Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/08/14
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
307 PM PST Mon Jan 6 2014
.Synopsis...
High pressure along the west coast will continue dry and warm
weather today. A slight chance of showers will be possible the
remainder of the week, especially over the northern mountains as
a couple of weak low pressure systems move through the region.
&&
.Discussion...
Ridge axis shifting further inland this afternoon and is showing
signs of breaking down ahead of a series of approaching waves.
High clouds associated with the first of these waves moved in
overnight and are continuing to stream in this afternoon.
Temperature modification from these clouds resulted in a warm
start to the day, and now running five to ten degrees cooler than
yesterday. Expect general cloudiness to persist for much of this
week as the dirty ridge pattern persists.
Ridge is forecast to flatten over the next 12 hours and give way
to the first wave of the week. This wave will rotate over and
around the remnants of the ridge and most likely stay out of our
forecast region, however the HRRR model does hint at a few stray
showers in the Northern Sacramento valley tonight. A second wave
arrives midweek and could drop further into California than the
first wave. Uncertainty is higher than average given the weak
organization of these wave. That said, timing on the second wave
is late Wed into early Thursday. The Northern and Central
Sacramento valley as well as the sierra could see some
precipitation from the second wave. Neither system appears to be
especially wet, so any accumulations will be light.
&&
.Extended Discussion (Friday through Monday)
The extended forecast starts with a warm and dry Friday as daytime
highs measure up to around 10 degrees above normal. Models are
indicating that weak, unsettled weather could be impacting NorCal
Saturday and Sunday with slightly cooler temperatures. However, discrepancies
exist between the models. The ECMWF continues to be the more
bullish showing a deeper trough and wetter conditions (though
precipitation amounts are still not impressive) that last most of
the weekend. The GFS and GEM show a quick moving weak storm that
brushes NorCal Saturday morning into afternoon then becoming dry
again for Sunday. Have kept slight chance to chance of
precipitation for Saturday across most of our CWA and then only a
slight chance in the northern half of our CWA on Sunday. All
models show another ridge building back over the West Coast by
early Monday. JBB
&&
.Aviation...
Predominantly VFR across interior NorCal next 24 hours, except
areas of MVFR with haze and patchy BR overnight in the Northern
San Joaquin Valley including KSCK. Variable high clouds into this
evening as a weak trough approaches the west coast. Light winds
continue. -DVC
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
916 AM PST Mon Jan 6 2014
.Synopsis...
High pressure along the west coast will continue dry and warm
weather today. A slight chance of showers will be possible the
remainder of the week, especially over the northern mountains as
a couple of weak low pressure systems move through the region.
&&
.Discussion...
Ridge axis shifting inland this morning and is beginning to show
signs of breaking down ahead of a series of approaching waves. High
clouds associated with the first of these waves moved in overnight and
have contributed to slightly warmer temperatures across most locations
this morning. Likewise, daytime highs will be moderated by the
clouds. Redding is running 22 degrees cooler this morning than
yesterday morning, but this is more of a result of weaker winds
than any other factors.
Ridge is forecast to flatten over the next 24 hours and give way
to the first wave of the week. This wave will rotate over and
around the remnants of the ridge and most likely stay out of our
forecast region, however the HRRR model does hint at a few stray
showers in the Northern Sacramento valley tonight. A second wave
arrives midweek and could drop further into California than the
first wave. Uncertainty is higher than average given the weak
organization of these wave. That said, timing on the second wave
is late Wed into early Thursday. The Northern and Central
Sacramento valley as well as the sierra could see some
precipitation from the second wave. Neither system appears to be
especially wet, so any accumulations will be light.
&&
.Extended Discussion (Friday through Monday)
Dry and warmer on Friday as the persistent ridge briefly re-
strengthens with the axis moving inside of 130W. This will put
daytime highs up to 10 degrees above normal. The ridge will
weaken Saturday into Sunday as a trough scrapes off the top layer
of the ridge, and cool temperatures a bit. The models have good
timing with the feature, but the models are not in sync as to the
strength of the next wave. The GFS shows WNW upper flow with
straight-line flow while the ECMWF has decent cyclonic flow.
Finally, the GEM splits the two other models with slight cyclonic
flow. We have trended slightly more toward the ECMWF and kept
some chances of light precipitation for Sat and into Sun. Either
way, this feature is progressive, and an amplified ridge
dominates again Monday with warmer temperatures. JClapp
&&
.Aviation...
Increasing high clouds as a weak trough approaches the west coast.
Light winds today except for some gusty NE winds down the Sierra
today before weakening tonight. Minor MVFR in BR over Nrn San
Joaquin Valley and Srn Sac Valley this morn. JClapp
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
344 PM MST MON JAN 6 2014
.SHORT TERM...UPPER JET HAS MOVED INTO THE CENTRAL PLAINS WITH
WEAKENING NORTHWEST FLOW ALOFT. WINDS HAVE DECREASED CONSIDERABLY
ACROSS THE MOUNTAINS...FOOTHILLS AND PARK COUNTY IN RESPONSE TO
WEAKENING GRADIENT...THOUGH STILL A BIT GUSTY. WESTERLY WINDS HAVE
SPREAD ONTO THE ADJACENT PLAINS OF NORTHERN JEFFERSON COUNTY...
ROUGHLY FROM GOLDEN TO THE BOULDER COUNTY LINE. THERE MAY STILL BE
SOME BLOWING SNOW IN OPEN AREAS. FLOW ALOFT BECOMES A BIT MORE
WESTERLY THIS EVENING AS WEAK UPPER TROUGH MOVES INTO THE NORTHERN
GREAT BASIN. MODELS SHOW A BIT OF A MOUNTAIN WAVE WITH CROSS
MOUNTAIN FLOW AROUND 30 KTS. WINDS TO REMAIN A BIT GUSTY ACROSS
THE MOUNTAINS AND FOOTHILLS WITH SOME GUSTS TO 45 MPH. LATEST HRRR
AND RAP ALSO SHOW WESTERLY WINDS PERSISTING ALONG THE BASE OF THE
FOOTHILLS THROUGH 06Z BEFORE DECREASING OVERNIGHT WITH SOME GUSTS
TO 30 MPH POSSIBLE. SOME POTENTIAL STILL EXISTS FOR BLOWING SNOW
IN OPEN AREAS...BUT LOOKS RATHER LOCALIZED SO WON`T INCLUDE IN
GRIDS FOR NOW. APPEARS BEST HANDLED WITH NOWCASTS. SOME INCREASE
IN MID LEVEL MOISTURE THROUGH THE EVENING AND INTO THE OVERNIGHT
HOURS. CHANCE FOR A WAVE CLOUD DEVELOPING IN AND NEAR THE
FOOTHILLS...AS SHOWN BY CIRA SYNTHETIC SATELLITE IMAGEY BECOMING
FAIRLY EXTENSIVE BETWEEN 09Z AND 15Z. OVERNIGHT LOWS TO MODERATE A
BIT...ESPECIALLY NEAR THE FOOTHILLS OF BOULDER AND JEFFERSON
COUNTY WHERE DOWNSLOPE WINDS WILL AID IN WARMING. LOW LYING AREAS
IN WELD COUNTY WILL STRUGGLE TO STAY ABOVE ZERO. ON TUESDAY...WEST
NORTHWEST FLOW ALOFT WILL PREVAIL. MODELS SHOW THE WEAK TROUGH
MOVING ACROSS WYOMING DURING THE AFTERNOON WITH SOME INCREASE IN
MID LEVEL QG ASCENT ACROSS THE MOUNTAINS LATE IN THE DAY. CROSS
SECTIONS INDICATE AN INCREASE IN IN MOISTURE ABOVE MOUNTAIN TOP.
SOME OROGRAPHICS IN PLACE ACROSS ZONE 31 TO KEEP A SLIGHT CHANCE
OF SNOW GOING. DID DELAY THE ONSET UNTIL 21Z WHEN OROGRAPHICS
BEGINS TO IMPROVE. OTHERWISE...A GRADUAL INCREASE IN CLOUDS. FLOW
ALOFT DECREASES SLIGHTLY THOUGH STILL A BIT OF A MOUNTAIN WAVE.
MAY STILL BE GUSTY OVER THE MOUNTAINS AND ALONG FOOTHILLS.
TEMPERATURES ACROSS PLAINS TO WARM INTO THE MIDDLE 40S MOST
AREAS...WITH UPPER 30S IN LOW LYING AREAS ACROSS WELD COUNTY.
.LONG TERM...SWIFT WEST-NORTHWEST FLOW WILL SEND A SERIES OF WEAK TO
MODERATE PERTABATIONS ACROSS COLORADO DURING THE UPCOMING WEEK.
MODELS GENERALLY AGREE IN PASSING THE NEXT WAVE ACROSS COLORADO
TUESDAY NIGHT/WEDNESDAY MORNING. MOUNTAINS SHOULD SCOOP UP MOST
OF THE MOISTURE CARRIED ALONG BY THIS SYSTEM. SCATTERED TO LIKELY
POPS ARE IN ORDER FOR THE NORTHERN AND CENTRAL MTNS DURING THIS
PERIOD. HOWEVER THE RATHER SHALLOW DEPTH OF THE MOISTURE SHOULD
KEEP ACCUMULATIONS ON THE LOW SIDE. QG VERT VELOCITY FIELDS
INDICATE ONLY WEAK SFC-500 ASCENT WITH ITS PASSAGE TUE NIGHT. ITS
POSSIBLE THE NORTHEAST CORNER OF THE CWFA COULD SEE A FEW
FLURRIES. OTHERWISE IT SHOULD REMAIN DRY EAST OF THE MTNS.
MEANWHILE TEMPERATURES WILL CONTINUE TO MODERATE WITH A LOW-LEVEL
DOWNSLOPE FLOW IN PLACE EAST OF THE FRONT RANGE. WEDNESDAY THROUGH
THURSDAY...FLOW ALOFT TRANSITIONS TO MORE OF A ZONAL COMPONENT
AND WEAK RIPPLES EMBEDDED IN THIS FLOW AND OROGRAPHICS SHOULD
CONTINUE TO PRODUCE PERIODS OF LIGHT SNOW THROUGH THE PERIOD.
AGAIN...ANY SNOW ACCUMULATION SHOULD BE MINOR AND LARGELY CONFINED
TO WEST FACING SLOPES AND TIMBERLINE AREAS.
NEXT...GFS AND ECMWF CONTINUE TO SHOW A LARGE OPEN WAVE TROUGH
FORMING OVER THE GREAT BASIN WEDNESDAY NIGHT AND THURSDAY AND
TRANSLATING EASTWARD ACROSS THE ROCKY MTN REGION THURSDAY NIGHT
AND FRIDAY. ENERGY AND MOISTURE ASSOCIATED WITH THIS WAVE APPEARS
SPLIT WITH PART PASSING OVER WYOMING AND THE OTHER PART OVER
SOUTHERN COLORADO AND NEW MEXICO. HOWEVER THE SOUTHERN BRANCH OF
ENERGY AND MOISTURE IS PROGGED TO LIFT NORTHEAST ACROSS OUR PART
OF THE STATE THURSDAY NIGHT/EARLY FRIDAY MORNING. THIS MAY BE THE
NEXT BEST CHANCE FOR SNOW ACCUMULATION IN THE HIGH COUNTRY THIS
WEEK. WHILE THE PLAINS WILL PROBABLY ESCAPE WITH ONLY A FEW
FLURRIES OR LIGHT SNOW SHOWERS UP AGAINST THE FOOTHILLS AND PALMER
DIVIDE. TEMPERATURES BOTH DAYS ARE EXPECTED TO REMAIN AT OR
SLIGHTLY ABOVE AVERAGE EVEN WITH ALL OF THE CLOUD COVER. BY
SATURDAY...MEDIUM RANGE MODELS SHOW THE TROUGH QUICKLY MOVING OUT
WHICH SETS THE STAGE FOR A WARMING AND GUSTY CHINOOK WIND ALONG
THE FRONT RANGE. SHOULD SEE A NICE REBOUND IN TEMPERATURES OVER
AND EAST OF THE FRONT RANGE THAT DAY UNDER CLEARING SKIES. HIGH
COUNTRY ALSO LOOKS DRY WITH AMPLE SUNSHINE. THEN ON SATURDAY NIGHT
AND SUNDAY...THE NEXT IN THE SERIES OF SYSTEMS ORIGINATING OVER
THE PACIFIC NORTHWEST RACES ACROSS WYOMING AND NORTHERN COLORADO.
LOOKS LIKE ANOTHER SHOT OF SNOW AND GUSTY WINDS FOR THE HIGH
COUNTRY AND GUSTY WINDS AND A SLIGHT CHANCE OF RAIN/SNOW FOR LOWER
ELEVATIONS. MONDAY LOOKS DRIER AND WARMER WITH UPPER RIDGE
BUILDING OVER THE INTERMOUNTAIN WEST.
&&
.AVIATION...NORTHWEST WINDS CURRENTLY SPREADING ACROSS KBJC AND
KDEN WITH SPEEDS AROUND 8 KTS. LIGHT SOUTHEAST WINDS CONTINUING AT
KAPA. LATEST MODELS STILL INDICATING WINDS TO BECOME SOUTHEAST AT
KDEN AROUND 00Z. WILL CONTINUE THIS TREND FOR THE UPCOMING
ISSUANCE. WINDS TO BE MORE WESTERLY AT KBJC WITH SOME GUSTS TO 20
KTS AFTER 06Z. SOME INCREASE IN MID AND HIGH LEVEL CLOUD WITH
POTENTIAL FOR A WAVE CLOUD IN AND NEAR THE FOOTHILLS AFTER 10Z.
CEILINGS TO REMAIN ABOVE 12000 FEET. WINDS TO WEAKEN BY 15Z AND
BECOME SOUTHERLY. MAY BE MORE SOUTHEAST AT KDEN AND KAPA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1013 AM MST MON JAN 6 2014
.UPDATE...
&&
.SHORT TERM...WIND CHILL ADVISORY ALLOWED TO EXPIRE FOR THE PLAINS
AS TEMPERATURES ARE SLOWLY WARMING. ADVISORY CRITERIA NO LONGER
BEING MET AS WINDS FAIRLY LIGHT. OTHERWISE...CURRENT FORECASTS
LOOK ON TRACK. UPPER JET CURRENTLY OVER REGION WITH FAIRLY STRONG
NORTHWEST FLOW ALOFT. SUBSIDENCE AND DOWNWARD MOTION ON BACK SIDE
OF JET STILL CREATING WINDY CONDITIONS ACROSS THE HIGH ELEVATIONS
AND ALONG THE FOOTHILLS AS WELL AS PORTIONS OF SOUTH PARK. THE
GUSTY WINDS MOST PRONOUNCED ALONG THE LEE OF THE MOSQUITO
RANGE...WITH CURRENT WINDS GUSTING TO 66 MPH AT KENOSHA PASS ALONG
HIGHWAY 285 BETWEEN JEFFERSON AND FAIRPLAY IN PARK COUNTY. THE
GUSTY WINDS MOST LIKELY PRODUCING SOME BLOWING SNOW WITH REDUCED
VISIBILITIES. JET WILL CONTINUE TO MOVE EAST DURING THE DAY WITH
FLOW ALOFT BECOMING WESTERLY. THOUGH GRADIENT EXPECTED TO
WEAKEN...MOUNTAIN WAVE WILL STILL PERSIST FOR MUCH OF THE
AFTERNOON. GUSTY WINDS TO CONTINUE ACROSS THE MOUNTAINS...
FOOTHILLS AND SOUTH PARK AS WELL AS THE NEARBY PLAINS. SPEEDS
SHOULD NOT BE AS STRONG AS CURRENTLY BEING OBSERVED. BLOWING SNOW
WILL STILL BE A POSSIBILITY IN OPEN AREAS. WILL LOWER MAX TEMPS A
BIT IN THE LOW LYING AREAS ALONG THE SOUTH PLATTE RIVER NORTH OF
DENVER AS TEMPERATURES STILL AT ZERO OR SLIGHTLY BELOW AND MAY
STRUGGLE TO REACH 20 DEGREES.
.AVIATION...CURRENT TAF TRENDS LOOK REASONABLE. FAIRLY STRONG
NORTHWEST FLOW ALOFT TO GRADUALLY WEAKEN THROUGH THE
DAY...BECOMING MORE WESTERLY. LATEST MODELS CONTINUE TO KEEP
SOUTHEAST WINDS AT KDEN AND KAPA WHILE REMAINING WESTERLY AT KBJC.
ENOUGH SHEAR IN PLACE TO KEEP LLWS GOING AT KDEN THROUGH 20Z.
&&
.PREV DISCUSSION... /ISSUED 329 AM MST MON JAN 6 2014/
SHORT TERM...STRONG UPPER LEVEL JET IS MOVING OVERHEAD AT THIS
TIME CREATING SOME LOCALIZED VERY WINDY CONDITIONS IN THE HIGH
ELEVATIONS AND PARTS OF SOUTH PARK IN THE LEE OF THE MOSQUITO
RANGE. THERE IS LIKELY SOME BLOWING SNOW IN THESE AREAS AS WELL.
AS THE JET PUSHES EASTWARD WITH THE UPPER RIDGE COMING OUR WAY
THESE VERY STRONG WINDS SHOULD SETTLE DOWN BUT IT WILL REMAIN
RELATIVELY WINDY UP HIGH THROUGH THE PERIOD. WITH THE FLOW ALOFT
BECOMING A BIT MORE WESTERLY MOUNTAIN WAVE ACTIVITY WILL BRING
GUSTY WINDS TO SOME FOOTHILL LOCATIONS AS WELL AS AREAS RIGHT UP
AGAINST THE FOOTHILLS LATER IN THE DAY. THE HRRR SEEMS TO HAVE A
DECENT GRASP ON THIS SITUATION. ANY SPOTS THAT SEE THE GUSTY WINDS
WILL ALSO BE PRONE TO BLOWING AND DRIFTING SNOW AND ASSOCIATED
LOWERED VISIBILITIES. THERE WILL BE A FEW SNOW SHOWERS OVER THE
HIGHER MOUNTAINS THIS MORNING ALONG WITH SOME PATCHY FOG OVER THE
PLAINS. ASIDE FROM THESE PHENOMENA WEATHER NIL. WILL LET THE WIND
CHILL ADVISORY GO AS IS...EXPIRING AT 0800 MST. HIGH TEMPERATURES
WILL REMAIN BELOW NORMAL TODAY BUT WILL PROBABLY BE SOME 15 TO 20
DEGREES ABOVE THOSE EXPERIENCED SUNDAY. MINIMA TONIGHT WILL ALSO
BE QUITE A BIT WARMER THAN WHAT IS OCCURRING PRESENTLY. PLENTY OF
SUNSHINE TODAY AND GENERALLY CLEAR SKIES TONIGHT ASIDE FROM THE
WAVE CLOUDS SHOWN IN THE CIRA SYNTHETIC SATELLITE IMAGERY. THESE
BECOME RATHER EXTENSIVE OVER THE FOOTHILLS BY 12Z TUESDAY.
LONG TERM...MODELS HAVE MODERATE WEST-NORTHWESTERLY FLOW ALOFT FOR
THE FORECAST AREA TUESDAY THROUGH WEDNESDAY NIGHT. A WEAK TROUGH
MOVES ACROSS IN THE FLOW TUESDAY AFTERNOON AND EVENING. THEN
ANOTHER WEAK ONE LATER ON WEDNESDAY. NOTHING SIGNIFICANT...PERHAPS
A SPOT OF SNOW FOR THE MOUNTAINS. THERE IS ASCENT PROGGED
ACCORDING TO THE QG VERTICAL VELOCITY FIELDS FOR THE CWA ON
TUESDAY...THEN DOWNWARD MOTION TUESDAY NIGHT. WEDNESDAY`S SYNOPTIC
SCALE ENERGY IS PRETTY BENIGN. SOME OF THE MODELS SHOW WEAK LOW
LEVEL UPSLOPE FOR THE PLAINS TUESDAY AFTERNOON AND EVENING.
WEDNESDAY`S WINDS LOOK PRETTY WEAK...WITH MAYBE SOME DOWNSLOPING
TO ENHANCE THE NORMAL DRAINAGE PATTERNS WEDNESDAY NIGHT. FOR
MOISTURE...MODELS SHOW QUITE A BIT IN THE MID AND UPPER LEVELS
FROM MIDDAY TUESDAY THROUGH WEDNEDAY AFTERNOON. THE MOISTURE IS
PRETTY DEEP OVER THE MOUNTAINS TUESDAY NIGHT WELL INTO WEDNESDAY.
THIS MORE SO ON THE GFS. MODELS HAVE LIMITED MEASURABLE SNOWFALL
OVER THE MOUNTAINS TUESDAY EVENING INTO WEDNESDAY EVENING
ACCORDING TO THE QPF FIELDS. FOR POPS...WILL KEEP IN OR GO WITH
20-50%S IN THE MOUNTAINS AND HIGH VALLEYS...SAVE PARK COUNTY
..FROM TUESDAY NIGHT THROUGH WEDNESDAY EVENING. WILL DECREASE
MOUNTAIN POPS WEDNESDAY NIGHT AFTER MIDNIGHT. NO POPS FOR THE
PLAINS OR FOOTHILLS. FOR TEMPERATURES...TUESDAY`S HIGHS ARE
PROGGED TO 6-11 C WARMER THAN TODAY`S. WEDNESDAY`S COOL DOWN A
BIT...SOME 2.0-3.5 C FROM TUESDAY`S. FOR THE LATER DAYS...
THURSDAY THROUGH SUNDAY...MODELS KEEP MORE OF THE SAME GOING. THEY
HAVE A WEAK UPPER TROUGH MOVE ACROSS THURSDAY MORNING...BUT A
STRONGER ONE ON FRIDAY...WHICH THE ECMWF IS A PERIOD QUICKER WITH.
THERE ARE STRONG NORTH TO NORTHWEST UPPER LEVEL WINDS BEHIND THE
TROUGH...AGAIN WHICH THE ECMWF IS EARLIER WITH. BY SUNDAY...BOTH
MODELS ARE SHOWING A MORE SIGNIFICANT UPPER TROUGH GETTING INTO
COLORADO. IT BEARS WATCHING. WILL HAVE "CHANCE" POPS IN THE
MOUNTAINS FRIDAY INTO FRIDAY NIGHT. WILL GO SOME LIMITED POPS FOR
ALL THE CWA ON SUNDAY. TEMPERATURES LOOK TO HOVER NEAR NORMALS
MUCH OF THE TIME.
AVIATION...THERE MAY BE SOME PATCHES OF FOG FLOATING ABOUT UNTIL
MID MORNING WHICH COULD CREATE LIFR CONDITIONS FOR A TIME. ASIDE
FROM THAT VFR CONDITIONS ARE EXPECTED THROUGH TONIGHT. WINDS WILL
BE GENERALLY LESS THAN 10 KNOTS AND FAVORING A SOUTHEASTERLY
DIRECTION BY AFTERNOON AT KDEN AND KAPA WHEREAS KBJC WILL BEGIN
COMING UNDER THE INFLUENCE OF MOUNTAIN WAVE/LEE TROUGH ACTIVITY
KEEPING THE WINDS OUT OF THE WEST. THEY COULD ALSO SEE SOME GUSTS
INTO THE 20S BY AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
329 AM MST MON JAN 6 2014
.SHORT TERM...STRONG UPPER LEVEL JET IS MOVING OVERHEAD AT THIS
TIME CREATING SOME LOCALIZED VERY WINDY CONDITIONS IN THE HIGH
ELEVATIONS AND PARTS OF SOUTH PARK IN THE LEE OF THE MOSQUITO
RANGE. THERE IS LIKELY SOME BLOWING SNOW IN THESE AREAS AS WELL.
AS THE JET PUSHES EASTWARD WITH THE UPPER RIDGE COMING OUR WAY
THESE VERY STRONG WINDS SHOULD SETTLE DOWN BUT IT WILL REMAIN
RELATIVELY WINDY UP HIGH THROUGH THE PERIOD. WITH THE FLOW ALOFT
BECOMING A BIT MORE WESTERLY MOUNTAIN WAVE ACTIVITY WILL BRING
GUSTY WINDS TO SOME FOOTHILL LOCATIONS AS WELL AS AREAS RIGHT UP
AGAINST THE FOOTHILLS LATER IN THE DAY. THE HRRR SEEMS TO HAVE A
DECENT GRASP ON THIS SITUATION. ANY SPOTS THAT SEE THE GUSTY WINDS
WILL ALSO BE PRONE TO BLOWING AND DRIFTING SNOW AND ASSOCIATED
LOWERED VISIBILITIES. THERE WILL BE A FEW SNOW SHOWERS OVER THE
HIGHER MOUNTAINS THIS MORNING ALONG WITH SOME PATCHY FOG OVER THE
PLAINS. ASIDE FROM THESE PHENOMENA WEATHER NIL. WILL LET THE WIND
CHILL ADVISORY GO AS IS...EXPIRING AT 0800 MST. HIGH TEMPERATURES
WILL REMAIN BELOW NORMAL TODAY BUT WILL PROBABLY BE SOME 15 TO 20
DEGREES ABOVE THOSE EXPERIENCED SUNDAY. MINIMA TONIGHT WILL ALSO
BE QUITE A BIT WARMER THAN WHAT IS OCCURRING PRESENTLY. PLENTY OF
SUNSHINE TODAY AND GENERALLY CLEAR SKIES TONIGHT ASIDE FROM THE
WAVE CLOUDS SHOWN IN THE CIRA SYNTHETIC SATELLITE IMAGERY. THESE
BECOME RATHER EXTENSIVE OVER THE FOOTHILLS BY 12Z TUESDAY.
.LONG TERM...MODELS HAVE MODERATE WEST-NORTHWESTERLY FLOW ALOFT FOR
THE FORECAST AREA TUESDAY THROUGH WEDNESDAY NIGHT. A WEAK TROUGH
MOVES ACROSS IN THE FLOW TUESDAY AFTERNOON AND EVENING. THEN
ANOTHER WEAK ONE LATER ON WEDNESDAY. NOTHING SIGNIFICANT...PERHAPS
A SPOT OF SNOW FOR THE MOUNTAINS. THERE IS ASCENT PROGGED
ACCORDING TO THE QG VERTICAL VELOCITY FIELDS FOR THE CWA ON
TUESDAY...THEN DOWNWARD MOTION TUESDAY NIGHT. WEDNESDAY`S SYNOPTIC
SCALE ENERGY IS PRETTY BENIGN. SOME OF THE MODELS SHOW WEAK LOW
LEVEL UPSLOPE FOR THE PLAINS TUESDAY AFTERNOON AND EVENING.
WEDNESDAY`S WINDS LOOK PRETTY WEAK...WITH MAYBE SOME DOWNSLOPING
TO ENHANCE THE NORMAL DRAINAGE PATTERNS WEDNESDAY NIGHT. FOR
MOISTURE...MODELS SHOW QUITE A BIT IN THE MID AND UPPER LEVELS
FROM MIDDAY TUESDAY THROUGH WEDNEDAY AFTERNOON. THE MOISTURE IS
PRETTY DEEP OVER THE MOUNTAINS TUESDAY NIGHT WELL INTO WEDNESDAY.
THIS MORE SO ON THE GFS. MODELS HAVE LIMITED MEASURABLE SNOWFALL
OVER THE MOUNTAINS TUESDAY EVENING INTO WEDNESDAY EVENING
ACCORDING TO THE QPF FIELDS. FOR POPS...WILL KEEP IN OR GO WITH
20-50%S IN THE MOUNTAINS AND HIGH VALLEYS...SAVE PARK COUNTY
...FROM TUESDAY NIGHT THROUGH WEDNESDAY EVENING. WILL DECREASE
MOUNTAIN POPS WEDNESDAY NIGHT AFTER MIDNIGHT. NO POPS FOR THE
PLAINS OR FOOTHILLS. FOR TEMPERATURES...TUESDAY`S HIGHS ARE
PROGGED TO 6-11 C WARMER THAN TODAY`S. WEDNESDAY`S COOL DOWN A
BIT...SOME 2.0-3.5 C FROM TUESDAY`S. FOR THE LATER DAYS...
THURSDAY THROUGH SUNDAY...MODELS KEEP MORE OF THE SAME GOING. THEY
HAVE A WEAK UPPER TROUGH MOVE ACROSS THURSDAY MORNING...BUT A
STRONGER ONE ON FRIDAY...WHICH THE ECMWF IS A PERIOD QUICKER WITH.
THERE ARE STRONG NORTH TO NORTHWEST UPPER LEVEL WINDS BEHIND THE
TROUGH...AGAIN WHICH THE ECMWF IS EARLIER WITH. BY SUNDAY...BOTH
MODELS ARE SHOWING A MORE SIGNIFICANT UPPER TROUGH GETTING INTO
COLORADO. IT BEARS WATCHING. WILL HAVE "CHANCE" POPS IN THE
MOUNTAINS FRIDAY INTO FRIDAY NIGHT. WILL GO SOME LIMITED POPS FOR
ALL THE CWA ON SUNDAY. TEMPERATURES LOOK TO HOVER NEAR NORMALS
MUCH OF THE TIME.
&&
.AVIATION...THERE MAY BE SOME PATCHES OF FOG FLOATING ABOUT UNTIL
MID MORNING WHICH COULD CREATE LIFR CONDITIONS FOR A TIME. ASIDE
FROM THAT VFR CONDITIONS ARE EXPECTED THROUGH TONIGHT. WINDS WILL
BE GENERALLY LESS THAN 10 KNOTS AND FAVORING A SOUTHEASTERLY
DIRECTION BY AFTERNOON AT KDEN AND KAPA WHEREAS KBJC WILL BEGIN
COMING UNDER THE INFLUENCE OF MOUNTAIN WAVE/LEE TROUGH ACTIVITY
KEEPING THE WINDS OUT OF THE WEST. THEY COULD ALSO SEE SOME GUSTS
INTO THE 20S BY AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...WIND CHILL ADVISORY UNTIL 8 AM
MST THIS MORNING FOR COZ042- 044>046-048>051.
&&
$$
SHORT TERM...ET
LONG TERM....RJK
AVIATION...ET
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1244 PM EST MON JAN 6 2014
.SYNOPSIS...
MILD WEATHER ALONG WITH PERIODS OF RAIN SHOWERS AND AREAS FOG ARE
EXPECTED TODAY AHEAD OF A STRONG COLD FRONT. A SHOT OF ARCTIC AIR
ARRIVES TONIGHT AND CONTINUES INTO WED BEHIND THE FRONT. MILDER
WEATHER RETURNS FRI INTO SAT WITH PERHAPS A PERIOD OF LIGHT
PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1 PM UPDATE...
ARCTIC COLD FRONT PRESENTLY ACROSS CENTRAL NEW ENGLAND.
OUT AHEAD...WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS...
CONTINUED SOUTHERLY FLOW AND AREAS OF FOG DOWN TO A QUARTER MILE
OR LESS. GUSTY WINDS UP TO 40 MPH POSSIBLE AS THE COMBINATION OF
WARMER TEMPERATURES AND HEAVIER RAIN ALLOW FOR THE MIX-DOWN OF
MOMENTUM TO THE SURFACE. BELIEVE THERE IS NO LONGER A THREAT FOR
THUNDER.
BEHIND...TEMPERATURES DROPPING QUICKLY TO WHICH MODELS ARE HAVING
SOMEWHAT OF A DIFFICULT TIME CATCHING UP ON. BEST GUIDANCE IS ON
THE HRRR THOUGH ITS DELAY DOES NOT CAPTURE THE PRESENT COLD
TEMPERATURES AND SNOW OVER ALBANY. IT IS LIKELY THE FORECAST DOES
NOT MERIT THE OUTCOME. RATHER IT BEARS WATCHING THE SLUG OF
PRECIPITATION OVERSPREADING WESTERN NEW ENGLAND OVERSPREADING THE
COLDER AIR SLIDING IN UNDERNEATH. ALREADY REPORTS OF SNOW OVER THE
BERKSHIRES HAS BEEN GATHERED AND AS THE SYSTEM LIFTS OUT IT IS
LIKELY WE WILL SEE SOME SNOW ON THE BACKSIDE FOR WESTERN AND
CENTRAL PORTIONS OF NEW ENGLAND. WILL DO THE BEST TO MODIFY THE
FORECAST TO ACCOUNT FOR TRENDS. WESTERLY FLOW IMMEDIATELY BEHIND
THE FRONT GUSTY UP TO AROUND 30 TO 40 MPH. MID-LEVEL CLOUDS
LINGERING WITH BOUNDARY LAYER MIXING UP TO H8 OF RESIDUAL
MOISTURE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
A SHOT OF ARCTIC AIR WILL BE WORKING INTO THE REGION TONIGHT. WHILE
IT CERTAINLY WILL BECOME VERY COLD...WE WON/T BE DEALING WITH THE
EXTREME BITTERLY COLD AIR AFFECTING THE MIDWEST. THIS SHOT OF
ARCTIC AIR WILL ATTACK US FROM THE WEST AND SOUTHWEST...WHICH IS
NOT A CLASSIC TRAJECTORY FOR SOUTHERN NEW ENGLAND. ITS MOST POTENT
FOR OUR REGION WHEN IT COMES FROM THE NORTH AND NORTHWEST.
NONETHELESS...IT WILL BE QUITE COLD AND WINDY TONIGHT. LOW TEMPS
BY DAYBREAK WILL BE WELL DOWN INTO THE TEENS IN MOST LOCATIONS AND
IT WILL BE BREEZY TO WINDY. THIS WILL RESULT IN WIND CHILL VALUES
BETWEEN 0 AND 10 BELOW BY DAYBREAK!
AS FOR PRECIP CHANCES...THE SHOT OF ARCTIC AIR WILL BE ACCOMPANIED
BY A STRONG UPPER LEVEL SHORTWAVE. THERE SHOULD BE ENOUGH FORCING
WITH THE UPPER LEVEL TROUGH TO GENERATE A FEW BRIEF SNOW SHOWERS
AND PERHAPS A HEAVIER SQUALL OR TWO. CAN/T RULE OUT A FEW
NEIGHBORHOODS RECEIVING A COATING TO 1 INCH OF SNOW...WHILE OTHER
AREAS DO NOT SEE ANYTHING.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...
* ANOTHER ROUND OF ARCTIC AIR AND HIGH PRESSURE TUESDAY INTO WED
* OCEAN EFFECT SNOW SHOWERS FOR THE ISLAND AND CAPE ON TUESDAY
* FLURRIES/SNOW SHOWERS POSSIBLE THURSDAY INTO FRIDAY
* WARMING TREND FOR NEXT WEEKEND
CONFIDENCE LEVEL/MODEL PREFERENCE...
HIGH CONFIDENCE IN STRONG ARCTIC AIR INTRUDING INTO THE REGION
TUESDAY INTO WEDNESDAY AS WELL AS OCEAN EFFECT SNOW SHOWERS FOR
THE WATERS. MODERATE CONFIDENCE ON AN OVERRUNING SYSTEM
THURSDAY/FRIDAY....UNCERTAIN ON TIMING AND PTYPE. RISING HEIGHTS
WILL LEAD TO A WARMING TREND FOR THE WEEKEND...MODERATE
CONFIDENCE. OTHERWISE LOW CONFIDENCE ON POSSIBLE SYSTEMS FOR THE
WEEKEND INTO NEXT WEEK AS THERE IS A LOT OF MODEL VARIABILITY.
OVERALL....
00Z MODEL GUIDANCE IS IN GOOD AGREEMENT IN ANOMALOUS TROUGH OVER
THE REGION ON TUESDAY AND PUSH INTO A MORE ZONAL FLOW BY
WED/THURSDAY. MID-ATLANTIC HIGH PRESSURE WILL BEGIN TO BUILD
WITHIN THE ZONAL FLOW...WITH THE EC SHOWING A MUCH STRONGER HIGH
THAN THE GFS. MODELS CONTINUE TO SHOW A WEAK RIPPLE IN THE
NORTHERN STREAM THAT WILL PUSH THE HIGH OFFSHORE LATE THURSDAY AND
ALLOW FOR A WEAK DISTURBANCE ON FRIDAY WITH THE EC SLIGHTLY SLOWER
THEN THE GFS. HOWEVER BOTH MODELS INDICATE A BUILDING RIDGE FOR
THE WEEKEND AHEAD OF SEVERAL SYSTEMS BY EARLY NEXT WEEK...STILL A
LOT OF TIMING DIFFERENCES AMONGST THE MODELS AND ENSEMBLES.
DETAILS...
TUESDAY INTO WEDNESDAY NIGHT...
ANOMALOUS TROUGH WITH SEVERAL EMBEDDED WAVES WILL CONTINUE TO
REMAIN OVER THE REGION TUESDAY INTO WEDNESDAY. THIS WILL KEEP THE
STRONG ARCTIC AIR IN SOUTHERN NEW ENGLAND RESULTING IN HIGH TEMPS
IN THE TEENS AND TWENTIES. ONE OF THESE WAVES WILL MOVE THROUGH
DURING THE DAY ON TUESDAY ALLOWING FOR POSSIBLE 30-40KTS AT 850MB
TO MIX DOWN AND CREATE BLUSTERY CONDITIONS. THERE IS A
POSSIBILITY THAT A WIND ADV MAY BE NEEDED ACROSS THE ISLANDS AS
THIS STRONG ARCTIC AIR WILL ALLOW FOR GOOD MIXING ALOFT...ALMOST
ABOVE 800MB. BECAUSE OF THE STRONG WINDS...COMBINED WITH ARCTIC
AIR APPEARS THAT WIND CHILL ADVISORIES MAY BE NEEDED ESP FOR
WESTERN/CENTRAL MASS ON TUESDAY NIGHT. DUE TO STRONG WESTERLY FLOW
ON TUESDAY...THERE IS AN INCREASING POSSIBILITY THAT A BAND OR TWO
FROM THE LES EVENT COULD MAKE ITS WAY INTO THE BERKS AND PERHAPS
INTO THE CENTRAL HILLS. INCREASED POPS FOR TUESDAY MORNING AND
MENTIONED ISOLATED SNOW SHOWERS...BUT IT WILL ALL BE DEPENDENT ON
WHERE EXACTLY THE BAND SETS UP AND HOW STRONG THE FLOW IS.
THE OTHER POTENTIAL IS THE POSSIBILITY OF OCEAN EFFECT SNOW SHOWERS
TO ACCUMULATE ACROSS ACK/BID AND PERHAPS THE OUTER CAPE. THIS VERY
COLD ARCTIC AIR ALOFT WILL MOVE OVER THE RELATIVELY WARM WATERS
AND CREATE A 850MB TEMPS SPREAD OF OVER 20C. MODELS ALSO INDICATE
LIC OVER OVER 600 J/KG AND VERY STEEP LAPSE RATES. DEPENDING ON
THE WIND DIRECTIONS ACK AND SOUTHERN SHORE OF RI MAY SEE
ACCUMULATING SNOW FALL. RI CHANCE IS IF A LONG ISLAND SOUND BAND
SETS UP. THE BEST CHANCE FOR THIS TO OCCUR IS WITH A MORE SW
FLOW...BUT IF THE 850MB TO SURFACE FLOW IS MORE WEST THEN
EXPECTED...PERHAPS A DUSTING IS MORE LIKELY. RIGHT NOW APPEARS
THAT A COATING TO LESS THAN AN INCH IS POSSIBLE...HOWEVER IF THE
FLOW BACKS AT ALL THEN 1-2 INCHES MAY OCCUR DEPENDING ON WHERE THE
BANDS SET UP.
THURSDAY AND FRIDAY...
HIGH PRESSURE WILL INTRUDE INTO THE REGION LATE WEDNESDAY INTO
THURSDAY RESULTING IN A WARMUP/CLOSER TO AVERAGE FOR THE REGION.
GFS AND EC DEVELOP A WEAK SYSTEM OVER THE MIDWEST LATE THURSDAY
INTO FRIDAY. APPEARS THAT THERE IS SOME OVERRUNING OF PRECIP AND
WITH THE SW FLOW OVER THE HIGH PRESSURE...COULD SEE SOME SNOW
SHOWERS AS IT WILL TAKE SOME TIME FOR THE WARM AIR TO PUSH THIS
COLD AIR OUT OF THE REGION. STILL A LOT OF UNCERTAINTY WITH THIS
POTENTIAL AS THE GFS WARMS UP VERY QUICKLY ON FRIDAY BUT BRINGS A
GOOD SWATH OF PRECIP WHILE THE EC HAS LESS PRECIP AND WONT WARM UP
TIL LATE FRIDAY NIGHT. REGARDLESS HAVE INCREASING CONFIDENCE IN
NEAR AVG TEMPS AND PRECIP LATE THURSDAY INTO FRIDAY.
WEEKEND...
RIDGING ALOFT INDICATES A JANUARY THAW FOR THE REGION AS HIGH
TEMPS WILL REACH INTO THE 40S TO 50S. MODELS INDICATE THAT SEVERAL
UPPER LEVEL DISTURBANCES WILL APPROACH THE REGION LATE WEEKEND
INTO NEXT WEEK. A LOT OF UNCERTAINTY REGARDING EXACT TIMING AND
PTYPE. LOOKS AS IF WE WILL BE ON THE WARMER SIDES OF THESE
SYSTEMS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH MONDAY/...
18Z UPDATE...
IFR-VLIFR SOUP REMAINING MAINLY OVER E NEW ENGLAND TERMINALS FOR
THE NEXT HR OR TWO AS THE COLD FRONT PRESENTLY OVER CENTRAL NEW
ENGLAND SWINGS E. VSBYS DOWN TO A QUARTER MILE. LLWS AROUND 210 AT
60 KTS AT 2 KFT WITH S WINDS AT THE SURFACE GUSTING UP TO 40 KTS.
WIDESPREAD RAIN +RA AT TIMES.
BEHIND THE FRONT...IMMEDIATE IMPROVEMENT TO VFR. W WINDS GUSTING
UP TO 35 KTS. CIGS LIFTING. EXPECTING W WINDS TO CONTINUE THROUGH
THE ENTIRE FORECAST PERIOD...GUSTS UP TO 40 KTS AT TIMES...WITH
SCT- BKN LOW- END VFR MAINLY OVER THE INTERIOR...WITH SCT-BKN MVFR
CIGS ALONG THE SHORES AND DEFINITELY OVER PORTIONS OF THE CAPE AND
ISLANDS. WINDS DIMINISHING TOWARDS WEDNESDAY MORNING.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...MODERATE CONFIDENCE
WEDNESDAY THROUGH FRIDAY... VFR WEDNESDAY AND THURSDAY. AREAS OF
MVFR CIGS/VSBYS IN RAIN/SNOW SHOWERS THURSDAY NIGHT AND FRIDAY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR TERM /TODAY AND TONIGHT/...MODERATE TO HIGH CONFIDENCE.
TODAY...SOUTHERLY FLOW INCREASING THIS MORNING AS LOW LEVEL JET
INTENSIFIES AHEAD OF AN APPROACHING COLD FRONT. LONG SOUTHERLY
FETCH HAS ALREADY ALLOWED SEAS TO BUILD TO SCA LEVELS ACROSS THE
OPEN WATERS ALONG WITH 20 TO 25 KNOT WIND GUSTS. IN
ADDITION...AREAS OF FOG WILL BE LOCALLY DENSE AT TIMES AND CAN/T
RULE OUT A RUMBLE OR TWO OF THUNDER.
TONIGHT...STRONG COLD ADVECTION BEHIND THE FRONT WILL RESULT IN
WESTERLY WIND GUSTS INCREASING TO AROUND 35 KNOTS. GALE WARNINGS
ISSUED FOR ALL WATERS...ALTHOUGH SOME WATERS MAY NOT SEE WINDS
INCREASE TO GALE LEVELS UNTIL DAYBREAK TUE. IN ADDITION...WE HAVE
ISSUED A FREEZING SPRAY ADVISORY FOR MOST OPEN WATERS BEGINNING AT
10Z TUESDAY AND CONTINUING THROUGH WED MORNING. STRONG WINDS AND
VERY COLD AIR WILL LEAD TO AREAS OF MODERATE FREEZING SPRAY OVER
THIS TIME.
OUTLOOK...TUESDAY THROUGH FRIDAY...MODERATE CONFIDENCE.
TUESDAY...WEST GALES CONTINUING WITH WINDS REACHING 35-40 KNOTS.
STRONGEST WINDS WILL BE ON TUESDAY. SEAS WILL BUILD TO 6-12 FEET
ON THE EXPOSED WATERS. A GALE WARNING HAS BEEN ISSUED FOR ALL THE
WATERS. EXPECT MODERATE FREEZING SPRAY ACROSS THE WATERS.
WEDNESDAY THROUGH FRIDAY...RESIDUAL WEST WINDS AROUND 25 KNOTS
WEDNESDAY...DIMINISHING WEDNESDAY NIGHT. WINDS REMAIN BELOW 25
KNOTS THROUGH FRIDAY. LEFTOVER 5-7 FOOT SEAS WEDNESDAY SUBSIDE BY
EVENING AND REMAIN BELOW 5 FEET THURSDAY-FRIDAY. POSSIBLE REDUCED
VSBYS IN RAIN/SNOW SHOWERS THURSDAY NIGHT AND FRIDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...DENSE FOG ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MAZ005>007-013>021.
DENSE FOG ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MAZ022>024.
NH...DENSE FOG ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR NHZ012.
RI...DENSE FOG ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR RIZ005-
007.
MARINE...FREEZING SPRAY ADVISORY FROM 5 AM TUESDAY TO 1 PM EST
WEDNESDAY FOR ANZ231-232-235-237-250-251-254>256.
GALE WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST TUESDAY FOR
ANZ231>234.
GALE WARNING FROM 7 AM TO 6 PM EST TUESDAY FOR ANZ230-236.
GALE WARNING FROM 10 PM THIS EVENING TO 1 AM EST WEDNESDAY FOR
ANZ235-237-254>256.
GALE WARNING FROM MIDNIGHT TONIGHT TO 1 AM EST WEDNESDAY FOR
ANZ250-251.
&&
$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...SIPPRELL
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...DUNTEN/SIPPRELL
MARINE...FRANK/DUNTEN
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
935 PM EST TUE JAN 7 2014
.DISCUSSION...
A COLD ARCTIC AIR MASS WITH DEW POINTS IN THE TEENS AND 20S COVERS
THE FORECAST AREA THIS EVENING WITH TEMPERATURES ALREADY IN THE MID
TO UPPER 30S ACROSS THE NATURE COAST...UPPER 30S TO LOWER 40S OVER
CENTRAL INTERIOR ZONES...AND LOWER TO MID 40S SOUTH AND ALONG THE
IMMEDIATE GULF COAST. AS FOR THE REMAINDER OF TONIGHT A SHORT WAVE
TROUGH MOVING ACROSS THE NORTHERN GULF WILL HELP TO INCREASE HIGH
CLOUDS FROM THE BAY AREA NORTHWARD INTO THE NATURE COAST OVERNIGHT
WHILE LOWER STRATO-CU CLOUDS WILL INCREASE ACROSS SOUTHERN AREAS AS
MOISTURE INCREASES IN THESE LOCATIONS THROUGH WEDNESDAY MORNING.
THE INCREASING CLOUD COVER COMBINED WITH THE LOW LEVEL FLOW BECOMING
NORTHEASTERLY WILL MAKE FOR A TRICKY TEMPERATURE FORECAST FOR THE
REST OF TONIGHT. AS MENTIONED IN THE AFTERNOON DISCUSSION OVERNIGHT
LOW TEMPERATURES WILL LIKELY OCCUR AROUND MIDNIGHT WITH TEMPERATURES
THEN REMAINING STEADY OR ACTUALLY RISING SOME THROUGH EARLY MORNING
AS THE CLOUDS THICKEN ACROSS THE REGION. GIVEN CURRENT IR-SATELLITE
AND TEMPERATURE TRENDS STILL THINK THAT 2 PLUS HOURS OF SUB-FREEZING
TEMPERATURES WILL OCCUR ACROSS THE HARD FREEZE AND FREEZE WARNING
AREAS COVERING THE NATURE COAST COUNTIES PRIOR TO THE CLOUDS BECOMING
TOO THICK AND WILL MAINTAIN THESE WARNINGS OVERNIGHT. IN ADDITION
WITH WINDS REMAINING CLOSE TO 10 MPH COMBINED WITH THE FALLING TEMPS
LOW WIND CHILLS READINGS ARE LIKELY FROM PASCO COUNTY SOUTH TO LEE
COUNTY OVERNIGHT AND WILL MAINTAIN THE WIND CHILL ADVISORY FOR THESE
LOCATIONS AS WELL. OVERALL THE ONGOING FORECAST LOOKS IN GOOD SHAPE
BUT WILL SEND OUT AN EVENING UPDATE TO REMOVE HIGH SURF AND RIP
CURRENT ADVISORY HEADLINES WHICH EXPIRED EARLIER THIS EVENING. OTHER
THAN THIS NO OTHER GRID OR ZONE CHANGES EXPECTED AT THIS TIME.
&&
.AVIATION...
VFR INTO THE MORNING...WITH THE POSSIBILITY OF BORDERLINE MVFR
SNEAKING INTO THE SW FL TERMINALS ON WEDNESDAY. NORTHEASTERLY WINDS
WILL PREVAIL THROUGH THE PERIOD.
&&
.MARINE...
ROUGH BOATING CONDITIONS CONTINUE OVER THE OFFSHORE GULF WATERS THIS
EVENING WHERE NORTH NORTHEAST WINDS IN THE 15 TO 20 KNOT RANGE AND
SEAS OF 4 TO 6 FEET CONTINUE...WITH SLIGHTLY LOWER WIND AND SEAS
STATES NOTED CLOSER TO SHORE. WITH A 6 TO 8 MB GRADIENT EXPECTED TO
CONTINUE ACROSS THE WATERS OVERNIGHT EXPECT LITTLE CHANGE IN CURRENT
WIND AND SEA STATES WHICH IS SUPPORTED BY LOCAL HRRR AND 4KM WRF
MODEL DATA THUS WILL MAINTAIN CAUTIONARY HEADLINES FOR THE OFFSHORE
WATERS FOR THE REMAINDER OF THE NIGHT WITH WINDS CLOSE TO 15 KNOTS
NEAR SHORE DIMINISHING TO 10 TO 15 KNOTS TOWARD MORNING.
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...WIND CHILL ADVISORY UNTIL 7 AM EST WEDNESDAY FOR COASTAL
CHARLOTTE-COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL
MANATEE-COASTAL PASCO-COASTAL SARASOTA-DESOTO-HARDEE-
HIGHLANDS-INLAND CHARLOTTE-INLAND HILLSBOROUGH-INLAND
LEE-INLAND MANATEE-INLAND PASCO-INLAND SARASOTA-
PINELLAS-POLK.
HARD FREEZE WARNING UNTIL 7 AM EST WEDNESDAY FOR COASTAL
CITRUS-COASTAL LEVY-INLAND CITRUS-INLAND LEVY.
FREEZE WARNING UNTIL 7 AM EST WEDNESDAY FOR COASTAL
HERNANDO-COASTAL PASCO-INLAND HERNANDO-INLAND PASCO-
SUMTER.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...57/MCMICHAEL
AVIATION...02/GARCIA
UPPER AIR/DATA COLLECTION...WYNN
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
709 AM EST MON JAN 6 2014
.SYNOPSIS...
A POTENT COLD FRONT WILL CROSS THE REGION THIS MORNING. ARCTIC
HIGH PRESSURE WILL THEN BUILD IN WAKE OF THE FRONT AND LINGER
THROUGH THE MIDDLE OF THE WEEK. A COASTAL TROUGH WILL THEN DEVELOP
OFFSHORE LATE WEEK BEFORE ANOTHER COLD FRONT APPROACHES THE AREA LATE
WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AROUND 12Z...THE COLD FRONT INTO OUR WESTERN ZONES WITH 12-14 DEGREE
TEMP FALLS IN THE PAST HOUR AT SYLVANIA AND STATESBORO. ON AN EARLIER
UPDATE...WE INITIALIZED THE WIND ADVISORY WE HAD ISSUED PRIOR TO BE
IN EFFECT IMMEDIATELY SINCE GUSTS HAVE ALREADY TOPPED 30 KT AT
TIMES TRAILING THE FROPA.
THE STRONG COLD FRONT WILL SWEEP THROUGH THE AREA THIS MORNING
WITH ARCTIC HIGH PRESSURE BEGINNING TO USHER IN BEHIND. PRECIP
POTENTIAL WITH THE FRONTAL PASSAGE LOOKS RATHER LOW GIVEN THE FACT
THAT MODEL TIME SECTIONS SHOW THE MOISTURE SCOURING OUT BY SHORTLY
AFTER DAYBREAK. THERE WILL PROBABLY BE A POCKETS OF LIGHT RAIN
SHOWERS ACCOMPANYING THE FRONT...MOVING OFF THE COAST BY MID TO
LATE MORNING. WE HAVE 20-30 PERCENT POPS DROPPING OFF BY NOON.
CLEARING EXPECTED INLAND DURING THE AFTERNOON AS MUCH DRIER AIR
FILTERS IN. THE INTENSE UPPER JET SEGMENT CLOSE TO 200 KT AT 250
MB MOVING INTO GEORGIA AND THE UPSTATE CAROLINAS SHOULD PRODUCE
BAND OF HIGH CLOUDS THIS AFTERNOON AND EVENING...A BIT UNCERTAIN
OF THEIR OPACITY AT THIS TIME.
WINDY CONDITIONS DEVELOP BY MID MORNING IN THE WAKE OF THE FRONT.
LOW-LEVEL WINDS WILL RAPIDLY INCREASE WITH WIND SPEEDS ATOP THE
MIXED LAYER INCREASING TO 35 KT BY LATE AFTERNOON. THE GUSTY WNW
WINDS COMBINED WITH STRONG COLD ADVECTION HAVE PROMPTED THE
ISSUANCE OF A WIND ADVISORY FOR SE GEORGIA AND EXTREME SOUTHERN
SOUTH CAROLINA BORDERING THE SAVANNAH RIVER. RECENT RAP MODEL
OUTPUT INDICATE A NOSE OF ENHANCED 1000 MB GEOSTROPHIC FLOW ARCING
INTO OUR SOUTHERN ZONES LIKE A BLADE TODAY. STRONG DOWNHILL
MOMENTUM...RAPIDLY DRYING AND SINKING AIR POST FRONTAL WERE ENOUGH
OF A CONCERN TO ISSUE THE ADVISORY FOR PERIODS OF STRONG WIND
GUSTS AT OR SLIGHTLY ABOVE 40 MPH. IN THE CHARLESTON TRI-COUNTY
AREA THE GUSTS NOT QUITE AS STRONG AS SAVANNAH GIVEN THE OFFSHORE
PUSH AROUND THE SOUTHERN END OF THE MOUNTAINS SO WE HELD OFF.
TODAY/S SHIFT WILL MONITOR TRENDS FOR ANY POSSIBLE EXTENSION IN
EITHER SPACE OR TIME.
STRONG COLD ADVECTION CONTINUES INTO TONIGHT WITH A DOWN-RIGHT COLD
AIRMASS SETTLING OVER THE AREA. LOW TEMPS WILL BE IN THE MID TEENS
FAR INLAND WITH UPPER TEENS TO LOWER 20S ALL THE WAY TO THE COAST.
ALTHOUGH LOW-LEVEL WINDS DROP OFF CONSIDERABLY AFTER MIDNIGHT...
BREEZY WINDS PERSIST DUE TO THE STRONG COLD ADVECTION. WE ARE IN
LINE WITH NEIGHBORING OFFICES WITH THE ISSUANCE OF A WIND CHILL
ADVISORY FOR LATE TONIGHT INTO MID TUESDAY MORNING. IT IS STILL
POSSIBLE THAT OUR WIND CHILL FORECAST MAY BE JUST A TAD LOW GIVEN
UNCERTAINTIES OF ACTUAL WIND SPEEDS DURING THE HOURS AROUND
DAYBREAK TUESDAY. HOWEVER GIVEN THE ANOMALOUS AIR MASS...IMPACTS WITH
WIND/COLD OF THIS NATURE WERE TAKEN SERIOUSLY FOR THOSE EXPOSED TO
THESE ELEMENTS. WE WILL REISSUE A PNS ON THE COLD WEATHER EARLY
THIS MORNING.
LAKE WINDS...DANGEROUS BOATING CONDITIONS WILL LIKELY DEVELOP IN
THE WAKE OF STRONG COLD FRONT LATER TODAY AND ESPECIALLY AFTER
SUNSET INTO THE EVENING HOURS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
TUESDAY...A WIND CHILL ADVISORY WILL LIKELY BE ONGOING FOR ALL
AREAS THROUGH LATE MORNING WITH ZERO TO 5 DEGREE WIND CHILL VALUES
EVEN UP ALONG THE COAST AS A WEST/NORTHWEST WIND CONTINUES. WINDS
WILL THEN BEGIN TO RELAX WHILE TEMPS GRADUALLY WARM...PUTTING AN
END TO A WIND CHILL ADVISORY BY 11 AM. DESPITE AN IMPROVEMENT TO
TEMPS AND WINDS...ARCTIC HIGH PRESSURE WILL CONTINUE TO BUILD FROM
THE WEST AND NORTHWEST...BECOMING CENTERED OVER OR JUST NORTH OF
THE AREA BY TUESDAY NIGHT. THE PATTERN WILL FAVOR ONGOING STRONG
COLD AIR ADVECTION OVER SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA THROUGHOUT THE DAY WHILE THE AREA REMAINS ALONG THE
SOUTHERN PERIPHERY OF A LARGE MID LVL TROUGH SHIFTING OFF THE
EASTERN SEABOARD. AS A RESULT...HIGH TEMPS ON TUESDAY WILL BE SOME
OF THE COLDEST WE HAVE SEEN SO FAR THIS YEAR. EXPECT TEMPS TO PEAK
ONLY IN THE LOW/MID 30S INLAND TO MID/UPPER 30S ALONG THE COAST.
WEATHER CONDITIONS WILL REMAIN DRY WITH THE ARCTIC AIRMASS IN
PLACE.
OVERNIGHT LOWS WILL BE VERY COLD ONCE AGAIN...MAINLY DUE TO THE
POSITION OF THE ARCTIC HIGH AND STRONG RADIATIONAL COOLING UNDER
LIGHT/CALM WINDS. EXPECT LOW TEMPS IN THE MID/UPPER TEENS INLAND AND
MID/UPPER 20S ALONG THE COAST. WIND CHILL TEMPERATURES MAY REACH AS
LOW AS 15 TO 20 DEGREES.
WEDNESDAY AND THURSDAY...CONDITIONS WILL REMAIN DRY ON WEDNESDAY AS
THE CENTER OF VERY COLD/DRY HIGH PRESSURE SLOWLY SHIFTS OFF THE MID
ATLANTIC COAST. A COASTAL TROUGH WILL THEN BEGIN TO DEVELOP OFFSHORE
ALONG THE SOUTHERN EDGE OF THE SFC HIGH WEDNESDAY NIGHT AND
THURSDAY. THE PATTERN WILL RESULT IN A GRADUAL MODIFICATION OF TEMPS
AS MID LVL RIDGING OCCURS OVER THE SOUTHEASTERN UNITED STATES WHILE
SFC WINDS SHIFT FROM NORTHWEST TO NORTHEAST. HOWEVER...TEMPS MAY
STRUGGLE TO WARM SIGNIFICANTLY OVER INLAND AREAS WHERE SFC HIGH
PRESSURE EXTENDS SOUTHWEST FROM THE CENTER OF THE ARCTIC HIGH OFF THE
MID ATLANTIC COAST. AS A RESULT...WARMEST TEMPS SHOULD OCCUR NEAR
THE COAST IN SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA WHERE
ONSHORE FLOW DEVELOPS. EXPECT OVERALL HIGHS IN THE MID/UPPER 40S ON
WEDNESDAY...WITH OVERNIGHT LOWS IN THE LOW 30S INLAND TO UPPER
30S/LOWER 40S ALONG THE COAST. TEMPS SHOULD THEN WARM INTO THE
MID/UPPER 50S INLAND TO LOWER 60S ALONG THE COAST ON THURSDAY.
CHANCES OF PRECIP SHOULD ALSO INCREASE WITH ISENTROPIC ASCENT AND
THE STRENGTHENING OF THE COASTAL TROUGH JUST OFFSHORE ON THURSDAY.
HOWEVER...PRECIP ACTIVITY COULD HAVE A TOUGH TIME MAKING IT WELL
INLAND WHERE HIGH PRESSURE LINGERS. HAVE THEREFORE MAINTAINED SLIGHT
CHANCE POPS IN THE FORECAST AT THIS TIME.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A COASTAL TROUGH WILL CONTINUE TO STRENGTHEN ALONG THE SOUTHERN
PERIPHERY OF HIGH PRESSURE OFF THE MID ATLANTIC COAST THROUGH LATE
WEEK. THIS FEATURE ALONG WITH ISENTROPIC LIFT SHOULD SUPPORT A FEW
SHOWERS OVER THE AREA ON FRIDAY...BEFORE COVERAGE INCREASES ON
SATURDAY AS THE COASTAL TROUGH LIFTS NORTH WITH A WARMER AIR MASS
WELL AHEAD OF A COLD FRONT/SFC LOW APPROACHING FROM THE WEST. FORECAST
CONFIDENCE REMAINS VERY LOW WITH REGARDS TO THE TIMING AND STRENGTH
OF THE COLD FRONT/SFC LOW APPROACHING THE SOUTHEASTERN UNITED
STATES...BUT THE GENERAL CONSENSUS IS THAT TEMPS WILL WARM
CONSIDERABLY AND CHANCES OF PRECIP WILL INCREASE UNTIL THE FEATURE
SHIFTS OFFSHORE EARLY NEXT WEEK. HAVE THEREFORE MAINTAINED A 30-40
POP SCHEME SUNDAY...BEFORE GRADUALLY LOWERING POPS ON MONDAY.
OVERALL...HIGH TEMPS SHOULD REACH THE LOWER 60S ON FRIDAY...THEN
MID/UPPER 60S ON SATURDAY AND SUNDAY...BEFORE SLIGHTLY COOLING INTO
THE LOW/MID 60S ON MONDAY. OVERNIGHT LOWS SHOULD ALSO SHOW A WARMING
TREND INTO EARLY NEXT WEEK...WITH TEMPS STARTING IN THE UPPER 30S TO
MIDDLE 40S THURSDAY NIGHT...THEN UPPER 40S TO MIDDLE 50S THIS
WEEKEND AND EARLY NEXT WEEK.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
IFR CIGS AT THE TERMINALS OVERNIGHT HAD LIFTED TO MVFR RECENTLY
AND THE WINDOW FOR ADDITIONAL IFR CONDITIONS IS QUICKLY CLOSING
AS THE LEADING EDGE OF THE MUCH COOLER AIR IS APPROACHING. LIGHT
SHOWERS AROUND THE COASTAL CORRIDOR FROM 12Z-16Z...THEN VFR WITH
ALL CONCERNS REVOLVING AROUND WIND SPEEDS AND GUSTS INTO TONIGHT.
FREQUENT GUSTS 25-30 KT ARE LIKELY THROUGH THIS EVENING WITH SOME
GUSTS UP TO 35 KT POSSIBLE DURING THE STRONGEST PRES RISES LATER
THIS MORNING INTO THIS AFTERNOON. THE BEST CHANCES FOR GUSTS THIS
HIGH COULD BE AT KSAV WHERE A WIND ADVISORY IS IN EFFECT. WINDS
SHOULD DIMINISH TOWARD 08Z-12Z WITH THE COLDER AIR ARRIVING.
EXTENDED AVIATION OUTLOOK...GUSTY WINDS ARE POSSIBLE AT BOTH
TERMINALS EARLY TUESDAY. OTHERWISE...VFR CONDITIONS SHOULD PREVAIL
TUESDAY INTO THURSDAY. ANOTHER ROUND OF MVFR CIGS/VSBYS IS POSSIBLE
FRIDAY AND SATURDAY AS A COASTAL TROUGH LIFTS NORTH OVER THE AREA.
&&
.MARINE...
A SIGNIFICANT MARINE EVENT WILL UNFOLD TODAY AND TONIGHT ACROSS
ALL OF THE WATERS BEHIND A STRONG COLD FRONT. 35-40 KT BOUNDARY
LAYER WINDS COMBINED WITH VERY STRONG COLD ADVECTION MOVING OVER
THE WARMER ATLANTIC WATERS WILL RESULT IN GALE CONDITIONS
BEGINNING THIS MORNING SOUTH OF CHARLESTON AND CONTINUING THROUGH
MUCH OF TONIGHT. THE STRONGEST SURGE IN SURFACE WINDS WILL LIKELY
BE THIS EVENING INTO THE FIRST PART OF THE OVERNIGHT AS -6C TO -12C
TEMPS AT H925 PLOW OVER THE WATERS. THERE IS A LOT OF MESOSCALE
INFLUENCES AND NUANCES INVOLVED WITH A COASTAL WATERS FORECAST LIKE
THIS AND WE BEGIN TO TRY TO SHOW SOME OF THE DETAILS IN THE GRIDS
THIS MORNING. THE OVERALL BOTTOM LINE TO ANYONE WITH MARINE INTEREST
IS PREPARE FOR EXTREMELY NASTY CONDITIONS WITH THE ADDED CONCERN
OF WIND CHILLS IN THE 10-20 DEGREE RANGE.
TUESDAY THROUGH FRIDAY...SMALL CRAFT ADVISORIES WILL LIKELY BE
ONGOING FOR ALL WATERS EARLY TUESDAY BEFORE WINDS/SEAS STEADILY
IMPROVE AS STRONGER LOW LVL WINDS SHIFT NORTHEAST AND AWAY FROM THE
AREA BY TUESDAY AFTERNOON. AS A RESULT...SMALL CRAFT ADVISORIES
WILL LIKELY NOT BE NEEDED BY TUESDAY AFTERNOON FOR NEARSHORE WATERS
AND BY TUESDAY EVENING FOR OFFSHORE GEORGIA WATERS. WINDS/SEAS
COULD APPROACH SMALL CRAFT ADVISORY LEVELS OVER OUTER GEORGIA WATERS
WEDNESDAY NIGHT INTO THURSDAY AS A COASTAL TROUGH DEVELOPS
OFFSHORE...WITH WINDS GUSTING UP TO 20-25 KT AND SEAS BUILDING UP TO
6 FT. CONDITIONS SHOULD THEN REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS INTO EARLY WEEKEND AS THE COASTAL TROUGH BEGINS TO LIFT NORTH
WITH A FEW SHOWERS OVER THE WATERS.
&&
.TIDES/COASTAL FLOODING...
ANOTHER ROUND OF BLOW-OUT TIDES ARE LIKELY ON LOW TIDES TONIGHT WITH
THE PASSAGE OF AN ARCTIC COLD FRONT. STRONG OFFSHORE FLOW AROUND
LOW TIDE COULD RESULT IN VERY LOW WATER LEVELS. THE LOW TIDE AROUND
DAYBREAK ON TUESDAY LOOKS THE MOST SIGNIFICANT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR GAZ087-088-
099>101-114>119-137>141.
WIND CHILL ADVISORY FROM 1 AM TO 10 AM EST TUESDAY FOR GAZ087-
088-099>101-114>119-137>141.
SC...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR SCZ040-042-047-
048-051.
WIND CHILL ADVISORY FROM 1 AM TO 10 AM EST TUESDAY FOR SCZ040-
042>045-047>052.
LAKE WIND ADVISORY UNTIL NOON EST TUESDAY FOR SCZ045.
MARINE...GALE WARNING UNTIL 4 AM EST TUESDAY FOR AMZ330-350-352-354.
GALE WARNING UNTIL 6 AM EST TUESDAY FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
439 AM EST MON JAN 6 2014
.SYNOPSIS...
A POTENT COLD FRONT WILL CROSS THE REGION THIS MORNING. ARCTIC
HIGH PRESSURE WILL THEN BUILD IN WAKE OF THE FRONT AND LINGER
THROUGH THE MIDDLE OF THE WEEK. A COASTAL TROUGH WILL THEN DEVELOP
OFFSHORE LATE WEEK BEFORE ANOTHER COLD FRONT APPROACHES THE AREA LATE
WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...IT HAS BEEN A BUSY OVERNIGHT DEALING WITH THE EXTREMELY
TRANSIENT SEA FOG BRUSHING COASTAL ZONES AND MARINE WATERS AND THE
STRONG LOW LEVEL WARM AIR ADVECTION PATTERN AHEAD OF THE POWERHOUSE
ARCTIC COLD FRONT BLASTING THROUGH CENTRAL GEORGIA AND THE MOUNTAIN
CHAIN. LOW LEVEL WIND FIELDS ARE VEERING AND INCREASING STEADILY
WITH TIME AND VSBY ISSUES IMPROVING ALONG THE COAST. WE THINK BY
5 AM WE WILL BE LOWERING ALL FOG BASED ADVISORIES BASED ON VERY
RECENT TRENDS. TEMPS HAVE WARMED TO THE MID 60S ALONG THE COAST
AND WINDS WERE STARTING TO GUST...OBVIOUSLY THE HIGHS TEMPS FOR
TODAY OCCURRING NOW. THE FRONT JUST BLASTED THROUGH MACON GEORGIA
WITH GUSTS TO 35 KT...A HARBINGER OF THINGS TO COME FOR OUR AREA.
THE STRONG COLD FRONT WILL SWEEP THROUGH THE AREA THIS MORNING
WITH ARCTIC HIGH PRESSURE BEGINNING TO USHER IN BEHIND. PRECIP
POTENTIAL WITH THE FRONTAL PASSAGE LOOKS RATHER LOW GIVEN THE FACT
THAT MODEL TIME SECTIONS SHOW THE MOISTURE SCOURING OUT BY SHORTLY
AFTER DAYBREAK. THERE WILL PROBABLY BE A POCKETS OF LIGHT RAIN
SHOWERS ACCOMPANYING THE FRONT...MOVING OFF THE COAST BY MID TO
LATE MORNING. WE HAVE 20-30 PERCENT POPS DROPPING OFF BY NOON.
CLEARING EXPECTED INLAND DURING THE AFTERNOON AS MUCH DRIER AIR
FILTERS IN. THE INTENSE UPPER JET SEGMENT CLOSE TO 200 KT AT 250
MB MOVING INTO GEORGIA AND THE UPSTATE CAROLINAS SHOULD PRODUCE
BAND OF HIGH CLOUDS THIS AFTERNOON AND EVENING...A BIT UNCERTAIN
OF THEIR OPACITY AT THIS TIME.
WINDY CONDITIONS DEVELOP BY MID MORNING IN THE WAKE OF THE FRONT.
LOW-LEVEL WINDS WILL RAPIDLY INCREASE WITH WIND SPEEDS ATOP THE
MIXED LAYER INCREASING TO 35 KT BY LATE AFTERNOON. THE GUSTY WNW
WINDS COMBINED WITH STRONG COLD ADVECTION HAVE PROMPTED THE
ISSUANCE OF A WIND ADVISORY FOR SE GEORGIA AND EXTREME SOUTHERN
SOUTH CAROLINA BORDERING THE SAVANNAH RIVER. RECENT RAP MODEL
OUTPUT INDICATE A NOSE OF ENHANCED 1000 MB GEOSTROPHIC FLOW ARCING
INTO OUR SOUTHERN ZONES LIKE A BLADE TODAY. STRONG DOWNHILL
MOMENTUM...RAPIDLY DRYING AND SINKING AIR POST FRONTAL WERE ENOUGH
OF A CONCERN TO ISSUE THE ADVISORY FOR PERIODS OF STRONG WIND
GUSTS AT OR SLIGHTLY ABOVE 40 MPH. IN THE CHARLESTON TRI-COUNTY
AREA THE GUSTS NOT QUITE AS STRONG AS SAVANNAH GIVEN THE OFFSHORE
PUSH AROUND THE SOUTHERN END OF THE MOUNTAINS SO WE HELD OFF.
TODAY/S SHIFT WILL MONITOR TRENDS FOR ANY POSSIBLE EXTENSION IN
EITHER SPACE OR TIME.
STRONG COLD ADVECTION CONTINUES INTO TONIGHT WITH A DOWN-RIGHT COLD
AIRMASS SETTLING OVER THE AREA. LOW TEMPS WILL BE IN THE MID TEENS
FAR INLAND WITH UPPER TEENS TO LOWER 20S ALL THE WAY TO THE COAST.
ALTHOUGH LOW-LEVEL WINDS DROP OFF CONSIDERABLY AFTER MIDNIGHT...
BREEZY WINDS PERSIST DUE TO THE STRONG COLD ADVECTION. WE ARE IN
LINE WITH NEIGHBORING OFFICES WITH THE ISSUANCE OF A WIND CHILL
ADVISORY FOR LATE TONIGHT INTO MID TUESDAY MORNING. IT IS STILL
POSSIBLE THAT OUR WIND CHILL FORECAST MAY BE JUST A TAD LOW GIVEN
UNCERTAINTIES OF ACTUAL WIND SPEEDS DURING THE HOURS AROUND
DAYBREAK TUESDAY. HOWEVER GIVEN THE ANOMALOUS AIR MASS...IMPACTS WITH
WIND/COLD OF THIS NATURE WERE TAKEN SERIOUSLY FOR THOSE EXPOSED TO
THESE ELEMENTS. WE WILL REISSUE A PNS ON THE COLD WEATHER EARLY
THIS MORNING.
LAKE WINDS...DANGEROUS BOATING CONDITIONS WILL LIKELY DEVELOP IN
THE WAKE OF STRONG COLD FRONT LATER TODAY AND ESPECIALLY AFTER
SUNSET INTO THE EVENING HOURS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
TUESDAY...A WIND CHILL ADVISORY WILL LIKELY BE ONGOING FOR ALL
AREAS THROUGH LATE MORNING WITH ZERO TO 5 DEGREE WIND CHILL VALUES
EVEN UP ALONG THE COAST AS A WEST/NORTHWEST WIND CONTINUES. WINDS
WILL THEN BEGIN TO RELAX WHILE TEMPS GRADUALLY WARM...PUTTING AN
END TO A WIND CHILL ADVISORY BY 11 AM. DESPITE AN IMPROVEMENT TO
TEMPS AND WINDS...ARCTIC HIGH PRESSURE WILL CONTINUE TO BUILD FROM
THE WEST AND NORTHWEST...BECOMING CENTERED OVER OR JUST NORTH OF
THE AREA BY TUESDAY NIGHT. THE PATTERN WILL FAVOR ONGOING STRONG
COLD AIR ADVECTION OVER SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA THROUGHOUT THE DAY WHILE THE AREA REMAINS ALONG THE
SOUTHERN PERIPHERY OF A LARGE MID LVL TROUGH SHIFTING OFF THE
EASTERN SEABOARD. AS A RESULT...HIGH TEMPS ON TUESDAY WILL BE SOME
OF THE COLDEST WE HAVE SEEN SO FAR THIS YEAR. EXPECT TEMPS TO PEAK
ONLY IN THE LOW/MID 30S INLAND TO MID/UPPER 30S ALONG THE COAST.
WEATHER CONDITIONS WILL REMAIN DRY WITH THE ARCTIC AIRMASS IN
PLACE.
OVERNIGHT LOWS WILL BE VERY COLD ONCE AGAIN...MAINLY DUE TO THE
POSITION OF THE ARCTIC HIGH AND STRONG RADIATIONAL COOLING UNDER
LIGHT/CALM WINDS. EXPECT LOW TEMPS IN THE MID/UPPER TEENS INLAND AND
MID/UPPER 20S ALONG THE COAST. WIND CHILL TEMPERATURES MAY REACH AS
LOW AS 15 TO 20 DEGREES.
WEDNESDAY AND THURSDAY...CONDITIONS WILL REMAIN DRY ON WEDNESDAY AS
THE CENTER OF VERY COLD/DRY HIGH PRESSURE SLOWLY SHIFTS OFF THE MID
ATLANTIC COAST. A COASTAL TROUGH WILL THEN BEGIN TO DEVELOP OFFSHORE
ALONG THE SOUTHERN EDGE OF THE SFC HIGH WEDNESDAY NIGHT AND
THURSDAY. THE PATTERN WILL RESULT IN A GRADUAL MODIFICATION OF TEMPS
AS MID LVL RIDGING OCCURS OVER THE SOUTHEASTERN UNITED STATES WHILE
SFC WINDS SHIFT FROM NORTHWEST TO NORTHEAST. HOWEVER...TEMPS MAY
STRUGGLE TO WARM SIGNIFICANTLY OVER INLAND AREAS WHERE SFC HIGH
PRESSURE EXTENDS SOUTHWEST FROM THE CENTER OF THE ARCTIC HIGH OFF THE
MID ATLANTIC COAST. AS A RESULT...WARMEST TEMPS SHOULD OCCUR NEAR
THE COAST IN SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA WHERE
ONSHORE FLOW DEVELOPS. EXPECT OVERALL HIGHS IN THE MID/UPPER 40S ON
WEDNESDAY...WITH OVERNIGHT LOWS IN THE LOW 30S INLAND TO UPPER
30S/LOWER 40S ALONG THE COAST. TEMPS SHOULD THEN WARM INTO THE
MID/UPPER 50S INLAND TO LOWER 60S ALONG THE COAST ON THURSDAY.
CHANCES OF PRECIP SHOULD ALSO INCREASE WITH ISENTROPIC ASCENT AND
THE STRENGTHENING OF THE COASTAL TROUGH JUST OFFSHORE ON THURSDAY.
HOWEVER...PRECIP ACTIVITY COULD HAVE A TOUGH TIME MAKING IT WELL
INLAND WHERE HIGH PRESSURE LINGERS. HAVE THEREFORE MAINTAINED SLIGHT
CHANCE POPS IN THE FORECAST AT THIS TIME.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A COASTAL TROUGH WILL CONTINUE TO STRENGTHEN ALONG THE SOUTHERN
PERIPHERY OF HIGH PRESSURE OFF THE MID ATLANTIC COAST THROUGH LATE
WEEK. THIS FEATURE ALONG WITH ISENTROPIC LIFT SHOULD SUPPORT A FEW
SHOWERS OVER THE AREA ON FRIDAY...BEFORE COVERAGE INCREASES ON
SATURDAY AS THE COASTAL TROUGH LIFTS NORTH WITH A WARMER AIR MASS
WELL AHEAD OF A COLD FRONT/SFC LOW APPROACHING FROM THE WEST. FORECAST
CONFIDENCE REMAINS VERY LOW WITH REGARDS TO THE TIMING AND STRENGTH
OF THE COLD FRONT/SFC LOW APPROACHING THE SOUTHEASTERN UNITED
STATES...BUT THE GENERAL CONSENSUS IS THAT TEMPS WILL WARM
CONSIDERABLY AND CHANCES OF PRECIP WILL INCREASE UNTIL THE FEATURE
SHIFTS OFFSHORE EARLY NEXT WEEK. HAVE THEREFORE MAINTAINED A 30-40
POP SCHEME SUNDAY...BEFORE GRADUALLY LOWERING POPS ON MONDAY.
OVERALL...HIGH TEMPS SHOULD REACH THE LOWER 60S ON FRIDAY...THEN
MID/UPPER 60S ON SATURDAY AND SUNDAY...BEFORE SLIGHTLY COOLING INTO
THE LOW/MID 60S ON MONDAY. OVERNIGHT LOWS SHOULD ALSO SHOW A WARMING
TREND INTO EARLY NEXT WEEK...WITH TEMPS STARTING IN THE UPPER 30S TO
MIDDLE 40S THURSDAY NIGHT...THEN UPPER 40S TO MIDDLE 50S THIS
WEEKEND AND EARLY NEXT WEEK.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
TAFS AMENDED FOR HIGHER-END IFR CIGS AND INCREASING SW FLOW UNTIL
THE FRONTAL PASSAGE. STRONG GUSTY SURFACE WINDS WILL USHER IN AN
VERY COLD AIR MASS TODAY AND TONIGHT WITH VFR CONDITIONS AFTER THE
SHIFT TO WEST NORTHWEST WIND DIRECTIONS. FREQUENT GUSTS 25-30 KT
ARE LIKELY THROUGH THIS EVENING WITH SOME GUSTS UP TO 35 KT
POSSIBLE AT SOME POINT DURING THE STRONGEST PRES RISES LATER THIS
MORNING INTO THIS AFTERNOON.
EXTENDED AVIATION OUTLOOK...GUSTY WINDS ARE POSSIBLE AT BOTH
TERMINALS EARLY TUESDAY. OTHERWISE...VFR CONDITIONS SHOULD PREVAIL
TUESDAY INTO THURSDAY. ANOTHER ROUND OF MVFR CIGS/VSBYS IS POSSIBLE
FRIDAY AND SATURDAY AS A COASTAL TROUGH LIFTS NORTH OVER THE AREA.
&&
.MARINE...
A SIGNIFICANT MARINE EVENT WILL UNFOLD TODAY AND TONIGHT ACROSS
ALL OF THE WATERS BEHIND A STRONG COLD FRONT. 35-40 KT BOUNDARY
LAYER WINDS COMBINED WITH VERY STRONG COLD ADVECTION MOVING OVER
THE WARMER ATLANTIC WATERS WILL RESULT IN GALE CONDITIONS
BEGINNING THIS MORNING SOUTH OF CHARLESTON AND CONTINUING THROUGH
MUCH OF TONIGHT. THE STRONGEST SURGE IN SURFACE WINDS WILL LIKELY
BE THIS EVENING INTO THE FIRST PART OF THE OVERNIGHT AS -6C TO -12C
TEMPS AT H925 PLOW OVER THE WATERS. THERE IS A LOT OF MESOSCALE
INFLUENCES AND NUANCES INVOLVED WITH A COASTAL WATERS FORECAST LIKE
THIS AND WE BEGIN TO TRY TO SHOW SOME OF THE DETAILS IN THE GRIDS
THIS MORNING. THE OVERALL BOTTOM LINE TO ANYONE WITH MARINE INTEREST
IS PREPARE FOR EXTREMELY NASTY CONDITIONS WITH THE ADDED CONCERN
OF WIND CHILLS IN THE 10-20 DEGREE RANGE.
TUESDAY THROUGH FRIDAY...SMALL CRAFT ADVISORIES WILL LIKELY BE
ONGOING FOR ALL WATERS EARLY TUESDAY BEFORE WINDS/SEAS STEADILY
IMPROVE AS STRONGER LOW LVL WINDS SHIFT NORTHEAST AND AWAY FROM THE
AREA BY TUESDAY AFTERNOON. AS A RESULT...SMALL CRAFT ADVISORIES
WILL LIKELY NOT BE NEEDED BY TUESDAY AFTERNOON FOR NEARSHORE WATERS
AND BY TUESDAY EVENING FOR OFFSHORE GEORGIA WATERS. WINDS/SEAS
COULD APPROACH SMALL CRAFT ADVISORY LEVELS OVER OUTER GEORGIA WATERS
WEDNESDAY NIGHT INTO THURSDAY AS A COASTAL TROUGH DEVELOPS
OFFSHORE...WITH WINDS GUSTING UP TO 20-25 KT AND SEAS BUILDING UP TO
6 FT. CONDITIONS SHOULD THEN REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS INTO EARLY WEEKEND AS THE COASTAL TROUGH BEGINS TO LIFT NORTH
WITH A FEW SHOWERS OVER THE WATERS.
&&
.TIDES/COASTAL FLOODING...
ANOTHER ROUND OF BLOW-OUT TIDES ARE LIKELY ON LOW TIDES MONDAY INTO
TUESDAY WITH THE PASSAGE OF AN ARCTIC COLD FRONT. STRONG OFFSHORE
FLOW AROUND LOW TIDE COULD RESULT IN VERY LOW WATER LEVELS. THE LOW
TIDE AROUND DAYBREAK ON TUESDAY LOOKS THE MOST SIGNIFICANT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR GAZ087-088-099>101-114>119-137>141.
WIND CHILL ADVISORY FROM 1 AM TO 10 AM EST TUESDAY FOR GAZ087-
088-099>101-114>119-137>141.
DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
GAZ117-119-139-141.
SC...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR SCZ040-042-047-048-051.
WIND CHILL ADVISORY FROM 1 AM TO 10 AM EST TUESDAY FOR SCZ040-
042>045-047>052.
DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
SCZ048>051.
LAKE WIND ADVISORY UNTIL NOON EST TUESDAY FOR SCZ045.
MARINE...DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
AMZ330-350-352-354.
GALE WARNING UNTIL 4 AM EST TUESDAY FOR AMZ330-350-352-354.
GALE WARNING UNTIL 6 AM EST TUESDAY FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1140 PM EST SUN JAN 5 2014
.SYNOPSIS...
ISSUED AT 520 AM EST SUN JAN 5 2014
A STRONG SYSTEM WILL BRING HEAVY SNOW TO THE AREA TODAY AND INTO
THIS EVENING. AMOUNTS OF 8 TO 16 INCHES ARE POSSIBLE. A WINTER
STORM WARNING IS IN EFFECT THROUGH THIS EVENING. EXTREMELY COLD
ARCTIC AIR WILL MOVE IN BEHIND THE SYSTEM THROUGH EARLY NEXT WEEK
WITH WIND CHILLS OF AROUND 40 BELOW ZERO SUNDAY NIGHT INTO
TUESDAY. A WIND CHILL WARNING IS IN EFFECT FOR THIS PERIOD. LOW
TEMPERATURES TONIGHT WILL CRASH TO BETWEEN 5 BELOW ZERO AND 18
BELOW ZERO BY DAYBREAK MONDAY.
&&
.UPDATE...
ISSUED AT 810 PM EST SUN JAN 5 2014
UPSTREAM OBSERVATIONAL TRENDS WITHIN LL CAA WING AND ALG NRN
EXTENT OF INTENSE SFC RISE/FALL PRES COUPLET AND NR TERM RUC
GUIDANCE SPURNED EARLIER BLIZZARD UPGRADE OVR WRN AREAS. JUST NOW
SEEING SFC GUSTS OVR 30KTS IN WHITE COUNTY AND XPC THIS TO SPREAD
EWD THROUGH THIS EVENING. RUC PROGS CARRY 40KT SFC WIND MAX UP TO
THE SR 36 CORRIDOR BY 03Z...SR 331 BY 05Z AND SR 15 BY 06Z AND
LASTING FOR ABOUT 6 HOURS BFR ABATING.
THIS MAY AFFECT ERN AREAS AS WELL BUT WILL WATCH TRENDS ACRS WRN
HALF THIS EVENING. HWVR ITS LIKELY THAT AFT SUNRISE...LOCATIONS
SOUTH OF LK SHSN OVR NE IN/NW OH WILL MIX SIGLY AND YIELD CONTD
SIG BLOWING/DRIFTING.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 350 PM EST SUN JAN 5 2014
HEIGHT OF HISTORIC WINTER STORM NOW WELL UNDERWAY ACROSS THE REGION
AT PRESS TIME. CULMINATION OF FACTORS SUPPORTING WIDESPREAD
ACCUMULATIONS OF 10-16 INCHES. COUPLED UPPER LEVEL JET STREAKS
FAVORING EFFECTIVE DIVERGENCE ALOFT WITH SOUTHERN BRANCH
STRENGTHENING TO 170+ KTS OVERNIGHT AND SHOWING A GREAT DEAL OF
CYCLONIC CURVATURE. LOW TO MIDLEVEL FGEN/DEFORMATION RESPONSE IS
SUPERB AND THE TRACK OF THE SURFACE LOW IS NEARLY IDEAL FOR A LONG
DURATION OF HEAVY SNOW IN OUR CWA. WATER VAPOR LOOP SHOWS POLAR
VORTEX PHASING WITH POTENT SOUTHERN STREAM PV ANOMALY AND RAPIDLY
BECOMING NEGATIVELY TILTED. THIS IS NOT ONLY SUPPORTING RAPID
DEEPENING OF THE SURFACE CYCLONE BUT ALSO PULLING IT A BIT TO THE
LEFT AS PREVIOUSLY DISCUSSED. THIS HAS ALLOWED SURFACE TEMPERATURES
TO CLIMB TO AROUND 32F AND WITH WARMER PROFILES ALOFT...CAUSED SNOW
RATIOS TO BE ONLY AROUND 10:1 FOR OUR CENTRAL AND SOUTHEAST
COUNTIES. THIS HAS BEEN ONE POTENTIAL LIMITING FACTOR BUT HAS BEEN
MORE THAN MADE UP FOR WITH IMPRESSIVE QPF TOTALS. MOISTURE
CONVERGENCE IS EXCELLENT WITH 280K MIXING RATIOS APPROACHING 4 G/KG.
ELEVATED INSTABILITY ABOVE ROUGHLY 600MB IS ALSO AIDING HIGHLY
EFFICIENT UVM AND BANDS OF HEAVY SNOWFALL ARE CLEARLY EVIDENT ON
RADAR. SNOWFALL RATES HAVE EXCEEDED 2"/HR IN THESE BANDS. EXPECT
STATUS QUO TO CONTINUE FOR ANOTHER 4-6 HOURS AND WITH ACCUMULATIONS
ALREADY EXCEEDING 8 INCHES IN SOME SPOTS...A FEW STORM TOTALS IN
EXCESS OF 16 INCHES MAY BE POSSIBLE BY LATER TONIGHT. CYCLONE WILL
LIFT RAPIDLY NORTHEAST BY 03Z THOUGH AND EXPECT MOST OF THE SYNOPTIC
SNOW TO WIND DOWN SHORTLY THEREAFTER.
ONE OF THE BIGGEST QUESTIONS REGARDING THIS STORM HAS BEEN THE
POTENTIAL FOR BLIZZARD CONDITIONS. EXPLOSIVE CYCLOGENESIS NOW
UNDERWAY WILL LEAD TO A VERY STRONG ISALLOBARIC COMPONENT TO THE
WIND BY LATER THIS EVENING. COUPLED WITH A TIGHT GRADIENT AND
RELATIVELY DEEP MIXING HEIGHTS...THIS WILL LEAD TO A BRIEF PERIOD OF
30-35 MPH GUSTS WHILE NEW SNOW IS STILL FALLING THIS EVENING. THIS
WILL LEAD TO NEAR BLIZZARD CONDITIONS WITH WIDESPREAD BLOWING AND
DRIFTING SNOW. VISIBILITY REQUIREMENT OF LESS THAN A QUARTER MILE
FOR THREE CONSECUTIVE HOURS IS EXTREMELY TOUGH TO GET IN THIS PART
OF THE COUNTRY THOUGH AND ONLY ONE UPSTREAM STATION (KCMI) HAS
REPORTED SUCH A LOW VISIBILITY. AFTER FURTHER COLLABORATION WITH
NEIGHBORING OFFICES...DECIDED TO HOLD OFF ON A BLIZZARD WARNING
UNLESS NEW OBSERVATIONAL EVIDENCE SUGGESTS OTHERWISE THIS EVENING.
SIGNIFICANT IMPACTS WILL CONTINUE THROUGH THE OVERNIGHT AND INTO
TOMORROW. MODEST LAKE RESPONSE EXPECTED GIVEN STRONG INSTABILITY AND
LINGERING SYNOPTIC MOISTURE. WINDS WILL QUICKLY BACK TO A WESTERLY
DIRECTION THIS EVENING AND THE BULK OF THE ADDITIONAL ACCUMULATION
OVERNIGHT AND INTO TOMORROW WILL BE MAINLY CONFINED NORTH OF THE
TOLL ROAD. INCREASING DRY AIR ADVECTION AND LOW SNOW RATIOS WILL
LIMIT ADDITIONAL ACCUMULATIONS TO AROUND 2-4 INCHES. BIGGEST HAZARD
WILL BE THE DANGEROUSLY COLD TEMPERATURES/WIND CHILLS. STILL
EXPECTING LOWS TO PLUMMET INTO THE MID TEENS BELOW ZERO BY LATE
TONIGHT WITH NO DIURNAL RECOVERY TOMORROW IN THE FACE OF STRONG CAA.
WIND SPEEDS OF 20-30 MPH WILL GENERATE WIND CHILL TEMPERATURES OF
AROUND -40F. NO CHANGES TO WIND CHILL WARNING NECESSARY.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 350 PM EST SUN JAN 5 2014
HISTORIC/POTENTIALLY LIFE-THREATENING COLD WILL GIVE WAY TO
SIGNIFICANT WARMING BY END OF THE WEEK. ONLY MINOR CHANGES MADE
GIVEN ONGOING WINTER STORM.
PERIOD WILL START WITH THE MUCH ADVERTISED CORE OF ARCTIC AIR
OVERHEAD AS LOWS STILL ON TARGET TO DROP TO 15 TO 20 BELOW WITH WIND
CHILLS OF 30 TO 45 BELOW INTO MID MORNING TUESDAY. IN ADDITION
EXTREME INSTABILITY WILL BE ONGOING OVER THE LAKE AS DELTA T`S ALL
THE WAY TO 700 MB TOP OUT AROUND 30 C WITH INVERSION HGTS AROUND
8000 FT. LIGHT TO MODERATE SNOW SHOULD BE OCCURRING BUT GENERAL
WESTERLY FLOW WILL KEEP MOST SNOW CONFINED TO FAR SOUTHERN LOWER
MICHIGAN. HAVE INCREASED POPS INTO CAT RANGE ACROSS N BERRIEN COUNTY
IN MOST FAVORABLE AREA AND NUDGED UP ACCUMS A TOUCH. ONE MORE BITTER
COLD DAY IN STORE FOR TUESDAY ALTHOUGH SOME AREAS WILL BE A GOOD 5
TO 10 DEGREES WARMER THAN MONDAY. NEVERTHELESS..ONLY LOCATIONS
ALONG THE LAKE WILL SEE TEMPS CLIMB ABOVE ZERO. WINDS WILL STILL BE
IN THE 10 TO 20 MPH RANGE WILL RESULT IN WIDESPREAD DRIFTING...BUT
ACTUAL BLOWING SNOW/REDUCED VSBYS WILL PROBABLY BE ISOLATED. FOR NOW
WILL LEAVE OUT OF GRIDS FOR BOTH MONDAY NIGHT AND TUESDAY.
CENTER OF POLAR VORTEX WILL RETREAT NORTH TO EAST OF HUDSON BAY
ALLOWING HGTS TO INCREASE AND THE START OF A WARMUP WHICH LOOKS TO
LAST THROUGH THE LONG TERM PERIOD. THIS WILL BRING CHALLENGES OF ITS
OWN AS ACTIVE FLOW CONTINUES WITH SEVERAL WAVES MOVING IN FOR
CHANCES FOR SNOW OR EVENTUALLY A MIXED BAG. IN ADDITION TO PRECIP
CHANCES TEMPS SHOULD RISE TO ABOVE FREEZING FOR HIGHS FRI-SUN INTO
THE 30S. EURO GUIDANCE CONTINUES TO POINT TOWARDS HIGHS IN THE 40S
AND MEX NOW TRYING FOLLOW SUIT. WHILE NOT IMPOSSIBLE...AMOUNT OF
SNOWPACK ACROSS THE AREA WILL LIKELY LIMIT FULL
POTENTIAL...ESPECIALLY FRIDAY WITH BEST CHANCE FOR 40S POSSIBLY BY
SUNDAY. THE INCREASING TEMPS WILL CAUSE A RELEASE OF THE SNOWPACK
AND WILL RESULT IN RISING RIVER LEVELS AND INCREASED CONCERNS FOR
BOTH RIVER AND LOW LYING FLOODING. HAVE GENERALLY KEPT FORECAST AS
IS THROUGH THIS TIME FRAME WITH TIMING/TRACK OF EACH WAVE LIKELY TO
VARY OVER THE NEXT SEVERAL DAYS. FOR NOW WITH SO MANY OTHER DETAILS
IN THE HWO...WILL HOLD OFF ON MENTION IN HWO AS DURATION OF RELEASE
COULD BE OVER A LONG ENOUGH PERIOD TO KEEP RISKS MINIMIZED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1139 PM EST SUN JAN 5 2014
ARCTIC BNDRY DEMARCATING BACK EDGE OF SIG LK ENHANCEMENT EAST OF
KSBN TERMINAL NOW YET WILL IMPACT KFWA 05-06Z. OTRWS -SHSN WITHIN
ARCTIC WEDGE DECAYING RAPIDLY AND XPC ACCUMULATING SNOW OVR AFT 06Z.
HWVR INFLUX OF ARCTIC WEDGE AND PLUMMETING TEMPS WILL YIELD STRONG
GRADIENT WIND GUSTS TO AOA 35KTS AND SPURN SIG BLOWING AND DRIFTING
SNOW THROUGH REMAINDER OF THE OVERNIGHT AND PROBABLY MOST OF
TOMORROW.
WILL REACCESS MONDAY WINDS WITH LTR 12Z ISSUANCE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ006>009-017-
018-025>027-033-034.
WIND CHILL WARNING UNTIL 8 PM EST /7 PM CST/ TUESDAY FOR
INZ003>009-012>018-020-022>027-032>034.
BLIZZARD WARNING UNTIL 7 AM EST /6 AM CST/ MONDAY FOR INZ003>005-
012>016-020-022>024-032.
MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ079>081.
WIND CHILL WARNING UNTIL 8 PM EST TUESDAY FOR MIZ077>081.
BLIZZARD WARNING UNTIL 4 AM EST MONDAY FOR MIZ077-078.
OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
005-015-016-024-025.
WIND CHILL WARNING UNTIL 8 PM EST TUESDAY FOR OHZ001-002-004-005-
015-016-024-025.
LM...HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST TUESDAY FOR LMZ043-
046.
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LMZ043-046.
&&
$$
UPDATE...T
SYNOPSIS...LASHLEY
SHORT TERM...AGD
LONG TERM...FISHER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1046 PM CST Sun Jan 5 2014
.UPDATE...
ISSUED AT 1032 PM CST SUN JAN 5 2014
Updated for 06z aviation.
&&
.SHORT TERM...(This Evening through Monday)
ISSUED AT 323 PM CST SUN JAN 5 2014
Current radar Mosaic indicates temporary weakening of pcpn echoes
west of the MS river, however some enhancement is also indicated
over sern MO/swrn IL associated with the exit region of an upper
level jet.
Meanwhile, the nwrn half of the region is under very rapid cold
air advection behind a ewd-departing sfc low, and these very raw
conditions will rapidly sweep across the rest of the region during
the late afternoon. Flash freezing of water on roads is expected.
Dual Pol correlation coefficient from KVWX radar was clearly
showing the rain/snow line beginning to accelerate ewd. Any
intervals of freezing rain or sleet are expected to be even
briefer in duration than they have been up to now.
The HRRR model suggests that the aforementioned enhanced area of
snowfall over sern MO/swrn IL will fill in over most of the region
late this afternoon, except west of Poplar Bluff MO, where
snowfall will taper off rapidly to flurries by sunset.
After sunset, little measurable snowfall is forecast, but
lingering moisture in the new arctic air mass will probably
produce flurries across the entire region into part of the
overnight hours.
A secondary mid level shrtwv will produce clouds and may produce
more flurries during the day Mon. We will flirt with record lows
tonight and Mon night and will shatter minimum highs for Mon.
Dangerous wind chill readings early Mon morning will range from
-20 south to -30 north. The brisk breeze will slowly decrease during
the day. The sun will return Tue, along with "warmer" temps in the teens.
.LONG TERM...(Monday Night through Sunday)
ISSUED AT 323 PM CST SUN JAN 5 2014
Extended models are in general agreement but there are always issues
in the details.
Early Wednesday there is a broad trough over the eastern US with a
more zonal flow over the western US. By Thursday two main troughs
can be seen to our west. One over KS and OK with another off the NW
coast of the US. The first impulse is slow to get here as the
overall pattern changes to a trough in the west and more zonal flow
in the east. But we will have overrunning precipitation both
Wednesday and Thursday.
By 00Z Saturday, the GFS, GEM, and ECMWF want to carve out an upper
level low over the southwest US or Mexico. After that the speed and
intensity of the wave is in question as it moves toward us.
The initial precipitation type will be snow or freezing rain with the
GFS being the warmer model aloft and hence the chance of freezing
rain. Snowfall accumulations will be light but will have to be
monitored. Held off on any ice accumulation until the models have a
better handle on the situation. The good news is that by Friday warm
air has taken over the entire CWA and expect liquid precipitation
over the region through the weekend.
&&
.AVIATION...
ISSUED AT 1032 PM CST SUN JAN 5 2014
Latest ir satellite loop and sfc obs indicate clearing poised to
move into the area with some sct mid deck. This will give vfr conditions
after 6z. However the forecast sounding and time height x-sections
would indicate another low deck returning around sunrise Monday.
Gusty nw winds will persist through 00z Tuesday then lose the gust
after 00z Tuesday.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY until 9 AM CST Tuesday FOR ILZ084>094.
WIND CHILL WARNING until 9 AM CST Tuesday FOR ILZ075>078-080>083.
MO...WIND CHILL ADVISORY until 9 AM CST Tuesday FOR MOZ076-086-087-
100-107>112-114.
IN...WIND CHILL WARNING until 9 AM CST Tuesday FOR INZ081-082-085>088.
KY...WIND CHILL ADVISORY until 9 AM CST Tuesday FOR KYZ001>022.
&&
$$
UPDATE...KH
SHORT TERM...DB
LONG TERM...PS
AVIATION...KH
AREA FORECAST DISCUSSION
NWS CARIBOU ME
308 PM EST MON JAN 6 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL TRACK WEST OF MAINE THIS AFTERNOON. MUCH COLDER
AIR WILL SWEEP BACK INTO THE AREA BEHIND THIS SYSTEM TONIGHT AND REMAIN
INTO LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLDER TEMPERATURES, FOG AND RE-FREEZING OF THE STANDING WATER THE
MAIN CONCERN FOR TONIGHT. THIS HAS LED TO SOME HYDROLOGY CONCERNS
WHICH ARE ADDRESSED IN THE LAST PARAGRAPH.
STRONG COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT USHERING IN
ANOTHER ROUND OF ARCTIC AIR. WARMER AIR W/RAIN OUT AHEAD OF THE
FRONT WILL BEGIN TO PUSH E THIS EVENING W/TEMPERATURES FALLING
BACK IN WESTERN MAINE LATER THIS AFTERNOON AND THEN REACHING
EASTERN AND NE AREAS AFTER 00Z. RAIN WILL GO TO A PERIOD OF SNOW
BEFORE ENDING AND THIS WILL MAINLY BE ACROSS THE FAR NORTHERN AND
WESTERN AREAS. ANY SNOW ACCUMULATIONS WILL BE LESS THAN AN INCH.
THE LATEST RUN OF THE HRRR WAS DOING REMARKABLY WELL W/THE RAINFALL
AND TEMPERATURES AND FOLLOWED ITS TREND INTO THE NIGHTTIME HOURS.
PRECIP SHOULD END FOR THE ENTIRE CWA BY MIDNIGHT W/PARTIAL CLEARING
THAT COLD AIR PUSHING IN. THE TEMPERATURES WILL REALLY PLUMMET
AFTER MIDNIGHT AS THE ARCTIC TAKES HOLD. READINGS BY EARLY MORNING
ON TUESDAY WILL BE IN THE SINGLE NUMBERS ACROSS NORTHERN AREAS
W/SOME LOCATIONS AOB ZERO ESPECIALLY IN WESTERN AND NORTHWEST
AREAS. ACROSS THE CENTRAL HIGHLANDS AND DOWNEAST, READINGS ARE
EXPECTED TO BE IN THE LOWER TEENS.
THIS COLDER AIR WILL ALLOW FOR THE SETUP FOR A FLASH FREEZE OR A
RE-FREEZE OF ANY STANDING WATER OVERNIGHT. THIS WILL LEAD TO
SLIPPERY ROAD CONDITIONS IN SOME LOCATIONS. A SPECIAL WEATHER
STATEMENT WILL BE ISSUED TO ADDRESS THIS SITUATION.
FOG WILL BE A CONCERN INTO THE EVENING ESPECIALLY ACROSS DOWNEAST
AND THE COAST. VSBYS DOWN ON THE COAST HAVE BEEN AROUND 1/4 OF A
MILE OR LOWER AT TIMES AND RUNNING FROM 1/2 TO 1/4 OF A MILE IN
THE BANGOR AREA. DECIDED TO KEEP WIDESPREAD FOG IN THESE AREAS THROUGH
EARLY EVENING AND ONCE THE COLDER AIR BEGINS TO FILTER IN AND
WINDS TURN WNW, CONDITIONS WILL IMPROVE. FOG ACROSS NORTHERN MAINE
FOR A TIME THIS EVENING BUT IT WILL BE SHORT LIVED.
AS FOR THE WINDS, THE STRONG WINDS THAT OCCURRED EARLIER TODAY
HAVE SINCE ABATED AS THE STRONG LLVL JET(55 KTS) HAS PUSHED TO THE
EAST INTO NEW BRUNSWICK. THEREFORE, THE WIND HEADLINES HAVE BEEN DROPPED.
LASTLY, THERE HAS BEEN CONCERN W/SOME PONDING OF WATER ON AREA
ROADS DUE TO THE SNOWMELT AND RAIN W/SOME STORM DRAINS CLOGGING
LEADING TO MINOR STREET FLOODING. A SURGE UP THE PENOBSCOT RIVER
NEAR BANGOR HAS LED THE CITY OF BANGOR TO CLOSE THE KENDUSKEAG
PLAZA PARKING GARAGE. THE LATEST GAGE HEIGHT WAS JUST AT 11.0 FT
WHICH IS CLOSE TO ACTION STAGE. A FLOOD ADVISORY WAS ISSUED
EARLIER FOR THIS AREA TO ACCOUNT FOR THE PLAY IN THE SURGE AND
REMAINS UP THROUGH THIS EVENING.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
EXPECT STRONG COLD ADVECTION DURING THE DAY TUESDAY AS INTENSE
LOW PRESSURE OVER NORTHEAST CANADA IN CONJUNCTION WITH STRONG HIGH
PRESSURE OVER THE SOUTH GENERATES A STRONG FLOW FROM THE
NORTHWEST. EXPECT THIS PATTERN TO PERSIST INTO WEDNESDAY THEN
MODERATE AS HIGH PRESSURE BUILDS IN FROM THE WEST DURING THE DAY
THURSDAY THEN CRESTS OVER THE REGION THURSDAY NIGHT. FOR POPS AND
QPF WILL USE A BLEND OF THE NAM12 ...GFS40 ...SREF AND ECMWF. FOR
WINDS HAVE USED THE MOSG25. THE TEMPERATURE GRIDS GENERATED WITH
THE RAW BLEND DUE TO THE EXPECTED CHANGE IN AIRMASS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MILD AND RELATIVELY UNSETTLED LATE THIS WEEK INTO EARLY NEXT WEEK.
HIGH PRESSURE OVERHEAD THURSDAY NIGHT WILL SHIFT TO OUR EAST
FRIDAY INTO SATURDAY, AND WITH THIS WILL COME A WARMER SOUTHWEST
FLOW. THERE LOOKS TO BE A DECENT CHANCE OF PRECIPITATION SATURDAY
AND SATURDAY NIGHT. TEMPERATURES WILL BE WARM ENOUGH FOR MIXED
PRECIPITATION FOR MOST OF THE AREA. TEMPERATURES COOL OFF A BIT
BEHIND THE SYSTEM SUNDAY/SUNDAY NIGHT, BUT NOT EVEN CLOSE TO THE
ARCTIC CHILL WE HAVE BEEN SEEING. THIS LOOKS TO CONTINUE THROUGH
ALL OF NEXT WEEK...A WARMER WEATHER PATTERN WITH FAIRLY WEAK
SYSTEMS IN WHICH WE WILL BE DEALING WITH PRECIPITATION TYPE
CHALLENGES.
MODELS ARE IN FAIRLY GOOD AGREEMENT THURSDAY NIGHT INTO THE
WEEKEND. SOME SLIGHT TIMING ISSUES WITH THE WEEKEND SYSTEM, BUT
NOTHING MAJOR. TIMING OF SYSTEMS INTO EARLY NEXT WEEK BECOMES
SIGNIFICANTLY MORE DIFFICULT.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
NEAR TERM: IFR/LIFR ATTM ACROSS THE TERMINALS. CONDITIONS ARE EXPECTED
TO IMPROVE MVFR LATER THIS EVENING AND THEN VFR AFTER MIDNIGHT W/A
WNW WIND TAKING OVER AND COLDER AIR MOVING IN.
SHORT TERM: EXPECT VFR CONDITIONS TUESDAY THROUGH THURSDAY.
&&
.MARINE...
NEAR TERM: LOWERED THE GALE WARNING TO A SCA AS WINDS HAVE COME
DOWN BELOW GALE FORCE. CARRIED GUSTS TO 30 KTS THIS EVENING W/A
FEW GUSTS TO 35 KTS POSSIBLE. WINDS ARE EXPECTED TO COME BACK UP
ON TUESDAY W/THE NW WIND AND SURGE OF CAA OVER THE RELATIVELY
WARMER OCEAN WATERS. WHEN ABOVE THE GUIDANCE ON THE WAVE HEIGHTS
EARLY TONIGHT BY 1-2 FT. A 8-9 SECOND PERIOD SWELL IS THERE ADDING
TO THE WAVE HEIGHTS. WAVE HEIGHTS WILL START TO FALL BACK EARLY
TUESDAY MORNING AS THE WIND BECOMES OFFSHORE.
SHORT TERM: FOR WIND HAVE BLENDED THE NAM12 AND GFS40. FOR WAVES:
LONG FETCH FROM THE GULF OF MAINE SOUTHWARD WILL PERSIST UNTIL IT
IS BROKEN UP BY THE WIND SHIFT LATER TONIGHT. PRIMARY WAVE GROUP
TUESDAY WILL BE FROM THIS FETCH ...6-10 FEET/10-11 SECONDS. EXPECT
THIS LONG PERIOD WAVE GROUP TO PERSIST INTO THURSDAY DUE TO THE
LENGTH OF THE FETCH. WILL USE THE SWAN/NAM TO GENERATE WAVE GRIDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT/NORTON
SHORT TERM...MIGNONE
LONG TERM...FOISY
AVIATION...HEWITT/MIGNONE
MARINE...HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS GRAY ME
1254 AM EST MON JAN 6 2014
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTH ALONG A STALLED FRONTAL BOUNDARY
WELL TO THE WEST OF THE FORECAST AREA OVERNIGHT. LOW PRESSURE WILL
CONTINUE NORTH THROUGH WESTERN QUEBEC ON MONDAY AND WILL DRIVE A
STRONG COLD FRONT THROUGH THE REGION MONDAY AFTERNOON. A STRONG
WESTERLY FLOW WILL PREVAIL BEHIND THE FRONT MONDAY NIGHT THROUGH
TUESDAY. HIGH PRESSURE WILL BUILD IN FROM THE SOUTH WEDNESDAY
THROUGH THURSDAY. A WARM FRONT WILL LIFT NORTH INTO THE FORECAST
AREA THURSDAY NIGHT AND WILL PUSH NORTHEAST OF THE REGION ON
FRIDAY. A COLD FRONT WILL PUSH THROUGH THE REGION FROM THE WEST ON
SATURDAY WITH HIGH PRESSURE TO FOLLOW ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATED TO INPUT LATEST OBSERVED DATA. HAVE ADJUST POP UP FOR ALL
ZONES OVERNIGHT PER LATEST RADAR. HAVE ADJUSTED PRCP TYPE TO
ACCOUNT FOR AREAS THAT CLIMBED ABOVE FREEZING...THE MID COAST /EG
RKD IS 36/ AND NH COAST /PSM IS 33/ AND SOME DOWNSLOPE AREAS IN
NRN NH...LIKE HIE THAT IS 41 DEGREES AT MIDNIGHT WHILE BML IS 29.
HAVE ADJUSTED TEMPS THRU MONDAY PER LATEST OBS AND TRENDS.
OTRW -FZRA CONTINUES WITH SOME SN/PL NRN MOST ZONES FOR A WHILE
WITH ACCUMULATING ICE...NO MORE THAN A QUARTER OF AN INCH...SO
WILL CONT ALL ADVISORIES. FZRA CHANGES TO RA FROM S TO N AND
COAST TO INLAND AREAS AROUND DAYBREAK INTO MONDAY MORNING.
PREVIOUS DISCUSSIONS...
1030PM UPDATE...
FORECAST STILL ON TRACK WITH FREEZING RAIN NOW SPREADING INTO THE
AREA FROM THE WEST. SOME AREAS OF SLEET AND SNOW ALSO OCCURRING IN
NORTHERN AREAS... BUT THIS WILL TRANSITION TO FREEZING RAIN OVERNIGHT.
630PM UPDATE...
HAVE ADJUSTED THE FORECAST TO BETTER REFLECT TIMING OF
PRECIPITATION AS IT ENTERS THE AREA TONIGHT. THE HEAVIEST BATCH OF
PRECIPITATION IS MOVING THROUGH NEW YORK STATE LATE THIS AFTERNOON
AND WILL MOVE INTO NEW HAMPSHIRE AND NORTHWEST MAINE THIS EVENING.
STILL EXPECTING DAMMING TO BE DEEP ENOUGH TO ALLOW PRECIPITATION
TO FALL AS SNOW AND SLEET FOR A GOOD TIME PERIOD ACROSS MUCH OF
MAINE AND NORTHERN NEW HAMPSHIRE... WHILE WARM ADVECTION ALOFT
WILL BE SUFFICIENT FOR FREEZING RAIN ACROSS SOUTHERN NEW HAMPSHIRE
AND FAR SOUTHWEST MAINE. PRECIPITATION MAY BE LIGHTER AT THE COAST
AS PRECIPITATION HERE MAY BE DRIVEN MORE BY MOIST ADVECTION OFF
THE OCEAN. STILL EXPECTING TEMPERATURES TO WARM EARLY MONDAY
MORNING... CHANGING FREEZING RAIN TO RAIN. ONE POSSIBLE CONCERN IS
THAT WHILE PRECIPITATION MAY CHANGE TO RAIN WHEN AIR TEMPERATURES
RISE ABOVE FREEZING... GROUND TEMPERATURES WILL LIKELY STAY COLD
DUE TO WEEKS OF SUB FREEZING TEMPERATURES FOR MANY AREAS. THIS
COULD ALLOW RAIN TO CONTINUE TO FREEZE ON GROUND SURFACES LIKE
ROADS EVEN AFTER TEMPERATURES WARM ABOVE FREEZING.
WINTER WEATHER ADVISORIES HAVE BEEN CONVERTED TO FREEZING RAIN
ADVISORIES FOR SOUTHERN AREAS WHERE PRECIPITATION WILL BE ALMOST
ENTIRELY FREEZING RAIN. TIMING HAS ALSO BEEN EXTENDED TO ACCOUNT
FOR A POTENTIALLY SLOWER WARM UP OVERNIGHT AND MONDAY MORNING.
ORIGINAL DISCUSSION...
VERY INTERESTING SETUP WITH LOW PRESSURE PASSING WELL TO OUR WEST
OVERNIGHT. HOWEVER...AT THE SAME TIME...A WEAK AREA OF LOW
PRESSURE HAS ALREADY FORMED ALONG THE MID ATLANTIC COASTLINE. THIS
IS AHEAD OF AND TO THE NORTH OF ALL MODELED GUIDANCE AT THIS TIME.
EVEN THE MESO MODELS ARE HAVING A DIFFICULT TIME...AS THEY ARE
NOT CAPTURING THE PRECIPITATION OVER SOUTHERN NEW ENGLAND AT THE
MOMENT.
IN ANY CASE...PRECIPITATION WILL ENTER THE FORECAST AREA THIS
EVENING. HAVE LEANED TOWARDS A COLD SOLUTION...A TAD COOLER THAN
ALL AVAILABLE GUIDANCE. ATMOSPHERE STILL VERY COLD AND DRY...AND
THERE WILL BE PLENTY OF EVAPORATION COOLING AS EVIDENT ON 12Z GYX
SOUNDING.
THEREFORE...HAVE EXPANDED THE WINTER WEATHER ADVISORIES TO INCLUDE
THE COASTLINE. LATEST HRRR KEEPS TEMPERATURES BELOW FREEZING FOR
MUCH OF THE COAST THROUGH AT LEAST MIDNIGHT BEFORE THE WARM UP.
WARM UP MAY BE A TAD EARLIER AT PSM AND ALONG THE NH SEACOAST.
ENOUGH DRY AIR IN PLACE TO POSSIBLY HOLD FOR SEVERAL HOURS OF
SNOWFALL IN THE USUAL SUSPECT LOCATION OF THE FOOTHILLS. GFS
ACTUALLY PICKS UP ON THIS FEATURE.
USED A NON-DIURNAL CURVE FOR THE OVERNIGHT MINS.
HAVE SENT FORECAST SNOWFALL AND ICE MAPS. ICE WILL BE A SENSITIVE
ISSUE AS WE HAVE HAD REPORTS OF ICE STILL IN THE TREES FROM THE
ICE STORM PRIOR TO THE HOLIDAYS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM TUESDAY/...
STRONG COLD FRONT WILL CROSS THE REGION MONDAY AFTER A SIGNIFICANT
WARM UP DURING THE AFTERNOON. TEMPERATURES WILL GO FROM WELL IN THE
40S...TO A DEEP FREEZE OVER A SHORT PERIOD OF TIME. STRONGEST
WINDS WILL HOLD OFF UNTIL THE PASSAGE OF THE UPPER LEVEL TROUGH.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
MORE BITTERLY COLD ARCTIC AIR IS EXPECTED TUESDAY THRU WEDNESDAY
ON GUSTY WESTERLY WINDS WHICH WILL CREATE EXTREMELY COLD WIND
CHILLS. THE UPSLOPE WESTERLY FLOW UNDER THE UPPER LEVEL SYSTEM WILL
CREATE SCATTERED SNOW SHOWERS ACROSS THE NORTH AND MOUNTAIN ZONES.
FINALLY AS HIGH PRESSURE BUILDS IN FROM THE WEST AND THE AIR MASS
CONTINUES TO WARM WE SHOULD SEE TEMPERATURES CLIMB BACK TO MORE
NORMAL LEVELS ALONG WITH LIGHTER WINDS ON THURSDAY. LATE
THURSDAY NIGHT AND FRIDAY A WARM FRONT WITH WARM ADVECTION ALOFT
WILL MOVE ACROSS NORTHERN NEW ENGLAND CREATING SOME LIGHT SNOW
SHOWERS ON FRIDAY INTO FRIDAY EVENING. TEMPERATURES SHOULD REMAIN
COLD ENOUGH TO BE SNOW. HIGH PRESSURE AND A WARMER AIR MASS WILL
TAKE CONTROL FOR SATURDAY.
USED THE SUPERBLEND FOR TEMPERATURES AND POPS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH MONDAY NIGHT/...IFR/LIFR EXCEPT MVFR/VFR AT
HIE DUE TO STRONG DOWNSLOPING SE WINDS. FZRA MAIN CONCERN WITH RA
ALONG THE COAST AT PSM AND RKD AND DOWNSLOPE NRN NH AREAS LIKE
HIE. OTRW FZRA CHANGES TO RA EARLY TO MID MORNING HOURS ON MONDAY
AT CON...AUG AND LEB. ADDED LLWS TO TAFS FOR STRONG SSE FLOW THAT
BECOMES SSW. CONDITIONS IMPROVE MONDAY AFTERNOON AND EVENING AS A
COLD FNT MOVES TO THE EAST. -SHSN WILL PERSIST AT HIE AND LIKELY
TO STAY MVFR MONDAY NIGHT.
LONG TERM...
MVFR IN SCATTERED SNOW SHOWERS FOR MOUNTAIN AREAS TUESDAY. GUSTY
WEST WINDS THRU TUESDAY NIGHT AND INTO WEDNESDAY. MVFR CONDITIONS
POSSIBLE FRIDAY IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
SHORT TERM /OVERNIGHT THROUGH MONDAY NIGHT/...UPDATED TO INPUT
LATEST OBSERVED DATA. WILL CONT THE SCA FOR CASCO BAY AND GLW ALL
OTHER COASTAL WATER ZONES AS SOUTHERLY FLOW INCREASE AHEAD OF THE
APPROACHING COLD FRONT. WINDS SHIFT TO THE WEST BEHIND THE FNT AND
WILL STAY RATHER STRONG SO SCA/GLW MAY BE NEEDED MONDAY NGT AS
WELL. A FEW TWEAKS TO THE PREVIOUS FCST BUT NO SIGNIFICANT CHANGES
AT THIS TIME.
LONG TERM...
AN EXTENDED PERIOD OF FAIRLY STRONG WINDS AND ROUGH SEAS WITH AT
LEAST SCA CONDITIONS (AND POSSIBLY GALES OVER THE OPEN WATERS)
THRU TUESDAY NIGHT AND INTO WEDNESDAY. WINDS THEN SEAS SLOWLY EASE
UP LATE WEDNESDAY THRU THURSDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FREEZING RAIN ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MEZ018-023-024.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MEZ007>009-
013-014.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MEZ012-019>022-025>028.
NH...FREEZING RAIN ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
NHZ005>010-013-014.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NHZ001-002.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NHZ003-004.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR ANZ153.
GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR ANZ150>152-154.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
525 PM EST MON JAN 6 2014
.SYNOPSIS...
THE ARCTIC AIRMASS OVER THE UPPER OHIO VALLEY REGION WILL MODERATE
QUICKLY DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
EARLY EVE UPDATE WAS ISSUED TO DROP THE WINTER WEATHER ADVISORY
FOR THE RIDGE ZONES AS ADDITIONAL SNOW ACCUMULATION WL BE MINOR
AND AREAS OF BLOWING SNOW WL LIKELY CAUSE ONLY LOCALIZED ISSUES.
OTHERWISE...HAVE ADJUSTED POPS AND SFC WIND BASED ON THE LATEST
OBS...RADAR...AND DETERMINISTIC MDL TRENDS. HAVE DIMINISHED GUSTS
MAINLY OVR THE RIDGES AS PER LATEST RAP AND NAM MOMEMTUM TRANSFER
PROGNOSIS...AS INVERSION LVLS WL LIKELY PREVENT DEEP MIXING OF
HIGHER WIND VALUES.
IN GENL...SUB ZERO AIR WL CONT TO SLIDE OVR THE REGION AS THE EVE
PROGRESSES...HENCE MOST DETAIL CHANGES ARE COSMETIC AND WIND CHILL
WARNING CONTS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
DRY AND COLD CONDITIONS WL PREVAIL THROUGH THROUGH TUESDAY NGT AND
WIND CHILL WARNING WAS CONTD FOR NOW. ALTHOUGH DIMINISHING WIND
AND WARM ADVCTN MAY PREVENT ACTUAL CRITERIA FM BEING REACHED AFTR
DARK ON TUESDAY...NO POINT TO HEADLINE ALTERATION AT THIS TIME.
THAT WARM ADVECTION REGIME WL INTENSIFY AND RTN TEMPS TWD THE
SEASONAL AVGS AS A SHRTWV IS PROJECTED ACRS THE GREAT LAKES ON
WED...WHILE ANOTHER IS PROGGED OUT OF THE LOWER OHIO ON THURSDAY.
SNOW CHCS HAVE BEEN MAINTAINED FOR THOSE FEATURES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS REMAIN CONSISTENT IN BRINGING A SHORTWAVE TROUGH AT 500MB
ACROSS REGION THURSDAY NIGHT. UPPED POPS TO COINCIDE WITH THIS
FEATURE AND QUICKLY PUSH THE FOCUS OF THESE CHC POPS EAST...DRYING
BEHIND IT. NOT ALTERING THE TEMPERATURES MUCH THURS AND FRI
MORNING...SO A PRIMARILY SNOW PTYPE EVENT REMAINS THE THINKING.
SIGNIFICANT WARM UP PROGGED FOR THE WEEKEND AS RIDGING TAKES PLACE
BEHIND EXITING SHORTWAVE. 850MB TEMPS REBOUND FROM NEAR FREEZING TO
8 TO 10C SAT ON THE GFS. BUMPED UP TEMPERATURES A FEW DEGREES ACROSS
THE BOARD AS WE GO ABOVE AVERAGE FOR THIS TIME OF YEAR. A WELCOMED
CHANGE BY MOST FROM THE COLD OF THE LAST WEEK. ANOTHER QUICK MOVING
SYSTEM IS POISED TO MOVE THROUGH SAT...BUT ONLY MODEST CAA BEHIND IT
KEEPS OUR TEMPERATURES FROM FALLING OFF DRAMATICALLY. ANOTHER SYSTEM
APPROACHES FROM THE SOUTH TO START NEXT WORK WEEK...BUT CONSIDERABLE
TIMING AND STRUCTURE DIFFERENCES EXIST ON HOW TO HANDLE THE SOUTHERN
CUTOFF TRACKING ACROSS THE SOUTHEAST.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
ALTHOUGH GENERAL VFR WL RTN THIS EVENING AND CONT INTO TUESDAY...SFC
WIND WL RMN AN AVIATION CONCERN WITH GUSTS TO ARND 25 KT CONTG.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
THE NEXT CHANCE FOR RESTRICTIONS WL COME WITH CROSSING DISTURBANCES
ON WEDNESDAY AND THURSDAY.
&&
.CLIMATE...
A SUMMARY OF SIGNIFICANT COLD TEMPERATURE READINGS IS INCLUDED
BELOW...
CITY MON/TUE LAST DATE LAST DATE LAST DATE
RECORD(YEAR) BELOW -10 BELOW 0 HIGH BELOW 0
PITTSBURGH -5(1942)/-5(1884) 1/17/2009 1/22/2011 1/19/1994
MORGANTOWN -1(1988)/-4(1970) 1/21/1994 1/17/2009 1/19/1994
ZANESVILLE -3(1959)/-3(1968) 1/22/2011 1/24/2011 1/19/1994
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR MDZ001.
OH...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR WVZ001>004-
012-021>023-041.
&&
$$
15
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
303 PM EST MON JAN 6 2014
.SYNOPSIS...
ARCTIC AIR WILL TAKE RESIDENCE OVER THE AREA THROUGH MID-WEEK WITH
THE COLDEST TEMPERATURES IN SEVERAL YEARS BEING THE NORM.
MODERATING CONDITIONS ARE EXPECTED LATER THIS WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE ARCTIC BOUNDARY HAS CLEARED THE AREA BUT RATHER STEEP LAPSE
RATES REMAIN IN ITS WAKE. THIS HAS TWO BASIC RAMIFICATIONS TO OUR
WEATHER THROUGH THE NIGHT. FIRST...BECAUSE TEMPERATURES ARE STILL
FALLING RATHER RAPIDLY...MOISTURE IS BEING SCOURED OUT OF THE
COLUMN...WHICH HAS RESULTED IN FLURRIES DUE TO INSTABILITY IN THE
BOUNDARY LAYER. AS THE MOISTURE GETS ERADICATED OVERNIGHT...THESE
SHOULD WIND DOWN. SECOND...LOW LEVEL INSTABILITY COUPLED WITH 30+
KTS OF FLOW BELOW THE MIXING HEIGHTS SHOULD RESULT IN FAIRLY
BREEZY CONDITIONS WITH GUSTS TO AS HIGH AS 40 MPH IN THE RIDGES.
AS SUCH...AREAS OF BLOWING SNOW WILL CONTINUE TO BE
POSSIBLE...PARTICULARLY IN THE HIGHER TERRAIN. THE WINTER WEATHER
ADVISORIES WERE THUS KEPT ONLY FOR THE RIDGES AS BLOWING SNOW IS
MORE LIKELY TO BE PROBLEMATIC IN THOSE LOCATIONS.
ELSEWHERE...WINTER WEATHER ADVISORIES WERE BROUGHT DOWN DUE TO THE
END OF ACCUMULATING SNOW.
WINDS COMBINED WITH OVERNIGHT LOW TEMPERATURE EXPECTATIONS LOOK TO
BE LIFE THREATENING. GFS/NAM INITIALIZATIONS AND MODEL FIELDS
THROUGH THE NIGHT FAILED TO ADEQUATELY HANDLE THE MAGNITUDE OF THE
COLD AIR TO OUR WEST...AND WERE SUMMARILY DISMISSED FROM
CONSIDERATION FOR OUR OVERNIGHT LOWS. ECMWF AND RUC FIELDS LOOKED
A BIT BETTER...SO THE LOWS WERE CONSTRUCTED USING THE COLDER END
OF THE GUIDANCE SPECTRUM. THIS MEANS WIDESPREAD READINGS BELOW
-10F ARE EXPECTED AND RECORDS WILL LIKELY GO DOWN ACROSS THE BOARD
TONIGHT. WIND CHILLS WARNINGS WERE CONTINUED FOR -25 TO -45F
READINGS AS A RESULT OF THE TEMPERATURE/WIND COMBO. FRIES
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
DRY AND COLD CONDITIONS PREVAIL THROUGH MID-WEEK AS THE WIND CHILL
WARNING CONTINUES THROUGH WEDNESDAY MORNING. WHETHER WE MANTA IN
READINGS BELOW THE -25F CRITERIA IS DEBATABLE AFTER TUESDAY
EVENING...BUT ISSUING A WARNING FOLLOWED BY AN ADVISORY SEEMS
CONFUSING...SO ONE CONSISTENT PRODUCT WILL CONTINUE EVEN THOUGH
THE WIND CHILLS WILL NOT CONTINUE TO FALL BELOW CRITERIA.
SLOW WARM ADVECTION AND MODERATION STARTS ON WEDNESDAY. ISENTROPIC
ASCENT OVER THE COLD AIR MASS WILL BRING CHANCES OF SNOW
COINCIDING WITH WEAK SHORT WAVE PASSAGES CENTERED AROUND WEDNESDAY
EVENING AND POSSIBLY AGAIN BY LATE THURSDAY/THURSDAY NIGHT. BY
THAT JUNCTURE...TEMPERATURES SHOULD BE NEARING FREEZING...WHICH
WILL LIKELY MAKE IT FEEL DOWNRIGHT TROPICAL OUTSIDE. HOWEVER...THE
COLUMN SEEMS LIKELY TO SUPPORT MOSTLY SNOW THROUGHOUT THE SHORT
TERM PERIOD OF THE FORECAST. FRIES
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS REMAIN CONSISTENT IN BRINGING A SHORTWAVE TROUGH AT 500MB
ACROSS REGION THURSDAY NIGHT. UPPED POPS TO COINCIDE WITH THIS
FEATURE AND QUICKLY PUSH THE FOCUS OF THESE CHC POPS EAST...DRYING
BEHIND IT. NOT ALTERING THE TEMPERATURES MUCH THURS AND FRI
MORNING...SO A PRIMARILY SNOW PTYPE EVENT REMAINS THE THINKING.
SIGNIFICANT WARM UP PROGGED FOR THE WEEKEND AS RIDGING TAKES PLACE
BEHIND EXITING SHORTWAVE. 850MB TEMPS REBOUND FROM NEAR FREEZING TO
8 TO 10C SAT ON THE GFS. BUMPED UP TEMPERATURES A FEW DEGREES ACROSS
THE BOARD AS WE GO ABOVE AVERAGE FOR THIS TIME OF YEAR. A WELCOMED
CHANGE BY MOST FROM THE COLD OF THE LAST WEEK. ANOTHER QUICK MOVING
SYSTEM IS POISED TO MOVE THROUGH SAT...BUT ONLY MODEST CAA BEHIND IT
KEEPS OUR TEMPERATURES FROM FALLING OFF DRAMATICALLY. ANOTHER SYSTEM
APPROACHES FROM THE SOUTH TO START NEXT WORK WEEK...BUT CONSIDERABLE
TIMING AND STRUCTURE DIFFERENCES EXIST ON HOW TO HANDLE THE SOUTHERN
CUTOFF TRACKING ACROSS THE SOUTHEAST.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
MAIN ARCTIC FRONT APPROACHING THE RIDGES BY 18Z WITH SNOW SHOWERS
WITH AND BEHIND THE FRONT. SURFACE OBS ACROSS OHIO DEEP IN THE
COLD AIR STILL SHOWING SOME LIGHT SNOW AND BLOWING SNOW AND HAVE
KEPT A PERIOD OF TEMPO IFR MOST LOCATIONS THROUGH 21Z WITH IFR AT
TIMES ACROSS KDUJ AND KFKL INTO THE EVENING. GENERAL VFR SHOULD BE
THE RULE LATER THIS EVENING INTO TUESDAY. WINDS WILL STAY UP
THROUGH TUESDAY WITH GUSTS OVER 25KT BEFORE SUBSIDING LATER
TUESDAY.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
THE NEXT CHANCE FOR RESTRICTIONS WILL BE LATE THURSDAY OR
FRIDAY. OTHERWISE GENERAL VFR.
&&
.CLIMATE...
VERY COLD AIR IS EXPECTED ACROSS THE REGION EARLY THIS WEEK. A
SUMMARY OF SIGNIFICANT COLD TEMPERATURE READINGS IS INCLUDED
BELOW...
CITY MON/TUE LAST DATE LAST DATE LAST DATE
RECORD(YEAR) BELOW -10 BELOW 0 HIGH BELOW 0
PITTSBURGH -5(1942)/-5(1884) 1/17/2009 1/22/2011 1/19/1994
MORGANTOWN -1(1988)/-4(1970) 1/21/1994 1/17/2009 1/19/1994
ZANESVILLE -3(1959)/-3(1968) 1/22/2011 1/24/2011 1/19/1994
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR MDZ001.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ001.
OH...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ074-
076.
WV...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR WVZ001>004-
012-021>023-041.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ023-
041.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
832 PM EST TUE JAN 7 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 329 PM EST TUE JAN 7 2014
DANGEROUSLY COLD AIR WILL FINALLY MOVE OUT OF THE GREAT LAKES REGION
AND HIGH TEMPERATURES ON WEDNESDAY WILL BE IN THE TEENS.
TEMPERATURES WILL CONTINUE TO MODERATE AND HIGHS ABOVE FREEZING ARE
EXPECTED FRIDAY THROUGH MONDAY. SOME RAIN OR FREEZING RAIN MAY
ACCOMPANY THE WARM UP FROM LATE FRIDAY INTO EARLY SATURDAY.
&&
.UPDATE...
ISSUED AT 832 PM EST TUE JAN 7 2014
WE HAVE FRESHENED UP THE FCST THIS EVENING...MAINLY TO TWEAK TEMPS
A BIT AS SOME LOCATIONS HAVE DROPPED BELOW THEIR FCST MINS. TEMP
TRENDS HAVE BEEN ALL OVER THE PLACE THIS EVENING ACROSS THE CWFA.
THE WARMEST TEMPS HAVE BEEN FOUND ALONG THE LAKESHORE AS EXPECTED.
THE NRN INLAND LOCATIONS HAVE REMAINED UP A LITTLE...WHILE THE SRN
ROW OF COUNTIES REMAIN NEAR OR SLIGHTLY BELOW ZERO WITHOUT THE
INFLUENCE FROM LAKE MICHIGAN.
MODEL TRENDS OVERNIGHT ARE ALL OVER THE PLACE ALSO. THE NAM AND
GFS WANT TO SLOWLY WARM TEMPS FOR THE MOST PART...WHILE SHORT TERM
HI RES GUIDANCE LIKE THE HRRR RUC DROP TEMPS PRETTY GOOD. WE HAVE
TO BELIEVE THAT TEMPS SHOULD DROP A LITTLE AS WIND DIMINISH
TONIGHT. AREAS THAT POTENTIALLY CLEAR OUT LIKE THE FAR SOUTH WITH
LESS INFLUENCE FROM LAKE MICHIGAN WILL HAVE A BETTER CHC OF
DROPPING A FEW DEGREES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 329 PM EST TUE JAN 7 2014
WILL MAKE THE TRANSITION AT THIS TIME FROM WARNINGS TO ADVISORIES AS
GRADUAL IMPROVEMENT IN WIND CHILLS AND EXTENT OF SNOW AND BLOWING
SNOW WILL BE TAKING PLACE TONIGHT AND WEDNESDAY. WILL DOWNGRADE TO
A WINTER WEATHER ADVISORY ALONG THE LAKESHORE PLUS KENT COUNTY FOR A
COMBINATION OF LIGHT SNOW SHOWERS AND WIND CHILLS NEAR 10 BELOW.
ELSEWHERE WILL DOWNGRADE THE WIND CHILL WARNING TO A WIND CHILL
ADVISORY FOR WIND CHILLS OF 10 TO 20 BELOW.
THE COLDEST WIND CHILL READINGS FOR TONIGHT SHOULD OCCUR THIS
EVENING BEFORE THE WINDS DIMINISH. CURRENT WIND CHILLS HAVE
RECOVERED TO 5 TO 15 BELOW DOWNWIND OF LK MI AND TO 20 TO 25 ALONG
THE I-94 CORRIDOR. THESE VALUES WILL REMAIN COMMON FOR THE NEXT FEW
HOURS BEFORE NUDGING UP A FEW DEGREES.
VISIBILITIES AT THE LAKESHORE HAVE IMPROVED A TAD BUT MANY SITES ARE
STILL UNDER ONE MILE. LAKE EFFECT ECHOES HAVE LOOKED GENERALLY WEAK
TODAY WITH INVERSION HEIGHTS ONLY AROUND 4500 FT. BUFKIT PROFILES
SHOW THE DGZ WHICH IS CURRENTLY NEAR THE GROUND LIFTING BACK UP INTO
THE CLOUD LAYER TONIGHT AS SLIGHT WARMING TAKES PLACE. DECENT LIFT
IS INDICATED IN THE DGZ AS WELL. THIS IMPLIES THAT LAKE EFFECT SNOW
INTENSITY MAY INCREASE AGAIN THIS EVENING THROUGH EARLY WEDNESDAY...
OR AT LEAST CHANGE FROM SMALL/FINE FLAKES TO FLUFFY DENDRITES THAT
ACCUMULATE MORE EFFICIENTLY. THE LAKE EFFECT SNOW WILL GRADUALLY END
ON WEDNESDAY AFTERNOON AND EVENING AS SFC HIGH PRESSURE MOVES IN.
A LIMITING FACTOR FOR LAKE EFFECT IS THAT ICE COVERAGE ON LK MI IS
INCREASING WHICH MEANS SHORTER FETCH LENGTHS AND PARCEL RESIDENCE
TIMES. UNFORTUNATELY THE EXACT EXTENT OF THE ICE COVERAGE ON THE
LAKE IS UNCLEAR AT THIS TIME DUE TO THE EXTENSIVE CLOUD COVER. WEB
CAMS ALONG THE SHORE DO REVEAL CONSIDERABLE ICE HOWEVER.
THE SET UP LOOKS GOOD FOR VERY COLD TEMPS ON WEDNESDAY NIGHT AS
CLEARING SKIES AND LIGHT WINDS COUPLED WITH DEEP/FRESH SNOWPACK LEAD
TO IDEAL RADIATIONAL COOLING. SOME LIGHT SNOW IS POSSIBLE LATE
THURSDAY AND THURSDAY NIGHT RELATED TO WEAK ISENTROPIC LIFT.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 329 PM EST TUE JAN 7 2014
TEMPERATURES ARE LOOKING WARMER THROUGH THE EXTENDED PERIOD AND WITH
THOSE WARMER TEMPERATURES WILL COME SOME P-TYPE ISSUES.
A HIGH AMPLITUDE TROUGH WILL FROM THE MIDDLE OF THE COUNTRY TOWARD
THE GREAT LAKES FRIDAY. ISENTROPIC LIFT AHEAD OF THE TROUGH WILL
RESULT IN PCPN DEVELOPMENT. LOW TEMPERATURES FRIDAY NIGHT ARE
EXPECTED NEAR TO JUST BELOW FREEZING. FORECAST SOUNDINGS POINT
TOWARD MORE RAIN THAN SNOW DEVELOPMENT. EVEN IF TEMPERATURES ARE
JUST ABOVE FREEZING NEAR THE SURFACE...GROUND-LEVEL TEMPERATURES
WILL LIKELY BE AT OR BELOW FREEZING. FREEZING RAIN SEEMS LIKE A REAL
POSSIBILITY FRIDAY NIGHT.
AFTER THE TROUGH PASSES THROUGH EARLY SATURDAY THE COLUMN COOLS
ENOUGH THAT SNOW WILL PROBABLY BE THE MAIN P-TYPE. SFC TEMPS IN THE
UPPER 30S WOULD ALSO LIKELY PRECLUDE FREEZING RAIN.
ANOTHER TROUGH IS PROGD TO MOVE THROUGH SUNDAY NIGHT/MONDAY FOLLOWED
BY ANOTHER MONDAY NIGHT/TUESDAY. EACH WILL BRING ANOTHER SHOT OF
COOLER AIR...BUT NOT FRIGID LIKELY WE/VE SEEN RECENTLY. WE/LL BE
LOOKING AT SNOW SHOWERS SUNDAY NIGHT THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 634 PM EST TUE JAN 7 2014
THE AREA OF SNOW SHOWERS CONTINUES TO DIMINISH AS THE COLDEST AIR
MOVES AWAY FROM THE AREA. HOWEVER THERE IS ANOTHER SHORTWAVE
HEADING INTO SOUTHWEST MICHIGAN IN THE 02-05Z TIME FRAME THAT
SHOULD INCREASE BOTH THE INTENSITY AND COVERAGE OF THE SNOW
SHOWERS AGAIN. FOR THE MKG AND GRR TAFS SITES I EXPECT THE SNOW
SHOWERS WILL LARGELY CONTINUE THROUGH MOST OF THE FORECAST.
MEANWHILE FOR THE OTHER TAF SITES...WITH THE COLD AIR RETREATING
AS IT IS... SURFACE WINDS ARE MORE SOUTHERLY SO SKIES HAVE AT JXN
AND I EXPECT SKIES SHOULD FOR THE MOST PART STAY CLEAR THERE.
AZO...BTL AND LAN ARE ON THE EDGE OF THE CLOUDS BUT WITH A MORE
SOUTHERLY LOW LEVEL WIND I WOULD THINK AZO AND BTL AT LEAST COULD
SEE SOME ADDITIONAL CLEARING MID TO LATE EVENING. THE RAP AND NAM
SHOW THE LOW CLOUDS MOVING BACK IN BY 09Z SO THAT IS WHAT I PUT IN
THE TAFS.
&&
.MARINE...
ISSUED AT 329 PM EST TUE JAN 7 2014
WILL CANCEL THE GALE AND HEAVY FREEZING SPRAY WARNINGS WITH WINDS
GRADUALLY SUBSIDING TONIGHT AND WEDNESDAY.
&&
.HYDROLOGY...
ISSUED AT 417 PM EST TUE JAN 7 2014
HYDRO CONCERNS ARE RELATIVELY MINIMAL IN THE SHORT TERM. RIVERS ARE
LOCKED IN OR GRADUALLY FALLING IN THE VERY COLD AIR. THE FLOOD
ADVISORY FOR THE FLAT RIVER AT SMYRNA WAS CANCELED MONDAY NIGHT. THE
WHITE RIVER AT WHITEHALL WAS EXHIBITING A SHARP RISE UNTIL CRESTING
THIS MORNING. IT HAS SINCE LEVELED OFF.
RIVERS WILL CONTINUE GAINING ICE COVERAGE AND THICKNESS THROUGH
THURSDAY. A WARM UP IS ON THE WAY FOR FRIDAY THROUGH EARLY NEXT
WEEK. HIGHS ABOVE FREEZING IN THE 30S TO NEAR 40 ARE EXPECTED
ALONG WITH A MIX OF RAIN AND SNOW FRIDAY AND SATURDAY. AT THIS
POINT WE DO NOT ANTICIPATE ISSUES WITH ICE JAMMING AND FLOODING
WITH THIS MINOR WARMUP. EVEN SO..RESIDENTS WHO LIVE ON RIVER BANKS
SHOULD CONTINUE TO WATCH FOR ANY ICE MOVEMENT WHICH COULD LEAD TO
ICE JAMS AND RISES IN RIVER LEVELS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 9 AM EST WEDNESDAY FOR MIZ037-043-
050-056-057-064-071.
WIND CHILL ADVISORY UNTIL 9 AM EST WEDNESDAY FOR MIZ038>040-
044>046-051-052-058-059-065>067-072>074.
LM...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR LMZ844>849.
&&
$$
UPDATE...NJJ
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...93
AVIATION...WDM
HYDROLOGY...HOVING/WALTON
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
634 PM EST TUE JAN 7 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 329 PM EST TUE JAN 7 2014
DANGEROUSLY COLD AIR WILL FINALLY MOVE OUT OF THE GREAT LAKES REGION
AND HIGH TEMPERATURES ON WEDNESDAY WILL BE IN THE TEENS.
TEMPERATURES WILL CONTINUE TO MODERATE AND HIGHS ABOVE FREEZING ARE
EXPECTED FRIDAY THROUGH MONDAY. SOME RAIN OR FREEZING RAIN MAY
ACCOMPANY THE WARM UP FROM LATE FRIDAY INTO EARLY SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 329 PM EST TUE JAN 7 2014
WILL MAKE THE TRANSITION AT THIS TIME FROM WARNINGS TO ADVISORIES AS
GRADUAL IMPROVEMENT IN WIND CHILLS AND EXTENT OF SNOW AND BLOWING
SNOW WILL BE TAKING PLACE TONIGHT AND WEDNESDAY. WILL DOWNGRADE TO
A WINTER WEATHER ADVISORY ALONG THE LAKESHORE PLUS KENT COUNTY FOR A
COMBINATION OF LIGHT SNOW SHOWERS AND WIND CHILLS NEAR 10 BELOW.
ELSEWHERE WILL DOWNGRADE THE WIND CHILL WARNING TO A WIND CHILL
ADVISORY FOR WIND CHILLS OF 10 TO 20 BELOW.
THE COLDEST WIND CHILL READINGS FOR TONIGHT SHOULD OCCUR THIS
EVENING BEFORE THE WINDS DIMINISH. CURRENT WIND CHILLS HAVE
RECOVERED TO 5 TO 15 BELOW DOWNWIND OF LK MI AND TO 20 TO 25 ALONG
THE I-94 CORRIDOR. THESE VALUES WILL REMAIN COMMON FOR THE NEXT FEW
HOURS BEFORE NUDGING UP A FEW DEGREES.
VISIBILITIES AT THE LAKESHORE HAVE IMPROVED A TAD BUT MANY SITES ARE
STILL UNDER ONE MILE. LAKE EFFECT ECHOES HAVE LOOKED GENERALLY WEAK
TODAY WITH INVERSION HEIGHTS ONLY AROUND 4500 FT. BUFKIT PROFILES
SHOW THE DGZ WHICH IS CURRENTLY NEAR THE GROUND LIFTING BACK UP INTO
THE CLOUD LAYER TONIGHT AS SLIGHT WARMING TAKES PLACE. DECENT LIFT
IS INDICATED IN THE DGZ AS WELL. THIS IMPLIES THAT LAKE EFFECT SNOW
INTENSITY MAY INCREASE AGAIN THIS EVENING THROUGH EARLY WEDNESDAY...
OR AT LEAST CHANGE FROM SMALL/FINE FLAKES TO FLUFFY DENDRITES THAT
ACCUMULATE MORE EFFICIENTLY. THE LAKE EFFECT SNOW WILL GRADUALLY END
ON WEDNESDAY AFTERNOON AND EVENING AS SFC HIGH PRESSURE MOVES IN.
A LIMITING FACTOR FOR LAKE EFFECT IS THAT ICE COVERAGE ON LK MI IS
INCREASING WHICH MEANS SHORTER FETCH LENGTHS AND PARCEL RESIDENCE
TIMES. UNFORTUNATELY THE EXACT EXTENT OF THE ICE COVERAGE ON THE
LAKE IS UNCLEAR AT THIS TIME DUE TO THE EXTENSIVE CLOUD COVER. WEB
CAMS ALONG THE SHORE DO REVEAL CONSIDERABLE ICE HOWEVER.
THE SET UP LOOKS GOOD FOR VERY COLD TEMPS ON WEDNESDAY NIGHT AS
CLEARING SKIES AND LIGHT WINDS COUPLED WITH DEEP/FRESH SNOWPACK LEAD
TO IDEAL RADIATIONAL COOLING. SOME LIGHT SNOW IS POSSIBLE LATE
THURSDAY AND THURSDAY NIGHT RELATED TO WEAK ISENTROPIC LIFT.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 329 PM EST TUE JAN 7 2014
TEMPERATURES ARE LOOKING WARMER THROUGH THE EXTENDED PERIOD AND WITH
THOSE WARMER TEMPERATURES WILL COME SOME P-TYPE ISSUES.
A HIGH AMPLITUDE TROUGH WILL FROM THE MIDDLE OF THE COUNTRY TOWARD
THE GREAT LAKES FRIDAY. ISENTROPIC LIFT AHEAD OF THE TROUGH WILL
RESULT IN PCPN DEVELOPMENT. LOW TEMPERATURES FRIDAY NIGHT ARE
EXPECTED NEAR TO JUST BELOW FREEZING. FORECAST SOUNDINGS POINT
TOWARD MORE RAIN THAN SNOW DEVELOPMENT. EVEN IF TEMPERATURES ARE
JUST ABOVE FREEZING NEAR THE SURFACE...GROUND-LEVEL TEMPERATURES
WILL LIKELY BE AT OR BELOW FREEZING. FREEZING RAIN SEEMS LIKE A REAL
POSSIBILITY FRIDAY NIGHT.
AFTER THE TROUGH PASSES THROUGH EARLY SATURDAY THE COLUMN COOLS
ENOUGH THAT SNOW WILL PROBABLY BE THE MAIN P-TYPE. SFC TEMPS IN THE
UPPER 30S WOULD ALSO LIKELY PRECLUDE FREEZING RAIN.
ANOTHER TROUGH IS PROGD TO MOVE THROUGH SUNDAY NIGHT/MONDAY FOLLOWED
BY ANOTHER MONDAY NIGHT/TUESDAY. EACH WILL BRING ANOTHER SHOT OF
COOLER AIR...BUT NOT FRIGID LIKELY WE/VE SEEN RECENTLY. WE/LL BE
LOOKING AT SNOW SHOWERS SUNDAY NIGHT THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 634 PM EST TUE JAN 7 2014
THE AREA OF SNOW SHOWERS CONTINUES TO DIMINISH AS THE COLDEST AIR
MOVES AWAY FROM THE AREA. HOWEVER THERE IS ANOTHER SHORTWAVE
HEADING INTO SOUTHWEST MICHIGAN IN THE 02-05Z TIME FRAME THAT
SHOULD INCREASE BOTH THE INTENSITY AND COVERAGE OF THE SNOW
SHOWERS AGAIN. FOR THE MKG AND GRR TAFS SITES I EXPECT THE SNOW
SHOWERS WILL LARGELY CONTINUE THROUGH MOST OF THE FORECAST.
MEANWHILE FOR THE OTHER TAF SITES...WITH THE COLD AIR RETREATING
AS IT IS... SURFACE WINDS ARE MORE SOUTHERLY SO SKIES HAVE AT JXN
AND I EXPECT SKIES SHOULD FOR THE MOST PART STAY CLEAR THERE.
AZO...BTL AND LAN ARE ON THE EDGE OF THE CLOUDS BUT WITH A MORE
SOUTHERLY LOW LEVEL WIND I WOULD THINK AZO AND BTL AT LEAST COULD
SEE SOME ADDITIONAL CLEARING MID TO LATE EVENING. THE RAP AND NAM
SHOW THE LOW CLOUDS MOVING BACK IN BY 09Z SO THAT IS WHAT I PUT IN
THE TAFS.
&&
.MARINE...
ISSUED AT 329 PM EST TUE JAN 7 2014
WILL CANCEL THE GALE AND HEAVY FREEZING SPRAY WARNINGS WITH WINDS
GRADUALLY SUBSIDING TONIGHT AND WEDNESDAY.
&&
.HYDROLOGY...
ISSUED AT 417 PM EST TUE JAN 7 2014
HYDRO CONCERNS ARE RELATIVELY MINIMAL IN THE SHORT TERM. RIVERS ARE
LOCKED IN OR GRADUALLY FALLING IN THE VERY COLD AIR. THE FLOOD
ADVISORY FOR THE FLAT RIVER AT SMYRNA WAS CANCELED MONDAY NIGHT. THE
WHITE RIVER AT WHITEHALL WAS EXHIBITING A SHARP RISE UNTIL CRESTING
THIS MORNING. IT HAS SINCE LEVELED OFF.
RIVERS WILL CONTINUE GAINING ICE COVERAGE AND THICKNESS THROUGH
THURSDAY. A WARM UP IS ON THE WAY FOR FRIDAY THROUGH EARLY NEXT
WEEK. HIGHS ABOVE FREEZING IN THE 30S TO NEAR 40 ARE EXPECTED
ALONG WITH A MIX OF RAIN AND SNOW FRIDAY AND SATURDAY. AT THIS
POINT WE DO NOT ANTICIPATE ISSUES WITH ICE JAMMING AND FLOODING
WITH THIS MINOR WARMUP. EVEN SO..RESIDENTS WHO LIVE ON RIVER BANKS
SHOULD CONTINUE TO WATCH FOR ANY ICE MOVEMENT WHICH COULD LEAD TO
ICE JAMS AND RISES IN RIVER LEVELS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 9 AM EST WEDNESDAY FOR MIZ037-043-
050-056-057-064-071.
WIND CHILL ADVISORY UNTIL 9 AM EST WEDNESDAY FOR MIZ038>040-
044>046-051-052-058-059-065>067-072>074.
LM...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...93
AVIATION...WDM
HYDROLOGY...HOVING/WALTON
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 PM EST MON JAN 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST MON JAN 6 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF IN
CENTRAL NAMERICA AS ARCTIC/POLAR BRANCHES ARE IN THE PROCESS OF
PHASING...WITH THE AXIS OF LOWEST HGTS STRETCHING FM HUDSON BAY INTO
THE UPR MS RIVER VALLEY. WITHIN THE CORE OF THE COLDEST AIR...00Z
RAOBS SHOW H5/H85/H925 TEMPS AS LO AS -45C/-34C/-34C. THE PHASING OF
THE UPR BRANCHES IS SUPPORTING A DEEPENING SFC LO MOVING NNEWD INTO
SE ONTARIO. ALTHOUGH THE SYNOPTIC SCALE FORCING/PCPN ASSOCIATED WITH
THIS SFC LO ARE PASSING TO THE E OF UPR MI...SHARPENING CYC NNW FLOW
ON THE NW FLANK OF THE LO AND AREA OF DPVA/DEEP LYR QVECTOR CNVGC/
DEEPENING MID LVL MSTR AHEAD OF THE ARCTIC BRANCH SHRTWV ARE
IMPACTING MAINLY THE E HALF OF UPR MI...CAUSING AN INCRS IN LES
INTENSITY/COVERAGE IN THE FAVORED SN BELTS. AN AREA OF DEEPER MSTR
ALSO STRECHES FM NW ONTARIO S INTO MN UNDER THE AXIS OF LOWER HGTS.
TEMPS REMAIN WELL BLO NORMAL. 00Z H85 TEMPS OVER UPR MI RANGED FM
ABOUT -19C OVER THE SE TO -25C OVER THE W... SUPPORTING SFC TEMPS AS
LO AS -20F OVER THE FAR W NEAR THE WI BORDER EARLY THIS MRNG. THE
MORE NNW FLOW OFF LK SUP HAS MODERATED THE AIRMASS DOWNWIND OF THE
LK OVER THE ERN CWA...WHERE TEMPS NEAR LK SUP REMAIN CLOSE TO 10F.
THE INCRSG WINDS HAVE CAUSED WIND CHILLS TO FALL AS LO AS -35 TO
-40F OVER THE WRN CWA.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON HEADLINES RELATED TO
TEMPS/WIND CHILLS AS WELL AS LES/BLSN.
TDAY...SFC LO OVER SE ONTARIO EARLY THIS MRNG IS PROGGED TO LIFT
NEWD INTO QUEBEC AND INTENSIFY AS AXIS OF LOWEST HGTS ALF DRIFTS E
ACROSS THE UPR LKS. ALTHOUGH THE AREA OF SHARPER QVECTOR CNVGC TO
THE E OF THE UPR TROF IS PROGGED TO DRIFT TO THE E AND AWAY FM
NEWBERRY BY LATE AFTN...AREA OF DEEPER MSTR/CORE OF COLDER AIR NOTED
TO THE W IS PROGGED TO DRIFT E THRU THE UPR LKS AS WELL. THE COLDEST
H85 TEMPS ARE FCST TO PASS TO THE S THRU WI...BUT THE STEADILY
BACKING LLVL FLOW TOWARD THE W BY 00Z TUE ASSOCIATED WITH THE
DEPARTING SFC LO TO THE NE WL ALLOW FOR LESS LK SUP MODERATION OF
THE BITTERLY COLD AIRMASS. THE FOCUS OF THE HIER LES POPS WL SHIFT
AS WELL WITH THESE BACKING WINDS. ALTHOUGH ABSENCE OF DGZ WITH
BITTERLY COLD AIR WL LIMIT SN ACCUMS OVER THE W...ARRIVAL OF DEEPER
MSTR WL KEEP CONTINUOUS -SHSN GOING. SMALL SN FLAKES WL EFFICIENTLY
REDUCE VSBY AS BLSN INCREASES WITH SLOWLY INCRSG WINDS. EXPECT
SOMEWHAT HEAVIER SHSN OVER THE E WHERE LES ADVY IS IN PLACE GIVEN
SOME LINGERING DYNAMIC FORCING/WARMER AIR THAT DOES NOT HAMPER SN
GROWTH AS MUCH... BUT THE SHIFTING WINDS WL TEND TO CAUSE THE LES
BANDS TO DRIFT AS WELL. AS FOR TEMPS/WIND CHILLS...EXPECT LTL IF ANY
DIURNAL RECOVERY WITH BACKING LLVL FLOW LIMITING LK MODERATION. OVER
THE E...THIS BACKING FLOW MAY CAUSE TEMPS TO FALL. SINCE WIND SPEEDS
WL BE ON THE INCRS AS WELL...GOING WIND CHILL HEADLINES SEEM TO BE
ON TRACK.
TNGT...MODELS HINT ANOTHER SHRTWV DIVING SEWD ARND SLOWLY DEPARTING
UPR TROF AXIS WL MOVE INTO THE UPR LKS...BRINGING ANOTHER ROUND OF
DPVA/DEEP LYR QVECTOR CNVGC THAT MAINTAINS DEEPER MSTR. AS THE SFC
FLOW BACKS WITH LAND BREEZE ENHANCEMENT...LLVL CNVGC WL INCRS OVER
NRN ONTONAGON/CENTRAL HOUGHTON COUNTIES AND NEAR LK SUP E OF
MUNISING. THIS INCRSG LAND BREEZE COMPONENT WL TEND TO ADVECT LESS
MODIFIED AIR INTO THE CWA AND OFFSET SLOWLY MODERATING H85 TEMPS
WITH PASSAGE OF COLDEST CORE TO THE E. SINCE THE LLVL WINDS ARE FCST
TO INCRS AS WELL...WARNING THRESHOLD WIND CHILLS ARE LIKELY OVER
ALMOST ALL OF THE CWA.
AS FOR HEADLINES...GOING WIND CHILL WARNINGS APPEAR TO BE ON TRACK
EVEN THOUGH MORE LK MODIFIED AIR HAS MAINTAINED HIER TEMPS OVER
ABOUT THE E HALF OF THE CWA. BACKING/INCRSG WINDS LATER TDAY/TNGT
SHOULD ADVECT SUFFICIENTLY COLD AIR OVER THE ENTIRE CWA TO JUSTIFY
MAINTAINING ALL WIND CHILL WRNGS. ALTHOUGH SN AMOUNTS OVER THE W ARE
NOT LIKELY TO REACH ADVY THRESHOLDS...OPTED TO ISSUE AN LES ADVY FOR
ONTONAGON COUNTY THRU THE KEWEENAW THRU TUE TO ACCOUNT FOR THE
FREQUENT WHITEOUTS THAT WL LIKELY OCCUR WITH THE FALLING AND BLOWING
OF THE SMALL SN FLAKES. EXTENDED THE LES ADVY FOR ALGER/LUCE
COUNTIES THRU TUE AS WELL GIVEN THE POTENTIAL FOR HEAVIER SHSN
ESPCIALLY NEAR LK SUP E OF PICTURED ROCKS IN THE SHARPER LLVL CNVGC
THAT WL DVLP WITH SHARPENING LAND BREEZE CNVGC/WARMER H85 TEMPS THAT
WL NOT IMPACT SN GROWTH AS MUCH AS OVER THE W.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 431 PM EST MON JAN 6 2014
THE UPPER GREAT LAKES REGION WILL BE ON THE WEST SIDE OF THE
DEPARTING POLAR VORTEX ON TUESDAY NIGHT. THERE WILL STILL BE PLENTY
OF COLD AIR (850MB TEMPS AROUND -19C) TO PRODUCE LAKE EFFECT OVER
THE AREA...LARGELY IN THE WEST-NORTHWEST WIND SNOW BELTS. THERE
ARE A COUPLE LIMITED FACTORS TO THE SNOWFALL. FIRST...INVERSION
HEIGHTS WILL BE FALLING TO (3-5KFT) IN ASSOCIATION WITH THE 1030MB
HIGH MOVING INTO THE NORTHERN PLAINS. SECOND...FOR MUCH OF TUESDAY
NIGHT AND WEDNESDAY...WINDS LOOK TO BE CONSISTENTLY OUT OF THE
WEST-NORTHWEST...WHICH SHOULD KEEP LAKE EFFECT IN THE WIND
PARALLEL BANDS AND LIMIT HIGHER AMOUNTS DUE TO ENHANCED
CONVERGENCE. ON THE POSITIVE SIDE...THE GRADUALLY WARMING 850MB
TEMPS THROUGH WEDNESDAY (REACHING -16C OVER WESTERN LAKE SUPERIOR)
WILL PUT MORE OF THE CLOUD INTO THE DGZ AND HAVE TRENDED SNOW
RATIOS UP INTO THE LOWER 20S. THUS...WILL CONTINUE TO SHOW DEFINITE
POPS IN THE WEST-NORTHWEST WIND SNOW BELTS TUESDAY NIGHT AND
WEDNESDAY...ALTHOUGH WILL START DECREASING THEM OVER THE WEST DUE TO
INCREASED DRY AIR FROM THE HIGH THAT WILL BE LOCATED NEAR
MINNEAPOLIS AT 00Z THURSDAY. HAVE THE HIGHEST AMOUNTS ON TUESDAY
NIGHT...GENERAL 1-3IN OVER THE KEWEENAW AND EAST OF GRAND MARAIS
(HIGHEST EAST)...BEFORE THE INVERSION FALLS AND WINDS BACK THROUGH
THE DAY WEDNESDAY AND KEEPS AMOUNTS LIGHTER. WILL BE CLOSE TO WIND
CHILL ADVISORY CRITERIA ON TUESDAY NIGHT...WITH WINDS STRUGGLING TO
REACH THE 10MPH VALUES NEEDED OVER THE INLAND AREAS. WITH THE COLD
AIR AND LIGHTER WINDS...WILL STILL SEE WIND CHILL VALUES IN THE -15
TO -35 DEGREE RANGE.
THE HIGH WILL SHIFT EAST ON WEDNESDAY NIGHT AND QUICKLY MERGE WITH
A HIGH IN THE MID ATLANTIC STATES ON THURSDAY. THIS WILL LEAD TO
THE LOW LEVEL WIND FIELD BACKING MORE TO THE SOUTHWEST AND PUSH THE
LAKE EFFECT NORTH ON THURSDAY MORNING. WITH MUCH OF THE CWA UNDER
CLEAR SKIES WEDNESDAY NIGHT AND PWAT VALUES AROUND 30 PERCENT OF
NORMAL...IT SHOULD BE ANOTHER COLD NIGHT WITH LOWS IN THE SINGLE
DIGITS AND TEENS BELOW ZERO. LIGHT WINDS WILL HELP REACH THOSE
LOWS...BUT ALSO LIMIT THE WIND CHILL VALUES TO VALUES ONLY SLIGHTLY
LOWER THAN THE LOWS.
WITH THE HIGH PRESSURE RIDGE SLIDING EAST DURING THE DAY
THURSDAY...A SHORT PERIOD OF ZONAL FLOW OVER THE NORTHERN CONUS
WILL LEAD TO A WEAK SHORTWAVE AND MODERATING TEMPERATURES. AT THIS
POINT...MODELS IN DECENT AGREEMENT ON THE SHORTWAVE TRACKING
ACROSS SOUTHERN ONTARIO. WARM AIR ADVECTION AHEAD OF THIS WAVE WILL
LEAD TO INCREASING CLOUDS OVER THE AREA. THERE COULD BE SOME SNOW
SHOWERS ASSOCIATED WITH THE WARM AIR ADVECTION...BUT WITH THE TRACK
OF THE SHORTWAVE WOULD EXPECT MUCH OF IT TO MISS THE LAND AREAS OF
THE CWA. THE KEWEENAW WOULD BE THE CLOSEST TO THE WAVE AND THUS
HAVE CONTINUED SLIGHT CHANCE POPS FOR THE THURSDAY AFTERNOON AND
THURSDAY EVENING TIME PERIOD.
AREA WILL BE BETWEEN WAVES OVERNIGHT THURSDAY INTO FRIDAY
MORNING...BEFORE THE NEXT DISTURBANCE EXITS THE PACIFIC NORTHWEST
AND MOVES THROUGH THE UPPER GREAT LAKES ON FRIDAY AFTERNOON AND
SATURDAY. MODELS HAVE BEEN DIFFERING SOME ON THIS
DISTURBANCE...BUT THE 12Z GFS/ECMWF HAVE COME INTO BETTER
AGREEMENT ON THE NORTHERN STREAMS INTERACTION WITH THE SOUTHERN
JET. LATEST TRENDS HAVE THE UPPER JET STRENGTHENING AND QUICKLY
SWEEPING THE FAVORABLE LEFT FRONT REGION OF THE JET ACROSS THE AREA
FRIDAY AFTERNOON AND EVENING. WOULD LIKE TO SEE A LITTLE MORE
CONSISTENCY BEFORE TRENDING POPS UP WITH THIS WAVE...SO HAVE CHANCE
POPS OVER THE EAST HALF WHILE THIS WAVE MOVES THROUGH.
A WEAK HIGH PRESSURE RIDGE WILL LIKELY SLIDE THROUGH ON SATURDAY
NIGHT AND DIMINISH PRECIP CHANCES. 850MB TEMPS LOOK MARGINAL FOR
LES SO WILL ONLY LINGER SLIGHT CHANCES NEAR LAKE SUPERIOR. NEXT
WAVE ARRIVES ON SUNDAY AND BRING ANOTHER QUICK CHANCE OF PRECIP TO
THE AREA BEFORE ANOTHER HIGH PRESSURE RIDGE ARRRIVES FOR MONDAY.
THE TRANSITION TO MORE ZONAL FLOW ON THURSDAY AND THEN PERIODS OF
WAVES ARRIVING FROM THE PACIFIC NORTHWEST WILL LEAD TO MORE
MODERATE CONDITIONS ACROSS THE AREA FOR THE SECOND HALF OF THE WORK
WEEK AND INTO THE WEEKEND. ALTHOUGH THE TEMPERATURES WILL STRUGGLE
TO RISE INITIALLY DUE TO THE EXPECTED INVERSION AROUND 925MB...THE
PERSISTENT WEST TO SOUTHWEST FLOW WILL LEAD TO MODERATING NEAR
SURFACE TEMPS. CURRENT FORECAST HAS TEMPERATURES RISING TO NORMAL
VALUES ON FRIDAY AND THEN ABOVE NORMAL (AROUND FREEZING) FOR THE
WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1226 PM EST MON JAN 6 2014
EXTREMELY COLD AIR MASS MOVING ACROSS THE UPPER GREAT LAKES WILL
CONTINUE TO GENERATE LAKE EFFECT SNOW SHOWERS OFF LAKE SUPERIOR.
WITH WNW FLOW...KCMX/KIWD WILL BE IMPACTED BY SNOW SHOWERS...MOST
SIGNIFICANTLY AT KCMX. COMBINATION OF FALLING AND BLOWING OF THE
SMALL SNOWFLAKES AT THESE LOCATIONS WILL RESULT IN PREVAILING IFR
CONDITIONS AT KIWD AND LIFR AT KCMX. WITH KCMX MORE EXPOSED IN A WNW
WIND AND WITH BOUNDARY LAYER WINDS INCREASING...VLIFR CONDITIONS
WILL BECOME THE RULE AT KCMX THIS EVENING...IF NOT BEFORE...AND THAT
WILL CONTINUE THRU TUE MORNING. SOME IMPROVEMENT WILL BEGIN AT KIWD
TUE MORNING AND PERHAPS AT KCMX NEAR THE END OF THIS FCST PERIOD AS
WINDS DIMINISH SLOWLY AND DEEPER MOISTURE DEPARTS/INVERSIONS FALL...
RESULTING IN DIMINISHING LAKE EFFECT SNOW SHOWERS. THOUGH SOME
PERIODS OF HIGH MVFR CIGS WILL OCCUR THIS AFTN...EXPECT VFR
CONDITIONS TO PREDOMINATE AT KSAW WITH A DOWNSLOPE WNW WIND
COMPONENT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST MON JAN 6 2014
WITH SHARPENING PRES GRADIENT AND FLOW OF ARCTIC AIR OVER THE
RELATIVELY WARM LK WATERS...EXPECT WNW WINDS 30 KTS TO GALES TO 35
KTS THRU TONIGHT INTO TUESDAY EVENING. MAINTAINED GOING GALE
WARNINGS. THE COMBINATION OF THE BITTER COLD/SIGNIFICANT WAVE ACTION
WILL RESULT IN WIDESPREAD HEAVY FREEZING SPRAY AS WELL...SO LEFT THE
HEAVY FREEZING SPRAY WARNINGS IN EFFECT THROUGH WEDNESDAY MORNING.
OTHERWISE...HIGH PRESSURE WILL MAKE ITS WAY SOUTH OF LAKE SUPERIOR
BY MID WEEK...BUT A PERSISTANT LOW PRESSURE TROUGH NORTH OF THE LAKE
WILL KEEP WNW WINDS GUSTING TO 15 TO 25 KTS THROUGH THURSDAY.
TOWARDS THE LATTER PORTION OF THE WEEK...ANOTHER LOW PRESSURE TROUGH
WILL APPROACH THE GREAT LAKES FROM THE NORTHERN PLAINS...BACKING
WINDS TO THE SOUTHWEST AT 15 TO 25 KNOTS FOR THURSDAY AND FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 11 AM EST /10 AM CST/ TUESDAY FOR
MIZ001>005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ085.
WIND CHILL WARNING UNTIL 11 AM EST TUESDAY FOR MIZ006-007-014-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ001>003-
006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC/MCD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1227 PM EST MON JAN 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST MON JAN 6 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF IN
CENTRAL NAMERICA AS ARCTIC/POLAR BRANCHES ARE IN THE PROCESS OF
PHASING...WITH THE AXIS OF LOWEST HGTS STRETCHING FM HUDSON BAY INTO
THE UPR MS RIVER VALLEY. WITHIN THE CORE OF THE COLDEST AIR...00Z
RAOBS SHOW H5/H85/H925 TEMPS AS LO AS -45C/-34C/-34C. THE PHASING OF
THE UPR BRANCHES IS SUPPORTING A DEEPENING SFC LO MOVING NNEWD INTO
SE ONTARIO. ALTHOUGH THE SYNOPTIC SCALE FORCING/PCPN ASSOCIATED WITH
THIS SFC LO ARE PASSING TO THE E OF UPR MI...SHARPENING CYC NNW FLOW
ON THE NW FLANK OF THE LO AND AREA OF DPVA/DEEP LYR QVECTOR CNVGC/
DEEPENING MID LVL MSTR AHEAD OF THE ARCTIC BRANCH SHRTWV ARE
IMPACTING MAINLY THE E HALF OF UPR MI...CAUSING AN INCRS IN LES
INTENSITY/COVERAGE IN THE FAVORED SN BELTS. AN AREA OF DEEPER MSTR
ALSO STRECHES FM NW ONTARIO S INTO MN UNDER THE AXIS OF LOWER HGTS.
TEMPS REMAIN WELL BLO NORMAL. 00Z H85 TEMPS OVER UPR MI RANGED FM
ABOUT -19C OVER THE SE TO -25C OVER THE W... SUPPORTING SFC TEMPS AS
LO AS -20F OVER THE FAR W NEAR THE WI BORDER EARLY THIS MRNG. THE
MORE NNW FLOW OFF LK SUP HAS MODERATED THE AIRMASS DOWNWIND OF THE
LK OVER THE ERN CWA...WHERE TEMPS NEAR LK SUP REMAIN CLOSE TO 10F.
THE INCRSG WINDS HAVE CAUSED WIND CHILLS TO FALL AS LO AS -35 TO
-40F OVER THE WRN CWA.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON HEADLINES RELATED TO
TEMPS/WIND CHILLS AS WELL AS LES/BLSN.
TDAY...SFC LO OVER SE ONTARIO EARLY THIS MRNG IS PROGGED TO LIFT
NEWD INTO QUEBEC AND INTENSIFY AS AXIS OF LOWEST HGTS ALF DRIFTS E
ACROSS THE UPR LKS. ALTHOUGH THE AREA OF SHARPER QVECTOR CNVGC TO
THE E OF THE UPR TROF IS PROGGED TO DRIFT TO THE E AND AWAY FM
NEWBERRY BY LATE AFTN...AREA OF DEEPER MSTR/CORE OF COLDER AIR NOTED
TO THE W IS PROGGED TO DRIFT E THRU THE UPR LKS AS WELL. THE COLDEST
H85 TEMPS ARE FCST TO PASS TO THE S THRU WI...BUT THE STEADILY
BACKING LLVL FLOW TOWARD THE W BY 00Z TUE ASSOCIATED WITH THE
DEPARTING SFC LO TO THE NE WL ALLOW FOR LESS LK SUP MODERATION OF
THE BITTERLY COLD AIRMASS. THE FOCUS OF THE HIER LES POPS WL SHIFT
AS WELL WITH THESE BACKING WINDS. ALTHOUGH ABSENCE OF DGZ WITH
BITTERLY COLD AIR WL LIMIT SN ACCUMS OVER THE W...ARRIVAL OF DEEPER
MSTR WL KEEP CONTINUOUS -SHSN GOING. SMALL SN FLAKES WL EFFICIENTLY
REDUCE VSBY AS BLSN INCREASES WITH SLOWLY INCRSG WINDS. EXPECT
SOMEWHAT HEAVIER SHSN OVER THE E WHERE LES ADVY IS IN PLACE GIVEN
SOME LINGERING DYNAMIC FORCING/WARMER AIR THAT DOES NOT HAMPER SN
GROWTH AS MUCH... BUT THE SHIFTING WINDS WL TEND TO CAUSE THE LES
BANDS TO DRIFT AS WELL. AS FOR TEMPS/WIND CHILLS...EXPECT LTL IF ANY
DIURNAL RECOVERY WITH BACKING LLVL FLOW LIMITING LK MODERATION. OVER
THE E...THIS BACKING FLOW MAY CAUSE TEMPS TO FALL. SINCE WIND SPEEDS
WL BE ON THE INCRS AS WELL...GOING WIND CHILL HEADLINES SEEM TO BE
ON TRACK.
TNGT...MODELS HINT ANOTHER SHRTWV DIVING SEWD ARND SLOWLY DEPARTING
UPR TROF AXIS WL MOVE INTO THE UPR LKS...BRINGING ANOTHER ROUND OF
DPVA/DEEP LYR QVECTOR CNVGC THAT MAINTAINS DEEPER MSTR. AS THE SFC
FLOW BACKS WITH LAND BREEZE ENHANCEMENT...LLVL CNVGC WL INCRS OVER
NRN ONTONAGON/CENTRAL HOUGHTON COUNTIES AND NEAR LK SUP E OF
MUNISING. THIS INCRSG LAND BREEZE COMPONENT WL TEND TO ADVECT LESS
MODIFIED AIR INTO THE CWA AND OFFSET SLOWLY MODERATING H85 TEMPS
WITH PASSAGE OF COLDEST CORE TO THE E. SINCE THE LLVL WINDS ARE FCST
TO INCRS AS WELL...WARNING THRESHOLD WIND CHILLS ARE LIKELY OVER
ALMOST ALL OF THE CWA.
AS FOR HEADLINES...GOING WIND CHILL WARNINGS APPEAR TO BE ON TRACK
EVEN THOUGH MORE LK MODIFIED AIR HAS MAINTAINED HIER TEMPS OVER
ABOUT THE E HALF OF THE CWA. BACKING/INCRSG WINDS LATER TDAY/TNGT
SHOULD ADVECT SUFFICIENTLY COLD AIR OVER THE ENTIRE CWA TO JUSTIFY
MAINTAINING ALL WIND CHILL WRNGS. ALTHOUGH SN AMOUNTS OVER THE W ARE
NOT LIKELY TO REACH ADVY THRESHOLDS...OPTED TO ISSUE AN LES ADVY FOR
ONTONAGON COUNTY THRU THE KEWEENAW THRU TUE TO ACCOUNT FOR THE
FREQUENT WHITEOUTS THAT WL LIKELY OCCUR WITH THE FALLING AND BLOWING
OF THE SMALL SN FLAKES. EXTENDED THE LES ADVY FOR ALGER/LUCE
COUNTIES THRU TUE AS WELL GIVEN THE POTENTIAL FOR HEAVIER SHSN
ESPCIALLY NEAR LK SUP E OF PICTURED ROCKS IN THE SHARPER LLVL CNVGC
THAT WL DVLP WITH SHARPENING LAND BREEZE CNVGC/WARMER H85 TEMPS THAT
WL NOT IMPACT SN GROWTH AS MUCH AS OVER THE W.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 448 AM EST MON JAN 6 2014
THE 500MB LOW RESPONSIBLE FOR THE ACTIVE WEATHER ACROSS THE GREAT
LAKES THIS WEEK WILL BE OVER QUEBEC TUESDAY MORNING. THIS LOW WILL
LINGER A TROUGH OVER THE GREAT LAKES THROUGH THE DAY TUESDAY AND
WEDNESDAY. AT THE SURFACE...HIGH PRESSURE WILL SINK TOWARDS THE GULF
OF MEXICO. THE SURFACE LOW OVER THE LOWER LAKES MONDAY NIGHT WILL
MAKE ITS WAY INTO QUEBEC BY TUESDAY...KEEPING A WEAK TROUGH OVER
EASTERN LAKE SUPERIOR THROUGH WEDNESDAY. OVERALL...UPPER MI WILL
REMAIN IN WEST-NORTHWEST FLOW THROUGH THE FIRST PORTION OF THE LONG
TERM...CAUGHT BETWEEN THE HIGH IN THE SOUTHEAST AND THE LOW IN
QUEBEC. THOUGH WINDS WILL BE GUSTY THROUGH MOST OF TUESDAY...THEY
WILL GRADUALLY LESSEN AS THE HIGH MAKES ITS WAY INTO THE CWA TUESDAY
NIGHT INTO WEDNESDAY. WITH THE COLD ARCTIC AIR IN PLACE...LES WILL
CONTINUE IN WNW-WIND FAVORED SNOWBELTS. WITH DWINDLING
MOISTURE/EXTREME COLD...SNOW RATIOS WILL BE UNSUPPORTIVE OF
SIGNIFICANT ACCUMULATIONS ACROSS THE AREA FOR THIS TIME PERIOD. FOR
NOW HAVE 2 TO 4 INCHES OF ACCUMULATION FROM TUESDAY MORNING INTO
WEDNESDAY MORNING FOR EASTERN ALGER/LUCE COUNTY...AND 1 TO 2 INCHES
ACROSS ONTONAGON...HOUGHTON...AND KEWEENAW COUNTY.
THE MAIN CONCERN WILL BE LOWERED VISIBILITY DUE TO THE SMALL FLAKE
SIZE AND BLOWING SNOW/FROM GUSTY WNW WINDS/ NEAR THE LAKESHORE ALL
DAY TUESDAY...AND WIND CHILLS THROUGH LATE TUESDAY MORNING. FOR
HEADLINES...HAVE LES ADVISORY THROUGH TUESDAY IN WNW WIND FAVORED
SNOWBELTS...MAINLY ONTONAGON....NORTHERN
HOUGHTON...KEWEENAW...ALGER...AND LUCE COUNTIES TO ACCOUNT FOR THE
SNOW/BLOWING SNOW/WIND CHILL. ELSEWHERE...SOLELY THE WIND CHILL
WARNING REMAINS IN EFFECT. WIND CHILLS TUESDAY MORNING WILL RANGE
FROM -50F TO -25F ACROSS THE FORECAST AREA...WITH THE COLDEST
READINGS ACROSS THE INTERIOR WEST.
THE HIGH WILL GRADUALLY CROSS THE GREAT LAKES LATE WEDNESDAY INTO
THURSDAY...AND THEN REACH THE NEW ENGLAND STATES BY THURSDAY NIGHT.
AS THE HIGH MOVES OUT...WINDS BACK TO THE SOUTHWEST. THIS BRINGS
EXTREMELY DRY AIR INTO MUCH OF THE CWA BY EARLY WEDNESDAY
EVENING...STARTING A DISSIPATING TREND TO THE LES THROUGH THURSDAY
MORNING. ADDITIONALLY...WITH WINDS BACKING SOUTHWEST...MOST OF THE
REMAINING LES WILL MOVE OFFSHORE INTO LAKE SUPERIOR. THE BEST CHANCE
FOR SNOW SHOWERS ON THURSDAY IS OVER THE KEWEENAW.
MODELS BEGIN TO DISAGREE LATE THURSDAY INTO FRIDAY ON HOW TO HANDLE
AN UPPER LEVEL TROUGH MOVING INTO THE NORTHERN PLAINS...BOTH WITH
THE TIME AND STRENGTH OF THE OVERALL FEATURE. THE ECMWF BRINGS A
MORE SHALLOW TROUGH ACROSS THE GREAT LAKES FRIDAY NIGHT/SAT
MORNING...WHEREAS THE GFS BRINGS A DEEPER TROUGH THROUGH ON SATURDAY
EVENING. BY THIS TIME...THE ECMWF HAS ZONAL FLOW ALOFT FOR UPPER MI.
THE GEM SEEMS TO BE THE MIDDLE OF THE ROAD...BRINGING THE TROUGH
THROUGH THE GREAT LAKES SATURDAY AFTERNOON...WITH A STRENGTH SIMILAR
TO THAT OF THE ECMWF. BY SUNDAY AND MONDAY...THESE DIFFERENCES ARE
EXACERBATED...ESPECIALLY AT THE SURFACE. THE ECMWF KEEPS A WEAK SURFACE
TROUGH OVER THE GREAT LAKES THROUGH SUNDAY AFTERNOON...AND THEN
BRINGS A SURFACE HIGH ACROSS THE NORTHERN PLAINS INTO THE GREAT LAKES
FOR MONDAY. THE GFS BRINGS A CLOSED LOW PRESSURE SYSTEM ACROSS
MANITOBA AND INTO JAMES BAY...WHICH KEEPS A TROUGH OVER UPPER MI.
WILL KEEP THE CONSENSUS POPS FOR NOW GIVEN SUCH DRAMATIC DIFFERENCES.
ON A POSITIVE NOTE...MODELS TRENDING UPWARD WITH TEMPERATURES THROUGH
THE PERIOD...WITH HIGHS IN THE UPPER 20S AND LOW 30S BY NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1226 PM EST MON JAN 6 2014
EXTREMELY COLD AIR MASS MOVING ACROSS THE UPPER GREAT LAKES WILL
CONTINUE TO GENERATE LAKE EFFECT SNOW SHOWERS OFF LAKE SUPERIOR.
WITH WNW FLOW...KCMX/KIWD WILL BE IMPACTED BY SNOW SHOWERS...MOST
SIGNIFICANTLY AT KCMX. COMBINATION OF FALLING AND BLOWING OF THE
SMALL SNOWFLAKES AT THESE LOCATIONS WILL RESULT IN PREVAILING IFR
CONDITIONS AT KIWD AND LIFR AT KCMX. WITH KCMX MORE EXPOSED IN A WNW
WIND AND WITH BOUNDARY LAYER WINDS INCREASING...VLIFR CONDITIONS
WILL BECOME THE RULE AT KCMX THIS EVENING...IF NOT BEFORE...AND THAT
WILL CONTINUE THRU TUE MORNING. SOME IMPROVEMENT WILL BEGIN AT KIWD
TUE MORNING AND PERHAPS AT KCMX NEAR THE END OF THIS FCST PERIOD AS
WINDS DIMINISH SLOWLY AND DEEPER MOISTURE DEPARTS/INVERSIONS FALL...
RESULTING IN DIMINISHING LAKE EFFECT SNOW SHOWERS. THOUGH SOME
PERIODS OF HIGH MVFR CIGS WILL OCCUR THIS AFTN...EXPECT VFR
CONDITIONS TO PREDOMINATE AT KSAW WITH A DOWNSLOPE WNW WIND
COMPONENT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST MON JAN 6 2014
WITH SHARPENING PRES GRADIENT AND FLOW OF ARCTIC AIR OVER THE
RELATIVELY WARM LK WATERS...EXPECT WNW WINDS 30 KTS TO GALES TO 35
KTS THRU TONIGHT INTO TUESDAY EVENING. MAINTAINED GOING GALE
WARNINGS. THE COMBINATION OF THE BITTER COLD/SIGNIFICANT WAVE ACTION
WILL RESULT IN WIDESPREAD HEAVY FREEZING SPRAY AS WELL...SO LEFT THE
HEAVY FREEZING SPRAY WARNINGS IN EFFECT THROUGH WEDNESDAY MORNING.
OTHERWISE...HIGH PRESSURE WILL MAKE ITS WAY SOUTH OF LAKE SUPERIOR
BY MID WEEK...BUT A PERSISTANT LOW PRESSURE TROUGH NORTH OF THE LAKE
WILL KEEP WNW WINDS GUSTING TO 15 TO 25 KTS THROUGH THURSDAY.
TOWARDS THE LATTER PORTION OF THE WEEK...ANOTHER LOW PRESSURE TROUGH
WILL APPROACH THE GREAT LAKES FROM THE NORTHERN PLAINS...BACKING
WINDS TO THE SOUTHWEST AT 15 TO 25 KNOTS FOR THURSDAY AND FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 11 AM EST /10 AM CST/ TUESDAY FOR
MIZ001>005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ014-
085.
WIND CHILL WARNING FROM 7 PM THIS EVENING TO 11 AM EST TUESDAY
FOR MIZ006-007-014-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ001>003-
006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MCD
AVIATION...ROLFSON
MARINE...KC/MCD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
642 AM EST MON JAN 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST MON JAN 6 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF IN
CENTRAL NAMERICA AS ARCTIC/POLAR BRANCHES ARE IN THE PROCESS OF
PHASING...WITH THE AXIS OF LOWEST HGTS STRETCHING FM HUDSON BAY INTO
THE UPR MS RIVER VALLEY. WITHIN THE CORE OF THE COLDEST AIR...00Z
RAOBS SHOW H5/H85/H925 TEMPS AS LO AS -45C/-34C/-34C. THE PHASING OF
THE UPR BRANCHES IS SUPPORTING A DEEPENING SFC LO MOVING NNEWD INTO
SE ONTARIO. ALTHOUGH THE SYNOPTIC SCALE FORCING/PCPN ASSOCIATED WITH
THIS SFC LO ARE PASSING TO THE E OF UPR MI...SHARPENING CYC NNW FLOW
ON THE NW FLANK OF THE LO AND AREA OF DPVA/DEEP LYR QVECTOR CNVGC/
DEEPENING MID LVL MSTR AHEAD OF THE ARCTIC BRANCH SHRTWV ARE
IMPACTING MAINLY THE E HALF OF UPR MI...CAUSING AN INCRS IN LES
INTENSITY/COVERAGE IN THE FAVORED SN BELTS. AN AREA OF DEEPER MSTR
ALSO STRECHES FM NW ONTARIO S INTO MN UNDER THE AXIS OF LOWER HGTS.
TEMPS REMAIN WELL BLO NORMAL. 00Z H85 TEMPS OVER UPR MI RANGED FM
ABOUT -19C OVER THE SE TO -25C OVER THE W... SUPPORTING SFC TEMPS AS
LO AS -20F OVER THE FAR W NEAR THE WI BORDER EARLY THIS MRNG. THE
MORE NNW FLOW OFF LK SUP HAS MODERATED THE AIRMASS DOWNWIND OF THE
LK OVER THE ERN CWA...WHERE TEMPS NEAR LK SUP REMAIN CLOSE TO 10F.
THE INCRSG WINDS HAVE CAUSED WIND CHILLS TO FALL AS LO AS -35 TO
-40F OVER THE WRN CWA.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON HEADLINES RELATED TO
TEMPS/WIND CHILLS AS WELL AS LES/BLSN.
TDAY...SFC LO OVER SE ONTARIO EARLY THIS MRNG IS PROGGED TO LIFT
NEWD INTO QUEBEC AND INTENSIFY AS AXIS OF LOWEST HGTS ALF DRIFTS E
ACROSS THE UPR LKS. ALTHOUGH THE AREA OF SHARPER QVECTOR CNVGC TO
THE E OF THE UPR TROF IS PROGGED TO DRIFT TO THE E AND AWAY FM
NEWBERRY BY LATE AFTN...AREA OF DEEPER MSTR/CORE OF COLDER AIR NOTED
TO THE W IS PROGGED TO DRIFT E THRU THE UPR LKS AS WELL. THE COLDEST
H85 TEMPS ARE FCST TO PASS TO THE S THRU WI...BUT THE STEADILY
BACKING LLVL FLOW TOWARD THE W BY 00Z TUE ASSOCIATED WITH THE
DEPARTING SFC LO TO THE NE WL ALLOW FOR LESS LK SUP MODERATION OF
THE BITTERLY COLD AIRMASS. THE FOCUS OF THE HIER LES POPS WL SHIFT
AS WELL WITH THESE BACKING WINDS. ALTHOUGH ABSENCE OF DGZ WITH
BITTERLY COLD AIR WL LIMIT SN ACCUMS OVER THE W...ARRIVAL OF DEEPER
MSTR WL KEEP CONTINUOUS -SHSN GOING. SMALL SN FLAKES WL EFFICIENTLY
REDUCE VSBY AS BLSN INCREASES WITH SLOWLY INCRSG WINDS. EXPECT
SOMEWHAT HEAVIER SHSN OVER THE E WHERE LES ADVY IS IN PLACE GIVEN
SOME LINGERING DYNAMIC FORCING/WARMER AIR THAT DOES NOT HAMPER SN
GROWTH AS MUCH... BUT THE SHIFTING WINDS WL TEND TO CAUSE THE LES
BANDS TO DRIFT AS WELL. AS FOR TEMPS/WIND CHILLS...EXPECT LTL IF ANY
DIURNAL RECOVERY WITH BACKING LLVL FLOW LIMITING LK MODERATION. OVER
THE E...THIS BACKING FLOW MAY CAUSE TEMPS TO FALL. SINCE WIND SPEEDS
WL BE ON THE INCRS AS WELL...GOING WIND CHILL HEADLINES SEEM TO BE
ON TRACK.
TNGT...MODELS HINT ANOTHER SHRTWV DIVING SEWD ARND SLOWLY DEPARTING
UPR TROF AXIS WL MOVE INTO THE UPR LKS...BRINGING ANOTHER ROUND OF
DPVA/DEEP LYR QVECTOR CNVGC THAT MAINTAINS DEEPER MSTR. AS THE SFC
FLOW BACKS WITH LAND BREEZE ENHANCEMENT...LLVL CNVGC WL INCRS OVER
NRN ONTONAGON/CENTRAL HOUGHTON COUNTIES AND NEAR LK SUP E OF
MUNISING. THIS INCRSG LAND BREEZE COMPONENT WL TEND TO ADVECT LESS
MODIFIED AIR INTO THE CWA AND OFFSET SLOWLY MODERATING H85 TEMPS
WITH PASSAGE OF COLDEST CORE TO THE E. SINCE THE LLVL WINDS ARE FCST
TO INCRS AS WELL...WARNING THRESHOLD WIND CHILLS ARE LIKELY OVER
ALMOST ALL OF THE CWA.
AS FOR HEADLINES...GOING WIND CHILL WARNINGS APPEAR TO BE ON TRACK
EVEN THOUGH MORE LK MODIFIED AIR HAS MAINTAINED HIER TEMPS OVER
ABOUT THE E HALF OF THE CWA. BACKING/INCRSG WINDS LATER TDAY/TNGT
SHOULD ADVECT SUFFICIENTLY COLD AIR OVER THE ENTIRE CWA TO JUSTIFY
MAINTAINING ALL WIND CHILL WRNGS. ALTHOUGH SN AMOUNTS OVER THE W ARE
NOT LIKELY TO REACH ADVY THRESHOLDS...OPTED TO ISSUE AN LES ADVY FOR
ONTONAGON COUNTY THRU THE KEWEENAW THRU TUE TO ACCOUNT FOR THE
FREQUENT WHITEOUTS THAT WL LIKELY OCCUR WITH THE FALLING AND BLOWING
OF THE SMALL SN FLAKES. EXTENDED THE LES ADVY FOR ALGER/LUCE
COUNTIES THRU TUE AS WELL GIVEN THE POTENTIAL FOR HEAVIER SHSN
ESPCIALLY NEAR LK SUP E OF PICTURED ROCKS IN THE SHARPER LLVL CNVGC
THAT WL DVLP WITH SHARPENING LAND BREEZE CNVGC/WARMER H85 TEMPS THAT
WL NOT IMPACT SN GROWTH AS MUCH AS OVER THE W.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 448 AM EST MON JAN 6 2014
THE 500MB LOW RESPONSIBLE FOR THE ACTIVE WEATHER ACROSS THE GREAT
LAKES THIS WEEK WILL BE OVER QUEBEC TUESDAY MORNING. THIS LOW WILL
LINGER A TROUGH OVER THE GREAT LAKES THROUGH THE DAY TUESDAY AND
WEDNESDAY. AT THE SURFACE...HIGH PRESSURE WILL SINK TOWARDS THE GULF
OF MEXICO. THE SURFACE LOW OVER THE LOWER LAKES MONDAY NIGHT WILL
MAKE ITS WAY INTO QUEBEC BY TUESDAY...KEEPING A WEAK TROUGH OVER
EASTERN LAKE SUPERIOR THROUGH WEDNESDAY. OVERALL...UPPER MI WILL
REMAIN IN WEST-NORTHWEST FLOW THROUGH THE FIRST PORTION OF THE LONG
TERM...CAUGHT BETWEEN THE HIGH IN THE SOUTHEAST AND THE LOW IN
QUEBEC. THOUGH WINDS WILL BE GUSTY THROUGH MOST OF TUESDAY...THEY
WILL GRADUALLY LESSEN AS THE HIGH MAKES ITS WAY INTO THE CWA TUESDAY
NIGHT INTO WEDNESDAY. WITH THE COLD ARCTIC AIR IN PLACE...LES WILL
CONTINUE IN WNW-WIND FAVORED SNOWBELTS. WITH DWINDLING
MOISTURE/EXTREME COLD...SNOW RATIOS WILL BE UNSUPPORTIVE OF
SIGNIFICANT ACCUMULATIONS ACROSS THE AREA FOR THIS TIME PERIOD. FOR
NOW HAVE 2 TO 4 INCHES OF ACCUMULATION FROM TUESDAY MORNING INTO
WEDNESDAY MORNING FOR EASTERN ALGER/LUCE COUNTY...AND 1 TO 2 INCHES
ACROSS ONTONAGON...HOUGHTON...AND KEWEENAW COUNTY.
THE MAIN CONCERN WILL BE LOWERED VISIBILITY DUE TO THE SMALL FLAKE
SIZE AND BLOWING SNOW/FROM GUSTY WNW WINDS/ NEAR THE LAKESHORE ALL
DAY TUESDAY...AND WIND CHILLS THROUGH LATE TUESDAY MORNING. FOR
HEADLINES...HAVE LES ADVISORY THROUGH TUESDAY IN WNW WIND FAVORED
SNOWBELTS...MAINLY ONTONAGON....NORTHERN
HOUGHTON...KEWEENAW...ALGER...AND LUCE COUNTIES TO ACCOUNT FOR THE
SNOW/BLOWING SNOW/WIND CHILL. ELSEWHERE...SOLELY THE WIND CHILL
WARNING REMAINS IN EFFECT. WIND CHILLS TUESDAY MORNING WILL RANGE
FROM -50F TO -25F ACROSS THE FORECAST AREA...WITH THE COLDEST
READINGS ACROSS THE INTERIOR WEST.
THE HIGH WILL GRADUALLY CROSS THE GREAT LAKES LATE WEDNESDAY INTO
THURSDAY...AND THEN REACH THE NEW ENGLAND STATES BY THURSDAY NIGHT.
AS THE HIGH MOVES OUT...WINDS BACK TO THE SOUTHWEST. THIS BRINGS
EXTREMELY DRY AIR INTO MUCH OF THE CWA BY EARLY WEDNESDAY
EVENING...STARTING A DISSIPATING TREND TO THE LES THROUGH THURSDAY
MORNING. ADDITIONALLY...WITH WINDS BACKING SOUTHWEST...MOST OF THE
REMAINING LES WILL MOVE OFFSHORE INTO LAKE SUPERIOR. THE BEST CHANCE
FOR SNOW SHOWERS ON THURSDAY IS OVER THE KEWEENAW.
MODELS BEGIN TO DISAGREE LATE THURSDAY INTO FRIDAY ON HOW TO HANDLE
AN UPPER LEVEL TROUGH MOVING INTO THE NORTHERN PLAINS...BOTH WITH
THE TIME AND STRENGTH OF THE OVERALL FEATURE. THE ECMWF BRINGS A
MORE SHALLOW TROUGH ACROSS THE GREAT LAKES FRIDAY NIGHT/SAT
MORNING...WHEREAS THE GFS BRINGS A DEEPER TROUGH THROUGH ON SATURDAY
EVENING. BY THIS TIME...THE ECMWF HAS ZONAL FLOW ALOFT FOR UPPER MI.
THE GEM SEEMS TO BE THE MIDDLE OF THE ROAD...BRINGING THE TROUGH
THROUGH THE GREAT LAKES SATURDAY AFTERNOON...WITH A STRENGTH SIMILAR
TO THAT OF THE ECMWF. BY SUNDAY AND MONDAY...THESE DIFFERENCES ARE
EXACERBATED...ESPECIALLY AT THE SURFACE. THE ECMWF KEEPS A WEAK SURFACE
TROUGH OVER THE GREAT LAKES THROUGH SUNDAY AFTERNOON...AND THEN
BRINGS A SURFACE HIGH ACROSS THE NORTHERN PLAINS INTO THE GREAT LAKES
FOR MONDAY. THE GFS BRINGS A CLOSED LOW PRESSURE SYSTEM ACROSS
MANITOBA AND INTO JAMES BAY...WHICH KEEPS A TROUGH OVER UPPER MI.
WILL KEEP THE CONSENSUS POPS FOR NOW GIVEN SUCH DRAMATIC DIFFERENCES.
ON A POSITIVE NOTE...MODELS TRENDING UPWARD WITH TEMPERATURES THROUGH
THE PERIOD...WITH HIGHS IN THE UPPER 20S AND LOW 30S BY NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 641 AM EST MON JAN 6 2014
EXTREME COLD AIRMASS MOVING ACROSS THE UPPER GREAT LAKES WILL ALLOW
FOR LAKE EFFECT SNOW SHOWERS TO CONTINUE THROUGH THE PERIOD AT CMX
AND IWD. THE COMBINATION OF FALLING AND BLOWING OF THE SMALL SN
FLAKES AT THESE LOCATIONS WL RESULT IN IFR WX. THE WORST CONDITIONS
WL BE AT THE MORE EXPOSED CMX LOCATION TNGT...WHERE VLIFR CONDITIONS
WL BE THE RULE WITH INCRSG WNW WINDS. EXPECT VFR CONDITIONS TO
PREDOMINATE AT SAW WITH A DOWNSLOPE WNW WIND COMPONENT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST MON JAN 6 2014
WITH SHARPENING PRES GRADIENT AND FLOW OF ARCTIC AIR OVER THE
RELATIVELY WARM LK WATERS...EXPECT WNW WINDS 30 KTS TO GALES TO 35
KTS THRU TONIGHT INTO TUESDAY EVENING. MAINTAINED GOING GALE
WARNINGS. THE COMBINATION OF THE BITTER COLD/SIGNIFICANT WAVE ACTION
WILL RESULT IN WIDESPREAD HEAVY FREEZING SPRAY AS WELL...SO LEFT THE
HEAVY FREEZING SPRAY WARNINGS IN EFFECT THROUGH WEDNESDAY MORNING.
OTHERWISE...HIGH PRESSURE WILL MAKE ITS WAY SOUTH OF LAKE SUPERIOR
BY MID WEEK...BUT A PERSISTANT LOW PRESSURE TROUGH NORTH OF THE LAKE
WILL KEEP WNW WINDS GUSTING TO 15 TO 25 KTS THROUGH THURSDAY.
TOWARDS THE LATTER PORTION OF THE WEEK...ANOTHER LOW PRESSURE TROUGH
WILL APPROACH THE GREAT LAKES FROM THE NORTHERN PLAINS...BACKING
WINDS TO THE SOUTHWEST AT 15 TO 25 KNOTS FOR THURSDAY AND FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 11 AM EST /10 AM CST/ TUESDAY FOR
MIZ001>005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ014-
085.
WIND CHILL WARNING FROM 7 PM THIS EVENING TO 11 AM EST TUESDAY
FOR MIZ006-007-014-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ001>003-
006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MCD
AVIATION...KC
MARINE...KC/MCD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
452 AM EST MON JAN 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST MON JAN 6 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF IN
CENTRAL NAMERICA AS ARCTIC/POLAR BRANCHES ARE IN THE PROCESS OF
PHASING...WITH THE AXIS OF LOWEST HGTS STRETCHING FM HUDSON BAY INTO
THE UPR MS RIVER VALLEY. WITHIN THE CORE OF THE COLDEST AIR...00Z
RAOBS SHOW H5/H85/H925 TEMPS AS LO AS -45C/-34C/-34C. THE PHASING OF
THE UPR BRANCHES IS SUPPORTING A DEEPENING SFC LO MOVING NNEWD INTO
SE ONTARIO. ALTHOUGH THE SYNOPTIC SCALE FORCING/PCPN ASSOCIATED WITH
THIS SFC LO ARE PASSING TO THE E OF UPR MI...SHARPENING CYC NNW FLOW
ON THE NW FLANK OF THE LO AND AREA OF DPVA/DEEP LYR QVECTOR CNVGC/
DEEPENING MID LVL MSTR AHEAD OF THE ARCTIC BRANCH SHRTWV ARE
IMPACTING MAINLY THE E HALF OF UPR MI...CAUSING AN INCRS IN LES
INTENSITY/COVERAGE IN THE FAVORED SN BELTS. AN AREA OF DEEPER MSTR
ALSO STRECHES FM NW ONTARIO S INTO MN UNDER THE AXIS OF LOWER HGTS.
TEMPS REMAIN WELL BLO NORMAL. 00Z H85 TEMPS OVER UPR MI RANGED FM
ABOUT -19C OVER THE SE TO -25C OVER THE W... SUPPORTING SFC TEMPS AS
LO AS -20F OVER THE FAR W NEAR THE WI BORDER EARLY THIS MRNG. THE
MORE NNW FLOW OFF LK SUP HAS MODERATED THE AIRMASS DOWNWIND OF THE
LK OVER THE ERN CWA...WHERE TEMPS NEAR LK SUP REMAIN CLOSE TO 10F.
THE INCRSG WINDS HAVE CAUSED WIND CHILLS TO FALL AS LO AS -35 TO
-40F OVER THE WRN CWA.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON HEADLINES RELATED TO
TEMPS/WIND CHILLS AS WELL AS LES/BLSN.
TDAY...SFC LO OVER SE ONTARIO EARLY THIS MRNG IS PROGGED TO LIFT
NEWD INTO QUEBEC AND INTENSIFY AS AXIS OF LOWEST HGTS ALF DRIFTS E
ACROSS THE UPR LKS. ALTHOUGH THE AREA OF SHARPER QVECTOR CNVGC TO
THE E OF THE UPR TROF IS PROGGED TO DRIFT TO THE E AND AWAY FM
NEWBERRY BY LATE AFTN...AREA OF DEEPER MSTR/CORE OF COLDER AIR NOTED
TO THE W IS PROGGED TO DRIFT E THRU THE UPR LKS AS WELL. THE COLDEST
H85 TEMPS ARE FCST TO PASS TO THE S THRU WI...BUT THE STEADILY
BACKING LLVL FLOW TOWARD THE W BY 00Z TUE ASSOCIATED WITH THE
DEPARTING SFC LO TO THE NE WL ALLOW FOR LESS LK SUP MODERATION OF
THE BITTERLY COLD AIRMASS. THE FOCUS OF THE HIER LES POPS WL SHIFT
AS WELL WITH THESE BACKING WINDS. ALTHOUGH ABSENCE OF DGZ WITH
BITTERLY COLD AIR WL LIMIT SN ACCUMS OVER THE W...ARRIVAL OF DEEPER
MSTR WL KEEP CONTINUOUS -SHSN GOING. SMALL SN FLAKES WL EFFICIENTLY
REDUCE VSBY AS BLSN INCREASES WITH SLOWLY INCRSG WINDS. EXPECT
SOMEWHAT HEAVIER SHSN OVER THE E WHERE LES ADVY IS IN PLACE GIVEN
SOME LINGERING DYNAMIC FORCING/WARMER AIR THAT DOES NOT HAMPER SN
GROWTH AS MUCH... BUT THE SHIFTING WINDS WL TEND TO CAUSE THE LES
BANDS TO DRIFT AS WELL. AS FOR TEMPS/WIND CHILLS...EXPECT LTL IF ANY
DIURNAL RECOVERY WITH BACKING LLVL FLOW LIMITING LK MODERATION. OVER
THE E...THIS BACKING FLOW MAY CAUSE TEMPS TO FALL. SINCE WIND SPEEDS
WL BE ON THE INCRS AS WELL...GOING WIND CHILL HEADLINES SEEM TO BE
ON TRACK.
TNGT...MODELS HINT ANOTHER SHRTWV DIVING SEWD ARND SLOWLY DEPARTING
UPR TROF AXIS WL MOVE INTO THE UPR LKS...BRINGING ANOTHER ROUND OF
DPVA/DEEP LYR QVECTOR CNVGC THAT MAINTAINS DEEPER MSTR. AS THE SFC
FLOW BACKS WITH LAND BREEZE ENHANCEMENT...LLVL CNVGC WL INCRS OVER
NRN ONTONAGON/CENTRAL HOUGHTON COUNTIES AND NEAR LK SUP E OF
MUNISING. THIS INCRSG LAND BREEZE COMPONENT WL TEND TO ADVECT LESS
MODIFIED AIR INTO THE CWA AND OFFSET SLOWLY MODERATING H85 TEMPS
WITH PASSAGE OF COLDEST CORE TO THE E. SINCE THE LLVL WINDS ARE FCST
TO INCRS AS WELL...WARNING THRESHOLD WIND CHILLS ARE LIKELY OVER
ALMOST ALL OF THE CWA.
AS FOR HEADLINES...GOING WIND CHILL WARNINGS APPEAR TO BE ON TRACK
EVEN THOUGH MORE LK MODIFIED AIR HAS MAINTAINED HIER TEMPS OVER
ABOUT THE E HALF OF THE CWA. BACKING/INCRSG WINDS LATER TDAY/TNGT
SHOULD ADVECT SUFFICIENTLY COLD AIR OVER THE ENTIRE CWA TO JUSTIFY
MAINTAINING ALL WIND CHILL WRNGS. ALTHOUGH SN AMOUNTS OVER THE W ARE
NOT LIKELY TO REACH ADVY THRESHOLDS...OPTED TO ISSUE AN LES ADVY FOR
ONTONAGON COUNTY THRU THE KEWEENAW THRU TUE TO ACCOUNT FOR THE
FREQUENT WHITEOUTS THAT WL LIKELY OCCUR WITH THE FALLING AND BLOWING
OF THE SMALL SN FLAKES. EXTENDED THE LES ADVY FOR ALGER/LUCE
COUNTIES THRU TUE AS WELL GIVEN THE POTENTIAL FOR HEAVIER SHSN
ESPCIALLY NEAR LK SUP E OF PICTURED ROCKS IN THE SHARPER LLVL CNVGC
THAT WL DVLP WITH SHARPENING LAND BREEZE CNVGC/WARMER H85 TEMPS THAT
WL NOT IMPACT SN GROWTH AS MUCH AS OVER THE W.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 448 AM EST MON JAN 6 2014
THE 500MB LOW RESPONSIBLE FOR THE ACTIVE WEATHER ACROSS THE GREAT
LAKES THIS WEEK WILL BE OVER QUEBEC TUESDAY MORNING. THIS LOW WILL
LINGER A TROUGH OVER THE GREAT LAKES THROUGH THE DAY TUESDAY AND
WEDNESDAY. AT THE SURFACE...HIGH PRESSURE WILL SINK TOWARDS THE GULF
OF MEXICO. THE SURFACE LOW OVER THE LOWER LAKES MONDAY NIGHT WILL
MAKE ITS WAY INTO QUEBEC BY TUESDAY...KEEPING A WEAK TROUGH OVER
EASTERN LAKE SUPERIOR THROUGH WEDNESDAY. OVERALL...UPPER MI WILL
REMAIN IN WEST-NORTHWEST FLOW THROUGH THE FIRST PORTION OF THE LONG
TERM...CAUGHT BETWEEN THE HIGH IN THE SOUTHEAST AND THE LOW IN
QUEBEC. THOUGH WINDS WILL BE GUSTY THROUGH MOST OF TUESDAY...THEY
WILL GRADUALLY LESSEN AS THE HIGH MAKES ITS WAY INTO THE CWA TUESDAY
NIGHT INTO WEDNESDAY. WITH THE COLD ARCTIC AIR IN PLACE...LES WILL
CONTINUE IN WNW-WIND FAVORED SNOWBELTS. WITH DWINDLING
MOISTURE/EXTREME COLD...SNOW RATIOS WILL BE UNSUPPORTIVE OF
SIGNIFICANT ACCUMULATIONS ACROSS THE AREA FOR THIS TIME PERIOD. FOR
NOW HAVE 2 TO 4 INCHES OF ACCUMULATION FROM TUESDAY MORNING INTO
WEDNESDAY MORNING FOR EASTERN ALGER/LUCE COUNTY...AND 1 TO 2 INCHES
ACROSS ONTONAGON...HOUGHTON...AND KEWEENAW COUNTY.
THE MAIN CONCERN WILL BE LOWERED VISIBILITY DUE TO THE SMALL FLAKE
SIZE AND BLOWING SNOW/FROM GUSTY WNW WINDS/ NEAR THE LAKESHORE ALL
DAY TUESDAY...AND WIND CHILLS THROUGH LATE TUESDAY MORNING. FOR
HEADLINES...HAVE LES ADVISORY THROUGH TUESDAY IN WNW WIND FAVORED
SNOWBELTS...MAINLY ONTONAGON....NORTHERN
HOUGHTON...KEWEENAW...ALGER...AND LUCE COUNTIES TO ACCOUNT FOR THE
SNOW/BLOWING SNOW/WIND CHILL. ELSEWHERE...SOLELY THE WIND CHILL
WARNING REMAINS IN EFFECT. WIND CHILLS TUESDAY MORNING WILL RANGE
FROM -50F TO -25F ACROSS THE FORECAST AREA...WITH THE COLDEST
READINGS ACROSS THE INTERIOR WEST.
THE HIGH WILL GRADUALLY CROSS THE GREAT LAKES LATE WEDNESDAY INTO
THURSDAY...AND THEN REACH THE NEW ENGLAND STATES BY THURSDAY NIGHT.
AS THE HIGH MOVES OUT...WINDS BACK TO THE SOUTHWEST. THIS BRINGS
EXTREMELY DRY AIR INTO MUCH OF THE CWA BY EARLY WEDNESDAY
EVENING...STARTING A DISSIPATING TREND TO THE LES THROUGH THURSDAY
MORNING. ADDITIONALLY...WITH WINDS BACKING SOUTHWEST...MOST OF THE
REMAINING LES WILL MOVE OFFSHORE INTO LAKE SUPERIOR. THE BEST CHANCE
FOR SNOW SHOWERS ON THURSDAY IS OVER THE KEWEENAW.
MODELS BEGIN TO DISAGREE LATE THURSDAY INTO FRIDAY ON HOW TO HANDLE
AN UPPER LEVEL TROUGH MOVING INTO THE NORTHERN PLAINS...BOTH WITH
THE TIME AND STRENGTH OF THE OVERALL FEATURE. THE ECMWF BRINGS A
MORE SHALLOW TROUGH ACROSS THE GREAT LAKES FRIDAY NIGHT/SAT
MORNING...WHEREAS THE GFS BRINGS A DEEPER TROUGH THROUGH ON SATURDAY
EVENING. BY THIS TIME...THE ECMWF HAS ZONAL FLOW ALOFT FOR UPPER MI.
THE GEM SEEMS TO BE THE MIDDLE OF THE ROAD...BRINGING THE TROUGH
THROUGH THE GREAT LAKES SATURDAY AFTERNOON...WITH A STRENGTH SIMILAR
TO THAT OF THE ECMWF. BY SUNDAY AND MONDAY...THESE DIFFERENCES ARE
EXACERBATED...ESPECIALLY AT THE SURFACE. THE ECMWF KEEPS A WEAK SURFACE
TROUGH OVER THE GREAT LAKES THROUGH SUNDAY AFTERNOON...AND THEN
BRINGS A SURFACE HIGH ACROSS THE NORTHERN PLAINS INTO THE GREAT LAKES
FOR MONDAY. THE GFS BRINGS A CLOSED LOW PRESSURE SYSTEM ACROSS
MANITOBA AND INTO JAMES BAY...WHICH KEEPS A TROUGH OVER UPPER MI.
WILL KEEP THE CONSENSUS POPS FOR NOW GIVEN SUCH DRAMATIC DIFFERENCES.
ON A POSITIVE NOTE...MODELS TRENDING UPWARD WITH TEMPERATURES THROUGH
THE PERIOD...WITH HIGHS IN THE UPPER 20S AND LOW 30S BY NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1234 AM EST MON JAN 6 2014
EXTREME COLD AIRMASS MOVING ACROSS THE UPPER GREAT LAKES WILL ALLOW
FOR LAKE EFFECT SNOW SHOWERS TO CONTINUE THROUGH THE PERIOD. KCMX
WILL LIKELY SEE LIGHT SNOW THROUGH THE PERIOD. DUE TO THE FINE SNOW
FLAKES AND BLOWING SNOW UNDER THE ARCTIC AIRMASS...EXPECT CONDITIONS
TO REMAIN IFR TONIGHT...THEN DETERIORATE INTO LIFR CONDITIONS ON
MONDAY AS THE FLOW BECOMES MORE WESTERLY AND THE POLAR VORTEX MOVES
OVERHEAD. KIWD WILL ALSO SEE FAIRLY PERSISTENT LIGHT SNOW AND BLSN
TONIGHT WITH IFR VSBYS. HOWEVER...AS THE FLOW BECOMES MORE WESTERLY
ON MONDAY EXPECT THE SNOW TO DIMINISH AND VSBYS TO IMPROVE BY MON
EVENING. AT KSAW...SOME LIGHT SNOW/FLURRIES TONIGHT INTO MONDAY
MORNING WILL LIKELY YIELD MVFR CONDITIONS...BUT THE EXPECTATION IS
THAT WHEN THE SURFACE FLOW BECOMES MORE W-NW ON MONDAY THAT VFR
CONDITIONS WILL DEVELOP.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST MON JAN 6 2014
WITH SHARPENING PRES GRADIENT AND FLOW OF ARCTIC AIR OVER THE
RELATIVELY WARM LK WATERS...EXPECT WNW WINDS 30 KTS TO GALES TO 35
KTS THRU TONIGHT INTO TUESDAY EVENING. MAINTAINED GOING GALE
WARNINGS. THE COMBINATION OF THE BITTER COLD/SIGNIFICANT WAVE ACTION
WILL RESULT IN WIDESPREAD HEAVY FREEZING SPRAY AS WELL...SO LEFT THE
HEAVY FREEZING SPRAY WARNINGS IN EFFECT THROUGH WEDNESDAY MORNING.
OTHERWISE...HIGH PRESSURE WILL MAKE ITS WAY SOUTH OF LAKE SUPERIOR
BY MID WEEK...BUT A PERSISTANT LOW PRESSURE TROUGH NORTH OF THE LAKE
WILL KEEP WNW WINDS GUSTING TO 15 TO 25 KTS THROUGH THURSDAY.
TOWARDS THE LATTER PORTION OF THE WEEK...ANOTHER LOW PRESSURE TROUGH
WILL APPROACH THE GREAT LAKES FROM THE NORTHERN PLAINS...BACKING
WINDS TO THE SOUTHWEST AT 15 TO 25 KNOTS FOR THURSDAY AND FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 11 AM EST /10 AM CST/ TUESDAY FOR
MIZ001>005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ014-
085.
WIND CHILL WARNING FROM 7 PM THIS EVENING TO 11 AM EST TUESDAY
FOR MIZ006-007-014-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ001>003-
006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MCD
AVIATION...MRD
MARINE...KC/MCD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1242 AM EST MON JAN 6 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 445 PM EST SUN JAN 5 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE CENTER OF AN ELONGATED
POLAR VORTEX OVER NRN ONTARIO. A SHORTWAVE WAS DIVING SE THRU THE
NRN PLAINS...CAUSING THE ELONGATION OF THE VORTEX INTO THE NRN
PLAINS. THE CORE OF THE VERY COLD ARCTIC AIR MASS RESIDES FROM NRN
ONTARIO INTO SCNTRL CANADA AND THE FAR NRN PLAINS. PER 12Z RAOBS...
850MB TEMPS ARE IN THE -29C TO -34C RANGE ACROSS SCNTRL CANADA INTO
THE FAR NCNTL CONUS. LATEST RUC ANALYSIS INDICATES 850MB TEMPS
RANGING FROM -25C OVER WRN LAKE SUPERIOR TO AROUND -19C OVER FAR SE
LAKE SUPERIOR. OF COURSE...THIS IS LEADING TO LES OFF LAKE SUPERIOR
IN WNW LOW-LEVEL FLOW. HOWEVER...VERY DRY AIR MASS/LOW INVERSION
(3-5KFT LOWEST W PER LATEST RUC) IS GREATLY LIMITING LES INTENSITY.
PLUS...IT DOESN`T HELP THAT VERY COLD AIR HAS ELIMINATED THE DGZ FOR
THE WRN LAKE SUPERIOR LES. ON THE OTHER HAND...THE RESULTING SMALL
SNOWFLAKES ARE LEADING TO SHARPLY REDUCED VIS WHERE LES IS OCCURRING
(VIS AT KCMX HAS BEEN DOWN TO 1/2SM AT TIMES THIS AFTN...AND WEBCAMS
HAVE SHOWN QUITE LOW VIS AT TIMES).
AS THE ELONGATED POLAR VORTEX SWINGS INTO THE UPPER GREAT LAKES
MON...THERE WILL BE A SIGNIFICANT LIFTING OF THE INVERSION AND
DEEPENING OF MOISTURE. THIS WILL GRADUALLY BEGIN TONIGHT...BUT WILL
LARGELY TAKE PLACE DURING THE DAY MON. AS A RESULT...THERE WILL BE A
NOTABLE INCREASE IN LAKE EFFECT SNOW COVERAGE...AND INTENSITY WILL
INCREASE AS WELL. HOWEVER...WITH THE COLD AIR MASS ELIMINATING THE
DGZ...SNOW-TO-WATER RATIOS WILL BE POOR...PROBABLY DOWN TOWARD 10 TO
1 AS HAS BEEN OBSERVED IN PAST ARCTIC AIR MASSES SIMILAR TO THE
MAGNITUDE OF THIS ONE. SNOW WILL BE POWDERY AND VERY EFFECTIVE AT
REDUCING VIS. WITH THE INCREASE IN LES COVERAGE...WHITEOUTS WILL
PROBABLY BECOME NEARLY CONSTANT IN THE SNOWBELTS FAVORED BY NW WINDS
LATE TONIGHT AND ESPECIALLY MON. TONIGHT...LOW-LEVEL WINDS WILL
VEER MORE TOWARD THE NNW IN RESPONSE TO THE DEEPENING LOW LIFTING
NNE THRU THE LWR LAKES. THE VEERING WILL BE MORE PRONOUNCED OVER THE
ERN LAKE WHERE LAND BREEZE ENHANCEMENT OFF ONTARIO WILL AID THE
VEERING. THIS WILL LEAD TO STRENGTHENING CONVERGENCE INTO
ALGER/LUCE/SCHOOLCRAFT COUNTIES. WITH THE DGZ STILL LINGERING IN THE
LOWER PART OF THE CONVECTIVE LAYER IN THAT AREA...SHOULD BE ABLE TO
GET ACCUMULATIONS INTO THE 2 TO 4 INCH RANGE. COMBINED WITH SOME
INCREASE IN WINDS TO GENERATE BLSN...ADVY LOOKS ON TRACK FOR THAT
AREA. EVEN THOUGH THE DGZ IS ELIMINATED MON...SIMILAR ACCUMULATIONS
SHOULD OCCUR GIVEN LINGERING ENHANCED CONVERGENCE AND DEEP MOISTURE
PROFILE. OUT W...SNOW ACCUMULATIONS WILL BE ON THE ORDER OF 1-2 TO
PERHAPS 3IN/12HR TONIGHT/MON.
AS FOR TEMPS/WIND CHILLS...WITH LOW-LEVEL WINDS VEERING TONIGHT...
THERE SHOULD BE AN INCREASE IN LAKE EFFECT CLOUD COVER ACROSS MUCH
OF THE AREA. HAVE THUS OPTED TO RAISE MINS A FEW DEGREES IN MANY
LOCATIONS. TEMPS MAY STILL BOTTOM OUT AROUND -25F OVER THE FAR W
ALONG THE MI/WI BORDER...BUT IF CLOUD COVER IS QUICKER TO DEVELOP
AND MORE PERSISTENT...TEMPS MAY NOT FALL THAT LOW. IN GENERAL...MOST
OF THE W HALF OF UPPER MI WILL SEE MINS IN THE -10F TO -20F RANGE
WITH WIND CHILLS FALLING TO -30 TO -45F. WITH THE CORE OF THE COLD
OVER THE AREA MON...EXPECT INTERIOR W LOCATIONS TO FAIL TO RISE
ABOVE -10F. ONLY AREAS TO GET JUST ABOVE 0F WILL BE OVER THE E.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 PM EST SUN JAN 5 2014
.MONDAY NIGHT INTO TUESDAY...W TO WNW LOW LEVEL WINDS WILL CONTINUE
BETWEEN LOW PRES LIFTING NNE INTO HUDSON BAY AND ARCTIC HIGH PRES
BUILDING FROM THE NRN PLAINS TO THE UPPER MS VALLEY. 850 MB TEMPS
WILL GRADUALLY MODERATE FROM THE -25C TO -30C RANGE TO -17C TO -22C
FROM 00Z/TUE TO 00Z/WED. HOWEVER...SFC TEMPS WILL CLIMB ONLY
SLIGHTLY. WINDS WILL ALSO DIMINISH TO AROUND 10 MPH BY TUE MORNING.
HOWEVER...WITH TEMPS AGAIN FALLING INTO THE -12 TO -25 RANGE...WIND
CHILL VALUES OF -30 TO -45 WILL REMAIN IN THE WARNING CATEGORY OVER
MOST OF THE CWA. LES WILL PERSIST FOR THE KEWEENAW AND THE NE CWA(E
OF MUNISING). THE HIGHER RES MODELS SUGGEST THAT LOW LEVEL CONV OVER
THE WRN LAKE MAY BOOST SNOWFALL RATES INTO THE KEWEENAW(NEAR OR JUST
SOUTH OF HOUGHTON) AND NEAR THE PICTURED ROCKS AND GRAND MARAIS.
HOWEVER...WITH THE VERY COLD AIR AND NO DGZ AVAILABLE...SLR VALUES
WILL REMAIN LOW AND LIMIT SNOW ACCUMULATIONS TO THE 1 TO 3 INCH PER
12 HOUR WEST AND POSSIBLY 2 TO 4 INCHES EAST.
TUE NIGHT AND WED...WRLY FLOW LES WILL CONTINUE AS THE AIRMASS
MODERATES. WITH THE DGZ MOVING BACK CLOSER TO THE CONVECTIVE
LAYER...SLR VALUES WILL INCREASE. HOWEVER...THE VERY AIR UPSTREAM
WILL REMAIN UNFAVORABLE FOR MORE SIGNIFICANT LES. SO...SNOWFALL RATES
WILL GENERALLY REMAIN LIGHT...IN THE 1 TO 3 INCH RANGE...WITH THE
GREATEST AMOUNTS REMAINING OVER THE KEWEENAW AND ALONG THE SHORELINE
NEAR GRAND MARAIS. WIND CHILLS WILL ALSO NOT BE AS SEVERE AS WINDS
DIMINISH CLOSER TO 5 MPH INLAND AS TEMPS DROP INTO THE -10 TO -20
RANGE GIVING WIND CHILL VALUES FROM -20 TO -30.
THU-SUN...THE MODELS SHOW A TRANSITION TO A MORE ZONAL PATTERN WITH
SEPARATED NRN AND SRN STREAMS. AFTER BACKING WINDS TO SW WILL END THE
LES OVER THE KEWEENAW THU...MAINLY DRY WEATHER IS EXPECTED INTO THE
WEEKEND WITH MUCH MILDER CONDITIONS. HIGH TEMPS SHOULD CLIMB BACK
INTO THE UPPER 20S FRI AND TO AROUND 30 FOR THE WEEKEND. ALTHOUGH THE
00Z/05 ECMWF RUN SHOWED A MORE PHASED TROUGH BY SUN THAT BRINGS UP
ENOUGH WARM AIR AND MOISTURE FOR RAIN...THE 12Z/05 RUN FLIPPED BACK
TO A MORE SEPARATE NRN STREAM WITH THE SRN SHRTWV SLIDING INTO THE
LOWER MS VALLEY SIMILAR TO THE GFS/GEFS. HOWEVER...CONFIDENCE IN ANY
WEATHER DETAILS BEYOND THE MILDER AIR FOR THE WEEKEND REMAINS LOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1234 AM EST MON JAN 6 2014
EXTREME COLD AIRMASS MOVING ACROSS THE UPPER GREAT LAKES WILL ALLOW
FOR LAKE EFFECT SNOW SHOWERS TO CONTINUE THROUGH THE PERIOD. KCMX
WILL LIKELY SEE LIGHT SNOW THROUGH THE PERIOD. DUE TO THE FINE SNOW
FLAKES AND BLOWING SNOW UNDER THE ARCTIC AIRMASS...EXPECT CONDITIONS
TO REMAIN IFR TONIGHT...THEN DETERIORATE INTO LIFR CONDITIONS ON
MONDAY AS THE FLOW BECOMES MORE WESTERLY AND THE POLAR VORTEX MOVES
OVERHEAD. KIWD WILL ALSO SEE FAIRLY PERSISTENT LIGHT SNOW AND BLSN
TONIGHT WITH IFR VSBYS. HOWEVER...AS THE FLOW BECOMES MORE WESTERLY
ON MONDAY EXPECT THE SNOW TO DIMINISH AND VSBYS TO IMPROVE BY MON
EVENING. AT KSAW...SOME LIGHT SNOW/FLURRIES TONIGHT INTO MONDAY
MORNING WILL LIKELY YIELD MVFR CONDITIONS...BUT THE EXPECTATION IS
THAT WHEN THE SURFACE FLOW BECOMES MORE W-NW ON MONDAY THAT VFR
CONDITIONS WILL DEVELOP.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 PM EST SUN JAN 5 2014
PRES GRADIENT WILL SLOWLY INCREASE TONIGHT THRU MON...RESULTING IN
AN INCREASE IN WINDS. LOOKS LIKE 35KT GALES WILL DEVELOP OVER
PORTIONS OF ERN LAKE SUPERIOR LATE TONIGHT OR MON MORNING...AIDED BY
LAND BREEZE CONVERGENCE. AS PRES GRADIENT TIGHTENS A LITTLE MORE...
WILL NEED TO WATCH FOR AN EXPANSION OF GALES TO MORE OF CNTRL/ERN
LAKE SUPERIOR MON NIGHT/TUE. WITH VERY COLD AIR MASS OVER THE AREA
FOR THE NEXT COUPLE OF DAYS...WINDS/WAVES WILL LEAD TO HEAVY
FREEZING SPRAY OVER MUCH OF LAKE SUPERIOR. WINDS WILL DIMINISH
DURING THE MIDWEEK PERIOD AS THE COLD EASES AND HIGH PRES MOVES
ACROSS THE GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 11 AM EST /10 AM CST/ TUESDAY FOR
MIZ001>005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006-
007-014-085.
WIND CHILL WARNING FROM 7 PM THIS EVENING TO 11 AM EST TUESDAY
FOR MIZ006-007-014-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WARNING FROM 7 AM THIS MORNING TO 1 AM EST WEDNESDAY FOR
LSZ265-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
AVIATION...MRD
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1034 PM CST SUN JAN 5 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 305 PM CST SUN JAN 5 2014
NORTHWEST WINDS HAVE INCREASED SUBSTANTIALLY ACROSS WEST CENTRAL
THROUGH SOUTH CENTRAL MN THIS AFTERNOON WITH 20-25 KNOTS COMMON.
THIS IS OCCURRING AS THE CORE OF THE ARCTIC AIR ARRIVES ALONG WITH
THE PRESSURE GRADIENT TIGHTENING BETWEEN A LOW PRESSURE STORM SYSTEM
MOVING THROUGH THE OHIO VALLEY AND A 1053MB HIGH OVER MONTANA.
WEB CAMS ARE SHOWING BLOWING SNOW WITH 1 TO 2 MILE VISIBILITY IN
THE AFOREMENTIONED AREAS. THE BLOWING SNOW WILL CONTINUE THROUGH
THE EVENING ADDING ANOTHER ELEMENT OF DANGER TO THE ALREADY LOW
WINDS CHILLS OF -40 TO -45 CURRENTLY IN PLACE. SATELLITE IMAGERY
SHOWS SOME NICE CONVECTIVE ROLLS AS WELL IN THE MN RIVER VALLEY WITH
THE RAP INDICATING LOW LEVEL LAPSE RATES EXCEEDING 8 DEG C/KM.
LITTLE DEVIATION TO THE FORECAST LOWS/HIGHS FOR TONIGHT AND
MONDAY AS THE CORE OF THE ARCTIC VORTEX SWINGS THROUGH. MUCH OF
CENTRAL MN AND ALONG HIGHWAY 8 IN WEST CENTRAL WI EXPECTED TO
REACH -30 TO -35 WITH -25 TO -30 OVER THE REMAINDER OF THE FA.
HIGHS ON MONDAY PROGGED TO BE IN THE -13 TO -19 RANGE FROM SOUTH
TO NORTH. WIND CHILL VALUES OVERNIGHT AND MONDAY MORNING FROM -50
TO -65 WITH -40 TO -50 FOR MONDAY AFTERNOON.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM CST SUN JAN 5 2014
THE MAIN WX DISCUSSION IS THAT THE CORE OF THE COLDEST AIR WILL HAVE
MOVED OUT OF THE REGION BY MONDAY NIGHT WITH ONLY RESIDUAL AFFECTS
BASED ON WIND SPDS AND TEMPS STILL IN THE TEENS AND 20S BLW ZERO
THRU TUESDAY MORNING. AS HIGH PRESSURE MOVES OVERHEAD TUESDAY
NIGHT/WEDNESDAY...THE AFFECTS OF RADIATIONAL COOLING MAY AID IN SOME
LOWER TEMPS THAN CURRENTLY FORECAST. BASED ON CURRENT MODEL TRENDS
NEAR -20F IN THE NORTHERN CWA...TO THE SINGLE DIGITS BLW ZERO IN THE
SOUTHERN CWA SEEMS REASONABLE AT THIS TIME.
AFTER WEDNESDAY...THE JET STREAM WILL MOVE NORTH WITH A MORE ZONAL
FLOW DEVELOPING BY THE END OF THE WEEK. THIS WILL LEAD TO MUCH
WARMER TEMPS BY FRI/SAT/SUN WITH ABV NORMAL READINGS ALMOST LIKELY.
MODELS ARE STILL HAVING TROUBLE HANDLING THE SPLIT FLOW REGIME.
BASICALLY FOR OUR REGION IT MEANS THAT UNCERTAINTY EXISTS AS MODELS
ARE TRYING TO HOLD ONTO THE SOUTHERN JET AS THE MOST ACTIVE WX IN
THE NEXT 7 DAYS. CONFIDENCE WILL REMAIN LOW UNTIL MODELS HAVE A
BETTER HANDLE ON THE SOUTHERN JET STREAM STORM SYSTEM THAT WILL
AFFECT THE SOUTHERN U.S. NEXT WEEKEND. AS FOR OUR AREA...MAINLY DRY
WX WILL CONTINUE WITH A MUCH ANTICIPATED WARMING TREND AT LEAST IN
THE SHORT TERM AFTER WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1009 PM CST SUN JAN 5 2014
COLD CORE TROUGH CONTINUES TO WORK EAST ACROSS MINNESOTA THIS
EVENING. THE BACK EDGE OF THE H7 TROUGH MAY BE EXITING INTO WI
NOW...AND MAY BE ASSOCIATED WITH THE REDEVELOPMENT OF SOME LOWER
MID LEVEL CLOUDS THERE. FURTHER UPSTREAM...APPEARS ANOTHER SHORT
WAVE DROPPING ALMOST DIRECTLY SOUTH OVER NORTH DAKOTA PER WATER
VAPOR IMAGERY. SOME LAYERED CLOUDS TRYING TO DEVELOP AHEAD OF
THAT ACROSS NORTHWEST MN THIS EVENING. THIS MAY SPREAD SOUTHEAST
DURING THE NIGHT. WILL HAVE TO INCLUDE SOME CLOUD ACROSS MOST
TAFS. WILL TRY AND CONTINUE THE VFR TREND INTO THE EARLY MORNING
HOURS. THEN WITH THE ARCTIC AIRMASS IN PLACE...WE MAY STILL
DEVELOP SOME MVFR STRATUS IN IC/IF BUT CONFIDENCE IS LOW ON HOW
WIDESPREAD THIS WILL BECOME. WILL HAVE TO MONTIOR THIS FOR NEXT
TAF ISSUANCE. NORTHWEST WINDS WILL BE GUSTY THROUGH THE DAY...AND
DIMINISH AROUND 07.00Z WITH CONTINUATION VFR CONDITIONS.
KMSP...BACK EDGE OF ANOTHER SHOT OF CLOUDS EXITING INTO WISCONSIN
THIS EVENING. WILL HAVE TO WAIT UNTIL NEXT AREA MOVES IN FROM THE
NORTHWEST ASSOCIATED WITH NEXT SHORT WAVE. WILL CONTINUE VFR TREND
HOWEVER FOR NOW. MAY SEE SOME IC/IF CONDITIONS DEVELOP AROUND
SUNRISE...BUT CONFIDENCE IS LOW ON OVERALL COVERAGE OF THIS. GUSTY
NORTHWEST WINDS SHOULD DIMINISH LATE TONIGHT AND INCREASE INTO
MONDAY BEFORE RELAXING BY MONDAY EVENING. REMAINING VFR MONDAY
NIGHT.
/OUTLOOK FOR KMSP/
TUE...VFR. W WINDS 5-10 KT.
WED...VFR. WINDS NEAR CALM.
THU...VFR. WINDS SE-S 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR MNZ041>045-047>070-
073>078-082>085-091>093.
WI...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...RAH
LONG TERM...JLT
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1219 PM CST MON JAN 6 2014
.UPDATE...
HAVE CONVERTED WIND CHILL WARNINGS INTO WIND CHILL ADVISORIES FOR
MOST OF THE CWA BEGINNING AT NOON. WIND CHILLS HAVE BEEN SOLIDLY
IN THE 25 BELOW RANGE BY LATE MORNING...EXPECT FOR AREAS NORTHEAST
OF THE OMAHA METRO. TEMPERATURES WERE APPROACHING OR EXCEEDING ZERO
IN OUR SOUTHWEST ALREADY...AND EXPECT THOSE AREAS TO AT LEAST
REACH THE MIDDLE SINGLE DIGITS WITH WIND CHILLS 10 TO 15 BELOW.
ALSO EXPECT WINDS TO REALLY DIE DOWN THIS EVENING AS PER
CONCURRENCE OF MESOSCALE MODELS. THUS WIND CHILLS WILL BE
IMPROVING MARKEDLY THEN DESPITE THE POTENTIAL FOR A QUICK DROP IN
AIR TEMPERATURES DURING A LIGHT WIND/CLEAR SKY EVENING. INCREASING
MID/HIGH CLOUDS IN MID LEVEL WARM ADVECTION REGIME ALONG WITH
WINDS BECOMING MORE SOUTHERLY WITH TIME OVERNIGHT SUGGESTS AN
EVENING LOW WITH RISING TEMPERATURES AFTER MIDNIGHT. THUS HAVE
TAPERED WIND CHILL ADVISORY EXPIRATIONS FROM SOUTHWEST TO
NORTHEAST WITH TIME...AND ALL AREAS VOID OF HEADLINES BY MIDNIGHT.
DERGAN
&&
.AVIATION...18Z TAFS FOR KOFK...KLNK AND KOMA.
PATCHY STRATO CU COULD GO BROKEN AROUND FL025 FOR A TIME THIS
AFTERNOON BEFORE DISSIPATING BY SUNSET. OTHERWISE VFR CONDITIONS
ARE EXPECTED AT ALL TAF SITES. MID LEVEL SCATTERED TO BROKEN
CLOUDS WILL LIKELY OVERSPREAD THE AREA AFTER MIDNIGHT. NORTHWEST
WINDS 15 TO 25KT SHOULD DIE DOWN TO LESS THAN 10KT SHORTLY AFTER
00Z THEN BECOME SOUTHERLY BEFORE 12Z.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 258 AM CST MON JAN 6 2014/
DISCUSSION...
CENTER OF ARCTIC HIGH PRESSURE HAD SHIFTED SOUTH OF THE AREA AT
08Z OVER OKLAHOMA WITH SURFACE GRADIENT WEAKENING OVER NEBRASKA.
AS A RESULT SURFACE WINDS BECOMING MORE VARIABLE EARLY THIS
MORNING WITH REGARD TO SPEED. SEVERAL SITES REPORTING LESS THAN
10 KTS AT 08Z. WIND CHILL VALUES HOWEVER GENERALLY RANGE FROM -25
TO -35 ACROSS THE FORECAST AREA. RAP INDICATES SURFACE GRADIENT
MAY INCREASE AGAIN DURING THE MORNING WITH WINDS PICKING UP TO
BETWEEN 10 AND 20 KTS.
ADJUSTMENTS TO CURRENT HEADLINES MAY BE NEEDED BEFORE EXPIRATION
BUT WILL PASS THIS ON TO THE DAY SHIFT TO BETTER DELINEATE TRENDS
AND AREAL IMPACT.
TEMPERATURES ARE STILL EXPECTED TO REMAIN BELOW ZERO TODAY FROM
NORTHEAST NEBRASKA INTO SOUTHWEST IOWA WITH ONLY LOW SINGLE
DIGITS TO THE WEST OF THAT AREA. SUBZERO TEMPERATURES LIKELY TO
REMAIN ACROSS MOST OF THE AREA YET TONIGHT BUT RELATIVELY WARMER
TEMPERATURES RETURN ON TUESDAY IN ADVANCE OF A WEAK CLIPPER COMING
OUT OF THE NORTHERN ROCKIES. ANOTHER PUSH OF COLD AIR MOVES INTO
THE REGION BEHIND THIS SYSTEM TUESDAY NIGHT INTO WEDNESDAY BUT NOT
AS EXTREME AS CURRENT AIRMASS OVER THE REGION.
MODELS INDICATE LESS AMPLIFIED FLOW BY WEDNESDAY WITH SPLIT FLOW
DEVELOPING IN THE EXTENDED PORTION OF THE FORECAST. THIS IS
EXPECTED TO RESULT IN TEMPERATURES CLOSER TO NORMAL OR SLIGHTLY
ABOVE FOR EARLY JANUARY. ALTHOUGH NO MAJOR WINTER STORM SYSTEM IS
INDICATED...SHORT WAVES MOVING THROUGH THE FLOW DURING THIS TIME
MAY TRIGGER PERIODS OF LIGHT SNOW FOR PARTS OF THE AREA BUT TIMING
AND STRENGTH UNCERTAIN FOR LIMITED CONFIDENCE IN ANY MENTION
BEYOND SLIGHT POPS.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND CHILL ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NEZ011-012-
015-017-018-032>034-045.
WIND CHILL ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR NEZ065-066-
068-078-088>093.
WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ016-030-
031-042>044-050>053-067.
IA...WIND CHILL ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ055-069-
079-080-091.
WIND CHILL WARNING UNTIL 3 PM CST THIS AFTERNOON FOR IAZ043-056.
WIND CHILL ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ043-056.
WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ090.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
529 AM CST MON JAN 6 2014
.AVIATION...
12Z TAFS FOR KOFK...KOMA AND KLNK.
HIGH PRESSURE RIDGE AXIS WILL MOVE INTO EXTREME ERN NEBRASKA
THROUGH LATE AFTERNOON BEFORE SHIFTING OFF TO THE EAST TONIGHT.
OCCASIONALLY GUSTY NORTHWEST SURFACE WINDS WILL PERSIST TODAY EAST
OF THE RIDGE AXIS BEFORE DECREASING TOWARD SUNSET THEN TURNING SW
THIS EVENING. CLOUD PATCHES...CURRENTLY DIFFICULT TO DISCERN ON
SATELLITE DUE TO SMALL TEMPERATURE CONTRASTS WITH ARCTIC
AIR...WILL SLIDE ACROSS THE TAF SITES THROUGH MIDDAY. THIS COULD
POSSIBLY BRING A PERIOD OF MVFR CIGS TO TAF SITES...ESPECIALLY AT
OMAHA AND NORFOLK. MID CLOUDS ABOVE FL070 SHOULD DEVELOP/SPREAD
ACROSS THE AREA OVERNIGHT AS THE HIGH SLIDES OFF TO THE EAST.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 258 AM CST MON JAN 6 2014/
DISCUSSION...
CENTER OF ARCTIC HIGH PRESSURE HAD SHIFTED SOUTH OF THE AREA AT
08Z OVER OKLAHOMA WITH SURFACE GRADIENT WEAKENING OVER NEBRASKA.
AS A RESULT SURFACE WINDS BECOMING MORE VARIABLE EARLY THIS
MORNING WITH REGARD TO SPEED. SEVERAL SITES REPORTING LESS THAN
10 KTS AT 08Z. WIND CHILL VALUES HOWEVER GENERALLY RANGE FROM -25
TO -35 ACROSS THE FORECAST AREA. RAP INDICATES SURFACE GRADIENT
MAY INCREASE AGAIN DURING THE MORNING WITH WINDS PICKING UP TO
BETWEEN 10 AND 20 KTS.
ADJUSTMENTS TO CURRENT HEADLINES MAY BE NEEDED BEFORE EXPIRATION
BUT WILL PASS THIS ON TO THE DAY SHIFT TO BETTER DELINEATE TRENDS
AND AREAL IMPACT.
TEMPERATURES ARE STILL EXPECTED TO REMAIN BELOW ZERO TODAY FROM
NORTHEAST NEBRASKA INTO SOUTHWEST IOWA WITH ONLY LOW SINGLE
DIGITS TO THE WEST OF THAT AREA. SUBZERO TEMPERATURES LIKELY TO
REMAIN ACROSS MOST OF THE AREA YET TONIGHT BUT RELATIVELY WARMER
TEMPERATURES RETURN ON TUESDAY IN ADVANCE OF A WEAK CLIPPER COMING
OUT OF THE NORTHERN ROCKIES. ANOTHER PUSH OF COLD AIR MOVES INTO
THE REGION BEHIND THIS SYSTEM TUESDAY NIGHT INTO WEDNESDAY BUT NOT
AS EXTREME AS CURRENT AIRMASS OVER THE REGION.
MODELS INDICATE LESS AMPLIFIED FLOW BY WEDNESDAY WITH SPLIT FLOW
DEVELOPING IN THE EXTENDED PORTION OF THE FORECAST. THIS IS
EXPECTED TO RESULT IN TEMPERATURES CLOSER TO NORMAL OR SLIGHTLY
ABOVE FOR EARLY JANUARY. ALTHOUGH NO MAJOR WINTER STORM SYSTEM IS
INDICATED...SHORT WAVES MOVING THROUGH THE FLOW DURING THIS TIME
MAY TRIGGER PERIODS OF LIGHT SNOW FOR PARTS OF THE AREA BUT TIMING
AND STRENGTH UNCERTAIN FOR LIMITED CONFIDENCE IN ANY MENTION
BEYOND SLIGHT POPS.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND CHILL WARNING UNTIL MIDNIGHT CST TONIGHT FOR NEZ011-012-
015>018-030>034-042>045-050>053.
WIND CHILL WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ065>068-
078-088>093.
IA...WIND CHILL WARNING UNTIL MIDNIGHT CST TONIGHT FOR IAZ043-055-056-
069.
WIND CHILL WARNING UNTIL 6 PM CST THIS EVENING FOR IAZ079-080-
090-091.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
258 AM CST MON JAN 6 2014
.DISCUSSION...
CENTER OF ARCTIC HIGH PRESSURE HAD SHIFTED SOUTH OF THE AREA AT
08Z OVER OKLAHOMA WITH SURFACE GRADIENT WEAKENING OVER NEBRASKA.
AS A RESULT SURFACE WINDS BECOMING MORE VARIABLE EARLY THIS
MORNING WITH REGARD TO SPEED. SEVERAL SITES REPORTING LESS THAN
10 KTS AT 08Z. WIND CHILL VALUES HOWEVER GENERALLY RANGE FROM -25
TO -35 ACROSS THE FORECAST AREA. RAP INDICATES SURFACE GRADIENT
MAY INCREASE AGAIN DURING THE MORNING WITH WINDS PICKING UP TO
BETWEEN 10 AND 20 KTS.
ADJUSTMENTS TO CURRENT HEADLINES MAY BE NEEDED BEFORE EXPIRATION
BUT WILL PASS THIS ON TO THE DAY SHIFT TO BETTER DELINEATE TRENDS
AND AREAL IMPACT.
TEMPERATURES ARE STILL EXPECTED TO REMAIN BELOW ZERO TODAY FROM
NORTHEAST NEBRASKA INTO SOUTHWEST IOWA WITH ONLY LOW SINGLE
DIGITS TO THE WEST OF THAT AREA. SUBZERO TEMPERATURES LIKELY TO
REMAIN ACROSS MOST OF THE AREA YET TONIGHT BUT RELATIVELY WARMER
TEMPERATURES RETURN ON TUESDAY IN ADVANCE OF A WEAK CLIPPER COMING
OUT OF THE NORTHERN ROCKIES. ANOTHER PUSH OF COLD AIR MOVES INTO
THE REGION BEHIND THIS SYSTEM TUESDAY NIGHT INTO WEDNESDAY BUT NOT
AS EXTREME AS CURRENT AIRMASS OVER THE REGION.
MODELS INDICATE LESS AMPLIFIED FLOW BY WEDNESDAY WITH SPLIT FLOW
DEVELOPING IN THE EXTENDED PORTION OF THE FORECAST. THIS IS
EXPECTED TO RESULT IN TEMPERATURES CLOSER TO NORMAL OR SLIGHTLY
ABOVE FOR EARLY JANUARY. ALTHOUGH NO MAJOR WINTER STORM SYSTEM IS
INDICATED...SHORT WAVES MOVING THROUGH THE FLOW DURING THIS TIME
MAY TRIGGER PERIODS OF LIGHT SNOW FOR PARTS OF THE AREA BUT TIMING
AND STRENGTH UNCERTAIN FOR LIMITED CONFIDENCE IN ANY MENTION
BEYOND SLIGHT POPS.
&&
.AVIATION...
06Z TAFS FOR KOMA...KOFK...KLNK
CYCLONIC FLOW AROUND THE THE GREAT LAKES LOW WILL CONTINUE TO
PROVIDE A SCT SC DECK THROUGH AT LEAST THE FIRST HALF OF THE
PERIOD. MOST OF THE TIME THE SITES WILL BE VFR...BUT A SHORT
PERIOD OF MVFR CIGS ARE POSSIBLE...ESPECIALLY AT KOFK AND KOMA.
THIS WOULD BE MOST LIKELY LATE TONIGHT AND INTO THE MORNING ON
MONDAY. OTHERWISE GUSTY NORTHWEST WINDS WILL START TO DIMINISH ON
MON AFTERNOON AND WILL EVENTUALLY GO LIGHT AND VARIABLE BY MON
EVENING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND CHILL WARNING UNTIL MIDNIGHT CST TONIGHT FOR NEZ011-012-
015>018-030>034-042>045-050>053.
WIND CHILL WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ065>068-
078-088>093.
IA...WIND CHILL WARNING UNTIL MIDNIGHT CST TONIGHT FOR IAZ043-055-056-
069.
WIND CHILL WARNING UNTIL 6 PM CST THIS EVENING FOR IAZ079-080-
090-091.
&&
$$
FOBERT/BOUSTEAD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
419 AM EST MON JAN 6 2014
.SYNOPSIS...
A STRONG ARCTIC COLD FRONT WILL SWEEP THROUGH THE STATE THIS MORNING.
DANGEROUSLY COLD WIND CHILL VALUES ARE EXPECTED MONDAY NIGHT
THROUGH WEDNESDAY WITH NEAR RECORD COLD TEMPERATURES. THE ARCTIC
AIR MASS WILL LIFT OUT OF THE AREA LATER THIS WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
POCKETS OF COLD AIR IN THE VALLEYS OF EASTERN PA BEGINNING TO GET
SCOURED OUT EARLY THIS AM...AS DEEP SOUTHERLY FLOW AHEAD OF
APPROACHING COLD FRONT OVERSPREADS THE AREA. 07Z MESONET STILL
SHOWING A FEW SPOTS NR 32F...SO HAVE ISSUED A SPS TO COVER
POCKETS OF LINGERING ICY PATCHES ACROSS THE SC MTNS AND SUSQ
VALLEY THRU 08Z. THE WARMER/MOIST SOUTHERLY FLOW OVERIDING SNOW
COVERED GROUND HAS RESULTED IN AREAS OF DENSE FOG ACROSS THE LOWER
SUSQ VALLEY. LATEST SREF AND RAP SUGGEST PATCHY DENSE FOG MAY
PERSIST UNTIL ARRIVAL OF ARCTIC COLD FRONT ARND DAWN.
07Z REGIONAL RADAR LOOP SHOWS BAND OF RAIN FALLING ACROSS WESTERN
PA ALONG AXIS OF LL JET/ANOMALOUS PWATS PRECEDING COLD FRONT.
THIS BAND OF RAIN WILL CROSS CENTRAL PA DURING THE EARLY AM
HOURS...EXITING THE EASTERN COUNTIES SHORTLY AFTER 12Z. REGIONAL
RADAR/SFC OBS SHOW PRECIP TURNING TO A BRIEF PERIOD OF SNOW ACROSS
OHIO...AND MDL SOUNDINGS SUGGEST A SIMILAR TRANSITION WILL OCCUR
OVR THE W MTNS BTWN 09Z-12Z. A LIGHT ACCUM OF AN INCH OR LESS
APPEARS MOST LIKELY ACROSS THE ALLEGHENY PLATEAU...WHILE
DRYING/DOWNSLOPING FLOW IS LIKELY TO RESULT IN NO ACCUMS FOR MOST
SPOTS EAST OF THE ALLEGHENIES. HAVE ISSUED A SPS TO COVER THE
LIKELIHOOD OF A FLASH FREEZE/BLACK ICE OVR THE W MTNS...WHERE
PLUMMETING TEMPS WILL LIKELY TURN ANY SLUSH TO ICE.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
STRONG COLD ADVECTION WILL PREVAIL THROUGHOUT THE DAY BEHIND THE
FRONT...WHICH EXITS THE EAST EARLY MONDAY MORNING. FLASH FREEZES
WILL BE POSSIBLE WITH RAPIDLY PLUNGING TEMPERATURES AND WIND
CHILLS RATCHETING UP TO UNCOMFORTABLE RANGES LATE MORNING AND
AFTERNOON. TEMPS WILL FALL THROUGHOUT THE DAY...THANKS TO 850 MB
TEMPS PLUNGING TO AS LOW AS -25 TO -27C BY MONDAY EVENING.
ASTOUNDING.
WIND CHILL WATCHES UPGRADED TO WARNINGS BEGINNING MONDAY AFTERNOON
FOR THE ALLEGHENY PLATEAU. WIND CHILLS OF -25F TO AS LOW AT -35F OR
EVEN -40F WILL BE POSSIBLE FROM MONDAY EVENING THROUGH WEDNESDAY
MORNING. BRR... WIND CHILL WATCHES REMAIN IN EFFECT FARTHER EAST
ACROSS THE REMAINDER OF THE LAUREL HIGHLANDS...AND THE CENTRAL AND
NORTH CENTRAL MOUNTAINS. BY LATE AFTERNOON...TEMPS WILL BE IN THE
SINGLE DIGITS ABOVE ZERO ACROSS THE NORTHWEST MOUNTAINS...RANGING
TO THE MID TEENS CENTRAL MOUNTAINS AND TO THE MID TO UPPER 20S
SOUTHEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MAIN CHANGE WAS TO POST A LAKE SNOW ADVISORY FOR WARREN.
OFTEN WHEN THE AIRMASS IS REAL COLD...THE COLD AIR COMES
IN FROM THE SW. THIS MAY LIMIT THE LAKE EFFECT AT TIMES
ACROSS THE NW...BUT EVEN WITH THIS...THE STRONG FLOW WILL
LIKELY CARRY THE SNOW SHOWERS WELL TO THE EAST.
ALSO PUT SOME MENTION OF SNOW SHOWERS IN THE LAUREL HIGHLANDS.
HARD TO SEE HOW UPSLOPE FLOW WILL NOT RESULT IN SOME SNOW
SHOWERS...EVEN WITH THIN SC DECK.
OTHER CHANGE WAS TO CUT BACK POPS LATE IN THE WEEK. WEIGHTED
FORECAST TO WPC CHARTS.
EXPECT SOME WARM UP LATE IN THE WEEK...A LOT OF MODEL SPREAD.
PART OF THE AREA UPGRADED TO A WIND CHILL WARNING.
EARLIER DISCUSSION BELOW.
AIR MASS AS DEFINED BY 8H TEMPS COULD BE THE COLDEST THIS
REGION HAS SEEN IN 20 YEARS. BY TUES AM...THE CORE OF THE COLD
SHOULD LIE ACROSS SOUTHWEST PA...WHERE GEFS ENS MEAN 8H TEMPS FALL
TO -30C. THE FRIGID TEMPS...COMBINED WITH WGUSTS ARND 30KTS MON
NIGHT THRU TUESDAY WILL RESULT IN EXTREMELY DANGEROUS
CONDITIONS...MAKING FROSTBITE AND HYPOTHERMIA A REAL CONCERN EVEN
IF EXPOSED TO THE ELEMENTS FOR ONLY A SHORT PERIOD. HAVE EXPANDED
THE WIND CHILL WATCH EASTWARD INTO THE RIDGE/VALLEY REGION...AS
CONFIDENCE INCREASES THAT WARNING CRITERIA OF 25 BLW WILL BE
REACHED. ALTHOUGH IT APPEARS UNLIKELY WE WILL RIVAL THE MIN TEMPS
OF 1994...WIND CHILLS MAY BE AS COLD OR COLDER AS TIGHT PRES
GRADIENT CONTINUES TO BUFFET THE AREA WITH GUSTS NR 30KTS INTO TUE
EVENING.
SIG LAKE EFFECT DOES NOT APPEAR TO BE A CONCERN...AS MDL DATA
INDICATES BLYR FLOW WILL KEEP SNOW SHOWERS NORTH OF THE BORDER
MON-WED. WEDNESDAY MORNING WILL ALSO BE VERY COLD...AS WINDS
SLACKEN UPON ARRIVAL OF SFC HIGH. MODEL CONSENSUS SUPPORTS TEMPS
SLOWLY MODERATING BACK TOWARDS NORMAL BY THE SECOND HALF OF THE
WEEK. A LIGHT OVERRUNNING SNOWFALL IS POSSIBLE LATE WEEK...AS
WARMER SW FLOW TRIES TO DISLODGE LINGERING LOW LVL CHILL ACROSS
THE NORTHEAST CONUS.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A SHARP ARCTIC COLD FRONT WILL SWEEP ACROSS CENTRAL PA THROUGH
MID MORNING...WITH LLWS AS STRONG SOUTHERLY LOW LEVEL JET SHIFTS
TO THE WEST BY 14Z.
QUITE VARIABLE CONDITIONS ACROSS CENTRAL PA THIS MORNING AHEAD OF
QUICKLY APPROACHING ARCTIC FRONT. IN THE SUSQ VALLEY...REDUCTIONS
IN FOG WILL PERSIST THROUGH 12-14Z WITH POCKETS OF FZDZ. CENTRAL
TERMINALS MAY SEE CIGS LIFT BRIEFLY BEFORE SUNRISE BEFORE FALLING
BACK TO MVFR/IFR AS SOUTHERLY WIND GUSTS APPROACH 35 MPH. WESTERN
TERMINALS AND RIDGES WILL SEE SOUTHWEST WINDS GUST TO AS HIGH AS
45 KTS BETWEEN 09-11Z BEFORE FLOW TURNS WESTERLY AND CIGS LOWER
FURTHER WITH LIGHT SNOW.
BY 14Z...GUSTY WINDS WILL TURN TO THE WEST AT ALL TAF SITES AS
MUCH COLDER AIR BARRELS IN. THEN FROM LATE MORNING INTO EARLY
AFTERNOON...CIGS AND VSBYS WILL GRADUALLY LIFT AND IMPROVE OVER
THE CENTRAL AND SE...WHILE MVFR CIGS PERSIST IN WESTERN HIGHER
ELEVATIONS. AFTER THAT...PERSISTENCE WILL BE THE RULE WITH MVFR
WEST AND WINDY CONDITIONS AREAWIDE INTO TUESDAY.
OUTLOOK...
TUE...SCT SNOW SHOWERS NW. VFR ELSEWHERE. WINDY.
WED...SCT SNOW SHOWERS NW. VFR ELSEWHERE.
THU...MVFR TO IFR WITH CHC LIGHT SNOW/MIXED PRECIP LATE.
FRI...MIXED PRECIPITATION WITH IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR PAZ012-018-019-025>027-034-035-037-041-042-045-046.
WIND CHILL WARNING FROM 3 PM THIS AFTERNOON TO NOON EST
WEDNESDAY FOR PAZ004>006-010-011-017-024-033.
DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
PAZ036-056>059-063>066.
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR PAZ004.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
203 AM EST MON JAN 6 2014
.SYNOPSIS...
A STRONG ARCTIC COLD FRONT WILL SWEEP THROUGH THE STATE THIS MORNING.
DANGEROUSLY COLD WIND CHILL VALUES ARE EXPECTED MONDAY NIGHT
THROUGH WEDNESDAY WITH NEAR RECORD COLD TEMPERATURES. THE ARCTIC
AIR MASS WILL LIFT OUT OF THE AREA LATER THIS WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
POCKETS OF COLD AIR IN THE VALLEYS OF EASTERN PA BEGINNING TO GET
SCOURED OUT EARLY THIS AM...AS DEEP SOUTHERLY FLOW AHEAD OF
APPROACHING COLD FRONT OVERSPREADS THE AREA. 07Z MESONET STILL
SHOWING A FEW SPOTS NR 32F...SO HAVE ISSUED A SPS TO COVER
POCKETS OF LINGERING ICY PATCHES ACROSS THE SC MTNS AND SUSQ
VALLEY THRU 08Z. THE WARMER/MOIST SOUTHERLY FLOW OVERIDING SNOW
COVERED GROUND HAS RESULTED IN AREAS OF DENSE FOG ACROSS THE LOWER
SUSQ VALLEY. LATEST SREF AND RAP SUGGEST PATCHY DENSE FOG MAY
PERSIST UNTIL ARRIVAL OF ARCTIC COLD FRONT ARND DAWN.
07Z REGIONAL RADAR LOOP SHOWS BAND OF RAIN FALLING ACROSS WESTERN
PA ALONG AXIS OF LL JET/ANOMALOUS PWATS PRECEDING COLD FRONT.
THIS BAND OF RAIN WILL CROSS CENTRAL PA DURING THE EARLY AM
HOURS...EXITING THE EASTERN COUNTIES SHORTLY AFTER 12Z. REGIONAL
RADAR/SFC OBS SHOW PRECIP TURNING TO A BRIEF PERIOD OF SNOW ACROSS
OHIO...AND MDL SOUNDINGS SUGGEST A SIMILAR TRANSITION WILL OCCUR
OVR THE W MTNS BTWN 09Z-12Z. A LIGHT ACCUM OF AN INCH OR LESS
APPEARS MOST LIKELY ACROSS THE ALLEGHENY PLATEAU...WHILE
DRYING/DOWNSLOPING FLOW IS LIKELY TO RESULT IN NO ACCUMS FOR MOST
SPOTS EAST OF THE ALLEGHENIES. HAVE ISSUED A SPS TO COVER THE
LIKELIHOOD OF A FLASH FREEZE/BLACK ICE OVR THE W MTNS...WHERE
PLUMMETING TEMPS WILL LIKELY TURN ANY SLUSH TO ICE.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
STRONG COLD ADVECTION WILL PREVAIL THROUGHOUT THE DAY BEHIND THE
FRONT...WHICH EXITS THE EAST EARLY MONDAY MORNING. FLASH FREEZES
WILL BE POSSIBLE WITH RAPIDLY PLUNGING TEMPERATURES AND WIND
CHILLS RATCHETING UP TO UNCOMFORTABLE RANGES LATE MORNING AND
AFTERNOON. TEMPS WILL FALL THROUGHOUT THE DAY...THANKS TO 850 MB
TEMPS PLUNGING TO AS LOW AS -25 TO -27C BY MONDAY EVENING.
ASTOUNDING.
WIND CHILL WATCHES UPGRADED TO WARNINGS BEGINNING MONDAY AFTERNOON
FOR THE ALLEGHENY PLATEAU. WIND CHILLS OF -25F TO AS LOW AT -35F OR
EVEN -40F WILL BE POSSIBLE FROM MONDAY EVENING THROUGH WEDNESDAY
MORNING. BRR... WIND CHILL WATCHES REMAIN IN EFFECT FARTHER EAST
ACROSS THE REMAINDER OF THE LAUREL HIGHLANDS...AND THE CENTRAL AND
NORTH CENTRAL MOUNTAINS. BY LATE AFTERNOON...TEMPS WILL BE IN THE
SINGLE DIGITS ABOVE ZERO ACROSS THE NORTHWEST MOUNTAINS...RANGING
TO THE MID TEENS CENTRAL MOUNTAINS AND TO THE MID TO UPPER 20S
SOUTHEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MAIN CHANGE WAS TO POST A LAKE SNOW ADVISORY FOR WARREN.
OFTEN WHEN THE AIRMASS IS REAL COLD...THE COLD AIR COMES
IN FROM THE SW. THIS MAY LIMIT THE LAKE EFFECT AT TIMES
ACROSS THE NW...BUT EVEN WITH THIS...THE STRONG FLOW WILL
LIKELY CARRY THE SNOW SHOWERS WELL TO THE EAST.
ALSO PUT SOME MENTION OF SNOW SHOWERS IN THE LAUREL HIGHLANDS.
HARD TO SEE HOW UPSLOPE FLOW WILL NOT RESULT IN SOME SNOW
SHOWERS...EVEN WITH THIN SC DECK.
OTHER CHANGE WAS TO CUT BACK POPS LATE IN THE WEEK. WEIGHTED
FORECAST TO WPC CHARTS.
EXPECT SOME WARM UP LATE IN THE WEEK...A LOT OF MODEL SPREAD.
PART OF THE AREA UPGRADED TO A WIND CHILL WARNING.
EARLIER DISCUSSION BELOW.
AIR MASS AS DEFINED BY 8H TEMPS COULD BE THE COLDEST THIS
REGION HAS SEEN IN 20 YEARS. BY TUES AM...THE CORE OF THE COLD
SHOULD LIE ACROSS SOUTHWEST PA...WHERE GEFS ENS MEAN 8H TEMPS FALL
TO -30C. THE FRIGID TEMPS...COMBINED WITH WGUSTS ARND 30KTS MON
NIGHT THRU TUESDAY WILL RESULT IN EXTREMELY DANGEROUS
CONDITIONS...MAKING FROSTBITE AND HYPOTHERMIA A REAL CONCERN EVEN
IF EXPOSED TO THE ELEMENTS FOR ONLY A SHORT PERIOD. HAVE EXPANDED
THE WIND CHILL WATCH EASTWARD INTO THE RIDGE/VALLEY REGION...AS
CONFIDENCE INCREASES THAT WARNING CRITERIA OF 25 BLW WILL BE
REACHED. ALTHOUGH IT APPEARS UNLIKELY WE WILL RIVAL THE MIN TEMPS
OF 1994...WIND CHILLS MAY BE AS COLD OR COLDER AS TIGHT PRES
GRADIENT CONTINUES TO BUFFET THE AREA WITH GUSTS NR 30KTS INTO TUE
EVENING.
SIG LAKE EFFECT DOES NOT APPEAR TO BE A CONCERN...AS MDL DATA
INDICATES BLYR FLOW WILL KEEP SNOW SHOWERS NORTH OF THE BORDER
MON-WED. WEDNESDAY MORNING WILL ALSO BE VERY COLD...AS WINDS
SLACKEN UPON ARRIVAL OF SFC HIGH. MODEL CONSENSUS SUPPORTS TEMPS
SLOWLY MODERATING BACK TOWARDS NORMAL BY THE SECOND HALF OF THE
WEEK. A LIGHT OVERRUNNING SNOWFALL IS POSSIBLE LATE WEEK...AS
WARMER SW FLOW TRIES TO DISLODGE LINGERING LOW LVL CHILL ACROSS
THE NORTHEAST CONUS.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
SOUTHERLY FLOW CONTINUES AS PRECIPITATION CHANGES OVER TO RAIN AS
THE CURRENT TEMPERATURES ARE GENERALLY SLIGHTLY ABOVE FREEZING.
THERE REMAINS SOME HOLD OUTS THROUGH THE SOUTHEAST WHERE
INTERMITTENT PRECIPTIATION COULD COME DOWN AS -FZRA BRIEFLY. THIS
P TYPE CHANGE SHOULD CONTINUE OVERNIGHT. LIFR AND LOWER CONDITIONS
WILL BE WIDESPREAD FOR ALL TAF SITES EXCEPT IPT...WHERE RAIN IS
FALLING. THOSE SITES SHOULD GO TO IFR AND LOWER RESTRICTIONS AT
TIMES BETWEEN 06 AND 12Z.
A STARK FRONT WILL MOVE THROUGH THE REGION TOMORROW
MORNING...BRINGING A WIND SHIFT WITH GUSTY WINDS OUT OF THE WEST
BY 12Z. GUSTY WINDS HAVE CURRENTLY ENTRENCHED THEMSELVES AT THE HIGHER
ELEVATIONS DUE TO THE STRONG SOUTHERLY FLOW OUT AHEAD OF THIS
DEEPENING TROUGH. CIGS AND VSBYS WILL CONTINUE IFR AND LOWER
RESTRICTIONS AS SYNOPTIC LIFT INCREASES WITH ARRIVAL OF THE
AFOREMENTIONED DEEPENING LOW PRESSURE FROM THE OHIO VALLEY. THE
WARMER AIR MOVING OVER THE SNOWPACK IN THE EAST WILL LIKELY
CONTINUE TO GENERATE AN AREA OF THICKER FOG THAT IS CURRENTLY
REDUCING VSBYS ACROSS THE LOWER SUSQ AND AOO...REDUCING VSBYS
BELOW A MILE. LLWS INCLUDED IN TAFS AS 850 MB JET INCREASES TO
40-60 KTS AND WILL CONTINUE UNTIL AROUND 12Z.
THE GUSTY RAIN SHOWERS THAT WILL LIKELY ACCOMPANY FROPA ALONG AN
AXIS OF ANOMALOUS SOUTHERLY LL JET/PWATS. ARRIVAL OF MUCH COLDER
AIR WILL TURN THE SHRA TO SHSN FROM 12Z TO 16Z. ONCE THE FRONT
EXITS...CIGSY AND VSBYS SHOULD LIFT AND IMPROVE...WITH MVFR
CONDITIONS POSSIBLE UNTIL 18Z AND MOST IF NOT ALL TAF SITES GOING
VFR BY 00Z TUESDAYE.
OUTLOOK...
MON...RESTRICTIONS IN THE MORNING...THEN IMPROVING CIGS /ESP SE
HALF/ AS STRONG WESTERLY WINDS DEVELOP.
TUE...SCT SNOW SHOWERS NW. VFR ELSEWHERE. WINDY.
WED...SCT SNOW SHOWERS NW. VFR ELSEWHERE.
THU...MVFR TO IFR WITH CHC LIGHT SNOW/MIXED PRECIP LATE.
FRI...MIXED PRECIPITATION WITH IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR PAZ012-018-019-025>027-034-035-037-041-042-045-046.
WIND CHILL WARNING FROM 3 PM THIS AFTERNOON TO NOON EST
WEDNESDAY FOR PAZ004>006-010-011-017-024-033.
DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
PAZ036-056>059-063>066.
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR PAZ004.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/MARTIN
AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
834 PM CST TUE JAN 7 2014
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 822 PM CST TUE JAN 7 2014
NOW THAT THE CORE OF THE COLD IS OFF TO OUR E...TEMPS WL BE DRIVEN
BY MORE THAN JUST ADVECTION. SML LEAF-LIKE PATCH OF HIGH AC
COMING ACRS THE SRN PART OF THE FCST AREA AS HOLDING TEMPS UP.
THAT SHOULD EXIT THE SE PART OF THE AREA ARND MIDNIGHT. ADJUSTED
HOURLY TEMP GRIDS TO ACCOUNT FOR THE FEATURE. IT MAY BE HOLDING
TEMPS UP NOW...BUT SHOULD DEPART IN TIME TO NOT HAVE A SIG IMPACT
ON MINS.
WHERE SKIES WERE CLEAR...DECRG SFC PRESSURE GRADIENT HAS ALLOWED
WINDS TO DIE OFF IN THE TYPICAL COLDS SPOTS IN NRN WI...AND TEMPS
HAVE TANKED. LNL ALREADY DOWN AS LOW AS 26 BELOW. EXPECT SITES
LIKE D25/RHI/TKV/RRL/EGV TO FOLLOW DURING THE NIGHT. TWEAKED MINS
DOWN SOME IN THESE AREAS.
WINDS WERE GENERALLY MARGINAL FOR A WIND CHILL ADVISORY. THOSE
SITES THAT STILL HAD WIND WERE MOSTLY NOT MEETING CRITERIA. BUT
TEMPS WL BE FALLING TO VERY COLD READINGS...AND DON/T THINK MOST
SITES WL BE CALM ALL NGT. WITH MIN WIND SPEED CRITERIA FOR A WIND
CHILL HEADLINE NOW ONLY 4 MPH...THERE WL CERTAINLY BE TIMES WHEN
CRITERIA ARE MET ACRS ALMOST THE ENTIRE AREA BY MORNING. AND THE
FEW SPOTS THAT STAY CALM MAY WELL BE APPROACHING 30 BELOW AIR
TEMPERATURES. SO...WL LEAVE THE ADVISORY INTACT.
UPDATED GRIDS AND DERIVED ZONES/AFM/PFM ALREADY OUT.
UPDATED WSW AND HWO TO FOLLOW SHORTLY.
&&
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 240 PM CST TUE JAN 7 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE CENTERED OVER THE GULF COAST...AND A RIDGE AXIS EXTENDING
NORTHEAST ACROSS THE PLAINS TO CENTRAL CANADA. AREAS OF LOW CLOUD
COVER CONTINUE TO FLOW SOUTHEAST AHEAD OF THE RIDGE AXIS FROM SOUTHERN
CANADA AND NORTHERN MINNESOTA AND INTO WISCONSIN...BUT THE LATEST
SATELLITE IMAGES SHOW THE STRATUS DISSIPATING AS IT MOVES INTO
NORTH-CENTRAL WISCONSIN. WITH PARTLY TO MOSTLY SUNNY
CONDITIONS...TEMPERATURES AND WIND CHILLS HAVE WARMED INTO THE
SINGLE DIGITS BELOW ZERO AND BETWEEN 20 TO 30 DEGREES BELOW ZERO
RESPECTIVELY. AS HIGH PRESSURE SHIFTS EAST INTO THE REGION OVER THE
NEXT 24 HOURS...TEMPS AND WIND CHILLS REMAIN THE MAIN FORECAST
CONCERNS...FOLLOWED BY CLOUDS.
TONIGHT...THE SURFACE RIDGE AXIS OVER THE NORTHERN MISSISSIPPI
VALLEY AND NORTHERN PLAINS WILL MOVE EAST TOWARDS THE STATE. AREAS OF LOW
STRATUS UPSTREAM WILL CONTINUE TO FLOW SOUTHEAST AHEAD OF THE
SURFACE HIGH WHICH MAKES CLOUD FORECAST PROBLEMATIC. DO NOT THINK
MODELS HAVE A GOOD HANDLE ON THIS CLOUD COVER...BUT DO INDICATE
DIMINISHING LOW LEVEL RH THAT WOULD POINT TOWARDS THIS CLOUD COVER
BREAKING UP. SO GENERALLY WENT WITH MOSTLY CLEAR TO PARTLY CLOUDY
CONDITIONS FOR THE EVENING...WITH A LITTLE HIGHER CLOUD COVER OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN...THEN SKY CONDITIONS TURNING
MOSTLY CLEAR EVERYWHERE OVERNIGHT. DUE TO THE INCOMING SURFACE
HIGH...WINDS WILL BE SUBSIDING TONIGHT...AND SOME POTENTIAL FOR
DECOUPLING OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. LOW LEVEL
WINDS WILL BE RIGHT ON THE CUSP...AND IF THIS OCCURS...LOW TEMPS
WILL BE SEVERAL DEGREES COLDER THAN IN THE GOING FORECAST. AS A
RESULT...DID SIDE WITH THE COLDER GUIDANCE BUT DID NOT GO WITH THE
COLDEST SOLUTIONS IN CASE DECOUPLING DID NOT OCCUR. THIS WOULD
PLACE LOW TEMPS MAINLY BETWEEN 10 AND 20 BELOW...WITH A FEW COLDER
SPOTS OVER N-C WISCONSIN...AND A FEW WARMER SPOTS NEAR THE LAKE
SHORE. WIND CHILLS WILL FALL TO 25 T0 35 DEGREES BELOW ZERO. WIND
CHILL ADVISORY HEADLINES WILL GO ON AS PLANNED...WITH THE CAVEAT
THAT SOME LOCATIONS MAY SEE A CALM WIND FOR A PERIOD LATE TONIGHT.
WEDNESDAY...HIGH PRESSURE WILL MOVE OVER THE AREA. TEMPERATURES
WILL CONTINUE THEIR SLOW MODERATION...AND WITH PLENTY OF
SUNSHINE...READINGS WILL RETURN TO THE SINGLE DIGITS ABOVE ZERO.
APPARENT TEMPS WILL RISE ABOVE ADVISORY CRITERIA BY LATE IN THE
MORNING...SO WILL RUN HEADLINES THROUGH 18Z.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 240 PM CST TUE JAN 7 2014
ARCTIC AIR MASS WITH SUB ZERO LOW TEMPERATURES WILL LINGER
WEDNESDAY NIGHT DUE TO ANTICIPATED CLEAR SKIES AND CALM WINDS UNDER
THE SURFACE HIGH PRESSURE SYSTEM.
ATTENTION THEN TURNS TO PCPN POTENTIAL LATE IN THE WEEK WITH THE
WAA FLOW. INITIAL WEAK SHORT WAVE PASSES JUST SOUTH OF THE AREA
THURSDAY INTO THURSDAY NIGHT. CONSIDERED ADDING A SLIGHT CHANCE OF
PCPN BUT UNSURE OF SATURATION FOR NOW. LATER SHIFTS CAN SOME ZL-
THURSDAY NIGHT IF WARRANTED.
MAIN SHORTWAVE TO PASS OVER LATER FRIDAY INTO FRIDAY EVENING WITH
PROGS INDICATED UP TO 0.25 WATER EQUIVALENT BY FRIDAY MIDNIGHT
OVER THE SOUTHEAST HALF OF THE FORECAST AREA. FORECAST SOUNDINGS
SUGGESTING A MIX OF ZR/S OVER MOST LOCATIONS AND THEREFORE HAS THE
POTENTIAL OF A HEADLINE FOR MIXED PCPN LATE THIS WEEK. HWO ALREADY
HIGHLIGHTING THIS CONCERN.
SURFACE RIDGE UNDER THE ZONAL FLOW REGIME TO END PCPN SATURDAY MORNING
WITH WAA PATTERN STARTING UP AGAIN SATURDAY NIGHT INTO SUNDAY. THE
FIRST IN A SERIES OF LOW PRESSURE SYSTEMS IS PROGGED TO TRACK
NORTH OF LAKE SUPERIOR LATE NEXT WEEKEND WILL DRAG A COOL FRONT
OVER THE AREA LATER SUNDAY INTO SUNDAY NIGHT...FOLLOWED WITH
ANOTHER CLIPPER SYSTEM NORTH OF THE REGION TOWARD TUESDAY. WILL
CONTINUE LOW END CHANCES OF PCPN WITH THE VARIOUS FROPAS.
FOR WHAT ITS WORTH...END PERIODS OF THE MEDIUM RANGE MODELS ARE
INDICATING SOME COLDER AIR TO WORK TOWARD THE GREAT LAKES REGION
LATE NEXT WEEKEND.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 502 PM CST TUE JAN 7 2014
GENERALLY GOOD FLIGHT CONDITIONS EXPECTED AS ARCTIC AIR DOMINATES
THE AREA. THE ONE POSSIBLE ISSUE IS RELATIVELY SMALL PATCH OF SC
WITH MVFR CIGS DROPPING SE FM THE MN ARROWHEAD. AREA HAS BEEN
SHRINKING...SO FOR NOW WL JUST ALLUDE TO IT WITH SCT020 IN THE RHI
TAF. BUT IF IT HOLDS TOGETHER BETTER THAN EXPECTED...MAY NEED TO
UPDATE TO ADD A PERIOD OF MVFR CIGS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
UPDATE.........SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
505 PM CST TUE JAN 7 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 240 PM CST TUE JAN 7 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE CENTERED OVER THE GULF COAST...AND A RIDGE AXIS EXTENDING
NORTHEAST ACROSS THE PLAINS TO CENTRAL CANADA. AREAS OF LOW CLOUD
COVER CONTINUE TO FLOW SOUTHEAST AHEAD OF THE RIDGE AXIS FROM SOUTHERN
CANADA AND NORTHERN MINNESOTA AND INTO WISCONSIN...BUT THE LATEST
SATELLITE IMAGES SHOW THE STRATUS DISSIPATING AS IT MOVES INTO
NORTH-CENTRAL WISCONSIN. WITH PARTLY TO MOSTLY SUNNY
CONDITIONS...TEMPERATURES AND WIND CHILLS HAVE WARMED INTO THE
SINGLE DIGITS BELOW ZERO AND BETWEEN 20 TO 30 DEGREES BELOW ZERO
RESPECTIVELY. AS HIGH PRESSURE SHIFTS EAST INTO THE REGION OVER THE
NEXT 24 HOURS...TEMPS AND WIND CHILLS REMAIN THE MAIN FORECAST
CONCERNS...FOLLOWED BY CLOUDS.
TONIGHT...THE SURFACE RIDGE AXIS OVER THE NORTHERN MISSISSIPPI
VALLEY AND NORTHERN PLAINS WILL MOVE EAST TOWARDS THE STATE. AREAS OF LOW
STRATUS UPSTREAM WILL CONTINUE TO FLOW SOUTHEAST AHEAD OF THE
SURFACE HIGH WHICH MAKES CLOUD FORECAST PROBLEMATIC. DO NOT THINK
MODELS HAVE A GOOD HANDLE ON THIS CLOUD COVER...BUT DO INDICATE
DIMINISHING LOW LEVEL RH THAT WOULD POINT TOWARDS THIS CLOUD COVER
BREAKING UP. SO GENERALLY WENT WITH MOSTLY CLEAR TO PARTLY CLOUDY
CONDITIONS FOR THE EVENING...WITH A LITTLE HIGHER CLOUD COVER OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN...THEN SKY CONDITIONS TURNING
MOSTLY CLEAR EVERYWHERE OVERNIGHT. DUE TO THE INCOMING SURFACE
HIGH...WINDS WILL BE SUBSIDING TONIGHT...AND SOME POTENTIAL FOR
DECOUPLING OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. LOW LEVEL
WINDS WILL BE RIGHT ON THE CUSP...AND IF THIS OCCURS...LOW TEMPS
WILL BE SEVERAL DEGREES COLDER THAN IN THE GOING FORECAST. AS A
RESULT...DID SIDE WITH THE COLDER GUIDANCE BUT DID NOT GO WITH THE
COLDEST SOLUTIONS IN CASE DECOUPLING DID NOT OCCUR. THIS WOULD
PLACE LOW TEMPS MAINLY BETWEEN 10 AND 20 BELOW...WITH A FEW COLDER
SPOTS OVER N-C WISCONSIN...AND A FEW WARMER SPOTS NEAR THE LAKE
SHORE. WIND CHILLS WILL FALL TO 25 T0 35 DEGREES BELOW ZERO. WIND
CHILL ADVISORY HEADLINES WILL GO ON AS PLANNED...WITH THE CAVEAT
THAT SOME LOCATIONS MAY SEE A CALM WIND FOR A PERIOD LATE TONIGHT.
WEDNESDAY...HIGH PRESSURE WILL MOVE OVER THE AREA. TEMPERATURES
WILL CONTINUE THEIR SLOW MODERATION...AND WITH PLENTY OF
SUNSHINE...READINGS WILL RETURN TO THE SINGLE DIGITS ABOVE ZERO.
APPARENT TEMPS WILL RISE ABOVE ADVISORY CRITERIA BY LATE IN THE
MORNING...SO WILL RUN HEADLINES THROUGH 18Z.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 240 PM CST TUE JAN 7 2014
ARCTIC AIR MASS WITH SUB ZERO LOW TEMPERATURES WILL LINGER
WEDNESDAY NIGHT DUE TO ANTICIPATED CLEAR SKIES AND CALM WINDS UNDER
THE SURFACE HIGH PRESSURE SYSTEM.
ATTENTION THEN TURNS TO PCPN POTENTIAL LATE IN THE WEEK WITH THE
WAA FLOW. INITIAL WEAK SHORT WAVE PASSES JUST SOUTH OF THE AREA
THURSDAY INTO THURSDAY NIGHT. CONSIDERED ADDING A SLIGHT CHANCE OF
PCPN BUT UNSURE OF SATURATION FOR NOW. LATER SHIFTS CAN SOME ZL-
THURSDAY NIGHT IF WARRANTED.
MAIN SHORTWAVE TO PASS OVER LATER FRIDAY INTO FRIDAY EVENING WITH
PROGS INDICATED UP TO 0.25 WATER EQUIVALENT BY FRIDAY MIDNIGHT
OVER THE SOUTHEAST HALF OF THE FORECAST AREA. FORECAST SOUNDINGS
SUGGESTING A MIX OF ZR/S OVER MOST LOCATIONS AND THEREFORE HAS THE
POTENTIAL OF A HEADLINE FOR MIXED PCPN LATE THIS WEEK. HWO ALREADY
HIGHLIGHTING THIS CONCERN.
SURFACE RIDGE UNDER THE ZONAL FLOW REGIME TO END PCPN SATURDAY MORNING
WITH WAA PATTERN STARTING UP AGAIN SATURDAY NIGHT INTO SUNDAY. THE
FIRST IN A SERIES OF LOW PRESSURE SYSTEMS IS PROGGED TO TRACK
NORTH OF LAKE SUPERIOR LATE NEXT WEEKEND WILL DRAG A COOL FRONT
OVER THE AREA LATER SUNDAY INTO SUNDAY NIGHT...FOLLOWED WITH
ANOTHER CLIPPER SYSTEM NORTH OF THE REGION TOWARD TUESDAY. WILL
CONTINUE LOW END CHANCES OF PCPN WITH THE VARIOUS FROPAS.
FOR WHAT ITS WORTH...END PERIODS OF THE MEDIUM RANGE MODELS ARE
INDICATING SOME COLDER AIR TO WORK TOWARD THE GREAT LAKES REGION
LATE NEXT WEEKEND.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 502 PM CST TUE JAN 7 2014
GENERALLY GOOD FLIGHT CONDITIONS EXPECTED AS ARCTIC AIR DOMINATES
THE AREA. THE ONE POSSIBLE ISSUE IS RELATIVELY SMALL PATCH OF SC
WITH MVFR CIGS DROPPING SE FM THE MN ARROWHEAD. AREA HAS BEEN
SHRINKING...SO FOR NOW WL JUST ALLUDE TO IT WITH SCT020 IN THE RHI
TAF. BUT IF IT HOLDS TOGETHER BETTER THAN EXPECTED...MAY NEED TO
UPDATE TO ADD A PERIOD OF MVFR CIGS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
428 PM CST MON JAN 6 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 231 PM CST MON JAN 6 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE STRETCHING FROM SOUTHERN SASKATCHEWAN TO THE GULF COAST OF
TEXAS EARLY THIS AFTERNOON. THE POLAR VORTEX IS SHIFTING EAST INTO
MICHIGAN THOUGH THE CORE OF THE EXTREMELY COLD AIR IS CURRENTLY
OVERHEAD. TEMPERATURES HAVE NOT WARMED TOO MUCH SO FAR TODAY...WITH
READINGS HOLDING STEADY FROM THE LOWER TEENS BELOW ZERO ALONG THE
LAKE MICHIGAN SHORELINE TO THE LOWER 20S BELOW ZERO OVER CENTRAL
WISCONSIN. WIND CHILLS REMAIN IN THE 35 TO 45 DEGREES BELOW ZERO
RANGE. AREAS OF THIN CLOUD COVER CONTINUE TO STREAM SOUTHEAST ON
THE BACKSIDE OF THE POLAR VORTEX...WITH A FEW FLURRIES BEING
REPORTED ON AREA OBSERVATION SITES. AS THE ARCTIC AIR
MODIFIES...TEMPS AND WIND CHILLS REMAIN THE MAIN FORECAST
CONCERNS...FOLLOWED BY CLOUDS/FLURRY CHANCES.
TONIGHT...ARCTIC HIGH PRESSURE WILL SLIDE TO THE GULF COAST...BUT
THE SURFACE RIDGE AXIS WILL HANG BACK ACROSS THE NORTHERN
MISSISSIPPI TO CENTRAL CANADA. THOUGH TEMPERATURES WILL BE
MODIFYING ALOFT...BRISK WEST WINDS WILL CONTINUE TO FUNNEL IN THE
EXTREME COLD FROM THE NORTHERN PLAINS. DO NOT HAVE A GOOD HANDLE ON
CLOUD COVER TONIGHT...BUT WITH THIN CLOUDS DROPPING SOUTH OVER
SOUTHERN CANADA AND MINNESOTA...FIGURE THE REGION WILL HAVE PARTLY
CLOUDY CONDITIONS THROUGH THE EVENING BEFORE A SLIGHT BACKING OF THE
WINDS PUSHES IN DRIER AIR IN AFTER MIDNIGHT. WITH THE SUSTAINED
WINDS AND A MODIFYING AIRMASS...TEMPS WILL BE A DEGREE OR TWO WARMER
OVER WESTERN SECTIONS OF THE FORECAST AREA...THOUGH WILL LIKELY BE A
FEW DEGREES COLDER OVER EASTERN SECTIONS. BUT WITH WINDS REMAINING
IN THE 10-15KT RANGE...WIND CHILLS WILL REMAIN IN THE 40 TO 50
DEGREE BELOW ZERO RANGE. THUS NO CHANGE TO HEADLINES.
TUESDAY...THE SURFACE RIDGE AXIS WILL SHIFT SLIGHTLY INTO WESTERN
WISCONSIN IN THE AFTERNOON WITH ONLY MID AND HIGH CLOUDS MOVING
OVERHEAD. THE WEST WINDS WILL NOT BE AS STRONG OR GUSTY AS
TODAY...AND COMBINED WITH FURTHER MODIFYING OF THE ARCTIC
AIRMASS...SHOULD SEE TEMPS ABOUT 10 DEGREES WARMER THAN TODAY
ACCORDING TO THE LEADING GUIDANCE. THE EXTREMELY COLD WIND CHILLS
ARE EXPECTED TO RISE TO BETWEEN 20 TO 30 DEGREES BELOW ZERO BY EARLY
AFTERNOON.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 231 PM CST MON JAN 6 2014
GRADUALLY IMPROVING TEMPERATURES THIS WEEK WILL BE THE PRIMARY
ISSUE FOLLOWED WITH SOME RESOLUTION WITH A FEW PRECIP CHANCES IN
THE NEAR ZONAL FLOW LATE THIS WEEK AND THROUGH THIS WEEKEND.
FOR STARTERS...ANTICIPATE THE ARCTIC AIR MASS WILL TAKE ITS TIME
TO DEPART THIS WEEK EVEN THOUGH H850 TEMPERATURES INCREASE. VERY
COLD DRY AIR MASS WILL BE RECYCLED BACK NORTH WITH THE RETURN FLOW
THROUGH THURSDAY. ANTICIPATED CLEAR SKIES AND LIGHT WINDS UNDER A
COLD HIGH PRESSURE SYSTEM WILL PROVIDE LARGE DIURNAL CHANGES WITH
SUB ZERO LOW TEMPERATURES CONTINUING INTO THURSDAY MORNING OVER
MOST LOCATIONS.
RETURN SOUTH TO SOUTHWEST FLOW BEGINS LATER THURSDAY SO TEMPS
WILL START TO ASCEND QUICKER WITH TEMPERATURES POSSIBLY REACHING
THE FREEZING MARK THIS WEEKEND OVER PARTS OF THE AREA. CLOUDS MAY
BE ON THE INCREASE OVER SOUTHERN WISCONSIN THROUGH THURSDAY WITH
THE PASSAGE OF A SOUTHERN STREAM SYSTEM TO THE SOUTH...BUT EXPECT THE
AREA TO REMAIN DRY WITH THE SURFACE HIGH STILL SETTLED OVER THE
AREA.
MODEL TIMING OF VARIOUS SHORT WAVES IN THE NEAR ZONAL FLOW POINTING
TO A FRIDAY INTO FRIDAY NIGHT TIME FRAME. A WEAK RIDGE SETTLES
OVER SATURDAY INTO SUNDAY BEFORE POSSIBLY ANOTHER WEAK SYSTEM
PASSES OVER LATER SUNDAY. AGAIN MODEL TIME IN QUESTION DUE TO
TIMING OF THESE SHORT WAVES IN THE ZONAL FLOW AND LIKELY WILL NEED
FURTHER ADJUSTMENTS.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 427 PM CST MON JAN 6 2014
VFR CONDITIONS EXPECTED AS BITTERLY COLD ARCTIC AIR DOMINATES THE
AREA. LLWS WL DEVELOP TNGT AS THE AIR ALOFT STARTS TO WARM...AND
INVERSION STRENGTHENS/LOWERS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
243 PM CST MON JAN 6 2014
...LIFE-THREATENING WIND CHILLS CONTINUE INTO TUESDAY MORNING...
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 243 PM CST MON JAN 6 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA AND AN
ANOMALOUSLY DEEP TROUGH ENCOMPASSING MUCH OF THE EASTERN U.S..
WITHIN THIS DEEP TROUGH...THE POLAR VORTEX STRETCHED FROM NORTHERN
ONTARIO INTO LOWER MI. THE COLDEST AIR ASSOCIATED WITH THE VORTEX
HAS BEEN ON ITS BACK SIDE...NOTED BY 925MB TEMPS AT 12Z OF -34C AT
MPX AND -35C AT INL...OR 3-3.5 STANDARD DEVIATIONS BELOW NORMAL.
THIS ARCTIC AIR HAS MODIFIED SOMEWHAT THROUGH DAYTIME HEATING...BUT
925MB TEMPS PER RAP ANALYSIS ARE STILL NEAR -30C. SURFACE
TEMPERATURES HAVE MANAGED TO CLIMB INTO THE TEENS BELOW ZERO.
HOWEVER...A PERSISTENT 10 TO 20 MPH WIND WITH GUSTS TO 30 MPH HAVE
KEPT WIND CHILLS DOWN TO 35 TO 45 BELOW ZERO. THESE WINDS ARE A
RESULT OF A TIGHT PRESSURE GRADIENT BETWEEN A SURFACE RIDGE OVER
THE DAKOTAS AND A DEEP LOW OVER CENTRAL QUEBEC.
THE POLAR VORTEX IS PROGGED TO GRADUALLY LOSE ITS GRIP ACROSS THE
FORECAST AREA AND GREAT LAKES REGION...LIFTING INTO NORTHERN QUEBEC
BY 00Z WEDNESDAY. THIS WILL ALLOW WARMER AIR TO ENTER THE
REGION. ONE CAVEAT TO THE WARMER AIR IS A SHORTWAVE OVER THE
NORTHWEST TERRITORIES WHICH MODELS SHOW DROPPING DOWN THE BACK SIDE
OF THE VORTEX...COMING INTO NORTHERN WI AT 00Z WEDNESDAY. THIS
SHORTWAVE WILL SLOW SOME OF THE WARM UP.
REGARDING TEMPERATURES...925MB READINGS ARE PROGGED TO CLIMB THROUGH
THE NEXT 24 HOURS...REACHING -24 TO -28C BY 12Z TUE AND TO -18 TO -
22C BY 00Z WED. DESPITE THE WARMING ABOVE THE SURFACE...TEMPERATURES
SHOULD STILL COOL DOWN CLOSE TO READINGS SEEN LAST NIGHT BECAUSE OF
WINDS WHICH ARE GOING TO BE LIGHTER. HOWEVER...A BREEZE WILL PERSIST
SINCE THE SURFACE RIDGE IS STILL OFF TO OUR WEST...WHICH MEANS WIND
CHILL VALUES ARE LIKELY TO STAY BETWEEN 35 AND 55 BELOW ZERO. WINDS
DO MANAGE TO BACK MORE WEST TO POSSIBLY EVEN SOUTHWEST ON TUESDAY...
AHEAD OF A COLD FRONT DROPPING THROUGH MN THAT IS ACCOMPANYING THE
NORTHWEST TERRITORIES SHORTWAVE. THIS BACKING OF WINDS PLUS WARMER
925MB VALUES AND SOME SUN SHOULD HELP BOOST HIGHS TOWARDS THE SINGLE
DIGITS ABOVE ZERO...AT LEAST SOUTHWEST OF I-94. NORTH OF I-94...WIND
CHILL ISSUES ARE GOING TO CONTINUE THROUGH THE AFTERNOON AND AN
ADVISORY WILL BE NEEDED AFTER THE WARNING EXPIRES.
SKY COVER REMAINS A TRICKY FORECAST IN THIS ARCTIC AIRMASS.
ANTICIPATING A PERIOD OF POSSIBLY CLEAR SKIES THIS EVENING ONCE ANY
DIURNAL STRATOCUMULUS DISSIPATES WITH LOSS OF DAYTIME HEATING.
HOWEVER...LOW STRATUS CURRENTLY IN SOUTHERN MANITOBA AND NORTHWEST
MN LOOKS TO MAKE A RUN AT LOCATIONS NORTH OF I-94 LATE THIS EVENING
INTO THE OVERNIGHT HOURS. MID/HIGH CLOUDS SHOULD THEN INCREASE
OVERNIGHT THROUGH TUESDAY...WITH EVEN SOME LOWER STRATUS ACROSS
SOUTHERN PORTIONS OF THE AREA...AS ISENTROPIC LIFT PICKS UP AHEAD
OF THE COLD FRONT AND SHORTWAVE. SOME FLURRIES COULD OCCUR FROM
THE CLOUDS AS WELL ACROSS THE SOUTHWESTERN HALF OF THE AREA ON
TUESDAY AS CLOUD HEIGHTS THERE FALL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 243 PM CST MON JAN 6 2014
MODELS REMAIN IN AGREEMENT SHOWING THE PATTERN GREATLY DEAMPLIFYING
ACROSS THE U.S....BECOMING ZONAL BY THURSDAY MORNING. THIS WILL
SHIFT THE TEMPERATURE FLOW FROM THE ARCTIC TO THE PACIFIC. WE DO
HAVE TO WAIT JUST A LITTLE BIT LONGER AS THAT SHORTWAVE DROPPING
INTO NORTHERN WISCONSIN BRINGS A BRIEF REINFORCING SHOT OF COLD AIR
TUESDAY NIGHT. THIS SHOT OF COLD AIR WILL BE NOTICED THE MOST IN
NORTHERN WI WHERE WIND CHILLS LOOK TO STAY DOWN BETWEEN 20 AND 35
BELOW ZERO. A SURFACE HIGH PRESSURE AREA IS PROGGED TO DRIFT
ACROSS THE FORECAST AREA LATE WEDNESDAY INTO WEDNESDAY NIGHT. THIS
HIGH SHOULD HELP TO CALM THE WINDS DOWN...WHICH DOES BRING A
CONCERN FOR LOW TEMPERATURES WEDNESDAY NIGHT...ESPECIALLY OVER
WISCONSIN. AIRMASS REMAINS QUITE DRY WITH PRECIPITABLE WATER BELOW
0.1 INCHES...SO TEMPERATURES COULD REALLY TANK IN THE TYPICALLY
COLD SPOTS. SOUTHERLY FLOW ON THE BACK SIDE OF THIS HIGH PRESSURE
AREA KICKS WARM ADVECTION INTO HIGH GEAR ON THURSDAY. 925MB TEMPS
CLIMB TO -6 TO -10C. ALTHOUGH THERE MAY BE QUITE A FEW CLOUDS
AROUND...THESE SOUTHERLY WINDS SHOULD HELP PROPEL TEMPERATURES
GENERALLY INTO THE MID TEENS TO AROUND 20...ABOUT 30 DEGREES
WARMER THAN TODAY. NOTE...THERE COULD BE SOME WIND CHILL ISSUES
THURSDAY MORNING AS THE SOUTH WINDS INCREASE. THERE WERE SOME
HINTS OF THE 06.15Z SREF OF SOME POSSIBLE PRECIPITATION WITH THIS
WARM ADVECTION...BUT KEPT THESE OUT WITH NO OTHER DETERMINISTIC
MODEL GUIDANCE SHOWING IT.
HIGHLIGHTS FOR FRIDAY INTO MONDAY...
1. GOOD MODEL AGREEMENT EXISTS THAT A FAIRLY SIGNIFICANT SHORTWAVE
TROUGH WILL MOVE FROM THE PACIFIC NORTHWEST ON THU...TO THE NORTHERN
PLAINS ON FRI AND GREAT LAKES ON SAT. A PLUME OF HIGHER PRECIPITABLE
WATER ON THE ORDER OF A 0.5-0.7 INCHES COMES INTO THE REGION AHEAD
OF THE TROUGH ON FRIDAY. COMBINING THIS MOISTURE WITH THE DPVA AND
ISENTROPIC LOOKS TO YIELD SOME PRECIPITATION. HAVE RAISED POPS ABOUT
5-10 PERCENT...BUT IF THE TRENDS IN THE 06.12Z GFS/ECMWF CONTINUE
THESE CHANCES NEED TO BE RAISED FURTHER. NOTE THAT THE 06.12Z
CANADIAN HOLDS PRECIPITATION OFF TIL FRIDAY NIGHT...WHICH IS PARTLY
THE CAUSE TOO OF THE SMALLER CHANCE INCREASE. THE TYPE IS
SOMEWHAT OF AN ISSUE TOO...DUE TO A LOSS OF ICE IN THE CLOUD AND
WARM LAYER INITIALLY FRIDAY MORNING. IT APPEARS ONCE THINGS
SATURATE...EVAPORATIVE COOLING KNOCKS DOWN ANY WARM LAYER AND CLOUDS
ARE SEEDED WITH ICE. THIS SHOULD OCCUR BY EARLY AFTERNOON.
PRECIPITATION SHOULD END WEST TO EAST FRIDAY NIGHT AS THE SYSTEM
PULLS AWAY. ANY LOSS OF ICE IN THE CLOUDS FRIDAY NIGHT SHOULD OCCUR
AFTER THE PRECIP EXITS.
2. A SERIES OF TWO SHORTWAVE TROUGHS TRACKING ACROSS THE REGION
SUNDAY THROUGH MONDAY. PREVIOUSLY ECMWF RUNS WERE SUGGESTING THAT
THESE TROUGHS WERE GOING TO HOLD BACK OVER THE WESTERN U.S.. NOW
THEY ARE MORE PROGRESSIVE...LIKE THE 05.12Z GFS RUN. THIS MEANS A
BIT LESS CONFIDENCE IN PRECIPITATION AS MOISTURE RETURN BEHIND THE
SATURDAY SYSTEM IS SLOWER TO COME BACK. THEREFORE...CHANCES WERE
LOWERED. IT IS ENTIRELY POSSIBLE SUNDAY THROUGH MONDAY ENDS UP
MAINLY DRY.
3. ABOVE NORMAL TEMPERATURES. BOTH THE FRIDAY AND SUNDAY SHORTWAVE
TROUGHS HELP TO PULL EVEN WARMER AIR INTO THE REGION. 925MB TEMPS
GET UP CLOSE TO 0C ON FRIDAY...COOL SLIGHTLY TO -2 TO -6C ON
SATURDAY...BACK UP TO 0-3C ON SUNDAY AND DOWN TO -2 TO -6C ON
MONDAY. EACH OF THESE DAYS WE SHOULD BE ABLE TO GET HIGHS INTO THE
UPPER 20S TO LOW 30S...AND SUNDAY THERE ARE SIGNS WE COULD TRY TO
PUSH 40. RAISED HIGHS A LITTLE ON SUNDAY AS A RESULT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1141 AM CST MON JAN 6 2014
A WEAK SHORT WAVE TROUGH WILL PRODUCE A SCATTERED TO BROKEN DECK
OF MVFR CLOUDS THIS AFTERNOON. IN ADDITION...WINDS ARE STRONG
ENOUGH THIS AFTERNOON TO KEEP SOME BLOWING SNOW GOING ON IN
SOUTHEAST MN...REDUCING VISIBILITIES TO MVFR/IFR AT TIMES.
ANTICIPATE THIS TO END TOWARDS 00Z AS WINDS DIMINISH SOME.
FOR TONIGHT AND TUESDAY MORNING...THE MODELS CONTINUE TO SHOW
STRONG WARM AIR ADVECTION DEVELOPING ACROSS THE REGION. THIS ALONG
WITH A SHORT WAVE TROUGH MOVING FROM THE NORTHERN PLAINS SOUTHEAST
INTO IOWA WILL PRODUCE A 10 TO 15K DECK OF CLOUDS AFTER 07.08Z.
OVERALL THE DEEPEST MOISTURE WITH THIS SYSTEM LOOKS TO BE ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. AS A RESULT...EXPECT THE
CEILINGS TO LOWER TO AROUND 5K FEET BY 07.15Z AT KRST. THE
CEILINGS MAY EVEN BECOME MVFR ACROSS NORTHEAST IOWA DURING THIS
TIME.
&&
.CLIMATE...
ISSUED AT 243 PM CST MON JAN 6 2014
SO FAR NO RECORDS HAVE BEEN SET AT EITHER LA CROSSE OR ROCHESTER.
HOWEVER...A FEW RECORD LOW TEMPERATURES WERE SET AT COOPERATIVE
OBSERVER SITES...
BYRON MN...........-24. OLD RECORD -10 IN 2010
FRIENDSHIP WI......-22. OLD RECORD -18 IN 1942
OWEN WI............-26. OLD RECORD -26 IN 1979
WINONA DAM 5A MN...-21 OLD RECORD -12 IN 1942
THE COLDEST THE WIND CHILL GOT TO IN LA CROSSE WAS -48 AND AT
ROCHESTER WAS -53. NEITHER MADE IT INTO THE TOP 10...BUT WERE ONLY
ABOUT 5 DEGREES WARMER THAN THE FEBRUARY 2-3 1996 ARCTIC OUTBREAK.
SEE OUR TOP NEWS STORY ON OUR WEBSITE WWW.WEATHER.GOV/ARX FOR MORE
CLIMATE INFORMATION ON THE COLD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR MNZ079-086>088-
094>096.
IA...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE/AJ
CLIMATE...AJ
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 231 PM CST MON JAN 6 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE STRETCHING FROM SOUTHERN SASKATCHEWAN TO THE GULF COAST OF
TEXAS EARLY THIS AFTERNOON. THE POLAR VORTEX IS SHIFTING EAST INTO
MICHIGAN THOUGH THE CORE OF THE EXTREMELY COLD AIR IS CURRENTLY
OVERHEAD. TEMPERATURES HAVE NOT WARMED TOO MUCH SO FAR TODAY...WITH
READINGS HOLDING STEADY FROM THE LOWER TEENS BELOW ZERO ALONG THE
LAKE MICHIGAN SHORELINE TO THE LOWER 20S BELOW ZERO OVER CENTRAL
WISCONSIN. WIND CHILLS REMAIN IN THE 35 TO 45 DEGREES BELOW ZERO
RANGE. AREAS OF THIN CLOUD COVER CONTINUE TO STREAM SOUTHEAST ON
THE BACKSIDE OF THE POLAR VORTEX...WITH A FEW FLURRIES BEING
REPORTED ON AREA OBSERVATION SITES. AS THE ARCTIC AIR
MODIFIES...TEMPS AND WIND CHILLS REMAIN THE MAIN FORECAST
CONCERNS...FOLLOWED BY CLOUDS/FLURRY CHANCES.
TONIGHT...ARCTIC HIGH PRESSURE WILL SLIDE TO THE GULF COAST...BUT
THE SURFACE RIDGE AXIS WILL HANG BACK ACROSS THE NORTHERN
MISSISSIPPI TO CENTRAL CANADA. THOUGH TEMPERATURES WILL BE
MODIFYING ALOFT...BRISK WEST WINDS WILL CONTINUE TO FUNNEL IN THE
EXTREME COLD FROM THE NORTHERN PLAINS. DO NOT HAVE A GOOD HANDLE ON
CLOUD COVER TONIGHT...BUT WITH THIN CLOUDS DROPPING SOUTH OVER
SOUTHERN CANADA AND MINNESOTA...FIGURE THE REGION WILL HAVE PARTLY
CLOUDY CONDITIONS THROUGH THE EVENING BEFORE A SLIGHT BACKING OF THE
WINDS PUSHES IN DRIER AIR IN AFTER MIDNIGHT. WITH THE SUSTAINED
WINDS AND A MODIFYING AIRMASS...TEMPS WILL BE A DEGREE OR TWO WARMER
OVER WESTERN SECTIONS OF THE FORECAST AREA...THOUGH WILL LIKELY BE A
FEW DEGREES COLDER OVER EASTERN SECTIONS. BUT WITH WINDS REMAINING
IN THE 10-15KT RANGE...WIND CHILLS WILL REMAIN IN THE 40 TO 50
DEGREE BELOW ZERO RANGE. THUS NO CHANGE TO HEADLINES.
TUESDAY...THE SURFACE RIDGE AXIS WILL SHIFT SLIGHTLY INTO WESTERN
WISCONSIN IN THE AFTERNOON WITH ONLY MID AND HIGH CLOUDS MOVING
OVERHEAD. THE WEST WINDS WILL NOT BE AS STRONG OR GUSTY AS
TODAY...AND COMBINED WITH FURTHER MODIFYING OF THE ARCTIC
AIRMASS...SHOULD SEE TEMPS ABOUT 10 DEGREES WARMER THAN TODAY
ACCORDING TO THE LEADING GUIDANCE. THE EXTREMELY COLD WIND CHILLS
ARE EXPECTED TO RISE TO BETWEEN 20 TO 30 DEGREES BELOW ZERO BY EARLY
AFTERNOON.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 231 PM CST MON JAN 6 2014
GRADUALLY IMPROVING TEMPERATURES THIS WEEK WILL BE THE PRIMARY
ISSUE FOLLOWED WITH SOME RESOLUTION WITH A FEW PRECIP CHANCES IN
THE NEAR ZONAL FLOW LATE THIS WEEK AND THROUGH THIS WEEKEND.
FOR STARTERS...ANTICIPATE THE ARCTIC AIR MASS WILL TAKE ITS TIME
TO DEPART THIS WEEK EVEN THOUGH H850 TEMPERATURES INCREASE. VERY
COLD DRY AIR MASS WILL BE RECYCLED BACK NORTH WITH THE RETURN FLOW
THROUGH THURSDAY. ANTICIPATED CLEAR SKIES AND LIGHT WINDS UNDER A
COLD HIGH PRESSURE SYSTEM WILL PROVIDE LARGE DIURNAL CHANGES WITH
SUB ZERO LOW TEMPERATURES CONTINUING INTO THURSDAY MORNING OVER
MOST LOCATIONS.
RETURN SOUTH TO SOUTHWEST FLOW BEGINS LATER THURSDAY SO TEMPS
WILL START TO ASCEND QUICKER WITH TEMPERATURES POSSIBLY REACHING
THE FREEZING MARK THIS WEEKEND OVER PARTS OF THE AREA. CLOUDS MAY
BE ON THE INCREASE OVER SOUTHERN WISCONSIN THROUGH THURSDAY WITH
THE PASSAGE OF A SOUTHERN STREAM SYSTEM TO THE SOUTH...BUT EXPECT THE
AREA TO REMAIN DRY WITH THE SURFACE HIGH STILL SETTLED OVER THE
AREA.
MODEL TIMING OF VARIOUS SHORT WAVES IN THE NEAR ZONAL FLOW POINTING
TO A FRIDAY INTO FRIDAY NIGHT TIME FRAME. A WEAK RIDGE SETTLES
OVER SATURDAY INTO SUNDAY BEFORE POSSIBLY ANOTHER WEAK SYSTEM
PASSES OVER LATER SUNDAY. AGAIN MODEL TIME IN QUESTION DUE TO
TIMING OF THESE SHORT WAVES IN THE ZONAL FLOW AND LIKELY WILL NEED
FURTHER ADJUSTMENTS.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1101 AM CST MON JAN 6 2014
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD WITH VARIABLE CIGS.
KEPT SCT-BKN CLOUDS AROUND THROUGH THE EVENING SINCE CLOUDS ARE
HANGING AROUND OVER MINNESOTA. BUT DO THINK CLEARING WILL OCCUR
AFTER MIDNIGHT. AS TEMPERATURES MODERATE ALOFT...A STRONG INVERSION
WILL DEVELOP WHICH WILL PROMOTE INCREASING LOW LEVEL WIND SHEAR.
WESTERLY SURFACE WINDS WILL REMAIN RATHER GUSTY THROUGH THE
AFTERNOON...AND THEN DIMINISH SOMEWHAT AT NIGHT. JUST A FEW HIGH
CLOUDS ON TUESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1119 PM CST SUN JAN 5 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 554 PM CST SUN JAN 5 2014
NOT MEETING CRITERIA YET...BUT WL LET THE WIND CHILL WARNING GO
INTO EFFECT AS SCHEDULED AT 600 PM.
SUSPECT OUR OVERNIGHT MINS MIGHT BE A BIT LOW AND WIND MIGHT BE A
LITTLE HIGH...SO WIND CHILLS MAY NOT BE QUITE AS LOW AS WE HAVE IN
THE FCST. BUT THEY SHOULD STILL MAKE WARNING CRITERIA.
STILL WAITING FOR THE FRONTAL WAVE TO LIFT OFF TO THE NE FOR THE
CORE OF THE COLD TO OVERSPREAD THE AREA. WL SEE HOW THINGS EVOLVE
DURING THE NEXT COUPLE HOURS...AND MAY MAKE SOME SML ADJUSTMENTS
TO THE FCST A LITTLE LATER THIS EVENING.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 204 PM CST SUN JAN 5 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRENGTHENING
AREA OF LOW PRESSURE MOVING NORTHEAST OVER THE OHIO VALLEY. A WIDE
SWATH OF HEAVY SNOW IS IMPACTING ST LOUIS TO THE THUMB OF MICHIGAN JUST
NORTH OF THE SURFACE LOW TRACK...AND IS NOT SHOWING ANY SIGNS OF
LIFTING INTO EAST-CENTRAL WISCONSIN. ALTOSTRATUS ON THE NORTHERN
PERIPHERY OF THIS SYSTEM IS MOVING ACROSS MUCH OF CENTRAL AND NORTHEAST
WISCONSIN AND IS PREVENTING ANY SUNSHINE TO OFFSET THE COLD
TEMPERATURES. READINGS THIS AFTERNOON REMAIN BELOW ZERO WEST OF A
WAUTOMA TO IRON MOUNTAIN LINE...WHERE WIND CHILLS ARE NEAR OR BELOW
WIND CHILL ADVISORY CRITERIA (-20F). FARTHER WEST...A LOBE OF THE
POLAR VORTEX IS DROPPING SOUTHEAST OVER THE DAKOTAS WHERE TEMPS ARE
IN THE TEENS BELOW ZERO WITH WINDS GUSTING OVER 40 KTS. ALSO SEEING
LOWER VSBYS WITHIN SOME CLOUD COVER IN THIS REGION...BUT THINK MUCH
OF THESE OBS CAN BE ATTRIBUTED TO BLOWING SNOW. AS THE POLAR VORTEX
AND ASSOCIATED ARCTIC AIR MOVES ACROSS THE REGION...LIGHT SNOW
CHANCES AND WIND CHILL HEADLINES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE LOW PRESSURE SYSTEM WILL MOVE FROM THE OHIO VALLEY TO THE
EASTERN GREAT LAKES THIS EVENING. CYCLONIC FLOW AROUND THE LOW WILL
DELAY THE BITTERLY COLD ARCTIC AIR FROM REACHING NORTHEAST WISCONSIN
UNTIL LATE IN THE EVENING OR EARLY OVERNIGHT. OTHERWISE A LOBE OF
THE POLAR VORTEX WILL SWING EAST FROM THE NORTHERN MISSISSIPPI
VALLEY TO NORTHEAST WISCONSIN. AS THIS OCCURS...SHOULD SEE AN AREA
OF LOW AND MID CLOUDS MOVE EAST OVER THE FORECAST AREA. SINCE THE
LOWER VSBYS OVER THE DAKOTAS HAS THE LOOK OF BLOWING SNOW...WILL
REMOVE THE FLURRY MENTION AFTER MIDNIGHT. HOWEVER...MODELS TRY TO
RETURN SOME MOISTURE FROM THE SOUTH AHEAD OF THE SHORTWAVE LOBE AND
PRODUCE LIGHT SNOW OR FLURRIES ALONG THE LAKE MICHIGAN SHORELINE
LATE TONIGHT. THIS POSSIBILITY STILL LOOKS REASONABLE AND WILL
LEAVE IN THE FORECAST. OTHERWISE...THE MAIN STORY WILL BE THE
ADVECTION OF THE COLDEST AIR THE REGION HAS OBSERVED IN YEARS.
850MB TEMPS WILL FALL INTO THE -25C TO -35C RANGE MY 12Z MON WHICH
WILL BRING IN SURFACE TEMPS FROM 30 BELOW OVER NORTH-CENTRAL
WISCONSIN TO ABOUT 15 BELOW AT THE LAKE MICHIGAN SHORELINE.
COMBINED WITH WINDS GUSTING TO 25 TO 30 MPH...PROJECTED WIND CHILLS
WILL FALL INTO THE 40 TO 55 DEGREES BELOW ZERO RANGE. EASTERN
SECTIONS MAY NOT REACH WIND CHILL WARNING CRITERIA UNTIL AFTER
MIDNIGHT...BUT THEY WILL BE FALLING RAPIDLY THROUGH THE EVENING...SO
WILL LEAVE THE WARNING START TIMES ALONE TO INCLUDE THE ADVISORY
RAMP UP TIME.
MONDAY...THE POLAR VORTEX WILL BE EXITING NORTHEAST WISCONSIN EARLY
IN THE MORNING AND WILL LEAVE A SMALL CHANCE OVER DOOR COUNTY TO
ACCOUNT FOR THAT. SHOULD SEE A PERIOD OF DECREASING CLOUDS UNTIL
MID AND HIGH CLOUDS SLIDE IN FROM THE NORTH DURING THE AFTERNOON.
NOT SURE HOW MUCH OF THESE CLOUDS WILL HOLD TOGETHER...SO WILL KEEP
SKIES IN THE PARTLY CLOUDY RANGE. ARCTIC HIGH PRESSURE WILL SLIDE
SOUTHEAST TOWARDS THE CENTRAL PLAINS WHICH SHOULD KEEP A TIGHT
PRESSURE GRADIENT IN PLACE. COMBINED WITH TEMPERATURES IN THE
NEGATIVE TEENS BELOW ZERO FOR HIGHS...WIND CHILLS WILL REMAIN IN THE
35 TO 45 DEGREES BELOW ZERO RANGE. WIND CHILL WARNINGS WILL
CONTINUE AS A RESULT.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 204 PM CST SUN JAN 5 2014
THE BITTER COLD REGIME OF ARCTIC AIR WILL STUBBORNLY DIMINISH
THIS WEEK AS THE UPPER FLOW TURNS MORE ZONAL WITH THE INTRODUCTION
OF WESTERLY PACIFIC FLOW AND MILDER CONDITIONS BY NEXT WEEKEND.
EVEN THOUGH THE CENTER OF THE POLAR VORTEX IS LIFTING NORTHEAST OF
THE AREA MONDAY NIGHT INTO EARLY TUESDAY...BITTER COLD AIR MASS
LEFT IN ITS WAKE COMBINED WITH WEST WINDS 10 TO 20 MPH WILL
CONTINUE TO PRODUCE WARNING WIND CHILL NUMBERS THROUGH A GOOD
PORTION OF TUESDAY BEFORE SUBSIDING TO ADVISORY CRITERIA IN THE
AFTERNOON.
HIGH PRESSURE RIDGE BEGINS TO SETTLES OVER THE AREA LATER TUESDAY
AFTERNOON INTO TUESDAY NIGHT. EVEN THOUGH 850 TEMPS BEGIN TO
MODIFY...EXPECTED CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPS TO
PLUMMET WELL BELOW ZERO AGAIN. DEPENDING ON WINDS...PARTS OF THE
THE AREA MAY STILL WARRANT WIND CHILL ADVISORY HEADLINES. THE COLD
HIGH PRESSURE REMAINS SETTLED OVER THE REGION WEDNESDAY NIGHT AND
THURSDAY FOR CONTINUED BELOW NORMAL SUB ZERO TEMPERATURES. A WEAK
SYSTEM IS PROGGED TO PASS SOUTH OF THE AREA WEDNESDAY NIGHT AND
THURSDAY...HAS TRENDED SOUTH LEAVING THE AREA MORE IN THE COLD
AIR MASS.
WAA PATTERN BEGINS IN EARNEST LATER THURSDAY INTO FRIDAY WITH
TEMPERATURES APPROACHING THE FREEZING MARK FOR THE WEEKEND. DUE
TO THE ZONAL FLOW...MODELS ARE PRODUCING DIFFERENT SOLUTIONS WITH
TIMING OF WEAK SHORT WAVES PASSING OVER OR NEAR THE GREAT LAKES
REGION FRIDAY INTO SUNDAY. USUALLY THE PACIFIC SYSTEMS ARE ON THE
DRY SIDE BUT WITH H850 TEMPERATURES ABOVE ZERO THIS WEEKEND...PCPN
TYPE ISSUES WILL INCREASE.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1118 PM CST SUN JAN 5 2014
ARCTIC AIR BECOMING ESTABLISHED ACRS THE AREA. COULD SEE SOME SCT
MVFR CIGS AS DEEP VORTEX SLIDES ACRS THE AREA LATE TNGT/EARLY MON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
UPDATE.........SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
829 PM PST TUE JAN 7 2014
.UPDATE...
RADAR AND SURFACE REPORTS INDICATE SOME LIGHT RAIN NEAR THE OREGON
BORDER JUST TO THE NORTHWEST OF THE SURPRISE VALLEY. THE 00Z
GFS/NAM AND 3KM HRRR SUGGEST SOME LIGHT SHOWERS OVERNIGHT FOR THE
SURPRISE VALLEY AND FAR NORTHWEST NV OVERNIGHT. SO UPDATED
FORECAST TO REFLECT THESE LATEST TRENDS. OTHERWISE VARIABLE CLOUDS
AND GENERALLY LIGHT WINDS EXCEPT ON RIDGES WHERE GUSTS TO 50 MPH
ARE EXPECTED. THE WINDS WERE GUSTING TO 70 MPH ABOVE 14000 FEET
IN THE WHITE MOUNTAINS. HOHMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 224 PM PST TUE JAN 7 2014/
SYNOPSIS...
A SERIES OF WEAK DISTURBANCES BRUSH THE REGION THIS WEEK
WITH LITTLE TO NO PRECIPITATION EXPECTED THROUGH WEDNESDAY. A
QUICK MOVING FRONT MAY PROVIDE RAIN AND SNOW SHOWERS THURSDAY WITH
ANOTHER LOW PRESSURE SYSTEM BRINGING ADDITIONAL CHANCES FOR RAIN AND
SNOW TO THE REGION ON SATURDAY.
SHORT TERM...
A SERIES OF WEAK DISTURBANCES WILL PASS THROUGH THE EASTERN SIERRA
AND WESTERN NEVADA THIS WEEK WITH VARYING CHANCES FOR PRECIPITATION
WITH EACH WAVE. THE NEXT WAVE WILL BRUSH THROUGH THE PACIFIC
NORTHWEST ON WEDNESDAY BRINGING AN INCREASE IN WINDS ACROSS NORTHERN
LASSEN AND NORTHERN WASHOE COUNTIES. UNFORTUNATELY PRECIPITATION
CHANCES WILL REMAIN NORTH AND EAST OF NEVADA WITH THIS SYSTEM.
THE NEXT QUICK MOVING SYSTEM WILL DROP THROUGH THE SIERRA AND
WESTERN NEVADA ON THURSDAY BRINGING BREEZY WINDS AND INCREASED
POTENTIAL FOR PRECIPITATION. WEST TO SOUTHWEST WINDS WILL INCREASE
AHEAD OF THE COLD FRONT WITH GUSTS AROUND 30 MPH FOR THE LOWER
VALLEYS AND GUSTS BETWEEN 50-60 MPH LIKELY FOR THE RIDGES. THE COLD
FRONT WILL ALSO BRING SNOW LEVELS DOWN TO AROUND 5000 FEET NEAR
INTERSTATE 80 AND AS LOW AS 3500 FEET NEAR THE OREGON BORDER. THE
BEST CHANCES FOR PRECIPITATION WILL REMAIN NORTH OF INTERSTATE 80,
BUT FORECASTER CONFIDENCE REMAINS MEDIUM WITH QPF AS THE NAM AND GFS
DIFFER DRASTICALLY FROM EACH OTHER. THE NAM FORECAST REMAINS DRY
WHILE THE GFS STILL BRINGS PRECIPITATION THROUGH THE REGION WITH THE
COLD FRONT ON THURSDAY. THIS RESULTED IN LITTLE CHANGE FOR THE
ONGOING QPF FORECAST WITH QPF AMOUNTS LESS THEN 0.10" AREAWIDE.
SNOW IS POSSIBLE DOWN TO VALLEY FLOORS BUT LITTLE ACCUMULATION IS
EXPECTED AS THE SYSTEM MOVES THROUGH QUICKLY.
MODELS ARE IN GOOD AGREEMENT WITH THE EXIT OF THE SHORTWAVE BY
THURSDAY AFTERNOON, BUT RESIDUAL MOISTURE AND NORTHEAST UPSLOPE FLOW
MAY RESULT IN SOME ISOLATED SHOWERS, ESPECIALLY SOUTH OF INTERSTATE
80 ALONG THE SIERRA. THE RIDGE QUICKLY RETURNS ON FRIDAY WITH
INCREASING TEMPERATURES AND DRIER CONDITIONS FORECAST. EKL
LONG TERM...SATURDAY THROUGH TUESDAY...
OVERALL FORECAST REMAINS LARGELY UNCHANGED WITH MODERATE CONFIDENCE
IN A SYSTEM IMPACTING THE SIERRA AND WESTERN NEVADA SATURDAY INTO
SUNDAY, HOWEVER CONFIDENCE IS LOWER IN THE EXACT TRACK AND TIMING OF
THIS SYSTEM. IN ANY EVENT, WINDS WILL INCREASE SATURDAY, ESPECIALLY
NORTH OF INTERSTATE 80, WITH A DECENT SURFACE GRADIENT IN PLACE AND
40-60 KTS AT 700 MB. HAVE INCREASED WINDS IN THE FORECAST TO REFLECT
THIS.
THERE IS PLENTY OF MOISTURE AND A DECENT JET ASSOCIATED WITH THE
SYSTEM AS IT MOVES INTO THE PACIFIC NORTHWEST COAST, BUT STILL
VARIATION IN HOW FAR SOUTH THE JET WILL DROP SOUTH. YESTERDAY, THE
GFS KEPT THE JET WELL TO THE NORTH, OVER SOUTHERN OREGON/IDAHO, BUT
MOST RECENT RUNS IS BRINGING IT FARTHER SOUTH ACROSS NORTHERN AND
CENTRAL NEVADA. THE EC HAS CONSISTENTLY BEEN BRINGING THE JET INTO
CENTRAL CA/NV, BUT THE JET STRUCTURE IS NOT AS FAVORABLE FOR LARGE
SCALE LIFT IN THE LATEST RUNS. THE OTHER PROBLEM IS THIS SYSTEM IS
LACKING ORGANIZATION AND DYNAMICS BY THE TIME IT REACHES THE SIERRA
AND NORTHWEST NEVADA, SO WILL CONTINUE WITH JUST CHANCES FOR
PRECIPITATION UNTIL CONFIDENCE INCREASES.
FOLLOWING THIS WAVE, THE RIDGE OF HIGH PRESSURE REBUILDS OVER THE
WEST COAST AND APPEARS TO REMAIN ANCHORED THERE THROUGHOUT NEXT
WEEK. THIS WILL DEFLECT THE STORM TRACK NORTHWARD AND KEEP THE
SIERRA AND WESTERN NEVADA DRY. DJ
AVIATION...
TRANQUIL WEATHER CONDITIONS WITH SCATTERED TO BROKEN MID AND HIGH
LEVEL CLOUDS TO CONTINUE THROUGH 00Z THURSDAY. WEST SOUTHWEST WINDS
AROUND 25 KTS AT 10K FEET THROUGH THIS EVENING WITH GUSTS UP TO 15
KTS AT VALLEY TERMINALS.
FAST MOVING SYSTEM TO IMPACT AREAS MAINLY NORTH OF HIGHWAY 50
WEDNESDAY NIGHT INTO THURSDAY WITH LIGHT SHOWERS AND MODERATE
CHANCES FOR MVFR CIGS/VIS. SNOW LEVELS WILL BE BETWEEN 4500-5500
FEET MSL, SO A MIX OF RAIN AND SNOW IS POSSIBLE AT MOST AREA
AIRPORTS. ANY ACCUMULATION WILL BE LIMITED DUE TO THE FAST STORM
MOTION.
WINDS TO INCREASE FRIDAY INTO SATURDAY WITH A SECOND, STRONGER
SYSTEM POSSIBLE THIS WEEKEND. DJ
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
Area Forecast Discussion
National Weather Service Lincoln IL
334 AM CST Wed Jan 8 2014
.DISCUSSION...
ISSUED 159 AM CST Wed Jan 8 2014
High pressure ridge to the NW and to the SE...but Central Illinois
is in a bit of a weak spot of the ridge that will result in some
low chance pops for today. Other issues with the forecast are the
general warming trend through Day 7...and a couple of precip
chances...tonight and into tomorrow... and Friday into the first
portion of the weekend. Current weather map is dominated by rather
weak sfc systems overall with a deep low NE of Hudson Bay. Deep
cold air over the Great Lakes and NE slowly making its way east,
with warmer temperatures in the SW. Previously NWrly flow becoming
more zonal and will set up todays chances for precip.
SHORT TERM...Today and tomorrow...
High temps finally making it back to double digits above zero as
the airmass shifts once again. Though a southerly component is
returning to sfc winds on the back side of the southeastern
high in the southern half of the state...pressure gradient in the weak
spot in the ridge is all but non existent and the winds will
remain light in most locations through tonight. Quasi
boundary/weak convergence at the sfc contributing to some weak,
albeit persistent frontogenetic forcing for Central Illinois.
Locating exactly where this band of snowfall will set up is
extraordinarily difficult. HRRR is furthest north...NAM further
south and the RUC/RAPP right in the middle. Pops for this
afternoon across the nrn half of the CWA as a result with
generally light snowfall amounts listed. As the high pressure to
the southeast continues to slide to the east...a southerly
component returns to the sfc tomorrow and more warm air ushered
into the FA. Tonight and into tomorrow, a system will move out of
the SW but collide with the colder air in place over Central
Illinois and bring another quick chance of snow...with best
chances on Thursday. Accumulations should generally be less than
an inch. At the end of the snow, as the system comes to an
end...ice crystals are lost aloft and FZDZ chances will move into
the western half of the state. Overnight tomorrow night the
flurry/freezing drizzle chances may linger a bit through the night.
LONG TERM...Friday through Tuesday...
Temperatures should be climbing above zero across Central Illinois
for Friday and into the weekend. Another system moving in Friday
will be a bit problematic in the first portion of the day while
sfc temps are below freezing and a deep layer of warm air is in
place aloft as the precip starts. Should that profile
maintain...will be a mix of rain and freezing rain until the temps
rebound. After 18z, dominated by rain in ILX CWA. Friday
night...will see the best chances for rain...ending from nw to se
on Saturday early as the system has slowed considerably in the
last 2 synoptic runs. Next major wave aloft has major differences
in track and timing...with the ECMWF looking like the prev 00z GFS
and tracking the sfc system southeast of the Ohio River Valley.
GFS is far enough south that it never impacts the CWA. The new GFS
is actually dry, keeping the majority of the energy to the north
and just allowing generally warmer temperatures, at least through
Day 7, and a drier forecast.
HJS
&&
.AVIATION...
ISSUED 1152 PM CST Tue Jan 7 2014
Weak low pressure will push across central IL the rest of the
night, leading a cold front across IL. Wind forecasts have low
confidence this round due to the frontal boundary directly over
the top of SPI, DEC and possibly CMI for much of the night and
into Wed morning. The PIA and BMI areas should see winds become
northerly in response to the low and frontal circulations. Clouds
will begin to fill-in toward morning as overrunning lift creates
mid-level clouds and areas of virga into the morning. Snow chances
will increase by mid-day Wed for PIA, as a band of forcing for
precip pushes across central IL centered across our northern
counties, including PIA and BMI - with CMI on the southern fringes
of precip Wed aftn.
A break in the precip is expected by mid evening and continuing
until Thursday for a return push of snows from the southwest.
MVFR clouds are likely to develop during any snows tomorrow, and
expand to the southern terminals after the snows Wed eve.
Shimon
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1140 PM EST TUE JAN 7 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 329 PM EST TUE JAN 7 2014
DANGEROUSLY COLD AIR WILL FINALLY MOVE OUT OF THE GREAT LAKES REGION
AND HIGH TEMPERATURES ON WEDNESDAY WILL BE IN THE TEENS.
TEMPERATURES WILL CONTINUE TO MODERATE AND HIGHS ABOVE FREEZING ARE
EXPECTED FRIDAY THROUGH MONDAY. SOME RAIN OR FREEZING RAIN MAY
ACCOMPANY THE WARM UP FROM LATE FRIDAY INTO EARLY SATURDAY.
&&
.UPDATE...
ISSUED AT 832 PM EST TUE JAN 7 2014
WE HAVE FRESHENED UP THE FCST THIS EVENING...MAINLY TO TWEAK TEMPS
A BIT AS SOME LOCATIONS HAVE DROPPED BELOW THEIR FCST MINS. TEMP
TRENDS HAVE BEEN ALL OVER THE PLACE THIS EVENING ACROSS THE CWFA.
THE WARMEST TEMPS HAVE BEEN FOUND ALONG THE LAKESHORE AS EXPECTED.
THE NRN INLAND LOCATIONS HAVE REMAINED UP A LITTLE...WHILE THE SRN
ROW OF COUNTIES REMAIN NEAR OR SLIGHTLY BELOW ZERO WITHOUT THE
INFLUENCE FROM LAKE MICHIGAN.
MODEL TRENDS OVERNIGHT ARE ALL OVER THE PLACE ALSO. THE NAM AND
GFS WANT TO SLOWLY WARM TEMPS FOR THE MOST PART...WHILE SHORT TERM
HI RES GUIDANCE LIKE THE HRRR RUC DROP TEMPS PRETTY GOOD. WE HAVE
TO BELIEVE THAT TEMPS SHOULD DROP A LITTLE AS WIND DIMINISH
TONIGHT. AREAS THAT POTENTIALLY CLEAR OUT LIKE THE FAR SOUTH WITH
LESS INFLUENCE FROM LAKE MICHIGAN WILL HAVE A BETTER CHC OF
DROPPING A FEW DEGREES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 329 PM EST TUE JAN 7 2014
WILL MAKE THE TRANSITION AT THIS TIME FROM WARNINGS TO ADVISORIES AS
GRADUAL IMPROVEMENT IN WIND CHILLS AND EXTENT OF SNOW AND BLOWING
SNOW WILL BE TAKING PLACE TONIGHT AND WEDNESDAY. WILL DOWNGRADE TO
A WINTER WEATHER ADVISORY ALONG THE LAKESHORE PLUS KENT COUNTY FOR A
COMBINATION OF LIGHT SNOW SHOWERS AND WIND CHILLS NEAR 10 BELOW.
ELSEWHERE WILL DOWNGRADE THE WIND CHILL WARNING TO A WIND CHILL
ADVISORY FOR WIND CHILLS OF 10 TO 20 BELOW.
THE COLDEST WIND CHILL READINGS FOR TONIGHT SHOULD OCCUR THIS
EVENING BEFORE THE WINDS DIMINISH. CURRENT WIND CHILLS HAVE
RECOVERED TO 5 TO 15 BELOW DOWNWIND OF LK MI AND TO 20 TO 25 ALONG
THE I-94 CORRIDOR. THESE VALUES WILL REMAIN COMMON FOR THE NEXT FEW
HOURS BEFORE NUDGING UP A FEW DEGREES.
VISIBILITIES AT THE LAKESHORE HAVE IMPROVED A TAD BUT MANY SITES ARE
STILL UNDER ONE MILE. LAKE EFFECT ECHOES HAVE LOOKED GENERALLY WEAK
TODAY WITH INVERSION HEIGHTS ONLY AROUND 4500 FT. BUFKIT PROFILES
SHOW THE DGZ WHICH IS CURRENTLY NEAR THE GROUND LIFTING BACK UP INTO
THE CLOUD LAYER TONIGHT AS SLIGHT WARMING TAKES PLACE. DECENT LIFT
IS INDICATED IN THE DGZ AS WELL. THIS IMPLIES THAT LAKE EFFECT SNOW
INTENSITY MAY INCREASE AGAIN THIS EVENING THROUGH EARLY WEDNESDAY...
OR AT LEAST CHANGE FROM SMALL/FINE FLAKES TO FLUFFY DENDRITES THAT
ACCUMULATE MORE EFFICIENTLY. THE LAKE EFFECT SNOW WILL GRADUALLY END
ON WEDNESDAY AFTERNOON AND EVENING AS SFC HIGH PRESSURE MOVES IN.
A LIMITING FACTOR FOR LAKE EFFECT IS THAT ICE COVERAGE ON LK MI IS
INCREASING WHICH MEANS SHORTER FETCH LENGTHS AND PARCEL RESIDENCE
TIMES. UNFORTUNATELY THE EXACT EXTENT OF THE ICE COVERAGE ON THE
LAKE IS UNCLEAR AT THIS TIME DUE TO THE EXTENSIVE CLOUD COVER. WEB
CAMS ALONG THE SHORE DO REVEAL CONSIDERABLE ICE HOWEVER.
THE SET UP LOOKS GOOD FOR VERY COLD TEMPS ON WEDNESDAY NIGHT AS
CLEARING SKIES AND LIGHT WINDS COUPLED WITH DEEP/FRESH SNOWPACK LEAD
TO IDEAL RADIATIONAL COOLING. SOME LIGHT SNOW IS POSSIBLE LATE
THURSDAY AND THURSDAY NIGHT RELATED TO WEAK ISENTROPIC LIFT.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 329 PM EST TUE JAN 7 2014
TEMPERATURES ARE LOOKING WARMER THROUGH THE EXTENDED PERIOD AND WITH
THOSE WARMER TEMPERATURES WILL COME SOME P-TYPE ISSUES.
A HIGH AMPLITUDE TROUGH WILL FROM THE MIDDLE OF THE COUNTRY TOWARD
THE GREAT LAKES FRIDAY. ISENTROPIC LIFT AHEAD OF THE TROUGH WILL
RESULT IN PCPN DEVELOPMENT. LOW TEMPERATURES FRIDAY NIGHT ARE
EXPECTED NEAR TO JUST BELOW FREEZING. FORECAST SOUNDINGS POINT
TOWARD MORE RAIN THAN SNOW DEVELOPMENT. EVEN IF TEMPERATURES ARE
JUST ABOVE FREEZING NEAR THE SURFACE...GROUND-LEVEL TEMPERATURES
WILL LIKELY BE AT OR BELOW FREEZING. FREEZING RAIN SEEMS LIKE A REAL
POSSIBILITY FRIDAY NIGHT.
AFTER THE TROUGH PASSES THROUGH EARLY SATURDAY THE COLUMN COOLS
ENOUGH THAT SNOW WILL PROBABLY BE THE MAIN P-TYPE. SFC TEMPS IN THE
UPPER 30S WOULD ALSO LIKELY PRECLUDE FREEZING RAIN.
ANOTHER TROUGH IS PROGD TO MOVE THROUGH SUNDAY NIGHT/MONDAY FOLLOWED
BY ANOTHER MONDAY NIGHT/TUESDAY. EACH WILL BRING ANOTHER SHOT OF
COOLER AIR...BUT NOT FRIGID LIKELY WE/VE SEEN RECENTLY. WE/LL BE
LOOKING AT SNOW SHOWERS SUNDAY NIGHT THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1140 PM EST TUE JAN 7 2014
SNOW SHOWERS WILL CONTINUE TO BRING OF MVFR/IFR VSBY/CIGS TO MKG
AND GRR THROUGH EARLY AFTERNOON BEFORE ENOUGH DRY AIR MOVES IN TO
CLEAR THE SKIES. THE I-94 TAF SITES ARE ON THE EDGE OF THE
CLOUDS...AZO HAS ONCE AGAIN GONE CLEAR...BTL WILL DO SO SHORTLY...
AS WILL JXN. MVFR CIGS WILL MOVE INTO THE I-94 TAF ONCE AGAIN...BY
12-14Z.
&&
.MARINE...
ISSUED AT 329 PM EST TUE JAN 7 2014
WILL CANCEL THE GALE AND HEAVY FREEZING SPRAY WARNINGS WITH WINDS
GRADUALLY SUBSIDING TONIGHT AND WEDNESDAY.
&&
.HYDROLOGY...
ISSUED AT 417 PM EST TUE JAN 7 2014
HYDRO CONCERNS ARE RELATIVELY MINIMAL IN THE SHORT TERM. RIVERS ARE
LOCKED IN OR GRADUALLY FALLING IN THE VERY COLD AIR. THE FLOOD
ADVISORY FOR THE FLAT RIVER AT SMYRNA WAS CANCELED MONDAY NIGHT. THE
WHITE RIVER AT WHITEHALL WAS EXHIBITING A SHARP RISE UNTIL CRESTING
THIS MORNING. IT HAS SINCE LEVELED OFF.
RIVERS WILL CONTINUE GAINING ICE COVERAGE AND THICKNESS THROUGH
THURSDAY. A WARM UP IS ON THE WAY FOR FRIDAY THROUGH EARLY NEXT
WEEK. HIGHS ABOVE FREEZING IN THE 30S TO NEAR 40 ARE EXPECTED
ALONG WITH A MIX OF RAIN AND SNOW FRIDAY AND SATURDAY. AT THIS
POINT WE DO NOT ANTICIPATE ISSUES WITH ICE JAMMING AND FLOODING
WITH THIS MINOR WARMUP. EVEN SO..RESIDENTS WHO LIVE ON RIVER BANKS
SHOULD CONTINUE TO WATCH FOR ANY ICE MOVEMENT WHICH COULD LEAD TO
ICE JAMS AND RISES IN RIVER LEVELS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 9 AM EST WEDNESDAY FOR MIZ037-043-
050-056-057-064-071.
WIND CHILL ADVISORY UNTIL 9 AM EST WEDNESDAY FOR MIZ038>040-
044>046-051-052-058-059-065>067-072>074.
LM...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR LMZ844>849.
&&
$$
UPDATE...NJJ
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...93
AVIATION...WDM
HYDROLOGY...HOVING/WALTON
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1006 PM CST TUE JAN 7 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 350 PM CST TUE JAN 7 2014
TEMPERATURES HAVE WARMED BACK ABOVE ZERO FOR MUCH OF THE AREA TODAY
THANKS TO SUNNY SKIES AND OUR SOMEWHAT OLD AND NON-PRISTINE SNOWPACK
WHICH HAS ALLOWED US TO MIX TO AROUND 925 MB. BUT OUR STAY ABOVE
ZERO WILL BE SHORT LIVED WITH PERHAPS THE COLDEST NIGHT OF THIS
COLD AIR OUTBREAK BEING POSSIBLE TONIGHT...ESPECIALLY FOR
WRN/CENTRAL MN. THE CULPRIT FOR THE COLD NIGHT TONIGHT IS THE 1030MB
HIGH UP IN SASKATCHEWAN THIS AFTERNOON THAT WILL BE SETTLING OVER MN
TONIGHT. THIS WILL GIVE US OUR FIRST GOOD OPPORTUNITY TO DECOUPLE
THE BOUNDARY LAYER UNDER MOSTLY CLEAR SKIES...SETTING UP IDEAL
RADIATIONAL COOLING CONDITIONS. THE ONLY POTENTIAL ISSUE? A STRIP OF
MID LEVEL CLOUDS THAT STRETCHES FROM THE TWIN CITIES BACK INTO
SOUTHEAST SASKATCHEWAN. A QUICK PEEK OUT THE WINDOW SHOWS THAT IR
SATELLITE IS EMBELLISHING THE THICKNESS OF THE CLOUD COVER A
BIT...AS IT IS A RATHER THIN ALTO CU DECK...SO WILL STICK WITH THE
IDEA OF THE RAP WITH THIS AREA OF CLOUDS DISSIPATING THIS EVENING AS
A REINFORCING SHOT OF SUBSIDENCE AND DRY AIR MOVES IN. WITH CLEARING
SKIES EXPECTED...FAVORED THE FORECAST TOWARD A BLEND OF THE BIAS
CORRECTED MAV/MET...WHICH RESULTED IN LOWS BETWEEN 28 AND 33 DEGREES
BELOW ZERO BASICALLY NORTHWEST OF A BENSON TO KANABEC LINE. UNDER
SIMILAR CONDITIONS THIS MORNING...LADYSMITH WAS ABLE TO DROP DOWN TO
-30...SO AS LONG AS THE MID LEVEL CLOUDS DON/T STICK AROUND FOR TOO
LONG...AM FAIRLY CONFIDENT IN SEEING TEMPS OF -30 OR COLDER IN OUR
TRADITIONAL COLD SPOTS LIKE BENSON AND LITTLE FALLS.
UNFORTUNATELY...WITH TEMPERATURES THIS COLD...IT WILL NOT TAKE MUCH
WIND TO SEE APPARENT TEMPERATURES CRASH TO BETWEEN 25 BELOW ZERO IN
SOUTHERN MN TO THE LOWER 40S BELOW ZERO ACROSS CENTRAL MN. WIND
SPEEDS ARE FORECAST TO BE 5 MPH OR LESS...SO WOULD HAVE PREFERRED TO
GO WITH NO WIND CHILL HEADLINES /DUE TO LACK OF WINDS/...BUT AFTER
COLLABORATION WITH NEIGHBORS HAVE GONE AHEAD AND ISSUED ANOTHER WIND
CHILL ADVISORY FOR TONIGHT INTO WEDNESDAY MORNING. HAVE APPARENT
TEMPERATURES WHERE FORECAST LOWS ARE CURRENTLY PROGGED TO BE COOLER
THAN -25 GETTING DOWN TO AROUND 40 BELOW...WHICH IS INTO WARNING
CRITERIA. HOWEVER...WITH WINDS EXPECTED TO BE LIGHT...DECIDED TO
STICK WITH THE ADVISORY...ESPECIALLY CONSIDERING THIS WILL BE
NOTHING LIKE WHAT WAS SEEN FROM SUNDAY NIGHT INTO MONDAY NIGHT.
FOR WEDNESDAY...WITH THE HIGH DIRECTLY OVERHEAD...WE WILL NOT SEE
MUCH MIXING...AS EVIDENCED BY NAM BUFR SOUNDINGS WHICH SHOW THE
BOUNDARY LAYER TODAY MIXING UP TO BETWEEN 900 AND 925 MB...BUT ONLY
MAKING IT TO 950MB OR LESS FOR WEDNESDAY. THIS WILL RESULT IN
WEDNESDAY BEING COOLER THAN WHAT WE ARE SEEING TODAY. AFTER BLENDING
IN BIAS CORRECTED MOS AND RAW MODEL DATA...ENDED UP WITH FORECAST
HIGHS ON WEDNESDAY ABOUT 2 TO 5 DEGREES COOLER THAN WHAT WE HAD BEEN
GOING WITH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 PM CST TUE JAN 7 2014
HIGH PRESSURE WILL KEEP THE UPPER MIDWEST DRY AND COLD FOR A FEW
MORE DAYS UNTIL SOUTHERLY FLOW BRINGS INCREASED MOISTURE...WARMER
TEMPERATURES...AND PRECIP CHANCES THIS WEEKEND.
AT THE START OF THE PERIOD HIGH PRESSURE WILL BE CENTERED ALONG THE
MN/WI BORDER...WITH CLEAR SKIES AND LIGHT WINDS SUPPORTING LOW
TEMPERATURES IN THE NEGATIVE 20S ACROSS WESTERN WISCONSIN AND
EASTERN MINNESOTA. THESE LOW TEMPERATURES SHOULD CLOSELY MIRROR
TONIGHTS. FARTHER WEST WARM AIR ADVECTION WILL WARM TEMPERATURES
OVERNIGHT...SO HAVE A NON- DIURNAL TREND IN PLACE. A PWAT FORECAST
OFF THE GFS 07.12 HAS 0.5 INCHES RETURNING ACROSS MINNESOTA...AND
AN INCH OF PRECIPITABLE WATER SOUTHEAST ACROSS THE WISCONSIN RIVER
VALLEY. THIS NORTHWARD MOISTURE FLUX IS AHEAD OF A LONGWAVE TROUGH
THAT WILL MOVE EASTWARD AND A WIDESPREAD AREA OF PRECIP ACROSS THE
EASTERN CONUS. AS OF NOW THE MAJORITY OF THE PRECIP WILL FALL EAST
OF I-35...SO CONTINUED WITH CHANCE POPS ACROSS THE SOUTHEASTERN
PORTIONS OF THE CWA. TEMPERATURES WILL MODERATE
CONSIDERABLY...WITH NEAR 30 FOR FRIDAY AND SATURDAY. SUNDAYS HIGHS
ARE CURRENTLY FORECAST TO BE IN THE MID 30S...BUT COULD SEE LOW
40S DEPENDING ON THE TIMING OF THE H850 THERMAL RIDGE.
CURRENTLY...THE EC 07.12 IS SLOWER THAN THE GFS AND WOULD FAVOR A
WARMER SOLUTION. FOR NOW HAVE A BLENDED GUIDANCE GIVEN THE
UNCERTAINTY...BUT THE POTENTIAL CERTAINLY EXISTS FOR A WARM
SUNDAY. ANOTHER CHANCE FOR SNOW EXISTS BEHIND THE COLD FRONT
SUNDAY NIGHT INTO MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 955 PM CST TUE JAN 7 2014
SOME HIGHER LEVEL MID CLOUD DROPPING SOUTH OVER THE AREA DURING
THE NIGHT. SMALL CHANCE OF MVFR CIGS OR VSBYS BRUSHING THE FAR
NORTHWEST CWA LATER TONIGHT. WILL MENTION SOME BR AT KAXN WITH
CENTER OF HIGH CLOSE BY BY 12Z. OTHERWISE AREA WILL REMAIN VFR.
LIGHT W-NW WINDS BECOMING LGT/VRBL OVER THE WEST LATE TONIGHT
SHIFTING EAST INTO WEDNESDAY. WINDS SHOULD GRADUALLY BECOME MORE
SOUTHERLY LATE AFTERNOON OVER THE WEST AS CENTER OF THE HIGH MOVES
EAST.
KMSP...HIGH CONFIDENCE FORECAST. VFR THROUGH PERIOD. LIGHT WINDS.
/OUTLOOK FOR KMSP/
THU...VFR. WINDS S 10 KTS.
FRI...VFR. CHC MVFR/-SN/-IP. WIND SSW 10 KTS.
SAT...VFR. WINDS SW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR MNZ041>045-
047>070-073>078-082>085-091>093.
WI...WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS HASTINGS NE
345 AM CST WED JAN 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST WED JAN 8 2014
MAIN FORECAST CONCERNS WILL BE SNOW CHANCES TODAY AND FREEZING
DRIZZLE CHANCES LATE TONIGHT...AS WELL AS TEMPERATURES.
RADAR AND OBSERVATIONS HAVE SOME LIGHT SNOW THAT HAS DEVELOPED
MAINLY NORTH OF INTERSTATE 80 EARLY THIS MORNING. SO FAR
OBSERVATIONS HAVE NOT HAD VERY LOW VISIBILITIES WITH THE SNOW.
A COUPLE OF UPPER LEVEL WAVES WILL BE MOVING THROUGH THE REGION
TODAY AND TONIGHT. THE SNOW THAT HAS DEVELOPED ACROSS THE NORTHERN
PORTION OF THE AREA IS EXPECTED TO SPREAD TO THE SOUTH EARLY THIS
MORNING. THE NAM AND GFS ARE SIMILAR IN DEVELOPING A BAND OF SNOW
ACROSS THE NORTH THEN MOVING IT TOWARD THE SOUTHEAST THIS MORNING
AND THE PRECIPITATION SHOULD BE EXITING THE AREA DURING THE
AFTERNOON. THE ONLY CONCERN IS THE HRRR AND 4KM WRF BOTH ARE MUCH
WEAKER WITH PRECIPITATION. THE HRRR DOES NOT GO OUT VERY FAR INTO
THE MORNING HOURS AT THIS TIME. WILL CONTINUE WITH THE SNOW WITH
THE BEST CHANCES FOR SNOW WILL BE DURING THE MORNING HOURS AND
MAINLY TO THE NORTH AND EAST OF THE TRI-CITIES. SNOWFALL AMOUNTS
SHOULD BE A HALF INCH TO AROUND AN INCH ACROSS NEBRASKA AND LESS
THAN A HALF INCH IN NORTH CENTRAL KANSAS. THE SNOW SHOULD COME TO
AN END FROM WEST TO EAST LATE THIS AFTERNOON.
THE MAIN CONCERN FOR TONIGHT WILL BE LATE TONIGHT. AFTER THE SNOW
MOVES OUT THE MID LEVELS DRY OUT SOME AND THE DENDRITIC LAYER IS
DRY..BUT LATE TONIGHT THERE IS A SHALLOW MOIST LAYER THAT IS COLD.
THIS COULD BRING A CHANCE FOR SOME LIGHT FREEZING DRIZZLE. THE
PREVIOUS FORECAST HAD JUST THE FAR SOUTHEAST. FORECAST SOUNDINGS
INDICATE THE BEST CHANCE WILL CONTINUE TO BE IN THE FAR SOUTHEAST. A
LITTLE FURTHER TO THE NORTHWEST THERE IS A SHALLOW LAYER OF MOISTURE
BUT IT IS FAIRLY SHORT LIVED BEFORE IT STARTS TO DRY OUT. WILL HAVE
TO WATCH TO SEE IF THAT MOIST LAYER CONTINUES OR WHETHER IT WILL DRY
OUT.
CURRENT TEMPERATURES ARE IN THE 20S ACROSS THE FORECAST
AREA...WHICH IS VERY NEAR TO THE FORECAST HIGHS FOR TOMORROW.
STILL EXPECT THE TEMPERATURES TO DROP OFF TOWARD MORNING SO WILL
LEAVE FORECAST HIGHS AS THEY ARE FOR NOW. LOWS TONIGHT WILL DIP
DOWN TO A FEW DEGREES EITHER SIDE OF 10 DEGREES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 AM CST WED JAN 8 2014
GUIDANCE SUGGESTS QUASI-ZONAL FLOW WILL BE NOTED ACROSS MUCH OF
THE CONUS TO START THE LONG TERM FORECAST PERIOD ON
THURSDAY...ALTHOUGH A MID LEVEL SHORTWAVE WILL ALSO BE MOVING INTO
THE NORTHWESTERN CONUS BY 12Z THURSDAY. GUIDANCE FROM THE
NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL SUGGEST THIS MID
LEVEL SHORTWAVE WILL MOVE SOUTHEAST INTO THE FOUR CORNERS REGION
BY 12Z FRIDAY...INTO CENTRAL TEXAS BY 00Z SATURDAY...AND NEAR THE
LOWER MISSISSIPPI VALLEY BY 12Z SATURDAY. AT THE SURFACE AN AREA
OF LOW BAROMETRIC PRESSURE IS EXPECTED TO BE REALIZED OVER THE
PANHANDLE OF TEXAS BY 12Z FRIDAY. THIS SURFACE LOW IS THEN
EXPECTED TO QUICKLY MOVE NORTHEAST AND NEAR THE GREAT LAKES REGION
BY 12Z SATURDAY.
MID LEVEL THERMAL ADVECTION AND INCREASING TROPOSPHERIC MOISTURE
SHOULD PROMOTE PRECIPITATION PRODUCTION ACROSS MUCH OF THE SOUTHERN
PLAINS THURSDAY NIGHT...WITH THE PRIMARY AXIS OF MID LEVEL OMEGA
THEN EXPECTED TO MOVE INTO POTIONS OF THE MID TO LOWER MISSISSIPPI
VALLEY DURING THE DAY FRIDAY...A SOLUTION SUPPORTED BY QPF FIELDS
FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN. ALL THAT BEING
SAID...MODEL GUIDANCE CONTINUES TO SUGGEST THE WEST/NORTHWESTERN
PERIPHERY OF THIS OMEGA AXIS WILL CLIP PORTIONS OF THE
CENTRAL PLAINS DURING THE DAY FRIDAY...WITH THE SOUTHEASTERN HALF
OUR CWA STILL EXPECTED TO OBSERVE MEASURABLE PRECIPITATION DURING
THE DAY FRIDAY. GIVEN THE MODEL AGREEMENT...AS WELL AS MODEL
CONSISTENCY THROUGH THE PAST 24 HOURS...OPTED TO KEEP POPS GOING
ACROSS ROUGHLY THE SOUTHEASTERN HALF OF THE CWA 12Z FRIDAY THROUGH
00Z SATURDAY...AND ACTUALLY INCREASED POPS ACROSS THE SOUTHEASTERN
ONE-THIRD OF THE CWA INTO THE 40-50% RANGE.
GUIDANCE ALSO SUGGESTS SURFACE TEMPERATURES ACROSS OUR CWA ON
FRIDAY WILL START IN THE LOWER 20S...BUT EVENTUALLY RISE RISE INTO
THE 30S TO NEAR 40 FRIDAY AFTERNOON. FORECAST PROXIMITY SOUNDINGS
FROM THE ACROSS OUR CWA...PER THE NAM AND OPERATIONAL GFS...CONTINUE
TO SUGGEST A SIGNIFICANT WARM LAYER WILL EXIST...PRIMARILY BETWEEN
750MB AND 900MB...THROUGH 15Z OR 18Z FRIDAY. AS A RESULT...FREEZING
RAIN CONTINUES TO LOOK LIKE A POSSIBILITY GENERALLY ALONG AND
SOUTHEAST OF LINE FROM PHILLIPSBURG...TO GRAND ISLAND AND
FULLERTON...WITH CHANCES FOR SUCH ACTIVITY INCREASING AS ONE MOVES
SOUTHEAST ACROSS THE CWA. THESE SAME FORECAST PROXIMITY SOUNDINGS
ALSO SUGGEST WE WILL LIKELY BE WAITING FOR THE MID TO LOWER
TROPOSPHERE TO SATURATE UNTIL AROUND 12Z FRIDAY...THUS IS WHY THE
AFOREMENTIONED POPS WERE NOT INTRODUCED UNTIL 12Z FRIDAY. IN
ADDITION...BASED ON GUIDANCE...IT APPEARS THE TEMPERATURE THROUGH
MOST LOCATIONS ACROSS THE CWA WILL RISE ABOVE FREEZING BY 18Z AND AS
A RESULT...FREEZING RAIN WORDING COMES TO AN END IN THE OFFICIAL
FORECAST BY 18Z FRIDAY...WITH RAIN THEN EXPECTED WITH ANY PRECIPITATION
THROUGH THE REST OF THE DAY.
TAKING AN AVERAGE OF THE NAM...OPERATIONAL GFS...EC...SREF-MEAN
AND WPC GUIDANCE PROVIDES LIQUID PRECIPITATION AMOUNTS OF A COUPLE
HUNDREDTHS OF AN INCH NEAR THE TRI-CITIES...TO AROUND 0.10"
FARTHER SOUTHEAST DURING THE 12-18Z FRIDAY TIMEFRAME. ADDITIONAL
LIQUID PRECIPITATION AMOUNTS OF 0.01-0.05" ARE THEN ANTICIPATED
ACROSS OUR EAST/SOUTHEAST FRIDAY AFTERNOON. GIVEN ALL THIS IT
CERTAINLY SEEMS AS THOUGH WE ARE HEADING TOWARDS AN ADVISORY-
WORTHY EVENT ON FRIDAY WITH A FEW HUNDREDTHS TO PERHAPS A TENTH OF
AN INCH OF ICING APPEARING POSSIBLE ACROSS THE SOUTHEASTERN HALF
OF THE CWA. AS MENTIONED YESTERDAY...WE ARE STILL ABOUT 24 HOURS
FROM THIS MID LEVEL SHORTWAVE ACTUALLY MAKING LANDFALL OVER THE
NORTHWESTERN CONUS...AT WHICH TIME SUFFICIENT SAMPLING BY THE
UPPER AIR NETWORK SHOULD ALLOW MODEL GUIDANCE TO REALLY NAIL DOWN
THE TRACK AND TIMING OF THIS SYSTEM. PROVIDED THE CONTINUED
UNCERTAINTY OF THIS SYSTEM...WILL CONTINUE TO KEEP THE HWO
SOMEWHAT VAGUE WITH RESPECT TO ICING AMOUNTS...BUT CERTAINLY
MAINTAIN THE MENTION OF FREEZING RAIN FRIDAY MORNING WITH THE
POTENTIAL FOR DIFFICULT DRIVING CONDITIONS.
AS ALREADY MENTIONED...IT APPEARS WE WILL BE WAITING FOR THE MID
TO LOWER TROPOSPHERE TO SATURATE THROUGH ABOUT 12Z FRIDAY. THAT
BEING SAID...PERSISTENT SOUTHERLY LOW LEVEL FLOW AND RESULTANT LOW
LEVEL MOISTURE FLUX INTO THE AREA SHOULD ALLOW FOR RISING DEW
POINT VALUES ACROSS MUCH OF OUR CWA THURSDAY NIGHT INTO FRIDAY
MORNING. GUIDANCE FROM THE NAM...OPERATIONAL GFS AND EC ALL
SUGGEST 0-0.5KM RH VALUES WILL CLIMB INTO THE 90-100% RANGE ACROSS
ROUGHLY THE SOUTHEASTERN ONE-THIRD OF OUR CWA BETWEEN 06Z AND 12Z
FRIDAY. THESE SAME SETS OF GUIDANCE ALSO SUGGEST LOW LEVEL
TURBULENT MIXING ON THE ORDER OF 15-20KTS WILL BE PRESENT DURING
THE SAME TIME PERIOD. GIVEN ALL THIS...WILL CONTINUE THE MENTION
OF FREEZING DRIZZLE...ROUGHLY ALONG AND SOUTHEAST OF A LINE FROM
PHILLIPSBURG TO HEBRON....IN THE HWO AND GRIDS 06-12Z FRIDAY.
BEYOND THE DAY FRIDAY...THE MAJORITY OF THE LONG TERM FORECAST
PERIOD REMAINS DRY...WITH THE ONLY EXCEPTION BEING SUNDAY INTO
SUNDAY NIGHT. BOTH THE OPERATIONAL GFS AND EC SUGGEST A MID LEVEL
SHORTWAVE WILL MOVE ACROSS THE REGION DURING THIS TIME PERIOD AND
ALLBLEND RESPONDED BY PROVIDING ~20% POPS TO MUCH OF THE CWA. THESE
POPS WERE LEFT UNCHANGED FOR THE MOST PART.
A WARM LOW LEVEL AIRMASS IS EXPECTED TO MAINTAIN ITSELF ACROSS
THE CENTRAL PLAINS THROUGHOUT THE LONG TERM FORECAST PERIOD...WITH
AFTERNOON HIGHS IN THE 30S TO NEAR 40 THURSDAY AND FRIDAY...AND IN
THE 40S TO NEAR 50 SATURDAY ONWARD. OVERNIGHT LOWS IN THE TEENS
AND 20S WILL ALSO LIKELY BE COMMON DURING THE LONG TERM FORECAST
PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1124 PM CST TUE JAN 7 2014
ALREADY SEEING SOME RETURNS ON RADAR TO THE NORTH OF THE KGRI
TERMINAL AND AS THE NIGHT PROGRESSES THE SNOW SHOULD MOVE TO THE
SOUTH AND INTO THE KGRI TERMINAL. BROUGHT IT IN A LITTLE EARLIER
THAN BEFORE AND HAVE SOME CONCERN THAT IT MIGHT BE EARLIER YET.
THE BEST CHANCE FOR SNOW AND LOWER CEILINGS AND VISIBILITIES WILL
BE DURING THE MORNING HOURS. SNOW SHOULD END BY LATER THIS
AFTERNOON BUT CEILINGS WILL REMAIN MVFR THROUGH THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
343 AM CST WED JAN 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CST WED JAN 8 2014
ARCTIC HIGH PRESSURE...ANGLED NORTHWEST TO SOUTHEAST ACROSS NORTH
DAKOTA WILL DRIFT SOUTHEAST INTO SRN WISCONSIN BY THURSDAY
MORNING. SFC LOW PRESSURE WILL BUILD ACROSS THE CANADIAN ROCKIES
AND INTO WRN ALBERTA BY THIS TIME SETTING UP A SOUTH AND
SOUTHWEST LOW LEVEL WIND FIELD ACROSS THE FCST AREA. MOISTURE IS
EXPECTED TO REMAIN TRAPPED UNDER THE WRN PERIPHERY OF THE ARCTIC
RIDGE MAINTAINING EXTENSIVE CLOUDINESS TODAY AND TONIGHT.
IT LOOKS LIKE THE NORTHWEST ZONES COULD SEE SOME CLEARING BY
THURSDAY MORNING WHILE THE REST OF THE FCST AREA REMAINS
OVERCAST. THE LOW CLOUDS APPEAR TO BE OVERDONE IN THE NAM...GFS
AND RAP MODELS BUT GIVEN THE UPSLOPE EAST AND SOUTHEAST WINDS
DEVELOPING OR FORECAST TO DEVELOP...THESE MODELS MAY BE TOO FAST.
OVERALL THE FORECAST CALLS FOR THE CLOUDS TO REMAIN LOCKED IN
TODAY AND TONIGHT.
THE LIGHT SNOW FORECAST APPEARS TO BE ON TRACK WITH NO SFC OBS
REPORTING LESS THAN 1 MILE VISIBILITY OVERNIGHT AND RADAR
SUGGESTS THE AREA OF SNOW IS MOVING OFF TO THE EAST. THE FORECAST
CONTINUES LIGHT SNOW THIS MORNING WITH FLURRIES THROUGH EARLY
AFTERNOON. NOTE THAT SEVERAL MODELS FORECAST 2 INCH SNOW TOTALS
IN PLACES BUT A LOOK AT THE NEDOR CAMS INDICATES LESS THAN AN
INCH ACCUMULATIONS AT ALL LOCATIONS VISIBLE AND NONE OF THE CAMS
SUGGESTED MODERATE SNOW WAS FALLING.
HIGH TEMPERATURES TODAY SHOULD RISE INTO THE UPPER TEENS NEAR
HIGHWAY 281 WITH WARMER READINGS RISING TO THE LOWER 30S WESTWARD
ACROSS SOUTHWESTERN NEB AND THE ERN PANHANDLE. LOWS TONIGHT FALL
INTO TEENS. A 30 TO 40 KT LOW LEVEL JET WILL BE DEVELOPING
TONIGHT AND THIS IN COMBINATION WITH THE CLOUD COVER SHOULD KEEP
LOWS ON THE WARM SIDE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 AM CST WED JAN 8 2014
ROLLER COAST OF TEMPS CONTINUE WITH HIGHS GOING UP FOR THURSDAY
AS WAA AHEAD OF THE NEXT APPROACHING WEAK TROUGH. MOSTLY SUNNY
SKIES AND HIGHS IN THE MID 30S EAST TO LOWER 40S SW. WILL NEED TO
MONITOR EXISTING SNOW AS AN INCH OR SO MAY CAUSE TEMPS TO BE
LOWER THAN CURRENT FORECAST BY A FEW DEGREES...HOWEVER SW WINDS
IN THE 15 TO 25 MPH RANGE WHICH WILL HELP IN MIXING THE LOWER
LEVELS.
UPPER LEVEL TROUGH TO MOVE ACROSS THE HIGH PLAINS ON FRIDAY. SFC
LOW TRACKS FROM NW TX TO THE NE...WHICH IS IN GOOD AGREEMENT WITH
THE MODELS. LIFT/PRECIP DOES SEE MINOR PATH ADJUSTMENTS...HOWEVER
MODELS ALL KEEP IT TO THE SE OF THE CWA. AS WINDS BECOME NW
DURING THE DAY...A BRIEF MIXING WILL STILL HELP TO WARM TEMPS TO
SEASONAL NORMS...POSSIBLY EVEN WARMER.
UPPER LEVEL TROUGH WILL PUSH EAST BY SATURDAY WITH STRONG WAA.
TEMPS FRIDAY NIGHT COULD BE EARLY...PENDING SOME MINOR TIMING
ADJUSTMENTS TO ARRIVAL OF WARMER AIR. EITHER WAY...WARMER FOR
SATURDAY WITH 40S FOR MOST AREAS...AND EVEN 50 FOR SW.
BY SATURDAY NIGHT THE NEXT SHORT WAVE WILL BE PUSHING ACROSS THE
ROCKIES. INCREASING CLOUDS SHOULD HOLD TEMPS WELL ABOVE
NORMAL...WITH MID 20S TO AROUND 30 EXPECTED SUNDAY MORN. AS THE
WAVE MOVES ACROSS SUNDAY MODELS HAVE FAIRLY STRONG WINDS
ALOFT...WITH 850 MB WINDS NEAR 50 KTS. MODELS DO NOT MIX ALL THIS
DOWN...HOWEVER DO EXPECT A WINDY DAY AND WILL MONITOR FOR
POTENTIAL ADVISORY CONDITIONS. ANOTHER ISSUE WILL BE SOME WEAK
LIFT WITH THE WAVE. MOISTURE IS LIMITED INITIALLY AND WILL BE A
TOP DOWN SATURATION. ANOTHER ISSUE IS TEMPS WITH THIS WAVE. STILL
SEEING SOME WARM AIR AT THE SURFACE WITH GUIDANCE IN AGREEMENT
WITH HIGHS WARMING INTO THE 40S. LONG RANGE SOUNDINGS WOULD
SUGGEST SNOW EARLY IN THE DAY...WITH WARMING TEMPS AND A CHANGE
OVER TO RAIN.
FOR NEXT WEEK...RIDGE AMPLIFIES OUT WEST...ALTHOUGH SOME MODELS
DISAGREEMENT WITH THE STRENGTH. GFS IS WEAKER WITH THE RIDGE AND
ALLOWS ANOTHER CLIPPER TO BACK ACROSS THE HIGH PLAINS ON
TUESDAY...WHILE THE EC IS A LITTLE STRONG WITH THE RIDGE AND
KEEPS THE CLIPPER TO THE NORTHEAST. PENDING HOW FAR TO THE SW THE
CLIPPER DOES PUSHES...WILL PLAY A BIG PART TO THE FORECAST. THUS
FOR EARLY NEXT WEEK FORECAST HAS LOW CONFIDENCE. THOUGHT IS FOR
THE WARMER/DRIER AIR TO WIN...AS MOST OF THE WINTER THE BULK OF
THE WAVES HAVE GONE EAST OF THE AREA. THAT SAID...COOLER AIR AND
POSSIBLY SOME LIGHT PRECIP /FLURRIES OR SPRINKLES/ CAN NOT BE
RULED OUT FOR EARLY NEXT WEEK AND WILL NEED TO BE WATCHED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1122 PM CST TUE JAN 7 2014
WIDESPREAD CEILINGS LESS THAN 3000 FEET AGL ARE EXPECTED IN
NORTHERN NEBRASKA WITH AREAS OF 1000 FEET OR LOWER. THE COVERAGE
OF THE INSTRUMENT CEILINGS WILL BE LESS THAN 30 PERCENT.
THEREFORE WE WILL NOT INCLUDE IT IN THE POINT FORECAST FOR VTN.
VISIBILITY BELOW 3SM IS LIKELY AT LEAST INTERMITTENTLY. THE
INTERMITTENT INSTRUMENT VISIBILITY CONTINUE AS LATE AS 11Z. AREAS
OF LIGHT SNOW AND VISIBILITY BELOW 3SM ARE EXPECTED NORTH OF
BBW-AIA.
IN THE REST OF CENTRAL AND SOUTHWEST NEBRASKA...CEILINGS AND
VISIBILITY WILL BE ABOVE 3000 FEET AGL AND 3SM OR HIGHER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1028 PM CST TUE JAN 7 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 822 PM CST TUE JAN 7 2014
NOW THAT THE CORE OF THE COLD IS OFF TO OUR E...TEMPS WL BE DRIVEN
BY MORE THAN JUST ADVECTION. SML LEAF-LIKE PATCH OF HIGH AC
COMING ACRS THE SRN PART OF THE FCST AREA AS HOLDING TEMPS UP.
THAT SHOULD EXIT THE SE PART OF THE AREA ARND MIDNIGHT. ADJUSTED
HOURLY TEMP GRIDS TO ACCOUNT FOR THE FEATURE. IT MAY BE HOLDING
TEMPS UP NOW...BUT SHOULD DEPART IN TIME TO NOT HAVE A SIG IMPACT
ON MINS.
WHERE SKIES WERE CLEAR...DECRG SFC PRESSURE GRADIENT HAS ALLOWED
WINDS TO DIE OFF IN THE TYPICAL COLDS SPOTS IN NRN WI...AND TEMPS
HAVE TANKED. LNL ALREADY DOWN AS LOW AS 26 BELOW. EXPECT SITES
LIKE D25/RHI/TKV/RRL/EGV TO FOLLOW DURING THE NIGHT. TWEAKED MINS
DOWN SOME IN THESE AREAS.
WINDS WERE GENERALLY MARGINAL FOR A WIND CHILL ADVISORY. THOSE
SITES THAT STILL HAD WIND WERE MOSTLY NOT MEETING CRITERIA. BUT
TEMPS WL BE FALLING TO VERY COLD READINGS...AND DON/T THINK MOST
SITES WL BE CALM ALL NGT. WITH MIN WIND SPEED CRITERIA FOR A WIND
CHILL HEADLINE NOW ONLY 4 MPH...THERE WL CERTAINLY BE TIMES WHEN
CRITERIA ARE MET ACRS ALMOST THE ENTIRE AREA BY MORNING. AND THE
FEW SPOTS THAT STAY CALM MAY WELL BE APPROACHING 30 BELOW AIR
TEMPERATURES. SO...WL LEAVE THE ADVISORY INTACT.
UPDATED GRIDS AND DERIVED ZONES/AFM/PFM ALREADY OUT.
UPDATED WSW AND HWO TO FOLLOW SHORTLY.
&&
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 240 PM CST TUE JAN 7 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE CENTERED OVER THE GULF COAST...AND A RIDGE AXIS EXTENDING
NORTHEAST ACROSS THE PLAINS TO CENTRAL CANADA. AREAS OF LOW CLOUD
COVER CONTINUE TO FLOW SOUTHEAST AHEAD OF THE RIDGE AXIS FROM SOUTHERN
CANADA AND NORTHERN MINNESOTA AND INTO WISCONSIN...BUT THE LATEST
SATELLITE IMAGES SHOW THE STRATUS DISSIPATING AS IT MOVES INTO
NORTH-CENTRAL WISCONSIN. WITH PARTLY TO MOSTLY SUNNY
CONDITIONS...TEMPERATURES AND WIND CHILLS HAVE WARMED INTO THE
SINGLE DIGITS BELOW ZERO AND BETWEEN 20 TO 30 DEGREES BELOW ZERO
RESPECTIVELY. AS HIGH PRESSURE SHIFTS EAST INTO THE REGION OVER THE
NEXT 24 HOURS...TEMPS AND WIND CHILLS REMAIN THE MAIN FORECAST
CONCERNS...FOLLOWED BY CLOUDS.
TONIGHT...THE SURFACE RIDGE AXIS OVER THE NORTHERN MISSISSIPPI
VALLEY AND NORTHERN PLAINS WILL MOVE EAST TOWARDS THE STATE. AREAS OF LOW
STRATUS UPSTREAM WILL CONTINUE TO FLOW SOUTHEAST AHEAD OF THE
SURFACE HIGH WHICH MAKES CLOUD FORECAST PROBLEMATIC. DO NOT THINK
MODELS HAVE A GOOD HANDLE ON THIS CLOUD COVER...BUT DO INDICATE
DIMINISHING LOW LEVEL RH THAT WOULD POINT TOWARDS THIS CLOUD COVER
BREAKING UP. SO GENERALLY WENT WITH MOSTLY CLEAR TO PARTLY CLOUDY
CONDITIONS FOR THE EVENING...WITH A LITTLE HIGHER CLOUD COVER OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN...THEN SKY CONDITIONS TURNING
MOSTLY CLEAR EVERYWHERE OVERNIGHT. DUE TO THE INCOMING SURFACE
HIGH...WINDS WILL BE SUBSIDING TONIGHT...AND SOME POTENTIAL FOR
DECOUPLING OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. LOW LEVEL
WINDS WILL BE RIGHT ON THE CUSP...AND IF THIS OCCURS...LOW TEMPS
WILL BE SEVERAL DEGREES COLDER THAN IN THE GOING FORECAST. AS A
RESULT...DID SIDE WITH THE COLDER GUIDANCE BUT DID NOT GO WITH THE
COLDEST SOLUTIONS IN CASE DECOUPLING DID NOT OCCUR. THIS WOULD
PLACE LOW TEMPS MAINLY BETWEEN 10 AND 20 BELOW...WITH A FEW COLDER
SPOTS OVER N-C WISCONSIN...AND A FEW WARMER SPOTS NEAR THE LAKE
SHORE. WIND CHILLS WILL FALL TO 25 T0 35 DEGREES BELOW ZERO. WIND
CHILL ADVISORY HEADLINES WILL GO ON AS PLANNED...WITH THE CAVEAT
THAT SOME LOCATIONS MAY SEE A CALM WIND FOR A PERIOD LATE TONIGHT.
WEDNESDAY...HIGH PRESSURE WILL MOVE OVER THE AREA. TEMPERATURES
WILL CONTINUE THEIR SLOW MODERATION...AND WITH PLENTY OF
SUNSHINE...READINGS WILL RETURN TO THE SINGLE DIGITS ABOVE ZERO.
APPARENT TEMPS WILL RISE ABOVE ADVISORY CRITERIA BY LATE IN THE
MORNING...SO WILL RUN HEADLINES THROUGH 18Z.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 240 PM CST TUE JAN 7 2014
ARCTIC AIR MASS WITH SUB ZERO LOW TEMPERATURES WILL LINGER
WEDNESDAY NIGHT DUE TO ANTICIPATED CLEAR SKIES AND CALM WINDS UNDER
THE SURFACE HIGH PRESSURE SYSTEM.
ATTENTION THEN TURNS TO PCPN POTENTIAL LATE IN THE WEEK WITH THE
WAA FLOW. INITIAL WEAK SHORT WAVE PASSES JUST SOUTH OF THE AREA
THURSDAY INTO THURSDAY NIGHT. CONSIDERED ADDING A SLIGHT CHANCE OF
PCPN BUT UNSURE OF SATURATION FOR NOW. LATER SHIFTS CAN SOME ZL-
THURSDAY NIGHT IF WARRANTED.
MAIN SHORTWAVE TO PASS OVER LATER FRIDAY INTO FRIDAY EVENING WITH
PROGS INDICATED UP TO 0.25 WATER EQUIVALENT BY FRIDAY MIDNIGHT
OVER THE SOUTHEAST HALF OF THE FORECAST AREA. FORECAST SOUNDINGS
SUGGESTING A MIX OF ZR/S OVER MOST LOCATIONS AND THEREFORE HAS THE
POTENTIAL OF A HEADLINE FOR MIXED PCPN LATE THIS WEEK. HWO ALREADY
HIGHLIGHTING THIS CONCERN.
SURFACE RIDGE UNDER THE ZONAL FLOW REGIME TO END PCPN SATURDAY MORNING
WITH WAA PATTERN STARTING UP AGAIN SATURDAY NIGHT INTO SUNDAY. THE
FIRST IN A SERIES OF LOW PRESSURE SYSTEMS IS PROGGED TO TRACK
NORTH OF LAKE SUPERIOR LATE NEXT WEEKEND WILL DRAG A COOL FRONT
OVER THE AREA LATER SUNDAY INTO SUNDAY NIGHT...FOLLOWED WITH
ANOTHER CLIPPER SYSTEM NORTH OF THE REGION TOWARD TUESDAY. WILL
CONTINUE LOW END CHANCES OF PCPN WITH THE VARIOUS FROPAS.
FOR WHAT ITS WORTH...END PERIODS OF THE MEDIUM RANGE MODELS ARE
INDICATING SOME COLDER AIR TO WORK TOWARD THE GREAT LAKES REGION
LATE NEXT WEEKEND.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1025 PM CST TUE JAN 7 2014
GENERALLY GOOD FLIGHT CONDITIONS EXPECTED AS ARCTIC AIR DOMINATES
THE AREA. SC THAT WAS ACRS MN HAS MADE LITTLE PROGRESS TO THE
SE...BUT SOME SC HAS DRIFTED INTO THE FAR N FROM LAKE SUPERIOR.
THAT COULD BRUSH THROUGH RHI FOR A TIME...BUT THINK THE MVFR CIGS
WOULD BE BRIEF.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
UPDATE.........SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
342 AM PST WED JAN 8 2014
.DISCUSSION...AS OF 3:00 AM PST WEDNESDAY...PLENTY OF CLOUDS
ACROSS THE CWA THIS MORNING ALONG WITH A MORE PRONOUNCED WESTERLY
FLOW AT THE SURFACE WHICH HELPED TO PRODUCE A FEW AREAS OF
DRIZZLE. IN FACT, SFO ENDED UP REPORTING A TRACE OF RAINFALL CLOSE
TO MIDNIGHT MARKING THE FIRST TIME IN ABOUT 30 DAYS THAT ANY RAIN
HAS BEEN REPORTED THERE. WEBCAMS AND SURFACE OBS ALSO SHOWS SOME
POCKETS OF FOG ALONG WITH A REPORT DOWN TO A QUARTER OF A MILE
AROUND SANTA ROSA. IN MANY RESPECTS MANY OF THE OBS SEEM LIKE
WHAT WE WOULD USUALLY SEE DURING EARLY SUMMER "JUNE GLOOM"
MORNINGS AND NOT WHAT YOU WOULD EXPECT FOR JANUARY. THE ONSHORE
FLOW WILL HELP TO KEEP HIGHS ON THE COOLER SIDE -- LOOK FOR 50S
TO LOWER 60S AT THE COAST WITH 60S INLAND.
A SYSTEM FROM THE PACNW WILL DIVE TO THE SOUTHEAST ON THURSDAY.
PREVIOUS MODEL RUNS HAD BROUGHT THE FAR SOUTHERN AND WESTERN
EXTENT OF MOISTURE INTO THE NORTH BAY FOR THURSDAY. THAT LOOK
INCREASINGLY UNLIKELY AS THE LOW WILL SIMPLY BE TOO FAR TO THE
EAST. RAIN CHANCES WERE REMOVED FROM THE GRIDS. TEMPERATURES ON
THURSDAY WILL BE SIMILAR TO TODAY.
WARMER WEATHER WILL RETURN FOR FRIDAY AS 850 MB TEMPS INCREASE AND
A RIDGE OF HIGH PRESSURE BUILDS BACK TO OUR CWA. SOME INLAND SPOTS
WILL RETURN BACK TO THE LOWER 70S. COASTAL AREAS WILL LIKELY NOT
WARM AS MUCH DUE TO THE ONSHORE FLOW CONTINUING.
OVER THE WEEKEND THE STRONGEST PACIFIC SYSTEM OF THE WEEK MOVES TO
THE PACNW/BC COASTLINE. PROGS FOR SATURDAY HAVE BEEN IN FAIRLY
CONSISTENT BRINGING THE ASSOCIATED COLD FRONT INTO NORTHERN
CALIFORNIA DURING THE DAY. THE BULK OF THE MOISTURE WILL STAY
NORTH OF OUR CWA, BUT LOOKS INCREASINGLY LIKELY THAT THE FAR
SOUTHERN EXTENT WILL MAKE IT INTO THE NORTH BAY AND POSSIBLY AS
FAR SOUTH AS SANTA CRUZ COUNTY. POPS WERE INCREASE INTO THE HIGH
CHANCE CATEGORY FOR NAPA/SONOMA AND GENERALLY SLIGHT CHANCE FOR SF
BAY DOWN TO SANTA CRUZ. RAINFALL TOTALS WILL BE LOW AND RAIN
DURATION IS EXPECTED TO JUST BE FOR A FEW HOURS AS THE FRONT
QUICKLY ADVANCES. AROUND A TENTH CAN BE EXPECTED OVER THE NORTH
BAY AND A FEW HUNDREDTHS AROUND SF INTO SAN MATEO COUNTY.
AND AS QUICKLY AS THE RAIN CHANCES ARRIVE, THEY WILL END AS THE
STRONG RIDGE OFF THE COAST REBUILDS. INTERESTING TO NOTE THAT THE
MODELS ARE DEPICTING AN EXTREMELY AMPLIFIED LONGWAVE RIDGE
EXTENDING NEARLY TO THE ARCTIC CIRCLE BY THE END OF NEXT WEEK AS
THE COLD LOW REPOSITIONS ITSELF BACK NEAR HUDSON BAY WITH THE
RIDGE HERE EXTENDING FROM THE WEST COAST OF THE CONUS NORTH THROUGH
BC, YUKON TERRITORY AND ALASKA. AT THE SAME TIME THE SURFACE FLOW
WILL RETURN TO BEING OFFSHORE AND 850MB TEMPS WILL INCREASE UP TO
3 STANDARD DEVIATIONS ABOVE NORMAL. RECORD HIGHS WILL LIKELY BE
HIT NEXT WEEK -- POSSIBLY AT MANY SPOTS.
MJO FORECAST SHOWS VIRTUALLY NO MOVEMENT OVER THE NEXT TWO WEEKS
MAKING IT THAT MUCH HARDER FOR THE RIDGE TO BE UNDERCUT GOING INTO
AT LEAST THE 20TH OF JANUARY.
&&
.CLIMATE...IN A TYPICAL JANUARY, SAN FRANCISCO WOULD HAVE HIGHS 60
OR ABOVE 7 TIMES. WE HAVE ALREADY EQUALED THAT NUMBER FOR THE
MONTH.
MONTHLY RAINFALL TOTALS ARE SIMILAR FOR DECEMBER, JANUARY, AND
FEBRUARY FOR MOST OF OUR AREA. BY MARCH, THE EXPECTED AMOUNT
DECREASES BY ABOUT 25 PERCENT. IN APRIL WE USUALLY RECEIVE ONLY 5
TO 10 PERCENT OF OUR RAIN FOR THE YEAR. WE HAVE NOW GONE THROUGH
WHAT WOULD USUALLY BE OVER 40% OF OUR RAINFALL FOR THE WATER YEAR.
FOR THE WATER YEAR, BEN LOMOND HAS ONLY PICKED UP 2.39" WHICH IS
JUST 11 PERCENT OF NORMAL TO DATE. IN ORDER TO GET TO 100% BY THE END
OF JUNE, 48.09" WILL NEED TO FALL (OR MORE THAN 0.43" WOULD NEED TO
FALL EVERY DAY UNTIL THE END OF APRIL.)
&&
.AVIATION...AS OF 3:42 AM PST WEDNESDAY...A STORM SYSTEM
APPROACHING THE NORTHERN CA COASTLINE WILL CONTINUE TO BRING LIGHT
TO MODERATE ONSHORE FLOW AND ALLOW COASTAL LOW CLOUDS TO IMPACT
THE TERMINALS. LOW MVFR TO OCCASIONAL IFR CIGS WILL BE
PRESENT...MAINLY THROUGH THE SF BAY AREA...THROUGH 21Z. LOW
CONFIDENCE. THE HRRR AND WRF ARE THE ONLY SHORT TERM MODELS
HANDLING THE LOW CLOUDS CORRECTLY...WITH VERY PATCHY CIGS OVER THE
MONTEREY BAY AND NORTH BAY. AFTER A BRIEF BREAK IN THE
CLOUDINESS...LOW CLOUDS ARE FORECAST TO RETURN AS EARLY AS 02Z
THURSDAY. AGAIN VERY LOW CONFIDENCE FORECAST...ESPECIALLY WITH
REGARDS TO TIMING.
VICINITY OF KSFO...MVFR TO OCCASIONAL IFR CIGS POSSIBLE THROUGH
21Z...LOW CONFIDENCE. PATCHY DRIZZLE WILL BE POSSIBLE THROUGH THE
EARLY MORNING HOURS. OTHERWISE...MODERATE ONSHORE WINDS THIS
AFTERNOON AND A RETURN OF MVFR CIGS BETWEEN 03 AND 06Z THURSDAY.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...PATCHY MVFR CIGS WILL BE POSSIBLE
THROUGH 16Z. OTHERWISE...LIGHT TO MODERATE ONSHORE WINDS THIS
AFTERNOON WITH AN EARLY RETURN OF MVFR CIGS AROUND 02Z. LOW CONFIDENCE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: RILEY
CLIMATE: BELL
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
528 AM CST WED JAN 8 2014
.DISCUSSION...
332 AM CST
FORECAST CONCERNS THIS MORNING INCLUDE CONTINUED COLD TEMPERATURES
THROUGH THURSDAY MORNING...THE POTENTIAL FOR A LITTLE LIGHT SNOW
ACROSS THE FAR SOUTHERN CWA TODAY...THEN ANOTHER CHANCE OF SOME
LIGHT SNOW OR MIXED LIGHT SNOW/FREEZING DRIZZLE THURSDAY INTO
THURSDAY NIGHT. TEMPERATURES CLIMB ABOVE FREEZING FRIDAY WITH A
FAIRLY HIGH PROBABILITY FOR RAIN...PERHAPS BEGINNING AS SOME MIXED
PRECIP OR FREEZING RAIN FRIDAY MORNING.
WEAK HIGH PRESSURE RIDGE STRETCHES FROM THE NORTHERN PLAINS INTO THE
MIDWEST EARLY THIS MORNING...WITH ARCTIC AIR REMAINING IN PLACE
ACROSS THE AREA AND A SHARP BAROCLINIC BOUNDARY ALONG THE SOUTH EDGE
OF THE HIGH. LIGHT/CALM WINDS AND MAINLY CLEAR SKIES OVER DEEP SNOW
COVER HAVE ALLOWED OVERNIGHT TEMPS TO DROP INTO THE -10 TO -15
DEGREE RANGE ROUGHLY NORTH OF I-88...THOUGH WITH WIND CHILLS JUST
INTO THE NEGATIVE DOUBLE DIGITS IN A FEW SPOTS. MORE CLOUD COVER
ACROSS THE SOUTH NEAR THE BAROCLINIC ZONE HAS KEPT TEMPS JUST ABOVE
ZERO THERE. THIS ORIENTATION OF FRONTAL ZONE AND CLOUD COVER WILL
CONTINUE FOR ANOTHER 24 HOURS OR SO...KEEPING A FAIRLY LARGE
GRADIENT FROM COLDER TEMPS ACROSS FAR NORTHERN IL TO ONLY MODERATELY
COLD READINGS IN THE SOUTH. SO ONE MORE DAY OF SINGLE DIGIT ABOVE
ZERO HIGHS AND ONE MORE NIGHT OF SUB-ZERO MINS FOR THE NORTHERN
COUNTIES REMAINS BEFORE A LITTLE MORE ROBUST MODERATION TAKES HOLD
ON THURSDAY. GUIDANCE IN GOOD AGREEMENT WITH TEMPS ACROSS OUR
SOUTHERN COUNTIES INTO THURSDAY...WITH A LITTLE SPREAD ACROSS THE
NORTH WHERE A BLEND TOWARD THE COLDER OUTPUT WAS USED.
ACROSS OUR FAR SOUTHERN COUNTIES...MODELS REMAIN IN VERY GOOD
AGREEMENT IN DEVELOPING A NARROW SWATH OF LIGHT SNOW BY THIS
AFTERNOON...GENERALLY SOUTH OF THE STREATOR-KANKAKEE-DE MOTTE AREAS.
PRECIPITATION POTENTIAL WILL BE FOCUSED ALONG THE AFOREMENTIONED
BAROCLINIC ZONE AS A PAIR OF MID-LEVEL SHORT WAVES APPROACH TODAY...
WITH GUIDANCE DEPICTING AN AREA OF MODERATE FRONTOGENETIC FORCING
MOST NOTABLE IN THE 850-800MB LAYER. A LITTLE WEAKLY NEGATIVE EPV
NOTED ABOVE THE F-GEN LAYER INITIALLY FROM 800-750MB...THOUGH THIS
DOES NOT APPEAR TO PERSIST ONCE THE COLUMN BECOMES MORE SATURATED.
ISENTROPIC ASCENT IS FAIRLY WEEK WITH MOST OF THE LIFT PROVIDED BY
AGEOSTROPHIC RESPONSE TO THE F-GEN...WITH LOW CONDENSATION PRESSURE
DEFICITS LIMITED TO SAME NARROW SWATH AS SEEN IN THE 280-285 K
SURFACES. OVERALL...FORCING IS NOT TOO IMPRESSIVE WITH THIS
DISTURBANCE WITH WEAK OMEGA WHICH IS GENERALLY CENTERED BELOW BETTER
CRYSTAL/FLAKE GROWTH TEMPERATURE LAYER ALOFT. QPF LIMITED TO A FEW
HUNDREDTHS ACROSS OUR FARTHEST SOUTH TIER OF COUNTIES...WITH
NAM/GFS/RAP COBB DATA SUGGESTING SNOW/LIQUID RATIOS OF AROUND 15/1
YIELDING ABOUT A HALF INCH OR LESS OF SNOWFALL THIS AFTERNOON/EARLY
EVENING. LIGHT SNOW SHOULD END EARLY IN THE EVENING...AS RESPONSIBLE
PAIR OF MID-LEVEL WAVES RACE OFF TO THE EAST...AND SURFACE HIGH
PRESSURE BUBBLE ONCE AGAIN BUILDS ACROSS WI/NORTHERN IL.
SURFACE HIGH PRESSURE MOVES QUICKLY OFF TO THE EAST OF THE AREA
THURSDAY MORNING...WITH LOW LEVEL FLOW BECOMING SOUTH AS ANOTHER
SHORT WAVE TROUGH OF PACIFIC ORIGIN PROPAGATES ACROSS THE REGION.
THIS BACKED FLOW INDUCES A REGION OF ISENTROPIC ASCENT AND
WARM/MOIST ADVECTION WHICH PRODUCES SATURATION AND PRECIPITATION
DEVELOPMENT BY THURSDAY AFTERNOON. MODEL FORECAST SOUNDINGS INDICATE
THERE MAY BE SOME TROUBLE SATURATING MID-LEVEL ICE NUCLEATION
TEMPERATURE LAYER...ESPECIALLY ACROSS THE NORTHWEST HALF OF THE
FORECAST AREA. THIS CAUSES SOME UNCERTAINTY IN P-TYPE WITH THE
POTENTIAL FOR SOME LIGHT FREEZING RAIN/DRIZZLE TO MIX WITH LIGHT
SNOW DURING THE DAY. MODEL SOUNDINGS INDICATE SOMEWHAT DEEPER
SATURATION ACROSS THE EASTERN 1/2 OF THE CWA THURSDAY WHICH SUGGESTS
A BETTER CHANCE OF SNOW THERE. SNOW/LIQUID RATIOS WILL BE LOWER AS
THE AIR MASS MODERATES...WITH PERHAPS A 10/1 OR 12/1 RATIO YIELDING
PERHAPS AN INCH OR SO OF SNOW ACROSS OUR SOUTHEAST COUNTIES.
MID-LEVELS DRY OUT ACROSS THE AREA THURSDAY EVENING HOWEVER ATOP
MOIST LOW LEVELS...WHICH MAY KEEP THE THREAT OF SOME LIGHT FREEZING
DRIZZLE AROUND AREA-WIDE THURSDAY NIGHT.
AMPLIFICATION OF LARGE-SCALE UPPER TROUGH TAKES PLACE ACROSS THE
WESTERN CONUS THURSDAY NIGHT...INCREASING LOW LEVEL SOUTH WINDS
ACROSS THE MIDWEST THURSDAY NIGHT INTO SATURDAY. TEMPERATURES LOOK
TO RISE ABOVE FREEZING FRIDAY...WITH RAIN DEVELOPING INTO THE REGION
BY FRIDAY AFTERNOON. LOWS EARLY FRIDAY WILL BE IN THE 20S ACROSS THE
FORECAST AREA...WITH THE POTENTIAL FOR SOME LIGHT PRECIPITATION IN
THE FORM OF LIGHT FREEZING RAIN OR DRIZZLE BEFORE CHANGING TO RAIN
AS SURFACE TEMPS WARM DURING THE LATE MORNING/MID-DAY HOURS. FAR
NORTHERN ILLINOIS NEAR THE WISCONSIN BORDER WILL BE THE LAST TO
CLIMB ABOVE FREEZING...AND THUS HAVE PERHAPS THE GREATEST CHANCE OF
RECEIVING SOME FREEZING RAIN. THE BULK OF THE MEASURABLE RAIN SHOULD
OCCUR LATER FRIDAY AFTERNOON AND NIGHT HOWEVER...WITH TEMPS ABOVE
FREEZING. AS HAS BEEN MENTIONED...SNOW MELT AND RAINFALL WILL
LIKELY LEAD TO SOME RISES ON AREA RIVERS AND THE POTENTIAL FOR
BREAK-UP ICE JAM FLOODING.
LONG-RANGE GUIDANCE INDICATES THIS UPPER TROUGH WILL BE PROGRESSIVE
WITH ITS ASSOCIATED SURFACE COLD FRONT MOVING ACROSS THE FORECAST
AREA EARLY IN THE DAY. MOST OF THE PRECIP OCCURS PRE-FRONTALLY WITH
THIS SYSTEM...WITH LITTLE QPF PRODUCED AFTER COLD FROPA. BRIEF
SHORT-WAVE RIDGING DEVELOPS SURFACE AND ALOFT SATURDAY NIGHT INTO
SUNDAY BEHIND THE DEPARTING SYSTEM...BEFORE ANOTHER PROGRESSIVE
UPPER TROUGH APPROACHES LATER SUNDAY NIGHT AND MONDAY. TEMPERATURES
REMAIN A BIT ABOVE NORMAL DURING THE PERIOD...WITH SOME LIGHT
RAIN/SNOW MIX INDICATED. SEASONABLY/NORMAL COLDER AIR RETURNS BEHIND
THE COLD FRONT TUESDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* NONE.
KREIN
//DISCUSSION...UPDATED 12Z...
A RIDGE OF HIGH PRESSURE MOVING ACROSS THE AREA WILL KEEP CLEAR
SKIES AND LGT/VRBL-CALM WINDS AT THE TERMINALS THROUGH THE
LATE THIS MORNING. A WEAK MID LEVEL DISTURBANCE WILL UNDERCUT THE
HIGH PRESSURE CROSSING THROUGH CNTRL IL/IN...SPREADING SOME MID
LEVEL CLOUDINESS. A REINFORCING AREA OF HIGH PRESSURE BUILDING OUT
OF THE NRN PLAINS TOMORROW AFTERNOON WILL KEEP WINDS GENERALLY
WLY-NWLY THROUGH THE DAY WITH SPEEDS REMAINING UNDER 10KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...SLIGHT CHANCE LIGHT SNOW OR FREEZING DRIZZLE.
MVFR LIKELY...IFR POSSIBLE.
FRIDAY...WINTRY MIX EARLY...BECOMING ALL RAIN. MVFR/IFR LIKELY.
SATURDAY...SLIGHT CHANCE OF RAIN/MVFR EARLY...THEN DRY/VFR.
SUNDAY...CHANCE OF SNOW LATE. MVFR POSSIBLE.
MONDAY...SLIGHT CHANCE OF SNOW EARLY. MVFR POSSIBLE.
TUESDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE.
KREIN
&&
.MARINE...
300 AM CST
DEEP LOW PRESSURE REMAINS OVER FAR NORTHERN QUEBEC WHILE HIGH
PRESSURE EXTENDS FROM THE NORTHERN PLAINS THROUGH THE SOUTHEASTERN
CONUS. THE HIGH PRESSURE WILL GRADUALLY BUILD EASTWARD...LEADING
TO THE BRISK WEST WINDS GIVING WAY TO LIGHTER AND MORE VARIABLE
WINDS AS THE HIGH PRESSURE BUILDS ACROSS LAKE MICHIGAN WEDNESDAY
NIGHT. AS THE HIGH MOVES OFF TO THE EAST ON THURSDAY///A TROUGH OF
LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS...LEADING TO
INCREASING SOUTHERLY WINDS OVER THE LAKE. WINDS SHOULD INCREASE TO
AROUND 30KT BY THURSDAY AS THE GRADIENT TIGHTENS OVER THE LAKE.
STRONG SOUTH WINDS WILL COVER THE LAKE UNTIL EARLY SATURDAY WHEN A
STRONG COLD FRONT WILL SWEEP ACROSS THE LAKE SHIFTING WINDS TO
WESTERLY.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
521 AM CST Wed Jan 8 2014
.DISCUSSION...
ISSUED 159 AM CST Wed Jan 8 2014
High pressure ridge to the NW and to the SE...but Central Illinois
is in a bit of a weak spot of the ridge that will result in some
low chance pops for today. Other issues with the forecast are the
general warming trend through Day 7...and a couple of precip
chances...tonight and into tomorrow... and Friday into the first
portion of the weekend. Current weather map is dominated by rather
weak sfc systems overall with a deep low NE of Hudson Bay. Deep
cold air over the Great Lakes and NE slowly making its way east,
with warmer temperatures in the SW. Previously NWrly flow becoming
more zonal and will set up todays chances for precip.
SHORT TERM...Today and tomorrow...
High temps finally making it back to double digits above zero as
the airmass shifts once again. Though a southerly component is
returning to sfc winds on the back side of the southeastern
high in the southern half of the state...pressure gradient in the weak
spot in the ridge is all but non existent and the winds will
remain light in most locations through tonight. Quasi
boundary/weak convergence at the sfc contributing to some weak,
albeit persistent frontogenetic forcing for Central Illinois.
Locating exactly where this band of snowfall will set up is
extraordinarily difficult. HRRR is furthest north...NAM further
south and the RUC/RAPP right in the middle. Pops for this
afternoon across the nrn half of the CWA as a result with
generally light snowfall amounts listed. As the high pressure to
the southeast continues to slide to the east...a southerly
component returns to the sfc tomorrow and more warm air ushered
into the FA. Tonight and into tomorrow, a system will move out of
the SW but collide with the colder air in place over Central
Illinois and bring another quick chance of snow...with best
chances on Thursday. Accumulations should generally be less than
an inch. At the end of the snow, as the system comes to an
end...ice crystals are lost aloft and FZDZ chances will move into
the western half of the state. Overnight tomorrow night the
flurry/freezing drizzle chances may linger a bit through the night.
LONG TERM...Friday through Tuesday...
Temperatures should be climbing above zero across Central Illinois
for Friday and into the weekend. Another system moving in Friday
will be a bit problematic in the first portion of the day while
sfc temps are below freezing and a deep layer of warm air is in
place aloft as the precip starts. Should that profile
maintain...will be a mix of rain and freezing rain until the temps
rebound. After 18z, dominated by rain in ILX CWA. Friday
night...will see the best chances for rain...ending from nw to se
on Saturday early as the system has slowed considerably in the
last 2 synoptic runs. Next major wave aloft has major differences
in track and timing...with the ECMWF looking like the prev 00z GFS
and tracking the sfc system southeast of the Ohio River Valley.
GFS is far enough south that it never impacts the CWA. The new GFS
is actually dry, keeping the majority of the energy to the north
and just allowing generally warmer temperatures, at least through
Day 7, and a drier forecast.
&&
.AVIATION...
ISSUED 510 AM CST Wed Jan 8 2014
Main forecast concern will be timing and coverage of light snow as
a weak frontal boundary remains across the area with mostly VFR
cigs expected thru 22z. Any snows that do develop later this
morning out to our west and makes it this far east will have the
potential to drop cigs briefly down to MVFR this evening. Otherwise,
look for cigs to lower to between 4500-6000 feet by later this
morning, with the potential for cigs to lower to 2500-3500 feet
in any light snow that may push across a terminal site. The snow
threat should exit east of our area after 02z with low VFR cigs
expected to prevail overnight. Surface winds will be variable in
direction, mostly from the northeast at less than 10 kts today and
then gradually veer more into an easterly direction tonight.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
652 AM CST WED JAN 8 2014
.UPDATE...
ISSUED AT 651 AM CST WED JAN 8 2014
KLNX RADAR IN VCP31 IS GROWING VERY QUIET WITH ECHO RETURNS
RAPIDLY DECREASING. IT APPEARS OUR WEAK UA DISTURBANCE IS EXITING
THE FORECAST AREA. A NEW FORECAST IS OUT FOR FLURRIES ENDING THIS
MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CST WED JAN 8 2014
ARCTIC HIGH PRESSURE...ANGLED NORTHWEST TO SOUTHEAST ACROSS NORTH
DAKOTA WILL DRIFT SOUTHEAST INTO SRN WISCONSIN BY THURSDAY
MORNING. SFC LOW PRESSURE WILL BUILD ACROSS THE CANADIAN ROCKIES
AND INTO WRN ALBERTA BY THIS TIME SETTING UP A SOUTH AND
SOUTHWEST LOW LEVEL WIND FIELD ACROSS THE FCST AREA. MOISTURE IS
EXPECTED TO REMAIN TRAPPED UNDER THE WRN PERIPHERY OF THE ARCTIC
RIDGE MAINTAINING EXTENSIVE CLOUDINESS TODAY AND TONIGHT.
IT LOOKS LIKE THE NORTHWEST ZONES COULD SEE SOME CLEARING BY
THURSDAY MORNING WHILE THE REST OF THE FCST AREA REMAINS
OVERCAST. THE LOW CLOUDS APPEAR TO BE OVERDONE IN THE NAM...GFS
AND RAP MODELS BUT GIVEN THE UPSLOPE EAST AND SOUTHEAST WINDS
DEVELOPING OR FORECAST TO DEVELOP...THESE MODELS MAY BE TOO FAST.
OVERALL THE FORECAST CALLS FOR THE CLOUDS TO REMAIN LOCKED IN
TODAY AND TONIGHT.
THE LIGHT SNOW FORECAST APPEARS TO BE ON TRACK WITH NO SFC OBS
REPORTING LESS THAN 1 MILE VISIBILITY OVERNIGHT AND RADAR
SUGGESTS THE AREA OF SNOW IS MOVING OFF TO THE EAST. THE FORECAST
CONTINUES LIGHT SNOW THIS MORNING WITH FLURRIES THROUGH EARLY
AFTERNOON. NOTE THAT SEVERAL MODELS FORECAST 2 INCH SNOW TOTALS
IN PLACES BUT A LOOK AT THE NEDOR CAMS INDICATES LESS THAN AN
INCH ACCUMULATIONS AT ALL LOCATIONS VISIBLE AND NONE OF THE CAMS
SUGGESTED MODERATE SNOW WAS FALLING.
HIGH TEMPERATURES TODAY SHOULD RISE INTO THE UPPER TEENS NEAR
HIGHWAY 281 WITH WARMER READINGS RISING TO THE LOWER 30S WESTWARD
ACROSS SOUTHWESTERN NEB AND THE ERN PANHANDLE. LOWS TONIGHT FALL
INTO TEENS. A 30 TO 40 KT LOW LEVEL JET WILL BE DEVELOPING
TONIGHT AND THIS IN COMBINATION WITH THE CLOUD COVER SHOULD KEEP
LOWS ON THE WARM SIDE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 AM CST WED JAN 8 2014
ROLLER COAST OF TEMPS CONTINUE WITH HIGHS GOING UP FOR THURSDAY
AS WAA AHEAD OF THE NEXT APPROACHING WEAK TROUGH. MOSTLY SUNNY
SKIES AND HIGHS IN THE MID 30S EAST TO LOWER 40S SW. WILL NEED TO
MONITOR EXISTING SNOW AS AN INCH OR SO MAY CAUSE TEMPS TO BE
LOWER THAN CURRENT FORECAST BY A FEW DEGREES...HOWEVER SW WINDS
IN THE 15 TO 25 MPH RANGE WHICH WILL HELP IN MIXING THE LOWER
LEVELS.
UPPER LEVEL TROUGH TO MOVE ACROSS THE HIGH PLAINS ON FRIDAY. SFC
LOW TRACKS FROM NW TX TO THE NE...WHICH IS IN GOOD AGREEMENT WITH
THE MODELS. LIFT/PRECIP DOES SEE MINOR PATH ADJUSTMENTS...HOWEVER
MODELS ALL KEEP IT TO THE SE OF THE CWA. AS WINDS BECOME NW
DURING THE DAY...A BRIEF MIXING WILL STILL HELP TO WARM TEMPS TO
SEASONAL NORMS...POSSIBLY EVEN WARMER.
UPPER LEVEL TROUGH WILL PUSH EAST BY SATURDAY WITH STRONG WAA.
TEMPS FRIDAY NIGHT COULD BE EARLY...PENDING SOME MINOR TIMING
ADJUSTMENTS TO ARRIVAL OF WARMER AIR. EITHER WAY...WARMER FOR
SATURDAY WITH 40S FOR MOST AREAS...AND EVEN 50 FOR SW.
BY SATURDAY NIGHT THE NEXT SHORT WAVE WILL BE PUSHING ACROSS THE
ROCKIES. INCREASING CLOUDS SHOULD HOLD TEMPS WELL ABOVE
NORMAL...WITH MID 20S TO AROUND 30 EXPECTED SUNDAY MORN. AS THE
WAVE MOVES ACROSS SUNDAY MODELS HAVE FAIRLY STRONG WINDS
ALOFT...WITH 850 MB WINDS NEAR 50 KTS. MODELS DO NOT MIX ALL THIS
DOWN...HOWEVER DO EXPECT A WINDY DAY AND WILL MONITOR FOR
POTENTIAL ADVISORY CONDITIONS. ANOTHER ISSUE WILL BE SOME WEAK
LIFT WITH THE WAVE. MOISTURE IS LIMITED INITIALLY AND WILL BE A
TOP DOWN SATURATION. ANOTHER ISSUE IS TEMPS WITH THIS WAVE. STILL
SEEING SOME WARM AIR AT THE SURFACE WITH GUIDANCE IN AGREEMENT
WITH HIGHS WARMING INTO THE 40S. LONG RANGE SOUNDINGS WOULD
SUGGEST SNOW EARLY IN THE DAY...WITH WARMING TEMPS AND A CHANGE
OVER TO RAIN.
FOR NEXT WEEK...RIDGE AMPLIFIES OUT WEST...ALTHOUGH SOME MODELS
DISAGREEMENT WITH THE STRENGTH. GFS IS WEAKER WITH THE RIDGE AND
ALLOWS ANOTHER CLIPPER TO BACK ACROSS THE HIGH PLAINS ON
TUESDAY...WHILE THE EC IS A LITTLE STRONG WITH THE RIDGE AND
KEEPS THE CLIPPER TO THE NORTHEAST. PENDING HOW FAR TO THE SW THE
CLIPPER DOES PUSHES...WILL PLAY A BIG PART TO THE FORECAST. THUS
FOR EARLY NEXT WEEK FORECAST HAS LOW CONFIDENCE. THOUGHT IS FOR
THE WARMER/DRIER AIR TO WIN...AS MOST OF THE WINTER THE BULK OF
THE WAVES HAVE GONE EAST OF THE AREA. THAT SAID...COOLER AIR AND
POSSIBLY SOME LIGHT PRECIP /FLURRIES OR SPRINKLES/ CAN NOT BE
RULED OUT FOR EARLY NEXT WEEK AND WILL NEED TO BE WATCHED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 527 AM CST WED JAN 8 2014
THE AREA OF MVFR/IFR CIGS AND VSBY IN LIGHT SNOW ACROSS NORTH
CENTRAL NEBRASKA IS EXPECTED TO TRANSITION TO MVFR CIGS BY 18Z.
GIVEN THE UPSLOPE WINDS DEVELOPING THIS MORNING...MOISTURE SHOULD
BECOME TRAPPED ACROSS THE FCST AREA THIS AFTERNOON THROUGH
TONIGHT. MEANWHILE...LOW LEVEL WINDS WILL INCREASE TONIGHT WHICH
SUGGESTS THERE IS A GOOD POTENTIAL FOR THE REDEVELOPMENT OF IFR
CIGS.
SOME IMPROVEMENT IS EXPECTED LATE TONIGHT AS THE LOW LEVEL JET
VEERS OFF WHICH COULD PRODUCE VFR AFTER 06Z FROM WEST TO EAST
ACROSS WESTERN NEBRASKA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
525 AM CST WED JAN 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST WED JAN 8 2014
MAIN FORECAST CONCERNS WILL BE SNOW CHANCES TODAY AND FREEZING
DRIZZLE CHANCES LATE TONIGHT...AS WELL AS TEMPERATURES.
RADAR AND OBSERVATIONS HAVE SOME LIGHT SNOW THAT HAS DEVELOPED
MAINLY NORTH OF INTERSTATE 80 EARLY THIS MORNING. SO FAR
OBSERVATIONS HAVE NOT HAD VERY LOW VISIBILITIES WITH THE SNOW.
A COUPLE OF UPPER LEVEL WAVES WILL BE MOVING THROUGH THE REGION
TODAY AND TONIGHT. THE SNOW THAT HAS DEVELOPED ACROSS THE NORTHERN
PORTION OF THE AREA IS EXPECTED TO SPREAD TO THE SOUTH EARLY THIS
MORNING. THE NAM AND GFS ARE SIMILAR IN DEVELOPING A BAND OF SNOW
ACROSS THE NORTH THEN MOVING IT TOWARD THE SOUTHEAST THIS MORNING
AND THE PRECIPITATION SHOULD BE EXITING THE AREA DURING THE
AFTERNOON. THE ONLY CONCERN IS THE HRRR AND 4KM WRF BOTH ARE MUCH
WEAKER WITH PRECIPITATION. THE HRRR DOES NOT GO OUT VERY FAR INTO
THE MORNING HOURS AT THIS TIME. WILL CONTINUE WITH THE SNOW WITH
THE BEST CHANCES FOR SNOW WILL BE DURING THE MORNING HOURS AND
MAINLY TO THE NORTH AND EAST OF THE TRI-CITIES. SNOWFALL AMOUNTS
SHOULD BE A HALF INCH TO AROUND AN INCH ACROSS NEBRASKA AND LESS
THAN A HALF INCH IN NORTH CENTRAL KANSAS. THE SNOW SHOULD COME TO
AN END FROM WEST TO EAST LATE THIS AFTERNOON.
THE MAIN CONCERN FOR TONIGHT WILL BE LATE TONIGHT. AFTER THE SNOW
MOVES OUT THE MID LEVELS DRY OUT SOME AND THE DENDRITIC LAYER IS
DRY..BUT LATE TONIGHT THERE IS A SHALLOW MOIST LAYER THAT IS COLD.
THIS COULD BRING A CHANCE FOR SOME LIGHT FREEZING DRIZZLE. THE
PREVIOUS FORECAST HAD JUST THE FAR SOUTHEAST. FORECAST SOUNDINGS
INDICATE THE BEST CHANCE WILL CONTINUE TO BE IN THE FAR SOUTHEAST. A
LITTLE FURTHER TO THE NORTHWEST THERE IS A SHALLOW LAYER OF MOISTURE
BUT IT IS FAIRLY SHORT LIVED BEFORE IT STARTS TO DRY OUT. WILL HAVE
TO WATCH TO SEE IF THAT MOIST LAYER CONTINUES OR WHETHER IT WILL DRY
OUT.
CURRENT TEMPERATURES ARE IN THE 20S ACROSS THE FORECAST
AREA...WHICH IS VERY NEAR TO THE FORECAST HIGHS FOR TOMORROW.
STILL EXPECT THE TEMPERATURES TO DROP OFF TOWARD MORNING SO WILL
LEAVE FORECAST HIGHS AS THEY ARE FOR NOW. LOWS TONIGHT WILL DIP
DOWN TO A FEW DEGREES EITHER SIDE OF 10 DEGREES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 AM CST WED JAN 8 2014
GUIDANCE SUGGESTS QUASI-ZONAL FLOW WILL BE NOTED ACROSS MUCH OF
THE CONUS TO START THE LONG TERM FORECAST PERIOD ON
THURSDAY...ALTHOUGH A MID LEVEL SHORTWAVE WILL ALSO BE MOVING INTO
THE NORTHWESTERN CONUS BY 12Z THURSDAY. GUIDANCE FROM THE
NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL SUGGEST THIS MID
LEVEL SHORTWAVE WILL MOVE SOUTHEAST INTO THE FOUR CORNERS REGION
BY 12Z FRIDAY...INTO CENTRAL TEXAS BY 00Z SATURDAY...AND NEAR THE
LOWER MISSISSIPPI VALLEY BY 12Z SATURDAY. AT THE SURFACE AN AREA
OF LOW BAROMETRIC PRESSURE IS EXPECTED TO BE REALIZED OVER THE
PANHANDLE OF TEXAS BY 12Z FRIDAY. THIS SURFACE LOW IS THEN
EXPECTED TO QUICKLY MOVE NORTHEAST AND NEAR THE GREAT LAKES REGION
BY 12Z SATURDAY.
MID LEVEL THERMAL ADVECTION AND INCREASING TROPOSPHERIC MOISTURE
SHOULD PROMOTE PRECIPITATION PRODUCTION ACROSS MUCH OF THE SOUTHERN
PLAINS THURSDAY NIGHT...WITH THE PRIMARY AXIS OF MID LEVEL OMEGA
THEN EXPECTED TO MOVE INTO POTIONS OF THE MID TO LOWER MISSISSIPPI
VALLEY DURING THE DAY FRIDAY...A SOLUTION SUPPORTED BY QPF FIELDS
FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN. ALL THAT BEING
SAID...MODEL GUIDANCE CONTINUES TO SUGGEST THE WEST/NORTHWESTERN
PERIPHERY OF THIS OMEGA AXIS WILL CLIP PORTIONS OF THE
CENTRAL PLAINS DURING THE DAY FRIDAY...WITH THE SOUTHEASTERN HALF
OUR CWA STILL EXPECTED TO OBSERVE MEASURABLE PRECIPITATION DURING
THE DAY FRIDAY. GIVEN THE MODEL AGREEMENT...AS WELL AS MODEL
CONSISTENCY THROUGH THE PAST 24 HOURS...OPTED TO KEEP POPS GOING
ACROSS ROUGHLY THE SOUTHEASTERN HALF OF THE CWA 12Z FRIDAY THROUGH
00Z SATURDAY...AND ACTUALLY INCREASED POPS ACROSS THE SOUTHEASTERN
ONE-THIRD OF THE CWA INTO THE 40-50% RANGE.
GUIDANCE ALSO SUGGESTS SURFACE TEMPERATURES ACROSS OUR CWA ON
FRIDAY WILL START IN THE LOWER 20S...BUT EVENTUALLY RISE RISE INTO
THE 30S TO NEAR 40 FRIDAY AFTERNOON. FORECAST PROXIMITY SOUNDINGS
FROM THE ACROSS OUR CWA...PER THE NAM AND OPERATIONAL GFS...CONTINUE
TO SUGGEST A SIGNIFICANT WARM LAYER WILL EXIST...PRIMARILY BETWEEN
750MB AND 900MB...THROUGH 15Z OR 18Z FRIDAY. AS A RESULT...FREEZING
RAIN CONTINUES TO LOOK LIKE A POSSIBILITY GENERALLY ALONG AND
SOUTHEAST OF LINE FROM PHILLIPSBURG...TO GRAND ISLAND AND
FULLERTON...WITH CHANCES FOR SUCH ACTIVITY INCREASING AS ONE MOVES
SOUTHEAST ACROSS THE CWA. THESE SAME FORECAST PROXIMITY SOUNDINGS
ALSO SUGGEST WE WILL LIKELY BE WAITING FOR THE MID TO LOWER
TROPOSPHERE TO SATURATE UNTIL AROUND 12Z FRIDAY...THUS IS WHY THE
AFOREMENTIONED POPS WERE NOT INTRODUCED UNTIL 12Z FRIDAY. IN
ADDITION...BASED ON GUIDANCE...IT APPEARS THE TEMPERATURE THROUGH
MOST LOCATIONS ACROSS THE CWA WILL RISE ABOVE FREEZING BY 18Z AND AS
A RESULT...FREEZING RAIN WORDING COMES TO AN END IN THE OFFICIAL
FORECAST BY 18Z FRIDAY...WITH RAIN THEN EXPECTED WITH ANY PRECIPITATION
THROUGH THE REST OF THE DAY.
TAKING AN AVERAGE OF THE NAM...OPERATIONAL GFS...EC...SREF-MEAN
AND WPC GUIDANCE PROVIDES LIQUID PRECIPITATION AMOUNTS OF A COUPLE
HUNDREDTHS OF AN INCH NEAR THE TRI-CITIES...TO AROUND 0.10"
FARTHER SOUTHEAST DURING THE 12-18Z FRIDAY TIMEFRAME. ADDITIONAL
LIQUID PRECIPITATION AMOUNTS OF 0.01-0.05" ARE THEN ANTICIPATED
ACROSS OUR EAST/SOUTHEAST FRIDAY AFTERNOON. GIVEN ALL THIS IT
CERTAINLY SEEMS AS THOUGH WE ARE HEADING TOWARDS AN ADVISORY-
WORTHY EVENT ON FRIDAY WITH A FEW HUNDREDTHS TO PERHAPS A TENTH OF
AN INCH OF ICING APPEARING POSSIBLE ACROSS THE SOUTHEASTERN HALF
OF THE CWA. AS MENTIONED YESTERDAY...WE ARE STILL ABOUT 24 HOURS
FROM THIS MID LEVEL SHORTWAVE ACTUALLY MAKING LANDFALL OVER THE
NORTHWESTERN CONUS...AT WHICH TIME SUFFICIENT SAMPLING BY THE
UPPER AIR NETWORK SHOULD ALLOW MODEL GUIDANCE TO REALLY NAIL DOWN
THE TRACK AND TIMING OF THIS SYSTEM. PROVIDED THE CONTINUED
UNCERTAINTY OF THIS SYSTEM...WILL CONTINUE TO KEEP THE HWO
SOMEWHAT VAGUE WITH RESPECT TO ICING AMOUNTS...BUT CERTAINLY
MAINTAIN THE MENTION OF FREEZING RAIN FRIDAY MORNING WITH THE
POTENTIAL FOR DIFFICULT DRIVING CONDITIONS.
AS ALREADY MENTIONED...IT APPEARS WE WILL BE WAITING FOR THE MID
TO LOWER TROPOSPHERE TO SATURATE THROUGH ABOUT 12Z FRIDAY. THAT
BEING SAID...PERSISTENT SOUTHERLY LOW LEVEL FLOW AND RESULTANT LOW
LEVEL MOISTURE FLUX INTO THE AREA SHOULD ALLOW FOR RISING DEW
POINT VALUES ACROSS MUCH OF OUR CWA THURSDAY NIGHT INTO FRIDAY
MORNING. GUIDANCE FROM THE NAM...OPERATIONAL GFS AND EC ALL
SUGGEST 0-0.5KM RH VALUES WILL CLIMB INTO THE 90-100% RANGE ACROSS
ROUGHLY THE SOUTHEASTERN ONE-THIRD OF OUR CWA BETWEEN 06Z AND 12Z
FRIDAY. THESE SAME SETS OF GUIDANCE ALSO SUGGEST LOW LEVEL
TURBULENT MIXING ON THE ORDER OF 15-20KTS WILL BE PRESENT DURING
THE SAME TIME PERIOD. GIVEN ALL THIS...WILL CONTINUE THE MENTION
OF FREEZING DRIZZLE...ROUGHLY ALONG AND SOUTHEAST OF A LINE FROM
PHILLIPSBURG TO HEBRON....IN THE HWO AND GRIDS 06-12Z FRIDAY.
BEYOND THE DAY FRIDAY...THE MAJORITY OF THE LONG TERM FORECAST
PERIOD REMAINS DRY...WITH THE ONLY EXCEPTION BEING SUNDAY INTO
SUNDAY NIGHT. BOTH THE OPERATIONAL GFS AND EC SUGGEST A MID LEVEL
SHORTWAVE WILL MOVE ACROSS THE REGION DURING THIS TIME PERIOD AND
ALLBLEND RESPONDED BY PROVIDING ~20% POPS TO MUCH OF THE CWA. THESE
POPS WERE LEFT UNCHANGED FOR THE MOST PART.
A WARM LOW LEVEL AIRMASS IS EXPECTED TO MAINTAIN ITSELF ACROSS
THE CENTRAL PLAINS THROUGHOUT THE LONG TERM FORECAST PERIOD...WITH
AFTERNOON HIGHS IN THE 30S TO NEAR 40 THURSDAY AND FRIDAY...AND IN
THE 40S TO NEAR 50 SATURDAY ONWARD. OVERNIGHT LOWS IN THE TEENS
AND 20S WILL ALSO LIKELY BE COMMON DURING THE LONG TERM FORECAST
PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 525 AM CST WED JAN 8 2014
SNOW CONTINUES TO MOVE THROUGH THE KGRI TERMINAL AREA EARLY THIS
MORNING. THE HEAVIEST SNOW THAT WILL REDUCE VISIBILITIES AND
CEILINGS THE MOST WILL BE FOR A FEW HOURS THIS MORNING. STILL
EXPECT MVFR CONDITIONS THROUGH THE REMAINDER OF THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...JCB