUE NIGHT BEFORE MIDNIGHT...THEN THE FOCUS OF
THE SNOW WILL SHIFT TO THE SOUTH AS THE LOW PULLS SOUTH AND PCPN
BEGINS TAPERING OFF ACROSS THE NORTH. WED MORNING ISOLATED TO LOW
END SCATTERED POPS ARE FORECAST FOR THE SOUTHERN MTS...THEN PCPN
ENDS AND CLOUDS START TO DIMINISH FROM NORTH TO SOUTH THROUGH THE
AFTERNOON. LOOK FOR A COLD NIGHT TUE WITH LOWS IN THE TEENS TO
SINGLE DIGITS...THEN SLIGHTLY WARMER ON WED AS CONDITIONS BEGIN TO
IMPROVE.
WEDNESDAY NIGHT THROUGH SATURDAY...HIGH PRESSURE OVER THE DESERT SW
WILL HELP TO SHUNT MUCH OF THE ACTIVITY NORTH OF COLORADO...KEEPING
THE FORECAST AREA DRY WITH GRADUAL WARMING. TWO DISTURBANCES WILL
CROSS THE NORTHERN ROCKIES...ONE THU NIGHT AND THE OTHER ON
SAT...BUT AT THIS TIME THEY LOOK TOO FAR NORTH TO AFFECT THE CWA.
LOOK FOR COOL NIGHTS WITH AFTN MAX TEMPS IN THE 40S AND 50S FOR THE
PLAINS...30S TO AROUND 40F FOR THE HIGH VALLEYS.
SUNDAY AND MONDAY...ANOTHER STRONGER DISTURBANCE MOVES INTO THE PAC
NW ON SUNDAY. BOTH THE GFS AND EC STILL PAINT DRY WESTERLY FLOW
ALOFT FOR THE STATE BOTH DAYS...BUT THE EXTENDED PROCEDURE KEEPS
WANTING TO INCLUDE ISOLATED POPS FOR THE CENT MTS
INITIALLY...SPREADING TO ALL OF THE MTS FOR MON. AT THIS TIME...SEE
NO STRONG REASON TO STRAY FAR FROM THE PROCEDURE SINCE A SLIGHT
CHANGE IN COURSE FOR THE WEEKEND DISTURBANCE COULD CERTAINLY BROUGHT
ISOLATED SNOW TO OUR MTS. MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1036 PM MST MON JAN 12 2015
IFR/LIFR CONDITIONS LIKELY TO CONTINUE THROUGH THE BULK OF THE
PERIOD OVER THE EAST SLOPES OF THE MOUNTAINS AND ADJACENT PLAINS
INCLUDING KCOS AND KPUB. MOIST...LOW LEVEL UPSLOPE FLOW INTO THE
TERRAIN LIKELY TO CONTINUE IN THESE AREAS UNTIL THE UPPER LOW
PRESSURE SYSTEM CAUSING THE WEATHER SCOOTS SOUTH OF THE FLIGHT
AREA LATE TUESDAY NIGHT. OUT ACROSS THE PLAINS...FARTHER AWAY FROM
THE TERRAIN...NOT QUITE SO BAD BUT STILL MVFR TO IFR THROUGH THE
BULK OF THE PERIOD. FOR THE MOUNTAINS AND SAN LUIS VALLEY...REALLY
MUCH THE SAME DEAL. KALS HAS EXPERIENCED A BIT OF A REPRIEVE TODAY
INTO THIS EVENING. HOWEVER...CIGS AND VSBYS THAT ARE CURRENTLY
MVFR IN THAT AREA ARE LIKELY TO GO DOWN THROUGH THE NIGHT AND
TUESDAY AS THE UPPER LOW PRESSURE SYSTEM NEARS. MODERATE TO HEAVY
SNOW OVER THE SOUTHWEST MOUNTAINS WITH THIS SYSTEM AND GENERALLY
LIGHT TO MODERATE SNOW ELSEWHERE. LAST...AND CERTAINLY NOT
LEAST...FREEZING DRIZZLE...FREEZING FOG...AND DENSE FOG WILL
CONTINUE TO BE AVIATION HAZARDS THROUGH THE PERIOD...BUT
ESPECIALLY TONIGHT...AND ESPECIALLY ALONG AND NEAR THE EAST SLOPES
OF THE MOUNTAINS...INCLUDING BOTH KCOS AND KPUB.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 8 AM MST TUESDAY FOR COZ084-085.
WINTER WEATHER ADVISORY UNTIL 11 PM MST TUESDAY FOR COZ058-060-
061-064-066.
WINTER STORM WARNING UNTIL 5 PM MST TUESDAY FOR COZ068.
&&
$$
UPDATE...ROSE
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...LW
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
311 AM CST TUE JAN 13 2015
.SYNOPSIS...
ISSUED AT 310 AM CST TUE JAN 13 2015
SURFACE HIGH PRESSURE CENTERED NORTH OF LA CROSSE WAS PROVIDING
CLEAR SKIES AND COLD CONDITIONS OVER MOST OF THE AREA EARLY THIS
MORNING. AN AREA OF LAKE GENERATED STRATUS WITH SNOW SHOWERS WAS
EVIDENT ON FOG CHANNEL IMAGERY AND SURFACE OBSERVATIONS OVER
NORTHERN IL...WHICH HAS BEEN CREEPING WESTWARD OVER THE PAST SEVERAL
HOURS. AT 08Z...THE LEADING EDGE OF THESE CLOUDS WAS ROUGHLY FROM
SAVANNA TO KEWANEE. WEAK RADAR RETURNS AND SURFACE OBSERVATIONS
INDICATED FLURRIES HAVE REACHED AS FAR WEST AS PRINCETON IL TO
STERLING IL. TEMPERATURES VARIED WIDELY...MOSTLY IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO WHERE SKIES CLEAR...TO THE UPPER
SINGLE DIGITS AND TEENS UNDER THE CLOUD COVER AND STRONGER
NORTHERLY FLOW ACROSS THE EAST. ALOFT...A NW FLOW PREVAILED WITH A
SHORTWAVE OF INTEREST MOVING ACROSS SASKATCHEWAN AND EASTERN MT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CST TUE JAN 13 2015
TRENDS WITH TEMPERATURES AND CLOUD COVER DOMINATE THE IMMEDIATE
SHORT TERM. FOCUS THEN TURNS TO THE EFFECTS OF THE SHORTWAVE PUSHING
THROUGH LATER TONIGHT.
AS THE SURFACE HIGH CONTINUES EASTWARD...THE CURRENT SURFACE
THROUGH 925 MB EASTERLY FLOW AND TRAJECTORY OF MOISTURE OFF LAKE
MI WILL BECOME LESS FAVORABLE THIS MORNING. THIS BIG QUESTION WILL
BE HOW FAR WEST THE CLOUD FIELD ADVANCES BEFORE DISSIPATING UNDER
THE LARGELY SUBSIDENT...CONFLUENT MID LEVEL FLOW. THE ROUGH
AGREEMENT IN THE 06Z WRF AND RAP MODELED MOISTURE FIELDS IN THE
900 TO 950 MB LAYERS...THAT HAD A DECENT HANDLE ON THE CURRENT
TRENDS...INDICATE THE CLOUDS SHOULD ADVANCE TO AT LEAST THE MS
RIVER INTO EXTREME EASTERN IA TOWARD MID MORNING BEFORE THINNING
OUT ALTOGETHER BY NOON AND HAVE FOLLOWED THIS TREND. FOR
NOW...WILL HAVE FLURRIES ENDING BEFORE SUNRISE ONLY OVER NW
IL...BUT WILL WATCH RADAR AND OBSERVATIONS OBSERVATIONS CLOSELY
FOR THE POSSIBLE NEED TO CONTINUE LONGER AND POSSIBLY REACH INTO
EASTERN IA.
THROUGH THE REST OF THE DAY...MOSTLY SUNNY SKIES AND LIGHT WINDS
WILL LIMIT MIXING AND PREVIOUS FORECAST HIGHS IN THE MID TO UPPER
TEENS LOOK REASONABLE.
TONIGHT...WEAK LIFT AND MID LEVEL MOISTURE WITH THE INCOMING
SHORTWAVE SHOULD LEAD TO INCREASING CLOUDS OVERNIGHT. THE CURRENT
TIMING SUGGESTS THIS MAY NOT OCCUR UNTIL LATE OVER THE EAST...WHERE
THE LIGHT WINDS AND SNOW COVER WILL AGAIN FAVOR LOWS NEAR OR A FEW
DEGREES BELOW ZERO...WITH A RAPID DROP OFF POSSIBLE IN THE EVENING.
IN THE WEST...INCREASING CLOUDS AND AT LEAST LIGHT SW WINDS SHOULD
HOLD MINS IN THE SINGLE DIGITS ABOVE ZERO...WITH STEADY TO POSSIBLY
RISING TEMPERATURES TOWARD MORNING. THE WEAK MID LEVEL LIFT REACHES
INTO THE NORTHWEST HALF OF THE FORECAST AREA TOWARD MORNING...BUT
WITH THE DEEP LAYER OF DRY AIR AT THE SURFACE...LIKELY THROUGH AT
LEAST 800 MB...PRECIPITATION DOES NOT LOOK LIKELY. WILL MENTION
POSSIBLE FLURRIES IN THE FAR NW TOWARD SUNRISE WHERE THE LIFT
LOOKS TO BE MAXIMIZED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 310 AM CST TUE JAN 13 2015
FORECAST FOCUS ON A WELCOME WARMING TREND THROUGH THIS EXTENDED
PERIOD ALONG WITH LITTLE IF ANY PRECIPITATION.
WEDNESDAY...A WEAK UPPER LEVEL TROUGH WILL SWING THROUGH THE REGION
IN THE MORNING. HOWEVER...FORECAST SOUNDINGS INDICATE THE COLUMN IS
MOISTURE STARVED AND MODELS SUGGEST FORCING IS QUITE WEAK...SO WILL
HAVE ONLY 20 POPS. MAY BE ABLE TO SQUEEZE OUT SOME FLURRIES BUT THE
WORST CASE SCENARIO WOULD BE A DUSTING IN A FEW SPOTS. NONE OF THE
OPERATIONAL MODELS PAINT ANY QPF IN THE DVN CWA...KEEPING THE BULK
OF THE QPF TO OUR NORTH WHERE THE BETTER FORCING WILL EXIST. MAXIMUM
TEMPERATURES WILL PUSH INTO THE LOWER TO MID 20S.
THURSDAY THROUGH SATURDAY...UPPER FLOW TRANSITIONS TO A MORE ZONAL
FLOW BRINGING A MILDER PACIFIC AIRMASS INTO THE MIDWEST. THIS WILL
ALLOW FOR A WARMING TREND AND BY THE TIME WE GET TO FRIDAY AND
SATURDAY HIGH TEMPERATURES WILL BE SOARING WELL INTO THE 30S AND 40S.
MUCH OF THE SNOW ON THE GROUND WILL BE MELTED BY THEN.
SUNDAY THROUGH MONDAY...A COUPLE OF CLIPPER SYSTEMS TRACK TO OUR
NORTH WITH THE OPERATIONAL MODELS KEEPING THE BULK OF THE
PRECIPITATION NORTH OF THE DVN CWA. HOWEVER...CAN`T RULE OUT
SOMETHING SNEAKING INTO THE CWA ESPECIALLY IF THE SYSTEMS TRACK
FARTHER SOUTH THAN CURRENTLY INDICATED. BEHIND EACH STORM SYSTEM A
COLD FRONT DROPS INTO THE CWA KNOCKING OUR HIGH TEMPERATURES BACK DOWN
INTO THE 30S...BUT THE CONSENSUS MODELS MAY NOT BE COLD ENOUGH FOR
LATER SHIFTS TO MONITOR.
HAASE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1121 PM CST MON JAN 12 2015
CLEAR/UNLIMITED VFR WEATHER IS EXPECTED TO LAST THROUGH THE PERIOD
OVER EASTERN IOWA AND WESTERN ILLINOIS. MODELS ARE TRYING TO BRING
LAKE MICHIGAN STRATUS INTO LOCATIONS ALONG THE MISSISSIPPI RIVER
BY ABOUT 09Z/13...BUT THIS APPEARS TO BE TOO AGGRESSIVE AT THIS TIME
AND WILL BE PLACED INTO TAFS AS A SCATTERED CIGS SINCE THE SATELLITE
FOG CHANNEL SHOWS THE WESTERN EDGE SCATTERING OUT. THE TREND MAY
YET NEED TO ADD A TEMPORARY MVFR CIG...ESPECIALLY AT DBQ AND MLI
IF THE BAND OF CLOUDS CAN MAINTAIN A WIDESPREAD NATURE.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...HAASE
AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
317 AM CST TUE JAN 13 2015
...UPDATED LONG TERM SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 239 AM CST TUE JAN 13 2015
THE LATEST MODEL RUNS ON DIGGING AN UPPER LEVEL TROUGH/LOW SOUTH
INTO SOUTHERN ARIZONA THROUGH EARLY WEDNESDAY APPEARS REASONABLE
GIVEN THE LOCATION OF AN +90KNOT JET ON THE WEST SIDE OF A 500MB
TROUGH/LOW, WHICH WAS LOCATED OVER SOUTHERN IDAHO EARLIER THIS
MORNING. LOW TO MID LEVEL MOISTURE WILL RETURN TO SOUTHWEST
KANSAS LATER TODAY AND EARLY TONIGHT BASED ON THE 00Z NAM 300 TO
308 ISENTROPIC SURFACES WHICH INDICATES IMPROVING LIFT AS ANOTHER
AREA OF MOISTURE RETURNS TO WESTERN KANSAS AFTER 18Z TUESDAY. WITH
IMPROVING LIFT LATE TODAY AND EARLY THIS EVENING ALONG WITH THE
LOCATION OF WHERE THE BETTER MOISTURE IS EXPECTED WILL LOWER
PRECIPITATION CHANCES ACROSS NORTH CENTRAL KANSAS. FURTHER SOUTH
WILL CONTINUE TO FOLLOW THE PREVIOUS FORECAST AN INCREASE CHANCES
FOR LIGHT SNOW DURING THE EARLY EVENING HOURS. WILL ALSO HIGHLIGHT
THE BETTER CHANCES FOR PRECIPITATION WITH A 700MB BAROCLINIC ZONE
AS IT CROSSES WESTERN KANSAS OVERNIGHT. EVEN WITH THE ENHANCED
LIFT EXPECTED WITH THE 700MB BAROCLINIC ZONE ACCUMULATIONS ARE
EXPECTED TO BE LIGHT AND AVERAGE LESS THAN ONE HALF OF AN INCH.
GFS AND NAM BOTH SHOWING ISENTROPIC DOWNGLIDE DEVELOPING BY 06Z
WEDNESDAY IN SOUTH CENTRAL KANSAS AND THEN SPREADS THIS AREA EAST
THROUGH 12Z. THERE WILL BE A CHANCE FOR SOME CLEARING TOWARDS
DAYBREAK IN NORTH CENTRAL KANSAS GO BASED ON THE POTENTIAL FOR
CLEARING HAVE LOWER THE LOWS FOR TONIGHT NEAR THE I70 CORRIDOR
BACK INTO THE 10 TO 15 DEGREE RANGE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 317 AM CST TUE JAN 13 2015
THE UPPER PATTERN WILL EXHIBIT A SPLIT FLOW SYNOPTIC FLOW WITH
RESPECT TO THE UPPER JET ENERGY. THE JET IMMEDIATELY TO THE SOUTH
EXTENDING ACROSS WESTERN MEXICO THROUGH THE RED RIVER VALLEY, WILL
SPREAD INTO THE SOUTHEAST STATES AS NORTHWEST FLOW ALOFT WILL
QUICKLY BECOME ESTABLISHED OVER THE CENTRAL HIGH PLAINS. THE
DEFORMATION/SHEAR ZONE ASSOCIATED WITH THIS WILL BE THE ONLY
OPPORTUNITY FOR SOME LIGHT PRECIPITATION VERY EARLY WEDNESDAY, BIT
THIS DOES NOT APPEAR LIKELY AS A MUCH DRIER AIRMASS IS WORKING INTO
KANSAS AT THAT TIME. WEAK WESTERLY DOWNSLOPE WINDS WILL BRING
MODERATING TEMPERATURES FOR WEDNESDAY AND THURSDAY. THE ECMWF MOS WAS
FOLLOWED INTO THURSDAY WHICH PROVIDED THE WARMEST SOLUTION OF ALL
THE MOS AND RAW OUTPUT.
THE 4-7 DAY PERIOD, ESSENTIALLY THE WEEKEND AND INTO EARLY NEXT
WEEK, WILL ALSO REMAIN MILD COMPARED TO RECENT PAST TRENDS. HOWEVER,
A COUPLE OF WEAK FRONTS MAY BE DIFFICULT TO TIME AND KNOW THE TRUE
MAGNITUDE OF THE COLD ADVECTION OR IMPACTS OF WINDS. THE ECMWF AND
GFS SUGGEST THE SATURDAY TIMEFRAME A WINDOW FOR SUCH AN EVENT, WITH
YET ANOTHER FAST MOVING WAVE ON IT`S HEELS BETWEEN SUNDAY NIGHT AND
TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM CST MON JAN 12 2015
LIGHT EAST/NORTHEAST WINDS WILL GRADUALLY SHIFT TO THE SOUTHEAST
EARLY TUESDAY MORNING AS A SURFACE RIDGE AXIS MOVES EAST ACROSS
EASTERN KANSAS AND A WEAK SURFACE TROUGH OF LOW PRESSURE BEGINS TO
DEVELOP OVER EASTERN COLORADO. SCATTERED FLURRIES WILL MOVE NORTH
ACROSS WEST CENTRAL AND EVEN PORTIONS OF NORTH CENTRAL KANSAS
BETWEEN 06Z AND 12Z TUESDAY AS AN AREA OF 800MB TO 600MB MOISTURE
AND WEAK LIFT MOVES NORTH TOWARDS THE NEBRASKA BORDER BASED ON
THE RAP I300 TO I308 ISENTROPIC SURFACES. A PERIOD OF MVFR
CEILINGS AND VISIBILITIES WILL ALSO BE POSSIBLE WITH THESE
FLURRIES/LIGHT SNOW EARLY THIS MORNING, MAINLY AT NEAR AND
WEST/NORTHWEST OF GCK AND HYS. OUTSIDE THESE FLURRIES CEILINGS
OVERNIGHT ARE EXPECTED TO RANGE FROM 4000FT TO 8000FT AGL BASED ON
BUFR SOUNDINGS. MVFR CEILINGS WILL BEGIN TO SPREAD FROM SOUTHWEST
TO NORTHEAST ACROSS WESTERN KANSAS BETWEEN 15Z AND 18Z TUESDAY AND
THE PREVAILING SURFACE WINDS WILL BE SOUTHEAST AT 10 KNOTS OR LESS
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 29 16 39 18 / 20 30 10 0
GCK 30 15 40 14 / 10 20 10 0
EHA 33 19 39 19 / 20 30 10 0
LBL 32 17 39 17 / 20 40 10 0
HYS 28 14 37 16 / 20 20 0 0
P28 30 19 35 20 / 20 30 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
253 AM CST TUE JAN 13 2015
...UPDATED SHORT TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 239 AM CST TUE JAN 13 2015
THE LATEST MODEL RUNS ON DIGGING AN UPPER LEVEL TROUGH/LOW SOUTH
INTO SOUTHERN ARIZONA THROUGH EARLY WEDNESDAY APPEARS REASONABLE
GIVEN THE LOCATION OF AN +90KNOT JET ON THE WEST SIDE OF A 500MB
TROUGH/LOW, WHICH WAS LOCATED OVER SOUTHERN IDAHO EARLIER THIS
MORNING. LOW TO MID LEVEL MOISTURE WILL RETURN TO SOUTHWEST
KANSAS LATER TODAY AND EARLY TONIGHT BASED ON THE 00Z NAM 300 TO
308 ISENTROPIC SURFACES WHICH INDICATES IMPROVING LIFT AS ANOTHER
AREA OF MOISTURE RETURNS TO WESTERN KANSAS AFTER 18Z TUESDAY. WITH
IMPROVING LIFT LATE TODAY AND EARLY THIS EVENING ALONG WITH THE
LOCATION OF WHERE THE BETTER MOISTURE IS EXPECTED WILL LOWER
PRECIPITATION CHANCES ACROSS NORTH CENTRAL KANSAS. FURTHER SOUTH
WILL CONTINUE TO FOLLOW THE PREVIOUS FORECAST AN INCREASE CHANCES
FOR LIGHT SNOW DURING THE EARLY EVENING HOURS. WILL ALSO HIGHLIGHT
THE BETTER CHANCES FOR PRECIPITATION WITH A 700MB BAROCLINIC ZONE
AS IT CROSSES WESTERN KANSAS OVERNIGHT. EVEN WITH THE ENHANCED
LIFT EXPECTED WITH THE 700MB BAROCLINIC ZONE ACCUMULATIONS ARE
EXPECTED TO BE LIGHT AND AVERAGE LESS THAN ONE HALF OF AN INCH.
GFS AND NAM BOTH SHOWING ISENTROPIC DOWNGLIDE DEVELOPING BY 06Z
WEDNESDAY IN SOUTH CENTRAL KANSAS AND THEN SPREADS THIS AREA EAST
THROUGH 12Z. THERE WILL BE A CHANCE FOR SOME CLEARING TOWARDS
DAYBREAK IN NORTH CENTRAL KANSAS GO BASED ON THE POTENTIAL FOR
CLEARING HAVE LOWER THE LOWS FOR TONIGHT NEAR THE I70 CORRIDOR
BACK INTO THE 10 TO 15 DEGREE RANGE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 150 PM CST MON JAN 12 2015
MOSTLY CLOUDY SKIES WILL CONTINUE TUESDAY NIGHT AS A WEAK UPPER
LEVEL TROUGH SHIFTS EASTWARD INTO THE PLAINS. LIGHT SNOW SHOWERS
WILL BE POSSIBLE OVERNIGHT WITH THE BEST CHANCE CONFINED TO SOUTH
CENTRAL KANSAS. ANY ACCUMULATIONS SHOULD BE LIGHT AND LESS THAN AN
INCH. CLOUDS THEN DECREASE IN COVERAGE FROM NORTH TO SOUTH
WEDNESDAY MORNING WITH MOSTLY CLEAR SKIES EXPECTED BY WEDNESDAY
EVENING. THE REMAINDER OF THE EXTENDED FORECAST LOOKS DRY AS UPPER
LEVEL RIDGING BUILDS ACROSS THE WESTERN UNITED STATES WITH A
TROUGH SHIFTING EASTWARD INTO THE EASTERN UNITED STATES. A FEW
WEAK SHORTWAVES LOOK TO MOVE THROUGH THIS FLOW LATER IN THE WEEK
BUT ONLY IMPACT WESTERN KANSAS WITH A WIND SHIFT FROM SOUTHWEST TO
NORTHWEST, THEN QUICKLY BACK TO SOUTHWEST. SKIES WILL GENERALLY BE
MOSTLY CLEAR WEDNESDAY AFTERNOON INTO THIS WEEKEND WITH A GRADUAL
WARMING TREND. HIGHS LOOK TO INCREASE FROM THE UPPER 30S WEDNESDAY
TO LOWER 50S FRIDAY INTO THIS WEEKEND. LOWS LOOK TO DIP INTO THE
UPPER TEENS WEDNESDAY AND THURSDAY MORNING RISING INTO THE 20`S
AND POSSIBLY AROUND 30 DEGREES BY THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM CST MON JAN 12 2015
LIGHT EAST/NORTHEAST WINDS WILL GRADUALLY SHIFT TO THE SOUTHEAST
EARLY TUESDAY MORNING AS A SURFACE RIDGE AXIS MOVES EAST ACROSS
EASTERN KANSAS AND A WEAK SURFACE TROUGH OF LOW PRESSURE BEGINS TO
DEVELOP OVER EASTERN COLORADO. SCATTERED FLURRIES WILL MOVE NORTH
ACROSS WEST CENTRAL AND EVEN PORTIONS OF NORTH CENTRAL KANSAS
BETWEEN 06Z AND 12Z TUESDAY AS AN AREA OF 800MB TO 600MB MOISTURE
AND WEAK LIFT MOVES NORTH TOWARDS THE NEBRASKA BORDER BASED ON
THE RAP I300 TO I308 ISENTROPIC SURFACES. A PERIOD OF MVFR
CEILINGS AND VISIBILITIES WILL ALSO BE POSSIBLE WITH THESE
FLURRIES/LIGHT SNOW EARLY THIS MORNING, MAINLY AT NEAR AND
WEST/NORTHWEST OF GCK AND HYS. OUTSIDE THESE FLURRIES CEILINGS
OVERNIGHT ARE EXPECTED TO RANGE FROM 4000FT TO 8000FT AGL BASED ON
BUFR SOUNDINGS. MVFR CEILINGS WILL BEGIN TO SPREAD FROM SOUTHWEST
TO NORTHEAST ACROSS WESTERN KANSAS BETWEEN 15Z AND 18Z TUESDAY AND
THE PREVAILING SURFACE WINDS WILL BE SOUTHEAST AT 10 KNOTS OR LESS
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 29 16 37 19 / 20 30 10 0
GCK 30 15 38 18 / 10 20 10 0
EHA 33 19 40 20 / 20 30 10 0
LBL 32 17 39 19 / 20 40 10 0
HYS 28 14 35 17 / 20 20 10 0
P28 30 19 37 20 / 20 30 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...HOVORKA_42
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1116 PM CST MON JAN 12 2015
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1112 PM CST MON JAN 12 2015
AT 00Z TUESDAY A -25C 500MB TROUGH WAS LOCATED OVER SOUTHERN
IDAHO AND NORTHWESTERN UTAH WITH THE BETTER 12HOUR 500MB HEIGHT
FALLS BEING PRESENT TO ITS SOUTH SOUTHEAST. A NORTH SOUTH ORIENTED
250MB 90KT JET STREAK WAS LOCATED ON THE WEST SIDE OF THIS UPPER
LEVEL SYSTEM. FURTHER EAST A SURFACE TO 850MB HIGH EXTENDED FROM
EAST CENTRAL NEW MEXICO, ACROSS KANSAS AND NEBRASKA, INTO
SOUTHWEST MINNESOTA AND DIFLUENT FLOW WAS PRESENT AT THE 700MB
LEVEL OVER THE CENTRAL HIGH PLAINS. RADAR AND A SURFACE
OBSERVATION INDICATED SOME VERY LIGHT SNOW WAS OCCURRING EARLIER
THIS MORNING ACROSS WHERE THE BETTER 700MB MOISTURE AND DIFLUENT
FLOW WAS OBSERVED. DODGE CITY SOUNDING INDICATED A 580MB TO 500MB
MOIST LAYER WITH WINDS IN THIS LAYER VEERING WITH HEIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 1257 PM CST MON JAN 12 2015
THERE IS ANOTHER LARGE CANADIAN SURFACE HIGH PRESSURE SYSTEM
MOVING SOUTH-SOUTHEAST FROM SASKATCHEWAN, CANADA, THROUGH THE
EASTERN DAKOTAS, AND SHOULD BE CENTERED OVER NORTHERN IOWA AND
SOUTHERN MINNESOTA BY 14/00Z OR TUESDAY EVENING. BY 00Z THIS
EVENING, THE 850MB FLOW WILL BECOME ESTABLISHED FROM THE SOUTH TO
SOUTHWEST AT 15G25 KNOTS. THIS WILL CAUSE AN OVERRUNNING PATTERN
OF MOISTURE, WITH THE MAIN RESULT BEING STRATUS CLOUDS SPREADING
OVER NEARLY ALL OF OUR CWA. THIS MOIST LAYER WILL EFFECTIVELY
TRAP THE COLD LAYER NEAR THE SURFACE, AND COLD AIR ADVECTION
SHOULD RESULT IN QUITE COLD MINIMUMS TONIGHT. LOWS TONIGHT WILL
RANGE FROM NEAR 6F DEGREES AT HAYS TO 14F DEGREES AT ELKHART. ONE
SAVING GRACE FOR THIS WINTER PATTERN WILL BE RATHER LIGHT WINDS
FROM THE EAST OR SOUTHEAST AT LESS THAN 10 MPH. RESULTING WIND
CHILLS SHOULD RANGE FROM THE -6F TO -7F DEGREE RANGE NORTH OF
I-70, TO THE +3F TO +4F DEGREE RANGE IN THE MORTON COUNTY AREA.
TUESDAY SHOULD REMAIN SOCKED IN WITH STRATUS CLOUDS, WITH SURFACE
WINDS BLOWING FROM THE SOUTHEAST AT 8MPH OR LESS EARLY, BUT
INCREASING TO THE 10 TO 15 MPH RANGE ABOUT MIDDAY FOR A FEW HOURS,
AS A MID LEVEL TROUGH COMES ACROSS FROM THE WEST. THERE WILL BE A
SLIGHT CHANCE FOR LIGHT SNOW OR FLURRIES BY LATE AFTERNOON, AS THE
MID LEVEL TROUGH PROVIDES SOME UPPER LIFT OVER THE COLD DOME.
THERE COULD BE A FEW FLURRIES AS EARLY AS 22Z IN THE HAYS AREA,
BUT THEN THE BROADER SCALE LIFT WILL EXPAND SOUTH TO BARBER COUNTY
AND THEN WESTWARD TO NEAR ELKHART BY 00Z WEDNESDAY. I STILL THINK
THIS LIGHT SNOW EVENT WILL BE MAINLY FLURRIES, BUT A LITTLE MORE
THAN THAT CAN BE EXPECTED TOWARDS 0Z WEDNESDAY, MAINLY DUE TO
INCREASING UPWARD MID LEVEL SUPPORT FROM THE MID LEVEL TROUGH
PASSING TOWARD THE SOUTHEAST. I DID NOT CHANGE THE MAX TEMPS ANY
FOR TUESDAY, LEAVING THEM RANGING FRO 26F DEGREES AT HAYS TO 33F
DEGREES IN OUR SOUTHWEST NEAR ELKHART.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 150 PM CST MON JAN 12 2015
MOSTLY CLOUDY SKIES WILL CONTINUE TUESDAY NIGHT AS A WEAK UPPER
LEVEL TROUGH SHIFTS EASTWARD INTO THE PLAINS. LIGHT SNOW SHOWERS
WILL BE POSSIBLE OVERNIGHT WITH THE BEST CHANCE CONFINED TO SOUTH
CENTRAL KANSAS. ANY ACCUMULATIONS SHOULD BE LIGHT AND LESS THAN AN
INCH. CLOUDS THEN DECREASE IN COVERAGE FROM NORTH TO SOUTH
WEDNESDAY MORNING WITH MOSTLY CLEAR SKIES EXPECTED BY WEDNESDAY
EVENING. THE REMAINDER OF THE EXTENDED FORECAST LOOKS DRY AS UPPER
LEVEL RIDGING BUILDS ACROSS THE WESTERN UNITED STATES WITH A
TROUGH SHIFTING EASTWARD INTO THE EASTERN UNITED STATES. A FEW
WEAK SHORTWAVES LOOK TO MOVE THROUGH THIS FLOW LATER IN THE WEEK
BUT ONLY IMPACT WESTERN KANSAS WITH A WIND SHIFT FROM SOUTHWEST TO
NORTHWEST, THEN QUICKLY BACK TO SOUTHWEST. SKIES WILL GENERALLY BE
MOSTLY CLEAR WEDNESDAY AFTERNOON INTO THIS WEEKEND WITH A GRADUAL
WARMING TREND. HIGHS LOOK TO INCREASE FROM THE UPPER 30S WEDNESDAY
TO LOWER 50S FRIDAY INTO THIS WEEKEND. LOWS LOOK TO DIP INTO THE
UPPER TEENS WEDNESDAY AND THURSDAY MORNING RISING INTO THE 20`S
AND POSSIBLY AROUND 30 DEGREES BY THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM CST MON JAN 12 2015
LIGHT EAST/NORTHEAST WINDS WILL GRADUALLY SHIFT TO THE SOUTHEAST
EARLY TUESDAY MORNING AS A SURFACE RIDGE AXIS MOVES EAST ACROSS
EASTERN KANSAS AND A WEAK SURFACE TROUGH OF LOW PRESSURE BEGINS TO
DEVELOP OVER EASTERN COLORADO. SCATTERED FLURRIES WILL MOVE NORTH
ACROSS WEST CENTRAL AND EVEN PORTIONS OF NORTH CENTRAL KANSAS
BETWEEN 06Z AND 12Z TUESDAY AS AN AREA OF 800MB TO 600MB MOISTURE
AND WEAK LIFT MOVES NORTH TOWARDS THE NEBRASKA BORDER BASED ON
THE RAP I300 TO I308 ISENTROPIC SURFACES. A PERIOD OF MVFR
CEILINGS AND VISIBILITIES WILL ALSO BE POSSIBLE WITH THESE
FLURRIES/LIGHT SNOW EARLY THIS MORNING, MAINLY AT NEAR AND
WEST/NORTHWEST OF GCK AND HYS. OUTSIDE THESE FLURRIES CEILINGS
OVERNIGHT ARE EXPECTED TO RANGE FROM 4000FT TO 8000FT AGL BASED ON
BUFR SOUNDINGS. MVFR CEILINGS WILL BEGIN TO SPREAD FROM SOUTHWEST
TO NORTHEAST ACROSS WESTERN KANSAS BETWEEN 15Z AND 18Z TUESDAY AND
THE PREVAILING SURFACE WINDS WILL BE SOUTHEAST AT 10 KNOTS OR LESS
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 10 28 18 37 / 20 20 40 10
GCK 10 28 17 38 / 30 20 20 10
EHA 14 33 20 40 / 20 20 30 10
LBL 12 31 19 39 / 20 20 30 10
HYS 6 26 16 35 / 10 20 20 10
P28 10 29 19 37 / 10 10 30 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURKE
LONG TERM...HOVORKA_42
AVIATION...BURGERT
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1047 PM CST Mon Jan 12 2015
.UPDATE:
Issued at 1018 PM CST Mon Jan 12 2015
Not much change to going forecast. Did increase sky cover for
southwest Illinois for lingering stratus. RAP 950 hPa moisture
does suggest what lingering stratus remains to try and advect
east/southeast across Mississippi River. Otherwise...a cold/dry
night is in store with coldest conditions across northeast
Missouri and west-central Illinois where some snow cover resides.
Gosselin
&&
.SHORT TERM: (Through Late Tonight)
Issued at 140 PM CST Mon Jan 12 2015
Tranquil but cold weather expected tonight as the Arctic high
continues to settle into the MS Valley. Low clouds will continue
to clear from north to south through the remainder of the afternoon
into the early evening, while high clouds spread in from the
Plains later tonight. The coldest temps near zero should be found
in far northeast MO where there is 1-2 inches of snow cover.
Glass
.LONG TERM: (Tuesday through Next Monday)
Issued at 140 PM CST Mon Jan 12 2015
The expansive Arctic high will continue to dominate Tuesday and
Tuesday night and will even have some ramifications on Wednesday.
Continued cold and below average temperatures are expected in this
time frame. Things get a little more interesting on Wednesday. A
short wave trof currently over Alberta is forecast to dig
southeastward through the MS Valley region. This will initially
spread extensive high and mid clouds across the area on Tuesday
night and could end up producing some light snow across parts of
the area Wednesday. The latest model runs are a little more
robust with this wave than 24 hours ago, and it is accompanied by
relatively weak large scale ascent and weak mid level frontogenesis.
The negative factor is the dry low levels associated with the
Arctic high pressure which still has a southwest extension across
the area on Wednesday. The overall forcing/ascent with this wave
appear a bit weak to overcome the dry levels per current model
forecast soundings, but should the overall pattern of lift become
stronger or perhaps a narrow region of greater ascent materialize,
then some light snow is quite possible. At this point this would
seem most favored somewhere across central and northeast MO; certainly
the threat appears enough to add slight chance pops into the forecast.
I have kept with a chance of flurries elsewhere and extended them
into Wednesday night across eastern MO into southern IL.
If you like warmer weather than you should like the extended
forecast. Heights rise during the later part of the week in the
wake of this departing short wave trof and in association with
ridging building in from the Plains. The overall flow regime
becomes quasi-zonal in nature and is much flatter than we have
seen in quite some time. A nice temperature moderation/warm-up
will occur as a result with above normal highs into the 40s/lower
50s by Friday and Saturday.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Tuesday Night)
Issued at 1024 PM CST Mon Jan 12 2015
Strong surface high pressure centered over MN, western WI and
northwest IA will continue to build southeastward through MO and
IL. N-nely surface wind will veer around to a nely direction
Tuesday morning, then become light Tuesday evening. The models
depict some shallow moisture in the surface/boundary layer
late tonight/early Tuesday morning, but am not expecting stratus
clouds to develop. The stratus clouds across southern and eastern
portions of IL will continue to advect southwestward and may
impact the St Louis metro area tafs, particularly CPS late
tonight/early Tuesday morning as the low level flow comes around
to an e-nely direction late tonight. High level cloudiness will
spread into the region Tuesday and Tuesday evening.
Specifics for KSTL: N-nely surface wind will continue to gradually
weaken late tonight, then veer around to a nely direction Tuesday
morning. Stratus clouds around 2000-3000 feet in height across
southern and eastern IL was advecting southwestward, and may
briefly impact STL late tonight/early Tuesday morning, although
most of the low level clouds should remain southeast of STL.
High level clouds will spread into STL Tuesday and Tuesday night.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1021 PM CST Mon Jan 12 2015
.UPDATE:
Issued at 1018 PM CST Mon Jan 12 2015
Not much change to going forecast. Did increase sky cover for
southwest Illinois for lingering stratus. RAP 950 hPa moisture
does suggest what lingering stratus remains to try and advect
east/southeast across Mississippi River. Otherwise...a cold/dry
night is in store with coldest conditions across northeast
Missouri and west-central Illinois where some snow cover resides.
Gosselin
&&
.SHORT TERM: (Through Late Tonight)
Issued at 140 PM CST Mon Jan 12 2015
Tranquil but cold weather expected tonight as the Arctic high
continues to settle into the MS Valley. Low clouds will continue
to clear from north to south through the remainder of the afternoon
into the early evening, while high clouds spread in from the
Plains later tonight. The coldest temps near zero should be found
in far northeast MO where there is 1-2 inches of snow cover.
Glass
.LONG TERM: (Tuesday through Next Monday)
Issued at 140 PM CST Mon Jan 12 2015
The expansive Arctic high will continue to dominate Tuesday and
Tuesday night and will even have some ramifications on Wednesday.
Continued cold and below average temperatures are expected in this
time frame. Things get a little more interesting on Wednesday. A
short wave trof currently over Alberta is forecast to dig
southeastward through the MS Valley region. This will initially
spread extensive high and mid clouds across the area on Tuesday
night and could end up producing some light snow across parts of
the area Wednesday. The latest model runs are a little more
robust with this wave than 24 hours ago, and it is accompanied by
relatively weak large scale ascent and weak mid level frontogenesis.
The negative factor is the dry low levels associated with the
Arctic high pressure which still has a southwest extension across
the area on Wednesday. The overall forcing/ascent with this wave
appear a bit weak to overcome the dry levels per current model
forecast soundings, but should the overall pattern of lift become
stronger or perhaps a narrow region of greater ascent materialize,
then some light snow is quite possible. At this point this would
seem most favored somewhere across central and northeast MO; certainly
the threat appears enough to add slight chance pops into the forecast.
I have kept with a chance of flurries elsewhere and extended them
into Wednesday night across eastern MO into southern IL.
If you like warmer weather than you should like the extended
forecast. Heights rise during the later part of the week in the
wake of this departing short wave trof and in association with
ridging building in from the Plains. The overall flow regime
becomes quasi-zonal in nature and is much flatter than we have
seen in quite some time. A nice temperature moderation/warm-up
will occur as a result with above normal highs into the 40s/lower
50s by Friday and Saturday.
Glass
&&
.AVIATION: (For the 00z TAFs through 00z Tuesday Evening)
Issued at 501 PM CST Mon Jan 12 2015
Strong surface high pressure centered over the eastern Dakotas
and MN will build southeastward into MO and IL. Nly surface winds
will gradually weaken tonight, and veer around to a nely direction
Tuesday morning. The models depict some shallow moisture in the
surface/boundary layer tonight, but am not expecting stratus
clouds to develop. Will have to watch for the possibility of the
stratus clouds across southern IL to advect southwestward into
CPS though as the low level flow comes around to an e-nely
direction tonight. High level cloudiness will spread into the
region on Tuesday.
Specifics for KSTL: Gusty nly surface winds will gradually weaken
tonight, then veer around to a nely direction Tuesday morning.
Stratus clouds around 2000 feet across southern IL was advecting
southwestward, but will likely remain southwest of STL tonight.
High level clouds will spread into STL Tuesday morning.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS GREAT FALLS MT
930 PM MST Mon Jan 12 2015
Updated Aviation Discussion
.UPDATED...
Update forthcoming. Have adjusted hourly temperatures again to
better define the trend. Made no other significant changes to
current forecast. Fog likely to return to portions of North Central
Montana again overnight as low levels of the atmosphere remain
moist. Models hint at diffluence aloft over southwest Montana after
midnight and have gone with low pops that area for possible snow
showers. HRRR analysis also showing some precipitation over the
southwest after midnight.
&&
.AVIATION...
UPDATED 0530Z.
Relatively weak flow aloft and at the surface persists over the
region into Tuesday morning. Broken mid-level cloud deck S of a line
from roughly KHLN to KLWT will gradually shift SE overnight with
clearing skies at SW MT terminals after midnight. Low levels remain
fairly moist/stagnant across most of Central/SW MT for potential fog
development or persistence through most of tonight. Hoenisch
&&
.PREV DISCUSSION...Issued 256 PM MST Mon Jan 12 2015
Monday through Wednesday...Clearing skies as the upper level ridge
begins to move into the area, however biggest problem is going to
be temperatures and fog formation tonight across much of Central
and North Central Montana. Have added patchy fog to area for the
plains of Central and North Central Montana. Temperatures are also
going to be an issue for much of the overnight period tonight.
Models consistently have significantly high forecast temperatures
overnight, however they also had significantly warmer temperatures
for today`s highs when the low level inversion was going to
break(which has not happened). Have gone with a modified
persistence/RUC13 forecast solution that seems to capture the low
level cold air well. However if winds mix out the planetary
boundary layer in the next few hours, temperatures could climb
dramatically. With nighttime cooling at the surface though the
inversion will strengthen again and the odds of mixing out the
cold air near the surface will be dramatically less. The same
pattern should play out for Tuesday and Wednesday...however it
should become increasing likely that the inversion will break with
each passing day, and once it does temperatures should be similar
to the warm weather being experienced across much of Southwest
Montana. Suk
Wednesday Night through Monday...The upper-level ridge of
high pressure will break down Wednesday night and Thursday and be
replaced with an active Pacific weather pattern for the remainder of
the forecast period. Moist westerly flow aloft coupled with
progressive shortwaves will lead to enhanced precipitation over the
mountains along the Continental Divide, windy conditions along and
areas adjacent to the Rocky Mountain Front, drier and milder
conditions over the plains. Long-range forecast models continue to
highlight differences in the timing of each shortwave as well as
precipitation coverage/amounts, however forecast confidence in the
overall pattern change continues to increase. Have kept temperatures
slightly above seasonal averages Thursday through Saturday and then
around seasonal averages for the latter half of the weekend into
early next week. Though the best precipitation chances will be in
the mountains where PoPs were increased to likely, mainly dry
conditions are expected over the plains through Friday. Beginning
Friday night, have increased PoPs to slight chance for lower
elevations as a series of stronger weather systems is expected to
bring a chance for rain and snow. As mentioned prior, forecast
confidence is low regarding precipitation coverage and amounts for
lower elevations and moderate for accumulating mountain snow. Windy
conditions, perhaps high winds 58 mph or greater along the Rocky
Mountain Front and adjacent plains are also possible at times
through the forecast period. MLV
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF -2 33 19 38 / 10 0 0 0
CTB -2 31 17 34 / 0 0 10 0
HLN 15 29 14 30 / 20 10 10 10
BZN 16 28 8 29 / 10 20 10 0
WEY 10 29 2 28 / 30 20 10 0
DLN 21 32 15 33 / 20 20 10 0
HVR -12 25 13 30 / 0 0 0 10
LWT 6 33 16 42 / 10 10 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
www.twitter.com/NWSGreatFalls
www.facebook.com/NWSGreatFalls
AREA FORECAST DISCUSSION...UPDATED
NWS GREAT FALLS MT
905 PM MST Mon Jan 12 2015
.UPDATED...
Update forthcoming. Have adjusted hourly temperatures again to
better define the trend. Made no other significant changes to
current forecast. Fog likely to return to portions of North Central
Montana again overnight as low levels of the atmosphere remain
moist. Models hint at diffluence aloft over southwest Montana after
midnight and have gone with low pops that area for possible snow
showers. HRRR analysis also showing some precipitation over the
southwest after midnight.
&&
.AVIATION...
UPDATED 2330Z.
Restively weak flow aloft over the region with high pressure at the
surface will persist into Tuesday morning. Broken mid-level cloud
deck S of a line from roughly KHLN to KLWT will gradually shift SE
overnight with clearing skies at SW MT terminals after midnight. Low
levels remain fairly moist/stagnant across most of Central/SW MT
leading to fog development or persistence through most of tonight.
Hoenisch
&&
.PREV DISCUSSION...Issued 256 PM MST Mon Jan 12 2015
Monday through Wednesday...Clearing skies as the upper level ridge
begins to move into the area, however biggest problem is going to
be temperatures and fog formation tonight across much of Central
and North Central Montana. Have added patchy fog to area for the
plains of Central and North Central Montana. Temperatures are also
going to be an issue for much of the overnight period tonight.
Models consistently have significantly high forecast temperatures
overnight, however they also had significantly warmer temperatures
for today`s highs when the low level inversion was going to
break(which has not happened). Have gone with a modified
persistence/RUC13 forecast solution that seems to capture the low
level cold air well. However if winds mix out the planetary
boundary layer in the next few hours, temperatures could climb
dramatically. With nighttime cooling at the surface though the
inversion will strengthen again and the odds of mixing out the
cold air near the surface will be dramatically less. The same
pattern should play out for Tuesday and Wednesday...however it
should become increasing likely that the inversion will break with
each passing day, and once it does temperatures should be similar
to the warm weather being experienced across much of Southwest
Montana. Suk
Wednesday Night through Monday...The upper-level ridge of
high pressure will break down Wednesday night and Thursday and be
replaced with an active Pacific weather pattern for the remainder of
the forecast period. Moist westerly flow aloft coupled with
progressive shortwaves will lead to enhanced precipitation over the
mountains along the Continental Divide, windy conditions along and
areas adjacent to the Rocky Mountain Front, drier and milder
conditions over the plains. Long-range forecast models continue to
highlight differences in the timing of each shortwave as well as
precipitation coverage/amounts, however forecast confidence in the
overall pattern change continues to increase. Have kept temperatures
slightly above seasonal averages Thursday through Saturday and then
around seasonal averages for the latter half of the weekend into
early next week. Though the best precipitation chances will be in
the mountains where PoPs were increased to likely, mainly dry
conditions are expected over the plains through Friday. Beginning
Friday night, have increased PoPs to slight chance for lower
elevations as a series of stronger weather systems is expected to
bring a chance for rain and snow. As mentioned prior, forecast
confidence is low regarding precipitation coverage and amounts for
lower elevations and moderate for accumulating mountain snow. Windy
conditions, perhaps high winds 58 mph or greater along the Rocky
Mountain Front and adjacent plains are also possible at times
through the forecast period. MLV
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF -2 33 19 38 / 10 0 0 0
CTB -2 31 17 34 / 0 0 10 0
HLN 15 29 14 30 / 20 10 10 10
BZN 16 28 8 29 / 10 20 10 0
WEY 10 29 2 28 / 30 20 10 0
DLN 21 32 15 33 / 20 20 10 0
HVR -12 25 13 30 / 0 0 0 10
LWT 6 33 16 42 / 10 10 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
www.twitter.com/NWSGreatFalls
www.facebook.com/NWSGreatFalls
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1253 AM EST TUE JAN 13 2015
.SYNOPSIS...
AS STRONG ARCTIC HIGH PRESSURE BUILDS ACROSS THE NORTH COUNTRY
TONIGHT, LIGHT SNOW WILL COME TO AN END AND MUCH COLDER
TEMPERATURES WILL MOVE INTO THE REGION FOR TUESDAY AND WEDNESDAY.
HIGHS WILL RANGE FROM THE SINGLE DIGITS TO TEENS ABOVE WITH LOWS
WELL BELOW ZERO IN MANY LOCATIONS. WARMER TEMPERATURES RETURN FOR
THE END OF THE WORK WEEK, WITH DRY WEATHER CONTINUING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1213 AM EST TUESDAY...A FEW ADJUSTMENTS MADE TO FORECAST TO
ACCOUNT FOR LATEST OBSERVATIONAL DATA AND TRENDS. BAND OF LAKE
ENHANCED SNOW OFF OF LAKE CHAMPLAIN HAS PRODUCED SOME ADDITIONAL
ACCUMULATIONS OF AN INCH OR SO ACROSS PARTS OF CHITTENDEN COUNTY.
BAND SHIFTING RATHER QUICKLY TO THE SOUTHWEST INTO ADDISON COUNTY
AND STARTING TO WEAKEN AS DRIER AIR SURGES SOUTH BEHIND ARCTIC
FRONT. OVERALL TREND OF DRYING AND MUCH COLDER CONDITIONS STILL ON
TRACK FOR THE REST OF TONIGHT.
PREVIOUS DISCUSSION...
MINOR ADDITIONAL ADJUSTMENTS TO SKY COVER AND TEMPERATURE/DEWPOINT
TRENDS AS WE PROGRESS INTO THE OVERNIGHT HOURS INTO TUESDAY
MORNING. LINGERING SNOW SHOWER ACTIVITY CONTINUES HERE AND THERE
ACROSS CENTRAL AND NORTHERN COUNTIES AS OF 900 PM...ESPECIALLY IN
THE HIGHER ELEVATIONS. LITTLE ADDITIONAL ACCUMULATION IS EXPECTED
HOWEVER. ARCTIC FRONTAL BOUNDARY MAKING STEADY PROGRESS SOUTHWARD
THROUGH CENTRAL VERMONT AT THIS HOUR AND WILL CLEAR OUR SOUTHERN
COUNTIES IN THE NEXT FEW HOURS. TEMPERATURES FALLING MODESTLY
BEHIND INITIAL WIND SHIFT...BUT EVIDENCE IN THE HIGHER-RES
MODELS...INCLUDING THE 01Z RAP THAT A SECONDARY PRESSURE RISE AND
LOW LEVEL WIND SURGE WILL OCCUR BY LATE EVENING AND FORCE
TEMPERATURES SHARPLY COLDER TO BELOW ZERO IN ALL BUT FAR SOUTHERN
AREAS BY SUNRISE TUESDAY. CLASSIC ARCTIC AIRMASS AND FASCINATING
TO LOOK AT AREA SOUNDINGS SHOWING THE INCREDIBLY SHALLOW DEPTH OF
THE COLD AIR...ONLY TO ABOUT 1000 FEET OR SO. THUS HIGHER
ELEVATIONS...WHILE OBVIOUSLY TRENDING QUITE COLD TONIGHT WILL
ACTUALLY BE A TAD WARMER THAN VALLEY LOCALES LATER TONIGHT INTO
TUESDAY. WIND GUSTY INTO THE 15 TO 25 MPH RANGE OVER THE NEXT FEW
HOURS...SLOWLY ABATING LATER TONIGHT. THUS ALL WIND CHILL
HEADLINES REMAIN INTACT WITH THIS UPDATE. HAVE A GREAT NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 357 PM EST MONDAY...FOR TUESDAY THROUGH WEDNESDAY ARCTIC
HIGH BUILDS DIRECTLY OVERHEAD WITH CLEAR SKIES AND LIGHT WINDS
LEADING TO WELL BELOW NORMAL TEMPERATURES. HIGHS TUESDAY WILL
STRUGGLE TO GET BACK ABOVE ZERO FOR MUCH OF THE NORTH COUNTRY,
TOPPING OUT IN THE SINGLE DIGITS ABOVE ZERO NORTH TO LOW TEENS IN
EXTREME SOUTHERN VERMONT. WINDS WILL BE LIGHT THOUGH SO IT WON`T
BE TOO BRUTAL, AND WIND CHILLS SHOULD LOWER BELOW ADVISORY LEVELS
BY MID-MORNING. CONTINUED CLEAR SKIES AND LIGHT WINDS TUESDAY
NIGHT WILL LEAD TO EXCELLENT RADIATIONAL COOLING IN THE VALLEYS,
BUT 925-850MB TEMPS SLOWLY WARM THROUGH THE NIGHT SO WHILE
ELEVATIONS BELOW 1000FT SEE TEMPS FALL INTO TEENS TO 20S BELOW
ZERO, MID-SLOPES MAY STAY ABOVE ZERO AND THE SUMMITS MIGHT BE THE
WARM SPOT COME WEDNESDAY MORNING UNDER THIS STRONG INVERSION.
AS THE SURFACE HIGH DRIFTS OFFSHORE WEDNESDAY SOUTHERLY RETURN
FLOW WILL BRING WARMER TEMPS BACK TO THE REGION BUT STILL BELOW
NORMAL IN THE TEENS NORTH TO 20S SOUTH. LOW TEMPS WEDNESDAY NIGHT
FOLLOW SUIT AS WELL, WARMER THAN THE PREVIOUS NIGHTS BUT STILL
CHILLY IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 340 PM EST MONDAY...GENERALLY DRY WEATHER WILL CONTINUE THROUGH
THE EXTENDED FORECAST PERIOD WITH ACTIVE NORTHERN STREAM PATTERN
BUT LIMITED MOISTURE AVAILABILITY. EXTENDED PERIOD BEGINS WITH
SURFACE HIGH PRESSURE IN PLACE ON THURSDAY. AIR MASS WILL CONTINUE
MODERATING AND ANTICIPATE HIGH TEMPERATURES IN THE LOW-MID 20S
WITH LIGHT WINDS AND PARTLY CLOUDY CONDITIONS. BOTH THE 12Z ECMWF
AND GFS INDICATE THAT A SHORTWAVE TROUGH WILL MOVE EWD FROM NRN
ONTARIO AND THE NRN GREAT LAKES INTO THE NORTH COUNTRY LATE
THURSDAY NIGHT THRU FRIDAY MORNING. AN ASSOCIATED SURFACE COLD
FRONT WILL ALSO MOVE INTO THE REGION FROM THE NW...LIKELY DURING
FRIDAY MORNING. AGAIN...MOISTURE IS LIMITED...BUT LARGE-SCALE
FORCING SHOULD BE SUFFICIENT FOR SCATTERED SNOW SHOWER ACTIVITY
GENERALLY 06Z-18Z FRIDAY. MAY SEE A COATING TO 2" OF SNOWFALL WITH
THESE SNOW SHOWERS...LIKELY HIGHEST OVER THE MTNS. LOW-LEVEL COLD
ADVECTION SHOULD KEEP HIGHS IN THE LOWER 20S FRIDAY. WITH HIGH
PRESSURE BUILDING IN FROM THE WEST...LIGHT WINDS/RADIATIVE COOLING
RESULTS IN COLD TEMPS FRIDAY NIGHT (WITH LOWS IN THE SINGLE DIGITS
ABOVE ZERO). SFC ANTICYCLONE SHIFTS OFF TO THE EAST RATHER QUICKLY
SATURDAY NIGHT...SETTING UP WEAK SOUTHERLY RETURN FLOW. THIS
SHOULD ALLOW TEMPS TO CLIMB INTO THE LOW-MID 30S ON SUNDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THROUGH 06Z WEDNESDAY...COMPOSITE RADAR SHOWS ONE LONE LAKE
ENHANCED BAND OF SNOW SHOWERS ACROSS LAKE CHAMPLAIN WHICH MAY
IMPACT KRUT AS THE WINDS CONTINUE FROM THE NORTH. IT WILL PRODUCE
A VERY BRIEF PERIOD OF MVFR/IFR OF KPBG AS THE BAND SHIFTS SOUTH.
EXPECT CONDITIONS TO CONTINUE TO IMPROVE AS THE ARCTIC FRONT
CONTINUES TO PASS THROUGH THE AREA. DEW POINTS UPSTREAM ARE
SIGNIFICANTLY DRIER SO EXPECT THE BANDS OF SNOW OVER THE LAKE TO
END QUICKLY OVERNIGHT. VFR CONDITIONS WILL PREVAIL THROUGH THE
FCST PERIOD. SOME MVFR CEILINGS WILL BE POSSIBLE OVER KBTV AND
KPBG AS THE NORTH WINDS OVER THE LAKE COULD PRODUCE SOME LAKE
EFFECT CLOUDS BUT WITH A LACK OF ANY ADDITIONAL MOISTURE THERE
WILL BE NO SNOW WITH THOSE CLOUDS. THE GUSTY NORTH TO NORTHWEST
WINDS WILL CONTINUE OVERNIGHT BEFORE RELAXING UNDER HIGH PRESSURE
TOMORROW.
OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...
06Z WEDNESDAY - 00Z FRIDAY...VFR UNDER HIGH PRESSURE.
00Z FRI - 00Z SAT...MAINLY VFR ALTHOUGH A PERIOD OF MVFR/IFR
POSSIBLE IN LIGHT SNOW SHOWERS WITH NEXT COLD FRONTAL PASSAGE.
00Z SAT - 00Z SUN...HIGH PRESSURE WITH VFR CONDITIONS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
VTZ001>009-016>018.
NY...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ026>031-034-035-087.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...JMG/RJS
SHORT TERM...LAHIFF
LONG TERM...BANACOS
AVIATION...DEAL/MUCCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1219 AM EST TUE JAN 13 2015
.SYNOPSIS...
AS STRONG ARCTIC HIGH PRESSURE BUILDS ACROSS THE NORTH COUNTRY
TONIGHT, LIGHT SNOW WILL COME TO AN END AND MUCH COLDER
TEMPERATURES WILL MOVE INTO THE REGION FOR TUESDAY AND WEDNESDAY.
HIGHS WILL RANGE FROM THE SINGLE DIGITS TO TEENS ABOVE WITH LOWS
WELL BELOW ZERO IN MANY LOCATIONS. WARMER TEMPERATURES RETURN FOR
THE END OF THE WORK WEEK, WITH DRY WEATHER CONTINUING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1213 AM EST TUESDAY...A FEW ADJUSTMENTS MADE TO FORECAST TO
ACCOUNT FOR LATEST OBSERVATIONAL DATA AND TRENDS. BAND OF LAKE
ENHANCED SNOW OFF OF LAKE CHAMPLAIN HAS PRODUCED SOME ADDITIONAL
ACCUMULATIONS OF AN INCH OR SO ACROSS PARTS OF CHITTENDEN COUNTY.
BAND SHIFTING RATHER QUICKLY TO THE SOUTHWEST INTO ADDISON COUNTY
AND STARTING TO WEAKEN AS DRIER AIR SURGES SOUTH BEHIND ARCTIC
FRONT. OVERALL TREND OF DRYING AND MUCH COLDER CONDITIONS STILL ON
TRACK FOR THE REST OF TONIGHT.
PREVIOUS DISCUSSION...
MINOR ADDITIONAL ADJUSTMENTS TO SKY COVER AND TEMPERATURE/DEWPOINT
TRENDS AS WE PROGRESS INTO THE OVERNIGHT HOURS INTO TUESDAY
MORNING. LINGERING SNOW SHOWER ACTIVITY CONTINUES HERE AND THERE
ACROSS CENTRAL AND NORTHERN COUNTIES AS OF 900 PM...ESPECIALLY IN
THE HIGHER ELEVATIONS. LITTLE ADDITIONAL ACCUMULATION IS EXPECTED
HOWEVER. ARCTIC FRONTAL BOUNDARY MAKING STEADY PROGRESS SOUTHWARD
THROUGH CENTRAL VERMONT AT THIS HOUR AND WILL CLEAR OUR SOUTHERN
COUNTIES IN THE NEXT FEW HOURS. TEMPERATURES FALLING MODESTLY
BEHIND INITIAL WIND SHIFT...BUT EVIDENCE IN THE HIGHER-RES
MODELS...INCLUDING THE 01Z RAP THAT A SECONDARY PRESSURE RISE AND
LOW LEVEL WIND SURGE WILL OCCUR BY LATE EVENING AND FORCE
TEMPERATURES SHARPLY COLDER TO BELOW ZERO IN ALL BUT FAR SOUTHERN
AREAS BY SUNRISE TUESDAY. CLASSIC ARCTIC AIRMASS AND FASCINATING
TO LOOK AT AREA SOUNDINGS SHOWING THE INCREDIBLY SHALLOW DEPTH OF
THE COLD AIR...ONLY TO ABOUT 1000 FEET OR SO. THUS HIGHER
ELEVATIONS...WHILE OBVIOUSLY TRENDING QUITE COLD TONIGHT WILL
ACTUALLY BE A TAD WARMER THAN VALLEY LOCALES LATER TONIGHT INTO
TUESDAY. WIND GUSTY INTO THE 15 TO 25 MPH RANGE OVER THE NEXT FEW
HOURS...SLOWLY ABATING LATER TONIGHT. THUS ALL WIND CHILL
HEADLINES REMAIN INTACT WITH THIS UPDATE. HAVE A GREAT NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 357 PM EST MONDAY...FOR TUESDAY THROUGH WEDNESDAY ARCTIC
HIGH BUILDS DIRECTLY OVERHEAD WITH CLEAR SKIES AND LIGHT WINDS
LEADING TO WELL BELOW NORMAL TEMPERATURES. HIGHS TUESDAY WILL
STRUGGLE TO GET BACK ABOVE ZERO FOR MUCH OF THE NORTH COUNTRY,
TOPPING OUT IN THE SINGLE DIGITS ABOVE ZERO NORTH TO LOW TEENS IN
EXTREME SOUTHERN VERMONT. WINDS WILL BE LIGHT THOUGH SO IT WON`T
BE TOO BRUTAL, AND WIND CHILLS SHOULD LOWER BELOW ADVISORY LEVELS
BY MID-MORNING. CONTINUED CLEAR SKIES AND LIGHT WINDS TUESDAY
NIGHT WILL LEAD TO EXCELLENT RADIATIONAL COOLING IN THE VALLEYS,
BUT 925-850MB TEMPS SLOWLY WARM THROUGH THE NIGHT SO WHILE
ELEVATIONS BELOW 1000FT SEE TEMPS FALL INTO TEENS TO 20S BELOW
ZERO, MID-SLOPES MAY STAY ABOVE ZERO AND THE SUMMITS MIGHT BE THE
WARM SPOT COME WEDNESDAY MORNING UNDER THIS STRONG INVERSION.
AS THE SURFACE HIGH DRIFTS OFFSHORE WEDNESDAY SOUTHERLY RETURN
FLOW WILL BRING WARMER TEMPS BACK TO THE REGION BUT STILL BELOW
NORMAL IN THE TEENS NORTH TO 20S SOUTH. LOW TEMPS WEDNESDAY NIGHT
FOLLOW SUIT AS WELL, WARMER THAN THE PREVIOUS NIGHTS BUT STILL
CHILLY IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 340 PM EST MONDAY...GENERALLY DRY WEATHER WILL CONTINUE THROUGH
THE EXTENDED FORECAST PERIOD WITH ACTIVE NORTHERN STREAM PATTERN
BUT LIMITED MOISTURE AVAILABILITY. EXTENDED PERIOD BEGINS WITH
SURFACE HIGH PRESSURE IN PLACE ON THURSDAY. AIR MASS WILL CONTINUE
MODERATING AND ANTICIPATE HIGH TEMPERATURES IN THE LOW-MID 20S
WITH LIGHT WINDS AND PARTLY CLOUDY CONDITIONS. BOTH THE 12Z ECMWF
AND GFS INDICATE THAT A SHORTWAVE TROUGH WILL MOVE EWD FROM NRN
ONTARIO AND THE NRN GREAT LAKES INTO THE NORTH COUNTRY LATE
THURSDAY NIGHT THRU FRIDAY MORNING. AN ASSOCIATED SURFACE COLD
FRONT WILL ALSO MOVE INTO THE REGION FROM THE NW...LIKELY DURING
FRIDAY MORNING. AGAIN...MOISTURE IS LIMITED...BUT LARGE-SCALE
FORCING SHOULD BE SUFFICIENT FOR SCATTERED SNOW SHOWER ACTIVITY
GENERALLY 06Z-18Z FRIDAY. MAY SEE A COATING TO 2" OF SNOWFALL WITH
THESE SNOW SHOWERS...LIKELY HIGHEST OVER THE MTNS. LOW-LEVEL COLD
ADVECTION SHOULD KEEP HIGHS IN THE LOWER 20S FRIDAY. WITH HIGH
PRESSURE BUILDING IN FROM THE WEST...LIGHT WINDS/RADIATIVE COOLING
RESULTS IN COLD TEMPS FRIDAY NIGHT (WITH LOWS IN THE SINGLE DIGITS
ABOVE ZERO). SFC ANTICYCLONE SHIFTS OFF TO THE EAST RATHER QUICKLY
SATURDAY NIGHT...SETTING UP WEAK SOUTHERLY RETURN FLOW. THIS
SHOULD ALLOW TEMPS TO CLIMB INTO THE LOW-MID 30S ON SUNDAY.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
THROUGH 00Z WEDNESDAY...WIDESPREAD LIGHT SNOW WILL GRADUALLY COME
TO AN END THIS EVENING...WITH IFR/MVFR VISIBILITIES IMPROVING TO
VFR AREA-WIDE AFTER 03Z. WILL ALSO SEE THE LOWER STRATUS (MVFR
CEILINGS) GRADUALLY CLEAR...BUT LINGERING LONGEST IN AREAS OF
OROGRAPHIC ENHANCEMENT AND ALONG LAKE CHAMPLAIN DUE TO SOME LAKE-
ENHANCEMENT WITH COLD NORTHERLY FLOW. SHOULD SEE A TREND TOWARDS
CLEARING BEGINNING AT 00Z MSS...05Z-08Z PBG/RUT/MPV/SLK...AND 12Z
BTV. MAINLY CLEAR SKIES EXPECTED FOR TUESDAY...ALTHOUGH SOME
LINGERING LAKE CLOUDS STILL POSSIBLE AT BTV/PBG. GUSTY NORTHWEST
WINDS DEVELOP TONIGHT WITH GUSTS UP TO 20 KNOTS...BUT DECREASE TO
AROUND 5 KNOTS AND TURN NORTHERLY FOR TUESDAY.
OUTLOOK 00Z WEDNESDAY THROUGH SATURDAY...
00Z WEDNESDAY - 00Z FRIDAY...VFR UNDER HIGH PRESSURE.
00Z FRI - 00Z SAT...MAINLY VFR ALTHOUGH A PERIOD OF MVFR/IFR
POSSIBLE IN LIGHT SNOW SHOWERS WITH NEXT COLD FRONTAL PASSAGE.
00Z SAT - 00Z SUN...HIGH PRESSURE WITH VFR CONDITIONS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
VTZ001>009-016>018.
NY...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ026>031-034-035-087.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...JMG/RJS
SHORT TERM...LAHIFF
LONG TERM...BANACOS
AVIATION...BANACOS/MUCCILLI
AREA FORECAST DISCUSSION
NWS BISMARCK ND
323 AM CST TUE JAN 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 204 AM CST TUE JAN 13 2015
MAIN CONCERNS IN THE SHORT TERM INCLUDE THE CURRENT WIND CHILL
ADVISORY HEADLINE...CLOUDS...AND POSSIBLE LIGHT PRECIPITATION
APPROACHING THE FAR NORTH LATE TUESDAY NIGHT.
FOR TUESDAY...THE CURRENT FOG/STRATUS IMAGERY LOOP SHOWS A CLEAR
SKY OVER WESTERN AND CENTRAL NORTH DAKOTA. HOWEVER...CLOUDS IN
WESTERN/CENTRAL SOUTH DAKOTA ARE RAPIDLY APPROACHING ADAMS AND SIOUX
COUNTIES. THIS IS PICKED UP BY THE HRRR AND IS FORECAST TO MOVE
INTO FAR SOUTH CENTRAL NORTH DAKOTA AND THEN ACROSS THE SOUTHERN
JAMES RIVER VALLEY THROUGH 18Z. WITH CLOUDS FORECAST TO SLIDE
ACROSS FAR SOUTH CENTRAL EARLY THIS MORNING...A PORTION OF THE
ONGOING WIND CHILL ADVISORY WILL NEED TO BE MONITORED CLOSELY FOR
A POSSIBLE EARLY CANCELLATION PRIOR TO 16Z. OTHERWISE THE REST OF
THE WIND CHILL ADVISORY AREA LOOKS IN GOOD SHAPE THROUGH 16Z.
ANOTHER AREA OF CLOUDS LOCATED IN EASTERN MONTANA IS ALSO GETTING
CLOSER TO THE WESTERN BORDER...NEAR BEACH. SO FAR CEILINGS WITH
BOTH THE SOUTH DAKOTA AND MONTANA CLOUDS ARE AROUND 5000FT...WITH
THE TRUE STRATUS DECK FILTERING IN ACROSS SOUTHWEST SASKATCHEWAN.
WITH THAT SAID...THE LATEST WATER VAPOR IMAGERY SHOWS OUR NEXT
PAIR OF SHORTWAVE TROUGHS THAT WILL AFFECT NORTH DAKOTA. THE FIRST
WAS SLIDING THROUGH SOUTH CENTRAL SASKATCHEWAN...AND THE SECOND
WAS OVER NORTHEAST MONTANA. UNDERNEATH WAS THE REFLECTION OF A
WEAK SURFACE COLD FRONT WITH A COLD POCKET OF AIR/-4C TO -6C
REFLECTED AT 850MB. THE STRATUS PER HRRR MODEL WILL ARRIVE IN
NORTHWEST NORTH DAKOTA BETWEEN 16Z-18Z AND THEN CONTINUE INTO
CENTRAL NORTH DAKOTA BY MID AFTERNOON/EARLY EVENING. HAVE UTILIZED
A BLEND OF THE HRRR/RAP13 FOR SKY GRIDS TODAY...AND THE NAM FOR
LATE THIS AFTERNOON THROUGH TONIGHT ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. WINDS WILL SHIFT TO THE WEST/NORTHWEST WITH THE
FRONTAL PASSAGE...FOLLOWED BY THE STRATUS DECK A FEW HOURS LATER.
FOR TUESDAY NIGHT...WARM AIR ADVECTION QUICKLY RE-ESTABLISHES
ITSELF...ESPECIALLY ACROSS THE NORTH AS A WARM FRONTAL SYSTEM
SLIDES THROUGH SASKATCHEWAN. THE STRONGEST VERTICAL MOTION/OMEGA
FIELD REMAINS IN CENTRAL/EASTERN SASKATCHEWAN AND INTO WESTERN
MANITOBA FROM 06Z- 12Z WEDNESDAY. THE NAM/GFS HOLD THE
PRECIPITATION THREAT NORTH OF THE BORDER THROUGH 12Z WEDS. THE
ECMWF AND GEM ARE SLIGHTLY FASTER AND FARTHER WEST. THE GEM
PRODUCES SOME LIGHT PRECIPITATION FROM CROSBY TO AROUND SHERWOOD
BY 12Z WEDNESDAY. WITH THE SREF SHOWING THE PRECIPITATION ALSO
NORTH OF THE BORDER...HAVE PAINTED IN 14 POPS ALONG THE BORDER
TOWARD 12Z WEDS...AS THE SHORT TERM PERIOD COMES TO AN END. NOT
EXPECTING ANY WIND CHILL HEADLINES TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 204 AM CST TUE JAN 13 2015
THE EXTENDED PERIOD CONTINUES TO DISPLAY A GOOD WARMING TREND AS
MID LEVEL FLOWS STRENGTHEN AND GRADUALLY BACK FROM A NORTHWEST TO
A WESTERLY FLOW. THIS WILL BRING MODIFIED PACIFIC AIR INTO THE
NORTHERN PLAINS BEGINNING WEDNESDAY. AS THE WARMER AIR MOVES IN
THERE IS A SLIGHT CHANCE OF PRECIPITATION ALONG A WARM FRONT
MOVING THROUGH THE REGION WEDNESDAY MORNING NORTH CENTRAL. CURRENT POPS
ARE LOW (20) WITH THE NAM DRY AND THE GFS JUST SPOTTY LIGHT
PRECIP. MODEL SOUNDINGS ARE FAIRLY DRY IN THE LOW LAYERS WHICH IS
PROBLEMATIC FOR DETERMINING PRECIP TYPE. COOLING THE THERMAL
PROFILES TO THE WET BULB RESULT IN ALL SNOW. BUT BOURGOUIN PROCESS
FROM THE BUFKIT ANALYSIS WANTS TO PAINT SOME LIGHT FREEZING RAIN.
ALL IN ALL ONLY 20 POPS SO DECENT CHANCE IT WILL BE DRY AFTER ALL.
FOR NOW LEFT IF SLIGHT CHANCE FOR SNOW. THURSDAY AND FRIDAY SHOW A
NICE WARM UP INTO THE 40S SOUTHWEST TO THE 30S CENTRAL AND NORTH.
THE REMAINDER OF THE EXTENDED WILL HAVE SOME SPOTTY PRECIPITATION
WITH LOW POPS THROUGH OUT AS THE MID LEVEL FLOW OR JET STREAM
ENERGY REMAINS MODERATE TO STRONG BUT MOISTURE IS WEAK. THE RESULT
WILL BE FAST MOVING SYSTEM WITH LITTLE MOISTURE,
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 204 AM CST TUE JAN 13 2015
A WEAK COLD FRONT WILL SLIDE ACROSS THE WESTERN TERMINALS/KISN AND
KDIK BETWEEN 14Z AND 17Z TUESDAY...AND THE CENTRAL AERODROMES
KMOT/KBIS/KJMS BETWEEN 18Z AND 22Z. SATELLITE IMAGERY SHOWS AREAS OF
STRATUS LOCATED IN WESTERN SOUTH DAKOTA...EASTERN MONTANA...AND
WESTERN SASKATCHEWAN. THE MOST SIGNIFICANT THREAT FOR STRATUS SHOULD
BE WITH THE AREA NOW OVER SASKATCHEWAN WHICH MOVES INTO THE WEST BY
18Z TUESDAY AND INTO THE CENTRAL TERMINALS BETWEEN 21Z AND 03Z.
UNTIL THEN EXPECT PATCHES OF STRATUS/MVFR AND LOW VFR CIGS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ003>005-
011>013-021>023-025-035>037-046>048-050-051.
&&
$$
SHORT TERM...KS
LONG TERM...WAA
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1159 PM CST MON JAN 12 2015
.UPDATE...
ISSUED AT 1159 PM CST MON JAN 12 2015
LATEST SURFACE ANALYSIS PLACES A VERY WEAK COLD FRONT OVER WESTERN
SASKATCHEWAN INTO NORTH CENTRAL MONTANA. AN H85 COLD POCKET
ASSOCIATED WITH THE FRONTAL PASSAGE IS RELATIVELY SMALL...WEAK...AND
WILL BE SHORT LIVED AS IT SLIDES THROUGH WESTERN NORTH DAKOTA MID
MORNING TUESDAY...AND EARLY TO MID AFTERNOON IN CENTRAL NORTH DAKOTA.
THIS FRONT WILL MAINLY SERVE AS A WIND SHIFT TO THE WEST/NORTHWEST
AS IT PASSES THROUGH. THE LATEST WATER VAPOR IMAGERY SHOWS TWO
DISTINCT SHORTWAVES SUPPORTING THIS WEAK FRONT. THE FIRST WAS
MIGRATING THROUGH CENTRAL SASKATCHEWAN WITH A SECOND WAVE OVER
NORTH CENTRAL MONTANA. THESE WILL PROPAGATE EAST OVERNIGHT WITH
THE MONTANA SHORTWAVE MOVING INTO WESTERN AND CENTRAL NORTH
DAKOTA TUESDAY. LOW LEVEL WARM AIR ADVECTION AND A MOISTENING OF
THE BOUNDARY LAYER AHEAD OF THIS SYSTEM WILL LEAD TO AN INCREASE
IN CLOUDS. CURRENTLY WATCHING A FEW AREAS THAT ARE EDGING CLOSER
TO WESTERN AND SOUTH CENTRAL NORTH DAKOTA. ONE AREA WAS DEVELOPING
OVER NORTHWEST SOUTH DAKOTA...WITH A SECOND AREA IN EASTERN
MONTANA...AND THE THIRD WAS FILLING IN BEHIND THE COLD FRONT IN
WESTERN SASKATCHEWAN. THE NAM/RAP13 BUFKIT SOUNDINGS AND TO SOME
EXTENT THE HRRR CIG FORECAST PRODUCE PATCHY STRATUS AT TIMES LATER
TONIGHT INTO EARLY TUESDAY MORNING. BUT IT APPEARS THE BETTER
THREAT FOR WIDESPREAD LOW LEVEL CLOUDS WILL COME FROM THE STRATUS
IN SASKATCHEWAN TUESDAY AFTERNOON/EVENING. THE CURRENT WIND CHILL
ADVISORY REMAINS ON TRACK AT THIS TIME WITH NO CHANGES PLANNED.
REST OF FORECAST IS ALSO ON TRACK.
UPDATE ISSUED AT 920 PM CST MON JAN 12 2015
LATEST MODEL ANALYSIS CONTINUES TO SHOW LOW CLOUD COVER INCREASING
WITH WARM AIR ADVECTION LATER TONIGHT INTO TUESDAY MORNING. HAVE
AMENDED FORECAST TO REFLECT THIS. OTHERWISE...GOING FORECAST
REMAINS IN GOOD SHAPE.
UPDATE ISSUED AT 629 PM CST MON JAN 12 2015
GOING FORECAST IS IN RATHER GOOD SHAPE AS SURFACE HIGH SLOWLY
SHIFTS SOUTHEAST. MAIN CONCERN IS THE POSSIBILITY OF CLOUD/FOG
DEVELOPMENT TOWARDS TUESDAY MORNING AS WARM AIR ADVECTION
INCREASES. CURRENT FORECAST SHOWS AN INCREASE IN CLOUD COVER...BUT
THIS MAY NEED TO BE INCREASED EVEN MORE. WILL CONTINUE TO ANALYZE
NEW MODEL DATA AND THIS MAY NEED TO ADDRESSED IN SUBSEQUENT
UPDATES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 328 PM CST MON JAN 12 2015
MAIN FORECAST ISSUE WILL ONCE AGAIN BE TEMPERATURES AND RESULTING
WIND CHILLS.
CURRENTLY...ARCTIC HIGH PRESSURE CENTERED OVER SOUTHEAST NORTH
DAKOTA WILL CONTINUE TO TRACK SOUTHEAST TONIGHT. CLEAR SKIES
ACROSS ALL BUT THE FAR SOUTHWEST WHERE DIMINISHING STRATUS CLOUDS
ARE LIFTING NORTH INTO THE STATE.
TONIGHT...EXPECT A QUICK DROP IN TEMPERATURES THIS EVENING UNDER
MAINLY CLEAR SKIES. AN INCREASING SOUTHERLY FLOW SHOULD PRODUCE
WIND CHILLS INTO THE 15 TO 30 BELOW RANGE...WITH AREAS ALONG AND
EAST OF THE HIGHWAY 83 CORRIDOR INTO ADVISORY CRITERIA LONG ENOUGH
THAT WE WILL NEED ANOTHER WIND CHILL ADVISORY TONIGHT. THANKFULLY
THIS WILL WIND CHILL ADVISORY IN A WHILE. WILL START THE ADVISORY
AT 8 PM AND RUN IT THROUGH 10 AM TUESDAY.
WITH A RETURN SOUTHERLY FLOW...BOUNDARY LEVEL MOISTURE WILL BE ON
THE INCREASE TONIGHT. THIS MORNING...FOG DEVELOPED OVER AREAS OF
EASTERN MONTANA. THINK THIS IS POSSIBLE AGAIN SOMEWHERE IN WESTERN
NORTH DAKOTA TUESDAY MORNING...ESPECIALLY OVER LOW LYING AND
PROTECTED AREAS. WILL MENTION SOME PATCHY FOG WEST. TEMPERATURES
LOOK TO BOTTOM OUT SHORTLY AFTER MIDNIGHT...WITH TEMPERATURES
NEARLY STEADY EAST AND RISING WEST.
WE ARE WELL INTO THE SOUTHERLY RETURN FLOW ON TUESDAY AND
TEMPERATURES WILL REBOUND NICELY...REACHING THE 20S ACROSS THE
WEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 328 PM CST MON JAN 12 2015
WARMER TEMPERATURES WILL HIGHLIGHT THE LONG TERM FORECAST.
THE PERSISTENT GREAT LAKES LOW WILL CONTINUE TO SLOWLY SHIFT OFF
TO THE EAST. THIS WILL ALLOW EASTERN PACIFIC RIDGING TO MOVE FURTHER
EAST...EVENTUALLY MOVING ACROSS THE CENTRAL PLAINS BY THIS WEEKEND.
THIS UPPER LEVEL RIDGING WILL BRING MILD TEMPERATURES TO THE AREA.
WINDS WILL PREDOMINATELY BE OUT OF THE WEST THROUGH THE NEXT
WEEK. THIS WIND DIRECTION FAVORS DOWN SLOPING AND WILL PROVIDE
A REINFORCEMENT OF WARMER...AND DRYER AIR.
THEREFORE...TEMPERATURES THROUGH THE REST OF THE WEEK AND WEEKEND
SHOULD TOP OUT IN THE 30S FOR AFTERNOON HIGHS. SOME LOCATIONS MAY
EVEN ENTER THE 40S. INITIALLY...SNOW COVERED GROUND MAY LIMIT
HIGH TEMPERATURES EARLIER THIS WEEK. BUT WITH MOSTLY SUNNY SKIES
AND WARM AIR ADVECTION...MOST IF NOT ALL SNOW SHOULD BE MELTED BY
THE WEEKEND. OF COURSE THIS LEADS TO ITS OWN SET OF PROBLEMS AS
TEMPERATURES AT NIGHT WILL DROP INTO THE TEENS AND 20S. ICY ROADS
AND FOG MAY BECOME ISSUES LATER THIS WEEK WITH MELTING SNOW
REFREEZING AND THE BOUNDARY LAYER MOISTENING UP.
OVERALL THE WEEK LOOKS DRY. THERE ARE TWO SHORTWAVE TROUGHS FORECAST
TO SWING THROUGH SOUTHERN CANADA. AT THIS TIME IT APPEARS THEY
WILL PROVIDE NORTH DAKOTA WITH LITTLE MORE THAN CLOUD COVER.
HOWEVER...A SLIGHT JOG SOUTH AND LOCATIONS ACROSS NORTHERN NORTH
DAKOTA COULD BE IN A FAVORED LOCATION FOR SOME SNOW. OF COURSE
THESE WAVES WILL BE MONITORED AND ANALYZED IN FOLLOWING FORECAST
UPDATES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1159 PM CST MON JAN 12 2015
A WEAK COLD FRONT WILL SLIDE ACROSS THE WESTERN TERMINALS/KISN AND
KDIK BETWEEN 14Z AND 17Z TUESDAY...AND THE CENTRAL AERODROMES
KMOT/KBIS/KJMS BETWEEN 18Z AND 22Z. SATELLITE IMAGERY SHOWS AREAS OF
STRATUS LOCATED IN WESTERN SOUTH DAKOTA...EASTERN MONTANA...AND
WESTERN SASKATCHEWAN. THE MOST SIGNIFICANT THREAT FOR STRATUS SHOULD
BE WITH THE AREA NOW OVER SASKATCHEWAN WHICH MOVES INTO THE WEST BY
18Z TUESDAY AND INTO THE CENTRAL TERMINALS BETWEEN 21Z AND 03Z.
UNTIL THEN EXPECT PATCHES OF STRATUS/MVFR AND LOW VFR CIGS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST TUESDAY FOR NDZ003>005-
011>013-021>023-025-035>037-046>048-050-051.
&&
$$
UPDATE...KS
SHORT TERM...TWH
LONG TERM...AJ
AVIATION...KS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
304 AM MST TUE JAN 13 2015
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 302 AM MST TUE JAN 13 2015
LATEST WATER VAPOR IMAGERY SHOWS SOME WEAK ENERGY PASSING THROUGH
SOUTHWESTERN SOUTH DAKOTA WITH PRIMARILY ZONAL FLOW ACROSS THE
FORECAST AREA. AT THE SURFACE...HIGH PRESSURE IS OVER THE CENTRAL
PLAINS WITH A LEE TROF ACROSS EASTERN WYOMING. RADAR AND SURFACE
OBSERVATIONS INDICATE SOME LIGHT SNOW/FLURRIES ACROSS SOUTHWESTERN
SOUTH DAKOTA AND AROUND NEWCASTLE.
FOR THIS MORNING...COULD SEE SOME PATCHY FOG ACROSS PORTIONS OF
NORTHEASTERN WYOMING AND WESTERN SOUTH DAKOTA AS NAM AND RAPID
REFRESH MODEL INDICATES A SHALLOW LAYER OF MOISTURE NEAR THE
SURFACE. DON/T EXPECT FOG TO BE WIDESPREAD DUE TO THE LOW/MID LEVEL
CLOUDS CURRENTLY SPREADING ACROSS THE AREA. ALSO THE BAND OF LIGHT
SNOW/FLURRIES WILL CONTINUE TO PUSH EASTWARD FROM SOUTHWESTERN SOUTH
DAKOTA INTO SOUTH CENTRAL SOUTH DAKOTA. THUS ADDED SOME SLIGHT POPS
FOR THIS AREA THIS MORNING. OTHERWISE CLOUDS WILL DECREASE THIS
AFTERNOON FROM WEST TO EAST WITH 850-700MB WARM AIR ADVECTION IN
WESTERLY FLOW.
FOR TONIGHT...WILL SEE CLOUDS DISSIPATING EVEN MORE...BECOMING
MOSTLY CLEAR ACROSS THE AREA. LATEST HRRR AND NAM DOES INDICATE THE
POSSIBILITY OF FOG IN SOUTH CENTRAL SOUTH DAKOTA AROUND WINNER LATE
TONIGHT. HOWEVER WITH DRY AIR PUSHING IN FROM THE WEST...WILL LEAVE
IT OUT FOR NOW AND LET THE DAY SHIFT RE-EXAMINE. TEMPERATURES SHOULD
FALL TO READINGS CLOSE TO GUIDANCE VALUES IN THE UPPER SINGLE DIGITS
TO TEENS.
FOR WEDNESDAY AND WEDNESDAY NIGHT...THE WARMING TREND WILL BEGIN AS
HIGH PRESSURE BUILDS ACROSS THE WESTERN CONUS AND ROCKIES. WITH
LIMITED SKY COVER AND WESTERLY WINDS...EXPECT TEMPERATURES TO BE
NEAR TO SLIGHTLY ABOVE SEASONAL AVERAGES.
.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 302 AM MST TUE JAN 13 2015
UPPER LEVEL RIDGING SETS UP OVER THE WESTERN AND CENTRAL CONUS
FOR MUCH OF THE EXTENDED PERIOD. THIS SHOULD BRING DRY CONDITIONS
AND NEAR TO ABOVE AVERAGE TEMPERATURES TO THE AREA. BREEZY
WESTERLY WINDS WILL HELP TEMPS WARM INTO THE 40S AND LOWER 50S
THURSDAY AND FRIDAY. A COOL FRONT EARLY SATURDAY WILL REDUCE HIGHS
A BIT FOR THE WEEKEND...BUT WILL STILL BE NEAR TO ABOVE AVERAGE. A
COUPLE OF DRY SHORTWAVES MOVE THROUGH THE RIDGE DURING THE
EXTENDED PERIOD...BUT MODELS ARE HINTING AT A MORE ACTIVE PATTERN
WITH SNOW POSSIBLE EARLY NEXT WEEK.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING
ISSUED AT 302 AM MST TUE JAN 13 2015
MVFR CIGS/VSBY POSSIBLE EARLY THIS MORNING WITH ANY PATCHY FOG
THAT MAY DEVELOP...BUT FOR THE MOST PART VFR CONDITIONS ARE
EXPECTED. MID CLOUDS WILL TRANSITION EASTWARD TODAY...AND SKIES
WILL GRADUALLY CLEAR.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...MLS
LONG TERM...POJORLIE
AVIATION...POJORLIE
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
326 AM CST TUE JAN 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CST TUE JAN 13 2015
CENTER OF THE ARCTIC DOME OF HIGH PRESSURE HAS SHIFTED EAST AND
RETURN FLOW ON THE BACKSIDE OF THE HIGH HAS BEGUN TO INCREASE ACROSS
A LARGE PORTION OF THE AREA. WITH COLD DENSE AIR LINGERING AND
WINDS INCREASING...HAVE EXTENDED WIND CHILL ADVISORY ACROSS THE
EAST THROUGH 17Z.
HAVE SOME VERY SPOTTY FOG ACROSS THE AREA THIS MORNING. THE HRRR IS
NOT DOING A GOOD JOB IN PICKING THIS UP...BUT THE RAP IS SOMEWHAT
BETTER BUT MAY BE AN OVERSTATEMENT ON FOG. HAVE ADDED PATCHY
WORDING FROM NEAR SIOUX FALLS DOWN INTO NORTHWEST IOWA...BUT PATCHY
MAY BE AN OVERSTATEMENT GIVEN THE FLAKY NATURE OF THIS FOG.
OTHERWISE...FOCUS TODAY IS ON WAVE MIGRATING DOWN FROM
SASKATCHEWAN INTO MINNESOTA LATE IN THE DAY. MODELS SHOW THE
DYNAMICS SCRAPING OUR AREA...AND HAVE RAISED POPS ACCORDINGLY.
AGREE WITH PREVIOUS FORECASTER THAT SNOW AMOUNTS WILL NOT AMOUNT
TO MUCH...AS WAVE IS RELATIVELY QUICK MOVING AND SNOW SHOULD NOT
LAST IN ANY GIVEN LOCATION MORE THAN A FEW HOURS. HIGH
TEMPERATURES WILL BE WARMER THAN YESTERDAY...BUT IT WILL STILL BE
A STRUGGLE TO SHAKE THE SINGLE DIGITS IN THE EAST.
BOUNDARY MOVES THROUGH THE AREA TONIGHT...WITH WARMER AIR FOLLOWING
BEHIND THE FRONT. CLOUDS GRADUALLY CLEAR BEHIND THE WAVE LEADING TO
A BIT OF RADIATIONAL COOLING...BUT DO NOT THINK TEMPERATURES WILL
FALL MUCH WITH WARMER AIR MOVING IN. THE GREATEST COOLING WILL OCCUR
IN THE WEST WHERE CLEAR CONDITIONS WILL PERSIST LONGER THROUGH THE
NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 324 AM CST TUE JAN 13 2015
A NORTHWEST FLOW ALOFT WILL CHARACTERIZE THE REST OF THE FORECAST
WITH OCCASIONAL SHORT WAVES DIVING SOUTHEAST GRAZING THIS AREA.
WEDNESDAY FINALLY USHERS IN SOME MILDER AIR...WITH 925MB
TEMPERATURES SUGGESTING 20 TO 25 FOR HIGHS ALONG AND EAST OF
INTERSTATE 29...PROGRESSIVELY WARMING TO AROUND 30 AT CHAMBERLAIN.
AS THEY WERE YESTERDAY...BOTH THE NAM AND GFS ARE SHOWING A HINT AT
SOME STRATUS WEST OF I 29 THROUGH MIDDAY WEDNESDAY...BEFORE
EVAPORATING THE CLOUDS SOMEWHAT THROUGH THE AFTERNOON HOURS AS THEY
TRY TO PROGRESS EAST. BUT AT ANY RATE CONDITIONS LOOK DRY.
THEN A MILD AIR MASS IS IN PLACE THURSDAY AND FRIDAY WITH 925MB
TEMPERATURES WELL ABOVE FREEZING. CURRENT THOUGHTS ARE THAT IT
APPEARS THAT MANY CONSENSUS GUIDANCE VALUES ARE A LITTLE COLD FOR
OUR SOUTHWEST ZONES...EXCEPT FOR MOS VALUES. THEREFORE BLENDED IN
MOS TO GIVE GREGORY COUNTY MID 40S FOR HIGHS ON THURSDAY AND
FRIDAY...WITH THE REST OF THE FORECAST AREA IN THE 30S GOING
ISOTHERMAL FROM 925MB.
FOR THE REMAINDER OF THE FORECAST SATURDAY THROUGH MONDAY...THERE IS
THE USUAL MODEL DISCREPANCY BETWEEN THE VARIOUS DETERMINISTIC
MODELS. BUT OVERALL IT STILL LOOKS DRY NO MATTER WHAT SOLUTION IS
OUT THERE WITH MILD WEATHER CONTINUING FOR MID JANUARY STANDARDS.
SATURDAY MAY BE RATHER WINDY BEHIND A SURFACE TROUGH PASSAGE WITH
DIRECTIONS FROM THE NORTHWEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 546 PM CST MON JAN 12 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. WILL SEE AN
INCREASE IN MID LEVEL CLOUDINESS VERY LATE TONIGHT AND TUESDAY
MORNING FROM WEST TO EAST.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR SDZ038-039-
053>056-059>062-065>071.
WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR SDZ040.
MN...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ098.
WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR MNZ071-072-
080-081-089-090-097.
IA...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ001-002.
WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR IAZ003.
NE...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ013-014.
&&
$$
SHORT TERM...
LONG TERM...MJ
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
341 AM CST TUE JAN 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST TUE JAN 13 2015
AT 3 AM...A 1045 MB SURFACE HIGH WAS CENTERED OVER LA CROSSE.
TEMPERATURES EARLY THIS MORNING WERE QUITE VARIABLE. AS USUAL NORTH
CENTRAL AND CENTRAL WISCONSIN WAS THE COLDEST WITH TEMPERATURES
RANGING FROM -15 TO -25. MEANWHILE ELSEWHERE...TEMPERATURES RANGED
FROM -5 TO -15. THE WARMEST LOCATIONS TENDED TO BE ON THE RIDGE
TOPS AND THE RIVER VALLEYS WERE THE COLDEST. FOR EXAMPLE...HERE AT
THE OFFICE WE ARE -3 AND IT IS -8 AT THE AIRPORT AND -12 AT
HOLMEN. IN SOME LOCATIONS...THIS MORNING IS THE COLDEST OF THE
WINTER. FOR EXAMPLE...AUSTIN IS -15 SURPASSING -13 ON JANUARY
5TH...MEDFORD IS -19 EQUALLY -19 ON JANUARY 5TH...AND FORT MCCOY
IS -20 SURPASSING -19 ON JANUARY 6TH.
FOR TODAY...WE WILL HAVE TO WATCH THE MVFR CLOUDS ACROSS EASTERN
AND SOUTHERN WISCONSIN AND NORTHERN ILLINOIS. BOTH THE GFS AND
RAP...INDICATE THAT THESE CLOUDS WILL DISSIPATE AS THE WINDS
FLOWING OFF LAKE MICHIGAN BECOME UNFAVORABLE TO KEEP THEM
DEVELOPING AND THEY RUN INTO VERY DRY AIR OVER THE REGION.
MEANWHILE THE NAM MOVES THEM SOUTH AND AS THE WINDS TURN SOUTHERLY
IN THE WAKE OF THE HIGH...THEY MOVE NORTHWARD INTO THE AREA LATE
THIS MORNING AND AFTERNOON. AT THIS TIME...THE GFS AND RAP MAKE A
BIT MORE SENSE.
FOR TONIGHT...THE 13.00Z MODELS NORTH AMERICAN MODELS CONTINUE TO
SHOW THAT THERE WILL BE SUFFICIENT 280 TO 305K ISENTROPIC LIFT AND
900 TO 500 MB FRONTOGENESIS AHEAD OF THE SHORT WAVE...CURRENTLY
OVER SOUTHERN MANITOBA...TO QUICKLY MOISTEN UP THE AIR MASS. THE
ECWMF HAS ALSO COME AROUND TO THIS SOLUTION. THE DEEPEST MOISTURE
AND LIFT WILL BE NORTH OF INTERSTATE 90 WITH UP TO 0.03 INCHES OF
QPF BEING PRODUCED. WITH SNOW TO LIQUID RATIOS OF 13-15 TO
1...EXPECT SNOW TOTAL UP TO A HALF INCH NORTH OF INTERSTATE 90.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 340 AM CST TUE JAN 13 2015
ON WEDNESDAY...SOME LIGHT SNOW MAY LINGER ACROSS PARTS OF WESTERN
WISCONSIN THROUGH 9 AM...BUT THERE WILL BE LITTLE...IF
ANY...ADDITIONAL SNOW ACCUMULATIONS. BEHIND THIS SYSTEM...
PACIFIC AIR WILL MOVE INTO THE REGION. THIS WILL RESULT IN SLIGHT
WARMER TEMPERATURES DESPITE LESS SUNSHINE THAN TODAY.
ON WEDNESDAY NIGHT AND THURSDAY MORNING...ANOTHER SHORT WAVE
TROUGH WILL MOVE QUICKLY SOUTHEAST THROUGH THE AREA. THE BEST AND
LIFT ASSOCIATED WITH THIS WAVE STILL APPEARS TO BE MAINLY NORTH OF
THE FORECAST AREA. THE GFS IS THE ONLY MODEL THAT SHOWS ENOUGH
SATURATION TO PRODUCE SOME LIGHT SNOW NORTH OF INTERSTATE 90.
MEANWHILE THE OTHER MODELS ARE DRY.
FROM THURSDAY NIGHT INTO FRIDAY...AN ELEVATED MIXED LAYER /EML/ WILL
MOVE INTO THE AREA FROM THE HIGH PLAINS. 900 TO 850 MB
TEMPERATURES CLIMB IN THE 5 TO 7C RANGE. THESE TEMPERATURES ALOFT
WILL LIKELY CAP SOME OF THE COLDER AIR NEAR THE SURFACE. HOWEVER
THE EML WILL ALSO PRODUCE QUITE A BIT OF SUNSHINE ACROSS THE AREA
WHICH WILL HELP HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID
30S. THIS WILL BE THE WARMEST TEMPERATURES SINCE JANUARY 4TH.
FROM SUNDAY INTO MONDAY...THE MODELS CONTINUE TO SHOW THAT A
CANADIAN FRONT WILL MOVE SOUTH INTO THE AREA. THE COLDEST AIR
MASS WILL BE NORTH AND EAST OF THE FORECAST AREA. THE GFS CONTINUE
TO BE ABOUT 5 TO 10 DEGREES COLDER THAN THE ECMWF. DUE TO THESE
DIFFERENCE JUST STAYED WITH THE MODEL CONSENSUS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1115 PM CST MON JAN 12 2015
A RIDGE OF HIGH PRESSURE HAS SETTLED IN ACROSS THE REGION AND WILL
KEEP SKIES CLEAR WITH WINDS LIGHT OVERNIGHT. AS IT SHIFTS SOUTH ON
TUESDAY...WINDS WILL COME AROUND TO BEING OUT OF THE SOUTH AHEAD
OF THE NEXT SYSTEM THAT WILL APPROACH THE REGION TUESDAY NIGHT
INTO WEDNESDAY. MID LEVEL CLOUDS WILL MOVE IN TUESDAY EVENING WITH
ANY SNOW POTENTIALLY COMING IN AFTER MIDNIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1008 PM MST MON JAN 12 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 300 PM MST MON JAN 12 2015
WIDESPREAD LOW CLOUDS WILL PERSIST OVERNIGHT ESPECIALLY EAST OF
THE MTNS WHERE WEAK LOW LEVEL UPSLOPE FLOW WILL EXIST ON THE
WESTERN PERIPHERY OF A COLD SFC HIGH SETTLING SOUTHEAST OVER THE
NORTHERN PLAINS. MEANWHILE AN UPPER SHORTWAVE WILL DROP SSE ACROSS
UTAH OVERNIGHT AND OVER AZ BY LATE TUESDAY. THIS MAY PASS CLOSE
ENOUGH TO BRING SOME LIGHT SNOW OVER FAR WESTERN PARTS OF THE CWA
INTO TUESDAY MORNING WITH A FEW FLURRIES FARTHER EAST. FOG LIKELY
TO HANG ON AROUND THE CHEYENNE AREA FOR MUCH OF THE NIGHT...UNTIL
WINDS SHIFT AROUND TO WESTERLY LATE.
MILDER TEMPS EXPECTED TO SPREAD EASTWARD TUESDAY AS THE COLD SFC
AIRMASS RETREATS. A FEW SNOW SHOWERS STILL POSSIBLE MAINLY OVER
THE MTNS UNTIL A NORTHERN STREAM SHORTWAVE PASSES ACROSS LATE IN
THE DAY LEAVING A NNW FLOW ALOFT OVER THE AREA TUESDAY NIGHT
THROUGH WEDS NIGHT. SKIES SHOULD BEGIN TO CLEAR OVER NRN PARTS OF
THE CWA TUESDAY AFTERNOON AND THE REST OF THE CWA TUESDAY NIGHT.
THIS WILL ALLOW TEMPS TO FALL TO QUITE COOL LEVELS BY WEDS MORNING
GIVEN LIGHT WINDS AND SNOW COVER OVER MANY AREAS. MILDER AND DRY
WEATHER SETTLING IN FOR WEDS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 300 PM MST MON JAN 12 2015
A TRANSITION TO A WARMER AND WINDIER PATTERN WILL OCCUR FOR MUCH
OF THE EXTENDED PERIOD. THE LLVL CAG-CPR GRADIENT WILL INCREASE ON
THURS TO AROUND 45 METERS AND THEN FURTHER TO AROUND 55 METERS BY
FRI. THUS...WILL BEGIN TO SEE WEST WINDS PICK UP IN THE WIND PRONE
AREAS OF SOUTHEAST WY ESPECIALLY BY FRI. AT THIS POINT THE
GRADIENTS DO NOT SUGGEST A WIDESPREAD OR HIGH INTENSITY WIND EVENT
OVER THE WIND PRONE AREAS. 700MB TEMPS ARE 1-3C WHICH TRANSLATES
INTO HIGHS IN THE MID TO UPPER 40S FOR AREAS TO THE EAST OF THE
LARAMIE RANGE. A SHORTWAVE TROUGH WILL PUSH ACROSS THE DAKOTAS ON
SAT. WITH COOLING ALOFT...LLVL LAPSE RATES AND MIXING WILL BE
BETTER SO SAT COULD BE A WINDIER DAY STRETCHING INTO THE WESTERN
NEBRASKA PANHANDLE. ANOTHER PROGRESSIVE SHORTWAVES MOVES ACROSS
THE CANADIAN BORDER ON SUNDAY. PRECIP CHANCES THROUGH SUNDAY WILL
BE QUITE MINIMAL AS THE BEST PACIFIC MOISTURE IN THE ZONAL FLOW
ALOFT WILL REMAIN LARGELY NORTH OF THE CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 953 PM MST MON JAN 12 2015
LATEST HRRR FORECAST USED AS GUIDANCE ON THE 06Z TAFS. IFR/LIFR TO
CONTINUE FOR KCYS UNTIL THE WINDS SHIFT WEST. THAT DOES NOT LOOK
TO HAPPEN UNTIL MAYBE MID MORNING TUESDAY. KRWL LOOING AT A
WIDESPREAD IFR EVENT OUT THERRE THROUGH THE OVERNIGHT HOURS AS
WELL. ELSEWHERE...MVFR/VFR CONDITIONS SHOULD PERSIST. VFR
EVERYWHERE BY LATE MORNING AS WINDS TURN WESTERLY.
&&
.FIRE WEATHER...
ISSUED AT 228 PM MST MON JAN 12 2015
SEE NO SIGNIFICANT CONCERNS THROUGH THE WEEK WITH FACTORS MOSTLY
NON-CRITICAL. GUSTY WINDS LOOK TO DEVELOP AROUND THE SE WY MTNS
LATER IN THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RE
LONG TERM...ZF
AVIATION...GCC
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
902 AM MST TUE JAN 13 2015
.SYNOPSIS...
A WEATHER SYSTEM WILL AFFECT THE REGION TODAY THROUGH WEDNESDAY
AFTERNOON BRINGING A CHANCE FOR SHOWERS ACROSS PORTIONS OF CENTRAL
ARIZONA. BEHIND THIS SYSTEM...MUCH DRIER AIR AND LOCALLY BREEZY
CONDITIONS WILL FILTER SOUTH INTO THE AREA. HOWEVER AFTER THIS
SYSTEM PASSES...HIGH PRESSURE WILL RETURN WITH SLOWLY INCREASING
TEMPERATURES THROUGH THE WEEKEND.
&&
.DISCUSSION...
THE INCOMING SHORTWAVE TROUGH CONTINUES TO MARCH SOUTH AND THE MAIN
VORT MAX IS NOW ENTERING EXTREME NORTHWEST ARIZONA. MODEST
FRONTOGENETICAL FORCING IS SEEN ALONG THE LEADING EDGE OF THE VORT
MAX STRETCHING FROM THE FOUR CORNERS AREA TO NEAR PARKER AZ. THIS
FORCING ALONG WITH DIFLUENCE ALOFT IS PROVIDING SUPPORT FOR A BAND
OF LIGHT TO MODERATE SHOWERS WHICH IS NOW JUST ENTERING NORTHERN
MARICOPA COUNTY. HAVE INCREASED POPS IN THIS AREA THROUGH THE REST
OF THE MORNING AND AS THE BAND SHIFTS SOUTHEASTWARD...AREAS FROM
NORTH PHOENIX...THE EAST VALLEY...AND GILA COUNTY WILL SEE A DECENT
SHOT OF MEASURABLE PRECIP THIS AFTERNOON. THE CURRENT FORECAST OF
HIGHLIGHTING THE BEST POPS FOR THIS AFTERNOON LOOKS TO BE RIGHT ON
TRACK AND THE SHOWERS SHOULD THEN JUST BE FOCUSED TO THE EAST OF
PHOENIX THIS EVENING. AFTER A DECENT BREAK IN SHOWER ACTIVITY DURING
THE OVERNIGHT HOURS...CAN EXPECT SOME DAYTIME COLD CORE SHOWERS TO
AFFECT HIGHER TERRAIN AREAS OF GILA COUNTY ON WEDNESDAY.
&&
.PREVIOUS DISCUSSION...
A RATHER VIGOROUS VORTICITY CENTER AND ASSOCIATED PV ANOMALY WERE
DIVING SOUTH ALONG THE NEVADA/UTAH BORDER EARLY THIS MORNING. JET
ENERGY ON THE WRN PERIPHERY OF THIS WAVE WAS ACTING TO PULL AN
OBJECTIVELY ANALYZED -26C H5 COLD CORE SOUTH WHILE ALSO FORCING
LARGE SCALE DIFLUENCE IN ADVANCE OF THE SHORTWAVE.
CONSEQUENTLY...EMBEDDED CELLS OF DEEPER CONVECTION AND NUMEROUS
LIGHTNING STRIKES HAVE BEEN NOTED ALONG A FRONTOGENETICAL BAND
EXTENDING THROUGH MOHAVE COUNTY DESPITE ONLY MARGINAL LAPSE RATES
AND EXTREMELY LIMITED MUCAPE. WHILE THE BULK OF DYNAMICAL ASCENT IS
SHIFTING TO THE EAST OF THE CYCLONE CENTER TOWARDS THE FOUR CORNERS
REGION (AS EVIDENCED BY A BLOSSOMING BAROCLINIC LEAF APPEARANCE ON
WV SATELLITE)...SUFFICIENT ASCENT WILL STILL EXIST NEAR THE
ADVANCING COLD CORE IMPACTING WEATHER THROUGH CNTRL ARIZONA.
OPERATIONAL MODEL DPROG/DT HAS LARGELY STEADIED IN THE PAST SEVERAL
ITERATIONS BRINGING THE CNTRL H5 COLD CORE TOWARDS CENTRAL ARIZONA
OVER THE NEXT 36 HOURS. WHILE OVERALL PWATS ARE NOT
OVERWHELMING...LINGERING MOISTURE WILL FEED INTO THE SYSTEM
CHARACTERIZED BY FRONTOGENETICAL FORCING IN THE H8-H7 LAYER AND A
CORRESPONDING NARROW REGION OF ISENTROPIC ASCENT AROUND THE 300K
LEVEL. SOME DEGREE OF DOWNSLOPING FLOW FROM THE HIGHER TERRAIN OF
NRN ARIZONA COULD BE A HINDRANCE TOWARDS MORE PROLONGED ORGANIZED
PRECIPITATION AND CONVECTIVE PROCESSES...AND HIGHER ELEVATION
LOCATIONS NORTH AND EAST OF PHOENIX NATURALLY WOULD EXPERIENCE THE
BETTER CHANCES FOR PRECIPITATION. BEST PERFORMING HIGH RESOLUTION
MODELS MATCH A CONCEPTUAL MODEL OF A NARROW BROKEN LINE OF SHOWERS
RAPIDLY PROPAGATING THROUGH THE ERN HALF OF THE CWA DURING THE
DAYLIGHT HOURS.
HAVE NOT INCLUDED ANY THUNDER MENTION IN THIS FORECAST PACKAGE GIVEN
BUFR FORECAST SOUNDINGS SUGGESTING LITTLE TO NO AVAILABLE
INSTABILITY...ALTHOUGH THE CURRENT OBSERVATIONAL RADAR/SATELLITE
TRENDS STILL INDICATE ACTIVE CONVECTIVE PROCESSES PRESENT.
OTHERWISE...THE SYSTEM IS NOT UNUSUALLY COLD OR DEEP AND
HEIGHTS/THICKNESSES ALOFT INDICATE FREEZING LEVEL REMAINING AOA 7K
FT. THEREFORE...SNOW LEVELS SHOULD REMAIN WELL ABOVE POPULATION
CENTERS/TRANSPORTATION CORRIDORS WITH ONLY A DUSTING ON THE PEAKS OF
SRN GILA COUNTY LATER TONIGHT. SOME DIURNALLY FORCED SCT RAIN/SNOW
SHOWER REDEVELOPMENT MAY BE POSSIBLE WEDNESDAY AFTERNOON WITHIN THE
COLD CORE...BUT PRIMARILY LIMITED TO THE WHITE MOUNTAINS OF ERN
ARIZONA.
OPERATIONAL AND ENSEMBLE MEMBERS ARE IN VERY GOOD AGREEMENT THAT
STRONGER ZONAL PACIFIC JET ENERGY WILL FORCE A SIGNIFICANT
DOWNSTREAM PATTERN SHIFT OVER THE WESTERN HEMISPHERE DURING THE
LATTER HALF OF THIS WEEK INTO NEXT WEEK...UNLOCKING THE PREVAILING
BLOCKED FLOW INTO A MORE PROGRESSIVE QUASI-ZONAL PATTERN. SHORTWAVE
FEATURES OVER THE CONUS WILL BE EXCLUSIVELY LOW AMPLITUDE AND
RELEGATED TO THE NORTHERN STREAM WITH FLAT RIDGING PREDOMINATING THE
SWRN REGION. AS A RESULT...ENSEMBLE GUIDANCE EXHIBITS VERY LOW
FORECAST SPREAD WITH H5 HEIGHTS OSCILLATING AROUND A 580DM RANGE AND
H8 TEMPERATURES NEAR +10C. BASED ON HISTORICAL BIASES DURING SIMILAR
PATTERN EVOLUTION...HAVE HEDGED TOWARDS THE WARMEST GUIDANCE
PACKAGES YIELDING FORECAST HIGHS AT LEAST 5F ABOVE AVERAGE. EVEN
THIS APPROACH MAY BE CONSERVATIVE GIVEN A DRY ENVIRONMENT AND
POTENTIALLY SEVERAL DAYS OF FULL INSOLATION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
FRONTAL BAND OF PRECIP IS BEGINNING TO APPROACH THE AREA AS OF 11Z.
BASED ON HRRR AND HI-RES NCEP WRFS...ANTICIPATE SHOWERS TO MAKE
THEIR WAY INTO THE PHOENIX TERMINALS BETWEEN 16Z-18Z AND LINGER
UNTIL 22Z-00Z. WHILE RAINFALL AMOUNTS WILL BE LIGHT...COULD SEE
BRIEF REDUCTIONS IN VISIBILITY BUT CONFIDENCE TOO LOW TO INCLUDE IN
TAFS. I DID...HOWEVER...BRING CEILINGS DOWN TO AROUND 4000-5000FT
COINCIDENT WITH THE FRONTAL PASSAGE EARLY THIS AFTERNOON. SHOULD BE
SHORT LIVED AND CONDITIONS SHOULD IMPROVE AROUND 00Z.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
IR SATELLITE INDICATES SOME CLOUD COVER DEVELOPING AHEAD OF THE
FRONT ACROSS SOUTHEAST CALIFORNIA. SHOULD SEE THESE 5000-6000FT
CEILINGS LINGER INTO THE LATE MORNING HOURS FOLLOWED BY GRADUAL
CLEARING THIS AFTERNOON. NO PRECIP IS EXPECTED AT EITHER SE CA SITE.
WINDS COULD BE BREEZY THIS AFTERNOON AT BLH BUT SHOULD QUIET DOWN
QUICKLY AFTER 00Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
UPPER LEVEL RIDGING WILL TAKE SHAPE ACROSS THE REGION ON THURSDAY
AND REMAIN LARGELY IN PLACE THROUGH EARLY NEXT WEEK. THIS WILL
RESULT IN INCREASED TEMPERATURES AND DECREASED HUMIDITIES BUT
NOTHING THAT WOULD APPROACH CRITICAL THRESHOLDS. WINDS THROUGH THE
PERIOD WILL BE LIGHT AND GENERALLY DIURNAL IN NATURE.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...MO
AVIATION...LEINS
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
435 AM MST TUE JAN 13 2015
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
A WEATHER SYSTEM WILL AFFECT THE REGION TODAY THROUGH WEDNESDAY
AFTERNOON BRINGING A CHANCE FOR SHOWERS ACROSS PORTIONS OF CENTRAL
ARIZONA. BEHIND THIS SYSTEM...MUCH DRIER AIR AND LOCALLY BREEZY
CONDITIONS WILL FILTER SOUTH INTO THE AREA. HOWEVER AFTER THIS
SYSTEM PASSES...HIGH PRESSURE WILL RETURN WITH SLOWLY INCREASING
TEMPERATURES THROUGH THE WEEKEND.
&&
.DISCUSSION...
A RATHER VIGOROUS VORTICITY CENTER AND ASSOCIATED PV ANOMALY WERE
DIVING SOUTH ALONG THE NEVADA/UTAH BORDER EARLY THIS MORNING. JET
ENERGY ON THE WRN PERIPHERY OF THIS WAVE WAS ACTING TO PULL AN
OBJECTIVELY ANALYZED -26C H5 COLD CORE SOUTH WHILE ALSO FORCING
LARGE SCALE DIFLUENCE IN ADVANCE OF THE SHORTWAVE.
CONSEQUENTLY...EMBEDDED CELLS OF DEEPER CONVECTION AND NUMEROUS
LIGHTNING STRIKES HAVE BEEN NOTED ALONG A FRONTOGENETICAL BAND
EXTENDING THROUGH MOHAVE COUNTY DESPITE ONLY MARGINAL LAPSE RATES
AND EXTREMELY LIMITED MUCAPE. WHILE THE BULK OF DYNAMICAL ASCENT IS
SHIFTING TO THE EAST OF THE CYCLONE CENTER TOWARDS THE FOUR CORNERS
REGION (AS EVIDENCED BY A BLOSSOMING BAROCLINIC LEAF APPEARANCE ON
WV SATELLITE)...SUFFICIENT ASCENT WILL STILL EXIST NEAR THE
ADVANCING COLD CORE IMPACTING WEATHER THROUGH CNTRL ARIZONA.
OPERATIONAL MODEL DPROG/DT HAS LARGELY STEADIED IN THE PAST SEVERAL
ITERATIONS BRINGING THE CNTRL H5 COLD CORE TOWARDS CENTRAL ARIZONA
OVER THE NEXT 36 HOURS. WHILE OVERALL PWATS ARE NOT
OVERWHELMING...LINGERING MOISTURE WILL FEED INTO THE SYSTEM
CHARACTERIZED BY FRONTOGENETICAL FORCING IN THE H8-H7 LAYER AND A
CORRESPONDING NARROW REGION OF ISENTROPIC ASCENT AROUND THE 300K
LEVEL. SOME DEGREE OF DOWNSLOPING FLOW FROM THE HIGHER TERRAIN OF
NRN ARIZONA COULD BE A HINDRANCE TOWARDS MORE PROLONGED ORGANIZED
PRECIPITATION AND CONVECTIVE PROCESSES...AND HIGHER ELEVATION
LOCATIONS NORTH AND EAST OF PHOENIX NATURALLY WOULD EXPERIENCE THE
BETTER CHANCES FOR PRECIPITATION. BEST PERFORMING HIGH RESOLUTION
MODELS MATCH A CONCEPTUAL MODEL OF A NARROW BROKEN LINE OF SHOWERS
RAPIDLY PROPAGATING THROUGH THE ERN HALF OF THE CWA DURING THE
DAYLIGHT HOURS.
HAVE NOT INCLUDED ANY THUNDER MENTION IN THIS FORECAST PACKAGE GIVEN
BUFR FORECAST SOUNDINGS SUGGESTING LITTLE TO NO AVAILABLE
INSTABILITY...ALTHOUGH THE CURRENT OBSERVATIONAL RADAR/SATELLITE
TRENDS STILL INDICATE ACTIVE CONVECTIVE PROCESSES PRESENT.
OTHERWISE...THE SYSTEM IS NOT UNUSUALLY COLD OR DEEP AND
HEIGHTS/THICKNESSES ALOFT INDICATE FREEZING LEVEL REMAINING AOA 7K
FT. THEREFORE...SNOW LEVELS SHOULD REMAIN WELL ABOVE POPULATION
CENTERS/TRANSPORTATION CORRIDORS WITH ONLY A DUSTING ON THE PEAKS OF
SRN GILA COUNTY LATER TONIGHT. SOME DIURNALLY FORCED SCT RAIN/SNOW
SHOWER REDEVELOPMENT MAY BE POSSIBLE WEDNESDAY AFTERNOON WITHIN THE
COLD CORE...BUT PRIMARILY LIMITED TO THE WHITE MOUNTAINS OF ERN
ARIZONA.
OPERATIONAL AND ENSEMBLE MEMBERS ARE IN VERY GOOD AGREEMENT THAT
STRONGER ZONAL PACIFIC JET ENERGY WILL FORCE A SIGNIFICANT
DOWNSTREAM PATTERN SHIFT OVER THE WESTERN HEMISPHERE DURING THE
LATTER HALF OF THIS WEEK INTO NEXT WEEK...UNLOCKING THE PREVAILING
BLOCKED FLOW INTO A MORE PROGRESSIVE QUASI-ZONAL PATTERN. SHORTWAVE
FEATURES OVER THE CONUS WILL BE EXCLUSIVELY LOW AMPLITUDE AND
RELEGATED TO THE NORTHERN STREAM WITH FLAT RIDGING PREDOMINATING THE
SWRN REGION. AS A RESULT...ENSEMBLE GUIDANCE EXHIBITS VERY LOW
FORECAST SPREAD WITH H5 HEIGHTS OSCILLATING AROUND A 580DM RANGE AND
H8 TEMPERATURES NEAR +10C. BASED ON HISTORICAL BIASES DURING SIMILAR
PATTERN EVOLUTION...HAVE HEDGED TOWARDS THE WARMEST GUIDANCE
PACKAGES YIELDING FORECAST HIGHS AT LEAST 5F ABOVE AVERAGE. EVEN
THIS APPROACH MAY BE CONSERVATIVE GIVEN A DRY ENVIRONMENT AND
POTENTIALLY SEVERAL DAYS OF FULL INSOLATION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
FRONTAL BAND OF PRECIP IS BEGINNING TO APPROACH THE AREA AS OF 11Z.
BASED ON HRRR AND HI-RES NCEP WRFS...ANTICIPATE SHOWERS TO MAKE
THEIR WAY INTO THE PHOENIX TERMINALS BETWEEN 16Z-18Z AND LINGER
UNTIL 22Z-00Z. WHILE RAINFALL AMOUNTS WILL BE LIGHT...COULD SEE
BRIEF REDUCTIONS IN VISIBILITY BUT CONFIDENCE TOO LOW TO INCLUDE IN
TAFS. I DID...HOWEVER...BRING CEILINGS DOWN TO AROUND 4000-5000FT
COINCIDENT WITH THE FRONTAL PASSAGE EARLY THIS AFTERNOON. SHOULD BE
SHORT LIVED AND CONDITIONS SHOULD IMPROVE AROUND 00Z.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
IR SATELLITE INDICATES SOME CLOUD COVER DEVELOPING AHEAD OF THE
FRONT ACROSS SOUTHEAST CALIFORNIA. SHOULD SEE THESE 5000-6000FT
CEILINGS LINGER INTO THE LATE MORNING HOURS FOLLOWED BY GRADUAL
CLEARING THIS AFTERNOON. NO PRECIP IS EXPECTED AT EITHER SE CA SITE.
WINDS COULD BE BREEZY THIS AFTERNOON AT BLH BUT SHOULD QUIET DOWN
QUICKLY AFTER 00Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
UPPER LEVEL RIDGING WILL TAKE SHAPE ACROSS THE REGION ON THURSDAY
AND REMAIN LARGELY IN PLACE THROUGH EARLY NEXT WEEK. THIS WILL
RESULT IN INCREASED TEMPERATURES AND DECREASED HUMIDITIES BUT
NOTHING THAT WOULD APPROACH CRITICAL THRESHOLDS. WINDS THROUGH THE
PERIOD WILL BE LIGHT AND GENERALLY DIURNAL IN NATURE.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO
AVIATION...LEINS
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
519 AM CST TUE JAN 13 2015
.SYNOPSIS...
ISSUED AT 310 AM CST TUE JAN 13 2015
SURFACE HIGH PRESSURE CENTERED NORTH OF LA CROSSE WAS PROVIDING
CLEAR SKIES AND COLD CONDITIONS OVER MOST OF THE AREA EARLY THIS
MORNING. AN AREA OF LAKE GENERATED STRATUS WITH SNOW SHOWERS WAS
EVIDENT ON FOG CHANNEL IMAGERY AND SURFACE OBSERVATIONS OVER
NORTHERN IL...WHICH HAS BEEN CREEPING WESTWARD OVER THE PAST SEVERAL
HOURS. AT 08Z...THE LEADING EDGE OF THESE CLOUDS WAS ROUGHLY FROM
SAVANNA TO KEWANEE. WEAK RADAR RETURNS AND SURFACE OBSERVATIONS
INDICATED FLURRIES HAVE REACHED AS FAR WEST AS PRINCETON IL TO
STERLING IL. TEMPERATURES VARIED WIDELY...MOSTLY IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO WHERE SKIES CLEAR...TO THE UPPER
SINGLE DIGITS AND TEENS UNDER THE CLOUD COVER AND STRONGER
NORTHERLY FLOW ACROSS THE EAST. ALOFT...A NW FLOW PREVAILED WITH A
SHORTWAVE OF INTEREST MOVING ACROSS SASKATCHEWAN AND EASTERN MT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CST TUE JAN 13 2015
TRENDS WITH TEMPERATURES AND CLOUD COVER DOMINATE THE IMMEDIATE
SHORT TERM. FOCUS THEN TURNS TO THE EFFECTS OF THE SHORTWAVE PUSHING
THROUGH LATER TONIGHT.
AS THE SURFACE HIGH CONTINUES EASTWARD...THE CURRENT SURFACE
THROUGH 925 MB EASTERLY FLOW AND TRAJECTORY OF MOISTURE OFF LAKE
MI WILL BECOME LESS FAVORABLE THIS MORNING. THIS BIG QUESTION WILL
BE HOW FAR WEST THE CLOUD FIELD ADVANCES BEFORE DISSIPATING UNDER
THE LARGELY SUBSIDENT...CONFLUENT MID LEVEL FLOW. THE ROUGH
AGREEMENT IN THE 06Z WRF AND RAP MODELED MOISTURE FIELDS IN THE
900 TO 950 MB LAYERS...THAT HAD A DECENT HANDLE ON THE CURRENT
TRENDS...INDICATE THE CLOUDS SHOULD ADVANCE TO AT LEAST THE MS
RIVER INTO EXTREME EASTERN IA TOWARD MID MORNING BEFORE THINNING
OUT ALTOGETHER BY NOON AND HAVE FOLLOWED THIS TREND. FOR
NOW...WILL HAVE FLURRIES ENDING BEFORE SUNRISE ONLY OVER NW
IL...BUT WILL WATCH RADAR AND OBSERVATIONS OBSERVATIONS CLOSELY
FOR THE POSSIBLE NEED TO CONTINUE LONGER AND POSSIBLY REACH INTO
EASTERN IA.
THROUGH THE REST OF THE DAY...MOSTLY SUNNY SKIES AND LIGHT WINDS
WILL LIMIT MIXING AND PREVIOUS FORECAST HIGHS IN THE MID TO UPPER
TEENS LOOK REASONABLE.
TONIGHT...WEAK LIFT AND MID LEVEL MOISTURE WITH THE INCOMING
SHORTWAVE SHOULD LEAD TO INCREASING CLOUDS OVERNIGHT. THE CURRENT
TIMING SUGGESTS THIS MAY NOT OCCUR UNTIL LATE OVER THE EAST...WHERE
THE LIGHT WINDS AND SNOW COVER WILL AGAIN FAVOR LOWS NEAR OR A FEW
DEGREES BELOW ZERO...WITH A RAPID DROP OFF POSSIBLE IN THE EVENING.
IN THE WEST...INCREASING CLOUDS AND AT LEAST LIGHT SW WINDS SHOULD
HOLD MINS IN THE SINGLE DIGITS ABOVE ZERO...WITH STEADY TO POSSIBLY
RISING TEMPERATURES TOWARD MORNING. THE WEAK MID LEVEL LIFT REACHES
INTO THE NORTHWEST HALF OF THE FORECAST AREA TOWARD MORNING...BUT
WITH THE DEEP LAYER OF DRY AIR AT THE SURFACE...LIKELY THROUGH AT
LEAST 800 MB...PRECIPITATION DOES NOT LOOK LIKELY. WILL MENTION
POSSIBLE FLURRIES IN THE FAR NW TOWARD SUNRISE WHERE THE LIFT
LOOKS TO BE MAXIMIZED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 310 AM CST TUE JAN 13 2015
FORECAST FOCUS ON A WELCOME WARMING TREND THROUGH THIS EXTENDED
PERIOD ALONG WITH LITTLE IF ANY PRECIPITATION.
WEDNESDAY...A WEAK UPPER LEVEL TROUGH WILL SWING THROUGH THE REGION
IN THE MORNING. HOWEVER...FORECAST SOUNDINGS INDICATE THE COLUMN IS
MOISTURE STARVED AND MODELS SUGGEST FORCING IS QUITE WEAK...SO WILL
HAVE ONLY 20 POPS. MAY BE ABLE TO SQUEEZE OUT SOME FLURRIES BUT THE
WORST CASE SCENARIO WOULD BE A DUSTING IN A FEW SPOTS. NONE OF THE
OPERATIONAL MODELS PAINT ANY QPF IN THE DVN CWA...KEEPING THE BULK
OF THE QPF TO OUR NORTH WHERE THE BETTER FORCING WILL EXIST. MAXIMUM
TEMPERATURES WILL PUSH INTO THE LOWER TO MID 20S.
THURSDAY THROUGH SATURDAY...UPPER FLOW TRANSITIONS TO A MORE ZONAL
FLOW BRINGING A MILDER PACIFIC AIRMASS INTO THE MIDWEST. THIS WILL
ALLOW FOR A WARMING TREND AND BY THE TIME WE GET TO FRIDAY AND
SATURDAY HIGH TEMPERATURES WILL BE SOARING WELL INTO THE 30S AND 40S.
MUCH OF THE SNOW ON THE GROUND WILL BE MELTED BY THEN.
SUNDAY THROUGH MONDAY...A COUPLE OF CLIPPER SYSTEMS TRACK TO OUR
NORTH WITH THE OPERATIONAL MODELS KEEPING THE BULK OF THE
PRECIPITATION NORTH OF THE DVN CWA. HOWEVER...CAN`T RULE OUT
SOMETHING SNEAKING INTO THE CWA ESPECIALLY IF THE SYSTEMS TRACK
FARTHER SOUTH THAN CURRENTLY INDICATED. BEHIND EACH STORM SYSTEM A
COLD FRONT DROPS INTO THE CWA KNOCKING OUR HIGH TEMPERATURES BACK DOWN
INTO THE 30S...BUT THE CONSENSUS MODELS MAY NOT BE COLD ENOUGH FOR
LATER SHIFTS TO MONITOR.
HAASE
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 519 AM CST TUE JAN 13 2015
A DECK OF LOW CLOUDS AND SNOW FLURRIES REACHING FROM LAKE MI WEST
TO THE MS RIVER WILL LIKELY PRODUCE A PERIOD OF MVFR CIGS EARLY
THIS MORNING AT DBQ AND MLI BEFORE DISSIPATING. THE CLOUDS WILL
ALSO REACH BRL...BUT WITH SLIGHTLY HIGHER BASES THERE...CONDITIONS
WILL LIKELY REMAIN VFR. OTHERWISE...HIGH PRESSURE OVER THE REGION
WILL PROVIDE VFR CONDITIONS TODAY THROUGH TONIGHT. ONCE THE LOW
CLOUDS DISSIPATE...SKIES WILL BE MOSTLY SUNNY TODAY WITH LIGHT
EAST TO NORTHEAST WINDS. TONIGHT...HIGH CLOUDS AHEAD OF A WEAK
UPPER LEVEL SYSTEM WILL OVERSPREAD THE REGION WITH FLURRIES
POSSIBLE TOWARD WEDNESDAY MORNING...JUST BEYOND THE CURRENT
FORECAST PERIOD.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...HAASE
AVIATION...SHEETS
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1053 AM EST TUE JAN 13 2015
.UPDATE...
ISSUED AT 1049 AM EST TUE JAN 13 2015
PRIMARY CHANGES TO THE FORECAST THIS MORNING ALREADY HINTED AT BY
OVERNIGHT FORECASTER...AS CLOUD COVER OVER NORTHERN LAKE MICHIGAN
HAS GRADUALLY PUSHED NORTH...WITH MOSTLY CLOUDY-CLOUDY SKIES
EXTENDING FROM MNM-ESC-ERY. HAVE SLOWED THE IMPROVING SKY TREND
SOMEWHAT WITH THESE LOCATIONS LIKELY TO REMAIN BELOW STRATUS FOR
MUCH OF THE DAY. THIS ALSO NECESSITATED SOME NEAR TERM TEMPERATURE
ADJUSTMENTS /UPWARD/...BUT INHERITED AFTERNOON HIGHS STILL
GENERALLY LOOK GOOD WITH PERHAPS A SMALL DOWNWARD ADJUSTMENT
NEEDED FOR THESE CLOUDY LOCATIONS. OTHERWISE...PLENTY OF SUN AND
RAPIDLY REBOUNDING TEMPERATURES EXPECTED THROUGH AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EST TUE JAN 13 2015
ALTHOUGH ARCTIC SFC HIGH PRES IS CENTERED OVER WRN WI EARLY THIS
MORNING...CLOUDS HAVE BEEN SLOW TO CLEAR OUT OF UPPER MI DURING THE
NIGHT. THIS SLOW CLEARING IS A RESULT OF WINDS JUST OFF THE SFC IN
THE STRATUS BEARING LAYER BEING SO LIGHT. LATEST RUC ANALYSIS SHOWS
CENTER OF THE 925MB HIGH PRES CIRCULATION OVER SCNTRL UPPER MI.
WITH THIS CIRCULATION DRIFTING ESE...CLEARING IS NOW PROGRESSING
FAIRLY STEADILY THRU NW AND CNTRL UPPER MI. MEANWHILE...TO THE S OF
THE 925MB CIRCULATION CENTER...E/SE FLOW OFF LAKE MI HAS BROUGHT
STRATUS N AND W TO KMNM RECENTLY. WHERE SKIES HAVE BEEN CLEAR
LONGEST...NEAR THE WI BORDER...TEMPS EARLY THIS MORNING ARE IN THE
-20 TO -25F RANGE. WHERE CLOUDS CLEAR OUT BEFORE SUNRISE...TEMPS
WILL STILL HAVE AN OPPORTUNITY TO PLUMMET.
WITH THE HIGH SHIFTING SE...STRENGTHENING LOW-LEVEL SW FLOW QUICKLY
TAKES OVER TODAY...AND THIS WILL PUSH REMAINING STRATUS OUT OF THE
FCST AREA OVER THE NEXT SEVERAL HRS. HOWEVER...WILL NEED TO WATCH
THE STRATUS THAT HAS EXPANDED OFF LAKE MI INTO ERN WI. THESE CLOUDS
AND POSSIBLY SOME FLURRIES MAY SPREAD NE FROM WI TO KESC/KISQ/KERY
TODAY. RIGHT NOW...FCST REFLECTS AN OPTIMISTIC SKY CONDITION IN THAT
AREA...BUT TRAJECTORIES ARE VERY CLOSE TO HAVING JUST ENOUGH
SOUTHERLY COMPONENT TO RESULT IN CLOUDY CONDITIONS FOR A GOOD PART
OF THE DAY ACROSS THE SE FCST AREA. OBVIOUSLY...CLOUD TRENDS WILL
NEED TO BE MONITORED THIS MORNING. ALTHOUGH TEMPS WILL REACH THE
TEENS TODAY...INCREASING WINDS WILL ADD A CHILL TO THE AIR.
TONIGHT...SHORTWAVE WILL SWING SE...REACHING THE UPPER LAKES EARLY
WED MORNING. RIBBON OF DEEP LAYER FORCING AND WAA/ISENTROPIC ASCENT
OFFERS THE POTENTIAL FOR SOME -SN TONIGHT...AND ALL MODEL GUIDANCE
HAS GENERALLY TRENDED TOWARD SHOWING MORE COVERAGE OF PCPN. HAVE
THUS RAISED POPS TO HIGH CHC ACROSS THE W HALF OVERNIGHT. WITH ONLY
MODEST ISENTROPIC ASCENT INDICATED...PCPN WILL BE ON THE LIGHT
SIDE...ONLY A DUSTING OF SNOW (LESS THAN 1 INCH). TEMPS WILL BE A
CHALLENGE TONIGHT AS MOSTLY CLEAR SKIES EARLY MAY ALLOW MORE
SHELTERED INTERIOR LOCATIONS TO DIP TO ZERO OR BELOW BEFORE CLOUDS
INCREASE. OTHERWISE...SINGLE DIGITS INTERIOR TO CLOSER TO 10F ALONG
LAKE SUPERIOR SHOULD BE THE RULE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 446 AM EST TUE JAN 13 2015
SHORTWAVE CROSSING NORTHERN ONTARIO PROPELS WEAK COLD FRONT OVER
UPR MICHIGAN WEDNESDAY MORNING. GREATEST LIFT AND MID-LEVEL MOISTURE
POINT TO LINGERING LGT SNOW IN THE MORNING OVER THE SOUTH AND EAST
CWA. LAKE EFFECT SNOW LIKELY IN THE MORNING OVER KEWEENAW WITH WNW
WINDS AND MOISTURE TO H9 WITH TEMPS AT H9 BLO -14C...PLACING MOST
OF THE MOIST LAYER WITHIN THE DGZ. SHARP INVERSION PRESENT BLO 5KFT
WILL LIMIT INTENSITY BUT COULD SEE UP TO A COUPLE INCHES OF FLUFFY
ACCUMS THROUGH MIDDAY BEFORE BACKING WINDS AND SUBSIDENCE/DRYING
DIMINISH THE LES. AWAY FM KEWEENAW...SUB H9 MOISTURE REMAINS IN WAKE
OF THE FROPA BUT IT WILL PROBABLY TRY TO AT LEAST PARTIALLY CLEAR OUT
DURING THE AFTN. MIXING TO H925 SUPPORTS HIGHS IN THE MID TEENS TO
LOW 20S.
SFC LOW SLIDING SOUTHEAST FM THE CANADIAN PRAIRIES PUSHES A WARM
FRONT TOWARD UPR LAKES ON WEDNESDAY NIGHT. MID-LEVEL MOISTURE
ADVECTION H8-H6 COULD PRODUCE PATCHY LGT SNOW OVER MAINLY THE NORTH
CLOSER TO THE WARM FRONT AND WHERE SOUNDINGS SHOW GREATER SATURATION
BLO H8. SW WINDS IN WAKE OF WARM FRONT RAMP UP WITH GUSTS OVER 20
KTS NEAR LK SUPERIOR FM KEWEENAW TO NCNTRL UPR MICHIGAN. WINDS BECOME
MORE WESTERLY ON THURSDAY AND COULD BE QUITE BREEZY ON THE MORE
EXPOSED KEWEENAW PENINSULA AS SFC LOW CROSSING NORTHERN ONTARIO
DEEPENS BLO 995MB. SOUNDINGS SHOW WELL MIXED PROFILE THROUGH H9 WITH
WINDS UP TO 35 KTS. DUE TO A WELL MIXED BLYR AND ONLY MARGINAL
OVER-WATER INSTABILITY...CHANCES OF ANY LES IN WAKE OF SFC LOW SEEM
MINIMAL OVER THE KEWEENAW PENINSULA ON THURSDAY. MIXING TO 925-900MB
ON THURSDAY YIELDS MAX TEMPS INTO THE UPR 20S IF NOT LOWER 30S.
LOWEST TEMPS IN MID 20S EXPECTED DOWNSTREAM OF ICE COVERED BAY OF
GREEN BAY AND NORTHERN LK MICHIGAN.
COLDER AIR DOES FINALLY ARRIVE LATER THURSDAY NIGHT INTO FRIDAY
MORNING AS THE LOW TRACKS OVER QUEBEC. EVEN WITH H925/H85 TEMPS ON
GFS FALLING TO -18C/-16C BY 12Z ON FRIDAY OVER EASTERN LK SUPERIOR
WITH ECMWF SLIGHTLY LOWER AT H85...LES SHOULD BE DAMPENED BY DRY SUB
CLOUD LAYER AS SFC HIGH AND ANTICYCLONIC FLOW BUILD ACROSS LK
SUPERIOR FM NORTHERN ONTARIO. RAN WITH SMALL CHANCES IN NNW-NW FLOW
AREAS OF THE CNTRL AND EASTERN CWA NEAR LK SUPERIOR INTO EARLY
FRIDAY BEFORE WINDS BECOME VARIABLE AND LOSE THEIR ONSHORE
COMPONENT. FLOW LOOKS DIFFLUENT IN LOW-LEVELS OVER THE WEST...SO
KEPT CONDITIONS DRY THERE. A BIT COOLER THAN THURSDAY WITH MAX TEMPS
MOST CWA IN THE 20S.
STRONGER SHORTWAVE AND SFC LOW PRESSURE SYSTEM DIG FM THE CANADIAN
PRAIRIES ON FRIDAY NIGHT ACROSS THE FAR NORTHERN REACHES OF THE UPR
GREAT LAKES REGION ON SATURDAY. TREND FOR THIS SYSTEM IS TO DIG
FARTHER SOUTH COMPARED TO WHAT WAS SHOWN A FEW DAYS AGO WHICH MAKES
SENSE AS THE SYSTEM WILL BE DIGGING INTO OVERALL LARGER SCALE TROUGH
ALOFT. CONSENSUS POINTS TO POPS OVER MAINLY THE NORTH...INFLUENCED
IN LARGE PART BY MOSTLY DRY GFS AND WETTER ECMWF. NUDGED CHANCE POPS
FARTHER SOUTH OVER UPR MICHIGAN DUE TO THE WETTER ECMWF SOLUTION.
PTYPE COULD BE ISSUE AS WARM AIR SURGES IN ONCE MOST PRECIP TRIES TO
END. GFS/ECMWF SOUNDINGS SHOW WARM LAYER ALOFT POKING INTO THE
SCNTRL. IF ENOUGH PRECIP IS AROUND WITH ARRIVAL OF WARM LAYER COULD
SEE MIXED PRECIP ISSUES OVER MAINLY THE CNTRL AND EAST. FOR NOW KEPT
PYTPE AS SNOW...ESPECIALLY SINCE THE TREND IS FARTHER SOUTH WHICH
WOULD DRAG COOLER AIR OVER CWA. TEMPS HAVE GOOD CHANCE OF REACHING
LOW 30S OVER MUCH OF CWA ON SATURDAY. THOUGH NOT SURE HOW WE GET
THERE IN REGARD TO SATURDAY SYSTEM DETAILS...DOES APPEAR TO TURN
COOLER SUNDAY INTO MONDAY BEHIND THE LOW PRESSURE SYSTEM. POPS FOR
NW FLOW AREAS FOR LES WERE RAMPED UP OVER CONSENSUS. NO OTHER
CHANGES MADE TO WINDS/TEMPS WITH SLIGHTLY COOLER CONDITIONS
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 631 AM EST TUE JAN 13 2015
EXPECT VFR CONDITIONS INTO THE EVENING HRS AT KIWD/KCMX/KSAW AS DRY
LOW-LEVEL AIR MASS WILL BE OVER THE AREA. TIGHTENING PRES GRADIENT
WILL ALSO RESULT IN SW WINDS BECOMING GUSTY THIS AFTN...MAINLY AT
KIWD/KCMX. IT`S POSSIBLE THERE MAY BE A TRANSITION TO LLWS THIS
EVENING IF SFC WINDS CAN DECOUPLE. TONIGHT...APPROACHING DISTURBANCE
WILL BRING INCREASING CLOUDS WITH -SN/MVFR CONDITIONS LIKELY
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 446 AM EST TUE JAN 13 2015
ACTIVE LAST WEEK OF THE SHIPPING SEASON WITH STRONG WINDS AND SOME
HEAVY FREEZING SPRAY AT TIMES. SW GALES ALONG WITH HEAVY FREEZING
SPRAY IS EXPECTED THIS AFTN AND TONIGHT OVER WEST AND NCNTRL LK
SUPERIOR AHEAD OF A COLD FRONT THAT DROPS OVER THE AREA TONIGHT. GALE
WARNINGS AND HEAVY FREEZING SPRAY WARNINGS ARE IN EFFECT FOR THE
WESTERN HALF OF LK SUPERIOR. WINDS DIMINISH TO LESS THAN 20 KTS
BEHIND THE FRONT INTO WEDNESDAY. LULL IS BRIEF AS ANOTHER PERIOD OF
STRONG SW WINDS IS EXPECTED ON WED NIGHT TO THE SOUTH OF A DEEPENING
LOW PRESSURE SYSTEM OVER MANITOBA AND ONTARIO. AGAIN THE STRONGEST
WINDS WILL BE OVER WEST AND NCNTRL LK SUPERIOR. LOW WILL DEEPEN
FURTHER ON THURSDAY AS IT CROSSES JAMES BAY...RESULTING IN GOOD
CHANCE OF WESTERLY GALES 35-40 KTS OVER MUCH OF THE LAKE BY AFTN.
WINDS DIMINISH STEADILY THROUGH FRIDAY AS LOW MOVES FARTHER AWAY AND
NEW LOW PRESSURE NEARS FM THE NORTHERN PLAINS. WINDS SHOULD BECOME
SOUTH OR SOUTHEAST AHEAD OF THAT NEXT LOW. WINDS TO 30 KTS FRIDAY
NIGHT INTO SATURDAY OVER EASTERN LK SUPERIOR...THEN ALL AREAS BY
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LS...HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR
LSZ242>244-263-264.
SMALL CRAFT ADVISORY UNTIL 1 PM EST WEDNESDAY FOR LSZ242>244.
GALE WARNING UNTIL 5 AM EST WEDNESDAY FOR LSZ263-264.
LM...NONE.
&&
$$
UPDATE...ARNOTT/APX
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
632 AM EST TUE JAN 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EST TUE JAN 13 2015
ALTHOUGH ARCTIC SFC HIGH PRES IS CENTERED OVER WRN WI EARLY THIS
MORNING...CLOUDS HAVE BEEN SLOW TO CLEAR OUT OF UPPER MI DURING THE
NIGHT. THIS SLOW CLEARING IS A RESULT OF WINDS JUST OFF THE SFC IN
THE STRATUS BEARING LAYER BEING SO LIGHT. LATEST RUC ANALYSIS SHOWS
CENTER OF THE 925MB HIGH PRES CIRCULATION OVER SCNTRL UPPER MI.
WITH THIS CIRCULATION DRIFTING ESE...CLEARING IS NOW PROGRESSING
FAIRLY STEADILY THRU NW AND CNTRL UPPER MI. MEANWHILE...TO THE S OF
THE 925MB CIRCULATION CENTER...E/SE FLOW OFF LAKE MI HAS BROUGHT
STRATUS N AND W TO KMNM RECENTLY. WHERE SKIES HAVE BEEN CLEAR
LONGEST...NEAR THE WI BORDER...TEMPS EARLY THIS MORNING ARE IN THE
-20 TO -25F RANGE. WHERE CLOUDS CLEAR OUT BEFORE SUNRISE...TEMPS
WILL STILL HAVE AN OPPORTUNITY TO PLUMMET.
WITH THE HIGH SHIFTING SE...STRENGTHENING LOW-LEVEL SW FLOW QUICKLY
TAKES OVER TODAY...AND THIS WILL PUSH REMAINING STRATUS OUT OF THE
FCST AREA OVER THE NEXT SEVERAL HRS. HOWEVER...WILL NEED TO WATCH
THE STRATUS THAT HAS EXPANDED OFF LAKE MI INTO ERN WI. THESE CLOUDS
AND POSSIBLY SOME FLURRIES MAY SPREAD NE FROM WI TO KESC/KISQ/KERY
TODAY. RIGHT NOW...FCST REFLECTS AN OPTIMISTIC SKY CONDITION IN THAT
AREA...BUT TRAJECTORIES ARE VERY CLOSE TO HAVING JUST ENOUGH
SOUTHERLY COMPONENT TO RESULT IN CLOUDY CONDITIONS FOR A GOOD PART
OF THE DAY ACROSS THE SE FCST AREA. OBVIOUSLY...CLOUD TRENDS WILL
NEED TO BE MONITORED THIS MORNING. ALTHOUGH TEMPS WILL REACH THE
TEENS TODAY...INCREASING WINDS WILL ADD A CHILL TO THE AIR.
TONIGHT...SHORTWAVE WILL SWING SE...REACHING THE UPPER LAKES EARLY
WED MORNING. RIBBON OF DEEP LAYER FORCING AND WAA/ISENTROPIC ASCENT
OFFERS THE POTENTIAL FOR SOME -SN TONIGHT...AND ALL MODEL GUIDANCE
HAS GENERALLY TRENDED TOWARD SHOWING MORE COVERAGE OF PCPN. HAVE
THUS RAISED POPS TO HIGH CHC ACROSS THE W HALF OVERNIGHT. WITH ONLY
MODEST ISENTROPIC ASCENT INDICATED...PCPN WILL BE ON THE LIGHT
SIDE...ONLY A DUSTING OF SNOW (LESS THAN 1 INCH). TEMPS WILL BE A
CHALLENGE TONIGHT AS MOSTLY CLEAR SKIES EARLY MAY ALLOW MORE
SHELTERED INTERIOR LOCATIONS TO DIP TO ZERO OR BELOW BEFORE CLOUDS
INCREASE. OTHERWISE...SINGLE DIGITS INTERIOR TO CLOSER TO 10F ALONG
LAKE SUPERIOR SHOULD BE THE RULE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 446 AM EST TUE JAN 13 2015
SHORTWAVE CROSSING NORTHERN ONTARIO PROPELS WEAK COLD FRONT OVER
UPR MICHIGAN WEDNESDAY MORNING. GREATEST LIFT AND MID-LEVEL MOISTURE
POINT TO LINGERING LGT SNOW IN THE MORNING OVER THE SOUTH AND EAST
CWA. LAKE EFFECT SNOW LIKELY IN THE MORNING OVER KEWEENAW WITH WNW
WINDS AND MOISTURE TO H9 WITH TEMPS AT H9 BLO -14C...PLACING MOST
OF THE MOIST LAYER WITHIN THE DGZ. SHARP INVERSION PRESENT BLO 5KFT
WILL LIMIT INTENSITY BUT COULD SEE UP TO A COUPLE INCHES OF FLUFFY
ACCUMS THROUGH MIDDAY BEFORE BACKING WINDS AND SUBSIDENCE/DRYING
DIMINISH THE LES. AWAY FM KEWEENAW...SUB H9 MOISTURE REMAINS IN WAKE
OF THE FROPA BUT IT WILL PROBABLY TRY TO AT LEAST PARTIALLY CLEAR OUT
DURING THE AFTN. MIXING TO H925 SUPPORTS HIGHS IN THE MID TEENS TO
LOW 20S.
SFC LOW SLIDING SOUTHEAST FM THE CANADIAN PRAIRIES PUSHES A WARM
FRONT TOWARD UPR LAKES ON WEDNESDAY NIGHT. MID-LEVEL MOISTURE
ADVECTION H8-H6 COULD PRODUCE PATCHY LGT SNOW OVER MAINLY THE NORTH
CLOSER TO THE WARM FRONT AND WHERE SOUNDINGS SHOW GREATER SATURATION
BLO H8. SW WINDS IN WAKE OF WARM FRONT RAMP UP WITH GUSTS OVER 20
KTS NEAR LK SUPERIOR FM KEWEENAW TO NCNTRL UPR MICHIGAN. WINDS BECOME
MORE WESTERLY ON THURSDAY AND COULD BE QUITE BREEZY ON THE MORE
EXPOSED KEWEENAW PENINSULA AS SFC LOW CROSSING NORTHERN ONTARIO
DEEPENS BLO 995MB. SOUNDINGS SHOW WELL MIXED PROFILE THROUGH H9 WITH
WINDS UP TO 35 KTS. DUE TO A WELL MIXED BLYR AND ONLY MARGINAL
OVER-WATER INSTABILITY...CHANCES OF ANY LES IN WAKE OF SFC LOW SEEM
MINIMAL OVER THE KEWEENAW PENINSULA ON THURSDAY. MIXING TO 925-900MB
ON THURSDAY YIELDS MAX TEMPS INTO THE UPR 20S IF NOT LOWER 30S.
LOWEST TEMPS IN MID 20S EXPECTED DOWNSTREAM OF ICE COVERED BAY OF
GREEN BAY AND NORTHERN LK MICHIGAN.
COLDER AIR DOES FINALLY ARRIVE LATER THURSDAY NIGHT INTO FRIDAY
MORNING AS THE LOW TRACKS OVER QUEBEC. EVEN WITH H925/H85 TEMPS ON
GFS FALLING TO -18C/-16C BY 12Z ON FRIDAY OVER EASTERN LK SUPERIOR
WITH ECMWF SLIGHTLY LOWER AT H85...LES SHOULD BE DAMPENED BY DRY SUB
CLOUD LAYER AS SFC HIGH AND ANTICYCLONIC FLOW BUILD ACROSS LK
SUPERIOR FM NORTHERN ONTARIO. RAN WITH SMALL CHANCES IN NNW-NW FLOW
AREAS OF THE CNTRL AND EASTERN CWA NEAR LK SUPERIOR INTO EARLY
FRIDAY BEFORE WINDS BECOME VARIABLE AND LOSE THEIR ONSHORE
COMPONENT. FLOW LOOKS DIFFLUENT IN LOW-LEVELS OVER THE WEST...SO
KEPT CONDITIONS DRY THERE. A BIT COOLER THAN THURSDAY WITH MAX TEMPS
MOST CWA IN THE 20S.
STRONGER SHORTWAVE AND SFC LOW PRESSURE SYSTEM DIG FM THE CANADIAN
PRAIRIES ON FRIDAY NIGHT ACROSS THE FAR NORTHERN REACHES OF THE UPR
GREAT LAKES REGION ON SATURDAY. TREND FOR THIS SYSTEM IS TO DIG
FARTHER SOUTH COMPARED TO WHAT WAS SHOWN A FEW DAYS AGO WHICH MAKES
SENSE AS THE SYSTEM WILL BE DIGGING INTO OVERALL LARGER SCALE TROUGH
ALOFT. CONSENSUS POINTS TO POPS OVER MAINLY THE NORTH...INFLUENCED
IN LARGE PART BY MOSTLY DRY GFS AND WETTER ECMWF. NUDGED CHANCE POPS
FARTHER SOUTH OVER UPR MICHIGAN DUE TO THE WETTER ECMWF SOLUTION.
PTYPE COULD BE ISSUE AS WARM AIR SURGES IN ONCE MOST PRECIP TRIES TO
END. GFS/ECMWF SOUNDINGS SHOW WARM LAYER ALOFT POKING INTO THE
SCNTRL. IF ENOUGH PRECIP IS AROUND WITH ARRIVAL OF WARM LAYER COULD
SEE MIXED PRECIP ISSUES OVER MAINLY THE CNTRL AND EAST. FOR NOW KEPT
PYTPE AS SNOW...ESPECIALLY SINCE THE TREND IS FARTHER SOUTH WHICH
WOULD DRAG COOLER AIR OVER CWA. TEMPS HAVE GOOD CHANCE OF REACHING
LOW 30S OVER MUCH OF CWA ON SATURDAY. THOUGH NOT SURE HOW WE GET
THERE IN REGARD TO SATURDAY SYSTEM DETAILS...DOES APPEAR TO TURN
COOLER SUNDAY INTO MONDAY BEHIND THE LOW PRESSURE SYSTEM. POPS FOR
NW FLOW AREAS FOR LES WERE RAMPED UP OVER CONSENSUS. NO OTHER
CHANGES MADE TO WINDS/TEMPS WITH SLIGHTLY COOLER CONDITIONS
EXPECTED...ALTHOUGH STILL STAYING AROUND NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 631 AM EST TUE JAN 13 2015
EXPECT VFR CONDITIONS INTO THE EVENING HRS AT KIWD/KCMX/KSAW AS DRY
LOW-LEVEL AIR MASS WILL BE OVER THE AREA. TIGHTENING PRES GRADIENT
WILL ALSO RESULT IN SW WINDS BECOMING GUSTY THIS AFTN...MAINLY AT
KIWD/KCMX. IT`S POSSIBLE THERE MAY BE A TRANSITION TO LLWS THIS
EVENING IF SFC WINDS CAN DECOUPLE. TONIGHT...APPROACHING DISTURBANCE
WILL BRING INCREASING CLOUDS WITH -SN/MVFR CONDITIONS LIKELY
DEVELOPING AT ALL TERMINALS OVERNIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 446 AM EST TUE JAN 13 2015
ACTIVE LAST WEEK OF THE SHIPPING SEASON WITH STRONG WINDS AND SOME
HEAVY FREEZING SPRAY AT TIMES. SW GALES ALONG WITH HEAVY FREEZING
SPRAY IS EXPECTED THIS AFTN AND TONIGHT OVER WEST AND NCNTRL LK
SUPERIOR AHEAD OF A COLD FRONT THAT DROPS OVER THE AREA TONIGHT. GALE
WARNINGS AND HEAVY FREEZING SPRAY WARNINGS ARE IN EFFECT FOR THE
WESTERN HALF OF LK SUPERIOR. WINDS DIMINISH TO LESS THAN 20 KTS
BEHIND THE FRONT INTO WEDNESDAY. LULL IS BRIEF AS ANOTHER PERIOD OF
STRONG SW WINDS IS EXPECTED ON WED NIGHT TO THE SOUTH OF A DEEPENING
LOW PRESSURE SYSTEM OVER MANITOBA AND ONTARIO. AGAIN THE STRONGEST
WINDS WILL BE OVER WEST AND NCNTRL LK SUPERIOR. LOW WILL DEEPEN
FURTHER ON THURSDAY AS IT CROSSES JAMES BAY...RESULTING IN GOOD
CHANCE OF WESTERLY GALES 35-40 KTS OVER MUCH OF THE LAKE BY AFTN.
WINDS DIMINISH STEADILY THROUGH FRIDAY AS LOW MOVES FARTHER AWAY AND
NEW LOW PRESSURE NEARS FM THE NORTHERN PLAINS. WINDS SHOULD BECOME
SOUTH OR SOUTHEAST AHEAD OF THAT NEXT LOW. WINDS TO 30 KTS FRIDAY
NIGHT INTO SATURDAY OVER EASTERN LK SUPERIOR...THEN ALL AREAS BY
LATE SATURDAY AS WINDS BECOME WEST-NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-242>244-263-264.
GALE WARNING FROM 3 PM THIS AFTERNOON TO 5 AM EST WEDNESDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
508 AM EST TUE JAN 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EST TUE JAN 13 2015
ALTHOUGH ARCTIC SFC HIGH PRES IS CENTERED OVER WRN WI EARLY THIS
MORNING...CLOUDS HAVE BEEN SLOW TO CLEAR OUT OF UPPER MI DURING THE
NIGHT. THIS SLOW CLEARING IS A RESULT OF WINDS JUST OFF THE SFC IN
THE STRATUS BEARING LAYER BEING SO LIGHT. LATEST RUC ANALYSIS SHOWS
CENTER OF THE 925MB HIGH PRES CIRCULATION OVER SCNTRL UPPER MI.
WITH THIS CIRCULATION DRIFTING ESE...CLEARING IS NOW PROGRESSING
FAIRLY STEADILY THRU NW AND CNTRL UPPER MI. MEANWHILE...TO THE S OF
THE 925MB CIRCULATION CENTER...E/SE FLOW OFF LAKE MI HAS BROUGHT
STRATUS N AND W TO KMNM RECENTLY. WHERE SKIES HAVE BEEN CLEAR
LONGEST...NEAR THE WI BORDER...TEMPS EARLY THIS MORNING ARE IN THE
-20 TO -25F RANGE. WHERE CLOUDS CLEAR OUT BEFORE SUNRISE...TEMPS
WILL STILL HAVE AN OPPORTUNITY TO PLUMMET.
WITH THE HIGH SHIFTING SE...STRENGTHENING LOW-LEVEL SW FLOW QUICKLY
TAKES OVER TODAY...AND THIS WILL PUSH REMAINING STRATUS OUT OF THE
FCST AREA OVER THE NEXT SEVERAL HRS. HOWEVER...WILL NEED TO WATCH
THE STRATUS THAT HAS EXPANDED OFF LAKE MI INTO ERN WI. THESE CLOUDS
AND POSSIBLY SOME FLURRIES MAY SPREAD NE FROM WI TO KESC/KISQ/KERY
TODAY. RIGHT NOW...FCST REFLECTS AN OPTIMISTIC SKY CONDITION IN THAT
AREA...BUT TRAJECTORIES ARE VERY CLOSE TO HAVING JUST ENOUGH
SOUTHERLY COMPONENT TO RESULT IN CLOUDY CONDITIONS FOR A GOOD PART
OF THE DAY ACROSS THE SE FCST AREA. OBVIOUSLY...CLOUD TRENDS WILL
NEED TO BE MONITORED THIS MORNING. ALTHOUGH TEMPS WILL REACH THE
TEENS TODAY...INCREASING WINDS WILL ADD A CHILL TO THE AIR.
TONIGHT...SHORTWAVE WILL SWING SE...REACHING THE UPPER LAKES EARLY
WED MORNING. RIBBON OF DEEP LAYER FORCING AND WAA/ISENTROPIC ASCENT
OFFERS THE POTENTIAL FOR SOME -SN TONIGHT...AND ALL MODEL GUIDANCE
HAS GENERALLY TRENDED TOWARD SHOWING MORE COVERAGE OF PCPN. HAVE
THUS RAISED POPS TO HIGH CHC ACROSS THE W HALF OVERNIGHT. WITH ONLY
MODEST ISENTROPIC ASCENT INDICATED...PCPN WILL BE ON THE LIGHT
SIDE...ONLY A DUSTING OF SNOW (LESS THAN 1 INCH). TEMPS WILL BE A
CHALLENGE TONIGHT AS MOSTLY CLEAR SKIES EARLY MAY ALLOW MORE
SHELTERED INTERIOR LOCATIONS TO DIP TO ZERO OR BELOW BEFORE CLOUDS
INCREASE. OTHERWISE...SINGLE DIGITS INTERIOR TO CLOSER TO 10F ALONG
LAKE SUPERIOR SHOULD BE THE RULE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 446 AM EST TUE JAN 13 2015
SHORTWAVE CROSSING NORTHERN ONTARIO PROPELS WEAK COLD FRONT OVER
UPR MICHIGAN WEDNESDAY MORNING. GREATEST LIFT AND MID-LEVEL MOISTURE
POINT TO LINGERING LGT SNOW IN THE MORNING OVER THE SOUTH AND EAST
CWA. LAKE EFFECT SNOW LIKELY IN THE MORNING OVER KEWEENAW WITH WNW
WINDS AND MOISTURE TO H9 WITH TEMPS AT H9 BLO -14C...PLACING MOST
OF THE MOIST LAYER WITHIN THE DGZ. SHARP INVERSION PRESENT BLO 5KFT
WILL LIMIT INTENSITY BUT COULD SEE UP TO A COUPLE INCHES OF FLUFFY
ACCUMS THROUGH MIDDAY BEFORE BACKING WINDS AND SUBSIDENCE/DRYING
DIMINISH THE LES. AWAY FM KEWEENAW...SUB H9 MOISTURE REMAINS IN WAKE
OF THE FROPA BUT IT WILL PROBABLY TRY TO AT LEAST PARTIALLY CLEAR OUT
DURING THE AFTN. MIXING TO H925 SUPPORTS HIGHS IN THE MID TEENS TO
LOW 20S.
SFC LOW SLIDING SOUTHEAST FM THE CANADIAN PRAIRIES PUSHES A WARM
FRONT TOWARD UPR LAKES ON WEDNESDAY NIGHT. MID-LEVEL MOISTURE
ADVECTION H8-H6 COULD PRODUCE PATCHY LGT SNOW OVER MAINLY THE NORTH
CLOSER TO THE WARM FRONT AND WHERE SOUNDINGS SHOW GREATER SATURATION
BLO H8. SW WINDS IN WAKE OF WARM FRONT RAMP UP WITH GUSTS OVER 20
KTS NEAR LK SUPERIOR FM KEWEENAW TO NCNTRL UPR MICHIGAN. WINDS BECOME
MORE WESTERLY ON THURSDAY AND COULD BE QUITE BREEZY ON THE MORE
EXPOSED KEWEENAW PENINSULA AS SFC LOW CROSSING NORTHERN ONTARIO
DEEPENS BLO 995MB. SOUNDINGS SHOW WELL MIXED PROFILE THROUGH H9 WITH
WINDS UP TO 35 KTS. DUE TO A WELL MIXED BLYR AND ONLY MARGINAL
OVER-WATER INSTABILITY...CHANCES OF ANY LES IN WAKE OF SFC LOW SEEM
MINIMAL OVER THE KEWEENAW PENINSULA ON THURSDAY. MIXING TO 925-900MB
ON THURSDAY YIELDS MAX TEMPS INTO THE UPR 20S IF NOT LOWER 30S.
LOWEST TEMPS IN MID 20S EXPECTED DOWNSTREAM OF ICE COVERED BAY OF
GREEN BAY AND NORTHERN LK MICHIGAN.
COLDER AIR DOES FINALLY ARRIVE LATER THURSDAY NIGHT INTO FRIDAY
MORNING AS THE LOW TRACKS OVER QUEBEC. EVEN WITH H925/H85 TEMPS ON
GFS FALLING TO -18C/-16C BY 12Z ON FRIDAY OVER EASTERN LK SUPERIOR
WITH ECMWF SLIGHTLY LOWER AT H85...LES SHOULD BE DAMPENED BY DRY SUB
CLOUD LAYER AS SFC HIGH AND ANTICYCLONIC FLOW BUILD ACROSS LK
SUPERIOR FM NORTHERN ONTARIO. RAN WITH SMALL CHANCES IN NNW-NW FLOW
AREAS OF THE CNTRL AND EASTERN CWA NEAR LK SUPERIOR INTO EARLY
FRIDAY BEFORE WINDS BECOME VARIABLE AND LOSE THEIR ONSHORE
COMPONENT. FLOW LOOKS DIFFLUENT IN LOW-LEVELS OVER THE WEST...SO
KEPT CONDITIONS DRY THERE. A BIT COOLER THAN THURSDAY WITH MAX TEMPS
MOST CWA IN THE 20S.
STRONGER SHORTWAVE AND SFC LOW PRESSURE SYSTEM DIG FM THE CANADIAN
PRAIRIES ON FRIDAY NIGHT ACROSS THE FAR NORTHERN REACHES OF THE UPR
GREAT LAKES REGION ON SATURDAY. TREND FOR THIS SYSTEM IS TO DIG
FARTHER SOUTH COMPARED TO WHAT WAS SHOWN A FEW DAYS AGO WHICH MAKES
SENSE AS THE SYSTEM WILL BE DIGGING INTO OVERALL LARGER SCALE TROUGH
ALOFT. CONSENSUS POINTS TO POPS OVER MAINLY THE NORTH...INFLUENCED
IN LARGE PART BY MOSTLY DRY GFS AND WETTER ECMWF. NUDGED CHANCE POPS
FARTHER SOUTH OVER UPR MICHIGAN DUE TO THE WETTER ECMWF SOLUTION.
PTYPE COULD BE ISSUE AS WARM AIR SURGES IN ONCE MOST PRECIP TRIES TO
END. GFS/ECMWF SOUNDINGS SHOW WARM LAYER ALOFT POKING INTO THE
SCNTRL. IF ENOUGH PRECIP IS AROUND WITH ARRIVAL OF WARM LAYER COULD
SEE MIXED PRECIP ISSUES OVER MAINLY THE CNTRL AND EAST. FOR NOW KEPT
PYTPE AS SNOW...ESPECIALLY SINCE THE TREND IS FARTHER SOUTH WHICH
WOULD DRAG COOLER AIR OVER CWA. TEMPS HAVE GOOD CHANCE OF REACHING
LOW 30S OVER MUCH OF CWA ON SATURDAY. THOUGH NOT SURE HOW WE GET
THERE IN REGARD TO SATURDAY SYSTEM DETAILS...DOES APPEAR TO TURN
COOLER SUNDAY INTO MONDAY BEHIND THE LOW PRESSURE SYSTEM. POPS FOR
NW FLOW AREAS FOR LES WERE RAMPED UP OVER CONSENSUS. NO OTHER
CHANGES MADE TO WINDS/TEMPS WITH SLIGHTLY COOLER CONDITIONS
EXPECTED...ALTHOUGH STILL STAYING AROUND NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1210 AM EST TUE JAN 13 2015
LINGERING MOISTURE BELOW A STRENGTHENING INVERSION WILL HELP
MAINTAIN MVFR CIGS THROUGH AROUND 09Z AT CMX/SAW. HOWEVER...
AS HIGH PRESSURE MOVES INTO THE WRN GREAT LAKES REGION
OVERNIGHT...INCREASING SW WINDS WILL PUSH THE CLOUDS OUT OF THE
AREA....RESULTING IN IMPROVEMENT TO VFR AT ALL TERMINALS. WITH THE
HIGH SINKING TOWARD THE SRN GREAT LAKES...SW WINDS WILL INCREASE AND
BECOME GUSTY AT IWD/CMX TODAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 446 AM EST TUE JAN 13 2015
ACTIVE LAST WEEK OF THE SHIPPING SEASON WITH STRONG WINDS AND SOME
HEAVY FREEZING SPRAY AT TIMES. SW GALES ALONG WITH HEAVY FREEZING
SPRAY IS EXPECTED THIS AFTN AND TONIGHT OVER WEST AND NCNTRL LK
SUPERIOR AHEAD OF A COLD FRONT THAT DROPS OVER THE AREA TONIGHT. GALE
WARNINGS AND HEAVY FREEZING SPRAY WARNINGS ARE IN EFFECT FOR THE
WESTERN HALF OF LK SUPERIOR. WINDS DIMINISH TO LESS THAN 20 KTS
BEHIND THE FRONT INTO WEDNESDAY. LULL IS BRIEF AS ANOTHER PERIOD OF
STRONG SW WINDS IS EXPECTED ON WED NIGHT TO THE SOUTH OF A DEEPENING
LOW PRESSURE SYSTEM OVER MANITOBA AND ONTARIO. AGAIN THE STRONGEST
WINDS WILL BE OVER WEST AND NCNTRL LK SUPERIOR. LOW WILL DEEPEN
FURTHER ON THURSDAY AS IT CROSSES JAMES BAY...RESULTING IN GOOD
CHANCE OF WESTERLY GALES 35-40 KTS OVER MUCH OF THE LAKE BY AFTN.
WINDS DIMINISH STEADILY THROUGH FRIDAY AS LOW MOVES FARTHER AWAY AND
NEW LOW PRESSURE NEARS FM THE NORTHERN PLAINS. WINDS SHOULD BECOME
SOUTH OR SOUTHEAST AHEAD OF THAT NEXT LOW. WINDS TO 30 KTS FRIDAY
NIGHT INTO SATURDAY OVER EASTERN LK SUPERIOR...THEN ALL AREAS BY
LATE SATURDAY AS WINDS BECOME WEST-NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-242>244-263-264.
GALE WARNING FROM 3 PM THIS AFTERNOON TO 5 AM EST WEDNESDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
955 AM CST TUE JAN 13 2015
.UPDATE...
ISSUED AT 955 AM CST TUE JAN 13 2015
WILL CANCEL/EXPIRE THE WIND CHILL ADVIOSRY FOR THE FAR EASTERN
COUNTIES. OTHERWISE THE MAIN ISSUE IS A BAND OF IFR TO MVFR
CEILINGS MOVING INTO WESTERN NORTH DAKOTA. HAVE SLOWED THE
PROGRESSION OF THE CLOUDS INTO NORTH DAKOTA AND CUT BACK ON CLOUD
AMOUNT AS NOTED BY LATERST HRRR.
UPDATE ISSUED AT 622 AM CST TUE JAN 13 2015
WILL TRIM THE WIND CHILL ADVISORY ACROSS THE CENTRAL SECTIONS
WHERE CHILLS HAVE RISEN WELL ABOVE CRITERIA. WILL LEAVE EASTERN N
SECTIONS GOING THROUGH 15Z. COMPLICATED STRATUS FIELD FORMING IN
RESPONSE TO LOW LEVEL WARM ADVECTION ACROSS SOUTH DAKOTA INTO
SOUTH CENTRAL NORTH DAKOTA. THEN COLD FRONTAL STRATUS WILL MOVE
INTO THE WEST LATER TODAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 204 AM CST TUE JAN 13 2015
MAIN CONCERNS IN THE SHORT TERM INCLUDE THE CURRENT WIND CHILL
ADVISORY HEADLINE...CLOUDS...AND POSSIBLE LIGHT PRECIPITATION
APPROACHING THE FAR NORTH LATE TUESDAY NIGHT.
FOR TUESDAY...THE CURRENT FOG/STRATUS IMAGERY LOOP SHOWS A CLEAR
SKY OVER WESTERN AND CENTRAL NORTH DAKOTA. HOWEVER...CLOUDS IN
WESTERN/CENTRAL SOUTH DAKOTA ARE RAPIDLY APPROACHING ADAMS AND SIOUX
COUNTIES. THIS IS PICKED UP BY THE HRRR AND IS FORECAST TO MOVE
INTO FAR SOUTH CENTRAL NORTH DAKOTA AND THEN ACROSS THE SOUTHERN
JAMES RIVER VALLEY THROUGH 18Z. WITH CLOUDS FORECAST TO SLIDE
ACROSS FAR SOUTH CENTRAL EARLY THIS MORNING...A PORTION OF THE
ONGOING WIND CHILL ADVISORY WILL NEED TO BE MONITORED CLOSELY FOR
A POSSIBLE EARLY CANCELLATION PRIOR TO 16Z. OTHERWISE THE REST OF
THE WIND CHILL ADVISORY AREA LOOKS IN GOOD SHAPE THROUGH 16Z.
ANOTHER AREA OF CLOUDS LOCATED IN EASTERN MONTANA IS ALSO GETTING
CLOSER TO THE WESTERN BORDER...NEAR BEACH. SO FAR CEILINGS WITH
BOTH THE SOUTH DAKOTA AND MONTANA CLOUDS ARE AROUND 5000FT...WITH
THE TRUE STRATUS DECK FILTERING IN ACROSS SOUTHWEST SASKATCHEWAN.
WITH THAT SAID...THE LATEST WATER VAPOR IMAGERY SHOWS OUR NEXT
PAIR OF SHORTWAVE TROUGHS THAT WILL AFFECT NORTH DAKOTA. THE FIRST
WAS SLIDING THROUGH SOUTH CENTRAL SASKATCHEWAN...AND THE SECOND
WAS OVER NORTHEAST MONTANA. UNDERNEATH WAS THE REFLECTION OF A
WEAK SURFACE COLD FRONT WITH A COLD POCKET OF AIR/-4C TO -6C
REFLECTED AT 850MB. THE STRATUS PER HRRR MODEL WILL ARRIVE IN
NORTHWEST NORTH DAKOTA BETWEEN 16Z-18Z AND THEN CONTINUE INTO
CENTRAL NORTH DAKOTA BY MID AFTERNOON/EARLY EVENING. HAVE UTILIZED
A BLEND OF THE HRRR/RAP13 FOR SKY GRIDS TODAY...AND THE NAM FOR
LATE THIS AFTERNOON THROUGH TONIGHT ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. WINDS WILL SHIFT TO THE WEST/NORTHWEST WITH THE
FRONTAL PASSAGE...FOLLOWED BY THE STRATUS DECK A FEW HOURS LATER.
FOR TUESDAY NIGHT...WARM AIR ADVECTION QUICKLY RE-ESTABLISHES
ITSELF...ESPECIALLY ACROSS THE NORTH AS A WARM FRONTAL SYSTEM
SLIDES THROUGH SASKATCHEWAN. THE STRONGEST VERTICAL MOTION/OMEGA
FIELD REMAINS IN CENTRAL/EASTERN SASKATCHEWAN AND INTO WESTERN
MANITOBA FROM 06Z- 12Z WEDNESDAY. THE NAM/GFS HOLD THE
PRECIPITATION THREAT NORTH OF THE BORDER THROUGH 12Z WEDS. THE
ECMWF AND GEM ARE SLIGHTLY FASTER AND FARTHER WEST. THE GEM
PRODUCES SOME LIGHT PRECIPITATION FROM CROSBY TO AROUND SHERWOOD
BY 12Z WEDNESDAY. WITH THE SREF SHOWING THE PRECIPITATION ALSO
NORTH OF THE BORDER...HAVE PAINTED IN 14 POPS ALONG THE BORDER
TOWARD 12Z WEDS...AS THE SHORT TERM PERIOD COMES TO AN END. NOT
EXPECTING ANY WIND CHILL HEADLINES TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 204 AM CST TUE JAN 13 2015
THE EXTENDED PERIOD CONTINUES TO DISPLAY A GOOD WARMING TREND AS
MID LEVEL FLOWS STRENGTHEN AND GRADUALLY BACK FROM A NORTHWEST TO
A WESTERLY FLOW. THIS WILL BRING MODIFIED PACIFIC AIR INTO THE
NORTHERN PLAINS BEGINNING WEDNESDAY. AS THE WARMER AIR MOVES IN
THERE IS A SLIGHT CHANCE OF PRECIPITATION ALONG A WARM FRONT
MOVING THROUGH THE REGION WEDNESDAY MORNING NORTH CENTRAL. CURRENT POPS
ARE LOW (20) WITH THE NAM DRY AND THE GFS JUST SPOTTY LIGHT
PRECIP. MODEL SOUNDINGS ARE FAIRLY DRY IN THE LOW LAYERS WHICH IS
PROBLEMATIC FOR DETERMINING PRECIP TYPE. COOLING THE THERMAL
PROFILES TO THE WET BULB RESULT IN ALL SNOW. BUT BOURGOUIN PROCESS
FROM THE BUFKIT ANALYSIS WANTS TO PAINT SOME LIGHT FREEZING RAIN.
ALL IN ALL ONLY 20 POPS SO DECENT CHANCE IT WILL BE DRY AFTER ALL.
FOR NOW LEFT IF SLIGHT CHANCE FOR SNOW. THURSDAY AND FRIDAY SHOW A
NICE WARM UP INTO THE 40S SOUTHWEST TO THE 30S CENTRAL AND NORTH.
THE REMAINDER OF THE EXTENDED WILL HAVE SOME SPOTTY PRECIPITATION
WITH LOW POPS THROUGH OUT AS THE MID LEVEL FLOW OR JET STREAM
ENERGY REMAINS MODERATE TO STRONG BUT MOISTURE IS WEAK. THE RESULT
WILL BE FAST MOVING SYSTEM WITH LITTLE MOISTURE,
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 955 AM CST TUE JAN 13 2015
MAIN IMPACT TO AVIATION WILL BE AN AREA OF STRATUS BEHIND A WEAK
COLD FRONT...WHICH WILL SLIDE FROM NORTHWEST TO SOUTHEAST DURING THE
DAY. EXPECT THE STRATUS TO FIRST IMPACT KISN FROM 17Z-22Z
TUESDAY. THE STRATUS MAY THEN MOVE INTO KMOT/KBIS/KDIK BEGINNING
AROUND 20Z. KJMS WILL SEE A PERIOD OF VFR CIGS FROM 14Z TO 18Z
WITH THE STRATUS/MVFR CIGS NOT ARRIVING UNTIL AFTER 00Z WEDNESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ004-005-
013-023-025-037-048-051.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...WAA
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
625 AM CST TUE JAN 13 2015
.UPDATE...
ISSUED AT 622 AM CST TUE JAN 13 2015
WILL TRIM THE WIND CHILL ADVISORY ACROSS THE CENTRAL SECTIONS
WHERE CHILLS HAVE RISEN WELL ABOVE CRITERIA. WILL LEAVE EASTERN N
SECTIONS GOING THROUGH 15Z. COMPLICATED STRATUS FIELD FORMING IN
RESPONSE TO LOW LEVEL WARM ADVECTION ACROSS SOUTH DAKOTA INTO
SOUTH CENTRAL NORTH DAKOTA. THEN COLD FRONTAL STRATUS WILL MOVE
INTO THE WEST LATER TODAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 204 AM CST TUE JAN 13 2015
MAIN CONCERNS IN THE SHORT TERM INCLUDE THE CURRENT WIND CHILL
ADVISORY HEADLINE...CLOUDS...AND POSSIBLE LIGHT PRECIPITATION
APPROACHING THE FAR NORTH LATE TUESDAY NIGHT.
FOR TUESDAY...THE CURRENT FOG/STRATUS IMAGERY LOOP SHOWS A CLEAR
SKY OVER WESTERN AND CENTRAL NORTH DAKOTA. HOWEVER...CLOUDS IN
WESTERN/CENTRAL SOUTH DAKOTA ARE RAPIDLY APPROACHING ADAMS AND SIOUX
COUNTIES. THIS IS PICKED UP BY THE HRRR AND IS FORECAST TO MOVE
INTO FAR SOUTH CENTRAL NORTH DAKOTA AND THEN ACROSS THE SOUTHERN
JAMES RIVER VALLEY THROUGH 18Z. WITH CLOUDS FORECAST TO SLIDE
ACROSS FAR SOUTH CENTRAL EARLY THIS MORNING...A PORTION OF THE
ONGOING WIND CHILL ADVISORY WILL NEED TO BE MONITORED CLOSELY FOR
A POSSIBLE EARLY CANCELLATION PRIOR TO 16Z. OTHERWISE THE REST OF
THE WIND CHILL ADVISORY AREA LOOKS IN GOOD SHAPE THROUGH 16Z.
ANOTHER AREA OF CLOUDS LOCATED IN EASTERN MONTANA IS ALSO GETTING
CLOSER TO THE WESTERN BORDER...NEAR BEACH. SO FAR CEILINGS WITH
BOTH THE SOUTH DAKOTA AND MONTANA CLOUDS ARE AROUND 5000FT...WITH
THE TRUE STRATUS DECK FILTERING IN ACROSS SOUTHWEST SASKATCHEWAN.
WITH THAT SAID...THE LATEST WATER VAPOR IMAGERY SHOWS OUR NEXT
PAIR OF SHORTWAVE TROUGHS THAT WILL AFFECT NORTH DAKOTA. THE FIRST
WAS SLIDING THROUGH SOUTH CENTRAL SASKATCHEWAN...AND THE SECOND
WAS OVER NORTHEAST MONTANA. UNDERNEATH WAS THE REFLECTION OF A
WEAK SURFACE COLD FRONT WITH A COLD POCKET OF AIR/-4C TO -6C
REFLECTED AT 850MB. THE STRATUS PER HRRR MODEL WILL ARRIVE IN
NORTHWEST NORTH DAKOTA BETWEEN 16Z-18Z AND THEN CONTINUE INTO
CENTRAL NORTH DAKOTA BY MID AFTERNOON/EARLY EVENING. HAVE UTILIZED
A BLEND OF THE HRRR/RAP13 FOR SKY GRIDS TODAY...AND THE NAM FOR
LATE THIS AFTERNOON THROUGH TONIGHT ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. WINDS WILL SHIFT TO THE WEST/NORTHWEST WITH THE
FRONTAL PASSAGE...FOLLOWED BY THE STRATUS DECK A FEW HOURS LATER.
FOR TUESDAY NIGHT...WARM AIR ADVECTION QUICKLY RE-ESTABLISHES
ITSELF...ESPECIALLY ACROSS THE NORTH AS A WARM FRONTAL SYSTEM
SLIDES THROUGH SASKATCHEWAN. THE STRONGEST VERTICAL MOTION/OMEGA
FIELD REMAINS IN CENTRAL/EASTERN SASKATCHEWAN AND INTO WESTERN
MANITOBA FROM 06Z- 12Z WEDNESDAY. THE NAM/GFS HOLD THE
PRECIPITATION THREAT NORTH OF THE BORDER THROUGH 12Z WEDS. THE
ECMWF AND GEM ARE SLIGHTLY FASTER AND FARTHER WEST. THE GEM
PRODUCES SOME LIGHT PRECIPITATION FROM CROSBY TO AROUND SHERWOOD
BY 12Z WEDNESDAY. WITH THE SREF SHOWING THE PRECIPITATION ALSO
NORTH OF THE BORDER...HAVE PAINTED IN 14 POPS ALONG THE BORDER
TOWARD 12Z WEDS...AS THE SHORT TERM PERIOD COMES TO AN END. NOT
EXPECTING ANY WIND CHILL HEADLINES TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 204 AM CST TUE JAN 13 2015
THE EXTENDED PERIOD CONTINUES TO DISPLAY A GOOD WARMING TREND AS
MID LEVEL FLOWS STRENGTHEN AND GRADUALLY BACK FROM A NORTHWEST TO
A WESTERLY FLOW. THIS WILL BRING MODIFIED PACIFIC AIR INTO THE
NORTHERN PLAINS BEGINNING WEDNESDAY. AS THE WARMER AIR MOVES IN
THERE IS A SLIGHT CHANCE OF PRECIPITATION ALONG A WARM FRONT
MOVING THROUGH THE REGION WEDNESDAY MORNING NORTH CENTRAL. CURRENT POPS
ARE LOW (20) WITH THE NAM DRY AND THE GFS JUST SPOTTY LIGHT
PRECIP. MODEL SOUNDINGS ARE FAIRLY DRY IN THE LOW LAYERS WHICH IS
PROBLEMATIC FOR DETERMINING PRECIP TYPE. COOLING THE THERMAL
PROFILES TO THE WET BULB RESULT IN ALL SNOW. BUT BOURGOUIN PROCESS
FROM THE BUFKIT ANALYSIS WANTS TO PAINT SOME LIGHT FREEZING RAIN.
ALL IN ALL ONLY 20 POPS SO DECENT CHANCE IT WILL BE DRY AFTER ALL.
FOR NOW LEFT IF SLIGHT CHANCE FOR SNOW. THURSDAY AND FRIDAY SHOW A
NICE WARM UP INTO THE 40S SOUTHWEST TO THE 30S CENTRAL AND NORTH.
THE REMAINDER OF THE EXTENDED WILL HAVE SOME SPOTTY PRECIPITATION
WITH LOW POPS THROUGH OUT AS THE MID LEVEL FLOW OR JET STREAM
ENERGY REMAINS MODERATE TO STRONG BUT MOISTURE IS WEAK. THE RESULT
WILL BE FAST MOVING SYSTEM WITH LITTLE MOISTURE,
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 622 AM CST TUE JAN 13 2015
MAIN IMPACT TO AVIATION WILL BE AN AREA OF STRATUS BEHIND A WEAK
COLD FRONT...WHICH WILL SLIDE FROM NORTHWEST TO SOUTHEAST DURING THE
DAY. EXPECT THE STRATUS TO FIRST IMPACT KISN FROM 16Z-22Z TUESDAY.
THE STRATUS WILL THEN MOVE INTO KMOT/KBIS/KDIK BEGINNING AROUND 20Z.
KJMS WILL SEE A PERIOD OF VFR CIGS FROM 14Z TO 18Z WITH THE
STRATUS/MVFR CIGS NOT ARRIVING UNTIL AFTER 00Z WEDNESDAY. MVFR CIGS
LOOK TO BE MAINTAINED AT ALL TERMINALS THROUGH 12Z WEDNESDAY EXCEPT
AT KISN AND KDIK.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ004-005-
013-023-025-037-048-051.
&&
$$
UPDATE...WAA
SHORT TERM...KS
LONG TERM...WAA
AVIATION...KS
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
933 AM CST TUE JAN 13 2015
.UPDATE...
ISSUED AT 933 AM CST TUE JAN 13 2015
HAVE LET THE WIND CHILL ADVISORY EXPIRE ON SCHEDULE EXCEPT FOR
THE NORTHEAST...MAINLY SOUTHWEST MN...WHICH IS SCHEDULED TO
EXPIRE AT 11 AM. TEMPERATURES RISING SLOWLY BUT STEADILY. A COUPLE
OF COLD WIND CHILL READINGS IN NORTHWEST IA DUE TO WINDS ABOUT 5
MPH WILL BE ALLEVIATING SHORTLY. NO MAJOR CHANGES
OTHERWISE...THOUGH HAVE GONE SLIGHTLY FASTER ON THE CLOUD INCREASE
EAST THIS AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CST TUE JAN 13 2015
CENTER OF THE ARCTIC DOME OF HIGH PRESSURE HAS SHIFTED EAST AND
RETURN FLOW ON THE BACKSIDE OF THE HIGH HAS BEGUN TO INCREASE ACROSS
A LARGE PORTION OF THE AREA. WITH COLD DENSE AIR LINGERING AND
WINDS INCREASING...HAVE EXTENDED WIND CHILL ADVISORY ACROSS THE
EAST THROUGH 17Z.
HAVE SOME VERY SPOTTY FOG ACROSS THE AREA THIS MORNING. THE HRRR IS
NOT DOING A GOOD JOB IN PICKING THIS UP...BUT THE RAP IS SOMEWHAT
BETTER BUT MAY BE AN OVERSTATEMENT ON FOG. HAVE ADDED PATCHY
WORDING FROM NEAR SIOUX FALLS DOWN INTO NORTHWEST IOWA...BUT PATCHY
MAY BE AN OVERSTATEMENT GIVEN THE FLAKY NATURE OF THIS FOG.
OTHERWISE...FOCUS TODAY IS ON WAVE MIGRATING DOWN FROM
SASKATCHEWAN INTO MINNESOTA LATE IN THE DAY. MODELS SHOW THE
DYNAMICS SCRAPING OUR AREA...AND HAVE RAISED POPS ACCORDINGLY.
AGREE WITH PREVIOUS FORECASTER THAT SNOW AMOUNTS WILL NOT AMOUNT
TO MUCH...AS WAVE IS RELATIVELY QUICK MOVING AND SNOW SHOULD NOT
LAST IN ANY GIVEN LOCATION MORE THAN A FEW HOURS. HIGH
TEMPERATURES WILL BE WARMER THAN YESTERDAY...BUT IT WILL STILL BE
A STRUGGLE TO SHAKE THE SINGLE DIGITS IN THE EAST.
BOUNDARY MOVES THROUGH THE AREA TONIGHT...WITH WARMER AIR FOLLOWING
BEHIND THE FRONT. CLOUDS GRADUALLY CLEAR BEHIND THE WAVE LEADING TO
A BIT OF RADIATIONAL COOLING...BUT DO NOT THINK TEMPERATURES WILL
FALL MUCH WITH WARMER AIR MOVING IN. THE GREATEST COOLING WILL OCCUR
IN THE WEST WHERE CLEAR CONDITIONS WILL PERSIST LONGER THROUGH THE
NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 324 AM CST TUE JAN 13 2015
A NORTHWEST FLOW ALOFT WILL CHARACTERIZE THE REST OF THE FORECAST
WITH OCCASIONAL SHORT WAVES DIVING SOUTHEAST GRAZING THIS AREA.
WEDNESDAY FINALLY USHERS IN SOME MILDER AIR...WITH 925MB
TEMPERATURES SUGGESTING 20 TO 25 FOR HIGHS ALONG AND EAST OF
INTERSTATE 29...PROGRESSIVELY WARMING TO AROUND 30 AT CHAMBERLAIN.
AS THEY WERE YESTERDAY...BOTH THE NAM AND GFS ARE SHOWING A HINT AT
SOME STRATUS WEST OF I 29 THROUGH MIDDAY WEDNESDAY...BEFORE
EVAPORATING THE CLOUDS SOMEWHAT THROUGH THE AFTERNOON HOURS AS THEY
TRY TO PROGRESS EAST. BUT AT ANY RATE CONDITIONS LOOK DRY.
THEN A MILD AIR MASS IS IN PLACE THURSDAY AND FRIDAY WITH 925MB
TEMPERATURES WELL ABOVE FREEZING. CURRENT THOUGHTS ARE THAT IT
APPEARS THAT MANY CONSENSUS GUIDANCE VALUES ARE A LITTLE COLD FOR
OUR SOUTHWEST ZONES...EXCEPT FOR MOS VALUES. THEREFORE BLENDED IN
MOS TO GIVE GREGORY COUNTY MID 40S FOR HIGHS ON THURSDAY AND
FRIDAY...WITH THE REST OF THE FORECAST AREA IN THE 30S GOING
ISOTHERMAL FROM 925MB.
FOR THE REMAINDER OF THE FORECAST SATURDAY THROUGH MONDAY...THERE IS
THE USUAL MODEL DISCREPANCY BETWEEN THE VARIOUS DETERMINISTIC
MODELS. BUT OVERALL IT STILL LOOKS DRY NO MATTER WHAT SOLUTION IS
OUT THERE WITH MILD WEATHER CONTINUING FOR MID JANUARY STANDARDS.
SATURDAY MAY BE RATHER WINDY BEHIND A SURFACE TROUGH PASSAGE WITH
DIRECTIONS FROM THE NORTHWEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 534 AM CST TUE JAN 13 2015
VFR CONDITIONS EXPECTED THROUGH 18Z. THEREAFTER...WEAK DISTURBANCE
WILL MOVE THROUGH POTENTIALLY PRODUCING A FEW FLURRIES ALONG
HIGHWAY 14 INCLUDING KHON...BUT DID NOT INCLUDE IN TAF. AS
BOUNDARY MOVES THROUGH...MVFR CEILINGS WILL DEVELOP AND PREVAIL
THROUGH THE REMAINDER OF THE PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR SDZ040.
MN...WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR MNZ071-072-
080-081-089-090-097.
IA...WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR IAZ003.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...MJ
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
537 AM CST TUE JAN 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CST TUE JAN 13 2015
CENTER OF THE ARCTIC DOME OF HIGH PRESSURE HAS SHIFTED EAST AND
RETURN FLOW ON THE BACKSIDE OF THE HIGH HAS BEGUN TO INCREASE ACROSS
A LARGE PORTION OF THE AREA. WITH COLD DENSE AIR LINGERING AND
WINDS INCREASING...HAVE EXTENDED WIND CHILL ADVISORY ACROSS THE
EAST THROUGH 17Z.
HAVE SOME VERY SPOTTY FOG ACROSS THE AREA THIS MORNING. THE HRRR IS
NOT DOING A GOOD JOB IN PICKING THIS UP...BUT THE RAP IS SOMEWHAT
BETTER BUT MAY BE AN OVERSTATEMENT ON FOG. HAVE ADDED PATCHY
WORDING FROM NEAR SIOUX FALLS DOWN INTO NORTHWEST IOWA...BUT PATCHY
MAY BE AN OVERSTATEMENT GIVEN THE FLAKY NATURE OF THIS FOG.
OTHERWISE...FOCUS TODAY IS ON WAVE MIGRATING DOWN FROM
SASKATCHEWAN INTO MINNESOTA LATE IN THE DAY. MODELS SHOW THE
DYNAMICS SCRAPING OUR AREA...AND HAVE RAISED POPS ACCORDINGLY.
AGREE WITH PREVIOUS FORECASTER THAT SNOW AMOUNTS WILL NOT AMOUNT
TO MUCH...AS WAVE IS RELATIVELY QUICK MOVING AND SNOW SHOULD NOT
LAST IN ANY GIVEN LOCATION MORE THAN A FEW HOURS. HIGH
TEMPERATURES WILL BE WARMER THAN YESTERDAY...BUT IT WILL STILL BE
A STRUGGLE TO SHAKE THE SINGLE DIGITS IN THE EAST.
BOUNDARY MOVES THROUGH THE AREA TONIGHT...WITH WARMER AIR FOLLOWING
BEHIND THE FRONT. CLOUDS GRADUALLY CLEAR BEHIND THE WAVE LEADING TO
A BIT OF RADIATIONAL COOLING...BUT DO NOT THINK TEMPERATURES WILL
FALL MUCH WITH WARMER AIR MOVING IN. THE GREATEST COOLING WILL OCCUR
IN THE WEST WHERE CLEAR CONDITIONS WILL PERSIST LONGER THROUGH THE
NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 324 AM CST TUE JAN 13 2015
A NORTHWEST FLOW ALOFT WILL CHARACTERIZE THE REST OF THE FORECAST
WITH OCCASIONAL SHORT WAVES DIVING SOUTHEAST GRAZING THIS AREA.
WEDNESDAY FINALLY USHERS IN SOME MILDER AIR...WITH 925MB
TEMPERATURES SUGGESTING 20 TO 25 FOR HIGHS ALONG AND EAST OF
INTERSTATE 29...PROGRESSIVELY WARMING TO AROUND 30 AT CHAMBERLAIN.
AS THEY WERE YESTERDAY...BOTH THE NAM AND GFS ARE SHOWING A HINT AT
SOME STRATUS WEST OF I 29 THROUGH MIDDAY WEDNESDAY...BEFORE
EVAPORATING THE CLOUDS SOMEWHAT THROUGH THE AFTERNOON HOURS AS THEY
TRY TO PROGRESS EAST. BUT AT ANY RATE CONDITIONS LOOK DRY.
THEN A MILD AIR MASS IS IN PLACE THURSDAY AND FRIDAY WITH 925MB
TEMPERATURES WELL ABOVE FREEZING. CURRENT THOUGHTS ARE THAT IT
APPEARS THAT MANY CONSENSUS GUIDANCE VALUES ARE A LITTLE COLD FOR
OUR SOUTHWEST ZONES...EXCEPT FOR MOS VALUES. THEREFORE BLENDED IN
MOS TO GIVE GREGORY COUNTY MID 40S FOR HIGHS ON THURSDAY AND
FRIDAY...WITH THE REST OF THE FORECAST AREA IN THE 30S GOING
ISOTHERMAL FROM 925MB.
FOR THE REMAINDER OF THE FORECAST SATURDAY THROUGH MONDAY...THERE IS
THE USUAL MODEL DISCREPANCY BETWEEN THE VARIOUS DETERMINISTIC
MODELS. BUT OVERALL IT STILL LOOKS DRY NO MATTER WHAT SOLUTION IS
OUT THERE WITH MILD WEATHER CONTINUING FOR MID JANUARY STANDARDS.
SATURDAY MAY BE RATHER WINDY BEHIND A SURFACE TROUGH PASSAGE WITH
DIRECTIONS FROM THE NORTHWEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 534 AM CST TUE JAN 13 2015
VFR CONDITIONS EXPECTED THROUGH 18Z. THEREAFTER...WEAK DISTURBANCE
WILL MOVE THROUGH POTENTIALLY PRODUCING A FEW FLURRIES ALONG
HIGHWAY 14 INCLUDING KHON...BUT DID NOT INCLUDE IN TAF. AS
BOUNDARY MOVES THROUGH...MVFR CEILINGS WILL DEVELOP AND PREVAIL
THROUGH THE REMAINDER OF THE PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR SDZ038-039-
053>056-059>062-065>071.
WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR SDZ040.
MN...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ098.
WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR MNZ071-072-
080-081-089-090-097.
IA...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ001-002.
WIND CHILL ADVISORY UNTIL 11 AM CST THIS MORNING FOR IAZ003.
NE...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ013-014.
&&
$$
SHORT TERM...
LONG TERM...MJ
AVIATION...
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
411 AM MST TUE JAN 13 2015
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 302 AM MST TUE JAN 13 2015
LATEST WATER VAPOR IMAGERY SHOWS SOME WEAK ENERGY PASSING THROUGH
SOUTHWESTERN SOUTH DAKOTA WITH PRIMARILY ZONAL FLOW ACROSS THE
FORECAST AREA. AT THE SURFACE...HIGH PRESSURE IS OVER THE CENTRAL
PLAINS WITH A LEE TROF ACROSS EASTERN WYOMING. RADAR AND SURFACE
OBSERVATIONS INDICATE SOME LIGHT SNOW/FLURRIES ACROSS SOUTHWESTERN
SOUTH DAKOTA AND AROUND NEWCASTLE.
FOR THIS MORNING...COULD SEE SOME PATCHY FOG ACROSS PORTIONS OF
NORTHEASTERN WYOMING AND WESTERN SOUTH DAKOTA AS NAM AND RAPID
REFRESH MODEL INDICATES A SHALLOW LAYER OF MOISTURE NEAR THE
SURFACE. DON/T EXPECT FOG TO BE WIDESPREAD DUE TO THE LOW/MID LEVEL
CLOUDS CURRENTLY SPREADING ACROSS THE AREA. ALSO THE BAND OF LIGHT
SNOW/FLURRIES WILL CONTINUE TO PUSH EASTWARD FROM SOUTHWESTERN SOUTH
DAKOTA INTO SOUTH CENTRAL SOUTH DAKOTA. THUS ADDED SOME SLIGHT POPS
FOR THIS AREA THIS MORNING. OTHERWISE CLOUDS WILL DECREASE THIS
AFTERNOON FROM WEST TO EAST WITH 850-700MB WARM AIR ADVECTION IN
WESTERLY FLOW.
FOR TONIGHT...WILL SEE CLOUDS DISSIPATING EVEN MORE...BECOMING
MOSTLY CLEAR ACROSS THE AREA. LATEST HRRR AND NAM DOES INDICATE THE
POSSIBILITY OF FOG IN SOUTH CENTRAL SOUTH DAKOTA AROUND WINNER LATE
TONIGHT. HOWEVER WITH DRY AIR PUSHING IN FROM THE WEST...WILL LEAVE
IT OUT FOR NOW AND LET THE DAY SHIFT RE-EXAMINE. TEMPERATURES SHOULD
FALL TO READINGS CLOSE TO GUIDANCE VALUES IN THE UPPER SINGLE DIGITS
TO TEENS.
FOR WEDNESDAY AND WEDNESDAY NIGHT...THE WARMING TREND WILL BEGIN AS
HIGH PRESSURE BUILDS ACROSS THE WESTERN CONUS AND ROCKIES. WITH
LIMITED SKY COVER AND WESTERLY WINDS...EXPECT TEMPERATURES TO BE
NEAR TO SLIGHTLY ABOVE SEASONAL AVERAGES.
.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 302 AM MST TUE JAN 13 2015
UPPER LEVEL RIDGING SETS UP OVER THE WESTERN AND CENTRAL CONUS
FOR MUCH OF THE EXTENDED PERIOD. THIS SHOULD BRING DRY CONDITIONS
AND NEAR TO ABOVE AVERAGE TEMPERATURES TO THE AREA. BREEZY
WESTERLY WINDS WILL HELP TEMPS WARM INTO THE 40S AND LOWER 50S
THURSDAY AND FRIDAY. A COOL FRONT EARLY SATURDAY WILL REDUCE HIGHS
A BIT FOR THE WEEKEND...BUT WILL STILL BE NEAR TO ABOVE AVERAGE. A
COUPLE OF DRY SHORTWAVES MOVE THROUGH THE RIDGE DURING THE
EXTENDED PERIOD...BUT MODELS ARE HINTING AT A MORE ACTIVE PATTERN
WITH SNOW POSSIBLE EARLY NEXT WEEK.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING
ISSUED AT 410 AM MST TUE JAN 13 2015
MVFR CIGS/VSBY POSSIBLE EARLY THIS MORNING WITH ANY
PATCHY FOG OR FLURRIES THAT MAY DEVELOP...BUT FOR THE MOST PART VFR
CONDITIONS ARE EXPECTED. MID CLOUDS WILL TRANSITION EASTWARD
TODAY...AND SKIES WILL GRADUALLY CLEAR.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...MLS
LONG TERM...POJORLIE
AVIATION...POJORLIE
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
946 AM CST TUE JAN 13 2015
.UPDATE...
WE HAVE UPDATED THE FORECAST TO LOWER HIGH TEMPERATURES A DEGREE
OR TWO ACROSS MOST AREAS TODAY. SATELLITE TRENDS ALONG WITH MODEL
DATA SUGGEST LOW CLOUDS AND NORTHERLY WINDS (COLD AIR ADVECTION)
WILL REMAIN INTACT TODAY. WE HAVE ALSO REMOVED PRECIPITATION
CHANCES FOR THE REMAINDER OF TODAY AS AN UPPER LEVEL SHORTWAVE
TROUGH MOVES EAST OF THE REGION. A STOUT UPPER JET IS NOTED ON THE
12Z DRT SOUNDING AND WATER VAPOR LOOP. HOWEVER...THE MID AND
UPPER LEVELS REMAIN FAIRLY DRY TODAY. HOURLY WINDS...DEW POINTS
AND TEMPERATURES HAVE ALSO BEEN UPDATED.
&&
.PREV DISCUSSION... /ISSUED 545 AM CST TUE JAN 13 2015/
AVIATION...
UPPER SHORT WAVE IS MOVING THROUGH THE STATE. BUT WITH COLD AIR
ADVECTION STILL OCCURRING AT THE SURFACE AND MORE ENERGY TO THE
WEST...CLEAR OUT WILL NOT HAPPEN. MOST AREAS ALONG AND EAST OF THE
ESCARPMENT ARE SOMEWHERE BETWEEN 1-2KFT...WITH PATCHY IFR. FARTHER
OUT INTO THE HILL COUNTRY THE IFR IS MORE WIDESPREAD WITH SOME
LOWER VISBYS. LOOK FOR THE DECKS TO HOLD FAIRLY STEADY IN MVFR
MOST IF NOT ALL THROUGHOUT TODAY. MODELS DIVERGE A BIT THIS
EVENING AS GFS AND EVEN THE HRRR ARE TRYING TO BRING IN SOME VFR
OVER THE SOUTH. DIDNT BUY INTO THIS JUST YET WITH THE COLD
TEMPERATURES AND CROSS SECTIONS THAT SHOW PLENTY OF OVERRUNNING.
AUS HAS BEEN FLUCTUATING BETWEEN IFR/MVFR THIS MORNING...WILL PUT
THEM IN MVFR THE NEXT FEW HOURS AND KEEP ALL THE TAF SITES IN MVFR
THE NEXT 24-30 HOURS. COULD GET SOME IFR EARLY WED MORNING BUT
KEPT HEIGHTS AROUND 1KFT. WINDS WILL BE PRIMARILY FROM THE NORTH
IN THE 5-10KT RANGE ALTHOUGH DRT WILL START TO SWITCH AROUND TO
THE EAST LATE TONIGHT.
PREV DISCUSSION... /ISSUED 329 AM CST TUE JAN 13 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...A MID AND UPPER LEVEL
SHORTWAVE EVIDENT ON SATELLITE ACROSS THE NORTHERN HILL COUNTRY
AND EDWARDS PLATEAU EARLY THIS MORNING. A FEW WEAK RETURNS ON
RADAR ACROSS NORTHERN VAL VERDE COUNTY AND SJT SOUTHERN CWA...WITH
A FEW AUTOMATED SITES REPORTING PRECIP. TEMPERATURES ARE CURRENTLY
32-34 DEGREES ACROSS THE NORTHERN HILL COUNTRY...AND FOR THE MOST
PART THIS WILL BE PATCHY LIGHT RAIN OR SPRINKLES THROUGH THE
MORNING HOURS ACROSS THE HILL COUNTRY. FARTHER SOUTHEAST AND
EAST...BAND OF MODERATE RAIN OCCURRING EAST OF I-35...POSSIBLY
ENHANCED BY NOSE OF LFQ OF 130KT JET STREAK. ALL ACTIVITY ACROSS
EASTERN CWA AND HILL COUNTRY SHOULD EXIT THE REGION BY NOON.
OTHERWISE COLD AND CLOUDY TODAY WITH HIGHS ONLY IN THE MID 40S.
ISENTROPIC UPGLIDE JUST ABOVE SURFACE WILL STRENGTHEN LATE
TONIGHT INTO MIDDAY WEDNESDAY. PATCHY/AREAS OF DRIZZLE AND LIGHT
RAIN WILL BE POSSIBLE TOWARDS DAYBREAK WEDNESDAY ALONG THE
ESCARPMENT...WITH A FEW SHOWERS POSSIBLE ACROSS THE COASTAL
PLAINS. COLD ON WEDNESDAY WITH HIGHS AGAIN ONLY IN THE MID 40S.
JR
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...A MID AND UPPER
LEVEL TROUGH AXIS WILL MOVE THROUGH THE AREA THURSDAY
MORNING...WITH NORTHWEST FLOW PROMOTING CLEARING OVER THE AREA.
HIGHS INTO THE 50S ON THURSDAY AND BACK TO SEASONAL NORMS IN THE
60S FRIDAY AND SATURDAY. GFS IS BULLISH COMPARED TO ECMWF WITH
PRECIP CHANCES EARLY NEXT WEEK FROM PACIFIC DISTURBANCE IN
SOUTHWEST FLOW ALOFT. FOR NOW WILL ONLY SHOW A SLIGHT CHANCE OF
SHOWERS MONDAY INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 43 36 44 36 55 / 10 10 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 42 36 44 34 54 / 10 10 20 10 -
NEW BRAUNFELS MUNI AIRPORT 43 38 45 36 55 / 10 10 20 10 -
BURNET MUNI AIRPORT 39 33 42 32 54 / 10 10 20 - -
DEL RIO INTL AIRPORT 45 40 49 38 57 / - - 10 - -
GEORGETOWN MUNI AIRPORT 39 34 43 33 53 / 10 10 20 - -
HONDO MUNI AIRPORT 46 38 47 36 58 / - 10 20 - -
SAN MARCOS MUNI AIRPORT 43 37 44 36 54 / 10 10 20 10 -
LA GRANGE - FAYETTE REGIONAL 45 38 45 37 54 / 20 10 20 10 -
SAN ANTONIO INTL AIRPORT 45 38 46 38 57 / 10 10 20 10 -
STINSON MUNI AIRPORT 45 40 46 38 57 / 10 10 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
545 AM CST TUE JAN 13 2015
.AVIATION...
UPPER SHORT WAVE IS MOVING THROUGH THE STATE. BUT WITH COLD AIR
ADVECTION STILL OCCURRING AT THE SURFACE AND MORE ENERGY TO THE
WEST...CLEAR OUT WILL NOT HAPPEN. MOST AREAS ALONG AND EAST OF THE
ESCARPMENT ARE SOMEWHERE BETWEEN 1-2KFT...WITH PATCHY IFR. FARTHER
OUT INTO THE HILL COUNTRY THE IFR IS MORE WIDESPREAD WITH SOME
LOWER VISBYS. LOOK FOR THE DECKS TO HOLD FAIRLY STEADY IN MVFR
MOST IF NOT ALL THROUGHOUT TODAY. MODELS DIVERGE A BIT THIS
EVENING AS GFS AND EVEN THE HRRR ARE TRYING TO BRING IN SOME VFR
OVER THE SOUTH. DIDNT BUY INTO THIS JUST YET WITH THE COLD
TEMPERATURES AND CROSS SECTIONS THAT SHOW PLENTY OF OVERRUNNING.
AUS HAS BEEN FLUCTUATING BETWEEN IFR/MVFR THIS MORNING...WILL PUT
THEM IN MVFR THE NEXT FEW HOURS AND KEEP ALL THE TAF SITES IN MVFR
THE NEXT 24-30 HOURS. COULD GET SOME IFR EARLY WED MORNING BUT
KEPT HEIGHTS AROUND 1KFT. WINDS WILL BE PRIMARILY FROM THE NORTH
IN THE 5-10KT RANGE ALTHOUGH DRT WILL START TO SWITCH AROUND TO
THE EAST LATE TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 329 AM CST TUE JAN 13 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...A MID AND UPPER LEVEL
SHORTWAVE EVIDENT ON SATELLITE ACROSS THE NORTHERN HILL COUNTRY
AND EDWARDS PLATEAU EARLY THIS MORNING. A FEW WEAK RETURNS ON
RADAR ACROSS NORTHERN VAL VERDE COUNTY AND SJT SOUTHERN CWA...WITH
A FEW AUTOMATED SITES REPORTING PRECIP. TEMPERATURES ARE CURRENTLY
32-34 DEGREES ACROSS THE NORTHERN HILL COUNTRY...AND FOR THE MOST
PART THIS WILL BE PATCHY LIGHT RAIN OR SPRINKLES THROUGH THE
MORNING HOURS ACROSS THE HILL COUNTRY. FARTHER SOUTHEAST AND
EAST...BAND OF MODERATE RAIN OCCURRING EAST OF I-35...POSSIBLY
ENHANCED BY NOSE OF LFQ OF 130KT JET STREAK. ALL ACTIVITY ACROSS
EASTERN CWA AND HILL COUNTRY SHOULD EXIT THE REGION BY NOON.
OTHERWISE COLD AND CLOUDY TODAY WITH HIGHS ONLY IN THE MID 40S.
ISENTROPIC UPGLIDE JUST ABOVE SURFACE WILL STRENGTHEN LATE
TONIGHT INTO MIDDAY WEDNESDAY. PATCHY/AREAS OF DRIZZLE AND LIGHT
RAIN WILL BE POSSIBLE TOWARDS DAYBREAK WEDNESDAY ALONG THE
ESCARPMENT...WITH A FEW SHOWERS POSSIBLE ACROSS THE COASTAL
PLAINS. COLD ON WEDNESDAY WITH HIGHS AGAIN ONLY IN THE MID 40S.
JR
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...A MID AND UPPER
LEVEL TROUGH AXIS WILL MOVE THROUGH THE AREA THURSDAY
MORNING...WITH NORTHWEST FLOW PROMOTING CLEARING OVER THE AREA.
HIGHS INTO THE 50S ON THURSDAY AND BACK TO SEASONAL NORMS IN THE
60S FRIDAY AND SATURDAY. GFS IS BULLISH COMPARED TO ECMWF WITH
PRECIP CHANCES EARLY NEXT WEEK FROM PACIFIC DISTURBANCE IN
SOUTHWEST FLOW ALOFT. FOR NOW WILL ONLY SHOW A SLIGHT CHANCE OF
SHOWERS MONDAY INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 45 36 44 36 55 / 10 10 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 45 36 44 34 54 / 10 10 20 10 -
NEW BRAUNFELS MUNI AIRPORT 46 38 45 36 55 / 10 10 20 10 -
BURNET MUNI AIRPORT 43 33 42 32 54 / 10 10 20 - -
DEL RIO INTL AIRPORT 47 40 49 38 57 / - - 10 - -
GEORGETOWN MUNI AIRPORT 42 34 43 33 53 / 10 10 20 - -
HONDO MUNI AIRPORT 47 38 47 36 58 / - 10 20 - -
SAN MARCOS MUNI AIRPORT 46 37 44 36 54 / 10 10 20 10 -
LA GRANGE - FAYETTE REGIONAL 47 38 45 37 54 / 20 10 20 10 -
SAN ANTONIO INTL AIRPORT 47 38 46 38 57 / 10 10 20 10 -
STINSON MUNI AIRPORT 47 40 46 38 57 / 10 10 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
ISSUED BY NATIONAL WEATHER SERVICE RALEIGH NC
940 AM EST TUE JAN 13 2015
.SYNOPSIS...
COLD HIGH PRESSURE BUILDING NORTH OF THE REGION THIS MORNING
WILL WEDGE SOUTH ALONG THE EASTERN SLOPES OF THE APPALACHIANS
THIS AFTERNOON THROUGH WEDNESDAY. A WEAK UPPER LEVEL
DISTURBANCE WILL PASS TO THE SOUTHEAST OF THE AREA LATE TONIGHT
BRINGING ANOTHER ROUND OF LIGHT WINTRY PRECIPITATION TO SOUTHERN
SECTIONS INTO WEDNESDAY. ANOTHER AREA OF HIGH PRESSURE BUILDS IN
FROM THE WEST LATER IN THE WEEK RESULTING IN DRIER AND WARMER
WEATHER FOR LATE WEEK INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 940 AM EST TUESDAY...
FORECAST IS IN GOOD SHAPE. LATEST SURFACE ANALYSIS SHOWS THE COLD
FRONT HAVING PUSHED SOUTHWESTWARD THROUGH MUCH OF THE CWA... HAVING
CLEARED ALL BUT THE SW SECTIONS. THE WEDGE REGIME DEVELOPMENT IS
WELL UNDERWAY WITH SURFACE WINDS EAST OF THE SLOPES OUT OF THE
NORTHEAST... AND WITH SATELLITE AND 12Z SOUNDINGS CONFIRMING
ABUNDANT LOW LEVEL MOIST AIR... WE`RE SEEING WEAK TERRAIN-UPGLIDE
RADAR RETURNS ON THE EAST SLOPES. THE INITIAL SURGE OF DRIER SURFACE
DEWPOINTS INTO THE AREA IS ALLOWING FOR A SURFACE DEWPOINT
DEPRESSION OF A FEW DEGREES... ENOUGH TO MINIMIZE ANY PRECIP
AMOUNTS. THE LATEST HRRR RUNS SUPPORT VERY LIGHT PATCHY PRECIP
PERSISTING THROUGH THIS AFTERNOON... WITH SLIGHTLY BETTER COVERAGE
IN THE SW AND LESS IN THE NE WHERE THE INFLUX OF DRIER AIR IN THE
LOW LEVELS WILL LIMIT AMOUNTS. BASED UPON THE SURFACE WET BULB
OBSERVATIONS... EXPECT THIS TO BE MOSTLY DRIZZLE EAST OF THE
MOUNTAINS (DUE TO THE DRYING ALOFT) FOR THE NEXT SEVERAL HOURS...
WITH LIGHT FREEZING DRIZZLE OR PERHAPS A LITTLE LIGHT SLEET IN THE
HIGHER ELEVATIONS. CURRENT FORECAST HAS THIS COVERED WELL WITH LOW
POPS SUGGESTING LOW COVERAGE. STILL EXPECT ONLY MINOR IMPACTS
THROUGH THIS AFTERNOON WITH THE PATCHY NATURE OF THE PRECIP... AND
WILL MAINTAIN THIS MENTION IN THE HWO. TEMPS SHOULD HOLD STEADY FOR
ANOTHER FEW HOURS BEFORE BEGINNING TO SLIP BACK THROUGH THE LOW 30S
LATE IN THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
AS OF 330 AM EST TUESDAY...
WILL START TONIGHT OFF WITH HIGH PRESSURE FIRMLY WEDGED AGAINST THE
EASTERN FACE OF THE APPALACHIANS...STRETCHING SOUTHWARD FROM NEW
ENGLAND ACROSS THE MID ATLANTIC. NORTHEASTERLY WIND FLOW WILL
CONTINUE TO DRAW VERY CHILLY AIR ACROSS OUR AREA...PUSHING OVERNIGHT
TEMPERATURES INTO THE 20S MOST LOCATIONS...WITH A FEW UPPER TEENS
POSSIBLE ALONG THE BLUE RIDGE.
ANOTHER AREA OF LOW PRESSURE WILL DEVELOP ALONG THE COAST LATE THIS
EVENING AS A SUPPORTING UPPER LEVEL TROUGH APPROACHES FROM THE WEST.
MOISTURE RADIATING INLAND FROM THE LOW WILL INTERACT WITH WITH THE
COLD AIR WEDGE TO BRING ANOTHER ROUND OF WINTRY PRECIPITATION TO
GENERALLY THE SOUTHERN THIRD OF OUR FORECAST AREA...THE FOOTHILLS
AND PIEDMONT OF NORTH CAROLINA INTO SOUTHSIDE VIRGINIA. THE DEPTH OF
THE COLD AIR WEDGE WITH TEMPERATURES WELL BELOW FREEZING IS SEVERAL
THOUSAND FEET THICK...SUPPORTING SLEET AND POSSIBLY SNOW FOR OUR
AREA...ALTHOUGH WOULD NOT BE SURPRISED TO SEE A FEW REPORTS OF
FREEZING RAIN ACROSS THE SOUTHERN PORTIONS OF CASWELL AND POSSIBLY
ROCKINGHAM COUNTIES OVERNIGHT WHERE THE LAYER OF SUB FREEZING
TEMPERATURES ABOVE THE SURFACE IS NOT AS THICK. BEST SUPPORT WILL
PASS SOUTH AND EAST OF OUR AREA OVERNIGHT...MEANING THAT WE WILL
RECEIVE A GLANCING BLOW FROM THIS SYSTEM FOR THE MOST PART. SLEET
ACCUMULATIONS WILL BE LESS THAN A QUARTER INCH...WITH PERHAPS A
GLAZING OF ICE. CONSIDERING THIS WILL BE THE FIRST WINTRY
PRECIPITATION FOR SPOTS IN THIS PART OF THE FORECAST AREA...WILL
ISSUE A WINTER WEATHER ADVISORY FROM 7 PM TONIGHT THROUGH NOON ON
WEDNESDAY DUE TO THE POTENTIAL IMPACTS TO TRAVEL.
WITH THE SYSTEM EXITING THE AREA ON WEDNESDAY AFTERNOON...EXPECT A
DRYING TREND TO TAKE PLACE AS HIGH PRESSURE OVER THE OHIO RIVER
VALLEY WILL BECOME THE DOMINANT FEATURE IN OUR WEATHER PATTERN.
CLOUD COVER AND LOW LEVEL MOISTURE WILL BE A LITTLE SLOW TO ERODE ON
WEDNESDAY NIGHT...SO WOULD NOT BE SURPRISED TO SEE A FEW FLURRIES OR
PATCHES OF LIGHT FREEZING DRIZZLE ACROSS THE MOUNTAINS. HOWEVER...
WITH WINDS GRADUALLY BECOMING WESTERLY BY SUNRISE THURSDAY...WILL
SEE A CLEARING TREND TAKE PLACE...WHICH WILL ALLOW AFTERNOON
TEMPERATURES TO RANGE FROM THE UPPER 30S WEST TO THE MID 40S EAST. A
WEAK COLD FRONT IS EXPECTED TO PASS ACROSS THE AREA LATE THURSDAY
NIGHT...WITH THE SUPPORTING UPPER LEVEL TROUGH BRINGING GUSTY
NORTHWEST WINDS TO THE MOUNTAINS TOWARD SUNRISE FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 145 PM EST MONDAY...
THIS PORTION OF THE FORECAST PACKAGE WILL BE CHARACTERIZED BY ABOVE
NORMAL TEMPERATURES AND LIMITED CHANCES OF PRECIPITATION.
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION FRIDAY AND
SATURDAY...ALL WHILE AN UPPER LEVEL RIDGE STRENGTHENS OVER THE HIGH
PLAINS THEN RETROGRADES WEST. IN TIME...THIS WILL ALLOW FOR A
GREATER POTENTIAL FOR NORTHWEST FLOW...AND CLIPPER SYSTEMS TO MOVE
THROUGH THE GREAT LAKES REGION AND INTO THE MID-ATLANTIC STATES.
OUR FORECAST WILL REFLECT DRY CONDITIONS FRIDAY AND SATURDAY FOR THE
ENTIRE FORECAST AREA AND LIMITED CLOUD COVER. SATURDAY WILL BE
WARMER THAN FRIDAY BY AN AVERAGE OF THREE TO SIX DEGREES WITH LOWER
50S COMMON ACROSS THE PIEDMONT AND MID 40S TO AROUND 50 DEGREES IN
THE MOUNTAINS.
FOR SUNDAY AND MONDAY...GUIDANCE VARIES ON THE TIMING AND
IMPACT...BUT ONE OF THE AFOREMENTIONED CLIPPER SYSTEMS MAY IMPACT
THE REGION. LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT...THERE WILL BE
A SLIGHT CHANCE OF RAIN/SNOW SHOWERS ACROSS WESTERN GREENBRIER
COUNTY. BY MONDAY AFTERNOON...THAT SLIGHT CHANCE EXPANDS TO MOST OF
SOUTHEAST WEST VIRGINIA AND POTENTIALLY SOME OF THE NEIGHBORING
COUNTIES OF SOUTHWEST VIRGINIA. HIGHS ON SUNDAY WILL BE SLIGHTLY
MILDER THAN THOSE OF SATURDAY. HOWEVER...ON MONDAY WITH GREATER
PROBABILITY FOR CLOUD COVER...AND A POTENTIAL SURFACE COLD FRONTAL
PASSAGE...TEMPERATURES WILL BE SLIGHTLY COOLER...COMPARABLE TO THOSE
OF SATURDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 545 AM EST TUESDAY...
SURFACE COLD FRONT IS NOW SOUTH OF THE AREA WITH THE LOW LEVEL
FLOW TURNING MORE TO A GUSTY NORTH TO NE TRAJECTORY AND IN TURN
AIDING LOWER STRATUS/STRATO-CU AT MOST LOCATIONS. THIS SETUP WILL
GRADUALLY LEAD TO A STRONGER WEDGE SCENARIO LATER THIS AFTERNOON
AS HIGH PRESSURE BUILDS SOUTH WITH THE FLOW BECOMING PREDOMINATE
NE TO EAST. THIS SHOULD KEEP WIDESPREAD MVFR TO IFR CIGS IN MOST
LOCATIONS...POSSIBLY EXCLUDING KLYH FOR A FEW HOURS THIS AFTERNOON
WHEN DRIER AIR MAY NOSE IN ENOUGH FROM THE NE TO CAUSE CIGS TO
LIFT A BIT. OTRW PRECIP REMAINS IFFY TODAY GIVEN MOSTLY LOW LEVEL
MOISTURE AND LACK OF FOCUS OTHER THAN FOR WEAK UPSLOPE LATE IN THE
DAY OVER THE SW. LATEST NAM CONTINUES TO SHOW PLENTY OF SPORADIC
COVERAGE OF ABOUT ALL PTYPES TODAY BUT APPEARS OVERDONE GIVEN
CURRENT DRYING TRENDS. THUS LEAVING OUT ANY VSBY REDUCTIONS UNTIL
VERY LATE IN THE DAY OVER THE WEST WHERE COULD SEE PATCHY -DZ OR
-FZDZ BREAK OUT TOWARD SUNSET AT KBLF/KROA/KBCB.
AN UPPER LEVEL DISTURBANCE WILL PASS ACROSS TONIGHT AND EARLY
WEDNESDAY. THIS FEATURE MAY RESULT IN A PERIOD OF LIGHT WINTRY MIX
AS WELL AS SOME ADDITIONAL FREEZING DRIZZLE AND RIME ICING. THIS
MOST LIKELY AROUND KDAN WHERE MOISTURE WILL BE DEEPER AND CLOSER
TO THE MAIN SWATH OF PRECIP PASSING TO THE SE. ELSW SOME POTENTIAL
FOR AREAS OF -FZDZ/PL WITH MORE FREEZING TYPE PRECIP AT KBLF PER
SHALLOW MOISTURE...AND SLEET/SNOW ELSW BUT LIGHT ENOUGH TO
PRECLUDE MUCH BELOW HIGH END MVFR AT WORSE OUTSIDE OF FOG.
ANY PRECIP SHOULD TAPER FROM WEST TO EAST WEDNESDAY MORNING WITH
LINGERING LOW CLOUDS SLOWLY ERODING IN THE AFTERNOON AS DRIER AIR
WORKS EAST. THIS MAY ALLOW SOME SITES ALONG/EAST OF THE BLUE RIDGE
TO RECOVER TO LATE DAY VFR CIGS OTRW MAINLY MVFR THROUGH THE DAY.
EXTENDED AVIATION DISCUSSION...
AFTER THE PASSAGE OF THIS FEATURE WEDNESDAY...A PUSH OF MUCH
DRIER AIR WILL INFILTRATE THE MID ATLANTIC REGION WITH VFR
LIKELY FROM WEDNESDAY NIGHT INTO SATURDAY UNDER HIGH PRESSURE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO NOON EST
WEDNESDAY FOR VAZ032-043-044-058-059.
NC...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO NOON EST
WEDNESDAY FOR NCZ003>006-019-020.
WV...NONE.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH/GIH
SHORT TERM...NF
LONG TERM...DS/NF
AVIATION...JH/PM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
500 AM CST TUE JAN 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST TUE JAN 13 2015
AT 3 AM...A 1045 MB SURFACE HIGH WAS CENTERED OVER LA CROSSE.
TEMPERATURES EARLY THIS MORNING WERE QUITE VARIABLE. AS USUAL NORTH
CENTRAL AND CENTRAL WISCONSIN WAS THE COLDEST WITH TEMPERATURES
RANGING FROM -15 TO -25. MEANWHILE ELSEWHERE...TEMPERATURES RANGED
FROM -5 TO -15. THE WARMEST LOCATIONS TENDED TO BE ON THE RIDGE
TOPS AND THE RIVER VALLEYS WERE THE COLDEST. FOR EXAMPLE...HERE AT
THE OFFICE WE ARE -3 AND IT IS -8 AT THE AIRPORT AND -12 AT
HOLMEN. IN SOME LOCATIONS...THIS MORNING IS THE COLDEST OF THE
WINTER. FOR EXAMPLE...AUSTIN IS -15 SURPASSING -13 ON JANUARY
5TH...MEDFORD IS -19 EQUALLY -19 ON JANUARY 5TH...AND FORT MCCOY
IS -20 SURPASSING -19 ON JANUARY 6TH.
FOR TODAY...WE WILL HAVE TO WATCH THE MVFR CLOUDS ACROSS EASTERN
AND SOUTHERN WISCONSIN AND NORTHERN ILLINOIS. BOTH THE GFS AND
RAP...INDICATE THAT THESE CLOUDS WILL DISSIPATE AS THE WINDS
FLOWING OFF LAKE MICHIGAN BECOME UNFAVORABLE TO KEEP THEM
DEVELOPING AND THEY RUN INTO VERY DRY AIR OVER THE REGION.
MEANWHILE THE NAM MOVES THEM SOUTH AND AS THE WINDS TURN SOUTHERLY
IN THE WAKE OF THE HIGH...THEY MOVE NORTHWARD INTO THE AREA LATE
THIS MORNING AND AFTERNOON. AT THIS TIME...THE GFS AND RAP MAKE A
BIT MORE SENSE.
FOR TONIGHT...THE 13.00Z MODELS NORTH AMERICAN MODELS CONTINUE TO
SHOW THAT THERE WILL BE SUFFICIENT 280 TO 305K ISENTROPIC LIFT AND
900 TO 500 MB FRONTOGENESIS AHEAD OF THE SHORT WAVE...CURRENTLY
OVER SOUTHERN MANITOBA...TO QUICKLY MOISTEN UP THE AIR MASS. THE
ECMWF HAS ALSO COME AROUND TO THIS SOLUTION. THE DEEPEST MOISTURE
AND LIFT WILL BE NORTH OF INTERSTATE 90 WITH UP TO 0.03 INCHES OF
QPF BEING PRODUCED. WITH SNOW TO LIQUID RATIOS OF 13-15 TO
1...EXPECT SNOW TOTAL UP TO A HALF INCH NORTH OF INTERSTATE 90.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 340 AM CST TUE JAN 13 2015
ON WEDNESDAY...SOME LIGHT SNOW MAY LINGER ACROSS PARTS OF WESTERN
WISCONSIN THROUGH 9 AM...BUT THERE WILL BE LITTLE...IF
ANY...ADDITIONAL SNOW ACCUMULATIONS. BEHIND THIS SYSTEM...
PACIFIC AIR WILL MOVE INTO THE REGION. THIS WILL RESULT IN SLIGHT
WARMER TEMPERATURES DESPITE LESS SUNSHINE THAN TODAY.
ON WEDNESDAY NIGHT AND THURSDAY MORNING...ANOTHER SHORT WAVE
TROUGH WILL MOVE QUICKLY SOUTHEAST THROUGH THE AREA. THE BEST AND
LIFT ASSOCIATED WITH THIS WAVE STILL APPEARS TO BE MAINLY NORTH OF
THE FORECAST AREA. THE GFS IS THE ONLY MODEL THAT SHOWS ENOUGH
SATURATION TO PRODUCE SOME LIGHT SNOW NORTH OF INTERSTATE 90.
MEANWHILE THE OTHER MODELS ARE DRY.
FROM THURSDAY NIGHT INTO FRIDAY...AN ELEVATED MIXED LAYER /EML/ WILL
MOVE INTO THE AREA FROM THE HIGH PLAINS. 900 TO 850 MB
TEMPERATURES CLIMB IN THE 5 TO 7C RANGE. THESE TEMPERATURES ALOFT
WILL LIKELY CAP SOME OF THE COLDER AIR NEAR THE SURFACE. HOWEVER
THE EML WILL ALSO PRODUCE QUITE A BIT OF SUNSHINE ACROSS THE AREA
WHICH WILL HELP HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID
30S. THIS WILL BE THE WARMEST TEMPERATURES SINCE JANUARY 4TH.
FROM SUNDAY INTO MONDAY...THE MODELS CONTINUE TO SHOW THAT A
CANADIAN FRONT WILL MOVE SOUTH INTO THE AREA. THE COLDEST AIR
MASS WILL BE NORTH AND EAST OF THE FORECAST AREA. THE GFS CONTINUE
TO BE ABOUT 5 TO 10 DEGREES COLDER THAN THE ECMWF. DUE TO THESE
DIFFERENCE JUST STAYED WITH THE MODEL CONSENSUS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 500 AM CST TUE JAN 13 2015
HIGH PRESSURE WILL KEEP SKIES CLEAR FOR THE DAYTIME HOURS. HIGH/MID
LEVEL CLOUDS WILL MOVE IN FROM THE WEST TONIGHT...AHEAD OF AN UPPER
LEVEL SHORTWAVE TROUGH. EXPECTING SOME -SN WITH THE
FEATURE...ALTHOUGH NOT ANTICIPATING VSBY RESTRICTIONS FOR KRST/KLSE
AT THIS TIME. THERE WILL BE A FURTHER LOWERING OF THE CLOUD DECK
WITH THE -SN...BUT UNSURE WHETHER MVFR CIGS WILL BE REALIZED. ITS
POSSIBLE. WILL KEEP VFR FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RIECK
AREA FORECAST DISCUSSION...CORRECTED
NWS CHEYENNE WY
446 AM MST TUE JAN 13 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 305 AM MST TUE JAN 13 2015
LATEST WATER VAPOR IMAGERY LOOP SHOWED A PRONOUNCED SPLIT FLOW
WITH A RIDGE JUST OFFSHORE THE PACIFIC COAST...A SOUTHERN STREAM
TROUGH MOVING SOUTHEAST ACROSS THE GREAT BASIN...AND A COUPLE OF
NORTHERN STREAM SHORTWAVE TROUGHS OVER THE DAKOTAS AND NEW ENGLAND.
REGIONAL SURFACE ANALYSIS DEPICTED THE WESTERN EDGE OF THE ARCTIC
AIR MASS ALONG THE CONTINENTAL DIVIDE. LIFT FROM WEAK ISENTROPIC
LEVEL FLOW OVER SHALLOW COLD DOME PRODUCED WIDESPREAD LOW CLOUDS...
FOG AND PATCHY LIGHT FREEZING DRIZZLE AND SNOW. TEMPERATURES RANGED
FROM THE MIDDLE TEENS TO UPPER 20S. WINDS WERE LIGHT AND VARIABLE.
THE 00Z/06Z NUMERICAL MODELS FAVOR A CONSENSUS APPROACH WITH THE
CONTINUATION OF THE SPLIT UPPER LEVEL PATTERN DURING THE SHORT
TERM. SOUTHERN STREAM TROUGH MAINTAINS ITS INTENSITY AS IT TRACKS
SOUTHEAST THROUGH THE FOUR CORNERS REGION AND NORTHERN MEXICO/FAR
WEST TX DURING THE NEXT 48 HOURS. MEANWHILE...THE SHARP RIDGE
NEAR THE WEST COAST WILL WEAKEN AND BROADEN AS SHORTWAVE ENERGY
FROM THE EASTERN PACIFIC APPROACHES BRITISH COLUMBIA. CONSEQUENTLY...
WINDS ALOFT WILL BACK FROM NORTHWEST TO WESTERLY. THE QUASI-STATIONARY
BOUNDARY TO THE WEST WILL SLOWLY PROGRESS EAST AS A WARM FRONT WITH
INCREASING WESTERLY LOW LEVEL FLOW.
REGARDS TO SENSIBLE WEATHER...LOW CLOUDS...FOG AND PATCHY LIGHT
WINTRY PRECIPITATION TO CONTINUE MOST AREAS THIS MORNING. CONDITIONS
WILL BEGIN TO IMPROVE THIS AFTERNOON AS ISENTROPIC LIFT WEAKENS AND
YIELDS TO DOWNGLIDE. LIGHT SNOW WILL LIKELY PERSIST OVER HIGHER
ELEVATIONS OF SOUTHERN CARBON AND ALBANY COUNTIES THIS AFTERNOON
BEFORE ENDING BY EVENING. HIGH TEMPERATURES TODAY WILL REMAIN BELOW
SEASONAL NORMALS WITH 20S TO LOWER 30S. UNDER CLEARING SKIES AND
LIGHT WINDS...LOW TEMPERATURES TONIGHT WILL PLUMMET INTO THE SINGLE
DIGITS AND LOWER TEENS.
WEDNESDAY WILL BE THE TRANSITION DAY AS THE WESTERLY LOW LEVEL
WINDS INCREASE...SHOVING THE SURFACE BOUNDARY EAST INTO THE PLAINS
DURING THE AFTERNOON. DOWNSLOPE FLOW EAST OF THE LARAMIE RANGE WILL
PUSH TEMPERATURES INTO THE 30S...WITH 20S TO THE WEST. LOW
TEMPERATURES WEDNESDAY NIGHT WILL BE 5 TO 10 DEGREES MILDER ACROSS
THE PLAINS. HIGH TEMPERATURES THURSDAY WILL AVERAGE 10 DEGREES
WARMER THAN WEDNESDAY WITH 40S PREVALENT EAST OF THE LARAMIE
RANGE. WESTERLY WINDS WILL BE INCREASING THROUGHOUT THE DAY WITH
GUSTS TO 35 KT ACROSS PORTIONS OF THE LARAMIE RANGE AND NORTHERN
CARBON COUNTY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 201 AM MST TUE JAN 13 2015
IT WILL BE A MILD AND WINDY START TO THE EXTENDED AS DOWNSLOPE FLOW
INCREASES BEHIND A SHORTWAVE MOVING ACROSS EASTERN WY. H7 TEMPS ARE
PROGGED BETWEEN +2 AND +4 DEG C ALONG AND EAST OF THE SOUTH LARAMIE
RANGE FRI AFTN PER THE GFS AND ECMWF. THE MOISTURE-STARVED NATURE
OF THE AFOREMENTIONED WAVE WILL LIMIT ANY PRECIP CHANCES AND KEEP
SKIES PARTLY TO MOSTLY SUNNY. WITH GOOD COMPRESSIONAL WARMING VIA
FAVORABLE WESTERLY DOWNSLOPE WINDS...EXPECT SEASONABLE WARMTH TO
CONTINUE FRI. MEX/ECM MOS TEMPS ARE WELL INTO THE 50S OVER THE
PLAINS...WHICH IS REALISTIC FOR AREAS THAT DO NOT HAVE MUCH SNOW
LEFT. WINDS ARE ALSO AN ISSUE FOR FRI AND SAT. THE GFS H85 CAG-CPR
GRADIENT INCREASES TO AROUND 60 METERS LATE THU NIGHT AND REMAINS
HIGH THROUGH SAT...ALONG WITH H75 FLOW IN EXCESS OF 50 KT OVER THE
PRIMARY WIND CORRIDORS OF SOUTHEAST WY. STRONG SUBSIDENCE WOULD
SUGGEST STRONG GAP WINDS. BORA EVENT COULD OCCUR OVER THE PLAINS
ON SAT MORNING WITH WEAK LOW-LEVEL COLD ADVECTION. STILL EXPECT
THAT HIGH WIND HEADLINES WILL BE NEEDED IN THE COMING DAYS. TRICKY
TEMPERATURE FORECAST FOR SAT WITH A FEW KEY DIFFERENCES IN THE
MODELS. THE ECMWF DELAYS THE FRONTAL PASSAGE UNTIL SAT AFTN AND
KEEPS THE DEEPER COLD TO THE NORTH. THE GFS ON THE OTHER HAND
OFFERS A MORE SUBSTANTIAL COLD PUSH BY 12Z SAT WITH THERMAL
PROFILES REBOUNDING BY AFTN. DECIDED TO KEEP THINGS A LITTLE BELOW
CONSENSUS MOS SINCE THIS GUIDANCE MAY NOT BE HANDLING THE COLD
ADVECTION VERY WELL. A LACK OF MOISTURE THROUGH THE TROPOSPHERE
WILL LIMIT PRECIP CHANCES THROUGH SUN. MODELS QUITE A BIT
DIFFERENT THAN YESTERDAY CONCERNING A PACIFIC NORTHWEST SHORTWAVE
NEXT WEEK. LATEST RUNS SUGGEST THIS SYSTEM WILL BE A MORE
PROGRESSIVE OPEN WAVE...AND NOT REALLY AFFECTING US UNTIL MON.
DOES NOT LOOK LIKE A MAJOR STORM AT THIS TIME...BUT EXPECT
INCREASING PRECIP CHANCES AS WE HEAD INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 437 AM MST TUE JAN 13 2015
WEST TO NORTHWEST WINDS SHOULD ALLOW MVFR TO IFR CONDITIONS TO
GRADUALLY IMPROVE FOR MOST TERMINALS THIS MORNING. KRWL AND KLAR
ARE THE EXCEPTIONS AS FZFG AND LOW CIGS WILL NOT BE EASY TO SCOUR
OUT FOR AREAS WEST OF THE LARAMIE RANGE. THE HRRR MODEL SUGGESTS
IFR/LIFR CONDITIONS DEVELOPING AT KLAR AFTER 14Z AND CONTINUING
THROUGH THE AFTERNOON. VFR CONDITIONS SHOULD RETURN AFTER 21Z FOR
ALL SITES ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE.
&&
.FIRE WEATHER...
ISSUED AT 200 AM MST TUE JAN 13 2015
THE ARCTIC AIR MASS THAT HAS GRIPED MUCH OF THE DISTRICT THE PAST FEW
DAYS WILL GRADUALLY RETREAT EAST. PERSISTENT LOW CLOUDS...FOG AND LIGHT
FREEZING DRIZZLE AND SNOW WILL PREVAIL THIS MORNING...WITH SLOWLY
IMPROVING CONDITIONS THIS AFTERNOON. COOL TEMPERATURES AND HIGH
HUMIDITY WILL PRECLUDE FIRE WEATHER CONCERNS TODAY. WESTERLY LOW
LEVEL WINDS WILL BRING WARMER TEMPERATURES AND DRIER CONDITIONS FOR
WEDNESDAY THROUGH FRIDAY. MINIMUM HUMIDITY VALUES WILL DROP TO 25 TO
35 PERCENT BY THE END OF THE WEEK. WINDS WILL INCREASE LATE IN THE
WEEK...WITH THE POSSIBILITY OF HIGH WINDS FOR WIND PRONE AREAS OF
SOUTHEAST WYOMING ON FRIDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
308 AM MST TUE JAN 13 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 305 AM MST TUE JAN 13 2015
LATEST WATER VAPOR IMAGERY LOOP SHOWED A PRONOUNCED SPLIT FLOW
WITH A RIDGE JUST OFFSHORE THE PACIFIC COAST...A SOUTHERN STREAM
TROUGH MOVING SOUTHEAST ACROSS THE GREAT BASIN...AND A COUPLE OF
NORTHERN STREAM SHORTWAVE TROUGHS OVER THE DAKOTAS AND NEW ENGLAND.
REGIONAL SURFACE ANALYSIS DEPICTED THE WESTERN EDGE OF THE ARCTIC
AIR MASS ALONG THE CONTINENTAL DIVIDE. LIFT FROM WEAK ISENTROPIC
LEVEL FLOW OVER SHALLOW COLD DOME PRODUCED WIDESPREAD LOW CLOUDS...
FOG AND PATCHY LIGHT FREEZING DRIZZLE AND SNOW. TEMPERATURES RANGED
FROM THE MIDDLE TEENS TO UPPER 20S. WINDS WERE LIGHT AND VARIABLE.
THE 00Z/06Z NUMERICAL MODELS FAVOR A CONSENSUS APPROACH WITH THE
CONTINUATION OF THE SPLIT UPPER LEVEL PATTERN DURING THE SHORT
TERM. SOUTHERN STREAM TROUGH MAINTAINS ITS INTENSITY AS IT TRACKS
SOUTHEAST THROUGH THE FOUR CORNERS REGION AND NORTHERN MEXICO/FAR
WEST TX DURING THE NEXT 48 HOURS. MEANWHILE...THE SHARP RIDGE
NEAR THE WEST COAST WILL WEAKEN AND BROADEN AS SHORTWAVE ENERGY
FROM THE EASTERN PACIFIC APPROACHES BRITISH COLUMBIA. CONSEQUENTLY...
WINDS ALOFT WILL BACK FROM NORTHWEST TO WESTERLY. THE QUASI-STATIONARY
BOUNDARY TO THE WEST WILL SLOWLY PROGRESS EAST AS A WARM FRONT WITH
INCREASING WESTERLY LOW LEVEL FLOW.
REGARDS TO SENSIBLE WEATHER...LOW CLOUDS...FOG AND PATCHY LIGHT
WINTRY PRECIPITATION TO CONTINUE MOST AREAS THIS MORNING. CONDITIONS
WILL BEGIN TO IMPROVE THIS AFTERNOON AS ISENTROPIC LIFT WEAKENS AND
YIELDS TO DOWNGLIDE. LIGHT SNOW WILL LIKELY PERSIST OVER HIGHER
ELEVATIONS OF SOUTHERN CARBON AND ALBANY COUNTIES THIS AFTERNOON
BEFORE ENDING BY EVENING. HIGH TEMPERATURES TODAY WILL REMAIN BELOW
SEASONAL NORMALS WITH 20S TO LOWER 30S. UNDER CLEARING SKIES AND
LIGHT WINDS...LOW TEMPERATURES TONIGHT WILL PLUMMET INTO THE SINGLE
DIGITS AND LOWER TEENS.
WEDNESDAY WILL BE THE TRANSITION DAY AS THE WESTERLY LOW LEVEL
WINDS INCREASE...SHOVING THE SURFACE BOUNDARY EAST INTO THE PLAINS
DURING THE AFTERNOON. DOWNSLOPE FLOW EAST OF THE LARAMIE RANGE WILL
PUSH TEMPERATURES INTO THE 30S...WITH 20S TO THE WEST. LOW
TEMPERATURES WEDNESDAY NIGHT WILL BE 5 TO 10 DEGREES MILDER ACROSS
THE PLAINS. HIGH TEMPERATURES THURSDAY WILL AVERAGE 10 DEGREES
WARMER THAN WEDNESDAY WITH 40S PREVALENT EAST OF THE LARAMIE
RANGE. WESTERLY WINDS WILL BE INCREASING THROUGHOUT THE DAY WITH
GUSTS TO 35 KT ACROSS PORTIONS OF THE LARAMIE RANGE AND NORTHERN
CARBON COUNTY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 201 AM MST TUE JAN 13 2015
IT WILL BE A MILD AND WINDY START TO THE EXTENDED AS DOWNSLOPE FLOW
INCREASES BEHIND A SHORTWAVE MOVING ACROSS EASTERN WY. H7 TEMPS ARE
PROGGED BETWEEN +2 AND +4 DEG C ALONG AND EAST OF THE SOUTH LARAMIE
RANGE FRI AFTN PER THE GFS AND ECMWF. THE MOISTURE-STARVED NATURE
OF THE AFOREMENTIONED WAVE WILL LIMIT ANY PRECIP CHANCES AND KEEP
SKIES PARTLY TO MOSTLY SUNNY. WITH GOOD COMPRESSIONAL WARMING VIA
FAVORABLE WESTERLY DOWNSLOPE WINDS...EXPECT SEASONABLE WARMTH TO
CONTINUE FRI. MEX/ECM MOS TEMPS ARE WELL INTO THE 50S OVER THE
PLAINS...WHICH IS REALISTIC FOR AREAS THAT DO NOT HAVE MUCH SNOW
LEFT. WINDS ARE ALSO AN ISSUE FOR FRI AND SAT. THE GFS H85 CAG-CPR
GRADIENT INCREASES TO AROUND 60 METERS LATE THU NIGHT AND REMAINS
HIGH THROUGH SAT...ALONG WITH H75 FLOW IN EXCESS OF 50 KT OVER THE
PRIMARY WIND CORRIDORS OF SOUTHEAST WY. STRONG SUBSIDENCE WOULD
SUGGEST STRONG GAP WINDS. BORA EVENT COULD OCCUR OVER THE PLAINS
ON SAT MORNING WITH WEAK LOW-LEVEL COLD ADVECTION. STILL EXPECT
THAT HIGH WIND HEADLINES WILL BE NEEDED IN THE COMING DAYS. TRICKY
TEMPERATURE FORECAST FOR SAT WITH A FEW KEY DIFFERENCES IN THE
MODELS. THE ECMWF DELAYS THE FRONTAL PASSAGE UNTIL SAT AFTN AND
KEEPS THE DEEPER COLD TO THE NORTH. THE GFS ON THE OTHER HAND
OFFERS A MORE SUBSTANTIAL COLD PUSH BY 12Z SAT WITH THERMAL
PROFILES REBOUNDING BY AFTN. DECIDED TO KEEP THINGS A LITTLE BELOW
CONSENSUS MOS SINCE THIS GUIDANCE MAY NOT BE HANDLING THE COLD
ADVECTION VERY WELL. A LACK OF MOISTURE THROUGH THE TROPOSPHERE
WILL LIMIT PRECIP CHANCES THROUGH SUN. MODELS QUITE A BIT
DIFFERENT THAN YESTERDAY CONCERNING A PACIFIC NORTHWEST SHORTWAVE
NEXT WEEK. LATEST RUNS SUGGEST THIS SYSTEM WILL BE A MORE
PROGRESSIVE OPEN WAVE...AND NOT REALLY AFFECTING US UNTIL MON.
DOES NOT LOOK LIKE A MAJOR STORM AT THIS TIME...BUT EXPECT
INCREASING PRECIP CHANCES AS WE HEAD INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 953 PM MST MON JAN 12 2015
LATEST HRRR FORECAST USED AS GUIDANCE ON THE 06Z TAFS. IFR/LIFR TO
CONTINUE FOR KCYS UNTIL THE WINDS SHIFT WEST. THAT DOES NOT LOOK
TO HAPPEN UNTIL MAYBE MID MORNING TUESDAY. KRWL LOOKING AT A
WIDESPREAD IFR EVENT OUT THERE THROUGH THE OVERNIGHT HOURS AS
WELL. ELSEWHERE...MVFR/VFR CONDITIONS SHOULD PERSIST. VFR
EVERYWHERE BY LATE MORNING AS WINDS TURN WESTERLY.
&&
.FIRE WEATHER...
ISSUED AT 200 AM MST TUE JAN 13 2015
THE ARCTIC AIR MASS THAT HAS GRIPED MUCH OF THE DISTRICT THE PAST FEW
DAYS WILL GRADUALLY RETREAT EAST. PERSISTENT LOW CLOUDS...FOG AND LIGHT
FREEZING DRIZZLE AND SNOW WILL PREVAIL THIS MORNING...WITH SLOWLY
IMPROVING CONDITIONS THIS AFTERNOON. COOL TEMPERATURES AND HIGH HUMIDITY
WILL PRECLUDE FORE WEATHER CONCERNS TODAY. WESTERLY LOW LEVEL WINDS WILL
BRING WARMER TEMPERATURES AND DRIER CONDITIONS FOR WEDNESDAY THROUGH
FRIDAY. MINIMUM HUMIDITY VALUES WILL DROP TO 25 TO 35 PERCENT BY THE
END OF THE WEEK. WINDS WILL INCREASE LATE IN THE WEEK...WITH THE
POSSIBILITY OF HIGH WINDS FOR WIND PRONE AREAS OF SOUTHEAST WYOMING
ON FRIDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...GCC
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
202 PM MST TUE JAN 13 2015
.SYNOPSIS...
AN EXITING WEATHER SYSTEM WILL AFFECT EASTERN ARIZONA THROUGH EARLY
WEDNESDAY...KEEPING CHANCES FOR SHOWERS ACROSS HIGHER TERRAIN AREAS
EAST OF PHOENIX. BEHIND THIS SYSTEM...MUCH DRIER AIR AND
LOCALLY BREEZY CONDITIONS WILL FILTER SOUTH INTO THE AREA. HOWEVER
AFTER THIS SYSTEM PASSES...HIGH PRESSURE WILL RETURN WITH SLOWLY
INCREASING TEMPERATURES THROUGH THE WEEKEND.
&&
.DISCUSSION...
A FAIRLY IMPRESSIVE RAIN BAND WITH EMBEDDED MODERATE TO EVEN HEAVY
SHOWERS MOVED OUT OF CENTRAL ARIZONA THIS MORNING INTO THE PHOENIX
AREA LATE IN THE MORNING...AND NOW IS PUSHING INTO THE MOUNTAINS TO
THE EAST. RAINFALL AMOUNTS WERE GENERALLY AROUND A TENTH OF AN
INCH...BUT THERE WERE A FEW LOCALIZED AMOUNTS OF A QUARTER INCH OR
MORE. THE UPPER TROUGH RESPONSIBLE FOR THIS RAIN IS NOW CENTERED
OVER NORTHWEST ARIZONA...BUT THE MAJORITY OF THE VERTICAL ASCENT IS
NOW SITUATED OVER SOUTHEAST ARIZONA NEAR A 120 KT UPPER JET STREAK.
DRY AIR ALOFT CAN BE SEEN ON WATER VAPOR IMAGERY TO THE SOUTH OF THE
UPPER LOW CENTER OVER SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA.
THIS DRY AIR ALONG WITH GRADUALLY INCREASING SUBSIDENT FLOW ALOFT
SHOULD KEEP OUR RAIN CHANCES FOR THE REST OF TODAY MAINLY LIMITED TO
HIGHER TERRAIN AREAS EAST OF PHOENIX. HOWEVER...VISIBLE IMAGERY DOES
SHOW A GOOD AMOUNT OF SUNSHINE TO THE WEST OF PHOENIX AND SOME CU
DEVELOPMENT OVER THE PAST HOUR. MAY SEE A FEW SHOWERS FORM IN THESE
SUNNY AREAS THROUGH THE REST OF THE AFTERNOON...BUT WITH VERY
LIMITED INSTABILITY...ANY DEVELOPMENT SHOULD REMAIN ISOLATED.
THE LATEST HI-RES HRRR AND WRF4KM RUNS SHOWS THE BULK OF THE RAIN
ENDING BY EARLY EVENING. THERE WILL BE A LINGERING CHANCE OF SOME
SHOWERS ACROSS EASTERN ARIZONA DURING THE OVERNIGHT HOURS AS THE
MAIN VORT MAX AND PVA ANOMALY CURRENTLY OVER NORTHWEST ARIZONA
SLIDES SOUTHEASTWARD. NOT WORRIED ABOUT THE CHANCES FOR MUCH SNOW
TONIGHT AS THE SYSTEM IS NOT UNUSUALLY COLD OR DEEP AND
HEIGHTS/THICKNESSES ALOFT INDICATE FREEZING LEVEL REMAINING AOA 7K
FT. THEREFORE...SNOW LEVELS SHOULD REMAIN WELL ABOVE POPULATION
CENTERS/TRANSPORTATION CORRIDORS WITH ONLY A DUSTING ON THE PEAKS OF
SRN GILA COUNTY LATER TONIGHT. AS THE LOW CENTER AND COLD CORE
SHIFTS OVER EAST-CENTRAL ARIZONA DURING THE DAYTIME HOURS
WEDNESDAY...WE SHOULD SEE SOME DIURNALLY FORCED SCT RAIN/SNOW SHOWER
REDEVELOPMENT WITHIN THE COLD CORE...BUT PRIMARILY LIMITED TO THE
WHITE MOUNTAINS OF ERN ARIZONA.
OPERATIONAL AND ENSEMBLE MEMBERS ARE IN VERY GOOD AGREEMENT THAT
STRONGER ZONAL PACIFIC JET ENERGY WILL FORCE A SIGNIFICANT
DOWNSTREAM PATTERN SHIFT OVER THE WESTERN HEMISPHERE DURING THE
LATTER HALF OF THIS WEEK INTO NEXT WEEK...UNLOCKING THE PREVAILING
BLOCKED FLOW INTO A MORE PROGRESSIVE QUASI-ZONAL PATTERN. SHORTWAVE
FEATURES OVER THE CONUS WILL BE EXCLUSIVELY LOW AMPLITUDE AND
RELEGATED TO THE NORTHERN STREAM WITH FLAT RIDGING PREDOMINATING THE
SWRN REGION. AS A RESULT...ENSEMBLE GUIDANCE EXHIBITS VERY LOW
FORECAST SPREAD WITH H5 HEIGHTS OSCILLATING AROUND A 580DM RANGE AND
H8 TEMPERATURES NEAR +10C. BASED ON HISTORICAL BIASES DURING SIMILAR
PATTERN EVOLUTION...HAVE HEDGED TOWARDS THE WARMEST GUIDANCE
PACKAGES YIELDING FORECAST HIGHS AT LEAST 5F ABOVE AVERAGE. EVEN
THIS APPROACH MAY BE CONSERVATIVE GIVEN A DRY ENVIRONMENT AND
POTENTIALLY SEVERAL DAYS OF FULL INSOLATION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AS OF 130 PM
MOST OF THE SHOWERS AND HEAVIER CONVECTIVE CELLS HAD PUSHED INTO
EAST OF THE GREATER PHOENIX AREA...AND WERE MOSTLY LOCATED TO THE
EAST OF THE TAF SITES. ISOLATED TO SCATTERED SHOWERS ARE STILL
POSSIBLE AT THE TAF SITES THRU 22Z OR SO...WITH CONTINUED CLEARING
EXPECTED INTO THE EVENING HOURS. CIGS WILL RISE AND SHOULD MOSTLY
RANGE FROM 5-8K FEET THROUGH 00Z OR SO BUT DO NOT EXPECT ANY OF THE
LOW CIGS THAT WERE SEEN EARLIER...UNLESS AN ISOLATED HEAVY SHOWER
WERE TO REDEVELOP LATER IN THE AFTERNOON. BY EARLY EVE...MOST CLOUD
DECKS WILL BE FEW TO SCT...AND WINDS WILL BECOME RATHER LIGHT
FAVORING THE WEST TO NORTHWEST AT THE TAF SITES.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT MOSTLY SUNNY SKIES THE REMAINDER OF THIS AFTERNOON...BUT
THERE MAY BE A FEW LINGERING CU WITH BASES GENLY BETWEEN 6-9K FEET.
EXPECT GENLY CLEAR SKIES BY EARLY EVENING...CONTINUING INTO THE DAY
ON WEDNESDAY. NORTH WINDS WILL LIKELY BE BREEZY THIS AFTERNOON AT
BLH BUT SHOULD QUIET DOWN QUICKLY AFTER 00Z. WINDS WILL CONTINUE TO
FAVOR THE NORTH ON WEDNESDAY BUT WITH SPEEDS MOSTLY AOB 12KT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
UPPER LEVEL RIDGING WILL TAKE SHAPE ACROSS THE REGION BY FRIDAY AND
REMAIN LARGELY IN PLACE THROUGH EARLY NEXT WEEK. THIS WILL RESULT IN
INCREASED TEMPERATURES WITH DAILY HIGH TEMPERATURES SEVERAL DEGREES
OR MORE ABOVE SEASONAL NORMALS EACH DAY. DESPITE THE PRESENCE OF
HIGH PRESSURE...HUMIDITIES WILL STAY A BIT ELEVATED EACH DAY WITH
MINIMUM RH VALUES MOSTLY BETWEEN 15 AND 25 PERCENT ACROSS THE
DESERTS. WINDS THROUGH THE PERIOD WILL BE LIGHT AND GENERALLY
DIURNAL IN NATURE.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN/MO
AVIATION...CB
FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
254 PM MST TUE JAN 13 2015
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 253 PM MST TUE JAN 13 2015
UPPER LEVEL LOW HAS JUST DROPPED BELOW THE UTAH STATE LINE INTO
ARIZONA AS MOIST SWLY FLOW CONTINUES TO PUMP MOISTURE INTO THE
REGION. ALONG AND JUST N OF INTERSTATE 70...FLOW HAS TURNED
EASTERLY WITH RADAR SHOWING RETURNS THAT ARE MORE CONVECTIVE IN
NATURE. ALL MODELS CONTINUE TO HIGHLIGHT A RATHER BROAD AREA OF
DEFORMATION THAT APPEARS TO BE PANNING OUT WITH SOME DISTINCT
BANDS OF PRECIP HAVING SET UP OVER THE REGION. UNDER THESE
BANDS...EXPECT PRECIP TO PICK UP SOME BUT COVERAGE LOOKS TO BE
SOMEWHAT LIMITED SO DO NOT ANTICIPATE MUCH OF AN INCREASE TO RAIN
AND SNOW TOTALS. SPEAKING OF...MANY REPORTS OF DECENT SNOWFALL
WITH MONTEZUMA COUNTY REPORTING 6 TO 8 INCHES...LA PLATA COUNTY
CAME IN WITH 6 TO 10 INCHES AND ARCHULETA COUNTY REPORTS 8 TO 12
INCHES IN SOME SPOTS. NAM12 CONTINUES TO SHOW RATHER WIDESPREAD
PRECIP FOR THE SAN JUANS AND AREAS SOUTH THROUGH TONIGHT BUT THIS
LOOKS WAY OVERDONE. HRRR IS MUCH MORE CONSERVATIVE AND ALSO SHIFTS
THE BEST PRECIP SOUTHWARD INTO NEW MEXICO. VISIBLE SATELLITE DOES
SHOW PLUME OF MOISTURE STEADILY DROPPING EAST AND SOUTH SO THINK
HRRR HAS THE BEST HANDLE ON CURRENT SITUATION. FOR THE REMAINDER
OF THE DAY THEN...A FEW MORE INCHES...1 TO 3...FOR THE MOUNTAINS
WITH VALLEYS POSSIBLY SEEING ANOTHER INCH OR TWO. CURRENT HIGHLIGHTS
CONTINUE THROUGH 6PM SO WILL KEEP THEM GOING.
FOR WEDNESDAY...HIGH PRESSURE BUILDS IN WITH LESS CLOUDS UP NORTH
AND MORE DOWN SOUTH WITH CONDITIONS IMPROVING THROUGH THE DAY. ONLY
BIG QUESTION MARK WILL BE FOG AND HOW THICK AND HOW WIDESPREAD IT
WILL BE AS AMPLE MOISTURE WILL REMAIN IN THE ATMOSPHERE DUE TO THE
EVAPORATING SNOWFALL ESPECIALLY SOUTH. TEMPS WILL STAY NEAR
NORMAL THROUGH THE PERIOD WITH A WARMUP TOWARDS THE END OF THE
WEEK.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 253 PM MST TUE JAN 13 2015
A PROGRESSIVE FLOW WILL BRING A SERIES OF RIDGES AND TROUGHS
ACROSS THE CONUS DURING THE LONG TERM PERIOD. FOR THE MOST
PART...OUR FORECAST AREA WILL BE SOUTH OF...OR ON THE SOUTHERN
EDGE AT BEST OF ANY WEATHER ASSOCIATED WITH ANY DISTURBANCE THAT
PASSES. ALSO TIMING WILL REMAIN DIFFICULT FOR THESE FAST MOVING
WAVES.
ON THU AT THE START OF THE PERIOD. THE AREA WILL BE UNDER A
FLATTENING RIDGE THAT WASHES OUT AS IT GETS PUSHED EAST THU NIGHT.
A SHORTWAVE TROUGH WILL MOVE INTO THE PACIFIC NORTHWEST ON
FRIDAY...THEN WILL BRUSH OUR FORECAST AREA FRI NIGHT INTO SAT.
EXCEPT FOR THE LATEST/12Z ECMWF...THE MODELS HAVE INDICATED THAT
THIS WAVE WILL JUST BARELY BRUSH OUR NORTHEAST CORNER...WITH THE
FLOW MAINLY STAYING ZONAL. THE 12Z EC HOWEVER IS MORE AMPLIFIED
THAN EARLIER RUNS WHICH COULD MEAN A BETTER CHANCE OF SNOW...STILL
STAYING MAINLY OVER THE NORTH AND CENTRAL CO MOUNTAINS. WILL KEEP
THE GENERALLY DRY FORECAST FOR NOW BEFORE BUYING OFF ON THIS
STRENGTHENING TREND.
A RIDGE WILL BUILD BEHIND THIS WAVE ON SUN...THEN FLATTEN AGAIN
DURING THE EARLY PART OF THE WORK WEEK AS WAVES MOVES INTO WESTERN
NOAM. EXPECT TEMPERATURES TO RUN JUST A LITTLE ABOVE NORMAL FOR
THE MOST PART. THE MEX AND ECE GUIDANCE NUMBERS SHOW RATHER BIG
DIFFERENCES...WITH THE MEX PROBABLY TOO WARM AND ECE TOO COOL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1106 AM MST TUE JAN 13 2015
WIDESPREAD SNOW WILL CONTINUE OVER THE SOUTHERN HALF OF THE
FORECAST AREA THROUGH THIS AFTERNOON...BEFORE DIMINISHING
THROUGHOUT THE EVENING. ALONG THE I-70 CORRIDOR...WIDESPREAD
PRECIPITATION HAS BEGUN TO WIND DOWN. HOWEVER ISOLD-SCT
-SHSN/-SHRA WILL PERSIST THROUGH THIS AFTERNOON. AREAS OF FOG AND
LOW CLOUDS WILL CONTINUE TO BE A CONCERN NORTH OF INTERSTATE
70...WITH THE FOG THINNING THROUGH THE AFTERNOON. AS A
RESULT...FLIGHT CONDITIONS WILL GENERALLY BE POOR WITH SOME
IMPROVEMENT MAINLY OVER THE NORTH DURING THE AFTERNOON. MOUNTAINS
WILL BE OBSCURED...ESPECIALLY SOUTH.
AS THE STORM MOVES OFF...AND AS SKIES BEGIN TO CLEAR OFF LATE THIS
EVENING AND OVERNIGHT...AREAS OF FOG AND LOW CLOUDS REFORM AND
SPREAD ACROSS MANY OF THE VALLEY AREAS. SOME FOG WILL PERSIST
THROUGH WED MORNING...BUT SHOULD DIMINISH AFTER 15Z WED.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ012-
014-020.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ009-
017>019-021>023.
UT...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR UTZ022-
029.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR UTZ028.
&&
$$
SHORT TERM...TGR
LONG TERM...EH
AVIATION...EH
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1158 AM CST TUE JAN 13 2015
.SYNOPSIS...
ISSUED AT 310 AM CST TUE JAN 13 2015
SURFACE HIGH PRESSURE CENTERED NORTH OF LA CROSSE WAS PROVIDING
CLEAR SKIES AND COLD CONDITIONS OVER MOST OF THE AREA EARLY THIS
MORNING. AN AREA OF LAKE GENERATED STRATUS WITH SNOW SHOWERS WAS
EVIDENT ON FOG CHANNEL IMAGERY AND SURFACE OBSERVATIONS OVER
NORTHERN IL...WHICH HAS BEEN CREEPING WESTWARD OVER THE PAST SEVERAL
HOURS. AT 08Z...THE LEADING EDGE OF THESE CLOUDS WAS ROUGHLY FROM
SAVANNA TO KEWANEE. WEAK RADAR RETURNS AND SURFACE OBSERVATIONS
INDICATED FLURRIES HAVE REACHED AS FAR WEST AS PRINCETON IL TO
STERLING IL. TEMPERATURES VARIED WIDELY...MOSTLY IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO WHERE SKIES CLEAR...TO THE UPPER
SINGLE DIGITS AND TEENS UNDER THE CLOUD COVER AND STRONGER
NORTHERLY FLOW ACROSS THE EAST. ALOFT...A NW FLOW PREVAILED WITH A
SHORTWAVE OF INTEREST MOVING ACROSS SASKATCHEWAN AND EASTERN MT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CST TUE JAN 13 2015
TRENDS WITH TEMPERATURES AND CLOUD COVER DOMINATE THE IMMEDIATE
SHORT TERM. FOCUS THEN TURNS TO THE EFFECTS OF THE SHORTWAVE PUSHING
THROUGH LATER TONIGHT.
AS THE SURFACE HIGH CONTINUES EASTWARD...THE CURRENT SURFACE
THROUGH 925 MB EASTERLY FLOW AND TRAJECTORY OF MOISTURE OFF LAKE
MI WILL BECOME LESS FAVORABLE THIS MORNING. THIS BIG QUESTION WILL
BE HOW FAR WEST THE CLOUD FIELD ADVANCES BEFORE DISSIPATING UNDER
THE LARGELY SUBSIDENT...CONFLUENT MID LEVEL FLOW. THE ROUGH
AGREEMENT IN THE 06Z WRF AND RAP MODELED MOISTURE FIELDS IN THE
900 TO 950 MB LAYERS...THAT HAD A DECENT HANDLE ON THE CURRENT
TRENDS...INDICATE THE CLOUDS SHOULD ADVANCE TO AT LEAST THE MS
RIVER INTO EXTREME EASTERN IA TOWARD MID MORNING BEFORE THINNING
OUT ALTOGETHER BY NOON AND HAVE FOLLOWED THIS TREND. FOR
NOW...WILL HAVE FLURRIES ENDING BEFORE SUNRISE ONLY OVER NW
IL...BUT WILL WATCH RADAR AND OBSERVATIONS OBSERVATIONS CLOSELY
FOR THE POSSIBLE NEED TO CONTINUE LONGER AND POSSIBLY REACH INTO
EASTERN IA.
THROUGH THE REST OF THE DAY...MOSTLY SUNNY SKIES AND LIGHT WINDS
WILL LIMIT MIXING AND PREVIOUS FORECAST HIGHS IN THE MID TO UPPER
TEENS LOOK REASONABLE.
TONIGHT...WEAK LIFT AND MID LEVEL MOISTURE WITH THE INCOMING
SHORTWAVE SHOULD LEAD TO INCREASING CLOUDS OVERNIGHT. THE CURRENT
TIMING SUGGESTS THIS MAY NOT OCCUR UNTIL LATE OVER THE EAST...WHERE
THE LIGHT WINDS AND SNOW COVER WILL AGAIN FAVOR LOWS NEAR OR A FEW
DEGREES BELOW ZERO...WITH A RAPID DROP OFF POSSIBLE IN THE EVENING.
IN THE WEST...INCREASING CLOUDS AND AT LEAST LIGHT SW WINDS SHOULD
HOLD MINS IN THE SINGLE DIGITS ABOVE ZERO...WITH STEADY TO POSSIBLY
RISING TEMPERATURES TOWARD MORNING. THE WEAK MID LEVEL LIFT REACHES
INTO THE NORTHWEST HALF OF THE FORECAST AREA TOWARD MORNING...BUT
WITH THE DEEP LAYER OF DRY AIR AT THE SURFACE...LIKELY THROUGH AT
LEAST 800 MB...PRECIPITATION DOES NOT LOOK LIKELY. WILL MENTION
POSSIBLE FLURRIES IN THE FAR NW TOWARD SUNRISE WHERE THE LIFT
LOOKS TO BE MAXIMIZED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 310 AM CST TUE JAN 13 2015
FORECAST FOCUS ON A WELCOME WARMING TREND THROUGH THIS EXTENDED
PERIOD ALONG WITH LITTLE IF ANY PRECIPITATION.
WEDNESDAY...A WEAK UPPER LEVEL TROUGH WILL SWING THROUGH THE REGION
IN THE MORNING. HOWEVER...FORECAST SOUNDINGS INDICATE THE COLUMN IS
MOISTURE STARVED AND MODELS SUGGEST FORCING IS QUITE WEAK...SO WILL
HAVE ONLY 20 POPS. MAY BE ABLE TO SQUEEZE OUT SOME FLURRIES BUT THE
WORST CASE SCENARIO WOULD BE A DUSTING IN A FEW SPOTS. NONE OF THE
OPERATIONAL MODELS PAINT ANY QPF IN THE DVN CWA...KEEPING THE BULK
OF THE QPF TO OUR NORTH WHERE THE BETTER FORCING WILL EXIST. MAXIMUM
TEMPERATURES WILL PUSH INTO THE LOWER TO MID 20S.
THURSDAY THROUGH SATURDAY...UPPER FLOW TRANSITIONS TO A MORE ZONAL
FLOW BRINGING A MILDER PACIFIC AIRMASS INTO THE MIDWEST. THIS WILL
ALLOW FOR A WARMING TREND AND BY THE TIME WE GET TO FRIDAY AND
SATURDAY HIGH TEMPERATURES WILL BE SOARING WELL INTO THE 30S AND 40S.
MUCH OF THE SNOW ON THE GROUND WILL BE MELTED BY THEN.
SUNDAY THROUGH MONDAY...A COUPLE OF CLIPPER SYSTEMS TRACK TO OUR
NORTH WITH THE OPERATIONAL MODELS KEEPING THE BULK OF THE
PRECIPITATION NORTH OF THE DVN CWA. HOWEVER...CAN`T RULE OUT
SOMETHING SNEAKING INTO THE CWA ESPECIALLY IF THE SYSTEMS TRACK
FARTHER SOUTH THAN CURRENTLY INDICATED. BEHIND EACH STORM SYSTEM A
COLD FRONT DROPS INTO THE CWA KNOCKING OUR HIGH TEMPERATURES BACK DOWN
INTO THE 30S...BUT THE CONSENSUS MODELS MAY NOT BE COLD ENOUGH FOR
LATER SHIFTS TO MONITOR.
HAASE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1138 AM CST TUE JAN 13 2015
MVFR STRATOCU DECK HANGING ON ALONG AND EAST OF DBQ AND TRYING TO
PUSH TOWARD THE MLI SITE FROM THE EAST. BOTH SITES MAY STAY JUST
TO THE WEST OF THE BKN-OVC COVERAGE...BUT TOO CLOSE FOR COMFORT
AND WILL HAVE TO USE A TEMPO GROUP FOR AT LEAST A BKN MVFR DECK
SCRAPING THESE SITES THROUGH MID AFTERNOON. ANY LINGERING SOLID
MVFR DECK MAY HAVE A FEW FLURRIES EMBEDDED IN IT THIS AFTERNOON AS
WELL. LIGHT EASTERLY SFC WINDS ACRS THE AREA THIS AFTERNOON UNDER
PASSING RIDGE CENTER CURRENTLY OVER SOUTHERN WI INTO NORTHEASTERN
IL. BEHIND THE RIDGE...MAINLY VFR LEVEL STRATOCU CLOUDS CURRENTLY
ACRS THE PLAINS WILL MOVE EASTWARD ACRS THE TAF SITES AFTER
MIDNIGHT AND INTO WED MORNING. SOME CHC FOR EVEN A LOWER DECK IN
THE MVFR REALM WITH EMBEDDED FLURRIES OR EVEN LIGHT SNOW SHOWERS
WED MORNING AT CID AND DBQ. AN APPROACHING SFC FRONT ASSOCIATED
WITH THESE CLOUDS AND LIGHT PRECIP CHANCES WILL SWITCH THE SFC
WINDS TO THE SOUTHWEST WED MORNING AHEAD OF THE BOUNDARY BUT STILL
REMAIN ON THE LIGHT SIDE. ..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...HAASE
AVIATION...12
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1154 AM CST TUE JAN 13 2015
.DISCUSSION...
FOR 18Z TAF ISSUANCE.
&&
.AVIATION...
SFC OBS/VIS IMAGERY DEPICTS LOW CLOUDS CONTINUING TO SOCK IN THE
FORECAST AREA ATTM...AND GFS FORECAST SOUNDINGS/TIME-HEIGHT
SECTIONS SHOW THIS TREND TO CONTINUE THROUGH TONIGHT (NAM IS A
LITTLE MORE OPTIMISTIC ON CLEARING BUT WAS ALSO THIS WAY YESTERDAY
MORNING). MOST SITES NOW MVFR WITH CIGS POKING JUST ABOVE 1K FEET
BUT KLFT SHOWS A DROP BACK TO 700 FEET...LIKELY CAUSED BY INCOMING
SHORTWAVE-INDUCED LIGHT RAIN/DRIZZLE. EXPECT THIS DROP TO BE
TEMPORARY IN NATURE AND HAVE KEPT THE OVERRIDING THEM OF MVFR
GOING THERE AS WELL. CEILINGS LIKELY TO DROP BELOW 1K AGAIN THIS
EVENING. OTHER AVIATION ISSUE WILL BE NRLY WINDS AS SPEEDS
EXPECTED TO RUN AOA 10 KNOTS AT THE SRN SITES THROUGH THE AFTERNOON.
25
&&
.PREV DISCUSSION... /ISSUED 1049 AM CST TUE JAN 13 2015/
UPDATE...
WDSPRD CLOUD COVER WITH A BAND OF LT SPRINKLES/PATCHY DZ MOVING E
ACRS SW LA AND LOWER SE TX COURTESY OF A WEAK DISTURBANCE CROSSING
THE REGION. ONLY MODEL TO CAPTURE THIS HAS BEEN THE HRRR WITH
OTHER MODELS UNABLE TO DISCERN THE FEATURE. TWEAKED POPS JUST
SLIGHTLY AND ADDED PATCHY DZ TO THE WX GRIDS...FM CNTL LA TO LOWER
SE TX THIS MORNING THEN OVER THE ACADIANA REGION THIS AFTN.
OTHERWISE...A FAIRLY STOUT CAP OVER THE AREA THIS MORNING PER THE
12Z KLCH SOUNDING WITH MOISTURE TRAPPED BELOW THE INVERSION...AND
THIS SHOULD KEEP SKIES CLOUDY THROUGH THE DAY. LATEST STLT IMAGERY
SHOWS CLEARING LINE WELL NORTH OF THE AREA ACRS SWRN ARK AND
ALTHOUGH THIS COULD WORK SOUTH ACRS NRN LA...DO NOT THINK IT WILL
QUITE REACH CNTL LA AND THE LAKES REGION OF SE TX. WITH CLOUDY
SKIES HOLDING ON...TWEAKED THE HOURLY TEMPS AND ADJUSTED MAX TEMPS
DOWN A FEW DEGREES. 24
PREV DISCUSSION... /ISSUED 559 AM CST TUE JAN 13 2015/
DISCUSSION...
FOR THE 12Z TAF PACKAGE.
AVIATION...
MIX OF IFR/MVFR CIGS THIS MORNING ALL TERMINALS...WITH NORTH TO
NORTHEAST WIND HOLDING STEADY BETWEEN 10-15KT. FCST TIME
HEIGHTS/SOUNDINGS POINT TWD GRADUALLY LIFTING CIGS TODAY...BUT
REMAINING IN MVFR OWING TO THE STNG FRONTAL INVERSION NEAR 2K FT.
CIGS PROGGED TO ERODE THIS EVENING AS RELATIVELY DRIER AIR ADVECTS
IN FROM THE NORTH.
13
PREV DISCUSSION... /ISSUED 321 AM CST TUE JAN 13 2015/
DISCUSSION...EVENING LCH SOUNDING SHOWING A SUBSTANTIAL FRONTAL
INVERSION OF 15F DEGREES BEGINNING AT AROUND 2K FEET. NORTHERLY
FLOW AT AND BELOW INVERSION MAINTAINING COLD AIR ADVECTION...WITH
WINDS TRENDING MILD ABOVE ON A WESTERLY ABOVE. EXPANSIVE LOW
LEVEL CLOUDINESS DEPICTED BY SATELLITE/SURFACE OBS OVER MUCH OF
THE SOUTH AND SOUTHEAST CONUS LOCKED BENEATH AFOREMENTIONED
THERMAL INVERSION. UNFORTUNATELY...LIMITED SYNOPTIC CHANGE SUGGESTED
INTO WEDNESDAY...SO ANTICIPATING CLOUD COVER TO BE MAINTAINED.
THUS WITH LIMITED SUN TODAY AND CAA CONTINUING...EXPECTING LITTLE
IN THE WAY OF A WARMUP FROM EARLY MORNINGS LOWS.
COLD 1045 MB SURFACE HIGH NOW POSITIONED OVER THE UPPER MIDWEST
WILL SLOWLY SETTLE SOUTH OVER THE NEXT FEW DAYS WHILE MODIFYING.
FEATURE WILL MAINTAIN UNSEASONABLY COOL TEMPS. WILL KEEP A CHANCE
FOR A FEW SHOWERS PREDOMINANTLY OVER THE COASTAL WATERS BOTH
WEDNESDAY AND THURSDAY AS MOISTURE RE-EXPANDS NORTHWARD IN ADVANCE
OF A SHARPLY POSITIVELY TILTED MID-LEVEL TROF DROPPING THROUGH THE
PLAINS. MOISTURE THEN GETS SHUNTED SOUTH WITH PASSAGE OF THE
TROF...FOLLOWED BY A DRY NORTH TO NORTHWEST FLOW IN THE COLUMN
YIELDING A DRY PATTERN THROUGH THE REMAINDER OF THE WEEK.
MARINE... STRONG HIGH PRESSURE EXTENDING SOUTH INTO THE NEAR
COASTAL WATERS WILL MAINTAIN A MODERATE OFFSHORE FLOW THROUGH
THURSDAY. AN APPROACHING UPPER LEVEL DISTURBANCE WILL BRING A
CHANCE FOR A FEW SHOWERS BOTH WEDNESDAY AND THURSDAY. HIGH
PRESSURE WILL THEN AGAIN BECOME REESTABLISHED THROUGH THE
REMAINDER OF THE WEEK WITH A DRY WEATHER PATTERN RETURNING...WHILE
WINDS WILL RELAX AS SURFACE HIGH PRESSURE SETTLES SOUTH TO NEAR
THE COAST.
23
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 46 36 47 38 53 / 10 10 20 30 20
KBPT 47 38 46 38 52 / 10 10 20 30 10
KAEX 42 33 46 35 52 / 10 10 20 20 10
KLFT 46 36 48 39 51 / 10 10 20 30 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT EXERCISE CAUTION UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM...COASTAL WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM...
WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60
NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60
NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL
CITY LA FROM 20 TO 60 NM.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSLAKECHARLES
WWW.TWITTER.COM/NWSLAKECHARLES
WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1049 AM CST TUE JAN 13 2015
.UPDATE...
WDSPRD CLOUD COVER WITH A BAND OF LT SPRINKLES/PATCHY DZ MOVING E
ACRS SW LA AND LOWER SE TX COURTESY OF A WEAK DISTURBANCE CROSSING
THE REGION. ONLY MODEL TO CAPTURE THIS HAS BEEN THE HRRR WITH
OTHER MODELS UNABLE TO DISCERN THE FEATURE. TWEAKED POPS JUST
SLIGHTLY AND ADDED PATCHY DZ TO THE WX GRIDS...FM CNTL LA TO LOWER
SE TX THIS MORNING THEN OVER THE ACADIANA REGION THIS AFTN.
OTHERWISE...A FAIRLY STOUT CAP OVER THE AREA THIS MORNING PER THE
12Z KLCH SOUNDING WITH MOISTURE TRAPPED BELOW THE INVERSION...AND
THIS SHOULD KEEP SKIES CLOUDY THROUGH THE DAY. LATEST STLT IMAGERY
SHOWS CLEARING LINE WELL NORTH OF THE AREA ACRS SWRN ARK AND
ALTHOUGH THIS COULD WORK SOUTH ACRS NRN LA...DO NOT THINK IT WILL
QUITE REACH CNTL LA AND THE LAKES REGION OF SE TX. WITH CLOUDY
SKIES HOLDING ON...TWEAKED THE HOURLY TEMPS AND ADJUSTED MAX TEMPS
DOWN A FEW DEGREES. 24
&&
.PREV DISCUSSION... /ISSUED 559 AM CST TUE JAN 13 2015/
DISCUSSION...
FOR THE 12Z TAF PACKAGE.
AVIATION...
MIX OF IFR/MVFR CIGS THIS MORNING ALL TERMINALS...WITH NORTH TO
NORTHEAST WIND HOLDING STEADY BETWEEN 10-15KT. FCST TIME
HEIGHTS/SOUNDINGS POINT TWD GRADUALLY LIFTING CIGS TODAY...BUT
REMAINING IN MVFR OWING TO THE STNG FRONTAL INVERSION NEAR 2K FT.
CIGS PROGGED TO ERODE THIS EVENING AS RELATIVELY DRIER AIR ADVECTS
IN FROM THE NORTH.
13
PREV DISCUSSION... /ISSUED 321 AM CST TUE JAN 13 2015/
DISCUSSION...EVENING LCH SOUNDING SHOWING A SUBSTANTIAL FRONTAL
INVERSION OF 15F DEGREES BEGINNING AT AROUND 2K FEET. NORTHERLY
FLOW AT AND BELOW INVERSION MAINTAINING COLD AIR ADVECTION...WITH
WINDS TRENDING MILD ABOVE ON A WESTERLY ABOVE. EXPANSIVE LOW
LEVEL CLOUDINESS DEPICTED BY SATELLITE/SURFACE OBS OVER MUCH OF
THE SOUTH AND SOUTHEAST CONUS LOCKED BENEATH AFOREMENTIONED
THERMAL INVERSION. UNFORTUNATELY...LIMITED SYNOPTIC CHANGE SUGGESTED
INTO WEDNESDAY...SO ANTICIPATING CLOUD COVER TO BE MAINTAINED.
THUS WITH LIMITED SUN TODAY AND CAA CONTINUING...EXPECTING LITTLE
IN THE WAY OF A WARMUP FROM EARLY MORNINGS LOWS.
COLD 1045 MB SURFACE HIGH NOW POSITIONED OVER THE UPPER MIDWEST
WILL SLOWLY SETTLE SOUTH OVER THE NEXT FEW DAYS WHILE MODIFYING.
FEATURE WILL MAINTAIN UNSEASONABLY COOL TEMPS. WILL KEEP A CHANCE
FOR A FEW SHOWERS PREDOMINANTLY OVER THE COASTAL WATERS BOTH
WEDNESDAY AND THURSDAY AS MOISTURE RE-EXPANDS NORTHWARD IN ADVANCE
OF A SHARPLY POSITIVELY TILTED MID-LEVEL TROF DROPPING THROUGH THE
PLAINS. MOISTURE THEN GETS SHUNTED SOUTH WITH PASSAGE OF THE
TROF...FOLLOWED BY A DRY NORTH TO NORTHWEST FLOW IN THE COLUMN
YIELDING A DRY PATTERN THROUGH THE REMAINDER OF THE WEEK.
MARINE... STRONG HIGH PRESSURE EXTENDING SOUTH INTO THE NEAR
COASTAL WATERS WILL MAINTAIN A MODERATE OFFSHORE FLOW THROUGH
THURSDAY. AN APPROACHING UPPER LEVEL DISTURBANCE WILL BRING A
CHANCE FOR A FEW SHOWERS BOTH WEDNESDAY AND THURSDAY. HIGH
PRESSURE WILL THEN AGAIN BECOME REESTABLISHED THROUGH THE
REMAINDER OF THE WEEK WITH A DRY WEATHER PATTERN RETURNING...WHILE
WINDS WILL RELAX AS SURFACE HIGH PRESSURE SETTLES SOUTH TO NEAR
THE COAST.
23
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 46 36 47 37 / 10 10 20 30
KBPT 47 38 46 38 / 10 10 20 30
KAEX 42 33 46 35 / 10 10 20 20
KLFT 46 36 48 38 / 10 10 20 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT EXERCISE CAUTION UNTIL 6 PM CST THIS EVENING FOR
COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM-
COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20
NM-COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA OUT 20 NM-WATERS FROM INTRACOASTAL
CITY TO CAMERON LA FROM 20 TO 60 NM-WATERS FROM CAMERON LA
TO HIGH ISLAND TX FROM 20 TO 60 NM-WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1211 PM EST TUE JAN 13 2015
.UPDATE...
ISSUED AT 1049 AM EST TUE JAN 13 2015
PRIMARY CHANGES TO THE FORECAST THIS MORNING ALREADY HINTED AT BY
OVERNIGHT FORECASTER...AS CLOUD COVER OVER NORTHERN LAKE MICHIGAN
HAS GRADUALLY PUSHED NORTH...WITH MOSTLY CLOUDY-CLOUDY SKIES
EXTENDING FROM MNM-ESC-ERY. HAVE SLOWED THE IMPROVING SKY TREND
SOMEWHAT WITH THESE LOCATIONS LIKELY TO REMAIN BELOW STRATUS FOR
MUCH OF THE DAY. THIS ALSO NECESSITATED SOME NEAR TERM TEMPERATURE
ADJUSTMENTS /UPWARD/...BUT INHERITED AFTERNOON HIGHS STILL
GENERALLY LOOK GOOD WITH PERHAPS A SMALL DOWNWARD ADJUSTMENT
NEEDED FOR THESE CLOUDY LOCATIONS. OTHERWISE...PLENTY OF SUN AND
RAPIDLY REBOUNDING TEMPERATURES EXPECTED THROUGH AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EST TUE JAN 13 2015
ALTHOUGH ARCTIC SFC HIGH PRES IS CENTERED OVER WRN WI EARLY THIS
MORNING...CLOUDS HAVE BEEN SLOW TO CLEAR OUT OF UPPER MI DURING THE
NIGHT. THIS SLOW CLEARING IS A RESULT OF WINDS JUST OFF THE SFC IN
THE STRATUS BEARING LAYER BEING SO LIGHT. LATEST RUC ANALYSIS SHOWS
CENTER OF THE 925MB HIGH PRES CIRCULATION OVER SCNTRL UPPER MI.
WITH THIS CIRCULATION DRIFTING ESE...CLEARING IS NOW PROGRESSING
FAIRLY STEADILY THRU NW AND CNTRL UPPER MI. MEANWHILE...TO THE S OF
THE 925MB CIRCULATION CENTER...E/SE FLOW OFF LAKE MI HAS BROUGHT
STRATUS N AND W TO KMNM RECENTLY. WHERE SKIES HAVE BEEN CLEAR
LONGEST...NEAR THE WI BORDER...TEMPS EARLY THIS MORNING ARE IN THE
-20 TO -25F RANGE. WHERE CLOUDS CLEAR OUT BEFORE SUNRISE...TEMPS
WILL STILL HAVE AN OPPORTUNITY TO PLUMMET.
WITH THE HIGH SHIFTING SE...STRENGTHENING LOW-LEVEL SW FLOW QUICKLY
TAKES OVER TODAY...AND THIS WILL PUSH REMAINING STRATUS OUT OF THE
FCST AREA OVER THE NEXT SEVERAL HRS. HOWEVER...WILL NEED TO WATCH
THE STRATUS THAT HAS EXPANDED OFF LAKE MI INTO ERN WI. THESE CLOUDS
AND POSSIBLY SOME FLURRIES MAY SPREAD NE FROM WI TO KESC/KISQ/KERY
TODAY. RIGHT NOW...FCST REFLECTS AN OPTIMISTIC SKY CONDITION IN THAT
AREA...BUT TRAJECTORIES ARE VERY CLOSE TO HAVING JUST ENOUGH
SOUTHERLY COMPONENT TO RESULT IN CLOUDY CONDITIONS FOR A GOOD PART
OF THE DAY ACROSS THE SE FCST AREA. OBVIOUSLY...CLOUD TRENDS WILL
NEED TO BE MONITORED THIS MORNING. ALTHOUGH TEMPS WILL REACH THE
TEENS TODAY...INCREASING WINDS WILL ADD A CHILL TO THE AIR.
TONIGHT...SHORTWAVE WILL SWING SE...REACHING THE UPPER LAKES EARLY
WED MORNING. RIBBON OF DEEP LAYER FORCING AND WAA/ISENTROPIC ASCENT
OFFERS THE POTENTIAL FOR SOME -SN TONIGHT...AND ALL MODEL GUIDANCE
HAS GENERALLY TRENDED TOWARD SHOWING MORE COVERAGE OF PCPN. HAVE
THUS RAISED POPS TO HIGH CHC ACROSS THE W HALF OVERNIGHT. WITH ONLY
MODEST ISENTROPIC ASCENT INDICATED...PCPN WILL BE ON THE LIGHT
SIDE...ONLY A DUSTING OF SNOW (LESS THAN 1 INCH). TEMPS WILL BE A
CHALLENGE TONIGHT AS MOSTLY CLEAR SKIES EARLY MAY ALLOW MORE
SHELTERED INTERIOR LOCATIONS TO DIP TO ZERO OR BELOW BEFORE CLOUDS
INCREASE. OTHERWISE...SINGLE DIGITS INTERIOR TO CLOSER TO 10F ALONG
LAKE SUPERIOR SHOULD BE THE RULE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 446 AM EST TUE JAN 13 2015
SHORTWAVE CROSSING NORTHERN ONTARIO PROPELS WEAK COLD FRONT OVER
UPR MICHIGAN WEDNESDAY MORNING. GREATEST LIFT AND MID-LEVEL MOISTURE
POINT TO LINGERING LGT SNOW IN THE MORNING OVER THE SOUTH AND EAST
CWA. LAKE EFFECT SNOW LIKELY IN THE MORNING OVER KEWEENAW WITH WNW
WINDS AND MOISTURE TO H9 WITH TEMPS AT H9 BLO -14C...PLACING MOST
OF THE MOIST LAYER WITHIN THE DGZ. SHARP INVERSION PRESENT BLO 5KFT
WILL LIMIT INTENSITY BUT COULD SEE UP TO A COUPLE INCHES OF FLUFFY
ACCUMS THROUGH MIDDAY BEFORE BACKING WINDS AND SUBSIDENCE/DRYING
DIMINISH THE LES. AWAY FM KEWEENAW...SUB H9 MOISTURE REMAINS IN WAKE
OF THE FROPA BUT IT WILL PROBABLY TRY TO AT LEAST PARTIALLY CLEAR OUT
DURING THE AFTN. MIXING TO H925 SUPPORTS HIGHS IN THE MID TEENS TO
LOW 20S.
SFC LOW SLIDING SOUTHEAST FM THE CANADIAN PRAIRIES PUSHES A WARM
FRONT TOWARD UPR LAKES ON WEDNESDAY NIGHT. MID-LEVEL MOISTURE
ADVECTION H8-H6 COULD PRODUCE PATCHY LGT SNOW OVER MAINLY THE NORTH
CLOSER TO THE WARM FRONT AND WHERE SOUNDINGS SHOW GREATER SATURATION
BLO H8. SW WINDS IN WAKE OF WARM FRONT RAMP UP WITH GUSTS OVER 20
KTS NEAR LK SUPERIOR FM KEWEENAW TO NCNTRL UPR MICHIGAN. WINDS BECOME
MORE WESTERLY ON THURSDAY AND COULD BE QUITE BREEZY ON THE MORE
EXPOSED KEWEENAW PENINSULA AS SFC LOW CROSSING NORTHERN ONTARIO
DEEPENS BLO 995MB. SOUNDINGS SHOW WELL MIXED PROFILE THROUGH H9 WITH
WINDS UP TO 35 KTS. DUE TO A WELL MIXED BLYR AND ONLY MARGINAL
OVER-WATER INSTABILITY...CHANCES OF ANY LES IN WAKE OF SFC LOW SEEM
MINIMAL OVER THE KEWEENAW PENINSULA ON THURSDAY. MIXING TO 925-900MB
ON THURSDAY YIELDS MAX TEMPS INTO THE UPR 20S IF NOT LOWER 30S.
LOWEST TEMPS IN MID 20S EXPECTED DOWNSTREAM OF ICE COVERED BAY OF
GREEN BAY AND NORTHERN LK MICHIGAN.
COLDER AIR DOES FINALLY ARRIVE LATER THURSDAY NIGHT INTO FRIDAY
MORNING AS THE LOW TRACKS OVER QUEBEC. EVEN WITH H925/H85 TEMPS ON
GFS FALLING TO -18C/-16C BY 12Z ON FRIDAY OVER EASTERN LK SUPERIOR
WITH ECMWF SLIGHTLY LOWER AT H85...LES SHOULD BE DAMPENED BY DRY SUB
CLOUD LAYER AS SFC HIGH AND ANTICYCLONIC FLOW BUILD ACROSS LK
SUPERIOR FM NORTHERN ONTARIO. RAN WITH SMALL CHANCES IN NNW-NW FLOW
AREAS OF THE CNTRL AND EASTERN CWA NEAR LK SUPERIOR INTO EARLY
FRIDAY BEFORE WINDS BECOME VARIABLE AND LOSE THEIR ONSHORE
COMPONENT. FLOW LOOKS DIFFLUENT IN LOW-LEVELS OVER THE WEST...SO
KEPT CONDITIONS DRY THERE. A BIT COOLER THAN THURSDAY WITH MAX TEMPS
MOST CWA IN THE 20S.
STRONGER SHORTWAVE AND SFC LOW PRESSURE SYSTEM DIG FM THE CANADIAN
PRAIRIES ON FRIDAY NIGHT ACROSS THE FAR NORTHERN REACHES OF THE UPR
GREAT LAKES REGION ON SATURDAY. TREND FOR THIS SYSTEM IS TO DIG
FARTHER SOUTH COMPARED TO WHAT WAS SHOWN A FEW DAYS AGO WHICH MAKES
SENSE AS THE SYSTEM WILL BE DIGGING INTO OVERALL LARGER SCALE TROUGH
ALOFT. CONSENSUS POINTS TO POPS OVER MAINLY THE NORTH...INFLUENCED
IN LARGE PART BY MOSTLY DRY GFS AND WETTER ECMWF. NUDGED CHANCE POPS
FARTHER SOUTH OVER UPR MICHIGAN DUE TO THE WETTER ECMWF SOLUTION.
PTYPE COULD BE ISSUE AS WARM AIR SURGES IN ONCE MOST PRECIP TRIES TO
END. GFS/ECMWF SOUNDINGS SHOW WARM LAYER ALOFT POKING INTO THE
SCNTRL. IF ENOUGH PRECIP IS AROUND WITH ARRIVAL OF WARM LAYER COULD
SEE MIXED PRECIP ISSUES OVER MAINLY THE CNTRL AND EAST. FOR NOW KEPT
PYTPE AS SNOW...ESPECIALLY SINCE THE TREND IS FARTHER SOUTH WHICH
WOULD DRAG COOLER AIR OVER CWA. TEMPS HAVE GOOD CHANCE OF REACHING
LOW 30S OVER MUCH OF CWA ON SATURDAY. THOUGH NOT SURE HOW WE GET
THERE IN REGARD TO SATURDAY SYSTEM DETAILS...DOES APPEAR TO TURN
COOLER SUNDAY INTO MONDAY BEHIND THE LOW PRESSURE SYSTEM. POPS FOR
NW FLOW AREAS FOR LES WERE RAMPED UP OVER CONSENSUS. NO OTHER
CHANGES MADE TO WINDS/TEMPS WITH SLIGHTLY COOLER CONDITIONS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1210 PM EST TUE JAN 13 2015
SUMMARY: GRADUALLY DETERIORATING CONDITIONS ARE EXPECTED THROUGH THE
TAF PERIOD AS A WEAK WEATHER SYSTEM MOVES NORTH OF THE GREAT LAKES
WITH LOWER CLOUDS AND LIGHT SNOW DEVELOPING.
RESTRICTIONS: VFR CONDITIONS ATTM. CLOUDS THICKEN AND LOWER
TONIGHT FROM WEST TO EAST WITH LIGHT SNOW/SHSN DEVELOPING AFTER
MIDNIGHT. THESE SHSN SHOULD HAVE NO PROBLEM GENERATING MVFR
RESTRICTIONS /DUE TO CIGS AND VSYBS/ WITH SOME BRIEF IFR VSBYS
POSSIBLE. WHILE VSBYS WILL IMPROVE BACK TO VFR WEDNESDAY
MORNING...EXPECT STRATUS TO CONTINUE TO LOWER...WITH MVFR/IFR CIGS
TO END THE TAF PERIOD.
WINDS: SOUTHWEST WINDS 12G20KTS ARE EXPECTED THROUGH THE AFTERNOON
AND INTO THE EVENING BEFORE DIMINISHING TO 10KTS THIS EVENING BEFORE
BACKING WESTERLY AND REMAINING NEAR 10KTS FOR THE MORNING WEDNESDAY.
LLWS: SOUTHWESTERLY WINDS AT 1.5KFT INCREASE TO 30-35KTS PROMOTING
THE DEVELOPMENT OF LLWS. WILL INCLUDE MENTION AT SAW/IWD WHERE
OVERNIGHT WINDS ARE WEAKEST. CMX LOOKS TO REMAIN WELL-ENOUGH MIXED
TO PRECLUDE LLWS MENTION HERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 446 AM EST TUE JAN 13 2015
ACTIVE LAST WEEK OF THE SHIPPING SEASON WITH STRONG WINDS AND SOME
HEAVY FREEZING SPRAY AT TIMES. SW GALES ALONG WITH HEAVY FREEZING
SPRAY IS EXPECTED THIS AFTN AND TONIGHT OVER WEST AND NCNTRL LK
SUPERIOR AHEAD OF A COLD FRONT THAT DROPS OVER THE AREA TONIGHT. GALE
WARNINGS AND HEAVY FREEZING SPRAY WARNINGS ARE IN EFFECT FOR THE
WESTERN HALF OF LK SUPERIOR. WINDS DIMINISH TO LESS THAN 20 KTS
BEHIND THE FRONT INTO WEDNESDAY. LULL IS BRIEF AS ANOTHER PERIOD OF
STRONG SW WINDS IS EXPECTED ON WED NIGHT TO THE SOUTH OF A DEEPENING
LOW PRESSURE SYSTEM OVER MANITOBA AND ONTARIO. AGAIN THE STRONGEST
WINDS WILL BE OVER WEST AND NCNTRL LK SUPERIOR. LOW WILL DEEPEN
FURTHER ON THURSDAY AS IT CROSSES JAMES BAY...RESULTING IN GOOD
CHANCE OF WESTERLY GALES 35-40 KTS OVER MUCH OF THE LAKE BY AFTN.
WINDS DIMINISH STEADILY THROUGH FRIDAY AS LOW MOVES FARTHER AWAY AND
NEW LOW PRESSURE NEARS FM THE NORTHERN PLAINS. WINDS SHOULD BECOME
SOUTH OR SOUTHEAST AHEAD OF THAT NEXT LOW. WINDS TO 30 KTS FRIDAY
NIGHT INTO SATURDAY OVER EASTERN LK SUPERIOR...THEN ALL AREAS BY
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LS...HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR
LSZ242>244-263-264.
SMALL CRAFT ADVISORY UNTIL 1 PM EST WEDNESDAY FOR LSZ242>244.
GALE WARNING UNTIL 5 AM EST WEDNESDAY FOR LSZ263-264.
LM...NONE.
&&
$$
UPDATE...ARNOTT/APX
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ARNOTT/APX
MARINE...JLA
AREA FORECAST DISCUSSION
NWS JACKSON MS
413 PM CST TUE JAN 13 2015
.DISCUSSION...
TONIGHT THROUGH THURSDAY...
THE PRIMARY FORECAST CONCERN FOR TONIGHT INTO WEDNESDAY IS THE
CONTINUED COLD ADVECTION PATTERN AND ASSOCIATED LOW STRATUS. A FEW
BREAKS ARE SHOWING UP ON LATEST SATELLITE IMAGERY OVER THE DELTA
REGION...BUT GUIDANCE INDICATES THAT THE STRATUS DECK WILL RE-
SOLIDIFY IN NNE LOW LEVEL FLOW AND PERSIST THROUGH TONIGHT FOR MOST
OF THE ARKLAMISS. HAVE TRENDED THE FORECAST MORE PESSIMISTIC AND
SIMILAR TO THE HRRR GUIDANCE WHICH HAS BEEN SUPERIOR TODAY TO THE
OPTIMISTIC SREF. IT DOES LOOK LIKE THE LOW LEVEL COLD ADVECTION
PATTERN WILL SHUT DOWN WEDNESDAY MORNING AND THIS SHOULD ALLOW FOR
CLEARING.
ATTENTION WILL THEN TURN TO THE SHORTWAVE TROUGH SHEARING EASTWARD
ACROSS THE SOUTHERN PLAINS. THIS LOW AMPLITUDE WAVE WILL CAUSE JUST
ENOUGH BACKING OF THE LOW/MID LEVEL FLOW AND WARM ADVECTION TO
GENERATE LIGHT TO MODERATE RAIN...MAINLY AFFECTING THE HIGHWAY 84
CORRIDOR. MODELS HAVE BEEN TRENDING A LITTLE MORE BULLISH WITH QPF
AND EVEN SUGGEST SOME QUARTER TO HALF INCH RAINFALL AMOUNTS WILL BE
POSSIBLE FROM WED NIGHT INTO THURSDAY IN THE HATTISBURG AREA. HAVE
INCREASED MODEL BLEND GUIDANCE POPS SOME BASED ON THESE TRENDS...AND
ITS POSSIBLE THE RAIN CHANCES WILL HAVE TO BE INCREASED SOME MORE AS
GET CLOSER IN TIME. GUIDANCE THERMAL PROFILES CONTINUE TO SUGGEST AN
ALL RAIN EVENT. /EC/
THURSDAY NIGHT THROUGH MONDAY...GENERALLY DRY CONDITIONS AND
SEASONABLE TEMPERATURES WILL PREVAIL THROUGH THE EXTENDED PORTION OF
THE FORECAST.
SURFACE HIGH PRESSURE WILL SET UP SHOP OVER THE EASTERN QUARTER OF
THE COUNTRY THROUGH THE WEEKEND WITH A WEAKENING SUBTROPICAL JET
REMAINING FAIRLY ZONAL OVERHEAD. THU NIGHT/FRI MORNING WILL LIKELY BE
THE COOLEST PERIOD THROUGH THE LONG TERM AS THE SURFACE RIDGE IS
EXPECTED TO BE DIRECTLY OVER THE AREA. EASTERN PORTIONS OF THE CWA
MAY EEK OUT A RATHER COLD FRI NIGHT AS WELL AS THE RIDGE AXIS LINGERS
OVER THOSE AREAS A BIT LATER. WEAK RETURN FLOW WILL COMMENCE ON
SATURDAY...WITH TEMPS TRENDING SLIGHTLY ABOVE NORMAL FROM THE LATE
WEEKEND INTO EARLY NEXT WEEK. A BIT OF MODEL DISAGREEMENT EMERGES AT
THE END OF THE FORECAST AS THE GFS DEVELOPS A DEEPER UPPER TROUGH
OVER THE ATLANTIC COAST SUNDAY INTO MONDAY. THIS WOULD BRING A BIGGER
PUSH OF DRIER AIR THAN SUGGESTED BY THE EURO...WHICH ESSENTIALLY
MAINTAINS SOUTHERLY LOW LEVEL FLOW INTO MONDAY. WILL COMPROMISE AND
SHOW LOW END POPS MAINLY OVER THE WEST ON MONDAY. /DL/
&&
.AVIATION...
AT MID AFTERNOON IFR TO MVFR CONDITIONS WAS NOTED ACROSS
MOST OF THE REGION. THE CLEARING LINE WAS STAYING NORTHWEST OF THE
REGION. FOR THIS AFTERNOON EXPECT CEILINGS MAINTAIN LIFR TO MVFR CONDITIONS
BEFORE GOING BACK TO LIFR CONDITIONS OVERNIGHT. EXPECT MVFR CEILINGS
EARLY WEDNESDAY./17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 30 47 34 48 / 5 4 22 16
MERIDIAN 31 49 35 48 / 6 3 16 21
VICKSBURG 29 44 34 48 / 5 4 22 14
HATTIESBURG 35 52 39 50 / 5 7 41 30
NATCHEZ 30 46 34 48 / 5 6 39 21
GREENVILLE 27 41 31 46 / 4 3 10 9
GREENWOOD 27 44 31 46 / 4 2 8 9
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
EC/DL/17/
AREA FORECAST DISCUSSION
NWS JACKSON MS
1037 AM CST TUE JAN 13 2015
.UPDATE...
THE FORECAST IS GENERALLY ON TRACK AND NO MAJOR ADJUSTMENTS WERE
NECESSARY IN THIS UPDATE. TEMPERATURES HAVE FALLEN BELOW FREEZING IN
NORTHERN PORTIONS OF THE DELTA REGION...BUT DRIZZLE HAS ENDED THERE
SO NOT SEEING ANY ISSUES WITH -FZDZ. THERE IS A NARROW BAND OF LIGHT
RAIN OVER CNTRL/SRN LA ASSOCIATED WITH A SHORTWAVE TROUGH CROSSING
THE LOWER MS VALLEY THIS MORNING. THIS IS CURRENTLY MOSTLY SOUTH OF
THE 31ST PARALLEL...BUT IT COULD DEVELOP NORTHWARD TOWARD THE
HIGHWAY 84 CORRIDOR AND BRING VERY LIGHT RAINFALL TO THE PINE BELT
REGION. OTHERWISE...STRATUS MAY BE A LITTLE MORE STUBBORN TO CLEAR
OUT LOOKING AT THE LAST TRENDS WITH CONTINUED NNE FLOW/COLD
ADVECTION. THE LATEST HRRR KEEPS IT SOLIDLY OVER THE ENTIRE AREA THIS
AFTERNOON AND HAVE SLOWED CLEARING SOME. HAVE MADE MINOR ADJUSTMENTS
TO TEMPERATURES AS WELL. /EC/
&&
.PREV DISCUSSION... /ISSUED 355 AM CST TUE JAN 13 2015/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...MODIFIED ARCTIC AIR
WILL BE TRYING TO SLIDE SOUTH INTO THE LOWER MS VALLEY THROUGH THE
SHORT TERM PERIOD...BUT FORTUNATELY THE BRUNT OF THE COLD AIR WILL
SLIDE BY WELL TO OUR NORTH. STILL...RECEIVING A PERCENTAGE OF THE
COLD IN JUXTAPOSITION WITH LOTS OF CLOUD COVER WILL KEEP CONDITIONS
FAR FROM PLEASANT THROUGH WEDNESDAY NIGHT.
THE WORST OF THE SHORT TERM SHOULD BE TODAY. MODERATE COLD AIR
ADVECTION EARLY THIS MORNING WILL PERSIST INTO THE
AFTERNOON...HELPING TO DRIVE LOW CLOUDS AND PATCHY DRIZZLE UNTIL AT
LEAST MIDDAY. SURFACE TEMPERATURES MAY CONTINUE TO DROP SEVERAL
HOURS PAST SUNRISE AND FOR HIGHS I SIDED WITH THE LOW SIDE OF
OVERALL GUIDANCE BLENDS...ESPECIALLY CONSIDERING THAT SUN WILL BE
HARD TO COME BY EVEN INTO THE AFTERNOON HOURS.
LOW CLOUDS WILL TRY TO AT LEAST PARTIALLY CLEAR TONIGHT AS DRY
ADVECTION STARTS TO WIN OUT OVER COLD ADVECTION...ALTHOUGH AT LEAST
PATCHY LATE NIGHT LOW CLOUDS COULD REFORM ALONG AND SOUTHEAST OF THE
NATCHEZ TRACE CORRIDOR. THESE PATCHY CLOUDS SHOULD HOLD UP LOWS TO
NEAR OR SLIGHT BELOW FREEZING IN THESE LATTER AREAS WHILE ELSEWHERE
MINIMUMS IN THE UPPER 20S ARE MORE LIKELY.
PHASING...YET DAMPENING...SOUTHERN AND NORTHERN STREAM UPPER AIR
DISTURBANCES WILL BE APPROACHING BY LATER WEDNESDAY INTO WEDNESDAY
NIGHT...INCREASING CLOUD COVER AGAIN. TEMPERATURES WILL REMAIN
SEASONABLY CHILLY AS A MODERATE TO LIGHT PRECIPITATION SHIELD
FOCUSED MAINLY ALONG AND SOUTH OF THE COAST SPREADS ITS UPPER
FRINGES POSSIBLY AS FAR NORTH AS THE I-20 CORRIDOR BY THURSDAY
EVENING. THE OFFICIAL FORECAST HAS SOME TEMPERATURES NOT TOO FAR
ABOVE FREEZING IN AREAS OF LOW RAIN CHANCES...BUT IN ACTUALITY IF IT
DOES RAIN THEN TEMPERATURES WILL LIKELY VERIFY A FEW DEGREES WARMER.
SO...IN SHORT...POTENTIAL FOR WINTER WEATHER IN THE REGION OVER THIS
PERIOD IS LOOKING PRETTY LOW AND NOTHING IS REQUIRED IN THE HWO AT
THIS JUNCTURE. /BB/
LONG TERM...THURSDAY THROUGH MONDAY...GENERALLY DRY CONDITIONS AND
SEASONABLE TEMPERATURES WILL PREVAIL THROUGH THE EXTENDED PORTION OF
THE FORECAST.
AT THE BEGINNING OF THE PERIOD A SURFACE LOW WILL TRACK EASTWARD
ACROSS THE CENTRAL GULF AS A MIDLEVEL SHORTWAVE PASSES ACROSS THE
DEEP SOUTH AND A ZONAL UPPER JET IS POSITIONED OVER THE AREA. THOUGH
THE LOW WILL BE DISPLACED SOUTH OF THE COAST...AREAS OF MAINLY LIGHT
RAIN OR DRIZZLE WILL BE POSSIBLE OVER THE SOUTHERN PORTION OF THE
CWA INTO THURSDAY MORNING. A REINFORCING SHOT OF COOLER AND DRIER
AIR WILL MOVE INTO THE REGION DURING THE AFTERNOON/EVENING...ENDING
MEASURABLE PRECIP POTENTIAL.
SURFACE HIGH PRESSURE WILL SET UP SHOP OVER THE EASTERN QUARTER OF
THE COUNTRY THROUGH THE WEEKEND WITH A WEAKENING SUBTROPICAL JET
REMAINING FAIRLY ZONAL OVERHEAD. THU NIGHT/FRI MORNING WILL LIKELY
BE THE COOLEST PERIOD THROUGH THE LONG TERM AS THE SURFACE RIDGE IS
EXPECTED TO BE DIRECTLY OVER THE AREA. EASTERN PORTIONS OF THE CWA
MAY EEK OUT A RATHER COLD FRI NIGHT AS WELL AS THE RIDGE AXIS
LINGERS OVER THOSE AREAS A BIT LATER. WEAK RETURN FLOW WILL COMMENCE
ON SATURDAY...WITH TEMPS TRENDING SLIGHTLY ABOVE NORMAL FROM THE
LATE WEEKEND INTO EARLY NEXT WEEK. A BIT OF MODEL DISAGREEMENT
EMERGES AT THE END OF THE FORECAST AS THE GFS DEVELOPS A DEEPER
UPPER TROUGH OVER THE ATLANTIC COAST SUNDAY INTO MONDAY. THIS WOULD
BRING A BIGGER PUSH OF DRIER AIR THAN SUGGESTED BY THE EURO...WHICH
ESSENTIALLY MAINTAINS SOUTHERLY LOW LEVEL FLOW INTO MONDAY. WILL
COMPROMISE AND SHOW LOW END POPS MAINLY OVER THE WEST ON MONDAY. /DL/
&&
.AVIATION...AS OF LATE MORNING LIFR TO IFR CONDITIONS WERE NOTED
ACROSS MOST OF THE REGION WITH SOME MVFR CONDITIONS IN THE NORTH.
THE CLEARING LINE WAS APPROACHING THE NORTHWEST DELTA REGION FROM
ARKANSAS. FOR THIS AFTERNOON EXPECT CEILINGS TO SLOWLY IMPROVE TO
MVFR CONDITIONS THROUGH THE AFTERNOON INTO THE EARLY EVENING FROM THE
NORTHWEST TO THE SOUTHEAST. CEILINGS WILL DIP TO LIFR CONDITIONS
DURING THE NIGHT BEFORE GOING BACK TO MVFR CONDITIONS...EXCEPT FOR
THE NORTHWEST DELTA REGION...WHICH WILL BECOME VFR THIS EVENING./17/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
PREVIOUS FORECAST DISCUSSION.... TONIGHT AND WEDNESDAY: AS THE
AFOREMENTIONED SURFACE HIGH BUILDS INTO A VERY FAVORABLE LOCATION
(ACROSS THE NORTHEAST U.S.) TO DELIVER CONTINUED COLD DRY AIR INTO
THE REGION WE WILL SEE PRECIP CHANCES INCREASE.... WITH LOCATIONS
GENERALLY ALONG AN EAST OF A LINE FROM ROXBORO TO SILER CITY AND
WADESBORO SEEING AT LEAST A GOOD TENTH TO A QUARTER OF AN INCH OF
PRECIP (LIQUID EQ). GIVEN THE STRENGTH OF THE HIGH TO THE NORTH...
COUPLED WITH AN APPROACHING DISTURBANCE EXPECT WE WILL SEE PRECIP
BLOSSOM OVER THE AREA (ESPECIALLY SOUTHERN AND EASTERN PORTIONS OF
CENTRAL NC)... INITIALLY AS RAIN AND POSSIBLY SLEET... THEN QUICKLY
TRANSITING TO FREEZING RAIN OR A MIXTURE OF FREEZING RAIN AND SLEET
AS WETBULB TEMPS ARE EXPECTED TO FALL TO BELOW FREEZING AREAWIDE BY
06Z WEDNESDAY OR SO... AND AS EARLY AS 00Z ACROSS THE NORTH HALF OF
THE AREA. MODELS HAVE TRENDED WETTER FOR THIS PERIOD... WHICH
PROMPTED THE EVENING SHIFT TO ISSUE A WINTER STORM WATCH FOR EASTERN
PORTIONS OF CENTRAL NC GIVEN THE FAVORABLE SETUP FOR A POSSIBLE
SIGNIFICANT FREEZING RAIN EVENT AS CONTINUED DRY AIR WILL HELP
OFFSET THE RELEASE OF LATENT HEAT FROM PHASE CHANGE. FOR NOW WE PLAN
TO KEEP THE WINTER STORM WATCH AS IS... AND ISSUE A WINTER WEATHER
ADVISORY FOR THE REMAINDER OF CENTRAL NC. EXPECT ICE ACCRUAL AMOUNTS
WILL RANGE FROM A FEW HUNDREDTHS OR A TRACE IN THE NORTHWEST
PIEDMONT TO AS MUCH AS A QUARTER OF AN INCH IN THE WATCH AREA. WHILE
A TRACE TO A COUPLE OF HUNDREDTHS DO NOT SEEM LIKE THAT MUCH IN THE
TRIAD TEMPS WILL FALL INTO THE MID TO UPPER 20S TUESDAY NIGHT/EARLY
WEDNESDAY MORNING... ALLOWING FOR SLICK SPOTS TO DEVELOP ON AREA
ROADS... SIDEWALKS... AND BRIDGES. WRT THE WATCH AREA.... WE WILL
CONTINUE TO MONITOR HOW MODELS ARE HANDLING THE S/W DISTURBANCE
ACROSS THE DEEP SOUTH AS IT APPROACHES OUR REGION. WE HAVE A HIGH
DEGREE OF CONFIDENCE THAT AT LEAST AN ADVISORY WILL BE NECESSARY.
HOWEVER... A WINTER STORM WARNING MAYBE NEED FOR FREEZING RAIN FOR
PORTIONS OF THE WATCH AREA LATER TODAY. THUS... WILL KEEP THE WATCH
OUT FOR NOW. LOW TEMPS TONIGHT AREA EXPECTED TO BE IN THE MID TO
UPPER 20S TO NEAR 30 ACROSS THE FAR SOUTH.
THE S/W DISTURBANCE SHOULD BEGIN TO SHIFT TO THE EAST OF THE AREA
SHORTLY AFTER 12Z ON WEDNESDAY. HOWEVER... THE CAD AIRMASS WILL
REMAIN LOCKED IN PLACE AND RESULT IN A SLOW WARM UP ON WEDNESDAY AND
CLOUDY SKIES WITH POCKETS OF LINGERING DRIZZLE/FREEZING DRIZZLE.
EXPECT TEMPS SHOULD GENERALLY REACH ABOVE FREEZING BY EARLY
AFTERNOON (LAST ACROSS THE NORTHEAST PIEDMONT AND NORTHERN COASTAL
PLAIN). HIGHS WEDNESDAY ARE EXPECTED TO BE IN THE LOWER TO MID
30S... WITH A FEW SPOTS ACROSS THE SOUTHWEST REACHING THE UPPER 30S.
-BSD
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 215 PM TUESDAY...
OTHER THAN SOME VERY LIGHT DRIZZLE IN THE EXTREME NORTHEASTERN
PORTION OF THE CWA...PRECIPITATION WILL HAVE COME TO AN END BY 00Z
WEDNESDAY NIGHT BEGINNING WHAT NOW APPEARS TO BE A DRIER PERIOD FOR
WEDNESDAY NIGHT AND THURSDAY. SYNOPTICALLY A LONG WAVE UPPER TROUGH
OVER THE EASTERN CONUS WILL BEGIN TO DIG OVER THE AREA WITH THE AXIS
OVER THE CAROLINAS BY 6Z FRIDAY. UNTIL THEN...THE CWA WILL BE ON THE
WARM SIDE OF THE TROUGH WITH SOUTHWESTERLY FLOW ALOFT. AT THE
SURFACE HOWEVER THE FLOW WILL REMAIN INITIALLY NORTHEASTERLY...THEN
CALMING AND BACKING TO NORTHWESTERLY LATER IN THE PERIOD. THIS WILL
KEEP TEMPERATURES BELOW NORMAL WITH MINIMUM TEMPS IN THE UPPER 20S
TO LOW 30S WEDNESDAY NIGHT...FOLLOWED BY HIGHS IN THE MIDDLE 40S ON
THURSDAY.
A LITTLE UNCERTAINTY IN THE FORECAST FOR THURSDAY NIGHT AS ANOTHER
SHORTWAVE SYSTEM ORIGINATING FROM THE GULF OF MEXICO APPROACHES THE
AREA BUT MODELS ARE SPLIT ON WHETHER OR NOT PRECIPIATION MAKES IT
FAR ENOUGH NORTH TO ENCROACH ON THE SOUTHERN TIER OF OUR AREA.
REGARDLESS OF IF IT DOES OR NOT...PRECIPIATION WILL REMAIN ALL
LIQUID WITH FAIRLY LIGHT QPF AMOUNTS AT THIS TIME AS RAIN. LOWS IN
THE UPPER 20S TO LOW 30S NW TO SE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...
A GRADUAL WARMUP COMMENCES FROM LATE WEEK INTO THE WEEKEND AS THE
UPPER TROF PATTERN TRANSITIONS TO LOW AMPLITUDE RIDGING FRIDAY INTO
SUNDAY. HIGHS FRIDAY AND SATURDAY WILL EDGE SLIGHTLY ABOVE NORMAL AS
HEIGHTS BUILD...IN THE LOW TO MID 50S AFTER MORNING LOWS MOSTLY IN
THE UPPER 20S. OUR HIGH TEMPS WILL MAX OUT ON SUNDAY AS THE
ASSOCIATED SURFACE HIGH PRESSURE PROGRESSES SMOOTHLY ACROSS THE AREA
AND OFFSHORE...WITH ENSUING RETURN FLOW NUDGING HIGHS TO 55 TO
60...ABOUT 8 DEGREES ABOVE NORMAL.
AN UPPER SHORT WAVE SKIRTING THE GREAT LAKES WELL NORTH OF THE AREA
WILL BE REFLECTED AT THE SURFACE IN THE FORM OF A WEAK AND DRY COLD
FRONT WHICH WILL PUSH SOME MILDLY COOLER TEMPERATURES INTO THE MID
ATLANTIC SUNDAY NIGHT. HIGHS MONDAY AND TUESDAY WILL STILL REACH 3-5
DEGREES ABOVE NORMAL...THE LOW TO MID 50S...AFTER MORNING LOWS
AROUND FREEZING.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 120 PM TUESDAY...
24 HOUR TAF PERIOD: VERY HIGH CONFIDENCE OF SUB VFR CONDITIONS FOR
MUCH IF NOT ALL OF THE TAF PERIOD. THERE IS ALSO A CHANCE THAT SOME
IF NOT ALL TAF SITES WILL SEE SOME FREEZING RAIN AFTER 3Z THROUGH
ABOUT 12Z WEDNESDAY.
FOR THE REST OF THE AFTERNOON ANY PRECIPITATION WILL BE LIGHT AND
MAINLY AT CENTRAL AND EASTERN TAF SITES. MVFR CEILINGS WILL
DOMINATE THE OBSERVATIONS THROUGH MUCH OF THE PERIOD WITH SOME
SPORADIC VFR AND IFR TEMPOS. VISIBILITIES WILL LARGELY STAY VFR BUT
SOME DECLINE TO AT LEAST MVFR LEVELS ARE EXPECTED TONIGHT. IN
ADDITION TO THE MVFR CONDITIONS THERE WILL BE SOME GUSTY WINDS THIS
AFTERNOON...AND THROUGH MUCH OF THE NIGHT AS WELL. WIND WILL BE
GENERALLY NORTHEASTERLY AT 10-15 KTS GUSTING TO 20-25 KTS IN SOME
SPOTS.
MOVING INTO TONIGHT...TEMPERATURES WILL DROP BELOW FREEZING AND THE
CHANCE FOR FREEZING RAIN WILL INCREASE AFTER 3Z OR SO FOR NORTHERN
SITES AND AFTER 6Z FOR SOUTHERN SITES. ACCUMULATIONS ARE ONLY
EXPECTED TO BE A COUPLE HUNDREDTHS OF AN INCH BUT KRDU AND KRWI
COULD SEE ONE TO TWO TENTHS OF AN INCH. THIS WOULD BE THE HIGHEST
ACCUMULATIONS AND THEN A FEW HUNDREDTHS OF AN INCH FOR KFAY AS WELL.
IMPACTS FROM FREEZING RAIN WILL LAST THROUGH ABOUT 12Z BEFORE
TAPERING OFF. WINDS WILL ALSO START TO DECREASE IN SPEED INTO
WEDNESDAY AFTERNOON BUT CEILINGS ARE STILL EXPECTED TO REMAIN MVFR
THROUGH THE END OF THE 18Z TAF PERIOD.
OUTLOOK: ANOTHER SYSTEM MOVING UP THE COAST WILL KEEP WEATHER
UNSETTLED THROUGH THURSDAY NIGHT INTO FRIDAY BUT PRECIPIATION WITH
THIS LOW SHOULD BE ALL LIQUID. SOME PATCHY FOG AND PERIODS OF
PRECIPIATION WILL POTENTIALLY CAUSE SOME SUB-VFR CONDITIONS. HIGH
PRESSURE WILL HELP VFR CONDITIONS TO RETURN FOR THE WEEKEND AND
EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH WEDNESDAY
MORNING FOR NCZ008>011-025>028-041>043-077-078-086-088-089.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO NOON EST WEDNESDAY
FOR NCZ007-021>024-038>040-073>076-083>085.
&&
$$
SYNOPSIS...WSS
NEAR TERM...BLAES/BSD
SHORT TERM...ELLIS
LONG TERM...MLM
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
251 PM CST TUE JAN 13 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 251 PM CST TUE JAN 13 2015
MAIN CHALLENGE TONIGHT WILL BE CLOUD TRENDS/TEMPS AND FLURRY OR
LIGHT SNOW CHANCES ACROSS THE FAR SOUTH/SE. LOOKING AT CURRENT
CONDITIONS IT IS CLEARING OFF ACROSS THE FAR WESTERN FA. THE
THICKER CLOUDS HAVE MOVED INTO THE RED RIVER VALLEY AND POINTS TO
THE EAST. THE CLOUDS WILL CONTINUE TO MOVE OFF TO THE EAST THIS
EVENING. ANOTHER BAND OF LOW CLOUDS OVER WESTERN ND IS SINKING
SOUTH AND THINK THAT TREND WILL ALSO CONTINUE. THEREFORE MOST OF
THE FA SHOULD STAY CLEAR UNTIL CLOUDS ASSOCIATED WITH THE NEXT
CLIPPER START TO MOVE INTO THE NORTHWEST FA LATE. TEMPS COULD TAKE
A BIT OF A ROLLER COASTER RIDE...DROPPING ONCE THE CLOUDS MOVE OUT
THIS EVENING AND THEN RISE SOME LATE AS THE NEXT BATCH OF CLOUDS
MOVES IN. ALL SAID...TRICKY...ESPECIALLY SINCE GUIDANCE TEMPS HAVE
BEEN SO BAD LATELY. WATER VAPOR IMAGERY SHOWS A LITTLE BETTER WAVE
MOVING ACROSS CENTRAL/EASTERN CENTRAL SD...WHERE THE REGIONAL
RADARS SHOW A FEW STRONGER ECHOES. SOME OF THE WEAKER ECHOES ARE
TRYING TO MAKE IT UP INTO THE FAR SOUTHERN FA BUT NOTHING IS BEING
REPORTED AT THE SFC YET. WILL LEAVE THE LOW LIGHT SNOW CHANCES
ACROSS THE FAR SOUTH/SE EARLY THIS EVENING TO COVER THIS. NEXT
CLIPPER SYSTEM WILL TRACK INTO THE NORTHERN/NE FA WED/WED EVENING
AND WILL SPREAD A DUSTING TO MAYBE AN INCH OF SNOW TO AREAS ALONG
THE CANADIAN BORDER OVER TOWARD THE LAKE OF THE WOODS REGION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 251 PM CST TUE JAN 13 2015
SFC HIGH DROPS FROM NORTH OF THE MANITOBA LAKES REGION BY 00Z FRI
INTO SW ONTARIO BY 12Z FRI. SEVERAL MODEL SOLUTIONS TRY TO BREAK
OUT SOME LIGHT PCPN ON THE WESTERN PERIPHERY OF THIS...OR OVER
CENTRAL AND EASTERN ND. HAVE IGNORED THIS FOR NOW AND WILL SEE
WHAT LATER SOLUTIONS BRING. NEXT CLIPPER WILL BEGIN TO AFFECT THE
NORTHERN FA BY FRI AFTERNOON...BASICALLY GIVING THE NORTHERN
VALLEY TOWARD THE LAKE OF THE WOODS AREA ANOTHER DUSTING OF LIGHT
SNOW.
FRIDAY NIGHT THROUGH TUESDAY...FLOW WILL CONTINUE TO BE WESTERLY OR
NORTHWESTERLY...WITH THE TIMING OF VARIOUS SHORTWAVES MOVING THROUGH
THE MAIN CHALLENGE. THERE IS GOOD AGREEMENT ON THE FIRST SHORTWAVE
COMING THROUGH FRIDAY NIGH AND SATURDAY...WITH ALL MODELS TAKING THE
SFC LOW JUST NORTH OF THE CANADIAN BORDER WITH COLD AIR AND SOME
LIGHT WRAP AROUND PRECIP COMING IN BEHIND IT. SUNDAY THE ECMWF HAS
ANOTHER SHORTWAVE COMING THROUGH WHILE THE GFS AND GEM ARE DRY. WITH
THE HIGH AMOUNT OF SPREAD...WILL KEEP THE BLENDED SOLUTION AS A BEST
GUESS FOR TIMING. TEMPS WILL COME DOWN A BIT ON SATURDAY NIGHT AND
SUNDAY BUT RECOVER QUICKLY AS EVEN WITH COLD AIR ADVECTION THE TRUE
ARCTIC AIR IS NOT TAPPED. OVERALL TEMPS SHOULD BE ABOVE AVERAGE FOR
THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM CST TUE JAN 13 2015
SAT LOOP AND SFC OBS SHOW SOME VFR CLOUDS WITH CIGS AROUND 6000 FT
MOVING INTO OUR SOUTHWESTERN FORECAST AREA AND SHOULD IMPACT THE
KFAR AREA IN THE NEXT HOUR OR SO. SOUTH WINDS CONTINUE TO BE RATHER
BREEZY WITH SOME GUSTS OVER 25 KTS AT TIMES. THINK THAT WINDS WILL
BEGIN TO GO DOWN TOWARDS THE END OF THE AFTERNOON AS THE SFC TROUGH
OVER CENTRAL ND MOVES EAST. OVER EASTERN MT THERE ARE SOME MVFR AND
IFR CIGS JUST BEHIND THE TROUGH AXIS...AND THE RAP SHOWS THIS LOWER
LEVEL MOISTURE MOVING IN LATER THIS EVENING. INCLUDED A MVFR MENTION
AT ALL BUT KFAR AS THERE WILL BE SOME PERIOD OVERNIGHT WITH CIGS. DO
NOT THINK IT WILL BE LONG LASTING AS THERE SHOULD BE SOME DRIER AIR
MOVING IN BY THE END OF THE PERIOD. WINDS WILL WEAKEN AND SHIFT WEST
AND THEN BACK TO THE SOUTH BY WEDNESDAY MORNING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...GODON
LONG TERM...GODON/JR
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1249 PM CST TUE JAN 13 2015
.UPDATE...
ISSUED AT 1249 PM CST TUE JAN 13 2015
FINGER OF CLOUDS THAT WAS APPROACHING THE SW FA DURING THE LAST
UPDATE IS NOW EXTENDING UP AND DOWN THE RED RIVER VALLEY. LOOKS
LIKE THEY SHOULD CONTINUE PROGRESSING EAST THRU THE AFTERNOON.
THESE ARE ASSOCIATED WITH 850MB WARM ADVECTION AND ARE ALSO
HELPING TO BOOST SFC TEMPS BACK ABOVE ZERO. LOOKS LIKE THERE
SHOULD BE DECREASING CLOUDS IN THEIR WAKE BY MID TO LATE
AFTERNOON. AS FAR AS PCPN CHANCES...REGIONAL RADAR LOOP SHOWS
ECHOES OVER EASTERN SD...SOME AS FAR NORTH AS KABR. HOWEVER
NOTHING WAS REPORTED AT KABR AS THEY MOVED THRU. LIGHT SNOW IS
BEING REPORTED AT KPIR AND KHON IN EAST CENTRAL SD. NOT SURE HOW
FAR NORTH THIS LITTLE AREA OF LIGHT SNOW WILL GET...BUT NOT VERY
CONFIDENT AT THIS POINT. LATEST HIGH RESOLUTION MODELS KEEP
ANYTHING SOUTH OF THE FA. 12Z GFS/ECMWF STILL SHOW SOME MINIMAL
QPF ACROSS THE FAR SE SO WILL DECREASE PCPN CHANCES A LITTLE BUT
KEEP THEM WHERE THEY WERE. MAY BE MORE OF A FLURRY EVENT THAN
ANYTHING.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 338 AM CST TUE JAN 13 2015
WIND CHILL ADVISORY EXPIRATION TIME OF 10AM LOOKS GOOD.
MODELS ARE IN DECENT AGREEMENT. A PARADE OF UPPER WAVES WITHIN THE
NORTHERN STREAM STORM TRACK WILL PASS JUST NORTH OF THE REGION
THIS PERIOD. ANTICIPATE LOW LEVEL SOUTHERLY FLOW (WARM AIR
ADVECTION) AHEAD OF EACH UPPER WAVE...AND NORTHERLY LOW LEVEL
(COLD AIR ADVECTION) FLOW BEHIND EACH UPPER WAVE. TIMING OF THESE
WAVES WILL AFFECT MAX/MIN TEMPERATURE VALUES...BUT OVERALL MUCH
WARMER THAN PREVIOUS DAYS.
STRONGEST SIGNALS FOR -SN ARE THIS AFTERNOON ACROSS WC MN...AND
WED AFTERNOON ACROSS THE NORTHERN FA. KEPT CHANCES BELOW LIKELY
CATEGORY UNTIL MORE CONFIDENCE CAN BE OBTAINED. THESE -SN CHANCES
SHOULD PRODUCE LESS THAN AN INCH OF SNOW ANYWAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 AM CST TUE JAN 13 2015
WEDNESDAY NIGHT-THURSDAY NIGHT...THE PATTERN FROM THE SHORT TERM
PERIOD CONTINUES. THERE ARE NOT YET ANY STRONG SIGNALS FOR PRECIP
THIS PERIOD.
FRIDAY-MONDAY...MODELS REMAIN FAIRLY CONSISTENT WITH THE ABOVE
NORMAL TEMP REGIME INTO THE WEEKEND AND EARLY NEXT WEEK. IT REMAINS
TO BE SEEN HOW MUCH ABOVE NORMAL. THE EC CONTINUES TO BE COOLER THAN
THE GEM AND GFS WITH WRT THE COLD INTRUSIONS ON THE BACK SIDE OF
THE WEAK SYSTEMS MOVING ACROSS ALONG THE WNW FLOW ALOFT. WILL
CONTINUE THE ONGOING SLIGHT POPS ALONG THE INTERNATIONAL BORDER WITH
THE FIRST WAVE SATURDAY MORNING AND WITH ANOTHER ON SUNDAY. MAX
TEMPS FOR THE PERIOD IN THE 20S AND 30S...WELL ABOVE THE MID JANUARY
NORMALS OF LOW TO MID TEENS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM CST TUE JAN 13 2015
SAT LOOP AND SFC OBS SHOW SOME VFR CLOUDS WITH CIGS AROUND 6000 FT
MOVING INTO OUR SOUTHWESTERN FORECAST AREA AND SHOULD IMPACT THE
KFAR AREA IN THE NEXT HOUR OR SO. SOUTH WINDS CONTINUE TO BE RATHER
BREEZY WITH SOME GUSTS OVER 25 KTS AT TIMES. THINK THAT WINDS WILL
BEGIN TO GO DOWN TOWARDS THE END OF THE AFTERNOON AS THE SFC TROUGH
OVER CENTRAL ND MOVES EAST. OVER EASTERN MT THERE ARE SOME MVFR AND
IFR CIGS JUST BEHIND THE TROUGH AXIS...AND THE RAP SHOWS THIS LOWER
LEVEL MOISTURE MOVING IN LATER THIS EVENING. INCLUDED A MVFR MENTION
AT ALL BUT KFAR AS THERE WILL BE SOME PERIOD OVERNIGHT WITH CIGS. DO
NOT THINK IT WILL BE LONG LASTING AS THERE SHOULD BE SOME DRIER AIR
MOVING IN BY THE END OF THE PERIOD. WINDS WILL WEAKEN AND SHIFT WEST
AND THEN BACK TO THE SOUTH BY WEDNESDAY MORNING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...GODON
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1225 PM CST TUE JAN 13 2015
.UPDATE...
ISSUED AT 1225 PM CST TUE JAN 13 2015
LATEST 17 UTC RAP CONTINUES TO SHOW A BAND OF MVFR-IFR CLOUDS
MOVING SOUTHEAST ACROSS THE FORECAST AREA. PATCHY FOG AND FLURRIES
REPORTED FROM BEACH TO WILLISTON SO WILL ADD A MENTION TO THE WEST
THIS AFTERNOON. WILL REVISIT WITH THE AFTERNOON PACKAGE TO SEE IF
WE NEED TO EXTEND THIS INTO THE CENTRAL LATE AFTERNOON/EVENING.
ACCUMULATIONS...IF ANY WILL BE NEGLIGIBLE. UPDATED SKY COVER BASED
ON CURRENT SATELLITE IMAGERY AND RAP GUIDANCE PROGRESSING THE LOW
LEVEL MOISTURE EASTWARD ACROSS THE FORECAST AREA. TEMPERATURES
LOOK REASONABLE SO NO ADJUSTMENTS HERE.
UPDATE ISSUED AT 955 AM CST TUE JAN 13 2015
WILL CANCEL/EXPIRE THE WIND CHILL ADVISORY FOR THE FAR EASTERN
COUNTIES. OTHERWISE THE MAIN ISSUE IS A BAND OF IFR TO MVFR
CEILINGS MOVING INTO WESTERN NORTH DAKOTA. HAVE SLOWED THE
PROGRESSION OF THE CLOUDS INTO NORTH DAKOTA AND CUT BACK ON CLOUD
AMOUNT AS NOTED BY LATEST HRRR.
UPDATE ISSUED AT 622 AM CST TUE JAN 13 2015
WILL TRIM THE WIND CHILL ADVISORY ACROSS THE CENTRAL SECTIONS
WHERE CHILLS HAVE RISEN WELL ABOVE CRITERIA. WILL LEAVE EASTERN N
SECTIONS GOING THROUGH 15Z. COMPLICATED STRATUS FIELD FORMING IN
RESPONSE TO LOW LEVEL WARM ADVECTION ACROSS SOUTH DAKOTA INTO
SOUTH CENTRAL NORTH DAKOTA. THEN COLD FRONTAL STRATUS WILL MOVE
INTO THE WEST LATER TODAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 204 AM CST TUE JAN 13 2015
MAIN CONCERNS IN THE SHORT TERM INCLUDE THE CURRENT WIND CHILL
ADVISORY HEADLINE...CLOUDS...AND POSSIBLE LIGHT PRECIPITATION
APPROACHING THE FAR NORTH LATE TUESDAY NIGHT.
FOR TUESDAY...THE CURRENT FOG/STRATUS IMAGERY LOOP SHOWS A CLEAR
SKY OVER WESTERN AND CENTRAL NORTH DAKOTA. HOWEVER...CLOUDS IN
WESTERN/CENTRAL SOUTH DAKOTA ARE RAPIDLY APPROACHING ADAMS AND SIOUX
COUNTIES. THIS IS PICKED UP BY THE HRRR AND IS FORECAST TO MOVE
INTO FAR SOUTH CENTRAL NORTH DAKOTA AND THEN ACROSS THE SOUTHERN
JAMES RIVER VALLEY THROUGH 18Z. WITH CLOUDS FORECAST TO SLIDE
ACROSS FAR SOUTH CENTRAL EARLY THIS MORNING...A PORTION OF THE
ONGOING WIND CHILL ADVISORY WILL NEED TO BE MONITORED CLOSELY FOR
A POSSIBLE EARLY CANCELLATION PRIOR TO 16Z. OTHERWISE THE REST OF
THE WIND CHILL ADVISORY AREA LOOKS IN GOOD SHAPE THROUGH 16Z.
ANOTHER AREA OF CLOUDS LOCATED IN EASTERN MONTANA IS ALSO GETTING
CLOSER TO THE WESTERN BORDER...NEAR BEACH. SO FAR CEILINGS WITH
BOTH THE SOUTH DAKOTA AND MONTANA CLOUDS ARE AROUND 5000FT...WITH
THE TRUE STRATUS DECK FILTERING IN ACROSS SOUTHWEST SASKATCHEWAN.
WITH THAT SAID...THE LATEST WATER VAPOR IMAGERY SHOWS OUR NEXT
PAIR OF SHORTWAVE TROUGHS THAT WILL AFFECT NORTH DAKOTA. THE FIRST
WAS SLIDING THROUGH SOUTH CENTRAL SASKATCHEWAN...AND THE SECOND
WAS OVER NORTHEAST MONTANA. UNDERNEATH WAS THE REFLECTION OF A
WEAK SURFACE COLD FRONT WITH A COLD POCKET OF AIR/-4C TO -6C
REFLECTED AT 850MB. THE STRATUS PER HRRR MODEL WILL ARRIVE IN
NORTHWEST NORTH DAKOTA BETWEEN 16Z-18Z AND THEN CONTINUE INTO
CENTRAL NORTH DAKOTA BY MID AFTERNOON/EARLY EVENING. HAVE UTILIZED
A BLEND OF THE HRRR/RAP13 FOR SKY GRIDS TODAY...AND THE NAM FOR
LATE THIS AFTERNOON THROUGH TONIGHT ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. WINDS WILL SHIFT TO THE WEST/NORTHWEST WITH THE
FRONTAL PASSAGE...FOLLOWED BY THE STRATUS DECK A FEW HOURS LATER.
FOR TUESDAY NIGHT...WARM AIR ADVECTION QUICKLY RE-ESTABLISHES
ITSELF...ESPECIALLY ACROSS THE NORTH AS A WARM FRONTAL SYSTEM
SLIDES THROUGH SASKATCHEWAN. THE STRONGEST VERTICAL MOTION/OMEGA
FIELD REMAINS IN CENTRAL/EASTERN SASKATCHEWAN AND INTO WESTERN
MANITOBA FROM 06Z- 12Z WEDNESDAY. THE NAM/GFS HOLD THE
PRECIPITATION THREAT NORTH OF THE BORDER THROUGH 12Z WEDS. THE
ECMWF AND GEM ARE SLIGHTLY FASTER AND FARTHER WEST. THE GEM
PRODUCES SOME LIGHT PRECIPITATION FROM CROSBY TO AROUND SHERWOOD
BY 12Z WEDNESDAY. WITH THE SREF SHOWING THE PRECIPITATION ALSO
NORTH OF THE BORDER...HAVE PAINTED IN 14 POPS ALONG THE BORDER
TOWARD 12Z WEDS...AS THE SHORT TERM PERIOD COMES TO AN END. NOT
EXPECTING ANY WIND CHILL HEADLINES TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 204 AM CST TUE JAN 13 2015
THE EXTENDED PERIOD CONTINUES TO DISPLAY A GOOD WARMING TREND AS
MID LEVEL FLOWS STRENGTHEN AND GRADUALLY BACK FROM A NORTHWEST TO
A WESTERLY FLOW. THIS WILL BRING MODIFIED PACIFIC AIR INTO THE
NORTHERN PLAINS BEGINNING WEDNESDAY. AS THE WARMER AIR MOVES IN
THERE IS A SLIGHT CHANCE OF PRECIPITATION ALONG A WARM FRONT
MOVING THROUGH THE REGION WEDNESDAY MORNING NORTH CENTRAL. CURRENT POPS
ARE LOW (20) WITH THE NAM DRY AND THE GFS JUST SPOTTY LIGHT
PRECIP. MODEL SOUNDINGS ARE FAIRLY DRY IN THE LOW LAYERS WHICH IS
PROBLEMATIC FOR DETERMINING PRECIP TYPE. COOLING THE THERMAL
PROFILES TO THE WET BULB RESULT IN ALL SNOW. BUT BOURGOUIN PROCESS
FROM THE BUFKIT ANALYSIS WANTS TO PAINT SOME LIGHT FREEZING RAIN.
ALL IN ALL ONLY 20 POPS SO DECENT CHANCE IT WILL BE DRY AFTER ALL.
FOR NOW LEFT IF SLIGHT CHANCE FOR SNOW. THURSDAY AND FRIDAY SHOW A
NICE WARM UP INTO THE 40S SOUTHWEST TO THE 30S CENTRAL AND NORTH.
THE REMAINDER OF THE EXTENDED WILL HAVE SOME SPOTTY PRECIPITATION
WITH LOW POPS THROUGH OUT AS THE MID LEVEL FLOW OR JET STREAM
ENERGY REMAINS MODERATE TO STRONG BUT MOISTURE IS WEAK. THE RESULT
WILL BE FAST MOVING SYSTEM WITH LITTLE MOISTURE,
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1225 PM CST TUE JAN 13 2015
A BAND OF CLOUDS IS PROJECTED TO MOVE SOUTHEASTWARD ACROSS THE
STATE. THIS BAND WAS CREATING IFR CONDITIONS WITH LIGHT SNOW IN
KISN. MVFR-IFR CONDITIONS ARE EXPECTED IN EACH OF THE TAF
SITES...AS THE CLOUDS MOVE FROM WEST TO EAST. THE LATEST RAP MODEL
HAS A GOOD HANDLE ON CURRENT CONDITIONS AND PROJECTS THE BAND
HOLDING TOGETHER AND MOVING INTO KBIS AND KJMS...LATER THIS
AFTERNOON AND THIS EVENING RESPECTIVELY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...WAA
AVIATION...AC
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1130 AM CST TUE JAN 13 2015
.UPDATE...
ISSUED AT 1104 AM CST TUE JAN 13 2015
HAVE EXPIRED THE WIND CHILL ADVISORY ON SCHEDULE FOR OUR NORTHEAST
AS TEMPERATURES RISE. ALSO HAVE INCREASED THE CHANCE OF LIGHT
SNOW FOR THE SAME AREA FOR LATE THIS AFTERNOON INTO THIS EVENING.
SHORT TERM MODELS AGREE ON ENOUGH LIFT IN THE DENDRITIC ZONE TO
GIVE ACCUMULATIONS POSSIBLY UP TO AN INCH.
UPDATE ISSUED AT 933 AM CST TUE JAN 13 2015
HAVE LET THE WIND CHILL ADVISORY EXPIRE ON SCHEDULE EXCEPT FOR
THE NORTHEAST...MAINLY SOUTHWEST MN...WHICH IS SCHEDULED TO
EXPIRE AT 11 AM. TEMPERATURES RISING SLOWLY BUT STEADILY. A COUPLE
OF COLD WIND CHILL READINGS IN NORTHWEST IA DUE TO WINDS ABOUT 5
MPH WILL BE ALLEVIATING SHORTLY. NO MAJOR CHANGES
OTHERWISE...THOUGH HAVE GONE SLIGHTLY FASTER ON THE CLOUD INCREASE
EAST THIS AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CST TUE JAN 13 2015
CENTER OF THE ARCTIC DOME OF HIGH PRESSURE HAS SHIFTED EAST AND
RETURN FLOW ON THE BACKSIDE OF THE HIGH HAS BEGUN TO INCREASE ACROSS
A LARGE PORTION OF THE AREA. WITH COLD DENSE AIR LINGERING AND
WINDS INCREASING...HAVE EXTENDED WIND CHILL ADVISORY ACROSS THE
EAST THROUGH 17Z.
HAVE SOME VERY SPOTTY FOG ACROSS THE AREA THIS MORNING. THE HRRR IS
NOT DOING A GOOD JOB IN PICKING THIS UP...BUT THE RAP IS SOMEWHAT
BETTER BUT MAY BE AN OVERSTATEMENT ON FOG. HAVE ADDED PATCHY
WORDING FROM NEAR SIOUX FALLS DOWN INTO NORTHWEST IOWA...BUT PATCHY
MAY BE AN OVERSTATEMENT GIVEN THE FLAKY NATURE OF THIS FOG.
OTHERWISE...FOCUS TODAY IS ON WAVE MIGRATING DOWN FROM
SASKATCHEWAN INTO MINNESOTA LATE IN THE DAY. MODELS SHOW THE
DYNAMICS SCRAPING OUR AREA...AND HAVE RAISED POPS ACCORDINGLY.
AGREE WITH PREVIOUS FORECASTER THAT SNOW AMOUNTS WILL NOT AMOUNT
TO MUCH...AS WAVE IS RELATIVELY QUICK MOVING AND SNOW SHOULD NOT
LAST IN ANY GIVEN LOCATION MORE THAN A FEW HOURS. HIGH
TEMPERATURES WILL BE WARMER THAN YESTERDAY...BUT IT WILL STILL BE
A STRUGGLE TO SHAKE THE SINGLE DIGITS IN THE EAST.
BOUNDARY MOVES THROUGH THE AREA TONIGHT...WITH WARMER AIR FOLLOWING
BEHIND THE FRONT. CLOUDS GRADUALLY CLEAR BEHIND THE WAVE LEADING TO
A BIT OF RADIATIONAL COOLING...BUT DO NOT THINK TEMPERATURES WILL
FALL MUCH WITH WARMER AIR MOVING IN. THE GREATEST COOLING WILL OCCUR
IN THE WEST WHERE CLEAR CONDITIONS WILL PERSIST LONGER THROUGH THE
NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 324 AM CST TUE JAN 13 2015
A NORTHWEST FLOW ALOFT WILL CHARACTERIZE THE REST OF THE FORECAST
WITH OCCASIONAL SHORT WAVES DIVING SOUTHEAST GRAZING THIS AREA.
WEDNESDAY FINALLY USHERS IN SOME MILDER AIR...WITH 925MB
TEMPERATURES SUGGESTING 20 TO 25 FOR HIGHS ALONG AND EAST OF
INTERSTATE 29...PROGRESSIVELY WARMING TO AROUND 30 AT CHAMBERLAIN.
AS THEY WERE YESTERDAY...BOTH THE NAM AND GFS ARE SHOWING A HINT AT
SOME STRATUS WEST OF I 29 THROUGH MIDDAY WEDNESDAY...BEFORE
EVAPORATING THE CLOUDS SOMEWHAT THROUGH THE AFTERNOON HOURS AS THEY
TRY TO PROGRESS EAST. BUT AT ANY RATE CONDITIONS LOOK DRY.
THEN A MILD AIR MASS IS IN PLACE THURSDAY AND FRIDAY WITH 925MB
TEMPERATURES WELL ABOVE FREEZING. CURRENT THOUGHTS ARE THAT IT
APPEARS THAT MANY CONSENSUS GUIDANCE VALUES ARE A LITTLE COLD FOR
OUR SOUTHWEST ZONES...EXCEPT FOR MOS VALUES. THEREFORE BLENDED IN
MOS TO GIVE GREGORY COUNTY MID 40S FOR HIGHS ON THURSDAY AND
FRIDAY...WITH THE REST OF THE FORECAST AREA IN THE 30S GOING
ISOTHERMAL FROM 925MB.
FOR THE REMAINDER OF THE FORECAST SATURDAY THROUGH MONDAY...THERE IS
THE USUAL MODEL DISCREPANCY BETWEEN THE VARIOUS DETERMINISTIC
MODELS. BUT OVERALL IT STILL LOOKS DRY NO MATTER WHAT SOLUTION IS
OUT THERE WITH MILD WEATHER CONTINUING FOR MID JANUARY STANDARDS.
SATURDAY MAY BE RATHER WINDY BEHIND A SURFACE TROUGH PASSAGE WITH
DIRECTIONS FROM THE NORTHWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1130 AM CST TUE JAN 13 2015
ALONG AND NORTHEAST OF A HON/FSD/SLB LINE...AREAS OF CEILINGS
2-4K FEET AND VISIBILITIES 3-5SM IN LIGHT SNOW WILL SPREAD
SOUTHEAST THROUGH 14/00Z. LOCAL VISIBILITIES BELOW 3SM IN SNOW
DEVELOPING ALONG AND NORTHEAST OF A BKX/OTG LINE. VISIBILITIES
IMPROVING TO P6SM FROM THE NORTHWEST 21Z-14/06Z...WHILE AREAS OF
CEILINGS 2-4K FEET CONTINUE THROUGH 14/18Z. SOUTHWEST OF A
HON/FSD/SLB LINE...A FEW AREAS OF CEILINGS 2-4K OTRW VFR.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...MJ
AVIATION...
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1025 AM MST TUE JAN 13 2015
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 302 AM MST TUE JAN 13 2015
LATEST WATER VAPOR IMAGERY SHOWS SOME WEAK ENERGY PASSING THROUGH
SOUTHWESTERN SOUTH DAKOTA WITH PRIMARILY ZONAL FLOW ACROSS THE
FORECAST AREA. AT THE SURFACE...HIGH PRESSURE IS OVER THE CENTRAL
PLAINS WITH A LEE TROF ACROSS EASTERN WYOMING. RADAR AND SURFACE
OBSERVATIONS INDICATE SOME LIGHT SNOW/FLURRIES ACROSS SOUTHWESTERN
SOUTH DAKOTA AND AROUND NEWCASTLE.
FOR THIS MORNING...COULD SEE SOME PATCHY FOG ACROSS PORTIONS OF
NORTHEASTERN WYOMING AND WESTERN SOUTH DAKOTA AS NAM AND RAPID
REFRESH MODEL INDICATES A SHALLOW LAYER OF MOISTURE NEAR THE
SURFACE. DON/T EXPECT FOG TO BE WIDESPREAD DUE TO THE LOW/MID LEVEL
CLOUDS CURRENTLY SPREADING ACROSS THE AREA. ALSO THE BAND OF LIGHT
SNOW/FLURRIES WILL CONTINUE TO PUSH EASTWARD FROM SOUTHWESTERN SOUTH
DAKOTA INTO SOUTH CENTRAL SOUTH DAKOTA. THUS ADDED SOME SLIGHT POPS
FOR THIS AREA THIS MORNING. OTHERWISE CLOUDS WILL DECREASE THIS
AFTERNOON FROM WEST TO EAST WITH 850-700MB WARM AIR ADVECTION IN
WESTERLY FLOW.
FOR TONIGHT...WILL SEE CLOUDS DISSIPATING EVEN MORE...BECOMING
MOSTLY CLEAR ACROSS THE AREA. LATEST HRRR AND NAM DOES INDICATE THE
POSSIBILITY OF FOG IN SOUTH CENTRAL SOUTH DAKOTA AROUND WINNER LATE
TONIGHT. HOWEVER WITH DRY AIR PUSHING IN FROM THE WEST...WILL LEAVE
IT OUT FOR NOW AND LET THE DAY SHIFT RE-EXAMINE. TEMPERATURES SHOULD
FALL TO READINGS CLOSE TO GUIDANCE VALUES IN THE UPPER SINGLE DIGITS
TO TEENS.
FOR WEDNESDAY AND WEDNESDAY NIGHT...THE WARMING TREND WILL BEGIN AS
HIGH PRESSURE BUILDS ACROSS THE WESTERN CONUS AND ROCKIES. WITH
LIMITED SKY COVER AND WESTERLY WINDS...EXPECT TEMPERATURES TO BE
NEAR TO SLIGHTLY ABOVE SEASONAL AVERAGES.
.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 302 AM MST TUE JAN 13 2015
UPPER LEVEL RIDGING SETS UP OVER THE WESTERN AND CENTRAL CONUS
FOR MUCH OF THE EXTENDED PERIOD. THIS SHOULD BRING DRY CONDITIONS
AND NEAR TO ABOVE AVERAGE TEMPERATURES TO THE AREA. BREEZY
WESTERLY WINDS WILL HELP TEMPS WARM INTO THE 40S AND LOWER 50S
THURSDAY AND FRIDAY. A COOL FRONT EARLY SATURDAY WILL REDUCE HIGHS
A BIT FOR THE WEEKEND...BUT WILL STILL BE NEAR TO ABOVE AVERAGE. A
COUPLE OF DRY SHORTWAVES MOVE THROUGH THE RIDGE DURING THE
EXTENDED PERIOD...BUT MODELS ARE HINTING AT A MORE ACTIVE PATTERN
WITH SNOW POSSIBLE EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 1024 AM MST TUE JAN 13 2015
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...MLS
LONG TERM...POJORLIE
AVIATION...15
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1103 AM CST TUE JAN 13 2015
.UPDATE...
ISSUED AT 1104 AM CST TUE JAN 13 2015
HAVE EXPIRED THE WIND CHILL ADVISORY ON SCHEDULE FOR OUR NORTHEAST
AS TEMPERATURES RISE. ALSO HAVE INCREASED THE CHANCE OF LIGHT
SNOW FOR THE SAME AREA FOR LATE THIS AFTERNOON INTO THIS EVENING.
SHORT TERM MODELS AGREE ON ENOUGH LIFT IN THE DENDRITIC ZONE TO
GIVE ACCUMULATIONS POSSIBLY UP TO AN INCH.
UPDATE ISSUED AT 933 AM CST TUE JAN 13 2015
HAVE LET THE WIND CHILL ADVISORY EXPIRE ON SCHEDULE EXCEPT FOR
THE NORTHEAST...MAINLY SOUTHWEST MN...WHICH IS SCHEDULED TO
EXPIRE AT 11 AM. TEMPERATURES RISING SLOWLY BUT STEADILY. A COUPLE
OF COLD WIND CHILL READINGS IN NORTHWEST IA DUE TO WINDS ABOUT 5
MPH WILL BE ALLEVIATING SHORTLY. NO MAJOR CHANGES
OTHERWISE...THOUGH HAVE GONE SLIGHTLY FASTER ON THE CLOUD INCREASE
EAST THIS AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CST TUE JAN 13 2015
CENTER OF THE ARCTIC DOME OF HIGH PRESSURE HAS SHIFTED EAST AND
RETURN FLOW ON THE BACKSIDE OF THE HIGH HAS BEGUN TO INCREASE ACROSS
A LARGE PORTION OF THE AREA. WITH COLD DENSE AIR LINGERING AND
WINDS INCREASING...HAVE EXTENDED WIND CHILL ADVISORY ACROSS THE
EAST THROUGH 17Z.
HAVE SOME VERY SPOTTY FOG ACROSS THE AREA THIS MORNING. THE HRRR IS
NOT DOING A GOOD JOB IN PICKING THIS UP...BUT THE RAP IS SOMEWHAT
BETTER BUT MAY BE AN OVERSTATEMENT ON FOG. HAVE ADDED PATCHY
WORDING FROM NEAR SIOUX FALLS DOWN INTO NORTHWEST IOWA...BUT PATCHY
MAY BE AN OVERSTATEMENT GIVEN THE FLAKY NATURE OF THIS FOG.
OTHERWISE...FOCUS TODAY IS ON WAVE MIGRATING DOWN FROM
SASKATCHEWAN INTO MINNESOTA LATE IN THE DAY. MODELS SHOW THE
DYNAMICS SCRAPING OUR AREA...AND HAVE RAISED POPS ACCORDINGLY.
AGREE WITH PREVIOUS FORECASTER THAT SNOW AMOUNTS WILL NOT AMOUNT
TO MUCH...AS WAVE IS RELATIVELY QUICK MOVING AND SNOW SHOULD NOT
LAST IN ANY GIVEN LOCATION MORE THAN A FEW HOURS. HIGH
TEMPERATURES WILL BE WARMER THAN YESTERDAY...BUT IT WILL STILL BE
A STRUGGLE TO SHAKE THE SINGLE DIGITS IN THE EAST.
BOUNDARY MOVES THROUGH THE AREA TONIGHT...WITH WARMER AIR FOLLOWING
BEHIND THE FRONT. CLOUDS GRADUALLY CLEAR BEHIND THE WAVE LEADING TO
A BIT OF RADIATIONAL COOLING...BUT DO NOT THINK TEMPERATURES WILL
FALL MUCH WITH WARMER AIR MOVING IN. THE GREATEST COOLING WILL OCCUR
IN THE WEST WHERE CLEAR CONDITIONS WILL PERSIST LONGER THROUGH THE
NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 324 AM CST TUE JAN 13 2015
A NORTHWEST FLOW ALOFT WILL CHARACTERIZE THE REST OF THE FORECAST
WITH OCCASIONAL SHORT WAVES DIVING SOUTHEAST GRAZING THIS AREA.
WEDNESDAY FINALLY USHERS IN SOME MILDER AIR...WITH 925MB
TEMPERATURES SUGGESTING 20 TO 25 FOR HIGHS ALONG AND EAST OF
INTERSTATE 29...PROGRESSIVELY WARMING TO AROUND 30 AT CHAMBERLAIN.
AS THEY WERE YESTERDAY...BOTH THE NAM AND GFS ARE SHOWING A HINT AT
SOME STRATUS WEST OF I 29 THROUGH MIDDAY WEDNESDAY...BEFORE
EVAPORATING THE CLOUDS SOMEWHAT THROUGH THE AFTERNOON HOURS AS THEY
TRY TO PROGRESS EAST. BUT AT ANY RATE CONDITIONS LOOK DRY.
THEN A MILD AIR MASS IS IN PLACE THURSDAY AND FRIDAY WITH 925MB
TEMPERATURES WELL ABOVE FREEZING. CURRENT THOUGHTS ARE THAT IT
APPEARS THAT MANY CONSENSUS GUIDANCE VALUES ARE A LITTLE COLD FOR
OUR SOUTHWEST ZONES...EXCEPT FOR MOS VALUES. THEREFORE BLENDED IN
MOS TO GIVE GREGORY COUNTY MID 40S FOR HIGHS ON THURSDAY AND
FRIDAY...WITH THE REST OF THE FORECAST AREA IN THE 30S GOING
ISOTHERMAL FROM 925MB.
FOR THE REMAINDER OF THE FORECAST SATURDAY THROUGH MONDAY...THERE IS
THE USUAL MODEL DISCREPANCY BETWEEN THE VARIOUS DETERMINISTIC
MODELS. BUT OVERALL IT STILL LOOKS DRY NO MATTER WHAT SOLUTION IS
OUT THERE WITH MILD WEATHER CONTINUING FOR MID JANUARY STANDARDS.
SATURDAY MAY BE RATHER WINDY BEHIND A SURFACE TROUGH PASSAGE WITH
DIRECTIONS FROM THE NORTHWEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 534 AM CST TUE JAN 13 2015
VFR CONDITIONS EXPECTED THROUGH 18Z. THEREAFTER...WEAK DISTURBANCE
WILL MOVE THROUGH POTENTIALLY PRODUCING A FEW FLURRIES ALONG
HIGHWAY 14 INCLUDING KHON...BUT DID NOT INCLUDE IN TAF. AS
BOUNDARY MOVES THROUGH...MVFR CEILINGS WILL DEVELOP AND PREVAIL
THROUGH THE REMAINDER OF THE PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...MJ
AVIATION...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1239 PM EST TUE JAN 13 2015
.SYNOPSIS...
COLD HIGH PRESSURE BUILDING NORTH OF THE REGION THIS MORNING
WILL WEDGE SOUTH ALONG THE EASTERN SLOPES OF THE APPALACHIANS
THIS AFTERNOON THROUGH WEDNESDAY. A WEAK UPPER LEVEL
DISTURBANCE WILL PASS TO THE SOUTHEAST OF THE AREA LATE TONIGHT
BRINGING ANOTHER ROUND OF LIGHT WINTRY PRECIPITATION TO SOUTHERN
SECTIONS INTO WEDNESDAY. ANOTHER AREA OF HIGH PRESSURE BUILDS IN
FROM THE WEST LATER IN THE WEEK RESULTING IN DRIER AND WARMER
WEATHER FOR LATE WEEK INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 940 AM EST TUESDAY...
FORECAST IS IN GOOD SHAPE. LATEST SURFACE ANALYSIS SHOWS THE COLD
FRONT HAVING PUSHED SOUTHWESTWARD THROUGH MUCH OF THE CWA... HAVING
CLEARED ALL BUT THE SW SECTIONS. THE WEDGE REGIME DEVELOPMENT IS
WELL UNDERWAY WITH SURFACE WINDS EAST OF THE SLOPES OUT OF THE
NORTHEAST... AND WITH SATELLITE AND 12Z SOUNDINGS CONFIRMING
ABUNDANT LOW LEVEL MOIST AIR... WE`RE SEEING WEAK TERRAIN-UPGLIDE
RADAR RETURNS ON THE EAST SLOPES. THE INITIAL SURGE OF DRIER SURFACE
DEWPOINTS INTO THE AREA IS ALLOWING FOR A SURFACE DEWPOINT
DEPRESSION OF A FEW DEGREES... ENOUGH TO MINIMIZE ANY PRECIP
AMOUNTS. THE LATEST HRRR RUNS SUPPORT VERY LIGHT PATCHY PRECIP
PERSISTING THROUGH THIS AFTERNOON... WITH SLIGHTLY BETTER COVERAGE
IN THE SW AND LESS IN THE NE WHERE THE INFLUX OF DRIER AIR IN THE
LOW LEVELS WILL LIMIT AMOUNTS. BASED UPON THE SURFACE WET BULB
OBSERVATIONS... EXPECT THIS TO BE MOSTLY DRIZZLE EAST OF THE
MOUNTAINS (DUE TO THE DRYING ALOFT) FOR THE NEXT SEVERAL HOURS...
WITH LIGHT FREEZING DRIZZLE OR PERHAPS A LITTLE LIGHT SLEET IN THE
HIGHER ELEVATIONS. CURRENT FORECAST HAS THIS COVERED WELL WITH LOW
POPS SUGGESTING LOW COVERAGE. STILL EXPECT ONLY MINOR IMPACTS
THROUGH THIS AFTERNOON WITH THE PATCHY NATURE OF THE PRECIP... AND
WILL MAINTAIN THIS MENTION IN THE HWO. TEMPS SHOULD HOLD STEADY FOR
ANOTHER FEW HOURS BEFORE BEGINNING TO SLIP BACK THROUGH THE LOW 30S
LATE IN THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
AS OF 330 AM EST TUESDAY...
WILL START TONIGHT OFF WITH HIGH PRESSURE FIRMLY WEDGED AGAINST THE
EASTERN FACE OF THE APPALACHIANS...STRETCHING SOUTHWARD FROM NEW
ENGLAND ACROSS THE MID ATLANTIC. NORTHEASTERLY WIND FLOW WILL
CONTINUE TO DRAW VERY CHILLY AIR ACROSS OUR AREA...PUSHING OVERNIGHT
TEMPERATURES INTO THE 20S MOST LOCATIONS...WITH A FEW UPPER TEENS
POSSIBLE ALONG THE BLUE RIDGE.
ANOTHER AREA OF LOW PRESSURE WILL DEVELOP ALONG THE COAST LATE THIS
EVENING AS A SUPPORTING UPPER LEVEL TROUGH APPROACHES FROM THE WEST.
MOISTURE RADIATING INLAND FROM THE LOW WILL INTERACT WITH WITH THE
COLD AIR WEDGE TO BRING ANOTHER ROUND OF WINTRY PRECIPITATION TO
GENERALLY THE SOUTHERN THIRD OF OUR FORECAST AREA...THE FOOTHILLS
AND PIEDMONT OF NORTH CAROLINA INTO SOUTHSIDE VIRGINIA. THE DEPTH OF
THE COLD AIR WEDGE WITH TEMPERATURES WELL BELOW FREEZING IS SEVERAL
THOUSAND FEET THICK...SUPPORTING SLEET AND POSSIBLY SNOW FOR OUR
AREA...ALTHOUGH WOULD NOT BE SURPRISED TO SEE A FEW REPORTS OF
FREEZING RAIN ACROSS THE SOUTHERN PORTIONS OF CASWELL AND POSSIBLY
ROCKINGHAM COUNTIES OVERNIGHT WHERE THE LAYER OF SUB FREEZING
TEMPERATURES ABOVE THE SURFACE IS NOT AS THICK. BEST SUPPORT WILL
PASS SOUTH AND EAST OF OUR AREA OVERNIGHT...MEANING THAT WE WILL
RECEIVE A GLANCING BLOW FROM THIS SYSTEM FOR THE MOST PART. SLEET
ACCUMULATIONS WILL BE LESS THAN A QUARTER INCH...WITH PERHAPS A
GLAZING OF ICE. CONSIDERING THIS WILL BE THE FIRST WINTRY
PRECIPITATION FOR SPOTS IN THIS PART OF THE FORECAST AREA...WILL
ISSUE A WINTER WEATHER ADVISORY FROM 7 PM TONIGHT THROUGH NOON ON
WEDNESDAY DUE TO THE POTENTIAL IMPACTS TO TRAVEL.
WITH THE SYSTEM EXITING THE AREA ON WEDNESDAY AFTERNOON...EXPECT A
DRYING TREND TO TAKE PLACE AS HIGH PRESSURE OVER THE OHIO RIVER
VALLEY WILL BECOME THE DOMINANT FEATURE IN OUR WEATHER PATTERN.
CLOUD COVER AND LOW LEVEL MOISTURE WILL BE A LITTLE SLOW TO ERODE ON
WEDNESDAY NIGHT...SO WOULD NOT BE SURPRISED TO SEE A FEW FLURRIES OR
PATCHES OF LIGHT FREEZING DRIZZLE ACROSS THE MOUNTAINS. HOWEVER...
WITH WINDS GRADUALLY BECOMING WESTERLY BY SUNRISE THURSDAY...WILL
SEE A CLEARING TREND TAKE PLACE...WHICH WILL ALLOW AFTERNOON
TEMPERATURES TO RANGE FROM THE UPPER 30S WEST TO THE MID 40S EAST. A
WEAK COLD FRONT IS EXPECTED TO PASS ACROSS THE AREA LATE THURSDAY
NIGHT...WITH THE SUPPORTING UPPER LEVEL TROUGH BRINGING GUSTY
NORTHWEST WINDS TO THE MOUNTAINS TOWARD SUNRISE FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 145 PM EST MONDAY...
THIS PORTION OF THE FORECAST PACKAGE WILL BE CHARACTERIZED BY ABOVE
NORMAL TEMPERATURES AND LIMITED CHANCES OF PRECIPITATION.
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION FRIDAY AND
SATURDAY...ALL WHILE AN UPPER LEVEL RIDGE STRENGTHENS OVER THE HIGH
PLAINS THEN RETROGRADES WEST. IN TIME...THIS WILL ALLOW FOR A
GREATER POTENTIAL FOR NORTHWEST FLOW...AND CLIPPER SYSTEMS TO MOVE
THROUGH THE GREAT LAKES REGION AND INTO THE MID-ATLANTIC STATES.
OUR FORECAST WILL REFLECT DRY CONDITIONS FRIDAY AND SATURDAY FOR THE
ENTIRE FORECAST AREA AND LIMITED CLOUD COVER. SATURDAY WILL BE
WARMER THAN FRIDAY BY AN AVERAGE OF THREE TO SIX DEGREES WITH LOWER
50S COMMON ACROSS THE PIEDMONT AND MID 40S TO AROUND 50 DEGREES IN
THE MOUNTAINS.
FOR SUNDAY AND MONDAY...GUIDANCE VARIES ON THE TIMING AND
IMPACT...BUT ONE OF THE AFOREMENTIONED CLIPPER SYSTEMS MAY IMPACT
THE REGION. LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT...THERE WILL BE
A SLIGHT CHANCE OF RAIN/SNOW SHOWERS ACROSS WESTERN GREENBRIER
COUNTY. BY MONDAY AFTERNOON...THAT SLIGHT CHANCE EXPANDS TO MOST OF
SOUTHEAST WEST VIRGINIA AND POTENTIALLY SOME OF THE NEIGHBORING
COUNTIES OF SOUTHWEST VIRGINIA. HIGHS ON SUNDAY WILL BE SLIGHTLY
MILDER THAN THOSE OF SATURDAY. HOWEVER...ON MONDAY WITH GREATER
PROBABILITY FOR CLOUD COVER...AND A POTENTIAL SURFACE COLD FRONTAL
PASSAGE...TEMPERATURES WILL BE SLIGHTLY COOLER...COMPARABLE TO THOSE
OF SATURDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 1238 PM EST TUESDAY...
SURFACE COLD FRONT WAS LOCATED SOUTH OF THE AREA WITH THE LOW
LEVEL FLOW OF NORTH TO NORTHEAST CONTINUING STRATUS/STRATO-CU AT
MOST LOCATIONS. WEDGE SCENARIO WILL CONTINUE THIS AFTERNOON INTO
TONIGHT AS HIGH PRESSURE BUILDS SOUTH. THIS SHOULD KEEP WIDESPREAD
MVFR TO IFR CIGS IN MOST LOCATIONS. SOME DRIER AIR MAY NOSE SOUTH
INTO KLYH...BUT MODELS LOOKED OVERDONE ON THIS. LIGHT WINTERY MIX
EXPECTED THIS AFTERNOON INTO TONIGHT. PATCHY -DZ OR -FZDZ EXPECTED
AT KBLF/KROA/KBCB.
AN UPPER LEVEL DISTURBANCE WILL PASS ACROSS TONIGHT AND EARLY
WEDNESDAY. THIS FEATURE MAY RESULT IN ANOTHER PERIOD OF LIGHT
WINTRY MIX AS WELL AS SOME ADDITIONAL FREEZING DRIZZLE AND RIME
ICING. THIS MOST LIKELY AROUND KDAN WHERE MOISTURE WILL BE DEEPER
AND CLOSER TO THE MAIN SWATH OF PRECIP PASSING TO THE SE. ELSW
SOME POTENTIAL FOR AREAS OF -FZDZ/PL WITH MORE FREEZING TYPE
PRECIP AT KBLF PER SHALLOW MOISTURE...AND SLEET/SNOW ELSW BUT
LIGHT ENOUGH TO PRECLUDE MUCH BELOW HIGH END MVFR AT WORSE OUTSIDE
OF FOG.
ANY PRECIP SHOULD TAPER FROM WEST TO EAST WEDNESDAY MORNING WITH
LINGERING LOW CLOUDS SLOWLY ERODING IN THE AFTERNOON AS DRIER AIR
WORKS EAST. THIS MAY ALLOW SOME SITES ALONG/EAST OF THE BLUE RIDGE
TO RECOVER TO LATE DAY VFR CIGS OTRW MAINLY MVFR THROUGH THE DAY.
MEDIUM CONFIDENCE ON CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED AVIATION DISCUSSION...
AFTER THE PASSAGE OF THIS FEATURE WEDNESDAY...A PUSH OF MUCH
DRIER AIR WILL INFILTRATE THE MID ATLANTIC REGION WITH VFR
LIKELY FROM WEDNESDAY NIGHT INTO SATURDAY UNDER HIGH PRESSURE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO NOON EST
WEDNESDAY FOR VAZ032-043-044-058-059.
NC...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO NOON EST
WEDNESDAY FOR NCZ003>006-019-020.
WV...NONE.
&&
$$
SYNOPSIS...JH/KK
NEAR TERM...JH/KK/GIH
SHORT TERM...NF
LONG TERM...DS/NF
AVIATION...JH/PM/KK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
251 PM MST TUE JAN 13 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 233 PM MST TUE JAN 13 2015
WEATHER CONDITIONS WILL BE TRANSITIONING TO SLIGHTLY WARMER TEMPS AND
LESS LOW CLOUD COVER THROUGH WED. WATER VAPOR IMAGERY SHOWS AN
UPPER LOW SPINNING ACROSS NORTHERN ARIZONA WITH LARGE SCALE ASCENT
ACROSS SOUTHWESTERN COLORADO. LOW CLOUDS HAVE BEEN PERSISTENT OVER
MUCH OF THE CWA...HOWEVER BEGINNING TO SEE SOME RAISING CIGS AS
THE LLVLS ARE STARTING TO DRY. SFC PRESSURES ARE RISING AND A COLD
FRONT IS MOVING OVER THE SOUTHERN ZONES RIGHT NOW WITH CHEYENNE
GETTING NORTHERLY WIND GUSTS TO 30 MPH. LLVL RH PROGS AND
SOUNDINGS INDICATE THAT LOW CLOUDS WILL CONTINUE TO CLEAR THROUGH
THE EVENING AND EARLY NIGHT. ADDED SOME PATCHY FOG OVER PORTIONS
OF CARBON COUNTY AS WINDS ARE REALLY LIGHT AND RUC SOUNDINGS
SHOULD A GOOD LLVL INVERSION AND SATURATION. IT WILL BE ANOTHER
CHILLY NIGHT ESPECIALLY WITH CLEARING SKIES.
HEIGHTS ALOFT RISE ON WED WITH LIGHT WESTERLY SFC WINDS OVER MUCH
OF THE REGION. STARTING TO GET SOME WEAK PRESSURE FALLS TO THE
EAST OF THE LARAMIE RANGE HOWEVER THE CAG-CPR GRADIENT REMAINS
BELOW 30 METERS. TEMPS WILL MODERATE SOME COMPARED TO TODAY (5-10
DEGREES WARMER) HOWEVER THE PRONOUNCED DOWNSLOPING AND WARMING
WILL NOT ARRIVE UNTIL THURS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 233 PM MST TUE JAN 13 2015
WEDNESDAY NIGHT/THURSDAY...NORTH NORTHWEST FLOW ALOFT TRANSITIONS TO
NORTHWEST. MILD WEATHER ENTHUSIASTS WILL ENJOY THURSDAY AS DOWNSLOPE
WARMING AND A MODERATING AIRMASS HELPS HIGH TEMPERATURES TO SOAR
WELL INTO THE 40S AND LOWER 50S EAST OF I-25 AND 30S WEST OF I-25.
FRIDAY...FLOW ALOFT BACKS EVEN MORE TO WEST...INDUCING EVEN MORE
DOWNSLOPE WARMING AND WITH PROGGED THICKNESSES AND 700 MB
TEMPERATURES...WE EXPECT MAXIMUM TEMPERATURES TO SOAR WELL INTO THE
40S TO MID 50S AT LOWER ELEVATIONS ASSUMING MIDDLE AND HIGH CLOUD
OPACITY...THICKNESS...IS MINIMAL. OUR WIND PRONE LOCATIONS MAY BE
NEAR HIGH WIND CRITERIA BASED ON THE PROGGED LOW AND MID LEVEL
GRADIENTS.
SATURDAY...POTENT ALBERTA CLIPPER SHORTWAVE TROUGH ALOFT SWEEPS
ACROSS THE NORTHERN PLAINS STATES WITH THE ASSOCIATED COLD FRONT
SLIDING ACROSS OUR COUNTIES EARLY IN THE DAY...USHERING IN WINDY
CONDITIONS ALONG WITH HIGH TEMPERATURES BACK INTO THE 30S TO MID 40S
AT LOWER ELEVATIONS. COULD SEE A FEW LOCATIONS NEAR HIGH WIND
CRITERIA IN THE FEW HOURS AFTER COLD FRONTAL PASSAGE DUE TO A BORA
EVENT.
SUNDAY...THE ROLLER COASTER CONTINUES WITH THE FLOW ALOFT TURNING
WEST NORTHWEST...INDUCING MORE SURFACE LEE TROUGHING AND AIDING
WARMING TEMPERATURES INTO THE 40S AND LOWER 50S AT LOWER ELEVATIONS.
MONDAY...ANOTHER FAST MOVING SHORTWAVE TROUGH ALOFT SWEEPS ACROSS
THE NORTHERN ROCKIES SENDING ANOTHER COLD FRONT INTO OUR COUNTIES IN
THE AFTERNOON AND PRODUCING A COOLING TREND. WILL SEE SCATTERED
OROGRAPHIC SNOWS OVER THE SNOWY AND SIERRA MADRE RANGES...DRY
ELSEWHERE.
TUESDAY...WINDY AND COLD WITH A FEW MOUNTAIN SNOW SHOWERS...AS A
BROAD TROUGH ALOFT PREVAILS OVER THE NORTHERN PLAINS STATES SENDING
REINFORCING COLD AIR SOUTHWARD ACROSS OUR COUNTIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1039 AM MST TUE JAN 13 2015
WIDESPREAD IFR/MVFR CONDITIONS WILL OCCUR THROUGH THE AFTERNOON.
THE LOW LEVELS WILL BEGIN TO DRY AFTER 00Z WITH LOW CLOUDS
BECOMING LESS EXTENSIVE. A WEAK FRONT WILL CAUSE WINDS TO GO
NORTHERLY...HOWEVER WINDSPEEDS WILL GENERALLY BE LESS THAN 15 KTS.
&&
.FIRE WEATHER...
ISSUED AT 233 PM MST TUE JAN 13 2015
NO CRITICAL FIRE WEATHER CONDITIONS OVER THE NEXT FEW DAYS.
WIDESPREAD SNOW COVER REMAINS ON THE GROUND. TEMPERATURES WILL
WARM TO AROUND NORMAL BY THURSDAY...HOWEVER MINIMUM AFTERNOON
HUMIDITY VALUES WILL STILL BE ABOVE 30 PERCENT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...RUBIN
AVIATION...ZF
FIRE WEATHER...ZF