Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/19/16
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
140 PM PST SUN JAN 17 2016
.SYNOPSIS...A STRONG STORM SYSTEM WILL SPREAD RAIN ACROSS THE
REGION TODAY THROUGH MONDAY MORNING. A PERIOD OF HEAVY RAIN IS
LIKELY...BEGINNING IN THE NORTH BAY THIS AFTERNOON AND ACROSS
THE REMAINDER OF THE FORECAST AREA TONIGHT AND EARLY MONDAY. A
SECOND STORM WILL PRODUCE MORE RAINFALL AND LOCALLY STRONG WINDS
LATE MONDAY NIGHT THROUGH TUESDAY. THERE MAY BE A BRIEF PERIOD OF
DRY WEATHER AROUND THE MIDDLE OF THE WEEK BEFORE ANOTHER STORM
SYSTEM ARRIVES LATE IN THE WEEK.
&&
.DISCUSSION...AS OF 01:35 PM PST SUNDAY...THE MAIN STORY THROUGH
THE ENTIRE FORECAST IS ACTIVE WEATHER CONTINUES. A SERIES OF STORMS WILL
CONTINUE TO BRING PERIODS RAIN TO THE ENTIRE BAY AREA.
IN THE SHORT TERM...THE MAIN FOCUS CONTINUES TO BE THE ATMOSPHERICRIVER
SLOWLY MARCHING SOUTHWARD DOWN THE CALIFORNIA COAST. SINCE THIS
MORNING...RADAR ECHOES HAVE INCREASED SUBSTANTIALLY OVER THE NORTH
BAY AND OFF THE COAST. SINCE THIS MORNING...A FEW HUNDREDTHS TO A
TENTH OR TWO OF RAIN HAS FALLEN. EXPECT THIS TO CHANGE AS A COLD
FRONT AND ASSOCIATED MOISTURE PLUME MOVES SOUTH OVER THE BAY AREA
THIS AFTERNOON INTO TONIGHT. LATEST SATELLITE IMAGERY SHOWS THAT
PWATS OF 1.5 INCHES ARE LURKING OFF THE COAST...SO THERE IS
DEFINITELY MOISTURE TO WORK WITH. ALL THAT BEING SAID...ONLY
MINOR TWEAKS TO THE PREVIOUS FORECAST. BASED ON THE LATEST MODELS
AND SATELLITE TIMING...THE FRONT WILL MOVE INTO THE N BAY CLOSE TO
0-6Z TONIGHT AND JUST NORTH OF SAN JOSE BY 12Z MONDAY AND THEN
MONTEREY BY 18Z. GIVEN THE AMPLE MOISTURE...THERE WILL LIKELY BE A
PERIOD OF MODERATE TO HEAVY RAIN WITH THE FROPA. RAINFALL TOTALS
1.0-2.5 INCHES LOCALLY UP TO 3.5 INCHES WILL BE POSS OVER THE N
BAY/SANTA CRUZ MTS/BIG SUR COAST...ELSEWHERE 0.25 TO 1 INCH. GIVEN
THE POSSIBILITY OF MODERATE TO HEAVY RAIN WILL LEAVE FLASH FLOOD
WATCH AS IS FOR THE NORTH BAY. OTHER POTENTIAL HYDRO PROBLEMS
COULD ARISE IN THE COASTAL MOUNTAINS OF MONTEREY/SANTA CRUZ WHERE
HIGHER RAINFALL AMOUNTS ARE EXPECTED. HOWEVER...CONF IS NOT HIGH
ENOUGH TO WARRANT A FLASH FLOOD WATCH. ADDITIONALLY...LARGE SURF
IS STILL FORECAST TO ARRIVE LATER TODAY. THE COMBINATION OF LARGE
SURF...EXCESSIVE RUNOFF AND HIGH TIDE WILL LEAD TO SOME COASTAL
FLOODING. THEREFORE...THE COASTAL FLOOD WARNING REMAINS IN EFFECT
THIS AFTERNOON THROUGH MONDAY MORNING. LASTLY...THERE WILL BE A
BRIEF PERIOD OF GUSTY WINDS...BUT DEFINITELY BELOW ADVISORY
LEVELS. IN SUMMARY...THE BULK OF THE RAIN HAS YET TO ARRIVE AND
THE HEAVIEST WILL LIKELY OCCUR FROM 06-15Z MONDAY.
FOR MONDAY...THE COLD FRONT WILL MOVE SOUTHWARD AND EXIT THE CWA
LEAVING SHOWERS BEHIND IT. BRIEF BREAK IN THE ACTION SO TO SPEAK
MONDAY AFTERNOON AND MONDAY NIGHT BEFORE ANOTHER SYSTEM ARRIVES
TUESDAY. SPEAKING OF MONDAY NIGHT...LATEST GUIDANCE HAS HAD A
DRYING TREND MONDAY NIGHT. THEREFORE...TRIMMED BACK ON POPS 00-12Z
TUESDAY.
RAIN WILL RE-DEVELOP OVER THE NORTH BAY EARLY TUESDAY MORNING
THEN SPREAD SOUTHWARD THROUGH THE DAY. THE HEAVIEST RAINFALL WILL
ONCE AGAIN BE OVER THE NORTH BAY AND COASTAL MOUNTAINS...1-2
INCHES. LOWER ELEVATIONS 0.25-0.75 INCHES BY TUESDAY NIGHT.
MODELS CONTINUE TO ADVERTISE A BRIEF BREAK WITH SHORTWAVE RIDGING
ON WEDNESDAY AND WEDNESDAY NIGHT. THE RIDGE SHIFTS EAST WITH
ANOTHER ROUND OF RAIN EXPECTED THURSDAY NIGHT INTO FRIDAY...WITH
MORE RAIN POSSIBLE NEXT WEEKEND.
&&
.AVIATION...AS OF 9:30 AM PST SUNDAY...MAIN FOCUS FOR THE 18Z
PACKAGE WAS FOR TIMING OF THE RAIN AS A FRONT MOVES THROUGH OUR
AREA TODAY AND TONIGHT. LAST THREE RUNS OF THE HRRR HAVE ONLY
SLIGHTLY CHANGED, SO CONFIDENCE IN THE TIMING LISTED IN THE TAF IS
FAIRLY HIGH. WINDS ALSO ON TRACK TO INCREASE AS THE FRONT NEARS.
RAIN ENDS NEAR THE END OR JUST OUTSIDE OF THE TAF PACKAGE.
MODERATE TO HIGH CONFIDENCE FOR TIMING. MODERATE CONFIDENCE ON
VIS AND CIG HEIGHTS.
VICINITY OF KSFO...MVFR CIGS FORECAST THROUGH MOST OF THE PERIOD.
-RA RETURN AROUND 23Z OR 0Z WITH POTENTIAL FOR RA OR EVEN +RA AT
OR A BIT AFTER 04Z. WINDS OF 170 TO 190 AROUND 10 KT. SPEEDS WILL
INCREASE WITH GUSTS OVER 20 KT POSSIBLE AFTER 23Z. MODERATE TO
HIGH CONFIDENCE.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MOSTLY MVFR VFR CONDITIONS THROUGH
THE DAY WITH -RA EXPECTED AFTER 04Z. WINDS GENERALLY 170 TO 190 AT
KMRY TO 10 KT. AT KSNS WINDS OF 130 TO 150 FORECAST WITH GUSTS
OVER 20 KT AFTER 02Z. MODERATE CONFIDENCE.
&&
.BEACHES...AS OF 10:00 AM PST SUNDAY... AN APPROACHING LONG PERIOD
WEST SWELL WILL BRING HAZARDOUS CONDITIONS TO REGIONAL BEACHES
THROUGH MONDAY. WEST SWELLS WILL STEADILY INCREASE TO 16 TO 19 FEET
WITH A PERIOD OF 17 TO 19 SECONDS TODAY. EXTREME WAVE RUN UP IS
EXPECTED WITH THIS SWELL AS LONG LULLS IN BETWEEN WAVE SETS WILL
INCREASE RISK OF DEADLY RIP CURRENTS...LARGE SNEAKER WAVES... AND
THE LIKELIHOOD OF BEING WASHED INTO SEA BY A WAVE. SMALL VESSELS
ALONG THE IMMEDIATE COAST MAY ALSO BE PUSHED INTO COASTAL ROCKS.
DURING HIGH TIDE... COASTAL INUNDATION MAY CUT OFF ACCESS TO SOME
BEACHES AND OUTCROPPINGS. THE LARGE WAVES WILL GRADUALLY TAPER OFF
EARLY NEXT WEEK.
&&
.MARINE...AS OF 08:33 AM PST SUNDAY...LOOK FOR INCREASING
SOUTHERLY WINDS TODAY AS A SYSTEM MOVES THROUGH. THE STRONGEST
WINDS WILL BE OVER THE NORTHERN WATERS. WINDS WILL DECREASE
TONIGHT AFTER THE FRONT PASSES BUT ANOTHER SYSTEM WILL INCREASE
THE WINDS AGAIN TUESDAY. A LARGE SWELL TRAIN GENERATED BY THESE
SERIES OF STORMS WILL AFFECT THE WATERS THROUGH AT LEAST MONDAY
MORNING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...COASTAL FLOOD WARNING...ALL COASTAL ZONES AS WELL AS NORTH
BAY ZONES BORDERING SF BAY.
HIGH SURF WARNING...ALL COASTAL ZONES FROM SONOMA TO
MONTEREY COUNTY.
FLASH FLOOD WATCH...NORTH BAY COUNTIES OF SONOMA...NAPA
AND MARIN.
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: MM
AVIATION: BELL
MARINE: BELL
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
958 AM PST SUN JAN 17 2016
.SYNOPSIS...A STRONG STORM SYSTEM WILL SPREAD RAIN ACROSS THE
REGION TODAY THROUGH MONDAY MORNING. A PERIOD OF HEAVY RAIN IS
LIKELY...BEGINNING IN THE NORTH BAY THIS AFTERNOON AND ACROSS
THE REMAINDER OF THE FORECAST AREA TONIGHT AND EARLY MONDAY. A
SECOND STORM WILL PRODUCE MORE RAINFALL AND LOCALLY STRONG WINDS
LATE MONDAY NIGHT THROUGH TUESDAY. THERE MAY BE A BRIEF PERIOD OF
DRY WEATHER AROUND THE MIDDLE OF THE WEEK BEFORE ANOTHER STORM
SYSTEM ARRIVES LATE IN THE WEEK.
&&
.DISCUSSION...AS OF 09:06 AM PST SUNDAY...SHORT TERM CONCERNS
WILL CONTINUE TO FOCUS ON THE APPROACHING COLD FRONT AND VERY
ROBUST MOISTURE PLUME CURRENTLY POINTED NORCAL. OVERNIGHT THE RAIN
BUCKETS IN THE NORTH BAY HAVE BEEN STEADILY TIPPING WITH VENADO
WELL OVER AN INCH WITH MANY OTHER LOCATIONS IN THE 0.25 TO 0.5
INCH RANGE. THE LATEST KMUX RADAR IMAGERY MAY NOT BE OVERLY
IMPRESSIVE FOR THE NORTH BAY...BUT RAIN IS STILL BEING REPORTED.
THERE HAVE ALSO BEEN A FEW REPORTS OF MEASURABLE RAIN OVER
PORTIONS OF CONTRA COSTA COUNTY.
FOR THE REST OF TODAY...THE COLD FRONT WILL CONTINUE TO SLOWLY
MOVE SOUTHWARD. THE LATEST HRRR ACTUALLY HANDLES THIS FAIRLY WELL
WITH THE BULK OF THE PRECIP NOT ARRIVING UNTIL LATER THIS
AFTERNOON. DID A QUICK UPDATE TO THE FORECAST TO SLOW DOWN THE
ONSET OF THE HEAVIER PRECIP TODAY AND TO LOWER RAINFALL AMOUNTS
THIS MORNING. FOR MORE SPECIFIC DETAILS ON THE WEATHER SYSTEM SEE
BELOW.
&&
.PREV DISCUSSION...AS OF 3:30 AM PST SUNDAY...EARLY MORNING IR
SATELLITE IMAGERY SHOWS A FRONTAL BOUNDARY EXTENDING FROM THE FAR
NORTHERN CALIFORNIA COAST WSW OVER THE PACIFIC. THE MOISTURE PLUME
COINCIDENT WITH THIS BOUNDARY CONTAINS PRECIPITABLE WATER VALUES
EXCEEDING 1.5 INCHES WITH A MAXIMUM OF 2 INCHES. A STRONG
SHORTWAVE TROUGH CURRENTLY RIDING ALONG THE FRONTAL BOUNDARY HAS
RESULTED IN STRONG ENHANCEMENT OF THE FRONT JUST OFF THE NORTHERN
CA COAST NORTH OF CAPE MENDOCINO...WITH EMBEDDED CONVECTION AND
NUMEROUS LIGHTNING STRIKES IN THAT AREA. THE MODELS HAVE BEEN
CONSISTENT IN GRADUALLY SLIDING THE FRONTAL BOUNDARY AND
ASSOCIATED ENHANCED RAINFALL SOUTH THROUGH OUR FORECAST AREA LATER
TODAY AND TONIGHT. THE LATEST MODELS HAVE DELAYED THE ONSET OF
HEAVIEST RAINFALL A BIT. BASED ON A CONSENSUS OF THE MODELS...THE
HEAVIEST RAINFALL IN THE NORTH BAY IS EXPECTED FROM EARLY THIS
AFTERNOON THROUGH EARLY EVENING...THEN FROM EARLY EVENING THROUGH
LATE TONIGHT FOR THE REST OF THE SF BAY AREA AND SANTA CRUZ
COUNTY...AND FROM ABOUT MIDNIGHT THROUGH SUNRISE MONDAY MORNING
FOR MONTEREY AND SAN BENITO COUNTIES. RAIN RATES ARE EXPECTED TO
BE HEAVY FOR A FEW HOURS WHILE THE FRONTAL BOUNDARY MOVES THROUGH.
THE MAIN CONCERN IS WHETHER THE BAND OF HEAVY RAIN WILL SLOW
SIGNIFICANTLY OR STALL IN ONE PARTICULAR AREA. THE 00Z NAM
INDICATED A WAVE WOULD DEVELOP ALONG THE FRONT EARLY THIS EVENING
AND MAINTAIN HEAVY RAIN RATES IN THE NORTH BAY FOR A MORE
PROLONGED PERIOD OF TIME. THE 06Z NAM DELAYS THE DEVELOPMENT OF
THIS FRONTAL WAVE AND INSTEAD STALLS THE BAND OF HEAVIER RAIN
ACROSS SANTA CRUZ COUNTY AND THE SOUTH BAY OVERNIGHT. ON THE OTHER
HAND...BOTH THE GFS AND ECMWF MOVE THE FRONTAL BOUNDARY THROUGH
OUR ENTIRE AREA AT A STEADY PACE. IN ANY CASE...ALL OF THE MODELS
INDICATE THAT THE GREATEST RAINFALL TOTALS THROUGH MIDDAY MONDAY
WILL BE ACROSS THE NORTH BAY. WILL THEREFORE CONTINUE WITH A FLASH
FLOOD WATCH FOR SONOMA...NAPA AND MARIN COUNTIES THROUGH LATE
TONIGHT.
FOR AREAS SOUTH OF THE GOLDEN GATE....AT LEAST MINOR HYDRO ISSUES
ARE LIKELY TONIGHT...ESPECIALLY IN THE SANTA CRUZ MOUNTAINS AND
SOUTH BAY IF THE 06Z NAM WERE TO VERIFY. WILL CONTINUE TO
HIGHLIGHT THE POSSIBILITY OF MINOR URBAN AND/OR SMALL STREAM
FLOODING WITH A HAZARDOUS WEATHER OUTLOOK FOR ALL AREAS NOT
INCLUDED IN THE FLASH FLOOD WATCH. IN ADDITION...A COMBINATION OF
LARGE POWERFUL OCEAN SWELL AND HEAVY RAINFALL RUNOFF WILL LIKELY
PRODUCE AT LEAST MINOR COASTAL FLOODING...PARTICULARLY AROUND THE
TIMES OF HIGH TIDE NEAR 6 PM THIS EVENING AND THEN AGAIN AROUND 6
AM ON MONDAY MORNING. A COASTAL FLOOD WARNING IS IN EFFECT FROM 4
PM TODAY UNTIL 7 AM MONDAY FOR ALL COASTAL ZONES AS WELL AS AREAS
AROUND THE NORTHERN SAN FRANCISCO BAY...PARTICULARLY BAYSIDE
LOCATIONS OF MARIN COUNTY.
WINDS WITH THIS SYSTEM ARE NOT EXPECTED TO REACH ADVISORY LEVELS.
THERE WILL BE MODERATELY STRONG AND GUSTY SOUTHERLY WINDS NEAR THE
COAST AND LOCALLY IN THE HILLS FROM THIS AFTERNOON THROUGH
TONIGHT...WHEN WIND GUSTS UP TO 35 MPH ARE POSSIBLE.
INDICATIONS ARE THAT RAINFALL WILL TAPER OFF PRETTY QUICKLY ON
MONDAY MORNING AND MOSTLY END BY MONDAY AFTERNOON. THERE WILL BE
ONLY A SHORT BREAK IN THE ACTION BEFORE THE NEXT SYSTEM SWEEPS IN
LATE MONDAY NIGHT AND TUESDAY. THE TUESDAY SYSTEM IS EXPECTED TO
MOVE THROUGH PRETTY QUICKLY...WHICH WILL HELP MITIGATE HYDRO
PROBLEMS. HOWEVER...RAINFALL COULD BE HEAVY FOR A SHORT TIME ON
TUESDAY AND WITH SATURATED SOILS EVEN SHORT-DURATION HEAVY RAIN
EVENTS CAN RESULT IN AT LEAST MINOR HYDRO PROBLEMS. IN
ADDITION...WINDS WITH THE TUESDAY SYSTEM ARE EXPECTED TO BE
SOMEWHAT STRONGER THAN THE SUNDAY/SUNDAY NIGHT SYSTEM. BUT THE
LATEST WRF WIND FORECAST HAS BACKED OFF ON WINDS ON TUESDAY AND
SO THERE MAY NOT BE A NEED FOR WIND ADVISORIES WITH THIS SECOND
SYSTEM EITHER.
MOST OF OUR FORECAST AREA SHOULD GET A CHANCE TO DRY OUT A BIT
AROUND MIDWEEK AS A SHORTWAVE RIDGE BUILDS OVER CA TEMPORARILY.
BUT ANOTHER ROUND OF RAINFALL IS LIKELY BY LATE IN THE WEEK. THE
TIMING OF THE LATE-WEEK SYSTEM IS SOMEWHAT UNCERTAIN AS WOULD BE
EXPECTED WITH AN ACTIVE WEATHER PATTERN SEVERAL DAYS IN ADVANCE.
BUT INDICATIONS ARE THAT FRIDAY WILL LIKELY BE WET...WITH YET MORE
RAIN POSSIBLE NEXT WEEKEND.
&&
.AVIATION...AS OF 9:30 AM PST SUNDAY...MAIN FOCUS FOR THE 18Z
PACKAGE WAS FOR TIMING OF THE RAIN AS A FRONT MOVES THROUGH OUR
AREA TODAY AND TONIGHT. LAST THREE RUNS OF THE HRRR HAVE ONLY
SLIGHTLY CHANGED, SO CONFIDENCE IN THE TIMING LISTED IN THE TAF IS
FAIRLY HIGH. WINDS ALSO ON TRACK TO INCREASE AS THE FRONT NEARS.
RAIN ENDS NEAR THE END OR JUST OUTSIDE OF THE TAF PACKAGE.
MODERATE TO HIGH CONFIDENCE FOR TIMING. MODERATE CONFIDENCE ON
VIS AND CIG HEIGHTS.
VICINITY OF KSFO...MVFR CIGS FORECAST THROUGH MOST OF THE PERIOD.
-RA RETURN AROUND 23Z OR 0Z WITH POTENTIAL FOR RA OR EVEN +RA AT
OR A BIT AFTER 04Z. WINDS OF 170 TO 190 AROUND 10 KT. SPEEDS WILL
INCREASE WITH GUSTS OVER 20 KT POSSIBLE AFTER 23Z. MODERATE TO
HIGH CONFIDENCE.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MOSTLY MVFR VFR CONDITIONS THROUGH
THE DAY WITH -RA EXPECTED AFTER 04Z. WINDS GENERALLY 170 TO 190 AT
KMRY TO 10 KT. AT KSNS WINDS OF 130 TO 150 FORECAST WITH GUSTS
OVER 20 KT AFTER 02Z. MODERATE CONFIDENCE.
&&
.BEACHES...AS OF 10:00 AM PST SUNDAY... AN APPROACHING LONG PERIOD
WEST SWELL WILL BRING HAZARDOUS CONDITIONS TO REGIONAL BEACHES
THROUGH MONDAY. WEST SWELLS WILL STEADILY INCREASE TO 16 TO 19 FEET
WITH A PERIOD OF 17 TO 19 SECONDS TODAY. EXTREME WAVE RUN UP IS
EXPECTED WITH THIS SWELL AS LONG LULLS IN BETWEEN WAVE SETS WILL
INCREASE RISK OF DEADLY RIP CURRENTS...LARGE SNEAKER WAVES... AND
THE LIKELIHOOD OF BEING WASHED INTO SEA BY A WAVE. SMALL VESSELS
ALONG THE IMMEDIATE COAST MAY ALSO BE PUSHED INTO COASTAL ROCKS.
DURING HIGH TIDE... COASTAL INUNDATION MAY CUT OFF ACCESS TO SOME
BEACHES AND OUTCROPPINGS. THE LARGE WAVES WILL GRADUALLY TAPER OFF
EARLY NEXT WEEK.
&&
.MARINE...AS OF 08:33 AM PST SUNDAY...LOOK FOR INCREASING
SOUTHERLY WINDS TODAY AS A SYSTEM MOVES THROUGH. THE STRONGEST
WINDS WILL BE OVER THE NORTHERN WATERS. WINDS WILL DECREASE
TONIGHT AFTER THE FRONT PASSES BUT ANOTHER SYSTEM WILL INCREASE
THE WINDS AGAIN TUESDAY. A LARGE SWELL TRAIN GENERATED BY THESE
SERIES OF STORMS WILL AFFECT THE WATERS THROUGH AT LEAST MONDAY
MORNING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...COASTAL FLOOD WARNING...ALL COASTAL ZONES AS WELL AS NORTH
BAY ZONES BORDERING SF BAY.
HIGH SURF WARNING...ALL COASTAL ZONES FROM SONOMA TO
MONTEREY COUNTY.
FLASH FLOOD WATCH...NORTH BAY COUNTIES OF SONOMA...NAPA
AND MARIN.
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: MM
AVIATION: BELL
MARINE: BELL
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
909 AM PST SUN JAN 17 2016
.SYNOPSIS...A STRONG STORM SYSTEM WILL SPREAD RAIN ACROSS THE
REGION TODAY THROUGH MONDAY MORNING. A PERIOD OF HEAVY RAIN IS
LIKELY...BEGINNING IN THE NORTH BAY THIS AFTERNOON AND ACROSS
THE REMAINDER OF THE FORECAST AREA TONIGHT AND EARLY MONDAY. A
SECOND STORM WILL PRODUCE MORE RAINFALL AND LOCALLY STRONG WINDS
LATE MONDAY NIGHT THROUGH TUESDAY. THERE MAY BE A BRIEF PERIOD OF
DRY WEATHER AROUND THE MIDDLE OF THE WEEK BEFORE ANOTHER STORM
SYSTEM ARRIVES LATE IN THE WEEK.
&&
.DISCUSSION...AS OF 09:06 AM PST SUNDAY...SHORT TERM CONCERNS
WILL CONTINUE TO FOCUS ON THE APPROACHING COLD FRONT AND VERY
ROBUST MOISTURE PLUME CURRENTLY POINTED NORCAL. OVERNIGHT THE RAIN
BUCKETS IN THE NORTH BAY HAVE BEEN STEADILY TIPPING WITH VENADO
WELL OVER AN INCH WITH MANY OTHER LOCATIONS IN THE 0.25 TO 0.5
INCH RANGE. THE LATEST KMUX RADAR IMAGERY MAY NOT BE OVERLY
IMPRESSIVE FOR THE NORTH BAY...BUT RAIN IS STILL BEING REPORTED.
THERE HAVE ALSO BEEN A FEW REPORTS OF MEASURABLE RAIN OVER
PORTIONS OF CONTRA COSTA COUNTY.
FOR THE REST OF TODAY...THE COLD FRONT WILL CONTINUE TO SLOWLY
MOVE SOUTHWARD. THE LATEST HRRR ACTUALLY HANDLES THIS FAIRLY WELL
WITH THE BULK OF THE PRECIP NOT ARRIVING UNTIL LATER THIS
AFTERNOON. DID A QUICK UPDATE TO THE FORECAST TO SLOW DOWN THE
ONSET OF THE HEAVIER PRECIP TODAY AND TO LOWER RAINFALL AMOUNTS
THIS MORNING. FOR MORE SPECIFIC DETAILS ON THE WEATHER SYSTEM SEE
BELOW.
&&
.PREV DISCUSSION...AS OF 3:30 AM PST SUNDAY...EARLY MORNING IR
SATELLITE IMAGERY SHOWS A FRONTAL BOUNDARY EXTENDING FROM THE FAR
NORTHERN CALIFORNIA COAST WSW OVER THE PACIFIC. THE MOISTURE PLUME
COINCIDENT WITH THIS BOUNDARY CONTAINS PRECIPITABLE WATER VALUES
EXCEEDING 1.5 INCHES WITH A MAXIMUM OF 2 INCHES. A STRONG
SHORTWAVE TROUGH CURRENTLY RIDING ALONG THE FRONTAL BOUNDARY HAS
RESULTED IN STRONG ENHANCEMENT OF THE FRONT JUST OFF THE NORTHERN
CA COAST NORTH OF CAPE MENDOCINO...WITH EMBEDDED CONVECTION AND
NUMEROUS LIGHTNING STRIKES IN THAT AREA. THE MODELS HAVE BEEN
CONSISTENT IN GRADUALLY SLIDING THE FRONTAL BOUNDARY AND
ASSOCIATED ENHANCED RAINFALL SOUTH THROUGH OUR FORECAST AREA LATER
TODAY AND TONIGHT. THE LATEST MODELS HAVE DELAYED THE ONSET OF
HEAVIEST RAINFALL A BIT. BASED ON A CONSENSUS OF THE MODELS...THE
HEAVIEST RAINFALL IN THE NORTH BAY IS EXPECTED FROM EARLY THIS
AFTERNOON THROUGH EARLY EVENING...THEN FROM EARLY EVENING THROUGH
LATE TONIGHT FOR THE REST OF THE SF BAY AREA AND SANTA CRUZ
COUNTY...AND FROM ABOUT MIDNIGHT THROUGH SUNRISE MONDAY MORNING
FOR MONTEREY AND SAN BENITO COUNTIES. RAIN RATES ARE EXPECTED TO
BE HEAVY FOR A FEW HOURS WHILE THE FRONTAL BOUNDARY MOVES THROUGH.
THE MAIN CONCERN IS WHETHER THE BAND OF HEAVY RAIN WILL SLOW
SIGNIFICANTLY OR STALL IN ONE PARTICULAR AREA. THE 00Z NAM
INDICATED A WAVE WOULD DEVELOP ALONG THE FRONT EARLY THIS EVENING
AND MAINTAIN HEAVY RAIN RATES IN THE NORTH BAY FOR A MORE
PROLONGED PERIOD OF TIME. THE 06Z NAM DELAYS THE DEVELOPMENT OF
THIS FRONTAL WAVE AND INSTEAD STALLS THE BAND OF HEAVIER RAIN
ACROSS SANTA CRUZ COUNTY AND THE SOUTH BAY OVERNIGHT. ON THE OTHER
HAND...BOTH THE GFS AND ECMWF MOVE THE FRONTAL BOUNDARY THROUGH
OUR ENTIRE AREA AT A STEADY PACE. IN ANY CASE...ALL OF THE MODELS
INDICATE THAT THE GREATEST RAINFALL TOTALS THROUGH MIDDAY MONDAY
WILL BE ACROSS THE NORTH BAY. WILL THEREFORE CONTINUE WITH A FLASH
FLOOD WATCH FOR SONOMA...NAPA AND MARIN COUNTIES THROUGH LATE
TONIGHT.
FOR AREAS SOUTH OF THE GOLDEN GATE....AT LEAST MINOR HYDRO ISSUES
ARE LIKELY TONIGHT...ESPECIALLY IN THE SANTA CRUZ MOUNTAINS AND
SOUTH BAY IF THE 06Z NAM WERE TO VERIFY. WILL CONTINUE TO
HIGHLIGHT THE POSSIBILITY OF MINOR URBAN AND/OR SMALL STREAM
FLOODING WITH A HAZARDOUS WEATHER OUTLOOK FOR ALL AREAS NOT
INCLUDED IN THE FLASH FLOOD WATCH. IN ADDITION...A COMBINATION OF
LARGE POWERFUL OCEAN SWELL AND HEAVY RAINFALL RUNOFF WILL LIKELY
PRODUCE AT LEAST MINOR COASTAL FLOODING...PARTICULARLY AROUND THE
TIMES OF HIGH TIDE NEAR 6 PM THIS EVENING AND THEN AGAIN AROUND 6
AM ON MONDAY MORNING. A COASTAL FLOOD WARNING IS IN EFFECT FROM 4
PM TODAY UNTIL 7 AM MONDAY FOR ALL COASTAL ZONES AS WELL AS AREAS
AROUND THE NORTHERN SAN FRANCISCO BAY...PARTICULARLY BAYSIDE
LOCATIONS OF MARIN COUNTY.
WINDS WITH THIS SYSTEM ARE NOT EXPECTED TO REACH ADVISORY LEVELS.
THERE WILL BE MODERATELY STRONG AND GUSTY SOUTHERLY WINDS NEAR THE
COAST AND LOCALLY IN THE HILLS FROM THIS AFTERNOON THROUGH
TONIGHT...WHEN WIND GUSTS UP TO 35 MPH ARE POSSIBLE.
INDICATIONS ARE THAT RAINFALL WILL TAPER OFF PRETTY QUICKLY ON
MONDAY MORNING AND MOSTLY END BY MONDAY AFTERNOON. THERE WILL BE
ONLY A SHORT BREAK IN THE ACTION BEFORE THE NEXT SYSTEM SWEEPS IN
LATE MONDAY NIGHT AND TUESDAY. THE TUESDAY SYSTEM IS EXPECTED TO
MOVE THROUGH PRETTY QUICKLY...WHICH WILL HELP MITIGATE HYDRO
PROBLEMS. HOWEVER...RAINFALL COULD BE HEAVY FOR A SHORT TIME ON
TUESDAY AND WITH SATURATED SOILS EVEN SHORT-DURATION HEAVY RAIN
EVENTS CAN RESULT IN AT LEAST MINOR HYDRO PROBLEMS. IN
ADDITION...WINDS WITH THE TUESDAY SYSTEM ARE EXPECTED TO BE
SOMEWHAT STRONGER THAN THE SUNDAY/SUNDAY NIGHT SYSTEM. BUT THE
LATEST WRF WIND FORECAST HAS BACKED OFF ON WINDS ON TUESDAY AND
SO THERE MAY NOT BE A NEED FOR WIND ADVISORIES WITH THIS SECOND
SYSTEM EITHER.
MOST OF OUR FORECAST AREA SHOULD GET A CHANCE TO DRY OUT A BIT
AROUND MIDWEEK AS A SHORTWAVE RIDGE BUILDS OVER CA TEMPORARILY.
BUT ANOTHER ROUND OF RAINFALL IS LIKELY BY LATE IN THE WEEK. THE
TIMING OF THE LATE-WEEK SYSTEM IS SOMEWHAT UNCERTAIN AS WOULD BE
EXPECTED WITH AN ACTIVE WEATHER PATTERN SEVERAL DAYS IN ADVANCE.
BUT INDICATIONS ARE THAT FRIDAY WILL LIKELY BE WET...WITH YET MORE
RAIN POSSIBLE NEXT WEEKEND.
&&
.AVIATION...AS OF 5:30 AM PST SUNDAY...LATEST GOES IMAGE SHOWS
LOW CIGS WITH LOCAL DRIZZLE OR LIGHT RAIN EXTENDS FROM THE SAN
MATEO COAST INTO THE NORTH BAY. TRICKY FORECAST TODAY AS SFO IS
RIGHT ON THE EDGE OF THE CLOUD DECK. COULD SEE SOME MVFR CIGS INTO
SFO FROM TIME TO TIME THIS MORNING. CHANCES FOR MVFR CIGS INCREASE
IN THE AFTERNOON AS THE FRONTAL SYSTEM APPROACHES. SOUTHEAST WINDS
WILL INCREASE BY THIS EVENING AS THE FRONT IS THEN FORECAST TO
PROGRESS SOUTH.
VICINITY OF KSFO...A MIX OF VFR AND MVFR CIGS THIS MORNING.
MVFR CIGS BECOMES MORE LIKELY AFTER 16Z. SOUTHEAST WINDS
REMAINING LIGHT AROUND 5 KT INCREASING TO 10 KT AFTER 17Z AND
15-20 KT AFTER 23Z.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...LIFR FOR CIGS AND VIS THROUGH 16Z.
IMPROVING TO MVFR AFTER 17Z AND VFR AFTER 19Z AS FOG CLEARS OUT.
&&
.BEACHES...AS OF 4:00 AM PST SUNDAY... AN APPROACHING LONG PERIOD
WEST SWELL WILL BRING HAZARDOUS CONDITIONS TO REGIONAL BEACHES
THROUGH MONDAY. WEST SWELLS WILL STEADILY INCREASE TO 16 TO 19 FEET
WITH A PERIOD OF 17 TO 19 SECONDS TODAY. EXTREME WAVE RUN UP IS
EXPECTED WITH THIS SWELL AS LONG LULLS IN BETWEEN WAVE SETS WILL
INCREASE RISK OF DEADLY RIP CURRENTS...LARGE SNEAKER WAVES... AND
THE LIKELIHOOD OF BEING WASHED INTO SEA BY A WAVE. SMALL VESSELS
ALONG THE IMMEDIATE COAST MAY ALSO BE PUSHED INTO COASTAL ROCKS.
DURING HIGH TIDE... COASTAL INUNDATION MAY CUT OFF ACCESS TO SOME
BEACHES AND OUTCROPPINGS. THE LARGE WAVES WILL GRADUALLY TAPER OFF
EARLY NEXT WEEK.
&&
.MARINE...AS OF 08:33 AM PST SUNDAY...LOOK FOR INCREASING
SOUTHERLY WINDS TODAY AS A SYSTEM MOVES THROUGH. THE STRONGEST
WINDS WILL BE OVER THE NORTHERN WATERS. WINDS WILL DECREASE
TONIGHT AFTER THE FRONT PASSES BUT ANOTHER SYSTEM WILL INCREASE
THE WINDS AGAIN TUESDAY. A LARGE SWELL TRAIN GENERATED BY THESE
SERIES OF STORMS WILL AFFECT THE WATERS THROUGH AT LEAST MONDAY
MORNING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...COASTAL FLOOD WARNING...ALL COASTAL ZONES AS WELL AS
NORTH BAY ZONES BORDERING SF BAY.
HIGH SURF WARNING...THE COAST FROM SONOMA COUNTY
SOUTH TO MONTEREY COUNTY.
FLASH FLOOD WATCH...NORTH BAY COUNTIES OF SONOMA...
NAPA AND MARIN
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: MM
AVIATION: W PI
MARINE: BELL
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
140 AM MST SUN JAN 17 2016
.SYNOPSIS...
HIGH PRESSURE OVER THE WESTERN STATES WILL FLUCTUATE IN STRENGTH BUT
OVERALL KEEP ANY WEATHER SYSTEMS TO THE NORTH OF ARIZONA. TEMPERATURES
WILL WARM THIS WEEKEND PEAKING A BIT ABOVE NORMAL BY MONDAY...AND
REMAINING NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS THROUGH NEXT
FRIDAY. DISTURBANCES PASSING THROUGH THE RIDGE WILL BRING PERIODS OF
MAINLY HIGH CLOUDS LEADING TO PARTLY SUNNY OR EVEN MOSTLY CLOUDY
SKIES AT TIMES.
&&
.DISCUSSION... AT 2 AM A FAST MOVING SHORT WAVE RIDING THROUGH AN
UPPER RIDGE CONTINUED TO PUSH EAST AND INTO NEW MEXICO. THIS SYSTEM
BROUGHT LITTLE IF ANY PRECIP TO THE AREA BUT DID USHER IN QUITE A
BIT OF THICK MID AND HIGH CLOUD COVER...SOME OF WHICH STILL LINGERS
OVER THE LOWER DESERTS AS SEEN IN THE CURRENT IR SATELLITE IMAGERY.
THE CLOUDS YESTERDAY KEPT HIGH TEMPS DOWN SEVERAL DEGREES ACROSS
SOUTH CENTRAL ARIZONA AND PHOENIX ONLY REACHED TO 62 DEGREES...WHICH
IS 5 DEGREES BELOW SEASONAL NORMALS.
THE LARGE SCALE WEATHER PATTERN THROUGH THE WEEK AND INTO THE
WEEKEND LOOKS TO BE A DRY ONE FOR SERN CA AND SRN ARIZONA AS IT WILL
BE DOMINATED BY LARGE SCALE RIDGING EACH DAY. THERE WILL BE A SERIES
OF SHORT WAVES MOVING THROUGH THE FLOW...TWO OF THE MORE PROMINENT
ONES WILL PASS BY MONDAY/MONDAY NIGHT AND TUESDAY NIGHT INTO EARLY
WEDNESDAY. THESE SYSTEMS WILL PRODUCE LITTLE IF ANY PRECIP...AND
POPS ALL WEEK WILL STAY IN THE SINGLE DIGITS. HOWEVER...THE CLOUDS
WILL USHER IN PERIODS OF THICK MID AND HIGH CLOUDS WHICH WILL SERVE
TO MODERATE OUR HIGH TEMPERATURES A BIT AND KEEP OUR LOWS ON THE
MILD SIDE. FOR THE MOST PART HIGH TEMPERATURES EACH DAY WILL STAY
NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS WITH THE WARMER DESERTS
OCCASIONALLY CLIMBING INTO THE LOWER OR EVEN MIDDLE 70S. THE WARMEST
DAYS THIS WEEK ARE EXPECTED TO BE THURSDAY AND FRIDAY...AS HIGH
PRESSURE ALOFT WILL BE THE STRONGEST ON THOSE DAYS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS THROUGH SUNDAY EVENING WITH ONLY
PERIODS OF THICKER HIGH CLOUDS (ABOVE 15K FT) OVER THE REGION. SFC
WINDS WILL REMAIN VERY LIGHT AOB 8KT...AND WILL BE VARIABLE OR CALM
FOR EXTENDED PERIODS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
HIGH PRESSURE WILL GENERALLY REMAIN IN PLACE OVER THE INTERIOR WESTERN
STATES GETTING WEAKENED FROM TIME TO TIME BY STORMS THAT PASS TO OUR
NORTH...ONLY BRUSHING ARIZONA AND SOUTHEAST CALIFORNIA. CHANCES FOR
ANY WETTING RAINS DURING THE WEEK WILL BE SLIM. HUMIDITIES INCREASE
BY WEDNESDAY DUE TO A PASSING WEATHER DISTURBANCE. THIS WILL BE
FOLLOWED BY DECLINING HUMIDITIES BUT REMAINING ABOVE 20 PERCENT.
OVERNIGHT RECOVERY REMAINS GOOD. TEMPERATURES WILL REMAIN NEAR NORMAL
THE FIRST HALF OF THE WEEK FOLLOWED BY A FEW DEGREES OF WARMING
DURING THE LATTER HALF. WINDS ON THE VALLEY FLOORS WILL REMAIN
LIGHT...OCCASIONAL BREEZINESS AT RIDGETOPS...FAVORING NORTH AND EAST
DIRECTIONS.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...CB
AVIATION...MO
FIRE WEATHER...AJ
Area Forecast Discussion
National Weather Service Sacramento CA
1015 PM PST SAT JAN 16 2016
.SYNOPSIS...
WET SYSTEM MOVING IN SUNDAY THROUGH EARLY MONDAY. SOME SMALL
SCALE AND/OR BURN SCAR FLOODING COULD OCCUR DURING THIS TIME.
EXPECT PERIODS OF PRECIPITATION THROUGH NEXT WEEK.
&&
.DISCUSSION...
Impressive moisture plume coming into view on satellite just off
the west coast. 00z model runs and short term HRRR all trending a
few hours slower with the system...but also wetter as they have
the heavier band stalling out into Monday morning. Heaviest
rain band will move into the north valley around 5am and sag
south to the southern valley by 7pm Sunday. Numerous showers will
develop ahead of this band and should begin over the north valley
after midnight and spread south Sunday morning.
In the near term, isolated areas of fog have developed especially
over the delta where KSUU and KVCB have occasionally went under a
mile. Not expecting this to last through the night...as cloud
cover and mixing with incoming system should improve conditions.
&&
.PREVIOUS DISCUSSION...
A series of storms will move through the region through Tuesday.
The current system is exiting the region with shower chances
continuing into the evening. Snow levels have been risen up to
around 7500 feet and will remain high through Tuesday but may dip
at times below major pass levels of US-50 and I-80. I have
modified the flash flood watch period to when the heavier rain is
expected to move through Lake County for Sunday afternoon and
evening. Timing of the later system on Tuesday may change a
little.
In the shorter term the NAM and HRRR models are indicating showers
enhancing around mid afternoon over the Southern Sacramento
Valley and Western Slopes of the Sierra Nevada. Showers should
taper some this evening then rain may start for places around I-80
and to the north later tonight and Sunday morning. The heaviest
rainfall is expected Sunday afternoon and evening. Sunday evening
snow levels look like they may lower below major Sierra pass
levels and have some impact on travel.
&&
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)
Unsettled weather pattern will continue through next week as
several storms move into NorCal from the Pacific. Forecast timing
will likely fluctuate over the next several runs under this
progressive pattern, but confidence is high in both a midweek and
late-week storm over the region. Snow levels will generally remain
around 5000-7000 feet before lowering next weekend. Temperatures
will be close to average for mid-January.
Dang
&&
.AVIATION...
Wly flow alf as upr rdg movs thru tngt...bckg to SWly Sun as nxt
Pac fntl sys movs into Intr NorCal. For Cstl/Shasta mtns and
Cntrl Vly...lcl MVFR/IFR bcmg wdsprd MVFR with areas IFR aft 12z
Sun. Ovr Wrn Plumas/Siernev lcl MVFR bcmg wdsprd MVFR/IFR with lcl
LIFR aft 17z Sun. Sn lvls genly aoa 055 msl. Lcl SEly sfc wnd gsts
to 30 kts Sun with SWly sfc wnd gsts to 40 kts poss ovr hyr mtn
trrn.
&&
.STO Watches/Warnings/Advisories...
Flash Flood Watch from Sunday afternoon through Sunday evening
for Clear Lake/Southern Lake County-Mountains Southwestern
Shasta County to Northern Lake County.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1034 AM MST SUN JAN 17 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM MST SUN JAN 17 2016
...SNOW AND WIND CONTINUES FOR THE CENTRAL MOUNTAINS TODAY...
NEXT UPPER WAVE IS CURRENTLY MOVING INTO NW CO...AND WILL CONTINUE
TO DROP SOUTHEASTWARD INTO THE TX PANHANDLE BY MID DAY. AREA RADARS
SHOWING PERSISTENT SNOW BANKED UP INTO THE NORTHWEST FACING SLOPES
OF CHAFFEE AND LAKE COUNTY...WITH LXV REPORTING A FEW HUNDREDTHS OF
PRECIPITATION EACH HOUR. LIKELY SOME PRETTY STOUT WINDS ACROSS THE
HIGHER ELEVATIONS...AS KCCU AND K7BM ARE REPORTING GUSTS 30-35
KTS...AND IT IS LIKELY THAT GUSTS AT PEAK LEVEL ARE PROBABLY AROUND
50 KTS OR BETTER BASED ON MODEL SOUNDINGS. FREMONT PASS WEBCAM HAS
BEEN SHOWING POOR VISIBILITIES AT TIMES WITH SNOW AND BLOWING SNOW.
LATEST HIGH RES MODELS HAVE COME IN HEAVIER WITH SNOWFALL ACROSS THE
HIGHER ELEVATIONS OF THE SAWATCH AND MOSQUITO RANGES WHICH JIVES
WELL WITH ABOVE OBSERVATIONS...AND HAVE ALREADY HOISTED A WINTER
WEATHER ADVISORY FOR ZONE 58 AND 60 THROUGH TODAY. HEAVIEST SNOW
WILL FALL THIS MORNING ASSOCIATED WITH THE BETTER FORCING/CAA. THEN
PERSISTENT NORTHWEST FLOW WILL PROVIDE FAVORABLE OROGRAPHICS FOR
SNOW SHOWERS TO CONTINUE THROUGH THE AFTERNOON...THOUGH AT LESSER
RATES. THAT COMBINED WITH THE PROBABILITY FOR BLOWING SNOW TO
CONTINUE...THE WINTER WEATHER ADVISORY WILL CARRY THROUGH 5 PM THIS
EVENING.
ALSO WATCHING THE ARCTIC COLD FRONT PUSH INTO EASTERN PORTIONS OF
THE PLAINS EARLY THIS MORNING WITH STRATUS AND TEMPERATURES IN THE
TEENS PUSHING SOUTHWESTWARD. LATEST HRRR BACKS THIS AIRMASS WESTWARD
INTO THE SOUTHEAST PLAINS THROUGH THE MORNING WITH POTENTIAL FOR
STRATUS TO SPREAD AS FAR WEST AS KLHX. COULD EVEN SEE SOME LOW
CLOUDS BRIEFLY FORM AT KPUB BY LATE MORNING...BUT ASSUMING MODELS
ARE HANDLING THE WESTWARD PUSH OF THE COLDER AIR...DON`T THINK
CLOUDS WILL BECOME PERSISTENT AT KPUB. THIS WILL POSE CHALLENGES FOR
MAX TEMPS TODAY THOUGH...AS NORTHWEST WINDS AND SLIGHTLY WARMER
TEMPERATURES ACROSS THE MTS AND LOWER EASTERN SLOPES WILL TRANSITION
INTO THE COLDER AIRMASS BANKED INTO THE SOUTHEAST PLAINS. GETTING
THIS GRADIENT IN THE CORRECT POSITION WILL BE KEY TO FORECASTING MAX
TEMPERATURES TODAY...AND WITH EASTERLY SFC WINDS EXPECTED AT
KPUB...KEPT TEMPERATURES BELOW GUIDANCE FOR THE LOWER ARKANSAS RIVER
VALLEY FROM KPUB EASTWARD. WOULDN`T BE SURPRISED TO SEE HIGHS ONLY
IN THE 20S ALONG THE KS BORDER THIS AFTERNOON. HAVE ALSO INCLUDED
SOME FOG IN THE GRIDS FOR THE FAR EASTERN PLAINS...AND WILL HAVE TO
WATCH FOR THE POTENTIAL FOR IT TO BECOME DENSE...OR EVEN PRODUCE
SOME SPOTTY FREEZING DRIZZLE LATER THIS MORNING AS LOWER ATMOS
SATURATES. ANY VIS RESTRICTIONS SHOULD BREAK BY NOON...AND MODELS
SUGGEST STRATUS WILL BREAK UP DURING THE MID AFTERNOON FOR FAR
EASTERN AREAS.
TONIGHT...LEE TROF KICKS EASTWARD AND ARCTIC AIRMASS RECEDES
EASTWARD ACROSS THE PLAINS. SHOULD BE A QUICK DROP IN TEMPERATURES
THIS EVENING THOUGH...ESPECIALLY FOR THE EASTERN PLAINS.
MEANWHILE...WESTERLY WINDS ACROSS THE MTS/I-25 CORRIDOR SHOULD KEEP
MIN TEMPS IN THE MID-UPPER 20S IN THE USUAL BREEZY SPOTS LIKE CANON
CITY AND WALSENBURG. TRICKY FORECAST AGAIN FOR KALS. GUIDANCE HAS
BEEN PERSISTENTLY UNDERDOING THE AMOUNT OF RADIATIONAL COOLING AT
NIGHT OVERTOP SNOWPACK ACROSS THE SAN LUIS VALLEY...ESPECIALLY IF
CLOUDS ARE LACKING. THERE WILL BE ANOTHER BOUT OF HIGH CLOUDS
SPILLING IN OVERTOP THE UPPER RIDGE AXIS TONIGHT...BUT APPEARS THAT
BETTER MOISTURE WILL STAY OFF TO THE NORTH AND WEST...SO HAVE
UNDERCUT GUIDANCE FOR MIN TEMPS FOR THE SAN LUIS VALLEY AGAIN
TONIGHT. WILL HAVE TO WATCH FOR THE EVER PRESENT THREAT FOR PATCHY
DENSE FOG ACROSS THE SAN LUIS VALLEY TONIGHT AS WELL. -KT
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 423 AM MST SUN JAN 17 2016
...SEVERAL DISTURBANCES TO BRING SNOW TO THE MOUNTAINS...
MONDAY THROUGH WEDNESDAY...MODELS HAVE BEEN VERY CONSISTENT IN
KEEPING AN ACTIVE UPPER PATTERN IN PLACE FOR THE REGION...AND
ESPECIALLY FOR THE HIGHER ELEVATIONS WITH A FOCUS ON THE CONTDVD. ONE
DISTURBANCE WILL CROSS MONDAY NIGHT INTO TUESDAY...AND THE SECOND
WILL CROSS ON WEDNESDAY. GIVEN THE GENERAL NW FLOW ALOFT...THE
CONTDVD WILL RECEIVE THE BRUNT OF THE NEW SNOWFALL...AND
PARTICULARLY THE CENTRAL MTS. EACH EVENT SHOULD BRING 1 TO 3 INCHES
OF NEW SNOW TO THE HIGHER TERRAIN OF LAKE AND CHAFFEE COUNTIES...AND
UP TO 2 INCHES FOR THE REMAINING MTS. MAX TEMPS EACH DAY ARE
EXPECTED TO CLIMB TO NEAR 50 F FOR THE PLAINS...AND INTO THE 30S TO
NEAR 40 F FOR THE HIGH VALLEYS.
THURSDAY THROUGH SATURDAY...A RIDGE OF HIGH PRESSURE BUILDS ACROSS
THE SOUTHWESTERN US...ALLOWING FOR DRY CONDITIONS ACROSS THE CWA FOR
THU AND FRI. MAX TEMPS ON THU SHOULD BE THE SAME AS EARLIER IN THE
WEEK...BUT FOR FRI AND SAT WILL WARM TO NEAR 60 F FOR THE
PLAINS...AND INTO THE MID 30S TO MID 40S FOR THE HIGH VALLEYS.
LATEST MODEL RUNS HINT AT ANOTHER UPPER WAVE CROSSING THE REGION FOR
SAT...BRINGING ISOLATED SNOW TO THE CONTDVD. HOWEVER...AT THIS TIME
THIS FEATURE LOOKS TO BE MORE OF A GLANCING BLOW TO THE
NORTH...WHICH WOULD KEEP SNOW AMOUNTS LIGHT WITH LITTLE EFFECT ON
TEMPS EAST OF THE MTS. MOORE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1024 AM MST SUN JAN 17 2016
AT KALS...VFR TODAY THEN IFR AFTER 10Z TONIGHT AS HIGH LEVEL
CLOUDINESS CLEARS...ALLOWING LOW CLOUDS AND PATCHY GROUND FOG TO
FORM NEAR THE RIO GRANDE. CONDITIONS THEN GRADUALLY IMPROVE BACK
TO VFR BY MIDDAY MON.
AT KCOS...VFR TODAY AND TONIGHT AS LOWER CLOUDS STAY EAST OF THE
TERMINAL.
AT KPUB...IFR STRATUS JUST EAST OF THE TERMINAL AT 17Z...BUT
WESTWARD EXPANSION OF THE LOW CLOUD DECK HAS JUST ABOUT
ENDED...WITH SOME EROSION FROM THE NORTH OCCURING AS WELL. WILL
THUS KEEP IFR CIGS OUT OF THE TAF AT THIS POINT...THOUGH IT WILL
BE A CLOSE CALL. VFR CONDITIONS THEN EXPECTED FOR THE REMAINDER OF
THE DAY AND OVERNIGHT.
OVER THE MOUNTAINS...STILL A FEW MOURE HOURS OF PATCHY IFR/LIFR
CONDITIONS IN SNOW AND BLOWING SNOW OVER THE CENTRAL MOUNTAINS
NORTH OF KMYP THIS AFTERNOON...THEN GRADUAL IMPROVEMENT OVERNIGHT
INTO MONDAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ058-
060.
&&
$$
SHORT TERM...KT
LONG TERM...MOORE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
424 AM MST SUN JAN 17 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM MST SUN JAN 17 2016
...SNOW AND WIND CONTINUES FOR THE CENTRAL MOUNTAINS TODAY...
NEXT UPPER WAVE IS CURRENTLY MOVING INTO NW CO...AND WILL CONTINUE
TO DROP SOUTHEASTWARD INTO THE TX PANHANDLE BY MID DAY. AREA RADARS
SHOWING PERSISTENT SNOW BANKED UP INTO THE NORTHWEST FACING SLOPES
OF CHAFFEE AND LAKE COUNTY...WITH LXV REPORTING A FEW HUNDREDTHS OF
PRECIPITATION EACH HOUR. LIKELY SOME PRETTY STOUT WINDS ACROSS THE
HIGHER ELEVATIONS...AS KCCU AND K7BM ARE REPORTING GUSTS 30-35
KTS...AND IT IS LIKELY THAT GUSTS AT PEAK LEVEL ARE PROBABLY AROUND
50 KTS OR BETTER BASED ON MODEL SOUNDINGS. FREMONT PASS WEBCAM HAS
BEEN SHOWING POOR VISIBILITIES AT TIMES WITH SNOW AND BLOWING SNOW.
LATEST HIGH RES MODELS HAVE COME IN HEAVIER WITH SNOWFALL ACROSS THE
HIGHER ELEVATIONS OF THE SAWATCH AND MOSQUITO RANGES WHICH JIVES
WELL WITH ABOVE OBSERVATIONS...AND HAVE ALREADY HOISTED A WINTER
WEATHER ADVISORY FOR ZONE 58 AND 60 THROUGH TODAY. HEAVIEST SNOW
WILL FALL THIS MORNING ASSOCIATED WITH THE BETTER FORCING/CAA. THEN
PERSISTENT NORTHWEST FLOW WILL PROVIDE FAVORABLE OROGRAPHICS FOR
SNOW SHOWERS TO CONTINUE THROUGH THE AFTERNOON...THOUGH AT LESSER
RATES. THAT COMBINED WITH THE PROBABILITY FOR BLOWING SNOW TO
CONTINUE...THE WINTER WEATHER ADVISORY WILL CARRY THROUGH 5 PM THIS
EVENING.
ALSO WATCHING THE ARCTIC COLD FRONT PUSH INTO EASTERN PORTIONS OF
THE PLAINS EARLY THIS MORNING WITH STRATUS AND TEMPERATURES IN THE
TEENS PUSHING SOUTHWESTWARD. LATEST HRRR BACKS THIS AIRMASS WESTWARD
INTO THE SOUTHEAST PLAINS THROUGH THE MORNING WITH POTENTIAL FOR
STRATUS TO SPREAD AS FAR WEST AS KLHX. COULD EVEN SEE SOME LOW
CLOUDS BRIEFLY FORM AT KPUB BY LATE MORNING...BUT ASSUMING MODELS
ARE HANDLING THE WESTWARD PUSH OF THE COLDER AIR...DON`T THINK
CLOUDS WILL BECOME PERSISTENT AT KPUB. THIS WILL POSE CHALLENGES FOR
MAX TEMPS TODAY THOUGH...AS NORTHWEST WINDS AND SLIGHTLY WARMER
TEMPERATURES ACROSS THE MTS AND LOWER EASTERN SLOPES WILL TRANSITION
INTO THE COLDER AIRMASS BANKED INTO THE SOUTHEAST PLAINS. GETTING
THIS GRADIENT IN THE CORRECT POSITION WILL BE KEY TO FORECASTING MAX
TEMPERATURES TODAY...AND WITH EASTERLY SFC WINDS EXPECTED AT
KPUB...KEPT TEMPERATURES BELOW GUIDANCE FOR THE LOWER ARKANSAS RIVER
VALLEY FROM KPUB EASTWARD. WOULDN`T BE SURPRISED TO SEE HIGHS ONLY
IN THE 20S ALONG THE KS BORDER THIS AFTERNOON. HAVE ALSO INCLUDED
SOME FOG IN THE GRIDS FOR THE FAR EASTERN PLAINS...AND WILL HAVE TO
WATCH FOR THE POTENTIAL FOR IT TO BECOME DENSE...OR EVEN PRODUCE
SOME SPOTTY FREEZING DRIZZLE LATER THIS MORNING AS LOWER ATMOS
SATURATES. ANY VIS RESTRICTIONS SHOULD BREAK BY NOON...AND MODELS
SUGGEST STRATUS WILL BREAK UP DURING THE MID AFTERNOON FOR FAR
EASTERN AREAS.
TONIGHT...LEE TROF KICKS EASTWARD AND ARCTIC AIRMASS RECEDES
EASTWARD ACROSS THE PLAINS. SHOULD BE A QUICK DROP IN TEMPERATURES
THIS EVENING THOUGH...ESPECIALLY FOR THE EASTERN PLAINS.
MEANWHILE...WESTERLY WINDS ACROSS THE MTS/I-25 CORRIDOR SHOULD KEEP
MIN TEMPS IN THE MID-UPPER 20S IN THE USUAL BREEZY SPOTS LIKE CANON
CITY AND WALSENBURG. TRICKY FORECAST AGAIN FOR KALS. GUIDANCE HAS
BEEN PERSISTENTLY UNDERDOING THE AMOUNT OF RADIATIONAL COOLING AT
NIGHT OVERTOP SNOWPACK ACROSS THE SAN LUIS VALLEY...ESPECIALLY IF
CLOUDS ARE LACKING. THERE WILL BE ANOTHER BOUT OF HIGH CLOUDS
SPILLING IN OVERTOP THE UPPER RIDGE AXIS TONIGHT...BUT APPEARS THAT
BETTER MOISTURE WILL STAY OFF TO THE NORTH AND WEST...SO HAVE
UNDERCUT GUIDANCE FOR MIN TEMPS FOR THE SAN LUIS VALLEY AGAIN
TONIGHT. WILL HAVE TO WATCH FOR THE EVER PRESENT THREAT FOR PATCHY
DENSE FOG ACROSS THE SAN LUIS VALLEY TONIGHT AS WELL. -KT
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 423 AM MST SUN JAN 17 2016
...SEVERAL DISTURBANCES TO BRING SNOW TO THE MOUNTAINS...
MONDAY THROUGH WEDNESDAY...MODELS HAVE BEEN VERY CONSISTENT IN
KEEPING AN ACTIVE UPPER PATTERN IN PLACE FOR THE REGION...AND
ESPECIALLY FOR THE HIGHER ELEVATIONS WITH A FOCUS ON THE CONTDVD. ONE
DISTURBANCE WILL CROSS MONDAY NIGHT INTO TUESDAY...AND THE SECOND
WILL CROSS ON WEDNESDAY. GIVEN THE GENERAL NW FLOW ALOFT...THE
CONTDVD WILL RECEIVE THE BRUNT OF THE NEW SNOWFALL...AND
PARTICULARLY THE CENTRAL MTS. EACH EVENT SHOULD BRING 1 TO 3 INCHES
OF NEW SNOW TO THE HIGHER TERRAIN OF LAKE AND CHAFFEE COUNTIES...AND
UP TO 2 INCHES FOR THE REMAINING MTS. MAX TEMPS EACH DAY ARE
EXPECTED TO CLIMB TO NEAR 50 F FOR THE PLAINS...AND INTO THE 30S TO
NEAR 40 F FOR THE HIGH VALLEYS.
THURSDAY THROUGH SATURDAY...A RIDGE OF HIGH PRESSURE BUILDS ACROSS
THE SOUTHWESTERN US...ALLOWING FOR DRY CONDITIONS ACROSS THE CWA FOR
THU AND FRI. MAX TEMPS ON THU SHOULD BE THE SAME AS EARLIER IN THE
WEEK...BUT FOR FRI AND SAT WILL WARM TO NEAR 60 F FOR THE
PLAINS...AND INTO THE MID 30S TO MID 40S FOR THE HIGH VALLEYS.
LATEST MODEL RUNS HINT AT ANOTHER UPPER WAVE CROSSING THE REGION FOR
SAT...BRINGING ISOLATED SNOW TO THE CONTDVD. HOWEVER...AT THIS TIME
THIS FEATURE LOOKS TO BE MORE OF A GLANCING BLOW TO THE
NORTH...WHICH WOULD KEEP SNOW AMOUNTS LIGHT WITH LITTLE EFFECT ON
TEMPS EAST OF THE MTS. MOORE
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 423 AM MST SUN JAN 17 2016
IFR TO LIFR CONDITIONS WITH -SN BLSN WILL CONTINUE ACROSS THE
CENTRAL MTS TODAY WITH WIDESPREAD MTN OBSCURATIONS EXPECTED ACROSS
THE SAWATCH AND MOSQUITO RANGES. SNOW WILL BE MORE ISOLATED TO
SCATTERED IN COVERAGE THIS MORNING OVER THE REMAINDER OF THE
MOUNTAINS WITH POCKETS OF MVFR TO IFR CONDITIONS. MEANWHILE...THE
TAF SITES WILL REMAIN DRY. WILL HAVE TO WATCH FOR THE POTENTIAL
FOR SHALLOW DENSE GROUND FOG AT KALS THIS MORNING...BUT WITH SOME
MID/HIGH CLOUD COVER AT TIMES OVER THE AREA SYSTEM...SUSPECT THAT
CONDITIONS WILL REMAIN MVFR-VFR. IFR TO LIFR STRATUS/FOG WILL
SPREAD EASTWARD INTO THE SOUTHEAST PLAINS THIS MORNING BEHIND A
SHALLOW ARCTIC COLD FRONT. STRATUS IS EXPECTED TO SPREAD INTO KLHX
BY MID MORNING. THERE IS A LOW POTENTIAL FOR A SCT LOW CLOUD LAYER
TO DEVELOP FOR AN HOUR OR TWO OVER KPUB BY LATE MORNING.
OTHERWISE...CLOUDS WILL SLOWLY DIMINISH FROM WEST TO EAST ACROSS
THE PLAINS THROUGH THE AFTERNOON WITH CONDITIONS REMAINING VFR AT
KCOS AND KPUB THROUGH TONIGHT. KALS MAY SEE A BETTER SHOT FOR SOME
IFR CONDITIONS LATE TONIGHT THROUGH MONDAY MORNING DUE TO GROUND
FOG. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ058-
060.
&&
$$
SHORT TERM...KT
LONG TERM...MOORE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS ALBANY NY
1001 AM EST SUN JAN 17 2016
.SYNOPSIS...
ANOTHER LOW PRESSURE SYSTEM WILL APPROACH FROM THE GREAT
LAKES REGION THIS AFTERNOON...AND WILL BRING MAINLY A LIGHT SNOWFALL
TO THE AREA TONIGHT. IN THE WAKE OF THIS SYSTEM...AN ARCTIC AIRMASS
WILL MOVE INTO THE REGION WITH LOWS DROPPING INTO THE SINGLE DIGITS
AND BELOW ZERO MONDAY NIGHT. LAKE EFFECT SNOWS WILL ALSO DEVELOP
DOWNWIND OF LAKE ONTARIO MONDAY THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1000 AM EST...THE VISIBLE SATELLITE PICTURE CONTINUES TO
HAVE CLOUDS INCREASE AHEAD OF THE CLIPPER LOW MOVING EAST OF LAKE
HURON AND GEORGIAN BAY. SOME ISOLD-SCT SNOW SHOWERS PERSIST OVER
THE TUG HILL PLATEAU/THE WRN DACKS. SOME LOW CHC POPS WERE
CONTINUED THERE LATE THIS MORNING. THE LATEST HRRR 3-KM/NAM12
TRENDS ARE FOR LIGHT SNOW TO MOVE INTO THE FCST AREA FROM THE W/SW
BTWN 21Z-00Z/MON. SOME SLIGHT RETOOLING OF THE POPS WAS DONE PRIOR
TO 00Z/MON. PRIOR TO THE WEAK ISENTROPIC LIFT WITH THE
CLIPPER...MOST OF THE AFTERNOON SHOULD BE DRY.
IT WILL BE MUCH COLDER TODAY THAN YESTERDAY WITH HIGHS RANGING
FROM THE MID 20S NORTHWEST TO MID 30S SOUTHEAST WHICH MEANS THE
TEMPERATURES WILL ONLY RISE A DEGREE OR TWO IN MOST AREAS FROM
OVERNIGHT LOWS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
A WINTER WEATHER ADVISORY FOR SNOW HAS BEEN ISSUED FOR TONIGHT FOR
NORTHERN HERKIMER AND HAMILTON COUNTIES.
A LAKE EFFECT SNOW WARNING HAS BEEN ISSUED FOR HERKIMER COUNTY
FOR MONDAY THROUGH TUESDAY.
THE CLIPPER TYPE SYSTEM WILL MOVE FROM THE EAST END OF LAKE
ONTARIO THIS EVENING TO THE GULF OF MAINE BY MONDAY MORNING.
AS A RESULT SNOW WILL OVERSPREAD THE FA THIS EVENING AND CONTINUE
THROUGH MUCH OF THE OVERNIGHT. SNOWFALL ACCUMULATIONS WILL
GENERALLY BE 1 TO 4 INCHES IN MOST AREAS WITH 3 TO 8 INCHES
ACROSS THE WESTERN ADIRONDACKS. LOWS TONIGHT WILL RANGE FROM THE
UPPER SINGLE DIGITS NORTHWEST TO AROUND 20 SOUTHEAST.
WITH THE PASSAGE OF THE SYSTEM`S ARCTIC BOUNDARY...THERE WILL BE A
TRANSITION TO LAKE EFFECT SNOWS. SIGNIFICANT LAKE EFFECT SNOW IS
EXPECTED ACROSS HERKIMER COUNTY WITH 6 TO 12 INCHES OF
ACCUMULATION BETWEEN MONDAY AND TUESDAY WITH THE GREATEST
ACCUMULATION ACROSS THE SOUTHERN PORTION OF NORTHERN HERKIMER
COUNTY AND SOUTHERN HERKIMER COUNTY WHERE THE TRAJECTORY OF THE
LAKE BAND OFF LAKE ONTARIO IS MOST PERSISTENT. ARCTIC AIR WILL
POUR INTO THE REGION AND IT WILL GET BITTERLY COLD MONDAY NIGHT
WITH WIND CHILL VALUES DOWN TO 20 BELOW OR COLDER ACROSS MUCH OF
THE WESTERN ADIRONDACKS. HAVE THIS MENTIONED IN OUR HAZARDOUS
WEATHER OUTLOOK. HIGHS ON MONDAY ARE EXPECTED TO RANGE FROM THE
TEENS NORTHWEST TO MID 20S SOUTHEAST. LOWS MONDAY NIGHT ARE
EXPECTED TO RANGE FROM THE 5 BELOW ZERO NORTHWEST TO 15 ABOVE ZERO
SOUTHEAST. HIGHS ON TUESDAY ARE EXPECTED TO RANGE FROM THE TEENS
NORTHWEST TO MID 20S SOUTHEAST.
THE LAKE EFFECT IS EXPECTED TO WIND DOWN BY TUESDAY NIGHT WITH
MOSTLY CLOUDY SKIES DURING THE EVENING GIVING WAY TO SOME BREAKS
IN THE CLOUDS OVERNIGHT. IT WILL CONTINUE TO BE COLD WITH LOWS IN
THE SINGLE DIGITS AND TEENS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE PERIOD WILL LARGELY BE DOMINATED BY SEASONABLY CHILLY
TEMPERATURES...AND BELOW NORMAL PRECIPITATION...UNTIL FRI-SAT.
THEN...THERE IS AT LEASE SOME POSSIBILITY OF A COASTAL STORM
AFFECTING PORTIONS OF THE REGION...ESPECIALLY SOUTHERN AREAS.
FOR WED-THU...SOME LINGERING LAKE EFFECT SNOW SHOWERS MAY GRAZE THE
FAR WESTERN ADIRONDACKS AND MOHAWK VALLEY...WITH GENERALLY DRY
CONDITIONS EXPECTED ELSEWHERE. A FAST MOVING...WEAKENING AND
MOISTURE STARVED UPPER LEVEL IMPULSE IS EXPECTED TO TRACK SOUTH OF
THE REGION ON THU. THIS MAY ALLOW FOR AN INCREASE IN HIGH/MID LEVEL
CLOUDS...ESP ACROSS SOUTHERN AREAS. OTHERWISE...MAX TEMPS SHOULD
REACH THE MID 20S TO LOWER 30S...EXCEPT FOR MAINLY TEENS ACROSS
HIGHER ELEVATIONS. OVERNIGHT MIN TEMPS SHOULD FALL INTO THE SINGLE
DIGITS AND TEENS.
FOR FRI-SAT...LATEST 00Z/17 DETERMINISTIC GLOBAL MODELS AND A SLIGHT
INCREASE IN 00Z/17 GEFS MEMBERS HAVE TRENDED MORE AMPLIFIED WITH
UPPER LEVEL ENERGY DIGGING INTO THE GULF COAST REGION...WITH MORE
PHASING BETWEEN SOUTHERN AND NORTHERN STREAM ENERGY COMPARED TO 24
HOURS AGO. THIS RESULTS IN A MORE NORTHERN TRACK OF A LOW PRESSURE
SYSTEM...EXPECTED TO TRANSLATE NORTHEAST FROM THE GULF COAST REGION
TO THE MID ATLANTIC COAST LATE FRI INTO SAT...WHILE DEEPENING. THE
00Z/17 DETERMINISTIC ECMWF CLOSES OFF THE MID/UPPER LEVEL LOW SOUTH
OF LONG ISLAND...WHILE THE GFS AND MOST 00Z/17 GEFS MEMBERS SUGGEST
A STRONG BUT MORE PROGRESSIVE SYSTEM. EITHER WAY...THE OVERALL
SIGNAL IS THAT SOME FORM OF A LOW PRESSURE SYSTEM MAY TRACK CLOSE
ENOUGH TO BRING SOME SNOW TO AT LEAST SOUTHERN AREAS FOR LATE FRI
INTO SAT. WHETHER THIS BECOMES A MORE WIDESPREAD AND HEAVIER
SNOWFALL SCENARIO REMAINS UNCERTAIN...ESP GIVEN THAT THIS IS THE
FIRST MODEL CYCLE WHERE THE ECMWF HAS JOINED OTHER GLOBAL MODELS
WITH A STRONGER/MORE NORTHERN TRACK...AND THAT 00Z/17 GEFS MEMBERS
STILL EXPRESS CONSIDERABLE UNCERTAINTY. FOR NOW...HAVE INDICATED CHC
POPS FOR CENTRAL AND SOUTHERN AREAS...AND SLIGHT CHC ACROSS THE
NORTH. THERMAL FIELDS APPEAR CONDUCIVE FOR SNOW AT THIS TIME...ESP
AS A SFC HIGH PASSES ACROSS EASTERN CANADA. EXPECT MAX TEMPS TO
REACH THE MID 20S TO LOWER 30S...WITH OVERNIGHT MINS MAINLY IN THE
TEENS.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
A DEVELOPING LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK
NORTHEAST...TOWARD AND OFF THE MID ATLANTIC COAST THIS AFTERNOON
AND TONIGHT. IN ADDITION...A WEAKER LOW PRESSURE SYSTEM WILL
APPROACH FROM THE GREAT LAKES REGION TONIGHT. THIS SECOND SYSTEM
IS EXPECTED TO BRING SOME LIGHT SNOW OR SNOW SHOWERS TO KGFL/KALB
AND KPSF OVERNIGHT.
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST THIS EVENING.
THE ONE EXCEPTION COULD BE SOME BRIEF PERIODS OF MVFR CIGS AT KPSF
THROUGH 15Z/SUN.
ALSO...A FEW PASSING FLURRIES WILL BE POSSIBLE THROUGH 14Z/SUN AT
KALB AND KPSF...BUT SHOULD NOT PRODUCE ANY RESTRICTIONS TO VSBY.
LATER THIS EVENING...LIGHT SNOW OR SNOW SHOWERS ASSOCIATED WITH
THE WEAK GREAT LAKES SYSTEM WILL DEVELOP BETWEEN 04Z-06Z/MON AT
KGFL/KALB AND KPSF. IFR VSBYS...AND MVFR CIGS ARE EXPECTED TO
DEVELOP DURING THIS TIME. THIS LIGHT SNOW IS EXPECTED TO DECREASE
IN AREAL COVERAGE BETWEEN 08Z-12Z/MON...WITH CONDITIONS IMPROVING
TO MVFR/VFR. HOWEVER...SCATTERED SNOW SHOWERS COULD STILL PRODUCE
BRIEF PERIODS OF IFR VSBYS THROUGH 12Z/MON. AT KPOU...MAINLY VFR
CONDITIONS ARE EXPECTED THROUGH 12Z/MON...ALTHOUGH PASSING SNOW
SHOWERS COULD CREATE BRIEF PERIODS OF MVFR/IFR VSBYS AFTER
07Z/MON.
WEST TO NORTHWEST WINDS AT 8-12 KT...AND SOME GUSTS UP TO 20 KT
WILL GRADUALLY DECREASE TO LESS THAN 5 KT BY MID MORNING. BY LATE
MORNING...WINDS WILL BE LIGHT...MAINLY FROM THE NORTHWEST TO
NORTH...AT 5-10 KT...ALTHOUGH MAY TREND INTO THE EAST/SOUTHEAST AT
TIMES AT KGFL DUE TO LOCAL TOPOGRAPHICAL EFFECTS. NORTHWEST TO
NORTH WINDS AT LESS THAN 5 KT ARE EXPECTED FOR SUNDAY EVENING.
WINDS WILL THEN BECOME WEST TO NORTHWEST AND INCREASE TO 8-12
KT...WITH GUSTS OF 20 KT OR STRONGER POSSIBLE AFTER 08Z/MON.
OUTLOOK...
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
COLDER AIR RETURNS TO THE HSA AND WILL PERSIST THROUGH THE
UPCOMING WEEK. PRECIPITATION TYPE WILL BE SNOW. ICE WILL FORM ON
BODIES OF WATER.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR NYZ032-033.
LAKE EFFECT SNOW WARNING FROM 6 AM MONDAY TO 6 PM EST TUESDAY
FOR NYZ032-038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/11/WASULA
NEAR TERM...11/WASULA
SHORT TERM...IAA/11
LONG TERM...KL
AVIATION...KL
HYDROLOGY...11
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
907 PM CST MON JAN 18 2016
.UPDATE...
ISSUED AT 900 PM CST MON JAN 18 2016
The strato-cumulus and flurries in the southeast counties has
nearly departed into Indiana as of 9 pm. The clouds in our western
counties are positioned on the north side of a surface high
pressure, centered in southern IL to eastern Arkansas. Those
clouds are not being handled well at all in the HRRR nor RAP.
Satellite trends show some dissipation on the outer edges of the
narrow band of clouds as it slowly drifts eastward. Will continue
with the trend that before sunrise, that band of clouds will
mostly dissipate as cirrus clouds stream into western IL.
Low temps tonight will be closely tied to how soon those low
clouds dissipate. We are currently forecasting temps to drop
another 7-9 degrees from current readings in our west and
southwest, but that would not occur if clouds linger as late as
sunrise. Will stay the course with low temps, assuming clearing,
and keep lows around 6-7F in our SW and S, and -1F to +1F from
Galesburg to Lacon.
Looking ahead, snowfall still looks on track to begin southwest of
Springfield late Tuesday afternoon, with the bulk of the snowfall
occurring between 6 pm and 3 am. Amounts should be mainly in the 1
to 3 inch range, with the higher amounts south of a line from
Springfield to Effingham. The wave looks progressive, with snow
ending before 6 am in all of our counties, including those
bordering Indiana.
Updates this evening were mainly to sky grids, and weather grids
for flurries in the SE. Updated forecast info is already
available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 248 PM CST MON JAN 18 2016
A robust diurnal CU-field developed across central Illinois this
afternoon, mainly along and south of the I-72 corridor. Meanwhile,
a persistent band of low clouds extending from Minnesota into west-
central Illinois tried to push eastward, but generally stayed west
of a Macomb to Jacksonville line. The diurnal clouds will rapidly
dissipate toward sunset: however, the band of clouds further west
will likely persist into the evening. Models have not been picking
up on these clouds at all, with the HRRR 1-hour forecast suggesting
clear skies. Based on satellite loops, think they will inch
eastward into the Illinois River Valley over the next couple of
hours before gradually dissipating later in the evening. Will need
to monitor satellite trends closely to see if they spread further or
persist longer. At this time, will only bring them to a Galesburg
to just west of Springfield line this evening. Elsewhere, skies
will remain mostly clear through the night. Overnight low
temperatures will be in the single digits above zero across most of
the area, but will likely drop a couple degrees below zero across
the far north around Galesburg and Lacon.
.LONG TERM...(Tuesday through Monday)
ISSUED AT 248 PM CST MON JAN 18 2016
Arctic high pressure area will shift east of the CWA Tuesday and
allow a developing weather system in the southern plains to push
east and bring precip back into the area beginning late Tue
afternoon and continuing through Tue night, then ending Wed morning.
Temps thru the period will be cold enough for all snow, so question
will be how much snow and when will heaviest snow occur. The models
have trended slightly slower with the onset of the snow and this
makes sense given the current dryness of the lower layers and the
expected southeast winds tomorrow not bringing any moisture into the
area. So, believe snow will begin over most of the area after 6pm
tomorrow evening, though some light snow may begin in western IL
late tomorrow afternoon. Heaviest snowfall track should be from the
Jacksonville area to southeast IL, tomorrow evening through after
midnight. The main low will be tracking into AR late tomorrow night,
but system should be able to spread enough pcpn north into the area.
Models indicate good isentropic lift with this system with around
3g/kg of moisture being lifted. However, factors limiting the amount
of snowfall will be lack of low level moisture initially, system
will be weakening as it moves east, and system will be moving
through quickly. So snowfall thinking is 3-4 inches in western IL
will be the highest, decreasing to around 3 inches in the southeast,
and 2 to 2.5 inches along I-74. This matches up well with other
offices and thinking of the WWD graphics. Snow will continue into
Wed morning,but only in the east and southeastern parts of the CWA.
1/2 inch will still be possible in the Lawrenceville area before
ending by noon. Advisory will be likely in some part of the CWA, but
given most of the snow will be third period and still some
uncertainty on strength of system, will let overnight shift make
final decision on location of advisory.
A period of dry weather is then expected Wed night through Thursday
as this system pushes east and then next system moves out of the
plains toward the area. All models have finally come to some
agreement on the track of this next system and it appears that most
of the pcpn with it will be south of the CWA. Current forecasts show
that a chance of snow is possible in southeast IL Thur night only.
Otherwise, dry weather can be expected from Fri into Sunday. Then
Sunday night and Monday, models show a clipper system moving across
the northern third of the state. This will bring another shot of
pcpn to the northern/northeaster/and eastern parts of the CWA. P-
type will likely be snow, but with temps being above freezing during
the daytime periods, rain, or a mix of rain and snow is not out of
the question.
Temps will remain cold through Fri night given the continued Arctic
air over the area through tomorrow and then the clouds and pcpn
expected tomorrow night through Wed, and then again being north of
the Thur night/Fri weather system. Over the weekend the pattern will
become somewhat zonal and this should allow temps to warm back up to
normal or just above normal for Sun and Mon.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 600 PM CST MON JAN 18 2016
Diurnal MVFR clouds have begun to dissipate across east-central
and southeast Illinois late this afternoon, while VFR clouds
progress into far western Illinois. CMI remains the only TAF site
with an MVFR ceiling, but clouds should become SCT by 01z. Have
included VFR ceilings at PIA and SPI to account for the elongated
band of clouds that will likely linger across western Illinois for
much of the evening, based on their persistence and direction of
movement on satellite over the last 6 hours. After midnight,
models show the low VFR clouds should also dissipate for the most
part as west winds become light and variable by sunrise.
Mid and high clouds from the next system will begin overspreading
our western counties by mid-afternoon. Precipitation should
generally hold off until after the end of this TAF period. Have
included a -sn at 23z at SPI, but the bulk of the snowfall should
occur Tuesday night, as southeast winds develop.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
603 PM CST MON JAN 18 2016
.SHORT TERM...(Tonight)
ISSUED AT 248 PM CST MON JAN 18 2016
A robust diurnal CU-field developed across central Illinois this
afternoon, mainly along and south of the I-72 corridor. Meanwhile,
a persistent band of low clouds extending from Minnesota into west-
central Illinois tried to push eastward, but generally stayed west
of a Macomb to Jacksonville line. The diurnal clouds will rapidly
dissipate toward sunset: however, the band of clouds further west
will likely persist into the evening. Models have not been picking
up on these clouds at all, with the HRRR 1-hour forecast suggesting
clear skies. Based on satellite loops, think they will inch
eastward into the Illinois River Valley over the next couple of
hours before gradually dissipating later in the evening. Will need
to monitor satellite trends closely to see if they spread further or
persist longer. At this time, will only bring them to a Galesburg
to just west of Springfield line this evening. Elsewhere, skies
will remain mostly clear through the night. Overnight low
temperatures will be in the single digits above zero across most of
the area, but will likely drop a couple degrees below zero across
the far north around Galesburg and Lacon.
.LONG TERM...(Tuesday through Monday)
ISSUED AT 248 PM CST MON JAN 18 2016
Arctic high pressure area will shift east of the CWA Tuesday and
allow a developing weather system in the southern plains to push
east and bring precip back into the area beginning late Tue
afternoon and continuing through Tue night, then ending Wed morning.
Temps thru the period will be cold enough for all snow, so question
will be how much snow and when will heaviest snow occur. The models
have trended slightly slower with the onset of the snow and this
makes sense given the current dryness of the lower layers and the
expected southeast winds tomorrow not bringing any moisture into the
area. So, believe snow will begin over most of the area after 6pm
tomorrow evening, though some light snow may begin in western IL
late tomorrow afternoon. Heaviest snowfall track should be from the
Jacksonville area to southeast IL, tomorrow evening through after
midnight. The main low will be tracking into AR late tomorrow night,
but system should be able to spread enough pcpn north into the area.
Models indicate good isentropic lift with this system with around
3g/kg of moisture being lifted. However, factors limiting the amount
of snowfall will be lack of low level moisture initially, system
will be weakening as it moves east, and system will be moving
through quickly. So snowfall thinking is 3-4 inches in western IL
will be the highest, decreasing to around 3 inches in the southeast,
and 2 to 2.5 inches along I-74. This matches up well with other
offices and thinking of the WWD graphics. Snow will continue into
Wed morning,but only in the east and southeastern parts of the CWA.
1/2 inch will still be possible in the Lawrenceville area before
ending by noon. Advisory will be likely in some part of the CWA, but
given most of the snow will be third period and still some
uncertainty on strength of system, will let overnight shift make
final decision on location of advisory.
A period of dry weather is then expected Wed night through Thursday
as this system pushes east and then next system moves out of the
plains toward the area. All models have finally come to some
agreement on the track of this next system and it appears that most
of the pcpn with it will be south of the CWA. Current forecasts show
that a chance of snow is possible in southeast IL Thur night only.
Otherwise, dry weather can be expected from Fri into Sunday. Then
Sunday night and Monday, models show a clipper system moving across
the northern third of the state. This will bring another shot of
pcpn to the northern/northeaster/and eastern parts of the CWA. P-
type will likely be snow, but with temps being above freezing during
the daytime periods, rain, or a mix of rain and snow is not out of
the question.
Temps will remain cold through Fri night given the continued Arctic
air over the area through tomorrow and then the clouds and pcpn
expected tomorrow night through Wed, and then again being north of
the Thur night/Fri weather system. Over the weekend the pattern will
become somewhat zonal and this should allow temps to warm back up to
normal or just above normal for Sun and Mon.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 600 PM CST MON JAN 18 2016
Diurnal MVFR clouds have begun to dissipate across east-central
and southeast Illinois late this afternoon, while VFR clouds
progress into far western Illinois. CMI remains the only TAF site
with an MVFR ceiling, but clouds should become SCT by 01z. Have
included VFR ceilings at PIA and SPI to account for the elongated
band of clouds that will likely linger across western Illinois for
much of the evening, based on their persistence and direction of
movement on satellite over the last 6 hours. After midnight,
models show the low VFR clouds should also dissipate for the most
part as west winds become light and variable by sunrise.
Mid and high clouds from the next system will begin overspreading
our western counties by mid-afternoon. Precipitation should
generally hold off until after the end of this TAF period. Have
included a -sn at 23z at SPI, but the bulk of the snowfall should
occur Tuesday night, as southeast winds develop.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
331 AM CST SUN JAN 17 2016
.SHORT TERM...(Today)
ISSUED AT 331 AM CST SUN JAN 17 2016
Arctic high pressure will continue to slowly build into central and
southeast Illinois today. Some bands of light snow should continue
to accompany the leading edge of the very cold air this morning, but
it is not expected to amount to more than a dusting.
The most notable weather element today will be the cold condtions.
Temperatures at 3 AM range from the single digits in the far
northern portion of the forecast area, to the lower 20s along and
south of I-70. Temperatures are well below zero not too far upstream
across Iowa. Colder air will continue to spill across the area today
on persistent northwest winds. Do not expect much temperature
recovery today across the northern portion of the forecast area
despite developing sunshine by afternoon. Meanwhile, the "milder"
temperatures across the southern portion of the forecast area should
continue to fall. Wind Chill values will stay near advisory levels
across far northern portion of the area this morning, and will keep
Wind Chill Advisory in place there. Further south, where advisory
criteria will not be met, it will still be a very chilly day.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 331 AM CST SUN JAN 17 2016
Another wind chill advisory will be issued for central IL north of
I-70 tonight and Monday morning, with wind chills lowering to 15-25F
below zero during this evening and continue into late Monday
morning. Lows tonight to range from around 5F below zero northern
CWA to 0-5F above in southeast IL. Another frigid day Monday despite
ample sunshine with highs 10-15F. NW winds 10-15 mph and gusts to 20
mph prevail tonight and Monday. Lows Monday night range from zero to
7 above zero, and lighter winds to keep wind chills from getting as
cold, with northern areas reaching near 10 below wind chills. Highs
Tue reach 20-25F with increasing clouds.
Arctic airmass due to 1034 mb Canadian high pressure dropping
southward into the Northern Plains and to move into the MS river
valley Monday night, and into the OH/TN river valleys Tue. This to
bring the coldest air of the season to central and southeast IL. Dry
conditions expected across the area from tonight through much of
Tuesday, though a slight chance of light snow west of a Canton to
Springfield line by late Tue afternoon.
A stronger disturbance than this mornings will track into the
central plains Tue and into the MS river valley Tue night, and then
into the OH river valley Wed. Models have trended a bit higher with
snowfall amounts with 2-3 inches Tue night into Wed morning versus 1-
2 inches with yesterdays runs. Highest amounts are sw of I-74. May
evenually need a winter weather advisory for snow if this trend
continues. Any mixed precipitation should stay well south of I-64
over far southern IL with this system.
00Z models continue to struggle with southern stream storm system
late this week. ECMWF model continues to keep qpf south of central
and southeast IL Thu/Fri with surface low moving into the TN river
valley Thu night. More aggressive GEM models brings qpf across IL
during the day Thu and then diminishes from the west during day Fri
with surface low moving up the Ohio river. GFS models is inbetween
with qpf into southeast IL from I-70 south from Thu afternoon into
early Friday. Will stay close to ensemble concensus with keeping 20-
30% chances of light snow from Thu afternoon through Fri morning
with highest pops in southeast IL and IL river valley/nw IL drier.
Mixed precipititation could get into southern counties if pcpn gets
this far north. Temps to gradually modify late this week into next
weekend as highs reach the mid 30s to lower 40s next weekend as
upper level ridge builds into the area by Saturday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1146 PM CST SAT JAN 16 2016
Light snow/flurries are occurring along the arctic cold front as
it pushes southeast across central IL. The relatively dry air
below the cloud layer is reducing the potential for measurable
snow. Radar trends show that the flurries will likely linger until
a shortwave moves across Illinois after midnight. HRRR and RAP are
downplaying the snowfall coverage, as are the NAM and GFS. Radar
loops show precip steadily approaching, so will keep very light
snow in the TAFs for the remainder of the night, but overall
impact will be minimal due to limited snow accumulation if any.
Will keep all TAFs only as low as MVFR clouds, as upstream IFR
conditions seem to be maintaining a path to the SW of our
counties. Snowfall chances could linger through the morning hours,
but all precip should end by midday as the very dry airmass
arrives on brisk NW winds.
Winds will shift from W to NW after the passage of the arctic
front, with speeds increasing later tonight as pressure rises ramp
up in the wake of the front. By 12z, winds could already be
gusting to 25kt in PIA, with those gusts advancing to CMI/DEC by
14z.
Forecast soundings show clearing skies progressing into the area from
the northwest Sunday afternoon, with clear conditions at all TAF
sites by mid-afternoon.
&&
.ILX Watches/Warnings/Advisories...
Wind Chill Advisory from 6 PM this evening to 11 AM CST Monday
for ILZ027>031-036>038-040>057-061.
Wind Chill Advisory until 11 AM CST this morning for ILZ027>031-
036-037.
&&
$$
SHORT TERM...BAK
LONG TERM...07
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1146 PM CST SAT JAN 16 2016
.UPDATE...
ISSUED AT 910 PM CST SAT JAN 16 2016
The arctic front is progressing southeast across IL, with a band
of flurries developing along the front northwest of a line from
Rushville to Lincoln to Bloomington at 03z/9pm. The 00z ILX
sounding showed some dry air to overcome, so the radar returns may
be mostly virga at this point. Have added flurries to follow the
band of radar returns as it progresses farther southeast. The
initial period of snow is expected to dissipate according to HRRR
and RAP output, with another wave of snow developing with an upper
level wave moving east along the front. High res models show that
wave of snow will be mainly in our western counties, with somewhat
limited eastward extent. Have delayed the coverage of chance PoPs
with the second wave, and lowered the extent of the 50 pct PoPs.
A dusting of snow still could develop in a few locations, but the
increasing wind will likely push most of that snow off area roads.
Updates this evening were mainly needed for the weather and PoP
grids. Temps and winds look on track, so will not make any
adjustments to the wind chill advisory for our NW
counties...mainly NW of the IL river. Updated forecast info is
already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 255 PM CST SAT JAN 16 2016
A surge of bitterly cold air is on the way later tonight...as a
1033mb high over Saskatchewan builds southward into the central U.S.
An area of lift ahead of the colder airmass associated with a weak
mid-level short-wave is spreading across eastern Nebraska into
western/central Iowa, where light snow is currently falling. Models
show this lift gradually developing eastward into central Illinois
later this evening into the overnight hours. Airmass will initially
be quite dry at mid/low-levels, so it will take awhile for any
precip to develop. Based on time-height cross-sections, it appears
strongest lift and deepest column moisture will only be present for
a 3-4 hour window from just after midnight into Sunday morning. Have
therefore kept conditions dry through the evening, with high chance
PoPs for light snow developing along/north of the I-72 corridor
after midnight. Accumulations will be minor due to the light and
transient nature of the precip, with amounts of one half inch or
less anticipated. Main weather story will be the breezy and colder
conditions, as overnight lows drop into the single digits and teens.
Corresponding wind-chill values will drop below zero along/north of
I-72 by dawn Sunday...with the coldest readings of near 15 below
zero across the NW KILX CWA. Have issued a Wind Chill Advisory
along and north of a Lewistown to El Paso line...and a Special
Weather Statement highlighting the cold further southeast to I-72.
.LONG TERM...(Sunday through Saturday)
ISSUED AT 255 PM CST SAT JAN 16 2016
A weak wave will continue to move across the area Sunday morning,
with light amounts of snowfall expected. Due to the weak lift and
limited moisture, will continue with just chance pops for the
morning only and then have dry weather with skies clearing out in
the afternoon. This dry weather will continue thru the rest of the
weekend holiday and into Monday night. Then clouds will begin to
increase on Tuesday as the next weather system approaches from the
west. The mid range models are in very good agreement with this next
system with snow expected Tue afternoon through Wed morning/early
afternoon. Based on timing of the low pressure area the best chance
of snow will be Tuesday night and in southwest IL. Though this
system is stronger than the one coming in tonight and it will have
more moisture to work with, it doesn`t appear that much snow will
occur with this system. A couple of inches will be possible, but
over a period of 24-30hrs. Another weather system is possible on the
heals of the system that will be leaving the area Wed. However,
models showing disagreement with track of low pressure area, which
effects the location and timing of pcpn. ECMWF takes the sfc low
well south, into the Gulf Coastal area and moves it east across FL.
The GFS and Canadian are in agreement with each other and bring the
sfc low out of OK, through southern MO, and into southern IL. This
track would spread more pcpn/snow across the CWA for the later part
of the week. So will continue with a blend of models with this end
of week system and have chance pops only Thur night across areas
east of the IL river, only. Will have just snow in the forecast for
now, but this looks like an over-running situation, so a wintry mix
of pcpn is not out of the question. New forecasts early next week
should give us a better idea on location and pcpn type.
Temps will be very cold tonight and tomorrow night. Wind chill
advisory for tonight will continue til tomorrow late morning in the
northwest. However, with temps expected to be even colder tomorrow
night/Mon morning, another advisory is likely and will probably
cover the entire CWA. Temps will gradually warm next week and could
reach to normal by next Sat.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1146 PM CST SAT JAN 16 2016
Light snow/flurries are occurring along the arctic cold front as
it pushes southeast across central IL. The relatively dry air
below the cloud layer is reducing the potential for measurable
snow. Radar trends show that the flurries will likely linger until
a shortwave moves across Illinois after midnight. HRRR and RAP are
downplaying the snowfall coverage, as are the NAM and GFS. Radar
loops show precip steadily approaching, so will keep very light
snow in the TAFs for the remainder of the night, but overall
impact will be minimal due to limited snow accumulation if any.
Will keep all TAFs only as low as MVFR clouds, as upstream IFR
conditions seem to be maintaining a path to the SW of our
counties. Snowfall chances could linger through the morning hours,
but all precip should end by midday as the very dry airmass
arrives on brisk NW winds.
Winds will shift from W to NW after the passage of the arctic
front, with speeds increasing later tonight as pressure rises ramp
up in the wake of the front. By 12z, winds could already be
gusting to 25kt in PIA, with those gusts advancing to CMI/DEC by
14z.
Forecast soundings show clearing skies progressing into the area from
the northwest Sunday afternoon, with clear conditions at all TAF
sites by mid-afternoon.
&&
.ILX Watches/Warnings/Advisories...
Wind Chill Advisory from 3 AM to 11 AM CST Sunday for ILZ027>031-
036-037.
&&
$$
UPDATE...Shimon
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS WICHITA KS
339 PM CST SUN JAN 17 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 335 PM CST SUN JAN 17 2016
ELONGATED BAND OF -SHSN PERSISTING ACROSS FORECAST AREA LATE THIS
AFTERNOON...DUE TO PERSISTENT...MOIST...ISENTROPIC UPGLIDE 285-290K
THETA SURFACES...ENHANCED BY WEAK JET STREAK APPARENT IN WATER VAPOR
IMAGERY. 06UTC NAM PROVIDED SOME HINT...AND 17UTC RAP APPEARS TO BE
BEST PREDICTIVE VALUE AT PRESENT. EXPECT POTENTIAL FOR SNOW SHOWERS
TO DIMINISH BY EARLY TO MID-EVENING.
AFTER SNOW CHANCES DIMINISH...MAY FORECAST CONCERN WILL BE OVERNIGHT
TEMPERATURES. CLOUD COVER WILL PERSIST MOST OF THE NIGHT...WHICH
WILL HELP COUNTER RADIATIVE AND ADVECTION COOLING. DUE TO SNOW PACK
ACROSS NORTHEAST KANSAS...TRENDED SLIGHTLY COLDER THAN GUIDANCE
FLINT HILLS INTO NORTH CENTRAL KANSAS DUE TO ADVECTIVE PROCESSES.
TEMPERATURES WILL BE ABLE TO REBOUND ABOVE FREEZING CENTRAL AND
SOUTH CENTRAL KANSAS ON MONDAY...DUE TO RETURN SOUTHERLY FLOW.
SOUTHEAST AND NORTHEAST KANSAS WILL REMAIN UNDER GRIP OF
DEEPER...COLDER AIRMASS...THUS MAX TEMPS ONLY EXPECTED TO REACH MID
TO UPPER 20S. TEMPERATURES MONDAY INTO TUESDAY WILL MODERATE DUE TO
SOUTHERLY FLOW...BUT THEN ANOTHER FAST MOVING SYSTEM WILL DIVE
ACROSS THE PLAINS BRINGING ANOTHER SHOT OF COLDER AIR AND POSSIBLY A
CHANCE OF LIGHT SNOW OR RAIN/SNOW MIX TUESDAY AFTERNOON AND TUESDAY
NIGHT.
ANOTHER FAST MOVING SHORT WAVE DIVES INTO SOUTHERN PLAINS WEDNESDAY
NIGHT INTO TUESDAY. FORECAST MODELS DEEPENED/INTENSIFIED THIS OPEN
WAVE THE PAST FEW RUNS. DETERMINISTIC MODELS ARE SHOWING
VARIABILITY IN TRACK AND DEPTH OF H5/SURFACE LOW...WHICH WILL HAVE
IMPACT ON PRECIPITATION TYPE. GFS IS MORE BULLISH WITH PRECIPITATION
AND EVOLVES WARM AND MOIST CONVEYOR BELT MORE SO THAN ECWMF. GFS
ENSEMBLES ALL OVER THE PLACE WITH H5 EVOLUTION AND EC MEAN ENSEMBLE
LOOKS RATHER ANEMIC. GIVEN UNCERTAINTY...KEPT PRECIPITATION CHANCES
ON THE LOW SIDE AND DID NOT GET TOO SPECIFIC WITH PRECIPITATION
TYPE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 335 PM CST SUN JAN 17 2016
EXTENDED PART OF THE FORECAST PERIOD INDICATES A WARMING AND DRY
TREND AS H5 RIDGING BUILDS OVER INTERMOUNTAIN WEST FRIDAY AND
SATURDAY.
SF
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1129 AM CST SUN JAN 17 2016
LOW CLOUDS WILL CONTINUE TO PUSH SOUTHWARD INTO OKLAHOMA
TODAY...AS DRIER LOW LEVEL AIR SPREADS ACROSS THE REGION. MID
LEVEL CLOUDS WILL LINGER ACROSS THE AREA INTO TONIGHT WITH VFR
CONDITIONS EXPECTED.
JAKUB
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 9 31 23 38 / 30 0 0 30
HUTCHINSON 8 32 24 34 / 30 0 0 30
NEWTON 6 30 22 34 / 50 0 0 30
ELDORADO 10 28 22 37 / 50 0 0 40
WINFIELD-KWLD 9 31 23 42 / 20 0 0 30
RUSSELL 8 35 23 32 / 20 0 10 30
GREAT BEND 8 36 24 33 / 20 0 10 20
SALINA 6 31 22 31 / 30 0 10 40
MCPHERSON 8 31 23 33 / 50 0 10 30
COFFEYVILLE 10 29 23 45 / 30 10 0 40
CHANUTE 6 27 20 42 / 40 0 10 40
IOLA 5 26 20 41 / 30 0 0 50
PARSONS-KPPF 6 28 21 43 / 30 0 0 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
332 PM CST SUN JAN 17 2016
.SHORT TERM...(THIS EVENING THROUGH Monday)
ISSUED AT 328 PM CST SUN JAN 17 2016
In the short term the forecast will revolve around temperature
trends, as well as clouds and any flurried or fog. The HRRR seemed
to have a better trend for hourly temperatures this afternoon
and was generally followed. The surface high will become
reinforced across the northern plains and extending into the
southern plains. Temperatures will likely be as cold or colder
tonight, albeit without the wind that was present Sunday morning.
Again freezing fog canbe an issue again early Monday morning,
reducing visibility in some areas. A quick return to southerly
surface winds and increase in insolation by midday Monday, aiding
to a bump in temperatures wellabove freezing on the higher
elevation western counties. Cold highs in the low 30s are all
that can be expected on the lower plains(Hays to medicine Lodge).
.LONG TERM...(Monday NIGHT THROUGH Sunday)
ISSUED AT 328 PM CST SUN JAN 17 2016
Models indicate a shortwave moving through the central plains
aroundTuesday, which is somewhat weak and moisture starved. Any
snow mightbe minimal with this fast moving feature. A reasonable
moderation inmorning lows is likely by this time as the very cold
air associatedwith the surface high should be moving east of the
region. Asimilar, 2nd wave is possible about 48 hours later, with
aalight chance for snow once again.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Monday AFTERNOON)
ISSUED AT 1223 PM CST SUN JAN 17 2016
Cold surface high pressure will become reinforced from the Northern
Plains to the Missouri valley. Northeast surface winds will perisist
as a result. Widespread stratus will continue to result due to the
upslope flow pattern, with ceilings improving through the
afternoon, but likley deteriorating once again this evening and
overnight.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 11 41 26 41 / 0 0 10 10
GCK 12 47 25 44 / 0 0 10 10
EHA 16 54 29 49 / 0 0 0 10
LBL 14 48 28 47 / 0 0 10 10
HYS 7 34 23 37 / 10 0 10 10
P28 9 34 27 39 / 0 0 10 10
&&
.DDC Watches/Warnings/Advisories...NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS JACKSON KY
1255 AM EST SUN JAN 17 2016
.UPDATE...
ISSUED AT 1256 AM EST SUN JAN 17 2016
UPDATED TO KEEP TEMPERATURES MORE STEADY THROUGH THE REST OF THE
NIGHT AS WE SHOULD SEE VERY LITTLE FALL FROM CURRENT READINGS.
ALSO...STILL SEEING SOME RETURNS ON JKL RADAR TO SUPPORT KEEPING
THE MENTION OF DRIZZLE/FLURRIES IN THE FORECAST THROUGH THE REST
OF THE NIGHT...BASICALLY ACROSS FAR EASTERN AND SOUTHEAST
KENTUCKY. HRRR AND OTHER SHORT TERM MODEL GUIDANCE CONTINUES TO
BRING IN SOME LIGHT SNOW ACROSS FAR SOUTHEAST KENTUCKY LATE
TONIGHT. LOOKS LIKE THERE WILL ONLY BE A FEW HOUR WINDOW RIGHT
AROUND DAYBREAK FOR SNOWFALL TO OCCUR. WITH THIS IN MIND...DID
TWEAK SNOWFALL AMOUNTS TO MATCH THE EXPECTED QPF WHICH SHOULD
REMAIN VERY LIGHT. THUS...SNOWFALL WILL REMAIN UNDER A HALF INCH.
UPDATE ISSUED AT 1052 PM EST SAT JAN 16 2016
THE LIGHT WINTRY PRECIP HAS GENERALLY BECOME MORE CELLULAR OR
SHOWERY OVER THE PAST FEW HOURS. CLOUD TOP TEMPS SUGGEST THAT THIS
IS EITHER FLURRIES OR LIGHT SNOW SHOWERS FOR THE MOST PART...BUT
SOME FREEZING DRIZZLE STILL CANNOT BE RULED OUT SINCE THE MOISTURE
IS SOMEWHAT SHALLOW.
THE 0Z NAM AND 0Z GFS RUNS HAVE LED TO SOME INCREASED CONFIDENCE
THAT THE VA BORDER COUNTIES...ESPECIALLY FROM HARLAN NORTHEAST TO
PIKE COUNTY COULD PICK UP A HALF OF AN INCH OR SO NEAR THE
VIRGINIA BORDER LATE TONIGHT INTO EARLY ON SUNDAY. THIS AREA
APPEARS DESTINED TO BE CLIPPED BY SOME PRECIP ON THE NW EDGE OF
LOW PRESSURE PASSING TO THE SOUTHEAST OF THE AREA.
OTHERWISE...NO SIGNIFICANT CHANGES WERE MADE AT THIS TIME.
UPDATE ISSUED AT 705 PM EST SAT JAN 16 2016
UPSLOPE FLOW IS CURRENTLY PRESENT ACROSS THE AREA WITH RATHER
SHALLOW MOISTURE REMAINING UP TO NEAR 850 MB. RADAR SHOWS SOME
GENERALLY WEAK RETURNS FALLING AS EITHER VERY LIGHT SNOW OR
FLURRIES OR SOME DRIZZLE OR FREEZING DRIZZLE WHERE TEMPERATURES
ARE BELOW FREEZING. SOME LIGHT FREEZING DRIZZLE OCCURRED AT JKL
SINCE LATE AFTERNOON...BUT ONLY VERY LIGHT FLURRIES ARE FALLING AT
PRESENT. NEAR HAZARD IN PERRY COUNTY...WE RECENTLY HAD A PUBLIC
REPORT OF LIGHT SNOW WITH A DUSTING HAVING OCCURRED THERE
RECENTLY.
OVERALL...THE GRIDS HAVE BEEN ADJUSTED TO THE RECENT TRENDS IN
OBSERVATIONS AND TO ALLOW FOR FLURRIES...DRIZZLE OR FREEZING
DRIZZLE A BIT LATER INTO THE NIGHT AS MODELS HAVE THE MOISTURE
BECOMING MORE SHALLOW IN THE LOW LEVELS OVERNIGHT. CONFIDENCE IN
THE TYPE ANY LIGHT PRECIPITATION WILL TAKE IS A BIT LOW AT THIS
TIME. EITHER WAY...WITH SOME LINGERING MOISTURE ON THE PAVEMENT
IN SOME AREAS SOME BLACK ICE CANNOT BE RULED OUT OVERNIGHT. THE
HWO WAS UPDATED ACCORDINGLY AND AN SPS WAS ALSO ISSUED.
THE SECOND CONCERN IS THE POTENTIAL FOR SOME LIGHT SNOW LATE
TONIGHT AND EARLY ON SUN NEAR THE VA BORDER ON THE FAR NW FRINGE
OF A SFC LOW PASSING WELL TO THE SOUTHEAST OF THE AREA. THE 18Z
NAM AND RECENT RAP GUIDANCE KEEP THIS SOUTHEAST OF THE AREA LATE
TONIGHT OR HOLD OFF UNTIL 12Z AND AFTER AND ARE LIGHTER THAN THE
18Z GFS GUIDANCE. THE MOST RECENT HRRR RUN WOULD LEND SOME SUPPORT
FOR THE 18Z GFS GUIDANCE. WE HAVE OPTED TO INCREASE POPS TO THE
CHANCE RANGE LATE TONIGHT AND ALONG THE VA BORDER ACCORDINGLY
ALTHOUGH TRENDS WILL HAVE TO BE MONITORED FOR A POSSIBLE FURTHER
INCREASE IN POPS DURING THAT PERIOD.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 301 PM EST SAT JAN 16 2016
CURRENT CONDITIONS ACROSS THE REGION FEATURE AN AREA OF LOW LEVEL
MOISTURE OVER THE OH VALLEY REGION WITH SOME WEAK UPSLOPE
RESULTING IN A FEW AREAS OF DRIZZLE OR EVEN SNOW GRAINS. AS OF
1930Z...THE BULK OF THE LOW LEVEL MOISTURE HAS LIFTED OFF TO THE
EAST BUT SOME PATCHY DRIZZLE MAY LINGER INTO THIS EVENING. CLOUD
COVER WILL LINGER OVER THE AREA THROUGH THE OVERNIGHT PERIOD AND
INTO SUNDAY.
BY SUNDAY...A STRONG JET DIVES SOUTHEAST INTO THE GULF REGION AS A
STRONG SHORTWAVE DEVELOPS OVER THE NORTHERN GULF. THIS FEATURE
TRACK NORTHEAST ALONG THE COAST. SURFACE LOW DEVELOPMENT WRAPS
MOISTURE AROUND TO THE NORTH AND INTO THE APPALACHIAN MOUNTAINS.
FORTUNATELY...MODELS CONTINUE TO DISPLACE MOST OF THE LIFT AND
MOISTURE TO THE SOUTH AND EAST OF EASTERN KENTUCKY. THE TROUGH
DOES NUDGE NORTH ENOUGH TO BRING SOME MOISTURE INTO SOUTHEASTERN
KENTUCKY AND THUS WILL RESULT IN SOME SNOWFALL ACROSS THE AREA FOR
SUNDAY. AT THIS POINT...MODELS ARE BRINGING A FEW HUNDREDTHS INTO
THE SOUTHEAST BUT A FEW EARLIER RUNS OF THE GFS HAD UP TO THE
TENTH WHICH WOULD MEAN A BIT MORE SNOW BUT AT THIS POINT...THAT
RUN IS AN OUTLIER SO WILL GO WITH THE MORE CONSERVATIVE HI RES
SOLUTIONS. A DUSTING TO A FEW TENTHS CAN BE EXPECTED LATE TONIGHT
INTO SUNDAY.
ON THE HEALS OF THIS FEATURE WILL BE A RELATIVELY DRY ARCTIC
FRONT WITH SOME OF THE COLDEST AIR OF THE YEAR. MINUS 20 CELSIUS
850 TEMPS ARE POISED TO ENTER THE BLUEGRASS REGION SUNDAY EVENING
INTO SUNDAY NIGHT. IN FACT...AFTER 18Z SUNDAY...TEMPS WILL PLUMMET
THROUGH THE EVENING AND SUNDAY NIGHT INTO THE TEENS AND EVEN
SINGLE DIGITS IN THE BLUEGRASS COUNTIES BY MONDAY MORNING. THE
APPROACHING ARCTIC FRONT WILL BE ENOUGH TO KEEP A FEW FLURRIES
ACROSS THE AREA INTO SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 301 PM EST SAT JAN 16 2016
...COLDEST AIR OF THE SEASON ARRIVES MONDAY...
THE MODELS ARE IN QUITE GOOD AGREEMENT ALOFT AT THE START OF THE
EXTENDED PORTION OF THE FORECAST. THEY ALL DEPICT THE DEEP TROUGH
ROLLING EAST THROUGH ONTARIO ALLOWING THE LOW HEIGHTS TO REBOUND
OVER KENTUCKY. HOWEVER...THE FLOW WILL REMAIN OUT OF THE NORTHWEST
WITH ENERGY STILL TRACKING OVER THE AREA INTO TUESDAY. THE MODELS
START TO EXHIBIT SPREAD BY MIDWEEK AS THEY DISAGREE ON THE AMOUNT OF
MINOR RIDGING THAT WILL PUSH NORTH INTO KENTUCKY FROM AN
INCREASINGLY ACTIVE SOUTHERN STREAM. FOR WEDNESDAY THE GFS IS MOST
AGGRESSIVE WITH A TROUGH IT SWINGS INTO THE MID MISSISSIPPI VALLEY
WHILE THE CANADIAN AND ECMWF ARE FLATTER WITH THIS FEATURE.
AGREEMENT IS SLIGHTLY BETTER FOR THE TRAILING RIDGE PASSING OVER THE
STATE INTO THURSDAY AHEAD OF A DEEPENING TROUGH OVER WESTERN TEXAS.
AGAIN THE GFS IS THE STRONGER MODEL WITH THIS CLOSING IT OFF AS A
LOW OVER NORTHERN ARKANSAS EARLY FRIDAY WHILE THE CANADIAN MODEL
SERVES AS A COMPROMISE SCENARIO BETWEEN THE OTHERS. HOWEVER...BY
MIDDAY FRIDAY...THE ECMWF ALSO FORMS A CLOSED LOW OVER THE DEEP
SOUTH...BUT STILL SIGNIFICANTLY WEAKER THAN THE GFS. BOTH THE GFS
AND ECMWF RUN THIS TROUGH TO THE EAST COAST BY SATURDAY MORNING...
THOUGH THE LATTER IS SUBSTANTIALLY FURTHER SOUTH AND STILL WEAKER.
THEY REMAIN PROGRESSIVE AS WELL INTO THE WEEKEND SWEEPING THE SYSTEM
OFF SHORE ON SATURDAY...AS HEIGHTS REBOUND LOCALLY. GIVEN THE
TROUBLES THE MODELS ARE HAVING FROM MID WEEK ON...WILL FAVOR A
BLENDED SOLUTION WITH A SLIGHT LEAN TOWARD A MORE DYNAMIC VERSION
MIDWAY BETWEEN THE GFS AND ECMWF TRACKS.
SENSIBLE WEATHER WILL FEATURE SOME OF THE COLDEST AIR OF THE SEASON
FLOODING SOUTHEAST INTO KENTUCKY BY MONDAY MORNING WITH A COUPLE
COLD DAYS AND NIGHTS ON TAP. DO EXPECT THE COLDEST PERIOD TO BE
MONDAY NIGHT AS THE ARCTIC HIGH SETTLES OVERHEAD RESULTING IN MOSTLY
CLEAR SKIES. THE COLD AIR WILL MODERATE INTO THE LATTER PART OF THE
WEEK JUST AS THE NEXT ILL-DEFINED SFC WEATHER SYSTEM PASSES THROUGH
WITH A CHANCE OF RAIN OR SNOW. STILL CANNOT RULE OUT A LOSS OF ICE
ON THE BACKSIDE OF THIS FIRST WEAK SYSTEM LEADING TO A CONCERN FOR
FREEZING DRIZZLE EARLY THURSDAY - WILL CONTINUE TO HIGHLIGHT THIS IN
THE HWO. THE MORE INTERESTING SYSTEM WILL TAKE SHAPE EARLY FRIDAY TO
THE SOUTH AND SHOULD BRUSH THROUGH KENTUCKY WITH A CHANCE OF SNOW OR
RAIN INTO THE WEEKEND. IF IT GETS STRONGER THAN IS CURRENTLY PROGGED
THIS COULD BE A MORE SIGNIFICANT STORM WITH THE RIGHT TRACK TO BE
IMPACTFUL. WE WILL HAVE TO WATCH THIS ONE CLOSELY AS IT EVOLVES IN
THE MODELS THROUGH THE START OF THE NEW WEEK.
ADJUSTED THE GRIDS FROM THE CR INIT MAINLY TO ACCOUNT FOR DECENT
SMALL RIDGE TO VALLEY TEMPERATURE DIFFERENCES FOR MONDAY AND TUESDAY
NIGHT. ALSO TWEAKED THE POP GRIDS LATER IN THE PERIOD TO REFLECT A
FORECAST CLOSER TO THE LATEST ECMWF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1256 AM EST SUN JAN 17 2016
MAINLY MVFR CIGS SHOULD BE SEEN OVERNIGHT. WITH THE ONGOING
DRIZZLE AND FLURRIES...THERE HAVE BEEN A FEW INSTANCES OF CIGS
BRIEFLY DROPPING TO IFR. HOWEVER...FOR THE MOST PART...MVFR CIGS
SHOULD DOMINATE THROUGH THE REST OF THE NIGHT AND INTO SUNDAY
MORNING. CIGS SHOULD LIFT TO VFR BY EARLY AFTERNOON ON SUNDAY. AN
ARCTIC COLD FRONT WILL THEN DROP SOUTH SUNDAY AFTERNOON/EVENING
WITH NORTHWEST WINDS DEVELOPING AROUND 10 MPH WITH SOME GUSTS UP
TO 15 OR 20 MPH POSSIBLE. SOME FLURRIES OR A BRIEF SNOW SHOWER
WILL ALSO BE POSSIBLE WITH THE FRONT SUNDAY EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...SHALLENBERGER
LONG TERM...GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
938 PM EST MON JAN 18 2016
.UPDATE...
ISSUED AN UPDATE TO EXTEND THE LIGHT SNOW LIKELY WORDING ACROSS
THE INTERSTATE 96 CORRIDOR WELL THROUGH MIDNIGHT. LATEST RADAR
IMAGERY SUPPORTS THE DEVELOPMENT OF NEAR STEADY STATE LIGHT SNOW
BANDING INTO SOUTHEASTERN MICHIGAN. THE RADAR IMAGERY DOES SHOW
SNOW PRODUCTION AS HIGH AS THE 4000-6000 FT AGL LAYER...WHICH
CORRESPONDS EXACTLY TO STEEP LAPSE RATE POCKET JUST BELOW
INVERSION IN THE 00Z KDTX RAOB. THEREFORE...NOT EXPECTING
NOCTURNAL COOLING PROCESSES TO HAVE MUCH OF AN IMPACT...AND
INSTEAD WILL RELY ON CHANGE IN WIND DIRECTION. THIS IS SET TO
OCCUR WITH 1000-850 MB MEAN WIND VEERING NORTHWESTERLY IN THE
06-09Z TIMEFRAME TIED TO SHARP CYCLONIC VORTICITY FEATURE DIGGING
THROUGH. SURFACE OBSERVING SITES HAVE NOT BEEN CATCHING BULK OF
THE BAND...BUT LIMITED SURFACE SPOTTER REPORTS SUGGEST QUICK
DUSTING TYPE ACCUMULATIONS WITH RATHER MINOR DROPS IN VISIBILITY.
RATHER...THERE HAVE BEEN REPORTS OF VERY SLIPPERY CONDITIONS ALONG
THE AXIS OF LIGHT SNOWFALL...LIKELY A CONSEQUENCE OF THE COLD
TEMPERATURES AND LACK OF IMPACT FROM SALT/TREATMENT. THERE IS LOW
CONFIDENCE IN WHAT SORT OF ACCUMULATIONS WILL BE
POSSIBLE...PERHAPS UP TO AN INCH IN SOME LOCATIONS.
&&
.AVIATION...ISSUED 705 PM EST MON JAN 18 2016
A RAGGED STREAMER OF LAKE EFFECT SNOW SHOWERS HAS BECOME QUASI
STATIONARY ALONG AND NORTH OF THE INTERSTATE 96 CORRIDOR THIS
EVENING. CONDITIONS WITHIN THIS SNOW SHOWER ACTIVITY HAS BEEN
PRIMARILY MVFR BOTH IN CIG AND VSBY...BUT THE OCCASIONAL BRIEF IFR
VSBY HAS BEEN REPORTED AT TIMES. THE QUESTION MOVING FORWARD IS
HOW LONG THIS ACTIVITY WILL KEEP GOING. THE CELLULAR LOOK OF THE
CONVECTION OFFERED BY RADAR AND SATELLITE IMAGERY SUGGESTS A
DIURNAL/PEAK BOUNDARY LAYER GROWTH COMPONENT. THEREFORE...SUSPECT
THE SNOW SHOWER ACTIVITY WILL WEAKEN BY APPROXIMATELY 02Z WITH
THE MIXED LAYER SHRINKING. FLURRIES/LIGHT SNOW SHOWERS WILL REMAIN
PROBABLE THROUGH THE EVENING HOURS AND POSSIBLY AS LATE AS 06-08Z
WITH DEEPER COLUMN SUBSIDENCE SET TO IMPINGE DOWN ON SEMICH FROM
THE NORTH. MAINTAINED THE PRIOR FORECAST WITH NO HYDROMETEOR
MENTION AFTER 02Z WITH NO IMPACT EXPECTED.
FOR DTW...THE BAND OF LAKE EFFECT SNOW SHOWERS HAS REMAINED NORTH
OF THE TERMINAL THIS EVENING...AND THE EXPECTATION IS FOR THIS TO
CONTINUE. THE POTENTIAL FOR ADDITIONAL FLURRIES/LIGHT SNOW
SHOWERS WILL END BY 06-08Z. MVFR CIGS TO HOLD THROUGH MUCH OF
TONIGHT BEFORE SCATTERING AROUND DAWN. STEEP LOW LEVEL LAPSE RATES
AND DIURNAL HEATING SHOULD LEAD TO MVFR CIGS AGAIN BY 17Z.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING AOB 5000 FT THROUGH LATE TONIGHT.
* HIGH FOR SNOW AS PRECIPITATION TYPE.
&&
.PREV DISCUSSION...ISSUED 350 PM EST MON JAN 18 2016
DISCUSSION...
LAKE EFFECT SNOW SHOWERS WILL HOLD WITH SCATTERED TO NUMEROUS
COVERAGE AND LIGHT TO MODERATE INTENSITY FOR THE REST OF THE
AFTERNOON THROUGH MID EVENING. THE MOST RECENT RAP SOUNDINGS
INDICATE CONVECTIVE DEPTH SETTLING STEADILY BELOW 5000 FT BETWEEN
21Z AND 03Z BUT WITH NEARLY DRY ADIABATIC LAPSE RATE AND HIGH ICE
SUPERSATURATION WITHIN THE CLOUD LAYER FOR HEALTHY GROWTH OF
DENDRITES. THAT BEING SAID...SURFACE DEWPOINT AROUND -10F REPORTED
UPSTREAM OF LAKE MICHIGAN HAS TO BE CONSIDERED A LIMITING FACTOR FOR
LAKE INDUCED CONVECTIVE POTENTIAL THIS FAR EAST. ON THE POSITIVE
SIDE...MID TO LATE AFTERNOON SURFACE OBSERVATIONS ON THIS SIDE OF
THE LAKE CONTINUE TO ADVERTISE GUSTY WEST FLOW WITH A GREATER AMOUNT
OF CONVERGENCE DOWN WIND OF LAKE MICHIGAN THAN WOULD NORMALLY BE
EXPECTED IN WELL MIXED MID AFTERNOON CONDITIONS. THIS WILL KEEP
COVERAGE WITH BETTER INTENSITY FOCUSED GENERALLY ALONG AND SOUTH OF
THE I-96 TO I-94 CORRIDOR. FACTORING IN THE DRY NATURE OF THE ARCTIC
AIR AND STEADILY SHRINKING CONVECTIVE DEPTH...EXPECT ACCUMULATION
LIMITED TO LESS THAN AN INCH EVEN WITH NUMEROUS COVERAGE AND/OR A
STREAMER OF GREATER FOCUSED BANDING AT TIMES BEFORE DIMINISHING
TOWARD MIDNIGHT.
THE UPPER LEVEL TROUGH WILL SWING SOUTH OF LOWER MICHIGAN SHORTLY
AFTER MIDNIGHT AND WILL SHUT DOWN LAKE EFFECT PRODUCTION. STRONG
SUBSIDENCE TRAILING THE UPPER TROUGH AND PRECEDING THE RIDGE AXIS
WILL ALSO SUPPORT A CLEARING TREND MUCH LIKE WHAT OCCURRED EARLY
THIS MORNING. THIS WILL ALLOW ANOTHER ROUND OF SINGLE DIGIT MIN
TEMPS OUTSIDE OF METRO DETROIT AND MAINTAIN WIND CHILL NEAR 10
BELOW AT TIMES THROUGH TUESDAY MORNING. FORECAST CONCERNS WILL THEN
BE REDUCED TO CLOUD AND TEMPERATURE TRENDS DURING THE REST OF
TUESDAY AND TUESDAY NIGHT. BACKING LOW LEVEL FLOW WILL DIRECT
REMAINING LAKE EFFECT CLOUDS MAINLY INTO THE TRI CITIES BEFORE HIGH
PRESSURE BUILDS OVER THE REGION BY EVENING. LIGHTER WIND WILL MAKE
MAX TEMPS IN THE LOWER 20S EASIER TO TAKE COMPARED TO RECENT DAYS.
BENIGN CONDITIONS WILL CONTINUE THROUGH TUESDAY NIGHT AS HIGH CLOUDS
THICKEN AND LOWER IN ADVANCE OF THE NEXT LOW PRESSURE SYSTEM. THE
NEW MODEL PACKAGE IS IN GOOD AGREEMENT HOLDING OFF SNOW UNTIL
WEDNESDAY MORNING...MAINLY AFTER THE MORNING DRIVE...AND THEN
LEAVING UP TO AN INCH OF ACCUMULATION BEFORE ENDING BY MIDNIGHT
WEDNESDAY NIGHT. EXPECT THIS TO BE MOSTLY A MID LEVEL ISENTROPIC
LIFT DRIVEN EVENT AS MODEL DEPICTIONS OF THE 500 MB HEIGHT FIELD
SHOW CONSOLIDATION OF SHORT WAVES IN THE FLOW BUT WITH FRAGMENTED
DYNAMIC SUPPORT IN TERMS OF DCVA. THE LOW LEVEL FRONTAL ZONE IS ALSO
LOCATED WELL SOUTH INTO THE OHIO AND TENNESSEE VALLEYS JUDGING BY
1000-850 MB THICKNESS. THIS DOES NOT PREVENT ADEQUATE MOISTURE FROM
REACHING THIS FAR NORTH AS SPECIFIC HUMIDITY AVERAGES 1-2 G/KG UP TO
700 MB OVER LOWER MICHIGAN. IT DOES INDICATE THE SHALLOW AND STABLE
NATURE OF THE SYSTEM RELATIVE ISENTROPIC LIFT. AS MENTIONED IN THE
PREVIOUS DISCUSSION...MODEL SOUNDINGS DO INDICATE A DEEP ISOTHERMAL
PROFILE WITHIN THE DGZ BELOW 600 MB WHICH WILL GIVE A BOOST TO SNOW
RATIO AND POTENTIAL OVERACHIEVEMENT. THE COLLABORATED QPF ADJUSTMENTS
MADE IN THE PREVIOUS FORECAST CYCLE ARE THUS PRESERVED FOR THIS
PACKAGE.
EXTENDED THURSDAY THROUGH TUESDAY... AS WEDNESDAY`S WAVE OF LOW
PRESSURE EXITS THE REGION...A SLIGHT CHANCE OF SNOW SHOWERS WILL
REMAIN IN THE FORECAST THROUGH EARLY THURSDAY MORNING. BRIEF HIGH
PRESSURE BUILDS OVER THE AREA DURING THE DAY ON THURSDAY. THIS
HIGH PRESSURE IS EXPECTED TO PRODUCE A DECENT DRY DAY WITH MOSTLY
TO PARTLY CLOUDY SKIES OVER THE WHOLE OF SOUTHEAST MICHIGAN. AN
UPPER LEVEL TROUGH SWINGS ACROSS THE NORTHERN THUMB AREAS ON
FRIDAY...GENERATING ANOTHER WEAK SHOT AT SNOW SHOWERS. HIGH
PRESSURE IS ON TAP TO RETURN FOR THE WEEKEND. TEMPERATURE
CONTINUES TO WARM THROUGH THE PERIOD WITH HIGHS EDGING INTO THE
MID 30`S BY SUNDAY OVER SOUTHERN HALF OF THE CWA.
MARINE...
A SURFACE TROUGH SLOWLY DROPPING THROUGH LAKE HURON WILL MAINTAIN
STRONG WESTERLY WINDS THROUGH THE REMAINDER OF THE AFTERNOON AND
EVENING OVER SOUTHERN LAKE HURON...LAKE ST CLAIR...AND WESTERN LAKE
ERIE. WINDS WILL BE STRONGEST OVER THE SOUTHERN THIRD OF LAKE
HURON...WHERE GUSTS WILL PRIMARILY REMAIN AROUND 30 KNOTS...BUT A
FEW GUSTS TO GALE FORCE ARE POSSIBLE. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR THE NEARSHORE WATERS OF LAKE HURON FROM OUTER SAGINAW
BAY DOWN TO PORT HURON. THE REMAINDER OF THE NEARSHORE WATERS ARE
ICE COVERED AND THEREFORE REMAIN WITHOUT A HEADLINE. WINDS WILL
DECREASE EARLY TONIGHT AS THE SURFACE TROUGH DROPS SOUTHWARD.
IN ADDITION...THE STRONG WINDS AND ARCTIC AIRMASS IN PLACE WILL
CREATE FAVORABLE CONDITIONS FOR FREEZING SPRAY TO DEVELOP OVER LAKE
HURON THROUGH TUESDAY...ESPECIALLY ACROSS THE OPEN WATERS. INTENSITY
LOOKS TO ONLY REMAIN MODERATE HOWEVER.
WINDS WILL REMAIN A LITTLE GUSTY OUT OF THE NORTHWEST ACROSS LAKE
HURON TUESDAY BEFORE HIGH PRESSURE BUILDING INTO THE CENTRAL GREAT
LAKES AND OHIO VALLEY BRINGS LIGHTER WIND CONDITIONS FROM LATE
TUESDAY INTO WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ421-
441>443.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......CB
AVIATION.....CB
DISCUSSION...BT/DE
MARINE.......HLO
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
705 PM EST MON JAN 18 2016
.AVIATION...
A RAGGED STREAMER OF LAKE EFFECT SNOW SHOWERS HAS BECOME QUASI
STATIONARY ALONG AND NORTH OF THE INTERSTATE 96 CORRIDOR THIS
EVENING. CONDITIONS WITHIN THIS SNOW SHOWER ACTIVITY HAS BEEN
PRIMARILY MVFR BOTH IN CIG AND VSBY...BUT THE OCCASIONAL BRIEF IFR
VSBY HAS BEEN REPORTED AT TIMES. THE QUESTION MOVING FORWARD IS
HOW LONG THIS ACTIVITY WILL KEEP GOING. THE CELLULAR LOOK OF THE
CONVECTION OFFERED BY RADAR AND SATELLITE IMAGERY SUGGESTS A
DIURNAL/PEAK BOUNDARY LAYER GROWTH COMPONENT. THEREFORE...SUSPECT
THE SNOW SHOWER ACTIVITY WILL WEAKEN BY APPROXIMATELY 02Z WITH
THE MIXED LAYER SHRINKING. FLURRIES/LIGHT SNOW SHOWERS WILL REMAIN
PROBABLE THROUGH THE EVENING HOURS AND POSSIBLY AS LATE AS 06-08Z
WITH DEEPER COLUMN SUBSIDENCE SET TO IMPINGE DOWN ON SEMICH FROM
THE NORTH. MAINTAINED THE PRIOR FORECAST WITH NO HYDROMETEOR
MENTION AFTER 02Z WITH NO IMPACT EXPECTED.
FOR DTW...THE BAND OF LAKE EFFECT SNOW SHOWERS HAS REMAINED NORTH
OF THE TERMINAL THIS EVENING...AND THE EXPECTATION IS FOR THIS TO
CONTINUE. THE POTENTIAL FOR ADDITONAL FLURRIES/LIGHT SNOW SHOWERS
WILL END BY 06-08Z. MVFR CIGS TO HOLD THROUGH MUCH OF TONIGHT
BEFORE SCATTERING AROUND DAWN. STEEP LOW LEVEL LAPSE RATES AND
DIURNAL HEATING SHOULD LEAD TO MVFR CIGS AGAIN BY 17Z.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING AOB 5000 FT THROUGH LATE TONIGHT.
* HIGH FOR SNOW AS PRECIPITATION TYPE.
&&
.PREV DISCUSSION...ISSUED 350 PM EST MON JAN 18 2016
DISCUSSION...
LAKE EFFECT SNOW SHOWERS WILL HOLD WITH SCATTERED TO NUMEROUS
COVERAGE AND LIGHT TO MODERATE INTENSITY FOR THE REST OF THE
AFTERNOON THROUGH MID EVENING. THE MOST RECENT RAP SOUNDINGS
INDICATE CONVECTIVE DEPTH SETTLING STEADILY BELOW 5000 FT BETWEEN
21Z AND 03Z BUT WITH NEARLY DRY ADIABATIC LAPSE RATE AND HIGH ICE
SUPERSATURATION WITHIN THE CLOUD LAYER FOR HEALTHY GROWTH OF
DENDRITES. THAT BEING SAID...SURFACE DEWPOINT AROUND -10F REPORTED
UPSTREAM OF LAKE MICHIGAN HAS TO BE CONSIDERED A LIMITING FACTOR FOR
LAKE INDUCED CONVECTIVE POTENTIAL THIS FAR EAST. ON THE POSITIVE
SIDE...MID TO LATE AFTERNOON SURFACE OBSERVATIONS ON THIS SIDE OF
THE LAKE CONTINUE TO ADVERTISE GUSTY WEST FLOW WITH A GREATER AMOUNT
OF CONVERGENCE DOWN WIND OF LAKE MICHIGAN THAN WOULD NORMALLY BE
EXPECTED IN WELL MIXED MID AFTERNOON CONDITIONS. THIS WILL KEEP
COVERAGE WITH BETTER INTENSITY FOCUSED GENERALLY ALONG AND SOUTH OF
THE I-96 TO I-94 CORRIDOR. FACTORING IN THE DRY NATURE OF THE ARCTIC
AIR AND STEADILY SHRINKING CONVECTIVE DEPTH...EXPECT ACCUMULATION
LIMITED TO LESS THAN AN INCH EVEN WITH NUMEROUS COVERAGE AND/OR A
STREAMER OF GREATER FOCUSED BANDING AT TIMES BEFORE DIMINISHING
TOWARD MIDNIGHT.
THE UPPER LEVEL TROUGH WILL SWING SOUTH OF LOWER MICHIGAN SHORTLY
AFTER MIDNIGHT AND WILL SHUT DOWN LAKE EFFECT PRODUCTION. STRONG
SUBSIDENCE TRAILING THE UPPER TROUGH AND PRECEDING THE RIDGE AXIS
WILL ALSO SUPPORT A CLEARING TREND MUCH LIKE WHAT OCCURRED EARLY
THIS MORNING. THIS WILL ALLOW ANOTHER ROUND OF SINGLE DIGIT MIN
TEMPS OUTSIDE OF METRO DETROIT AND MAINTAIN WIND CHILL NEAR 10
BELOW AT TIMES THROUGH TUESDAY MORNING. FORECAST CONCERNS WILL THEN
BE REDUCED TO CLOUD AND TEMPERATURE TRENDS DURING THE REST OF
TUESDAY AND TUESDAY NIGHT. BACKING LOW LEVEL FLOW WILL DIRECT
REMAINING LAKE EFFECT CLOUDS MAINLY INTO THE TRI CITIES BEFORE HIGH
PRESSURE BUILDS OVER THE REGION BY EVENING. LIGHTER WIND WILL MAKE
MAX TEMPS IN THE LOWER 20S EASIER TO TAKE COMPARED TO RECENT DAYS.
BENIGN CONDITIONS WILL CONTINUE THROUGH TUESDAY NIGHT AS HIGH CLOUDS
THICKEN AND LOWER IN ADVANCE OF THE NEXT LOW PRESSURE SYSTEM. THE
NEW MODEL PACKAGE IS IN GOOD AGREEMENT HOLDING OFF SNOW UNTIL
WEDNESDAY MORNING...MAINLY AFTER THE MORNING DRIVE...AND THEN
LEAVING UP TO AN INCH OF ACCUMULATION BEFORE ENDING BY MIDNIGHT
WEDNESDAY NIGHT. EXPECT THIS TO BE MOSTLY A MID LEVEL ISENTROPIC
LIFT DRIVEN EVENT AS MODEL DEPICTIONS OF THE 500 MB HEIGHT FIELD
SHOW CONSOLIDATION OF SHORT WAVES IN THE FLOW BUT WITH FRAGMENTED
DYNAMIC SUPPORT IN TERMS OF DCVA. THE LOW LEVEL FRONTAL ZONE IS ALSO
LOCATED WELL SOUTH INTO THE OHIO AND TENNESSEE VALLEYS JUDGING BY
1000-850 MB THICKNESS. THIS DOES NOT PREVENT ADEQUATE MOISTURE FROM
REACHING THIS FAR NORTH AS SPECIFIC HUMIDITY AVERAGES 1-2 G/KG UP TO
700 MB OVER LOWER MICHIGAN. IT DOES INDICATE THE SHALLOW AND STABLE
NATURE OF THE SYSTEM RELATIVE ISENTROPIC LIFT. AS MENTIONED IN THE
PREVIOUS DISCUSSION...MODEL SOUNDINGS DO INDICATE A DEEP ISOTHERMAL
PROFILE WITHIN THE DGZ BELOW 600 MB WHICH WILL GIVE A BOOST TO SNOW
RATIO AND POTENTIAL OVERACHIEVEMENT. THE COLLABORATED QPF ADJUSTMENTS
MADE IN THE PREVIOUS FORECAST CYCLE ARE THUS PRESERVED FOR THIS
PACKAGE.
EXTENDED THURSDAY THROUGH TUESDAY... AS WEDNESDAY`S WAVE OF LOW
PRESSURE EXITS THE REGION...A SLIGHT CHANCE OF SNOW SHOWERS WILL
REMAIN IN THE FORECAST THROUGH EARLY THURSDAY MORNING. BRIEF HIGH
PRESSURE BUILDS OVER THE AREA DURING THE DAY ON THURSDAY. THIS
HIGH PRESSURE IS EXPECTED TO PRODUCE A DECENT DRY DAY WITH MOSTLY
TO PARTLY CLOUDY SKIES OVER THE WHOLE OF SOUTHEAST MICHIGAN. AN
UPPER LEVEL TROUGH SWINGS ACROSS THE NORTHERN THUMB AREAS ON
FRIDAY...GENERATING ANOTHER WEAK SHOT AT SNOW SHOWERS. HIGH
PRESSURE IS ON TAP TO RETURN FOR THE WEEKEND. TEMPERATURE
CONTINUES TO WARM THROUGH THE PERIOD WITH HIGHS EDGING INTO THE
MID 30`S BY SUNDAY OVER SOUTHERN HALF OF THE CWA.
MARINE...
A SURFACE TROUGH SLOWLY DROPPING THROUGH LAKE HURON WILL MAINTAIN
STRONG WESTERLY WINDS THROUGH THE REMAINDER OF THE AFTERNOON AND
EVENING OVER SOUTHERN LAKE HURON...LAKE ST CLAIR...AND WESTERN LAKE
ERIE. WINDS WILL BE STRONGEST OVER THE SOUTHERN THIRD OF LAKE
HURON...WHERE GUSTS WILL PRIMARILY REMAIN AROUND 30 KNOTS...BUT A
FEW GUSTS TO GALE FORCE ARE POSSIBLE. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR THE NEARSHORE WATERS OF LAKE HURON FROM OUTER SAGINAW
BAY DOWN TO PORT HURON. THE REMAINDER OF THE NEARSHORE WATERS ARE
ICE COVERED AND THEREFORE REMAIN WITHOUT A HEADLINE. WINDS WILL
DECREASE EARLY TONIGHT AS THE SURFACE TROUGH DROPS SOUTHWARD.
IN ADDITION...THE STRONG WINDS AND ARCTIC AIRMASS IN PLACE WILL
CREATE FAVORABLE CONDITIONS FOR FREEZING SPRAY TO DEVELOP OVER LAKE
HURON THROUGH TUESDAY...ESPECIALLY ACROSS THE OPEN WATERS. INTENSITY
LOOKS TO ONLY REMAIN MODERATE HOWEVER.
WINDS WILL REMAIN A LITTLE GUSTY OUT OF THE NORTHWEST ACROSS LAKE
HURON TUESDAY BEFORE HIGH PRESSURE BUILDING INTO THE CENTRAL GREAT
LAKES AND OHIO VALLEY BRINGS LIGHTER WIND CONDITIONS FROM LATE
TUESDAY INTO WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ421-
441>443.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....CB
DISCUSSION...BT/DE
MARINE.......HLO
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
409 PM EST SUN JAN 17 2016
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 408 PM EST SUN JAN 17 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A COLD MID/UPPER LEVEL LOW
JUST TO THE EAST OF LAKE SUPERIOR. AT THE SFC...NW LOW LEVEL FLOW
PREVAILED BTWN A RIDGE OVER THE PLAINS AND A TROUGH FROM JAMES BAY
TO SRN ONTARIO. RADAR AND VIS LOOP SHOWED MAINLY MULTI-BAND LES WITH
FEW DOMINANT OR COHERENT BANDSAS THE LES INTENSITY HAS DIMINISHED
SLIGHTLY WITH THE VERY DRY ARCTIC AIR UPSTREAM AND THE LAKES
AGGREGATE TROUGH SHIFTING TO THE SOUTH OF UPPER MICHIGAN.
INSTABILITIY OVER THE LAKE REMAINED HIGH WITH 850/700 MB TEMPS
AROUND -23C/-30C RESULTING IN LAKE INDUCED CAPES NEAR 1K J/KG AND
EQUILLIBRIUM HEIGHTS TO 14K FT.
TONIGHT...EXPECT MODERATE TO OCASSIONALLY HEAV LES TO CONTINUE FOR
NW FLOW FAVORED LOCATIONS. THE HIGH RES MODELS SUGGEST THAT THE MOST
FAVORALBE LOW LEVEL CONV OVER THE WEST WILL FOCUS INTO ONTONAGAON
COUNTY THIS EVENING. OVER THE EAST...MORE DOMINANT BANDS COULD OVER
A WIDER AREA FROM FROM ALGER COUNTY INTO LUCE COUNTY. LES INTENSITY
SHOULD ALSO INCREASE WITH A SHRTWV OVER NRN ONTARIO ROTATING TO NEAR
ERN LAKE SUPERIOR BY 12Z. HOWEVER...WINDS WILL ALSO BACK SLIGHTLY IN
RESPONSE TO THE INCOMING SHRTWV. ALTHOUGH SNOWFALL AMOUNTS MAY NOT
BE AS HEAVY AS LAST NIGHT...5 TO 9 INCH AMOUNTS WILL BE POSSIBLE
OVER THE EAST. THE SHORTER FETCH AND SLIGHTLY LOWER INVERSION
HEIGHTS OVER THE WEST SHOULD KEEP AMOUNTS IN THE 2 TO 5 INCH RANGE.
ENOUGH OF THE CONVECTIVE LAYER WILL REACH INTO THE DGZ TO KEEP SLR
VALUES AOA 25/1.
THE VERY COLD AIR MOVING INTO INTERIOR LOCATIONS WILL DROP WIND
CHILLS INTO THE -20 TO -30 RANGE NEAR THE WI BORDER FROM IRONWOOD TO
CRYSTAL FALLS TONIGHT WHERE A WIND CHILL ADVY REMAINS IN EFFECT.
EXPECT ENOUGH LAKE MODERATION FARTHER NORTH FOR WIND CHILLS MAINLY
IN THE -10 TO -20 RANGE.
MONDAY...AS THE SHRTWV MOVES IN WITH THE STRONGER FORCING SHIFTING
TO THE SOUTH...WINDS WILL GRADUALY VEER. CONDITIONS WILL REMAIN
FAVORABLE FOR MODERATE TO HEAVY LES...AGAIN HEAVIEST OVER THE EAST
WITH SLIGHTLY HIGHER INVERSION HEIGHTS AND LONGER FETCH LENGTHS.
WARNINGS AND ADVISORIES WILL REMAIN IN EFFECT THROUGH THE DAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 547 AM EST SUN JAN 17 2016
...LAKE EFFECT SNOW GRADUALLY DIMINISHES MON NIGHT INTO TUE...
UPPER TROUGH OVER THE GREAT LAKES MOVES OVER FAR EASTERN CANADA
EARLY THIS WEEK AND OFF ACROSS THE NORTH ATLANTIC BY WED WHILE
AMPLFIED ZONAL FLOW DEVELOPS OVER THE CONUS. COLD AIR WITH H85 TEMPS
DOWN TO -22C ON MON MORNING EASES BY TUE AND WED AS H85 TEMPS RISE TO
-14C BY LATE TUE INTO WED. LAKE INDUCED TROUGHING PERSISTS THROUGH
MONDAY...BUT UNLIKE THIS MORNING WITH MESOLOW ON THE
TROUGH...APPEARS THAT OVERALL RISING HEIGHTS ALOFT WILL RESULT IN
MORE OF A STEADY STATE CONVERGENT NW FLOW ON MONDAY....FOCUSING OVER
ALGER THROUGH LUCE COUNTIES. SOUNDINGS SHOW SLOWLY DIMINISHING
INSTABILITY...BUT STILL LOOKING AT INVERSIONS NEAR 5KFT OVER WESTERN
CWA AND NEAR 10KFT OVER EAST CWA. SHORTWAVE AND DEEP LAYER FORCING
DROPPING ACROSS LK SUPERIOR AND UPR MICHIGAN...ESPECIALLY EAST HALF
WILL CONTINUE TO LEAD TO HEAVY LAKE ENHANCED SNOW WITH SNOW RATES
OVER 1 INCH PER HOUR. BASED ON HOW THIS EVENT HAS WENT THUS FAR
THOUGH WITH TREMENDOUS HOURLY SNOW RATES AIDED IN LARGE PART BY VERY
HIGH SLR/S OVER 30:1...SHOULD SEE RATES 1-3 INCHES PER HOUR IN THE
HEAVIEST SNOW BANDS. BY MON AFTN...LARGER SCALE FORCING BEGINS TO
DIMINISH AS SHORTWAVE EXITS THE AREA AND Q-VECTOR DIVERGENCE MOVES
IN WITH SUBSIDENCE. INVERSIONS BEGIN TO FALL SHARPLY MON EVENING SO
EVEN THOUGH MAJORITY OF MOIST LAKE EFFECT LAYER REMAINS IN THE
DGZ...EXPECT SNOW INTENSITY TO START TAKING BIGGER HIT. AS THE SFC
RIDGE OVER THE NORTHERN PLAINS ATTEMPTS TO MOVE MORE NORTH OF LK
SUPERIOR...SFC-H925 WINDS VEER NNW FM NW SO MAY SEE SNOW SHOWERS
MOVE BACK OVER MORE AREAS NEAR LK SUPERIOR. WITH THE NEGATIVE
FACTORS MENTIONED INTENSITY SHOULD BE COMING DOWN BUT WILL KEEP POPS
HIGH FOR MAINLY LIGHT SNOW AMOUNTS. LATE ON MON NIGHT WINDS BACK
MORE NW AGAIN...SO EXPECT LAKE EFFECT TO RETURN TO NW SNOW BELTS BY
TUE MORNING WHERE IT SHOULD REMAIN UNTIL TUE NIGHT IN DIMINISHED
STATE AS WINDS BECOME OFFSHORE AS SFC RIDGE MOVES ACROSS.
AS FOR QPF/SNOW...SIMILAR TO LAST NIGHT RAMPED UP QPF/SNOW COMPARED
TO CONSENSUS AND WPC. GIVEN QPF WHICH EXCEEDED TWO TENTHS OF AN INCH
IN 6 HOURS WHERE HEAVIER SNOW BANDS WERE EXPECTED ALONG WITH SLR/S
25-30:1 YIELDED A 12 HOUR SNOWFALL OF 3-6 INCHES OVER WESTERN UPR
MICHIGAN ON MON WITH AMOUNTS MORE TOWARD 5-8 INCHES OVER
ALGER/NORTHERN SCHOOLCRAFT AND LUCE COUNTIES AS PERSISTENT HIGH
INSTABILITY LAKE EFFECT SETUP IS MORE AFFECTED DIRECTLY BY SHORTWAVE
DROPPING SOUTH ACROSS THE AREA THROUGH AT LEAST MID AFTN ON MON.
BASED ON THE HIGHER THAN EXPECTED SLR/S OF THIS EVENT THUS FAR WOULD
NOT BE SURPRISED TO SEE HIGHER SLR/S AND THUS HIGHER SNOW
AMOUNTS...AT LEAST LOCALLY. COORD WITH SHORT TERM FORECASTER AND
DECIDED TO PUT WARNINGS UP FOR NORTHERN SCHOOLCRAFT AND LUCE
COUNTIES AND EXTEND WESTERN UPR MICHIGAN WARNING THROUGH MON. ADVYS
SURROUND THESE AREAS. NO DOUBT THAT HEADLINES MAY NEED TWEAKING AS
HIGHLY MESOSCALE DETAILS FOR WHERE HEAVIEST SNOW DEVELOPS BECOMES
MORE APPARENT TONIGHT INTO MONDAY MORNING.
REST OF EXTENDED FEATURES A WARMING TREND MID TO LATE THIS WEEK. MAY
SEE SOME READINGS NEAR 30 DEGREES AGAIN BY NEXT WEEKEND. WEAK
SHORTWAVE CROSSING WESTERN GREAT LAKES ON WED. A LOT OF MID LEVEL
MOISTURE BUT LOW-LEVEL MOISTURE IS LACKING DUE TO ARCTIC HIGH VCNTY
OF UPPER GREAT LAKES. RAN WITH SLIGHT CHANCE POPS SPREADING FM WEST
TO EAST. BEST CHANCE OF SNOW WILL BE OVER KEWEENAW DUE TO THE
FORCING FM THE SYSTEM AND ENOUGH INSTABILITY FOR LAKE ENHANCED SNOW.
INVERSIONS STAY AT 5KFT OR LESS SO NOT EXPECTING HEAVIER SNOW.
ADDITIONAL SHORTWAVE MOVES THROUGH WED NIGHT INTO THU WITH WEAK
TROUGH PASSAGE TIED TO IT. MAY SEE SNOW SHOWERS INCREASING LATE THIS
WEEK CLOSER TO LK SUPERIOR THOUGH TEMPS BARELY BOTTOM OUT AT -
15C...SO LAKE EFFECT SHOULD BE ON THE LIGHTER SIDE WITH LAKE TEMPS 2-
3C.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1249 PM EST SUN JAN 17 2016
AT KIWD/KCMX...NW FLOW LAKE EFFECT CONTINUES INTO MONDAY. EXPECT IFR
VSBY DURING THE HEAVIER SNOW BANDS AT IWD...BUT WILL STAY MVFR FOR
THE MOST PART. IFR/LIFR VSBY AT CMX WILL CONTINUE THROUGH THIS
FORECAST PERIOD AND THIS WILL BE A VARIABLE CONDITION.
AT KSAW...VFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE FORECAST
PERIOD WITH THE LAKE EFFECT SNOW SHOWERS STAYING MOSTLY TO THE EAST.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 PM EST SUN JAN 17 2016
A TIGHT GRADIENT WILL REMAIN ACROSS LAKE SUPERIOR INTO EARLY
TUESDAY...KEEPING WIND GUSTS BETWEEN 25-30KTS WITH HIGHER GALE FORCE
GUSTS TO 35 KNOTS POSSIBLE OVER EASTERN LAKE SUPERIOR LATE THIS
AFTERNOON INTO TONIGHT. IN ADDITION...HEAVY FREEZING SPRAY IS
EXPECTED TODAY INTO MONDAY. WINDS ARE EXPECTED TO SLOWLY DIMINISH
TOWARDS THE MIDDLE OF NEXT WEEK...AS HIGH PRESSURE MOVES OVER THE
UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST MONDAY FOR MIZ002-003-
006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ001-014-
084.
WIND CHILL ADVISORY UNTIL NOON CST MONDAY FOR MIZ009-010.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST MONDAY FOR
LSZ263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...- NONE -
MARINE...- NONE -
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1253 PM EST SUN JAN 17 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 550 AM EST SUN JAN 17 2016
LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A COLD MID/UPPER LEVEL
LOW MOVING INTO NW LAKE SUPERIOR. AT THE SFC...LAKE INDUCED TROUGH
HAS KEPT WINDS MORE NORTHERLY OVER LAKE SUPERIOR WHILE OVER UPPER MI
WINDS ARE MORE WEST TO NORTHWEST. RESULTING STRONG LOW LEVEL
CONVERGENCE FROM LAKE INDUCED TROF AND ENHANCEMENT ASSOC WITH MID-
UPR LEVEL LOW HAS RESULTED IN VERY INTENSE AND HEAVY LES BANDS INTO
ALGER AND FAR EASTERN MARQUETTE COUNTIES. REPORTS FROM ALGER COUNTY
SHERIFF IN MUNISING ESTIMATED AROUND A FOOT OF SNOW ACCMULATION
SINCE LATE SATURDAY EVENING WITH SNOWFALL RATES EXCEEDING 3 INCHES
PER HOUR AT TIMES. STRONG CONVERGENCE ALSO SUPPORTING HEAVY SNOW
BAND INTO ONTONAGON WITH SIX INCHES THIS LAST EVENING.
TODAY INTO TONIGHT...GIVEN STRONG LOW-LEVEL CONVERGENCE IN PLACE
WITH DEEP CYCLONIC N-NW FLOW AND ENHANCEMENT FROM MID-UPPER LEVEL
LOW...EXPECT HEAVY LES BANDS TO CONTINUE INTO THE LATE MORNING HOURS
FOR FAR ERN MARQUETTE COUNTY...SO DECIDED TO ISSUED A LES WARNING.
BACKING OF WINDS BEHIND PASSAGE OF SFC TROUGH SOUTH THROUGH ERN
UPPER MI THIS MORNING WILL PUSH HEAVY LES BAND OUT OF ERN MQT COUNTY
AND INTO ALGER AND NRN SCHOOLCRAFT COUNTY. STRONG LOW-LVL
CONVERGENCE SETTING UP OVER ALGER...NRN SCHOOLCRAFT AND COUNTIES
FROM PERSISTENT LAKE INDUCED TROF COMBINED WITH POTENTIAL
ENHANCEMENT FROM SHORTWAVE ROTATING SOUTH ACROSS ERN LAKE SUPERIOR
ON MONDAY WILL CONTINUE FAVORABLE ENVIRONMENT FOR HEAVY LES BANDS.
MODEL SOUNDINGS SUGGEST LAKE INDUCED CAPE NEAR 1000 J/KG AND
EQUILIBRIUM LEVEL TO NEAR 13 KFT WITH DGZ STILL FAVORABLY PLACED
WITHIN CONVECTIVE BOUNDARY LAYER YIELDING 25-30/1 SLR/S. THESE
CONDITIONS COULD EASILY SUPPORT HEAVY LES BANDS WITH SNOWFALL RATES
ON ORDER OF 1 TO 2 INCHES PER HOUR WITHIN MORE INTENSE BANDS FOR
ALGER...NRN SCHOOLCRAFT INTO LUCE COUNTIES. THUS...HAVE DECIDED TO
UPGRADE TO LES WARNINGS FOR NRN SCHOOLCRAFT AND LUCE COUNTIES
CONTINUING THROUGH MONDAY CONSISTENT WITH WARNING ALREADY IN PLACE
FOR ALGER COUNTY. SOME AREAS ACROSS ALGER AND NRN SCHOOLCRAFT COULD
SEE AN ADDITIONAL 20 INCHES OF FRESH SNOWFALL THROUGH MONDAY.
DECIDED TO ISSUE A LES ADVISORY FOR DELTA COUNTY...MAINLY OVER THE
NE PORTION WHERE MODERATE SNOW COULD ACCMULATE UP TO 6 INCHES TODAY.
ALSO ISSUED AN ADVISORY FOR SRN SCHOOLCRAFT TODAY INTO MONDAY AS
AREAS NEAR GERMFASK TO STEUBEN COULD APPROACH 8 TO MAYBE 12 INCHES
OF LES ACCUMULATION.
AS FOR WESTERN COUNTIES...GIVEN REPORT OF HEAVY SNOW IN CITY OF
ONTONAGON AND PERSISTENT STRONG LOW-LVL CONVERGENCE INTO ONTONAGON
AND TWIN LAKES PORTION OF NRN HOUGHTON COUNTY HAVE ALSO DECIDED TO
EXTEND LES WARNING FOR THESE TWO COUNTIES THROUGH MONDAY AS WELL.
BELIEVE STRONG LOW-LVL CONVERGENCE AND DEEP CYCLONIC NW FLOW WILL
OVERCOME SLIGHTLY LESS FAVORABLE DENDRITIC SNOW GROWTH. WOULD NOT BE
SURPRISED TO SEE SEVERAL LOCATIONS APPROACH A FOOT OF ADDITIONAL
SNOWFALL ESPECIALLY OVER PORCUPINE MTNS AND TWIN LAKES AREAS. IN
TURN ALSO DECIDED TO EXTEND LES ADVISORIES FOR SRN HOUGHTON FOR
ADDITIONAL ACCUMULATION OF 4 TO 8 INCHES THROUGH MONDAY.
THE VERY COLD AIR MOVING INTO INTERIOR LOCATIONS WILL DROP WIND
CHILLS INTO THE -20 TO -30 RANGE NEAR THE WI BORDER FROM IRONWOOD TO
CRYSTAL FALLS EARLY THIS MORNING AND AGAIN TONIGHT WHERE A WIND
CHILL ADVY WAS ISSUED. EXPECT ENOUGH LAKE MODERATION FARTHER NORTH
FOR WIND CHILLS MAINLY IN THE -10 TO -20 RANGE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 547 AM EST SUN JAN 17 2016
...LAKE EFFECT SNOW GRADUALLY DIMINISHES MON NIGHT INTO TUE...
UPPER TROUGH OVER THE GREAT LAKES MOVES OVER FAR EASTERN CANADA
EARLY THIS WEEK AND OFF ACROSS THE NORTH ATLANTIC BY WED WHILE
AMPLFIED ZONAL FLOW DEVELOPS OVER THE CONUS. COLD AIR WITH H85 TEMPS
DOWN TO -22C ON MON MORNING EASES BY TUE AND WED AS H85 TEMPS RISE TO
-14C BY LATE TUE INTO WED. LAKE INDUCED TROUGHING PERSISTS THROUGH
MONDAY...BUT UNLIKE THIS MORNING WITH MESOLOW ON THE
TROUGH...APPEARS THAT OVERALL RISING HEIGHTS ALOFT WILL RESULT IN
MORE OF A STEADY STATE CONVERGENT NW FLOW ON MONDAY....FOCUSING OVER
ALGER THROUGH LUCE COUNTIES. SOUNDINGS SHOW SLOWLY DIMINISHING
INSTABILITY...BUT STILL LOOKING AT INVERSIONS NEAR 5KFT OVER WESTERN
CWA AND NEAR 10KFT OVER EAST CWA. SHORTWAVE AND DEEP LAYER FORCING
DROPPING ACROSS LK SUPERIOR AND UPR MICHIGAN...ESPECIALLY EAST HALF
WILL CONTINUE TO LEAD TO HEAVY LAKE ENHANCED SNOW WITH SNOW RATES
OVER 1 INCH PER HOUR. BASED ON HOW THIS EVENT HAS WENT THUS FAR
THOUGH WITH TREMENDOUS HOURLY SNOW RATES AIDED IN LARGE PART BY VERY
HIGH SLR/S OVER 30:1...SHOULD SEE RATES 1-3 INCHES PER HOUR IN THE
HEAVIEST SNOW BANDS. BY MON AFTN...LARGER SCALE FORCING BEGINS TO
DIMINISH AS SHORTWAVE EXITS THE AREA AND Q-VECTOR DIVERGENCE MOVES
IN WITH SUBSIDENCE. INVERSIONS BEGIN TO FALL SHARPLY MON EVENING SO
EVEN THOUGH MAJORITY OF MOIST LAKE EFFECT LAYER REMAINS IN THE
DGZ...EXPECT SNOW INTENSITY TO START TAKING BIGGER HIT. AS THE SFC
RIDGE OVER THE NORTHERN PLAINS ATTEMPTS TO MOVE MORE NORTH OF LK
SUPERIOR...SFC-H925 WINDS VEER NNW FM NW SO MAY SEE SNOW SHOWERS
MOVE BACK OVER MORE AREAS NEAR LK SUPERIOR. WITH THE NEGATIVE
FACTORS MENTIONED INTENSITY SHOULD BE COMING DOWN BUT WILL KEEP POPS
HIGH FOR MAINLY LIGHT SNOW AMOUNTS. LATE ON MON NIGHT WINDS BACK
MORE NW AGAIN...SO EXPECT LAKE EFFECT TO RETURN TO NW SNOW BELTS BY
TUE MORNING WHERE IT SHOULD REMAIN UNTIL TUE NIGHT IN DIMINISHED
STATE AS WINDS BECOME OFFSHORE AS SFC RIDGE MOVES ACROSS.
AS FOR QPF/SNOW...SIMILAR TO LAST NIGHT RAMPED UP QPF/SNOW COMPARED
TO CONSENSUS AND WPC. GIVEN QPF WHICH EXCEEDED TWO TENTHS OF AN INCH
IN 6 HOURS WHERE HEAVIER SNOW BANDS WERE EXPECTED ALONG WITH SLR/S
25-30:1 YIELDED A 12 HOUR SNOWFALL OF 3-6 INCHES OVER WESTERN UPR
MICHIGAN ON MON WITH AMOUNTS MORE TOWARD 5-8 INCHES OVER
ALGER/NORTHERN SCHOOLCRAFT AND LUCE COUNTIES AS PERSISTENT HIGH
INSTABILITY LAKE EFFECT SETUP IS MORE AFFECTED DIRECTLY BY SHORTWAVE
DROPPING SOUTH ACROSS THE AREA THROUGH AT LEAST MID AFTN ON MON.
BASED ON THE HIGHER THAN EXPECTED SLR/S OF THIS EVENT THUS FAR WOULD
NOT BE SURPRISED TO SEE HIGHER SLR/S AND THUS HIGHER SNOW
AMOUNTS...AT LEAST LOCALLY. COORD WITH SHORT TERM FORECASTER AND
DECIDED TO PUT WARNINGS UP FOR NORTHERN SCHOOLCRAFT AND LUCE
COUNTIES AND EXTEND WESTERN UPR MICHIGAN WARNING THROUGH MON. ADVYS
SURROUND THESE AREAS. NO DOUBT THAT HEADLINES MAY NEED TWEAKING AS
HIGHLY MESOSCALE DETAILS FOR WHERE HEAVIEST SNOW DEVELOPS BECOMES
MORE APPARENT TONIGHT INTO MONDAY MORNING.
REST OF EXTENDED FEATURES A WARMING TREND MID TO LATE THIS WEEK. MAY
SEE SOME READINGS NEAR 30 DEGREES AGAIN BY NEXT WEEKEND. WEAK
SHORTWAVE CROSSING WESTERN GREAT LAKES ON WED. A LOT OF MID LEVEL
MOISTURE BUT LOW-LEVEL MOISTURE IS LACKING DUE TO ARCTIC HIGH VCNTY
OF UPPER GREAT LAKES. RAN WITH SLIGHT CHANCE POPS SPREADING FM WEST
TO EAST. BEST CHANCE OF SNOW WILL BE OVER KEWEENAW DUE TO THE
FORCING FM THE SYSTEM AND ENOUGH INSTABILITY FOR LAKE ENHANCED SNOW.
INVERSIONS STAY AT 5KFT OR LESS SO NOT EXPECTING HEAVIER SNOW.
ADDITIONAL SHORTWAVE MOVES THROUGH WED NIGHT INTO THU WITH WEAK
TROUGH PASSAGE TIED TO IT. MAY SEE SNOW SHOWERS INCREASING LATE THIS
WEEK CLOSER TO LK SUPERIOR THOUGH TEMPS BARELY BOTTOM OUT AT -
15C...SO LAKE EFFECT SHOULD BE ON THE LIGHTER SIDE WITH LAKE TEMPS 2-
3C.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1249 PM EST SUN JAN 17 2016
AT KIWD/KCMX...NW FLOW LAKE EFFECT CONTINUES INTO MONDAY. EXPECT IFR
VSBY DURING THE HEAVIER SNOW BANDS AT IWD...BUT WILL STAY MVFR FOR
THE MOST PART. IFR/LIFR VSBY AT CMX WILL CONTINUE THROUGH THIS
FORECAST PERIOD AND THIS WILL BE A VARIABLE CONDITION.
AT KSAW...VFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE FORECAST
PERIOD WITH THE LAKE EFFECT SNOW SHOWERS STAYING MOSTLY TO THE EAST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 550 AM EST SUN JAN 17 2016
A LOW MOVING FROM SOUTHERN ONTARIO TO QUEBEC WILL BRING COLDER AIR
ACROSS LK SUPERIOR THROUGH THE WEEKEND. BEHIND THE LOW...A TROUGH
WILL REMAIN FAIRLY STATIONARY OVER SOUTHERN LAKE SUPERIOR INTO EARLY
TUESDAY...KEEPING WIND GUSTS BETWEEN 25-30KTS WITH HIGHER GALE FORCE
GUSTS TO 35 KNOTS POSSIBLE OVER EASTERN LAKE SUPERIOR LATE THIS
AFTERNOON INTO TONIGHT. IN ADDITION...HEAVY FREEZING SPRAY IS
EXPECTED TODAY INTO MONDAY. WINDS ARE EXPECTED TO SLOWLY DIMINISH
TOWARDS THE MIDDLE OF NEXT WEEK...AS HIGH PRESSURE MOVES OVER THE
UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST MONDAY FOR MIZ002-003-
006-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ001-
013.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ014-084.
WIND CHILL ADVISORY UNTIL NOON CST MONDAY FOR MIZ009-010.
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ007.
LAKE EFFECT SNOW WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST
MONDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST MONDAY FOR
LSZ263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...- NONE -
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
651 AM EST SUN JAN 17 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 550 AM EST SUN JAN 17 2016
LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A COLD MID/UPPER LEVEL
LOW MOVING INTO NW LAKE SUPERIOR. AT THE SFC...LAKE INDUCED TROUGH
HAS KEPT WINDS MORE NORTHERLY OVER LAKE SUPERIOR WHILE OVER UPPER MI
WINDS ARE MORE WEST TO NORTHWEST. RESULTING STRONG LOW LEVEL
CONVERGENCE FROM LAKE INDUCED TROF AND ENHANCEMENT ASSOC WITH MID-
UPR LEVEL LOW HAS RESULTED IN VERY INTENSE AND HEAVY LES BANDS INTO
ALGER AND FAR EASTERN MARQUETTE COUNTIES. REPORTS FROM ALGER COUNTY
SHERIFF IN MUNISING ESTIMATED AROUND A FOOT OF SNOW ACCMULATION
SINCE LATE SATURDAY EVENING WITH SNOWFALL RATES EXCEEDING 3 INCHES
PER HOUR AT TIMES. STRONG CONVERGENCE ALSO SUPPORTING HEAVY SNOW
BAND INTO ONTONAGON WITH SIX INCHES THIS LAST EVENING.
TODAY INTO TONIGHT...GIVEN STRONG LOW-LEVEL CONVERGENCE IN PLACE
WITH DEEP CYCLONIC N-NW FLOW AND ENHANCEMENT FROM MID-UPPER LEVEL
LOW...EXPECT HEAVY LES BANDS TO CONTINUE INTO THE LATE MORNING HOURS
FOR FAR ERN MARQUETTE COUNTY...SO DECIDED TO ISSUED A LES WARNING.
BACKING OF WINDS BEHIND PASSAGE OF SFC TROUGH SOUTH THROUGH ERN
UPPER MI THIS MORNING WILL PUSH HEAVY LES BAND OUT OF ERN MQT COUNTY
AND INTO ALGER AND NRN SCHOOLCRAFT COUNTY. STRONG LOW-LVL
CONVERGENCE SETTING UP OVER ALGER...NRN SCHOOLCRAFT AND COUNTIES
FROM PERSISTENT LAKE INDUCED TROF COMBINED WITH POTENTIAL
ENHANCEMENT FROM SHORTWAVE ROTATING SOUTH ACROSS ERN LAKE SUPERIOR
ON MONDAY WILL CONTINUE FAVORABLE ENVIRONMENT FOR HEAVY LES BANDS.
MODEL SOUNDINGS SUGGEST LAKE INDUCED CAPE NEAR 1000 J/KG AND
EQUILIBRIUM LEVEL TO NEAR 13 KFT WITH DGZ STILL FAVORABLY PLACED
WITHIN CONVECTIVE BOUNDARY LAYER YIELDING 25-30/1 SLR/S. THESE
CONDITIONS COULD EASILY SUPPORT HEAVY LES BANDS WITH SNOWFALL RATES
ON ORDER OF 1 TO 2 INCHES PER HOUR WITHIN MORE INTENSE BANDS FOR
ALGER...NRN SCHOOLCRAFT INTO LUCE COUNTIES. THUS...HAVE DECIDED TO
UPGRADE TO LES WARNINGS FOR NRN SCHOOLCRAFT AND LUCE COUNTIES
CONTINUING THROUGH MONDAY CONSISTENT WITH WARNING ALREADY IN PLACE
FOR ALGER COUNTY. SOME AREAS ACROSS ALGER AND NRN SCHOOLCRAFT COULD
SEE AN ADDITIONAL 20 INCHES OF FRESH SNOWFALL THROUGH MONDAY.
DECIDED TO ISSUE A LES ADVISORY FOR DELTA COUNTY...MAINLY OVER THE
NE PORTION WHERE MODERATE SNOW COULD ACCMULATE UP TO 6 INCHES TODAY.
ALSO ISSUED AN ADVISORY FOR SRN SCHOOLCRAFT TODAY INTO MONDAY AS
AREAS NEAR GERMFASK TO STEUBEN COULD APPROACH 8 TO MAYBE 12 INCHES
OF LES ACCUMULATION.
AS FOR WESTERN COUNTIES...GIVEN REPORT OF HEAVY SNOW IN CITY OF
ONTONAGON AND PERSISTENT STRONG LOW-LVL CONVERGENCE INTO ONTONAGON
AND TWIN LAKES PORTION OF NRN HOUGHTON COUNTY HAVE ALSO DECIDED TO
EXTEND LES WARNING FOR THESE TWO COUNTIES THROUGH MONDAY AS WELL.
BELIEVE STRONG LOW-LVL CONVERGENCE AND DEEP CYCLONIC NW FLOW WILL
OVERCOME SLIGHTLY LESS FAVORABLE DENDRITIC SNOW GROWTH. WOULD NOT BE
SURPRISED TO SEE SEVERAL LOCATIONS APPROACH A FOOT OF ADDITIONAL
SNOWFALL ESPECIALLY OVER PORCUPINE MTNS AND TWIN LAKES AREAS. IN
TURN ALSO DECIDED TO EXTEND LES ADVISORIES FOR SRN HOUGHTON FOR
ADDITIONAL ACCUMULATION OF 4 TO 8 INCHES THROUGH MONDAY.
THE VERY COLD AIR MOVING INTO INTERIOR LOCATIONS WILL DROP WIND
CHILLS INTO THE -20 TO -30 RANGE NEAR THE WI BORDER FROM IRONWOOD TO
CRYSTAL FALLS EARLY THIS MORNING AND AGAIN TONIGHT WHERE A WIND
CHILL ADVY WAS ISSUED. EXPECT ENOUGH LAKE MODERATION FARTHER NORTH
FOR WIND CHILLS MAINLY IN THE -10 TO -20 RANGE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 547 AM EST SUN JAN 17 2016
...LAKE EFFECT SNOW GRADUALLY DIMINISHES MON NIGHT INTO TUE...
UPPER TROUGH OVER THE GREAT LAKES MOVES OVER FAR EASTERN CANADA
EARLY THIS WEEK AND OFF ACROSS THE NORTH ATLANTIC BY WED WHILE
AMPLFIED ZONAL FLOW DEVELOPS OVER THE CONUS. COLD AIR WITH H85 TEMPS
DOWN TO -22C ON MON MORNING EASES BY TUE AND WED AS H85 TEMPS RISE TO
-14C BY LATE TUE INTO WED. LAKE INDUCED TROUGHING PERSISTS THROUGH
MONDAY...BUT UNLIKE THIS MORNING WITH MESOLOW ON THE
TROUGH...APPEARS THAT OVERALL RISING HEIGHTS ALOFT WILL RESULT IN
MORE OF A STEADY STATE CONVERGENT NW FLOW ON MONDAY....FOCUSING OVER
ALGER THROUGH LUCE COUNTIES. SOUNDINGS SHOW SLOWLY DIMINISHING
INSTABILITY...BUT STILL LOOKING AT INVERSIONS NEAR 5KFT OVER WESTERN
CWA AND NEAR 10KFT OVER EAST CWA. SHORTWAVE AND DEEP LAYER FORCING
DROPPING ACROSS LK SUPERIOR AND UPR MICHIGAN...ESPECIALLY EAST HALF
WILL CONTINUE TO LEAD TO HEAVY LAKE ENHANCED SNOW WITH SNOW RATES
OVER 1 INCH PER HOUR. BASED ON HOW THIS EVENT HAS WENT THUS FAR
THOUGH WITH TREMENDOUS HOURLY SNOW RATES AIDED IN LARGE PART BY VERY
HIGH SLR/S OVER 30:1...SHOULD SEE RATES 1-3 INCHES PER HOUR IN THE
HEAVIEST SNOW BANDS. BY MON AFTN...LARGER SCALE FORCING BEGINS TO
DIMINISH AS SHORTWAVE EXITS THE AREA AND Q-VECTOR DIVERGENCE MOVES
IN WITH SUBSIDENCE. INVERSIONS BEGIN TO FALL SHARPLY MON EVENING SO
EVEN THOUGH MAJORITY OF MOIST LAKE EFFECT LAYER REMAINS IN THE
DGZ...EXPECT SNOW INTENSITY TO START TAKING BIGGER HIT. AS THE SFC
RIDGE OVER THE NORTHERN PLAINS ATTEMPTS TO MOVE MORE NORTH OF LK
SUPERIOR...SFC-H925 WINDS VEER NNW FM NW SO MAY SEE SNOW SHOWERS
MOVE BACK OVER MORE AREAS NEAR LK SUPERIOR. WITH THE NEGATIVE
FACTORS MENTIONED INTENSITY SHOULD BE COMING DOWN BUT WILL KEEP POPS
HIGH FOR MAINLY LIGHT SNOW AMOUNTS. LATE ON MON NIGHT WINDS BACK
MORE NW AGAIN...SO EXPECT LAKE EFFECT TO RETURN TO NW SNOW BELTS BY
TUE MORNING WHERE IT SHOULD REMAIN UNTIL TUE NIGHT IN DIMINISHED
STATE AS WINDS BECOME OFFSHORE AS SFC RIDGE MOVES ACROSS.
AS FOR QPF/SNOW...SIMILAR TO LAST NIGHT RAMPED UP QPF/SNOW COMPARED
TO CONSENSUS AND WPC. GIVEN QPF WHICH EXCEEDED TWO TENTHS OF AN INCH
IN 6 HOURS WHERE HEAVIER SNOW BANDS WERE EXPECTED ALONG WITH SLR/S
25-30:1 YIELDED A 12 HOUR SNOWFALL OF 3-6 INCHES OVER WESTERN UPR
MICHIGAN ON MON WITH AMOUNTS MORE TOWARD 5-8 INCHES OVER
ALGER/NORTHERN SCHOOLCRAFT AND LUCE COUNTIES AS PERSISTENT HIGH
INSTABILITY LAKE EFFECT SETUP IS MORE AFFECTED DIRECTLY BY SHORTWAVE
DROPPING SOUTH ACROSS THE AREA THROUGH AT LEAST MID AFTN ON MON.
BASED ON THE HIGHER THAN EXPECTED SLR/S OF THIS EVENT THUS FAR WOULD
NOT BE SURPRISED TO SEE HIGHER SLR/S AND THUS HIGHER SNOW
AMOUNTS...AT LEAST LOCALLY. COORD WITH SHORT TERM FORECASTER AND
DECIDED TO PUT WARNINGS UP FOR NORTHERN SCHOOLCRAFT AND LUCE
COUNTIES AND EXTEND WESTERN UPR MICHIGAN WARNING THROUGH MON. ADVYS
SURROUND THESE AREAS. NO DOUBT THAT HEADLINES MAY NEED TWEAKING AS
HIGHLY MESOSCALE DETAILS FOR WHERE HEAVIEST SNOW DEVELOPS BECOMES
MORE APPARENT TONIGHT INTO MONDAY MORNING.
REST OF EXTENDED FEATURES A WARMING TREND MID TO LATE THIS WEEK. MAY
SEE SOME READINGS NEAR 30 DEGREES AGAIN BY NEXT WEEKEND. WEAK
SHORTWAVE CROSSING WESTERN GREAT LAKES ON WED. A LOT OF MID LEVEL
MOISTURE BUT LOW-LEVEL MOISTURE IS LACKING DUE TO ARCTIC HIGH VCNTY
OF UPPER GREAT LAKES. RAN WITH SLIGHT CHANCE POPS SPREADING FM WEST
TO EAST. BEST CHANCE OF SNOW WILL BE OVER KEWEENAW DUE TO THE
FORCING FM THE SYSTEM AND ENOUGH INSTABILITY FOR LAKE ENHANCED SNOW.
INVERSIONS STAY AT 5KFT OR LESS SO NOT EXPECTING HEAVIER SNOW.
ADDITIONAL SHORTWAVE MOVES THROUGH WED NIGHT INTO THU WITH WEAK
TROUGH PASSAGE TIED TO IT. MAY SEE SNOW SHOWERS INCREASING LATE THIS
WEEK CLOSER TO LK SUPERIOR THOUGH TEMPS BARELY BOTTOM OUT AT -
15C...SO LAKE EFFECT SHOULD BE ON THE LIGHTER SIDE WITH LAKE TEMPS 2-
3C.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 634 AM EST SUN JAN 17 2016
AT KIWD/KCMX...NW FLOW LAKE EFFECT CONTINUES THROUGH THE PERIOD.
EXPECT IFR VSBY DURING THE HEAVIER SNOW BANDS AT IWD TODAY...BUT
WILL STAY MVFR FOR THE MOST PART TONIGHT. IFR/LIFR VSBY WILL
CONTINUE AT KCMX THROUGH THIS FORECAST PERIOD AND THIS WILL BE A
VARIABLE CONDITION.
AT KSAW...OTHER THAN A BRIEF PERIOD OF MVFR CIGS THIS AFTERNOON...EXPECT
VFR CONDITIONS TO PREVAIL. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 550 AM EST SUN JAN 17 2016
A LOW MOVING FROM SOUTHERN ONTARIO TO QUEBEC WILL BRING COLDER AIR
ACROSS LK SUPERIOR THROUGH THE WEEKEND. BEHIND THE LOW...A TROUGH
WILL REMAIN FAIRLY STATIONARY OVER SOUTHERN LAKE SUPERIOR INTO EARLY
TUESDAY...KEEPING WIND GUSTS BETWEEN 25-30KTS WITH HIGHER GALE FORCE
GUSTS TO 35 KNOTS POSSIBLE OVER EASTERN LAKE SUPERIOR LATE THIS
AFTERNOON INTO TONIGHT. IN ADDITION...HEAVY FREEZING SPRAY IS
EXPECTED TODAY INTO MONDAY. WINDS ARE EXPECTED TO SLOWLY DIMINISH
TOWARDS THE MIDDLE OF NEXT WEEK...AS HIGH PRESSURE MOVES OVER THE
UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST MONDAY FOR MIZ002-003-
006-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ013.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ014-084.
WIND CHILL ADVISORY UNTIL NOON CST MONDAY FOR MIZ009-010.
LAKE EFFECT SNOW WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ005.
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ007.
LAKE EFFECT SNOW WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST
MONDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST MONDAY FOR
LSZ263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
550 AM EST SUN JAN 17 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 550 AM EST SUN JAN 17 2016
LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A COLD MID/UPPER LEVEL
LOW MOVING INTO NW LAKE SUPERIOR. AT THE SFC...LAKE INDUCED TROUGH
HAS KEPT WINDS MORE NORTHERLY OVER LAKE SUPERIOR WHILE OVER UPPER MI
WINDS ARE MORE WEST TO NORTHWEST. RESULTING STRONG LOW LEVEL
CONVERGENCE FROM LAKE INDUCED TROF AND ENHANCEMENT ASSOC WITH MID-
UPR LEVEL LOW HAS RESULTED IN VERY INTENSE AND HEAVY LES BANDS INTO
ALGER AND FAR EASTERN MARQUETTE COUNTIES. REPORTS FROM ALGER COUNTY
SHERIFF IN MUNISING ESTIMATED AROUND A FOOT OF SNOW ACCMULATION
SINCE LATE SATURDAY EVENING WITH SNOWFALL RATES EXCEEDING 3 INCHES
PER HOUR AT TIMES. STRONG CONVERGENCE ALSO SUPPORTING HEAVY SNOW
BAND INTO ONTONAGON WITH SIX INCHES THIS LAST EVENING.
TODAY INTO TONIGHT...GIVEN STRONG LOW-LEVEL CONVERGENCE IN PLACE
WITH DEEP CYCLONIC N-NW FLOW AND ENHANCEMENT FROM MID-UPPER LEVEL
LOW...EXPECT HEAVY LES BANDS TO CONTINUE INTO THE LATE MORNING HOURS
FOR FAR ERN MARQUETTE COUNTY...SO DECIDED TO ISSUED A LES WARNING.
BACKING OF WINDS BEHIND PASSAGE OF SFC TROUGH SOUTH THROUGH ERN
UPPER MI THIS MORNING WILL PUSH HEAVY LES BAND OUT OF ERN MQT COUNTY
AND INTO ALGER AND NRN SCHOOLCRAFT COUNTY. STRONG LOW-LVL
CONVERGENCE SETTING UP OVER ALGER...NRN SCHOOLCRAFT AND COUNTIES
FROM PERSISTENT LAKE INDUCED TROF COMBINED WITH POTENTIAL
ENHANCEMENT FROM SHORTWAVE ROTATING SOUTH ACROSS ERN LAKE SUPERIOR
ON MONDAY WILL CONTINUE FAVORABLE ENVIRONMENT FOR HEAVY LES BANDS.
MODEL SOUNDINGS SUGGEST LAKE INDUCED CAPE NEAR 1000 J/KG AND
EQUILIBRIUM LEVEL TO NEAR 13 KFT WITH DGZ STILL FAVORABLY PLACED
WITHIN CONVECTIVE BOUNDARY LAYER YIELDING 25-30/1 SLR/S. THESE
CONDITIONS COULD EASILY SUPPORT HEAVY LES BANDS WITH SNOWFALL RATES
ON ORDER OF 1 TO 2 INCHES PER HOUR WITHIN MORE INTENSE BANDS FOR
ALGER...NRN SCHOOLCRAFT INTO LUCE COUNTIES. THUS...HAVE DECIDED TO
UPGRADE TO LES WARNINGS FOR NRN SCHOOLCRAFT AND LUCE COUNTIES
CONTINUING THROUGH MONDAY CONSISTENT WITH WARNING ALREADY IN PLACE
FOR ALGER COUNTY. SOME AREAS ACROSS ALGER AND NRN SCHOOLCRAFT COULD
SEE AN ADDITIONAL 20 INCHES OF FRESH SNOWFALL THROUGH MONDAY.
DECIDED TO ISSUE A LES ADVISORY FOR DELTA COUNTY...MAINLY OVER THE
NE PORTION WHERE MODERATE SNOW COULD ACCMULATE UP TO 6 INCHES TODAY.
ALSO ISSUED AN ADVISORY FOR SRN SCHOOLCRAFT TODAY INTO MONDAY AS
AREAS NEAR GERMFASK TO STEUBEN COULD APPROACH 8 TO MAYBE 12 INCHES
OF LES ACCUMULATION.
AS FOR WESTERN COUNTIES...GIVEN REPORT OF HEAVY SNOW IN CITY OF
ONTONAGON AND PERSISTENT STRONG LOW-LVL CONVERGENCE INTO ONTONAGON
AND TWIN LAKES PORTION OF NRN HOUGHTON COUNTY HAVE ALSO DECIDED TO
EXTEND LES WARNING FOR THESE TWO COUNTIES THROUGH MONDAY AS WELL.
BELIEVE STRONG LOW-LVL CONVERGENCE AND DEEP CYCLONIC NW FLOW WILL
OVERCOME SLIGHTLY LESS FAVORABLE DENDRITIC SNOW GROWTH. WOULD NOT BE
SURPRISED TO SEE SEVERAL LOCATIONS APPROACH A FOOT OF ADDITIONAL
SNOWFALL ESPECIALLY OVER PORCUPINE MTNS AND TWIN LAKES AREAS. IN
TURN ALSO DECIDED TO EXTEND LES ADVISORIES FOR SRN HOUGHTON FOR
ADDITIONAL ACCUMULATION OF 4 TO 8 INCHES THROUGH MONDAY.
THE VERY COLD AIR MOVING INTO INTERIOR LOCATIONS WILL DROP WIND
CHILLS INTO THE -20 TO -30 RANGE NEAR THE WI BORDER FROM IRONWOOD TO
CRYSTAL FALLS EARLY THIS MORNING AND AGAIN TONIGHT WHERE A WIND
CHILL ADVY WAS ISSUED. EXPECT ENOUGH LAKE MODERATION FARTHER NORTH
FOR WIND CHILLS MAINLY IN THE -10 TO -20 RANGE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 547 AM EST SUN JAN 17 2016
...LAKE EFFECT SNOW GRADUALLY DIMINISHES MON NIGHT INTO TUE...
UPPER TROUGH OVER THE GREAT LAKES MOVES OVER FAR EASTERN CANADA
EARLY THIS WEEK AND OFF ACROSS THE NORTH ATLANTIC BY WED WHILE
AMPLFIED ZONAL FLOW DEVELOPS OVER THE CONUS. COLD AIR WITH H85 TEMPS
DOWN TO -22C ON MON MORNING EASES BY TUE AND WED AS H85 TEMPS RISE TO
-14C BY LATE TUE INTO WED. LAKE INDUCED TROUGHING PERSISTS THROUGH
MONDAY...BUT UNLIKE THIS MORNING WITH MESOLOW ON THE
TROUGH...APPEARS THAT OVERALL RISING HEIGHTS ALOFT WILL RESULT IN
MORE OF A STEADY STATE CONVERGENT NW FLOW ON MONDAY....FOCUSING OVER
ALGER THROUGH LUCE COUNTIES. SOUNDINGS SHOW SLOWLY DIMINISHING
INSTABILITY...BUT STILL LOOKING AT INVERSIONS NEAR 5KFT OVER WESTERN
CWA AND NEAR 10KFT OVER EAST CWA. SHORTWAVE AND DEEP LAYER FORCING
DROPPING ACROSS LK SUPERIOR AND UPR MICHIGAN...ESPECIALLY EAST HALF
WILL CONTINUE TO LEAD TO HEAVY LAKE ENHANCED SNOW WITH SNOW RATES
OVER 1 INCH PER HOUR. BASED ON HOW THIS EVENT HAS WENT THUS FAR
THOUGH WITH TREMENDOUS HOURLY SNOW RATES AIDED IN LARGE PART BY VERY
HIGH SLR/S OVER 30:1...SHOULD SEE RATES 1-3 INCHES PER HOUR IN THE
HEAVIEST SNOW BANDS. BY MON AFTN...LARGER SCALE FORCING BEGINS TO
DIMINISH AS SHORTWAVE EXITS THE AREA AND Q-VECTOR DIVERGENCE MOVES
IN WITH SUBSIDENCE. INVERSIONS BEGIN TO FALL SHARPLY MON EVENING SO
EVEN THOUGH MAJORITY OF MOIST LAKE EFFECT LAYER REMAINS IN THE
DGZ...EXPECT SNOW INTENSITY TO START TAKING BIGGER HIT. AS THE SFC
RIDGE OVER THE NORTHERN PLAINS ATTEMPTS TO MOVE MORE NORTH OF LK
SUPERIOR...SFC-H925 WINDS VEER NNW FM NW SO MAY SEE SNOW SHOWERS
MOVE BACK OVER MORE AREAS NEAR LK SUPERIOR. WITH THE NEGATIVE
FACTORS MENTIONED INTENSITY SHOULD BE COMING DOWN BUT WILL KEEP POPS
HIGH FOR MAINLY LIGHT SNOW AMOUNTS. LATE ON MON NIGHT WINDS BACK
MORE NW AGAIN...SO EXPECT LAKE EFFECT TO RETURN TO NW SNOW BELTS BY
TUE MORNING WHERE IT SHOULD REMAIN UNTIL TUE NIGHT IN DIMINISHED
STATE AS WINDS BECOME OFFSHORE AS SFC RIDGE MOVES ACROSS.
AS FOR QPF/SNOW...SIMILAR TO LAST NIGHT RAMPED UP QPF/SNOW COMPARED
TO CONSENSUS AND WPC. GIVEN QPF WHICH EXCEEDED TWO TENTHS OF AN INCH
IN 6 HOURS WHERE HEAVIER SNOW BANDS WERE EXPECTED ALONG WITH SLR/S
25-30:1 YIELDED A 12 HOUR SNOWFALL OF 3-6 INCHES OVER WESTERN UPR
MICHIGAN ON MON WITH AMOUNTS MORE TOWARD 5-8 INCHES OVER
ALGER/NORTHERN SCHOOLCRAFT AND LUCE COUNTIES AS PERSISTENT HIGH
INSTABILITY LAKE EFFECT SETUP IS MORE AFFECTED DIRECTLY BY SHORTWAVE
DROPPING SOUTH ACROSS THE AREA THROUGH AT LEAST MID AFTN ON MON.
BASED ON THE HIGHER THAN EXPECTED SLR/S OF THIS EVENT THUS FAR WOULD
NOT BE SURPRISED TO SEE HIGHER SLR/S AND THUS HIGHER SNOW
AMOUNTS...AT LEAST LOCALLY. COORD WITH SHORT TERM FORECASTER AND
DECIDED TO PUT WARNINGS UP FOR NORTHERN SCHOOLCRAFT AND LUCE
COUNTIES AND EXTEND WESTERN UPR MICHIGAN WARNING THROUGH MON. ADVYS
SURROUND THESE AREAS. NO DOUBT THAT HEADLINES MAY NEED TWEAKING AS
HIGHLY MESOSCALE DETAILS FOR WHERE HEAVIEST SNOW DEVELOPS BECOMES
MORE APPARENT TONIGHT INTO MONDAY MORNING.
REST OF EXTENDED FEATURES A WARMING TREND MID TO LATE THIS WEEK. MAY
SEE SOME READINGS NEAR 30 DEGREES AGAIN BY NEXT WEEKEND. WEAK
SHORTWAVE CROSSING WESTERN GREAT LAKES ON WED. A LOT OF MID LEVEL
MOISTURE BUT LOW-LEVEL MOISTURE IS LACKING DUE TO ARCTIC HIGH VCNTY
OF UPPER GREAT LAKES. RAN WITH SLIGHT CHANCE POPS SPREADING FM WEST
TO EAST. BEST CHANCE OF SNOW WILL BE OVER KEWEENAW DUE TO THE
FORCING FM THE SYSTEM AND ENOUGH INSTABILITY FOR LAKE ENHANCED SNOW.
INVERSIONS STAY AT 5KFT OR LESS SO NOT EXPECTING HEAVIER SNOW.
ADDITIONAL SHORTWAVE MOVES THROUGH WED NIGHT INTO THU WITH WEAK
TROUGH PASSAGE TIED TO IT. MAY SEE SNOW SHOWERS INCREASING LATE THIS
WEEK CLOSER TO LK SUPERIOR THOUGH TEMPS BARELY BOTTOM OUT AT -
15C...SO LAKE EFFECT SHOULD BE ON THE LIGHTER SIDE WITH LAKE TEMPS 2-
3C.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 124 AM EST SUN JAN 17 2016
AT KIWD/KCMX...NW FLOW LAKE EFFECT CONTINUES THROUGH THE WEEKEND.
EXPECT IFR VSBY DURING THE HEAVIER SNOW BANDS AT IWD...BUT WILL STAY
MVFR FOR THE MOST PART. IFR/LIFR VSBY AT CMX WILL CONTINUE THROUGH
THIS FORECAST PERIOD AND THIS WILL BE A VARIABLE CONDITION.
AT KSAW...MVFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE FORECAST
PERIOD WITH THE LAKE EFFECT SNOW SHOWERS STAYING MOSTLY TO THE EAST.
ONLY EXCEPTION WILL BE IFR CONDITIONS THROUGH THIS MORNING WITH
LIGHT LAKE ENHANCED SNOW CONTINUING...BUT VISIBILITY IN THE SNOW
WILL BE HIGHLY VARIABLE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 550 AM EST SUN JAN 17 2016
A LOW MOVING FROM SOUTHERN ONTARIO TO QUEBEC WILL BRING COLDER AIR
ACROSS LK SUPERIOR THROUGH THE WEEKEND. BEHIND THE LOW...A TROUGH
WILL REMAIN FAIRLY STATIONARY OVER SOUTHERN LAKE SUPERIOR INTO EARLY
TUESDAY...KEEPING WIND GUSTS BETWEEN 25-30KTS WITH HIGHER GALE FORCE
GUSTS TO 35 KNOTS POSSIBLE OVER EASTERN LAKE SUPERIOR LATE THIS
AFTERNOON INTO TONIGHT. IN ADDITION...HEAVY FREEZING SPRAY IS
EXPECTED TODAY INTO MONDAY. WINDS ARE EXPECTED TO SLOWLY DIMINISH
TOWARDS THE MIDDLE OF NEXT WEEK...AS HIGH PRESSURE MOVES OVER THE
UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST MONDAY FOR MIZ002-003-
006-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ013.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ014-084.
WIND CHILL ADVISORY UNTIL NOON CST MONDAY FOR MIZ009-010.
LAKE EFFECT SNOW WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ005.
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ007.
LAKE EFFECT SNOW WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST
MONDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST MONDAY FOR
LSZ263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
548 AM EST SUN JAN 17 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 434 PM EST SAT JAN 16 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A COLD MID/UPPER LEVEL LOW
JUST NE OF WINNIPEG. AT THE SFC...WINDS WERE BACKING AHEAD OF THE
LOW WHICH HAS PUSHED THE HEAVIER LES BAND IN ERN LAKE SUPERIOR TO
THE E MUNSING. LAKE INDUCED TROUGHING EXTENDED FROM SRN INTO W CNTRL
LAKE SUPERIOR RESULTING IN THE STRONGEST LOW LEVEL CONV INTO THE
KEWEENAW NEAR HOUGHTON WHERE A VERY HEAVY LES BAND HAS PRODUCED
HIGHER SNOWFALL RATES OF A FEW INCHES PER HOUR.
TONIGHT...DEEP COLD AIR WILL CONTINUE TO SETTLE OVER THE REGION
TONIGHT WITH 850 MB TEMPS INTO THE -21C TO -25C RANGE AND 700 MB
TEMPS TO AROUND -30C. THE VERY STRONG INSTABILITY WITH LAKE INDUCED
CAPE TO 1K J/KG AND EQUILLIBRIUM HEIGHTS TO 14K FT WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF INTENSE LES BANDS. THE STRONG CONVECTION
OVER THE LAKE WILL ALSO HELP TO KEEP THE DGZ IN THE CONVECTIVE LAYER
WITH FLUFFY SNOW SLR VALUES TO AT LEAST 25/1.
AS THE MID LEVEL LOW MOVES INTO LAKE SUPERIOR...THE MODELS SUGGEST
THAT THE TROUGH TO NEAR CMX WILL GRADUALLY SINK TO THE SOUTH.
SO...ALTHOUGH HIGHER SNOWFALL RATES WILL CONTINUE...THE HEAVIER
BANDS ARE NOT EXPECTED TO REMAIN IN PLACE FOR AN EXTENDED PERIOD.
HOWEVER...ADDITIONAL SNOW AMOUNTS OF 4 TO 8 INCHES ARE EXPECTED
TONIGHT...HEAVIEST FROM CMX TO MASS CITY AND THE PORCUPINES.
OVER THE EAST...THE HEAVIEST SNOW THIS EVENING IS EXPECTED NEAR
LAKE SUPERIOR CLOSER TO PICTURED ROCKS AND GRAND MARAIS. THE HIGH
RES MODELS HAVE BEEN CONSISTENT IN SHOWING A SHARP TROUGH OR MESO LOW
DEVELOPING OVER S CNTRL LAKE SUPERIOR AND SLIDING INTO ALGER COUNTY.
STRONG LOW LEVEL CONV ASSOCIATED ON THE WRN EDGE OF THIS FEATURE WILL
BRING HEAVY LES INTO MAINLY ALGER COUNTY BTWN 06Z-12Z WITH CONTINUED
HEAVIER NNW TO NW FLOW LES BANDS SUN MORNING. THERE IS MORE
UNCERTAINTY ON HOW FAR WEST THE BAND WILL MOVE. LAND BREEZE
DEVELOPMENT SHOULD BE STRONG ENOUGH TO KEEP THE STRONGEST LES EAST OF
MARQUETTE WITH ONLY SOME LIGHTER BANDS ON THE EDGE OF THE LOW FARTHER
TO THE WEST. THE QUICK BURST OF SNOW COULD RESULT IN SNOWFALL RATES
OF 1 TO 3 INCHES PER HOUR FOR A FEW HOURS...ESPECIALY OVER WRN ALGER
COUNTY.
THE VERY COLD AIR MOVING INTO INTERIOR LOCATIONS WILL DROP WIND
CHILLS INTO THE -20 TO -30 RANGE NEAR THE WI BORDER FROM IRONWOOD TO
CRYSTAL FALLS WHERE A WIND CHILL ADVY WAS ISSUED. EXPECT ENOUGH LAKE
MODERATION FARTHER NORTH FOR WIND CHILLS MAINLY IN THE -10 TO -20
RANGE.
SUNDAY...AFTER THE BURST OF HEAVIER SNOW IN THE MORNING OVER MAINLY
WRN ALGER COUNTY...THE LES IS EXPECTED TO EVOLVE INTO LIGHT TO
MODERATE MULTIPLE WIND PARALLEL BANDS WITH A FEW HEAVIER EMBEDDED
BANDS. WHILE MORNING SNOW TOTALS COULD REACH 6 INCHES...AFTERNOON
AMOUNTS SHOULD MAINLY BE IN THE 2 TO 4 INCH RANGE.
OVER THE WEST....A SHORTER FETCH AND LESS FAVORABLE LOW LEVEL CONV
WITH THE SLOWLY BACKING NW FLOW WILL KEEP AMOUNTS IN THE 2 TO 5 INCH
RANGE. IN ADDITION...THE DGZ FALLING CLOSER TO THE LAKE SFC WILL
INHIBIT SNOW GROWTH WITH MAINLY SMALLER FLAKES THAT CAN LEAD TO LOW
VSBY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 547 AM EST SUN JAN 17 2016
...LAKE EFFECT SNOW GRADUALLY DIMINISHES MON NIGHT INTO TUE...
UPPER TROUGH OVER THE GREAT LAKES MOVES OVER FAR EASTERN CANADA
EARLY THIS WEEK AND OFF ACROSS THE NORTH ATLANTIC BY WED WHILE
AMPLFIED ZONAL FLOW DEVELOPS OVER THE CONUS. COLD AIR WITH H85 TEMPS
DOWN TO -22C ON MON MORNING EASES BY TUE AND WED AS H85 TEMPS RISE TO
-14C BY LATE TUE INTO WED. LAKE INDUCED TROUGHING PERSISTS THROUGH
MONDAY...BUT UNLIKE THIS MORNING WITH MESOLOW ON THE
TROUGH...APPEARS THAT OVERALL RISING HEIGHTS ALOFT WILL RESULT IN
MORE OF A STEADY STATE CONVERGENT NW FLOW ON MONDAY....FOCUSING OVER
ALGER THROUGH LUCE COUNTIES. SOUNDINGS SHOW SLOWLY DIMINISHING
INSTABILITY...BUT STILL LOOKING AT INVERSIONS NEAR 5KFT OVER WESTERN
CWA AND NEAR 10KFT OVER EAST CWA. SHORTWAVE AND DEEP LAYER FORCING
DROPPING ACROSS LK SUPERIOR AND UPR MICHIGAN...ESPECIALLY EAST HALF
WILL CONTINUE TO LEAD TO HEAVY LAKE ENHANCED SNOW WITH SNOW RATES
OVER 1 INCH PER HOUR. BASED ON HOW THIS EVENT HAS WENT THUS FAR
THOUGH WITH TREMENDOUS HOURLY SNOW RATES AIDED IN LARGE PART BY VERY
HIGH SLR/S OVER 30:1...SHOULD SEE RATES 1-3 INCHES PER HOUR IN THE
HEAVIEST SNOW BANDS. BY MON AFTN...LARGER SCALE FORCING BEGINS TO
DIMINISH AS SHORTWAVE EXITS THE AREA AND Q-VECTOR DIVERGENCE MOVES
IN WITH SUBSIDENCE. INVERSIONS BEGIN TO FALL SHARPLY MON EVENING SO
EVEN THOUGH MAJORITY OF MOIST LAKE EFFECT LAYER REMAINS IN THE
DGZ...EXPECT SNOW INTENSITY TO START TAKING BIGGER HIT. AS THE SFC
RIDGE OVER THE NORTHERN PLAINS ATTEMPTS TO MOVE MORE NORTH OF LK
SUPERIOR...SFC-H925 WINDS VEER NNW FM NW SO MAY SEE SNOW SHOWERS
MOVE BACK OVER MORE AREAS NEAR LK SUPERIOR. WITH THE NEGATIVE
FACTORS MENTIONED INTENSITY SHOULD BE COMING DOWN BUT WILL KEEP POPS
HIGH FOR MAINLY LIGHT SNOW AMOUNTS. LATE ON MON NIGHT WINDS BACK
MORE NW AGAIN...SO EXPECT LAKE EFFECT TO RETURN TO NW SNOW BELTS BY
TUE MORNING WHERE IT SHOULD REMAIN UNTIL TUE NIGHT IN DIMINISHED
STATE AS WINDS BECOME OFFSHORE AS SFC RIDGE MOVES ACROSS.
AS FOR QPF/SNOW...SIMILAR TO LAST NIGHT RAMPED UP QPF/SNOW COMPARED
TO CONSENSUS AND WPC. GIVEN QPF WHICH EXCEEDED TWO TENTHS OF AN INCH
IN 6 HOURS WHERE HEAVIER SNOW BANDS WERE EXPECTED ALONG WITH SLR/S
25-30:1 YIELDED A 12 HOUR SNOWFALL OF 3-6 INCHES OVER WESTERN UPR
MICHIGAN ON MON WITH AMOUNTS MORE TOWARD 5-8 INCHES OVER
ALGER/NORTHERN SCHOOLCRAFT AND LUCE COUNTIES AS PERSISTENT HIGH
INSTABILITY LAKE EFFECT SETUP IS MORE AFFECTED DIRECTLY BY SHORTWAVE
DROPPING SOUTH ACROSS THE AREA THROUGH AT LEAST MID AFTN ON MON.
BASED ON THE HIGHER THAN EXPECTED SLR/S OF THIS EVENT THUS FAR WOULD
NOT BE SURPRISED TO SEE HIGHER SLR/S AND THUS HIGHER SNOW
AMOUNTS...AT LEAST LOCALLY. COORD WITH SHORT TERM FORECASTER AND
DECIDED TO PUT WARNINGS UP FOR NORTHERN SCHOOLCRAFT AND LUCE
COUNTIES AND EXTEND WESTERN UPR MICHIGAN WARNING THROUGH MON. ADVYS
SURROUND THESE AREAS. NO DOUBT THAT HEADLINES MAY NEED TWEAKING AS
HIGHLY MESOSCALE DETAILS FOR WHERE HEAVIEST SNOW DEVELOPS BECOMES
MORE APPARENT TONIGHT INTO MONDAY MORNING.
REST OF EXTENDED FEATURES A WARMING TREND MID TO LATE THIS WEEK. MAY
SEE SOME READINGS NEAR 30 DEGREES AGAIN BY NEXT WEEKEND. WEAK
SHORTWAVE CROSSING WESTERN GREAT LAKES ON WED. A LOT OF MID LEVEL
MOISTURE BUT LOW-LEVEL MOISTURE IS LACKING DUE TO ARCTIC HIGH VCNTY
OF UPPER GREAT LAKES. RAN WITH SLIGHT CHANCE POPS SPREADING FM WEST
TO EAST. BEST CHANCE OF SNOW WILL BE OVER KEWEENAW DUE TO THE
FORCING FM THE SYSTEM AND ENOUGH INSTABILITY FOR LAKE ENHANCED SNOW.
INVERSIONS STAY AT 5KFT OR LESS SO NOT EXPECTING HEAVIER SNOW.
ADDITIONAL SHORTWAVE MOVES THROUGH WED NIGHT INTO THU WITH WEAK
TROUGH PASSAGE TIED TO IT. MAY SEE SNOW SHOWERS INCREASING LATE THIS
WEEK CLOSER TO LK SUPERIOR THOUGH TEMPS BARELY BOTTOM OUT AT -
15C...SO LAKE EFFECT SHOULD BE ON THE LIGHTER SIDE WITH LAKE TEMPS 2-
3C.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 124 AM EST SUN JAN 17 2016
AT KIWD/KCMX...NW FLOW LAKE EFFECT CONTINUES THROUGH THE WEEKEND.
EXPECT IFR VSBY DURING THE HEAVIER SNOW BANDS AT IWD...BUT WILL STAY
MVFR FOR THE MOST PART. IFR/LIFR VSBY AT CMX WILL CONTINUE THROUGH
THIS FORECAST PERIOD AND THIS WILL BE A VARIABLE CONDITION.
AT KSAW...MVFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE FORECAST
PERIOD WITH THE LAKE EFFECT SNOW SHOWERS STAYING MOSTLY TO THE EAST.
ONLY EXCEPTION WILL BE IFR CONDITIONS THROUGH THIS MORNING WITH
LIGHT LAKE ENHANCED SNOW CONTINUING...BUT VISIBILITY IN THE SNOW
WILL BE HIGHLY VARIABLE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 434 PM EST SAT JAN 16 2016
A LOW MOVING FROM SOUTHERN ONTARIO TO QUEBEC WILL BRING COLDER AIR
ACROSS LK SUPERIOR THROUGH THE WEEKEND. BEHIND THE LOW...A TROUGH
WILL REMAIN FAIRLY STATIONARY OVER SOUTHERN LAKE SUPERIOR INTO
TUESDAY...KEEPING WIND GUSTS BETWEEN 25-30KTS. IN ADDITION...THERE
IS THE POTENTIAL FOR HEAVY FREEZING SPRAY SUNDAY INTO MONDAY. WINDS
ARE EXPECTED TO SLOWLY DIMINISH TOWARDS THE MIDDLE OF NEXT WEEK...AS
HIGH PRESSURE MOVES OVER THE UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST MONDAY FOR MIZ002-003-
006-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ013.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ014-084.
WIND CHILL ADVISORY UNTIL NOON CST MONDAY FOR MIZ009-010.
LAKE EFFECT SNOW WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ005.
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ007.
LAKE EFFECT SNOW WARNING FROM 4 PM THIS AFTERNOON TO 7 PM EST
MONDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST MONDAY FOR
LSZ263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
125 AM EST SUN JAN 17 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 434 PM EST SAT JAN 16 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A COLD MID/UPPER LEVEL LOW
JUST NE OF WINNIPEG. AT THE SFC...WINDS WERE BACKING AHEAD OF THE
LOW WHICH HAS PUSHED THE HEAVIER LES BAND IN ERN LAKE SUPERIOR TO
THE E MUNSING. LAKE INDUCED TROUGHING EXTENDED FROM SRN INTO W CNTRL
LAKE SUPERIOR RESULTING IN THE STRONGEST LOW LEVEL CONV INTO THE
KEWEENAW NEAR HOUGHTON WHERE A VERY HEAVY LES BAND HAS PRODUCED
HIGHER SNOWFALL RATES OF A FEW INCHES PER HOUR.
TONIGHT...DEEP COLD AIR WILL CONTINUE TO SETTLE OVER THE REGION
TONIGHT WITH 850 MB TEMPS INTO THE -21C TO -25C RANGE AND 700 MB
TEMPS TO AROUND -30C. THE VERY STRONG INSTABILITY WITH LAKE INDUCED
CAPE TO 1K J/KG AND EQUILLIBRIUM HEIGHTS TO 14K FT WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF INTENSE LES BANDS. THE STRONG CONVECTION
OVER THE LAKE WILL ALSO HELP TO KEEP THE DGZ IN THE CONVECTIVE LAYER
WITH FLUFFY SNOW SLR VALUES TO AT LEAST 25/1.
AS THE MID LEVEL LOW MOVES INTO LAKE SUPERIOR...THE MODELS SUGGEST
THAT THE TROUGH TO NEAR CMX WILL GRADUALLY SINK TO THE SOUTH.
SO...ALTHOUGH HIGHER SNOWFALL RATES WILL CONTINUE...THE HEAVIER
BANDS ARE NOT EXPECTED TO REMAIN IN PLACE FOR AN EXTENDED PERIOD.
HOWEVER...ADDITIONAL SNOW AMOUNTS OF 4 TO 8 INCHES ARE EXPECTED
TONIGHT...HEAVIEST FROM CMX TO MASS CITY AND THE PORCUPINES.
OVER THE EAST...THE HEAVIEST SNOW THIS EVENING IS EXPECTED NEAR
LAKE SUPERIOR CLOSER TO PICTURED ROCKS AND GRAND MARAIS. THE HIGH
RES MODELS HAVE BEEN CONSISTENT IN SHOWING A SHARP TROUGH OR MESO LOW
DEVELOPING OVER S CNTRL LAKE SUPERIOR AND SLIDING INTO ALGER COUNTY.
STRONG LOW LEVEL CONV ASSOCIATED ON THE WRN EDGE OF THIS FEATURE WILL
BRING HEAVY LES INTO MAINLY ALGER COUNTY BTWN 06Z-12Z WITH CONTINUED
HEAVIER NNW TO NW FLOW LES BANDS SUN MORNING. THERE IS MORE
UNCERTAINTY ON HOW FAR WEST THE BAND WILL MOVE. LAND BREEZE
DEVELOPMENT SHOULD BE STRONG ENOUGH TO KEEP THE STRONGEST LES EAST OF
MARQUETTE WITH ONLY SOME LIGHTER BANDS ON THE EDGE OF THE LOW FARTHER
TO THE WEST. THE QUICK BURST OF SNOW COULD RESULT IN SNOWFALL RATES
OF 1 TO 3 INCHES PER HOUR FOR A FEW HOURS...ESPECIALY OVER WRN ALGER
COUNTY.
THE VERY COLD AIR MOVING INTO INTERIOR LOCATIONS WILL DROP WIND
CHILLS INTO THE -20 TO -30 RANGE NEAR THE WI BORDER FROM IRONWOOD TO
CRYSTAL FALLS WHERE A WIND CHILL ADVY WAS ISSUED. EXPECT ENOUGH LAKE
MODERATION FARTHER NORTH FOR WIND CHILLS MAINLY IN THE -10 TO -20
RANGE.
SUNDAY...AFTER THE BURST OF HEAVIER SNOW IN THE MORNING OVER MAINLY
WRN ALGER COUNTY...THE LES IS EXPECTED TO EVOLVE INTO LIGHT TO
MODERATE MULTIPLE WIND PARALLEL BANDS WITH A FEW HEAVIER EMBEDDED
BANDS. WHILE MORNING SNOW TOTALS COULD REACH 6 INCHES...AFTERNOON
AMOUNTS SHOULD MAINLY BE IN THE 2 TO 4 INCH RANGE.
OVER THE WEST....A SHORTER FETCH AND LESS FAVORABLE LOW LEVEL CONV
WITH THE SLOWLY BACKING NW FLOW WILL KEEP AMOUNTS IN THE 2 TO 5 INCH
RANGE. IN ADDITION...THE DGZ FALLING CLOSER TO THE LAKE SFC WILL
INHIBIT SNOW GROWTH WITH MAINLY SMALLER FLAKES THAT CAN LEAD TO LOW
VSBY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 409 PM EST SAT JAN 16 2016
MAIN ATTENTION IS ON HEALTHY LES SUN NIGHT AND MON THAT WILL
DIMINISH MON NIGHT AND TUE.
THE UPPER LOW THAT IS BRINGING THIS MASS OF COLD AIR WILL JUST E OF
THE CWA AT 00Z MON...850MB TEMPS WILL BE AROUND -23C TO START SUN
NIGHT. MODERATE TO HEAVY LES WILL BE ONGOING IN THE NW WIND
SNOWBELTS AT 00Z MON...ESPECIALLY IN AREAS E OF MARQUETTE COUNTY.
SHOULD SEE OVERALL STEADY LES SUN NIGHT INTO MUCH OF MON...WITH
DIMINISHING STARTING IN THE AFTERNOON W AND IN THE EVENING E AS THE
UPPER LOW MOVES AWAY...850MB TEMPS WARM BY 4-5 DEGREES AND WARMER
AND DRIER AIR MOVES IN ABOVE THE MOIST LAKE INFLUENCED LAYER. LAKE
INDUCED EQUILIBRIUM LEVELS SHOULD RANGE FROM 10KFT AT CMX TO 15KFT
AT GRAND MARAIS AT 00Z SUN...LOWERING BY AROUND 3KFT BY 12Z
SUN...THEN GRADUALLY DROPPING TO AROUND 6KFT OVER MOST OF THE LAKE
BY 00Z TUE. A SHORTWAVE DROPPING ACROSS LAKE SUPERIOR MON AFTERNOON
SHOULD HELP OFFSET SOME OF THE AFOREMENTIONED INCREASINGLY
UNFAVORABLE FEATURES. BETWEEN 00Z MON AND 00Z TUE...EXPECT ANOTHER 3-
5 INCHES OVER NW UPPER MI AND 6-10 INCHES OVER THE NW WIND FAVORED
AREAS OF ERN UPPER MI (MAINLY E OF MARQUETTE COUNTY). EXPECT WINDS
TO INCREASE SUN NIGHT INTO MON...WITH GUSTS UP TO 35MPH ALONG THE
SHORELINES E OF MARQUETTE AND 25-30MPH ELSEWHERE NEAR LAKE SUPERIOR.
THIS WILL PRODUCE QUITE A BIT OF BLOWING SNOW...ESPECIALLY ALONG M-
28 E OF HARVEY (NOT AS MUCH AS IF THERE WAS SIGNIFICANT ICE COVER ON
LAKE SUPERIOR AS IN YEARS PAST). MON NIGHT WILL SEE MODERATE SNOW
POTENTIAL EARLY...BUT INVERSIONS WILL BE LOWERING AND 850MB TEMPS
INCREASING TO AROUND -14C AS A SFC RIDGE MOVES TO W OF LAKE
SUPERIOR. LES WILL CONTINUE TO DIMINISH ON TUE...WITH ONLY LIGHT LES
EXPECTED...BUT WILL NOT COMPLETELY END.
SUN NIGHT AND MON MORNING WILL ALSO BE QUITE COLD WITH LOWS IN THE
SINGLE DIGITS ABOVE AND BELOW ZERO IN MOST PLACES...AROUND -10 ALONG
THE WI BORDER IN GOGEBIC COUNTY. RESULTING WIND CHILL VALUES WILL
FALL BELOW -15 OVER MUCH OF THE CENTRAL AND W...DOWN TO -25 TO -30
IN THE COLDEST SPOTS.
AFTER TUE WE COULD SEE A COUPLE SHORTWAVES MOVES THROUGH BEFORE
THU...WHICH MAY OR MAY NOT PRODUCE ANY WIDESPREAD LIGHT SNOW. THERE
IS ENOUGH UNCERTAINTY AND LACK OF SIGNIFICANT CONDITIONS AFTER TUE
TO JUST RUN WITH A CONSENSUS BLEND FOR THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 124 AM EST SUN JAN 17 2016
AT KIWD/KCMX...NW FLOW LAKE EFFECT CONTINUES THROUGH THE WEEKEND.
EXPECT IFR VSBY DURING THE HEAVIER SNOW BANDS AT IWD...BUT WILL STAY
MVFR FOR THE MOST PART. IFR/LIFR VSBY AT CMX WILL CONTINUE THROUGH
THIS FORECAST PERIOD AND THIS WILL BE A VARIABLE CONDITION.
AT KSAW...MVFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE FORECAST
PERIOD WITH THE LAKE EFFECT SNOW SHOWERS STAYING MOSTLY TO THE EAST.
ONLY EXCEPTION WILL BE IFR CONDITIONS THROUGH THIS MORNING WITH
LIGHT LAKE ENHANCED SNOW CONTINUING...BUT VISIBILITY IN THE SNOW
WILL BE HIGHLY VARIABLE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 434 PM EST SAT JAN 16 2016
A LOW MOVING FROM SOUTHERN ONTARIO TO QUEBEC WILL BRING COLDER AIR
ACROSS LK SUPERIOR THROUGH THE WEEKEND. BEHIND THE LOW...A TROUGH
WILL REMAIN FAIRLY STATIONARY OVER SOUTHERN LAKE SUPERIOR INTO
TUESDAY...KEEPING WIND GUSTS BETWEEN 25-30KTS. IN ADDITION...THERE
IS THE POTENTIAL FOR HEAVY FREEZING SPRAY SUNDAY INTO MONDAY. WINDS
ARE EXPECTED TO SLOWLY DIMINISH TOWARDS THE MIDDLE OF NEXT WEEK...AS
HIGH PRESSURE MOVES OVER THE UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ002-003.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-084.
WIND CHILL ADVISORY UNTIL NOON CST MONDAY FOR MIZ009-010.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ007-085.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST MONDAY FOR MIZ006.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 AM THIS MORNING TO 1 PM EST
MONDAY FOR LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1159 PM EST SAT JAN 16 2016
.AVIATION...
LOW VFR CEILINGS IN PLACE...BUT INCREASE IN SNOW SHOWER ACTIVITY
COMING OFF LAKE MICHIGAN WILL ATTEMPT TO SEND CEILINGS AND
CERTAINTY VISIBILITIES IN MVFR CATEGORY. HOWEVER...THE ARCTIC
AIRMASS OVER THE WESTERN GREAT LAKES IS EXTREMELY DRY...AND OUTSIDE
OF ANY OF THE SNOW SHOWER ACTIVITY...VFR CONDITIONS WILL PROBABLY
BE THE RULE TODAY. THE VERY COLD AIRMASS IS ALSO EXPECTED TO LIMIT
SNOW FLAKE SIZE...AND ACCUMULATIONS WILL PROBABLY REMAIN LESS THAN
AN INCH AT THE TERMINALS. GOOD SURGE OF LOW LEVEL COLD ADVECTION
AND DAYTIME MIXING SHOULD TRANSLATE TO SOLID WESTERLY GUSTS REACHING
AROUND 25 KNOTS.
FOR DTW... COULD SEE A SHORT PERIOD OF CEILING FREE SKIES AT THE
START OF THE FORECAST PERIOD...BUT VFR CLOUDS RETURN...WITH AT LEAST
FLURRIES AND PROBABLY SOME LIGHT SNOW SHOWERS SENDING VISIBILITIES
INTO MVFR TOWARD SUNDAY MORNING. ACCUMULATIONS ARE EXPECTED TO
REMAIN LIGHT...LESS THAN 1 INCH. WESTERLY WINDS WILL BE
STRONG...SUSTAINED AROUND 15 KNOTS...WITH GUSTS LIKELY REACHING 25
KNOTS OR SLIGHTLY BETTER BY SUNDAY AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* MEDIUM FOR CEILING AOB 5KFT.
* HIGH FOR SNOW AS PTYPE.
* MODERATE FOR WESTERLY WIND GUSTS EXCEEDING CROSSWIND THRESHOLDS
SUNDAY.
&&
.PREV DISCUSSION...ISSUED 800 PM EST SAT JAN 16 2016
UPDATE...
ARCTIC FRONT WAS POSITIONED FROM ABOUT THE BRIDGE TO MBL TO
CHICAGO. THIS FRONT WILL MOVE THROUGH THE FORECAST AREA AFTER
MIDNIGHT. TOOK OUT THE MENTION OF SNOW SHOWERS UNTIL THE FRONT
GETS CLOSER. AT THE TIME OF FRONTAL PASSAGE...A WEAK WAVE NOTED
OVER IA AND NRN IL...WILL INTERACT WITH THE FRONT. THE 18Z NAM
AND UPDATED RUC SUGGESTS SOME CHANCE OF MINOR QPF FOR AREAS AS FAR
NORTH AS M 46. WILL TAKE THE LATE NIGHT 50 POPS THAT WERE FOCUSED
FARTHER SOUTH AFTER 09Z...AND MOVE THEM TO 06Z TO 12Z AND EXPAND
THEM NORTH TO HIGHWAY M 46.
OTHERWISE FORECAST ON TRACK TONIGHT WITH CLOUDS AND LOW TEMPS. DID
TWEAK THE WIND UP JUST A NOTCH GIVEN THE GRADIENT AND THE COLD
AIR SPILLING INTO LOWER MICHIGAN. THAT COLD AIR APPEARS TO HAVE
SOME ABILITY TO KEEP A MIX LAYER WITH SOME DEPTH.
PREV DISCUSSION...ISSUED 405 PM EST SAT JAN 16 2016
DISCUSSION...
FORECAST FOR THE REMAINDER OF THE HOLIDAY WEEKEND WILL BE DOMINATED
BY AN ARCTIC AIR INTRUSION THAT WILL OCCUR TONIGHT AND SUNDAY AS A
LARGE UPPER LOW SLOWLY TRACKS THROUGH THE GREAT LAKES. THIS WILL
BRING VERY COLD TEMPERATURES...GUSTY WINDS/LOW WIND CHILLS...AND
CHANCES FOR SNOW SHOWERS.
AREA OF ENHANCED LAKE EFFECT...MAINLY IN ONE BAND...WITH CONNECTIONS
TO BOTH LAKE SUPERIOR AND LAKE MICHIGAN THAT AFFECTED PRIMARILY THE
SAGINAW VALLEY EARLY TODAY SHIFTED AS WINDS TURNED MORE WESTERLY.
LIGHT SHOWERS AND FLURRIES HAVE SINCE BEEN MAKING THEIR WAY INTO THE
EASTERN PART OF THE STATE THIS AFTERNOON...WITH LATEST
RADAR/SATELLITE INDICATING MOISTURE IS RELEASING OFF LAKE MICHIGAN.
WHAT IS LEFT OF THE SHOWERS/CLOUDS OVER THE WESTERN PART OF THE
STATE SHOULD MAKE THEIR WAY ACROSS SOUTHEAST MICHIGAN BETWEEN 4PM
AND 8PM. MAY THEN SEE SOME BREAKS OR CLEAR PATCHES IN CLOUDS AS
DRIER AIR EVIDENT ON SATELLITE OVER LAKE MICHIGAN AND EXTENDING BACK
THROUGH WISCONSIN WORKS THROUGH. DRIER AIR IS AT THE LEAD EDGE OF
ARCTIC AIRMASS THAT WILL SPILL INTO THE AREA FOR THE REMAINDER OF
THE WEEKEND. PRECIPITATION IS CURRENTLY NOT OCCURRING UPSTREAM IN
ASSOCIATION WITH THE FRONTAL PASSAGE. GIVEN THIS AIRMASS WILL BE
MOVING OVER A RELATIVELY WARM LAKE MICHIGAN...42 DEGREES PER LATEST
SATELLITE ANALYSIS...AND TEMPS ARE IN THE SINGLE DIGITS BEHIND THE
FRONT...WILL KEEP SOME LOW POPS IN THE FORECAST TO COVER ANY LAKE
EFFECT THAT STREAMS THIS FAR EAST.
UPTICK IN SNOW SHOWER ACTIVITY IS EXPECTED VERY LATE TONIGHT THROUGH
SUNDAY AFTERNOON AS DEEPER MOISTURE ARRIVES...COLD AIR ADVECTION
INCREASES LAKE RESPONSE...AND PVA ASSOCIATED WITH THE UPPER LOW
WORKS ACROSS. COOLING THERMAL FIELDS WILL ALSO ALLOW MOISTURE TO
BECOME BETTER PLACED WITHIN THE DENDRITIC GROWTH ZONE. WEST TO WEST-
NORTHWEST WINDS WILL FAVOR THE SOUTHERN PORTION OF THE FORECAST AREA
FOR LAKE ENHANCED SNOW SHOWERS LATE TONIGHT AND SUNDAY. WITH
PRECIPITATION OCCURRING IN BANDS...ACCUMULATIONS WILL BE HIGHLY
VARIABLE (MAYBE UP TO AN INCH)...AND RAPID FLUCTUATIONS IN VISIBILITY
ARE POSSIBLE UNTIL LATE AFTERNOON WHEN DRIER AIR SHOULD AGAIN WORK
INTO THE SOUTHERN CENTRAL PORTIONS OF THE FORECAST AREA. SURFACE
TROUGH WILL DEEPEN OVER LAKE HURON TONIGHT AND SUNDAY AS THE UPPER
LOW APPROACHES...EVENTUALLY RESULTING IN A COLD FRONT DROPPING SOUTH
INTO THE SOUTH-CENTRAL LOWER MICHIGAN LATE SUNDAY...AND INTO THE
REST OF THE AREA SUNDAY NIGHT. THIS WILL AGAIN BRING CHANCES FOR
SNOW SHOWERS.
MAIN STORY WILL REALLY BE THE ARRIVAL OF MUCH COLDER TEMPERATURES.
THE COLD AIR WILL ALSO COMBINE WITH GUSTY WINDS THROUGH MUCH OF THE
WEEKEND TO PRODUCE SOME OF THE COLDEST WIND CHILLS SO FAR THIS
WINTER. TEMPS FALLING INTO THE TEENS TONIGHT WILL RECOVER LITTLE ON
SUNDAY AS ARCTIC AIRMASS CONTINUES TO SPILL IN. GUSTY WINDS WILL
KEEP WIND CHILLS BELOW ZERO FOR MUCH OF THE AREA BOTH TOMORROW AND
MONDAY (LOW SINGLE DIGITS FOR DETROIT). SINGLE DIGIT LOWS ARE THEN
EXPECTED BOTH SUNDAY AND MONDAY NIGHTS...PRODUCING WIND CHILLS IN
THE -10 TO -15F DEGREE RANGE SUNDAY NIGHT.
TUESDAY THROUGH SUNDAY.
A COUPLE OF WEAK WEATHER SYSTEMS ARE EXPECTED TO MOVE ACROSS
SOUTHEAST MICHIGAN BEGINNING MIDWEEK. THESE SYSTEMS WILL BRING IN
CHANCES FOR FLURRIES AND LIGHT SNOW SHOWERS THROUGH FRIDAY EVENING.
LITTLE TO NO ACCUMULATION IS CURRENTLY ANTICIPATED WITH THESE
SHOWERS. TEMPERATURES WILL GRADUALLY WARM BACK TOWARD THE SEASONAL
NORM BY THE END OF THE FORECAST PERIOD.
MARINE...
AN ARCTIC COLD FRONT WILL MOVE THROUGH THE SOUTHERN GREAT LAKES
TONIGHT AND LEAVE A LOW/SURFACE TROUGH STALLED OVER LAKE SUPERIOR
AND NORTHERN LAKE HURON. THIS WILL KEEP THE STRONGEST WIND FOCUSED
FROM THE SOUTH HALF OF LAKE HURON THROUGH WESTERN LAKE ERIE SUNDAY
AND MONDAY. THE WESTERLY FLOW OVER THE SHORT FETCH OF SOUTHERN LAKE
HURON OPEN WATER FAVORS GUSTS MOSTLY BELOW GALES AND GUSTS AROUND 25
KNOTS OR LESS OVER LAKE ST CLAIR AND THE MICHIGAN WATERS OF LAKE
ERIE. WHILE HEADLINES FOR WIND ARE NOT YET NEEDED...THE ARCTIC AIR
SPILLING OVER THE REGION WILL MAKE FREEZING SPRAY AND ICING A
CONCERN IN THE FORECAST. THE BEST COMBINATION OF WIND...WATER
TEMPERATURE...AND AIR TEMPERATURE ARE ONLY SUPPORTING MODERATE
FREEZING SPRAY IN WESTERLY FLOW OVER U.S. WATERS OVER THE SOUTH HALF
OF LAKE HURON. THIS WILL BE MONITORED ALSO WITHOUT A HEADLINE FOR
NOW.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SF
UPDATE.......RBP
DISCUSSION...HLO/DE
MARINE.......BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1147 PM EST SAT JAN 16 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 434 PM EST SAT JAN 16 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A COLD MID/UPPER LEVEL LOW
JUST NE OF WINNIPEG. AT THE SFC...WINDS WERE BACKING AHEAD OF THE
LOW WHICH HAS PUSHED THE HEAVIER LES BAND IN ERN LAKE SUPERIOR TO
THE E MUNSING. LAKE INDUCED TROUGHING EXTENDED FROM SRN INTO W CNTRL
LAKE SUPERIOR RESULTING IN THE STRONGEST LOW LEVEL CONV INTO THE
KEWEENAW NEAR HOUGHTON WHERE A VERY HEAVY LES BAND HAS PRODUCED
HIGHER SNOWFALL RATES OF A FEW INCHES PER HOUR.
TONIGHT...DEEP COLD AIR WILL CONTINUE TO SETTLE OVER THE REGION
TONIGHT WITH 850 MB TEMPS INTO THE -21C TO -25C RANGE AND 700 MB
TEMPS TO AROUND -30C. THE VERY STRONG INSTABILITY WITH LAKE INDUCED
CAPE TO 1K J/KG AND EQUILLIBRIUM HEIGHTS TO 14K FT WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF INTENSE LES BANDS. THE STRONG CONVECTION
OVER THE LAKE WILL ALSO HELP TO KEEP THE DGZ IN THE CONVECTIVE LAYER
WITH FLUFFY SNOW SLR VALUES TO AT LEAST 25/1.
AS THE MID LEVEL LOW MOVES INTO LAKE SUPERIOR...THE MODELS SUGGEST
THAT THE TROUGH TO NEAR CMX WILL GRADUALLY SINK TO THE SOUTH.
SO...ALTHOUGH HIGHER SNOWFALL RATES WILL CONTINUE...THE HEAVIER
BANDS ARE NOT EXPECTED TO REMAIN IN PLACE FOR AN EXTENDED PERIOD.
HOWEVER...ADDITIONAL SNOW AMOUNTS OF 4 TO 8 INCHES ARE EXPECTED
TONIGHT...HEAVIEST FROM CMX TO MASS CITY AND THE PORCUPINES.
OVER THE EAST...THE HEAVIEST SNOW THIS EVENING IS EXPECTED NEAR
LAKE SUPERIOR CLOSER TO PICTURED ROCKS AND GRAND MARAIS. THE HIGH
RES MODELS HAVE BEEN CONSISTENT IN SHOWING A SHARP TROUGH OR MESO LOW
DEVELOPING OVER S CNTRL LAKE SUPERIOR AND SLIDING INTO ALGER COUNTY.
STRONG LOW LEVEL CONV ASSOCIATED ON THE WRN EDGE OF THIS FEATURE WILL
BRING HEAVY LES INTO MAINLY ALGER COUNTY BTWN 06Z-12Z WITH CONTINUED
HEAVIER NNW TO NW FLOW LES BANDS SUN MORNING. THERE IS MORE
UNCERTAINTY ON HOW FAR WEST THE BAND WILL MOVE. LAND BREEZE
DEVELOPMENT SHOULD BE STRONG ENOUGH TO KEEP THE STRONGEST LES EAST OF
MARQUETTE WITH ONLY SOME LIGHTER BANDS ON THE EDGE OF THE LOW FARTHER
TO THE WEST. THE QUICK BURST OF SNOW COULD RESULT IN SNOWFALL RATES
OF 1 TO 3 INCHES PER HOUR FOR A FEW HOURS...ESPECIALY OVER WRN ALGER
COUNTY.
THE VERY COLD AIR MOVING INTO INTERIOR LOCATIONS WILL DROP WIND
CHILLS INTO THE -20 TO -30 RANGE NEAR THE WI BORDER FROM IRONWOOD TO
CRYSTAL FALLS WHERE A WIND CHILL ADVY WAS ISSUED. EXPECT ENOUGH LAKE
MODERATION FARTHER NORTH FOR WIND CHILLS MAINLY IN THE -10 TO -20
RANGE.
SUNDAY...AFTER THE BURST OF HEAVIER SNOW IN THE MORNING OVER MAINLY
WRN ALGER COUNTY...THE LES IS EXPECTED TO EVOLVE INTO LIGHT TO
MODERATE MULTIPLE WIND PARALLEL BANDS WITH A FEW HEAVIER EMBEDDED
BANDS. WHILE MORNING SNOW TOTALS COULD REACH 6 INCHES...AFTERNOON
AMOUNTS SHOULD MAINLY BE IN THE 2 TO 4 INCH RANGE.
OVER THE WEST....A SHORTER FETCH AND LESS FAVORABLE LOW LEVEL CONV
WITH THE SLOWLY BACKING NW FLOW WILL KEEP AMOUNTS IN THE 2 TO 5 INCH
RANGE. IN ADDITION...THE DGZ FALLING CLOSER TO THE LAKE SFC WILL
INHIBIT SNOW GROWTH WITH MAINLY SMALLER FLAKES THAT CAN LEAD TO LOW
VSBY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 409 PM EST SAT JAN 16 2016
MAIN ATTENTION IS ON HEALTHY LES SUN NIGHT AND MON THAT WILL
DIMINISH MON NIGHT AND TUE.
THE UPPER LOW THAT IS BRINGING THIS MASS OF COLD AIR WILL JUST E OF
THE CWA AT 00Z MON...850MB TEMPS WILL BE AROUND -23C TO START SUN
NIGHT. MODERATE TO HEAVY LES WILL BE ONGOING IN THE NW WIND
SNOWBELTS AT 00Z MON...ESPECIALLY IN AREAS E OF MARQUETTE COUNTY.
SHOULD SEE OVERALL STEADY LES SUN NIGHT INTO MUCH OF MON...WITH
DIMINISHING STARTING IN THE AFTERNOON W AND IN THE EVENING E AS THE
UPPER LOW MOVES AWAY...850MB TEMPS WARM BY 4-5 DEGREES AND WARMER
AND DRIER AIR MOVES IN ABOVE THE MOIST LAKE INFLUENCED LAYER. LAKE
INDUCED EQUILIBRIUM LEVELS SHOULD RANGE FROM 10KFT AT CMX TO 15KFT
AT GRAND MARAIS AT 00Z SUN...LOWERING BY AROUND 3KFT BY 12Z
SUN...THEN GRADUALLY DROPPING TO AROUND 6KFT OVER MOST OF THE LAKE
BY 00Z TUE. A SHORTWAVE DROPPING ACROSS LAKE SUPERIOR MON AFTERNOON
SHOULD HELP OFFSET SOME OF THE AFOREMENTIONED INCREASINGLY
UNFAVORABLE FEATURES. BETWEEN 00Z MON AND 00Z TUE...EXPECT ANOTHER 3-
5 INCHES OVER NW UPPER MI AND 6-10 INCHES OVER THE NW WIND FAVORED
AREAS OF ERN UPPER MI (MAINLY E OF MARQUETTE COUNTY). EXPECT WINDS
TO INCREASE SUN NIGHT INTO MON...WITH GUSTS UP TO 35MPH ALONG THE
SHORELINES E OF MARQUETTE AND 25-30MPH ELSEWHERE NEAR LAKE SUPERIOR.
THIS WILL PRODUCE QUITE A BIT OF BLOWING SNOW...ESPECIALLY ALONG M-
28 E OF HARVEY (NOT AS MUCH AS IF THERE WAS SIGNIFICANT ICE COVER ON
LAKE SUPERIOR AS IN YEARS PAST). MON NIGHT WILL SEE MODERATE SNOW
POTENTIAL EARLY...BUT INVERSIONS WILL BE LOWERING AND 850MB TEMPS
INCREASING TO AROUND -14C AS A SFC RIDGE MOVES TO W OF LAKE
SUPERIOR. LES WILL CONTINUE TO DIMINISH ON TUE...WITH ONLY LIGHT LES
EXPECTED...BUT WILL NOT COMPLETELY END.
SUN NIGHT AND MON MORNING WILL ALSO BE QUITE COLD WITH LOWS IN THE
SINGLE DIGITS ABOVE AND BELOW ZERO IN MOST PLACES...AROUND -10 ALONG
THE WI BORDER IN GOGEBIC COUNTY. RESULTING WIND CHILL VALUES WILL
FALL BELOW -15 OVER MUCH OF THE CENTRAL AND W...DOWN TO -25 TO -30
IN THE COLDEST SPOTS.
AFTER TUE WE COULD SEE A COUPLE SHORTWAVES MOVES THROUGH BEFORE
THU...WHICH MAY OR MAY NOT PRODUCE ANY WIDESPREAD LIGHT SNOW. THERE
IS ENOUGH UNCERTAINTY AND LACK OF SIGNIFICANT CONDITIONS AFTER TUE
TO JUST RUN WITH A CONSENSUS BLEND FOR THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1147 PM EST SAT JAN 16 2016
AT KIWD/KCMX...NW FLOW LAKE EFFECT CONTINUES THROUGH THE WEEKEND.
EXPECT IFR VSBY DURING THE HEAVIER SNOW BANDS AT IWD...BUT WILL STAY
MVFR FOR THE MOST PART. IFR/LIFR VSBY AT CMX WILL CONTINUE THROUGH
THIS FORECAST PERIOD AND THIS WILL BE A VARIABLE CONDITION.
AT KSAW...MVFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE FORECAST
PERIOD WITH THE LAKE EFFECT SNOW SHOWERS STAYING MOSTLY TO THE EAST.
ONLY EXCEPTION WILL BE IFR CONDITIONS THROUGH THIS MORNING WITH
LIGHT LAKE ENHANCED SNOW CONTINUING...BUT VISIBILITY IN THE SNOW
WILL BE HIGHLY VARIABLE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 434 PM EST SAT JAN 16 2016
A LOW MOVING FROM SOUTHERN ONTARIO TO QUEBEC WILL BRING COLDER AIR
ACROSS LK SUPERIOR THROUGH THE WEEKEND. BEHIND THE LOW...A TROUGH
WILL REMAIN FAIRLY STATIONARY OVER SOUTHERN LAKE SUPERIOR INTO
TUESDAY...KEEPING WIND GUSTS BETWEEN 25-30KTS. IN ADDITION...THERE
IS THE POTENTIAL FOR HEAVY FREEZING SPRAY SUNDAY INTO MONDAY. WINDS
ARE EXPECTED TO SLOWLY DIMINISH TOWARDS THE MIDDLE OF NEXT WEEK...AS
HIGH PRESSURE MOVES OVER THE UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST SUNDAY FOR MIZ002-003.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST SUNDAY FOR MIZ001-084.
WIND CHILL ADVISORY UNTIL NOON CST MONDAY FOR MIZ009-010.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ007-085.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST MONDAY FOR MIZ006.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 AM SUNDAY TO 1 PM EST MONDAY
FOR LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
941 PM EST MON JAN 18 2016
.SYNOPSIS...
THE COLDEST TEMPERATURES OF THE WINTER SO FAR WILL OCCUR ACROSS
THE CAROLINAS TONIGHT. HIGH PRESSURE WILL BUILD ACROSS THE AREA
THROUGH WEDNESDAY AND MOVE OFF THE COAST ON THURSDAY. LOW
PRESSURE WILL MOVE FROM THE GULF COAST STATES TO THE CAROLINAS ON
FRIDAY...THEN STRENGTHEN AS IT MOVES NORTH OF THE REGION OVER THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 630 PM MONDAY...LARGE DIFFERENCES CONTINUE TO EXIST BETWEEN
18Z NAM/18Z GFS/01Z RUC RAW MODELS VERSUS THE TEXT 12Z NAM/18Z
GFS/02Z LAMP MOS GUIDANCE. OUTSIDE OF A COUPLE OF LOCATIONS WHERE
LOCAL EFFECTS HAVE PRODUCED CALM WINDS (KINGSTREE AND CONWAY SC
AIRPORTS) 02Z/9 PM EST TEMPERATURES WERE RUNNING SEVERAL DEGREES
ABOVE MOS GUIDANCE. THIS GIVES ME GREATER CONFIDENCE THAT THE RAW
MODELS ARE A BETTER FORECAST FOR TONIGHT`S LOWS THAN MOS.
THE ROOT CAUSE OF THIS DIFFERENCE MAY BE LARGE GROUND-TO-AIR HEAT
TRANSFER OVERNIGHT AS COLD ADVECTION AND WARM SOIL TEMPERATURES
(RELATIVE TO THE INCOMING AIRMASS ANYWAY) SHOULD KEEP LOW-LEVEL
LAPSE RATES QUITE STEEP. IN PAST YEARS THE FIRST NIGHT OF A COLD
WAVE TENDS TO HAVE STEEP...IF NOT DRY ADIABATIC...LAPSE RATES.
THIS UPDATE MADE NO FURTHER SIGNIFICANT CHANGES TO THE FORECAST
WITH LOWS RANGING FROM 20 INLAND TO 22-24 AT THE BEACHES. THIS
SHOULD BE THE COLDEST NIGHT OF THE WINTER SO FAR...AND THE
COLDEST NIGHT WE`VE SEEN SINCE FEBRUARY 20-21, 2015.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...A MID-LEVEL TROUGH AXIS WILL PUSH OFFSHORE
TUESDAY...TO BE FOLLOWED BY SURFACE HIGH PRESSURE BUILDING INTO THE
CAROLINAS FROM THE NORTHWEST. THE COLD AIRMASS WILL REMAIN
ENTRENCHED OVER THE FORECAST AREA TUESDAY AND DESPITE ABUNDANT
SUNSHINE...HIGHS WILL ONLY TOP OUT WITHIN A COUPLE OF DEGREES EITHER
SIDE OF 40. MINIMUM RH VALUES ARE EXPECTED TO DROP BELOW 25 PERCENT
TUESDAY AFTERNOON AS SINGLE DIGIT DEWPOINTS FILTER IN. RAINFALL THAT
OCCURRED OVER MUCH OF THE CWA ON SUNDAY WILL REDUCE FIRE DANGER
CONCERNS BUT FURTHER COORDINATION WITH FORESTRY OVER FUEL MOISTURE
MAY BE NECESSARY TUESDAY MORNING.
TEMPS WILL PLUMMET DURING THE EARLY EVENING HOURS UNDER CLEAR SKIES
AND WITH WINDS EXPECTED TO DECOUPLE. ALTHOUGH IT APPEARS CIRRUS
CLOUDS WILL SPREAD IN FROM THE WEST LATE TUESDAY NIGHT...THE MOST
RAPID TEMPERATURE FALLS WILL HAVE ALREADY OCCURRED. EXPECT LOWS
AROUND 20 DEGREES TUESDAY NIGHT...WITH THE POTENTIAL FOR LOW
SPOTS TO GET A FEW DEGREES COLDER IF THE CIRRUS HOLDS OFF LONG
ENOUGH.
1000-850 MB THICKNESS FIELDS REFLECT SOME MODERATION OF THE AIRMASS
WEDNESDAY AFTERNOON AND NIGHT AS THE SURFACE HIGH SHIFTS OFF THE
COAST. CONSENSUS GUIDANCE SUGGESTS HIGHS WEDNESDAY RANGING FROM THE
LOW 40S NORTH TO THE UPPER 40S SOUTH...AND LOWS WEDNESDAY NIGHT
RANGING FROM 28-33.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...THURSDAY WILL BE SEASONABLE OR JUST SHY
DEPENDING ON THE SPEED AT WHICH A COOL AIR WEDGE BREAKS DOWN.
NUDGED FORECAST HIGHS DOWN JUST A TAD MAINLY OVER INTERIOR ZONES
SINCE MODELS TEND TO BE TOO FAST IN DOING SO. THERE`S SUFFICIENT
CONFLUENT FLOW ALOFT OVER THE NORTHEAST THAT SHOULD FORTIFY THE
HIGH. A DEEP SOUTHERN BRANCH FEATURE WILL BE CROSSING TEXAS AND
LEAD TO CYCLOGENESIS. THIS LOW WILL MOVE TO ABOUT THE TN/NC BORDER
BY LATE FRIDAY WHILE AN OFFSHORE ENERGY TRANSFER TO AN OFFSHORE
LOW GETS UNDERWAY. WHILE THE MID-ATLANTIC WILL LIKELY BE DEALING
WITH A LARGE MILLER TYPE B NOR`EASTER THE COASTAL PLAIN WILL
REMAIN IN THE WARM SECTOR AND THANKS TO THE GOMEX COULD SEE A
REALLY GOOD SOAKING INCLUDING SOME EMBEDDED TSTMS. FRIDAY NIGHT
THE SYSTEM OCCLUDES OFF THE MID-ATLANTIC COAST AND WE FIND
OURSELVES IN A COLD AIR CHASING MOISTURE SETUP. THERE SEEMS AMPLE
EVIDENCE BETWEEN VARIOUS GUIDANCE THAT INLAND ZONES COULD SEE
WRAPAROUND DYNAMIC RAIN/SNOW SHOWERS BUT NO ACCUMULATION. IN THE
WAKE OF THE NORTHEAST STORM THE WEEKEND WILL BE BRISK AND COOL
LOCALLY BUT THERE IS NO ARCTIC CONNECTION LIKE DURING THE SHORT
TERM. WE MAY BOUNCE BACK TOWARDS CLIMO BY MONDAY AS THE PATTERN
LOOKS NOT ONLY PROGRESSIVE BUT ALSO ONE LOOKING FOR REPEAT
PERFORMANCES AS ANOTHER LOW MAY FORM IN THE GULF JUST AFTER THE
PERIOD...A VERY ACTIVE PATTERN!
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...EXPECT VFR THROUGH THE VALID TAF PERIOD.
NEARLY CLEAR SKIES WILL PREVAIL TONIGHT THROUGH TUESDAY AS HIGH
PRESSURE CONTINUES TO BUILD INTO THE REGION. LIGHT NORTHWEST WINDS
TONIGHT WILL INCREASE TO AOB 12 KTS ON TUESDAY...WITH AFTERNOON
GUSTS UP TO 18 KTS POSSIBLE. AFTER SUNSET...QUIET CONDITIONS
CONTINUE WITH LIGHT NORTHWEST WINDS.
EXTENDED OUTLOOK...EXPECT VFR THROUGH THURSDAY. MODERATE CONFIDENCE
FOR MODERATE TO HEAVY RAIN ON FRIDAY WITH INTERMITTENT IFR
CONDITIONS. CONTINUED UNSETTLED WEATHER ON SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM MONDAY...WINDS HAVE VEERED NORTHERLY AS EXPECTED.
SPEEDS ARE CURRENTLY 5-10 KT AT THE BEACHES BUT GUSTS ARE STILL
REACHING 20-25 KT OFFSHORE AS SHOWN BY DATA FROM THE EDISTO AND
FRYING PAN SHOALS BUOYS. THROUGH MIDNIGHT WINDS SHOULD AVERAGE 15
TO OCCASIONALLY 20 KT AND WILL DECREASE TO 10-15 KT LATE. WITH THE
SHORT OFFSHORE FETCH THIS SHOULD KEEP WAVE HEIGHTS IN THE 2-4 FOOT
RANGE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...THE CENTER OF SURFACE HIGH PRESSURE WILL BE
LOCATED TO THE NORTHWEST OVER THE OHIO RIVER VALLEY EARLY TUESDAY
AND RESULT IN SUSTAINED OFFSHORE WINDS AROUND 15 KNOTS. GUSTS IN THE
20-25 KNOT RANGE ARE LIKELY DURING THE DAY TUESDAY AS ONGOING COLD
AIR ADVECTION OVER THE RELATIVELY WARMER OCEAN WATERS WILL MIX DOWN
THOSE HIGHER WINDS SPEEDS. DO NOT PLAN ON ISSUING A SMALL CRAFT
ADVISORY AT THIS TIME...BUT IF IT BECOMES APPARENT THAT 25 KNOT GUSTS
WILL BE FREQUENT...AN ADVISORY MAY BE ISSUED LATER TONIGHT. DUE TO
THE OFFSHORE FLOW...SEAS TUESDAY WILL RANGE FROM 1 TO 2 FEET NEAR
SHORE TO 3-4 FEET BEYOND 10 NM...HIGHEST IN THE VICINITY OF FRYING
PAN SHOALS WHERE SOME 5 FOOTERS ARE NOT OUT OF THE QUESTION.
THE COLD ADVECTION WILL CONTINUE TUESDAY NIGHT BUT WINDS OFF THE
DECK WILL BE LIGHTER...SO GUSTINESS SHOULD DIMINISH TO LESS THAN 20
KNOTS OVERNIGHT. THE HIGH WILL MOVE OVERHEAD WEDNESDAY AND OFFSHORE
WEDNESDAY NIGHT RESULTING IN WINDS AROUND 10 KNOTS AND SEAS 2 FEET
OR LESS.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM MONDAY...DESPITE A QUIET START MOST OF THE LONG TERM
WILL FEATURE SOME RATHER NASTY CONDITIONS FOR MARINERS. INITIALLY
ON THURSDAY THERE WILL BE A WEAKENING HIGH WEDGED UP THE EAST FACE
OF THE APPALACHIANS. LIGHT OFFSHORE FLOW WILL VEER SLIGHTLY AS THE
HIGH WEAKENS AND THERE MAY BE A LATE DAY PERIOD OF LIGHT AND
VARIABLE CONDITIONS. WARM FRONT LIFTS THROUGH THURSDAY NIGHT AND
WE QUICKLY END UP IN THE FLOW REGIME OF A (PERHAPS RAPIDLY)
STRENGTHENING LOW CROSSING THE GULF STATES. SURFACE GRADIENT WINDS
WILL BE QUITE STRONG AND THE RESULTING WIND AND SEAS WOULD
CERTAINLY LEAD TO ADVISORY LEVELS. HOWEVER THE DYNAMIC NATURE OF
THIS STORM WILL MEAN SOME VERY STRONG LOW LEVEL WINDS JUST ABOVE
THE SURFACE THAT COULD LEAD TO FREQUENT GALE FORCE GUSTS. GFS
PROGS 50KT AT 925MB, FOR EXAMPLE WITH VERTICAL THERMAL PROFILES
THAT MAY ALLOW THOSE TO READILY MIX DOWN. FRIDAY NIGHT BRINGS THE
ABRUPT TURN FROM PREFRONTAL TO POSTFRONTAL/NWRLY FLOW. SOLID
ADVISORY LEVEL WIND AND SEAS CONTINUE THOUGH THE OPPORTUNITY FOR
GALES WANES CONSIDERABLY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CRM
NEAR TERM...TRA
SHORT TERM...CRM
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS PORTLAND OR
901 PM PST SAT JAN 16 2016
.SYNOPSIS...A BRIEF BREAK IN RAIN TONIGHT THEN A FRONT WILL BRING
ANOTHER ROUND OF RAIN AND HIGH ELEVATION SNOW SUNDAY AND SUNDAY
NIGHT. THERE WILL BE ANOTHER BREAK IN RAIN MONDAY MORNING BEFORE A
COUPLE OF LOWS PRODUCE ADDITIONAL RAIN AND CASCADE SNOW MONDAY
AFTERNOON THROUGH TUESDAY NIGHT. THE PROGRESSIVE WEATHER PATTERN OF
RAIN EVERY 24 HOURS OR SO WILL PERSIST THROUGH NEXT WEEKEND.
&&
.SHORT TERM...RAIN HAS GENERALLY MOVED OUT OF THE AREA THIS EVENING
WITH THE EXCEPTION OF A FEW DISSIPATING SHOWERS IN THE SOUTH WASHINGTON
CASCADES. RADAR SHOWS A BAND OF REFLECTIVITY MOVING NORTHEAST ACROSS
THE AREA BUT NO REPORTS OF RAIN ON THE GROUND SO IT IS LIKELY VIRGA.
THE 03Z HRRR AND RAP SHOW2 WHAT LOOKS SOME WARM FRONTAL PRECIP OVER
THE COAST AND COAST RANGE MUCH EARLIER THAN THE REST OF THE
MODELS...BEGINNING AS EARLY AS 11 PM. THEN LONGER LASTING AND
STEADIER PRECIP ARRIVES ON THE COAST BETWEEN ABOUT 4 AM AND 6
AM...MOVING INLAND THROUGH THE MORNING HOURS. WITH NOTHING SHOWING UP
ON IR SATELLITE IMAGERY AT THE MOMENT TO INDICATE RAIN HEADED INTO
THE AREA BEFORE MIDNIGHT...IT IS HARD TO BELIEVE THE HRRR AND RAP
SOLUTION BUT IT SHOULD BE MORE THAN A COINCIDENCE THAT THEY ARE BOTH
SHOWING SIMILAR SCENARIOS. WILL BE INTERESTING TO SEE IF THE 06Z RUN
OF THE NAM AND GFS SHOWS THE PRELIMINARY PRECIP BUT BY THE TIME THEY
COME IN THE PRECIP WILL HAVE EITHER DEVELOPED OR NOT. OVERALL...MOST
AREAS WILL REMAIN DRY FOR MUCH OF THE NIGHT UNTIL THE WIDESPREAD
STEADY RAIN ARRIVES SUNDAY MORNING....FIRST AT THE COAST LIKELY
BEFORE SUNRISE AND THEN SPREADING INLAND THROUGH THE MORNING COMMUTE.
MODEST MOISTURE IS AVAILABLE WITH THIS SYSTEM WITH FORECASTED
TROPICAL PRECIPITABLE WATER VALUES NEAR AN INCH. THIS MOISTURE
COMBINED WITH DECENT LIFT FROM A 120+ KT UPPER JET PROVIDES THE
POTENTIAL FOR DECENT RAINFALL TOTALS. HOWEVER...THE FRONT IS RATHER
QUICK MOVING...WHICH SHOULD HELP LIMIT THE TOTALS AND DETER ANY
HYDROLOGICAL PROBLEMS. OVERALL EXPECT 0.75 TO 1.25 INCHES OF RAIN
OVER THE COAST...COAST RANGE AND CASCADES SUNDAY MORNING THROUGH
SUNDAY AFTERNOON WITH BETWEEN 0.4 AND 0.65 INCH FOR THE INTERIOR
VALLEYS.
A SHORTWAVE UPPER LEVEL TROUGH WILL MOVE OVER THE REGION SUNDAY
EVENING AND BRING THE POTENTIAL FOR THUNDERSTORMS ALONG THE COASTAL
WATERS AND THE IMMEDIATE COAST. THE UPPER TROUGH WILL ALSO BRING
COOLER AIR AND SNOW LEVELS WILL LOWER TO AROUND 4500 FEET SUNDAY
NIGHT. CAN EXPECT AN ADDITIONAL 0.25 TO 0.5 INCH FOR THE CASCADES
SUNDAY EVENING AND SUNDAY NIGHT WITH LESS THAN 0.25 INCH ELSEWHERE.
A FEW SHOWERS WILL LINGER OVER THE HIGHER TERRAIN EARLY MONDAY
MORNING...MAINLY TO THE NORTH. THE REST OF THE MORNING SHOULD BE
FAIRLY DRY BEFORE ANOTHER OCCLUDED FRONT BRINGS ADDITIONAL RAIN
MONDAY AFTERNOON. THIS FRONT WILL MOVE ACROSS THE REGION MONDAY
AFTERNOON AND MONDAY NIGHT. ANOTHER LOW WILL APPROACH FROM THE SW
MONDAY NIGHT...AND BRING ANOTHER FRONTAL SYSTEM TUESDAY AND TUESDAY
NIGHT. THERE MAY NOT BE MUCH OF A BREAK BETWEEN THE TWO FRONTS...AND
CAN GENERALLY EXPECT ANOTHER 0.75 TO 1.25 INCHES OF RAIN FOR THE
COAST RANGE AND CASCADES...WITH 0.4 TO 0.6 INCH FOR THE INTERIOR
VALLEYS MONDAY MORNING THROUGH TUESDAY NIGHT. SNOW LEVELS WILL BE
AROUND 4000 FEET. BOWEN/TJ
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...TUESDAY NIGHT
THROUGH SATURDAY...ACTIVE AND MILD WEATHER PATTERN THROUGH NEXT
WEEKEND. TUESDAY NIGHT WE WILL HAVE A FAST MOVING LOW PRESSURE SYSTEM
MOVING OFF TO THE EAST. THE ECMWF IS A LITTLE SLOWER...KEEPING MORE
RAIN OVER THE AREA LATER...WHILE THE
GFS MOSTLY DRIES OUT EVERYWHERE WEST OF THE CASCADES WEDNESDAY
MORNING. WEDNESDAY MIDDAY THROUGH THE EARLY EVENING HOURS SHOULD BE
MOSTLY DRY AS SHORTWAVE RIDGING BUILDS OVER THE AREA AHEAD OF THE
NEXT SYSTEM BRINGING MORE RAIN WEDNESDAY NIGHT THROUGH THURSDAY.
MODELS HAVE THIS NEXT SYSTEM BRINGING TROPICAL MOISTURE FURTHER
NORTH...LOOKING LIKE A POSSIBLE ATMOSPHERIC RIVER EVENT. THIS MEANS
GREATER POTENTIAL FOR HEAVY RAIN ACROSS OUR AREA. DON`T FEEL
CONFIDENT ABOUT THE LOCATION OF THE HEAVIEST RAIN THIS FAR OUT...BUT
WITH THE MORE SOUTHERN STORM TRACK IN PLACE WOULD THINK A GREATER
POTENTIAL FOR HEAVY RAIN OVER THE SOUTHERN HALF OF OUR AREA. THIS
TYPE OF EVENT WILL BRING TEMPERATURES UP ABOVE NORMAL...AND LIFT
SNOW LEVELS UP ABOVE THE PASSES ON THURSDAY INTO EARLY FRIDAY DURING
THE BULK OF THE PRECIPITATION. WEATHER LOOKS TO REMAIN ACTIVE INTO
THE WEEKEND WITH SNOW LEVELS DROPPING BACK DOWN BELOW THE PASSES
FRIDAY NIGHT...THOUGH DETAILS ARE VERY UNCERTAIN THAT FAR OUT IN THE
FORECAST PERIOD IN THIS TYPE OF PATTERN. -MCCOY
&&
.AVIATION...PRIMARILY VFR THIS EVENING...EXCEPT FOR POCKETS OF
MVFR CIGS ALONG THE COAST AND MOUNTAIN OBSCURATION. EXPECT
VFR TO PREVAIL ALONG THE COAST THROUGH ABOUT 10Z THEN CONDITIONS
FALL TO MVFR OR LOWER BETWEEN 10Z AND 16Z SUN. IMPROVEMENT TO VFR
LATE SUN AFTERNOON INTO THE EVENING. INLAND AREAS SHOULD HOLD ON
TO VFR THROUGH AT LEAST 12Z AND THEN DROP INTO MVFR DURING THE
MORNING. MOUNTAINS BECOME OBSCURED SUN MORNING. OFFSHORE LOW-LEVEL
GRADIENT DEVELOPS THROUGH THE COLUMBIA GORGE TONIGHT AND PERSISTS
INTO THE EARLY AFTERNOON. LLWS POSSIBLE WITH SURFACE EAST WIND AND
S-SW 30-40KT WIND AT FL020.
KPDX AND APPROACHES...GENERALLY VFR THROUGH AT LEAST 12Z SUN.
CONDITIONS LOWER IN THE MORNING WITH RAIN DEVELOPING AROUND
SUNRISE. IMPROVEMENT TO VFR LATE SUN AFTERNOON. E-SE SURFACE WIND
THROUGH EARLY AFTERNOON THEN A SWITCH TO THE S. POTENTIAL LLWS
ALONG ERN APPROACHES TONIGHT THROUGH EARLY SUN AFTERNOON. WEISHAAR
&&
.MARINE...MINIMAL CHANGES TO THE SHORT TERM FORECAST. STILL
LOOKING AT GALES FOR THE WATERS TONIGHT THROUGH SUN MORNING. PEAK
WIND PERIOD FOR THE OUTER WATERS SHOULD BE 08Z-13Z AND 10Z-14Z OR
SO FOR THE INNER WATERS. LATEST NAM RUN SEEMS TO BE A LITTLE
LIGHTER ON WIND SPEEDS COMPARED TO THE PREVIOUS VERSION. NEWEST
NAM HAS 30-35 KT BOUNDARY LAYER WIND SPEEDS FOR THE OUTER WATERS
12Z SUN WITH 975 MB SPEEDS IN THE 35-42 KT RANGE. FAR SW WATERS
MAY SEE A FEW GUSTS UP TO 45 KT. WIND SPEEDS EASE LATE SUN MORNING
THROUGH THE AFTERNOON. THE NEXT FRONTAL SYSTEM MOVES THROUGH THE
WATERS MON. LATEST NAM AND GFS SHOW POSSIBLE LOW-END GALE FORCE
GUSTS DEVELOPING LATE MON MORNING AND CONTINUING THROUGH THE
AFTERNOON.
MAJOR MODEL DIFFERENCES REGARDING THE TUE SYSTEM. THE LATEST NAM
HAS A 988 MB LOW NEAR 46N 125W 00Z WED WHILE THE GFS HAS IT INLAND
OVER THE COLUMBIA BASIN. IF THE NAM VERIFIES...STORM FORCE WIND
NOT OUT OF THE QUESTION. THEN THERE IS THE 12Z ECMWF MODEL WHICH A
990 MB LOW A LITTLE WEST OF BUOY 46027.
SEAS HOVERING AROUND 20 FT THIS EVENING...PRETTY CLOSE TO THE 12
HR ENP GUIDANCE. LONG-PERIOD 19-20 SEC SWELL RESULTING IN A LOT
ENERGY WITH THESE WAVES. WAVE HEIGHTS EASE JUST A BIT LATE TONIGHT
THROUGH SUN MORNING THEN RAMP UP WITH THE NEXT SYSTEM...LIKELY
PEAKING AT 20 TO 22 FT EARLY SUN EVENING. SEAS REMAIN ELEVATED IN
THE MID TEENS THROUGH LATE MONDAY. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH SURF ADVISORY UNTIL MIDNIGHT PST SUNDAY NIGHT FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.
WA...HIGH SURF ADVISORY UNTIL MIDNIGHT PST SUNDAY NIGHT FOR SOUTH
WASHINGTON COAST.
PZ...GALE WARNING UNTIL 9 AM PST SUNDAY FOR WATERS FROM CAPE
SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM-WATERS
FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
PST SUNDAY.
GALE WARNING FROM 3 AM TO 9 AM PST SUNDAY FOR COASTAL WATERS
FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM-
COASTAL WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1035 PM EST MON JAN 18 2016
.SYNOPSIS...
A WESTERLY FLOW OF ARCTIC AIR WILL CAUSE LAKE EFFECT SNOWS ACROSS
NORTHWESTERN PENNSYLVANIA TONIGHT AND EARLY TUESDAY. HIGH
PRESSURE WILL THEN PROVIDE MAINLY DRY WEATHER THROUGH THURSDAY. A
SURFACE LOW WILL DEVELOP OVER THE DEEP SOUTH ON FRIDAY AND DEEPEN
AS IT MOVES NORTHEAST TO THE MID-ATLANTIC COAST. THIS STORM HAS
THE POTENTIAL TO BRING A WIDESPREAD SIGNIFICANT SNOWFALL TO THE
MID-ATLANTIC REGION.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LAKE EFFECT SNOW ADVISORY CANCELLED FOR ELK CAMERON AND POTTER.
LAKE EFFECT SNOW WARNINGS CONTINUE FOR WARREN AND MCKEAN...AS WELL
AS WIND CHILL ADVISORIES FOR CAMBRIA AND SOMERSET.
UPSLOPE FLOW INTO THE WEST CENTRAL AND NORTHWEST MOUNTAINS IS
MAINTAINING NEARLY CONSTANT BUT LIGHT 1-2SM -SN IN THE WRN AND
NORTHWEST MTNS. SNOWBANDS HAVE SHIFTED SOUTH THIS EVENING BACK
OVER THE LE WARNING AREA. LATEST HRRR CONTINUES TO INDICATE THAT
THESE WILL SAG SOUTHWARD IN THE BACKING FLOW OVERNIGHT. WILL ADD
TO EARLIER TOTALS OVERNIGHT AS A RESULT...AND THUS LAKE EFFECT
WARNINGS CONTINUE.
WIND CHILL ADVY STILL SOLID IN THE ADVY AREA AND TEMPS GETTING
COLDER TONIGHT. MINS WILL GET INTO THE SINGLE DIGITS FOR MUCH OF
THE AREA...WITH DOUBLE DIGITS HERE AND THERE - MAINLY IN THE
VALLEYS OF THE EAST. SOME SOTS IN THE LAURELS LIKE MEYERSDALE
COULD GET BELOW 0F AIR TEMP.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
HIGHEST MOISTURE DISSIPATES IN PLACE ON TUESDAY AFTER THE PASSAGE
OF A STRONG VORT MAX AROUND SUNRISE. BUT SOME UPSLOPE/FLURRIES
MAY LINGER IN THE LAURELS FOR THE MORNING AND SHSN IN THE NW FOR
MUCH OF THE DAY DUE TO FAVORABLE FETCH AND TEMPS. HOWEVER...THE
SIG ACCUMS SHOULD BE TAPERING OFF IN THE MORNING. SUBSIDENCE
SHOULD HELP TO SQUASH THE VERTICAL MOTION/INSTABILITY. WARNING
ONLY GOES UNTIL 12Z...EXP TIMING THERE S/B FINE EVEN IF SOME LIGHT
ACCUMS LINGER. THE WORST OF IT WILL BE OVER BY THEN. WILL LINGER
CLOUDS ACROSS THE N FOR MOST OF THE DAY. MAXES SHOULD BE 2-7F
MILDER THAN TODAY WITH MORE SUN AND SLIGHTLY HIGHER 8H TEMPS AND
MIXING. WIND CHILLS WILL INCREASE SLIGHTLY AS THE TEMPS DO. THIS
SHOULD ALLOW THE WC ADVY TO EXPIRE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
POTENTIAL WINTER STORM COULD BRING IMPACTS TO CENTRAL PA FRI INTO
SAT NIGHT.
1035MB SURFACE HIGH STRETCHING FROM THE UPPER MIDWEST THROUGH THE
OHIO VALLEY WILL WEAKEN SOMEWHAT AS IT SPREADS INTO THE AREA LATE
TUESDAY...AHEAD OF A WEAKENING AND MOISTURE-CHALLENGED ALBERTA
CLIPPER WHICH WILL BRING A CHANCE OF LIGHT SNOW SHOWERS TO MAINLY
WESTERN SECTIONS WEDNESDAY NIGHT...WITH ONLY MINOR ACCUMULATIONS
EXPECTED.
HIGH RE-ESTABLISHES OVER CENTRAL PA THU...THOUGH THIS TIME ONLY
IN THE 1024-1028MB RANGE...AND RETREAT NORTHWARD ON FRI. AT THE
SAME TIME...LOW PRESSURE EXPECTED TO DEEPEN OVER SOUTHERN
APPALACHIANS AND MOVE ACROSS MID-ATLANTIC STATES FRI NIGHT AND
SAT. THOUGH POTENTIAL WINTER STORM REMAINS SEVERAL DAYS OUT...AND
SHORTWAVE ENERGY AT THIS TIME REMAINS WELL OUT OVER THE PACIFIC
OCEAN...MOST EXTENDED MODEL GUIDANCE APPEARS TO BE LATCHING ON TO
AND TRACKING IT FAIRLY WELL. THE WAVE SHOULD ARRIVE ON THE PACIFIC
COAST TUE NIGHT AND DROP INTO THE CENTRAL PLAINS ON THU. COMBO OF
THE EARLIER-IN-THE-WEEK CLIPPER AND THIS WAVE CARVE OUT A
SHARPENING TROUGH FOR THE EAST COAST LATE WEEK AS RIDGE FORMS OVER
THE ROCKIES. LATEST 12Z GEFS AND OPERATIONAL GFS REVEAL NO BIG
CHANGES WITH 12Z ECMWF HUGGING THE MID ATLANTIC COAST A BIT
LONGER...THOUGH THIS FAR OUT THE MODELS STILL OVERALL APPEAR IN
FAIRLY GOOD BASIC AGREEMENT WITH TIMING AND TRACK OF LOW
PRESSURE AS IT STRENGTHENS.
BASED ON MODEL CONSENSUS THIS FAR OUT...THERE CONTINUES TO BE
MEDIUM CONFIDENCE FOR A SIGNIFICANT WINTER STORM OVER THE MID
ATLANTIC AND NORTHEAST FRIDAY AFTERNOON THROUGH SATURDAY...
WITH BIGGEST POTENTIAL IMPACTS TO CWA BEING ROUGHLY THE SOUTHEAST
HALF. CONSENSUS PTYPE IS SNOW...WITH PLENTY OF COLD AIR IN
PLACE. KEEP IN MIND THAT OBVIOUSLY IT/S STILL FAR TOO EARLY TO
SAY FOR CERTAIN 4-5 DAYS OUT...ESPECIALLY WHEN THE WAVE DRIVING
THIS ISN/T EVEN TO THE WEST COAST YET. THERE ARE STILL A LOT OF
VARIABLES IN PLAY THAT COULD IMPACT THE EVOLUTION OF THIS SYSTEM.
LOOKING PAST THE STORM AFTER IT MOVES AWAY SAT NIGHT AND
SUNDAY...PACIFIC HIGH PRESSURE LOOKS TO BUILD INTO THE REGION
PROVIDING GENERALLY FAIR AND MILDER CONDS THAN WE WILL SEE FOR
MOST OF THIS WEEK. A CLIPPER MAY BRING ANOTHER ROUND OF LIGHT SNOW
TO THE NORTH AND WEST EARLY NEXT WEEK.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SOUTHERN EDGE OF LAKE EFFECT SNOW BAND HAS LIFTED JUST NORTH OF
KBFD THIS EVENING...SO EXPECT MAINLY MVFR CONDS THERE THRU
MIDNIGHT. NEAR TERM MDL DATA CONTINUES TO INDICATE LAKE EFFECT
PLUME WILL SHIFT SOUTH AFTER MIDNIGHT...FAVORING PREDOMINANTLY
IFR CONDS BTWN 05Z-12Z. ELSEWHERE...UPSLOPE FLOW PRODUCING LGT
SNOW WITH VSBYS BTWN 1-2SM LATE THIS EVENING. NEAR TERM MDL DATA
AND LINEAR EXTRAPOLATION OF SATL IMAGERY SUGGEST DRIER AIR SHOULD
ARRIVE BY ARND 06Z...LIKELY RESULTING IN IMPROVING CONDS AT KJST LATE
TONIGHT. FOR THE REST OF CENTRAL PA...DRYING EFFECT OF DOWNSLOPING
WESTERLY FLOW SHOULD YIELD VFR FLYING OVERNIGHT.
HIGH PRESSURE BUILDING IN FROM THE MIDWEST WILL CAUSE LAKE EFFECT
SNOW TO TAPER OFF ACROSS THE NW MTNS TUESDAY. HOWEVER...RESIDUAL
LOW LVL MOISTURE ASCENDING THE ALLEGHENIES SHOULD CAUSE MVFR
STRATOCU TO PERSIST INTO TUE EVENING AT KBFD AND KJST. AFTER A BIT
OF A LULL IN THE WINDS OVERNIGHT...EXPECT GUSTY WINDS TO REDEVELOP ACROSS
THE ENTIRE AREA FROM LATE AM THRU EARLY EVENING TUES...AS DIURNAL
HEATING/DEEPENING BLYR DEPTH ALLOW STRONGER WINDS TO MIX TO THE
SFC. BUFKIT SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS TUE AFTN.
OUTLOOK...
WED...A BRIEF EVENING -SHSN/VIS REDUCTION POSSIBLE KJST/KBFD.
THU...NO SIG WX EXPECTED.
FRI...SNOW POSSIBLE...ESP SOUTH.
SAT...SNOW/WIND POSSIBLE...ESP SOUTH/EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR PAZ004-005.
WIND CHILL ADVISORY UNTIL 10 AM EST TUESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1021 PM EST MON JAN 18 2016
.SYNOPSIS...
A WESTERLY FLOW OF ARCTIC AIR WILL CAUSE LAKE EFFECT SNOWS ACROSS
NORTHWESTERN PENNSYLVANIA TONIGHT AND EARLY TUESDAY. HIGH
PRESSURE WILL THEN PROVIDE MAINLY DRY WEATHER THROUGH THURSDAY. A
SURFACE LOW WILL DEVELOP OVER THE DEEP SOUTH ON FRIDAY AND DEEPEN
AS IT MOVES NORTHEAST TO THE MID-ATLANTIC COAST. THIS STORM HAS
THE POTENTIAL TO BRING A WIDESPREAD SIGNIFICANT SNOWFALL TO THE
MID-ATLANTIC REGION.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LAKE EFFECT SNOW ADVISORY CANCELLED FOR ELK CAMERON AND POTTER.
LAKE EFFECT SNOW WARNINGS CONTINUE FOR WARREN AND MCKEAN...AS WELL
AS WIND CHILL ADVISORIES FOR CAMBRIA AND SOMERSET.
UPSLOPE FLOW INTO THE WEST CENTRAL AND NORTHWEST MOUNTAINS IS
MAINTAINING NEARLY CONSTANT BUT LIGHT 1-2SM -SN IN THE WRN AND
NORTHWEST MTNS. SNOWBANDS HAVE SHIFTED SOUTH THIS EVENING BACK
OVER THE LE WARNING AREA. LATEST HRRR CONTINUES TO INDICATE THAT
THESE WILL SAG SOUTHWARD IN THE BACKING FLOW OVERNIGHT. WILL ADD
TO EARLIER TOTALS OVERNIGHT AS A RESULT...AND THUS LAKE EFFECT
WARNINGS CONTINUE.
WIND CHILL ADVY STILL SOLID IN THE ADVY AREA AND TEMPS GETTING
COLDER TONIGHT. MINS WILL GET INTO THE SINGLE DIGITS FOR MUCH OF
THE AREA...WITH DOUBLE DIGITS HERE AND THERE - MAINLY IN THE
VALLEYS OF THE EAST. SOME SOTS IN THE LAURELS LIKE MEYERSDALE
COULD GET BELOW 0F AIR TEMP.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
HIGHEST MOISTURE DISSIPATES IN PLACE ON TUESDAY AFTER THE PASSAGE
OF A STRONG VORT MAX AROUND SUNRISE. BUT SOME UPSLOPE/FLURRIES
MAY LINGER IN THE LAURELS FOR THE MORNING AND SHSN IN THE NW FOR
MUCH OF THE DAY DUE TO FAVORABLE FETCH AND TEMPS. HOWEVER...THE
SIG ACCUMS SHOULD BE TAPERING OFF IN THE MORNING. SUBSIDENCE
SHOULD HELP TO SQUASH THE VERTICAL MOTION/INSTABILITY. WARNING
ONLY GOES UNTIL 12Z...EXP TIMING THERE S/B FINE EVEN IF SOME LIGHT
ACCUMS LINGER. THE WORST OF IT WILL BE OVER BY THEN. WILL LINGER
CLOUDS ACROSS THE N FOR MOST OF THE DAY. MAXES SHOULD BE 2-7F
MILDER THAN TODAY WITH MORE SUN AND SLIGHTLY HIGHER 8H TEMPS AND
MIXING. WIND CHILLS WILL INCREASE SLIGHTLY AS THE TEMPS DO. THIS
SHOULD ALLOW THE WC ADVY TO EXPIRE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
POTENTIAL WINTER STORM COULD BRING IMPACTS TO CENTRAL PA FRI INTO
SAT NIGHT.
1035MB SURFACE HIGH STRETCHING FROM THE UPPER MIDWEST THROUGH THE
OHIO VALLEY WILL WEAKEN SOMEWHAT AS IT SPREADS INTO THE AREA LATE
TUESDAY...AHEAD OF A WEAKENING AND MOISTURE-CHALLENGED ALBERTA
CLIPPER WHICH WILL BRING A CHANCE OF LIGHT SNOW SHOWERS TO MAINLY
WESTERN SECTIONS WEDNESDAY NIGHT...WITH ONLY MINOR ACCUMULATIONS
EXPECTED.
HIGH RE-ESTABLISHES OVER CENTRAL PA THU...THOUGH THIS TIME ONLY
IN THE 1024-1028MB RANGE...AND RETREAT NORTHWARD ON FRI. AT THE
SAME TIME...LOW PRESSURE EXPECTED TO DEEPEN OVER SOUTHERN
APPALACHIANS AND MOVE ACROSS MID-ATLANTIC STATES FRI NIGHT AND
SAT. THOUGH POTENTIAL WINTER STORM REMAINS SEVERAL DAYS OUT...AND
SHORTWAVE ENERGY AT THIS TIME REMAINS WELL OUT OVER THE PACIFIC
OCEAN...MOST EXTENDED MODEL GUIDANCE APPEARS TO BE LATCHING ON TO
AND TRACKING IT FAIRLY WELL. THE WAVE SHOULD ARRIVE ON THE PACIFIC
COAST TUE NIGHT AND DROP INTO THE CENTRAL PLAINS ON THU. COMBO OF
THE EARLIER-IN-THE-WEEK CLIPPER AND THIS WAVE CARVE OUT A
SHARPENING TROUGH FOR THE EAST COAST LATE WEEK AS RIDGE FORMS OVER
THE ROCKIES. LATEST 12Z GEFS AND OPERATIONAL GFS REVEAL NO BIG
CHANGES WITH 12Z ECMWF HUGGING THE MID ATLANTIC COAST A BIT
LONGER...THOUGH THIS FAR OUT THE MODELS STILL OVERALL APPEAR IN
FAIRLY GOOD BASIC AGREEMENT WITH TIMING AND TRACK OF LOW
PRESSURE AS IT STRENGTHENS.
BASED ON MODEL CONSENSUS THIS FAR OUT...THERE CONTINUES TO BE
MEDIUM CONFIDENCE FOR A SIGNIFICANT WINTER STORM OVER THE MID
ATLANTIC AND NORTHEAST FRIDAY AFTERNOON THROUGH SATURDAY...
WITH BIGGEST POTENTIAL IMPACTS TO CWA BEING ROUGHLY THE SOUTHEAST
HALF. CONSENSUS PTYPE IS SNOW...WITH PLENTY OF COLD AIR IN
PLACE. KEEP IN MIND THAT OBVIOUSLY IT/S STILL FAR TOO EARLY TO
SAY FOR CERTAIN 4-5 DAYS OUT...ESPECIALLY WHEN THE WAVE DRIVING
THIS ISN/T EVEN TO THE WEST COAST YET. THERE ARE STILL A LOT OF
VARIABLES IN PLAY THAT COULD IMPACT THE EVOLUTION OF THIS SYSTEM.
LOOKING PAST THE STORM AFTER IT MOVES AWAY SAT NIGHT AND
SUNDAY...PACIFIC HIGH PRESSURE LOOKS TO BUILD INTO THE REGION
PROVIDING GENERALLY FAIR AND MILDER CONDS THAN WE WILL SEE FOR
MOST OF THIS WEEK. A CLIPPER MAY BRING ANOTHER ROUND OF LIGHT SNOW
TO THE NORTH AND WEST EARLY NEXT WEEK.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SOUTHERN EDGE OF LAKE EFFECT SNOW BAND HAS LIFTED JUST NORTH OF
KBFD EARLY THIS EVENING...SO EXPECT MAINLY MVFR CONDS THERE EARLY
THIS EVENING. NEAR TERM MDL DATA CONTINUES TO INDICATE LAKE
EFFECT PLUME WILL SHIFT SOUTH LATER TONIGHT...FAVORING PREDOMINANTLY
IFR CONDS BTWN 04Z-12Z. ELSEWHERE...UPSLOPE FLOW SHOULD YIELD
PREDOMINANTLY MVFR CIGS AT KJST OVERNIGHT WITH A FEW FLURRIES. FOR
THE REST OF CENTRAL PA...DRYING EFFECT OF DOWNSLOPING WESTERLY
FLOW SHOULD YIELD VFR FLYING OVERNIGHT.
HIGH PRESSURE BUILDING IN FROM THE MIDWEST WILL CAUSE LAKE EFFECT
SNOW TO TAPER OFF ACROSS THE NW MTNS TUESDAY. HOWEVER...RESIDUAL
LOW LVL MOISTURE ASCENDING THE ALLEGHENIES SHOULD CAUSE MVFR
STRATOCU TO PERSIST INTO TUE EVENING AT KBFD AND KJST.
OUTLOOK...
WED...A BRIEF EVENING -SHSN/VIS REDUCTION POSSIBLE KJST/KBFD.
THU...NO SIG WX EXPECTED.
FRI...SNOW POSSIBLE...ESP SOUTH.
SAT...SNOW/WIND POSSIBLE...ESP SOUTH/EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR PAZ004-005.
WIND CHILL ADVISORY UNTIL 10 AM EST TUESDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DEVOIR
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
855 PM CST MON JAN 18 2016
.UPDATE...
ISSUED AT 854 PM CST MON JAN 18 2016
THE 00Z NAM HAS BEGUN TO COME IN AND IT IS DIGGING THE UPPER WAVE
CURRENTLY OVER MONTANA FARTHER SOUTH AS IT MOVES INTO THE EASTERN
PLAINS. THIS PUTS THE STRONGEST FORCING FOR ASCENT INTO EASTERN
NEBRASKA MORE QUICKLY. WITH ONLY WEAK LIFT OVER MUCH OF SOUTHWEST
MINNESOTA AND EAST CENTRAL SOUTH DAKOTA...IT IS GOING TO TAKE
LONGER TO OVERCOME THE LOW LEVEL DRY AIR. BOTH THE OPERATIONAL AND
EXPERIMENTAL HRRR AS WELL AS THE RAP NOW HAVE SNOW REACHING SIOUX
CITY BETWEEN 6 AND 8 AM AND SIOUX FALLS BETWEEN 8 AM AND 11 AM.
GIVEN PROGRESSION OF UPPER WAVE...THAT SEEMS REASONABLE AND HAVE
SLOWED SNOW PROGRESSION TO THE EAST. THIS MEANS A LITTLE LESS SNOW
FOR I-29 CORRIDOR NORTH OF BERESFORD WITH SNOWFALL NOW EXPECTED TO
BE CLOSER TO AN INCH THAN TWO INCHES.
UPDATED GRIDS AVAILABLE SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 313 PM CST MON JAN 18 2016
STRATUS SHIELD ACROSS THE NORTHEAST HALF OF THE CWA WAS SLOWER TO
CLEAR/THIN TODAY THAN EXPECTED...BUT APPEARS THAT IT IS ON ITS WAY
BASED ON SCATTERING REPORTED IN SURFACE OBSERVATIONS OVER THE PAST
HOUR OR TWO. STILL ON THE CLOUDIER SIDE THIS AFTERNOON THOUGH...WITH
THICKER HIGH CLOUDS SPILLING INTO THE REGION IN ADVANCE OF SYSTEM
SET TO AFFECT THE AREA TONIGHT/TUESDAY.
THIS SYSTEM NOW MOVING OUT OF THE NORTHERN ROCKIES AND IS SLATED TO
SLIDE ACROSS THE PLAINS AS TONIGHT THROUGH TUESDAY EVENING. LEADING
MID LEVEL WARM FRONT RESPONSIBLE FOR THE THICKER CLOUDS WILL HAVE
LITTLE IMPACT ON SNOW DEVELOPMENT. AS SOUTHERN PORTION OF THE WAVE
DIGS MORE STRONGLY INTO THE SOUTHERN PLAINS...MODELS CONSISTENT IN
SHOWING AN INCREASE IN MID-LEVEL FRONTOGENESIS JUST SOUTH OF OUR
FORECAST AREA BY 12Z TUESDAY...AND THINK THIS WILL BE THE PRIMARY
FOCUS FOR HEAVIER SNOWFALL POTENTIAL AS THAT WAVE SWINGS THROUGH THE
CENTRAL PLAINS. STILL EXPECTING BROAD SWATH OF SNOW EXTENDING NORTH
THROUGH OUR AREA AS WEAKER/NORTHERN PORTION OF THE WAVE MOVES ACROSS
THE DAKOTAS INTO MINNESOTA. HOWEVER WITH FRONTAL FOCUS TO OUR SOUTH
AND SOUNDINGS INDICATING DEEP DRY LAYER WHICH WILL DELAY ONSET OF
ACCUMULATING SNOW A BIT...LOOKS LIKE SNOWFALL AMOUNTS IN OUR AREA
WILL BE A LITTLE LIGHTER THAN PREVIOUSLY FORECAST. STILL GOING FOR
AMOUNTS WITHIN THE 1-3 INCH RANGE FOR CWA...LIGHTEST IN AREAS NORTH
OF I-90 AND ESPECIALLY IN SOUTHWEST MN WHERE DRY LAYER PERSISTS THE
LONGEST.
TEMPERATURES TONIGHT ARE A LITTLE TRICKY AS MANY AREAS WARMED INTO
THE HIGHER END SINGLE DIGITS TO AROUND 10F...AND MANY MODELS DO NOT
HAVE A GREAT HANDLE ON THIS. WILL STILL SEE A DROPOFF IN TEMPS THIS
EVENING BEFORE LOW-MID CLOUDS BEGIN TO THICKEN/PUSH EAST...BUT MAIN
QUESTION IS HOW MUCH. HEDGES TOWARD WARMER END OF AVAILABLE GUIDANCE
NUMBERS...WHICH STILL DROPS FAR EASTERN CWA BACK BELOW ZERO DURING
THE EVENING BEFORE REBOUNDING TO NEAR/ABOVE ZERO BY DAYBREAK. AREAS
FARTHER WEST WILL LIKEWISE SEE EVENING LOWS...FOLLOWED BY STEADY TO
RISING TEMPERATURES LATE TONIGHT. SHOULD CONTINUE TO SEE A SLOW BUT
STEADY CLIMB INTO THE TEENS-LOWER 20S FOR HIGHS TUESDAY...WHICH MAY
SEEM LIKE A HEAT WAVE AFTER THE FRIGID WEEKEND WE JUST HAD.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 313 PM CST MON JAN 18 2016
LINGERING LIGHT SNOW WILL EXIT THE AREA TO THE EAST QUICKLY TUESDAY
EVENING AND AM LIMITING MENTION TO ONLY THE FIRST THREE HOURS OF
TUESDAY NIGHT. IT IS POSSIBLE THERE COULD BE FLURRIES A BIT LONGER
WITH LINGERING STRATUS...BUT ON THE OTHER HAND CAN SEE THE SNOW
ENDING BY 6PM...WHICH OF COURSE IS REFLECTED IN ONLY CHANCE POPS FAR
EAST FOR THAT EARLY EVENING. THE LINGERING STRATUS SHOULD CLEAR OUT
EVENTUALLY TO THE EAST AND NORTHEAST BUT HAVE GONE SLOWLY AS THERE
IS UNCERTAINTY IN STRATUS CLEARING OUT AT NIGHT IN A SOUTHERLY FLOW.
ADD THAT TO THE LIKELIHOOD OF IT REDEVELOPING BY WEDNESDAY NIGHT AS
A WEAK INVERTED TROUGH MOVES TOWARD THE AREA. PARTLY TO MOSTLY
CLOUDY COULD BE TOO BRIGHT FOR A WEDNESDAY FORECAST...BUT WILL GO
WITH THAT FOR NOW.
TUESDAY NIGHT AND WEDNESDAY SHOULD BE A BIT WARMER WITH HIGHS
WEDNESDAY IN THE 20S TO LOWER 30S...STRATUS OR NOT.
ALONG WITH POSSIBLE STRATUS REDEVELOPMENT WEDNESDAY NIGHT...A WEAK
NORTHERN BRANCH SHORT WAVE COULD BRING A LITTLE LIGHT SNOW SOUTH...
MAINLY TO THE MISSOURI RIVER AREA. THIS WAVE IS NOT ONLY WEAK BUT
WEAKENING FURTHER AS A STRONGER WAVE DIVES WELL SOUTH OF THE AREA TO
DEVELOP A SYSTEM THAT SHOULD KEEP PEOPLE IN THE EAST BUSY FOR A FEW
DAYS. THERE COULD BE A LITTLE LIGHT SNOW OR FLURRIES LINGER THURSDAY
IN THE CONTINUING LOW LEVEL MOISTURE AND CLOUD COVER BUT SUPPORT IS
HARD TO FIND AND WILL LEAVE IT MOSTLY CLOUDY WITHOUT PRECIPITATION
FOR NOW.
A FEW DEGREES OF COOLING IS EXPECTED THURSDAY BEHIND THE WEAK
TROUGH...BUT CERTAINLY NO RETURN TO THE ARCTIC COLD OF THE WEEKEND.
FRIDAY THROUGH SUNDAY SHOULD BRING MILDER TEMPERATURES AS UPPER
RIDGING ARRIVES IN THE CENTRAL PLAINS THEN IS FLATTENED A LITTLE BY
ANOTHER WEAK SHORT WAVE. THIS WEAK SHORT WAVE COULD BRING A LITTLE
LIGHT SNOW FOR SUNDAY...BUT AGAIN NOTHING TO GET VERY EXCITED ABOUT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 536 PM CST MON JAN 18 2016
AVIATION FORECAST CONCERN IS ASSOCIATED WITH LIGHT SNOW LATER
TONIGHT AND TUESDAY. CLOUDS EXPECTED TO INCREASE THROUGH THE
NIGHT. UNTIL SNOW BEGINS...CIGS EXPECTED TO REMAIN VFR...ALTHOUGH
CIGS WILL LOWER TO 4000 OR 5000 FEET AFTER MIDNIGHT. THE
EXCEPTION WILL BE IN SOUTH CENTRAL SD WHERE THERE MAY BE A PERIOD
OF MVFR CEILINGS THIS EVENING. ONCE SNOW BEGINS...EXPECT CIGS TO
FALL TO AROUND 1000 FT AT KFSD AND KSUX WITH VSBYS OF 1 TO 2 SM.
WOULD NOT BE SURPRISED TO SEE VSBYS BELOW 1 SM FOR BRIEF PERIODS
AT KSUX BUT WITH UNCERTAINTY WITH TIMING WILL NOT INCLUDE IN
FORECAST. SNOW IS EXPECTED TO MOVE EAST OF THE AREA DURING THE
AFTERNOON WITH VSBYS RAPIDLY IMPROVING ABOVE 6 SM. HOWEVER...LOW
CLOUDS WITH CIGS FROM 1000 TO 3000 FT EXPECTED THROUGH 00Z
WEDNESDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...SCHUMACHER
SHORT TERM...JH
LONG TERM...
AVIATION...SCHUMACHER
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1221 PM CST SUN JAN 17 2016
.AVIATION...
/18Z TAFS/
CONCERNS...POTENTIAL FOR MVFR CIGS BEHIND A FRONT THAT ARRIVES
TONIGHT.
LIGHT SOUTH TO SOUTHEAST WINDS WILL PREVAIL THIS AFTERNOON AND
THEN BECOME MORE EASTERLY THIS EVENING AROUND OR JUST AFTER
SUNSET. A FRONT WILL PASS THROUGH OVERNIGHT RESULTING IN NORTH
WINDS LESS THAN 10 KTS. THE FRONT IS EXPECTED TO MOVE ACROSS THE
METROPLEX AROUND 05Z AND KACT AROUND 08Z. NORTH WINDS WILL
CONTINUE TO PREVAIL MONDAY MORNING BUT THE WINDS WILL SHIFT AROUND
TO THE EAST AND SOUTHEAST MONDAY AFTERNOON.
MVFR CIGS CURRENTLY BEHIND THE FRONT IN OKLAHOMA WILL CONTINUE
SLIDING SOUTH TODAY AND TONIGHT. HOWEVER...DO NOT ANTICIPATE THESE
CLOUDS TO MOVE ACROSS THE METROPLEX AIRPORTS AS A BKN DECK BECAUSE
THE LOW LEVEL WINDS ABOVE THE SURFACE ARE EXPECTED TO SHIFT MORE
EAST AND NORTHEASTERLY OVERNIGHT. THIS WILL TEND TO PUSH THE MVFR
CIGS WEST OF THE AIRPORTS. IT IS POSSIBLE THERE MAY BRIEFLY BE
BKN010-015 CONDITIONS AT A FEW OF THE AIRPORTS OVERNIGHT OR MONDAY
MORNING AND WILL CONTINUE TO MONITOR THE TRACKS AND TRENDS. BUT
FOR NOW...WILL INCLUDE A SCT010-015 AT ALL THE TAF SITES BEHIND
THE FRONT.
JLDUNN
&&
.PREV DISCUSSION... /ISSUED 301 AM CST SUN JAN 17 2016/
COLD MORNING IN PROGRESS ACROSS NORTH TEXAS AS A SURFACE HIGH
PRESSURE CENTER MOVES ACROSS THE REGION. WINDS HAVE GONE CALM IN
MANY LOCATIONS AND SURFACE MOISTURE LINGERS. THIS HAS RESULTED IN
AREAS OF SHALLOW FOG IN SOME LOCATIONS. IN OTHERS...WHERE T/TD
SPREADS ARE A LITTLE HIGHER...THICK FROST HAS DEVELOPED. THE FOG
SHOULD BE PATCHY AND SHALLOW AT BEST AND DOES NOT REALLY APPEAR
THAT IT WILL DEPOSIT ICE ON ANY AREA ROADS. AFTER A COLD START...
TEMPERATURES SHOULD REBOUND NICELY INTO THE LOW TO MID 50S BY THIS
AFTERNOON.
THE WARMUP WILL BE BRIEF AS ANOTHER COLD FRONT IS EXPECTED TO MOVE
THROUGH NORTH TEXAS TONIGHT INTO MONDAY MORNING. A LARGE UPPER LOW
WILL BE MOVING THROUGH THE GREAT LAKES REGION DURING THIS TIME AND
WILL ALLOW A 1030MB SURFACE HIGH TO BUILD SOUTHWARD THROUGH THE
PLAINS. TEMPERATURES ARE VERY COLD ACROSS THE UPPER PLAINS WITH
READINGS IN THE -10 TO -20F RANGE ACROSS PARTS OF THE DAKOTAS AND
MINNESOTA. WHILE THE BRUNT OF THE COLDEST AIR WILL STAY WELL TO
OUR NORTHEAST...THE PATTERN IS FAVORABLE TO ALLOW SHALLOW VERY
COLD AIR TO SPILL SOUTHWARD THROUGH THE PLAINS TODAY. AS IS
TYPICAL WITH VERY SHALLOW COLD AIR...THE MODELS ARE USUALLY TOO
WARM WITH TEMPERATURES DUE TO THEIR LACK OF LOW LEVEL RESOLUTION.
THE LATEST HIGH RESOLUTION RAP GUIDANCE DOES GIVE A SMALL HINT
THAT THE AIR MAY BE COLDER ON MONDAY ACROSS NORTH TEXAS THAN
CURRENTLY INDICATED BY THE GFS/NAM/ECMWF. THE LATEST RUN HAS
TEMPERATURES ACROSS PARTS OF CENTRAL OKLAHOMA IN THE LOW 20S ON
SUNDAY EVENING. THIS IS ABOUT 10 DEGREES COLDER THAN THE CURRENT
MOS GUIDANCE. WITH THAT IN MIND...WILL UNDERCUT THE MOS HIGHS FOR
MONDAY...PARTICULARLY NORTH OF I-20. WHILE COLD AIR WILL SPILL
INTO NORTH TEXAS...THE TRAJECTORY OF THE SURFACE HIGH AND THE
PROGRESSIVE NATURE OF THE UPPER PATTERN WILL ENSURE THAT IT WILL
BE SHORT LIVED ACROSS THE REGION. MOSTLY SUNNY SKIES AND A RETURN
TO SOUTHERLY FLOW LATE IN THE DAY ON MONDAY WILL LIKELY MIX SOME
OF THE COLDER AIR BEFORE THE SUN SETS. TEMPERATURES ARE LIKELY TO
BE IN THE LOW/MID 40S ACROSS THE NORTHERN HALF OF THE CWA WITH
UPPER 40S AND LOWER 50S SOUTH OF I-20.
THERE WILL BE SEVERAL SHORTWAVE TROUGHS THAT MOVE THROUGH THE
PLAINS THROUGH NEXT WEEK AND TIMING EACH ONE IS PROVING TO BE
RATHER DIFFICULT. THERE IS STILL QUITE A BIT OF SPREAD IN MODEL
GUIDANCE THROUGH THE END OF THE WEEK. IT DOES APPEAR THAT LOW
LEVEL FLOW WILL BECOME MORE SOUTH/SOUTHWEST ON TUESDAY WHICH WILL
ALLOW FOR A QUICK WARMUP IN TEMPERATURES BACK INTO THE 60S. A WEAK
COLD FRONT WILL MOVE THROUGH ON WEDNESDAY WITH ANOTHER COOL DOWN
BACK TOWARD SEASONAL NORMS. THERE IS A SMALL CHANCE FOR SHOWERS
ALONG THIS FRONT...MAINLY IN OUR SOUTH/SOUTHEAST COUNTIES ALTHOUGH
MOISTURE IS SOMEWHAT LIMITED. SLIGHTLY BETTER RAIN CHANCES APPEAR
TO ARRIVE LATE WEDNESDAY INTO EARLY THURSDAY AS A STRONG SHORTWAVE
MOVES THROUGH THE SOUTHERN PLAINS. THIS RESULTS IN ANOTHER SURFACE
LOW TRACKING ACROSS NORTH TEXAS WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS EXPECTED TO DEVELOP ON THE EAST SIDE OF THE
LOW. A QUICK LOOK AT THE 00Z ENSEMBLE GUIDANCE INDICATES THIS
SHORTWAVE AND ASSOCIATED SURFACE FEATURES IN MOST OF THE ENSEMBLE
MEMBERS...HOWEVER THE TRACK IS QUITE VARIED WITH ABOUT HALF OF
THE GUIDANCE INDICATING RAIN/STORMS ACROSS OUR AREA...AND THE
OTHER HALF FARTHER EAST INTO THE ARKLATEX. THIS RESULTS IN A LOWER
OVERALL CONFIDENCE IN RAIN MIDWEEK BUT WE WILL MAINTAIN 20/30 POPS
LATE WEDNESDAY INTO THURSDAY WITH BEST CHANCES EAST OF INTERSTATE
35.
TEMPERATURES WILL GENERALLY REMAIN WITHIN 5 DEGREES OR SO OF
SEASONAL NORMS THROUGH THE WEEK.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 30 45 41 64 44 / 5 0 0 5 10
WACO, TX 31 51 39 65 46 / 5 0 0 0 10
PARIS, TX 27 44 34 57 43 / 5 0 0 5 10
DENTON, TX 25 43 37 62 41 / 5 0 0 5 5
MCKINNEY, TX 27 44 36 61 43 / 5 0 0 5 10
DALLAS, TX 31 45 41 63 45 / 5 0 0 5 10
TERRELL, TX 30 46 37 61 46 / 5 0 0 5 10
CORSICANA, TX 32 50 39 64 48 / 5 0 0 5 20
TEMPLE, TX 32 54 39 66 49 / 5 0 0 0 10
MINERAL WELLS, TX 28 46 36 65 38 / 5 0 0 0 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/58
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
611 AM CST SUN JAN 17 2016
.AVIATION...
VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH MONDAY
MORNING.
SOME PATCHY SHALLOW FOG/FREEZING FOG IS EXPECTED AROUND NORTH AND
CENTRAL TEXAS THIS MORNING BUT VISIBILITIES SHOULD REMAIN ABOVE 5
MILES AT ALL TERMINALS.
HIGH CLOUDS WILL INCREASE ACROSS NORTH AND CENTRAL TEXAS TODAY AS
A FAST MOVING SHORTWAVE APPROACHES FROM THE WEST. THE SHORTWAVE
TROUGH AXIS WILL MOVE EAST OF THE INTERSTATE 35 CORRIDOR THIS
EVENING AND ALLOW A COLD FRONT TO MOVE SOUTH THROUGH THE REGION.
SOUTHERLY WINDS TODAY WILL BECOME SOUTHEAST BY LATE AFTERNOON.
THE WIND WILL TURN TO THE NORTHEAST AFTER THE FRONT MOVES THROUGH
BETWEEN 5Z AND 7Z TONIGHT. WIND SPEEDS THROUGH MONDAY MORNING
WILL REMAIN BELOW 12 KNOTS.
79
&&
.PREV DISCUSSION... /ISSUED 301 AM CST SUN JAN 17 2016/
COLD MORNING IN PROGRESS ACROSS NORTH TEXAS AS A SURFACE HIGH
PRESSURE CENTER MOVES ACROSS THE REGION. WINDS HAVE GONE CALM IN
MANY LOCATIONS AND SURFACE MOISTURE LINGERS. THIS HAS RESULTED IN
AREAS OF SHALLOW FOG IN SOME LOCATIONS. IN OTHERS...WHERE T/TD
SPREADS ARE A LITTLE HIGHER...THICK FROST HAS DEVELOPED. THE FOG
SHOULD BE PATCHY AND SHALLOW AT BEST AND DOES NOT REALLY APPEAR
THAT IT WILL DEPOSIT ICE ON ANY AREA ROADS. AFTER A COLD START...
TEMPERATURES SHOULD REBOUND NICELY INTO THE LOW TO MID 50S BY THIS
AFTERNOON.
THE WARMUP WILL BE BRIEF AS ANOTHER COLD FRONT IS EXPECTED TO MOVE
THROUGH NORTH TEXAS TONIGHT INTO MONDAY MORNING. A LARGE UPPER LOW
WILL BE MOVING THROUGH THE GREAT LAKES REGION DURING THIS TIME AND
WILL ALLOW A 1030MB SURFACE HIGH TO BUILD SOUTHWARD THROUGH THE
PLAINS. TEMPERATURES ARE VERY COLD ACROSS THE UPPER PLAINS WITH
READINGS IN THE -10 TO -20F RANGE ACROSS PARTS OF THE DAKOTAS AND
MINNESOTA. WHILE THE BRUNT OF THE COLDEST AIR WILL STAY WELL TO
OUR NORTHEAST...THE PATTERN IS FAVORABLE TO ALLOW SHALLOW VERY
COLD AIR TO SPILL SOUTHWARD THROUGH THE PLAINS TODAY. AS IS
TYPICAL WITH VERY SHALLOW COLD AIR...THE MODELS ARE USUALLY TOO
WARM WITH TEMPERATURES DUE TO THEIR LACK OF LOW LEVEL RESOLUTION.
THE LATEST HIGH RESOLUTION RAP GUIDANCE DOES GIVE A SMALL HINT
THAT THE AIR MAY BE COLDER ON MONDAY ACROSS NORTH TEXAS THAN
CURRENTLY INDICATED BY THE GFS/NAM/ECMWF. THE LATEST RUN HAS
TEMPERATURES ACROSS PARTS OF CENTRAL OKLAHOMA IN THE LOW 20S ON
SUNDAY EVENING. THIS IS ABOUT 10 DEGREES COLDER THAN THE CURRENT
MOS GUIDANCE. WITH THAT IN MIND...WILL UNDERCUT THE MOS HIGHS FOR
MONDAY...PARTICULARLY NORTH OF I-20. WHILE COLD AIR WILL SPILL
INTO NORTH TEXAS...THE TRAJECTORY OF THE SURFACE HIGH AND THE
PROGRESSIVE NATURE OF THE UPPER PATTERN WILL ENSURE THAT IT WILL
BE SHORT LIVED ACROSS THE REGION. MOSTLY SUNNY SKIES AND A RETURN
TO SOUTHERLY FLOW LATE IN THE DAY ON MONDAY WILL LIKELY MIX SOME
OF THE COLDER AIR BEFORE THE SUN SETS. TEMPERATURES ARE LIKELY TO
BE IN THE LOW/MID 40S ACROSS THE NORTHERN HALF OF THE CWA WITH
UPPER 40S AND LOWER 50S SOUTH OF I-20.
THERE WILL BE SEVERAL SHORTWAVE TROUGHS THAT MOVE THROUGH THE
PLAINS THROUGH NEXT WEEK AND TIMING EACH ONE IS PROVING TO BE
RATHER DIFFICULT. THERE IS STILL QUITE A BIT OF SPREAD IN MODEL
GUIDANCE THROUGH THE END OF THE WEEK. IT DOES APPEAR THAT LOW
LEVEL FLOW WILL BECOME MORE SOUTH/SOUTHWEST ON TUESDAY WHICH WILL
ALLOW FOR A QUICK WARMUP IN TEMPERATURES BACK INTO THE 60S. A WEAK
COLD FRONT WILL MOVE THROUGH ON WEDNESDAY WITH ANOTHER COOL DOWN
BACK TOWARD SEASONAL NORMS. THERE IS A SMALL CHANCE FOR SHOWERS
ALONG THIS FRONT...MAINLY IN OUR SOUTH/SOUTHEAST COUNTIES ALTHOUGH
MOISTURE IS SOMEWHAT LIMITED. SLIGHTLY BETTER RAIN CHANCES APPEAR
TO ARRIVE LATE WEDNESDAY INTO EARLY THURSDAY AS A STRONG SHORTWAVE
MOVES THROUGH THE SOUTHERN PLAINS. THIS RESULTS IN ANOTHER SURFACE
LOW TRACKING ACROSS NORTH TEXAS WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS EXPECTED TO DEVELOP ON THE EAST SIDE OF THE
LOW. A QUICK LOOK AT THE 00Z ENSEMBLE GUIDANCE INDICATES THIS
SHORTWAVE AND ASSOCIATED SURFACE FEATURES IN MOST OF THE ENSEMBLE
MEMBERS...HOWEVER THE TRACK IS QUITE VARIED WITH ABOUT HALF OF
THE GUIDANCE INDICATING RAIN/STORMS ACROSS OUR AREA...AND THE
OTHER HALF FARTHER EAST INTO THE ARKLATEX. THIS RESULTS IN A LOWER
OVERALL CONFIDENCE IN RAIN MIDWEEK BUT WE WILL MAINTAIN 20/30 POPS
LATE WEDNESDAY INTO THURSDAY WITH BEST CHANCES EAST OF INTERSTATE
35.
TEMPERATURES WILL GENERALLY REMAIN WITHIN 5 DEGREES OR SO OF
SEASONAL NORMS THROUGH THE WEEK.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 54 30 45 41 64 / 0 5 0 0 5
WACO, TX 54 31 51 39 65 / 0 5 0 0 0
PARIS, TX 50 27 44 34 57 / 0 5 0 0 5
DENTON, TX 52 25 43 37 62 / 0 5 0 0 5
MCKINNEY, TX 51 27 44 36 61 / 0 5 0 0 5
DALLAS, TX 53 31 45 41 63 / 0 5 0 0 5
TERRELL, TX 52 30 46 37 61 / 0 5 0 0 5
CORSICANA, TX 53 32 50 39 64 / 0 5 0 0 5
TEMPLE, TX 54 32 54 39 66 / 0 5 0 0 0
MINERAL WELLS, TX 56 28 46 36 65 / 0 5 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
79/91
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
301 AM CST SUN JAN 17 2016
.DISCUSSION...
COLD MORNING IN PROGRESS ACROSS NORTH TEXAS AS A SURFACE HIGH
PRESSURE CENTER MOVES ACROSS THE REGION. WINDS HAVE GONE CALM IN
MANY LOCATIONS AND SURFACE MOISTURE LINGERS. THIS HAS RESULTED IN
AREAS OF SHALLOW FOG IN SOME LOCATIONS. IN OTHERS...WHERE T/TD
SPREADS ARE A LITTLE HIGHER...THICK FROST HAS DEVELOPED. THE FOG
SHOULD BE PATCHY AND SHALLOW AT BEST AND DOES NOT REALLY APPEAR
THAT IT WILL DEPOSIT ICE ON ANY AREA ROADS. AFTER A COLD START...
TEMPERATURES SHOULD REBOUND NICELY INTO THE LOW TO MID 50S BY THIS
AFTERNOON.
THE WARMUP WILL BE BRIEF AS ANOTHER COLD FRONT IS EXPECTED TO MOVE
THROUGH NORTH TEXAS TONIGHT INTO MONDAY MORNING. A LARGE UPPER LOW
WILL BE MOVING THROUGH THE GREAT LAKES REGION DURING THIS TIME AND
WILL ALLOW A 1030MB SURFACE HIGH TO BUILD SOUTHWARD THROUGH THE
PLAINS. TEMPERATURES ARE VERY COLD ACROSS THE UPPER PLAINS WITH
READINGS IN THE -10 TO -20F RANGE ACROSS PARTS OF THE DAKOTAS AND
MINNESOTA. WHILE THE BRUNT OF THE COLDEST AIR WILL STAY WELL TO
OUR NORTHEAST...THE PATTERN IS FAVORABLE TO ALLOW SHALLOW VERY
COLD AIR TO SPILL SOUTHWARD THROUGH THE PLAINS TODAY. AS IS
TYPICAL WITH VERY SHALLOW COLD AIR...THE MODELS ARE USUALLY TOO
WARM WITH TEMPERATURES DUE TO THEIR LACK OF LOW LEVEL RESOLUTION.
THE LATEST HIGH RESOLUTION RAP GUIDANCE DOES GIVE A SMALL HINT
THAT THE AIR MAY BE COLDER ON MONDAY ACROSS NORTH TEXAS THAN
CURRENTLY INDICATED BY THE GFS/NAM/ECMWF. THE LATEST RUN HAS
TEMPERATURES ACROSS PARTS OF CENTRAL OKLAHOMA IN THE LOW 20S ON
SUNDAY EVENING. THIS IS ABOUT 10 DEGREES COLDER THAN THE CURRENT
MOS GUIDANCE. WITH THAT IN MIND...WILL UNDERCUT THE MOS HIGHS FOR
MONDAY...PARTICULARLY NORTH OF I-20. WHILE COLD AIR WILL SPILL
INTO NORTH TEXAS...THE TRAJECTORY OF THE SURFACE HIGH AND THE
PROGRESSIVE NATURE OF THE UPPER PATTERN WILL ENSURE THAT IT WILL
BE SHORT LIVED ACROSS THE REGION. MOSTLY SUNNY SKIES AND A RETURN
TO SOUTHERLY FLOW LATE IN THE DAY ON MONDAY WILL LIKELY MIX SOME
OF THE COLDER AIR BEFORE THE SUN SETS. TEMPERATURES ARE LIKELY TO
BE IN THE LOW/MID 40S ACROSS THE NORTHERN HALF OF THE CWA WITH
UPPER 40S AND LOWER 50S SOUTH OF I-20.
THERE WILL BE SEVERAL SHORTWAVE TROUGHS THAT MOVE THROUGH THE
PLAINS THROUGH NEXT WEEK AND TIMING EACH ONE IS PROVING TO BE
RATHER DIFFICULT. THERE IS STILL QUITE A BIT OF SPREAD IN MODEL
GUIDANCE THROUGH THE END OF THE WEEK. IT DOES APPEAR THAT LOW
LEVEL FLOW WILL BECOME MORE SOUTH/SOUTHWEST ON TUESDAY WHICH WILL
ALLOW FOR A QUICK WARMUP IN TEMPERATURES BACK INTO THE 60S. A WEAK
COLD FRONT WILL MOVE THROUGH ON WEDNESDAY WITH ANOTHER COOL DOWN
BACK TOWARD SEASONAL NORMS. THERE IS A SMALL CHANCE FOR SHOWERS
ALONG THIS FRONT...MAINLY IN OUR SOUTH/SOUTHEAST COUNTIES ALTHOUGH
MOISTURE IS SOMEWHAT LIMITED. SLIGHTLY BETTER RAIN CHANCES APPEAR
TO ARRIVE LATE WEDNESDAY INTO EARLY THURSDAY AS A STRONG SHORTWAVE
MOVES THROUGH THE SOUTHERN PLAINS. THIS RESULTS IN ANOTHER SURFACE
LOW TRACKING ACROSS NORTH TEXAS WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS EXPECTED TO DEVELOP ON THE EAST SIDE OF THE
LOW. A QUICK LOOK AT THE 00Z ENSEMBLE GUIDANCE INDICATES THIS
SHORTWAVE AND ASSOCIATED SURFACE FEATURES IN MOST OF THE ENSEMBLE
MEMBERS...HOWEVER THE TRACK IS QUITE VARIED WITH ABOUT HALF OF
THE GUIDANCE INDICATING RAIN/STORMS ACROSS OUR AREA...AND THE
OTHER HALF FARTHER EAST INTO THE ARKLATEX. THIS RESULTS IN A LOWER
OVERALL CONFIDENCE IN RAIN MIDWEEK BUT WE WILL MAINTAIN 20/30 POPS
LATE WEDNESDAY INTO THURSDAY WITH BEST CHANCES EAST OF INTERSTATE
35.
TEMPERATURES WILL GENERALLY REMAIN WITHIN 5 DEGREES OR SO OF
SEASONAL NORMS THROUGH THE WEEK.
DUNN
&&
.AVIATION...
/ISSUED 1123 PM CST SAT JAN 16 2016/
VFR SHOULD PREVAIL THROUGH THE PERIOD. GENERALLY CLEAR SKIES NOW
WILL GIVE WAY TO INCREASING HIGH CLOUDS SUNDAY MORNING. VERY LIGHT
WEST WINDS ARE EXPECTED TONIGHT...BUT THESE WILL BACK AROUND TO
THE SOUTHWEST BY SUNRISE AND TO THE SOUTH BY MID MORNING. SOUTH
WINDS AT 5 TO 10KT WILL PREVAIL SUNDAY AFTERNOON BUT WILL CONTINUE
TO BACK AROUND TO THE EAST AFTER SUNSET AND NORTHEAST IN ABOUT 24
HOURS AS THE NEXT COLD FRONT ARRIVES.
GIVEN THE LIGHT WINDS AND CLEAR SKIES TONIGHT...TEMPERATURES WILL
REACH THEIR DEWPOINTS. MOISTURE LOOKS A LITTLE TOO SHALLOW FOR ANY
LIGHT FOG OR VSBY REDUCTIONS AT TAF SITES...BUT FROST IS A GOOD
BET ON AIRCRAFT SITTING OUT OVERNIGHT. TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 54 30 45 41 64 / 0 5 0 0 5
WACO, TX 54 31 51 39 65 / 0 5 0 0 0
PARIS, TX 50 27 44 34 57 / 0 5 0 0 5
DENTON, TX 52 25 43 37 62 / 0 5 0 0 5
MCKINNEY, TX 51 27 44 36 61 / 0 5 0 0 5
DALLAS, TX 53 31 45 41 63 / 0 5 0 0 5
TERRELL, TX 52 30 46 37 61 / 0 5 0 0 5
CORSICANA, TX 53 32 50 39 64 / 0 5 0 0 5
TEMPLE, TX 54 32 54 39 66 / 0 5 0 0 0
MINERAL WELLS, TX 56 28 46 36 65 / 0 5 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
516 PM MST MON JAN 18 2016
.UPDATE...
ISSUED AT 512 PM MST MON JAN 18 2016
STILL GETTING SOME PRETTY STRONG WINDS OUT NEAR ARLINGTON ON
INTERSTATE 80 AT 5 PM THIS AFTERNOON. LATEST RADAR COMPOSITE
SHOWING ANOTHER BAND OF SNOW MOVING INTO CARBON COUNTY FROM THE
NORTHWEST. BECAUSE WE ARE SEEING STRONG WINDS AT 5PM...AND ANOTHER
BAND OF SNOW MOVING INTO THAT AREA...DECIDED TO EXTEND THE
ADVISORY THROUGH THE OVERNIGHT HOURS. GRANTED...WIND WILL EASE
THROUGH THE EVENING HOURS...BUT WE ARE STILL GOING TO SEE GUSTS TO
30 MPH ALONG WITH ANOTHER 2-3 INCHES OUT THERE. THUS THE
EXTENSION. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(LATE THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 315 PM MST MON JAN 18 2016
THE AFTERNOON WATER VAPOR LOOP REVEALED A RATHER AMPLIFIED PROGRESSIVE
LARGE SCALE FLOW ACROSS THE LOWER 48. UPPER RIDGE AXIS WAS SITUATED
JUST EAST OF THE FRONT RANGE...WITH A SHORTWAVE UPPER TROUGH AXIS
FROM WESTERN MT THROUGH EASTERN ID AND WESTERN UT. SURFACE BOUNDARY
SEPARATING COLDER AIRMASS FROM WARMER WESTERLY FLOW HAD FINALLY
MOVED INTO THE WESTERN NE PANHANDLE. TEMPERATURES RANGED FROM 25
AT CHADRON TO 45 AT CHEYENNE. TIGHT PRESSURE GRADIENT CONTINUED TO
GENERATE STRONG AND GUSTY WEST-SOUTHWEST WINDS ALONG THE I-80 CORRIDOR
WEST OF CHEYENNE...WITH BLOWING SNOW CREATING LIMITED VISIBILITY
AND ICY ROADWAYS. PEAK GUSTS HAVE BEEN AROUND 55 MPH AT ARLINGTON
AND HALLECK RIDGE TO NAME A FEW. A FEW LIGHT RAIN/SNOW SHOWERS
DEVELOPED EAST OF CHEYENNE INTO THE SOUTHERN NE PANHANDLE.
12Z/18Z SHORT RANGE MODELS ARE IN GOOD AGREEMENT PROGGING THE SHORTWAVE
TROUGH TO THE WEST TO MOVE SMARTLY EAST ACROSS THE CWA TONIGHT AND
EARLY TUESDAY MORNING. RATHER STRONG WESTERLY FLOW AT MOUNTAIN
LEVEL AND QUICK SHOT OF PACIFIC MOISTURE WILL BRING BRIEF PERIODS
OF MODERATE TO HEAVY SNOW TO THE WEST FACING SLOPES OF THE HIGHER
TERRAIN TONIGHT. SNOW RATIOS INCREASE TO 15-20:1 WITH LIQUID
EQUIVALENTS OF 0.25 TO 0.33 INCHES. GENERALLY FOLLOWED WPC GUIDANCE
WITH 3-4 INCHES NORTH LARAMIE AND SNOWY RANGES...TO AS MUCH AS 5-7
INCHES SIERRA MADRE RANGE. ISSUED A WINTER WEATHER ADVISORY FOR
THE SIERRA MADRE RANGE VALID 5 PM THIS AFTERNOON UNTIL 5 AM TUESDAY.
WINDS WILL BE DIMINISHING BEGINNING THIS EVENING. PEAK GUSTS DURING
THE SNOW EVENT WILL BE 15-25 KT... SO BLOWING SNOW WILL NOT BE
MUCH OF AN ISSUE FOR THE MOUNTAINS TONIGHT. THE SNOW WILL END FOR
THE PLAINS...BUT LINGER OVER THE MOUNTAINS TUESDAY MORNING. HIGH
TEMPERATURES WILL RANGE FROM THE UPPER 20S TO UPPER 30S.
UPSTREAM SHORTWAVE RIDGE QUICKLY SHIFTS EAST ACROSS WY AND HIGH
PLAINS TUESDAY AFTERNOON...FOLLOWED BY THE NEXT PACIFIC SHORTWAVE
TUESDAY NIGHT AND WEDNESDAY. THE CRAIG-CASPER 700/850MB GRADIENTS
RISE ABOVE 50 METERS LATE TUESDAY NIGHT...PEAKING 65-70 METERS
WEDNESDAY MORNING. THE GFS/NAM 700MB WINDS PEAK AROUND 50 KT ALONG
AND WEST OF THE LARAMIE RANGE BY WEDNESDAY MORNING. CONFIDENCE IS
LOW TO MODERATE AT THIS TIME FOR HIGH WIND EVENT. LATER SHIFTS CAN
LOOK AT THIS POTENTIAL. SNOW WILL ONCE AGAIN DEVELOP AND INCREASE
IN COVERAGE AND INTENSITY OVER THE HIGHER TERRAIN OF CARBON COUNTY
TUESDAY NIGHT AND WEDNESDAY MORNING. THIS SYSTEM LOOKS MORE
DYNAMIC THAN TONIGHT`S AND WE COULD BE DEALING WITH WINTER STORM
HEADLINES WITH THE POTENTIAL FOR STRONG GUSTY WINDS AND LOCALLY
HEAVY SNOWFALL. HIGH TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES
MILDER THAN TUESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 215 PM MST MON JAN 18 2016
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE TRACK
OF THE SHORTWAVES MOVING THROUGH THE AREA WEDNESDAY NIGHT THROUGH
THURSDAY.
WEDNESDAY NIGHT-THURSDAY MORNING:
A FAIRLY PROGRESSIVE ALBEIT NEGATIVELY TILTED SHORTWAVE IS PROGGED
TO MOVE SOUTHEAST THROUGH WYOMING ON WEDNESDAY NIGHT. THIS FEATURE
MAY BRING A GOOD CHANCE OF SNOW TO MOST OF THE AREA. THE MAIN AREA
OF CONCERN APPEARS TO BE AROUND ARLINGTON WHERE THEY WILL EXPERIENCE
A COMBINATION OF SNOW AND BLOWING SNOW ESPECIALLY WEDNESDAY EVENING.
THE SNOW/BLOWING SNOW SHOULD BECOME A LESS OF CONCERN AFTER MIDNIGHT
AS THE SNOW AND WIND SPEEDS GRADUALLY DIMINISH. THE REST OF THE AREA
WILL SEE THE BEST CHANCE OF SNOW AFTER THE FRONTAL BOUNDARY PASSES
THROUGH. AT THIS POINT...SNOWFALL AMOUNTS LOOK TO BE ON THE LIGHT
SIDE.
THURSDAY AFTERNOON-MONDAY:
A WARMUP IS EXPECTED TO COMMENCE OVER THE REGION AS AN UPPER LEVEL
RIDGE BUILDS OVER THE AREA. THIS UPPER LEVEL RIDGE WILL RESULT IN
DRY CONDITIONS WITH HIGHS GENERALLY IN THE 30S WEST OF THE LARAMIE
RANGE AND 40S EAST. SOME PLACES IN THE NORTH PLATTE VALLEY MAY
EVEN SEE 50. HOWEVER...ALONG WITH THAT WARMUP WIND SPEEDS WILL BE
ON THE INCREASE ACROSS THE WIND CORRIDORS OF WYOMING. THE NEXT
CHANCE OF PRECIPITATION IS PROGGED TO MOVE INTO THE AREA SATURDAY
NIGHT INTO SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 440 PM MST MON JAN 18 2016
THE MAIN CONCERN THIS EVENING CONTINUES TO BE THE POTENTIAL FOR
SNOW/BLOWING SNOW ESPECIALLY AROUND RWL TAF SITE TONIGHT. LATEST
WEBCAMS WAS SHOWING CONDITIONS BEGINNING TO DETERIORATE WEST OF
RWL. WOULD EXPECT THE SNOW TO START MOVING INTO RWL DURING THE
NEXT HOUR OR SO AND PERSIST MOST OF THE NIGHT. FURTHER EAST...THE
BULK OF THE SNOW SHOULD STILL START OUT IN LAR/CYS AND THE
NEBRASKA PANHANDLE AFTER 06Z. THE EXCEPTION IS IN BFF WHERE THE
SNOW MAY COMMENCE A LITTLE EARLIER (02Z). CURRENT RADAR LOOP IS
SHOWING INDICATIONS OF THAT SNOW DEVELOPING IN THAT REGION.
OTHERWISE...THE HRRR IS INDICATING THAT THE SNOW SHOULD ONLY LAST
A FEW HOURS OR SO BEFORE ENDING. CEILINGS MAY DROP TO THE IFR/MVFR
CATEGORY BRIEFLY DURING THE SNOWFALL. HOWEVER...THE MAIN QUESTION
WILL BE HOW LONG THE MVFR CEILINGS WILL LAST. AT THIS POINT...WE
ARE NOT REAL CONFIDENT THEY WILL LAST AS LONG AS THE HRRR EXPECTS
ESPECIALLY WITH THE POTENTIAL FOR DOWNSLOPE FLOW KICKING IN DURING
THE MORNING. IN FACT...WE ARE EXPECTING MVFR CEILINGS TO ERODE BY
16Z OR SO AT ALL TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 154 PM MST MON JAN 18 2016
FIRE WEATHER CONCERNS WILL BE MINIMAL THIS WEEK WITH COOL TO MILD
TEMPERATURES AND MOIST FUELS IN PLACE. AN ACTIVE JET STREAM WILL
BRING A SERIES OF UPPER LEVEL DISTURBANCES WITH PERIODIC CHANCES
FOR PRECIPITATION AND GUSTY WINDS...ESPECIALLY TO SOUTHEAST WYOMING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL 5 AM MST TUESDAY FOR WYZ110-112.
NE...NONE.
&&
$$
UPDATE...GCC
SHORT TERM...MAJ
LONG TERM...REC
AVIATION...REC
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
501 PM MST MON JAN 18 2016
.SHORT TERM...(LATE THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 315 PM MST MON JAN 18 2016
THE AFTERNOON WATER VAPOR LOOP REVEALED A RATHER AMPLIFIED PROGRESSIVE
LARGE SCALE FLOW ACROSS THE LOWER 48. UPPER RIDGE AXIS WAS SITUATED
JUST EAST OF THE FRONT RANGE...WITH A SHORTWAVE UPPER TROUGH AXIS
FROM WESTERN MT THROUGH EASTERN ID AND WESTERN UT. SURFACE BOUNDARY
SEPARATING COLDER AIRMASS FROM WARMER WESTERLY FLOW HAD FINALLY
MOVED INTO THE WESTERN NE PANHANDLE. TEMPERATURES RANGED FROM 25
AT CHADRON TO 45 AT CHEYENNE. TIGHT PRESSURE GRADIENT CONTINUED TO
GENERATE STRONG AND GUSTY WEST-SOUTHWEST WINDS ALONG THE I-80 CORRIDOR
WEST OF CHEYENNE...WITH BLOWING SNOW CREATING LIMITED VISIBILITY
AND ICY ROADWAYS. PEAK GUSTS HAVE BEEN AROUND 55 MPH AT ARLINGTON
AND HALLECK RIDGE TO NAME A FEW. A FEW LIGHT RAIN/SNOW SHOWERS
DEVELOPED EAST OF CHEYENNE INTO THE SOUTHERN NE PANHANDLE.
12Z/18Z SHORT RANGE MODELS ARE IN GOOD AGREEMENT PROGGING THE SHORTWAVE
TROUGH TO THE WEST TO MOVE SMARTLY EAST ACROSS THE CWA TONIGHT AND
EARLY TUESDAY MORNING. RATHER STRONG WESTERLY FLOW AT MOUNTAIN
LEVEL AND QUICK SHOT OF PACIFIC MOISTURE WILL BRING BRIEF PERIODS
OF MODERATE TO HEAVY SNOW TO THE WEST FACING SLOPES OF THE HIGHER
TERRAIN TONIGHT. SNOW RATIOS INCREASE TO 15-20:1 WITH LIQUID
EQUIVALENTS OF 0.25 TO 0.33 INCHES. GENERALLY FOLLOWED WPC GUIDANCE
WITH 3-4 INCHES NORTH LARAMIE AND SNOWY RANGES...TO AS MUCH AS 5-7
INCHES SIERRA MADRE RANGE. ISSUED A WINTER WEATHER ADVISORY FOR
THE SIERRA MADRE RANGE VALID 5 PM THIS AFTERNOON UNTIL 5 AM TUESDAY.
WINDS WILL BE DIMINISHING BEGINNING THIS EVENING. PEAK GUSTS DURING
THE SNOW EVENT WILL BE 15-25 KT... SO BLOWING SNOW WILL NOT BE
MUCH OF AN ISSUE FOR THE MOUNTAINS TONIGHT. THE SNOW WILL END FOR
THE PLAINS...BUT LINGER OVER THE MOUNTAINS TUESDAY MORNING. HIGH
TEMPERATURES WILL RANGE FROM THE UPPER 20S TO UPPER 30S.
UPSTREAM SHORTWAVE RIDGE QUICKLY SHIFTS EAST ACROSS WY AND HIGH
PLAINS TUESDAY AFTERNOON...FOLLOWED BY THE NEXT PACIFIC SHORTWAVE
TUESDAY NIGHT AND WEDNESDAY. THE CRAIG-CASPER 700/850MB GRADIENTS
RISE ABOVE 50 METERS LATE TUESDAY NIGHT...PEAKING 65-70 METERS
WEDNESDAY MORNING. THE GFS/NAM 700MB WINDS PEAK AROUND 50 KT ALONG
AND WEST OF THE LARAMIE RANGE BY WEDNESDAY MORNING. CONFIDENCE IS
LOW TO MODERATE AT THIS TIME FOR HIGH WIND EVENT. LATER SHIFTS CAN
LOOK AT THIS POTENTIAL. SNOW WILL ONCE AGAIN DEVELOP AND INCREASE
IN COVERAGE AND INTENSITY OVER THE HIGHER TERRAIN OF CARBON COUNTY
TUESDAY NIGHT AND WEDNESDAY MORNING. THIS SYSTEM LOOKS MORE
DYNAMIC THAN TONIGHT`S AND WE COULD BE DEALING WITH WINTER STORM
HEADLINES WITH THE POTENTIAL FOR STRONG GUSTY WINDS AND LOCALLY
HEAVY SNOWFALL. HIGH TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES
MILDER THAN TUESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 215 PM MST MON JAN 18 2016
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE TRACK
OF THE SHORTWAVES MOVING THROUGH THE AREA WEDNESDAY NIGHT THROUGH
THURSDAY.
WEDNESDAY NIGHT-THURSDAY MORNING:
A FAIRLY PROGRESSIVE ALBEIT NEGATIVELY TILTED SHORTWAVE IS PROGGED
TO MOVE SOUTHEAST THROUGH WYOMING ON WEDNESDAY NIGHT. THIS FEATURE
MAY BRING A GOOD CHANCE OF SNOW TO MOST OF THE AREA. THE MAIN AREA
OF CONCERN APPEARS TO BE AROUND ARLINGTON WHERE THEY WILL EXPERIENCE
A COMBINATION OF SNOW AND BLOWING SNOW ESPECIALLY WEDNESDAY EVENING.
THE SNOW/BLOWING SNOW SHOULD BECOME A LESS OF CONCERN AFTER MIDNIGHT
AS THE SNOW AND WIND SPEEDS GRADUALLY DIMINISH. THE REST OF THE AREA
WILL SEE THE BEST CHANCE OF SNOW AFTER THE FRONTAL BOUNDARY PASSES
THROUGH. AT THIS POINT...SNOWFALL AMOUNTS LOOK TO BE ON THE LIGHT
SIDE.
THURSDAY AFTERNOON-MONDAY:
A WARMUP IS EXPECTED TO COMMENCE OVER THE REGION AS AN UPPER LEVEL
RIDGE BUILDS OVER THE AREA. THIS UPPER LEVEL RIDGE WILL RESULT IN
DRY CONDITIONS WITH HIGHS GENERALLY IN THE 30S WEST OF THE LARAMIE
RANGE AND 40S EAST. SOME PLACES IN THE NORTH PLATTE VALLEY MAY
EVEN SEE 50. HOWEVER...ALONG WITH THAT WARMUP WIND SPEEDS WILL BE
ON THE INCREASE ACROSS THE WIND CORRIDORS OF WYOMING. THE NEXT
CHANCE OF PRECIPITATION IS PROGGED TO MOVE INTO THE AREA SATURDAY
NIGHT INTO SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 440 PM MST MON JAN 18 2016
THE MAIN CONCERN THIS EVENING CONTINUES TO BE THE POTENTIAL FOR
SNOW/BLOWING SNOW ESPECIALLY AROUND RWL TAF SITE TONIGHT. LATEST
WEBCAMS WAS SHOWING CONDITIONS BEGINNING TO DETEORIATE WEST OF
RWL. WOULD EXPECT THE SNOW TO START MOVING INTO RWL DURING THE
NEXT HOUR OR SO AND PERSIST MOST OF THE NIGHT. FURTHER EAST...THE
BULK OF THE SNOW SHOULD STILL START OUT IN LAR/CYS AND THE
NEBRASKA PANHANDLE AFTER 06Z. THE EXCEPTION IS IN BFF WHERE THE
SNOW MAY COMMENCE A LITTLE EARLIER (02Z). CURRENT RADAR LOOP IS
SHOWING INDICATIONS OF THAT SNOW DEVELOPING IN THAT REGION.
OTHERWISE...THE HRRR IS INDICATING THAT THE SNOW SHOULD ONLY LAST
A FEW HOURS OR SO BEFORE ENDING. CEILINGS MAY DROP TO THE IFR/MVFR
CATEGORY BRIEFLY DURING THE SNOWFALL. HOWEVER...THE MAIN QUESTION
WILL BE HOW LONG THE MVFR CEILINGS WILL LAST. AT THIS POINT...WE
ARE NOT REAL CONFIDENT THEY WILL LAST AS LONG AS THE HRRR EXPECTS
ESPECIALLY WITH THE POTENTIAL FOR DOWNSLOPE FLOW KICKING IN DURING
THE MORNING. IN FACT...WE ARE EXPECTING MVFR CEILINGS TO ERODE BY
16Z OR SO AT ALL TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 154 PM MST MON JAN 18 2016
FIRE WEATHER CONCERNS WILL BE MINIMAL THIS WEEK WITH COOL TO MILD
TEMPERATURES AND MOIST FUELS IN PLACE. AN ACTIVE JET STREAM WILL
BRING A SERIES OF UPPER LEVEL DISTURBANCES WITH PERIODIC CHANCES
FOR PRECIPITATION AND GUSTY WINDS...ESPECIALLY TO SOUTHEAST WYOMING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL 5 AM MST TUESDAY FOR WYZ110.
WINTER WEATHER ADVISORY UNTIL 5 AM MST TUESDAY FOR WYZ112.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...REC
AVIATION...REC
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
301 PM MST SUN JAN 17 2016
.SHORT TERM...(LATE THIS AFTERNOON THROUGH TUESDAY)
ISSUED AT 300 PM MST SUN JAN 17 2016
AFTERNOON WATER VAPOR IMAGERY REVEALED A DEEP POLAR VORTEX NEARLY
STATIONARY NORTH OF THE GREAT LAKES. A HIGH AMPLITUDE RIDGE WAS
SITUATED FROM THE PACIFIC NORTHWEST SOUTH THROUGH CA. SHORTWAVE
DIVED SOUTHEAST ACROSS THE FRONT RANGE AND PLAINS OF WY/NE INTO
INTO EASTERN CO AND WESTERN KS. WEAKENING VORT LOBE EXTENDING
NORTHWEST INTO WESTERN NE/SD WAS PRODUCING BANDS OF VERY LIGHT
SNOW OR FLURRIES. FURTHER WEST...LIGHT SNOW CONTINUED OVER THE
SNOWY/SIERRA MADRE RANGES. LATEST SURFACE ANALYSIS PLACED THE
ARCTIC FRONT FROM NEAR PINE BLUFFS NORTHWEST TO WEST OF DOUGLAS
WY. WESTERLY DOWNSLOPE WINDS LEE OF CENTRAL/SOUTHERN LARAMIE
RANGE AND BREAKS IN CLOUD COVER PUSHED THE MERCURY IN THE MID-UPR
30S...WHILE CHADRON...AND SIDNEY REMAINED IN THE TEENS. WIND GUSTS
ALONG THE I-80 CORRIDOR HAVE AVERAGED 35-45 MPH. WYDOT WEBCAMS
INDICATED LOWERED VISIBILITY IN BLOWING SNOW BETWEEN LARAMIE AND
RAWLINS.
MAIN FORECAST CHALLENGES WILL DEAL WITH SNOW CHANCES AND WINDS.
12Z/18Z SHORT RANGE MODEL GUIDANCE IS IN GOOD AGREEMENT PROGGING
THE POLAR VORTEX TO MOVE EAST TOWARD NEW ENGLAND...WITH THE RIDGE
OUT WEST WEAKENING AS IT SLIDES EAST ACROSS THE FRONT RANGE AND
PLAINS MONDAY. THE NEXT PACIFIC TROUGH MOVING ASHORE IN THE
NORTHWEST TONIGHT...DEEPENS AS IT TRACKS EAST ACROSS THE ROCKIES
AND PLAINS MONDAY NIGHT AND TUESDAY.
THE ARCTIC FRONT OVER THE SOUTHEAST WY PLAINS GETS DISPLACED TO
THE EAST AS WEST-SOUTHWEST FLOW INCREASES AHEAD OF THE NEXT
TROUGH MONDAY. CRAIG-CASPER HEIGHT GRADIENT PEAKS AROUND 50-55
METERS LATE TONIGHT AND MONDAY MORNING...WITH 700MB WINDS NEAR
50 KT FROM THE ARLINGTON AREA SOUTHEAST TO THE SOUTHERN LARAMIE
RANGE. THUS...SUSTAINED WESTERLY WINDS WILL INCREASE TO 30-40
KT WITH GUSTS NEAR 50 KT POSSIBLE FOR WY ZONE 110 THROUGH AT
LEAST MONDAY AFTERNOON. THE STRONG WINDS WILL CONTINUE TO PRODUCE
AREAS OF BLOWING AND DRIFTING SNOW WITH VISIBILITIES REDUCED TO
1/ MILE OR LESS ALONG THE I-80 CORRIDOR BETWEEN LARAMIE AND
RAWLINS. WENT AHEAD AND EXTENDED THE WINTER STORM WARNING FOR
BLOWING SNOW UNTIL 5 PM MONDAY. LIGHT SNOW WILL GRADUALLY TAPER
OFF OVER THE SNOWY/SIERRA MADRES TONIGHT WITH LESS THAN AN INCH
OF ADDITIONAL ACCUMULATION. SNOW WILL THEN INCREASE LATER MONDAY
AFTERNOON WEST OF A DOUGLAS TO LARAMIE LINE WITH THE APPROACH
OF THE NEXT PACIFIC TROUGH. SNOW INCREASES IN COVERAGE AND
INTENSITY MONDAY NIGHT WITH THE PASSAGE OF THE TROUGH. THE
SNOWY/SIERRA MADRES COULD RECEIVE ANOTHER 2-4 INCHES OF SNOW...
WITH LESS THAN AN INCH ELSEWHERE. SNOW WILL END FOR ALL BUT
THE SNOWY/SIERRA MADRES TUESDAY WITH THE QUICK EXIT OF THE
TROUGH. WINDS WILL GRADUALLY DECREASE MONDAY NIGHT AND TUESDAY.
TEMPERATURES TONIGHT WILL RANGE FROM THE 0 TO 10 ABOVE FOR THE
NE PANHANDLE TO THE TEENS AND 20S SOUTHEAST WY. HIGHS MONDAY
WILL BE MILDER...WITH 40S I-25 CORRIDOR/FAR WESTERN NE PANHANDLE
AND 30S LARAMIE VALLEY AND EASTERN NE PANHANDLE. LOWS MONDAY NIGHT
WILL BE IN THE TEENS AND 20S. COOLER TUESDAY WITH HIGHS IN THE 20S
AND 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 300 PM MST SUN JAN 17 2016
ACTIVE WEATHER IN THE LONG TERM WITH WINDS AND SNOW POTENTIAL.
STARTING OFF TUESDAY NIGHT...GOING TO BE WINDY...WITH GFS 700MB
WINDS 45-50KTS ACROSS CARBON AND ALBANY COUNTIES. CRAIG TO CASPER
700MB GRADIENT OFF THE GFS PRETTY CLOSE TO 60MTRS...SO DO THINK
OUR WIND PRONE AREAS WILL HAVE A SHOT AT SEEING WARNING LEVEL
WINDS. DID INCREASE WINDS AT THESE LOCATIONS OVER GUIDANCE TO
REFLECT THIS THINKING.
WINDS STAY STRONG THROUGH MUCH OF WEDNESDAY BEFORE EASING SOME
TOWARDS 00Z. THEY BEGIN TO SHIFT NORTHWESTERLY...A DIRECTION NOT
FAVORABLE FOR BORDEAUX...BUT STILL ELEVATED FOR ARLINGTON AND THE
SOUTH LARAMIE RANGE. BEGIN TO SEE SOME SNOW MOVING BACK INTO OUR
WESTERN COUNTIES WEDNESDAY AFTERNOON/EVENING AS OUR NEXT SHORTWAVE
BEGINS TO PUSH INTO THE AREA. SNOWY AND SIERRA MADRE RANGES SHOULD
GET A DECENT SNOWFALL OUT OF THIS SYSTEM WITH SNOW PERSISTING FROM
WEDNESDAY MORNING THROUGH THURSDAY MORNING. GFS SHOWING PRETTY CLOSE
TO 3/4THS OF AN INCH QPF AND ECMWF AROUND 1/4TH. STILL A WAYS
OUT...BUT WINTER HEADLINES LOOKING TO BE NEEDED OUT THAT WAY FOR
THIS TIME FRAME.
AFTER THE PASSAGE OF THIS SHORTWAVE...WE ARE LOOKING AT A FAIRLY
LONG WINDY PERIOD WITH WARMER TEMPERATURES. GFS 700MB TEMPERATURES
CLIMB ABOVE FREEZING THURSDAY AND REMAIN ABOVE FREEZING THROUGH
FRIDAY. WESTERLY 700MB WINDS OF 35 TO 45KTS SHOULD ALLOW MANY AREAS
EAST OF THE LARAMIE RANGE TO WARM WELL ABOVE FREEZING IN
DOWNSLOPING FLOW.
NEXT SYSTEM ON TRACK FOR THE WEEKEND WITH BOTH THE GFS AND ECMWF
MOVING ANOTHER SHORTWAVE INTO OUR WESTERN COUNTIES SATURDAY
AFTERNOON. BROUGHT CHANCE POPS BACK INTO THE FORECAST SATURDAY NIGHT
INTO SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1011 AM MST SUN JAN 17 2016
AVIATION WEATHER CONCERNS SHIFTING INTO THE PANHANDLE THIS AFTERNOON.
BAND OF SNOW MOVING SOUTH OUT OF SOUTHWESTERN SOUTH DAKOTA WILL IMPACT
KCDR...KAIA AND KSNY WITH LOWER VISIBILITIES THAT COULD LAST THROUGH
THE AFTERNOON. COULD SEE FOG OUT THAT WAY THIS EVENING AS WELL WITH
WINDS GOING LIGHT AND VARIABLE. GENERALLY FOLLOWED HRRR GUIDANCE FOR
THE 18Z TAFS. WILL CONTINUE TO MONITOR CONDITIONS AND UPDATE AS NEEDED.
&&
.FIRE WEATHER...
ISSUED AT 150 PM MST SUN JAN 17 2016
NO FIRE WEATHER CONCERNS FOR THE NEXT FEW DAYS DUE TO SNOWFALL AND
COLD TEMPERATURES. DRIER...MILDER AND BREEZY TO WINDY WEATHER IS
FORECAST FOR THE MIDDLE TO END OF THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ112-114.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR WYZ113-
116.
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR WYZ110.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1014 AM MST SUN JAN 17 2016
.UPDATE...
ISSUED AT 912 AM MST SUN JAN 17 2016
WINTER WEATHER ADVISORY FOR SOUTH LARAMIE RANGE FOOTHILLS...CENTRAL
AND EASTERN LARAMIE COUNTY EXPIRED AT 9 AM. RADAR TRENDS THE PAST
FEW HOURS SHOWED THE BAND OF LIGHT SNOW MOVED INTO NORTHEAST CO
WITH OCCASIONAL FLURRIES IN ITS WAKE. ANOTHER BAND OF LIGHT SNOW
EXTENDED FROM SOUTH CENTRAL MT THROUGH EAST CENTRAL WY INTO THE
NORTHERN NE PANHANDLE. NOT EXPECTING MUCH ACCUMULATION FROM THIS
BAND. LIGHT TO MODERATE SNOW CONTINUES TO FALL OVER THE SNOWY/SIERRA
MADRE AND SOUTH LARAMIE RANGES AT MID MORNING AND WILL CONTINUE
INTO THE EARLY AFTERNOON BEFORE TAPERING OFF. COULD SEE AN ADDITIONAL
1 TO 3 INCHES FOR THESE AREAS. WESTERLY WINDS CONTINUE TO GUST
BETWEEN 30 AND 40 MPH BETWEEN LARAMIE AND RAWLINS. I-80 REMAINS
CLOSED BOTH DIRECTIONS BETWEEN RAWLINS AND LARAMIE DUE TO CONSIDERABLE
BLOWING AND DRIFTING SNOW AND POOR VISIBILITY. HIGH TEMPERATURES
WERE LOWERED A FEW DEGREES FOR THE FAR NORTHEAST CWA...CHADRON TO
ALLIANCE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 513 AM MST SUN JAN 17 2016
THE BIGGEST CHALLENGE FOR THE NEAR TERM INVOLVES THE SNOW BAND THAT
DEVELOPED NW-SE ACROSS LARAMIE COUNTY EARLIER TONIGHT. THE COLD
FRONT LOOKS AS IF ITS STALLED WITHIN THE SOUTHERN LARAMIE RANGE
FOOTHILLS...WITH GOOD CONVERGENCE ALONG THE FRONT IN ADDITION TO
UPSLOPE FORCING. A LOOK AT MESOANALYSIS SHOWS SOME NEGATIVE EPV
LINED UP ALONG THE FRONT AS WELL...THUS NOT SURPRISED THE BAND
PERSISTED FOR MUCH OF THE NIGHT AND WAS RELATIVELY INTENSE. THE
BAND REMAINS IN PLACE ALONG THE I-80 AT THIS HOUR...ALTHOUGH IS
WEAKENING AND SLOWLY SLIDING SOUTH BASED ON RADAR. SO
FAR...ROUGHLY 3-4 INCHES OCCURRED HERE AT THE OFFICE AND EXPECT
SIMILAR TOTALS ACROSS MUCH OF THE COUNTY...ESPECIALLY THE SOUTHERN
HALF. ANOTHER 1 TO 2 INCHES IS POSSIBLE THROUGH THE MORNING WITH
THIS BAND...SO WENT EXPANDED THE WINTER WEATHER ADVISORY FOR ALL
OF LARAMIE COUNTY. THANKFULLY...WINDS ARE LIGHT SO DO NOT
ANTICIPATE BLOWING SNOW CONCERNS.
THE OTHER CHANGE TO HIGHLIGHTS WAS FOR THE SNOWY RANGE. UPGRADED TO
A WINTER STORM WARNING AS AN INITIAL LOOK AT SNOTEL OBS SHOWED SNOW
TOTALS ALREADY IN THE 6-12 INCH RANGE ACROSS THE MOUNTAIN RANGE.
WITH AT LEAST 4-6 MORE INCHES POSSIBLE THROUGH THE REST OF
TODAY...WENT WITH THE UPGRADE. OTHERWISE...HIGHLIGHTS ARE IN GOOD
SHAPE FOR NOW.
WIND GUSTS HAVE BEEN STEADY IN THE 30 TO 45 MPH RANGE IN THE
SOUTHERN LARAMIE RANGE AND ARLINGTON AREAS WITH OCCASIONAL GUSTS
TO 55 MPH AT ARLINGTON. VISIBILITIES ALONG I-80 BETWEEN ARLINGTON
AND SINCLAIR WITHIN SNOW AND BLOWING SNOW HAVE CONSISTENTLY BEEN
LESS THAN ONE MILE TONIGHT...WITH SOME IMPROVEMENT THIS MORNING AS
SNOWFALL IS LIKELY DIMINISHING. INTERSTATE 80 REMAINS CLOSED
BETWEEN RAWLINS AND LARAMIE AND IS EXPECTED TO BE CLOSED FOR AN
EXTENDED PERIOD. THERE ARE ADDITIONAL CLOSURES ELSEWHERE AS
WELL...BUT WILL NOT GET INTO DETAILS HERE. LIGHT SNOW HAS BEEN
REPORTED AT MANY OTHER LOCATIONS ACROSS SOUTHEAST WYOMING AND THE
SOUTHERN NEBRASKA PANHANDLE TOO...BUT EXPECT MOST OF THESE
LOCATIONS SAW JUST A TRACE...PERHAPS UP TO HALF INCH. GUSTY WINDS
AND LIGHT SNOW WILL CONTINUE THROUGH THE MORNING.
FOR THE REMAINDER OF TODAY...EXPECT SNOW TO STEADILY DIMINISH WHILE
WINDS REMAIN FAIRLY STEADY...PERHAPS INCREASING LATER TONIGHT.
THE CAG-CPR GRADIENT WILL STRENGTHEN TONIGHT AS THE COLD FRONT
BEGINS TO RETREAT EAST. 700-750 MB WINDS INCREASE TO ROUGHLY 40 TO
50 KTS IN THE WIND CORRIDOR DURING THIS TIME MEANING WINDS WILL
LIKELY BUMP BACK UP IN TO THE 45 TO 55 MPH RANGE MORE
CONSISTENTLY. BLOWING SNOW WILL REMAIN AN ISSUE...THUS THE CURRENT
WINTER HIGHLIGHTS MAY NEED TO BE EXTENDED DEPENDING ON HOW THE
SNOWPACK EVOLVES TODAY. OTHERWISE...WIND HIGHLIGHTS MAY NEED TO BE
CONSIDERED. MONDAY WILL CONTINUE TO BE BREEZY-WINDY AND WARMER AS
ZONAL FLOW TAKES OVER FOR A BRIEF PERIOD. THE NEXT SHORTWAVE
TROUGH WILL BRING A CHANCE FOR SNOW TO THE AREA MONDAY NIGHT.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 513 AM MST SUN JAN 17 2016
SOME LINGERING SNOW SHOWERS SHOULD CONTINUE OVER THE HIGHER MTNS
TUESDAY AND TUESDAY NIGHT WITH COOL AND DRY WEATHER EXPECTED
ELSEWHERE OVER THE CWA AS A SHORT UPPER RIDGE MOVES EAST ACROSS
THE REGION. NEXT SHORTWAVE IN THE PROGRESSIVE UPPER FLOW WILL THEN
SCOOT ACROSS THE AREA WEDS INTO WEDS NIGHT BRINGING A MINOR COOL
FRONT AS WELL AS ANOTHER ROUND OF SCTD SNOW SHOWERS. LARGER
AMPLITUDE UPPER RIDGE THEN APPROACHES AND MOVES BY THURSDAY
THROUGH FRIDAY ALLOWING FOR MILDER TEMPERATURES. THIS RIDGE
WEAKENS AND MOVES EAST ON SATURDAY WITH THE NEXT UPPER SHORTWAVE
BRINGING A RETURN OF SNOW SHOWER TO THE WESTERN CWA BY LATE IN THE
DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1011 AM MST SUN JAN 17 2016
AVIATION WEATHER CONCERNS SHIFTING INTO THE PANHANDLE THIS
AFTERNOON. BAND OF SNOW MOVING SOUTH OUT OF SOUTHWESTERN SOUTH
DAKOTA WILL IMPACT KCDR...KAIA AND KSNY WITH LOWER VISIBILITIES
THAT COULD LAST THROUGH THE AFTERNOON. COULD SEE FOG OUT THAT WAY
THIS EVENING AS WELL WITH WINDS GOING LIGHT AND VARIABLE.
GENERALLY FOLLOWED HRRR GUIDANCE FOR THE 18Z TAFS. WILL CONTINUE
TO MONITOR CONDITIONS AND UPDATE AS NEEDED.
&&
.FIRE WEATHER...
ISSUED AT 513 AM MST SUN JAN 17 2016
FIRE WEATHER CONCERNS WILL REMAIN MINIMAL THROUGH THE NEAR TERM
DUE TO RECENT ACCUMULATING SNOW AND COLD TEMPERATURES. WINDS WILL
REMAIN STRONG AT TIMES IN THE WIND PRONE AREAS THROUGH MONDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ110-
112-114.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR WYZ113-
116.
NE...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...RJM
LONG TERM...RE
AVIATION...GCC
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS MIAMI FL
316 AM EST TUE JAN 19 2016
.DISCUSSION...
MODELS REMAIN IN GOOD AGREEMENT WITH HIGH PRESSURE CONTINUING TO
BUILD OVER THE SOUTHEAST UNITED STATES. THERE IS AN AREA OF HIGH
CLOUDS THAT HAS BEEN STREAMING OVER SOUTH FLORIDA SINCE YESTERDAY.
AS A 500MB TROUGH PUSHES EAST OVER THE NEXT DAY, THE HIGH CLOUDS
SHOULD ALSO BEGIN TO EXIT THE REGION. FOR THE MOST PART, DRY
WEATHER FOR THE CWA. THE EXCEPTION IS SOME SHOWER ACTIVITY WELL
OFFSHORE, OVER THE ATLANTIC. THIS LOOKS TO BE ASSOCIATED WITH A
WEAK SURFACE TROUGH. IT IS NOT ANALYZED WELL IN THE SYNOPTIC
MODELS, BUT THE HRRR IS SHOWING IT AND SEEMS TO HAVE A GOOD HANDLE
ON THINGS.
THIS WEAK TROUGH WILL GET PUSH AWAY FROM SOUTH FLORIDA AS HIGH
PRESSURE BUILDS. ALSO, THE WIND WILL FIRST BEGIN TO RELAX THROUGH
THE DAY, THEN BEGIN A TURN TO THE NORTHEAST BY WEDNESDAY MORNING.
HOWEVER, THE AIR MASS WILL REMAIN DRY AND THE WEATHER WILL
CONTINUE TO BE QUIET THROUGH THE MIDDLE OF THE WEAK. THIS AIR MASS
IS ALSO FAIRLY COOL, AND WILL KEEP THE TEMPS ACROSS THE AREA BELOW
NORMAL FOR A FEW DAYS.
AS THE HIGH BUILDS FURTHER TO THE SOUTH, THE WIND WILL TURN MORE
TO THE EAST, PRETTY MUCH BY WEDNESDAY AFTERNOON. THIS WILL BRING
SOME MOISTURE BACK TO THE AREA, AND BEGIN TO MODIFY THE
TEMPERATURES. SO, AFTER A CHILLY START WEDNESDAY MORNING, WHICH
SHOULD SEE LOWS IN THE UPPER 30S WEST OF THE LAKE, LOW 50S OVER
THE SOUTHEAST FLORIDA METRO AREAS, THE AIR MASS WILL BEGIN A
WARMING TREND. HIGHS WEDNESDAY WILL BE AROUND 70, WITH THE
NORTHWEST PORTION OF THE CWA IN THE UPPER 60S AND THE SOUTHEAST
COAST IN THE LOW 70S.
ELSEWHERE ON WEDNESDAY AFTERNOON, A LOW PRESSURE SYSTEM WILL
DEVELOP LEEWARD OF THE ROCKIES, OVER THE HIGH PLAINS. THIS LOW
WILL BE OUR NEXT WEATHER MAKER FOR SOUTH FLORIDA. BY THURSDAY
AFTERNOON, WHICH WILL BE WARMER THAN WEDNESDAY, BUT STILL LOOKS
DRY, THE LOW WILL TRACK INTO THE SOUTHERN MISSISSIPPI VALLEY, BUT
REMAIN NORTH OF THE GULF. THIS WILL BEGIN TO TURN THE WIND MORE TO
THE SOUTH BY FRIDAY MORNING. THIS WILL BRING MOISTURE BACK, AS
WELL AS ALLOW THE AIR MASS TO WARM INTO THE MID TO UPPER 70S. THIS
WILL ALSO BRING OUR NEXT CHANCE FOR SHOWERS AND STORMS FROM
THURSDAY NIGHT, THROUGH FRIDAY, AND EVEN SOME REMNANT SHOWER
ACTIVITY FRIDAY NIGHT INTO SATURDAY MORNING.
FOR THIS NEXT SYSTEM, IT DOES TRACK FURTHER NORTH THAN THE SYSTEM
THIS PAST SUNDAY MORNING. ALSO, MODELS ARE INDICATING THAT THERE
SHOULD BE SHOWER ACTIVITY WELL AHEAD OF THE SYSTEM. THIS COULD
POTENTIALLY REDUCE INSTABILITY AHEAD OF THE COLD FRONT. THE GFS IS
NOT TOO EXCITED ABOUT THE AMOUNT OF CAPE BY FRIDAY MORNING, WITH
ONLY A FEW HUNDRED JOULES FRIDAY AFTERNOON. THERE IS A BROAD JET
STREAK WITH THE RIGHT EXIT QUADRANT IN THE VICINITY, LEADING TO
SOME CONVERGENCE ALOFT IN THIS GENERAL AREA. THE GFS DOES SHOW A
WEAK LOW LEVEL JET AT 850 MB AT ABOUT 40 KTS.SO, THE ELEMENTS JUST
DO NOT LOOK AS THOUGH THEY ARE LINING UP AS THEY DID WITH THE
LATEST SYSTEM. GFS SHOWS THE HELICITY TO BE A MAX OF 100 M^2*S^-2,
JUST AHEAD OF THE FRONT, NOTHING COMPARED TO THE 300-400 VALUES
FROM THE OTHER DAY. STILL, THERE COULD BE SHOWERS AND A FEW
THUNDERSTORMS THAT PRODUCE SOME GUSTY WIND AS THE FRONT PUSHES
THROUGH ON FRIDAY. THERE WILL BE A CONCERN ABOUT THE SUSTAINED,
NON-CONVECTIVE WIND FROM FRIDAY NIGHT THROUGH SATURDAY. MODEL
BLENDS ARE SHOWING WIND OVER THE MARINE AREAS TO BE NEARING 30KTS,
WITH HIGHER GUSTS, AND 15 TO 20 KTS OVER THE MAINLAND. THIS WILL
MEAN THERE WILL BE SOME MARINE CONCERNS FOR THIS PERIOD.
BEHIND THIS FRONT, ANOTHER COOLER AIR MASS WILL SETTLE IN OVER THE
CWA FOR THE REMAINDER OF THE WEEKEND, INTO THE BEGINNING OF NEXT
WEEK, WHICH SHOULD SEE QUIET WEATHER CONDITIONS.
&&
.AVIATION...
HIGH PRESSURE IS BUILDING OVER SOUTH FLORIDA. THIS WILL KEEP THE
WEATHER QUIET FOR THE TAF SITES, AS WELL AS VFR CONDITIONS THROUGH
THE TAF PERIOD. EVEN SO, THERE ARE SOME MID AND UPPER LEVEL CLOUDS
THAT ARE GIVING CIGS OF BKN045, AS WELL AS A DECK OF HIGH CLOUDS.
THE WIND WILL CONTINUE OUT OF THE NORTH TO NORTHWEST INTO THE
AFTERNOON, BEFORE TRYING TO TURN TO THE NORTHEAST.
&&
.MARINE...
MARINE CONDITIONS ARE HAZARDOUS FOR SMALL CRAFT TODAY. THIS IS DUE
TO A NORTHERLY WIND BETWEEN 15 AND 20 KTS OPPOSING THE GULF
STREAM, CAUSING SEAS OF 7 TO 8 FEET IN THE GULF STREAM. THE WIND
IS FORECAST TO SUBSIDE TONIGHT, WHICH WILL ALLOW SEAS TO SLOWLY
SUBSIDE BY TOMORROW MORNING. THERE IS A SMALL CRAFT ADVISORY OUT
FOR THE ATLANTIC WATERS. THERE IS ALSO AN AREA OF SHOWERS ORIENTED
NORTH SOUTH IN THE OFFSHORE ATLANTIC WATERS THAT SHOULD SLOWLY
SUBSIDE THIS MORNING. A COLD FRONT AT THE END OF THE WEEK WILL
BRING MARINE CONCERNS INTO THE FORECAST ONCE AGAIN. BESIDES
SHOWERS AND THUNDERSTORMS THAT WILL ACCOMPANY A COLD FRONT, THE
SUSTAINED WIND BEHIND THE FRONT FOR FRIDAY NIGHT INTO SATURDAY
WILL BE NEARING 30 KTS. THIS WILL MAKE FOR HAZARDOUS MARINE
CONDITIONS THIS WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 66 50 71 58 / 0 10 10 0
FORT LAUDERDALE 67 52 71 61 / 0 0 0 0
MIAMI 67 52 73 60 / 0 0 0 0
NAPLES 66 44 71 53 / 0 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ610-650-
651-670-671.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR GMZ656-657-
676.
&&
$$
SHORT TERM...13/SI
LONG TERM....13/SI
AVIATION...13/SI
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1139 PM CST MON JAN 18 2016
.UPDATE...
ISSUED AT 900 PM CST MON JAN 18 2016
The strato-cumulus and flurries in the southeast counties has
nearly departed into Indiana as of 9 pm. The clouds in our western
counties are positioned on the north side of a surface high
pressure, centered in southern IL to eastern Arkansas. Those
clouds are not being handled well at all in the HRRR nor RAP.
Satellite trends show some dissipation on the outer edges of the
narrow band of clouds as it slowly drifts eastward. Will continue
with the trend that before sunrise, that band of clouds will
mostly dissipate as cirrus clouds stream into western IL.
Low temps tonight will be closely tied to how soon those low
clouds dissipate. We are currently forecasting temps to drop
another 7-9 degrees from current readings in our west and
southwest, but that would not occur if clouds linger as late as
sunrise. Will stay the course with low temps, assuming clearing,
and keep lows around 6-7F in our SW and S, and -1F to +1F from
Galesburg to Lacon.
Looking ahead, snowfall still looks on track to begin southwest of
Springfield late Tuesday afternoon, with the bulk of the snowfall
occurring between 6 pm and 3 am. Amounts should be mainly in the 1
to 3 inch range, with the higher amounts south of a line from
Springfield to Effingham. The wave looks progressive, with snow
ending before 6 am in all of our counties, including those
bordering Indiana.
Updates this evening were mainly to sky grids, and weather grids
for flurries in the SE. Updated forecast info is already
available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 248 PM CST MON JAN 18 2016
A robust diurnal CU-field developed across central Illinois this
afternoon, mainly along and south of the I-72 corridor. Meanwhile,
a persistent band of low clouds extending from Minnesota into west-
central Illinois tried to push eastward, but generally stayed west
of a Macomb to Jacksonville line. The diurnal clouds will rapidly
dissipate toward sunset: however, the band of clouds further west
will likely persist into the evening. Models have not been picking
up on these clouds at all, with the HRRR 1-hour forecast suggesting
clear skies. Based on satellite loops, think they will inch
eastward into the Illinois River Valley over the next couple of
hours before gradually dissipating later in the evening. Will need
to monitor satellite trends closely to see if they spread further or
persist longer. At this time, will only bring them to a Galesburg
to just west of Springfield line this evening. Elsewhere, skies
will remain mostly clear through the night. Overnight low
temperatures will be in the single digits above zero across most of
the area, but will likely drop a couple degrees below zero across
the far north around Galesburg and Lacon.
.LONG TERM...(Tuesday through Monday)
ISSUED AT 248 PM CST MON JAN 18 2016
Arctic high pressure area will shift east of the CWA Tuesday and
allow a developing weather system in the southern plains to push
east and bring precip back into the area beginning late Tue
afternoon and continuing through Tue night, then ending Wed morning.
Temps thru the period will be cold enough for all snow, so question
will be how much snow and when will heaviest snow occur. The models
have trended slightly slower with the onset of the snow and this
makes sense given the current dryness of the lower layers and the
expected southeast winds tomorrow not bringing any moisture into the
area. So, believe snow will begin over most of the area after 6pm
tomorrow evening, though some light snow may begin in western IL
late tomorrow afternoon. Heaviest snowfall track should be from the
Jacksonville area to southeast IL, tomorrow evening through after
midnight. The main low will be tracking into AR late tomorrow night,
but system should be able to spread enough pcpn north into the area.
Models indicate good isentropic lift with this system with around
3g/kg of moisture being lifted. However, factors limiting the amount
of snowfall will be lack of low level moisture initially, system
will be weakening as it moves east, and system will be moving
through quickly. So snowfall thinking is 3-4 inches in western IL
will be the highest, decreasing to around 3 inches in the southeast,
and 2 to 2.5 inches along I-74. This matches up well with other
offices and thinking of the WWD graphics. Snow will continue into
Wed morning,but only in the east and southeastern parts of the CWA.
1/2 inch will still be possible in the Lawrenceville area before
ending by noon. Advisory will be likely in some part of the CWA, but
given most of the snow will be third period and still some
uncertainty on strength of system, will let overnight shift make
final decision on location of advisory.
A period of dry weather is then expected Wed night through Thursday
as this system pushes east and then next system moves out of the
plains toward the area. All models have finally come to some
agreement on the track of this next system and it appears that most
of the pcpn with it will be south of the CWA. Current forecasts show
that a chance of snow is possible in southeast IL Thur night only.
Otherwise, dry weather can be expected from Fri into Sunday. Then
Sunday night and Monday, models show a clipper system moving across
the northern third of the state. This will bring another shot of
pcpn to the northern/northeaster/and eastern parts of the CWA. P-
type will likely be snow, but with temps being above freezing during
the daytime periods, rain, or a mix of rain and snow is not out of
the question.
Temps will remain cold through Fri night given the continued Arctic
air over the area through tomorrow and then the clouds and pcpn
expected tomorrow night through Wed, and then again being north of
the Thur night/Fri weather system. Over the weekend the pattern will
become somewhat zonal and this should allow temps to warm back up to
normal or just above normal for Sun and Mon.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1139 PM CST MON JAN 18 2016
The band of low VFR clouds that was in western Illinois earlier
this evening has drifted eastward, extending from PIA to Lincoln
to DEC at 05z. At the same time, they have lowered slightly to
just into MVFR levels at 2700-2900 FT. In the last couple of
hours, satellite images has showed the band narrowing. The high
res models continue to show the MVFR clouds dissipating in the
next few hours. The subsidence inversion under the ridge axis
could counter some of that clearing, so will carry the MVFR clouds
for at least the next 3-4 hours of the TAF period, and update as
necessary.
Isentropic lift and warm advection ahead of the next system will
trigger mid and high clouds to begin overspreading our western
counties by early afternoon. Time height analysis in the NAM and
GFS point toward a period of stronger lift will begin by 01z near
SPI and expand eastward during the evening, reaching CMI and DEC
by 04z. The deeper moisture coincident with stronger omega will be
mainly closer to SPI and DEC, so have dropped them to IFR vis
during snowfall tomorrow evening. Snow could accumulate quickly,
based on moisture content of 3 g/kg mixing ratios, and moderately
strong isentropic lift on the 290K surface. Travel surface could
quickly become slippery Tuesday evening for all terminal sites.
Winds will generally be light and variable under the surface ridge
axis the rest of tonight, and even into tomorrow morning. Wind
directions will become southeast Tuesday afternoon as the surface
winds respond to the approaching cyclone.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
347 AM CST TUE JAN 19 2016
.SHORT TERM...(Today and Tonight)
Issued at 346 AM CST TUE JAN 19 2016
An upper level trough extended from the northern plains, south-
southwest across the central high plains into northeast NM early
this morning. The upper level trough will amplify slightly as it
moves east across the central and southern plains. Light
reflectivity returns on radar during the morning hours across the
northern and western CWA have not resulted in any light snow at this
time but through the morning hours the mid and low-levels of the
atmosphere should begin to saturate for light snow to develop along
the NE border with possible flurries farther south after 12Z. The
stronger ascent and mid level frontogenesis will not develop across
the eastern half of the CWA until the afternoon hours, then the snow
tempo should pick up enough for 1 to 2 inches of snow, generally
along and east of a Marysville to Burlington line. West of this line
expect only a dusting of snow in our southwest counties with half an
inch to 1 inch across north central KS.
vertical cross sections, perpendicular to the H5 thermal axis from
several model runs, show a stronger band of frontogenesis at 700mb
and some CSI across east central KS late this afternoon. Early in
the afternoon weak isentropic lift may saturate the low-levels
enough for patchy freezing drizzle to develop, before the stronger
lift shifts eastward for steadier light snow to develop. The 00Z NAM
forecast soundings never show much saturation within the dendritic
growth zone across the southwest counties, thus accumulations of
snow may only be dusting due to flurries but there may be a period
of freezing drizzle this afternoon across the southwest and southern
counties of the CWA. Any ice accumulations due to freezing drizzle
will remain light, less than one hundredths of an inch but could
produce a light glaze on area roadways.
The latest WRF runs (ARW and NMM) forecast more moderate snow bands
developing along the southeast counties of the CWA during the late
afternoon hours, where 1 to 2 inches of snowfall may occur. Even the
NAM models shows a more intense PV anomaly moving east across
southeast and east central KS, which could provide more lift in the
mid and upper levels of the atmosphere across the southeast counties
of the CWA. The next shift may have to adjust snow accumulations
slightly if the WRF solutions verify.
I will continue with the winter weather advisory for the eastern
half of the CWA. I added Marshall county into the advisory since
they could see over an inch of snowfall.
The clouds cover and light snowfall this afternoon should keep high
temperatures in mid to upper 20s.
The upper trough will shift east into MO after 00Z and the snow
should end across east central and northeast KS during the the early
evening hours. There may be a brief period of patchy freezing
drizzle across east central KS this evening before isentropic down
glide dries out the the low-levels of the atmosphere. Late Tonight
skies may begin to clear. In areas with snow cover and clear skies,
temperatures may drop into the upper single digits. If the clouds
hold through the night, then lows will only did down into the mid
teens.
.LONG TERM...(Wednesday through Monday)
Issued at 346 AM CST TUE JAN 19 2016
The most interesting time frame in the mid-term range forecast
remains from late Wednesday night through the day on Thursday. The
synoptic setup will be that a lead minor shortwave will act as a
source of lift and begin to develop areas of light snow late
Wednesday into Thursday early morning. After midnight into the
daybreak time frame, the main trough will pull out of the Central
Rockies and deepen into a closed upper low allowing for increased
ascent and further saturation of the underlying airmass. GFS
Ensembles are not yet in huge agreement on the precip amount, but do
at least tend to focus generally over the same region as the SREF
probabilities. Therefore, have increased POPs mainly southwest of a
line from Marysville through Topeka into Ottawa areas. Not
expecting huge snow accumulations, but it does appear more likely
that a good measurable snow will occur during the morning into the
afternoon on Thursday. While the GFS is the deeper and therefore
stronger of the solutions, the ECMWF and NAM solutions do agree
well overall with timing and location of precip amounts.
Additionally, all solutions keep a colder airmass in place with 540
thickness line off over southern KS. This all leads to increasing
confidence in the idea that snow will be the dominate precipitation
type over East Central Kansas into northeastern KS. This system
will move out of the area with the passage of the upper trough early
Friday and as it continues to deepen a strong ridge will build over
the Central and Northern Plains on Friday into the weekend. For the
rest of the period a fairly zonal pattern eventually takes shape
with temperatures holding near normal for this time of year with
only a very small chance of snow reaching the Nebraska/Kansas border
by Monday morning. Chances still too small at this point to enter
as slight POPs, so have not included any snow mention this forecast
period as this is the point where guidance begins to diverge from
one solution to the next by a fairly wide amount.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1134 PM CST MON JAN 18 2016
VFR conditions expected to become mvfr cigs in 09Z-12Z time
period. SN to develop in the 16Z-19Z time period with mvfr vsbys
transitioning to ifr cigs and vsbys by 19Z. VSBYS are expected to
improve to vfr after 00Z in MHK and around 03Z at TOP and FOE.
Latest soundings from RAP and NAM show precip type to be all snow.
Winds southeast to east around 10 kts, becoming northeast under 10
kts after 00Z.
&&
.TOP Watches/Warnings/Advisories...
Winter Weather Advisory from 9 AM this morning to 9 PM CST this
evening for KSZ023-024-026-038>040-054>056-058-059.
Winter Weather Advisory until 9 PM CST this evening for
KSZ010>012.
&&
$$
SHORT TERM...Gargan
LONG TERM...Drake
AVIATION...53
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1134 PM CST MON JAN 18 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Tuesday)
Issued at 311 PM CST MON JAN 18 2016
The main focus for the short-term is on the potential for snow
and freezing drizzle across the outlook area Tuesday and Tuesday
night.
Surface high pressure was centered over Missouri today, resulting in
southerly winds and gradual scattering of low/mid clouds which
helped to boost afternoon temperatures into the 20s to around 30
degrees for much of the CWA. The only exception was across Brown Co
where the deeper snowpack kept temperatures in the upper teens/near
20 degrees. Water vapor imagery showed a few embedded waves within
the mid-level flow across Montana and Wyoming this afternoon. Models
show these waves deepening as they track southeastward into the
central U.S. on Tuesday, exiting the area Tuesday night. Have kept a
dry forecast for tonight, but the increasing low/mid clouds along
with light southeasterly winds will limit radiational cooling
tonight, keeping low temperatures in the teens/low 20s. In fact,
these low temperatures will likely occur this evening with
temperatures gradually rising during the overnight hours, so have
gone with a non-diurnal temperature trend for tonight. Models show
the moisture and lift initially skimming across/near the
Kansas/Nebraska border Tuesday morning. However, model soundings
show shallow moisture with lift in the low-levels across much of the
CWA by mid to late morning. Soundings struggle to show deep enough
saturation extending into the dendritic growth zone during the
morning hours for much of the southern half of the CWA (but
especially across east central Kansas), so there is an increasing
concern for freezing drizzle generally along and south of I-70 and
more-so along and south of I-35. Near the I-70 corridor, model
soundings start showing some saturation in the dendritic growth zone
during the afternoon hours with a diminishing dry layer and cool
enough temperatures to likely support a transition over to snow by
mid to late afternoon. However, soundings struggle to bring
saturation into the dendritic zone for locations generally along and
south of I-35, so precipitation may predominantly be in the form of
freezing drizzle throughout the day. Temperatures should be cool
enough by Tuesday evening to have any lingering precipitation across
far northeast and far east central Kansas in the form of snow, with
the system exiting the area by mid to late evening.
There are some model discrepancies with regards to QPF amounts, with
the NAM showing the least amount. These discrepancies result in some
uncertainties with the exact snow and ice accumulations. The best
QPF will be focused across far northeast Kansas and this
precipitation should remain in the form of snow, resulting in 1 to 3
inches of snow accumulation. Expect this snow accumulation to be
primarily from mid morning through the afternoon hours. The lightest
snow accumulations should generally be along and west of a line from
Washington to Manhattan to Garnett with anywhere from a dusting to
upwards of around 1 inch. As for ice accumulations, cannot rule out
a light glaze of ice as far north as around the I-70 corridor
(during the morning hours), with a few hundredths of an inch of ice
accumulation possible along and south of I-35 (with these
accumulations occurring through the afternoon hours). As a result,
some snow-packed roads will be possible across northeast and
portions of east central Kansas, with slick road conditions from
light ice accumulations possible across east central Kansas. With
these accumulation amounts and impacts in mind, have issued a Winter
Weather Advisory for portions of northeast and east central Kansas.
Temperatures will remain cool on Tuesday with highs only in the 20s
to around 30 with lows Tuesday night dropping into the teens/around
20 degrees.
.LONG TERM...(Tuesday Night through Monday)
Issued at 311 PM CST MON JAN 18 2016
Still considerable differences in how models handle incoming
shortwave trofs for late Wednesday into Thursday. NAM brings a
few inches of snow to the western counties with the leading wave
before sunrise, while the GFS develops light accumulations over
the east and takes better piece of energy off to the south. EC
brings leading system out stronger and faster from the Rockies
before dropping the trof across central KS, also producing some
low end snow accumulations out west, with northerly shortwave wave
possibly extending some light snow into Thursday evening. NAM
soundings suggest snow growth zone could remain dry in the western
counties and bring freezing drizzle as opposed to snow. Too much
variability for much confidence in details. Will carry slight
chance to chance for precip, with mix possible in the western
counties.
Highs Wednesday slightly above freezing drop to freezing or below
for highs on Thursday, while upper 20s to low 30s come in behind
the system for Friday. Weekend brings a warming trend back toward
the 40s before next potential system may bring in cooler air for
Monday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1134 PM CST MON JAN 18 2016
VFR conditions expected to become mvfr cigs in 09Z-12Z time
period. SN to develop in the 16Z-19Z time period with mvfr vsbys
transitioning to ifr cigs and vsbys by 19Z. VSBYS are expected to
improve to vfr after 00Z in MHK and around 03Z at TOP and FOE.
Latest soundings from RAP and NAM show precip type to be all snow.
Winds southeast to east around 10 kts, becoming northeast under 10
kts after 00Z.
&&
.TOP Watches/Warnings/Advisories...
Winter Weather Advisory from 9 AM Tuesday to midnight CST
Tuesday night for KSZ023-024-026-038>040-054>056-058-059.
Winter Weather Advisory from 6 AM Tuesday to midnight CST
Tuesday night for KSZ011-012.
&&
$$
SHORT TERM...Hennecke
LONG TERM...67
AVIATION...53
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
357 AM EST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EST MON JAN 18 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL LOW FROM THE
ERN LAKES INTO NRN NEW ENGLAND WITH A SHORTWAVE TROUGH EXTENDING NW
TO NEAR LAKE SUPERIOR. AT THE SFC...A LAKES AGGREGATE TROUGH EXTENDED
FROM LAKE HURON INTO SRN LAKE SUPERIOR. MULTIPLE WIND PARALLEL LES
BANDS WITH NW ARCTIC FLOW CONTINUED. 850 MB TEMPS AROUND -23C
PROVIDED PLENTIFUL INSTABILITY WITH LAKE INDUCED CAPES INTO THE
500-750 J/KG. THE MID LEVEL SHRTWV AND ASSOCIATED 700-300 MB QVECTOR
CONV HAS ALSO HELPED BOOST INVERSION/EQUILIBRIUM HEIGHTS THIS
AFTERNOON. VIS LOOP...SFC OBS AND WEB CAMS SUGGEST THE HEAVIER LES
WAS OVER THE ERN CWA...IN CLOSER PROXIMITY TO THE SHRTWV AND
DOWNSTREAM FROM THE LONGEST FETCH.
TONIGHT...THE HIGH RES MODELS SUGGEST THAT LOW LEVEL WINDS WILL VEER
SLIGHTLY IN THE WAKE OF THE SHRTWV...HELPING TO PUSH THE MORE
PROMINENT LES BANDS INTO CNTRL AND WRN ALGER COUNTY. WITH ADDITIONAL
SNOWFALL AMOUNTS IN THE 3 TO 7 INCH RANGE EXPECTED...THE LES WARNING
WAS EXTENDED (TIL 12Z) FOR ALGER AND NRN SCHOOLCRAFT COUNTIES WITH
AN THE ADVY INTO SRN SCHOOLCRAFT ALSO EXTENDED TIL 06Z.
OVER THE WEST...INVERSION HEIGHTS DROP OFF TO AROUND 4K FT THIS
EVENING WHICH SHOULD LIMIT LES INTENSITY WITH ADDITIONAL SNOWFALL
AMOUNTS TO ADVY AMOUNTS IN THE 2 TO 5 INCH RANGE OR LESS. THE
STRONGER LOW LEVEL CONV FROM ONTONAGON EASTWARD SHOULD ALSO SAG TO
THE SOUTH THIS EVENING.
TUE...LES SHOULD CONTINUE TO DIMINISH WITH INVERSION HEIGHTS FALLING
TO 3K-4K FT AND WINDS BACKING ACYC WRLY AS A SFC RIDGE BUILDS FROM
THE UPPER MS VALLEY INTO THE WRN LAKES. TEMPS WILL ALSO MODERATE
WITH HIGHS FROM THE LOWER TEENS WEST TO AROUND 20 EAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EST TUE JAN 19 2016
...SMALL CHANCES OF SNOW THROUGH THE WEEK WITH A WARMING TREND BY
THE WEEKEND...
UPPER LOW AND CORE OF THE COLD WILL BE OVER FAR EASTERN CANADA
AROUND LABRADOR ON WED WHILE WNW FLOW ALOFT BRINGS WARMER AIR ALOFT
FM WESTERN CANADA TO GREAT LAKES. NW FLOW PERSISTS THROUGH LATE WEEK
BUT SYSTEMS WITHIN THIS FLOW LOOK TO REMAIN WEAK. LATER THU INTO
FRI...A MUCH STRONGER TROUGH ALOFT TAKES SHAPE OVER SOUTHERN PLAINS
AND THOUGH THIS SYSTEM WILL STAY WELL TO SOUTH OF GREAT LAKES...IT
COULD BECOME SIGNIFICANT WINTER STORM FOR THE MID ATLANTIC THIS
WEEKEND. AS THAT IS OCCURRING THERE...RIDGING WILL BE BUILDING FM
THE WESTERN CONUS INTO THE MID CONUS AND WESTERN GREAT LAKES. THERMAL
RIDGE POKES ACROSS UPPER LAKES ON SAT INTO SUN WHEN TEMPS COULD REACH
NEAR 30 DEGREES...THEN TURNS COOLER BY MON IN WAKE OF A COLD FRONT.
OVERALL NOT A LOT OF OPPORTUNTIES FOR MUCH SNOW IN THE EXPECTED
PATTERN...EITHER WIDESPREAD SYSTEM TYPE OR LAKE EFFECT...BUT THERE
WILL BE SOME CHANCES FOR LIGHT SNOW. FIRST ON WED...SHORTWAVE TROUGH
CURRENTLY CROSSING NORTHERN PLAINS WILL BE BRINGING LIGHT SNOW FROM
ILL TO LOWER MI. OVER UPR MICHIGAN...DRY AIR BLO 10KFT WILL PROHIBIT
MUCH SNOWFALL TO START BUT THEN MOISTURE INCREASES THROUGH THE DAY.
LIFT REMAINS WEAK THOUGH SO STILL NOT LOOKING AT EVEN AN INCH OF
SNOW WITH THIS SYSTEM ANYWHERE IN THE CWA. ANOTHER WEAKER SYSTEM
CROSSES NW ONTARIO AND THE UPPER GREAT LAKES WED NIGHT INTO THU.
BEST FORCING STAYS OVER LK SUPERIOR AND INTO NW ONTARIO...BUT WEAK
SFC TROUGH TIED TO THE SHORTWAVE COULD BRING LIGHT SNOW TO KEWEENAW.
AS TROUGH MOVES THROUGH...MAY SEE LIGHT LAKE EFFECT SNOW SHOWERS THU
NIGHT INTO FRI WITH H85 TEMPS DOWN TO AROUND -13C AND MAYBE AS LOW AS
-15C WHILE ANOTHER WEAKER SHORTWAVE CROSSES UPPER GREAT LAKES. LOW-
LEVEL WINDS START OUT NW IN WAKE OF TROUGH BUT BECOME NORTHERLY BY
FRI...SO GOOD PART OF LK SUPERIOR SHORE COULD SEE LAKE EFFECT THU
NIGHT INTO FRI. GFS SOUNDINGS SHOW ALL THE MOIST LAYER WITHIN THE
DGZ...SO FLUFF FACTOR COULD BE HIGHER. BUT...MARGINALLY COLD
TEMPS...INVERSIONS LESS THAN 5KFT AND LACK OF STRONG LOW-LEVEL
CONVERGENCE SHOULD LIMIT INTENSITY OF LAKE EFFECT. INCREASED POPS
OVER CONSENSUS AS THINK THERE SHOULD BE SOME SNOW AROUND FOR THE
FAVORED LAKE EFFECT AREAS.
HIGH PRESSURE RIDGE CROSSING FRI NIGHT INTO SAT SWITCHES WINDS TO SW
AND BRINGS WARMER AIRMASS OVER THE UPPER GREAT LAKES...SO LAKE
EFFECT WILL END. H85 TEMPS AROUND -10C FRI NIGHT WARM TO -6C BY SAT
MORNING AND -2C BY SAT EVENING. SKIES ON SAT SHOULD START OUT MOSTLY
SUNNY THEN THERE WILL BE THICKENING MID-HIGH CLOUDS IN THE AFTN
AHEAD OF ANOTHER SHORTWAVE TROUGH AND WEAK WAVE OF LOW PRES CROSSING
NORTHERN PLAINS INTO NW ONTARIO. SOUNDINGS INDICATE SHALLOW MIXING
HEIGHTS OF 950MB-925MB ON SAT BUT WITH GOOD DEAL OF SUNSHINE...COULD
BE HIGHER. SHALLOW MIXING SUPPORTS HIGHS INTO THE UPPER 20S.
SLIGHTLY DEEPER MIXING TO 900MB WOULD YIELD HIGHS INTO THE MID-UPR
30S. DEEPER MIXING COULD TAP INTO PORTION OF 30-40 KT WINDS ALOFT.
ATTM LOOKS LIKE MAX CORE OF WINDS WILL STAY ABOVE INVERION...BUT
STILL COULD BE BREEZY BY AFTN DUE TO THE TIGHTER PRESSURE GRADIENT
BTWN THE EXITING RIDGE AND SFC LOW/COLD FRONT SCNTRL CANADA TO
NORTHERN PLAINS. NUDGED MAX TEMPS UPWARD OVER CONSENSUS BUT ONLY
INTO THE LOW 30S AT THE WARMEST. AS THAT SYSTEM MOVES INTO NW
ONTARIO MAY SEE LIGHT SNOW OR FLURRIES OVER UPR MICHIGAN. MODELS NOT
VERY CONSISTENT ON THAT IDEA...BUT WORTHY OF LOW CHANCES ESPECIALLY
NORTH CWA AND OUT ACROSS LK SUPERIOR.
MAY SEE ANOTHER ROUND OF LIGHT LAKE EFFECT SNOW SUN NIGHT INTO MON
AND THERE ARE SOME INDICATIONS OF ANOTHER SHORTWAVE MOVING THROUGH
WITH A WAVE OF LIGHT SNOW OVER UPPER GREAT LAKES. PLENTY OF TIME FOR
DETAILS TO CHANGE...BUT AT THIS TIME NOT LOOKING LIKE MUCH SNOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 104 AM EST TUE JAN 19 2016
AT KIWD...EXPECT IFR/MVFR VSBY DURING THE HEAVIER SNOW BANDS AT IWD
EARLY IN THIS FORECAST...BUT THEN WINDS BACKING LATE TONIGHT WILL
ALLOW FOR IMPROVEMENT TO PREVAILING MVFR CONDITIONS IN LIGHTER LAKE
EFFECT SHOWERS. EXPECT A RETURN TO VFR CONDITIONS TUE AFTERNOON AS
WINDS BACK TO THE SW.
AT KCMX...CONTINUED LAKE EFFECT SNOW SHOWERS WILL STILL RESULT IN
PREVAILING LOW MVFR/IFR CONDITIONS THROUGH TUE AFTERNOON BEFORE MVFR
CONDITIONS RETURN BY TUE NIGHT.
AT KSAW...EXPECT MVFR EARLY IN THE PERIOD AS SOME LIGHT LAKE EFFECT
SNOW BRUSHES THE AREA. BACKING WINDS LATE TONIGHT WILL ALLOW
IMPROVEMENT AGAIN TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST MON JAN 18 2016
EXPECT WINDS TO DIMINISH LATER THIS EVENING TO 20-25 KTS...HIGHEST
OVER ERN LAKE SUPERIOR. IN ADDITION...HEAVY FREEZING SPRAY IS
EXPECTED WILL ALSO END EARLY THIS EVENING. WINDS ARE EXPECTED TO
SLOWLY DIMINISH TOWARDS THE MIDDLE OF THE WEEK...AS HIGH PRESSURE
MOVES OVER THE UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
110 AM EST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EST MON JAN 18 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL LOW FROM THE
ERN LAKES INTO NRN NEW ENGLAND WITH A SHORTWAVE TROUGH EXTENDING NW
TO NEAR LAKE SUPERIOR. AT THE SFC...A LAKES AGGREGATE TROUGH EXTENDED
FROM LAKE HURON INTO SRN LAKE SUPERIOR. MULTIPLE WIND PARALLEL LES
BANDS WITH NW ARCTIC FLOW CONTINUED. 850 MB TEMPS AROUND -23C
PROVIDED PLENTIFUL INSTABILITY WITH LAKE INDUCED CAPES INTO THE
500-750 J/KG. THE MID LEVEL SHRTWV AND ASSOCIATED 700-300 MB QVECTOR
CONV HAS ALSO HELPED BOOST INVERSION/EQUILIBRIUM HEIGHTS THIS
AFTERNOON. VIS LOOP...SFC OBS AND WEB CAMS SUGGEST THE HEAVIER LES
WAS OVER THE ERN CWA...IN CLOSER PROXIMITY TO THE SHRTWV AND
DOWNSTREAM FROM THE LONGEST FETCH.
TONIGHT...THE HIGH RES MODELS SUGGEST THAT LOW LEVEL WINDS WILL VEER
SLIGHTLY IN THE WAKE OF THE SHRTWV...HELPING TO PUSH THE MORE
PROMINENT LES BANDS INTO CNTRL AND WRN ALGER COUNTY. WITH ADDITIONAL
SNOWFALL AMOUNTS IN THE 3 TO 7 INCH RANGE EXPECTED...THE LES WARNING
WAS EXTENDED (TIL 12Z) FOR ALGER AND NRN SCHOOLCRAFT COUNTIES WITH
AN THE ADVY INTO SRN SCHOOLCRAFT ALSO EXTENDED TIL 06Z.
OVER THE WEST...INVERSION HEIGHTS DROP OFF TO AROUND 4K FT THIS
EVENING WHICH SHOULD LIMIT LES INTENSITY WITH ADDITIONAL SNOWFALL
AMOUNTS TO ADVY AMOUNTS IN THE 2 TO 5 INCH RANGE OR LESS. THE
STRONGER LOW LEVEL CONV FROM ONTONAGON EASTWARD SHOULD ALSO SAG TO
THE SOUTH THIS EVENING.
TUE...LES SHOULD CONTINUE TO DIMINISH WITH INVERSION HEIGHTS FALLING
TO 3K-4K FT AND WINDS BACKING ACYC WRLY AS A SFC RIDGE BUILDS FROM
THE UPPER MS VALLEY INTO THE WRN LAKES. TEMPS WILL ALSO MODERATE
WITH HIGHS FROM THE LOWER TEENS WEST TO AROUND 20 EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 324 PM EST MON JAN 18 2016
THE 500MB RIDGE OVERHEAD ON TUESDAY WILL SLOWLY EXIT E TUESDAY NIGHT
AND WEDNESDAY IN RESPONSE TO THE ELONGATED TROUGH EXTENDING FROM S
CENTRAL CANADA THROUGH W MN AND IA AT 00Z WEDNESDAY. THIS TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES DURING THE DAY
WEDNESDAY...AND TO THE LOWER GREAT LAKES 00-06Z THURSDAY. THIS WILL
BY WHILE THE LARGE SFC HIGH STRETCHING FROM THE UPPER GREAT LAKES TO
THE TIP OF FL AT 00Z WEDNESDAY SLOWLY BECOMES SUPRESSED TO THE SE. LOOKING
SPECIFICALLY AT THE LINGERING LAKE INDUCED TROUGH OVER LAKE
SUPERIOR...IT WILL SLOWLY DEEPEN OVERNIGHT AND INTO THURSDAY. EXPECT
LINGERING LES BANDS TO SHIFT ACROSS THE TIP OF THE KEWEENAW
PENINSULA AND FAR N LUCE COUNTY...AND EVENTUALLY OFFSHORE AS
SFC WINDS SHIFT TO A MORE S-SW DIRECTION.
A SHORTWAVE PUSHING ACROSS THE PACIFIC NORTHWEST WEDNESDAY MORNING
WILL LIVE ACROSS THE PLAINS STATES WEDNESDAY NIGHT WHILE A N WAVE
MOVES ACROSS LAKE SUPERIOR/UPPER MI. BY 00Z THURSDAY THE SFC MAP
WILL SHOW THE NEXT LOW OVER FAR E CO WILL HAVE AN INVERTED TROUGH UP
THROUGH SW MN AND W ONTARIO. THE N LOW WILL BE FAIRLY
PROGRESSIVE...MOVING OVER LAKE SUPERIOR BY 12Z THURSDAY AND EXITING
ACROSS LOWER MI THURSDAY NIGHT...MERGING WITH THE STRONGER LOW
ACROSS TN. THIS WILL BRING THE BEST CHANCE OF WIDESPREAD SNOW FOR
THIS LONG TERM PERIOD...WILL LIKELY BE LATE THURSDAY INTO EARLY
FRIDAY. AT THIS POINT THE GFS IS THE MOST ROBUST WITH THE SNOW WITH
1-4IN CWA WIDE. THE ON THE POSITIVE SIDE THE DGZ IS WITHIN THE
MOISTURE LAYER...BUT INVERSION HEIGHTS LOOK TO FALL PRETTY QUICKLY
OVERNIGHT THURSDAY NIGHT INTO FRIDAY MORNING. FAVORABLE UPSLOPE
CONDITIONS FOR LES DO NOT SEEM TO RETURN TO THE CWA UNTIL LATE
THURSDAY AFTERNOON IN THE FORM OF NW WIND BEHIND THE EXITING SFC
LOW. THEY WILL NOT BE ALL THAT STEADY FOR SIGNIFICANT DOMINANT BANDS
TO DEVELOP AS WINDS SHIFT OUT OF THE N-NNE BY DAYBREAK FRIDAY. A
GENERAL 500MB TROUGH WILL BE SETUP ACROSS THE UPPER GREAT LAKES
THROUGH THE GULF OF MEXICO W THURSDAY-FRIDAY...KEEPING COOLER AIR
OVER THE AREA. 850MB TEMPS WILL REMAIN -7 TO -14C.
LOOK FOR A SIGNIFICANT RIDGE OF HIGH PRESSURE AT 500MB FRIDAY NIGHT
TO EXTEND FROM THE INTERIOR SW UP THROUGH THE PLAINS TO PUSH INTO
THE UPPER GREAT LAKES AS THE S TROUGH DEEPENS TO A LOW AND BEGINS TO
EXIT OFF THE MID ATLANTIC SEABOARD. THIS 500MB LOW WILL PUSH N JUST
OFF THE NEW ENGLAND COAST BY SUNDAY MORNING. WAA WILL RESULT...AS
850MB TEMPS RISE TO -5 TO -10C BY 06Z SATURDAY /WARMEST OFF THE
ECMWF/...AND -1 TO -5C BY 00Z SUNDAY ON SW 850MB WINDS NEARING 35KTS.
THERE ARE SOME DIFFERENCES IN THE HANDLING OF THE 500MB LOW OVER N
CANADA FOR THE END OF THE UPCOMING WEEKEND. WHILE BOTH THE GFS AND
ECMWF SHOW A DEEP TROUGH SWINGING ACROSS MUCH OF THE NATION...THE
GFS IS FARTHER S WITH THIS FEATURE. EXPECT SOME STEADY SNOW TO SLIDE
IN FROM THE S SUNDAY EVENING INTO EARLY MONDAY...BUT TIMING AND
INTENSITY COULD CHANGE SIGNIFICANTLY BETWEEN NOW AND THEN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 104 AM EST TUE JAN 19 2016
AT KIWD...EXPECT IFR/MVFR VSBY DURING THE HEAVIER SNOW BANDS AT IWD
EARLY IN THIS FORECAST...BUT THEN WINDS BACKING LATE TONIGHT WILL
ALLOW FOR IMPROVEMENT TO PREVAILING MVFR CONDITIONS IN LIGHTER LAKE
EFFECT SHOWERS. EXPECT A RETURN TO VFR CONDITIONS TUE AFTERNOON AS
WINDS BACK TO THE SW.
AT KCMX...CONTINUED LAKE EFFECT SNOW SHOWERS WILL STILL RESULT IN
PREVAILING LOW MVFR/IFR CONDITIONS THROUGH TUE AFTERNOON BEFORE MVFR
CONDITIONS RETURN BY TUE NIGHT.
AT KSAW...EXPECT MVFR EARLY IN THE PERIOD AS SOME LIGHT LAKE EFFECT
SNOW BRUSHES THE AREA. BACKING WINDS LATE TONIGHT WILL ALLOW
IMPROVEMENT AGAIN TO VFR. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST MON JAN 18 2016
EXPECT WINDS TO DIMINISH LATER THIS EVENING TO 20-25 KTS...HIGHEST
OVER ERN LAKE SUPERIOR. IN ADDITION...HEAVY FREEZING SPRAY IS
EXPECTED WILL ALSO END EARLY THIS EVENING. WINDS ARE EXPECTED TO
SLOWLY DIMINISH TOWARDS THE MIDDLE OF THE WEEK...AS HIGH PRESSURE
MOVES OVER THE UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ006-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR
MIZ001>003-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1200 AM EST TUE JAN 19 2016
.AVIATION...
THE LAKE EFFECT SNOW BAND HAS BECOME INCREASINGLY DISORGANIZED OVER
THE PAST HOUR. A RANGE OF CIG HEIGHTS NOW EXIST OVER SOUTHEASTERN
MICHIGAN WITH MVFR STRATOCUMULUS STILL IN PLACE UNDER LAKE EFFECT
PLUME...WITH LITTLE TO NO LOW LEVEL CLOUD IN PLACE OVER THE TRI
CITIES CURRENTLY. THE STEEP LAPSE RATE STRUCTURE AND DEEP MIXED
LAYER THAT HAS BEEN IN PLACE IS FORECASTED BREAK DOWN VERY RAPIDLY
OVER THE NEXT 2-4 HOURS AS WINDS VEER WEST TO NORTHWEST. VERY SHARP
SUBSIDENCE WILL THEN PUSH DOWN INTO SOUTHEASTERN MICHIGAN IN
RESPONSE TO THE SHARP MIDLEVEL TROUGH AXIS PUSHING THROUGH THE
TERMINALS. EXPECTING GENERAL VFR CONDITIONS TUESDAY MORNING GIVING
WAY TO DIURNAL MVFR STRATOCUMULUS DEVELOPMENT.
FOR DTW...MVFR CIGS TO HOLD THROUGH MUCH OF TONIGHT BEFORE
SCATTERING AROUND DAWN. STEEP LOW LEVEL LAPSE RATES AND DIURNAL
HEATING SHOULD LEAD TO MVFR CIGS AGAIN BY 17Z.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING AOB 5000 FT THROUGH LATE TONIGHT.
* HIGH FOR SNOW AS PRECIPITATION TYPE.
&&
.PREV DISCUSSION...ISSUED 938 PM EST MON JAN 18 2016
UPDATE...
ISSUED AN UPDATE TO EXTEND THE LIGHT SNOW LIKELY WORDING ACROSS
THE INTERSTATE 96 CORRIDOR WELL THROUGH MIDNIGHT. LATEST RADAR
IMAGERY SUPPORTS THE DEVELOPMENT OF NEAR STEADY STATE LIGHT SNOW
BANDING INTO SOUTHEASTERN MICHIGAN. THE RADAR IMAGERY DOES SHOW
SNOW PRODUCTION AS HIGH AS THE 4000-6000 FT AGL LAYER...WHICH
CORRESPONDS EXACTLY TO STEEP LAPSE RATE POCKET JUST BELOW
INVERSION IN THE 00Z KDTX RAOB. THEREFORE...NOT EXPECTING
NOCTURNAL COOLING PROCESSES TO HAVE MUCH OF AN IMPACT...AND
INSTEAD WILL RELY ON CHANGE IN WIND DIRECTION. THIS IS SET TO
OCCUR WITH 1000-850 MB MEAN WIND VEERING NORTHWESTERLY IN THE
06-09Z TIMEFRAME TIED TO SHARP CYCLONIC VORTICITY FEATURE DIGGING
THROUGH. SURFACE OBSERVING SITES HAVE NOT BEEN CATCHING BULK OF
THE BAND...BUT LIMITED SURFACE SPOTTER REPORTS SUGGEST QUICK
DUSTING TYPE ACCUMULATIONS WITH RATHER MINOR DROPS IN VISIBILITY.
RATHER...THERE HAVE BEEN REPORTS OF VERY SLIPPERY CONDITIONS ALONG
THE AXIS OF LIGHT SNOWFALL...LIKELY A CONSEQUENCE OF THE COLD
TEMPERATURES AND LACK OF IMPACT FROM SALT/TREATMENT. THERE IS LOW
CONFIDENCE IN WHAT SORT OF ACCUMULATIONS WILL BE
POSSIBLE...PERHAPS UP TO AN INCH IN SOME LOCATIONS.
PREV DISCUSSION...ISSUED 350 PM EST MON JAN 18 2016
DISCUSSION...
LAKE EFFECT SNOW SHOWERS WILL HOLD WITH SCATTERED TO NUMEROUS
COVERAGE AND LIGHT TO MODERATE INTENSITY FOR THE REST OF THE
AFTERNOON THROUGH MID EVENING. THE MOST RECENT RAP SOUNDINGS
INDICATE CONVECTIVE DEPTH SETTLING STEADILY BELOW 5000 FT BETWEEN
21Z AND 03Z BUT WITH NEARLY DRY ADIABATIC LAPSE RATE AND HIGH ICE
SUPERSATURATION WITHIN THE CLOUD LAYER FOR HEALTHY GROWTH OF
DENDRITES. THAT BEING SAID...SURFACE DEWPOINT AROUND -10F REPORTED
UPSTREAM OF LAKE MICHIGAN HAS TO BE CONSIDERED A LIMITING FACTOR FOR
LAKE INDUCED CONVECTIVE POTENTIAL THIS FAR EAST. ON THE POSITIVE
SIDE...MID TO LATE AFTERNOON SURFACE OBSERVATIONS ON THIS SIDE OF
THE LAKE CONTINUE TO ADVERTISE GUSTY WEST FLOW WITH A GREATER AMOUNT
OF CONVERGENCE DOWN WIND OF LAKE MICHIGAN THAN WOULD NORMALLY BE
EXPECTED IN WELL MIXED MID AFTERNOON CONDITIONS. THIS WILL KEEP
COVERAGE WITH BETTER INTENSITY FOCUSED GENERALLY ALONG AND SOUTH OF
THE I-96 TO I-94 CORRIDOR. FACTORING IN THE DRY NATURE OF THE ARCTIC
AIR AND STEADILY SHRINKING CONVECTIVE DEPTH...EXPECT ACCUMULATION
LIMITED TO LESS THAN AN INCH EVEN WITH NUMEROUS COVERAGE AND/OR A
STREAMER OF GREATER FOCUSED BANDING AT TIMES BEFORE DIMINISHING
TOWARD MIDNIGHT.
THE UPPER LEVEL TROUGH WILL SWING SOUTH OF LOWER MICHIGAN SHORTLY
AFTER MIDNIGHT AND WILL SHUT DOWN LAKE EFFECT PRODUCTION. STRONG
SUBSIDENCE TRAILING THE UPPER TROUGH AND PRECEDING THE RIDGE AXIS
WILL ALSO SUPPORT A CLEARING TREND MUCH LIKE WHAT OCCURRED EARLY
THIS MORNING. THIS WILL ALLOW ANOTHER ROUND OF SINGLE DIGIT MIN
TEMPS OUTSIDE OF METRO DETROIT AND MAINTAIN WIND CHILL NEAR 10
BELOW AT TIMES THROUGH TUESDAY MORNING. FORECAST CONCERNS WILL THEN
BE REDUCED TO CLOUD AND TEMPERATURE TRENDS DURING THE REST OF
TUESDAY AND TUESDAY NIGHT. BACKING LOW LEVEL FLOW WILL DIRECT
REMAINING LAKE EFFECT CLOUDS MAINLY INTO THE TRI CITIES BEFORE HIGH
PRESSURE BUILDS OVER THE REGION BY EVENING. LIGHTER WIND WILL MAKE
MAX TEMPS IN THE LOWER 20S EASIER TO TAKE COMPARED TO RECENT DAYS.
BENIGN CONDITIONS WILL CONTINUE THROUGH TUESDAY NIGHT AS HIGH CLOUDS
THICKEN AND LOWER IN ADVANCE OF THE NEXT LOW PRESSURE SYSTEM. THE
NEW MODEL PACKAGE IS IN GOOD AGREEMENT HOLDING OFF SNOW UNTIL
WEDNESDAY MORNING...MAINLY AFTER THE MORNING DRIVE...AND THEN
LEAVING UP TO AN INCH OF ACCUMULATION BEFORE ENDING BY MIDNIGHT
WEDNESDAY NIGHT. EXPECT THIS TO BE MOSTLY A MID LEVEL ISENTROPIC
LIFT DRIVEN EVENT AS MODEL DEPICTIONS OF THE 500 MB HEIGHT FIELD
SHOW CONSOLIDATION OF SHORT WAVES IN THE FLOW BUT WITH FRAGMENTED
DYNAMIC SUPPORT IN TERMS OF DCVA. THE LOW LEVEL FRONTAL ZONE IS ALSO
LOCATED WELL SOUTH INTO THE OHIO AND TENNESSEE VALLEYS JUDGING BY
1000-850 MB THICKNESS. THIS DOES NOT PREVENT ADEQUATE MOISTURE FROM
REACHING THIS FAR NORTH AS SPECIFIC HUMIDITY AVERAGES 1-2 G/KG UP TO
700 MB OVER LOWER MICHIGAN. IT DOES INDICATE THE SHALLOW AND STABLE
NATURE OF THE SYSTEM RELATIVE ISENTROPIC LIFT. AS MENTIONED IN THE
PREVIOUS DISCUSSION...MODEL SOUNDINGS DO INDICATE A DEEP ISOTHERMAL
PROFILE WITHIN THE DGZ BELOW 600 MB WHICH WILL GIVE A BOOST TO SNOW
RATIO AND POTENTIAL OVERACHIEVEMENT. THE COLLABORATED QPF ADJUSTMENTS
MADE IN THE PREVIOUS FORECAST CYCLE ARE THUS PRESERVED FOR THIS
PACKAGE.
EXTENDED THURSDAY THROUGH TUESDAY... AS WEDNESDAY`S WAVE OF LOW
PRESSURE EXITS THE REGION...A SLIGHT CHANCE OF SNOW SHOWERS WILL
REMAIN IN THE FORECAST THROUGH EARLY THURSDAY MORNING. BRIEF HIGH
PRESSURE BUILDS OVER THE AREA DURING THE DAY ON THURSDAY. THIS
HIGH PRESSURE IS EXPECTED TO PRODUCE A DECENT DRY DAY WITH MOSTLY
TO PARTLY CLOUDY SKIES OVER THE WHOLE OF SOUTHEAST MICHIGAN. AN
UPPER LEVEL TROUGH SWINGS ACROSS THE NORTHERN THUMB AREAS ON
FRIDAY...GENERATING ANOTHER WEAK SHOT AT SNOW SHOWERS. HIGH
PRESSURE IS ON TAP TO RETURN FOR THE WEEKEND. TEMPERATURE
CONTINUES TO WARM THROUGH THE PERIOD WITH HIGHS EDGING INTO THE
MID 30`S BY SUNDAY OVER SOUTHERN HALF OF THE CWA.
MARINE...
A SURFACE TROUGH SLOWLY DROPPING THROUGH LAKE HURON WILL MAINTAIN
STRONG WESTERLY WINDS THROUGH THE REMAINDER OF THE AFTERNOON AND
EVENING OVER SOUTHERN LAKE HURON...LAKE ST CLAIR...AND WESTERN LAKE
ERIE. WINDS WILL BE STRONGEST OVER THE SOUTHERN THIRD OF LAKE
HURON...WHERE GUSTS WILL PRIMARILY REMAIN AROUND 30 KNOTS...BUT A
FEW GUSTS TO GALE FORCE ARE POSSIBLE. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR THE NEARSHORE WATERS OF LAKE HURON FROM OUTER SAGINAW
BAY DOWN TO PORT HURON. THE REMAINDER OF THE NEARSHORE WATERS ARE
ICE COVERED AND THEREFORE REMAIN WITHOUT A HEADLINE. WINDS WILL
DECREASE EARLY TONIGHT AS THE SURFACE TROUGH DROPS SOUTHWARD.
IN ADDITION...THE STRONG WINDS AND ARCTIC AIRMASS IN PLACE WILL
CREATE FAVORABLE CONDITIONS FOR FREEZING SPRAY TO DEVELOP OVER LAKE
HURON THROUGH TUESDAY...ESPECIALLY ACROSS THE OPEN WATERS. INTENSITY
LOOKS TO ONLY REMAIN MODERATE HOWEVER.
WINDS WILL REMAIN A LITTLE GUSTY OUT OF THE NORTHWEST ACROSS LAKE
HURON TUESDAY BEFORE HIGH PRESSURE BUILDING INTO THE CENTRAL GREAT
LAKES AND OHIO VALLEY BRINGS LIGHTER WIND CONDITIONS FROM LATE
TUESDAY INTO WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....CB
UPDATE.......CB
DISCUSSION...BT/DE
MARINE.......HLO
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1131 PM EST MON JAN 18 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EST MON JAN 18 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL LOW FROM THE
ERN LAKES INTO NRN NEW ENGLAND WITH A SHORTWAVE TROUGH EXTENDING NW
TO NEAR LAKE SUPERIOR. AT THE SFC...A LAKES AGGREGATE TROUGH EXTENDED
FROM LAKE HURON INTO SRN LAKE SUPERIOR. MULTIPLE WIND PARALLEL LES
BANDS WITH NW ARCTIC FLOW CONTINUED. 850 MB TEMPS AROUND -23C
PROVIDED PLENTIFUL INSTABILITY WITH LAKE INDUCED CAPES INTO THE
500-750 J/KG. THE MID LEVEL SHRTWV AND ASSOCIATED 700-300 MB QVECTOR
CONV HAS ALSO HELPED BOOST INVERSION/EQUILIBRIUM HEIGHTS THIS
AFTERNOON. VIS LOOP...SFC OBS AND WEB CAMS SUGGEST THE HEAVIER LES
WAS OVER THE ERN CWA...IN CLOSER PROXIMITY TO THE SHRTWV AND
DOWNSTREAM FROM THE LONGEST FETCH.
TONIGHT...THE HIGH RES MODELS SUGGEST THAT LOW LEVEL WINDS WILL VEER
SLIGHTLY IN THE WAKE OF THE SHRTWV...HELPING TO PUSH THE MORE
PROMINENT LES BANDS INTO CNTRL AND WRN ALGER COUNTY. WITH ADDITIONAL
SNOWFALL AMOUNTS IN THE 3 TO 7 INCH RANGE EXPECTED...THE LES WARNING
WAS EXTENDED (TIL 12Z) FOR ALGER AND NRN SCHOOLCRAFT COUNTIES WITH
AN THE ADVY INTO SRN SCHOOLCRAFT ALSO EXTENDED TIL 06Z.
OVER THE WEST...INVERSION HEIGHTS DROP OFF TO AROUND 4K FT THIS
EVENING WHICH SHOULD LIMIT LES INTENSITY WITH ADDITIONAL SNOWFALL
AMOUNTS TO ADVY AMOUNTS IN THE 2 TO 5 INCH RANGE OR LESS. THE
STRONGER LOW LEVEL CONV FROM ONTONAGON EASTWARD SHOULD ALSO SAG TO
THE SOUTH THIS EVENING.
TUE...LES SHOULD CONTINUE TO DIMINISH WITH INVERSION HEIGHTS FALLING
TO 3K-4K FT AND WINDS BACKING ACYC WRLY AS A SFC RIDGE BUILDS FROM
THE UPPER MS VALLEY INTO THE WRN LAKES. TEMPS WILL ALSO MODERATE
WITH HIGHS FROM THE LOWER TEENS WEST TO AROUND 20 EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 324 PM EST MON JAN 18 2016
THE 500MB RIDGE OVERHEAD ON TUESDAY WILL SLOWLY EXIT E TUESDAY NIGHT
AND WEDNESDAY IN RESPONSE TO THE ELONGATED TROUGH EXTENDING FROM S
CENTRAL CANADA THROUGH W MN AND IA AT 00Z WEDNESDAY. THIS TROUGH
WILL SLIDE ACROSS THE UPPER GREAT LAKES DURING THE DAY
WEDNESDAY...AND TO THE LOWER GREAT LAKES 00-06Z THURSDAY. THIS WILL
BY WHILE THE LARGE SFC HIGH STRETCHING FROM THE UPPER GREAT LAKES TO
THE TIP OF FL AT 00Z WEDNESDAY SLOWLY BECOMES SUPRESSED TO THE SE. LOOKING
SPECIFICALLY AT THE LINGERING LAKE INDUCED TROUGH OVER LAKE
SUPERIOR...IT WILL SLOWLY DEEPEN OVERNIGHT AND INTO THURSDAY. EXPECT
LINGERING LES BANDS TO SHIFT ACROSS THE TIP OF THE KEWEENAW
PENINSULA AND FAR N LUCE COUNTY...AND EVENTUALLY OFFSHORE AS
SFC WINDS SHIFT TO A MORE S-SW DIRECTION.
A SHORTWAVE PUSHING ACROSS THE PACIFIC NORTHWEST WEDNESDAY MORNING
WILL LIVE ACROSS THE PLAINS STATES WEDNESDAY NIGHT WHILE A N WAVE
MOVES ACROSS LAKE SUPERIOR/UPPER MI. BY 00Z THURSDAY THE SFC MAP
WILL SHOW THE NEXT LOW OVER FAR E CO WILL HAVE AN INVERTED TROUGH UP
THROUGH SW MN AND W ONTARIO. THE N LOW WILL BE FAIRLY
PROGRESSIVE...MOVING OVER LAKE SUPERIOR BY 12Z THURSDAY AND EXITING
ACROSS LOWER MI THURSDAY NIGHT...MERGING WITH THE STRONGER LOW
ACROSS TN. THIS WILL BRING THE BEST CHANCE OF WIDESPREAD SNOW FOR
THIS LONG TERM PERIOD...WILL LIKELY BE LATE THURSDAY INTO EARLY
FRIDAY. AT THIS POINT THE GFS IS THE MOST ROBUST WITH THE SNOW WITH
1-4IN CWA WIDE. THE ON THE POSITIVE SIDE THE DGZ IS WITHIN THE
MOISTURE LAYER...BUT INVERSION HEIGHTS LOOK TO FALL PRETTY QUICKLY
OVERNIGHT THURSDAY NIGHT INTO FRIDAY MORNING. FAVORABLE UPSLOPE
CONDITIONS FOR LES DO NOT SEEM TO RETURN TO THE CWA UNTIL LATE
THURSDAY AFTERNOON IN THE FORM OF NW WIND BEHIND THE EXITING SFC
LOW. THEY WILL NOT BE ALL THAT STEADY FOR SIGNIFICANT DOMINANT BANDS
TO DEVELOP AS WINDS SHIFT OUT OF THE N-NNE BY DAYBREAK FRIDAY. A
GENERAL 500MB TROUGH WILL BE SETUP ACROSS THE UPPER GREAT LAKES
THROUGH THE GULF OF MEXICO W THURSDAY-FRIDAY...KEEPING COOLER AIR
OVER THE AREA. 850MB TEMPS WILL REMAIN -7 TO -14C.
LOOK FOR A SIGNIFICANT RIDGE OF HIGH PRESSURE AT 500MB FRIDAY NIGHT
TO EXTEND FROM THE INTERIOR SW UP THROUGH THE PLAINS TO PUSH INTO
THE UPPER GREAT LAKES AS THE S TROUGH DEEPENS TO A LOW AND BEGINS TO
EXIT OFF THE MID ATLANTIC SEABOARD. THIS 500MB LOW WILL PUSH N JUST
OFF THE NEW ENGLAND COAST BY SUNDAY MORNING. WAA WILL RESULT...AS
850MB TEMPS RISE TO -5 TO -10C BY 06Z SATURDAY /WARMEST OFF THE
ECMWF/...AND -1 TO -5C BY 00Z SUNDAY ON SW 850MB WINDS NEARING 35KTS.
THERE ARE SOME DIFFERENCES IN THE HANDLING OF THE 500MB LOW OVER N
CANADA FOR THE END OF THE UPCOMING WEEKEND. WHILE BOTH THE GFS AND
ECMWF SHOW A DEEP TROUGH SWINGING ACROSS MUCH OF THE NATION...THE
GFS IS FARTHER S WITH THIS FEATURE. EXPECT SOME STEADY SNOW TO SLIDE
IN FROM THE S SUNDAY EVENING INTO EARLY MONDAY...BUT TIMING AND
INTENSITY COULD CHANGE SIGNIFICANTLY BETWEEN NOW AND THEN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1131 PM EST MON JAN 18 2016
AT KIWD...EXPECT IFR VSBY/CISG DURING THE HEAVIER SNOW BANDS AT IWD
EARLY IN THIS FORECAST...BUT THEN WINDS BACKING LATE TONIGHT WILL
ALLOW FOR IMPROVEMENT TO MVFR IN LIGHTER LAKE EFFECT SHOWERS. EXPECT
A RETURN TO VFR CONDITIONS TUE AFTERNOON AS WINDS BACK TO THE SW.
AT KCMX...CONTINUED LAKE EFFECT SNOW SHOWERS WILL STILL RESULT IN
PREVAILING IFR/LOW MVFR CONDITIONS THROUGH TUE AFTERNOON BEFORE
MVFR CONDITIONS RETURN BY TUE NIGHT.
AT KSAW...EXPECT MVFR EARLY THIS MORNING AS WINDS VEER FROM NW TO
NNW AND SOME LIGHT LAKE EFFECT SNOW BRUSHES THE AREA. BACKING WINDS
LATE TONIGHT WILL ALLOW IMPROVEMENT AGAIN TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST MON JAN 18 2016
EXPECT WINDS TO DIMINISH LATER THIS EVENING TO 20-25 KTS...HIGHEST
OVER ERN LAKE SUPERIOR. IN ADDITION...HEAVY FREEZING SPRAY IS
EXPECTED WILL ALSO END EARLY THIS EVENING. WINDS ARE EXPECTED TO
SLOWLY DIMINISH TOWARDS THE MIDDLE OF THE WEEK...AS HIGH PRESSURE
MOVES OVER THE UPPER GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR MIZ006-085.
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST TUESDAY FOR MIZ014.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ001>003-
084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
415 AM EST TUE JAN 19 2016
.SYNOPSIS... COLD CONTINUES INTO TODAY UNDER HIGH PRESSURE.
WEAKENING SYSTEM WEDNESDAY COULD LEAVE MINOR SNOW ACCUMULATIONS.
POTENTIAL FOR A SIGNIFICANT WINTER STORM THURSDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
PESKY STRATOCU HOLDING STRONG IN THE MOUNTAINS WITH SCT FLURRIES
OR ICE CRYSTALS FALLING. OUTSIDE OF THAT...A PASSING S/W TROF
MAY BRING SOME CLOUDS INTO THE AREA THRU MORNING...ESPECIALLY
ACROSS NE KY/S WV/ AND SW VA WHERE A PASSING FLURRY CANNOT BE
RULED OUT.
HIGH PRESSURE BUILDS INTO THE REGION TODAY WHICH WILL FURTHER
DIMINISH THE WIND. STILL COULD SEE SOME GUSTS IN THE N MOUNTAINS
THOUGH. HI RES MODELS TRYING TO SHOW SOME AFTERNOON STREAKY STRATOCU
DEVELOPING OVER SE OH AND N WV AGAIN TODAY. BUMPED SKY COVER UP A
BIT THERE BUT NOT TO THE DEGREE THE HRRR WOULD SUGGEST. TEMPS TODAY
SHOULD RECOVER ABOUT 5 DEGREES FROM YESTERDAY BUT STILL COLD
OVERALL.
WITH HIGH PRESSURE OVERHEAD TONIGHT...EXPECTING A QUICK FALL IN
TEMPS THIS EVENING...ESPECIALLY OVER AREAS THAT HAVE SNOW ON THE
GROUND. HOWEVER...MID AND HI CLOUDS WILL BE ADVANCING TOWARD THE
AREA LATE WHICH WILL CAP THE FREE FALL. WAA ALOFT WILL ALSO COMMENCE
WHICH SHOULD ALLOW THE HIGHER ELEVATIONS TO SEE A SLOW RISE
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
THE WEAKENING SUPPORT/LIFT ON WEDNESDAY WILL WORK HARD TO SATURATE THE COLUMN
IN THE INITIALLY DRY ARCTIC AIR.
FEATURE IS A COMBO OF A 500 MB TROF AND WARM AIR ADVECTION IN THE LOW LEVELS.
FOR EXAMPLE...THE 850 MB FLOW OF 30 TO 40 KNOTS IS PERPENDICULAR TO THE
850 MB ISOTHERMS VCNTY STL TUESDAY EVENING. BY 18Z WEDNESDAY...THE FLOW
IS ALMOST PARALLEL TO THE ISOTHERMS. NOT MUCH CHANGE TO OUR 1 TO 2 INCH
FORECAST...BUT DID TRY TO DAMPEN THE NORTHERN COUNTIES...INCLUDING THE
ROUTE 50 CORRIDOR TO MOSTLY AN INCH OR LESS OF SNOW ACCUMULATION ON
WEDNESDAY.
MEANWHILE...TRIED TO BOOST PORTIONS OF NORTHEAST KENTUCKY...THE SOUTHERN
COAL FIELDS OF WEST VIRGINIA...BUCHANAN AND DICKENSON COUNTIES IN VIRGINIA
MORE TOWARD THE 2 INCH ACCUMULATION. IF SYSTEM DOES NOT DAMPEN QUICKER
THAN EXPECTED...WINTER WX ADVISORIES WILL LIKELY BE POSTED IN SOME COUNTIES
THAT HAVE THE 2 INCH CRITERIA...WHICH IS THE SAME THEME AS YESTERDAY.
WILL CUT BACK ON HIGH TEMPERATURES IN THE SOUTHWEST ON WEDNESDAY...WHERE
THE SNOW WILL LIKELY REACH THE GROUND IN THE MORNING.
WEDNESDAY SYSTEM LEAVES THE LOW ELEVATIONS SATURATED...COULD NOT COMPLETELY
RULE OUT SOME FREEZING DRIZZLE IN THE MOUNTAINS OR SOUTHERN COUNTIES OVERNIGHT
WEDNESDAY NIGHT IN THE WAKE OF THE SYNOPTIC LIGHT SNOW. YET...WILL NOT INSERT
YET INTO THE FORECAST. NORTHERN COUNTIES HAVE A BETTER CHANCE OF THE
LOWER CLOUDS BREAKING UP BEFORE DAWN THURSDAY.
WILL SLOW DOWN THE INCREASING POPS LATE THURSDAY IN THE EXTREME SOUTH A
FEW HOURS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ON THE MIDNIGHT SHIFT THIS TUESDAY MORNING...NO REASON TO MAKE MAJOR CHANGES
TO OUR GRIDS FOR THE MAJOR STORM. AS WE KNOW...MAJOR ADJUSTMENTS ARE WISER
AS WE GET CLOSER...INSTEAD OF SEESAWING DAYS AWAY.
WITH THE MID LEVEL AND 850 MB LOW STILL TO OUR WEST ON FRIDAY...AND A STRONG
SOUTHERLY 40 KNOT 850 MB FLOW INTO SOUTHERN WEST VIRGINIA...WE STILL LIKE
THE FORECAST RAIN WORKING NORTH OVERNIGHT THURSDAY NIGHT INTO FRIDAY
FOR SOUTHERN COUNTIES. WILL NOT ADD A WATER
HAZARD AS OF YET...BUT AGAIN...EVEN THAT COULD NOT BE COMPLETELY RULED
OUT FOR SOUTHERN COUNTIES.
HOW FAR AND QUICKLY THAT WORKS...IS THE QUESTION. WITH SOME SE COMPONENT
THOUGH IN POCAHONTAS COUNTY...WE STILL LIKE KEEPING MOSTLY SNOW IN
POCAHONTAS COUNTY.
00Z ECMWF STILL A BIT FURTHER SOUTH WITH THE MID LEVEL AND 850 MB LOW
CIRCULATION...AND THUS A BIT COLDER AT CRITICAL 850 MB LEVEL.
DID INCREASE POPS FRIDAY NIGHT INTO SATURDAY MORNING IN THE STRONG WRAP
AROUND FROM THE DEEPENING STORM.
REST OF THIS LONG TERM IS FROM OUR LATE MONDAY PACKAGE...
MODELS AGREE ON THE POTENTIAL FOR A MAJOR WINTER WEATHER SYSTEM
IMPACTING THE AREA EARLY IN THE PERIOD.
A MIDSTREAM UPPER LEVEL S/W TROUGH DIGS SEWD THROUGH THE SRN
PLAINS STATES THU...TOWARD A L/W TROUGH POSITION E OF THE
MISSISSIPPI RIVER...WITH A RIDGE BUILDING TO ITS W. THE S/W
TROUGH CLOSES OFF FRI...TRACKS ACROSS THE SRN APPALACHIANS FRI
NT...AND THEN MEANDERS UP ALONG THE ERN SEABOARD ON SAT.
THE INITIAL SFC LOW CENTER TRACKS NEWD INTO SE KY AND SW VA THU
EVENING...WITH THE INVERTED LOW LEVEL TROUGH EXTENDING NWD UP
ALONG THE OHIO RIVER...PEAKING THE WARM WEDGE EFFECT AT THAT TIME.
THAT CENTER THEN FILLS OVERNIGHT AS THE NEW LOW CENTER GETS GOING
ALONG THE EASTERN SEABOARD. THAT CENTER SLOWLY MEANDERS UP THE
EASTERN SEABOARD SAT AND SAT NT...BEFORE FINALLY PULLING OUT TO
SEA ON SUNDAY.
THIS SCENARIO IS LIKELY TO RESULT IN SNOW OVERSPREADING THE AREA
FROM S TO N THU NT...WITH A TRANSITION TO SLEET AND THEN RAIN
INTO CENTRAL PORTIONS OF THE FCST AREA FROM THE S. FREEZING RAIN
IS ALSO POSSIBLE IN THE TRANSITION. THE HIGHEST LOW LEVEL
TEMPERATURES WILL OCCUR IN THE WARM WEDGE BETWEEN THE OHIO RIVER
AND THE WV MOUNTAINS. SFC TEMPERATURES SHOULD PEAK MID TO LATE
AFTERNOON FRI...BUT THE WARM WEDGE ALOFT STARTS PUSHING EWD LATE
FRI AFTERNOON. THIS COMBINATION KEEPS THE FREEZING RAIN POTENTIAL
IN THE MORNING AND MIDDAY FRI...MAINLY FOR SRN PORTIONS OF THE
AREA AND ALONG THE ERN SLOPES OF THE SRN WV MOUNTAINS.
ACCUMULATIONS THU NT AS LIKELY TO BE LIMITED OVER THE SRN COAL
FIELDS OF WV ON ACCOUNT OF SFC TEMPERATURES THERE GETTING ABOVE
FREEZING SOON AFTER THE ONSET OF THE PRECIPITATION. AN INCH OR
TWO ARE POSSIBLE ELSEWHERE BY DAWN FRI...DEPENDING UPON HOW
QUICKLY SLEET MIXES IN RELATIVE TO THE ONSET TIME OF THE
PRECIPITATION. THE CENTRAL MOUNTAINS APPEAR MOST LIKELY TO GET
SEVERAL INCHES BY DAWN FRI AS THAT IS WHERE THERE IS LIKELY TO BE
THE MOST TIME BETWEEN THE ONSET OF THE PRECIPITATION AND THE
ARRIVAL OF ABOVE FREEZING TEMPERATURES ALOFT.
AS THE UPPER LEVEL LOW ROLLS S OF THE AREA FRI NT...THE LOW LEVEL
INVERTED TROUGH AND WARM WEDGE COLLAPSE...AND TEMPERATURES FALL
BELOW FREEZING THROUGHOUT THE COLUMN THROUGHOUT THE FCST AREA.
SNOW ACCUMULATIONS WILL DEPEND UPON THE PROGRESS OF THE WARM
WEDGE ON FRI...AND THEN HOW MUCH FORCING / DEFORMATION EXISTS OVER
THE AREA FRI NT AS THE COLD AIR SETTLES IN.
THE AIR MASS BEHIND THIS SYSTEM WILL ACTUALLY BE OF PACIFIC ORIGIN
AND THUS BE ONLY SEASONABLY CHILLY...AND THE NEXT WARM ADVECTION
SYSTEM NEXT MON BRINGS THE CHANCE FOR A LIGHT SNOW TO RAIN
TRANSITION.
WPC TEMPERATURES LOOKED REASONABLE AND WERE GENERALLY BLENDED IN.
HAVE TEMPERATURES RISING TOWARD DAWN FRI WITH THE WARM WEDGE
EFFECT BEGINNING TO TAKE HOLD...USED GFS BASED TEMPERATURES IN
ADDITION TO WPC DURING THE STORM...THU NT INTO SAT.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR CONDITIONS EXCEPT MVFR CIGS IN THE MOUNTAINS THRU THIS
MORNING. SOME -SHSN AND FLURRIES EXPECTED THROUGH AROUND 12Z
TUESDAY ACROSS THE NORTHERN MOUNTAIN ZONES AS WELL AS SE
OH...CREATING BRIEF LOW VFR OR EVEN BRIEF MVFR VSBYS.
OTHERWISE...VFR WITH LIGHT WEST TO WEST- NORTHWESTERLY WINDS.
AFTERNOON MVFR STRATOCU MAY DEVELOP AGAIN ACROSS SE OH AND N
WV...AFFECTING KPKB/KCKB/KEKN WITH A PERIOD OF BKN MVFR CIGS.
MID AND HI CLOUDS ADVANCE INTO THE AREA FROM THE W TONIGHT AS ANY
REMAINING STRATOCU DISSIPATES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE...HIGH
ALTERNATE SCENARIOS: NONE
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.
DATE TUE 01/19/16
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
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 M M M M M M M M M M M M
PKB CONSISTENCY H H H H H H H H H M M M
CKB CONSISTENCY H H H H H H H H H H M M
AFTER 06Z WEDNESDAY...
UPPER AIR DISTURBANCE WEDNESDAY/WEDNESDAY NIGHT COULD BRING LIGHT SNOW
WITH IFR.
IFR POSSIBLE WITH A WINTER STORM SYSTEM THURSDAY NIGHT INTO
SATURDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR WVZ038-046-047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/30
NEAR TERM...30
SHORT TERM...KTB
LONG TERM...TRM
AVIATION...30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
457 AM EST TUE JAN 19 2016
.SYNOPSIS...
ACCUMULATING LAKE EFFECT SNOW WILL END THIS MORNING. LIGHT SNOW
IS POSSIBLE LATER WEDNESDAY. A MAJOR WINTER STORM COULD BRING
SIGNIFICANT SNOWFALL TO MUCH OF CENTRAL PA FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MODELS DEPICT A STRONG LOBE OF VORTICITY SWINGING THROUGH PA BY
18Z. HRRR SHOWS LES BANDS WEAKENING THROUGH THE MORNING BEFORE
TAPERING OFF BY TONIGHT...AS INCREASINGLY ANTICYCLONIC LOW TO MID
LEVEL FLOW PUSHES ACROSS THE LAKES. WITH ONLY MINOR ADDITIONAL LES
ACCUMULATIONS EXPECTED...WILL ALLOW THE LES HEADLINES EXPIRE AS
SCHEDULED AT 12Z/7AM. WIND CHILL HAZARD ALSO ON TRACK TO EXPIRE AT
10AM AS MINIMUM WIND CHILLS TREND INTO THE NEGATIVE SINGLE DIGITS.
OVERALL IT WILL BE ANOTHER BRISK AND VERY COLD DAY WITH WIND
CHILLS IN THE SINGLE DIGITS +/- ZERO. WEAK RIDGING SURFACE AND
ALOFT SLIDES INTO THE AREA FROM THE OH VALLEY TONIGHT WITH NO
SIGNIFICANT WEATHER EXPECTED. LOWS WILL RANGE FROM THE POSITIVE
SINGLE DIGITS IN THE LAURELS TO THE MID TEENS ACROSS THE MID TO
LOWER SUSQUEHANNA VALLEY.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
SPLIT FLOW TROUGH WILL MIGRATE QUICKLY EASTWARD FROM THE PLAINS TO
THE EAST COAST BY 21/1200Z. MODELS SHOW THE NORTHERN STREAM SYSTEM
BEING MORE AMPLIFIED AS IT TRACKS FROM THE MIDWEST THROUGH THE NRN
MID-ATLANTIC STATES. WITH MOISTURE LACKING...MODEST HEIGHT FALLS
COULD COMBINE WITH WEAK WAA TO BRING A PERIOD OF LIGHT SNOW OVER
THE ALLEGHENY RIDGES LATER WEDNESDAY INTO WEDNESDAY NIGHT. ANY
SNOW ACCUMS WOULD BE AN INCH OR LESS BASED ON BLENDED MEAN QPF.
FOLLOWING THE PASSAGE OF THE AFOREMENTIONED NORTHERN STREAM
SYSTEM...LAKE EFFECT TRAJECTORIES BECOME REESTABLISHED WITH MINOR
ACCUMS POSSIBLE IN THE NORTHWEST SNOWBELT. THE LES CONNECTION
APPEARS TO BE RATHER SHORT-LIVED ESPECIALLY FROM ERIE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THURSDAY FCST/DAY 3 WX LOOKS QUIET UNDER HIGH PRESSURE. ALL EYES
WILL TURN TO LOW PRESSURE SYSTEM DEVELOPING INTO THE TN VALLEY
AND SOUTHERN APPALACHIANS BY THURSDAY NIGHT.
THE PRIMARY IMPACTS THIS PERIOD WILL BE FOR GROWING CONFIDENCE IN
A MAJOR EAST COAST WINTER STORM INCLUDING HEAVY SNOW POTENTIAL IN
CENTRAL PENNSYLVANIA. EXPECT THE MODEL SPREAD WITH THIS SYSTEM TO
CONTINUE TO NARROW AS THE UPPER LEVEL FEATURE COMES ONSHORE OVER
THE PACIFIC NW TONIGHT. WHILE IT IS STILL TO EARLY TO GET INTO THE
SPECIFIC DETAILS...HERE ARE SOME EARLY GOAL POSTS:
PTYPE: MODEL CONSENSUS AT THIS TIME FAVORS SNOW AS THE PRIMARY
WINTER PTYPE NEAR AND NORTHWEST OF THE I-95 URBAN CORRIDOR
TIMING: GFS/CMC/WPC QPF WOULD SUGGEST A FRIDAY MORNING ONSET
SPREADING FROM SOUTH TO NORTH BY THE AFTERNOON. THE ECMWF IS
SLOWER.
DURATION: SNOW COULD LAST THROUGH SATURDAY BEFORE ENDING SATURDAY
NIGHT/EARLY SUNDAY MORNING.
GREATEST RISK FOR HEAVY SNOW: SOUTH-CENTRAL AND SOUTHEASTERN
ZONES OR ROUGHLY THE SOUTHEAST 1/2 TO 1/3 OF THE CWA. BLOWING AND
DRIFTING POSSIBLE.
IMPROVING CONDITIONS LIKELY ARE ON SUNDAY WITH HIGH PRESSURE
RETURNING TO THE AREA. TEMPERATURES ARE FCST TO TREND WARMER TO
NEAR NORMAL LEVELS BY MONDAY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
PERSISTENT SNOW BAND REMAINS ACROSS THE NW MTNS. THIS CONTINUES TO
BRING IFR VSBYS TO BFD. NEAR TERM MDL DATA CONTINUES TO INDICATE LAKE
EFFECT PLUME WILL SHIFT SOUTH AFTER MIDNIGHT...FAVORING
PREDOMINANTLY IFR CONDS BTWN 05Z- 12Z. EXPECT FOR THESE CONDITIONS
TO REMAIN SO THROUGH THE EARLY MORNING HOURS. THE GUSTY FLOW
SHOULD CONTINUE THE LAKE EFFECT THROUGH THE MORNING. THE WINDS
SHOULD SHIFT TO THE NORTH...THOUGH THIS ALONE WILL NOT CEASE ANY
SHOWERS. HOWEVER...A BUILDING RIDGE WILL REDUCE INSTABILITY
ENOUGH TUESDAY AFTERNOON TO END SHOWER ACTIVITY AND ALLOW FOR
IMPROVING CONDITIONS.
IMPROVING CONDS AT KJST...THOUGH RADAR INDICATES A BAND OF SHOWERS
TO THE NORTH...THAT IF IT MOVES SOUTH COULD BRING BACK IFR
CONDITIONS TO JST. THIS COULD HAPPEN BETWEEN 06Z TO 09Z...HOWEVER
MVFR CONDITIONS SHOULD REMAIN DOMINATE THROUGH THIS TIMEFRAME
OUTSIDE ANY BRIEF PERIODS OF IFR IN PASSING SHOWERS. FOR THE REST
OF CENTRAL PA...THE DRYING EFFECT OF DOWNSLOPING WESTERLY FLOW
SHOULD YIELD VFR FLYING OVERNIGHT.
HIGH PRESSURE BUILDING IN FROM THE MIDWEST WILL CAUSE LAKE EFFECT
SNOW TO TAPER OFF ACROSS THE NW MTNS TUESDAY. HOWEVER...RESIDUAL
LOW LVL MOISTURE ASCENDING THE ALLEGHENIES SHOULD CAUSE MVFR
STRATOCU TO PERSIST INTO TUE EVENING AT KBFD AND KJST. AFTER A BIT
OF A LULL IN THE WINDS OVERNIGHT...EXPECT GUSTY WINDS TO REDEVELOP ACROSS
THE ENTIRE AREA FROM LATE AM THRU EARLY EVENING TUES...AS DIURNAL
HEATING/DEEPENING BLYR DEPTH ALLOW STRONGER WINDS TO MIX TO THE
SFC. BUFKIT SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS TUE AFTN.
OUTLOOK...
WED...A BRIEF EVENING -SHSN/VIS REDUCTION POSSIBLE KJST/KBFD.
THU...NO SIG WX EXPECTED.
FRI...SNOW POSSIBLE...ESP SOUTH.
SAT...SNOW/WIND POSSIBLE...ESP SOUTH/EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR
PAZ004-005.
WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ024-
033.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
126 AM EST TUE JAN 19 2016
.SYNOPSIS...
A WESTERLY FLOW OF ARCTIC AIR WILL CAUSE LAKE EFFECT SNOWS ACROSS
NORTHWESTERN PENNSYLVANIA TONIGHT AND EARLY TUESDAY. HIGH
PRESSURE WILL THEN PROVIDE MAINLY DRY WEATHER THROUGH THURSDAY. A
SURFACE LOW WILL DEVELOP OVER THE DEEP SOUTH ON FRIDAY AND DEEPEN
AS IT MOVES NORTHEAST TO THE MID-ATLANTIC COAST. THIS STORM HAS
THE POTENTIAL TO BRING A WIDESPREAD SIGNIFICANT SNOWFALL TO THE
MID-ATLANTIC REGION.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LAKE EFFECT SNOW ADVISORY CANCELLED FOR ELK CAMERON AND POTTER.
LAKE EFFECT SNOW WARNINGS CONTINUE FOR WARREN AND MCKEAN...AS WELL
AS WIND CHILL ADVISORIES FOR CAMBRIA AND SOMERSET.
UPSLOPE FLOW INTO THE WEST CENTRAL AND NORTHWEST MOUNTAINS IS
MAINTAINING NEARLY CONSTANT BUT LIGHT 1-2SM -SN IN THE WRN AND
NORTHWEST MTNS. SNOWBANDS HAVE SHIFTED SOUTH THIS EVENING BACK
OVER THE LE WARNING AREA. LATEST HRRR CONTINUES TO INDICATE THAT
THESE WILL SAG SOUTHWARD IN THE BACKING FLOW OVERNIGHT. WILL ADD
TO EARLIER TOTALS OVERNIGHT AS A RESULT...AND THUS LAKE EFFECT
WARNINGS CONTINUE.
WIND CHILL ADVY STILL SOLID IN THE ADVY AREA AND TEMPS GETTING
COLDER TONIGHT. MINS WILL GET INTO THE SINGLE DIGITS FOR MUCH OF
THE AREA...WITH DOUBLE DIGITS HERE AND THERE - MAINLY IN THE
VALLEYS OF THE EAST. SOME SOTS IN THE LAURELS LIKE MEYERSDALE
COULD GET BELOW 0F AIR TEMP.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
HIGHEST MOISTURE DISSIPATES IN PLACE ON TUESDAY AFTER THE PASSAGE
OF A STRONG VORT MAX AROUND SUNRISE. BUT SOME UPSLOPE/FLURRIES
MAY LINGER IN THE LAURELS FOR THE MORNING AND SHSN IN THE NW FOR
MUCH OF THE DAY DUE TO FAVORABLE FETCH AND TEMPS. HOWEVER...THE
SIG ACCUMS SHOULD BE TAPERING OFF IN THE MORNING. SUBSIDENCE
SHOULD HELP TO SQUASH THE VERTICAL MOTION/INSTABILITY. WARNING
ONLY GOES UNTIL 12Z...EXP TIMING THERE S/B FINE EVEN IF SOME LIGHT
ACCUMS LINGER. THE WORST OF IT WILL BE OVER BY THEN. WILL LINGER
CLOUDS ACROSS THE N FOR MOST OF THE DAY. MAXES SHOULD BE 2-7F
MILDER THAN TODAY WITH MORE SUN AND SLIGHTLY HIGHER 8H TEMPS AND
MIXING. WIND CHILLS WILL INCREASE SLIGHTLY AS THE TEMPS DO. THIS
SHOULD ALLOW THE WC ADVY TO EXPIRE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
POTENTIAL WINTER STORM COULD BRING IMPACTS TO CENTRAL PA FRI INTO
SAT NIGHT.
1035MB SURFACE HIGH STRETCHING FROM THE UPPER MIDWEST THROUGH THE
OHIO VALLEY WILL WEAKEN SOMEWHAT AS IT SPREADS INTO THE AREA LATE
TUESDAY...AHEAD OF A WEAKENING AND MOISTURE-CHALLENGED ALBERTA
CLIPPER WHICH WILL BRING A CHANCE OF LIGHT SNOW SHOWERS TO MAINLY
WESTERN SECTIONS WEDNESDAY NIGHT...WITH ONLY MINOR ACCUMULATIONS
EXPECTED.
HIGH RE-ESTABLISHES OVER CENTRAL PA THU...THOUGH THIS TIME ONLY
IN THE 1024-1028MB RANGE...AND RETREAT NORTHWARD ON FRI. AT THE
SAME TIME...LOW PRESSURE EXPECTED TO DEEPEN OVER SOUTHERN
APPALACHIANS AND MOVE ACROSS MID-ATLANTIC STATES FRI NIGHT AND
SAT. THOUGH POTENTIAL WINTER STORM REMAINS SEVERAL DAYS OUT...AND
SHORTWAVE ENERGY AT THIS TIME REMAINS WELL OUT OVER THE PACIFIC
OCEAN...MOST EXTENDED MODEL GUIDANCE APPEARS TO BE LATCHING ON TO
AND TRACKING IT FAIRLY WELL. THE WAVE SHOULD ARRIVE ON THE PACIFIC
COAST TUE NIGHT AND DROP INTO THE CENTRAL PLAINS ON THU. COMBO OF
THE EARLIER-IN-THE-WEEK CLIPPER AND THIS WAVE CARVE OUT A
SHARPENING TROUGH FOR THE EAST COAST LATE WEEK AS RIDGE FORMS OVER
THE ROCKIES. LATEST 12Z GEFS AND OPERATIONAL GFS REVEAL NO BIG
CHANGES WITH 12Z ECMWF HUGGING THE MID ATLANTIC COAST A BIT
LONGER...THOUGH THIS FAR OUT THE MODELS STILL OVERALL APPEAR IN
FAIRLY GOOD BASIC AGREEMENT WITH TIMING AND TRACK OF LOW
PRESSURE AS IT STRENGTHENS.
BASED ON MODEL CONSENSUS THIS FAR OUT...THERE CONTINUES TO BE
MEDIUM CONFIDENCE FOR A SIGNIFICANT WINTER STORM OVER THE MID
ATLANTIC AND NORTHEAST FRIDAY AFTERNOON THROUGH SATURDAY...
WITH BIGGEST POTENTIAL IMPACTS TO CWA BEING ROUGHLY THE SOUTHEAST
HALF. CONSENSUS PTYPE IS SNOW...WITH PLENTY OF COLD AIR IN
PLACE. KEEP IN MIND THAT OBVIOUSLY IT/S STILL FAR TOO EARLY TO
SAY FOR CERTAIN 4-5 DAYS OUT...ESPECIALLY WHEN THE WAVE DRIVING
THIS ISN/T EVEN TO THE WEST COAST YET. THERE ARE STILL A LOT OF
VARIABLES IN PLAY THAT COULD IMPACT THE EVOLUTION OF THIS SYSTEM.
LOOKING PAST THE STORM AFTER IT MOVES AWAY SAT NIGHT AND
SUNDAY...PACIFIC HIGH PRESSURE LOOKS TO BUILD INTO THE REGION
PROVIDING GENERALLY FAIR AND MILDER CONDS THAN WE WILL SEE FOR
MOST OF THIS WEEK. A CLIPPER MAY BRING ANOTHER ROUND OF LIGHT SNOW
TO THE NORTH AND WEST EARLY NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
PERSISTENT SNOW BAND REMAINS ACROSS THE NW MTNS. THIS CONTINUES TO
BRING IFR VSBYS TO BFD. NEAR TERM MDL DATA CONTINUES TO INDICATE LAKE
EFFECT PLUME WILL SHIFT SOUTH AFTER MIDNIGHT...FAVORING
PREDOMINANTLY IFR CONDS BTWN 05Z- 12Z. EXPECT FOR THESE CONDITIONS
TO REMAIN SO THROUGH THE EARLY MORNING HOURS. THE GUSTY FLOW
SHOULD CONTINUE THE LAKE EFFECT THROUGH THE MORNING. THE WINDS
SHOULD SHIFT TO THE NORTH...THOUGH THIS ALONE WILL NOT CEASE ANY
SHOWERS. HOWEVER...A BUILDING RIDGE WILL REDUCE INSTABILITY
ENOUGH TUESDAY AFTERNOON TO END SHOWER ACTIVITY AND ALLOW FOR
IMPROVING CONDITIONS.
IMPROVING CONDS AT KJST...THOUGH RADAR INDICATES A BAND OF SHOWERS
TO THE NORTH...THAT IF IT MOVES SOUTH COULD BRING BACK IFR
CONDITIONS TO JST. THIS COULD HAPPEN BETWEEN 06Z TO 09Z...HOWEVER
MVFR CONDITIONS SHOULD REMAIN DOMINATE THROUGH THIS TIMEFRAME
OUTSIDE ANY BRIEF PERIODS OF IFR IN PASSING SHOWERS. FOR THE REST
OF CENTRAL PA...THE DRYING EFFECT OF DOWNSLOPING WESTERLY FLOW
SHOULD YIELD VFR FLYING OVERNIGHT.
HIGH PRESSURE BUILDING IN FROM THE MIDWEST WILL CAUSE LAKE EFFECT
SNOW TO TAPER OFF ACROSS THE NW MTNS TUESDAY. HOWEVER...RESIDUAL
LOW LVL MOISTURE ASCENDING THE ALLEGHENIES SHOULD CAUSE MVFR
STRATOCU TO PERSIST INTO TUE EVENING AT KBFD AND KJST. AFTER A BIT
OF A LULL IN THE WINDS OVERNIGHT...EXPECT GUSTY WINDS TO REDEVELOP ACROSS
THE ENTIRE AREA FROM LATE AM THRU EARLY EVENING TUES...AS DIURNAL
HEATING/DEEPENING BLYR DEPTH ALLOW STRONGER WINDS TO MIX TO THE
SFC. BUFKIT SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS TUE AFTN.
OUTLOOK...
WED...A BRIEF EVENING -SHSN/VIS REDUCTION POSSIBLE KJST/KBFD.
THU...NO SIG WX EXPECTED.
FRI...SNOW POSSIBLE...ESP SOUTH.
SAT...SNOW/WIND POSSIBLE...ESP SOUTH/EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR
PAZ004-005.
WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ024-
033.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1058 PM CST MON JAN 18 2016
.UPDATE...
ISSUED AT 854 PM CST MON JAN 18 2016
THE 00Z NAM HAS BEGUN TO COME IN AND IT IS DIGGING THE UPPER WAVE
CURRENTLY OVER MONTANA FARTHER SOUTH AS IT MOVES INTO THE EASTERN
PLAINS. THIS PUTS THE STRONGEST FORCING FOR ASCENT INTO EASTERN
NEBRASKA MORE QUICKLY. WITH ONLY WEAK LIFT OVER MUCH OF SOUTHWEST
MINNESOTA AND EAST CENTRAL SOUTH DAKOTA...IT IS GOING TO TAKE
LONGER TO OVERCOME THE LOW LEVEL DRY AIR. BOTH THE OPERATIONAL AND
EXPERIMENTAL HRRR AS WELL AS THE RAP NOW HAVE SNOW REACHING SIOUX
CITY BETWEEN 6 AND 8 AM AND SIOUX FALLS BETWEEN 8 AM AND 11 AM.
GIVEN PROGRESSION OF UPPER WAVE...THAT SEEMS REASONABLE AND HAVE
SLOWED SNOW PROGRESSION TO THE EAST. THIS MEANS A LITTLE LESS SNOW
FOR I-29 CORRIDOR NORTH OF BERESFORD WITH SNOWFALL NOW EXPECTED TO
BE CLOSER TO AN INCH THAN TWO INCHES.
UPDATED GRIDS AVAILABLE SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 313 PM CST MON JAN 18 2016
STRATUS SHIELD ACROSS THE NORTHEAST HALF OF THE CWA WAS SLOWER TO
CLEAR/THIN TODAY THAN EXPECTED...BUT APPEARS THAT IT IS ON ITS WAY
BASED ON SCATTERING REPORTED IN SURFACE OBSERVATIONS OVER THE PAST
HOUR OR TWO. STILL ON THE CLOUDIER SIDE THIS AFTERNOON THOUGH...WITH
THICKER HIGH CLOUDS SPILLING INTO THE REGION IN ADVANCE OF SYSTEM
SET TO AFFECT THE AREA TONIGHT/TUESDAY.
THIS SYSTEM NOW MOVING OUT OF THE NORTHERN ROCKIES AND IS SLATED TO
SLIDE ACROSS THE PLAINS AS TONIGHT THROUGH TUESDAY EVENING. LEADING
MID LEVEL WARM FRONT RESPONSIBLE FOR THE THICKER CLOUDS WILL HAVE
LITTLE IMPACT ON SNOW DEVELOPMENT. AS SOUTHERN PORTION OF THE WAVE
DIGS MORE STRONGLY INTO THE SOUTHERN PLAINS...MODELS CONSISTENT IN
SHOWING AN INCREASE IN MID-LEVEL FRONTOGENESIS JUST SOUTH OF OUR
FORECAST AREA BY 12Z TUESDAY...AND THINK THIS WILL BE THE PRIMARY
FOCUS FOR HEAVIER SNOWFALL POTENTIAL AS THAT WAVE SWINGS THROUGH THE
CENTRAL PLAINS. STILL EXPECTING BROAD SWATH OF SNOW EXTENDING NORTH
THROUGH OUR AREA AS WEAKER/NORTHERN PORTION OF THE WAVE MOVES ACROSS
THE DAKOTAS INTO MINNESOTA. HOWEVER WITH FRONTAL FOCUS TO OUR SOUTH
AND SOUNDINGS INDICATING DEEP DRY LAYER WHICH WILL DELAY ONSET OF
ACCUMULATING SNOW A BIT...LOOKS LIKE SNOWFALL AMOUNTS IN OUR AREA
WILL BE A LITTLE LIGHTER THAN PREVIOUSLY FORECAST. STILL GOING FOR
AMOUNTS WITHIN THE 1-3 INCH RANGE FOR CWA...LIGHTEST IN AREAS NORTH
OF I-90 AND ESPECIALLY IN SOUTHWEST MN WHERE DRY LAYER PERSISTS THE
LONGEST.
TEMPERATURES TONIGHT ARE A LITTLE TRICKY AS MANY AREAS WARMED INTO
THE HIGHER END SINGLE DIGITS TO AROUND 10F...AND MANY MODELS DO NOT
HAVE A GREAT HANDLE ON THIS. WILL STILL SEE A DROPOFF IN TEMPS THIS
EVENING BEFORE LOW-MID CLOUDS BEGIN TO THICKEN/PUSH EAST...BUT MAIN
QUESTION IS HOW MUCH. HEDGES TOWARD WARMER END OF AVAILABLE GUIDANCE
NUMBERS...WHICH STILL DROPS FAR EASTERN CWA BACK BELOW ZERO DURING
THE EVENING BEFORE REBOUNDING TO NEAR/ABOVE ZERO BY DAYBREAK. AREAS
FARTHER WEST WILL LIKEWISE SEE EVENING LOWS...FOLLOWED BY STEADY TO
RISING TEMPERATURES LATE TONIGHT. SHOULD CONTINUE TO SEE A SLOW BUT
STEADY CLIMB INTO THE TEENS-LOWER 20S FOR HIGHS TUESDAY...WHICH MAY
SEEM LIKE A HEAT WAVE AFTER THE FRIGID WEEKEND WE JUST HAD.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 313 PM CST MON JAN 18 2016
LINGERING LIGHT SNOW WILL EXIT THE AREA TO THE EAST QUICKLY TUESDAY
EVENING AND AM LIMITING MENTION TO ONLY THE FIRST THREE HOURS OF
TUESDAY NIGHT. IT IS POSSIBLE THERE COULD BE FLURRIES A BIT LONGER
WITH LINGERING STRATUS...BUT ON THE OTHER HAND CAN SEE THE SNOW
ENDING BY 6PM...WHICH OF COURSE IS REFLECTED IN ONLY CHANCE POPS FAR
EAST FOR THAT EARLY EVENING. THE LINGERING STRATUS SHOULD CLEAR OUT
EVENTUALLY TO THE EAST AND NORTHEAST BUT HAVE GONE SLOWLY AS THERE
IS UNCERTAINTY IN STRATUS CLEARING OUT AT NIGHT IN A SOUTHERLY FLOW.
ADD THAT TO THE LIKELIHOOD OF IT REDEVELOPING BY WEDNESDAY NIGHT AS
A WEAK INVERTED TROUGH MOVES TOWARD THE AREA. PARTLY TO MOSTLY
CLOUDY COULD BE TOO BRIGHT FOR A WEDNESDAY FORECAST...BUT WILL GO
WITH THAT FOR NOW.
TUESDAY NIGHT AND WEDNESDAY SHOULD BE A BIT WARMER WITH HIGHS
WEDNESDAY IN THE 20S TO LOWER 30S...STRATUS OR NOT.
ALONG WITH POSSIBLE STRATUS REDEVELOPMENT WEDNESDAY NIGHT...A WEAK
NORTHERN BRANCH SHORT WAVE COULD BRING A LITTLE LIGHT SNOW SOUTH...
MAINLY TO THE MISSOURI RIVER AREA. THIS WAVE IS NOT ONLY WEAK BUT
WEAKENING FURTHER AS A STRONGER WAVE DIVES WELL SOUTH OF THE AREA TO
DEVELOP A SYSTEM THAT SHOULD KEEP PEOPLE IN THE EAST BUSY FOR A FEW
DAYS. THERE COULD BE A LITTLE LIGHT SNOW OR FLURRIES LINGER THURSDAY
IN THE CONTINUING LOW LEVEL MOISTURE AND CLOUD COVER BUT SUPPORT IS
HARD TO FIND AND WILL LEAVE IT MOSTLY CLOUDY WITHOUT PRECIPITATION
FOR NOW.
A FEW DEGREES OF COOLING IS EXPECTED THURSDAY BEHIND THE WEAK
TROUGH...BUT CERTAINLY NO RETURN TO THE ARCTIC COLD OF THE WEEKEND.
FRIDAY THROUGH SUNDAY SHOULD BRING MILDER TEMPERATURES AS UPPER
RIDGING ARRIVES IN THE CENTRAL PLAINS THEN IS FLATTENED A LITTLE BY
ANOTHER WEAK SHORT WAVE. THIS WEAK SHORT WAVE COULD BRING A LITTLE
LIGHT SNOW FOR SUNDAY...BUT AGAIN NOTHING TO GET VERY EXCITED ABOUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1058 PM CST MON JAN 18 2016
MAIN CONCERN CONTINUES TO BE SNOW LATER TONIGHT AND TOMORROW. MAIN
CHANGE TO FORECAST HAS BEEN TO SLOW DOWN THE ARRIVAL OF THE SNOW
ESPECIALLY AT KFSD. APPEARS SNOW WILL NOT ARRIVE UNTIL 15Z OR 16Z
AND WITH DRY AIR TO OVERCOME...VSBYS WILL PRIMARILY BE FROM 2 TO 4
MILES. STILL EXPECT 1 MILE VSBY AT KSUX WITH CIGS BELOW 2000 FT
FROM MID MORNING TO MOD AFTERNOON. AS BEFORE...COULD SEE VSBYS
BELOW 1 SM AT KSUX BUT DURATION LOOKS TO BE MAYBE AN HOUR OR TWO
AND COULD BE INTERMITTENT SO DECIDED TO KEEP WITH IFR CONDITIONS
ONLY. ONCE SNOW ENDS...VSYBS SHOULD IMPROVE BUT CIGS WILL STAY
AROUND 2000 FT THROUGH 06Z WEDNESDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...SCHUMACHER
SHORT TERM...JH
LONG TERM...
AVIATION...SCHUMACHER
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
352 AM PST TUE JAN 19 2016
.SYNOPSIS...RAIN THIS MORNING...HEAVY AT TIMES BEFORE TURNING TO
SHOWERS FOR THE MIDDAY AND AFTERNOON HOURS. HIGH PRESSURE BUILDS
TONIGHT THROUGH THURSDAY WITH A PERIOD OF DRY AND SEASONABLY MILD
WEATHER. NEXT FRONT ARRIVES THURSDAY NIGHT INTO FRIDAY WITH A
PERIOD OF LIGHT RAIN...POSSIBLY BECOMING HEAVY FOR A TIME FRIDAY
NIGHT WHEN THE UPPER LOW PASSES OVERHEAD WITH LINGERING SHOWERS
SATURDAY. LATEST INDICATIONS SHOW A RETURN OF DRY WEATHER SUNDAY
THROUGH THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...AS OF 3:52 AM PST TUESDAY...INITIAL RAIN BAND IS
MOVING ONSHORE AS OF THIS WRITING...MAINLY ARRIVING FROM THE WEST
WITH RAIN DEVELOPING OVER MOST OF THE DISTRICT. AMOUNTS SO FAR
HAVE BEEN LIGHT BUT THAT SHOULD CHANGE QUICKLY OVER THE NEXT
SEVERAL HOURS THAT WILL ENCOMPASS THE MORNING COMMUTE. SATELLITE
IMAGERY SHOWS RAPIDLY COOLING CLOUD TOPS OFFSHORE WITH INCOMING
JET STREAK AND ASSOCIATED SHORTWAVE. AMSU TPW SHOWS GOOD MOISTURE
TAP BUT BEST PLUME OF 1.5 TPW MAY STAY JUST OFFSHORE. LATEST
OBSERVED TRENDS SUGGESTS THAT SOME OF THE HEAVIEST RAIN MAY NOW
SHIFT SLIGHTLY SOUTHWARD AND IMPACT THE SANTA CRUZ MTNS AND SANTA
LUCIA RANGE ABOVE BIG SUR. THE HRRR AND RAP MESOSCALE/SHORT TERM
MODELS SHOW 3-4 INCHES FOR THE SANTA CRUZ MTNS WITH SOME OF THE
HRRR RUNS IN EXCESS OF 7 INCHES ABOVE BIG SUR...ALL OCCURRING OVER
THE NEXT 8-10 HOURS. WILL BE WATCHING RAIN RATES AND TRENDS
CLOSELY THE NEXT FEW HOURS FOR POSSIBLE URBAN AND SMALL STREAM
FLOOD ADVISORIES THROUGHOUT THE BAY AREA...WITH POSSIBILITY THAT
WARNINGS COULD BE NEEDED FOR THE HILLS ABOVE BIG SUR. UPSHOT IS
THAT THE COMMUTE WILL QUICKLY TURN UGLY FOR THE BAY AREA WITH
HEAVIEST RAINS FROM NOW THROUGH ROUGHLY 18-20Z. SIMILAR TO
YESTERDAYS STORM THE STEADY RAIN SHOULD END ABRUPTLY AROUND MIDDAY
IN THE BAY AREA WHILE HANGING ON LONGER FOR THE CENTRAL COAST.
SHOWERS THIS AFTERNOON BUT EVEN THOSE WILL BE LIMITED WITH SOME
LATE DAY PEAKS OF SUNSHINE. WINDS WITH TODAYS FRONT WILL BE
SOUTHERLY THIS MORNING....STRONGEST ON THE COAST AND OVER THE
OCEAN WITH GUSTS AROUND 30 MPH. WINDS TURN WEST BY MIDDAY BUT
GIVEN THE LACK OF COLD ADVECTION THE WESTERLY WINDS WONT BE TOO
STRONG.
HAVE REMOVED ALL CHANCES OF RAIN FOR THIS EVENING AS THE SYSTEM
WILL QUICKLY MOVE EASTWARD. HIGH PRESSURE BUILDS IN TONIGHT AND
LASTS THROUGH THURSDAY. AIRMASS IS MILD AND EXPECT DAYTIME HIGHS
TO BE COMFORTABLY IN THE 60S MIDWEEK WITH MILD OVERNIGHT LOWS
GENERALLY IN THE 40S.
NEXT FRONT ARRIVES THURSDAY NIGHT. INITIAL BOUNDARY DOESN`T LOOK
TOO IMPRESSIVE WITH SOUTHERLY WINDS NOT-FAVORABLE FOR OROGRAPHICS.
GFS AND ECMWF BOTH SHOW FAIRLY WEAK FRONT MOVING THROUGH TIL
MIDDAY FRIDAY...THEN COLD UPPER TROUGH SHOULD PASS OVER THE REGION
AND ALLOW FOR AN UPTICK IN RAIN SHOWERS AND INTENSITY WITH SHOWERS
LASTING INTO SATURDAY. STILL SEVERAL DAYS OUT SO THATLL BECOME THE
FOCUS AFTER TODAYS EVENT.
LATEST MODEL TREND OVER THE LAST 24 HOURS HAS BEEN TO BUILD HIGH
PRESSURE SATURDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK. IN
COORDINATION WITH WFO EUREKA REMOVED NEARLY ALL RAIN CHANCES FOR
THE NORTH BAY AS WELL AS THE REST OF THE DISTRICT AFTER SATURDAY
NIGHT.
HOWEVER MUST POINT OUT THE LONG RANGE GFS CONTINUES TO SHOW
ANOTHER COLD WEST COAST TROUGH AND ASSOCIATED RAIN ARRIVING
SOMETIME AROUND JAN 29TH WITH EXTENDED GFS AND CFS MODELS KEEPING
PATTERN ACTIVE.
&&
.AVIATION...AS OF 9:45 PM PST MONDAY...CLOUDS WILL LOWER AND
BECOMING MORE WIDESPREAD OVERNIGHT AS THE NEXT WEATHER SYSTEM
APPROACHES THE COAST. LOOK FOR MVFR CIGS AND RAIN TO SPREAD FROM
NORTH TO SOUTH BETWEEN 08Z AND 14Z. SOUTH TO SOUTHEAST WINDS WILL
ALSO INCREASE IN THIS TIME PERIOD. A PERIOD OF STRONGER
WINDS...MORE INTENSE PRECIP...AND LOWER CIGS IS LIKELY JUST AHEAD
OF THE FRONT BETWEEN 15Z AND 20Z TUESDAY. PRECIP AND WINDS WILL
TAPER OFF BY LATE TUESDAY AFTERNOON.
VICINITY OF KSFO...VFR CIGS SHOULD CONTINUE THROUGH AT LEAST
MIDNIGHT BUT THEN MVFR CIGS SHOULD DEVELOP BY 11Z WHEN PRECIP
BEGINS. FROM ABOUT 15Z TO 19Z EXPECT PRECIP TO INCREASE IN
INTENSITY...SOUTHEAST WINDS TO INCREASE...AND CIGS TO LOWER
FURTHER. FRONTAL PASSAGE EXPECTED AROUND 19Z ON TUESDAY. SHOWERS
MAY LINGER FOR A FEW HOURS AFTER FRONTAL PASSAGE THROUGH MID
AFTERNOON TUESDAY. WINDS WILL REMAIN GUSTY FROM THE SOUTHWEST BUT
GRADUALLY DECREASE BY LATE AFTERNOON.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR THROUGH LATE EVENING EXCEPT
PATCHY LIFR CONDITIONS IN FOG. THEN MVFR CIGS LIKELY DEVELOPING
BY 09Z. GIGS WILL LOWER BY 14Z TUESDAY MORNING AS PRECIP BEGINS.
EXPECT HEAVIEST PRECIP...STRONGEST SOUTHEAST WINDS...AND MOST
INTENSE PRECIP BETWEEN ABOUT 16Z AND 20Z ON TUESDAY. AFTER FRONTAL
PASSAGE EARLY TUESDAY AFTERNOON...LOOK FOR SCATTERED SHOWERS FOR A
FEW HOURS ALONG WITH GRADUALLY DECREASING SOUTHWEST WINDS.
&&
.MARINE...AS OF 02:57 AM PST TUESDAY...A STORM SYSTEM WILL MOVE
THROUGH THE AREA TODAY WITH RAIN AND BRIEF MODERATE SOUTHERLY
WINDS. WINDS WILL DECREASE RAPIDLY THIS EVENING AFTER THE STORM
PASSES. ANOTHER STORM WILL BRING INCREASING WINDS AGAIN BY FRIDAY.
A LONG PERIOD LARGE SWELL IS FORECAST TO IMPACT THE REGION LATER
THIS WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...SF BAY FROM 3 AM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 3 AM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 3 AM
SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 3 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 3 AM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 3 AM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: R_WALBRUN
AVIATION: W PI
MARINE: W PI
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AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
904 AM MST TUE JAN 19 2016
.UPDATE...
ISSUED AT 859 AM MST TUE JAN 19 2016
SOME LINGERING SNOW IN THE MOUNTAINS AND OVER THE PALMER DIVIDE
THIS MORNING...OTHERWISE HAVE DROPPED THE SNOW FM THE REST OF THE
ZONES. CONDITIONS SHOULD CONTINUE TO IMPROVE FM NORTH TO SOUTH THE
REST OF THE MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM MST TUE JAN 19 2016
COLD FRONT IS THROUGH DENVER BUT COLDEST AIR IS LAGGING BEHIND.
THERE WAS SOME RAIN INITIALLY BUT HAS TURNED OR WILL TURN TO ALL
SNOW VERY QUICKLY. HEAVIEST PRECIPITATION SEEMS TO BE QUICKLY
FOCUSING IN/NEAR THE SOUTHERN FOOTHILLS AND PALMER DIVIDE AREA
THIS MORNING. OPERATIONAL HRRR AND RAP SEEM TO BE RUNNING AN HOUR
OR TWO BEHIND CURRENT LOCATION. HOWEVER...NEW EXPERIMENTAL HRRR
SEEMS MUCH BETTER WITH THE DRYING FROM THE NORTH. THIS DRYING IS
ALREADY NOTED IN THE CHEYENNE/FORT COLLINS/GREELEY AREA AND THIS
DRIER WILL CONTINUE TO OCCUR EARLY THIS MORNING. PRECIPITATION
SHOULD BE ALL BUT GONE IN THE DENVER METRO AREA BY 7 AM...BUT
NORTHERLY ANTICYCLONIC UPSLOPE COULD KEEP SOME SNOW IN/NEAR THE
SOUTHERN FRONT RANGE FOOTHILLS/PALMER DIVIDE AS LATE AS 9-10 AM.
RADAR ECHOES HIGH ENOUGH FOR SOME 1 INCH PER HOUR RATES IN THE
HEAVIER BANDS. TRAVEL IMPACTS ARE MOST LIKELY IN THAT AREA.
MOUNTAIN SNOWFALL WILL ALSO BE DECREASING RATHER QUICKLY THIS
MORNING AS UPPER LEVEL TROUGH MOVES OUT AND RAPID DRYING OCCURS
FROM THE NORTHWEST.
BY LATER THIS MORNING INTO THE AFTERNOON CLOUDS WILL ERODE TO
THE SOUTHEAST WITH SKIES BECOMING MOSTLY SUNNY OVER MOST OF THE
FORECAST AREA. MAY HAVE A FEW CLOUDS TRAPPED IN THE MOUNTAINS BUT
PLAINS SHOULD CERTAINLY BECOME SUNNY. THAT SHOULD HELP TEMPS
BOUNCE BACK INTO THE LOWER TO MID 40S MOST OF THE LOWER ELEVATIONS
ESPECIALLY CONSIDERING RELATIVELY MILD START TO THE DAY.
FOR TONIGHT...MOSTLY CLEAR SKIES...LIGHT WINDS...AND RELATIVELY
HIGH BOUNDARY LAYER MOISTURE WILL LIKELY ALLOW AREAS OF FOG TO
FORM ON THE PLAINS JUST NORTH AND EAST OF DENVER. CLOUDS DO
INCREASE LATER TONIGHT IN ADVANCE OF NEXT SYSTEM SO THAT WOULD
TEND TO ERODE FOG LATER IN THE NIGHT AS LONG AS CLOUDS THICKEN
SUFFICIENTLY. MORE SNOW MOVES INTO THE MOUNTAINS AFTER
MIDNIGHT...WITH UP TO AN INCH OR TWO IN ZONE 31 AND RABBIT EARS
PASS AREA OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 351 AM MST TUE JAN 19 2016
THE UPCOMING WEEK WILL FEATURE A PROGRESSIVE UPPER AIR PATTERN
WITH A COUPLE WEATHER DISTURBANCES MOVING ACROSS COLORADO BETWEEN
WEDNESDAY AND MONDAY. THE FIRST DISTURBANCE WILL CROSS THE STATE
IN A COUPLE OF PIECES WEDNESDAY AND WEDNESDAY NIGHT. MOISTURE WILL
BE IN PLACE OVER THE MOUNTAINS THROUGH WEDNESDAY WITH SNOW
DEVELOPING EARLY ON. THE PLAINS WILL BE UNDER DRY...DOWNSLOPING
FLOW THROUGH WEDNESDAY...BUT IN THE EVENING...AS THE PRIMARY
TROUGH AXIS MOVES OUT OF THE MOUNTAINS...SOME SHOWER ACTIVITY MAY
DEVELOP. SNOW ACCUMULATIONS UP TO A FEW INCHES CAN BE EXPECTED IN
THE MOUNTAINS...BUT THE PLAINS SHOULD SEE LITTLE MORE THAN TRACE
AMOUNTS.
THURSDAY THROUGH SATURDAY WILL BRING A STRONG UPPER RIDGE OVER THE
STATE WITH DRY WEATHER AND WARMING TEMPERATURES. SATURDAY SHOULD
BE THE WARMEST DAY OF THE BUNCH WITH HIGHS IN THE LOWER 50S ON THE
PLAINS. ALL OF THE WARMING WILL BE IN ADVANCE OF THE NEXT UPPER
TROUGH WHICH WILL PROGRESS ACROSS THE STATE SATURDAY NIGHT AND
SUNDAY. THE ECMWF SOLUTION IS A LITTLE FASTER THAN THE LATEST RUNS
OF THE GFS...SO TIMING OF PRECIPITATION WITH THIS SYSTEM IS
DIFFICULT AT THIS TIME. THE ECMWF POINTS TO SNOW IN THE MOUNTAINS
AFTER MIDNIGHT SATURDAY NIGHT WHILE THE GFS DOESN`T BRING SNOW TO
THE MOUNTAINS UNTIL AFTER SUNRISE SUNDAY MORNING. THE UPPER TROUGH
AXIS SHOULD BE OVER EASTERN COLORADO SUNDAY AFTERNOON PRODUCING SOME
RAIN OR SNOW. THE PHASE OF PRECIPITATION IS GOING TO DEPEND ON THE
STRENGTH OF THE SURFACE COLD FRONT ASSOCIATED WITH THE UPPER
SYSTEM...AND AT THIS POINT IT DOES NOT LOOK ALL THAT STRONG.
SUBSEQUENT MODEL RUNS WILL HELP TO DEFINE THE STRENGTH AND TIMING
OF SUNDAY`S WEATHER SYSTEM. COOL AND MOIST NORTHWESTERLY FLOW
ALOFT WILL CONTINUE OVER THE STATE NEXT MONDAY WHICH SHOULD BE
ENOUGH TO KEEP SNOW SHOWERS GOING IN THE MOUNTAINS THROUGH THEN.
PLAINS LOCATIONS SHOULD BE DRIER...BUT WITH COOLER TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 859 AM MST TUE JAN 19 2016
DRIER AIR CONTINUES TO MOVE IN FROM THE NORTH...CONDITIONS SHOULD
CONTINUE TO IMPROVE THROUGH 17Z WITH VFR CONDITIONS AT ALL THE
AIRPORTS BY THIS AFTERNOON AND CLEARING SKIES. LIGHT SOUTHWEST
WINDS AT THIS TIME...WILL LIKELY TURN SOUTHEAST BY 21Z BUT
REMAINING LIGHT. ANY FOG THREAT TONIGHT WILL BE NORTH OF KDEN AND
KBJC AS LIGHT DRAINAGE WINDS ARE EXPECTED TO DEVELOP. KFNL AND
KGXY MAY SEE DENSE FOG WITH 1/4SM VSBY POSSIBLE AFTER 06Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...COOPER
SHORT TERM...BARJENBRUCH
LONG TERM...DANKERS
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
351 AM MST TUE JAN 19 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM MST TUE JAN 19 2016
COLD FRONT IS THROUGH DENVER BUT COLDEST AIR IS LAGGING BEHIND.
THERE WAS SOME RAIN INITIALLY BUT HAS TURNED OR WILL TURN TO ALL
SNOW VERY QUICKLY. HEAVIEST PRECIPITATION SEEMS TO BE QUICKLY
FOCUSING IN/NEAR THE SOUTHERN FOOTHILLS AND PALMER DIVIDE AREA
THIS MORNING. OPERATIONAL HRRR AND RAP SEEM TO BE RUNNING AN HOUR
OR TWO BEHIND CURRENT LOCATION. HOWEVER...NEW EXPERIMENTAL HRRR
SEEMS MUCH BETTER WITH THE DRYING FROM THE NORTH. THIS DRYING IS
ALREADY NOTED IN THE CHEYENNE/FORT COLLINS/GREELEY AREA AND THIS
DRIER WILL CONTINUE TO OCCUR EARLY THIS MORNING. PRECIPITATION
SHOULD BE ALL BUT GONE IN THE DENVER METRO AREA BY 7 AM...BUT
NORTHERLY ANTICYCLONIC UPSLOPE COULD KEEP SOME SNOW IN/NEAR THE
SOUTHERN FRONT RANGE FOOTHILLS/PALMER DIVIDE AS LATE AS 9-10 AM.
RADAR ECHOES HIGH ENOUGH FOR SOME 1 INCH PER HOUR RATES IN THE
HEAVIER BANDS. TRAVEL IMPACTS ARE MOST LIKELY IN THAT AREA.
MOUNTAIN SNOWFALL WILL ALSO BE DECREASING RATHER QUICKLY THIS
MORNING AS UPPER LEVEL TROUGH MOVES OUT AND RAPID DRYING OCCURS
FROM THE NORTHWEST.
BY LATER THIS MORNING INTO THE AFTERNOON CLOUDS WILL ERODE TO
THE SOUTHEAST WITH SKIES BECOMING MOSTLY SUNNY OVER MOST OF THE
FORECAST AREA. MAY HAVE A FEW CLOUDS TRAPPED IN THE MOUNTAINS BUT
PLAINS SHOULD CERTAINLY BECOME SUNNY. THAT SHOULD HELP TEMPS
BOUNCE BACK INTO THE LOWER TO MID 40S MOST OF THE LOWER ELEVATIONS
ESPECIALLY CONSIDERING RELATIVELY MILD START TO THE DAY.
FOR TONIGHT...MOSTLY CLEAR SKIES...LIGHT WINDS...AND RELATIVELY
HIGH BOUNDARY LAYER MOISTURE WILL LIKELY ALLOW AREAS OF FOG TO
FORM ON THE PLAINS JUST NORTH AND EAST OF DENVER. CLOUDS DO
INCREASE LATER TONIGHT IN ADVANCE OF NEXT SYSTEM SO THAT WOULD
TEND TO ERODE FOG LATER IN THE NIGHT AS LONG AS CLOUDS THICKEN
SUFFICIENTLY. MORE SNOW MOVES INTO THE MOUNTAINS AFTER
MIDNIGHT...WITH UP TO AN INCH OR TWO IN ZONE 31 AND RABBIT EARS
PASS AREA OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 351 AM MST TUE JAN 19 2016
THE UPCOMING WEEK WILL FEATURE A PROGRESSIVE UPPER AIR PATTERN
WITH A COUPLE WEATHER DISTURBANCES MOVING ACROSS COLORADO BETWEEN
WEDNESDAY AND MONDAY. THE FIRST DISTURBANCE WILL CROSS THE STATE
IN A COUPLE OF PIECES WEDNESDAY AND WEDNESDAY NIGHT. MOISTURE WILL
BE IN PLACE OVER THE MOUNTAINS THROUGH WEDNESDAY WITH SNOW
DEVELOPING EARLY ON. THE PLAINS WILL BE UNDER DRY...DOWNSLOPING
FLOW THROUGH WEDNESDAY...BUT IN THE EVENING...AS THE PRIMARY
TROUGH AXIS MOVES OUT OF THE MOUNTAINS...SOME SHOWER ACTIVITY MAY
DEVELOP. SNOW ACCUMULATIONS UP TO A FEW INCHES CAN BE EXPECTED IN
THE MOUNTAINS...BUT THE PLAINS SHOULD SEE LITTLE MORE THAN TRACE
AMOUNTS.
THURSDAY THROUGH SATURDAY WILL BRING A STRONG UPPER RIDGE OVER THE
STATE WITH DRY WEATHER AND WARMING TEMPERATURES. SATURDAY SHOULD
BE THE WARMEST DAY OF THE BUNCH WITH HIGHS IN THE LOWER 50S ON THE
PLAINS. ALL OF THE WARMING WILL BE IN ADVANCE OF THE NEXT UPPER
TROUGH WHICH WILL PROGRESS ACROSS THE STATE SATURDAY NIGHT AND
SUNDAY. THE ECMWF SOLUTION IS A LITTLE FASTER THAN THE LATEST RUNS
OF THE GFS...SO TIMING OF PRECIPITATION WITH THIS SYSTEM IS
DIFFICULT AT THIS TIME. THE ECMWF POINTS TO SNOW IN THE MOUNTAINS
AFTER MIDNIGHT SATURDAY NIGHT WHILE THE GFS DOESN`T BRING SNOW TO
THE MOUNTAINS UNTIL AFTER SUNRISE SUNDAY MORNING. THE UPPER TROUGH
AXIS SHOULD BE OVER EASTERN COLORADO SUNDAY AFTERNOON PRODUCING SOME
RAIN OR SNOW. THE PHASE OF PRECIPITATION IS GOING TO DEPEND ON THE
STRENGTH OF THE SURFACE COLD FRONT ASSOCIATED WITH THE UPPER
SYSTEM...AND AT THIS POINT IT DOES NOT LOOK ALL THAT STRONG.
SUBSEQUENT MODEL RUNS WILL HELP TO DEFINE THE STRENGTH AND TIMING
OF SUNDAY`S WEATHER SYSTEM. COOL AND MOIST NORTHWESTERLY FLOW
ALOFT WILL CONTINUE OVER THE STATE NEXT MONDAY WHICH SHOULD BE
ENOUGH TO KEEP SNOW SHOWERS GOING IN THE MOUNTAINS THROUGH THEN.
PLAINS LOCATIONS SHOULD BE DRIER...BUT WITH COOLER TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 351 AM MST TUE JAN 19 2016
MAIN BAND OF SNOW APPEARS TO HAVE ALREADY SHIFTED SOUTHWEST OF
KDEN SO MAINLY PERIODS OF LIGHT SNOW AND STRATUS DECK OF 800-2500
FEET EXPECTED THERE TIL AROUND 12Z-14Z. THEN THAT SHOULD ERODE AS
WELL AS DRIER AIR MOVES IN FROM THE NORTH. KAPA AND KBJC COULD SEE
SIMILAR CONDITIONS LINGER MAYBE AN HOUR OR SO LONGER...BUT OVERALL
CONDITIONS WILL RAPIDLY IMPROVE AS MUCH DRIER AIR MOVES IN BY 15Z-
17Z WITH VFR CONDITIONS AND CLEARING SKIES. NORTHERLY WINDS
BECOMING LIGHT AND VARIABLE BY 16Z-17Z AND THEN LIKELY TURNING
SOUTHEAST BY 21Z-22Z BUT REMAINING LIGHT. ANY FOG THREAT TONIGHT
WILL BE NORTH OF KDEN AND KBJC AS LIGHT DRAINAGE WINDS ARE
EXPECTED TO DEVELOP. KFNL AND KGXY MAY SEE DENSE FOG WITH 1/4SM
VSBY POSSIBLE AFTER 06Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM...DANKERS
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS MIAMI FL
1002 AM EST TUE JAN 19 2016
.UPDATE...
A CHILLY MORNING AGAIN ACROSS SOUTH FL WITH LOWS IN THE 50S IN THE
METROPOLITAN AREAS TO THE 40S ACROSS THE INTERIOR. ASIDE FROM
INCREASING CLOUD COVER ESPECIALLY SOUTHERN LOCALES, NO SIGNIFICANT
CHANGES WERE MADE TO THE FORECAST THIS MORNING. DRY AND COOL
CONDITIONS WILL PREVAIL THIS AFTERNOON. PLEASE SEE PREVIOUS
DISCUSSION BELOW FOR FURTHER FORECAST DETAILS. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 627 AM EST TUE JAN 19 2016/
AVIATION...
VFR WILL CONTINUE THROUGH THE PERIOD WITH MID TO HIGH LEVEL
BROKEN CLOUDINESS...BUT WITH NO RAIN. WINDS WILL PREVAIL OUT OF
THE N-NW NEAR 10 KT AT THE EAST COAST TERMINALS...THEN ARE FORECAST
TO BECOME N-NE LATE IN THE DAY. FOR KAPF...N-NE WINDS 5-10 KT WILL
PREVAIL THROUGH THE PERIOD. /GREGORIA
PREV DISCUSSION... /ISSUED 316 AM EST TUE JAN 19 2016/
DISCUSSION...
MODELS REMAIN IN GOOD AGREEMENT WITH HIGH PRESSURE CONTINUING TO
BUILD OVER THE SOUTHEAST UNITED STATES. THERE IS AN AREA OF HIGH
CLOUDS THAT HAS BEEN STREAMING OVER SOUTH FLORIDA SINCE YESTERDAY.
AS A 500MB TROUGH PUSHES EAST OVER THE NEXT DAY, THE HIGH CLOUDS
SHOULD ALSO BEGIN TO EXIT THE REGION. FOR THE MOST PART, DRY
WEATHER FOR THE CWA. THE EXCEPTION IS SOME SHOWER ACTIVITY WELL
OFFSHORE, OVER THE ATLANTIC. THIS LOOKS TO BE ASSOCIATED WITH A
WEAK SURFACE TROUGH. IT IS NOT ANALYZED WELL IN THE SYNOPTIC
MODELS, BUT THE HRRR IS SHOWING IT AND SEEMS TO HAVE A GOOD HANDLE
ON THINGS.
THIS WEAK TROUGH WILL GET PUSH AWAY FROM SOUTH FLORIDA AS HIGH
PRESSURE BUILDS. ALSO, THE WIND WILL FIRST BEGIN TO RELAX THROUGH
THE DAY, THEN BEGIN A TURN TO THE NORTHEAST BY WEDNESDAY MORNING.
HOWEVER, THE AIR MASS WILL REMAIN DRY AND THE WEATHER WILL
CONTINUE TO BE QUIET THROUGH THE MIDDLE OF THE WEAK. THIS AIR MASS
IS ALSO FAIRLY COOL, AND WILL KEEP THE TEMPS ACROSS THE AREA BELOW
NORMAL FOR A FEW DAYS.
AS THE HIGH BUILDS FURTHER TO THE SOUTH, THE WIND WILL TURN MORE
TO THE EAST, PRETTY MUCH BY WEDNESDAY AFTERNOON. THIS WILL BRING
SOME MOISTURE BACK TO THE AREA, AND BEGIN TO MODIFY THE
TEMPERATURES. SO, AFTER A CHILLY START WEDNESDAY MORNING, WHICH
SHOULD SEE LOWS IN THE UPPER 30S WEST OF THE LAKE, LOW 50S OVER
THE SOUTHEAST FLORIDA METRO AREAS, THE AIR MASS WILL BEGIN A
WARMING TREND. HIGHS WEDNESDAY WILL BE AROUND 70, WITH THE
NORTHWEST PORTION OF THE CWA IN THE UPPER 60S AND THE SOUTHEAST
COAST IN THE LOW 70S.
ELSEWHERE ON WEDNESDAY AFTERNOON, A LOW PRESSURE SYSTEM WILL
DEVELOP LEEWARD OF THE ROCKIES, OVER THE HIGH PLAINS. THIS LOW
WILL BE OUR NEXT WEATHER MAKER FOR SOUTH FLORIDA. BY THURSDAY
AFTERNOON, WHICH WILL BE WARMER THAN WEDNESDAY, BUT STILL LOOKS
DRY, THE LOW WILL TRACK INTO THE SOUTHERN MISSISSIPPI VALLEY, BUT
REMAIN NORTH OF THE GULF. THIS WILL BEGIN TO TURN THE WIND MORE TO
THE SOUTH BY FRIDAY MORNING. THIS WILL BRING MOISTURE BACK, AS
WELL AS ALLOW THE AIR MASS TO WARM INTO THE MID TO UPPER 70S. THIS
WILL ALSO BRING OUR NEXT CHANCE FOR SHOWERS AND STORMS FROM
THURSDAY NIGHT, THROUGH FRIDAY, AND EVEN SOME REMNANT SHOWER
ACTIVITY FRIDAY NIGHT INTO SATURDAY MORNING.
FOR THIS NEXT SYSTEM, IT DOES TRACK FURTHER NORTH THAN THE SYSTEM
THIS PAST SUNDAY MORNING. ALSO, MODELS ARE INDICATING THAT THERE
SHOULD BE SHOWER ACTIVITY WELL AHEAD OF THE SYSTEM. THIS COULD
POTENTIALLY REDUCE INSTABILITY AHEAD OF THE COLD FRONT. THE GFS IS
NOT TOO EXCITED ABOUT THE AMOUNT OF CAPE BY FRIDAY MORNING, WITH
ONLY A FEW HUNDRED JOULES FRIDAY AFTERNOON. THERE IS A BROAD JET
STREAK WITH THE RIGHT EXIT QUADRANT IN THE VICINITY, LEADING TO
SOME CONVERGENCE ALOFT IN THIS GENERAL AREA. THE GFS DOES SHOW A
WEAK LOW LEVEL JET AT 850 MB AT ABOUT 40 KTS.SO, THE ELEMENTS JUST
DO NOT LOOK AS THOUGH THEY ARE LINING UP AS THEY DID WITH THE
LATEST SYSTEM. GFS SHOWS THE HELICITY TO BE A MAX OF 100 M^2*S^-2,
JUST AHEAD OF THE FRONT, NOTHING COMPARED TO THE 300-400 VALUES
FROM THE OTHER DAY. STILL, THERE COULD BE SHOWERS AND A FEW
THUNDERSTORMS THAT PRODUCE SOME GUSTY WIND AS THE FRONT PUSHES
THROUGH ON FRIDAY. THERE WILL BE A CONCERN ABOUT THE SUSTAINED,
NON-CONVECTIVE WIND FROM FRIDAY NIGHT THROUGH SATURDAY. MODEL
BLENDS ARE SHOWING WIND OVER THE MARINE AREAS TO BE NEARING 30KTS,
WITH HIGHER GUSTS, AND 15 TO 20 KTS OVER THE MAINLAND. THIS WILL
MEAN THERE WILL BE SOME MARINE CONCERNS FOR THIS PERIOD.
BEHIND THIS FRONT, ANOTHER COOLER AIR MASS WILL SETTLE IN OVER THE
CWA FOR THE REMAINDER OF THE WEEKEND, INTO THE BEGINNING OF NEXT
WEEK, WHICH SHOULD SEE QUIET WEATHER CONDITIONS.
AVIATION...
HIGH PRESSURE IS BUILDING OVER SOUTH FLORIDA. THIS WILL KEEP THE
WEATHER QUIET FOR THE TAF SITES, AS WELL AS VFR CONDITIONS THROUGH
THE TAF PERIOD. EVEN SO, THERE ARE SOME MID AND UPPER LEVEL CLOUDS
THAT ARE GIVING CIGS OF BKN045, AS WELL AS A DECK OF HIGH CLOUDS.
THE WIND WILL CONTINUE OUT OF THE NORTH TO NORTHWEST INTO THE
AFTERNOON, BEFORE TRYING TO TURN TO THE NORTHEAST.
MARINE...
MARINE CONDITIONS ARE HAZARDOUS FOR SMALL CRAFT TODAY. THIS IS DUE
TO A NORTHERLY WIND BETWEEN 15 AND 20 KTS OPPOSING THE GULF
STREAM, CAUSING SEAS OF 7 TO 8 FEET IN THE GULF STREAM. THE WIND
IS FORECAST TO SUBSIDE TONIGHT, WHICH WILL ALLOW SEAS TO SLOWLY
SUBSIDE BY TOMORROW MORNING. THERE IS A SMALL CRAFT ADVISORY OUT
FOR THE ATLANTIC WATERS. THERE IS ALSO AN AREA OF SHOWERS ORIENTED
NORTH SOUTH IN THE OFFSHORE ATLANTIC WATERS THAT SHOULD SLOWLY
SUBSIDE THIS MORNING. A COLD FRONT AT THE END OF THE WEEK WILL
BRING MARINE CONCERNS INTO THE FORECAST ONCE AGAIN. BESIDES
SHOWERS AND THUNDERSTORMS THAT WILL ACCOMPANY A COLD FRONT, THE
SUSTAINED WIND BEHIND THE FRONT FOR FRIDAY NIGHT INTO SATURDAY
WILL BE NEARING 30 KTS. THIS WILL MAKE FOR HAZARDOUS MARINE
CONDITIONS THIS WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 65 53 71 56 / 0 10 10 10
FORT LAUDERDALE 67 54 71 60 / 0 10 0 10
MIAMI 66 55 70 60 / 0 10 0 10
NAPLES 65 43 72 53 / 0 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR AMZ650-651-670-
671.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR GMZ656-
657.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR GMZ676.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
627 AM EST TUE JAN 19 2016
.AVIATION...
VFR WILL CONTINUE THROUGH THE PERIOD WITH MID TO HIGH LEVEL
BROKEN CLOUDINESS...BUT WITH NO RAIN. WINDS WILL PREVAIL OUT OF
THE N-NW NEAR 10 KT AT THE EAST COAST TERMINALS...THEN ARE FORECAST
TO BECOME N-NE LATE IN THE DAY. FOR KAPF...N-NE WINDS 5-10 KT WILL
PREVAIL THROUGH THE PERIOD. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 316 AM EST TUE JAN 19 2016/
DISCUSSION...
MODELS REMAIN IN GOOD AGREEMENT WITH HIGH PRESSURE CONTINUING TO
BUILD OVER THE SOUTHEAST UNITED STATES. THERE IS AN AREA OF HIGH
CLOUDS THAT HAS BEEN STREAMING OVER SOUTH FLORIDA SINCE YESTERDAY.
AS A 500MB TROUGH PUSHES EAST OVER THE NEXT DAY, THE HIGH CLOUDS
SHOULD ALSO BEGIN TO EXIT THE REGION. FOR THE MOST PART, DRY
WEATHER FOR THE CWA. THE EXCEPTION IS SOME SHOWER ACTIVITY WELL
OFFSHORE, OVER THE ATLANTIC. THIS LOOKS TO BE ASSOCIATED WITH A
WEAK SURFACE TROUGH. IT IS NOT ANALYZED WELL IN THE SYNOPTIC
MODELS, BUT THE HRRR IS SHOWING IT AND SEEMS TO HAVE A GOOD HANDLE
ON THINGS.
THIS WEAK TROUGH WILL GET PUSH AWAY FROM SOUTH FLORIDA AS HIGH
PRESSURE BUILDS. ALSO, THE WIND WILL FIRST BEGIN TO RELAX THROUGH
THE DAY, THEN BEGIN A TURN TO THE NORTHEAST BY WEDNESDAY MORNING.
HOWEVER, THE AIR MASS WILL REMAIN DRY AND THE WEATHER WILL
CONTINUE TO BE QUIET THROUGH THE MIDDLE OF THE WEAK. THIS AIR MASS
IS ALSO FAIRLY COOL, AND WILL KEEP THE TEMPS ACROSS THE AREA BELOW
NORMAL FOR A FEW DAYS.
AS THE HIGH BUILDS FURTHER TO THE SOUTH, THE WIND WILL TURN MORE
TO THE EAST, PRETTY MUCH BY WEDNESDAY AFTERNOON. THIS WILL BRING
SOME MOISTURE BACK TO THE AREA, AND BEGIN TO MODIFY THE
TEMPERATURES. SO, AFTER A CHILLY START WEDNESDAY MORNING, WHICH
SHOULD SEE LOWS IN THE UPPER 30S WEST OF THE LAKE, LOW 50S OVER
THE SOUTHEAST FLORIDA METRO AREAS, THE AIR MASS WILL BEGIN A
WARMING TREND. HIGHS WEDNESDAY WILL BE AROUND 70, WITH THE
NORTHWEST PORTION OF THE CWA IN THE UPPER 60S AND THE SOUTHEAST
COAST IN THE LOW 70S.
ELSEWHERE ON WEDNESDAY AFTERNOON, A LOW PRESSURE SYSTEM WILL
DEVELOP LEEWARD OF THE ROCKIES, OVER THE HIGH PLAINS. THIS LOW
WILL BE OUR NEXT WEATHER MAKER FOR SOUTH FLORIDA. BY THURSDAY
AFTERNOON, WHICH WILL BE WARMER THAN WEDNESDAY, BUT STILL LOOKS
DRY, THE LOW WILL TRACK INTO THE SOUTHERN MISSISSIPPI VALLEY, BUT
REMAIN NORTH OF THE GULF. THIS WILL BEGIN TO TURN THE WIND MORE TO
THE SOUTH BY FRIDAY MORNING. THIS WILL BRING MOISTURE BACK, AS
WELL AS ALLOW THE AIR MASS TO WARM INTO THE MID TO UPPER 70S. THIS
WILL ALSO BRING OUR NEXT CHANCE FOR SHOWERS AND STORMS FROM
THURSDAY NIGHT, THROUGH FRIDAY, AND EVEN SOME REMNANT SHOWER
ACTIVITY FRIDAY NIGHT INTO SATURDAY MORNING.
FOR THIS NEXT SYSTEM, IT DOES TRACK FURTHER NORTH THAN THE SYSTEM
THIS PAST SUNDAY MORNING. ALSO, MODELS ARE INDICATING THAT THERE
SHOULD BE SHOWER ACTIVITY WELL AHEAD OF THE SYSTEM. THIS COULD
POTENTIALLY REDUCE INSTABILITY AHEAD OF THE COLD FRONT. THE GFS IS
NOT TOO EXCITED ABOUT THE AMOUNT OF CAPE BY FRIDAY MORNING, WITH
ONLY A FEW HUNDRED JOULES FRIDAY AFTERNOON. THERE IS A BROAD JET
STREAK WITH THE RIGHT EXIT QUADRANT IN THE VICINITY, LEADING TO
SOME CONVERGENCE ALOFT IN THIS GENERAL AREA. THE GFS DOES SHOW A
WEAK LOW LEVEL JET AT 850 MB AT ABOUT 40 KTS.SO, THE ELEMENTS JUST
DO NOT LOOK AS THOUGH THEY ARE LINING UP AS THEY DID WITH THE
LATEST SYSTEM. GFS SHOWS THE HELICITY TO BE A MAX OF 100 M^2*S^-2,
JUST AHEAD OF THE FRONT, NOTHING COMPARED TO THE 300-400 VALUES
FROM THE OTHER DAY. STILL, THERE COULD BE SHOWERS AND A FEW
THUNDERSTORMS THAT PRODUCE SOME GUSTY WIND AS THE FRONT PUSHES
THROUGH ON FRIDAY. THERE WILL BE A CONCERN ABOUT THE SUSTAINED,
NON-CONVECTIVE WIND FROM FRIDAY NIGHT THROUGH SATURDAY. MODEL
BLENDS ARE SHOWING WIND OVER THE MARINE AREAS TO BE NEARING 30KTS,
WITH HIGHER GUSTS, AND 15 TO 20 KTS OVER THE MAINLAND. THIS WILL
MEAN THERE WILL BE SOME MARINE CONCERNS FOR THIS PERIOD.
BEHIND THIS FRONT, ANOTHER COOLER AIR MASS WILL SETTLE IN OVER THE
CWA FOR THE REMAINDER OF THE WEEKEND, INTO THE BEGINNING OF NEXT
WEEK, WHICH SHOULD SEE QUIET WEATHER CONDITIONS.
AVIATION...
HIGH PRESSURE IS BUILDING OVER SOUTH FLORIDA. THIS WILL KEEP THE
WEATHER QUIET FOR THE TAF SITES, AS WELL AS VFR CONDITIONS THROUGH
THE TAF PERIOD. EVEN SO, THERE ARE SOME MID AND UPPER LEVEL CLOUDS
THAT ARE GIVING CIGS OF BKN045, AS WELL AS A DECK OF HIGH CLOUDS.
THE WIND WILL CONTINUE OUT OF THE NORTH TO NORTHWEST INTO THE
AFTERNOON, BEFORE TRYING TO TURN TO THE NORTHEAST.
MARINE...
MARINE CONDITIONS ARE HAZARDOUS FOR SMALL CRAFT TODAY. THIS IS DUE
TO A NORTHERLY WIND BETWEEN 15 AND 20 KTS OPPOSING THE GULF
STREAM, CAUSING SEAS OF 7 TO 8 FEET IN THE GULF STREAM. THE WIND
IS FORECAST TO SUBSIDE TONIGHT, WHICH WILL ALLOW SEAS TO SLOWLY
SUBSIDE BY TOMORROW MORNING. THERE IS A SMALL CRAFT ADVISORY OUT
FOR THE ATLANTIC WATERS. THERE IS ALSO AN AREA OF SHOWERS ORIENTED
NORTH SOUTH IN THE OFFSHORE ATLANTIC WATERS THAT SHOULD SLOWLY
SUBSIDE THIS MORNING. A COLD FRONT AT THE END OF THE WEEK WILL
BRING MARINE CONCERNS INTO THE FORECAST ONCE AGAIN. BESIDES
SHOWERS AND THUNDERSTORMS THAT WILL ACCOMPANY A COLD FRONT, THE
SUSTAINED WIND BEHIND THE FRONT FOR FRIDAY NIGHT INTO SATURDAY
WILL BE NEARING 30 KTS. THIS WILL MAKE FOR HAZARDOUS MARINE
CONDITIONS THIS WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 65 53 71 56 / 0 10 10 10
FORT LAUDERDALE 67 54 71 60 / 0 10 0 10
MIAMI 66 55 70 60 / 0 10 0 10
NAPLES 65 43 72 53 / 0 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR AMZ650-651-670-
671.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR GMZ656-
657.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR GMZ676.
&&
$$
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
240 AM PST TUE JAN 19 2016
.SYNOPSIS...ANOTHER STORM SYSTEM WILL MOVE INTO THE REGION TODAY
BRINGING AREAS OF CLOUDS AND LOCALLY GUSTY WINDS. PRECIPITATION
CHANCES WILL MAINLY BE CONFINED TO THE SIERRA AND HIGHER ELEVATIONS
OF THE SOUTHERN GREAT BASIN. AFTER TODAY HIGH PRESSURE WILL BUILD
OVER THE REGION BRINGING DRY CONDITIONS AND ABOVE NORMAL
TEMPERATURES THROUGH THE END OF THE WEEK.
&&
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT.
AS ONE SYSTEM EXITS THE REGION ANOTHER IS ALREADY STARTING TO MOVE
IN. HIGH CLOUDS WILL CONTINUE TO SPREAD OVER THE FORECAST AREA TODAY
AND WILL EVENTUALLY LOWER THROUGHOUT THE DAY. LIKE THE PREVIOUS
COUPLE OF SYSTEMS MUCH OF THE PRECIPITATION IS EXPECTED TO BE
INTERCEPTED BY THE SIERRA. HOWEVER...THIS SYSTEM MAY TAKE A TRACK
THAT WILL BRING IT A BIT FURTHER SOUTH ALLOWING FOR MORE
PRECIPITATION TO MAKE IT EAST OF THE SIERRA. THE LATEST MODEL RUNS
HAVE BEEN PROGRESSIVELY SHOWING HIGHER QPF AMOUNTS ACROSS CENTRAL
INYO...SAN BERNARDINO AND SOUTHERN NEVADA THROUGH 00Z THIS
AFTERNOON. EVEN THE LATEST HRRR HAS BEEN RAMPING UP ITS
PRECIPITATION COVERAGE WHICH SHOWS THE GREATEST POTENTIAL FOR
SHOWERS ACROSS THOSE AREAS BETWEEN 19Z-00Z. BASED ON THE LATEST RUNS
HAVE GONE AHEAD AND INCREASED POPS IN THE GRIDS. STILL THINK THAT
ANYTHING THAT DOES OCCUR EAST OF THE SIERRA WILL REMAIN LIGHT AND
AMOUNTS SHOULD GENERALLY RANGE FROM A TRACE TO A COUPLE OF
HUNDREDTHS WITH LIGHT SNOW ACCUMULATIONS IN THE HIGHER ELEVATIONS.
SHOWERS WILL THEN SPREAD EAST THIS EVENING WITH LIGHT AMOUNTS
EXPECTED ACROSS NORTHERN MOHAVE COUNTY BEFORE EXITING THE CWA
OVERNIGHT. WITH THE CLOUD COVER TODAY TEMPERATURES WILL BE HELD DOWN
SEVERAL DEGREES FROM YESTERDAY WITH READINGS CLOSE TO NORMAL.
HIGH PRESSURE IS THEN FORECAST TO DEVELOP OVER THE REGION WEDNESDAY
AND THURSDAY ALLOWING FOR DRY CONDITIONS AND TEMPERATURES WARMING TO
A FEW DEGREES ABOVE NORMAL. IT DOES LOOK LIKE THERE WILL BE ENOUGH
OF A SURFACE GRADIENT TO BRING GUSTY WINDS DOWN THE COLORADO RIVER
VALLEY WEDNESDAY NIGHT AND THURSDAY. AT THIS TIME WINDS DO NOT LOOK
TO BE STRONG ENOUGH FOR ANY ADVISORIES...BUT WINDS COULD STILL GUST
OVER 30 MPH...ESPECIALLY NEAR LAUGHLIN/BULLHEAD CITY.
.LONG TERM...FRIDAY THROUGH TUESDAY.
NOT MUCH CHANGE AGAIN TO THE LONG TERM PORTION OF THE FORECAST
TONIGHT. WE START WITH SHORTWAVE RIDGING MOVING OFF TO THE EAST IN
ADVANCE OF THE NEXT SYSTEM MOVING ONTO THE WEST COAST SOME TIME
BETWEEN 00Z AND 18Z SATURDAY BASED ON THE MODEL OF CHOICE. I AM
LEANING MORE WITH THE 00Z ECMWF TIMING (CLOSER TO 12Z-18Z SATURDAY)
GIVEN THE CLEAR TREND IN THE GFS TOWARD STRONGER RIDGING DOWNSTREAM
OF THE SYSTEM IN THE PAST 24 HOURS...SOMETHING THE ECMWF HAS BEEN
QUITE CONSISTENT ABOUT THE PAST FEW CYCLES. IN ADDITION, I AM
LEANING TOWARD THE SOMEWHAT DEEPER DEPICTION OF THE TROUGH OF THE
ECMWF COMPARED TO THE 00Z GFS...DESPITE CONSIDERABLE SUPPORT FROM
THE 00Z CMC/NAM FOR THE GFS SOLUTION. ENSEMBLE SOLUTIONS ARE
CONSIDERABLY MORE VARIED, AND AT LEAST A FEW MEMBERS SUGGEST THE
DEEPER/SLOWER APPEARANCE TO THE SYSTEM THE EURO HAS CONSISTENTLY
PROVIDED. ENSEMBLE MEANS ARE SOMEWHAT SLOWER THAN THE 00Z GFS
DETERMINISTIC SOLUTION AND THE RECENT 06Z RUN IS SLOWER/DEEPER THAN
ITS PREDECESSOR, PROVIDING ADDITIONAL SUPPORTING EVIDENCE FOR ME TO
LEAN ON THE SLOWER SIDE. GFS TENDS TO PROGRESS SYSTEMS INTO RIDGES
TOO QUICKLY, AND I SUSPECT THIS BIAS IS SHOWING UP TO SOME DEGREE.
NEVERTHELESS, FINAL GRIDS INCLUDED AT LEAST SOME CONTRIBUTION FROM
THE GFS BECAUSE OF SUBSTANTIALLY MORE SUPPORT FROM OTHER MODELS AND
FROM THE APPARENT SEASONAL BIAS OF THE ECMWF TO BE A BIT TOO
STRONG/SLOW WITH THESE PACIFIC SYSTEMS.
MODELS HAVE ALSO BEEN A LITTLE BIT MORE RELUCTANT TO START PRECIP IN
THE SIERRA DURING THE MORNING FRIDAY...SO I REDUCED POPS DURING THIS
TIME. CURRENTLY...ONSET TIMING SEEMS TO BE FRIDAY AFTERNOON/EVENING.
GFS/CMC SHUT DOWN PRECIP IN THE SIERRA QUICKLY...BY 12Z-18Z
SATURDAY...GIVEN THE FASTER/WEAKER DEPICTIONS OF TROUGH PASSAGE.
EURO KEEPS PRECIP AROUND THROUGH 00Z SUNDAY. I MAINTAINED POPS IN
THE SIERRA THROUGH THIS TIME...THOUGH THEY REMAIN IN THE SLIGHT
CHANCE CATEGORY BY THIS POINT. IF THE EURO SOLUTION VERIFIES...COULD
SEE SNOW AMOUNTS OF 6-12 INCHES ALONG THE SIERRA CREST. KEPT THEM A
BIT LOWER THAN THIS FOR NOW GIVEN THE MODEL UNCERTAINTY.
PRECIP FOR THE SOUTHERN GREAT BASIN IS FAR MORE UNCERTAIN AS THE
FARTHER NORTH TRACK OF THE GFS PROVIDES LITTLE TO NO PRECIP IN THIS
REGION WHEREAS THE ECMWF AND TO A LESSER DEGREE THE CMC PROVIDE AT
LEAST LIGHT ISOLATED/SCATTERED PRECIP THROUGH THE DAY SATURDAY. EURO
TENDS TO BE TOO AGGRESSIVE WITH PRODUCING PRECIP IN THIS AREA...AND
GIVEN THAT THE SIERRA WILL TAKE THE BRUNT OF THE PRECIP...KEPT VERY
LOW POPS IN FOR THIS REGION SATURDAY. TEMPERATURES FRIDAY AND
SATURDAY WILL BE ABOUT 2-7 DEGREES ABOVE NORMAL.
LONG-RANGE MODELS SHOW AT LEAST SOME INDICATION OF WEAK VORTICITY
MAXIMA MOVING THROUGH THE SOUTHWEST UPSTREAM OF THE SYSTEM PASSING
THROUGH ON SATURDAY. NO MATTER THE DEPICTION...LOOKS LIKE SUNDAY
WILL BE MOSTLY DRY AND COOLER AS NORTHERLY UPPER-LEVEL FLOW BECOMES
ESTABLISHED. AS THE TROUGH DEEPENS TO OUR EAST SUNDAY AND
MONDAY...HIGH AMPLITUDE RIDGING DEVELOPS ALONG THE WEST
COAST...PROVIDING OUR AREA STRONG NORTHERLY FLOW ALOFT FOR MONDAY
AND TUESDAY. THIS WILL LIKELY TRANSLATE TO BREEZY CONDITIONS IN THE
COLORADO RIVER VALLEY DURING THIS TIME. OTHERWISE...DRY CONDITIONS
AND NEAR NORMAL TEMPERATURES SHOULD START OUT THE NEW WEEK.
NEAR THE END OF THE LONG TERM...EURO FLATTENS THE NEWLY ESTABLISHED
RIDGE FAR MORE AGGRESSIVELY THAN THE GFS AS THE NEXT SYSTEM
APPROACHES THE WEST COAST. NEVERTHELESS...THE STORM TRACK REMAINS
TOO FAR NORTH AND THE SUBTROPICAL RIDGE IN THE EAST PACIFIC REMAINS
TOO STRONG TO PERMIT THIS SYSTEM TO AFFECT OUR AREA TO A SUBSTANTIAL
DEGREE. BEYOND THE LONG RANGE...ENSEMBLE SOLUTIONS HAVE CONSISTENTLY
INSISTED THAT THE SUBTROPICAL RIDGE IN THE EAST PACIFIC WILL
RETROGRESS AS FEBRUARY APPROACHES. IF SO...THIS WOULD AT LEAST
SUGGEST THAT MORE UNSETTLED WEATHER IS ON THE HORIZON. WE SHALL SEE.
&&
.AVIATION...FOR MCCARRAN...WINDS WILL GENERALLY REMAIN LIGHT AND
VARIABLE AT THE TERMINAL TODAY WINDS WIND SPEEDS REMAINING BELOW
6KTS THROUGH THE DAY. HIGH CLOUDS WILL GRADUALLY LOWER THIS MORNING
WITH CIGS AROUND 10K FEET BETWEEN 19Z-00Z THIS AFTERNOON. SCATTERED
SHOWERS ARE EXPECTED TO DEVELOP IN THE SPRING MOUNTAINS AND THERE IS
A SLIGHT CHANCE SHOWERS COULD WORK INTO THE VALLEY BETWEEN 20Z-00Z.
ANY PRECIPITATION THAT DOES FALL IS EXPECTED TO REMAIN LIGHT AND
CHANCES ARE TOO LOW TO INCLUDE IN THE TAF.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SOUTH WINDS WILL INCREASE MAINLY ACROSS
INYO...ESMERALDA...AND LINCOLN COUNTIES THIS AFTERNOON AROUND 10-15
KTS WITH WINDS LESS THAN 10KTS ELSEWHERE...EXCEPT WESTERN SAN
BERNARDINO COUNTY WHERE WEST WINDS 10-20KTS WILL OCCUR.
PRECIPITATION IS LIKELY ACROSS THE SIERRA CREST...BUT ISOLATED TO
SCATTERED SHOWERS ARE FORECAST TO DEVELOP EAST OF THE CREST ACROSS
THE REMAINDER OF THE AREA THIS AFTERNOON. CIGS RANGING FROM 8-10K
FEET. PRECIPITATION AMOUNTS ARE EXPECTED TO REMAIN LIGHT.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED.
PLEASE REPORT ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
$$
SHORT TERM/AVIATION...GORELOW
LONG TERM.............SHAFER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
919 AM EST TUE JAN 19 2016
.SYNOPSIS...
COLD CONTINUES TODAY AND TONIGHT UNDER HIGH PRESSURE AND LIGHTER WINDS.
WEAKENING SYSTEM WEDNESDAY COULD LEAVE MINOR SNOW ACCUMULATIONS. A
MAJOR WINTER STORM DEVELOPS THURSDAY NIGHT AND LINGERS INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
CLOUDS SLOW TO ERODE...BUT ARE IN FACT DOING SO AT THIS HOUR...AND
SHOULD BE CLEARING AS WE HEAD INTO THE AFTERNOON HOURS TODAY. SENT
SOME REVAMPED SKY COVER GRIDS...AND WILL KEEP THE FLURRIES OUT AS
OBSERVATIONS WITH SNOW/FLURRIES ARE COMING FEW AND FAR BETWEEN.
PREVIOUS DISCUSSION BELOW...
PESKY STRATOCU HOLDING STRONG IN THE MOUNTAINS WITH SCT FLURRIES
OR ICE CRYSTALS FALLING. OUTSIDE OF THAT...A PASSING S/W TROF MAY
BRING SOME CLOUDS INTO THE AREA THRU MORNING...ESPECIALLY ACROSS
NE KY/S WV/ AND SW VA WHERE A PASSING FLURRY CANNOT BE RULED OUT.
HIGH PRESSURE BUILDS INTO THE REGION TODAY WHICH WILL FURTHER
DIMINISH THE WIND. STILL COULD SEE SOME GUSTS IN THE N MOUNTAINS
THOUGH. HI RES MODELS TRYING TO SHOW SOME AFTERNOON STREAKY STRATOCU
DEVELOPING OVER SE OH AND N WV AGAIN TODAY. BUMPED SKY COVER UP A
BIT THERE BUT NOT TO THE DEGREE THE HRRR WOULD SUGGEST. TEMPS TODAY
SHOULD RECOVER ABOUT 5 DEGREES FROM YESTERDAY BUT STILL COLD
OVERALL.
WITH HIGH PRESSURE OVERHEAD TONIGHT...EXPECTING A QUICK FALL IN
TEMPS THIS EVENING...ESPECIALLY OVER AREAS THAT HAVE SNOW ON THE
GROUND. HOWEVER...MID AND HI CLOUDS WILL BE ADVANCING TOWARD THE
AREA LATE WHICH WILL CAP THE FREE FALL. WAA ALOFT WILL ALSO COMMENCE
WHICH SHOULD ALLOW THE HIGHER ELEVATIONS TO SEE A SLOW RISE
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
THE WEAKENING SUPPORT/LIFT ON WEDNESDAY WILL WORK HARD TO SATURATE THE COLUMN
IN THE INITIALLY DRY ARCTIC AIR.
FEATURE IS A COMBO OF A 500 MB TROF AND WARM AIR ADVECTION IN THE LOW LEVELS.
FOR EXAMPLE...THE 850 MB FLOW OF 30 TO 40 KNOTS IS PERPENDICULAR TO THE
850 MB ISOTHERMS VCNTY STL TUESDAY EVENING. BY 18Z WEDNESDAY...THE FLOW
IS ALMOST PARALLEL TO THE ISOTHERMS. NOT MUCH CHANGE TO OUR 1 TO 2 INCH
FORECAST...BUT DID TRY TO DAMPEN THE NORTHERN COUNTIES...INCLUDING THE
ROUTE 50 CORRIDOR TO MOSTLY AN INCH OR LESS OF SNOW ACCUMULATION ON
WEDNESDAY.
MEANWHILE...TRIED TO BOOST PORTIONS OF NORTHEAST KENTUCKY...THE SOUTHERN
COAL FIELDS OF WEST VIRGINIA...BUCHANAN AND DICKENSON COUNTIES IN VIRGINIA
MORE TOWARD THE 2 INCH ACCUMULATION. IF SYSTEM DOES NOT DAMPEN QUICKER
THAN EXPECTED...WINTER WX ADVISORIES WILL LIKELY BE POSTED IN SOME COUNTIES
THAT HAVE THE 2 INCH CRITERIA...WHICH IS THE SAME THEME AS YESTERDAY.
WILL CUT BACK ON HIGH TEMPERATURES IN THE SOUTHWEST ON WEDNESDAY...WHERE
THE SNOW WILL LIKELY REACH THE GROUND IN THE MORNING.
WEDNESDAY SYSTEM LEAVES THE LOW ELEVATIONS SATURATED...COULD NOT COMPLETELY
RULE OUT SOME FREEZING DRIZZLE IN THE MOUNTAINS OR SOUTHERN COUNTIES OVERNIGHT
WEDNESDAY NIGHT IN THE WAKE OF THE SYNOPTIC LIGHT SNOW. YET...WILL NOT INSERT
YET INTO THE FORECAST. NORTHERN COUNTIES HAVE A BETTER CHANCE OF THE
LOWER CLOUDS BREAKING UP BEFORE DAWN THURSDAY.
WILL SLOW DOWN THE INCREASING POPS LATE THURSDAY IN THE EXTREME SOUTH A
FEW HOURS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ON THE MIDNIGHT SHIFT THIS TUESDAY MORNING...NO REASON TO MAKE MAJOR CHANGES
TO OUR GRIDS FOR THE MAJOR STORM. AS WE KNOW...MAJOR ADJUSTMENTS ARE WISER
AS WE GET CLOSER...INSTEAD OF SEESAWING DAYS AWAY.
WITH THE MID LEVEL AND 850 MB LOW STILL TO OUR WEST ON FRIDAY...AND A STRONG
SOUTHERLY 40 KNOT 850 MB FLOW INTO SOUTHERN WEST VIRGINIA...WE STILL LIKE
THE FORECAST RAIN WORKING NORTH OVERNIGHT THURSDAY NIGHT INTO FRIDAY
FOR SOUTHERN COUNTIES. WILL NOT ADD A WATER HAZARD AS OF YET...BUT
AGAIN...EVEN THAT COULD NOT BE COMPLETELY RULED OUT FOR SOUTHERN
COUNTIES.
HOW FAR AND QUICKLY THAT WINTRY MIX WORKS NORTH...IS THE QUESTION.
WITH SOME SE COMPONENT THOUGH IN POCAHONTAS COUNTY...WE STILL LIKE
KEEPING MOSTLY SNOW IN POCAHONTAS COUNTY.
00Z ECMWF STILL A BIT FURTHER SOUTH WITH THE MID LEVEL AND 850 MB LOW
CIRCULATION...AND THUS A BIT COLDER AT CRITICAL 850 MB LEVEL.
DID INCREASE POPS FRIDAY NIGHT INTO SATURDAY MORNING IN THE STRONG WRAP
AROUND FROM THE DEEPENING STORM TO OUR EAST.
REST OF THIS LONG TERM IS FROM OUR LATE MONDAY PACKAGE...
MODELS AGREE ON THE POTENTIAL FOR A MAJOR WINTER WEATHER SYSTEM
IMPACTING THE AREA EARLY IN THE PERIOD.
A MIDSTREAM UPPER LEVEL S/W TROUGH DIGS SEWD THROUGH THE SRN
PLAINS STATES THU...TOWARD A L/W TROUGH POSITION E OF THE
MISSISSIPPI RIVER...WITH A RIDGE BUILDING TO ITS W. THE S/W
TROUGH CLOSES OFF FRI...TRACKS ACROSS THE SRN APPALACHIANS FRI
NT...AND THEN MEANDERS UP ALONG THE ERN SEABOARD ON SAT.
THE INITIAL SFC LOW CENTER TRACKS NEWD INTO SE KY AND SW VA THU
EVENING...WITH THE INVERTED LOW LEVEL TROUGH EXTENDING NWD UP
ALONG THE OHIO RIVER...PEAKING THE WARM WEDGE EFFECT AT THAT TIME.
THAT CENTER THEN FILLS OVERNIGHT AS THE NEW LOW CENTER GETS GOING
ALONG THE EASTERN SEABOARD. THAT CENTER SLOWLY MEANDERS UP THE
EASTERN SEABOARD SAT AND SAT NT...BEFORE FINALLY PULLING OUT TO
SEA ON SUNDAY.
THIS SCENARIO IS LIKELY TO RESULT IN SNOW OVERSPREADING THE AREA
FROM S TO N THU NT...WITH A TRANSITION TO SLEET AND THEN RAIN
INTO CENTRAL PORTIONS OF THE FCST AREA FROM THE S. FREEZING RAIN
IS ALSO POSSIBLE IN THE TRANSITION. THE HIGHEST LOW LEVEL
TEMPERATURES WILL OCCUR IN THE WARM WEDGE BETWEEN THE OHIO RIVER
AND THE WV MOUNTAINS. SFC TEMPERATURES SHOULD PEAK MID TO LATE
AFTERNOON FRI...BUT THE WARM WEDGE ALOFT STARTS PUSHING EWD LATE
FRI AFTERNOON. THIS COMBINATION KEEPS THE FREEZING RAIN POTENTIAL
IN THE MORNING AND MIDDAY FRI...MAINLY FOR SRN PORTIONS OF THE
AREA AND ALONG THE ERN SLOPES OF THE SRN WV MOUNTAINS.
ACCUMULATIONS THU NT AS LIKELY TO BE LIMITED OVER THE SRN COAL
FIELDS OF WV ON ACCOUNT OF SFC TEMPERATURES THERE GETTING ABOVE
FREEZING SOON AFTER THE ONSET OF THE PRECIPITATION. AN INCH OR
TWO ARE POSSIBLE ELSEWHERE BY DAWN FRI...DEPENDING UPON HOW
QUICKLY SLEET MIXES IN RELATIVE TO THE ONSET TIME OF THE
PRECIPITATION. THE CENTRAL MOUNTAINS APPEAR MOST LIKELY TO GET
SEVERAL INCHES BY DAWN FRI AS THAT IS WHERE THERE IS LIKELY TO BE
THE MOST TIME BETWEEN THE ONSET OF THE PRECIPITATION AND THE
ARRIVAL OF ABOVE FREEZING TEMPERATURES ALOFT.
AS THE UPPER LEVEL LOW ROLLS S OF THE AREA FRI NT...THE LOW LEVEL
INVERTED TROUGH AND WARM WEDGE COLLAPSE...AND TEMPERATURES FALL
BELOW FREEZING THROUGHOUT THE COLUMN THROUGHOUT THE FCST AREA.
SNOW ACCUMULATIONS WILL DEPEND UPON THE PROGRESS OF THE WARM
WEDGE ON FRI...AND THEN HOW MUCH FORCING / DEFORMATION EXISTS OVER
THE AREA FRI NT AS THE COLD AIR SETTLES IN.
THE AIR MASS BEHIND THIS SYSTEM WILL ACTUALLY BE OF PACIFIC ORIGIN
AND THUS BE ONLY SEASONABLY CHILLY...AND THE NEXT WARM ADVECTION
SYSTEM NEXT MON BRINGS THE CHANCE FOR A LIGHT SNOW TO RAIN
TRANSITION.
WPC TEMPERATURES LOOKED REASONABLE AND WERE GENERALLY BLENDED IN.
HAVE TEMPERATURES RISING TOWARD DAWN FRI WITH THE WARM WEDGE
EFFECT BEGINNING TO TAKE HOLD...USED GFS BASED TEMPERATURES IN
ADDITION TO WPC DURING THE STORM...THU NT INTO SAT.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AREAS OF MVFR STRATOCU THIS MORNING ALONG WITH SOME FLURRIES AND
ICE CRYSTALS EXPECTED THROUGH AROUND 15Z ACROSS S TERMINALS AND
MOUNTAIN TERMINALS.
AFTERNOON MVFR STRATOCU MAY REDEVELOP AGAIN ACROSS SE OH AND N
WV...AFFECTING KPKB/KCKB/KEKN WITH A PERIOD OF BKN MVFR CIGS.
MID AND HI CLOUDS ADVANCE INTO THE AREA FROM THE W TONIGHT AS ANY
REMAINING STRATOCU DISSIPATES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE...HIGH
ALTERNATE SCENARIOS: NONE
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 12 13 14 15 16 17 18 19 20 21 22 23
EST 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY M M M M M H H H H H H H
HTS CONSISTENCY M M M H H H H H H H H H
BKW CONSISTENCY M M M M M H H H H H H H
EKN CONSISTENCY M M M M M M M M M M M H
PKB CONSISTENCY H H H H H M M M M M M H
CKB CONSISTENCY H H H M M M M M M M M H
AFTER 12Z WEDNESDAY...
UPPER AIR DISTURBANCE WEDNESDAY/WEDNESDAY NIGHT COULD BRING LIGHT SNOW
WITH IFR.
IFR POSSIBLE WITH A WINTER STORM SYSTEM THURSDAY NIGHT INTO
SATURDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR WVZ038-046-047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/30
NEAR TERM...30/26
SHORT TERM...KTB
LONG TERM...TRM
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
534 AM EST TUE JAN 19 2016
.SYNOPSIS...
COLD CONTINUES TODAY AND TONIGHT UNDER HIGH PRESSURE AND LIGHTER WINDS.
WEAKENING SYSTEM WEDNESDAY COULD LEAVE MINOR SNOW ACCUMULATIONS. A
MAJOR WINTER STORM DEVELOPS THURSDAY NIGHT AND LINGERS INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
530 AM UPDATE...
STRATOCU REALLY FILLING IN ACROSS THE AREA DURING THESE PREDAWN
HRS. RADAR IS SHOWING VERY LIGHT RETURNS FROM THESE CLOUDS AND
PEAKING OUTSIDE THE OFFICE REVEALS ICE CRYSTALS OR FLURRIES
FALLING. WILL BEEF UP THE SKY COVER THIS MORNING AND ADD SCT
FLURRIES/ICE CRYSTALS FOR A TIME.
PREVIOUS DISCUSSION BELOW...
PESKY STRATOCU HOLDING STRONG IN THE MOUNTAINS WITH SCT FLURRIES
OR ICE CRYSTALS FALLING. OUTSIDE OF THAT...A PASSING S/W TROF
MAY BRING SOME CLOUDS INTO THE AREA THRU MORNING...ESPECIALLY
ACROSS NE KY/S WV/ AND SW VA WHERE A PASSING FLURRY CANNOT BE
RULED OUT.
HIGH PRESSURE BUILDS INTO THE REGION TODAY WHICH WILL FURTHER
DIMINISH THE WIND. STILL COULD SEE SOME GUSTS IN THE N MOUNTAINS
THOUGH. HI RES MODELS TRYING TO SHOW SOME AFTERNOON STREAKY STRATOCU
DEVELOPING OVER SE OH AND N WV AGAIN TODAY. BUMPED SKY COVER UP A
BIT THERE BUT NOT TO THE DEGREE THE HRRR WOULD SUGGEST. TEMPS TODAY
SHOULD RECOVER ABOUT 5 DEGREES FROM YESTERDAY BUT STILL COLD
OVERALL.
WITH HIGH PRESSURE OVERHEAD TONIGHT...EXPECTING A QUICK FALL IN
TEMPS THIS EVENING...ESPECIALLY OVER AREAS THAT HAVE SNOW ON THE
GROUND. HOWEVER...MID AND HI CLOUDS WILL BE ADVANCING TOWARD THE
AREA LATE WHICH WILL CAP THE FREE FALL. WAA ALOFT WILL ALSO COMMENCE
WHICH SHOULD ALLOW THE HIGHER ELEVATIONS TO SEE A SLOW RISE
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
THE WEAKENING SUPPORT/LIFT ON WEDNESDAY WILL WORK HARD TO SATURATE THE COLUMN
IN THE INITIALLY DRY ARCTIC AIR.
FEATURE IS A COMBO OF A 500 MB TROF AND WARM AIR ADVECTION IN THE LOW LEVELS.
FOR EXAMPLE...THE 850 MB FLOW OF 30 TO 40 KNOTS IS PERPENDICULAR TO THE
850 MB ISOTHERMS VCNTY STL TUESDAY EVENING. BY 18Z WEDNESDAY...THE FLOW
IS ALMOST PARALLEL TO THE ISOTHERMS. NOT MUCH CHANGE TO OUR 1 TO 2 INCH
FORECAST...BUT DID TRY TO DAMPEN THE NORTHERN COUNTIES...INCLUDING THE
ROUTE 50 CORRIDOR TO MOSTLY AN INCH OR LESS OF SNOW ACCUMULATION ON
WEDNESDAY.
MEANWHILE...TRIED TO BOOST PORTIONS OF NORTHEAST KENTUCKY...THE SOUTHERN
COAL FIELDS OF WEST VIRGINIA...BUCHANAN AND DICKENSON COUNTIES IN VIRGINIA
MORE TOWARD THE 2 INCH ACCUMULATION. IF SYSTEM DOES NOT DAMPEN QUICKER
THAN EXPECTED...WINTER WX ADVISORIES WILL LIKELY BE POSTED IN SOME COUNTIES
THAT HAVE THE 2 INCH CRITERIA...WHICH IS THE SAME THEME AS YESTERDAY.
WILL CUT BACK ON HIGH TEMPERATURES IN THE SOUTHWEST ON WEDNESDAY...WHERE
THE SNOW WILL LIKELY REACH THE GROUND IN THE MORNING.
WEDNESDAY SYSTEM LEAVES THE LOW ELEVATIONS SATURATED...COULD NOT COMPLETELY
RULE OUT SOME FREEZING DRIZZLE IN THE MOUNTAINS OR SOUTHERN COUNTIES OVERNIGHT
WEDNESDAY NIGHT IN THE WAKE OF THE SYNOPTIC LIGHT SNOW. YET...WILL NOT INSERT
YET INTO THE FORECAST. NORTHERN COUNTIES HAVE A BETTER CHANCE OF THE
LOWER CLOUDS BREAKING UP BEFORE DAWN THURSDAY.
WILL SLOW DOWN THE INCREASING POPS LATE THURSDAY IN THE EXTREME SOUTH A
FEW HOURS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ON THE MIDNIGHT SHIFT THIS TUESDAY MORNING...NO REASON TO MAKE MAJOR CHANGES
TO OUR GRIDS FOR THE MAJOR STORM. AS WE KNOW...MAJOR ADJUSTMENTS ARE WISER
AS WE GET CLOSER...INSTEAD OF SEESAWING DAYS AWAY.
WITH THE MID LEVEL AND 850 MB LOW STILL TO OUR WEST ON FRIDAY...AND A STRONG
SOUTHERLY 40 KNOT 850 MB FLOW INTO SOUTHERN WEST VIRGINIA...WE STILL LIKE
THE FORECAST RAIN WORKING NORTH OVERNIGHT THURSDAY NIGHT INTO FRIDAY
FOR SOUTHERN COUNTIES. WILL NOT ADD A WATER HAZARD AS OF YET...BUT
AGAIN...EVEN THAT COULD NOT BE COMPLETELY RULED OUT FOR SOUTHERN
COUNTIES.
HOW FAR AND QUICKLY THAT WINTRY MIX WORKS NORTH...IS THE QUESTION.
WITH SOME SE COMPONENT THOUGH IN POCAHONTAS COUNTY...WE STILL LIKE
KEEPING MOSTLY SNOW IN POCAHONTAS COUNTY.
00Z ECMWF STILL A BIT FURTHER SOUTH WITH THE MID LEVEL AND 850 MB LOW
CIRCULATION...AND THUS A BIT COLDER AT CRITICAL 850 MB LEVEL.
DID INCREASE POPS FRIDAY NIGHT INTO SATURDAY MORNING IN THE STRONG WRAP
AROUND FROM THE DEEPENING STORM TO OUR EAST.
REST OF THIS LONG TERM IS FROM OUR LATE MONDAY PACKAGE...
MODELS AGREE ON THE POTENTIAL FOR A MAJOR WINTER WEATHER SYSTEM
IMPACTING THE AREA EARLY IN THE PERIOD.
A MIDSTREAM UPPER LEVEL S/W TROUGH DIGS SEWD THROUGH THE SRN
PLAINS STATES THU...TOWARD A L/W TROUGH POSITION E OF THE
MISSISSIPPI RIVER...WITH A RIDGE BUILDING TO ITS W. THE S/W
TROUGH CLOSES OFF FRI...TRACKS ACROSS THE SRN APPALACHIANS FRI
NT...AND THEN MEANDERS UP ALONG THE ERN SEABOARD ON SAT.
THE INITIAL SFC LOW CENTER TRACKS NEWD INTO SE KY AND SW VA THU
EVENING...WITH THE INVERTED LOW LEVEL TROUGH EXTENDING NWD UP
ALONG THE OHIO RIVER...PEAKING THE WARM WEDGE EFFECT AT THAT TIME.
THAT CENTER THEN FILLS OVERNIGHT AS THE NEW LOW CENTER GETS GOING
ALONG THE EASTERN SEABOARD. THAT CENTER SLOWLY MEANDERS UP THE
EASTERN SEABOARD SAT AND SAT NT...BEFORE FINALLY PULLING OUT TO
SEA ON SUNDAY.
THIS SCENARIO IS LIKELY TO RESULT IN SNOW OVERSPREADING THE AREA
FROM S TO N THU NT...WITH A TRANSITION TO SLEET AND THEN RAIN
INTO CENTRAL PORTIONS OF THE FCST AREA FROM THE S. FREEZING RAIN
IS ALSO POSSIBLE IN THE TRANSITION. THE HIGHEST LOW LEVEL
TEMPERATURES WILL OCCUR IN THE WARM WEDGE BETWEEN THE OHIO RIVER
AND THE WV MOUNTAINS. SFC TEMPERATURES SHOULD PEAK MID TO LATE
AFTERNOON FRI...BUT THE WARM WEDGE ALOFT STARTS PUSHING EWD LATE
FRI AFTERNOON. THIS COMBINATION KEEPS THE FREEZING RAIN POTENTIAL
IN THE MORNING AND MIDDAY FRI...MAINLY FOR SRN PORTIONS OF THE
AREA AND ALONG THE ERN SLOPES OF THE SRN WV MOUNTAINS.
ACCUMULATIONS THU NT AS LIKELY TO BE LIMITED OVER THE SRN COAL
FIELDS OF WV ON ACCOUNT OF SFC TEMPERATURES THERE GETTING ABOVE
FREEZING SOON AFTER THE ONSET OF THE PRECIPITATION. AN INCH OR
TWO ARE POSSIBLE ELSEWHERE BY DAWN FRI...DEPENDING UPON HOW
QUICKLY SLEET MIXES IN RELATIVE TO THE ONSET TIME OF THE
PRECIPITATION. THE CENTRAL MOUNTAINS APPEAR MOST LIKELY TO GET
SEVERAL INCHES BY DAWN FRI AS THAT IS WHERE THERE IS LIKELY TO BE
THE MOST TIME BETWEEN THE ONSET OF THE PRECIPITATION AND THE
ARRIVAL OF ABOVE FREEZING TEMPERATURES ALOFT.
AS THE UPPER LEVEL LOW ROLLS S OF THE AREA FRI NT...THE LOW LEVEL
INVERTED TROUGH AND WARM WEDGE COLLAPSE...AND TEMPERATURES FALL
BELOW FREEZING THROUGHOUT THE COLUMN THROUGHOUT THE FCST AREA.
SNOW ACCUMULATIONS WILL DEPEND UPON THE PROGRESS OF THE WARM
WEDGE ON FRI...AND THEN HOW MUCH FORCING / DEFORMATION EXISTS OVER
THE AREA FRI NT AS THE COLD AIR SETTLES IN.
THE AIR MASS BEHIND THIS SYSTEM WILL ACTUALLY BE OF PACIFIC ORIGIN
AND THUS BE ONLY SEASONABLY CHILLY...AND THE NEXT WARM ADVECTION
SYSTEM NEXT MON BRINGS THE CHANCE FOR A LIGHT SNOW TO RAIN
TRANSITION.
WPC TEMPERATURES LOOKED REASONABLE AND WERE GENERALLY BLENDED IN.
HAVE TEMPERATURES RISING TOWARD DAWN FRI WITH THE WARM WEDGE
EFFECT BEGINNING TO TAKE HOLD...USED GFS BASED TEMPERATURES IN
ADDITION TO WPC DURING THE STORM...THU NT INTO SAT.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AREAS OF MVFR STRATOCU THIS MORNING ALONG WITH SOME FLURRIES AND
ICE CRYSTALS EXPECTED THROUGH AROUND 15Z ACROSS S TERMINALS AND
MOUNTAIN TERMINALS.
AFTERNOON MVFR STRATOCU MAY REDEVELOP AGAIN ACROSS SE OH AND N
WV...AFFECTING KPKB/KCKB/KEKN WITH A PERIOD OF BKN MVFR CIGS.
MID AND HI CLOUDS ADVANCE INTO THE AREA FROM THE W TONIGHT AS ANY
REMAINING STRATOCU DISSIPATES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE...HIGH
ALTERNATE SCENARIOS: NONE
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.
DATE TUE 01/19/16
UTC 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
EST 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16
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 M M M M M M M M M M M M
PKB CONSISTENCY H H H H H M M M M M M M
CKB CONSISTENCY H H H H H H M M M M M M
AFTER 12Z WEDNESDAY...
UPPER AIR DISTURBANCE WEDNESDAY/WEDNESDAY NIGHT COULD BRING LIGHT SNOW
WITH IFR.
IFR POSSIBLE WITH A WINTER STORM SYSTEM THURSDAY NIGHT INTO
SATURDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR WVZ038-046-047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/30
NEAR TERM...30
SHORT TERM...KTB
LONG TERM...TRM
AVIATION...30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1034 AM EST TUE JAN 19 2016
.SYNOPSIS...
ACCUMULATING LAKE EFFECT SNOW WILL TAPER OFF THROUGH THE
AFTERNOON. LIGHT SNOW IS POSSIBLE LATER WEDNESDAY OVER THE
WESTERN MOUNTAINS. A MAJOR WINTER STORM COULD BRING SIGNIFICANT
SNOWFALL TO MUCH OF CENTRAL PA FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...
LES HANGING ON ACROSS THE FAR NW AND FLURRIES OVER THE LAURELS.
WILL LINGER MORE OF THE SAME IN THE FORECAST THROUGH THE REST OF
THE DAY. SUBSIDENCE IS TRYING TO KILL THE CLOUDS...BUT THEY SEEM
TO BE EXPANDING GRADUALLY TO THE SOUTH. BUT ANYWHERE THERE IS
DOWNSLOPE THE CLOUDS DISAPPEAR. TEMPS/WIND CHILLS LOOK ON TRACK.
HAVE ALLOWED THE WC ADVY TO DIE AS ONLY A FEW SUB-15-BELOW NUMBERS
WILL BE HAD FOR A FEW MORE HOURS AS TEMPS RISE. WIND DOES NOT
SLACKEN MUCH...THOUGH.
635 AM UPDATE...CANCELLED THE LES WARNINGS FOR WARREN AND MCKEAN.
THE HEAVIEST LAKE EFFECT IS OVER WITH DIMINISHING COVERAGE TREND
EXPECTED BY AFTERNOON. AN ADDITIONAL 1-2 INCHES IS POSSIBLE IN
THE MOST PERSISTENT BANDS THIS MORNING.
PREVIOUS...MODELS DEPICT A STRONG LOBE OF VORTICITY SWINGING
THROUGH PA BY 18Z. HRRR SHOWS LES BANDS WEAKENING THROUGH THE
MORNING BEFORE TAPERING OFF BY TONIGHT...AS INCREASINGLY
ANTICYCLONIC LOW TO MID LEVEL FLOW PUSHES ACROSS THE LAKES. WITH
ONLY MINOR ADDITIONAL LES ACCUMULATIONS EXPECTED...WILL ALLOW THE
LES HEADLINES EXPIRE AS SCHEDULED AT 12Z/7AM. WIND CHILL HAZARD
ALSO ON TRACK TO EXPIRE AT 10AM AS MINIMUM WIND CHILLS TREND INTO
THE NEGATIVE SINGLE DIGITS. OVERALL IT WILL BE ANOTHER BRISK AND
VERY COLD DAY WITH WIND CHILLS IN THE SINGLE DIGITS +/- ZERO. WEAK
RIDGING SURFACE AND ALOFT SLIDES INTO THE AREA FROM THE OH VALLEY
TONIGHT WITH NO SIGNIFICANT WEATHER EXPECTED. LOWS WILL RANGE FROM
THE POSITIVE SINGLE DIGITS IN THE LAURELS TO THE MID TEENS ACROSS
THE MID TO LOWER SUSQUEHANNA VALLEY.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
SPLIT FLOW TROUGH WILL MIGRATE QUICKLY EASTWARD FROM THE PLAINS TO
THE EAST COAST BY 21/1200Z. MODELS SHOW THE NORTHERN STREAM SYSTEM
BEING MORE AMPLIFIED AS IT TRACKS FROM THE MIDWEST THROUGH THE NRN
MID-ATLANTIC STATES. WITH MOISTURE LACKING...MODEST HEIGHT FALLS
COULD COMBINE WITH WEAK WAA TO BRING A PERIOD OF LIGHT SNOW OVER
THE ALLEGHENY RIDGES LATER WEDNESDAY INTO WEDNESDAY NIGHT. ANY
SNOW ACCUMS WOULD BE AN INCH OR LESS BASED ON BLENDED MEAN QPF.
FOLLOWING THE PASSAGE OF THE AFOREMENTIONED NORTHERN STREAM
SYSTEM...LAKE EFFECT TRAJECTORIES BECOME REESTABLISHED WITH MINOR
ACCUMS POSSIBLE IN THE NORTHWEST SNOWBELT. THE LES CONNECTION
APPEARS TO BE RATHER SHORT-LIVED ESPECIALLY FROM ERIE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THURSDAY FCST/DAY 3 WX LOOKS QUIET UNDER HIGH PRESSURE. ALL EYES
WILL TURN TO LOW PRESSURE SYSTEM DEVELOPING INTO THE TN VALLEY
AND SOUTHERN APPALACHIANS BY THURSDAY NIGHT.
THE PRIMARY IMPACTS THIS PERIOD WILL BE FOR GROWING CONFIDENCE IN
A MAJOR EAST COAST WINTER STORM INCLUDING HEAVY SNOW POTENTIAL IN
CENTRAL PENNSYLVANIA. EXPECT THE MODEL SPREAD WITH THIS SYSTEM TO
CONTINUE TO NARROW AS THE UPPER LEVEL FEATURE COMES ONSHORE OVER
THE PACIFIC NW TONIGHT. WHILE IT IS STILL TO EARLY TO GET INTO THE
SPECIFIC DETAILS...HERE ARE SOME EARLY GOAL POSTS:
PTYPE: MODEL CONSENSUS AT THIS TIME FAVORS SNOW AS THE PRIMARY
WINTER PTYPE NEAR AND NORTHWEST OF THE I-95 URBAN CORRIDOR
TIMING: GFS/CMC/WPC QPF WOULD SUGGEST A FRIDAY MORNING ONSET
SPREADING FROM SOUTH TO NORTH BY THE AFTERNOON. THE ECMWF IS
SLOWER.
DURATION: SNOW COULD LAST THROUGH SATURDAY BEFORE ENDING SATURDAY
NIGHT/EARLY SUNDAY MORNING.
GREATEST RISK FOR HEAVY SNOW: SOUTH-CENTRAL AND SOUTHEASTERN
ZONES OR ROUGHLY THE SOUTHEAST 1/2 TO 1/3 OF THE CWA. BLOWING AND
DRIFTING POSSIBLE.
IMPROVING CONDITIONS LIKELY ARE ON SUNDAY WITH HIGH PRESSURE
RETURNING TO THE AREA. TEMPERATURES ARE FCST TO TREND WARMER TO
NEAR NORMAL LEVELS BY MONDAY.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
WILL LINGER LOWERED VIS/CIGS OVER THE NW FOR A FEW MORE HOURS AT
EACH SITE. KBFD MAY CONTINUE TO HAVE IFR VIS FOR MUCH OF THE AFTN
AS CROSS LAKE FLOW STILL MAKES IT FAVORABLE. KJST ALSO NOT
IMPROVING MUCH AND WILL CONTINUE ON WITH THOSE FOR ANOTHER FEW
HRS.
PREV...
PERSISTENT SNOW BAND REMAINS ACROSS THE NW MTNS. THIS CONTINUES TO
BRING IFR AND LOWER VSBYS TO BFD. THE GUSTY FLOW SHOULD CONTINUE
THE LAKE EFFECT THROUGH THE MORNING. THE WINDS SHOULD SHIFT TO THE
NORTH...THOUGH THIS ALONE WILL NOT CEASE ANY SHOWERS. HOWEVER...A
BUILDING RIDGE WILL REDUCE INSTABILITY ENOUGH TUESDAY AFTERNOON TO
END SHOWER ACTIVITY AND ALLOW FOR IMPROVING CONDITIONS.
IMPROVING CONDS AT KJST...THOUGH UPSLOPE FLOW HAS BROUGHT MVFR
CIGS TO AOO...UNV AND JST. FOR THE REST OF CENTRAL PA...THE
DRYING EFFECT OF DOWNSLOPING WESTERLY FLOW SHOULD YIELD VFR FLYING
OVERNIGHT.
HIGH PRESSURE BUILDING IN FROM THE MIDWEST WILL CAUSE LAKE EFFECT
SNOW TO TAPER OFF ACROSS THE NW MTNS TUESDAY. HOWEVER...RESIDUAL
LOW LVL MOISTURE ASCENDING THE ALLEGHENIES SHOULD CAUSE MVFR
STRATOCU TO PERSIST INTO TUE EVENING AT KBFD AND KJST. AFTER A BIT
OF A LULL IN THE WINDS OVERNIGHT...EXPECT GUSTY WINDS TO REDEVELOP ACROSS
THE ENTIRE AREA FROM LATE AM THRU EARLY EVENING TUES...AS DIURNAL
HEATING/DEEPENING BLYR DEPTH ALLOW STRONGER WINDS TO MIX TO THE
SFC. BUFKIT SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS TUE AFTN.
OUTLOOK...
WED...A BRIEF EVENING -SHSN/VIS REDUCTION POSSIBLE KJST/KBFD.
THU...NO SIG WX EXPECTED.
FRI...SNOW POSSIBLE...ESP SOUTH.
SAT...SNOW/WIND POSSIBLE...ESP SOUTH/EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...DANGELO/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
759 AM EST TUE JAN 19 2016
.SYNOPSIS...
ACCUMULATING LAKE EFFECT SNOW WILL END THIS MORNING. LIGHT SNOW
IS POSSIBLE LATER WEDNESDAY. A MAJOR WINTER STORM COULD BRING
SIGNIFICANT SNOWFALL TO MUCH OF CENTRAL PA FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
635 AM UPDATE...CANCELLED THE LES WARNINGS FOR WARREN AND MCKEAN.
THE HEAVIEST LAKE EFFECT IS OVER WITH DIMINISHING COVERAGE TREND
EXPECTED BY AFTERNOON. AN ADDITIONAL 1-2 INCHES IS POSSIBLE IN
THE MOST PERSISTENT BANDS THIS MORNING.
PREVIOUS...MODELS DEPICT A STRONG LOBE OF VORTICITY SWINGING
THROUGH PA BY 18Z. HRRR SHOWS LES BANDS WEAKENING THROUGH THE
MORNING BEFORE TAPERING OFF BY TONIGHT...AS INCREASINGLY
ANTICYCLONIC LOW TO MID LEVEL FLOW PUSHES ACROSS THE LAKES. WITH
ONLY MINOR ADDITIONAL LES ACCUMULATIONS EXPECTED...WILL ALLOW THE
LES HEADLINES EXPIRE AS SCHEDULED AT 12Z/7AM. WIND CHILL HAZARD
ALSO ON TRACK TO EXPIRE AT 10AM AS MINIMUM WIND CHILLS TREND INTO
THE NEGATIVE SINGLE DIGITS. OVERALL IT WILL BE ANOTHER BRISK AND
VERY COLD DAY WITH WIND CHILLS IN THE SINGLE DIGITS +/- ZERO. WEAK
RIDGING SURFACE AND ALOFT SLIDES INTO THE AREA FROM THE OH VALLEY
TONIGHT WITH NO SIGNIFICANT WEATHER EXPECTED. LOWS WILL RANGE FROM
THE POSITIVE SINGLE DIGITS IN THE LAURELS TO THE MID TEENS ACROSS
THE MID TO LOWER SUSQUEHANNA VALLEY.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
SPLIT FLOW TROUGH WILL MIGRATE QUICKLY EASTWARD FROM THE PLAINS TO
THE EAST COAST BY 21/1200Z. MODELS SHOW THE NORTHERN STREAM SYSTEM
BEING MORE AMPLIFIED AS IT TRACKS FROM THE MIDWEST THROUGH THE NRN
MID-ATLANTIC STATES. WITH MOISTURE LACKING...MODEST HEIGHT FALLS
COULD COMBINE WITH WEAK WAA TO BRING A PERIOD OF LIGHT SNOW OVER
THE ALLEGHENY RIDGES LATER WEDNESDAY INTO WEDNESDAY NIGHT. ANY
SNOW ACCUMS WOULD BE AN INCH OR LESS BASED ON BLENDED MEAN QPF.
FOLLOWING THE PASSAGE OF THE AFOREMENTIONED NORTHERN STREAM
SYSTEM...LAKE EFFECT TRAJECTORIES BECOME REESTABLISHED WITH MINOR
ACCUMS POSSIBLE IN THE NORTHWEST SNOWBELT. THE LES CONNECTION
APPEARS TO BE RATHER SHORT-LIVED ESPECIALLY FROM ERIE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THURSDAY FCST/DAY 3 WX LOOKS QUIET UNDER HIGH PRESSURE. ALL EYES
WILL TURN TO LOW PRESSURE SYSTEM DEVELOPING INTO THE TN VALLEY
AND SOUTHERN APPALACHIANS BY THURSDAY NIGHT.
THE PRIMARY IMPACTS THIS PERIOD WILL BE FOR GROWING CONFIDENCE IN
A MAJOR EAST COAST WINTER STORM INCLUDING HEAVY SNOW POTENTIAL IN
CENTRAL PENNSYLVANIA. EXPECT THE MODEL SPREAD WITH THIS SYSTEM TO
CONTINUE TO NARROW AS THE UPPER LEVEL FEATURE COMES ONSHORE OVER
THE PACIFIC NW TONIGHT. WHILE IT IS STILL TO EARLY TO GET INTO THE
SPECIFIC DETAILS...HERE ARE SOME EARLY GOAL POSTS:
PTYPE: MODEL CONSENSUS AT THIS TIME FAVORS SNOW AS THE PRIMARY
WINTER PTYPE NEAR AND NORTHWEST OF THE I-95 URBAN CORRIDOR
TIMING: GFS/CMC/WPC QPF WOULD SUGGEST A FRIDAY MORNING ONSET
SPREADING FROM SOUTH TO NORTH BY THE AFTERNOON. THE ECMWF IS
SLOWER.
DURATION: SNOW COULD LAST THROUGH SATURDAY BEFORE ENDING SATURDAY
NIGHT/EARLY SUNDAY MORNING.
GREATEST RISK FOR HEAVY SNOW: SOUTH-CENTRAL AND SOUTHEASTERN
ZONES OR ROUGHLY THE SOUTHEAST 1/2 TO 1/3 OF THE CWA. BLOWING AND
DRIFTING POSSIBLE.
IMPROVING CONDITIONS LIKELY ARE ON SUNDAY WITH HIGH PRESSURE
RETURNING TO THE AREA. TEMPERATURES ARE FCST TO TREND WARMER TO
NEAR NORMAL LEVELS BY MONDAY.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
PERSISTENT SNOW BAND REMAINS ACROSS THE NW MTNS. THIS CONTINUES TO
BRING IFR AND LOWER VSBYS TO BFD. THE GUSTY FLOW SHOULD CONTINUE
THE LAKE EFFECT THROUGH THE MORNING. THE WINDS SHOULD SHIFT TO THE
NORTH...THOUGH THIS ALONE WILL NOT CEASE ANY SHOWERS. HOWEVER...A
BUILDING RIDGE WILL REDUCE INSTABILITY ENOUGH TUESDAY AFTERNOON TO
END SHOWER ACTIVITY AND ALLOW FOR IMPROVING CONDITIONS.
IMPROVING CONDS AT KJST...THOUGH UPSLOPE FLOW HAS BROUGHT MVFR
CIGS TO AOO...UNV AND JST. FOR THE REST OF CENTRAL PA...THE
DRYING EFFECT OF DOWNSLOPING WESTERLY FLOW SHOULD YIELD VFR FLYING
OVERNIGHT.
HIGH PRESSURE BUILDING IN FROM THE MIDWEST WILL CAUSE LAKE EFFECT
SNOW TO TAPER OFF ACROSS THE NW MTNS TUESDAY. HOWEVER...RESIDUAL
LOW LVL MOISTURE ASCENDING THE ALLEGHENIES SHOULD CAUSE MVFR
STRATOCU TO PERSIST INTO TUE EVENING AT KBFD AND KJST. AFTER A BIT
OF A LULL IN THE WINDS OVERNIGHT...EXPECT GUSTY WINDS TO REDEVELOP ACROSS
THE ENTIRE AREA FROM LATE AM THRU EARLY EVENING TUES...AS DIURNAL
HEATING/DEEPENING BLYR DEPTH ALLOW STRONGER WINDS TO MIX TO THE
SFC. BUFKIT SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS TUE AFTN.
OUTLOOK...
WED...A BRIEF EVENING -SHSN/VIS REDUCTION POSSIBLE KJST/KBFD.
THU...NO SIG WX EXPECTED.
FRI...SNOW POSSIBLE...ESP SOUTH.
SAT...SNOW/WIND POSSIBLE...ESP SOUTH/EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ024-
033.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
637 AM EST TUE JAN 19 2016
.SYNOPSIS...
ACCUMULATING LAKE EFFECT SNOW WILL END THIS MORNING. LIGHT SNOW
IS POSSIBLE LATER WEDNESDAY. A MAJOR WINTER STORM COULD BRING
SIGNIFICANT SNOWFALL TO MUCH OF CENTRAL PA FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
635 AM UPDATE...CANCELLED THE LES WARNINGS FOR WARREN AND MCKEAN.
THE HEAVIEST LAKE EFFECT IS OVER WITH DIMINISHING COVERAGE TREND
EXPECTED BY AFTERNOON. AN ADDITIONAL 1-2 INCHES IS POSSIBLE IN
THE MOST PERSISTENT BANDS THIS MORNING.
PREVIOUS...MODELS DEPICT A STRONG LOBE OF VORTICITY SWINGING
THROUGH PA BY 18Z. HRRR SHOWS LES BANDS WEAKENING THROUGH THE
MORNING BEFORE TAPERING OFF BY TONIGHT...AS INCREASINGLY
ANTICYCLONIC LOW TO MID LEVEL FLOW PUSHES ACROSS THE LAKES. WITH
ONLY MINOR ADDITIONAL LES ACCUMULATIONS EXPECTED...WILL ALLOW THE
LES HEADLINES EXPIRE AS SCHEDULED AT 12Z/7AM. WIND CHILL HAZARD
ALSO ON TRACK TO EXPIRE AT 10AM AS MINIMUM WIND CHILLS TREND INTO
THE NEGATIVE SINGLE DIGITS. OVERALL IT WILL BE ANOTHER BRISK AND
VERY COLD DAY WITH WIND CHILLS IN THE SINGLE DIGITS +/- ZERO. WEAK
RIDGING SURFACE AND ALOFT SLIDES INTO THE AREA FROM THE OH VALLEY
TONIGHT WITH NO SIGNIFICANT WEATHER EXPECTED. LOWS WILL RANGE FROM
THE POSITIVE SINGLE DIGITS IN THE LAURELS TO THE MID TEENS ACROSS
THE MID TO LOWER SUSQUEHANNA VALLEY.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
SPLIT FLOW TROUGH WILL MIGRATE QUICKLY EASTWARD FROM THE PLAINS TO
THE EAST COAST BY 21/1200Z. MODELS SHOW THE NORTHERN STREAM SYSTEM
BEING MORE AMPLIFIED AS IT TRACKS FROM THE MIDWEST THROUGH THE NRN
MID-ATLANTIC STATES. WITH MOISTURE LACKING...MODEST HEIGHT FALLS
COULD COMBINE WITH WEAK WAA TO BRING A PERIOD OF LIGHT SNOW OVER
THE ALLEGHENY RIDGES LATER WEDNESDAY INTO WEDNESDAY NIGHT. ANY
SNOW ACCUMS WOULD BE AN INCH OR LESS BASED ON BLENDED MEAN QPF.
FOLLOWING THE PASSAGE OF THE AFOREMENTIONED NORTHERN STREAM
SYSTEM...LAKE EFFECT TRAJECTORIES BECOME REESTABLISHED WITH MINOR
ACCUMS POSSIBLE IN THE NORTHWEST SNOWBELT. THE LES CONNECTION
APPEARS TO BE RATHER SHORT-LIVED ESPECIALLY FROM ERIE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THURSDAY FCST/DAY 3 WX LOOKS QUIET UNDER HIGH PRESSURE. ALL EYES
WILL TURN TO LOW PRESSURE SYSTEM DEVELOPING INTO THE TN VALLEY
AND SOUTHERN APPALACHIANS BY THURSDAY NIGHT.
THE PRIMARY IMPACTS THIS PERIOD WILL BE FOR GROWING CONFIDENCE IN
A MAJOR EAST COAST WINTER STORM INCLUDING HEAVY SNOW POTENTIAL IN
CENTRAL PENNSYLVANIA. EXPECT THE MODEL SPREAD WITH THIS SYSTEM TO
CONTINUE TO NARROW AS THE UPPER LEVEL FEATURE COMES ONSHORE OVER
THE PACIFIC NW TONIGHT. WHILE IT IS STILL TO EARLY TO GET INTO THE
SPECIFIC DETAILS...HERE ARE SOME EARLY GOAL POSTS:
PTYPE: MODEL CONSENSUS AT THIS TIME FAVORS SNOW AS THE PRIMARY
WINTER PTYPE NEAR AND NORTHWEST OF THE I-95 URBAN CORRIDOR
TIMING: GFS/CMC/WPC QPF WOULD SUGGEST A FRIDAY MORNING ONSET
SPREADING FROM SOUTH TO NORTH BY THE AFTERNOON. THE ECMWF IS
SLOWER.
DURATION: SNOW COULD LAST THROUGH SATURDAY BEFORE ENDING SATURDAY
NIGHT/EARLY SUNDAY MORNING.
GREATEST RISK FOR HEAVY SNOW: SOUTH-CENTRAL AND SOUTHEASTERN
ZONES OR ROUGHLY THE SOUTHEAST 1/2 TO 1/3 OF THE CWA. BLOWING AND
DRIFTING POSSIBLE.
IMPROVING CONDITIONS LIKELY ARE ON SUNDAY WITH HIGH PRESSURE
RETURNING TO THE AREA. TEMPERATURES ARE FCST TO TREND WARMER TO
NEAR NORMAL LEVELS BY MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
PERSISTENT SNOW BAND REMAINS ACROSS THE NW MTNS. THIS CONTINUES TO
BRING IFR VSBYS TO BFD. NEAR TERM MDL DATA CONTINUES TO INDICATE LAKE
EFFECT PLUME WILL SHIFT SOUTH AFTER MIDNIGHT...FAVORING
PREDOMINANTLY IFR CONDS BTWN 05Z- 12Z. EXPECT FOR THESE CONDITIONS
TO REMAIN SO THROUGH THE EARLY MORNING HOURS. THE GUSTY FLOW
SHOULD CONTINUE THE LAKE EFFECT THROUGH THE MORNING. THE WINDS
SHOULD SHIFT TO THE NORTH...THOUGH THIS ALONE WILL NOT CEASE ANY
SHOWERS. HOWEVER...A BUILDING RIDGE WILL REDUCE INSTABILITY
ENOUGH TUESDAY AFTERNOON TO END SHOWER ACTIVITY AND ALLOW FOR
IMPROVING CONDITIONS.
IMPROVING CONDS AT KJST...THOUGH RADAR INDICATES A BAND OF SHOWERS
TO THE NORTH...THAT IF IT MOVES SOUTH COULD BRING BACK IFR
CONDITIONS TO JST. THIS COULD HAPPEN BETWEEN 06Z TO 09Z...HOWEVER
MVFR CONDITIONS SHOULD REMAIN DOMINATE THROUGH THIS TIMEFRAME
OUTSIDE ANY BRIEF PERIODS OF IFR IN PASSING SHOWERS. FOR THE REST
OF CENTRAL PA...THE DRYING EFFECT OF DOWNSLOPING WESTERLY FLOW
SHOULD YIELD VFR FLYING OVERNIGHT.
HIGH PRESSURE BUILDING IN FROM THE MIDWEST WILL CAUSE LAKE EFFECT
SNOW TO TAPER OFF ACROSS THE NW MTNS TUESDAY. HOWEVER...RESIDUAL
LOW LVL MOISTURE ASCENDING THE ALLEGHENIES SHOULD CAUSE MVFR
STRATOCU TO PERSIST INTO TUE EVENING AT KBFD AND KJST. AFTER A BIT
OF A LULL IN THE WINDS OVERNIGHT...EXPECT GUSTY WINDS TO REDEVELOP ACROSS
THE ENTIRE AREA FROM LATE AM THRU EARLY EVENING TUES...AS DIURNAL
HEATING/DEEPENING BLYR DEPTH ALLOW STRONGER WINDS TO MIX TO THE
SFC. BUFKIT SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS TUE AFTN.
OUTLOOK...
WED...A BRIEF EVENING -SHSN/VIS REDUCTION POSSIBLE KJST/KBFD.
THU...NO SIG WX EXPECTED.
FRI...SNOW POSSIBLE...ESP SOUTH.
SAT...SNOW/WIND POSSIBLE...ESP SOUTH/EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ024-
033.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
301 PM MST TUE JAN 19 2016
.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL BRING A CHANCE OF LIGHT PRECIPITATION
TO MAINLY NORTHERN ARIZONA TONIGHT. HIGH PRESSURE WILL BUILD ACROSS
THE DESERT SOUTHWEST WEDNESDAY CONTINUING INTO THE WEEKEND.
TEMPERATURES A FEW DEGREES ABOVE NORMAL ARE EXPECTED BY LATE IN THE
WEEK.
&&
.DISCUSSION...
MID AND HIGH CLOUDS CONTINUE TO BE ON THE INCREASE AHEAD OF A FAST-
MOVING LOW PRESSURE SYSTEM AFFECTING THE CA COAST. LATEST MRMS SHOWS
A WIDESPREAD AREA OF LIGHT SHOWER ACTIVITY SLIDING EASTWARD THROUGH
CENTRAL AND SOUTHERN CA. HI-RES WRFS INCLUDING THE HRRR CONTINUE TO
INDICATE A BRIEF OPPORTUNITY FOR LIGHT PRECIPITATION
OVERNIGHT...MAINLY ACROSS NORTHERN AND CENTRAL AZ. LATEST NCAR
ENSEMBLE SUGGESTS A LIGHT SHOWER IS EVEN POSSIBLE ACROSS THE PHOENIX
AREA. HOWEVER...PROBABILITIES GENERALLY REMAIN LESS THAN 10
PERCENT...EXCEPT ACROSS THE HIGHER TERRAIN OF SOUTHERN GILA COUNTY.
STRONG SUBSIDENCE AND A RAPID CLEARING TREND WILL THEN TAKE PLACE
DURING THE PRE-DAWN HOURS. LOW TEMPERATURES OVERNIGHT WILL BE NEAR
NORMAL.
&&
.PREVIOUS DISCUSSION...
RIDGING WILL BUILD INTO THE DESERT SOUTHWEST BEHIND THIS TROUGH ON
WEDNESDAY AND REMAIN IN PLACE THROUGH AT LEAST SATURDAY. SATURDAY
NIGHT WILL SEE THE TAIL END OF A WEAK TROUGH MOVE THROUGH SOUTHERN
CALIFORNIA AND ARIZONA. HOWEVER...A NEGLIGIBLE INCREASE IN PRE-
FRONTAL MOISTURE AND LITTLE TO NO NOTEWORTHY ISENTROPIC ASCENT WILL
PRECLUDE WIDESPREAD PRECIP DEVELOPMENT ACROSS THE AREA. NAEFS STILL
MAINTAINS 10 POPS EAST OF PHOENIX AND THIS SEEMS
REASONABLE...OTHERWISE SINGLE DIGIT POPS APPEAR TO BE ALL THAT IS
WARRANTED. WEAK RIDGING WILL RETURN EARLY NEXT WEEK.
AS FOR TEMPERATURES...EXPECT BOTH HIGHS AND LOWS TO BE WITHIN A FEW
DEGREES OF NORMAL THROUGH SATURDAY. WEAK POST-FRONTAL COLD ADVECTION
COULD KNOCK TEMPS BACK INTO THE LOW/MID 60S SUNDAY AND MONDAY BUT
ASIDE FROM THAT...NO MAJOR DEPARTURES FROM NORMAL ARE EXPECTED AT ANY
TIME OVER THE NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
A WEAK DISTURBANCE WILL WORK IT`S WAY INTO SE CALIFORNIA TODAY AND
THEN INTO ARIZONA DURING THE LATE AFTERNOON AND TONIGHT. THIS WILL
BRING THE NEXT ROUND OF HIGH TO MID CLOUD CIGS OVER THE SE
CALIFORNIA TAF SITES THIS MORNING AND THEN INTO THE PHX VALLEY TAF
SITES BY LATE AFTERNOON AND THROUGH TONIGHT. EXPECT WINDS TO REMAIN
LIGHT TO OCCASIONALLY LIGHT AND VARIABLE AND GENERALLY FAVOR
FAMILIAR DIURNAL PATTERNS ALONG WITH GOOD VISIBILITIES THROUGHOUT
THE PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A HIGH PRESSURE RIDGE WILL DOMINATE THE AREA THURSDAY AND FRIDAY
BRINGING A SLIGHT WARMING TREND WITH SLIGHTLY ABOVE NORMAL HIGH
TEMPERATURES THROUGH FRIDAY. THEN THE NEXT WEAK SYSTEMS MOVE THROUGH
FRIDAY NIGHT/SATURDAY MORNING AND SUNDAY HELPING TO BRING HIGH
TEMPERATURES BACK TO NEAR NORMAL ON SATURDAY AND SLIGHTLY BELOW
NORMAL SUNDAY ALONG WITH VERY LITTLE CHANCE OF RAIN. EXPECT WINDS TO
BE GENERALLY LIGHT AND FOLLOW USUAL DIURNAL TENDENCIES WITH SOME
AFTERNOON WESTERLY AND NORTHWESTERLY BREEZES ON SUNDAY AFTERNOON IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA WITH WIND GUSTS OF ABOUT
15 TO 22 KNOTS. MINIMUM HUMIDITIES WILL RANGE FROM THE MID/UPPER
TEENS TO THE LOW/MID 20S PERCENT RANGE ON ALL DAYS EXCEPT FOR SUNDAY
WHEN THEY WILL TEMPORARILY BUMP UP TO THE UPPER 20S TO MID 30S
PERCENT RANGE. EXPECT GOOD TO EXCELLENT OVERNIGHT RECOVERIES.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...SAWTELLE
FIRE WEATHER...SAWTELLE
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1011 AM PST TUE JAN 19 2016
.SYNOPSIS...RAIN THIS MORNING...HEAVY AT TIMES BEFORE TURNING TO
SHOWERS FOR THE MIDDAY AND EARLY AFTERNOON HOURS. HIGH PRESSURE
BUILDS TONIGHT THROUGH THURSDAY WITH A PERIOD OF DRY AND
SEASONABLY MILD WEATHER. NEXT FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY WITH A PERIOD OF LIGHT RAIN...POSSIBLY BECOMING HEAVY FOR A
TIME FRIDAY NIGHT WHEN THE UPPER LOW PASSES OVERHEAD WITH
LINGERING SHOWERS SATURDAY. LATEST INDICATIONS SHOW A RETURN OF
DRY WEATHER SUNDAY THROUGH THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...AS OF 09:50 AM PST TUESDAY...THE MAIN RAIN BAND
PRODUCING MODERATE TO HEAVY RAIN CONTINUES TO SHIFT SOUTHWARD
THROUGH THE SOUTH BAY AND MONTEREY BAY REGION AT THIS HOUR.
RAINFALL RATES HAVE BEEN UPWARD OF 3/4" PER HOUR IN THE COASTAL
RANGES WITH 1/10" TO 1/4" FOR URBAN AREAS. FURTHER NORTH AND BACK
BEHIND THE BOUNDARY, ISOLATED TO SCATTERED SHOWERS WILL REMAIN
POSSIBLE THROUGH THE MORNING. OVERALL, EXPECTING CONDITIONS TO
CLEAR FROM NORTH TO SOUTH THROUGH THE AFTERNOON. UPDATED SHORT-
TERM FORECAST HAS BEEN SENT. PLEASE SEE PREVIOUS DISCUSSION FOR
MORE DETAILS ON THE EXTENDED FORECAST PERIOD.
&&
.PREV DISCUSSION...AS OF 3:52 AM PST TUESDAY...INITIAL RAIN BAND
IS MOVING ONSHORE AS OF THIS WRITING...MAINLY ARRIVING FROM THE
WEST WITH RAIN DEVELOPING OVER MOST OF THE DISTRICT. AMOUNTS SO
FAR HAVE BEEN LIGHT BUT THAT SHOULD CHANGE QUICKLY OVER THE NEXT
SEVERAL HOURS THAT WILL ENCOMPASS THE MORNING COMMUTE. SATELLITE
IMAGERY SHOWS RAPIDLY COOLING CLOUD TOPS OFFSHORE WITH INCOMING
JET STREAK AND ASSOCIATED SHORTWAVE. AMSU TPW SHOWS GOOD MOISTURE
TAP BUT BEST PLUME OF 1.5 TPW MAY STAY JUST OFFSHORE. LATEST
OBSERVED TRENDS SUGGESTS THAT SOME OF THE HEAVIEST RAIN MAY NOW
SHIFT SLIGHTLY SOUTHWARD AND IMPACT THE SANTA CRUZ MTNS AND SANTA
LUCIA RANGE ABOVE BIG SUR. THE HRRR AND RAP MESOSCALE/SHORT TERM
MODELS SHOW 3-4 INCHES FOR THE SANTA CRUZ MTNS WITH SOME OF THE
HRRR RUNS IN EXCESS OF 7 INCHES ABOVE BIG SUR...ALL OCCURRING OVER
THE NEXT 8-10 HOURS. WILL BE WATCHING RAIN RATES AND TRENDS
CLOSELY THE NEXT FEW HOURS FOR POSSIBLE URBAN AND SMALL STREAM
FLOOD ADVISORIES THROUGHOUT THE BAY AREA...WITH POSSIBILITY THAT
WARNINGS COULD BE NEEDED FOR THE HILLS ABOVE BIG SUR. UPSHOT IS
THAT THE COMMUTE WILL QUICKLY TURN UGLY FOR THE BAY AREA WITH
HEAVIEST RAINS FROM NOW THROUGH ROUGHLY 18-20Z. SIMILAR TO
YESTERDAYS STORM THE STEADY RAIN SHOULD END ABRUPTLY AROUND MIDDAY
IN THE BAY AREA WHILE HANGING ON LONGER FOR THE CENTRAL COAST.
SHOWERS THIS AFTERNOON BUT EVEN THOSE WILL BE LIMITED WITH SOME
LATE DAY PEAKS OF SUNSHINE. WINDS WITH TODAYS FRONT WILL BE
SOUTHERLY THIS MORNING....STRONGEST ON THE COAST AND OVER THE
OCEAN WITH GUSTS AROUND 30 MPH. WINDS TURN WEST BY MIDDAY BUT
GIVEN THE LACK OF COLD ADVECTION THE WESTERLY WINDS WONT BE TOO
STRONG.
HAVE REMOVED ALL CHANCES OF RAIN FOR THIS EVENING AS THE SYSTEM
WILL QUICKLY MOVE EASTWARD. HIGH PRESSURE BUILDS IN TONIGHT AND
LASTS THROUGH THURSDAY. AIRMASS IS MILD AND EXPECT DAYTIME HIGHS
TO BE COMFORTABLY IN THE 60S MIDWEEK WITH MILD OVERNIGHT LOWS
GENERALLY IN THE 40S.
NEXT FRONT ARRIVES THURSDAY NIGHT. INITIAL BOUNDARY DOESN`T LOOK
TOO IMPRESSIVE WITH SOUTHERLY WINDS NOT-FAVORABLE FOR OROGRAPHICS.
GFS AND ECMWF BOTH SHOW FAIRLY WEAK FRONT MOVING THROUGH TIL
MIDDAY FRIDAY...THEN COLD UPPER TROUGH SHOULD PASS OVER THE REGION
AND ALLOW FOR AN UPTICK IN RAIN SHOWERS AND INTENSITY WITH SHOWERS
LASTING INTO SATURDAY. STILL SEVERAL DAYS OUT SO THAT WILL BECOME
THE FOCUS AFTER TODAYS EVENT.
LATEST MODEL TREND OVER THE LAST 24 HOURS HAS BEEN TO BUILD HIGH
PRESSURE SATURDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK. IN
COORDINATION WITH WFO EUREKA REMOVED NEARLY ALL RAIN CHANCES FOR
THE NORTH BAY AS WELL AS THE REST OF THE DISTRICT AFTER SATURDAY
NIGHT.
HOWEVER MUST POINT OUT THE LONG RANGE GFS CONTINUES TO SHOW
ANOTHER COLD WEST COAST TROUGH AND ASSOCIATED RAIN ARRIVING
SOMETIME AROUND JAN 29TH WITH EXTENDED GFS AND CFS MODELS KEEPING
PATTERN ACTIVE.
&&
.AVIATION...AS OF 10:00 AM PST TUESDAY...DYNAMIC
FORECAST...ESPECIALLY IN THE SHORT TERM...AS A COLD FRONT MOVES
THROUGH. THE FRONT LOOKS BE BE ENTERING THE N BAY WITH A WIND
SHIFT ALREADY SHOWING UP THE ON BUOYS. THE HEAVIEST RAIN HAS
ALREADY MOVED THROUGH SFO/OAK/STS. WINDS WILL REMAIN GUSTY
THROUGH THE MORNING. DO EXPECT CONDITIONS TO BE IMPROVING AT ALL
SITE BY THIS AFTERNOON. THE REAL QUESTION/UNCERTAINTY WILL BE HOW
MUCH CLEARING OCCURS. VIS SATELLITE SHOWS A LOT OF CLEARING TO THE
WEST...BUT RESIDUAL MOISTURE AND DAYTIME HEATING MAY ACTUALLY
LIMIT THIS. AS FOR TONIGHT...RESIDUAL MOISTURE AND COOLING WILL
LIKELY LEAD TO LOW CLOUDS AND POSS FOG. WILL DEFINITELY HAVE TO
WATCH FOR RAPID DEVELOPMENT OF ANY DENSE FOG. CONF IS MEDIUM FOR
THE ENTIRE FORECAST.
VICINITY OF KSFO...LIGHT RAIN CONTINUES...BUT HEAVIEST HAS ENDED.
VIS WILL REMAIN LOW WITH CIGS IN THE MVFR RANGE. AS FOR
WINDS...THE SHIFT TO SW HAS ALREADY OCCURRED AND WILL REMAIN THERE
FOR THE DAY. WIND SPEEDS HAVE PEAKED...BUT WILL REMAIN GUSTY. WILL
KEEP LINGERING CLOUDS THROUGH THE DAY GIVEN THE AMOUNT OF LOW
LEVEL MOISTURE.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MODERATE TO HEAVY RAIN OVER THE NEXT
FEW HOURS WITH REDUCED VIS AND LOWERED CIGS. IMPROVEMENT EXPECTED
AFTER 20Z THIS AFTERNOON. CIGS AND FOG RETURN TONIGHT...POSS DENSE
FOG.
&&
.MARINE...AS OF 09:58 AM PST TUESDAY...STRONG AND GUSTY WINDS WILL
PREVAIL TODAY AS A STORM SYSTEM PASSING THROUGH THE REGION. WINDS
WILL DECREASE RAPIDLY THIS EVENING AFTER THE STORM PASSES. ANOTHER
STORM WILL BRING INCREASING WINDS AGAIN BY FRIDAY. A LONG PERIOD
LARGE SWELL IS FORECAST TO IMPACT THE REGION LATER THIS WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...SF BAY UNTIL 3 PM
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 3 PM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 3 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 3 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM
SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM
&&
$$
PUBLIC FORECAST: RGASS
AVIATION: MM
MARINE: MM
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
954 AM PST TUE JAN 19 2016
.SYNOPSIS...RAIN THIS MORNING...HEAVY AT TIMES BEFORE TURNING TO
SHOWERS FOR THE MIDDAY AND EARLY AFTERNOON HOURS. HIGH PRESSURE
BUILDS TONIGHT THROUGH THURSDAY WITH A PERIOD OF DRY AND
SEASONABLY MILD WEATHER. NEXT FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY WITH A PERIOD OF LIGHT RAIN...POSSIBLY BECOMING HEAVY FOR A
TIME FRIDAY NIGHT WHEN THE UPPER LOW PASSES OVERHEAD WITH
LINGERING SHOWERS SATURDAY. LATEST INDICATIONS SHOW A RETURN OF
DRY WEATHER SUNDAY THROUGH THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...AS OF 09:50 AM PST TUESDAY...THE MAIN RAIN BAND
PRODUCING MODERATE TO HEAVY RAIN CONTINUES TO SHIFT SOUTHWARD
THROUGH THE SOUTH BAY AND MONTEREY BAY REGION AT THIS HOUR.
RAINFALL RATES HAVE BEEN UPWARD OF 3/4" PER HOUR IN THE COASTAL
RANGES WITH 1/10" TO 1/4" FOR URBAN AREAS. FURTHER NORTH AND BACK
BEHIND THE BOUNDARY, ISOLATED TO SCATTERED SHOWERS WILL REMAIN
POSSIBLE THROUGH THE MORNING. OVERALL, EXPECTING CONDITIONS TO
CLEAR FROM NORTH TO SOUTH THROUGH THE AFTERNOON. UPDATED SHORT-
TERM FORECAST HAS BEEN SENT. PLEASE SEE PREVIOUS DISCUSSION FOR
MORE DETAILS ON THE EXTENDED FORECAST PERIOD.
&&
.PREV DISCUSSION...AS OF 3:52 AM PST TUESDAY...INITIAL RAIN BAND
IS MOVING ONSHORE AS OF THIS WRITING...MAINLY ARRIVING FROM THE
WEST WITH RAIN DEVELOPING OVER MOST OF THE DISTRICT. AMOUNTS SO
FAR HAVE BEEN LIGHT BUT THAT SHOULD CHANGE QUICKLY OVER THE NEXT
SEVERAL HOURS THAT WILL ENCOMPASS THE MORNING COMMUTE. SATELLITE
IMAGERY SHOWS RAPIDLY COOLING CLOUD TOPS OFFSHORE WITH INCOMING
JET STREAK AND ASSOCIATED SHORTWAVE. AMSU TPW SHOWS GOOD MOISTURE
TAP BUT BEST PLUME OF 1.5 TPW MAY STAY JUST OFFSHORE. LATEST
OBSERVED TRENDS SUGGESTS THAT SOME OF THE HEAVIEST RAIN MAY NOW
SHIFT SLIGHTLY SOUTHWARD AND IMPACT THE SANTA CRUZ MTNS AND SANTA
LUCIA RANGE ABOVE BIG SUR. THE HRRR AND RAP MESOSCALE/SHORT TERM
MODELS SHOW 3-4 INCHES FOR THE SANTA CRUZ MTNS WITH SOME OF THE
HRRR RUNS IN EXCESS OF 7 INCHES ABOVE BIG SUR...ALL OCCURRING OVER
THE NEXT 8-10 HOURS. WILL BE WATCHING RAIN RATES AND TRENDS
CLOSELY THE NEXT FEW HOURS FOR POSSIBLE URBAN AND SMALL STREAM
FLOOD ADVISORIES THROUGHOUT THE BAY AREA...WITH POSSIBILITY THAT
WARNINGS COULD BE NEEDED FOR THE HILLS ABOVE BIG SUR. UPSHOT IS
THAT THE COMMUTE WILL QUICKLY TURN UGLY FOR THE BAY AREA WITH
HEAVIEST RAINS FROM NOW THROUGH ROUGHLY 18-20Z. SIMILAR TO
YESTERDAYS STORM THE STEADY RAIN SHOULD END ABRUPTLY AROUND MIDDAY
IN THE BAY AREA WHILE HANGING ON LONGER FOR THE CENTRAL COAST.
SHOWERS THIS AFTERNOON BUT EVEN THOSE WILL BE LIMITED WITH SOME
LATE DAY PEAKS OF SUNSHINE. WINDS WITH TODAYS FRONT WILL BE
SOUTHERLY THIS MORNING....STRONGEST ON THE COAST AND OVER THE
OCEAN WITH GUSTS AROUND 30 MPH. WINDS TURN WEST BY MIDDAY BUT
GIVEN THE LACK OF COLD ADVECTION THE WESTERLY WINDS WONT BE TOO
STRONG.
HAVE REMOVED ALL CHANCES OF RAIN FOR THIS EVENING AS THE SYSTEM
WILL QUICKLY MOVE EASTWARD. HIGH PRESSURE BUILDS IN TONIGHT AND
LASTS THROUGH THURSDAY. AIRMASS IS MILD AND EXPECT DAYTIME HIGHS
TO BE COMFORTABLY IN THE 60S MIDWEEK WITH MILD OVERNIGHT LOWS
GENERALLY IN THE 40S.
NEXT FRONT ARRIVES THURSDAY NIGHT. INITIAL BOUNDARY DOESN`T LOOK
TOO IMPRESSIVE WITH SOUTHERLY WINDS NOT-FAVORABLE FOR OROGRAPHICS.
GFS AND ECMWF BOTH SHOW FAIRLY WEAK FRONT MOVING THROUGH TIL
MIDDAY FRIDAY...THEN COLD UPPER TROUGH SHOULD PASS OVER THE REGION
AND ALLOW FOR AN UPTICK IN RAIN SHOWERS AND INTENSITY WITH SHOWERS
LASTING INTO SATURDAY. STILL SEVERAL DAYS OUT SO THAT WILL BECOME
THE FOCUS AFTER TODAYS EVENT.
LATEST MODEL TREND OVER THE LAST 24 HOURS HAS BEEN TO BUILD HIGH
PRESSURE SATURDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK. IN
COORDINATION WITH WFO EUREKA REMOVED NEARLY ALL RAIN CHANCES FOR
THE NORTH BAY AS WELL AS THE REST OF THE DISTRICT AFTER SATURDAY
NIGHT.
HOWEVER MUST POINT OUT THE LONG RANGE GFS CONTINUES TO SHOW
ANOTHER COLD WEST COAST TROUGH AND ASSOCIATED RAIN ARRIVING
SOMETIME AROUND JAN 29TH WITH EXTENDED GFS AND CFS MODELS KEEPING
PATTERN ACTIVE.
&&
.AVIATION...AS OF 9:45 PM PST MONDAY...CLOUDS WILL LOWER AND
BECOMING MORE WIDESPREAD OVERNIGHT AS THE NEXT WEATHER SYSTEM
APPROACHES THE COAST. LOOK FOR MVFR CIGS AND RAIN TO SPREAD FROM
NORTH TO SOUTH BETWEEN 08Z AND 14Z. SOUTH TO SOUTHEAST WINDS WILL
ALSO INCREASE IN THIS TIME PERIOD. A PERIOD OF STRONGER
WINDS...MORE INTENSE PRECIP...AND LOWER CIGS IS LIKELY JUST AHEAD
OF THE FRONT BETWEEN 15Z AND 20Z TUESDAY. PRECIP AND WINDS WILL
TAPER OFF BY LATE TUESDAY AFTERNOON.
VICINITY OF KSFO...VFR CIGS SHOULD CONTINUE THROUGH AT LEAST
MIDNIGHT BUT THEN MVFR CIGS SHOULD DEVELOP BY 11Z WHEN PRECIP
BEGINS. FROM ABOUT 15Z TO 19Z EXPECT PRECIP TO INCREASE IN
INTENSITY...SOUTHEAST WINDS TO INCREASE...AND CIGS TO LOWER
FURTHER. FRONTAL PASSAGE EXPECTED AROUND 19Z ON TUESDAY. SHOWERS
MAY LINGER FOR A FEW HOURS AFTER FRONTAL PASSAGE THROUGH MID
AFTERNOON TUESDAY. WINDS WILL REMAIN GUSTY FROM THE SOUTHWEST BUT
GRADUALLY DECREASE BY LATE AFTERNOON.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR THROUGH LATE EVENING EXCEPT
PATCHY LIFR CONDITIONS IN FOG. THEN MVFR CIGS LIKELY DEVELOPING
BY 09Z. GIGS WILL LOWER BY 14Z TUESDAY MORNING AS PRECIP BEGINS.
EXPECT HEAVIEST PRECIP...STRONGEST SOUTHEAST WINDS...AND MOST
INTENSE PRECIP BETWEEN ABOUT 16Z AND 20Z ON TUESDAY. AFTER FRONTAL
PASSAGE EARLY TUESDAY AFTERNOON...LOOK FOR SCATTERED SHOWERS FOR A
FEW HOURS ALONG WITH GRADUALLY DECREASING SOUTHWEST WINDS.
&&
.MARINE...AS OF 09:50 AM PST TUESDAY...STRONG AND GUSTY WINDS
WILL PREVAIL TODAY AS A STORM SYSTEM PASSING THROUGH THE REGION.
WINDS WILL DECREASE RAPIDLY THIS EVENING AFTER THE STORM PASSES.
ANOTHER STORM WILL BRING INCREASING WINDS AGAIN BY FRIDAY. A LONG
PERIOD LARGE SWELL IS FORECAST TO IMPACT THE REGION LATER THIS
WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...SF BAY UNTIL 3 PM
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 3 PM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 3 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 3 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM
SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM
&&
$$
PUBLIC FORECAST: RGASS
AVIATION: W PI
MARINE: MM
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AREA FORECAST DISCUSSION
NWS MIAMI FL
1232 PM EST TUE JAN 19 2016
.AVIATION...
VFR WILL CONTINUE THROUGH THE PERIOD WITH SCT-BKN MID TO HIGH
LEVEL CLOUDINESS...BUT WITH NO RAIN. WINDS WILL PREVAIL OUT OF
THE N-NW NEAR 10 KT AT THE EAST COAST TERMINALS...THEN ARE
FORECAST TO BECOME N-NE LATE IN THE DAY BEFORE LIKELY TURNING BACK
TO THE NNW THIS EVENING/OVERNIGHT. FOR KAPF...N-NE WINDS 5-10 KT
WILL PREVAIL THROUGH THE PERIOD. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 1002 AM EST TUE JAN 19 2016/
UPDATE...
A CHILLY MORNING AGAIN ACROSS SOUTH FL WITH LOWS IN THE 50S IN THE
METROPOLITAN AREAS TO THE 40S ACROSS THE INTERIOR. ASIDE FROM
INCREASING CLOUD COVER ESPECIALLY SOUTHERN LOCALES, NO SIGNIFICANT
CHANGES WERE MADE TO THE FORECAST THIS MORNING. DRY AND COOL
CONDITIONS WILL PREVAIL THIS AFTERNOON. PLEASE SEE PREVIOUS
DISCUSSION BELOW FOR FURTHER FORECAST DETAILS. /GREGORIA
PREV DISCUSSION... /ISSUED 627 AM EST TUE JAN 19 2016/
AVIATION...
VFR WILL CONTINUE THROUGH THE PERIOD WITH MID TO HIGH LEVEL
BROKEN CLOUDINESS...BUT WITH NO RAIN. WINDS WILL PREVAIL OUT OF
THE N-NW NEAR 10 KT AT THE EAST COAST TERMINALS...THEN ARE FORECAST
TO BECOME N-NE LATE IN THE DAY. FOR KAPF...N-NE WINDS 5-10 KT WILL
PREVAIL THROUGH THE PERIOD. /GREGORIA
PREV DISCUSSION... /ISSUED 316 AM EST TUE JAN 19 2016/
DISCUSSION...
MODELS REMAIN IN GOOD AGREEMENT WITH HIGH PRESSURE CONTINUING TO
BUILD OVER THE SOUTHEAST UNITED STATES. THERE IS AN AREA OF HIGH
CLOUDS THAT HAS BEEN STREAMING OVER SOUTH FLORIDA SINCE YESTERDAY.
AS A 500MB TROUGH PUSHES EAST OVER THE NEXT DAY, THE HIGH CLOUDS
SHOULD ALSO BEGIN TO EXIT THE REGION. FOR THE MOST PART, DRY
WEATHER FOR THE CWA. THE EXCEPTION IS SOME SHOWER ACTIVITY WELL
OFFSHORE, OVER THE ATLANTIC. THIS LOOKS TO BE ASSOCIATED WITH A
WEAK SURFACE TROUGH. IT IS NOT ANALYZED WELL IN THE SYNOPTIC
MODELS, BUT THE HRRR IS SHOWING IT AND SEEMS TO HAVE A GOOD HANDLE
ON THINGS.
THIS WEAK TROUGH WILL GET PUSH AWAY FROM SOUTH FLORIDA AS HIGH
PRESSURE BUILDS. ALSO, THE WIND WILL FIRST BEGIN TO RELAX THROUGH
THE DAY, THEN BEGIN A TURN TO THE NORTHEAST BY WEDNESDAY MORNING.
HOWEVER, THE AIR MASS WILL REMAIN DRY AND THE WEATHER WILL
CONTINUE TO BE QUIET THROUGH THE MIDDLE OF THE WEAK. THIS AIR MASS
IS ALSO FAIRLY COOL, AND WILL KEEP THE TEMPS ACROSS THE AREA BELOW
NORMAL FOR A FEW DAYS.
AS THE HIGH BUILDS FURTHER TO THE SOUTH, THE WIND WILL TURN MORE
TO THE EAST, PRETTY MUCH BY WEDNESDAY AFTERNOON. THIS WILL BRING
SOME MOISTURE BACK TO THE AREA, AND BEGIN TO MODIFY THE
TEMPERATURES. SO, AFTER A CHILLY START WEDNESDAY MORNING, WHICH
SHOULD SEE LOWS IN THE UPPER 30S WEST OF THE LAKE, LOW 50S OVER
THE SOUTHEAST FLORIDA METRO AREAS, THE AIR MASS WILL BEGIN A
WARMING TREND. HIGHS WEDNESDAY WILL BE AROUND 70, WITH THE
NORTHWEST PORTION OF THE CWA IN THE UPPER 60S AND THE SOUTHEAST
COAST IN THE LOW 70S.
ELSEWHERE ON WEDNESDAY AFTERNOON, A LOW PRESSURE SYSTEM WILL
DEVELOP LEEWARD OF THE ROCKIES, OVER THE HIGH PLAINS. THIS LOW
WILL BE OUR NEXT WEATHER MAKER FOR SOUTH FLORIDA. BY THURSDAY
AFTERNOON, WHICH WILL BE WARMER THAN WEDNESDAY, BUT STILL LOOKS
DRY, THE LOW WILL TRACK INTO THE SOUTHERN MISSISSIPPI VALLEY, BUT
REMAIN NORTH OF THE GULF. THIS WILL BEGIN TO TURN THE WIND MORE TO
THE SOUTH BY FRIDAY MORNING. THIS WILL BRING MOISTURE BACK, AS
WELL AS ALLOW THE AIR MASS TO WARM INTO THE MID TO UPPER 70S. THIS
WILL ALSO BRING OUR NEXT CHANCE FOR SHOWERS AND STORMS FROM
THURSDAY NIGHT, THROUGH FRIDAY, AND EVEN SOME REMNANT SHOWER
ACTIVITY FRIDAY NIGHT INTO SATURDAY MORNING.
FOR THIS NEXT SYSTEM, IT DOES TRACK FURTHER NORTH THAN THE SYSTEM
THIS PAST SUNDAY MORNING. ALSO, MODELS ARE INDICATING THAT THERE
SHOULD BE SHOWER ACTIVITY WELL AHEAD OF THE SYSTEM. THIS COULD
POTENTIALLY REDUCE INSTABILITY AHEAD OF THE COLD FRONT. THE GFS IS
NOT TOO EXCITED ABOUT THE AMOUNT OF CAPE BY FRIDAY MORNING, WITH
ONLY A FEW HUNDRED JOULES FRIDAY AFTERNOON. THERE IS A BROAD JET
STREAK WITH THE RIGHT EXIT QUADRANT IN THE VICINITY, LEADING TO
SOME CONVERGENCE ALOFT IN THIS GENERAL AREA. THE GFS DOES SHOW A
WEAK LOW LEVEL JET AT 850 MB AT ABOUT 40 KTS.SO, THE ELEMENTS JUST
DO NOT LOOK AS THOUGH THEY ARE LINING UP AS THEY DID WITH THE
LATEST SYSTEM. GFS SHOWS THE HELICITY TO BE A MAX OF 100 M^2*S^-2,
JUST AHEAD OF THE FRONT, NOTHING COMPARED TO THE 300-400 VALUES
FROM THE OTHER DAY. STILL, THERE COULD BE SHOWERS AND A FEW
THUNDERSTORMS THAT PRODUCE SOME GUSTY WIND AS THE FRONT PUSHES
THROUGH ON FRIDAY. THERE WILL BE A CONCERN ABOUT THE SUSTAINED,
NON-CONVECTIVE WIND FROM FRIDAY NIGHT THROUGH SATURDAY. MODEL
BLENDS ARE SHOWING WIND OVER THE MARINE AREAS TO BE NEARING 30KTS,
WITH HIGHER GUSTS, AND 15 TO 20 KTS OVER THE MAINLAND. THIS WILL
MEAN THERE WILL BE SOME MARINE CONCERNS FOR THIS PERIOD.
BEHIND THIS FRONT, ANOTHER COOLER AIR MASS WILL SETTLE IN OVER THE
CWA FOR THE REMAINDER OF THE WEEKEND, INTO THE BEGINNING OF NEXT
WEEK, WHICH SHOULD SEE QUIET WEATHER CONDITIONS.
AVIATION...
HIGH PRESSURE IS BUILDING OVER SOUTH FLORIDA. THIS WILL KEEP THE
WEATHER QUIET FOR THE TAF SITES, AS WELL AS VFR CONDITIONS THROUGH
THE TAF PERIOD. EVEN SO, THERE ARE SOME MID AND UPPER LEVEL CLOUDS
THAT ARE GIVING CIGS OF BKN045, AS WELL AS A DECK OF HIGH CLOUDS.
THE WIND WILL CONTINUE OUT OF THE NORTH TO NORTHWEST INTO THE
AFTERNOON, BEFORE TRYING TO TURN TO THE NORTHEAST.
MARINE...
MARINE CONDITIONS ARE HAZARDOUS FOR SMALL CRAFT TODAY. THIS IS DUE
TO A NORTHERLY WIND BETWEEN 15 AND 20 KTS OPPOSING THE GULF
STREAM, CAUSING SEAS OF 7 TO 8 FEET IN THE GULF STREAM. THE WIND
IS FORECAST TO SUBSIDE TONIGHT, WHICH WILL ALLOW SEAS TO SLOWLY
SUBSIDE BY TOMORROW MORNING. THERE IS A SMALL CRAFT ADVISORY OUT
FOR THE ATLANTIC WATERS. THERE IS ALSO AN AREA OF SHOWERS ORIENTED
NORTH SOUTH IN THE OFFSHORE ATLANTIC WATERS THAT SHOULD SLOWLY
SUBSIDE THIS MORNING. A COLD FRONT AT THE END OF THE WEEK WILL
BRING MARINE CONCERNS INTO THE FORECAST ONCE AGAIN. BESIDES
SHOWERS AND THUNDERSTORMS THAT WILL ACCOMPANY A COLD FRONT, THE
SUSTAINED WIND BEHIND THE FRONT FOR FRIDAY NIGHT INTO SATURDAY
WILL BE NEARING 30 KTS. THIS WILL MAKE FOR HAZARDOUS MARINE
CONDITIONS THIS WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 65 53 71 56 / 0 10 10 10
FORT LAUDERDALE 67 54 71 60 / 0 10 0 10
MIAMI 66 55 70 60 / 0 10 0 10
NAPLES 65 43 72 53 / 0 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR AMZ650-651-670-
671.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR GMZ656-
657.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR GMZ676.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
243 PM CST TUE JAN 19 2016
.SYNOPSIS...
ISSUED AT 243 PM CST TUE JAN 19 2016
A SHRTWV TROF ADVECTING THROUGH NW FLOW LEAD TO SNOW ACROSS THE
IOWA AND N MO THIS AFTERNOON. SNOWFALL TOTALS OF 1 TO 4 INCHES
HAVE BEEN REPORTED IN SW IA INTO S CENTRAL IA. THIS FEATURE WILL
MOVE TO THE EAST THROUGH THE REST OF TODAY. AS THE COLUMN BEGINS
TO SATURATE...SNOW WILL OVERSPREAD THE CWA THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 243 PM CST TUE JAN 19 2016
MAIN FORECAST CONCERN FOR THE SHORT TERM IS THE SNOW THIS
AFTERNOON AND INTO THE EVENING. GUIDANCE AND OBSERVATIONAL TRENDS
SUGGESTS THAT HEAVIEST SNOW...4+ INCHES...WILL OCCUR JUST TO THE
SOUTH OF THE CWA. AS A RESULT...UPDATED SNOW TOTALS AND CURRENT
CHANGES TO THE FORECAST WILL RESULT IN THE ADDITION OF MCDONOUGH
COUNTY IN THE WS.Y. THE BEST CHANCE FOR 3+ INCHES WILL BE SOUTH OF
A LINE FROM MACOMB TO KEOSAUQUA.
HIRES GUIDANCE....SPECIFICALLY THE HRRR AND HIRES NMM KEEPS THE
HEAVIEST SNOW TO OUR SOUTH THIS EVENING. THIS LINES UP WITH AN
OMEGA SIGNAL IN THE DGZ AS WELL. IT APPEARS THAT LIGHT SNOW WILL
OVERSPREAD THE AREA FROM WEST TO EAST. NEAR 00Z...AS THE OMEGA
INCREASES ACROSS THE SOUTH...SNOW INTENSITY SHOULD PICK UP. AT
THIS TIME...THE VORT WILL BE QUICKLY MOVING THROUGH LEADING TO A
QUICK END TO THE SNOW FROM WEST TO EAST. THINK THAT MOST OF THE
SNOW WILL BE OVER AOA 06Z WED. A LOOK AT THE FORECAST PLUMES
SUGGESTS THAT THE HIGHEST CONFIDENCE FOR 3+ INCHES WILL BE ACROSS
OUR EXTREME SOUTH. SNOW TOTALS SHOULD RAPIDLY DECREASE AS YOU
MOVE NORTH OF HWY 34 CORRIDOR WITH THE QC SEEING AROUND AN INCH
TOTAL. THIS IS SUPPORTED BY THE HIRES GUIDANCE AND ENSEMBLE
OUTPUT.
PAST THIS..IT LOOKS LIKE SOME OF THE WARMEST TEMPS IN THE PAST
COUPLE OF DAYS WILL BE TOMORROW WITH NO CHANCE OF POPS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 243 PM CST TUE JAN 19 2016
QUIET AND DRY CONDITIONS WILL BE SEEN ACROSS THE AREA WEDNESDAY
NIGHT THROUGH THURSDAY AS HIGH PRESSURE QUICKLY MOVES THROUGH THE
AREA. TEMPERATURES WILL AVERAGE BELOW NORMAL.
ON THURSDAY NIGHT...MAINLY DRY CONDITIONS ARE EXPECTED AS THE HIGH
MOVES INTO THE OHIO VALLEY. A WEAK DISTURBANCE MOVING THROUGH THE
UPPER MIDWEST MAY BRING SOME FLURRIES OR VERY LIGHT SNOW TO THE
HIGHWAY 20 CORRIDOR WEST OF DUBUQUE.
DRY CONDITIONS WILL THEN BE SEEN ACROSS THE AREA ON FRIDAY AS
ANOTHER HIGH PRESSURE BUILDS INTO THE MIDWEST. TEMPERATURES WILL BE
SLIGHTLY BELOW NORMAL.
FRIDAY NIGHT ON...
THE MODEL CONSENSUS HAS DRY CONDITIONS FRIDAY NIGHT THROUGH SUNDAY
AS HIGH PRESSURE MOVES INTO THE OHIO VALLEY. TEMPERATURES WILL
SLOWLY CLIMB TO ABOVE NORMAL ON SUNDAY. ATTENTION THEN TURNS TO A
POTENTIAL STORM SYSTEM.
SUNDAY NIGHT INTO MONDAY THE MODELS DIVERGE ON THEIR RESPECTIVE
SOLUTIONS. THE ECMWF IS DRY BUT THE GEM AND TO A MUCH LESSER EXTENT
THE GFS SUGGEST A WEAK STORM SYSTEM MOVING THROUGH THE AREA. GIVEN
THE CONSIDERABLE DIFFERENCES...THE MODEL CONSENSUS HAS SLIGHT CHANCE
POPS FOR SUNDAY NIGHT AND MONDAY.
MONDAY NIGHT AND TUESDAY THE MODEL CONSENSUS HAS DRY CONDITIONS AS
HIGH PRESSURE BUILDS INTO THE MIDWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1133 AM CST TUE JAN 19 2016
VFR FLIGHT CONDITIONS TO DETERIORATE TO IFR AND POSSIBLY LIFR
WITH SNOW THROUGH THE EXTENDED PERIOD. THE FIRST SIX HOURS LOOK TO
BE VFR TO MVFR WITH SN SNEAKING IN ACROSS THE WEST AT CID.
CID...BRL AND MLI WILL LIKELY SEE ACCUMULATING SN. DO NOT HAVE
HIGH CONFIDENCE THAT DBQ WILL SEE ANY...SO KEPT VCSH. REGARDLESS
AFTER THE SYSTEM EXITS THE AREA THIS EVENING...LINGERING LLVL
MOISTURE WILL CAUSE CIGS AND VSBYS TO DROP IN THE AM. EXPECT IFR
CONDITIONS WITH POSSIBLE LIFR CONDITIONS AROUND 12Z WED.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LEE-VAN
BUREN.
IL...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR HANCOCK-
MCDONOUGH.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
SCOTLAND.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...08
AVIATION...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
1137 AM CST TUE JAN 19 2016
...18Z AVIATION UPDATE...
.UPDATE...
ISSUED AT 1018 AM CST TUE JAN 19 2016
CURRENT RADAR IMAGERY DEPICTS LIGHT SNOW ACROSS WESTERN IOWA
SLOWLY MAKING ITS WAY TO THE EAST. HIRES CAM GUIDANCE...ALONG WITH
THE RAP AND NAM SUGGEST THAT THE BEST FORCING IN THE DGZ OCCURS TO
THE SOUTH OF THE CWA. THIS IS CLOSE TO OUR SOUTHERNMOST TIER OF
COUNTIES. WITH ANY SMALL DIFFERENCES TO THIS TRACK...OUR SOUTHERN
COUNTIES COULD SEE EITHER MORE SNOW OR LESS SNOW. THIS...ALONG
WITH TIMING DURING THE RUSH HOUR IS ENOUGH TO WARRANT THE
ADVISORY STAYING IN THE SOUTH. NO CHANGES...OTHER THAN TIMING OF
PRECIP ONSET HAVE BEEN MADE.
&&
.SYNOPSIS...
ISSUED AT 345 AM CST TUE JAN 19 2016
LATEST ANALYSIS AT 2 AM SHOWS BEGINNINGS OF LIGHT SNOW DEVELOPING
IN NEBRASKA THAT IS A BIT TOO FAR NORTH OF MOST SOLUTIONS AND ALSO
A BIT SLOWER. SIGNIFICANT MID LEVEL CLOUDS ARE JUST TO THE SOUTHWEST
OF THE FORECAST AREA AND SHOULD OVERSPREAD MOST OF THE REGION BY
DAWN. AREA TEMPERATURES APPEAR TO HAVE STALLED AND VERY WELL MAY
BEGIN TO SLOWLY RISE THE NEXT SEVERAL HOURS AS CLOUDS THICKEN.
UPSTREAM ANALYSIS SUGGEST MOST OF ENERGY TO PASS TO THE SOUTH WITH
ALL PRECIPITATION ENDING BY 06Z TONIGHT. THEN SEASONABLY COLD AND
MOSTLY DRY TO DRY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST TUE JAN 19 2016
SHORT TERM FORECAST CONFIDENCE ASSESSMENT...FAIR TO POOR OR BELOW
TO WELL BELOW NORMAL. MAIN ISSUE REMAINS SNOW TOTALS...AS DISCUSSED
PAST 2 DAYS...FORCING IS CLEARLY COMING IN SOUTH WITH IMPACTS TO
SNOW AMOUNTS AND LOWERING OF POPS NORTH/ALONG OF I-80. THIS MAY
STILL BE UNDERDONE. MOST SOLUTIONS TOO LOW CLOUD BASES TO OBSERVATIONS
AND TOO MUCH COVERAGE OF PRECIPITATION AND TOO FAR DISPLACED NORTH
MAKES THIS QUESTION LIKELY TO BE RESOLVED IN THE NEXT 6 TO 8 HOURS
OF EVEN LOWER AMOUNTS AND FURTHER SOUTH TRACK OF HEAVIER SNOW TOTALS.
TODAY...HAVE DELAYED AND LOWERED POPS WITH RISK POPS ARE STILL A BIT
TOO FAST BY COUPLE HOURS. HAVE TRIMMED QPF AND SNOW TOTALS BY 30+ PERCENT
NORTH HALF AND 20 TO 30 PERCENT SOUTH HALF. TRENDS SUGGEST THIS MAY
STILL NEED LOWERING BY SIMILAR PERCENTAGES FOR DAY SHIFT. MINOR CHANGES
TO HIGHS BETWEEN 12 NORTH TO AROUND 20 DEGREES SOUTH. SINCE ALREADY
HAVE A WINTER WEATHER ADVISORY FAR SW...WILL NOT CANCEL AT THIS TIME...BUT
THIS HEADLINE MAY BE DEEMED NOT NEEDED FOR AT LEAST SOME COUNTIES BY
LATE MORNING. ANY ACCUMULATING SNOWS LIKELY TO ARRIVE FAR SW SECTIONS
AROUND NOON. RAIN/SNOW RATIOS SUGGESTED TO BE AROUND 15-18 TO 1 SOUTH
TO 18 TO 20+ TO 1 FAR NORTH. WIND SHOULD NOT BE A FACTOR WITH 5 TO 10
MPH OUT OF THE SOUTHEAST TO RESULT IN NO DRIFTING ISSUES WHERE ACCUMULATING
SNOW FALL.
TONIGHT...AGAIN LOWERED AMOUNTS IN EVENING BY AROUND 30 PERCENT NORTH
HALF AND 20 TO 30 SOUTH HALF. SNOW TOTALS FOR THIS EVENT SHOULD RANGE
FROM A HALF INCH OR LESS ALONG AND NORTH OF HIGHWAY 30. BETWEEN A HALF
INCH TO 1.5 INCHES FROM HIGHWAY 30 TO HIGHWAY 34. THE LOCATIONS VERY
CLOSE TO MISSOURI BORDER AND SOUTH ARE MOST LIKELY TO SEE 2+ INCHES
WITH LOCALLY 3 TO 4 INCHES POSSIBLE. AGAIN...TRENDS DO SUGGEST ANY
3 PLUS INCHES MAY SLIDE A BIT FURTHER SOUTH OUT OF THE FORECAST AREA
WHICH SHOULD BE KNOWN BY NLT LATE MORNING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 AM CST TUE JAN 19 2016
FORECAST CONCERNS TODAY ARE FOCUSED ON TEMPERATURES WITH NO MAJOR
SYSTEMS LOOKING TO IMPACT THE LOCAL AREA THROUGH THE NEXT WEEK.
MODELS ARE IN GOOD AGREEMENT WHEN LOOKING AT THE LARGE SCALE PATTERN
SO CONFIDENCE IS FAIRLY DECENT IN THE FORECAST. THAT BEING
SAID...MINOR DISCREPANCIES IN DETAILS IN THE MODELS LEAD TO SOME
UNCERTAINTY ON TEMPERATURES THROUGHOUT THE WEEK.
BEGINNING ON WEDNESDAY...THE MID-LEVEL SHORTWAVE TROUGH THAT WILL
BRING THE SNOW TO THE AREA THROUGH TONIGHT SHOULD BE EXITING THE
REGION WITH NO ACCUMULATING SNOW EXPECTED ANYWHERE ACROSS THE AREA
AFTER 12Z. FORECAST SOUNDINGS DO SHOW A RATHER THICK STRATUS LAYER
REMAINING OVER THE AREA IN THE WAKE OF THIS SYSTEM. DID CONTEMPLATE
ADDING IN MENTION OF FLURRIES FOR WEDNESDAY MORNING AS SATURATION
EXTENDS FROM THE SURFACE UP THROUGH AROUND 7K FEET...WHILE THIS
LAYER LOOKS TO BE NEARLY ISOTHERMAL VERY NEAR -12C TO BE COLD ENOUGH
FOR FLURRIES RATHER THAN ANY DRIZZLE. THE LIFT SEEN IN THIS LAYER IS
VERY WEAK THOUGH SO HELD OFF INCLUDING FLURRIES IN THE FORECAST.
WARM AIR ADVECTION WILL BE ONGOING THROUGH THE DAY WEDNESDAY AS
850MB TEMPERATURES WILL IMPROVE SIGNIFICANTLY. AFTER LOOKING TO BE
FROM 08C TO 12C ACROSS THE FORECAST AREA AT 12Z...THE WARMING LOOKS
TO BRING THE AREA TO A RANGE FROM NEAR 0C TO 08C BY 21/00Z. DESPITE
THE WARMING...BELIEVE THE THICK CLOUDS WILL STAY OVER THE AREA
THROUGH MUCH OF THE DAY SO WENT A BIT COOLER FOR HIGHS
WEDNESDAY...IN THE 20S. THE FORECAST IS EXPECTING THE CLOUDS TO
STICK AROUND WEDNESDAY NIGHT...WHICH WILL HELP KEEP TEMPERATURES
FROM FALLING TOO FAR DESPITE PRETTY LIGHT WINDS.
THERE IS A SYSTEM CURRENTLY OFF THE PACIFIC COAST...WHICH WILL MOVE
ONSHORE TONIGHT AND MOVE INTO THE CENTRAL PLAINS THROUGH WEDNESDAY
NIGHT. THE MODELS CONTINUE TO KEEP THIS SYSTEM WELL SOUTH OF THE
AREA SO HAVE HIGH CONFIDENCE ON THE DRY FORECAST FOR
THURSDAY/THURSDAY NIGHT. WITH THE SYSTEM STAYING SOUTH OF THE LOCAL
AREA...COLDER AIR WILL TAKE RESIDENCE FOR A SHORT PERIOD OF TIME.
COLDER BEING A RELATIVE TERM AS 850MB TEMPERATURES BOTTOM OUT AROUND
-9C WHICH IS WELL WARMER THAN WHAT WE HAVE BEEN EXPERIENCING THE
PAST FEW DAYS /DOWN TO NEAR -22C. DETAILS IN THE MODELS ARE GIVING
AN UNCLEAR SIGNAL OF WHERE TEMPERATURES WILL END UP THURSDAY AND
FRIDAY. USED A GENERAL BLEND FROM THE GUIDANCE...AND HAVE HIGHS IN
THE MID 20S...TO LOW 30S. RIDGING BUILDS INTO THE REGION FOR THE
WEEKEND WITH TEMPERATURES MODERATING TO ABOVE FREEZING ACROSS THE
ENTIRE FORECAST AREA BY SUNDAY. THE SOUTHERN PORTIONS OF THE
FORECAST AREA MAY EVEN GET CLOSE TO 40. THERE HAS BEEN A WEAK SIGNAL
IN THE PAST FEW MODEL RUNS OF LIGHT PRECIPITATION SUNDAY AND SUNDAY
NIGHT AS A WEAK SHORTWAVE MOVES INTO THE AREA...BUT THE TREND HAS
BEEN WEAKER WITH THIS SIGNAL AS DAYS HAVE PASSED SO PRECIPITATION
TRENDS HAVE BEEN TO GO LOWER AND THIS TREND CONTINUED FOR THIS
FORECAST CYCLE. A BETTER CHANCE FOR PRECIPITATION IS LOOKING TO COME
ON MONDAY...YET THERE ARE FAIRLY SIGNIFICANT DIFFERENCES BETWEEN THE
LONG RANGE MODELS WITH THE TIMING AND LOCATION OF THIS SYSTEM AS IT
MOVES ACROSS THE CENTRAL PART OF THE COUNTRY SO PRECIPITATION
CHANCES FOR THE MONDAY TIME-FRAME WILL LIKELY BE CHANGING IN LATER
FORECASTS AS THIS BECOMES MORE CLEAR. THAT BEING SAID...THIS WOULD
BE A LIGHT PRECIPITATION EVENT SO NO MAJOR SNOW OR RAIN AMOUNTS ARE
EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1133 AM CST TUE JAN 19 2016
VFR FLIGHT CONDITIONS TO DETERIORATE TO IFR AND POSSIBLY LIFR
WITH SNOW THROUGH THE EXTENDED PERIOD. THE FIRST SIX HOURS LOOK TO
BE VFR TO MVFR WITH SN SNEAKING IN ACROSS THE WEST AT CID.
CID...BRL AND MLI WILL LIKELY SEE ACCUMULATING SN. DO NOT HAVE
HIGH CONFIDENCE THAT DBQ WILL SEE ANY...SO KEPT VCSH. REGARDLESS
AFTER THE SYSTEM EXITS THE AREA THIS EVENING...LINGERING LLVL
MOISTURE WILL CAUSE CIGS AND VSBYS TO DROP IN THE AM. EXPECT IFR
CONDITIONS WITH POSSIBLE LIFR CONDITIONS AROUND 12Z WED.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LEE-VAN
BUREN.
IL...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR HANCOCK.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
SCOTLAND.
&&
$$
UPDATE...GIBBS
SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...BROOKS
AVIATION...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
1019 AM CST TUE JAN 19 2016
.UPDATE...
ISSUED AT 1018 AM CST TUE JAN 19 2016
CURRENT RADAR IMAGERY DEPICTS LIGHT SNOW ACROSS WESTERN IOWA
SLOWLY MAKING ITS WAY TO THE EAST. HIRES CAM GUIDANCE...ALONG WITH
THE RAP AND NAM SUGGEST THAT THE BEST FORCING IN THE DGZ OCCURS TO
THE SOUTH OF THE CWA. THIS IS CLOSE TO OUR SOUTHERNMOST TIER OF
COUNTIES. WITH ANY SMALL DIFFERENCES TO THIS TRACK...OUR SOUTHERN
COUNTIES COULD SEE EITHER MORE SNOW OR LESS SNOW. THIS...ALONG
WITH TIMING DURING THE RUSH HOUR IS ENOUGH TO WARRANT THE
ADVISORY STAYING IN THE SOUTH. NO CHANGES...OTHER THAN TIMING OF
PRECIP ONSET HAVE BEEN MADE.
&&
.SYNOPSIS...
ISSUED AT 345 AM CST TUE JAN 19 2016
LATEST ANALYSIS AT 2 AM SHOWS BEGINNINGS OF LIGHT SNOW DEVELOPING
IN NEBRASKA THAT IS A BIT TOO FAR NORTH OF MOST SOLUTIONS AND ALSO
A BIT SLOWER. SIGNIFICANT MID LEVEL CLOUDS ARE JUST TO THE SOUTHWEST
OF THE FORECAST AREA AND SHOULD OVERSPREAD MOST OF THE REGION BY
DAWN. AREA TEMPERATURES APPEAR TO HAVE STALLED AND VERY WELL MAY
BEGIN TO SLOWLY RISE THE NEXT SEVERAL HOURS AS CLOUDS THICKEN.
UPSTREAM ANALYSIS SUGGEST MOST OF ENERGY TO PASS TO THE SOUTH WITH
ALL PRECIPITATION ENDING BY 06Z TONIGHT. THEN SEASONABLY COLD AND
MOSTLY DRY TO DRY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST TUE JAN 19 2016
SHORT TERM FORECAST CONFIDENCE ASSESSMENT...FAIR TO POOR OR BELOW
TO WELL BELOW NORMAL. MAIN ISSUE REMAINS SNOW TOTALS...AS DISCUSSED
PAST 2 DAYS...FORCING IS CLEARLY COMING IN SOUTH WITH IMPACTS TO
SNOW AMOUNTS AND LOWERING OF POPS NORTH/ALONG OF I-80. THIS MAY
STILL BE UNDERDONE. MOST SOLUTIONS TOO LOW CLOUD BASES TO OBSERVATIONS
AND TOO MUCH COVERAGE OF PRECIPITATION AND TOO FAR DISPLACED NORTH
MAKES THIS QUESTION LIKELY TO BE RESOLVED IN THE NEXT 6 TO 8 HOURS
OF EVEN LOWER AMOUNTS AND FURTHER SOUTH TRACK OF HEAVIER SNOW TOTALS.
TODAY...HAVE DELAYED AND LOWERED POPS WITH RISK POPS ARE STILL A BIT
TOO FAST BY COUPLE HOURS. HAVE TRIMMED QPF AND SNOW TOTALS BY 30+ PERCENT
NORTH HALF AND 20 TO 30 PERCENT SOUTH HALF. TRENDS SUGGEST THIS MAY
STILL NEED LOWERING BY SIMILAR PERCENTAGES FOR DAY SHIFT. MINOR CHANGES
TO HIGHS BETWEEN 12 NORTH TO AROUND 20 DEGREES SOUTH. SINCE ALREADY
HAVE A WINTER WEATHER ADVISORY FAR SW...WILL NOT CANCEL AT THIS TIME...BUT
THIS HEADLINE MAY BE DEEMED NOT NEEDED FOR AT LEAST SOME COUNTIES BY
LATE MORNING. ANY ACCUMULATING SNOWS LIKELY TO ARRIVE FAR SW SECTIONS
AROUND NOON. RAIN/SNOW RATIOS SUGGESTED TO BE AROUND 15-18 TO 1 SOUTH
TO 18 TO 20+ TO 1 FAR NORTH. WIND SHOULD NOT BE A FACTOR WITH 5 TO 10
MPH OUT OF THE SOUTHEAST TO RESULT IN NO DRIFTING ISSUES WHERE ACCUMULATING
SNOW FALL.
TONIGHT...AGAIN LOWERED AMOUNTS IN EVENING BY AROUND 30 PERCENT NORTH
HALF AND 20 TO 30 SOUTH HALF. SNOW TOTALS FOR THIS EVENT SHOULD RANGE
FROM A HALF INCH OR LESS ALONG AND NORTH OF HIGHWAY 30. BETWEEN A HALF
INCH TO 1.5 INCHES FROM HIGHWAY 30 TO HIGHWAY 34. THE LOCATIONS VERY
CLOSE TO MISSOURI BORDER AND SOUTH ARE MOST LIKELY TO SEE 2+ INCHES
WITH LOCALLY 3 TO 4 INCHES POSSIBLE. AGAIN...TRENDS DO SUGGEST ANY
3 PLUS INCHES MAY SLIDE A BIT FURTHER SOUTH OUT OF THE FORECAST AREA
WHICH SHOULD BE KNOWN BY NLT LATE MORNING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 AM CST TUE JAN 19 2016
FORECAST CONCERNS TODAY ARE FOCUSED ON TEMPERATURES WITH NO MAJOR
SYSTEMS LOOKING TO IMPACT THE LOCAL AREA THROUGH THE NEXT WEEK.
MODELS ARE IN GOOD AGREEMENT WHEN LOOKING AT THE LARGE SCALE PATTERN
SO CONFIDENCE IS FAIRLY DECENT IN THE FORECAST. THAT BEING
SAID...MINOR DISCREPANCIES IN DETAILS IN THE MODELS LEAD TO SOME
UNCERTAINTY ON TEMPERATURES THROUGHOUT THE WEEK.
BEGINNING ON WEDNESDAY...THE MID-LEVEL SHORTWAVE TROUGH THAT WILL
BRING THE SNOW TO THE AREA THROUGH TONIGHT SHOULD BE EXITING THE
REGION WITH NO ACCUMULATING SNOW EXPECTED ANYWHERE ACROSS THE AREA
AFTER 12Z. FORECAST SOUNDINGS DO SHOW A RATHER THICK STRATUS LAYER
REMAINING OVER THE AREA IN THE WAKE OF THIS SYSTEM. DID CONTEMPLATE
ADDING IN MENTION OF FLURRIES FOR WEDNESDAY MORNING AS SATURATION
EXTENDS FROM THE SURFACE UP THROUGH AROUND 7K FEET...WHILE THIS
LAYER LOOKS TO BE NEARLY ISOTHERMAL VERY NEAR -12C TO BE COLD ENOUGH
FOR FLURRIES RATHER THAN ANY DRIZZLE. THE LIFT SEEN IN THIS LAYER IS
VERY WEAK THOUGH SO HELD OFF INCLUDING FLURRIES IN THE FORECAST.
WARM AIR ADVECTION WILL BE ONGOING THROUGH THE DAY WEDNESDAY AS
850MB TEMPERATURES WILL IMPROVE SIGNIFICANTLY. AFTER LOOKING TO BE
FROM 08C TO 12C ACROSS THE FORECAST AREA AT 12Z...THE WARMING LOOKS
TO BRING THE AREA TO A RANGE FROM NEAR 0C TO 08C BY 21/00Z. DESPITE
THE WARMING...BELIEVE THE THICK CLOUDS WILL STAY OVER THE AREA
THROUGH MUCH OF THE DAY SO WENT A BIT COOLER FOR HIGHS
WEDNESDAY...IN THE 20S. THE FORECAST IS EXPECTING THE CLOUDS TO
STICK AROUND WEDNESDAY NIGHT...WHICH WILL HELP KEEP TEMPERATURES
FROM FALLING TOO FAR DESPITE PRETTY LIGHT WINDS.
THERE IS A SYSTEM CURRENTLY OFF THE PACIFIC COAST...WHICH WILL MOVE
ONSHORE TONIGHT AND MOVE INTO THE CENTRAL PLAINS THROUGH WEDNESDAY
NIGHT. THE MODELS CONTINUE TO KEEP THIS SYSTEM WELL SOUTH OF THE
AREA SO HAVE HIGH CONFIDENCE ON THE DRY FORECAST FOR
THURSDAY/THURSDAY NIGHT. WITH THE SYSTEM STAYING SOUTH OF THE LOCAL
AREA...COLDER AIR WILL TAKE RESIDENCE FOR A SHORT PERIOD OF TIME.
COLDER BEING A RELATIVE TERM AS 850MB TEMPERATURES BOTTOM OUT AROUND
-9C WHICH IS WELL WARMER THAN WHAT WE HAVE BEEN EXPERIENCING THE
PAST FEW DAYS /DOWN TO NEAR -22C. DETAILS IN THE MODELS ARE GIVING
AN UNCLEAR SIGNAL OF WHERE TEMPERATURES WILL END UP THURSDAY AND
FRIDAY. USED A GENERAL BLEND FROM THE GUIDANCE...AND HAVE HIGHS IN
THE MID 20S...TO LOW 30S. RIDGING BUILDS INTO THE REGION FOR THE
WEEKEND WITH TEMPERATURES MODERATING TO ABOVE FREEZING ACROSS THE
ENTIRE FORECAST AREA BY SUNDAY. THE SOUTHERN PORTIONS OF THE
FORECAST AREA MAY EVEN GET CLOSE TO 40. THERE HAS BEEN A WEAK SIGNAL
IN THE PAST FEW MODEL RUNS OF LIGHT PRECIPITATION SUNDAY AND SUNDAY
NIGHT AS A WEAK SHORTWAVE MOVES INTO THE AREA...BUT THE TREND HAS
BEEN WEAKER WITH THIS SIGNAL AS DAYS HAVE PASSED SO PRECIPITATION
TRENDS HAVE BEEN TO GO LOWER AND THIS TREND CONTINUED FOR THIS
FORECAST CYCLE. A BETTER CHANCE FOR PRECIPITATION IS LOOKING TO COME
ON MONDAY...YET THERE ARE FAIRLY SIGNIFICANT DIFFERENCES BETWEEN THE
LONG RANGE MODELS WITH THE TIMING AND LOCATION OF THIS SYSTEM AS IT
MOVES ACROSS THE CENTRAL PART OF THE COUNTRY SO PRECIPITATION
CHANCES FOR THE MONDAY TIME-FRAME WILL LIKELY BE CHANGING IN LATER
FORECASTS AS THIS BECOMES MORE CLEAR. THAT BEING SAID...THIS WOULD
BE A LIGHT PRECIPITATION EVENT SO NO MAJOR SNOW OR RAIN AMOUNTS ARE
EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 537 AM CST TUE JAN 19 2016
CLOUDS WILL THICKEN AND LOWER THROUGH THE DAY WITH MVFR CONDITIONS
POSSIBLE AT BRL TERMINAL IN LIGHT SNOW BY 19/21Z DUE TO SNOW. THE
REMAINING TERMINALS WILL BECOME MVFR BY 20/03Z DUE TO RISK OF LIGHT
SNOW AND ALSO LOWERING CLOUDS. IFR CONDITIONS MAY BE POSSIBLE AT
ALL THE TERMINALS DUE TO LOW CLOUDS AND FOG AFTER 20/09Z.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LEE-VAN
BUREN.
IL...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR HANCOCK.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
SCOTLAND.
&&
$$
UPDATE...GIBBS
SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...BROOKS
AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
251 PM MST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 210 PM MST TUE JAN 19 2016
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS SHOWS RIDGING ACROSS THE
ROCKIES WITH A SHORTWAVE TROUGH TRANSITIONING OUT OF THE PLAINS
TOWARDS THE CENTRAL MISSISSIPPI RIVER VALLEY. ANOTHER SHORTWAVE
TROUGH UPSTREAM OF THE RIDGE IS MOVING INTO THE PACIFIC NORTHWEST
WITH A MUCH STRONGER WEST-EAST ORIENTATED UPPER LEVEL JET OVER
NORTHERN CALIFORNIA. AT THE SURFACE LEE TROUGH HAS DEVELOPED OVER
EAST CENTRAL COLORADO (NEAR FRONT RANGE) AND WARM FRONT IS IN THE
PROCESS OF LIFTING OVER THE NORTHEAST PART OF OUR CWA (FROM KMCK TO
KHLC). PERSISTENT STRATUS IS STILL IN PLACE IN OUR EASTERN CWA WITH
CLOUD SHIELD BREAKING UP IN THE WEST.
THIS EVENING-WEDNESDAY MORNING...MAIN CONCERN WILL FOCUS ON POSSIBLE
DENSE FOG DEVELOPMENT THIS EVENING/OVERNIGHT. MODELS SUPPORT LEE
TROUGH SHIFTING EASTWARD WITH SOUTHERLY FLOW QUICKLY DEVELOPING
AFTER SUNSET. THIS SHOULD HELP ADVECT GOOD BL MOISTURE BACK INTO OUR
CWA AND STRATUS IN THE EAST COULD THEN EXPAND WESTWARD. EARLIER
HRRR/RAP SUPPORTED FOG REDEVELOPING AFTER 00Z THIS EVENING NEAR THE
CO/KS BORDER AND SPREADING EASTWARD. LATEST SREF/NAM/RAP/HRRR NOW
SHOWING STRONGER SIGNAL AFTER MIDNIGHT TONIGHT THROUGH EARLY
WEDNESDAY MORNING WITH MAIN FOG AXIS SHIFTED FURTHER EAST (TOWARD
BACK EDGE OF CURRENT STRATUS DECK). I KEPT FOG COVERAGE/TIMING
SIMILAR TO EARLY GUIDANCE COVER POSSIBILITY...HOWEVER CONFIDENCE AT
THIS POINT IS SIGNIFICANTLY LOWER ON WHERE OR IF DENSE FOG MAY
DEVELOP OVER OUR CWA. (FOG MAY BE A GOOD BET BUT DENSE FOG MAY BE
PATCHY).
WEDNESDAY...TWO SHORTWAVES ARE EXPECTED TO MOVE ACROSS THE ROCKIES
AND OVER OUR CWA WITH THE FIRST (WEAKER) SHORTWAVE MOVING OVER OUR
CWA MIDDAY WEDNESDAY. AS WAS INDICATED IN EARLIER GUIDANCE ON MID
SHIFT THERE IS A SIGNIFICANT DRY LAYER FROM ABOVE THE BL TO 600-
700MB. DESPITE FORCING THIS LOWERS CONFIDENCE IN ANY MEASURABLE
PRECIP DURING THE DAY WEDNESDAY. BY LATE WEDNESDAY AFTERNOON THE
SECOND (STRONGER) SHORTWAVE TROUGH DIGS SOUTHEAST AND OVERTAKES THE
FIRST TROUGH WITH A STRONGER UPPER LEVEL JET BEGINNING TO DEVELOP.
BY LATE AFTERNOON THERE IS A WEAK PRECIP SIGNAL IN OUR FAR EASTERN
CWA AND GUIDANCE THERE DOES SHOW SOME MOISTENING OF THE MOISTURE
PROFILE. I KEPT SMALL AREA OF SLIGHT CHANCE POPS IN GRAHAM/NORTON
COUNTIES TO MATCH THIS...BUT CONFIDENCE IS STILL NOT HIGH THAT
THINGS WOULD START THIS EARLY.
OTHER CONCERN FOR WEDNESDAY WILL BE HIGHS. POTENTIAL EXISTS AGAIN
FOR LINGERING STRATUS...HOWEVER WITH TROUGHS MOVING THROUGH THE
REGION THICK/OPAQUE MID-HIGH CLOUD COVER COULD ALSO LIMIT DIURNAL
HEATING. I LOWERED HIGHS IN THE EAST FROM PREVIOUS FORECAST DUE TO
POTENTIAL IMPACTS OF CLOUD COVER. TOUGH CALL AND IF WE WERE TO
CLEAR OUT (MORE LIKELY IN THE WEST) WE COULD SEE HIGHS IN THE
UPPER 40S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 248 PM MST TUE JAN 19 2016
FORECAST ISSUES WILL BE CHANCE OF PRECIPITATION AND PHASE OF
PRECIPITATION WEDNESDAY NIGHT INTO THURSDAY. SATELLITE SHOWING A
SOMEWHAT AMPLIFIED BUT STILL PROGRESSIVE AND ACTIVE FLOW PATTERN
FROM THE PACIFIC INTO THE WESTERN ATLANTIC. LARGE AND COMPLICATED
UPPER TROUGH IS OVER THE NORTHEAST PACIFIC.
AT JET LEVEL...THE MODELS WERE HAVING A LITTLE TROUBLE WITH THE JET
ALONG THE WEST COAST. AT MID LEVELS...MODELS WERE ALL ABOUT THE SAME
BUT THEY WERE ALSO A LITTLE FAR EAST/FAST WITH THE UPPER TROUGH NOW
COMING ON THE COAST. THE NAM/ECMWF WAS DOING THE BEST ON THE SURFACE
WIND AND PRESSURE FIELD. THE GFS AND CANADIAN WERE DOING THE BEST ON
THE LOW LEVEL THERMAL FIELD WITH MOST MODELS NOT BEING COLD ENOUGH.
WEDNESDAY NIGHT...DEVELOPING PRECIPITATION EVENT IS IN ITS BEGINNING
STAGES. MODELS DIFFERENT ON SPEED...POSITION AND AMPLITUDE OF MID
LEVEL CIRCULATION THAT APPEARS TO BE DEVELOPING ON TOP OF US OR JUST
TO THE EAST OF US. TODAYS MODEL RUNS VERY DIFFERENT THAN 24 HOURS
AGO. BY THE BEGINNING OF THIS PERIOD...MODELS STILL HAVE STRONG
NORTH TO SOUTH JET ON THE WEST SIDE OF THIS UPPER SYSTEM.
THIS COMBINED WITH THE PROBLEM OF THE MODELS INITIALLY HAVING THIS
SYSTEM TOO FAR EAST THIS MORNING...LEADS ME TO BELIEVE THAT WHATEVER
ENDS UP BEING THE SLOWER AND EVEN FURTHER SOUTH SOLUTION WILL END UP
BEING MORE RIGHT. EVEN NOW AM THINKING CURRENT MODEL RUN STILL MAY
BE TOO FAST/FAR NORTH. TROUGH IS ELONGATED AND COMPROMISED OF A
NORTHERN AND SOUTHERN CIRCULATIONS WITHIN THIS TROUGH. PAST
EXPERIENCE HAS SHOWN THIS SETUP IS NOT GREAT FOR A LOT OF
PRECIPITATION.
SAYING ALL THAT...THE FAR EASTERN PORTION OF THE AREA WILL HAVE THE
BEST CHANCE WITH BEST CHANCE OVERALL AT THIS TIME BEING TO THE EAST
OF OUR AREA. THE GRADIENT OF THE CHANCE OF PRECIPITATION WILL BE
REALLY SHARP. PER THE REASONING ABOVE...AM THINKING THAT THE BEST
CHANCE OF PRECIPITATION WILL BE AFTER MIDNIGHT AND THAT IS SUPPORTED
BY THE SREF PROBABILITIES. BEST CHANCE WILL BE VERY LATE IN THE
NIGHT.
THERE IS NOT A LOT OF COLD AIR WITH THIS SYSTEM...AND DEPENDING ON
WHICH MODEL YOU CHOOSE THE CHANGE OVER MAY NOT OCCUR UNTIL LATE
EVENING/AROUND MIDNIGHT WITH THE EASTERN AREAS CHANGING OVER FIRST.
THE PHASE IS REALLY WHERE THERE ARE BIG DIFFERENCES. SOME MODELS
KEEPING TOTALLY DRY OR HAVE JUST ENOUGH MOISTURE IN THE LOW LEVELS
FOR DRIZZLE/FREEZING DRIZZLE. SO A LOT OF UNCERTAINTY WITH THIS
SYSTEM.
THURSDAY/THURSDAY NIGHT...WITH THE PROXIMITY OF THE SYSTEM AND
EXPECTED SLOWNESS...ALONG WITH MID AND UPPER LEVEL LIFT
EXPECTED...EXPECT THE BEST CHANCE OF PRECIPITATION WILL BE IN THE
MORNING AND THEN RAPIDLY DECREASE AND END. IF CURRENT FORECAST PANS
OUT...THE FAR EASTERN PORTION OF THE AREA GETS 1 TO 2 INCHES.
GRADIENT AND DOWNWARD MOTION BEHIND THE SYSTEM WILL CREATE BREEZY TO
WINDY CONDITIONS. THE STRONGEST WINDS ARE AFTER THE SNOW ENDS...AND
WITH TEMPERATURES JUST ABOVE FREEZING...DO NOT EXPECT ANY BLOWING
SNOW PROBLEMS AT THIS TIME. CURRENT HIGH TEMPERATURE FORECAST LOOKS
TO BE IN GOOD SHAPE AND MADE ONLY MINOR ADJUSTMENTS. HOWEVER...IF
MORE SNOW THAN EXPECT IT WILL BE COLDER. LIGHT WINDS AND LITTLE
CLOUD COVER WILL ALLOW OVERNIGHT TEMPERATURES TO DROP A DECENT
AMOUNT.
FRIDAY...STRONG MID/UPPER LEVEL RIDGE BUILDS IN OVER THE AREA.
SURFACE WILL MOVE THROUGH AND TO THE EAST OF THE AREA DURING THE
DAY. SO DO EXPECT RECYCLED COOL AIR. THE EASTERN LOCATIONS WILL BE
THE COLDEST AND OVERALL REDUCED THE HIGH TEMPERATURES A LITTLE.
FRIDAY NIGHT THROUGH TUESDAY...MID AND UPPER RIDGE WILL BE IN PLACE
FROM FRIDAY NIGHT INTO SATURDAY NIGHT SO EXPECT MODERATING
TEMPERATURES AND DRY CONDITIONS. THE INIT WAS REASONABLE WITH THIS
AND MADE NO CHANGES.
A STRONG SHORTWAVE TROUGH...NOT UNLIKE THE ONE THAT WENT THROUGH
THIS MORNING AND SIMILAR ALSO THE SYSTEM EXPECTED WEDNESDAY NIGHT
AND THURSDAY...WILL MOVE THROUGH SUNDAY AND SUNDAY NIGHT. THE INIT
PRODUCED SLIGHT CHANCE POPS DURING THIS PERIOD AND SEEMS REASONABLE.
POSSIBLE THAT THESE CHANCES WILL INCREASE. AFTER THAT RIDGING WILL
MOVE INTO THE AREA AND BRING DRY CONDITIONS AND MODERATING
TEMPERATURES ONCE AGAIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1023 AM MST TUE JAN 19 2016
LIGHT SNOW/FLURRIES HAVE TRANSITIONED SOUTHEAST OF BOTH KGLD AND
KMCK TERMINALS WITH IFR CIGS AT KGLD AND MVFR CIGS AT KMCK
LINGERING IN THE EARLY PART OF THE TAF PERIOD. SATELLITE AND
UPSTREAM OBS IN NEBRASKA/COLORADO SUPPORT THIS STRATUS LIFTING
BY THE MIDDLE OF THE AFTERNOON IN LINE WITH SHORT RANGE GUIDANCE.
LEE TROUGH REDEVELOPS THIS EVENING WITH SOUTHERLY RETURN FLOW
BRINGING LOW LEVEL MOISTURE BACK OVER BOTH TERMINALS. THERE IS A
STRONG STRATUS/FOG SIGNAL ON SHORT RANGE GUIDANCE AND ENSEMBLES
AND IT APPEARS LIKELY THAT IFR CIGS/VIS WILL DEVELOP AT KGLD THEN
KMCK LATER. I AM CONCERNED THAT THERE COULD BE A PROLONGED DENSE
FOG EVENT (1/4SM) AT KGLD OR KMCK TONIGHT THROUGH WEDNESDAY
MORNING. CONSENSUS STILL FAVORS PREVAILING VIS AROUND 1SM AT THE
PEAK OF THIS FOG EVENT...SO I WILL HOLD OFF ON LOWER VIS FOR NOW
AS IT MAY END UP BEING MORE OF A TEMPORARY CONDITION IF MODELS
ARE OVERDONE ON COVERAGE AS THEY HAVE BEEN THE LAST FEW DAYS.
CONDITIONS SHOULD CLEAR AS A SERIES OF LARGE SCALE DISTURBANCES
MOVE INTO THE REGION WEDNESDAY MORNING INCREASING LOW LEVEL
MIXING. STRATUS/FOG MAY LINGER LONGER AT KMCK...BUT THE TREND
SHOULD BE TOWARDS IMPROVEMENT MID MORNING WEDNESDAY. THERE IS ALSO
THE POSSIBILITY FOR A FEW SNOW SHOWERS OR FLURRIES BEFORE
18Z...HOWEVER CONFIDENCE IS TOO LOW TO ADD DURING THIS UPDATE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
211 PM MST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 210 PM MST TUE JAN 19 2016
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS SHOWS RIDGING ACROSS THE
ROCKIES WITH A SHORTWAVE TROUGH TRANSITIONING OUT OF THE PLAINS
TOWARDS THE CENTRAL MISSISSIPPI RIVER VALLEY. ANOTHER SHORTWAVE
TROUGH UPSTREAM OF THE RIDGE IS MOVING INTO THE PACIFIC NORTHWEST
WITH A MUCH STRONGER WEST-EAST ORIENTATED UPPER LEVEL JET OVER
NORTHERN CALIFORNIA. AT THE SURFACE LEE TROUGH HAS DEVELOPED OVER
EAST CENTRAL COLORADO (NEAR FRONT RANGE) AND WARM FRONT IS IN THE
PROCESS OF LIFTING OVER THE NORTHEAST PART OF OUR CWA (FROM KMCK TO
KHLC). PERSISTENT STRATUS IS STILL IN PLACE IN OUR EASTERN CWA WITH
CLOUD SHIELD BREAKING UP IN THE WEST.
THIS EVENING-WEDNESDAY MORNING...MAIN CONCERN WILL FOCUS ON POSSIBLE
DENSE FOG DEVELOPMENT THIS EVENING/OVERNIGHT. MODELS SUPPORT LEE
TROUGH SHIFTING EASTWARD WITH SOUTHERLY FLOW QUICKLY DEVELOPING
AFTER SUNSET. THIS SHOULD HELP ADVECT GOOD BL MOISTURE BACK INTO OUR
CWA AND STRATUS IN THE EAST COULD THEN EXPAND WESTWARD. EARLIER
HRRR/RAP SUPPORTED FOG REDEVELOPING AFTER 00Z THIS EVENING NEAR THE
CO/KS BORDER AND SPREADING EASTWARD. LATEST SREF/NAM/RAP/HRRR NOW
SHOWING STRONGER SIGNAL AFTER MIDNIGHT TONIGHT THROUGH EARLY
WEDNESDAY MORNING WITH MAIN FOG AXIS SHIFTED FURTHER EAST (TOWARD
BACK EDGE OF CURRENT STRATUS DECK). I KEPT FOG COVERAGE/TIMING
SIMILAR TO EARLY GUIDANCE COVER POSSIBILITY...HOWEVER CONFIDENCE AT
THIS POINT IS SIGNIFICANTLY LOWER ON WHERE OR IF DENSE FOG MAY
DEVELOP OVER OUR CWA. (FOG MAY BE A GOOD BET BUT DENSE FOG MAY BE
PATCHY).
WEDNESDAY...TWO SHORTWAVES ARE EXPECTED TO MOVE ACROSS THE ROCKIES
AND OVER OUR CWA WITH THE FIRST (WEAKER) SHORTWAVE MOVING OVER OUR
CWA MIDDAY WEDNESDAY. AS WAS INDICATED IN EARLIER GUIDANCE ON MID
SHIFT THERE IS A SIGNIFICANT DRY LAYER FROM ABOVE THE BL TO 600-
700MB. DESPITE FORCING THIS LOWERS CONFIDENCE IN ANY MEASURABLE
PRECIP DURING THE DAY WEDNESDAY. BY LATE WEDNESDAY AFTERNOON THE
SECOND (STRONGER) SHORTWAVE TROUGH DIGS SOUTHEAST AND OVERTAKES THE
FIRST TROUGH WITH A STRONGER UPPER LEVEL JET BEGINNING TO DEVELOP.
BY LATE AFTERNOON THERE IS A WEAK PRECIP SIGNAL IN OUR FAR EASTERN
CWA AND GUIDANCE THERE DOES SHOW SOME MOISTENING OF THE MOISTURE
PROFILE. I KEPT SMALL AREA OF SLIGHT CHANCE POPS IN GRAHAM/NORTON
COUNTIES TO MATCH THIS...BUT CONFIDENCE IS STILL NOT HIGH THAT
THINGS WOULD START THIS EARLY.
OTHER CONCERN FOR WEDNESDAY WILL BE HIGHS. POTENTIAL EXISTS AGAIN
FOR LINGERING STRATUS...HOWEVER WITH TROUGHS MOVING THROUGH THE
REGION THICK/OPAQUE MID-HIGH CLOUD COVER COULD ALSO LIMIT DIURNAL
HEATING. I LOWERED HIGHS IN THE EAST FROM PREVIOUS FORECAST DUE TO
POTENTIAL IMPACTS OF CLOUD COVER. TOUGH CALL AND IF WE WERE TO
CLEAR OUT (MORE LIKELY IN THE WEST) WE COULD SEE HIGHS IN THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 232 AM MST TUE JAN 19 2016
WEDNESDAY AN UPPER LEVEL SHORT WAVE TROUGH WILL MOVE ACROSS THE TRI-
STATE AREA. THE ENVIRONMENT WILL SATURATE ABOVE 700MB AND THERE
WILL BE WEAK LIFT OVER THE AREA. AM THINKING THIS WILL NOT BE
ENOUGH TO GENERATE PRECIPITATION SO WILL LEAVE THE DAY DRY. HIGHS
WILL BE WARMER THAN YESTERDAY BEFORE THE NEXT COLD FRONT MOVES
THROUGH.
WEDNESDAY NIGHT A SECOND STRONGER SHORT WAVE TROUGH MOVES OVER THE
AREA AND DEEPEN INTO A CLOSED LOW. DESPITE THE LOW CLOSING OFF THE
LIFT WITH IT WILL BE VERY WEAK. THE ENVIRONMENT SATURATES DEEPER
THAN DURING THE DAY BEHIND A COLD FRONT. AM THINKING THE BEST
CHANCE FOR SNOW WILL BE OVER THE NORTHEAST HALF OF THE AREA UNDER
THE CLOSED LOW.
THURSDAY MORNING THERE WILL BE SOME LINGERING LIFT OVER THE
NORTHEAST PART OF THE AREA AS THE CLOSED LOW MOVES EASTWARD.
BEHIND THE CLOSED LOW AN UPPER LEVEL RIDGE WILL BUILD OVER THE AREA.
SNOWFALL TOTALS FROM WEDNESDAY NIGHT THROUGH THURSDAY MORNING WILL
BE AROUND AN INCH OR LESS...WITH THE HIGHER AMOUNTS OVER NORTON AND
GRAHAM COUNTIES. BY THE AFTERNOON WINDS WILL STRENGTHEN AS A STRONG
LOW LEVEL JET MOVES OVERHEAD. GUSTS UP TO 40 ARE LIKELY...WITH THE
STRONGEST WINDS WEST OF HIGHWAY 25.
FRIDAY...A HIGH AMPLITUDE RIDGE AXIS WILL SLOWLY MOVE TOWARD THE
AREA DURING THE DAY IN BETWEEN A DEEP LOW PRESSURE SYSTEM OVER THE
MID ATLANTIC AND APPROACHING UPPER TROUGH ALONG THE WEST COAST. FOR
THE OVERNIGHT HOURS THE RIDGE AXIS MOVES OVER THE AREA. AS HAS BEEN
THE CASE THIS PAST WEEKEND THERE WILL BE TALE OF TWO COMPETING
AIR MASSES. COOLER (AND SLIGHTLY BELOW NORMAL) AIR RESIDES ACROSS
THE FAR EASTERN PORTION OF THE AREA WHERE SOUTHEAST WINDS AROUND A
SFC HIGH RESIDE. TO THE WEST A BIT MILDER TEMPERATURES EXIST WHERE
WINDS ARE FROM THE SOUTHWEST. NO CHANGES TO FORECAST TEMPERATURES
WITH MID 30S TO LOW 40S EAST...UPPER 40S TO AROUND 50 WEST. LOW
TEMPERATURES IN THE LOW TO MID 20S.
WILL HAVE TO WATCH FOR THE POSSIBILITY OF STRATUS AND FREEZING FOG
IN THE MORNING EAST OF THE CO/KS BORDER WHERE BOUNDARY LAYER RH OVER
90%. OTHERWISE SUNNY/MOSTLY SUNNY DURING THE DAY WITH ONLY SOME MID
AND/OR HIGH CLOUDS MOVING IN FROM THE WEST. HIGH CLOUDS MOVE OVER
THE AREA DURING THE NIGHT. NO PRECIPITATION EXPECTED.
SATURDAY...FLOW ALOFT BECOMES ZONAL AS A WEAK TROUGH DEVELOPS ACROSS
THE WEST DURING THE DAY...QUICKLY APPROACHING DURING THE NIGHT. SOME
MID AND HIGH CLOUDS DURING THE DAY...DECREASING DURING THE NIGHT. NO
PRECIPITATION EXPECTED. 850MB TEMPERATURES WARM WHICH IS REFLECTED
IN GUIDANCE AND WILL GO WITH MID 40S TO AROUND 50 EAST...MID TO
POSSIBLY UPPER 50S WEST. LOW TEMPERATURES MILD WITH MID TO UPPER 20S.
SUNDAY...CURRENTLY LOOKING LIKE AFTERNOON TEMPERATURES WILL PEAK
AROUND NOON BEFORE NORTH/NORTHWEST WINDS INCREASE A BIT AS COLD
FRONT MOVES THROUGH. CURRENTLY HAVE HIGHS IN THE LOW 40S TO AROUND
50 (NORTH TO SOUTH) WHICH COULD CHANGE GIVEN FRONTS ARRIVAL.
OTHERWISE LOOKING AT AN INCREASE IN CLOUDS AS SOME UPPER TROUGHING
MOVES OVER THE AREA. CURRENTLY HAVE A SLIGHT CHANCE OF PRECIP ACROSS
THE NORTHEAST CORNER OF THE AREA WHICH IS SOMEWHAT QUESTIONABLE AS
MODELS HAVE DIFFERING SOLUTIONS ON THE SPECIFICS. FOR THE OVERNIGHT
HOURS CURRENTLY HAVE SLIGHTLY ABOVE NORMAL MINS IN THE UPPER TEENS
TO MID 20S UNDER A MOSTLY CLOUDY SKY. WILL HAVE TO ADD A SLIGHT
CHANCE OF LIGHT SNOW TO THE FORECAST WITH THE UPPER TROUGH IN THE
AREA AND FAVORABLE MOISTURE.
MONDAY...CLOUDS LINGER DURING THE DAY WITH A DECREASE DURING THE
NIGHT AS HIGH AMPLITUDE RIDGE AXIS MOVES TOWARD THE INTERMOUNTAIN
WEST. AFTERNOON TEMPERATURES CLOSER TO NORMAL WITH UPPER 30S TO LOW
40S. LOW TEMPERATURES IN THE MID TEENS TO LOW 20S. NO PRECIPITATION
EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1023 AM MST TUE JAN 19 2016
LIGHT SNOW/FLURRIES HAVE TRANSITIONED SOUTHEAST OF BOTH KGLD AND
KMCK TERMINALS WITH IFR CIGS AT KGLD AND MVFR CIGS AT KMCK
LINGERING IN THE EARLY PART OF THE TAF PERIOD. SATELLITE AND
UPSTREAM OBS IN NEBRASKA/COLORADO SUPPORT THIS STRATUS LIFTING
BY THE MIDDLE OF THE AFTERNOON IN LINE WITH SHORT RANGE GUIDANCE.
LEE TROUGH REDEVELOPS THIS EVENING WITH SOUTHERLY RETURN FLOW
BRINGING LOW LEVEL MOISTURE BACK OVER BOTH TERMINALS. THERE IS A
STRONG STRATUS/FOG SIGNAL ON SHORT RANGE GUIDANCE AND ENSEMBLES
AND IT APPEARS LIKELY THAT IFR CIGS/VIS WILL DEVELOP AT KGLD THEN
KMCK LATER. I AM CONCERNED THAT THERE COULD BE A PROLONGED DENSE
FOG EVENT (1/4SM) AT KGLD OR KMCK TONIGHT THROUGH WEDNESDAY
MORNING. CONSENSUS STILL FAVORS PREVAILING VIS AROUND 1SM AT THE
PEAK OF THIS FOG EVENT...SO I WILL HOLD OFF ON LOWER VIS FOR NOW
AS IT MAY END UP BEING MORE OF A TEMPORARY CONDITION IF MODELS
ARE OVERDONE ON COVERAGE AS THEY HAVE BEEN THE LAST FEW DAYS.
CONDITIONS SHOULD CLEAR AS A SERIES OF LARGE SCALE DISTURBANCES
MOVE INTO THE REGION WEDNESDAY MORNING INCREASING LOW LEVEL
MIXING. STRATUS/FOG MAY LINGER LONGER AT KMCK...BUT THE TREND
SHOULD BE TOWARDS IMPROVEMENT MID MORNING WEDNESDAY. THERE IS ALSO
THE POSSIBILITY FOR A FEW SNOW SHOWERS OR FLURRIES BEFORE
18Z...HOWEVER CONFIDENCE IS TOO LOW TO ADD DURING THIS UPDATE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...99/JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS WICHITA KS
1138 AM CST TUE JAN 19 2016
...UPDATED FOR 18Z AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 1028 AM CST TUE JAN 19 2016
MAY NEED TO CONSIDER EXPANDING THE WINTER WEATHER ADVISORY
FURTHER WEST TO GENERALLY I-135 THIS AFTERNOON/EVENING...INCLUDING
THE WICHITA METRO. LATEST RAP AND OTHER SHORT-TERM GUIDANCE
SUGGESTS POTENTIAL FOR FREEZING DRIZZLE AS FAR WEST AS HUTCHINSON-
SALINA...DEVELOPING LATE THIS MORNING BUT ESPECIALLY THIS
AFTERNOON-EVENING. GREATEST POTENTIAL STILL LOOKS TO BE GENERALLY
FLINT HILLS ON EAST. ANTICIPATING SNOW ACCUMULATIONS TO BE
MINIMAL...GENERALLY ONE-HALF INCH OR LESS NORTH OF I-70...AND ALSO
OVER SOUTHEAST KANSAS. WILL CONTINUE TO MONITOR TRENDS AND MAKE
TIMELY UPDATES.
ADK
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 359 AM CST TUE JAN 19 2016
A FAST MOVING STORM SYSTEM OVER THE ROCKIES WILL MOVE QUICKLY
EAST ACROSS THE CENTRAL PLAINS STATES TODAY. A PERIOD OF LIGHT
MIXED PRECIPITATION IS ANTICIPATED THROUGH EARLY EVENING BUT
ACCUMULATIONS ARE EXPECTED TO REMAIN LIGHT GIVEN THE PROGRESSIVE
NATURE OF THE MID/UPPER TROUGH AND LACK OF COUPLED FORCING/SCARCE
MOISTURE AVAILABILITY. TEMPERATURES MAY EVEN RISE ABOVE FREEZING
ACROSS FAR SOUTHERN KANSAS RESULTING IN DRIZZLE OR LIGHT RAIN
DURING THE AFTERNOON HOURS. FINALLY...PRECIPITATION IS EXPECTED TO
CHANGE TO PREDOMINATELY SNOW OVER SOUTHEAST KS BY LATE
AFTERNOON/EARLY EVENING WHERE UP TO AN INCH WILL BE POSSIBLE
BEFORE THE ACTIVITY MOVES EAST BY 03-05Z. THE CURRENT WINTER
WEATHER ADVISORY APPEARS TO CAPTURE THE AREA WELL WITH NO CHANGES
PLANNED AT THIS TIME.
WED-THU...SHORTWAVE RIDGING WILL BUILD ACROSS THE CENTRAL PLAINS
STATES ON WED AHEAD OF ANOTHER SHORTWAVE TROUGH MOVING INTO THE
ROCKIES LATE IN THE DAY. LOW LEVEL SOUTHERLY FLOW WILL HELP BOOST
TEMPERATURES INTO THE MID AND UPPER 30S. LARGE-SCALE FORCING FOR
ASCENT WILL INCREASE LATE IN THE DAY WITH SCT RAIN/SNOW SHOWERS
POSSIBLE AFTER 21Z. BETTER CHANCES FOR LIGHT SNOW ACCUMULATIONS
WILL ARRIVE WED NIGHT AND CONTINUE INTO THURSDAY AS A MID/UPPER
TROUGH DEEPENS OVER THE CENTRAL PLAINS STATES. A GENERAL 1-3
INCHES APPEARS POSSIBLE ACROSS MUCH OF THE AREA BEFORE
PRECIPITATION DIMINISHES FROM WEST TO EAST THURSDAY EVENING.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 359 AM CST TUE JAN 19 2016
A MID/UPPER RIDGE WILL ARRIVE TOWARD THE END OF THE WEEK AND
BEGINNING OF THE WEEKEND BRINGING RISING HEIGHTS/INCREASING
THICKNESS AND RISING TEMPERATURES TO THE CENTRAL PLAINS STATES.
HIGHS MAY REACH 50 ACROSS THE AREA ON SAT/SUN BEFORE ANOTHER
PROGRESSIVE SHORTWAVE TROUGH ARRIVES TOWARD THE END OF THE PERIOD
SENDING A SURGE OF CANADIAN AIR SOUTH ACROSS THE AREA AS WE MOVE
INTO THE NEW WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1138 AM CST TUE JAN 19 2016
ANTICIPATING PATCHY TO AREAS OF FREEZING DRIZZLE TO DEVELOP EARLY
THIS AFTERNOON AND PERSIST THROUGH LATE AFTERNOON AND EVENING
GENERALLY ALONG/EAST OF I-135. ALREADY STARTING TO SEE SIGNS OF
THIS IN THE OBSERVATIONAL DATA...AS WELL AS A HANDFUL OF GROUND
TRUTH REPORTS. TERMINALS IMPACTED WILL BE WICHITA AND
CHANUTE...AND POSSIBLY HUTCHINSON AND SALINA AS WELL. COULD SEE A
THIN GLAZE OF ICE ACCUMULATION. FURTHER NORTHWEST...A NARROW BAND
OF LIGHT SNOW MAY AFFECT RUSSELL...GREAT BEND AND SALINA THIS
AFTERNOON...AHEAD OF THE MAIN UPPER SYSTEM PUSHING THROUGH. SNOW
ACCUMULATIONS WILL BE MINIMAL. MVFR TO IFR CIGS WILL PREVAIL
THROUGH AT LEAST THE EVENING...POSSIBLY LONGER.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 32 18 37 28 / 40 20 10 60
HUTCHINSON 30 17 36 27 / 30 10 20 60
NEWTON 30 17 36 28 / 40 20 10 60
ELDORADO 31 19 36 30 / 50 20 10 60
WINFIELD-KWLD 34 20 38 29 / 40 20 10 50
RUSSELL 31 18 40 28 / 20 10 20 50
GREAT BEND 31 18 39 28 / 20 10 20 50
SALINA 29 19 38 27 / 30 10 10 50
MCPHERSON 30 18 36 27 / 30 10 20 60
COFFEYVILLE 35 22 38 31 / 60 40 10 30
CHANUTE 32 20 36 29 / 70 50 10 40
IOLA 31 19 35 29 / 70 60 10 30
PARSONS-KPPF 34 21 36 30 / 70 40 10 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR KSZ071-
072-096.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1031 AM CST TUE JAN 19 2016
.UPDATE...
ISSUED AT 1028 AM CST TUE JAN 19 2016
MAY NEED TO CONSIDER EXPANDING THE WINTER WEATHER ADVISORY FURTHER
WEST TO GENERALLY I-135 THIS AFTERNOON/EVENING...INCLUDING THE
WICHITA METRO. LATEST RAP AND OTHER SHORT-TERM GUIDANCE SUGGESTS
POTENTIAL FOR FREEZING DRIZZLE AS FAR WEST AS HUTCHINSON-
SALINA...DEVELOPING LATE THIS MORNING BUT ESPECIALLY THIS
AFTERNOON-EVENING. GREATEST POTENTIAL STILL LOOKS TO BE GENERALLY
FLINT HILLS ON EAST. ANTICIPATING SNOW ACCUMULATIONS TO BE
MINIMAL...GENERALLY ONE-HALF INCH OR LESS NORTH OF I-70...AND
ALSO OVER SOUTHEAST KANSAS. WILL CONTINUE TO MONITOR TRENDS AND
MAKE TIMELY UPDATES.
ADK
&&
UPDATE ISSUED AT 606 AM CST TUE JAN 19 2016
UPDATED TO PUSH BACK THE ONSET OF ANY WINTRY PRECIP.
LOW LEVEL DRY ADVECTION WILL CONTINUE THIS MORNING WHICH WILL KEEP
THE LOW LAYERS TOO DRY FOR ANY FREEZING DRIZZLE...AT LEAST FOR
MOST OF THE MORNING. SOME LIGHT SNOW AND OR PATCHY FREEZING
DRIZZLE STILL LOOKS POSSIBLE THIS AFTERNOON.
LAWSON
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 359 AM CST TUE JAN 19 2016
A FAST MOVING STORM SYSTEM OVER THE ROCKIES WILL MOVE QUICKLY EAST
ACROSS THE CENTRAL PLAINS STATES TODAY. A PERIOD OF LIGHT MIXED
PRECIPITATION IS ANTICIPATED THROUGH EARLY EVENING BUT ACCUMULATIONS
ARE EXPECTED TO REMAIN LIGHT GIVEN THE PROGRESSIVE NATURE OF THE
MID/UPPER TROUGH AND LACK OF COUPLED FORCING/SCARCE MOISTURE
AVAILABILITY. TEMPERATURES MAY EVEN RISE ABOVE FREEZING ACROSS FAR
SOUTHERN KANSAS RESULTING IN DRIZZLE OR LIGHT RAIN DURING THE
AFTERNOON HOURS. FINALLY...PRECIPITATION IS EXPECTED TO CHANGE TO
PREDOMINATELY SNOW OVER SOUTHEAST KS BY LATE AFTERNOON/EARLY EVENING
WHERE UP TO AN INCH WILL BE POSSIBLE BEFORE THE ACTIVITY MOVES EAST
BY 03-05Z. THE CURRENT WINTER WEATHER ADVISORY APPEARS TO CAPTURE THE
AREA WELL WITH NO CHANGES PLANNED AT THIS TIME.
WED-THU...SHORTWAVE RIDGING WILL BUILD ACROSS THE CENTRAL PLAINS
STATES ON WED AHEAD OF ANOTHER SHORTWAVE TROUGH MOVING INTO THE
ROCKIES LATE IN THE DAY. LOW LEVEL SOUTHERLY FLOW WILL HELP BOOST
TEMPERATURES INTO THE MID AND UPPER 30S. LARGE-SCALE FORCING FOR
ASCENT WILL INCREASE LATE IN THE DAY WITH SCT RAIN/SNOW SHOWERS
POSSIBLE AFTER 21Z. BETTER CHANCES FOR LIGHT SNOW ACCUMULATIONS WILL
ARRIVE WED NIGHT AND CONTINUE INTO THURSDAY AS A MID/UPPER TROUGH
DEEPENS OVER THE CENTRAL PLAINS STATES. A GENERAL 1-3 INCHES APPEARS
POSSIBLE ACROSS MUCH OF THE AREA BEFORE PRECIPITATION DIMINISHES
FROM WEST TO EAST THURSDAY EVENING.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 359 AM CST TUE JAN 19 2016
A MID/UPPER RIDGE WILL ARRIVE TOWARD THE END OF THE WEEK
AND BEGINNING OF THE WEEKEND BRINGING RISING HEIGHTS/INCREASING
THICKNESS AND RISING TEMPERATURES TO THE CENTRAL PLAINS STATES.
HIGHS MAY REACH 50 ACROSS THE AREA ON SAT/SUN BEFORE ANOTHER
PROGRESSIVE SHORTWAVE TROUGH ARRIVES TOWARD THE END OF THE PERIOD
SENDING A SURGE OF CANADIAN AIR SOUTH ACROSS THE AREA AS WE MOVE
INTO THE NEW WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 542 AM CST TUE JAN 19 2016
AVIATION CONCERNS WILL BE LOWER CIGS TODAY ALONG WITH A CHANCE FOR
SOME WINTRY PRECIP.
WATER VAPOR IMAGERY SHOWS SHORTWAVE ENERGY READY TO MOVE OUT
ACROSS THE SOUTHERN HIGH PLAINS. ISENTROPIC LIFT/WARM ADVECTION
OUT AHEAD OF THIS WAVE HAS RESULTED IN LIGHT SNOW OVER CENTRAL
NEBRASKA. LOW CLOUDS CURRENTLY STRETCH NEAR AND ESPECIALLY NORTH
OF I-70 AND SHOULD STAY IN THIS LOCATION FOR THE NEXT COUPLE OF
HOURS. AFTER THIS TIME THEY SHOULD START TO PUSH SOUTH
ENCOMPASSING MOST TAF SITES. AT THIS POINT WILL JUST RUN WITH
MVFR LEVELS WITH IFR THIS AFTERNOON AT KCNU.
EAST WINDS ACROSS THE ENTIRE AREA HAS BEEN PROVIDING LOW LEVEL DRY
ADVECTION WHICH HAS LIMITED ANY LOW LEVEL SATURATION AND
ASSOCIATED FREEZING DRIZZLE. THEREFORE HAVE DELAYED THE START OF
ANY WINTRY PRECIP BY A FEW HOURS AND DON`T THINK WE`LL SEE MUCH
BEFORE 16Z. FEEL THE LOW LEVEL DRY ADVECTION WILL LIMIT ANY
SIGNIFICANT ICE OR SNOW WITH SE KS HAVING THE BEST CHANCE TO SEE
MEASURABLE SNOW THIS AFTERNOON.
LAWSON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 32 18 37 28 / 40 20 10 60
HUTCHINSON 30 17 36 27 / 30 10 20 60
NEWTON 30 17 36 28 / 40 20 10 60
ELDORADO 31 19 36 30 / 50 20 10 60
WINFIELD-KWLD 34 20 38 29 / 40 20 10 50
RUSSELL 31 18 40 28 / 20 10 20 50
GREAT BEND 31 18 39 28 / 20 10 20 50
SALINA 29 19 38 27 / 30 10 10 50
MCPHERSON 30 18 36 27 / 30 10 20 60
COFFEYVILLE 35 22 38 31 / 60 40 10 30
CHANUTE 32 20 36 29 / 70 50 10 40
IOLA 31 19 35 29 / 70 60 10 30
PARSONS-KPPF 34 21 36 30 / 70 40 10 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR KSZ071-
072-096.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
558 PM EST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 354 PM EST TUE JAN 19 2016
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SHRTWV RDG
STRETCHING FM NW ONTARIO IN MN WITHIN NW FLOW ALF ON WRN FLANK OF
DEPARTING UPR LO OVER SE CANADA. ASSOCIATED SFC HI PRES RDG
STRETCHES FM NW ONTARIO THRU THE UPR MS RIVER VALLEY AND TOWARD THE
OH RIVER VALLEY. NW FLOW OF COLD AIR...WITH H925 TEMPS ARND -15C
OVER THE UPR LKS...IN ADVANCE OF THIS SLOWLY APRCHG RDG IS STILL
CAUSING SOME LES...BUT BANDS ARE WEAKER/MORE DISORGANIZED WITH
STRONG SUBSIDENCE ASSOCIATED WITH THE APRCHG RDG LOWERING INVRN BASE
TOWARD 3-4K FT AGL PER MQT VWP. LLVL WINDS ARE BEGINNING TO BACK AS
WELL AHEAD OF THE APRCHG SFC RDG...SO BANDS ARE SHIFTING/LIMITING
RESIDENCE TIME. PLENTY OF LO CLDS LINGER UNDER THE LOWERING INVRN
DESPITE DRY NATURE OF THE NEAR SFC LYR UPSTREAM /WHERE SFC DEWPTS
ARE AOB -20F OVER MUCH OF NRN MN...BUT SOME BREAKS ARE BEGINNING TO
SHOW UP OVER THE FAR W NEAR IWD CLOSER TO THE INCOMING SFC HI PRES/
DRY LLVL AIR AND OVER THE SCENTRL WHERE NW FLOW IS DOWNSLOPING.
THERE IS ANOTHER SHRTWV STRETCHING FM SASKATCHEWAN INTO THE NRN
PLAINS THAT IS DIGGING SEWD...AND SOME HI/MID CLDS AHEAD OF THIS
DISTURBANCE ARE SPREADING INTO MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON LINGERING LES TRENDS/
LO CLDS AND IMPACT ON TEMPS.
TNGT...SFC HI PRES RDG AXIS IS FCST TO SHIFT SLOWLY TO THE E AND
STRETCH FM THE UPR OH VALLEY INTO UPR MI AT 12Z WED. AS THE LLVL
WINDS CONTINUE TO BACK TOWARD THE WSW...ANY LINGERING SN SHOWERS
OVER THE NRN KEWEENAW AND NEAR LK SUP E OF GRAND MARAIS SHOULD LIFT
OUT INTO LK SUP. SINCE THE WINDS WL SHIFT OFFSHORE AND THE INVRN
BASE WL LOWER WITH MORE ACYC LLVL FLOW...EXPECT THE BULK OF THE LO
CLDS TO SHIFT OVER THE LK AS WELL. ALTHOUGH THE SETUP SEEMS
FAVORABLE FOR VERY LO TEMPS WITH LGT OFFSHORE WINDS...MID/HI CLDS ON
THE NRN FRINGES OF SHRTWV DIGGING TO THE SE ARE FCST TO MOVE OVER
THE CWA AND LIMIT THE DIURNAL TEMP FALL. SO ALTHOUGH THERE MAY BE
SOME SUB ZERO MIN TEMPS OVER THE INTERIOR...WIDESPREAD MIN TEMPS
UNDER -10F AS OBSVD THIS MRNG OVER NRN MN ARE NOT LIKELY.
WED...LARGE SCALE QVECTOR DVGC AHEAD OF SHRTWV RDG AND UNDER SFC RDG
AXIS WL MAINTAIN MAINLY DRY WX FOR MOST OF THE CWA...WITH ANY SN
SHOWERS OVER LK SUP NEAR LK INDUCED TROF FCST TO LINGER OVER THE N
HALF OF THE LK. DURING THE DAY...MANY OF THE MODELS SHOW SOME MSTR
RETURN OVER MAINLY THE WRN CWA IN THE SW FLOW BTWN THE SFC RDG
SHIFTING SLOWLY TO THE E AND A SHRTWV APRCHG LATE IN THE DAY FM THE
NW. BUT SINCE ANY FORCING AND LLVL MSTR INFLOW WL BE MINIMAL...OPTED
TO RETAIN ONLY SCHC POPS OVER THE WRN CWA WHERE THE MOISTENING IS
FCST TO BE A BIT MORE ROBUST. EXPECT A SOMEWHAT WARMER AFTN WITH H85
TEMPS REBOUNDING TO ARND -12C BY 00Z THU.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 446 PM EST TUE JAN 19 2016
BY 00Z THURSDAY THE SFC HIGH WILL HAVE SLIPPED TO IL-OH...WITH A
WEAK RIDGE/LAKE INDUCED LOW SLOWLY DEEPENING ACROSS LAKE SUPERIOR AS
THE RIDGE EXITS. THE NEXT IN A SERIES OF SHORTWAVES WILL ASSIST IN
THE LIGHT SNOW SHOWER POTENTIAL WEDNESDAY NIGHT...TRACKING FROM SW
ONTARIO AT 00Z TO FAR N LAKE HURON BY DAYBREAK THURSDAY. THE MAIN
IMPACT WILL BE TO INCREASE NW FLOW ACROSS THE KEWEENAW PENINSULA
BEHIND THE WEAK SFC-500MB TROUGH AND ENHANCING LIGHT SNOW SHOWERS
THERE. 850MB TEMPS WILL BE AROUND -11C. NOT EXPECTING ADVISORY
SNOW AMOUNTS AT THIS TIME.
THE NEXT SFC HIGH SITUATED OVER MANITOBA AND N DAKOTA THURSDAY WILL
PUSH ACROSS MN AND W LAKE SUPERIOR ON FRIDAY...BUT WILL ONLY SLOWLY
BREAK DOWN THE LINGERING WEAK TROUGH OVER E LAKE SUPERIOR/E UPPER MI
BY FRIDAY NIGHT. SFC WINDS WILL SHIFT OUT OF THE N THURSDAY NIGHT
THROUGH FRIDAY AND 850MB TEMPS WILL FALL TO -12 TO -14C...BUT WITH
LIMITED MOISTURE...EXPECT SNOWFALL LESS THAN 2IN.
ANOTHER DRY PERIOD IS EXPECTED FRIDAY NIGHT THROUGH SATURDAY NIGHT
AS ANOTHER AREA OF HIGH PRESSURE SHIFTS ACROSS THE REGION. BY
SATURDAY MORNING ...THE NEXT LOW WILL BET SET UP ACROSS S CENTRAL
CANADA WHILE MUCH OF THE ATTENTION WILL BE ON THE TRACK AND TIMING
OF THE LOW OFF THE MID ATLANTIC COAST. UPPER MI WILL REMAIN IN
BETWEEN SYSTEMS UNTIL THE CANADIAN LOW SHIFTS ACROSS ONTARIO SUNDAY
AND THE EASTERN LOW MOVES OFF THE NEW ENGLAND STATES. THE TROUGH
LOOKS TO CROSS UPPER MI LATE SUNDAY NIGHT/MONDAY MORNING. THE GFS
AND ECMWF ARE OVER 12HRS ON TIMING WHEN THE NEXT SWATH OF SNOW WILL
CROSS UPPER MI SUNDAY AFTERNOON-MONDAY...WITH DIFFERENCES IN THE
TIMING OF THE NEXT LONGWAVE TROUGH MOVING ACROSS THE CENTRAL PLAINS
AND GREAT LAKES STATES. MODERATE TO HIGH CONFIDENCE EXISTS IN THE
ONGOING FORECAST FOR UPPER MI UNTIL SUNDAY. OTHERWISE THE CONSENSUS
FOR MONDAY-TUESDAY WOULD BE FOR AT LEAST SOME COOLER WITH 850MB
TEMPS FALLING AGAIN TO -10 TO -12C.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 558 PM EST TUE JAN 19 2016
AS THE LLVL FLOW BACKS TOWARD THE SW THE REMAINDER OF THIS AFTN AND
DRAWS DRIER AIR INTO UPR MI...EXPECT LINGERING LO CLDS/-SHSN/MVFR
CONDITIONS AT SAW TO GIVE WAY TO VFR WX AND WILL STAY VFR THROUGH
THE PERIOD AT IWD. THE LO CLDS/-SHSN AND MVFR/TEMPO IFR CONDITIONS
AT CMX WL LINGER LONGER...BUT EVEN THERE THE FLOW WL BACK ENUF TO
RESULT IN PREDOMINANT VFR CONDITIONS BY MID/LATE EVNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EST TUE JAN 19 2016
WITH A RELATIVELY WEAK PRES GRADIENT EXPECTED OVER THE UPPER LAKES
MOST OF THIS COMING FORECAST PERIOD...WINDS WILL REMAIN UNDER 25 KTS
MOST OF THE TIME. THE BEST CHANCE FOR SW WINDS UP TO 30 KTS WILL BE
ON SAT...WHEN A SHARPER GRADIENT BETWEEN HI PRES STRETCHING FROM NEW
ENGLAND INTO THE MID MS RIVER VALLEY AND A LO PRES TROF APPROACHING
FROM THE NW MAY SUPPORT THE STRONGER WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
449 PM EST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 354 PM EST TUE JAN 19 2016
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SHRTWV RDG
STRETCHING FM NW ONTARIO IN MN WITHIN NW FLOW ALF ON WRN FLANK OF
DEPARTING UPR LO OVER SE CANADA. ASSOCIATED SFC HI PRES RDG
STRETCHES FM NW ONTARIO THRU THE UPR MS RIVER VALLEY AND TOWARD THE
OH RIVER VALLEY. NW FLOW OF COLD AIR...WITH H925 TEMPS ARND -15C
OVER THE UPR LKS...IN ADVANCE OF THIS SLOWLY APRCHG RDG IS STILL
CAUSING SOME LES...BUT BANDS ARE WEAKER/MORE DISORGANIZED WITH
STRONG SUBSIDENCE ASSOCIATED WITH THE APRCHG RDG LOWERING INVRN BASE
TOWARD 3-4K FT AGL PER MQT VWP. LLVL WINDS ARE BEGINNING TO BACK AS
WELL AHEAD OF THE APRCHG SFC RDG...SO BANDS ARE SHIFTING/LIMITING
RESIDENCE TIME. PLENTY OF LO CLDS LINGER UNDER THE LOWERING INVRN
DESPITE DRY NATURE OF THE NEAR SFC LYR UPSTREAM /WHERE SFC DEWPTS
ARE AOB -20F OVER MUCH OF NRN MN...BUT SOME BREAKS ARE BEGINNING TO
SHOW UP OVER THE FAR W NEAR IWD CLOSER TO THE INCOMING SFC HI PRES/
DRY LLVL AIR AND OVER THE SCENTRL WHERE NW FLOW IS DOWNSLOPING.
THERE IS ANOTHER SHRTWV STRETCHING FM SASKATCHEWAN INTO THE NRN
PLAINS THAT IS DIGGING SEWD...AND SOME HI/MID CLDS AHEAD OF THIS
DISTURBANCE ARE SPREADING INTO MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON LINGERING LES TRENDS/
LO CLDS AND IMPACT ON TEMPS.
TNGT...SFC HI PRES RDG AXIS IS FCST TO SHIFT SLOWLY TO THE E AND
STRETCH FM THE UPR OH VALLEY INTO UPR MI AT 12Z WED. AS THE LLVL
WINDS CONTINUE TO BACK TOWARD THE WSW...ANY LINGERING SN SHOWERS
OVER THE NRN KEWEENAW AND NEAR LK SUP E OF GRAND MARAIS SHOULD LIFT
OUT INTO LK SUP. SINCE THE WINDS WL SHIFT OFFSHORE AND THE INVRN
BASE WL LOWER WITH MORE ACYC LLVL FLOW...EXPECT THE BULK OF THE LO
CLDS TO SHIFT OVER THE LK AS WELL. ALTHOUGH THE SETUP SEEMS
FAVORABLE FOR VERY LO TEMPS WITH LGT OFFSHORE WINDS...MID/HI CLDS ON
THE NRN FRINGES OF SHRTWV DIGGING TO THE SE ARE FCST TO MOVE OVER
THE CWA AND LIMIT THE DIURNAL TEMP FALL. SO ALTHOUGH THERE MAY BE
SOME SUB ZERO MIN TEMPS OVER THE INTERIOR...WIDESPREAD MIN TEMPS
UNDER -10F AS OBSVD THIS MRNG OVER NRN MN ARE NOT LIKELY.
WED...LARGE SCALE QVECTOR DVGC AHEAD OF SHRTWV RDG AND UNDER SFC RDG
AXIS WL MAINTAIN MAINLY DRY WX FOR MOST OF THE CWA...WITH ANY SN
SHOWERS OVER LK SUP NEAR LK INDUCED TROF FCST TO LINGER OVER THE N
HALF OF THE LK. DURING THE DAY...MANY OF THE MODELS SHOW SOME MSTR
RETURN OVER MAINLY THE WRN CWA IN THE SW FLOW BTWN THE SFC RDG
SHIFTING SLOWLY TO THE E AND A SHRTWV APRCHG LATE IN THE DAY FM THE
NW. BUT SINCE ANY FORCING AND LLVL MSTR INFLOW WL BE MINIMAL...OPTED
TO RETAIN ONLY SCHC POPS OVER THE WRN CWA WHERE THE MOISTENING IS
FCST TO BE A BIT MORE ROBUST. EXPECT A SOMEWHAT WARMER AFTN WITH H85
TEMPS REBOUNDING TO ARND -12C BY 00Z THU.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 446 PM EST TUE JAN 19 2016
BY 00Z THURSDAY THE SFC HIGH WILL HAVE SLIPPED TO IL-OH...WITH A
WEAK RIDGE/LAKE INDUCED LOW SLOWLY DEEPENING ACROSS LAKE SUPERIOR AS
THE RIDGE EXITS. THE NEXT IN A SERIES OF SHORTWAVES WILL ASSIST IN
THE LIGHT SNOW SHOWER POTENTIAL WEDNESDAY NIGHT...TRACKING FROM SW
ONTARIO AT 00Z TO FAR N LAKE HURON BY DAYBREAK THURSDAY. THE MAIN
IMPACT WILL BE TO INCREASE NW FLOW ACROSS THE KEWEENAW PENINSULA
BEHIND THE WEAK SFC-500MB TROUGH AND ENHANCING LIGHT SNOW SHOWERS
THERE. 850MB TEMPS WILL BE AROUND -11C. NOT EXPECTING ADVISORY
SNOW AMOUNTS AT THIS TIME.
THE NEXT SFC HIGH SITUATED OVER MANITOBA AND N DAKOTA THURSDAY WILL
PUSH ACROSS MN AND W LAKE SUPERIOR ON FRIDAY...BUT WILL ONLY SLOWLY
BREAK DOWN THE LINGERING WEAK TROUGH OVER E LAKE SUPERIOR/E UPPER MI
BY FRIDAY NIGHT. SFC WINDS WILL SHIFT OUT OF THE N THURSDAY NIGHT
THROUGH FRIDAY AND 850MB TEMPS WILL FALL TO -12 TO -14C...BUT WITH
LIMITED MOISTURE...EXPECT SNOWFALL LESS THAN 2IN.
ANOTHER DRY PERIOD IS EXPECTED FRIDAY NIGHT THROUGH SATURDAY NIGHT
AS ANOTHER AREA OF HIGH PRESSURE SHIFTS ACROSS THE REGION. BY
SATURDAY MORNING ...THE NEXT LOW WILL BET SET UP ACROSS S CENTRAL
CANADA WHILE MUCH OF THE ATTENTION WILL BE ON THE TRACK AND TIMING
OF THE LOW OFF THE MID ATLANTIC COAST. UPPER MI WILL REMAIN IN
BETWEEN SYSTEMS UNTIL THE CANADIAN LOW SHIFTS ACROSS ONTARIO SUNDAY
AND THE EASTERN LOW MOVES OFF THE NEW ENGLAND STATES. THE TROUGH
LOOKS TO CROSS UPPER MI LATE SUNDAY NIGHT/MONDAY MORNING. THE GFS
AND ECMWF ARE OVER 12HRS ON TIMING WHEN THE NEXT SWATH OF SNOW WILL
CROSS UPPER MI SUNDAY AFTERNOON-MONDAY...WITH DIFFERENCES IN THE
TIMING OF THE NEXT LONGWAVE TROUGH MOVING ACROSS THE CENTRAL PLAINS
AND GREAT LAKES STATES. MODERATE TO HIGH CONFIDENCE EXISTS IN THE
ONGOING FORECAST FOR UPPER MI UNTIL SUNDAY. OTHERWISE THE CONSENSUS
FOR MONDAY-TUESDAY WOULD BE FOR AT LEAST SOME COOLER WITH 850MB
TEMPS FALLING AGAIN TO -10 TO -12C.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM EST TUE JAN 19 2016
AS THE LLVL FLOW BACKS TOWARD THE SW THE REMAINDER OF THIS AFTN AND
DRAWS DRIER AIR INTO UPR MI...EXPECT LINGERING LO CLDS/-SHSN/MVFR
CONDITIONS AT IWD AND SAW TO GIVE WAY TO VFR WX. THE LO CLDS/-SHSN
AND MVFR/TEMPO IFR CONDITIONS AT CMX WL LINGER LONGER...BUT EVEN
THERE THE FLOW WL BACK ENUF TO RESULT IN PREDOMINANT VFR CONDITIONS
BY MID/LATE EVNG. SOME MVFR CLDS MAY RETURN TO IWD LATE IN THE TAF
PERIOD AHEAD OF A WEAK DISTURBANCE...BUT FCST CONTINUED VFR CIGS IN
THE ABSENCE OF SGNFT MSTR RETURN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EST TUE JAN 19 2016
WITH A RELATIVELY WEAK PRES GRADIENT EXPECTED OVER THE UPPER LAKES
MOST OF THIS COMING FORECAST PERIOD...WINDS WILL REMAIN UNDER 25 KTS
MOST OF THE TIME. THE BEST CHANCE FOR SW WINDS UP TO 30 KTS WILL BE
ON SAT...WHEN A SHARPER GRADIENT BETWEEN HI PRES STRETCHING FROM NEW
ENGLAND INTO THE MID MS RIVER VALLEY AND A LO PRES TROF APPROACHING
FROM THE NW MAY SUPPORT THE STRONGER WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
354 PM EST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 354 PM EST TUE JAN 19 2016
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SHRTWV RDG
STRETCHING FM NW ONTARIO IN MN WITHIN NW FLOW ALF ON WRN FLANK OF
DEPARTING UPR LO OVER SE CANADA. ASSOCIATED SFC HI PRES RDG
STRETCHES FM NW ONTARIO THRU THE UPR MS RIVER VALLEY AND TOWARD THE
OH RIVER VALLEY. NW FLOW OF COLD AIR...WITH H925 TEMPS ARND -15C
OVER THE UPR LKS...IN ADVANCE OF THIS SLOWLY APRCHG RDG IS STILL
CAUSING SOME LES...BUT BANDS ARE WEAKER/MORE DISORGANIZED WITH
STRONG SUBSIDENCE ASSOCIATED WITH THE APRCHG RDG LOWERING INVRN BASE
TOWARD 3-4K FT AGL PER MQT VWP. LLVL WINDS ARE BEGINNING TO BACK AS
WELL AHEAD OF THE APRCHG SFC RDG...SO BANDS ARE SHIFTING/LIMITING
RESIDENCE TIME. PLENTY OF LO CLDS LINGER UNDER THE LOWERING INVRN
DESPITE DRY NATURE OF THE NEAR SFC LYR UPSTREAM /WHERE SFC DEWPTS
ARE AOB -20F OVER MUCH OF NRN MN...BUT SOME BREAKS ARE BEGINNING TO
SHOW UP OVER THE FAR W NEAR IWD CLOSER TO THE INCOMING SFC HI PRES/
DRY LLVL AIR AND OVER THE SCENTRL WHERE NW FLOW IS DOWNSLOPING.
THERE IS ANOTHER SHRTWV STRETCHING FM SASKATCHEWAN INTO THE NRN
PLAINS THAT IS DIGGING SEWD...AND SOME HI/MID CLDS AHEAD OF THIS
DISTURBANCE ARE SPREADING INTO MN.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON LINGERING LES TRENDS/
LO CLDS AND IMPACT ON TEMPS.
TNGT...SFC HI PRES RDG AXIS IS FCST TO SHIFT SLOWLY TO THE E AND
STRETCH FM THE UPR OH VALLEY INTO UPR MI AT 12Z WED. AS THE LLVL
WINDS CONTINUE TO BACK TOWARD THE WSW...ANY LINGERING SN SHOWERS
OVER THE NRN KEWEENAW AND NEAR LK SUP E OF GRAND MARAIS SHOULD LIFT
OUT INTO LK SUP. SINCE THE WINDS WL SHIFT OFFSHORE AND THE INVRN
BASE WL LOWER WITH MORE ACYC LLVL FLOW...EXPECT THE BULK OF THE LO
CLDS TO SHIFT OVER THE LK AS WELL. ALTHOUGH THE SETUP SEEMS
FAVORABLE FOR VERY LO TEMPS WITH LGT OFFSHORE WINDS...MID/HI CLDS ON
THE NRN FRINGES OF SHRTWV DIGGING TO THE SE ARE FCST TO MOVE OVER
THE CWA AND LIMIT THE DIURNAL TEMP FALL. SO ALTHOUGH THERE MAY BE
SOME SUB ZERO MIN TEMPS OVER THE INTERIOR...WIDESPREAD MIN TEMPS
UNDER -10F AS OBSVD THIS MRNG OVER NRN MN ARE NOT LIKELY.
WED...LARGE SCALE QVECTOR DVGC AHEAD OF SHRTWV RDG AND UNDER SFC RDG
AXIS WL MAINTAIN MAINLY DRY WX FOR MOST OF THE CWA...WITH ANY SN
SHOWERS OVER LK SUP NEAR LK INDUCED TROF FCST TO LINGER OVER THE N
HALF OF THE LK. DURING THE DAY...MANY OF THE MODELS SHOW SOME MSTR
RETURN OVER MAINLY THE WRN CWA IN THE SW FLOW BTWN THE SFC RDG
SHIFTING SLOWLY TO THE E AND A SHRTWV APRCHG LATE IN THE DAY FM THE
NW. BUT SINCE ANY FORCING AND LLVL MSTR INFLOW WL BE MINIMAL...OPTED
TO RETAIN ONLY SCHC POPS OVER THE WRN CWA WHERE THE MOISTENING IS
FCST TO BE A BIT MORE ROBUST. EXPECT A SOMEWHAT WARMER AFTN WITH H85
TEMPS REBOUNDING TO ARND -12C BY 00Z THU.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EST TUE JAN 19 2016
...SMALL CHANCES OF SNOW THROUGH THE WEEK WITH A WARMING TREND BY
THE WEEKEND...
UPPER LOW AND CORE OF THE COLD WILL BE OVER FAR EASTERN CANADA
AROUND LABRADOR ON WED WHILE WNW FLOW ALOFT BRINGS WARMER AIR ALOFT
FM WESTERN CANADA TO GREAT LAKES. NW FLOW PERSISTS THROUGH LATE WEEK
BUT SYSTEMS WITHIN THIS FLOW LOOK TO REMAIN WEAK. LATER THU INTO
FRI...A MUCH STRONGER TROUGH ALOFT TAKES SHAPE OVER SOUTHERN PLAINS
AND THOUGH THIS SYSTEM WILL STAY WELL TO SOUTH OF GREAT LAKES...IT
COULD BECOME SIGNIFICANT WINTER STORM FOR THE MID ATLANTIC THIS
WEEKEND. AS THAT IS OCCURRING THERE...RIDGING WILL BE BUILDING FM
THE WESTERN CONUS INTO THE MID CONUS AND WESTERN GREAT LAKES. THERMAL
RIDGE POKES ACROSS UPPER LAKES ON SAT INTO SUN WHEN TEMPS COULD REACH
NEAR 30 DEGREES...THEN TURNS COOLER BY MON IN WAKE OF A COLD FRONT.
OVERALL NOT A LOT OF OPPORTUNTIES FOR MUCH SNOW IN THE EXPECTED
PATTERN...EITHER WIDESPREAD SYSTEM TYPE OR LAKE EFFECT...BUT THERE
WILL BE SOME CHANCES FOR LIGHT SNOW. FIRST ON WED...SHORTWAVE TROUGH
CURRENTLY CROSSING NORTHERN PLAINS WILL BE BRINGING LIGHT SNOW FROM
ILL TO LOWER MI. OVER UPR MICHIGAN...DRY AIR BLO 10KFT WILL PROHIBIT
MUCH SNOWFALL TO START BUT THEN MOISTURE INCREASES THROUGH THE DAY.
LIFT REMAINS WEAK THOUGH SO STILL NOT LOOKING AT EVEN AN INCH OF
SNOW WITH THIS SYSTEM ANYWHERE IN THE CWA. ANOTHER WEAKER SYSTEM
CROSSES NW ONTARIO AND THE UPPER GREAT LAKES WED NIGHT INTO THU.
BEST FORCING STAYS OVER LK SUPERIOR AND INTO NW ONTARIO...BUT WEAK
SFC TROUGH TIED TO THE SHORTWAVE COULD BRING LIGHT SNOW TO KEWEENAW.
AS TROUGH MOVES THROUGH...MAY SEE LIGHT LAKE EFFECT SNOW SHOWERS THU
NIGHT INTO FRI WITH H85 TEMPS DOWN TO AROUND -13C AND MAYBE AS LOW AS
-15C WHILE ANOTHER WEAKER SHORTWAVE CROSSES UPPER GREAT LAKES. LOW-
LEVEL WINDS START OUT NW IN WAKE OF TROUGH BUT BECOME NORTHERLY BY
FRI...SO GOOD PART OF LK SUPERIOR SHORE COULD SEE LAKE EFFECT THU
NIGHT INTO FRI. GFS SOUNDINGS SHOW ALL THE MOIST LAYER WITHIN THE
DGZ...SO FLUFF FACTOR COULD BE HIGHER. BUT...MARGINALLY COLD
TEMPS...INVERSIONS LESS THAN 5KFT AND LACK OF STRONG LOW-LEVEL
CONVERGENCE SHOULD LIMIT INTENSITY OF LAKE EFFECT. INCREASED POPS
OVER CONSENSUS AS THINK THERE SHOULD BE SOME SNOW AROUND FOR THE
FAVORED LAKE EFFECT AREAS.
HIGH PRESSURE RIDGE CROSSING FRI NIGHT INTO SAT SWITCHES WINDS TO SW
AND BRINGS WARMER AIRMASS OVER THE UPPER GREAT LAKES...SO LAKE
EFFECT WILL END. H85 TEMPS AROUND -10C FRI NIGHT WARM TO -6C BY SAT
MORNING AND -2C BY SAT EVENING. SKIES ON SAT SHOULD START OUT MOSTLY
SUNNY THEN THERE WILL BE THICKENING MID-HIGH CLOUDS IN THE AFTN
AHEAD OF ANOTHER SHORTWAVE TROUGH AND WEAK WAVE OF LOW PRES CROSSING
NORTHERN PLAINS INTO NW ONTARIO. SOUNDINGS INDICATE SHALLOW MIXING
HEIGHTS OF 950MB-925MB ON SAT BUT WITH GOOD DEAL OF SUNSHINE...COULD
BE HIGHER. SHALLOW MIXING SUPPORTS HIGHS INTO THE UPPER 20S.
SLIGHTLY DEEPER MIXING TO 900MB WOULD YIELD HIGHS INTO THE MID-UPR
30S. DEEPER MIXING COULD TAP INTO PORTION OF 30-40 KT WINDS ALOFT.
ATTM LOOKS LIKE MAX CORE OF WINDS WILL STAY ABOVE INVERION...BUT
STILL COULD BE BREEZY BY AFTN DUE TO THE TIGHTER PRESSURE GRADIENT
BTWN THE EXITING RIDGE AND SFC LOW/COLD FRONT SCNTRL CANADA TO
NORTHERN PLAINS. NUDGED MAX TEMPS UPWARD OVER CONSENSUS BUT ONLY
INTO THE LOW 30S AT THE WARMEST. AS THAT SYSTEM MOVES INTO NW
ONTARIO MAY SEE LIGHT SNOW OR FLURRIES OVER UPR MICHIGAN. MODELS NOT
VERY CONSISTENT ON THAT IDEA...BUT WORTHY OF LOW CHANCES ESPECIALLY
NORTH CWA AND OUT ACROSS LK SUPERIOR.
MAY SEE ANOTHER ROUND OF LIGHT LAKE EFFECT SNOW SUN NIGHT INTO MON
AND THERE ARE SOME INDICATIONS OF ANOTHER SHORTWAVE MOVING THROUGH
WITH A WAVE OF LIGHT SNOW OVER UPPER GREAT LAKES. PLENTY OF TIME FOR
DETAILS TO CHANGE...BUT AT THIS TIME NOT LOOKING LIKE MUCH SNOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM EST TUE JAN 19 2016
AS THE LLVL FLOW BACKS TOWARD THE SW THE REMAINDER OF THIS AFTN AND
DRAWS DRIER AIR INTO UPR MI...EXPECT LINGERING LO CLDS/-SHSN/MVFR
CONDITIONS AT IWD AND SAW TO GIVE WAY TO VFR WX. THE LO CLDS/-SHSN
AND MVFR/TEMPO IFR CONDITIONS AT CMX WL LINGER LONGER...BUT EVEN
THERE THE FLOW WL BACK ENUF TO RESULT IN PREDOMINANT VFR CONDITIONS
BY MID/LATE EVNG. SOME MVFR CLDS MAY RETURN TO IWD LATE IN THE TAF
PERIOD AHEAD OF A WEAK DISTURBANCE...BUT FCST CONTINUED VFR CIGS IN
THE ABSENCE OF SGNFT MSTR RETURN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EST TUE JAN 19 2016
WITH A RELATIVELY WEAK PRES GRADIENT EXPECTED OVER THE UPPER LAKES
MOST OF THIS COMING FORECAST PERIOD...WINDS WILL REMAIN UNDER 25 KTS
MOST OF THE TIME. THE BEST CHANCE FOR SW WINDS UP TO 30 KTS WILL BE
ON SAT...WHEN A SHARPER GRADIENT BETWEEN HI PRES STRETCHING FROM NEW
ENGLAND INTO THE MID MS RIVER VALLEY AND A LO PRES TROF APPROACHING
FROM THE NW MAY SUPPORT THE STRONGER WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1207 PM CST TUE JAN 19 2016
.UPDATE:
Issued at 1021 AM CST Tue Jan 19 2016
Have got reports of light snow in Mexico and Columbia ahead of
the main band of snow farther west where visibilities have been
reduced to around 1 mile. Still expect this band to move slowly
east today as there will be some sublimation by dry air in the
lower atmosphere. Latest runs of the RAP and HRRR does show a
sharp increase ascent ahead of the mid level trough later this
afternoon and this evening which should increase the coverage of
snow coverage over the area. Low-mid level moisture convergence will
increase ahead of this trough late this afternoon into the evening
along and south of I-70 which will aid in the production of snow
and some sleet.
The precipitation falling into the dry air and the clouds should
keep temperatures from rising too much today. Otherwise...going
forecast looks pretty much on track.
Britt
&&
.SHORT TERM: (Through Tonight)
Issued at 403 AM CST Tue Jan 19 2016
All is on track for the first really widespread accumulating
snowfall of at least a couple of inches across the CWA. Latest NWP
guidance continues the colder trend in the lower levels.
Consequently...confined the mention of sleet to a small portion of
southeastern Missouri. Where sleet does mix in with the snow...it
appears it would likely be fairly brief and not too greatly affect
snow totals down that way. Going with a colder profile...also bumped
snow-to-liquid ratios up a bit higher though did not want to get too
aggressive as strongest ascent should be well below DGZ which may
mix in columns with dendrites. If columns end up being favored over
dendrites for any length of time...forecast snow amounts would
likely be a bit too high However...models have also come in a touch
drier for most locations...particularly the northern 2/3 of the CWA.
Therefore...snow amounts across much of the area are very similar to
what the day shift had forecast with the notable exception of
portions of southeastern Missouri and southwestern Illinois. The
snow totals across these areas were boosted primarily due to the
colder profile.
Light snow is expected to transverse the area very late this morning
and into the afternoon within a band of 850-700 hPa frontogenesis.
Atmosphere is initially quite dry attm...but believe saturation at
mid/lower levels should occur across portions of north-central
Missouri southeastward toward the St. Louis metro area by mid
afternoon.
The main thrust of snowfall still appears to be from 0000 UTC to
09000 UTC tonight as the trough axis approaches from the west
coincident with very strong warm/moist advection on the nose of a 40-
kt LLJ. Models have begun to depict two precipitation maxima with
this event (or one minimum depending on how you look at it). One
precip/snowfall maximum from roughly KMYJ>K3LF due to the
combination of the aforementioned frontogenetically-driven band of
snow during the day today and strong DCPVA ahead of a northern vort
max. Another area of enhanced precipitaton is shown across portions
of southeastern Missouri and southwest Illinois where the strongest
low-level forcing will reside tonight. Conceptually...this seems
very plausible. All that being said...still looks like areas across
central and northeastern Missouri as well as west-central Illinois
are in line to get 3 to 4+ inches of snow. Further southeast...most
of the rest of the area is expected to receive near 3 inches of snow.
Gosselin
.LONG TERM: (Wednesday through Monday)
Issued at 403 AM CST Tue Jan 19 2016
A brief break is expected along with dry conditions on Wednesday.
Lowered high temperatures for most areas a couple of degrees due
to expected snow cover across CWA.
As alluded to by previous forecaster...system on Thursday/Thursday
night appears more interesting than 24 hours ago. Complex system
evolution expected as a lead shortwave comes toward the MO/KS border
late Wednesday night with a southern vort diving toward the Arklatex
region. Two distinct vorticity maxima appear to have a bit of the
Fujiwara effect with the northern vort rotating counter-clockwise
around the more dominant/stronger southern vort. Combination of weak
WAA and support aloft is expected to develop light snow during
the day on Thursday. Best chances south of I-70. Models diverge a
bit on track/strength of system but appears a deformation zone
will form on Thursday night and continue into Friday. Best chances
of snowfall with this feature would likely be across far southern
portions of the CWA. Still a lot of model spread for this
particular system and it bears watching. Taking a look at 16 GFS
ensemble members yielded 4 members much further north than
operational run with a few others quite a bit further south too.
Mostly dry weather is forecast for this weekend and next Monday
along with moderating temperatures back to near normal.
However...depending on exactly how much snow falls and where over
the next several days...these temperatures could be too warm or
too cold.
Gosselin
&&
.AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1207 AM CST Tue Jan 19 2016
A band of snow is getting ready to move into KCOU and will continue
to move east toward KUIN and the St. Louis area terminals later
this afternoon. Snow is expected to continue into this evening and
will accumulate 3-4 inches at all of the terminals before ending
shortly between 06-12Z at the terminals once the system moves
east of the area. The snow will require the clearing of runways
and will reduce the visibilities to IFR at times. Even after the
snow ends, the ceilings may stay IFR for a time before they
improve to low MVFR.
Specifics for KSTL: Snow is expected to move into the terminal
from the west after 18Z. The snow will reduce visibilities to MVFR
or IFR at times as the snow begins to accumulate during the late
afternoon and evening hours. Total accumulations are expected to
be around 3 inches. Even after the snow ends, the ceilings may
stay IFR for a time before they improve to low MVFR. VFR ceilings
are expect after 18Z tomorrow when drier air moves into the area.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Winter Weather Advisory until 6 AM CST Wednesday FOR Audrain MO-
Boone MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-
Gasconade MO-Jefferson MO-Knox MO-Lewis MO-Lincoln MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike
MO-Ralls MO-Shelby MO-St. Charles MO-St. Louis City MO-St.
Louis MO-Warren MO-Washington MO.
Winter Weather Advisory from 6 PM this evening to 6 AM CST
Wednesday FOR Iron MO-Madison MO-Reynolds MO-St. Francois
MO-Ste. Genevieve MO.
IL...Winter Weather Advisory until 6 AM CST Wednesday FOR Adams IL-
Brown IL-Calhoun IL-Greene IL-Jersey IL-Madison IL-Monroe
IL-Pike IL-St. Clair IL.
Winter Weather Advisory from 6 PM this evening to 6 AM CST
Wednesday FOR Bond IL-Clinton IL-Fayette IL-Macoupin IL-
Marion IL-Montgomery IL-Randolph IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1022 AM CST TUE JAN 19 2016
.UPDATE:
Issued at 1021 AM CST Tue Jan 19 2016
Have got reports of light snow in Mexico and Columbia ahead of
the main band of snow farther west where visibilites have been
reduced to around 1 mile. Still expect this band to move slowly
east today as there will be some sublimation by dry air in the
lower atmosphere. Latest runs of the RAP and HRRR does show a
sharp increase ascent ahead of the mid level trough later this
afternoon and this evening which should increase the coverage of
snow coverage over the area. Low-mid level moisture convergence will
increase ahead of this trough late this afternoon into the evening
along and south of I-70 which will aid in the production of snow
and some sleet.
The precipitation falling into the dry air and the clouds should
keep temperatures from rising too much today. Otherwise...going
forecast looks pretty much on track.
Britt
&&
.SHORT TERM: (Through Tonight)
Issued at 403 AM CST Tue Jan 19 2016
All is on track for the first really widespread accumulating
snowfall of at least a couple of inches across the CWA. Latest NWP
guidance continues the colder trend in the lower levels.
Consequently...confined the mention of sleet to a small portion of
southeastern Missouri. Where sleet does mix in with the snow...it
appears it would likely be fairly brief and not too greatly affect
snow totals down that way. Going with a colder profile...also bumped
snow-to-liquid ratios up a bit higher though did not want to get too
aggressive as strongest ascent should be well below DGZ which may
mix in columns with dendrites. If columns end up being favored over
dendrites for any length of time...forecast snow amounts would
likely be a bit too high However...models have also come in a touch
drier for most locations...particularly the northern 2/3 of the CWA.
Therefore...snow amounts across much of the area are very similar to
what the day shift had forecast with the notable exception of
portions of southeastern Missouri and southwestern Illinois. The
snow totals across these areas were boosted primarily due to the
colder profile.
Light snow is expected to transverse the area very late this morning
and into the afternoon within a band of 850-700 hPa frontogenesis.
Atmosphere is initially quite dry attm...but believe saturation at
mid/lower levels should occur across portions of north-central
Missouri southeastward toward the St. Louis metro area by mid
afternoon.
The main thrust of snowfall still appears to be from 0000 UTC to
09000 UTC tonight as the trough axis approaches from the west
coincident with very strong warm/moist advection on the nose of a 40-
kt LLJ. Models have begun to depict two precipitation maxima with
this event (or one minimum depending on how you look at it). One
precip/snowfall maximum from roughly KMYJ>K3LF due to the
combination of the aforementioned frontogenetically-driven band of
snow during the day today and strong DCPVA ahead of a northern vort
max. Another area of enhanced precipitaton is shown across portions
of southeastern Missouri and southwest Illinois where the strongest
low-level forcing will reside tonight. Conceptually...this seems
very plausible. All that being said...still looks like areas across
central and northeastern Missouri as well as west-central Illinois
are in line to get 3 to 4+ inches of snow. Further southeast...most
of the rest of the area is expected to receive near 3 inches of snow.
Gosselin
.LONG TERM: (Wednesday through Monday)
Issued at 403 AM CST Tue Jan 19 2016
A brief break is expected along with dry conditions on Wednesday.
Lowered high temperatures for most areas a couple of degrees due
to expected snow cover across CWA.
As alluded to by previous forecaster...system on Thursday/Thursday
night appears more interesting than 24 hours ago. Complex system
evolution expected as a lead shortwave comes toward the MO/KS border
late Wednesday night with a southern vort diving toward the Arklatex
region. Two distinct vorticity maxima appear to have a bit of the
Fujiwara effect with the northern vort rotating counter-clockwise
around the more dominant/stronger southern vort. Combination of weak
WAA and support aloft is expected to devlop light snow during the
day on Thursday. Best chances south of I-70. Models diverge a bit on
track/strength of system but appears a deformation zone will form on
Thursday night and continue into Friday. Best chances of snowfall
with this feature would likely be across far southern portions of
the CWA. Still a lot of model spread for this particular system and
it bears watching. Taking a look at 16 GFS ensemble members yielded
4 members much futher north than operational run with a few others
quite a bit further south too.
Mostly dry weather is forecast for this weekend and next Monday
along with moderating temperatures back to near normal.
However...depending on exatly how much snow falls and where over the
next several days...these temperatures could be too warm or too cold.
Gosselin
&&
.AVIATION: (For the 12z TAFs through 12z Wednesday Morning)
Issued at 550 AM CST Tue Jan 19 2016
Mid and high clouds moving in ahead of weather system this
morning. Will see snow develop and spread east across the area
after 17z with cigs and vsbys lowering to MVFR with onset, then
dip down to IFR with the heavier bands of snow by this afternoon
through this evening. Snow to taper off from west to east after
05z Wednesday. Otherwise, winds to persist from the east through
the forecast period.
Specifics for KSTL:
Mid and high clouds moving in ahead of weather system this
morning. Will see snow develop and spread into the STL metro area
by 21z with cigs and vsbys lowering to MVFR with onset, then dip
down to IFR with the heavier bands of snow by 00z Wednesday. Snow
to taper off after 07z Wednesday. Otherwise, winds to persist
from the east through the forecast period.
Byrd
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 23 20 29 23 / 70 100 10 5
Quincy 20 16 26 20 / 80 90 10 5
Columbia 23 20 32 23 / 90 90 5 10
Jefferson City 25 21 32 24 / 90 90 5 10
Salem 22 20 27 22 / 20 100 40 5
Farmington 25 22 31 23 / 40 90 20 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Winter Weather Advisory until 6 AM CST Wednesday FOR Audrain MO-
Boone MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-
Gasconade MO-Jefferson MO-Knox MO-Lewis MO-Lincoln MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike
MO-Ralls MO-Shelby MO-St. Charles MO-St. Louis City MO-St.
Louis MO-Warren MO-Washington MO.
Winter Weather Advisory from 6 PM this evening to 6 AM CST
Wednesday FOR Iron MO-Madison MO-Reynolds MO-St. Francois
MO-Ste. Genevieve MO.
IL...Winter Weather Advisory until 6 AM CST Wednesday FOR Adams IL-
Brown IL-Calhoun IL-Greene IL-Jersey IL-Madison IL-Monroe
IL-Pike IL-St. Clair IL.
Winter Weather Advisory from 6 PM this evening to 6 AM CST
Wednesday FOR Bond IL-Clinton IL-Fayette IL-Macoupin IL-
Marion IL-Montgomery IL-Randolph IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
338 PM CST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 336 PM CST TUE JAN 19 2016
MAIN CONCERN IS FOG POTENTIAL TONIGHT. GENERAL SYNOPTIC PATTERN IS
QUITE PROGRESSIVE AS WE TRANSITION TO A HIGHER AMPLITUDE SCENARIO.
TONIGHT...THE CONCERN GOES TO FOG POTENTIAL TONIGHT AS WIND WILL BE
LIGHT FROM THE SOUTH. THE HRRR IS HITTING THE FOG POTENTIAL A LITTLE
HARD CENTRAL AND WEST. THE SREF IS ALSO HITTING FOG A LITTLE HARD
EVERYWHERE ACROSS THE CWA...ESPECIALLY WEST. I WENT WITH STRONG
WORDING IN THE FORECAST TO AREAS RATHER THAN PATCHY AND EXTENDED THE
FOG MENTION FARTHER EAST THAN THE PREVIOUS FORECAST.
WE MAY SEE A LITTLE SUN WEDNESDAY MORNING BEFORE IT CLOUDS BACK UP
IN ADVANCE OF THE NEXT WAVE QUICKLY APPROACHING. WARM AIR ADVECTION
SHOULD BOOST TEMPERATURES A GOOD 10 DEGREES WARMER ON WEDNESDAY
COMPARED TO TODAY. NOT EXPECTING PRECIP UNTIL PERHAPS BETWEEN 21Z
AND 00Z THURSDAY IN OUR FAR SOUTH...WHERE RAIN/SNOW COULD
OCCUR...BUT THE BETTER CHANCES WILL LIKELY BE TOWARD WEDNESDAY
NIGHT...IN THE LONG TERM FORECAST.
SUPERBLEND TEMPERATURES LOOKED REASONABLE...WHICH LOWERED
TEMPERATURES A BIT FOR WEDNESDAY HIGHS COMPARED TO THE PREVIOUS
FORECAST. THIS SEEMS REASONABLE CONSIDERING LINGERING FOG POTENTIAL
AND INCREASING SKY COVER BY AFTERNOON. BCONSRAW AND NAM12 SOLUTIONS
INDICATE THAT IT MIGHT EVEN BE A BIT COOLER THAN THE MID 30S I HAVE
ADVERTISED IN THE FORECAST....WITH COOLER TEMPERATURES EAST AND
WARMER WEST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 336 PM CST TUE JAN 19 2016
ALOFT: VERY LITTLE CHANGE IN THE PATTERN IS ENVISIONED FOR AT LEAST
THE NEXT WEEK. A MEAN TROF WILL REMAIN OVER THE E PAC WITH THE MEAN
RIDGE OVER WRN N AMERICA. THE FLOW WILL INITIALLY BE MODERATELY
AMPLIFIED BUT WILL DEAMPLIFY TEMPORARILY AS A TROF MOWS DOWN THE
RIDGE FRI-SAT AND EMERGES INTO THE PLAINS SUN-MON. NW FLOW WILL
FOLLOW TUE.
AT 00Z/THU A SHORTWAVE TROF WILL BE MOVING IN AND AMPLIFYING...WITH
A MID-LVL CIRCULATION CLOSING OFF OVER NEB/KS BY 06Z. THIS LOW WILL
DROP SSE THU WITH QUIETER WX TO FOLLOW.
SURFACE: A WEAK COLD FRONT WILL MOVE THRU WED NIGHT. LEE
CYCLOGENESIS WILL BE UNDERWAY WED EVE WITH THE SFC LOW FAR TO THE S
OVER TX. CANADIAN HIGH PRES WILL GRADUALLY BUILD IN THU-FRI. RETURN
FLOW DEVELOPS SAT AS A CLIPPER HEADS E ACROSS SRN CANADA. A NICE
DOWNSLOPE-WARMED AIR MASS WILL OVERTAKE THE REGION...BUT SNOW ON THE
GROUND WILL TEMPER THE WARM-UP. THE NEXT PAC COOL FRONT WILL BE
MAKING ITS WAY THRU THE WRN USA AND WILL ARRIVE HERE LATE SUN. HIGH
PRES WILL MOVE IN MON AND DROP INTO THE SRN PLAINS TUE.
SOME DAILY DETAILS...
WED NIGHT: SNOW WILL BE BLOSSOMING OVER N-CNTRL KS AND EXPANDING N
INTO S-CNTRL NEB.
THU: A SWATH OF SNOW WILL PROBABLY STILL ENCOMPASS MUCH OF THE FCST
AREA THRU THE MORNING...RESULTING IN PERIODS OF SNOW. IT WILL
DIMINISH AND END IN THE AFTERNOON.
CURRENT EXPECTATION IS THAT MOST IF NOT ALL THE ACCUMULATING SNOW
WILL FALL WED NIGHT. WHILE SNOW WILL CONT INTO THU THE LIFT WILL NOT
BE ENOUGH TO RESULT IN MUCH ACCUM.
SNOW RATIOS: THIS IS TOUGH BECAUSE THE MESOSCALE NATURE OF THIS
SYSTEM WILL RESULT IN HIGHLY NON-UNIFORM LIFT. HIGHER UPWARD
VERTICAL MOTION (UVM) WILL RESULT IN HIGHER RATIOS WITHIN THE BAND.
GIVEN THAT THE BAND SHOULD BE TRANSIENT...KEPT RATIOS IN THE 10-12
RANGE.
BASED ON NAM SOUNDINGS...UVM WILL BE FAIRLY GOOD BELOW THE DGZ FROM
I-80 SOUTH. WITH TEMPS WARMER THAN -5C...THIS WILL RESULT IN
SUBSTANTIAL RIMING AND RATIOS CLOSE TO 10:1...IE A WETTER SNOW. N OF
I-80...IF THE NAM IS CORRECT UVM WILL BE WEAK RESULTING IN LESSER
QUALITY/SMALLER FLAKES. THAT TOO SUPPORTS A LOWER RATIO OF 10 OR
LESS.
ACCUMS: THESE RATIOS OFFER 1-2" AND THAT IS THE OFFICIAL FCST AT
THIS POINT...WITH 3-4" POSSIBLE IN A SMALLER AREA WHERE THE BAND IS
MORE PERSISTENT. WE JUST DON`T KNOW WHERE THAT WILL OCCUR.
SNOW ALGORITHMS FROM THE 06Z/12Z 20KM GFS AND 12Z/18Z NAM OFFER 2-4"
ACROSS MUCH OF THE FCST AREA...WITH ISOLATED 6" AMTS POSSIBLE.
THE EC CONTS TO BE ON THE HEAVY SIDE OF THE GUIDANCE DISTRIBUTION
CONSISTENTLY DUMPING ABOUT .50" SOMEWHERE NEAR ROOKS/OSBORNE/
MITCHELL COUNTIES. THAT INCLUDES THE LAST 4 RUNS. HOWEVER...THE 12Z
EC ENSEMBLE MEAN PROBABILITY FOR .50" IN 24 HRS 10% OR LESS. SO THAT
CONSTRAINS ME FROM GETTING OVERLY EXCITED.
WINDS WILL NOT BE A FACTOR WITH THIS EVENT.
FRI: DECREASING CLOUDS AS SUBSIDENT NW FLOW MOVES IN. HIGH TEMPS
PROBABLY COLDER THAN NORMAL.
SAT: TEMPS AT LEAST NORMAL IF NOT ABOVE. SNOW ON THE GROUND IS A
HUGE MITIGATING FACTOR. OTHERWISE...WIDESPREAD HIGHS IN THE 40S AND
50S WOULD BE ON THE TABLE.
SUN-MON: INCREASING CLOUDS. COOLER. POSSIBLY A TOUGH OF LIGHT
PRECIP AS THE FRONT/TROF MOVE IN.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1149 AM CST TUE JAN 19 2016
TRICKY AT THE BEGINNING OF THE FORECAST AS LIGHT SNOW IS IN THE
PROCESS OF EXITING THE AREA. VISIBILITY SHOULD IMPROVE SHORTLY.
CEILINGS MAY BE QUITE VARIABLE...BUT SHOULD MAINLY BE WITHING THE
MVFR RANGE THROUGH MOST OF THE AFTERNOON. REDUCED VISIBILITY IS A
BIT OF A CONCERN LATE TONIGHT INTO WEDNESDAY MORNING...ESPECIALLY
TOWARD KEAR. LIGHT SOUTH SOUTHEAST WIND MAY ENCOURAGE DEVELOPMENT
OF BR. MODELS ARE NOT IN AGREEMENT WITH THIS AT ALL AND CONFIDENCE
IS LOW REGARDING VISIBILITY TONIGHT/WEDNESDAY MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...HALBLAUB
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
855 AM PST TUE JAN 19 2016
.SYNOPSIS...ANOTHER STORM SYSTEM WILL MOVE INTO THE REGION TODAY
BRINGING AREAS OF CLOUDS AND LOCALLY GUSTY WINDS. PRECIPITATION
CHANCES WILL MAINLY BE CONFINED TO THE SIERRA AND HIGHER ELEVATIONS
OF THE SOUTHERN GREAT BASIN. AFTER TODAY HIGH PRESSURE WILL BUILD
OVER THE REGION BRINGING DRY CONDITIONS AND ABOVE NORMAL
TEMPERATURES THROUGH THE END OF THE WEEK.
&&
.UPDATE...JUST SENT OUT AN UPDATE TO INCREASE THE POPS FOR TODAY
ACROSS MUCH OF THE REGION. FAIRLY POTENT STORM SYSTEM IS PUSHING
INTO CALIFORNIA NOW WITH THE BACK EDGE OF THE PRECIPITATION SHIELD
JUST NOW REACHING THE SAN FRANSISCO BAY AREA. THIS MOISTURE PLUME
WILL HEAD EAST TODAY AND WHILE MUCH OF THE PRECIP WILL BE
INTERCEPTED BY THE SIERRA...A DEEP MOISTURE TAP TRACEABLE BACK TO
THE HAWAIIAN ISLANDS WILL LEAD TO SOME SPILLOVER INTO THE DESERTS AND
SOUTHERN GREAT BASIN. ALL FORECAST MODELS HAVE BOOSTED LIKELIHOODS
OF RAINFALL TODAY...AND THE HRRR ADVERTISES A SMALL BAND OF RAINFALL
LIKELY TO PUSH EAST THIS AFTERNOON AND EVENING ACROSS THE DESERTS
AND INTO NORTHWEST ARIZONA BY LATE EVENING. IF IT
MATERIALIZES...SOME LIGHT RAIN OR SPRINKLES MAY AFFECT THE EVENING
COMMUTE IN THE VEGAS METRO.
-OUTLER-
&&
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT.
AS ONE SYSTEM EXITS THE REGION ANOTHER IS ALREADY STARTING TO MOVE
IN. HIGH CLOUDS WILL CONTINUE TO SPREAD OVER THE FORECAST AREA TODAY
AND WILL EVENTUALLY LOWER THROUGHOUT THE DAY. LIKE THE PREVIOUS
COUPLE OF SYSTEMS MUCH OF THE PRECIPITATION IS EXPECTED TO BE
INTERCEPTED BY THE SIERRA. HOWEVER...THIS SYSTEM MAY TAKE A TRACK
THAT WILL BRING IT A BIT FURTHER SOUTH ALLOWING FOR MORE
PRECIPITATION TO MAKE IT EAST OF THE SIERRA. THE LATEST MODEL RUNS
HAVE BEEN PROGRESSIVELY SHOWING HIGHER QPF AMOUNTS ACROSS CENTRAL
INYO...SAN BERNARDINO AND SOUTHERN NEVADA THROUGH 00Z THIS
AFTERNOON. EVEN THE LATEST HRRR HAS BEEN RAMPING UP ITS
PRECIPITATION COVERAGE WHICH SHOWS THE GREATEST POTENTIAL FOR
SHOWERS ACROSS THOSE AREAS BETWEEN 19Z-00Z. BASED ON THE LATEST RUNS
HAVE GONE AHEAD AND INCREASED POPS IN THE GRIDS. STILL THINK THAT
ANYTHING THAT DOES OCCUR EAST OF THE SIERRA WILL REMAIN LIGHT AND
AMOUNTS SHOULD GENERALLY RANGE FROM A TRACE TO A COUPLE OF
HUNDREDTHS WITH LIGHT SNOW ACCUMULATIONS IN THE HIGHER ELEVATIONS.
SHOWERS WILL THEN SPREAD EAST THIS EVENING WITH LIGHT AMOUNTS
EXPECTED ACROSS NORTHERN MOHAVE COUNTY BEFORE EXITING THE CWA
OVERNIGHT. WITH THE CLOUD COVER TODAY TEMPERATURES WILL BE HELD DOWN
SEVERAL DEGREES FROM YESTERDAY WITH READINGS CLOSE TO NORMAL.
HIGH PRESSURE IS THEN FORECAST TO DEVELOP OVER THE REGION WEDNESDAY
AND THURSDAY ALLOWING FOR DRY CONDITIONS AND TEMPERATURES WARMING TO
A FEW DEGREES ABOVE NORMAL. IT DOES LOOK LIKE THERE WILL BE ENOUGH
OF A SURFACE GRADIENT TO BRING GUSTY WINDS DOWN THE COLORADO RIVER
VALLEY WEDNESDAY NIGHT AND THURSDAY. AT THIS TIME WINDS DO NOT LOOK
TO BE STRONG ENOUGH FOR ANY ADVISORIES...BUT WINDS COULD STILL GUST
OVER 30 MPH...ESPECIALLY NEAR LAUGHLIN/BULLHEAD CITY.
.LONG TERM...FRIDAY THROUGH TUESDAY.
NOT MUCH CHANGE AGAIN TO THE LONG TERM PORTION OF THE FORECAST
TONIGHT. WE START WITH SHORTWAVE RIDGING MOVING OFF TO THE EAST IN
ADVANCE OF THE NEXT SYSTEM MOVING ONTO THE WEST COAST SOME TIME
BETWEEN 00Z AND 18Z SATURDAY BASED ON THE MODEL OF CHOICE. I AM
LEANING MORE WITH THE 00Z ECMWF TIMING (CLOSER TO 12Z-18Z SATURDAY)
GIVEN THE CLEAR TREND IN THE GFS TOWARD STRONGER RIDGING DOWNSTREAM
OF THE SYSTEM IN THE PAST 24 HOURS...SOMETHING THE ECMWF HAS BEEN
QUITE CONSISTENT ABOUT THE PAST FEW CYCLES. IN ADDITION, I AM
LEANING TOWARD THE SOMEWHAT DEEPER DEPICTION OF THE TROUGH OF THE
ECMWF COMPARED TO THE 00Z GFS...DESPITE CONSIDERABLE SUPPORT FROM
THE 00Z CMC/NAM FOR THE GFS SOLUTION. ENSEMBLE SOLUTIONS ARE
CONSIDERABLY MORE VARIED, AND AT LEAST A FEW MEMBERS SUGGEST THE
DEEPER/SLOWER APPEARANCE TO THE SYSTEM THE EURO HAS CONSISTENTLY
PROVIDED. ENSEMBLE MEANS ARE SOMEWHAT SLOWER THAN THE 00Z GFS
DETERMINISTIC SOLUTION AND THE RECENT 06Z RUN IS SLOWER/DEEPER THAN
ITS PREDECESSOR, PROVIDING ADDITIONAL SUPPORTING EVIDENCE FOR ME TO
LEAN ON THE SLOWER SIDE. GFS TENDS TO PROGRESS SYSTEMS INTO RIDGES
TOO QUICKLY, AND I SUSPECT THIS BIAS IS SHOWING UP TO SOME DEGREE.
NEVERTHELESS, FINAL GRIDS INCLUDED AT LEAST SOME CONTRIBUTION FROM
THE GFS BECAUSE OF SUBSTANTIALLY MORE SUPPORT FROM OTHER MODELS AND
FROM THE APPARENT SEASONAL BIAS OF THE ECMWF TO BE A BIT TOO
STRONG/SLOW WITH THESE PACIFIC SYSTEMS.
MODELS HAVE ALSO BEEN A LITTLE BIT MORE RELUCTANT TO START PRECIP IN
THE SIERRA DURING THE MORNING FRIDAY...SO I REDUCED POPS DURING THIS
TIME. CURRENTLY...ONSET TIMING SEEMS TO BE FRIDAY AFTERNOON/EVENING.
GFS/CMC SHUT DOWN PRECIP IN THE SIERRA QUICKLY...BY 12Z-18Z
SATURDAY...GIVEN THE FASTER/WEAKER DEPICTIONS OF TROUGH PASSAGE.
EURO KEEPS PRECIP AROUND THROUGH 00Z SUNDAY. I MAINTAINED POPS IN
THE SIERRA THROUGH THIS TIME...THOUGH THEY REMAIN IN THE SLIGHT
CHANCE CATEGORY BY THIS POINT. IF THE EURO SOLUTION VERIFIES...COULD
SEE SNOW AMOUNTS OF 6-12 INCHES ALONG THE SIERRA CREST. KEPT THEM A
BIT LOWER THAN THIS FOR NOW GIVEN THE MODEL UNCERTAINTY.
PRECIP FOR THE SOUTHERN GREAT BASIN IS FAR MORE UNCERTAIN AS THE
FARTHER NORTH TRACK OF THE GFS PROVIDES LITTLE TO NO PRECIP IN THIS
REGION WHEREAS THE ECMWF AND TO A LESSER DEGREE THE CMC PROVIDE AT
LEAST LIGHT ISOLATED/SCATTERED PRECIP THROUGH THE DAY SATURDAY. EURO
TENDS TO BE TOO AGGRESSIVE WITH PRODUCING PRECIP IN THIS AREA...AND
GIVEN THAT THE SIERRA WILL TAKE THE BRUNT OF THE PRECIP...KEPT VERY
LOW POPS IN FOR THIS REGION SATURDAY. TEMPERATURES FRIDAY AND
SATURDAY WILL BE ABOUT 2-7 DEGREES ABOVE NORMAL.
LONG-RANGE MODELS SHOW AT LEAST SOME INDICATION OF WEAK VORTICITY
MAXIMA MOVING THROUGH THE SOUTHWEST UPSTREAM OF THE SYSTEM PASSING
THROUGH ON SATURDAY. NO MATTER THE DEPICTION...LOOKS LIKE SUNDAY
WILL BE MOSTLY DRY AND COOLER AS NORTHERLY UPPER-LEVEL FLOW BECOMES
ESTABLISHED. AS THE TROUGH DEEPENS TO OUR EAST SUNDAY AND
MONDAY...HIGH AMPLITUDE RIDGING DEVELOPS ALONG THE WEST
COAST...PROVIDING OUR AREA STRONG NORTHERLY FLOW ALOFT FOR MONDAY
AND TUESDAY. THIS WILL LIKELY TRANSLATE TO BREEZY CONDITIONS IN THE
COLORADO RIVER VALLEY DURING THIS TIME. OTHERWISE...DRY CONDITIONS
AND NEAR NORMAL TEMPERATURES SHOULD START OUT THE NEW WEEK.
NEAR THE END OF THE LONG TERM...EURO FLATTENS THE NEWLY ESTABLISHED
RIDGE FAR MORE AGGRESSIVELY THAN THE GFS AS THE NEXT SYSTEM
APPROACHES THE WEST COAST. NEVERTHELESS...THE STORM TRACK REMAINS
TOO FAR NORTH AND THE SUBTROPICAL RIDGE IN THE EAST PACIFIC REMAINS
TOO STRONG TO PERMIT THIS SYSTEM TO AFFECT OUR AREA TO A SUBSTANTIAL
DEGREE. BEYOND THE LONG RANGE...ENSEMBLE SOLUTIONS HAVE CONSISTENTLY
INSISTED THAT THE SUBTROPICAL RIDGE IN THE EAST PACIFIC WILL
RETROGRESS AS FEBRUARY APPROACHES. IF SO...THIS WOULD AT LEAST
SUGGEST THAT MORE UNSETTLED WEATHER IS ON THE HORIZON. WE SHALL SEE.
&&
.AVIATION...FOR MCCARRAN...WINDS WILL GENERALLY REMAIN LIGHT AND
VARIABLE AT THE TERMINAL TODAY WINDS WIND SPEEDS REMAINING BELOW
6KTS THROUGH THE DAY. HIGH CLOUDS WILL GRADUALLY LOWER THIS MORNING
WITH CIGS AROUND 10K FEET BETWEEN 19Z-00Z THIS AFTERNOON. SCATTERED
SHOWERS ARE EXPECTED TO DEVELOP IN THE SPRING MOUNTAINS AND THERE IS
A SLIGHT CHANCE SHOWERS COULD WORK INTO THE VALLEY BETWEEN 20Z-00Z.
ANY PRECIPITATION THAT DOES FALL IS EXPECTED TO REMAIN LIGHT AND
CHANCES ARE TOO LOW TO INCLUDE IN THE TAF.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SOUTH WINDS WILL INCREASE MAINLY ACROSS
INYO...ESMERALDA...AND LINCOLN COUNTIES THIS AFTERNOON AROUND 10-15
KTS WITH WINDS LESS THAN 10KTS ELSEWHERE...EXCEPT WESTERN SAN
BERNARDINO COUNTY WHERE WEST WINDS 10-20KTS WILL OCCUR.
PRECIPITATION IS LIKELY ACROSS THE SIERRA CREST...BUT ISOLATED TO
SCATTERED SHOWERS ARE FORECAST TO DEVELOP EAST OF THE CREST ACROSS
THE REMAINDER OF THE AREA THIS AFTERNOON. CIGS RANGING FROM 8-10K
FEET. PRECIPITATION AMOUNTS ARE EXPECTED TO REMAIN LIGHT.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED.
PLEASE REPORT ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
$$
SHORT TERM/AVIATION...GORELOW
LONG TERM.............SHAFER
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
236 PM CST TUE JAN 19 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 229 PM CST TUE JAN 19 2016
LOOKS LIKE THE VERY COLD AIR WILL TAKE AN EXIT FOR AWHILE.
CONCERNS NOW FOR THIS SHORT TERM PERIOD WILL FOCUS ON THE
POTENTIAL FOR FOG TONIGHT. MESOSCALE MODELS HAVE BEEN CONSISTENTLY
FORECASTING A SHALLOW COOL AND MOIST BOUNDARY LAYER FREE OF
CLOUDS ABOVE. HRRR DEVELOPS WIDESPREAD LOW VISIBILITIES THIS
EVENING AND OVERNIGHT.
SATELLITE TRENDS SO FAR TODAY SHOW THE STRATUS LAYER ERODING
IN LOW LEVEL WARM ADVECTION ACROSS WESTERN NORTH DAKOTA. THIS
PROCESS WILL BE DISRUPTED THIS EVENING AS SUNSET APPROACHES.
DURING THE COOLING HOURS IN THE EVENING EXPECT FOG TO FORM IN THE
CLEARING ZONE WITH THE CLOUDS CREEPING BACK WEST. THIS WILL MAKE
MIN TEMPERATURES IN THE CLEARING AREA A CHALLENGE. SO FAR HAVE
ACCEPTED THE CONSSHORT GUIDANCE GIVING LOWER TEENS ACROSS THE
WEST AND SINGLE DIGITS ABOVE ZERO EAST.
ON WEDNESDAY THE NEXT SHORTWAVE IN A SERIES OF SHORTWAVES WILL
BRING AN INCREASE IN MID/HIGH CLOUDS AND BREAK OF THE BOUNDARY LAYER
FOG DURING FORENOON. A SLIGHT CHANCE OF SNOW SEEMS REASONABLE BY
LATE AFTERNOON FAR WEST. HIGH WEDNESDAY IN THE 20S TO MID 30S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 229 PM CST TUE JAN 19 2016
WEDNESDAY NIGHT THROUGH THURSDAY...COLD AIR ADVECTION AND A CHANCE
OF LIGHT SNOW WILL BEGIN POURING INTO SOUTHWEST NORTH DAKOTA
WEDNESDAY EVENING AS A SURFACE LOW AND ASSOCIATED MID LEVEL
SHORTWAVE SCOOT FROM SOUTHEAST MONTANA INTO SOUTH DAKOTA. THIS WILL
BE FOLLOWED BY ANOTHER SHORTWAVE THURSDAY...AS IT MOVES FROM WEST TO
EAST DURING THE DAY. THERE HAD BEEN SOME CONCERN FOR LIGHT FREEZING
RAIN WEDNESDAY EVENING...BUT THE NAM/SREF/GFS BUFKIT SOUNDINGS
INDICATE THAT IF IT DID DEVELOP...IT WOULD BE BRIEF...WITH A FAIRLY
QUICK TRANSITION TO LIGHT SNOW. NOT SEEING AN EXTENDED PERIOD OF
UPWARD VERTICAL MOTION WITH WITHIN THE SUPERCOOLED WATER DROPLET
REGIME...AND THE TRANSITION TIME FOR ANY GIVEN SOUNDING TO REACH
COLDER/HIGHER LEVELS OF SATURATION IS ACHIEVED FAIRLY QUICKLY
WEDNESDAY NIGHT. THUS...GIVEN THE BRIEF TIME AND ISOLATED COVERAGE
OF LIGHT FREEZING RAIN POTENTIAL...HAVE DECIDED TO STICK WITH THE
GIVEN FORECAST WHICH KEEPS A MENTION OF ONLY LIGHT SNOW. WILL
REVISIT THE SOUNDINGS AGAIN TONIGHT AND WEDNESDAY FOR ANY
SIGNIFICANT CHANGES TO THE ABOVE THINKING. OTHERWISE...CHANCES FOR
LIGHT SNOW WILL EXPAND INTO CENTRAL NORTH DAKOTA THROUGH THE DAY
THURSDAY. SNOWFALL ACCUMULATIONS THROUGH THURSDAY EVENING ARE
FORECAST AROUND A HALF INCH WEST AND CENTRAL...WITH AN ISOLATED SPOT
OF ONE INCH IN THE SOUTHWEST. THE CHANCE OF LIGHT SNOW EXITS THE
SOUTHERN JAMES RIVER VALLEY THURSDAY EVENING. WITH ONGOING COLD AIR
ADVECTION...HIGH TEMPERATURES THURSDAY WILL BE 5 TO 10 DEGREES
COLDER FROM WEDNESDAY...WHICH PUTS HIGHS THURSDAY FROM AROUND 10F
ABOVE IN THE TURTLE MOUNTAINS TO 25F SOUTHWEST.
THURSDAY NIGHT THROUGH SATURDAY...FOLLOWING THE ABOVE SHORTWAVE IS
AN UPPER LEVEL RIDGE WHICH WILL SHIFT FROM THE NORTHERN ROCKIES INTO
THE NORTHERN HIGH PLAINS FRIDAY INTO MOST OF SATURDAY. STRONG LOW
LEVEL WARM AIR ADVECTION FRIDAY AND SATURDAY WILL RESULT IN A
MODERATING TREND ALONG WITH DRY CONDITIONS. HIGHS FRIDAY WILL RANGE
FROM AROUND 20 IN THE JAMES RIVER VALLEY TO 40 WEST. BY SATURDAY
HIGHS WILL RANGE BETWEEN 30F AND 40F ACROSS WESTERN AND CENTRAL
NORTH DAKOTA.
THE WARMING TREND WILL COME TO AN END SATURDAY EVENING...AS A COLD
FRONT SWEEPS FROM NORTHWEST TO SOUTHEAST. THIS LEADS TO A CHANCE OF
SNOW AND COLDER TEMPERATURES SUNDAY. HIGHS SUNDAY THROUGH TUESDAY
ARE NEARLY THE SAME EACH DAY WITH HIGHS IN THE UPPER TEENS IN THE
TURTLE MOUNTAINS TO 20S ELSEWHERE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 229 PM CST TUE JAN 19 2016
A WARM FRONT ACROSS WESTERN NORTH DAKOTA CLEARING CLOUDS FROM
KISN-KDIK EAST TO NEAR THE MISSOURI RIVER. MVFR TO IFR CONDITIONS
PERSIST CENTRAL(KMOT- KBIS- KJMS). LOW LEVEL MOIST BOUNDARY LAYER
WILL RETURN WESTWARD THIS EVENING. EXPECT LOW IFR CONDITIONS TO
DEVELOP IN FZFG KISN-KDIK AFTER 02Z AND IFR CONDITIONS IN BR
KISN-KMOT-KBIS-KJMS AS WELL.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WAA
LONG TERM...KS
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1245 PM EST TUE JAN 19 2016
.SYNOPSIS...
COLD CONTINUES TODAY AND TONIGHT UNDER HIGH PRESSURE AND LIGHTER WINDS.
WEAKENING SYSTEM WEDNESDAY COULD LEAVE MINOR SNOW ACCUMULATIONS. A
MAJOR WINTER STORM DEVELOPS THURSDAY NIGHT AND LINGERS INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
CLOUDS SLOW TO ERODE...BUT ARE IN FACT DOING SO AT THIS HOUR...AND
SHOULD BE CLEARING AS WE HEAD INTO THE AFTERNOON HOURS TODAY. SENT
SOME REVAMPED SKY COVER GRIDS...AND WILL KEEP THE FLURRIES OUT AS
OBSERVATIONS WITH SNOW/FLURRIES ARE COMING FEW AND FAR BETWEEN.
PREVIOUS DISCUSSION BELOW...
PESKY STRATOCU HOLDING STRONG IN THE MOUNTAINS WITH SCT FLURRIES
OR ICE CRYSTALS FALLING. OUTSIDE OF THAT...A PASSING S/W TROF MAY
BRING SOME CLOUDS INTO THE AREA THRU MORNING...ESPECIALLY ACROSS
NE KY/S WV/ AND SW VA WHERE A PASSING FLURRY CANNOT BE RULED OUT.
HIGH PRESSURE BUILDS INTO THE REGION TODAY WHICH WILL FURTHER
DIMINISH THE WIND. STILL COULD SEE SOME GUSTS IN THE N MOUNTAINS
THOUGH. HI RES MODELS TRYING TO SHOW SOME AFTERNOON STREAKY STRATOCU
DEVELOPING OVER SE OH AND N WV AGAIN TODAY. BUMPED SKY COVER UP A
BIT THERE BUT NOT TO THE DEGREE THE HRRR WOULD SUGGEST. TEMPS TODAY
SHOULD RECOVER ABOUT 5 DEGREES FROM YESTERDAY BUT STILL COLD
OVERALL.
WITH HIGH PRESSURE OVERHEAD TONIGHT...EXPECTING A QUICK FALL IN
TEMPS THIS EVENING...ESPECIALLY OVER AREAS THAT HAVE SNOW ON THE
GROUND. HOWEVER...MID AND HI CLOUDS WILL BE ADVANCING TOWARD THE
AREA LATE WHICH WILL CAP THE FREE FALL. WAA ALOFT WILL ALSO COMMENCE
WHICH SHOULD ALLOW THE HIGHER ELEVATIONS TO SEE A SLOW RISE
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
THE WEAKENING SUPPORT/LIFT ON WEDNESDAY WILL WORK HARD TO SATURATE THE COLUMN
IN THE INITIALLY DRY ARCTIC AIR.
FEATURE IS A COMBO OF A 500 MB TROF AND WARM AIR ADVECTION IN THE LOW LEVELS.
FOR EXAMPLE...THE 850 MB FLOW OF 30 TO 40 KNOTS IS PERPENDICULAR TO THE
850 MB ISOTHERMS VCNTY STL TUESDAY EVENING. BY 18Z WEDNESDAY...THE FLOW
IS ALMOST PARALLEL TO THE ISOTHERMS. NOT MUCH CHANGE TO OUR 1 TO 2 INCH
FORECAST...BUT DID TRY TO DAMPEN THE NORTHERN COUNTIES...INCLUDING THE
ROUTE 50 CORRIDOR TO MOSTLY AN INCH OR LESS OF SNOW ACCUMULATION ON
WEDNESDAY.
MEANWHILE...TRIED TO BOOST PORTIONS OF NORTHEAST KENTUCKY...THE SOUTHERN
COAL FIELDS OF WEST VIRGINIA...BUCHANAN AND DICKENSON COUNTIES IN VIRGINIA
MORE TOWARD THE 2 INCH ACCUMULATION. IF SYSTEM DOES NOT DAMPEN QUICKER
THAN EXPECTED...WINTER WX ADVISORIES WILL LIKELY BE POSTED IN SOME COUNTIES
THAT HAVE THE 2 INCH CRITERIA...WHICH IS THE SAME THEME AS YESTERDAY.
WILL CUT BACK ON HIGH TEMPERATURES IN THE SOUTHWEST ON WEDNESDAY...WHERE
THE SNOW WILL LIKELY REACH THE GROUND IN THE MORNING.
WEDNESDAY SYSTEM LEAVES THE LOW ELEVATIONS SATURATED...COULD NOT COMPLETELY
RULE OUT SOME FREEZING DRIZZLE IN THE MOUNTAINS OR SOUTHERN COUNTIES OVERNIGHT
WEDNESDAY NIGHT IN THE WAKE OF THE SYNOPTIC LIGHT SNOW. YET...WILL NOT INSERT
YET INTO THE FORECAST. NORTHERN COUNTIES HAVE A BETTER CHANCE OF THE
LOWER CLOUDS BREAKING UP BEFORE DAWN THURSDAY.
WILL SLOW DOWN THE INCREASING POPS LATE THURSDAY IN THE EXTREME SOUTH A
FEW HOURS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ON THE MIDNIGHT SHIFT THIS TUESDAY MORNING...NO REASON TO MAKE MAJOR CHANGES
TO OUR GRIDS FOR THE MAJOR STORM. AS WE KNOW...MAJOR ADJUSTMENTS ARE WISER
AS WE GET CLOSER...INSTEAD OF SEESAWING DAYS AWAY.
WITH THE MID LEVEL AND 850 MB LOW STILL TO OUR WEST ON FRIDAY...AND A STRONG
SOUTHERLY 40 KNOT 850 MB FLOW INTO SOUTHERN WEST VIRGINIA...WE STILL LIKE
THE FORECAST RAIN WORKING NORTH OVERNIGHT THURSDAY NIGHT INTO FRIDAY
FOR SOUTHERN COUNTIES. WILL NOT ADD A WATER HAZARD AS OF YET...BUT
AGAIN...EVEN THAT COULD NOT BE COMPLETELY RULED OUT FOR SOUTHERN
COUNTIES.
HOW FAR AND QUICKLY THAT WINTRY MIX WORKS NORTH...IS THE QUESTION.
WITH SOME SE COMPONENT THOUGH IN POCAHONTAS COUNTY...WE STILL LIKE
KEEPING MOSTLY SNOW IN POCAHONTAS COUNTY.
00Z ECMWF STILL A BIT FURTHER SOUTH WITH THE MID LEVEL AND 850 MB LOW
CIRCULATION...AND THUS A BIT COLDER AT CRITICAL 850 MB LEVEL.
DID INCREASE POPS FRIDAY NIGHT INTO SATURDAY MORNING IN THE STRONG WRAP
AROUND FROM THE DEEPENING STORM TO OUR EAST.
REST OF THIS LONG TERM IS FROM OUR LATE MONDAY PACKAGE...
MODELS AGREE ON THE POTENTIAL FOR A MAJOR WINTER WEATHER SYSTEM
IMPACTING THE AREA EARLY IN THE PERIOD.
A MIDSTREAM UPPER LEVEL S/W TROUGH DIGS SEWD THROUGH THE SRN
PLAINS STATES THU...TOWARD A L/W TROUGH POSITION E OF THE
MISSISSIPPI RIVER...WITH A RIDGE BUILDING TO ITS W. THE S/W
TROUGH CLOSES OFF FRI...TRACKS ACROSS THE SRN APPALACHIANS FRI
NT...AND THEN MEANDERS UP ALONG THE ERN SEABOARD ON SAT.
THE INITIAL SFC LOW CENTER TRACKS NEWD INTO SE KY AND SW VA THU
EVENING...WITH THE INVERTED LOW LEVEL TROUGH EXTENDING NWD UP
ALONG THE OHIO RIVER...PEAKING THE WARM WEDGE EFFECT AT THAT TIME.
THAT CENTER THEN FILLS OVERNIGHT AS THE NEW LOW CENTER GETS GOING
ALONG THE EASTERN SEABOARD. THAT CENTER SLOWLY MEANDERS UP THE
EASTERN SEABOARD SAT AND SAT NT...BEFORE FINALLY PULLING OUT TO
SEA ON SUNDAY.
THIS SCENARIO IS LIKELY TO RESULT IN SNOW OVERSPREADING THE AREA
FROM S TO N THU NT...WITH A TRANSITION TO SLEET AND THEN RAIN
INTO CENTRAL PORTIONS OF THE FCST AREA FROM THE S. FREEZING RAIN
IS ALSO POSSIBLE IN THE TRANSITION. THE HIGHEST LOW LEVEL
TEMPERATURES WILL OCCUR IN THE WARM WEDGE BETWEEN THE OHIO RIVER
AND THE WV MOUNTAINS. SFC TEMPERATURES SHOULD PEAK MID TO LATE
AFTERNOON FRI...BUT THE WARM WEDGE ALOFT STARTS PUSHING EWD LATE
FRI AFTERNOON. THIS COMBINATION KEEPS THE FREEZING RAIN POTENTIAL
IN THE MORNING AND MIDDAY FRI...MAINLY FOR SRN PORTIONS OF THE
AREA AND ALONG THE ERN SLOPES OF THE SRN WV MOUNTAINS.
ACCUMULATIONS THU NT AS LIKELY TO BE LIMITED OVER THE SRN COAL
FIELDS OF WV ON ACCOUNT OF SFC TEMPERATURES THERE GETTING ABOVE
FREEZING SOON AFTER THE ONSET OF THE PRECIPITATION. AN INCH OR
TWO ARE POSSIBLE ELSEWHERE BY DAWN FRI...DEPENDING UPON HOW
QUICKLY SLEET MIXES IN RELATIVE TO THE ONSET TIME OF THE
PRECIPITATION. THE CENTRAL MOUNTAINS APPEAR MOST LIKELY TO GET
SEVERAL INCHES BY DAWN FRI AS THAT IS WHERE THERE IS LIKELY TO BE
THE MOST TIME BETWEEN THE ONSET OF THE PRECIPITATION AND THE
ARRIVAL OF ABOVE FREEZING TEMPERATURES ALOFT.
AS THE UPPER LEVEL LOW ROLLS S OF THE AREA FRI NT...THE LOW LEVEL
INVERTED TROUGH AND WARM WEDGE COLLAPSE...AND TEMPERATURES FALL
BELOW FREEZING THROUGHOUT THE COLUMN THROUGHOUT THE FCST AREA.
SNOW ACCUMULATIONS WILL DEPEND UPON THE PROGRESS OF THE WARM
WEDGE ON FRI...AND THEN HOW MUCH FORCING / DEFORMATION EXISTS OVER
THE AREA FRI NT AS THE COLD AIR SETTLES IN.
THE AIR MASS BEHIND THIS SYSTEM WILL ACTUALLY BE OF PACIFIC ORIGIN
AND THUS BE ONLY SEASONABLY CHILLY...AND THE NEXT WARM ADVECTION
SYSTEM NEXT MON BRINGS THE CHANCE FOR A LIGHT SNOW TO RAIN
TRANSITION.
WPC TEMPERATURES LOOKED REASONABLE AND WERE GENERALLY BLENDED IN.
HAVE TEMPERATURES RISING TOWARD DAWN FRI WITH THE WARM WEDGE
EFFECT BEGINNING TO TAKE HOLD...USED GFS BASED TEMPERATURES IN
ADDITION TO WPC DURING THE STORM...THU NT INTO SAT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
STILL HAVING TROUBLE GETTING THE STRATOCU TO DISSIPATE...BUT NOW
SEEING A FEW BREAKS IN THAT DECK HERE AND THERE. CARRY THE MVFR
CEILINGS AT LOCATIONS FOR ANOTHER HOUR OR TWO...AND IT SHOULD
LIFT SLIGHTLY TO ABOVE VFR AT THAT TIME.
NEXT SYSTEM MAKES ITS APPEARANCE IN TERMS OF HIGH LEVEL CIRRUS
AFTER 03Z WEDNESDAY...WITH STEADILY LOWERING CEILINGS THROUGH THE
DAY ON WEDNESDAY. BY 18Z...MVFR HEIGHTS REACH THE TUG FORK
VALLEY...BUT WILL NOT PUT ANY MVFR IN THE TAFS BY THE END OF THE
18Z WEDNESDAY TIME FRAME.
SURFACE WINDS DECREASE AND TURN INTO LIGHT AND VARIABLE THIS
EVENING AND TONIGHT AS HIGH PRESSURE PASSES OVER THE AREA.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE...HIGH
ALTERNATE SCENARIOS: NONE
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 15 16 17 18 19 20 21 22 23 00 01 02
EST 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY M M 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 M M H H H H H H H H H H
EKN CONSISTENCY M M M M M M M M H H H H
PKB CONSISTENCY H H M M M M M M H H H H
CKB CONSISTENCY M M M M M M M M H H H H
AFTER 18Z WEDNESDAY...
UPPER AIR DISTURBANCE WEDNESDAY/WEDNESDAY NIGHT COULD BRING LIGHT SNOW
WITH IFR.
WIDESPREAD IFR LIKELY WITH A WINTER STORM SYSTEM THURSDAY NIGHT
INTO SATURDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/30
NEAR TERM...30/26
SHORT TERM...KTB
LONG TERM...TRM
AVIATION...26