Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/04/13
AREA FORECAST DISCUSSION
NWS ALBANY NY
245 AM EST MON DEC 2 2013
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR PLENTY OF CLOUDS
THROUGH EARLY MORNING...ALONG WITH THE POSSIBILITY OF SOME LIGHT
SNOW SHOWERS AND OR PATCHY LIGHT FREEZING DRIZZLE. THEN MAINLY DRY
CONDITIONS WILL PREVAIL THROUGHOUT THE REMAINDER OF THE DAY WITH
SEASONABLE TEMPERATURES. TEMPERATURES WILL BECOME ABOVE NORMAL
TOWARDS THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 245 AM...STILL PICKING LIGHT RETURNS (GENERALLY AROUND 20 DBZ
OR LESS) OFF KENX RADAR. GROUND TRUTH INDICATED VERY LITTLE IF ANY
ADDITIONAL PRECIPITATION WAS FALLING ACROSS OUR REGION SINCE REPORTS
EARLIER IN THE EVENING.
WE WILL CONTINUE THE IDEA OF LOW CHANCES OF A LIGHT WINTRY MIX
(MAINLY LIGHT SNOW AND OR LIGHT FREEZING DRIZZLE) WEST OF THE HUDSON
VALLEY...SLIGHT CHANCES HUDSON VALLEY AND AREAS EAST OF IT...THROUGH
THE MORNING DRIVE. WE WILL CONTINUE TO MONITOR AND ISSUE ANY SPECIAL
WEATHER STATEMENTS SHOULD IT BECOME MORE OBVIOUS THERE WILL BE A
PROBLEM.
PATCHY FOG ALSO REMOTELY POSSIBLE SO WILL KEEP IT IN THE FORECAST.
MINIMUM TEMPERATURES HAVE PRETTY MUCH BOTTOMED OUT...AND SHOULD STAY
WITHIN A FEW DEGREES OF 30 THROUGH THE EARLY MORNING.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH WEDNESDAY/...
THE LATEST HRRR DID INDICATE THE BEST CHANCES OF LIGHT PRECIPITATION
IN THE CAPITAL REGION WOULD BE UNFORTUNATELY AROUND THE MORNING
DRIVE. WHILE NOT TOTALLY BUYING INTO THIS IDEA...WE DID CONTINUE
SLIGHT CHANCES FOR PATCHY LIGHT FREEZING DRIZZLE AND OR LIGHT SNOW
SHOWER INTO THE MORNING HOURS. AFTER THAT TIME...THE WEAK SYSTEM
SHOULD MOVE ON BUY. CLOUDS COULD THIN ENOUGH FOR A BREAK OR TWO OF
SUNSHINE.
OUR REGION WILL REMAIN BETWEEN SYSTEMS. CLOUDS WILL DOMINATE INTO
TUESDAY. TEMPERATURES ARE EXPECTED TO CONTINUED TO BE SEASONABLE.
THE LONGWAVE TROUGH OVER THE REGION WILL DEEPEN BECOMING NEGATIVELY
TILTED OFF NEW ENGLAND COAST TUESDAY. THE MODEL GUIDANCE IS IN MUCH
BETTER AGREEMENT AND DEVELOP A LOW OFF THE SOUTHEAST COAST MONDAY
THEN TRACK IN NORTHEASTWARD AND KEEPING IT WELL OFFSHORE. IT IS
EXPECTED TO REACH NOVA SCOTIA TUESDAY NIGHT. SOME RIDGING WILL
BUILD IN AT ALL LEVELS TUESDAY NIGHT AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STORM SYSTEM WILL BE MOVING FROM THE GREAT LAKES ON WEDNESDAY
EVENING TOWARDS JAMES BAY FOR THURSDAY.
THIS STORM/S WARM FRONT LOOKS TO MOVE ACROSS OUR REGION ON WED
NIGHT...WITH STRONG WARM AIR ADVECTION TAKING PLACE. 850 HPA TEMPS
WILL SURGE AS HIGH AS +9 ACROSS OUR REGION BY THURSDAY MORNING.
ALTHOUGH MOISTURE WILL BE LIMITED...SOME LIGHT PRECIPITATION IS
EXPECTED OVERNIGHT...ESP FOR THE NORTHERN AND WESTERN PARTS OF THE
AREA. WITH THE WARMING TEMPS ALOFT...PRECIP WILL EITHER BE RAIN OR
FREEZING RAIN...WITH PTYPE DEPENDENT ON SURFACE TEMPS. MOST AREAS
LOOK TO HAVE LOW TEMPS IN THE UPPER 20S TO MID 30S IN THE EVENING
JUST BEFORE OR AT THE START OF WHEN PRECIP BEGINS...WITH TEMPS
RAPIDLY WARMING OVERNIGHT THROUGH THE 30S AND EVEN INTO THE 40S FOR
SOME AREAS. SOME SHELTERED ELEVATED VALLEYS OF THE ADIRONDACKS MAY
HANG ON TO THE SUB FREEZING AIR THE LONGEST...AND THIS IS WHERE THE
BEST THREAT FOR ANY FREEZING RAIN WILL BE. MOST LARGER
VALLEYS...SUCH AS THE HUDSON VALLEY...SHOULD ONLY SEE LIQUID
PRECIP...AS TEMPS LOOK TO BE ABOVE FREEZING DURING THE TIME OF
PRECIP. THE STORM/S COLD FRONT MAY ALLOW FOR SOME ADDITIONAL RAIN
SHOWERS DURING THE DAY ON THURSDAY...ALTHOUGH PRECIP WILL LIKELY BE
RATHER SPOTTY...AS THE BEST FORCING WILL BE WELL NORTHWEST OF THE
AREA AND THERE WON/T BE A GOOD DEAL OF MOISTURE PRESENT. MAX TEMPS
WILL BE ABOVE NORMAL...WITH 40S TO LOW 50S ACROSS THE AREA AHEAD OF
THE BOUNDARY.
BEHIND THIS FRONT...COLDER AIR WILL BEGIN TO MOVE TOWARDS THE REGION
ON FRIDAY. ALTHOUGH THE CORE OF THE COLD AIR WILL REMAIN OVER THE
NORTHERN PLAINS INITIALLY...TEMPS WILL TURN PROGRESSIVELY COLDER
THROUGH THE UPCOMING WEEKEND...WITH TEMPS NEAR OR SLIGHTLY BELOW
NORMAL BY SUNDAY. THE COLD FRONT THAT MOVED THROUGH THE REGION ON
THURSDAY WILL STALL SOUTH OF THE AREA ACROSS THE MID ATLANTIC STATES
FOR LATE IN THE WEEK. WAVES OF LOW PRESSURE MAY DEVELOP ALONG THIS
BOUNDARY AND RIDE NORTHEASTWARD ALONG IT. IF THIS FRONT REMAINS
CLOSE ENOUGH TO OUR AREA...SOME RAIN OR SNOW MAY BE POSSIBLE...ESP
FOR THE SOUTHERN HALF OF THE AREA. THE MODELS ARE UNCLEAR EXACTLY
WHERE OR IF THIS FRONT WILL STALL...AND JUST HOW COLD IT WILL BE
OVER OUR AREA. FOR NOW...WILL GO WITH CHC POPS FOR THURSDAY NIGHT
THROUGH FRIDAY NIGHT...WITH SLIGHT CHC/LOW CHC POPS FOR SAT...WITH
PRECIP RAIN OR SNOW...AND PTYPE BASED ON ELEVATION/DIURNAL TEMP
TRENDS.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SCT-BKN CIGS WITH AN OCCASIONAL REDUCTION IN VISIBILITY DUE TO
MIST/BR BUT REMAINING MVFR FLIGHT CATEGORIES ARE ANTICIPATED.
WHILE MOST OF THE TIME WILL BE DRY...A COUPLE OF OPPORTUNITIES FOR A
BRIEF LIGHT SNOW SHOWER OVERNIGHT AND ONCE AGAIN THIS AFTERNOON.
OTHERWISE...DUE TO LIMITED MOISTURE AND WEAK FORCING NOTHING
EXPECTED TO BE ORGANIZED.
WINDS WILL BE CALM OVERNIGHT...AND BECOME LIGHT OUT OF THE S-SE ON
MONDAY...GENERALLY AT LESS THAN 5 KTS.
OUTLOOK...
MON NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX.
WED NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA. CHC FZRA
MAINLY ACROSS THE HIGHER TERRAIN.
THU: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED OVER THE NEXT FEW DAYS.
ANY PRECIPITATION WILL BE LIGHT.
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...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/HWJIV
NEAR TERM...FRUGIS/HWJIV
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1233 AM EST MON DEC 2 2013
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR PLENTY OF CLOUDS
OVERNIGHT...ALONG WITH THE POSSIBILITY OF SOME LIGHT SNOW SHOWERS
AND OR PATCHY LIGHT FREEZING DRIZZLE THROUGH THE EARLY MORNING
HOURS. THEN MAINLY DRY CONDITIONS WILL PREVAIL THROUGHOUT THE DAY
WITH SEASONABLE TEMPERATURES. TEMPERATURES WILL BECOME ABOVE NORMAL
TOWARDS THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF MIDNIGHT...KENX RADAR WAS PICKING UP SOME LIGHT RETURNS
HEADING INTO THE CAPITAL REGION. HAD ONE REPORT OFF FACEBOOK OF
LIGHT SNOW CHANGING TO LIGHT FREEZING DRIZZLE BUT THEN BACK TO LIGHT
SNOW TO THE WEST OF THE HUDSON VALLEY.
THE ATMOSPHERE WAS SATURATING UP AS EXPECTED EARLIER.
NOT SURE IT WOULD JUST BE PATCHY FREEZING DRIZZLE THAT WOULD FALL
WITH THE RETURNS. CLOUD DECKS ARE ELEVATED AND ACCORDING TO OUR
SOUNDING...COULD SUPPORT LIGHT SNOW OR FREEZING DRIZZLE.
FOR THIS UPDATE...JUST ASSIGNED A 20 POP TO ALL OF THE
REGION...WHILE KEEP 30 POPS WEST OF THE HUDSON VALLEY. ALSO...ADDED
LIGHT SNOW SHOWERS TO ALL AREAS (ALONG WITH THE PATCHY LIGHT
FREEZING DRIZZLE). HOWEVER...MANY AREAS WILL LIKELY REMAIN DRY WITH
NO PRECIPITATION. IT WILL BE A HIT A MISS SCENARIO.
NO REAL CHANGES TO OVERNIGHT TEMPS. WITH THE CLOUDS...THEY SHOULD BE
PRETTY CLOSE TO AROUND 30 FOR AN OVERNIGHT LOW REGION WIDE (A LITTLE
COLDER IN THE MOUNTAINS).
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
THE LATEST HRRR DID INDICATE THE BEST CHANCES OF LIGHT PRECIPITATION
IN THE CAPITAL REGION WOULD BE UNFORTUNATELY AROUND THE MORNING
DRIVE. WHILE NOT TOTALLY BUYING INTO THIS IDEA...WE DID CONTINUE
SLIGHT CHANCES FOR PATCHY LIGHT FREEZING DRIZZLE AND OR LIGHT SNOW
SHOWER INTO THE MORNING HOURS. AFTER THAT TIME...THE WEAK SYSTEM
SHOULD MOVE ON BUY. CLOUDS COULD THIN ENOUGH FOR A BREAK OR TWO OF
SUNSHINE.
OUR REGION WILL REMAIN BETWEEN SYSTEMS. CLOUDS WILL DOMINATE INTO
TUESDAY. TEMPERATURES ARE EXPECTED TO CONTINUED TO BE SEASONABLE.
THE LONGWAVE TROUGH OVER THE REGION WILL DEEPEN BECOMING NEGATIVELY
TILTED OFF NEW ENGLAND COAST TUESDAY. THE MODEL GUIDANCE IS IN MUCH
BETTER AGREEMENT AND DEVELOP A LOW OFF THE SOUTHEAST COAST MONDAY
THEN TRACK IN NORTHEASTWARD AND KEEPING IT WELL OFFSHORE. IT IS
EXPECTED TO REACH NOVA SCOTIA TUESDAY NIGHT. SOME RIDGING WILL
BUILD IN AT ALL LEVELS TUESDAY NIGHT AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STORM SYSTEM WILL BE MOVING FROM THE GREAT LAKES ON WEDNESDAY
EVENING TOWARDS JAMES BAY FOR THURSDAY.
THIS STORM/S WARM FRONT LOOKS TO MOVE ACROSS OUR REGION ON WED
NIGHT...WITH STRONG WARM AIR ADVECTION TAKING PLACE. 850 HPA TEMPS
WILL SURGE AS HIGH AS +9 ACROSS OUR REGION BY THURSDAY MORNING.
ALTHOUGH MOISTURE WILL BE LIMITED...SOME LIGHT PRECIPITATION IS
EXPECTED OVERNIGHT...ESP FOR THE NORTHERN AND WESTERN PARTS OF THE
AREA. WITH THE WARMING TEMPS ALOFT...PRECIP WILL EITHER BE RAIN OR
FREEZING RAIN...WITH PTYPE DEPENDENT ON SURFACE TEMPS. MOST AREAS
LOOK TO HAVE LOW TEMPS IN THE UPPER 20S TO MID 30S IN THE EVENING
JUST BEFORE OR AT THE START OF WHEN PRECIP BEGINS...WITH TEMPS
RAPIDLY WARMING OVERNIGHT THROUGH THE 30S AND EVEN INTO THE 40S FOR
SOME AREAS. SOME SHELTERED ELEVATED VALLEYS OF THE ADIRONDACKS MAY
HANG ON TO THE SUB FREEZING AIR THE LONGEST...AND THIS IS WHERE THE
BEST THREAT FOR ANY FREEZING RAIN WILL BE. MOST LARGER
VALLEYS...SUCH AS THE HUDSON VALLEY...SHOULD ONLY SEE LIQUID
PRECIP...AS TEMPS LOOK TO BE ABOVE FREEZING DURING THE TIME OF
PRECIP. THE STORM/S COLD FRONT MAY ALLOW FOR SOME ADDITIONAL RAIN
SHOWERS DURING THE DAY ON THURSDAY...ALTHOUGH PRECIP WILL LIKELY BE
RATHER SPOTTY...AS THE BEST FORCING WILL BE WELL NORTHWEST OF THE
AREA AND THERE WON/T BE A GOOD DEAL OF MOISTURE PRESENT. MAX TEMPS
WILL BE ABOVE NORMAL...WITH 40S TO LOW 50S ACROSS THE AREA AHEAD OF
THE BOUNDARY.
BEHIND THIS FRONT...COLDER AIR WILL BEGIN TO MOVE TOWARDS THE REGION
ON FRIDAY. ALTHOUGH THE CORE OF THE COLD AIR WILL REMAIN OVER THE
NORTHERN PLAINS INITIALLY...TEMPS WILL TURN PROGRESSIVELY COLDER
THROUGH THE UPCOMING WEEKEND...WITH TEMPS NEAR OR SLIGHTLY BELOW
NORMAL BY SUNDAY. THE COLD FRONT THAT MOVED THROUGH THE REGION ON
THURSDAY WILL STALL SOUTH OF THE AREA ACROSS THE MID ATLANTIC STATES
FOR LATE IN THE WEEK. WAVES OF LOW PRESSURE MAY DEVELOP ALONG THIS
BOUNDARY AND RIDE NORTHEASTWARD ALONG IT. IF THIS FRONT REMAINS
CLOSE ENOUGH TO OUR AREA...SOME RAIN OR SNOW MAY BE POSSIBLE...ESP
FOR THE SOUTHERN HALF OF THE AREA. THE MODELS ARE UNCLEAR EXACTLY
WHERE OR IF THIS FRONT WILL STALL...AND JUST HOW COLD IT WILL BE
OVER OUR AREA. FOR NOW...WILL GO WITH CHC POPS FOR THURSDAY NIGHT
THROUGH FRIDAY NIGHT...WITH SLIGHT CHC/LOW CHC POPS FOR SAT...WITH
PRECIP RAIN OR SNOW...AND PTYPE BASED ON ELEVATION/DIURNAL TEMP
TRENDS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SCT-BKN CIGS WITH AN OCCASIONAL REDUCTION IN VISIBILITY DUE TO
MIST/BR BUT REMAINING MVFR FLIGHT CATEGORIES ARE ANTICIPATED.
WHILE MOST OF THE TIME WILL BE DRY...A COUPLE OF OPPORTUNITIES FOR A
BRIEF LIGHT SNOW SHOWER OVERNIGHT AND ONCE AGAIN THIS AFTERNOON.
OTHERWISE...DUE TO LIMITED MOISTURE AND WEAK FORCING NOTHING
EXPECTED TO BE ORGANIZED.
WINDS WILL BE CALM OVERNIGHT...AND BECOME LIGHT OUT OF THE S-SE ON
MONDAY...GENERALLY AT LESS THAN 5 KTS.
OUTLOOK...
MON NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX.
WED NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA. CHC FZRA
MAINLY ACROSS THE HIGHER TERRAIN.
THU: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED OVER THE NEXT FEW DAYS.
ANY PRECIPITATION WILL BE LIGHT.
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...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/HWJIV
NEAR TERM...FRUGIS/HWJIV
SHORT TERM...IAA/HWJIV
LONG TERM...FRUGIS
AVIATION...BGM
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1159 PM EST SUN DEC 1 2013
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR PLENTY OF CLOUDS
OVERNIGHT...ALONG WITH THE POSSIBILITY OF SOME LIGHT SNOW SHOWERS
AND OR PATCHY LIGHT FREEZING DRIZZLE THROUGH THE EARLY MORNING
HOURS. THEN MAINLY DRY CONDITIONS WILL PREVAIL THROUGHOUT THE DAY
WITH SEASONABLE TEMPERATURES. TEMPERATURES WILL BECOME ABOVE NORMAL
TOWARDS THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF MIDNIGHT...KENX RADAR WAS PICKING UP SOME LIGHT RETURNS
HEADING INTO THE CAPITAL REGION. HAD ONE REPORT OFF FACEBOOK OF
LIGHT SNOW CHANGING TO LIGHT FREEZING DRIZZLE BUT THEN BACK TO LIGHT
SNOW TO THE WEST OF THE HUDSON VALLEY.
THE ATMOSPHERE WAS SATURATING UP AS EXPECTED EARLIER.
NOT SURE IT WOULD JUST BE PATCHY FREEZING DRIZZLE THAT WOULD FALL
WITH THE RETURNS. CLOUD DECKS ARE ELEVATED AND ACCORDING TO OUR
SOUNDING...COULD SUPPORT LIGHT SNOW OR FREEZING DRIZZLE.
FOR THIS UPDATE...JUST ASSIGNED A 20 POP TO ALL OF THE
REGION...WHILE KEEP 30 POPS WEST OF THE HUDSON VALLEY. ALSO...ADDED
LIGHT SNOW SHOWERS TO ALL AREAS (ALONG WITH THE PATCHY LIGHT
FREEZING DRIZZLE). HOWEVER...MANY AREAS WILL LIKELY REMAIN DRY WITH
NO PRECIPITATION. IT WILL BE A HIT A MISS SCENARIO.
NO REAL CHANGES TO OVERNIGHT TEMPS. WITH THE CLOUDS...THEY SHOULD BE
PRETTY CLOSE TO AROUND 30 FOR AN OVERNIGHT LOW REGION WIDE (A LITTLE
COLDER IN THE MOUNTAINS).
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
THE LATEST HRRR DID INDICATE THE BEST CHANCES OF LIGHT PRECIPITATION
IN THE CAPITAL REGION WOULD BE UNFORTUNATELY AROUND THE MORNING
DRIVE. WHILE NOT TOTALLY BUYING INTO THIS IDEA...WE DID CONTINUE
SLIGHT CHANCES FOR PATCHY LIGHT FREEZING DRIZZLE AND OR LIGHT SNOW
SHOWER INTO THE MORNING HOURS. AFTER THAT TIME...THE WEAK SYSTEM
SHOULD MOVE ON BUY. CLOUDS COULD THIN ENOUGH FOR A BREAK OR TWO OF
SUNSHINE.
OUR REGION WILL REMAIN BETWEEN SYSTEMS. CLOUDS WILL DOMINATE INTO
TUESDAY. TEMPERATURES ARE EXPECTED TO CONTINUED TO BE SEASONABLE.
THE LONGWAVE TROUGH OVER THE REGION WILL DEEPEN BECOMING NEGATIVELY
TILTED OFF NEW ENGLAND COAST TUESDAY. THE MODEL GUIDANCE IS IN MUCH
BETTER AGREEMENT AND DEVELOP A LOW OFF THE SOUTHEAST COAST MONDAY
THEN TRACK IN NORTHEASTWARD AND KEEPING IT WELL OFFSHORE. IT IS
EXPECTED TO REACH NOVA SCOTIA TUESDAY NIGHT. SOME RIDGING WILL
BUILD IN AT ALL LEVELS TUESDAY NIGHT AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STORM SYSTEM WILL BE MOVING FROM THE GREAT LAKES ON WEDNESDAY
EVENING TOWARDS JAMES BAY FOR THURSDAY.
THIS STORM/S WARM FRONT LOOKS TO MOVE ACROSS OUR REGION ON WED
NIGHT...WITH STRONG WARM AIR ADVECTION TAKING PLACE. 850 HPA TEMPS
WILL SURGE AS HIGH AS +9 ACROSS OUR REGION BY THURSDAY MORNING.
ALTHOUGH MOISTURE WILL BE LIMITED...SOME LIGHT PRECIPITATION IS
EXPECTED OVERNIGHT...ESP FOR THE NORTHERN AND WESTERN PARTS OF THE
AREA. WITH THE WARMING TEMPS ALOFT...PRECIP WILL EITHER BE RAIN OR
FREEZING RAIN...WITH PTYPE DEPENDENT ON SURFACE TEMPS. MOST AREAS
LOOK TO HAVE LOW TEMPS IN THE UPPER 20S TO MID 30S IN THE EVENING
JUST BEFORE OR AT THE START OF WHEN PRECIP BEGINS...WITH TEMPS
RAPIDLY WARMING OVERNIGHT THROUGH THE 30S AND EVEN INTO THE 40S FOR
SOME AREAS. SOME SHELTERED ELEVATED VALLEYS OF THE ADIRONDACKS MAY
HANG ON TO THE SUB FREEZING AIR THE LONGEST...AND THIS IS WHERE THE
BEST THREAT FOR ANY FREEZING RAIN WILL BE. MOST LARGER
VALLEYS...SUCH AS THE HUDSON VALLEY...SHOULD ONLY SEE LIQUID
PRECIP...AS TEMPS LOOK TO BE ABOVE FREEZING DURING THE TIME OF
PRECIP. THE STORM/S COLD FRONT MAY ALLOW FOR SOME ADDITIONAL RAIN
SHOWERS DURING THE DAY ON THURSDAY...ALTHOUGH PRECIP WILL LIKELY BE
RATHER SPOTTY...AS THE BEST FORCING WILL BE WELL NORTHWEST OF THE
AREA AND THERE WON/T BE A GOOD DEAL OF MOISTURE PRESENT. MAX TEMPS
WILL BE ABOVE NORMAL...WITH 40S TO LOW 50S ACROSS THE AREA AHEAD OF
THE BOUNDARY.
BEHIND THIS FRONT...COLDER AIR WILL BEGIN TO MOVE TOWARDS THE REGION
ON FRIDAY. ALTHOUGH THE CORE OF THE COLD AIR WILL REMAIN OVER THE
NORTHERN PLAINS INITIALLY...TEMPS WILL TURN PROGRESSIVELY COLDER
THROUGH THE UPCOMING WEEKEND...WITH TEMPS NEAR OR SLIGHTLY BELOW
NORMAL BY SUNDAY. THE COLD FRONT THAT MOVED THROUGH THE REGION ON
THURSDAY WILL STALL SOUTH OF THE AREA ACROSS THE MID ATLANTIC STATES
FOR LATE IN THE WEEK. WAVES OF LOW PRESSURE MAY DEVELOP ALONG THIS
BOUNDARY AND RIDE NORTHEASTWARD ALONG IT. IF THIS FRONT REMAINS
CLOSE ENOUGH TO OUR AREA...SOME RAIN OR SNOW MAY BE POSSIBLE...ESP
FOR THE SOUTHERN HALF OF THE AREA. THE MODELS ARE UNCLEAR EXACTLY
WHERE OR IF THIS FRONT WILL STALL...AND JUST HOW COLD IT WILL BE
OVER OUR AREA. FOR NOW...WILL GO WITH CHC POPS FOR THURSDAY NIGHT
THROUGH FRIDAY NIGHT...WITH SLIGHT CHC/LOW CHC POPS FOR SAT...WITH
PRECIP RAIN OR SNOW...AND PTYPE BASED ON ELEVATION/DIURNAL TEMP
TRENDS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
WITH THE APPROACH OF AN UPPER LEVEL DISTURBANCE...THERE WILL BE
PLENTY OF CLOUDS TONIGHT. BKN-OVC CIGS OF 8-10 KFT WILL LOWER TO
AROUND 6 KFT BY AROUND MIDNIGHT OR SO. THERE MAY BE A PERIOD OF MVFR
CIGS FOR LATE TONIGHT INTO MONDAY MORNING...BUT IFR CONDITIONS ARE
NOT ANTICIPATED. BKN-OVC CLOUDS WILL CONTINUE INTO THE DAY ON MONDAY.
IT LOOKS TO REMAIN DRY AS WELL...ALTHOUGH A BRIEF SNOW SHOWER IN
THE VICINITY OF KGFL CANNOT BE RULED OUT OVER THE NEXT FEW HOURS.
OTHERWISE...NO PRECIP IS EXPECTED DUE TO LIMITED MOISTURE AND WEAK
FORCING.
WINDS WILL BE CALM OVERNIGHT...AND BECOME LIGHT OUT OF THE S-SE ON
MONDAY...GENERALLY AT LESS THAN 5 KTS.
OUTLOOK...
MON NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX.
WED NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA. CHC FZRA
MAINLY ACROSS THE HIGHER TERRAIN.
THU: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED OVER THE NEXT FEW DAYS.
ANY PRECIPITATION WILL BE LIGHT.
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...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/HWJIV
NEAR TERM...FRUGIS/HWJIV
SHORT TERM...IAA/HWJIV
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
840 PM EST TUE DEC 3 2013
.UPDATE...
HAVE MADE ADJUSTMENTS TO POP GRIDS THROUGH THE EVENING TO ACCOUNT
FOR REDEVELOPMENT OF RAIN ACROSS CENTRAL AND PARTS OF NORTH GA. LOW
LEVEL MOISTURE ADVECTION CONTINUES ACROSS THE REGION AND DEWPOINTS
ARE WELL INTO THE 50S TO LOWER 60S ACROSS CENTRAL AND PARTS OF NORTH
GA AND IN THE UPPER 40S AND 50S ACROSS THE REST OF NORTH GA. WITH
MOISTURE CONTINUING TO ADVECT...IT APPEARS TEMPS WILL REMAIN NEARLY
STEADY FOR THE REST OF THE NIGHT ACROSS THE CWA AND HAVE MADE THE
NECESSARY CHANGES TO TONIGHTS MIN TEMPS. RAIN SHOULD END FROM THE
WEST AFTER MIDNIGHT. SOME PATCHY DENSE FOG IS POSSIBLE AFTER
MIDNIGHT BUT AT THIS TIME WILL NOT ISSUE A DENSE FOG ADVISORY
HOWEVER WILL CONTINUE TO MONITOR THE SITUATION.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
/ISSUED AT 253 PM EST TUE DEC 3 2013/
WARM FRONT SHOULD BE MOVING NORTH THROUGH THE CWA THIS EVENING AND
OVERNIGHT. GFS/NAM KEEP ENHANCED MOISTURE ACROSS THE CWA THROUGH
WEDNESDAY MORNING...AND HRRR IS INDICATING AN EXPANSION OF THE RAIN
AREA AS IT MOVES NORTHEAST TONIGHT. HAVE KEPT LIKELY POPS OVER MUCH
OF THE CENTRAL TO NE ZONES WITH A GRADUAL DECREASE AFTER 06Z. SOME
LINGERING LOW POPS WEDNESDAY MORNING MAINLY NORTH. WEAK UPPER RIDGE
BUILDS OVER THE CWA WEDNESDAY AFTERNOON AND SO HAVE REMOVED THE POPS
FOR THAT TIME. STRONG SOUTHERLY FLOW WILL BRING ANOTHER INCREASE IN
MOISTURE TO THE CWA LATE WEDNESDAY NIGHT AHEAD OF AN APPROACHING
COLD FRONT. HAVE INTRODUCED POPS AGAIN TOWARD THURSDAY MORNING. AIR
MASS LOOKS STABLE FOR THE SHORT TERM...SO HAVE NO MENTION OF
THUNDER. INSTABILITY STARTS TO INCREASE BY 12Z THURSDAY. EXPECT WARM
TEMPERATURES WITH THE STRONG SOUTHERLY FLOW. OVERNIGHT MINS MAY
APPROACH RECORD VALUES.
41
.LONG TERM /THURSDAY THROUGH TUESDAY/...
/ISSUED AT 253 PM EST TUE DEC 3 2013/
ONLY MINOR CHANGES MADE TO THE EXTENDED WITH THIS PACKAGE. REFINED
TIMING OF POPS FOR EARLY THURSDAY AND MADE SOME MINOR ADJUSTMENTS
MAINLY TO LOW TEMPS THROUGH THE EXTENDED. GUIDANCE COMING INTO
SLIGHTLY BETTER AGREEMENT FOR THE FINAL FROPA AFTER THE WEEKEND
CAD EVENT /GFS COMING MUCH BETTER IN LINE WITH THE ECMWF/ SO MADE
SOME ADDITIONAL ADJUSTMENTS TO TEMPS EARLY NEXT WEEK...BUT OVERALL
VERY LITTLE CHANGE. STILL SOME CONCERN ABOUT THUNDERSTORMS
THURSDAY AND FRIDAY AFTERNOON...WITH INCREASING CONCERN FOR
ISOLATED SEVERE. SHERB VALUES HOVER JUST BELOW THE CRITICAL
THRESHOLD OF 1 FOR HIGH SHEAR LOW CAPE SEVERE WEATHER BOTH
AFTERNOONS AND SPC HAS ADDED A GENERAL THUNDER AREA FOR DAY 3
/THURSDAY/. WILL CONTINUE TO MONITOR EVOLUTION OF THE FORECAST.
TDP
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED AT 405 AM EST TUE DEC 3 2013/
AN UNSETTLED WEATHER PATTERN WILL PREDOMINATE FOR MUCH OF THE
EXTENDED PERIOD.
CHANCES FOR LIGHT RAIN WEDNESDAY NIGHT INCREASING OVER MAINLY N GA
AS AN INCREASINGLY WARM AND MOIST SOUTHERLY LOW LEVEL FLOW
CONTINUES AHEAD OF A SLOW MOVING COLD FRONT MOVING ACROSS THE MID
U.S.
THE GFS AND EUROPEAN ARE SIMILAR WITH BRINGING THE FRONT TO THE TN
VALLEY LATE THURSDAY WITH SHOWERS LIKELY FOR N AND PORTIONS OF
CENTRAL GA WITH SMALL CHANCES FOR THUNDERSTORMS. MUCAPE FORECAST IN
THE 200-600 RANGE. FOR THE MOST PART PRECIP EXPECTED TO BE LIGHT AND
POSSIBLY BRIEFLY MODERATE.
FRONT EXPECTED TO MOVE INTO N GA FRIDAY AND TO CENTRAL TO S GA LATE
SATURDAY. MAINLY SMALL THUNDERSTORM CHANCES ASSOCIATED AS AN AXIS OF
MUCAPE MOVES WITH THE FRONT INTO FRIDAY NIGHT BEFORE WEAKENING.
HIGHEST POPS EXPECTED TO BE OVER N GA FRIDAY/FRIDAY NIGHT. SATURDAY
POPS FOR CENTRAL GA MAY NOT BE HIGH ENOUGH WITH CHANCE SHOWERS
FORECAST.
THE TREND FOR MUCH WARMER TEMPERATURES WILL CONTINUE UNTIL THE FRONT
PASSES BY. EXPECTING NEAR-RECORD OR RECORD WARM MIN TEMPS FOR
FRIDAY MORNING.
WITH HIGH PRESSURE MOVING ACROSS THE NORTHERN STATES SATURDAY NIGHT
AND SUNDAY...GFS AND EUROPEAN ARE SIMILAR WITH FORECASTING A COLD
AIR DAMMING EVENT THAT WILL INCREASE RAIN CHANCES ACROSS N AND
PORTIONS OF CENTRAL GA. BY LATE DAY SUNDAY THE GFS AND EUROPEAN
BEGIN TO DIFFER THAT BECOMES EVEN GREATER THROUGH MONDAY. THE GFS
MOVES ANOTHER FRONT ACROSS THE AREA MONDAY DRYING THINGS OUT BY DAYS
END. THE EUROPEAN IS MUCH SLOWER WITH THE FRONT OVER NW GA AT DAYS
END MONDAY MAKING THE FORECAST HIGH UNCERTAIN.
BDL
&&
.AVIATION...
00Z UPDATE...
IFR CIGS SHOULD CONTINUE THROUGH TONIGHT AND EARLY WED MORNING.
THERE COULD BE A BRIEF RISE TO MVFR EARLY THIS EVENING BUT IT WILL
FILL BACK IN. VFR CONDITIONS IN CSG WILL ALSO DROP TO IFR THIS
EVENING. ISOLATED TSRA WEST OF CSG COULD AFFECT THE CSG AREA AND
WILL ADD TEMPO TSRA THERE. ELSEWHERE WILL CONTINUE WITH RAIN AND
DRIZZLE THIS EVENING...WITH FOG LATER TONIGHT. THERE IS A
POSSIBILITY OF DENSE FOG FORMING IF WE LOSE THE UPPER CLOUD DECK AND
FOR THIS REASON HAVE ADDED A TEMPO 1/2SM FG AROUND 08Z THROUGH 12Z.
WINDS WILL BE NEAR CALM TONIGHT...THEN SOUTHEAST...BECOMING
SOUTHWEST BY 18Z ALL AREAS. SPEEDS WILL REMAIN BELOW 10 KTS.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM ON ALL ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 52 68 57 72 / 70 20 20 40
ATLANTA 55 69 62 72 / 60 20 20 50
BLAIRSVILLE 49 63 57 67 / 50 20 30 60
CARTERSVILLE 52 68 60 72 / 50 20 30 50
COLUMBUS 57 75 65 76 / 60 10 20 40
GAINESVILLE 50 65 59 69 / 60 20 30 50
MACON 55 74 61 75 / 70 10 20 30
ROME 53 69 61 73 / 50 20 40 60
PEACHTREE CITY 51 70 60 73 / 70 10 20 50
VIDALIA 57 76 59 76 / 40 10 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...41
LONG TERM....TDP
AVIATION...41
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
628 PM EST TUE DEC 3 2013
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
/ISSUED AT 253 PM EST TUE DEC 3 2013/
WARM FRONT SHOULD BE MOVING NORTH THROUGH THE CWA THIS EVENING AND
OVERNIGHT. GFS/NAM KEEP ENHANCED MOISTURE ACROSS THE CWA THROUGH
WEDNESDAY MORNING...AND HRRR IS INDICATING AN EXPANSION OF THE RAIN
AREA AS IT MOVES NORTHEAST TONIGHT. HAVE KEPT LIKELY POPS OVER MUCH
OF THE CENTRAL TO NE ZONES WITH A GRADUAL DECREASE AFTER 06Z. SOME
LINGERING LOW POPS WEDNESDAY MORNING MAINLY NORTH. WEAK UPPER RIDGE
BUILDS OVER THE CWA WEDNESDAY AFTERNOON AND SO HAVE REMOVED THE POPS
FOR THAT TIME. STRONG SOUTHERLY FLOW WILL BRING ANOTHER INCREASE IN
MOISTURE TO THE CWA LATE WEDNESDAY NIGHT AHEAD OF AN APPROACHING
COLD FRONT. HAVE INTRODUCED POPS AGAIN TOWARD THURSDAY MORNING. AIR
MASS LOOKS STABLE FOR THE SHORT TERM...SO HAVE NO MENTION OF
THUNDER. INSTABILITY STARTS TO INCREASE BY 12Z THURSDAY. EXPECT WARM
TEMPERATURES WITH THE STRONG SOUTHERLY FLOW. OVERNIGHT MINS MAY
APPROACH RECORD VALUES.
41
.LONG TERM /THURSDAY THROUGH TUESDAY/...
/ISSUED AT 253 PM EST TUE DEC 3 2013/
ONLY MINOR CHANGES MADE TO THE EXTENDED WITH THIS PACKAGE. REFINED
TIMING OF POPS FOR EARLY THURSDAY AND MADE SOME MINOR ADJUSTMENTS
MAINLY TO LOW TEMPS THROUGH THE EXTENDED. GUIDANCE COMING INTO
SLIGHTLY BETTER AGREEMENT FOR THE FINAL FROPA AFTER THE WEEKEND
CAD EVENT /GFS COMING MUCH BETTER IN LINE WITH THE ECMWF/ SO MADE
SOME ADDITIONAL ADJUSTMENTS TO TEMPS EARLY NEXT WEEK...BUT OVERALL
VERY LITTLE CHANGE. STILL SOME CONCERN ABOUT THUNDERSTORMS
THURSDAY AND FRIDAY AFTERNOON...WITH INCREASING CONCERN FOR
ISOLATED SEVERE. SHERB VALUES HOVER JUST BELOW THE CRITICAL
THRESHOLD OF 1 FOR HIGH SHEAR LOW CAPE SEVERE WEATHER BOTH
AFTERNOONS AND SPC HAS ADDED A GENERAL THUNDER AREA FOR DAY 3
/THURSDAY/. WILL CONTINUE TO MONITOR EVOLUTION OF THE FORECAST.
TDP
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED AT 405 AM EST TUE DEC 3 2013/
AN UNSETTLED WEATHER PATTERN WILL PREDOMINATE FOR MUCH OF THE
EXTENDED PERIOD.
CHANCES FOR LIGHT RAIN WEDNESDAY NIGHT INCREASING OVER MAINLY N GA
AS AN INCREASINGLY WARM AND MOIST SOUTHERLY LOW LEVEL FLOW
CONTINUES AHEAD OF A SLOW MOVING COLD FRONT MOVING ACROSS THE MID
U.S.
THE GFS AND EUROPEAN ARE SIMILAR WITH BRINGING THE FRONT TO THE TN
VALLEY LATE THURSDAY WITH SHOWERS LIKELY FOR N AND PORTIONS OF
CENTRAL GA WITH SMALL CHANCES FOR THUNDERSTORMS. MUCAPE FORECAST IN
THE 200-600 RANGE. FOR THE MOST PART PRECIP EXPECTED TO BE LIGHT AND
POSSIBLY BRIEFLY MODERATE.
FRONT EXPECTED TO MOVE INTO N GA FRIDAY AND TO CENTRAL TO S GA LATE
SATURDAY. MAINLY SMALL THUNDERSTORM CHANCES ASSOCIATED AS AN AXIS OF
MUCAPE MOVES WITH THE FRONT INTO FRIDAY NIGHT BEFORE WEAKENING.
HIGHEST POPS EXPECTED TO BE OVER N GA FRIDAY/FRIDAY NIGHT. SATURDAY
POPS FOR CENTRAL GA MAY NOT BE HIGH ENOUGH WITH CHANCE SHOWERS
FORECAST.
THE TREND FOR MUCH WARMER TEMPERATURES WILL CONTINUE UNTIL THE FRONT
PASSES BY. EXPECTING NEAR-RECORD OR RECORD WARM MIN TEMPS FOR
FRIDAY MORNING.
WITH HIGH PRESSURE MOVING ACROSS THE NORTHERN STATES SATURDAY NIGHT
AND SUNDAY...GFS AND EUROPEAN ARE SIMILAR WITH FORECASTING A COLD
AIR DAMMING EVENT THAT WILL INCREASE RAIN CHANCES ACROSS N AND
PORTIONS OF CENTRAL GA. BY LATE DAY SUNDAY THE GFS AND EUROPEAN
BEGIN TO DIFFER THAT BECOMES EVEN GREATER THROUGH MONDAY. THE GFS
MOVES ANOTHER FRONT ACROSS THE AREA MONDAY DRYING THINGS OUT BY DAYS
END. THE EUROPEAN IS MUCH SLOWER WITH THE FRONT OVER NW GA AT DAYS
END MONDAY MAKING THE FORECAST HIGH UNCERTAIN.
BDL
&&
.AVIATION...
00Z UPDATE...
IFR CIGS SHOULD CONTINUE THROUGH TONIGHT AND EARLY WED MORNING.
THERE COULD BE A BRIEF RISE TO MVFR EARLY THIS EVENING BUT IT WILL
FILL BACK IN. VFR CONDITIONS IN CSG WILL ALSO DROP TO IFR THIS
EVENING. ISOLATED TSRA WEST OF CSG COULD AFFECT THE CSG AREA AND
WILL ADD TEMPO TSRA THERE. ELSEWHERE WILL CONTINUE WITH RAIN AND
DRIZZLE THIS EVENING...WITH FOG LATER TONIGHT. THERE IS A
POSSIBILITY OF DENSE FOG FORMING IF WE LOSE THE UPPER CLOUD DECK AND
FOR THIS REASON HAVE ADDED A TEMPO 1/2SM FG AROUND 08Z THROUGH 12Z.
WINDS WILL BE NEAR CALM TONIGHT...THEN SOUTHEAST...BECOMING
SOUTHWEST BY 18Z ALL AREAS. SPEEDS WILL REMAIN BELOW 10 KTS.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM ON ALL ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 52 68 57 72 / 70 20 20 40
ATLANTA 55 69 62 72 / 60 20 20 50
BLAIRSVILLE 49 63 57 67 / 50 20 30 60
CARTERSVILLE 52 68 60 72 / 50 20 30 50
COLUMBUS 57 75 65 76 / 60 10 20 40
GAINESVILLE 50 65 59 69 / 60 20 30 50
MACON 55 74 61 75 / 70 10 20 30
ROME 53 69 61 73 / 50 20 40 60
PEACHTREE CITY 51 70 60 73 / 70 10 20 50
VIDALIA 57 76 59 76 / 40 10 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...41
LONG TERM....TDP
AVIATION...41
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
645 AM EST MON DEC 2 2013
.SYNOPSIS...
HIGH PRESSURE EXTENDING FROM THE MID-ATLANTIC STATES TO THE GULF
COAST STATES WILL WEAKEN ACROSS THE CAROLINAS TODAY AS WEAK LOW
PRESSURE DEVELOPS OFF THE COAST. THE AREA OF LOW PRESSURE WILL
MOVE NORTHWARD TONIGHT...ALLOWING HIGH PRESSURE TO SLIDE EAST AND
MOVE OFF SHORE TUESDAY. A WARMING TREND IS EXPECTED FOR MID-WEEK
WITH A COLD FRONT APPROACHING FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHORT WAVE TROUGH MOVING ACROSS THE AREA TODAY WILL INDUCE
CYCLOGENESIS OFFSHORE. THE LOW PRESSURE AREA WILL TRACK NORTHEAST.
FORCING AND STRONG LIFT WILL REMAIN TO THE NORTHEAST OF THE REGION
TODAY. WEST COMPONENT TO LOW LEVEL FLOW WILL LIMIT MOISTURE
ADVECTION...PRECIPITABLE WATER REMAINS LOW. RADAR SHOWING SHOWERS
MOVING EAST ACROSS CENTRAL GEORGIA. RAP MODEL SUGGESTS SHOWERS
WILL REMAIN WEST OF THE AREA HOWEVER LATEST HRRR SUGGESTS A FEW
SHOWERS IN THE CSRA THIS MORNING. BASED ON RADAR TRENDS WILL PUT
SLIGHT CHANCE SHOWERS NEAR AGS THIS MORNING. DESPITE CONSIDERABLE CLOUDS
AT TIMES...ESPECIALLY THIS MORNING...EXPECT TEMPERATURES TO BE A
DEGREE OR TWO WARMER THAN YESTERDAY DUE TO DOWNSLOPE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UPPER FLOW ON TUESDAY BECOMES MORE ZONAL FROM THE WEST ACROSS THE
AREA WITH RISING 500MB HEIGHTS. A DIGGING TROUGH ACROSS THE WEST
WILL BEGIN TO INDUCE DOWNSTREAM RIDGING AND DEVELOPING WARM
ADVECTION ACROSS THE GULF COAST STATES INTO THE TENNESSEE VALLEY.
A WARM FRONT WILL DEVELOP WEST OF THE AREA AND MODELS ARE SHOWING
SOME ISENTROPIC LIFT ASSOCIATED WITH THE WARM ADVECTION WHILE THE
NAM ACTUALLY SHOWS SOME PRECIPITATION. MOISTURE IS QUITE LIMITED
WITH PRECIPITABLE WATER VALUES BETWEEN A HALF INCH AND 0.75 INCHES
SO THINK MEASURABLE PRECIPITATION IS LOW BUT WILL INCLUDE SLIGHT
CHANCE POPS IN THE WESTERN MIDLANDS AND CSRA TUESDAY EVENING.
GIVEN WARM ADVECTION PATTERN EXPECT TEMPERATURES TUESDAY AND
WEDNESDAY TO BE ABOVE NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LITTLE CHANGE IN THE EXTENDED FORECAST THINKING. CONTINUED RUN TO
RUN INCONSISTENCIES AMONG THE OPERATIONAL MEDIUM RANGE GUIDANCE AND
ABOVE AVERAGE MODEL SPREAD DURING THIS PERIOD LEADS TO LOWER THAN
AVERAGE CONFIDENCE...ESPECIALLY FRI-SUN. THE MAIN FORECAST PROBLEM
REVOLVES AROUND THE TIMING OF A COLD FRONT FRI-SAT PERIOD.
THERE IS GENERAL AGREEMENT IN A LARGE AND EXPANSIVE UPPER TROUGH
ACROSS THE WESTERN UNITED STATES WITH DOWNSTREAM RIDGING ACROSS THE
SOUTHEASTERN STATES INTO THE MID ATLANTIC REGION. A SLOW MOVING
FRONTAL BOUNDARY WILL PUSH INTO THE OHIO AND TENNESSEE VALLEYS ON
WEDNESDAY BEFORE STALLING JUST WEST OF THE FORECAST AREA THURSDAY
INTO FRIDAY AS THE DEEP SOUTHWESTERLY FLOW ALOFT BECOMES NEARLY
PERPENDICULAR TO THE ORIENTATION OF THE FRONT.
SURFACE HIGH PRESSURE CENTERED JUST OFF THE CAROLINA COAST ON
WEDNESDAY WILL GRADUALLY SHIFT FURTHER OFFSHORE AND ALLOW A MOIST
SOUTHERLY FLOW TO RETURN OVER THE FORECAST AREA THROUGH THE END OF
THE WEEK. PRECIPITABLE WATER VALUES SURGE TO BETWEEN 1.5 AND 1.75
INCHES THURSDAY AND MAINTAIN THAT THROUGH THE WEEKEND. THE BEST
CHANCES OF RAIN FIGURE TO REMAIN JUST WEST OF THE FORECAST AREA
WED-THU WITH INCREASING CHANCES OF RAIN FRIDAY INTO THE WEEKEND AS
THE COLD FRONT EVENTUALLY PUSHES INTO THE FORECAST AREA AT SOME
POINT. PLENTY OF UNCERTAINTY REMAINS REGARDING THE TIMING OF A
FRONTAL PASSAGE AND ASSOCIATED PRECIPITATION AND EVEN POSSIBLE
THUNDERSTORMS WITH CONSIDERABLE SPREAD IN THE GUIDANCE.
WILL PLAN TO CARRY A FAIRLY PERSISTENT FORECAST AND KEEP THE POPS
THAT WERE INHERITED FROM PREVIOUS FORECAST AT THIS POINT WHILE
ADDING A NEW DAY 7 WITH CHANCE POPS WITH THE POTENTIAL FRONT
LINGERING IN THE AREA. REASONABLE HIGH CONFIDENCE IN SIGNIFICANT
WARM UP NEXT WEEK UNDER THE INFLUENCE OF THE UPPER RIDGE AND
SOUTHERLY FLOW SO HAVE INCREASED MAX/MIN TEMPS SEVERAL DEGREES TO
BETTER FIT WITHIN THE SPECTRUM OF THE MODEL GUIDANCE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE GULF STATES WITH
MORE PRECIPITATION THAN ORIGINALLY ANTICIPATED. DRY AIR REMAINS
ACROSS THE TAF SITES...HOWEVER EXPECT SOME SHOWERS TO MOVE THROUGH
THE AREA THIS MORNING INTO EARLY THIS AFTERNOON. CONFIDENCE IN
RAIN REMAINS LOW SO HAVE INCLUDED VCSH AT ALL TAF SITES WITH CIGS
ANTICIPATED VFR. UPPER LEVEL TROUGH WILL MOVE OFFSHORE LATE THIS
AFTERNOON WITH CLOUDINESS LINGERING THROUGH THE END OF THE PERIOD
WITH CIGS REMAINING VFR.
EXTENDED AVIATION OUTLOOK...LOW CONFIDENCE FORECAST FOR THE
EXTENDED OUTLOOK WITH PERIODS OF MVFR...POSSIBLY
LOWER...CONDITIONS TUESDAY THROUGH FRIDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
518 AM EST MON DEC 2 2013
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE CAROLINA COAST THIS MORNING
AND LIFT NORTHEAST TODAY...WHILE GENERALLY DRY HIGH PRESSURE PREVAILS
OVER THE AREA THROUGH LATE WEEK. A COLD FRONT SHOULD THEN SHIFT OVER
THE AREA DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...SATELLITE IMAGERY THIS MORNING PORTRAYS A TEXTBOOK BAROCLINIC
LEAF SIGNATURE OVER THE SE UNITED STATES AS WEAK CYCLOGENESIS IS
UNDERWAY ALONG THE WEST WALL OF THE GULF STREAM. UNDER THE LEAF OF
THICK MID AND HIGH CLOUDS...SURFACE CONDITIONS WERE RAIN-FREE ACROSS
CENTRAL GEORGIA AS PCPN FALLS INTO A VERY DRY LAYER BETWEEN 5-16 KFT.
LIGHT RADAR RETURNS MAINLY VIRGA AT THIS POINT WITH OTHER RAINS
BREAKING OUT IN NW GEORGIA AND EASTERN ALABAMA AS MODELS INDICATED.
UPPER FORCING/PVA COULD RESULT IN SOME SPRINKLES OR SPOTTY LIGHT
SHOWERS AT SOME LOCATIONS THROUGH MID MORNING. AT THIS POINT...
MEASURABLE RAINFALL CHANCES LOOK QUITE SMALL AND OUR POPS SILENT.
TEMPS MILD 50-53...FALLING INTO THE 40S LATE. LOCALIZED BUILD-DOWN
STRATUS HAD DEVELOPED OVER CHARLESTON COUNTY...UPDATED TO ADD
MENTION OF PATCHY FOG EARLY THIS MORNING.
THE PROGRESSIVE UPPER WAVE WILL SWEEP OFF THE COAST BY MIDDAY WITH
CLOUDS QUICKLY CLEARING OUT FOR THE AFTERNOON ACROSS THE FORECAST
AREA. FORECAST VERTICAL MOISTURE PROFILES DRY OUT FAST AND MODEL
CLOUD FORECAST PROGS SUCH AS THE REGIONAL GEM INDICATE SUNSHINE
SHOULD BE PREVALENT DURING THE AFTERNOON HOURS. IN THE WAKE OF
THE OFFSHORE LOW PRES...LOW LEVEL WINDS WILL BECOME W TO WNW AND
THIS WILL ALLOW FOR A LOWER RISK FOR MANY LINGERING LOWER CLOUDS BY
EARLY AFTERNOON. LACK OF SIGNIFICANT COLD AIR ADVECTION AND THE WEAK
DOWNSLOPE COMPONENT SHOULD ALLOW HIGH TEMPS TO REACH THE MID 60S
MOST AREAS PROVIDED THE CLOUDS SCATTER OUT EARLIER OR ON TIME...
RATHER THAN LATER. INCREASING LAYERED CLOUDS EXPECTED TONIGHT WITH
LOWS IN THE 40S AND WITH JUST SPRINKLE CHANCES...POPS SILENT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
QUIET/DRY WEATHER IS EXPECTED THROUGH MIDWEEK AS WEAK HIGH PRESSURE
SETTLES OVER THE AREA BEHIND A DEPARTING SFC LOW WELL TO OUR
NORTHEAST. MODELS CONTINUE TO INDICATE A FAIRLY SIGNIFICANT WARMING
TREND THROUGH THROUGH THURSDAY AS SOUTHERLY FLOW DEVELOPS ALONG THE
WESTERN EDGE OF SFC HIGH PRESSURE WHILE SLIGHT MID LVL RIDGING
OCCURS FROM THE SOUTH/SOUTHWEST. HOWEVER...PEAK HEATING MAY BE
LIMITED A FEW DEGREES EACH DAY DUE TO CIRRUS THAT DEVELOPS WITH A
STRONG H25 JET POSITIONED JUST TO THE NORTHWEST OR MID CLOUDS
ASSOCIATED WITH MODEST ISENTROPIC OVER THE AREA. DESPITE CLOUD
COVER...PERSISTENT SOUTHERLY FLOW WILL LIKELY WARM OVERALL HIGH
TEMPS INTO THE UPPER 60S TO AROUND 70 ON TUESDAY...THEN LOW 70S ON
WEDNESDAY...FOLLOWED BY MID/UPPER 70S BY THURSDAY. OVERNIGHT LOWS
WILL ALSO REMAIN MILD EACH NIGHT...IN THE LOW/MID 50S INLAND TO
UPPER 50S/LOWER 60S ALONG THE IMMEDIATE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
CONDITIONS WILL REMAIN QUIET/DRY THROUGH FRIDAY AS THE AREA REMAINS
SITUATED ALONG THE WESTERN EDGE OF SFC HIGH PRESSURE. PERSISTENT
SOUTHERLY FLOW ALONG WITH MID LVL RIDGING FROM THE SOUTH/SOUTHWEST
WILL LIKELY LEAD TO ABOVE NORMAL TEMPS AHEAD OF A COLD FRONT
APPROACHING FROM THE WEST. IN GENERAL...EXPECT HIGH TEMPS IN THE
UPPER 70S ON FRIDAY WITH OVERNIGHT LOWS IN THE UPPER 50S/LOWER 60S.
PRECIP CHANCES SHOULD THEN INCREASE THIS WEEKEND AS A COLD FRONT
BEGINS SHIFTING THROUGH THE SOUTHEASTERN UNITED STATES. UNCERTAINTY
REMAINS HIGH WITH THE POSITION OF THE FRONT ON SATURDAY AND SUNDAY
BUT THE GENERAL CONSENSUS IS THAT THE FRONT SHOULD STALL JUST SOUTH
OF THE FORECAST AREA BEFORE LIFTING NORTH AS A WARM FRONT AHEAD OF
SFC LOW SHIFTING OVER THE DEEP SOUTH AND THEN THE SOUTHEASTERN UNITED
STATES EARLY NEXT WEEK. HAVE THUS MAINTAINED CHANCE POPS SATURDAY
AND SUNDAY AS MOISTURE REMAINS ALONG/NEAR THE FRONT. A SLIGHT CHANCE
OF SHOWERS WILL ALSO BE POSSIBLE ON MONDAY WHILE CONDITIONS
GRADUALLY IMPROVE WITH THE LOW SHIFTING OFFSHORE. OVERALL HIGH TEMPS
SHOULD PEAK NEAR 70 ON SATURDAY AHEAD OF THE FRONT...THEN COOL OFF
INTO THE LOW 60S ON SUNDAY AND MONDAY AS THE SFC LOW SHIFTS OVER THE
SOUTHEAST AND OFFSHORE.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
KCHS...CIGS IFR AT 06Z AND LATEST RAP SOUNDINGS SUGGEST CIGS MAY
LOWER A BIT MORE BEFORE IMPROVING TOWARD DAYBREAK AS A LIGHT
NW FLOW DEVELOP. UPSTREAM CIGS OVER INLAND AREAS ARE CURRENTLY
VFR WITH MVFR VSBYS. WE IMPROVE CONDITIONS MID MORNING THEN VFR
CONDITIONS BY LATE MORNING THROUGH THIS EVENING.
KSAV...MVFR OR IFR CIGS IN AND OUT UNDER A STRONG INVERSION BUT
CONDITIONS SHOULD IMPROVE BY MID MORNING AND VFR WILL PERSIST FOR
THE REMAINDER OF THE DAY INTO THIS EVENING.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD PREVAIL THROUGH
FRIDAY. MVFR CIGS/VSBYS ARE POSSIBLE SATURDAY AS SHOWERS OCCUR ALONG
A PASSING COLD FRONT.
&&
.MARINE...
A LIGHT NW FLOW IS FORECAST IN THE WAKE OF AN OFFSHORE LOW RACING
TO THE NE TODAY. A WEAK GRADIENT SHOULD ENSURE A LACK OF ANY
SIGNIFICANT SURGES AFTER MID MORNING. SEAS ALSO CONTINUE TO SLOWLY
SUBSIDE. SEAS 3 TO 4 FT COMING DOWN TO 2 TO 3 FT BY TONIGHT.
TUESDAY THROUGH SATURDAY...WINDS/SEAS WILL REMAIN WELL BELOW SMALL
CRAFT ADVISORY LEVELS AS A SFC LOW CONTINUES TO SHIFT NORTHEAST AND
AWAY FROM THE REGION THROUGH TUESDAY. WEAK HIGH PRESSURE WILL THEN
SETTLE OVER THE WATERS THROUGH THURSDAY WITH WINDS/SEAS EXPECTED TO
REMAIN AT OR BELOW 15 KT WITH SEAS NO HIGHER THAN 3 FT. WINDS/SEAS
WILL THEN GRADUALLY INCREASE/BUILD TO 15-20 KT AND 4-5 FT ON FRIDAY
AS THE PRESSURE GRADIENT BEGINS TO ENHANCE BETWEEN HIGH PRESSURE
OVER THE WESTERN ATLANTIC AND A COLD FRONT APPROACHING INLAND.
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
SATURDAY AS THE COLD FRONT STALLS OVER OR JUST SOUTH OF THE WATERS.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE HIGH THROUGH MID-WEEK DUE TO ASTRONOMICAL
INFLUENCES OF THE UPCOMING PERIGEE AND NEW MOON /PERIGEAN SPRING
TIDES/. WE HAVE ISSUED A COASTAL FLOOD ADVISORY FOR CHARLESTON
COUNTY AS THE TIDE LIKELY TO TOUCH 7 FT MLLW GIVEN THE LATEST
DEPARTURES STILL AT 1/2 FOOT ABOVE PREDICTED. COASTAL FLOOD
ADVISORIES MIGHT BE NEEDED TUESDAY MORNING AND AGAIN WEDNESDAY
MORNING WITH THOSE HIGH TIDES AS WELL.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...COASTAL FLOOD ADVISORY UNTIL 8 AM EST THIS MORNING FOR SCZ050.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
427 AM EST MON DEC 2 2013
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE CAROLINA COAST THIS MORNING
AND LIFT NORTHEAST TODAY...WHILE GENERALLY DRY HIGH PRESSURE PREVAILS
OVER THE AREA THROUGH LATE WEEK. A COLD FRONT SHOULD THEN SHIFT OVER
THE AREA DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...SATELLITE IMAGERY THIS MORNING PORTRAYS A TEXTBOOK BAROCLINIC
LEAF SIGNATURE OVER THE SE UNITED STATES AS WEAK CYCLOGENESIS IS
UNDERWAY ALONG THE WEST WALL OF THE GULF STREAM. UNDER THE LEAF OF
THICK MID AND HIGH CLOUDS...SURFACE CONDITIONS WERE RAIN-FREE ACROSS
CENTRAL GEORGIA AS PCPN FALLS INTO A VERY DRY LAYER BETWEEN 5-16 KFT.
LIGHT RADAR RETURNS MAINLY VIRGA AT THIS POINT WITH OTHER RAINS
BREAKING OUT IN NW GEORGIA AND EASTERN ALABAMA AS MODELS INDICATED.
UPPER FORCING/PVA COULD RESULT IN SOME SPRINKLES OR SPOTTY LIGHT
SHOWERS AT SOME LOCATIONS THROUGH MID MORNING. AT THIS POINT...
MEASURABLE RAINFALL CHANCES LOOK QUITE SMALL AND OUR POPS SILENT.
TEMPS MILD 50-53...FALLING INTO THE 40S LATE.
THE PROGRESSIVE UPPER WAVE WILL SWEEP OFF THE COAST BY MIDDAY WITH
CLOUDS QUICKLY CLEARING OUT FOR THE AFTERNOON ACROSS THE FORECAST
AREA. FORECAST VERTICAL MOISTURE PROFILES DRY OUT FAST AND MODEL
CLOUD FORECAST PROGS SUCH AS THE REGIONAL GEM INDICATE SUNSHINE
SHOULD BE PREVALENT DURING THE AFTERNOON HOURS. IN THE WAKE OF
THE OFFSHORE LOW PRES...LOW LEVEL WINDS WILL BECOME W TO WNW AND
THIS WILL ALLOW FOR A LOWER RISK FOR MANY LINGERING LOWER CLOUDS BY
EARLY AFTERNOON. LACK OF SIGNIFICANT COLD AIR ADVECTION AND THE WEAK
DOWNSLOPE COMPONENT SHOULD ALLOW HIGH TEMPS TO REACH THE MID 60S
MOST AREAS PROVIDED THE CLOUDS SCATTER OUT EARLIER OR ON TIME...
RATHER THAN LATER. INCREASING LAYERED CLOUDS EXPECTED TONIGHT WITH
LOWS IN THE 40S AND WITH JUST SPRINKLE CHANCES...POPS SILENT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
QUIET/DRY WEATHER IS EXPECTED THROUGH MIDWEEK AS WEAK HIGH PRESSURE
SETTLES OVER THE AREA BEHIND A DEPARTING SFC LOW WELL TO OUR
NORTHEAST. MODELS CONTINUE TO INDICATE A FAIRLY SIGNIFICANT WARMING
TREND THROUGH THROUGH THURSDAY AS SOUTHERLY FLOW DEVELOPS ALONG THE
WESTERN EDGE OF SFC HIGH PRESSURE WHILE SLIGHT MID LVL RIDGING
OCCURS FROM THE SOUTH/SOUTHWEST. HOWEVER...PEAK HEATING MAY BE
LIMITED A FEW DEGREES EACH DAY DUE TO CIRRUS THAT DEVELOPS WITH A
STRONG H25 JET POSITIONED JUST TO THE NORTHWEST OR MID CLOUDS
ASSOCIATED WITH MODEST ISENTROPIC OVER THE AREA. DESPITE CLOUD
COVER...PERSISTENT SOUTHERLY FLOW WILL LIKELY WARM OVERALL HIGH
TEMPS INTO THE UPPER 60S TO AROUND 70 ON TUESDAY...THEN LOW 70S ON
WEDNESDAY...FOLLOWED BY MID/UPPER 70S BY THURSDAY. OVERNIGHT LOWS
WILL ALSO REMAIN MILD EACH NIGHT...IN THE LOW/MID 50S INLAND TO
UPPER 50S/LOWER 60S ALONG THE IMMEDIATE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
CONDITIONS WILL REMAIN QUIET/DRY THROUGH FRIDAY AS THE AREA REMAINS
SITUATED ALONG THE WESTERN EDGE OF SFC HIGH PRESSURE. PERSISTENT
SOUTHERLY FLOW ALONG WITH MID LVL RIDGING FROM THE SOUTH/SOUTHWEST
WILL LIKELY LEAD TO ABOVE NORMAL TEMPS AHEAD OF A COLD FRONT
APPROACHING FROM THE WEST. IN GENERAL...EXPECT HIGH TEMPS IN THE
UPPER 70S ON FRIDAY WITH OVERNIGHT LOWS IN THE UPPER 50S/LOWER 60S.
PRECIP CHANCES SHOULD THEN INCREASE THIS WEEKEND AS A COLD FRONT
BEGINS SHIFTING THROUGH THE SOUTHEASTERN UNITED STATES. UNCERTAINTY
REMAINS HIGH WITH THE POSITION OF THE FRONT ON SATURDAY AND SUNDAY
BUT THE GENERAL CONSENSUS IS THAT THE FRONT SHOULD STALL JUST SOUTH
OF THE FORECAST AREA BEFORE LIFTING NORTH AS A WARM FRONT AHEAD OF
SFC LOW SHIFTING OVER THE DEEP SOUTH AND THEN THE SOUTHEASTERN UNITED
STATES EARLY NEXT WEEK. HAVE THUS MAINTAINED CHANCE POPS SATURDAY
AND SUNDAY AS MOISTURE REMAINS ALONG/NEAR THE FRONT. A SLIGHT CHANCE
OF SHOWERS WILL ALSO BE POSSIBLE ON MONDAY WHILE CONDITIONS
GRADUALLY IMPROVE WITH THE LOW SHIFTING OFFSHORE. OVERALL HIGH TEMPS
SHOULD PEAK NEAR 70 ON SATURDAY AHEAD OF THE FRONT...THEN COOL OFF
INTO THE LOW 60S ON SUNDAY AND MONDAY AS THE SFC LOW SHIFTS OVER THE
SOUTHEAST AND OFFSHORE.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
KCHS...CIGS IFR AT 06Z AND LATEST RAP SOUNDINGS SUGGEST CIGS MAY
LOWER A BIT MORE BEFORE IMPROVING TOWARD DAYBREAK AS A LIGHT
NW FLOW DEVELOP. UPSTREAM CIGS OVER INLAND AREAS ARE CURRENTLY
VFR WITH MVFR VSBYS. WE IMPROVE CONDITIONS MID MORNING THEN VFR
CONDITIONS BY LATE MORNING THROUGH THIS EVENING.
KSAV...MVFR OR IFR CIGS IN AND OUT UNDER A STRONG INVERSION BUT
CONDITIONS SHOULD IMPROVE BY MID MORNING AND VFR WILL PERSIST FOR
THE REMAINDER OF THE DAY INTO THIS EVENING.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD PREVAIL THROUGH
FRIDAY. MVFR CIGS/VSBYS ARE POSSIBLE SATURDAY AS SHOWERS OCCUR ALONG
A PASSING COLD FRONT.
&&
.MARINE...
A LIGHT NW FLOW IS FORECAST IN THE WAKE OF AN OFFSHORE LOW RACING
TO THE NE TODAY. A WEAK GRADIENT SHOULD ENSURE A LACK OF ANY
SIGNIFICANT SURGES AFTER MID MORNING. SEAS ALSO CONTINUE TO SLOWLY
SUBSIDE. SEAS 3 TO 4 FT COMING DOWN TO 2 TO 3 FT BY TONIGHT.
TUESDAY THROUGH SATURDAY...WINDS/SEAS WILL REMAIN WELL BELOW SMALL
CRAFT ADVISORY LEVELS AS A SFC LOW CONTINUES TO SHIFT NORTHEAST AND
AWAY FROM THE REGION THROUGH TUESDAY. WEAK HIGH PRESSURE WILL THEN
SETTLE OVER THE WATERS THROUGH THURSDAY WITH WINDS/SEAS EXPECTED TO
REMAIN AT OR BELOW 15 KT WITH SEAS NO HIGHER THAN 3 FT. WINDS/SEAS
WILL THEN GRADUALLY INCREASE/BUILD TO 15-20 KT AND 4-5 FT ON FRIDAY
AS THE PRESSURE GRADIENT BEGINS TO ENHANCE BETWEEN HIGH PRESSURE
OVER THE WESTERN ATLANTIC AND A COLD FRONT APPROACHING INLAND.
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
SATURDAY AS THE COLD FRONT STALLS OVER OR JUST SOUTH OF THE WATERS.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE HIGH THROUGH MID-WEEK DUE TO ASTRONOMICAL
INFLUENCES OF THE UPCOMING PERIGEE AND NEW MOON /PERIGEAN SPRING
TIDES/. THE TIDE AROUND 7 AM THIS MORNING IN DOWNTOWN CHARLESTON
WILL BE CLOSE TO 7 FT MLLW BUT WE DECIDED TO HOLD OFF ON A COASTAL
FLOODING ADVISORY AS THE WEAK LOW LEVEL FLOW HAS TURNING OFFSHORE
AND DEPARTURES APPEAR TO ON THEIR WAY DOWN. IT CERTAINLY APPEARS
VERY MARGINAL AT THIS POINT BUT WE WILL BE WATCHING TRENDS THE
NEXT FEW HOURS NEARING HIGH TIDE. COASTAL FLOOD ADVISORIES MIGHT
BE NEEDED TUESDAY MORNING AND AGAIN WEDNESDAY MORNING WITH THOSE
HIGH TIDES AS WELL.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
120 AM EST MON DEC 2 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEAKEN WHILE A COASTAL TROUGH LINGERS
OFFSHORE. AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST
COAST EARLY MONDAY AND LIFT NORTH/NORTHEAST THROUGH MID WEEK...WHILE
GENERALLY DRY HIGH PRESSURE PREVAILS OVER THE AREA THROUGH LATE
WEEK. A COLD FRONT SHOULD THEN SHIFT OVER THE AREA DURING THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE INLAND WEDGE OF HIGH PRESSURE WILL CONTINUE TO ERODE TONIGHT...
WHILE A COASTAL TROUGH LINGERS OFFSHORE. MEANWHILE...A NEARLY
ZONAL FLOW WILL PREVAIL ALOFT THROUGH MOST OF THE NIGHT...UNTIL A
MID LEVEL PERTURBATION IN THE LOWER MISSISSIPPI VALLEY THIS
EVENING PASSES THROUGH LATE TONIGHT AND INDUCES WEAK CYCLOGENESIS
OFF THE SOUTH CAROLINA COAST ALONG THE TROUGH AXIS OUT NEAR THE
GULF STREAM.
MODEL SOUNDINGS INDICATE THAT A SUBSIDENCE INVERSION WILL KEEP
MOISTURE TRAPPED IN THE LOW LEVELS OF THE ATMOSPHERE. WHILE AT
FIRST GLANCE THIS MIGHT LEAD TO SOME FOG FORMATION. BUT GIVEN
EXTENSIVE AND MOSTLY OPAQUE HIGH LEVEL CLOUD COVER WITH A 120-150
KT UPPER JET MOVING THROUGH THE SE AND TENNESSEE VALLEY AND
CONDENSATION PRESSURE DEFICITS NO LOWER THAN ABOUT 30
MILLIBARS...WE HAVE REFRAINED FROM INCLUDING ANY FOG IN THE
FORECAST. AS THE JET DROPS A LITTLE FURTHER SOUTH LATE TONIGHT
THERE WILL BE A LITTLE THINNING AND DISSIPATING OF THE HIGHER
CLOUDS OVER NORTHERN ZONES. THIS MAY ALLOW FOR A LITTLE FOG TO
SNEAK IN LATE...BUT PROBABILITIES ARE NOT HIGH ENOUGH TO ADD TO
THE FORECAST. A WORSE CASE SCENARIO WOULD BE IN LOW STRATUS/FOG
DEVELOP UPSTREAM AND ADVECT IN WITH THE NW AND NORTH FLOW CLOSER
TO DAYBREAK. THIS SEEMS UNLIKELY THOUGH AT THIS STAGE.
ISENTROPIC UPGLIDE IS WEAK AND DIMINISHES WITH TIME...THUS THE
RISK FOR ANY LIGHT PRECIP IS EXTREMELY SMALL. ALTHOUGH THE
PROXIMITY TO THE COASTAL TROUGH AND DEVELOPING LOW OVER THE
ATLANTIC IT CANNOT BE ENTIRELY RULED OUT ACROSS CHARLESTON AND
BERKELEY COUNTY VERY LATE TONIGHT.
LOW TEMPERATURES TONIGHT WILL BE A TAD ABOVE NORMALS FOR THE
FIRST WEEK OF DECEMBER...RANGING FROM THE LOWER 40S ALONG NW
SECTIONS...MIDDLE AND UPPER 40S MOST ELSEWHERE...EXCEPT CLOSER TO
50 ON THE BARRIER ISLANDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
MONDAY...A SHORTWAVE TROUGH WILL RAPIDLY CROSS THE EAST COAST DURING
THE MORNING HOURS...PROVIDING THE NECESSARY ENERGY TO ORGANIZE A
WAVE OF LOW PRESSURE OFF THE CAROLINA COASTLINE. AS THE SHORTWAVE
MOVES QUICKLY INTO THE ATLANTIC WATERS...THE INTENSIFYING COASTAL
LOW WILL PULL NORTHEAST TO FOLLOW THE UPPER LEVEL FEATURE. DESPITE
THE PRESENCE OF SHORTWAVE ENERGY EARLY IN THE DAY...SOLID
WEST/NORTHWEST FLOW THROUGHOUT THE COLUMN AND WEAK HIGH PRESSURE
BEHIND THE COASTAL LOW WILL LIKELY SUPPRESS PRECIPITATION POTENTIAL.
NUMERICAL MODELS HAVE BEEN TRENDING DRIER FOR MONDAY...AND HAVE THUS
DECREASED RAIN CHANCES BELOW 15 PERCENT ALL AREAS ACCORDINGLY. THICK
CLOUD COVER WILL PREVAIL...YET DOWNSLOPE FLOW WILL SUPPORT SLIGHTLY
WARMER TEMPERATURES THAN THE PREVIOUS DAYS. HIGH TEMPERATURES WILL
REACH THE MID TO UPPER 60S...WITH LOWS IN THE 40 DEGREE RANGE.
TUESDAY AND WEDNESDAY...WEAK HIGH PRESSURE WILL GENERALLY PREVAIL
ACROSS THE SOUTHEAST STATES...WHILE PROGRESSIVE ZONAL FLOW ALOFT
ON TUESDAY TRANSITIONS INTO UPPER RIDGING BY WEDNESDAY. ANY
NOTABLE ENERGY ALOFT WILL REMAIN NORTH AND SOUTH OF THE FORECAST
AREA DURING THE PERIOD...WITH BEST PRECIPITATION POTENTIAL
CONFINED WEST OF THE AREA NEAR A DEVELOPING COLD FRONT OVER THE
OHIO/TENNESSEE VALLEYS. THUS WILL CONTINUE TO CAP RAIN CHANCES
BELOW 15 PERCENT INTO THE MID WEEK PERIOD. GRADUALLY RISING
HEIGHTS ALOFT...FLOW BECOMING MORE SOUTH/SOUTHWEST...AND LESS
CLOUD COVER WILL ALLOW THE WARMING TREND TO CONTINUE. HIGH
TEMPERATURES WILL PEAK IN THE UPPER 60S TUESDAY AND AROUND 70
WEDNESDAY AFTERNOON. LOW TEMPERATURES WILL ALSO BECOME MORE
MILD...ONLY FALLING TO AROUND 50 DEGREES AS DEWPOINTS STEADILY
RISE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
CONDITIONS WILL REMAIN QUIET/DRY THROUGH LATE WEEK AS THE AREA
REMAINS SITUATED ALONG THE WESTERN EDGE OF SFC HIGH PRESSURE.
PERSISTENT SOUTHERLY FLOW ALONG WITH MID LVL RIDGING FROM THE
SOUTHWEST WILL LIKELY LEAD TO A WARMING TREND OVER THE AREA
THROUGH LATE WEEK. IN GENERAL...HIGH TEMPS SHOULD WARM TO AROUND
70 ON THURSDAY...THEN MID 70S ON FRIDAY. OVERNIGHT LOWS SHOULD
RANGE IN THE UPPER 40S INLAND TO MID 50S ALONG THE COAST WEDNESDAY
NIGHT...THEN LOW 50S INLAND TO UPPER 50S ALONG THE COAST THURSDAY
NIGHT.
PRECIP CHANCES SHOULD THEN INCREASE THIS WEEKEND AS A COLD FRONT
BEGINS SHIFTING THROUGH THE SOUTHEASTERN UNITED STATES. HAVE
INTRODUCED CHANCE POPS OVER ALL LOCATIONS ON SATURDAY AND SUNDAY
WHEN COLD FROPA IS ANTICIPATED. OVERALL HIGH TEMPS SHOULD RANGE IN
THE MID/UPPER 60S ON SATURDAY AS CLOUD COVER AND PRECIP COVERAGE
INCREASE. AFTERNOON HIGH TEMPS WILL CONTINUE TO COOL DOWN INTO THE
LOW 60S ON SUNDAY AS THE FRONT SHIFTS OFFSHORE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
KCHS...CIGS IFR AT 06Z AND LATEST RAP SOUNDINGS SUGGEST CIGS MAY
LOWER A BIT MORE BEFORE IMPROVING TOWARD DAYBREAK AS A LIGHT
NW FLOW DEVELOP. UPSTREAM CIGS OVER INLAND AREAS ARE CURRENTLY
VFR WITH MVFR VSBYS. WE IMPROVE CONDITIONS MID MORNING THEN VFR
CONDITIONS BY LATE MORNING THROUGH THIS EVENING.
KSAV...MVFR OR IFR CIGS COULD DEVELOP THE NEXT FEW HOURS UNDER
A STRONG INVERSION BUT CONDITIONS SHOULD IMPROVE BY MID MORNING
AND VFR WILL PERSIST FOR THE REMAINDER OF THE DAY INTO THIS EVENING.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD PREVAIL THROUGH
LATE WEEK. MAYBE SOME FOG POTENTIAL DURING THE EARLY MORNINGS
WEDNESDAY AND AGAIN THURSDAY.
&&
.MARINE...
TONIGHT...THE BEST PRESSURE FALLS CONTINUE TO BE FOUND EAST AND NE
OF CHARLESTON...AND RADAR TRENDS SHOWING SOME FLARE-UP OF SHOWERS
OUT NEAR THE WEST WALL OF THE GULF STREAM. THIS IS INDICATIVE THAT
A WEAK LOW IS STARTING TO FORM ALONG THE COASTAL TROUGH. NORTH
WINDS WILL BACK AROUND TO THE NW AS THIS FEATURE FORMS AND LAND
BREEZE CIRCULATIONS SET IN OVERNIGHT. SPEEDS COULD INCREASE A HAIR
OVER THE AMZ350 WATERS AS THE PRESSURE GRADIENT AROUND THE LOW
TIGHTENS...BUT OVERALL WINDS WILL BE NO HIGHER THAN ABOUT 10 OR 15
KT IN THE ATLANTIC AND 5 KT IN CHARLESTON HARBOR. SEAS HAVE
FINALLY FALLEN ENOUGH WHERE WE HAVE DROPPED THE SCA FOR
AMZ374...AND SEAS TONIGHT WILL BE NO MORE THAN 3-5 FT...A LITTLE
LESS NEAR THE IMMEDIATE COAST.
MONDAY THROUGH FRIDAY...WINDS/SEAS WILL REMAIN WELL BELOW SMALL
CRAFT ADVISORY LEVELS...AS A SURFACE LOW DEEPENS OFFSHORE ON
MONDAY AND LIFTS NORTHEAST AND AWAY FROM THE REGION THROUGH
TUESDAY. WEAK HIGH PRESSURE WILL THEN SETTLE OVER THE WATERS
THROUGH THURSDAY...WITH WINDS EXPECTED TO REMAIN AT OR BELOW
10-15 KT AND SEAS FALLING TO 3 FT OR LESS BY LATE MONDAY.
WINDS/SEAS WILL THEN GRADUALLY INCREASE/BUILD TO 15-20 KT AND 4-5
FT ON FRIDAY...AS THE PRESSURE GRADIENT BEGINS TO TIGHTEN BETWEEN
HIGH PRESSURE OVER THE WESTERN ATLANTIC AND A COLD FRONT
APPROACHING INLAND.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE HIGH THROUGH MID-WEEK DUE TO ASTRONOMICAL
INFLUENCES OF THE UPCOMING PERIGEE AND NEW MOON /PERIGEAN SPRING
TIDES/. IT/LL ONLY TAKE A SMALL DEPARTURE TO GENERATE SHALLOW
COASTAL FLOODING WITH THE NEXT HIGH TIDE ALONG THE CHARLESTON
COUNTY AND LOWER COLLETON COUNTY COASTS...AND A COASTAL FLOOD
ADVISORY MIGHT BE REQUIRED FOR THE HIGH TIDE JUST BEFORE 7 AM
MONDAY. ADDITIONAL COASTAL FLOOD ADVISORIES MIGHT BE NEEDED
TUESDAY MORNING AND AGAIN WEDNESDAY MORNING WITH THOSE HIGH TIDES
AS WELL.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...WMS
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...UPDATE
NWS PEACHTREE CITY GA
1231 AM EST MON DEC 2 2013
.UPDATE...
/ISSUED AT 951 PM EST SUN DEC 1 2013/
NO CHANGES PLANNED AT THIS TIME. THERE REMAINS SOME UNCERTAINTY AS
TO WHERE THE LIGHT RAIN WILL IMPACT THE FORECAST AREA...TIMING
AROUND AND JUST AFTER MORNING RUSH HOUR LOOKS GOOD...CONFIDENCE IS
STILL TOO LOW TO MAKE ANY CHANGES.
&&
.PREV DISCUSSIONS... /ISSUED 214 PM EST SUN DEC 1 2013/
SHORT TERM /TONIGHT THROUGH TUESDAY/...
LATEST SURFACE ANALYSIS OVER THE SOUTHEAST UNITED STATES SHOWS
WEAK HIGH PRESSURE CONTINUING TO BE THE DOMINATING INFLUENCE OF
THE LOCAL WX. EAST AND SOUTHEAST FLOW ON SOUTHERN PERIPHERY OF
THIS HIGH EARLIER ALLOWED FOR LOW LEVEL MOISTURE TO ADVECT IN A
RESULT IN WIDESPREAD LOW CLOUDS. SINCE THEN...DEVELOPING
SOUTHWEST FLOW DUE TO A SHIFT IN THE HIGH POSITION HAS ALLOWED
FOR THE EROSION OF MOST OF THE LOW CLOUDS BUT HAS QUICKLY BEEN
REPLACED BY A THIN VEIL OF CIRRUS. TEMPS LOOKS TO BE LARGELY
UNAFFECTED BY THIS AS WE ARE ALREADY WITHING THREE DEGREES OF
FORECAST HIGH OF ATLANTA CURRENTLY.
FOR TONIGHT...THE FIRST IN A SERIES OF EMBEDDED SHORTWAVES WILL
MOVE THROUGH ZONAL FLOW TO PRODUCE AN AREA OF MAINLY LIGHT RAIN
OVER ALABAMA. MODELS HAVE BEEN BACKING OFF ON HOW MUCH THIS
ENERGY TRANSLATES INTO ACTUAL PRECIP OVER OUR AREA AND INDEED
FEEL AMOUNTS WILL BE ON THE LOW SIDE EVEN OVER WESTERN PORTIONS.
THAT SAID...BASED ON WRF AND HRRR RUNS...IT SHOULD STILL RAIN
EVEN IF ITS LIGHT AND HAVE UPPED CHANCES ALONG THE WEST CENTRAL
BORDER THROUGH 15Z MONDAY. WILL LET EVENING AND MID SHIFT TAKE
ANOTHER LOOK AS MAY STILL BE TOO LOW...GOING JUST BELOW LIKELY AT
THIS POINT.
WAVE CLEARS DURING THE AFTERNOON BUT ANOTHER WILL BE RIGHT ON ITS
HEELS INTO MONDAY NIGHT. THIS ONE WILL BE MOVING MORE SOUTHWEST
TO NORTHEAST TO AFFECT MAINLY THE NORTHERN TIER WITH MID RANGE
CHANCE POPS. IN ADDITION TO LIGHT RAIN...COULD SEE SOME PATCHY
FOG DEVELOPMENT WITH THIS SYSTEM OVER THE MOUNTAINS AND ALONG OUR
WESTERN BORDER WITH ALABAMA.
INCREASING TEMPERATURES THROUGH THE SHORT TERM WITH MID 60S TO
AROUND 70 EXPECTED BY TUESDAY AFTERNOON. THIS WOULD BE A RADICAL
DEPARTURE FROM THE EXTREME COLD OF THIS PAST WEEK AND WOULD
RESULT IN TEMPS SOME 10 DEGREES ABOVE CLIMO.
DEESE
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
SOME CHANGES MADE TO THE EXTENDED BASED ON GUIDANCE WHICH IS
COMING IN QUITE A BIT WARMER FOR LATER IN THE WEEK. AHEAD OF THE
FRONT PROGGED TO STALL ACROSS THE TENNESSEE VALLEY WHICH WILL
SLOWLY MAKE ITS WAY TO THE SOUTHERN APPALACHIANS BY FRIDAY.
RIDGING IN THE GULF REMAINS PRETTY STRONG BUT ALSO STRONGER LOW-
LEVEL WAA. INCREASED TEMPS QUITE A BIT AND ACTUALLY HAVE NEAR-
RECORD TO RECORD WARM MIN TEMPS FOR FRIDAY MORNING. POPS STILL
LOOKING GOOD BUT WILL PROBABLY HAVE TO INCREASE THEM AS WE
PROGRESS THROUGH THE WEEK.
THERE IS SOME CONCERN ABOUT HAZARDOUS WEATHER AS GFS CAPES ARE ON
THE INCREASE ESPECIALLY FOR FRIDAY AFTERNOON AND SOME QPF VALUES
ARE PRETTY HEFTY...BUT WILL NARROW THAT DOWN AS WE GET CLOSER. A
LOT OF UNCERTAINTY ON TIMING OF FROPA AND SUBSEQUENT CAD ONSET...
ECMWF A LITTLE FASTER THAN THE GFS ON FROPA BUT BOTH HAVE SIMILAR
TIMING WITH CAD ONSET....SO MADE NO CHANGES TO SATURDAY /AS THE
SIGNIFICANT COOL-DOWN STARTS/ AND BEYOND BECAUSE OF THAT
UNCERTAINTY. WILL BE INTERESTING TO SEE WHAT SENSIBLE WEATHER
IMPACTS OCCUR WITH THE DIABATICALLY-ENHANCED CAD EVENT FOR EARLY
NEXT WEEK. SEE PREVIOUS DISCUSSION BELOW.
TDP
&&
.AVIATION...
06Z UPDATE...
CURRENT VFR CIGS WILL LOWER TO MVFR LEVELS BY 10-12Z THIS MORNING AS
AN UPPER DISTURBANCE APPROACHES AND SPREADS PATCHES OF -RA ACROSS
THE AREA THRU AT LEAST THE MORNING HOURS... MAINLY BETWEEN 10-18Z
TODAY ACROSS ATLANTA TAF SITES. CIGS MAY IMPROVE TO VFR LEVELS THIS
AFTERNOON... BUT GUIDANCE SUGGEST THIS MAY BE BRIEF AS MVFR CIGS
SETTLE BACK IN BY 00-03Z THIS EVENING. CURRENT WEST WINDS WILL BACK
SW THIS AFTERNOON... THEN SOUTHERLY TONIGHT...POSSIBLY BECOMING MORE
SSE BY 10-12Z TUE MORN. WIND SPEEDS WILL BE 7KTS OR LESS TODAY...
THEN NEARLY CALM TONIGHT.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON CIGS/WEATHER.
HIGH CONFIDENCE WINDS/VISIBILITY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 56 39 60 48 / 5 10 20 30
ATLANTA 59 45 59 49 / 5 20 50 30
BLAIRSVILLE 56 37 53 45 / 5 10 30 30
CARTERSVILLE 55 40 56 48 / 5 40 40 30
COLUMBUS 63 46 65 50 / 5 20 20 20
GAINESVILLE 54 42 55 48 / 5 10 20 30
MACON 58 42 66 44 / 5 10 20 20
ROME 54 41 56 48 / 0 40 50 30
PEACHTREE CITY 57 40 60 43 / 5 20 50 30
VIDALIA 55 47 66 48 / 5 5 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ATWELL/39
LONG TERM....SNELSON
AVIATION...39
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1000 PM CST TUE DEC 3 2013
.UPDATE...
ISSUED AT 941 PM CST TUE DEC 3 2013
WARM FRONT NEAR QUAD CITIES ATTIM...WITH WIDESPREAD DENSE FOG
CONTINUING TO BE FOUND NORTH OF THE BOUNDARY. THE WARM
FRONT HAS NOT MOVED MUCH THIS EVENING WITH AS AXIS OF PRESSURE
RISES PASSING THROUGH. GIVEN THIS ALONG WITH LIGHT WINDS AND
ABUNDANT HAVE BEEN GETTING REPORTS OF PATCHY TO AREAS OF DENSE
FOG IN SOUTHEAST CWA SOUTH OF THE WARM FRONT. WITH THINGS
UNCHANGED NEXT FEW HOURS BELIEVE WILL SEE SOME EXPANSION TO THE
DENSE FOG AND HAVE GONE AHEAD AND ADDED REMAINING SOUTHEAST CWA
COUNTIES INTO DENSE FOG ADVISORY. MAY ACTUALLY BE ABLE TO TRIM
THE ADVISORY LATER TONIGHT ESPECIALLY FROM QUAD CITIES E/SE IF THE
WARM FRONT LIFTS NORTH AS MODELS SUGGEST ALLOWING FOR SLIGHT
WARMING AND INCREASE IN WINDS TO ABATE WIDESPREAD DENSE FOG.
&&
.SYNOPSIS...
ISSUED AT 340 PM CST TUE DEC 3 2013
WARM FRONT REACHING FROM DEVELOPING LOW OVER SE CO REACHED E-NE
ACROSS CENTRAL KS TO S CENTRAL IA TO N CENTRAL IL THIS AFTERNOON. AT
21Z...SURFACE ANALYSIS AND VISIBLE SATELLITE IMAGERY INDICATED THE
BOUNDARY BETWEEN FAIRFIELD AND WASHINGTON SE TO BETWEEN GALESBURG AND
MACOMB. FOG WAS WIDESPREAD NORTH OF THIS BOUNDARY AND HAS REMAINED
DENSE THROUGH THE DAY ALONG THE HIGHWAY 20 CORRIDOR. SOUTH OF THE
BOUNDARY...TEMPERATURES WERE IN THE 50S...WHILE 40S WERE FOUND TO
THE NORTH. THE PRIMARY PUSH OF ARCTIC AIR WAS STILL IN THE
PLAINS...WHERE THE MAIN COLD FRONT REACHED FROM NW MN S-SW TO THE
NEB PANHANDLE. BEHIND THIS BOUNDARY...TEMPERATURES WERE IN THE TEENS
AND 20S.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 340 PM CST TUE DEC 3 2013
THE REBOUND OF WIDESPREAD DENSE FOG IS THE INITIAL CHALLENGE...THEN
TRENDS WITH THE PASSAGE OF THE STRONG COLD FRONT THAT IS NOW LIKELY
TO PUSH THROUGH WED AFTERNOON.
THE WARM FRONT WILL TRY TO PUSH NORTH TONIGHT AS THE CO LEE LOW
MIGRATES NORTHEAST ALONG THE BOUNDARY IN KS. THE BROAD LOW LEVEL
CONVERGENT FLOW AND MOISTURE ADVECTION AS DEWPOINTS IN THE 40S OVER
MO AND IL ARE DRAWN NORTH AND NORTHWESTWARD WILL KEEP THE LOW LEVELS
SATURATED. THE HRRR AND SREF FOG PROG TOOLS ARE IN ALIGNMENT WITH
THE CURRENT AREA OF DENSE FOG AND HAVE THIS EXPANDING BACK SOUTH AND
SOUTHWEST OVERNIGHT. THIS IS ALONG THE AREA OF CURRENT CONVERGENCE
FROM S CENTRAL IA NE TO NW IL AND HAVE EXPANDED OUR DENSE FOG
ADVISORY TO COVER THESE AREAS OVERNIGHT. HAVE THIS GOING UNTIL NOON
WEDNESDAY...WHEN THE ENHANCED MIXING AHEAD OF THE FRONT SHOULD BRING
SOME IMPROVEMENT. ACROSS FAR SOUTHEAST IA...FAR NE MO AND WEST
CENTRAL IL ALONG THE I-80 CORRIDOR...FOG WILL LIKELY RETURN...BUT
THERE IS LOW CONFIDENCE AS TO WHETHER IT WILL BECOME DENSE. HAVE
THUS HELD OFF ON AN ADVISORY...BUT WILL NEED TO MONITOR CLOSELY.
OTHERWISE...THE DEVELOPING LIFT AND INCREASING DIFLUENCE IN FLOW
ALOFT WILL SUPPORT ANOTHER ROUND OF LIGHT RAIN...ESPECIALLY TOWARD
MORNING ACROSS THE NORTH AND HAVE MAINTAINED CHANCE POPS.
ELSEWHERE...WILL KEEP A MENTION OF DRIZZLE WITH THE FOG.
WEDNESDAY...LATEST MODELS CONTINUE TO TREND TOWARD THE
EARLIER...SLOWER ECMWF RUNS WITH THE TIMING OF THE FROPA. THE
GFS...NAM...ECMWF...AND GEM OFFER SIMILAR SOLUTIONS WITH THE WAVE OF
LOW PRESSURE MOVING OUT OF THE PLAINS...LIFTING THROUGH THE FORECAST
AREA WEDNESDAY AFTERNOON. THIS USHERS THE PRIMARY COLD FRONT THROUGH
THE AREA BY EARLY EVENING. HAVE TRENDED THE FORECAST TOWARD THE
SLIGHTLY SLOWER ECMWF AND CANADIAN SOLUTIONS...KEEPING THE
PRECIPITATION IN THE FORM OF RAIN WITH A POSSIBLY RAIN/SNOW MIX IN
THE FAR NW LATE. WITH THE PRIMARY WARM SECTOR SWEEPING THROUGH THE
MUCH OF THE WARM SECTOR...WE SHOULD TAP INTO THE AIRMASS OVER
EASTERN MO AND SOUTHERN IL RESULTING IN MORNING OR EARLY AFTERNOON
HIGHS FROM THE LOWER 40S NW TO NEAR 60 IN THE FAR SE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 340 PM CST TUE DEC 3 2013
WEDNESDAY NIGHT THROUGH FRIDAY...TAKING INTO ACCOUNT A TYPE OF
ENSEMBLE FRONTAL MOVEMENT OF THE 12Z MODEL RUNS AND EVEN SLOWING
THAT DOWN SOME AS DEEPENING CYCLONE WRAPS UP SOMEWHERE ACRS
SOUTHWEST INTO CENTRAL WI WED EVENING...IT SHOULD BE PUSHING EAST OF
THE DVN CWA BY 01Z-02Z THU. CONVERGENT FORCING OFF THIS PROCESS MAY
WRING OUT SOME LIGHT RAIN OR DRIZZLE ALONG AND EAST OF THE MS RVR THE
FIRST 1-2 HRS OF THE FCST PERIOD. BUT THE MAIN OVERNIGHT WX STORY
WILL BE THE INCREASING WESTERLY POST-FRONTAL SFC WINDS AND DEVELOPING
LLVL COLD CONVEYOR IN-WRAPPING FROM THE NORTHWEST. BRISK WEST WINDS
OF 15 TO 25+ MPH SHOULD COLD AIR ADVECT TEMPS INTO THE UPPER TEENS
IN THE NORTHWEST...TO THE MID 20S IN THE EAST BY THU MORNING. THE
12Z RUNS THEN SUGGEST THAT AS 1035-1040 MB HIGH DUMPS DOWN THE
NORTHWESTERN PLAINS AND TIGHT CYCLONIC GRADIENT LINGERS SOME OFF
NORTHERN GRT LKS DEEP LOW PRESSURE CENTER...WINDY CONDITIONS TO
CONTINUE THROUGH AT LEAST MIDDAY THU WITH AMBIENT TEMPS ONLY
RECOVERING 3-5 DEGREES FROM MORNING VALUES AT 12Z THU. SINGLE DIGIT
ABOVE ZERO WIND CHILLS IN THE NORTHWESTERN HALF OF THE CWA THU AM.
THE ARCTIC FRONT SURGES SOUTH AND PRODUCES TIGHTENING LLVL
BAROCLINICITY AS IT SLOWS UNDER SOUTHWESTERLIES ACRS THE DEEP
SOUTHERN PLAINS TO SOUTHEASTERN OH RVR VALLEY. ALONG AND NORTH OF
THIS THERMAL RIBBON TO BE AN AXIS FOR WINTER STORM/ICE CONDITIONS
INTO FRI AND THERE IS STILL SOME VARIANCE BETWEEN THE LATEST RUN
SOLUTIONS OF FRONTAL PLACEMENT AND STRENGTH OF A WAVE RIPPLING UP
ALONG THIS HIGHWAY. THE MAJORITY OF THE 12Z MODEL RUNS STILL KEEP
ANY OVERRUNNING SNOW OFF TO THE SOUTHEAST OF THE CWA THU THROUGH FRI
WITH JUST A MID AND HIGH LEVEL CLOUD DECK MOVING UP ACRS PORTIONS OF
THE CWA LATE IN THE DAY AND OVERNIGHT. BUT THE 12Z RUN NAM AND GEM
ARE MORE BULLISH AND FURTHER NORTH WITH THE OVERRUNNING PRECIP
SHIELD AND CLIP AT LEAST THE SOUTHEASTERN THIRD OF THE DVN CWA WITH
LIGHT SNOW THU NIGHT INTO FRI MORNING. FOR NOW WILL MAINTAIN SLIGHT
CHC POPS ACRS THE FAR SOUTH AND SOUTHEASTERN CORNER OF THE FCST
AREA. MOSTLY CLOUDY...BLUSTERY AND COLD CONDITIONS CONTINUE ON FRI
WITH HIGHS ONLY IN THE UPPER TEENS TO LOWER 20S. THE INCOMING SFC
RIDGE WILL LOOK TO UNFOLD ACRS THE UPPER MS RVR VALLEY FRI NIGHT FOR
CLEARING...SFC WIND DECREASING AND COLD CONDITIONS. MANY LOWS IN THE
SINGLE DIGITS WITH A ZERO EVEN POSSIBLE IN THE NORTHWEST.
SATURDAY AND SUNDAY...THE SFC RIDGE MAINTAINS LOCALLY LONG ENOUGH FOR
A FAIR WX BUT COLD DAY SAT WITH HIGHS IN THE TEENS TO AROUND 20 AS
L/W TROF LOOMS ACRS THE SOUTHWESTERN CONUS/GRT BSN. THE MEDIUM RANGE
SOLUTIONS THEN SUGGEST NORTHERN STREAM UPPER JET ENERGY/TROFFINESS
ACRS WESTERN INTO CENTRAL CANADA TO TRY AND PHASE WITH THIS SW
CONUS LONG WAVE. THE LATEST MODEL RUNS PROBABLY STILL TRYING TO GET A
HANDLE ON THIS PROCESS AND IT WILL BE SUBJECT TO CHANGE...BUT THE
CURRENT SIGNAL SUGGESTS AT LEAST A DECENT SIZED PIECE OF WAVE ENERGY
EJECTING OUT OF THE SOUTHERN PLAINS AND THEN SOMEWHERE UP THE OH
RVR VALLEY OR EVEN FURTHER TO THE NORTHWEST SUNDAY INTO MONDAY. WITH
COLD AIR IN PLACE...THIS COULD SPELL AN EXTENDED PERIOD OF SNOW
MOVING UP ACRS PORTIONS OR ALL OF THE DVN CWA STARING OUT LATE SAT
NIGHT IN THE SOUTHWEST...AND THEN CONTINUING THROUGH LATE SUNDAY
NIGHT OR EARLY MON MORNING. THE CURRENT MODELS INCLUDING THE 12Z RUN
GFS AND ECMWF SUGGEST THE BETTER MOISTURE TRANSPORT TO FUEL HEAVIER
PRECIP TO GET PINCHED OFF/REMAIN TO THE SOUTH AND SOUTHEAST OF THE
LOCAL FCST AREA...WITH JUST SECONDARY SNOWS OF 1-3 INCHES ACRS THE
DVN CWA BY 12Z MON...SNOW MOVING OUT JUST AFTER THAT TIME-FRAME. BUT
THE DURATION/24 HRS OF ROUNDS OF AT LEAST LIGHT TO OCCASIONAL
MODERATE SNOW AND HIGHER LSR/S SUGGEST AMOUNTS COULD ADD UP TO BE
MORE. IF THE MOISTURE CONVEYOR IS LESS IMPEDED AND THE SYSTEM PULLS
UP FURTHER TO THE NORTHWEST...THERE MAY BE THE POTENTIAL FOR A MORE
SIGNIFICANT WINTER STORM IN PORTIONS OF OR CLOSE TO THE LOCAL AREA.
A WINDOW TO WATCH FOR SURE...AND WILL HAVE TO SEE HOW ADDITIONAL
MODEL RUNS BEHAVE AND HANDLE THE PHASING PROCESS. WILL RAISE THE CHC
POPS FOR NOW FOR SUNDAY NIGHT.
NEXT MONDAY AND TUESDAY...THE LONGER RANGE SIGNALS SUGGEST THAT
AFTER WHAT KIND OF SYSTEM CAN MAKE IT THROUGH OR CLOSE TO THE AREA
SUNDAY INTO EARLY MONDAY...A VERY COLD AIRMASS THEN LOOMS ACRS
CANADA. THE FRESHLY PHASED L/W TROF WILL THEN BECOME COLD CORE AND
ACT AS AN ARCTIC CONDUIT ALLOWING A COLD DUMP DOWN THE NORTHERN
PLAINS AND UPPER MIDWEST LATER MONDAY INTO TUE. THE 12Z GFS HAS A
FRIGID H85 MB COLD POOL OF -20 TO -26C BARRELING IT/S WAY DOWN
ACRS MOST OF THE CWA BY 12Z TUE...THE 12Z ECMWF IS ADVERTISING -19 TO
-21C. EVEN WITH MIXING WINDS WHICH WILL BE BRISK IN THIS TYPE OF
CAA UNDER CYCLONIC FLOW...TEMPS BY TUE MORNING MAY GO SUB-ZERO. MAY
BE WIND CHILL ADVISORY CRITERIA ATTAINED IN PORTIONS OF THE AREA LATE
MON NIGHT AND THROUGH MIDDAY TUE. WELL AGAIN...MANY SYSTEMS AND
PHASING PROCESSES TO GO THROUGH TO GET TO THIS EXTENDED PERIOD BUT
WILL START TO TREND TEMPS DOWN. ..12..
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 543 PM CST TUE DEC 3 2013
WARM FRONT EXTENDS BETWEEN KMLI AND KBRL. NORTH OF THE WARM
FRONT WIDESPREAD FOG AND LOW CLOUDS WERE RESULTING IN IFR TO
LIFR CONDITIONS WITH POCKETS OF VLIFR. SOUTH OF THE WARM FRONT
SOME AREAS OF MVFR CONDITIONS WERE FOUND INCLUDING AT KBRL.
OVERALL...CONDITIONS WILL LIKELY BE THE WORST AT KDBQ WHERE LOW
CLOUDS...DENSE FOG AND DRIZZLE TO RESULT IN CONTINUATION OF LIFR
TO VLIFR CONDITIONS THROUGH WED AM. KBRL MAY REMAIN PREDOMINATELY
MVFR UNTIL OVERNIGHT AND KMLI BEING NEAR THE WARM FRONT COULD SEE
SOME IMPROVEMENT TO MVFR THIS EVENING WHILE KCID SHOULD STAY
GENERALLY IFR OR LOWER. ALL SITES SHOULD THEN LOWER ONCE AGAIN
OVERNIGHT TO IFR/LIFR WITH SOME VLIFR IN DENSE FOG... LOW CLOUDS
AND DRIZZLE AND REMAIN SO UNTIL LATER WED AM INTO WED AFTN WHEN A
COLD FRONT APPROACHES. THE COLD FRONT SHOULD DISSIPATE DENSE FOG
BUT MAINTAIN IFR/MVFR CONDITIONS IN LIGHT FOG AND LOW CLOUDS WITH
SOME LIGHT RAIN.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR CLARK-SCOTLAND.
&&
$$
UPDATE...05
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...12
AVIATION...05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
605 PM CST TUE DEC 3 2013
.SYNOPSIS...
ISSUED AT 340 PM CST TUE DEC 3 2013
WARM FRONT REACHING FROM DEVELOPING LOW OVER SE CO REACHED E-NE
ACROSS CENTRAL KS TO S CENTRAL IA TO N CENTRAL IL THIS AFTERNOON. AT
21Z...SURFACE ANALYSIS AND VISIBLE SATELLITE IMAGERY INDICATED THE
BOUNDARY BETWEEN FAIRFIELD AND WASHINGTON SE TO BETWEEN GALESBURG AND
MACOMB. FOG WAS WIDESPREAD NORTH OF THIS BOUNDARY AND HAS REMAINED
DENSE THROUGH THE DAY ALONG THE HIGHWAY 20 CORRIDOR. SOUTH OF THE
BOUNDARY...TEMPERATURES WERE IN THE 50S...WHILE 40S WERE FOUND TO
THE NORTH. THE PRIMARY PUSH OF ARCTIC AIR WAS STILL IN THE
PLAINS...WHERE THE MAIN COLD FRONT REACHED FROM NW MN S-SW TO THE
NEB PANHANDLE. BEHIND THIS BOUNDARY...TEMPERATURES WERE IN THE TEENS
AND 20S.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 340 PM CST TUE DEC 3 2013
THE REBOUND OF WIDESPREAD DENSE FOG IS THE INITIAL CHALLENGE...THEN
TRENDS WITH THE PASSAGE OF THE STRONG COLD FRONT THAT IS NOW LIKELY
TO PUSH THROUGH WED AFTERNOON.
THE WARM FRONT WILL TRY TO PUSH NORTH TONIGHT AS THE CO LEE LOW
MIGRATES NORTHEAST ALONG THE BOUNDARY IN KS. THE BROAD LOW LEVEL
CONVERGENT FLOW AND MOISTURE ADVECTION AS DEWPOINTS IN THE 40S OVER
MO AND IL ARE DRAWN NORTH AND NORTHWESTWARD WILL KEEP THE LOW LEVELS
SATURATED. THE HRRR AND SREF FOG PROG TOOLS ARE IN ALIGNMENT WITH
THE CURRENT AREA OF DENSE FOG AND HAVE THIS EXPANDING BACK SOUTH AND
SOUTHWEST OVERNIGHT. THIS IS ALONG THE AREA OF CURRENT CONVERGENCE
FROM S CENTRAL IA NE TO NW IL AND HAVE EXPANDED OUR DENSE FOG
ADVISORY TO COVER THESE AREAS OVERNIGHT. HAVE THIS GOING UNTIL NOON
WEDNESDAY...WHEN THE ENHANCED MIXING AHEAD OF THE FRONT SHOULD BRING
SOME IMPROVEMENT. ACROSS FAR SOUTHEAST IA...FAR NE MO AND WEST
CENTRAL IL ALONG THE I-80 CORRIDOR...FOG WILL LIKELY RETURN...BUT
THERE IS LOW CONFIDENCE AS TO WHETHER IT WILL BECOME DENSE. HAVE
THUS HELD OFF ON AN ADVISORY...BUT WILL NEED TO MONITOR CLOSELY.
OTHERWISE...THE DEVELOPING LIFT AND INCREASING DIFLUENCE IN FLOW
ALOFT WILL SUPPORT ANOTHER ROUND OF LIGHT RAIN...ESPECIALLY TOWARD
MORNING ACROSS THE NORTH AND HAVE MAINTAINED CHANCE POPS.
ELSEWHERE...WILL KEEP A MENTION OF DRIZZLE WITH THE FOG.
WEDNESDAY...LATEST MODELS CONTINUE TO TREND TOWARD THE
EARLIER...SLOWER ECMWF RUNS WITH THE TIMING OF THE FROPA. THE
GFS...NAM...ECMWF...AND GEM OFFER SIMILAR SOLUTIONS WITH THE WAVE OF
LOW PRESSURE MOVING OUT OF THE PLAINS...LIFTING THROUGH THE FORECAST
AREA WEDNESDAY AFTERNOON. THIS USHERS THE PRIMARY COLD FRONT THROUGH
THE AREA BY EARLY EVENING. HAVE TRENDED THE FORECAST TOWARD THE
SLIGHTLY SLOWER ECMWF AND CANADIAN SOLUTIONS...KEEPING THE
PRECIPITATION IN THE FORM OF RAIN WITH A POSSIBLY RAIN/SNOW MIX IN
THE FAR NW LATE. WITH THE PRIMARY WARM SECTOR SWEEPING THROUGH THE
MUCH OF THE WARM SECTOR...WE SHOULD TAP INTO THE AIRMASS OVER
EASTERN MO AND SOUTHERN IL RESULTING IN MORNING OR EARLY AFTERNOON
HIGHS FROM THE LOWER 40S NW TO NEAR 60 IN THE FAR SE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 340 PM CST TUE DEC 3 2013
WEDNESDAY NIGHT THROUGH FRIDAY...TAKING INTO ACCOUNT A TYPE OF
ENSEMBLE FRONTAL MOVEMENT OF THE 12Z MODEL RUNS AND EVEN SLOWING
THAT DOWN SOME AS DEEPENING CYCLONE WRAPS UP SOMEWHERE ACRS
SOUTHWEST INTO CENTRAL WI WED EVENING...IT SHOULD BE PUSHING EAST OF
THE DVN CWA BY 01Z-02Z THU. CONVERGENT FORCING OFF THIS PROCESS MAY
WRING OUT SOME LIGHT RAIN OR DRIZZLE ALONG AND EAST OF THE MS RVR THE
FIRST 1-2 HRS OF THE FCST PERIOD. BUT THE MAIN OVERNIGHT WX STORY
WILL BE THE INCREASING WESTERLY POST-FRONTAL SFC WINDS AND DEVELOPING
LLVL COLD CONVEYOR IN-WRAPPING FROM THE NORTHWEST. BRISK WEST WINDS
OF 15 TO 25+ MPH SHOULD COLD AIR ADVECT TEMPS INTO THE UPPER TEENS
IN THE NORTHWEST...TO THE MID 20S IN THE EAST BY THU MORNING. THE
12Z RUNS THEN SUGGEST THAT AS 1035-1040 MB HIGH DUMPS DOWN THE
NORTHWESTERN PLAINS AND TIGHT CYCLONIC GRADIENT LINGERS SOME OFF
NORTHERN GRT LKS DEEP LOW PRESSURE CENTER...WINDY CONDITIONS TO
CONTINUE THROUGH AT LEAST MIDDAY THU WITH AMBIENT TEMPS ONLY
RECOVERING 3-5 DEGREES FROM MORNING VALUES AT 12Z THU. SINGLE DIGIT
ABOVE ZERO WIND CHILLS IN THE NORTHWESTERN HALF OF THE CWA THU AM.
THE ARCTIC FRONT SURGES SOUTH AND PRODUCES TIGHTENING LLVL
BAROCLINICITY AS IT SLOWS UNDER SOUTHWESTERLIES ACRS THE DEEP
SOUTHERN PLAINS TO SOUTHEASTERN OH RVR VALLEY. ALONG AND NORTH OF
THIS THERMAL RIBBON TO BE AN AXIS FOR WINTER STORM/ICE CONDITIONS
INTO FRI AND THERE IS STILL SOME VARIANCE BETWEEN THE LATEST RUN
SOLUTIONS OF FRONTAL PLACEMENT AND STRENGTH OF A WAVE RIPPLING UP
ALONG THIS HIGHWAY. THE MAJORITY OF THE 12Z MODEL RUNS STILL KEEP
ANY OVERRUNNING SNOW OFF TO THE SOUTHEAST OF THE CWA THU THROUGH FRI
WITH JUST A MID AND HIGH LEVEL CLOUD DECK MOVING UP ACRS PORTIONS OF
THE CWA LATE IN THE DAY AND OVERNIGHT. BUT THE 12Z RUN NAM AND GEM
ARE MORE BULLISH AND FURTHER NORTH WITH THE OVERRUNNING PRECIP
SHIELD AND CLIP AT LEAST THE SOUTHEASTERN THIRD OF THE DVN CWA WITH
LIGHT SNOW THU NIGHT INTO FRI MORNING. FOR NOW WILL MAINTAIN SLIGHT
CHC POPS ACRS THE FAR SOUTH AND SOUTHEASTERN CORNER OF THE FCST
AREA. MOSTLY CLOUDY...BLUSTERY AND COLD CONDITIONS CONTINUE ON FRI
WITH HIGHS ONLY IN THE UPPER TEENS TO LOWER 20S. THE INCOMING SFC
RIDGE WILL LOOK TO UNFOLD ACRS THE UPPER MS RVR VALLEY FRI NIGHT FOR
CLEARING...SFC WIND DECREASING AND COLD CONDITIONS. MANY LOWS IN THE
SINGLE DIGITS WITH A ZERO EVEN POSSIBLE IN THE NORTHWEST.
SATURDAY AND SUNDAY...THE SFC RIDGE MAINTAINS LOCALLY LONG ENOUGH FOR
A FAIR WX BUT COLD DAY SAT WITH HIGHS IN THE TEENS TO AROUND 20 AS
L/W TROF LOOMS ACRS THE SOUTHWESTERN CONUS/GRT BSN. THE MEDIUM RANGE
SOLUTIONS THEN SUGGEST NORTHERN STREAM UPPER JET ENERGY/TROFFINESS
ACRS WESTERN INTO CENTRAL CANADA TO TRY AND PHASE WITH THIS SW
CONUS LONG WAVE. THE LATEST MODEL RUNS PROBABLY STILL TRYING TO GET A
HANDLE ON THIS PROCESS AND IT WILL BE SUBJECT TO CHANGE...BUT THE
CURRENT SIGNAL SUGGESTS AT LEAST A DECENT SIZED PIECE OF WAVE ENERGY
EJECTING OUT OF THE SOUTHERN PLAINS AND THEN SOMEWHERE UP THE OH
RVR VALLEY OR EVEN FURTHER TO THE NORTHWEST SUNDAY INTO MONDAY. WITH
COLD AIR IN PLACE...THIS COULD SPELL AN EXTENDED PERIOD OF SNOW
MOVING UP ACRS PORTIONS OR ALL OF THE DVN CWA STARING OUT LATE SAT
NIGHT IN THE SOUTHWEST...AND THEN CONTINUING THROUGH LATE SUNDAY
NIGHT OR EARLY MON MORNING. THE CURRENT MODELS INCLUDING THE 12Z RUN
GFS AND ECMWF SUGGEST THE BETTER MOISTURE TRANSPORT TO FUEL HEAVIER
PRECIP TO GET PINCHED OFF/REMAIN TO THE SOUTH AND SOUTHEAST OF THE
LOCAL FCST AREA...WITH JUST SECONDARY SNOWS OF 1-3 INCHES ACRS THE
DVN CWA BY 12Z MON...SNOW MOVING OUT JUST AFTER THAT TIME-FRAME. BUT
THE DURATION/24 HRS OF ROUNDS OF AT LEAST LIGHT TO OCCASIONAL
MODERATE SNOW AND HIGHER LSR/S SUGGEST AMOUNTS COULD ADD UP TO BE
MORE. IF THE MOISTURE CONVEYOR IS LESS IMPEDED AND THE SYSTEM PULLS
UP FURTHER TO THE NORTHWEST...THERE MAY BE THE POTENTIAL FOR A MORE
SIGNIFICANT WINTER STORM IN PORTIONS OF OR CLOSE TO THE LOCAL AREA.
A WINDOW TO WATCH FOR SURE...AND WILL HAVE TO SEE HOW ADDITIONAL
MODEL RUNS BEHAVE AND HANDLE THE PHASING PROCESS. WILL RAISE THE CHC
POPS FOR NOW FOR SUNDAY NIGHT.
NEXT MONDAY AND TUESDAY...THE LONGER RANGE SIGNALS SUGGEST THAT
AFTER WHAT KIND OF SYSTEM CAN MAKE IT THROUGH OR CLOSE TO THE AREA
SUNDAY INTO EARLY MONDAY...A VERY COLD AIRMASS THEN LOOMS ACRS
CANADA. THE FRESHLY PHASED L/W TROF WILL THEN BECOME COLD CORE AND
ACT AS AN ARCTIC CONDUIT ALLOWING A COLD DUMP DOWN THE NORTHERN
PLAINS AND UPPER MIDWEST LATER MONDAY INTO TUE. THE 12Z GFS HAS A
FRIGID H85 MB COLD POOL OF -20 TO -26C BARRELING IT/S WAY DOWN
ACRS MOST OF THE CWA BY 12Z TUE...THE 12Z ECMWF IS ADVERTISING -19 TO
-21C. EVEN WITH MIXING WINDS WHICH WILL BE BRISK IN THIS TYPE OF
CAA UNDER CYCLONIC FLOW...TEMPS BY TUE MORNING MAY GO SUB-ZERO. MAY
BE WIND CHILL ADVISORY CRITERIA ATTAINED IN PORTIONS OF THE AREA LATE
MON NIGHT AND THROUGH MIDDAY TUE. WELL AGAIN...MANY SYSTEMS AND
PHASING PROCESSES TO GO THROUGH TO GET TO THIS EXTENDED PERIOD BUT
WILL START TO TREND TEMPS DOWN. ..12..
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 543 PM CST TUE DEC 3 2013
WARM FRONT EXTENDS BETWEEN KMLI AND KBRL. NORTH OF THE WARM
FRONT WIDESPREAD FOG AND LOW CLOUDS WERE RESULTING IN IFR TO
LIFR CONDITIONS WITH POCKETS OF VLIFR. SOUTH OF THE WARM FRONT
SOME AREAS OF MVFR CONDITIONS WERE FOUND INCLUDING AT KBRL.
OVERALL...CONDITIONS WILL LIKELY BE THE WORST AT KDBQ WHERE LOW
CLOUDS...DENSE FOG AND DRIZZLE TO RESULT IN CONTINUATION OF LIFR
TO VLIFR CONDITIONS THROUGH WED AM. KBRL MAY REMAIN PREDOMINATELY
MVFR UNTIL OVERNIGHT AND KMLI BEING NEAR THE WARM FRONT COULD SEE
SOME IMPROVEMENT TO MVFR THIS EVENING WHILE KCID SHOULD STAY
GENERALLY IFR OR LOWER. ALL SITES SHOULD THEN LOWER ONCE AGAIN
OVERNIGHT TO IFR/LIFR WITH SOME VLIFR IN DENSE FOG... LOW CLOUDS
AND DRIZZLE AND REMAIN SO UNTIL LATER WED AM INTO WED AFTN WHEN A
COLD FRONT APPROACHES. THE COLD FRONT SHOULD DISSIPATE DENSE FOG
BUT MAINTAIN IFR/MVFR CONDITIONS IN LIGHT FOG AND LOW CLOUDS WITH
SOME LIGHT RAIN.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR BENTON-BUCHANAN-
CLINTON-DELAWARE-DUBUQUE-JACKSON-JONES-LINN.
DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR CEDAR-HENRY IA-
IOWA-JEFFERSON-JOHNSON-KEOKUK-LOUISA-MUSCATINE-SCOTT-VAN
BUREN-WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR CARROLL-JO
DAVIESS-STEPHENSON-WHITESIDE.
DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR ROCK ISLAND.
MO...NONE.
&&
$$
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...12
AVIATION...05
AREA FORECAST DISCUSSION
NWS DES MOINES IA
426 PM CST MON DEC 2 2013
.SHORT TERM /TONIGHT/...
ISSUED AT 424 PM CST MON DEC 2 2013
SKIES ARE CLEARING RAPIDLY FROM WEST TO EAST THIS AFTERNOON...BUT
SOME HIGH CLOUDS ARE FILLING BACK IN FROM THE NORTHWEST PER
SATELLITE IMAGERY. AS EXPECTED A WARM FRONT HAS NOSED INTO OUR SOUTH
AND SOUTHWEST AND CONTINUES TO ADVANCE TOWARD CENTRAL
IOWA...BRINGING TEMPERATURES IN THE 50S WITH IT. A QUIET NIGHT IS IN
STORE AS WINDS REMAIN GENERALLY FROM THE SOUTHEAST BUT MID/HIGH
CLOUDS STEADILY THICKEN AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM.
THIS WILL RESULT IN TEMPERATURES STAYING RELATIVELY WARM IN THE MID
TO UPPER 30S IN MOST AREAS OVERNIGHT. FORECAST SOUNDINGS ALSO
INDICATE THAT BY SUNRISE TUESDAY THERE WILL BE QUITE A DEEP
SATURATED LAYER ASSOCIATED WITH THE MID/HIGH CLOUDS...HOWEVER A
POWERFUL NEAR SURFACE DRY LAYER WILL REMAIN IN PLACE. THIS SHOULD
RESULT IN A SCENARIO SIMILAR TO THIS MORNING WHEREBY ANY PRECIP THAT
FORMS LATE TONIGHT WILL FALL IN THE FORM OF VIRGA EVAPORATING BEFORE
IT HITS THE SURFACE...THEN DURING THE DAY TUESDAY PRECIP WILL BE
MORE LIKELY TO REACH THE GROUND AT TIMES. THUS HAVE REMOVED POPS
OVERNIGHT...ALTHOUGH SPRINKLE WORDING MAY NEED TO BE INTRODUCED
LATER FOR THE PRE DAWN HOURS.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 424 PM CST MON DEC 2 2013
MAJOR CHALLENGE IN NEAR TERM IS TRACK OF LOW AND LOCATION/TIMING OF
ASSOCIATED FROPA. THE RAP HAS BEEN INITIALIZING THE BEST ALL
MORNING. BY TUESDAY AFTERNOON...GFS A LITTLE FASTER THAN RAP...AND
NAM A LITTLE SLOWER AND FURTHER SOUTH. ECMWF SEEMS TO SOMEWHAT OF AN
OUTLIER ON TRACK OF LOW. IT SEEMS THE NAM HAS THE BEST HANDLE ON THE
SITUATION...SO PUSHING BACK TIME OF COLD FROPA AND HAVE SUBSEQUENTLY
INCREASED TEMPS OVER GUIDANCE AND PVS FORECAST. ADDITIONALLY...THERE
COULD BE SOME SUNSHINE IN SOUTHWESTERN IOWA AS DRIER AIR BEING
ADCEVTED INTO LOWER LEVELS...WHICH COULD ACTUALLY HELP TEMPS WARM UP
INTO THE MID 60S. DECENT MOISTURE CONVERGENCE AND FORCING ALONG COLD
FRONT. HOWEVER...SOUNDING PROFILES NOT VERY SATURATED IN DMX CWA SO
PRECIP MAY STRUGGLE TO REACH GROUND...THUS LOW QPF FORECAST. STRONG
CAA AND TEMP GRADIENT BEHIND FRONT...SO PRECIP TYPE WILL BE TOUGH TO
PIN DOWN. THE TRANSITION ZONE FROM RANI TO SNOW WILL BE VERY NARROW.
BETTER FORCING TOWARDS MINNESOTA...SO HIGHER POPS TO THE NORTH.
FOR THURSDAY...GFS SOUNDINGS NOW KEEP THE PROFILE VERY SATURATED
DURING THE MORNING. A FEW FLURRIES MAY FALL DURING THE MORNING...BUT
NOT A LOT OF SUPPORT IN THE ATMOSPHERE FOR ANYTHING THAT WOULD
NOTABLY IMPACT THE PUBLIC. ALL MODELS HAVE SUBSIDENCE AND DRY
NORTHWESTERLY FLOW BEING ADVECTED DOWN TO CWA...ESPECIALLY THE
NAM...DURING THE AFTERNOON. THERFORE...THINK CLOUDS SHOULD BEGIN TO
BREAK UP DURING THE DAY. DUE TO LACK OF FORCING HAVE REDUCED POPS
FOR THURSDAY PM.
THURSDAY/S TEMPERATURES SLIGHTLY TRICKY. AS MENTIONED ABOVE...CLOUDS
COVER LIKELY TO BE PRESENT DURING THE MORNING BUT WILL BREAK UP
DURING THE AFTERNOON. ADDITIONALLY...IT APPEARS WIND SPEEDS WILL
REMAIN NEAR THE 10 TO 15KT RANGE. CAA THROUGHOUT THE DAY AS H850
TEMPS WILL START THE DAY AROUND -10C AND END THE DAY NEAR -13C.
THERFORE WENT SEVERAL DEGREES ABOVE GUIDANCE FOR THURSDAY
MORNING...AND WILL INCREASE DAYTIME TEMPERATURES A FEW DEGREES WITH
THE ANTICIPATED SUNSHINE. IN LOCATIONS WHERE SUN CANNOT MAKE IT
THROUGH...TEMPS WILL LIKELY HOLD STEADY OR DECREASE DURING THE DAY.
BY FRIDAY MORNING...PRESSURE GRADIENT STILL PRETTY TIGHT IN ADVANCE
OF APPROACHING HIGH SO WINDS WILL STAY AT LEAST AROUND 10 KTS.
THOUGH NOT A PURE RADIATIONAL COOLING NIGHT...WITH H850 TEMPS
APPROACHING -17C...APPARENT TEMPERATURE AT SURFACE WILL APPROACH
ZERO DEGREES...AND MAY EVEN BE BELOW ZERO IN SOME LOCATIONS. SUNNY
SKIES WILL PREVAIL FOR THE AFTERNOON...BUT HIGHS WILL STRUGGLE TO
MAKE IT OUT OF THE TEENS AS NO WAA EXPECTED.
FOR THE WEEKEND...GFS AND EURO CAME INTO SLIGHTLY BETTER AGREEMENT
WITH THEIR 12Z RUNS. HOWEVER...THERE IS STILL QUITE A BIT OF
DISAGREEMENT. BOTH MODELS DEVELOP A SIZABLE TROUGH THAT PUSHES OFF
THE ROCKIES. THE EURO HAS A MUCH MORE SOUTHERLY TRACK...PUTTING THE
REGION INTO SOUTHWESTERLY FLOW AND BRINGING MUCH GREATER CHANCE FOR
WINTRY PRECIP TO THE AREA. THE GFS ENSEMBLES KEEP THE LOW FURTHER
NORTH...KEPING THE CWA IN WESTERLY TO NORTHWESTERLY FLOW...WHICH
WOULD KEEP COOL...DRY AIR ALOFT AND REDUCE PRECIPITATION CHANCES
FOR DMX.
&&
.AVIATION...02/18Z
ISSUED AT 1126 AM CST MON DEC 2 2013
HIGH CEILINGS...LIGHT RAIN...AND HAZE SHOULD CLEAR OUT FROM WEST
TO EAST IN THE NEXT FEW HOURS WITH VFR CONDITIONS PREVAILING
THEREAFTER. OVERNIGHT...MID/HIGH CLOUDS BETWEEN FL070-FL120 WILL
INCREASE ONCE AGAIN AND BR WILL REDEVELOP ESPECIALLY DURING THE
MORNING HOURS TUES. EXPECT MVFR VSBYS FOR THE MOST PART AND MAYBE
A FEW LOW CLOUDS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LEE
LONG TERM...KOTENBERG
AVIATION...LEE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1112 AM CST MON DEC 2 2013
.UPDATE...
ISSUED AT 1105 AM CST MON DEC 2 2013
A SHORT WAVE MOVING INTO THE AREA COMBINED WITH A WARM FRONT THAT
EXTENDED FROM EASTERN NEB TO CENTRAL MO WAS PRODUCING AN AREA OF
VIRGA/SPRINKLES ACROSS THE DVN CWA. LOW LEVELS OF THE ATMOSPHERE
ARE STILL DRY BUT AS BETTER FORCING ARRIVES THIS AFTERNOON THE LOW
LEVELS SHOULD SATURATE. THE RAPID REFRESH MODEL DEPICTS A BAND OF
LIGHT RAIN MOVING ACROSS THE CWA THIS AFTERNOON INTO THE EVENING.
RAIN AMOUNTS SHOULD BE ONLY A TRACE TO A FEW HUNDREDTHS OF AN INCH.
CURRENT TEMPERATURES RANGE FROM THE MID 30S TO LOWER 40S AND
TEMPERATURES SHOULD RISE ONLY A FEW MORE DEGREES DUE TO EXTENSIVE
CLOUD COVER. HOWEVER...OUR SOUTHERN CWA SHOULD HAVE MORE SUNSHINE
LATER THIS AFTERNOON AS THE WARM FRONT NEARS THAT AREA ALLOWING
TEMPERATURES TO PUSH TO AROUND 50.
UPDATE ISSUED AT 735 AM CST MON DEC 2 2013
MID LEVEL CLOUDS ARE DEVELOPING ACROSS IOWA AND RADAR REFLECTS
THIS WITH AN INCREASE IN OVERALL RETURNS. 12Z DVN SOUNDING HAS A
DRY LAYER FROM ROUGHLY 950-850MB WITH SATURATION OCCURRING ABOVE
THAT. THIS DRY LAYER IS NARROWER THAN WHAT ANY OF THE MODELS
INDICATED IN THEIR RESPECTIVE 6 AND 12 HR FORECASTS.
RECENT TRENDS IN THE RAP MODEL GENERALLY SUPPORTS THE CURRENT
FORECAST OF A BAND OF RAIN DEVELOPING AND MOVING ACROSS THE AREA
TODAY. THE ONLY DIFFERENCE IS THAT THE DEVELOPMENT MAY OCCUR A BIT
LATER THAN WHAT THE CURRENT FORECAST HAS. HOWEVER...THE NARROWER
DRY LAYER IN THE MORNING SOUNDING WOULD TAKE LESS TIME TO
SATURATE SO PRECIPITATION MAY START SOONER THAN WHAT THE RAP IS
SUGGESTING.
&&
.SYNOPSIS...
ISSUED AT 316 AM CST MON DEC 2 2013
06Z SFC ANALYSIS HAS WEAK LOWS NEAR KVIH...KRSL...AND KPIR.
DEVELOPING WARM FRONTS RAN ACROSS NORTHEAST KANSAS THROUGH CENTRAL
MISSOURI AND ANOTHER FROM THE DAKOTAS INTO EASTERN NEBRASKA. DEW
POINTS WERE IN THE 20S ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST
WITHS 30S AND HIGHER FROM THE OHIO VALLEY INTO THE DEEP SOUTH AND
SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST MON DEC 2 2013
CURRENT RADAR TRENDS SHOW PRECIPITATION DECREASING IN COVERAGE AS
THE FIRST ROUND OF FORCING WEAKENS. THUS MAINLY DRY CONDITIONS
SHOULD BE SEEN THROUGH SUNRISE AND THE FIRST PART OF THE MORNING.
FROM MID TO LATE MORNING FORCING BEGINS TO INCREASE AGAIN WITH THE
APPROACH OF THE NEXT UPPER LEVEL DISTURBANCE. THERE IS REASONABLE
AGREEMENT AMONG THE MODELS THAT AS THE FORCING INCREASES...VERY
LIGHT RAIN SHOULD BREAK OUT FROM CENTRAL IOWA INTO THE WESTERN PARTS
OF THE AREA AND INCREASE IN COVERAGE THROUGH MID DAY.
MOISTURE AVAILABILITY IS LIMITED BUT THE FORCING INCREASES FURTHER
DURING THE AFTERNOON. SO...THERE SHOULD BE A BAND OF LIGHT RAIN THAT
WILL MOVE ACROSS THE AREA FROM LATE MORNING THROUGH THE AFTERNOON.
AS THE UPPER LEVEL DISTURBANCE EXITS THE AREA THIS EVENING THE AREAL
COVERAGE OF THE LIGHT RAIN WILL DECREASE THROUGH MID EVENING. THERE
MAY BE A LULL IN PRECIPITATION FROM MID EVENING THROUGH EARLY
MORNING BEFORE THE NEXT UPPER LEVEL DISTURBANCE ARRIVES. THIS
DISTURBANCE SHOULD EITHER ALLOW A MIX TO PERSIST ACROSS THE NORTH OR
DEVELOP A MIX PRIOR TO SUNRISE ON TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 316 AM CST MON DEC 2 2013
A STRONG ARCTIC FRONT WILL SWEEP THROUGH THE MIDWEST...BRINGING A
RETURN TO BRISK COLD TEMPERATURE FOR THE REMAINDER OF THE WEEK.
WHEN THIS BEGINS...THE FROPA...REMAINS A GIANT TROUBLESOME
DIFFERENCE IN THE 00Z GUIDANCE SUITE. THE PERIOD THIS DIFFERENCE WILL
AFFECT IS WEDNESDAY. THERE ARE TWO CAMPS...THE FASTER
NAM/GFS...WHICH MOVE THE FRONT INTO THE CWA TUESDAY NIGHT...AND THE
FAR SLOWER UKMET AND ECMWF WHICH MOVE THE FRONT THROUGH THE CWA
WEDNESDAY AFTERNOON. THIS ROUGHLY 12 HOUR DIFFERENCE CREATES
POTENTIAL FOR A 20 DEGREE BUST ON TEMPS FOR WEDNESDAY. WE COULD
CONCEIVABLY BEGIN THE DAY IN THE MID 30S TO MID 40S...AND FALL LIKE
A ROCK ALL DAY...OR SHOULD THE SLOWER SOLUTIONS WORK OUT...AN
AFTERNOON HIGHS WELL INTO THE 50S COULD BE SEEN IN ILLINOIS. GIVEN
THE POSITIVELY TILTED UPPER TROF...I STILL FEEL THE FASTER SOLUTIONS
ARE NOT OUT OF THE QUESTION. THUS...I WILL GO A BIT MILDER WEDNESDAY
THAN THE FAST/COLD NAM...BUT MUCH COOLER THAN THE SLOW ECMWF. IN
ALL...THIS DAY STILL DOES NOT OFFER MUCH CHANCE FOR SIGNIFICANT
RAIN/SNOW...BUT A SMALL POP FOR 0.01 OR SO REMAINS IN THE FORECAST
WITH THE FRONT.
TEMPERATURES TUESDAY WILL BE QUITE MILD...WARM SECTORED...WITH 40S
NORTH TO MID AND UPPER 50S CENTRAL AND SOUTH. THIS AIR HANGS ON
UNTIL THE FROPA...LEADING TO THE POTENTIAL CHALLENGE OF WEDNESDAYS
HIGHS AND HOURLY TEMPERATURES. BEHIND THE FRONT...TEMPERATURES WILL
CERTAINLY CRASH...TO THE 20S AND TEENS INITIALLY...BUT BY THURSDAY
NIGHT THROUGH THE WEEKEND...LOWS IN THE SINGLE DIGITS ARE CERTAINLY
LIKELY. HIGHS IN THE UPPER TEENS TO LOWER 20S WILL FINISH OUT THE
WEEK. WIND CHILLS OF -10 TO +5 WILL BE FOUND EACH NIGHT FROM
THURSDAY NIGHT THROUGH SATURDAY NIGHT.
LOW POPS ARE RETAINED IN THE SOUTH FOR THE NORTH EDGE OF A POSSIBLE
OVER RUNNING LIGHT SNOW EVENT THURSDAY INTO FRIDAY. OTHERWISE...THE
NEXT MORE LIKELY OVER RUNNING LIGHT SNOW EVENT APPEARS SET FOR
SUNDAY AND MONDAY.
ERVIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1105 AM CST MON DEC 2 2013
VFR/OCNL MVFR CONDS IN BR/AREAS OF -RA THROUGH THIS EVENING. THEN
MVFR/OCNL IFR CIGS/VIS TONIGHT INTO TUESDAY MORNING. SOUTHEAST
WINDS AROUND 10 KNOTS OR LESS THROUGH THIS TAF CYCLE.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...08
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
745 AM CST MON DEC 2 2013
.UPDATE...
ISSUED AT 735 AM CST MON DEC 2 2013
MID LEVEL CLOUDS ARE DEVELOPING ACROSS IOWA AND RADAR REFLECTS
THIS WITH AN INCREASE IN OVERALL RETURNS. 12Z DVN SOUNDING HAS A
DRY LAYER FROM ROUGHLY 950-850MB WITH SATURATION OCCURRING ABOVE
THAT. THIS DRY LAYER IS NARROWER THAN WHAT ANY OF THE MODELS
INDICATED IN THEIR RESPECTIVE 6 AND 12 HR FORECASTS.
RECENT TRENDS IN THE RAP MODEL GENERALLY SUPPORTS THE CURRENT
FORECAST OF A BAND OF RAIN DEVELOPING AND MOVING ACROSS THE AREA
TODAY. THE ONLY DIFFERENCE IS THAT THE DEVELOPMENT MAY OCCUR A BIT
LATER THAN WHAT THE CURRENT FORECAST HAS. HOWEVER...THE NARROWER
DRY LAYER IN THE MORNING SOUNDING WOULD TAKE LESS TIME TO
SATURATE SO PRECIPITATION MAY START SOONER THAN WHAT THE RAP IS
SUGGESTING.
&&
.SYNOPSIS...
ISSUED AT 316 AM CST MON DEC 2 2013
06Z SFC ANALYSIS HAS WEAK LOWS NEAR KVIH...KRSL...AND KPIR.
DEVELOPING WARM FRONTS RAN ACROSS NORTHEAST KANSAS THROUGH CENTRAL
MISSOURI AND ANOTHER FROM THE DAKOTAS INTO EASTERN NEBRASKA. DEW
POINTS WERE IN THE 20S ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST
WITHS 30S AND HIGHER FROM THE OHIO VALLEY INTO THE DEEP SOUTH AND
SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST MON DEC 2 2013
CURRENT RADAR TRENDS SHOW PRECIPITATION DECREASING IN COVERAGE AS
THE FIRST ROUND OF FORCING WEAKENS. THUS MAINLY DRY CONDITIONS
SHOULD BE SEEN THROUGH SUNRISE AND THE FIRST PART OF THE MORNING.
FROM MID TO LATE MORNING FORCING BEGINS TO INCREASE AGAIN WITH THE
APPROACH OF THE NEXT UPPER LEVEL DISTURBANCE. THERE IS REASONABLE
AGREEMENT AMONG THE MODELS THAT AS THE FORCING INCREASES...VERY
LIGHT RAIN SHOULD BREAK OUT FROM CENTRAL IOWA INTO THE WESTERN PARTS
OF THE AREA AND INCREASE IN COVERAGE THROUGH MID DAY.
MOISTURE AVAILABILITY IS LIMITED BUT THE FORCING INCREASES FURTHER
DURING THE AFTERNOON. SO...THERE SHOULD BE A BAND OF LIGHT RAIN THAT
WILL MOVE ACROSS THE AREA FROM LATE MORNING THROUGH THE AFTERNOON.
AS THE UPPER LEVEL DISTURBANCE EXITS THE AREA THIS EVENING THE AREAL
COVERAGE OF THE LIGHT RAIN WILL DECREASE THROUGH MID EVENING. THERE
MAY BE A LULL IN PRECIPITATION FROM MID EVENING THROUGH EARLY
MORNING BEFORE THE NEXT UPPER LEVEL DISTURBANCE ARRIVES. THIS
DISTURBANCE SHOULD EITHER ALLOW A MIX TO PERSIST ACROSS THE NORTH OR
DEVELOP A MIX PRIOR TO SUNRISE ON TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 316 AM CST MON DEC 2 2013
A STRONG ARCTIC FRONT WILL SWEEP THROUGH THE MIDWEST...BRINGING A
RETURN TO BRISK COLD TEMPERATURE FOR THE REMAINDER OF THE WEEK.
WHEN THIS BEGINS...THE FROPA...REMAINS A GIANT TROUBLESOME
DIFFERENCE IN THE 00Z GUIDANCE SUITE. THE PERIOD THIS DIFFERENCE WILL
AFFECT IS WEDNESDAY. THERE ARE TWO CAMPS...THE FASTER
NAM/GFS...WHICH MOVE THE FRONT INTO THE CWA TUESDAY NIGHT...AND THE
FAR SLOWER UKMET AND ECMWF WHICH MOVE THE FRONT THROUGH THE CWA
WEDNESDAY AFTERNOON. THIS ROUGHLY 12 HOUR DIFFERENCE CREATES
POTENTIAL FOR A 20 DEGREE BUST ON TEMPS FOR WEDNESDAY. WE COULD
CONCEIVABLY BEGIN THE DAY IN THE MID 30S TO MID 40S...AND FALL LIKE
A ROCK ALL DAY...OR SHOULD THE SLOWER SOLUTIONS WORK OUT...AN
AFTERNOON HIGHS WELL INTO THE 50S COULD BE SEEN IN ILLINOIS. GIVEN
THE POSITIVELY TILTED UPPER TROF...I STILL FEEL THE FASTER SOLUTIONS
ARE NOT OUT OF THE QUESTION. THUS...I WILL GO A BIT MILDER WEDNESDAY
THAN THE FAST/COLD NAM...BUT MUCH COOLER THAN THE SLOW ECMWF. IN
ALL...THIS DAY STILL DOES NOT OFFER MUCH CHANCE FOR SIGNIFICANT
RAIN/SNOW...BUT A SMALL POP FOR 0.01 OR SO REMAINS IN THE FORECAST
WITH THE FRONT.
TEMPERATURES TUESDAY WILL BE QUITE MILD...WARM SECTORED...WITH 40S
NORTH TO MID AND UPPER 50S CENTRAL AND SOUTH. THIS AIR HANGS ON
UNTIL THE FROPA...LEADING TO THE POTENTIAL CHALLENGE OF WEDNESDAYS
HIGHS AND HOURLY TEMPERATURES. BEHIND THE FRONT...TEMPERATURES WILL
CERTAINLY CRASH...TO THE 20S AND TEENS INITIALLY...BUT BY THURSDAY
NIGHT THROUGH THE WEEKEND...LOWS IN THE SINGLE DIGITS ARE CERTAINLY
LIKELY. HIGHS IN THE UPPER TEENS TO LOWER 20S WILL FINISH OUT THE
WEEK. WIND CHILLS OF -10 TO +5 WILL BE FOUND EACH NIGHT FROM
THURSDAY NIGHT THROUGH SATURDAY NIGHT.
LOW POPS ARE RETAINED IN THE SOUTH FOR THE NORTH EDGE OF A POSSIBLE
OVER RUNNING LIGHT SNOW EVENT THURSDAY INTO FRIDAY. OTHERWISE...THE
NEXT MORE LIKELY OVER RUNNING LIGHT SNOW EVENT APPEARS SET FOR
SUNDAY AND MONDAY.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 537 AM CST MON DEC 2 2013
MVFR VSBYS MAY BRIEFLY IMPROVE TO VFR PRIOR TO 18Z/02. HOWEVER...
AN APPROACHING DISTURBANCE WILL DEVELOP WIDESPREAD MVFR CONDITIONS
AROUND 18Z/02 WITH RAIN. THE POSSIBILITY DOES EXIST THAT BRIEF
PERIODS OF IFR CONDITIONS MAY DEVELOP IN THE RAIN PRIOR TO 00Z/03.
AFTER 00Z/03 MVFR/IFR CONDITIONS WILL PERSIST WITH SOME
IMPROVEMENT TO VFR ACROSS SOUTHEAST IOWA FOLLOWING THE FRONTAL
PASSAGE.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...08
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
624 PM CST Tue Dec 3 2013
...Updated aviation section...
.SYNOPSIS...
ISSUED AT 1106 AM CST TUE DEC 3 2013
At 12z Tuesday a -35c 500mb low was located over Idaho/western
Montana. A +100kt 300mb jet streak was located in the based of
this upper low and extended from northern Nevada into southern
Wyoming. 700 mb level difluent flow appears to be located across
eastern Wyoming. This was located near the left exit region of
the 300mb jet. Across the Central Plains earlier this morning the
850mb temperatures ranged from +10C at North Platte to +15c at
Amarillo. Dodge City this morning had a 850mb temperature of +13c.
A surface cold front was located across Nebraska at 12z Tuesday.
North of this surface cold front low clouds, gusty north winds and
light snow/fog were observed from the surface observations across
eastern Wyoming and northwest Nebraska. Surface temperatures under
the status were mainly in the 20s. 850mb temperatures north of
this front varied from -9c at South Dakota to -13c at Glasgow MT.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 222 PM CST TUE DEC 3 2013
12z NAM and GFS along with the latest HRRR and RAP were all in
decent agreement with a cold front surging south across western
Kansas during the overnight hours. Based on 18z verification
between the models and the surface observations the 2m
temperatures across Nebraska from NAM and HRRR were within 3
degrees of the actual temperature, and both of these models were
close with the surface front location. 12z NAM model soundings
across Nebraska also appeared to be picking up on the status
behind this front as well. As a result will stay close to the NAM
and HRRR on timing of the wind shift overnight along with the
magnitude of the cold air advection that will be developing behind
this front overnight as low clouds thicken across western Kansas.
Given the current temperatures behind this front in northern
Nebraska, status and cold air advection that is forecast to spread
into western Kansas later tonight have decided to stay close the
previous forecast which was also similar to the latest MET
guidance. Gusty north winds at 20 to 30 mph are also expected to
develop for several hours behind this front later tonight based
given the tight surface pressure gradient and 925-850mb winds of
25 to 35 knots. These gusty winds by daybreak will easily result
in wind chill values in the single digits by early Wednesday
morning. Isentropic lift/warm air advection along with a deepening
moist layer across portions of north central Kansas approaches a
depth favorable for some very light precipitation, however at
this time have decided not to introduce any type of very light
precipitation east of 183.
On Wednesday the status will slowly erode during the afternoon
and cold air advection continues in the 900mb to 850mb layer. Based
on the 18z Wednesday and 00z Thursday 850mb temperatures from the
NAM and GFS will undercut the MET/MAV guidance for highs.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 132 PM CST TUE DEC 3 2013
Wednesday night/Thursday:
The 12Z ECMWF, NAM, and GEM were indicating the potential for
some snow Wednesday night but mainly into Thursday as an 145 kt
250 mbjet streak moves across the region. This will create an
ageostrophic response (i.e. acceleration) and cause some synoptic
lift across the forecast area of responsibility. On top of that,
the models indicate low level isentropic lift on top of the cold
airmass. The GFS is the oddball out and was ignored as it did not
match ensemble mean nor the aforementioned consensus in the
deterministic runs. Will have to watch for a sneaky snow advisory
snow amount being met. One fly in the ointment is that the low
levels are very dry (as expected with an Arctic intrusion), so
this could reduce probabilities for more significant precipitation
measurement. Of course, not ready to buy into the thermodynamic
profiles (particularly the NAM) this far out, but did trend with
higher pops, qpf, and lower temperatures. If a snow pack does come
into fruition, the minimums into Friday morning will have to be
watched as they could bottom into negative territory. Otherwise,
midweek will be cold and have gone with bias corrected mos
guidance.
Friday and beyond:
Friday through Saturday will feature a precipitation free forecast as
the region will be between synoptic systems. The next chance of precipitation
in the form of snow will be on Sunday as another trof digs across the
central Rockies and eventually ejects out across the prairies. It is
too early to hammer out details this far out and have stuck with the
weighted blend solution. Temperatures will continue to remain below
normal.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 618 PM CST TUE DEC 3 2013
VFR conditions this evening will transition to MVFR conditions
around midnight as stratus clouds AOA012 develop across the TAF
sites. This is due to a cold front moving through the area and the
air behind this front becoming saturated. This front has already
moved through HYS and is expected to move through DDC and GCK in
the next couple of hours. Light and variable winds will be observed
ahead of this front with northerly winds at 15 to 20 knots behind
this front. Gusty winds up to 30 knots will also be possible.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 21 28 10 13 / 0 0 10 50
GCK 21 26 11 12 / 0 0 30 50
EHA 21 29 7 13 / 0 10 30 50
LBL 23 29 13 13 / 0 0 10 50
HYS 21 28 9 17 / 0 0 20 10
P28 29 35 14 19 / 0 0 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burgert
LONG TERM...Sugden
AVIATION...Hovorka_42
AREA FORECAST DISCUSSION
NWS GOODLAND KS
504 PM MST TUE DEC 3 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 157 PM MST TUE DEC 3 2013
AS OF 3 PM CST...2 PM MST...SKIES ACROSS THE TRI-STATE AREA RANGED
FROM PARTLY CLOUDY TO OVERCAST AS HIGH CIRRUS CONTINUES TO PASS
OVER. TEMPERATURES REACHED THE LOW TO MID 60S ACROSS THE AREA WITH
THE EXCEPTION OF SOUTHWEST NEBRASKA. A BACK DOOR COLD FRONT HAS
MOVED IN FROM THE NORTHEAST...KEEPING THINGS ACROSS THE NORTHEASTERN
THIRD OF THE FORECAST AREA COOLER. WINDS HAVE BEEN FROM THE SOUTH
AHEAD OF THE COLD FRONT AND NORTHEAST BEHIND THE BACKDOOR FRONT. THE
MAIN COLD FRONT WAS FINALLY BEGINNING TO MAKE ITS SURGE INTO
NORTHEAST COLORADO. THE FRONT WAS BLOCKED BY A STRONG LEE TROUGH
CENTERED BETWEEN DENVER AND LIMON. THIS LEE TROUGH IS NOW STARTING
TO MOVE SOUTHEAST FROM LATEST RAP MSL ANALYSIS...ALLOWING THE MAIN
COLD FRONT TO SURGE SOUTH.
FOR THIS AFTERNOON AND TONIGHT...THE STRONG ARCTIC FRONT WILL MAKE
ITS PRESENCE FELT AS IT MOVES SOUTH. TEMPERATURES DROP RAPIDLY BY
THE FRONT AS SEEN BY THE 15 TO 20 DEGREE DROPS IN ONE HOUR AT YUMA
AND AKRON COLORADO. IMMEDIATELY BEHIND THE FRONT...GUSTY NORTH WINDS
ARE EXPECTED. WINDS NEAR WIND ADVISORY CRITERIA HAVE NOT BEEN
OBSERVED AND MODELS HAVE BACKED OFF ON WIND SPEEDS FROM YESTERDAYS
RUNS. THERE COULD BE SOME GUSTS THAT APPROACH WIND ADVISORY CRITERIA
BUT THIS SHOULD NOT BE WIDESPREAD NOR PERSISTENT. LOW TEMPERATURES
TONIGHT SHOULD BE ABLE TO DROP INTO THE LOW 10S TO LOW 20S EVEN WITH
DENSE CLOUD COVER. FOR PRECIPITATION CHANCES...MOST OF THE
PRECIPITATION WILL LIKELY HOLD OFF UNTIL AFTER 00Z WITH CHANCES
GRADUALLY INCREASING THROUGHOUT THE NIGHT. MODELS INDICATE THAT THE
ATMOSPHERE GRADUALLY SATURATES THROUGH THE NIGHT...ALLOWING SNOW TO
BEGIN FALLING THIS EVENING OR EARLY TOMORROW MORNING. SOUTHEAST
PORTIONS OF THE FORECAST AREA SHOULD MISS OUT ON THE PRECIPITATION
FOR THE MOST PART BUT COULD SEEM SOME FLURRIES. ACCUMULATIONS WILL
BE LIGHT AS ALL MODELS SHOW LIGHT QPF WITH HEAVIER AMOUNTS WEST
WHERE TERRAIN EFFECTS AND LIFT ARE STRONGER.
FOR TOMORROW...COLD WEATHER WILL CONTINUE WITH HIGH TEMPERATURES LESS
THAN 10 DEGREES WARMER THAN LOW TEMPERATURES TONIGHT. HIGHS ARE ONLY
ADVERTISED TO BE IN THE LOW 10S OVER NORTHEAST COLORADO TO THE MID
20S OUT NEAR HILL CITY. THIS COULD BE GENEROUS CONSIDERING THAT
DENSE CLOUD COVER AND NORTH WINDS SHOULD PERSIST. CHANCES FOR LIGHT
SNOW CONTINUE IN THE MORNING HOURS BEFORE CHANCES DECREASE ACROSS
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. CHANCES SHOULD CONTINUE
OVER EAST COLORADO WITH A SLIGHT UPSLOPE COMPONENT AND A BETTER
ATMOSPHERIC MOISTURE PROFILE. AGAIN...ONLY LIGHT ACCUMULATIONS ARE
EXPECTED WITH LITTLE IMPACT TO TRAVEL. ANOTHER THING TO NOTE ABOUT
TOMORROW IS THAT WITH THE NORTH WINDS AND COLD TEMPERATURES...WIND
CHILLS SHOULD REMAIN IN THE SINGLE DIGITS ABOVE ZERO THROUGHOUT THE
DAY WITH BELOW ZERO WIND CHILLS POSSIBLE IN EAST COLORADO. NEEDLESS
TO SAY...TOMORROW WILL BE MUCH COLDER WITH HIGH TEMPERATURES ON THE
ORDER OF 20 TO 45 DEGREES COOLER DEPENDING ON THE LOCATION.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 157 PM MST TUE DEC 3 2013
COLD AIR WILL BE THOROUGHLY ENTRENCHED ACROSS THE CENTRAL HIGH
PLAINS REGION AND IS EXPECTED TO REMAIN IN PLACE THROUGH THE
FORECAST PERIOD. FLURRIES TO LIGHT SNOW WILL CONTINUE ACROSS
PORTIONS OF THE FORECAST AREA THROUGH THURSDAY NIGHT AS THE MAIN
UPPER TROUGH AND A COUPLE OF PRECEDING SHORT WAVE TROUGHS LIFT
OUT OF THE SOUTHWEST UNITED STATES AND ACROSS THE HIGH PLAINS REGION.
FRIDAY AND FRIDAY NIGHT WILL BE DRY AND COLD WITH HIGH PRESSURE IN
PLACE AT THE SURFACE IN THE WAKE OF THE UPPER TROUGH AS IT MOVES
QUICKLY TO THE EAST. LATE SATURDAY THROUGH SUNDAY BRINGS ANOTHER
CHANCE OF LIGHT SNOW AS THE NEXT UPPER LOW CENTER MOVES OUT OF THE
SOUTHWEST UNITED STATES AND INTO THE CENTRAL UNITED STATES.
MONDAY THROUGH TUESDAY WILL BE DRY AGAIN IN THE WAKE OF THE SECOND
UPPER SYSTEM WHILE COLD HIGH PRESSURE REMAINS IN PLACE...KEEPING
TEMPERATURES ABOUT 20 DEGREES COLDER THAN AVERAGE THROUGH THE
LONG TERM PORTION OF THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 440 PM MST TUE DEC 3 2013
CEILINGS ARE ALREADY LOWERING AT KMCK AND THE LOW STRATUS IS
OBSERVED ENTERING KGLD. LOW CEILINGS AND THE CHANCE FOR SOME VERY
LIGHT SNOW OR FLURRIES WILL OCCUR BEHIND A COLD FRONT TONIGHT INTO
TOMORROW MORNING. LOW STRATUS SHOULD LINGER THROUGH TOMORROW AS
THE WEATHER SYSTEM SLOWLY MOVES EAST-SOUTHEAST.
FOR KGLD...MVFR CONDITIONS TO START THE TAF PERIOD WITH OVC015
CEILINGS. CEILINGS WILL PROGRESSIVELY LOWER TO IFR AROUND 06Z
WITH LIGHT SNOW POSSIBLE OVER THE TERMINAL. ONLY REDUCED
VISIBILITY TO 5SM FOR NOW...SINCE SNOW SHOULD BE VERY LIGHT.
CEILINGS IMPROVE TO VFR BY TOMORROW AFTERNOON. NORTH-NORTHEAST
WINDS WILL CONTINUE THROUGHOUT THE TAF PERIOD WITH GUSTS AROUND 25
TO 30 KTS.
FOR KMCK...IFR CONDTIONS TO START THE TAF PERIOD WITH OVC008
CEILINGS. IFR CONDITIONS WILL CONTINUE OVERNIGHT WITH THE CHANCE
FOR LIGHT SNOW OVER THE TERMINAL. REDUCED VISIBILITY TO 4SM WITH
THE LIGHT SNOW. CEILINGS SHOULD IMPROVE TO MVFR LATE TOMORROW
MORNING INTO AFTERNOON. NORTH-NORTHEAST WINDS WILL CONTINUE
THROUGHOUT THE TAF PERIOD WITH GUSTS AROUND 20 TO 30 KTS.
WINDS AND CEILINGS WILL CONTINUE TO BE MONITORED AND AMMENDMENTS
WILL BE MADE WHEN NECESSARY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...LOCKHART
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS JACKSON KY
105 AM EST MON DEC 2 2013
.UPDATE...
ISSUED AT 105 AM EST MON DEC 2 2013
UPDATED HOURLY TEMPERATURES AND DEWPOINTS. UNLESS CEILINGS CAN COME
DOWN A BIT...DRIZZLE IS LOOKING LESS LIKELY THE REST OF THE NIGHT.
DEW POINT DEPRESSIONS ARE STILL PLENTY HIGH AND HARD TO SEE THAT
CHANGING OVER THE NEXT 3 TO 4 HOURS. THUS...WILL REMOVE THE DRIZZLE
AND STAY WITH A DRY FORECAST THROUGH TOMORROW.
UPDATE ISSUED AT 929 PM EST SUN DEC 1 2013
CLOUDY SKIES WILL PREVAIL DURING THE OVERNIGHT. DRIZZLE IS LOOKING
LESS LIKELY FOR LATE TONIGHT AND EARLY MONDAY MORNING...BUT WILL LEAVE
IT IN THE FORECAST FOR THE SAKE OF CONTINUITY AND CONSISTENCY. HAVE
UPDATED HOURLY NDFD AND WEB FORECASTS BASED ON LATEST TRENDS...AND
MADE A FEW MINOR TEMPERATURE ADJUSTMENTS FOR OVERNIGHT LOWS. NEEDED
TO LOWER MINIMUMS IN SOME VALLEY LOCATIONS WHERE TEMPERATURES ONLY
REACHED THE LOWER 40S ON SUNDAY. THE MESONET AT QUICKSAND IS PROBABLY
THE EXTREME EXAMPLE OF THIS WHERE THE AFTERNOON HIGH WAS ONLY 41 AND
THE 02Z TEMPERATURE WAS 37. THIS IS CONTRASTED TO THE JACKSON
ASOS...ONLY 4 MILES AWAY...WHERE THE HIGH WAS 47 AND THE 02Z TEMPERATURE
WAS 47. NO UPDATE NEEDED FOR THE ZFP AT THIS TIME.
UPDATE ISSUED AT 636 PM EST SUN DEC 1 2013
LOW CLOUDS CONTINUE TO HOLD ACROSS THE AREA...AND WILL LIMIT
TEMPERATURE FALLS THIS EVENING. THE PREVIOUS FORECAST HAD THIS WELL
HANDLED. NDFD WAS UPDATED FOR LATEST HOURLY TRENDS BUT THIS RESULTED
IN ONLY MINOR CHANGES TO THE HOURLY NDFD FORECASTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 338 PM EST SUN DEC 1 2013
A BAND OF LOW CLOUDS REMAINS ACROSS THE REGION IN ADVANCE OF A WEAK
COLD FRONT THAT IS BEGINNING TO SLOW DOWN AND STALL OUT. SOME OF
THESE HAVE ERODED A BIT FROM THE SOUTH OR SOUTHEAST AND NORTHWEST
THROUGHOUT THE DAY. THIS HAS LED TO THE COLDEST TEMPERATURES ON
AVERAGE BETWEEN THE HAL ROGERS PARKWAY AND KY HIGHWAY 80 CORRIDOR AND
INTERSTATE 64 CORRIDOR. SOME OF THE DEEPER SHELTERED VALLEYS NEVER
REALLY MIXED OUT AND TEMPERATURES THERE ARE IN THE LOW TO MID 40S
ATTM. OTHERWISE TEMPS WERE NEAR 50 ACROSS MUCH OF THE SOUTHERN CWA
AND HAD NEARED 50 NORTH OF THE INTERSTATE 64 CORRIDOR.
A WEAK DISTURBANCE IS EXPECTED TO MAINLY PASS TO OUR SOUTH LATER
TONIGHT INTO MONDAY MORNING WHILE A MORE NORTHERN SHORTWAVE WILL
PASS TO THE NORTH OF EASTERN KY ON MONDAY AFTERNOON AND EVENING. THIS
WILL LEAD TO A BRIEF DEVELOPMENT OF A SOUTHEASTERN TROUGH BY MONDAY.
THIS TROUGH WILL MOVE ON OFF TO THE EAST WITH SOME WEAK RIDGING
PASSING THROUGH OVER THE SOUTHEASTERN US AND TN VALLEY FOR MON NIGHT
INTO TUE. AT THE END OF THE PERIOD...A TROUGH IS ANTICIPATED TO
EXTEND FROM CENTRAL CANADA INTO THE NORTHERN PLAINS AND THEN
SOUTHWEST INTO THE ROCKIES AND CALIFORNIA WITH MORE OR LESS ZONAL
FLOW IN THE EASTERN CONUS.
AS AT THE SFC...THE BOUNDARY TO OUR NORTHWEST SHOULD STALL NEAR THE
OH RIVER TONIGHT AND INTO MONDAY BEFORE RETURNING NORTH AS A WARM
FRONT LATER ON MONDAY INTO TUESDAY. MODELS INDICATE A GENERAL
GRADUAL INCREASE IN MOISTURE BELOW THE CURRENT CLOUD LAYER
TONIGHT...BUT MEAGER OMEGA AT BEST. UP UNTIL TODAY AT LEAST...MODELS
SEEM TO HAVE BEEN TOO AGGRESSIVE INCREASING LOW LEVEL MOISTURE.
HOWEVER...DEWPOINTS HAVE CREPT UP INTO THE MID TO UPPER 30S IN
WESTERN AND CENTRAL KY AND MIDDLE AND WESTERN TN. THIS LEADS TO
UNCERTAINTY AS TO WHETHER OR NOT THE STRATOCU DECK COULD LOWER LATER
TONIGHT INTO EARLY ON MONDAY AND WHETHER OR NOT THERE COULD BE SOME
PATCHY DRIZZLE AT THAT TIME. THE 12Z NAM AND 12Z GFS HAD SOME LIGHT
SPOTTY QPF WITH THIS LATE TONIGHT OR MONDAY. THE 18Z HRRR ALSO HAD
SOME LIGHT SPOTTY QPF LATER TONIGHT. THE 15Z SREF POPS ARE LOW AND
HAVE TRENDED DOWN SINCE 24 HOURS AGO. OPTED TO GO WITH A 10 POP FOR
PATCHY DRIZZLE IN ALL BUT THE FAR SOUTHEAST LATE TONIGHT AND INTO
MONDAY MORNING AND THEN STAYED CLOSE TO THE PREVIOUS FORECAST FOR
LATER ON MONDAY INTO MONDAY EVENING WITH A SLIGHT CHANCE IN THE FAR
NORTH. THIS LED TO BETTER ISC CONSISTENCY.
WITH LOW CLOUDS EXPECTED FOR MOST...IF NOT ALL OF THE NIGHT...MIN T
TONIGHT WILL BE CONSIDERABLY MILDER IN DEEPER SHELTERED VALLEY
LOCATIONS COMPARED TO RECENT NIGHTS. MIN T SHOULD REMAIN ABOVE
FREEZING IN ALL LOCATIONS. SOME THINNING OF THE CLOUDS IS ANTICIPATED
ON MON AFTERNOON AND TEMPS SHOULD GENERALLY REACH THE LOW TO MID 50S.
MIN T ON MON NIGHT IS A BIT MORE UNCERTAIN...AS SOME OF THE GUIDANCE
SUGGESTS THERE COULD BE WINDOW OF TIME WHERE CLOUDS COULD BE THIN
ENOUGH OR POSSIBLY BRIEFLY CLEAR AND ALLOW A RIDGE/VALLEY TEMP SPLIT
TO DEVELOP IN SOUTHEASTERN VALLEYS. NEVERTHELESS...MIN T ON MON
NIGHT SHOULD ALSO BE ABOVE NORMAL.
OTHERWISE...THE BULK OF THE PERIOD SHOULD BE DRY WITH SOUTHERLY TO
SOUTHWESTERLY LOW LEVEL FLOW INCREASING LATE IN THE PERIOD IN
ADVANCE OF A DEVELOPING MUCH MORE SIGNIFICANT SYSTEM THAT WILL IMPACT
THE REGION FROM MIDWEEK ON. THE 12Z AND 18Z NAM AS WELL AS THE 12Z
ECMWF SUGGEST A STRAY SHOWER MIGHT BE POSSIBLE OVER THE SOUTHWEST ON
TUE IN THE WARM SECTOR...BUT THE OTHER GUIDANCE WAS MORE SUPPORTIVE
OF JUST A CONSIDERABLE AMOUNT OF CLOUDS FROM TIME TO TIME. MUCH OF
THE RECENT MAX T GUIDANCE SUGGESTS TUE WILL BE RATHER MILD...ABOVE
NORMAL AND IF CLOUDS WERE TO THIN FOR A WHILE 60 DEGREES WOULD BE
REACHABLE IN MANY LOCATIONS. TUE TEMPS WERE RAISED A COUPLE OF DEGREES
ON AVERAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 318 PM EST SUN DEC 1 2013
THE UPPER AIR PATTERN OVER THE EASTERN THIRD OF THE CONUS WILL
FEATURE A LARGE STORM SYSTEM TAKING SHAPE OVER THE NORTHERN PLAINS
TO BEGIN THE PERIOD. BOTH THE GFS AND ECMWF MODELS HAVE VERY SIMILAR
SOLUTIONS REGARDING THE STRENGTH AND EVOLUTION OF THIS SYSTEM. THIS
SYSTEM IS PROGGED TO MOVE ACROSS THE UPPER GREAT LAKES REGION
WEDNESDAY NIGHT AND THURSDAY. AS IT DOES SO...A SURFACE COLD FRONT
WILL MOVE INTO THE AREA FROM THE NORTHWEST...AND EVENTUALLY STALL
ACROSS THE OHIO AND UPPER TENNESSEE VALLEY REGIONS FROM THURSDAY
NIGHT THROUGH SUNDAY. WEAK WAVES OF LOW PRESSURE MOVING ALONG THIS
BOUNDARY...COUPLED WITH A STRONG FEED OF MOISTURE OFF THE GULF OF
MEXICO...WILL COMBINE TO BRING A PROLONGED PERIOD OF PRECIPITATION
TO EASTERN KENTUCKY. THE FIRST COUPLE OF DAYS OF THE PERIOD WILL
FEATURE PERSISTENT SOUTHERLY FLOW OFF THE GULF...WITH HIGH
TEMPERATURES IN THE LOWER 60S ON WEDNESDAY...AND IN THE MID TO UPPER
50S ON THURSDAY. THE WARM MOIST AIR OFF THE GULF WILL BRING AN
INCREASE IN CLOUD COVER AS THE FRONT APPROACHES FROM THE WEST. THE
FIRST PRECIPITATION IS EXPECTED TO MOVE INTO THE NORTHWEST PART OF
THE AREA EARLY WEDNESDAY MORNING...AS WARM MOIST AIR BEGINS TO
INTERACT WITH THE LEADING EDGE OF THE APPROACHING COLD FRONT. AS THE
FRONT CONTINUES TO MOVE SLOWLY EASTWARD...PRECIPITATION WILL
INCREASE IN COVERAGE. THE FIRST GOOD CHANCE OF RAIN SHOULD ARRIVE
WEDNESDAY NIGHT...AS THE FRONT MOVES SOUTH OF THE OHIO RIVER. THE
BEST CHANCE FOR PRECIPITATION WILL OCCUR FROM EARLY THURSDAY MORNING
THROUGH EARLY SATURDAY MORNING...AS THE FRONT STALLS OVER THE
REGION. PRECIPITATION CHANCES SHOULD REMAIN IN THE FORECAST THROUGH
SATURDAY NIGHT...AS YET ANOTHER WEAK WAVE OF LOW PRESSURE MOVES
ALONG THE SLUGGISH FRONTAL BOUNDARY.
TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP PRECIPITATION IN THE
FORM OF RAIN FROM WEDNESDAY THROUGH FRIDAY AFTERNOON. WITH THE FRONT
STALLED OVER THE AREA...AND WITH A STEADY FEED OF MOISTURE OFF THE
GULF OF MEXICO INTERACTING WITH THE FRONT...THERE WILL THE POTENTIAL
FOR LOCALLY HEAVY RAINFALL. ONCE THE FRONT MOVES THROUGH THE
AREA...AND WINDS SHIFT TO THE NORTHWEST AND EVENTUALLY NORTH...SNOW
MAY BEGIN TO MIX WITH THE RAIN...BEGINNING IN THE FAR NORTHWESTERN
PORTION OF THE FORECAST AREA. THE LATEST TIME HEIGHT CROSS SECTIONS
AND SOUNDINGS SUPPORT A MIX OF RAIN AND SNOW FRIDAY NIGHT THROUGH
THE END OF THE DAY ON SATURDAY. IF THE LATEST MODEL DATA HOLDS
TRUE...THERE COULD BE ENOUGH COLD AIR IN PLACE ACROSS THE AREA FROM
EARLY SATURDAY NIGHT THROUGH EARLY SUNDAY AFTERNOON FOR
PRECIPITATION TO CHANGE OVER TO ALL SNOW. IF THIS TURNS OUT TO BE
THE CASE...WE COULD SEE SOME LIGHT SNOW ACCUMULATIONS SATURDAY NIGHT
AND SUNDAY ACROSS EASTERN KENTUCKY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 105 AM EST MON DEC 2 2013
BORDERLINE...MVFR/VFR CEILINGS WILL LINGER THROUGH DAYBREAK...BEFORE
LIFTING SOLIDLY TO ALL VFR BY 10 AM. THE LOW CLOUDS WILL ATTEMPT TO
BREAK UP LATE IN THE DAY. OVERALL...LIGHT AND VARIABLE WINDS WILL BE
SEEN THROUGH THE TAF FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
848 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL GRADUALLY MOVE EAST OF THE GULF OF MAINE
TODAY. LOW PRESSURE WILL DEVELOP ALONG THE MID ATLANTIC COASTLINE
ON TUESDAY... BRINGING A CHANCE OF PRECIPITATION MAINLY TO EASTERN
SECTIONS. BRIEF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER LOW
PRESSURE SYSTEM PASSES NORTH ON THURSDAY WITH AN OCCLUDED FRONT
CROSSING NEW ENGLAND. HIGH PRESSURE OVER THE NORTHERN PLAINS
WILL THEN SLOWLY BUILD TOWARDS THE EAST THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
JUST A QUICK UPDATE TO EXTEND THE WINTER WEATHER ADVISORY AND THE
FREEZING RAIN ADVISORY UNTIL 10 AM. TEMPERATURES ARE STILL IN THE
30-32 DEGREE RANGE BUT SHOULD RISE ABOVE FREEZING AROUND 10 AM.
&&
UPDATE...PCPN IS BEGINNING TO WEAKEN ALONG THE MIDCOAST...LINING
UP WELL WITH PREVIOUS RUNS OF THE HRRR. HAVE DECIDED TO EXTEND THE
WINTER WX ADVISORY FOR THE CAPITAL REGION AND SRN
FRANKLIN/SOMERSET COUNTIES UNTIL 9 AM. TEMPS REMAIN AOB
FREEZING...WITH PCPN EXPECTED TO LINGER THERE INTO THE MID
MORNING. AN ADDITIONAL INCH OR SO OF ACCUMS AND A TRACE OF ICE
WILL BE POSSIBLE. ALSO HAVE ADDED INTERIOR WRN ME S OF THE MTNS TO
A FZRA ADVISORY FOR WIDESPREAD AREAS OF FZDZ. SECONDARY ROADS ARE
BECOMING QUITE ICY...AS THE DZ IS MUCH MORE EFFICIENT AT ACCRETION
AT THESE MARGINAL TEMPS.
PREVIOUS DISCUSSION...SFC TROF AND ASSOCIATED WEAK AREA OF LOW
PRES OFF OF CAPE COD IS CONTINUING TO PUMP PCPN INTO THE MIDCOAST.
THAT LOW PRES HAS ALLOWED WINDS TO BACK AROUND TO A MORE NLY
DIRECTION...EFFECTIVELY LOCKING THE COLDER AIR IN PLACE AT THE
SFC. WHILE TEMPS ALONG THE COAST ARE IN THE MID 30S...JUST INLAND
THEY ARE AOB FREEZING. ALOFT TEMPS ARE SLOWLY CREEPING UP...WITH
HI-RES MODEL GUIDANCE LIKE THE HRRR AND RAP SUGGESTING H9 AND H8
TEMPS RISING ABOVE FREEZING BY 12Z FOR MUCH OF THE COAST AND
COASTAL PLAIN. THAT MEANS THE CAPITAL REGION WHERE IT HAS BEEN
SNFL MUCH OF THE NIGHT WILL SEE A GRADUAL TRANSITION TOWARDS A MIX
WITH RA AND FZRA. GUIDANCE HAS H9 TEMPS WARMING MORE QUICKLY THAN
H8...SO GIVEN THAT LACK OF A DEEP COLD LAYER NEAR THE SFC I HAVE
REMOVED MUCH OF THE PL FROM THE FORECAST. KGYX RADAR ALSO
INDICATES THE 0.5 DEG CORRELATION COEFFICIENT INFERRED MELTING
LAYER GRADUALLY INCREASING IN RANGE. THIS SUPPORTS THE NWP
FORECAST WARMING ALOFT...AND EXPECT THAT MIXING WILL BEGIN AROUND
KAUG SOONER RATHER THAN LATER.
ATTM ADVISORY IS SET TO EXPIRE AT 11Z. WILL CONTINUE IT UNTIL THAT
TIME AS THERE REMAINS SN...FZRA...AND FZDZ ACROSS THE ADVISORY
AREA. HOWEVER...WRF AND HRRR GUIDANCE CONTINUES PCPN UNTIL NEARLY
NOON ACROSS PARTS OF THE MIDCOAST. AN EXTENSION MAY BE NECESSARY
IF TEMPS TO DO NOT WARM ANY FURTHER AT THE SFC.
OTHERWISE...EVENTUALLY DIURNAL HEATING WINS OUT AND PCPN NEAR THE
COAST WILL FLIP TO ALL RA IF IT HASN/T ENDED ALREADY BY THAT TIME.
SFC TROF WILL LINGER NEARBY...AS IT SLOWLY DRIFTS TOWARDS DOWNEAST
ME. THIS COULD MEAN SCT/ISOLD SHWRS CONTINUE MUCH OF THE DAY FROM
JACKMAN TO KRKD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
SFC TROF IS SLOW TO WEAKEN AND LIFT NEWD TONIGHT. IF IT LINGERS
OVER DOWNEAST ME SOME SCT TO ISOLD SHWRS ARE POSSIBLE THRU THE
NIGHT. PCPN WILL BE LIGHT...AND SHOULD STAY IN THE FORM OR RA OR
SN. ONE CONCERN COULD BE IF THE COLUMN DRIES OUT. THIS COULD BRING
A PERIOD OF DZ/FZDZ RATHER THAN SHWRS. THIS COULD BRING ANOTHER
ROUND OF SLICK CONDITIONS FOR THE INTERIOR MIDCOAST.
BY TUE MORNING COASTAL LOW PRES WILL BE ORGANIZING S OF SRN NEW
ENGLAND. WITH A LACK OF DOWNSTREAM RIDGING AND DELAYED ARRIVAL OF
NRN STREAM S/WV TROF THERE IS NOT MUCH TO KEEP THIS SYSTEM FROM
SLIDING OUT TO SEA. LATE INTERACTION WITH THE NRN STREAM WILL
SWING THE LOW PRES TOWARDS THE CANADIAN MARITIMES BY LATE TUE
NIGHT. IT IS AS IT DOES SO THAT PCPN SHIELD MAY BRUSH PORTIONS OF
THE MIDCOAST. HAVE KEPT LIKELY POP OFFSHORE FOR NOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE GRADUALLY INTENSIFIES EAST OF THE GULF OF MAINE
TUESDAY NIGHT. 00Z MODEL SUITE IN GOOD AGREEMENT WITH THE TRACK OF
THIS SYSTEM...KEEPING MUCH OF THE PRECIPITATION EAST OF OUR
REGION...OVER DOWNEAST MAINE.
A WEAK RIDGE OF HIGH PRESSURE CROSSES THE REGION WEDNESDAY
MORNING...BEFORE CLOUDS SPILL OVER THE RIDGE IN THE AFTERNOON.
PLENTY OF WARM AIR WILL ARRIVE WITH THE APPROACH OF AN OCCLUDED
FRONT...BRINGING SHOWERS OR PATCHY FREEZING RAIN OVER INTERIOR
SECTIONS ON WEDNESDAY NIGHT. TEMPERATURES ALOFT WILL MAKE IT
DIFFICULT FOR ANY SNOW...HOWEVER SURFACE TEMPERATURES MAY FALL TO
BELOW THE FREEZING LEVEL OVER NORTHERN AREAS DURING THE OVERNIGHT
HOURS.
HIGH PRESSURE WILL GRADUALLY BUILD EAST FROM THE NORTHERN PLAINS
DURING THE PERIOD THURSDAY AND INTO THE WEEKEND. THIS WILL BRING
COOLER TEMPERATURES TO THE REGION...HOWEVER NOT A DIRECT BLOW OF
ARCTIC AIR TO NEW ENGLAND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
SHORT TERM...AREAS OF IFR OR LOWER ALONG THE COAST AND INTERIOR
WILL BE VERY SLOW TO SCATTER OUT AND LIFT TODAY. EXPECTING MVFR
AND VFR CONDITIONS TO PROGRESS SW TO NE ALONG THE COAST THRU THE
AFTERNOON. INVOF KAUG...FZRA WILL BE POSSIBLE THIS MORNING...AS
WARMTH ALOFT PUSHES NWD. THIS AFTERNOON CLOUDS FROM THE SW WILL
PUSH ACROSS THE MTNS...WITH KHIE SEEING A PERIOD OF MVFR
CONDITIONS. WILL HAVE TO WATCH FOR MVFR OR LOWER CONDITIONS TO
WORK BACK INTO COASTAL TERMINALS AGAIN TONIGHT...AS ONSHORE FLOW
DEVELOPS AHEAD OF NEXT OCEAN LOW PRES.
LONG TERM...AREAS OF MVFR CONDITIONS ARE POSSIBLE TUESDAY NIGHT
OVER DOWNEAST MAINE. AREAS OF MVFR CONDITIONS ARE ALSO POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF AN
OCCLUDED FRONT.
&&
.MARINE...
SHORT TERM...WEAK LOW PRES IN THE GULF OF ME WILL KEEP WINDS
GUSTING AT OR JUST BELOW 25 KTS EARLY THIS MORNING. HOWEVER...THIS
NE FLOW WILL ALSO KEEP SEAS ABOVE 5 FT INTO THE
AFTERNOON...ESPECIALLY N OF PORT CLYDE. WILL KEEP SCA GOING FOR
THE OUTER WATERS UNTIL SEAS BEGIN TO SUBSIDE.
LONG TERM...THERE MAY BE BORDERLINE SCA CONDITIONS OVER EASTERN
SECTIONS WITH THE PASSAGE OF AN OFFSHORE SYSTEM TUESDAY NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MEZ013-014-021-022.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR MEZ012-
018>020.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ150-
152.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
619 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL GRADUALLY MOVE EAST OF THE GULF OF MAINE TODAY.
LOW PRESSURE WILL DEVELOP ALONG THE MID ATLANTIC COASTLINE ON TUESDAY...
BRINGING A CHANCE OF PRECIPITATION MAINLY TO EASTERN SECTIONS.
BRIEF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER LOW PRESSURE
SYSTEM PASSES NORTH ON THURSDAY WITH AN OCCLUDED FRONT CROSSING
NEW ENGLAND. HIGH PRESSURE OVER THE NORTHERN PLAINS WILL THEN
SLOWLY BUILD TOWARDS THE EAST THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...PCPN IS BEGINNING TO WEAKEN ALONG THE MIDCOAST...LINING
UP WELL WITH PREVIOUS RUNS OF THE HRRR. HAVE DECIDED TO EXTEND THE
WINTER WX ADVISORY FOR THE CAPITAL REGION AND SRN
FRANKLIN/SOMERSET COUNTIES UNTIL 9 AM. TEMPS REMAIN AOB
FREEZING...WITH PCPN EXPECTED TO LINGER THERE INTO THE MID
MORNING. AN ADDITIONAL INCH OR SO OF ACCUMS AND A TRACE OF ICE
WILL BE POSSIBLE. ALSO HAVE ADDED INTERIOR WRN ME S OF THE MTNS TO
A FZRA ADVISORY FOR WIDESPREAD AREAS OF FZDZ. SECONDARY ROADS ARE
BECOMING QUITE ICY...AS THE DZ IS MUCH MORE EFFICIENT AT ACCRETION
AT THESE MARGINAL TEMPS.
PREVIOUS DISCUSSION...SFC TROF AND ASSOCIATED WEAK AREA OF LOW
PRES OFF OF CAPE COD IS CONTINUING TO PUMP PCPN INTO THE MIDCOAST.
THAT LOW PRES HAS ALLOWED WINDS TO BACK AROUND TO A MORE NLY
DIRECTION...EFFECTIVELY LOCKING THE COLDER AIR IN PLACE AT THE
SFC. WHILE TEMPS ALONG THE COAST ARE IN THE MID 30S...JUST INLAND
THEY ARE AOB FREEZING. ALOFT TEMPS ARE SLOWLY CREEPING UP...WITH
HI-RES MODEL GUIDANCE LIKE THE HRRR AND RAP SUGGESTING H9 AND H8
TEMPS RISING ABOVE FREEZING BY 12Z FOR MUCH OF THE COAST AND
COASTAL PLAIN. THAT MEANS THE CAPITAL REGION WHERE IT HAS BEEN
SNFL MUCH OF THE NIGHT WILL SEE A GRADUAL TRANSITION TOWARDS A MIX
WITH RA AND FZRA. GUIDANCE HAS H9 TEMPS WARMING MORE QUICKLY THAN
H8...SO GIVEN THAT LACK OF A DEEP COLD LAYER NEAR THE SFC I HAVE
REMOVED MUCH OF THE PL FROM THE FORECAST. KGYX RADAR ALSO
INDICATES THE 0.5 DEG CORRELATION COEFFICIENT INFERRED MELTING
LAYER GRADUALLY INCREASING IN RANGE. THIS SUPPORTS THE NWP
FORECAST WARMING ALOFT...AND EXPECT THAT MIXING WILL BEGIN AROUND
KAUG SOONER RATHER THAN LATER.
ATTM ADVISORY IS SET TO EXPIRE AT 11Z. WILL CONTINUE IT UNTIL THAT
TIME AS THERE REMAINS SN...FZRA...AND FZDZ ACROSS THE ADVISORY
AREA. HOWEVER...WRF AND HRRR GUIDANCE CONTINUES PCPN UNTIL NEARLY
NOON ACROSS PARTS OF THE MIDCOAST. AN EXTENSION MAY BE NECESSARY
IF TEMPS TO DO NOT WARM ANY FURTHER AT THE SFC.
OTHERWISE...EVENTUALLY DIURNAL HEATING WINS OUT AND PCPN NEAR THE
COAST WILL FLIP TO ALL RA IF IT HASN/T ENDED ALREADY BY THAT TIME.
SFC TROF WILL LINGER NEARBY...AS IT SLOWLY DRIFTS TOWARDS DOWNEAST
ME. THIS COULD MEAN SCT/ISOLD SHWRS CONTINUE MUCH OF THE DAY FROM
JACKMAN TO KRKD.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
SFC TROF IS SLOW TO WEAKEN AND LIFT NEWD TONIGHT. IF IT LINGERS
OVER DOWNEAST ME SOME SCT TO ISOLD SHWRS ARE POSSIBLE THRU THE
NIGHT. PCPN WILL BE LIGHT...AND SHOULD STAY IN THE FORM OR RA OR
SN. ONE CONCERN COULD BE IF THE COLUMN DRIES OUT. THIS COULD BRING
A PERIOD OF DZ/FZDZ RATHER THAN SHWRS. THIS COULD BRING ANOTHER
ROUND OF SLICK CONDITIONS FOR THE INTERIOR MIDCOAST.
BY TUE MORNING COASTAL LOW PRES WILL BE ORGANIZING S OF SRN NEW
ENGLAND. WITH A LACK OF DOWNSTREAM RIDGING AND DELAYED ARRIVAL OF
NRN STREAM S/WV TROF THERE IS NOT MUCH TO KEEP THIS SYSTEM FROM
SLIDING OUT TO SEA. LATE INTERACTION WITH THE NRN STREAM WILL
SWING THE LOW PRES TOWARDS THE CANADIAN MARITIMES BY LATE TUE
NIGHT. IT IS AS IT DOES SO THAT PCPN SHIELD MAY BRUSH PORTIONS OF
THE MIDCOAST. HAVE KEPT LIKELY POP OFFSHORE FOR NOW.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
LOW PRESSURE GRADUALLY INTENSIFIES EAST OF THE GULF OF MAINE
TUESDAY NIGHT. 00Z MODEL SUITE IN GOOD AGREEMENT WITH THE TRACK OF
THIS SYSTEM...KEEPING MUCH OF THE PRECIPITATION EAST OF OUR
REGION...OVER DOWNEAST MAINE.
A WEAK RIDGE OF HIGH PRESSURE CROSSES THE REGION WEDNESDAY
MORNING...BEFORE CLOUDS SPILL OVER THE RIDGE IN THE AFTERNOON.
PLENTY OF WARM AIR WILL ARRIVE WITH THE APPROACH OF AN OCCLUDED
FRONT...BRINGING SHOWERS OR PATCHY FREEZING RAIN OVER INTERIOR
SECTIONS ON WEDNESDAY NIGHT. TEMPERATURES ALOFT WILL MAKE IT
DIFFICULT FOR ANY SNOW...HOWEVER SURFACE TEMPERATURES MAY FALL TO
BELOW THE FREEZING LEVEL OVER NORTHERN AREAS DURING THE OVERNIGHT HOURS.
HIGH PRESSURE WILL GRADUALLY BUILD EAST FROM THE NORTHERN PLAINS
DURING THE PERIOD THURSDAY AND INTO THE WEEKEND. THIS WILL BRING
COOLER TEMPERATURES TO THE REGION...HOWEVER NOT A DIRECT BLOW OF
ARCTIC AIR TO NEW ENGLAND.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
SHORT TERM...AREAS OF IFR OR LOWER ALONG THE COAST AND INTERIOR
WILL BE VERY SLOW TO SCATTER OUT AND LIFT TODAY. EXPECTING MVFR
AND VFR CONDITIONS TO PROGRESS SW TO NE ALONG THE COAST THRU THE
AFTERNOON. INVOF KAUG...FZRA WILL BE POSSIBLE THIS MORNING...AS
WARMTH ALOFT PUSHES NWD. THIS AFTERNOON CLOUDS FROM THE SW WILL
PUSH ACROSS THE MTNS...WITH KHIE SEEING A PERIOD OF MVFR
CONDITIONS. WILL HAVE TO WATCH FOR MVFR OR LOWER CONDITIONS TO
WORK BACK INTO COASTAL TERMINALS AGAIN TONIGHT...AS ONSHORE FLOW
DEVELOPS AHEAD OF NEXT OCEAN LOW PRES.
LONG TERM...AREAS OF MVFR CONDITIONS ARE POSSIBLE TUESDAY NIGHT
OVER DOWNEAST MAINE. AREAS OF MVFR CONDITIONS ARE ALSO POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF AN
OCCLUDED FRONT.
&&
.MARINE...
SHORT TERM...WEAK LOW PRES IN THE GULF OF ME WILL KEEP WINDS
GUSTING AT OR JUST BELOW 25 KTS EARLY THIS MORNING. HOWEVER...THIS
NE FLOW WILL ALSO KEEP SEAS ABOVE 5 FT INTO THE
AFTERNOON...ESPECIALLY N OF PORT CLYDE. WILL KEEP SCA GOING FOR
THE OUTER WATERS UNTIL SEAS BEGIN TO SUBSIDE.
LONG TERM...THERE MAY BE BORDERLINE SCA CONDITIONS OVER EASTERN
SECTIONS WITH THE PASSAGE OF AN OFFSHORE SYSTEM TUESDAY NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MEZ013-
014-021-022.
FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR MEZ012-
018>020.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR ANZ150-
152.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS CARIBOU ME
602 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE EAST OF THE REGION TODAY. ANOTHER LOW
WILL TRACK EAST OF THE REGION TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
UPDATED POPS TO GO NEAR 100 PERCENT THIS MORNING BASED ON CURRENT
RADAR IMAGERY. ALSO TWEAKED HOURLY TEMPERATURE GRIDS.
A WEAK AREA OF LOW PRESSURE WILL CONTINUE TO MOVE EAST OF
THE GULF OF MAINE TODAY. CURRENT RADAR IMAGERY WAS SHOWING
PRECIPITATION...MAINLY IN THE FORM OF SNOW CONTINUING ACROSS MUCH
OF CENTRAL AND DOWNEAST MAINE...ALTHOUGH COULDNT RULE OUT SOME
PATCHY FREEZING RAIN ACROSS PORTIONS OF INTERIOR DOWN EAST THROUGH
EARLY THIS MORNING. LATEST HRRR SHOWS PRECIPITATION CONTINUING
INTO MID MORNING AND WITH TEMPERATURES NOT EXPECTED TO BUDGE TOO
MUCH DECIDED TO EXTEND THE WINTER WEATHER ADVISORY UNTIL 11 AM.
THE HIGHEST SNOW TOTALS WILL BE ACROSS CENTRAL PENOBSCOT AND
WASHINGTON COUNTIES. HOWEVER...WE LOWERED TOTAL SNOWFALL
ACCUMULATIONS BASED ON CALLS TO LOCAL/FED LAW ENFORCEMENT AGENCIES
WHICH WERE INDICATING SNOWFALL AMOUNTS BELOW OUR CURRENT
FORECASTED AMOUNTS AS OF EARLY THIS MORNING. THE PRECIPITATION
ACROSS DOWNEAST AREAS SHOULD DIMINISH LATER THIS MORNING AND WITH
TEMPERATURES THIS AFTERNOON EXPECTED TO RISE ABOVE FREEZING ANY
LINGERING PRECIPITATION THIS AFTERNOON DOWNEAST WILL BE IN THE
FORM OF RAIN. ACROSS NORTHERN AREAS EXPECT LIGHT SNOW TO CONTINUE
INTO THIS AFTERNOON. ACROSS NORTHERN AREAS EXPECT ACCUMULATIONS
TODAY TO RANGE FROM 1 TO 3 INCHES. HIGHS TODAY WILL RANGE FROM THE
LOWER 30S NORTH AND MID TO UPPER 30S DOWNEAST.
TONIGHT WILL BE CLOUDY WITH A CONTINUED CHANCE FOR SOME LIGHT SNOW
MAINLY ACROSS NORTHERN AREAS AND THE CHANCE FOR SOME LIGHT RAIN
SHOWERS ACROSS CENTRAL AND DOWNEAST. THERE COULD EVEN BE A LITTLE
LIGHT FREEZING RAIN OR DRIZZLE LATE TONIGHT ACROSS NORTHERN AREAS.
LITTLE TEMPERATURE CHANGE IS EXPECTED TONIGHT WITH LOWS IN THE UPPER
20S TO AROUND 30 NORTH AND LOW TO MID 30S DOWNEAST.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
LINGERING PRECIP PSBL ACROSS MAINLY NRN AREAS TUE AM AS INITIAL
WEAK LOW PRES AFFECTING THE REGION TODAY DISSIPATES WHILE
STRONGER LOW PRES WELL OFF THE MID ATLC STATES TUE AM BEGINS TO
TRACK NEWD TOWARD SRN NS... LATEST MODEL CONSENSUS CONTS TO
INDICATE THAT THIS SYSTEM WILL PASS WELL E OF THE AREA (ACROSS ERN
NS WED AM) W/ JUST A GLANCING BLOW ACROSS FAR ERN AND SERN AREAS
LATE TUE INTO TUE NGT. WILL BRING HIGHEST POPS (LIKELY) INTO OUR
SERN ZNS TUE AM INTO TUE EVE W/ CHC POPS CENTRAL AND N AND NE W/
SLGT CHC TO NIL POPS FAR W AND NW... LACK OF ANY REAL COLD AIR
ACROSS THE AREA ALSO SUGGESTS PRECIP ACROSS OUR SERN TO E CENTRAL
AREAS MAY BE RAIN OR A MX OF RAIN AND WET SNOW. IN ANY CASE...ATTM
DOES NOT APPEAR THAT THIS WILL BE A SIGNIFICANT WNTR SYSTEM FOR
OUR AREA... ANY PRECIP ASSOCIATED W/ THIS SYSTEM IS EXPECTED TO
EXIT THE AREA ERLY WED W/ A RIDGE OF HIGH PRES THEN FCST TO BUILD
ACROSS OUR FA WED. THIS WILL RESULT IN DRY COND W/ TEMPS A LITTLE
ABV SEASONAL NORMS W/ HIGHS RANGING FROM THE MID 30S N TO AROUND
40 S... &&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RIDGE OF HIGH PRES ACROSS THE FA WED EVE IS EXPECTED TO SHIFT E OF
THE REGION WED NGT AS DEEP LOW PRES OVR THE WRN GRT LKS LIFTS
NEWRD AND SWEEPS AN OCLD FRONT EWRD ACROSS THE NERN STATES AND OUR
AREA BY ERLY THU PER THE FASTER GFS AND BY LATE THU EVE PER THE
SLOWER ECMWF. THIS FRONTAL BNDRY IS THEN FCST TO BECOME NRLY
STATIONARY FROM THE SRN GULF OF MAINE SWWRD ACROSS THE SERN STATES
AND INTO THE WRN GULF OF MEX. GUIDANCE THEN SUGGESTS WAVES OF SFC
LOW PRES LIFTING NEWRD UP ALONG THIS FRONTAL BNDRY MAY BRUSH
MAINLY OUR SRN AREAS FRI INTO SAT W/ THE THREAT OF SOME PRECIP W/
DRIER AND COLDER AIR FINALLY OVERSPREADING THE ENTIRE REGION LATER
SAT THRU SUN... TEMPS WILL REMAIN ABV SEASONAL NORMS AT THE START
OF THE LONG TERM PD THEN GRADUAL TREND TO SEASONAL AND THEN TO BLO
SEASONAL NORMS BY SUN. POPULATED OUR LONG TERM GRIDS W/ THE
SUPER BLEND CONSENSUS AND MADE MINIMAL ADJUSTMENTS...&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
NEAR TERM: WIDESPREAD IFR/MVFR CONDITIONS ARE EXPECTED AT THE TERMINALS
TODAY IN LOW CIGS AND LGT SNOW NORTH AND LGT SNOW/RAIN KBGR/KBHB
TERMINALS. THESE FLIGHT CONDITIONS WILL PERSIST THROUGH TONIGHT.
SHORT TERM: MVFR TO PSBL IFR TUE INTO TUE NGT AS STRONG LOW PRES
TRACKS E OF THE REGION AND BRUSHES THE REGION W/ SOME PRECIP. VFR
CONDS EXPECTED WED INTO THU W/ ANOTHER ROUND OF MVFR TO IFR
EXPECTED LATER THU INTO FRI AS A COMPLEX FRONTAL SYSTEM CROSSES
THE REGION.
&&
.MARINE...
NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
TONIGHT. VISIBILITY WILL BE REDUCED AT TIMES TO 1 TO 3 NM IN LIGHT
RAIN THROUGH TONIGHT.
SHORT TERM: SCA CONDS ARE EXPECTED TO DVLP LATER TUE AND CONT THRU
MUCH OF WED AS DEEP LOW PRES TRACKS E OF THE WATERS...
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
MEZ005-006-011-015>017-032.
MARINE...NONE.
&&
$$
NEAR TERM...DUDA
SHORT TERM...KHW
LONG TERM...KHW
AVIATION...DUDA/KHW
MARINE...DUDA/KHW
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
555 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL GRADUALLY MOVE EAST OF THE GULF OF MAINE TODAY.
LOW PRESSURE WILL DEVELOP ALONG THE MID ATLANTIC COASTLINE ON TUESDAY...
BRINGING A CHANCE OF PRECIPITATION MAINLY TO EASTERN SECTIONS.
BRIEF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER LOW PRESSURE
SYSTEM PASSES NORTH ON THURSDAY WITH AN OCCLUDED FRONT CROSSING
NEW ENGLAND. HIGH PRESSURE OVER THE NORTHERN PLAINS WILL THEN
SLOWLY BUILD TOWARDS THE EAST THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...PCPN IS BEGINNING TO WEAKEN ALONG THE MIDCOAST...LINING
UP WELL WITH PREVIOUS RUNS OF THE HRRR. HAVE DECIDED TO EXTEND THE
WINTER WX ADVISORY FOR THE CAPITAL REGION AND SRN
FRANKLIN/SOMERSET COUNTIES UNTIL 9 AM. TEMPS REMAIN AOB
FREEZING...WITH PCPN EXPECTED TO LINGER THERE INTO THE MID
MORNING. AN ADDITIONAL INCH OR SO OF ACCUMS AND A TRACE OF ICE
WILL BE POSSIBLE.
PREVIOUS DISCUSSION...SFC TROF AND ASSOCIATED WEAK AREA OF LOW
PRES OFF OF CAPE COD IS CONTINUING TO PUMP PCPN INTO THE MIDCOAST.
THAT LOW PRES HAS ALLOWED WINDS TO BACK AROUND TO A MORE NLY
DIRECTION...EFFECTIVELY LOCKING THE COLDER AIR IN PLACE AT THE
SFC. WHILE TEMPS ALONG THE COAST ARE IN THE MID 30S...JUST INLAND
THEY ARE AOB FREEZING. ALOFT TEMPS ARE SLOWLY CREEPING UP...WITH
HI-RES MODEL GUIDANCE LIKE THE HRRR AND RAP SUGGESTING H9 AND H8
TEMPS RISING ABOVE FREEZING BY 12Z FOR MUCH OF THE COAST AND
COASTAL PLAIN. THAT MEANS THE CAPITAL REGION WHERE IT HAS BEEN
SNFL MUCH OF THE NIGHT WILL SEE A GRADUAL TRANSITION TOWARDS A MIX
WITH RA AND FZRA. GUIDANCE HAS H9 TEMPS WARMING MORE QUICKLY THAN
H8...SO GIVEN THAT LACK OF A DEEP COLD LAYER NEAR THE SFC I HAVE
REMOVED MUCH OF THE PL FROM THE FORECAST. KGYX RADAR ALSO
INDICATES THE 0.5 DEG CORRELATION COEFFICIENT INFERRED MELTING
LAYER GRADUALLY INCREASING IN RANGE. THIS SUPPORTS THE NWP
FORECAST WARMING ALOFT...AND EXPECT THAT MIXING WILL BEGIN AROUND
KAUG SOONER RATHER THAN LATER.
ATTM ADVISORY IS SET TO EXPIRE AT 11Z. WILL CONTINUE IT UNTIL THAT
TIME AS THERE REMAINS SN...FZRA...AND FZDZ ACROSS THE ADVISORY
AREA. HOWEVER...WRF AND HRRR GUIDANCE CONTINUES PCPN UNTIL NEARLY
NOON ACROSS PARTS OF THE MIDCOAST. AN EXTENSION MAY BE NECESSARY
IF TEMPS TO DO NOT WARM ANY FURTHER AT THE SFC.
OTHERWISE...EVENTUALLY DIURNAL HEATING WINS OUT AND PCPN NEAR THE
COAST WILL FLIP TO ALL RA IF IT HASN/T ENDED ALREADY BY THAT TIME.
SFC TROF WILL LINGER NEARBY...AS IT SLOWLY DRIFTS TOWARDS DOWNEAST
ME. THIS COULD MEAN SCT/ISOLD SHWRS CONTINUE MUCH OF THE DAY FROM
JACKMAN TO KRKD.
&&
.SHORT TERM /TUESDAY/...
SFC TROF IS SLOW TO WEAKEN AND LIFT NEWD TONIGHT. IF IT LINGERS
OVER DOWNEAST ME SOME SCT TO ISOLD SHWRS ARE POSSIBLE THRU THE
NIGHT. PCPN WILL BE LIGHT...AND SHOULD STAY IN THE FORM OR RA OR
SN. ONE CONCERN COULD BE IF THE COLUMN DRIES OUT. THIS COULD BRING
A PERIOD OF DZ/FZDZ RATHER THAN SHWRS. THIS COULD BRING ANOTHER
ROUND OF SLICK CONDITIONS FOR THE INTERIOR MIDCOAST.
BY TUE MORNING COASTAL LOW PRES WILL BE ORGANIZING S OF SRN NEW
ENGLAND. WITH A LACK OF DOWNSTREAM RIDGING AND DELAYED ARRIVAL OF
NRN STREAM S/WV TROF THERE IS NOT MUCH TO KEEP THIS SYSTEM FROM
SLIDING OUT TO SEA. LATE INTERACTION WITH THE NRN STREAM WILL
SWING THE LOW PRES TOWARDS THE CANADIAN MARITIMES BY LATE TUE
NIGHT. IT IS AS IT DOES SO THAT PCPN SHIELD MAY BRUSH PORTIONS OF
THE MIDCOAST. HAVE KEPT LIKELY POP OFFSHORE FOR NOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE GRADUALLY INTENSIFIES EAST OF THE GULF OF MAINE
TUESDAY NIGHT. 00Z MODEL SUITE IN GOOD AGREEMENT WITH THE TRACK OF
THIS SYSTEM...KEEPING MUCH OF THE PRECIPITATION EAST OF OUR
REGION...OVER DOWNEAST MAINE.
A WEAK RIDGE OF HIGH PRESSURE CROSSES THE REGION WEDNESDAY
MORNING...BEFORE CLOUDS SPILL OVER THE RIDGE IN THE AFTERNOON.
PLENTY OF WARM AIR WILL ARRIVE WITH THE APPROACH OF AN OCCLUDED
FRONT...BRINGING SHOWERS OR PATCHY FREEZING RAIN OVER INTERIOR
SECTIONS ON WEDNESDAY NIGHT. TEMPERATURES ALOFT WILL MAKE IT
DIFFICULT FOR ANY SNOW...HOWEVER SURFACE TEMPERATURES MAY FALL TO
BELOW THE FREEZING LEVEL OVER NORTHERN AREAS DURING THE OVERNIGHT HOURS.
HIGH PRESSURE WILL GRADUALLY BUILD EAST FROM THE NORTHERN PLAINS
DURING THE PERIOD THURSDAY AND INTO THE WEEKEND. THIS WILL BRING
COOLER TEMPERATURES TO THE REGION...HOWEVER NOT A DIRECT BLOW OF
ARCTIC AIR TO NEW ENGLAND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHORT TERM...AREAS OF IFR OR LOWER ALONG THE COAST AND INTERIOR
WILL BE VERY SLOW TO SCATTER OUT AND LIFT TODAY. EXPECTING MVFR
AND VFR CONDITIONS TO PROGRESS SW TO NE ALONG THE COAST THRU THE
AFTERNOON. INVOF KAUG...FZRA WILL BE POSSIBLE THIS MORNING...AS
WARMTH ALOFT PUSHES NWD. THIS AFTERNOON CLOUDS FROM THE SW WILL
PUSH ACROSS THE MTNS...WITH KHIE SEEING A PERIOD OF MVFR
CONDITIONS. WILL HAVE TO WATCH FOR MVFR OR LOWER CONDITIONS TO
WORK BACK INTO COASTAL TERMINALS AGAIN TONIGHT...AS ONSHORE FLOW
DEVELOPS AHEAD OF NEXT OCEAN LOW PRES.
LONG TERM...AREAS OF MVFR CONDITIONS ARE POSSIBLE TUESDAY NIGHT
OVER DOWNEAST MAINE. AREAS OF MVFR CONDITIONS ARE ALSO POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF AN
OCCLUDED FRONT.
&&
.MARINE...
SHORT TERM...WEAK LOW PRES IN THE GULF OF ME WILL KEEP WINDS
GUSTING AT OR JUST BELOW 25 KTS EARLY THIS MORNING. HOWEVER...THIS
NE FLOW WILL ALSO KEEP SEAS ABOVE 5 FT INTO THE
AFTERNOON...ESPECIALLY N OF PORT CLYDE. WILL KEEP SCA GOING FOR
THE OUTER WATERS UNTIL SEAS BEGIN TO SUBSIDE.
LONG TERM...THERE MAY BE BORDERLINE SCA CONDITIONS OVER EASTERN
SECTIONS WITH THE PASSAGE OF AN OFFSHORE SYSTEM TUESDAY NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MEZ013-
014-021-022.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR ANZ150-
152.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS CARIBOU ME
358 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE EAST OF THE REGION TODAY. ANOTHER LOW
WILL TRACK EAST OF THE REGION TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEAK AREA OF LOW PRESSURE WILL CONTINUE TO MOVE EAST OF THE GULF
OF MAINE TODAY. CURRENT RADAR IMAGERY WAS SHOWING
PRECIPITATION...MAINLY IN THE FORM OF SNOW CONTINUING ACROSS MUCH OF
CENTRAL AND DOWNEAST MAINE...ALTHOUGH COULDNT RULE OUT SOME PATCHY
FREEZING RAIN ACROSS PORTIONS OF INTERIOR DOWN EAST THROUGH EARLY
THIS MORNING. LATEST HRRR SHOWS PRECIPITATION CONTINUING INTO MID
MORNING AND WITH TEMPERATURES NOT EXPECTED TO BUDGE TOO MUCH DECIDED
TO EXTEND THE WINTER WEATHER ADVISORY UNTIL 11 AM. THE HIGHEST SNOW
TOTALS WILL BE ACROSS CENTRAL PENOBSCOT AND WASHINGTON COUNTIES.
HOWEVER...WE LOWERED TOTAL SNOWFALL ACCUMULATIONS BASED ON CALLS TO
LOCAL/FED LAW ENFORCEMENT AGENCIES WHICH WERE INDICATING SNOWFALL
AMOUNTS BELOW OUR CURRENT FORECASTED AMOUNTS AS OF EARLY THIS
MORNING. THE PRECIPITATION ACROSS DOWNEAST AREAS SHOULD DIMINISH
LATER THIS MORNING AND WITH TEMPERATURES THIS AFTERNOON EXPECTED TO
RISE ABOVE FREEZING ANY LINGERING PRECIPITATION THIS AFTERNOON
DOWNEAST WILL BE IN THE FORM OF RAIN. ACROSS NORTHERN AREAS EXPECT
LIGHT SNOW TO CONTINUE INTO THIS AFTERNOON. ACROSS NORTHERN AREAS
EXPECT ACCUMULATIONS TODAY TO RANGE FROM 1 TO 3 INCHES. HIGHS
TODAY WILL RANGE FROM THE LOWER 30S NORTH AND MID TO UPPER 30S
DOWNEAST.
TONIGHT WILL BE CLOUDY WITH A CONTINUED CHANCE FOR SOME LIGHT SNOW
MAINLY ACROSS NORTHERN AREAS AND THE CHANCE FOR SOME LIGHT RAIN
SHOWERS ACROSS CENTRAL AND DOWNEAST. THERE COULD EVEN BE A LITTLE
LIGHT FREEZING RAIN OR DRIZZLE LATE TONIGHT ACROSS NORTHERN AREAS.
LITTLE TEMPERATURE CHANGE IS EXPECTED TONIGHT WITH LOWS IN THE UPPER
20S TO AROUND 30 NORTH AND LOW TO MID 30S DOWNEAST.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
LINGERING PRECIP PSBL ACROSS MAINLY NRN AREAS TUE AM AS INITIAL
WEAK LOW PRES AFFECTING THE REGION TODAY DISSIPATES WHILE
STRONGER LOW PRES WELL OFF THE MID ATLC STATES TUE AM BEGINS TO
TRACK NEWD TOWARD SRN NS... LATEST MODEL CONSENSUS CONTS TO
INDICATE THAT THIS SYSTEM WILL PASS WELL E OF THE AREA (ACROSS ERN
NS WED AM) W/ JUST A GLANCING BLOW ACROSS FAR ERN AND SERN AREAS
LATE TUE INTO TUE NGT. WILL BRING HIGHEST POPS (LIKELY) INTO OUR
SERN ZNS TUE AM INTO TUE EVE W/ CHC POPS CENTRAL AND N AND NE W/
SLGT CHC TO NIL POPS FAR W AND NW... LACK OF ANY REAL COLD AIR
ACROSS THE AREA ALSO SUGGESTS PRECIP ACROSS OUR SERN TO E CENTRAL
AREAS MAY BE RAIN OR A MX OF RAIN AND WET SNOW. IN ANY CASE...ATTM
DOES NOT APPEAR THAT THIS WILL BE A SIGNIFICANT WNTR SYSTEM FOR
OUR AREA... ANY PRECIP ASSOCIATED W/ THIS SYSTEM IS EXPECTED TO
EXIT THE AREA ERLY WED W/ A RIDGE OF HIGH PRES THEN FCST TO BUILD
ACROSS OUR FA WED. THIS WILL RESULT IN DRY COND W/ TEMPS A LITTLE
ABV SEASONAL NORMS W/ HIGHS RANGING FROM THE MID 30S N TO AROUND
40 S... &&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RIDGE OF HIGH PRES ACROSS THE FA WED EVE IS EXPECTED TO SHIFT E OF
THE REGION WED NGT AS DEEP LOW PRES OVR THE WRN GRT LKS LIFTS
NEWRD AND SWEEPS AN OCLD FRONT EWRD ACROSS THE NERN STATES AND OUR
AREA BY ERLY THU PER THE FASTER GFS AND BY LATE THU EVE PER THE
SLOWER ECMWF. THIS FRONTAL BNDRY IS THEN FCST TO BECOME NRLY
STATIONARY FROM THE SRN GULF OF MAINE SWWRD ACROSS THE SERN STATES
AND INTO THE WRN GULF OF MEX. GUIDANCE THEN SUGGESTS WAVES OF SFC
LOW PRES LIFTING NEWRD UP ALONG THIS FRONTAL BNDRY MAY BRUSH
MAINLY OUR SRN AREAS FRI INTO SAT W/ THE THREAT OF SOME PRECIP W/
DRIER AND COLDER AIR FINALLY OVERSPREADING THE ENTIRE REGION LATER
SAT THRU SUN... TEMPS WILL REMAIN ABV SEASONAL NORMS AT THE START
OF THE LONG TERM PD THEN GRADUAL TREND TO SEASONAL AND THEN TO BLO
SEASONAL NORMS BY SUN. POPULATED OUR LONG TERM GRIDS W/ THE
SUPER BLEND CONSENSUS AND MADE MINIMAL ADJUSTMENTS...&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
NEAR TERM: WIDESPREAD IFR/MVFR CONDITIONS ARE EXPECTED AT THE TERMINALS
TODAY IN LOW CIGS AND LGT SNOW NORTH AND LGT SNOW/RAIN KBGR/KBHB
TERMINALS. THESE FLIGHT CONDITIONS WILL PERSIST THROUGH TONIGHT.
SHORT TERM: MVFR TO PSBL IFR TUE INTO TUE NGT AS STRONG LOW PRES
TRACKS E OF THE REGION AND BRUSHES THE REGION W/ SOME PRECIP. VFR
CONDS EXPECTED WED INTO THU W/ ANOTHER ROUND OF MVFR TO IFR
EXPECTED LATER THU INTO FRI AS A COMPLEX FRONTAL SYSTEM CROSSES
THE REGION.
&&
.MARINE...
NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
TONIGHT. VISIBILITY WILL BE REDUCED AT TIMES TO 1 TO 3 NM IN LIGHT
RAIN THROUGH TONIGHT.
SHORT TERM: SCA CONDS ARE EXPECTED TO DVLP LATER TUE AND CONT THRU
MUCH OF WED AS DEEP LOW PRES TRACKS E OF THE WATERS...
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
MEZ005-006-011-015>017-032.
MARINE...NONE.
&&
$$
NEAR TERM...DUDA
SHORT TERM...KHW
LONG TERM...KHW
AVIATION...DUDA/KHW
MARINE...DUDA/KHW
AREA FORECAST DISCUSSION
NWS GRAY ME
248 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL GRADUALLY MOVE EAST OF THE GULF OF MAINE TODAY.
LOW PRESSURE WILL DEVELOP ALONG THE MID ATLANTIC COASTLINE ON TUESDAY...
BRINGING A CHANCE OF PRECIPITATION MAINLY TO EASTERN SECTIONS.
BRIEF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER LOW PRESSURE
SYSTEM PASSES NORTH ON THURSDAY WITH AN OCCLUDED FRONT CROSSING
NEW ENGLAND. HIGH PRESSURE OVER THE NORTHERN PLAINS WILL THEN
SLOWLY BUILD TOWARDS THE EAST THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
SFC TROF AND ASSOCIATED WEAK AREA OF LOW PRES OFF OF CAPE COD IS
CONTINUING TO PUMP PCPN INTO THE MIDCOAST. THAT LOW PRES HAS
ALLOWED WINDS TO BACK AROUND TO A MORE NLY DIRECTION...EFFECTIVELY
LOCKING THE COLDER AIR IN PLACE AT THE SFC. WHILE TEMPS ALONG THE
COAST ARE IN THE MID 30S...JUST INLAND THEY ARE AOB FREEZING.
ALOFT TEMPS ARE SLOWLY CREEPING UP...WITH HI-RES MODEL GUIDANCE
LIKE THE HRRR AND RAP SUGGESTING H9 AND H8 TEMPS RISING ABOVE
FREEZING BY 12Z FOR MUCH OF THE COAST AND COASTAL PLAIN. THAT
MEANS THE CAPITAL REGION WHERE IT HAS BEEN SNFL MUCH OF THE NIGHT
WILL SEE A GRADUAL TRANSITION TOWARDS A MIX WITH RA AND FZRA.
GUIDANCE HAS H9 TEMPS WARMING MORE QUICKLY THAN H8...SO GIVEN THAT
LACK OF A DEEP COLD LAYER NEAR THE SFC I HAVE REMOVED MUCH OF THE
PL FROM THE FORECAST. KGYX RADAR ALSO INDICATES THE 0.5 DEG
CORRELATION COEFFICIENT INFERRED MELTING LAYER GRADUALLY
INCREASING IN RANGE. THIS SUPPORTS THE NWP FORECAST WARMING
ALOFT...AND EXPECT THAT MIXING WILL BEGIN AROUND KAUG SOONER
RATHER THAN LATER.
ATTM ADVISORY IS SET TO EXPIRE AT 11Z. WILL CONTINUE IT UNTIL THAT
TIME AS THERE REMAINS SN...FZRA...AND FZDZ ACROSS THE ADVISORY
AREA. HOWEVER...WRF AND HRRR GUIDANCE CONTINUES PCPN UNTIL NEARLY
NOON ACROSS PARTS OF THE MIDCOAST. AN EXTENSION MAY BE NECESSARY
IF TEMPS TO DO NOT WARM ANY FURTHER AT THE SFC.
OTHERWISE...EVENTUALLY DIURNAL HEATING WINS OUT AND PCPN NEAR THE
COAST WILL FLIP TO ALL RA IF IT HASN/T ENDED ALREADY BY THAT TIME.
SFC TROF WILL LINGER NEARBY...AS IT SLOWLY DRIFTS TOWARDS DOWNEAST
ME. THIS COULD MEAN SCT/ISOLD SHWRS CONTINUE MUCH OF THE DAY FROM
JACKMAN TO KRKD.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/...
SFC TROF IS SLOW TO WEAKEN AND LIFT NEWD TONIGHT. IF IT LINGERS
OVER DOWNEAST ME SOME SCT TO ISOLD SHWRS ARE POSSIBLE THRU THE
NIGHT. PCPN WILL BE LIGHT...AND SHOULD STAY IN THE FORM OR RA OR
SN. ONE CONCERN COULD BE IF THE COLUMN DRIES OUT. THIS COULD BRING
A PERIOD OF DZ/FZDZ RATHER THAN SHWRS. THIS COULD BRING ANOTHER
ROUND OF SLICK CONDITIONS FOR THE INTERIOR MIDCOAST.
BY TUE MORNING COASTAL LOW PRES WILL BE ORGANIZING S OF SRN NEW
ENGLAND. WITH A LACK OF DOWNSTREAM RIDGING AND DELAYED ARRIVAL OF
NRN STREAM S/WV TROF THERE IS NOT MUCH TO KEEP THIS SYSTEM FROM
SLIDING OUT TO SEA. LATE INTERACTION WITH THE NRN STREAM WILL
SWING THE LOW PRES TOWARDS THE CANADIAN MARITIMES BY LATE TUE
NIGHT. IT IS AS IT DOES SO THAT PCPN SHIELD MAY BRUSH PORTIONS OF
THE MIDCOAST. HAVE KEPT LIKELY POP OFFSHORE FOR NOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE GRADUALLY INTENSIFIES EAST OF THE GULF OF MAINE
TUESDAY NIGHT. 00Z MODEL SUITE IN GOOD AGREEMENT WITH THE TRACK OF
THIS SYSTEM...KEEPING MUCH OF THE PRECIPITATION EAST OF OUR
REGION...OVER DOWNEAST MAINE.
A WEAK RIDGE OF HIGH PRESSURE CROSSES THE REGION WEDNESDAY
MORNING...BEFORE CLOUDS SPILL OVER THE RIDGE IN THE AFTERNOON.
PLENTY OF WARM AIR WILL ARRIVE WITH THE APPROACH OF AN OCCLUDED
FRONT...BRINGING SHOWERS OR PATCHY FREEZING RAIN OVER INTERIOR
SECTIONS ON WEDNESDAY NIGHT. TEMPERATURES ALOFT WILL MAKE IT
DIFFICULT FOR ANY SNOW...HOWEVER SURFACE TEMPERATURES MAY FALL TO
BELOW THE FREEZING LEVEL OVER NORTHERN AREAS DURING THE OVERNIGHT HOURS.
HIGH PRESSURE WILL GRADUALLY BUILD EAST FROM THE NORTHERN PLAINS
DURING THE PERIOD THURSDAY AND INTO THE WEEKEND. THIS WILL BRING
COOLER TEMPERATURES TO THE REGION...HOWEVER NOT A DIRECT BLOW OF
ARCTIC AIR TO NEW ENGLAND.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
SHORT TERM...AREAS OF IFR OR LOWER ALONG THE COAST AND INTERIOR
WILL BE VERY SLOW TO SCATTER OUT AND LIFT TODAY. EXPECTING MVFR
AND VFR CONDITIONS TO PROGRESS SW TO NE ALONG THE COAST THRU THE
AFTERNOON. INVOF KAUG...FZRA WILL BE POSSIBLE THIS MORNING...AS
WARMTH ALOFT PUSHES NWD. THIS AFTERNOON CLOUDS FROM THE SW WILL
PUSH ACROSS THE MTNS...WITH KHIE SEEING A PERIOD OF MVFR
CONDITIONS. WILL HAVE TO WATCH FOR MVFR OR LOWER CONDITIONS TO
WORK BACK INTO COASTAL TERMINALS AGAIN TONIGHT...AS ONSHORE FLOW
DEVELOPS AHEAD OF NEXT OCEAN LOW PRES.
LONG TERM...AREAS OF MVFR CONDITIONS ARE POSSIBLE TUESDAY NIGHT
OVER DOWNEAST MAINE. AREAS OF MVFR CONDITIONS ARE ALSO POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF AN
OCCLUDED FRONT.
&&
.MARINE...
SHORT TERM...WEAK LOW PRES IN THE GULF OF ME WILL KEEP WINDS
GUSTING AT OR JUST BELOW 25 KTS EARLY THIS MORNING. HOWEVER...THIS
NE FLOW WILL ALSO KEEP SEAS ABOVE 5 FT INTO THE
AFTERNOON...ESPECIALLY N OF PORT CLYDE. WILL KEEP SCA GOING FOR
THE OUTER WATERS UNTIL SEAS BEGIN TO SUBSIDE.
LONG TERM...THERE MAY BE BORDERLINE SCA CONDITIONS OVER EASTERN
SECTIONS WITH THE PASSAGE OF AN OFFSHORE SYSTEM TUESDAY NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MEZ013-014-019>022.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
ANZ150-152-154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
437 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE OFF THE SOUTHEAST COAST WILL INTENSIFY...AS IT
MOVES NORTHEAST OFF THE MID ATLANTIC COAST TODAY INTO TUESDAY
MORNING. HIGH PRESSURE WILL BUILD OVER THE AREA AND THEN PUSH
OFFSHORE TUESDAY AFTERNOON THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST UPR AIR PATTERN WAS GENERALLY RATHER ZONAL ACRS THE UNITED
STATES...WITH A WEAK SHORTWV TROF MOVING INTO THE ERN THIRD OF THE
U.S. EARLY THIS MORNG. AT THE SFC...WEAK LO PRES WAS JUST OFF THE
NC/SC CST. SFC OBS/SAT PIX WAS SHOWING SKY COVER WAS RANGING FM
CLEAR TO CLOUDY ACRS THE REGION...DUE TO SC DECK (5000-7000 FT) OVR
EXTRM NW/NRN CNTIES AND PATCHY DENSE FOG OVR PORTIONS OF SE VA AND
CSTL NE NC. LATEST MODELS INDICATE THE SHRTWV TROF SWINGING THRU
THE REGION THIS AFTN INTO TNGT...RESULTING IN THE SFC LO
INTENSIFYING AS IT LIFTS NE AWAY FM THE NC AND DELMARVA CST. DUE
TO THE PROGRESSIVE NATURE OF THE SHRTWV TROF...THE BULK OF DEEP
MOISTURE AND LIFT SHOULD BE SITUATED OFF THE CST. AS A
RESULT...WILL MAINTAIN ONLY A 40% POP OVER TH FAR SE (FOR LIGHT
QPF AMOUNTS < .10") FOR LATER THIS MORNG INTO EARLY THIS EVENG.
OTHERWISE...MOST OF THE CWA WILL ONLY SEE SOME MID/HIGH LEVEL
CLOUDINESS TODAY INTO TNGT. HIGHS TODAY WILL GENERALLY BE IN THE
LWR TO MID 50S. LOWS TNGT WILL RANGE FM THE LWR 30S TO THE LWR
40S...WITH THE SKY AVERAGING PRTLY CLOUDY LATER TNGT INTO WED
MORNG.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
THE LOW WILL CONTINUE TO INTENSIFY DURING TUE...AS IT MOVES
FARTHER AWAY TO THE NE. THE RESULT WILL BE A DRY PERIOD TUE/WED AS
WEAK HIGH PRESSURE BUILDS ACRS THE AREA AS A TROUGH IS SLOW TO
APPROACH FROM THE WEST. TEMPERATURES WILL BE FAIRLY MILD WITH
HIGHS INTO THE MID/UPPER 50S TUE...LOWS IN THE 30S TO LOWER 40S
TUE NIGHT...AND INTO THE UPPER 50S TO LOWER/POSSIBLY MID 60S ON
WED AS SOUTHERLY FLOW INCREASES. THE CAVEAT HERE IS THAT MODEL
SOUNDINGS SHOW SOME LOW MOISTURE THAT MAY BE TOUGH TO BREAK ON
WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE MAIN FEATURE FOR THE LONG TERM WILL BE AN ARCTIC FRONTAL
BOUNDARY THAT WILL MOVE THROUGH THE MID ATLANTIC STATES LATE IN THE
WEEK. THE MAIN ISSUE WILL BE PCPN RATHER THAN TEMPERATURES AS THE
FRONT SLOWS DOWN AND ABUNDANT MOISTURE STREAMS INTO THE AREA FROM
THE SOUTHWEST. DUE TO UPPER LEVEL RIDGING IN THE SOUTHEASTERN
STATES...THE AIR MASS WILL BE SHALLOW AND TEMPERATURES WILL BE SLOW
TO FALL. EVENTUAL READINGS ARE NOT EXPECTED TO BE AS COLD AS THOSE
WHICH WERE EXPERIENCED RECENTLY.
THE MODELS HAD THE FRONT STALLING TEMPORARILY OVER THE OHIO VALLEY
YESTERDAY BUT CURRENT MODEL RUNS HAVE THIS OCCURRING OVER THE MID
ATLANTIC AROUND THURSDAY NIGHT AND FRIDAY. THE EURO LINES UP WELL
WITH HPC AND FOLLOWED CLOSE TO IT WITH THE FORECAST. THIS SET UP
WOULD INDICATE AN EXTENSIVE AND SLOW MOVING PCPN PATTERN WITH AREAS
OF LIKELY POPS MAINLY BEHIND THE FRONT BEGINNING IN NORTHWEST
PORTIONS FRIDAY AND FRIDAY NIGHT AND INTO THE SOUTHEAST PART OF THE
AREA SATURDAY. CURRENT INDICATIONS ARE THAT PRECIPITATION DIMINISHES
FROM THE NORTH SATURDAY NIGHT AND NO SIGNIFICANT PTYPE ISSUES ARE
INDICATED THROUGH SUNDAY.
TEMPERATURES WILL START OUT MILD WITH LOWS WEDNESDAY AND THURSDAY
NIGHTS IN THE MID 40S TO MID 50S. HIGHS THURSDAY WILL BE MAINLY IN
THE 60S WITH UPR 50S PSBL ON THE MD EASTERN SHORE AND NEAR 70 ALONG
THE VA/NC BORDER. TEMPERATURES FRIDAY AND BEYOND WILL DEPEND ON THE
ULTIMATE PROGRESS OF THE FRONT. NON DIURNAL TEMPERATURE TRENDS ARE
PSBL BUT DID NOT GET FANCY THIS FAR OUT. CURRENT FORECASTS HAVE
HIGHS FROM THE MID 50S NORTH TO NEAR 70 IN OUR NORTH CAROLINA
COUNTIES FRIDAY. LOWS FRIDAY NIGHT ARE FORECAST TO RANGE FROM THE
UPR 30S NORTH TO LWR 50S NEAR THE ALBEMARLE SOUND. HIGHS SATURDAY
ARE EXPECTED TO BE FROM THE MID 40S NORTH TO MID 50S IN NORTH
CAROLINA AND IN THE 40S ACROSS THE AREA SUNDAY. LOWS SATURDAY NIGHT
LOOK TO BE IN THE 30S.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
LATEST OBS REFLECT LIFR FOG AT PHF/ORF/ECG IN ASSOCIATION WITH
DEVELOPING ADVECTION FOG OUT AHEAD OF DEVELOPING LOW PRESSURE.
LIGHT WINDS/AND NO AVAILABLE MIXING SUGGESTS THAT THIS FOG WILL
REMAIN IN PLACE THROUGH MID-MORNING.
THEREAFTER, NEXT ISSUE WL BE WITH RAIN CHANCES W/ DEVELOPING LOW
PRESSURE OFF THE N CAROLINA COAST. THIS SYSTEM WILL MOVE NE ACROSS
THE OUTER BANKS THIS MORNING BEFORE TRACKING OFF THE CAROLINA
COAST MONDAY AFTN. MODELS STILL DIFFER ON HOW FAR NW PCPN
ACTUALLY GETS BEFORE MOVING OFFSHORE. NEW HRRR DOES BRING RAIN
TOWARDS ECG BY 16Z. WL HOLD OFF WITH MENTIONING PREDOMINATE -SHRA
GROUP IN TAF FOR THIS ISSUANCE. OTW EXPECT MIDLVLS REMAIN TOO DRY
FARTHER NORTH. WL KEEP BKN HIGH / MID LEVEL CLOUD DECK IN PLACE
THROUGH TONIGHT AT ALL TERMINALS, CLEARING LATE MONDAY NIGHT.
OUTLOOK...MAINLY VFR SHOULD PREVAIL BEHIND THE SYSTEM TUE, AND WL
CONTINUE THROUGH THE MID WEEK PERIOD. AN EXTENDED PERIOD OF PCPN
WITH MVFR/IFR CONDS SHOULD BEGIN FRIDAY AHEAD OF A COLD FRONT
APPROACHING FROM THE NW.
&&
.MARINE...
HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER THROUGH THE MIDDLE
OF THE COMING WEEK...RESULTING IN RELATIVELY BENIGN BOATING
CONDITIONS. THE ONLY EXCEPTION WILL BE A SLIGHT INCREASE IN
WINDS/WAVES MONDAY NIGHT/TUESDAY AS LOW PRESSURE LIFTS NORTHEAST
WELL OFF THE MID-ATLANTIC COAST. LIGHT W-SW WINDS BECOME NW LATE
TONIGHT BEFORE VEERING TO THE NE EARLY MONDAY. WINDS REMAIN NE
THROUGH THE DAY MONDAY BEFORE BACKING TO THE NW MONDAY NIGHT/TUESDAY
AS THE WEAK LOW PRESSURE SYSTEM PULLS AWAY FROM THE AREA. HIGH
PRESSURE WILL REBUILD LATE WED/THU...BEFORE SLIDING OFFSHORE LATER
THURSDAY-FRIDAY. SUB-SCA CONDITIONS ARE EXPECTED THROUGH THIS PERIOD.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TMG
NEAR TERM...LKB/TMG
SHORT TERM...LKB/TMG
LONG TERM...LSA
AVIATION...MAM
MARINE...MAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
142 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE OFF THE SOUTHEAST COAST WILL MOVE NORTHEAST OFF
THE NORTH CAROLINA COAST OVERNIGHT INTO MONDAY MORNING. THE LOW
WILL INTENSIFY WELL OFF THE MID ATLANTIC COAST MONDAY AFTERNOON
INTO TUESDAY MORNING. HIGH PRESSURE WILL BUILD OVER THE AREA AND
AND THEN PUSH OFFSHORE TUESDAY AFTERNOON THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
THE LATEST SURFACE ANALYSIS INDICATES A RATHER NEBULOUS PRESSURE
PATTERN ACROSS THE MID ATLANTIC. ALOFT...WATER VAPOR IMAGERY
INDICATES ZONAL FLOW ACROSS THE REGION...WITH AN EMBEDDED
SHORTWAVE TROUGH PASSING OFF THE SOUTHEAST COAST. FARTHER
UPSTREAM...A TROUGH IS DIGGING ACROSS THE SOUTHERN PLAINS. THE
LATEST GUIDANCE INDICATES THE PATTERN REMAINS ZONAL THROUGH MUCH
OF THE OVERNIGHT...BEFORE AMPLIFYING TOWARD MORNING AS THE CENTRAL
PLAINS TROUGH SWINGS ACROSS THE SOUTHEAST. THIS WILL ALLOW MUCH OF
THE LOCAL AREA TO REMAIN CLEAR OVERNIGHT...WITH THE EXCEPTION OF
THE FAR N...WHERE A MID-CLOUD DECK WILL LINGER FOR THE NEXT
SEVERAL HOURS...WHICH THEN LIFTS N AS THE MID-LEVEL FLOW PATTERN
BECOMES SW. SURFACE OBSERVATIONS ARE INDICATING SOME FOG OVER SE
PORTIONS THIS EVENING...AND IT APPEARS PATCHY FOG SHOULD PERSIST
THROUGH MUCH OF THE NIGHT. PATCHY FOG IS ALSO EXPECTED TO EXPAND N
ACROSS EASTERN VA AFTER MIDNIGHT. WITH SKIES REMAINING MOSTLY
CLEAR FOR MUCH OF THE NIGHT ACROSS MOST OF THE AREA...EXPECT MINS
TO DROP INTO THE UPPER 20S TO LOWER 30S OVER MUCH OF THE
CWA. THE NW PIEDMONT WILL LIKELY LINGER IN THE LOW 40S FOR THE
NEXT FEW HOURS BEFORE THE MID-CLOUD DECK LIFTS N. POPS WERE
REMOVED FOR THE FAR SE ZONES OVERNIGHT PER LATEST SATELLITE
IMAGERY AND NUMERICAL GUIDANCE.
ON MON...MODELS DEPICT THE UPPER TROUGH SWINGING THROUGH THE
REGION AROUND 18Z...BUT BULK OF DEEP MOISTURE AN LIFT SHOULD BE
SITUATED OFF THE COAST SO WILL ONLY CARRY ABOUT A 40% POP OVER TH
FAR SE (FOR LIGHT QPF AMOUNTS < .10"). MOST OF THE CWA WILL ONLY
SEE SOME MID/HIGH LEVEL CLOUDINESS THROUGH THE DAY. HIGHS GENLY IN
THE MID 50S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
THE LOW WILL THEN RAPIDLY INTENSIFY MON NIGHT/TUE...BUT WILL BE WELL
OFFSHORE WHILE DOING SO. THE RESULT WILL BE A DRY PERIOD MON
NIGHT/TUE/WED AS WEAK HIGH PRESSURE BUILDS ACRS THE AREA AS A
TROUGH IS SLOW TO APPROACH FROM THE WEST. TEMPERATURES WILL BE
FAIRLY MILD WITH HIGHS INTO THE MID/UPPER 50S TUE...LOWS IN THE
30S TO LOWER 40S TUE NIGHT...AND INTO THE UPPER 50S TO LOWER/POSSIBLY
MID 60S ON WED AS SOUTHERLY FLOW INCREASES. THE CAVEAT HERE IS
THAT MODEL SOUNDINGS SHOW SOME LOW MOISTURE THAT MAY BE TOUGH TO
BREAK ON WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE MAIN FEATURE FOR THE LONG TERM WILL BE AN ARCTIC FRONTAL
BOUNDARY THAT WILL MOVE THROUGH THE MID ATLANTIC STATES LATE IN THE
WEEK. THE MAIN ISSUE WILL BE PCPN RATHER THAN TEMPERATURES AS THE
FRONT SLOWS DOWN AND ABUNDANT MOISTURE STREAMS INTO THE AREA FROM
THE SOUTHWEST. DUE TO UPPER LEVEL RIDGING IN THE SOUTHEASTERN
STATES...THE AIR MASS WILL BE SHALLOW AND TEMPERATURES WILL BE SLOW
TO FALL. EVENTUAL READINGS ARE NOT EXPECTED TO BE AS COLD AS THOSE
WHICH WERE EXPERIENCED RECENTLY.
THE MODELS HAD THE FRONT STALLING TEMPORARILY OVER THE OHIO VALLEY
YESTERDAY BUT CURRENT MODEL RUNS HAVE THIS OCCURRING OVER THE MID
ATLANTIC AROUND THURSDAY NIGHT AND FRIDAY. THE EURO LINES UP WELL
WITH HPC AND FOLLOWED CLOSE TO IT WITH THE FORECAST. THIS SET UP
WOULD INDICATE AN EXTENSIVE AND SLOW MOVING PCPN PATTERN WITH AREAS
OF LIKELY POPS MAINLY BEHIND THE FRONT BEGINNING IN NORTHWEST
PORTIONS FRIDAY AND FRIDAY NIGHT AND INTO THE SOUTHEAST PART OF THE
AREA SATURDAY. CURRENT INDICATIONS ARE THAT PRECIPITATION DIMINISHES
FROM THE NORTH SATURDAY NIGHT AND NO SIGNIFICANT PTYPE ISSUES ARE
INDICATED THROUGH SUNDAY.
TEMPERATURES WILL START OUT MILD WITH LOWS WEDNESDAY AND THURSDAY
NIGHTS IN THE MID 40S TO MID 50S. HIGHS THURSDAY WILL BE MAINLY IN
THE 60S WITH UPR 50S PSBL ON THE MD EASTERN SHORE AND NEAR 70 ALONG
THE VA/NC BORDER. TEMPERATURES FRIDAY AND BEYOND WILL DEPEND ON THE
ULTIMATE PROGRESS OF THE FRONT. NON DIURNAL TEMPERATURE TRENDS ARE
PSBL BUT DID NOT GET FANCY THIS FAR OUT. CURRENT FORECASTS HAVE
HIGHS FROM THE MID 50S NORTH TO NEAR 70 IN OUR NORTH CAROLINA
COUNTIES FRIDAY. LOWS FRIDAY NIGHT ARE FORECAST TO RANGE FROM THE
UPR 30S NORTH TO LWR 50S NEAR THE ALBEMARLE SOUND. HIGHS SATURDAY
ARE EXPECTED TO BE FROM THE MID 40S NORTH TO MID 50S IN NORTH
CAROLINA AND IN THE 40S ACROSS THE AREA SUNDAY. LOWS SATURDAY NIGHT
LOOK TO BE IN THE 30S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LATEST OBS REFLECT LIFR FOG AT PHF/ORF/ECG IN ASSOCIATION WITH
DEVELOPING ADVECTION FOG OUT AHEAD OF DEVELOPING LOW PRESSURE.
LIGHT WINDS/AND NO AVAILABLE MIXING SUGGESTS THAT THIS FOG WILL
REMAIN IN PLACE THROUGH MID-MORNING.
THEREAFTER, NEXT ISSUE WL BE WITH RAIN CHANCES W/ DEVELOPING LOW
PRESSURE OFF THE N CAROLINA COAST. THIS SYSTEM WILL MOVE NE ACROSS
THE OUTER BANKS THIS MORNING BEFORE TRACKING OFF THE CAROLINA
COAST MONDAY AFTN. MODELS STILL DIFFER ON HOW FAR NW PCPN
ACTUALLY GETS BEFORE MOVING OFFSHORE. NEW HRRR DOES BRING RAIN
TOWARDS ECG BY 16Z. WL HOLD OFF WITH MENTIONING PREDOMINATE -SHRA
GROUP IN TAF FOR THIS ISSUANCE. OTW EXPECT MIDLVLS REMAIN TOO DRY
FARTHER NORTH. WL KEEP BKN HIGH / MID LEVEL CLOUD DECK IN PLACE
THROUGH TONIGHT AT ALL TERMINALS, CLEARING LATE MONDAY NIGHT.
OUTLOOK...MAINLY VFR SHOULD PREVAIL BEHIND THE SYSTEM TUE, AND WL
CONTINUE THROUGH THE MID WEEK PERIOD. AN EXTENDED PERIOD OF PCPN
WITH MVFR/IFR CONDS SHOULD BEGIN FRIDAY AHEAD OF A COLD FRONT
APPROACHING FROM THE NW.
&&
.MARINE...
HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER THROUGH THE MIDDLE
OF THE COMING WEEK...RESULTING IN RELATIVELY BENIGN BOATING
CONDITIONS. THE ONLY EXCEPTION WILL BE A SLIGHT INCREASE IN
WINDS/WAVES MONDAY NIGHT/TUESDAY AS LOW PRESSURE LIFTS NORTHEAST
WELL OFF THE MID-ATLANTIC COAST. LIGHT W-SW WINDS BECOME NW LATE
TONIGHT BEFORE VEERING TO THE NE EARLY MONDAY. WINDS REMAIN NE
THROUGH THE DAY MONDAY BEFORE BACKING TO THE NW MONDAY NIGHT/TUESDAY
AS THE WEAK LOW PRESSURE SYSTEM PULLS AWAY FROM THE AREA. HIGH
PRESSURE WILL REBUILD LATE WED/THU...BEFORE SLIDING OFFSHORE LATER
THURSDAY-FRIDAY. SUB-SCA CONDITIONS ARE EXPECTED THROUGH THIS PERIOD.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LKB
NEAR TERM...AJZ/LKB
SHORT TERM...LKB/TMG
LONG TERM...LSA
AVIATION...MPR/MAM
MARINE...JDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 PM EST MON DEC 2 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 506 PM EST MON DEC 2 2013
MAIN FCST CONCERN IN THE SHORT TERM IS SNOW ACCUMULATIONS WITH A
RATHER PERSISTENT -SN REGIME SETTING UP.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW RELATIVELY ZONAL FLOW
ACROSS THE NRN PLAINS AND UPPER GREAT LAKES. ONE SHORTWAVE HAS MOVED
E OF UPPER MI...ANOTHER IS OVER THE ERN DAKOTAS/WRN MN WHILE A
WELL-DEFINED MID LEVEL LOW IS NOTED OVER THE PACIFIC NW. PCPN
TONIGHT/EARLY TUE WILL BE ASSOCIATED WITH THE SHORTWAVE HEADING INTO
MN...THEN ANOTHER ROUND OF FORCING MAY BEGIN TO OVERSPREAD THE AREA
LATER TUE AS PACIFIC NW SYSTEM EMERGES INTO THE NRN PLAINS.
RELATIVELY MODEST ISENTROPIC ASCENT/WAA REGIME AHEAD OF THE WRN MN
SHORTWAVE IS GENERATING AN AREA OF -SN FROM NE MN ACROSS FAR WRN
UPPER MI INTO NW WI. ANOTHER BAND OF SNOW IS LINED UP JUST AHEAD OF
THE SHORTWAVE TROF AXIS. AS SHORTWAVE AND ASSOCIATED ISENTROPIC
ASCENT SHIFT E...EXPECT -SN TO SPREAD GRADUALLY E ACROSS ROUGHLY THE
W HALF OF UPPER MI TONIGHT. BETTER ASCENT GENERALLY OCCURS OVER FAR
W INTO SRN UPPER MI...BUT TENDS TO WEAKEN WITH TIME...ESPECIALLY
FARTHER E AND NE...AS SHORTWAVE WEAKENS. MAY END UP WITH A PERIOD OF
STEADIER -SN OVER THE FAR W THIS EVENING UNDER WAA REGIME AND THEN
THERE WILL BE ANOTHER PUSH OF STEADIER -SN AS BAND OF SNOW JUST
AHEAD OF SHORTWAVE TROF AXIS SWINGS INTO THE AREA. IN THE END...
GREATEST SNOW ACCUMULATIONS TONIGHT THRU TUE MORNING WILL OCCUR OVER
THE FAR W AND TO SOME EXTENT TOWARD SCNTRL UPPER MI. UTILIZATION OF
MIXING RATIOS ON THE 290K SFC (ROUGHLY BTWN 700-750MB) SUGGESTS
POTENTIAL FOR 4-6 INCH ACCUMULATIONS ACROSS THE W AND SCNTRL TONIGHT
THRU TUE MORNING. HOWEVER...WITH A LACK OF FOCUSED UPWARD MOTION
THRU A RELATIVELY HIGH/NARROW DGZ...SNOW RATIOS WILL BE ON THE LOW
SIDE...PROBABLY SOMETHING LIKE 10-12 TO 1. ALSO...SINCE ISENTROPIC
ASCENT IS NEVER ESPECIALLY STRONG...SNOW ACCUMULATIONS WILL LIKELY
END UP BLO ADVY CRITERIA. ONLY PLACE THAT WILL BE CLOSE TO ADVY IS
IN THE KIWD VCNTY. FOR NOW...WILL HOLD OFF ANY HEADLINES AND MONITOR
TRENDS THIS EVENING. OVERALL TONIGHT/TUE MORNING...EXPECT MORE OF A
PERSISTENT -SN WITH NOT MUCH IN THE WAY OF NOTABLY HEAVIER PERIODS
OF SNOW.
ON TUE...AREA OF DIMINISHING -SN ASSOCIATED WITH WEAKENING SHORTWAVE
WILL CONTINUE TO LIFT N AND E. MEANWHILE...SYSTEM CURRENTLY OVER THE
PACIFIC NW WILL EMERGE OVER THE NRN PLAINS. AS IT DOES SO...
ISENTROPIC ASCENT MAY STRENGTHEN AGAIN IN THE AFTN OR INTO TUE
EVENING...THOUGH THERE IS SOME DISAGREEMENT ON HOW STRONG THE
ISENTROPIC ASCENT WILL BE. SO...AFTER DIMINISHING -SN INTO THE AFTN
HRS...-SN MAY PICK UP AGAIN FROM THE SW LATER IN THE AFTN. MAY SEE
AN INCH OR SO OF SNOW LATE IN THE DAY TOWARD THE WI BORDER.
SPECIAL WEATHER STATEMENT HAS BEEN UPDATED TO REFLECT THE LATEST
THINKING ON THE WINTRY WEATHER EXPECTED OVER THE NEXT FEW DAYS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 513 PM EST MON DEC 2 2013
SIGNIFICANT SNOWFALL IS POSSIBLE TUESDAY NIGHT INTO THURSDAY MORNING
FOR WEST AND CENTRAL UPPER MICHIGAN
AND THE SAGA CONTINUES...MODELS DISAGREEING ON HOW AND WHEN THE LOW
PRESSURE SYSTEM WILL CROSS UPPER MI. THOUGH ALL HAVE SIMILAR TRACKS
WITH SLIGHT DIFFERENCES...THE 12Z GFS/NAM AND THE 12Z GEM/12Z ECMWF
ARE WIDELY DIFFERENT IN TERMS OF TIMING.
ON THE TRACK OVERALL...MODELS TAKE THE LOW FROM THE CENTRAL PLAINS
INTO THE JAMES BAY/NORTHERN ONTARIO REGION. THE 12Z GEM/12Z
UKMET/12Z ECMWF TAKE THE LOW FURTHEST SOUTHEAST...MOVING FROM
SOUTHEASTERN WI TO EASTERN UPPER MI...THEN INTO ONTARIO SOUTH OF
JAMES BAY. THE GFS/NAM TAKE THE LOW TRACK FROM WESTERN WI INTO
CENTRAL UPPER MI...THEN JUST SOUTH OF JAMES BAY AND NORTHEAST OF
LAKE SUPERIOR.
TIMING WISE...THE 12 GFS/NAM HAVE A MUCH QUICKER SOLUTION THAN THE
ECMWF/GEM...AND THE UKMET IS SLIGHTLY SLOWER THAN ALL. FOR
EXAMPLE...WHEN THE GFS/NAM HAVE THE LOW SOUTH OF JAMES BAY...THE 12Z
ECMWF/12Z GEM ARE JUST CROSSING IT OVER LAKE SUPERIOR/EASTERN UPPER
MI. THE UKMET HAS IT OVER SOUTHEASTERN UPPER MI/NORTHERN LAKE MI.
OVERALL...SINCE CONSISTENCY WISE THE ECWMF SEEMS STEADIER...AND
BECAUSE OFTEN TIMES THE GFS SEEMS TO RUSH THINGS THROUGH/AMPLIFY
THINGS...OPTED TO LEAN TOWARDS THE SLOWER GEM/ECMWF SOLUTION FOR
TIMING. FOR THE EXACT TRACK OF THE LOW...USED A 12Z GEM/12Z ECMWF
COMPROMISE.
USING THE CHOSEN MODEL TRACKS/TIMING...A BROAD AREA OF 850MB WAA AND
ISENTROPIC ASCENT ON THE 290K SFC WILL BRING WIDESPREAD
PRECIPITATION ACROSS UPPER MICHIGAN AS THE SYSTEM APPROACHES TUESDAY
NIGHT THROUGH WEDNESDAY MORNING. SOUNDINGS SUGGEST THIS FIRST BURST
OF PRECIPITATION WILL BE IN THE FORM OF SNOW. BY WEDNESDAY
AFTERNOON...AS THE LOW REACHES IOWA AND ILLINOIS/SOUTHERN WI...WARM
MOIST AIR WRAPPING AROUND THE SURFACE LOW DEVELOPS A 700MB FGEN BAND
THAT ALIGNS ITSELF SOUTHWEST TO NORTHEAST...FROM SOUTHEASTERN MN TO
JUST NORTHEAST OF LAKE SUPERIOR...ACROSS THE WESTERN AND CENTRAL CWA.
BY 00Z THURSDAY SLIGHT DIFFERENCES IN THE TRACK OF THE LOW BETWEEN
THE GEM/ECMWF START TO AFFECT THE TEMPERATURE/PTYPE FORECAST. THE
12Z ECMWF CENTERS THE LOW OVER CENTRAL WI...WHICH BRINGS A NOSE OF
WARMER AIR SLIGHTLY FURTHER NORTH AND CENTRAL. THIS WOULD BRING
CHANCES FOR MIXED PRECIPITATION/RAIN INTO THE NORTH CENTRAL AND
EAST. THE GEM KEEPS THE LOW SOUTHEAST...CENTERED OVER SOUTHEASTERN
WI BY 00Z THUR AND NOT QUITE PULLING THAT WARMER AIR AROUND INTO THE
CENTRAL. THIS WOULD KEEP THE WEST AND NORTH CENTRAL ALL SNOW...AND
THE EAST A MIX/RAIN. BY 12Z THURSDAY HOWEVER...THE MODELS ALL AGREE
ON SNOW BEING THE PTYPE. THE EXACT TRACK WILL AFFECT WHAT TYPE OF
SNOWFALL AMOUNTS WE SEE. AGAIN...WENT WITH AN ECMWF/GEM COMPROMISE
FOR TEMPS/PTYPE...WHICH KEEPS THE PRECIPITATION SNOW FOR A MAJORITY
OF THE FORECAST AREA...ONLY MIXING/RAIN ACROSS THE FAR SOUTHEASTERN
CWA. OVERALL...ACCUMULATIONS COULD BE OVER 6-8 INCHES ACROSS THE
WEST AND CENTRAL U.P. FROM TUESDAY NIGHT INTO THURSDAY MORNING.
AS THE LOW MOVES OFF INTO ONTARIO JUST NORTHEAST OF LAKE SUPERIOR
BETWEEN 06Z AND 12Z THURSDAY...UPPER MICHIGAN IS QUICKLY BROUGHT
INTO AN AREA OF STRONG CAA ON WEST TO NORTHWEST WINDS. 850MB TEMPS
QUICKLY DIP INTO THE -15 TO -20C RANGE IN THE WAKE OF THE LOW...AND
ON ON WEST TO NORTHWEST WINDS LAKE EFFECT CHANCES QUICKLY BECOME THE
MAIN CONCERN. GRADUALLY AS THE LOW HOVERS OVER JAMES BAY AREA FRIDAY
AND SATURDAY...850MB TEMPS CONTINUE TO DROP...REACHING AS LOW AS
-22C...WITH THE KEWEENAW AND WESTERN UPPER MI IN THE COLDEST OF THAT
AIR. THIS WILL BRING VERY COLD TEMPERATURES TO UPPER MICHIGAN FRIDAY
NIGHT THROUGH SATURDAY NIGHT...WITH WIND CHILLS AS LOW AS -25C IN
SOME PLACES OUT WEST.
SATURDAY AND SUNDAY...HIGH PRESSURE STEADILY EXPANDING FROM THE
CANADIAN PRAIRIE...ACROSS THE GREAT LAKES...AND INTO THE ATLANTIC.
GENERALLY IN THIS TIME FRAME...WINDS ARE WESTERLY TO
NORTHWESTERLY...850MB TEMPS RANGE FROM -22C TO -15C...AND THERE ARE
SHORTWAVES ROUNDING THE LOW OVER JAMES BAY. THESE SHORTWAVES WILL
SERVE TO ASSIST THE EXPECTED LAKE EFFECT SNOW SHOWERS DURING THESE
PERIODS...WITH CHANCES LESSENING AS THE LOW DEPARTS AND THE HIGH
STRENGTHENS. SNOW ACCUMULATIONS COULD BE HAMPERED HOWEVER...AS THE
DGZ DIPS CLOSER TO THE GROUND WITH THE EXTREME COLD. ON MONDAY
MODELS DISAGREE SLIGHTLY ON ANOTHER AREA OF LOW PRESSURE MOVING INTO
THE GREAT LAKES REGION...SO KEPT CONSENSUS PRECIPITATION CHANCES
BEGINNING ACROSS THE NON-LAKE EFFECT AREAS AS IT APPROACHES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON DEC 2 2013
DISTURBANCE APPROACHING FROM THE NRN PLAINS WILL SPREAD -SN FROM W
TO E ACROSS THE AREA THIS AFTN AND TONIGHT. PRIOR TO THE ARRIVAL OF
-SN...VFR CONDITIONS WILL PREVAIL...THOUGH DEVELOPING UPSLOPE
FLOW WILL PROBABABLY LEAD TO MFVR CIGS DEVELOPING AT KCMX/KSAW LATER
THIS AFTN/EARLY THIS EVENING...WELL BEFORE THE ONSET OF -SN AT THOSE
TERMINALS. SEVERAL HRS AFTER THE -SN BEGINS AT EACH TERMINAL...
CONDITIONS WILL DETERIORATE TO IFR. MAY SEE SOME IMPROVEMENT AT KIWD
TUE MORNING AS STEADIER -SN SHIFTS E AND NE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 PM EST MON DEC 2 2013
AS LOW PRES BEGINS TO ORGANIZE IN THE PLAINS AND HIGH PRES BUILDS
ACROSS CNTRL CANADA AND INTO NRN ONTARIO...E TO SE WINDS WILL BE ON
THE INCREASE TONIGHT...AND E WINDS WILL INCREASE FURTHER TUE. EXPECT
WINDS TO REACH GALE FORCE OVER WRN LAKE SUPERIOR TUE AFTN THU WED
MORNING AS TERRAIN SURROUNDING THE LAKE ENHANCES THE E FLOW. THE LOW
WILL MOVE ACROSS THE UPPER GREAT LAKES LATE WED. IN THE WAKE OF THE
LOW...VERY COLD AIR ADVECTING OVER THE RELATIVELY WARM WATERS WILL
INCREASE INSTABILITY AND RESULT IN W TO NW GALES AT TIMES FOR
PORTIONS OF LAKE SUPERIOR WED NIGHT/THU. CONTINUED FLOW OF VERY COLD
AIR MAY RESULT IN PERIODIC GALES EVEN THRU FRI/SAT. BUILDING WAVES
AND THE ARRIVAL OF THE ARCTIC AIR WILL ALSO CAUSE INCREASING
FREEZING SPRAY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 1 PM EST /NOON CST/ TUESDAY TO 10 AM EST /9 AM
CST/ WEDNESDAY FOR LSZ162.
GALE WARNING FROM 4 PM TUESDAY TO 10 AM EST WEDNESDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...MCD
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 PM EST MON DEC 2 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 506 PM EST MON DEC 2 2013
MAIN FCST CONCERN IN THE SHORT TERM IS SNOW ACCUMULATIONS WITH A
RATHER PERSISTENT -SN REGIME SETTING UP.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW RELATIVELY ZONAL FLOW
ACROSS THE NRN PLAINS AND UPPER GREAT LAKES. ONE SHORTWAVE HAS MOVED
E OF UPPER MI...ANOTHER IS OVER THE ERN DAKOTAS/WRN MN WHILE A
WELL-DEFINED MID LEVEL LOW IS NOTED OVER THE PACIFIC NW. PCPN
TONIGHT/EARLY TUE WILL BE ASSOCIATED WITH THE SHORTWAVE HEADING INTO
MN...THEN ANOTHER ROUND OF FORCING MAY BEGIN TO OVERSPREAD THE AREA
LATER TUE AS PACIFIC NW SYSTEM EMERGES INTO THE NRN PLAINS.
RELATIVELY MODEST ISENTROPIC ASCENT/WAA REGIME AHEAD OF THE WRN MN
SHORTWAVE IS GENERATING AN AREA OF -SN FROM NE MN ACROSS FAR WRN
UPPER MI INTO NW WI. ANOTHER BAND OF SNOW IS LINED UP JUST AHEAD OF
THE SHORTWAVE TROF AXIS. AS SHORTWAVE AND ASSOCIATED ISENTROPIC
ASCENT SHIFT E...EXPECT -SN TO SPREAD GRADUALLY E ACROSS ROUGHLY THE
W HALF OF UPPER MI TONIGHT. BETTER ASCENT GENERALLY OCCURS OVER FAR
W INTO SRN UPPER MI...BUT TENDS TO WEAKEN WITH TIME...ESPECIALLY
FARTHER E AND NE...AS SHORTWAVE WEAKENS. MAY END UP WITH A PERIOD OF
STEADIER -SN OVER THE FAR W THIS EVENING UNDER WAA REGIME AND THEN
THERE WILL BE ANOTHER PUSH OF STEADIER -SN AS BAND OF SNOW JUST
AHEAD OF SHORTWAVE TROF AXIS SWINGS INTO THE AREA. IN THE END...
GREATEST SNOW ACCUMULATIONS TONIGHT THRU TUE MORNING WILL OCCUR OVER
THE FAR W AND TO SOME EXTENT TOWARD SCNTRL UPPER MI. UTILIZATION OF
MIXING RATIOS ON THE 290K SFC (ROUGHLY BTWN 700-750MB) SUGGESTS
POTENTIAL FOR 4-6 INCH ACCUMULATIONS ACROSS THE W AND SCNTRL TONIGHT
THRU TUE MORNING. HOWEVER...WITH A LACK OF FOCUSED UPWARD MOTION
THRU A RELATIVELY HIGH/NARROW DGZ...SNOW RATIOS WILL BE ON THE LOW
SIDE...PROBABLY SOMETHING LIKE 10-12 TO 1. ALSO...SINCE ISENTROPIC
ASCENT IS NEVER ESPECIALLY STRONG...SNOW ACCUMULATIONS WILL LIKELY
END UP BLO ADVY CRITERIA. ONLY PLACE THAT WILL BE CLOSE TO ADVY IS
IN THE KIWD VCNTY. FOR NOW...WILL HOLD OFF ANY HEADLINES AND MONITOR
TRENDS THIS EVENING. OVERALL TONIGHT/TUE MORNING...EXPECT MORE OF A
PERSISTENT -SN WITH NOT MUCH IN THE WAY OF NOTABLY HEAVIER PERIODS
OF SNOW.
ON TUE...AREA OF DIMINISHING -SN ASSOCIATED WITH WEAKENING SHORTWAVE
WILL CONTINUE TO LIFT N AND E. MEANWHILE...SYSTEM CURRENTLY OVER THE
PACIFIC NW WILL EMERGE OVER THE NRN PLAINS. AS IT DOES SO...
ISENTROPIC ASCENT MAY STRENGTHEN AGAIN IN THE AFTN OR INTO TUE
EVENING...THOUGH THERE IS SOME DISAGREEMENT ON HOW STRONG THE
ISENTROPIC ASCENT WILL BE. SO...AFTER DIMINISHING -SN INTO THE AFTN
HRS...-SN MAY PICK UP AGAIN FROM THE SW LATER IN THE AFTN. MAY SEE
AN INCH OR SO OF SNOW LATE IN THE DAY TOWARD THE WI BORDER.
SPECIAL WEATHER STATEMENT HAS BEEN UPDATED TO REFLECT THE LATEST
THINKING ON THE WINTRY WEATHER EXPECTED OVER THE NEXT FEW DAYS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 505 AM EST MON DEC 2 2013
VERY CHALLENGING FORECAST IN STORE FOR THE TUESDAY THROUGH WEDNESDAY
NIGHT TIME FRAME. BEHIND THIS SYSTEM...LAKE EFFECT SNOW AND WELL
BELOW NORMAL TEMPERATURES ARE EXPECTED TO MOVE IN FOR THE LAST HALF
OF THE WORK WEEK INTO THE WEEKEND WITH DANGEROUS WIND CHILLS
EXPECTED TO APPROACH -30F BY FRIDAY NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...MODEL AGREEMENT HAS INCREASED A
BIT FURTHER FOR THROUGH THIS TIME PERIOD...HOWEVER SLIGHT
DIFFERENCES REMAIN. THE GFS/NAM/EC SOLUTIONS 12Z/03 HAVE A SURFACE
LOW POSITIONED OVER THE SOUTHWEST CORNER OF MN...WHILE THE GEM HAS
BECOME THE MAIN OUTLIER...KEEPING THE SURFACE LOW FARTHER SOUTH OVER
SOUTHEASTERN NE. AT THE SAME TIME AN UPPER LEVEL 500MB CLOSED LOW IS
EXPECTED TO SLOWLY EJECT FROM THE NORTHERN ROCKIES TOWARD THE UPPER
MIDWEST. BY 18Z/03 THE GFS/EC HAVE THE SURFACE LOW SHIFTING
NORTHWARD TOWARD FAR WESTERN LAKE SUPERIOR. AS THIS HAPPENS A WARM
FRONT IS EXPECTED TO LIFT NORTHWARD...REACHING THE SOUTHERN HALF OF
UPPER MI BY 18Z TUES. ISENTROPIC UPGLIDE ALONG THIS FRONT ALONG WITH
INCREASED MOISTURE ON THE 295K ISOSURFACE WILL ALLOW PRECIPITATION
TO FORM AND SPREAD ACROSS MUCH OF THE U.P. BY 18Z/03. BY 06Z
WEDNESDAY THE GFS HAS THE SURFACE LOW DIRECTLY OVER THE WESTERN HALF
OF UPPER MI...WHILE THE 00Z RUN OF THE EC KEEPS THE LOW LESS INTENSE
AND FARTHER SOUTH OVER NORTHERN MO. IF THE GFS IS CORRECT
PRECIPITATION WOULD START EARLIER OVER THE U.P...WHILE THE EC WOULD
SLOW THE PRECIP DOWN BY ABOUT 6 HOURS. TRIED TO ACCOUNT FOR THE
DISCREPANCIES BY SLOWING THE ONSET OF LIKELIES BY A FEW HOURS. BOTH
THE GFS AND EC EVENTUALLY HAVE THE LOW CROSSING THE WESTERN HALF OF
THE U.P. WHICH WILL KEEP THE EASTERN HALF OF THE U.P. IN THE WARM
AIR ADVECTING INTO THE REGION ALONG WITH CONTINUED ISENTROPIC
UPGLIDE ACROSS THOSE AREAS...ALLOWING THE PRECIPITATION TO
TRANSITION INTO A RAIN SNOW MIXTURE DURING THAT TIME FRAME. THIS
WOULD HELP KEEP SNOWFALL TOTALS BELOW ADVISORY CRITERIA IN THOSE
AREAS. AS THE PREVIOUS SHIFT MENTIONED...AS THE SNOW TRANSITIONS TO
RAIN...THE POTENTIAL EXISTS FOR THE PRECIPITATION TO FREEZE ON BELOW
FREEZING/UNTREATED SURFACES CAUSING SLIPPERY CONDITIONS. THE FAR
WESTERN PORTION OF THE U.P. WILL LIKELY STAY COOL ENOUGH TO REMAIN
ALL SNOW THROUGH THIS EVENT...KEEPING THE POTENTIAL FOR AT LEAST
ADVISORY SNOW OVER THE FAR WESTERN COUNTIES FROM IWD TO NEAR COPPER
HARBOR. AT THIS POINT...WITH CONTINUED MODEL DISAGREEMENT...HAVE
DECIDED AGAINST A HEADLINE. BETWEEN 12Z/04 AND 00Z/05 THE LOW SHIFTS
TO NORTHERN LAKE SUPERIOR ALLOWING THE PRECIPITATION TO TAPER OFF
ACROSS MOST OF THE U.P. AS THE DRY SLOT AND COLD FRONT PASS THROUGH
THE AREA. THE BETTER FORCING AND MOISTURE AT THAT TIME WILL SHIFT
INTO ONTARIO. ANOTHER ISSUE THAT WILL COME ALONG WITH THIS SYSTEM
WILL BE THE POSSIBILITY OF EASTERLY GALE FORCE WINDS ON LAKE
SUPERIOR AS THE LOW INTENSIFIES AND SHIFTS INTO THE U.P. THE BEST
TIME FRAME FOR THIS TO OCCUR WOULD BE 00Z/04 THROUGH 12Z/04. 850MB
WINDS ARE PROGGED TO BE AROUND 30 KNOTS. WHILE TEMPERATURES ARE NOT
TERRIBLY COLD AT 850MB WITH TEMPS RUNNING AROUND 0C TO
-2C...HOWEVER...THIS MAY BE ENOUGH TO ALLOW THE STRONGER WINDS TO
MIX TO THE SURFACE OF THE LAKE AS THE LAKE SURFACE TEMPS ARE RUNNING
AROUND 4C TO 5C. AGAIN THIS IS LARGELY DEPENDENT UPON THE SYSTEM
STRENGTH AND TIMING...WITH BELOW AVERAGE CONFIDENCE.
THURSDAY THROUGH SUNDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME...HOWEVER
THE GFS IS STILL MORE PROGRESSIVE AND SLIGHT FARTHER NORTH THAN THE
EC. THE GFS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY
12Z THURSDAY...WHILE THE EC PLACES THE SURFACE LOW JUST SOUTH OF
JAMES BAY. EITHER WAY...THIS PLACES THE UPPER PENINSULA IN A
WESTERLY TO WEST NORTHWESTERLY FLOW. 850MB TEMPERATURES DURING THIS
TIME ARE EXPECTED TO DROP TO -11C TO -15C WITH LAKE SURFACE
TEMPERATURES AROUND 4C TO 5C. THIS WILL CREATE FAVORABLE CONDITIONS
FOR LAKE EFFECT SNOW TO DEVELOP ACROSS THE AREA. THE SURFACE LOW
WILL REMAIN NEARLY STATIONARY THROUGH SATURDAY AS ANOTHER UPPER
LEVEL 500MB TROUGH AXIS SWINGS INTO THE AREA FRIDAY NIGHT. THIS WILL
BRING SOME OF THE COLDEST AIR SO FAR THIS SEASON INTO THE AREA.
850MB TEMPS ARE PROGGED TO DROP TO AROUND -22C DURING THIS TIME
FRAME...AGAIN ALLOWING A CONTINUATION OF LAKE EFFECT SNOWFALL. HAVE
KEPT WITH THE LIKELY POPS ACROSS WESTERLY WIND FAVORED SNOW BELTS OF
THE U.P....HOWEVER...THIS EVENT WILL LIKELY BE A LONG DURATION EVENT
WITH MODERATE SNOWFALL TOTAL EXPECTED BY THE END OF THE EVENT.
AGAIN...IT IS LIKELY THAT LES WILL OCCUR...IT IS JUST UNLIKELY THAT
THE SNOWFALL RATES WILL BE UNUSUALLY HIGH AT THIS POINT AS THE MORE
FAVORABLE SNOW GROWTH ZONE WILL BE VERY SHALLOW AND INVERSION
HEIGHTS EXPECTED TO BE AROUND 5-6KFT...EVEN AFTER ADJUSTING FOR THE
WARMER LAKE SURFACE TEMPERATURES. THE SNOWFALL TOTALS AND EXACT
LOCATION OF THIS LONGER DURATION EVENT WILL CONTINUE TO BE FINE
TUNED AS THE WEEKEND APPROACHES. ANOTHER PERHAPS MORE DANGEROUS
ASPECT OF THIS WINTER WEATHER EVENT WILL BE THE POTENTIAL FOR A
DANGEROUSLY COLD AIRMASS TO BUILD INTO THE REGION THURSDAY NIGHT
THROUGH SATURDAY NIGHT. WITH 850MB TEMPS AROUND THE -22C MARK AS
PREVIOUSLY MENTION...LOW TEMPERATURES WILL LIKELY FALL INTO THE
TEENS BELOW ZERO WITH DAYTIME HIGHS ONLY REACHING INTO THE SINGLE
DIGITS ABOVE ZERO FOR WESTERN PORTIONS OF THE U.P. WINDS WILL ALSO
BE FAIRLY STRONG ALLOWING WIND CHILLS TO DROP AS LOW AS -30F DURING
THE OVERNIGHT HOURS THROUGH THIS TIME FRAME. SUNDAY MAY BEGIN TO
BRING A BIT OF RELIEF...HOWEVER...AS THE SURFACE LOW AND UPPER LEVEL
500MB TROUGH NEAR JAMES BAY FINALLY BEGINS TO SHIFT EASTWARD. THIS
WILL SLOWLY DIMINISH THE CHANCE OF LES AS A BRIEF RIDGE BUILDS. THIS
WILL ALSO ALLOW TEMPERATURES TO MODERATE SLIGHTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON DEC 2 2013
DISTURBANCE APPROACHING FROM THE NRN PLAINS WILL SPREAD -SN FROM W
TO E ACROSS THE AREA THIS AFTN AND TONIGHT. PRIOR TO THE ARRIVAL OF
-SN...VFR CONDITIONS WILL PREVAIL...THOUGH DEVELOPING UPSLOPE
FLOW WILL PROBABABLY LEAD TO MFVR CIGS DEVELOPING AT KCMX/KSAW LATER
THIS AFTN/EARLY THIS EVENING...WELL BEFORE THE ONSET OF -SN AT THOSE
TERMINALS. SEVERAL HRS AFTER THE -SN BEGINS AT EACH TERMINAL...
CONDITIONS WILL DETERIORATE TO IFR. MAY SEE SOME IMPROVEMENT AT KIWD
TUE MORNING AS STEADIER -SN SHIFTS E AND NE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 PM EST MON DEC 2 2013
AS LOW PRES BEGINS TO ORGANIZE IN THE PLAINS AND HIGH PRES BUILDS
ACROSS CNTRL CANADA AND INTO NRN ONTARIO...E TO SE WINDS WILL BE ON
THE INCREASE TONIGHT...AND E WINDS WILL INCREASE FURTHER TUE. EXPECT
WINDS TO REACH GALE FORCE OVER WRN LAKE SUPERIOR TUE AFTN THU WED
MORNING AS TERRAIN SURROUNDING THE LAKE ENHANCES THE E FLOW. THE LOW
WILL MOVE ACROSS THE UPPER GREAT LAKES LATE WED. IN THE WAKE OF THE
LOW...VERY COLD AIR ADVECTING OVER THE RELATIVELY WARM WATERS WILL
INCREASE INSTABILITY AND RESULT IN W TO NW GALES AT TIMES FOR
PORTIONS OF LAKE SUPERIOR WED NIGHT/THU. CONTINUED FLOW OF VERY COLD
AIR MAY RESULT IN PERIODIC GALES EVEN THRU FRI/SAT. BUILDING WAVES
AND THE ARRIVAL OF THE ARCTIC AIR WILL ALSO CAUSE INCREASING
FREEZING SPRAY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 1 PM EST /NOON CST/ TUESDAY TO 10 AM EST /9 AM
CST/ WEDNESDAY FOR LSZ162.
GALE WARNING FROM 4 PM TUESDAY TO 10 AM EST WEDNESDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
AVIATION...ROLFSON
LONG TERM...KEC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GAYLORD MI
135 PM EST MON DEC 2 2013
.SYNOPSIS...
ISSUED AT 300 AM EST MON DEC 2 2013
WEAK HIGH PRESSURE OVER THE WESTERN GREAT LAKES REGION WILL KEEP OUR
WEATHER DRY BUT CLOUDY TODAY. PRECIPITATION CHANCES WILL INCREASE
TUESDAY AS A WARM FRONT LIFTS THROUGH MICHIGAN...WITH A MIX OF RAIN
AND SNOW EVENTUALLY CHANGING OVER TO ALL RAIN ON WEDNESDAY.
PRECIPITATION WILL CHANGE BACK OVER TO ALL SNOW WEDNESDAY NIGHT AS A
COLD FRONT BLASTS THROUGH THE REGION.
&&
.UPDATE...
ISSUED AT 134 PM EST MON DEC 2 2013
BATCH OF LIGHT FLURRIES/DRIZZLE...SEEMINGLY LAKE INDUCED...CONTINUES AT
THIS HOUR OVER THE TIP OF THE MITT COUNTIES. LAKE MESO-LOW ALSO
CONTINUES TO SPIN JUST OFF LEELANAU COUNTY. HAS CLEARED OUT FAIRLY
WELL OVER EASTERN UPPER MICHIGAN BUT QUITE A BIT OF LOWER CLOUD
COVER STILL DRAPED OVER NRN LOWER MICHIGAN. REST OF THE
AFTERNOON...WHAT YOU SEE IS WHAT YOU GET PRETTY MUCH. HAVE TWEAKED
SKY/WEATHER FORECASTS TO ADJUST FOR TRENDS.
UPDATE ISSUED AT 944 AM EST MON DEC 2 2013
BROAD HIGH PRESSURE IN PLACE ACROSS THE GREAT LAKES THIS MORNING.
GENERALLY QUIET...BUT THERE IS A SUBTLE SHORT WAVE TROUGH MOVING
THROUGH THE REGION THAT HAS BROUGHT ABOUT A SUBTLE BUMP UP IN
INVERSION HEIGHTS AND WEAK UPWARD FORCING. ENOUGH TO PRODUCE A
HYBRID BROAD AREA OF LAKE INDUCED/SYNOPTIC LIGHT PRECIP ACROSS
PARTS OF THE CWA. MAINLY FLURRIES AS INVERSION HEIGHTS ARE JUST UP
INTO THE -12C/-13C RANGE...ALTHOUGH THERE MIGHT BE SOME
INTERMINGLED -FZDZ AS WELL.
HAVE EXTENDED FLURRIES/LIGHT FREEZING DRIZZLE OUT THROUGH THE REST
OF THE MORNING. RUC13 DATA THEN SUGGESTS FORCING WILL FALL APART
BY EARLY AFTERNOON AND WE SHOULD SEE A DOWNWARD TREND TO THE
LIGHT/NUISANCE PRECIP. WILL SEE.
UPDATE ISSUED AT 619 AM EST MON DEC 2 2013
PATCHY FREEZING DRIZZLE HAS EXPANDED ACROSS THE STRAITS AND FAR
NRN LWR MICHIGAN EARLY THIS MORNING PER LATEST KAPX 88D BASE REF
LOOP. SURFACE OBS HAVE YET TO REPORT THIS PHENOMENA...BUT A COUPLE
OF EARLY MORNING SPOTTER REPORTS CONFIRM THAT SOME VERY LIGHT
PRECIP IS REACHING THE GROUND. HAVE SPREAD PATCHY FREEZING DRIZZLE
INTO THESE AREAS AND HAVE EXTENDED THE OCCURRENCE THRU 15Z AS
SHALLOW LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE SUBSIDENCE
INVERSION AND SOME VERY WEAK SHEAR CONTINUES AT THE TOP OF THE
MOIST LAYER. REST OF THE DAY WILL BE CLOUDY WITH TEMPS ONLY
WARMING INTO THE LOW TO MID 30S.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM EST MON DEC 2 2013
KINDA "DIRTY" HIGH PRESSURE EXTENDING ACROSS THE NORTH WOODS AT THIS
EARLY HOUR...WITH PLENTY OF CLOUDS STUCK BELOW STRONG H8 SUBSIDENCE
INVERSION (PER LOCAL 00Z SOUNDING). STILL SOME WEAK LAKE PROCESSES
ONGOING IN MARGINALLY COLD ENOUGH ATMOSPHERE...WITH EVEN A WELL
EVIDENT LAKE-INDUCED MESO LOW SPINNING HARMLESSLY ACROSS NORTHERN
LAKE MICHIGAN. ENOUGH LIFT/LAKE MOISTURE CONTRIBUTION TO KICK OFF A FEW
FLURRIES FOR SOME...BUT THAT`S ABOUT IT. MID AND UPPER LEVEL PATTERN
JUST ABOUT AS NONDESCRIPT AS THE SURFACE FEATURES...WITH GENERALLY
LIGHT WEST TO NORTHWEST FLOW ALOFT...WITH MUCH STRONGER JET ENERGY
WELL TO OUR WEST (LEADING CORE OF 100+ KNOT UPPER JET PUNCHING INTO
THE NORTHERN ROCKIES). JUST NOT A WHOLE LOT OF CHANGE EXPECTED
THROUGH THIS EVENING...WITH WAA PROCESSES RAMPING UP TOWARD TUESDAY
MORNING WELL AHEAD OF ORGANIZING CENTRAL PLAINS LOW PRESSURE.
THUS...FORECAST CONCERNS REMAIN RATHER TRIVIAL...CENTERING ON
CLOUD/TEMPERATURE TRENDS AS WELL AS SOME WEAK LAKE PROCESSES THROUGH
THIS EVENING. POSSIBLE LATE NIGHT WAA PRECIP WILL ALSO NEED
ADDRESSING.
BASICALLY...WHAT YOU SEE IS WHAT YOU GET TODAY. HAVING A HARD TIME
BELIEVING RATHER AGGRESSIVE DRYING BELOW INVERSION LEVEL NOTED IN
MODEL DERIVED SOUNDINGS. NAM-BUFR INITIATION FAR TOO DRY ALREADY AT
INVERSION LEVEL...AND GIVEN VERY LIGHT WIND FIELDS TODAY (SIMPLY NO
MECHANICAL MIXING)...FEEL CURRENT CLOUD DECK WILL BE AWFULLY HARD
TO "BURN" OFF. WILL CONTINUE TO TREND MORE PESSIMISTICALLY WITH
CLOUD COVER...JUST FEATURING A FEW AFTERNOON BREAKS...BUT STILL
CALLING IT MOSTLY CLOUDY. ONLY PRECIP CONCERNS APPEARS TIED TO
NORTHWEST PUSH OF CURRENT NORTHERN LAKE MICHIGAN MESO-LOW. WILL
INTRODUCE FLURRY WORDING INTO MACKINAC COUNTY THIS MORNING AS THIS
FEATURE MOVES ASHORE. OTHERWISE...DESPITE THE CLOUDY DAY...DRY
CONDITIONS LOOK TO PREVAIL. NOT A WHOLE LOT OF DIURNAL TEMPERATURE
RESPONSE...WITH AFTERNOON READINGS RUNNING IN THE LOWER AND MIDDLE
30S.
STATUS-QUO THROUGH THIS EVENING...WITH PERHAPS A FEW MORE BREAKS
IN THE OVERCAST BEFORE HIGH LEVEL CLOUDS SPREAD ACROSS THE REGION IN
DEVELOPING TOP-DOWN SATURATION REGIME. GUIDANCE TRYING TO SATURATE
THE COLUMN RIGHT TOWARDS SUNRISE DOWN NEAR MANISTEE AS ISENTROPIC
UPGLIDE INCREASES AHEAD OF DEVELOPING CENTRAL PLAINS STORM SYSTEM.
MAIN SHOW SHOULD REMAIN OFF TO OUR WEST...BUT CANNOT COMPLETELY RULE
OUT SOME LIGHT SNOWS BY SUNRISE ACROSS THE FAR SOUTHWEST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 300 AM EST MON DEC 2 2013
TUESDAY AND WEDNESDAY...WEATHER BECOMES MORE ACTIVE TUESDAY AHEAD OF
A WARM FRONT LIFTING INTO THE WRN GREAT LAKES REGION. THIS FRONT IS
ASSOCIATED WITH DEEPENING LOW PRESSURE IN THE NRN PLAINS. EASTERLY
LOW LEVEL WINDS WILL GRADUALLY SHIFT SE ON TUESDAY AS THE WARM FRONT
NEARS...AND THEN TO THE SOUTH ON WEDNESDAY ONCE THE WARM FRONT LIFTS
NORTH OF OUR CWA. WARMER AIR WILL STEADILY SURGE NORTHWARD THRU OUR
CWA BEGINNING TUESDAY MORNING AND CONTINUING THRU MUCH OF WEDNESDAY.
850 MB TEMPS WILL WARM FROM ROUGHLY -4 C ACROSS NRN LWR MICHIGAN AT
12Z TUESDAY TO 6 C BY 12Z WEDNESDAY. PERSISTENT LOW CLOUDS WILL
LIMIT THE AFFECTS OF WAA AT THE SURFACE. AS THE LOW LEVEL TEMP
PROFILE CHANGES...SO WILL PRECIP TYPE AS MOISTURE AND THUS POPS
GRADUALLY INCREASE FROM SW TO NE ACROSS OUR CWA ON TUESDAY. WILL
NEED TO WATCH MODEL SOUNDINGS CLOSELY FOR THE POSSIBILITY OF SOME
SLEET OR FREEZING RAIN TUESDAY AND TUESDAY NIGHT AS WARMER AIR ALOFT
GRADUALLY WORKS ITS WAY NORTHWARD BEFORE THE BOUNDARY LAYER HAS A
CHANCE TO FULLY REALIZE THE WAA. FOR NOW...WILL KEEP PRECIP TYPE
SIMPLE GIVEN ALL OF THE UNKNOWNS THIS FAR OUT. PRECIP TYPE SHOULD
INITIALLY BE ALL SNOW...CHANGING TO A MIX OF RAIN AND SNOW...AND
EVENTUALLY ALL RAIN AS WAA WORKS ITS WAY NORTHWARD THRU OUR CWA
TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...PRECIP TYPE SHOULD BE ALL
RAIN ACROSS OUR ENTIRE CWA. LATEST NAM CONTINUES TO BE MORE
AGGRESSIVE WITH COLD FROPA...NOW BRINGING THE COLD AIR BACK INTO THE
REGION WEDNESDAY NIGHT. EXPECT RAIN WILL MIX WITH AND CHANGE BACK
OVER TO SNOW FROM NW TO SE DURING THE EVENING...WITH ALL SNOW
EXPECTED BY LATE WEDNESDAY NIGHT AS 850 MB TEMPS COOL BACK TO -4 C
BY 12Z THURSDAY. GIVEN THIS SCENARIO...HIGH TEMPS MAINLY IN THE 30S
ON TUESDAY WILL WARM INTO THE UPPER 30S AND LOWER 40S FOR WEDNESDAY
WHEN WAA WILL PEAK. OVERNIGHT LOWS TUESDAY NIGHT WILL ONLY COOL A
FEW DEGREES...DROPPING BACK INTO THE UPPER 20S TO MID 30S. TEMPS
WILL FALL BACK INTO THE 20S WEDNESDAY NIGHT AS CAA COMMENCES.
THURSDAY THRU SUNDAY...CAA CONTINUES THURSDAY AND FRIDAY AS 850 MB
TEMPS FURTHER COOL TO -20 C BY 00Z SATURDAY. LATEST ECMWF SHOWS
WESTERLY LOW LEVEL FLOW SETTING UP THURSDAY IN THE WAKE OF THE COLD
FRONT...WITH VERY LITTLE CHANGE IN THIS TRAJECTORY THRU SATURDAY
NIGHT. THIS COULD SET THE STAGE FOR A PROLONGED WESTERLY FLOW LAKE
EFFECT SNOW EVENT FOR THE LAST PART OF THE WEEK. THIS POTENTIAL
EVENT IS STILL SEVERAL DAYS OUT WITH TOO MANY UNKNOWNS TO GET TOO
SPECIFIC OR DETAILED AT THIS TIME. WILL CERTAINLY KEEP A CLOSE EYE
ON SUBSEQUENT MODEL RUNS TO SEE HOW THIS SCENARIO EVOLVES. FOR
NOW...WILL HIGHLIGHT HIGHEST POPS ACROSS OUR WESTERLY FLOW AREAS OF
ERN UPR AND NW/N CENTRAL LWR MICHIGAN. SUNDAY LOOKS LIKE A
TRANSITION DAY AS LOW LEVEL FLOW SHIFTS TO THE SOUTH AHEAD OF OUR
NEXT LOW PRESSURE SYSTEM. INCREASING SYNOPTIC LIFT AND MOISTURE ON
SUNDAY SHOULD BRING MORE WIDESPREAD SNOWS TO ALL OF NORTHERN
MICHIGAN. WITH PROGRESSIVE CAA TAKING PLACE THRU THIS TIME...
AFTERNOON HIGHS WILL COOL FROM THE LOWER 30S ON THURSDAY TO THE
UPPER TEENS TO MID 20S FOR SATURDAY. LOW TEMPS WILL BE MAINLY IN THE
TEENS FOR THE LAST PART OF THE WEEK AND THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 134 PM EST MON DEC 2 2013
MAINLY VFR CIGS ACROSS NRN LOWER MICHIGAN THIS AFTERNOON...AND
EXPECTED TO PERSIST THROUGH THE REST OF THE AFTERNOON AND A GOOD
PART OF TONIGHT. NEARLY CALM WINDS ANTICIPATED THROUGH TONIGHT.
AREA OF LOW PRESSURE IN THE PLAINS WILL ORGANIZE TONIGHT AND BEGIN
TO EDGE INTO THE GREAT LAKES TUESDAY. ASSOCIATED WARM FRONT WILL
LIFT INTO THE LOWER LAKES REGION AND EVENTUALLY DRIVE A CORRIDOR
OF PRECIP INTO NRN MICHIGAN...MAINLY TUESDAY AFTERNOON. CIGS WILL
LOWER TO MVFR TUESDAY MORNING AND THERE MAY BE A PERIOD -FZDZ
DURING THE MORNING AS LOW LEVEL MOISTURE DEEPENS.
&&
.MARINE...
ISSUED AT 300 AM EST MON DEC 2 2013
LIGHT WINDS CONTINUE THROUGH THIS EVENING AS WEAK SURFACE
RIDGE CUTS THROUGH THE AREA. EAST TO SOUTHEAST WINDS BEGIN TO PICK
UP TONIGHT WELL AHEAD OF LOW PRESSURE ORGANIZING OVER THE CENTRAL
PLAINS. STRONGER SOUTHEAST WINDS ARRIVE TUESDAY AND TUESDAY
NIGHT...WITH SOME SCA/S POSSIBLE DURING THIS PERIOD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...BA
SYNOPSIS...MR
SHORT TERM...MB
LONG TERM...MR
AVIATION...BA
MARINE...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1241 PM EST MON DEC 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EST MON DEC 2 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A RELATIVELY LGT
ZONAL FLOW OVER THE UPR GRT LKS TO THE N OF THE MAIN POLAR JET OVER
THE SRN CONUS. AT THE SFC...HI PRES IS PRESENT NEAR JAMES BAY...WITH
A WEAK LO PRES TROF ORIENTED WNW TO ESE OVER UPR MI. THIS TROF HAS
BEEN THE FOCUS FOR SOME LGT -SN MIXED AT TIMES WITH -FZDZ DESPITE
RELATIVELY HI CIGS ASSOCIATED WITH A BIT OF DRIER LLVL AIR SHOWN ON
THE LOCAL 00Z RAOBS BLO SUBSIDENCE INVRN BASE JUST ABV H85. H85
TEMPS ARND -9C RELATIVE TO LK SUP TEMPS ARND 4C HAVE ALSO LIMITED
THE SN INTENSITY. GIVEN THE VERY LGT WIND FIELDS...SFC WINDS AS WELL
AS MQT RADAR IMAGERY INDICATE SOME VORTICES HAVE FORMED OVER THE
RELATIVELY WARM LK WATERS...WITH ONE CENTERED JUST E OF KEWEENAW BAY
AND ANOTHER N OF MUNISING. THERE APPEARS TO BE ANOTHER ONE OVER NRN
LK MI...WHERE THE OPEN WATER TEMP OF 7C REPORTED BY THE 45002 BUOY
AT THE NRN END OF THE LK IS ALLOWING A BIT MORE OVERWATER
INSTABILITY. SINCE THE SFC HI NEAR JAMES BAY IS DRIFTING TO THE
E...THE LLVL WINDS HAVE TENDED TO VEER MORE TO THE S-SW PER THE MQT
88D VWP...ESPECIALLY OVER THE W HALF OF THE CWA. THIS WSHFT IS
CAUSING THE RADAR ECHOES TO DRIFT SLOWLY TO THE N. THIS FLOW ALSO
APPEARS TO BE ADVECTING EVEN DRIER LLVL AIR SHOWN ON THE 00Z MPX AND
QUAD CITIES IA RAOBS TO THE N. ALTHOUGH LOTS OF SC LINGER OVER NRN
WI...THERE HAS BEEN PARTIAL CLRG OVER THE CENTRAL PART OF WI. BUT
MORE WAD CLDS ASSOCIATED WITH ISENTROPIC ASCENT BTWN THE DEPARTING
HI AND LOWER PRES IN THE NRN PLAINS AND BEST DEPICTED ON THE
285-295K SFCS /H85-65/ IS SPREADING QUICKLY TO THE E THRU MN AND
INTO WRN WI. THERE HAS EVEN BEEN SOME -SN AS FAR E AS CNTRL MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LINGERING CHCS FOR -SHSN/
-FZDZ TDAY. FOCUS FOR LATER TODAY AND TNGT SHIFTS TO POPS FOR SN
ASSOCIATED WITH THE ISENTROPIC LIFT SPREADING IN FM THE W.
TODAY...WITH THE CONTINUED TREND FOR THE H925 WINDS TO SHIFT TO THE
S THIS MRNG AND CAUSE THE LO PRES TROF TO DRIFT TO THE N...EXPECT
THE BULK OF LINGERING PCPN OVER UPR MI TO MOVE INTO LK SUP. THE BEST
CHC FOR MORE PCPN MAY BE OVER THE SE COUNTIES AS THE VORTEX NOW
PRESENT OVER NRN LK MI DRIFTS INLAND AS SHOWN BY A NUMBER OF THE HI
RES MODELS. THE QPF FM SOME OF THESE MODELS INDICATES THERE COULD BE
A FEW INCHES OF SN IN THIS AREA...BUT PRESENCE OF THE DGZ ABV THE
MOIST LYR/SHARPER LLVL UVV MAX AS WELL AS MARGINAL OVERWATER
INSTABILITY WITH H85 TEMPS PROGGED TO WARM TOWARD -7 TO -8C BY 00Z
SUG THE PCPN WL BE RELATIVELY LGT AND POSSIBLY EVEN MIXED WITH SOME
-FZDZ. ALTHOUGH THE DRIER NEAR SFC AIR BRINGING CLRG TO PORTIONS OF
CENTRAL WI MAY DRIFT A BIT FARTHER TO THE N THIS MRNG...A TREND FOR
THE SFC-H925 WINDS TO BACK TO THE SE THIS AFTN AND UPSLOPE OFF LK MI
WL LIKELY LIMIT ANY CLRG THAT MIGHT BRIEFLY IMPACT THE FAR SCENTRAL.
THE NAM ALSO SHOWS HIER MID LVL RH ON THE 285-295K SFCS PUSHING INTO
THE W HALF OF THE CWA DURING THE AFTN EVEN THOUGH THE ISENTROPIC
ASCENT APPEARS TO WEAKEN WITH TIME. WL RETAIN CHC POPS OVER THE FAR
W LATER IN THE DAY TO REFLECT THE POTENTIAL FOR SOME OF THE LGT -SN
NOW SHOWING UP AT SOME PLACES IN MN TO IMPACT THAT AREA.
TNGT...MOST OF THE NUMERICAL GUIDANCE SPREADS THE WAD PCPN INTO THE
WRN CWA TNGT WITH THE ARRIVAL OF H85-5 QVECTOR CVNGC AS WELL AS SOME
UPR DVGC IN THE LEFT EXIT REGION OF AN UPR JET SHIFTING E AWAY FM AN
UPR TROF THAT IS FCST TO DEEPEN OVER THE W. THE GFS IS STRONGEST
WITH THIS UPR DVGC AND THE ISENTROPIC ASCENT...GENERATING UP TO 0.75
INCH OF WATER EQUIVALENT PCPN AT IWD BY 12Z TUE...WHERE THE MODEL
ALSO SHOWS A CENTER OF STRONGER H85-7 FGEN. THE BULK OF THE OTHER
MODELS APPEAR TO FOCUS THE BETTER ISENTROPIC ASCENT TO THE S AND
SPIT OUT MUCH LESS PCPN...GENERALLY 0.10 TO 0.30 INCH IN THIS AREA.
CONSIDERING THE DRIER NATURE OF THE AIR TO THE S AND NCEP PREFERENCE
FOR A NON-GFS EVOLUTION...THE LOWER QPF SEEMS MORE RSNBL. BUT DID
BUMP POPS UP TO LIKELY IN THIS AREA...WITH CHC POPS DIMINISHING TO A
DRY FCST OVER THE E.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 505 AM EST MON DEC 2 2013
VERY CHALLENGING FORECAST IN STORE FOR THE TUESDAY THROUGH WEDNESDAY
NIGHT TIME FRAME. BEHIND THIS SYSTEM...LAKE EFFECT SNOW AND WELL
BELOW NORMAL TEMPERATURES ARE EXPECTED TO MOVE IN FOR THE LAST HALF
OF THE WORK WEEK INTO THE WEEKEND WITH DANGEROUS WIND CHILLS
EXPECTED TO APPROACH -30F BY FRIDAY NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...MODEL AGREEMENT HAS INCREASED A
BIT FURTHER FOR THROUGH THIS TIME PERIOD...HOWEVER SLIGHT
DIFFERENCES REMAIN. THE GFS/NAM/EC SOLUTIONS 12Z/03 HAVE A SURFACE
LOW POSITIONED OVER THE SOUTHWEST CORNER OF MN...WHILE THE GEM HAS
BECOME THE MAIN OUTLIER...KEEPING THE SURFACE LOW FARTHER SOUTH OVER
SOUTHEASTERN NE. AT THE SAME TIME AN UPPER LEVEL 500MB CLOSED LOW IS
EXPECTED TO SLOWLY EJECT FROM THE NORTHERN ROCKIES TOWARD THE UPPER
MIDWEST. BY 18Z/03 THE GFS/EC HAVE THE SURFACE LOW SHIFTING
NORTHWARD TOWARD FAR WESTERN LAKE SUPERIOR. AS THIS HAPPENS A WARM
FRONT IS EXPECTED TO LIFT NORTHWARD...REACHING THE SOUTHERN HALF OF
UPPER MI BY 18Z TUES. ISENTROPIC UPGLIDE ALONG THIS FRONT ALONG WITH
INCREASED MOISTURE ON THE 295K ISOSURFACE WILL ALLOW PRECIPITATION
TO FORM AND SPREAD ACROSS MUCH OF THE U.P. BY 18Z/03. BY 06Z
WEDNESDAY THE GFS HAS THE SURFACE LOW DIRECTLY OVER THE WESTERN HALF
OF UPPER MI...WHILE THE 00Z RUN OF THE EC KEEPS THE LOW LESS INTENSE
AND FARTHER SOUTH OVER NORTHERN MO. IF THE GFS IS CORRECT
PRECIPITATION WOULD START EARLIER OVER THE U.P...WHILE THE EC WOULD
SLOW THE PRECIP DOWN BY ABOUT 6 HOURS. TRIED TO ACCOUNT FOR THE
DISCREPANCIES BY SLOWING THE ONSET OF LIKELIES BY A FEW HOURS. BOTH
THE GFS AND EC EVENTUALLY HAVE THE LOW CROSSING THE WESTERN HALF OF
THE U.P. WHICH WILL KEEP THE EASTERN HALF OF THE U.P. IN THE WARM
AIR ADVECTING INTO THE REGION ALONG WITH CONTINUED ISENTROPIC
UPGLIDE ACROSS THOSE AREAS...ALLOWING THE PRECIPITATION TO
TRANSITION INTO A RAIN SNOW MIXTURE DURING THAT TIME FRAME. THIS
WOULD HELP KEEP SNOWFALL TOTALS BELOW ADVISORY CRITERIA IN THOSE
AREAS. AS THE PREVIOUS SHIFT MENTIONED...AS THE SNOW TRANSITIONS TO
RAIN...THE POTENTIAL EXISTS FOR THE PRECIPITATION TO FREEZE ON BELOW
FREEZING/UNTREATED SURFACES CAUSING SLIPPERY CONDITIONS. THE FAR
WESTERN PORTION OF THE U.P. WILL LIKELY STAY COOL ENOUGH TO REMAIN
ALL SNOW THROUGH THIS EVENT...KEEPING THE POTENTIAL FOR AT LEAST
ADVISORY SNOW OVER THE FAR WESTERN COUNTIES FROM IWD TO NEAR COPPER
HARBOR. AT THIS POINT...WITH CONTINUED MODEL DISAGREEMENT...HAVE
DECIDED AGAINST A HEADLINE. BETWEEN 12Z/04 AND 00Z/05 THE LOW SHIFTS
TO NORTHERN LAKE SUPERIOR ALLOWING THE PRECIPITATION TO TAPER OFF
ACROSS MOST OF THE U.P. AS THE DRY SLOT AND COLD FRONT PASS THROUGH
THE AREA. THE BETTER FORCING AND MOISTURE AT THAT TIME WILL SHIFT
INTO ONTARIO. ANOTHER ISSUE THAT WILL COME ALONG WITH THIS SYSTEM
WILL BE THE POSSIBILITY OF EASTERLY GALE FORCE WINDS ON LAKE
SUPERIOR AS THE LOW INTENSIFIES AND SHIFTS INTO THE U.P. THE BEST
TIME FRAME FOR THIS TO OCCUR WOULD BE 00Z/04 THROUGH 12Z/04. 850MB
WINDS ARE PROGGED TO BE AROUND 30 KNOTS. WHILE TEMPERATURES ARE NOT
TERRIBLY COLD AT 850MB WITH TEMPS RUNNING AROUND 0C TO
-2C...HOWEVER...THIS MAY BE ENOUGH TO ALLOW THE STRONGER WINDS TO
MIX TO THE SURFACE OF THE LAKE AS THE LAKE SURFACE TEMPS ARE RUNNING
AROUND 4C TO 5C. AGAIN THIS IS LARGELY DEPENDENT UPON THE SYSTEM
STRENGTH AND TIMING...WITH BELOW AVERAGE CONFIDENCE.
THURSDAY THROUGH SUNDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME...HOWEVER
THE GFS IS STILL MORE PROGRESSIVE AND SLIGHT FARTHER NORTH THAN THE
EC. THE GFS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY
12Z THURSDAY...WHILE THE EC PLACES THE SURFACE LOW JUST SOUTH OF
JAMES BAY. EITHER WAY...THIS PLACES THE UPPER PENINSULA IN A
WESTERLY TO WEST NORTHWESTERLY FLOW. 850MB TEMPERATURES DURING THIS
TIME ARE EXPECTED TO DROP TO -11C TO -15C WITH LAKE SURFACE
TEMPERATURES AROUND 4C TO 5C. THIS WILL CREATE FAVORABLE CONDITIONS
FOR LAKE EFFECT SNOW TO DEVELOP ACROSS THE AREA. THE SURFACE LOW
WILL REMAIN NEARLY STATIONARY THROUGH SATURDAY AS ANOTHER UPPER
LEVEL 500MB TROUGH AXIS SWINGS INTO THE AREA FRIDAY NIGHT. THIS WILL
BRING SOME OF THE COLDEST AIR SO FAR THIS SEASON INTO THE AREA.
850MB TEMPS ARE PROGGED TO DROP TO AROUND -22C DURING THIS TIME
FRAME...AGAIN ALLOWING A CONTINUATION OF LAKE EFFECT SNOWFALL. HAVE
KEPT WITH THE LIKELY POPS ACROSS WESTERLY WIND FAVORED SNOW BELTS OF
THE U.P....HOWEVER...THIS EVENT WILL LIKELY BE A LONG DURATION EVENT
WITH MODERATE SNOWFALL TOTAL EXPECTED BY THE END OF THE EVENT.
AGAIN...IT IS LIKELY THAT LES WILL OCCUR...IT IS JUST UNLIKELY THAT
THE SNOWFALL RATES WILL BE UNUSUALLY HIGH AT THIS POINT AS THE MORE
FAVORABLE SNOW GROWTH ZONE WILL BE VERY SHALLOW AND INVERSION
HEIGHTS EXPECTED TO BE AROUND 5-6KFT...EVEN AFTER ADJUSTING FOR THE
WARMER LAKE SURFACE TEMPERATURES. THE SNOWFALL TOTALS AND EXACT
LOCATION OF THIS LONGER DURATION EVENT WILL CONTINUE TO BE FINE
TUNED AS THE WEEKEND APPROACHES. ANOTHER PERHAPS MORE DANGEROUS
ASPECT OF THIS WINTER WEATHER EVENT WILL BE THE POTENTIAL FOR A
DANGEROUSLY COLD AIRMASS TO BUILD INTO THE REGION THURSDAY NIGHT
THROUGH SATURDAY NIGHT. WITH 850MB TEMPS AROUND THE -22C MARK AS
PREVIOUSLY MENTION...LOW TEMPERATURES WILL LIKELY FALL INTO THE
TEENS BELOW ZERO WITH DAYTIME HIGHS ONLY REACHING INTO THE SINGLE
DIGITS ABOVE ZERO FOR WESTERN PORTIONS OF THE U.P. WINDS WILL ALSO
BE FAIRLY STRONG ALLOWING WIND CHILLS TO DROP AS LOW AS -30F DURING
THE OVERNIGHT HOURS THROUGH THIS TIME FRAME. SUNDAY MAY BEGIN TO
BRING A BIT OF RELIEF...HOWEVER...AS THE SURFACE LOW AND UPPER LEVEL
500MB TROUGH NEAR JAMES BAY FINALLY BEGINS TO SHIFT EASTWARD. THIS
WILL SLOWLY DIMINISH THE CHANCE OF LES AS A BRIEF RIDGE BUILDS. THIS
WILL ALSO ALLOW TEMPERATURES TO MODERATE SLIGHTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON DEC 2 2013
DISTURBANCE APPROACHING FROM THE NRN PLAINS WILL SPREAD -SN FROM W
TO E ACROSS THE AREA THIS AFTN AND TONIGHT. PRIOR TO THE ARRIVAL OF
-SN...VFR CONDITIONS WILL PREVAIL...THOUGH DEVELOPING UPSLOPE
FLOW WILL PROBABABLY LEAD TO MFVR CIGS DEVELOPING AT KCMX/KSAW LATER
THIS AFTN/EARLY THIS EVENING...WELL BEFORE THE ONSET OF -SN AT THOSE
TERMINALS. SEVERAL HRS AFTER THE -SN BEGINS AT EACH TERMINAL...
CONDITIONS WILL DETERIORATE TO IFR. MAY SEE SOME IMPROVEMENT AT KIWD
TUE MORNING AS STEADIER -SN SHIFTS E AND NE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EST MON DEC 2 2013
A LIGHT S WIND TODAY WILL BACK TOWARD THE E AND INCREASE UP TO 30
KTS BY TUE AS THE PRES GRADIENT TIGHTENS OVER THE UPPER GREAT LAKES
BETWEEN DEPARTING HI PRES OVER SE CANADA AND A LO PRES SYSTEM MOVING
E FROM THE PLAINS. DEPENDING ON THE TRACK AND INTENSITY OF THIS
LO...THERE COULD BE SOME MARGINAL GALES ON TUE INTO TUE NIGHT...
ESPECIALLY WHERE THE TERRAIN SURROUNDING THE LAKE ENHANCES THE E
FLOW. ALTHOUGH WINDS WILL DIMINISH A BIT THRU WED AS THE LO AND
FLATTER GRADIENT MOVES OVERHEAD...EXPECT A STRONGER W WIND TO 30 TO
35 KTS TO DEVELOP FOLLOWING THE PASSAGE OF THE LO INTO ONTARIO ON
WED NIGHT/THU. SINCE THIS WIND WILL ADVECT VERY COLD AIR OVER THE
RELATIVELY WARM WATERS...INCREASING INSTABILITY WILL ENHANCE THE
WINDS AND LIKELY REQUIRE GALE WARNINGS THU THRU FRI FOR AT LEAST
PORTIONS OF THE BIG LAKE. INCREASING WAVES AND THE ARRIVAL OF THE
ARCTIC AIRMASS WILL ALSO CAUSE WIDESPREAD FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION..ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS GAYLORD MI
945 AM EST MON DEC 2 2013
.SYNOPSIS...
ISSUED AT 300 AM EST MON DEC 2 2013
WEAK HIGH PRESSURE OVER THE WESTERN GREAT LAKES REGION WILL KEEP OUR
WEATHER DRY BUT CLOUDY TODAY. PRECIPITATION CHANCES WILL INCREASE
TUESDAY AS A WARM FRONT LIFTS THROUGH MICHIGAN...WITH A MIX OF RAIN
AND SNOW EVENTUALLY CHANGING OVER TO ALL RAIN ON WEDNESDAY.
PRECIPITATION WILL CHANGE BACK OVER TO ALL SNOW WEDNESDAY NIGHT AS A
COLD FRONT BLASTS THROUGH THE REGION.
&&
.UPDATE...
ISSUED AT 944 AM EST MON DEC 2 2013
BROAD HIGH PRESSURE IN PLACE ACROSS THE GREAT LAKES THIS MORNING.
GENERALLY QUIET...BUT THERE IS A SUBTLE SHORT WAVE TROUGH MOVING
THROUGH THE REGION THAT HAS BROUGHT ABOUT A SUBTLE BUMP UP IN
INVERSION HEIGHTS AND WEAK UPWARD FORCING. ENOUGH TO PRODUCE A
HYBRID BROAD AREA OF LAKE INDUCED/SYNOPTIC LIGHT PRECIP ACROSS
PARTS OF THE CWA. MAINLY FLURRIES AS INVERSION HEIGHTS ARE JUST UP
INTO THE -12C/-13C RANGE...ALTHOUGH THERE MIGHT BE SOME
INTERMINGLED -FZDZ AS WELL.
HAVE EXTENDED FLURRIES/LIGHT FREEZING DRIZZLE OUT THROUGH THE REST
OF THE MORNING. RUC13 DATA THEN SUGGESTS FORCING WILL FALL APART
BY EARLY AFTERNOON AND WE SHOULD SEE A DOWNWARD TREND TO THE
LIGHT/NUISANCE PRECIP. WILL SEE.
UPDATE ISSUED AT 619 AM EST MON DEC 2 2013
PATCHY FREEZING DRIZZLE HAS EXPANDED ACROSS THE STRAITS AND FAR
NRN LWR MICHIGAN EARLY THIS MORNING PER LATEST KAPX 88D BASE REF
LOOP. SURFACE OBS HAVE YET TO REPORT THIS PHENOMENA...BUT A COUPLE
OF EARLY MORNING SPOTTER REPORTS CONFIRM THAT SOME VERY LIGHT
PRECIP IS REACHING THE GROUND. HAVE SPREAD PATCHY FREEZING DRIZZLE
INTO THESE AREAS AND HAVE EXTENDED THE OCCURRENCE THRU 15Z AS
SHALLOW LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE SUBSIDENCE
INVERSION AND SOME VERY WEAK SHEAR CONTINUES AT THE TOP OF THE
MOIST LAYER. REST OF THE DAY WILL BE CLOUDY WITH TEMPS ONLY
WARMING INTO THE LOW TO MID 30S.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM EST MON DEC 2 2013
KINDA "DIRTY" HIGH PRESSURE EXTENDING ACROSS THE NORTHWOODS AT THIS
EARLY HOUR...WITH PLENTY OF CLOUDS STUCK BELOW STRONG H8 SUBSIDENCE
INVERSION (PER LOCAL 00Z SOUNDING). STILL SOME WEAK LAKE PROCESSES
ONGOING IN MARGINALLY COLD ENOUGH ATMOSPHERE...WITH EVEN A WELL
EVIDENT LAKE-INDUCED MESO LOW SPINNING HARMLESSLY ACROSS NORTHERN
LAKE MICHIGAN. ENOUGH LIFT/LAKE MOISTURE CONTRIBUTION TO KICK OFF A FEW
FLURRIES FOR SOME...BUT THAT`S ABOUT IT. MID AND UPPER LEVEL PATTERN
JUST ABOUT AS NONDESCRIPT AS THE SURFACE FEATURES...WITH GENERALLY
LIGHT WEST TO NORTHWEST FLOW ALOFT...WITH MUCH STRONGER JET ENERGY
WELL TO OUR WEST (LEADING CORE OF 100+ KNOT UPPER JET PUNCHING INTO
THE NORTHERN ROCKIES). JUST NOT A WHOLE LOT OF CHANGE EXPECTED
THROUGH THIS EVENING...WITH WAA PROCESSES RAMPING UP TOWARD TUESDAY
MORNING WELL AHEAD OF ORGANIZING CENTRAL PLAINS LOW PRESSURE.
THUS...FORECAST CONCERNS REMAIN RATHER TRIVIAL...CENTERING ON
CLOUD/TEMPERATURE TRENDS AS WELL AS SOME WEAK LAKE PROCESSES THROUGH
THIS EVENING. POSSIBLE LATE NIGHT WAA PRECIP WILL ALSO NEED
ADDRESSING.
BASICALLY...WHAT YOU SEE IS WHAT YOU GET TODAY. HAVING A HARD TIME
BELIEVING RATHER AGGRESSIVE DRYING BELOW INVERSION LEVEL NOTED IN
MODEL DERIVED SOUNDINGS. NAM-BUFR INITIATION FAR TOO DRY ALREADY AT
INVERSION LEVEL...AND GIVEN VERY LIGHT WIND FIELDS TODAY (SIMPLY NO
MECHANICAL MIXING)...FEEL CURRENT CLOUD DECK WILL BE AWFULLY HARD
TO "BURN" OFF. WILL CONTINUE TO TREND MORE PESSIMISTICALLY WITH
CLOUD COVER...JUST FEATURING A FEW AFTERNOON BREAKS...BUT STILL
CALLING IT MOSTLY CLOUDY. ONLY PRECIP CONCERNS APPEARS TIED TO
NORTHWEST PUSH OF CURRENT NORTHERN LAKE MICHIGAN MESO-LOW. WILL
INTRODUCE FLURRY WORDING INTO MACKINAC COUNTY THIS MORNING AS THIS
FEATURE MOVES ASHORE. OTHERWISE...DESPITE THE CLOUDY DAY...DRY
CONDITIONS LOOK TO PREVAIL. NOT A WHOLE LOT OF DIURNAL TEMPERATURE
RESPONSE...WITH AFTERNOON READINGS RUNNING IN THE LOWER AND MIDDLE
30S.
STATUS-QUO THROUGH THIS EVENING...WITH PERHAPS A FEW MORE BREAKS
IN THE OVERCAST BEFORE HIGH LEVEL CLOUDS SPREAD ACROSS THE REGION IN
DEVELOPING TOP-DOWN SATURATION REGIME. GUIDANCE TRYING TO SATURATE
THE COLUMN RIGHT TOWARDS SUNRISE DOWN NEAR MANISTEE AS ISENTROPIC
UPGLIDE INCREASES AHEAD OF DEVELOPING CENTRAL PLAINS STORM SYSTEM.
MAIN SHOW SHOULD REMAIN OFF TO OUR WEST...BUT CANNOT COMPLETELY RULE
OUT SOME LIGHT SNOWS BY SUNRISE ACROSS THE FAR SOUTHWEST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 300 AM EST MON DEC 2 2013
TUESDAY AND WEDNESDAY...WEATHER BECOMES MORE ACTIVE TUESDAY AHEAD OF
A WARM FRONT LIFTING INTO THE WRN GREAT LAKES REGION. THIS FRONT IS
ASSOCIATED WITH DEEPENING LOW PRESSURE IN THE NRN PLAINS. EASTERLY
LOW LEVEL WINDS WILL GRADUALLY SHIFT SE ON TUESDAY AS THE WARM FRONT
NEARS...AND THEN TO THE SOUTH ON WEDNESDAY ONCE THE WARM FRONT LIFTS
NORTH OF OUR CWA. WARMER AIR WILL STEADILY SURGE NORTHWARD THRU OUR
CWA BEGINNING TUESDAY MORNING AND CONTINUING THRU MUCH OF WEDNESDAY.
850 MB TEMPS WILL WARM FROM ROUGHLY -4 C ACROSS NRN LWR MICHIGAN AT
12Z TUESDAY TO 6 C BY 12Z WEDNESDAY. PERSISTENT LOW CLOUDS WILL
LIMIT THE AFFECTS OF WAA AT THE SURFACE. AS THE LOW LEVEL TEMP
PROFILE CHANGES...SO WILL PRECIP TYPE AS MOISTURE AND THUS POPS
GRADUALLY INCREASE FROM SW TO NE ACROSS OUR CWA ON TUESDAY. WILL
NEED TO WATCH MODEL SOUNDINGS CLOSELY FOR THE POSSIBILITY OF SOME
SLEET OR FREEZING RAIN TUESDAY AND TUESDAY NIGHT AS WARMER AIR ALOFT
GRADUALLY WORKS ITS WAY NORTHWARD BEFORE THE BOUNDARY LAYER HAS A
CHANCE TO FULLY REALIZE THE WAA. FOR NOW...WILL KEEP PRECIP TYPE
SIMPLE GIVEN ALL OF THE UNKNOWNS THIS FAR OUT. PRECIP TYPE SHOULD
INITIALLY BE ALL SNOW...CHANGING TO A MIX OF RAIN AND SNOW...AND
EVENTUALLY ALL RAIN AS WAA WORKS ITS WAY NORTHWARD THRU OUR CWA
TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...PRECIP TYPE SHOULD BE ALL
RAIN ACROSS OUR ENTIRE CWA. LATEST NAM CONTINUES TO BE MORE
AGGRESSIVE WITH COLD FROPA...NOW BRINGING THE COLD AIR BACK INTO THE
REGION WEDNESDAY NIGHT. EXPECT RAIN WILL MIX WITH AND CHANGE BACK
OVER TO SNOW FROM NW TO SE DURING THE EVENING...WITH ALL SNOW
EXPECTED BY LATE WEDNESDAY NIGHT AS 850 MB TEMPS COOL BACK TO -4 C
BY 12Z THURSDAY. GIVEN THIS SCENARIO...HIGH TEMPS MAINLY IN THE 30S
ON TUESDAY WILL WARM INTO THE UPPER 30S AND LOWER 40S FOR WEDNESDAY
WHEN WAA WILL PEAK. OVERNIGHT LOWS TUESDAY NIGHT WILL ONLY COOL A
FEW DEGREES...DROPPING BACK INTO THE UPPER 20S TO MID 30S. TEMPS
WILL FALL BACK INTO THE 20S WEDNESDAY NIGHT AS CAA COMMENCES.
THURSDAY THRU SUNDAY...CAA CONTINUES THURSDAY AND FRIDAY AS 850 MB
TEMPS FURTHER COOL TO -20 C BY 00Z SATURDAY. LATEST ECMWF SHOWS
WESTERLY LOW LEVEL FLOW SETTING UP THURSDAY IN THE WAKE OF THE COLD
FRONT...WITH VERY LITTLE CHANGE IN THIS TRAJECTORY THRU SATURDAY
NIGHT. THIS COULD SET THE STAGE FOR A PROLONGED WESTERLY FLOW LAKE
EFFECT SNOW EVENT FOR THE LAST PART OF THE WEEK. THIS POTENTIAL
EVENT IS STILL SEVERAL DAYS OUT WITH TOO MANY UNKNOWNS TO GET TOO
SPECIFIC OR DETAILED AT THIS TIME. WILL CERTAINLY KEEP A CLOSE EYE
ON SUBSEQUENT MODEL RUNS TO SEE HOW THIS SCENARIO EVOLVES. FOR
NOW...WILL HIGHLIGHT HIGHEST POPS ACROSS OUR WESTERLY FLOW AREAS OF
ERN UPR AND NW/N CENTRAL LWR MICHIGAN. SUNDAY LOOKS LIKE A
TRANSITION DAY AS LOW LEVEL FLOW SHIFTS TO THE SOUTH AHEAD OF OUR
NEXT LOW PRESSURE SYSTEM. INCREASING SYNOPTIC LIFT AND MOISTURE ON
SUNDAY SHOULD BRING MORE WIDESPREAD SNOWS TO ALL OF NORTHERN
MICHIGAN. WITH PROGRESSIVE CAA TAKING PLACE THRU THIS TIME...
AFTERNOON HIGHS WILL COOL FROM THE LOWER 30S ON THURSDAY TO THE
UPPER TEENS TO MID 20S FOR SATURDAY. LOW TEMPS WILL BE MAINLY IN THE
TEENS FOR THE LAST PART OF THE WEEK AND THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 619 AM EST MON DEC 2 2013
LOW VFR CIGS WILL HOLD OVER ALL OF NRN LWR MICHIGAN THRU TUESDAY
MORNING AS SHALLOW LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE
SUBSIDENCE INVERSION. SOME PATCHY FREEZING DRIZZLE WILL IMPACT THE
REGION THIS MORNING...WILL LEAVE OUT OF THE TAF FOR NOW GIVEN THE
PATCHY NATURE OF THIS VERY LIGHT PRECIP. WINDS WILL REMAIN LIGHT
THRU THE FORECAST PERIOD.
&&
.MARINE...
ISSUED AT 300 AM EST MON DEC 2 2013
LIGHT WINDS CONTINUE THROUGH THIS EVENING AS WEAK SURFACE
RIDGE CUTS THROUGH THE AREA. EAST TO SOUTHEAST WINDS BEGIN TO PICK
UP TONIGHT WELL AHEAD OF LOW PRESSURE ORGANIZING OVER THE CENTRAL
PLAINS. STRONGER SOUTHEAST WINDS ARRIVE TUESDAY AND TUESDAY
NIGHT...WITH SOME SCA/S POSSIBLE DURING THIS PERIOD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...BA
SYNOPSIS...MR
SHORT TERM...MB
LONG TERM...MR
AVIATION...MR
MARINE...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
646 AM EST MON DEC 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EST MON DEC 2 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A RELATIVELY LGT
ZONAL FLOW OVER THE UPR GRT LKS TO THE N OF THE MAIN POLAR JET OVER
THE SRN CONUS. AT THE SFC...HI PRES IS PRESENT NEAR JAMES BAY...WITH
A WEAK LO PRES TROF ORIENTED WNW TO ESE OVER UPR MI. THIS TROF HAS
BEEN THE FOCUS FOR SOME LGT -SN MIXED AT TIMES WITH -FZDZ DESPITE
RELATIVELY HI CIGS ASSOCIATED WITH A BIT OF DRIER LLVL AIR SHOWN ON
THE LOCAL 00Z RAOBS BLO SUBSIDENCE INVRN BASE JUST ABV H85. H85
TEMPS ARND -9C RELATIVE TO LK SUP TEMPS ARND 4C HAVE ALSO LIMITED
THE SN INTENSITY. GIVEN THE VERY LGT WIND FIELDS...SFC WINDS AS WELL
AS MQT RADAR IMAGERY INDICATE SOME VORTICES HAVE FORMED OVER THE
RELATIVELY WARM LK WATERS...WITH ONE CENTERED JUST E OF KEWEENAW BAY
AND ANOTHER N OF MUNISING. THERE APPEARS TO BE ANOTHER ONE OVER NRN
LK MI...WHERE THE OPEN WATER TEMP OF 7C REPORTED BY THE 45002 BUOY
AT THE NRN END OF THE LK IS ALLOWING A BIT MORE OVERWATER
INSTABILITY. SINCE THE SFC HI NEAR JAMES BAY IS DRIFTING TO THE
E...THE LLVL WINDS HAVE TENDED TO VEER MORE TO THE S-SW PER THE MQT
88D VWP...ESPECIALLY OVER THE W HALF OF THE CWA. THIS WSHFT IS
CAUSING THE RADAR ECHOES TO DRIFT SLOWLY TO THE N. THIS FLOW ALSO
APPEARS TO BE ADVECTING EVEN DRIER LLVL AIR SHOWN ON THE 00Z MPX AND
QUAD CITIES IA RAOBS TO THE N. ALTHOUGH LOTS OF SC LINGER OVER NRN
WI...THERE HAS BEEN PARTIAL CLRG OVER THE CENTRAL PART OF WI. BUT
MORE WAD CLDS ASSOCIATED WITH ISENTROPIC ASCENT BTWN THE DEPARTING
HI AND LOWER PRES IN THE NRN PLAINS AND BEST DEPICTED ON THE
285-295K SFCS /H85-65/ IS SPREADING QUICKLY TO THE E THRU MN AND
INTO WRN WI. THERE HAS EVEN BEEN SOME -SN AS FAR E AS CNTRL MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LINGERING CHCS FOR -SHSN/
-FZDZ TDAY. FOCUS FOR LATER TODAY AND TNGT SHIFTS TO POPS FOR SN
ASSOCIATED WITH THE ISENTROPIC LIFT SPREADING IN FM THE W.
TODAY...WITH THE CONTINUED TREND FOR THE H925 WINDS TO SHIFT TO THE
S THIS MRNG AND CAUSE THE LO PRES TROF TO DRIFT TO THE N...EXPECT
THE BULK OF LINGERING PCPN OVER UPR MI TO MOVE INTO LK SUP. THE BEST
CHC FOR MORE PCPN MAY BE OVER THE SE COUNTIES AS THE VORTEX NOW
PRESENT OVER NRN LK MI DRIFTS INLAND AS SHOWN BY A NUMBER OF THE HI
RES MODELS. THE QPF FM SOME OF THESE MODELS INDICATES THERE COULD BE
A FEW INCHES OF SN IN THIS AREA...BUT PRESENCE OF THE DGZ ABV THE
MOIST LYR/SHARPER LLVL UVV MAX AS WELL AS MARGINAL OVERWATER
INSTABILITY WITH H85 TEMPS PROGGED TO WARM TOWARD -7 TO -8C BY 00Z
SUG THE PCPN WL BE RELATIVELY LGT AND POSSIBLY EVEN MIXED WITH SOME
-FZDZ. ALTHOUGH THE DRIER NEAR SFC AIR BRINGING CLRG TO PORTIONS OF
CENTRAL WI MAY DRIFT A BIT FARTHER TO THE N THIS MRNG...A TREND FOR
THE SFC-H925 WINDS TO BACK TO THE SE THIS AFTN AND UPSLOPE OFF LK MI
WL LIKELY LIMIT ANY CLRG THAT MIGHT BRIEFLY IMPACT THE FAR SCENTRAL.
THE NAM ALSO SHOWS HIER MID LVL RH ON THE 285-295K SFCS PUSHING INTO
THE W HALF OF THE CWA DURING THE AFTN EVEN THOUGH THE ISENTROPIC
ASCENT APPEARS TO WEAKEN WITH TIME. WL RETAIN CHC POPS OVER THE FAR
W LATER IN THE DAY TO REFLECT THE POTENTIAL FOR SOME OF THE LGT -SN
NOW SHOWING UP AT SOME PLACES IN MN TO IMPACT THAT AREA.
TNGT...MOST OF THE NUMERICAL GUIDANCE SPREADS THE WAD PCPN INTO THE
WRN CWA TNGT WITH THE ARRIVAL OF H85-5 QVECTOR CVNGC AS WELL AS SOME
UPR DVGC IN THE LEFT EXIT REGION OF AN UPR JET SHIFTING E AWAY FM AN
UPR TROF THAT IS FCST TO DEEPEN OVER THE W. THE GFS IS STRONGEST
WITH THIS UPR DVGC AND THE ISENTROPIC ASCENT...GENERATING UP TO 0.75
INCH OF WATER EQUIVALENT PCPN AT IWD BY 12Z TUE...WHERE THE MODEL
ALSO SHOWS A CENTER OF STRONGER H85-7 FGEN. THE BULK OF THE OTHER
MODELS APPEAR TO FOCUS THE BETTER ISENTROPIC ASCENT TO THE S AND
SPIT OUT MUCH LESS PCPN...GENERALLY 0.10 TO 0.30 INCH IN THIS AREA.
CONSIDERING THE DRIER NATURE OF THE AIR TO THE S AND NCEP PREFERENCE
FOR A NON-GFS EVOLUTION...THE LOWER QPF SEEMS MORE RSNBL. BUT DID
BUMP POPS UP TO LIKELY IN THIS AREA...WITH CHC POPS DIMINISHING TO A
DRY FCST OVER THE E.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 505 AM EST MON DEC 2 2013
VERY CHALLENGING FORECAST IN STORE FOR THE TUESDAY THROUGH WEDNESDAY
NIGHT TIME FRAME. BEHIND THIS SYSTEM...LAKE EFFECT SNOW AND WELL
BELOW NORMAL TEMPERATURES ARE EXPECTED TO MOVE IN FOR THE LAST HALF
OF THE WORK WEEK INTO THE WEEKEND WITH DANGEROUS WIND CHILLS
EXPECTED TO APPROACH -30F BY FRIDAY NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...MODEL AGREEMENT HAS INCREASED A
BIT FURTHER FOR THROUGH THIS TIME PERIOD...HOWEVER SLIGHT
DIFFERENCES REMAIN. THE GFS/NAM/EC SOLUTIONS 12Z/03 HAVE A SURFACE
LOW POSITIONED OVER THE SOUTHWEST CORNER OF MN...WHILE THE GEM HAS
BECOME THE MAIN OUTLIER...KEEPING THE SURFACE LOW FARTHER SOUTH OVER
SOUTHEASTERN NE. AT THE SAME TIME AN UPPER LEVEL 500MB CLOSED LOW IS
EXPECTED TO SLOWLY EJECT FROM THE NORTHERN ROCKIES TOWARD THE UPPER
MIDWEST. BY 18Z/03 THE GFS/EC HAVE THE SURFACE LOW SHIFTING
NORTHWARD TOWARD FAR WESTERN LAKE SUPERIOR. AS THIS HAPPENS A WARM
FRONT IS EXPECTED TO LIFT NORTHWARD...REACHING THE SOUTHERN HALF OF
UPPER MI BY 18Z TUES. ISENTROPIC UPGLIDE ALONG THIS FRONT ALONG WITH
INCREASED MOISTURE ON THE 295K ISOSURFACE WILL ALLOW PRECIPITATION
TO FORM AND SPREAD ACROSS MUCH OF THE U.P. BY 18Z/03. BY 06Z
WEDNESDAY THE GFS HAS THE SURFACE LOW DIRECTLY OVER THE WESTERN HALF
OF UPPER MI...WHILE THE 00Z RUN OF THE EC KEEPS THE LOW LESS INTENSE
AND FARTHER SOUTH OVER NORTHERN MO. IF THE GFS IS CORRECT
PRECIPITATION WOULD START EARLIER OVER THE U.P...WHILE THE EC WOULD
SLOW THE PRECIP DOWN BY ABOUT 6 HOURS. TRIED TO ACCOUNT FOR THE
DISCREPANCIES BY SLOWING THE ONSET OF LIKELIES BY A FEW HOURS. BOTH
THE GFS AND EC EVENTUALLY HAVE THE LOW CROSSING THE WESTERN HALF OF
THE U.P. WHICH WILL KEEP THE EASTERN HALF OF THE U.P. IN THE WARM
AIR ADVECTING INTO THE REGION ALONG WITH CONTINUED ISENTROPIC
UPGLIDE ACROSS THOSE AREAS...ALLOWING THE PRECIPITATION TO
TRANSITION INTO A RAIN SNOW MIXTURE DURING THAT TIME FRAME. THIS
WOULD HELP KEEP SNOWFALL TOTALS BELOW ADVISORY CRITERIA IN THOSE
AREAS. AS THE PREVIOUS SHIFT MENTIONED...AS THE SNOW TRANSITIONS TO
RAIN...THE POTENTIAL EXISTS FOR THE PRECIPITATION TO FREEZE ON BELOW
FREEZING/UNTREATED SURFACES CAUSING SLIPPERY CONDITIONS. THE FAR
WESTERN PORTION OF THE U.P. WILL LIKELY STAY COOL ENOUGH TO REMAIN
ALL SNOW THROUGH THIS EVENT...KEEPING THE POTENTIAL FOR AT LEAST
ADVISORY SNOW OVER THE FAR WESTERN COUNTIES FROM IWD TO NEAR COPPER
HARBOR. AT THIS POINT...WITH CONTINUED MODEL DISAGREEMENT...HAVE
DECIDED AGAINST A HEADLINE. BETWEEN 12Z/04 AND 00Z/05 THE LOW SHIFTS
TO NORTHERN LAKE SUPERIOR ALLOWING THE PRECIPITATION TO TAPER OFF
ACROSS MOST OF THE U.P. AS THE DRY SLOT AND COLD FRONT PASS THROUGH
THE AREA. THE BETTER FORCING AND MOISTURE AT THAT TIME WILL SHIFT
INTO ONTARIO. ANOTHER ISSUE THAT WILL COME ALONG WITH THIS SYSTEM
WILL BE THE POSSIBILITY OF EASTERLY GALE FORCE WINDS ON LAKE
SUPERIOR AS THE LOW INTENSIFIES AND SHIFTS INTO THE U.P. THE BEST
TIME FRAME FOR THIS TO OCCUR WOULD BE 00Z/04 THROUGH 12Z/04. 850MB
WINDS ARE PROGGED TO BE AROUND 30 KNOTS. WHILE TEMPERATURES ARE NOT
TERRIBLY COLD AT 850MB WITH TEMPS RUNNING AROUND 0C TO
-2C...HOWEVER...THIS MAY BE ENOUGH TO ALLOW THE STRONGER WINDS TO
MIX TO THE SURFACE OF THE LAKE AS THE LAKE SURFACE TEMPS ARE RUNNING
AROUND 4C TO 5C. AGAIN THIS IS LARGELY DEPENDENT UPON THE SYSTEM
STRENGTH AND TIMING...WITH BELOW AVERAGE CONFIDENCE.
THURSDAY THROUGH SUNDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME...HOWEVER
THE GFS IS STILL MORE PROGRESSIVE AND SLIGHT FARTHER NORTH THAN THE
EC. THE GFS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY
12Z THURSDAY...WHILE THE EC PLACES THE SURFACE LOW JUST SOUTH OF
JAMES BAY. EITHER WAY...THIS PLACES THE UPPER PENINSULA IN A
WESTERLY TO WEST NORTHWESTERLY FLOW. 850MB TEMPERATURES DURING THIS
TIME ARE EXPECTED TO DROP TO -11C TO -15C WITH LAKE SURFACE
TEMPERATURES AROUND 4C TO 5C. THIS WILL CREATE FAVORABLE CONDITIONS
FOR LAKE EFFECT SNOW TO DEVELOP ACROSS THE AREA. THE SURFACE LOW
WILL REMAIN NEARLY STATIONARY THROUGH SATURDAY AS ANOTHER UPPER
LEVEL 500MB TROUGH AXIS SWINGS INTO THE AREA FRIDAY NIGHT. THIS WILL
BRING SOME OF THE COLDEST AIR SO FAR THIS SEASON INTO THE AREA.
850MB TEMPS ARE PROGGED TO DROP TO AROUND -22C DURING THIS TIME
FRAME...AGAIN ALLOWING A CONTINUATION OF LAKE EFFECT SNOWFALL. HAVE
KEPT WITH THE LIKELY POPS ACROSS WESTERLY WIND FAVORED SNOW BELTS OF
THE U.P....HOWEVER...THIS EVENT WILL LIKELY BE A LONG DURATION EVENT
WITH MODERATE SNOWFALL TOTAL EXPECTED BY THE END OF THE EVENT.
AGAIN...IT IS LIKELY THAT LES WILL OCCUR...IT IS JUST UNLIKELY THAT
THE SNOWFALL RATES WILL BE UNUSUALLY HIGH AT THIS POINT AS THE MORE
FAVORABLE SNOW GROWTH ZONE WILL BE VERY SHALLOW AND INVERSION
HEIGHTS EXPECTED TO BE AROUND 5-6KFT...EVEN AFTER ADJUSTING FOR THE
WARMER LAKE SURFACE TEMPERATURES. THE SNOWFALL TOTALS AND EXACT
LOCATION OF THIS LONGER DURATION EVENT WILL CONTINUE TO BE FINE
TUNED AS THE WEEKEND APPROACHES. ANOTHER PERHAPS MORE DANGEROUS
ASPECT OF THIS WINTER WEATHER EVENT WILL BE THE POTENTIAL FOR A
DANGEROUSLY COLD AIRMASS TO BUILD INTO THE REGION THURSDAY NIGHT
THROUGH SATURDAY NIGHT. WITH 850MB TEMPS AROUND THE -22C MARK AS
PREVIOUSLY MENTION...LOW TEMPERATURES WILL LIKELY FALL INTO THE
TEENS BELOW ZERO WITH DAYTIME HIGHS ONLY REACHING INTO THE SINGLE
DIGITS ABOVE ZERO FOR WESTERN PORTIONS OF THE U.P. WINDS WILL ALSO
BE FAIRLY STRONG ALLOWING WIND CHILLS TO DROP AS LOW AS -30F DURING
THE OVERNIGHT HOURS THROUGH THIS TIME FRAME. SUNDAY MAY BEGIN TO
BRING A BIT OF RELIEF...HOWEVER...AS THE SURFACE LOW AND UPPER LEVEL
500MB TROUGH NEAR JAMES BAY FINALLY BEGINS TO SHIFT EASTWARD. THIS
WILL SLOWLY DIMINISH THE CHANCE OF LES AS A BRIEF RIDGE BUILDS. THIS
WILL ALSO ALLOW TEMPERATURES TO MODERATE SLIGHTLY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 639 AM EST MON DEC 2 2013
KIWD...EXPECT PREDOMINANT VFR CONDITIONS MOST OF TDAY WITH DOWNSLOPE
SE WIND. CONDITIONS WL DETERIORATE TO MVFR LATER TODAY AND THEN TO
IFR TNGT AS A BAND OF SN MOVES IN FM THE W.
KCMX...DOWNSLOPE S-SE WINDS TODAY SHOULD ALLOW VFR CONDITIONS TO
PREVAIL THROUGH MUCH OF TDAY. BUT AS THE FLOW BACKS MORE TOWARD AN
UPSLOPE E DIRECTION LATER IN THE AFTN...AN MVFR CIG IS LIKELY TO
DVLP. AS A BAND OF SN MOVES IN FM THE WSW LATER TNGT...CONDITIONS
SHOULD DETERIORATE INTO THE IFR RANGE IN THE PRESENCE OF THE
STRENGTHENING UPSLOPE E WIND.
KSAW...SHALLOW GROUND FOG/VLIFR CONTITIONS SHOULD GIVE WAY TO VFR
CONDITIONS AS THE FOG DSPTS THIS MRNG. BUT AS THE WIND BECOMES SE
AND UPSLOPES OFF LK MI...EXPECT AN MVFR CIG TO DVLP AND PERSIST THE
REST OF THE FCST PERIOD. ONCE A BAND OF SN ARRIVES FM THE W LATER
TNGT...CONDITIONS MAY AT LEAST APRCH IFR WITH THE PERSISTENT UPSLOPE
FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EST MON DEC 2 2013
A LIGHT S WIND TODAY WILL BACK TOWARD THE E AND INCREASE UP TO 30
KTS BY TUE AS THE PRES GRADIENT TIGHTENS OVER THE UPPER GREAT LAKES
BETWEEN DEPARTING HI PRES OVER SE CANADA AND A LO PRES SYSTEM MOVING
E FROM THE PLAINS. DEPENDING ON THE TRACK AND INTENSITY OF THIS
LO...THERE COULD BE SOME MARGINAL GALES ON TUE INTO TUE NIGHT...
ESPECIALLY WHERE THE TERRAIN SURROUNDING THE LAKE ENHANCES THE E
FLOW. ALTHOUGH WINDS WILL DIMINISH A BIT THRU WED AS THE LO AND
FLATTER GRADIENT MOVES OVERHEAD...EXPECT A STRONGER W WIND TO 30 TO
35 KTS TO DEVELOP FOLLOWING THE PASSAGE OF THE LO INTO ONTARIO ON
WED NIGHT/THU. SINCE THIS WIND WILL ADVECT VERY COLD AIR OVER THE
RELATIVELY WARM WATERS...INCREASING INSTABILITY WILL ENHANCE THE
WINDS AND LIKELY REQUIRE GALE WARNINGS THU THRU FRI FOR AT LEAST
PORTIONS OF THE BIG LAKE. INCREASING WAVES AND THE ARRIVAL OF THE
ARCTIC AIRMASS WILL ALSO CAUSE WIDESPREAD FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
506 AM EST MON DEC 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EST MON DEC 2 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A RELATIVELY LGT
ZONAL FLOW OVER THE UPR GRT LKS TO THE N OF THE MAIN POLAR JET OVER
THE SRN CONUS. AT THE SFC...HI PRES IS PRESENT NEAR JAMES BAY...WITH
A WEAK LO PRES TROF ORIENTED WNW TO ESE OVER UPR MI. THIS TROF HAS
BEEN THE FOCUS FOR SOME LGT -SN MIXED AT TIMES WITH -FZDZ DESPITE
RELATIVELY HI CIGS ASSOCIATED WITH A BIT OF DRIER LLVL AIR SHOWN ON
THE LOCAL 00Z RAOBS BLO SUBSIDENCE INVRN BASE JUST ABV H85. H85
TEMPS ARND -9C RELATIVE TO LK SUP TEMPS ARND 4C HAVE ALSO LIMITED
THE SN INTENSITY. GIVEN THE VERY LGT WIND FIELDS...SFC WINDS AS WELL
AS MQT RADAR IMAGERY INDICATE SOME VORTICES HAVE FORMED OVER THE
RELATIVELY WARM LK WATERS...WITH ONE CENTERED JUST E OF KEWEENAW BAY
AND ANOTHER N OF MUNISING. THERE APPEARS TO BE ANOTHER ONE OVER NRN
LK MI...WHERE THE OPEN WATER TEMP OF 7C REPORTED BY THE 45002 BUOY
AT THE NRN END OF THE LK IS ALLOWING A BIT MORE OVERWATER
INSTABILITY. SINCE THE SFC HI NEAR JAMES BAY IS DRIFTING TO THE
E...THE LLVL WINDS HAVE TENDED TO VEER MORE TO THE S-SW PER THE MQT
88D VWP...ESPECIALLY OVER THE W HALF OF THE CWA. THIS WSHFT IS
CAUSING THE RADAR ECHOES TO DRIFT SLOWLY TO THE N. THIS FLOW ALSO
APPEARS TO BE ADVECTING EVEN DRIER LLVL AIR SHOWN ON THE 00Z MPX AND
QUAD CITIES IA RAOBS TO THE N. ALTHOUGH LOTS OF SC LINGER OVER NRN
WI...THERE HAS BEEN PARTIAL CLRG OVER THE CENTRAL PART OF WI. BUT
MORE WAD CLDS ASSOCIATED WITH ISENTROPIC ASCENT BTWN THE DEPARTING
HI AND LOWER PRES IN THE NRN PLAINS AND BEST DEPICTED ON THE
285-295K SFCS /H85-65/ IS SPREADING QUICKLY TO THE E THRU MN AND
INTO WRN WI. THERE HAS EVEN BEEN SOME -SN AS FAR E AS CNTRL MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LINGERING CHCS FOR -SHSN/
-FZDZ TDAY. FOCUS FOR LATER TODAY AND TNGT SHIFTS TO POPS FOR SN
ASSOCIATED WITH THE ISENTROPIC LIFT SPREADING IN FM THE W.
TODAY...WITH THE CONTINUED TREND FOR THE H925 WINDS TO SHIFT TO THE
S THIS MRNG AND CAUSE THE LO PRES TROF TO DRIFT TO THE N...EXPECT
THE BULK OF LINGERING PCPN OVER UPR MI TO MOVE INTO LK SUP. THE BEST
CHC FOR MORE PCPN MAY BE OVER THE SE COUNTIES AS THE VORTEX NOW
PRESENT OVER NRN LK MI DRIFTS INLAND AS SHOWN BY A NUMBER OF THE HI
RES MODELS. THE QPF FM SOME OF THESE MODELS INDICATES THERE COULD BE
A FEW INCHES OF SN IN THIS AREA...BUT PRESENCE OF THE DGZ ABV THE
MOIST LYR/SHARPER LLVL UVV MAX AS WELL AS MARGINAL OVERWATER
INSTABILITY WITH H85 TEMPS PROGGED TO WARM TOWARD -7 TO -8C BY 00Z
SUG THE PCPN WL BE RELATIVELY LGT AND POSSIBLY EVEN MIXED WITH SOME
-FZDZ. ALTHOUGH THE DRIER NEAR SFC AIR BRINGING CLRG TO PORTIONS OF
CENTRAL WI MAY DRIFT A BIT FARTHER TO THE N THIS MRNG...A TREND FOR
THE SFC-H925 WINDS TO BACK TO THE SE THIS AFTN AND UPSLOPE OFF LK MI
WL LIKELY LIMIT ANY CLRG THAT MIGHT BRIEFLY IMPACT THE FAR SCENTRAL.
THE NAM ALSO SHOWS HIER MID LVL RH ON THE 285-295K SFCS PUSHING INTO
THE W HALF OF THE CWA DURING THE AFTN EVEN THOUGH THE ISENTROPIC
ASCENT APPEARS TO WEAKEN WITH TIME. WL RETAIN CHC POPS OVER THE FAR
W LATER IN THE DAY TO REFLECT THE POTENTIAL FOR SOME OF THE LGT -SN
NOW SHOWING UP AT SOME PLACES IN MN TO IMPACT THAT AREA.
TNGT...MOST OF THE NUMERICAL GUIDANCE SPREADS THE WAD PCPN INTO THE
WRN CWA TNGT WITH THE ARRIVAL OF H85-5 QVECTOR CVNGC AS WELL AS SOME
UPR DVGC IN THE LEFT EXIT REGION OF AN UPR JET SHIFTING E AWAY FM AN
UPR TROF THAT IS FCST TO DEEPEN OVER THE W. THE GFS IS STRONGEST
WITH THIS UPR DVGC AND THE ISENTROPIC ASCENT...GENERATING UP TO 0.75
INCH OF WATER EQUIVALENT PCPN AT IWD BY 12Z TUE...WHERE THE MODEL
ALSO SHOWS A CENTER OF STRONGER H85-7 FGEN. THE BULK OF THE OTHER
MODELS APPEAR TO FOCUS THE BETTER ISENTROPIC ASCENT TO THE S AND
SPIT OUT MUCH LESS PCPN...GENERALLY 0.10 TO 0.30 INCH IN THIS AREA.
CONSIDERING THE DRIER NATURE OF THE AIR TO THE S AND NCEP PREFERENCE
FOR A NON-GFS EVOLUTION...THE LOWER QPF SEEMS MORE RSNBL. BUT DID
BUMP POPS UP TO LIKELY IN THIS AREA...WITH CHC POPS DIMINISHING TO A
DRY FCST OVER THE E.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 505 AM EST MON DEC 2 2013
VERY CHALLENGING FORECAST IN STORE FOR THE TUESDAY THROUGH WEDNESDAY
NIGHT TIME FRAME. BEHIND THIS SYSTEM...LAKE EFFECT SNOW AND WELL
BELOW NORMAL TEMPERATURES ARE EXPECTED TO MOVE IN FOR THE LAST HALF
OF THE WORK WEEK INTO THE WEEKEND WITH DANGEROUS WIND CHILLS
EXPECTED TO APPROACH -30F BY FRIDAY NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...MODEL AGREEMENT HAS INCREASED A
BIT FURTHER FOR THROUGH THIS TIME PERIOD...HOWEVER SLIGHT
DIFFERENCES REMAIN. THE GFS/NAM/EC SOLUTIONS 12Z/03 HAVE A SURFACE
LOW POSITIONED OVER THE SOUTHWEST CORNER OF MN...WHILE THE GEM HAS
BECOME THE MAIN OUTLIER...KEEPING THE SURFACE LOW FARTHER SOUTH OVER
SOUTHEASTERN NE. AT THE SAME TIME AN UPPER LEVEL 500MB CLOSED LOW IS
EXPECTED TO SLOWLY EJECT FROM THE NORTHERN ROCKIES TOWARD THE UPPER
MIDWEST. BY 18Z/03 THE GFS/EC HAVE THE SURFACE LOW SHIFTING
NORTHWARD TOWARD FAR WESTERN LAKE SUPERIOR. AS THIS HAPPENS A WARM
FRONT IS EXPECTED TO LIFT NORTHWARD...REACHING THE SOUTHERN HALF OF
UPPER MI BY 18Z TUES. ISENTROPIC UPGLIDE ALONG THIS FRONT ALONG WITH
INCREASED MOISTURE ON THE 295K ISOSURFACE WILL ALLOW PRECIPITATION
TO FORM AND SPREAD ACROSS MUCH OF THE U.P. BY 18Z/03. BY 06Z
WEDNESDAY THE GFS HAS THE SURFACE LOW DIRECTLY OVER THE WESTERN HALF
OF UPPER MI...WHILE THE 00Z RUN OF THE EC KEEPS THE LOW LESS INTENSE
AND FARTHER SOUTH OVER NORTHERN MO. IF THE GFS IS CORRECT
PRECIPITATION WOULD START EARLIER OVER THE U.P...WHILE THE EC WOULD
SLOW THE PRECIP DOWN BY ABOUT 6 HOURS. TRIED TO ACCOUNT FOR THE
DISCREPANCIES BY SLOWING THE ONSET OF LIKELIES BY A FEW HOURS. BOTH
THE GFS AND EC EVENTUALLY HAVE THE LOW CROSSING THE WESTERN HALF OF
THE U.P. WHICH WILL KEEP THE EASTERN HALF OF THE U.P. IN THE WARM
AIR ADVECTING INTO THE REGION ALONG WITH CONTINUED ISENTROPIC
UPGLIDE ACROSS THOSE AREAS...ALLOWING THE PRECIPITATION TO
TRANSITION INTO A RAIN SNOW MIXTURE DURING THAT TIME FRAME. THIS
WOULD HELP KEEP SNOWFALL TOTALS BELOW ADVISORY CRITERIA IN THOSE
AREAS. AS THE PREVIOUS SHIFT MENTIONED...AS THE SNOW TRANSITIONS TO
RAIN...THE POTENTIAL EXISTS FOR THE PRECIPITATION TO FREEZE ON BELOW
FREEZING/UNTREATED SURFACES CAUSING SLIPPERY CONDITIONS. THE FAR
WESTERN PORTION OF THE U.P. WILL LIKELY STAY COOL ENOUGH TO REMAIN
ALL SNOW THROUGH THIS EVENT...KEEPING THE POTENTIAL FOR AT LEAST
ADVISORY SNOW OVER THE FAR WESTERN COUNTIES FROM IWD TO NEAR COPPER
HARBOR. AT THIS POINT...WITH CONTINUED MODEL DISAGREEMENT...HAVE
DECIDED AGAINST A HEADLINE. BETWEEN 12Z/04 AND 00Z/05 THE LOW SHIFTS
TO NORTHERN LAKE SUPERIOR ALLOWING THE PRECIPITATION TO TAPER OFF
ACROSS MOST OF THE U.P. AS THE DRY SLOT AND COLD FRONT PASS THROUGH
THE AREA. THE BETTER FORCING AND MOISTURE AT THAT TIME WILL SHIFT
INTO ONTARIO. ANOTHER ISSUE THAT WILL COME ALONG WITH THIS SYSTEM
WILL BE THE POSSIBILITY OF EASTERLY GALE FORCE WINDS ON LAKE
SUPERIOR AS THE LOW INTENSIFIES AND SHIFTS INTO THE U.P. THE BEST
TIME FRAME FOR THIS TO OCCUR WOULD BE 00Z/04 THROUGH 12Z/04. 850MB
WINDS ARE PROGGED TO BE AROUND 30 KNOTS. WHILE TEMPERATURES ARE NOT
TERRIBLY COLD AT 850MB WITH TEMPS RUNNING AROUND 0C TO
-2C...HOWEVER...THIS MAY BE ENOUGH TO ALLOW THE STRONGER WINDS TO
MIX TO THE SURFACE OF THE LAKE AS THE LAKE SURFACE TEMPS ARE RUNNING
AROUND 4C TO 5C. AGAIN THIS IS LARGELY DEPENDENT UPON THE SYSTEM
STRENGTH AND TIMING...WITH BELOW AVERAGE CONFIDENCE.
THURSDAY THROUGH SUNDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME...HOWEVER
THE GFS IS STILL MORE PROGRESSIVE AND SLIGHT FARTHER NORTH THAN THE
EC. THE GFS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY
12Z THURSDAY...WHILE THE EC PLACES THE SURFACE LOW JUST SOUTH OF
JAMES BAY. EITHER WAY...THIS PLACES THE UPPER PENINSULA IN A
WESTERLY TO WEST NORTHWESTERLY FLOW. 850MB TEMPERATURES DURING THIS
TIME ARE EXPECTED TO DROP TO -11C TO -15C WITH LAKE SURFACE
TEMPERATURES AROUND 4C TO 5C. THIS WILL CREATE FAVORABLE CONDITIONS
FOR LAKE EFFECT SNOW TO DEVELOP ACROSS THE AREA. THE SURFACE LOW
WILL REMAIN NEARLY STATIONARY THROUGH SATURDAY AS ANOTHER UPPER
LEVEL 500MB TROUGH AXIS SWINGS INTO THE AREA FRIDAY NIGHT. THIS WILL
BRING SOME OF THE COLDEST AIR SO FAR THIS SEASON INTO THE AREA.
850MB TEMPS ARE PROGGED TO DROP TO AROUND -22C DURING THIS TIME
FRAME...AGAIN ALLOWING A CONTINUATION OF LAKE EFFECT SNOWFALL. HAVE
KEPT WITH THE LIKELY POPS ACROSS WESTERLY WIND FAVORED SNOW BELTS OF
THE U.P....HOWEVER...THIS EVENT WILL LIKELY BE A LONG DURATION EVENT
WITH MODERATE SNOWFALL TOTAL EXPECTED BY THE END OF THE EVENT.
AGAIN...IT IS LIKELY THAT LES WILL OCCUR...IT IS JUST UNLIKELY THAT
THE SNOWFALL RATES WILL BE UNUSUALLY HIGH AT THIS POINT AS THE MORE
FAVORABLE SNOW GROWTH ZONE WILL BE VERY SHALLOW AND INVERSION
HEIGHTS EXPECTED TO BE AROUND 5-6KFT...EVEN AFTER ADJUSTING FOR THE
WARMER LAKE SURFACE TEMPERATURES. THE SNOWFALL TOTALS AND EXACT
LOCATION OF THIS LONGER DURATION EVENT WILL CONTINUE TO BE FINE
TUNED AS THE WEEKEND APPROACHES. ANOTHER PERHAPS MORE DANGEROUS
ASPECT OF THIS WINTER WEATHER EVENT WILL BE THE POTENTIAL FOR A
DANGEROUSLY COLD AIRMASS TO BUILD INTO THE REGION THURSDAY NIGHT
THROUGH SATURDAY NIGHT. WITH 850MB TEMPS AROUND THE -22C MARK AS
PREVIOUSLY MENTION...LOW TEMPERATURES WILL LIKELY FALL INTO THE
TEENS BELOW ZERO WITH DAYTIME HIGHS ONLY REACHING INTO THE SINGLE
DIGITS ABOVE ZERO FOR WESTERN PORTIONS OF THE U.P. WINDS WILL ALSO
BE FAIRLY STRONG ALLOWING WIND CHILLS TO DROP AS LOW AS -30F DURING
THE OVERNIGHT HOURS THROUGH THIS TIME FRAME. SUNDAY MAY BEGIN TO
BRING A BIT OF RELIEF...HOWEVER...AS THE SURFACE LOW AND UPPER LEVEL
500MB TROUGH NEAR JAMES BAY FINALLY BEGINS TO SHIFT EASTWARD. THIS
WILL SLOWLY DIMINISH THE CHANCE OF LES AS A BRIEF RIDGE BUILDS. THIS
WILL ALSO ALLOW TEMPERATURES TO MODERATE SLIGHTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1222 AM EST MON DEC 2 2013
KIWD...EXPECT MVFR CIGS TO CONTINUE THROUGH MUCH OF MONDAY IN SE
FLOW. LIGHT SNOW MOVING IN BY 22-23Z MON EVENING AHEAD OF
APPROACHING LOW PRES FROM THE PLAINS WILL LOWER CIGS TO 1500 FT AND
MAY REDUCE VSBY TO 3 SM.
KCMX...DOWNSLOPE ESE-SE WINDS SHOULD ALLOW FOR VFR CONDITIONS TO
PREVAIL THROUGH MUCH OF THE PD. ONSET OF SNOW AHEAD OF APPROACHING
PLAINS SYSTEM WILL LEAD TO MVFR CONDITIONS TOWARD 04Z TUE.
KSAW...LIGHT SRLY WINDS WILL MAINTAIN VFR CONDITIONS FOR THE NEXT
FEW HRS...BUT THEN LOOK FOR MVFR CIGS TO DEVELOP TOWARD SUNRISE AS
FLOW BCMS MORE VARIABLE AND THEN EVENTUALLY SE BY LATE MON MORNING.
UPSLOPE SE FLOW INTO MON EVENING WILL MAINTAIN MVFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EST MON DEC 2 2013
A LIGHT S WIND TODAY WILL BACK TOWARD THE E AND INCREASE UP TO 30
KTS BY TUE AS THE PRES GRADIENT TIGHTENS OVER THE UPPER GREAT LAKES
BETWEEN DEPARTING HI PRES OVER SE CANADA AND A LO PRES SYSTEM MOVING
E FROM THE PLAINS. DEPENDING ON THE TRACK AND INTENSITY OF THIS
LO...THERE COULD BE SOME MARGINAL GALES ON TUE INTO TUE NIGHT...
ESPECIALLY WHERE THE TERRAIN SURROUNDING THE LAKE ENHANCES THE E
FLOW. ALTHOUGH WINDS WILL DIMINISH A BIT THRU WED AS THE LO AND
FLATTER GRADIENT MOVES OVERHEAD...EXPECT A STRONGER W WIND TO 30 TO
35 KTS TO DEVELOP FOLLOWING THE PASSAGE OF THE LO INTO ONTARIO ON
WED NIGHT/THU. SINCE THIS WIND WILL ADVECT VERY COLD AIR OVER THE
RELATIVELY WARM WATERS...INCREASING INSTABILITY WILL ENHANCE THE
WINDS AND LIKELY REQUIRE GALE WARNINGS THU THRU FRI FOR AT LEAST
PORTIONS OF THE BIG LAKE. INCREASING WAVES AND THE ARRIVAL OF THE
ARCTIC AIRMASS WILL ALSO CAUSE WIDESPREAD FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
916 PM CST TUE DEC 3 2013
.UPDATE...
MADE SOME MINOR TEMPERATURE ADJUSTMENTS UPWARD SOUTHEAST 1/2 OR SO
TNGT AND ALSO REDUCED PRECIP CHANCES NORTHEAST THIS EVENING.
&&
.DISCUSSION...
COLD AIR IS HAVING MORE SUCCESS DROPPING SOUTH THAN SOUTHEAST AND
COLDEST TONIGHT WILL PROBABLY STAY TO OUR N THROUGH WEST. THUS
BUMPED UP MIN TEMPS A FEW DEGREES FAR E AND SE. ALSO FIRST BATCH
OF RADAR RETURNS HAVE ENDED OVER NERN NEBR AND SHORT TERM MODELS
SUGGEST MEASURABLE MAY NOT RETURN UNTIL LATE TONIGHT/EARLY
WEDNESDAY. THUS REDUCED POPS NERN ZONES THIS EVENING BUT
INCREASED LATER TONIGHT. LATEST RAP SOUNDINGS STILL SUGGEST SOME
FREEZING DRIZZLE POSSIBLE LATE TONIGHT/EARLY WEDNESDAY TOWARD LNK
AND OMAHA...AND AS COLD AIR DEEPENS...IF PRECIP CONTINUES...SOME
SLEET/SNOW PELLETS POSSIBLE AS WELL. JUST LEFT PATCHY FREEZING
DRIZZLE MENTION FOR NOW AS MEASURABLE DID NOT APPEAR TOO LIKELY
YET.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 541 PM CST TUE DEC 3 2013/
AVIATION...
00Z TAFS FOR KOFK...KOMA AND KLNK.
VERY SHALLOW COLD AIR WILL FEED SLOWLY SOUTH TONIGHT SPREADING IFR
CIGS CURRENTLY IN NERN NEBR/NWRN IA SOUTH ACROSS KLNK/KOMA MID-
LATE EVENING. ALTHOUGH MOST OF ANY ACCUMULATING PRECIPITATION WILL
OCCUR FROM AROUND KOFK AND LOCATIONS TO THE NORTH...WHERE BETTER
FORCING EXISTED...A PERIOD OF LIGHT PRECIP COULD FALL AT KOMA AND
KLNK WHEN COLD AIR AND CLOUDS BECOME DEEP ENOUGH LATE TONIGHT INTO
WED MORNING. FORECAST SOUNDINGS WOULD INDICATE IT WOULD BE MOSTLY
FZDZ OR PERHAPS LIGHT SLEET. SOME LIGHT FZDZ OR SLEET COULD ALSO
FALL FOR A PERIOD AT KOFK THIS EVENING.
CHERMOK
PREV DISCUSSION... /ISSUED 335 PM CST TUE DEC 3 2013/
DISCUSSION...
LATEST OBJECTIVE SURFACE ANALYSIS DEPICTS LOW PRESSURE OVER THE
OKLAHOMA PANHANDLE....SPECIFICALLY JUST EAST OF COLORADO SPRINGS
AS OF 21Z. LATEST MODEL GUIDANCE TRANSLATES THIS FEATURE ALONG
THE KANSAS/OKLAHOMA BORDER OVERNIGHT AND THEN TO EASTERN IOWA BY
WEDNESDAY AFTERNOON. THIS RESULTS IN COLD AIR DROPPING ACROSS
THE CENTRAL PLAINS FOR THE NEXT SEVERAL DAYS. AS THIS COLD AIR
DIPS SOUTH...MID LEVEL FORCING CO-LOCATED WITH AVAILABLE MOISTURE
WILL GENERATE ACCUMULATING SNOW OVER PORTIONS OF
KNOX/CEDAR/ANTELOPE/PIERCE COUNTIES OVERNIGHT. BASED ON THE LATEST
INFORMATION...THE BETTER FORCING AND HIGHER ACCUMULATIONS ARE
LIKELY TO VERIFY ACROSS SOUTHEAST SOUTH DAKOTA. GIVEN THE EXPECTED
MOISTURE TRACK DECIDED TO UP SNOW AMOUNTS A BIT FOR NORTHEAST
NEBRASKA...WITH 1-3 INCHES OF SNOW EXPECTED ACROSS KNOX
COUNTY...AND A HALF INCH TO 1 INCH ELSEWHERE ACROSS NORTHEAST
NEBRASKA. AS THE BOUNDARY LAYER TRANSITIONS BELOW FREEZING SOME
ICE PELLETS/SLEET ARE ALSO POSSIBLE AS HAS BEEN ALREADY REPORTED
AT WAYNE. OPTED TO REMOVE ANY MENTION OF FREEZING RAIN AS
PROFILES SUGGEST ITS UNLIKELY TO OCCUR. FURTHER SOUTH LOW LEVEL
MOISTURE PROFILES ARE MEAGER AND SOUTHEAST OF THE PREVIOUSLY
MENTIONED COUNTIES IT APPEARS FREEZING DRIZZLE IS MORE LIKELY
GIVEN THE LACK OF APPRECIABLE FORCING AND ICE IN THE CLOUD. THIS
FREEZING DRIZZLE COULD LINGER THROUGH RUSH HOUR AND POSSIBLY LATER
IN THE MORNING. BY AFTERNOON THE LOW LEVELS SHOULD DRY OUT ENOUGH
TO END ANY DRIZZLE CONCERNS.
BEYOND WEDNESDAY NIGHT QUIET WEATHER LOOKS TO BE THE RULE THOUGH
VERY COLD AIR WILL REMAIN IN PLACE. DAYTIME HIGHS WILL STRUGGLE TO
GET OUT THE TEENS AND OVERNIGHT LOWS WILL FLIRT WITH ZERO EACH
NIGHT. BY FRIDAY GUIDANCE IS HINTING AT A WINTER STORM OVER
KANSAS AND MISSOURI...FOR NOW THIS LOOKS TO STAY SOUTH OF
NEBRASKA AND IOWA.
PEARSON
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
A BROAD UPPER TROUGH WILL KEEP THE REGION COLD THROUGHOUT THE
EXTENDED PERIOD. SOUTHWESTERLY FLOW ALOFT WILL SEND A SERIES OF
LITTLE IMPULSES TO THE AREA AND WILL PROVIDE A SMALL CHANCE FOR
LIGHT SNOW SATURDAY NIGHT INTO SUNDAY MORNING. MOISTURE IS
LIMITED...SO NOT EXPECTING MORE THAN AN INCH OR SO DURING THIS TIME.
BETTER FORCING COMES INTO PLAY SUNDAY INTO SUNDAY NIGHT AS FORCING
FROM A STRONG SHORTWAVE TROUGH MOVES NORTHEAST OUT OF COLORADO. IN
ADDITION...THE LEFT FRONT QUAD OF A 150KT 300 MB JET WILL BE PASSING
OVERHEAD PROVIDING STRONG UPPER DIVERGENCE. WE CURRENTLY HAVE CHANCE
POPS GOING AND THAT MAY NEED TO BE BUMPED UP WITH LATER FORECAST IF
THE FORCING IS STILL LOOKING STRONG. A VERY STRONG COLD PUSH WILL
SINK INTO THE REGION MONDAY NIGHT INTO TUESDAY MORNING WITH PROGGED
850MB TEMPS ANYWHERE FROM -20C TO -25C.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1046 PM MST SUN DEC 1 2013
.AVIATION...
06Z TAF CYCLE
AREAS OF IFR AND LOCALLY LIFR CATEGORY STRATUS CIGS WILL LIKELY
CONTINUE TO BE AN AVIATION HAZARD ACROSS A GOOD PORTION OF NW NM
THROUGH THE NEXT 12 HRS...THAT IS THROUGH 18Z MON. THE VISIBILITY
IN FOG WILL LOWER AGAIN AFTER 10Z TONIGHT TO IFR LEVELS. ELSEWHERE
ONLY HIGH CIRRUS CLOUDS AND LIGHT TO MODERATE BREEZES ARE EXPECTED
WITH VFR CONDITIONS THROUGH THE NEXT 24 HOURS. 40
&&
.PREV DISCUSSION...325 PM MST SUN DEC 1 2013...
MAIN FORECAST CHALLENGE IN THE SHORT-TERM CONTINUES TO BE NAILING
DOWN WHEN THE PERSISTENT LOW CLOUD DECK OVER NW AND WEST CENTRAL NM
WILL SCOUR OUT OF THE AREA. THE VAST MAJORITY OF MODEL GUIDANCE DID
NOT SHOW THESE CLOUDS CONTINUING TO PLAGUE THE AREA TODAY BUT ALAS
THEY ARE STILL HOLDING STRONG. THE RUC13 WAS THE BEST TO HOLD ONTO
SATURATION IN THE NEAR SURFACE LAYER AND INDICATIONS ARE THAT IT
WILL CONTINUE TONIGHT AND EARLY MONDAY. WINDS ALOFT AND EVEN AT THE
SURFACE ARE INCREASING HOWEVER IT IS POSSIBLE THE THICK/PERSISTENT
LOW CLOUD DECK IS FEEDING BACK TO STRENGTHEN LOW LEVEL INVERSIONS
AND KEEP A VERY SHALLOW BOUNDARY LAYER DECOUPLED. OTHER INTERESTING
ITEM WILL BE WHETHER LOW CLOUDS CAN SEEP OVER THE WEST MESA AND END
UP IN THE MIDDLE RIO GRANDE VALLEY TONIGHT AS INCREASING NW FLOW
ADVECTS THE LAYER SE. BEST SHOT WILL BE WEST SIDE SO HAVE INCREASED
TO MOSTLY CLOUDY THERE OVERNIGHT.
CONSIDERABLE DIFFERENCES REMAIN WITH MODEL GUIDANCE ON THE DETAILS
OF THE NEXT SIGNIFICANT STORM SYSTEM BEYOND WEDNESDAY. FIRST WE
HAVE TO DEAL WITH SOME WIND. NW FLOW OVER THE REGION TODAY WILL
BACK TO WEST AND INCREASE TUESDAY. 700-500MB LAYER WINDS BTWN 50
AND 60KTS WILL COMBINE WITH A SURFACE LOW OVER THE PLAINS TO CREATE
STRONG WEST WINDS ALONG AND EAST OF THE CENTRAL MT CHAIN. IT IS
STILL A LITTLE EARLY BUT BETS ARE GOOD ON A HIGH WIND WATCH FROM
THE FOLLOWING SHIFT FOR TUESDAY. HEIGHT FALLS AND COLD ADVECTION
WILL BEGIN TUESDAY NIGHT ACROSS THE WEST AS THE JET AXIS DEPARTS
TO THE EAST. MEANWHILE...THE PLAINS PORTION OF AN ARCTIC AIRMASS
WILL BE SHIFTING SOUTH TOWARD THE NE PLAINS.
MODELS THEN STRUGGLE CONSIDERABLY DEALING WITH THE APPROACH OF A
SHEARING UPPER TROUGH AXIS OVER THE WESTERN CONUS WEDNESDAY AND
THURSDAY AND THE DEGREE OF MOISTURE ASSOCIATED WITH IT. A REALLY
GOOD CERTAINTY IS THAT IT IS GOING TO GET VERY COLD. AT THIS TIME
THE SUITE OF ENSEMBLE AND WPC GUIDANCE SHOWS THE PLAINS PORTION OF
THE ARCTIC AIRMASS SETTLING ONTO THE EAST SLOPES OF THE CENTRAL MT
CHAIN WHILE THE SECOND PORTION SHIFTS SOUTH THRU THE INTERMOUNTAIN
WEST. 700MB TEMPS BTWN -10 AND -14C WITH THIS AIRMASS ARE 1 TO 2
STANDARD DEVIATIONS BELOW CLIMO AND RESULTS IN HIGH TEMPS 15 TO 25
F BELOW NORMAL ALL AREAS. QPF AND SNOW IMPACTS WILL BE THE GREATEST
CHALLENGE WITH THIS SYSTEM. MODELS AGREE A BAND OF SNOW WILL SHIFT
SE OVER WESTERN NM WEDNESDAY THEN DISSIPATES WEDNESDAY NIGHT...WHILE
LOW CLOUDS AND LIGHT SNOW OR FLURRIES IMPACT THE EAST. THE GFS IS
THEN THE MOST BULLISH BREAKING OUT A LARGE AREA OF LIGHT/MODERATE
SNOW ALONG AND EAST OF THE CONT DVD THURSDAY THEN TAPERS OFF INTO
THE EAST FRIDAY. AT THIS TIME IMPACTS TO TRAVEL MAY BE HIGH WITH
EVEN LIGHT AMOUNTS OF PRECIP DUE TO THE SEVERITY OF THE COLD AND
BLOWING SNOW.
BELIEVE OR NOT MODELS ARE ADVERTISING AN EVEN COLDER SECOND ARCTIC
AIRMASS TO SHIFT SOUTH OVER THE WESTERN CONUS MONDAY AND TUESDAY OF
NEXT WEEK. 700MB TEMPS OVER NORTHERN NM ARE ADVERTISED BY THE ECMWF
TO FALL TO -24C WHICH IS EXCEPTIONALLY COLD. ANOTHER ROUND OF SNOW
IS ALSO ADVERTISED. GUYER
.FIRE WEATHER...
MAIN FIRE WEATHER ISSUES NEXT FEW DAYS WILL BE THE STRONG INVERSIONS
IN PLACE ACROSS ROUGHLY THE NW QUARTER TO THIRD OF THE STATE...
EMPHASIZING THE NW AND WEST CENTRAL VALLEYS TO THE WEST OF THE
CONTINENTAL DIVIDE. THIS WILL CONTINUE QUITE STRONG THROUGH TONIGHT
AND MON MORN...IMPROVING SOME MON AFTN AND RETURNING MORE WEAKLY MON
NIGHT INTO TUE MORN. AS A RESULT VENTILATION RATES TO REMAIN MAINLY
POOR IN THIS AREA THROUGH MON NIGHT. ACCOMPANYING THIS WILL BE VERY
LOW CLOUD DECK AND FREEZING FOG TONIGHT AND WELL INTO MON MORN.
OTHER SIGNIFICANT FIRE WX CONCERN WILL BE RISK OF MARGINALLY
CRITICAL FIRE WEATHER CONDITIONS FOR PERHAPS 2 OR 3 HOURS TUE AFTN
IN MAINLY SOUTHERN PORTION OF ZONE 108 IN EAST CENTRAL NM. MAIN
LIMITING ISSUE WILL BE THE MINIMUM RH.
OUTSIDE OF THE ABOVE MENTIONED AREAS...OVERNIGHT HUMIDITY RECOVERY
WILL STILL BE VERY GOOD TO EXCELLENT IN THE ESTANCIA AND UPPER RIO
GRANDE VALLEYS. HOWEVER...RECOVERIES WILL NOT BE AS HIGH IN THE
EASTERN PLAINS...MAINLY 45 TO 55 PERCENT. SCATTERED LOCALES ALONG
THE CENTRAL MOUNTAIN CHAIN AND CENTRAL HIGHLANDS WILL EXPERIENCE
BREEZY TO OCCASIONALLY WINDY CONDITIONS THROUGHOUT THE NIGHT AND
INTO MON. STILL...POOR VENTILATION/DISPERSION IS EXPECTED WEST OF
CENTRAL MTN CHAIN THROUGH MON NIGHT WITH TEMPERATURES RISING A
COUPLE TO SEVERAL DEGREES OVER TODAY. EAST OF CENTRAL MTN CHAIN
EXPECT FAIR TO LOCALLY VERY GOOD VENT RATES MON AFTN.
FLOW ALOFT BECOMES MORE WESTERLY MON NIGHT AND WEST SOUTHWESTERLY
BY TUE NIGHT AS LONGWAVE TROUGH ESTABLISHES TO THE WEST OF NM. AS
WINDS DRAMATICALLY INCREASE ALOFT THE 10000 FT LEVEL WINDS ARE
LIKELY TO REACH 45 TO 65 KT...PERHAPS EVEN A BIT HIGHER...ON MUCH OF
THE HIGHER TERRAIN. STRONG BUT RATHER SHALLOW BACK DOOR FRONT LIKELY
TO ENTER FAR NE NM LATE TUE OR EARLY WED WITH THE USUAL TIMING
DIFFERENCES BETWEEN THE MODELS. STRONG WINDS WILL REMAIN A CONCERN
FOR HIGH TERRAIN AREAS TUE. AHEAD OF THE FRONT THE EASTERN PLAINS
WOULD GET SOME DOWNSLOPING WARMING EFFECTS...AS TEMPS RUN 8 TO 15
DEGREES ABOVE AVERAGE WITH HUMIDITY OF 15 TO 20 PERCENT TUE AFTN.
BREEZY TO WINDY CONDITIONS WILL LIKELY PERSIST INTO WED...ESPECIALLY
THE HIGH TERRAIN ZONES...WHILE MUCH COLDER AIR SPILLS INTO THE STATE
FROM THE NE AND NW. SOME LIGHT TO LOCALLY MODERATE PRECIPITATION
WILL ALSO BE POSSIBLE ACROSS FCST AREA WED...SPREADING FARTHER EAST
THU AND FRI. PREFERRED AREAS WILL BE NW TWO THIRDS OF THE STATE. BY
THU THE ENTIRE FORECAST AREA TEMPS LIKELY TO FALL TO BETWEEN 10 AND
30 DEGREES BELOW AVERAGE. LITTLE IF ANY MODERATION FROM THE WELL
BELOW NORMAL TEMPS FRI. VENTILATION WILL SEE A MAJOR BOOST TUE AND
WED...BUT THEN STEADILY LOWER THU INTO FRI. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
40
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1238 AM EST MON DEC 2 2013
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SWING INTO THE GREAT
LAKES REGION TONIGHT AND SLOWLY LIFT INTO QUEBEC DURING THE DAY
MONDAY. HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND
REMAIN OVER THE AREA INTO WEDNESDAY BEFORE ANOTHER LOW AFFECTS
THE REGION MIDWEEK. HIGH PRESSURE RETURNS BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1228 AM EST MONDAY...NO SIGNIFICANT CHANGES WITH THIS
UPDATE. PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ISSUE A FREEZING FOG ADVISORY UNTIL 8 AM FOR THE
CHAMPLAIN VALLEY EASTWARD ACROSS THE REST OF VERMONT. WE`VE
RECEIVED SEVERAL REPORTS OF LIGHT GLAZING THIS EVENING IN THE
AREAS OF FREEZING FOG AND MIST THAT HAVE DEVELOPED ACROSS THE
NORTH COUNTRY. IT APPEARS THAT LIGHT NORTHERLY DRAINAGE FLOW
(EVIDENT IN LOWER RAP MODEL 1000-950MB THICKNESS FIELDS OVER THE
CHAMPLAIN VALLEY) IS HELPING TO MAINTAIN A PERSISTENT AREA OF
FREEZING FOG HERE IN THE CHAMPLAIN VALLEY. THE MAIN IMPACT FROM
FREEZING FOG AND MIST WILL BE FROM ICING...THOUGH VISIBILITIES AS
LOW AS AN EIGHTH OF A MILE ARE POSSIBLE IN AREAS OF FREEZING FOG.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 911 PM EST FOLLOWS...
EARLIER AREAS OF LIGHT SNOW HAVE GENERALLY COME TO AN END EXCEPT
FOR NORTHERN VERMONT AND INTO THE NORTHERN SAINT LAWRENCE VALLEY.
AREAS OF LIGHT SNOW LOOK TO LINGER THROUGH LATE EVENING/AROUND
MIDNIGHT IN THE NORTHEAST KINGDOM...AND CONTINUE PERIODICALLY
ACROSS THE NORTHERN SAINT LAWRENCE VALLEY AND `DACKS THROUGH
OVERNIGHT. HOWEVER...EXPECTING AREAS OF FREEZING DRIZZLE AND
PATCHY FREEZING FOG ACROSS A GOOD PORTION OF THE NORTH COUNTRY
THIS EVENING. POTENTIAL FOR FOG IS SHOWN NICELY ON BUFKIT
SOUNDINGS SHOWING A SATURATED NEAR-SFC LAYER...AND VERY LIGHT BL
FLOW IS ALSO ALLOWING FOR AREAS OF FREEZING MIST/FOG TO DEVELOP
(WITH VISIBILITIES RECENTLY AS LOW AS 1/4SM AT BTV AIRPORT). IN
ADDITION TO THE FOG...WV IMAGERY SHOWS DRY LAYER NOW ACROSS LAKE
ERIE MOVING EASTWARD. THE DRY LAYER ALOFT MAY PRODUCE PATCHY
FREEZING DRIZZLE THROUGH OVERNIGHT. A LIGHT WINTRY MESS TONIGHT
WITH OCCASIONAL PERIODS OF LIGHT SNOW...FREEZING FOG/MIST AND
AREAS OF FREEZING DRIZZLE. THESE CONDITIONS WILL LIKELY LEAD TO
SLIPPERY AREAS ON SIDEWALKS AND UNTREATED ROADWAYS AS WELL AS
SOME LIGHT GLAZING/RIMING ON TREES AND OTHER SURFACES OVERNIGHT.
SEE OUR SPECIAL WEATHER STATEMENT FOR MORE ON POTENTIALLY SLICK
ROADWAYS.
NO CHANGES TO CURRENT TEMPERATURES WITH READINGS GENERALLY
STAYING NEAR CURRENT VALUES THIS EVENING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 315 PM EST SUNDAY...GOING INTO MONDAY...MDLS BRING
SECONDARY TROUGH INTO GREAT LKS REGION...ALLOWING FOR MORE
DIGGING/ AMPLIFICATION OF THE REMNANTS OF CURRENT TROUGH. THE
RESULT FOR THE CWA WILL BE PERSISTENT SW FLOW OVER THE NORTH
COUNTRY. PART OF THIS FLOW WILL OCCUR OVER LK ONTARIO...KEEPING
CHANCE FOR LIGHT PRECIP OVER N NY THRU THE DAY...TAPERING TO JUST
CLDY SKIES OVER EASTERN AND SOUTHERN VT. POSSIBLE FOR A COUPLE
TENTHS EXTRA -SW ACCUM THRU THE DAY...BUT WITH TEMPS ABV NORMAL
ON DECENT WAA...NOT GOING TO LAST. TROUGH LIFTS INTO SOUTHERN
QUEBEC MON NGT...TAPERING OFF SL CHANCE WINTRY PRECIP TO NE
KINGDOM BY TUESDAY MORNING..THEN SFC RIDGE BUILDS OVER AREA FOR
ANOTHER DECENT DAY WITH TEMPS ABV NORMAL. HIGHS IN THE MID/UPPER
30S BOTH DAYS...WITH OVERNGT LOWS ABV NORMAL BY SEVERAL DEGREES
IN THE 20S. WARMEST IN CVLY...COLDEST DACKS/NE VT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 413 PM EST SUNDAY...ECMWF AND GFS MODELS IN GOOD AGREEMENT
ON WEDNESDAY WITH SHOWING A RIDGE OF HIGH PRESSURE OVER THE
REGION. HOWEVER...MODELS SHOWING SOME TIMING DIFFERENCES
WEDNESDAY NIGHT WITH THE ARRIVAL OF PRECIPITATION AHEAD OF A
FRONTAL SYSTEM. HAVE OPTED TO GO WITH THE SLOWER TIMING OF THE
ECMWF AND BRING IN PRECIPITATION AFTER MIDNIGHT WEDNESDAY NIGHT.
MODELS IN AGREEMENT WITH HAVING PRECIPITATION OVER THE REGION ON
THURSDAY. HOWEVER...ECMWF MODEL KEEPS PRECIPITATION OVER THE
REGION THURSDAY NIGHT AS ECMWF SHOWING FRONTAL SYSTEM STALLING
JUST SOUTH OF THE REGION AS IT WILL BE PARALLEL TO THE UPPER
FLOW...AS WEAK WAVES OF LOW PRESSURE MOVE NORTHEAST ALONG THE
FRONT. ECMWF SHOWING PLENTY OF MOISTURE WILL STREAM NORTHEAST
FROM THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS INTO THE REGION.
HAVE LEANED TOWARD THE IDEA OF THE ECMWF IN STALLING THE FRONTAL
SYSTEM JUST SOUTH OF THE REGION WITH PRECIPITATION ACROSS THE
REGION FROM THURSDAY NIGHT THROUGH SATURDAY. MUCH COLDER AIR WILL
WORK INTO THE REGION SATURDAY AND SUNDAY. ALSO...A RIDGE OF HIGH
PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT AND SUNDAY
WITH FAIR AND DRY WEATHER EXPECTED.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THROUGH 06Z TUESDAY...AMBIENT LOW LEVEL MOISTURE AND LIGHT LOW
LEVEL FLOW WILL KEEP BKN/OVC MVFR/IFR CIGS ACROSS MUCH OF THE AREA
OVER THE NEXT 24 HOURS. SOME POCKETS OF VFR HERE AND THERE...BUT
THIS WILL BE THE EXCEPTION RATHER THAN THE RULE. PATCHY LIGHT
-FZDZ AND/OR -SN ALSO POSSIBLE...MAINLY AT KMSS THROUGH 12Z...THEN
POSSIBLE AT OTHER TERMINALS AFTER 18-21Z. AGAIN...WINDS LIGHT AND
GENERALLY 5 KTS OR LESS THROUGH THE FORECAST PERIOD.
OUTLOOK 06Z TUESDAY THROUGH FRIDAY...
06Z TUESDAY THROUGH 06Z THURSDAY...MAINLY VFR...WITH SOME LOCAL
POCKETS OF MVFR.
06Z THURSDAY THROUGH 00Z SATURDAY...AREAS OF MVFR/IFR IN RAIN AND SNOW.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FREEZING FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR
VTZ001>012-016>019.
NY...FREEZING FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR NYZ028-
035.
&&
$$
SYNOPSIS...JN
NEAR TERM...LOCONTO
SHORT TERM...JN
LONG TERM...NEILES
AVIATION...JMG/BANACOS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1230 AM EST MON DEC 2 2013
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SWING INTO THE GREAT
LAKES REGION TONIGHT AND SLOWLY LIFT INTO QUEBEC DURING THE DAY
MONDAY. HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND
REMAIN OVER THE AREA INTO WEDNESDAY BEFORE ANOTHER LOW AFFECTS
THE REGION MIDWEEK. HIGH PRESSURE RETURNS BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1228 AM EST MONDAY...NO SIGNIFICANT CHANGES WITH THIS
UPDATE. PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ISSUE A FREEZING FOG ADVISORY UNTIL 8 AM FOR THE
CHAMPLAIN VALLEY EASTWARD ACROSS THE REST OF VERMONT. WE`VE
RECEIVED SEVERAL REPORTS OF LIGHT GLAZING THIS EVENING IN THE
AREAS OF FREEZING FOG AND MIST THAT HAVE DEVELOPED ACROSS THE
NORTH COUNTRY. IT APPEARS THAT LIGHT NORTHERLY DRAINAGE FLOW
(EVIDENT IN LOWER RAP MODEL 1000-950MB THICKNESS FIELDS OVER THE
CHAMPLAIN VALLEY) IS HELPING TO MAINTAIN A PERSISTENT AREA OF
FREEZING FOG HERE IN THE CHAMPLAIN VALLEY. THE MAIN IMPACT FROM
FREEZING FOG AND MIST WILL BE FROM ICING...THOUGH VISIBILITIES AS
LOW AS AN EIGHTH OF A MILE ARE POSSIBLE IN AREAS OF FREEZING FOG.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 911 PM EST FOLLOWS...
EARLIER AREAS OF LIGHT SNOW HAVE GENERALLY COME TO AN END EXCEPT
FOR NORTHERN VERMONT AND INTO THE NORTHERN SAINT LAWRENCE VALLEY.
AREAS OF LIGHT SNOW LOOK TO LINGER THROUGH LATE EVENING/AROUND
MIDNIGHT IN THE NORTHEAST KINGDOM...AND CONTINUE PERIODICALLY
ACROSS THE NORTHERN SAINT LAWRENCE VALLEY AND `DACKS THROUGH
OVERNIGHT. HOWEVER...EXPECTING AREAS OF FREEZING DRIZZLE AND
PATCHY FREEZING FOG ACROSS A GOOD PORTION OF THE NORTH COUNTRY
THIS EVENING. POTENTIAL FOR FOG IS SHOWN NICELY ON BUFKIT
SOUNDINGS SHOWING A SATURATED NEAR-SFC LAYER...AND VERY LIGHT BL
FLOW IS ALSO ALLOWING FOR AREAS OF FREEZING MIST/FOG TO DEVELOP
(WITH VISIBILITIES RECENTLY AS LOW AS 1/4SM AT BTV AIRPORT). IN
ADDITION TO THE FOG...WV IMAGERY SHOWS DRY LAYER NOW ACROSS LAKE
ERIE MOVING EASTWARD. THE DRY LAYER ALOFT MAY PRODUCE PATCHY
FREEZING DRIZZLE THROUGH OVERNIGHT. A LIGHT WINTRY MESS TONIGHT
WITH OCCASIONAL PERIODS OF LIGHT SNOW...FREEZING FOG/MIST AND
AREAS OF FREEZING DRIZZLE. THESE CONDITIONS WILL LIKELY LEAD TO
SLIPPERY AREAS ON SIDEWALKS AND UNTREATED ROADWAYS AS WELL AS
SOME LIGHT GLAZING/RIMING ON TREES AND OTHER SURFACES OVERNIGHT.
SEE OUR SPECIAL WEATHER STATEMENT FOR MORE ON POTENTIALLY SLICK
ROADWAYS.
NO CHANGES TO CURRENT TEMPERATURES WITH READINGS GENERALLY
STAYING NEAR CURRENT VALUES THIS EVENING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 315 PM EST SUNDAY...GOING INTO MONDAY...MDLS BRING
SECONDARY TROUGH INTO GREAT LKS REGION...ALLOWING FOR MORE
DIGGING/ AMPLIFICATION OF THE REMNANTS OF CURRENT TROUGH. THE
RESULT FOR THE CWA WILL BE PERSISTENT SW FLOW OVER THE NORTH
COUNTRY. PART OF THIS FLOW WILL OCCUR OVER LK ONTARIO...KEEPING
CHANCE FOR LIGHT PRECIP OVER N NY THRU THE DAY...TAPERING TO JUST
CLDY SKIES OVER EASTERN AND SOUTHERN VT. POSSIBLE FOR A COUPLE
TENTHS EXTRA -SW ACCUM THRU THE DAY...BUT WITH TEMPS ABV NORMAL
ON DECENT WAA...NOT GOING TO LAST. TROUGH LIFTS INTO SOUTHERN
QUEBEC MON NGT...TAPERING OFF SL CHANCE WINTRY PRECIP TO NE
KINGDOM BY TUESDAY MORNING..THEN SFC RIDGE BUILDS OVER AREA FOR
ANOTHER DECENT DAY WITH TEMPS ABV NORMAL. HIGHS IN THE MID/UPPER
30S BOTH DAYS...WITH OVERNGT LOWS ABV NORMAL BY SEVERAL DEGREES
IN THE 20S. WARMEST IN CVLY...COLDEST DACKS/NE VT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 413 PM EST SUNDAY...ECMWF AND GFS MODELS IN GOOD AGREEMENT
ON WEDNESDAY WITH SHOWING A RIDGE OF HIGH PRESSURE OVER THE
REGION. HOWEVER...MODELS SHOWING SOME TIMING DIFFERENCES
WEDNESDAY NIGHT WITH THE ARRIVAL OF PRECIPITATION AHEAD OF A
FRONTAL SYSTEM. HAVE OPTED TO GO WITH THE SLOWER TIMING OF THE
ECMWF AND BRING IN PRECIPITATION AFTER MIDNIGHT WEDNESDAY NIGHT.
MODELS IN AGREEMENT WITH HAVING PRECIPITATION OVER THE REGION ON
THURSDAY. HOWEVER...ECMWF MODEL KEEPS PRECIPITATION OVER THE
REGION THURSDAY NIGHT AS ECMWF SHOWING FRONTAL SYSTEM STALLING
JUST SOUTH OF THE REGION AS IT WILL BE PARALLEL TO THE UPPER
FLOW...AS WEAK WAVES OF LOW PRESSURE MOVE NORTHEAST ALONG THE
FRONT. ECMWF SHOWING PLENTY OF MOISTURE WILL STREAM NORTHEAST
FROM THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS INTO THE REGION.
HAVE LEANED TOWARD THE IDEA OF THE ECMWF IN STALLING THE FRONTAL
SYSTEM JUST SOUTH OF THE REGION WITH PRECIPITATION ACROSS THE
REGION FROM THURSDAY NIGHT THROUGH SATURDAY. MUCH COLDER AIR WILL
WORK INTO THE REGION SATURDAY AND SUNDAY. ALSO...A RIDGE OF HIGH
PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT AND SUNDAY
WITH FAIR AND DRY WEATHER EXPECTED.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THROUGH 00Z TUESDAY...AREAS OF LIGHT SNOW...MAINLY FROM THE
CHAMPLAIN VALLEY EWD...WILL CONTINUE THROUGH 03-04Z.
THEREAFTER...IT APPEARS SOME PATCHY FREEZING DRIZZLE WILL OCCUR
FROM SHALLOW LOW STRATUS DECK AT BTV/RUT/MPV WITH TEMPS AT TO
SLIGHTLY BELOW FREEZING. THIS MAY RESULT IN LIGHT ICING
CONDITIONS FOR AIRPORT OPERATIONS OVERNIGHT. ALSO ANTICIPATE IFR
CEILINGS THRU 13-14Z MONDAY AT MSS/MPV AND GENERALLY MVFR
ELSEWHERE. WINDS LIGHT AND VARIABLE OVERNIGHT...AND REMAINING 5
KTS OR LESS DURING THE DAYLIGHT HRS MONDAY. CEILINGS GENERALLY
MVFR (OVC015-025) DURING THE DAYLIGHT HRS MONDAY BUT WITH LESS
POTENTIAL FOR PRECIPITATION.
OUTLOOK 00Z TUESDAY THROUGH FRIDAY...
00Z TUESDAY THROUGH 06Z THURSDAY...MAINLY VFR...WITH SOME LOCAL
POCKETS OF MVFR.
06Z THURSDAY THROUGH 00Z SATURDAY...AREAS OF MVFR/IFR IN RAIN AND SNOW.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FREEZING FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR
VTZ001>012-016>019.
NY...FREEZING FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR NYZ028-
035.
&&
$$
SYNOPSIS...JN
NEAR TERM...LOCONTO
SHORT TERM...JN
LONG TERM...NEILES
AVIATION...BANACOS/WGH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
100 AM EST MON DEC 2 2013
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP SOUTH OF THE AREA TONIGHT AND MOVE
NORTHEAST JUST OFF THE NORTH CAROLINA COAST MONDAY. THE LOW WILL
DEPART TO THE NORTHEAST TUESDAY AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE NORTHWEST THROUGH THE MIDDLE OF THE WEEK. THE HIGH
MOVES OFF THE COAST LATE IN THE WEEK THEN A COLD FRONT PUSHES
THROUGH THE AREA EARLY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1255 AM MONDAY...FORECAST WILL FOLLOW THE GFS MODEL WHICH IS
SUPPORTED BY THE HIGH RESOLUTION RAP MODEL AND DISCOUNT THE
WETTER/FURTHER INLAND PRECIPITATION FORECAST FROM THE NAM MODEL.
DEVELOPING COASTAL LOW PRESSURE WAS PRODUCING AN AREA OF SHOWERS
FROM NEAR THE CRYSTAL COAST TO THE OUTER BANKS SOUTH OF OREGON
INLET. THIS PRECIPITATION IS FORECAST TO PERSIST THROUGH EARLY
AFTERNOON MAINLY ALONG THE COAST SO HAVE RAISED POPS TO LIKELY
SOUTHEAST COAST AND TAPERED THEM TO LESS THAN 20% WELL
INLAND. THE GRADIENT IS VERY WEAK ACROSS THE AREA AND HAS LED TO
CALM WINDS INLAND. A CANOPY OF OVERCAST MID AND HIGH LEVEL CLOUDS
HAS PUSHED INTO SOUTHERN PORTIONS OF EASTERN NC WITH THIS CLOUD
DECK EXPECTED TO REMAIN ACROSS THE FAR SOUTH. WITH MOSTLY CLEAR
SKIES, GOOD RADIATIONAL COOLING IS OCCURRING ACROSS MUCH OF INLAND
EASTERN NC LATE TONIGHT AND THIS WILL GIVE RISE TO AREAS OF DENSE
FOG TONIGHT AND LOW TEMPERATURES FALLING INTO THE 30S. HAVE
ADJUSTED TEMPERATURES DOWNWARD INLAND AND ADDED MENTION OF FOG.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM TUESDAY/...
MOST PRECIP ASSOCD WITH THE AFOREMENTIONED SHORT WAVE AND COASTAL
SFC LOW SHUD FALL DURING THE MORNING HOURS THEN TAPERING OFF TO
MORE SPOTTY LIGHT PRECIP DURING THE AFTERNOON. AGAIN SIGNIFICANT
PRECIP MAY BE LIMITED TO MORE COASTAL AREAS WITH LIGHTER AND MORE
WIDESPREAD RAIN FARTHER INLAND. SKIES WILL REMAIN CLOUDY FOR MUCH
OF THE DAY IN THE INCREASING MOIST LOW LEVEL ONSHORE FLOW. EXPECT
TEMPS WILL REACH INTO THE LOW 60S ALONG THE COAST BUT ONLY MID 50S
OVER DEEP INLAND LOCATIONS.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
AS OF 330 PM SUN...LINGERING PRECIP POSSIBLE MON EVE BUT THE LOW
EAST OF CAPE HATTERAS WILL BE QUICKLY LIFTING NE BRINGING CLEARING
SKIES ACROSS ERN NC AS SFC HIGH PRES AND SHORTWAVE RIDGING BUILDS
ACROSS THE AREA. N/NW FLOW WILL BRING SLIGHTLY BELOW NORMAL TEMPS
WITH LOWS IN THE 30S INLAND TO 40S COAST MON NIGHT WITH HIGHS IN
THE 50S TUE.
A LONGWAVE NRN STREAM UPPER TROUGH DIGS ACROSS THE WRN CONUS
THROUGH THE LATTER HALF OF THE WEEK WHILE SW/NE ORIENTED UPPER
TROUGH AMPLIFIES ACROSS THE SRN GOM AND OFF THE SOUTHEAST COAST
BRINGING SW FLOW ALOFT ACROSS THE ERN CONUS. ABUNDANT PACIFIC
MOISTURE WILL BE TRANSPORTED ACROSS THE SOUTHERN PLAINS IN THE MID
ATLANTIC WHILE A SLOW MOVING COLD FRONT PUSHES ACROSS THE MID WEST
AND MID ATLANTIC STATES. DEEPEST MOISTURE AND BEST UPPER LEVEL
DYNAMICS WILL REMAIN NORTH AND WEST OF THE REGION AND EXPECT
MAINLY DRY CONDITIONS BUT WILL SEE INCREASED CLOUD COVER ACROSS
ERN NC. A FEW MODELS ARE DEPICTING LIGHT QPF TUE NIGHT INTO WED
AS AN AREA OF WEAK AND SHALLOW ISENTROPIC LIFT MOVES ACROSS THE
AREA BUT THINK THEY AREA OVERDONE AND WILL CONTINUE WITH MINIMAL
POPS. THE REGION WILL SEE A WARMING TREND AS THE SFC HIGH SLIDES
OFFSHORE WED WITH INCREASING SWLY FLOW THROUGH THE END OF THE
WEEK. HIGH EXPECTED IN THE 60S WED...LOW 70S THU AND MID 70S ON
FRIDAY WITH MILD OVERNIGHT LOWS.
THE COLD FRONT WILL APPROACH THE REGION FRI NIGHT AND...AT THE
PRESENT TIME...MODELS ARE IN FAIR AGREEMENT WITH THE COLD FRONT
PUSHING SE ACROSS THE REGION FROM ABOUT 12Z-20Z SAT. IMPROVING
UPPER LEVEL DYNAMICS AS THE RIGHT ENTRANCE REGION OF THE UPPER JET
MOVES CLOSER TO THE REGION AND FRONTAL FORCING WILL BRING
INCREASED POPS. A NON-DIURNAL TEMP TREND IS EXPECTED FRI NIGHT AND
SAT SWLY BRINGING MILD TEMPS FRI NIGHT AND TEMPS PEAKING SAT
MORNING...THEN FALLING BEHIND THE FRONT. RAIN CHANCES AND COOL
TEMPS CONTINUE INTO SUN AS ISENTROPIC LIFT CONTINUES IN MOIST
SW FLOW ALOFT OVER SFC HIGH PRES RIDGING IN FROM THE NORTH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH MONDAY NIGHT/...
AS OF 1255 AM MONDAY...HIGH CONFIDENCE IN IFR/LIFR CONDITIONS
OCCURRING AT THE TAF SITES OVERNIGHT IN RADIATIONAL FOG.
PRECIPITATION IS EXPECTED TO OCCUR EAST OF THE TAF SITES WITH A
DEVELOPING COASTAL LOW. WEAK PRESSURE GRADIENT ACROSS EASTERN NC
WILL LEAD TO LIGHT WINDS AND THIS SUGGESTS THAT FOG WILL BE SLOW
TO BURN OFF MONDAY MORNING. ONCE FOG DISSIPATES LATE MONDAY
MORNING EXPECTING VFR CONDITIONS THROUGH MONDAY EVENING THEN COULD
SEE THE REDEVELOPMENT OF RADIATIONAL FOG LATE MONDAY NIGHT.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM SUN...A LOW PRESSURE SYSTEM EAST OF CAPE HATTERAS
WILL LIFT NE MON NIGHT INTO TUE. SUB-VFR CONDITIONS MAY LINGER AT
COASTAL TAF SITES EARLY MON EVENING BUT EXPECT IMPROVING
CONDITIONS AS THE EVENING WEARS ON. PRED VFR CONDITIONS EXPECTED
MID WEEK AS HIGH PRESSURE BUILDS OVER THE AREA. MOISTURE INCREASES
FOR THE LATTER HALF OF THE WEEK AS HIGH PRES SLIDES OFFSHORE AND
SW FLOW INCREASES BUT EXPECT PRED VFR CONDITIONS OUTSIDE OF PATCHY
EARLY MORNING FOG/STRATUS. SHOWER CHANCES GRADUALLY INCREASES
FRIDAY AS A COLD FRONT APPROACHES FROM THE NW.
&&
.MARINE...
SHORT TERM /THROUGH MONDAY/...
AS OF 1255 AM MONDAY...LIGHT VARIABLE WINDS ON THE COASTAL WATERS
AND SOUNDS LATE TONIGHT WILL BECOME MORE N/NE LATER EARLY MONDAY.
WEAK LOW PRESSURE DEVELOPING OFF OF THE COAST MONDAY WILL LEAD TO
STEADILY INCREASING NORTHERLY WINDS FROM 10 TO 15 KT EARLY TO 15-20
KT DURING MON AFTERNOON. SEAS MAINLY 2 TO 4 FT OVERNIGHT AND
MONDAY MAY APPROACH 5 FT OUTER WATERS BY LATE MONDAY AFTN.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM SUN...NW TO N WINDS AROUND 15-20 KT EXPECTED MON
NIGHT IN WAKE OF LOW WITH SEAS 3-5 FT NORTH AND 2-4 FT SOUTH.
WINDS DIMINISH TO BLO 15 KT AND SEAS SUBSIDE TO 2-4 FT THROUGHOUT
TUE AFTERNOON AND TUE NIGHT AS HIGH PRES BUILDS OVER THE AREA.
THE HIGH SLIDES OFFSHORE WED WITH LIGHT WINDS SHIFTING TO SW AND
GRADUALLY INCREASING THROUGH THE END OF THE WEEK AS PRES
GRADIENTS TIGHTEN IN RESPONSE TO A COLD FRONT SLOWLY APPROACHING
FROM THE NW. SCA CONDITIONS POSSIBLY DEVELOP THU NIGHT INTO FRI
WITH WINDS INCREASING TO 15-25 KT AND SEAS BUILD UP TO 4-6 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC/JME
SHORT TERM...BTC
LONG TERM...SK
AVIATION...JME/SK
MARINE...CTC/BTC/JME/SK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
511 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL EXTEND INTO THE AREA TODAY AND THEN GET
PUSHED OFF TO THE NORTHEAST TONIGHT AS A WARM FRONT LIFTS THROUGH
THE REGION. INCREASING SOUTHERLY FLOW AHEAD OF A STRONG COLD
FRONT WILL BRING MUCH WARMER AIR INTO THE OHIO VALLEY THROUGH MID
WEEK. THE COLD FRONT WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT
AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK TROUGH HAS SETTLED ACROSS THE FAR SOUTHERN PART OF THE
FORECAST AREA. EXPECT IT WILL REMAIN THERE THROUGH THE DAY AS WEAK
RIDGING IS WORKING IN FROM THE NORTH. MULTIPLE LEVELS OF CLOUDS
SHOULD KEEP SKIES MOSTLY CLOUDY THROUGH THE DAY. CANNOT
COMPLETELY RULE OUT AN ISOLATED SHOWER DEVELOPING/MOVING INTO THE
NORTHWEST COUNTIES THIS AFTERNOON. TEMPERATURES SHOULD BE SIMILAR
TO YESTERDAYS HIGHS IN MOST LOCATIONS WHICH FOLLOWS CLOSE TO
WARMER GFS MOS NUMBERS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TROUGH NEAR THE OHIO RIVER AT THE BEGINNING OF THE PERIOD WILL
LIFT NORTH TONIGHT AS A WEAK WARM FRONT. LOOKS LIKE A FEW SHOWERS
ARE POSSIBLE NORTH OF THE BOUNDARY. THEREAFTER SOUTHERLY FLOW WILL
INCREASE FOR THE REMAINDER OF THE PERIOD WHICH WILL ADVECT A WARM
AND MOIST AIR MASS INTO THE REGION. ALTHOUGH THERE WILL BE MORE
CLOUDS THAN NOT...EXPECT READINGS TO WARM WELL ABOVE NORMAL.
CONTINUED TO FORECAST TEMPERATURES CLOSER TO WARMER GUIDANCE
NUMBERS. HAVE DISCOUNTED FAST 00Z GFS AND ITS WEDNESDAY FRONTAL
PASSAGE AS IT APPEARS TO HAVE TOO MUCH AMPLITUDE WITH A TROUGH
LIFTING THROUGH THE NORTHERN PLAINS. IT DOES APPEAR THAT SOME
SHOWERS COULD DEVELOP LATE TUESDAY NIGHT INTO WEDNESDAY AS LIFT
INCREASES WITH A LOW LEVEL JET AND A PASSING WEAK MID LEVEL
DISTURBANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THERE CONTINUES TO BE UNCERTAINTY WITH SYSTEMS IN THE LONG TERM.
00Z GFS LOOKS TOO AGGRESSIVE WITH ITS SOLUTION. THE 00Z ECMWF AND
00Z CANADIAN ARE IN FAIRLY GOOD AGREEMENT AND HAVE REASONABLE
SUPPORT FROM THE 00Z/06Z NAM AS FAR OUT AS THAT RUNS. SO HAVE
RELIED ON THE ECMWF/CANADIAN BLEND FOR THE LATTER PART OF THE
WEEK. THIS SUGGESTS THAT A COLD FRONT WILL MOVE THROUGH WEDNESDAY
NIGHT AND THURSDAY. PRECIPITATION WITH THE FRONT WILL NOT BE TOO
SUBSTANTIAL.
THE FRONT STALLS SOUTHEAST OF THE REGION WITH COLDER AIR SETTLING
INTO THE FORECAST AREA. DISTURBANCES IN THE SOUTHERN STREAM WILL
MOVE THROUGH SOUTHWEST FLOW ALOFT. THIS WILL RESULT IN
PRECIPITATION SPREADING WELL NORTH OF THE FRONT BACK ACROSS THE
AREA. THIS COULD COME IN A FEW WAVES FROM LATE THURSDAY INTO
FRIDAY NIGHT. THERE WILL BE A TRANSITION IN PRECIPITATION TYPE
WHICH MAY OSCILLATE ACROSS THE REGION. THERE WILL LIKELY BE
ACCUMULATING SNOW...BUT WITH SO MANY UNCERTAIN VARIABLES AT THIS
POINT IN TIME...LOCATION AND AMOUNT ARE QUITE UNCLEAR.
EXPECT PRECIPITATION TO FINALLY PUSH OFF TO THE SOUTHEAST FRIDAY
NIGHT AS MODIFIED ARCTIC HIGH PRESSURE FINALLY BUILDS IN.
TEMPERATURES WILL BE WELL BELOW NORMAL OVER THE WEEKEND. THERE IS
SOME POTENTIAL FOR ANOTHER WAVE OF WINTRY PRECIPITATION TO SPREAD
BACK IN FROM THE SOUTH ON SUNDAY.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AC DECK CONTINUES TO WORK INTO THE REGION AND OVERRUN A LINGERING
SC DECK. LATEST RUNS OF THE RAP AND NAM ARE BOTH INDICATING THAT
ANY SC THAT LINGER ACROSS THE REGION WILL REMAIN VFR.
MEANWHILE...SOME MVFR FOG WILL BE POSSIBLE ACROSS THE NRN TAFS
THRU SUNRISE.
SC AND AC DECKS WILL LINGER ACROSS THE TAFS ON MONDAY...BUT SHOULD
BE VFR. THEN AS A S/W APPROACHES THE REGION AFT 00Z TUESDAY...THE
STALLED FNT ACROSS THE REGION WILL BEGIN TO LIFT N AS A WARM
FRONT. COULD SEE SOME MVFR CIGS AND A FEW SHRA AS THIS FEATURE
LIFTS N.
OUTLOOK...SOME MVFR CEILINGS POSSIBLE THROUGH TUESDAY MORNING. MVFR
CEILINGS AND VISIBILITIES POSSIBLE AGAIN WEDNESDAY INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1253 AM EST MON DEC 2 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE INTO THE AREA TONIGHT...STALLING AND
DISSIPATING LATE ON MONDAY. INCREASING SOUTHERLY FLOW WILL ALLOW
FOR WARMING TEMPERATURES AND GRADUAL INCREASES FOR PRECIPITATION
CHANCES...BEFORE A STRONGER COLD FRONT MOVES THROUGH THE AREA
LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MID CLOUDS RACING E FROM IL WILL OVERSPREAD THE REGION IN THE NEXT
FEW HOURS. THEY WILL TOP THE LINGERING SC THAT HAS BEEN AFFECTING
PORTIONS OF THE REGION FOR MUCH OF THE DAY.
THE ADDITIONAL CLOUD COVER SHOULD KEEP THE TEMPERATURES IN THE N
FROM FALLING TOO MUCH MORE. EXPECT THE LOWS IN THE NORTH TO DROP
INTO THE LOWER 30S. MEANWHILE ACROSS THE SRN COUNTIES THE
TEMPERATURES SHOULD ONLY DROP INTO THE UPPER 30S..
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
ALTHOUGH NO SIGNIFICANT IMPACTS ARE EXPECTED DURING THE SHORT TERM
OF THE FORECAST...AND POPS ARE EXPECTED TO REMAIN IN THE CHANCE
RANGE OR LOWER...THE SPECIFIC DETAILS FOR PRECIPITATION AND CLOUDS
(IN TERMS OF AMOUNTS AND TIMING) ARE A LITTLE LOWER IN CONFIDENCE
THAN NORMAL.
THE BOUNDARY FORECAST TO MOVE INTO THE FORECAST AREA TONIGHT AND
INTO EARLY MONDAY MORNING WILL LOSE ITS DEFINITION...LEAVING THE
CWA IN A PATTERN OF VERY WEAK S-TO-SE FLOW. FLOW IN THE MID LEVELS
WILL BE QUASI-ZONAL...BUT WITH A SOMEWHAT-BROAD SHORTWAVE MOVING
INTO THE OHIO VALLEY ON MONDAY. THE OVERALL RESPONSE TO THIS
FEATURE IS NOT ESPECIALLY STRONG ON ALL MODELS BUT THE GFS (EVEN
ON BOTH THE 06Z AND 12Z RUNS). ALTHOUGH LOW LEVEL MOISTURE APPEARS
PREVALENT ON MOST MODELS...THE GFS IS BY FAR THE MOST ENHANCED
WITH DEEPER MOISTURE AND QPF RESPONSE. POPS FOR MONDAY AND INTO
MONDAY NIGHT HAVE BEEN SCALED BACK TO SLIGHT CHANCE...PUSHING
NORTH OF THE CWA BEFORE TUESDAY MORNING BEGINS.
AFTER WHAT LOOKS TO BE A DRY PERIOD ON TUESDAY...WARM FRONTAL
PROCESSES WILL BEGIN...AS LOW PRESSURE DEVELOPS OVER THE
MISSISSIPPI VALLEY. THIS WILL INCREASE THE SOUTHERLY FLOW AND
BEGIN A PATTERN OF WARM ADVECTION THAT WILL CONTINUE INTO THE LONG
TERM OF THE FORECAST. INCREASING CONVERGENCE AND MOISTURE
TRANSPORT (ESPECIALLY ALOFT ON TUESDAY NIGHT) WILL RESULT IN
PRECIPITATION CHANCES GRADUALLY INCREASING FROM WEST TO EAST
ACROSS THE CWA...THOUGH MOTION OF SHOWERS WILL BE IN MORE OF A
SSW-TO-NNE DIRECTION. THIS IS ONE PART OF THE FORECAST THAT DOES
COME WITH A BIT OF INCREASING CONFIDENCE. BECAUSE OF
THIS...TEMPERATURE ADJUSTMENTS WERE ALSO REQUIRED FOR BOTH TUESDAY
(SLIGHTLY UPWARD) AND TUESDAY NIGHT (SIGNIFICANTLY UPWARD).
PLENTIFUL CLOUDS AND MOISTURE...COMBINED REASONABLY STRONG FLOW
FOR AN OVERNIGHT PERIOD...SUPPORTS THIS DECISION. THE CURRENT
GRIDS WERE INCREASED BY 5-7 DEGREES...BUT IF SOME OF THE RAW
MODELS ARE TO BE BELIEVED...THIS MAY NOT EVEN BE ENOUGH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN WILL TRANSITION TO A HIGHLY AMPLIFIED REGIME
THROUGH THE EXTENDED PERIOD. THERE CONTINUES TO BE ISSUES WITH
TIMING AND RUN TO RUN CONTINUITY WITH MAJOR SYNOPTIC SYSTEMS TO
AFFECT OUR REGION. LOOKING AT THE VARIOUS OPERATIONAL MODELS...HAVE
DECIDED TO GO WITH A 25 PERCENT 12Z ECMWF AND A 75 PERCENT 12Z GFS.
WE ARE GETTING TO THE POINT IN THE FORECAST WHERE DIURNAL RISE AND
FALL WILL NOT CUT IT WITH FRONTS MOVING THROUGH AND WAVES OF LOW
PRESSURE RIDING ALONG THE FRONTAL BOUNDARY.
ON WEDNESDAY...LONG WAVE TROUGH WILL BE CARVING ITSELF OUT OVER THE
WESTERN U.S. FIRST WEATHER ISSUE IS THE AMOUNT OF ENERGY THAT WILL
EJECT FROM THIS FEATURE ACROSS THE NORTHERN PLAINS AND INTO CENTRAL
CANADA. GFS IS STRONGER AND FASTER WITH THIS ENERGY WHILE THE ECMWF
IS SLOWER...AND THIS HAS BEEN THE CASE OVER THE LAST SVRL RUNS. THIS
WILL HAVE FRONTAL IMPLICATIONS THROUGH OUR REGION WEDNESDAY INTO
THURSDAY. WITH AFOREMENTIONED BLEND...IT ALLOWS FOR A COLD FRONT TO
MOVE THROUGH THE REGION WEDNESDAY NIGHT...BUT NOT AS FAST AS THE GFS
INDICATES. IN ADVANCE OF THE FRONT...WAA SHOWERS ARE FORECAST TO
BREAK OUT AND LIKELY POPS SEEM REASONABLE AT THIS TIME.
FOR THE PERIOD THURSDAY INTO FRIDAY...THIS TIME FRAME IS SHAPING UP
TO BE INCLEMENT AS COLD FRONT SAGS TO OUR SOUTHEAST AND BECOMES
QUASI STATIONARY AS WAVES OF LOW PRESSURE RIDE ALONG IT. THESE WAVES
WILL BRING A SHOT OF FRONTOGENETIC FORCING TO OUR REGION LATE
THURSDAY INTO THURSDAY NIGHT WITH ANOTHER ROUND OF MID TO UPR LVL
FORCING FRIDAY INTO FRIDAY NIGHT. DURING THIS TIME...COLD AIR WILL
SLOWLY SEEP INTO THE REGION FROM THE NORTHWEST. AS SUCH...THERE WILL
BE SOME WINTRY PCPN TYPE ISSUES AS LOW LEVELS COOL BUT AIR ABOVE
WILL BE SLOWER TO COOL. STILL TO EARLY TO GET SPECIFIC GIVEN THE
THERMAL FIELD OSCILLATIONS AT THIS POINT SO JUST HAVE RAIN/SNOW
MENTIONED. LIKELY POPS STILL SEEM REASONABLE FOR MOST OF THE REGION
WITH EACH WAVE RIPPLING BY.
BY FRIDAY NIGHT INTO SATURDAY...COLD ARCTIC HIGH PRESSURE WILL WEDGE
SOUTHEAST INTO OUR AREA. THIS SHOULD PUSH THE PCPN OUT OF THE AREA
BY SATURDAY. THE HIGH WILL SET UP ACROSS THE REGION SATURDAY NIGHT
AND WILL MOVE EAST BY SUNDAY. THIS SHOULD GIVE THE REGION A DRY BUT
COLD PERIOD OF WEATHER.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AC DECK CONTINUES TO WORK INTO THE REGION AND OVERRUN A LINGERING
SC DECK. LATEST RUNS OF THE RAP AND NAM ARE BOTH INDICATING THAT
ANY SC THAT LINGER ACROSS THE REGION WILL REMAIN VFR.
MEANWHILE...SOME MVFR FOG WILL BE POSSIBLE ACROSS THE NRN TAFS
THRU SUNRISE.
SC AND AC DECKS WILL LINGER ACROSS THE TAFS ON MONDAY...BUT SHOULD
BE VFR. THEN AS A S/W APPROACHES THE REGION AFT 00Z TUESDAY...THE
STALLED FNT ACROSS THE REGION WILL BEGIN TO LIFT N AS A WARM
FRONT. COULD SEE SOME MVFR CIGS AND A FEW SHRA AS THIS FEATURE
LIFTS N.
OUTLOOK...SOME MVFR CEILINGS POSSIBLE THROUGH TUESDAY MORNING. MVFR
CEILINGS AND VISIBILITIES POSSIBLE AGAIN WEDNESDAY INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...SITES
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS TULSA OK
859 PM CST TUE DEC 3 2013
...UPDATE...
.DISCUSSION...
PATCHY DENSE FOG IS BEGINNING TO DEVELOP ACROSS EASTERN OKLAHOMA
AND WESTERN ARKANSAS AS EXPECTED. THE CURRENT FORECAST REMAINS ON
TRACK AND WILL NOT BE UPDATED THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 535 PM CST TUE DEC 3 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOG IS ONCE AGAIN THE MAIN CONCERN TONIGHT. IT IS LIKELY THAT ALL
SITES WILL SEE IFR TO LIFR VISIBILITIES AGAIN IN FOG OVERNIGHT
INTO EARLY WEDNESDAY MORNING. VEERING SURFACE WINDS JUST AHEAD OF
A COLD FRONT WILL HELP SCOUR OUT THE FOG WEDNESDAY MORNING...WITH
VFR CONDITIONS AT ALL SITES BY MIDDAY. WINDS WILL SHIFT TO THE
NORTHWEST AT THE EASTERN OKLAHOMA SITES BEHIND THE COLD FRONT
WEDNESDAY.
PREV DISCUSSION... /ISSUED 352 PM CST TUE DEC 3 2013/
DISCUSSION...
WOW FOLKS...WHAT A FORECAST TODAY. THERE WILL BE SEVERAL ROUNDS OF
WINTRY PRECIPITATION THAT WILL HAVE IMPACTS ON TRAVEL AND POSSIBLY
THE POWER GRID AS WELL. I WILL DIVE INTO EACH FACET OF THE
FORECAST BELOW...ONE BY ONE.
FIRST...OF SOMEWHAT LESS IMPORTANCE...WILL BE FOG POTENTIAL
TONIGHT. FOR THE PAST 2 DAYS WE`VE HAD WIDESPREAD DENSE FOG.
TONIGHT...WHAT I SEE THAT IS DIFFERENT WILL BE THE DEPTH OF THE
NEAR GROUND MOIST LAYER. MODEL MOISTURE PROFILES DRY OUT FROM TOP
TO BOTTOM WITH TIME TONIGHT...ALTHOUGH THERE MAY BE ENOUGH REMNANT
MOISTURE NEAR THE GROUND FOR SOME PATCHY FOG DEVELOPMENT...SOME
POSSIBLY DENSE. FWIW...THE HRRR BREAKS OUT DENSE FOG OVER A GOOD
PORTION OF EASTERN OK THIS EVENING...AND IT HAS BEEN HANDLING THE
FOG WELL THE PAST 2 NIGHTS.
NOW TO THE MEAT OF THIS FORECAST. A VERY AMPLIFIED UPPER PATTERN
IS EVOLVING OVER THE WESTERN CONUS AS I TYPE...WITH A RIDGE NOSING
WELL UP INTO ALASKA...AND A DEEP POSITIVE TILT DOWNSTREAM TROUGH
DEVELOPING OVER THE WESTERN CONUS. THIS HAS CREATED A CROSS-POLAR
FLOW CLEAR FROM SIBERIA DOWN INTO NORTH AMERICA. WORSE YET...THIS
PATTERN WILL LIKELY PERSIST FOR ABOUT A WEEK...SENDING SHOT AFTER
SHOT OF ARCTIC AIR DOWN INTO THE CONUS AS DISTURBANCES ROTATE
AROUND THE POLAR VORTEX OVER CENTRAL CANADA. THE INITIAL SURGE OF
ARCTIC AIR WILL ARRIVE TOMORROW...AND WILL UNDERCUT A STRONG BELT
OF SW FLOW ALOFT DOWNSTREAM FROM THE WESTERN TROUGH. THE FIRST
ROUND OF PRECIP WILL BE FORCED MAINLY BY LOW TO MID LVL
FRONTOGENESIS...WHICH WILL KICK IN BY EARLY THURSDAY. THE MODELS
ARE IN VERY GOOD AGREEMENT ON A RATHER IMPRESSIVE BAND OF PRECIP
FROM SE OK UP INTO NRN AR ON THURSDAY. NE OK WILL BE ON THE FRINGE
OF THE BEST FN FORCING...AND WILL SEE LIGHTER PRECIP AMOUNTS AS A
RESULT. IN FACT...PORTIONS OF OSAGE COUNTY MAY NOT SEE ANYTHING
WITH THIS FIRST ROUND. NAM/GFS TEMP PROFILES SUGGEST THAT A BAND
OF SIGNIFICANT ICING IS POSSIBLE FROM SE OK UP INTO W CNTRL AR AND
PORTIONS OF NW AR. SOME PLACES HERE MAY PICK UP A QUARTER INCH OR
MORE OF ICE ACCUMULATION...WHICH COULD CAUSE POWER OUTAGES AND
SIGNIFICANT TRAVEL ISSUES. A BAND OF SIGNIFICANT SLEET
ACCUMULATION IS POSSIBLE JUST NORTH OF WHERE THE ZR/IP LINE SETS
UP...MOST LIKELY FROM E CNTRL AND EVENTUALLY PORTIONS OF SE OK
INTO W CNTRL AND NW AR AS THE COLDER AIR GETS DEEPER WITH TIME
FROM NORTH TO SOUTH. THIS COULD CAUSE SIGNIFICANT TRAVEL ISSUES AS
WELL. SOME LIGHT SNOW ACCUMULATION IS MOST LIKELY NEAR THE KANSAS
BORDER. THE FN FORCING SHIFTS SOUTHEAST BY THURSDAY EVENING AND
WEAKENS OVER OUR AREA...ENDING THE FIRST ROUND OF PRECIP.
ROUND TWO BEGINS LATE THURSDAY NIGHT INTO FRIDAY...AS A SHORTWAVE
TROUGH EJECTS EAST FROM THE WESTERN TROUGH OVER THE PLAINS. THE
INCREASING QG FORCING WILL BE MORE BROAD AND WILL COVER MORE OF
THE FORECAST AREA THIS GO AROUND. MODELS SUGGEST THAT A NICE WSW-
ENE ORIENTED DEFORMATION ZONE WILL SET UP FROM SOUTH CENTRAL INTO
NORTHEAST OK AND NORTHWEST AR. LAYER TEMP PROFILES FORECAST BY THE
GFS/ECMWF SUGGEST SNOW OR SNOW/SLEET FOR NE OK AND NW AR...WITH
MORE SLEET ACROSS MUCH OF SE OK AND W CNTRL AR. BASED ON QPF...THIS
COULD LEAD TO SEVERAL INCHES OF SNOW/SLEET ACCUMULATION.
HOWEVER...THE WARM NOSE MAY BE STRONG ENOUGH FOR MORE ZR AND THUS
ICE ACCUMULATION ACROSS FAR SE OK INTO W CNTRL AR LATE THURSDAY
NIGHT AS ROUND TWO GETS GOING. BY FRIDAY MORNING...THE WARM LAYER
IS ERODED ENOUGH FROM THE NORTH TO SHIFT THE BEST ICE POTENTIAL
SOUTH AND EAST OF THE FORECAST AREA. BOTH THE GFS/ECMWF SUGGEST
THAT THE QG FORCING WILL SHUT OFF RAPIDLY BY MIDDAY FRIDAY AS THE
WAVE SHEARS OUT AND LIFTS NORTHEAST OVER THE PLAINS. ROUND TWO
WILL LIKELY BRING MORE TRAVEL HEADACHES ACROSS A LARGER PORTION OF
THE FORECAST AREA. POWER INTERRUPTIONS EITHER MAY DEVELOP OR
CONTINUE OVER AREAS THAT HAVE RECEIVED THE MOST ICE ACCUMULATION
FROM THESE FIRST TWO ROUNDS OF PRECIP.
ROUND THREE GETS GOING OVER THE WEEKEND...AS ANOTHER SHORTWAVE
EMBEDDED WITHIN THE WESTERN CONUS LONGWAVE TROUGH EJECTS NORTHEAST
OVER THE PLAINS...AND A BIT FARTHER NORTH THAN THE PREVIOUS WAVE.
IN ADDITION...WITH THE SURFACE FRONT AND BEST MOISTURE NOW SHUNTED
WELL TO OUR SOUTH AND EAST...THERE WILL NOT BE AS MUCH MOISTURE
FOR THIS SYSTEM TO WORK WITH. INCREASING LOW/MID LVL ISENTROPIC
LIFT WILL RESULT IN AT LEAST LIGHT AMOUNTS OF PRECIPITATION
BEGINNING LATE SATURDAY AND INTO SUNDAY. MODEL SOUNDINGS ARE
FAIRLY DRY OVERALL IN THE CRUCIAL -10 TO -15C LAYER...WITH
MOISTURE MAINLY CONFINED BELOW 700MB. THIS WOULD SUGGEST THAT
PATCHY FREEZING DRIZZLE IS A POSSIBILITY AND HAS THUS BEEN ADDED
TO THE GRIDS. THERE ARE SOME HINTS OF PERIODIC MOISTENING DEEP
ENOUGH FOR ICE PRODUCTION...SO I HAVE ELECTED TO USE MULTIPLE
PRECIP TYPES IN THE GRIDS. THE GFS/ECMWF SUGGEST THAT THE WARM LAYER
WILL EXPAND NORTH INTO OUR AREA SOME DURING THIS TIME...AND THUS
ANOTHER ROUND OF MIXED PRECIP IS POSSIBLE...HOWEVER I WILL
REITERATE THAT PRECIP SHOULD REMAIN LIGHT OVERALL. THIS ROUND OF
PRECIP SHOULD END BY SUNDAY EVENING AS THE WARM CONVEYOR AND
RESULTING ISENTROPIC LIFT SHIFTS EAST OF OUR AREA.
FINALLY...BY EARLY NEXT WEEK THE GFS/ECMWF ARE IN GOOD AGREEMENT
THAT THE PERSISTENT WESTERN LONGWAVE TROUGH WILL LIFT OUT AND SHIFT
EAST OVER THE PLAINS. SOME LIFT AND LIMITED MOISTURE COULD SQUEEZE
OUT SOME LIGHT SNOW ON MONDAY. THIS SHOULD END WINTER PRECIP
CHANCES FOR THE TIME BEING...WHEW.
BOTTOM LINE...AN EXTENDED PERIOD OF VERY COLD WEATHER ALONG WITH
SEVERAL ROUNDS OF WINTRY PRECIPITATION ARE EXPECTED. TRAVEL WILL
BE AFFECTED...AND POWER DELIVERY MAY BE AS WELL IN SOME AREAS.
LOWS ON SATURDAY AND TUESDAY MORNING ARE EXPECTED TO DIP DOWN INTO
THE SINGLE DIGITS WITH WIND CHILLS BELOW ZERO OVER PORTIONS OF THE
AREA. GET READY FOLKS.
THE WINTER STORM WATCH WILL BE CONTINUED FOR THE ENTIRE FORECAST
AREA...WITH WARNINGS LIKELY TO FOLLOW EITHER TONIGHT OR WEDNESDAY.
LACY
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER STORM WATCH FROM 6 AM THURSDAY TO 6 PM FRIDAY FOR OKZ054-
OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-
OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-
OKZ071-OKZ072-OKZ073-OKZ074-OKZ075.
WINTER STORM WATCH FROM NOON THURSDAY TO 6 PM FRIDAY FOR OKZ049-
OKZ053-OKZ076.
AR...WINTER STORM WATCH FROM 6 AM THURSDAY TO 6 PM FRIDAY FOR ARZ001-
ARZ002-ARZ010-ARZ011-ARZ019.
WINTER STORM WATCH FROM NOON THURSDAY TO 6 PM FRIDAY FOR ARZ020-
ARZ029.
&&
$$
SHORT TERM...06
AREA FORECAST DISCUSSION
NWS TULSA OK
535 PM CST TUE DEC 3 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOG IS ONCE AGAIN THE MAIN CONCERN TONIGHT. IT IS LIKELY THAT ALL
SITES WILL SEE IFR TO LIFR VISIBILITIES AGAIN IN FOG OVERNIGHT
INTO EARLY WEDNESDAY MORNING. VEERING SURFACE WINDS JUST AHEAD OF
A COLD FRONT WILL HELP SCOUR OUT THE FOG WEDNESDAY MORNING...WITH
VFR CONDITIONS AT ALL SITES BY MIDDAY. WINDS WILL SHIFT TO THE
NORTHWEST AT THE EASTERN OKLAHOMA SITES BEHIND THE COLD FRONT
WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 352 PM CST TUE DEC 3 2013/
DISCUSSION...
WOW FOLKS...WHAT A FORECAST TODAY. THERE WILL BE SEVERAL ROUNDS OF
WINTRY PRECIPITATION THAT WILL HAVE IMPACTS ON TRAVEL AND POSSIBLY
THE POWER GRID AS WELL. I WILL DIVE INTO EACH FACET OF THE
FORECAST BELOW...ONE BY ONE.
FIRST...OF SOMEWHAT LESS IMPORTANCE...WILL BE FOG POTENTIAL
TONIGHT. FOR THE PAST 2 DAYS WE`VE HAD WIDESPREAD DENSE FOG.
TONIGHT...WHAT I SEE THAT IS DIFFERENT WILL BE THE DEPTH OF THE
NEAR GROUND MOIST LAYER. MODEL MOISTURE PROFILES DRY OUT FROM TOP
TO BOTTOM WITH TIME TONIGHT...ALTHOUGH THERE MAY BE ENOUGH REMNANT
MOISTURE NEAR THE GROUND FOR SOME PATCHY FOG DEVELOPMENT...SOME
POSSIBLY DENSE. FWIW...THE HRRR BREAKS OUT DENSE FOG OVER A GOOD
PORTION OF EASTERN OK THIS EVENING...AND IT HAS BEEN HANDLING THE
FOG WELL THE PAST 2 NIGHTS.
NOW TO THE MEAT OF THIS FORECAST. A VERY AMPLIFIED UPPER PATTERN
IS EVOLVING OVER THE WESTERN CONUS AS I TYPE...WITH A RIDGE NOSING
WELL UP INTO ALASKA...AND A DEEP POSITIVE TILT DOWNSTREAM TROUGH
DEVELOPING OVER THE WESTERN CONUS. THIS HAS CREATED A CROSS-POLAR
FLOW CLEAR FROM SIBERIA DOWN INTO NORTH AMERICA. WORSE YET...THIS
PATTERN WILL LIKELY PERSIST FOR ABOUT A WEEK...SENDING SHOT AFTER
SHOT OF ARCTIC AIR DOWN INTO THE CONUS AS DISTURBANCES ROTATE
AROUND THE POLAR VORTEX OVER CENTRAL CANADA. THE INITIAL SURGE OF
ARCTIC AIR WILL ARRIVE TOMORROW...AND WILL UNDERCUT A STRONG BELT
OF SW FLOW ALOFT DOWNSTREAM FROM THE WESTERN TROUGH. THE FIRST
ROUND OF PRECIP WILL BE FORCED MAINLY BY LOW TO MID LVL
FRONTOGENESIS...WHICH WILL KICK IN BY EARLY THURSDAY. THE MODELS
ARE IN VERY GOOD AGREEMENT ON A RATHER IMPRESSIVE BAND OF PRECIP
FROM SE OK UP INTO NRN AR ON THURSDAY. NE OK WILL BE ON THE FRINGE
OF THE BEST FN FORCING...AND WILL SEE LIGHTER PRECIP AMOUNTS AS A
RESULT. IN FACT...PORTIONS OF OSAGE COUNTY MAY NOT SEE ANYTHING
WITH THIS FIRST ROUND. NAM/GFS TEMP PROFILES SUGGEST THAT A BAND
OF SIGNIFICANT ICING IS POSSIBLE FROM SE OK UP INTO W CNTRL AR AND
PORTIONS OF NW AR. SOME PLACES HERE MAY PICK UP A QUARTER INCH OR
MORE OF ICE ACCUMULATION...WHICH COULD CAUSE POWER OUTAGES AND
SIGNIFICANT TRAVEL ISSUES. A BAND OF SIGNIFICANT SLEET
ACCUMULATION IS POSSIBLE JUST NORTH OF WHERE THE ZR/IP LINE SETS
UP...MOST LIKELY FROM E CNTRL AND EVENTUALLY PORTIONS OF SE OK
INTO W CNTRL AND NW AR AS THE COLDER AIR GETS DEEPER WITH TIME
FROM NORTH TO SOUTH. THIS COULD CAUSE SIGNIFICANT TRAVEL ISSUES AS
WELL. SOME LIGHT SNOW ACCUMULATION IS MOST LIKELY NEAR THE KANSAS
BORDER. THE FN FORCING SHIFTS SOUTHEAST BY THURSDAY EVENING AND
WEAKENS OVER OUR AREA...ENDING THE FIRST ROUND OF PRECIP.
ROUND TWO BEGINS LATE THURSDAY NIGHT INTO FRIDAY...AS A SHORTWAVE
TROUGH EJECTS EAST FROM THE WESTERN TROUGH OVER THE PLAINS. THE
INCREASING QG FORCING WILL BE MORE BROAD AND WILL COVER MORE OF
THE FORECAST AREA THIS GO AROUND. MODELS SUGGEST THAT A NICE WSW-
ENE ORIENTED DEFORMATION ZONE WILL SET UP FROM SOUTH CENTRAL INTO
NORTHEAST OK AND NORTHWEST AR. LAYER TEMP PROFILES FORECAST BY THE
GFS/ECMWF SUGGEST SNOW OR SNOW/SLEET FOR NE OK AND NW AR...WITH
MORE SLEET ACROSS MUCH OF SE OK AND W CNTRL AR. BASED ON QPF...THIS
COULD LEAD TO SEVERAL INCHES OF SNOW/SLEET ACCUMULATION.
HOWEVER...THE WARM NOSE MAY BE STRONG ENOUGH FOR MORE ZR AND THUS
ICE ACCUMULATION ACROSS FAR SE OK INTO W CNTRL AR LATE THURSDAY
NIGHT AS ROUND TWO GETS GOING. BY FRIDAY MORNING...THE WARM LAYER
IS ERODED ENOUGH FROM THE NORTH TO SHIFT THE BEST ICE POTENTIAL
SOUTH AND EAST OF THE FORECAST AREA. BOTH THE GFS/ECMWF SUGGEST
THAT THE QG FORCING WILL SHUT OFF RAPIDLY BY MIDDAY FRIDAY AS THE
WAVE SHEARS OUT AND LIFTS NORTHEAST OVER THE PLAINS. ROUND TWO
WILL LIKELY BRING MORE TRAVEL HEADACHES ACROSS A LARGER PORTION OF
THE FORECAST AREA. POWER INTERRUPTIONS EITHER MAY DEVELOP OR
CONTINUE OVER AREAS THAT HAVE RECEIVED THE MOST ICE ACCUMULATION
FROM THESE FIRST TWO ROUNDS OF PRECIP.
ROUND THREE GETS GOING OVER THE WEEKEND...AS ANOTHER SHORTWAVE
EMBEDDED WITHIN THE WESTERN CONUS LONGWAVE TROUGH EJECTS NORTHEAST
OVER THE PLAINS...AND A BIT FARTHER NORTH THAN THE PREVIOUS WAVE.
IN ADDITION...WITH THE SURFACE FRONT AND BEST MOISTURE NOW SHUNTED
WELL TO OUR SOUTH AND EAST...THERE WILL NOT BE AS MUCH MOISTURE
FOR THIS SYSTEM TO WORK WITH. INCREASING LOW/MID LVL ISENTROPIC
LIFT WILL RESULT IN AT LEAST LIGHT AMOUNTS OF PRECIPITATION
BEGINNING LATE SATURDAY AND INTO SUNDAY. MODEL SOUNDINGS ARE
FAIRLY DRY OVERALL IN THE CRUCIAL -10 TO -15C LAYER...WITH
MOISTURE MAINLY CONFINED BELOW 700MB. THIS WOULD SUGGEST THAT
PATCHY FREEZING DRIZZLE IS A POSSIBILITY AND HAS THUS BEEN ADDED
TO THE GRIDS. THERE ARE SOME HINTS OF PERIODIC MOISTENING DEEP
ENOUGH FOR ICE PRODUCTION...SO I HAVE ELECTED TO USE MULTIPLE
PRECIP TYPES IN THE GRIDS. THE GFS/ECMWF SUGGEST THAT THE WARM LAYER
WILL EXPAND NORTH INTO OUR AREA SOME DURING THIS TIME...AND THUS
ANOTHER ROUND OF MIXED PRECIP IS POSSIBLE...HOWEVER I WILL
REITERATE THAT PRECIP SHOULD REMAIN LIGHT OVERALL. THIS ROUND OF
PRECIP SHOULD END BY SUNDAY EVENING AS THE WARM CONVEYOR AND
RESULTING ISENTROPIC LIFT SHIFTS EAST OF OUR AREA.
FINALLY...BY EARLY NEXT WEEK THE GFS/ECMWF ARE IN GOOD AGREEMENT
THAT THE PERSISTENT WESTERN LONGWAVE TROUGH WILL LIFT OUT AND SHIFT
EAST OVER THE PLAINS. SOME LIFT AND LIMITED MOISTURE COULD SQUEEZE
OUT SOME LIGHT SNOW ON MONDAY. THIS SHOULD END WINTER PRECIP
CHANCES FOR THE TIME BEING...WHEW.
BOTTOM LINE...AN EXTENDED PERIOD OF VERY COLD WEATHER ALONG WITH
SEVERAL ROUNDS OF WINTRY PRECIPITATION ARE EXPECTED. TRAVEL WILL
BE AFFECTED...AND POWER DELIVERY MAY BE AS WELL IN SOME AREAS.
LOWS ON SATURDAY AND TUESDAY MORNING ARE EXPECTED TO DIP DOWN INTO
THE SINGLE DIGITS WITH WIND CHILLS BELOW ZERO OVER PORTIONS OF THE
AREA. GET READY FOLKS.
THE WINTER STORM WATCH WILL BE CONTINUED FOR THE ENTIRE FORECAST
AREA...WITH WARNINGS LIKELY TO FOLLOW EITHER TONIGHT OR WEDNESDAY.
LACY
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER STORM WATCH FROM 6 AM THURSDAY TO 6 PM FRIDAY FOR OKZ054-
OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-
OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-
OKZ071-OKZ072-OKZ073-OKZ074-OKZ075.
WINTER STORM WATCH FROM NOON THURSDAY TO 6 PM FRIDAY FOR OKZ049-
OKZ053-OKZ076.
AR...WINTER STORM WATCH FROM 6 AM THURSDAY TO 6 PM FRIDAY FOR ARZ001-
ARZ002-ARZ010-ARZ011-ARZ019.
WINTER STORM WATCH FROM NOON THURSDAY TO 6 PM FRIDAY FOR ARZ020-
ARZ029.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
947 PM CST TUE DEC 3 2013
.UPDATE...
ISSUED AT 945 PM CST TUE DEC 3 2013
MODELS CONTINUE TO HAVE DIFFICULTY WITH THE EVOLUTION OF TONIGHTS
SYSTEM. A LOT OF ENERGY DIVING SOUTHEAST INTO THE TROUGH...AND JUST HOW
MUCH AND WHEN THIS FORCING EJECTS EAST IS THE ISSUE. HRRR AND RAP
HAVE BEEN INCONSISTENT FROM RUN TO RUN AND THUS NOT OF MUCH USE WITH
THIS SYSTEM. RADAR TRENDS SHOW AN EXPANDING AREA OF MAINLY LIGHT SNOW
ALONG AND JUST SOUTH OF INTERSTATE 90...WITH AN EXPANDING AREA OF
MODERATE TO AT TIMES HEAVY SNOW IN NORTH CENTRAL NEBRASKA AND SOUTH
CENTRAL SOUTH DAKOTA. ACTIVITY SEEMS TO NOW BE EXPANDING NEAR THE 700
MB FRONT IN AN AREA OF BROAD ISENTROPIC LIFT AND INCREASING PV
ADVECTION. FRONTOGENESIS NOT AS WELL DEFINED IN LATEST MODEL
RUNS...SUGGESTING WE END UP SEEING A BIT OF A BROADER AREA OF
MODERATE SNOW. BASED ON RADAR TRENDS AND THE LATEST 0Z NAM...SEEMS
LIKE THIS AREA OF SNOW WILL TRACK A BIT NORTHWEST OF THE PREVIOUS
FORECAST...BUT NOT BY MUCH. AND BY AFTER MIDNIGHT...WOULD EXPECT THAT
LATTER AREA OF STEADY SNOW THAT IS CURRENTLY MOVING NORTHEAST...TO
BE FORCED MORE EASTERLY BY THE APPROACHING PV ANOMALY. THIS SHOULD
BRING THIS AREA OF SNOW THROUGH ALL THE COUNTIES CURRENTLY IN THE
HEADLINE. DID ADJUST POPS UPWARD IN THE MORNING TO ACCOUNT FOR THIS
SLOWER TIMING. ALSO WE STAY SATURATED THROUGH THE DAY...AND AS ONE
MORE PUSH OF LIFT MOVES ACROSS DURING THE LATE MORNING AND EARLY
AFTERNOON WE MAY VERY WELL SEE ANOTHER LITTLE BURST OF SNOW DROPPING
ANOTHER INCH OR SO...SORT OF LIKE THE 0Z NAM SHOWS.
STILL LOOKS LIKE A WIDESPREAD 3 TO 6 INCHES IN THE WARNING...WITH
ISOLATED HIGHER AMOUNTS AROUND 7 INCHES...ESPECIALLY IF RATIOS END
UP A BIT HIGHER OR IF WE DO SEE A BIT MORE ENHANCED BANDING. LATEST
TRENDS WOULD SUGGEST THE BEST CHANCE OF SEEING THESE HIGHER AMOUNTS
WILL BE FROM GREGORY TO MITCHELL TO MARHSALL...WITH AMOUNTS ON THE
LOWER SIDE OF THE RANGE AS YOU GET TO THE SOUTHEAST EDGE OF THE
WARNING. HEADLINES LOOK IN GOOD SHAPE...AND THUS NO CHANGES PLANNED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 350 PM CST TUE DEC 3 2013
RELATIVE QUIET PERIOD FROM LATE MORNING INTO EARLY AFTERNOON IS
STARTING TO CHANGE AS LIFT FORCING SPREADS INTO SOUTH CENTRAL SOUTH
DAKOTA IN ADVANCE OF STRONG JET PUNCHING OUT OF THE CENTRAL ROCKIES.
STRONG FRONTOGENETIC FORCING WILL CONTINUE TO EXPAND ENE ALONG MID
LEVEL BOUNDARY THROUGH THE EVENING...AND SHOULD LEAD TO A QUICK
DEVELOPMENT OF SNOW BAND WITH LIFT AND SNOW GROWTH WELL COLLOCATED
IN PROFILES OF MAIN BAND. SHADED TOWARD A SOMEWHAT COOLER THERMAL
PROFILE OVERALL WITH WET BULB EFFECT AND SUPPORT OF EC/SREF. EVEN
WITH THIS...SHOULD BE WARM ENOUGH ALOFT FOR SOME ALTERNATE TYPES IN
TRANSITION AT ONSET...PROBABLY SLEET AND LIGHT FREEZING RAIN BEFORE
A CHANGE TO SNOW. SOME LIGHT ICE ACCUMULATIONS MENTIONED FOR AREAS
AROUND THE IOWA GREAT LAKES...WHERE LOW LEVEL COOL PUSH WILL BE IN
PROXIMITY TO THE LINGERING WARMER AIR ALOFT.
MAIN CHANGE IN THE FORECAST FROM THE MID TO LATE MORNING UPDATE WAS
TO INTRODUCE A WINTER STORM WARNING TO AREAS GENERALLY NORTH OF A
WINDOM TO SIOUX FALLS TO WAGNER LINE. STILL LOOKING AT A BROAD
BANDING OF 4 TO 6 INCHES SNOWFALL...WITH LOCALLY HEAVIER AMOUNTS.
HARD TO PINPOINT THE EXACT LOCATION OF THE HEAVIER BAND...THE
STRONGER REASON FOR UPGRADING TO THE WARNING WAS COMBINING THE
SNOWFALL WITH GUSTY WINDS OF 25 TO 35 MPH. STRONGEST WINDS WILL
FIRST DEVELOP ACROSS THE WESTERN CWA AFTER MIDNIGHT...AND EXPAND
EASTWARD AS LOW PRESSURE INTENSIFIES TO THE SOUTHEAST LATER TONIGHT
AND WEDNESDAY. WINDS WILL BE SLOW TO INCREASE IN THE FAR EAST WITH
BAGGY GRADIENT NEAR THE INVERTED TROUGH...BUT EVENTUALLY WILL
INCREASE AND CREATE PROBLEMS WITH STRONGER GRADIENT BY LATE DAY IN
SW MN. BLOWING SNOW SHOULD REDUCE VISIBILITIES TO AROUND A HALF MILE
AT TIMES...AND COULD BE BRIEFLY LOWER AT TIMES OF FALLING SNOW.
SNOWFALL NOW LOOKING A BIT MORE APT TO CONTINUE INTO WEDNESDAY
ACROSS THE AREA...BUT WILL SLOW UP FROM SOUTHWEST TO NORTHEAST AS
INVERTED TROUGH PULLS EAST...AND UPPER WAVE WANDERS SLOWLY NORTH OF
THE AREA. TEMPERATURES WILL BE IN STRONG SUPPORT OF ICE PROCESSES
DURING THE DAY...SO PERHAPS EVEN FAVORABLE FOR FLURRIES AFTER
MEASURABLE THREAT WANES.
OTHERWISE...SOME AREAS OF DENSE FOG CONTINUE THIS AFTERNOON ACROSS
SOUTHWEST MINNESOTA...AND SO NOT TO CONFUSE WITH OVERALL WINTER
SCENARIO...HAVE NOT ISSUED A SEPARATE ADVISORY ON THIS FEATURE.
THERE WILL LIKELY BE SOME PATCHES OF FREEZING DRIZZLE INTERSPERSED
WITH FLURRIES UNTIL STRONGER FORCING AND DEEPER MOISTURE SPREADS IN
BY THE EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 PM CST TUE DEC 3 2013
ANY LIGHT SNOW WILL TAPER DOWN TO FLURRIES ON WEDNESDAY NIGHT AS THE
SYSTEM PULLS AWAY AND FORCING IS LOST. CONFINED ANY BLOWING SNOW IN
THE EVENING TO AREAS WHICH COULD ACTUALLY RECEIVE AT LEAST A TENTH
OF AN INCH OF SNOW...THOUGH WINDS WILL ONLY MARGINALLY DIMINISH
OVERNIGHT WITH A TIGHT GRADIENT REMAINING ACROSS THE REGION...SO
COULD SEE PATCHY BLOWING SNOW OVER OTHER AREAS. EVEN WITH COLD AIR
ADVECTION CONTINUING...TEMPERATURES WILL REMAIN SOMEWHAT IN CHECK ON
WEDNESDAY NIGHT WITH ABUNDANT CLOUD COVER AND THE ABOVE MENTIONED
WINDS...THOUGH READINGS WILL STILL DROP TO AROUND ZERO BY VERY EARLY
THURSDAY MORNING. WIND CHILLS OVERNIGHT WILL JUST MEET WIND CHILL
CRITERIA IN SOME AREAS...AND MAY HAVE TO DEAL WITH THAT AT SOME
POINT IN REGARD TO HEADLINES...BUT WITH THE CURRENT HEADLINES OUT
DID NOT WANT TO CONFUSE THE MATTER.
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION ON
THURSDAY...AND IT WILL REMAIN BREEZY IN A COLD AIR ADVECTION
REGIME...ALTHOUGH WINDS WILL SLOWLY TAPERING DOWN DURING THE DAY AS
THE GRADIENT RELAXES A BIT. NOT SURE HOW QUICKLY CLOUDS WILL
DECREASE DURING THE DAY...WITH BOTH THE NAM AND GFS HINTING AT
STRATUS LINGERING THROUGH THE DAY. IN LIGHT OF THAT AND WITH SNOW
COVER ACROSS THE AREA WENT ON THE LOW SIDE OF GUIDANCE WITH HIGHS
ONLY IN THE SINGLE DIGITS AND TEENS. BY THURSDAY NIGHT IT DOES LOOK
LIKE THERE SHOULD BE MORE CLEARING...THOUGH WINDS WILL NOT
COMPLETELY DROP OFF...REMAINING CLOSE TO 10 KTS. BECAUSE OF
THAT...AGAIN THINK THAT TEMPERATURES WILL NOT COMPLETELY BOTTOM
OUT...THOUGH WENT ON THE LOW SIDE OF GUIDANCE WITH LOWS FROM NEAR 10
BELOW IN THE NORTH TO NEAR ZERO IN THE FAR SOUTHEAST. IF WINDS WOULD
BECOME CALM THEN IT WILL BE COLDER THAN CURRENTLY FORECASTED.
BY FRIDAY...925 MB TEMPERATURES ARE PROGGED TO BE WELL INTO THE
NEGATIVE UPPER TEENS TO NEGATIVE LOWER 20S C...AND WENT BELOW
GUIDANCE WITH HIGHS IN THE SINGLE DIGITS. FRIDAY NIGHT IS SETTING UP
TO BE THE COLDEST NIGHT OF THE NEXT FEW AS THE HIGH PRESSURE AXIS
MOVES OVERHEAD AND WINDS BECOME NEARLY CALM. THE ONLY FLY IN THE
OINTMENT WILL BE THE POSSIBILITY OF INCREASING MID AND HIGH
CLOUDS...BUT WENT BELOW ALL BLEND GUIDANCE...AND AM STILL PROBABLY
TOO WARM AS MODEL RUNS ARE COLDER. AT THIS POINT...HAVE LOWS IN THE
MID TEENS BELOW ZERO TO THE SINGLE DIGITS BELOW.
IN THE EXTENDED...SATURDAY THROUGH TUESDAY...THE COLD AIR LOOKS TO
BE LOCKED IN THROUGH THE PERIOD. MODELS IN FAIRLY DECENT AGREEMENT
ON BRINGING A CHANCE OF SNOW TO THE AREA SOMETIME IN THE SUNDAY TIME
FRAME...AS A NORTHERN STREAM UPPER LEVEL TROUGH BEGINS TO DROP INTO
THE NORTHERN PLAINS AND A SOUTHERN STREAM WAVE EJECTS OUT OF THE
DESERT SOUTHWEST. A REINFORCING SHOT OF COLD AIR DROPS INTO THE
REGION FOR THE BEGINNING OF NEXT WEEK WITH THE PASSAGE OF THIS
SYSTEM...AND MODELS HINTING THAT IT COULD BE EVEN COLDER THAN THE
UPCOMING COLD SPELL...THOUGH WILL HAVE TO WATCH AS IT IS STILL
PRETTY FAR OUT. IN ANY EVENT...STAYED ON THE LOW SIDE OF GUIDANCE
THROUGH THE PERIOD WITH EXPECTED SNOW COVER. THIS WILL PLAY OUT TO
HIGHS SINGLE DIGITS AND TEENS AND LOWS A FEW DEGREES EITHER SIDE OF
ZERO.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 555 PM CST TUE DEC 3 2013
COMPLEX WEATHER PATTERN SETTING UP ACROSS THE AREA THROUGH THE TAF
PERIOD WITH LOW CEILINGS AND VISIBILITY EXPECTED. CEILINGS WILL
LARGELY BE IFR-LIFR WITH VISIBILITY LIKEWISE DROPPING INTO THE IFR
RANGE AS SNOW EXPANDS ACROSS THE REGION. HEAVIER BAND OF SNOW WILL
RESULT IN LIFR VISIBILITY AT TIMES...AND WHILE EXACT LOCATION OF THE
HEAVIER BAND IS DIFFICULT TO PINPOINT...THE BEST POTENTIAL APPEARS
TO BE FROM SOUTH CENTRAL SD THROUGH KFSD INTO THE KMWM/KMML AREAS IN
SOUTHWEST MN. FAR SOUTHEAST SD AND MOST OF NORTHWEST IOWA WILL SEE
LESSER CHANCES OF PRECIPITATION...THOUGH IFR-LIFR CEILINGS STILL
EXPECTED. IN ADDITION TO FALLING SNOW...INCREASING NORTH-NORTHWEST
WINDS THROUGH THE PERIOD WILL RESULT IN FURTHER REDUCED VISIBILITY
IN BLOWING SNOW AT TIMES.
CONDITIONS WILL IMPROVE GRADUALLY FROM SOUTHWEST TO NORTHEAST AFTER
09Z-12Z...THOUGH EXPECT MVFR CONDITIONS AT BEST...AS SCATTERED LIGHT
SNOW AND AREAS OF BLOWING SNOW CONTINUE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
SDZ068-069.
WINTER STORM WARNING UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
SDZ038>040-050-052>067.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
MNZ089-090.
WINTER STORM WARNING UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
MNZ071-072-080-081-097-098.
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
IAZ001-002.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...CHAPMAN
LONG TERM...JM
AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
312 AM CST MON DEC 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CST MON DEC 2 2013
ALL MODELS SHOW TWO WAVES MOVING ACROSS THE DAKOTAS AND MINNESOTA
THE NEXT 24 H. THE FIRST WAVE IS ALREADY INTO CENTRAL SD PER WATER
VAPOR IMAGERY AND WILL LIKELY BE INTO SW MN AND NW IA BY 00Z. THERE
ARE FEW ECHOES ASSOCIATED WITH THIS SYSTEM AND THOSE ARE PRIMARILY
ACROSS FAR NORTHERN SOUTH DAKOTA. WITH VERY DRY AIR BELOW 10000 FT
AND BEST FORCING FOR ASCENT IN NRN SD...HAVE REMOVED ANY CHC OF
PRECIPITATION WITH THIS WAVE. CLOSE ON ITS HEELS THOUGH IS A SECOND
WAVE. THE NAM IS FASTER AND FARTHER NORTH THAN EITHER THE RAP OR GFS
WITH THIS WAVE. CURRENT TRAJECTORY FROM WATER VAPOR FAVORS THE GFS
AND RAP AND FOLLOWED FOR LATER TONIGHT. THIS PUTS SAME STRONG
PRESSURE ADVECTION ON THE 1.5 PV SFC OVER THE CWA BY MIDNIGHT AND
CONTINUING THROUGH SUNRISE. AGAIN...MOISTURE IS A BIG ISSUE AS ALL
MODELS SHOW A 5000 TO 10000 FT DRY LAYER ABOVE THE SURFACE. FOR MUCH
OF SE SD AND NW IA...THIS DRY AIR EXPECTED TO EVAPORATE ANY
PRECIPITATION THAT DOES REACH THE SURFACE. THE ONLY PLACE THE DRY
AIR MAY BE OVERCOME IS IN SW MN WHERE IT MAY INTERACT WITH THE 850
MB BOUNDARY AND ENHANCE THE LIFT AND SATURATION. WHILE THE DRY AIR
LIKELY WILL LIMIT PCPN EVEN THERE...DID KEEP A SLIGHT CHANCE OF
PRECIPITATION FROM LATE EVENING THROUGH 12Z IN SW MN. TEMPERATURES
ALOFT ARE WELL ABOVE FREEZING...EVEN THE WET BULB TEMPERATURE WILL
BE ABOVE ZERO AND SHOULD MELT ANY PRECIPITATION ALOFT. TEMPERATURES
AT THE SURFACE THIS EVENING EXPECTED TO DROP TO AROUND 30 AND THEN
STEADY OUT AS CLOUDS AND SOUTH WINDS INCREASE. WHILE THERE IS A
POSSIBILITY TEMPERATURES COULD RISE ABOVE FREEZING AS ANY
PRECIPITATION MOVES IN...BELIEVE IT IS MOST LIKELY TO STAY JUST
BELOW FREEZING MOST OF THE NIGHT. SO ANY PRECIPITATION WILL LIKELY
BE A MIX OF FREEZING RAIN AND SLEET. AMOUNTS WILL BE LIGHT...A TRACE
TO A COUPLE HUNDREDTHS...BUT ENOUGH THAT IT COULD SLICK UP ROADS
SHOULD IT FALL.
OTHERWISE...THE PRECIPITATION WILL MOVE OFF BY MONDAY MORNING. THERE
WILL BE A LOT OF CLOUDS AROUND...ESPECIALLY EAST OF THE JAMES RIVER.
IT WILL ALSO BE VERY WARM ALOFT WITH +10C AT 925 MB IN SOUTH CENTRAL
SD WHERE THERE WILL ALSO BE SOME SUN. THEREFORE...EXPECT HIGHS TO
WARM INTO THE LOWER TO MID 50S IN SOUTH CENTRAL SD...WITH UPPER 40S
POSSIBLE OVER MUCH OF SE SD AND INTO NORTHEAST NEBRASKA AND
NORTHWEST IOWA. THE COLDEST TEMPS WILL BE IN SW MN WHERE CLOUDS WILL
BE AROUND MOST OF THE DAY AND WINDS WILL REMAIN S OR SE. BUT EVEN
THERE HIGHS WILL REACH THE LOWER 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 311 AM CST MON DEC 2 2013
MODELS CONTINUE TO TREND FASTER WITH THE SURGE OF COLD AIR AND
TUESDAY NOW UNDER THE GUN FOR POTENTIALLY COLDER TEMPERATURES.
HOWEVER WHAT IS INTERESTING IS AN OCCASIONAL BIAS OF THE GFS WHICH
COLLAPSES THE LEADING TROUGH AND ARCTIC SURGE WHILE THE ECMWF AND
ESPECIALLY THE NAM KEEP THESE TWO BOUNDARIES SEPARATE. IN THE PAST
IT SEEMS WHEN THE NAM AND ECMWF HINT AT THESE TWO BOUNDARIES THEY
GENERALLY VERIFY SO WILL LEAN A LITTLE MORE TOWARDS THE WINDS OF THE
NAM AND ECMWF. BUT UNFORTUNATELY THE NAM AND ECMWF ARE DIFFERENT
ENOUGH THAT BLENDING THESE TWO MODELS IS ALSO DIFFICULT AS THE ECMWF
HAS BEEN THE SLOWEST MODEL EACH RUN AND IS QUITE A BIT SLOWER ON
SHIFTING THE INVERTED TROUGH EAST. FOR NOW WILL GO WITH MAINLY
NORTHWEST WINDS GRADUALLY DEVELOP FROM WEST TO EAST THROUGH THE DAY.
THE MAIN UPPER LEVEL SUPPORT LOOKS TO BE TO THE NORTH OF THE AREA
HOWEVER THE CWA IS WITHIN A TRAILING LOBE OF INSTABILITY ALOFT BUT
FOR NOW THAT AREA OF INSTABILITY IS IN A FAIRLY DRY LAYER SO THE
THREAT FOR PRECIPITATION LOOKS TO BE SOMEWHAT SMALL. STILL LOOKING
LIKE A MAINLY RAIN OR SNOW THREAT FOR THE DAY TUESDAY AS THE INITIAL
PUSH OF COOLER AIR SURGES THROUGH BUT MIXING SHOULD SUPPORT
TEMPERATURES ABOVE FREEZING AT THE SURFACE SO NO REAL THREAT FOR
FREEZING PRECIPITATION. WILL HAVE A SMALL THREAT FOR LIGHT FREEZING
RAIN IN THE FAR NORTHERN CWA BEFORE 15Z BUT AFTER THAT A RAIN OR
SNOW THREAT. THIS CHANCE FOR RAIN OR SNOW SHOULD CHANGE TO ALL SNOW
BY TUESDAY EVENING WITH GRADUALLY DECREASING CHANCES INTO WEDNESDAY.
MODELS DIFFERENT ENOUGH POPS WILL REMAIN MID TO LOW RANGE AND
AMOUNTS WILL REMAIN LIGHT. STILL FEEL THAT THERE WILL BE A THREAT
FOR ABOUT 1 TO 3 INCHES OF SNOW BUT AT THIS TIME JUST NO WAY TO
REALLY SAY WHERE...BUT WILL KEEP THE SLIGHTLY HIGHER AMOUNTS IN THE
NORTHERN CWA.
THE COLDER DRIER AIR REALLY SETTLES IN BY WEDNESDAY EVENING AND NOT
EXPECTING ANY THREAT FOR SNOWFALL WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT. WHILE A FEW FLURRIES MAY BE POSSIBLE THE THREAT IS PRETTY
LOW.
DID DECREASE HIGHS A BIT AGAIN ON WEDNESDAY WITH THE SURGING COLD
AIR...LOOKING AT MAINLY TEENS WITH A FEW LOWER 20S IN NORTHWEST
IOWA. WITH SOME WIND AND CLOUD COVER EXPECTED ON WEDNESDAY NIGHT DID
NOT GO TOO COLD BUT STILL PRETTY MUCH SINGLE DIGITS EVERYWHERE WITH
DIURNAL CHANGES ON THURSDAY ONLY ABOUT 5 DEGREES SO HIGHS IN THE
SINGLE DIGITS TO 10 TO 15 DEGREES. WITH THE NORTHWEST WINDS ON
THURSDAY A WIND CHILL ADVISORY NOT IMPOSSIBLE OVER THE NORTHERN TIER
OR TWO OF COUNTIES LATE WEDNESDAY NIGHT INTO THURSDAY MORNING.
IN THE OUTER PERIODS...FRIDAY THROUGH SUNDAY...COLD AIR REMAINS
FAIRLY ENTRENCHED OVER THE AREA AS AN UPPER LEVEL TROUGH CONTINUES
TO DIG TO THE WEST OF THE AREA. A WAVE DOES TRY TO DEVELOP AND MOVE
ACROSS THE AREA ON SUNDAY WHICH WILL BRING A NORTHWARD KINK OF LESS
COLD AIR INTO THE REGION. IF THIS PATTERN EVOLVES AS THE MODELS ARE
HINTING AT WE WOULD SEE A DECENT CHANCE FOR SNOW AS A FAIRLY STRONG
BAROCLINIC ZONE WOULD DEVELOP AND THERE WOULD BE THE POTENTIAL FOR A
FAIRLY DEEP DENDRITIC ZONE. ALL OF THIS IS PRETTY FAR OUT BUT SOME
OF THE IMPORTANT INGREDIENTS ARE BEING HINTED AT SO WILL BE
SOMETHING TO WATCH FOR. OTHERWISE BELOW NORMAL TEMPERATURES THROUGH
THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 941 PM CST SUN DEC 1 2013
WEAKER LEAD WAVE MOVING THROUGH MINNESOTA AND IOWA...WITH
SECONDARY SYSTEM RACING INTO NORTHWEST SOUTH DAKOTA. LIFT FORCING
WITH SECONDARY WAVE LOOKS TO REMAIN MAINLY NORTH AND EAST OF THE
TAF SITES...WITH POTENTIAL FOR PERHAPS A LITTLE LIGHT FREEZING
RAIN OR RAIN NEAR THE KHON SITE AROUND 07Z-11Z WINDOW.
HOWEVER...NOT WORTH A MENTION WITH VERY LOW PROBABILITY EVENT AT
THIS TIME. EVEN WITH A BIT BETTER THREAT OF PRECIPITATION TOWARD
SW MN...CONDITIONS ARE LIKELY TO REMAIN VFR EVEN IN ANY
PRECIPITATION...GREATER THAN 6 SM AND CEILINGS ABOVE 3000 FT AGL.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...08
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1120 AM CST MON DEC 2 2013
.AVIATION 18Z DISCUSSION...
LOW CLOUDS TO PERSIST THROUGH THE UPCOMING TAF PD. DEWPOINT
DEPRESSIONS WILL LOWER AFT 00Z...ESPECIALLY AT CSV. THUS...IN
ADDITION TO THE LOW CLOUDINESS...VSBYS WILL LOWER AS FOG RETURNS
LATE TONIGHT. SOME IMPROVEMENT IS INDICATED AFT 12Z. SOME PATCHY
DRIZZLE WILL BE POSSIBLE AS WELL AFT 06Z AT CSV.
&&
.PREV DISCUSSION... /ISSUED 947 AM CST MON DEC 2 2013/
UPDATE...
WEAK SHORTWAVE PULLING ACROSS THE DEEP SOUTH THIS HOUR.
THUS...SHOWER ACTIVITY REMAIN SOUTH OF MIDDLE TN BUT CLOUDINESS
SHOULD REMAIN IN PLACE THROUGH THE DAY. DYNAMICS FOR THE REMAINDER
OF THE DAY ARE DIFFICULT TO COME BY. CURRENT FCST DOES CARRY A
CHANCE OF SPRINKLES NORTH AND A SLIGHT CHANCE OF SHOWERS SOUTH.
ISENTROPIC ANALYSIS SHOWS A DECREASE IN CONDENSATION DEFICITS
THROUGH THE DAY IN THE LOWER LEVELS. FURTHERMORE...ISENTROPIC
UPGLIDE IN THE LOWER LEVELS SHOULD CONTINUE. LATEST HRRR INFO DOES
INDICATE SOME LIGHT REFLECTIVITY RETURN LATER TODAY.
THEREFORE...WILL OPT TO CONTINUE WITH THE CURRENT WEATHER GRIDS.
OTW...ONLY OTHER CHANGE WILL BE TO RAISE HIGH TEMPS A DEGREE OR
SO. 18Z GRAPHICAL PROGS SUGGEST THAT TEMPS WILL BE NEARING THE MID
50S FOR MANY AREAS WEST OF THE PLATEAU BY 18Z OR 19Z.
UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 528 AM CST MON DEC 2 2013/
UPDATE...FOR AVIATION.
AVIATION...
12Z TAFS...LOW LEVEL MOISTURE WILL PERSIST...KEEPING MVFR CIGS
ACROSS THE AREA THROUGH THIS PERIOD. ANY -RA WILL BE SCT AND VERY
LIGHT...SO NOT INCLUDING ANY IN TAFS. WINDS WILL BE LIGHT FROM THE
SOUTH THROUGH THE NEXT 24 HOURS.
13
PREV DISCUSSION... /ISSUED 358 AM CST MON DEC 2 2013/
SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
EARLY THIS MONDAY MORNING...SKIES WERE OVERCAST WITH MILD TEMPERATURES
FOR DECEMBER...IN THE 40S. SCATTERED LIGHT SHOWERS WERE MOVING
ACROSS THE FAR SOUTHERN COUNTIES OF MID TN.
TODAY WILL BE MUCH LIKE YESTERDAY...WITH PERSISTENT CLOUDS AND HIGHS
IN THE 50S. THE MAIN SHORTWAVE TROUGH PRODUCING THE SOUTHERN SHOWERS
WILL MOVE EAST...BUT SOME WEAK TROUGHING AND LIFT WILL PERSIST...SO
WE WILL KEEP 20 POPS TODAY. ANY RAINFALL WILL MEASURE LESS THAN ONE
TENTH OF AN INCH.
FOR TONIGHT AND TUESDAY...BOUNDARY LAYER MOISTURE WILL REMAIN
HIGH...BUT NO SIGNIFICANT LIFT IS NOTED...SO CLOUDY SKIES WILL
PRODUCE JUST A FEW SPRINKLES. SOUTHERLY LOW LEVEL WINDS COMBINED
WITH SLIGHTLY BACKING UPPER LEVEL FLOW WILL BRING MILD
TEMPERATURES...CLIMBING INTO THE 60S ON TUESDAY.
FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THERE ARE SOME MODEL
DIFFERENCES. THE GFS AND NAM EJECT A FAIRLY STRONG SHORTWAVE ACROSS
THE NORTHERN PLAINS AND GREAT LAKES WHICH PUSHES A COLD FRONT INTO
OUR AREA ON WEDNESDAY. A FEW GEFS MEMBERS AND THE MORE CONSISTENT
ECMWF SHOW A MUCH WEAKER OR FARTHER WEST SYSTEM...WHICH WOULD HOLD
THE FRONT BACK 24 HOURS SLOWER THAN THE GFS. WE LIKE THIS SOLUTION
BETTER...AND WPC SUPPORTS THE ECMWF ENSEMBLE BLEND. THIS TIMING WILL
MAKE A HUGE DIFFERENCE FOR TEMPERATURES IN THE WEDNESDAY THROUGH
THURSDAY PERIODS. BASED ON THE SLOWER FRONT...WE WILL FORECAST VERY
MILD TEMPERATURES MIDWEEK. HIGHS WEDNESDAY WILL CLIMB WELL INTO THE
60S WITH GUSTY SOUTH WINDS. 70+ WILL BE ACHIEVABLE IF CLOUDS BREAK
UP ENOUGH. LOWS TUESDAY NIGHT AND WEDNESDAY NIGHT WILL BE MANLY IN
THE 50S...BUT THE INCOMING COLD FRONT MAY DROP OUR NORTHWEST COUNTIES
QUICKLY DOWN INTO THE 40S LATE WEDNESDAY NIGHT. THE CHANCE FOR
SHOWERS WILL INCREASE AS THE COLD FRONT APPROACHES.
13
LONG TERM...(THURSDAY THROUGH SUNDAY)
A MESSY PATTERN WITH POTENTIALLY SIGNIFICANT RAINFALL AND WINTER
WX IS EXPECTED. CONTINUED MOIST SOUTHWEST FLOW ALOFT WILL INTERACT
WITH AN ARCTIC INTRUSION. TEMPERATURES WILL BE NEARLY STEADY OR
FALL THURSDAY AS THE COLD FRONT MOVES ACROSS THE MID STATE WITH
WIDESPREAD RAIN. THE RAIN WILL CONTINUE AS DEEP MOISTURE STREAMS
ACROSS THE SLOW MOVING FRONTAL ZONE THURSDAY NIGHT AND FRIDAY.
RAINFALL TOTALS OF 2 TO 4 INCHES ARE EXPECTED. THE COLD AIR WILL
BE GRADUALLY BUILDING FROM THE NORTHWEST...WITH ENOUGH COLD AIR
DEPTH TO PRODUCE SOME MIXED WINTRY PRECIPITATION OVER OUR
NORTHWEST COUNTIES LATE THURSDAY NIGHT AND FRIDAY.
MODELS ARE IN GOOD AGREEMENT WITH A TRANSITION TO WINTRY
PRECIPITATION ACROSS THE AREA FRIDAY NIGHT...WITH THE
PRECIPITATION COMING TO AN END SATURDAY MORNING. RAIN IS EXPECTED
TO TRANSITION TO SLEET AND SNOW...THEN TAPER OFF WITH A BRIEF
PERIOD OF FREEZING DRIZZLE POSSIBLE SATURDAY MORNING. HAZARDOUS
TRAVEL CONDITIONS ARE A GOOD BET DURING THIS TIME PERIOD WITH
TEMPERATURES FALLING INTO THE 20S FRIDAY NIGHT.
WE WILL HAVE DRY WX BY SATURDAY AFTERNOON WITH VERY COLD AND DRY
AIR. OUR TEMPERATURE FORECAST WILL UNDERCUT GFS MOS SUBSTANTIALLY
FOR SATURDAY...AND THROUGH THE ENTIRE WEEKEND BASED ON THE
STRENGTH OF THE COLD DENSE ARCTIC AIR MASS. ANOTHER WAVE AND SURGE
OF MOISTURE WILL BRING ANOTHER SHOT OF WINTRY WX SATURDAY
NIGHT...MOST LIKELY IN THE FORM OF A SNOW AND SLEET MIXTURE. THIS
MIX WILL GRADUALLY TRANSITION TO SLEET...FREEZING RAIN...AND
EVENTUALLY TO ALL RAIN BY MONDAY AS A STRONG WARM NOSE ALOFT
DEVELOPS FROM SOUTHEAST TO NORTHWEST. BEFORE THIS TRANSITION IS
COMPLETE...SOME SIGNIFICANT ICE PROBLEMS WILL BE
POSSIBLE...ESPECIALLY OVER THE NORTHWEST HALF OF THE MID STATE.
19/13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
947 AM CST MON DEC 2 2013
.UPDATE...
WEAK SHORTWAVE PULLING ACROSS THE DEEP SOUTH THIS HOUR.
THUS...SHOWER ACTIVITY REMAIN SOUTH OF MIDDLE TN BUT CLOUDINESS
SHOULD REMAIN IN PLACE THROUGH THE DAY. DYNAMICS FOR THE REMAINDER
OF THE DAY ARE DIFFICULT TO COME BY. CURRENT FCST DOES CARRY A
CHANCE OF SPRINKLES NORTH AND A SLIGHT CHANCE OF SHOWERS SOUTH.
ISENTROPIC ANALYSIS SHOWS A DECREASE IN CONDENSATION DEFICITS
THROUGH THE DAY IN THE LOWER LEVELS. FURTHERMORE...ISENTROPIC
UPGLIDE IN THE LOWER LEVELS SHOULD CONTINUE. LATEST HRRR INFO DOES
INDICATE SOME LIGHT REFLECTIVITY RETURN LATER TODAY.
THEREFORE...WILL OPT TO CONTINUE WITH THE CURRENT WEATHER GRIDS.
OTW...ONLY OTHER CHANGE WILL BE TO RAISE HIGH TEMPS A DEGREE OR
SO. 18Z GRAPHICAL PROGS SUGGEST THAT TEMPS WILL BE NEARING THE MID
50S FOR MANY AREAS WEST OF THE PLATEAU BY 18Z OR 19Z.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 528 AM CST MON DEC 2 2013/
UPDATE...FOR AVIATION.
AVIATION...
12Z TAFS...LOW LEVEL MOISTURE WILL PERSIST...KEEPING MVFR CIGS
ACROSS THE AREA THROUGH THIS PERIOD. ANY -RA WILL BE SCT AND VERY
LIGHT...SO NOT INCLUDING ANY IN TAFS. WINDS WILL BE LIGHT FROM THE
SOUTH THROUGH THE NEXT 24 HOURS.
13
PREV DISCUSSION... /ISSUED 358 AM CST MON DEC 2 2013/
SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
EARLY THIS MONDAY MORNING...SKIES WERE OVERCAST WITH MILD TEMPERATURES
FOR DECEMBER...IN THE 40S. SCATTERED LIGHT SHOWERS WERE MOVING
ACROSS THE FAR SOUTHERN COUNTIES OF MID TN.
TODAY WILL BE MUCH LIKE YESTERDAY...WITH PERSISTENT CLOUDS AND HIGHS
IN THE 50S. THE MAIN SHORTWAVE TROUGH PRODUCING THE SOUTHERN SHOWERS
WILL MOVE EAST...BUT SOME WEAK TROUGHING AND LIFT WILL PERSIST...SO
WE WILL KEEP 20 POPS TODAY. ANY RAINFALL WILL MEASURE LESS THAN ONE
TENTH OF AN INCH.
FOR TONIGHT AND TUESDAY...BOUNDARY LAYER MOISTURE WILL REMAIN
HIGH...BUT NO SIGNIFICANT LIFT IS NOTED...SO CLOUDY SKIES WILL
PRODUCE JUST A FEW SPRINKLES. SOUTHERLY LOW LEVEL WINDS COMBINED
WITH SLIGHTLY BACKING UPPER LEVEL FLOW WILL BRING MILD
TEMPERATURES...CLIMBING INTO THE 60S ON TUESDAY.
FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THERE ARE SOME MODEL
DIFFERENCES. THE GFS AND NAM EJECT A FAIRLY STRONG SHORTWAVE ACROSS
THE NORTHERN PLAINS AND GREAT LAKES WHICH PUSHES A COLD FRONT INTO
OUR AREA ON WEDNESDAY. A FEW GEFS MEMBERS AND THE MORE CONSISTENT
ECMWF SHOW A MUCH WEAKER OR FARTHER WEST SYSTEM...WHICH WOULD HOLD
THE FRONT BACK 24 HOURS SLOWER THAN THE GFS. WE LIKE THIS SOLUTION
BETTER...AND WPC SUPPORTS THE ECMWF ENSEMBLE BLEND. THIS TIMING WILL
MAKE A HUGE DIFFERENCE FOR TEMPERATURES IN THE WEDNESDAY THROUGH
THURSDAY PERIODS. BASED ON THE SLOWER FRONT...WE WILL FORECAST VERY
MILD TEMPERATURES MIDWEEK. HIGHS WEDNESDAY WILL CLIMB WELL INTO THE
60S WITH GUSTY SOUTH WINDS. 70+ WILL BE ACHIEVABLE IF CLOUDS BREAK
UP ENOUGH. LOWS TUESDAY NIGHT AND WEDNESDAY NIGHT WILL BE MANLY IN
THE 50S...BUT THE INCOMING COLD FRONT MAY DROP OUR NORTHWEST COUNTIES
QUICKLY DOWN INTO THE 40S LATE WEDNESDAY NIGHT. THE CHANCE FOR
SHOWERS WILL INCREASE AS THE COLD FRONT APPROACHES.
13
LONG TERM...(THURSDAY THROUGH SUNDAY)
A MESSY PATTERN WITH POTENTIALLY SIGNIFICANT RAINFALL AND WINTER
WX IS EXPECTED. CONTINUED MOIST SOUTHWEST FLOW ALOFT WILL INTERACT
WITH AN ARCTIC INTRUSION. TEMPERATURES WILL BE NEARLY STEADY OR
FALL THURSDAY AS THE COLD FRONT MOVES ACROSS THE MID STATE WITH
WIDESPREAD RAIN. THE RAIN WILL CONTINUE AS DEEP MOISTURE STREAMS
ACROSS THE SLOW MOVING FRONTAL ZONE THURSDAY NIGHT AND FRIDAY.
RAINFALL TOTALS OF 2 TO 4 INCHES ARE EXPECTED. THE COLD AIR WILL
BE GRADUALLY BUILDING FROM THE NORTHWEST...WITH ENOUGH COLD AIR
DEPTH TO PRODUCE SOME MIXED WINTRY PRECIPITATION OVER OUR
NORTHWEST COUNTIES LATE THURSDAY NIGHT AND FRIDAY.
MODELS ARE IN GOOD AGREEMENT WITH A TRANSITION TO WINTRY
PRECIPITATION ACROSS THE AREA FRIDAY NIGHT...WITH THE
PRECIPITATION COMING TO AN END SATURDAY MORNING. RAIN IS EXPECTED
TO TRANSITION TO SLEET AND SNOW...THEN TAPER OFF WITH A BRIEF
PERIOD OF FREEZING DRIZZLE POSSIBLE SATURDAY MORNING. HAZARDOUS
TRAVEL CONDITIONS ARE A GOOD BET DURING THIS TIME PERIOD WITH
TEMPERATURES FALLING INTO THE 20S FRIDAY NIGHT.
WE WILL HAVE DRY WX BY SATURDAY AFTERNOON WITH VERY COLD AND DRY
AIR. OUR TEMPERATURE FORECAST WILL UNDERCUT GFS MOS SUBSTANTIALLY
FOR SATURDAY...AND THROUGH THE ENTIRE WEEKEND BASED ON THE
STRENGTH OF THE COLD DENSE ARCTIC AIR MASS. ANOTHER WAVE AND SURGE
OF MOISTURE WILL BRING ANOTHER SHOT OF WINTRY WX SATURDAY
NIGHT...MOST LIKELY IN THE FORM OF A SNOW AND SLEET MIXTURE. THIS
MIX WILL GRADUALLY TRANSITION TO SLEET...FREEZING RAIN...AND
EVENTUALLY TO ALL RAIN BY MONDAY AS A STRONG WARM NOSE ALOFT
DEVELOPS FROM SOUTHEAST TO NORTHWEST. BEFORE THIS TRANSITION IS
COMPLETE...SOME SIGNIFICANT ICE PROBLEMS WILL BE
POSSIBLE...ESPECIALLY OVER THE NORTHWEST HALF OF THE MID STATE.
19/13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
955 PM CST TUE DEC 3 2013
.UPDATE...
THE COLD FRONT AT 930 PM HAD ALMOST CLEARED SE COLORADO AND WRN
KANSAS AS IT RACES TOWARD THE PANHANDLES. THIS APPEARS TO BE
A FEW HOURS FASTER THAN MODEL PROJECTIONS. THE RAP NOW HAS THE
LEADING EDGE OF THE FRONT INTO THE CHILDRESS AREA BY 11 UTC/5
AM...ABOUT 3 HOURS EARLIER THAN PREVIOUS INDICATIONS. WITH THIS IN
MIND...THE FRONT MAY MAKE BETTER PROGRESS THROUGH THE CWFA BEFORE
STALLING OUT LATE MORNING OR MIDDAY WED. IN FACT...IT IS NOT OUT OF
THE QUESTION THE WIND SHIFT COULD MAKE IT INTO THE CENTRAL SOUTH
PLAINS...ALTHOUGH ALL AVAILABLE GUIDANCE STILL SHOWS SW BREEZES
OUT-DUELING THE FRONT AND LEADING TO A WARM AFTERNOON FOR MOST OF
THE CAPROCK. THEN THE FRONT WILL BLAST THROUGH THE ENTIRE CFWA
WEDNESDAY NIGHT.
THE 00 UTC NAM AND LATEST TTU-WRF AND SREF ALL SUGGEST THAT A
SHORTWAVE APPROACHING FROM THE SW WILL ENHANCE LIFT OVER THE COLD
AIR EARLY THURS MORNING. HOWEVER...AS PREVIOUS DISCUSSION
MENTIONED...MUCH OF THE INITIAL LIFT WILL GO TO SATURATING THE
INITIALLY DRY LOWER-LEVELS AND IT IS UNCERTAIN HOW MUCH PRECIP CAN
ACTUALLY GET WRUNG OUT BEFORE THE FIRST WAVE EXITS MIDDAY. MOST MODEL
PROGS SUGGEST THE BEST PRECIP POTENTIAL WILL BE ACROSS SRN AREAS
WITH THIS FIRST BATCH OF LIFT...WITH SOUNDINGS SHOWING A WINTRY MIX
OF SLEET AND SNOW FOR THE HIGHER ELEVATIONS AND SOME FREEZING RAIN
POTENTIAL OFF THE CAPROCK. THE BETTER CHANCES OF MORE SIGNIFICANT
FROZEN ACCUMULATIONS ARE STILL EXPECTED TO DEVELOP WITH THE
ARRIVAL OF THE MAIN UPPER WAVE THURS EVENING.
A WINTER STORM WATCH CONTINUES FOR THE ENTIRE CFWA BEGINNING 6 AM THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 540 PM CST TUE DEC 3 2013/
AVIATION...
VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS. A COLD FRONT
WITH A NORTHERLY WIND SHIFT IS EXPECTED TO ARRIVE AT KCDS AROUND
14 UTC. GUSTY WEST WINDS ARE EXPECTED AT KLBB DURING THE DAY...SUSTAINED
AT NEARLY 20 KTS....BEFORE SUBSIDING IN THE EVENING. CONSIDERABLE
UPPER-LEVEL CLOUDINESS WILL ALSO CONTINUE TO STREAM OVER THE AREA.
PREV DISCUSSION... /ISSUED 303 PM CST TUE DEC 3 2013/
SHORT TERM...
WEATHER PATTERN IS DOMINATED BY A HIGH AMPLITUDE RIDGE OFF THE WEST
COAST AND A STRONG LOW OVER MANITOBA...A SET-UP CONDUCIVE FOR
SHARPLY COLDER WEATHER...BUT MORE ON THAT IN THE LONG TERM. LEAD
WAVE IN A SERIES OF EMBEDDED DISTURBANCES ROTATING ABOUT
AFOREMENTIONED LOW WILL APPROACH WEDNESDAY EVENING AND WILL HELP
DRIVE INITIAL WIND SHIFT OF THE COLD-SPELL-TO-BE INTO OUR
NORTHEASTERN ZONES.
BREEZY CONDITIONS HAVE PERSISTED TODAY...PARTICULARLY ACROSS THE
NORTHERN ZONES ALONE WITH QUITE DRY LOW LEVELS LEADING TO ELEVATED
FIRE WEATHER CONDITIONS. ERC VALUES REMAIN ANEMIC ESPECIALLY WITH
THE EXTRA GROUND MOISTURE FROM THE LAST SNOW/ICE EVENT. INTO
WEDNESDAY...RH VALUES WILL BE ON THE RISE. FROM A SENSIBLE WEATHER
PERSPECTIVE...PLEASANTLY WARM CONDITIONS WILL PERSIST INTO WEDNESDAY
ALONG WITH INCREASING HIGH CLOUDINESS. THE WINDIEST
CONDITIONS...APPROACHING 20 KTS...SHOULD BE ACROSS THE SOUTHWESTERN
ZONES WELL DISPLACED FROM THE FRONTAL CONVERGENCE ZONE.
LONG TERM...
CERTAINTY IN THE FORECAST HAS INCREASED A BIT FROM THE PREVIOUS
SHIFT ALTHOUGH SOME SIGNIFICANT DIFFERENCES STILL REMAIN TO BE
NEGOTIATED AS THE EVENT DRAWS NEARER. MOIST ISENTROPIC LIFT WILL
BEGIN THURSDAY MORNING AND INCREASE THROUGH THE DAYTIME. GREATEST
LIFT WILL BE ACROSS NEW MEXICO INTO THE WESTERN PANHANDLE WHERE
THERE WILL BE AROUND 30KT OF FLOW ON THE ISENTROPIC SURFACES.
EARLY ON THURSDAY...MID AND UPPER LEVELS WILL BE MOIST AS A WEAK
SHORT WAVE MOVES OVER THE AREA OUT AHEAD OF THE MAIN TROUGH. DRY
AIR IN THE LOWER LEVELS OF THE ATMOSPHERE WILL HAVE TO BE OVERCOME
FOR SIGNIFICANT ACCUMULATIONS TO OCCUR. HOWEVER...BY THE TIME THE
ATMOSPHERE COMPLETELY SATURATES...DEEP LIFT WILL HAVE BEEN ERODED
WITH ONLY ISENTROPIC LIFT REMAINING. BY THE EVENING AS THE MAIN
TROUGH MOVES OUT OVER THE AREA...Q-VECTOR CONVERGENCE WILL BE
MAXIMIZED WITH A STRONG UPPER LEVEL JET. BY DAYBREAK ON
FRIDAY...ISENTROPIC DOWNGLIDE WILL BE RAPIDLY SWEEPING INTO THE
AREA BEHIND THE TROUGH SHUTTING DOWN PRECIPITATION.
ALTHOUGH...FRIDAY WILL LIKELY REMAIN CLOUDY WITH LOW LEVEL
MOISTURE GOING NO WHERE.
A WARM LAYER ALOFT WILL BE MOST PREVALENT NEAR THE SOUTHERN HALF
OF THE FA ADDING ANOTHER LAYER OF DIFFICULTY TO THE FORECAST. VERY
DRY SURFACE AIR MAY PREVENT MUCH PRECIPITATION OVER THE
SOUTHEASTERN TEXAS PANHANDLE EARLY IN THE EVENT ON THURSDAY. ON
THURSDAY...GENERALLY SNOW WILL BE THE PREFERRED PRECIPITATION TYPE
OVER THE SOUTHERN TEXAS PANHANDLE WITH LIGHT FREEZING PRECIPITATION
AND SLEET OVER THE SOUTH PLAINS AND ROLLING PLAINS. GIVEN THE FACT
THAT LIFT WILL ONLY BE COMING FROM ISENTROPIC LIFT...FREEZING
PRECIPITATION ACCUMULATIONS WILL LIKELY BE LIGHT. AS DEEPER LIFT
INCREASES ON THURSDAY NIGHT...THE COLUMN WILL COOL BELOW 0C FOR
MUCH OF THE AREA WITH THE EXCEPTION OF THE SOUTHERN ROLLING
PLAINS. HOWEVER...MID AND UPPER LEVEL DRY AIR WILL BE QUICKLY
WORKING INTO THE REGION FROM THE NORTHWEST ON THURSDAY EVENING. A
MOSTLY SNOW EVENT FOR THE NORTHERN AREAS DURING THURSDAY EVENING
THROUGH FRIDAY MORNING MAY TURN MORE INTO A WINTRY MIX. FREEZING
PRECIPITATION IS STILL THE LIKELY PRECIPITATION TYPE OVER THE
SOUTHERN ROLLING PLAINS. IN ADDITION TO THE WINTRY
PRECIPITATION...TEMPERATURES WILL BE VERY COLD WITH A STRONG
SURFACE RIDGE MOVING INTO THE CENTRAL US ALONG WITH STRONG
MERIDIONAL FLOW TAPING INTO ARCTIC AIR.
THE NEXT TROUGH WILL BE DIGGING INTO THE SOUTHWEST US ON SATURDAY
AND WILL GENERATE ADDITIONAL ISENTROPIC UPGLIDE ON SATURDAY. GIVEN
THE SHALLOW NATURE OF THE MOISTURE AND COLD
TEMPERATURES...FREEZING DRIZZLE APPEARS LIKELY ALTHOUGH
ACCUMULATIONS WILL BE EXTREMELY LIGHT. ANOTHER COLD BLAST MAY MAKE
ITS WAY DOWN INTO THE US AGAIN WITH THE POLAR VORTEX STILL
SPINNING OVER SOUTHERN CANADA AND NO LETTING UP ON THE STRONG
MERIDIONAL FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 38 62 20 25 10 / 0 0 10 50 60
TULIA 37 63 21 25 11 / 0 0 20 30 60
PLAINVIEW 38 66 22 26 13 / 0 0 30 30 60
LEVELLAND 42 67 28 30 16 / 0 0 30 40 60
LUBBOCK 40 69 27 29 16 / 0 0 30 50 60
DENVER CITY 43 65 34 37 17 / 0 0 20 50 60
BROWNFIELD 43 67 29 32 17 / 0 0 30 50 60
CHILDRESS 35 61 25 28 13 / 0 0 20 30 60
SPUR 41 73 26 29 14 / 0 0 30 50 60
ASPERMONT 43 76 27 30 16 / 0 0 40 50 60
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THURSDAY MORNING THROUGH FRIDAY MORNING
FOR THE FOLLOWING ZONES: TXZ021>044.
&&
$$
33/23
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
915 PM CST TUE DEC 3 2013
.UPDATE...
THE MAIN UPDATE ISSUE OF INTEREST IS THAT WE HAVE EXPANDED THE
WINTER STORM WATCH TO COVER THE NW HALF OF NORTH TEXAS. BUT FOR
TONIGHTS FORECAST HAVE LOWERED TEMPERATURES IN A FEW AREAS WHERE
DRY AIR AND GOOD RADIATIONAL COOLING ARE EXPECTED. HAVE ALSO ADDED
A MENTION OF FOG TO THE EAST AND SOUTHEAST ZONES WHERE
TEMPERATURES WILL COOL TO REACH THE DEWPOINTS.
WITHOUT EVEN LOOKING AT THE MODEL DATA THE 0Z UPPER AIR ANALYSIS
FOREBODES AN OMINOUS SETUP FOR WINTER WEATHER FOR NORTH TEXAS. THE
UPPER PATTERN SUGGESTS THAT AT SOME POINT IN THE NEXT FEW
DAYS...EITHER THURSDAY NIGHT/FRIDAY AND/OR THIS WEEKEND THE
COMBINATION OF COLD AIR AND MOISTURE/LIFT ARE GOING TO COME INTO
PLAY TO CREATE A WINTRY MIX OVER MUCH OF THE AREA.
WHILE SURFACE TEMPS ARE THE GO-TO FOR SEEING HOW COLD AN AIR MASS
IS...IT IS ACTUALLY BETTER TO ANALYZE THE LOW-MID LEVEL TEMPS
UPSTREAM TO SEE HOW COLD THE AIR IS THERE. THIS IS BECAUSE AIR
BEHIND A COLD FRONT UNDERGOES SLOW SUBSIDENCE AS IT MAKES ITS WAY
SOUTH FROM THE ARCTIC. BACKWARD TRAJECTORIES OF PAST COLD FRONTS
SHOW US TO CHECK 500-700MB TEMPS IN THE ARCTIC REGION SEVERAL DAYS
OUT...AND 700-850MB TEMPS ACROSS SOUTHERN CANADA 2 TO 3 DAYS OUT
TO GET A ROUGH IDEA ON HOW COLD IT IS GOING TO GET. THUS IT IS
CONCERNING THAT THE UPPER AIR ANALYSIS FROM 00Z REVEALS
EXCEPTIONALLY COLD AIR AT 700MB-850MB ACROSS MONTANA AND INTO
ALBERTA. GREAT FALLS MONTANA HAD A 700MB TEMP OF -24C AND -20C AT
850MB. THESE TEMPS ARE RUNNING 2 TO 3 STANDARD DEVIATIONS BELOW
NORMAL...WHICH IS AKIN TO SAYING THIS WOULD BE NEAR RECORD COLD
IF WE KEPT RECORDS AT THIS POINT IN SPACE. MODEL GUIDANCE HAS BEEN
2-4 DEG C TOO WARM WITH 6-12 HOUR FORECAST TEMPS AT THIS LEVEL AS
WELL...BUT IS BEGINNING TO CATCH ON.
MEANWHILE THE SURFACE ANALYSIS IS SHOWING THE COLD FRONT
BARRELING SOUTH THROUGH THE PLAINS...AND AHEAD OF SCHEDULE...NOW
CROSSING THROUGH MOST OF WESTERN KANSAS. ALL MODELS EXCEPT FOR THE
RAP/NAM ARE MUCH TOO SLOW IN THEIR 3-6 HOUR FORECASTS. THIS IS A
COMMON ISSUE WITH ARCTIC FRONTS WHEN THE 500MB PATTERN IS SITUATED
IN THIS FASHION. LEE SIDE COLD AIR DAMMING IN THE FRONT RANGE OF
THE ROCKIES CAUSES THE SURFACE HIGH TO BUILD FARTHER SOUTH AND
ALLOWS FOR STRONGER EQUATOR-WARD TRANSPORT OF ARCTIC AIR THAN
FORECAST. HIGH RESOLUTION MODELS DO A BETTER JOB AT FORECASTING
THIS...AND THE NAM/WRF MODELS ARE ABOUT THE BEST WE HAVE IN THE
SHORT-MEDIUM TIME RANGE. THE RAP IS EXCELLENT IN THIS SITUATION AS
WELL...BUT ONLY GOES OUT 18 HOURS. THE NAM AND RAP MODELS ARE
INDICATING THE FRONT WILL REACH THE NORTHWEST ZONES AFTER
SUNRISE...AND WILL LIKELY STALL ALONG OR JUST NORTH OF THE I-20
CORRIDOR WEDNESDAY AFTERNOON. THE AIR BEHIND THIS FRONT WILL BE
VERY SHALLOW...AND SUNSHINE WILL MODERATE THE LEADING EDGE OF THIS
AIR GREATLY. THUS HAVE BUMPED UP THE TIMING OF THE FRONT SEVERAL
HOURS AND LOWERED HIGHS INTO THE 60S IN THE NORTHERN ZONES.
WOULD NOT BE SURPRISED TO SEE THE FRONT MOVE THROUGH THE METROPLEX
IN THE AFTERNOON HOURS BUT AGAIN...THE CHANGE IN TEMPS AND WINDS
WILL NOT BE ALL THAT DRASTIC AT FIRST. THE REAL COLD AIR WILL
GRADUALLY INVADE THE REGION THROUGH THE OVERNIGHT HOURS.
THE NEW 00Z NAM HAS COME IN COLDER THURSDAY...AND ESSENTIALLY ALL
GUIDANCE BUT THE SREF IS INDICATING TEMPERATURES NEAR FREEZING
ACROSS THE NORTHWEST ZONES THURSDAY AFTERNOON AS PRECIPITATION
BEGINS TO DEVELOP. SINCE THE AIR IS SO COLD UPSTREAM IN THE SOURCE
REGION...AND THESE FRONTS TEND TO RUN A LITTLE COLDER THAN
MODEL FORECASTS...HAVE BUMPED UP THE TIMING OF THE FREEZING RAIN
AND WINTER STORM WATCH TO THURSDAY AFTERNOON OVER THE NORTHWEST
ZONES. IT IS TOO TOUGH TO SAY WHETHER IMPACTS WILL BEGIN
IMMEDIATELY THURSDAY AFTERNOON...BUT FELT THAT THE WATCH STARTING
AT 0Z WAS CUTTING IT TOO CLOSE.
AGAIN THERE IS GOOD MODEL AGREEMENT REGARDING THE FORECAST FOR
THURSDAY NIGHT AND FRIDAY. HAVE NOT CHANGED ANY OF THE FORECASTED
SENSIBLE WEATHER FROM THE PREVIOUS FORECAST AS IT ALL LOOKS
GOOD. HOWEVER...THERE MAY END UP BEING MORE SLEET THAN FREEZING
RAIN OVER THE NORTHWEST ZONES BUT IT IS TOO EARLY TO TELL FOR
SURE. HOWEVER PLACING A PERCENT LIKELIHOOD OF WINTER STORM WARNING
CRITERIA BEING MET IS TOUGH AT THIS POINT. WPC NOW INDICATES THE
DFW METROPLEX AND NORTHEAST INTO PARIS HAVE A 50-60 PERCENT CHANCE
OF A QUARTER INCH OF ICE ACCUMULATION THURSDAY NIGHT AND FRIDAY
MORNING. WATCH CRITERIA THRESHOLD IS A 50 PERCENT CONFIDENCE LEVEL
WHILE WARNING IS 80 PERCENT. SO GOING BY THIS PIECE OF GUIDANCE WE
SHOULD ISSUE A WATCH NOW. HOWEVER IT IS CONCERNING THE SREF IS
STILL FORECASTING A MARGINAL FREEZING RAIN EVENT FOR THIS REGION
WHICH LOWERS OUR CONFIDENCE. IT IS ALSO CONCERNING THAT THE WARM
NOSE WILL BE VERY WARM...AND RAIN DROPS WILL LIKELY TRANSPORT WARM
AIR TO THE SURFACE...WHICH WOULD INHIBIT ICE ACCUMULATION AND
IMPACTS. ON THE FLIP SIDE IT IS VERY CONCERNING THAT THE AIR
TEMPERATURES MAY STAY BELOW FREEZING FOR MUCH OF THE CWA FRIDAY
AND SATURDAY WITH CLOUDY SKIES. THIS MEANS IF ICE AND/OR SLEET IS
SIGNIFICANT THURSDAY NIGHT AND FRIDAY MORNING...ICE ON ROADS MAY
LINGER INTO SATURDAY OR SUNDAY WHEN COINCIDENTALLY ANOTHER SHOT AT
WINTER PRECIP ARRIVES. THE ISSUE IS THAT THIS EVENT UNLIKE THE
LAST MARGINAL/NON-EVENT DOES HAVE THE POTENTIAL FOR PROLONGED
WINTRY IMPACTS WHICH IS MORE REASON TO RAISE PUBLIC AWARENESS NOW
AND GO AHEAD AND EXPAND THE WATCH SOUTHEASTWARD TO INCLUDE MORE
AREA.
NOTE THIS DOES NOT MEAN THE ENTIRE WATCH AREA WILL BE UPGRADED TO
A WARNING...BUT AT THIS POINT WE BELIEVE THE ENTIRE WATCH AREA
WILL BE IN AT LEAST A WINTER WEATHER ADVISORY THURSDAY NIGHT AND
FRIDAY MORNING. IT IS TOO EARLY TO FINE TUNE ACCUMULATION AMOUNTS
OR ENTERTAIN WHO WILL SEE WHAT IMPACTS...AND THOSE WILL COME LATER
AS CONFIDENCE INCREASES FURTHER.
TR.92
&&
.AVIATION...
/00Z TAFS/
VFR WILL PREVAIL THROUGH THE PERIOD. LIGHT SOUTH TO SOUTHWEST
WINDS WILL PREVAIL THROUGH WEDNESDAY MORNING AND THEN THE WINDS
WILL BECOME MORE WEST-SOUTHWEST TO WESTERLY DURING THE AFTERNOON
HOURS. AN ARCTIC FRONT WILL BE MOVING INTO THE REGION TOMORROW
AND THERE IS A POTENTIAL THE FRONT COULD REACH THE DFW METROPLEX
AIRPORTS WEDNESDAY AFTERNOON OR EVENING. FOR NOW WILL MONITOR THE
PROGRESSION OF THE COLD FRONT AND MAY HAVE TO INCLUDE THE WIND
SHIFT FOR THE FRONT WITH THE 06Z TAFS. SCATTERED TO BROKEN MID TO
HIGH CLOUDS CAN BE EXPECTED THROUGH THE PERIOD.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 356 PM CST TUE DEC 3 2013/
WE ARE ISSUING A WINTER STORM WATCH FROM AREAS ALONG AND NORTHWEST
OF A BRECKENRIDGE TO GAINESVILLE LINE FOR THURSDAY NIGHT THROUGH
FRIDAY. CONFIDENCE IS HIGH ENOUGH WITHIN THIS AREA TO MEET
WARNING CRITERIA OF 1/4 INCH OR MORE OF ICE.
THE ARCTIC FRONT WILL MOVE SOUTH OF THE RED RIVER WEDNESDAY
EVENING AND OUT OF THE SOUTHERN COUNTIES BY MIDDAY THURSDAY.
TEMPERATURES WILL FALL RAPIDLY BEHIND THE FRONT AS TEMPERATURES
UPSTREAM ARE IN THE LOW TEENS OVER WYOMING AND IN THE SINGLE
DIGITS IN CANADA.
PRECIPITATION WILL BE MOSTLY POST-FRONTAL THURSDAY NIGHT-FRIDAY
WITH MODERATE RAINFALL POSSIBLE ALONG A COMANCHE TO PARIS LINE
WHERE RICK ELEVATED MOISTURE MOVES OVER THE ELEVATED FRONTAL
BOUNDARY. THE RAIN WILL CHANGE TO FREEZING RAIN OVER THE
NORTHWEST COUNTIES THURSDAY EVENING AND PROGRESS SOUTHEASTWARD
WITH THE 32F ISOTHERM TO NEAR A SULPHUR SPRINGS TO GOLDTHWAITE
LINE ON FRIDAY. DUE TO UNCERTAINTY IN THE DEPTH OF THE COLD
AIR...WARM SOILS/STREETS...LATENT HEAT RELEASE OF RESIDUAL WATER
FROM RAINFALL AND THE STRENGTH OF THE WARM NOSE ALOFT...THE
LOCATION OF THE RAIN/FREEZING RAIN TRANSITION ZONE WAS HARD TO
DETERMINE... BUT CONFIDENCE WAS HIGH ENOUGH TO ISSUE A WATCH FOR
THE NORTHWEST COUNTIES WITH THIS PACKAGE. THE WATCH MAY BE PUSHED
FURTHER SOUTHEAST IF FUTURE MODEL RUNS PRODUCE HIGHER CONFIDENCE
THAT SIGNIFICANT ICE ACCUMULATIONS WILL OCCUR ELSEWHERE.
THERE WILL BE A LULL IN THE PRECIPITATION FRIDAY NIGHT AS THE
UPPER DISTURBANCE MOVES EAST OF THE REGION. ISENTROPIC UPGLIDE AND
ANOTHER UPPER DISTURBANCE WILL BRING PRECIPITATION BACK TO THE
REGION SATURDAY THROUGH SUNDAY. THIS PRECIPITATION WILL BE LIGHTER
THAN THE PREVIOUS ROUND...BUT WILL BE SLEET AND FREEZING RAIN
DURING THE OVERNIGHT HOURS...BUT GENERALLY LIQUID WHERE DAYTIME
TEMPS WARM ABOVE FREEZING.
THIS WILL BE THE COLDEST AIR OF THE SEASON SO FAR WITH LOWS IN THE
TEENS AND 20S ON SEVERAL NIGHTS. DAYTIME TEMPS WILL TREND WARMER
SUNDAY AND MONDAY...BUT A REINFORCING SHOT OF ARCTIC AIR IS
EXPECTED TO SEND US BACK INTO THE ICEBOX BY TUESDAY MORNING.
75
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 55 77 38 44 28 / 0 5 20 60 90
WACO, TX 49 80 50 52 31 / 0 5 20 50 90
PARIS, TX 49 74 39 45 29 / 0 5 20 70 90
DENTON, TX 49 72 36 39 26 / 0 5 20 60 80
MCKINNEY, TX 48 75 38 42 27 / 0 5 20 60 90
DALLAS, TX 56 79 38 45 28 / 0 5 20 60 90
TERRELL, TX 52 77 42 47 29 / 0 5 20 60 90
CORSICANA, TX 54 77 50 50 31 / 0 5 20 60 90
TEMPLE, TX 52 81 56 56 32 / 0 5 20 50 80
MINERAL WELLS, TX 47 76 36 40 25 / 0 5 20 60 80
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY
AFTERNOON FOR TXZ094-095-104>107-118>120-130>133-141>144.
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
AFTERNOON FOR TXZ091>093-100>103-115>117-129.
&&
$$
/
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1150 AM CST MON DEC 2 2013
.AVIATION...
/18Z TAFS/
RADIATION FOG HAS CONTINUED TO BURN OFF READILY EXCEPT ACROSS
NORTHEAST PARTS OF NORTH TEXAS...BUT THIS DOES NOT INCLUDE ANY
NORTH AND CENTRAL TAF AIRPORTS.
THROUGH 10Z TUESDAY...VFR CONDITIONS WILL PREVAIL WITH JUST
SCATTERED CIRRUS TRANSVERSING OVER THE ARE WITHIN NW FLOW ALOFT.
MIXING WILL ALLOW SSW WINDS 10-15 BY MID AFTERNOON AND CONTINUING
THROUGH THIS EVENING...BEFORE DIMINISHING BACK TO 5-7 KTS.
BY SUNRISE TUESDAY...THERE IS SOME CONFLICT ON DEW POINT SPREADS
WITH THE RUC AND NAM BUFR SOUNDINGS AND GFS LAMP MOS INDICATING AT
LEAST SOME POTENTIAL FOR LIGHT RADIATIONAL FOG ONCE AGAIN. HAVE
PLAYED THE MIDDLE FOR NOW THIS FAR OUT AND AND HAVE INTRODUCED
RESTRICTIONS BACK INTO THE MVFR CATEGORY FOR NOW. IT WILL BE A
MONITORING PROCESS THROUGH THE NIGHT ON SUBSEQUENT FORECASTS
REGARDING ANY VSBY RESTRICTIONS EARLY TUESDAY.
OTHERWISE...VFR CONDITIONS AND SSW WINDS NEAR 10 KTS WILL RETURN
DURING THE DAY TUESDAY.
05/
&&
.UPDATE...
WE ARE NOT ISSUING UPDATED PRODUCTS AT MIDDAY...BUT WILL INSTEAD
CONCENTRATE ON THE EXTENDED FORECAST AND TYPES OF EXPECT
PRECIPITATION. NEWEST MODEL RUNS HAVE A SIMILAR FROPA AS PREVIOUS
RUNS...BUT SEEM TO HAVE BACKED OFF ON THE AMOUNTS OF QPF THAT FALL
ACROSS THE CWA. 75
&&
.PREV DISCUSSION... /ISSUED 418 AM CST MON DEC 2 2013/
AREAS OF DENSE FOG HAVE FORMED ACROSS MUCH OF NORTH AND CENTRAL
TEXAS OVERNIGHT AS SKIES CLEARED AND A WEAK FRONTAL BOUNDARY MOVED
SOUTHWARD. THUS HAVE EXPANDED THE DENSE FOG ADVISORY TO COVER ALL
OF THE FORECAST AREA. THE FOG SHOULD DISSIPATE MID TO LATE MORNING.
SKIES SHOULD BECOME MOSTLY SUNNY BY MIDDAY. TEMPERATURES THIS
AFTERNOON WILL WARM INTO THE MID 60S NORTHEAST TO THE LOWER TO
MID 70S SOUTH.
MILD TEMPERATURES AND DRY WEATHER WILL CONTINUE THROUGH TUESDAY
NIGHT. LOWS TONIGHT WILL BE IN THE LOWER 40S NORTHWEST TO MID 50S
SOUTHEAST AND HIGHS TUESDAY WILL BE THE WARMEST THAT WE WILL SEE
FOR THE NEXT WEEK RANGING FROM THE LOWER 70S NORTHEAST TO LOWER
80S WEST.
THE TIMING OF THE NEXT FRONT IS STILL IN QUESTION AS THE MODELS
CONTINUE TO HANDLE IT DIFFERENTLY. THE GFS IS BY FAR THE FASTEST
SOLUTION BRINGING THE FRONT THROUGH OVERNIGHT TUESDAY NIGHT WHILE
THE ECMWF BRINGS THE FRONT SOUTH OF THE RED RIVER AROUND MIDDAY
WEDNESDAY BUT STALLS IT OUT BEFORE A STRONGER SURGE OCCURS
WEDNESDAY NIGHT. THE NAM INDICATES THAT THE FRONT WILL ENTER
NORTH TEXAS WEDNESDAY MORNING BUT WILL NOT REACH THE SOUTH UNTIL
NEAR DAYBREAK THURSDAY. THE CMC SOLUTION BRINGS THE FRONT INTO
NORTH TEXAS WEDNESDAY MORNING AND THROUGH THE SOUTH DURING THE
AFTERNOON. HAVE BLENDED THE MODELS BRINGING THE FRONT INTO THE
NORTHWEST OVERNIGHT TUESDAY NIGHT BUT NOT THROUGH THE SOUTHEAST
UNTIL WEDNESDAY EVENING.
RAIN CHANCES WILL START OVERNIGHT WEDNESDAY NIGHT AND INCREASE
THROUGH THURSDAY NIGHT AS AN UPPER LEVEL TROUGH APPROACHES.
TEMPERATURES WILL FALL TO BELOW FREEZING BY DAYBREAK FRIDAY
ACROSS THE NORTHWEST HALF OF NORTH TEXAS WHICH SHOULD RESULT IN
SOME FREEZING RAIN LATE THURSDAY NIGHT INTO FRIDAY MORNING. THE
EXACT LOCATION OF THE FREEZING LINE IS STILL QUITE IN QUESTION...
BUT IT LOOKS TO BE NEAR A PARIS TO WAXAHACHIE TO LAMPASAS LINE.
THE NORTHWESTERN ZONES SEEM TO BE THE ALMOST CERTAIN AREAS FOR
FREEZING TEMPERATURES AND THE FREEZING LINE COULD END UP BEING TO
THE SOUTHEAST OF THE CURRENT FORECAST.
THE PRECIPITATION SHOULD COME TO AN END FROM WEST TO EAST LATE
FRIDAY MORNING INTO THE AFTERNOON. WITH ENERGY FROM THE UPPER
LEVEL TROUGH HANGING BACK...THERE WILL BE ADDITIONAL CHANCES
OF PRECIPITATION SATURDAY AND SUNDAY. SOME WINTRY MIX OF RAIN...
FREEZING RAIN AND SLEET WILL BE POSSIBLE. 58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 70 49 77 49 61 / 0 0 5 10 10
WACO, TX 71 51 78 52 71 / 0 0 5 10 10
PARIS, TX 65 48 72 49 60 / 0 5 5 10 10
DENTON, TX 67 45 75 43 58 / 0 0 5 10 10
MCKINNEY, TX 68 47 75 47 60 / 0 0 5 10 10
DALLAS, TX 70 50 78 51 62 / 0 0 5 10 10
TERRELL, TX 68 49 75 52 65 / 0 0 5 10 10
CORSICANA, TX 69 52 77 55 69 / 0 0 5 10 10
TEMPLE, TX 74 52 80 54 73 / 0 0 5 10 10
MINERAL WELLS, TX 69 42 78 40 59 / 0 0 5 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/75
AREA FORECAST DISCUSSION
NWS SPOKANE WA
923 PM PST Sun Dec 1 2013
.SYNOPSIS...
Big changes will arrive to the Inland Northwest this week as a
strong low pressure system pushes into the region. Mild conditions
will continue tonight with very breezy winds and heavy mountain
snow. An arctic cold front will sweep through the region Monday
and temperatures will plunge to some of the coldest readings the
region has experienced over the past couple years. This cold will
likely persist through the week.
&&
.DISCUSSION...
Forecast remains cluttered with strong upper level jet associated
with the wet frontal system slowly sagging south through the
forecast area tonight. HRRR runs suggest some precipitation of a
showery form will fill in a bit in the cold post frontal
conditionally unstable airmass behind the wetter weather along and
ahead of the front exiting to the south/southeast so have resisted
the urge to cut pops. Additionally some locations remain decoupled
at the surface and have not had the stronger upper level winds mix
down yet but momentum mixing from showery precip would allow it to
occur so have resisted urge to decrease wind in those locations
for similar reasons. Forecast temp trend with the cold air coming
down from the north continues to suggest the scenario depicted in
the grids that temperatures will fall through much of the day
Monday which means the high temps expected for Monday may very
well occur not to far from sunrise. /Pelatti
&&
.AVIATION...
06Z TAFS...Wet frontal zone and its associated strong upper level
jet sagging south over the aviation area will allow for a general
transition to less precipitation and more wind overnight and into
tomorrow. Some locations have remained decoupled from the stronger
upper level Southwest to Northwest winds aloft and as such have
had to include a mention of some low level wind shear. Otherwise
the precipitation and its associated low ceilings and visibility
restrictions will keep MVFR and local IFR ceilings in some shape
or form at times and snow levels will lower considerably as we get
colder through the day Monday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 37 18 24 12 17 / 50 30 20 10 0 0
Coeur d`Alene 37 37 16 23 10 16 / 100 50 30 10 10 0
Pullman 38 39 20 25 11 17 / 90 50 20 10 10 10
Lewiston 43 45 24 29 14 21 / 80 50 30 20 10 10
Colville 34 35 16 24 8 18 / 50 40 20 0 0 0
Sandpoint 35 36 17 21 8 14 / 100 80 30 10 10 0
Kellogg 37 38 12 17 6 12 / 100 90 60 20 10 10
Moses Lake 37 40 19 28 16 23 / 10 20 10 0 0 0
Wenatchee 33 38 20 27 14 22 / 10 20 20 0 0 0
Omak 31 34 11 23 8 19 / 10 20 20 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 4 PM PST Monday for Central Panhandle
Mountains.
Winter Storm Warning until 4 PM PST Monday for Northern
Panhandle.
WA...Winter Storm Warning until 4 PM PST Monday for Northeast
Mountains.
Wind Advisory until 4 AM PST Monday for Lower Garfield and
Asotin Counties-Upper Columbia Basin-Washington Palouse.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
858 PM CST TUE DEC 3 2013
.UPDATE...
WILL KEEP DENSE FOG ADVISORY GOING IN SPITE OF SOME OBSERVATIONS
POPPING UP TO 1 TO 2 MILES WITH THE LIGHT RAIN BANDS. THE LAST LIGHT
RAIN BAND SHOULD PUSH NE OF SHEBOYGAN AND FOND DU LAC COUNTIES
AROUND 12 MIDNIGHT WITH VSBYS FALLING BACK TO 1/4 MILE OR LESS
THROUGH THE OVERNIGHT INTO WEDNESDAY MORNING.
LATEST HRRR AND 00Z/04 NAM 12 VISIBILITY FORECASTS INDICATING
IMPROVING VISIBILITIES BEFORE 15Z...AND POSSIBLY BEFORE 12Z IN
THE FAR SE...AS WINDS TURN SOUTHEAST AND INCREASE AS WARM FRONT
ATTEMPTS TO LIFT INTO/THROUGH SRN WI AHEAD OF DEEPENING SURFACE
LOW. WILL LET LATER SHIFT HAVE FULL LOOK AT ALL NEW DATA AND
TRENDS TO SEE IF END TIME OF ADVISORY NEEDS TO BE ADJUSTED.
SOME CONCERN IN THE FAR NW FOR SOME FREEZING FOG AS NE WINDS
PULLING SOME FREEZING TEMPS INTO LOCATIONS NW OF A FOND DU
LAC...PORTAGE TO LONE ROCK LINE. TEMPS EXPECTED TO RISE OVERNIGHT
AS LOW APPROACHES SO WILL NOT ANTICIPATE A HEADLINE THERE BUT WILL
MAKE MENTION OF SLIPPERY SPOTS IN NPW UPDATE.
&&
.AVIATION/06Z TAFS/...
LITTLE IMPROVEMENT IN IFR/LIFR CONDITIONS UNTIL DEEPENING SURFACE
LOW LIFTS PAST TO THE NE AND PUSHES DRIER...COLDER AIR BEHIND
TRAILING COLD FRONT THROUGH SRN WI WEDNESDAY EVENING. MODELS STILL
SHOWING A BAND OF PRECIPITATION ALONG FRONT...WHICH WOULD BE ALL
RAIN AHEAD OF THE FRONT...CHANGING TO SNOW JUST BEHIND THE FRONT
BEFORE ENDING. DO NOT EXPECT ACCUMULATIONS WITH THE BRIEF PERIOD
OF LIGHT SNOW.
&&
.MARINE...
WILL KEEP DENSE FOG ADVISORY GOING AS INCREASINGLY WARM AND MOIST
AIR STREAMS OVER LAKE AS SURFACE LOW APPROACHES EASILY HOLDING
VSBYS AT OR BELOW 1 MILE. SHOULD SEE IMPROVEMENT LATE
MORNING/EARLY AFTERNOON. NO CHANGE TO SMALL CRAFT HEADLINES WITH
ONSHORE NE FLOW CONTINUING OVER NRN ZONES KEEPING WAVES UP WHILE
LIGHTER WINDS IN THE SOUTHERN ZONES NEAR WARM FRONT WILL HOLD
WAVES WELL BELOW CRITERIA. EXPECT ANOTHER ADVISORY TO BE ISSUED
FOR TOMORROW NIGHT AS GUSTY WEST WINDS EXCEED CRITERIA THROUGH
MOST OF THURSDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 322 PM CST TUE DEC 3 2013/
TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE MEDIUM.
WITH SURFACE LOW PRESSURE APPROACHING FROM THE PLAINS...SOUTHERN
WISCONSIN WILL REMAIN NORTH OF THE SURFACE AND 850MB WARM FRONT
THROUGH MOST OF TONIGHT. THEN AS THE BROAD LOW MOVES INTO IL AND
SOUTHERN WI WED MORNING...THE WARM FRONT WILL GRADUALLY LIFT INTO
CENTRAL WI. HOWEVER...THE WEAK PRESSURE GRADIENT WILL ALLOW FOG AND
LOW CLOUDS TO HANG AROUND LONGER.
EXPANDED THE DENSE FOG ADVISORY UP THROUGH ALL OF THE MKX FORECAST
AREA...IN EFFECT UNTIL NOON TOMORROW. ALSO ISSUED A MARINE DENSE FOG
ADVY THROUGH MID WED AFTERNOON. TEMPS AND DEWPOINTS WILL BE ON THE
RISE WED MORNING AS WE GET INTO THE WARM SECTOR WHICH WILL ENHANCE
THE FOG.
AS FOR PRECIP...THANKFULLY IT WILL BE ALL RAIN WITH ABOVE FREEZING
TEMPS TONIGHT THROUGH WED AFTERNOON. LOOK FOR PERIODS OF LIGHT RAIN
AND THEN PERIODS OF DRIZZLE OR NOTHING. BEST CHANCE FOR CONTINUOUS
LIGHT RAIN WILL BE TOWARD CENTRAL WI. FORCING IS LIGHT...BUT THERE
IS 850/700MB WARM AIR ADVECTION...700MB UPWARD MOTION...500MB
VORTICITY ADVECTION WITH NUMEROUS WEAK SHORTWAVES AND VERY WEAK
UPPER DIVERGENCE IN THE EXIT REGION OF AN UPPER JET. THE UPWARD
MOTION AND MOISTURE CONVERGENCE DECREASES LATE TONIGHT AS THE LOW
LEVEL WIND MAX LIFTS NORTHEAST SO EXPECT DIMINISHING PRECIP AND
THEREFORE DENSE FOG ESPECIALLY WED MORNING.
WEDNESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE COLD FRONT WILL EXIT SOUTHEAST WISCONSIN DURING THE EVENING
WITH STRONG COLD AIR ADVECTION IN ITS WAKE. WE COULD SEE SOME
LINGERING LIGHT PRECIPITATION IN THE EVENING...ANY RAIN OR
RAIN/SNOW WILL CHANGE OVER TO LIGHT SNOW BRIEFLY...BEFORE ENDING.
LITTLE OR NO ACCUMULATION IS EXPECTED. LOWS WILL DROP QUICKLY INTO
THE 20S.
THURSDAY THROUGH SATURDAY...FORECAST CONFIDENCE IS HIGH.
ARCTIC HIGH PRESSURE BUILDS IN AND TEMPERATURES WILL TURN VERY
COLD. HIGHS ON THURSDAY SHOULD STILL MANAGE TO HIT THE MID TO
UPPER 20S...BUT FRIDAY AND SATURDAY WILL ONLY SEE HIGHS IN THE
TEENS. THAT WILL BE PUSHING 15 TO 20 DEGREES BELOW NORMAL. LOWS BY
SATURDAY MORNING WILL BE IN THE SINGLE DIGITS. THE HIGH WILL KEEP
IT DRY ACROSS THE AREA.
SUNDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM.
THE GFS/GEM/ECMWF ARE SHOWING A MID LEVEL SHORT WAVE TRACKING FROM
THE SOUTHERN ROCKIES AND INTO THE WESTERN GREAT LAKES SUNDAY
THROUGH SUNDAY NIGHT. THE ECMWF IS STRONGEST WITH THE CYCLOGENESIS
OVER OUR AREA LATE SUNDAY INTO SUNDAY NIGHT. AT THIS POINT...IT/S
NOT A VERY STRONG SYSTEM...BUT IT LOOKS LIKE IT COULD HAVE A
COUPLE TENTHS OF LIQUID WITH IT THAT WOULD TRANSLATE INTO ABOUT 2
TO 3 INCHES OF SNOW GIVEN THE HIGH LIQ/SNOW RATIOS WITHIN THE
PRE-EXISTING COLD AIRMASS OVER THE AREA. THE SNOW SHOULD BE
EXITING THE AREA QUICKLY BY MONDAY WITH COLD HIGH PRESSURE COMING
BACK IN FOR TUESDAY.
AVIATION/00Z TAFS/...
SOUTHERN WI WILL REMAIN ON THE NORTH SIDE OF THE WARM FRONT
THROUGH MUCH OF THE NIGHT AND THEN GET INTO A WEAK PRESSURE
GRADIENT THROUGH WEDNESDAY MORNING. THEREFORE...EXPECT DENSE FOG
WITH 1/4 TO 3/4SM VSBY AND CEILINGS BELOW 500 FEET TO PERSIST
THROUGH WEDNESDAY MORNING. THERE COULD BE BRIEF PERIODS OF
IMPROVEMENT DURING ANY LIGHT RAIN SHOWERS...BUT TOO MUCH UNCERTAINTY
TO TIME THAT CORRECTLY IN THE TAFS.
EXPECTING FURTHER IMPROVEMENT WED AFTERNOON AS THE COLD FRONT
APPROACHES. SOUTH WINDS WILL BECOME WEST AND GUSTY WITH THE COLD
FRONTAL PASSAGE BETWEEN 7 AND 10 PM WED EVENING. SNOW COULD MIX WITH
RAIN ALONG THE FRONT...BUT EXPECT PRECIP TO END SHORTLY AFTER THE
FRONT GETS THROUGH.
MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT AS BRISK SOUTHEAST WINDS
CONTINUE NORTH OF THE NORTH POINT LIGHTHOUSE. EXPECT WAVES TO
SUBSIDE AS WINDS BECOME DUE SOUTH WED AFTERNOON...BUT ESPECIALLY WED
NIGHT AS THEY BECOME WESTERLY BEHIND A STRONG COLD FRONT. BRISK AND
GUSTY WEST NORTHWEST FLOW WILL THEN PREVAIL THE REMAINDER OF THE
WEEK. A SMALL CRAFT ADVISORY WILL BE NEEDED BEHIND THE FRONT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ046-047-051-
052-056>060-062>072.
LM...DENSE FOG ADVISORY UNTIL 3 PM CST WEDNESDAY FOR LMZ643>646.
SMALL CRAFT ADVISORY UNTIL NOON CST WEDNESDAY FOR LMZ643-644.
&&
$$
UPDATE...REM
TONIGHT/WEDNESDAY AND AVIATION/MARINE...MRC
WEDNESDAY NIGHT THROUGH TUESDAY...DAVIS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
332 PM CST MON DEC 2 2013
ADDED AVIATION AND MARINE SECTIONS
.TONIGHT AND TUESDAY...FORECAST CONFIDENCE MEDIUM.
THE FIRST WAVE OF PRECIPITATION IS APPARENT ON RADAR AS A NARROW
BAND WITH DECENT REFLECTIVITY OVER FAR EASTERN MN AND EASTERN IOWA
AT 3 PM THIS AFTERNOON. THIS IS ASSOCIATED WITH A WEAK BAND OF 850-
600MB FRONTOGENESIS AND PERSISTENT 925-850MB WARM AIR ADVECTION AND
MODEST 700MB OMEGA. MOST OBSERVATIONS BENEATH THE BAND SHOW SNOW IN
MN AND RAIN IN IOWA. THIS HAS A STEADY TRACK EASTWARD AND SHOULD
ARRIVE IN MADISON AROUND 1Z OR 7 PM AS PROBABLY WET SNOW. SINCE IT
WILL ONLY LAST UP TO TWO HOURS AND FALLING INTO SURFACE TEMPS ABOVE
FREEZING...NO ACCUMULATION IS EXPECTED. 19Z HRRR MODEL SEEMS TO HAVE
A HANDLE ON THE PRECIP FOR THE EVENING. TIMING FOR MILWAUKEE RAIN
LOOKS LIKE 4Z TO 8Z.
PRECIP TYPE IS MORE UNCERTAIN ACROSS THE NORTHERN MKX FORECAST AREA.
EXPECTING MAINLY SNOW HERE WITH UP TO A HALF INCH OF ACCUMULATION.
SURFACE TEMPERATURES WILL BE A BIT COOLER HERE...SO THERE IS A SMALL
POSSIBILITY FOR FREEZING DRIZZLE IF THERE ARE POCKETS OF AIR BELOW
FREEZING.
EXPECTING A BREAK IN RAIN AFTER THIS FIRST BAND MOVES THROUGH. THERE
COULD BE DRIZZLE AS MID LEVELS DRY OUT A LITTLE PER MODEL SOUNDINGS.
THEN ANOTHER ROUND OF RAIN IS EXPECTED ACROSS SOUTHERN WI TUESDAY
MORNING WHICH COULD PERSIST THROUGH THE AFTERNOON. THERE IS ANOTHER
WAVE OF FRONTOGENESIS...850MB WARM AIR ADVECTION AND 700MB OMEGA
WITH A 500MB VORT MAX. EXPECTING STRATIFORM RAIN OFF AND ON THROUGH
MUCH OF THE DAY TUESDAY WITH LOW CLOUDS AND LIGHT FOG...AS WELL AS
A 10MPH SOUTHEAST BREEZE WITH HIGHER GUSTS.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS LOW TO
MEDIUM.
CONFIDENCE IS CERTAINLY CHALLENGED THIS PERIOD AS THE MAJOR MODEL
SIMULATIONS CONTINUE TO HAVE TWO VERY DIFFERENT SOLUTIONS. WE
HAVE THE MORE AMPLIFIED AND FASTER SOLUTION OF THE GFS/NAM...AND
THE SLOWER...DELAYED AMPLIFICATION OF THE ECMWF/GEM. TO BE THIS
CLOSE TO THE EVENT AND CONTINUE TO SEE SUCH PERSISTENT DISPARITY
IN MODEL RUNS IS PRETTY UNUSUAL. DISCUSSION FROM THE MODEL
DIAGNOSTIC FOLKS SUGGEST THE GFS/NAM ARE TOO AMPLIFIED GIVEN
DOWNSTREAM CHARACTERISTICS. THE APPROACH HAS BEEN TO TAKE A
CONSENSUS/BLEND WITH A STRONGER NOD TOWARD THE SLOWER SOLUTIONS.
FOR US...OUR ISSUES ARE MINOR COMPARED TO OUR NEIGHBORS TO THE
NORTH THAT HAVE TO DEAL WITH THE POTENTIAL OF BIG SNOWFALL
AMOUNTS. WE WILL BE WARM ENOUGH TO KEEP ANY PRECIPITATION IN THE
FORM OF RAIN. WE COULD SEE SOME SNOW MIX IN RIGHT ALONG AND BEHIND
THE COLD FRONT MOVING THROUGH ON WEDNESDAY. JUST WHEN THAT FRONT
MOVES THROUGH WILL HAVE TO GET WORKED OUT OVER THE NEXT COUPLE OF
DAYS. BUT CURRENT THINKING HAS IT COMING THROUGH MADISON AROUND
MID DAY WEDNESDAY AND MILWAUKEE ABOUT MID AFTERNOON.
.WEDNESDAY NIGHT AND BEYOND...FORECAST CONFIDENCE IS MEDIUM.
WE COULD SEE SOME FLURRIES OR VERY LIGHT SNOW WEDNESDAY NIGHT
UNDER A STRONG COLD AIR ADVECTION PATTERN IN THE WAKE OF THE COLD
FRONT. TEMPERATURES WILL FALL PRETTY HARD...BUT HAVE BACKED OFF A
BIT FOR WEDNESDAY NIGHT AND THURSDAY GIVEN THE POTENTIAL FOR A
SLOWER INFLUX OF COLD AIR DEPICTED BY THE ECMWF/GEM SOLUTIONS.
BUT...THE COLD AIR WILL BE WELL ESTABLISHYED BY FRIDAY...
LINGERING THROUGH THE WEEKEND. WE/RE STILL LOOKING AT HIGHS FRIDAY
AND SATURDAY IN THE TEENS...MODERATING A BIT INTO THE 20S BY
SUNDAY AND MONDAY. LOWS WILL BE IN THE SINGLE DIGITS. THE GFS AND
ECMWF ARE BRINGING A WEAKISH LOOKING LOW PRESSURE SYSTEM THROUGH
THE OHIO VALLEY ON SUNDAY THAT COULD BRING SOME LIGHT SNOW TO THE
AREA.
&&
.AVIATION/00Z TAFS/...
MID LEVEL CLOUDS WILL LOWER THROUGHOUT THE EVENING. A NORTH TO SOUTH
ORIENTED BAND OF PRECIPITATION WILL MOVE EASTWARD ACROSS SOUTHERN WI
THIS EVENING...THEN HANG UP IN A WEST TO EAST ORIENTATION ACROSS
CENTRAL WI LATE TONIGHT THROUGH TUESDAY. PRECIP SHOULD START AS WET
SNOW IN MADISON AND NORTH OF MADISON THEN TRANSITION TO RAIN OVER
TIME TONIGHT. MILWAUKEE AND SOUTH WILL BE MAINLY RAIN. WITH SURFACE
TEMPS ABOVE FREEZING FOR THE NIGHT...NOT EXPECTING ACCUMULATION
EXCEPT POSSIBLY IN FOND DU LAC AND SHEBOYGAN AREAS. AFTER THE BAND
PASSES...THERE COULD BE DRIZZLE AND LIGHT FOG AND IFR OR LOWER
CEILINGS LATE TONIGHT THROUGH TUESDAY MORNING.
ANOTHER ROUND OF LIGHT RAIN IS EXPECTED TO SPREAD NORTHEASTWARD
ACROSS SOUTHERN WI TUESDAY MORNING AND PERSIST THROUGH MUCH OF THE
DAY ALONG A WARM FRONT. IFR CIGS SHOULD IMPROVE TO FUEL ALTERNATE
THE AFTERNOON FROM MILWAUKEE AND MADISON SOUTHWARD.
&&
.MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT FOR AREAS NORTH OF THE NORTH
POINT LIGHT FROM MIDNIGHT TONIGHT THROUGH WEDNESDAY MORNING. AREAS
SOUTH OF NORTH POINT LIGHT MAY NEED TO BE ADDED. INCREASING
SOUTHEAST WINDS TONIGHT THROUGH TUE AFTERNOON WILL LEAD TO HIGH
WAVES. EXPECT WAVES TO SUBSIDE AS WINDS BECOME OFFSHORE...SOMETIME
WEDNESDAY MORNING. A STRONG COLD FRONT WILL THEN SWEEP EAST ACROSS
LAKE MI ON WED. BRISK AND GUSTY WNWLY FLOW WILL THEN PREVAIL THE
REMAINDER OF THE WEEK. A SMALL CRAFT ADVISORY MAY BE NEEDED ALL THE
WAY INTO SATURDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST WEDNESDAY
FOR LMZ643-644.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...MRC
TUESDAY NIGHT THROUGH MONDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1123 PM CST SUN DEC 1 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 307 PM CST SUN DEC 1 2013
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT UPPER TROUGH DROPPING DOWN THROUGH WESTERN BRITISH
COLUMBIA...WITH NEARLY ZONAL FLOW DOWNSTREAM ACROSS THE NORTHERN
U.S.. WITHIN THIS ZONAL FLOW...THERE ARE SOME WEAK SHORTWAVES...ONE
OVER SOUTHEAST BRITISH COLUMBIA AND A SECOND IN THE DAKOTAS. DPVA
AND WARM ADVECTION AHEAD OF THIS SECOND SHORTWAVE HAS BEEN SPREADING
MID/HIGH CLOUDS DOWNSTREAM INTO THE FORECAST AREA. SO FAR THE ONLY
SPOT PRECIPITATION HAS BEEN FALLING OUT OF THESE CLOUDS HAS BEEN
ACROSS CENTRAL NORTH DAKOTA. COMPARING THE 12Z BIS AND MPX
SOUNDINGS...MUCH MORE MOISTURE EXISTED ACROSS NORTH DAKOTA...
RELATIVELY SPEAKING AS PRECIPITABLE WATER AMOUNTS ARE ONLY 0.13
INCHES DIFFERENT. FARTHER EAST...HIGH PRESSURE HAS BUILT INTO THE
FORECAST AREA AT THE SURFACE BEHIND LAST NIGHTS COLD FRONT. THE
STRATUS THAT WAS COMING IN AHEAD OF THE HIGH PRESSURE AREA HAS
STALLED MOSTLY NORTH OF HWY 29 IN WI. 925MB TEMPS ARE ABOUT 3C
COOLER TODAY AND AS RESULT...THE SUN HAS ONLY ALLOWED THE
TEMPERATURES TO CLIMB INTO THE 30S.
MODELS ARE ALL IN GOOD AGREEMENT DIVING THE POTENT UPPER TROUGH
OVER WESTERN BRITISH COLUMBIA DIGGING INTO THE PACIFIC NORTHWEST
AND NORTHERN ROCKIES. THIS IN TURN SENDS THE SHORTWAVE IN SOUTHERN
BRITISH COLUMBIA EASTWARD...CROSSING THE FORECAST AREA MONDAY
AFTERNOON. PRIOR TO THIS SHORTWAVE...WE FIRST MUST DEAL WITH THE
SHORTWAVE IN THE DAKOTAS WHICH IS PROGGED TO COME ACROSS THE AREA
THIS EVENING. IT APPEARS ALL THE SHORTWAVE WILL BRING IS CONTINUED
MID/HIGH CLOUDS AS THE LOW LEVELS REMAIN DRY AS SHOWN NICELY IN
THE 12Z MPX SOUNDING. NOW OVERNIGHT...INCREASING 280-295K
ISENTROPIC LIFT OVER THE DAKOTAS AHEAD OF THE APPROACHING BRITISH
COLUMBIA SHORTWAVE WILL LIKELY DEVELOP PRECIPITATION FROM THE
DAKOTAS INTO CENTRAL MINNESOTA. MODELS HAVE SLOWED DOWN THE
PRECIPITATION SPREAD SOUTHEAST INTO THE FORECAST AREA PRIOR TO
12Z...WHICH SEEMS REASONABLE AND HAVE DELAYED THE PRECIPITATION
CHANCES TO LATE IN THE NIGHT. THE BETTER CHANCES FOR PRECIPITATION
COME DURING THE DAY MONDAY AS THE SHORTWAVE CROSSES THE FORECAST
AREA...PROVIDING DPVA AND A SPREAD SOUTHEASTWARD OF THE 280-295K
ISENTROPIC LIFT INTO THE FORECAST AREA. STILL...THERE ARE
DIFFERENCES WITH THE MAIN PRECIP AXIS. THE 01.12Z
CANADIAN...01.00Z/01.12Z ECMWF SUGGEST AN ALIGNMENT FROM CENTRAL
MN INTO NORTHEAST IA/FAR SOUTHWEST WI...THE 01.12Z NAM PLACES IT
MOSTLY NORTH OF I-94...AND THE 01.12Z GFS IS SORT OF A SPLIT
BETWEEN THE TWO. WITH NO CLEAR SIGNAL ON WHICH MODEL GROUP MIGHT
VERIFY...HAVE FOLLOWED A COMPROMISE. THIS COMPROMISE RESULTS IN
LOW CHANCES...20-40...BECAUSE OF THE VARIABILITY OF LOCATION.
FUTURE SHIFTS SHOULD BE ABLE TO RAISE CHANCES AND HONE IN ON AN
ALIGNMENT OF THE PRECIP AXIS.
WITH 925MB AND 850MB TEMPS PROGGED AT OR BELOW 0C ACROSS MUCH OF
THE FORECAST AREA AND EVAPORATIVE COOLING LIKELY TO TAKE PLACE
WHERE IT DOES PRECIPITATE...THINKING THAT THE PRECIPITATION WILL
MAINLY FALL IN THE FORM OF SNOW. THERE MAY BE SOME MIXING WITH
RAIN POSSIBLE IN THE AFTERNOON IF TEMPERATURES WARM INTO THE MID
TO POSSIBLY UPPER 30S AS EXPECTED. NO MODEL IS THAT HEAVY ON
QPF...MOSTLY ON THE ORDER OF A TENTH...MAYBE TWO TENTHS AT MOST.
WITH SNOW TO WATER RATIOS LIKELY IN THE 10-15 TO 1 RANGE AND
DURING THE DAY WHEN THE SUN CAN HAVE SOME IMPACT ON LIMITING
ACCUMULATIONS...THINKING MOSTLY UP TO 1 INCH OF SNOWFALL.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 307 PM CST SUN DEC 1 2013
MAIN LONG TERM FORECAST CONCERNS ARE PRECIPITATION CHANCES AND
TEMPERATURES THROUGH WEDNESDAY...THEN TEMPERATURES BEYOND THAT
AS ARCTIC AIR BEGINS TO FLOW IN.
THE BIGGEST ISSUE TO THE FORECAST IS THE EVOLUTION OF THE
TROUGHING THAT DROPS INTO THE PACIFIC NORTHWEST AND NORTHERN
ROCKIES ON MONDAY. GOOD MODEL CONSENSUS EXISTS THAT THE WESTERN
PART OF THE TROUGH IS GOING TO DIG DEEPLY THROUGH THE WESTERN
U.S.. THE EASTERN PART OF THE TROUGH...ON THE OTHER
HAND...DIFFERENCES SHOW UP WHICH HAVE HUGE IMPLICATIONS TO THE
FORECAST. THE 01.12Z NAM HAS THE EASTERN PORTION OF THE TROUGH
MOVING INTO THE DAKOTAS ON TUESDAY AS A CLOSED LOW...WHEREAS THE
01.12Z GFS/ECMWF/CANADIAN STILL HOLD IT BACK IN SOUTHWEST MONTANA.
THUS...THE NAM EXITS PRECIP THE QUICKEST COME WEDNESDAY AND BEGINS
THE FLOW OF ARCTIC AIR IN THE EARLIEST. BASED ON AVAILABLE MODEL
GUIDANCE...HAVE MOSTLY DISCOUNTED THE NAM AS AN OUTLIER. OF THE
01.12Z GFS/ECMWF/CANADIAN...THE GFS BECOMES THE NEXT FASTEST OF
EXITING THE PRECIPITATION AND BRINGING THE COLD AIR ON
WEDNESDAY...RESULTING FROM MOVING THE UPPER LOW OUT TO THE EAST
QUICKER. HARD TO SAY WHICH OF THIS MODEL GROUP IS CORRECT.
HOWEVER...ITS WORTH NOTING THAT THE ECMWF/CANADIAN HAVE SPED UP
FROM YESTERDAY...REGARDING THE UPPER LOW...EXITING THE
PRECIPITATION AND BRINGING IN THE COLD AIR. THUS...THE FORECAST
FOR MONDAY NIGHT THROUGH WEDNESDAY TAKES A BLEND OF THE
GFS/ECMWF/CANADIAN AND CONTINUITY.
FOR MUCH OF MONDAY NIGHT THROUGH TUESDAY NIGHT...THE FORECAST
AREA REMAINS IN THAT 280-295K ISENTROPIC LIFT ZONE LEFTOVER FROM
MONDAY. THE STRONGEST OF THE LIFT OVERALL STAYS CENTERED NORTH OF
I-90. PRECIPITATION CHANCES INCREASE BECAUSE MOISTURE CONTINUES TO
INCREASE AND DEEPEN. PRECIPITABLE WATER INCREASES FROM NEAR 0.5
INCH ON MONDAY TO 0.6-0.7 INCHES ON TUESDAY. WARMER AIR FLOWING IN
ON SOUTH TO SOUTHEAST 925-850MB WINDS SHOULD ALLOW PRECIPITATION
THAT IS A SNOW OR RAIN/SNOW MIX MONDAY NIGHT INTO TUESDAY MORNING
TO SWITCH MOSTLY OVER TO ALL RAIN BY TUESDAY AFTERNOON. THE ONE
EXCEPTION TO THIS IS OVER TAYLOR COUNTY WHICH IS FARTHEST FROM THE
WARMER AIR ADVECTING IN FROM THE SOUTH. WEDNESDAY IS VERY TRICKY
WITH TEMPERATURES AND PRECIPITATION CHANCES...AS IT HIGHLY DEPENDS
ON THE TIMING OF THE UPPER LOW AND AN EXPECTED COLD FRONTAL
PASSAGE. TEMPERATURES COULD EITHER BE IN THE MID 30S - LOW 40S OR
MID 20S - LOW 30S...WHICH OF COURSE GREATLY AFFECTS PRECIPITATION
TYPE. AS MENTIONED EARLIER...STUCK WITH A COMPROMISE.
SINCE THE LIFT OVERALL IS WEAK FOR MUCH OF THE MONDAY NIGHT
THROUGH WEDNESDAY TIME PERIOD...MUCH OF THE PRECIPITATION SHOULD
BE ON THE LIGHT SIDE. TAYLOR COUNTY AGAIN AS THE GREATEST SHOT OF
SEEING SNOW...BUT WITH THE LIGHT ASPECT TO THE PRECIPITATION AND
LOWER SNOW TO WATER RATIOS...ACCUMULATIONS SHOULD STAY LESS THAN 1
INCH IN EACH 6 HOUR PERIOD. NOW IF YOU TOTAL THIS UP...SNOWFALL
AMOUNTS BY WEDNESDAY EVENING END UP IN THE 4-6 INCH RANGE...BUT
SETTLING...AND POSSIBLY MIXING WITH RAIN ON TUESDAY AFTERNOON...
PUTS A LOT OF DOUBT FOR NEED OF AN ADVISORY AT THIS TIME.
AFTER WEDNESDAY...ITS ALL ABOUT THE ARCTIC AIR AS A LONGWAVE
TROUGH SETS UP FROM THE SOUTHWESTERN U.S. INTO NORTHERN ONTARIO.
THE MAIN REASON FOR ARCTIC AIR COMING IS A POLAR STREAM UPPER
TROUGH THAT DROPS SOUTH OUT OF CENTRAL CANADA AND PROGRESSES
ACROSS THE UPPER MIDWEST ON FRIDAY. AS THIS POLAR TROUGH
APPROACHES...850MB/925MB TEMPS JUST GRADUALLY DROP RIGHT THROUGH
FRIDAY. BY 00Z SATURDAY...850MB STANDARDIZED ANOMALIES ARE DOWN TO
-2.5. IF WE CAN GET SOME SNOW ON WEDNESDAY...EVEN 1 INCH TO STAY
ON THE GROUND...TEMPERATURES COULD BE QUITE A BIT COLDER THAN
FORECAST FOR THURSDAY THROUGH SATURDAY. DOES NOT LOOK LIKE ANY
REAL MEASURABLE SNOW THREAT UNTIL SUNDAY AT THE EARLIEST...AND
THATS IF THE ECMWF IS CORRECT IN TIMING OF BRINGING OUT A
STRONGER WAVE OUT OF THE WESTERN TROUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1124 PM CST SUN DEC 1 2013
A SERIES OF WEAK WEATHER SYSTEMS WILL PASS OVER THE TAF SITES
THROUGH THE PERIOD. IT APPEARS A SLOW LOWERING OF THE CIGS WILL
OCCUR WITH THESE SYSTEMS AS A WARM FRONT APPROACHES AND LIFT
GRADUALLY INCREASES. THE BEST TARGET FOR SOME MEANINGFUL LOWERING
APPEARS TO BE LATER ON MONDAY AND HAVE INCLUDED THIS IN THE TAFS
AS A BIT MORE MOISTURE ARRIVES FROM THE SOUTHWEST. FORECAST
CONTAINS SHRA AS TEMPERATURES SHOULD REMAIN ALMOST CONSTANT
OVERNIGHT MONDAY NIGHT WITH WARM SOUTHEAST FLOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1044 PM CST SUN DEC 1 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 220 PM CST SUN DEC 1 2013
SEVERAL FORECAST ISSUES THIS PERIOD INCLUDING SOUTHERN EXTENT OF
LOW CLOUDS OVERNIGHT...WHETHER LAKE EFFECT SNOW SHOWERS AFFECT
DOOR COUNTY...AND TIMING OF NEXT SYNOPTIC-SCALE SYSTEM.
WEAK LOW-LEVEL WAA TONIGHT AS WINDS BECOME SW-W. AS A RESULT
WOULD EXPECT THE LOW CLOUDS TO STICK AROUND OVER MUCH OF THE
AREA. DIURNAL CU THAT FORMED ALONG SOUTHERN EXTENT OF LOW CLOUDS
MAY DISSIPATE BUT HIGHER CLOUDS UPSTREAM MOVING IN.
REPEATED RUNS OF HRRR AND OTHER SHORT-TERM MODELS INDICATE SOME
LAKE EFFECT SNOW SHOWERS ASSOCIATED WITH POSSIBLE MESOVORTEX OVER
NORTH-CENTRAL LK MICHIGAN TONIGHT WHICH COULD CLIP DOOR COUNTY.
DELTA-T`S ARE MARGINAL BUT WILL CONTINUE WITH SMALL CHANCE OF
SNOW SHOWERS OR FLURRIES IN NORTHERN DOOR. MIN TEMPS SHOULD DROP
INTO THE 20S MOST AREAS AWAY FROM LK MICHIGAN.
ON MONDAY...WAA INCREASES AS NEXT SYSTEM APPROACHES FROM THE
WEST. SOME LIGHT SNOW OR FLURRIES EXPECTED TO MOVE INTO AT LEAST
THE WESTERN HALF OF THE AREA BY LATE AFTERNOON. STILL SOME
QUESTION AS TO HOW FAST SYSTEM BEGINS TO AFFECT AREA...SO WILL
CONTINUE TO USE MODEL BLEND WHICH RESULTS IN TIMING SIMILAR TO
PREVIOUS FORECAST. HIGH TEMP FORECAST A BLEND OF BEST PERFORMING
MOS GUIDANCE WHICH IS NOT FAR OFF FROM PREVIOUS FORECAST.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 220 PM CST SUN DEC 1 2013
A VERY CHALLENGING FORECAST PERIOD THROUGH MID WEEK DUE TO
TIMING ISSUES WITH A DEVELOPING STORM SYSTEM AND PCPN TYPE. THE
POTENTIAL EXISTS FOR WINTER HEADLINES OVER NORTH CENTRAL WISCONSIN
FOR MAINLY SNOW.
STARTING MONDAY NIGHT...NAM AND GFS CONTINUE TO REMAIN A BIT QUICKER
WITH SPREADING THE BAND OF SNOW OVER THE AREA FASTER WITH THE WARM
AIR ADVECTION. OLD ECMWF IS ABOUT 12 HOURS SLOWER WHILE THE GEM
WAS THE AVERAGE. LATEST ECMWF IS CLOSER TO THE GEM TIME WITH THE
INITIAL WAA TOWARD MONDAY NIGHT.
AVAILABLE FORECAST SOUNDINGS DO INDICATE SNOW AT THE START FOR
THE PCPN TYPE WITH AROUND AN INCH OR TWO OF ACCUMULATION BY
TUESDAY MORNING...WITH THE 2 INCH AMOUNTS TOWARD CENTRAL AND NORTH
CENTRAL AND POINTS NORTHWEST. THE AIR COLUMN LIKELY WILL REMAIN
COLD ENOUGH FOR SNOW FOR ANOTHER 2 INCHES ACROSS THE NORTH. ITS
POSSIBLE AN ADVISORY WILL BE NEEDED FOR NORTH CENTRAL AND PARTS OF
FAR NORTHEAST WISCONSIN FOR THIS INITIAL BAND. SNOW AMOUNTS APPEAR
TO DIMINISH DUE TO CONTINUED WAA AND PCPN CHANGING TO RAIN OR A
RAIN SNOW MIX. THE NAM FORECAST SOUNDING FOR RHI CHANGES THE SN
OVER BRIEFLY ZR THEN RAIN TUESDAY NIGHT THEN BACK TO SNOW LATE.
WITH FROST DEPTHS A FEW INCHES DEEP OVER MANY LOCATIONS DUE TO THE
COLD LATER HALF OF NOVEMBER...POTENTIAL OF BRIEF PERIOD ICY ROADS
DUE TO ZR AND COLD GROUND. NOT CONFIDENT OF THE ZR AT THIS TIME
BUT IF THIS BECOMES MORE OF A THREAT...WINTER WEATHER ADVISORIES
MAY BE NEEDED FOR THAT ELEMENT ALONE TOWARD TUESDAY AS WELL.
BLEND OF MEDIUM RANGE MODELS WITH THE H850 LOW TRACKS SUGGESTS THE
SYSTEM PCPN/SNOW TO REMAIN NORTHWEST OF THE AREA BUT CLOSE ENOUGH
TO PRODUCE ANOTHER INCH OR TWO OVER NORTH CENTRAL WISCONSIN. AT
THIS TIME...UP TO 6 INCHES OF SNOW POSSIBLE OVER PARTS OF NORTH
CENTRAL WISCONSIN FROM MONDAY NIGHT INTO WEDNESDAY MORNING. BUT
DUE TO THE SNOW AMOUNTS WILL BE SPREAD OVER A 36-48 PERIOD...NO
WATCH ISSUED AT THIS TIME. ANTICIPATE A LONG DURATION ADVISORY OR
TWO SHORTER WINTER ADVISORIES MAY BE NEEDED TO HANDLE THE SNOW
ACCUMULATION AND OR MIX CLOSER TO THE EVENT.
BITTERLY COLD ARCTIC AIR WILL THEN POUR INTO THE ARE IN THE WAKE
OF THE SYSTEM. WITH NEED TO HAVE A HEALTHY NORTH TO SOUTH GRADIENT
IN TEMPS LATER IN THE WEEK DUE TO THE COLDER TEMPERATURES OVER
THE ANTICIPATED SNOW COVER OVER NORTH CENTRAL WISCONSIN TO
PROBABLY LITTLE OR NO SNOW OVER CENTRAL AND EAST CENTRAL
WISCONSIN. WINDS APPEAR TO WESTERLY FOR SIGNIFICANT LAKE EFFECT
SNOWS TO REACH FAR NORTH CENTRAL WISCONSIN DURING THE ARTIC SURGE.
MEDIUM RANGE RUNS BEGIN TO DEVELOP RETURN FLOW PCPN AGAIN LATE
NEXT WEEKEND AND FOR THE START OF THE NEXT WEEK...WILL KEEP THE
FORECAST DRY THROUGH NEXT WEEKEND FOR NOW.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1042 PM CST SUN DEC 1 2013
LOW CLDS ACRS THE NE PART OF THE FCST AREA WL RELEASE OFF TO THE
NE A BIT AS FLOW ABV THE SFC SWINGS ARND TO THE SW. THAT COULD
ALLOW SOME FG TO DEVELOP LATER TNGT. LOWERING CLDS AHEAD OF THE
NEXT WX SYSTEM WL OVERSPREAD THE AREA MON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION...UPDATE
NWS PEACHTREE CITY GA
1244 AM EST WED DEC 4 2013
.UPDATE...
/ISSUED AT 840 PM EST TUE DEC 3 2013/
HAVE MADE ADJUSTMENTS TO POP GRIDS THROUGH THE EVENING TO ACCOUNT
FOR REDEVELOPMENT OF RAIN ACROSS CENTRAL AND PARTS OF NORTH GA. LOW
LEVEL MOISTURE ADVECTION CONTINUES ACROSS THE REGION AND DEWPOINTS
ARE WELL INTO THE 50S TO LOWER 60S ACROSS CENTRAL AND PARTS OF NORTH
GA AND IN THE UPPER 40S AND 50S ACROSS THE REST OF NORTH GA. WITH
MOISTURE CONTINUING TO ADVECT...IT APPEARS TEMPS WILL REMAIN NEARLY
STEADY FOR THE REST OF THE NIGHT ACROSS THE CWA AND HAVE MADE THE
NECESSARY CHANGES TO TONIGHTS MIN TEMPS. RAIN SHOULD END FROM THE
WEST AFTER MIDNIGHT. SOME PATCHY DENSE FOG IS POSSIBLE AFTER
MIDNIGHT BUT AT THIS TIME WILL NOT ISSUE A DENSE FOG ADVISORY
HOWEVER WILL CONTINUE TO MONITOR THE SITUATION.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
/ISSUED AT 253 PM EST TUE DEC 3 2013/
WARM FRONT SHOULD BE MOVING NORTH THROUGH THE CWA THIS EVENING AND
OVERNIGHT. GFS/NAM KEEP ENHANCED MOISTURE ACROSS THE CWA THROUGH
WEDNESDAY MORNING...AND HRRR IS INDICATING AN EXPANSION OF THE RAIN
AREA AS IT MOVES NORTHEAST TONIGHT. HAVE KEPT LIKELY POPS OVER MUCH
OF THE CENTRAL TO NE ZONES WITH A GRADUAL DECREASE AFTER 06Z. SOME
LINGERING LOW POPS WEDNESDAY MORNING MAINLY NORTH. WEAK UPPER RIDGE
BUILDS OVER THE CWA WEDNESDAY AFTERNOON AND SO HAVE REMOVED THE POPS
FOR THAT TIME. STRONG SOUTHERLY FLOW WILL BRING ANOTHER INCREASE IN
MOISTURE TO THE CWA LATE WEDNESDAY NIGHT AHEAD OF AN APPROACHING
COLD FRONT. HAVE INTRODUCED POPS AGAIN TOWARD THURSDAY MORNING. AIR
MASS LOOKS STABLE FOR THE SHORT TERM...SO HAVE NO MENTION OF
THUNDER. INSTABILITY STARTS TO INCREASE BY 12Z THURSDAY. EXPECT WARM
TEMPERATURES WITH THE STRONG SOUTHERLY FLOW. OVERNIGHT MINS MAY
APPROACH RECORD VALUES.
41
.LONG TERM /THURSDAY THROUGH TUESDAY/...
/ISSUED AT 253 PM EST TUE DEC 3 2013/
ONLY MINOR CHANGES MADE TO THE EXTENDED WITH THIS PACKAGE. REFINED
TIMING OF POPS FOR EARLY THURSDAY AND MADE SOME MINOR ADJUSTMENTS
MAINLY TO LOW TEMPS THROUGH THE EXTENDED. GUIDANCE COMING INTO
SLIGHTLY BETTER AGREEMENT FOR THE FINAL FROPA AFTER THE WEEKEND
CAD EVENT /GFS COMING MUCH BETTER IN LINE WITH THE ECMWF/ SO MADE
SOME ADDITIONAL ADJUSTMENTS TO TEMPS EARLY NEXT WEEK...BUT OVERALL
VERY LITTLE CHANGE. STILL SOME CONCERN ABOUT THUNDERSTORMS
THURSDAY AND FRIDAY AFTERNOON...WITH INCREASING CONCERN FOR
ISOLATED SEVERE. SHERB VALUES HOVER JUST BELOW THE CRITICAL
THRESHOLD OF 1 FOR HIGH SHEAR LOW CAPE SEVERE WEATHER BOTH
AFTERNOONS AND SPC HAS ADDED A GENERAL THUNDER AREA FOR DAY 3
/THURSDAY/. WILL CONTINUE TO MONITOR EVOLUTION OF THE FORECAST.
TDP
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED AT 405 AM EST TUE DEC 3 2013/
AN UNSETTLED WEATHER PATTERN WILL PREDOMINATE FOR MUCH OF THE
EXTENDED PERIOD.
CHANCES FOR LIGHT RAIN WEDNESDAY NIGHT INCREASING OVER MAINLY N GA
AS AN INCREASINGLY WARM AND MOIST SOUTHERLY LOW LEVEL FLOW
CONTINUES AHEAD OF A SLOW MOVING COLD FRONT MOVING ACROSS THE MID
U.S.
THE GFS AND EUROPEAN ARE SIMILAR WITH BRINGING THE FRONT TO THE TN
VALLEY LATE THURSDAY WITH SHOWERS LIKELY FOR N AND PORTIONS OF
CENTRAL GA WITH SMALL CHANCES FOR THUNDERSTORMS. MUCAPE FORECAST IN
THE 200-600 RANGE. FOR THE MOST PART PRECIP EXPECTED TO BE LIGHT AND
POSSIBLY BRIEFLY MODERATE.
FRONT EXPECTED TO MOVE INTO N GA FRIDAY AND TO CENTRAL TO S GA LATE
SATURDAY. MAINLY SMALL THUNDERSTORM CHANCES ASSOCIATED AS AN AXIS OF
MUCAPE MOVES WITH THE FRONT INTO FRIDAY NIGHT BEFORE WEAKENING.
HIGHEST POPS EXPECTED TO BE OVER N GA FRIDAY/FRIDAY NIGHT. SATURDAY
POPS FOR CENTRAL GA MAY NOT BE HIGH ENOUGH WITH CHANCE SHOWERS
FORECAST.
THE TREND FOR MUCH WARMER TEMPERATURES WILL CONTINUE UNTIL THE FRONT
PASSES BY. EXPECTING NEAR-RECORD OR RECORD WARM MIN TEMPS FOR
FRIDAY MORNING.
WITH HIGH PRESSURE MOVING ACROSS THE NORTHERN STATES SATURDAY NIGHT
AND SUNDAY...GFS AND EUROPEAN ARE SIMILAR WITH FORECASTING A COLD
AIR DAMMING EVENT THAT WILL INCREASE RAIN CHANCES ACROSS N AND
PORTIONS OF CENTRAL GA. BY LATE DAY SUNDAY THE GFS AND EUROPEAN
BEGIN TO DIFFER THAT BECOMES EVEN GREATER THROUGH MONDAY. THE GFS
MOVES ANOTHER FRONT ACROSS THE AREA MONDAY DRYING THINGS OUT BY DAYS
END. THE EUROPEAN IS MUCH SLOWER WITH THE FRONT OVER NW GA AT DAYS
END MONDAY MAKING THE FORECAST HIGH UNCERTAIN.
BDL
&&
.AVIATION...
06Z UPDATE...
LIFR CIGS WITH AREAS OF DENSE FOG HAVE SETTLED IN OVER ATHENS AND
THE ATLANTA TAF SITES...WITH CSG AND MCN EXPECTED TO FOLLOW SOON.
THE LIFR-IFR CIGS WILL PERSIST THROUGH 16-17Z THIS MORNING...WITH A
SLOW IMPROVEMENT TO POSSIBLY LOW VFR CIGS BY 19-20Z TODAY. BUT THIS
WILL BE BRIEF AS MVFR CIGS RETURN BY 00-02Z THU...THEN BACK DOWN TO
LIFR BY 08-09Z THU MORN. EXPECT AREAS OF DENSE FOG AGAIN TONIGHT
WITH VISIBILITIES 1/2SM OR LESS BY 08-09Z AS WELL. NEAR CALM SE
WINDS THIS MORNING WILL BECOME SW BY 18-19Z WITH SPEEDS GENERALLY
7KTS OR LESS. A LIGHT SSE WIND WILL RETURN LATER TONIGHT.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON ALL ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 52 68 57 72 / 70 20 20 40
ATLANTA 55 69 62 72 / 60 20 20 50
BLAIRSVILLE 49 63 57 67 / 50 20 30 60
CARTERSVILLE 52 68 60 72 / 50 20 30 50
COLUMBUS 57 75 65 76 / 60 10 20 40
GAINESVILLE 50 65 59 69 / 60 20 30 50
MACON 55 74 61 75 / 70 10 20 30
ROME 53 69 61 73 / 50 20 40 60
PEACHTREE CITY 51 70 60 73 / 70 10 20 50
VIDALIA 57 76 59 76 / 40 10 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...41/39
LONG TERM....TDP
AVIATION...39
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1150 PM CST TUE DEC 3 2013
.UPDATE...
ISSUED AT 941 PM CST TUE DEC 3 2013
WARM FRONT NEAR QUAD CITIES ATTIM...WITH WIDESPREAD DENSE FOG
CONTINUING TO BE FOUND NORTH OF THE BOUNDARY. THE WARM
FRONT HAS NOT MOVED MUCH THIS EVENING WITH AS AXIS OF PRESSURE
RISES PASSING THROUGH. GIVEN THIS ALONG WITH LIGHT WINDS AND
ABUNDANT HAVE BEEN GETTING REPORTS OF PATCHY TO AREAS OF DENSE
FOG IN SOUTHEAST CWA SOUTH OF THE WARM FRONT. WITH THINGS
UNCHANGED NEXT FEW HOURS BELIEVE WILL SEE SOME EXPANSION TO THE
DENSE FOG AND HAVE GONE AHEAD AND ADDED REMAINING SOUTHEAST CWA
COUNTIES INTO DENSE FOG ADVISORY. MAY ACTUALLY BE ABLE TO TRIM
THE ADVISORY LATER TONIGHT ESPECIALLY FROM QUAD CITIES E/SE IF THE
WARM FRONT LIFTS NORTH AS MODELS SUGGEST ALLOWING FOR SLIGHT
WARMING AND INCREASE IN WINDS TO ABATE WIDESPREAD DENSE FOG.
&&
.SYNOPSIS...
ISSUED AT 340 PM CST TUE DEC 3 2013
WARM FRONT REACHING FROM DEVELOPING LOW OVER SE CO REACHED E-NE
ACROSS CENTRAL KS TO S CENTRAL IA TO N CENTRAL IL THIS AFTERNOON. AT
21Z...SURFACE ANALYSIS AND VISIBLE SATELLITE IMAGERY INDICATED THE
BOUNDARY BETWEEN FAIRFIELD AND WASHINGTON SE TO BETWEEN GALESBURG AND
MACOMB. FOG WAS WIDESPREAD NORTH OF THIS BOUNDARY AND HAS REMAINED
DENSE THROUGH THE DAY ALONG THE HIGHWAY 20 CORRIDOR. SOUTH OF THE
BOUNDARY...TEMPERATURES WERE IN THE 50S...WHILE 40S WERE FOUND TO
THE NORTH. THE PRIMARY PUSH OF ARCTIC AIR WAS STILL IN THE
PLAINS...WHERE THE MAIN COLD FRONT REACHED FROM NW MN S-SW TO THE
NEB PANHANDLE. BEHIND THIS BOUNDARY...TEMPERATURES WERE IN THE TEENS
AND 20S.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 340 PM CST TUE DEC 3 2013
THE REBOUND OF WIDESPREAD DENSE FOG IS THE INITIAL CHALLENGE...THEN
TRENDS WITH THE PASSAGE OF THE STRONG COLD FRONT THAT IS NOW LIKELY
TO PUSH THROUGH WED AFTERNOON.
THE WARM FRONT WILL TRY TO PUSH NORTH TONIGHT AS THE CO LEE LOW
MIGRATES NORTHEAST ALONG THE BOUNDARY IN KS. THE BROAD LOW LEVEL
CONVERGENT FLOW AND MOISTURE ADVECTION AS DEWPOINTS IN THE 40S OVER
MO AND IL ARE DRAWN NORTH AND NORTHWESTWARD WILL KEEP THE LOW LEVELS
SATURATED. THE HRRR AND SREF FOG PROG TOOLS ARE IN ALIGNMENT WITH
THE CURRENT AREA OF DENSE FOG AND HAVE THIS EXPANDING BACK SOUTH AND
SOUTHWEST OVERNIGHT. THIS IS ALONG THE AREA OF CURRENT CONVERGENCE
FROM S CENTRAL IA NE TO NW IL AND HAVE EXPANDED OUR DENSE FOG
ADVISORY TO COVER THESE AREAS OVERNIGHT. HAVE THIS GOING UNTIL NOON
WEDNESDAY...WHEN THE ENHANCED MIXING AHEAD OF THE FRONT SHOULD BRING
SOME IMPROVEMENT. ACROSS FAR SOUTHEAST IA...FAR NE MO AND WEST
CENTRAL IL ALONG THE I-80 CORRIDOR...FOG WILL LIKELY RETURN...BUT
THERE IS LOW CONFIDENCE AS TO WHETHER IT WILL BECOME DENSE. HAVE
THUS HELD OFF ON AN ADVISORY...BUT WILL NEED TO MONITOR CLOSELY.
OTHERWISE...THE DEVELOPING LIFT AND INCREASING DIFLUENCE IN FLOW
ALOFT WILL SUPPORT ANOTHER ROUND OF LIGHT RAIN...ESPECIALLY TOWARD
MORNING ACROSS THE NORTH AND HAVE MAINTAINED CHANCE POPS.
ELSEWHERE...WILL KEEP A MENTION OF DRIZZLE WITH THE FOG.
WEDNESDAY...LATEST MODELS CONTINUE TO TREND TOWARD THE
EARLIER...SLOWER ECMWF RUNS WITH THE TIMING OF THE FROPA. THE
GFS...NAM...ECMWF...AND GEM OFFER SIMILAR SOLUTIONS WITH THE WAVE OF
LOW PRESSURE MOVING OUT OF THE PLAINS...LIFTING THROUGH THE FORECAST
AREA WEDNESDAY AFTERNOON. THIS USHERS THE PRIMARY COLD FRONT THROUGH
THE AREA BY EARLY EVENING. HAVE TRENDED THE FORECAST TOWARD THE
SLIGHTLY SLOWER ECMWF AND CANADIAN SOLUTIONS...KEEPING THE
PRECIPITATION IN THE FORM OF RAIN WITH A POSSIBLY RAIN/SNOW MIX IN
THE FAR NW LATE. WITH THE PRIMARY WARM SECTOR SWEEPING THROUGH THE
MUCH OF THE WARM SECTOR...WE SHOULD TAP INTO THE AIRMASS OVER
EASTERN MO AND SOUTHERN IL RESULTING IN MORNING OR EARLY AFTERNOON
HIGHS FROM THE LOWER 40S NW TO NEAR 60 IN THE FAR SE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 340 PM CST TUE DEC 3 2013
WEDNESDAY NIGHT THROUGH FRIDAY...TAKING INTO ACCOUNT A TYPE OF
ENSEMBLE FRONTAL MOVEMENT OF THE 12Z MODEL RUNS AND EVEN SLOWING
THAT DOWN SOME AS DEEPENING CYCLONE WRAPS UP SOMEWHERE ACRS
SOUTHWEST INTO CENTRAL WI WED EVENING...IT SHOULD BE PUSHING EAST OF
THE DVN CWA BY 01Z-02Z THU. CONVERGENT FORCING OFF THIS PROCESS MAY
WRING OUT SOME LIGHT RAIN OR DRIZZLE ALONG AND EAST OF THE MS RVR THE
FIRST 1-2 HRS OF THE FCST PERIOD. BUT THE MAIN OVERNIGHT WX STORY
WILL BE THE INCREASING WESTERLY POST-FRONTAL SFC WINDS AND DEVELOPING
LLVL COLD CONVEYOR IN-WRAPPING FROM THE NORTHWEST. BRISK WEST WINDS
OF 15 TO 25+ MPH SHOULD COLD AIR ADVECT TEMPS INTO THE UPPER TEENS
IN THE NORTHWEST...TO THE MID 20S IN THE EAST BY THU MORNING. THE
12Z RUNS THEN SUGGEST THAT AS 1035-1040 MB HIGH DUMPS DOWN THE
NORTHWESTERN PLAINS AND TIGHT CYCLONIC GRADIENT LINGERS SOME OFF
NORTHERN GRT LKS DEEP LOW PRESSURE CENTER...WINDY CONDITIONS TO
CONTINUE THROUGH AT LEAST MIDDAY THU WITH AMBIENT TEMPS ONLY
RECOVERING 3-5 DEGREES FROM MORNING VALUES AT 12Z THU. SINGLE DIGIT
ABOVE ZERO WIND CHILLS IN THE NORTHWESTERN HALF OF THE CWA THU AM.
THE ARCTIC FRONT SURGES SOUTH AND PRODUCES TIGHTENING LLVL
BAROCLINICITY AS IT SLOWS UNDER SOUTHWESTERLIES ACRS THE DEEP
SOUTHERN PLAINS TO SOUTHEASTERN OH RVR VALLEY. ALONG AND NORTH OF
THIS THERMAL RIBBON TO BE AN AXIS FOR WINTER STORM/ICE CONDITIONS
INTO FRI AND THERE IS STILL SOME VARIANCE BETWEEN THE LATEST RUN
SOLUTIONS OF FRONTAL PLACEMENT AND STRENGTH OF A WAVE RIPPLING UP
ALONG THIS HIGHWAY. THE MAJORITY OF THE 12Z MODEL RUNS STILL KEEP
ANY OVERRUNNING SNOW OFF TO THE SOUTHEAST OF THE CWA THU THROUGH FRI
WITH JUST A MID AND HIGH LEVEL CLOUD DECK MOVING UP ACRS PORTIONS OF
THE CWA LATE IN THE DAY AND OVERNIGHT. BUT THE 12Z RUN NAM AND GEM
ARE MORE BULLISH AND FURTHER NORTH WITH THE OVERRUNNING PRECIP
SHIELD AND CLIP AT LEAST THE SOUTHEASTERN THIRD OF THE DVN CWA WITH
LIGHT SNOW THU NIGHT INTO FRI MORNING. FOR NOW WILL MAINTAIN SLIGHT
CHC POPS ACRS THE FAR SOUTH AND SOUTHEASTERN CORNER OF THE FCST
AREA. MOSTLY CLOUDY...BLUSTERY AND COLD CONDITIONS CONTINUE ON FRI
WITH HIGHS ONLY IN THE UPPER TEENS TO LOWER 20S. THE INCOMING SFC
RIDGE WILL LOOK TO UNFOLD ACRS THE UPPER MS RVR VALLEY FRI NIGHT FOR
CLEARING...SFC WIND DECREASING AND COLD CONDITIONS. MANY LOWS IN THE
SINGLE DIGITS WITH A ZERO EVEN POSSIBLE IN THE NORTHWEST.
SATURDAY AND SUNDAY...THE SFC RIDGE MAINTAINS LOCALLY LONG ENOUGH FOR
A FAIR WX BUT COLD DAY SAT WITH HIGHS IN THE TEENS TO AROUND 20 AS
L/W TROF LOOMS ACRS THE SOUTHWESTERN CONUS/GRT BSN. THE MEDIUM RANGE
SOLUTIONS THEN SUGGEST NORTHERN STREAM UPPER JET ENERGY/TROFFINESS
ACRS WESTERN INTO CENTRAL CANADA TO TRY AND PHASE WITH THIS SW
CONUS LONG WAVE. THE LATEST MODEL RUNS PROBABLY STILL TRYING TO GET A
HANDLE ON THIS PROCESS AND IT WILL BE SUBJECT TO CHANGE...BUT THE
CURRENT SIGNAL SUGGESTS AT LEAST A DECENT SIZED PIECE OF WAVE ENERGY
EJECTING OUT OF THE SOUTHERN PLAINS AND THEN SOMEWHERE UP THE OH
RVR VALLEY OR EVEN FURTHER TO THE NORTHWEST SUNDAY INTO MONDAY. WITH
COLD AIR IN PLACE...THIS COULD SPELL AN EXTENDED PERIOD OF SNOW
MOVING UP ACRS PORTIONS OR ALL OF THE DVN CWA STARING OUT LATE SAT
NIGHT IN THE SOUTHWEST...AND THEN CONTINUING THROUGH LATE SUNDAY
NIGHT OR EARLY MON MORNING. THE CURRENT MODELS INCLUDING THE 12Z RUN
GFS AND ECMWF SUGGEST THE BETTER MOISTURE TRANSPORT TO FUEL HEAVIER
PRECIP TO GET PINCHED OFF/REMAIN TO THE SOUTH AND SOUTHEAST OF THE
LOCAL FCST AREA...WITH JUST SECONDARY SNOWS OF 1-3 INCHES ACRS THE
DVN CWA BY 12Z MON...SNOW MOVING OUT JUST AFTER THAT TIME-FRAME. BUT
THE DURATION/24 HRS OF ROUNDS OF AT LEAST LIGHT TO OCCASIONAL
MODERATE SNOW AND HIGHER LSR/S SUGGEST AMOUNTS COULD ADD UP TO BE
MORE. IF THE MOISTURE CONVEYOR IS LESS IMPEDED AND THE SYSTEM PULLS
UP FURTHER TO THE NORTHWEST...THERE MAY BE THE POTENTIAL FOR A MORE
SIGNIFICANT WINTER STORM IN PORTIONS OF OR CLOSE TO THE LOCAL AREA.
A WINDOW TO WATCH FOR SURE...AND WILL HAVE TO SEE HOW ADDITIONAL
MODEL RUNS BEHAVE AND HANDLE THE PHASING PROCESS. WILL RAISE THE CHC
POPS FOR NOW FOR SUNDAY NIGHT.
NEXT MONDAY AND TUESDAY...THE LONGER RANGE SIGNALS SUGGEST THAT
AFTER WHAT KIND OF SYSTEM CAN MAKE IT THROUGH OR CLOSE TO THE AREA
SUNDAY INTO EARLY MONDAY...A VERY COLD AIRMASS THEN LOOMS ACRS
CANADA. THE FRESHLY PHASED L/W TROF WILL THEN BECOME COLD CORE AND
ACT AS AN ARCTIC CONDUIT ALLOWING A COLD DUMP DOWN THE NORTHERN
PLAINS AND UPPER MIDWEST LATER MONDAY INTO TUE. THE 12Z GFS HAS A
FRIGID H85 MB COLD POOL OF -20 TO -26C BARRELING IT/S WAY DOWN
ACRS MOST OF THE CWA BY 12Z TUE...THE 12Z ECMWF IS ADVERTISING -19 TO
-21C. EVEN WITH MIXING WINDS WHICH WILL BE BRISK IN THIS TYPE OF
CAA UNDER CYCLONIC FLOW...TEMPS BY TUE MORNING MAY GO SUB-ZERO. MAY
BE WIND CHILL ADVISORY CRITERIA ATTAINED IN PORTIONS OF THE AREA LATE
MON NIGHT AND THROUGH MIDDAY TUE. WELL AGAIN...MANY SYSTEMS AND
PHASING PROCESSES TO GO THROUGH TO GET TO THIS EXTENDED PERIOD BUT
WILL START TO TREND TEMPS DOWN. ..12..
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1135 PM CST TUE DEC 3 2013
LOW CLOUDS AND/OR FOG TO RESULT IN WIDESPREAD IFR/LIFR CONDITIONS
WITH AREAS OF VLIFR CONDITIONS IN DENSE FOG THROUGH WED AM.
A COLD FRONT WILL MOVE THROUGH THE TERMINALS WED AFTN AND PUSH
THE FOG OUT AS WINDS TURN GUSTY FROM WEST/NORTHWEST AT 15-25 KTS.
SOME SPOTTY DRIZZLE AND LIGHT RAIN CAN BE EXPECTED LATER WED AM
INTO THE AFTN. ANTICIPATE VISIBILITIES TO IMPROVE TO VFR AFTER THE
FRONTAL PASSAGE WITH CIGS GENERALLY MVFR.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...DENSE FOG ADVISORY UNTIL NOON CST WEDNESDAY FOR CLARK-SCOTLAND.
&&
$$
UPDATE...05
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...12
AVIATION...05
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1145 PM MST TUE DEC 3 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 157 PM MST TUE DEC 3 2013
AS OF 3 PM CST...2 PM MST...SKIES ACROSS THE TRI-STATE AREA RANGED
FROM PARTLY CLOUDY TO OVERCAST AS HIGH CIRRUS CONTINUES TO PASS
OVER. TEMPERATURES REACHED THE LOW TO MID 60S ACROSS THE AREA WITH
THE EXCEPTION OF SOUTHWEST NEBRASKA. A BACK DOOR COLD FRONT HAS
MOVED IN FROM THE NORTHEAST...KEEPING THINGS ACROSS THE NORTHEASTERN
THIRD OF THE FORECAST AREA COOLER. WINDS HAVE BEEN FROM THE SOUTH
AHEAD OF THE COLD FRONT AND NORTHEAST BEHIND THE BACKDOOR FRONT. THE
MAIN COLD FRONT WAS FINALLY BEGINNING TO MAKE ITS SURGE INTO
NORTHEAST COLORADO. THE FRONT WAS BLOCKED BY A STRONG LEE TROUGH
CENTERED BETWEEN DENVER AND LIMON. THIS LEE TROUGH IS NOW STARTING
TO MOVE SOUTHEAST FROM LATEST RAP MSL ANALYSIS...ALLOWING THE MAIN
COLD FRONT TO SURGE SOUTH.
FOR THIS AFTERNOON AND TONIGHT...THE STRONG ARCTIC FRONT WILL MAKE
ITS PRESENCE FELT AS IT MOVES SOUTH. TEMPERATURES DROP RAPIDLY BY
THE FRONT AS SEEN BY THE 15 TO 20 DEGREE DROPS IN ONE HOUR AT YUMA
AND AKRON COLORADO. IMMEDIATELY BEHIND THE FRONT...GUSTY NORTH WINDS
ARE EXPECTED. WINDS NEAR WIND ADVISORY CRITERIA HAVE NOT BEEN
OBSERVED AND MODELS HAVE BACKED OFF ON WIND SPEEDS FROM YESTERDAYS
RUNS. THERE COULD BE SOME GUSTS THAT APPROACH WIND ADVISORY CRITERIA
BUT THIS SHOULD NOT BE WIDESPREAD NOR PERSISTENT. LOW TEMPERATURES
TONIGHT SHOULD BE ABLE TO DROP INTO THE LOW 10S TO LOW 20S EVEN WITH
DENSE CLOUD COVER. FOR PRECIPITATION CHANCES...MOST OF THE
PRECIPITATION WILL LIKELY HOLD OFF UNTIL AFTER 00Z WITH CHANCES
GRADUALLY INCREASING THROUGHOUT THE NIGHT. MODELS INDICATE THAT THE
ATMOSPHERE GRADUALLY SATURATES THROUGH THE NIGHT...ALLOWING SNOW TO
BEGIN FALLING THIS EVENING OR EARLY TOMORROW MORNING. SOUTHEAST
PORTIONS OF THE FORECAST AREA SHOULD MISS OUT ON THE PRECIPITATION
FOR THE MOST PART BUT COULD SEEM SOME FLURRIES. ACCUMULATIONS WILL
BE LIGHT AS ALL MODELS SHOW LIGHT QPF WITH HEAVIER AMOUNTS WEST
WHERE TERRAIN EFFECTS AND LIFT ARE STRONGER.
FOR TOMORROW...COLD WEATHER WILL CONTINUE WITH HIGH TEMPERATURES LESS
THAN 10 DEGREES WARMER THAN LOW TEMPERATURES TONIGHT. HIGHS ARE ONLY
ADVERTISED TO BE IN THE LOW 10S OVER NORTHEAST COLORADO TO THE MID
20S OUT NEAR HILL CITY. THIS COULD BE GENEROUS CONSIDERING THAT
DENSE CLOUD COVER AND NORTH WINDS SHOULD PERSIST. CHANCES FOR LIGHT
SNOW CONTINUE IN THE MORNING HOURS BEFORE CHANCES DECREASE ACROSS
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. CHANCES SHOULD CONTINUE
OVER EAST COLORADO WITH A SLIGHT UPSLOPE COMPONENT AND A BETTER
ATMOSPHERIC MOISTURE PROFILE. AGAIN...ONLY LIGHT ACCUMULATIONS ARE
EXPECTED WITH LITTLE IMPACT TO TRAVEL. ANOTHER THING TO NOTE ABOUT
TOMORROW IS THAT WITH THE NORTH WINDS AND COLD TEMPERATURES...WIND
CHILLS SHOULD REMAIN IN THE SINGLE DIGITS ABOVE ZERO THROUGHOUT THE
DAY WITH BELOW ZERO WIND CHILLS POSSIBLE IN EAST COLORADO. NEEDLESS
TO SAY...TOMORROW WILL BE MUCH COLDER WITH HIGH TEMPERATURES ON THE
ORDER OF 20 TO 45 DEGREES COOLER DEPENDING ON THE LOCATION.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 1139 PM MST TUE DEC 3 2013
ARCTIC AIR WILL BE FIRMLY ENTRENCHED THROUGHOUT THE LONG TERM
PERIOD WITH TEMPERATURES MUCH BELOW NORMAL. BEST CHANCES FOR
PRECIPITATION WILL BE IN THE SATURDAY NIGHT AND SUNDAY PERIOD
WITH A SHORTWAVE TROUGH EJECTING ACROSS THE CENTRAL ROCKIES.
MODELS INDICATE 1 TO 3 INCHES OF LIGHT SNOW POSSIBLE...HIGHEST
AMOUNTS IN THE SOUTHWEST PORTION OF THE FORECAST AREA. THERE ARE
HINTS THAT TEMPERATURES WILL BEGIN TO MODERATE TOWARDS THE END OF
THE PERIOD AS THE UPPER FLOW BECOMES MORE ZONAL AND THE LARGE
TROUGH WHICH WAS RESPONSIBLE FOR THE ARCTIC OUTBREAK LIFTS OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 941 PM MST TUE DEC 3 2013
MVFR CIGS CONTINUE AT KGLD AND KMCK AS HIGH PRESSURE BUILDS SOUTH
INTO THE CENTRAL PLAINS BEHIND THE COLD FRONT. METARS INDICATE
LIGHT SNOW OVER THE SOUTHERN NEBRASKA PANHANDLE. THE NAM MODEL
SHOWS SOME LIGHT SNOW POSSIBLE IN KGLD OVERNIGHT BUT THE FORECAST
SOUNDING DOES NOT SUPPORT SNOW UNTIL LATE WEDNESDAY AFTERNOON AND
EARLY EVENING. KMCK HAS EVEN LESS CHANCE FOR SNOW. DYNAMICS SHIFT
SOUTH WEDNESDAY EVENING WITH SOUNDING SHOWING IMPROVING CIGS TO
VFR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...024
AVIATION...FS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1212 AM CST Wed Dec 4 2013
...Updated aviation discussion...
.SYNOPSIS...
ISSUED AT 1106 AM CST TUE DEC 3 2013
At 12z Tuesday a -35c 500mb low was located over Idaho/western
Montana. A +100kt 300mb jet streak was located in the based of
this upper low and extended from northern Nevada into southern
Wyoming. 700 mb level difluent flow appears to be located across
eastern Wyoming. This was located near the left exit region of
the 300mb jet. Across the Central Plains earlier this morning the
850mb temperatures ranged from +10C at North Platte to +15c at
Amarillo. Dodge City this morning had a 850mb temperature of +13c.
A surface cold front was located across Nebraska at 12z Tuesday.
North of this surface cold front low clouds, gusty north winds and
light snow/fog were observed from the surface observations across
eastern Wyoming and northwest Nebraska. Surface temperatures under
the status were mainly in the 20s. 850mb temperatures north of
this front varied from -9c at South Dakota to -13c at Glasgow MT.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 222 PM CST TUE DEC 3 2013
12z NAM and GFS along with the latest HRRR and RAP were all in
decent agreement with a cold front surging south across western
Kansas during the overnight hours. Based on 18z verification
between the models and the surface observations the 2m
temperatures across Nebraska from NAM and HRRR were within 3
degrees of the actual temperature, and both of these models were
close with the surface front location. 12z NAM model soundings
across Nebraska also appeared to be picking up on the status
behind this front as well. As a result will stay close to the NAM
and HRRR on timing of the wind shift overnight along with the
magnitude of the cold air advection that will be developing behind
this front overnight as low clouds thicken across western Kansas.
Given the current temperatures behind this front in northern
Nebraska, status and cold air advection that is forecast to spread
into western Kansas later tonight have decided to stay close the
previous forecast which was also similar to the latest MET
guidance. Gusty north winds at 20 to 30 mph are also expected to
develop for several hours behind this front later tonight based
given the tight surface pressure gradient and 925-850mb winds of
25 to 35 knots. These gusty winds by daybreak will easily result
in wind chill values in the single digits by early Wednesday
morning. Isentropic lift/warm air advection along with a deepening
moist layer across portions of north central Kansas approaches a
depth favorable for some very light precipitation, however at
this time have decided not to introduce any type of very light
precipitation east of 183.
On Wednesday the status will slowly erode during the afternoon
and cold air advection continues in the 900mb to 850mb layer. Based
on the 18z Wednesday and 00z Thursday 850mb temperatures from the
NAM and GFS will undercut the MET/MAV guidance for highs.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 132 PM CST TUE DEC 3 2013
Wednesday night/Thursday:
The 12Z ECMWF, NAM, and GEM were indicating the potential for
some snow Wednesday night but mainly into Thursday as an 145 kt
250 mb jet streak moves across the region. This will create an
ageostrophic response (i.e. acceleration) and cause some synoptic
lift across the forecast area of responsibility. On top of that,
the models indicate low level isentropic lift on top of the cold
airmass. The GFS is the oddball out and was ignored as it did not
match ensemble mean nor the aforementioned consensus in the
deterministic runs. Will have to watch for a sneaky snow advisory
snow amount being met. One fly in the ointment is that the low
levels are very dry (as expected with an Arctic intrusion), so
this could reduce probabilities for more significant precipitation
measurement. Of course, not ready to buy into the thermodynamic
profiles (particularly the NAM) this far out, but did trend with
higher pops, qpf, and lower temperatures. If a snow pack does come
into fruition, the minimums into Friday morning will have to be
watched as they could bottom into negative territory. Otherwise,
midweek will be cold and have gone with bias corrected mos
guidance.
Friday and beyond:
Friday through Saturday will feature a precipitation free forecast as
the region will be between synoptic systems. The next chance of precipitation
in the form of snow will be on Sunday as another trof digs across the
central Rockies and eventually ejects out across the prairies. It is
too early to hammer out details this far out and have stuck with the
weighted blend solution. Temperatures will continue to remain below
normal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1211 AM CST WED DEC 4 2013
IFR/LIFR ceilings along with gusty north winds will prevail at the taf
sites through the remainder of tonight. MVFR visibilities will
also occur through the first part of the taf period but this
should improve to VFR between 09z-12z as drier air moves in from
the north. Look for ceilings to improve into MVFR and possibly VFR
categories between 15z-18z Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 28 10 13 5 / 0 10 50 50
GCK 26 11 12 2 / 0 30 50 50
EHA 29 7 13 1 / 10 30 50 50
LBL 29 13 13 5 / 0 10 50 50
HYS 28 9 17 5 / 0 20 10 30
P28 35 14 19 10 / 0 10 20 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burgert
LONG TERM...Sugden
AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1025 PM MST TUE DEC 3 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 157 PM MST TUE DEC 3 2013
AS OF 3 PM CST...2 PM MST...SKIES ACROSS THE TRI-STATE AREA RANGED
FROM PARTLY CLOUDY TO OVERCAST AS HIGH CIRRUS CONTINUES TO PASS
OVER. TEMPERATURES REACHED THE LOW TO MID 60S ACROSS THE AREA WITH
THE EXCEPTION OF SOUTHWEST NEBRASKA. A BACK DOOR COLD FRONT HAS
MOVED IN FROM THE NORTHEAST...KEEPING THINGS ACROSS THE NORTHEASTERN
THIRD OF THE FORECAST AREA COOLER. WINDS HAVE BEEN FROM THE SOUTH
AHEAD OF THE COLD FRONT AND NORTHEAST BEHIND THE BACKDOOR FRONT. THE
MAIN COLD FRONT WAS FINALLY BEGINNING TO MAKE ITS SURGE INTO
NORTHEAST COLORADO. THE FRONT WAS BLOCKED BY A STRONG LEE TROUGH
CENTERED BETWEEN DENVER AND LIMON. THIS LEE TROUGH IS NOW STARTING
TO MOVE SOUTHEAST FROM LATEST RAP MSL ANALYSIS...ALLOWING THE MAIN
COLD FRONT TO SURGE SOUTH.
FOR THIS AFTERNOON AND TONIGHT...THE STRONG ARCTIC FRONT WILL MAKE
ITS PRESENCE FELT AS IT MOVES SOUTH. TEMPERATURES DROP RAPIDLY BY
THE FRONT AS SEEN BY THE 15 TO 20 DEGREE DROPS IN ONE HOUR AT YUMA
AND AKRON COLORADO. IMMEDIATELY BEHIND THE FRONT...GUSTY NORTH WINDS
ARE EXPECTED. WINDS NEAR WIND ADVISORY CRITERIA HAVE NOT BEEN
OBSERVED AND MODELS HAVE BACKED OFF ON WIND SPEEDS FROM YESTERDAYS
RUNS. THERE COULD BE SOME GUSTS THAT APPROACH WIND ADVISORY CRITERIA
BUT THIS SHOULD NOT BE WIDESPREAD NOR PERSISTENT. LOW TEMPERATURES
TONIGHT SHOULD BE ABLE TO DROP INTO THE LOW 10S TO LOW 20S EVEN WITH
DENSE CLOUD COVER. FOR PRECIPITATION CHANCES...MOST OF THE
PRECIPITATION WILL LIKELY HOLD OFF UNTIL AFTER 00Z WITH CHANCES
GRADUALLY INCREASING THROUGHOUT THE NIGHT. MODELS INDICATE THAT THE
ATMOSPHERE GRADUALLY SATURATES THROUGH THE NIGHT...ALLOWING SNOW TO
BEGIN FALLING THIS EVENING OR EARLY TOMORROW MORNING. SOUTHEAST
PORTIONS OF THE FORECAST AREA SHOULD MISS OUT ON THE PRECIPITATION
FOR THE MOST PART BUT COULD SEEM SOME FLURRIES. ACCUMULATIONS WILL
BE LIGHT AS ALL MODELS SHOW LIGHT QPF WITH HEAVIER AMOUNTS WEST
WHERE TERRAIN EFFECTS AND LIFT ARE STRONGER.
FOR TOMORROW...COLD WEATHER WILL CONTINUE WITH HIGH TEMPERATURES LESS
THAN 10 DEGREES WARMER THAN LOW TEMPERATURES TONIGHT. HIGHS ARE ONLY
ADVERTISED TO BE IN THE LOW 10S OVER NORTHEAST COLORADO TO THE MID
20S OUT NEAR HILL CITY. THIS COULD BE GENEROUS CONSIDERING THAT
DENSE CLOUD COVER AND NORTH WINDS SHOULD PERSIST. CHANCES FOR LIGHT
SNOW CONTINUE IN THE MORNING HOURS BEFORE CHANCES DECREASE ACROSS
NORTHWEST KANSAS AND SOUTHWEST NEBRASKA. CHANCES SHOULD CONTINUE
OVER EAST COLORADO WITH A SLIGHT UPSLOPE COMPONENT AND A BETTER
ATMOSPHERIC MOISTURE PROFILE. AGAIN...ONLY LIGHT ACCUMULATIONS ARE
EXPECTED WITH LITTLE IMPACT TO TRAVEL. ANOTHER THING TO NOTE ABOUT
TOMORROW IS THAT WITH THE NORTH WINDS AND COLD TEMPERATURES...WIND
CHILLS SHOULD REMAIN IN THE SINGLE DIGITS ABOVE ZERO THROUGHOUT THE
DAY WITH BELOW ZERO WIND CHILLS POSSIBLE IN EAST COLORADO. NEEDLESS
TO SAY...TOMORROW WILL BE MUCH COLDER WITH HIGH TEMPERATURES ON THE
ORDER OF 20 TO 45 DEGREES COOLER DEPENDING ON THE LOCATION.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 157 PM MST TUE DEC 3 2013
COLD AIR WILL BE THOROUGHLY ENTRENCHED ACROSS THE CENTRAL HIGH
PLAINS REGION AND IS EXPECTED TO REMAIN IN PLACE THROUGH THE
FORECAST PERIOD. FLURRIES TO LIGHT SNOW WILL CONTINUE ACROSS
PORTIONS OF THE FORECAST AREA THROUGH THURSDAY NIGHT AS THE MAIN
UPPER TROUGH AND A COUPLE OF PRECEDING SHORT WAVE TROUGHS LIFT
OUT OF THE SOUTHWEST UNITED STATES AND ACROSS THE HIGH PLAINS REGION.
FRIDAY AND FRIDAY NIGHT WILL BE DRY AND COLD WITH HIGH PRESSURE IN
PLACE AT THE SURFACE IN THE WAKE OF THE UPPER TROUGH AS IT MOVES
QUICKLY TO THE EAST. LATE SATURDAY THROUGH SUNDAY BRINGS ANOTHER
CHANCE OF LIGHT SNOW AS THE NEXT UPPER LOW CENTER MOVES OUT OF THE
SOUTHWEST UNITED STATES AND INTO THE CENTRAL UNITED STATES.
MONDAY THROUGH TUESDAY WILL BE DRY AGAIN IN THE WAKE OF THE SECOND
UPPER SYSTEM WHILE COLD HIGH PRESSURE REMAINS IN PLACE...KEEPING
TEMPERATURES ABOUT 20 DEGREES COLDER THAN AVERAGE THROUGH THE
LONG TERM PORTION OF THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 941 PM MST TUE DEC 3 2013
MVFR CIGS CONTINUE AT KGLD AND KMCK AS HIGH PRESSURE BUILDS SOUTH
INTO THE CENTRAL PLAINS BEHIND THE COLD FRONT. METARS INDICATE
LIGHT SNOW OVER THE SOUTHERN NEBRASKA PANHANDLE. THE NAM MODEL
SHOWS SOME LIGHT SNOW POSSIBLE IN KGLD OVERNIGHT BUT THE FORECAST
SOUNDING DOES NOT SUPPORT SNOW UNTIL LATE WEDNESDAY AFTERNOON AND
EARLY EVENING. KMCK HAS EVEN LESS CHANCE FOR SNOW. DYNAMICS SHIFT
SOUTH WEDNESDAY EVENING WITH SOUNDING SHOWING IMPROVING CIGS TO
VFR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...LOCKHART
AVIATION...FS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
305 AM CST WED DEC 4 2013
.DISCUSSION...
LOW PRESSURE WAS LOCATED OVER NORTH CENTRAL OKLAHOMA AT 08Z
WITH A STATIONARY FRONT STRETCHING ACROSS EASTERN KANSAS INTO
CENTRAL IOWA. RADAR SHOWS PRIMARY BAND OF SNOW EXTENDS FROM NORTH
CENTRAL NEBRASKA INTO SOUTHEAST SOUTH DAKOTA AND SOUTHWEST
MINNESOTA...WHILE WIDESPREAD FOG AND DRIZZLE WAS LOCATED ALONG
THE STATIONARY FRONT. SOME LIGHT SNOW STILL LIKELY FOR NORTHEAST
BORDER AREA THIS MORNING AS SYSTEM LIFTS NORTHEAST WITH UP TO
AN INCH POSSIBLE BEFORE ENDING THIS AFTERNOON.
FREEZING DRIZZLE HAS STARTED TO BECOME MORE WIDESPREAD IN EASTERN
NEBRASKA AS THE COLDER AIR PUSHES INTO THE AREA. RAP FORECAST
SOUNDINGS SUGGEST THE POTENTIAL FOR FREEZING DRIZZLE THROUGH MOST
OF THE MORNING FOR SOUTHEAST NEBRASKA AND SOUTHWEST IOWA BEFORE
SOMEWHAT DRIER AIR WORKS INTO THE LOW LEVELS. WILL PROBABLY WAIT
UNTIL JUST BEFORE ISSUANCE TO BETTER ASSES EXTENT OF THE PRECIP
BUT ADVISORY SEEMS LIKELY AT SOME POINT.
STRONG COLD ADVECTION FINALLY ARRIVES DURING THE AFTERNOON AS AREA
COMES ON THE BACK SIDE OF THE DEPARTING SYSTEM. FOR THE REMAINDER
OF THE SHORT TERM TEMPERATURES BECOME THE PRIMARY FORECAST CONCERN
WITH VERY COLD WIND CHILLS DEVELOPING ESPECIALLY IN THE NORTH HALF
OF THE AREA.
LITTLE CHANGE IN THE EXTENDED PERIOD WITH STILL SOME CHANCE OF
SNOW LATE SATURDAY INTO SUNDAY WITH COLD TEMPERATURES CONTINUING.
&&
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
COLDER AIR WILL CONTINUE TO GRADUALLY WORK SE ACROSS TAF SITES
THROUGH WEDNESDAY. ALTHOUGH CIGS INTO MIDDAY WEDNESDAY WILL GENERALLY
BE IFR...THEY COULD OCCASIONALLY BE A BIT HIGHER. VSBYS COULD
BRIEFLY DROP BELOW 3SM AT KOMA ABSENT ANY PRECIP AS THAT LOCATION
REMAINS ON BATTLEGROUND BETWEEN SLIGHTLY DRIER MODIFIED ARCTIC
AIR OVER CNTRL NEBR AND MOISTER AIR WORKING SSW OVER IA. LATER
TONIGHT LIGHT PRECIP COULD DEVELOP AT ALL SITES WITH FREEZING
DRIZZLE POSSIBLE. EVEN A PERIOD OF SLEET IS POSSIBLE AT KOMA/KLNK
WED AM AS COLDER AIR BECOMES DEEPER...BUT PERIOD APPEARED BRIEF
AND AMOUNT/OCCURRENCE NOT QUITE HIGH ENOUGH TO INCLUDE IN TAF.
CHANCES OF A PERIOD OF LIGHT SNOW STILL APPEARED HIGH ENOUGH AT
KOFK TO INCLUDE A PERIOD OF LIGHT SNOW LATE TONIGHT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ034-
044-045-050>053-065>068-078-088>090-092.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ091-093.
IA...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ043-
055-056-069-079.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ080-090-091.
&&
$$
FOBERT/CHERMOK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1117 PM CST TUE DEC 3 2013
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
COLDER AIR WILL CONTINUE TO GRADUALLY WORK SE ACROSS TAF SITES
THROUGH WEDNESDAY. ALTHOUGH CIGS INTO MIDDAY WEDNESDAY WILL GENERALLY
BE IFR...THEY COULD OCCASIONALLY BE A BIT HIGHER. VSBYS COULD
BRIEFLY DROP BELOW 3SM AT KOMA ABSENT ANY PRECIP AS THAT LOCATION
REMAINS ON BATTLEGROUND BETWEEN SLIGHTLY DRIER MODIFIED ARCTIC
AIR OVER CNTRL NEBR AND MOISTER AIR WORKING SSW OVER IA. LATER
TONIGHT LIGHT PRECIP COULD DEVELOP AT ALL SITES WITH FREEZING
DRIZZLE POSSIBLE. EVEN A PERIOD OF SLEET IS POSSIBLE AT KOMA/KLNK
WED AM AS COLDER AIR BECOMES DEEPER...BUT PERIOD APPEARED BRIEF
AND AMOUNT/OCCURRENCE NOT QUITE HIGH ENOUGH TO INCLUDE IN TAF.
CHANCES OF A PERIOD OF LIGHT SNOW STILL APPEARED HIGH ENOUGH AT
KOFK TO INCLUDE A PERIOD OF LIGHT SNOW LATE TONIGHT.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 916 PM CST TUE DEC 3 2013/
UPDATE...
MADE SOME MINOR TEMPERATURE ADJUSTMENTS UPWARD SOUTHEAST 1/2 OR SO
TNGT AND ALSO REDUCED PRECIP CHANCES NORTHEAST THIS EVENING.
DISCUSSION...
COLD AIR IS HAVING MORE SUCCESS DROPPING SOUTH THAN SOUTHEAST AND
COLDEST TONIGHT WILL PROBABLY STAY TO OUR N THROUGH WEST. THUS
BUMPED UP MIN TEMPS A FEW DEGREES FAR E AND SE. ALSO FIRST BATCH
OF RADAR RETURNS HAVE ENDED OVER NERN NEBR AND SHORT TERM MODELS
SUGGEST MEASURABLE MAY NOT RETURN UNTIL LATE TONIGHT/EARLY
WEDNESDAY. THUS REDUCED POPS NERN ZONES THIS EVENING BUT
INCREASED LATER TONIGHT. LATEST RAP SOUNDINGS STILL SUGGEST SOME
FREEZING DRIZZLE POSSIBLE LATE TONIGHT/EARLY WEDNESDAY TOWARD LNK
AND OMAHA...AND AS COLD AIR DEEPENS...IF PRECIP CONTINUES...SOME
SLEET/SNOW PELLETS POSSIBLE AS WELL. JUST LEFT PATCHY FREEZING
DRIZZLE MENTION FOR NOW AS MEASURABLE DID NOT APPEAR TOO LIKELY
YET.
CHERMOK
PREV DISCUSSION... /ISSUED 335 PM CST TUE DEC 3 2013/
DISCUSSION...
LATEST OBJECTIVE SURFACE ANALYSIS DEPICTS LOW PRESSURE OVER THE
OKLAHOMA PANHANDLE....SPECIFICALLY JUST EAST OF COLORADO SPRINGS
AS OF 21Z. LATEST MODEL GUIDANCE TRANSLATES THIS FEATURE ALONG
THE KANSAS/OKLAHOMA BORDER OVERNIGHT AND THEN TO EASTERN IOWA BY
WEDNESDAY AFTERNOON. THIS RESULTS IN COLD AIR DROPPING ACROSS
THE CENTRAL PLAINS FOR THE NEXT SEVERAL DAYS. AS THIS COLD AIR
DIPS SOUTH...MID LEVEL FORCING CO-LOCATED WITH AVAILABLE MOISTURE
WILL GENERATE ACCUMULATING SNOW OVER PORTIONS OF
KNOX/CEDAR/ANTELOPE/PIERCE COUNTIES OVERNIGHT. BASED ON THE LATEST
INFORMATION...THE BETTER FORCING AND HIGHER ACCUMULATIONS ARE
LIKELY TO VERIFY ACROSS SOUTHEAST SOUTH DAKOTA. GIVEN THE EXPECTED
MOISTURE TRACK DECIDED TO UP SNOW AMOUNTS A BIT FOR NORTHEAST
NEBRASKA...WITH 1-3 INCHES OF SNOW EXPECTED ACROSS KNOX
COUNTY...AND A HALF INCH TO 1 INCH ELSEWHERE ACROSS NORTHEAST
NEBRASKA. AS THE BOUNDARY LAYER TRANSITIONS BELOW FREEZING SOME
ICE PELLETS/SLEET ARE ALSO POSSIBLE AS HAS BEEN ALREADY REPORTED
AT WAYNE. OPTED TO REMOVE ANY MENTION OF FREEZING RAIN AS
PROFILES SUGGEST ITS UNLIKELY TO OCCUR. FURTHER SOUTH LOW LEVEL
MOISTURE PROFILES ARE MEAGER AND SOUTHEAST OF THE PREVIOUSLY
MENTIONED COUNTIES IT APPEARS FREEZING DRIZZLE IS MORE LIKELY
GIVEN THE LACK OF APPRECIABLE FORCING AND ICE IN THE CLOUD. THIS
FREEZING DRIZZLE COULD LINGER THROUGH RUSH HOUR AND POSSIBLY LATER
IN THE MORNING. BY AFTERNOON THE LOW LEVELS SHOULD DRY OUT ENOUGH
TO END ANY DRIZZLE CONCERNS.
BEYOND WEDNESDAY NIGHT QUIET WEATHER LOOKS TO BE THE RULE THOUGH
VERY COLD AIR WILL REMAIN IN PLACE. DAYTIME HIGHS WILL STRUGGLE TO
GET OUT THE TEENS AND OVERNIGHT LOWS WILL FLIRT WITH ZERO EACH
NIGHT. BY FRIDAY GUIDANCE IS HINTING AT A WINTER STORM OVER
KANSAS AND MISSOURI...FOR NOW THIS LOOKS TO STAY SOUTH OF
NEBRASKA AND IOWA.
PEARSON
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
A BROAD UPPER TROUGH WILL KEEP THE REGION COLD THROUGHOUT THE
EXTENDED PERIOD. SOUTHWESTERLY FLOW ALOFT WILL SEND A SERIES OF
LITTLE IMPULSES TO THE AREA AND WILL PROVIDE A SMALL CHANCE FOR
LIGHT SNOW SATURDAY NIGHT INTO SUNDAY MORNING. MOISTURE IS
LIMITED...SO NOT EXPECTING MORE THAN AN INCH OR SO DURING THIS TIME.
BETTER FORCING COMES INTO PLAY SUNDAY INTO SUNDAY NIGHT AS FORCING
FROM A STRONG SHORTWAVE TROUGH MOVES NORTHEAST OUT OF COLORADO. IN
ADDITION...THE LEFT FRONT QUAD OF A 150KT 300 MB JET WILL BE PASSING
OVERHEAD PROVIDING STRONG UPPER DIVERGENCE. WE CURRENTLY HAVE CHANCE
POPS GOING AND THAT MAY NEED TO BE BUMPED UP WITH LATER FORECAST IF
THE FORCING IS STILL LOOKING STRONG. A VERY STRONG COLD PUSH WILL
SINK INTO THE REGION MONDAY NIGHT INTO TUESDAY MORNING WITH PROGGED
850MB TEMPS ANYWHERE FROM -20C TO -25C.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TULSA OK
1137 PM CST TUE DEC 3 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
HIGHLY VARIABLE FLIGHT CONDITIONS WILL BE SEEN OVERNIGHT INTO
EARLY WEDNESDAY MORNING DUE TO PATCHY FOG. MOST LOCATIONS WILL
LIKELY SEE AT LEAST OCCASIONAL PERIODS OF MVFR OR LOWER
VISIBILITIES...WITH KBVO AND KFSM MOST LIKELY TO SEE PROLONGED
PERIODS OF IFR/LIFR CONDITIONS. FOG WILL LIFT AND ALL LOCATIONS
WILL BECOME VFR BY LATE MORNING WEDNESDAY...WITH KFSM LIKELY BEING
THE LAST TO IMPROVE. WINDS WILL SHIFT TO THE NORTHWEST WEDNESDAY
AS A COLD FRONT MOVES ACROSS THE AREA.
&&
.PREV DISCUSSION... /ISSUED 859 PM CST TUE DEC 3 2013/
..UPDATE...
DISCUSSION...
PATCHY DENSE FOG IS BEGINNING TO DEVELOP ACROSS EASTERN OKLAHOMA
AND WESTERN ARKANSAS AS EXPECTED. THE CURRENT FORECAST REMAINS ON
TRACK AND WILL NOT BE UPDATED THIS EVENING.
PREV DISCUSSION... /ISSUED 535 PM CST TUE DEC 3 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOG IS ONCE AGAIN THE MAIN CONCERN TONIGHT. IT IS LIKELY THAT ALL
SITES WILL SEE IFR TO LIFR VISIBILITIES AGAIN IN FOG OVERNIGHT
INTO EARLY WEDNESDAY MORNING. VEERING SURFACE WINDS JUST AHEAD OF
A COLD FRONT WILL HELP SCOUR OUT THE FOG WEDNESDAY MORNING...WITH
VFR CONDITIONS AT ALL SITES BY MIDDAY. WINDS WILL SHIFT TO THE
NORTHWEST AT THE EASTERN OKLAHOMA SITES BEHIND THE COLD FRONT
WEDNESDAY.
PREV DISCUSSION... /ISSUED 352 PM CST TUE DEC 3 2013/
DISCUSSION...
WOW FOLKS...WHAT A FORECAST TODAY. THERE WILL BE SEVERAL ROUNDS OF
WINTRY PRECIPITATION THAT WILL HAVE IMPACTS ON TRAVEL AND POSSIBLY
THE POWER GRID AS WELL. I WILL DIVE INTO EACH FACET OF THE
FORECAST BELOW...ONE BY ONE.
FIRST...OF SOMEWHAT LESS IMPORTANCE...WILL BE FOG POTENTIAL
TONIGHT. FOR THE PAST 2 DAYS WE`VE HAD WIDESPREAD DENSE FOG.
TONIGHT...WHAT I SEE THAT IS DIFFERENT WILL BE THE DEPTH OF THE
NEAR GROUND MOIST LAYER. MODEL MOISTURE PROFILES DRY OUT FROM TOP
TO BOTTOM WITH TIME TONIGHT...ALTHOUGH THERE MAY BE ENOUGH REMNANT
MOISTURE NEAR THE GROUND FOR SOME PATCHY FOG DEVELOPMENT...SOME
POSSIBLY DENSE. FWIW...THE HRRR BREAKS OUT DENSE FOG OVER A GOOD
PORTION OF EASTERN OK THIS EVENING...AND IT HAS BEEN HANDLING THE
FOG WELL THE PAST 2 NIGHTS.
NOW TO THE MEAT OF THIS FORECAST. A VERY AMPLIFIED UPPER PATTERN
IS EVOLVING OVER THE WESTERN CONUS AS I TYPE...WITH A RIDGE NOSING
WELL UP INTO ALASKA...AND A DEEP POSITIVE TILT DOWNSTREAM TROUGH
DEVELOPING OVER THE WESTERN CONUS. THIS HAS CREATED A CROSS-POLAR
FLOW CLEAR FROM SIBERIA DOWN INTO NORTH AMERICA. WORSE YET...THIS
PATTERN WILL LIKELY PERSIST FOR ABOUT A WEEK...SENDING SHOT AFTER
SHOT OF ARCTIC AIR DOWN INTO THE CONUS AS DISTURBANCES ROTATE
AROUND THE POLAR VORTEX OVER CENTRAL CANADA. THE INITIAL SURGE OF
ARCTIC AIR WILL ARRIVE TOMORROW...AND WILL UNDERCUT A STRONG BELT
OF SW FLOW ALOFT DOWNSTREAM FROM THE WESTERN TROUGH. THE FIRST
ROUND OF PRECIP WILL BE FORCED MAINLY BY LOW TO MID LVL
FRONTOGENESIS...WHICH WILL KICK IN BY EARLY THURSDAY. THE MODELS
ARE IN VERY GOOD AGREEMENT ON A RATHER IMPRESSIVE BAND OF PRECIP
FROM SE OK UP INTO NRN AR ON THURSDAY. NE OK WILL BE ON THE FRINGE
OF THE BEST FN FORCING...AND WILL SEE LIGHTER PRECIP AMOUNTS AS A
RESULT. IN FACT...PORTIONS OF OSAGE COUNTY MAY NOT SEE ANYTHING
WITH THIS FIRST ROUND. NAM/GFS TEMP PROFILES SUGGEST THAT A BAND
OF SIGNIFICANT ICING IS POSSIBLE FROM SE OK UP INTO W CNTRL AR AND
PORTIONS OF NW AR. SOME PLACES HERE MAY PICK UP A QUARTER INCH OR
MORE OF ICE ACCUMULATION...WHICH COULD CAUSE POWER OUTAGES AND
SIGNIFICANT TRAVEL ISSUES. A BAND OF SIGNIFICANT SLEET
ACCUMULATION IS POSSIBLE JUST NORTH OF WHERE THE ZR/IP LINE SETS
UP...MOST LIKELY FROM E CNTRL AND EVENTUALLY PORTIONS OF SE OK
INTO W CNTRL AND NW AR AS THE COLDER AIR GETS DEEPER WITH TIME
FROM NORTH TO SOUTH. THIS COULD CAUSE SIGNIFICANT TRAVEL ISSUES AS
WELL. SOME LIGHT SNOW ACCUMULATION IS MOST LIKELY NEAR THE KANSAS
BORDER. THE FN FORCING SHIFTS SOUTHEAST BY THURSDAY EVENING AND
WEAKENS OVER OUR AREA...ENDING THE FIRST ROUND OF PRECIP.
ROUND TWO BEGINS LATE THURSDAY NIGHT INTO FRIDAY...AS A SHORTWAVE
TROUGH EJECTS EAST FROM THE WESTERN TROUGH OVER THE PLAINS. THE
INCREASING QG FORCING WILL BE MORE BROAD AND WILL COVER MORE OF
THE FORECAST AREA THIS GO AROUND. MODELS SUGGEST THAT A NICE WSW-
ENE ORIENTED DEFORMATION ZONE WILL SET UP FROM SOUTH CENTRAL INTO
NORTHEAST OK AND NORTHWEST AR. LAYER TEMP PROFILES FORECAST BY THE
GFS/ECMWF SUGGEST SNOW OR SNOW/SLEET FOR NE OK AND NW AR...WITH
MORE SLEET ACROSS MUCH OF SE OK AND W CNTRL AR. BASED ON QPF...THIS
COULD LEAD TO SEVERAL INCHES OF SNOW/SLEET ACCUMULATION.
HOWEVER...THE WARM NOSE MAY BE STRONG ENOUGH FOR MORE ZR AND THUS
ICE ACCUMULATION ACROSS FAR SE OK INTO W CNTRL AR LATE THURSDAY
NIGHT AS ROUND TWO GETS GOING. BY FRIDAY MORNING...THE WARM LAYER
IS ERODED ENOUGH FROM THE NORTH TO SHIFT THE BEST ICE POTENTIAL
SOUTH AND EAST OF THE FORECAST AREA. BOTH THE GFS/ECMWF SUGGEST
THAT THE QG FORCING WILL SHUT OFF RAPIDLY BY MIDDAY FRIDAY AS THE
WAVE SHEARS OUT AND LIFTS NORTHEAST OVER THE PLAINS. ROUND TWO
WILL LIKELY BRING MORE TRAVEL HEADACHES ACROSS A LARGER PORTION OF
THE FORECAST AREA. POWER INTERRUPTIONS EITHER MAY DEVELOP OR
CONTINUE OVER AREAS THAT HAVE RECEIVED THE MOST ICE ACCUMULATION
FROM THESE FIRST TWO ROUNDS OF PRECIP.
ROUND THREE GETS GOING OVER THE WEEKEND...AS ANOTHER SHORTWAVE
EMBEDDED WITHIN THE WESTERN CONUS LONGWAVE TROUGH EJECTS NORTHEAST
OVER THE PLAINS...AND A BIT FARTHER NORTH THAN THE PREVIOUS WAVE.
IN ADDITION...WITH THE SURFACE FRONT AND BEST MOISTURE NOW SHUNTED
WELL TO OUR SOUTH AND EAST...THERE WILL NOT BE AS MUCH MOISTURE
FOR THIS SYSTEM TO WORK WITH. INCREASING LOW/MID LVL ISENTROPIC
LIFT WILL RESULT IN AT LEAST LIGHT AMOUNTS OF PRECIPITATION
BEGINNING LATE SATURDAY AND INTO SUNDAY. MODEL SOUNDINGS ARE
FAIRLY DRY OVERALL IN THE CRUCIAL -10 TO -15C LAYER...WITH
MOISTURE MAINLY CONFINED BELOW 700MB. THIS WOULD SUGGEST THAT
PATCHY FREEZING DRIZZLE IS A POSSIBILITY AND HAS THUS BEEN ADDED
TO THE GRIDS. THERE ARE SOME HINTS OF PERIODIC MOISTENING DEEP
ENOUGH FOR ICE PRODUCTION...SO I HAVE ELECTED TO USE MULTIPLE
PRECIP TYPES IN THE GRIDS. THE GFS/ECMWF SUGGEST THAT THE WARM LAYER
WILL EXPAND NORTH INTO OUR AREA SOME DURING THIS TIME...AND THUS
ANOTHER ROUND OF MIXED PRECIP IS POSSIBLE...HOWEVER I WILL
REITERATE THAT PRECIP SHOULD REMAIN LIGHT OVERALL. THIS ROUND OF
PRECIP SHOULD END BY SUNDAY EVENING AS THE WARM CONVEYOR AND
RESULTING ISENTROPIC LIFT SHIFTS EAST OF OUR AREA.
FINALLY...BY EARLY NEXT WEEK THE GFS/ECMWF ARE IN GOOD AGREEMENT
THAT THE PERSISTENT WESTERN LONGWAVE TROUGH WILL LIFT OUT AND SHIFT
EAST OVER THE PLAINS. SOME LIFT AND LIMITED MOISTURE COULD SQUEEZE
OUT SOME LIGHT SNOW ON MONDAY. THIS SHOULD END WINTER PRECIP
CHANCES FOR THE TIME BEING...WHEW.
BOTTOM LINE...AN EXTENDED PERIOD OF VERY COLD WEATHER ALONG WITH
SEVERAL ROUNDS OF WINTRY PRECIPITATION ARE EXPECTED. TRAVEL WILL
BE AFFECTED...AND POWER DELIVERY MAY BE AS WELL IN SOME AREAS.
LOWS ON SATURDAY AND TUESDAY MORNING ARE EXPECTED TO DIP DOWN INTO
THE SINGLE DIGITS WITH WIND CHILLS BELOW ZERO OVER PORTIONS OF THE
AREA. GET READY FOLKS.
THE WINTER STORM WATCH WILL BE CONTINUED FOR THE ENTIRE FORECAST
AREA...WITH WARNINGS LIKELY TO FOLLOW EITHER TONIGHT OR WEDNESDAY.
LACY
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER STORM WATCH FROM 6 AM THURSDAY TO 6 PM FRIDAY FOR OKZ054-
OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-
OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-
OKZ071-OKZ072-OKZ073-OKZ074-OKZ075.
WINTER STORM WATCH FROM NOON THURSDAY TO 6 PM FRIDAY FOR OKZ049-
OKZ053-OKZ076.
AR...WINTER STORM WATCH FROM 6 AM THURSDAY TO 6 PM FRIDAY FOR ARZ001-
ARZ002-ARZ010-ARZ011-ARZ019.
WINTER STORM WATCH FROM NOON THURSDAY TO 6 PM FRIDAY FOR ARZ020-
ARZ029.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1113 PM CST TUE DEC 3 2013
.UPDATE...
ISSUED AT 945 PM CST TUE DEC 3 2013
MODELS CONTINUE TO HAVE DIFFICULTY WITH THE EVOLUTION OF TONIGHTS
SYSTEM. A LOT OF ENERGY DIVING SOUTHEAST INTO THE TROUGH...AND JUST HOW
MUCH AND WHEN THIS FORCING EJECTS EAST IS THE ISSUE. HRRR AND RAP
HAVE BEEN INCONSISTENT FROM RUN TO RUN AND THUS NOT OF MUCH USE WITH
THIS SYSTEM. RADAR TRENDS SHOW AN EXPANDING AREA OF MAINLY LIGHT SNOW
ALONG AND JUST SOUTH OF INTERSTATE 90...WITH AN EXPANDING AREA OF
MODERATE TO AT TIMES HEAVY SNOW IN NORTH CENTRAL NEBRASKA AND SOUTH
CENTRAL SOUTH DAKOTA. ACTIVITY SEEMS TO NOW BE EXPANDING NEAR THE 700
MB FRONT IN AN AREA OF BROAD ISENTROPIC LIFT AND INCREASING PV
ADVECTION. FRONTOGENESIS NOT AS WELL DEFINED IN LATEST MODEL
RUNS...SUGGESTING WE END UP SEEING A BIT OF A BROADER AREA OF
MODERATE SNOW. BASED ON RADAR TRENDS AND THE LATEST 0Z NAM...SEEMS
LIKE THIS AREA OF SNOW WILL TRACK A BIT NORTHWEST OF THE PREVIOUS
FORECAST...BUT NOT BY MUCH. AND BY AFTER MIDNIGHT...WOULD EXPECT THAT
LATTER AREA OF STEADY SNOW THAT IS CURRENTLY MOVING NORTHEAST...TO
BE FORCED MORE EASTERLY BY THE APPROACHING PV ANOMALY. THIS SHOULD
BRING THIS AREA OF SNOW THROUGH ALL THE COUNTIES CURRENTLY IN THE
HEADLINE. DID ADJUST POPS UPWARD IN THE MORNING TO ACCOUNT FOR THIS
SLOWER TIMING. ALSO WE STAY SATURATED THROUGH THE DAY...AND AS ONE
MORE PUSH OF LIFT MOVES ACROSS DURING THE LATE MORNING AND EARLY
AFTERNOON WE MAY VERY WELL SEE ANOTHER LITTLE BURST OF SNOW DROPPING
ANOTHER INCH OR SO...SORT OF LIKE THE 0Z NAM SHOWS.
STILL LOOKS LIKE A WIDESPREAD 3 TO 6 INCHES IN THE WARNING...WITH
ISOLATED HIGHER AMOUNTS AROUND 7 INCHES...ESPECIALLY IF RATIOS END
UP A BIT HIGHER OR IF WE DO SEE A BIT MORE ENHANCED BANDING. LATEST
TRENDS WOULD SUGGEST THE BEST CHANCE OF SEEING THESE HIGHER AMOUNTS
WILL BE FROM GREGORY TO MITCHELL TO MARHSALL...WITH AMOUNTS ON THE
LOWER SIDE OF THE RANGE AS YOU GET TO THE SOUTHEAST EDGE OF THE
WARNING. HEADLINES LOOK IN GOOD SHAPE...AND THUS NO CHANGES PLANNED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 350 PM CST TUE DEC 3 2013
RELATIVE QUIET PERIOD FROM LATE MORNING INTO EARLY AFTERNOON IS
STARTING TO CHANGE AS LIFT FORCING SPREADS INTO SOUTH CENTRAL SOUTH
DAKOTA IN ADVANCE OF STRONG JET PUNCHING OUT OF THE CENTRAL ROCKIES.
STRONG FRONTOGENETIC FORCING WILL CONTINUE TO EXPAND ENE ALONG MID
LEVEL BOUNDARY THROUGH THE EVENING...AND SHOULD LEAD TO A QUICK
DEVELOPMENT OF SNOW BAND WITH LIFT AND SNOW GROWTH WELL COLLOCATED
IN PROFILES OF MAIN BAND. SHADED TOWARD A SOMEWHAT COOLER THERMAL
PROFILE OVERALL WITH WET BULB EFFECT AND SUPPORT OF EC/SREF. EVEN
WITH THIS...SHOULD BE WARM ENOUGH ALOFT FOR SOME ALTERNATE TYPES IN
TRANSITION AT ONSET...PROBABLY SLEET AND LIGHT FREEZING RAIN BEFORE
A CHANGE TO SNOW. SOME LIGHT ICE ACCUMULATIONS MENTIONED FOR AREAS
AROUND THE IOWA GREAT LAKES...WHERE LOW LEVEL COOL PUSH WILL BE IN
PROXIMITY TO THE LINGERING WARMER AIR ALOFT.
MAIN CHANGE IN THE FORECAST FROM THE MID TO LATE MORNING UPDATE WAS
TO INTRODUCE A WINTER STORM WARNING TO AREAS GENERALLY NORTH OF A
WINDOM TO SIOUX FALLS TO WAGNER LINE. STILL LOOKING AT A BROAD
BANDING OF 4 TO 6 INCHES SNOWFALL...WITH LOCALLY HEAVIER AMOUNTS.
HARD TO PINPOINT THE EXACT LOCATION OF THE HEAVIER BAND...THE
STRONGER REASON FOR UPGRADING TO THE WARNING WAS COMBINING THE
SNOWFALL WITH GUSTY WINDS OF 25 TO 35 MPH. STRONGEST WINDS WILL
FIRST DEVELOP ACROSS THE WESTERN CWA AFTER MIDNIGHT...AND EXPAND
EASTWARD AS LOW PRESSURE INTENSIFIES TO THE SOUTHEAST LATER TONIGHT
AND WEDNESDAY. WINDS WILL BE SLOW TO INCREASE IN THE FAR EAST WITH
BAGGY GRADIENT NEAR THE INVERTED TROUGH...BUT EVENTUALLY WILL
INCREASE AND CREATE PROBLEMS WITH STRONGER GRADIENT BY LATE DAY IN
SW MN. BLOWING SNOW SHOULD REDUCE VISIBILITIES TO AROUND A HALF MILE
AT TIMES...AND COULD BE BRIEFLY LOWER AT TIMES OF FALLING SNOW.
SNOWFALL NOW LOOKING A BIT MORE APT TO CONTINUE INTO WEDNESDAY
ACROSS THE AREA...BUT WILL SLOW UP FROM SOUTHWEST TO NORTHEAST AS
INVERTED TROUGH PULLS EAST...AND UPPER WAVE WANDERS SLOWLY NORTH OF
THE AREA. TEMPERATURES WILL BE IN STRONG SUPPORT OF ICE PROCESSES
DURING THE DAY...SO PERHAPS EVEN FAVORABLE FOR FLURRIES AFTER
MEASURABLE THREAT WANES.
OTHERWISE...SOME AREAS OF DENSE FOG CONTINUE THIS AFTERNOON ACROSS
SOUTHWEST MINNESOTA...AND SO NOT TO CONFUSE WITH OVERALL WINTER
SCENARIO...HAVE NOT ISSUED A SEPARATE ADVISORY ON THIS FEATURE.
THERE WILL LIKELY BE SOME PATCHES OF FREEZING DRIZZLE INTERSPERSED
WITH FLURRIES UNTIL STRONGER FORCING AND DEEPER MOISTURE SPREADS IN
BY THE EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 PM CST TUE DEC 3 2013
ANY LIGHT SNOW WILL TAPER DOWN TO FLURRIES ON WEDNESDAY NIGHT AS THE
SYSTEM PULLS AWAY AND FORCING IS LOST. CONFINED ANY BLOWING SNOW IN
THE EVENING TO AREAS WHICH COULD ACTUALLY RECEIVE AT LEAST A TENTH
OF AN INCH OF SNOW...THOUGH WINDS WILL ONLY MARGINALLY DIMINISH
OVERNIGHT WITH A TIGHT GRADIENT REMAINING ACROSS THE REGION...SO
COULD SEE PATCHY BLOWING SNOW OVER OTHER AREAS. EVEN WITH COLD AIR
ADVECTION CONTINUING...TEMPERATURES WILL REMAIN SOMEWHAT IN CHECK ON
WEDNESDAY NIGHT WITH ABUNDANT CLOUD COVER AND THE ABOVE MENTIONED
WINDS...THOUGH READINGS WILL STILL DROP TO AROUND ZERO BY VERY EARLY
THURSDAY MORNING. WIND CHILLS OVERNIGHT WILL JUST MEET WIND CHILL
CRITERIA IN SOME AREAS...AND MAY HAVE TO DEAL WITH THAT AT SOME
POINT IN REGARD TO HEADLINES...BUT WITH THE CURRENT HEADLINES OUT
DID NOT WANT TO CONFUSE THE MATTER.
SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION ON
THURSDAY...AND IT WILL REMAIN BREEZY IN A COLD AIR ADVECTION
REGIME...ALTHOUGH WINDS WILL SLOWLY TAPERING DOWN DURING THE DAY AS
THE GRADIENT RELAXES A BIT. NOT SURE HOW QUICKLY CLOUDS WILL
DECREASE DURING THE DAY...WITH BOTH THE NAM AND GFS HINTING AT
STRATUS LINGERING THROUGH THE DAY. IN LIGHT OF THAT AND WITH SNOW
COVER ACROSS THE AREA WENT ON THE LOW SIDE OF GUIDANCE WITH HIGHS
ONLY IN THE SINGLE DIGITS AND TEENS. BY THURSDAY NIGHT IT DOES LOOK
LIKE THERE SHOULD BE MORE CLEARING...THOUGH WINDS WILL NOT
COMPLETELY DROP OFF...REMAINING CLOSE TO 10 KTS. BECAUSE OF
THAT...AGAIN THINK THAT TEMPERATURES WILL NOT COMPLETELY BOTTOM
OUT...THOUGH WENT ON THE LOW SIDE OF GUIDANCE WITH LOWS FROM NEAR 10
BELOW IN THE NORTH TO NEAR ZERO IN THE FAR SOUTHEAST. IF WINDS WOULD
BECOME CALM THEN IT WILL BE COLDER THAN CURRENTLY FORECASTED.
BY FRIDAY...925 MB TEMPERATURES ARE PROGGED TO BE WELL INTO THE
NEGATIVE UPPER TEENS TO NEGATIVE LOWER 20S C...AND WENT BELOW
GUIDANCE WITH HIGHS IN THE SINGLE DIGITS. FRIDAY NIGHT IS SETTING UP
TO BE THE COLDEST NIGHT OF THE NEXT FEW AS THE HIGH PRESSURE AXIS
MOVES OVERHEAD AND WINDS BECOME NEARLY CALM. THE ONLY FLY IN THE
OINTMENT WILL BE THE POSSIBILITY OF INCREASING MID AND HIGH
CLOUDS...BUT WENT BELOW ALL BLEND GUIDANCE...AND AM STILL PROBABLY
TOO WARM AS MODEL RUNS ARE COLDER. AT THIS POINT...HAVE LOWS IN THE
MID TEENS BELOW ZERO TO THE SINGLE DIGITS BELOW.
IN THE EXTENDED...SATURDAY THROUGH TUESDAY...THE COLD AIR LOOKS TO
BE LOCKED IN THROUGH THE PERIOD. MODELS IN FAIRLY DECENT AGREEMENT
ON BRINGING A CHANCE OF SNOW TO THE AREA SOMETIME IN THE SUNDAY TIME
FRAME...AS A NORTHERN STREAM UPPER LEVEL TROUGH BEGINS TO DROP INTO
THE NORTHERN PLAINS AND A SOUTHERN STREAM WAVE EJECTS OUT OF THE
DESERT SOUTHWEST. A REINFORCING SHOT OF COLD AIR DROPS INTO THE
REGION FOR THE BEGINNING OF NEXT WEEK WITH THE PASSAGE OF THIS
SYSTEM...AND MODELS HINTING THAT IT COULD BE EVEN COLDER THAN THE
UPCOMING COLD SPELL...THOUGH WILL HAVE TO WATCH AS IT IS STILL
PRETTY FAR OUT. IN ANY EVENT...STAYED ON THE LOW SIDE OF GUIDANCE
THROUGH THE PERIOD WITH EXPECTED SNOW COVER. THIS WILL PLAY OUT TO
HIGHS SINGLE DIGITS AND TEENS AND LOWS A FEW DEGREES EITHER SIDE OF
ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1113 PM CST TUE DEC 3 2013
BAND OF HEAVIER SNOW SLATED TO MOVE ACROSS NORTHWEST HALF OF THE
FORECAST AREA THROUGH EARLY-MID MORNING WEDNESDAY...MAINLY IN AREAS
NEAR/NORTH OF A LINE FROM WAGNER-SIOUX FALLS-WINDOM. VISIBILITY OF A
MILE OR LESS WILL BE DOMINANT IN THE HEAVIER SNOW BAND...WITH IFR TO
OCCASIONALLY MVFR VISIBILITY...ALONG WITH IFR-MVFR CEILINGS EXPECTED
ELSEWHERE THROUGH THE NIGHT. SPOTTY FREEZING RAIN/DRIZZLE WILL ALSO
BE POSSIBLE IN THE PRE-DAWN HOURS OVER NORTHWEST IOWA. AMOUNTS WILL
BE VERY LIGHT...BUT SLIGHT ICING COULD OCCUR. IN ADDITION TO FALLING
SNOW...AREAS OF BLOWING SNOW WILL CREATE ADDITIONAL REDUCTIONS IN
VISIBILITY AS NORTH-NORTHWEST WINDS INCREASE TO 15-20KT WITH GUSTS
OF 20-30KT THROUGH THE DAY.
SNOWFALL CONDITIONS WILL IMPROVE GRADUALLY FROM SOUTHWEST TO
NORTHEAST AFTER 12Z-15Z...THOUGH EXPECT MVFR CONDITIONS AT BEST...AS
SCATTERED LIGHT SNOW AND AREAS OF BLOWING SNOW DUE TO THE STRONG
WINDS CONTINUE INTO THE EVENING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
SDZ068-069.
WINTER STORM WARNING UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
SDZ038>040-050-052>067.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
MNZ089-090.
WINTER STORM WARNING UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
MNZ071-072-080-081-097-098.
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST WEDNESDAY NIGHT FOR
IAZ001-002.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...CHAPMAN
LONG TERM...JM
AVIATION...JH
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1152 PM CST TUE DEC 3 2013
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. A COLD
FRONT MOVING SOUTH OUT OF THE PANHANDLES WILL BRING A NORTHERLY
WIND SHIFT TO KCDS THIS MORNING...WHILE SW WINDS WILL BECOME
BREEZY AT KLBB..SUSTAINED AROUND 15 TO 20 KTS. WINDS WILL DIMINISH
THIS EVENING WHILE A STRONGER FROPA APPROACHES TOWARD THE END OF
THE FORECAST. CLOUD COVER SHOULD BE CONFINED TO HEIGHTS AOA 20K FT
THROUGH 06 UTC...ALTHOUGH LOW STRATUS MAY BE APPROACHING KCDS BY
THAT TIME.
&&
.PREV DISCUSSION... /ISSUED 955 PM CST TUE DEC 3 2013/
UPDATE...
THE COLD FRONT AT 930 PM HAD ALMOST CLEARED SE COLORADO AND WRN
KANSAS AS IT RACES TOWARD THE PANHANDLES. THIS APPEARS TO BE
A FEW HOURS FASTER THAN MODEL PROJECTIONS. THE RAP NOW HAS THE
LEADING EDGE OF THE FRONT INTO THE CHILDRESS AREA BY 11 UTC/5
AM...ABOUT 3 HOURS EARLIER THAN PREVIOUS INDICATIONS. WITH THIS IN
MIND...THE FRONT MAY MAKE BETTER PROGRESS THROUGH THE CWFA BEFORE
STALLING OUT LATE MORNING OR MIDDAY WED. IN FACT...IT IS NOT OUT OF
THE QUESTION THE WIND SHIFT COULD MAKE IT INTO THE CENTRAL SOUTH
PLAINS...ALTHOUGH ALL AVAILABLE GUIDANCE STILL SHOWS SW BREEZES
OUT-DUELING THE FRONT AND LEADING TO A WARM AFTERNOON FOR MOST OF
THE CAPROCK. THEN THE FRONT WILL BLAST THROUGH THE ENTIRE CFWA
WEDNESDAY NIGHT.
THE 00 UTC NAM AND LATEST TTU-WRF AND SREF ALL SUGGEST THAT A
SHORTWAVE APPROACHING FROM THE SW WILL ENHANCE LIFT OVER THE COLD
AIR EARLY THURS MORNING. HOWEVER...AS PREVIOUS DISCUSSION
MENTIONED...MUCH OF THE INITIAL LIFT WILL GO TO SATURATING THE
INITIALLY DRY LOWER-LEVELS AND IT IS UNCERTAIN HOW MUCH PRECIP CAN
ACTUALLY GET WRUNG OUT BEFORE THE FIRST WAVE EXITS MIDDAY. MOST MODEL
PROGS SUGGEST THE BEST PRECIP POTENTIAL WILL BE ACROSS SRN AREAS
WITH THIS FIRST BATCH OF LIFT...WITH SOUNDINGS SHOWING A WINTRY MIX
OF SLEET AND SNOW FOR THE HIGHER ELEVATIONS AND SOME FREEZING RAIN
POTENTIAL OFF THE CAPROCK. THE BETTER CHANCES OF MORE SIGNIFICANT
FROZEN ACCUMULATIONS ARE STILL EXPECTED TO DEVELOP WITH THE
ARRIVAL OF THE MAIN UPPER WAVE THURS EVENING.
A WINTER STORM WATCH CONTINUES FOR THE ENTIRE CFWA BEGINNING 6 AM THURSDAY.
PREV DISCUSSION... /ISSUED 540 PM CST TUE DEC 3 2013/
AVIATION...
VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS. A COLD FRONT
WITH A NORTHERLY WIND SHIFT IS EXPECTED TO ARRIVE AT KCDS AROUND
14 UTC. GUSTY WEST WINDS ARE EXPECTED AT KLBB DURING THE DAY...SUSTAINED
AT NEARLY 20 KTS....BEFORE SUBSIDING IN THE EVENING. CONSIDERABLE
UPPER-LEVEL CLOUDINESS WILL ALSO CONTINUE TO STREAM OVER THE AREA.
PREV DISCUSSION... /ISSUED 303 PM CST TUE DEC 3 2013/
SHORT TERM...
WEATHER PATTERN IS DOMINATED BY A HIGH AMPLITUDE RIDGE OFF THE WEST
COAST AND A STRONG LOW OVER MANITOBA...A SET-UP CONDUCIVE FOR
SHARPLY COLDER WEATHER...BUT MORE ON THAT IN THE LONG TERM. LEAD
WAVE IN A SERIES OF EMBEDDED DISTURBANCES ROTATING ABOUT
AFOREMENTIONED LOW WILL APPROACH WEDNESDAY EVENING AND WILL HELP
DRIVE INITIAL WIND SHIFT OF THE COLD-SPELL-TO-BE INTO OUR
NORTHEASTERN ZONES.
BREEZY CONDITIONS HAVE PERSISTED TODAY...PARTICULARLY ACROSS THE
NORTHERN ZONES ALONE WITH QUITE DRY LOW LEVELS LEADING TO ELEVATED
FIRE WEATHER CONDITIONS. ERC VALUES REMAIN ANEMIC ESPECIALLY WITH
THE EXTRA GROUND MOISTURE FROM THE LAST SNOW/ICE EVENT. INTO
WEDNESDAY...RH VALUES WILL BE ON THE RISE. FROM A SENSIBLE WEATHER
PERSPECTIVE...PLEASANTLY WARM CONDITIONS WILL PERSIST INTO WEDNESDAY
ALONG WITH INCREASING HIGH CLOUDINESS. THE WINDIEST
CONDITIONS...APPROACHING 20 KTS...SHOULD BE ACROSS THE SOUTHWESTERN
ZONES WELL DISPLACED FROM THE FRONTAL CONVERGENCE ZONE.
LONG TERM...
CERTAINTY IN THE FORECAST HAS INCREASED A BIT FROM THE PREVIOUS
SHIFT ALTHOUGH SOME SIGNIFICANT DIFFERENCES STILL REMAIN TO BE
NEGOTIATED AS THE EVENT DRAWS NEARER. MOIST ISENTROPIC LIFT WILL
BEGIN THURSDAY MORNING AND INCREASE THROUGH THE DAYTIME. GREATEST
LIFT WILL BE ACROSS NEW MEXICO INTO THE WESTERN PANHANDLE WHERE
THERE WILL BE AROUND 30KT OF FLOW ON THE ISENTROPIC SURFACES.
EARLY ON THURSDAY...MID AND UPPER LEVELS WILL BE MOIST AS A WEAK
SHORT WAVE MOVES OVER THE AREA OUT AHEAD OF THE MAIN TROUGH. DRY
AIR IN THE LOWER LEVELS OF THE ATMOSPHERE WILL HAVE TO BE OVERCOME
FOR SIGNIFICANT ACCUMULATIONS TO OCCUR. HOWEVER...BY THE TIME THE
ATMOSPHERE COMPLETELY SATURATES...DEEP LIFT WILL HAVE BEEN ERODED
WITH ONLY ISENTROPIC LIFT REMAINING. BY THE EVENING AS THE MAIN
TROUGH MOVES OUT OVER THE AREA...Q-VECTOR CONVERGENCE WILL BE
MAXIMIZED WITH A STRONG UPPER LEVEL JET. BY DAYBREAK ON
FRIDAY...ISENTROPIC DOWNGLIDE WILL BE RAPIDLY SWEEPING INTO THE
AREA BEHIND THE TROUGH SHUTTING DOWN PRECIPITATION.
ALTHOUGH...FRIDAY WILL LIKELY REMAIN CLOUDY WITH LOW LEVEL
MOISTURE GOING NO WHERE.
A WARM LAYER ALOFT WILL BE MOST PREVALENT NEAR THE SOUTHERN HALF
OF THE FA ADDING ANOTHER LAYER OF DIFFICULTY TO THE FORECAST. VERY
DRY SURFACE AIR MAY PREVENT MUCH PRECIPITATION OVER THE
SOUTHEASTERN TEXAS PANHANDLE EARLY IN THE EVENT ON THURSDAY. ON
THURSDAY...GENERALLY SNOW WILL BE THE PREFERRED PRECIPITATION TYPE
OVER THE SOUTHERN TEXAS PANHANDLE WITH LIGHT FREEZING PRECIPITATION
AND SLEET OVER THE SOUTH PLAINS AND ROLLING PLAINS. GIVEN THE FACT
THAT LIFT WILL ONLY BE COMING FROM ISENTROPIC LIFT...FREEZING
PRECIPITATION ACCUMULATIONS WILL LIKELY BE LIGHT. AS DEEPER LIFT
INCREASES ON THURSDAY NIGHT...THE COLUMN WILL COOL BELOW 0C FOR
MUCH OF THE AREA WITH THE EXCEPTION OF THE SOUTHERN ROLLING
PLAINS. HOWEVER...MID AND UPPER LEVEL DRY AIR WILL BE QUICKLY
WORKING INTO THE REGION FROM THE NORTHWEST ON THURSDAY EVENING. A
MOSTLY SNOW EVENT FOR THE NORTHERN AREAS DURING THURSDAY EVENING
THROUGH FRIDAY MORNING MAY TURN MORE INTO A WINTRY MIX. FREEZING
PRECIPITATION IS STILL THE LIKELY PRECIPITATION TYPE OVER THE
SOUTHERN ROLLING PLAINS. IN ADDITION TO THE WINTRY
PRECIPITATION...TEMPERATURES WILL BE VERY COLD WITH A STRONG
SURFACE RIDGE MOVING INTO THE CENTRAL US ALONG WITH STRONG
MERIDIONAL FLOW TAPING INTO ARCTIC AIR.
THE NEXT TROUGH WILL BE DIGGING INTO THE SOUTHWEST US ON SATURDAY
AND WILL GENERATE ADDITIONAL ISENTROPIC UPGLIDE ON SATURDAY. GIVEN
THE SHALLOW NATURE OF THE MOISTURE AND COLD
TEMPERATURES...FREEZING DRIZZLE APPEARS LIKELY ALTHOUGH
ACCUMULATIONS WILL BE EXTREMELY LIGHT. ANOTHER COLD BLAST MAY MAKE
ITS WAY DOWN INTO THE US AGAIN WITH THE POLAR VORTEX STILL
SPINNING OVER SOUTHERN CANADA AND NO LETTING UP ON THE STRONG
MERIDIONAL FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 38 62 20 25 10 / 0 0 10 50 60
TULIA 37 63 21 25 11 / 0 0 20 30 60
PLAINVIEW 38 66 22 26 13 / 0 0 30 30 60
LEVELLAND 42 67 28 30 16 / 0 0 30 40 60
LUBBOCK 40 69 27 29 16 / 0 0 30 50 60
DENVER CITY 43 65 34 37 17 / 0 0 20 50 60
BROWNFIELD 43 67 29 32 17 / 0 0 30 50 60
CHILDRESS 35 61 25 28 13 / 0 0 20 30 60
SPUR 41 73 26 29 14 / 0 0 30 50 60
ASPERMONT 43 76 27 30 16 / 0 0 40 50 60
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THURSDAY MORNING THROUGH FRIDAY MORNING
FOR THE FOLLOWING ZONES: TXZ021>044.
&&
$$
33
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1125 PM CST TUE DEC 3 2013
.AVIATION...
/06Z TAFS/
CONCERNS...ARRIVAL OF FRONT AT THE DFW TAF SITES TOMORROW AFTERNOON.
AN ARCTIC FRONT IS QUICKLY MAKING ITS WAY DOWN THE PLAINS AND WILL
ARRIVE IN NORTH TEXAS SEVERAL HOURS SOONER THAN PREVIOUSLY
THOUGHT. THROUGH TONIGHT...SOUTH TO SOUTHWEST WINDS BELOW 10 KTS
WILL PREVAIL. IN THE DFW AREA...THE WINDS WILL BECOME MORE
WESTERLY AROUND 16Z. THE LEADING EDGE OF THE FRONT WILL SLOWLY
AND QUIETLY SEEP THROUGH DFW AROUND 20-21Z TOMORROW AFTERNOON.
THE WINDS MAY ACTUALLY BE LIGHT AND VARIABLE FOR A FEW HOURS AS
THE FRONT STALLS NEAR THE I-20 CORRIDOR BUT NORTH WINDS SHOULD
PREVAIL BY THE EVENING HOURS. WIND SPEEDS WILL INCREASE OVERNIGHT
WITH STRONGER WINDS BETWEEN 15-20 KTS ON THURSDAY.
THE FRONT WILL NOT REACH KACT IN THIS TAF PERIOD AND EXPECT SOUTH
TO SOUTHWEST WINDS TO PREVAIL THROUGH THE PERIOD. THE FRONT WILL
ARRIVE TOMORROW NIGHT...JUST BEYOND THE TIMING OF THIS TAF PERIOD.
IN THE EXTENDED...FROZEN PRECIPITATION NOW APPEARS MORE LIKELY AT
THE DFW TAF SITES AS EARLY AS THURSDAY EVENING AND IS A
POSSIBILITY AT WACO EARLY FRIDAY MORNING.
82/JLD
&&
.UPDATE...
THE MAIN UPDATE ISSUE OF INTEREST IS THAT WE HAVE EXPANDED THE
WINTER STORM WATCH TO COVER THE NW HALF OF NORTH TEXAS. BUT FOR
TONIGHTS FORECAST HAVE LOWERED TEMPERATURES IN A FEW AREAS WHERE
DRY AIR AND GOOD RADIATIONAL COOLING ARE EXPECTED. HAVE ALSO ADDED
A MENTION OF FOG TO THE EAST AND SOUTHEAST ZONES WHERE
TEMPERATURES WILL COOL TO REACH THE DEWPOINTS.
WITHOUT EVEN LOOKING AT THE MODEL DATA THE 0Z UPPER AIR ANALYSIS
FOREBODES AN OMINOUS SETUP FOR WINTER WEATHER FOR NORTH TEXAS. THE
UPPER PATTERN SUGGESTS THAT AT SOME POINT IN THE NEXT FEW
DAYS...EITHER THURSDAY NIGHT/FRIDAY AND/OR THIS WEEKEND THE
COMBINATION OF COLD AIR AND MOISTURE/LIFT ARE GOING TO COME INTO
PLAY TO CREATE A WINTRY MIX OVER MUCH OF THE AREA.
WHILE SURFACE TEMPS ARE THE GO-TO FOR SEEING HOW COLD AN AIR MASS
IS...IT IS ACTUALLY BETTER TO ANALYZE THE LOW-MID LEVEL TEMPS
UPSTREAM TO SEE HOW COLD THE AIR IS THERE. THIS IS BECAUSE AIR
BEHIND A COLD FRONT UNDERGOES SLOW SUBSIDENCE AS IT MAKES ITS WAY
SOUTH FROM THE ARCTIC. BACKWARD TRAJECTORIES OF PAST COLD FRONTS
SHOW US TO CHECK 500-700MB TEMPS IN THE ARCTIC REGION SEVERAL DAYS
OUT...AND 700-850MB TEMPS ACROSS SOUTHERN CANADA 2 TO 3 DAYS OUT
TO GET A ROUGH IDEA ON HOW COLD IT IS GOING TO GET. THUS IT IS
CONCERNING THAT THE UPPER AIR ANALYSIS FROM 00Z REVEALS
EXCEPTIONALLY COLD AIR AT 700MB-850MB ACROSS MONTANA AND INTO
ALBERTA. GREAT FALLS MONTANA HAD A 700MB TEMP OF -24C AND -20C AT
850MB. THESE TEMPS ARE RUNNING 2 TO 3 STANDARD DEVIATIONS BELOW
NORMAL...WHICH IS AKIN TO SAYING THIS WOULD BE NEAR RECORD COLD
IF WE KEPT RECORDS AT THIS POINT IN SPACE. MODEL GUIDANCE HAS BEEN
2-4 DEG C TOO WARM WITH 6-12 HOUR FORECAST TEMPS AT THIS LEVEL AS
WELL...BUT IS BEGINNING TO CATCH ON.
MEANWHILE THE SURFACE ANALYSIS IS SHOWING THE COLD FRONT
BARRELING SOUTH THROUGH THE PLAINS...AND AHEAD OF SCHEDULE...NOW
CROSSING THROUGH MOST OF WESTERN KANSAS. ALL MODELS EXCEPT FOR THE
RAP/NAM ARE MUCH TOO SLOW IN THEIR 3-6 HOUR FORECASTS. THIS IS A
COMMON ISSUE WITH ARCTIC FRONTS WHEN THE 500MB PATTERN IS SITUATED
IN THIS FASHION. LEE SIDE COLD AIR DAMMING IN THE FRONT RANGE OF
THE ROCKIES CAUSES THE SURFACE HIGH TO BUILD FARTHER SOUTH AND
ALLOWS FOR STRONGER EQUATOR-WARD TRANSPORT OF ARCTIC AIR THAN
FORECAST. HIGH RESOLUTION MODELS DO A BETTER JOB AT FORECASTING
THIS...AND THE NAM/WRF MODELS ARE ABOUT THE BEST WE HAVE IN THE
SHORT-MEDIUM TIME RANGE. THE RAP IS EXCELLENT IN THIS SITUATION AS
WELL...BUT ONLY GOES OUT 18 HOURS. THE NAM AND RAP MODELS ARE
INDICATING THE FRONT WILL REACH THE NORTHWEST ZONES AFTER
SUNRISE...AND WILL LIKELY STALL ALONG OR JUST NORTH OF THE I-20
CORRIDOR WEDNESDAY AFTERNOON. THE AIR BEHIND THIS FRONT WILL BE
VERY SHALLOW...AND SUNSHINE WILL MODERATE THE LEADING EDGE OF THIS
AIR GREATLY. THUS HAVE BUMPED UP THE TIMING OF THE FRONT SEVERAL
HOURS AND LOWERED HIGHS INTO THE 60S IN THE NORTHERN ZONES.
WOULD NOT BE SURPRISED TO SEE THE FRONT MOVE THROUGH THE METROPLEX
IN THE AFTERNOON HOURS BUT AGAIN...THE CHANGE IN TEMPS AND WINDS
WILL NOT BE ALL THAT DRASTIC AT FIRST. THE REAL COLD AIR WILL
GRADUALLY INVADE THE REGION THROUGH THE OVERNIGHT HOURS.
THE NEW 00Z NAM HAS COME IN COLDER THURSDAY...AND ESSENTIALLY ALL
GUIDANCE BUT THE SREF IS INDICATING TEMPERATURES NEAR FREEZING
ACROSS THE NORTHWEST ZONES THURSDAY AFTERNOON AS PRECIPITATION
BEGINS TO DEVELOP. SINCE THE AIR IS SO COLD UPSTREAM IN THE SOURCE
REGION...AND THESE FRONTS TEND TO RUN A LITTLE COLDER THAN
MODEL FORECASTS...HAVE BUMPED UP THE TIMING OF THE FREEZING RAIN
AND WINTER STORM WATCH TO THURSDAY AFTERNOON OVER THE NORTHWEST
ZONES. IT IS TOO TOUGH TO SAY WHETHER IMPACTS WILL BEGIN
IMMEDIATELY THURSDAY AFTERNOON...BUT FELT THAT THE WATCH STARTING
AT 0Z WAS CUTTING IT TOO CLOSE.
AGAIN THERE IS GOOD MODEL AGREEMENT REGARDING THE FORECAST FOR
THURSDAY NIGHT AND FRIDAY. HAVE NOT CHANGED ANY OF THE FORECASTED
SENSIBLE WEATHER FROM THE PREVIOUS FORECAST AS IT ALL LOOKS
GOOD. HOWEVER...THERE MAY END UP BEING MORE SLEET THAN FREEZING
RAIN OVER THE NORTHWEST ZONES BUT IT IS TOO EARLY TO TELL FOR
SURE. HOWEVER PLACING A PERCENT LIKELIHOOD OF WINTER STORM WARNING
CRITERIA BEING MET IS TOUGH AT THIS POINT. WPC NOW INDICATES THE
DFW METROPLEX AND NORTHEAST INTO PARIS HAVE A 50-60 PERCENT CHANCE
OF A QUARTER INCH OF ICE ACCUMULATION THURSDAY NIGHT AND FRIDAY
MORNING. WATCH CRITERIA THRESHOLD IS A 50 PERCENT CONFIDENCE LEVEL
WHILE WARNING IS 80 PERCENT. SO GOING BY THIS PIECE OF GUIDANCE WE
SHOULD ISSUE A WATCH NOW. HOWEVER IT IS CONCERNING THE SREF IS
STILL FORECASTING A MARGINAL FREEZING RAIN EVENT FOR THIS REGION
WHICH LOWERS OUR CONFIDENCE. IT IS ALSO CONCERNING THAT THE WARM
NOSE WILL BE VERY WARM...AND RAIN DROPS WILL LIKELY TRANSPORT WARM
AIR TO THE SURFACE...WHICH WOULD INHIBIT ICE ACCUMULATION AND
IMPACTS. ON THE FLIP SIDE IT IS VERY CONCERNING THAT THE AIR
TEMPERATURES MAY STAY BELOW FREEZING FOR MUCH OF THE CWA FRIDAY
AND SATURDAY WITH CLOUDY SKIES. THIS MEANS IF ICE AND/OR SLEET IS
SIGNIFICANT THURSDAY NIGHT AND FRIDAY MORNING...ICE ON ROADS MAY
LINGER INTO SATURDAY OR SUNDAY WHEN COINCIDENTALLY ANOTHER SHOT AT
WINTER PRECIP ARRIVES. THE ISSUE IS THAT THIS EVENT UNLIKE THE
LAST MARGINAL/NON-EVENT DOES HAVE THE POTENTIAL FOR PROLONGED
WINTRY IMPACTS WHICH IS MORE REASON TO RAISE PUBLIC AWARENESS NOW
AND GO AHEAD AND EXPAND THE WATCH SOUTHEASTWARD TO INCLUDE MORE
AREA.
NOTE THIS DOES NOT MEAN THE ENTIRE WATCH AREA WILL BE UPGRADED TO
A WARNING...BUT AT THIS POINT WE BELIEVE THE ENTIRE WATCH AREA
WILL BE IN AT LEAST A WINTER WEATHER ADVISORY THURSDAY NIGHT AND
FRIDAY MORNING. IT IS TOO EARLY TO FINE TUNE ACCUMULATION AMOUNTS
OR ENTERTAIN WHO WILL SEE WHAT IMPACTS...AND THOSE WILL COME LATER
AS CONFIDENCE INCREASES FURTHER.
TR.92
&&
.PREV DISCUSSION... /ISSUED 356 PM CST TUE DEC 3 2013/
WE ARE ISSUING A WINTER STORM WATCH FROM AREAS ALONG AND NORTHWEST
OF A BRECKENRIDGE TO GAINESVILLE LINE FOR THURSDAY NIGHT THROUGH
FRIDAY. CONFIDENCE IS HIGH ENOUGH WITHIN THIS AREA TO MEET
WARNING CRITERIA OF 1/4 INCH OR MORE OF ICE.
THE ARCTIC FRONT WILL MOVE SOUTH OF THE RED RIVER WEDNESDAY
EVENING AND OUT OF THE SOUTHERN COUNTIES BY MIDDAY THURSDAY.
TEMPERATURES WILL FALL RAPIDLY BEHIND THE FRONT AS TEMPERATURES
UPSTREAM ARE IN THE LOW TEENS OVER WYOMING AND IN THE SINGLE
DIGITS IN CANADA.
PRECIPITATION WILL BE MOSTLY POST-FRONTAL THURSDAY NIGHT-FRIDAY
WITH MODERATE RAINFALL POSSIBLE ALONG A COMANCHE TO PARIS LINE
WHERE RICK ELEVATED MOISTURE MOVES OVER THE ELEVATED FRONTAL
BOUNDARY. THE RAIN WILL CHANGE TO FREEZING RAIN OVER THE
NORTHWEST COUNTIES THURSDAY EVENING AND PROGRESS SOUTHEASTWARD
WITH THE 32F ISOTHERM TO NEAR A SULPHUR SPRINGS TO GOLDTHWAITE
LINE ON FRIDAY. DUE TO UNCERTAINTY IN THE DEPTH OF THE COLD
AIR...WARM SOILS/STREETS...LATENT HEAT RELEASE OF RESIDUAL WATER
FROM RAINFALL AND THE STRENGTH OF THE WARM NOSE ALOFT...THE
LOCATION OF THE RAIN/FREEZING RAIN TRANSITION ZONE WAS HARD TO
DETERMINE... BUT CONFIDENCE WAS HIGH ENOUGH TO ISSUE A WATCH FOR
THE NORTHWEST COUNTIES WITH THIS PACKAGE. THE WATCH MAY BE PUSHED
FURTHER SOUTHEAST IF FUTURE MODEL RUNS PRODUCE HIGHER CONFIDENCE
THAT SIGNIFICANT ICE ACCUMULATIONS WILL OCCUR ELSEWHERE.
THERE WILL BE A LULL IN THE PRECIPITATION FRIDAY NIGHT AS THE
UPPER DISTURBANCE MOVES EAST OF THE REGION. ISENTROPIC UPGLIDE AND
ANOTHER UPPER DISTURBANCE WILL BRING PRECIPITATION BACK TO THE
REGION SATURDAY THROUGH SUNDAY. THIS PRECIPITATION WILL BE LIGHTER
THAN THE PREVIOUS ROUND...BUT WILL BE SLEET AND FREEZING RAIN
DURING THE OVERNIGHT HOURS...BUT GENERALLY LIQUID WHERE DAYTIME
TEMPS WARM ABOVE FREEZING.
THIS WILL BE THE COLDEST AIR OF THE SEASON SO FAR WITH LOWS IN THE
TEENS AND 20S ON SEVERAL NIGHTS. DAYTIME TEMPS WILL TREND WARMER
SUNDAY AND MONDAY...BUT A REINFORCING SHOT OF ARCTIC AIR IS
EXPECTED TO SEND US BACK INTO THE ICEBOX BY TUESDAY MORNING.
75
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 55 77 38 44 28 / 0 5 20 60 90
WACO, TX 49 80 50 52 31 / 0 5 20 50 90
PARIS, TX 49 74 39 45 29 / 0 5 20 70 90
DENTON, TX 49 72 36 39 26 / 0 5 20 60 80
MCKINNEY, TX 48 75 38 42 27 / 0 5 20 60 90
DALLAS, TX 56 79 38 45 28 / 0 5 20 60 90
TERRELL, TX 52 77 42 47 29 / 0 5 20 60 90
CORSICANA, TX 54 77 50 50 31 / 0 5 20 60 90
TEMPLE, TX 52 81 56 56 32 / 0 5 20 50 80
MINERAL WELLS, TX 47 76 36 40 25 / 0 5 20 60 80
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY
AFTERNOON FOR TXZ094-095-104>107-118>120-130>133-141>144.
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
AFTERNOON FOR TXZ091>093-100>103-115>117-129.
&&
$$
82/92
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
955 AM EST WED DEC 4 2013
.DISCUSSION...
LATEST RUC ANALYSIS...MORNING SOUNDINGS...AND LCL WIND PROFILERS
TRACE OUT THE AXIS OF A BROAD HIGH PRES RIDGE DRAPED OVER THE S HALF
OF THE FL PENINSULA EXTENDING INTO THE SE GOMEX: S/SE WINDS THRU THE
H100-H85 LYR OVER S FL...BCMG SW OVER CNTRL AND N FL. MOISTURE THRU
THE COLUMN IS ON THE LOW SIDE...RANGING FM 1.0" AT KXMR TO 1.3" AT
KMFL. MODERATE UPSTREAM MOISTURE THRU THE H100-H85 LYR WITH MEAN RH
GENERALLY AOA 70PCT. HOWEVER...SUBSIDENCE INVERSIONS NOTED IN THE
H80-H70 LYR AS WELL AS THE H60-H45 LYR WILL KEEP THE LCL AIRMASS
WELL CAPPED.
LCL AIRMASS IS TOO DRY/STABLE TO PROMOTE ANY SHRA ACTIVITY OUTSIDE
OF THE GULF STREAM...AND ANY THAT DOES FORM WILL BE PUSHED OFFSHORE
BY THE PREVAILING SWRLY FLOW THRU THE H85-H50 LYR...FCST REMAINS
DRY. S/SWRLY WINDS WILL PUSH TEMPS INTO THE L/M80S OVER THE
INTERIOR...5-10F ABV AVG. TEMPS IN THE U70S/L80S ALONG THE COAST AS
A WEAK SFC PGRAD ALLOWS A SEA BREEZE TO FORM ALONG THE COAST BY MID
AFTN.
MRNG FCST PACKAGE LOOKS GOOD...NO NEED FOR UPDATES.
&&
.AVIATION...
VFR ALL SITES UNLESS OTHERWISE NOTED. BTWN 04/17Z-04/19Z...SFC
WNDSHFT FM S/SW TO SE AOB 10KTS CSTL SITES ASSOCD WITH THE EAST
COAST SEA BREEZE. BTWN 05/06Z-05/14Z...AREAS MVFR VSBYS/LCL IFR CIGS
IN BR AND STRATUS N OF KEVB-KISM...PTCHY MVFR VSBYS S OF KEVB-KISM
IN BR.
&&
.MARINE...
FAVORABLE BOATING CONDITIONS AS A BROAD HI PRES RIDGE CENTERED N OF
THE BAHAMAS BTWN BERMUDA AND THE CAROLINA COAST MAINTAINS A LIGHT TO
GENTLE S/SW BREEZE ACRS THE LCL ATLC. DATA BUOYS/C-MAN STATIONS
MEASURING SFC WINDS AOB 10KTS...SEAS AOB 2FT NEARSHORE AND 2-3FT
OFFSHORE WITH DOMINANT PDS AOA 8SEC. CURRENT FCST RUNNING A LITTLE
HIGH GIVEN THE CURRENT CONDITIONS...WILL LOWER SEAS BY A FOOT WITH
THE MORNING UPDATE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...MOSES
Area Forecast Discussion
National Weather Service Lincoln IL
1000 AM CST Wed Dec 4 2013
.DISCUSSION...
ISSUED 1000 AM CST Wed Dec 4 2013
Dense fog starting to slowly lift in some areas. Have lopped off a
few counties from the advisory from Springfield westward where
visibility has been more persistently around a mile or so. Seeing
some variable visibilities from Peoria northwest and also over the
southeast counties, and will evaluate over the next hour whether
to drop the advisory there too or let it ride until its natural
conclusion at noon. HRRR model showing a more persistent lifting
of the dense fog over the next couple hours, although the RAP
lingers it east of I-57 into early afternoon.
Latest surface map shows low pressure over central Missouri, with
a secondary low over south central Iowa which should become the
primary low late today. Should start seeing the cold front moving
into the Illinois River valley toward 5-6 pm and across most of
the CWA by 10 pm.
Geelhart
&&
.AVIATION...
ISSUED 515 AM CST Wed Dec 4 2013
High resolution models continue to suggest areas that have seen a
temporary break in the low vsbys and cigs will see deteriorating
conditions once again around or just after daybreak this morning.
Model trends off the HRRR and HopWRF continue to suggest VLIFR
vsbys/cigs expanding north into all of our TAF sites after 12z.
Confidence not that great with this scenario...although we have
seen a gradual lowering of cigs and vsbys in areas that saw some
improvement earlier this morning. Poorest conditions look to be
from 12 or 13z thru 18z...and then LIFR/IFR cigs most areas this
afternoon just ahead of a cold front which is currently tracking
across Iowa. Looks as if the cold front should start to push into
our western taf sites by 00z and be east of the CMI area by
05 or 06z tonight. Surface winds ahead of the front will remain
out of the southeast to south at 10 to 15 kts today...and then
shift into west and then northwest after FROPA later this evening.
Smith
&&
.PREV DISCUSSION...
ISSUED 311 AM CST Wed Dec 4 2013
Main forecast concern continues to be potential for accumulating
snow and ice across parts of central Illinois late Thursday into
Friday.
SHORT TERM...Today through Friday
Widespread fog once again blankets the area early this morning.
Moist low-level airmass remains in place, with 08z/2am surface
dewpoints well into the 40s. This ample moisture combined with
light winds will allow visibilities to continue to drop over the
next couple of hours. NAM/GFS forecast soundings and latest HRRR
visby forecast all point to widespread dense fog through much of
the morning. Will therefore be issuing a Dense Fog Advisory for
the entire KILX CWA through midday. Fog will gradually dissipate
by early afternoon, although visibilities will continue to be
somewhat limited until cold front pushes through late this
afternoon into the evening. Despite FROPA later today, shallow
moisture below 5000ft will limit precip potential. Will therefore
only mention isolated showers today into this evening. High
temperatures will be quite a bit warmer than they were yesterday,
but will be tempered by the fog/clouds to some extent. Will go
near or slightly above MAV guidance numbers, but not as high as
the warmer MET. Resulting highs will mainly be in the upper 50s
and lower 60s.
Once front passes, much colder air will arrive tonight into
Thursday. Overnight lows will drop into the upper 20s and lower
30s across much of the area, but will remain in the upper 30s
further east near the Indiana border. High temperatures on
Thursday will not rise much from the early morning lows, with
readings ranging from the upper 20s along/west of the Illinois
River to around 40 degrees along the Wabash River.
Models are in good agreement with the development of wintry precip
across parts of central and southeast Illinois late Thursday into
Friday, with a few minor differences still remaining. NAM has
slowed the onset of precip until early evening, while GFS/ECMWF/GEM
still bring it in during the afternoon. Given drier airmass behind
departing front, think NAM may have the right idea. Will therefore
delay initial precip development until late afternoon, with main
push arriving during the evening. Airmass will be cold enough to
support snow across most of the area: however, warm layer aloft
with max temps of around 4C supports mixed phase precip along and
south of I-70. Late afternoon surface temps in the upper 30s to
around 40 will allow for mainly rain along and south of highway
50. As the evening progresses, deepening cold layer will allow for
a gradual change over to mainly snow across the SE KILX CWA
overnight, although areas along and south of highway 50 may
experience a period of freezing rain as surface temps dip below
32 degrees. Any icing will be minimal, as precip transitions to
snow/sleet after midnight.
Initial wave of precip wanes after midnight, followed by another
wave on Friday. Model differences here focus on how far into the
cold airmass to spread the precip. NAM is most aggressive, while
GFS remains further southeast. Given strength of approaching high
within the cold airmass, think GFS solution is most logical. As a
result, will focus highest POPs for snow across the E/SE CWA. Once
the wintry precip ends Friday afternoon, total snowfall
accumulations of 3 to 5 inches will be likely along and south of
I-70. Amounts will steadily decrease further northwest, with up
to 1 inch possible along a Jacksonville to Danville line. Further
north, only a few flurries are expected along and north of a
Rushville to Bloomington-Normal line.
LONG TERM...Saturday through Tuesday
Cold weather will prevail throughout the extended, with only a brief
moderation in temps expected on Sunday. Models continue to show
another short-wave trough digging southward into the western
CONUS this weekend, resulting in downstream ridging over the
southeast states. As flow becomes more southwesterly aloft,
frontal boundary along the Gulf Coast will get pushed back
northward Sunday into Monday. It appears deepest moisture and
highest precip chances will remain southeast of Illinois across
the Tennessee and Ohio River Valleys, although the GFS is slightly
more aggressive in bringing precip further northwest into the cold
air than the ECMWF. At this point, will trend toward the ECMWF and
will only feature low chance POPs for snow Sunday and Sunday night
with minimal accumulations. After that, another very cold airmass
will drop into the Midwest by early next week, resulting in high
temps in the teens by Tuesday.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until noon CST today for ILZ027>031-036>038-
041>046-052>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
551 AM CST WED DEC 4 2013
.DISCUSSION...
406 AM CST
FORECAST CONCERNS THIS MORNING FOCUS ON DENSE FOG TRENDS THIS
MORNING...AND TRENDS INTO THIS AFTERNOON WITH MILD TEMPS UNTIL COLD
FROPA LATE AFTERNOON/EVENING. COLDER AIR COMES IN TWO PUSHES...
FIRST BEHIND THE FRONT TONIGHT AND THEN A SECOND PUSH FRIDAY
NIGHT-SATURDAY AS ARCTIC HIGH BUILDS MORE SOLIDLY EAST ACROSS THE
GREAT LAKES REGION. COUPLE OF CHANCES OF SOME LIGHT ACCUMULATING
SNOW IN THE COMING DAYS...INITIALLY ACROSS FAR SOUTHEAST CWA LATE
THURSDAY INTO FRIDAY...AND AND ACROSS THE CWA SUNDAY-SUNDAY NIGHT.
EVEN COLDER PUSH OF ARCTIC AIR APPEARS HEADED FOR THE AREA BY THE
MIDDLE OF NEXT WEEK.
VERY MILD AND MOIST AIR MASS IN PLACE ACROSS THE REGION EARLY THIS
MORNING...WITH BOTH SFC TEMPS AND DEW POINTS IN THE 40S WITH VERY
SMALL DEPRESSIONS. DENSE FOG WITH VISIBILITY LESS THAN 1/2SM
CONTINUES ACROSS THE FAR NORTHERN IL COUNTIES ROUGHLY NORTH OF A
STERLING TO DEKALB AND WAUKEGAN LINE AS OF 330 AM CST...WITH A
SMALLER AREA OF DENSE FOG OVER EAST CENTRAL IL. HIGH-RES GUIDANCE
INCLUDING HOPWRF AND NARRE TIME-LAGGED ENSEMBLES INDICATE THERE MAY
BE SOME IMPROVEMENT IN VISIBILITY ACROSS THE NORTHERN COUNTIES THIS
MORNING...WHILE SOME ENSEMBLE MEMBERS EXPAND DENSE FOG ACROSS
CENTRAL IL PRIOR TO ABOUT 15Z AND THEN DECREASE COVERAGE. OBS AT
PNT-IKK AND RZL HAVE NOT SHOWN A SIGNIFICANT DOWNWARD TREND AT THIS
TIME. WILL LEAVE ONGOING DENSE FOG ADVISORY ACROSS THE NORTH AS
IS...AND WILL CONTINUE TO MONITOR TRENDS ACROSS THE SOUTH FOR THE
POSSIBILITY OF NEEDING A HEADLINE THERE. WHILE VISIBILITY MAY
IMPROVE SOMEWHAT...AREAS OF FOG WILL LIKELY STICK AROUND INTO THE
AFTERNOON BEFORE AN INCREASE IN SCATTERED SHOWER COVERAGE...WARMER
DAYTIME TEMPERATURES AND THE EVENTUAL COLD FRONTAL PASSAGE CLEAR
THINGS OUT THIS EVENING.
WHILE COLDER MORE TYPICAL EARLY WINTER WEATHER WILL SPREAD INTO THE
AREA TONIGHT/THURSDAY...THE DEPARTING COLD FRONT WILL SLOW AS IT
BECOMES PARALLEL WITH THE MID/UPPER FLOW AND MOVES INTO THE EASTERN
LAKES AND OHIO VALLEY OVER THE NEXT 24-36 HOURS. THIS WILL LIMIT THE
EXTENT OF THE COLD AIR INTRUSION BEHIND THE FRONT...AND WILL LEAVE
THE ELEVATED FRONTAL ZONE ACROSS CENTRAL IL AND NORTHERN INDIANA
INTO FRIDAY. GUIDANCE REMAINS FAIRLY SIMILAR IN BRINGING TWO
SEPARATE DISTURBANCES ALONG THIS BAROCLINIC ZONE WITH THE FIRST LATE
THURSDAY/THURSDAY NIGHT...AND THE OTHER DURING THE DAY ON FRIDAY.
REASONABLY SIMILAR QPF OUTPUT FROM THE VARIOUS MODELS OF THE
AVAILABLE GUIDANCE INDICATE THE POTENTIAL FOR GENERALLY LESS THAN AN
INCH OF SNOW ACROSS THE FAR SOUTHEAST TIER OF COUNTIES OF THE CWA
BEFORE THE SECOND SHORT WAVE DEPARTS LATE FRIDAY...WITH FLURRIES
PERHAPS AS FAR NORTH AS A PONTIAC-WHITING LINE. AFTER THIS SECOND
SLIGHTLY MORE AMPLIFIED WAVE DEPARTS...ARCTIC HIGH PRESSURE BUILDS
MORE ROBUSTLY EAST ACROSS MINNESOTA AND WISCONSIN FRIDAY NIGHT AND
SETS THE STAGE FOR CHILLY TEMPS IN THE SINGLE DIGITS AWAY FROM THE
CITY FRIDAY NIGHT...AND ONLY IN THE TEENS TO LOW 20S SATURDAY.
LONGER RANGE GUIDANCE ALSO REMAINS IN DECENT AGREEMENT IN BRINGING
ANOTHER SHORT WAVE INTO THE REGION SUNDAY-SUNDAY NIGHT...WITH SOME
SPREAD IN THE MODEL SOLUTIONS LOOKING A LITTLE MORE IN AGREEMENT
WITH THE NEW 00Z ECMWF SIMILAR TO THE GFS IN BRINGING LOW PRESSURE
THROUGH THE OHIO VALLEY DURING THAT TIME. LIGHT SNOW LOOKS TO COVER
MOST/ALL OF THE CWA WITH THIS SYSTEM...AND HAVE BUMPED POPS TO
LIKELY IN MOST AREAS.
ANOTHER SURGE OF ARCTIC AIR THEN LOOKS TO SPREAD INTO THE AREA
BEHIND THIS SYSTEM MONDAY-TUESDAY. BOTH ECMWF/GFS MOS GUIDANCE
SHOWING LOWS IN THE SINGLE DIGITS BY TUESDAY MORNING...WITH HIGHS
ONLY AROUND 12-15 TUESDAY. THIS IS IMPRESSIVE GIVEN STRONG CLIMO
WEIGHTING IN THE MOS BY DAY 7...SOME 22-25 DEGREES BELOW NORMAL FOR
HIGHS FOR EARLY DECEMBER. BRRR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* VARIABLE CIGS THIS MORNING...BECOMING PREVAILING IFR MID MORNING
THROUGH LATE AFTERNOON...WITH SLIGHT IMPROVEMENT POSSIBLE
THEREAFTER.
* VISIBILITY TRENDS...WITH POTENTIAL FOR FOG TO SPREAD NORTH INTO
THE TERMINALS.
BMD
//DISCUSSION...UPDATED 12Z...
THIS MORNING...A WARM FRONT LIES JUST NORTH OF THE TERMINALS WITH
SOUTHEAST FLOW AND IFR CONDITIONS IN PLACE ACROSS NORTHERN ILLINOIS
AND NORTHWEST INDIANA. WILL DISCUSS EACH FORECAST ELEMENT
INDIVIDUALLY...
CEILINGS...AS MENTIONED MOST OF THE REGION IS UNDER IFR CIGS THIS
MORNING...THOUGH THERE IS A HOLE IN THE LOWER CIGS THAT STRETCHES
FROM SW MICHIGAN INTO THE SOUTH CHICAGO METRO. GYY HAS MAINTAINED
VFR LEVEL CIGS FOR THE PAST SEVERAL HOURS...AND MDW HAS BEEN IN AND
OUT OF THE IFR CIGS. NAM/HRRR GUIDANCE TO SOME DEGREE HINTING AT
THIS HOLE...WHICH COULD BRIEFLY MOVE OVER ORD THIS MORNING. BOTH
MODELS DO SHOW THE HOLE FILLING IN THOUGH LATE THIS MORNING...SO ANY
TEMPO HIGHER CIGS WILL BE SHORT LIVED THIS MORNING. A SECONDARY WARM
FRONTAL LIKE FEATURE WILL LIFT ACROSS THE AREA THIS AFTERNOON...WITH
WINDS VEERING TO THE S OR SSW. MODELS INDICATE SOME IMPROVEMENT IN
CIGS POSSIBLE AFTER IT PASSES NORTH OF THE TERMINALS...THOUGH THE
DEGREE OF IMPROVEMENT IS UNCERTAIN. IT IS POSSIBLE WE MAY LIFT TO
MVFR AT THIS POINT...BUT WILL ERR ON THE SIDE OF LOWER CIGS FOR NOW
WHICH FITS WELL WITH LAV/MET GUIDANCE. BETTER CHANCE TO LIFT TO MVFR
WILL BE LATER IN THE EVENING AS A COLD FRONT SWEEPS ACROSS THE AREA.
EXPECT THE CIGS TO GRADUALLY RISE OVERNIGHT AS THE COLD AIR ERODES
THE CLOUD BASES.
VISIBILITY...VSBY RANGES FROM NEAR ZERO TO AROUND 4-5SM. DENSEST FOG
IS GENERALLY ALONG AND NEAR THE WARM FRONT AND THIS AREA SHOULD STAY
NORTH OF THE CHICAGO TERMINALS...THOUGH WILL CONTINUE TO IMPACT RFD
THROUGH THE MORNING. MODEL GUIDANCE IS ALL OVER THE PLACE WITH
RESPECT TO VSBY TRENDS TODAY. SEVERAL MODELS HINT THAT AS THE
SECONDARY BOUNDARY SOUTH OF THE AREA LIFTS NORTH...LOWER VSBY WILL
ALSO SPREAD NORTH INTO THE CHICAGO METRO. THERE IS ALREADY DENSE FOG
ACROSS PORTIONS OF EAST CENTRAL ILLINOIS...AND WILL HAVE TO MONITOR
THIS AREA CLOSELY AS IT MAY SPREAD NORTH OVER THE TERMINALS...BUT
FOR NOW GIVEN THE LOW CONFIDENCE...WILL STICK CLOSE TO MAV/LAV
TRENDS WHICH HOLD VSBY PRIMARILY MVFR FOR THE CHICAGO TERMINALS
TODAY. ANY PRECIP THAT DEVELOPS THIS AFTERNOON MAY ALSO CAUSE THE
VSBY TO DROP TO IFR.
WINDS...PRIMARILY SOUTHEASTERLY WINDS 6-10KTS ARE EXPECTED THIS
MORNING BEHIND THE FRONT NEAR THE STATE LINE THIS MORNING. WINDS
WILL EVENTUALLY VEER TO THE SOUTH/SSW AS THE SECOND BOUNDARY LIFTS
ACROSS THE AREA MID TO LATE THIS AFTERNOON. LATE THIS EVENING A COLD
FRONT WILL SWEEP ACROSS THE AREA WITH WINDS TURNING WESTERLY...AND
INCREASING WITH GUSTS INTO THE HIGH TEENS EXPECTED OVERNIGHT.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE IN CIG TRENDS THROUGH THE PERIOD.
* LOW CONFIDENCE IN VSBY TRENDS THIS MORNING THROUGH THIS AFTERNOON.
* MEDIUM CONFIDENCE IN WINDS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH SATURDAY...VFR.
SUNDAY...CHC SNOW...WITH SNOW LIKELY SUNDAY NIGHT.
MONDAY...SLT CHC SNOW. MVFR POSSIBLE.
TUESDAY...PRIMARILY VFR.
BMD
&&
.MARINE...
239 AM CST
MODELS ARE FINALLY SYNCED UP ON DEEPENING LOW PRESSURE WHICH IS
EXPECTED TO LIFT ACROSS WISCONSIN LATE THIS AFTERNOON...AND ACROSS
LATE SUPERIOR TONIGHT. MODERATE EASTERLY FLOW AROUND 30 KTS IS
EXPECTED NORTH OF A WARM FRONT STRADDLING THE MID SECTION OF THE
LAKE THIS MORNING...WITH STABLE SOUTHEASTERLY FLOW ACROSS THE SOUTH
OF THE FRONT. MID/UPPER 40 DEWPOINTS ADVECTING OVER THE LOW/MID 40
DEGREE WATER TEMPERATURES IS EXPECTED TO RESULT IN WIDESPREAD DENSE
FOG. A DENSE FOG ADVISORY IS IN EFFECT ACROSS THE SOUTH HALF OF THE
LAKE...BUT MAY NEED TO BE EXTENDED NORTH AS THE FRONT LIFTS ACROSS
THE REMAINDER OF THE LAKE. OVERNIGHT A COLD FRONT WILL SWEEP ACROSS
THE LAKE WITH WINDS TURNING WESTERLY BEHIND. STRONG COLD ADVECTION
WILL HELP TO MIX DOWN GALES...PRIMARILY ACROSS THE NORTH END OF THE
LAKE WHERE THE GRADIENT IS TIGHTEST...THOUGH APPEARS FOR NOW TO BE
LOW END GALE EVENT. A GALE WATCH REMAINS IN EFFECT FOR THE NORTH
PORTIONS OF THE LAKE. A STRONG HIGH WILL SETTLE ACROSS THE NORTHERN
PLAINS FRIDAY THOUGH LATE SATURDAY RESULTING IN WINDS STAYING
ELEVATED IN THE 20 TO 25 KT RANGE...WITH A FEW PERIODS OF 30 KTS.
ANOTHER LOW IS EXPECTED TO LIFT FROM THE LOWER MISSISSIPPI VALLEY
INTO THE EASTERN LAKES REGION EARLY NEXT WEEK.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012 UNTIL 10 AM WEDNESDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM WEDNESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 AM THURSDAY TO 3 PM THURSDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...11 PM
WEDNESDAY TO 3 PM THURSDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...1 AM THURSDAY TO 4 AM
FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
527 AM CST Wed Dec 4 2013
.DISCUSSION...
ISSUED 311 AM CST Wed Dec 4 2013
Main forecast concern continues to be potential for accumulating
snow and ice across parts of central Illinois late Thursday into
Friday.
SHORT TERM...Today through Friday
Widespread fog once again blankets the area early this morning.
Moist low-level airmass remains in place, with 08z/2am surface
dewpoints well into the 40s. This ample moisture combined with
light winds will allow visibilities to continue to drop over the
next couple of hours. NAM/GFS forecast soundings and latest HRRR
visby forecast all point to widespread dense fog through much of
the morning. Will therefore be issuing a Dense Fog Advisory for
the entire KILX CWA through midday. Fog will gradually dissipate
by early afternoon, although visibilities will continue to be
somewhat limited until cold front pushes through late this
afternoon into the evening. Despite FROPA later today, shallow
moisture below 5000ft will limit precip potential. Will therefore
only mention isolated showers today into this evening. High
temperatures will be quite a bit warmer than they were yesterday,
but will be tempered by the fog/clouds to some extent. Will go
near or slightly above MAV guidance numbers, but not as high as
the warmer MET. Resulting highs will mainly be in the upper 50s
and lower 60s.
Once front passes, much colder air will arrive tonight into
Thursday. Overnight lows will drop into the upper 20s and lower
30s across much of the area, but will remain in the upper 30s
further east near the Indiana border. High temperatures on
Thursday will not rise much from the early morning lows, with
readings ranging from the upper 20s along/west of the Illinois
River to around 40 degrees along the Wabash River.
Models are in good agreement with the development of wintry precip
across parts of central and southeast Illinois late Thursday into
Friday, with a few minor differences still remaining. NAM has
slowed the onset of precip until early evening, while GFS/ECMWF/GEM
still bring it in during the afternoon. Given drier airmass behind
departing front, think NAM may have the right idea. Will therefore
delay initial precip development until late afternoon, with main
push arriving during the evening. Airmass will be cold enough to
support snow across most of the area: however, warm layer aloft
with max temps of around 4C supports mixed phase precip along and
south of I-70. Late afternoon surface temps in the upper 30s to
around 40 will allow for mainly rain along and south of highway
50. As the evening progresses, deepening cold layer will allow for
a gradual change over to mainly snow across the SE KILX CWA
overnight, although areas along and south of highway 50 may
experience a period of freezing rain as surface temps dip below
32 degrees. Any icing will be minimal, as precip transitions to
snow/sleet after midnight.
Initial wave of precip wanes after midnight, followed by another
wave on Friday. Model differences here focus on how far into the
cold airmass to spread the precip. NAM is most aggressive, while
GFS remains further southeast. Given strength of approaching high
within the cold airmass, think GFS solution is most logical. As a
result, will focus highest POPs for snow across the E/SE CWA. Once
the wintry precip ends Friday afternoon, total snowfall
accumulations of 3 to 5 inches will be likely along and south of
I-70. Amounts will steadily decrease further northwest, with up
to 1 inch possible along a Jacksonville to Danville line. Further
north, only a few flurries are expected along and north of a
Rushville to Bloomington-Normal line.
LONG TERM...Saturday through Tuesday
Cold weather will prevail throughout the extended, with only a brief
moderation in temps expected on Sunday. Models continue to show
another short-wave trough digging southward into the western
CONUS this weekend, resulting in downstream ridging over the
southeast states. As flow becomes more southwesterly aloft,
frontal boundary along the Gulf Coast will get pushed back
northward Sunday into Monday. It appears deepest moisture and
highest precip chances will remain southeast of Illinois across
the Tennessee and Ohio River Valleys, although the GFS is slightly
more aggressive in bringing precip further northwest into the cold
air than the ECMWF. At this point, will trend toward the ECMWF and
will only feature low chance POPs for snow Sunday and Sunday night
with minimal accumulations. After that, another very cold airmass
will drop into the Midwest by early next week, resulting in high
temps in the teens by Tuesday.
&&
.AVIATION...
ISSUED 515 AM CST Wed Dec 4 2013
High resolution models continue to suggest areas that have seen a
temporary break in the low vsbys and cigs will see deteriorating
conditions once again around or just after daybreak this morning.
Model trends off the HRRR and HopWRF continue to suggest VLIFR
vsbys/cigs expanding north into all of our TAF sites after 12z.
Confidence not that great with this scenario...although we have
seen a gradual lowering of cigs and vsbys in areas that saw some
improvement earlier this morning. Poorest conditions look to be
from 12 or 13z thru 18z...and then LIFR/IFR cigs most areas this
afternoon just ahead of a cold front which is currently tracking
across Iowa. Looks as if the cold front should start to push into
our western taf sites by 00z and be east of the CMI area by
05 or 06z tonight. Surface winds ahead of the front will remain
out of the southeast to south at 10 to 15 kts today...and then
shift into west and then northwest after FROPA later this evening.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until Noon CST today FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1100 AM EST WED DEC 4 2013
.UPDATE...
ISSUED AT 1100 AM EST WED DEC 4 2013
BASED ON LATEST TRENDS...INCLUDING A FEW MORE BREAKS IN THE
CLOUDS...HAVE INCREASED AFTERNOON MAXIMUM TEMPERATURES. WILL INCLUDE
SPRINKLES FOR THE START OF THE FORECAST PERIOD IN THE NORTH AND EAST.
HAVE UPDATED NDFD...WEB FORECASTS AND ZFP.
UPDATE ISSUED AT 853 AM EST WED DEC 4 2013
UPDATED NDFD...WEB FORECASTS AND ZFP TO INCLUDE ISOLATED SHOWERS THIS
MORNING ACROSS THE WESTERN AND CENTRAL PARTS OF THE FORECAST AREA.
THIS IS SUPPORTED BY CURRENT RADAR TRENDS AND LATEST HRRR GUIDANCE.
CURRENT EXPECTATIONS ARE FOR ISOLATED SHOWERS TO END BY EARLY AFTERNOON.
UPDATE ISSUED AT 651 AM EST WED DEC 4 2013
CLOUD COVER HAS PRETTY MUCH RETURNED ACROSS THE AREA AND SHOULD
PERSIST THROUGH A GOOD CHUNK OF THE DAY ONCE AGAIN AS A WARM FRONT
PUSHES NORTH TOWARDS THE AREA. SOME QUESTION AS TO IF THIS BOUNDARY
WILL CLEAR THE AREA BEFORE SUNSET. IF IT FAILS TO DO SO...CLOUD COVER
MAY HOLD FOR THE REMAINDER OF THE DAY. A FEW BREAKS CAN STILL BE
EXPECTED IN THE SOUTHEAST WITH DOWNSLOPING FLOW...BUT FOR THE MOST
PART...CLOUDY WILL BE THE WAY TO GO TODAY. COULD BE SOME VERY PATCHY
DRIZZLE OUT THERE THIS MORNING...BUT LIKELY CONFINED TO AREAS MORE
SOUTH AND WEST OF HERE. NO UPDATE PLANNED EARLY THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 308 AM EST WED DEC 4 2013
SATELLITE THIS MORNING REVEALS A STORM SYSTEM TAKING SHAPE OVER THE
NORTHERN PLAINS...WITH SOUTHERLY FLOW ACROSS THE MAJORITY OF THE
OHIO/TENNESSEE RIVER VALLEYS. WHILE WINDS REMAIN MOSTLY SOUTH...THERE
IS A SLIGHT EASTERLY COMPONENT TO THE WIND WHICH IS CONTINUING TO EAT
AWAY AT CLOUD COVER FROM TIME TO TIME OVER EASTERN KENTUCKY. THE
UNFAVORABLE DOWNSLOPING CONDITIONS WILL LIKELY BE OVERTAKEN THIS
MORNING AS A WARM FRONT LIFTS NORTH ACROSS THE AREA. THIS WILL YIELD
MOSTLY CLOUDY TO CLOUDY SKIES THROUGH A GOOD CHUNK OF THE DAY TODAY.
PREVIOUS THINKING WAS THE WARM FRONT WOULD SHOOT ON THROUGH...BUT NOW
LOOKS LIKE CLOUDS MAY HOLD OVER MUCH OF THE AREA THROUGH THE DAY.
THIS WILL LIKELY SUPPRESS TEMPERATURES. REGARDLESS...ADVECTION ALONE
SHOULD ALLOW TEMPERATURE TO CLIMB INTO THE LOW TO MID 60S. AREAS IN
THE SOUTHWEST HAVE A BETTER CHANCE OF CLEARING AND WE COULD SEE SOME
READINGS GETTING CLOSE TO 70. CLOUDS SHOULD CONTINUE ERODING INTO
TONIGHT...BUT SOUTHERLY WINDS ARE EXPECTED TO REMAIN IN TACT TONIGHT
WITH A GOOD GRADIENT. THIS WILL ALLOW OVERNIGHT LOWS TO REMAIN VERY
MILD WITH READINGS IN THE 50S (HIGHER THAN OUR AVERAGE HIGHS FOR THIS
TIME OF YEAR).
BY LATE TONIGHT...AND ESPECIALLY TOMORROW...ISENTROPIC ASCENT WILL
KICK INTO FULL GEAR WITH PRECIPITATION DEVELOPING ACROSS CENTRAL AND
EASTERN KENTUCKY. MODELS HAVE SLOWED DOWN THE ADVANCING COLD
FRONT...SO HAVE SLOWED DOWN PRECIPITATION CHANCES. IT DOES LOOK LIKE
PRECIPITATION SHOULD EASILY IMPACT THE I-75 CORRIDOR ON THURSDAY...BUT
RAIN MAY MAKE IT AS FAR AS FAR EASTERN KENTUCKY BY LATE IN THE DAY.
REGARDLESS...CONFIDENCE IS NOT AS HIGH IN THE EAST...SO HAVE GONE
WITH AN EAST TO WEST GRADIENT IN POPS. INITIAL RAINFALL TOTALS ON
THURSDAY ARE NOT EXPECTED TO BE TOO HIGH GIVEN THE INITIAL DRY AIR
TO OVERCOME. HOWEVER...SOME TOTALS NEAR A HALF INCH MAY BE POSSIBLE
NEAR THE I-75 CORRIDOR BY LATE IN THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 440 AM EST WED DEC 4 2013
EXCESSIVE RAINFALL STILL LOOKS ON TRACK THROUGH EARLY NEXT
WEEK...ALTHOUGH MODEL GUIDANCE HAS TRENDED A BIT LEANER WITH THE
FIRST BATCH OF RAINFALL...WITH 2 TO 2.5 INCHES OF RAIN SUGGESTED
NOW...AND THEN SIMILAR TOTALS OCCURRING FROM SUNDAY THROUGH MONDAY.
THIS WOULD YIELD 4 DAY TOTALS IN THE 4 TO 5 INCH RANGE...WITH LARGER
CREEKS...STREAMS...AND RIVERS SEEING THE BEST CHANCE OF FLOODING
GIVEN THE LONG DURATION OF THE PRECIPITATION. WILL CONTINUE TO
HIGHLIGHT THESE CONCERNS IN AN ONGOING HYDROLOGIC OUTLOOK.
THE COLD FRONT WILL HAVE SETTLED JUST OFF TO THE SOUTHEAST OF OUR
AREA THURSDAY NIGHT. IT WILL CONTINUE TO SAG SOUTHEAST AND PIVOT A
BIT MORE AS SURFACE WAVES TRAVERSE THE BOUNDARY. THE RAIN MAY FALL
HEAVY AT TIMES THURSDAY NIGHT AND PARTICULARLY FRIDAY AS THE
STRONGEST UPPER LEVEL JET MOVES THROUGH THE GREAT LAKES AND LEAVES
MUCH OF THE OHIO VALLEY IN A FAVORABLE RIGHT ENTRANCE REGION.
SOME LIGHT SLUSHY ACCUMULATION STILL LOOKS LIKE A POSSIBILITY
GENERALLY ALONG AND NORTH OF THE MOUNTAIN PARKWAY. THE COLD AIR
ADVECTION HAS TRENDED A BIT QUICKER...SO THERE MAY BE A 1 TO 2 HOUR
WINDOW OF DECENT ENOUGH SNOWFALL RATES TO OVERCOME THE WARM GROUND
TEMPERATURES TEMPORARILY HEADING INTO DUSK. WILL AWAIT FURTHER MODEL
CONSISTENCY BEFORE DRAWING MORE ATTENTION TO THIS POTENTIAL AS IMPACT
OVERALL STILL LOOKS ON THE LOW SIDE.
PRECIPITATION WILL TAPER OFF QUICKLY FRIDAY NIGHT FROM NORTHWEST TO
SOUTHEAST AS COLDER AND MUCH DRIER AIR ADVECT IN FROM HIGH PRESSURE
SETTLING IN ACROSS THE PLAINS. DRY AND MUCH COLDER WEATHER IS
EXPECTED FOR SATURDAY...WITH HIGHS RANGING FROM THE LOWER 30S NORTH
OF I-64...TO THE LOWER 40S BORDERING TENNESSEE.
THE NEXT PRECIPITATION EVENT WILL THEN THREATEN EASTERN KENTUCKY BY
SATURDAY NIGHT...AS AN INVERTED SURFACE TROUGH BECOMES RE-ESTABLISHED
ACROSS THE LOWER MISSISSIPPI VALLEY. THE PRECIPITATION WILL BEGIN AS
SNOW ESPECIALLY NORTH OF THE HAL ROGERS PARKWAY AND HIGHWAY 80
CORRIDORS...HOWEVER THE WARM NOSE LOOKS TO OVERWHELM THE COLD AIR
QUICKLY...SO IT LOOKS TO BE ANOTHER MORE LIMITED WINDOW OF SNOW AND
POSSIBLY AN ALTERNATIVE TYPE OF PRECIPITATION DEPENDING ON HOW COLD
IT CAN GET SATURDAY NIGHT AND THE FURTHER EVOLUTION OF THE SYSTEM.
EXPECT A TRANSITION TO ALL RAIN THROUGH SUNDAY...AS A MORE ROBUST
SURFACE WAVE DEVELOPS ALONG THE BOUNDARY IN THE GULF AND HEADS
NORTHEAST. THIS SURFACE LOW WILL CONTINUE TO DEEPEN AS IT HEADS INTO
THE GREAT LAKES BY MONDAY. THE HEAVIEST RAIN LOOKS TO FALL ACROSS
EASTERN KENTUCKY SUNDAY NIGHT INTO MONDAY AS UPPER LEVEL DYNAMICS ARE
MAXIMIZED ONCE AGAIN ACROSS THE OHIO VALLEY. MUCH COLDER AIR WILL
MOVE IN BEHIND THE COLD FRONT...ONCE IT GETS DRAGGED TOWARDS THE
EASTERN SEABOARD LATE MONDAY. EXPECT SOME BACKSIDE SNOW ONCE
AGAIN...HOWEVER WITH DEEPER MOISTURE EXITING...AM ONLY SEEING LIGHT
ACCUMULATIONS RIGHT NOW. TUESDAY HIGHS WILL STRUGGLE TO REACH THE
FREEZING MARK AT MOST LOCATIONS...WITH DRY WEATHER RETURNING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 651 AM EST WED DEC 4 2013
MVFR CIGS WILL CONTINUE THROUGH MUCH OF THE MORNING BEFORE LIFTING
BACK TO VFR THIS AFTERNOON. WITH THE WARM FRONT PUNCHING THROUGH THE
AREA LATE IN THE DAY...CLOUDS SHOULD GIVE WAY TO ONLY SOME MID/HIGH
CLOUDS FOR THE OVERNIGHT HOURS. A COLD FRONT WILL PUSH TOWARDS THE
AREA BY LATE IN THE PERIOD...BUT CLOUDS SHOULD REMAIN VFR THROUGH
18Z. THE POSSIBILITY OF SOME LOW LEVEL WIND SHEAR WILL BEGIN BY LATE
IN THE DAY CONTINUING THROUGH TONIGHT...BUT NOT CONFIDENT ON HOW
MIXED THE SURFACE WILL BE TO INCLUDE IN THE TAF AT THE MOMENT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...KAS
LONG TERM...GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
854 AM EST WED DEC 4 2013
.UPDATE...
ISSUED AT 853 AM EST WED DEC 4 2013
UPDATED NDFD...WEB FORECASTS AND ZFP TO INCLUDE ISOLATED SHOWERS THIS
MORNING ACROSS THE WESTERN AND CENTRAL PARTS OF THE FORECAST AREA.
THIS IS SUPPORTED BY CURRENT RADAR TRENDS AND LATEST HRRR GUIDANCE.
CURRENT EXPECTATIONS ARE FOR ISOLATED SHOWERS TO END BY EARLY AFTERNOON.
UPDATE ISSUED AT 651 AM EST WED DEC 4 2013
CLOUD COVER HAS PRETTY MUCH RETURNED ACROSS THE AREA AND SHOULD
PERSIST THROUGH A GOOD CHUNK OF THE DAY ONCE AGAIN AS A WARM FRONT
PUSHES NORTH TOWARDS THE AREA. SOME QUESTION AS TO IF THIS BOUNDARY
WILL CLEAR THE AREA BEFORE SUNSET. IF IT FAILS TO DO SO...CLOUD COVER
MAY HOLD FOR THE REMAINDER OF THE DAY. A FEW BREAKS CAN STILL BE
EXPECTED IN THE SOUTHEAST WITH DOWNSLOPING FLOW...BUT FOR THE MOST
PART...CLOUDY WILL BE THE WAY TO GO TODAY. COULD BE SOME VERY PATCHY
DRIZZLE OUT THERE THIS MORNING...BUT LIKELY CONFINED TO AREAS MORE
SOUTH AND WEST OF HERE. NO UPDATE PLANNED EARLY THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 308 AM EST WED DEC 4 2013
SATELLITE THIS MORNING REVEALS A STORM SYSTEM TAKING SHAPE OVER THE
NORTHERN PLAINS...WITH SOUTHERLY FLOW ACROSS THE MAJORITY OF THE
OHIO/TENNESSEE RIVER VALLEYS. WHILE WINDS REMAIN MOSTLY SOUTH...THERE
IS A SLIGHT EASTERLY COMPONENT TO THE WIND WHICH IS CONTINUING TO EAT
AWAY AT CLOUD COVER FROM TIME TO TIME OVER EASTERN KENTUCKY. THE
UNFAVORABLE DOWNSLOPING CONDITIONS WILL LIKELY BE OVERTAKEN THIS
MORNING AS A WARM FRONT LIFTS NORTH ACROSS THE AREA. THIS WILL YIELD
MOSTLY CLOUDY TO CLOUDY SKIES THROUGH A GOOD CHUNK OF THE DAY TODAY.
PREVIOUS THINKING WAS THE WARM FRONT WOULD SHOOT ON THROUGH...BUT NOW
LOOKS LIKE CLOUDS MAY HOLD OVER MUCH OF THE AREA THROUGH THE DAY.
THIS WILL LIKELY SUPPRESS TEMPERATURES. REGARDLESS...ADVECTION ALONE
SHOULD ALLOW TEMPERATURE TO CLIMB INTO THE LOW TO MID 60S. AREAS IN
THE SOUTHWEST HAVE A BETTER CHANCE OF CLEARING AND WE COULD SEE SOME
READINGS GETTING CLOSE TO 70. CLOUDS SHOULD CONTINUE ERODING INTO
TONIGHT...BUT SOUTHERLY WINDS ARE EXPECTED TO REMAIN IN TACT TONIGHT
WITH A GOOD GRADIENT. THIS WILL ALLOW OVERNIGHT LOWS TO REMAIN VERY
MILD WITH READINGS IN THE 50S (HIGHER THAN OUR AVERAGE HIGHS FOR THIS
TIME OF YEAR).
BY LATE TONIGHT...AND ESPECIALLY TOMORROW...ISENTROPIC ASCENT WILL
KICK INTO FULL GEAR WITH PRECIPITATION DEVELOPING ACROSS CENTRAL AND
EASTERN KENTUCKY. MODELS HAVE SLOWED DOWN THE ADVANCING COLD
FRONT...SO HAVE SLOWED DOWN PRECIPITATION CHANCES. IT DOES LOOK LIKE
PRECIPITATION SHOULD EASILY IMPACT THE I-75 CORRIDOR ON THURSDAY...BUT
RAIN MAY MAKE IT AS FAR AS FAR EASTERN KENTUCKY BY LATE IN THE DAY.
REGARDLESS...CONFIDENCE IS NOT AS HIGH IN THE EAST...SO HAVE GONE
WITH AN EAST TO WEST GRADIENT IN POPS. INITIAL RAINFALL TOTALS ON
THURSDAY ARE NOT EXPECTED TO BE TOO HIGH GIVEN THE INITIAL DRY AIR
TO OVERCOME. HOWEVER...SOME TOTALS NEAR A HALF INCH MAY BE POSSIBLE
NEAR THE I-75 CORRIDOR BY LATE IN THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 440 AM EST WED DEC 4 2013
EXCESSIVE RAINFALL STILL LOOKS ON TRACK THROUGH EARLY NEXT
WEEK...ALTHOUGH MODEL GUIDANCE HAS TRENDED A BIT LEANER WITH THE
FIRST BATCH OF RAINFALL...WITH 2 TO 2.5 INCHES OF RAIN SUGGESTED
NOW...AND THEN SIMILAR TOTALS OCCURRING FROM SUNDAY THROUGH MONDAY.
THIS WOULD YIELD 4 DAY TOTALS IN THE 4 TO 5 INCH RANGE...WITH LARGER
CREEKS...STREAMS...AND RIVERS SEEING THE BEST CHANCE OF FLOODING
GIVEN THE LONG DURATION OF THE PRECIPITATION. WILL CONTINUE TO
HIGHLIGHT THESE CONCERNS IN AN ONGOING HYDROLOGIC OUTLOOK.
THE COLD FRONT WILL HAVE SETTLED JUST OFF TO THE SOUTHEAST OF OUR
AREA THURSDAY NIGHT. IT WILL CONTINUE TO SAG SOUTHEAST AND PIVOT A
BIT MORE AS SURFACE WAVES TRAVERSE THE BOUNDARY. THE RAIN MAY FALL
HEAVY AT TIMES THURSDAY NIGHT AND PARTICULARLY FRIDAY AS THE
STRONGEST UPPER LEVEL JET MOVES THROUGH THE GREAT LAKES AND LEAVES
MUCH OF THE OHIO VALLEY IN A FAVORABLE RIGHT ENTRANCE REGION.
SOME LIGHT SLUSHY ACCUMULATION STILL LOOKS LIKE A POSSIBILITY
GENERALLY ALONG AND NORTH OF THE MOUNTAIN PARKWAY. THE COLD AIR
ADVECTION HAS TRENDED A BIT QUICKER...SO THERE MAY BE A 1 TO 2 HOUR
WINDOW OF DECENT ENOUGH SNOWFALL RATES TO OVERCOME THE WARM GROUND
TEMPERATURES TEMPORARILY HEADING INTO DUSK. WILL AWAIT FURTHER MODEL
CONSISTENCY BEFORE DRAWING MORE ATTENTION TO THIS POTENTIAL AS IMPACT
OVERALL STILL LOOKS ON THE LOW SIDE.
PRECIPITATION WILL TAPER OFF QUICKLY FRIDAY NIGHT FROM NORTHWEST TO
SOUTHEAST AS COLDER AND MUCH DRIER AIR ADVECT IN FROM HIGH PRESSURE
SETTLING IN ACROSS THE PLAINS. DRY AND MUCH COLDER WEATHER IS
EXPECTED FOR SATURDAY...WITH HIGHS RANGING FROM THE LOWER 30S NORTH
OF I-64...TO THE LOWER 40S BORDERING TENNESSEE.
THE NEXT PRECIPITATION EVENT WILL THEN THREATEN EASTERN KENTUCKY BY
SATURDAY NIGHT...AS AN INVERTED SURFACE TROUGH BECOMES RE-ESTABLISHED
ACROSS THE LOWER MISSISSIPPI VALLEY. THE PRECIPITATION WILL BEGIN AS
SNOW ESPECIALLY NORTH OF THE HAL ROGERS PARKWAY AND HIGHWAY 80
CORRIDORS...HOWEVER THE WARM NOSE LOOKS TO OVERWHELM THE COLD AIR
QUICKLY...SO IT LOOKS TO BE ANOTHER MORE LIMITED WINDOW OF SNOW AND
POSSIBLY AN ALTERNATIVE TYPE OF PRECIPITATION DEPENDING ON HOW COLD
IT CAN GET SATURDAY NIGHT AND THE FURTHER EVOLUTION OF THE SYSTEM.
EXPECT A TRANSITION TO ALL RAIN THROUGH SUNDAY...AS A MORE ROBUST
SURFACE WAVE DEVELOPS ALONG THE BOUNDARY IN THE GULF AND HEADS
NORTHEAST. THIS SURFACE LOW WILL CONTINUE TO DEEPEN AS IT HEADS INTO
THE GREAT LAKES BY MONDAY. THE HEAVIEST RAIN LOOKS TO FALL ACROSS
EASTERN KENTUCKY SUNDAY NIGHT INTO MONDAY AS UPPER LEVEL DYNAMICS ARE
MAXIMIZED ONCE AGAIN ACROSS THE OHIO VALLEY. MUCH COLDER AIR WILL
MOVE IN BEHIND THE COLD FRONT...ONCE IT GETS DRAGGED TOWARDS THE
EASTERN SEABOARD LATE MONDAY. EXPECT SOME BACKSIDE SNOW ONCE
AGAIN...HOWEVER WITH DEEPER MOISTURE EXITING...AM ONLY SEEING LIGHT
ACCUMULATIONS RIGHT NOW. TUESDAY HIGHS WILL STRUGGLE TO REACH THE
FREEZING MARK AT MOST LOCATIONS...WITH DRY WEATHER RETURNING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 651 AM EST WED DEC 4 2013
MVFR CIGS WILL CONTINUE THROUGH MUCH OF THE MORNING BEFORE LIFTING
BACK TO VFR THIS AFTERNOON. WITH THE WARM FRONT PUNCHING THROUGH THE
AREA LATE IN THE DAY...CLOUDS SHOULD GIVE WAY TO ONLY SOME MID/HIGH
CLOUDS FOR THE OVERNIGHT HOURS. A COLD FRONT WILL PUSH TOWARDS THE
AREA BY LATE IN THE PERIOD...BUT CLOUDS SHOULD REMAIN VFR THROUGH
18Z. THE POSSIBILITY OF SOME LOW LEVEL WIND SHEAR WILL BEGIN BY LATE
IN THE DAY CONTINUING THROUGH TONIGHT...BUT NOT CONFIDENT ON HOW
MIXED THE SURFACE WILL BE TO INCLUDE IN THE TAF AT THE MOMENT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...KAS
LONG TERM...GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
526 AM CST WED DEC 4 2013
.AVIATION...12Z TAFS FOR KOMA...KLNK AND KOFK. FREEZING DRIZZLE
WILL BE THE PRIMARY CONCERN AT KLNK/KOMA THROUGH ABOUT
15-16Z...WITH IFR CONDITIONS EXPECTED. FURTHER NORTH AT
KOFK...MVFR CLOUDS WILL PERSIST...AND STILL COULD SEE A FEW SNOW
SHOWERS OR FLURRIES AT THAT LOCATION. OTHERWISE...MVFR CLOUDS
COULD PERSIST THROUGH THE PERIOD...WITH NORTHWEST WINDS AT 20 TO
30 MPH.
DEWALD
&&
.PREV DISCUSSION... /ISSUED 305 AM CST WED DEC 4 2013/
DISCUSSION...
LOW PRESSURE WAS LOCATED OVER NORTH CENTRAL OKLAHOMA AT 08Z
WITH A STATIONARY FRONT STRETCHING ACROSS EASTERN KANSAS INTO
CENTRAL IOWA. RADAR SHOWS PRIMARY BAND OF SNOW EXTENDS FROM NORTH
CENTRAL NEBRASKA INTO SOUTHEAST SOUTH DAKOTA AND SOUTHWEST
MINNESOTA...WHILE WIDESPREAD FOG AND DRIZZLE WAS LOCATED ALONG
THE STATIONARY FRONT. SOME LIGHT SNOW STILL LIKELY FOR NORTHEAST
BORDER AREA THIS MORNING AS SYSTEM LIFTS NORTHEAST WITH UP TO
AN INCH POSSIBLE BEFORE ENDING THIS AFTERNOON.
FREEZING DRIZZLE HAS STARTED TO BECOME MORE WIDESPREAD IN EASTERN
NEBRASKA AS THE COLDER AIR PUSHES INTO THE AREA. RAP FORECAST
SOUNDINGS SUGGEST THE POTENTIAL FOR FREEZING DRIZZLE THROUGH MOST
OF THE MORNING FOR SOUTHEAST NEBRASKA AND SOUTHWEST IOWA BEFORE
SOMEWHAT DRIER AIR WORKS INTO THE LOW LEVELS. WILL PROBABLY WAIT
UNTIL JUST BEFORE ISSUANCE TO BETTER ASSES EXTENT OF THE PRECIP
BUT ADVISORY SEEMS LIKELY AT SOME POINT.
STRONG COLD ADVECTION FINALLY ARRIVES DURING THE AFTERNOON AS AREA
COMES ON THE BACK SIDE OF THE DEPARTING SYSTEM. FOR THE REMAINDER
OF THE SHORT TERM TEMPERATURES BECOME THE PRIMARY FORECAST CONCERN
WITH VERY COLD WIND CHILLS DEVELOPING ESPECIALLY IN THE NORTH HALF
OF THE AREA.
LITTLE CHANGE IN THE EXTENDED PERIOD WITH STILL SOME CHANCE OF
SNOW LATE SATURDAY INTO SUNDAY WITH COLD TEMPERATURES CONTINUING.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ034-
044-045-050>053-065>068-078-088>090-092.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ091-093.
IA...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ043-
055-056-069-079.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ080-090-091.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
841 AM CST Wed Dec 4 2013
.UPDATE...
Updated temperatures and winds across the northern Big Country.
&&
.DISCUSSION...
Initial cold front has dropped into the northern Big Country
counties of Haskell and Throckmorton. Latest RUC and NAM data
suggests that the temperatures behind the front will still climb
today, but just not as fast. Have lowered afternoon highs and
adjusted temperatures and winds for the rest of the day.
Models suggest the front will approach Abilene this afternoon and
then stall. Will not bring it in at this point, but will continue to
monitor.
&&
.PREV DISCUSSION... /ISSUED 558 AM CST WED DEC 4 2013/
AVIATION...
/12Z TAFS/
Expect VFR conditions at the terminals during the next 24 hours as
high clouds stream northeast across West Central Texas. The winds
will be southwest to west with gusts to near 20 knots this
afternoon. Also, a cold front will move to just south of the I-20
corridor by late tonight, and have shifted the wind to the north at
the KABI terminal after 06Z Thursday.
21
PREV DISCUSSION... /ISSUED 510 AM CST WED DEC 4 2013/
SHORT TERM...
Today
Look for one more day of unseasonably warm afternoon highs.
Temperatures at 850 mb increase again this afternoon across West
Central Texas. Although cloud cover will be increasing today, gusty
west, down-slope, winds will help push afternoon highs into the mid
to upper 70s across the Big Country and into the 80 to 85 range
elsewhere.
Huber
Tonight
Another strong cold front will move into the Big country around
midnight tonight. The NAM continues to be faster than the GFS. Our
wind grids reflect a timing closer to the faster NAM; thus, I expect
north surface winds to dominate the Big Country north of Interstate
20 by midnight tonight. Thus, lows there tonight will be mainly in
the 30 to 35 range. Elsewhere, 40s look good.
Huber
Thursday through Friday night
Unseasonably cold temperatures and a wintry precipitation mix will
dominate the remainder of the short term. Well, we`ve closely
watched the models develop this next arctic system for the last
several days, and we`re becoming more confident with accumulations
of sleet or freezing rain which may exceed our one quarter inch
warning threshold, mainly across the Big Country. I did note model
forecast sounding are indicating much deeper saturation in the
column, as compared to this time last night. So, with greater
confidence for significant accumulation, we have a Winter Storm
Watch in effect for all our Big Country counties. The latest
Weather Prediction Center guidance indicates possible
accumulations across mainly our Big Country counties of at least
one quarter inch. Elsewhere across West Central Texas, my
confidence is not as high for any accumulations close to one
quarter inch. Thus, we will continue a Special Weather Statement
for our remaining counties. The best chance for precipitation will
be Thursday night, as an upper trough moves over the region. As if
the ice and sleet accumulations weren`t enough, I`m also concerned
about temperatures Thursday night and corresponding wind chill,
especially across the Big Country. With lows in the teens there,
gusty north winds will create very dangerous wind chill numbers
around zero degrees. On Friday, strong cold air advection
continues, with surface winds from the north around 15 mph. The
wintry precipitation mix will continue until around noon; then,
the upper trough axis moves east of our area. Overnight Friday
night, very dangerous wind chill numbers will again dominate the
Big Country and even parts of the Concho valley and Heartland.
With north surface winds continuing Friday night, cold air
advection will create colder lows than Thursday night.
Huber
LONG TERM...
Saturday through Sunday
Unseasonably cold temperatures will continue through the weekend. As
a very dominate arctic airmass settles over Texas for the weekend,
unseasonably cold temperatures will continue. Highs Saturday will
likely remain at or just below freezing for most of West Central
Texas. Thus, any remaining ice will likely be slow to melt, if it
melts at all. Another short wave aloft will move across the southern
plains on Saturday and perhaps bring another brief round of wintry
precipitation to West central Texas. My confidence isn`t very high
regarding the potential for additional precipitation with this
secondary short wave; thus, I`ve continued only slight chance PoPs
for the Saturday period. As for temperatures, Sunday doesn`t look
much better. Returning sunshine Sunday will help lift temperatures
above the freezing mark for the afternoon hours. Nevertheless, highs
in the lower 30s for much of the Big Country on Sunday aren`t what
I`d call warm!
Huber
Sunday night through Tuesday
For the start of next week, temperatures do begin to rebound just
slightly; but, they remain well below seasonal normals.
Huber
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 76 34 34 17 28 / 5 30 60 70 30
San Angelo 82 44 44 25 33 / 5 20 50 70 20
Junction 84 49 49 31 35 / 10 20 40 70 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from Thursday afternoon through Friday
morning FOR THE FOLLOWING ZONES: Callahan...Fisher...Haskell...
Jones...Nolan...Shackelford...Taylor...Throckmorton.
&&
$$
07
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
556 AM CST WED DEC 4 2013
.AVIATION...
FOR THE 12Z TAFS, THIS IS A LOW CONFIDENCE FORECAST.
A COLD FRONT HAS PASSED THROUGH ALL THE TERMINALS WITH N/NE WINDS
LIKELY TO CONTINUE THROUGH THE REMAINDER OF THIS TAF PERIOD. A
SECONDARY COLD FRONT WILL ARRIVE 00Z-03Z WITH NE WINDS GUSTING UP TO
25 KT.
THE MOST PROBLEMATIC ASPECT OF THIS FORECAST IS FLIGHT CATEGORIES,
AND FORECAST CONFIDENCE IS VERY LOW.
LLWS ASSOCIATED WITH THE COLD FRONT WILL CONTINUE AT KAMA AND KDHT
THROUGH 16Z WHEN WINDS WEAKEN ALOFT. DESPITE THE WEAKENING WINDS
ALOFT, THERE WILL STILL BE AT LEAST A 150 DEGREE WIND SHIFT WITHIN
THE LOWEST 2000 FT THROUGHOUT THIS TAF PERIOD.
-SN WILL BE POSSIBLE AT KDHT AND KGUY AFTER 09Z, BUT DRY AIR NEAR
THE SURFACE MAY ALLOW THIS TO HOLD OFF UNTIL AFTER THIS TAF PERIOD.
JACKSON
&&
.PREV DISCUSSION... /ISSUED 534 AM CST WED DEC 4 2013/
DISCUSSION...
THE ANTICIPATED COLD FRONT IS CURRENTLY WORKING SOUTH THROUGH THE
FORECAST AREA...WITH AN EXPECTED SURGE OF ARCTIC AIR LATER TODAY
PLUNGING THE PANHANDLES INTO SUBFREEZING TEMPERATURES THROUGH AT
LEAST THE WEEKEND. A PERIOD OF SNOWFALL WILL BE POSSIBLE FROM LATE
TONIGHT THROUGH EARLY FRIDAY MORNING. FURTHER CHANCES FOR LIGHT SNOW
MAY RETURN LATE IN THE WEEKEND.
SHORT TERM...TODAY THROUGH FRIDAY MORNING...
EVEN AT THIS LATE HOUR...THERE CONTINUES TO BE MODEL DISAGREEMENT
OVER THE TIMING AND POSITION OF THE COLD FRONT TODAY. AT LEAST AN
INITIAL SURGE HAS PUSHED THE FRONT TO THE SOUTH OF OUR CWA THIS
MORNING. THE LATEST RAP CONTINUES TO INDICATE A SLIGHT RETREAT OF THE
FRONT THIS AFTERNOON...ALLOWING FOR THE FAR SOUTHWEST TX PANHANDLE TO
WARM INTO THE UPPER 50S OR LOWER 60S. A FINAL SURGE OF COLD AIR
SHOULD PUSH THE FRONT SOUTH OF OUR AREA BY SUNSET TONIGHT. THEN...THE
ARCTIC AIR IS HERE TO STAY. NIGHTTIME LOWS IN THE LOW SINGLE DIGITS
TO MID TEENS...AND DAYTIME HIGHS IN THE TEENS TO 20S WILL BE POSSIBLE
FOLLOWING THE COLD FRONT.
LIGHT SNOW WILL BE POSSIBLE BEFORE MIDNIGHT TONIGHT IN THE WESTERN OK
PANHANDLE AND FAR NW TX PANHANDLE. ACCUMULATIONS OF SNOW SHOULD BE
MINIMAL FROM THIS FIRST ROUND. BY NOON THURSDAY...A MUCH MORE
PRONOUNCED FRONTOGENETIC BAND OF SNOW SHOULD SET UP ROUGHLY FROM
HARTLEY COUNTY TO TEXAS COUNTY. ALL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT ON THE PLACEMENT OF THIS BAND THROUGH TOMORROW AFTERNOON. A
POSSIBLE SECOND BAND SOUTHWARD SHIFT OF THE FIRST COULD BRING
INCREASED SNOW ACCUMULATIONS ALONG A LINE FROM VEGA TO BEAVER HEADING
INTO THE EVENING.
CURRENT THINKING HAS MOST SNOWFALL CLEARING FROM NORTHWEST TO
SOUTHEAST OVERNIGHT THURSDAY INTO FRIDAY...WITH THE LAST ACCUMULATING
SNOW FALLING IN THE SOUTHEAST TEXAS PANHANDLE BETWEEN MIDNIGHT FRIDAY
TO 6 AM THAT MORNING. SOME PERIODS OF FLURRIES COULD LINGER BEHIND
UNTIL DRIER MID LEVEL AIR FINALLY BUILDS OVER THE PANHANDLES.
OVERALL...WE ARE EXPECTING AVERAGE AMOUNTS OF 1 TO 3 INCHES OF SNOW
ACROSS THE PANHANDLES FROM TONIGHT THROUGH FRIDAY MORNING...WITH
LOCALLY HIGHER AMOUNTS UP TO 5 INCHES POSSIBLE UNDER HEAVIER SNOW
BANDS. A WINTER WEATHER ADVISORY WILL BE ISSUED TO ADDRESS THIS
SNOWFALL POTENTIAL.
NF
LONG TERM...FRIDAY THROUGH TUESDAY...
AS THE MAIN SHOT AT SNOW CLEARS THE AREA...THE MAIN STORY THROUGH THE
WEEKEND WILL BE THE PERSISTENT COLDER AIR IN PLACE THROUGH EARLY NEXT
WEEK. THINK NIGHTTIME LOWS IN THE LOW SINGLE DIGITS TO MID TEENS
WILL BE POSSIBLE MOST NIGHTS THROUGH THE MIDDLE OF NEXT WEEK...WITH
DAYTIME HIGHS IN THE TEENS AND TWENTIES THROUGH SATURDAY.
SOUTHWESTERLY WINDS ON SUNDAY MAY HELP TO BRING TEMPERATURES UP TO
NEAR FREEZING...THOUGH THINK CLOUD COVER WILL KEEP MOST PLACES BELOW
FREEZING EVEN ON SUNDAY AND MONDAY. CURRENTLY THINK TUESDAY WILL BE
FIRST CHANCE TO CLIMB ABOVE THE FREEZING MARK. DANGEROUSLY COLD WIND
CHILLS BETWEEN ZERO AND 15 BELOW ZERO WILL BE POSSIBLE DURING THIS
TIME AS WELL.
CANNOT RULE OUT A SLIGHT CHANCE FOR LIGHT SNOW SATURDAY NIGHT INTO
SUNDAY...THOUGH AT THIS TIME THINK ANY ACCUMULATIONS WOULD BE LESS
THAN ONE HALF INCH.
NF
FIRE WEATHER...
ONLY A BRIEF PERIOD OF ELEVATED FIRE WEATHER CONDITIONS WILL BE
POSSIBLE THIS AFTERNOON IN THE FAR SOUTHWEST TEXAS PANHANDLE...SHOULD
THE COLD FRONT IN FACT RETREAT NORTHEAST DURING THE DAY.
OTHERWISE...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE
EXPECTED THROUGH THE MIDDLE OF NEXT WEEK.
NF
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
NF/JJ
AREA FORECAST DISCUSSION
NWS AMARILLO TX
534 AM CST WED DEC 4 2013
.DISCUSSION...
THE ANTICIPATED COLD FRONT IS CURRENTLY WORKING SOUTH THROUGH THE
FORECAST AREA...WITH AN EXPECTED SURGE OF ARCTIC AIR LATER TODAY
PLUNGING THE PANHANDLES INTO SUBFREEZING TEMPERATURES THROUGH AT
LEAST THE WEEKEND. A PERIOD OF SNOWFALL WILL BE POSSIBLE FROM LATE
TONIGHT THROUGH EARLY FRIDAY MORNING. FURTHER CHANCES FOR LIGHT SNOW
MAY RETURN LATE IN THE WEEKEND.
&&
.SHORT TERM...TODAY THROUGH FRIDAY MORNING...
EVEN AT THIS LATE HOUR...THERE CONTINUES TO BE MODEL DISAGREEMENT
OVER THE TIMING AND POSITION OF THE COLD FRONT TODAY. AT LEAST AN
INITIAL SURGE HAS PUSHED THE FRONT TO THE SOUTH OF OUR CWA THIS
MORNING. THE LATEST RAP CONTINUES TO INDICATE A SLIGHT RETREAT OF THE
FRONT THIS AFTERNOON...ALLOWING FOR THE FAR SOUTHWEST TX PANHANDLE TO
WARM INTO THE UPPER 50S OR LOWER 60S. A FINAL SURGE OF COLD AIR
SHOULD PUSH THE FRONT SOUTH OF OUR AREA BY SUNSET TONIGHT. THEN...THE
ARCTIC AIR IS HERE TO STAY. NIGHTTIME LOWS IN THE LOW SINGLE DIGITS
TO MID TEENS...AND DAYTIME HIGHS IN THE TEENS TO 20S WILL BE POSSIBLE
FOLLOWING THE COLD FRONT.
LIGHT SNOW WILL BE POSSIBLE BEFORE MIDNIGHT TONIGHT IN THE WESTERN OK
PANHANDLE AND FAR NW TX PANHANDLE. ACCUMULATIONS OF SNOW SHOULD BE
MINIMAL FROM THIS FIRST ROUND. BY NOON THURSDAY...A MUCH MORE
PRONOUNCED FRONTOGENETIC BAND OF SNOW SHOULD SET UP ROUGHLY FROM
HARTLEY COUNTY TO TEXAS COUNTY. ALL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT ON THE PLACEMENT OF THIS BAND THROUGH TOMORROW AFTERNOON. A
POSSIBLE SECOND BAND SOUTHWARD SHIFT OF THE FIRST COULD BRING
INCREASED SNOW ACCUMULATIONS ALONG A LINE FROM VEGA TO BEAVER HEADING
INTO THE EVENING.
CURRENT THINKING HAS MOST SNOWFALL CLEARING FROM NORTHWEST TO
SOUTHEAST OVERNIGHT THURSDAY INTO FRIDAY...WITH THE LAST ACCUMULATING
SNOW FALLING IN THE SOUTHEAST TEXAS PANHANDLE BETWEEN MIDNIGHT FRIDAY
TO 6 AM THAT MORNING. SOME PERIODS OF FLURRIES COULD LINGER BEHIND
UNTIL DRIER MID LEVEL AIR FINALLY BUILDS OVER THE PANHANDLES.
OVERALL...WE ARE EXPECTING AVERAGE AMOUNTS OF 1 TO 3 INCHES OF SNOW
ACROSS THE PANHANDLES FROM TONIGHT THROUGH FRIDAY MORNING...WITH
LOCALLY HIGHER AMOUNTS UP TO 5 INCHES POSSIBLE UNDER HEAVIER SNOW
BANDS. A WINTER WEATHER ADVISORY WILL BE ISSUED TO ADDRESS THIS
SNOWFALL POTENTIAL.
NF
.LONG TERM...FRIDAY THROUGH TUESDAY...
AS THE MAIN SHOT AT SNOW CLEARS THE AREA...THE MAIN STORY THROUGH THE
WEEKEND WILL BE THE PERSISTENT COLDER AIR IN PLACE THROUGH EARLY NEXT
WEEK. THINK NIGHTTIME LOWS IN THE LOW SINGLE DIGITS TO MID TEENS
WILL BE POSSIBLE MOST NIGHTS THROUGH THE MIDDLE OF NEXT WEEK...WITH
DAYTIME HIGHS IN THE TEENS AND TWENTIES THROUGH SATURDAY.
SOUTHWESTERLY WINDS ON SUNDAY MAY HELP TO BRING TEMPERATURES UP TO
NEAR FREEZING...THOUGH THINK CLOUD COVER WILL KEEP MOST PLACES BELOW
FREEZING EVEN ON SUNDAY AND MONDAY. CURRENTLY THINK TUESDAY WILL BE
FIRST CHANCE TO CLIMB ABOVE THE FREEZING MARK. DANGEROUSLY COLD WIND
CHILLS BETWEEN ZERO AND 15 BELOW ZERO WILL BE POSSIBLE DURING THIS
TIME AS WELL.
CANNOT RULE OUT A SLIGHT CHANCE FOR LIGHT SNOW SATURDAY NIGHT INTO
SUNDAY...THOUGH AT THIS TIME THINK ANY ACCUMULATIONS WOULD BE LESS
THAN ONE HALF INCH.
NF
&&
.FIRE WEATHER...
ONLY A BRIEF PERIOD OF ELEVATED FIRE WEATHER CONDITIONS WILL BE
POSSIBLE THIS AFTERNOON IN THE FAR SOUTHWEST TEXAS PANHANDLE...SHOULD
THE COLD FRONT IN FACT RETREAT NORTHEAST DURING THE DAY.
OTHERWISE...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE
EXPECTED THROUGH THE MIDDLE OF NEXT WEEK.
NF
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 54 13 18 11 17 / 5 10 30 50 10
BEAVER OK 30 12 19 9 19 / 5 10 50 30 10
BOISE CITY OK 25 7 12 5 13 / 5 30 50 40 10
BORGER TX 35 13 19 12 18 / 5 10 30 60 10
BOYS RANCH TX 50 15 18 12 19 / 5 20 40 40 10
CANYON TX 65 15 20 11 19 / 5 10 20 50 10
CLARENDON TX 52 17 22 15 22 / 0 10 10 30 10
DALHART TX 30 9 14 7 15 / 5 20 60 40 10
GUYMON OK 28 10 15 9 15 / 5 20 60 30 10
HEREFORD TX 66 15 21 11 20 / 5 10 30 50 10
LIPSCOMB TX 32 12 21 11 21 / 0 10 20 60 10
PAMPA TX 39 13 19 11 19 / 5 10 20 60 10
SHAMROCK TX 48 17 24 15 24 / 0 10 10 30 10
WELLINGTON TX 52 20 25 17 24 / 0 10 10 30 10
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
13/06
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
615 AM CST WED DEC 4 2013
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 427 AM CST WED DEC 4 2013
FOCUS IS ON PCPN TYPES AND AMOUNTS TODAY...THEN FALLING
TEMPERATURES TONIGHT AND THU.
MODELS ARE IN BETTER AGREEMENT TONIGHT...USED A BLEND...LEANING A
BIT MORE ON ECMWF FOR THIS PERIOD. MADE EARLIER CHANGE TO
HEADLINES WITH ISSUANCE OF WINTER WEATHER ADVISORY FOR CENTRAL WI
AS TEMPERATURES NOT MOVING ABOVE FREEZING...ACTUALLY DROPPED. LIGHT
PCPN CONTINUES TO LIFT NORTH INTO CWA. CALLS TO PORTAGE AND WOOD
COUNTIES INDICATED ICING ISSUES ON ROADS. LOOKING FOR
TEMPERATURES TO MOVE ABOVE FREEZING MID MORNING.
RADAR MOSAIC SHOWING AREA OF SNOW MAKING BEELINE FOR NORTH CENTRAL
WI THIS MORNING WITH RAP BRINGING IT INTO CWA AROUND 6AM.
TEMPERATURE PROFILES SUGGEST MOSTLY SNOW OVER NORTHERN WI THROUGH
18Z...THEN START TO MIX...LIMITING SNOW TOTALS. STILL LOOKING FOR
5 TO 7 INCHES WESTERN AREAS OF VILAS...SO WILL KEEP WARNING AS IS. NO
CHANGES PLANNED FOR CURRENT HEADLINES. TO THE SOUTH...INCREASING
DEW POINTS OVER FRESH SNOW FROM PREVIOUS EVENING TO LEAD TO DENSE
FOG FORMATION...MAINLY EAST CENTRAL. MODELS A BIT FAST BRINGING
MOISTURE NORTH...SO PUSHED BACK TIMING IN GRIDS. WILL PLAY WATCH
AND SEE A BIT LONGER BEFORE ISSUING ANY HEADLINE GIVEN NUMBER OF
HEADLINES OUT RIGHT NOW.
STRONG COLD FRONT TO MOVE THROUGH TONIGHT...WITH WED MIN/THU MAX
AROUND 12Z THU. USED NON DIURNAL TREND FOR TEMPS FALLING THROUGH
THE DAY. APPARENT TEMPS ONLY IN SINGLE DIGITS ABOVE OR BELOW ZERO
FOR MUCH OF THU. BACKED OFF A BIT ON POPS FOR LAKE EFFECT SNOWS
FAR NORTH THU WITH WINDS TOO WESTERLY IN DIRECTION.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 427 AM CST WED DEC 4 2013
MDLS CONT TO ADVERTISE AN AMPLIFIED MEAN FLOW THAT CONSISTED OF AN
ALASKA UPR RDG...A DEEP POSITIVE-TILTED LONGWAVE TROF FROM NRN
CANADA TO THE SW CONUS AND UPR RIDGING FROM FLORIDA INTO THE WRN
ATLANTIC. THIS PATTERN TO HOLD STEADY THRU THE UPCOMING WEEKEND
BEFORE THE ALASKA RDG BREAKS DOWN AND THE UPR TROF SHIFTS INTO THE
CNTRL CONUS BY THE END OF THE FCST PERIOD. A DRY AND VERY COLD AIR
MASS TO DEVELOP OVER NE WI THRU SAT NGT BEFORE THE NEXT SYSTEM IN
THE SW FLOW ALOFT ARRIVES LATE SUNDAY INTO MON. ANOTHER SURGE OF
ARCTIC AIR TO THEN OVERSPREAD THE REGION FOR THE MIDDLE OF NEXT
WEEK WITH TEMPS 20 TO 30 DEGS BELOW NORMAL.
LARGE ARCTIC HI PRES TO EXTEND FROM BRITISH COLUMBIA SEWD INTO THE
NRN/CNTRL PLAINS THU NGT WITH AN EWD EXTENT REACHING INTO THE
GREAT LAKES. THIS WOULD BRING PARTLY CLOUDY SKIES AND UNSEASONABLY
COLD CONDITIONS TO NE WI WITH TEMPS DROPPING BELOW ZERO OVER NRN/
PARTS OF CNTRL WI...WHILE LAKESHORE AREAS DIP INTO THE UPR SINGLE
DIGITS. ADD IN A WEST WIND AT 10 TO 15 MPH AND WE ARE LOOKING AT
WIND CHILL VALUES RANGING FROM 5 BELOW TO 20 BELOW ZERO BY
DAYBREAK. WL NEED TO WATCH N-CNTRL WI FOR A POSSIBLE WIND CHILL
ADVY IF WINDS CAN REMAIN STRONG ENUF.
QUIET AND VERY COLD CONDITIONS CONT THRU FRI AS THE ARCTIC HI TO
DOMINATE THE MIDDLE OF THE COUNTRY. THIS SFC HI WL KEEP A SYSTEM
MOVING FROM THE DEEP SOUTH TO THE MID-ATLANTIC STATES ADN NOT HAVE
ANY IMPACT ON OUR WEATHER. MAX TEMPS WL NOT GET OUT OF THE SINGLE
DIGITS OVER N-CNTRL WI...WITH TEENS EXPECTED ELSEWHERE. THIS WOULD
BE ABOUT 15 DEGS BELOW NORMAL.
THE ERN FLANK OF THE ARCTIC HI EDGES INTO THE WRN GREAT LAKES
REGION FRI NGT WITH A SLIGHT DIMINISH IN WIND SPEEDS. 8H TEMPS TO
HOVER IN THE -18 TO -20C RANGE AND WITH SKY CONDITIONS OF MOSTLY
CLEAR TO PARTLY CLOUDY...TEMPS WL BE EVEN COLDER THAN THU NGT WITH
READINGS FLIRTING WITH DOUBLE DIGITS BELOW ZERO IN THE NORTH...NEAR
ZERO AROUND THE FOX VALLEY AND AROUND 5 ABOVE ZERO NEAR LAKE MI. WE
COULD AGAIN BE LOOKING AT POSSIBLE WIND CHILL ADVYS ACROSS PARTS OF
NE WI AS VALUES FALL BELOW THE -20 DEG THRESHOLD. THE ARCTIC HI IS
FCST TO STRETCH FROM THE NRN HI PLAINS THRU THE GREAT LAKES ON
SAT...THEREBY PROVIDING FOR ANOTHER MOSTLY SUNNY TO PARTLY CLOUDY
DAY WITH TEMPS WELL BELOW NORMAL. IN FACT...MAX TEMPS WL NOT GET
OUT OF THE SINGLE DIGITS OVER NRN AND CNTRL WI AND ONLY IN THE 10
TO 15 DEG RANGE FOR E-CNTRL WI. THESE VALUES WOULD BE AROUND 20
DEGS BELOW NORMAL.
ATTENTION THEN TURNS TOWARD THE CNTRL CONUS LATE IN THE WEEKEND
WHERE A SYSTEM IS PROGGED TO EJECT NEWD OUT OF THE MAIN LONGWAVE
TROF. CLOUDS TO ALREADY BEGIN TO INCREASE SAT NGT...BUT QUESTIONS
REMAIN AS TO HOW FAST MOISTURE WL BE ABLE TO OVERSPREAD WI WITH
THE INITIAL DRY AIR MASS IN PLACE. EVEN WITH A STEADY INCREASE IN
ISEN LIFT THRU THE DAY...BELIEVE IT WL TAKE MOST OF SUNDAY JUST TO
SATURATE...THUS HAVE KEPT POPS ON THE LOW SIDE WITH A SLIGHT UPTICK
IN TEMPS AS 8H TEMPS `WARM` TO AROUND -14C.
AS ONE WOULD EXPECT THIS FAR OUT...THE MDLS ARE TRYING TO ZERO IN
ON THE TRACK OF THE STRENGTHENING AREA OF LOW PRES WHICH WL LIFT
NE TOWARD/INTO THE GREAT LAKES SUNDAY NGT. THE EXACT TRACK WL BE
CRUCIAL WHETHER NE WI SEES JUST LIGHT SNOW OR AN APPRECIABLE
ACCUMULATION WARRANTING A HEADLINE. HAVE RAISED POPS INTO THE HI
CHC CATEGORY FOR CNTRL WI AND LIKELY FOR ERN WI BASED ON THE MDLS
MOVING THE SFC LOW TOWARD ERN SECTIONS OF THE GREAT LAKES. WL NEED
TO WATCH THIS SYSTEM IN THE COMING DAYS AS ANY CHANGE IN STORM
TRACK WOULD AFFECT ACCUMULATION NUMBERS. THE SNOW SHOULD END MON
MORNING AS THE SFC LOW QUICKLY LIFTS NE INTO SE CANADA. ANY
ADDITIONAL ACCUMULATIONS APPEAR TO BE MINOR AT THIS POINT. THE
OTHER STORY FOR MON WL BE THE ONSET OF THE NEXT ARCTIC SURGE AS 8H
TEMPS CRASH THRU THE DAY. TEMPS MAY EASILY BE STEADY OR SLOWLY
FALL WITH LATE DAY TEMPS ALREADY DOWN INTO THE SINGLE DIGITS AND
TEENS.
THE COLDER AIR OF THE WINTER SEASON TO THEN SWEEP ACROSS THE GREAT
LAKES REGION MON NGT INTO TUE WITH 8H TEMPS PLUMMETING TO AS LOW
AS -26C. TOO MUCH OF A WESTERLY COMPONENT TO THE WIND TO BRING
LAKE EFFECT SNOWS INTO NRN WI...THUS AT LEAST A DRY FCST IS
ANTICIPATED. EXACTLY HOW COLD WE GET WL BE DETERMINED BY THE
EXTENT OF THE SNOW COVER OVER THE FCST AREA. BY TUE MORNING...SUB-
ZERO TEMPS COULD COVER ALL BUT THE LAKESHORE AREAS WITH MAX TEMPS
ON TUE PERHAPS NOT GETTING ABOVE ZERO OVER N-CNTRL WI.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 544 AM CST WED DEC 4 2013
GENERALLY POOR FLIGHT CONDITIONS EXPECTED INTO THIS EVENING WITH
SNOW OR A WINTRY MIX NORTH AND FOG SOUTH. LIGHT FREEZING PCPN WILL
AFFECT CENTRAL TAF SITES THROUGH THE MORNING...THOUGH SURFACE
TEMPERATURES ARE EXPECTED TO CLIMB TO ABOVE FREEZING MID MORNING.
BRISK WESTERLY WINDS EXPECTED BEHIND SYSTEM THIS EVENING AND
OVERNIGHT...WITH VISBYS/CIGS IMPROVING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
WIZ010>012.
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ020-
021-030-031-035>037-045.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ018-019.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR WIZ005.
&&
$$
SHORT TERM.....TE
LONG TERM......KALLAS
AVIATION.......TE
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 427 AM CST WED DEC 4 2013
FOCUS IS ON PCPN TYPES AND AMOUNTS TODAY...THEN FALLING
TEMPERATURES TONIGHT AND THU.
MODELS ARE IN BETTER AGREEMENT TONIGHT...USED A BLEND...LEANING A
BIT MORE ON ECMWF FOR THIS PERIOD. MADE EARLIER CHANGE TO
HEADLINES WITH ISSUANCE OF WINTER WEATHER ADVISORY FOR CENTRAL WI
AS TEMPERATURES NOT MOVING ABOVE FREEZING...ACTUALLY DROPPED. LIGHT
PCPN CONTINUES TO LIFT NORTH INTO CWA. CALLS TO PORTAGE AND WOOD
COUNTIES INDICATED ICING ISSUES ON ROADS. LOOKING FOR
TEMPERATURES TO MOVE ABOVE FREEZING MID MORNING.
RADAR MOSAIC SHOWING AREA OF SNOW MAKING BEELINE FOR NORTH CENTRAL
WI THIS MORNING WITH RAP BRINGING IT INTO CWA AROUND 6AM.
TEMPERATURE PROFILES SUGGEST MOSTLY SNOW OVER NORTHERN WI THROUGH
18Z...THEN START TO MIX...LIMITING SNOW TOTALS. STILL LOOKING FOR
5 TO 7 INCHES WESTERN AREAS OF VILAS...SO WILL KEEP WARNING AS IS. NO
CHANGES PLANNED FOR CURRENT HEADLINES. TO THE SOUTH...INCREASING
DEW POINTS OVER FRESH SNOW FROM PREVIOUS EVENING TO LEAD TO DENSE
FOG FORMATION...MAINLY EAST CENTRAL. MODELS A BIT FAST BRINGING
MOISTURE NORTH...SO PUSHED BACK TIMING IN GRIDS. WILL PLAY WATCH
AND SEE A BIT LONGER BEFORE ISSUING ANY HEADLINE GIVEN NUMBER OF
HEADLINES OUT RIGHT NOW.
STRONG COLD FRONT TO MOVE THROUGH TONIGHT...WITH WED MIN/THU MAX
AROUND 12Z THU. USED NON DIURNAL TREND FOR TEMPS FALLING THROUGH
THE DAY. APPARENT TEMPS ONLY IN SINGLE DIGITS ABOVE OR BELOW ZERO
FOR MUCH OF THU. BACKED OFF A BIT ON POPS FOR LAKE EFFECT SNOWS
FAR NORTH THU WITH WINDS TOO WESTERLY IN DIRECTION.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 427 AM CST WED DEC 4 2013
MDLS CONT TO ADVERTISE AN AMPLIFIED MEAN FLOW THAT CONSISTED OF AN
ALASKA UPR RDG...A DEEP POSITIVE-TILTED LONGWAVE TROF FROM NRN
CANADA TO THE SW CONUS AND UPR RIDGING FROM FLORIDA INTO THE WRN
ATLANTIC. THIS PATTERN TO HOLD STEADY THRU THE UPCOMING WEEKEND
BEFORE THE ALASKA RDG BREAKS DOWN AND THE UPR TROF SHIFTS INTO THE
CNTRL CONUS BY THE END OF THE FCST PERIOD. A DRY AND VERY COLD AIR
MASS TO DEVELOP OVER NE WI THRU SAT NGT BEFORE THE NEXT SYSTEM IN
THE SW FLOW ALOFT ARRIVES LATE SUNDAY INTO MON. ANOTHER SURGE OF
ARCTIC AIR TO THEN OVERSPREAD THE REGION FOR THE MIDDLE OF NEXT
WEEK WITH TEMPS 20 TO 30 DEGS BELOW NORMAL.
LARGE ARCTIC HI PRES TO EXTEND FROM BRITISH COLUMBIA SEWD INTO THE
NRN/CNTRL PLAINS THU NGT WITH AN EWD EXTENT REACHING INTO THE
GREAT LAKES. THIS WOULD BRING PARTLY CLOUDY SKIES AND UNSEASONABLY
COLD CONDITIONS TO NE WI WITH TEMPS DROPPING BELOW ZERO OVER NRN/
PARTS OF CNTRL WI...WHILE LAKESHORE AREAS DIP INTO THE UPR SINGLE
DIGITS. ADD IN A WEST WIND AT 10 TO 15 MPH AND WE ARE LOOKING AT
WIND CHILL VALUES RANGING FROM 5 BELOW TO 20 BELOW ZERO BY
DAYBREAK. WL NEED TO WATCH N-CNTRL WI FOR A POSSIBLE WIND CHILL
ADVY IF WINDS CAN REMAIN STRONG ENUF.
QUIET AND VERY COLD CONDITIONS CONT THRU FRI AS THE ARCTIC HI TO
DOMINATE THE MIDDLE OF THE COUNTRY. THIS SFC HI WL KEEP A SYSTEM
MOVING FROM THE DEEP SOUTH TO THE MID-ATLANTIC STATES ADN NOT HAVE
ANY IMPACT ON OUR WEATHER. MAX TEMPS WL NOT GET OUT OF THE SINGLE
DIGITS OVER N-CNTRL WI...WITH TEENS EXPECTED ELSEWHERE. THIS WOULD
BE ABOUT 15 DEGS BELOW NORMAL.
THE ERN FLANK OF THE ARCTIC HI EDGES INTO THE WRN GREAT LAKES
REGION FRI NGT WITH A SLIGHT DIMINISH IN WIND SPEEDS. 8H TEMPS TO
HOVER IN THE -18 TO -20C RANGE AND WITH SKY CONDITIONS OF MOSTLY
CLEAR TO PARTLY CLOUDY...TEMPS WL BE EVEN COLDER THAN THU NGT WITH
READINGS FLIRTING WITH DOUBLE DIGITS BELOW ZERO IN THE NORTH...NEAR
ZERO AROUND THE FOX VALLEY AND AROUND 5 ABOVE ZERO NEAR LAKE MI. WE
COULD AGAIN BE LOOKING AT POSSIBLE WIND CHILL ADVYS ACROSS PARTS OF
NE WI AS VALUES FALL BELOW THE -20 DEG THRESHOLD. THE ARCTIC HI IS
FCST TO STRETCH FROM THE NRN HI PLAINS THRU THE GREAT LAKES ON
SAT...THEREBY PROVIDING FOR ANOTHER MOSTLY SUNNY TO PARTLY CLOUDY
DAY WITH TEMPS WELL BELOW NORMAL. IN FACT...MAX TEMPS WL NOT GET
OUT OF THE SINGLE DIGITS OVER NRN AND CNTRL WI AND ONLY IN THE 10
TO 15 DEG RANGE FOR E-CNTRL WI. THESE VALUES WOULD BE AROUND 20
DEGS BELOW NORMAL.
ATTENTION THEN TURNS TOWARD THE CNTRL CONUS LATE IN THE WEEKEND
WHERE A SYSTEM IS PROGGED TO EJECT NEWD OUT OF THE MAIN LONGWAVE
TROF. CLOUDS TO ALREADY BEGIN TO INCREASE SAT NGT...BUT QUESTIONS
REMAIN AS TO HOW FAST MOISTURE WL BE ABLE TO OVERSPREAD WI WITH
THE INITIAL DRY AIR MASS IN PLACE. EVEN WITH A STEADY INCREASE IN
ISEN LIFT THRU THE DAY...BELIEVE IT WL TAKE MOST OF SUNDAY JUST TO
SATURATE...THUS HAVE KEPT POPS ON THE LOW SIDE WITH A SLIGHT UPTICK
IN TEMPS AS 8H TEMPS `WARM` TO AROUND -14C.
AS ONE WOULD EXPECT THIS FAR OUT...THE MDLS ARE TRYING TO ZERO IN
ON THE TRACK OF THE STRENGTHENING AREA OF LOW PRES WHICH WL LIFT
NE TOWARD/INTO THE GREAT LAKES SUNDAY NGT. THE EXACT TRACK WL BE
CRUCIAL WHETHER NE WI SEES JUST LIGHT SNOW OR AN APPRECIABLE
ACCUMULATION WARRANTING A HEADLINE. HAVE RAISED POPS INTO THE HI
CHC CATEGORY FOR CNTRL WI AND LIKELY FOR ERN WI BASED ON THE MDLS
MOVING THE SFC LOW TOWARD ERN SECTIONS OF THE GREAT LAKES. WL NEED
TO WATCH THIS SYSTEM IN THE COMING DAYS AS ANY CHANGE IN STORM
TRACK WOULD AFFECT ACCUMULATION NUMBERS. THE SNOW SHOULD END MON
MORNING AS THE SFC LOW QUICKLY LIFTS NE INTO SE CANADA. ANY
ADDITIONAL ACCUMULATIONS APPEAR TO BE MINOR AT THIS POINT. THE
OTHER STORY FOR MON WL BE THE ONSET OF THE NEXT ARCTIC SURGE AS 8H
TEMPS CRASH THRU THE DAY. TEMPS MAY EASILY BE STEADY OR SLOWLY
FALL WITH LATE DAY TEMPS ALREADY DOWN INTO THE SINGLE DIGITS AND
TEENS.
THE COLDER AIR OF THE WINTER SEASON TO THEN SWEEP ACROSS THE GREAT
LAKES REGION MON NGT INTO TUE WITH 8H TEMPS PLUMMETING TO AS LOW
AS -26C. TOO MUCH OF A WESTERLY COMPONENT TO THE WIND TO BRING
LAKE EFFECT SNOWS INTO NRN WI...THUS AT LEAST A DRY FCST IS
ANTICIPATED. EXACTLY HOW COLD WE GET WL BE DETERMINED BY THE
EXTENT OF THE SNOW COVER OVER THE FCST AREA. BY TUE MORNING...SUB-
ZERO TEMPS COULD COVER ALL BUT THE LAKESHORE AREAS WITH MAX TEMPS
ON TUE PERHAPS NOT GETTING ABOVE ZERO OVER N-CNTRL WI.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1040 PM CST TUE DEC 3 2013
GENERALLY POOR FLIGHT CONDITIONS WL PERSIST WITH MOIST ELY FLOW.
CONDITIONS IN MOST AREAS WON/T IMPROVE SIGNIFICANTLY UNTIL
TOMORROW EVENING...WHEN SYSTEM BEGINS TO LIFT OFF TO THE NE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
WIZ010>012.
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ020-
021-030-031-035>037-045.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ018-019.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR WIZ005.
&&
$$
SHORT TERM.....TE
LONG TERM......KALLAS
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS TUCSON AZ
256 PM MST WED DEC 4 2013
.SYNOPSIS...A STRONG STORM SYSTEM MOVING THROUGH THE WESTERN
UNITED STATES WILL BRING A CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW
TO SOUTHEAST ARIZONA THROUGH THURSDAY. THIS SYSTEM WILL ALSO BRING
IN MUCH COOLER TEMPERATURES...WITH WIDESPREAD FREEZING TEMPERATURES
ACROSS ALL OF SOUTHEAST ARIZONA FRIDAY MORNING. ANOTHER STORM SYSTEM
WILL BRING GUSTY WINDS...A CHANCE OF THE PRECIPITATION AND A
REINFORCEMENT OF COLDER AIR LATE THIS WEEKEND.
&&
.DISCUSSION...THE UPPER PATTERN IS DEFINED BY A HIGH AMPLITUDE UPPER
RIDGE IN THE EASTERN PACIFIC...AND A LONGWAVE TROUGH ACROSS THE
WESTERN STATES. SHORTWAVE ENERGY MOVING SOUTH ALONG THE CALIFORNIA
COAST WILL ROTATE INTO THE SOUTHERN EDGE OF THIS TROUGH BEFORE IT
TRACKS ACROSS THE AREA TONIGHT AND THURSDAY. THE TIGHT GRADIENT OUT
AHEAD OF THIS TROUGH HAS RESULTED IN BREEZY TO WINDY CONDITIONS...
ESPECIALLY TO THE EAST AND SOUTH OF TUCSON. SURFACE OBSERVATIONS IN
KDUG INDICATE SUSTAINED WINDS IN THE 25 TO 30 MPH RANGE WITH GUSTS
TO 45 MPH. A WIND ADVISORY IS IN EFFECT TO THE EAST UNTIL 8 PM MST
THIS EVENING. THE LATEST MODEL GUIDANCE STILL INDICATES 45 KT FLOW
ACROSS COCHISE AT 06Z TONIGHT. THIS USUALLY MEANS THAT LOCALIZED
AREAS NEAR THE HUACHUCA MOUNTAINS WILL CONTINUE TO EXPERIENCE STRONG
AND GUSTY WINDS WELL INTO THE OVERNIGHT HOURS.
ACCORDING TO THE LATEST SURFACE OBSERVATIONS...THE SOUTHERN TIP OF
THE SURFACE COLD FRONT ASSOCIATED WITH THIS SYSTEM IS CURRENTLY
POSITIONED ACROSS CENTRAL PIMA COUNTY EXTENDING INTO NW PINAL
COUNTY. AT 230 PM MST...KEMX RADAR JUST BEGINNING TO INDICATE SHOWERS
DEVELOPING ACROSS THE TOHONO OODHAM NATION. THE HRRR AND UNIVERSITY
OF ARIZONA WRF MODELS INDICATE THAT THE COLD FRONT WILL PUSH WEST
INTO TUCSON BY 5 PM THIS AFTERNOON WITH PCPN BEGINNING TO EXPAND AND
ENHANCE AS IT MOVES FARTHER EAST. EXPECT SHOWERS TO BECOME MORE
NUMEROUS THIS EVENING WITH THE MAJORITY OF THE PCPN AFFECTING THE
CWA OVERNIGHT INTO THURSDAY MORNING. MOISTURE SOMEWHAT LIMITED WITH
THIS SYSTEM AND STILL EXPECT ONLY A TENTH TO A THIRD INCH WITH MAYBE
A HALF INCH IN THE MOUNTAINS. THIS TRANSLATES INTO SNOWFALL AMOUNTS
JUST BELOW ADVISORY CRITERIA. IT IS POSSIBLE THAT SOME OF THE
HIGHEST PEAKS MAY BARELY HIT LOW END SNOW ADVISORY CRITERIA...BUT IT
WILL NOT BE WIDESPREAD ENOUGH TO WARRANT AN ADVISORY.
THE MAIN ISSUE WITH THIS SYSTEM IS NOT THE WIND OR THE PCPN...BUT
THE TEMPERATURES. COLD AIRMASS MAKING ITS WAY SOUTH WILL BRING THE
FIRST WIDESPREAD FREEZING TEMPERATURES TO THE LOWER DESERTS FROM
TUCSON WEST. HAVE DECIDED TO ISSUE A FREEZE WARNING FOR FRIDAY
MORNING TO GET THE WORD OUT TO PROTECT PEOPLE...PETS...PIPES AND
PLANTS.
ANOTHER STRONG WEATHER SYSTEM WILL MAKE ITS WAY SOUTH INTO ARIZONA
THIS WEEKEND. THE ECMWF IS MUCH COLDER AND THUS MORE AGGRESSIVE THAN
THE GFS BRINGING PCPN AND ANOMALOUSLY COLDER TEMPS. INCREASED POPS AND
LOWERED TEMPS SAT NIGHT INTO MONDAY TO REFLECT THIS TREND.
&&
.AVIATION...VALID THRU 06/00Z.
UPPER LEVEL JET MOVING ACROSS SOUTHEAST ARIZONA AND INTO NEW MEXICO
BY THURSDAY NOON. ASSOCIATED WITH THIS CHANGE...COLD AIR WILL ADVECT
INTO SOUTHERN ARIZONA TONIGHT AND THURSDAY. STRONG SURFACE WINDS OF
20-25 KT WITH GUSTS UP TO 45 KTS SUBSIDING AROUND 05/06Z. FROM
05/00Z INTO THURSDAY MIDDAY EXPECT ISOLD TO SCT -SHRA. PERIODS OF
MVFR CONDITIONS WILL BE PRESENT IN THE STRONGER SHOWERS. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...LOW PRESSURE TROUGH OVER THE WEST IS EXPECTED TO
REMAIN THROUGH THE FIRST PART OF NEXT WEEK. THE STRONG WINDS
ASSOCIATED WITH THIS TROUGH WILL SUBSIDE AROUND MIDNIGHT AND MUCH
COLDER AIR WILL ADVECT INTO THE AREA THURSDAY. TEMPERATURES WILL
DROP ABOUT 15 DEGREES BELOW AVERAGE LATE THURSDAY AND CONTINUE
THROUGH THE WEEKEND. MOISTURE WITH THIS TROUGH IS LIMITED...ALTHOUGH
MANY AREAS WILL SEE LIGHT PRECIPITATION AMOUNTS. A SECOND STORM
SYSTEM WILL DROP INTO THIS TROUGH LATE SATURDAY FOR A CHANCE OF
VALLEY RAIN AND MOUNTAIN SHOWERS...ALONG WITH REINFORCING THE COLDER
TEMPERATURES INTO EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM MST THIS EVENING FOR AZZ507>513.
FREEZE WARNING 10 PM MST THURSDAY NIGHT UNTIL 10 AM MST FRIDAY
MORNING FOR AZZ501>506.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS FLAGSTAFF AZ
915 AM MST WED DEC 04 2013
.SYNOPSIS...A COLD STORM SYSTEM WILL MOVE ACROSS ARIZONA TODAY...
BRINGING RAIN...SNOW...AND GUSTY WINDS. SNOW ACCUMULATIONS ARE
EXPECTED ABOVE 6000 FOOT LEVEL. A VERY COLD AIR MASS WILL SETTLE
ACROSS NORTHERN ARIZONA THROUGH THE REMAINDER OF THE WEEK...WITH HIGH
TEMPERATURES IN THE 20S AND 30S FOR MOST LOCATIONS. ANOTHER STORM
SYSTEM WILL BRING CHANCE OF SNOW TO THE AREA SATURDAY AND SUNDAY.
&&
.DISCUSSION...THE COLD FRONT CONTINUES TO MOVE ACROSS NRN AZ THIS
MORNING. NWS OFFICE NOTED A 7-DEGREE TEMP DROP IN 10 MINUTES AS THE
FRONT MOVED THRU AROUND 8 AM...AND LIGHT RAIN/SNOW SHOWERS RAPIDLY
INCREASED TO MODERATE AND STEADY SNOW WITH THE FRONTAL PASSAGE.
FARTHER NORTHWEST...SNOW WAS DIMINISHING IN COVERAGE AND INTENSITY.
WILL ALLOW ADVISORY OVER NWRN ZONES TO EXPIRE LATER THIS MORNING ON
SCHEDULE. WINTER WEATHER ADVISORY OVER THE MOGOLLON RIM THROUGH THIS
AFTERNOON REMAINS ON TRACK.
CURRENT HRRR PCPN FCST SHOWS THE FRONTAL BAND WILL CONTINUE TO BECOME
NARROWER THRU THE REMAINDER OF THE DAY SUCH THAT LOCATIONS FARTHER TO
THE EAST WILL SEE LESS PCPN OWING TO A SHORTER DURATION THAN AREAS TO
THE WEST. IN ADDITION...SATELLITE IR IMAGERY SHOWS THE COLDEST CLOUD
TOPS ARE SHIFTING TO THE NE AND OUT OF NRN AZ SO THIS WILL DIMINISH
THE SEEDER-FEEDER PROCESS RESULTING IN DECREASED PCPN EFFICIENCY.
STRONG AND GUSTY WINDS WILL CONTINUE ACROSS THE EASTERN PORTION OF
THE STATE AND A WIND ADVISORY REMAINS IN EFFECT THROUGH LATE THIS
AFTERNOON.
&&
.PREV DISCUSSION (400 AM)...TONIGHT THE FRONTAL BOUNDARY STALLS TO
OUR SOUTHEAST WITH THE WHITE MOUNTAINS HAVING THE BEST CHANCES FOR
SHOWERS. QPF AMOUNTS ARE LOW THOUGH AND SNOWFALL ACCUMULATIONS IN THE
WHITES ARE LESS THAN ADVISORY CRITERIA AND WILL KEEP THIS AREA OUT OF
A WINTER WX ADVISORY. CLEARING WEATHER TO MOVE IN FROM NW TO
SOUTHEAST TONIGHT AND REACH THE WHITE MTNS THURSDAY AFTERNOON.
VERY COLD AFTERNOON TEMPERATURES ARE IN STORE THROUGH SUNDAY...
AROUND 20 DEGREES BELOW NORMAL.
DRY WEATHER FOR ALL FROM THURSDAY EVENING THROUGH SUNRISE SATURDAY.
ANOTHER SYSTEM LOOMS FOR SATURDAY AND SUNDAY. CROSS SECTION FROM
ECMWF AND GFS SHOW DEEP SATURATION WITH THIS SYSTEM AND SHOULD THE
LATEST QPF PROGS VERIFY WE WOULD BE HAVING MORE SNOW ACCUMULATION
THAN TODAY. TIMING DETAILS ARE COMING TOGETHER AND CONFIDENCE
AND PRECIP CHANCES ARE RISING. STAY TUNED.
&&
.AVIATION...FOR THE 18Z PACKAGE... A POTENT COLD FRONT POSITIONED
ACROSS NORTH CENTRAL AZ THIS MORNING WILL MOVE SOUTHEAST TODAY
BRINGING WIDESPREAD IFR-MVFR CONDITIONS. SCT LIFR CONDITIONS CAN BE
EXPECTED IN THE MAIN FRONTAL PRECIPITATION BAND. SFC WINDS GENERALLY
SW15-25G35KT...ESPECIALLY ACROSS EASTERN AZ. SNOW LEVELS WILL REMAIN
ABOVE 6000 FEET AHEAD OF THE FRONT...LOWERING TO 3500-4500 FEET
BEHIND THE FRONT. AFTER 14/00Z...IMPROVING CONDITIONS SPREADING FROM
WEST TO EAST ACROSS WITH WINDS BECOMING LIGHT. AVIATION DISCUSSION
NOT UPDATED FOR AMENDMENTS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR AZZ013-014-016-
017.
WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR
AZZ004.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR
AZZ015-016.
&&
$$
PUBLIC.........DB/DL
AVIATION.......MCS
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
344 PM CST WED DEC 4 2013
.DISCUSSION...
340 PM CST
ACTIVE WEATHER PATTERN TO PERSIST INTO THE WEEKEND WITH FOG
PERSISTING AND SHOWERS THIS EVENING...MUCH COLDER AIR AND LIGHT
SNOW POSSIBLE FOR THE SOUTHEAST CWA THURSDAY NIGHT INTO
FRIDAY...AS WELL AS ANOTHER SYSTEM TO MOVE ACROSS THE AREA LATE
THIS WEEKEND INTO EARLY NEXT WEEK.
IN THE NEAR TERM...THE CWA REMAINS IN THE WARM SECTOR AS LOW
PRESSURE TO THE WEST CONTINUES TO LIFT NORTH/NORTHEAST ACROSS THE
REGION. IN THIS MUCH WARMER AIRMASS...WELL ABOVE NORMAL TEMPS IN
THE 50S HAVE SETTLED IN FOR MOST AREAS WITH HIGH DEWPOINT AIR
STILL STREAMING NORTH ACROSS THE REGION. DUE TO THIS WARM AND
MOIST AIRMASS...AREAS OF FOG AND DENSE FOG PERSIST AT THIS HOUR.
ALTHOUGH THERE HAS BEEN SOME IMPROVEMENT OVER THE LAST SEVERAL
HOURS...THIS IMPROVEMENT HAS OCCURRED OUTSIDE OF THE ADVISORY
AREA. IN THE ADVISORY AREA...NORTH CENTRAL AND NORTHEAST
ILLINOIS...DENSE FOG WITH VISIBILITY AT A QUARTER OF A MILE OR
LESS IS STILL IN PLACE. THE MOST DENSE FOG APPEARS TO BE CLOSER TO
THE ILLINOIS/WISCONSIN BORDER...AS WELL AS FOR AREAS NEAR THE LAKE
WHERE BOTH LOCATIONS ARE OBSERVING VISIBILITY NEAR ZERO. ONCE
AGAIN...AM NOT EXPECTING ANY CHANGES WITH CONDITIONS OVER THE NEXT
2-3 HOURS WITH THE CURRENT ADVISORY/LOCATION VERY MUCH VALID AT
THIS TIME. OUTSIDE OF THIS ADVISORY...LOCATIONS COULD STILL
OBSERVE AREAS OF FOG WITH VISIBILITY DROPPING AS LOW AS 1-3 MILES.
ALL FOG/LOW VIS SHOULD IMPROVE AROUND THE 00Z TIME FRAME AS FROPA
OCCURS IN THE 00-03 TIME FRAME...AND WITH ANY DENSER FOG LINGERING
ACROSS THE ILLINOIS NEARSHORE TO BEGIN PUSHING TO THE
NORTH/NORTHEAST AS WINDS VEER TO THE SOUTHWEST AND WEST THIS
EVENING. WEAK LARGE SCALE LIFT OWING TO STRONG WAA AND SUBTLE WEAK
MID LEVEL FEATURES WILL CONTINUE TO AID IN LIGHT SHOWER
DEVELOPMENT...AND ESPECIALLY WITH FROPA THIS EVENING. ALTHOUGH
ANYTHING THAT FALLS SHOULD BE LIGHT AND MORE SPORADIC IN NATURE.
DUE TO THIS...HAVE LEFT LOW CHANCE POPS FOR THIS AFTERNOON AND
EARLY EVENING...WITH CHANCES FOR SHOWERS DIMINISHING AFTER 9 PM
TONIGHT. AFTER THE DEPARTURE OF THE FOG/SHOWERS THIS EVENING...A
MUCH COLDER AIRMASS WILL BEGIN WORKING ITS WAY EAST ACROSS THE
REGION AND RESULT IN LOW TEMPS IN THE MID-UPPER 20S AND LOW 30S
TONIGHT.
AFTER ABOVE NORMAL TEMPS TODAY...BELOW NORMAL TEMPS AROUND 30 CAN
BE EXPECTED FOR MOST AREAS ON THURSDAY AS THIS MUCH COLDER AIRMASS
CONTINUES TO PUSH SOUTHEAST ACROSS THE AREA THROUGH THE AFTERNOON.
EXPECT LITTLE IMPROVEMENT IN CLOUD COVER WITH SOME AREAS ACROSS
NORTHERN ILLINOIS TRYING TO BECOME MORE PARTLY CLOUDY/PARTLY SUNNY
ON THURSDAY. ALTHOUGH...BROAD SOUTHWEST FLOW ALOFT WILL ALLOW FOR
A CONTINUE STREAM OF SHORT WAVE TROUGHS TOMORROW AND EVEN INTO
FRIDAY. THESE FEATURES AS WELL AS RESULTANT LOW/MID LEVEL
BAROCLINIC ZONE WILL ALLOW FOR DEVELOPING PRECIP AXIS TO THE SOUTH
TO INCH ITS WAY CLOSER TO THE FAR SOUTHERN CWA. LATEST TRENDS WITH
MODEL GUIDANCE WOULD KEEP ANY PRECIP/SNOW JUST TO THE SOUTH OF THE
CWA...BUT WITH SOME GUIDANCE STILL HINTING THAT THE FAR NORTHERN
EXTENT OF THIS PRECIP COULD REACH OUR SOUTHERN TIERS OF THE CWA.
SO TRENDED TOWARDS LOWERING POPS THURSDAY NIGHT INTO
FRIDAY...MAINLY FOR AREAS SOUTH OF A LINE FROM GIBSON CITY IN
ILLINOIS NORTHEAST TO RENSSELAER IN INDIANA...BUT DID NOT
COMPLETELY REMOVE THEM. WITH THE COLUMN SUFFICIENTLY COLD NOW AT
THIS TIME...ANY PRECIP WOULD BE ALL SNOW. IF THIS DOES REACH THE
CWA...CURRENT THINKING/GRIDS WOULD SUGGEST AT MOST A HALF INCH TO
AN INCH OF POSSIBLE SNOWFALL. WELL BELOW NORMAL TEMPS AND QUIET
WEATHER WILL THEN BE OBSERVED FRIDAY NIGHT INTO SATURDAY
NIGHT...WITH STEERING FLOW LIKELY TO KEEP ANY LAKE EFFECT PRECIP
JUST OUTSIDE OF THE AREA. THEN CONTINUE TO MONITOR THE NEXT SYSTEM
TO MOVE THROUGH THE REGION...WHICH WOULD BE SUNDAY INTO MONDAY.
GUIDANCE APPEARS TO HAVE A FAIRLY DECENT HANDLE ON THIS SYSTEM AND
IF CURRENT TRENDS CONTINUE...MOST AREAS COULD OBSERVE ACCUMULATING
SNOWFALL WITH SEVERAL INCHES OF SNOWFALL POSSIBLE.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CEILINGS...CONTINUED PREVAILING LOW END IFR TEMPO LIFR INTO LATE
AFTERNOON-EARLY EVENING...THEN IMPROVEMENT TO MVFR FOR REST OF
NIGHT.
* VISIBILITY...PREVAILING IFR IMPROVING TO MVFR INTO LATE
AFTERNOON-EARLY EVENING...THEN TO VFR MID EVENING AND BEYOND.
* PATCHY -DZ/-RA BECOMING MORE WIDESPREAD FOR MID AFTERNOON TO
EARLY EVENING.
* WIND SHIFT WITH COLD FRONTAL PASSAGE THIS EVENING BRINGING
MODERATELY GUSTY WINDS INTO THU.
TRS
//DISCUSSION...UPDATED 18Z...
SURFACE LOW BECOMING BETTER ORGANIZED 50SM S OF MSP AT 17Z WITH
ELONGATED PRESSURE FALL CENTER FROM E MN ACROSS W CENTRAL AND N
WI... MI U.P. AND LAKE SUPERIOR. MODELS TAKE THIS LOW NNE TO FAR
E CENTRAL MN AT 21Z AND TO TO FAR SE MN BY 18Z THEN NE TO NW-N
CENTRAL WI BY 00Z.
SE-SSE LOW LEVEL WINDS ACROSS THE LOCAL AREA CONTINUE TO ADVECT
WARMER BUT ALSO HIGHER DEW POINT AIR WITH SURFACE DEW POINT
DEPRESSIONS OF 0-1 DEG F OVER ALL BUT EXTREME S PORTIONS OF IL
AND IN. CONTINUED FEED OF THIS LOW DEW POINT DEPRESSION AIR
EXPECTED TO MAINTAIN RESTRICTED VSBY AND LOW CEILINGS UNTIL THE
SURFACE WINDS VEER A BIT TO S-SSW LATE AFTERNOON-EARLY EVENING AS
THE LOW MOVES TO N WI. THIS SLIGHT W COMPONENT TO THE LOW LEVEL
FLOW STARTS TO ADVECT IN SOMEWHAT GREATER DEW POINT DEPRESSIONS
WHICH IS EXPECTED TO RESULT IN SOME INCREASE IN VISIBILITY AND
CEILING HEIGHT.
A FEW PATCHES OF -DZ/-RA CURRENTLY MOVING NE AND FAR N CENTRAL
IL. MODELS CONTINUE TO SHOW PERSISTENT AND GRADUALLY INCREASING
BUT STILL SOMEWHAT WEAK UVV DOWN INTO THE LOW LEVEL MOISTURE
THROUGH EARLY EVENING AS A MID LEVEL SHORT WAVE TROUGH ROTATES NE
OVER THE MID MS VALLEY. EXPECT CURRENT LOW COVERAGE LIGHT LIQUID
PRECIP TO BECOME SOMEWHAT BROADER BY MID AFTERNOON IN RESPONSE TO
STRENGTHENING LOW LEVEL ISENTROPIC LIFT.
WITH THE LOW PROGGED TO MOVE TO W LAKE SUPERIOR BY 06Z THE
TRAILING COLD FRONT IS EXPECTED TO PUSH W TO E ACROSS THE LOCAL
AREA EARLY-MID EVENING. STRONG COLD AIR ADVECTION AND PRESSURE
RISES WILL RESULT IN INCREASING AND MODERATELY GUSTY WINDS BEHIND
THE FRONT. CURRENTLY...UPSTREAM WINDS BEHIND THE FRONT ARE OUT OF
THE NW BUT WITH THE LOW MOVING NNE AND AWAY FROM THE AREA TONIGHT
EXPECT LOCAL WINDS TO BE WSW-W. SUBSIDENCE AND DRYING FOLLOWING
FROPA SHOULD ALLOW CEILINGS TO RISE TO MVFR AS CURRENT OBSERVED
FROM NE OK TO SE NEB.
ANOTHER SHORT WAVE TROUGH PROGGED TO BE EXTENDING FROM N CENTRAL
WI SW TO S CENTRAL IA AT 05.18Z BUT WITH NO MID LEVEL MOISTURE TO
WORK WITH AND THE CONTINUED DECREASE IN LOW LEVEL MOISTURE AM
ANTICIPATING NO PRECIP WITH THIS DISTURBANCE AND ONLY CIRRUS
CEILINGS BY SUNRISE THU.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
*MEDIUM CONFIDENCE IN CIG TRENDS.
*MEDIUM CONFIDENCE IN VSBY TRENDS.
*HIGH CONFIDENCE IN WINDS THROUGH PERIOD INCLUDING TIMING OF WSHFT
WITH FROPA +/- 2HR.
*HIGH CONFIDENCE IN -SHRA/-RA OCCURRING THIS AFTERNOON AND THEN NO
PRECIP TONIGHT.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH SATURDAY...VFR.
SUNDAY...CHC SNOW...WITH SNOW LIKELY SUNDAY NIGHT.
MONDAY...SLT CHC SNOW. MVFR POSSIBLE.
TUESDAY...PRIMARILY VFR.
BMD
&&
.MARINE...
157 PM CST
THE VERY ACTIVE WEATHER PATTERN FOR LAKE MICHIGAN WILL CONTINUE FOR
THE NEXT SEVERAL DAYS. A DEEPENING LOW PRESSURE SYSTEM IS LIFTING
NORTHEAST THROUGH THE MIDDLE MISSISSIPPI VALLEY. AN ASSOCIATED WARM
FRONT EXTENDS EAST ACROSS THE NORTHERN PORTIONS OF THE LAKE WITH
STRONG EAST FLOW OVER THE FAR NORTHERN PORTION OF THE LAKE WITH
MODEST SELY-SLY FLOW OVER THE REMAINDER. UNSEASONABLE WARM...MOIST
AIR HAS OVERSPREAD RELATIVELY COOLER LAKE WATER...LEADING TO AREAS
OF DENSE FOG OVER THE NEARSHORE AND OPEN WATERS. A DENSE FOG
ADVISORY WILL REMAIN IN EFFECT FOR MUCH OF LAKE MICHIGAN WHILE IT
REMAINS UNDER THE INFLUENCE OF THE WARM...MOIST GENERALLY SOUTHERLY
FLOW. AS THE LOW TRACKS THROUGH WISCONSIN AND ACROSS LAKE SUPERIOR
TONIGHT...IT WILL DEEPEN RAPIDLY AS A STRONG COLD FRONT SWEEPS
ACROSS THE LAKE. WINDS WILL QUICKLY SHIFT FROM SLY TO WLY/NWLY
USHERING IN MUCH COLDER AIR OVERNIGHT TONIGHT AND THROUGH THE DAY
TOMORROW. NOT ONLY WILL THE WIND SHIFT AND INFLUX OF COOLER...DRIER
AIR HELP DISSIPATE THE FOG...THE STRONGEST COLD ADVECTION WILL
COINCIDE WITH THE MOST RAPID DEEPENING OF THE PARENT LOW. WHILE SLY
WINDS WILL STRENGTHEN TO JUST UNDER GALE FORCE AHEAD OF THE FRONT...
WINDS ARE EXPECTED TO REACH 35 KT...TO POSSIBLY 40 KT...GALES OVER
THE NORTHERN PORTIONS OF THE LAKE WHERE PRESSURE RISES WILL BE
STRONGEST IN THE WAKE OF THE LOW AS IT CONTINUES TO THE NORTHEAST.
SO...WILL UPGRADE THE GALE WATCH TO A WARNING. THE PRESSURE
GRADIENT AND PRESSURE RISES OVER THE SOUTHERN PORTIONS OF THE LAKE
WILL NOT BE QUITE AS STRONG...WITH ANOTHER ARCTIC HIGH BUILDING OUT
OF SWRN CANADA AND INTO CENTRAL PLAINS TONIGHT. ALSO...A WEAK RIDGE
AXIS ASSOCIATED WITH THE ARCTIC HIGH WILL POKE OVER THE SOUTHERN
PORTIONS OF THE LAKE LATE TONIGHT AND TOMORROW...WHICH WILL ALSO
HELP KEEP WINDS BELOW GALE FORCE. HOWEVER...THE GRADIENT SHOULD BE
STRONG ENOUGH TO SUPPORT 20-30KT WINDS...SO WILL KEEP THE SMALL
CRAFT ADVISORY IN EFFECT FOR THE NEARSHORE WATERS. THERE WILL BE
ANOTHER POTENTIAL PERIOD OF GALES FOR FRIDAY NIGHT AND INTO SATURDAY
AS THE ARCTIC HIGH BUILDS ACROSS THE MIDDLE MISSISSIPPI VALLEY AND A
MID LEVEL IMPULSE DROPS OUT OF CANADA AND TRACKS ACROSS THE UPPER
GREAT LAKES. THIS POTENTIAL GALE EVENT IS A LITTLE LESS CERTAIN AS
IT WOULD BE HIGHLY DEPENDENT ON THE TRACK OF THE HIGH. IF THE HIGH
CENTER SLIDES MORE OVER THE OHIO VALLEY...THERE WILL BE A BETTER
CHANCE FOR NWLY GALES...BUT IF THE HIGH TAKES A MORE NORTHERLY
TRACK...THEN WINDS WOULD BE LIGHTER. WILL NOT ISSUE A HEADLINE FOR
THIS SECOND POTENTIAL GALE EVENT...BUT WILL CARRY THE POSSIBILITY IN
THE TEXT OF THE FORECAST.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020 UNTIL 6 PM
WEDNESDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM WEDNESDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...9 PM WEDNESDAY TO 9 PM THURSDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...11 PM
WEDNESDAY TO 3 PM THURSDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...1 AM THURSDAY TO 4 AM
FRIDAY.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
219 PM CST Wed Dec 4 2013
.DISCUSSION...
ISSUED 220 PM CST Wed Dec 4 2013
Lots to talk about this afternoon with a change to winter almost
upon us. Models in general agreement with series of systems
through weekend. A Winter Storm Watch will be required for I-70
and southward for potential of 5-8 inches of snow.
SHORT TERM...Tonight through Friday
Sfc low now over North central Iowa will move northeast and swing
a cold front across Illinois overnight. Cold front is currently moving
across E Iowa and NW Missouri at this time with 15-25 degree
temperature drops and gusty northwest winds. Some partial
temporary clearing of low clouds and fog that has enveloped much
of the area today should be expected behind front. Much colder air
will blast into Illinois tonight and early Thursday with highs
20-30 degrees cooler than todays.
The front slows and stalls to our southeast as it becomes parallel
with the upper flow. A series of disturbances riding along the
front will produce several periods of precipition across southeast
Illinois late Thursday through Friday. Temperatures should be near
freezing by then. Although a brief period of freezing rain/sleet
at the onset is possible. Cold air should quickly change any
precip over to snow pretty quickly as 850 temps drop. NAM is a bit
slower in moving the coldest 850 temps in during the evening and
has a longer period of potential ZR/IP, but appears to be outlier.
Will follow closer to phase change timing suggested by ECMWF and
GFS.
Although mixing ratios are running 4-5 g/Kg, isentropic lift is not
very impressive. Warm ground may also lower amounts slightly early
on, but intensity of snow should overcome this limitation by
middle evening. Even with tempering snowfall amounts some, ECMWF
low-level temps and HPC precip guidance give snow amounts
approaching 8 inches south of U.S. 50. Will be issuing a Winter
Storm Watch for I-70 and southward for 5-8 inches of snow through
the event.
At this time it appears that there may be a lull between systems
Friday morning before precip picks up again Friday afternoon as
the next disturbance moves through and finally pushes the front
and its associated precip further east and out of Illinois late
Friday afternoon.
There looks like there will be a fairly quick cutoff to the
northwest of the precip shield as drier air advecting in will
erode the precip. Snow amounts will likely be light from
I-72/Danville northward with most locations northwest of a
Jacksonville/Lincoln/Bloomington line remaining dry.
LONG TERM...Friday Night through Wednesday
Colder air moves into the region behind the system dropping 850 mb
temps into the -7 to -11 C range. Wind chill temperatures will
likely range from around -5F along I-74 to just above zero south
of I-70 by Saturday morning.
As a trough digs along the west coast, we once again develop a
southwest flow above the cold boundary layer on Saturday Night and
by Sunday snow chances will once again manifest themselves with up
to an inch or two possible across much of the region in broad warm
advection pattern at 700-850 mb. Will have to watch this system
closely for potential for mixed precip with temperatures below freezing,
but for now will keep all snow.
Even colder temperatures are expected early next week as the
Hudson Bay Vortex deepens and brings another cold front across
Illinois Monday and Monday Night. 850 mb temps drop into the -10
to -15C range with wind chills below zero across the entire area
Tuesday morning.
Barker
&&
.AVIATION...
ISSUED 1132 AM CST Wed Dec 4 2013
LIFR conditions continue to plague the TAF sites at midday, with
locally lower conditions near KBMI which has persistent visibility
near 1/16SM. Should see some slow improvements with ceilings and
visibilities this afternoon as visible satellite and surface obs
show some higher ceilings heading northward. Fairly good sized
area of central/eastern Missouri has lost most of its low clouds,
and the latest RAP guidance suggests areas around KSPI/KDEC could
potentially reach into VFR range for a couple hours around midday.
For now will keep broken cloud cover around 2500 feet there
mid/late afternoon.
Strong cold front will sweep through central Illinois this
evening, swinging winds around to the southwest. Guidance from the
RAP and NAM models show VFR conditions becoming likely after 06Z.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from Thursday evening through Friday
afternoon FOR ILZ062-063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1219 PM CST WED DEC 4 2013
.DISCUSSION...
1046 AM CST
MAIN FORECAST CONCERNS FOR THIS MORNING UPDATE ARE WITH THE DENSE
FOG THAT REMAINS IN PLACE...CONTINUING AND EVEN EXPANDING THE
ADVISORY INTO 00Z TONIGHT.
HAVE EXTENDED THE DENSE FOG ADVISORY THRU 00Z TONIGHT AS DENSE FOG
PERSISTS THIS MORNING. AS LOW PRESSURE LIFTS NORTHEAST ACROSS THE
REGION...THE CWA CONTINUES TO OBSERVE STRONG MOISTURE AND TEMP
ADVECTION. THIS IS RESULTING IN WELL ABOVE NORMAL TEMPS...AND AN
ABUNDANCE OF MOISTURE ACROSS A GOOD PORTION OF THE REGION. INITIAL
THOUGHTS WERE TO LET THE ADVISORY EXPIRE THIS MORNING WITH
INCREASING DEW POINT DEPRESSIONS. ALTHOUGH WITH SLOWLY RISING
TEMPS THIS MORNING...DEW POINTS HAVE RISEN ALONG WITH THEM. AREAS
LIKELY TO OBSERVE PERSISTENT LOW DEW POINT DEPRESSIONS AND DENSE
FOG WERE FOR AREAS IN THE CURRENT ADVISORY. LATEST TRENDS THIS
MORNING AS WELL AS WEBCAMS SHOWED AREAS JUST OUTSIDE OF THE
ADVISORY FROM LA SALLE NORTHEAST TO COOK DID INDICATE THE MORE
DENSE FOG WAS PERSISTING...AND SO HAVE INCLUDED THEM IN THE
ADVISORY. ALTHOUGH FOR COOK...THE MORE LIKELY AREAS TO OBSERVE
THIS DENSE FOG WOULD BE ACROSS THE EAST AND NORTHEAST SIDES OF THE
COUNTY...WITH VERY MOIST CONDITIONS OVER THE LAKE AND A SOUTHEAST
WIND ALLOWING DENSE FOG TO AFFECT AREAS ALONG THE SHORE. WITH
SIMILAR CONDITIONS TO PERSIST ACROSS THE ENTIRE AREA UNTIL FROPA
AROUND THE 00Z TIME FRAME...FOG SHOULD PERSIST BUT WILL THEN
IMPROVE THIS EVENING WITH DRIER AIR FILTERING IN ON THE BACKSIDE
OF THIS SYSTEM.
RODRIGUEZ
//PREV DISCUSSION...
406 AM CST
FORECAST CONCERNS THIS MORNING FOCUS ON DENSE FOG TRENDS THIS
MORNING...AND TRENDS INTO THIS AFTERNOON WITH MILD TEMPS UNTIL COLD
FROPA LATE AFTERNOON/EVENING. COLDER AIR COMES IN TWO PUSHES...
FIRST BEHIND THE FRONT TONIGHT AND THEN A SECOND PUSH FRIDAY
NIGHT-SATURDAY AS ARCTIC HIGH BUILDS MORE SOLIDLY EAST ACROSS THE
GREAT LAKES REGION. COUPLE OF CHANCES OF SOME LIGHT ACCUMULATING
SNOW IN THE COMING DAYS...INITIALLY ACROSS FAR SOUTHEAST CWA LATE
THURSDAY INTO FRIDAY...AND AND ACROSS THE CWA SUNDAY-SUNDAY NIGHT.
EVEN COLDER PUSH OF ARCTIC AIR APPEARS HEADED FOR THE AREA BY THE
MIDDLE OF NEXT WEEK.
VERY MILD AND MOIST AIR MASS IN PLACE ACROSS THE REGION EARLY THIS
MORNING...WITH BOTH SFC TEMPS AND DEW POINTS IN THE 40S WITH VERY
SMALL DEPRESSIONS. DENSE FOG WITH VISIBILITY LESS THAN 1/2SM
CONTINUES ACROSS THE FAR NORTHERN IL COUNTIES ROUGHLY NORTH OF A
STERLING TO DEKALB AND WAUKEGAN LINE AS OF 330 AM CST...WITH A
SMALLER AREA OF DENSE FOG OVER EAST CENTRAL IL. HIGH-RES GUIDANCE
INCLUDING HOPWRF AND NARRE TIME-LAGGED ENSEMBLES INDICATE THERE MAY
BE SOME IMPROVEMENT IN VISIBILITY ACROSS THE NORTHERN COUNTIES THIS
MORNING...WHILE SOME ENSEMBLE MEMBERS EXPAND DENSE FOG ACROSS
CENTRAL IL PRIOR TO ABOUT 15Z AND THEN DECREASE COVERAGE. OBS AT
PNT-IKK AND RZL HAVE NOT SHOWN A SIGNIFICANT DOWNWARD TREND AT THIS
TIME. WILL LEAVE ONGOING DENSE FOG ADVISORY ACROSS THE NORTH AS
IS...AND WILL CONTINUE TO MONITOR TRENDS ACROSS THE SOUTH FOR THE
POSSIBILITY OF NEEDING A HEADLINE THERE. WHILE VISIBILITY MAY
IMPROVE SOMEWHAT...AREAS OF FOG WILL LIKELY STICK AROUND INTO THE
AFTERNOON BEFORE AN INCREASE IN SCATTERED SHOWER COVERAGE...WARMER
DAYTIME TEMPERATURES AND THE EVENTUAL COLD FRONTAL PASSAGE CLEAR
THINGS OUT THIS EVENING.
WHILE COLDER MORE TYPICAL EARLY WINTER WEATHER WILL SPREAD INTO THE
AREA TONIGHT/THURSDAY...THE DEPARTING COLD FRONT WILL SLOW AS IT
BECOMES PARALLEL WITH THE MID/UPPER FLOW AND MOVES INTO THE EASTERN
LAKES AND OHIO VALLEY OVER THE NEXT 24-36 HOURS. THIS WILL LIMIT THE
EXTENT OF THE COLD AIR INTRUSION BEHIND THE FRONT...AND WILL LEAVE
THE ELEVATED FRONTAL ZONE ACROSS CENTRAL IL AND NORTHERN INDIANA
INTO FRIDAY. GUIDANCE REMAINS FAIRLY SIMILAR IN BRINGING TWO
SEPARATE DISTURBANCES ALONG THIS BAROCLINIC ZONE WITH THE FIRST LATE
THURSDAY/THURSDAY NIGHT...AND THE OTHER DURING THE DAY ON FRIDAY.
REASONABLY SIMILAR QPF OUTPUT FROM THE VARIOUS MODELS OF THE
AVAILABLE GUIDANCE INDICATE THE POTENTIAL FOR GENERALLY LESS THAN AN
INCH OF SNOW ACROSS THE FAR SOUTHEAST TIER OF COUNTIES OF THE CWA
BEFORE THE SECOND SHORT WAVE DEPARTS LATE FRIDAY...WITH FLURRIES
PERHAPS AS FAR NORTH AS A PONTIAC-WHITING LINE. AFTER THIS SECOND
SLIGHTLY MORE AMPLIFIED WAVE DEPARTS...ARCTIC HIGH PRESSURE BUILDS
MORE ROBUSTLY EAST ACROSS MINNESOTA AND WISCONSIN FRIDAY NIGHT AND
SETS THE STAGE FOR CHILLY TEMPS IN THE SINGLE DIGITS AWAY FROM THE
CITY FRIDAY NIGHT...AND ONLY IN THE TEENS TO LOW 20S SATURDAY.
LONGER RANGE GUIDANCE ALSO REMAINS IN DECENT AGREEMENT IN BRINGING
ANOTHER SHORT WAVE INTO THE REGION SUNDAY-SUNDAY NIGHT...WITH SOME
SPREAD IN THE MODEL SOLUTIONS LOOKING A LITTLE MORE IN AGREEMENT
WITH THE NEW 00Z ECMWF SIMILAR TO THE GFS IN BRINGING LOW PRESSURE
THROUGH THE OHIO VALLEY DURING THAT TIME. LIGHT SNOW LOOKS TO COVER
MOST/ALL OF THE CWA WITH THIS SYSTEM...AND HAVE BUMPED POPS TO
LIKELY IN MOST AREAS.
ANOTHER SURGE OF ARCTIC AIR THEN LOOKS TO SPREAD INTO THE AREA
BEHIND THIS SYSTEM MONDAY-TUESDAY. BOTH ECMWF/GFS MOS GUIDANCE
SHOWING LOWS IN THE SINGLE DIGITS BY TUESDAY MORNING...WITH HIGHS
ONLY AROUND 12-15 TUESDAY. THIS IS IMPRESSIVE GIVEN STRONG CLIMO
WEIGHTING IN THE MOS BY DAY 7...SOME 22-25 DEGREES BELOW NORMAL FOR
HIGHS FOR EARLY DECEMBER. BRRR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CEILINGS...CONTINUED PREVAILING LOW END IFR TEMPO LIFR INTO LATE
AFTERNOON-EARLY EVENING...THEN IMPROVEMENT TO MVFR FOR REST OF
NIGHT.
* VISIBILITY...PREVAILING IFR IMPROVING TO MVFR INTO LATE
AFTERNOON-EARLY EVENING...THEN TO VFR MID EVENING AND BEYOND.
* PATCHY -DZ/-RA BECOMING MORE WIDESPREAD FOR MID AFTERNOON TO
EARLY EVENING.
* WIND SHIFT WITH COLD FRONTAL PASSAGE THIS EVENING BRINGING
MODERATELY GUSTY WINDS INTO THU.
TRS
//DISCUSSION...UPDATED 18Z...
SURFACE LOW BECOMING BETTER ORGANIZED 50SM S OF MSP AT 17Z WITH
ELONGATED PRESSURE FALL CENTER FROM E MN ACROSS W CENTRAL AND N
WI... MI U.P. AND LAKE SUPERIOR. MODELS TAKE THIS LOW NNE TO FAR
E CENTRAL MN AT 21Z AND TO TO FAR SE MN BY 18Z THEN NE TO NW-N
CENTRAL WI BY 00Z.
SE-SSE LOW LEVEL WINDS ACROSS THE LOCAL AREA CONTINUE TO ADVECT
WARMER BUT ALSO HIGHER DEW POINT AIR WITH SURFACE DEW POINT
DEPRESSIONS OF 0-1 DEG F OVER ALL BUT EXTREME S PORTIONS OF IL
AND IN. CONTINUED FEED OF THIS LOW DEW POINT DEPRESSION AIR
EXPECTED TO MAINTAIN RESTRICTED VSBY AND LOW CEILINGS UNTIL THE
SURFACE WINDS VEER A BIT TO S-SSW LATE AFTERNOON-EARLY EVENING AS
THE LOW MOVES TO N WI. THIS SLIGHT W COMPONENT TO THE LOW LEVEL
FLOW STARTS TO ADVECT IN SOMEWHAT GREATER DEW POINT DEPRESSIONS
WHICH IS EXPECTED TO RESULT IN SOME INCREASE IN VISIBILITY AND
CEILING HEIGHT.
A FEW PATCHES OF -DZ/-RA CURRENTLY MOVING NE AND FAR N CENTRAL
IL. MODELS CONTINUE TO SHOW PERSISTENT AND GRADUALLY INCREASING
BUT STILL SOMEWHAT WEAK UVV DOWN INTO THE LOW LEVEL MOISTURE
THROUGH EARLY EVENING AS A MID LEVEL SHORT WAVE TROUGH ROTATES NE
OVER THE MID MS VALLEY. EXPECT CURRENT LOW COVERAGE LIGHT LIQUID
PRECIP TO BECOME SOMEWHAT BROADER BY MID AFTERNOON IN RESPONSE TO
STRENGTHENING LOW LEVEL ISENTROPIC LIFT.
WITH THE LOW PROGGED TO MOVE TO W LAKE SUPERIOR BY 06Z THE
TRAILING COLD FRONT IS EXPECTED TO PUSH W TO E ACROSS THE LOCAL
AREA EARLY-MID EVENING. STRONG COLD AIR ADVECTION AND PRESSURE
RISES WILL RESULT IN INCREASING AND MODERATELY GUSTY WINDS BEHIND
THE FRONT. CURRENTLY...UPSTREAM WINDS BEHIND THE FRONT ARE OUT OF
THE NW BUT WITH THE LOW MOVING NNE AND AWAY FROM THE AREA TONIGHT
EXPECT LOCAL WINDS TO BE WSW-W. SUBSIDENCE AND DRYING FOLLOWING
FROPA SHOULD ALLOW CEILINGS TO RISE TO MVFR AS CURRENT OBSERVED
FROM NE OK TO SE NEB.
ANOTHER SHORT WAVE TROUGH PROGGED TO BE EXTENDING FROM N CENTRAL
WI SW TO S CENTRAL IA AT 05.18Z BUT WITH NO MID LEVEL MOISTURE TO
WORK WITH AND THE CONTINUED DECREASE IN LOW LEVEL MOISTURE AM
ANTICIPATING NO PRECIP WITH THIS DISTURBANCE AND ONLY CIRRUS
CEILINGS BY SUNRISE THU.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
*MEDIUM CONFIDENCE IN CIG TRENDS.
*MEDIUM CONFIDENCE IN VSBY TRENDS.
*HIGH CONFIDENCE IN WINDS THROUGH PERIOD INCLUDING TIMING OF WSHFT
WITH FROPA +/- 2HR.
*HIGH CONFIDENCE IN -SHRA/-RA OCCURRING THIS AFTERNOON AND THEN NO
PRECIP TONIGHT.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH SATURDAY...VFR.
SUNDAY...CHC SNOW...WITH SNOW LIKELY SUNDAY NIGHT.
MONDAY...SLT CHC SNOW. MVFR POSSIBLE.
TUESDAY...PRIMARILY VFR.
BMD
&&
.MARINE...
239 AM CST
MODELS ARE FINALLY SYNCED UP ON DEEPENING LOW PRESSURE WHICH IS
EXPECTED TO LIFT ACROSS WISCONSIN LATE THIS AFTERNOON...AND ACROSS
LATE SUPERIOR TONIGHT. MODERATE EASTERLY FLOW AROUND 30 KTS IS
EXPECTED NORTH OF A WARM FRONT STRADDLING THE MID SECTION OF THE
LAKE THIS MORNING...WITH STABLE SOUTHEASTERLY FLOW ACROSS THE SOUTH
OF THE FRONT. MID/UPPER 40 DEWPOINTS ADVECTING OVER THE LOW/MID 40
DEGREE WATER TEMPERATURES IS EXPECTED TO RESULT IN WIDESPREAD DENSE
FOG. A DENSE FOG ADVISORY IS IN EFFECT ACROSS THE SOUTH HALF OF THE
LAKE...BUT MAY NEED TO BE EXTENDED NORTH AS THE FRONT LIFTS ACROSS
THE REMAINDER OF THE LAKE. OVERNIGHT A COLD FRONT WILL SWEEP ACROSS
THE LAKE WITH WINDS TURNING WESTERLY BEHIND. STRONG COLD ADVECTION
WILL HELP TO MIX DOWN GALES...PRIMARILY ACROSS THE NORTH END OF THE
LAKE WHERE THE GRADIENT IS TIGHTEST...THOUGH APPEARS FOR NOW TO BE
LOW END GALE EVENT. A GALE WATCH REMAINS IN EFFECT FOR THE NORTH
PORTIONS OF THE LAKE. A STRONG HIGH WILL SETTLE ACROSS THE NORTHERN
PLAINS FRIDAY THOUGH LATE SATURDAY RESULTING IN WINDS STAYING
ELEVATED IN THE 20 TO 25 KT RANGE...WITH A FEW PERIODS OF 30 KTS.
ANOTHER LOW IS EXPECTED TO LIFT FROM THE LOWER MISSISSIPPI VALLEY
INTO THE EASTERN LAKES REGION EARLY NEXT WEEK.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020 UNTIL 6 PM
WEDNESDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM WEDNESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 AM THURSDAY TO 3 PM THURSDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...11 PM
WEDNESDAY TO 3 PM THURSDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...1 AM THURSDAY TO 4 AM
FRIDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
1132 AM CST Wed Dec 4 2013
.DISCUSSION...
ISSUED 1000 AM CST Wed Dec 4 2013
Dense fog starting to slowly lift in some areas. Have lopped off a
few counties from the advisory from Springfield westward where
visibility has been more persistently around a mile or so. Seeing
some variable visibilities from Peoria northwest and also over the
southeast counties, and will evaluate over the next hour whether
to drop the advisory there too or let it ride until its natural
conclusion at noon. HRRR model showing a more persistent lifting
of the dense fog over the next couple hours, although the RAP
lingers it east of I-57 into early afternoon.
Latest surface map shows low pressure over central Missouri, with
a secondary low over south central Iowa which should become the
primary low late today. Should start seeing the cold front moving
into the Illinois River valley toward 5-6 pm and across most of
the CWA by 10 pm.
Geelhart
&&
.AVIATION...
ISSUED 1132 AM CST Wed Dec 4 2013
LIFR conditions continue to plague the TAF sites at midday, with
locally lower conditions near KBMI which has persistent visibility
near 1/16SM. Should see some slow improvements with ceilings and
visibilities this afternoon as visible satellite and surface obs
show some higher ceilings heading northward. Fairly good sized
area of central/eastern Missouri has lost most of its low clouds,
and the latest RAP guidance suggests areas around KSPI/KDEC could
potentially reach into VFR range for a couple hours around midday.
For now will keep broken cloud cover around 2500 feet there
mid/late afternoon.
Strong cold front will sweep through central Illinois this
evening, swinging winds around to the southwest. Guidance from the
RAP and NAM models show VFR conditions becoming likely after 06Z.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 311 AM CST Wed Dec 4 2013
Main forecast concern continues to be potential for accumulating
snow and ice across parts of central Illinois late Thursday into
Friday.
SHORT TERM...Today through Friday
Widespread fog once again blankets the area early this morning.
Moist low-level airmass remains in place, with 08z/2am surface
dewpoints well into the 40s. This ample moisture combined with
light winds will allow visibilities to continue to drop over the
next couple of hours. NAM/GFS forecast soundings and latest HRRR
visby forecast all point to widespread dense fog through much of
the morning. Will therefore be issuing a Dense Fog Advisory for
the entire KILX CWA through midday. Fog will gradually dissipate
by early afternoon, although visibilities will continue to be
somewhat limited until cold front pushes through late this
afternoon into the evening. Despite FROPA later today, shallow
moisture below 5000ft will limit precip potential. Will therefore
only mention isolated showers today into this evening. High
temperatures will be quite a bit warmer than they were yesterday,
but will be tempered by the fog/clouds to some extent. Will go
near or slightly above MAV guidance numbers, but not as high as
the warmer MET. Resulting highs will mainly be in the upper 50s
and lower 60s.
Once front passes, much colder air will arrive tonight into
Thursday. Overnight lows will drop into the upper 20s and lower
30s across much of the area, but will remain in the upper 30s
further east near the Indiana border. High temperatures on
Thursday will not rise much from the early morning lows, with
readings ranging from the upper 20s along/west of the Illinois
River to around 40 degrees along the Wabash River.
Models are in good agreement with the development of wintry precip
across parts of central and southeast Illinois late Thursday into
Friday, with a few minor differences still remaining. NAM has
slowed the onset of precip until early evening, while GFS/ECMWF/GEM
still bring it in during the afternoon. Given drier airmass behind
departing front, think NAM may have the right idea. Will therefore
delay initial precip development until late afternoon, with main
push arriving during the evening. Airmass will be cold enough to
support snow across most of the area: however, warm layer aloft
with max temps of around 4C supports mixed phase precip along and
south of I-70. Late afternoon surface temps in the upper 30s to
around 40 will allow for mainly rain along and south of highway
50. As the evening progresses, deepening cold layer will allow for
a gradual change over to mainly snow across the SE KILX CWA
overnight, although areas along and south of highway 50 may
experience a period of freezing rain as surface temps dip below
32 degrees. Any icing will be minimal, as precip transitions to
snow/sleet after midnight.
Initial wave of precip wanes after midnight, followed by another
wave on Friday. Model differences here focus on how far into the
cold airmass to spread the precip. NAM is most aggressive, while
GFS remains further southeast. Given strength of approaching high
within the cold airmass, think GFS solution is most logical. As a
result, will focus highest POPs for snow across the E/SE CWA. Once
the wintry precip ends Friday afternoon, total snowfall
accumulations of 3 to 5 inches will be likely along and south of
I-70. Amounts will steadily decrease further northwest, with up
to 1 inch possible along a Jacksonville to Danville line. Further
north, only a few flurries are expected along and north of a
Rushville to Bloomington-Normal line.
LONG TERM...Saturday through Tuesday
Cold weather will prevail throughout the extended, with only a brief
moderation in temps expected on Sunday. Models continue to show
another short-wave trough digging southward into the western
CONUS this weekend, resulting in downstream ridging over the
southeast states. As flow becomes more southwesterly aloft,
frontal boundary along the Gulf Coast will get pushed back
northward Sunday into Monday. It appears deepest moisture and
highest precip chances will remain southeast of Illinois across
the Tennessee and Ohio River Valleys, although the GFS is slightly
more aggressive in bringing precip further northwest into the cold
air than the ECMWF. At this point, will trend toward the ECMWF and
will only feature low chance POPs for snow Sunday and Sunday night
with minimal accumulations. After that, another very cold airmass
will drop into the Midwest by early next week, resulting in high
temps in the teens by Tuesday.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until Noon CST today FOR ILZ027>031-036>038-
041>045-053.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1042 AM CST WED DEC 4 2013
.DISCUSSION...
406 AM CST
FORECAST CONCERNS THIS MORNING FOCUS ON DENSE FOG TRENDS THIS
MORNING...AND TRENDS INTO THIS AFTERNOON WITH MILD TEMPS UNTIL COLD
FROPA LATE AFTERNOON/EVENING. COLDER AIR COMES IN TWO PUSHES...
FIRST BEHIND THE FRONT TONIGHT AND THEN A SECOND PUSH FRIDAY
NIGHT-SATURDAY AS ARCTIC HIGH BUILDS MORE SOLIDLY EAST ACROSS THE
GREAT LAKES REGION. COUPLE OF CHANCES OF SOME LIGHT ACCUMULATING
SNOW IN THE COMING DAYS...INITIALLY ACROSS FAR SOUTHEAST CWA LATE
THURSDAY INTO FRIDAY...AND AND ACROSS THE CWA SUNDAY-SUNDAY NIGHT.
EVEN COLDER PUSH OF ARCTIC AIR APPEARS HEADED FOR THE AREA BY THE
MIDDLE OF NEXT WEEK.
VERY MILD AND MOIST AIR MASS IN PLACE ACROSS THE REGION EARLY THIS
MORNING...WITH BOTH SFC TEMPS AND DEW POINTS IN THE 40S WITH VERY
SMALL DEPRESSIONS. DENSE FOG WITH VISIBILITY LESS THAN 1/2SM
CONTINUES ACROSS THE FAR NORTHERN IL COUNTIES ROUGHLY NORTH OF A
STERLING TO DEKALB AND WAUKEGAN LINE AS OF 330 AM CST...WITH A
SMALLER AREA OF DENSE FOG OVER EAST CENTRAL IL. HIGH-RES GUIDANCE
INCLUDING HOPWRF AND NARRE TIME-LAGGED ENSEMBLES INDICATE THERE MAY
BE SOME IMPROVEMENT IN VISIBILITY ACROSS THE NORTHERN COUNTIES THIS
MORNING...WHILE SOME ENSEMBLE MEMBERS EXPAND DENSE FOG ACROSS
CENTRAL IL PRIOR TO ABOUT 15Z AND THEN DECREASE COVERAGE. OBS AT
PNT-IKK AND RZL HAVE NOT SHOWN A SIGNIFICANT DOWNWARD TREND AT THIS
TIME. WILL LEAVE ONGOING DENSE FOG ADVISORY ACROSS THE NORTH AS
IS...AND WILL CONTINUE TO MONITOR TRENDS ACROSS THE SOUTH FOR THE
POSSIBILITY OF NEEDING A HEADLINE THERE. WHILE VISIBILITY MAY
IMPROVE SOMEWHAT...AREAS OF FOG WILL LIKELY STICK AROUND INTO THE
AFTERNOON BEFORE AN INCREASE IN SCATTERED SHOWER COVERAGE...WARMER
DAYTIME TEMPERATURES AND THE EVENTUAL COLD FRONTAL PASSAGE CLEAR
THINGS OUT THIS EVENING.
WHILE COLDER MORE TYPICAL EARLY WINTER WEATHER WILL SPREAD INTO THE
AREA TONIGHT/THURSDAY...THE DEPARTING COLD FRONT WILL SLOW AS IT
BECOMES PARALLEL WITH THE MID/UPPER FLOW AND MOVES INTO THE EASTERN
LAKES AND OHIO VALLEY OVER THE NEXT 24-36 HOURS. THIS WILL LIMIT THE
EXTENT OF THE COLD AIR INTRUSION BEHIND THE FRONT...AND WILL LEAVE
THE ELEVATED FRONTAL ZONE ACROSS CENTRAL IL AND NORTHERN INDIANA
INTO FRIDAY. GUIDANCE REMAINS FAIRLY SIMILAR IN BRINGING TWO
SEPARATE DISTURBANCES ALONG THIS BAROCLINIC ZONE WITH THE FIRST LATE
THURSDAY/THURSDAY NIGHT...AND THE OTHER DURING THE DAY ON FRIDAY.
REASONABLY SIMILAR QPF OUTPUT FROM THE VARIOUS MODELS OF THE
AVAILABLE GUIDANCE INDICATE THE POTENTIAL FOR GENERALLY LESS THAN AN
INCH OF SNOW ACROSS THE FAR SOUTHEAST TIER OF COUNTIES OF THE CWA
BEFORE THE SECOND SHORT WAVE DEPARTS LATE FRIDAY...WITH FLURRIES
PERHAPS AS FAR NORTH AS A PONTIAC-WHITING LINE. AFTER THIS SECOND
SLIGHTLY MORE AMPLIFIED WAVE DEPARTS...ARCTIC HIGH PRESSURE BUILDS
MORE ROBUSTLY EAST ACROSS MINNESOTA AND WISCONSIN FRIDAY NIGHT AND
SETS THE STAGE FOR CHILLY TEMPS IN THE SINGLE DIGITS AWAY FROM THE
CITY FRIDAY NIGHT...AND ONLY IN THE TEENS TO LOW 20S SATURDAY.
LONGER RANGE GUIDANCE ALSO REMAINS IN DECENT AGREEMENT IN BRINGING
ANOTHER SHORT WAVE INTO THE REGION SUNDAY-SUNDAY NIGHT...WITH SOME
SPREAD IN THE MODEL SOLUTIONS LOOKING A LITTLE MORE IN AGREEMENT
WITH THE NEW 00Z ECMWF SIMILAR TO THE GFS IN BRINGING LOW PRESSURE
THROUGH THE OHIO VALLEY DURING THAT TIME. LIGHT SNOW LOOKS TO COVER
MOST/ALL OF THE CWA WITH THIS SYSTEM...AND HAVE BUMPED POPS TO
LIKELY IN MOST AREAS.
ANOTHER SURGE OF ARCTIC AIR THEN LOOKS TO SPREAD INTO THE AREA
BEHIND THIS SYSTEM MONDAY-TUESDAY. BOTH ECMWF/GFS MOS GUIDANCE
SHOWING LOWS IN THE SINGLE DIGITS BY TUESDAY MORNING...WITH HIGHS
ONLY AROUND 12-15 TUESDAY. THIS IS IMPRESSIVE GIVEN STRONG CLIMO
WEIGHTING IN THE MOS BY DAY 7...SOME 22-25 DEGREES BELOW NORMAL FOR
HIGHS FOR EARLY DECEMBER. BRRR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CEILINGS...CONTINUED PREVAILING LOW END IFR NTO LATE AFTERNOON-
EARLY EVENING...THEN SLIGHT IMPROVEMENT TO LOW END MVFR FOR
REST OF NIGHT.
* VISIBILITY...PREVAILING HIGH END IFR CAT-LOW END MVFR CAT INTO
EARLY EVENING IMPROVING TO MVFR INTO LATE AFTERNOON-EARLY
EVENING...THEN VFR MID EVENING AND BEYOND.
* PATCHY -DZ/-RA THROUGH EARLY AFTERNOON THEN BECOMING MORE
WIDESPREAD FOR MID AFTERNOON TO EARLY EVENING.
* WIND SHIFT THIS EVENING WITH COLD FRONTAL PASSAGE.
TRS
//DISCUSSION...UPDATED 16Z...
SURFACE LOW BECOMING BETTER ORGANIZED JUST NE OF DSM WITH PRES
FALL CENTER OVER SE NM AND W CENTRAL TO NW WI. MODELS TAKE THIS
LOW TO FAR SE MN BY 18Z AND N WI BY 00Z. SE-SSE LOW LEVEL WINDS
ACROSS THE LOCAL AREA ARE ADVECTING IN WARMER BUT ALSO HIGHER DEW
POINT AIR. WITH SURFACE DEW POINT DEPRESSIONS OF 0-1 DEG F
CURRENTLY MOVING OVER THE LOCAL AREA AND EXTENDING WELL UPSTREAM
ACROSS ALL BUT FAR S PORTIONS OF IL AND IN. THIS IS EXPECTED TO
MAINTAIN RESTRICTED VSBY AND LOW CIGS UNTIL LOW REACHES N WI AND
LOCAL SURFACE WIND VEERS A BIT TO S-SSE IN RESPONSE WHICH WILL
DELIVER SOMEWHAT GREATER DEW POINT DEPRESSIONS TO THE LOCAL AREA.
A FEW PATCHES OF -DZ/-RA HAVE RECENTLY MOVED OVER AND N OF ORD AND
MDW. MODELS CONTINUE TO SHOW SOME WEAK BUT PERSISTENT UVV DOWN
INTO THE LOW LEVEL MOISTURE TIL EARLY EVENING. FEW MORE WEAK RADAR
ECHOES MOVING N AND APPROACHING I-80. EXPECT LOW COVERAGE BEFORE
INCREASING MID AFTERNOON.
WITH LOW PROGGED TO MOVE TO OVER/NEAR CENTRAL U.P. OF MI BY 06Z
THE TRAILING COLD FRONT IS EXPECTED TO PUSH W TO E ACROSS THE
LOCAL AREA EARLY-MID EVENING.
TRS
PREVIOUS DISCUSSION...
THIS MORNING...A WARM FRONT LIES JUST NORTH OF THE TERMINALS WITH
SOUTHEAST FLOW AND IFR CONDITIONS IN PLACE ACROSS NORTHERN ILLINOIS
AND NORTHWEST INDIANA. WILL DISCUSS EACH FORECAST ELEMENT
INDIVIDUALLY...
CEILINGS...AS MENTIONED MOST OF THE REGION IS UNDER IFR CIGS THIS
MORNING...THOUGH THERE IS A HOLE IN THE LOWER CIGS THAT STRETCHES
FROM SW MICHIGAN INTO THE SOUTH CHICAGO METRO. GYY HAS MAINTAINED
VFR LEVEL CIGS FOR THE PAST SEVERAL HOURS...AND MDW HAS BEEN IN AND
OUT OF THE IFR CIGS. NAM/HRRR GUIDANCE TO SOME DEGREE HINTING AT
THIS HOLE...WHICH COULD BRIEFLY MOVE OVER ORD THIS MORNING. BOTH
MODELS DO SHOW THE HOLE FILLING IN THOUGH LATE THIS MORNING...SO ANY
TEMPO HIGHER CIGS WILL BE SHORT LIVED THIS MORNING. A SECONDARY WARM
FRONTAL LIKE FEATURE WILL LIFT ACROSS THE AREA THIS AFTERNOON...WITH
WINDS VEERING TO THE S OR SSW. MODELS INDICATE SOME IMPROVEMENT IN
CIGS POSSIBLE AFTER IT PASSES NORTH OF THE TERMINALS...THOUGH THE
DEGREE OF IMPROVEMENT IS UNCERTAIN. IT IS POSSIBLE WE MAY LIFT TO
MVFR AT THIS POINT...BUT WILL ERR ON THE SIDE OF LOWER CIGS FOR NOW
WHICH FITS WELL WITH LAV/MET GUIDANCE. BETTER CHANCE TO LIFT TO MVFR
WILL BE LATER IN THE EVENING AS A COLD FRONT SWEEPS ACROSS THE AREA.
EXPECT THE CIGS TO GRADUALLY RISE OVERNIGHT AS THE COLD AIR ERODES
THE CLOUD BASES.
VISIBILITY...VSBY RANGES FROM NEAR ZERO TO AROUND 4-5SM. DENSEST FOG
IS GENERALLY ALONG AND NEAR THE WARM FRONT AND THIS AREA SHOULD STAY
NORTH OF THE CHICAGO TERMINALS...THOUGH WILL CONTINUE TO IMPACT RFD
THROUGH THE MORNING. MODEL GUIDANCE IS ALL OVER THE PLACE WITH
RESPECT TO VSBY TRENDS TODAY. SEVERAL MODELS HINT THAT AS THE
SECONDARY BOUNDARY SOUTH OF THE AREA LIFTS NORTH...LOWER VSBY WILL
ALSO SPREAD NORTH INTO THE CHICAGO METRO. THERE IS ALREADY DENSE FOG
ACROSS PORTIONS OF EAST CENTRAL ILLINOIS...AND WILL HAVE TO MONITOR
THIS AREA CLOSELY AS IT MAY SPREAD NORTH OVER THE TERMINALS...BUT
FOR NOW GIVEN THE LOW CONFIDENCE...WILL STICK CLOSE TO MAV/LAV
TRENDS WHICH HOLD VSBY PRIMARILY MVFR FOR THE CHICAGO TERMINALS
TODAY. ANY PRECIP THAT DEVELOPS THIS AFTERNOON MAY ALSO CAUSE THE
VSBY TO DROP TO IFR.
WINDS...PRIMARILY SOUTHEASTERLY WINDS 6-10KTS ARE EXPECTED THIS
MORNING BEHIND THE FRONT NEAR THE STATE LINE THIS MORNING. WINDS
WILL EVENTUALLY VEER TO THE SOUTH/SSW AS THE SECOND BOUNDARY LIFTS
ACROSS THE AREA MID TO LATE THIS AFTERNOON. LATE THIS EVENING A COLD
FRONT WILL SWEEP ACROSS THE AREA WITH WINDS TURNING WESTERLY...AND
INCREASING WITH GUSTS INTO THE HIGH TEENS EXPECTED OVERNIGHT.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
*MEDIUM CONFIDENCE IN CIG TRENDS.
*MEDIUM CONFIDENCE IN VSBY TRENDS.
*HIGH CONFIDENCE IN WINDS INTO MID EVENING...THEN MODERATE
CONFIDENCE REST OF PERIOD.
*MEDIUM CONFIDENCE IN -SHRA/-RA OCCURRENCE THIS AFTERNOON.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH SATURDAY...VFR.
SUNDAY...CHC SNOW...WITH SNOW LIKELY SUNDAY NIGHT.
MONDAY...SLT CHC SNOW. MVFR POSSIBLE.
TUESDAY...PRIMARILY VFR.
BMD
&&
.MARINE...
239 AM CST
MODELS ARE FINALLY SYNCED UP ON DEEPENING LOW PRESSURE WHICH IS
EXPECTED TO LIFT ACROSS WISCONSIN LATE THIS AFTERNOON...AND ACROSS
LATE SUPERIOR TONIGHT. MODERATE EASTERLY FLOW AROUND 30 KTS IS
EXPECTED NORTH OF A WARM FRONT STRADDLING THE MID SECTION OF THE
LAKE THIS MORNING...WITH STABLE SOUTHEASTERLY FLOW ACROSS THE SOUTH
OF THE FRONT. MID/UPPER 40 DEWPOINTS ADVECTING OVER THE LOW/MID 40
DEGREE WATER TEMPERATURES IS EXPECTED TO RESULT IN WIDESPREAD DENSE
FOG. A DENSE FOG ADVISORY IS IN EFFECT ACROSS THE SOUTH HALF OF THE
LAKE...BUT MAY NEED TO BE EXTENDED NORTH AS THE FRONT LIFTS ACROSS
THE REMAINDER OF THE LAKE. OVERNIGHT A COLD FRONT WILL SWEEP ACROSS
THE LAKE WITH WINDS TURNING WESTERLY BEHIND. STRONG COLD ADVECTION
WILL HELP TO MIX DOWN GALES...PRIMARILY ACROSS THE NORTH END OF THE
LAKE WHERE THE GRADIENT IS TIGHTEST...THOUGH APPEARS FOR NOW TO BE
LOW END GALE EVENT. A GALE WATCH REMAINS IN EFFECT FOR THE NORTH
PORTIONS OF THE LAKE. A STRONG HIGH WILL SETTLE ACROSS THE NORTHERN
PLAINS FRIDAY THOUGH LATE SATURDAY RESULTING IN WINDS STAYING
ELEVATED IN THE 20 TO 25 KT RANGE...WITH A FEW PERIODS OF 30 KTS.
ANOTHER LOW IS EXPECTED TO LIFT FROM THE LOWER MISSISSIPPI VALLEY
INTO THE EASTERN LAKES REGION EARLY NEXT WEEK.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020 UNTIL 6 PM
WEDNESDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM WEDNESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 AM THURSDAY TO 3 PM THURSDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...11 PM
WEDNESDAY TO 3 PM THURSDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...1 AM THURSDAY TO 4 AM
FRIDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1000 AM CST Wed Dec 4 2013
.DISCUSSION...
ISSUED 1000 AM CST Wed Dec 4 2013
Dense fog starting to slowly lift in some areas. Have lopped off a
few counties from the advisory from Springfield westward where
visibility has been more persistently around a mile or so. Seeing
some variable visibilities from Peoria northwest and also over the
southeast counties, and will evaluate over the next hour whether
to drop the advisory there too or let it ride until its natural
conclusion at noon. HRRR model showing a more persistent lifting
of the dense fog over the next couple hours, although the RAP
lingers it east of I-57 into early afternoon.
Latest surface map shows low pressure over central Missouri, with
a secondary low over south central Iowa which should become the
primary low late today. Should start seeing the cold front moving
into the Illinois River valley toward 5-6 pm and across most of
the CWA by 10 pm.
Geelhart
&&
.AVIATION...
ISSUED 515 AM CST Wed Dec 4 2013
High resolution models continue to suggest areas that have seen a
temporary break in the low vsbys and cigs will see deteriorating
conditions once again around or just after daybreak this morning.
Model trends off the HRRR and HopWRF continue to suggest VLIFR
vsbys/cigs expanding north into all of our TAF sites after 12z.
Confidence not that great with this scenario...although we have
seen a gradual lowering of cigs and vsbys in areas that saw some
improvement earlier this morning. Poorest conditions look to be
from 12 or 13z thru 18z...and then LIFR/IFR cigs most areas this
afternoon just ahead of a cold front which is currently tracking
across Iowa. Looks as if the cold front should start to push into
our western taf sites by 00z and be east of the CMI area by
05 or 06z tonight. Surface winds ahead of the front will remain
out of the southeast to south at 10 to 15 kts today...and then
shift into west and then northwest after FROPA later this evening.
Smith
&&
.PREV DISCUSSION...
ISSUED 311 AM CST Wed Dec 4 2013
Main forecast concern continues to be potential for accumulating
snow and ice across parts of central Illinois late Thursday into
Friday.
SHORT TERM...Today through Friday
Widespread fog once again blankets the area early this morning.
Moist low-level airmass remains in place, with 08z/2am surface
dewpoints well into the 40s. This ample moisture combined with
light winds will allow visibilities to continue to drop over the
next couple of hours. NAM/GFS forecast soundings and latest HRRR
visby forecast all point to widespread dense fog through much of
the morning. Will therefore be issuing a Dense Fog Advisory for
the entire KILX CWA through midday. Fog will gradually dissipate
by early afternoon, although visibilities will continue to be
somewhat limited until cold front pushes through late this
afternoon into the evening. Despite FROPA later today, shallow
moisture below 5000ft will limit precip potential. Will therefore
only mention isolated showers today into this evening. High
temperatures will be quite a bit warmer than they were yesterday,
but will be tempered by the fog/clouds to some extent. Will go
near or slightly above MAV guidance numbers, but not as high as
the warmer MET. Resulting highs will mainly be in the upper 50s
and lower 60s.
Once front passes, much colder air will arrive tonight into
Thursday. Overnight lows will drop into the upper 20s and lower
30s across much of the area, but will remain in the upper 30s
further east near the Indiana border. High temperatures on
Thursday will not rise much from the early morning lows, with
readings ranging from the upper 20s along/west of the Illinois
River to around 40 degrees along the Wabash River.
Models are in good agreement with the development of wintry precip
across parts of central and southeast Illinois late Thursday into
Friday, with a few minor differences still remaining. NAM has
slowed the onset of precip until early evening, while GFS/ECMWF/GEM
still bring it in during the afternoon. Given drier airmass behind
departing front, think NAM may have the right idea. Will therefore
delay initial precip development until late afternoon, with main
push arriving during the evening. Airmass will be cold enough to
support snow across most of the area: however, warm layer aloft
with max temps of around 4C supports mixed phase precip along and
south of I-70. Late afternoon surface temps in the upper 30s to
around 40 will allow for mainly rain along and south of highway
50. As the evening progresses, deepening cold layer will allow for
a gradual change over to mainly snow across the SE KILX CWA
overnight, although areas along and south of highway 50 may
experience a period of freezing rain as surface temps dip below
32 degrees. Any icing will be minimal, as precip transitions to
snow/sleet after midnight.
Initial wave of precip wanes after midnight, followed by another
wave on Friday. Model differences here focus on how far into the
cold airmass to spread the precip. NAM is most aggressive, while
GFS remains further southeast. Given strength of approaching high
within the cold airmass, think GFS solution is most logical. As a
result, will focus highest POPs for snow across the E/SE CWA. Once
the wintry precip ends Friday afternoon, total snowfall
accumulations of 3 to 5 inches will be likely along and south of
I-70. Amounts will steadily decrease further northwest, with up
to 1 inch possible along a Jacksonville to Danville line. Further
north, only a few flurries are expected along and north of a
Rushville to Bloomington-Normal line.
LONG TERM...Saturday through Tuesday
Cold weather will prevail throughout the extended, with only a brief
moderation in temps expected on Sunday. Models continue to show
another short-wave trough digging southward into the western
CONUS this weekend, resulting in downstream ridging over the
southeast states. As flow becomes more southwesterly aloft,
frontal boundary along the Gulf Coast will get pushed back
northward Sunday into Monday. It appears deepest moisture and
highest precip chances will remain southeast of Illinois across
the Tennessee and Ohio River Valleys, although the GFS is slightly
more aggressive in bringing precip further northwest into the cold
air than the ECMWF. At this point, will trend toward the ECMWF and
will only feature low chance POPs for snow Sunday and Sunday night
with minimal accumulations. After that, another very cold airmass
will drop into the Midwest by early next week, resulting in high
temps in the teens by Tuesday.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until noon CST today for ILZ027>031-036>038-
041>046-052>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
236 PM MST WED DEC 4 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 223 PM MST WED DEC 4 2013
ARCTIC COLD HAS ENTERED THE CWA AND IS EXPECTED TO STICK AROUND FOR
A WHILE. SOME LIGHT SNOW FELL THIS MORNING...WITH HEAVIEST BANDS
OVER EASTERN COLORADO BRINGING NEARLY AN INCH IN A FEW SPOTS.
TONIGHT ANOTHER ROUND OF SNOWFALL IS EXPECTED WHICH COULD BRING A
QUICK INCH IN A FEW SPOTS...BUT OTHERWISE THE COLD WILL BE THE MAIN
HAZARD IN THE SHORT TERM.
TODAY...SUBSIDENCE ACROSS THE TRI-STATE LEAD TO SNOWFALL ENDING AND
EVEN SOME CLEARING SKIES...AND HIGHS WERE A CHALLENGE OF BALANCING
THE ADDITIONAL SOLAR RADIATION WITH COLD AIR ADVECTION. WINDS ARE A
BIT STRONGER THAN THE ORIGINAL FORECAST...BUT A BLEND OF 12Z MOS
GUIDANCE HANDLED THE STRONGER WINDS A LITTLE BETTER THAN MOST OF THE
OTHER GUIDANCE.
TONIGHT...MUCH OF EASTERN COLORADO AND PARTS OF NW KANSAS/SW
NEBRASKA WILL REACH LOWS NEAR OR BELOW ZERO...APPROACHING RECORD
COLD VALUES. A QUICK CHANCE FOR SNOWFALL DUE TO A NARROW BAND
ENHANCED FRONTOGENESIS AS SUGGESTED BY SHORT RANGE GUIDANCE. A FEW
SPOTS NEAR AND SOUTH OF I-70 COULD SEE UP TO AN INCH...BUT ANY
SNOWFALL THAT DOES FALL WILL BE QUICK TO EXIT. SNOWFALL AND CLOUD
COVER WILL LIMIT TEMPS IN THE EVENING HOURS...BUT ONCE THE SNOW
SHOWERS AND CLOUDS MOVE OUT TEMPERATURES WILL DROP RAPIDLY AS COLD
AIR PUSHES SOUTHWARD...850 TEMPS DROPPING TO NEAR -20 C...VERY COLD
EVEN BY WINTER STANDARDS. LOWS WILL BE NEAR TO BELOW
ZERO...APPROACHING RECORD VALUES FOR MANY LOCATIONS. COMBINED WITH
WINDS OF 20-25 MPH AM VERY CONFIDENT ADVISORY-LEVEL WIND CHILL
VALUES AS WIND CHILLS DROP TO -15 TO -25...ESPECIALLY IN EASTERN
COLORADO. IF SKIES CLEAR AS RAPID AS THE RUC IS INDICATING...EVEN
COLDER TEMPS/WIND CHILLS ARE POSSIBLE.
THURSDAY...COLD. HIGHS WILL STRUGGLE TO REACH THE TEENS...EVEN WITH
PARTIAL SUNSHINE. WINDS WILL BE LIGHT...WITH WIND CHILLS WILL BE
NEAR ZERO MUCH OF THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 223 PM MST WED DEC 4 2013
THURSDAY NIGHT-FRIDAY NIGHT...H5 LONGWAVE TROUGH WILL REMAIN IN
PLACE WITH ARCTIC AIR MASS AT THE SURFACE. LOOKS LIKE THERE WILL BE
VERY LITTLE CHANGE IN TEMPS WITH HIGHS IN THE TEENS AND LOWS AROUND
ZERO. MY CURRENT LOW TEMP FORECAST IS A CONSERVATIVE BLEND...AND IF
SKIES CLEAR NEAR DAYBREAK FRIDAY MORNING WE COULD SEE RECORD LOWS IN
THE -5 TO -15F BELOW ZERO RANGE. EVEN WITH SLIGHTLY WARMER TEMPS WE
WILL PROBABLY NEED TO CONSIDER WIND CHILL ADVISORIES BOTH NIGHTS.
MODELS SHOW SOME WEAK ENERGY ROTATING THROUGH THE BASE ON THE LARGE
SCALE TROUGH. BEYOND INCREASING CLOUD COVER THE FORECAST SHOULD
REMAIN DRY DURING THESE PERIODS. I DECIDED AGAINST MENTION OF
FLURRIES...THOUGH I COULDNT RULE OUT A FEW FLURRIES DURING THE
DAYTIME PERIOD THURSDAY IF WE ARE ABLE TO GET SOME WEAK INSTABILITY.
SATURDAY-SUNDAY NIGHT...THE NEXT GOOD CHANCE FOR ACCUMULATING SNOW
LOOKS TO ARRIVE THIS WEEKEND WHEN A SHORTWAVE TROUGH ORIGINATING
OVER THE PACIFIC NW MOVES TO THE FOUR CORNERS REGION SATURDAY AND
ACROSS THE PLAINS AS A NEGATIVELY TILTED TROUGH SUNDAY. VERY GOOD
FORCING AHEAD OF THIS FEATURE AND DECENT MOISTURE ADVECTION SHOULD
COMBINE TO PRODUCE ACCUMULATING SNOW FOR A LARGE PORTION OF THE
PLAINS. MODELS GENERALLY SHOW SIMILAR TIMING ON THIS
FEATURE...HOWEVER THERE IS LESS CONTINUITY ON THE TRACK AND THIS
WILL HAVE A LARGE IMPACT ON SNOW TOTALS OVER OUR CWA. DURING THIS
FORECAST UPDATE I BUMPED POPS UP SOME ON SATURDAY NIGHT AND SUNDAY
TO HIGH CHANCE CATEGORY WITH INCREASING CONFIDENCE IN MEASURABLE
SNOW. BEST GUESS BASED ON A MEAN STORM TRACK PUTS SNOW AMOUNTS IN
THE 1-3" RANGE OVER OUR CWA WITH THE HIGHEST AMOUNTS ACROSS THE
SOUTHEAST WHERE BETTER FORCING ASSOCIATED WITH MID LEVEL
FRONTOGENETICAL BAND HAS A BETTER CHANCE OF SETTING UP.
MONDAY-WEDNESDAY...DRY FORECAST IS EXPECTED WITH UPPER LEVEL
CONFLUENCE AND H5 PATTERN BECOMING SLIGHTLY MORE ZONAL. MODELS DO
ADVERTISE A GRADUAL WARMING TREND WITH HIGHS FINALLY APPROACHING (OR
GOING ABOVE) FREEZING BY TUESDAY AND WEDNESDAY. NORTHERN JET STREAM
STILL APPEARS TO BE VERY ACTIVE HOWEVER SO ADDITIONAL REINFORCING
SHOTS OF COLD AIR COULD KEEP OUR TEMPERATURES BELOW NORMAL THROUGH
NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1048 AM MST WED DEC 4 2013
MVFR TO IFR CONDITIONS EXPECTED WITHIN THE TAF PERIOD AT MCK AND
GLD. WINDS 20-25 KTS THIS AFTERNOON OUT OF THE NORTHWEST AT BOTH
SITES WILL DECREASE DRAMATICALLY THIS EVENING AND THROUGH THE REST OF
THE TAF PERIOD.
A LIGHT BUT VISIBILITY-REDUCING BAND OF SNOW IS APPROACHING
GLD...AND WHILE ITS APPEARANCE IS MEAGER ON RADAR AND
SATELLITE...OBS AT KITR INDICATED REDUCTION TO IFR CONDITIONS. FOR
THIS REASON HAVE A TEMPO FOR GLD FOR A QUICK BAND OF
SNOW...OTHERWISE VFR CONDITIONS THROUGH THE EARLY AFTERNOON WHEN
ANOTHER ROUND OF SNOWFALL IS EXPECTED TO IMPACT THE SITE. THIS
SECOND ROUND WILL BE RELATIVELY QUICK...ENDING LATE THIS EVENING.
VFR CONDITIONS THROUGH THE REST OF THE PERIOD AS CEILING HEIGHTS
RISE.
AT MCK SOME CLEARING ON SATELLITE AT THE 17Z HOUR...BUT ASOS
REPORTING AN MVFR CLOUD DECK STILL IN PLACE. REGARDLESS...SOME
CLEARING IS EXPECTED IN THE SHORT TERM BEFORE VFR CLOUD COVER
RETURNS. CONDITIONS WILL BE VFR FOR THE REST OF THE PERIOD.
&&
.CLIMATE...
ISSUED AT 223 PM MST WED DEC 4 2013
LOW TEMPERATURES WILL APPROACH RECORD VALUES TONIGHT.
CURRENT DAILY RECORD LOWS FOR THURSDAY (DEC 5)...
GOODLAND.....-8 (1972)
HILL CITY....-5 (1909)
BURLINGTON...-11 (1972)
MCCOOK.......-10 (1909)
YUMA.........-5
TRIBUNE......-2
COLBY........-8
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND CHILL ADVISORY UNTIL 11 AM MST /NOON CST/ THURSDAY FOR
KSZ001>003-013-014-027.
CO...WIND CHILL ADVISORY UNTIL 11 AM MST THURSDAY FOR COZ090>092.
NE...WIND CHILL ADVISORY UNTIL 11 AM MST /NOON CST/ THURSDAY FOR
NEZ079>081.
&&
$$
SHORT TERM...JJM
LONG TERM...DR
AVIATION...JJM
CLIMATE...JJM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
227 PM MST WED DEC 4 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 223 PM MST WED DEC 4 2013
ARCTIC COLD HAS ENTERED THE CWA AND IS EXPECTED TO STICK AROUND FOR
A WHILE. SOME LIGHT SNOW FELL THIS MORNING...WITH HEAVIEST BANDS
OVER EASTERN COLORADO BRINGING NEARLY AN INCH IN A FEW SPOTS.
TONIGHT ANOTHER ROUND OF SNOWFALL IS EXPECTED WHICH COULD BRING A
QUICK INCH IN A FEW SPOTS...BUT OTHERWISE THE COLD WILL BE THE MAIN
HAZARD IN THE SHORT TERM.
TODAY...SUBSIDENCE ACROSS THE TRI-STATE LEAD TO SNOWFALL ENDING AND
EVEN SOME CLEARING SKIES...AND HIGHS WERE A CHALLENGE OF BALANCING
THE ADDITIONAL SOLAR RADIATION WITH COLD AIR ADVECTION. WINDS ARE A
BIT STRONGER THAN THE ORIGINAL FORECAST...BUT A BLEND OF 12Z MOS
GUIDANCE HANDLED THE STRONGER WINDS A LITTLE BETTER THAN MOST OF THE
OTHER GUIDANCE.
TONIGHT...MUCH OF EASTERN COLORADO AND PARTS OF NW KANSAS/SW
NEBRASKA WILL REACH LOWS NEAR OR BELOW ZERO...APPROACHING RECORD
COLD VALUES. A QUICK CHANCE FOR SNOWFALL DUE TO A NARROW BAND
ENHANCED FRONTOGENESIS AS SUGGESTED BY SHORT RANGE GUIDANCE. A FEW
SPOTS NEAR AND SOUTH OF I-70 COULD SEE UP TO AN INCH...BUT ANY
SNOWFALL THAT DOES FALL WILL BE QUICK TO EXIT. SNOWFALL AND CLOUD
COVER WILL LIMIT TEMPS IN THE EVENING HOURS...BUT ONCE THE SNOW
SHOWERS AND CLOUDS MOVE OUT TEMPERATURES WILL DROP RAPIDLY AS COLD
AIR PUSHES SOUTHWARD...850 TEMPS DROPPING TO NEAR -20 C...VERY COLD
EVEN BY WINTER STANDARDS. LOWS WILL BE NEAR TO BELOW
ZERO...APPROACHING RECORD VALUES FOR MANY LOCATIONS. COMBINED WITH
WINDS OF 20-25 MPH AM VERY CONFIDENT ADVISORY-LEVEL WIND CHILL
VALUES AS WIND CHILLS DROP TO -15 TO -25...ESPECIALLY IN EASTERN
COLORADO. IF SKIES CLEAR AS RAPID AS THE RUC IS INDICATING...EVEN
COLDER TEMPS/WIND CHILLS ARE POSSIBLE.
THURSDAY...COLD. HIGHS WILL STRUGGLE TO REACH THE TEENS...EVEN WITH
PARTIAL SUNSHINE. WINDS WILL BE LIGHT...WITH WIND CHILLS WILL BE
NEAR ZERO MUCH OF THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 223 PM MST WED DEC 4 2013
THURSDAY NIGHT-FRIDAY NIGHT...H5 LONGWAVE TROUGH WILL REMAIN IN
PLACE WITH ARCTIC AIR MASS AT THE SURFACE. LOOKS LIKE THERE WILL BE
VERY LITTLE CHANGE IN TEMPS WITH HIGHS IN THE TEENS AND LOWS AROUND
ZERO. MY CURRENT LOW TEMP FORECAST IS A CONSERVATIVE BLEND...AND IF
SKIES CLEAR NEAR DAYBREAK FRIDAY MORNING WE COULD SEE RECORD LOWS IN
THE -5 TO -15F BELOW ZERO RANGE. EVEN WITH SLIGHTLY WARMER TEMPS WE
WILL PROBABLY NEED TO CONSIDER WIND CHILL ADVISORIES BOTH NIGHTS.
MODELS SHOW SOME WEAK ENERGY ROTATING THROUGH THE BASE ON THE LARGE
SCALE TROUGH. BEYOND INCREASING CLOUD COVER THE FORECAST SHOULD
REMAIN DRY DURING THESE PERIODS. I DECIDED AGAINST MENTION OF
FLURRIES...THOUGH I COULDNT RULE OUT A FEW FLURRIES DURING THE
DAYTIME PERIOD THURSDAY IF WE ARE ABLE TO GET SOME WEAK INSTABILITY.
SATURDAY-SUNDAY NIGHT...THE NEXT GOOD CHANCE FOR ACCUMULATING SNOW
LOOKS TO ARRIVE THIS WEEKEND WHEN A SHORTWAVE TROUGH ORIGINATING
OVER THE PACIFIC NW MOVES TO THE FOUR CORNERS REGION SATURDAY AND
ACROSS THE PLAINS AS A NEGATIVELY TILTED TROUGH SUNDAY. VERY GOOD
FORCING AHEAD OF THIS FEATURE AND DECENT MOISTURE ADVECTION SHOULD
COMBINE TO PRODUCE ACCUMULATING SNOW FOR A LARGE PORTION OF THE
PLAINS. MODELS GENERALLY SHOW SIMILAR TIMING ON THIS
FEATURE...HOWEVER THERE IS LESS CONTINUITY ON THE TRACK AND THIS
WILL HAVE A LARGE IMPACT ON SNOW TOTALS OVER OUR CWA. DURING THIS
FORECAST UPDATE I BUMPED POPS UP SOME ON SATURDAY NIGHT AND SUNDAY
TO HIGH CHANCE CATEGORY WITH INCREASING CONFIDENCE IN MEASURABLE
SNOW. BEST GUESS BASED ON A MEAN STORM TRACK PUTS SNOW AMOUNTS IN
THE 1-3" RANGE OVER OUR CWA WITH THE HIGHEST AMOUNTS ACROSS THE
SOUTHEAST WHERE BETTER FORCING ASSOCIATED WITH MID LEVEL
FRONTOGENETICAL BAND HAS A BETTER CHANCE OF SETTING UP.
MONDAY-WEDNESDAY...DRY FORECAST IS EXPECTED WITH UPPER LEVEL
CONFLUENCE AND H5 PATTERN BECOMING SLIGHTLY MORE ZONAL. MODELS DO
ADVERTISE A GRADUAL WARMING TREND WITH HIGHS FINALLY APPROACHING (OR
GOING ABOVE) FREEZING BY TUESDAY AND WEDNESDAY. NORTHER JET STREAM
STILL APPEARS TO BE VERY ACTIVE HOWEVER SO ADDITIONAL REINFORCING
SHOTS OF COLD AIR COULD KEEP OUR TEMPERATURES BELOW NORMAL THROUGH
NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1048 AM MST WED DEC 4 2013
MVFR TO IFR CONDITIONS EXPECTED WITHIN THE TAF PERIOD AT MCK AND
GLD. WINDS 20-25 KTS THIS AFTERNOON OUT OF THE NORTHWEST AT BOTH
SITES WILL DECREASE DRAMATICALLY THIS EVENING AND THROUGH THE REST OF
THE TAF PERIOD.
A LIGHT BUT VISIBILITY-REDUCING BAND OF SNOW IS APPROACHING
GLD...AND WHILE ITS APPEARANCE IS MEAGER ON RADAR AND
SATELLITE...OBS AT KITR INDICATED REDUCTION TO IFR CONDITIONS. FOR
THIS REASON HAVE A TEMPO FOR GLD FOR A QUICK BAND OF
SNOW...OTHERWISE VFR CONDITIONS THROUGH THE EARLY AFTERNOON WHEN
ANOTHER ROUND OF SNOWFALL IS EXPECTED TO IMPACT THE SITE. THIS
SECOND ROUND WILL BE RELATIVELY QUICK...ENDING LATE THIS EVENING.
VFR CONDITIONS THROUGH THE REST OF THE PERIOD AS CEILING HEIGHTS
RISE.
AT MCK SOME CLEARING ON SATELLITE AT THE 17Z HOUR...BUT ASOS
REPORTING AN MVFR CLOUD DECK STILL IN PLACE. REGARDLESS...SOME
CLEARING IS EXPECTED IN THE SHORT TERM BEFORE VFR CLOUD COVER
RETURNS. CONDITIONS WILL BE VFR FOR THE REST OF THE PERIOD.
&&
.CLIMATE...
ISSUED AT 223 PM MST WED DEC 4 2013
LOW TEMPERATURES WILL APPROACH RECORD VALUES TONIGHT.
CURRENT DAILY RECORD LOWS FOR THURSDAY (DEC 5)...
GOODLAND.....-8 (1972)
HILL CITY....-5 (1909)
BURLINGTON...-11 (1972)
MCCOOK.......-10 (1909)
YUMA.........-5
TRIBUNE......-2
COLBY........-8
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND CHILL ADVISORY UNTIL 11 AM MST /NOON CST/ THURSDAY FOR
KSZ001>003-013-014-027.
CO...WIND CHILL ADVISORY UNTIL 11 AM MST THURSDAY FOR COZ090>092.
NE...WIND CHILL ADVISORY UNTIL 11 AM MST /NOON CST/ THURSDAY FOR
NEZ079>081.
&&
$$
SHORT TERM...JJM
LONG TERM...DR
AVIATION...JJM
CLIMATE...JJM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
222 PM CST Wed Dec 4 2013
...Update to long term discussion...
.SYNOPSIS...
ISSUED AT 1102 AM CST WED DEC 4 2013
At 12z Wednesday a 300mb jet extended from southern California
into far western Nebraska. A -35c to -37c 500mb low was located
over southeastern Idaho with an upper level trough extending
southwest of this upper low into southern California. Ahead of
this upper level trough 80 to 90meter 12hour height rises were
observed near the four corners region which was where the left
exit region of a 300mb +100kt jet was positioned. A 700mb
baroclinic zone stretched from the four corners region across
western Kansas and into southeastern Nebraska with an area of
higher dewpoints observed along this baroclinic zone. The 850mb
temperatures at 12z Wednesday across the central plains varied
from -3c at Amarillo to -9c at Dodge city to -16c at North Platte.
This a 18c to 25c drop when comparing the 850mb temperatures from 12z
Wednesday to 12z Tuesday. Dodge City and North Platte soundings
from 12z also indicated a fairly deep layer of moisture which
extended from near the surface to at least the 800mb level.
&&
.SHORT TERM...(This evening through Thursday)
ISSUED AT 147 PM CST WED DEC 4 2013
19z visible satellite loop indicating some clearing skies across
western Kansas as the low clouds gradually erode. Further west mid
level cloud cover/moisture was on the increase and this appears to
be related to a 700mb baroclinic zone that extended from northeast
Colorado into Nebraska. Tonight 700mb frontogenesis will be
improving along this mid level baroclinic zone as the right
entrance region of a 300mb jet crosses western Kansas. Based on
the NAM and RAP at 18z Wednesday this 700mb baroclinic zone should
be located across northeast Colorado 18z and based on the latest
composite mosaic radar loop these models appear to have a decent
handle on this. As a result will follow the 700mb baroclinic zone
from NAM and RAP overnight and place the better chances for
measurable snow along this boundary given the improving
frontogenesis and the location of the right entrance region of an
upper level jet as it crosses the central plains during the
overnight hours.
Initial thoughts for snow amounts tonight...a brief period of
steady light to even moderate snow may accompany the jet steak
which may result in a quick inch of snow across portions of west
central and north central Kansas. Have therefore place snow
accumulations of 1 to around 1.5 inches in this this area between
00z Thursday and 12z Thursday. Further south some light
snow/flurries will still be possible, however given the loss of
the upper level dynamics lower snow amounts are anticipated.
On Thursday the better mid level forcing will be located near the
Oklahoma border through much of the day as a southern branch upper
level disturbance approaches southwest Kansas from New Mexico.
Another brief period of steady light to moderate snow will be be
possible during the day across far southwest Kansas and near the
Oklahoma border. Once again 1 to 2 inches of snowfall will be
possible with this steadier snow and lower snow amounts further
north. At this time snow totals over the next 24 to 36 hours are
expected to be mainly between 1 to 2 inches so inserted these snow
totals into the hazardous weather outlook but will not issue a
winter weather advisory at this time.
Wind chill values towards daybreak will fall back mainly into the
5 to 10 degrees below zero range with wind chill readings
approaching -15c in a few locations of west central Kansas. On
Thursday as afternoon temperatures struggle to reach the 15 to
near 20 degree range the wind chill values are expected to be
mainly in the single digits.
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 222 PM CST WED DEC 4 2013
Thursday night/Friday:
Precipitation will be quickly diminishing after 00Z Friday as the 700
hPa frontogenesis and 285 Kelvin isentropic lift slides off to the southeast.
Minimums will continue to be cold and in the single digits. will have
to watch out for the possible need for a wind chill advisory as apparent
temperatures approach -15F, particularly during the morning on Friday.
Otherwise, a precipitation free forecast is expected Friday as isentropic
downglide develops in the wake of the passing synoptic trof. Maximums
Friday will be in the teens and have gone with the colder bias correct
guidance as 850 hPa temperatures remain 2 to 3 standard deviations below
normal.
Saturday and beyond:
250 hPa flow will eventually transition from westerly Saturday to southwesterly
Sunday as the next 400 hPa pv anomaly moves across the central Rockies
and eventually ejects out across the prairies. This signature is quite
impressive per ECMWF fields and displays the classic treble clef signature.
At the low levels, 850-600 hPa frontogenesis and 280-290 Kelvin isentropic
lift develops across west central Kansas Sunday. Have ramped up precipitation
probabilities in this region during the day. The GEM and ECMWF indicate
the potential for a low end snow advisory for Sunday. This is something
to continue to watch as we get closer to the event. Otherwise, the rest
of the forecast will feature fairly tranquil weather and cold temperatures.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 1102 AM CST WED DEC 4 2013
BUFR soundings indicating the MVFR cigs, as of 16z, will be
gradually improving to low VFR conditions at all three taf sites
around 21z. These low VFR cigs are then expected to linger through
the overnight period with a chance of light snow developing after
midnight as an area of mid level forcing moves across western
Kansas. At this time the better opportunity for snow at HYS and
GCK will be from 06z to 12z and DDC from around 12z to 18z. Gusty
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 9 16 6 16 / 30 60 60 0
GCK 9 16 4 14 / 50 40 40 0
EHA 7 14 5 15 / 50 50 50 0
LBL 11 17 7 16 / 40 80 80 0
HYS 8 18 1 15 / 60 20 20 0
P28 14 22 11 19 / 20 50 50 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burgert
LONG TERM...Sugden
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
150 PM CST Wed Dec 4 2013
...Updated short term discussion...
.SYNOPSIS...
ISSUED AT 1102 AM CST WED DEC 4 2013
At 12z Wednesday a 300mb jet extended from southern California
into far western Nebraska. A -35c to -37c 500mb low was located
over southeastern Idaho with an upper level trough extending
southwest of this upper low into southern California. Ahead of
this upper level trough 80 to 90meter 12hour height rises were
observed near the four corners region which was where the left
exit region of a 300mb +100kt jet was positioned. A 700mb
baroclinic zone stretched from the four corners region across
western Kansas and into southeastern Nebraska with an area of
higher dewpoints observed along this baroclinic zone. The 850mb
temperatures at 12z Wednesday across the central plains varied
from -3c at Amarillo to -9c at Dodge city to -16c at North Platte.
This a 18c to 25c drop when comparing the 850mb temperatures from 12z
Wednesday to 12z Tuesday. Dodge City and North Platte soundings
from 12z also indicated a fairly deep layer of moisture which
extended from near the surface to at least the 800mb level.
&&
.SHORT TERM...(This evening through Thursday)
ISSUED AT 147 PM CST WED DEC 4 2013
19z visible satellite loop indicating some clearing skies across
western Kansas as the low clouds gradually erode. Further west mid
level cloud cover/moisture was on the increase and this appears to
be related to a 700mb baroclinic zone that extended from northeast
Colorado into Nebraska. Tonight 700mb frontogenesis will be
improving along this mid level baroclinic zone as the right
entrance region of a 300mb jet crosses western Kansas. Based on
the NAM and RAP at 18z Wednesday this 700mb baroclinic zone should
be located across northeast Colorado 18z and based on the latest
composite mosaic radar loop these models appear to have a decent
handle on this. As a result will follow the 700mb baroclinic zone
from NAM and RAP overnight and place the better chances for
measurable snow along this boundary given the improving
frontogenesis and the location of the right entrance region of an
upper level jet as it crosses the central plains during the
overnight hours.
Initial thoughts for snow amounts tonight...a brief period of
steady light to even moderate snow may accompany the jet steak
which may result in a quick inch of snow across portions of west
central and north central Kansas. Have therefore place snow
accumulations of 1 to around 1.5 inches in this this area between
00z Thursday and 12z Thursday. Further south some light
snow/flurries will still be possible, however given the loss of
the upper level dynamics lower snow amounts are anticipated.
On Thursday the better mid level forcing will be located near the
Oklahoma border through much of the day as a southern branch upper
level disturbance approaches southwest Kansas from New Mexico.
Another brief period of steady light to moderate snow will be be
possible during the day across far southwest Kansas and near the
Oklahoma border. Once again 1 to 2 inches of snowfall will be
possible with this steadier snow and lower snow amounts further
north. At this time snow totals over the next 24 to 36 hours are
expected to be mainly between 1 to 2 inches so inserted these snow
totals into the hazardous weather outlook but will not issue a
winter weather advisory at this time.
Wind chill values towards daybreak will fall back mainly into the
5 to 10 degrees below zero range with wind chill readings
approaching -15c in a few locations of west central Kansas. On
Thursday as afternoon temperatures struggle to reach the 15 to
near 20 degree range the wind chill values are expected to be
mainly in the single digits.
.LONG TERM...(Thursday through Tuesday)
ISSUED AT 345 AM CST WED DEC 4 2013
Medium range models indicate an upper level shortwave pushing east
across the Four Corners Region Thursday setting up the possibility
for precip across portions of western Kansas. As the system
approaches, a series of H5 vort maxes will continue to lift
northeast out of the trough axis in the Desert Southwest and across
the Western High Plains. Meanwhile, an upper level jet exiting the
trough axis will intensify as it climbs northeast across western
Kansas and the panhandles of Texas and Oklahoma. Additionally, the
GFS/ECMWF continue to hint at some H7 frontogenesis bands
transitioning across western Kansas throughout the day. As a
result, enough support will exist to support periods of light snow
across portions of west central, southwest, and central Kansas as
mid/upper level moisture increases somewhat. However, significant
snowfall amounts are still not expected across much of the area
with amounts generally less than 2 inches. Localized higher
amounts cannot be ruled out across extreme southwest Kansas but
confidence is too low to consider issuing any winter weather
headlines. Drier conditions are then expected Friday through
Saturday afternoon as the upper level shortwave opens up and races
off to the northeast. Another round of light precip is possible
Saturday night into Sunday as another upper level trough drops
south out of the Pacific Northwest into the Four Corners Region.
Temperatures will be well below normal Thursday as cold air
continues to filter southward into western Kansas. Surface high
pressure will extend from the high plains of eastern Montana and
eastern Wyoming down into Nebraska and Kansas helping to reinforce
the cold air mass in place across the Western High Plains with H85
temperatures as low as 15C below. Look for highs only up into the
teens(F) and lower 20s(F) Thursday. Similar temperatures are likely
Friday and Saturday with little change in the overall air mass going
into the weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 1102 AM CST WED DEC 4 2013
BUFR soundings indicating the MVFR cigs, as of 16z, will be
gradually improving to low VFR conditions at all three taf sites
around 21z. These low VFR cigs are then expected to linger through
the overnight period with a chance of light snow developing after
midnight as an area of mid level forcing moves across western
Kansas. At this time the better opportunity for snow at HYS and
GCK will be from 06z to 12z and DDC from around 12z to 18z. Gusty
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 9 16 6 16 / 30 60 60 0
GCK 9 16 4 14 / 50 40 40 0
EHA 7 14 5 15 / 50 50 50 0
LBL 11 17 7 16 / 40 80 80 0
HYS 8 18 1 15 / 60 20 20 0
P28 14 22 11 19 / 20 50 50 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burgert
LONG TERM...JJohnson
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS JACKSON KY
1259 PM EST WED DEC 4 2013
.UPDATE...
ISSUED AT 1100 AM EST WED DEC 4 2013
BASED ON LATEST TRENDS...INCLUDING A FEW MORE BREAKS IN THE
CLOUDS...HAVE INCREASED AFTERNOON MAXIMUM TEMPERATURES. WILL INCLUDE
SPRINKLES FOR THE START OF THE FORECAST PERIOD IN THE NORTH AND EAST.
HAVE UPDATED NDFD...WEB FORECASTS AND ZFP.
UPDATE ISSUED AT 853 AM EST WED DEC 4 2013
UPDATED NDFD...WEB FORECASTS AND ZFP TO INCLUDE ISOLATED SHOWERS THIS
MORNING ACROSS THE WESTERN AND CENTRAL PARTS OF THE FORECAST AREA.
THIS IS SUPPORTED BY CURRENT RADAR TRENDS AND LATEST HRRR GUIDANCE.
CURRENT EXPECTATIONS ARE FOR ISOLATED SHOWERS TO END BY EARLY AFTERNOON.
UPDATE ISSUED AT 651 AM EST WED DEC 4 2013
CLOUD COVER HAS PRETTY MUCH RETURNED ACROSS THE AREA AND SHOULD
PERSIST THROUGH A GOOD CHUNK OF THE DAY ONCE AGAIN AS A WARM FRONT
PUSHES NORTH TOWARDS THE AREA. SOME QUESTION AS TO IF THIS BOUNDARY
WILL CLEAR THE AREA BEFORE SUNSET. IF IT FAILS TO DO SO...CLOUD COVER
MAY HOLD FOR THE REMAINDER OF THE DAY. A FEW BREAKS CAN STILL BE
EXPECTED IN THE SOUTHEAST WITH DOWNSLOPING FLOW...BUT FOR THE MOST
PART...CLOUDY WILL BE THE WAY TO GO TODAY. COULD BE SOME VERY PATCHY
DRIZZLE OUT THERE THIS MORNING...BUT LIKELY CONFINED TO AREAS MORE
SOUTH AND WEST OF HERE. NO UPDATE PLANNED EARLY THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 308 AM EST WED DEC 4 2013
SATELLITE THIS MORNING REVEALS A STORM SYSTEM TAKING SHAPE OVER THE
NORTHERN PLAINS...WITH SOUTHERLY FLOW ACROSS THE MAJORITY OF THE
OHIO/TENNESSEE RIVER VALLEYS. WHILE WINDS REMAIN MOSTLY SOUTH...THERE
IS A SLIGHT EASTERLY COMPONENT TO THE WIND WHICH IS CONTINUING TO EAT
AWAY AT CLOUD COVER FROM TIME TO TIME OVER EASTERN KENTUCKY. THE
UNFAVORABLE DOWNSLOPING CONDITIONS WILL LIKELY BE OVERTAKEN THIS
MORNING AS A WARM FRONT LIFTS NORTH ACROSS THE AREA. THIS WILL YIELD
MOSTLY CLOUDY TO CLOUDY SKIES THROUGH A GOOD CHUNK OF THE DAY TODAY.
PREVIOUS THINKING WAS THE WARM FRONT WOULD SHOOT ON THROUGH...BUT NOW
LOOKS LIKE CLOUDS MAY HOLD OVER MUCH OF THE AREA THROUGH THE DAY.
THIS WILL LIKELY SUPPRESS TEMPERATURES. REGARDLESS...ADVECTION ALONE
SHOULD ALLOW TEMPERATURE TO CLIMB INTO THE LOW TO MID 60S. AREAS IN
THE SOUTHWEST HAVE A BETTER CHANCE OF CLEARING AND WE COULD SEE SOME
READINGS GETTING CLOSE TO 70. CLOUDS SHOULD CONTINUE ERODING INTO
TONIGHT...BUT SOUTHERLY WINDS ARE EXPECTED TO REMAIN IN TACT TONIGHT
WITH A GOOD GRADIENT. THIS WILL ALLOW OVERNIGHT LOWS TO REMAIN VERY
MILD WITH READINGS IN THE 50S (HIGHER THAN OUR AVERAGE HIGHS FOR THIS
TIME OF YEAR).
BY LATE TONIGHT...AND ESPECIALLY TOMORROW...ISENTROPIC ASCENT WILL
KICK INTO FULL GEAR WITH PRECIPITATION DEVELOPING ACROSS CENTRAL AND
EASTERN KENTUCKY. MODELS HAVE SLOWED DOWN THE ADVANCING COLD
FRONT...SO HAVE SLOWED DOWN PRECIPITATION CHANCES. IT DOES LOOK LIKE
PRECIPITATION SHOULD EASILY IMPACT THE I-75 CORRIDOR ON THURSDAY...BUT
RAIN MAY MAKE IT AS FAR AS FAR EASTERN KENTUCKY BY LATE IN THE DAY.
REGARDLESS...CONFIDENCE IS NOT AS HIGH IN THE EAST...SO HAVE GONE
WITH AN EAST TO WEST GRADIENT IN POPS. INITIAL RAINFALL TOTALS ON
THURSDAY ARE NOT EXPECTED TO BE TOO HIGH GIVEN THE INITIAL DRY AIR
TO OVERCOME. HOWEVER...SOME TOTALS NEAR A HALF INCH MAY BE POSSIBLE
NEAR THE I-75 CORRIDOR BY LATE IN THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 440 AM EST WED DEC 4 2013
EXCESSIVE RAINFALL STILL LOOKS ON TRACK THROUGH EARLY NEXT
WEEK...ALTHOUGH MODEL GUIDANCE HAS TRENDED A BIT LEANER WITH THE
FIRST BATCH OF RAINFALL...WITH 2 TO 2.5 INCHES OF RAIN SUGGESTED
NOW...AND THEN SIMILAR TOTALS OCCURRING FROM SUNDAY THROUGH MONDAY.
THIS WOULD YIELD 4 DAY TOTALS IN THE 4 TO 5 INCH RANGE...WITH LARGER
CREEKS...STREAMS...AND RIVERS SEEING THE BEST CHANCE OF FLOODING
GIVEN THE LONG DURATION OF THE PRECIPITATION. WILL CONTINUE TO
HIGHLIGHT THESE CONCERNS IN AN ONGOING HYDROLOGIC OUTLOOK.
THE COLD FRONT WILL HAVE SETTLED JUST OFF TO THE SOUTHEAST OF OUR
AREA THURSDAY NIGHT. IT WILL CONTINUE TO SAG SOUTHEAST AND PIVOT A
BIT MORE AS SURFACE WAVES TRAVERSE THE BOUNDARY. THE RAIN MAY FALL
HEAVY AT TIMES THURSDAY NIGHT AND PARTICULARLY FRIDAY AS THE
STRONGEST UPPER LEVEL JET MOVES THROUGH THE GREAT LAKES AND LEAVES
MUCH OF THE OHIO VALLEY IN A FAVORABLE RIGHT ENTRANCE REGION.
SOME LIGHT SLUSHY ACCUMULATION STILL LOOKS LIKE A POSSIBILITY
GENERALLY ALONG AND NORTH OF THE MOUNTAIN PARKWAY. THE COLD AIR
ADVECTION HAS TRENDED A BIT QUICKER...SO THERE MAY BE A 1 TO 2 HOUR
WINDOW OF DECENT ENOUGH SNOWFALL RATES TO OVERCOME THE WARM GROUND
TEMPERATURES TEMPORARILY HEADING INTO DUSK. WILL AWAIT FURTHER MODEL
CONSISTENCY BEFORE DRAWING MORE ATTENTION TO THIS POTENTIAL AS IMPACT
OVERALL STILL LOOKS ON THE LOW SIDE.
PRECIPITATION WILL TAPER OFF QUICKLY FRIDAY NIGHT FROM NORTHWEST TO
SOUTHEAST AS COLDER AND MUCH DRIER AIR ADVECT IN FROM HIGH PRESSURE
SETTLING IN ACROSS THE PLAINS. DRY AND MUCH COLDER WEATHER IS
EXPECTED FOR SATURDAY...WITH HIGHS RANGING FROM THE LOWER 30S NORTH
OF I-64...TO THE LOWER 40S BORDERING TENNESSEE.
THE NEXT PRECIPITATION EVENT WILL THEN THREATEN EASTERN KENTUCKY BY
SATURDAY NIGHT...AS AN INVERTED SURFACE TROUGH BECOMES RE-ESTABLISHED
ACROSS THE LOWER MISSISSIPPI VALLEY. THE PRECIPITATION WILL BEGIN AS
SNOW ESPECIALLY NORTH OF THE HAL ROGERS PARKWAY AND HIGHWAY 80
CORRIDORS...HOWEVER THE WARM NOSE LOOKS TO OVERWHELM THE COLD AIR
QUICKLY...SO IT LOOKS TO BE ANOTHER MORE LIMITED WINDOW OF SNOW AND
POSSIBLY AN ALTERNATIVE TYPE OF PRECIPITATION DEPENDING ON HOW COLD
IT CAN GET SATURDAY NIGHT AND THE FURTHER EVOLUTION OF THE SYSTEM.
EXPECT A TRANSITION TO ALL RAIN THROUGH SUNDAY...AS A MORE ROBUST
SURFACE WAVE DEVELOPS ALONG THE BOUNDARY IN THE GULF AND HEADS
NORTHEAST. THIS SURFACE LOW WILL CONTINUE TO DEEPEN AS IT HEADS INTO
THE GREAT LAKES BY MONDAY. THE HEAVIEST RAIN LOOKS TO FALL ACROSS
EASTERN KENTUCKY SUNDAY NIGHT INTO MONDAY AS UPPER LEVEL DYNAMICS ARE
MAXIMIZED ONCE AGAIN ACROSS THE OHIO VALLEY. MUCH COLDER AIR WILL
MOVE IN BEHIND THE COLD FRONT...ONCE IT GETS DRAGGED TOWARDS THE
EASTERN SEABOARD LATE MONDAY. EXPECT SOME BACKSIDE SNOW ONCE
AGAIN...HOWEVER WITH DEEPER MOISTURE EXITING...AM ONLY SEEING LIGHT
ACCUMULATIONS RIGHT NOW. TUESDAY HIGHS WILL STRUGGLE TO REACH THE
FREEZING MARK AT MOST LOCATIONS...WITH DRY WEATHER RETURNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1259 PM EST WED DEC 4 2013
BROKEN TO OVERCAST SKIES WITH MAINLY VFR CEILINGS..AND SOME PATCHY
MVFR CEILINGS WILL PERSIST ACROSS THE REGION THROUGH THE DAY. A WARM
FRONT WILL LIFT NORTH ACROSS THE REGION THIS AFTERNOON...WITH SOME
GUSTY SOUTH WINDS EXPECTED AT LOZ AND SME. AFTER THE WARM FRONT
PASSES NORTH...WARM MOIST AIR WILL CONTINUE TO SPREAD INTO THE
FORECAST AREA WITH CEILINGS EXPECTED TO LOWER TO MVFR LATE TONIGHT
AND EARLY THURSDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON
THURSDAY...WITH RAIN CHANCES INCREASING FROM THE AFTERNOON INTO THE
NIGHT. STILL POSSIBLE SOME LOW LEVEL WIND SHEAR COULD DEVELOP TONIGHT
AND THIS WILL NEED TO BE MONITORED.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...KAS
LONG TERM...GEOGERIAN
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
457 PM EST WED DEC 4 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 400 PM EST WED DEC 4 2013
20Z SFC CHART INDICATES ELONGATED SFC TROUGH FROM WCNTRL WI INTO
NORTHEAST IA WITH MSLP OF 998MB. WV AND RUC FCST SHOWS SHORTWAVE
PUSHING ACROSS SOUTHERN MINNESOTA. WAVE IS EXPECTED TO LIFT TOWARD
NORTHWEST WI WHILE DEEPENING OVERNIGHT. WARM AIR ADVECTION IN FULL
SWING AHEAD OF MAINLY 850MB LOW LIFTING INTO NW WISCONSIN. RUC13 AND
NAM12 HAVE DONE NICE JOB WITH THE WARM LAYER AT H9-H85 TODAY AND
BOTH SHOW H85 TEMPS OVER 2C REACHING NORTH OF ALL CWA BY 00Z.
SOUNDINGS OVER US CURRENTLY WOULD SUGGEST MAINLY FZRA BUT LINGERING
COLD POCKET NEAR SFC /TEMPS STILL IN MID-UPR 20S/ IS ALLOWING SLEET
TO HANG ON LONGER. CURRENTLY SNOW IS STILL FALLING OVER KEWEENAW
PENINSULA BUT IS EVEN STARTING TO MIX WITH FREEZING RAIN AND SLEET
OVER PORTIONS OF WESTERN UPR MICHIGAN. PLAN FOR EVENING IS THAT
MIXED FREEZING RAIN/SLEET/SNOW WILL CHANGE TO MAINLY FREEZING RAIN
AND SLEET WHILE MOSTLY FREEZING RAIN OR EVEN JUST RAIN OCCURS FOR
CNTRL CWA...ESPECIALLY CLOSER TO LK MICHIGAN SHORE. IF HEAVIER
PRECIP WAS EXPECTED OVR CNTRL THIS EVENING...ICING COULD BE BIGGER
ISSUE. RIGHT NOW...APPEARS THAT HEAVIER PRECIP IS GOING TO OCCUR IN
STRIPE FROM SOUTHERN MINNESOTA TOWARD WESTERN LK SUPERIOR IN AREAS
OF STRONGEST PVA/DIVERGENCE ALOFT JUST AHEAD OF TRACK OF SHORTWAVE.
GIVEN TREND TO MORE FZRA THOUGH...INCREASED ICE ACCUMS OVER INTERIOR
WEST AND CNTRL TO 0.10-0.20 INCHES THROUGH THE EVENING.
AS MID-LEVEL DRYING IN THE H7-H6 LAYER ARRIVES 03Z-06Z OVER THE
SOUTH AND AFTER 06Z IN THE NORTH...EXPECT WINTRY MIX OF PRECIP TO
TAPER OFF TO MORE OF A DRIZZLE/FREEZING DRIZZLE. ACTUALLY HEADLINES
SO FAR ARE WORKING OUT PRETTY WELL. DID HAVE TO GO WITH MORE SLEET
AND FREEZING RAIN AS WARM AIR WORKED IN QUICKER...BUT OVERALL IDEA
OF WINTRY MIX IS COVERED WITH GOING WINTER WEATHER ADVY. TIMING FOR
ENDING OF ADVY SEEMS GOOD AS WELL. ONLY POSSIBLE TROUBLE SPOTS WILL
IN THE INTERIOR CNTRL AND EAST THIS EVENING DUE TO ICING IF HEAVIER
PRECIP ENDS UP BLOSSOMING TO THE EAST OF PRIMARY SHORTWAVE. SOME
SHORT TERM HIGHER-RES MODELS INDICATE EXPANSION OF PRECIP OVER
SCNTRL THIS EVENING...BUT RADAR TRENDS UPSTREAM NOT REALLY SHOWING
THIS. IF SFC TEMPS STAY BLO FREEZING THAT AREA WILL NEED TO BE
WATCHED FOR POSSIBLE ADVY.
NOW ONTO LATE TONIGHT AND THURSDAY. MAIN ISSUE SEEMS TO BE LK EFFECT
AND BLOWING SNOW ON THE KEWEENAW. WEST WINDS MAY GUST OVER 40 MPH AT
TIMES LEADING TO THE BLSN/POOR VISIBILITY...PROBABLY 1/4-1/2SM AT
TIMES OVER PORTIONS OF THE KEWEENAW. LARGER SCALE FORCING BECOMES
NEGATIVE BUT THERE IS A LOT OF LINGERING MOISTURE BLO H8 WITH
COOLING AT INVERSION TOP TO -16C OR SO BY MIDDAY. GIVEN LK SUPERIOR
WATER TEMPS AROUND 3-4C THIS GIVES MORE THAN SUFFICIENT OVER-WATER
INSTABILITY FOR AT LEAST MODERATE LK EFFECT SNOW SHOWERS. WSW WINDS
OVER LAND WITH MORE OF A WESTERLY WIND OVER LK SUPERIOR INDICATES
STRONGER CONVERGENCE AREA SETS UP ACROSS KEWEENAW. SNOW AMOUNTS WILL
BE HELD DOWN SOME BY LOWER SLR/S AS THERE IS A LOT OF FRACTURING OF
SNOWFLAKES DUE TO THE STRONG WINDS. EXPECT ADVY LEVEL SNOWS OF 3-5"
OR 4-7" WITH A LOT OF WIND/BLSN. WILL ISSUE A SEPARATE LAKE EFFECT
SNOW ADVY FOR LATE TONIGHT THROUGH THURSDAY...GOING INTO PLACE RIGHT
WHEN THE CURRENT WINTER WEATHER ADVY FOR THE MESSY MIX OF SNOW/SLEET
AND FREEZING RAIN DIMINISHES.
AND FINALLY FOR LATE TONIGHT INTO THURSDAY...AWAY FM THE
KEWEENAW...MAIN ISSUE WILL BE COLD AIR PUSHING IN FM THE WEST.
ALREADY SEEING THIS ARCTIC AIR POURING ACROSS THE DAKOTAS THIS AFTN.
EXPECT SLOWLY FALLING TEMPERATURES THROUGH THE DAY AS THE COLD WORKS
EAST...WITH READINGS LIKELY INTO THE UPPER SINGLE DIGITS BY EVENING
OVER THE FAR WEST CWA. THIS COLDER AIR WILL ALSO FREEZE ANY
LINGERING SLUSH AND WATER IS ON THE ROADS AND SIDEWALKS...WHICH
COULD RESULT IN TOUGHER TRAVEL CONDITIONS IN SPOTS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 456 PM EST WED DEC 4 2013
THE EASY PART OF THIS FCST PERIOD WILL BE THE LACK OF MIXED
PRECIPITATION. EXPECT ONLY SNOW...WITH SFC TEMPS MAXING OUT IN THE
LOW TO MID 20F DEGREE RANGE /MONDAY/ AND 850MB TEMPS TOPPING OUT
AROUND -15C EAST EARLY THURSDAY NIGHT...AND AGAIN SUNDAY THROUGH
MONDAY AROUND -12 TO -15C.
WILL CONTINUE TO HAVE LES OVER THE W HALF OF UPPER MI THURSDAY
NIGHT. AMOUNTS ARE STILL IN QUESTION. MAY NEED TO EXTEND THE CURRENT
LES ADVISORY FOR ANOTHER 6-12HRS IF THE 3-5IN OF SNOW FALL OVER
KEWEENAW...N HOUGHTON...AND FAR W ONTONAGON COUNTY THURSDAY NIGHT.
THE LES PARAMETER OFF THE GFS REMAINS AT OR ABOVE 2 THROUGH 06Z
FRIDAY. WILL LET LATER SHIFTS DISCUSS THE NEED...AS THE WINDS
DIMINISH SIGNIFICANTLY...BUT STILL GUSTING TO AROUND 20-25KTS
OVERNIGHT. THE WEAKENING SFC TROUGH WILL LINGER ACROSS THE UPPER
GREAT LAKES THROUGH SATURDAY...WITH WINDS SLOWLY MOVING MORE
OFFSHORE SATURDAY NIGHT. UNTIL THEN...LES WILL LINGER MAINLY ACROSS
THE KEWEENAW PENINSULA.
KEPT MENTION OF THE COLDEST TEMPS OF THE SEASON IN THE HWO FOR
THURSDAY NIGHT THROUGH SATURDAY MORNING. AT THIS POINT IT LOOKS LIKE
A WIND CHILL ADVISORY MAY NOT BE NEEDED FOR FRIDAY NIGHT INTO
SATURDAY MORNING...AS THE LOWEST VALUES FLIRT WITH -25C OVER THE SW
CORNER OF THE CWA.
STRONG SFC HIGH OVER SW CANADA FRIDAY WILL PUSH ACROSS THE NORTHERN
AND CENTRAL PLAINS FRIDAY NIGHT INTO EARLY SATURDAY...BEFORE
BUILDING ACROSS THE GREAT LAKES REGION. ENDED UP SPLITTING UP SOME
OF THE MORE EXTENDED POPS AS A RESULT...FOR SATURDAY THROUGH SUNDAY.
THE NEXT ROUND OF SNOW WILL SLIDE BACK IN SUNDAY NIGHT...WITH LIKELY
POPS OVER THE E HALF...AS THE HIGH EXITS ACROSS THE NEW ENGLAND
STATES AND LOW PRESSURE NEARS FROM THE LOWER AND CENTRAL MS VALLEY.
THE SFC LOW LOOKS TO CROSS LAKE HURON AROUND 12Z MONDAY...DEEPENING
AS IT MOVES TO S QUEBEC MONDAY AFTERNOON/EVENING. THIS WILL BRING
ABOUT ANOTHER ROUND OF W TO NW WINDS...WITH GALES AGAIN POSSIBLE
ACROSS LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1234 PM EST WED DEC 4 2013
A LOW PRESSURE SYSTEM WILL KEEP PRECIP AT THE TAF SITES INTO
TONIGHT. WARM AIR MOVING INTO THE REGION WILL SWITCH SNOW THIS
MORNING TO RAIN AND FREEZING RAIN AT TIMES INTO EARLY TONIGHT...MOST
LIKELY AT SAW AND MORE LIKELY TO STAY A WINTRY MIX AT IWD AND CMX.
LOTS OF DIFFICULTY FORECASTING EXACT CHANGE OVER TIMES...SO PUT BEST
GUESS INTO TAFS. PRECIP WILL CHANGE BACK TO SNOW TONIGHT AS COLD AIR
COMES IN BEHIND A COLD FRONT...WHILE PRECIP TRANSITIONS FROM AREA
WIDE PRECIP TO LAKE EFFECT SNOW...FAVORING IWD AND ESPECIALLY CMX
INTO THURSDAY. USED CONSENSUS GUIDANCE FOR CIGS/VIS AND MORE
CLIMATOLOGY FOR LAKE EFFECT SNOW LATE IN THE PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 317 PM EST WED DEC 4 2013
LOW PRESSURE OVER WISCONSIN WILL DEEPEN ACROSS CENTRAL AND EASTERN
LAKE SUPERIOR OVERNIGHT...AND EXIT NORTHEAST ACROSS JAMES BAY WHILE
FURTHER DEEPENING THURSDAY NIGHT. THE PERIOD OF STRONG WINDS WILL
CONTINUE THROUGH THURSDAY NIGHT...WITH OUR INITIAL E TO NE WINDS
/GALES TO 35KTS OVER W LAKE SUPERIOR/ BECOMING OUT OF THE S AND SW
FOR ALL BUT FAR W LAKE SUPERIOR OVERNIGHT...BEFORE W GALES OF 35 TO
40 KNOTS START UP THURSDAY MORNING THROUGH THURSDAY NIGHT.
A STRONG ARCTIC HIGH PRESSURE SYSTEM OVER WESTERN CANADA ON THURSDAY
WILL SLIDE ACROSS THE NORTHERN PLAINS ON SATURDAY...AND ACROSS THE
GREAT LAKES SUNDAY. THE HIGH WILL EXIT ACROSS THE NEW ENGLAND STATES
WHILE WEAKENING SLIGHTLY ON MONDAY. EXPECT LOW PRESSURE OVER THE
LOWER MISSISSIPPI VALLEY SUNDAY TO DEEPEN AND SURGE NORTHWARD ACROSS
LAKE HURON LATE SUNDAY NIGHT INTO MONDAY. W TO NW GALES TO 35KTS
WILL BE POSSIBLE AGAIN MONDAY THROUGH TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ THURSDAY
FOR MIZ002-004-005-009>011-084.
LAKE EFFECT SNOW ADVISORY FROM 4 AM TO 7 PM EST THURSDAY FOR
MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 4 AM EST THURSDAY FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING FROM 6 AM THURSDAY TO 4 AM EST FRIDAY FOR
LSZ265>267.
GALE WARNING UNTIL 4 AM EST FRIDAY FOR LSZ263-264.
GALE WARNING FROM 8 AM TO 7 PM EST THURSDAY FOR LSZ246>248-250-
251.
GALE WARNING FROM 5 AM EST /4 AM CST/ TO 7 PM EST /6 PM CST/
THURSDAY FOR LSZ241>245.
GALE WARNING UNTIL 10 PM EST /9 PM CST/ THURSDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KF
AVIATION...TITUS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 PM EST WED DEC 4 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 400 PM EST WED DEC 4 2013
20Z SFC CHART INDICATES ELONGATED SFC TROUGH FROM WCNTRL WI INTO
NORTHEAST IA WITH MSLP OF 998MB. WV AND RUC FCST SHOWS SHORTWAVE
PUSHING ACROSS SOUTHERN MINNESOTA. WAVE IS EXPECTED TO LIFT TOWARD
NORTHWEST WI WHILE DEEPENING OVERNIGHT. WARM AIR ADVECTION IN FULL
SWING AHEAD OF MAINLY 850MB LOW LIFTING INTO NW WISCONSIN. RUC13 AND
NAM12 HAVE DONE NICE JOB WITH THE WARM LAYER AT H9-H85 TODAY AND
BOTH SHOW H85 TEMPS OVER 2C REACHING NORTH OF ALL CWA BY 00Z.
SOUNDINGS OVER US CURRENTLY WOULD SUGGEST MAINLY FZRA BUT LINGERING
COLD POCKET NEAR SFC /TEMPS STILL IN MID-UPR 20S/ IS ALLOWING SLEET
TO HANG ON LONGER. CURRENTLY SNOW IS STILL FALLING OVER KEWEENAW
PENINSULA BUT IS EVEN STARTING TO MIX WITH FREEZING RAIN AND SLEET
OVER PORTIONS OF WESTERN UPR MICHIGAN. PLAN FOR EVENING IS THAT
MIXED FREEZING RAIN/SLEET/SNOW WILL CHANGE TO MAINLY FREEZING RAIN
AND SLEET WHILE MOSTLY FREEZING RAIN OR EVEN JUST RAIN OCCURS FOR
CNTRL CWA...ESPECIALLY CLOSER TO LK MICHIGAN SHORE. IF HEAVIER
PRECIP WAS EXPECTED OVR CNTRL THIS EVENING...ICING COULD BE BIGGER
ISSUE. RIGHT NOW...APPEARS THAT HEAVIER PRECIP IS GOING TO OCCUR IN
STRIPE FROM SOUTHERN MINNESOTA TOWARD WESTERN LK SUPERIOR IN AREAS
OF STRONGEST PVA/DIVERGENCE ALOFT JUST AHEAD OF TRACK OF SHORTWAVE.
GIVEN TREND TO MORE FZRA THOUGH...INCREASED ICE ACCUMS OVER INTERIOR
WEST AND CNTRL TO 0.10-0.20 INCHES THROUGH THE EVENING.
AS MID-LEVEL DRYING IN THE H7-H6 LAYER ARRIVES 03Z-06Z OVER THE
SOUTH AND AFTER 06Z IN THE NORTH...EXPECT WINTRY MIX OF PRECIP TO
TAPER OFF TO MORE OF A DRIZZLE/FREEZING DRIZZLE. ACTUALLY HEADLINES
SO FAR ARE WORKING OUT PRETTY WELL. DID HAVE TO GO WITH MORE SLEET
AND FREEZING RAIN AS WARM AIR WORKED IN QUICKER...BUT OVERALL IDEA
OF WINTRY MIX IS COVERED WITH GOING WINTER WEATHER ADVY. TIMING FOR
ENDING OF ADVY SEEMS GOOD AS WELL. ONLY POSSIBLE TROUBLE SPOTS WILL
IN THE INTERIOR CNTRL AND EAST THIS EVENING DUE TO ICING IF HEAVIER
PRECIP ENDS UP BLOSSOMING TO THE EAST OF PRIMARY SHORTWAVE. SOME
SHORT TERM HIGHER-RES MODELS INDICATE EXPANSION OF PRECIP OVER
SCNTRL THIS EVENING...BUT RADAR TRENDS UPSTREAM NOT REALLY SHOWING
THIS. IF SFC TEMPS STAY BLO FREEZING THAT AREA WILL NEED TO BE
WATCHED FOR POSSIBLE ADVY.
NOW ONTO LATE TONIGHT AND THURSDAY. MAIN ISSUE SEEMS TO BE LK EFFECT
AND BLOWING SNOW ON THE KEWEENAW. WEST WINDS MAY GUST OVER 40 MPH AT
TIMES LEADING TO THE BLSN/POOR VISIBILITY...PROBABLY 1/4-1/2SM AT
TIMES OVER PORTIONS OF THE KEWEENAW. LARGER SCALE FORCING BECOMES
NEGATIVE BUT THERE IS A LOT OF LINGERING MOISTURE BLO H8 WITH
COOLING AT INVERSION TOP TO -16C OR SO BY MIDDAY. GIVEN LK SUPERIOR
WATER TEMPS AROUND 3-4C THIS GIVES MORE THAN SUFFICIENT OVER-WATER
INSTABILITY FOR AT LEAST MODERATE LK EFFECT SNOW SHOWERS. WSW WINDS
OVER LAND WITH MORE OF A WESTERLY WIND OVER LK SUPERIOR INDICATES
STRONGER CONVERGENCE AREA SETS UP ACROSS KEWEENAW. SNOW AMOUNTS WILL
BE HELD DOWN SOME BY LOWER SLR/S AS THERE IS A LOT OF FRACTURING OF
SNOWFLAKES DUE TO THE STRONG WINDS. EXPECT ADVY LEVEL SNOWS OF 3-5"
OR 4-7" WITH A LOT OF WIND/BLSN. WILL ISSUE A SEPARATE LAKE EFFECT
SNOW ADVY FOR LATE TONIGHT THROUGH THURSDAY...GOING INTO PLACE RIGHT
WHEN THE CURRENT WINTER WEATHER ADVY FOR THE MESSY MIX OF SNOW/SLEET
AND FREEZING RAIN DIMINISHES.
AND FINALLY FOR LATE TONIGHT INTO THURSDAY...AWAY FM THE
KEWEENAW...MAIN ISSUE WILL BE COLD AIR PUSHING IN FM THE WEST.
ALREADY SEEING THIS ARCTIC AIR POURING ACROSS THE DAKOTAS THIS AFTN.
EXPECT SLOWLY FALLING TEMPERATURES THROUGH THE DAY AS THE COLD WORKS
EAST...WITH READINGS LIKELY INTO THE UPPER SINGLE DIGITS BY EVENING
OVER THE FAR WEST CWA. THIS COLDER AIR WILL ALSO FREEZE ANY
LINGERING SLUSH AND WATER IS ON THE ROADS AND SIDEWALKS...WHICH
COULD RESULT IN TOUGHER TRAVEL CONDITIONS IN SPOTS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 507 AM EST WED DEC 4 2013
MAIN FCST CONCERNS IN THE LONG TERM INCLUDE TEMPS/LES MAINLY IN THE
W-NW SN BELTS AND THE POTENTIAL FOR ANOTHER LARGER SCALE SN EVENT
EARLY NEXT WEEK. OVERALL TEMPS WL RUN WELL BLO NORMAL MOST OF THE
LONGER TERM WITH ARCTIC HI PRES DOMINATING. THE COLDEST AIRMASS OF
THE SEASON IS LIKELY TO INVADE THE UPR LKS IN THE WAKE OF THE LO
PRES SYSTEM THAT MIGHT BRING THE WDSPRD SN LATE SUN INTO MON.
THU...STRONG LLVL W FLOW IN THE WAKE OF LO PRES SHIFTING NEWD THRU
ONTARIO WL DRAW MUCH COLDER AIR INTO THE UPR LKS. IN FACT...THE
COLDEST GUIDANCE SHOWS H85 TEMPS APRCHG -20C OVER THE WRN CWA BY 00Z
FRI. THE ARRIVAL OF VIGOROUS DEEP LYR QVECTOR DVGC RESULTING FM THIS
INTENSE CAD AND DNVA/MID LVL DRYING WL SUPPRESS ANY LARGE SCALE
PCPN. BUT LES WL DVLP IN THE SN BELTS FAVORED BY THE LLVL W
FLOW...PRIMARILY OVER THE KEWEENAW. SOME MODEL FCST SDNGS SHOW A
PERIOD WHERE THE SHARPER OMEGA WITHIN THE MOIST LYR IS FAVORABLY
ALIGNED WITHIN THE DGZ TO CAUSE A RELATIVELY HI SN/WATER RATIO. SO
ADVYS FOR LES MAY BE NECESSARY FOR THE KEWEENAW. WITH WNW H925 WINDS
UP TO 35-40 KTS AND VIGOROUS CAD THAT WL CAUSE CONSIDERABLE LLVL
DESTABILIZATION...WINDS AT EXPOSED LOCATIONS ESPECIALLY OVER THE
KEWEENAW MAY ALSO APRCH ADVY CRITERIA. ALTHOUGH THESE STRONG WINDS
WL BREAK UP THE DENDRITIC SN FLAKES AND REDUCE THE OTRW FVRBL
SN/WATER RATIOS...THE RESULTING BLSN FM THE SMALLER FLAKES WL
EFFECTIVELY REDUCE VSBY. WITH THE ARCTIC AIR INVASION... TEMPS ARE
LIKELY TO FALL THRU THE DAY.
THU NGT INTO SAT...AS THE LO TO THE NE DRIFTS SLOWLY INTO QUEBEC AND
ARCTIC HI PRES SLIDES FM WRN CANADA INTO THE NRN PLAINS...THE STEADY
FLOW OF VERY COLD AIR IS PROGGED TO SLOWLY VEER MORE TO THE WNW AND
DIMINISH WITH TIME AS H85 TEMPS FALL SLOWLY TO -18C OVER THE E AND
-20C OR -21C OVER THE W BY SAT. THIS TYPICAL WINTER WX REGIME WL
FAVOR NEARLY CONTINUOUS LES IN THE FAVORED SN BELTS. A SHRTWV
TRACKING EWD THRU SRN ONTARIO/NRN LK SUP ON FRI NGT AND ACCOMPANYING
DEEPER MSTR MAY RESULT IN SOME ENHANCEMENT TO THE LES. ALTHOUGH THE
WINDS/BLSN WL BE DIMINISHING GRDLY...EXPECT LES/WINTER WX ADVYS TO
BE IN PLACE FOR THE FAVORED LES BELTS WITH FAVORABLE ALIGNMENT OF
THE LLVL OMEGA WITHIN THE DGZ. WENT HIER THAN MODEL CONSENSUS POPS
FOR LES IN THE FAVORED SN BELTS...USING CLIMATOLOGRY GRIDS TO
EVALUATE THE POPS. AS THE LLVL WINDS DIMINISH...LAND BREEZE CNVGC
MAY PLAY A MORE IMPORTANT ROLE IN ENHANCING THE LES BANDS IN SOME
PLACES...WITH AT LEAST LOCALLY HEAVIER SN FALL APRCHG WARNING
CRITERIA. SN/WATER RATIOS WL ALSO LIKELY BE FVRBL FOR LARGER FLAKES
AS THE FLAKE FRACTURING DIMINISHES. AWAY FM THE FAVORED SN
BELTS...THE WX DURING THIS TIME WL BE VERY COLD BUT DRY. SUB ZERO
MIN TEMPS WITH DAYTIME TEMPS STRUGGLING TO RISE ABV 10F WL THE RULE
OVER THE INTERIOR W HALF WITHIN THE LESS MODIFIED ARCTIC AIR.
SAT NGT/SUN...THE SLOW EWD PUSH OF THE ARCTIC HI CENTER FM THE NRN
PLAINS INTO THE GREAT LKS/SLOWLY BACKING WINDS TO WSW ON SUN WL
CAUSE THE LES TO DIMINISH. DEPENDING ON HOW QUICKLY WAD CLDS SPILL
INTO THE UPR LKS ON SUN TO THE E OF A DEEPENING TROF IN THE
PLAINS...TEMPS AT SOME PLACES OVER THE INTERIOR ON EARLY SUN MRNG
MAY FALL INTO THE TEENS BLO ZERO WITH LGT WINDS UNDER THE ARRIVING
SFC HI CENTER.
EXTENDED...NEXT LARGER SCALE PCPN EPISODE IS LIKELY TO ARRIVE ON SUN
NGT INTO EARLY MON. SOME OF THE LONGER TERM MODELS ARE SHOWING A
PHASING OF THE ARCTIC/POLAR BRANCHES WITH A DEEPER SFC LO TRACKING
THRU THE WCENTRAL GREAT LKS. IF THIS SCENARIO WERE TO VERIFY...A
WDSPRD ADVY SN WL BE PSBL OVER MUCH OF THE CWA. BUT SOME OF THE
GUIDANCE HINTS AT LESS PHASING/A WEAKER SFC LO THAT WOULD CAUSE JUST
A COUPLE OF INCHES. IN THE WAKE OF THIS LO MOVING INTO ONTARIO ON
MON...THE COLDEST AIRMASS OF THE SEASON WITH H85 TEMPS AS LO AS -25
TO -28C WL INVADE THE UPR LKS. NEXT TUE LOOKS PARTICULARLY COLD WITH
A SHARP PRES GRADIENT/NW FLOW THAT MIGHT CAUSE WIND CHILLS TO FALL
TO ADVY LVL. TENDED HIER THAN MODEL CONSENSUS FOR LES POPS IN THE
FAVORED SN BELTS FOR MON THRU TUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1234 PM EST WED DEC 4 2013
A LOW PRESSURE SYSTEM WILL KEEP PRECIP AT THE TAF SITES INTO
TONIGHT. WARM AIR MOVING INTO THE REGION WILL SWITCH SNOW THIS
MORNING TO RAIN AND FREEZING RAIN AT TIMES INTO EARLY TONIGHT...MOST
LIKELY AT SAW AND MORE LIKELY TO STAY A WINTRY MIX AT IWD AND CMX.
LOTS OF DIFFICULTY FORECASTING EXACT CHANGE OVER TIMES...SO PUT BEST
GUESS INTO TAFS. PRECIP WILL CHANGE BACK TO SNOW TONIGHT AS COLD AIR
COMES IN BEHIND A COLD FRONT...WHILE PRECIP TRANSITIONS FROM AREA
WIDE PRECIP TO LAKE EFFECT SNOW...FAVORING IWD AND ESPECIALLY CMX
INTO THURSDAY. USED CONSENSUS GUIDANCE FOR CIGS/VIS AND MORE
CLIMATOLOGY FOR LAKE EFFECT SNOW LATE IN THE PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 317 PM EST WED DEC 4 2013
LOW PRESSURE OVER WISCONSIN WILL DEEPEN ACROSS CENTRAL AND EASTERN
LAKE SUPERIOR OVERNIGHT...AND EXIT NORTHEAST ACROSS JAMES BAY WHILE
FURTHER DEEPENING THURSDAY NIGHT. THE PERIOD OF STRONG WINDS WILL
CONTINUE THROUGH THURSDAY NIGHT...WITH OUR INITIAL E TO NE WINDS
/GALES TO 35KTS OVER W LAKE SUPERIOR/ BECOMING OUT OF THE S AND SW
FOR ALL BUT FAR W LAKE SUPERIOR OVERNIGHT...BEFORE W GALES OF 35 TO
40 KNOTS START UP THURSDAY MORNING THROUGH THURSDAY NIGHT.
A STRONG ARCTIC HIGH PRESSURE SYSTEM OVER WESTERN CANADA ON THURSDAY
WILL SLIDE ACROSS THE NORTHERN PLAINS ON SATURDAY...AND ACROSS THE
GREAT LAKES SUNDAY. THE HIGH WILL EXIT ACROSS THE NEW ENGLAND STATES
WHILE WEAKENING SLIGHTLY ON MONDAY. EXPECT LOW PRESSURE OVER THE
LOWER MISSISSIPPI VALLEY SUNDAY TO DEEPEN AND SURGE NORTHWARD ACROSS
LAKE HURON LATE SUNDAY NIGHT INTO MONDAY. W TO NW GALES TO 35KTS
WILL BE POSSIBLE AGAIN MONDAY THROUGH TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ THURSDAY
FOR MIZ002-004-005-009>011-084.
LAKE EFFECT SNOW ADVISORY FROM 4 AM TO 7 PM EST THURSDAY FOR
MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 4 AM EST THURSDAY FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING FROM 6 AM THURSDAY TO 4 AM EST FRIDAY FOR
LSZ265>267.
GALE WARNING UNTIL 4 AM EST FRIDAY FOR LSZ263-264.
GALE WARNING FROM 8 AM TO 7 PM EST THURSDAY FOR LSZ247-248-250-
251.
GALE WARNING FROM 5 AM EST /4 AM CST/ TO 7 PM EST /6 PM CST/
THURSDAY FOR LSZ241>245.
GALE WARNING UNTIL 10 PM EST /9 PM CST/ THURSDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...TITUS
MARINE...KF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
302 PM CST WED DEC 4 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 257 PM CST WED DEC 4 2013
AN ARCTIC AIRMASS HAS SETTLED ACROSS THE NORTHERN AND CENTRAL
PLAINS...AND H85 TEMPS ARE ON THE ORDER OF 2 TO 3 STANDARD
DEVIATIONS BELOW NORMAL FOR THIS TIME OF YEAR. TEMPERATURES THIS
AFTERNOON HAVE STRUGGLED IN THE ARCTIC AIR AND READINGS AVERAGE IN
THE TEENS/20S ATTM. WINDS CONTINUE TO REMAIN STEADY/GUSTY IN A
TIGHT PRESSURE GRADIENT WITH A DEPARTING SFC LOW ACROSS EASTERN
IOWA AND A 1035MB SURFACE HIGH BUILDING SOUTHEAST FM MONTANA. THE
COMBINATION OF THE GUSTY WINDS AND COLD TEMPS HAVE RESULTED IN
WINDS CHILLS IN THE SINGLE DIGITS THIS AFTERNOON. SNOW FLURRIES
ACROSS OUR EASTERN ZONES CONTINUE WILL CONTINUE TO DIMINISH AS WE
HEAD THRU THE REMAINDER OF THE AFTN IN A SUBSIDENT/CLEARING AREA.
THIS EVENING...A 150KT H25 JET EMERGES FROM THE CENTRAL ROCKIES
AND CROSSES THRU NEBRASKA AND A MID LEVEL TROUGH TRANSLATES ACROSS
THE CENTRAL PLAINS. COLD AIR IS REINFORCED WITH THIS NEXT TROUGH
MOVING THRU THIS EVENING AND A BAND OF MID LEVEL FRONTOGENESIS IS
PROGGED ACROSS OUR SOUTHERN ZONES. IN FAVORABLE JET DYNAMICS AND
PRESENCE OF THE FRONTOGENESIS...A NARROW CORRIDOR OF BANDED
SNOWFALL IS EXPECTED TO DEVELOP DURING THE EVENING. MODELS ARE NOT
IN COMPLETE AGREEMENT ON WHERE THIS BAND WILL SET UP WITH THE GFS
THE FARTHEST NORTH WITH THE BAND...THE 12Z NAM WAS THE FARTHEST
SOUTH WITH THE BAND BUT HAS TRENDED NORTHWARD WITH THE 18Z RUN.
EARLIER RUNS OF THE RAP WERE MORE SIMILAR TO THE CURRENT 18Z
NAM...HOWEVER THE LATEST RUNS OF THE RAP HAVE TRENDED FARTHER
SOUTH INTO CENTRAL KANSAS WITH THE POSITION. THIS BEING
SAID...NORTH CENTRAL KANSAS IS STILL THE MOST FAVORABLE LOCATION
FOR SNOWFALL THIS EVENING. POPS HAVE BEEN INCREASED AND WHERE BAND
SETS UP...SOME HALF INCH SNOWFALL AMOUNTS OR SO ARE NOT OUT OF THE
QUESTION. FARTHER NORTH OF THE BAND...FLURRIES ARE POSSIBLE UNTIL
THE MID LEVEL TROUGH AXIS PASSES TO THE EAST BY AROUND MIDNIGHT OR
SHORTLY THEREAFTER.
OVERNIGHT TEMPERATURES WILL REMAIN FRIGID AND CLOUDS BEGIN TO SCOUR
BEFORE DAYBREAK. HAVE WENT WITH LOW TEMPS IN THE SINGLE DIGITS
ABOVE ZERO TONIGHT AND WHEN COMBINED WITH THE STEADY NORTHWESTERLY
WINDS...WIND CHILL READINGS WILL DROP TO ROUGHLY 8 TO 18 DEGREES
BELOW ZERO ACROSS OUR CWA. THE COLDEST READINGS WILL BE ACROSS OUR
NW ZONES...AND THE 18 BELOW VALUES REMAIN SHY OF WIND CHILL ADVISORY
CRITERIA SO WILL HOLD OFF ON HEADLINE AND CONTINUE TO MENTION COLD
WIND CHILLS IN THE HWO.
THE ARCTIC AIRMASS WILL REMAIN IN PLACE ON THURSDAY...WITH FRIGID
-18C AIR SETTLING IN AT H85. THE SFC RIDGE AXIS WILL CONTINUE TO
NOSE SOUTHEAST ONTO THE PLAINS AND DRY AND VERY COLD WEATHER IS
FORECAST. TEMPS WILL CONTINUE TO STRUGGLE IN THE COLD AIRMASS AND
WILL GIVE TEMPS ABOUT A 10 DEGREE RISE FROM MORNING LOWS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 257 PM CST WED DEC 4 2013
THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE CHANCE FOR SNOW SATURDAY NIGHT THROUGH SUNDAY NIGHT
AND COLD TEMPERATURES THROUGH THE PERIOD.
A COLD SURFACE HIGH PRESSURE SYSTEM WILL PUSH INTO THE AREA FOR
THURSDAY NIGHT THROUGH FRIDAY NIGHT. THE CENTER OF THE HIGH WILL
REMAIN NORTH AND EAST OF THE AREA AND WINDS WILL CONTINUE TO BE
AROUND 5 TO 15 MPH. WITH THE TEMPERATURES ALREADY IN THE SINGLE
DIGITS ABOVE AND BELOW ZERO...THE WIND CHILL VALUES WILL DROP INTO
THE -10 TO -20 DEGREE RANGE ACROSS THE AREA.
ON SATURDAY THE SURFACE HIGH MOVES OFF TO THE EAST AND WINDS TURN TO
THE SOUTH. AN UPPER LEVEL WAVE APPROACHES THE AREA FROM THE
SOUTHWEST. THERE IS INCREASING MOISTURE ACROSS THE AREA AND CLOUDS
WILL INCREASE.
SATURDAY NIGHT THROUGH SUNDAY NIGHT THE UPPER LEVEL WAVE WILL MOVE
THROUGH THE REGION. STARTING SATURDAY NIGHT THERE IS WARM ADVECTION
OF MOIST AIR OVER THE COLD SURFACE. EXPECT SNOW TO START ACROSS THE
AREA DURING THE EVENING AND CONTINUE INTO SUNDAY. THE BEST CHANCES
WILL LIKELY BE LATE SATURDAY NIGHT INTO SUNDAY MORNING. MODELS HAVE
SOME VARIABLE QPF AMOUNTS BUT IT LOOKS LIKE THERE WILL BE
ACCUMULATING SNOWFALL. WITH THE COLD TEMPERATURES THERE WILL MOST
LIKELY BE LIGHT FLUFFY SNOWFALL. AN ADVANTAGE IS THAT CURRENTLY
THERE IS NOT SIGNIFICANT WIND WITH THE SYSTEM. BY SUNDAY EVENING THE
MAIN UPPER WAVE IS THROUGH THE AREA AND THE SNOWFALL WILL GRADUALLY
COME TO AN END SUNDAY NIGHT.
A COLD SURFACE HIGH PRESSURE SYSTEM MOVES INTO THE SOUTHERN PLAINS
ON MONDAY AND COLD TEMPERATURES WILL CONTINUE ACROSS THE AREA MONDAY
INTO TUESDAY. TUESDAY NIGHT ANOTHER WEAK UPPER LEVEL WAVE APPROACHES
THE AREA. THE MAIN WAVE IS FURTHER TO THE NORTH. MOST OF THE
MOISTURE IS FURTHER NORTH AND NOT MUCH CHANGE FROM MONDAY AND
TUESDAY. THE ONLY CHANGE WILL BE A POTENTIAL FOR SOME SLIGHTLY
WARMER TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1120 AM CST WED DEC 4 2013
KGRI WILL REMAIN UNDER THE INFLUENCE OF AN ARCTIC AIRMASS THROUGH
THE TAF PERIOD. HAVE MAINTAINED MVFR CIGS INTO THE OVERNIGHT
PERIOD...THEN SCATTERED CLOUDS BY THURSDAY MORNING BEHIND PASSAGE
OF MID LEVEL TROUGH AXIS. WINDS WILL REMAIN STEADY/GUSTY FM THE
NORTHWEST...WITH WIND SPEEDS DIMINISHING TO SOME DEGREE THURSDAY
MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1154 AM CST WED DEC 4 2013
.AVIATION...18Z TAFS FOR KOMA...KLNK AND KOFK.
CURRENT OBS INDICATE AREAS OF -SN ALONG AND WEST OF AN AXIS FROM
ABOUT KFSD TO KHDE. -SN ACTIVITY WAS TRACKING NE IN ASSOCIATION
WITH AN UPPER DISTURBANCE MOVING TWD THE DAKOTAS. KOFK WAS
REPORTING -SN...BUT RADAR TRENDS SUGGEST ACTIVITY IS N0T MAKING
MUCH OF A PUSH EAST. SUSPECT -SN WILL CONTINUE THE NEXT COUPLE
HOURS AT KOFK THUS WILL MAINTAIN TEMPO GROUP TILL 21Z.
OTHERWISE...MVFR CIGS EXTENDED FROM ERN NEB TO OVER MOST OF KS.
HOWEVER EXPECT VFR CIGS FL050 AGL CURRENTLY OVER CNTRL NEB WILL
GRADUALLY MOVE EAST...ALLOWING FOR IMPROVING CONDITIONS AT ALL
TERMINALS LATE THIS AFTN/EARLY EVENING TIME FRAME. SEEMS LIKELY AT
THIS POINT THAT VFR CIGS WILL PERSIST THEN THRU THE REST OF THE
FCST PD AT ALL SITES.
DEE
&&
PREV DISCUSSION... /ISSUED 305 AM CST WED DEC 4 2013/
DISCUSSION...
LOW PRESSURE WAS LOCATED OVER NORTH CENTRAL OKLAHOMA AT 08Z
WITH A STATIONARY FRONT STRETCHING ACROSS EASTERN KANSAS INTO
CENTRAL IOWA. RADAR SHOWS PRIMARY BAND OF SNOW EXTENDS FROM NORTH
CENTRAL NEBRASKA INTO SOUTHEAST SOUTH DAKOTA AND SOUTHWEST
MINNESOTA...WHILE WIDESPREAD FOG AND DRIZZLE WAS LOCATED ALONG
THE STATIONARY FRONT. SOME LIGHT SNOW STILL LIKELY FOR NORTHEAST
BORDER AREA THIS MORNING AS SYSTEM LIFTS NORTHEAST WITH UP TO
AN INCH POSSIBLE BEFORE ENDING THIS AFTERNOON.
FREEZING DRIZZLE HAS STARTED TO BECOME MORE WIDESPREAD IN EASTERN
NEBRASKA AS THE COLDER AIR PUSHES INTO THE AREA. RAP FORECAST
SOUNDINGS SUGGEST THE POTENTIAL FOR FREEZING DRIZZLE THROUGH MOST
OF THE MORNING FOR SOUTHEAST NEBRASKA AND SOUTHWEST IOWA BEFORE
SOMEWHAT DRIER AIR WORKS INTO THE LOW LEVELS. WILL PROBABLY WAIT
UNTIL JUST BEFORE ISSUANCE TO BETTER ASSES EXTENT OF THE PRECIP
BUT ADVISORY SEEMS LIKELY AT SOME POINT.
STRONG COLD ADVECTION FINALLY ARRIVES DURING THE AFTERNOON AS AREA
COMES ON THE BACK SIDE OF THE DEPARTING SYSTEM. FOR THE REMAINDER
OF THE SHORT TERM TEMPERATURES BECOME THE PRIMARY FORECAST CONCERN
WITH VERY COLD WIND CHILLS DEVELOPING ESPECIALLY IN THE NORTH HALF
OF THE AREA.
LITTLE CHANGE IN THE EXTENDED PERIOD WITH STILL SOME CHANCE OF
SNOW LATE SATURDAY INTO SUNDAY WITH COLD TEMPERATURES CONTINUING.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
136 PM EST WED DEC 4 2013
.SYNOPSIS...
A WEAK WARM FRONT WILL LIFT NORTH THROUGH THE REGION TODAY.
OFFSHORE HIGH PRESSURE THEN INFLUENCES THE AREA WEATHER THROUGH
THE END OF THE WEEK. A COLD FRONT WILL APPROACH LATE IN THE WEEK
AND WILL CROSS THE REGION ON SATURDAY. A STRONGER COLD FRONT WILL
CROSS THE REGION TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM WED...EXTENDED HIGHER POPS INTO EARLY AFTN WITH PATCHY
RAIN EXPECTED TO AFFECT AREA SEVERAL MORE HOURS. ALSO KEPT CLOUDS IN
LONGER THIS AFTN AND LOWERED MAX TEMPS SEVERAL DEGS.
/PREVIOUS DISCUSSION/
AS OF 600 AM WEDNESDAY...A WEAK DISTURBANCE IN THE LOW AMPLITUDE
FLOW ALOFT WILL IMPINGE ON MOIST LOW LEVEL AIRMASS WHERE WARM
ADVECTION WAS PRODUCING SUFFICIENT ISENTROPIC UPGLIDE TO PRODUCE
WIDESPREAD MOSTLY LIGHT PRECIPITATION THIS MORNING. AT THE SURFACE
THE PRECIPITATION WAS ASSOCIATED WITH A WEAK NORTHWARD MOVING WARM
FRONT WHICH IS FORECAST TO MOVE THROUGH THE AREA LATER TODAY.
REGIONAL RADARS INDICATE AN EXTENSIVE AREA OF RAIN THAT EXTENDS
ACROSS THE CAROLINAS TO SOUTHEAST VIRGINIA. WITH PW VALUES FORECAST
TO RISE TO AROUND 1.3", SOME OF THE PRECIPITATION COULD PRODUCE
BRIEF LOCAL DOWNPOURS AT TIMES. EXPECTING STORM TOTAL QPF OF 0.25 TO
0.50" IN MOST LOCATIONS WITH SOME LOCALLY HEAVIER AMOUNTS. SIDED
WITH THE SLIGHTLY FASTER ECMWF/GFS SOLUTIONS WHICH INDICATE THAT THE
RAIN WILL BE TAPERING OFF FROM WEST TO EAST BEGINNING EARLY THIS
AFTERNOON. CLOUDS WILL BE SLOWER TO DISSIPATE AND EXPECT SKIES TO
REMAIN CLOUDY/MOSTLY CLOUDY THROUGHOUT THE DAY. DESPITE THE
CLOUDS/PRECIPITATION, TEMPERATURES ARE FORECAST TO BE ABOVE NORMAL
DUE TO SOUTHERLY FLOW WITH READINGS IN THE MIDDLE TO UPPER 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS OF 310 AM WEDNESDAY...COULD BE A LINGERING SHOWER OR TWO ALONG
THE OUTER BANKS EARLY, OTHERWISE EXPECT CLOUDS TO DIMINISH DURING
THE EVENING. THE LOW LEVELS WILL REMAIN RATHER MOIST THOUGH, AND
THIS WOULD TEND TO SUPPORT THE DEVELOPMENT OF LOW STRATUS CLOUDS.
IN ADDITION IF WINDS CAN DECOUPLE, WHICH IS UNCERTAIN AT THIS
TIME, THEN PATCHY DENSE FOG COULD ALSO DEVELOP. EXPECT MILD LOWS
IN THE LOWER TO MIDDLE 50S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 310 AM WED...A LONGWAVE NRN STREAM UPPER TROUGH WILL BE IN
PLACE ACROSS THE WRN CONUS THROUGH THE LATTER HALF OF THE WEEK
WHILE SW/NE ORIENTED UPPER RIDGE AMPLIFIES ACROSS THE SRN GOM AND
OFF THE SOUTHEAST COAST BRINGING SW FLOW ALOFT ACROSS THE ERN
CONUS. ABUNDANT PACIFIC MOISTURE WILL BE TRANSPORTED ACROSS THE
SOUTHERN PLAINS IN THE MID-ATLANTIC WHILE A SLOW MOVING COLD FRONT
PUSHES ACROSS THE MID-WEST AND MID-ATLANTIC STATES. DEEPEST
MOISTURE AND BEST UPPER LEVEL DYNAMICS WILL REMAIN NORTH AND WEST
OF THE REGION AND EXPECT MAINLY DRY CONDITIONS BUT WILL SEE
INCREASED CLOUD COVER ACROSS ERN NC. A WARMING TREND CONTINUES
WITH SFC HIGH OFFSHORE BRINGING INCREASING SWLY FLOW THROUGH THE
END OF THE WEEK. MODELS TRENDING A LITTLE WARMER WITH TEMPS THU
AND FRI AND EXPECT HIGH IN THE MID 70S THU AND POSSIBLY A FEW
UPPER 70S ON FRI...ABOUT 10-15 DEGREES ABOVE NORMAL.
UPPER LEVEL ENERGY EJECTING NEWD OUT OF THE UPPER TROUGH WILL AID IN
PUSHING THE COLD FRONT THROUGH THE REGION EARLY SATURDAY. BEST
PRECIP CHANCES OCCUR AFTER FROPA WITH SWLY UPPER LEVEL FLOW AND
MOISTURE OVERRUNNING THE SHALLOW COLD AIR WITH HIGH PRES BUILDING IN
FROM THE N WHICH CONTINUES INTO SUNDAY. MODELS STILL CONVERGING ON
THE TIMING OF THE FRONT WHICH WILL HAVE A BIG IMPACT TEMPS FRI NIGHT
AND SAT. PREFERRED MODEL IS THE ECMWF WHICH PUSHES THE FRONT THROUGH
AFTER 12Z SAT WHICH WILL KEEP THE REGION IN THE WARM SECTOR FRIDAY
NIGHT...WITH FALLING TEMPS AFTER FROPA SATURDAY.
THE FRONT WILL LIFT BACK NORTH AS A WARM FRONT SUN NIGHT AS THE
LONGWAVE WEST COAST TROUGH FINALLY PUSHES EASTWARD...LIFTING A
DEEPENING AREA OF LOW PRES AREA INTO THE GREAT LAKES. THE REGION
WILL BE BACK IN THE WARM SECTOR MONDAY WITH TEMPS WARMING BACK ABOVE
NORMAL WITH POPS LOWERING AS ISENTROPIC LIFT LIFT SHIFTS NORTH.
MODELS ALSO CONTINUE TO SHOW MINIMAL INSTABILITY DEVELOPING ACROSS
THE REGION MONDAY WITH SWLY FLOW...THOUGH WILL NOT INCLUDE MENTION
OF THUNDER AT THIS TIME. THE TRAILING COLD FRONT IS CURRENTLY
PROGGED TO PUSH THROUGH THE REGION TUESDAY BRINGING A GOOD CHANCE
OF RAIN ONCE AGAIN. AN ARCTIC AIRMASS BUILDS IN BEHIND THIS FRONT
AND EXPECT BELOW NORMAL TEMPS FOR THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH 18Z WEDNESDAY/...
AS OF 100 PM WEDNESDAY...MOST OF THE STEADY RAIN HAS MOVED EAST OF ALL
TAF SITES. SATELLITE IMAGES CONTINUE TO SHOW AN IMPROVING TRENDS
OF CLOUDS HEIGHTS BECOMING TO MVFR. THERE IS MODERATE CONFIDENCE OF
CEILING HEIGHTS REACHING TO VFR. IF CONDITIONS BECOME VFR...IT CAN
OCCUR LATE AFTERNOON INTO THE EVENING AND SHOULD BE BRIEF AS
THERE IS A LARGE AMOUNT OF LOW LEVEL MOISTURE.
WITH SATURATED LOW LEVELS AND WINDS EXPECTED TO DECOUPLE TONIGHT..THIS
CAN LEAD TO LOW LEVEL STRATUS AND FOG DEVELOPMENT LATE NIGHT INTO
THURSDAY MORNING. GUIDANCE MODELS HAVE A GOOD AGREEMENT WITH
CONDITIONS BECOMING IFR/LIFR. AT THIS TIME...KEPT CONDITIONS TO
IFR FOR ALL TAF SITES. CONDITIONS ARE EXPECTED TO IMPROVE SLOWLY
TOMORROW LATE MORNING TO MVFR.
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 AM WED...PRED VFR CONDITIONS EXPECTED THU THROUGH
FRI...THOUGH PATCHY FOG/STRATUS WILL BE POSSIBLE EACH MORNING WITH
MOIST BL. A COLD FRONT WILL APPROACH THE AREA FROM THE NW FRI
NIGHT...MOVING THROUGH THE TERMINALS SAT MORNING. PROLONGED PERIOD
OF SUB-VFR CONDITIONS EXPECTED TO DEVELOP AFTER FRONTAL PASSAGE
SAT AND CONTINUE THROUGH MUCH OF SUNDAY WITH WIDESPREAD RAIN
EXPECTED. N/NE WIND GUSTS 15-20KT WILL DEVELOP BEHIND THE FRONT
SATURDAY AFTERNOON AS WELL. THE FRONT WILL LIFT BACK THROUGH THE
AREA SUN NIGHT WITH PRECIP CHANCES DIMINISHING AND LOWER CIGS
LIFTING N OF THE REGION BUT AREA OF FOGS WILL BE POSSIBLE.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1030 AM WED...ADJUSTED WINDS BASED ON LATEST OBS AND MESO
MODEL FCSTS. WARM FRONT STILL OVER SRN SECTIONS WITH SRLY WINDS 15
KTS OBSERVED AT 30 SE NEW RIVER INLET BUOY BUT LIGHT SE WINDS REST
OF AREA. UPDATED WITH BLEND OF RUC13 AND NAM12 FOR SLIGHTLY SLOWER
PROGRESSION OF WINDS BECOME SRLY THIS AFTN. NO CHANGES WITH SEAS.
/PREVIOUS DISCUSSION/
AS OF 600 AM WEDNESDAY...SOUTHERLY FLOW 15 KT OR LESS IS EXPECTED
ACROSS THE WATERS THROUGH TONIGHT AS A WEAK WARM FRONT MOVES
THROUGH THE REGION. SEAS WILL REMAIN 2 TO 4 FT THROUGH THE PERIOD.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 AM WED...SW FLOW GENERALLY 15KT OR LESS EXPECTED THU
WITH SEAS 2-4FT. SCA CONDITIONS EXPECTED TO DEVELOP EARLY FRI
MORNING AND CONTINUE THROUGH THE WEEKEND. PRESSURE GRADIENTS WILL
TIGHTEN LATE IN THE WEEK AS A FRONT APPROACHES FROM THE NW
ALLOWING SW WINDS TO INCREASE TO 15-25KT AND SEAS BUILD TO
4-7FT...HIGHEST SOUTH OF OREGON INLET. THERE WILL BE THE POTENTIAL
FOR SEA FOG TO DEVELOP ACROSS THE WATERS THU AND FRI GIVEN
EXPECTED AIR/WATER TEMPS AND MOIST SW FLOW. THE COLD FRONT WILL
MOVE THROUGH THE WATERS SAT...AND EXPECT GOOD NORTHERLY SURGE
15-25KT BEHIND THE FRONT...WORKING ITS WAY FROM NORTH TO SOUTH
THROUGH THE DAY...WITH SEAS AROUND 4-7FT. A WAVE WILL DEVELOP
ALONG THE FRONT TO THE SOUTH SUNDAY...THEN SLOWLY LIFT BACK NORTH
ACROSS THE WATERS LATE SUN AND SUN NIGHT WITH VEERING WINDS.
&&
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JME
NEAR TERM...JME
SHORT TERM...JME
LONG TERM...SK/CQD
AVIATION...CQD/BM
MARINE...JME/CQD
CLIMATE...
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1241 PM CST WED DEC 4 2013
.UPDATE...
ISSUED AT 1241 PM CST WED DEC 4 2013
SEE LSR REPORTS FOR LATEST SNOWFALL TOTALS. THESE OBSERVATIONS ARE
MATCHING THE PREVIOUS UPDATE AND THE FORECAST APPEARS ON TRACK.
WIND SPEEDS ARE ALSO BEHAVING...AND GUIDANCE INDICATES SPEEDS
SHOULD NOT GET TOO MUCH HIGHER. SO...THE PREVIOUS UPDATE INDICATED
STORM TOTAL SNOWFALL OF 4 TO 8 ACROSS SOUTHEAST NORTH DAKOTA INTO
THE SOUTHERN VALLEY...WITH 6 TO 12 INCHES ACROSS THE REMAINDER OF
EASTERN NORTH DAKOTA INTO NORTHWESTERN MINNESOTA. REMEMBER...THESE
ARE TOTALS THAT INCLUDE TUESDAY INTO THURSDAY MORNING. ADDITIONAL
SNOWFALL (AFTER 18Z) SHOULD RANGE FROM 1 TO 3 INCHES WESTERN FA INTO
THE SOUTHERN VALLEY...3 TO 6 INCHES NORTHERN VALLEY TO PARK RAPIDS
AREA...AND 6 TO 9 INCHES NORTHWESTERN MN.
UPDATE ISSUED AT 1032 AM CST WED DEC 4 2013
12Z NAM HAS COME IN WITH HIGHER QPF TOTALS FROM 12Z WED TO 12Z
THUR...AND THE 15Z RAP MOSTLY AGREES. THESE MODELS APPEAR TO BE
PICKING UP ON MESO-SCALE FORCING THAT THE GFS/ECMWF/SREF/GEM ARE
NOT INCLUDING. CURRENT RADAR IMAGERY WOULD APPEAR TO INDICATE AND
AREA OF STRONGER FORCING FROM SE NORTH DAKOTA INTO NORTHWEST
MINNESOTA...WHICH THE NAM/RAP SHOW IN THEIR QPF FIELDS. SNOW
RATIOS ARE EXPECTED TO BE 15:1 TO 20:1...POSSIBLY HIGHER. USING
THE 12Z NAM QPF AND EXPECTED SNOW RATIOS...INDICATE 12Z WED-12Z
THU SNOW TOTALS OF 10-13 INCHES ACROSS NW MN...7-10 INCHES WC MN
INTO THE CENTRAL AND NORTHERN VALLEY...AND 4-7 INCHES SOUTHERN
VALLEY AND WEST OF THE VALLEY. AS WINDS INCREASE...THIS SHOULD AT
LEAST BREAK APART THE SNOWFLAKES AND DECREASE RATIOS A BIT...SO
WILL INCREASE SNOW TOTALS...BUT SOMEWHERE IN BETWEEN WHAT WE HAD
AND WHAT THE NAM INDICATES.
WILL ALSO NEED TO MONITOR WIND SPEEDS AND BLOWING SNOW POTENTIAL.
DID INCREASE WINDS A BIT BASED ON LATEST OBSERVATIONS COMPARED TO
THE GUIDANCE. AS TEMPERATURES GET COLDER THE SNOW WILL BE EASIER
TO BLOW AROUND...SO COULD BE CLOSE TO BLIZZARD CONDITIONS IN THE
MORE PRONE AREAS. HOWEVER...WIND SPEEDS NOT EXPECTED TO REACH
BLIZZARD CRITERIA (35 MPH)...SO THE WINTER STORM WARNING IS A VERY
GOOD PRODUCT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 359 AM CST WED DEC 4 2013
WATER VAPOR LOOP INDICATED UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WAS DIGGING AS JET MOVES DOWN WEST SIDE OF TROUGH. ALSO
UPPER LEVEL LOW NOTED OVER NORTHERN NV AND NORTHWEST SASK AND A
SHORT WAVE OVER SOUTHEAST MT. MT SHORT WAVE TO MOVE ACROSS THE
FORECAST AREA THIS AFTERNOON AND TONIGHT. PRECIPITABLE WATER WAS
UNDER HALF AN INCH AND IS FORECAST TO DECREASE TODAY AND TONIGHT.
THE MT SHORT WAVE WAS ESSENTIALLY AN OPEN WAVE AND CLOSES OFF AFTER
MOVING EAST OF THE AREA. INVERTED SURFACE TROUGH EXTENDS FROM
NORTHWEST MN INTO IA. INVERTED TROUGH TO SHIFT EAST TODAY. RADAR
SHOWED LIGHT SNOW ACROSS MUCH OF ND INTO ADJACENT PARTS OF MN AND
WAS MOVING NORTHEAST ABOUT 25 KNOTS.
INCREASED TEMPS COUPLE DEGREES FOR TODAY THROUGH FRI WITH CLOUD
COVER EXPECTED TO STAY AROUND. NO CHANGE TO THE WARNING. WILL KEEP
WARNING AS IS.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 AM CST WED DEC 4 2013
FOR SAT THROUGH TUE...IT LOOKS LIKE A VERY COLD PERIOD WITH HIGHS
NEAR OR BELOW ZERO...AND BITTERLY COLD OVERNIGHT LOWS. THERE WILL BE
A CHANCE FOR SOME LIGHT SNOW MAINLY SUNDAY INTO EARLY MONDAY...AHEAD
OF ANOTHER RE-ENFORCING ARCTIC FRONT AND COLDER AIR. NO MAJOR PRECIP
EVENTS EXPECTED THOUGH AS WE REMAIN DEEPLY ENTRENCHED IN ARCTIC AIR
THROUGH THE PERIOD...WITH DANGEROUS WIND CHILLS LIKELY AN ISSUE
ANYTIME THE WIND BLOWS SINCE IT WILL BE SO COLD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1241 PM CST WED DEC 4 2013
GENERAL TREND WILL BE LIGHT TO MODERATE SNOW WITHIN AND EAST OF
THE VALLEY THROUGH MID AFTN. THIS WILL RESULT IN VSBY FLUCTUATIONS
FROM ABOUT 1/2SM TO 2SM...DEPENDING ON INTENSITY. WILL SEE THE
VALLEY IMPROVE FIRST FOLLOWED BY TVF/BJI IN THE LATE AFTN. CIGS
WILL PREDOMINANTLY REMAIN IFR WITH BREAKS INTO THE MVFR RANGE. BY
THE TIME CIGS IMPROVE...WINDS WILL KICK AROUND TO THE NW AND BLSN
COULD BE A PROBLEM OVERNIGHT. NOT CONFIDENT ENOUGH ON TIMING ANY
GIVEN SITE GOING BELOW 1SM...SO WILL HOLD OFF ON BLSN RELATED
VSBYS BEYOND THE FIRST SIX HOURS. CIGS WILL GRADUALLY CLIMB INTO
THE MVFR RANGE BY MORNING HOWEVER THE NW WINDS AND BLSN WILL
CONTINUE THROUGH 18Z THU.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WARNING UNTIL 6 AM CST THURSDAY FOR NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...WINTER STORM WARNING UNTIL 6 AM CST THURSDAY FOR MNZ001>009-
013>017-022>024-027>032-040.
&&
$$
UPDATE...TG
SHORT TERM...HOPPES
LONG TERM...DK
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1032 AM CST WED DEC 4 2013
.UPDATE...
ISSUED AT 1032 AM CST WED DEC 4 2013
12Z NAM HAS COME IN WITH HIGHER QPF TOTALS FROM 12Z WED TO 12Z
THUR...AND THE 15Z RAP MOSTLY AGREES. THESE MODELS APPEAR TO BE
PICKING UP ON MESO-SCALE FORCING THAT THE GFS/ECMWF/SREF/GEM ARE
NOT INCLUDING. CURRENT RADAR IMAGERY WOULD APPEAR TO INDICATE AND
AREA OF STRONGER FORCING FROM SE NORTH DAKOTA INTO NORTHWEST
MINNESOTA...WHICH THE NAM/RAP SHOW IN THEIR QPF FIELDS. SNOW
RATIOS ARE EXPECTED TO BE 15:1 TO 20:1...POSSIBLY HIGHER. USING
THE 12Z NAM QPF AND EXPECTED SNOW RATIOS...INDICATE 12Z WED-12Z
THU SNOW TOTALS OF 10-13 INCHES ACROSS NW MN...7-10 INCHES WC MN
INTO THE CENTRAL AND NORTHERN VALLEY...AND 4-7 INCHES SOUTHERN
VALLEY AND WEST OF THE VALLEY. AS WINDS INCREASE...THIS SHOULD AT
LEAST BREAK APART THE SNOWFLAKES AND DECREASE RATIOS A BIT...SO
WILL INCREASE SNOW TOTALS...BUT SOMEWHERE IN BETWEEN WHAT WE HAD
AND WHAT THE NAM INDICATES.
WILL ALSO NEED TO MONITOR WIND SPEEDS AND BLOWING SNOW POTENTIAL.
DID INCREASE WINDS A BIT BASED ON LATEST OBSERVATIONS COMPARED TO
THE GUIDANCE. AS TEMPERATURES GET COLDER THE SNOW WILL BE EASIER
TO BLOW AROUND...SO COULD BE CLOSE TO BLIZZARD CONDITIONS IN THE
MORE PRONE AREAS. HOWEVER...WIND SPEEDS NOT EXPECTED TO REACH
BLIZZARD CRITERIA (35 MPH)...SO THE WINTER STORM WARNING IS A VERY
GOOD PRODUCT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 359 AM CST WED DEC 4 2013
WATER VAPOR LOOP INDICATED UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WAS DIGGING AS JET MOVES DOWN WEST SIDE OF TROUGH. ALSO
UPPER LEVEL LOW NOTED OVER NORTHERN NV AND NORTHWEST SASK AND A
SHORT WAVE OVER SOUTHEAST MT. MT SHORT WAVE TO MOVE ACROSS THE
FORECAST AREA THIS AFTERNOON AND TONIGHT. PRECIPITABLE WATER WAS
UNDER HALF AN INCH AND IS FORECAST TO DECREASE TODAY AND TONIGHT.
THE MT SHORT WAVE WAS ESSENTIALLY AN OPEN WAVE AND CLOSES OFF AFTER
MOVING EAST OF THE AREA. INVERTED SURFACE TROUGH EXTENDS FROM
NORTHWEST MN INTO IA. INVERTED TROUGH TO SHIFT EAST TODAY. RADAR
SHOWED LIGHT SNOW ACROSS MUCH OF ND INTO ADJACENT PARTS OF MN AND
WAS MOVING NORTHEAST ABOUT 25 KNOTS.
INCREASED TEMPS COUPLE DEGREES FOR TODAY THROUGH FRI WITH CLOUD
COVER EXPECTED TO STAY AROUND. NO CHANGE TO THE WARNING. WILL KEEP
WARNING AS IS.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 AM CST WED DEC 4 2013
FOR SAT THROUGH TUE...IT LOOKS LIKE A VERY COLD PERIOD WITH HIGHS
NEAR OR BELOW ZERO...AND BITTERLY COLD OVERNIGHT LOWS. THERE WILL BE
A CHANCE FOR SOME LIGHT SNOW MAINLY SUNDAY INTO EARLY MONDAY...AHEAD
OF ANOTHER RE-ENFORCING ARCTIC FRONT AND COLDER AIR. NO MAJOR PRECIP
EVENTS EXPECTED THOUGH AS WE REMAIN DEEPLY ENTRENCHED IN ARCTIC AIR
THROUGH THE PERIOD...WITH DANGEROUS WIND CHILLS LIKELY AN ISSUE
ANYTIME THE WIND BLOWS SINCE IT WILL BE SO COLD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 702 AM CST WED DEC 4 2013
IFR CONDITIONS WERE ACROSS MUCH OF EASTERN ND WITH LOW VISIBILITIES
DUE TO SNOW. CIGS RISE TO 7 THOUSAND FT OVER THE FAR NORTHEAST
ZONES. EXPECT LOW CIGS TO SHIFT NORTHEAST THIS MORNING AS SNOW MOVES
NORTHEAST. WINDS WERE HIGHEST OVER THE WESTERN ZONES AND SHOULD
INCREASE THROUGH THE DAY. WINDS WILL REMAIN BRISK OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WARNING UNTIL 6 AM CST THURSDAY FOR NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...WINTER STORM WARNING UNTIL 6 AM CST THURSDAY FOR MNZ001>009-
013>017-022>024-027>032-040.
&&
$$
UPDATE...TG
SHORT TERM...HOPPES
LONG TERM...DK
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1201 PM CST WED DEC 4 2013
.AVIATION...
COMPLEX AVIATION FORECAST CONTINUES AS PERIPHERY OF ARCTIC AIRMASS
HAS SHIFTED SOUTH OF THE TERMINALS. LOW CLOUDS/STRATUS ARE
LAGGING...BUT HAVE SETTLED IN AT KGUY AND EDGED VERY NEAR KDHT.
TIMING FLIGHT CATEGORIES WITH THE INVADING STRATUS WILL BE DIFFICULT
DURING THE NEXT 6-12 HOURS. PROBABILITIES FOR RESTRICTIONS DUE TO
PRECIPITATION WILL INCREASE DURING THE 04/06-12Z TIMEFRAME.
&&
.PREV DISCUSSION... /ISSUED 1146 AM CST WED DEC 4 2013/
UPDATE...
UPDATE TO REWORK THE WINTER WEATHER ADVISORY. WILL NOW START THE
ADVISORY AT MIDNIGHT TONIGHT AND CONTINUE THROUGH 9 AM FRIDAY. THOUGH
WE ARE NOT EXPECTED SNOW TO LAST THROUGH THIS ENTIRE TIME...WE ALSO
WANTED TO EMPHASIZE THE DANGEROUS WIND CHILL VALUES.
JOHNSON
PREV DISCUSSION... /ISSUED 534 AM CST WED DEC 4 2013/
DISCUSSION...
THE ANTICIPATED COLD FRONT IS CURRENTLY WORKING SOUTH THROUGH THE
FORECAST AREA...WITH AN EXPECTED SURGE OF ARCTIC AIR LATER TODAY
PLUNGING THE PANHANDLES INTO SUBFREEZING TEMPERATURES THROUGH AT
LEAST THE WEEKEND. A PERIOD OF SNOWFALL WILL BE POSSIBLE FROM LATE
TONIGHT THROUGH EARLY FRIDAY MORNING. FURTHER CHANCES FOR LIGHT SNOW
MAY RETURN LATE IN THE WEEKEND.
SHORT TERM...TODAY THROUGH FRIDAY MORNING...
EVEN AT THIS LATE HOUR...THERE CONTINUES TO BE MODEL DISAGREEMENT
OVER THE TIMING AND POSITION OF THE COLD FRONT TODAY. AT LEAST AN
INITIAL SURGE HAS PUSHED THE FRONT TO THE SOUTH OF OUR CWA THIS
MORNING. THE LATEST RAP CONTINUES TO INDICATE A SLIGHT RETREAT OF THE
FRONT THIS AFTERNOON...ALLOWING FOR THE FAR SOUTHWEST TX PANHANDLE TO
WARM INTO THE UPPER 50S OR LOWER 60S. A FINAL SURGE OF COLD AIR
SHOULD PUSH THE FRONT SOUTH OF OUR AREA BY SUNSET TONIGHT. THEN...THE
ARCTIC AIR IS HERE TO STAY. NIGHTTIME LOWS IN THE LOW SINGLE DIGITS
TO MID TEENS...AND DAYTIME HIGHS IN THE TEENS TO 20S WILL BE POSSIBLE
FOLLOWING THE COLD FRONT.
LIGHT SNOW WILL BE POSSIBLE BEFORE MIDNIGHT TONIGHT IN THE WESTERN OK
PANHANDLE AND FAR NW TX PANHANDLE. ACCUMULATIONS OF SNOW SHOULD BE
MINIMAL FROM THIS FIRST ROUND. BY NOON THURSDAY...A MUCH MORE
PRONOUNCED FRONTOGENETIC BAND OF SNOW SHOULD SET UP ROUGHLY FROM
HARTLEY COUNTY TO TEXAS COUNTY. ALL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT ON THE PLACEMENT OF THIS BAND THROUGH TOMORROW AFTERNOON. A
POSSIBLE SECOND BAND SOUTHWARD SHIFT OF THE FIRST COULD BRING
INCREASED SNOW ACCUMULATIONS ALONG A LINE FROM VEGA TO BEAVER HEADING
INTO THE EVENING.
CURRENT THINKING HAS MOST SNOWFALL CLEARING FROM NORTHWEST TO
SOUTHEAST OVERNIGHT THURSDAY INTO FRIDAY...WITH THE LAST ACCUMULATING
SNOW FALLING IN THE SOUTHEAST TEXAS PANHANDLE BETWEEN MIDNIGHT FRIDAY
TO 6 AM THAT MORNING. SOME PERIODS OF FLURRIES COULD LINGER BEHIND
UNTIL DRIER MID LEVEL AIR FINALLY BUILDS OVER THE PANHANDLES.
OVERALL...WE ARE EXPECTING AVERAGE AMOUNTS OF 1 TO 3 INCHES OF SNOW
ACROSS THE PANHANDLES FROM TONIGHT THROUGH FRIDAY MORNING...WITH
LOCALLY HIGHER AMOUNTS UP TO 5 INCHES POSSIBLE UNDER HEAVIER SNOW
BANDS. A WINTER WEATHER ADVISORY WILL BE ISSUED TO ADDRESS THIS
SNOWFALL POTENTIAL.
NF
LONG TERM...FRIDAY THROUGH TUESDAY...
AS THE MAIN SHOT AT SNOW CLEARS THE AREA...THE MAIN STORY THROUGH THE
WEEKEND WILL BE THE PERSISTENT COLDER AIR IN PLACE THROUGH EARLY NEXT
WEEK. THINK NIGHTTIME LOWS IN THE LOW SINGLE DIGITS TO MID TEENS
WILL BE POSSIBLE MOST NIGHTS THROUGH THE MIDDLE OF NEXT WEEK...WITH
DAYTIME HIGHS IN THE TEENS AND TWENTIES THROUGH SATURDAY.
SOUTHWESTERLY WINDS ON SUNDAY MAY HELP TO BRING TEMPERATURES UP TO
NEAR FREEZING...THOUGH THINK CLOUD COVER WILL KEEP MOST PLACES BELOW
FREEZING EVEN ON SUNDAY AND MONDAY. CURRENTLY THINK TUESDAY WILL BE
FIRST CHANCE TO CLIMB ABOVE THE FREEZING MARK. DANGEROUSLY COLD WIND
CHILLS BETWEEN ZERO AND 15 BELOW ZERO WILL BE POSSIBLE DURING THIS
TIME AS WELL.
CANNOT RULE OUT A SLIGHT CHANCE FOR LIGHT SNOW SATURDAY NIGHT INTO
SUNDAY...THOUGH AT THIS TIME THINK ANY ACCUMULATIONS WOULD BE LESS
THAN ONE HALF INCH.
NF
FIRE WEATHER...
ONLY A BRIEF PERIOD OF ELEVATED FIRE WEATHER CONDITIONS WILL BE
POSSIBLE THIS AFTERNOON IN THE FAR SOUTHWEST TEXAS PANHANDLE...SHOULD
THE COLD FRONT IN FACT RETREAT NORTHEAST DURING THE DAY.
OTHERWISE...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE
EXPECTED THROUGH THE MIDDLE OF NEXT WEEK.
NF
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY
FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY
FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
10/16
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1146 AM CST WED DEC 4 2013
.UPDATE...
UPDATE TO REWORK THE WINTER WEATHER ADVISORY. WILL NOW START THE
ADVISORY AT MIDNIGHT TONIGHT AND CONTINUE THROUGH 9 AM FRIDAY. THOUGH
WE ARE NOT EXPECTED SNOW TO LAST THROUGH THIS ENTIRE TIME...WE ALSO
WANTED TO EMPHASIZE THE DANGEROUS WIND CHILL VALUES.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 1038 AM CST WED DEC 4 2013/
UPDATE...
UPDATE TO LOWER TEMPERATURES FOR TODAY. EVEN WITH A SURFACE LOW
DEVELOPING...DO NOT EXPECT THE FRONT TO MAKE MUCH PROGRESS NORTH
GIVEN HOW DENSE THE AIR MASS IS. THUS...THINK ONLY THE EXTREME SW TX
PANHANDLE HAS A CHANCE TO WARM UP SIGNIFICANTLY TODAY.
JOHNSON
PREV DISCUSSION... /ISSUED 556 AM CST WED DEC 4 2013/
AVIATION...
FOR THE 12Z TAFS, THIS IS A LOW CONFIDENCE FORECAST.
A COLD FRONT HAS PASSED THROUGH ALL THE TERMINALS WITH N/NE WINDS
LIKELY TO CONTINUE THROUGH THE REMAINDER OF THIS TAF PERIOD. A
SECONDARY COLD FRONT WILL ARRIVE 00Z-03Z WITH NE WINDS GUSTING UP TO
25 KT.
THE MOST PROBLEMATIC ASPECT OF THIS FORECAST IS FLIGHT CATEGORIES,
AND FORECAST CONFIDENCE IS VERY LOW.
LLWS ASSOCIATED WITH THE COLD FRONT WILL CONTINUE AT KAMA AND KDHT
THROUGH 16Z WHEN WINDS WEAKEN ALOFT. DESPITE THE WEAKENING WINDS
ALOFT, THERE WILL STILL BE AT LEAST A 150 DEGREE WIND SHIFT WITHIN
THE LOWEST 2000 FT THROUGHOUT THIS TAF PERIOD.
-SN WILL BE POSSIBLE AT KDHT AND KGUY AFTER 09Z, BUT DRY AIR NEAR
THE SURFACE MAY ALLOW THIS TO HOLD OFF UNTIL AFTER THIS TAF PERIOD.
JACKSON
PREV DISCUSSION... /ISSUED 534 AM CST WED DEC 4 2013/
DISCUSSION...
THE ANTICIPATED COLD FRONT IS CURRENTLY WORKING SOUTH THROUGH THE
FORECAST AREA...WITH AN EXPECTED SURGE OF ARCTIC AIR LATER TODAY
PLUNGING THE PANHANDLES INTO SUBFREEZING TEMPERATURES THROUGH AT
LEAST THE WEEKEND. A PERIOD OF SNOWFALL WILL BE POSSIBLE FROM LATE
TONIGHT THROUGH EARLY FRIDAY MORNING. FURTHER CHANCES FOR LIGHT SNOW
MAY RETURN LATE IN THE WEEKEND.
SHORT TERM...TODAY THROUGH FRIDAY MORNING...
EVEN AT THIS LATE HOUR...THERE CONTINUES TO BE MODEL DISAGREEMENT
OVER THE TIMING AND POSITION OF THE COLD FRONT TODAY. AT LEAST AN
INITIAL SURGE HAS PUSHED THE FRONT TO THE SOUTH OF OUR CWA THIS
MORNING. THE LATEST RAP CONTINUES TO INDICATE A SLIGHT RETREAT OF THE
FRONT THIS AFTERNOON...ALLOWING FOR THE FAR SOUTHWEST TX PANHANDLE TO
WARM INTO THE UPPER 50S OR LOWER 60S. A FINAL SURGE OF COLD AIR
SHOULD PUSH THE FRONT SOUTH OF OUR AREA BY SUNSET TONIGHT. THEN...THE
ARCTIC AIR IS HERE TO STAY. NIGHTTIME LOWS IN THE LOW SINGLE DIGITS
TO MID TEENS...AND DAYTIME HIGHS IN THE TEENS TO 20S WILL BE POSSIBLE
FOLLOWING THE COLD FRONT.
LIGHT SNOW WILL BE POSSIBLE BEFORE MIDNIGHT TONIGHT IN THE WESTERN OK
PANHANDLE AND FAR NW TX PANHANDLE. ACCUMULATIONS OF SNOW SHOULD BE
MINIMAL FROM THIS FIRST ROUND. BY NOON THURSDAY...A MUCH MORE
PRONOUNCED FRONTOGENETIC BAND OF SNOW SHOULD SET UP ROUGHLY FROM
HARTLEY COUNTY TO TEXAS COUNTY. ALL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT ON THE PLACEMENT OF THIS BAND THROUGH TOMORROW AFTERNOON. A
POSSIBLE SECOND BAND SOUTHWARD SHIFT OF THE FIRST COULD BRING
INCREASED SNOW ACCUMULATIONS ALONG A LINE FROM VEGA TO BEAVER HEADING
INTO THE EVENING.
CURRENT THINKING HAS MOST SNOWFALL CLEARING FROM NORTHWEST TO
SOUTHEAST OVERNIGHT THURSDAY INTO FRIDAY...WITH THE LAST ACCUMULATING
SNOW FALLING IN THE SOUTHEAST TEXAS PANHANDLE BETWEEN MIDNIGHT FRIDAY
TO 6 AM THAT MORNING. SOME PERIODS OF FLURRIES COULD LINGER BEHIND
UNTIL DRIER MID LEVEL AIR FINALLY BUILDS OVER THE PANHANDLES.
OVERALL...WE ARE EXPECTING AVERAGE AMOUNTS OF 1 TO 3 INCHES OF SNOW
ACROSS THE PANHANDLES FROM TONIGHT THROUGH FRIDAY MORNING...WITH
LOCALLY HIGHER AMOUNTS UP TO 5 INCHES POSSIBLE UNDER HEAVIER SNOW
BANDS. A WINTER WEATHER ADVISORY WILL BE ISSUED TO ADDRESS THIS
SNOWFALL POTENTIAL.
NF
LONG TERM...FRIDAY THROUGH TUESDAY...
AS THE MAIN SHOT AT SNOW CLEARS THE AREA...THE MAIN STORY THROUGH THE
WEEKEND WILL BE THE PERSISTENT COLDER AIR IN PLACE THROUGH EARLY NEXT
WEEK. THINK NIGHTTIME LOWS IN THE LOW SINGLE DIGITS TO MID TEENS
WILL BE POSSIBLE MOST NIGHTS THROUGH THE MIDDLE OF NEXT WEEK...WITH
DAYTIME HIGHS IN THE TEENS AND TWENTIES THROUGH SATURDAY.
SOUTHWESTERLY WINDS ON SUNDAY MAY HELP TO BRING TEMPERATURES UP TO
NEAR FREEZING...THOUGH THINK CLOUD COVER WILL KEEP MOST PLACES BELOW
FREEZING EVEN ON SUNDAY AND MONDAY. CURRENTLY THINK TUESDAY WILL BE
FIRST CHANCE TO CLIMB ABOVE THE FREEZING MARK. DANGEROUSLY COLD WIND
CHILLS BETWEEN ZERO AND 15 BELOW ZERO WILL BE POSSIBLE DURING THIS
TIME AS WELL.
CANNOT RULE OUT A SLIGHT CHANCE FOR LIGHT SNOW SATURDAY NIGHT INTO
SUNDAY...THOUGH AT THIS TIME THINK ANY ACCUMULATIONS WOULD BE LESS
THAN ONE HALF INCH.
NF
FIRE WEATHER...
ONLY A BRIEF PERIOD OF ELEVATED FIRE WEATHER CONDITIONS WILL BE
POSSIBLE THIS AFTERNOON IN THE FAR SOUTHWEST TEXAS PANHANDLE...SHOULD
THE COLD FRONT IN FACT RETREAT NORTHEAST DURING THE DAY.
OTHERWISE...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE
EXPECTED THROUGH THE MIDDLE OF NEXT WEEK.
NF
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY
FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM CST FRIDAY
FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
10/16
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1135 AM CST WED DEC 4 2013
.DISCUSSION...
See 18Z aviation discussion below.
&&
.AVIATION...
Expect VFR condition to persist through the evening hours. As the
arctic front moves through 09Z tomorrow morning expect MVFR cigs
to develop. IFR cigs will likely develop later in the day, but
will leave that for the 00Z TAF package. This afternoon the
southern terminals could see some southwest wind gusts but are not
expected to last long enough to include in the TAF package.
&&
.PREV DISCUSSION... /ISSUED 841 AM CST Wed Dec 4 2013/
UPDATE...
Updated temperatures and winds across the northern Big Country.
DISCUSSION...
Initial cold front has dropped into the northern Big Country
counties of Haskell and Throckmorton. Latest RUC and NAM data
suggests that the temperatures behind the front will still climb
today, but just not as fast. Have lowered afternoon highs and
adjusted temperatures and winds for the rest of the day.
Models suggest the front will approach Abilene this afternoon and
then stall. Will not bring it in at this point, but will continue to
monitor.
PREV DISCUSSION... /ISSUED 558 AM CST WED DEC 4 2013/
AVIATION...
/12Z TAFS/
Expect VFR conditions at the terminals during the next 24 hours as
high clouds stream northeast across West Central Texas. The winds
will be southwest to west with gusts to near 20 knots this
afternoon. Also, a cold front will move to just south of the I-20
corridor by late tonight, and have shifted the wind to the north at
the KABI terminal after 06Z Thursday.
21
PREV DISCUSSION... /ISSUED 510 AM CST WED DEC 4 2013/
SHORT TERM...
Today
Look for one more day of unseasonably warm afternoon highs.
Temperatures at 850 mb increase again this afternoon across West
Central Texas. Although cloud cover will be increasing today, gusty
west, down-slope, winds will help push afternoon highs into the mid
to upper 70s across the Big Country and into the 80 to 85 range
elsewhere.
Huber
Tonight
Another strong cold front will move into the Big country around
midnight tonight. The NAM continues to be faster than the GFS. Our
wind grids reflect a timing closer to the faster NAM; thus, I expect
north surface winds to dominate the Big Country north of Interstate
20 by midnight tonight. Thus, lows there tonight will be mainly in
the 30 to 35 range. Elsewhere, 40s look good.
Huber
Thursday through Friday night
Unseasonably cold temperatures and a wintry precipitation mix will
dominate the remainder of the short term. Well, we`ve closely
watched the models develop this next arctic system for the last
several days, and we`re becoming more confident with accumulations
of sleet or freezing rain which may exceed our one quarter inch
warning threshold, mainly across the Big Country. I did note model
forecast sounding are indicating much deeper saturation in the
column, as compared to this time last night. So, with greater
confidence for significant accumulation, we have a Winter Storm
Watch in effect for all our Big Country counties. The latest
Weather Prediction Center guidance indicates possible
accumulations across mainly our Big Country counties of at least
one quarter inch. Elsewhere across West Central Texas, my
confidence is not as high for any accumulations close to one
quarter inch. Thus, we will continue a Special Weather Statement
for our remaining counties. The best chance for precipitation will
be Thursday night, as an upper trough moves over the region. As if
the ice and sleet accumulations weren`t enough, I`m also concerned
about temperatures Thursday night and corresponding wind chill,
especially across the Big Country. With lows in the teens there,
gusty north winds will create very dangerous wind chill numbers
around zero degrees. On Friday, strong cold air advection
continues, with surface winds from the north around 15 mph. The
wintry precipitation mix will continue until around noon; then,
the upper trough axis moves east of our area. Overnight Friday
night, very dangerous wind chill numbers will again dominate the
Big Country and even parts of the Concho valley and Heartland.
With north surface winds continuing Friday night, cold air
advection will create colder lows than Thursday night.
Huber
LONG TERM...
Saturday through Sunday
Unseasonably cold temperatures will continue through the weekend. As
a very dominate arctic airmass settles over Texas for the weekend,
unseasonably cold temperatures will continue. Highs Saturday will
likely remain at or just below freezing for most of West Central
Texas. Thus, any remaining ice will likely be slow to melt, if it
melts at all. Another short wave aloft will move across the southern
plains on Saturday and perhaps bring another brief round of wintry
precipitation to West central Texas. My confidence isn`t very high
regarding the potential for additional precipitation with this
secondary short wave; thus, I`ve continued only slight chance PoPs
for the Saturday period. As for temperatures, Sunday doesn`t look
much better. Returning sunshine Sunday will help lift temperatures
above the freezing mark for the afternoon hours. Nevertheless, highs
in the lower 30s for much of the Big Country on Sunday aren`t what
I`d call warm!
Huber
Sunday night through Tuesday
For the start of next week, temperatures do begin to rebound just
slightly; but, they remain well below seasonal normals.
Huber
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 27 31 20 25 15 / 30 60 70 30 10
San Angelo 41 42 24 31 20 / 20 50 70 20 10
Junction 48 52 26 33 24 / 20 40 70 30 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from Thursday afternoon through Friday
morning FOR THE FOLLOWING ZONES: Callahan...Fisher...Haskell...
Jones...Nolan...Shackelford...Taylor...Throckmorton.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1038 AM CST WED DEC 4 2013
.UPDATE...
UPDATE TO LOWER TEMPERATURES FOR TODAY. EVEN WITH A SURFACE LOW
DEVELOPING...DO NOT EXPECT THE FRONT TO MAKE MUCH PROGRESS NORTH
GIVEN HOW DENSE THE AIR MASS IS. THUS...THINK ONLY THE EXTREME SW TX
PANHANDLE HAS A CHANCE TO WARM UP SIGNIFICANTLY TODAY.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 556 AM CST WED DEC 4 2013/
AVIATION...
FOR THE 12Z TAFS, THIS IS A LOW CONFIDENCE FORECAST.
A COLD FRONT HAS PASSED THROUGH ALL THE TERMINALS WITH N/NE WINDS
LIKELY TO CONTINUE THROUGH THE REMAINDER OF THIS TAF PERIOD. A
SECONDARY COLD FRONT WILL ARRIVE 00Z-03Z WITH NE WINDS GUSTING UP TO
25 KT.
THE MOST PROBLEMATIC ASPECT OF THIS FORECAST IS FLIGHT CATEGORIES,
AND FORECAST CONFIDENCE IS VERY LOW.
LLWS ASSOCIATED WITH THE COLD FRONT WILL CONTINUE AT KAMA AND KDHT
THROUGH 16Z WHEN WINDS WEAKEN ALOFT. DESPITE THE WEAKENING WINDS
ALOFT, THERE WILL STILL BE AT LEAST A 150 DEGREE WIND SHIFT WITHIN
THE LOWEST 2000 FT THROUGHOUT THIS TAF PERIOD.
-SN WILL BE POSSIBLE AT KDHT AND KGUY AFTER 09Z, BUT DRY AIR NEAR
THE SURFACE MAY ALLOW THIS TO HOLD OFF UNTIL AFTER THIS TAF PERIOD.
JACKSON
PREV DISCUSSION... /ISSUED 534 AM CST WED DEC 4 2013/
DISCUSSION...
THE ANTICIPATED COLD FRONT IS CURRENTLY WORKING SOUTH THROUGH THE
FORECAST AREA...WITH AN EXPECTED SURGE OF ARCTIC AIR LATER TODAY
PLUNGING THE PANHANDLES INTO SUBFREEZING TEMPERATURES THROUGH AT
LEAST THE WEEKEND. A PERIOD OF SNOWFALL WILL BE POSSIBLE FROM LATE
TONIGHT THROUGH EARLY FRIDAY MORNING. FURTHER CHANCES FOR LIGHT SNOW
MAY RETURN LATE IN THE WEEKEND.
SHORT TERM...TODAY THROUGH FRIDAY MORNING...
EVEN AT THIS LATE HOUR...THERE CONTINUES TO BE MODEL DISAGREEMENT
OVER THE TIMING AND POSITION OF THE COLD FRONT TODAY. AT LEAST AN
INITIAL SURGE HAS PUSHED THE FRONT TO THE SOUTH OF OUR CWA THIS
MORNING. THE LATEST RAP CONTINUES TO INDICATE A SLIGHT RETREAT OF THE
FRONT THIS AFTERNOON...ALLOWING FOR THE FAR SOUTHWEST TX PANHANDLE TO
WARM INTO THE UPPER 50S OR LOWER 60S. A FINAL SURGE OF COLD AIR
SHOULD PUSH THE FRONT SOUTH OF OUR AREA BY SUNSET TONIGHT. THEN...THE
ARCTIC AIR IS HERE TO STAY. NIGHTTIME LOWS IN THE LOW SINGLE DIGITS
TO MID TEENS...AND DAYTIME HIGHS IN THE TEENS TO 20S WILL BE POSSIBLE
FOLLOWING THE COLD FRONT.
LIGHT SNOW WILL BE POSSIBLE BEFORE MIDNIGHT TONIGHT IN THE WESTERN OK
PANHANDLE AND FAR NW TX PANHANDLE. ACCUMULATIONS OF SNOW SHOULD BE
MINIMAL FROM THIS FIRST ROUND. BY NOON THURSDAY...A MUCH MORE
PRONOUNCED FRONTOGENETIC BAND OF SNOW SHOULD SET UP ROUGHLY FROM
HARTLEY COUNTY TO TEXAS COUNTY. ALL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT ON THE PLACEMENT OF THIS BAND THROUGH TOMORROW AFTERNOON. A
POSSIBLE SECOND BAND SOUTHWARD SHIFT OF THE FIRST COULD BRING
INCREASED SNOW ACCUMULATIONS ALONG A LINE FROM VEGA TO BEAVER HEADING
INTO THE EVENING.
CURRENT THINKING HAS MOST SNOWFALL CLEARING FROM NORTHWEST TO
SOUTHEAST OVERNIGHT THURSDAY INTO FRIDAY...WITH THE LAST ACCUMULATING
SNOW FALLING IN THE SOUTHEAST TEXAS PANHANDLE BETWEEN MIDNIGHT FRIDAY
TO 6 AM THAT MORNING. SOME PERIODS OF FLURRIES COULD LINGER BEHIND
UNTIL DRIER MID LEVEL AIR FINALLY BUILDS OVER THE PANHANDLES.
OVERALL...WE ARE EXPECTING AVERAGE AMOUNTS OF 1 TO 3 INCHES OF SNOW
ACROSS THE PANHANDLES FROM TONIGHT THROUGH FRIDAY MORNING...WITH
LOCALLY HIGHER AMOUNTS UP TO 5 INCHES POSSIBLE UNDER HEAVIER SNOW
BANDS. A WINTER WEATHER ADVISORY WILL BE ISSUED TO ADDRESS THIS
SNOWFALL POTENTIAL.
NF
LONG TERM...FRIDAY THROUGH TUESDAY...
AS THE MAIN SHOT AT SNOW CLEARS THE AREA...THE MAIN STORY THROUGH THE
WEEKEND WILL BE THE PERSISTENT COLDER AIR IN PLACE THROUGH EARLY NEXT
WEEK. THINK NIGHTTIME LOWS IN THE LOW SINGLE DIGITS TO MID TEENS
WILL BE POSSIBLE MOST NIGHTS THROUGH THE MIDDLE OF NEXT WEEK...WITH
DAYTIME HIGHS IN THE TEENS AND TWENTIES THROUGH SATURDAY.
SOUTHWESTERLY WINDS ON SUNDAY MAY HELP TO BRING TEMPERATURES UP TO
NEAR FREEZING...THOUGH THINK CLOUD COVER WILL KEEP MOST PLACES BELOW
FREEZING EVEN ON SUNDAY AND MONDAY. CURRENTLY THINK TUESDAY WILL BE
FIRST CHANCE TO CLIMB ABOVE THE FREEZING MARK. DANGEROUSLY COLD WIND
CHILLS BETWEEN ZERO AND 15 BELOW ZERO WILL BE POSSIBLE DURING THIS
TIME AS WELL.
CANNOT RULE OUT A SLIGHT CHANCE FOR LIGHT SNOW SATURDAY NIGHT INTO
SUNDAY...THOUGH AT THIS TIME THINK ANY ACCUMULATIONS WOULD BE LESS
THAN ONE HALF INCH.
NF
FIRE WEATHER...
ONLY A BRIEF PERIOD OF ELEVATED FIRE WEATHER CONDITIONS WILL BE
POSSIBLE THIS AFTERNOON IN THE FAR SOUTHWEST TEXAS PANHANDLE...SHOULD
THE COLD FRONT IN FACT RETREAT NORTHEAST DURING THE DAY.
OTHERWISE...NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE
EXPECTED THROUGH THE MIDDLE OF NEXT WEEK.
NF
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY FROM 3 PM THURSDAY TO 6 AM CST FRIDAY
FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DEAF SMITH...DONLEY...GRAY...HANSFORD...
HEMPHILL...HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...
OLDHAM...POTTER...RANDALL...ROBERTS...WHEELER.
WINTER WEATHER ADVISORY FROM 4 AM THURSDAY TO MIDNIGHT CST
THURSDAY NIGHT FOR THE FOLLOWING ZONES: DALLAM...HARTLEY...
SHERMAN.
OK...WINTER WEATHER ADVISORY FROM 3 PM THURSDAY TO 6 AM CST FRIDAY
FOR THE FOLLOWING ZONES: BEAVER.
WINTER WEATHER ADVISORY FROM 4 AM THURSDAY TO MIDNIGHT CST
THURSDAY NIGHT FOR THE FOLLOWING ZONES: CIMARRON...TEXAS.
&&
$$
10/16
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
316 PM CST WED DEC 4 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY MORNING)
ISSUED AT 316 PM CST WED DEC 4 2013
MAIN FORECAST CONCERN IS ON DEPARTING WEATHER SYSTEM...FOLLOWED
BY THE ARCTIC AIR MASS SURGE.
AS OF 3 PM WEDNESDAY...SURFACE ANALYSIS SHOWED 998 MB LOW
PRESSURE CENTERED NEAR DECORAH IOWA...WITH A WARM FRONT SITUATED
FROM NEAR PRAIRIE DU CHIEN WISCONSIN EASTWARD INTO SOUTHERN
WISCONSIN. FINALLY...THE LEADING EDGE OF THE COLD AIR WAS ALONG
THE I-35 CORRIDOR IN MINNESOTA AND IOWA.
THE SURFACE LOW IS EXPECTED TO LIFT NORTHEAST TO NORTHERN WISCONSIN
LATER THIS EVENING...THEN OVER LAKE SUPERIOR BY MIDNIGHT. THE COLD
FRONT SHOULD MAKE A CLEAN SWEEP ACROSS THE ENTIRE FORECAST AREA BY
03Z. THE SURGE OF WARMER AIR AHEAD OF THE SURFACE LOW IS KEEPING
WINTER PRECIPITATION THREAT LOW AT THIS TIME BUT STILL PLENTY OF
1/4 SM VISIBILITIES OR LOWER. LOCATIONS WILL HAVE TO WAIT FOR THE
COLD FRONTAL PASSAGE FOR IMPROVED VISIBILITIES...AND AREAS EAST OF
THE MISSISSIPPI RIVER AND NORTH OF I-90 IN WISCONSIN WILL LIKELY
HANG ONTO THE REDUCED VISIBILITIES THE LONGEST.
AHEAD OF THE COLD FRONT...STRONG LOW LEVEL LIFT AND SATURATION
COMBINED WITH VERY LITTLE ICE SATURATION ALOFT WILL LIKELY LEAD TO
DRIZZLE. HIGH RES MODELS SUCH AS THE HRRR CAPTURE THIS FAIRLY WELL.
BEHIND THE COLD FRONT...TEMPERATURES QUICKLY FALL INTO THE UPPER 20S
TO NEAR 30 DEGREES. ALTHOUGH MOISTURE IS TRAPPED IN THE LOW-LEVEL
INVERSION...THE LIFT BEGINS TO DROP OFF BUT THERE IS LIKELY TO BE
A PERIOD OF FREEZING DRIZZLE. AS EVEN COLDER AIR WORKS IN
ALOFT...SATURATION IN THE ICE GROWTH LAYER RETURNS SO PRECIPITATION
COULD END AS SNOW FLURRIES OR SNOW SHOWERS...ESPECIALLY ACROSS
CENTRAL MINNESOTA...INTO NORTH CENTRAL WISCONSIN BEFORE TAPERING
OFF ALTOGETHER TOWARD MIDNIGHT. AS SUCH...THE WINTER WEATHER
ADVISORY FOR TAYLOR/CLARK COUNTIES WILL REMAIN IN PLACE BUT LIKELY
COULD BE ENDED TOWARD MIDNIGHT.
FOR THURSDAY MORNING...GOOD CONSENSUS THAT PLENTY OF MOISTURE
REMAINS TRAPPED IN THE LOW LEVELS...MAINLY CENTERED AROUND 900 MB.
LIFT IS VERY WEAK BUT THE SURGE OF ARCTIC AIR SHOULD PUT THE DGZ
CLOSER TO 900 MB. THIS SUPPORTS VERY LIGHT BUT OCCASIONAL TO PERIODS
OF SNOW FLURRIES ACROSS NORTH CENTRAL WISCONSIN...BECOMING MORE
SCATTERED CLOSER TO ROCHESTER AND LA CROSSE.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 316 PM CST WED DEC 4 2013
HIGHLIGHTS IN THE LONG TERM ARE ARCTIC AIR MASS SURGES AND
ACCUMULATING SNOWFALL POTENTIAL SUNDAY NIGHT.
THE CURRENT STORM SYSTEM DEEPENS AND QUICKLY DEPARTS NORTHEAST OF
THE GREAT LAKES REGION THURSDAY WHILE THE WESTERN TWO-THIRDS OF THE
CONUS REMAINS UNDER THE INFLUENCE OF THE UPPER LEVEL LONGWAVE
TROUGH. AS WELL ADVERTISED PREVIOUSLY...THE ARCTIC AIR SURGE
BEGINS IN EARNEST THURSDAY AND FRIDAY AS NOTED BY 850 MB
TEMPERATURES FALLING FROM AN AVERAGE OF -8C 12Z THURSDAY...TO -17C
BY 18Z FRIDAY. 850 MB STANDARDIZED ANOMALIES FALL TO 2 TO 2.5
DEGREES BELOW NORMAL...WHICH IS NOT RECORD COLD TERRITORY BUT
CERTAINLY UNSEASONABLE FOR THIS TIME OF YEAR. THE FRESH SNOWPACK
ACROSS CENTRAL MINNESOTA INTO NORTH CENTRAL WISCONSIN IS LIKELY TO
KEEP TEMPERATURES ON THE LOWER SIDE OF GUIDANCE AS WELL. LATEST
SNOW DEPTH READINGS SHOW ANYWHERE FROM A FEW INCHES FROM SOUTH CENTRAL
MINNESOTA...TO ALMOST 10 INCHES IN TAYLOR COUNTY. FORECAST
TEMPERATURES WERE NUDGED DOWN SLIGHTLY BY A FEW DEGREES FROM
PREVIOUS FORECAST.
A NOTICEABLY COLDER DAY ON TAP THURSDAY...WITH HIGHS ONLY IN THE
TEENS TO LOWER 20S. STIFF NORTHWEST WINDS WILL MAKE FOR WIND CHILL
READINGS IN THE SINGLE DIGITS ABOVE ZERO AT TIMES FOR MUCH OF THE
DAY. EVEN COLDER TEMPERATURES ARE EXPECTED FRIDAY AND
SATURDAY...MAINLY SINGLE DIGITS TO TEENS. FOR REFERENCE...NORMAL
HIGHS FOR THIS TIME OF YEAR ARE IN THE UPPER 20S TO LOWER 30S AND
LOWS IN THE TEENS. AS FAR AS LOW TEMPERATURES GO...SEVERAL
MORNINGS OF SUB ZERO READINGS EXPECTED FOR PARTS OF SOUTHEAST
MINNESOTA INTO NORTH CENTRAL WISCONSIN WHILE THE REST OF THE AREA
SHOULD FALL INTO THE SINGLE DIGITS ABOVE ZERO.
A WIND CHILL ADVISORY IS LIKELY NEEDED FOR PARTS OF THE AREA FRIDAY
NIGHT INTO SATURDAY AS THE SURFACE HIGH PRESSURE DROPS SOUTH TO OUR
WEST. THIS KEEPS A 10 TO 15 MPH WIND DURING THE OVERNIGHT ACROSS THE
AREA...RESULTING IN WIND CHILL READINGS IN THE 15 TO 25 DEGREE BELOW
ZERO RANGE NORTH OF INTERSTATE 90.
FOR THE UPCOMING WEEKEND...SATURDAY LOOKS TO BE ANOTHER UNSEASONABLY
COLD BUT DRY DAY WITH HIGHS IN THE SINGLE DIGITS TO TEENS.
HOWEVER...ON SUNDAY WITH THE MAIN UPPER LEVEL TROUGH REMAINING IN
PLACE ACROSS THE WESTERN CONUS...ANOTHER PIECE OF UPPER LEVEL ENERGY
DIGS INTO THE SOUTHWEST U.S. WHICH IS EXPECTED TO ALLOW A SURFACE
LOW TO DEVELOP IN THE LEE SIDE OF THE ROCKIES. PREVIOUS MODEL
CYCLES...AND THE 04.12Z GUIDANCE CONTINUE TO SHOW VERY GOOD
AGREEMENT THIS FAR OUT WHICH BOOSTS CONFIDENCE DURING THIS PERIOD.
THE SURFACE LOW IS EXPECTED TO BE NEAR CENTRAL OKLAHOMA 18Z
SUNDAY...THEN MOVE TOWARD CENTRAL ILLINOIS BY 06Z MONDAY. ON THE
NORTHWEST SIDE...AN INVERTED SURFACE TROUGH COUPLED WITH THE UPPER
LEVEL ENERGY IS LIKELY TO PROVIDE PLENTY OF LIFT TO SUPPORT SNOW
ACROSS MUCH OF THE FORECAST AREA. PRECIPITATION CHANCES WERE BOOSTED
TO LIKELY ACROSS NORTHEAST IOWA INTO WESTERN AND SOUTHERN
WISCONSIN...AND INTO THE 40 TO 50 PERCENT RANGE ELSEWHERE. STILL TOO
EARLY TO SPECULATE ON SNOWFALL AMOUNTS...BUT IMPACTFUL WEATHER IS
LOOKING LIKELY SUNDAY AFTERNOON INTO MONDAY MORNING FOR PORTIONS
OF THE AREA.
IN THE WAKE OF THE LATE WEEKEND SYSTEM...ANOTHER SURGE OF ARCTIC AIR
WILL USHER IN EVEN COLDER AIR WITH 850 MB TEMPERATURES IN THE -20 TO
-25C RANGE. AIDED BY A POSSIBLE FRESH SNOWPACK...WIDESPREAD MORNING
TEMPERATURES IN THE SINGLE DIGITS BELOW ZERO ARE LIKELY WITH TEENS
BELOW ZERO POSSIBLE IN SPOTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1112 AM CST WED DEC 4 2013
LITTLE CHANGE IN CONDITIONS ARE EXPECTED TO OCCUR UNTIL THE COLD
FRONT MOVES THROUGH THIS AFTERNOON. THIS WILL KEEP THE CEILINGS
AND VISIBILITIES DOWN IN THE IFR CATEGORY THROUGH AT LEAST MID
AFTERNOON AT KRST AND TO AROUND 00Z AT KLSE. ONCE THE FRONT COMES
THROUGH AND THE WINDS COME AROUND TO THE WEST...THE VISIBILITY
WILL GRADUALLY INCREASE AND SHOULD JUMP TO VFR AS THE WINDS BECOME
SUSTAINED OVER 10 KNOTS WITH GUSTS BETWEEN 20 AND 30 KNOTS. LOOKS
LIKE THE LOW LEVEL MOISTURE WILL GET TRAPPED UNDER THE INVERSION
SO ONLY EXPECTING THE CEILINGS TO COME UP TO MVFR AT BEST. OUTSIDE
OF SOME DRIZZLE AHEAD OF THE FRONT...NOT EXPECTING A LOT OF
PRECIPITATION TO OCCUR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ032>034-
041>044-053>055-061.
WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR WIZ017-029.
MN...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ088-096.
IA...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ011-030.
&&
$$
SHORT TERM...ZT
LONG TERM...ZT
AVIATION...04
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1030 AM CST WED DEC 4 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 1030 AM CST WED DEC 4 2013
LOW PRESSURE SYSTEM WAS NEAR KIRKSVILLE MISSOURI AT 15Z.
BEST 3 HOURLY PRESSURE FALLS WERE OVER EAU CLAIRE SO THAT`S WHERE
THIS SYSTEM SHOULD BE HEADED IN THE NEXT SEVERAL HOURS. SURFACE
OBSERVATIONS SUGGEST THAT WARM AIR AROUND 850MB HAS MOVED INTO
NORTHERN WISCONSIN AND CAUSED A CHANGEOVER FROM SNOW TO FREEZING
RAIN OR SLEET SOUTH OF A RHINELANDER TO IRON MOUNTAIN LINE. MODELS
FORECAST 850MB TEMPERATURES TO CONTINUE CLIMBING WITH SOUTHERLY
FLOW SO BACKED OFF ON SNOW ACCUMULATIONS AND INCREASED AMOUNT OF
FREEZING RAIN AND FREEZING DRIZZLE. WILL EXTEND THE WINTER WEATHER
ADVISORY FOR MARATHON, LINCOLN AND LANGLADE COUNTIES THROUGH THE
AFTERNOON AS TEMPERATURES WILL BE SLOW TO CLIMB ABOVE FREEZING.
&&
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 427 AM CST WED DEC 4 2013
FOCUS IS ON PCPN TYPES AND AMOUNTS TODAY...THEN FALLING
TEMPERATURES TONIGHT AND THU.
MODELS ARE IN BETTER AGREEMENT TONIGHT...USED A BLEND...LEANING A
BIT MORE ON ECMWF FOR THIS PERIOD. MADE EARLIER CHANGE TO
HEADLINES WITH ISSUANCE OF WINTER WEATHER ADVISORY FOR CENTRAL WI
AS TEMPERATURES NOT MOVING ABOVE FREEZING...ACTUALLY DROPPED. LIGHT
PCPN CONTINUES TO LIFT NORTH INTO CWA. CALLS TO PORTAGE AND WOOD
COUNTIES INDICATED ICING ISSUES ON ROADS. LOOKING FOR
TEMPERATURES TO MOVE ABOVE FREEZING MID MORNING.
RADAR MOSAIC SHOWING AREA OF SNOW MAKING BEELINE FOR NORTH CENTRAL
WI THIS MORNING WITH RAP BRINGING IT INTO CWA AROUND 6AM.
TEMPERATURE PROFILES SUGGEST MOSTLY SNOW OVER NORTHERN WI THROUGH
18Z...THEN START TO MIX...LIMITING SNOW TOTALS. STILL LOOKING FOR
5 TO 7 INCHES WESTERN AREAS OF VILAS...SO WILL KEEP WARNING AS IS. NO
CHANGES PLANNED FOR CURRENT HEADLINES. TO THE SOUTH...INCREASING
DEW POINTS OVER FRESH SNOW FROM PREVIOUS EVENING TO LEAD TO DENSE
FOG FORMATION...MAINLY EAST CENTRAL. MODELS A BIT FAST BRINGING
MOISTURE NORTH...SO PUSHED BACK TIMING IN GRIDS. WILL PLAY WATCH
AND SEE A BIT LONGER BEFORE ISSUING ANY HEADLINE GIVEN NUMBER OF
HEADLINES OUT RIGHT NOW.
STRONG COLD FRONT TO MOVE THROUGH TONIGHT...WITH WED MIN/THU MAX
AROUND 12Z THU. USED NON DIURNAL TREND FOR TEMPS FALLING THROUGH
THE DAY. APPARENT TEMPS ONLY IN SINGLE DIGITS ABOVE OR BELOW ZERO
FOR MUCH OF THU. BACKED OFF A BIT ON POPS FOR LAKE EFFECT SNOWS
FAR NORTH THU WITH WINDS TOO WESTERLY IN DIRECTION.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 427 AM CST WED DEC 4 2013
MDLS CONT TO ADVERTISE AN AMPLIFIED MEAN FLOW THAT CONSISTED OF AN
ALASKA UPR RDG...A DEEP POSITIVE-TILTED LONGWAVE TROF FROM NRN
CANADA TO THE SW CONUS AND UPR RIDGING FROM FLORIDA INTO THE WRN
ATLANTIC. THIS PATTERN TO HOLD STEADY THRU THE UPCOMING WEEKEND
BEFORE THE ALASKA RDG BREAKS DOWN AND THE UPR TROF SHIFTS INTO THE
CNTRL CONUS BY THE END OF THE FCST PERIOD. A DRY AND VERY COLD AIR
MASS TO DEVELOP OVER NE WI THRU SAT NGT BEFORE THE NEXT SYSTEM IN
THE SW FLOW ALOFT ARRIVES LATE SUNDAY INTO MON. ANOTHER SURGE OF
ARCTIC AIR TO THEN OVERSPREAD THE REGION FOR THE MIDDLE OF NEXT
WEEK WITH TEMPS 20 TO 30 DEGS BELOW NORMAL.
LARGE ARCTIC HI PRES TO EXTEND FROM BRITISH COLUMBIA SEWD INTO THE
NRN/CNTRL PLAINS THU NGT WITH AN EWD EXTENT REACHING INTO THE
GREAT LAKES. THIS WOULD BRING PARTLY CLOUDY SKIES AND UNSEASONABLY
COLD CONDITIONS TO NE WI WITH TEMPS DROPPING BELOW ZERO OVER NRN/
PARTS OF CNTRL WI...WHILE LAKESHORE AREAS DIP INTO THE UPR SINGLE
DIGITS. ADD IN A WEST WIND AT 10 TO 15 MPH AND WE ARE LOOKING AT
WIND CHILL VALUES RANGING FROM 5 BELOW TO 20 BELOW ZERO BY
DAYBREAK. WL NEED TO WATCH N-CNTRL WI FOR A POSSIBLE WIND CHILL
ADVY IF WINDS CAN REMAIN STRONG ENUF.
QUIET AND VERY COLD CONDITIONS CONT THRU FRI AS THE ARCTIC HI TO
DOMINATE THE MIDDLE OF THE COUNTRY. THIS SFC HI WL KEEP A SYSTEM
MOVING FROM THE DEEP SOUTH TO THE MID-ATLANTIC STATES ADN NOT HAVE
ANY IMPACT ON OUR WEATHER. MAX TEMPS WL NOT GET OUT OF THE SINGLE
DIGITS OVER N-CNTRL WI...WITH TEENS EXPECTED ELSEWHERE. THIS WOULD
BE ABOUT 15 DEGS BELOW NORMAL.
THE ERN FLANK OF THE ARCTIC HI EDGES INTO THE WRN GREAT LAKES
REGION FRI NGT WITH A SLIGHT DIMINISH IN WIND SPEEDS. 8H TEMPS TO
HOVER IN THE -18 TO -20C RANGE AND WITH SKY CONDITIONS OF MOSTLY
CLEAR TO PARTLY CLOUDY...TEMPS WL BE EVEN COLDER THAN THU NGT WITH
READINGS FLIRTING WITH DOUBLE DIGITS BELOW ZERO IN THE NORTH...NEAR
ZERO AROUND THE FOX VALLEY AND AROUND 5 ABOVE ZERO NEAR LAKE MI. WE
COULD AGAIN BE LOOKING AT POSSIBLE WIND CHILL ADVYS ACROSS PARTS OF
NE WI AS VALUES FALL BELOW THE -20 DEG THRESHOLD. THE ARCTIC HI IS
FCST TO STRETCH FROM THE NRN HI PLAINS THRU THE GREAT LAKES ON
SAT...THEREBY PROVIDING FOR ANOTHER MOSTLY SUNNY TO PARTLY CLOUDY
DAY WITH TEMPS WELL BELOW NORMAL. IN FACT...MAX TEMPS WL NOT GET
OUT OF THE SINGLE DIGITS OVER NRN AND CNTRL WI AND ONLY IN THE 10
TO 15 DEG RANGE FOR E-CNTRL WI. THESE VALUES WOULD BE AROUND 20
DEGS BELOW NORMAL.
ATTENTION THEN TURNS TOWARD THE CNTRL CONUS LATE IN THE WEEKEND
WHERE A SYSTEM IS PROGGED TO EJECT NEWD OUT OF THE MAIN LONGWAVE
TROF. CLOUDS TO ALREADY BEGIN TO INCREASE SAT NGT...BUT QUESTIONS
REMAIN AS TO HOW FAST MOISTURE WL BE ABLE TO OVERSPREAD WI WITH
THE INITIAL DRY AIR MASS IN PLACE. EVEN WITH A STEADY INCREASE IN
ISEN LIFT THRU THE DAY...BELIEVE IT WL TAKE MOST OF SUNDAY JUST TO
SATURATE...THUS HAVE KEPT POPS ON THE LOW SIDE WITH A SLIGHT UPTICK
IN TEMPS AS 8H TEMPS `WARM` TO AROUND -14C.
AS ONE WOULD EXPECT THIS FAR OUT...THE MDLS ARE TRYING TO ZERO IN
ON THE TRACK OF THE STRENGTHENING AREA OF LOW PRES WHICH WL LIFT
NE TOWARD/INTO THE GREAT LAKES SUNDAY NGT. THE EXACT TRACK WL BE
CRUCIAL WHETHER NE WI SEES JUST LIGHT SNOW OR AN APPRECIABLE
ACCUMULATION WARRANTING A HEADLINE. HAVE RAISED POPS INTO THE HI
CHC CATEGORY FOR CNTRL WI AND LIKELY FOR ERN WI BASED ON THE MDLS
MOVING THE SFC LOW TOWARD ERN SECTIONS OF THE GREAT LAKES. WL NEED
TO WATCH THIS SYSTEM IN THE COMING DAYS AS ANY CHANGE IN STORM
TRACK WOULD AFFECT ACCUMULATION NUMBERS. THE SNOW SHOULD END MON
MORNING AS THE SFC LOW QUICKLY LIFTS NE INTO SE CANADA. ANY
ADDITIONAL ACCUMULATIONS APPEAR TO BE MINOR AT THIS POINT. THE
OTHER STORY FOR MON WL BE THE ONSET OF THE NEXT ARCTIC SURGE AS 8H
TEMPS CRASH THRU THE DAY. TEMPS MAY EASILY BE STEADY OR SLOWLY
FALL WITH LATE DAY TEMPS ALREADY DOWN INTO THE SINGLE DIGITS AND
TEENS.
THE COLDER AIR OF THE WINTER SEASON TO THEN SWEEP ACROSS THE GREAT
LAKES REGION MON NGT INTO TUE WITH 8H TEMPS PLUMMETING TO AS LOW
AS -26C. TOO MUCH OF A WESTERLY COMPONENT TO THE WIND TO BRING
LAKE EFFECT SNOWS INTO NRN WI...THUS AT LEAST A DRY FCST IS
ANTICIPATED. EXACTLY HOW COLD WE GET WL BE DETERMINED BY THE
EXTENT OF THE SNOW COVER OVER THE FCST AREA. BY TUE MORNING...SUB-
ZERO TEMPS COULD COVER ALL BUT THE LAKESHORE AREAS WITH MAX TEMPS
ON TUE PERHAPS NOT GETTING ABOVE ZERO OVER N-CNTRL WI.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 544 AM CST WED DEC 4 2013
GENERALLY POOR FLIGHT CONDITIONS EXPECTED INTO THIS EVENING WITH
SNOW OR A WINTRY MIX NORTH AND FOG SOUTH. LIGHT FREEZING PCPN WILL
AFFECT CENTRAL TAF SITES THROUGH THE MORNING...THOUGH SURFACE
TEMPERATURES ARE EXPECTED TO CLIMB TO ABOVE FREEZING MID MORNING.
BRISK WESTERLY WINDS EXPECTED BEHIND SYSTEM THIS EVENING AND
OVERNIGHT...WITH VISBYS/CIGS IMPROVING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ018>021-030-
031-035>037-045.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
WIZ010>012.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR WIZ005.
&&
$$
UPDATE.........RDM
SHORT TERM.....TE
LONG TERM......KALLAS
AVIATION.......TE