Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/09/16
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
855 PM MST FRI JAN 8 2016
.SYNOPSIS...
LOW PRESSURE SYSTEM THAT BROUGHT THE PRECIPITATION TO THE AREA
THURSDAY WILL CONTINUE TO MOVE EASTWARD TODAY. HOWEVER...CONDITIONS
WILL BE SUFFICIENT TO PRODUCE LIMITED LOWER DESERT RAIN SHOWERS AND
HIGHER TERRAIN SNOW SHOWERS THROUGH THIS EVENING. THE THREAT OF
PRECIPITATION WILL DIMINISH SATURDAY...THOUGH ANOTHER WEAK STORM
SYSTEM WILL BRING A VERY SLIGHT CHANCE OF SHOWERS TO THE AREA AGAIN
SATURDAY NIGHT AND SUNDAY. NEXT WEEK WILL GENERALLY BE RAIN- FREE
ACROSS THE DESERT SOUTHWEST. TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.DISCUSSION... MAIN UPPER LOW HAS SHIFTED OFF WELL TO THE EAST OF
ARIZONA...BUT A SOMEWHAT CYCLONIC NORTHWEST FLOW ALOFT BEHIND THE
LOW WAS PRESENT OVER ARIZONA WITH VERY WEAK DISTURBANCES EMBEDDED IN
THE FLOW MOVING ACROSS THE AREA. SIGNIFICANT LOW LEVEL MOISTURE
REMAINED OVER EASTERN AZ...MAINLY FROM PHOENIX EASTWARD...AND THE
LATEST 00Z RAOBS AT BOTH TUS AND FLG SHOWED NEARLY SATURATED
CONDITIONS BELOW ABOUT 700MB. CONSIDERABLE CU/SC PERSISTED OVER
SOUTH CENTRAL ARIZONA AND ALTHOUGH MOST OF THE SHOWERS HAVE ENDED
THERE STILL REMAIN A FEW WEAK ECHOES HERE AND THERE MAINLY NORTH AND
EAST OF CENTRAL PHOENIX. IR IMAGERY AT 8 PM SHOWED MOSTLY CLOUDY
SKIES FROM PHOENIX EAST WITH MOSTLY CLEAR SKIES OVER THE WESTERN
DESERTS. FOR THE REST OF THE EVENING THERE REMAINS A CHANCE OF A
LIGHT RAIN OR HIGHER ELEVATION SNOW SHOWER IN ZONE 24...AND A FEW
LIGHT SPRIKLES ARE POSSIBLE IN THE GREATER PHOENIX AREA. OTHERWISE
THERE SHOULD BE CONTINUED PARTIAL CLEARING ACROSS SOUTH CENTRAL AZ
AFTER MIDNIGHT WITH SOME HIGH CLOUDS SPREADING IN FROM THE WEST
AFTER MIDNIGHT. CURRENT FORECASTS LOOK TO BE IN GOOD SHAPE AND NO
UPDATES ARE NEEDED AT THIS TIME.
.PREVIOUS DISCUSSION...
CUMULUS AND STRATOCU FIELDS LINGER ACROSS CENTRAL PHOENIX AND POINTS
EASTWARD. SOME LIMITED CU FIELDS ARE RETURNING TO THE SOUTHWESTERN
DESERTS THAT EARLIER BROKE OUT IN SUNSHINE AND THOSE SHOULD DISSIPATE
A LITTLE WHILE AFTER SUNSET. AFTN WATER VAPOR AND IR LOOPS INDICATE
THE ML CUTOFF LOW REMAINS TO OUR NORTHEAST OVER THE FOUR
CORNERS...SLOWLY TRANSITIONING EASTWARD WITH ONE SHORTWAVE LOBE STILL
SWEEPING THROUGH CENTRAL AZ. LIGHT SHOWER ACTIVITY IS STILL
PERCOLATING OVER THE MOGOLLON RIM AND SOME OF THE MOUNTAINOUS AREAS
ON THE NORTH-EAST PERIPHERY OF THE PHX METRO. ENSEMBLE APPROACH OF
HI-RES PRECIP PLOTS INDICATE MOST ACTIVITY SHOULD WRAP THIS AFTERNOON
AND BE DONE OVER THE PHOENIX METRO. HOWEVER...LAST FEW RUNS OF BOTH
THE OPERATIONAL AND EXPERIMENTAL HRRR DO INDICATE A ROGUE SHOWER OR
TWO POPPING UP POST 00Z OVER THE PHX METRO BUT LIKELY PRESENT AS JUST
SOME SPRINKLES AND NOT MUCH ELSE. ALSO...WHILE THE WIDESPREAD SNOW
ACTIVITY HAS DIMINISHED ACROSS SOUTHERN GILA COUNTY THIS EVENING
SOME ROADWAY/TRAVEL RELATED IMPACTS MAY PERSIST OR WORSEN (ICY AND
SLUSHY ROADS) SO WILL LEAVE THE WINTER WEATHER ADVISORY IN PLACE
THROUGH THIS EVENING TO ACCOUNT FOR ANY LINGERING HAZARDS.
CLEAR SKIES AND SUBSIDENT FLOW ACROSS THE WESTERN CWA HAS ALLOWED
FOR ENOUGH DRYING TO KEEP ANY CONCERN FOR FOG OUT OF THEIR FORECAST
FOR TOMORROW AM. ACROSS THE SOUTH-CENTRAL DESERTS SOME DRYING OF THE
BOUNDARY LAYER AND FURTHER REMOVAL FROM THE SOAKING RAINS BY A DAY
PLUS SHOULD WARD OFF SIGNIFICANT FOG DEVELOPMENT ACROSS THE WHOLE OF
THE SOUTH-CENTRAL AZ DESERTS...INCLUDING THE PHX METRO. SOME OF THE
LOWER LYING DRAINAGE AREAS AND MORE OPEN AG/UNDEVELOPED AREAS WITH
PONDED WATER COULD SEE SOME PATCHY FOG IN THE EARLY AM HOURS BEFORE
HIGH CLOUDS BEGIN TO MOVE IN FROM THE NORTHWEST.
PATTERN SHIFT WILL TAKE PLACE THIS WEEKEND AS A LONG-WAVE RIDGE
BECOMES ESTABLISHED ALONG THE WEST COAST...RESULTING IN A PERSISTENT
NORTHWESTERLY FLOW. OPERATIONAL GFS/ECMWF STILL SHOW SEVERAL WEAKER
SHORT-WAVE TROUGHS MAKING THEIR WAY INTO THE INTERMOUNTAIN WEST OVER
THE NEXT WEEK...BUT WITH LESSER IMPACTS ACROSS THE DESERT SOUTHWEST.
THE NEXT IN THE SERIES OF TROUGHS WILL DROP INTO THE FORECAST AREA
SATURDAY NIGHT AND SUNDAY...BUT WITH WEAK MOISTURE
TRANSPORT...PRECIPITATION CHANCES WILL BE LESS THAN 20 PERCENT.
MODELS INDICATE ANOTHER WEAK TROUGH WILL BRING A CHANCE RAIN LATE IN
THE WEEK...THOUGH THERE IS MORE UNCERTAINTY WITH THIS SYSTEM.
TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... L
CONSIDERABLE LOW/MID CLOUD PERSISTING ACROSS THE GREATER PHOENIX
AREA THIS EVENING...WITH CIGS DOWN AS LOW AS 4-5K FEET IN PLACES AND
WIDESPREAD CIGS 8-10K FEET. EXPECT THAT CIGS WILL START TO SCATTER
OUT LATER THIS EVENING AS SOMEWHAT DRIER AIR STARTS TO WORK IN FROM
THE NORTHWEST. STILL...LATEST HI-RES GUIDANCE SUGGESTS SHOWERS IN
THE AREA THRU 06Z...AND FORECAST SOUNDINGS KEEP RATHER SATURATED
LAYERS AROUND 5K FEET INTO THE MORNING ON SATURDAY. WILL ATTEMPT TO
SCATTER OUT THE LOWEST DECKS AFTER 06Z IN THE PHOENIX TAFS BUT
REALIZE THAT A STRAY CIG BELOW 6K FEET IS POSSIBLE PAST 12Z SAT.
SOME HIGH CLOUDS SHOULD BE MOVING INTO THE AREA FROM THE WEST LATER
TONIGHT AND INTO THE DAY SATURDAY AS WELL.
AS FAR AS THE POTENTIAL FOR FOG ON SAT MORNING IS CONCERNED...IT
APPEARS THAT FOG DEVELOPMENT IS UNLIKELY DUE TO THE FACT IT APPEARS
THAT ENOUGH DRY AIR WILL BE MIXING DOWN TO THE SFC TO PREVENT FOG
FORMATION...ALONG WITH THE FACT THAT INCREASING HIGH CLOUDINESS
SHOULD INHIBIT NIGHTTIME COOLING OF THE LOWER LEVELS OF THE
ATMOSPHERE. WINDS WILL BE REMAINING ON THE LIGHT SIDE...MAINLY 8 KTS
OR LESS...AND FAVOR USUAL DIURNAL TRENDS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SKIES TO REMAIN MOSTLY CLEAR ASIDE FROM SOME SCT-BKN CIRRUS LAYERS
PASSING OVER THE TERMINALS FROM TIME-TO-TIME THROUGH THE TAF PERIOD.
WINDS TO REMAIN ON THE LIGHT SIDE...8 KTS OR LESS...FAVORING A
NORTHERLY DIRECTION AT KBLH AND WESTERLY AT KIPL.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A FAST MOVING WEATHER SYSTEM WILL BRING A CHANCE OF SHOWERS MAINLY
SATURDAY NIGHT INTO SUNDAY AS A WEAK DISTURBANCE PASSES THROUGH THE
REGION. COOL TEMPERATURES WILL PREVAIL WITH SOME GRADUAL WARMING
GOING INTO NEXT WEEK...BUT HIGHS WILL REMAIN BELOW NORMAL. HIGH
PRESSURE WILL SETTLE IN EARLY NEXT WEEK ALLOWING FOR GRADUAL DRYING
CONDITIONS. HUMIDITY WILL BE MUCH ABOVE AVERAGE WITH MINIMUM VALUES
NEAR 50 PERCENT INTO MONDAY WITH VALUES FALLING INTO THE 30S BY
WEDNESDAY. WINDS SHOULD BE LIGHT THROUGH THE ENTIRE PERIOD.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...CB
PREVIOUS DISCUSSION...NOLTE/HIRSCH
AVIATION...PERCHA/CB
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS TUCSON AZ
305 PM MST THU JAN 7 2016
.SYNOPSIS...WIDESPREAD RAIN AND SNOW...HEAVY SNOW IN THE
MOUNTAINS...WILL CONINTUE TONIGHT INTO FRIDAY. SHOWERS WILL DECREASE
FROM WEST TO EAST BY LATE FRIDAY NIGHT. A WEAKER SYSTEM WILL THEN
BRING A SLIGHT CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS
SUNDAY. OTHERWISE...DRY CONDITIONS WITH BELOW AVERAGE DAYTIME
TEMPERATURES WILL PREVAIL SATURDAY INTO THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...THE MAIN PRECIPITATION BAND WAS PASSING THROUGH
SOUTHEAST ARIZONA THIS AFTERNOON. RECENT REPORTS OF SNOW FALLING
AROUND THE TOWN OF CATALINA AND ORACLE SUGGESTED THAT THE SNOW LEVEL
WAS AS LOW AS 3500 FEET IN SPOTS WITH THE HEAVIER SHOWERS. ALTHOUGH
GROUND TEMPERATURES ARE TOO WARM FOR ANY SIGNIFICANT ACCUMULATIONS
AT THIS TIME. THAT SAID...CONCERNED ABOUT THE EASTERN CWA AS THE
PRECIPITATION BAND TRACKS FARTHER EAST THIS EVENING. WILL GO AHEAD
AND POST A WINTER WEATHER ADVISORY FOR VALLEY LOCATIONS WHICH 1 TO 2
INCHES MIGHT ACCUMULATE AFTER DARK THIS EVENING AND TONIGHT. WILL
ALSO INCLUDE THE MOUNTAINS WITH THE WEST FACING SLOPES PICKING UP
SEVERAL INCHES LATER THIS EVENING AND TONIGHT. OTHERWISE...WILL
CONTINUE THE WINTER STORM WARNING FOR THE WHITE MOUNTAINS AND THE
WINTER WEATHER ADVISORY FOR THE MOUNTAINS JUST EAST AND NORTHEAST OF
TUCSON. PLEASE REFER THE LATEST WWA PRODUCT UNDER THE AWIPS HEADER
PHXWSWTWC OR WMO HEADER WWUS45. LATEST HRRR SOLUTIONS SHOWED THE
BULK OF PRECIPITATION SHIFTING INTO OUR EASTERN CWA BY 06Z WITH
CLEARING MAINLY WEST OF TUCSON. THEREAFTER...LOOKING AT MORE OR LESS
SCATTERED SHOWERS ON FRIDAY AS AN IMPULSE DROPS SOUTH ON THE
BACKSIDE OF THE MAIN SYSTEM WHICH WAS PROGGED TO MOVE INTO THE TEXAS
PANHANDLE FRIDAY AFTERNOON. ALONG WITH THE WET WEATHER...STRONG AND
GUSTY WINDS CAN BE ANTICIPATED THIS EVENING AS THE SYSTEMS PASSES
THROUGH THE AREA. IMPROVING WEATHER FRIDAY NIGHT AND SATURDAY BEFORE
YET ANOTHER A WEAKER SYSTEM IMPACTS THE STATE AROUND SATURDAY NIGHT
AND SUNDAY.
&&
.AVIATION...VALID THRU 09/00Z.
BKN-OVC CLOUDS 7-10K FT MSL WITH VALLEY RAIN AND MOUNTAIN SNOW.
MOUNTAINS MOSTLY OBSCURED ABOVE 5000 FEET MSL DUE TO CLOUDS AND
PCPN. BRIEF LOCAL IFR CONDITIONS WILL EXIST WITH THIS PRECIPITATION.
CONDITIONS IMPROVING FROM WEST TO EAST AFT 08/06Z. SURFACE WIND
BECOMING SWLY 12-20 KTS WITH GUSTS TO 35 KTS POSSIBLE ESPECIALLY IN
COCHISE COUNTY. WIND EASING AFTER 08/02Z BECOMING SW-W 10 KTS OR
LESS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT PERIODS OF VALLEY RAIN AND MOUNTAIN SNOW INTO
THE EVENING FOR THE MAJORITY OF SOUTHEAST ARIZONA...WITH ANOTHER
PERIOD OF SHOWERS FRIDAY MAINLY ZONES 152 AND 153. DRY CONDITIONS
RETURN ACROSS MUCH OF THE AREA SATURDAY WITH ANOTHER CHANCE OF
SHOWERS SUNDAY. DRY CONDITIONS WITH A VERY MODEST WARMING TREND WILL
THEN PREVAIL MONDAY INTO TUESDAY. BREEZY TO WINDY SOUTHWEST WINDS
WILL OCCUR TODAY...OTHERWISE 20-FOOT WINDS WILL GENERALLY BE TERRAIN
DRIVEN AND MAINLY LESS THAN 15 MPH.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING TIL 11 AM MST FRIDAY FOR AZZ510.
WINTER WEATHER ADVISORY TIL 5 AM MST FRIDAY FOR
AZZ506-509-5011>5014.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
P
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
930 PM PST WED JAN 6 2016
.SYNOPSIS...
SHOWERS...LOCALLY HEAVY...WILL CONTINUE TONIGHT AND THURSDAY
MORNING...THEN BECOME GRADUALLY LESS NUMEROUS AND LESS INTENSE
THURSDAY AFTERNOON THROUGH FRIDAY. LOCAL FLASH FLOODING WILL BE
POSSIBLE THROUGH THURSDAY MORNING. HEAVY SNOW WILL OCCUR IN THE
MOUNTAINS AT TIMES THROUGH THURSDAY...MAINLY ABOVE 4500 FEET...THEN
GRADUALLY DECREASE THURSDAY NIGHT AND FRIDAY. VERY LARGE SURF WILL
OCCUR AT THE BEACHES THURSDAY...THEN START TO DECREASE FRIDAY. MORE
SHOWERS COULD OCCUR SATURDAY OR SATURDAY NIGHT...WITH FAIR WARMER
WEATHER LIKELY RETURNING FOR A COUPLE DAYS EARLY NEXT WEEK. ANOTHER
SYSTEM COULD BRING MORE PRECIPITATION AROUND THE MIDDLE OF NEXT
WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
SCATTERED SHOWERS CONTINUED IN MOST AREAS AT MID EVENING...WITH
LOCALLY BUT FAIRLY BRIEF HEAVY RAIN IN PARTS OF ORANGE COUNTY THE
PAST HOUR. THE TROUGH CURRENTLY OVER CALIFORNIA IS FAIRLY BROAD WITH
TRAINING VORT MAXES ON THE SOUTH SIDE...MOVING THROUGH SO-CAL
THROUGH EARLY THURSDAY AFTERNOON...FOR CONTINUOUS SHOWER ACTIVITY
WITH PERIODS OF MODERATE TO HEAVY RAIN...BUT ALSO PERIODS WITH
LIMITED PRECIPITATION. THE VORT MAX TRAIN WILL MOVE SOUTH INTO
NORTHERN BAJA THURSDAY AFTERNOON...SO THIS WILL HELP TO DECREASE THE
PRECIPITATION OVER SO-CAL GRADUALLY. AFTER THURSDAY...MOST OF THE
PRECIP WILL BE OVER SAN DIEGO COUNTY WITH JUST ISOLATED SHOWERS
FURTHER NORTH. WHILE WE SHOULD NOT REPEAT THE SIGNIFICANT FLOODING
EVENTS OF TUESDAY AND TODAY...WE STILL HAVE SOME THREAT OF LOCALIZED
FLASH FLOODING THROUGH THURSDAY MORNING...ESPECIALLY WHERE THE SOILS
ARE SATURATED AS ABOUT HALF OUR FORECAST AREAS HAS HAD RAINFALL
BETWEEN 2.5 AND 5 INCHES. SNOW LEVELS WILL FALL TO 4500 FEET
OVERNIGHT...SO ABOVE THAT LEVEL THE FLOOD THREAT WILL CHANGE (IF IT
HAS NOT ALREADY) TO THE SNOW THREAT...AND SOME AREAS HAVE ALREADY
HAD 2 FEET OF SNOW. 1 ADDITIONAL FOOT OF SNOW COULD FALL IN SOME
AREAS...ESPECIALLY OVER RIDGES AND UPPER WEST SLOPES...AND THE FOCUS
WILL GRADUALLY BECOME MORE ON THE SAN DIEGO COUNTY MOUNTAINS
THURSDAY VERSUS FURTHER NORTH.
SOME RIDGING COULD MOVE IN THIS WEEKEND THROUGH EARLY NEXT
WEEK...BUT THE EAST PACIFIC WILL CONTINUE TO HAVE MOIST FLOW...PLUS
THE NOW MOIST BOUNDARY LAYER OVER LAND...SO ANY IMPULSE THAT MOVES
THROUGH...SUCH AS ONE FOR LATE SATURDAY/SATURDAY NIGHT...COULD
EASILY PRODUCE PRECIP. WE MIGHT BE ABLE TO GET 2-3 DAYS OF DRY
WEATHER EARLY NEXT WEEK BEFORE ANOTHER SYSTEM MOVES THROUGH AROUND
MIDWEEK.
&&
.AVIATION...
070500Z...VARIOUS CIGS OF 1500-5000 FT MSL AND VIS 2-4 SM IN AREAS
OF HEAVIER RAINFALL WILL CONTINUE AT TIMES THROUGH THU AS SHOWERS
MOVE ACROSS THE REGION. ISOLATED TSRA ARE POSSIBLE THROUGH THE
PERIOD. GUSTY WESTERLY WINDS WILL DEVELOP LATE TONIGHT AND CONTINUE
THROUGH THU...MAINLY OVER THE MTNS AND ALONG DESERT MOUNTAIN SLOPES.
&&
.MARINE...
900 PM...WESTERLY WINDS GUSTS NEAR 25 KTS WILL CONTINUE
OVER THE COASTAL WATERS THROUGH FRIDAY. HEAVY TO MODERATE RAIN AND
PERIODS OF THUNDERSTORMS WILL ALSO OCCUR THROUGH THE PERIOD. SEAS
WILL CONTINUE TO SLOWLY INCREASE INTO THE DAY ON THURSDAY. SEAS WILL
BE 9 TO 12 FT THROUGH FRIDAY...WITH 11 TO 16 FT SEAS EXPECTED
THURSDAY. SEE THE SMALL CRAFT ADVISORY FOR ADDITIONAL
DETAILS...LAXMWWSGX. WINDS AND SEAS WILL DECREASE BY SATURDAY...BUT
PERIODS OF SHOWER ACTIVITY WILL REMAIN POSSIBLE INTO NEXT WEEK.
&&
.BEACHES...
900 PM...AN ELEVATED WEST SOUTHWEST SWELL WILL CONTINUE
TO BUILD THE SURF INTO THURSDAY. SURF OF 7-12 FT WITH SETS NEAR 15
FT ALONG FAVORED WEST FACING BEACHES IS POSSIBLE BY THURSDAY..WITH
HIGHEST SETS EXPECTED IN SAN DIEGO COUNTY. COASTAL FLOODING AND
POTENTIAL DAMAGE TO COASTAL STRUCTURES...SUCH AS PIERS...WILL BE
POSSIBLE ON THURSDAY. FOR ADDITIONAL DETAILS...SEE THE LAXCFWSGX.
THE SURF WILL REMAIN HIGH ON FRIDAY...WITH LOWER SURF EXPECTED OVER
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.HYDROLOGY... THE SAN DIEGO RIVER AT FASHION VALLEY IS CURRENTLY AT
10.6 FEET (9:15 PM) BUT APPEARS TO BE CRESTING NOW. WE COULD STILL
GO ABOVE FLOOD STAGE FOR AWHILE TONIGHT.
ADDITIONAL RAINFALL WILL BE MORE VARIABLE DUE TO THE SHOWERY
ACTIVITY...BUT VALUES WILL MOSTLY BE 0.75 TO 1.5 INCHES...WITH SOME
LOCATIONS IN THE MOUNTAINS RECEIVING 2 OR MORE ADDITIONAL INCHES
THROUGH THURSDAY. A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 11
AM THURSDAY FOR AREAS OVER AND WEST OF THE MOUNTAINS BELOW 4500 FOOT
ELEVATION.
PRECIP AMOUNTS WILL BE SUBSTANTIALLY LESS AFTER THURSDAY...MOSTLY
UNDER 0.5 INCHES THU NIGHT/FRI. AMOUNTS FOR SAT/SAT NIGHT DO NOT
LOOK EXCESSIVE RIGHT NOW...LIKELY UNDER 0.5 INCHES IN MOST AREAS.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT CURRENTLY REQUESTED BUT COULD BE REQUESTED
AGAIN THURSDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR ORANGE COUNTY
COASTAL AREAS-ORANGE COUNTY INLAND AREAS-RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO
AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO
COUNTY COASTAL AREAS-SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO
COUNTY VALLEYS-SAN GORGONIO PASS NEAR BANNING-SANTA ANA
MOUNTAINS AND FOOTHILLS.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY FOR SAN DIEGO COUNTY
MOUNTAINS.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY FOR RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS.
BEACH HAZARDS STATEMENT THROUGH THURSDAY MORNING FOR ORANGE
COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
HIGH SURF WARNING UNTIL 10 PM PST FRIDAY FOR ORANGE COUNTY
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
PZ...SMALL CRAFT ADVISORY UNTIL 4 PM PST FRIDAY FOR COASTAL WATERS
FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT TO 30 NM-
WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING
30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND.
&&
$$
PUBLIC/HYDROLOGY...MAXWELL/HARRISON
AVIATION/MARINE/BEACHES...JTT
Area Forecast Discussion
National Weather Service Sacramento CA
938 PM PST WED JAN 6 2016
.SYNOPSIS...
ACTIVE WEATHER PATTERN CONTINUES TO IMPACT NORTHERN CALIFORNIA
THIS WEEK AND INTO THE WEEKEND. MOUNTAIN SNOW AND VALLEY RAIN
THROUGH THIS EVENING WITH LINGERING SHOWERS ON THURSDAY. STILL
LOOKS LIKE FRIDAY WILL BE A RELATIVELY DRY DAY MOST AREAS WITH
ANOTHER ROUND OF RAIN AND MOUNTAIN SNOW EXPECTED FRIDAY NIGHT
INTO SATURDAY.
&&
.DISCUSSION...
A band of rain extending through the delta and Sacramento area
extends to the northeast up into Plumas County. Elsewhere
scattered showers are persisting. The HRRR model indicates the
band to persist for the next 2 to 3 hours before gradually
dissipating. The HRRR indicates the band should not be bringing
the current higher rainfall rates to the higher elevations of the
western slopes. Snowfall has tapered but is expected to continue
at times for a good portions of the night. Only expecting 1 to 2
inches of additional snowfall so will let the Winter Storm Warning
expire but put up a Winter Weather Advisory until 4 am.
A circulation will remain off of Oregon as the low splits with the
bulk of the low pressure area moving southeast of the area.
Chances of showers will persist on Thursday with the better
chances over the mountains. As the weaker low moves over the far
northern areas Thursday night showers may persist. The low
continues to drop southeast and into the Great Basin on Friday and
the interior should be drying out during the daytime.
The models are indicating a system Friday night and Saturday that
looks like it should bring us a decent round of rainfall and snow
for the mountains. Both today and tonight`s model runs are
indicating the storm is stronger than yesterday. Snow levels will
again be on the lower side and similar to this current storm.
Winds will become breezy as the front move through but at this
time do not look as strong. The rain will change over to showers
from west to east during the day and gradually diminish Saturday
night.
&&
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)
Model consensus in the EFP is the only relatively dry day in Norcal
will be Sun...possibly Tue. A highly amplified ridge continues along
the W Coast early next week...which periodically gets displaced or
flattened by migratory/progressive trofs.
Dry Nly flow is forecast over Norcal on Sun as Sat`s system moves
into the Desert SW. Ridging builds over Norcal during the day which
brings a break in the wet pattern.
The GFS is faster than the ECMWF in breaking down the W Coast ridge
on Mon and then re-establishing the ridge again on Tue. Meanwhile...
the slower ECMWF lingers the trof over Norcal on Tue. The model
differences lead to low confidence and inclusion of at least a low
PoP into Tue for Norcal in what would be a light to modest precip
at best.
Similarly for Wed...the GFS is more progressive in what looks to be
a slightly wetter (but still modest) trof than Mon`s. Obviously...
the EFP details will need to be sorted out in later forecasts.
JHM
&&
.AVIATION...
S-SWly flow alf bcms NWly Thu as upr low movs into Grt Basin and
ofshr upr rdg apchs. In Intr NorCal, wdsprd MVFR with areas IFR
and lcl LIFR ovngt. Conds impvg in Cntrl Vly aft 19z Thu but
contd areas trrn obscd omtns in shwrs. Sn lvls arnd 030 ft. Sfc
wnds dcrsg this eve.
&&
.STO Watches/Warnings/Advisories...
Winter Weather Advisory until 4 AM PST Thursday for Western
Plumas County/Lassen Park.
Winter Weather Advisory until 4 AM PST Thursday for West Slope
Northern Sierra Nevada.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1105 AM MST THU JAN 7 2016
.UPDATE...
ISSUED AT 1104 AM MST THU JAN 7 2016
SNOW BAND AFFECTING THE EASTERN PORTIONS OF THE DENVER METRO AREA
DOWN INTO THE PALMER DIVIDE HAS BEEN QUITE PERSISTENT THIS
MORNING. AT THIS POINT...NOT SURE WE WILL SEE MUCH EROSION OR
MOVEMENT THROUGH THE AFTERNOON AS ITS BEING DRIVEN BY MID LEVEL
CONVERGENCE UNDERNEATH THE UPPER LEVEL COL. THERE MAY ALSO BE
CONVECTIVE REDEVELOPMENT IN THE FOOTHILLS GIVEN SOME BREAKS IN
THE CLOUDS AND A VERY UNSTABLE AIRMASS PER 12Z DENVER SOUNDING.
THOSE SHOWERS MAY BE VERY SLOW MOVING AND PRODUCE SPOTTY HEAVIER
SNOWFALL. SOME INDICATIONS BY HRRR THAT THESE SPREAD SOUTHEAST
INTO THE I-25 CORRIDOR VERY LATE THIS AFTERNOON/EARLY EVENING.
OVERALL...CONFIDENCE THROUGH THE REST OF THE DAY IS LOW BUT
CONFIDENCE IMPROVES THIS EVENING THROUGH FRIDAY MORNING WHEN MORE
WIDESPREAD SNOWFALL IS EXPECTED BEHIND WEAK FRONTAL PUSH AND
UPSLOPE FORCED SNOWFALL. WINTER WEATHER ADVISORIES LOOK PRETTY
GOOD RIGHT NOW WITH TRAVEL IMPACTS EXPECTED BY THIS EVENING AS
SNOW INCREASES AND TEMPERATURES DROP WITH NIGHTFALL.
UPDATE ISSUED AT 739 AM MST THU JAN 7 2016
CURRENT RADAR IMAGERY SHOWS LIGHT SNOW IS TRYING TO FILL IN ALONG
THE FRONT RANGE. IN FACT...SOME LIGHT SNOW HAS ALREADY DEVELOPED
IN PORTIONS OF THE METRO AREA PER LATEST OBSERVATIONS FROM
CENTENNIAL AIRPORT. HRRR SEEMS TO HAVE BEST HANDLE ON THIS FOR
NOW...WEAKENING IT DURING THE DIURNAL MINIMA LATER THIS MORNING
INTO EARLY AFTERNOON...AND THEN INCREASING AGAIN THIS EVENING.
CURRENT FORECAST LOOKS ON TRACK...ONLY MINOR POP CHANGES THIS
MORNING TO REFINE AREAS OF LIGHT SNOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM MST THU JAN 7 2016
RADAR AND WEB CAMERAS INDICATE WIDESPREAD LIGHT SNOW HAS MOVED
OVER WESTERN AND CENTRAL COLORADO. LOOKING AT WATER VAPOR
SATELLITE IMAGERY...IT APPEARS DIFFLUENT FLOW ALOFT IS HELPING TO
PRODUCE THIS SNOW. EXPECT THE SNOW TO SLOWLY SHIFT EAST OVER THE
FRONT RANGE MOUNTAINS THIS MORNING. STILL UNCERTAIN IF SNOW WILL
MAKE ONTO THE URBAN CORRIDOR TODAY. IF IT DOES MAKE IT...SNOWFALL
WILL BE LIGHT AND THE SNOW WILL LIKELY MELT ON THE ROADWAYS DUE TO
TEMPERATURES NEAR THE FREEZING POINT. LOWERED POPS FOR TODAY
ACROSS THE DENVER AREA AND EASTERN PLAIN WHERE SNOW LOOKS LESS
CERTAIN. THE BEST CHANCE FOR SNOW LOOKS TO BE LATE THIS AFTERNOON
WITH THE NEXT WAVE MOVING INTO THE DESERT SOUTHWEST. THIS MAY BE
IN TIME FOR THE EVENING COMMUTE.
BETTER CHANCE FOR SNOW WILL BE TONIGHT WHEN THE SECOND WAVE
CURRENTLY MOVING ONTO THE SOUTHERN CALIFORNIA COAST MOVES OVER THE
FOUR CORNERS. THE ECMWF AND GEM CONTINUE TO LEAD THE WAY AND SHOW
AROUND A QUARTER INCH TO A THIRD INCH OF QPF FOR TONIGHT. THE 00Z
GFS IS STARTING TO CATCH UP TO THEM. EVEN THOUGH CONFIDENCE IS HIGH
THAT WE SEE SNOW...CONFIDENCE IN SNOWFALL AMOUNTS REMAINS LOW. A
SURFACE HIGH BUILDING OVER THE NORTHERN ROCKIES AND A SURFACE LOW
OVER NORTHEAST NEW MEXICO/NORTHWEST TEXAS WILL HELP PRODUCE UPSLOPE
FLOW LATE TONIGHT AND INTO FRIDAY. AIRMASS WILL BE MOIST TONIGHT
AND LAPSE RATES WILL BE 6 TO 8 C/KM. SO ANY LIFT WILL LIKELY
PRODUCE LIGHT SNOW.
WILL ISSUE AN ADVISORY FOR THE MOUNTAINS...FOOTHILLS AND DENVER AREA.
EXPECT 5-10 INCHES FOR THE MOUNTAINS WITH 4-8 SOUTHERN FOOTHILLS AND
3-7 FOR THE NORTHERN FOOTHILLS AND DENVER METRO AREA. MAIN IMPACT
FROM THIS SYSTEM WILL BE SNOWPACKED AND ICY ROADS TONIGHT AND FRIDAY
MORNING EVEN IF SNOWFALL AMOUNTS FALL SHORT OF ADVISORY CRITERIA.
SNOW IS EXPECTED TO BEGIN LATE THIS AFTERNOON OR EARLY EVENING AND
MAY CATCH THE EVENING COMMUTE. THE FRIDAY MORNING COMMUTE WILL
LIKELY BE SLOW AND SLIPPERY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 344 AM MST THU JAN 7 2016
THE FORECAST CONUNDRUM OF THE PAST COUPLE OF DAYS HAS IMPROVED SOME
THIS SHIFT WITH BETTER CONTINUITY IN THE 00Z AND 06Z MODEL RUNS.
MODELS HAVE CONVERGED UPON THE UPPER LEVEL CLOSED LOW OVER THE 4-
CORNERS THURSDAY EVENING TRACKING EAST-SOUTHEASTWARD ACRS NRN NEW
MEXICO DURING THE DAY FRIDAY. THERE`S ALSO BETTER AGREEMENT AS TO
WHEN A RATHER STG COLD FRONT WILL DROP SOUTH INTO NERN COLORADO AND
ARRIVE IN THE DENVER METRO AREA. THE LEADING EDGE OF THIS COLDER
AIRMASS APPEARS TO REACH THE DENVER AREA LATE THURSDAY NIGHT...BUT
THE MAIN PUSH OF COLD AIR ARRIVES WITH SFC-600 MB NELY WINDS OF 10-
20KTS DURING THE 12Z-18Z TIME INTERVAL ON FRIDAY AS THE UPPER LOW
PASSES TO OUR SOUTH. THIS IS ALSO THE PERIOD OF GREATEST QG ASCENT
OVER THE AREA...THOUGH NOTHING EXTRAORDINARY BY ANY MEANS. FORCING
ALOFT COMBINED WITH WEAK LEE SLOPE OROGRAPHICS/UPSLOPE FLOW AND A
MOIST LAPSE RATE TO AROUND 600 MBS SHOULD BE SUFFICIENT TO GENERATE
ANOTHER 1.5-4 INCHES OF SNOW ACROSS SRN PORTIONS OF THE I-25 URBAN
CORRIDOR INCLUDING THE DENVER METRO AREA AND ADJACENT FOOTHILLS...
WITH LESSER AMOUNTS IN AREAS TO THE NORTH AND EAST. RIDGE TOPS AND
EAST SLOPES IN MTN ZONES 33-34 COULD ALSO PICK UP ANOTHER 2-5 INCHES
DURING THE DAY FRIDAY. THE WINTER WEATHER ADVISORY FOR SNOW IS
SET TO EXPIRE AT 21Z/FRIDAY.
AFTER 21Z/FRIDAY...MODELS SHOW THE NELY UPSLOPE FLOW ON THE
PLAINS WEAKENING WITH THE CORE OF COLDEST AIR AND MAX SFC PRESSURE
PASSING TO OUR SOUTHEAST. DEPTH OF THE MOISTURE EAST OF THE FRONT
RANGE ALSO GRADUALLY LOWERS AS DRIER AIR BEGINS TO ENTRAIN
DOWNWARD FROM MID-LEVELS IN NWLY FLOW. AS A RESULT SHOULD SEE A
STEADY DECLINE IN SNOWFALL INITIALLY ALONG THE FRONT RANGE AND
EVENTUALLY OUT ACROSS THE PLAINS BY AROUND MIDNIGHT. IF IT WERE
NOT FOR THE LINGERING CLOUD COVER OVERNIGHT TEMPERATURES WOULD
CERTAINTY PLUNGE BELOW ZERO IN MANY AREAS WITH THE FRESH SNOW
COVER AND LIGHT WINDS. HIGH TEMPERATURES ON FRIDAY AT LEAST 10
DEG F LOWER THAN THOSE TODAY DUE TO HEAVY CLOUD COVER...SNOWFALL
AND ONGOING COLD AIR ADVECTION.
LOOKING AHEAD TO THE WEEKEND...TEMPERATURES WILL STRUGGLE TO WARM
WITH LINGERING CLOUD COVER AND WEAK COLD AIR ADVECTION WITH
NORTHWEST FLOW SFC AND ALOFT. A WEAK WEATHER DISTURBANCE/SHORTWAVE
TROUGH MOVING ALONG MODERATE NWLY FLOW ALOFT IS FORECAST BY A
MAJORITY OF THE MODELS TO CLIP NERN COLORADO DURING THE SATURDAY
AFTERNOON/EVENING TIME FRAME. COULD SEE AN UPTICK IN HIGH COUNTRY
SNOWFALL WITH ITS PASSAGE AS WELL AS A SLIGHT CHANCE OF LIGHT SNOW
ON THE PLAINS...MAINLY ACROSS THE NORTHEAST CORNER OF THE CWA.
ADDITIONAL SNOW AMOUNTS GENERALLY LESS THAN 2 INCHES FOR THE HIGH
COUNTRY AND PRETTY MUCH NOTHING ON THE PLAINS. TEMPERATURE GUIDANCE
NOW IN BETTER AGREEMENT WITH HIGHS IN THE 20S ON THE PLAINS BOTH
DAYS AND TEENS/LOW 20S IN THE MTNS/HIGH VALLEYS. HIGH MTN VALLEY
LOWS WILL TURN QUITE COLD AGAIN BUT NO WHERE AS BITTER COLD AS THEY
WERE SEVERAL DAYS AGO.
NEXT WEEK LOOKS DRY AND WARMER WITH A HIGH RIDGE BUILDING IN FROM
THE WEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 1104 AM MST THU JAN 7 2016
BAND OF PERSISTENT SNOW STILL AFFECTING KDEN TO KAPA CORRIDOR.
MOST OF THIS SNOW SHOULD REMAIN LIGHT...WITH PERHAPS A HALF TO ONE
INCH OF ADDITIONAL ACCUMULATION. EXCEPTION WOULD BE NEAR KAPA
WHERE A SMALL AREA OF HEAVY SNOW COULD DROP ANOTHER 1-2 INCHES
THIS AFTERNOON. SNOW MAY SPREAD BACK OR REDEVELOP TO KBJC AND KFNL
BY 21Z-00Z...AND THEN BECOME WIDESPREAD ALL AREAS 00Z-04Z.
VISIBILITIES WILL RANGE FROM 1 TO 2 MILES FOR MOST OF THE LONG
DURATION SNOW EVENT INTO EARLY FRIDAY AFTERNOON...WITH POTENTIAL
FOR OCCASIONAL VISIBILITIES DOWN TO ONE HALF MILE. CEILINGS WILL
MOSTLY RANGE 500 TO 2000 FEET IN THE SNOW. TOTAL SNOWFALL THROUGH
FRIDAY AFTERNOON IS EXPECTED TO BE 3 TO 6 INCHES...WITH POTENTIAL
FOR SLIGHTLY HIGHER AMOUNTS AT KAPA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 2 PM MST
FRIDAY FOR COZ035-036-039>041.
WINTER WEATHER ADVISORY UNTIL 2 PM MST FRIDAY FOR COZ033-034.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...MEIER
LONG TERM...BAKER
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
740 AM MST THU JAN 7 2016
.UPDATE...
ISSUED AT 739 AM MST THU JAN 7 2016
CURRENT RADAR IMAGERY SHOWS LIGHT SNOW IS TRYING TO FILL IN ALONG
THE FRONT RANGE. IN FACT...SOME LIGHT SNOW HAS ALREADY DEVELOPED
IN PORTIONS OF THE METRO AREA PER LATEST OBSERVATIONS FROM
CENTENNIAL AIRPORT. HRRR SEEMS TO HAVE BEST HANDLE ON THIS FOR
NOW...WEAKENING IT DURING THE DIURNAL MINIMA LATER THIS MORNING
INTO EARLY AFTERNOON...AND THEN INCREASING AGAIN THIS EVENING.
CURRENT FORECAST LOOKS ON TRACK...ONLY MINOR POP CHANGES THIS
MORNING TO REFINE AREAS OF LIGHT SNOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM MST THU JAN 7 2016
RADAR AND WEB CAMERAS INDICATE WIDESPREAD LIGHT SNOW HAS MOVED
OVER WESTERN AND CENTRAL COLORADO. LOOKING AT WATER VAPOR
SATELLITE IMAGERY...IT APPEARS DIFFLUENT FLOW ALOFT IS HELPING TO
PRODUCE THIS SNOW. EXPECT THE SNOW TO SLOWLY SHIFT EAST OVER THE
FRONT RANGE MOUNTAINS THIS MORNING. STILL UNCERTAIN IF SNOW WILL
MAKE ONTO THE URBAN CORRIDOR TODAY. IF IT DOES MAKE IT...SNOWFALL
WILL BE LIGHT AND THE SNOW WILL LIKELY MELT ON THE ROADWAYS DUE TO
TEMPERATURES NEAR THE FREEZING POINT. LOWERED POPS FOR TODAY
ACROSS THE DENVER AREA AND EASTERN PLAIN WHERE SNOW LOOKS LESS
CERTAIN. THE BEST CHANCE FOR SNOW LOOKS TO BE LATE THIS AFTERNOON
WITH THE NEXT WAVE MOVING INTO THE DESERT SOUTHWEST. THIS MAY BE
IN TIME FOR THE EVENING COMMUTE.
BETTER CHANCE FOR SNOW WILL BE TONIGHT WHEN THE SECOND WAVE
CURRENTLY MOVING ONTO THE SOUTHERN CALIFORNIA COAST MOVES OVER THE
FOUR CORNERS. THE ECMWF AND GEM CONTINUE TO LEAD THE WAY AND SHOW
AROUND A QUARTER INCH TO A THIRD INCH OF QPF FOR TONIGHT. THE 00Z
GFS IS STARTING TO CATCH UP TO THEM. EVEN THOUGH CONFIDENCE IS HIGH
THAT WE SEE SNOW...CONFIDENCE IN SNOWFALL AMOUNTS REMAINS LOW. A
SURFACE HIGH BUILDING OVER THE NORTHERN ROCKIES AND A SURFACE LOW
OVER NORTHEAST NEW MEXICO/NORTHWEST TEXAS WILL HELP PRODUCE UPSLOPE
FLOW LATE TONIGHT AND INTO FRIDAY. AIRMASS WILL BE MOIST TONIGHT
AND LAPSE RATES WILL BE 6 TO 8 C/KM. SO ANY LIFT WILL LIKELY
PRODUCE LIGHT SNOW.
WILL ISSUE AN ADVISORY FOR THE MOUNTAINS...FOOTHILLS AND DENVER AREA.
EXPECT 5-10 INCHES FOR THE MOUNTAINS WITH 4-8 SOUTHERN FOOTHILLS AND
3-7 FOR THE NORTHERN FOOTHILLS AND DENVER METRO AREA. MAIN IMPACT
FROM THIS SYSTEM WILL BE SNOWPACKED AND ICY ROADS TONIGHT AND FRIDAY
MORNING EVEN IF SNOWFALL AMOUNTS FALL SHORT OF ADVISORY CRITERIA.
SNOW IS EXPECTED TO BEGIN LATE THIS AFTERNOON OR EARLY EVENING AND
MAY CATCH THE EVENING COMMUTE. THE FRIDAY MORNING COMMUTE WILL
LIKELY BE SLOW AND SLIPPERY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 344 AM MST THU JAN 7 2016
THE FORECAST CONUNDRUM OF THE PAST COUPLE OF DAYS HAS IMPROVED SOME
THIS SHIFT WITH BETTER CONTINUITY IN THE 00Z AND 06Z MODEL RUNS.
MODELS HAVE CONVERGED UPON THE UPPER LEVEL CLOSED LOW OVER THE 4-
CORNERS THURSDAY EVENING TRACKING EAST-SOUTHEASTWARD ACRS NRN NEW
MEXICO DURING THE DAY FRIDAY. THERE`S ALSO BETTER AGREEMENT AS TO
WHEN A RATHER STG COLD FRONT WILL DROP SOUTH INTO NERN COLORADO AND
ARRIVE IN THE DENVER METRO AREA. THE LEADING EDGE OF THIS COLDER
AIRMASS APPEARS TO REACH THE DENVER AREA LATE THURSDAY NIGHT...BUT
THE MAIN PUSH OF COLD AIR ARRIVES WITH SFC-600 MB NELY WINDS OF 10-
20KTS DURING THE 12Z-18Z TIME INTERVAL ON FRIDAY AS THE UPPER LOW
PASSES TO OUR SOUTH. THIS IS ALSO THE PERIOD OF GREATEST QG ASCENT
OVER THE AREA...THOUGH NOTHING EXTRAORDINARY BY ANY MEANS. FORCING
ALOFT COMBINED WITH WEAK LEE SLOPE OROGRAPHICS/UPSLOPE FLOW AND A
MOIST LAPSE RATE TO AROUND 600 MBS SHOULD BE SUFFICIENT TO GENERATE
ANOTHER 1.5-4 INCHES OF SNOW ACROSS SRN PORTIONS OF THE I-25 URBAN
CORRIDOR INCLUDING THE DENVER METRO AREA AND ADJACENT FOOTHILLS...
WITH LESSER AMOUNTS IN AREAS TO THE NORTH AND EAST. RIDGE TOPS AND
EAST SLOPES IN MTN ZONES 33-34 COULD ALSO PICK UP ANOTHER 2-5 INCHES
DURING THE DAY FRIDAY. THE WINTER WEATHER ADVISORY FOR SNOW IS
SET TO EXPIRE AT 21Z/FRIDAY.
AFTER 21Z/FRIDAY...MODELS SHOW THE NELY UPSLOPE FLOW ON THE
PLAINS WEAKENING WITH THE CORE OF COLDEST AIR AND MAX SFC PRESSURE
PASSING TO OUR SOUTHEAST. DEPTH OF THE MOISTURE EAST OF THE FRONT
RANGE ALSO GRADUALLY LOWERS AS DRIER AIR BEGINS TO ENTRAIN
DOWNWARD FROM MID-LEVELS IN NWLY FLOW. AS A RESULT SHOULD SEE A
STEADY DECLINE IN SNOWFALL INITIALLY ALONG THE FRONT RANGE AND
EVENTUALLY OUT ACROSS THE PLAINS BY AROUND MIDNIGHT. IF IT WERE
NOT FOR THE LINGERING CLOUD COVER OVERNIGHT TEMPERATURES WOULD
CERTAINTY PLUNGE BELOW ZERO IN MANY AREAS WITH THE FRESH SNOW
COVER AND LIGHT WINDS. HIGH TEMPERATURES ON FRIDAY AT LEAST 10
DEG F LOWER THAN THOSE TODAY DUE TO HEAVY CLOUD COVER...SNOWFALL
AND ONGOING COLD AIR ADVECTION.
LOOKING AHEAD TO THE WEEKEND...TEMPERATURES WILL STRUGGLE TO WARM
WITH LINGERING CLOUD COVER AND WEAK COLD AIR ADVECTION WITH
NORTHWEST FLOW SFC AND ALOFT. A WEAK WEATHER DISTURBANCE/SHORTWAVE
TROUGH MOVING ALONG MODERATE NWLY FLOW ALOFT IS FORECAST BY A
MAJORITY OF THE MODELS TO CLIP NERN COLORADO DURING THE SATURDAY
AFTERNOON/EVENING TIME FRAME. COULD SEE AN UPTICK IN HIGH COUNTRY
SNOWFALL WITH ITS PASSAGE AS WELL AS A SLIGHT CHANCE OF LIGHT SNOW
ON THE PLAINS...MAINLY ACROSS THE NORTHEAST CORNER OF THE CWA.
ADDITIONAL SNOW AMOUNTS GENERALLY LESS THAN 2 INCHES FOR THE HIGH
COUNTRY AND PRETTY MUCH NOTHING ON THE PLAINS. TEMPERATURE GUIDANCE
NOW IN BETTER AGREEMENT WITH HIGHS IN THE 20S ON THE PLAINS BOTH
DAYS AND TEENS/LOW 20S IN THE MTNS/HIGH VALLEYS. HIGH MTN VALLEY
LOWS WILL TURN QUITE COLD AGAIN BUT NO WHERE AS BITTER COLD AS THEY
WERE SEVERAL DAYS AGO.
NEXT WEEK LOOKS DRY AND WARMER WITH A HIGH RIDGE BUILDING IN FROM
THE WEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 739 AM MST THU JAN 7 2016
AREAS OF LIGHT SNOW DEVELOPING ALONG THE FRONT RANGE THIS MORNING.
THIS IS A FEW HOURS AHEAD OF TIME AND ONLY ADVERTISED BY
MESOSCALE MODELS OF YESTERDAY. NOW...SEEMS HRRR CATCHING BACK ON.
MOST OF THIS SNOW SHOULD REMAIN LIGHT WITH POTENTIAL FOR MINOR
SNOW ACCUMULATIONS LESS THAN 1 INCH...AND SOME MELTING EXPECTED ON
PAVED SURFACES. BAND OF LIGHT SNOW IS IN THE KAPA TO KDEN
CORRIDOR...BUT MAY SHIFT TO KBJC AND KFNL BEFORE A GRADUAL
WEAKENING EXPECTED TOWARD 18Z- 20Z.
OTHERWISE...A SERIES OF PACIFIC SYSTEMS WILL BRING MOISTURE TO
THE AREA. CLOUDS WILL LOWER THROUGH THE DAY WITH ILS LANDINGS.
CEILINGS ARE EXPECTED TO FALL BELOW 3000 FEET WITH AREAS OF LIGHT
SNOW THIS MORNING...AND THEN BECOME MORE PERSISTENT AFTER 21Z THIS
AFTERNOON. WIDESPREAD SNOW IS EXPECTED AFTER 00Z WITH VISIBILITY
RANGING FROM 1 TO 3 MILES. CEILINGS WILL BE 500 TO 2000 FEET.
WINDS WILL BE LIGHT AND TURN NORTHEAST AROUND 06Z. TOTAL SNOWFALL
AT KDEN THROUGH 18Z FRIDAY IS EXPECTED TO BE 3 TO 5 INCHES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 2 PM MST
FRIDAY FOR COZ035-036-039>041.
WINTER WEATHER ADVISORY UNTIL 2 PM MST FRIDAY FOR COZ033-034.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...MEIER
LONG TERM...BAKER
AVIATION...BARJENBRUCH/MEIER
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
231 PM EST THU JAN 7 2016
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE
NORTH THROUGH FRIDAY. A WEAKENING UPPER-LEVEL DISTURBANCE WILL
HELP CAUSE A CHANCE OF SHOWERS LATE TONIGHT INTO FRIDAY. A MORE
SIGNIFICANT FRONTAL SYSTEM WILL MOVE INTO THE REGION SATURDAY AND
SHIFT EAST OF THE AREA LATE SATURDAY NIGHT. IT WILL BE DRY WITH
BREEZY WEST WINDS BEHIND THE FRONT SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND INTO THE FORECAST
AREA FROM THE NORTH. MOISTURE AND INSTABILITY ASSOCIATED WITH A
MID-LEVEL SHORTWAVE TROUGH WILL MOVE INTO THE AREA TONIGHT. THE
GREATER LIFT WILL OCCUR LATE. THE HRRR SUGGESTS SCATTERED SHOWERS
WILL BEGIN MOVING INTO THE CSRA FROM THE SOUTHWEST AROUND
MIDNIGHT. THE DAMPENING UPPER SYSTEM WITH WEAK ISENTROPIC LIFT
COMBINED WITH AN AVERAGE OF THE NAM AND GFS MOS PLUS SREF GUIDANCE
SUPPORTS CHANCE POPS. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE MODELS DISPLAY SURFACE RIDGING EXTENDING INTO THE FORECAST
AREA FROM THE NORTH THROUGH FRIDAY NIGHT. MOISTURE AND INSTABILITY
ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH WILL LINGER INTO
FRIDAY MORNING. THE MODELS SHOW SHALLOW MOISTURE FRIDAY AFTERNOON
AND NIGHT BUT SOME CONTINUED WEAK ISENTROPIC LIFT. HAVE FORECASTED
A DIMINISHED RAIN CHANCE FRIDAY AFTERNOON AND NIGHT. THE
NAM...GFS...AND ECMWF INDICATE MOISTURE BECOMING DEEP SATURDAY
AHEAD OF A WARM FRONT AND APPROACHING COLD FRONT. THE MODELS
DISPLAY THE DEEPEST MOISTURE LATE SATURDAY AFTERNOON AND WE HAVE
PLACED THE HIGHEST POPS DURING THAT TIME. THE NAM AND ECMWF
INDICATED RAIN AMOUNTS AROUND 0.25 OF AN INCH. THE SREF MEAN WAS
NEAR 0.50 AND GFS LESS THAN 0.25 OF AN INCH. WE USED AN AVERAGE
OF THE GUIDANCE. THE NAM AND GFS INDICATE HIGH SHEAR WITH AN H85
JET OF 35 TO 50 KNOTS. THE NAM HAD THE GREATER SHEAR. DESPITE THE
STRONG SHEAR THE SEVERE THREAT SHOULD REMAIN LOW BECAUSE OF A LACK
OF SURFACE-BASED INSTABILITY. THE NAM DISPLAYED SURFACE-BASED LI/S
RANGING FROM 4 IN THE WEST TO NEAR 0 IN THE EAST LATE SATURDAY
AFTERNOON INTO THE EVENING. THE NAM AND GFS HAD CROSS TOTALS IN
THE MIDDLE 20S AND A FEW ELEVATED THUNDERSTORMS MAY OCCUR. EXPECT
DRYING BEHIND THE COLD FRONT LATE SATURDAY NIGHT. USED THE LOWER
HIGH TEMPERATURE GUIDANCE FRIDAY AND SATURDAY BECAUSE OF A WEDGE
PATTERN. THE LOW TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE GFS AND ECMWF INDICATE A DRY PATTERN DURING THE MEDIUM-RANGE
PERIOD. THE MODELS DEPICT LITTLE MOISTURE ASSOCIATED WITH A
REINFORCING COLD FRONT WEDNESDAY. BREEZY CONDITIONS WILL LIKELY
OCCUR BEHIND THE COLD FRONT SUNDAY. IT MAY BE BREEZY AGAIN
WEDNESDAY BECAUSE OF THE REINFORCING COLD FRONT. THE
GFS...ECMWF...AND EKD MOS HAVE POPS LESS THAN OR EQUAL TO 20
PERCENT THOUGH THE PERIOD. THE MOS HAS ABOVE NORMAL TEMPERATURES
SUNDAY BUT WIND SHOULD MAKE IT FEEL COOLER. THE MOS HAS NEAR OR
BELOW NORMAL TEMPERATURES DURING THE REST OF THE PERIOD.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
BAND OF EARLIER LOW CLOUDINESS HAS LIFTED...WITH VFR CONDITIONS
EXPECTED TO CONTINUE AT OUR TERMINALS THIS AFTERNOON INTO THE EARLY
EVENING. A NE LOW LEVEL FLOW IS EXPECTED TO CONTINUE THROUGH THE TAF
PERIOD WITH WEAK SURFACE HIGH PRESSURE RIDGING DOWN THE EASTERN
SEABOARD AND SURFACE LOW WELL OFFSHORE. THIS MAY PROVIDE
FOR LOWER CLOUDINESS...AND POSSIBLY FOG...TO REDEVELOP AGAIN
TONIGHT TO OUR NE EARLY TONIGHT AND SHIFT SW INTO OUR FORECAST
AREA...PER LATEST HIGH RESOLUTION MODELS. BASED ON
CONTINUITY...AND ON RELATIVE CONSISTENCY IN MODEL GUIDANCE...THINK
CONFIDENCE OF IFR CIGS TONIGHT AND FRIDAY MORNING IS HIGH...BUT
CONFIDENCE ON THE EXTENT OF RESTRICTIONS TO VSBYS LIMITED. AT THIS
TIME...WILL INDICATE CONDITIONS DETERIORATING TO IFR
TONIGHT...HITTING THE CIGS HARDER THAN THE VSBYS FOR NOW. WEAK
UPPER DISTURBANCE APPROACHING FROM THE WEST AND RESULTANT WEAK
ISENTROPIC LIFT EXPECTED TO PROVIDE CHANCE OF LIGHT RAIN LATE
TONIGHT AND FRIDAY MORNING. THE LIGHT RAIN ACTIVITY MAY DICTATE
ONLY SLOW IMPROVEMENT...IF ANY...IN FLIGHT CATEGORIES FRIDAY
MORNING.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE FRIDAY
AFTERNOON. MVFR TO IFR RESTRICTIONS EXPECTED FRIDAY
NIGHT...SATURDAY AND SATURDAY NIGHT....WITH CHANCE OF RAIN SAT/SAT
NT. NO RESTRICTIONS EXPECTED SUNDAY/MONDAY...THOUGH BREEZY
CONDITIONS POSSIBLE SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS POCATELLO ID
741 PM MST FRI JAN 8 2016
.UPDATE...QUICK UPDATE TO SPREAD FOG THROUGHOUT A GREATER PORTION
OF THE SNAKE PLAIN TONIGHT. AREA WEB CAMS SHOWING FOG HAS BECOME
MORE EXTENSIVE THROUGH THE UPPER SNAKE PLAIN ESPECIALLY ACROSS
THE ARCO DESERT. BUFR SOUNDINGS FROM RAP AND HRRR FAVOR FOG
DEVELOPMENT AT IDAHO FALLS BUT LOW STRATUS THERE MAY HOLD MOST OF
IT BACK. HAVE ISSUED A DENSE FOG ADVISORY FOR THE UPPER SNAKE
PLAIN ZONE CONTAINING MOST OF THE ARCO DESERT BUT WORDED THAT
MOST OF THE FOG WILL REMAIN WEST OF INTERSTATE 15. THE BAND OF
FOG DOES STRETCH INTO THE EASTERN MAGIC VALLEY ALONG THE
FOOTHILLS OF THE CENTRAL MTNS WITH SOME LOWERED VISIBILITIES
PUSHING UP THE WOOD RIVER VALLEY. HAVE HELD BACK ON ISSUING THE
DENSE FOG ADVISORY IN THESE LOCATIONS SINCE THE BAND DOES NOT
APPEAR TO SPREAD MUCH FARTHER THAN US ROUTE 20 AND VISIBILITIES
AREN`T AS RESTRICTED SOUTH OF CRATERS OF THE MOON NM. ONLY OTHER
CONCERN IS WEAK ENHANCEMENT OF COOLER TOPPED CLOUDS IN THIN BAND
MOVING INTO THE SOUTHERN/EASTERN HIGHLANDS. THERE ARE SOME WEAK
RADAR RETURNS WITH THIS FEATURE SO DO EXPECT LIGHT SNOW WITH IT.
WEAK POP ACROSS THE SOUTHERN/EASTERN HIGHLANDS SHOULD SUFFICE
GIVEN LOW CONFIDENCE AND LOW QPF AMOUNTS. HAVE MODIFIED OVERNIGHT
GRIDS FOR ABOVE. DMH
&&
.PREV DISCUSSION... /ISSUED 125 PM MST FRI JAN 8 2016/
SHORT TERM...LOW STRATUS CLOUDS PERSIST IN THE SNAKE PLAIN THE
NEXT COUPLE OF DAYS AND THAT WILL BE A PROBLEM FOR TEMPERATURES.
CURRENT FORECAST KEEPS NIGHTTIME LOWS TO THE WARM SIDE OF
GUIDANCE AND DAYTIME HIGHS THE SAME OR A DEGREE OR SO COOLER. THE
DIFFERENCE GROWS BY MONDAY WITH RESPECT TO THE NIGHTTIME LOWS.
THERE ARE A COUPLE OF MINOR DISTURBANCES IN WEST TO NORTHWEST FLOW
ALOFT TONIGHT AND SATURDAY TO WARRANT KEEPING A SLIGHT CHANCE OF
SNOW IN THE FORECAST. THE EASTERN HIGHLANDS ALONG THE WYOMING
BORDER COULD SEE UP TO AN INCH OF SNOW. MOST OTHER AREAS WILL SEE
VERY LITTLE ACCUMULATION. BY SATURDAY EVENING...A DISTURBANCE
CROSSING OREGON TOWARDS UTAH WILL BRUSH CASSIA COUNTY AREA WITH
SOME LIMITED SNOW. MAGIC MOUNTAIN MAY PICK UP ABOUT AND INCH OF
SNOW. SUNDAY AND MONDAY A HIGH PRESSURE RIDGE WILL PROGRESS OVER
IDAHO KEEPING INVERSION CONDITIONS OVER THE SNAKE PLAIN.
LONG TERM...MON NIGHT THROUGH NEXT FRI NIGHT. 500MB LONGWAVE
PATTERN CHANGES LITTLE DURING THIS PERIOD. THERE IS A WESTERN U.S.
RIDGE THAT VERY SLOWLY MOVES INLAND...BY THU NIGHT OVER EASTERN
IDAHO. THEN THERE IS THE POLAR VORTEX/EASTERN CONUS TROUGH. WITH
ONLY MINOR WAVES MOVING THROUGH THIS FLOW...THIS WOULD MEAN LIGHT
SNOWFALL WITH NORMAL TO COOL TEMPERATURES IN THE GENERAL NORTHWEST
FLOW FOR THIS PERIOD. FACTORING IN THE SHORTWAVES...THE ECMWF AND
GFS COME TO DIFFERENT SOLUTIONS...ESPECIALLY BY THU. THE ECMWF IS
VERY DRY WITH THE RIDGE BUILDING BY WED NIGHT TO BLOCK THE
SHORTWAVES TO THE NORTHEAST AND AWAY FROM THE GEM STATE ENTIRELY TO
THE END OF THE FORECAST PERIOD. THIS MEANS COLDER NIGHTS WITH
CLEARER SKIES...TEMPERATURES IN THE TEENS. THE GFS IS WETTER WITH
MILDER OVERNIGHT LOWS AND SLIGHTLY WARMER AFTERNOON HIGHS WITH THE
WARMER START TO EACH DAY. HAVE TRIED TO BUILD A COMPROMISE SOLUTION
WITH A BIAS SLIGHTLY TOWARDS THE ECMWF DUE TO THE NORTHERN
OSCILLATION EXPECTED TO CONTINUE FOR ANOTHER WEEK AT LEAST...AS THIS
WOULD FAVOR A HIGH-AMPLITUDE WEST COAST RIDGE. THE OVERALL TREND
COMPARED TO YESTERDAY IS ALSO A DRYING TREND...AS EVEN THE ECMWF HAD
PRECIPITATION EXPECTED AT SOME SPOT IN THE FORECAST AREA FOR EACH
DAY. SO ALL POPS STAY BELOW 30 PERCENT EVEN FOR THE MOUNTAINS AND
MANY LOWER ELEVATIONS WILL NOT EVEN MENTION A PRECIPITATION THREAT
ON SOME DAYS. ALSO DO NOT SEE ANY STORM POWERFUL ENOUGH OR MAKING A
CLOSE ENOUGH APPROACH TO GENERATE ANY SIGNIFICANT WIND. MESSICK
AVIATION...STRATUS...FOG...AND OCCASIONAL LIGHT SNOW WILL ONCE
AGAIN WREAK HAVOC...MAINLY IN THE SNAKE RIVER PLAIN. COULD SEE SOME
PROBLEMS ALSO AT KSUN DURING THE AFTERNOON AND EARLY EVENING WITH
LIGHT SNOW MOVING IN AND OUT. ONCE AGAIN...THE MOST AFFECTED
AIRDROME IS KBYI...ESPICALLY DURING THE EVENING. BUT KIDA AND KPIH
WILL HAVE CIG AND VSBY PROBLEMS IN THE MORNING...DUELING WITH THE
STRATUS AND FOG. VERY MUCH A LOW CONFIDENCE FORECAST AS FAR AS THE
MAGNITUDE OF THE PROBLEM. THERE WAS SOME LIGHT SNOW AT KBYI AND KPIH
WHICH WOULD HELP SUPPLY THE NEEDED BOUNDARY LAYER MOISTURE...SO AM
EXPECTING IT BRING AT LEAST IFR CONDITIONS FOR THE MORNING HOURS
AS THE AIRPORTS OPEN. MESSICK
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM MST SATURDAY FOR IDZ020.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
932 PM EST FRI JAN 8 2016
.SYNOPSIS...
ISSUED AT 904 PM EST FRI JAN 8 2016
THE RAIN CHANCES DECREASE FOR TONIGHT INTO SATURDAY AS THE FIRST
LOW LIFTS NORTH OF THE REGION. BUT THE RAIN CHANCES BEGIN TO
INCREASE AGAIN FOR THE SOUTH MID DAY SATURDAY AND FOR THE NORTH
SATURDAY EVENING AS A SECOND LOW PRESSURE APPROACHES FROM THE
SOUTHWEST. THEN DURING SATURDAY NIGHT AS THE LOW PROGRESSES
NORTHEASTWARD AND TEMPERATURES DROP THE RAIN WILL CHANGE OVER TO
SNOW. BY SUNRISE SUNDAY THE LOW WILL BE TO THE NORTHEAST OF THE
REGION AND ALL PRECIPITATION WILL BE SNOW. LOW TEMPERATURES
TONIGHT WILL BE IN THE LOWER 40S AS THE NORTHERN PART OF THE
REGION ALSO SEES FOG. HIGH TEMPERATURES ON SATURDAY WILL RANGE
FROM THE LOWER 40S IN SOUTHERN MICHIGAN TO THE LOWER 50S NEAR THE
OHIO RIVER.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 351 PM EST FRI JAN 8 2016
ANOTHER BATCH OF RAIN (MORE SHOWERY IN NATURE WHEN COMPARED WITH
WHAT FELL EARLIER TODAY) WILL PIVOT THROUGH THIS EVENING INTO THE
EARLY OVERNIGHT AS A WELL DEFINED VORT MAX AND POCKET OF STEEPER
MID LEVEL LAPSE RATES LIFT NORTHEAST THROUGH THE LOWER LAKES.
TRAILING FRONTAL BOUNDARY THEN SETTLES IN TONIGHT INTO SATURDAY.
FORCING WANES WITH WEAK HEIGHT RISES IN BETWEEN UPPER LEVEL
WAVES...BUT STILL CANNOT RULE OUT A FEW LIGHT SHOWERS AND PATCHY
DRIZZLE IN THE VICINITY OF THIS FEATURE GIVEN AMPLE BOUNDARY LAYER
MOISTURE. AREAS OF FOG WILL ALSO REMAIN POSSIBLE THROUGH SATURDAY
MORNING ACROSS MAINLY NNW ZONES CLOSER TO SFC TROUGH.
MILD/OVERCAST OTHERWISE WITH RAIN LIKELY FILLING BACK IN ACROSS
WESTERN ZONES LATE SATURDAY AFTERNOON.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 351 PM EST FRI JAN 8 2016
SHRTWV ROUNDING BASE OF SWRN CONUS TROF TODAY WILL LIFT NE FROM THE
SRN PLAINS SATURDAY AND THROUGH THE OHIO VALLEY SATURDAY NIGHT WITH
ASSOCIATED SFC LOW MOVG FROM THE SRN PLAINS TO THE LWR GRTLKS
CAUSING RAIN CHANGING TO SNOW ACROSS OUR AREA. FCST TRACK FAVORS
EARLIER CHANGEOVER... HEAVIER SNOW IN 3-5" RANGE NW, TAPERING OFF TO
<1" SE. SNOW WILL BE HEAVY/WET INITIALLY PREVENTING
BLOWING/DRIFTING... BUT AS COLDER AIR ARRIVES AND WINDS PICK UP LATE
SAT NGT AND SUN AREAS OF BLOWING/DRIFTING SNOW EXPECTED ACROSS THE
NW PORTION OF CWA WHERE HEAVIEST ACCUMS OCCUR AND LES DVLPS. QUICK
TEMP DROP SAT NGT/SUNDAY WILL ALSO PROMOTE ICY ROAD CONDITIONS AS
MELTED SNOW REFREEZES. TOTAL SNOW ACCUMS BY SUNDAY EVE EXPECTED IN
THE 3-7" RANGE NW 1/3 OF CWA... HEAVIEST FAR NW IN COUNTIES NEAR
LAKE MICHIGAN. THIS IS MARGINAL FOR WARNING TYPE ACCUMS... BUT GIVEN
EXPECTATION OF STRONG WINDS AND FALLING TEMPS ISSUED A WINTER STORM
WATCH FOR THE NW FOR THIS TIME FRAME.
DEEP CLOSED LOW FORMING OVER SERN CANADA BY EARLY NEXT WEEK
EXPECTED TO MOVE VERY LITTLE DURING THE WEEK RESULTING IN BLO NORMAL
TEMPS ACROSS OUR AREA WHICH COMBINED WITH W-NW FLOW WILL RESULT
PERSISTENT LES NW... ENHANCED AROUND TUE AND THU BY SHRTWVS MOVG
THROUGH THE BASE OF THE TROF ACROSS THE GRTLKS. MEDIUM RANGE MODELS
HAVE HAD POOR RUN-RUN CONTINUITY ON HOW LONG THIS PATTERN WILL
PERSIST WITH 00Z RUNS SUGGESTING IT WOULD BREAK DOWN BY NEXT WEEKEND
AND LATEST RUNS KEEPING THE COLD AIR IN LONGER. COMPROMISED WITH A
SLOW CLIMB IN TEMPS FRI-SAT... BUT CONFIDENCE ON WARM-UP LATE IN THE
PERIOD IS LOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 626 PM EST FRI JAN 8 2016
FUEL ALT CONDS LIKELY THIS PD AS LOW VSBYS/CIGS PERSIST IN
STRATUS/FOG ASSOCD/W WMFNTL BNDRY LIFTING THROUGH THE TERMINALS.
WILL SLW PRIOR IMPROVEMENT NOTED IN 18Z KFWA TAF ERLY THIS
EVENING OTRWS FOLLOW SIMILAR TREND AFT MID EVENING IN LIGHT OF
DEEPENING WARM SECTOR AND PREDICATED SOMEWHAT BTR BNDRY LYR MIXING
DVLPG PER RAP FCST SNDGS. KSBN XPCD TO REMAIN IN THE SOUP AS LIFR
CIGS PERSIST AND BNDRY STALLS INVOF. HWVR W/INCREASING BNDRY LYR
FLW VSBYS XPCD TO IMPROVE HERE THROUGH AFT MID EVENING TIED TO EWD
PROGRESSION OF SHRA OUT OF NE IL AND INCREMENTAL RAMP TO VEERING
SWRLY GRADIENT FLW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
FOR INZ003>006-012>014.
MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
FOR MIZ077>080.
OH...NONE.
LM...GALE WARNING FROM 11 PM SATURDAY TO 7 PM EST SUNDAY FOR LMZ043-
046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...STEINWEDEL
LONG TERM...JT
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
627 PM EST FRI JAN 8 2016
.SYNOPSIS...
ISSUED AT 1201 PM EST FRI JAN 8 2016
AREAS OF LIGHT RAIN AND DRIZZLE CAN BE EXPECTED THIS EVENING AS A
WARM FRONT LIFTS INTO THE REGION. MAINLY DRY CONDITIONS ARE THEN
EXPECTED LATER TONIGHT INTO EARLY SATURDAY AFTERNOON WITH
TEMPERATURES HOLDING IN THE UPPER 30S TO MID 40S.
RAIN DEVELOPING LATER SATURDAY AFTERNOON WILL CHANGE OVER TO SNOW
FROM WEST TO EAST SATURDAY NIGHT INTO EARLY SUNDAY MORNING...WITH
SEVERAL INCHES OF SNOW ACCUMULATION POSSIBLE ACROSS NORTHWEST
INDIANA AND SOUTHWEST LOWER MICHIGAN. IT WILL TURN MUCH COLDER
SUNDAY INTO NEXT WEEK...WITH LAKE EFFECT SNOW SHOWERS AND
ADDITIONAL ACCUMULATIONS POSSIBLE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 351 PM EST FRI JAN 8 2016
ANOTHER BATCH OF RAIN (MORE SHOWERY IN NATURE WHEN COMPARED WITH
WHAT FELL EARLIER TODAY) WILL PIVOT THROUGH THIS EVENING INTO THE
EARLY OVERNIGHT AS A WELL DEFINED VORT MAX AND POCKET OF STEEPER
MID LEVEL LAPSE RATES LIFT NORTHEAST THROUGH THE LOWER LAKES.
TRAILING FRONTAL BOUNDARY THEN SETTLES IN TONIGHT INTO SATURDAY.
FORCING WANES WITH WEAK HEIGHT RISES IN BETWEEN UPPER LEVEL
WAVES...BUT STILL CANNOT RULE OUT A FEW LIGHT SHOWERS AND PATCHY
DRIZZLE IN THE VICINITY OF THIS FEATURE GIVEN AMPLE BOUNDARY LAYER
MOISTURE. AREAS OF FOG WILL ALSO REMAIN POSSIBLE THROUGH SATURDAY
MORNING ACROSS MAINLY NNW ZONES CLOSER TO SFC TROUGH.
MILD/OVERCAST OTHERWISE WITH RAIN LIKELY FILLING BACK IN ACROSS
WESTERN ZONES LATE SATURDAY AFTERNOON.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 351 PM EST FRI JAN 8 2016
SHRTWV ROUNDING BASE OF SWRN CONUS TROF TODAY WILL LIFT NE FROM THE
SRN PLAINS SATURDAY AND THROUGH THE OHIO VALLEY SATURDAY NIGHT WITH
ASSOCIATED SFC LOW MOVG FROM THE SRN PLAINS TO THE LWR GRTLKS
CAUSING RAIN CHANGING TO SNOW ACROSS OUR AREA. FCST TRACK FAVORS
EARLIER CHANGEOVER... HEAVIER SNOW IN 3-5" RANGE NW, TAPERING OFF TO
<1" SE. SNOW WILL BE HEAVY/WET INITIALLY PREVENTING
BLOWING/DRIFTING... BUT AS COLDER AIR ARRIVES AND WINDS PICK UP LATE
SAT NGT AND SUN AREAS OF BLOWING/DRIFTING SNOW EXPECTED ACROSS THE
NW PORTION OF CWA WHERE HEAVIEST ACCUMS OCCUR AND LES DVLPS. QUICK
TEMP DROP SAT NGT/SUNDAY WILL ALSO PROMOTE ICY ROAD CONDITIONS AS
MELTED SNOW REFREEZES. TOTAL SNOW ACCUMS BY SUNDAY EVE EXPECTED IN
THE 3-7" RANGE NW 1/3 OF CWA... HEAVIEST FAR NW IN COUNTIES NEAR
LAKE MICHIGAN. THIS IS MARGINAL FOR WARNING TYPE ACCUMS... BUT GIVEN
EXPECTATION OF STRONG WINDS AND FALLING TEMPS ISSUED A WINTER STORM
WATCH FOR THE NW FOR THIS TIME FRAME.
DEEP CLOSED LOW FORMING OVER SERN CANADA BY EARLY NEXT WEEK
EXPECTED TO MOVE VERY LITTLE DURING THE WEEK RESULTING IN BLO NORMAL
TEMPS ACROSS OUR AREA WHICH COMBINED WITH W-NW FLOW WILL RESULT
PERSISTENT LES NW... ENHANCED AROUND TUE AND THU BY SHRTWVS MOVG
THROUGH THE BASE OF THE TROF ACROSS THE GRTLKS. MEDIUM RANGE MODELS
HAVE HAD POOR RUN-RUN CONTINUITY ON HOW LONG THIS PATTERN WILL
PERSIST WITH 00Z RUNS SUGGESTING IT WOULD BREAK DOWN BY NEXT WEEKEND
AND LATEST RUNS KEEPING THE COLD AIR IN LONGER. COMPROMISED WITH A
SLOW CLIMB IN TEMPS FRI-SAT... BUT CONFIDENCE ON WARM-UP LATE IN THE
PERIOD IS LOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 626 PM EST FRI JAN 8 2016
FUEL ALT CONDS LIKELY THIS PD AS LOW VSBYS/CIGS PERSIST IN
STRATUS/FOG ASSOCD/W WMFNTL BNDRY LIFTING THROUGH THE TERMINALS.
WILL SLW PRIOR IMPROVEMENT NOTED IN 18Z KFWA TAF ERLY THIS
EVENING OTRWS FOLLOW SIMILAR TREND AFT MID EVENING IN LIGHT OF
DEEPENING WARM SECTOR AND PREDICATED SOMEWHAT BTR BNDRY LYR MIXING
DVLPG PER RAP FCST SNDGS. KSBN XPCD TO REMAIN IN THE SOUP AS LIFR
CIGS PERSIST AND BNDRY STALLS INVOF. HWVR W/INCREASING BNDRY LYR
FLW VSBYS XPCD TO IMPROVE HERE THROUGH AFT MID EVENING TIED TO EWD
PROGRESSION OF SHRA OUT OF NE IL AND INCREMENTAL RAMP TO VEERING
SWRLY GRADIENT FLW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
FOR INZ003>006-012>014.
MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
FOR MIZ077>080.
OH...NONE.
LM...GALE WARNING FROM 11 PM SATURDAY TO 7 PM EST SUNDAY FOR LMZ043-
046.
&&
$$
SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...JT
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
942 PM CST FRI JAN 8 2016
.UPDATE...
ISSUED AT 942 PM CST FRI JAN 8 2016
VISIBILITIES CONTINUE TO IMPROVE THIS EVENING AS THE CYCLONIC FLOW
BEHIND THE SURFACE LOW LIFTING INTO UPPER MI WAS RESULTING IN
INCREASING NW WINDS AND COLD AIR ADVECTION IN THE CYCLONIC NW
FLOW. HAVE ALLOWED THE FOG ADVISORY TO EXPIRE OVER THE REMAINDER
OF EASTERN IA...BUT WILL LEAVE NW IL AS IS FOR NOW AS SEVERAL SURFACE
OBS STILL IN THE QUARTER TO HALF MILE RANGE.
UPSTREAM ACROSS CENTRAL AND NORTHERN IA AND SOUTHERN MN...THE
PRECIPITATION HAS CHANGED OVER TO LIGHT SNOW...WHICH IS REPORTEDLY
CAUSING SLICK TRAVEL CONDITIONS THERE DUE TO THE INITIAL WARM
PAVEMENT TEMPERATURES ICING OVER WITH THE LIGHT ACCUMULATING SNOW
AND FALLING TEMPERATURES. THIS CHANGEOVER IS LIKELY REACHING INTO
PORTIONS OF BUCHANAN...DELWARE AND BENTON COUNTIES BASED ON
UPSTREAM TRENDS IN OBSERVATIONS. IN THESE COUNTIES...AND ALL OF
THE DVN FORECAST AREA...PAVEMENT TEMPERATURES ARE SHOWING UP WELL
ABOVE 32 DEGREES THIS EVENING. THE INCOMING AXIS OF SNOW WITH
UPSTREAM VISIBILITIES IN A 3 TO 4 MILE RANGE...SUGGESTS OVERNIGHT
TOTALS WELL BELOW AN INCH. THIS MAY LEAD TO A PERIOD OF SLICK
ROADS AS IT MAY ICE OVER ON THE INITIAL WARM PAVEMENT WITH THE
INCOMING COLD AIRMASS.
GIVEN THE LATE NIGHT OCCURRENCE OF THIS POSSIBLE IMPACT...VERY
LIGHT AMOUNTS WELL BELOW USUAL THRESHOLDS...AND THE MID SEASON
OCCURRENCE...WILL NOT BE ISSUING WINTER HEADLINES AT THIS TIME.
INSTEAD...WILL BE USING SPECIAL WEATHER STATEMENTS TO HIGHLIGHT
THE ANTICIPATED TRAVEL IMPACT.
&&
.SYNOPSIS...
ISSUED AT 344 PM CST FRI JAN 8 2016
LATEST SFC ANALYSIS WAS INDICATING A LOW CENTER MOVING NORTHWARD
ACRS THE WEST CENTRAL DVN CWA ATTM...WITH A ASSOCIATED FRONTAL
SYSTEM TRAILING DOWN INTO SOUTHWESTERN AR AND NORTHERN TX. THE UPPER
LEVEL LOW WAS NOTED ON WATER VAPOR IMAGERY ACRS NORTHEASTERN MO INTO
THE SOUTHERN CWA...WITH A STRONGER WAVE FURTHER UPSTREAM IN A L/W
TROF BASE DIGGING TOWARD WESTERN TX.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
TONIGHT...ASSESSING THE LATEST TRENDS AND LLVL CONVERGENT FLOW
PROPAGATION ASSOCIATED WITH THE PASSING SFC WAVE...HAVE EXTENDED THE
FOG ADVISORY TO 03Z /9 PM CST/ FOR THE WESTERN 2/3S...AND THE
NORTHWESTERN IL COUNTIES NOW INCLUDING THE EASTERN I80 CORRIDOR TIL
06Z /MIDNIGHT CST/. BUT THESE END TIMES MAY BE A BIT GENEROUS AND
THE FOLLOWING SHIFT WILL BE ABLE TO CHOP AWAY FROM THE WEST AND
SOUTH AS THE EVENING PROGRESSES...AS THE LLVL FLOW VEERS TO THE
WEST/NORTHWEST AND INCREASES. LATEST RUN HRRR VSBY PROGS NOW SHIFT
THE 1/4 MILE OR LESS VSBYS EAST OF THE MS RIVER BY 03Z THIS
EVENING.
LINGERING AREAS OF RAIN AND DRIZZLE THIS AFTERNOON AND EARLY EVENING
TO ROLL OFF TO THE NORTHEAST...WITH JUST SPOTTY LIGHTER PRECIP
WRAPPING IN BEHIND THE DEPARTING CYCLONE OUT OF NORTHWESTERN IA.
WITH POST-FRONTAL TOP DOWN COOLING...THIS PRECIP TO CHANGE OVER TO A
LIGHT RAIN/SNOW MIX THEN TO ALL LIGHT WET SNOW OVERNIGHT FROM WEST
TO EAST. LINGERING MILD GROUND TEMPS AND LACK OF PRECIP INTENSITY
SUGGESTS A WET DUSTING TO A TENTH OF AN INCH AT BEST IN AREAS THAT
GET IN ON SOME SNOW LATER TONIGHT. NORTHWEST WINDS TO RAMP UP AFTER
MIDNIGHT TO 15 TO 25 MPH IN INCOMING CANADIAN HIGH PRESSURE GRADIENT
ESPECIALLY ALONG AND WEST OF THE MS RIVER. LLVL COLD CONVEYOR TO
BE WELL IN FLUX ACRS THE AREA BY SAT MORNING.
SATURDAY...12 HR HIGH TEMPS TO OCCUR IN THE MORNING WITH FALLING
TEMPS THRU THE REST OF THE DAY. TIGHT PRESSURE GRADIENT AND STRONG
LLVL COLD AIR ADVECTION TO DIVE BRISK NORTHWEST SFC WINDS OF 15 TO
25+ MPH AND GUSTS WELL OVER 30 MPH AT TIMES. SOME LIGHT SNOW SHOWERS
OR FLURRIES MAY GET WRUNG OUT OF ANY CLOUD DECK WITH ENOUGH
SATURATED DEPTH IN THIS CAA PROCESS ESPECIALLY NORTH OF I80 BUT
LITTLE IF ANY SNOW ACCUM EXPECTED WITH THIS ACTIVITY. THEN ALL EYES
TURN TO THE MAIN SOUTHERN PLAINS LOW PRESSURE WAVE EJECTING
NORTHEASTWARD TOWARD THE MOUTH OF THE OH RIVER VALLEY BY SAT
EVENING. BULK OF THE 12Z RUN MODEL SOLUTIONS HAVE CAUGHT ON TO THE
CURRENT STRONGER SOUTHEASTWARD DIGGING PROCESS OF THE WAVE AIDED
BY UPPER JET PUNCH IN THAT DIRECTION ON IT/S WESTERN FLANK. THUS
THEY HAVE CONTINUED TO TREND FURTHER SOUTHEAST WITH THE MAIN STORM
PROPAGATION PATH. WILL ADJUST SNOW AMOUNTS ON ITS FAR NORTHWESTERN
FLANK OF IT/S DEF ZONE FURTHER DOWN AND EAST AS WELL WITH THE
LATEST THINKING. THIS ONLY PRODUCES UP TO AN INCH OF SNOW BY 00Z
SUNDAY SOUTHEAST OF A LINE GENERALLY FROM SOUTHWEST OF MACOMB
IL...TO PRINCETON IL. FURTHER WEST TOWARD THE MS RIVER MAY ONLY
GET A TENTH OR TWO...AND AREAS WEST OF THE MS RIVER MAY STAY DRY
BESIDES THE LIGHT SNOW/ FLURRIES POSSIBLE NORTH OF I80 GETTING
WRUNG OUT OF WRAP AROUND CLOUD DECK IN THE COLD AIR ADVECTION
PROCESS MENTIONED ABOVE. ANY FURTHER ADJUSTMENT EAST MEANS A NON-
EVENT/MISS FOR THE DVN CWA. ..12..
.LONG TERM...(SATURDAY NIGHT THROUGH NEXT FRIDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
COLD MID JANUARY WEATHER AND DRY TO MOSTLY DRY THROUGH LATE NEXT
WEEK.
LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE
WITH LIMITED SENSIBLE WEATHER ISSUES. MAIN CHALLENGES WILL BE BOUTS
OF FLURRIES AND POSSIBLY VERY LIGHT SNOW ON MONDAY/MONDAY NIGHT AND
AGAIN LATE NEXT WEEK. OTHERWISE...DIURNAL RANGE OF TEMPERATURES
WITH POSSIBLY SOME NEGATIVE FEEDBACK FROM GREATLY REDUCE SNOW/ICE
FIELDS.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH LOW LEVEL
THERMAL AND MOISTURE FIELDS HANDLED WELL. UPSTREAM INITIALIZATION
SUGGESTS BOTH GFS AND HI-RES ECMWF GOOD AND A ADEQUATE BLEND OF
50/50 MIX OF THESE SOLUTIONS A GOOD STARTING POINT. VERIFICATION
SUGGEST AREAS WITH NO ICE/SNOW COVER HIGHS MAY BE UP TO 3 DEGREES
TOO COLD FOR LATER SHIFTS WHILE AND SNOW/ICE COVERED LOCATIONS COULD
SEE MINS UP TO 3 DEGREES COLDER THAN FORECAST.
SATURDAY NIGHT...ONCE AGAIN HAVE TRIMMED POPS AND SNOW/QPF TOTALS AS
SYSTEM MAY PASS TO OUR SOUTHEAST. LATER SHIFTS MAY BE ABLE TO
REMOVE POPS OVER ALL BUT LOCATIONS SOUTHEAST OF A MACOMB ILLINOIS
TO PRINCETON LINE THAT MAY STILL PICK UP TO AN INCH OF A WET SNOW.
CLEARING SHOULD ARRIVE AFTER 2 AM IN NW AND ENCOMPASS ALL BUT SE 1/3
AREA BY SUNRISE. THIS SHOULD ALLOW FOR MINS AROUND ZERO DEGREES NW
SECTION TO LOWER TEENS IN FAR SOUTHEAST 1/4 WHERE CLOUDS WILL BE
DELAYED TO CLEAR AFTER SUNRISE. LATEST TRENDS SUPPORTS WIND CHILL
VALUES WILL BE MARGINAL MEETING WIND CHILL ADVISORY CRITERIA TO
AROUND -20F FOR 2 TO 5 HOURS OVER NORTHWEST 3 TO 6 COUNTIES FOR
LATER SHIFTS TO ASSESS. NORTHWEST WINDS OF 15 TO 25+ MPH WILL
DIMINISH LATE TO 10 TO 20 MPH BY MORNING.
SUNDAY...CLEAR AND QUITE COLD WITH MODERATE NORTHWEST WINDS
CONTINUING AT 10 TO 20 MPH. HIGHS SHOULD STRUGGLE INTO THE UPPER
SINGLE SINGLE DIGITS NORTHWEST TO THE MID TEENS FAR SOUTHEAST
SECTIONS WITH WIND CHILLS MOSTLY AT OR BELOW ZERO. SUNDAY NIGHT
CLEAR AND COLD WITH LIGHT WESTERLY WINDS LATE KEEPING WIND CHILLS TO
5 TO 15 BELOW ZERO. LOWS SHOULD BE ZERO TO UPPER SINGLE DIGITS WITH
FAVORED LOW LYING LOCATIONS FALLING POSSIBLY BELOW ZERO FOR LATER
SHIFTS TO REASSESS.
MONDAY AND MONDAY NIGHT...PARTLY TO MOSTLY CLOUDY WITH DECENT RISK
OF FLURRIES OR VERY LIGHT SNOW AND NOT AS COLD WITH HIGHS INTO THE
20S AHEAD OF NEXT REINFORCING SHOT OF ARCTIC AIR. MINS 5 TO 15
ABOVE AS NEXT INVASION OF ARCTIC AIR ARRIVES TOWARD MORNING IN THE
NORTHWEST. WIND CHILLS FALLING TO 10 TO 20 BELOW ZERO BY TUESDAY
MORNING.
TUESDAY...CLEAR BLUSTERY AND COLD...SIMILAR TO SUNDAY WITH HIGHS 10
TO 20 ABOVE AND POSSIBLY A FEW DEGREES COLDER THAN THIS AND
NORTHWEST WINDS OF 20 TO 30 MPH AND LOW WIND CHILLS AT OR BELOW
ZERO. TUESDAY NIGHT...MINS ZERO TO 10 ABOVE AND POSSIBLY AT LEAST
3DEGREES COLDER FOR LATER SHIFTS WITH WIND CHILLS ONCE AGAIN TO FALL
TO NEAR 15 TO 20 BELOW NORTH OF I-80.
WEDNESDAY AND THURSDAY...DRY WITH A SLOW WARMING TREND WITH HIGHS
20S WEDNESDAY AND MOSTLY 30S ON THURSDAY. MINS MOSTLY 10 TO 20
ABOVE WEDNESDAY AM AND 20S THURSDAY AM.
FRIDAY...SEASONABLY COLD AND DRY WITH HIGHS NEAR NORMAL OR MID 20S
TO LOWER 30S AND MINS MOSTLY IN THE TEENS. NICHOLS
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 545 PM CST FRI JAN 8 2016
WEAK WINDS AND LOW LEVEL MOISTURE UNDER A SLOW MOVING LOW
PRESSURE SYSTEM WILL KEEP VLIFR TO LIFR CONDITIONS DUE TO DENSE
FOG AND DRIZZLE IN PLACE AT MLI...DBQ AND CID FOR MUCH OF THE
EVENING. IFR CONDITIONS WILL CONTINUE AT BRL. AS THE SYSTEM LIFTS
OUT...WINDS WILL VEER TO THE WEST AND THEN NORTHWEST AND INCREASE
LATE TONIGHT INTO SATURDAY MORNING. THIS WILL BRING IMPROVING
VISIBILITIES...GRADUALLY LIFTING CIGS...AND PRECIPITATION OF A
MORE SCATTERED NATURE IN THE FORM OF DRIZZLE AND RAIN...CHANGING
OVER TO LIGHT SNOW. SCATTERED SNOW SHOWERS WILL BE POSSIBLE
THROUGH SATURDAY WITH GUSTY NORTH TO NORTHWEST WINDS. CIGS AND
VISIBILITIES SHOULD IMPROVE TO IFR IF NOT MVFR THROUGH THE
DAY...BUT FORECAST CONFIDENCE IN THE RATE OF IMPROVEMENT IS LOW.
FOR NOW...WILL REMAIN BIASED TOWARD SLOWER IMPROVEMENT OR MORE
PESSIMISTIC CONDITIONS THROUGHOUT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...DENSE FOG ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BUREAU-CARROLL-
JO DAVIESS-PUTNAM-STEPHENSON-WHITESIDE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...12
SHORT TERM...12
LONG TERM...NICHOLS
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
735 PM CST FRI JAN 8 2016
.UPDATE...
ISSUED AT 735 PM CST FRI JAN 8 2016
AS OF 7 PM...COLDER AIR MOVING INTO THE WEST AND NORTHWEST WAS
BEGINNING TO TRANSITION THE LIGHT PRECIPITATION TO SNOW AND WAS
ALSO CLEARING THE FOG OUT OF THE AREA. HAVE ADJUSTED THE FORECAST
FOR PRECIPITATION TRENDS AND REMOVED THE DENSE FOG ADVISORY ACROSS
OUR FAR WEST AND NW COUNTIES. ALSO CANCELLED THE ADVISORY ACROSS
SE IA AND W CENTRAL IL...WHERE WESTERLY WINDS WRAPPING IN SE OF
THE DEPARTING LOW HAVE LEAD TO VISIBILITIES IMPROVING TO MAINLY
ABOVE ONE MILE.
&&
.SYNOPSIS...
ISSUED AT 344 PM CST FRI JAN 8 2016
LATEST SFC ANALYSIS WAS INDICATING A LOW CENTER MOVING NORTHWARD
ACRS THE WEST CENTRAL DVN CWA ATTM...WITH A ASSOCIATED FRONTAL
SYSTEM TRAILING DOWN INTO SOUTHWESTERN AR AND NORTHERN TX. THE UPPER
LEVEL LOW WAS NOTED ON WATER VAPOR IMAGERY ACRS NORTHEASTERN MO INTO
THE SOUTHERN CWA...WITH A STRONGER WAVE FURTHER UPSTREAM IN A L/W
TROF BASE DIGGING TOWARD WESTERN TX.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
TONIGHT...ASSESSING THE LATEST TRENDS AND LLVL CONVERGENT FLOW
PROPAGATION ASSOCIATED WITH THE PASSING SFC WAVE...HAVE EXTENDED THE
FOG ADVISORY TO 03Z /9 PM CST/ FOR THE WESTERN 2/3S...AND THE
NORTHWESTERN IL COUNTIES NOW INCLUDING THE EASTERN I80 CORRIDOR TIL
06Z /MIDNIGHT CST/. BUT THESE END TIMES MAY BE A BIT GENEROUS AND
THE FOLLOWING SHIFT WILL BE ABLE TO CHOP AWAY FROM THE WEST AND
SOUTH AS THE EVENING PROGRESSES...AS THE LLVL FLOW VEERS TO THE
WEST/NORTHWEST AND INCREASES. LATEST RUN HRRR VSBY PROGS NOW SHIFT
THE 1/4 MILE OR LESS VSBYS EAST OF THE MS RIVER BY 03Z THIS
EVENING.
LINGERING AREAS OF RAIN AND DRIZZLE THIS AFTERNOON AND EARLY EVENING
TO ROLL OFF TO THE NORTHEAST...WITH JUST SPOTTY LIGHTER PRECIP
WRAPPING IN BEHIND THE DEPARTING CYCLONE OUT OF NORTHWESTERN IA.
WITH POST-FRONTAL TOP DOWN COOLING...THIS PRECIP TO CHANGE OVER TO A
LIGHT RAIN/SNOW MIX THEN TO ALL LIGHT WET SNOW OVERNIGHT FROM WEST
TO EAST. LINGERING MILD GROUND TEMPS AND LACK OF PRECIP INTENSITY
SUGGESTS A WET DUSTING TO A TENTH OF AN INCH AT BEST IN AREAS THAT
GET IN ON SOME SNOW LATER TONIGHT. NORTHWEST WINDS TO RAMP UP AFTER
MIDNIGHT TO 15 TO 25 MPH IN INCOMING CANADIAN HIGH PRESSURE GRADIENT
ESPECIALLY ALONG AND WEST OF THE MS RIVER. LLVL COLD CONVEYOR TO
BE WELL IN FLUX ACRS THE AREA BY SAT MORNING.
SATURDAY...12 HR HIGH TEMPS TO OCCUR IN THE MORNING WITH FALLING
TEMPS THRU THE REST OF THE DAY. TIGHT PRESSURE GRADIENT AND STRONG
LLVL COLD AIR ADVECTION TO DIVE BRISK NORTHWEST SFC WINDS OF 15 TO
25+ MPH AND GUSTS WELL OVER 30 MPH AT TIMES. SOME LIGHT SNOW SHOWERS
OR FLURRIES MAY GET WRUNG OUT OF ANY CLOUD DECK WITH ENOUGH
SATURATED DEPTH IN THIS CAA PROCESS ESPECIALLY NORTH OF I80 BUT
LITTLE IF ANY SNOW ACCUM EXPECTED WITH THIS ACTIVITY. THEN ALL EYES
TURN TO THE MAIN SOUTHERN PLAINS LOW PRESSURE WAVE EJECTING
NORTHEASTWARD TOWARD THE MOUTH OF THE OH RIVER VALLEY BY SAT
EVENING. BULK OF THE 12Z RUN MODEL SOLUTIONS HAVE CAUGHT ON TO THE
CURRENT STRONGER SOUTHEASTWARD DIGGING PROCESS OF THE WAVE AIDED
BY UPPER JET PUNCH IN THAT DIRECTION ON IT/S WESTERN FLANK. THUS
THEY HAVE CONTINUED TO TREND FURTHER SOUTHEAST WITH THE MAIN STORM
PROPAGATION PATH. WILL ADJUST SNOW AMOUNTS ON ITS FAR NORTHWESTERN
FLANK OF IT/S DEF ZONE FURTHER DOWN AND EAST AS WELL WITH THE
LATEST THINKING. THIS ONLY PRODUCES UP TO AN INCH OF SNOW BY 00Z
SUNDAY SOUTHEAST OF A LINE GENERALLY FROM SOUTHWEST OF MACOMB
IL...TO PRINCETON IL. FURTHER WEST TOWARD THE MS RIVER MAY ONLY
GET A TENTH OR TWO...AND AREAS WEST OF THE MS RIVER MAY STAY DRY
BESIDES THE LIGHT SNOW/ FLURRIES POSSIBLE NORTH OF I80 GETTING
WRUNG OUT OF WRAP AROUND CLOUD DECK IN THE COLD AIR ADVECTION
PROCESS MENTIONED ABOVE. ANY FURTHER ADJUSTMENT EAST MEANS A NON-
EVENT/MISS FOR THE DVN CWA. ..12..
.LONG TERM...(SATURDAY NIGHT THROUGH NEXT FRIDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
COLD MID JANUARY WEATHER AND DRY TO MOSTLY DRY THROUGH LATE NEXT
WEEK.
LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE
WITH LIMITED SENSIBLE WEATHER ISSUES. MAIN CHALLENGES WILL BE BOUTS
OF FLURRIES AND POSSIBLY VERY LIGHT SNOW ON MONDAY/MONDAY NIGHT AND
AGAIN LATE NEXT WEEK. OTHERWISE...DIURNAL RANGE OF TEMPERATURES
WITH POSSIBLY SOME NEGATIVE FEEDBACK FROM GREATLY REDUCE SNOW/ICE
FIELDS.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH LOW LEVEL
THERMAL AND MOISTURE FIELDS HANDLED WELL. UPSTREAM INITIALIZATION
SUGGESTS BOTH GFS AND HI-RES ECMWF GOOD AND A ADEQUATE BLEND OF
50/50 MIX OF THESE SOLUTIONS A GOOD STARTING POINT. VERIFICATION
SUGGEST AREAS WITH NO ICE/SNOW COVER HIGHS MAY BE UP TO 3 DEGREES
TOO COLD FOR LATER SHIFTS WHILE AND SNOW/ICE COVERED LOCATIONS COULD
SEE MINS UP TO 3 DEGREES COLDER THAN FORECAST.
SATURDAY NIGHT...ONCE AGAIN HAVE TRIMMED POPS AND SNOW/QPF TOTALS AS
SYSTEM MAY PASS TO OUR SOUTHEAST. LATER SHIFTS MAY BE ABLE TO
REMOVE POPS OVER ALL BUT LOCATIONS SOUTHEAST OF A MACOMB ILLINOIS
TO PRINCETON LINE THAT MAY STILL PICK UP TO AN INCH OF A WET SNOW.
CLEARING SHOULD ARRIVE AFTER 2 AM IN NW AND ENCOMPASS ALL BUT SE 1/3
AREA BY SUNRISE. THIS SHOULD ALLOW FOR MINS AROUND ZERO DEGREES NW
SECTION TO LOWER TEENS IN FAR SOUTHEAST 1/4 WHERE CLOUDS WILL BE
DELAYED TO CLEAR AFTER SUNRISE. LATEST TRENDS SUPPORTS WIND CHILL
VALUES WILL BE MARGINAL MEETING WIND CHILL ADVISORY CRITERIA TO
AROUND -20F FOR 2 TO 5 HOURS OVER NORTHWEST 3 TO 6 COUNTIES FOR
LATER SHIFTS TO ASSESS. NORTHWEST WINDS OF 15 TO 25+ MPH WILL
DIMINISH LATE TO 10 TO 20 MPH BY MORNING.
SUNDAY...CLEAR AND QUITE COLD WITH MODERATE NORTHWEST WINDS
CONTINUING AT 10 TO 20 MPH. HIGHS SHOULD STRUGGLE INTO THE UPPER
SINGLE SINGLE DIGITS NORTHWEST TO THE MID TEENS FAR SOUTHEAST
SECTIONS WITH WIND CHILLS MOSTLY AT OR BELOW ZERO. SUNDAY NIGHT
CLEAR AND COLD WITH LIGHT WESTERLY WINDS LATE KEEPING WIND CHILLS TO
5 TO 15 BELOW ZERO. LOWS SHOULD BE ZERO TO UPPER SINGLE DIGITS WITH
FAVORED LOW LYING LOCATIONS FALLING POSSIBLY BELOW ZERO FOR LATER
SHIFTS TO REASSESS.
MONDAY AND MONDAY NIGHT...PARTLY TO MOSTLY CLOUDY WITH DECENT RISK
OF FLURRIES OR VERY LIGHT SNOW AND NOT AS COLD WITH HIGHS INTO THE
20S AHEAD OF NEXT REINFORCING SHOT OF ARCTIC AIR. MINS 5 TO 15
ABOVE AS NEXT INVASION OF ARCTIC AIR ARRIVES TOWARD MORNING IN THE
NORTHWEST. WIND CHILLS FALLING TO 10 TO 20 BELOW ZERO BY TUESDAY
MORNING.
TUESDAY...CLEAR BLUSTERY AND COLD...SIMILAR TO SUNDAY WITH HIGHS 10
TO 20 ABOVE AND POSSIBLY A FEW DEGREES COLDER THAN THIS AND
NORTHWEST WINDS OF 20 TO 30 MPH AND LOW WIND CHILLS AT OR BELOW
ZERO. TUESDAY NIGHT...MINS ZERO TO 10 ABOVE AND POSSIBLY AT LEAST
3DEGREES COLDER FOR LATER SHIFTS WITH WIND CHILLS ONCE AGAIN TO FALL
TO NEAR 15 TO 20 BELOW NORTH OF I-80.
WEDNESDAY AND THURSDAY...DRY WITH A SLOW WARMING TREND WITH HIGHS
20S WEDNESDAY AND MOSTLY 30S ON THURSDAY. MINS MOSTLY 10 TO 20
ABOVE WEDNESDAY AM AND 20S THURSDAY AM.
FRIDAY...SEASONABLY COLD AND DRY WITH HIGHS NEAR NORMAL OR MID 20S
TO LOWER 30S AND MINS MOSTLY IN THE TEENS. NICHOLS
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 545 PM CST FRI JAN 8 2016
WEAK WINDS AND LOW LEVEL MOISTURE UNDER A SLOW MOVING LOW
PRESSURE SYSTEM WILL KEEP VLIFR TO LIFR CONDITIONS DUE TO DENSE
FOG AND DRIZZLE IN PLACE AT MLI...DBQ AND CID FOR MUCH OF THE
EVENING. IFR CONDITIONS WILL CONTINUE AT BRL. AS THE SYSTEM LIFTS
OUT...WINDS WILL VEER TO THE WEST AND THEN NORTHWEST AND INCREASE
LATE TONIGHT INTO SATURDAY MORNING. THIS WILL BRING IMPROVING
VISIBILITIES...GRADUALLY LIFTING CIGS...AND PRECIPITATION OF A
MORE SCATTERED NATURE IN THE FORM OF DRIZZLE AND RAIN...CHANGING
OVER TO LIGHT SNOW. SCATTERED SNOW SHOWERS WILL BE POSSIBLE
THROUGH SATURDAY WITH GUSTY NORTH TO NORTHWEST WINDS. CIGS AND
VISIBILITIES SHOULD IMPROVE TO IFR IF NOT MVFR THROUGH THE
DAY...BUT FORECAST CONFIDENCE IN THE RATE OF IMPROVEMENT IS LOW.
FOR NOW...WILL REMAIN BIASED TOWARD SLOWER IMPROVEMENT OR MORE
PESSIMISTIC CONDITIONS THROUGHOUT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 9 PM CST THIS EVENING FOR CEDAR-CLINTON-
DUBUQUE-JACKSON-JOHNSON-JONES-LINN-LOUISA-MUSCATINE-SCOTT-
WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL 9 PM CST THIS EVENING FOR HENRY IL-
MERCER-ROCK ISLAND.
DENSE FOG ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BUREAU-CARROLL-
JO DAVIESS-PUTNAM-STEPHENSON-WHITESIDE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...12
SHORT TERM...12
LONG TERM...NICHOLS
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
545 PM CST FRI JAN 8 2016
...AVIATION UPDATE...
.SYNOPSIS...
ISSUED AT 344 PM CST FRI JAN 8 2016
LATEST SFC ANALYSIS WAS INDICATING A LOW CENTER MOVING NORTHWARD
ACRS THE WEST CENTRAL DVN CWA ATTM...WITH A ASSOCIATED FRONTAL
SYSTEM TRAILING DOWN INTO SOUTHWESTERN AR AND NORTHERN TX. THE UPPER
LEVEL LOW WAS NOTED ON WATER VAPOR IMAGERY ACRS NORTHEASTERN MO INTO
THE SOUTHERN CWA...WITH A STRONGER WAVE FURTHER UPSTREAM IN A L/W
TROF BASE DIGGING TOWARD WESTERN TX.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
TONIGHT...ASSESSING THE LATEST TRENDS AND LLVL CONVERGENT FLOW
PROPAGATION ASSOCIATED WITH THE PASSING SFC WAVE...HAVE EXTENDED THE
FOG ADVISORY TO 03Z /9 PM CST/ FOR THE WESTERN 2/3S...AND THE
NORTHWESTERN IL COUNTIES NOW INCLUDING THE EASTERN I80 CORRIDOR TIL
06Z /MIDNIGHT CST/. BUT THESE END TIMES MAY BE A BIT GENEROUS AND
THE FOLLOWING SHIFT WILL BE ABLE TO CHOP AWAY FROM THE WEST AND
SOUTH AS THE EVENING PROGRESSES...AS THE LLVL FLOW VEERS TO THE
WEST/NORTHWEST AND INCREASES. LATEST RUN HRRR VSBY PROGS NOW SHIFT
THE 1/4 MILE OR LESS VSBYS EAST OF THE MS RIVER BY 03Z THIS
EVENING.
LINGERING AREAS OF RAIN AND DRIZZLE THIS AFTERNOON AND EARLY EVENING
TO ROLL OFF TO THE NORTHEAST...WITH JUST SPOTTY LIGHTER PRECIP
WRAPPING IN BEHIND THE DEPARTING CYCLONE OUT OF NORTHWESTERN IA.
WITH POST-FRONTAL TOP DOWN COOLING...THIS PRECIP TO CHANGE OVER TO A
LIGHT RAIN/SNOW MIX THEN TO ALL LIGHT WET SNOW OVERNIGHT FROM WEST
TO EAST. LINGERING MILD GROUND TEMPS AND LACK OF PRECIP INTENSITY
SUGGESTS A WET DUSTING TO A TENTH OF AN INCH AT BEST IN AREAS THAT
GET IN ON SOME SNOW LATER TONIGHT. NORTHWEST WINDS TO RAMP UP AFTER
MIDNIGHT TO 15 TO 25 MPH IN INCOMING CANADIAN HIGH PRESSURE GRADIENT
ESPECIALLY ALONG AND WEST OF THE MS RIVER. LLVL COLD CONVEYOR TO
BE WELL IN FLUX ACRS THE AREA BY SAT MORNING.
SATURDAY...12 HR HIGH TEMPS TO OCCUR IN THE MORNING WITH FALLING
TEMPS THRU THE REST OF THE DAY. TIGHT PRESSURE GRADIENT AND STRONG
LLVL COLD AIR ADVECTION TO DIVE BRISK NORTHWEST SFC WINDS OF 15 TO
25+ MPH AND GUSTS WELL OVER 30 MPH AT TIMES. SOME LIGHT SNOW SHOWERS
OR FLURRIES MAY GET WRUNG OUT OF ANY CLOUD DECK WITH ENOUGH
SATURATED DEPTH IN THIS CAA PROCESS ESPECIALLY NORTH OF I80 BUT
LITTLE IF ANY SNOW ACCUM EXPECTED WITH THIS ACTIVITY. THEN ALL EYES
TURN TO THE MAIN SOUTHERN PLAINS LOW PRESSURE WAVE EJECTING
NORTHEASTWARD TOWARD THE MOUTH OF THE OH RIVER VALLEY BY SAT
EVENING. BULK OF THE 12Z RUN MODEL SOLUTIONS HAVE CAUGHT ON TO THE
CURRENT STRONGER SOUTHEASTWARD DIGGING PROCESS OF THE WAVE AIDED
BY UPPER JET PUNCH IN THAT DIRECTION ON IT/S WESTERN FLANK. THUS
THEY HAVE CONTINUED TO TREND FURTHER SOUTHEAST WITH THE MAIN STORM
PROPAGATION PATH. WILL ADJUST SNOW AMOUNTS ON ITS FAR NORTHWESTERN
FLANK OF IT/S DEF ZONE FURTHER DOWN AND EAST AS WELL WITH THE
LATEST THINKING. THIS ONLY PRODUCES UP TO AN INCH OF SNOW BY 00Z
SUNDAY SOUTHEAST OF A LINE GENERALLY FROM SOUTHWEST OF MACOMB
IL...TO PRINCETON IL. FURTHER WEST TOWARD THE MS RIVER MAY ONLY
GET A TENTH OR TWO...AND AREAS WEST OF THE MS RIVER MAY STAY DRY
BESIDES THE LIGHT SNOW/ FLURRIES POSSIBLE NORTH OF I80 GETTING
WRUNG OUT OF WRAP AROUND CLOUD DECK IN THE COLD AIR ADVECTION
PROCESS MENTIONED ABOVE. ANY FURTHER ADJUSTMENT EAST MEANS A NON-
EVENT/MISS FOR THE DVN CWA. ..12..
.LONG TERM...(SATURDAY NIGHT THROUGH NEXT FRIDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
COLD MID JANUARY WEATHER AND DRY TO MOSTLY DRY THROUGH LATE NEXT
WEEK.
LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE
WITH LIMITED SENSIBLE WEATHER ISSUES. MAIN CHALLENGES WILL BE BOUTS
OF FLURRIES AND POSSIBLY VERY LIGHT SNOW ON MONDAY/MONDAY NIGHT AND
AGAIN LATE NEXT WEEK. OTHERWISE...DIURNAL RANGE OF TEMPERATURES
WITH POSSIBLY SOME NEGATIVE FEEDBACK FROM GREATLY REDUCE SNOW/ICE
FIELDS.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH LOW LEVEL
THERMAL AND MOISTURE FIELDS HANDLED WELL. UPSTREAM INITIALIZATION
SUGGESTS BOTH GFS AND HI-RES ECMWF GOOD AND A ADEQUATE BLEND OF
50/50 MIX OF THESE SOLUTIONS A GOOD STARTING POINT. VERIFICATION
SUGGEST AREAS WITH NO ICE/SNOW COVER HIGHS MAY BE UP TO 3 DEGREES
TOO COLD FOR LATER SHIFTS WHILE AND SNOW/ICE COVERED LOCATIONS COULD
SEE MINS UP TO 3 DEGREES COLDER THAN FORECAST.
SATURDAY NIGHT...ONCE AGAIN HAVE TRIMMED POPS AND SNOW/QPF TOTALS AS
SYSTEM MAY PASS TO OUR SOUTHEAST. LATER SHIFTS MAY BE ABLE TO
REMOVE POPS OVER ALL BUT LOCATIONS SOUTHEAST OF A MACOMB ILLINOIS
TO PRINCETON LINE THAT MAY STILL PICK UP TO AN INCH OF A WET SNOW.
CLEARING SHOULD ARRIVE AFTER 2 AM IN NW AND ENCOMPASS ALL BUT SE 1/3
AREA BY SUNRISE. THIS SHOULD ALLOW FOR MINS AROUND ZERO DEGREES NW
SECTION TO LOWER TEENS IN FAR SOUTHEAST 1/4 WHERE CLOUDS WILL BE
DELAYED TO CLEAR AFTER SUNRISE. LATEST TRENDS SUPPORTS WIND CHILL
VALUES WILL BE MARGINAL MEETING WIND CHILL ADVISORY CRITERIA TO
AROUND -20F FOR 2 TO 5 HOURS OVER NORTHWEST 3 TO 6 COUNTIES FOR
LATER SHIFTS TO ASSESS. NORTHWEST WINDS OF 15 TO 25+ MPH WILL
DIMINISH LATE TO 10 TO 20 MPH BY MORNING.
SUNDAY...CLEAR AND QUITE COLD WITH MODERATE NORTHWEST WINDS
CONTINUING AT 10 TO 20 MPH. HIGHS SHOULD STRUGGLE INTO THE UPPER
SINGLE SINGLE DIGITS NORTHWEST TO THE MID TEENS FAR SOUTHEAST
SECTIONS WITH WIND CHILLS MOSTLY AT OR BELOW ZERO. SUNDAY NIGHT
CLEAR AND COLD WITH LIGHT WESTERLY WINDS LATE KEEPING WIND CHILLS TO
5 TO 15 BELOW ZERO. LOWS SHOULD BE ZERO TO UPPER SINGLE DIGITS WITH
FAVORED LOW LYING LOCATIONS FALLING POSSIBLY BELOW ZERO FOR LATER
SHIFTS TO REASSESS.
MONDAY AND MONDAY NIGHT...PARTLY TO MOSTLY CLOUDY WITH DECENT RISK
OF FLURRIES OR VERY LIGHT SNOW AND NOT AS COLD WITH HIGHS INTO THE
20S AHEAD OF NEXT REINFORCING SHOT OF ARCTIC AIR. MINS 5 TO 15
ABOVE AS NEXT INVASION OF ARCTIC AIR ARRIVES TOWARD MORNING IN THE
NORTHWEST. WIND CHILLS FALLING TO 10 TO 20 BELOW ZERO BY TUESDAY
MORNING.
TUESDAY...CLEAR BLUSTERY AND COLD...SIMILAR TO SUNDAY WITH HIGHS 10
TO 20 ABOVE AND POSSIBLY A FEW DEGREES COLDER THAN THIS AND
NORTHWEST WINDS OF 20 TO 30 MPH AND LOW WIND CHILLS AT OR BELOW
ZERO. TUESDAY NIGHT...MINS ZERO TO 10 ABOVE AND POSSIBLY AT LEAST
3DEGREES COLDER FOR LATER SHIFTS WITH WIND CHILLS ONCE AGAIN TO FALL
TO NEAR 15 TO 20 BELOW NORTH OF I-80.
WEDNESDAY AND THURSDAY...DRY WITH A SLOW WARMING TREND WITH HIGHS
20S WEDNESDAY AND MOSTLY 30S ON THURSDAY. MINS MOSTLY 10 TO 20
ABOVE WEDNESDAY AM AND 20S THURSDAY AM.
FRIDAY...SEASONABLY COLD AND DRY WITH HIGHS NEAR NORMAL OR MID 20S
TO LOWER 30S AND MINS MOSTLY IN THE TEENS. NICHOLS
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 545 PM CST FRI JAN 8 2016
WEAK WINDS AND LOW LEVEL MOISTURE UNDER A SLOW MOVING LOW
PRESSURE SYSTEM WILL KEEP VLIFR TO LIFR CONDITIONS DUE TO DENSE
FOG AND DRIZZLE IN PLACE AT MLI...DBQ AND CID FOR MUCH OF THE
EVENING. IFR CONDITIONS WILL CONTINUE AT BRL. AS THE SYSTEM LIFTS
OUT...WINDS WILL VEER TO THE WEST AND THEN NORTHWEST AND INCREASE
LATE TONIGHT INTO SATURDAY MORNING. THIS WILL BRING IMPROVING
VISIBILITIES...GRADUALLY LIFTING CIGS...AND PRECIPITATION OF A
MORE SCATTERED NATURE IN THE FORM OF DRIZZLE AND RAIN...CHANGING
OVER TO LIGHT SNOW. SCATTERED SNOW SHOWERS WILL BE POSSIBLE
THROUGH SATURDAY WITH GUSTY NORTH TO NORTHWEST WINDS. CIGS AND
VISIBILITIES SHOULD IMPROVE TO IFR IF NOT MVFR THROUGH THE
DAY...BUT FORECAST CONFIDENCE IN THE RATE OF IMPROVEMENT IS LOW.
FOR NOW...WILL REMAIN BIASED TOWARD SLOWER IMPROVEMENT OR MORE
PESSIMISTIC CONDITIONS THROUGHOUT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 9 PM CST THIS EVENING FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LINN-LOUISA-
MUSCATINE-SCOTT-WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL 9 PM CST THIS EVENING FOR HENDERSON-
HENRY IL-MERCER-ROCK ISLAND-WARREN.
DENSE FOG ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BUREAU-CARROLL-
JO DAVIESS-PUTNAM-STEPHENSON-WHITESIDE.
MO...NONE.
&&
$$
SYNOPSIS...12
SHORT TERM...12
LONG TERM...NICHOLS
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1142 PM CST WED JAN 6 2016
...AVIATION UPDATE...
.UPDATE...
ISSUED AT 814 PM CST WED JAN 6 2016
LATEST WATER VAPOR IMAGERY SHOWS THE SHORTWAVE TROUGH AXIS MOVING
THROUGH CENTRAL IA...WITH AREA RADARS SHOWING ASSOCIATED
PRECIPITATION OVER CENTRAL INTO EAST CENTRAL IA. BASED ON SURFACE
OBSERVATIONS...THE PRECIPITATION IS MAINLY SNOW NW OF A DSM TO ALO
LINE...WITH LIGHT RAIN OR DRIZZLE TO THE SOUTHEAST WHERE SURFACE
TEMPERATURES WERE ABOVE 32. AN AREA OF ENHANCED REFLECTIVITY MOVING
ALONG THE I-80 AXIS WEST OF IOWA CITY INDICATES POSSIBLE SLEET
OCCURRING...SUPPORTED BY A SHALLOW SUB FREEZING LAYER ON KDVN
SOUNDING AROUND 500 TO 1500 FT AGL.
THE BULK OF THE PRECIPITATION APPEARS TO BE ON TRACK TO REMAIN
MAINLY NORTH OF I-80 AHEAD OF THE PASSING SHORTWAVE AND HAVE
UPDATED THE FORECAST TO SIMPLIFY TO A SNOW/SLEET MIX EARLY...THEN
LIGHT SNOW CHANGING TO LIGHT RAIN OVERNIGHT AS WARM ADVECTION SW
FLOW WARMS THE ENTIRE SUB 850 MB LAYER ABOVE FREEZING FROM SOUTH
TO NORTH OVERNIGHT TO NEAR THE HIGHWAY 20 CORRIDOR BY SUNRISE.
WITH UPSTREAM REPORTS SHOWING RATES AROUND .01 TO .02 PER HOUR AND
LIFT RAPIDLY SPREADING NORTHEAST...OVERNIGHT QPF SHOULD BE LESS
THAN A TENTH OF AN INCH WITH NEGLIGIBLE SNOWFALL. TO THE SOUTH
AND SE...LIFT IS WEAKER AND PRIMARILY DUE TO WARM/MOIST ADVECTION
ALOFT. ANY PRECIPITATION WILL HAVE TO OVERCOME DRY AIR IN THE LOW
LEVELS AND WILL ANTICIPATE PATCHY LIGHT LIGHT RAIN OR DRIZZLE
THROUGH THE REST OF THE NIGHT WITH NEAR STEADY TEMPERATURES AND
PAVEMENT TEMPERATURES HOLDING ABOVE FREEZING.
&&
.SYNOPSIS...
ISSUED AT 322 PM CST WED JAN 6 2016
HIGH PRESSURE WAS LOCATED ACROSS THE EASTERN SEABOARD AS A
DEVELOPING SURFACE LOW TOOK SHAPE ACROSS THE LEE OF THE ROCKIES. S
FLOW AT THE SFC A LONG WITH A SHORTWAVE ALOFT AIDED IN BRINGING
IN WARMER AND MORE MOIST AIR INTO THE REGION THIS AFTERNOON.
PRECIP ASSOCIATED WITH THIS INITIAL WAVE STRUGGLED TO REACH THE
GROUND AS DRY AIR WAS IN PLACE. THIS WILL CHANGE WITH THE
ADVECTION OF WARMER AIR...DEEPER MOISTURE AND ANOTHER WAVE AFFECTS
THE AREA THROUGH THE SHORT TERM.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 322 PM CST WED JAN 6 2016
MAIN FORECAST CONCERN IN THE SHORT TERM ARE THE THERMODYNAMICS AND
THE ASSOCIATED PRECIP TYPES WITH THEM. THERMAL PROFILES HOVER
AROUND FREEZING FROM THE SFC TO ALOFT...THIS IS LEADING TO A
TRICKY FORECAST ACROSS THE AREA. REGARDLESS...THE AREA IS EXPECTED
TO SEE MEASURABLE PRECIP THROUGH THE SHORT TERM....WITH MOST
LIQUID QPF VALUES LESS THAN 0.25 INCHES..EXCEPT FOR THE MO
COUNTIES THAT MAY SEE UNDER 0.5 INCHES.
FORECAST CHALLENGES ABOUND WITH DIFFICULT PTYPE FORECAST AND
POSSIBLE IMPACTS. GRIDDED AND SPECTRAL SYNOPTIC SCALE MODELS
SUGGEST THAT THE AREA WILL STAY COOLER LONGER...LEADING TO MORE OF
A MIX OF FZRA...RA..AND SN ACROSS THE AREA. WHEREAS THE RUC AND
OTHER CAMS ARE MORE INDICATIVE OF A QUICK CHANGE TO RAIN FROM
SNOW. THIS IS AT ODDS WITH THE TRADITIONAL WARM FRONT MODEL WITH
WARMING ALOFT THAT WOULD LEAD TO MIXED PRECIP. WOULD BE MORE
CONFIDENT IN A SOLUTION IF I SAW THE DEWPOINTS RISING AS WELL WITH
THE SFC TEMPS. CONCERNED THAT EVAPORATIVE COOLING COULD LEAD TO A
LARGER AREA OF FZRA...MORE LIKE THE SYNOPTIC SCALE MODELS.
AT THIS TIME WILL GO WITH A MIX MAINLY NORTH OF HWY 30 TONIGHT.
CLOSER TO 12Z AN AREA OF FZRA COULD FORM NEAR I80 BEFORE A
CHANGEOVER TO ALL RAIN. THERE COULD BE TRAVEL ISSUES EARLY IN THE
AM BEFORE THE FZRA SWITCHES OVER TO ALL RA IN THE MID AM. NORTH OF
HIGHWAY 30 COULD SEE SOME SLEET AND FZRA IN THE AM...THIS COULD
LEAD TO SOME TRAVEL ISSUES ACROSS THE NORTHERN ZONES. THE PLUS TO
THIS IS THAT WHATEVER FALLS OVERNIGHT AND TOMORROW AM WILL MELT
WITH THE RA IN THE AFTERNOON TOMORROW. OVERALL QPF AMOUNTS ARE
LOW...BUT WITH THE LIGHT RAIN RATES..THINK THAT A THIN GLAZE OF
ICE COULD COAT SOME ELEVATE OBJECTS AND POSSIBLY UNTREATED
ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES.
IT WILL BE IMPORTANT TO WATCH THE TEMPS AND DEWPOINTS TONIGHT.
THIS WILL HELP TO DETERMINE WHETHER OR NOT MORE FREEZING RAIN OR
RAIN WILL FALL.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 322 PM CST WED JAN 6 2016
THURSDAY NIGHT AND FRIDAY...PERIODS OF LIGHT RAIN ARE LIKELY OVER
EASTERN IOWA/WESTERN ILLINOIS/AND NORTHEAST MISSOURI. THE FIRST WAVE
SHOULD BE ONGOING FRIDAY EVENING...LASTING INTO THE FIRST HALF OF
THE NIGHT. TIME-HEIGHT SECTIONS SUGGEST THIS ROUND TO BE DRIVEN
MAINLY BY WARM AIR ADVECTION BETWEEN 850-700MB. SFC TEMPS SHOULD
HOLD STEADY OVERNIGHT THURSDAY IN THE SE SFC FLOW. EXPECTING LOWS IN
THE 33-34 F RANGE ACROSS THE NORTH ALONG HIGHWAY 20...MID 30S ALONG
I-80...AND MID TO UPPER 30S SOUTH OF HIGHWAY 34.
THEN AS THE WEAK 1005MB SFC LOW PULLS NORTHEASTWARD ACROSS E IOWA ON
FRIDAY WINDS ARE FORECAST TO VEER TO A MORE SOUTHERLY DIRECTION
THEREBY PULLING THE THERMAL RIDGE/THETA-E GRADIENT NORTHWARD INTO THE
DVN CWA. HAVE UPPER 40S IN THE FAR SOUTH...LOWER 40S NEAR THE QUAD
CITIES AND MID 30S FAR NORTH FOR HIGHS. THE 500MB VORTICITY MAX AND
ATTENDANT DCVA WILL CROSS THE REGION DURING THE DAY BRINGING A
SECONDARY WAVE OF LIGHT RAIN. A VERY LOW OVERCAST IS LIKELY AND
PERIODS OF DRIZZLE ARE POSSIBLE BASED ON THE SATURATED FORECAST
SOUNDINGS.
SATURDAY...A COMPACT SHORTWAVE IS FORECAST TO RIDE THE SW-TO-NE
ORIENTED 850MB BAROCLINIC ZONE THAT WILL BE DRAPED ACROSS THE
CENTRAL U.S. INTO THE WESTERN GREAT LAKES. MODELS VARY CONSIDERABLY
ON THE TRACK/STRENGTH OF THIS LOW BUT THERE IS THE POTENTIAL FOR
ACCUMULATING SNOW IN A PORTION OF THE DVN CWA.
AT THIS TIME...THE BETTER CHANCES FOR THE STEADIEST PRECIP ARE
ACROSS THE EASTERN CWA OR EAST OF THE MISSISSIPPI RIVER. PLENTY OF
TIME FOR THE MODELS TO ADJUST THE EVOLUTION OF THIS
SYSTEM...THEREFORE SHIFTS TO THE NW OR EVEN THE EAST REMAIN
POSSIBLE...CANNOT GET INTO MUCH OF THE DETAILS WITH THIS MUCH MODEL
UNCERTAINTY. WHAT IS MORE OF A SURE THING THIS FAR OUT IS GUSTY
NORTHWEST WINDS...POSSIBLY IN EXCESS OF 30 MPH. FOR AREAS THAT DO
RECEIVE SNOW...THE WINDS WOULD RESULT IN A HEIGHTENED TRAVEL IMPACT.
PLEASE STAY TUNED TO THE LATEST FORECASTS OVER THE NEXT FEW DAYS.
SUNDAY...ARCTIC AIR POISED TO DUMP INTO THE MIDWEST. CONSENSUS HIGHS
RANGE FROM NEAR 5 F BY INDEPENDENCE IOWA TO AROUND 12 F IN THE QUAD
CITIES...TO THE MID TEEN BY MACOMB ILLINOIS. 850MB TEMPS ARE
PROJECTED TO BOTTOM OUT NEAR -16 C TO -18 C AND 1000-500MB
THICKNESSES TO AN IMPRESSIVELY LOW 504 DAM ON THE ECMWF AND 510 DAM
ON THE GFS.
SUNDAY NIGHT...TEMPS ARE HIGHLY CONTINGENT ON HOW MUCH SNOW IS ON
THE GROUND OR IF THERE IS ANY. CURRENT MODEL CONSENSUS FORECAST HAS
SINGLE DIGITS LOWS ABOVE AND BELOW ZERO.
WIND CHILLS...LOOK TO BE COLDEST SUNDAY NIGHT AND MONDAY MORNING.
ADVISORY LEVEL VALUES NEAR -20 F ARE POSSIBLE...ESPECIALLY ALONG AND
NORTH OF HIGHWAY 30.
MONDAY AND TUESDAY...DAYTIME HIGHS SHOULD MODERATE A BIT INTO THE
TEENS MONDAY WITH TEENS/20S ON TUESDAY PER MODEL CONSENSUS.
OVERNIGHT LOWS SHOULD REMAIN ON THE COLD SIDE...IN THE SINGLE DIGITS
AND TEENS. CONFIDENCE FOR THE TEMP FORECAST ON TUESDAY IS LOW WITH
THE GFS AND ECMWF SHOWING DIFFERENT TEMP ADVECTION PATTERNS.
A CLIPPER TYPE SYSTEM MAY BRING SOME SNOW SHOWERS TO THE WESTERN
GREAT LAKES AREA ON TUESDAY...BUT ONLY HAVE SLIGHT CHANCES OVER THE
NE SECTION OF THE DVN CWA AS MODELS ARE NOT SHOWING MUCH IN THE WAY
OF MOISTURE RIGHT NOW. UTTECH
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CST WED JAN 6 2016
LIGHT PRECIPITATION WILL CONTINUE ACROSS THE AREA OVERNIGHT
THROUGH THURSDAY WITH LOWERING CIGS AND VISIBILITIES LEADING TO
PREVAILING IFR CONDITIONS BY SUNRISE. A MIX OF RAIN AND SNOW WILL
AFFECT THE DBQ TERMINAL AFTER MIDNIGHT INTO EARLY THURSDAY
MORNING...WITH THE REMAINDER OF THE TERMINALS PREDOMINANTLY LIGHT
RAIN OR DRIZZLE WITH FOG ALSO DEVELOPING. THERE IS A LOW
POTENTIAL FOR LIGHT ICE ACCUMULATION IN THE PREDAWN HOURS AT DBQ
BEFORE TEMPERATURES RISE ABOVE FREEZING. THURSDAY...IFR AND
POSSIBLY LIFR CONDITIONS ARE EXPECTED WITH DRIZZLE GIVING WAY TO
ANOTHER ROUND OF RAIN BY EVENING FROM SOUTH TO NORTH WITH THE
NEXT UPPER LEVEL SYSTEM.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...UTTECH
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1212 AM CST THU JAN 7 2016
.AVIATION...
FOR THE ARKLATEX...NUMEROUS SHWRS STRETCH FROM KTXK...TO KSHV...TO
KJAS AND STILL WITH A BACK EDGE ON APPROACH TO KTYR TO KLFK ATTM.
THE MAIN UPPER LOW IS OVER N TX/NM AND ARCS A BAND OF RA SHOWERS
OFF THE COASTAL BEND AND IS MOVING NE AT 30KTS. THIS HEAVIER
PRECIP WILL CRASH CIGS/VSBY OVERNIGHT FOR ALL TERMINALS AND FOR
MUCH OF THURS IN IT/S WAKE WITH NO FROPA AND SE WINDS 5-10KTS.
ALOFT...WE ARE SE TO 5KFT...THEN KEEP SW/W ON UP 30-60KTS. WE MAY
SEE SOME MVFR LATE...BUT DENSE FOG LIKELY EARLY FRIDAY. /24/
&&
.PREV DISCUSSION... /ISSUED 1008 PM CST WED JAN 6 2016/
DISCUSSION...
THE EVENING WATER VAPOR IMAGERY INDICATES A DISCERNABLE SHORTWAVE
TRANSLATING E ACROSS THE ERN TX PANDHANDLE SE INTO CNTRL TX...WITH
AN AREA OF DEEPENING CONVECTION CONTINUING TO EXPAND ENE INTO E
TX. THE EXTENT OF LIGHTNING HAS DIMINISHED OVER THE LAST COUPLE
OF HOURS OVER CNTRL TX...BUT COOLING CLOUD TOPS AND 700-500MB LAPSE
RATES BETWEEN 6-6.5C/KM MAY STILL YIELD ISOLATED STRIKES WITHIN
THE EMBEDDED CONVECTION. THE AIR MASS STILL HAS A WAYS TO MOISTEN
ACROSS NCNTRL/NE LA...AS THE ISOLATED -SHRA THAT HAS DEVELOPED
ALONG AN EWD EXPANDING H850 THETA-E AXIS HAS YET TO BE SUFFICIENT
IN MOISTENING THE COLUMN. HOWEVER...THAT WILL CHANGE LATE TONIGHT
AS THE MORE ORGANIZED CONVECTION SPREADS E AND SATURATES THE
COLUMN FROM THE TOP DOWN.
HAVE UPDATED THE ZONES TO BEEF UP POPS AREAWIDE LATE TONIGHT TO
HIGH END CATEGORICAL...WITH LOW END CATEGORICAL FOR THE ERN
PARISHES OF NCNTRL LA. HAVE ALSO ADJUSTED POPS SLIGHTLY THURSDAY
MORNING BASED ON THE RECENT RUNS OF THE HRRR AND 00Z NAM...WHICH
MAINTAIN THE ORGANIZED CONVECTION OVER THE ERN ZONES THROUGH MID
MORNING BEFORE DIMINISHING FROM W TO E AS DRY SLOTTING ALOFT
SPREADS ENE IN WAKE OF THE SHORTWAVE TROUGH PASSAGE. ALSO ADJUSTED
SKY COVER TO MOSTLY CLOUDY FOR THE AFTERNOON OVER E TX...AS THE LOW
CLOUDS MAY BE STUBBORN TO COMPLETELY SCATTER OUT UNTIL LATE IN THE
DAY. ALSO MADE A FEW MINOR ADJUSTMENTS TO MIN TEMPS TONIGHT...WITH
READINGS LIKELY REMAINING STEADY OR EVEN SLOWLY RISING OVERNIGHT
AS THE RAIN BRINGS SLIGHTLY WARMER TEMPS ALOFT DOWN TO THE SFC.
OTHERWISE...THE REMAINDER OF THE FORECAST IS IN GOOD SHAPE. ZONE
UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 48 70 47 56 / 10 30 50 20
MLU 50 70 50 62 / 10 10 50 30
DEQ 41 65 42 51 / 10 20 30 20
TXK 47 67 45 53 / 10 30 40 20
ELD 47 67 46 58 / 10 20 50 30
TYR 47 69 44 52 / 10 40 30 10
GGG 46 69 45 54 / 10 40 40 10
LFK 48 69 48 58 / 10 40 50 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24/15/12
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1008 PM CST WED JAN 6 2016
.DISCUSSION...
THE EVENING WATER VAPOR IMAGERY INDICATES A DISCERNABLE SHORTWAVE
TRANSLATING E ACROSS THE ERN TX PANDHANDLE SE INTO CNTRL TX...WITH
AN AREA OF DEEPENING CONVECTION CONTINUING TO EXPAND ENE INTO E
TX. THE EXTENT OF LIGHTNING HAS DIMINISHED OVER THE LAST COUPLE
OF HOURS OVER CNTRL TX...BUT COOLING CLOUD TOPS AND 700-500MB LAPSE
RATES BETWEEN 6-6.5C/KM MAY STILL YIELD ISOLATED STRIKES WITHIN
THE EMBEDDED CONVECTION. THE AIR MASS STILL HAS A WAYS TO MOISTEN
ACROSS NCNTRL/NE LA...AS THE ISOLATED -SHRA THAT HAS DEVELOPED
ALONG AN EWD EXPANDING H850 THETA-E AXIS HAS YET TO BE SUFFICIENT
IN MOISTENING THE COLUMN. HOWEVER...THAT WILL CHANGE LATE TONIGHT
AS THE MORE ORGANIZED CONVECTION SPREADS E AND SATURATES THE
COLUMN FROM THE TOP DOWN.
HAVE UPDATED THE ZONES TO BEEF UP POPS AREAWIDE LATE TONIGHT TO
HIGH END CATEGORICAL...WITH LOW END CATEGORICAL FOR THE ERN
PARISHES OF NCNTRL LA. HAVE ALSO ADJUSTED POPS SLIGHTLY THURSDAY
MORNING BASED ON THE RECENT RUNS OF THE HRRR AND 00Z NAM...WHICH
MAINTAIN THE ORGANIZED CONVECTION OVER THE ERN ZONES THROUGH MID
MORNING BEFORE DIMINISHING FROM W TO E AS DRY SLOTTING ALOFT
SPREADS ENE IN WAKE OF THE SHORTWAVE TROUGH PASSAGE. ALSO ADJUSTED
SKY COVER TO MOSTLY CLOUDY FOR THE AFTERNOON OVER E TX...AS THE LOW
CLOUDS MAY BE STUBBORN TO COMPLETELY SCATTER OUT UNTIL LATE IN THE
DAY. ALSO MADE A FEW MINOR ADJUSTMENTS TO MIN TEMPS TONIGHT...WITH
READINGS LIKELY REMAINING STEADY OR EVEN SLOWLY RISING OVERNIGHT
AS THE RAIN BRINGS SLIGHTLY WARMER TEMPS ALOFT DOWN TO THE SFC.
OTHERWISE...THE REMAINDER OF THE FORECAST IS IN GOOD SHAPE. ZONE
UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PREV DISCUSSION... /ISSUED 624 PM CST WED JAN 6 2016/
AVIATION...
FOR THE ARKLATEX...VFR HOLDING FOR NOW WITH LIGHT SHOWERS AREA
WIDE NOT AFFECTING VSBY JUST YET. THIS IS A LEAD SHORT WAVE MOVING
OVERHEAD. THE MAIN UPPER LOW IS OVER W TX/NM ATTN AND IS ON
APPROACH WITH TSTMS OVER THE TX COASTAL BEND MOVING TOWARD KLFK AND
PUSHING OUT OF THE HILL COUNTRY FOR I-20 TERMINALS MID TO LATE
EVENING. THIS HEAVIER PRECIP WILL CRASH CIGS/VSBY OVERNIGHT AND
FOR ALL OF THURS IN IT/S WAKE WITH NO FROPA AND SE WINDS 5-10KTS.
WE MAY SEE SOME MVFR LATE...BUT DENSE FOG LIKELY EARLY FRIDAY.
/24/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 51 63 48 70 / 100 50 10 30
MLU 47 58 50 70 / 80 90 10 10
DEQ 44 57 41 65 / 100 60 10 20
TXK 46 58 47 67 / 100 50 10 30
ELD 47 56 47 67 / 90 90 10 20
TYR 49 65 47 69 / 100 20 10 40
GGG 49 65 46 69 / 100 30 10 40
LFK 52 67 48 69 / 100 20 10 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS DULUTH MN
1137 PM CST WED JAN 6 2016
.UPDATE...
ISSUED AT 932 PM CST WED JAN 6 2016
SNOW WAS FALLING OVER MUCH OF NORTHWEST WISCONSIN AND WAS
INCREASING OVER NORTHERN MINNESOTA AS WELL. A NARROW BAND OF
HEAVIER SNOW DEVELOPED OVER THE TWIN PORTS INTO EXTREME NORTHERN
WISCONSIN THIS EVENING AND IT DUMPED A QUICK HALF TO ONE INCH OF
SNOW. WE HAVE INCREASED SNOWFALL OVER MUCH OF THE AREA
TONIGHT...BUT STILL HAVE MOST AREAS FROM 1 TO 2 INCHES BY MORNING.
THE 00Z NAM FORECASTS MORE SNOWFALL OVER FAR NORTHERN MINNESOTA
AFTER 06Z...AND WE ARE SEEING A NARROW BAND FORMING BETWEEN
BIGFORK AND ELY AS OF 930 PM. POPS WERE INCREASED TONIGHT INTO
THURSDAY MORNING AND WE BUMPED UP SNOWFALL FURTHER.
CALLS TO LEC/S IN OUR SOUTHWEST CWA REVEALED FEW FREEZING DRIZZLE
REPORTS AND THE LATEST RAP SHOWED SATURATION OCCURRING AROUND OR
SHORTLY AFTER 04Z RESULTING IN MAINLY SNOW. WE STILL THINK THERE
COULD BE SOME PATCHY FREEZING DRIZZLE OVERNIGHT AND CONTINUE TO
MENTION IN THE FORECAST.
UPDATE ISSUED AT 711 PM CST WED JAN 6 2016
AREA RADARS HAVE SHOWN ECHOES INCREASING IN BOTH COVERAGE AND
STRENGTH EARLY THIS EVENING...PARTICULARLY OVER NORTHERN
WISCONSIN. THIS IS ON TRACK WITH THE FORECAST AND LATEST GUIDANCE. WE
WILL ADJUST POPS THIS EVENING TO ACCOUNT FOR THE LATEST RADAR
TRENDS.
WE INCREASED POPS OVER OUR NORTHWEST CWA LATE TONIGHT AS SEVERAL
OF THE MODELS INDICATE AN ENHANCED BAND OF SNOW WILL BE POSSIBLE
THERE. THERE WILL BE SOME MAINLY WEAK FGEN IN THAT
AREA...ESPECIALLY IN THE LOW LEVELS. BASED ON STRENGTH OF THE
FORCING...WE INCREASED POPS TO LIKELY BUT ONLY NUDGED SNOW AMOUNTS
A FEW TENTHS OF AN INCH BOTH 06Z-12Z TONIGHT AND INTO THURSDAY
MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 334 PM CST WED JAN 6 2016
S/W TROF AXIS OVER IOWA LATE THIS AFTERNOON IS ACCOMPANIED BY A
FAIRLY LARGE PRECIP SHIELD..AND THIS WAVE WILL LIFT INTO WISCONSIN
TONIGHT. KMPX/KDLH/KARX RADARS INDICATE THAT PRECIP IS TRYING TO
EXPAND NORTHEASTWARD AHEAD OF THIS FEATURE IN MODESTLY STRONG
ASCENT..BRINGING A 4-8 HOUR PERIOD OF LIGHT PRECIP TO ROUGHLY THE
SOUTHEAST THIRD TO HALF OF THE DLH CWA TONIGHT/THUR MORNING. IN
GENERAL..AS THE WAVE LIFTS NEWD..DEEP LAYER SATURATION THROUGH A
SUFFICIENTLY DEEP LAYER BELOW -10C SHOULD RESULT IN MOST OF THE
PRECIP BEING LIGHT SNOW. HOWEVER..IN AREAS WHERE THE DRY LAYER
ALOFT IS SUFFICIENTLY DEEP TO NOT BE SATURATED..AREAS OF FREEZING
DRIZZLE/FLURRIES/FOG WILL PERSIST THROUGH TOMORROW. A GENERAL 1-2
INCH EVENT IS ANTICIPATED OVER MOST OF NW WISCONSIN TONIGHT/THUR
MORNING..WITH THE TWIN PORTS AND N SHORE AREAS BEING ON THE FAR
NORTHWEST EDGE OF THE MORE ORGANIZED PRECIP AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 334 PM CST WED JAN 6 2016
A SHORTWAVE WILL LIFT NORTHWARD THROUGH WISCONSIN THURSDAY NIGHT AND
FRIDAY IN THE BROAD SOUTHERLY UPPER LEVEL FLOW AHEAD OF AN UPPER
LEVEL LOW OVER THE CENTRAL PLAINS. LIGHT EASTERLY FLOW OVER THE
NORTHLAND WILL BECOME NORTHERLY DURING THIS TIME WHEN AN INVERTED
SURFACE TROUGH SLOWLY MOVES EAST THROUGH THE NORTHLAND. THE
SHORTWAVE AND TROUGH WILL BRING WIDESPREAD LIGHT TO MODERATE SNOW
TO THE NORTHLAND THURSDAY NIGHT AND FRIDAY. NORTHWEST WISCONSIN
AND THE ARROWHEAD ARE FORECAST TO GET ABOUT 2 TO 4 INCHES...WHILE
THE REST OF NE MINNESOTA ABOUT 1 TO 3 INCHES. EARLIER FORECASTS
HAD A MIXTURE OF RAIN AND SNOW...BUT THE LATEST GFS BUFR SOUNDINGS
SUGGEST THE PROFILES ARE SUFFICIENTLY DEEPLY SATURATED AND COLD TO
RESULT IN PRIMARILY SNOW.
A STRONG COLD NW FLOW COLD AIR BLAST WILL COME FRIDAY AND THROUGH
THE WEEKEND AS A DEEP UPPER LEVEL LOW DIGS OUT OF NORTHERN CANADA TO
ONTARIO AND THE NORTHERN GREAT LAKES. THE COLD NW FLOW WILL RESULT
IN LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH SHORE SNOW BELT REGION
THROUGH SUNDAY. LOWERED TEMPERATURES FOR THE LATE WEEKEND AND EARLY
NEXT WEEK BASED ON A BLEND OF THE GFS/CANADIAN/ECMWF.
TEMPERATURES WILL BOTTOM OUT ON SUNDAY WITH HIGHS MOSTLY BELOW
ZERO DEGREES.
THERE WILL LIKELY BE SOME TEMPERATURE RECOVERY MONDAY AND
TUESDAY...BUT HIGHS WILL STILL ONLY BE IN THE SINGLE DIGITS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1133 PM CST WED JAN 6 2016
AN AREA OF LOW PRESSURE ALONG WITH A PAIR OF SHORTWAVE TROUGHS
WILL COMBINE TO PRODUCE SNOW AND SOME FREEZING DRIZZLE ACROSS THE
NORTHLAND TONIGHT. THE PRECIPITATION WILL GRADUALLY DIMINISH FROM
SOUTH TO NORTH LATE TONIGHT INTO THURSDAY. MAINLY IFR OR LIFR
CONDITIONS WILL PREVAIL THROUGH THE PERIOD. THERE WERE STILL SOME
POCKETS OF MVFR CONDITIONS...BUT THOSE WILL LOWER OVER THE NEXT
COUPLE HOURS.
PRECIP TYPE WILL MAINLY BE LIGHT SNOW BUT THERE WILL STILL BE SOME
AREAS OF FREEZING DRIZZLE...ESPECIALLY SOUTH OF HIGHWAY 2.
VSBYS SHOULD REMAIN REDUCED EVEN AFTER THE MAIN AREA OF
PRECIPITATION MOVES THROUGH DUE TO FOG.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 30 29 31 / 90 50 30 50
INL 21 28 26 28 / 60 70 50 40
BRD 27 30 27 32 / 70 30 30 50
HYR 26 33 28 34 / 90 50 70 70
ASX 27 33 28 34 / 90 50 70 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1000 AM CST THU JAN 7 2016
.UPDATE...LATEST SATELLITE IMAGERY AND UPPER AIR ANALYSIS SHOWED A
LOW TO MID LEVEL CLOSED LOW OVER THE TEXAS PANHANDLE WITH AN
ASSOCIATED SHORT WAVE EXTENDING SOUTHEAST THROUGH THE ARKLATEX
REGION. THERE WAS SOME UPPER DIVERGENCE FROM THE WEST WITH SOME LOW
LEVEL SOUTHERLY FLOW. THERE WAS WEAK MOISTURE TRANSPORT AS AREA
RADARS WERE PICKING UP SOME LIGHT SHOWERS AROUND THE MS RIVER AREA.
JAN 12Z SNDING SHOWED A LAYER OF DRY AIR ABOUT 4KFT THICK WHICH WAS
MAKING THE PRECIP A LITTLE TOUGHER TO MAKE IT TO THE SFC...WHICH HAS
RESULTED IN VERY LIGHT RAINFALL. AREA SNDGS WERE SHOWING PWATS UNDER
0.50 INCH. LATEST CONVECTIVE ALLOWING GUIDANCE SHOWED THAT THE
PRECIP WILL BREAK UP AS IT MOVES EAST OF INTERSTATE 55 FOR THIS
AFTERNOON AND DECREASE IN COVERAGE AS IT MOVES FARTHER AWAY FROM
UPPER SHORTWAVE ENERGY SUPPORT. 12Z NAM AND HRRR SHOWS SOME ELEVATED
INSTABILITY FOR SOME ISOLATED THUNDER POTENTIAL FOR LATE THIS
MORNING INTO THIS AFTERNOON. SO WITH THIS IN MIND HAVE LOWERED TODAY
AND TONIGHT POPS TO THE CHANCE CATEGORY WITH ISOLATED THUNDER. AS
FAR AS TEMPS ARE CONCERN WILL HOLD ON TO CURRENT HIGHS IN THE MIDDLE
50S NORTH TO THE LOWER 60S SOUTHWEST./17/
&&
.AVIATION...LIGHT RAIN WITHOUT MUCH VSBY RESTRICTION WILL PUSH
THROUGH THE AREA TODAY. AS THE RAIN MOVES EAST OF THE AREA LATER
TODAY AND TONIGHT...IFR CIGS ARE EXPECTED TO PUSH INTO THE AREA.
THERE IS THE POSSIBILITY OF LIFR CIGS AND VSBY LATE TONIGHT INTO
FRIDAY MORNING. WILL BE EVALUATING THAT POTENTIAL FOR THE 18Z
TAF ISSUANCE. /SW/
&&
./PREVIOUS DISCUSSION...405 AM CST THU JAN 7 2016
.SHORT TERM...TODAY THROUGH FRIDAY...SHOWERS AND ISOLATED
THUNDERSTORMS ARE MOVING ACROSS LOUISIANA THIS MORNING ASSOCIATED
WITH A SHORT WAVE IN EAST TEXAS. THESE SHOWERS WILL CONTINUE TO MOVE
INTO OUR WESTERN PARISHES BY 10-12Z AND MOVE ACROSS OUR AREA THROUGH
THE AFTERNOON HOURS. MODELS SUGGEST ENOUGH INSTABILITY FOR AT LEAST
ISOLATED THUNDERSTORM ACTIVITY ACROSS THE AREA LATER THIS MORNING
AND AFTERNOON. IT CONTINUES TO LOOK LIKE RAINFALL AMOUNTS WILL
GENERALLY BE ON THE LIGHT SIDE...BUT SOME AREAS COULD RECEIVE
ANYWHERE FROM AROUND A QUARTER TO A HALF INCH. LIGHT RAINSHOWERS
WILL CONTINUE TO BE POSSIBLE INTO THE EVENING HOURS IN THE EAST
BEFORE ENDING OVERNIGHT AS MUCH DRIER AIR BUILDS IN.
PWATS WILL GENERALLY REMAIN BELOW A HALF AN INCH ON FRIDAY AND WITH
WITH STRONG SOUTHERLY FLOW...TEMPERATURES WILL CLIMB INTO THE UPPER
60S TO AROUND 70 FOR MUCH OF THE AREA./15/
.LONG TERM...FRIDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK...THE
SOUTHERN BRANCH OF THE JET STREAM LOOKS TO REMAIN ACTIVE AND
SUPPRESSED INCREASINGLY TO THE SOUTH OVER THE LONG TERM PERIOD.
TEMPERATURES SHOULD TREND BELOW NORMAL.
THE FIRST DISTURBANCE IN THE LONG TERM PERIOD (WHICH WE HAVE BEEN
WATCHING FOR A WHILE) IS NOW PLOWING TOWARD THE FOUR CORNERS REGION
AFTER BRINGING CALIFORNIA ANOTHER HEAVY DOSE OF PRECIPITATION.
MODELS CONTINUE TO SPEED UP WITH THE FAST PROGRESSION OF THIS SYSTEM
TOWARDS THE LOWER MS VALLEY...AND IT NOW LOOKS LIKE MOST OF THE
AREA`S PCPN WITH THIS SYSTEM MAY FALL BETWEEN MIDNIGHT FRIDAY NIGHT
AND 10 AM SATURDAY MORNING. THE UPPER AIR DISTURBANCE IS VERY POTENT
AND DEEP AND IT SHOULD ALSO GENERATE A SURFACE LOW WHICH TRACKS
QUICKLY BY THE NORTHWEST CORNER OF THE REGION DURING THIS TIME.
DESPITE THIS SOMEWHAT WORRISOME-SOUNDING COMBO...AND THE FACT THAT
LAPSE RATES ALOFT WILL BE STEEP...NO HAZARDOUS WEATHER IS EXPECTED
AT THIS TIME. THE REASONING FOR THE LATTER IS PRIMARILY DUE TO
LIMITED MOISTURE GETTING INCORPORATED INTO THIS SYSTEM IN OUR
REGION (MAINLY BECAUSE IT IS COMING SO QUICKLY ON THE HEELS OF
TODAY`S INCLEMENT WEATHER). STILL...WE COULD DEFINITELY EXPERIENCE A
FEW STORMS EMBEDDED IN THE SHOWERS LATE FRIDAY NIGHT THROUGH MIDDAY
SATURDAY...AND IT IS NOT INCONCEIVABLE THAT A FEW STORMS COULD
PRODUCE SOME SMALL HAIL OWING TO VERY COLD TEMPERATURES ALOFT. A
PLEASANT BY-PRODUCT OF THE FORWARD ADJUSTMENT OF THE SCHEDULE
OF SATURDAY`S RAIN IS THAT SOME AREAS (PARTICULARLY OVER NE LA
AND SOUTHERN MS) COULD EXPERIENCE A FEW HOURS OF SUN IN THE
AFTERNOON WITH TEMPS NOT TOO SHABBY.
BUT BY SATURDAY NIGHT THE EXPECTED COLD FRONT STILL LOOKS TO COME IN
FROM THE NORTHWEST AND PASS THROUGH ALL THE REGION BY SUNDAY
MORNING. TEMPERATURES WILL FALL OFF PRETTY QUICKLY IN THE WAKE OF
THE BOUNDARY WITH GUSTY NORTHWEST WINDS TO INCREASE THE WIND CHILL.
FORTUNATELY...AT LEAST SCATTERED SUNSHINE IN THE AFTERNOON SHOULD
HELP WARM TEMPS SOLIDLY ABOVE THE 40 DEGREE MARK EVERYWHERE EXCEPT
ALONG AND NORTH OF THE HIGHWAY 82 CORRIDOR.
SUNDAY NIGHT INTO TUESDAY WILL FEATURE SEASONABLY CHILLY TEMPS AND
MOSTLY CLEAR TO PARTLY CLOUDY SKIES UNDER THE INFLUENCE OF SURFACE
HIGH PRESSURE. EXPECT THE ENTIRE REGION TO GET BELOW OR VERY NEAR
FREEZING SUNDAY AND MONDAY NIGHTS.
A REINFORCING COLD FRONT LOOKS TO SLIDE ACROSS THE REGION SOMETIME
LATE TUESDAY OR TUESDAY NIGHT AND SHOULD BE DRY...WITH THE BULK OF
THE FRIGID AIR REMAINING TO OUR NORTH. DESPITE THE LATTER FACT THE
PASSAGE OF THIS FRONT WILL WORK TO PROLONG OUR SEASONABLY CHILLY
TEMPS WELL INTO NEXT WEEK. THE PASSAGE OF A GULF LOW TO OUR SOUTH
STILL LOOKS POSSIBLE BETWEEN LATE WEDNESDAY AND NEXT THURSDAY WHICH
COULD BRING ANOTHER SHOT OF PCPN TO AT LEAST SOUTHERN ZONES. AT THIS
POINT THE POTENTIAL FOR ANY WINTRY WEATHER WITH THIS POSSIBLE SYSTEM
IS NOT LOOKING VERY HIGH...BUT IT IS OF COURSE SOMETHING WE WILL BE
KEEPING OUR EYE ON. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 57 45 70 52 / 37 26 9 61
MERIDIAN 56 43 67 50 / 42 40 9 55
VICKSBURG 58 46 71 53 / 51 20 12 67
HATTIESBURG 59 45 72 53 / 41 25 7 67
NATCHEZ 60 50 70 53 / 59 16 12 69
GREENVILLE 53 47 66 51 / 37 27 11 66
GREENWOOD 55 47 67 51 / 37 39 11 63
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/SW/15/BB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1150 PM CST WED JAN 6 2016
.UPDATE:
Issued at 936 PM CST Wed Jan 6 2016
Scattered rain continues to move across the area this evening. We
got reports of flurries and light sleet with the onset of this
rain as the atmosphere evaporately cooled as the rain fell in the
dry air. No reports of accumulations have been reported thus far.
Still appears that rain will become more likely across central MO
late tonight per the HRRR and RAP as shortwave currently over
southern high Plains approaches the area. Precipitation type still
should be rain as warm air gets advected in ahead of system. RAP
is also showing an increase in low level moisture convergence over
central MO toward 12Z. Rest of forecast looks good.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 431 PM CST Wed Jan 6 2016
Warm advection aloft is producing bands of weak showers across
Missouri and Illinois. Much of this precip isn`t reaching the
ground, however scattered traces and 0.01 inch rainfall amounts keep
popping up on the hourly precip map...so have kept slight chance in
the forecast across central and northeast MO and west central IL for
the rest of the afternoon. Expect the areal coverage of the showers
to increase through the night...particularly over central Missouri
late. However...the precipitation will be fighting dry air in the
lower 3000-4000ft of the atmosphere so expect the rain to be very
light...perhaps not much more than sprinkles until near sunrise.
Southerly flow and plenty of cloud cover should keep temperatures
warmer than last night. MOS temperatures in the low to mid 30s look
reasonable so have followed closely.
Carney
.LONG TERM: (Thursday through Next Wednesday)
Issued at 431 PM CST Wed Jan 6 2016
...Thursday through Saturday...
This is expected to be an active period with broad SW flow with a
couple short waves expected to affect the region. Upper flow is
initially split with polar jet well north of the US/Canadian border
and the subtropical jet digging out a broad trough across the wrn
CONUS as it dives down the West Coast...into the Rio Grand
Valley...across the nthrn Gulf of MX and eventually by the end of
the prd...up the East Coast.
Weak short wave ridging is fcst to exit the NErn FA early Thu mrng.
Very light rain and/or sprinkles should be ongoing across cntrl
MO by 12Z with a band possibly extending NW into W cntrl IL. This
band may reach as far SE as the NWrn portion of the STL metro
area. Light rain should continue across cntrl MO thru the mrng but
the main push of moisture assoc with the upper lvl support won`t
really arrive until aftn though. Rain is expected to slowly spread
NE thru the day but progress will be slow...likely taking all day
to overspread areas east of STL...as the system overcomes dry air
in the lower lvls. QPF ranges between 0.25 to 0.75 inches with the
higher amounts across cntrl MO where the best forcing and moisture
is expected to be. Trough axis passes late Thu night into Fri mrng
as the SFC low tracks from the sthrn Plains to NW MO. Precip
should lift NE thru the evng...ending across NErn zones after
midnight as the SFC low passes...though can`t rule out some
drizzle areawide. The SFC low is fcst to continue NE into the Grt
Lks by Sat mrng.
Another low amplitude mid lvl ridge builds in for Fri aftn and
Fri evng before heights begin falling again. The cold front extending
from the first SFC low is expected to become stnry across the CWA
Fri night in response to the second short wave approaching. This
system is fcst to track further south...though how far south is in
question. The NAM wants to deepen and close off the mid level
circulation Sat aftn/evng as it passes...taking the SFC low
across SErn MO and sthrn IL...which would give the area the best
chance for winter precip. But it is an outlier. The GFS is the
farthest NW taking the SFC low just NW of the STL metro...and the
ECMWF is somewhere in between. Guidance has trended NW with recent
systems so tend to lean towards the GFS solution. Rain assoc with
WAA is expected to dvlp across SErn MO Fri night and then lift NE
into sthrn IL Sat mrng...with lighter precip for cntrl and NE MO
and W cntrl IL. The heaviest QPF...on the order of 0.50 to 0.75
inches...should fall across SErn MO and sthrn IL. SFC low lifts NE
thru the CWA Sat allowing for decent CAA...esp drng the aftn.
There will likely be a nondiurnal temp trend on Sat...esp NW of
the STL metro area. I think the Schmocker rule will be in full
effect with this event meaning the precip should be ending as
temps get cold enough for a transition to snow. This system bears
watching though.
Temps will be above normal thru the prd with lows aoa normal daytime
highs both Thu and Fri nights.
It has been 10 days since the record setting rains so hoping the
half to one inch rainfall totals expected thru Sat evng do not cause
any additional flooding concerns. Even if the rain does cause
renewed flooding...it should remain minimal.
...Saturday night through Tuesday...
The system will continue to pull away Sat night with CAA in full
force in response to a 1030mb SFC ridge building in from the nthrn
Plains. Sun will be a true winter day with highs mid teens north
to low 30s south and a stiff NW wind. The center of the SFC high
drifts nearly overhead late Sun night into Mon mrng which sets
the stage for a cold night due to good radiational cooling. Min
temps by Mon mrng are expected to range from the mid single digits
north to mid teens south. Temps will already be moderating by
early next week approaching seasonal norms by Tue. A weak cold
front on Tue may drop temps a bit for Wed. Keep in mind that if
the area does receive snow Sat PM then areas with snow cover will
be even colder than the going fcst indicates.
2%
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1144 PM CST Wed Jan 6 2016
Rain will become more predominate through the period has an upper
level storm system approaches the area from the west. MVFR
ceilings currently at KUIN southwestward into west central
Missouri will move eastward and spread into KCOU and the St. Louis
metro area TAF sites later tonight and during the day tomorrow as
light rain becomes steady across the area. Wet runways can be
expected.
Specifics for KSTL: Expect spotty rain across the area tonight
into early tomorrow with VFR conditions before steady rain with
MVFR conditions moves into the area on Thursday afternoon. Wet
runways can be expected once the steady rain begins.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1224 PM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 1205 AM CST THU JAN 7 2016
EARLIER THIS MORNING...EXTENDED THE FOG HEADLINE. ALTHOUGH
VISIBILITIES...HAVE IMPROVED IN SOME LOCATIONS WITH THE RAIN
MOVING IN FROM THE SOUTH AND FOR PARTS OF NORTHEAST NEBRASKA.
WILL CONTINUE TO MENTION DENSE FOG NORTH OF THE RAIN AREA THIS
AFTERNOON.
WITH THE MORNING MODEL RUNS...THE NAM IS TOO COLD WITH THE SURFACE
TEMPERATURES AND THIS WILL BE CRITICAL FOR PRECIP TYPE. THE
NAM/GFS KEEP THE HIGHER PRECIP WHERE IT REMAINS LIQUID THIS
AFTERNOON. THE RUC IS A BIT FARTHER NORTH INTO THE COLDER AIR.
RAISED SOME OF THE QPF AMOUNTS WITH THE RAIN BAND. WILL CONTINUE
TO MONITOR SHORT TERM TRENDS AS THE SHORTWAVE MOVES INTO THE AREA
AND THE PRECIPITATION TYPE BECOMES A MIX OR ALL SNOW ON THE
WESTERN/COOLER SIDE OF THE SYSTEM. THE HRRR EXP TRIES TO HAVE A
MIX/SNOW AS EARLY AS THIS AFTERNOON JUST WEST OF THE METRO AREA.
FORECAST SOUNDINGS ARE ISOTHERMAL AND THERE MAY BE PERIODS OF
PRECIP TYPE SWITCHING BACK AND FORTH UNTIL THE AIRMASS IS
SUFFICIENTLY COOL...AS THE SURFACE LOW TRACKS INTO EASTERN KANSAS
AND WESTERN IOWA.
UPDATE ISSUED AT 525 AM CST THU JAN 7 2016
DENSE FOG HAD BECOME A BIT MORE WIDESPREAD THE PAST FEW HOURS...SO
DECIDED TO ISSUE A DENSE FOG ADVISORY UNTIL 9 AM CST FOR A LARGE
PART OF THE FORECAST AREA. NO OTHER CHANGES TO PREVIOUS FORECAST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
THE MAIN FORECAST ISSUES REVOLVE AROUND PCPN TYPE AND PCPN AMOUNTS...
INCLUDING SOME LIGHT SNOW ACCUMULATIONS.
UPPER AIR CHARTS FROM 00Z SHOWED THE FOLLOWING MAIN FEATURES. AT
300 MB...STRONGEST WINDS (UP TO ABOUT 130 KNOTS) WERE MOVING
EASTWARD FROM THE PACIFIC ACROSS NORTHERN MEXICO. A BLOCKING
RIDGE AT 500 MB WAS CENTERED ALONG THE BORDER OF THE YUKON AND
NORTHWEST TERRITORIES...WHILE A TROUGH STRETCHED FROM THE GULF OF
ALASKA DOWN TO OFF THE CALIFORNIA COAST. AT 700 MB...THERE WAS A
LACK OF A BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS. THE COLDEST
AIR AT THIS LEVEL WAS ALONG THE WEST COAST. THERE WAS MORE OF A
THERMAL CONTRAST NOTED AT 850 MB ACROSS THE NORTHERN AND CENTRAL
PLAINS...WITH -8 C AT KBIS...RANGING TO +2C AT KTOP. THE KOAX
SOUNDING SHOWED ABOUT 0.51 INCHES OF PW...AND IT WAS NEARLY
SATURATED UP TO 6000 FEET AGL. SFC ANALYSIS EARLY THIS MORNING
SHOWED LOW PRESSURE CENTERS OVER COLORADO AND EASTERN SOUTH
DAKOTA. SOUTHEAST SURFACE WINDS WERE IN PLACE OVER EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH TEMPERATURES IN THE LOWER AND
MID 30S.
A SHORTWAVE HAD MOVED ACROSS THE CENTRAL PLAINS YESTERDAY...AND WAS
MOVING TOWARD THE WESTERN GREAT LAKES REGION. THE NEXT SHORTWAVE OF
CONCERN WAS DEPICTED FAIRLY WELL WITH A COMBINATION OF RECENT WATER
VAPOR SATELLITE IMAGERY AND RUC MODEL INITIALIZATIONS...NEAR THE
BORDER OF NEW MEXICO...TEXAS AND OKLAHOMA. THAT FEATURE SHOULD MOVE
TOWARD CENTRAL KANSAS BY LATE AFTERNOON AND HELP BRING INCREASING
MOISTURE (DEEPER) AND LIFT TO THE LOCAL AREA. AREAS OF DRIZZLE...
FOG AND LIGHT RAIN SHOULD PERSIST THIS MORNING...WITH LIGHT RAIN
BECOMING MORE WIDESPREAD IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
THIS AFTERNOON. THERE WILL BE A CHANCE OF A MIX OF SNOW...SLEET
AND RAIN IN MUCH OF NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
THE SHORTWAVE TROUGH THAT IS EXPECTED TO BE OVER KANSAS BY LATE
AFTERNOON WILL TRACK NORTHEAST INTO SOUTHERN IOWA FRIDAY AND WEAKEN.
THEN A MORE COMPLEX LIFT PATTERN WILL OCCUR AS ANOTHER DISTURBANCE
LIFTS EAST/NORTHEAST ACROSS KANSAS FRIDAY NIGHT INTO SATURDAY
MORNING AND A COLD TROUGH STARTS DIGGING INTO THE NORTHERN PLAINS.
MIXED PCPN SHOULD CHANGE TO MOSTLY SNOW IN NORTHEAST NEBRASKA AS
WINDS SHIFT TO THE NORTH TONIGHT AND A FEW INCHES OF SNOW MAY
ACCUMULATE. COLDER AIR WILL SPREAD OVER THE REST OF THE AREA FOR
LATE TONIGHT AND THROUGH FRIDAY...WHICH WILL CHANGE THE PCPN TO
MAINLY SNOW FROM NORTHWEST TO SOUTHEAST BY FRIDAY NIGHT. THE SNOW
SHOULD END SATURDAY...AS COLD HIGH PRESSURE STARTS TO BUILD INTO
THE AREA. BY 00Z SUNDAY...HIGH PRESSURE WITH A CENTER OF ABOUT
1031 MB SHOULD BE OVER NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
COLD AIR SHOULD DOMINATE THE FIRST PART OF THIS PERIOD...AS A COLD
NORTH/NORTHWEST FLOW ALOFT BRINGS CANADIAN AIR DOWN INTO OUR AREA.
TEMPERATURES ARE EXPECTED TO MODERATE A BIT BY WEDNESDAY AND
THURSDAY...AS THE FLOW TURNS MORE TOWARD THE WEST. AT THIS TIME...
NO SIGNIFICANT PCPN IS EXPECTED. LIGHT SNOW IS POSSIBLE MONDAY
OVER THE DAKOTAS AND MINNESOTA. AT THIS TIME...EXPECT THAT TO STAY
TO THE NORTH OF OUR AREA.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1205 PM CST THU JAN 7 2016
MVFR/LIFR/VLIFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD.
VISIBILITIES RANGING FROM 1/4 TO 3/4 MILE AT KOMA AND KLNK...AND
1 TO 3 MILES KOFK. AS THE RAIN MOVES NORTH SHOULD SEE LOW VSBYS
IMPROVING...WILL ALSO TRANSITION TO SNOW AT KOFK...A RAIN/SNOW AND
SNOW MIX AT OMAHA AND LINCOLN WITH ON AND OFF/SPOTTY PRECIP
00Z THROUGH 12Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...ZAPOTOCNY
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
525 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 525 AM CST THU JAN 7 2016
DENSE FOG HAD BECOME A BIT MORE WIDESPREAD THE PAST FEW HOURS...SO
DECIDED TO ISSUE A DENSE FOG ADVISORY UNTIL 9 AM CST FOR A LARGE
PART OF THE FORECAST AREA. NO OTHER CHANGES TO PREVIOUS FORECAST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
THE MAIN FORECAST ISSUES REVOLVE AROUND PCPN TYPE AND PCPN AMOUNTS...
INCLUDING SOME LIGHT SNOW ACCUMULATIONS.
UPPER AIR CHARTS FROM 00Z SHOWED THE FOLLOWING MAIN FEATURES. AT
300 MB...STRONGEST WINDS (UP TO ABOUT 130 KNOTS) WERE MOVING
EASTWARD FROM THE PACIFIC ACROSS NORTHERN MEXICO. A BLOCKING
RIDGE AT 500 MB WAS CENTERED ALONG THE BORDER OF THE YUKON AND
NORTHWEST TERRITORIES...WHILE A TROUGH STRETCHED FROM THE GULF OF
ALASKA DOWN TO OFF THE CALIFORNIA COAST. AT 700 MB...THERE WAS A
LACK OF A BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS. THE COLDEST
AIR AT THIS LEVEL WAS ALONG THE WEST COAST. THERE WAS MORE OF A
THERMAL CONTRAST NOTED AT 850 MB ACROSS THE NORTHERN AND CENTRAL
PLAINS...WITH -8 C AT KBIS...RANGING TO +2C AT KTOP. THE KOAX
SOUNDING SHOWED ABOUT 0.51 INCHES OF PW...AND IT WAS NEARLY
SATURATED UP TO 6000 FEET AGL. SFC ANALYSIS EARLY THIS MORNING
SHOWED LOW PRESSURE CENTERS OVER COLORADO AND EASTERN SOUTH
DAKOTA. SOUTHEAST SURFACE WINDS WERE IN PLACE OVER EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH TEMPERATURES IN THE LOWER AND
MID 30S.
A SHORTWAVE HAD MOVED ACROSS THE CENTRAL PLAINS YESTERDAY...AND WAS
MOVING TOWARD THE WESTERN GREAT LAKES REGION. THE NEXT SHORTWAVE OF
CONCERN WAS DEPICTED FAIRLY WELL WITH A COMBINATION OF RECENT WATER
VAPOR SATELLITE IMAGERY AND RUC MODEL INITIALIZATIONS...NEAR THE
BORDER OF NEW MEXICO...TEXAS AND OKLAHOMA. THAT FEATURE SHOULD MOVE
TOWARD CENTRAL KANSAS BY LATE AFTERNOON AND HELP BRING INCREASING
MOISTURE (DEEPER) AND LIFT TO THE LOCAL AREA. AREAS OF DRIZZLE...
FOG AND LIGHT RAIN SHOULD PERSIST THIS MORNING...WITH LIGHT RAIN
BECOMING MORE WIDESPREAD IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
THIS AFTERNOON. THERE WILL BE A CHANCE OF A MIX OF SNOW...SLEET
AND RAIN IN MUCH OF NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
THE SHORTWAVE TROUGH THAT IS EXPECTED TO BE OVER KANSAS BY LATE
AFTERNOON WILL TRACK NORTHEAST INTO SOUTHERN IOWA FRIDAY AND WEAKEN.
THEN A MORE COMPLEX LIFT PATTERN WILL OCCUR AS ANOTHER DISTURBANCE
LIFTS EAST/NORTHEAST ACROSS KANSAS FRIDAY NIGHT INTO SATURDAY
MORNING AND A COLD TROUGH STARTS DIGGING INTO THE NORTHERN PLAINS.
MIXED PCPN SHOULD CHANGE TO MOSTLY SNOW IN NORTHEAST NEBRASKA AS
WINDS SHIFT TO THE NORTH TONIGHT AND A FEW INCHES OF SNOW MAY
ACCUMULATE. COLDER AIR WILL SPREAD OVER THE REST OF THE AREA FOR
LATE TONIGHT AND THROUGH FRIDAY...WHICH WILL CHANGE THE PCPN TO
MAINLY SNOW FROM NORTHWEST TO SOUTHEAST BY FRIDAY NIGHT. THE SNOW
SHOULD END SATURDAY...AS COLD HIGH PRESSURE STARTS TO BUILD INTO
THE AREA. BY 00Z SUNDAY...HIGH PRESSURE WITH A CENTER OF ABOUT
1031 MB SHOULD BE OVER NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
COLD AIR SHOULD DOMINATE THE FIRST PART OF THIS PERIOD...AS A COLD
NORTH/NORTHWEST FLOW ALOFT BRINGS CANADIAN AIR DOWN INTO OUR AREA.
TEMPERATURES ARE EXPECTED TO MODERATE A BIT BY WEDNESDAY AND
THURSDAY...AS THE FLOW TURNS MORE TOWARD THE WEST. AT THIS TIME...
NO SIGNIFICANT PCPN IS EXPECTED. LIGHT SNOW IS POSSIBLE MONDAY
OVER THE DAKOTAS AND MINNESOTA. AT THIS TIME...EXPECT THAT TO STAY
TO THE NORTH OF OUR AREA.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 512 AM CST THU JAN 7 2016
LIFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD. VISIBILITIES
RANGING FROM 1/4 TO 1/2 MILE AT KOFK AND KLNK...AND 1/2 TO 1 AT
KOMA. SHOULD SEE RAIN DEVELOP AT KLNK/KOMA BY 19Z AND CONTINUE...
POSSIBLY BECOMING A WINTRY MIX BY 08/08Z. SNOW DEVELOPS AT KOFK
BY 22Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ011-012-
016>018-030>033-042>045-050>053-065>068-078-088>090.
IA...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ069-079-
090.
&&
$$
UPDATE...MILLER
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
515 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
THE MAIN FORECAST ISSUES REVOLVE AROUND PCPN TYPE AND PCPN AMOUNTS...
INCLUDING SOME LIGHT SNOW ACCUMULATIONS.
UPPER AIR CHARTS FROM 00Z SHOWED THE FOLLOWING MAIN FEATURES. AT
300 MB...STRONGEST WINDS (UP TO ABOUT 130 KNOTS) WERE MOVING
EASTWARD FROM THE PACIFIC ACROSS NORTHERN MEXICO. A BLOCKING
RIDGE AT 500 MB WAS CENTERED ALONG THE BORDER OF THE YUKON AND
NORTHWEST TERRITORIES...WHILE A TROUGH STRETCHED FROM THE GULF OF
ALASKA DOWN TO OFF THE CALIFORNIA COAST. AT 700 MB...THERE WAS A
LACK OF A BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS. THE COLDEST
AIR AT THIS LEVEL WAS ALONG THE WEST COAST. THERE WAS MORE OF A
THERMAL CONTRAST NOTED AT 850 MB ACROSS THE NORTHERN AND CENTRAL
PLAINS...WITH -8 C AT KBIS...RANGING TO +2C AT KTOP. THE KOAX
SOUNDING SHOWED ABOUT 0.51 INCHES OF PW...AND IT WAS NEARLY
SATURATED UP TO 6000 FEET AGL. SFC ANALYSIS EARLY THIS MORNING
SHOWED LOW PRESSURE CENTERS OVER COLORADO AND EASTERN SOUTH
DAKOTA. SOUTHEAST SURFACE WINDS WERE IN PLACE OVER EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH TEMPERATURES IN THE LOWER AND
MID 30S.
A SHORTWAVE HAD MOVED ACROSS THE CENTRAL PLAINS YESTERDAY...AND WAS
MOVING TOWARD THE WESTERN GREAT LAKES REGION. THE NEXT SHORTWAVE OF
CONCERN WAS DEPICTED FAIRLY WELL WITH A COMBINATION OF RECENT WATER
VAPOR SATELLITE IMAGERY AND RUC MODEL INITIALIZATIONS...NEAR THE
BORDER OF NEW MEXICO...TEXAS AND OKLAHOMA. THAT FEATURE SHOULD MOVE
TOWARD CENTRAL KANSAS BY LATE AFTERNOON AND HELP BRING INCREASING
MOISTURE (DEEPER) AND LIFT TO THE LOCAL AREA. AREAS OF DRIZZLE...
FOG AND LIGHT RAIN SHOULD PERSIST THIS MORNING...WITH LIGHT RAIN
BECOMING MORE WIDESPREAD IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
THIS AFTERNOON. THERE WILL BE A CHANCE OF A MIX OF SNOW...SLEET
AND RAIN IN MUCH OF NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
THE SHORTWAVE TROUGH THAT IS EXPECTED TO BE OVER KANSAS BY LATE
AFTERNOON WILL TRACK NORTHEAST INTO SOUTHERN IOWA FRIDAY AND WEAKEN.
THEN A MORE COMPLEX LIFT PATTERN WILL OCCUR AS ANOTHER DISTURBANCE
LIFTS EAST/NORTHEAST ACROSS KANSAS FRIDAY NIGHT INTO SATURDAY
MORNING AND A COLD TROUGH STARTS DIGGING INTO THE NORTHERN PLAINS.
MIXED PCPN SHOULD CHANGE TO MOSTLY SNOW IN NORTHEAST NEBRASKA AS
WINDS SHIFT TO THE NORTH TONIGHT AND A FEW INCHES OF SNOW MAY
ACCUMULATE. COLDER AIR WILL SPREAD OVER THE REST OF THE AREA FOR
LATE TONIGHT AND THROUGH FRIDAY...WHICH WILL CHANGE THE PCPN TO
MAINLY SNOW FROM NORTHWEST TO SOUTHEAST BY FRIDAY NIGHT. THE SNOW
SHOULD END SATURDAY...AS COLD HIGH PRESSURE STARTS TO BUILD INTO
THE AREA. BY 00Z SUNDAY...HIGH PRESSURE WITH A CENTER OF ABOUT
1031 MB SHOULD BE OVER NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
COLD AIR SHOULD DOMINATE THE FIRST PART OF THIS PERIOD...AS A COLD
NORTH/NORTHWEST FLOW ALOFT BRINGS CANADIAN AIR DOWN INTO OUR AREA.
TEMPERATURES ARE EXPECTED TO MODERATE A BIT BY WEDNESDAY AND
THURSDAY...AS THE FLOW TURNS MORE TOWARD THE WEST. AT THIS TIME...
NO SIGNIFICANT PCPN IS EXPECTED. LIGHT SNOW IS POSSIBLE MONDAY
OVER THE DAKOTAS AND MINNESOTA. AT THIS TIME...EXPECT THAT TO STAY
TO THE NORTH OF OUR AREA.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 512 AM CST THU JAN 7 2016
LIFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD. VISIBILITIES
RANGING FROM 1/4 TO 1/2 MILE AT KOFK AND KLNK...AND 1/2 TO 1 AT
KOMA. SHOULD SEE RAIN DEVELOP AT KLNK/KOMA BY 19Z AND CONTINUE...
POSSIBLY BECOMING A WINTRY MIX BY 08/08Z. SNOW DEVELOPS AT KOFK
BY 22Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
315 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
THE MAIN FORECAST ISSUES REVOLVE AROUND PCPN TYPE AND PCPN AMOUNTS...
INCLUDING SOME LIGHT SNOW ACCUMULATIONS.
UPPER AIR CHARTS FROM 00Z SHOWED THE FOLLOWING MAIN FEATURES. AT
300 MB...STRONGEST WINDS (UP TO ABOUT 130 KNOTS) WERE MOVING
EASTWARD FROM THE PACIFIC ACROSS NORTHERN MEXICO. A BLOCKING
RIDGE AT 500 MB WAS CENTERED ALONG THE BORDER OF THE YUKON AND
NORTHWEST TERRITORIES...WHILE A TROUGH STRETCHED FROM THE GULF OF
ALASKA DOWN TO OFF THE CALIFORNIA COAST. AT 700 MB...THERE WAS A
LACK OF A BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS. THE COLDEST
AIR AT THIS LEVEL WAS ALONG THE WEST COAST. THERE WAS MORE OF A
THERMAL CONTRAST NOTED AT 850 MB ACROSS THE NORTHERN AND CENTRAL
PLAINS...WITH -8 C AT KBIS...RANGING TO +2C AT KTOP. THE KOAX
SOUNDING SHOWED ABOUT 0.51 INCHES OF PW...AND IT WAS NEARLY
SATURATED UP TO 6000 FEET AGL. SFC ANALYSIS EARLY THIS MORNING
SHOWED LOW PRESSURE CENTERS OVER COLORADO AND EASTERN SOUTH
DAKOTA. SOUTHEAST SURFACE WINDS WERE IN PLACE OVER EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH TEMPERATURES IN THE LOWER AND
MID 30S.
A SHORTWAVE HAD MOVED ACROSS THE CENTRAL PLAINS YESTERDAY...AND WAS
MOVING TOWARD THE WESTERN GREAT LAKES REGION. THE NEXT SHORTWAVE OF
CONCERN WAS DEPICTED FAIRLY WELL WITH A COMBINATION OF RECENT WATER
VAPOR SATELLITE IMAGERY AND RUC MODEL INITIALIZATIONS...NEAR THE
BORDER OF NEW MEXICO...TEXAS AND OKLAHOMA. THAT FEATURE SHOULD MOVE
TOWARD CENTRAL KANSAS BY LATE AFTERNOON AND HELP BRING INCREASING
MOISTURE (DEEPER) AND LIFT TO THE LOCAL AREA. AREAS OF DRIZZLE...
FOG AND LIGHT RAIN SHOULD PERSIST THIS MORNING...WITH LIGHT RAIN
BECOMING MORE WIDESPREAD IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
THIS AFTERNOON. THERE WILL BE A CHANCE OF A MIX OF SNOW...SLEET
AND RAIN IN MUCH OF NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
THE SHORTWAVE TROUGH THAT IS EXPECTED TO BE OVER KANSAS BY LATE
AFTERNOON WILL TRACK NORTHEAST INTO SOUTHERN IOWA FRIDAY AND WEAKEN.
THEN A MORE COMPLEX LIFT PATTERN WILL OCCUR AS ANOTHER DISTURBANCE
LIFTS EAST/NORTHEAST ACROSS KANSAS FRIDAY NIGHT INTO SATURDAY
MORNING AND A COLD TROUGH STARTS DIGGING INTO THE NORTHERN PLAINS.
MIXED PCPN SHOULD CHANGE TO MOSTLY SNOW IN NORTHEAST NEBRASKA AS
WINDS SHIFT TO THE NORTH TONIGHT AND A FEW INCHES OF SNOW MAY
ACCUMULATE. COLDER AIR WILL SPREAD OVER THE REST OF THE AREA FOR
LATE TONIGHT AND THROUGH FRIDAY...WHICH WILL CHANGE THE PCPN TO
MAINLY SNOW FROM NORTHWEST TO SOUTHEAST BY FRIDAY NIGHT. THE SNOW
SHOULD END SATURDAY...AS COLD HIGH PRESSURE STARTS TO BUILD INTO
THE AREA. BY 00Z SUNDAY...HIGH PRESSURE WITH A CENTER OF ABOUT
1031 MB SHOULD BE OVER NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
COLD AIR SHOULD DOMINATE THE FIRST PART OF THIS PERIOD...AS A COLD
NORTH/NORTHWEST FLOW ALOFT BRINGS CANADIAN AIR DOWN INTO OUR AREA.
TEMPERATURES ARE EXPECTED TO MODERATE A BIT BY WEDNESDAY AND
THURSDAY...AS THE FLOW TURNS MORE TOWARD THE WEST. AT THIS TIME...
NO SIGNIFICANT PCPN IS EXPECTED. LIGHT SNOW IS POSSIBLE MONDAY
OVER THE DAKOTAS AND MINNESOTA. AT THIS TIME...EXPECT THAT TO STAY
TO THE NORTH OF OUR AREA.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1122 PM CST WED JAN 6 2016
LIFR OR IFR CIGS AND VSBY WILL CONTINUE THROUGH MUCH OF THE PERIOD
AS NEXT UPPER LEVEL SYSTEM APPROACHES THE CENTRAL PLAINS REGION.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
916 PM EST FRI JAN 8 2016
.SYNOPSIS...
A WEAK FRONT WILL LIFT NORTHWARD THROUGH THE REGION TONIGHT AND
BRING A BRIEF PERIOD OF SNOW SLEET AND FREEZING RAIN. A SECOND
SYSTEM WILL MOVE IN FROM THE SOUTH SATURDAY NIGHT AND SUNDAY WITH
WIDESPREAD RAIN EXPECTED THROUGH SUNDAY AFTERNOON. AS THIS SYSTEM
EXITS A COLD AIR MASS WILL PUSH IN FROM THE NORTHWEST AND CHANGE
THE LINGERING RAIN OVER TO SNOW. A PERSISTENT WEST WIND WILL ALLOW
FOR LAKE EFFECT SNOW SHOWERS THROUGH MOST OF THE WEEK ACROSS THE
FINGER LAKES AND INTO THE TUG HILL PLATEAU. SIGNIFICANT SNOW
ACCUMULATIONS ARE POSSIBLE.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
855 PM UPDATE...
TWO POSITIVE SIGNS: TEMPERATURES ARE NOT FALLING AS QUICKLY AS
FEARED, AND THE RADAR PICTURE IS MORE SPARSE THAN EXPECTED. FOR
THIS REASON, WE BELIEVE LIGHT FREEZING RAIN WILL BE ISOLATED.
WE RAISED TEMPERATURES THROUGH THE NEXT 3-6 HOURS AND CUT BACK ON
THE POPS, MOVING MORE IN LINE WITH THE HRRR AND NAM12 RADAR PROGS.
350 PM UPDATE... A WINTER WEATHER ADVISORY FOR FREEZING RAIN IS
IN EFFECT TONIGHT FOR PORTIONS OF CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA.
A WEAK WARM FRONT CURRENTLY MOVING NEWD THROUGH OH/WV/VA THIS
AFTERNOON WILL SPREAD A NARROW BAND OF PRECIPITATION THROUGH THE
REGION TONIGHT. A LAYER OF MID LVL WAA COMBINED WITH A WEAK UPPER
S/W WILL TRIGGER AN INITIAL BAND OF PRECIP EARLY THIS EVENING. THE
SIGNIFICANT FACTOR WILL BE THE PRESENCE OF A WEDGE OF AIR BELOW
FREEZING NEAR THE SURFACE. A COLD AREA OF HIGH PRESSURE OVER ERN
QUEBEC EXTENDING SWD INTO NEW ENGLAND AND NOSING WWD INTO THE NRN
APPALACHIAN MTNS WILL KEEP A COLD AIR MASS IN PLACE AS THE WARM
AIR RIDES OVER THE TOP AND CREATES FAVORABLE THERMAL PROFILES FOR
FREEZING RAIN. ONE AREA OF CONCERN WILL BE THE NRN EDGE OF THE
ALLEGHENY MTNS IN THE HIGHER TERRAIN OF BRADFORD AND WYOMING
COUNTIES MAINLY THIS EVENING AND INTO THE EARLY OVERNIGHT. THE
SECOND AREA OF CONCERN WILL BE LOCATIONS EAST OF I-81 FROM THE SRN
TUG HILL PLATEAU INTO THE POCONO MTNS WHERE THE COLDEST SFC TEMPS
WILL BE LOCATED. THE FREEZING RAIN/DRIZZLE MAIN END UP LINGERING A
BIT LONGER AS THE BAND OF PRECIP EXITS TO THE E/NE SAT MORNING.
ICE ACCUMULATIONS WILL GENERALLY BE LESS THAN A TENTH OF AN
INCH...ALONG WITH LIGHT SNOW AMTS MIXED IN AT TIMES AS WELL. AREA
ROADS THAT ARE NOT TREATED MAY BECOME SLIPPERY TONIGHT AND
SATURDAY MORNING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
350 PM UPDATE... A WEAK RIDGE IS EXPECTED TO BUILD IN BEHIND THE
DEPARTING WARM FRONT/ UPPER TROUGH THROUGH THE DAY SATURDAY WITH
LINGERING LIGHT RAIN AND/OR DRIZZLE INTO SATURDAY NIGHT. A MUCH
MORE DYNAMIC STORM SYSTEM WILL LIFT NEWD FROM THE OHIO VALLEY INTO
THE WRN GREAT LAKES DURING THE DAY SUNDAY. A RELATIVELY STRONG
PUSH OF MOISTURE FROM THE SOUTH WILL BECOME ENTRAINED INTO THE
SYSTEM AND PRODUCE MODERATE PERSISTENT RAIN ACROSS THE REGION
THROUGH SUNDAY AFTERNOON. PWAT VALUES AROUND 0.8 INCH WITH THIS
SYSTEM WILL ALLOW FOR A HALF INCH TO 1.5 INCHES OF RAINFALL ON
SUNDAY. RAINFALL AMOUNTS SHOULD NOT BE SIGNIFICANT ENOUGH FOR
HYDRO ISSUES.
A STRONG PUSH OF COLD AIR WILL DEVELOP ON THE BACK SIDE OF THE
SYSTEM BEHIND THE COLD FRONT SUNDAY NIGHT AND ALLOW THE RAIN TO
MIX WITH INITIALLY AND EVENTUALLY CHANGE OVER TO ALL SNOW.
SNOWFALL AMOUNTS WILL NOT ADD UP TO MUCH AS THE AIR MASS BEHIND
THE FRONT IS EXPECTED TO BE RELATIVELY DRY. THIS ARCTIC AIR MASS
WILL BE FAVORABLE FOR LAKE EFFECT SNOW...AND THE TRAJECTORIES FROM
THE WEST WILL ALLOW FOR LES BANDS TO SET UP EAST OF LAKE ERIE AND
EAST OF ONTARIO...POSSIBLY IMPACTING STEUBEN COUNTY WITH LIGHT
SNOW AND THE SRN TUG HILL PLATEAU WITH EVEN MORE SNOW.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
350 PM UPDATE... THE COLD ARCTIC PATTERN WILL REMAIN IN PLACE
THROUGH MOST OF THE WEEK WITH 850MB TEMPS AROUND -15 TO -20 DEG C
BLOWING ACROSS RELATIVELY WARM LAKES OF ERIE AND ONTARIO. THE
DETERMINING FACTOR FOR WHERE THE HEAVIEST SNOW WILL SET UP WILL BE
THE RESULTING WIND FIELD. A WESTERLY WIND WILL KEEP THE BEST
CHANCE OF ACCUMULATING LES OVER NRN ONEIDA COUNTY MONDAY AND
TUESDAY...BUT SHIFT THE BAND TO THE NORTH TUE NIGHT AS THE NEXT
WEAK CLIPPER SYSTEM MOVES IN FROM THE WEST AND BACKS THE WINDS TO
THE SSW. THIS COLD S/W WILL TRIGGER ADDITIONAL MORE WIDESPREAD
SNOW SHOWERS LATE TUE INTO WED...BUT AMOUNTS WILL BE LIGHT AS THE
AIR MASS IS EXPECTED TO BE VERY DRY. THE COLD AIR ALOFT WILL
INDUCE THE STEEP LOW LEVEL LAPSE RATES AND BE THE MAIN DRIVING
FORCE FOR THE SNOW PRODUCTION.
AS THE SYSTEM EXITS EAST...WINDS WILL VEER TO THE NW LATE
WEDNESDAY AND COMBINE WITH ANOTHER PUSH OF ARCTIC AIR TO PRODUCE
ADDITIONAL LAKE EFFECT SNOW INTO WED NIGHT. THE PATTERN REPEATS
THURSAY INTO FRIDAY WITH THE PASSAGE OF ANOTHER S/W AND ADDITIONAL
LIGHT ACCUMULATING SNOW SHOWERS.
TEMPERATURES WILL REMAIN NEAR NORMAL MOST OF THE WEEK WITH HIGHS
IN THE MID TO UPPER 20S AND LOWS IN THE TEENS.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
A WARM FRONT WILL CROSS THE AREA OVERNIGHT BRINGING LOW CIGS AND LIGHT
RAIN AND DRIZZLE WHICH COULD BRIEFLY BEGIN AS FZRA AT SOME
TERMINALS. AT KRME/KSYR, CIGS WILL LOWER INTO THE MVFR CATEGORY
AROUND 03Z THEN AFTER 05Z LIGHT RAIN WITH CIGS LOW MVFR/IFR.
PRECIP WILL LIKELY START AS FZRA AT KRME FOR A COUPLE OF HOURS.
ON SATURDAY, AREAS OF DRIZZLE WITH CIGS REMAINING LOW MVFR. AT
KITH/KBGM, LOW MVFR CIGS WITH LIGHT RAIN BEGINNING AROUND 03Z
WHICH COULD START AS A BRIEF PERIOD OF FZRA. AFTER 06Z, DRIZZLE
WITH IFR/LOW MVFR CIGS THROUGH TAF PERIOD. AT KELM/KAVP, LOW MVFR
CIGS THROUGH THE PERIOD WITH RAIN/DRIZZLE BEGINNING AROUND 02Z.
WINDS E/SE 5-10 KNOTS.
.OUTLOOK...
SAT NIGHT-SUN...RESTRICTIONS POSSIBLE DUE TO RAIN SHOWERS. RAIN
MAY MIX WITH/CHANGE OVER TO SNOW SUNDAY AFTERNOON.
MON/TUE/WED...VFR...BUT SPOTTY MVFR/IFR PSBL IN LAKE EFFECT SNOW
SHWRS OVER NY STATIONS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR PAZ039-040-
044-048-072.
WINTER WEATHER ADVISORY UNTIL 5 AM EST SATURDAY FOR PAZ038-043.
NY...WINTER WEATHER ADVISORY UNTIL 7 AM EST SATURDAY FOR NYZ009-036-
037-045-046-056-057-062.
&&
$$
SYNOPSIS...BJT
NEAR TERM...BJT/DJP
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
645 AM EST THU JAN 07 2016
.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO EXTEND INTO THE AREA FROM
THE MID-ATLANTIC STATES THROUGH THE END OF THE WEEK. MEANWHILE...A
WEAKENING LOW PRESSURE SYSTEM WILL IMPACT THE AREA FRIDAY...FOLLOWED
BY A STRONGER SYSTEM AND UNSETTLED WEATHER ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM THURSDAY..
HIGH PRESSURE...MAINTAINED BY SHORTWAVE RIDGING ALOFT...CONTINUES TO
EXTEND FROM THE MID-ATLANTIC STATES THROUGH THE NC PIEDMONT...WITH A
FAIRLY PRONOUNCED INVERTED TROUGH OFFSHORE. ALOFT...THE FLOW IS
GENERALLY WEAK SOUTHWESTERLY WITH DISTURBANCES OFF THE GA/FL COAST
AND OVER THE SOUTHERN PLAINS. A SHALLOW LAYER OF MOISTURE IN
SOUTHEASTERLY FLOW ATOP THE SURFACE RIDGE HAS LED TO WIDESPREAD
STRATUS AND A SMALL AREA OF RECENTLY EXPANDING DRIZZLE JUST EAST OF
THE TRIANGLE AREA...WHICH ITSELF APPEARS TO BE FOCUSED WITHIN THE
REGION OF STRONGEST 925MB WARM ADVECTION. THE MOISTURE IS
SHALLOW...THOUGH SLIGHTLY DEEPER TOWARD THE COAST...AND LUCKILY
DEWPOINTS HAVE RECOVERED INTO THE 30S EVERYWHERE EXCEPT FOR THE FAR
WESTERN PIEDMONT. THIS POORLY RESOLVED AREA OF DRIZZLE SHOULD SHIFT
NORTH-NORTHWESTWARD THIS MORNING AND NOT CAUSE ANY PROBLEMS.
OTHERWISE TODAYS FORECAST CHALLENGE IS WHETHER OR NOT THE STRATUS
WILL PERSIST THROUGH THE DAY. THE 925NMB FLOW SHOULD BACK TO MORE
NORTHEASTERLY THIS MORNING IN RESPONSE TO THE AREA OF LOW PRESSURE
DEVELOPING WELL OFF THE SOUTHEAST COAST...AND THUS THE WARM
ADVECTION WILL DIMINISH. THE NAM AND GFS MAINTAIN THE STRATUS
THROUGH THIS AFTERNOON ON THE EAST WHERE THE MOISTURE IS ALREADY
DEEPER...WHILE BREAKING THE WESTERN PIEDMONT OUT. RAP RUNS HAVE
TENDED TO SCATTER OUT THE ENTIRE AREA. WILL TREND THE FORECAST
TOWARD A LITTLE LESS CLOUD COVER BY THIS AFTERNOON...ADMITTEDLY WITH
LOW CONFIDENCE. HIGHS MAY FEATURE A MORE EVEN DISTRIBUTION THAT
USUAL...WITH MID AND UPPER 40S FOR MOST AREAS. HOWEVER...IF CLOUDS
DO SCATTER THEN LOWER 50S ARE POSSIBLY FOR THE EASTERN HALF OF THE
AREA.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 340 AM THURSDAY...
WHAT MOISTURE IS STILL AROUND THIS EVENING SHOULD LEAD TO
REDEVELOPING STRATUS BENEATH THE INVERSION ALOFT TONIGHT.
MEANWHILE... THE AFOREMENTIONED UPPER DISTURBANCE OVER THE SOUTHERN
PLAINS WILL LIFT TOWARD THE UPPER MIDWEST TONIGHT AND FRIDAY..WHILE
THE EASTERN EXTENT OF THE TROUGH AXIS AND DCVA LIFT ACROSS THE
SOUTHEAST US. THE LEFT EXIT REGION OF THE STJ WILL PROVIDE SOME
UPPER DIVERGENCE...BUT LOW-LEVEL FORCING IS LACKING WITH THE COASTAL
TROUGH STAYING PUT AND PRETTY WEAK LOW-LEVEL FLOW/ADVECTION. THE
TREND IN THE MODELS TOWARD A DRIER FORECAST HAS STABILIZED AND THE
NAM/GFS/ECMWF ALL INDICATED JUST SOME VERY LIGHT SHOWERS DURING THE
DAY ON FRIDAY. WILL MAINTAIN A SLIGHT CHANCE TO CHANCE POP AFTER
12Z FRIDAY AND NO POPS FRIDAY NIGHT AHEAD OF THE NEXT SYSTEM TO
IMPACT THE AREA ON SATURDAY.
LOWS TONIGHT WILL DEPEND HOW MUCH WE SCATTER OUT TODAY AND HOW
QUICKLY CLOUDS INCREASE OVERNIGHT AHEAD OF THE APPROACHING TROUGH.
GIVEN NO CHANGE IN THE AIR MASS AND POTENTIAL FOR OVERCAST
AGAIN...LOWS SHOULD BE SIMILAR TO THIS MORNING...34-42 NW TO SE.
HIGHS FRIDAY COULD BE LOWER WITH MORE PRECIP...BUT WILL STILL
FEATURE A CAD-LIKE RANGE GIVEN THE SURFACE HIGH AND DIABATIC EFFECTS
OF THE LOW CLOUDS...MID 40S NW TO MID 50S SOUTHEAST. AND FINALLY
FRIDAY NIGHT LOWS WILL BE A TAD MILDER IN THE 40-48 RANGE AS
DEWPOINTS CREEP UP INTO THE LOWER 40S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 400 AM THURSDAY...
FORECAST CONFIDENCE CONTINUES TO INCREASE WITH RESPECT TO THE NEXT
RELATIVELY SIGNIFICANT SYSTEM EXPECTED TO AFFECT CENTRAL NC WITH A
HIGH PROBABILITY OF RAIN...AND ASSOCIATED WEAK HYBRID COLD AIR
DAMMING...EARLY THIS WEEKEND. IN FACT...THE MODELS ARE IN GOOD
OVERALL AGREEMENT REGARDING THE SYNOPTIC PATTERN...ONE CHARACTERIZED
BY A PRIMARY SURFACE LOW TRACK INTO THE GREAT LAKES AND SECONDARY
DEVELOPMENT ALONG A RETREATING COASTAL FRONT FROM THE GULF COAST TO
THE MIDDLE ATLANTIC PIEDMONT SAT-SAT NIGHT. THE PASSAGE OF THE
SECONDARY/TRIPLE POINT LOW AND ASSOCIATED LOW LEVEL THETA-E
ADVECTION MAY ALSO SUPPORT A FEW ELEVATED STORMS DURING THE
AFTERNOON AND EVENING SAT. THE EARLIER INDICATED FASTER TREND WITH
THIS SYSTEM REMAINS...WITH MOST OR ALL OF THE SHOWERS EAST AND
NORTHEAST OF CENTRAL NC BY DAYBREAK SUNDAY.
OTHERWISE...THE PATTERN FOR EARLY TO MID NEXT WEEK APPEARS TO BE A
RELATIVELY COOL AND DRY ONE...AS A BROAD TROUGH BECOMES ESTABLISHED
ACROSS THE EASTERN TWO THIRDS OF THE COUNTRY. THE ONE EXCEPTION WILL
BE A BRIEF PERIOD OF LIFT AS A SHORTWAVE TROUGH AND ACCOMPANYING JET
STREAK IN NW FLOW ALOFT AMPLIFY ACROSS THE APPALACHIANS LATE TUE
NIGHT-EARLY WED...AT WHICH TIME A FEW FLURRIES OR SPRINKLES WOULD BE
POSSIBLE IN AN OTHERWISE DRY REGIME BETWEEN UPSLOPE APPALACHIAN
PRECIPITATION AND OFFSHORE LOW PRESSURE...THE LATTER OF WHICH WOULD
BE SUPPORTED ALOFT BY THE AFOREMENTIONED SHORTWAVE TROUGH IN NW FLOW
ALOFT...WHICH MAY GRAZE COASTAL AREAS OF THE NORTHERN MIDDLE
ATLANTIC STATES AND/OR NEW ENGLAND ON WED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 645 AM THURSDAY...
SOUTHEASTERLY LOW LEVEL FLOW ABOVE THE HIGH PRESSURE AND NORTHEASTERLY
WINDS AT THE SURFACE CONTINUES TO SUPPORT LIFR TO MVFR CEILINGS AND
EVEN A LITTLE DRIZZLE AROUND KRDU AND TO THE EAST. THE MOIST LAYER
IS ONLY 1000 FT OR SO THICK BASED ON LAST EVENINGS RAOBS AND RECENT
PIREPS. THE LOW LEVEL FLOW IS FORECAST TO BACK AROUND TO
NORTHEASTERLY TODAY IN RESPONSE TO A SURFACE LOW OFF THE SOUTHEAST
COAST...WHICH SHOULD ALLOW SOME BREAKS IN THE STRATUS TO DEVELOP.
MODELS HAVE NOT BEEN IN GOOD AGREEMENT ON THE EXTENT OF THE BREAKS
AND WHEN VFR CONDITIONS COULD DEVELOP. GIVEN THE UNCERTAINTY...THE
CURRENT TAF WILL SHOW CONDITIONS IMPROVING TO MVFR BY EARLY
AFTERNOON...WITH IFR CONDITIONS REDEVELOPING OVERNIGHT.
OUTLOOK...A COUPLE OF LOW PRESSURE SYSTEMS WILL IMPACT THE REGION
THROUGH THE WEEKEND. DESPITE VERY LITTLE RAIN WILL THE FIRST
SYSTEM ON FRIDAY...MVFR/IFR CEILINGS ARE EXPECTED...CONTINUING
THROUGH SATURDAY AS A STRONGER SYSTEM BRING WIDESPREAD RAIN.
IMPROVING CONDITIONS ARE EXPECTED BY SUNDAY AND MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...22
SHORT TERM...22
LONG TERM...2
AVIATION...22
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
600 AM EST THU JAN 7 2016
.SYNOPSIS...
HIGH PRESSURE WILL PUSH DOWN THE COAST THROUGH FRIDAY WHILE A
COASTAL FRONT LINGERS OFFSHORE. A WEAK MID LEVEL IMPULSE WILL
BRING A CHANCE FOR SHOWERS ON FRIDAY. A WARM FRONT WILL LIFT
ACROSS THE AREA SATURDAY BRINGING GOOD CHANCES FOR RAIN INTO
SUNDAY ALONG WITH MUCH WARMER TEMPERATURES. MUCH COLDER
TEMPERATURES WILL FOLLOW A COLD FRONT EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM THURSDAY...WEAKENING HIGH PRESSURE WEDGE THE PRIMARY
FEATURE TODAY AND TONIGHT ACCOMPANIED BY MULTIPLE CLOUD LAYERING.
SOUTHERLY WINDS ABOVE 500 MB WILL DIRECT A COAT OF CIRRUS THROUGH
SC AND THE DEEPER INTERIOR OF SE NC...WITH A SMATTERING OF LOW
CLOUDS TRAPPED BENEATH A NOTABLE INVERSION TODAY. A TROUBLESOME
SKY FORECAST AS VARIABILITY IS EXPECTED NEAR THE COAST WITH MORE
STUBBORN COVERAGE LIKELY INLAND. THIS COMPLICATES MAXIMUM TEMPS
BUT MIDDLE 50S WELL INLAND TO NEAR 60 AT THE COAST ANTICIPATED.
STEERING FLOW WILL KEEP OCEAN SHOWERS MAINLY AT SEA AND THERE IS
LITTLE FORCING OVER LAND TO TRIGGER PCPN TODAY. AN EXCEPTIONALLY
DRY MID-LAYER WILL HOLD ITS GROUND TODAY. TONIGHT SHORT-WAVE
IMPULSING AND WEAK ISENTROPIC OMEGA FROM THE SW WILL ARRIVE IN THE
PRE-DAWN HOURS AND A SLIGHT CHANCE OF RAIN FOR SC INTO DAWN.
MINIMUMS LOW/MID 40S INLAND...AND UPPER 40S TO NEAR 50 COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...MID-LEVEL IMPULSE MOVING OVERHEAD FRIDAY
WILL COMBINE WITH INCREASING ISENTROPIC LIFT ALONG THE 300K SURFACE
ATOP A SURFACE WEDGE OF HIGH PRESSURE TO CREATE CLOUDS AND SHOWERS
DURING THE AFTERNOON. THERE CONTINUES UNCERTAINTY INTO HOW
SIGNIFICANT THE QPF WILL BE FROM THIS SETUP...AND GUIDANCE HAS
CONTINUED TO BACK OFF ON TOTAL RAINFALL FORECASTS ON FRIDAY. 700MB
OMEGAS ARE FOCUSED JUST OFFSHORE...COINCIDENT WITH THE BEST
PVA...WHILE ISENTROPIC LIFT NEVER BECOMES VERY STRONG OR STEEP. THIS
SUGGESTS THERE MAY BE PERIODS OF VERY LIGHT SHOWERS FRIDAY
AFTN...WITH SOME BETTER RAIN POSSIBLY JUST OFF THE COAST. THIS
MATCHES WELL WITH WPC QPF GRAPHICS FOR FRIDAY...AND AND HESITANT
TO INCREASE POP ANYTHING ABOVE THE INHERITED LOW-CHC. FRIDAY WILL
NOT BE A VERY NICE DAY...AND THE MAV TEMPS HAVE STEADILY WALKED BACK
TOWARDS THE COOLER ECS/MET NUMBERS WHICH SUPPORT THE STRONGER WEDGE.
WITH MID-LEVEL RIDGING AMPLIFYING TO THE EAST PRODUCING INCREASING
SW FLOW ALOFT...STILL BELIEVE THE MET/ECS CAMP IS TOO LOW...BUT WILL
LOWER HIGHS FRIDAY 1-2 DEGREES ACROSS THE BOARD. LIFT AND FORCING
MOVE OFF TO THE NE FRIDAY NIGHT...LEAVING IMPROVING CONDITIONS WITH
LOWS IN THE MID AND UPR 40S.
SATURDAY REMAINS A TRICKIER FORECAST DUE TO THE APPROACH OF A LOW
PRESSURE FROM THE SW AND THE PASSAGE OF A WARM FRONT SATURDAY AFTN.
THE GUIDANCE HAS SPED UP TIMING OF FEATURES EMBEDDED WITHIN STRONG
SW MID-LEVEL FLOW...AND THIS HAS CREATED A CLOUDIER...AND
RAINIER...SATURDAY FORECAST. LOW PRESSURE WILL MOVE NEAR THE SPINE
OF THE APPALACHIANS...BUT ITS WARM FRONT WILL LIFT NORTH ACROSS THE
CWA SATURDAY AFTN. THIS BRINGS RAPIDLY WARMING TEMPERATURES...AND
HIGHS SATURDAY WILL CLIMB WELL INTO THE 60S...AND MAY APPROACH 70 IN
THE EASTERN ZONES DEPENDING ON CLOUD COVER. INCREASING RAIN CHANCES
WILL ALSO ACCOMPANY THIS BOUNDARY...ESPECIALLY SATURDAY NIGHT.
STRONG LLJ NOSES INTO THE REGION AHEAD OF THE COLD FRONT SATURDAY
NIGHT...SO AS NOTED BY PREVIOUS FORECASTER...SHOWERS COULD BECOME
GUSTY LATE IN THE PERIOD...ALTHOUGH INSTABILITY IS LACKING. BY
SUNDAY MORNING THE COLD FRONT ASSOCIATED WITH THE LOW MOVING
NORTHEAST WILL BE ON THE DOORSTEP TO THE CWA. LOWS SATURDAY NIGHT
WILL REMAIN VERY WARM...MID 50S...AS THE WARM SECTOR PERSISTS
LOCALLY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...LINGERING SHOWERS EARLY SUNDAY WILL RAPIDLY
DISSIPATE AS A COLD FRONT CROSSES THE AREA SUNDAY MORNING AND PRECIP
EJECTS OFF TO THE NORTHEAST. THIS IS A TRUE ARCTIC FRONT...AND
STRONG COLD ADVECTION WILL FOLLOW AFTER A WARM FIRST PART OF SUNDAY.
AN ATYPICAL DIURNAL CURVE IS PROBABLE SUNDAY...BUT HIGHS SUNDAY
WILL LIKELY STILL BE ABOUT 10 DEGREES ABOVE NORMAL THANKS TO THE
EARLY MORNING WARM TEMPERATURES.
THEREAFTER...A RETURN TO SEASONABLE OR EVEN BELOW SEASONABLE
TEMPERATURES IS FORECAST. NOT ONLY IS STRONG CAA EXPECTED SUNDAY
NIGHT THROUGH TUESDAY AS 850MB TEMPS FALL TO AROUND -2C...BUT
TELECONNECTIONS SUPPORT AN INTRUSION OF COLD AIR ALONG THE EAST
COAST AS THE AO INDEX PLUMMETS TO SHARPLY NEGATIVE VALUES. ALTHOUGH
THE SUN ANGLE IS SLOWLY INCREASING...INSOLATION WILL NOT BE ABLE TO
OVERCOME THE VERY COLD AIR MASS...SO TEMPS MONDAY THROUGH WEDNESDAY
WILL LIKELY REMAIN BELOW CLIMO...COLDEST WEDNESDAY AS A REINFORCING
SHOT OF COLD AIR /DRY FRONT/ CROSSES THE AREA TUESDAY. THE GFS HAS
THIS FRONT STALLING OFFSHORE WED AS A WAVE OF LOW PRESSURE MOVES UP
ALONG IT...BRINGING SLIGHTLY WARMER TEMPERATURES AND INCREASING RAIN
CHANCES. THIS IS AN INDEPENDENT SOLUTION ATTM HOWEVER...AND WILL OPT
TO SHOW CONTINUED DRY WEATHER WITH BELOW NORMAL TEMPS THROUGH
WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...IFR CONDITIONS WILL BE SETTING UP SHORTLY WITH MAINLY
MVFR/VFR VISIBILITIES. HIGH PRESSURE WILL CONTINUE TO RIDGE JUST
WEST OF THE CWA. THE HRRR MODEL KEEPS ANY PRECIP OFFSHORE AT THIS
TIME...BUT COULD NOT RULE OUT A SPRINKLE AT THE COASTAL TERMINALS
TOWARD MORNING. THURSDAY...A GRADUAL IMPROVEMENT IS FORECAST WITH
CLOUDS SCATTERING IN THE AFTERNOON...ONLY TO RETURN AS STRATUS
SHORTLY AFTER DARK.
EXTENDED OUTLOOK...POTENTIAL FOR MVFR IN SHOWERS FRIDAY
AND EARLY SUNDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM THURSDAY...SEA SPECTRUM STILL A BIT UGLY AND A HAZARD
TO SMALL CRAFT...AS HIGH PRESSURE INLAND AND LOW PRESSURE MOVING
NORTH OUT OF THE BAHAMA CHAIN INTERACT TO PRODUCE NNE WINDS 20-25
KT TODAY INTO TONIGHT. SEA HEIGHTS WILL HOLD AT 4-6 FT AND NEAR 7
FT FAR OUTER WATERS WITH DOMINANT PERIODS BETWEEN 6-8 SECONDS.
SEAS MESSY SINCE SE WAVE ENERGY IS CO-MINGLING WITH THE N WAVES.
NO TSTMS ON THE 0-20 NM WATERS BUT A FEW SHOWERS CAN BE EXPECTED
OUTER WATERS MOVING FROM NE TO SW AT 25 KT. ONLY A SLIGHT EASING
OF WIND EXPECTED TONIGHT AS THE LOW OFFSHORE MOVES FARTHER N. SEAS
WILL NEED TIME TO RECOVER AND ITS POSSIBLE THE ADVISORY COULD BE
EXTENDED THIS EVENING OR EVEN OVERNIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WEDGE OF HIGH PRESSURE WILL SLOWLY WEAKEN
INLAND FROM THE WATERS...CAUSING NE WINDS TO SLOWLY FALL OFF
DURING FRIDAY FROM AROUND 15 KTS EARLY TO 10 KTS LATE. WHILE THIS
WILL PERSIST THE PROLONGED NE FETCH...THE FALLING WINDS WILL HELP
SEAS DROP SLOWLY ON FRIDAY. INITIALLY...3-5 FTERS WILL BE COMMON
WITH A FEW 6 FT SEAS STILL POSSIBLE ESPECIALLY ACROSS NC
WATERS...BUT CONFIDENCE NOT HIGH ENOUGH ATTM TO EXTEND SCA INTO
FRIDAY...AND WILL INSTEAD NOTE HERE AND HWO IT MAY BE REQUIRED.
ANY HEADLINES WILL DROP FRIDAY NIGHT AS SEAS FALL TO 3-4 FT.
ON SATURDAY...A WARM FRONT WILL LIFT NORTH ACROSS THE WATERS CAUSING
WINDS TO SHIFT TO THE SE AND THEN TO THE SW LATE SATURDAY.
ACCOMPANYING THIS WIND SHIFT WILL BE A STEADY INCREASE IN SPEED TO
AROUND 20 KTS LATE IN THE DAY AND AT NIGHT. THIS WILL DRIVE WAVE
HEIGHTS ONCE AGAIN UP TO SCA THRESHOLDS OF 4-7 FT...AND RENEWED
HEADLINES ARE LIKELY LATE IN THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUNDAY BEGINS WITH GUSTY SW WINDS AROUND
20 KTS ONGOING ACROSS THE WATERS AHEAD OF A COLD FRONT WHICH WILL
CROSS OFFSHORE SUNDAY EVENING. THESE ENHANCED WINDS WILL CREATE
SEAS OF 4- 7 FT...AND AN SCA WILL LIKELY BE IN EFFECT TO START THE
PERIOD. WITH THE FROPA WILL BE A RAPID WIND SHIFT TO THE NW BUT
WITH SPEEDS REMAINING AT 15-20 KTS SUNDAY NIGHT...BEFORE SLOWLY
FALLING TO AROUND 10 KTS MONDAY WITH A STILL NW DIRECTION.
HEADLINES WILL DROP QUICKLY BEHIND THE FRONT AS THE NW WINDS PUSH
THE HIGHEST SEAS OUT OF THE LOCAL WATERS...AND WAVE HEIGHTS ARE
EXPECTED TO FALL TO 3-5 FT SUNDAY NIGHT...AND THEN FURTHER TO 2-3
FT DURING MONDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MJC
MARINE...MJC/JDW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
405 AM EST THU JAN 07 2016
.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO GRADUALLY WEAKEN
AS IT RETREATS TO THE NORTHEAST THROUGH EARLY THURSDAY.
MEANWHILE...A SERIES OF UPPER DISTURBANCES WILL BEGIN TO CROSS THE
REGION IN SOUTHWESTERLY FLOW ALOFT LATE THIS WEEK...LEADING TO
UNSETTLED WEATHER FOR THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM THURSDAY..
HIGH PRESSURE...MAINTAINED BY SHORTWAVE RIDGING ALOFT...CONTINUES TO
EXTEND FROM THE MID-ATLANTIC STATES THROUGH THE NC PIEDMONT...WITH A
FAIRLY PRONOUNCED INVERTED TROUGH OFFSHORE. ALOFT...THE FLOW IS
GENERALLY WEAK SOUTHWESTERLY WITH DISTURBANCES OFF THE GA/FL COAST
AND OVER THE SOUTHERN PLAINS. A SHALLOW LAYER OF MOISTURE IN
SOUTHEASTERLY FLOW ATOP THE SURFACE RIDGE HAS LED TO WIDESPREAD
STRATUS AND A SMALL AREA OF RECENTLY EXPANDING DRIZZLE JUST EAST OF
THE TRIANGLE AREA...WHICH ITSELF APPEARS TO BE FOCUSED WITHIN THE
REGION OF STRONGEST 925MB WARM ADVECTION. THE MOISTURE IS
SHALLOW...THOUGH SLIGHTLY DEEPER TOWARD THE COAST...AND LUCKILY
DEWPOINTS HAVE RECOVERED INTO THE 30S EVERYWHERE EXCEPT FOR THE FAR
WESTERN PIEDMONT. THIS POORLY RESOLVED AREA OF DRIZZLE SHOULD SHIFT
NORTH-NORTHWESTWARD THIS MORNING AND NOT CAUSE ANY PROBLEMS.
OTHERWISE TODAYS FORECAST CHALLENGE IS WHETHER OR NOT THE STRATUS
WILL PERSIST THROUGH THE DAY. THE 925NMB FLOW SHOULD BACK TO MORE
NORTHEASTERLY THIS MORNING IN RESPONSE TO THE AREA OF LOW PRESSURE
DEVELOPING WELL OFF THE SOUTHEAST COAST...AND THUS THE WARM
ADVECTION WILL DIMINISH. THE NAM AND GFS MAINTAIN THE STRATUS
THROUGH THIS AFTERNOON ON THE EAST WHERE THE MOISTURE IS ALREADY
DEEPER...WHILE BREAKING THE WESTERN PIEDMONT OUT. RAP RUNS HAVE
TENDED TO SCATTER OUT THE ENTIRE AREA. WILL TREND THE FORECAST
TOWARD A LITTLE LESS CLOUD COVER BY THIS AFTERNOON...ADMITTEDLY WITH
LOW CONFIDENCE. HIGHS MAY FEATURE A MORE EVEN DISTRIBUTION THAT
USUAL...WITH MID AND UPPER 40S FOR MOST AREAS. HOWEVER...IF CLOUDS
DO SCATTER THEN LOWER 50S ARE POSSIBLY FOR THE EASTERN HALF OF THE
AREA.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 340 AM THURSDAY...
WHAT MOISTURE IS STILL AROUND THIS EVENING SHOULD LEAD TO
REDEVELOPING STRATUS BENEATH THE INVERSION ALOFT TONIGHT.
MEANWHILE... THE AFOREMENTIONED UPPER DISTURBANCE OVER THE SOUTHERN
PLAINS WILL LIFT TOWARD THE UPPER MIDWEST TONIGHT AND FRIDAY..WHILE
THE EASTERN EXTENT OF THE TROUGH AXIS AND DCVA LIFT ACROSS THE
SOUTHEAST US. THE LEFT EXIT REGION OF THE STJ WILL PROVIDE SOME
UPPER DIVERGENCE...BUT LOW-LEVEL FORCING IS LACKING WITH THE COASTAL
TROUGH STAYING PUT AND PRETTY WEAK LOW-LEVEL FLOW/ADVECTION. THE
TREND IN THE MODELS TOWARD A DRIER FORECAST HAS STABILIZED AND THE
NAM/GFS/ECMWF ALL INDICATED JUST SOME VERY LIGHT SHOWERS DURING THE
DAY ON FRIDAY. WILL MAINTAIN A SLIGHT CHANCE TO CHANCE POP AFTER
12Z FRIDAY AND NO POPS FRIDAY NIGHT AHEAD OF THE NEXT SYSTEM TO
IMPACT THE AREA ON SATURDAY.
LOWS TONIGHT WILL DEPEND HOW MUCH WE SCATTER OUT TODAY AND HOW
QUICKLY CLOUDS INCREASE OVERNIGHT AHEAD OF THE APPROACHING TROUGH.
GIVEN NO CHANGE IN THE AIR MASS AND POTENTIAL FOR OVERCAST
AGAIN...LOWS SHOULD BE SIMILAR TO THIS MORNING...34-42 NW TO SE.
HIGHS FRIDAY COULD BE LOWER WITH MORE PRECIP...BUT WILL STILL
FEATURE A CAD-LIKE RANGE GIVEN THE SURFACE HIGH AND DIABATIC EFFECTS
OF THE LOW CLOUDS...MID 40S NW TO MID 50S SOUTHEAST. AND FINALLY
FRIDAY NIGHT LOWS WILL BE A TAD MILDER IN THE 40-48 RANGE AS
DEWPOINTS CREEP UP INTO THE LOWER 40S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 400 AM THURSDAY...
FORECAST CONFIDENCE CONTINUES TO INCREASE WITH RESPECT TO THE NEXT
RELATIVELY SIGNIFICANT SYSTEM EXPECTED TO AFFECT CENTRAL NC WITH A
HIGH PROBABILITY OF RAIN...AND ASSOCIATED WEAK HYBRID COLD AIR
DAMMING...EARLY THIS WEEKEND. IN FACT...THE MODELS ARE IN GOOD
OVERALL AGREEMENT REGARDING THE SYNOPTIC PATTERN...ONE CHARACTERIZED
BY A PRIMARY SURFACE LOW TRACK INTO THE GREAT LAKES AND SECONDARY
DEVELOPMENT ALONG A RETREATING COASTAL FRONT FROM THE GULF COAST TO
THE MIDDLE ATLANTIC PIEDMONT SAT-SAT NIGHT. THE PASSAGE OF THE
SECONDARY/TRIPLE POINT LOW AND ASSOCIATED LOW LEVEL THETA-E
ADVECTION MAY ALSO SUPPORT A FEW ELEVATED STORMS DURING THE
AFTERNOON AND EVENING SAT. THE EARLIER INDICATED FASTER TREND WITH
THIS SYSTEM REMAINS...WITH MOST OR ALL OF THE SHOWERS EAST AND
NORTHEAST OF CENTRAL NC BY DAYBREAK SUNDAY.
OTHERWISE...THE PATTERN FOR EARLY TO MID NEXT WEEK APPEARS TO BE A
RELATIVELY COOL AND DRY ONE...AS A BROAD TROUGH BECOMES ESTABLISHED
ACROSS THE EASTERN TWO THIRDS OF THE COUNTRY. THE ONE EXCEPTION WILL
BE A BRIEF PERIOD OF LIFT AS A SHORTWAVE TROUGH AND ACCOMPANYING JET
STREAK IN NW FLOW ALOFT AMPLIFY ACROSS THE APPALACHIANS LATE TUE
NIGHT-EARLY WED...AT WHICH TIME A FEW FLURRIES OR SPRINKLES WOULD BE
POSSIBLE IN AN OTHERWISE DRY REGIME BETWEEN UPSLOPE APPALACHIAN
PRECIPITATION AND OFFSHORE LOW PRESSURE...THE LATTER OF WHICH WOULD
BE SUPPORTED ALOFT BY THE AFOREMENTIONED SHORTWAVE TROUGH IN NW FLOW
ALOFT...WHICH MAY GRAZE COASTAL AREAS OF THE NORTHERN MIDDLE
ATLANTIC STATES AND/OR NEW ENGLAND ON WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 100 AM THURSDAY...
SOUTH-SOUTHEASTERLY FLOW JUST ABOVE THE SURFACE HAS ADVECTED A
SHALLOW LAYER OF MOISTURE ACROSS CENTRAL NC...WITH MVFR CEILINGS NOW
BLANKETING THE AREA. THE MOISTURE IS A LITTLE DEEPER OVER THE
COASTAL PLAIN...WHERE A PERIOD OF IFR CEILINGS IS POSSIBLE PRIOR TO
12Z...AND THEN MVFR CEILINGS ARE MOST LIKELY TO PERSIST THROUGH THE
DAY. TO THE WEST AT KGSO AND KINT...WHERE THE MOISTURE IS MUCH MORE
SHALLOW...MODELS SHOW A BETTER CHANCE OF THE CEILINGS BREAKING BY
MIDDAY. MODELS HAVE STRUGGLED WITH THIS SHALLOW MOISTURE..SO
CONFIDENCE IS BELOW AVERAGE AT THIS POINT.
OUTLOOK...A COUPLE OF LOW PRESSURE SYSTEMS WILL IMPACT THE REGION
THROUGH THE WEEKEND. DESPITE VERY LITTLE RAIN WILL THE FIRST
SYSTEM ON FRIDAY...MVFR/IFR CEILINGS ARE EXPECTED...CONTINUING
THROUGH SATURDAY AS A STRONGER SYSTEM BRING WIDESPREAD RAIN.
IMPROVING CONDITIONS ARE EXPECTED BY SUNDAY AND MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...22
SHORT TERM...22
LONG TERM...2
AVIATION...22
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
345 AM EST THU JAN 7 2016
.SYNOPSIS...
HIGH PRESSURE WILL PUSH DOWN THE COAST THROUGH FRIDAY WHILE A
COASTAL FRONT LINGERS OFFSHORE. A WEAK MID LEVEL IMPULSE WILL
BRING A CHANCE FOR SHOWERS ON FRIDAY. A WARM FRONT WILL LIFT
ACROSS THE AREA SATURDAY BRINGING GOOD CHANCES FOR RAIN INTO
SUNDAY ALONG WITH MUCH WARMER TEMPERATURES. MUCH COLDER
TEMPERATURES WILL FOLLOW A COLD FRONT EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...WEAKENING HIGH PRESSURE WEDGE THE PRIMARY
FEATURE TODAY AND TONIGHT ACCOMPANIED BY MULTIPLE CLOUD LAYERING.
SOUTHERLY WINDS ABOVE 500 MB WILL DIRECT A COAT OF CIRRUS THROUGH
SC AND THE DEEPER INTERIOR OF SE NC...WITH A SMATTERING OF LOW
CLOUDS TRAPPED BENEATH A NOTABLE INVERSION TODAY. A TROUBLESOME
SKY FORECAST AS VARIABILITY IS EXPECTED NEAR THE COAST WITH MORE
STUBBORN COVERAGE LIKELY INLAND. THIS COMPLICATES MAXIMUM TEMPS
BUT MIDDLE 50S WELL INLAND TO NEAR 60 AT THE COAST ANTICIPATED.
STEERING FLOW WILL KEEP OCEAN SHOWERS MAINLY AT SEA AND THERE IS
LITTLE FORCING OVER LAND TO TRIGGER PCPN TODAY. AN EXCEPTIONALLY
DRY MID-LAYER WILL HOLD ITS GROUND TODAY. TONIGHT SHORT-WAVE
IMPULSING AND WEAK ISENTROPIC OMEGA FROM THE SW WILL ARRIVE IN
THE PRE-DAWN HOURS AND A SLIGHT CHANCE OF RAIN FOR SC INTO DAWN.
MINIMUMS LOW/MID 40S INLAND...AND UPPER 40S TO NEAR 50 COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...MID-LEVEL IMPULSE MOVING OVERHEAD FRIDAY
WILL COMBINE WITH INCREASING ISENTROPIC LIFT ALONG THE 300K SURFACE
ATOP A SURFACE WEDGE OF HIGH PRESSURE TO CREATE CLOUDS AND SHOWERS
DURING THE AFTERNOON. THERE CONTINUES UNCERTAINTY INTO HOW
SIGNIFICANT THE QPF WILL BE FROM THIS SETUP...AND GUIDANCE HAS
CONTINUED TO BACK OFF ON TOTAL RAINFALL FORECASTS ON FRIDAY. 700MB
OMEGAS ARE FOCUSED JUST OFFSHORE...COINCIDENT WITH THE BEST
PVA...WHILE ISENTROPIC LIFT NEVER BECOMES VERY STRONG OR STEEP. THIS
SUGGESTS THERE MAY BE PERIODS OF VERY LIGHT SHOWERS FRIDAY
AFTN...WITH SOME BETTER RAIN POSSIBLY JUST OFF THE COAST. THIS
MATCHES WELL WITH WPC QPF GRAPHICS FOR FRIDAY...AND AND HESITANT
TO INCREASE POP ANYTHING ABOVE THE INHERITED LOW-CHC. FRIDAY WILL
NOT BE A VERY NICE DAY...AND THE MAV TEMPS HAVE STEADILY WALKED BACK
TOWARDS THE COOLER ECS/MET NUMBERS WHICH SUPPORT THE STRONGER WEDGE.
WITH MID-LEVEL RIDGING AMPLIFYING TO THE EAST PRODUCING INCREASING
SW FLOW ALOFT...STILL BELIEVE THE MET/ECS CAMP IS TOO LOW...BUT WILL
LOWER HIGHS FRIDAY 1-2 DEGREES ACROSS THE BOARD. LIFT AND FORCING
MOVE OFF TO THE NE FRIDAY NIGHT...LEAVING IMPROVING CONDITIONS WITH
LOWS IN THE MID AND UPR 40S.
SATURDAY REMAINS A TRICKIER FORECAST DUE TO THE APPROACH OF A LOW
PRESSURE FROM THE SW AND THE PASSAGE OF A WARM FRONT SATURDAY AFTN.
THE GUIDANCE HAS SPED UP TIMING OF FEATURES EMBEDDED WITHIN STRONG
SW MID-LEVEL FLOW...AND THIS HAS CREATED A CLOUDIER...AND
RAINIER...SATURDAY FORECAST. LOW PRESSURE WILL MOVE NEAR THE SPINE
OF THE APPALACHIANS...BUT ITS WARM FRONT WILL LIFT NORTH ACROSS THE
CWA SATURDAY AFTN. THIS BRINGS RAPIDLY WARMING TEMPERATURES...AND
HIGHS SATURDAY WILL CLIMB WELL INTO THE 60S...AND MAY APPROACH 70 IN
THE EASTERN ZONES DEPENDING ON CLOUD COVER. INCREASING RAIN CHANCES
WILL ALSO ACCOMPANY THIS BOUNDARY...ESPECIALLY SATURDAY NIGHT.
STRONG LLJ NOSES INTO THE REGION AHEAD OF THE COLD FRONT SATURDAY
NIGHT...SO AS NOTED BY PREVIOUS FORECASTER...SHOWERS COULD BECOME
GUSTY LATE IN THE PERIOD...ALTHOUGH INSTABILITY IS LACKING. BY
SUNDAY MORNING THE COLD FRONT ASSOCIATED WITH THE LOW MOVING
NORTHEAST WILL BE ON THE DOORSTEP TO THE CWA. LOWS SATURDAY NIGHT
WILL REMAIN VERY WARM...MID 50S...AS THE WARM SECTOR PERSISTS
LOCALLY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...LINGERING SHOWERS EARLY SUNDAY WILL RAPIDLY
DISSIPATE AS A COLD FRONT CROSSES THE AREA SUNDAY MORNING AND PRECIP
EJECTS OFF TO THE NORTHEAST. THIS IS A TRUE ARCTIC FRONT...AND
STRONG COLD ADVECTION WILL FOLLOW AFTER A WARM FIRST PART OF SUNDAY.
AN ATYPICAL DIURNAL CURVE IS PROBABLE SUNDAY...BUT HIGHS SUNDAY
WILL LIKELY STILL BE ABOUT 10 DEGREES ABOVE NORMAL THANKS TO THE
EARLY MORNING WARM TEMPERATURES.
THEREAFTER...A RETURN TO SEASONABLE OR EVEN BELOW SEASONABLE
TEMPERATURES IS FORECAST. NOT ONLY IS STRONG CAA EXPECTED SUNDAY
NIGHT THROUGH TUESDAY AS 850MB TEMPS FALL TO AROUND -2C...BUT
TELECONNECTIONS SUPPORT AN INTRUSION OF COLD AIR ALONG THE EAST
COAST AS THE AO INDEX PLUMMETS TO SHARPLY NEGATIVE VALUES. ALTHOUGH
THE SUN ANGLE IS SLOWLY INCREASING...INSOLATION WILL NOT BE ABLE TO
OVERCOME THE VERY COLD AIR MASS...SO TEMPS MONDAY THROUGH WEDNESDAY
WILL LIKELY REMAIN BELOW CLIMO...COLDEST WEDNESDAY AS A REINFORCING
SHOT OF COLD AIR /DRY FRONT/ CROSSES THE AREA TUESDAY. THE GFS HAS
THIS FRONT STALLING OFFSHORE WED AS A WAVE OF LOW PRESSURE MOVES UP
ALONG IT...BRINGING SLIGHTLY WARMER TEMPERATURES AND INCREASING RAIN
CHANCES. THIS IS AN INDEPENDENT SOLUTION ATTM HOWEVER...AND WILL OPT
TO SHOW CONTINUED DRY WEATHER WITH BELOW NORMAL TEMPS THROUGH
WEDNESDAY.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...IFR CONDITIONS WILL BE SETTING UP SHORTLY WITH MAINLY
MVFR/VFR VISIBILITIES. HIGH PRESSURE WILL CONTINUE TO RIDGE JUST
WEST OF THE CWA. THE HRRR MODEL KEEPS ANY PRECIP OFFSHORE AT THIS
TIME...BUT COULD NOT RULE OUT A SPRINKLE AT THE COASTAL TERMINALS
TOWARD MORNING. THURSDAY...A GRADUAL IMPROVEMENT IS FORECAST WITH
CLOUDS SCATTERING IN THE AFTERNOON...ONLY TO RETURN AS STRATUS
SHORTLY AFTER DARK.
EXTENDED OUTLOOK...POTENTIAL FOR MVFR IN SHOWERS FRIDAY
AND EARLY SUNDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...SEA SPECTRUM STILL A BIT UGLY AND A HAZARD
TO SMALL CRAFT...AS HIGH PRESSURE INLAND AND LOW PRESSURE MOVING
NORTH OUT OF THE BAHAMA CHAIN INTERACT TO PRODUCE NNE WINDS 20-25
KT TODAY INTO TONIGHT. SEA HEIGHTS WILL HOLD AT 4-6 FT AND NEAR 7
FT FAR OUTER WATERS WITH DOMINANT PERIODS BETWEEN 6-8 SECONDS.
SEAS MESSY SINCE SE WAVE ENERGY IS CO-MINGLING WITH THE N WAVES.
NO TSTMS ON THE 0-20 NM WATERS BUT A FEW SHOWERS CAN BE EXPECTED
OUTER WATERS MOVING FROM NE TO SW AT 25 KT. ONLY A SLIGHT EASING
OF WIND EXPECTED TONIGHT AS THE LOW OFFSHORE MOVES FARTHER N. SEAS
WILL NEED TIME TO RECOVER AND ITS POSSIBLE THE ADVISORY COULD BE
EXTENDED THIS EVENING OR EVEN OVERNIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WEDGE OF HIGH PRESSURE WILL SLOWLY WEAKEN
INLAND FROM THE WATERS...CAUSING NE WINDS TO SLOWLY FALL OFF
DURING FRIDAY FROM AROUND 15 KTS EARLY TO 10 KTS LATE. WHILE THIS
WILL PERSIST THE PROLONGED NE FETCH...THE FALLING WINDS WILL HELP
SEAS DROP SLOWLY ON FRIDAY. INITIALLY...3-5 FTERS WILL BE COMMON
WITH A FEW 6 FT SEAS STILL POSSIBLE ESPECIALLY ACROSS NC
WATERS...BUT CONFIDENCE NOT HIGH ENOUGH ATTM TO EXTEND SCA INTO
FRIDAY...AND WILL INSTEAD NOTE HERE AND HWO IT MAY BE REQUIRED.
ANY HEADLINES WILL DROP FRIDAY NIGHT AS SEAS FALL TO 3-4 FT.
ON SATURDAY...A WARM FRONT WILL LIFT NORTH ACROSS THE WATERS CAUSING
WINDS TO SHIFT TO THE SE AND THEN TO THE SW LATE SATURDAY.
ACCOMPANYING THIS WIND SHIFT WILL BE A STEADY INCREASE IN SPEED TO
AROUND 20 KTS LATE IN THE DAY AND AT NIGHT. THIS WILL DRIVE WAVE
HEIGHTS ONCE AGAIN UP TO SCA THRESHOLDS OF 4-7 FT...AND RENEWED
HEADLINES ARE LIKELY LATE IN THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUNDAY BEGINS WITH GUSTY SW WINDS AROUND
20 KTS ONGOING ACROSS THE WATERS AHEAD OF A COLD FRONT WHICH WILL
CROSS OFFSHORE SUNDAY EVENING. THESE ENHANCED WINDS WILL CREATE
SEAS OF 4- 7 FT...AND AN SCA WILL LIKELY BE IN EFFECT TO START THE
PERIOD. WITH THE FROPA WILL BE A RAPID WIND SHIFT TO THE NW BUT
WITH SPEEDS REMAINING AT 15-20 KTS SUNDAY NIGHT...BEFORE SLOWLY
FALLING TO AROUND 10 KTS MONDAY WITH A STILL NW DIRECTION.
HEADLINES WILL DROP QUICKLY BEHIND THE FRONT AS THE NW WINDS PUSH
THE HIGHEST SEAS OUT OF THE LOCAL WATERS...AND WAVE HEIGHTS ARE
EXPECTED TO FALL TO 3-5 FT SUNDAY NIGHT...AND THEN FURTHER TO 2-3
FT DURING MONDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MJC
MARINE...MJC/JDW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
340 AM EST THU JAN 07 2016
.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO GRADUALLY WEAKEN
AS IT RETREATS TO THE NORTHEAST THROUGH EARLY THURSDAY.
MEANWHILE...A SERIES OF UPPER DISTURBANCES WILL BEGIN TO CROSS THE
REGION IN SOUTHWESTERLY FLOW ALOFT LATE THIS WEEK...LEADING TO
UNSETTLED WEATHER FOR THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM THURSDAY..
HIGH PRESSURE...MAINTAINED BY SHORTWAVE RIDGING ALOFT...CONTINUES TO
EXTEND FROM THE MID-ATLANTIC STATES THROUGH THE NC PIEDMONT...WITH A
FAIRLY PRONOUNCED INVERTED TROUGH OFFSHORE. ALOFT...THE FLOW IS
GENERALLY WEAK SOUTHWESTERLY WITH DISTURBANCES OFF THE GA/FL COAST
AND OVER THE SOUTHERN PLAINS. A SHALLOW LAYER OF MOISTURE IN
SOUTHEASTERLY FLOW ATOP THE SURFACE RIDGE HAS LED TO WIDESPREAD
STRATUS AND A SMALL AREA OF RECENTLY EXPANDING DRIZZLE JUST EAST OF
THE TRIANGLE AREA...WHICH ITSELF APPEARS TO BE FOCUSED WITHIN THE
REGION OF STRONGEST 925MB WARM ADVECTION. THE MOISTURE IS
SHALLOW...THOUGH SLIGHTLY DEEPER TOWARD THE COAST...AND LUCKILY
DEWPOINTS HAVE RECOVERED INTO THE 30S EVERYWHERE EXCEPT FOR THE FAR
WESTERN PIEDMONT. THIS POORLY RESOLVED AREA OF DRIZZLE SHOULD SHIFT
NORTH-NORTHWESTWARD THIS MORNING AND NOT CAUSE ANY PROBLEMS.
OTHERWISE TODAYS FORECAST CHALLENGE IS WHETHER OR NOT THE STRATUS
WILL PERSIST THROUGH THE DAY. THE 925NMB FLOW SHOULD BACK TO MORE
NORTHEASTERLY THIS MORNING IN RESPONSE TO THE AREA OF LOW PRESSURE
DEVELOPING WELL OFF THE SOUTHEAST COAST...AND THUS THE WARM
ADVECTION WILL DIMINISH. THE NAM AND GFS MAINTAIN THE STRATUS
THROUGH THIS AFTERNOON ON THE EAST WHERE THE MOISTURE IS ALREADY
DEEPER...WHILE BREAKING THE WESTERN PIEDMONT OUT. RAP RUNS HAVE
TENDED TO SCATTER OUT THE ENTIRE AREA. WILL TREND THE FORECAST
TOWARD A LITTLE LESS CLOUD COVER BY THIS AFTERNOON...ADMITTEDLY WITH
LOW CONFIDENCE. HIGHS MAY FEATURE A MORE EVEN DISTRIBUTION THAT
USUAL...WITH MID AND UPPER 40S FOR MOST AREAS. HOWEVER...IF CLOUDS
DO SCATTER THEN LOWER 50S ARE POSSIBLY FOR THE EASTERN HALF OF THE
AREA.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 340 AM THURSDAY...
WHAT MOISTURE IS STILL AROUND THIS EVENING SHOULD LEAD TO
REDEVELOPING STRATUS BENEATH THE INVERSION ALOFT TONIGHT.
MEANWHILE... THE AFOREMENTIONED UPPER DISTURBANCE OVER THE SOUTHERN
PLAINS WILL LIFT TOWARD THE UPPER MIDWEST TONIGHT AND FRIDAY..WHILE
THE EASTERN EXTENT OF THE TROUGH AXIS AND DCVA LIFT ACROSS THE
SOUTHEAST US. THE LEFT EXIT REGION OF THE STJ WILL PROVIDE SOME
UPPER DIVERGENCE...BUT LOW-LEVEL FORCING IS LACKING WITH THE COASTAL
TROUGH STAYING PUT AND PRETTY WEAK LOW-LEVEL FLOW/ADVECTION. THE
TREND IN THE MODELS TOWARD A DRIER FORECAST HAS STABILIZED AND THE
NAM/GFS/ECMWF ALL INDICATED JUST SOME VERY LIGHT SHOWERS DURING THE
DAY ON FRIDAY. WILL MAINTAIN A SLIGHT CHANCE TO CHANCE POP AFTER
12Z FRIDAY AND NO POPS FRIDAY NIGHT AHEAD OF THE NEXT SYSTEM TO
IMPACT THE AREA ON SATURDAY.
LOWS TONIGHT WILL DEPEND HOW MUCH WE SCATTER OUT TODAY AND HOW
QUICKLY CLOUDS INCREASE OVERNIGHT AHEAD OF THE APPROACHING TROUGH.
GIVEN NO CHANGE IN THE AIR MASS AND POTENTIAL FOR OVERCAST
AGAIN...LOWS SHOULD BE SIMILAR TO THIS MORNING...34-42 NW TO SE.
HIGHS FRIDAY COULD BE LOWER WITH MORE PRECIP...BUT WILL STILL
FEATURE A CAD-LIKE RANGE GIVEN THE SURFACE HIGH AND DIABATIC EFFECTS
OF THE LOW CLOUDS...MID 40S NW TO MID 50S SOUTHEAST. AND FINALLY
FRIDAY NIGHT LOWS WILL BE A TAD MILDER IN THE 40-48 RANGE AS
DEWPOINTS CREEP UP INTO THE LOWER 40S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 340 PM WEDNESDAY...
ANOTHER TREND IN THE MODELS IS A FASTER ARRIVAL OF THE NEXT S/W AND
IT`S ASSOC WEATHER...THE S/W THAT`S CURRENTLY POSITIONED JUST
OFFSHORE OF THE PAC NW REGION. RAIN WITH THIS SYSTEM IS NOW PROGGED
BY SAT MORNING PER ECMWF...OR BY SAT EVENING PER GFS. SINCE THE
TREND HAS BEEN EARLIER...AT THIS POINT PREFER THE EARLIER ECWMF
SOLUTION AND HAVE ADJUSTED POPS FOR THAT TIME ACCORDINGLY. WITH THAT
TREND...NOW IT APPEARS THAT SUNDAY (AFTER SUNRISE) WILL BE DRY ON
THE BACK SIDE OF THE AFOREMENTIONED S/W. ALSO IN THE WAKE OF THE
WAVE CAA WILL ENSUE...WITH FORECAST LOW LEVEL THICKNESSES BOTTOMING
OUT BY MONDAY MORNING AND REMAINING IN THE 1290-1305M RANGE THROUGH
MIDWEEK...WHICH IS ABOUT NORMAL FOR THIS TIME OF YEAR AND TYPICALLY
RESULTS IN HIGHS IN THE M-U 40S AND LOWS AROUND 30.
OTHERWISE...YET ANOTHER MODEL CHANGE IS THAT THE LATEST GFS BRINGS
MOISTURE AND SOUTHERN STREAM S/W ENERGY UP ACROSS THE COASTAL SE
STATES...WITH A RESULTANT COASTAL LOW PROGGED TO LIFT NE ALONG THE
GULF STREAM ON TUESDAY. THE 12Z ECMWF...SIMILAR TO ITS PREV RUNS...
STILL KEEPS THE S/W ENERGY FLATTER AND FARTHER SUPPRESSED TO THE
SOUTH...WITH THE END RESULT BEING A CONTINUATION OF DRY SEASONABLE
WEATHER FOR THE MON-WED TIME FRAME. THE VAST MAJORITY OF THE ECMWF
ENSEMBLE MEMBERS SUPPORT THE DRY OPERATIONAL SOLUTION...AND IT SEEMS
WISE TO NOT JUMP ON ONE RUN OF THE GFS...WHICH HAS BEEN A BIG CHANGE
FROM PREV RUNS...SO FOR NOW WILL KEEP THE MON-WED TIME FRAME DRY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 100 AM THURSDAY...
SOUTH-SOUTHEASTERLY FLOW JUST ABOVE THE SURFACE HAS ADVECTED A
SHALLOW LAYER OF MOISTURE ACROSS CENTRAL NC...WITH MVFR CEILINGS NOW
BLANKETING THE AREA. THE MOISTURE IS A LITTLE DEEPER OVER THE
COASTAL PLAIN...WHERE A PERIOD OF IFR CEILINGS IS POSSIBLE PRIOR TO
12Z...AND THEN MVFR CEILINGS ARE MOST LIKELY TO PERSIST THROUGH THE
DAY. TO THE WEST AT KGSO AND KINT...WHERE THE MOISTURE IS MUCH MORE
SHALLOW...MODELS SHOW A BETTER CHANCE OF THE CEILINGS BREAKING BY
MIDDAY. MODELS HAVE STRUGGLED WITH THIS SHALLOW MOISTURE..SO
CONFIDENCE IS BELOW AVERAGE AT THIS POINT.
OUTLOOK...A COUPLE OF LOW PRESSURE SYSTEMS WILL IMPACT THE REGION
THROUGH THE WEEKEND. DESPITE VERY LITTLE RAIN WILL THE FIRST
SYSTEM ON FRIDAY...MVFR/IFR CEILINGS ARE EXPECTED...CONTINUING
THROUGH SATURDAY AS A STRONGER SYSTEM BRING WIDESPREAD RAIN.
IMPROVING CONDITIONS ARE EXPECTED BY SUNDAY AND MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...22
SHORT TERM...22
LONG TERM...RAH
AVIATION...22
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1250 AM EST THU JAN 7 2016
.SYNOPSIS...
HIGH PRESSURE WILL PUSH DOWN THE COAST THROUGH FRIDAY WHILE A
COASTAL FRONT LINGERS OFFSHORE. A GRADUAL WARMING TREND WILL BEGIN
FRIDAY AS THE WEDGE OF HIGH PRESSURE BREAKS DOWN...BUT THIS WILL
BRING A CHANCE FOR RAIN ON FRIDAY. A WARM FRONT WILL LIFT NORTH
ACROSS THE AREA BRINGING A BETTER CHANCE FOR SHOWERS DURING THE
WEEKEND. MUCH COOLER TEMPERATURES WILL FOLLOW A COLD FRONT EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1250 AM THURSDAY...ADDED MENTION OF PATCHY DRIZZLE AS IT IS
POSSIBLE THAT WEAK ISENTROPIC LIFT OVER SHALLOW COOL LAYER COULD
WRING OUT SOME VERY LIGHT PRECIPITATION AS CEILINGS LOWER.
INCLUDED MENTION OF PATCHY DRIZZLE THROUGHOUT GIVEN LATEST MODEL
SOUNDINGS DO SUPPORT A PRONOUNCED NEAR SURFACE INVERSION WITH ONLY
THE LOWEST 5 TO 8 HUNDRED FT DRYING OUT. KEPT POPS BELOW THRESHOLD
AS MEASURABLE RAINFALL IS NOT EXPECTED TO MAKE IT ONSHORE.
LIGHT RAIN CONTINUED TO SLIDE DOWN THE CAROLINA AND SOUTHEAST
COAST ALONG A NEARLY STATIONARY FRONT...DEMARCATING A ZONE OF
LOW-LEVEL CONVERGENCE. THIS FRONT IS NOT EXPECTED TO MOVE THAT
MUCH OVERNIGHT AND CONSEQUENTLY...THE RAIN SHOULD REMAIN OFFSHORE.
STRENGTHENING LOW PRESSURE...ABOUT 500 MILES SSE OF THE MOUTH OF
THE CAPE FEAR RIVER...IS EXPECTED TO MOVE NNE...PASSING WELL
OFFSHORE OF THE CAROLINAS THROUGH FRIDAY.
A COASTAL FRONT CONTINUES TO SHARPEN OFFSHORE AS A WEDGE OF HIGH
PRESSURE REMAINS IN PLACE ACROSS THE WESTERN CAROLINAS. THE
MOISTURE PROFILES SHOW VERY DRY AIR ABOVE 7-9 KFT AND DRY AIR
NEAR THE SURFACE. PRECIPITABLE WATER VALUES ONLY RISE MARGINALLY
THROUGH THU MORNING. ALTHOUGH SPOTTY DRIZZLE CAN NOT BE RULED
OUT...MEASURABLE RAINFALL SHOULD BE HARD TO COME BY AND SO HAVE
KEPT POPS NEAR OR BELOW THRESHOLD AT THE COAST AND MUCH LOWER AS
YOU PROGRESS INLAND.
AN ABUNDANCE OF CLOUDS AND AN ONSHORE FLOW SHOULD KEEP TEMPS MUCH
HIGHER THAN IN RECENT NIGHTS. WE DO NOT EXPECT LOW TEMPS BELOW
THE UPPER 30S AND LOWER 40S. A FEW SPOTS ALONG AND WEST OF
INTERSTATE 95 MAY DROP TO THE MID 30S. ALL AREAS WILL REMAIN ABOVE
FREEZING TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...MID LEVEL RIDGING WILL DEVELOP INTO
BASICALLY A SOUTHWEST FLOW THROUGH THE PERIOD. THERE IS ONE
SUBTLE SHORTWAVE MOVING ACROSS LATE FRIDAY WHICH MAY KICK OFF A
FEW SHOWERS. AT THE SURFACE HIGH PRESSURE WILL CONTINUE TO WEDGE
DOWN INTO THE AREA THROUGH THE PERIOD ALTHOUGH THE AIRMASS WILL
SLOWLY MODIFY. I HAVE WALKED BACK POPS ESSENTIALLY THROUGH THE
PERIOD. ANY ACTIVITY SNEAKING IN FROM OFFSHORE WITH THE COASTAL
FRONT SEEMS A STRETCH. THE FORCING AND MOISTURE WITH THE SHORTWAVE
FRIDAY LOOK RATHER TEPID AS WELL. TEMPERATURE GUIDANCE IN TWO
DISTINCT CAMPS WITH THE MET NUMBERS MUCH COOLER ACROSS THE BOARD.
LEANED HEAVILY TOWARD THE WARMER MAV ALTHOUGH THE SLOW MODERATION
TODAY GIVES ME A LITTLE HESITATION.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...WE WILL HAVE TWO MAIN AIRMASSES TO CONTEND
WITH THROUGH THE LONG TERM. THE FIRST WILL BE WARM AND MOISTURE-
LADEN ON SATURDAY ESPECIALLY FOLLOWING THE AFTERNOON PASSAGE OF A
WARM FRONT AHEAD OF DEVELOPING LOW EAST OF THE SOUTHERN FRINGE OF
THE APPALACHIANS. DESPITE WIDESPREAD CLOUD COVER AND PERHAPS
INTERMITTENT LIGHT RAIN SATURDAY WILL WARM UP INTO THE 60S. LOW
LEVEL JET AND WARM TONGUE RUN UP THE COAST SATURDAY NIGHT FOR NOT
ONLY A POSSIBLE INCREASE IN RAIN CHANCES BUT PERHAPS ALSO A FEW
STRONG GUSTY SHOWERS. ASCENT MAY BE TOO WEAK/SHALLOW FOR DEEP
CONVECTION/LIGHTNING FOR MUCH OF THE NIGHT SAVE FOR MAYBE ACTUAL
FROPA IN THE 10-12Z SUNDAY TIME FRAME . STRONG CAA ON SUNDAY
POSSIBLY MAKING FOR A NON-DIURNAL CURVE AND THUS NAILING THE ACTUAL
HIGH TEMPERATURE A BIT TRICKY. THE REST OF THE LONG TERM WILL BRING
A CONTINUATION OF COOL AND DRY ADVECTION THOUGH NOT WITH THE
STRENGTH SEEN ON SUNDAY. EVEN SO THE PERSISTENCE OF THE ADVECTION
MAY WIN OUT OVER SOLAR MODIFICATION FOR A GRADUAL DOWNWARD TREND IN
TEMPERATURES TOWARDS CLIMATOLOGY OR A LITTLE BELOW BY THE PERIOD`S
END.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...IFR CONDITIONS WILL BE SETTING UP SHORTLY WITH MAINLY
MVFR/VFR VISIBILITIES. HIGH PRESSURE WILL CONTINUE TO RIDGE JUST
WEST OF THE CWA. THE HRRR MODEL KEEPS ANY PRECIP OFFSHORE AT THIS
TIME...BUT COULD NOT RULE OUT A SPRINKLE AT THE COASTAL TERMINALS
TOWARD MORNING. THURSDAY...A GRADUAL IMPROVEMENT IS FORECAST WITH
CLOUDS SCATTERING IN THE AFTERNOON...ONLY TO RETURN AS STRATUS
SHORTLY AFTER DARK.
EXTENDED OUTLOOK...POTENTIAL FOR MVFR IN SHOWERS FRIDAY
AND EARLY SUNDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 AM THURSDAY...A SMALL CRAFT ADVISORY IS IN EFFECT FOR
ALL WATERS INTO THU. A TIGHT PRESSURE GRADIENT WILL REMAIN ACROSS
THE WATERS WITH A WEDGE OF HIGH PRESSURE HOLDING ACROSS THE
WESTERN CAROLINAS AS LOW PRESSURE MOVES NE...BUT REMAINS OFFSHORE
AS IT PARALLELS THE SOUTHEAST COAST THROUGH THU. THE WIND
DIRECTION WILL REMAIN NNE TO NE AT SPEEDS OF 20 TO 30 KT. SEAS
WILL BE IN THE RANGE OF 5 TO 8 FT ACROSS THE OUTER WATERS. AS YOU
MOVE INTO LONG BAY...SEAS WILL BE CONSIDERABLY LOWER GIVEN THE
SEVERE FETCH RESTRICTIONS ON A NORTHERLY FLOW.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...NORTHEAST WINDS WILL PREVAIL ACROSS THE WATERS
THROUGH THE PERIOD. HOWEVER THE GRADIENT DOES WEAKEN AND SPEEDS GO
FROM 15-20 KNOTS THURSDAY TO TEN KNOTS OR LESS BY SATURDAY MORNING.
SMALL CRAFT SEAS WILL CONTINUE THURSDAY BUT BECOME MORE MARGINAL FOR
THE REMAINDER OF THE PERIOD. STILL A SIX FOOTER OR TWO SHOWING UP
FOR THURSDAY NIGHT INTO FRIDAY SO SOME FINE TUNING WILL BE IN ORDER
TO DETERMINE THE NATURE OF HEADLINES.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...WIND GOES FROM EASTERLY/ONSHORE TO SOUTHERLY
ON SATURDAY WITH THE PASSAGE OF A WARM FRONT. THE INCREASE IN
SOUTHWESTERLY PRE COLD-FRONTAL FLOW WILL BE DELAYED UNTIL LATE
SATURDAY AND THEN MORESO SATURDAY NIGHT AS A FAIRLY STRONG COLD
FRONT IMPINGES UPON THE AREA. SEAS MAY BRIEFLY BUILD TO ADVISORY-
WORTHY 6 FT WELL AWAY FROM SHORE. THE REMAINDER OF SUNDAY WILL
FEATURE SOME FRESH OFFSHORE FLOW BUT LIKELY NOT TO WHERE ADVISORY
WILL BE MAINTAINED THOUGH SCEC IS TOUGH TO RULE OUT. HIGH PRESSURE
BUILDING IN FROM THE NORTHWEST ON MONDAY VEERS WINDS TO THE NORTH
WHILE WIND AND SEAS REMAIN NEAR SCEC HEADLINE VALUES ESPECIALLY OVER
NORTHERN WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ250-252-254-
256.
&&
$$
NEAR TERM...RJD/MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...DL/MJC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
103 PM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 102 PM CST THU JAN 7 2016
REMOVED WINTER STORM WARNING AND REPLACED IT WITH A WINTER WEATHER
ADVISORY OVER PARTS OF SOUTHEAST ND AND INTO MN. WINTER WEATHER
ADVISORY NOW COVERS MUCH OF NORTHWEST AND WEST CENTRAL MN. LOOKING
FOR TWO TO FOUR INCHES OF SNOW ROUGHLY FROM GEORGETOWN TO WASKISH
MN. ELSEWHERE LEES SNOW AND SOME FREEZING DRIZZLE WILL BE POSSIBLE
THIS AFTERNOON.
UPDATE ISSUED AT 1004 AM CST THU JAN 7 2016
WATER VAPOR LOOP INDICATED A WEAK UPPER TROUGH OVER CENTRAL ND AND
WAS MOVING EAST. 3 G/KG MIXING RATIOS WERE OVER THE SOUTHEAST ZONES
AND PRECIPITABLE WATER WAS AROUND HALF AN INCH OVER THE
SOUTH/SOUTHEAST ZONES. SURFACE LOW WAS SOUTHEAST OF ABR AND IS
FORECAST TO MOVE NORTHEAST TODAY. RADAR CONTINUES TO SHOW PRECIP
ACCUMULATING OVER SOUTHERN ZONES. WILL KEEP CURRENT ADVISORIES AND
WARNINGS GOING.
UPDATE ISSUED AT 639 AM CST THU JAN 7 2016
SNOW BAND CONTINUES TO EXPAND NORTHEASTWARD...WITH MORE RETURNS
DEVELOPING BACK TO THE SOUTHEAST. SHORT RANGE MODELS CONTINUE TO
KEEP SOME DECENT QPF OVER THE CWA THROUGH THE REST OF THE MORNING.
AND THERE WILL BE FREEZING DRIZZLE LINGERING A BIT LONGER IN SOME
AREAS. WILL EXTEND THE HEADLINES UNTIL 18Z. MAY NEED TO GO LONGER
IF THE HRRR VERIFIES BUT FOR NOW JUST KEEP IT GOING THROUGH THE
NEXT SIX HOURS AND SEE HOW THINGS DEVELOP. ALSO EXPANDED THE
WARNING UP INTO MAHNOMEN...EASTERN POLK...AND NORTHERN CLEARWATER
COUNTIES AS THE BAND MOVES NORTHEAST AND PULLED TRAILL BACK DOWN
TO ADVISORY AS IT SEEMS THE HEAVIEST AMOUNTS HAVE MISSED THEM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
WHAT HAPPENS WITH THE MESOSCALE SNOW BAND AND WHAT TO DO WITH
HEADLINES WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM.
WEAK SHORTWAVE TROUGH MOVING THROUGH ND...WITH A SFC LOW OVER
NORTH CENTRAL SD. THE MESOSCALE SNOW BAND OVER THE SOUTHERN RED
RIVER VALLEY HAS CONTINUED TO SLOWLY MOVE SOUTHEAST. THE
MID LEVEL FRONTOGENESIS DOES NOT LOOK ALL THAT STRONG WHERE THE
BAND IS LOCATED...BUT WITH NEGATIVE EPV AND HIGH MID LEVEL LAPSE
RATES THERE HAS BEEN ENOUGH INSTABILITY TO GET A NARROW AREA OF
HEAVY SNOW. WHERE THE BEST FRONTOGENSIS IS LOCATED OVER THE
NORTHWESTERN CWA A BAND TRIED TO GET GOING...BUT SEEMS TO BE
DISSIPATING LAST FEW SCANS. THERE HAS BEEN A REPORT OF 6 PLUS
INCHES IN CASSELTON SO THE WARNING SEEMS TO BE ON TRACK. THE HOP
WRF...RAP...AND HRRR ALL HAVE A NARROW BAND OF HIGH SNOW
ACCUMULATION EXTENDING FROM CENTRAL CASS COUNTY UP INTO THE
CLAY/NORMAN AREA. THERE ARE HINTS THAT THE HEAVY SNOW COULD EXTEND
FURTHER NORTHEAST...AND THERE HAS BEEN SOME FAIRLY HEAVY RADAR
RETURNS IN NORTHEASTERN MAHNOMEN COUNTY CURRENTLY. GIVEN THAT THE
EPV AND LAPSE RATES SLOWLY BECOME A BIT LESS FAVORABLE GOING INTO
TODAY...AM NOT SURE HOW LONG THE BAND WILL BE PRODUCING 2 PLUS PER
HOUR SNOWFALL RATES. HAVE THE HEAVY SNOW BAND IN THE GRIDS
EXTENDING INTO THE FAR CORNER OF MAHNOMEN...BUT WILL KEEP THE
HEADLINES AS THEY ARE FOR NOW AND REEVALUATE WHEN WE GET A BIT
MORE GROUND TRUTH LATER THIS MORNING.
THE OTHER ISSUE WILL BE FREEZING DRIZZLE. THE PKD ASOS CONTINUES
TO REPORT AN I GROUP AT TIMES...AND MODEL SOUNDING ACROSS MUCH OF
THE CWA SHOW A DRY LAYER ALOFT EXCEPT WHEN THE SNOW BAND IS
GOING THROUGH. WILL CONTINUE TO KEEP A FREEZING DRIZZLE MENTION
THROUGH THE REST OF THE MORNING AND WILL KEEP THE ADVISORY GOING
IN THE SOUTH FOR THAT REASON. THERE ARE SOME SIGNS OF DRIER AIR
ALOFT COMING IN TONIGHT...PARTICULARLY IN THE WESTERN COUNTIES AS
COLDER AIR COMES DOWN THE BACKSIDE OF THE SFC LOW. WILL INCLUDE A
SLIGHT CHANCE OF FREEZING DRIZZLE MENTION FOR TONIGHT...FOLLOWING
WHERE THE MODELS HAVE THE LOWER CHANCES OF ICE CRYSTALS IN THE
CLOUD.
LIGHT SNOW WILL ALSO CONTINUE AT TIMES AS THE MAIN UPPER
TROUGH DIGS DOWN OUT OF CANADA ON FRIDAY. DO NOT THINK THERE WILL
BE VERY MUCH ACCUMULATION...BUT KEPT SOME CHANCE POPS FOR UP TO
HALF AN INCH OF ACCUMULATION. THE ARCTIC AIR WILL START BUILDING
DOWN INTO THE NORTHERN PLAINS FRIDAY. MODELS HAVE 925MB
TEMPERATURES DOWN TO -20 C BY LATE AFTERNOON. THINK THAT READINGS
WILL FALL THROUGHOUT THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
FRIDAY NIGHT THROUGH SATURDAY NIGHT...ARCTIC HIGH PRESSURE PARKS
ITSELF OVER THE NORTHERN PLAINS. THINK THAT THERE MAY BE A BIT OF
LIGHT SNOW LINGERING OVER THE NORTHEAST INTO FRIDAY NIGHT...BUT
OTHERWISE THERE WILL BE CLEARING OUT AND COLD THROUGH THE PERIOD.
TEMPS WILL BE BELOW ZERO EVEN INTO SATURDAY AFTERNOON...AND COULD
DROP DOWN TO THE 15 TO 20 BELOW RANGE SATURDAY NIGHT. WIND CHILLS
WILL ALSO MAKE IT SEEM EVEN COLDER.
SUNDAY-WEDNESDAY...BELOW AVE TEMPS WILL CONTINUE TO BE THE THEME
DURING THIS TIME. ANOTHER COLD DAY IS EXPECTED FOR SUNDAY...EVEN AS
THE COLDEST 850 MB TEMPS SHIFT EAST AND THE SFC HIGH DROPS SOUTH OF
REGION. THE NEXT ARCTIC FRONT LOOKS TO SWEEP THROUGH AROUND
MONDAY...REINFORCING THE COLD AIR THROUGH THE EARLY PART OF THE
WEEK. CURRENTLY HAVE THE EARLY WEEK PERIOD DRY...BUT THE 00Z
GFS/ECMWF DO SHOW A CLIPPER SYSTEM MOVING SOUTH WITH THE ARCTIC AIR
MONDAY...WITH SOME POTENTIAL FOR LIGHT SNOW. SOME MODERATION IN
TEMPS IS POSSIBLE BY MID-WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 102 PM CST THU JAN 7 2016
STILL DEALING WITH MAJORITY IFR CONDITIONS ACROSS THE AREA INTO
FRIDAY MORNING. THE PUSH OF COLDER BUT EVENTUALLY DRIER AIRMASS
FROM THE NORTH WILL KICK THE LOW LEVEL MOISTURE OUT BUT PROBABLY NOT
TIL LATE FRIDAY/FRIDAY NIGHT. UNTIL THEN WILL MAINTAIN MOSTLY IFR
AND LOW END MVFR CIGS. VARIABLE VISIBILITY WITH CONTINUED FOG
PATCHES AND LIGHT SNOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
MNZ001>003-009-013>017-022>024-027>032-040.
&&
$$
UPDATE...HOPPES
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1233 PM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 1216 PM CST THU JAN 7 2016
LATEST BATCH OF OBSERVATIONS CONTINUE TO SHOW A SCATTERING OF FOG
WITH A FEW REPORTS OF FREEZING DRIZZLE. THEREFORE WILL PUT PATCHY
FOG/FREEZING DRIZZLE ACROSS THE AREA THROUGH TONIGHT DISSIPATING
FROM NORTHWEST TO SOUTHEAST FRIDAY MORNING AS THE COLD AIRMASS
SHIFTS IN. OTHERWISE...ONLY OTHER CONCERN WAS THE SMALL AREA OF
SNOW MOVING THROUGH NORTHERN PORTIONS OF NORTH DAKOTA SO HAVE
ADJUSTED POPS ACCORDINGLY.
UPDATE ISSUED AT 904 AM CST THU JAN 7 2016
MAIN AREA OF SNOW THAT WAS AFFECTING DICKEY AND LAMOURE COUNTIES HAS
PUSHED TO THE EAST WITH ONLY SOME LIGHT SNOW REMAINING.
THEREFORE...HAVE LET ADVISORY EXPIRE. TO THE NORTH...A WEAK WAVE
MOVING THROUGH IS PRODUCING SOME VERY LIGHT SNOW SO HAVE ADDED
SOME LOW POPS ALONG THE CANADIAN BORDER. OTHERWISE...PREVIOUS
FORECAST WAS IN GOOD SHAPE AND HAD THE FOG AND FREEZING DRIZZLE
ADDRESSED WELL.
UPDATE ISSUED AT 641 AM CST THU JAN 7 2016
EXPANDED THE MENTION OF LIGHT FREEZING DRIZZLE TO ALL OF SOUTH
CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY THIS
MORNING...THROUGH TONIGHT BASED UPON THE NDDOT TRAVEL MAP AS OF 12
UTC...AND 11 UTC RAP SOUNDINGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU JAN 7 2016
THE MAIN FOCUS FOR TODAY AND TONIGHT IS FREEZING PRECIPITATION.
AN UPPER LEVEL SHORTWAVE CENTERED OVER NORTH DAKOTA...AN INVERTED
SURFACE TROUGH NOSING INTO THE EASTERN DAKOTAS AND MOIST UPSLOPE
FLOW WERE PROVIDING AMPLE LIFT FOR PRECIPITATION DEVELOPMENT THIS
MORNING.
AREAS OF LIGHT SNOW AND FREEZING DRIZZLE CONTINUE TO DEVELOP
ACROSS THE SOUTHERN JAMES VALLEY. PRECIPITATION WILL LIKELY
CONTINUE THERE FOR THE NEXT SEVERAL HOURS AND CLEAR OUT BY THE
LATE MORNING HOURS AS THE WAVE SHIFTS EAST. ONLY MINOR
ACCUMULATIONS OF SNOW ARE EXPECTED (GENERALLY LESS THAN ONE HALF
INCH)...HOWEVER...SOUNDINGS FAVOR A FREEZING DRIZZLE MODE FOR AN
EXTENDED PERIOD OF TIME. THIS MAY LEAD TO A THIN GLAZE OF ICE.
AFTER THE WAVE PUSHES EAST THIS MORNING...ANOTHER WAVE IS EXPECTED
TO ENTER THE AREA TONIGHT. WITH PLENTY OF LOW LEVEL MOISTURE
REMAINING THIS WILL PROVIDE THE LIFT NECESSARY TO REDEVELOP
PRECIPITATION. FREEZING DRIZZLE IS FAVORED ACROSS SOUTH CENTRAL
NORTH DAKOTA AS SLIGHTLY WARMER TEMPERATURES ALOFT ARE FORECAST TO
LEAD TO AN UNSATURATED DENDRITIC GROWTH ZONE. FURTHER WEST AND
NORTH COOLER AIR SHOULD KEEP PRECIPITATION IN THE FORM OF ALL
SNOW. ONLY MINOR ACCUMULATIONS ARE EXPECTED...GENERALLY AN INCH
OR LESS ACROSS PORTIONS OF NORTHERN AND WESTERN NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU JAN 7 2016
TWO ARCTIC AIRMASSES AND DANGEROUS WIND CHILLS HIGHLIGHT THE
EXTENDED FORECAST.
PRIOR TO THE ARRIVAL OF THE FIRST ARCTIC AIRMASS...THE 00 AND
INCOMING 06 UTC NAM AND GFS BUFR SOUNDINGS SUPPORT THE POTENTIAL
FOR FREEZING DRIZZLE ACROSS MUCH OF CENTRAL NORTH DAKOTA FRIDAY
MORNING WITH LOW LEVEL SATURATION WARMER THAN -10 C AND A LACK OF
ICE CRYSTALS IN THE COLUMN.
THEREAFTER...THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES
CONTINUE TO SHOW GOOD AGREEMENT ON TWO POSSIBLE ARCTIC AIRMASSES
TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA. THE FIRST...ARRIVING
THROUGH THE DAY ON FRIDAY AND REMAINING IN PLACE THROUGH THE
WEEKEND...WITH A POSSIBLE SECOND SURGE OF ARCTIC AIR MONDAY INTO
TUESDAY. WIDESPREAD DANGEROUS WIND CHILLS AS LOW AS 35 BELOW ARE
FORECAST DURING THE MORNING AND NIGHTTIME HOURS OF SATURDAY AND
SUNDAY. A WIND CHILL ADVISORY WILL LIKELY BE NEEDED THIS WEEKEND.
OVERALL...THE WIND FIELD WITH THE POSSIBLE SECOND SURGE OF ARCTIC
AIR IS STRONGER WHEN COMPARED TO THE FIRST...WHICH MAY INTRODUCE A
BLOWING SNOW THREAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1216 PM CST THU JAN 7 2016
IFR AND LIFR IN STRATUS AND FOG WILL PREVAIL TODAY INTO THIS
EVENING OVER MOST LOCATIONS. CIGS AND VIS MAY IMPROVE TO MVFR ON
FRIDAY AS A COLD AIRMASS SHIFTS INTO THE AREA AND THE FOG AND
FREEZING DRIZZLE DISSIPATE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...AJ
LONG TERM...AYD
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1004 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 1004 AM CST THU JAN 7 2016
WATER VAPOR LOOP INDICATED A WEAK UPPER TROUGH OVER CENTRAL ND AND
WAS MOVING EAST. 3 G/KG MIXING RATIOS WERE OVER THE SOUTHEAST ZONES
AND PRECIPITABLE WATER WAS AROUND HALF AN INCH OVER THE
SOUTH/SOUTHEAST ZONES. SURFACE LOW WAS SOUTHEAST OF ABR AND IS
FORECAST TO MOVE NORTHEAST TODAY. RADAR CONTINUES TO SHOW PRECIP
ACCUMULATING OVER SOUTHERN ZONES. WILL KEEP CURRENT ADVISORIES AND
WARNINGS GOING.
UPDATE ISSUED AT 639 AM CST THU JAN 7 2016
SNOW BAND CONTINUES TO EXPAND NORTHEASTWARD...WITH MORE RETURNS
DEVELOPING BACK TO THE SOUTHEAST. SHORT RANGE MODELS CONTINUE TO
KEEP SOME DECENT QPF OVER THE CWA THROUGH THE REST OF THE MORNING.
AND THERE WILL BE FREEZING DRIZZLE LINGERING A BIT LONGER IN SOME
AREAS. WILL EXTEND THE HEADLINES UNTIL 18Z. MAY NEED TO GO LONGER
IF THE HRRR VERIFIES BUT FOR NOW JUST KEEP IT GOING THROUGH THE
NEXT SIX HOURS AND SEE HOW THINGS DEVELOP. ALSO EXPANDED THE
WARNING UP INTO MAHNOMEN...EASTERN POLK...AND NORTHERN CLEARWATER
COUNTIES AS THE BAND MOVES NORTHEAST AND PULLED TRAILL BACK DOWN
TO ADVISORY AS IT SEEMS THE HEAVIEST AMOUNTS HAVE MISSED THEM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
WHAT HAPPENS WITH THE MESOSCALE SNOW BAND AND WHAT TO DO WITH
HEADLINES WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM.
WEAK SHORTWAVE TROUGH MOVING THROUGH ND...WITH A SFC LOW OVER
NORTH CENTRAL SD. THE MESOSCALE SNOW BAND OVER THE SOUTHERN RED
RIVER VALLEY HAS CONTINUED TO SLOWLY MOVE SOUTHEAST. THE
MID LEVEL FRONTOGENESIS DOES NOT LOOK ALL THAT STRONG WHERE THE
BAND IS LOCATED...BUT WITH NEGATIVE EPV AND HIGH MID LEVEL LAPSE
RATES THERE HAS BEEN ENOUGH INSTABILITY TO GET A NARROW AREA OF
HEAVY SNOW. WHERE THE BEST FRONTOGENSIS IS LOCATED OVER THE
NORTHWESTERN CWA A BAND TRIED TO GET GOING...BUT SEEMS TO BE
DISSIPATING LAST FEW SCANS. THERE HAS BEEN A REPORT OF 6 PLUS
INCHES IN CASSELTON SO THE WARNING SEEMS TO BE ON TRACK. THE HOP
WRF...RAP...AND HRRR ALL HAVE A NARROW BAND OF HIGH SNOW
ACCUMULATION EXTENDING FROM CENTRAL CASS COUNTY UP INTO THE
CLAY/NORMAN AREA. THERE ARE HINTS THAT THE HEAVY SNOW COULD EXTEND
FURTHER NORTHEAST...AND THERE HAS BEEN SOME FAIRLY HEAVY RADAR
RETURNS IN NORTHEASTERN MAHNOMEN COUNTY CURRENTLY. GIVEN THAT THE
EPV AND LAPSE RATES SLOWLY BECOME A BIT LESS FAVORABLE GOING INTO
TODAY...AM NOT SURE HOW LONG THE BAND WILL BE PRODUCING 2 PLUS PER
HOUR SNOWFALL RATES. HAVE THE HEAVY SNOW BAND IN THE GRIDS
EXTENDING INTO THE FAR CORNER OF MAHNOMEN...BUT WILL KEEP THE
HEADLINES AS THEY ARE FOR NOW AND REEVALUATE WHEN WE GET A BIT
MORE GROUND TRUTH LATER THIS MORNING.
THE OTHER ISSUE WILL BE FREEZING DRIZZLE. THE PKD ASOS CONTINUES
TO REPORT AN I GROUP AT TIMES...AND MODEL SOUNDING ACROSS MUCH OF
THE CWA SHOW A DRY LAYER ALOFT EXCEPT WHEN THE SNOW BAND IS
GOING THROUGH. WILL CONTINUE TO KEEP A FREEZING DRIZZLE MENTION
THROUGH THE REST OF THE MORNING AND WILL KEEP THE ADVISORY GOING
IN THE SOUTH FOR THAT REASON. THERE ARE SOME SIGNS OF DRIER AIR
ALOFT COMING IN TONIGHT...PARTICULARLY IN THE WESTERN COUNTIES AS
COLDER AIR COMES DOWN THE BACKSIDE OF THE SFC LOW. WILL INCLUDE A
SLIGHT CHANCE OF FREEZING DRIZZLE MENTION FOR TONIGHT...FOLLOWING
WHERE THE MODELS HAVE THE LOWER CHANCES OF ICE CRYSTALS IN THE
CLOUD.
LIGHT SNOW WILL ALSO CONTINUE AT TIMES AS THE MAIN UPPER
TROUGH DIGS DOWN OUT OF CANADA ON FRIDAY. DO NOT THINK THERE WILL
BE VERY MUCH ACCUMULATION...BUT KEPT SOME CHANCE POPS FOR UP TO
HALF AN INCH OF ACCUMULATION. THE ARCTIC AIR WILL START BUILDING
DOWN INTO THE NORTHERN PLAINS FRIDAY. MODELS HAVE 925MB
TEMPERATURES DOWN TO -20 C BY LATE AFTERNOON. THINK THAT READINGS
WILL FALL THROUGHOUT THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
FRIDAY NIGHT THROUGH SATURDAY NIGHT...ARCTIC HIGH PRESSURE PARKS
ITSELF OVER THE NORTHERN PLAINS. THINK THAT THERE MAY BE A BIT OF
LIGHT SNOW LINGERING OVER THE NORTHEAST INTO FRIDAY NIGHT...BUT
OTHERWISE THERE WILL BE CLEARING OUT AND COLD THROUGH THE PERIOD.
TEMPS WILL BE BELOW ZERO EVEN INTO SATURDAY AFTERNOON...AND COULD
DROP DOWN TO THE 15 TO 20 BELOW RANGE SATURDAY NIGHT. WIND CHILLS
WILL ALSO MAKE IT SEEM EVEN COLDER.
SUNDAY-WEDNESDAY...BELOW AVE TEMPS WILL CONTINUE TO BE THE THEME
DURING THIS TIME. ANOTHER COLD DAY IS EXPECTED FOR SUNDAY...EVEN AS
THE COLDEST 850 MB TEMPS SHIFT EAST AND THE SFC HIGH DROPS SOUTH OF
REGION. THE NEXT ARCTIC FRONT LOOKS TO SWEEP THROUGH AROUND
MONDAY...REINFORCING THE COLD AIR THROUGH THE EARLY PART OF THE
WEEK. CURRENTLY HAVE THE EARLY WEEK PERIOD DRY...BUT THE 00Z
GFS/ECMWF DO SHOW A CLIPPER SYSTEM MOVING SOUTH WITH THE ARCTIC AIR
MONDAY...WITH SOME POTENTIAL FOR LIGHT SNOW. SOME MODERATION IN
TEMPS IS POSSIBLE BY MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 639 AM CST THU JAN 7 2016
IFR CONDITIONS AT MOST LOCATIONS ALTHOUGH A FEW SPOTS HAVE TRIED
TO GO UP TO MVFR. THINK THAT THE LOWER STRATUS WILL HANG AROUND
FOR MUCH OF THE DAY AND KEPT IFR AND LOWER CIGS THROUGH THE END OF
THE TAF PERIOD. VIS WILL BE DIFFICULT WITH SNOW MOVING THROUGH.
HEAVIER SNOW IS STILL SEEN ON RADAR APPROACHING KFAR...SO INCLUDED
A TEMPO GROUP FOR SOME SUB 1SM VIS FOR A SHORT TIME...BUT
OTHERWISE MOST SITES WILL BE MOSTLY IN THE 2-5SM RANGE WITH BRIEF
VIS REDUCTIONS DOWN TO 1SM. BY THIS EVENING THE HEAVIER BANDS WILL
DISSIPATE BUT THERE COULD BE SOME VERY LIGHT SNOW OR FLURRIES
HANGING AROUND AND KEEPING VIS DOWN AT SOME SPOTS. WINDS WILL BE
GENERALLY OUT OF THE NORTH AT LESS THAN 12 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NDZ028>030-038-
049-052-053.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR NDZ039.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ001-009-013-
014-017-023-024-027>032-040.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR MNZ002-003-015-016-
022.
&&
$$
UPDATE...HOPPES
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
945 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 904 AM CST THU JAN 7 2016
MAIN AREA OF SNOW THAT WAS AFFECTING DICKEY AND LAMOURE COUNTIES HAS
PUSHED TO THE EAST WITH ONLY SOME LIGHT SNOW REMAINING.
THEREFORE...HAVE LET ADVISORY EXPIRE. TO THE NORTH...A WEAK WAVE
MOVING THROUGH IS PRODUCING SOME VERY LIGHT SNOW SO HAVE ADDED
SOME LOW POPS ALONG THE CANADIAN BORDER. OTHERWISE...PREVIOUS
FORECAST WAS IN GOOD SHAPE AND HAD THE FOG AND FREEZING DRIZZLE
ADDRESSED WELL.
UPDATE ISSUED AT 641 AM CST THU JAN 7 2016
EXPANDED THE MENTION OF LIGHT FREEZING DRIZZLE TO ALL OF SOUTH
CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY THIS
MORNING...THROUGH TONIGHT BASED UPON THE NDDOT TRAVEL MAP AS OF 12
UTC...AND 11 UTC RAP SOUNDINGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU JAN 7 2016
THE MAIN FOCUS FOR TODAY AND TONIGHT IS FREEZING PRECIPITATION.
AN UPPER LEVEL SHORTWAVE CENTERED OVER NORTH DAKOTA...AN INVERTED
SURFACE TROUGH NOSING INTO THE EASTERN DAKOTAS AND MOIST UPSLOPE
FLOW WERE PROVIDING AMPLE LIFT FOR PRECIPITATION DEVELOPMENT THIS
MORNING.
AREAS OF LIGHT SNOW AND FREEZING DRIZZLE CONTINUE TO DEVELOP
ACROSS THE SOUTHERN JAMES VALLEY. PRECIPITATION WILL LIKELY
CONTINUE THERE FOR THE NEXT SEVERAL HOURS AND CLEAR OUT BY THE
LATE MORNING HOURS AS THE WAVE SHIFTS EAST. ONLY MINOR
ACCUMULATIONS OF SNOW ARE EXPECTED (GENERALLY LESS THAN ONE HALF
INCH)...HOWEVER...SOUNDINGS FAVOR A FREEZING DRIZZLE MODE FOR AN
EXTENDED PERIOD OF TIME. THIS MAY LEAD TO A THIN GLAZE OF ICE.
AFTER THE WAVE PUSHES EAST THIS MORNING...ANOTHER WAVE IS EXPECTED
TO ENTER THE AREA TONIGHT. WITH PLENTY OF LOW LEVEL MOISTURE
REMAINING THIS WILL PROVIDE THE LIFT NECESSARY TO REDEVELOP
PRECIPITATION. FREEZING DRIZZLE IS FAVORED ACROSS SOUTH CENTRAL
NORTH DAKOTA AS SLIGHTLY WARMER TEMPERATURES ALOFT ARE FORECAST TO
LEAD TO AN UNSATURATED DENDRITIC GROWTH ZONE. FURTHER WEST AND
NORTH COOLER AIR SHOULD KEEP PRECIPITATION IN THE FORM OF ALL
SNOW. ONLY MINOR ACCUMULATIONS ARE EXPECTED...GENERALLY AN INCH
OR LESS ACROSS PORTIONS OF NORTHERN AND WESTERN NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU JAN 7 2016
TWO ARCTIC AIRMASSES AND DANGEROUS WIND CHILLS HIGHLIGHT THE
EXTENDED FORECAST.
PRIOR TO THE ARRIVAL OF THE FIRST ARCTIC AIRMASS...THE 00 AND
INCOMING 06 UTC NAM AND GFS BUFR SOUNDINGS SUPPORT THE POTENTIAL
FOR FREEZING DRIZZLE ACROSS MUCH OF CENTRAL NORTH DAKOTA FRIDAY
MORNING WITH LOW LEVEL SATURATION WARMER THAN -10 C AND A LACK OF
ICE CRYSTALS IN THE COLUMN.
THEREAFTER...THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES
CONTINUE TO SHOW GOOD AGREEMENT ON TWO POSSIBLE ARCTIC AIRMASSES
TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA. THE FIRST...ARRIVING
THROUGH THE DAY ON FRIDAY AND REMAINING IN PLACE THROUGH THE
WEEKEND...WITH A POSSIBLE SECOND SURGE OF ARCTIC AIR MONDAY INTO
TUESDAY. WIDESPREAD DANGEROUS WIND CHILLS AS LOW AS 35 BELOW ARE
FORECAST DURING THE MORNING AND NIGHTTIME HOURS OF SATURDAY AND
SUNDAY. A WIND CHILL ADVISORY WILL LIKELY BE NEEDED THIS WEEKEND.
OVERALL...THE WIND FIELD WITH THE POSSIBLE SECOND SURGE OF ARCTIC
AIR IS STRONGER WHEN COMPARED TO THE FIRST...WHICH MAY INTRODUCE A
BLOWING SNOW THREAT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 641 AM CST THU JAN 7 2016
IFR AND LIFR IN STRATUS AND FOG WILL PREVAIL AT ALL SITES THROUGH
TODAY ACROSS WESTERN AND CENTRAL NORTH DAKOTA. FREEZING DRIZZLE IS
POSSIBLE AT KBIS AND KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...AJ
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
646 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 641 AM CST THU JAN 7 2016
EXPANDED THE MENTION OF LIGHT FREEZING DRIZZLE TO ALL OF SOUTH
CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY THIS
MORNING...THROUGH TONIGHT BASED UPON THE NDDOT TRAVEL MAP AS OF 12
UTC...AND 11 UTC RAP SOUNDINGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU JAN 7 2016
THE MAIN FOCUS FOR TODAY AND TONIGHT IS FREEZING PRECIPITATION.
AN UPPER LEVEL SHORTWAVE CENTERED OVER NORTH DAKOTA...AN INVERTED
SURFACE TROUGH NOSING INTO THE EASTERN DAKOTAS AND MOIST UPSLOPE
FLOW WERE PROVIDING AMPLE LIFT FOR PRECIPITATION DEVELOPMENT THIS
MORNING.
AREAS OF LIGHT SNOW AND FREEZING DRIZZLE CONTINUE TO DEVELOP
ACROSS THE SOUTHERN JAMES VALLEY. PRECIPITATION WILL LIKELY
CONTINUE THERE FOR THE NEXT SEVERAL HOURS AND CLEAR OUT BY THE
LATE MORNING HOURS AS THE WAVE SHIFTS EAST. ONLY MINOR
ACCUMULATIONS OF SNOW ARE EXPECTED (GENERALLY LESS THAN ONE HALF
INCH)...HOWEVER...SOUNDINGS FAVOR A FREEZING DRIZZLE MODE FOR AN
EXTENDED PERIOD OF TIME. THIS MAY LEAD TO A THIN GLAZE OF ICE.
AFTER THE WAVE PUSHES EAST THIS MORNING...ANOTHER WAVE IS EXPECTED
TO ENTER THE AREA TONIGHT. WITH PLENTY OF LOW LEVEL MOISTURE
REMAINING THIS WILL PROVIDE THE LIFT NECESSARY TO REDEVELOP
PRECIPITATION. FREEZING DRIZZLE IS FAVORED ACROSS SOUTH CENTRAL
NORTH DAKOTA AS SLIGHTLY WARMER TEMPERATURES ALOFT ARE FORECAST TO
LEAD TO AN UNSATURATED DENDRITIC GROWTH ZONE. FURTHER WEST AND
NORTH COOLER AIR SHOULD KEEP PRECIPITATION IN THE FORM OF ALL
SNOW. ONLY MINOR ACCUMULATIONS ARE EXPECTED...GENERALLY AN INCH
OR LESS ACROSS PORTIONS OF NORTHERN AND WESTERN NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU JAN 7 2016
TWO ARCTIC AIRMASSES AND DANGEROUS WIND CHILLS HIGHLIGHT THE
EXTENDED FORECAST.
PRIOR TO THE ARRIVAL OF THE FIRST ARCTIC AIRMASS...THE 00 AND
INCOMING 06 UTC NAM AND GFS BUFR SOUNDINGS SUPPORT THE POTENTIAL
FOR FREEZING DRIZZLE ACROSS MUCH OF CENTRAL NORTH DAKOTA FRIDAY
MORNING WITH LOW LEVEL SATURATION WARMER THAN -10 C AND A LACK OF
ICE CRYSTALS IN THE COLUMN.
THEREAFTER...THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES
CONTINUE TO SHOW GOOD AGREEMENT ON TWO POSSIBLE ARCTIC AIRMASSES
TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA. THE FIRST...ARRIVING
THROUGH THE DAY ON FRIDAY AND REMAINING IN PLACE THROUGH THE
WEEKEND...WITH A POSSIBLE SECOND SURGE OF ARCTIC AIR MONDAY INTO
TUESDAY. WIDESPREAD DANGEROUS WIND CHILLS AS LOW AS 35 BELOW ARE
FORECAST DURING THE MORNING AND NIGHTTIME HOURS OF SATURDAY AND
SUNDAY. A WIND CHILL ADVISORY WILL LIKELY BE NEEDED THIS WEEKEND.
OVERALL...THE WIND FIELD WITH THE POSSIBLE SECOND SURGE OF ARCTIC
AIR IS STRONGER WHEN COMPARED TO THE FIRST...WHICH MAY INTRODUCE A
BLOWING SNOW THREAT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 641 AM CST THU JAN 7 2016
IFR AND LIFR IN STRATUS AND FOG WILL PREVAIL AT ALL SITES THROUGH
TODAY ACROSS WESTERN AND CENTRAL NORTH DAKOTA. FREEZING DRIZZLE IS
POSSIBLE AT KBIS AND KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ048-
051.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
639 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 639 AM CST THU JAN 7 2016
SNOW BAND CONTINUES TO EXPAND NORTHEASTWARD...WITH MORE RETURNS
DEVELOPING BACK TO THE SOUTHEAST. SHORT RANGE MODELS CONTINUE TO
KEEP SOME DECENT QPF OVER THE CWA THROUGH THE REST OF THE MORNING.
AND THERE WILL BE FREEZING DRIZZLE LINGERING A BIT LONGER IN SOME
AREAS. WILL EXTEND THE HEADLINES UNTIL 18Z. MAY NEED TO GO LONGER
IF THE HRRR VERIFIES BUT FOR NOW JUST KEEP IT GOING THROUGH THE
NEXT SIX HOURS AND SEE HOW THINGS DEVELOP. ALSO EXPANDED THE
WARNING UP INTO MAHNOMEN...EASTERN POLK...AND NORTHERN CLEARWATER
COUNTIES AS THE BAND MOVES NORTHEAST AND PULLED TRAILL BACK DOWN
TO ADVISORY AS IT SEEMS THE HEAVIEST AMOUNTS HAVE MISSED THEM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
WHAT HAPPENS WITH THE MESOSCALE SNOW BAND AND WHAT TO DO WITH
HEADLINES WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM.
WEAK SHORTWAVE TROUGH MOVING THROUGH ND...WITH A SFC LOW OVER
NORTH CENTRAL SD. THE MESOSCALE SNOW BAND OVER THE SOUTHERN RED
RIVER VALLEY HAS CONTINUED TO SLOWLY MOVE SOUTHEAST. THE
MID LEVEL FRONTOGENESIS DOES NOT LOOK ALL THAT STRONG WHERE THE
BAND IS LOCATED...BUT WITH NEGATIVE EPV AND HIGH MID LEVEL LAPSE
RATES THERE HAS BEEN ENOUGH INSTABILITY TO GET A NARROW AREA OF
HEAVY SNOW. WHERE THE BEST FRONTOGENSIS IS LOCATED OVER THE
NORTHWESTERN CWA A BAND TRIED TO GET GOING...BUT SEEMS TO BE
DISSIPATING LAST FEW SCANS. THERE HAS BEEN A REPORT OF 6 PLUS
INCHES IN CASSELTON SO THE WARNING SEEMS TO BE ON TRACK. THE HOP
WRF...RAP...AND HRRR ALL HAVE A NARROW BAND OF HIGH SNOW
ACCUMULATION EXTENDING FROM CENTRAL CASS COUNTY UP INTO THE
CLAY/NORMAN AREA. THERE ARE HINTS THAT THE HEAVY SNOW COULD EXTEND
FURTHER NORTHEAST...AND THERE HAS BEEN SOME FAIRLY HEAVY RADAR
RETURNS IN NORTHEASTERN MAHNOMEN COUNTY CURRENTLY. GIVEN THAT THE
EPV AND LAPSE RATES SLOWLY BECOME A BIT LESS FAVORABLE GOING INTO
TODAY...AM NOT SURE HOW LONG THE BAND WILL BE PRODUCING 2 PLUS PER
HOUR SNOWFALL RATES. HAVE THE HEAVY SNOW BAND IN THE GRIDS
EXTENDING INTO THE FAR CORNER OF MAHNOMEN...BUT WILL KEEP THE
HEADLINES AS THEY ARE FOR NOW AND REEVALUATE WHEN WE GET A BIT
MORE GROUND TRUTH LATER THIS MORNING.
THE OTHER ISSUE WILL BE FREEZING DRIZZLE. THE PKD ASOS CONTINUES
TO REPORT AN I GROUP AT TIMES...AND MODEL SOUNDING ACROSS MUCH OF
THE CWA SHOW A DRY LAYER ALOFT EXCEPT WHEN THE SNOW BAND IS
GOING THROUGH. WILL CONTINUE TO KEEP A FREEZING DRIZZLE MENTION
THROUGH THE REST OF THE MORNING AND WILL KEEP THE ADVISORY GOING
IN THE SOUTH FOR THAT REASON. THERE ARE SOME SIGNS OF DRIER AIR
ALOFT COMING IN TONIGHT...PARTICULARLY IN THE WESTERN COUNTIES AS
COLDER AIR COMES DOWN THE BACKSIDE OF THE SFC LOW. WILL INCLUDE A
SLIGHT CHANCE OF FREEZING DRIZZLE MENTION FOR TONIGHT...FOLLOWING
WHERE THE MODELS HAVE THE LOWER CHANCES OF ICE CRYSTALS IN THE
CLOUD.
LIGHT SNOW WILL ALSO CONTINUE AT TIMES AS THE MAIN UPPER
TROUGH DIGS DOWN OUT OF CANADA ON FRIDAY. DO NOT THINK THERE WILL
BE VERY MUCH ACCUMULATION...BUT KEPT SOME CHANCE POPS FOR UP TO
HALF AN INCH OF ACCUMULATION. THE ARCTIC AIR WILL START BUILDING
DOWN INTO THE NORTHERN PLAINS FRIDAY. MODELS HAVE 925MB
TEMPERATURES DOWN TO -20 C BY LATE AFTERNOON. THINK THAT READINGS
WILL FALL THROUGHOUT THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
FRIDAY NIGHT THROUGH SATURDAY NIGHT...ARCTIC HIGH PRESSURE PARKS
ITSELF OVER THE NORTHERN PLAINS. THINK THAT THERE MAY BE A BIT OF
LIGHT SNOW LINGERING OVER THE NORTHEAST INTO FRIDAY NIGHT...BUT
OTHERWISE THERE WILL BE CLEARING OUT AND COLD THROUGH THE PERIOD.
TEMPS WILL BE BELOW ZERO EVEN INTO SATURDAY AFTERNOON...AND COULD
DROP DOWN TO THE 15 TO 20 BELOW RANGE SATURDAY NIGHT. WIND CHILLS
WILL ALSO MAKE IT SEEM EVEN COLDER.
SUNDAY-WEDNESDAY...BELOW AVE TEMPS WILL CONTINUE TO BE THE THEME
DURING THIS TIME. ANOTHER COLD DAY IS EXPECTED FOR SUNDAY...EVEN AS
THE COLDEST 850 MB TEMPS SHIFT EAST AND THE SFC HIGH DROPS SOUTH OF
REGION. THE NEXT ARCTIC FRONT LOOKS TO SWEEP THROUGH AROUND
MONDAY...REINFORCING THE COLD AIR THROUGH THE EARLY PART OF THE
WEEK. CURRENTLY HAVE THE EARLY WEEK PERIOD DRY...BUT THE 00Z
GFS/ECMWF DO SHOW A CLIPPER SYSTEM MOVING SOUTH WITH THE ARCTIC AIR
MONDAY...WITH SOME POTENTIAL FOR LIGHT SNOW. SOME MODERATION IN
TEMPS IS POSSIBLE BY MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 639 AM CST THU JAN 7 2016
IFR CONDITIONS AT MOST LOCATIONS ALTHOUGH A FEW SPOTS HAVE TRIED
TO GO UP TO MVFR. THINK THAT THE LOWER STRATUS WILL HANG AROUND
FOR MUCH OF THE DAY AND KEPT IFR AND LOWER CIGS THROUGH THE END OF
THE TAF PERIOD. VIS WILL BE DIFFICULT WITH SNOW MOVING THROUGH.
HEAVIER SNOW IS STILL SEEN ON RADAR APPROACHING KFAR...SO INCLUDED
A TEMPO GROUP FOR SOME SUB 1SM VIS FOR A SHORT TIME...BUT
OTHERWISE MOST SITES WILL BE MOSTLY IN THE 2-5SM RANGE WITH BRIEF
VIS REDUCTIONS DOWN TO 1SM. BY THIS EVENING THE HEAVIER BANDS WILL
DISSIPATE BUT THERE COULD BE SOME VERY LIGHT SNOW OR FLURRIES
HANGING AROUND AND KEEPING VIS DOWN AT SOME SPOTS. WINDS WILL BE
GENERALLY OUT OF THE NORTH AT LESS THAN 12 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NDZ028>030-038-
049-052-053.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR NDZ039.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ001-009-013-
014-017-023-024-027>032-040.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR MNZ002-003-015-016-
022.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
349 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
WHAT HAPPENS WITH THE MESOSCALE SNOW BAND AND WHAT TO DO WITH
HEADLINES WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM.
WEAK SHORTWAVE TROUGH MOVING THROUGH ND...WITH A SFC LOW OVER
NORTH CENTRAL SD. THE MESOSCALE SNOW BAND OVER THE SOUTHERN RED
RIVER VALLEY HAS CONTINUED TO SLOWLY MOVE SOUTHEAST. THE
MID LEVEL FRONTOGENESIS DOES NOT LOOK ALL THAT STRONG WHERE THE
BAND IS LOCATED...BUT WITH NEGATIVE EPV AND HIGH MID LEVEL LAPSE
RATES THERE HAS BEEN ENOUGH INSTABILITY TO GET A NARROW AREA OF
HEAVY SNOW. WHERE THE BEST FRONTOGENSIS IS LOCATED OVER THE
NORTHWESTERN CWA A BAND TRIED TO GET GOING...BUT SEEMS TO BE
DISSIPATING LAST FEW SCANS. THERE HAS BEEN A REPORT OF 6 PLUS
INCHES IN CASSELTON SO THE WARNING SEEMS TO BE ON TRACK. THE HOP
WRF...RAP...AND HRRR ALL HAVE A NARROW BAND OF HIGH SNOW
ACCUMULATION EXTENDING FROM CENTRAL CASS COUNTY UP INTO THE
CLAY/NORMAN AREA. THERE ARE HINTS THAT THE HEAVY SNOW COULD EXTEND
FURTHER NORTHEAST...AND THERE HAS BEEN SOME FAIRLY HEAVY RADAR
RETURNS IN NORTHEASTERN MAHNOMEN COUNTY CURRENTLY. GIVEN THAT THE
EPV AND LAPSE RATES SLOWLY BECOME A BIT LESS FAVORABLE GOING INTO
TODAY...AM NOT SURE HOW LONG THE BAND WILL BE PRODUCING 2 PLUS PER
HOUR SNOWFALL RATES. HAVE THE HEAVY SNOW BAND IN THE GRIDS
EXTENDING INTO THE FAR CORNER OF MAHNOMEN...BUT WILL KEEP THE
HEADLINES AS THEY ARE FOR NOW AND REEVALUATE WHEN WE GET A BIT
MORE GROUND TRUTH LATER THIS MORNING.
THE OTHER ISSUE WILL BE FREEZING DRIZZLE. THE PKD ASOS CONTINUES
TO REPORT AN I GROUP AT TIMES...AND MODEL SOUNDING ACROSS MUCH OF
THE CWA SHOW A DRY LAYER ALOFT EXCEPT WHEN THE SNOW BAND IS
GOING THROUGH. WILL CONTINUE TO KEEP A FREEZING DRIZZLE MENTION
THROUGH THE REST OF THE MORNING AND WILL KEEP THE ADVISORY GOING
IN THE SOUTH FOR THAT REASON. THERE ARE SOME SIGNS OF DRIER AIR
ALOFT COMING IN TONIGHT...PARTICULARLY IN THE WESTERN COUNTIES AS
COLDER AIR COMES DOWN THE BACKSIDE OF THE SFC LOW. WILL INCLUDE A
SLIGHT CHANCE OF FREEZING DRIZZLE MENTION FOR TONIGHT...FOLLOWING
WHERE THE MODELS HAVE THE LOWER CHANCES OF ICE CRYSTALS IN THE
CLOUD.
LIGHT SNOW WILL ALSO CONTINUE AT TIMES AS THE MAIN UPPER
TROUGH DIGS DOWN OUT OF CANADA ON FRIDAY. DO NOT THINK THERE WILL
BE VERY MUCH ACCUMULATION...BUT KEPT SOME CHANCE POPS FOR UP TO
HALF AN INCH OF ACCUMULATION. THE ARCTIC AIR WILL START BUILDING
DOWN INTO THE NORTHERN PLAINS FRIDAY. MODELS HAVE 925MB
TEMPERATURES DOWN TO -20 C BY LATE AFTERNOON. THINK THAT READINGS
WILL FALL THROUGHOUT THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
FRIDAY NIGHT THROUGH SATURDAY NIGHT...ARCTIC HIGH PRESSURE PARKS
ITSELF OVER THE NORTHERN PLAINS. THINK THAT THERE MAY BE A BIT OF
LIGHT SNOW LINGERING OVER THE NORTHEAST INTO FRIDAY NIGHT...BUT
OTHERWISE THERE WILL BE CLEARING OUT AND COLD THROUGH THE PERIOD.
TEMPS WILL BE BELOW ZERO EVEN INTO SATURDAY AFTERNOON...AND COULD
DROP DOWN TO THE 15 TO 20 BELOW RANGE SATURDAY NIGHT. WIND CHILLS
WILL ALSO MAKE IT SEEM EVEN COLDER.
SUNDAY-WEDNESDAY...BELOW AVE TEMPS WILL CONTINUE TO BE THE THEME
DURING THIS TIME. ANOTHER COLD DAY IS EXPECTED FOR SUNDAY...EVEN AS
THE COLDEST 850 MB TEMPS SHIFT EAST AND THE SFC HIGH DROPS SOUTH OF
REGION. THE NEXT ARCTIC FRONT LOOKS TO SWEEP THROUGH AROUND
MONDAY...REINFORCING THE COLD AIR THROUGH THE EARLY PART OF THE
WEEK. CURRENTLY HAVE THE EARLY WEEK PERIOD DRY...BUT THE 00Z
GFS/ECMWF DO SHOW A CLIPPER SYSTEM MOVING SOUTH WITH THE ARCTIC AIR
MONDAY...WITH SOME POTENTIAL FOR LIGHT SNOW. SOME MODERATION IN
TEMPS IS POSSIBLE BY MID-WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1143 PM CST WED JAN 6 2016
TRIED TO TIME THE HEAVY SNOW BAND AS BEST POSSIBLE...MAINLY
AFFECTING KFAR/KBJI. LOOKS LIKE IT SHOULD MOVE OUT DURING
THURSDAY MORNING...LEAVING VERY LIGHT SNOW OR FLURRIES AROUND.
LEFT THE LOW CEILINGS IN PLACE THOUGH. WINDS WILL STAY ON THE
LIGHTER SIDE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ028-
029-038-049-052-053.
WINTER STORM WARNING UNTIL 9 AM CST THIS MORNING FOR NDZ030-039.
MN...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ001-
009-013>017-022>024-027>032-040.
WINTER STORM WARNING UNTIL 9 AM CST THIS MORNING FOR MNZ002-003.
&&
$$
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...GODON
AREA FORECAST DISCUSSION
NWS NORMAN OK
959 PM CST FRI JAN 8 2016
.UPDATE...
COMPLICATED FORECAST THIS EVENING. UPPER LOW SPINNING NEAR LUBBOCK
WILL MOVE EAST-NORTHEAST TOWARD THE RED RIVER VALLEY. MEANWHILE
COLD LOW-LEVEL AIR IS FILTERING SOUTHEAST. LOW LEVELS ARE COOL
ENOUGH TO CHANCE PRECIP TO SNOW AS FAR SOUTH AS ERICK/ELK CITY.
RAP AND HRRR SHOW PRIMARY PRECIP BAND NEAR LUBBOCK MAY PIVOT UP
THE I-44 CORRIDOR FROM ROUGHLY CROWELL TO LAWTON TO OKLAHOMA
CITY... BUT WILL THE LOW LEVELS BE COOL ENOUGH FOR PRECIP TO BE
PRIMARILY SNOW WHEN MODERATE PRECIPITATION IS FALLING? WILL BE
WATCHING THIS CLOSELY TO SEE IF THE ADVISORY MAY NEED TO BE
EXPANDED SOUTHEAST A LITTLE BIT THIS EVENING OR OVERNIGHT.
MEANWHILE... THE PRECIPITATION IS LIGHTER FARTHER NORTH... BUT
DURATION OF LIGHT SNOW MAY STILL BE SUFFICIENT FOR AN INCH OR TWO
OF SNOW IN WESTERN AND PORTIONS OF NORTHERN OKLAHOMA... SO WILL
KEEP THE ADVISORY UP THERE. VISIBILITY IN THE AREAS OF SNOW IN
NORTHWEST OKLAHOMA AND THE TEXAS PANHANDLES HAVE GENERALLY BEEN
3-5 MILES SO IT DOES NOT SEEM LIKE IT WILL ACCUMULATE TOO QUICKLY.
DID ISSUE ONE UPDATE EARLIER THIS EVENING TO ACCOUNT FOR CURRENT
TRENDS... AND WILL LET THAT RIDE FOR THE NOW.
&&
.PREV DISCUSSION... /ISSUED 529 PM CST FRI JAN 8 2016/
DISCUSSION...
AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW.
AVIATION...
THE TAFS REMAIN CHALLENGING OVER THE NEXT 24 HOURS. CONFIDENCE
IS RATHER LOW THROUGH 15Z.
THROUGH 12Z...GENERALLY THINK MVFR CONDITIONS WILL OCCUR IN MOST
LOCATIONS AT MOST TIMES. PATCHES OF IFR/LIFR CONDITIONS NEAR KWWR
AND KGAG AS WELL AS IN -SN BANDS WILL OCCUR AS WELL.
PRECIPITATION TYPES REMAIN SOMEWHAT UNCERTAIN...THOUGH
PRECIPITATION AT ALL TAFS SITES SHOULD BE -SN BY 07Z.
AFTER 12Z...CONDITIONS WILL IMPROVE NORTH TO SOUTH. BELIEVE ALL
SITES WILL BE VFR BY 21Z. ANY -SN WILL END BY 18Z.
NORTH WINDS WILL BECOME GUSTY AT MANY SITES BY 12Z.
MBS
PREV DISCUSSION... /ISSUED 303 PM CST FRI JAN 8 2016/
DISCUSSION...
WE EARLIER ISSUED A WINTER WEATHER ADVISORY FOR MUCH OF OUR
FORECAST AREA...BASED ON VERY AGGRESSIVE SNOWFALL AMOUNTS
ADVERTISED BY MOST OF THE FORECAST MODELS AVAILABLE AT THE TIME.
MORE-RECENT TRENDS IN THE MODELS HAVE ADDED A GREAT DEAL OF
UNCERTAINTY TO THE FORECAST...BY PLACING SNOW BANDS IN VARYING
PLACES...WITH FAR LESS GEOGRAPHICAL/TEMPORAL AGREEMENT THAN
BEFORE. AS A RESULT...WE HAVE SMOOTHED THE SNOWFALL FORECAST A
LOT...REMOVING STORM TOTAL AMOUNTS GREATER THAN 2 INCHES. OUR BEST
ESTIMATE AT THIS TIME...HOWEVER...STILL SUPPORTS A WINTER WEATHER
ADVISORY OVER ESSENTIALLY THE SAME AREA AS BEFORE...JUST LESS
CERTAINTY ABOUT SNOWFALL TOTALS. THERE IS STILL A GOOD CHANCE THAT
A STRIPE OF LAND WILL BE COVERED WITH 2 TO 4 INCHES OF SNOW...BUT
IT IS MUCH HARDER TO SAY WHERE THAT STRIPE WILL BE.
SO...WE ARE MAKING NO CHANGES AT THIS ISSUANCE TO EITHER THE
TIMING OR THE GEOGRAPHICAL BOUNDARIES OF OUR ADVISORY. THE
SNOWFALL AMOUNTS HAVE BEEN LOWERED SIGNIFICANTLY IN THE AREA
ROUGHLY FROM MANGUM TO ENID. OTHERWISE...THERE IS NOT MUCH CHANGE
IN THIS PART OF THE FORECAST.
WE HAVE MADE SOME VERY SHORT-RANGE ADJUSTMENTS ALSO TO POPS TO
ACCOMMODATE THE CURRENT RADAR TRENDS. A BAND OF RAIN IS DEVELOPING
FROM NEAR WICHITA FALLS TO SHAWNEE...AND THIS MAY LATER CONVERT
INTO A SNOW BAND LATE TONIGHT...ONCE TEMPERATURES ALOFT FALL
ENOUGH TO MAKE THE CHANGEOVER.
SNOW SHOULD END DURING THE DAY TOMORROW...AND THERE IS NOT MUCH OF
INTEREST IN THE REST OF THE FORECAST. AFTER A COLDER-THAN-AVERAGE
WEEKEND...TEMPERATURES WILL BEGIN A SLOW WARMING TREND THAT WILL
LAST THROUGH NEXT WEEK. ANOTHER DISTURBANCE MAY BRING SOME SHOWERS
TO THE AREA ON THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 30 35 18 30 / 60 20 0 0
HOBART OK 29 37 18 33 / 70 10 0 0
WICHITA FALLS TX 34 42 22 39 / 60 20 0 0
GAGE OK 25 34 13 34 / 70 10 0 0
PONCA CITY OK 29 32 13 31 / 60 20 0 0
DURANT OK 37 41 24 37 / 60 20 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR OKZ004>025-
033>036.
TX...WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR TXZ083.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
1008 AM PST THU JAN 7 2016
.SYNOPSIS...AFTER A FEW RESIDUAL SHOWERS ACROSS THE NORTH PART OF OUR
FORECAST AREA TODAY FROM A WEAK DISTURBANCE THAT MOVED NORTH
OVERNIGHT...A LOW OFF THE OREGON AND NORTHERN CALIFORNIA COAST WILL
SEND ONE MORE BAND OF SHOWERS INTO SOUTHWEST OREGON AND NORTHERN
CALIFORNIA THAT WILL BRUSH PARTS OF OUR FORECAST AREAS FROM ABOUT
SALEM SOUTHWARD TONIGHT AND EARLY FRIDAY. DECREASING OFFSHORE FLOW
WILL RESULT IN INCREASING AREAS OF NIGHT AND MORNING FOG AND LOW
CLOUDS TONIGHT AND FRIDAY. THE NEXT SYSTEM IS FORECAST TO APPROACH
FRIDAY NIGHT...WITH SOME MOISTURE LIFTING NORTH INTO NORTHWEST
OREGON AND SOUTHWEST WASHINGTON LATE FRIDAY NIGHT AND ESPECIALLY ON
SATURDAY. THE SYSTEM WILL STRETCH AND WEAKEN AS IT MOVES NORTH...
THEN OUT OF THE AREA BY EARLY SUNDAY. LOOK FOR WINTER PRECIPITATION
IN THE GORGE...AND POSSIBLY IN AREAS WEST OF THE GORGE NEAR THE
COLUMBIA RIVER. THE NEXT SYSTEM IS EXPECTED EARLY NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH SATURDAY...A LOW REMAINS OFF THE OREGON
AND NORTHERN CALIFORNIA COAST THIS MORNING. A WEAK SHORT WAVE THAT
LIFTED NORTH THROUGH NORTHWEST OREGON AND SOUTHWEST WASHINGTON
OVERNIGHT STILL HAD A FEW SHOWERS AROUND THIS MORNING FROM ABOUT
PORTLAND NORTH...WHICH WILL LINGER INTO THIS EVENING BUT BECOME MORE
CONFINED TO THE HIGHER TERRAIN.
THERE IS ONE MORE DECENT SHORT WAVE WITH THE OFFSHORE LOW THAT HAS A
DECENT COMMA CLOUD WITH IT THAT WILL MOVE ONTO THE SOUTHERN OREGON
AND NORTHERN CALIFORNIA COASTS THROUGH THE DAY TODAY. SOME OF THIS
MOISTURE WILL ROTATE NORTHWARD INTO OUR SOUTHERN FORECAST ZONES
TONIGHT AND EARLY FRIDAY...PERHAPS AS FAR NORTH AS SALEM...PRODUCING
A FEW SHOWERS. THE BAND IS RATHER CONVECTIVE LOOKING AND WILL USE
THE SHOWER WORDING. OTHERWISE SURFACE PRESSURE GRADIENTS THROUGH THE
GORGE ARE LESS THAN 2 MB NOW AND WILL STAY WEAK INTO FRIDAY
MORNING...SO LOOK FOR MORE AREAS OF NIGHT AND MORNING FOG ESPECIALLY
IN THE VALLEYS TONIGHT AND FRIDAY. THE FOG AND LOW CLOUDS FRIDAY MAY
TAKE A WHILE TO BREAK OUT DUE TO THE LIGHT LOW LEVEL FLOW DOWN THE
VALLEY.
THE NEXT SYSTEM CONTINUES TO BE FORECAST TO APPROACH FRIDAY NIGHT...
TAKE ON A NEGATIVE TILT AS IT MOVES ONSHORE LATER FRIDAY NIGHT AND
SATURDAY. THE MODELS STILL ARE NOT EXACTLY ON THE SAME PAGE...BUT
TRENDS SUGGEST THAT THIS SYSTEM WILL STRETCH AND WEAKEN SOME AS IT
MOVES NORTH SATURDAY...WITH THE ECMWF MODEL THE SLOWEST IN THE
WEAKENING AND STRETCHING. NEVERTHELESS...SOME PRECIPITATION SHOULD
AFFECT PRETTY MUCH ALL OF OUR FORECAST AREA SATURDAY.
WITH DEWPOINTS CURRENTLY RISING INTO THE 30S...THE SLOW MODERATION
THAT IS OCCURRING...AND THAT THE EAST WIND THAT REDEVELOPS LATE
FRIDAY AND FRIDAY NIGHT IS LESS THAN WHAT WE HAD A WEEK AGO...AM
GETTING LESS BULLISH ON THE EXTENT OF WINTER WEATHER FOR THE VALLEYS
ON SATURDAY. THE MODELS TEND TO KEEP AREAS SOUTH OF PORTLAND ALL
RAIN...AND ANY FREEZING RAIN EARLY SATURDAY IN THOSE AREAS LOOKS
ISOLATED AND BRIEF. THE PARKDALE AND HOOD RIVER AREAS AROUND THE
CENTRAL GORGE LOOK TO BE ALL SNOW...WITH A MIXTURE OF SNOW OR
FREEZING RAIN IN THE WESTERN GORGE. IN PORTLAND AND VANCOUVER AREA
IT LOOKS LIKE THERE IS A CHANCE OF RAIN OR SNOW OR FREEZING RAIN...
WITH THE BEST CHANCE NEAR THE GORGE...BUT CANNOT RULE OUT THE COLDER
OUTLYING AREAS OF CLARK COUNTY AND OUT IN THE TUALATIN VALLEY FOR
AWHILE SATURDAY. ALSO BELIEVE THE COLDER SHELTERED VALLEYS OF THE
NORTH OREGON COAST RANGE ARE ALSO AT RISK...AND PERHAPS UP TOWARD
KELSO AS WELL. HAVE MADE SOME OF THESE ADJUSTMENTS IN THE MORNING
FORECAST PACKAGE...BUT WILL NEED TO FINE TUNE THIS SOME MORE IN THE
AFTERNOON PACKAGE. THIS EVENT DOES NOT LOOK TO HAVE THE WIDESPREAD
IMPACTS OF LAST SUNDAY... THOUGH IT MAY GET A LITTLE DICEY AROUND
THE COLUMBIA RIVER FOR A WHILE. TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY...IT APPEARS THE SATURDAY SYSTEM SHOULD MOVE AWAY
SUNDAY FOR DRYING. AFTER A BRIEF UPPER RIDGE...THE NEXT SYSTEM IS
EXPECTED EARLY NEXT WEEK. THE FASTER GFS MAY BE A BIT TOO FAST...AND
CURRENTLY BLENDED TOWARD THE SLOWER ECMWF. HAVE ADDED A SLIGHT CHANCE
OF FREEZING RAIN TO MUCH OF THE AREA AWAY FROM THE COAST MONDAY
MORNING BUT THIS MAY CHANGE AS THE MODELS SHIFT OVER THE COMING DAYS.
BOWEN/TOLLESON
&&
.AVIATION...PRIMARILY VFR THIS MORNING...EXCEPT FOR AREAS OF IFR/LIFR
IN THE CENTRAL AND SOUTH INTERIOR VALLEYS. DO NOT SEE MUCH CHANGE IN
OVERALL CONDITIONS THROUGH THE MORNING. SPOTTY LIGHT PRECIP MAY
RESULT IN BRIEF PERIODS OF VIS/CIG RESTRICTIONS ANYWHERE AWAY FROM
THE COLUMBIA GORGE. EXPECT VFR TO PREVAIL DURING THE AFTERNOON AND
EVENING HOURS. HOWEVER...CONTINUED EAST LOW-LEVEL FLOW THROUGH THE
GORGE WILL MAINTAIN STRATUS IN THE COLUMBIA BASIN RESULTING IN
MOUNTAIN OBSCURATION ALONG THE CASCADES AND PERSISTENT IFR IN THE
HOOD RIVER VALLEY. EXPECT AREAS OF IFR/LIFR TO RETURN TO THE CENTRAL
AND SOUTH INTERIOR VALLEYS OVERNIGHT AND INTO FRI MORNING.
KPDX AND APPROACHES...VFR TO CONTINUE THROUGH FRI MORNING.
HOWEVER...LOCAL MVFR THROUGH THE MORNING ALONG WRN APPROACHES.
OFFSHORE LOW-LEVEL GRADIENT HAS WEAKENED TO -2.0 MB AS OF 16Z. THE
GRADIENT STRENGTHENS A LITTLE TONIGHT AND FRI MORNING. DO NOT EXPECT
EAST WIND AT THE TERMINAL TODAY...BUT MAY SEE 5-10 KT OVERNIGHT INTO
FRI MORNING. WEISHAAR
&&
.MARINE...WEAK SURFACE LOW OFF THE S OREGON COAST NEAR 125W WILL
CONTINUE TO DISSIPATE AND MOVE NE TODAY. WIND SPEEDS TO REMAIN BELOW
SMALL CRAFT ADVISORY THRESHOLDS...BUT THE HRRR AND NAM INDICATE
POSSIBLE 20-25 KT GUSTS OVER THE FAR SW CORNER OF PZZ275 TODAY.
PRESSURE GRADIENTS ARE EXPECTED TO TIGHTEN A BIT TONIGHT AND FRI AS
HIGH PRESSURE STRENGTHENS EAST OF THE CASCADES AND THE NEXT TROUGH OF
LOW PRESSURE NEAR 130W SLOWLY APPROACHES FROM THE W-SW. THIS MAY
RESULT IN A FEW GUSTS TO 25 KT TONIGHT AND FRI MORNING...BUT IT DOES
NOT APPEAR TO BE ENOUGH TO WARRANT AN ADVISORY. STRONGER SYSTEM
IMPACTS THE WATERS FRI NIGHT AND SAT...LIKELY REQUIRING A SMALL CRAFT
ADVISORY FOR WIND...ESPECIALLY OVER THE OUTER WATERS.
WAVE GUIDANCE DID A PRETTY GOOD JOB INDICATING THE HIGHER SEAS
OVERNIGHT INTO THE MORNING HOURS. SEAS LOOK TO BE RUNNING ABOUT A
FOOT HIGHER THAN THE ENP MODEL AND HAVE ADJUSTED THE TODAY AND
TONIGHT WAVE HEIGHT FORECASTS ACCORDINGLY. SEAS STAY ABOVE 10 FT
THROUGH EARLY FRI MORNING. THE LARGE/LONG PERIOD SWELL WILL RESULT IN
ROUGH COLUMBIA RIVER BAR CONDITIONS WITH BREAKERS DURING THE EBBS.
WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM PST FRIDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
6 AM PST FRIDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
936 PM PST WED JAN 6 2016
.SYNOPSIS...A BROAD COMPLEX LOW WILL REMAIN OFF THE COAST TONIGHT AND
THURSDAY BEFORE MOVING SOUTHEAST AND WEAKENING BY FRIDAY. THIS
FEATURE MAY SPREAD SOME LIGHT PRECIPITATION INTO NORTHWEST OREGON AND
SOUTHWEST WASHINGTON AT TIMES INTO THURSDAY...BUT THERE WILL ALSO BE
CONSIDERABLE DRY PERIODS. COOL OFFSHORE FLOW WILL CONTINUE AS WELL.
ADDITIONAL LIGHT ICING MAY OCCUR AROUND THE COLUMBIA RIVER GORGE.
FRIDAY IS LOOKING GENERALLY DRY. ANOTHER SYSTEM HEADING TOWARD
NORTHERN CALIFORNIA WILL MORE THAN LIKELY SPREAD SOME MOISTURE
NORTHWARD AGAIN INTO OUR FORECAST AREA LATE FRIDAY NIGHT THROUGH
SATURDAY THAT COULD RESULT IN ANOTHER WINTER MIX OF PRECIPITATION
INLAND...POSSIBLY LINGERING INTO EARLY SUNDAY. THE NEXT SYSTEM IS NOT
EXPECTED UNTIL THE EARLY OR MIDDLE PART OF NEXT WEEK.
&&
.SHORT TERM...TONIGHT THROUGH SATURDAY...A BROAD AREA OF LOW PRES
CURRENTLY STRETCHES FROM THE BRITISH COLUMBIA COAST DOWN ALONG MOST
OF THE U.S. WEST COAST. OUT AHEAD OF THE MAIN TROUGH AXIS...THERE IS
A BAND OF INCREASED MOISTURE AND LIGHT PRECIPITATION DRAPED OVER THE
CENTRAL AND SOUTHERN WILLAMETTE VALLEY INTO THE LANE COUNTY CASCADES
THIS EVENING. THIS BAND APPEARS TO BE THE REMAINS OF AN OLD OCCLUDED
FRONT...AND MAY BE GETTING SOME ADDITIONAL ENHANCEMENT FROM A WEAK
DEFORMATION ZONE. THE FCST MODELS SEEM TO HAVE KEYED IN ON THIS
FEATURE REASONABLY WELL...PARTICULARLY THE 04Z RUN OF THE HRRR MODEL.
BASED ON THE LATEST MODEL TRENDS...EXPECT THIS BAND TO SLOWLY LIFT
NORTH LATER THIS EVENING AND OVERNIGHT...BEFORE DISSIPATING EARLY THU
MORNING OVER FAR NW OREGON. EXPECT LITTLE TO NO PRECIPITATION
FURTHER NORTH OVER OUR SW WASHINGTON ZONES. TEMPERATURES REMAIN IN
THE 35 TO 40 DEG F AT CURRENT THROUGH MOST OF THE REGION...WITH DEW
POINTS ABOVE 32 DEG AS WELL. THERE IS ALSO QUITE A BIT OF CLOUD COVER
OVER THE REGION TO PREVENT EXTENSIVE RADIATIONAL COOLING. SO
PRECIPITATION SHOULD FALL AS LIGHT RAIN FOR MOST LOCATIONS TONIGHT.
HOWEVER...EAST WINDS CONTINUE THROUGH THE GORGE AND LOCATIONS AROUND
THE WEST END OF THE GORGE MAY POTENTIALLY SEE SOME ADDITIONAL LIGHT
ICING. PRECIPITATION LIKELY TO REMAIN SNOW IN THE CENTRAL GORGE AND
UPPER HOOD RIVER VALLEY. VERY LIGHT PRECIPITATION MAY CONTINUE AT
TIMES THROUGH THU NIGHT.
THE OFFSHORE LOW IS FORECAST TO SHEAR OUT TO THE SOUTH OF OUR AREA BY
FRIDAY...AND OUR FORECAST AREA SHOULD BE MOSTLY DRY THEN. EAST WINDS
ARE FORECAST BY ALL OF THE MODELS TO EASE UP THURSDAY AND FRIDAY AS
WELL. AREAS OF FOG THURSDAY NIGHT AND FRIDAY MIGHT BE A BIT SLOW TO
CLEAR OUT FRIDAY AFTERNOON UNDER THE WEAK SURFACE GRADIENTS.
ATTENTION THEN TURNS TO THE NEXT SYSTEM. THE MODELS APPEAR TO FINALLY
BE CONVERGING ON A SOLUTION FOR LATER FRIDAY NIGHT AND SATURDAY.
WHILE THE BULK OF THE ENERGY WITH THIS NEXT SYSTEM IS HEADED TOWARD
CALIFORNIA...SOME OF THE MOISTURE IS FORECAST TO SPREAD NORTH AS A
DEFORMATION ZONE LATE FRIDAY NIGHT AND ESPECIALLY ON SATURDAY. THE
MODELS ARE TRENDING TOWARD LIQUID EQUIVALENT PRECIPITATION AMOUNTS
CLOSE TO THOSE THIS PAST SUNDAY. THE MODELS ARE ALSO SHOWING
INCREASING EAST WINDS AS THE ASSOCIATED DECENTLY DEEP SURFACE LOW
APPROACHES THE OREGON COAST. THIS WILL SET THE STAGE FOR A WINTRY MIX
OF PRECIPITATION INLAND AGAIN. IT IS A BIT EARLY TO BE TOO CONFIDENT
ON THE DETAILS YET...BUT THERE IS A RISK OF SOME TRAVEL DISRUPTIONS
AGAIN. IF THE LOW MOVES NORTH ALONG THE COAST BY LATER SATURDAY AND
SATURDAY NIGHT...THERE COULD BE SOME MODERATING SOUTHERLY WINDS
MOVING UP THE VALLEY...THOUGH AREAS NEAR THE GORGE MAY BE VERY SLOW
TO CHANGE MUCH. PYLE/TOLLESON
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...IT APPEARS THE
SATURDAY SYSTEM SHOULD MOVE AWAY SUNDAY FOR DRYING. AFTER A BRIEF
UPPER RIDGE...THE NEXT SYSTEM IS EXPECTED EARLY NEXT WEEK. THE FASTER
GFS MAY BE A BIT TOO FAST...AND CURRENTLY BLENDED TOWARD THE SLOWER
ECMWF. WILL HAVE TO MONITOR PRECIPITATION TYPE AS WE GET CLOSER TO
THE SYSTEMS NEXT WEEK AS THAT IS UNCLEAR AT THE MOMENT. TOLLESON
&&
.AVIATION...PRIMARILY VFR CONDITIONS EXPECTED TONIGHT WITH LOCAL
MVFR TO IFR CONDITIONS IN FOG/STRATUS FOR THE LOWER COLUMBIA RIVER
AND SOUTH WILLAMETTE VALLEY. LIGHT PRECIPITATION EXPECTED AS IMPULSES
CONTINUE TO ROTATE AROUND A BROAD ERN PAC LOW THROUGH THU MIDDAY.
MAIN FORECAST CHALLENGE WILL BE THE EXTENT OF VALLEY IFR/LIFR
COVERAGE TONIGHT THROUGH THU MORNING. SATELLITE IMAGERY SHOWS
CONSIDERABLE MID AND HIGH LEVEL CLOUDS MOVING INTO THE FORECAST
AREA...WHICH WOULD TEND TO INHIBIT OR REDUCE STRATUS AND FOG
FORMATION. MAY SEE SOME SCT-BKN CLOUD DECK DEPICTED BY GFS AND
NAM 13Z-20Z THU.
KPDX AND APPROACHES...VFR PREVAILING WITH INTERMITTENT LIGHT RAIN
THROUGH THU MORNING. EXPECT AREAS OF IFR/LIFR ALONG WRN
APPROACHES THROUGH THU MORNING. WEISHAAR /MH
&&
.MARINE...WIND SPEEDS CONTINUE TO DIMINISH THIS EVENING...BUT NEW
MODELS SHOW STRONGER WINDS OVER THE OUTER WATERS THU. SO HAVE
INCREASED WINDS BUT KEPT IT BELOW ADVISORY CRITERIA FOR NOW.
OFFSHORE GRADIENT INCREASES FRI THROUGH SAT AND HAVE INCREASED
WIND SPEEDS TO 15-20 KT. MODELS STARTING TO COME MORE IN LINE
DEVELOPING A 1004MB LOW OFF THE S OREGON COAST 12Z SAT. THIS
SHOULD PRODUCE SMALL CRAFT ADVISORY WIND SAT. ANOTHER ROUND OF
INCREASED WIND IS EXPECTED EARLY NEXT WEEK...POSSIBLY RESULTING IN
GALE FORCE WIND GUSTS.
HAVE EXTENDED THE SMALL CRAFT ADVISORY FOR SEAS THROUGH 00Z
FRI. SEAS WILL CONTINUE TO SUBSIDE A BIT THROUGH THIS EVENING...BUT
THEN BUILD TO 13 TO 16 FT RANGE OVERNIGHT INTO THU MORNING. LATEST
GUIDANCE SHOWS SEAS OF 15-20 FT EARLY NEXT WEEK. HAVE GONE
SLIGHTLY UNDER THE ENP GUIDANCE FOR NOW. WEISHAAR /MH
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM
PST THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR
UNTIL 4 PM PST THURSDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1016 PM EST FRI JAN 8 2016
.SYNOPSIS...
A LIGHT COATING OF FREEZING RAIN IS POSSIBLE OVER THE MOUNTAINS
TONIGHT AS WARMER AIR SPREADS ACROSS THE REGION. A STRONG LOW
PRESSURE SYSTEM WILL TAKE A PATH WEST AND NORTH OF PENNSYLVANIA
SATURDAY NIGHT INTO EARLY SUNDAY. AN UPPER LEVEL TROUGH WILL THEN
PIVOT THROUGH THE NORTHEAST CONUS DURING THE FIRST HALF OF NEXT
WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
10 PM UPDATE...
A COUPLE OF MORE WAVES OF SHOWERS /SCT COVG/ CONTINUE TO MOVE
INTO THE AREA FROM THE SW. MANY OF THE POPULATED AREAS ARE ABOVE
FREEZING. HOWEVER...THE HIGH ELEVATIONS IN THE
LAURELS...ALLEGHENIES AND NORTHEAST MOUNTAINS ARE AOB FREEZING.
WHILE IT IS STILL EXPECTED TO WARM UP A DEG OR TWO
OVERNIGHT...LATEST HRRR AND RAP SFC TEMPS REMAIN BELOW FZG IN THE
HIGHER ELEVS THRU 10Z. LWX HAS EXTENDED THEIR ADVY INTO THE
MORNING...AND HAVE WE HAVE CHOSEN TO EXTEND THE ADVY SEGMENT WHICH
COVERS THE MAJORITY OF CENTRAL PA THROUGH 10Z AS WELL. THUS...ALL
THE FZRA ADVY NOW GOES UNTIL 10Z.
PREV...
CLOUDS WILL CONTINUE TO THICKEN ACROSS THE REGION AHEAD OF A WARM
FRONT THAT WILL BRING SOME LIGHT SHOWERS AND FREEZING RAIN THIS
EVENING. TEMPERATURES ARE CURRENTLY IN THE UPPER 30S ACROSS THE
SOUTHERN PIEDMONT AND SUSQUEHANNA VALLEY. ACROSS THE CENTRAL AND
NORTHERN MOUNTAINS TEMPERATURES HAVE STRUGGLED TO RISE TODAY AND
ARE CURRENTLY IN THE UPPER 20S. THIS HAS LED TO A CONCERN FOR
FREEZING RAIN THIS EVENING...AND WE HAVE ISSUED A FREEZING RAIN
ADVISORY FOR THESE AREAS. HIGH TEMPERATURES IN THE MOUNTAINS WILL
STRUGGLE TO REACH THE FREEZING POINT AND WILL QUICKLY COOL WHEN
PRECIPITATION ARRIVES FROM EVAPORATIONAL COOLING DUE TO THE LOW
DEW POINTS FOR THESE LOCATIONS.
THE OTHER STORY TODAY HAS BEEN THE PERSISTENT FOG AND MIST OVER
THE EXTREME SOUTHERN SUSQUEHANNA VALLEY. EVERYWHERE BUT YORK HAS
LIFTED ABOVE A MILE VISIBILITY BUT THE FOG WILL REASSERT ITSELF
LATER THIS EVENING WHEN IT STARTS RAINING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH 6 PM SATURDAY/...
RAIN SHOULD BEGIN TO FALL AROUND 7 PM OVER THE LAUREL HIGHLANDS
AND NORTHWEST MOUNTAINS AND WILL SPREAD EASTWARD FROM THERE. OVER
THE MOUNTAINS THE RAIN WILL FALL AS FREEZING RAIN AND WILL ACCUMULATE
UP TO A FEW HUNDREDTHS OF AN INCH BEFORE TEMPERATURES WARM ABOVE
FREEZING. FARTHER EAST...ESPECIALLY
CLINTON...POTTER...TIOGA...LYCOMING...AND SULLIVAN
COUNTIES...TEMPERATURES MAY NOT RISE ABOVE FREEZING DURING THE
LIGHT RAIN AND ICE COULD ACCUMULATE BETWEEN A TENTH AND TWO
TENTHS.
NO SIG RAIN EXPECTED DURING SATURDAY...AS UPPER LVL RIDGING
BUILDS OVR THE REGION. HOWEVER...A MOIST SERLY FLOW WILL YIELD
LINGERING LOW CLOUDS AND SPOTTY DRIZZLE. SUPERBLEND INDICATES
TEMPS ONLY SLOWLY RISING TO BTWN 40-45F.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
A POTENT SOUTHERN STREAM SHORTWAVE AND ASSOC SFC LOW WILL TRACK
WEST OF PA SAT NIGHT/EARLY SUNDAY. A PERIOD OF STEADY/MODERATE
RAIN IS EXPECTED SATURDAY NIGHT INTO SUNDAY MORNING AS ANOMALOUS
SERLY LL JET/PWAT PLUME LIFTS THRU. GEFS MFLUX VALUES TOP OUT ARND
3SD ABV CLIMO EARLY SUN AM. MDL CONSENSUS RAINFALL AMOUNTS ARE
CLOSE TO 1 INCH OVER MUCH OF CENTRAL PA BY THE TIME IT TAPERS OFF
LATE SUNDAY MORNING.
ABOVE NORMAL TEMPERATURES EXPECTED SUNDAY...AS THE REGION BRIEFLY
BREAKS INTO WARM SECTOR SOUTH OF SFC LOW. HOWEVER...MUCH COLDER
AIR WILL ARRIVE VIA GUSTY WEST WINDS BEHIND THE COLD FRONT LATER
SUNDAY INTO EARLY MONDAY. A BAND OF FRONTAL RAIN SHOWERS WILL
LIKELY END AS A PERIOD OF SNOW SHOWERS OVER THE ALLEGHENIES SUNDAY
PM.
A PERSISTENT COLD WESTERLY FLOW PATTERN SHOULD SUPPORT PERIODS OF
LAKE EFFECT AND OROGRAPHIC SNOW SHOWERS THROUGH THE MIDDLE OF NEXT
WEEK. SNOW ACCUMULATION IS PROBABLE DOWNWIND OF LAKE ERIE AND OVER
THE RIDGES IN SOUTHWEST PENNSYLVANIA. TEMPERATURES SHOULD AVERAGE
BELOW NORMAL WITH SINGLE DIGITS WIND CHILLS LIKELY OVER THE
ALLEGHENIES.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
FREEZING RAIN...COMING FROM A SHORT WAVE TROUGH MOVING THROUGH THE
MID ATLANTIC CONTINUES TO AFFECT CENTRAL PA TONIGHT. IFR CIGS AND
VSBYS PERSIST ACROSS THE WESTERN HALF OF CENTRAL PENNSYLVANIA.
AREAS TO THE EAST...THOUGH SEEING MVFR CIGS AND LIGHT
RAIN...REMAIN ABOVE FREEZING. WINDS OUT WEST HAVE SHIFTED TO THE
SOUTH EAST...WITH CALM WINDS THROUGH CENTRAL TAF SITES...AND
EASTERLY WINDS OUT EAST. AS THE SHOWERS CONTINUE TO MOVE TO THE
NORTHEAST...EXPECT CIG AND VSBYS TO DEGRADE AT IPT AND WINDS TO
GRADUALLY SHIFT TO THE SOUTH EAST ACROSS THE REGION OVERNIGHT.
BEHIND THE FIRST SUBSTANTIAL ROUND OF FREEZING PRECIPITATION...ANY
PRECIPITATION WILL BE LIGHT. EXPECT REDUCING CIGS AND VSBYS TO
PERSIST WELL INTO TOMORROW BEFORE IMPROVING TOMORROW AFTERNOON
BRIEFLY...AND THEN DEGRADING AGAIN TOMORROW EVENING.
RESTRICTIONS WILL PERSIST THROUGH THE WEEKEND UNTIL NEXT SYSTEM
MOVES THROUGH ON SUNDAY...WHEN FLOW WILL TURN WESTERLY /AND BE
QUITE STRONG/ WITH RESTRICTIONS BECOMING CONFINED TO WESTERN
HIGHER TERRAIN.
OUTLOOK...
SAT...LOW CIGS CONTINUE. AREAS OF DRIZZLE POSSIBLE.
SAT NIGHT...LOW CIGS. AREAS OF RAIN. LLWS LIKELY.
SUN...AM RAIN/LOW CIGS POSSIBLE. TURNING QUITE WINDY WITH PM
SHSN/BRIEF VIS REDUCTIONS POSSIBLE KBFD/KJST. WESTERLY WIND GUSTS
ACROSS CENTRAL AND WRN PENN POSSIBLY TOPPING 40 KTS AT TIMES.
MON...A FEW LOCALIZED BANDS OF LOW CIGS AND VSBYS IN SNOW SHOWERS
ACROSS THE LAUREL HIGHLANDS AND NW MTNS. OTHERWISE...QUITE BREEZY
WITH NO WIDESPREAD SIG WX RESTRICTIONS EXPECTED.
TUE...CIG REDUCTIONS LIKELY NW HALF IN SNOW SHOWERS. VFR
ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 5 AM EST SATURDAY FOR PAZ005-006-
010>012-017>019-024>028-033>035-037-041-042-045-046-049-050.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/KEARNS
SHORT TERM...FITZGERALD/KEARNS
LONG TERM...FITZGERALD/GARTNER
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1139 AM CST THU JAN 7 2016
.UPDATE...
UPDATED FOR THE 18Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 1105 AM CST THU JAN 7 2016/
UPDATE...
A SHORTWAVE WILL CONTINUE TO MOVE EAST ACROSS THE MIDSOUTH THIS
AFTERNOON. A LINE OF SHOWERS ASSOCIATED WITH THE SHORTWAVE
CURRENTLY STRETCHES FROM CLARKSDALE MISSISSIPPI TO WEST PLAINS
MISSOURI. THE LATEST HRRR SHOWS THIS LINE BREAKING UP AS IT PUSHES
EAST. THIS IS LIKELY DUE TO THE DRY AIR THAT REMAINS IN PLACE OVER
THE AREA. THUS WILL UPDATE TO LOWER POPS.
KRM
DISCUSSION... /ISSUED 404 AM CST THU JAN 7 2016/
SYNOPSIS... MULTIPLE SUCCESSIVE SHORTWAVES WILL TRAVERSE THE MID-
SOUTH OVER THE NEXT SEVERAL DAYS. CLOUDY CONDITIONS AND PERIODS OF
RAIN WILL BE POSSIBLE ALONG WITH SOME THUNDERSTORMS. TEMPERATURES
WILL REMAIN ABOVE NORMAL THROUGH THIS PERIOD BEFORE A MAJOR
COOLDOWN BEGINS SUNDAY AND CONTINUES INTO EARLY NEXT WEEK.
CURRENTLY...AS OF 3AM...
TEMPERATURES ACROSS THE MID-SOUTH RANGE FROM THE MID TO UPPER 20S
ALONG THE TENNESSEE RIVER VALLEY TO THE UPPER 30S WESTWARD. LIGHT
WAA SHOWERS WERE NOTED ON RADAR THIS MORNING...PREDOMINANTLY WEST
OF THE MISSISSIPPI RIVER. LATEST WATER VAPOR IMAGERY SHOWS TWO
DISTINCT SHORTWAVES...WITH ONE LOCATED OVER EAST TEXAS AND THE
OVER SOUTHERN CALIFORNIA. BOTH WAVES ARE PRODUCING CONVECTION AT
THIS HOUR...WITH MODERATE LIGHTNING BEING DETECTED.
SHORT TERM...TODAY THROUGH EARLY SUNDAY MORNING...
AN ACTIVE SOUTHERN BRANCH JET STREAM WILL HEAVILY INFLUENCE OUR
WEATHER THROUGH THIS PERIOD...BRINGING US PERIODS OF RAIN AND SOME
THUNDERSTORMS THROUGH EARLY SUNDAY. A SHORTWAVE LOCATED TO OUR
SOUTHWEST THIS MORNING...WILL LIFT NORTHEAST ACROSS THE
MISSISSIPPI VALLEY THROUGH EARLY FRIDAY MORNING. AS IT DOES...RAIN
WILL OVERSPREAD THE MID-SOUTH. SOME ELEVATED INSTABILITY OVER
NORTH MISSISSIPPI MAY RESULT IN A FEW RUMBLES OF THUNDER THIS
AFTERNOON. TEMPERATURES WILL WARM INTO THE UPPER 40S IN THE
NORTH...WITH MIDDLE 50S TO THE SOUTH. THE AFOREMENTIONED WAVE
WILL LIFT NORTH OF OUR AREA BY FRIDAY AFTERNOON...BRINGING AN END
TO ANY WIDESPREAD RAIN. TEMPERATURES WILL WARM INTO THE 60S
AREAWIDE ON FRIDAY AND WE MAY EVEN SEE A FEW PEEKS OF SUNSHINE
BETWEEN PASSING CLOUDS.
BY FRIDAY NIGHT...A DEEPER AND MORE ROBUST SHORTWAVE WILL DIG
ACROSS THE SOUTHERN PLAINS. AS IT DOES...WEAK CYCLOGENESIS IS
EXPECTED TO OCCUR NEAR THE ARKLAMISS AREA. THE LOW PRESSURE SYSTEM
IS EXPECTED TO TRACK NORTHEAST ACROSS THE MID-SOUTH BY EARLY
SATURDAY AFTERNOON...SPREADING SHOWERS AND THUNDERSTORMS ACROSS
THE AREA. DEWPOINTS AHEAD OF THE SYSTEM LOOK MEAGER AT BEST WITH
VALUES BARELY REACHING INTO THE LOWER 50S IN THE WARM SECTOR OVER
NORTH MISSISSIPPI. HOWEVER...ALL MODELS CONTINUE TO GENERATE
MODEST AMOUNTS OF INSTABILITY OVER THE REGION...WITH ANYWHERE FROM
300 TO 1200 J/KG OF SBCAPE. THE LARGE RANGE SUGGESTS THAT ALL
MODELS ARE HAVING A HARD TIME ESTABLISHING A CLEAR WARM SECTOR
OVER THE REGION BEFORE THE COLD FRONT MOVES THROUGH. NONETHELESS...A
FEW ELEVATED STRONG THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
ENTIRE REGION AS LIFT BECOMES ENHANCED OVER THE REGION DUE TO A
120 MID LEVEL JET ROTATING THROUGH. WILL CONTINUE TO ADVERTISE A
FEW STRONG STORMS POSSIBLE IN THE HWO.
THE STRONG ARCTIC COLD FRONT WILL SWING THROUGH QUICKLY BY
SATURDAY NIGHT...AND ANY LINGERING MOISTURE OVER NORTHERN PARTS OF
WEST TENNESSEE COULD CHANGE OVER TO SNOW OR FLURRIES FOR A BRIEF
HOUR OR SO WITH NO ACCUMULATION EXPECTED. BEHIND THE FRONT...THE
COLDEST AIR OF THIS WINTER THUS FAR WILL ARRIVE AS ARCTIC HIGH
PRESSURE BUILDS IN AT THE SURFACE.
LONG TERM...SUNDAY THROUGH EARLY NEXT...
COLD AND QUIET WEATHER WILL BE THE STORY THROUGH THIS PERIOD.
HIGHS WILL ONLY REACH INTO THE UPPER 30S FOR SUNDAY AND
MONDAY...WITH A GRADUAL MODERATION OF TEMPERATURES THROUGH
MIDWEEK. A SHOT OF REINFORCING COLD AIR WILL OCCUR TUESDAY NIGHT
AS A DRY COLD FRONT MOVES THROUGH.
AC3
&&
.AVIATION...
18Z TAF CYCLE
LOW CLOUDS HAVE MOVED INTO SOUTHERN SECTIONS OF THE FORECAST AREA
AND THESE CLOUDS WILL CONTINUE TO SLOWLY MOVE ACROSS THE REMAINDER
OF THE REGION THIS AFTERNOON AND TONIGHT. LIGHT RAIN IS SLOWLY
MOVING INTO FAR WESTERN SECTIONS AND WILL CONTINUE TO MOVE SLOWLY
EAST THIS AFTERNOON AND TONIGHT. WINDS WILL BE MAINLY FROM THE
SOUTHEAST AT 5 T0 10 KNOTS THIS AFTERNOON AND THEN SHIFT TO THE
SOUTH TONIGHT AT AROUND 10 KNOTS TONIGHT AND WILL CONTINUE THROUGH
FRIDAY MORNING.
ARS
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1105 AM CST THU JAN 7 2016
.UPDATE...
A SHORTWAVE WILL CONTINUE TO MOVE EAST ACROSS THE MIDSOUTH THIS
AFTERNOON. A LINE OF SHOWERS ASSOCIATED WITH THE SHORTWAVE
CURRENTLY STRETCHES FROM CLARKSDALE MISSISSIPPI TO WEST PLAINS
MISSOURI. THE LATEST HRRR SHOWS THIS LINE BREAKING UP AS IT PUSHES
EAST. THIS IS LIKELY DUE TO THE DRY AIR THAT REMAINS IN PLACE OVER
THE AREA. THUS WILL UPDATE TO LOWER POPS.
KRM
&&
.DISCUSSION... /ISSUED 404 AM CST THU JAN 7 2016/
SYNOPSIS... MULTIPLE SUCCESSIVE SHORTWAVES WILL TRAVERSE THE MID-
SOUTH OVER THE NEXT SEVERAL DAYS. CLOUDY CONDITIONS AND PERIODS OF
RAIN WILL BE POSSIBLE ALONG WITH SOME THUNDERSTORMS. TEMPERATURES
WILL REMAIN ABOVE NORMAL THROUGH THIS PERIOD BEFORE A MAJOR
COOLDOWN BEGINS SUNDAY AND CONTINUES INTO EARLY NEXT WEEK.
CURRENTLY...AS OF 3AM...
TEMPERATURES ACROSS THE MID-SOUTH RANGE FROM THE MID TO UPPER 20S
ALONG THE TENNESSEE RIVER VALLEY TO THE UPPER 30S WESTWARD. LIGHT
WAA SHOWERS WERE NOTED ON RADAR THIS MORNING...PREDOMINANTLY WEST
OF THE MISSISSIPPI RIVER. LATEST WATER VAPOR IMAGERY SHOWS TWO
DISTINCT SHORTWAVES...WITH ONE LOCATED OVER EAST TEXAS AND THE
OVER SOUTHERN CALIFORNIA. BOTH WAVES ARE PRODUCING CONVECTION AT
THIS HOUR...WITH MODERATE LIGHTNING BEING DETECTED.
SHORT TERM...TODAY THROUGH EARLY SUNDAY MORNING...
AN ACTIVE SOUTHERN BRANCH JET STREAM WILL HEAVILY INFLUENCE OUR
WEATHER THROUGH THIS PERIOD...BRINGING US PERIODS OF RAIN AND SOME
THUNDERSTORMS THROUGH EARLY SUNDAY. A SHORTWAVE LOCATED TO OUR
SOUTHWEST THIS MORNING...WILL LIFT NORTHEAST ACROSS THE
MISSISSIPPI VALLEY THROUGH EARLY FRIDAY MORNING. AS IT DOES...RAIN
WILL OVERSPREAD THE MID-SOUTH. SOME ELEVATED INSTABILITY OVER
NORTH MISSISSIPPI MAY RESULT IN A FEW RUMBLES OF THUNDER THIS
AFTERNOON. TEMPERATURES WILL WARM INTO THE UPPER 40S IN THE
NORTH...WITH MIDDLE 50S TO THE SOUTH. THE AFOREMENTIONED WAVE
WILL LIFT NORTH OF OUR AREA BY FRIDAY AFTERNOON...BRINGING AN END
TO ANY WIDESPREAD RAIN. TEMPERATURES WILL WARM INTO THE 60S
AREAWIDE ON FRIDAY AND WE MAY EVEN SEE A FEW PEEKS OF SUNSHINE
BETWEEN PASSING CLOUDS.
BY FRIDAY NIGHT...A DEEPER AND MORE ROBUST SHORTWAVE WILL DIG
ACROSS THE SOUTHERN PLAINS. AS IT DOES...WEAK CYCLOGENESIS IS
EXPECTED TO OCCUR NEAR THE ARKLAMISS AREA. THE LOW PRESSURE SYSTEM
IS EXPECTED TO TRACK NORTHEAST ACROSS THE MID-SOUTH BY EARLY
SATURDAY AFTERNOON...SPREADING SHOWERS AND THUNDERSTORMS ACROSS
THE AREA. DEWPOINTS AHEAD OF THE SYSTEM LOOK MEAGER AT BEST WITH
VALUES BARELY REACHING INTO THE LOWER 50S IN THE WARM SECTOR OVER
NORTH MISSISSIPPI. HOWEVER...ALL MODELS CONTINUE TO GENERATE
MODEST AMOUNTS OF INSTABILITY OVER THE REGION...WITH ANYWHERE FROM
300 TO 1200 J/KG OF SBCAPE. THE LARGE RANGE SUGGESTS THAT ALL
MODELS ARE HAVING A HARD TIME ESTABLISHING A CLEAR WARM SECTOR
OVER THE REGION BEFORE THE COLD FRONT MOVES THROUGH. NONETHELESS...A
FEW ELEVATED STRONG THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
ENTIRE REGION AS LIFT BECOMES ENHANCED OVER THE REGION DUE TO A
120 MID LEVEL JET ROTATING THROUGH. WILL CONTINUE TO ADVERTISE A
FEW STRONG STORMS POSSIBLE IN THE HWO.
THE STRONG ARCTIC COLD FRONT WILL SWING THROUGH QUICKLY BY
SATURDAY NIGHT...AND ANY LINGERING MOISTURE OVER NORTHERN PARTS OF
WEST TENNESSEE COULD CHANGE OVER TO SNOW OR FLURRIES FOR A BRIEF
HOUR OR SO WITH NO ACCUMULATION EXPECTED. BEHIND THE FRONT...THE
COLDEST AIR OF THIS WINTER THUS FAR WILL ARRIVE AS ARCTIC HIGH
PRESSURE BUILDS IN AT THE SURFACE.
LONG TERM...SUNDAY THROUGH EARLY NEXT...
COLD AND QUIET WEATHER WILL BE THE STORY THROUGH THIS PERIOD.
HIGHS WILL ONLY REACH INTO THE UPPER 30S FOR SUNDAY AND
MONDAY...WITH A GRADUAL MODERATION OF TEMPERATURES THROUGH
MIDWEEK. A SHOT OF REINFORCING COLD AIR WILL OCCUR TUESDAY NIGHT
AS A DRY COLD FRONT MOVES THROUGH.
AC3
&&
.AVIATION...
12Z TAFS
CHANGES EXPECTED THIS TAF CYCLE AS DISTURBANCE LIFTS THROUGH. VFR
CIGS WILL PERSIST THROUGH THE MORNING...WITH A THREAT FOR MVFR AT
TUP BEFORE NOON. THIS AFTERNOON/EVENING AS RAIN BAND LIFTS NORTH
CIGS WILL LOWER TO MVFR AND IFR THROUGH THE REMAINING TAF PERIOD.
EAST TO SOUTHEAST WINDS AT 3-7 KTS WILL INCREASE TO 7-9 KTS.
JAB
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
840 PM PST WED JAN 6 2016
.SYNOPSIS...A WEAKENING UPPER LOW IN THE SOUTHERN WASHINGTON
OFFSHORE WATERS WILL SLIDE SOUTHEAST INTO OREGON LATE THURSDAY AS IT
DISSIPATES. AN UPPER HIGH OVER THE YUKON WILL MERGE WITH A RIDGE
WELL OFFSHORE THEN SHIFT EAST ACROSS THE AREA ON FRIDAY NIGHT.
ANOTHER LOW WILL MOVE BY WELL TO THE SOUTH OF THE AREA OVER THE
WEEKEND.
&&
.SHORT TERM...A RATHER TYPICAL EL NINO JANUARY PATTERN APPEARS TO BE
TAKING HOLD ACROSS THE WEST. A STRONG JET STREAM IS AIMED IN AT FAR
SOUTHERN CALIFORNIA TAKING STORMS INLAND WELL SOUTH OF OUR AREA.
WESTERN WASHINGTON WILL BE DOMINATED BY A COMBINATION OF WEAK AND
DISSIPATING SPLITTING SYSTEMS AND UPPER RIDGES.
THE FIRST OLD UPPER LOW IS CENTERED NEAR 47N 131W THIS EVENING. IT
WILL WOBBLE AROUND TONIGHT THEN DISSIPATE AS IT MOVES INTO WEST
CENTRAL OREGON ON THURSDAY. CLOUDS WRAPPING AROUND THIS CIRCULATION
EXTEND NORTHWARD TO AROUND A SEATTLE-FORKS LINE. THE PRESENCE OF
THESE CLOUDS DOES NOT APPEAR TO BE INHIBITING FOG FORMATION MUCH
THIS EVENING WITH TACOMA...SHELTON...OLYMPIA...AND CHEHALIS ALL
FOGGED IN AT 8 PM. FOG IS ALSO BEING REPORTED AT PORT TOWNSEND AND
SHOULD BE FORMING IN TYPICALLY FOGGY VALLEY LOCATIONS EAST OF
INTERSTATE 5 FROM ABOUT ARLINGTON SOUTHWARD BY MIDNIGHT. AN UPDATE
FOR AREAS OF FOG TONIGHT AND PATCHY FOG THURSDAY MORNING ACROSS
PORTIONS OF THE INTERIOR WAS ISSUED EARLIER. WHILE TEMPERATURES HAVE
ALREADY COOLED TO NEAR THEIR FORECAST LOW VALUES IN THE SOUTH
INTERIOR...FOG AND CLOUDS SHOULD INBIBIT ADDITIONAL COOLING.
CLOUDS WILL WRAP AROUND THE OFFSHORE LOW ON THURSDAY RESULTING IN A
MOSTLY CLOUDY DAY OVER THE SOUTHERN HALF OF THE FORECAST AREA. WITH
THE ADDED CLOUD COVER...EXPECT IT TO BE COOLER WITH HIGHS IN THE
LOWER TO MID 40S...INSTEAD OF THE INCREDIBLE SPRING-LIKE LOWER TO
MID 50S WE SAW TODAY IN THE SEATTLE AREA.
A WEAK UPPER LEVEL RIDGE WILL SHIFT INLAND THURSDAY NIGHT INTO
FRIDAY FOR DRY AND STABLE CONDITIONS. IT CONTINUES TO APPEAR THAT WE
WILL SEE SOME CLEARING FRIDAY AFTERNOON. ANOTHER WEAK UPPER LEVEL
LOW WILL MOVE INLAND AROUND THE SOUTH OREGON COAST SATURDAY
AFTERNOON. MOISTURE WRAPPING AROUND THIS LOW WILL MOVE NORTHWARD
INTO FAR SOUTHERN WASHINGTON SATURDAY AFTERNOON...BUT IT APPEARS
THAT THE FORECAST AREA SHOULD REMAIN DRY WITH ONLY OCCASIONAL MID
AND HIGH LEVEL CLOUDS.
AS MENTIONED EARLIER...A SHORT TERM UPDATE WAS ISSUED TO INCREASE
THE AREAL COVERAGE AND EXTENT OF FOG TONIGHT AND THURSDAY MORNING.
OTHERWISE THE FORECAST IS ON TRACK AND NO FURTHER UPDATES ARE
EXPECTED. ALBRECHT
.LONG TERM...FROM THE PREVIOUS LONG TERM DISCUSSION...AN UPPER LEVEL
RIDGE WILL KEEP THE WEATHER OVER WESTERN WA DRY THROUGH THE REST OF
THE WEEKEND. THE RIDGE MAY BREAK DOWN MONDAY NIGHT OR TUESDAY AS A
TROUGH ARRIVES. WEAK SYSTEMS WILL BRING A CHANCE OF RAIN THROUGH THE
END OF THE WEEK. TEMPERATURES ARE NEAR NORMAL THROUGH THE PERIOD. 33
&&
.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED FOR THE NEXT 7 DAYS.
&&
.AVIATION...UNDER A RELATIVE AREA OF HIGH PRESSURE ALOFT...BUT IT IS
MORE OF A COL BETWEEN AN UPPER TROUGH OVER THE CANADIAN PROVINCES
AND AN UPPER TROUGH OFF THE WEST COAST OF NORTH AMERICA.
AS A RESULT...LIGHT AND VARIABLE FLOW ALOFT. EASING OF EASTERLY
SURFACE WINDS WILL HELP THE AIR MASS MOISTEN A BIT OVER THE NEXT 24
HOURS. PLENTY OF DENSE FOG OBS OVER THE SOUTH SOUND AND SW INTERIOR
RIGHT NOW. MID-LEVEL CLOUDS WILL INHIBIT EXPANSION OF THE FOG...BUT
ANY BREAKS IN THE MID-LEVEL CLOUDS WILL ALLOW EXPANSION.
KSEA...GROWING CONCERNED ABOUT FOG AT THE TERMINAL FROM OVERNIGHT
TONIGHT THROUGH THU MORNING. AREAS OF FOG ARE CURRENTLY OBSERVED
AROUND TIW/TCM. DRYING EASTERLY WINDS AT THE TERMINAL HAVE JUST
ENDED...AND MOST GUIDANCE SHOWS A LIGHT SOUTH BREEZE DEVELOPING
AROUND 08Z-09Z. THIS COULD BRING FOG UP FROM THE SOUTH OVERNIGHT.
IN FACT...THE HRRR MODEL EXPLICITLY SHOWS DENSE FOG OVERSPREADING
KSEA AROUND 08Z-10Z...PERSISTING INTO THE MORNING. THE NEXT TAF
ISSUANCE AT 06Z WILL HIT THE FOG SCENARIO HARDER. FOG WOULD BE
FAIRLY SHALLOW...BUT MID-LEVEL CLOUDS MAY HELP ANY FOG PERSIST UNTIL
20Z OR SO.HANER
&&
.MARINE...A SURFACE LOW ABOUT 350 NM W OF ASTORIA THIS EVENING WILL
WEAKEN AND MOVE SLOWLY SE LATE TONIGHT AND THU...ALLOWING OFFSHORE
FLOW TO WEAKEN. THAT LOW WILL EVENTUALLY DISSIPATE THURSDAY NIGHT
OFF THE S OREGON COAST. OFFSHORE FLOW WILL RE-STRENGTHEN A BIT ON
FRI NGT AND SAT. THIS WILL PROBABLY RESULT IN SCA WINDS AT THE WEST
ENTRANCE. THE MUCH WEAKENED FRONT WILL MOVE OVER THE WA COASTAL AND
OFFSHORE WATERS SATURDAY NIGHT AND SUNDAY.
OFFSHORE FLOW WILL CONTINUE INTO NEXT WEEK. OTHERWISE...OCEAN SWELL
OF 10-13 FEET WILL CONTINUE UNTIL THU EVNG...THEN SUBSIDE BELOW 10
FT.HANER
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST THURSDAY
FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO
60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT
10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE
10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT
GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO
CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT
GRENVILLE TO CAPE SHOALWATER OUT 10 NM.
SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 4 AM PST FRIDAY FOR
GRAYS HARBOR BAR.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
COMPLEX SCENARIO UNFOLDING WITH PRECIPITATION TYPES...ACCUMULATIONS
AND IMPACT. WATCHING THIS MORNING CLOSELY FOR ANY HINT OF IMPACT
FOR AN UPGRADE TO AN ADVISORY FOR FREEZING DRIZZLE...BECAUSE IT
IS OUT THERE OVER IOWA.
WATCHING SNOW MOVE THROUGH THE AREA AND BACK EDGE IS NEARING A
MSP-LSE-RFD LINE AT 09Z. BEHIND IT...REPORTS THROUGH CENTRAL IA
ARE DRIZZLE IS OCCURRING AND DEPENDING ON SURFACE
TEMPERATURES...ICING. WFO DES MOINES HAS HAD DRIZZLE FOR MANY
HOURS WITH ICING TO THE TREES BUT NOT THE GROUND LEVEL SURFACES.
THEY ALSO REPORT VSBY RESTRICTION IN IA MAINLY DUE TO DZ. ELEVATED
ICING SENSOR AT KDSM IS SHOWING SOME ICE ACCUMULATION. THIS
DRIZZLE AREA HAS A WELL FORECAST LEADING EDGE COINCIDENT WITH THE
IR CLOUD TOP WARMING REGION BEHIND THE SNOW ECHOES. KDSM HAS SEEN
-8C TO -10C CLOUD TOP TEMPS ALL NIGHT SUGGESTIVE OF AN ALL LIQUID
SURFACE-BASED SUPERCOOLED LAYER. THIS IS ALL SHIFTING INTO WI
WITH NO AIR MASS CHANGE THROUGH THE MORNING...AND LIGHT VERTICAL
MOTION IN THE 2KM DEEP SATURATED AND SUPERCOOLED LIQUID LAYER.
CALLS TO NERN IA SHERIFFS DO STATE THAT DRIZZLE IS HIT AND MISS
OUT THERE WITH SNOW COVERED ROADS. THE PROBLEM IS THEY ALSO SAID
THAT ICING IS OCCURRING ON ROAD SURFACES. HRRR AND RAP ARE
SUGGESTIVE WE WILL CONTINUE VERTICAL MOTION IN THE
LAYER...POSSIBLY TO -5 UB/S THROUGH THE MORNING...WITH A
DIMINISHING TREND AT LEAST FOR THE NORTH LATER THIS MORNING.
BELIEVE DRIZZLE AND FZDZ WILL BE AROUND THIS MORNING WITH VERY
LIGHT ACCUMULATIONS. WILL NEED TO UPGRADE SPS TO AN ADVISORY FOR
AT LEAST NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THE MORNING.
CANNOT BE SURE THIS DRIZZLE WILL BE ENDING THIS
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN FORECAST AREA AND THUS
LINGERED HIGHER PRECIPITATION CHANCES THERE ALL AFTERNOON...WITH A
SLIGHT BREAK TO THE NORTH.
LATER IN THE AFTERNOON AND TONIGHT WE SEE THE NEXT ROUND OF
PRECIPITATION MOVE IN FROM THE SOUTH ASSOCIATED WITH THE SHORTWAVE
TROUGH OVER TX AT 0930Z. THERE ARE NO REAL SURPRISES IN THIS
FORECAST AND VERY LITTLE CHANGE WAS MADE FROM LATER THURSDAY
THROUGH FRIDAY. A NICE RAIN/SNOW BAND IS EXPECTED AS MOISTURE
TRANSPORT CONVERGENCE ON THE NOSE OF THE LOW-LEVEL FLOW MOVES IN
LATE IN THE DAY WITH PRECIPITABLE WATER VALUES OVER 0.50 INCHES
WHICH IS ABOUT 200 PERCENT NORMAL. THIS FIRST BAND IS FAIRLY
TRANSIENT AND WITH THE OPEN WAVE ALOFT...DEFORMATION BANDING
DOESNT SEEN TO BE AN ISSUE...SO IT IS MULTIPLE SURGES OF WEAK-
MODERATE WARM ADVECTION WITHOUT UPPER LEVEL QVECTOR CONVERGENCE
SUPPORT...BUT IN THE MIDST OF ABUNDANT MOISTURE. SO...A
CLOUDY/RAINY/SNOWY/DRIZZLY PERIOD.
HAVENT MOVED THE RAIN/SNOW LINE MUCH IN THIS FORECAST AND THE 1 TO
3 INCH SNOW ACCUMULATIONS STILL LOOK GOOD AND HIGHLY DEPEND ON
THE LOCATION AND TEMPERATURES. VALLEY LOCATIONS NORTH AND WEST OF
LA CROSSE WILL SEE THE LOWER END OF THOSE VALUES...WHILE COOLER
ELEVATED LOCATIONS AND NORTH-CENTRAL WI NORTH OF HIGHWAY 29...WILL
GET THE HIGHER END. THIS SHOULD NOT BE MUCH OF AN IMPACT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
FRIDAY NIGHT AND SATURDAY...STILL SOME ACTIVE PRECIPITATION
CHANCES FRIDAY NIGHT AS THE ARCTIC FRONT COMES RIPPING IN. ALL
PRECIPITATION WILL CHANGE TO SNOW...AND COLD ADVECTION WILL BE
VERY NOTICEABLE FOR SATURDAY WITH FALLING TEMPERATURES AND WINDS
15 TO 25 MPH.
SUNDAY THROUGH WEDNESDAY...A COLD PERIOD WE HAVENT SEEN THIS
WINTER YET. IT IS STILL LOOKING LIKE WIND CHILL ADVISORIES WILL BE
NEEDED FOR SOME SUNDAY INTO MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY NOON)
ISSUED AT 1135 AM CST THU JAN 7 2016
THIS TAF PERIOD WILL BE DOMINATED BY IFR/LIFR CIGS/VSBYS AS A WARM
AND MOIST AIRMASS IS PUSHED NORTHWARD OVER THE SNOW COVERED
LANDSCAPE. THE LIFR CIGS/VSBYS IN BR/FG WILL BE MORE COMMON OVER THE
HIGHER TERRAIN AREAS /KRST/...WHILE MS/WI RIVER VALLEYS /KLSE/ WILL
BE MORE IFR PERHAPS BRIEF PERIODS OF MVFR. THE NEXT SYSTEM LIFTING
TOWARD AND ACROSS THE AREA WILL SPREAD ANOTHER ROUND OF PRECIP
NORTHEAST ACROSS THE TAF SITES TONIGHT AND MUCH OF FRI. LOWER LEVEL
THEMAL PROFILES IN MODEL SOUNDINGS AND BOUNDARY LAYER TEMPS INDICATE
MOST OF THIS WOULD BE -RA AT KLSE...WITH A -RA/-SN MIX OR -SN AT
KRST. SLUSHY SNOW ACCUMULATIONS TONIGHT INTO FRI MORNING MAY IMPACT
AIRPORT OPS AT KRST...WHILE LITTLE IF ANY SNOWFALL IS EXPECTED AT
KLSE. BOUNDARY LAYER TEMPS TONIGHT/FRI MORNING ARE TRENDING WARM
ENOUGH THAT ANY POTENTIAL ICING THREAT IS QUITE SMALL. CIGS/VSBYS IN
THE BR/FG AND ANY PRECIP SHOULD START TO IMPROVE FRI AFTERNOON AS
THE SYSTEM PASSES AND WINDS SWING AROUND TO THE NORTH AND
NORTHWEST...BRINGING IN A DRYING LOWER LEVEL AIRMASS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1102 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
COMPLEX SCENARIO UNFOLDING WITH PRECIPITATION TYPES...ACCUMULATIONS
AND IMPACT. WATCHING THIS MORNING CLOSELY FOR ANY HINT OF IMPACT
FOR AN UPGRADE TO AN ADVISORY FOR FREEZING DRIZZLE...BECAUSE IT
IS OUT THERE OVER IOWA.
WATCHING SNOW MOVE THROUGH THE AREA AND BACK EDGE IS NEARING A
MSP-LSE-RFD LINE AT 09Z. BEHIND IT...REPORTS THROUGH CENTRAL IA
ARE DRIZZLE IS OCCURRING AND DEPENDING ON SURFACE
TEMPERATURES...ICING. WFO DES MOINES HAS HAD DRIZZLE FOR MANY
HOURS WITH ICING TO THE TREES BUT NOT THE GROUND LEVEL SURFACES.
THEY ALSO REPORT VSBY RESTRICTION IN IA MAINLY DUE TO DZ. ELEVATED
ICING SENSOR AT KDSM IS SHOWING SOME ICE ACCUMULATION. THIS
DRIZZLE AREA HAS A WELL FORECAST LEADING EDGE COINCIDENT WITH THE
IR CLOUD TOP WARMING REGION BEHIND THE SNOW ECHOES. KDSM HAS SEEN
-8C TO -10C CLOUD TOP TEMPS ALL NIGHT SUGGESTIVE OF AN ALL LIQUID
SURFACE-BASED SUPERCOOLED LAYER. THIS IS ALL SHIFTING INTO WI
WITH NO AIR MASS CHANGE THROUGH THE MORNING...AND LIGHT VERTICAL
MOTION IN THE 2KM DEEP SATURATED AND SUPERCOOLED LIQUID LAYER.
CALLS TO NERN IA SHERIFFS DO STATE THAT DRIZZLE IS HIT AND MISS
OUT THERE WITH SNOW COVERED ROADS. THE PROBLEM IS THEY ALSO SAID
THAT ICING IS OCCURRING ON ROAD SURFACES. HRRR AND RAP ARE
SUGGESTIVE WE WILL CONTINUE VERTICAL MOTION IN THE
LAYER...POSSIBLY TO -5 UB/S THROUGH THE MORNING...WITH A
DIMINISHING TREND AT LEAST FOR THE NORTH LATER THIS MORNING.
BELIEVE DRIZZLE AND FZDZ WILL BE AROUND THIS MORNING WITH VERY
LIGHT ACCUMULATIONS. WILL NEED TO UPGRADE SPS TO AN ADVISORY FOR
AT LEAST NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THE MORNING.
CANNOT BE SURE THIS DRIZZLE WILL BE ENDING THIS
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN FORECAST AREA AND THUS
LINGERED HIGHER PRECIPITATION CHANCES THERE ALL AFTERNOON...WITH A
SLIGHT BREAK TO THE NORTH.
LATER IN THE AFTERNOON AND TONIGHT WE SEE THE NEXT ROUND OF
PRECIPITATION MOVE IN FROM THE SOUTH ASSOCIATED WITH THE SHORTWAVE
TROUGH OVER TX AT 0930Z. THERE ARE NO REAL SURPRISES IN THIS
FORECAST AND VERY LITTLE CHANGE WAS MADE FROM LATER THURSDAY
THROUGH FRIDAY. A NICE RAIN/SNOW BAND IS EXPECTED AS MOISTURE
TRANSPORT CONVERGENCE ON THE NOSE OF THE LOW-LEVEL FLOW MOVES IN
LATE IN THE DAY WITH PRECIPITABLE WATER VALUES OVER 0.50 INCHES
WHICH IS ABOUT 200 PERCENT NORMAL. THIS FIRST BAND IS FAIRLY
TRANSIENT AND WITH THE OPEN WAVE ALOFT...DEFORMATION BANDING
DOESNT SEEN TO BE AN ISSUE...SO IT IS MULTIPLE SURGES OF WEAK-
MODERATE WARM ADVECTION WITHOUT UPPER LEVEL QVECTOR CONVERGENCE
SUPPORT...BUT IN THE MIDST OF ABUNDANT MOISTURE. SO...A
CLOUDY/RAINYSNOWY/DRIZZLY PERIOD.
HAVENT MOVED THE RAIN/SNOW LINE MUCH IN THIS FORECAST AND THE 1 TO
3 INCH SNOW ACCUMULATIONS STILL LOOK GOOD AND HIGHLY DEPEND ON
THE LOCATION AND TEMPERATURES. VALLEY LOCATIONS NORTH AND WEST OF
LA CROSSE WILL SEE THE LOWER END OF THOSE VALUES...WHILE COOLER
ELEVATED LOCATIONS AND NORTHCENTRAL WI NORTH OF HIGHWAY 29...WILL
GET THE HIGHER END. THIS SHOULD NOT BE MUCH OF AN IMPACT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
FRIDAY NIGHT AND SATURDAY...STILL SOME ACTIVE PRECIPITATION
CHANCES FRIDAY NIGHT AS THE ARCTIC FRONT COMES RIPPING IN. ALL
PRECIPITATION WILL CHANGE TO SNOW...AND COLD ADVECTION WILL BE
VERY NOTICEABLE FOR SATURDAY WITH FALLING TEMPERATURES AND WINDS
15 TO 25 MPH.
SUNDAY THROUGH WEDNESDAY...A COLD PERIOD WE HAVENT SEEN THIS
WINTER YET. IT IS STILL LOOKING LIKE WIND CHILL ADVISORIES WILL BE
NEEDED FOR SOME SUNDAY INTO MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 510 AM CST THU JAN 7 2016
AS THE FIRST SHORT WAVE TROUGH MOVES AWAY FROM THE REGION...ICE IN
THE CLOUDS IS BEING LOST WHICH IS ALLOWING FOR SOME LIGHT FREEZING
DRIZZLE TO OCCUR. WITH THE FLOW REMAINING SOUTHWEST...SOME
ISENTROPIC UP GLIDE WILL CONTINUE THROUGH THE DAY FROM THE WARM
AIR ADVECTION. THIS WILL CREATE ENOUGH LIFT THROUGH THE SATURATED
LAYER TO KEEP THE FREEZING DRIZZLE GOING UNTIL TEMPERATURES WARM
TO ABOVE 0C AND SWITCH THIS OVER TO DRIZZLE. THE NEXT SHORT WAVE
TROUGH WILL APPROACH THE AREA TONIGHT AND GENERATE SOME BETTER
LIFT THROUGH THE COLUMN. THIS WILL ALSO CREATE A DEEPER SATURATED
LAYER AND ALLOW ICE TO BE REINTRODUCED INTO THE CLOUDS. THIS WILL
CHANGE THE DRIZZLE BACK OVER TO RAIN OR SNOW EARLY THIS
EVENING...BASED ON WHAT THE LOW LEVEL TEMPERATURES ARE. IT
CURRENTLY LOOKS LIKE KRST SHOULD BE COLD ENOUGH FOR MAINLY SNOW
WHILE KLSE WILL BE JUST A TOUCH WARMER FOR RAIN OR A RAIN SNOW
MIX. WITH ALL THIS PRECIPITATION...IFR CEILINGS WILL DOMINATE THE
PERIOD. THE VISIBILITY WILL BE MVFR TO IFR UNTIL THE HEAVIER
PRECIPITATION MOVES IN THIS EVENING WHEN BOTH SITES SHOULD HAVE
IFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
510 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
COMPLEX SCENARIO UNFOLDING WITH PRECIPITATION TYPES...ACCUMULATIONS
AND IMPACT. WATCHING THIS MORNING CLOSELY FOR ANY HINT OF IMPACT
FOR AN UPGRADE TO AN ADVISORY FOR FREEZING DRIZZLE...BECAUSE IT
IS OUT THERE OVER IOWA.
WATCHING SNOW MOVE THROUGH THE AREA AND BACK EDGE IS NEARING A
MSP-LSE-RFD LINE AT 09Z. BEHIND IT...REPORTS THROUGH CENTRAL IA
ARE DRIZZLE IS OCCURRING AND DEPENDING ON SURFACE
TEMPERATURES...ICING. WFO DES MOINES HAS HAD DRIZZLE FOR MANY
HOURS WITH ICING TO THE TREES BUT NOT THE GROUND LEVEL SURFACES.
THEY ALSO REPORT VSBY RESTRICTION IN IA MAINLY DUE TO DZ. ELEVATED
ICING SENSOR AT KDSM IS SHOWING SOME ICE ACCUMULATION. THIS
DRIZZLE AREA HAS A WELL FORECAST LEADING EDGE COINCIDENT WITH THE
IR CLOUD TOP WARMING REGION BEHIND THE SNOW ECHOES. KDSM HAS SEEN
-8C TO -10C CLOUD TOP TEMPS ALL NIGHT SUGGESTIVE OF AN ALL LIQUID
SURFACE-BASED SUPERCOOLED LAYER. THIS IS ALL SHIFTING INTO WI
WITH NO AIR MASS CHANGE THROUGH THE MORNING...AND LIGHT VERTICAL
MOTION IN THE 2KM DEEP SATURATED AND SUPERCOOLED LIQUID LAYER.
CALLS TO NERN IA SHERIFFS DO STATE THAT DRIZZLE IS HIT AND MISS
OUT THERE WITH SNOW COVERED ROADS. THE PROBLEM IS THEY ALSO SAID
THAT ICING IS OCCURRING ON ROAD SURFACES. HRRR AND RAP ARE
SUGGESTIVE WE WILL CONTINUE VERTICAL MOTION IN THE
LAYER...POSSIBLY TO -5 UB/S THROUGH THE MORNING...WITH A
DIMINISHING TREND AT LEAST FOR THE NORTH LATER THIS MORNING.
BELIEVE DRIZZLE AND FZDZ WILL BE AROUND THIS MORNING WITH VERY
LIGHT ACCUMULATIONS. WILL NEED TO UPGRADE SPS TO AN ADVISORY FOR
AT LEAST NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THE MORNING.
CANNOT BE SURE THIS DRIZZLE WILL BE ENDING THIS
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN FORECAST AREA AND THUS
LINGERED HIGHER PRECIPITATION CHANCES THERE ALL AFTERNOON...WITH A
SLIGHT BREAK TO THE NORTH.
LATER IN THE AFTERNOON AND TONIGHT WE SEE THE NEXT ROUND OF
PRECIPITATION MOVE IN FROM THE SOUTH ASSOCIATED WITH THE SHORTWAVE
TROUGH OVER TX AT 0930Z. THERE ARE NO REAL SURPRISES IN THIS
FORECAST AND VERY LITTLE CHANGE WAS MADE FROM LATER THURSDAY
THROUGH FRIDAY. A NICE RAIN/SNOW BAND IS EXPECTED AS MOISTURE
TRANSPORT CONVERGENCE ON THE NOSE OF THE LOW-LEVEL FLOW MOVES IN
LATE IN THE DAY WITH PRECIPITABLE WATER VALUES OVER 0.50 INCHES
WHICH IS ABOUT 200 PERCENT NORMAL. THIS FIRST BAND IS FAIRLY
TRANSIENT AND WITH THE OPEN WAVE ALOFT...DEFORMATION BANDING
DOESNT SEEN TO BE AN ISSUE...SO IT IS MULTIPLE SURGES OF WEAK-
MODERATE WARM ADVECTION WITHOUT UPPER LEVEL QVECTOR CONVERGENCE
SUPPORT...BUT IN THE MIDST OF ABUNDANT MOISTURE. SO...A
CLOUDY/RAINYSNOWY/DRIZZLY PERIOD.
HAVENT MOVED THE RAIN/SNOW LINE MUCH IN THIS FORECAST AND THE 1 TO
3 INCH SNOW ACCUMULATIONS STILL LOOK GOOD AND HIGHLY DEPEND ON
THE LOCATION AND TEMPERATURES. VALLEY LOCATIONS NORTH AND WEST OF
LA CROSSE WILL SEE THE LOWER END OF THOSE VALUES...WHILE COOLER
ELEVATED LOCATIONS AND NORTHCENTRAL WI NORTH OF HIGHWAY 29...WILL
GET THE HIGHER END. THIS SHOULD NOT BE MUCH OF AN IMPACT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
FRIDAY NIGHT AND SATURDAY...STILL SOME ACTIVE PRECIPITATION
CHANCES FRIDAY NIGHT AS THE ARCTIC FRONT COMES RIPPING IN. ALL
PRECIPITATION WILL CHANGE TO SNOW...AND COLD ADVECTION WILL BE
VERY NOTICEABLE FOR SATURDAY WITH FALLING TEMPERATURES AND WINDS
15 TO 25 MPH.
SUNDAY THROUGH WEDNESDAY...A COLD PERIOD WE HAVENT SEEN THIS
WINTER YET. IT IS STILL LOOKING LIKE WIND CHILL ADVISORIES WILL BE
NEEDED FOR SOME SUNDAY INTO MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 510 AM CST THU JAN 7 2016
AS THE FIRST SHORT WAVE TROUGH MOVES AWAY FROM THE REGION...ICE IN
THE CLOUDS IS BEING LOST WHICH IS ALLOWING FOR SOME LIGHT FREEZING
DRIZZLE TO OCCUR. WITH THE FLOW REMAINING SOUTHWEST...SOME
ISENTROPIC UP GLIDE WILL CONTINUE THROUGH THE DAY FROM THE WARM
AIR ADVECTION. THIS WILL CREATE ENOUGH LIFT THROUGH THE SATURATED
LAYER TO KEEP THE FREEZING DRIZZLE GOING UNTIL TEMPERATURES WARM
TO ABOVE 0C AND SWITCH THIS OVER TO DRIZZLE. THE NEXT SHORT WAVE
TROUGH WILL APPROACH THE AREA TONIGHT AND GENERATE SOME BETTER
LIFT THROUGH THE COLUMN. THIS WILL ALSO CREATE A DEEPER SATURATED
LAYER AND ALLOW ICE TO BE REINTRODUCED INTO THE CLOUDS. THIS WILL
CHANGE THE DRIZZLE BACK OVER TO RAIN OR SNOW EARLY THIS
EVENING...BASED ON WHAT THE LOW LEVEL TEMPERATURES ARE. IT
CURRENTLY LOOKS LIKE KRST SHOULD BE COLD ENOUGH FOR MAINLY SNOW
WHILE KLSE WILL BE JUST A TOUCH WARMER FOR RAIN OR A RAIN SNOW
MIX. WITH ALL THIS PRECIPITATION...IFR CEILINGS WILL DOMINATE THE
PERIOD. THE VISIBILITY WILL BE MVFR TO IFR UNTIL THE HEAVIER
PRECIPITATION MOVES IN THIS EVENING WHEN BOTH SITES SHOULD HAVE
IFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FREEZING RAIN ADVISORY UNTIL NOON CST TODAY FOR WIZ054-055-061.
MN...NONE.
IA...FREEZING RAIN ADVISORY UNTIL NOON CST TODAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
408 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
COMPLEX SCENARIO UNFOLDING WITH PRECIPITATION TYPES...ACCUMULATIONS
AND IMPACT. WATCHING THIS MORNING CLOSELY FOR ANY HINT OF IMPACT
FOR AN UPGRADE TO AN ADVISORY FOR FREEZING DRIZZLE...BECAUSE IT
IS OUT THERE OVER IOWA.
WATCHING SNOW MOVE THROUGH THE AREA AND BACK EDGE IS NEARING A
MSP-LSE-RFD LINE AT 09Z. BEHIND IT...REPORTS THROUGH CENTRAL IA
ARE DRIZZLE IS OCCURRING AND DEPENDING ON SURFACE
TEMPERATURES...ICING. WFO DES MOINES HAS HAD DRIZZLE FOR MANY
HOURS WITH ICING TO THE TREES BUT NOT THE GROUND LEVEL SURFACES.
THEY ALSO REPORT VSBY RESTRICTION IN IA MAINLY DUE TO DZ. ELEVATED
ICING SENSOR AT KDSM IS SHOWING SOME ICE ACCUMULATION. THIS
DRIZZLE AREA HAS A WELL FORECAST LEADING EDGE COINCIDENT WITH THE
IR CLOUD TOP WARMING REGION BEHIND THE SNOW ECHOES. KDSM HAS SEEN
-8C TO -10C CLOUD TOP TEMPS ALL NIGHT SUGGESTIVE OF AN ALL LIQUID
SURFACE-BASED SUPERCOOLED LAYER. THIS IS ALL SHIFTING INTO WI
WITH NO AIR MASS CHANGE THROUGH THE MORNING...AND LIGHT VERTICAL
MOTION IN THE 2KM DEEP SATURATED AND SUPERCOOLED LIQUID LAYER.
CALLS TO NERN IA SHERIFFS DO STATE THAT DRIZZLE IS HIT AND MISS
OUT THERE WITH SNOW COVERED ROADS. THE PROBLEM IS THEY ALSO SAID
THAT ICING IS OCCURRING ON ROAD SURFACES. HRRR AND RAP ARE
SUGGESTIVE WE WILL CONTINUE VERTICAL MOTION IN THE
LAYER...POSSIBLY TO -5 UB/S THROUGH THE MORNING...WITH A
DIMINISHING TREND AT LEAST FOR THE NORTH LATER THIS MORNING.
BELIEVE DRIZZLE AND FZDZ WILL BE AROUND THIS MORNING WITH VERY
LIGHT ACCUMULATIONS. WILL NEED TO UPGRADE SPS TO AN ADVISORY FOR
AT LEAST NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THE MORNING.
CANNOT BE SURE THIS DRIZZLE WILL BE ENDING THIS
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN FORECAST AREA AND THUS
LINGERED HIGHER PRECIPITATION CHANCES THERE ALL AFTERNOON...WITH A
SLIGHT BREAK TO THE NORTH.
LATER IN THE AFTERNOON AND TONIGHT WE SEE THE NEXT ROUND OF
PRECIPITATION MOVE IN FROM THE SOUTH ASSOCIATED WITH THE SHORTWAVE
TROUGH OVER TX AT 0930Z. THERE ARE NO REAL SURPRISES IN THIS
FORECAST AND VERY LITTLE CHANGE WAS MADE FROM LATER THURSDAY
THROUGH FRIDAY. A NICE RAIN/SNOW BAND IS EXPECTED AS MOISTURE
TRANSPORT CONVERGENCE ON THE NOSE OF THE LOW-LEVEL FLOW MOVES IN
LATE IN THE DAY WITH PRECIPITABLE WATER VALUES OVER 0.50 INCHES
WHICH IS ABOUT 200 PERCENT NORMAL. THIS FIRST BAND IS FAIRLY
TRANSIENT AND WITH THE OPEN WAVE ALOFT...DEFORMATION BANDING
DOESNT SEEN TO BE AN ISSUE...SO IT IS MULTIPLE SURGES OF WEAK-
MODERATE WARM ADVECTION WITHOUT UPPER LEVEL QVECTOR CONVERGENCE
SUPPORT...BUT IN THE MIDST OF ABUNDANT MOISTURE. SO...A
CLOUDY/RAINYSNOWY/DRIZZLY PERIOD.
HAVENT MOVED THE RAIN/SNOW LINE MUCH IN THIS FORECAST AND THE 1 TO
3 INCH SNOW ACCUMULATIONS STILL LOOK GOOD AND HIGHLY DEPEND ON
THE LOCATION AND TEMPERATURES. VALLEY LOCATIONS NORTH AND WEST OF
LA CROSSE WILL SEE THE LOWER END OF THOSE VALUES...WHILE COOLER
ELEVATED LOCATIONS AND NORTHCENTRAL WI NORTH OF HIGHWAY 29...WILL
GET THE HIGHER END. THIS SHOULD NOT BE MUCH OF AN IMPACT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
FRIDAY NIGHT AND SATURDAY...STILL SOME ACTIVE PRECIPITATION
CHANCES FRIDAY NIGHT AS THE ARCTIC FRONT COMES RIPPING IN. ALL
PRECIPITATION WILL CHANGE TO SNOW...AND COLD ADVECTION WILL BE
VERY NOTICEABLE FOR SATURDAY WITH FALLING TEMPERATURES AND WINDS
15 TO 25 MPH.
SUNDAY THROUGH WEDNESDAY...A COLD PERIOD WE HAVENT SEEN THIS
WINTER YET. IT IS STILL LOOKING LIKE WIND CHILL ADVISORIES WILL BE
NEEDED FOR SOME SUNDAY INTO MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CST WED JAN 6 2016
LIGHT SNOW WILL SWITCH OVER TO LIGHT FREEZING DRIZZLE OVERNIGHT
INTO EARLY THURSDAY MORNING. IFR TO LIFR CONDITIONS ARE EXPECTED.
THE FREEZING DRIZZLE LOOKS TO SWITCH OVER TO LIQUID DRIZZLE
THURSDAY MORNING AS TEMPERATURES WARM ABOVE FREEZING. KRST COULD
DROP TO VLIFR AT TIMES THURSDAY MORNING IN FOG. ANOTHER STORM
SYSTEM THEN MOVES IN THURSDAY AFTERNOON INTO THURSDAY EVENING WITH
A RAIN SNOW MIX EXPECTED...SWITCHING OVER TO MAINLY SNOW LATE
THURSDAY NIGHT. IFR TO LIFR CONDITIONS ARE EXPECTED IN THE SNOW
THURSDAY NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FREEZING RAIN ADVISORY UNTIL NOON CST TODAY FOR WIZ054-055-061.
MN...NONE.
IA...FREEZING RAIN ADVISORY UNTIL NOON CST TODAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CST WED JAN 6 2016
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 301 PM CST WED JAN 6 2016
MESSY WINTER WEATHER TO IMPACT THE AREA THROUGH THE PERIOD.
WATER VAPOR IMAGERY SHOWING A VIGOROUS MID-LEVEL TROUGH/CLOSED LOW
OVER WESTERN IA. RADAR MOSAIC SHOWING PRECIPITATION EXPANDING AHEAD
OF THIS WAVE FROM SOUTHERN MN INTO IA AND SOUTHERN WI. GROUND
OBSERVATIONS SHOWING MAINLY A MIXTURE OF DRIZZLE/SNOW ACROSS THAT
AREA.
WILL BE WATCHING THAT MID-LEVEL LOW LIFT NORTHEAST INTO/THROUGH THE
AREA TONIGHT WHILE WEAKENING/DAMPENING OUT. RAP SHOWS THAT THE P-
TYPE SHOULD BE MAINLY IN THE FORM OF LIGHT SNOW WITH INCREASING
COLUMN SATURATION WITH ICE PRESENT IN CLOUD. HOWEVER...THINGS
COULD GET TRICKY FROM AROUND MIDNIGHT THROUGH THE OVERNIGHT HOURS
AS THE WAVE LIFTS NORTHEAST OF THE AREA WITH LOSS OF ICE IN CLOUD
AND SOME LINGERING LIFT THROUGH THIS CLOUD. IF THERE IS INDEED
TOTAL ICE LOSS...COULD BE A BOUT OF FREEZING DRIZZLE. THIS LOOKS
MOST LIKELY FOR AREAS ALONG AND WEST OF THE MISSISSIPPI RIVER.
OTHERWISE...COULD SEE UP TO AN INCH OF SNOWFALL OVERNIGHT. WILL
ALSO SEE SOME FOG MAINLY ALONG/SOUTH OF I-90 WITH
WARMING/INCREASING MOISTURE THROUGH TONIGHT. THIS FOR THE MOST
PART LOOKS LIKE A SUB-HEADLINE EVENT...BUT WILL KEEP A CLOSE EYE
ON THE WEATHER AS IT EVOLVES.
FOR THURSDAY...MODELS SHOW MID-LEVEL RIDGING BUILDING BEHIND THE
DEPARTING WAVE THURSDAY MORNING...BUT WILL HAVE PLENTY OF LINGERING
MOISTURE/STRATUS FOR SOME PATCHY DRIZZLE AS WEAK LIFT CONTINUES
THROUGH THE SUPER-COOLED/ICE-LESS CLOUD LAYER. COULD SEE SOME PATCHY
FREEZING DRIZZLE AS WELL FOR AREAS THAT REMAIN BELOW 32 IN THE
MORNING. HOWEVER...ROADS SHOULD BE TREATED ENOUGH FOR MINIMAL TRAVEL
IMPACT. MOISTURE/PRECIPITATION CHANCES RAMP UP IN THE AFTERNOON
AHEAD OF A STRONGER WAVE MOVING OUT OF THE SOUTHERN PLAINS. WITH
HIGH TEMPERATURES PUSHING WELL INTO THE 30S...LOOKS LIKE A RAIN/SNOW
MIX SETTING UP. AS SUCH...NOT EXPECTING ANY APPRECIABLE SNOW
ACCUMULATIONS...PERHAPS A DUSTING/TENTH OF AN INCH IN SOME HIGHER
TERRAIN AREAS. IN ADDITION...LOOKS LIKE FOG WILL BE INCREASING AS
WELL AS THIS WARMING/MOIST AIR RIDES OVER THE EXISTING COLD SNOW
PACK. WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR DENSE FOG.
FOR THURSDAY NIGHT...MOISTURE WILL CONTINUE TO SPILL INTO THE AREA
AHEAD OF LOW PRESSURE MOVING INTO NORTHERN MO BY EARLY FRIDAY
MORNING. MODEL SOUNDING TEMPERATURE PROFILES SUPPORT A RAIN/SNOW MIX
ACROSS THE AREA WITH HIGHER TERRAIN FAVORING MORE SNOW THAN RAIN.
COULD SEE 1-2 INCHES ACROSS HIGHER TERRAIN AREAS MAINLY FROM
SOUTHEAST MN INTO NORTH CENTRAL WI.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 301 PM CST WED JAN 6 2016
FRIDAY WILL SEE THE LOW MOVE THROUGH EASTERN WI. LATEST
MODELS/THINKING IS THAT MAINLY RAIN WILL BE SEEN ACROSS MOST OF THE
AREA THROUGH THE DAY WITH RAIN/SNOW MIX FROM NORTHEAST IA/SOUTHEAST
MN INTO NORTH CENTRAL WI AS COLDER AIR FILTERS IN ON THE BACKSIDE OF
THE LOW. COULD SEE UP TO AN INCH OF ADDITIONAL SNOWFALL ACROSS THAT
AREA. OTHERWISE...LOOK FOR HIGH TEMPERATURES ACROSS THE AREA IN THE
MID TO UPPER 30S.
COLDER AIR FILTERS INTO THE AREA FRIDAY NIGHT INTO SATURDAY ALONG
WITH A CHANCE FOR LIGHT SNOW. LOOK FOR LOWS FRIDAY NIGHT MAINLY IN
THE 20S WITH HIGHS ON SATURDAY NOT BUDGING MUCH FROM THE OVERNIGHT
LOWS.
SMALL CHANCE OF SNOW LINGERS INTO SATURDAY NIGHT AS COLDER ARCTIC
AIR SPILLS INTO THE REGION. BY EARLY SUNDAY MORNING...WE WILL BE
LOOKING AT TEMPERATURE ONLY IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO ALONG WITH A FAIRLY STILL WIND IN THE 10 TO 20 MPH RANGE WITH A
FEW GUSTS AROU7ND 25 MPH. THIS WILL PRODUCE WIND CHILLS SUNDAY
MORNING IN THE MINUS 15 TO MINUS 25 DEGREE RANGE ACROSS SOUTHEAST
MN/NORTHEAST IA. WILL HAVE TO KEEP AN EYE ON THIS FOR POTENTIAL
WINDCHILL HEADLINES ACROSS THAT AREA.
MAIN STORY FOR SUNDAY THROUGH WEDNESDAY WILL BE ARCTIC AIRMASS
PAYING US A VISIT. HIGHS START OFF IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO SUNDAY...MODERATING SOME INTO THE SINGLE DIGITS/TEENS
ABOVE ZERO MONDAY THROUGH WEDNESDAY. OVERNIGHT LOWS LOOK TO BE IN
THE SINGLE DIGITS ABOVE/BELOW ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CST WED JAN 6 2016
LIGHT SNOW WILL SWITCH OVER TO LIGHT FREEZING DRIZZLE OVERNIGHT
INTO EARLY THURSDAY MORNING. IFR TO LIFR CONDITIONS ARE EXPECTED.
THE FREEZING DRIZZLE LOOKS TO SWITCH OVER TO LIQUID DRIZZLE
THURSDAY MORNING AS TEMPERATURES WARM ABOVE FREEZING. KRST COULD
DROP TO VLIFR AT TIMES THURSDAY MORNING IN FOG. ANOTHER STORM
SYSTEM THEN MOVES IN THURSDAY AFTERNOON INTO THURSDAY EVENING WITH
A RAIN SNOW MIX EXPECTED...SWITCHING OVER TO MAINLY SNOW LATE
THURSDAY NIGHT. IFR TO LIFR CONDITIONS ARE EXPECTED IN THE SNOW
THURSDAY NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
408 AM EST SAT JAN 9 2016
.SYNOPSIS...
HIGH PRESSURE FROM EASTERN CANADA DOWN TO THE MID ATLANTIC STATES
WEAKENS LATE TODAY. LOW PRESSURE IN THE OHIO VALLEY THIS EVENING
INTENSIFIES RAPIDLY IS IT CROSSES PENNSYLVANIA AND NEW YORK STATE
SUNDAY. IT DRAWS A STRONG WARM FRONT NORTHWARD THROUGH OUR AREA
SUNDAY MORNING, THEN A STRONG COLD FRONT PASSES OFF THE COAST
SUNDAY AFTERNOON. HIGH PRESSURE BUILDS TO OUR SOUTH LATE MONDAY.
GREAT LAKES LOW PRESSURE TUESDAY SENDS A STRONG COLD FRONT ACROSS
THE MID ATLANTIC STATES TUESDAY EVENING. THAT LOW REFORMS ALONG
COASTAL NEW ENGLAND AND INTENSIFIES RAPIDLY ON WEDNESDAY. HIGH
PRESSURE BUILDS TO OUR SOUTH ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CANCELED THE WINTER WEATHER ADVISORY FOR ALL BUT MONROE, PA AND
SUSSEX, NJ WITH THIS FORECAST PACKAGE. SHORT RANGE MESOSCALE
MODELS CONTINUE TO SHOW LITTLE TO NO QPF EXPECTED IN THE NEXT FEW
HOURS. ALSO TEMPERATURES ARE ABOVE FREEZING ALMOST EVERYWHERE IN
THE PREVIOUS ADVISORY WITH THE EXCEPTION OF MONROE AND SUSSEX
COUNTIES. THIS IS WHERE SOME PATCHES OF THE COUNTY THE TEMPERATURE
IS NEAR FREEZING AND SOME VERY LIGHT FREEZING RAIN MAY OCCUR IF
QPF OCCURS IN THE NEXT FEW HOURS.
OTHERWISE, TODAY LOOKS TO BE A CLOUDY DAY ACROSS THE REGION AS A
WARM FRONTAL BOUNDARY LIFTS NORTHWARD INTO NEW ENGLAND AND LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST UNTIED STATES COASTLINE. THIS
WILL RESULT IN WARMER AND MOISTER BEING ADVECTED INTO THE REGION
WITH EASTERLY WINDS FROM 5-10 MPH. DAYTIME TEMPERATURES SHOULD RISE
TO AROUND 50 FOR MOST LOCATIONS WITH THE POCONOS STRUGGLING TO GET
OUT OF THE UPPER 30`S. BOTH THE HRRR AND RAP MESOSCALE MODELS ARE
TRYING TO SPIT OUT A BRIEF SHOWER OR TWO TODAY, SO HAVE LOW OR
SLIGHT CHANCE POPS ACROSS THE REGION TODAY. THE MAJORITY OF THE
REGION WILL STAY DRY THROUGH THE DAY
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE LOW PRESSURE IN THE SOUTHEAST UNITED STATES WILL CONTINUE TO
MOVE QUICKLY NORTHWARD TONIGHT REACHING OUR AREA BY SUNDAY MORNING
WITH A WARM FRONT EXTENDING EAST OF THE LOW PRESSURE CENTER. AN
AGGRESSIVE LLJ MODELED NEAR 60 KNOTS WILL CONTINUE TO SEND NORTHWARD
WARMER AND MOIST AIR INTO THE REGION. MOISTURE LIFTING OVER THE WARM
FRONT WILL LEAD TO WIDESPREAD RAIN BREAKING OUT TO OUR SOUTH LATE
SATURDAY. THE RAIN WILL INCREASE IN COVERAGE AND INTENSITY AS THE
NIGHT GOES ON WITH ALL LOCATIONS SEEING A STEADY RAIN BY SUNDAY
MORNING. TEMPERATURES WILL ACTUALLY RISE OVERNIGHT AND THE FORECAST
DOES GO WARMER WITH THE TEMPERATURES OVERNIGHT THAN WHAT THE MAV/MET
GUIDANCE SUGGESTS DUE TO THE LLJ INFLUENCE. AROUND HALF AN INCH OF
RAIN SHOULD FALL TONIGHT WITH ADDITIONAL RAIN ON SUNDAY. SOME OF THE
HEAVIER INTERVALS OF RAIN MAY CAUSE SOME PONDING OF WATER ON
ROADWAYS.
WINDS WILL INCREASE AS WELL, THE GFS, ECMWF AND NAM ALL
SUGGEST WINDS AT 925 MB REACH AT LEAST 50 MPH BY SUNDAY MORNING SE
OF PHILADELPHIA. WHILE THE STRONGEST WINDS WILL LIKELY BE ON SUNDAY,
THE FORECAST DOES GO STRONGER THAN GUIDANCE WITH THE WINDS AFTER
MIDNIGHT TONIGHT. SOME EAST TO SOUTHEAST WIND GUSTS AROUND 25 MPH
ARE POSSIBLE BY SUNDAY MORNING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
500 MB: A NEGATIVE TILT SHORT WAVE RIPS NEWD THROUGH THE NORTHEAST
SUNDAY FOLLOWED BY THE DEVELOPMENT OF A FULL LATITUDE TROUGH ALONG
THE EAST COAST NEXT TUESDAY AND THEN WESTERLY FLOW NEXT THURSDAY
BEFORE A NEW TROUGH FORMS IN THE CENTRAL USA BY NEXT WEEKEND.
TEMPERATURES: AFTER RECORD OR NEAR RECORD WARMTH SUNDAY AND MAXIMUM
TEMPERATURES NEARLY 25 DEGREES ABOVE NORMAL, CALENDAR DAY AVERAGES
WILL COOL TO NEAR NORMAL MONDAY AND TUESDAY, THEN SLIP A FEW DEGREES
BELOW NORMAL WEDNESDAY. THEREAFTER THERE IS SOME UNCERTAINTY...
BUT OVERALL NEAR OR SLIGHTLY BELOW NORMAL THURSDAY AND FRIDAY.
FORECAST BASIS: UNLESS OTHERWISE NOTED, A 50 50 BLEND 00Z/9 GFS/NAM
MOS GUIDANCE SUNDAY-SUNDAY NIGHT, THEREAFTER THE 00Z/9 GFS MEX MOS
MONDAY AND TUESDAY, THEN FOR TUESDAY NIGHT-FRIDAY GENERALLY THE
06Z/9 SUPERBLEND WHICH INCLUDES 00Z/9 GFS MEX GUIDANCE AND WPC
GUIDANCE.
THE DAILIES...
SUNDAY...A STORMY MORNING WITH AN OPPORTUNITY FOR A STRONG TSTM
IN STRONG SE INFLOW WITH INSTABILITY, ESPECIALLY ALOFT WHERE SWI
WILL BE BRIEFLY NEAR -2C, TT IN THE LOWER 50S AND RAPIDLY FALLING
SFC PRES. THIS COULD MEAN ISOLATED WIND GUSTS 40-50 MPH, ESPECIALLY
DELMARVA AND COASTAL NJ.
WE MAY EVENTUALLY NEED A WIND ADVY FOR THE NEAREST 5 MILES OF THE NJ
COAST IN THE 10Z-15Z TIME FRAME AND THIS IS WHERE I`VE GREATEST
CONFIDENCE ON VERIFYING NON CONVECTIVE 46 MPH SE WIND GUSTS.
BRIEF POOR DRAINAGE STREET FLOODING IN THE MORNING BUT OTRW NO
STREAM FLOODING EXPECTED.
TIDES WILL APPROACH MINOR ADVISORY STAGE IN THE 12Z-14Z TIME FRAME
BUT NO ADVISORY ATTM.
A WSHIFT TO WSW IN THE AFTERNOON WITH RECORD OR NEAR RECORD
WARMTH DURING MIDDAY BEGINNING TO BE SWEPT SEAWARD AND MAYBE ONE
LAST BAND OF SHOWERS?.
SUNDAY NIGHT...P/C, WINDY AND TURNING COLDER. GUSTY WEST WINDS 30-40
MPH. STRONG PRESSURE RISES DURING THE EVENING ACCOMPANIES THE INFLUX
OF COLDER DRIER AIR. SMALL CHC OF FLURRIES IN THE POCONOS.
MONDAY...DRY.
TUESDAY...CHANCE OF SNOW SHOWERS OR FLURRIES IN THE DESTABILIZING
AIRMASS AS A STRONG TROUGH DEVELOPS ALONG THE EAST COAST. GUSTY
SOUTHWEST WINDS 20 TO 25 MPH SHIFTING TO WEST AT NIGHT WITH GUSTS
20 TO 30 MPH.
WEDNESDAY...WINDY AND COLD. DRY WITH EXCEPTION ALONG AND NORTH OF
I-78 WHERE MODEL INDICATIONS OF STEEP LAPSE RATES AND POSSIBLE
FLURRIES. WESTERLY WINDS WILL BE GUSTING 30 TO POSSIBLY 40 MPH.
THURSDAY...DIMINISHING WIND AND NOT QUITE AS COLD.
FRIDAY...UNCERTAINTY. FOR NOW, FORECASTING QUIET WEATHER (NOT THE
00Z/9 ECMWF OPERATIONAL SOLUTION)
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
MOST LOCATIONS ARE CURRENTLY VARYING BETWEEN MVFR AND VFR CEILINGS.
THIS WILL LIKELY CONTINUE TILL ABOUT 11Z. LOCATIONS FROM KPHL TO
THE SOUTH AND EAST HAVE THE BEST CHANCE TO STAY VFR THE LONGEST. THE
GENERAL EXPECTATION WILL BE FOR CEILINGS TO LOWER TO IFR AROUND 12Z
THIS MORNING. IFR CEILINGS ARE THEN EXPECTED TO BE PREDOMINANT
THROUGH SATURDAY. HOWEVER, CONFIDENCE IS LOW AT THIS POINT THROUGH
23Z SATURDAY ON CEILINGS, SINCE THE CEILINGS HAVE BEEN HIGHER THAN
SUGGESTED FROM SOME OUR FORECASTING TOOLS. VISIBILITIES WILL RANGE
FROM MVFR TO VFR ACROSS THE REGION.
MUCH HIGHER CONFIDENCE TONIGHT FOR IFR CEILINGS WITH LOWERING
VISIBILITIES AND RAIN DEVELOPING BY 06Z SUNDAY FROM SOUTH TO
NORTH.
OUTLOOK...
SUNDAY MORNING...EARLY IFR CONDITIONS IN SHOWERY BRIEFLY HEAVY
RAINS, POSSIBLE ISOLATED TSTM. SE WINDS GUSTY 20-25 KT EXCEPT
POSSIBLY 40-45 KT IN A TSTM. LLWS VCNTY KMIV AND KACY.
SUNDAY AFTERNOON...BECOMING VFR CIGS AOA 3500 FT WITH A POSSIBLE
RESIDUAL BAND OF SHOWERS ACCOMPANY THE COLD FRONT. WINDS SHIFTING
SOUTHWEST THEN WEST AND GUSTY 25-35 KT.
SUNDAY NIGHT-MONDAY...MOSTLY VFR. GUSTY WEST-NORTHWEST WINDS
25-30 KT.
MONDAY NIGHT...VFR.
TUESDAY-WEDNESDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS BETWEEN 20
AND 25 KT TUESDAY, BECOMING WEST-NORTHWEST TUESDAY NIGHT INTO
WEDNESDAY. GUSTS INCREASING TO 30 TO 35 KT WEDNESDAY.
&&
.MARINE...
CURRENTLY WAVE HEIGHTS ARE SIX TO SEVEN FEET ON THE OCEAN WATERS
AND WILL CONTINUE TO BUILD SLOWLY THROUGH THE DAY TODAY AND INTO
TONIGHT. WINDS WILL REMAIN OUT OF THE EAST UNDER SCA CRITERIA
TODAY BUT WILL RAMP UP AFTER MIDNIGHT TONIGHT, REACHING 30 KNOTS
TOWARD SUNRISE SUNDAY. STRONGER WINDS A FEW THOUSAND FEET UP IN
THE ATMOSPHERE MAY MIX DOWN LEADING TO EVEN LOCALLY HIGHER WIND
GUSTS TOWARD SUNRISE SUNDAY.
ATLC COAST: SINCE ADVISORY SEAS ARE IN PROGRESS, WE CONTINUED THE
SCA HEADLINE INTO TONIGHT BUT THE SCA WILL PROBABLY BE DISCONTINUED
AT 330 PM FOR ONE PRIMARY HEADLINE AS GALE WARNING WINDS DRAW
CLOSER TO TIME ZERO.
DE BAY: SCA CANCELLED SINCE THE PREDOMINANT INTERMITTENT GALE ON
SUNDAY SUPERSEDES THE BRIEF TRANSITION FROM NON ADVISORY TO GALE
WARNING EARLY SUNDAY.
OUTLOOK...
SEA SURFACE TEMPERATURES REMAIN VERY WARM FOR JANUARY...NEAR 50F
WHICH IS ABOUT 8 DEGREES ABOVE NORMAL. THIS CONTRIBUTES TO GREATER
INSTABILITY IN WESTERLY TO NORTHERLY FLOW COLD AIR PATTERNS AND
POSSIBLY STRONGER THAN MODELED WINDS. THIS COULD WELL AGAIN BE A
FACTOR IN STRONG COLD AIR ADVECTION WIND TRANSFER SUNDAY NIGHT.
SUNDAY-SUNDAY NIGHT...GALE WARNING ISSUED, FIRST FOR 1-3 HOURS SE
INFLOW GUSTS NEAR 35KT DURING THE MORNING. WE MAY NEED A SPECIAL
MARINE WARNING FOR ISOLATED TSTM GUSTS 40-45 KT. THEN A 9 TO 12
HOUR PERIOD OF WESTERLY GALES IS ANTICIPATED FOR LATE SUNDAY OR
MORE LIKELY SUNDAY NIGHT.
MONDAY-TUESDAY...OTHER THAN A BRIEF BREAK LATE MONDAY NIGHT INTO
EARLY TUESDAY, WINDS AND SEAS LIKELY TO REMAIN ABOVE SMALL CRAFT
CRITERIA THOUGH TUESDAY.
WEDNESDAY...THERE IS A HIGH PROBABILITY FOR GALE FORCE NORTHWEST
WIND GUSTS OF 35-40 KT.
&&
.TIDES/COASTAL FLOODING...
WITH THE NEW MOON ON SATURDAY AND AN INCREASING FLOW EASTERLY
FLOW, TIDES COULD APPROACH THE MINOR COASTAL FLOOD LEVEL SUNDAY.
CURRENTLY THE TIDE WITH THE HIGHEST FORECAST IS SUNDAY MORNING.
FOR NOW ITS A MARGINAL CHANCE OF MINOR COASTAL FLOODING AND NO
ADVISORY IS BEING ISSUED ATTM.
ALSO, BEHIND THE STORM SYSTEM, STRONG NORTHWEST WINDS WILL DEVELOP.
CURRENT ETSS FORECASTS IN INDICATING THE POSSIBILITY OF APPROACHING
BLOW OUT FOR SOME AREAS, ESPECIALLY THE DELAWARE BAY AND POSSIBLY
THE TIDAL DELAWARE RIVER.
&&
.CLIMATE...
RECORD HIGHS LIKELY SUNDAY AT SEVERAL LOCATIONS.
DAILY RECORD HIGHS FOR SUNDAY JAN 10 ARE LISTED BELOW:
LOCATION RECORD YEAR
------------------------------
ATLANTIC CITY 63 1930
PHILADELPHIA 63 1950
WILMINGTON 64 1930
ALLENTOWN 60 1924
TRENTON 62 1950
GEORGETOWN 67 1950
READING 58 1939
MOUNT POCONO 57 1998
WE`LL BRING THE SNOW CLIMATOLOGY BACK EARLY NEXT WEEK ONCE WE GET
THROUGH THE SUNDAY WARM EVENT AND HAVE A BETTER FEEL FOR A COUPLE
OF SNOW THREATS NEXT WEEK.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ055.
NJ...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR ANZ450>455.
GALE WARNING FROM 5 AM SUNDAY TO 6 AM EST MONDAY FOR ANZ430-
431-450>455.
&&
$$
SYNOPSIS...DRAG 408
NEAR TERM...GAINES 408
SHORT TERM...GAINES 408
LONG TERM...DRAG 408
AVIATION...DRAG/GAINES 408
MARINE...DRAG/GAINES 408
TIDES/COASTAL FLOODING...408
CLIMATE...408
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1239 AM EST SAT JAN 9 2016
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE ACROSS EASTERN CANADA AND NOSE
ITS WAY DOWN THE EASTERN SEABOARD THROUGH SATURDAY. A WARM FRONT
WILL LIFT NORTHWEST OF THE AREA TONIGHT INTO EARLY SATURDAY MORNING
AS A WEAK AREA OF LOW PRESSURE LIFTS THROUGH THE GREAT LAKES. A
STRONGER LOW PRESSURE SYSTEM WILL LIFT THROUGH THE OHIO RIVER VALLEY
INTO THE NORTHEAST SATURDAY NIGHT INTO SUNDAY, LIFTING AN OCCLUDED
FRONTAL SYSTEM ACROSS THE AREA SUNDAY. HIGH PRESSURE WILL BUILD TO
THE SOUTH MONDAY INTO MONDAY NIGHT, BEFORE AN AREA OF LOW PRESSURE
MOVES TO OUR NORTH TUESDAY INTO WEDNESDAY. THIS LOW WILL PULL A COLD
FRONT ACROSS THE AREA TUESDAY NIGHT. HIGH PRESSURE BUILDS TO OUR
SOUTH WEDNESDAY THROUGH THURSDAY, WHILE ANOTHER AREA OF LOW PRESSURE
MOVES THROUGH THE GREAT LAKES INTO NEW ENGLAND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A WARM FRONTAL BOUNDARY IS MOVING THROUGH THE REGION WITH
INCREASED MOISTURE AND SOME LIFT. THE LIFT IS SUFFICIENT ENOUGH
TO GENERATE SOME SPOTTY LIGHT PRECIPITATION. SOME CONCERN EXISTS
IN THE ADVISORY AREA ACROSS NORTHERN NEW JERSEY AND THE POCONOS
ON IF ANY MIXED PRECIPITATION WILL OCCUR. THE NAM AND GFS SHOW
THE POTENTIAL FOR A 1/100TH OR TWO OF QPF BUT THE HRRR AND RAP
ARE DRY AFTER 4AM. WILL CONTINUE WITH THE ADVISORY ATTM.
TEMPERATURES WILL FALL A COUPLE OF MORE DEGREES WITH THE
POSSIBILITY OF WET- BULBING LEADING TO ANOTHER DEGREE OR TWO OF
COOLING IN THE POCONOS. ANY MINOR ICE ACCUMULATION MAY LEAD TO
SLICK SPOTS OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
THE LIGHT PRECIPITATION SHOULD LIFT TO OUR NORTHEAST ON SATURDAY.
THE SURFACE RIDGE AXIS IS EXPECTED TO CONTINUE PULLING OUT OF OUR
REGION EVEN AS SOME MID LEVEL RIDGING DEVELOPS ALOFT.
THERE IS FORECAST TO BE A FAIR AMOUNT OF LOW LEVEL MOISTURE
LINGERING IN OUR REGION ON SATURDAY AND IT WILL LIKELY REMAIN
TRAPPED UNDER A TEMPERATURE INVERSION. AS A RESULT, WE ARE
ANTICIPATING LOW CLOUDS FOR MOST OF THE DAY.
A LIGHT NORTHEAST TO EAST WIND IS EXPECTED AND MAXIMUM TEMPERATURES
SHOULD RANGE FROM AROUND 40 IN THE POCONOS TO THE MIDDLE 50S IN
SOUTHERN DELAWARE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AFTER A WARM AND WET START TO THE FORECAST THIS WEEKEND, THEN
COOLER AIR RETURNS TO THE AREA FOR THE REMAINDER OF THE WEEK.
AN OCCLUDED LOW PRESSURE SYSTEM WILL BE LIFTING OUT OF THE OHIO
VALLEY AND INTO THE EASTERN GREAT LAKES SATURDAY NIGHT INTO
SUNDAY, PULLING THE ASSOCIATED FRONTAL BOUNDARIES ACROSS THE AREA
EARLY SUNDAY MORNING. RAIN SHOULD BEGIN OVERRUNNING THE SYSTEM AND
START MOVING INTO OUR SOUTHERN AREAS DURING THE NIGHT SATURDAY,
THEN PROGRESS NORTHWARD THROUGH THE NIGHT AND INTO SUNDAY MORNING.
PW VALUES REACH AROUND AN INCH OR MORE, AND THERE COULD ALSO BE
SOME VERY WEAK INSTABILITY. SO THERE WILL BE THE POTENTIAL FOR
PERIODS OF MODERATE TO HEAVY RAINFALL OVERNIGHT INTO EARLY SUNDAY
MORNING. WHILE THERE COULD BE A FEW LIGHTNING STRIKES OR RUMBLES
OF THUNDER, WE HAVE KEPT THUNDER OUT OF THE GRIDS FOR NOW.
RAINFALL AMOUNTS WILL LIKELY REACH AT LEAST 0.5 TO 1.0 INCHES
ACROSS MUCH OF THE AREA, AND COULD REACH 1.5 INCHES ACROSS THE
NORTHERN AREAS. WE EXPECT THIS SHOULD FALL OVER A LONG ENOUGH
PERIOD THAT WE ARE NOT EXPECTING SIGNIFICANT FLOODING AT THIS
TIME, ALTHOUGH THERE COULD END UP BEING SOME FLOOD ADVISORIES
ISSUED FOR URBAN AND POOR DRAINAGE TYPE FLOODING.
RAIN SHOULD BE TAPERING OFF THROUGH THE DAY SUNDAY AS THE LOW
PRESSURE SYSTEM AND FRONTAL BOUNDARY LIFT TO OUR NORTH. AS THE
LOW PULLS TO THE NORTH SUNDAY NIGHT INTO MONDAY, HIGH PRESSURE
BEGINS TO BUILD TO THE SOUTH. THIS WILL CREATE A TIGHT PRESSURE
GRADIENT ACROSS THE AREA AND LEAD TO GUSTY WINDS SUNDAY INTO
MONDAY. DRY WEATHER WILL CONTINUE SUNDAY NIGHT INTO MONDAY NIGHT.
THE EXCEPTION WOULD BE POSSIBLY SOME LAKE EFFECT SNOW SHOWERS
ACROSS THE NORTH EARLY SUNDAY NIGHT.
ON TUESDAY, AN AREA OF LOW PRESSURE WILL MOVE OUT OF THE GREAT
LAKES REGION INTO SOUTHEASTERN CANADA, BRINGING A FRONTAL BOUNDARY
ACROSS THE AREA LATE TUESDAY INTO TUESDAY NIGHT. THE GFS IS
BEGINNING TO SHOW BETTER POTENTIAL FOR MORE MOISTURE AND LIFT
ASSOCIATED WITH THE PASSAGE OF THE SHORT WAVE ALOFT. THE ECMWF HAS
LESS MOISTURE, BUT DOES HAVE THE ENHANCED LIFT WITH THE SHORT
WAVE. SO WE`VE EXPANDED THE SLIGHT CHANCE OF SNOW SHOWERS FROM THE
NORTHERN TIER DURING THE DAY TUESDAY, TO COVER EVERYONE TUESDAY
NIGHT. WINDS COULD GUST 20-30 MPH AT TIMES DURING THE DAY TUESDAY
AS STRONGER WINDS MIX DOWN FROM ALOFT.
THIS SYSTEM WILL MOVE QUICKLY NORTHEAST WHILE HIGH PRESSURE
BUILDS TO OUR SOUTH WEDNESDAY INTO THURSDAY. ANOTHER QUICK MOVING
LOW PRESSURE SYSTEM WILL SLIDE TO OUR NORTH THURSDAY. THE SHORT
WAVE WITH THIS SYSTEM LOOKS MORE SUBDUED THAN THE ONE WEDNESDAY,
SO WE`VE KEPT THE FORECAST DRY EXCEPT ACROSS THE POCONOS WHERE
SOME LAKE EFFECT SHOWERS COULD POSSIBLY MAKE IT DOWN INTO THE
AREA.
WINDS COULD GUST 20-30 MPH AT TIMES WEDNESDAY THROUGH THURSDAY
AS STRONGER WINDS MIX DOWN FROM ALOFT. WEDNESDAY HAS THE
POTENTIAL FOR THE STRONGEST WIND GUSTS, MAYBE 35 MPH OR HIGHER AT
TIMES.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
CEILINGS ARE FORECAST TO FAVOR THE 2000 TO 3000 FOOT RANGE AT OUR
EIGHT TAF SITES INTO THE OVERNIGHT HOURS. HOWEVER, PATCHES OF
CLOUDS WITH BASES AROUND 1500 FEET MAY DRIFT OVERHEAD FROM THE
NORTHEAST AT TIMES. ALSO, SOME BRIEF BREAKS IN THE CLOUD COVER
WILL OCCUR ESPECIALLY FOR KMIV AND KACY.
PREVAILING CEILINGS ARE EXPECTED TO LOWER INTO THE 1000 TO 2000 FOOT
RANGE BY SUNRISE. AN AREA OF LIGHT RAIN IS ANTICIPATED TO MOVE
ACROSS THE NORTHWESTERN PART OF OUR REGION AND IT IS FORECAST TO
AFFECT KRDG AND KABE...THOUGH THERE IS AT LEAST A SMALL CHANCE AT
ALL OF THE TAF SITES.
LOW LEVEL MOISTURE SHOULD REMAIN TRAPPED IN OUR REGION FOR
SATURDAY. GUIDANCE HAS BE STEADILY BECOMING MORE OPTIMISTIC WITH
THE HEIGHT OF LOW CLOUDS, SO INCREASED THE PREVAILING CLOUD BASES
THROUGH THIS TIME TO BE IN THE UPPER END OF IFR OR LOWER END OF
MVFR. KACY AND KMIV HAVE THE BEST CHANCE OF SEEING PREDOMINANTLY
MVFR CONDITIONS.
THE WIND IS FORECAST TO REMAIN FROM THE NORTHEAST THROUGH THE TAF
PERIOD AT SPEEDS OF 10 KNOTS OR LESS.
OUTLOOK...
SATURDAY NIGHT-SUNDAY...IFR CONDITIONS WITH RAIN, POSSIBLY
MODERATE TO HEAVY AT TIMES. IMPROVING LATE SUNDAY.
SUNDAY NIGHT-MONDAY...MOSTLY VFR. GUSTY WEST-NORTHWEST WINDS
DEVELOPING. GUSTS 25-30 KT POSSIBLE.
MONDAY NIGHT...VFR.
TUESDAY-WEDNESDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS
POSSIBLE TUESDAY, BECOMING WEST-NORTHWEST TUESDAY NIGHT INTO
WEDNESDAY AND REMAINING GUSTY. GUSTS AROUND 20-30 KT TUESDAY-
TUESDAY NIGHT, WITH STRONGER WINDS POSSIBLE WEDNESDAY.
&&
.MARINE...
A NORTHEAST WIND OF 5 TO 15 KNOTS IS EXPECTED ON THE COASTAL
WATERS OF NEW JERSEY AND DELAWARE FOR TONIGHT AND SATURDAY WITH A
RIDGE OF HIGH PRESSURE NOSING DOWN INTO THE NORTHEASTERN STATES
AND A STRONG STORM SYSTEM WELL OUT OVER THE WESTERN NORTH
ATLANTIC. THE STORM SHOULD KEEP WAVE HEIGHTS ON OUR OCEAN WATERS
IN THE 4 TO 6 FOOT RANGE, SO THE SMALL CRAFT ADVISORY WILL REMAIN
IN EFFECT.
OUTLOOK...
SATURDAY NIGHT...SMALL CRAFT ADVISORY EXTENDED INTO SATURDAY
NIGHT AS SEAS EXPECTED TO BUILD BACK ABOVE 5 FEET. WINDS INCREASE
25-30 KT OVERNIGHT AHEAD OF APPROACHING STORM SYSTEM.
SUNDAY-SUNDAY NIGHT...GALE WATCH IN EFFECT AS WINDS EXPECTED TO
INCREASE TO AT LEAST 35 KT AHEAD OF AND BEHIND STORM SYSTEM.
MONDAY-TUESDAY...OTHER THAN A BRIEF BREAK LATE MONDAY NIGHT INTO
TUESDAY, WINDS AND SEAS LIKELY TO REMAIN ABOVE SMALL CRAFT
CRITERIA THOUGH TUESDAY.
WEDNESDAY...THERE IS A CHANCE GALE FORCE WINDS OF 35-40 KT
WEDNESDAY.
&&
.TIDES/COASTAL FLOODING...
WITH THE NEW MOON ON SATURDAY AND AN INCREASING FLOW EASTERLY
FLOW, TIDES COULD APPROACH THE MINOR COASTAL FLOOD LEVEL.
CURRENTLY THE TIDE WITH THE HIGHEST FORECAST IS SUNDAY MORNING.
ALSO, BEHIND THE STORM SYSTEM, STRONG NORTHWEST WINDS WILL
DEVELOP. CURRENT ETSS FORECASTS IN INDICATING THE POSSIBILITY OF
APPROACHING BLOW OUT FOR SOME AREAS, ESPECIALLY THE DELAWARE BAY
AND POSSIBLY THE TIDAL DELAWARE RIVER.
&&
.CLIMATE...
WE REMAIN WITHIN A COUPLE OF DEGREES OF THE DAILY RECORD HIGHS
FOR SUNDAY JAN 10 MAY BE CHALLENGED AT MOST OF OUR CLIMATE SITES.
THEY ARE LISTED BELOW:
LOCATION RECORD YEAR
------------------------------
ATLANTIC CITY 63 1930
PHILADELPHIA 63 1950
WILMINGTON 64 1930
ALLENTOWN 60 1924
TRENTON 62 1950
GEORGETOWN 67 1950
READING 58 1939
MOUNT POCONO 57 1998
WE`LL BRING THE SNOW CLIMATOLOGY BACK EARLY NEXT WEEK ONCE WE GET
THROUGH THE SUNDAY WARM EVENT AND HAVE A BETTER FEEL FOR A COUPLE
OF SNOW THREATS NEXT WEEK.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ055.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR PAZ054-
062.
NJ...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR NJZ001.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR NJZ007-
008.
DE...NONE.
MD...NONE.
MARINE...GALE WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR
ANZ430-431-450>455.
SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY FROM 1 AM TO 6 AM EST SUNDAY FOR ANZ430-
431.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...GAINES/IOVINO/JOHNSON
SHORT TERM...IOVINO
LONG TERM...ROBERTSON
AVIATION...IOVINO/JOHNSON/ROBERTSON
MARINE...IOVINO/ROBERTSON
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1252 AM EST SAT JAN 9 2016
.SYNOPSIS...
ISSUED AT 1245 AM EST SAT JAN 9 2016
RAIN WILL MOVE BACK INTO THE AREA LATE THIS AFTERNOON AND THEN
TRANSITION TO SNOW FROM WEST TO EAST THROUGH THE EVENING AND
OVERNIGHT HOURS. THE GREATEST POTENTIAL FOR HEAVY SNOW AND SEVERAL
INCHES OF ACCUMULATION REMAINS ACROSS THE NORTHWEST CLOSER TO LAKE
MICHIGAN. FURTHER EAST...AMOUNTS WILL BE LIGHTER BUT WILL DEPEND
ON THE TIMING OF CHANGEOVER FROM RAIN TO SNOW. TEMPERATURES WILL
FALL QUICKLY TONIGHT LEADING TO A QUICK FREEZE OF WET SURFACES.
WINDS WILL ALSO INCREASE SUNDAY CREATING BLOWING AND DRIFTING
SNOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 351 PM EST FRI JAN 8 2016
ANOTHER BATCH OF RAIN (MORE SHOWERY IN NATURE WHEN COMPARED WITH
WHAT FELL EARLIER TODAY) WILL PIVOT THROUGH THIS EVENING INTO THE
EARLY OVERNIGHT AS A WELL DEFINED VORT MAX AND POCKET OF STEEPER
MID LEVEL LAPSE RATES LIFT NORTHEAST THROUGH THE LOWER LAKES.
TRAILING FRONTAL BOUNDARY THEN SETTLES IN TONIGHT INTO SATURDAY.
FORCING WANES WITH WEAK HEIGHT RISES IN BETWEEN UPPER LEVEL
WAVES...BUT STILL CANNOT RULE OUT A FEW LIGHT SHOWERS AND PATCHY
DRIZZLE IN THE VICINITY OF THIS FEATURE GIVEN AMPLE BOUNDARY LAYER
MOISTURE. AREAS OF FOG WILL ALSO REMAIN POSSIBLE THROUGH SATURDAY
MORNING ACROSS MAINLY NNW ZONES CLOSER TO SFC TROUGH.
MILD/OVERCAST OTHERWISE WITH RAIN LIKELY FILLING BACK IN ACROSS
WESTERN ZONES LATE SATURDAY AFTERNOON.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 351 PM EST FRI JAN 8 2016
SHRTWV ROUNDING BASE OF SWRN CONUS TROF TODAY WILL LIFT NE FROM THE
SRN PLAINS SATURDAY AND THROUGH THE OHIO VALLEY SATURDAY NIGHT WITH
ASSOCIATED SFC LOW MOVG FROM THE SRN PLAINS TO THE LWR GRTLKS
CAUSING RAIN CHANGING TO SNOW ACROSS OUR AREA. FCST TRACK FAVORS
EARLIER CHANGEOVER... HEAVIER SNOW IN 3-5" RANGE NW, TAPERING OFF TO
<1" SE. SNOW WILL BE HEAVY/WET INITIALLY PREVENTING
BLOWING/DRIFTING... BUT AS COLDER AIR ARRIVES AND WINDS PICK UP LATE
SAT NGT AND SUN AREAS OF BLOWING/DRIFTING SNOW EXPECTED ACROSS THE
NW PORTION OF CWA WHERE HEAVIEST ACCUMS OCCUR AND LES DVLPS. QUICK
TEMP DROP SAT NGT/SUNDAY WILL ALSO PROMOTE ICY ROAD CONDITIONS AS
MELTED SNOW REFREEZES. TOTAL SNOW ACCUMS BY SUNDAY EVE EXPECTED IN
THE 3-7" RANGE NW 1/3 OF CWA... HEAVIEST FAR NW IN COUNTIES NEAR
LAKE MICHIGAN. THIS IS MARGINAL FOR WARNING TYPE ACCUMS... BUT GIVEN
EXPECTATION OF STRONG WINDS AND FALLING TEMPS ISSUED A WINTER STORM
WATCH FOR THE NW FOR THIS TIME FRAME.
DEEP CLOSED LOW FORMING OVER SERN CANADA BY EARLY NEXT WEEK
EXPECTED TO MOVE VERY LITTLE DURING THE WEEK RESULTING IN BLO NORMAL
TEMPS ACROSS OUR AREA WHICH COMBINED WITH W-NW FLOW WILL RESULT
PERSISTENT LES NW... ENHANCED AROUND TUE AND THU BY SHRTWVS MOVG
THROUGH THE BASE OF THE TROF ACROSS THE GRTLKS. MEDIUM RANGE MODELS
HAVE HAD POOR RUN-RUN CONTINUITY ON HOW LONG THIS PATTERN WILL
PERSIST WITH 00Z RUNS SUGGESTING IT WOULD BREAK DOWN BY NEXT WEEKEND
AND LATEST RUNS KEEPING THE COLD AIR IN LONGER. COMPROMISED WITH A
SLOW CLIMB IN TEMPS FRI-SAT... BUT CONFIDENCE ON WARM-UP LATE IN THE
PERIOD IS LOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1244 AM EST SAT JAN 9 2016
AVIATION FORECAST BECOMING TRICKY AS MIXING WITHIN WARM SECTOR HAS
ERODED LOW CIGS NEAR KFWA WHILE KSBN REMAINS CLOSER TO FRONTAL
BOUNDARY AND LIFR CONDITIONS. HIRES GUIDANCE DOES NOT HAVE A GOOD
HANDLE ON THESE CONDITIONS BUT HRRR IS TRENDING TOWARD MVFR AND
VFR AT KFWA WITH KSBN IN AND OUT OF THE LOW STRATUS. HAVE KEPT
KSBN IN THE LOWER CIGS WITH TRAJECTORIES SUGGESTING LOW CLOUDS MAY
NOT LIFT OUT. WITH VFR UPSTREAM OF KFWA HAVE BEEN A BIT MORE
OPTIMISTIC THERE. CONDITIONS DETERIORATE AGAIN SATURDAY AS NEXT
WAVE LIFTS NORTH AND FRONTAL BOUNDARY SAGS FURTHER EAST. PCPN TO
DEVELOP AFTER 20Z WITH KFWA LIKELY REMAINING RAIN UNTIL VERY END
OF PERIOD WHILE KSBN LIKELY STARTS AS A RAIN AND SNOW MIX WITH
QUICK TRANSITION TO ALL SNOW TOWARD 00Z AND VLIFR CONDITIONS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
INZ003>006-012>014.
MI...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
MIZ077>080.
OH...NONE.
LM...GALE WARNING FROM 11 PM THIS EVENING TO 7 PM EST SUNDAY FOR
LMZ043-046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...STEINWEDEL
LONG TERM...JT
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1143 PM CST FRI JAN 8 2016
...AVIATION UPDATE...
.UPDATE...
ISSUED AT 1119 PM CST FRI JAN 8 2016
VISIBILITIES HAVE IMPROVED TO NO LOWER THAN 1/2 MILE ON
OBSERVATIONS IN NW IL AS W TO NW WINDS BEGIN TO RAMP UP IN THE
TIGHTENING SURFACE PRESSURE GRADIENT. HAVE THUS CANCELLED THE
REMAINING DENSE FOG ADVISORY.
&&
.SYNOPSIS...
ISSUED AT 344 PM CST FRI JAN 8 2016
LATEST SFC ANALYSIS WAS INDICATING A LOW CENTER MOVING NORTHWARD
ACRS THE WEST CENTRAL DVN CWA ATTM...WITH A ASSOCIATED FRONTAL
SYSTEM TRAILING DOWN INTO SOUTHWESTERN AR AND NORTHERN TX. THE UPPER
LEVEL LOW WAS NOTED ON WATER VAPOR IMAGERY ACRS NORTHEASTERN MO INTO
THE SOUTHERN CWA...WITH A STRONGER WAVE FURTHER UPSTREAM IN A L/W
TROF BASE DIGGING TOWARD WESTERN TX.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
TONIGHT...ASSESSING THE LATEST TRENDS AND LLVL CONVERGENT FLOW
PROPAGATION ASSOCIATED WITH THE PASSING SFC WAVE...HAVE EXTENDED THE
FOG ADVISORY TO 03Z /9 PM CST/ FOR THE WESTERN 2/3S...AND THE
NORTHWESTERN IL COUNTIES NOW INCLUDING THE EASTERN I80 CORRIDOR TIL
06Z /MIDNIGHT CST/. BUT THESE END TIMES MAY BE A BIT GENEROUS AND
THE FOLLOWING SHIFT WILL BE ABLE TO CHOP AWAY FROM THE WEST AND
SOUTH AS THE EVENING PROGRESSES...AS THE LLVL FLOW VEERS TO THE
WEST/NORTHWEST AND INCREASES. LATEST RUN HRRR VSBY PROGS NOW SHIFT
THE 1/4 MILE OR LESS VSBYS EAST OF THE MS RIVER BY 03Z THIS
EVENING.
LINGERING AREAS OF RAIN AND DRIZZLE THIS AFTERNOON AND EARLY EVENING
TO ROLL OFF TO THE NORTHEAST...WITH JUST SPOTTY LIGHTER PRECIP
WRAPPING IN BEHIND THE DEPARTING CYCLONE OUT OF NORTHWESTERN IA.
WITH POST-FRONTAL TOP DOWN COOLING...THIS PRECIP TO CHANGE OVER TO A
LIGHT RAIN/SNOW MIX THEN TO ALL LIGHT WET SNOW OVERNIGHT FROM WEST
TO EAST. LINGERING MILD GROUND TEMPS AND LACK OF PRECIP INTENSITY
SUGGESTS A WET DUSTING TO A TENTH OF AN INCH AT BEST IN AREAS THAT
GET IN ON SOME SNOW LATER TONIGHT. NORTHWEST WINDS TO RAMP UP AFTER
MIDNIGHT TO 15 TO 25 MPH IN INCOMING CANADIAN HIGH PRESSURE GRADIENT
ESPECIALLY ALONG AND WEST OF THE MS RIVER. LLVL COLD CONVEYOR TO
BE WELL IN FLUX ACRS THE AREA BY SAT MORNING.
SATURDAY...12 HR HIGH TEMPS TO OCCUR IN THE MORNING WITH FALLING
TEMPS THRU THE REST OF THE DAY. TIGHT PRESSURE GRADIENT AND STRONG
LLVL COLD AIR ADVECTION TO DIVE BRISK NORTHWEST SFC WINDS OF 15 TO
25+ MPH AND GUSTS WELL OVER 30 MPH AT TIMES. SOME LIGHT SNOW SHOWERS
OR FLURRIES MAY GET WRUNG OUT OF ANY CLOUD DECK WITH ENOUGH
SATURATED DEPTH IN THIS CAA PROCESS ESPECIALLY NORTH OF I80 BUT
LITTLE IF ANY SNOW ACCUM EXPECTED WITH THIS ACTIVITY. THEN ALL EYES
TURN TO THE MAIN SOUTHERN PLAINS LOW PRESSURE WAVE EJECTING
NORTHEASTWARD TOWARD THE MOUTH OF THE OH RIVER VALLEY BY SAT
EVENING. BULK OF THE 12Z RUN MODEL SOLUTIONS HAVE CAUGHT ON TO THE
CURRENT STRONGER SOUTHEASTWARD DIGGING PROCESS OF THE WAVE AIDED
BY UPPER JET PUNCH IN THAT DIRECTION ON IT/S WESTERN FLANK. THUS
THEY HAVE CONTINUED TO TREND FURTHER SOUTHEAST WITH THE MAIN STORM
PROPAGATION PATH. WILL ADJUST SNOW AMOUNTS ON ITS FAR NORTHWESTERN
FLANK OF IT/S DEF ZONE FURTHER DOWN AND EAST AS WELL WITH THE
LATEST THINKING. THIS ONLY PRODUCES UP TO AN INCH OF SNOW BY 00Z
SUNDAY SOUTHEAST OF A LINE GENERALLY FROM SOUTHWEST OF MACOMB
IL...TO PRINCETON IL. FURTHER WEST TOWARD THE MS RIVER MAY ONLY
GET A TENTH OR TWO...AND AREAS WEST OF THE MS RIVER MAY STAY DRY
BESIDES THE LIGHT SNOW/ FLURRIES POSSIBLE NORTH OF I80 GETTING
WRUNG OUT OF WRAP AROUND CLOUD DECK IN THE COLD AIR ADVECTION
PROCESS MENTIONED ABOVE. ANY FURTHER ADJUSTMENT EAST MEANS A NON-
EVENT/MISS FOR THE DVN CWA. ..12..
.LONG TERM...(SATURDAY NIGHT THROUGH NEXT FRIDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
COLD MID JANUARY WEATHER AND DRY TO MOSTLY DRY THROUGH LATE NEXT
WEEK.
LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE
WITH LIMITED SENSIBLE WEATHER ISSUES. MAIN CHALLENGES WILL BE BOUTS
OF FLURRIES AND POSSIBLY VERY LIGHT SNOW ON MONDAY/MONDAY NIGHT AND
AGAIN LATE NEXT WEEK. OTHERWISE...DIURNAL RANGE OF TEMPERATURES
WITH POSSIBLY SOME NEGATIVE FEEDBACK FROM GREATLY REDUCE SNOW/ICE
FIELDS.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH LOW LEVEL
THERMAL AND MOISTURE FIELDS HANDLED WELL. UPSTREAM INITIALIZATION
SUGGESTS BOTH GFS AND HI-RES ECMWF GOOD AND A ADEQUATE BLEND OF
50/50 MIX OF THESE SOLUTIONS A GOOD STARTING POINT. VERIFICATION
SUGGEST AREAS WITH NO ICE/SNOW COVER HIGHS MAY BE UP TO 3 DEGREES
TOO COLD FOR LATER SHIFTS WHILE AND SNOW/ICE COVERED LOCATIONS COULD
SEE MINS UP TO 3 DEGREES COLDER THAN FORECAST.
SATURDAY NIGHT...ONCE AGAIN HAVE TRIMMED POPS AND SNOW/QPF TOTALS AS
SYSTEM MAY PASS TO OUR SOUTHEAST. LATER SHIFTS MAY BE ABLE TO
REMOVE POPS OVER ALL BUT LOCATIONS SOUTHEAST OF A MACOMB ILLINOIS
TO PRINCETON LINE THAT MAY STILL PICK UP TO AN INCH OF A WET SNOW.
CLEARING SHOULD ARRIVE AFTER 2 AM IN NW AND ENCOMPASS ALL BUT SE 1/3
AREA BY SUNRISE. THIS SHOULD ALLOW FOR MINS AROUND ZERO DEGREES NW
SECTION TO LOWER TEENS IN FAR SOUTHEAST 1/4 WHERE CLOUDS WILL BE
DELAYED TO CLEAR AFTER SUNRISE. LATEST TRENDS SUPPORTS WIND CHILL
VALUES WILL BE MARGINAL MEETING WIND CHILL ADVISORY CRITERIA TO
AROUND -20F FOR 2 TO 5 HOURS OVER NORTHWEST 3 TO 6 COUNTIES FOR
LATER SHIFTS TO ASSESS. NORTHWEST WINDS OF 15 TO 25+ MPH WILL
DIMINISH LATE TO 10 TO 20 MPH BY MORNING.
SUNDAY...CLEAR AND QUITE COLD WITH MODERATE NORTHWEST WINDS
CONTINUING AT 10 TO 20 MPH. HIGHS SHOULD STRUGGLE INTO THE UPPER
SINGLE SINGLE DIGITS NORTHWEST TO THE MID TEENS FAR SOUTHEAST
SECTIONS WITH WIND CHILLS MOSTLY AT OR BELOW ZERO. SUNDAY NIGHT
CLEAR AND COLD WITH LIGHT WESTERLY WINDS LATE KEEPING WIND CHILLS TO
5 TO 15 BELOW ZERO. LOWS SHOULD BE ZERO TO UPPER SINGLE DIGITS WITH
FAVORED LOW LYING LOCATIONS FALLING POSSIBLY BELOW ZERO FOR LATER
SHIFTS TO REASSESS.
MONDAY AND MONDAY NIGHT...PARTLY TO MOSTLY CLOUDY WITH DECENT RISK
OF FLURRIES OR VERY LIGHT SNOW AND NOT AS COLD WITH HIGHS INTO THE
20S AHEAD OF NEXT REINFORCING SHOT OF ARCTIC AIR. MINS 5 TO 15
ABOVE AS NEXT INVASION OF ARCTIC AIR ARRIVES TOWARD MORNING IN THE
NORTHWEST. WIND CHILLS FALLING TO 10 TO 20 BELOW ZERO BY TUESDAY
MORNING.
TUESDAY...CLEAR BLUSTERY AND COLD...SIMILAR TO SUNDAY WITH HIGHS 10
TO 20 ABOVE AND POSSIBLY A FEW DEGREES COLDER THAN THIS AND
NORTHWEST WINDS OF 20 TO 30 MPH AND LOW WIND CHILLS AT OR BELOW
ZERO. TUESDAY NIGHT...MINS ZERO TO 10 ABOVE AND POSSIBLY AT LEAST
3DEGREES COLDER FOR LATER SHIFTS WITH WIND CHILLS ONCE AGAIN TO FALL
TO NEAR 15 TO 20 BELOW NORTH OF I-80.
WEDNESDAY AND THURSDAY...DRY WITH A SLOW WARMING TREND WITH HIGHS
20S WEDNESDAY AND MOSTLY 30S ON THURSDAY. MINS MOSTLY 10 TO 20
ABOVE WEDNESDAY AM AND 20S THURSDAY AM.
FRIDAY...SEASONABLY COLD AND DRY WITH HIGHS NEAR NORMAL OR MID 20S
TO LOWER 30S AND MINS MOSTLY IN THE TEENS. NICHOLS
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1142 PM CST FRI JAN 8 2016
AN AXIS OF LIGHT SNOW OVER CENTRAL IA WILL MOVE EAST THROUGH THE
TERMINALS OVERNIGHT. OTHERWISE...LINGERING LOW CLOUDS AND SLOWLY
THINNING FOG WILL KEEP LIFR TO IFR CONDITIONS IN PLACE OVERNIGHT.
A TIGHTENING FLOW BETWEEN HIGH PRESSURE OVER THE NORTHERN PLAINS
AND LOW PRESSURE PASSING THROUGH THE OHIO VALLEY REGION WILL
CAUSE NORTHWEST WINDS TO INCREASE THROUGHOUT THE TAF PERIOD...WITH
SUSTAINED SPEEDS AROUND 15 TO 20 KTS BY LATE SATURDAY INTO
SATURDAY NIGHT. AT THE SAME TIME...CIGS WILL GRADUALLY
LIFT...LEADING TO AT LEAST MVFR CONDITIONS BY SATURDAY EVENING.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...12
SHORT TERM...12
LONG TERM...NICHOLS
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1119 PM CST FRI JAN 8 2016
.UPDATE...
ISSUED AT 1119 PM CST FRI JAN 8 2016
VISIBILITIES HAVE IMPROVED TO NO LOWER THAN 1/2 MILE ON
OBSERVATIONS IN NW IL AS W TO NW WINDS BEGIN TO RAMP UP IN THE
TIGHENING SURFACE PRESSURE GRADIENT. HAVE THUS CANCELLED THE
REMAINING DENSE FOG ADVISORY.
&&
.SYNOPSIS...
ISSUED AT 344 PM CST FRI JAN 8 2016
LATEST SFC ANALYSIS WAS INDICATING A LOW CENTER MOVING NORTHWARD
ACRS THE WEST CENTRAL DVN CWA ATTM...WITH A ASSOCIATED FRONTAL
SYSTEM TRAILING DOWN INTO SOUTHWESTERN AR AND NORTHERN TX. THE UPPER
LEVEL LOW WAS NOTED ON WATER VAPOR IMAGERY ACRS NORTHEASTERN MO INTO
THE SOUTHERN CWA...WITH A STRONGER WAVE FURTHER UPSTREAM IN A L/W
TROF BASE DIGGING TOWARD WESTERN TX.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
TONIGHT...ASSESSING THE LATEST TRENDS AND LLVL CONVERGENT FLOW
PROPAGATION ASSOCIATED WITH THE PASSING SFC WAVE...HAVE EXTENDED THE
FOG ADVISORY TO 03Z /9 PM CST/ FOR THE WESTERN 2/3S...AND THE
NORTHWESTERN IL COUNTIES NOW INCLUDING THE EASTERN I80 CORRIDOR TIL
06Z /MIDNIGHT CST/. BUT THESE END TIMES MAY BE A BIT GENEROUS AND
THE FOLLOWING SHIFT WILL BE ABLE TO CHOP AWAY FROM THE WEST AND
SOUTH AS THE EVENING PROGRESSES...AS THE LLVL FLOW VEERS TO THE
WEST/NORTHWEST AND INCREASES. LATEST RUN HRRR VSBY PROGS NOW SHIFT
THE 1/4 MILE OR LESS VSBYS EAST OF THE MS RIVER BY 03Z THIS
EVENING.
LINGERING AREAS OF RAIN AND DRIZZLE THIS AFTERNOON AND EARLY EVENING
TO ROLL OFF TO THE NORTHEAST...WITH JUST SPOTTY LIGHTER PRECIP
WRAPPING IN BEHIND THE DEPARTING CYCLONE OUT OF NORTHWESTERN IA.
WITH POST-FRONTAL TOP DOWN COOLING...THIS PRECIP TO CHANGE OVER TO A
LIGHT RAIN/SNOW MIX THEN TO ALL LIGHT WET SNOW OVERNIGHT FROM WEST
TO EAST. LINGERING MILD GROUND TEMPS AND LACK OF PRECIP INTENSITY
SUGGESTS A WET DUSTING TO A TENTH OF AN INCH AT BEST IN AREAS THAT
GET IN ON SOME SNOW LATER TONIGHT. NORTHWEST WINDS TO RAMP UP AFTER
MIDNIGHT TO 15 TO 25 MPH IN INCOMING CANADIAN HIGH PRESSURE GRADIENT
ESPECIALLY ALONG AND WEST OF THE MS RIVER. LLVL COLD CONVEYOR TO
BE WELL IN FLUX ACRS THE AREA BY SAT MORNING.
SATURDAY...12 HR HIGH TEMPS TO OCCUR IN THE MORNING WITH FALLING
TEMPS THRU THE REST OF THE DAY. TIGHT PRESSURE GRADIENT AND STRONG
LLVL COLD AIR ADVECTION TO DIVE BRISK NORTHWEST SFC WINDS OF 15 TO
25+ MPH AND GUSTS WELL OVER 30 MPH AT TIMES. SOME LIGHT SNOW SHOWERS
OR FLURRIES MAY GET WRUNG OUT OF ANY CLOUD DECK WITH ENOUGH
SATURATED DEPTH IN THIS CAA PROCESS ESPECIALLY NORTH OF I80 BUT
LITTLE IF ANY SNOW ACCUM EXPECTED WITH THIS ACTIVITY. THEN ALL EYES
TURN TO THE MAIN SOUTHERN PLAINS LOW PRESSURE WAVE EJECTING
NORTHEASTWARD TOWARD THE MOUTH OF THE OH RIVER VALLEY BY SAT
EVENING. BULK OF THE 12Z RUN MODEL SOLUTIONS HAVE CAUGHT ON TO THE
CURRENT STRONGER SOUTHEASTWARD DIGGING PROCESS OF THE WAVE AIDED
BY UPPER JET PUNCH IN THAT DIRECTION ON IT/S WESTERN FLANK. THUS
THEY HAVE CONTINUED TO TREND FURTHER SOUTHEAST WITH THE MAIN STORM
PROPAGATION PATH. WILL ADJUST SNOW AMOUNTS ON ITS FAR NORTHWESTERN
FLANK OF IT/S DEF ZONE FURTHER DOWN AND EAST AS WELL WITH THE
LATEST THINKING. THIS ONLY PRODUCES UP TO AN INCH OF SNOW BY 00Z
SUNDAY SOUTHEAST OF A LINE GENERALLY FROM SOUTHWEST OF MACOMB
IL...TO PRINCETON IL. FURTHER WEST TOWARD THE MS RIVER MAY ONLY
GET A TENTH OR TWO...AND AREAS WEST OF THE MS RIVER MAY STAY DRY
BESIDES THE LIGHT SNOW/ FLURRIES POSSIBLE NORTH OF I80 GETTING
WRUNG OUT OF WRAP AROUND CLOUD DECK IN THE COLD AIR ADVECTION
PROCESS MENTIONED ABOVE. ANY FURTHER ADJUSTMENT EAST MEANS A NON-
EVENT/MISS FOR THE DVN CWA. ..12..
.LONG TERM...(SATURDAY NIGHT THROUGH NEXT FRIDAY)
ISSUED AT 344 PM CST FRI JAN 8 2016
COLD MID JANUARY WEATHER AND DRY TO MOSTLY DRY THROUGH LATE NEXT
WEEK.
LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE
WITH LIMITED SENSIBLE WEATHER ISSUES. MAIN CHALLENGES WILL BE BOUTS
OF FLURRIES AND POSSIBLY VERY LIGHT SNOW ON MONDAY/MONDAY NIGHT AND
AGAIN LATE NEXT WEEK. OTHERWISE...DIURNAL RANGE OF TEMPERATURES
WITH POSSIBLY SOME NEGATIVE FEEDBACK FROM GREATLY REDUCE SNOW/ICE
FIELDS.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH LOW LEVEL
THERMAL AND MOISTURE FIELDS HANDLED WELL. UPSTREAM INITIALIZATION
SUGGESTS BOTH GFS AND HI-RES ECMWF GOOD AND A ADEQUATE BLEND OF
50/50 MIX OF THESE SOLUTIONS A GOOD STARTING POINT. VERIFICATION
SUGGEST AREAS WITH NO ICE/SNOW COVER HIGHS MAY BE UP TO 3 DEGREES
TOO COLD FOR LATER SHIFTS WHILE AND SNOW/ICE COVERED LOCATIONS COULD
SEE MINS UP TO 3 DEGREES COLDER THAN FORECAST.
SATURDAY NIGHT...ONCE AGAIN HAVE TRIMMED POPS AND SNOW/QPF TOTALS AS
SYSTEM MAY PASS TO OUR SOUTHEAST. LATER SHIFTS MAY BE ABLE TO
REMOVE POPS OVER ALL BUT LOCATIONS SOUTHEAST OF A MACOMB ILLINOIS
TO PRINCETON LINE THAT MAY STILL PICK UP TO AN INCH OF A WET SNOW.
CLEARING SHOULD ARRIVE AFTER 2 AM IN NW AND ENCOMPASS ALL BUT SE 1/3
AREA BY SUNRISE. THIS SHOULD ALLOW FOR MINS AROUND ZERO DEGREES NW
SECTION TO LOWER TEENS IN FAR SOUTHEAST 1/4 WHERE CLOUDS WILL BE
DELAYED TO CLEAR AFTER SUNRISE. LATEST TRENDS SUPPORTS WIND CHILL
VALUES WILL BE MARGINAL MEETING WIND CHILL ADVISORY CRITERIA TO
AROUND -20F FOR 2 TO 5 HOURS OVER NORTHWEST 3 TO 6 COUNTIES FOR
LATER SHIFTS TO ASSESS. NORTHWEST WINDS OF 15 TO 25+ MPH WILL
DIMINISH LATE TO 10 TO 20 MPH BY MORNING.
SUNDAY...CLEAR AND QUITE COLD WITH MODERATE NORTHWEST WINDS
CONTINUING AT 10 TO 20 MPH. HIGHS SHOULD STRUGGLE INTO THE UPPER
SINGLE SINGLE DIGITS NORTHWEST TO THE MID TEENS FAR SOUTHEAST
SECTIONS WITH WIND CHILLS MOSTLY AT OR BELOW ZERO. SUNDAY NIGHT
CLEAR AND COLD WITH LIGHT WESTERLY WINDS LATE KEEPING WIND CHILLS TO
5 TO 15 BELOW ZERO. LOWS SHOULD BE ZERO TO UPPER SINGLE DIGITS WITH
FAVORED LOW LYING LOCATIONS FALLING POSSIBLY BELOW ZERO FOR LATER
SHIFTS TO REASSESS.
MONDAY AND MONDAY NIGHT...PARTLY TO MOSTLY CLOUDY WITH DECENT RISK
OF FLURRIES OR VERY LIGHT SNOW AND NOT AS COLD WITH HIGHS INTO THE
20S AHEAD OF NEXT REINFORCING SHOT OF ARCTIC AIR. MINS 5 TO 15
ABOVE AS NEXT INVASION OF ARCTIC AIR ARRIVES TOWARD MORNING IN THE
NORTHWEST. WIND CHILLS FALLING TO 10 TO 20 BELOW ZERO BY TUESDAY
MORNING.
TUESDAY...CLEAR BLUSTERY AND COLD...SIMILAR TO SUNDAY WITH HIGHS 10
TO 20 ABOVE AND POSSIBLY A FEW DEGREES COLDER THAN THIS AND
NORTHWEST WINDS OF 20 TO 30 MPH AND LOW WIND CHILLS AT OR BELOW
ZERO. TUESDAY NIGHT...MINS ZERO TO 10 ABOVE AND POSSIBLY AT LEAST
3DEGREES COLDER FOR LATER SHIFTS WITH WIND CHILLS ONCE AGAIN TO FALL
TO NEAR 15 TO 20 BELOW NORTH OF I-80.
WEDNESDAY AND THURSDAY...DRY WITH A SLOW WARMING TREND WITH HIGHS
20S WEDNESDAY AND MOSTLY 30S ON THURSDAY. MINS MOSTLY 10 TO 20
ABOVE WEDNESDAY AM AND 20S THURSDAY AM.
FRIDAY...SEASONABLY COLD AND DRY WITH HIGHS NEAR NORMAL OR MID 20S
TO LOWER 30S AND MINS MOSTLY IN THE TEENS. NICHOLS
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 545 PM CST FRI JAN 8 2016
WEAK WINDS AND LOW LEVEL MOISTURE UNDER A SLOW MOVING LOW
PRESSURE SYSTEM WILL KEEP VLIFR TO LIFR CONDITIONS DUE TO DENSE
FOG AND DRIZZLE IN PLACE AT MLI...DBQ AND CID FOR MUCH OF THE
EVENING. IFR CONDITIONS WILL CONTINUE AT BRL. AS THE SYSTEM LIFTS
OUT...WINDS WILL VEER TO THE WEST AND THEN NORTHWEST AND INCREASE
LATE TONIGHT INTO SATURDAY MORNING. THIS WILL BRING IMPROVING
VISIBILITIES...GRADUALLY LIFTING CIGS...AND PRECIPITATION OF A
MORE SCATTERED NATURE IN THE FORM OF DRIZZLE AND RAIN...CHANGING
OVER TO LIGHT SNOW. SCATTERED SNOW SHOWERS WILL BE POSSIBLE
THROUGH SATURDAY WITH GUSTY NORTH TO NORTHWEST WINDS. CIGS AND
VISIBILITIES SHOULD IMPROVE TO IFR IF NOT MVFR THROUGH THE
DAY...BUT FORECAST CONFIDENCE IN THE RATE OF IMPROVEMENT IS LOW.
FOR NOW...WILL REMAIN BIASED TOWARD SLOWER IMPROVEMENT OR MORE
PESSIMISTIC CONDITIONS THROUGHOUT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...12
SHORT TERM...12
LONG TERM...NICHOLS
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
223 AM MST SAT JAN 9 2016
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 223 AM MST SAT JAN 9 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS A
LONGWAVE TROUGH ACROSS THE CENTRAL US ACROSS THE GLD CWA WITH A
CLOSED CENTER ROTATING OVER WESTERN OK TO THE SOUTHEAST. AN
AMPLIFIED RIDGE IN IN PLACE ACROSS THE WESTERN US UPSTREAM. AT THE
SURFACE CANADIAN HIGH PRESSURE EXTENDS SOUTH ACROSS THE NORTHERN
PLAINS ACROSS OUR CWA.
THIS MORNING-THIS AFTERNOON...WEAK FORCING BENEATH LONGWAVE TROUGH
HAS COMBINED WITH A SATURATED LAYER FROM 925-700 MB AND STEEP LOW
LOW LEVEL LAPSE RATES TO SUPPORT POCKETS OF FLURRIES ACROSS THE
AREA. AS THE CLOSED UPPER LOW TO THE SOUTHEAST MOVES EAST AND
SHORTWAVE RIDGING BUILDS INTO THE ROCKIES MUCH DRIER/STABLE AIR
SHOULD LEAD TO THIS ACTIVITY DISSIPATING. THERE COULD STILL BE A FEW
FLURRIES POSSIBLE THROUGH MIDDAY...HOWEVER OVERALL TREND SHOULD BE
FOR THIS TO END DURING THE MORNING HOURS. CAA WILL CONTINUE THIS
MORNING THROUGH THE AFTERNOON...AND IN LOCATIONS WITH PERSISTENT
CLOUD COVER WE COULD SEE HIGHS STRUGGLE TO REACH 20F. THERE IS SOME
INDICATION THAT WE COULD SEE BREAKS IN CLOUD COVER THIS
AFTERNOON...WHICH MAY ALLOW TEMPS (MAINLY SOUTH OF I-70) TO REACH
30F.
TONIGHT-MONDAY NIGHT...AMPLIFIED NW FLOW WILL BE IN PLACE ACROSS THE
PLAINS WITH MAIN STORM TRACK SPLIT AROUND OUR CWA. THERE WILL BE A
SERIES OF CLIPPERS ROTATING THROUGH THE MEAN FLOW...HOWEVER ANY
IMPACT ON SENSIBLE WEATHER OVER OUR CWA SHOULD BE LIMITED TO
INCREASES IN HIGH CLOUD COVER THROUGH THESE PERIODS.
REGARDING TEMPERATURES...THERE WILL BE A SLIGHT MODERATION IN THE
AIR MASS TONIGHT...HOWEVER WITH CANADIAN HIGH PRESSURE STILL BE A
STRONG INFLUENCE ON OUR TEMPS. THE QUESTION IS CLOUD COVER AND TDS AS
WITH CLEARING SKIES AND TDS ON DRIER END OF GUIDANCE COULD SUPPORT
LOWS NEAR ZERO AT SOME LOCATIONS. GUIDANCE SHOWS HIGH CLOUD COVER
INCREASING LATE WHICH LOWERS CONFIDENCE IN IDEAL RADIATIONAL
CONDITIONS. WEAK LEE TROUGH DEVELOPS IN EASTERN COLORADO/WYOMING
WITH DOWNSLOPE FLOW SUPPORTING CONTINUED MODERATION OF THE AIR MASS
THROUGH MONDAY. UPSTREAM SNOW FIELD AND PERIODS OF CLOUD COVER (AND
WINDS DURING THE NIGHT PERIODS) ALL LOWER CONFIDENCE IN TEMPS
THROUGH THE PERIODS. I STUCK WITH SIMILAR TRENDS AS PREVIOUS
FORECAST WITH HIGHS RETURNING TO SEASONAL VALUES AROUND 42 BY
MONDAY...AND OVERNIGHT LOWS IN THE SINGLE DIGITS (WEST) TO THE
TEENS(EAST). A QUICK MOVING SHORTWAVE TROUGH AND PASSING COLD FRONT
COMPLICATES LOWS MONDAY NIGHT...THOUGH WITH CAA IN PLACE EVEN CLOUD
COVER MAY NOT KEEP LOWS FROM DROPPING INTO THE TEENS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 117 AM MST SAT JAN 9 2016
MODELS CONTINUE TO NOT DO VERY WELL IN THIS TIME PERIOD. A LOT OF
SPREAD REMAINS NOT ONLY WITH THE DETERMINISTIC OUTPUT BUT ALSO THE
ENSEMBLES. MODELS DISAGREE ON HOW AMPLIFIED OR NOT THE FLOW IS WITH
THE OUTPUT OUT OF PHASE BY THE END OF THE PERIOD. ESSENTIALLY THE
FLOW REMAINS WEST TO NORTHWEST AND SOMETIMES EVEN MORE NORTH.
SO MOST OF THE WAVES GOING THROUGH LOOK TO BE OPEN AND FAST MOVING.
SO LITTLE TO NO CHANCE TO GET PRECIPITATION IN THIS SCENARIO. ONE OF
THOSE SHORTWAVES MOVES THROUGH IN THE THURSDAY TO FRIDAY TIME FRAME
AND BRINGS IN A MUCH COLDER AIR MASS. THE COMBINATION OF THE
SHORTWAVE AND COLD AIR ADVECTION SHOULD BE ABLE TO PRODUCE A SMALL
CHANCE OF LIGHT SNOW WHICH IS WHAT THE CRH_INIT GAVE ME FOR FRIDAY
WHICH IS REASONABLE.
WHAT LOOKS TO BE THE MOST UNCERTAIN IS THE TEMPERATURE FORECAST. IN
THIS FLOW COULD POSSIBLY GET A COLD SURGE/BACK DOOR COLD FRONT
MOVING INTO THE AREA. THE INIT GAVE ME WARMER TEMPERATURES IN THE
MIDDLE TO UPPER 40S ON WEDNESDAY AND THURSDAY...WHICH I WILL LEAVE
ALONE FOR NOW DUE TO MODEL DISAGREEMENT...BUT THERE IS DEFINITE
POTENTIAL FOR COLDER TEMPERATURES THOSE DAYS...DEPENDING OF COURSE
ON WHICH MODELS MID/UPPER SOLUTION WORKS OUT.
FRIDAY DEFINITELY LOOKS COLDER AND EVEN INTO THE REMAINDER OF NEXT
WEEKEND. THE PATTERN THE MODEL OUTPUT IS SHOWING...EVEN THOUGH
SHOWING DIFFERENCES...IS CONDUCIVE TO MUCH COLDER TEMPERATURES.
OVERALL NO CHANGES WILL BE MADE TO THE CRH_INIT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 915 PM MST FRI JAN 8 2016
KGLD...MVFR CIGS EXPECTED AT TAF ISSUANCE FOR AN HOUR OR SO BEFORE
VFR CONDITIONS RETURN FOR THE REST OF THE TAF PERIOD. WINDS
THROUGH THE PERIOD FROM THE NORTH AROUND 10KTS.
KMCK...VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH WINDS FROM
THE NORTH NEAR 10KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...99
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1146 PM CST FRI JAN 8 2016
.AVIATION...
THE BACK EDGE OF A LARGE AREA OF SHOWERS AND EMBEDDED TSTMS...HAS
SHIFTED EAST OF I-49...AND WILL CONTINUE TO AFFECT KMLU AND KELD
THRU AROUND 08-10Z. MOSTLY LOW MVFR TO OCNL IFR CIGS AND VRBL
VSBYS EXPECTED WITHIN THIS RAIN. ISOLD CONVECTION HAS BEGUN TO
REDEVELOP NEAR THE KTXK TERMINAL...AND AREAS OF FOG DEVELOPING
OVER PORTIONS OF NE TX. VSBYS RECENTLY FELL UNDER A MILE AT
KTYR...KLFK...AND NEARBY NACOGDOCHES. VSBYS WILL IMPROVE WITH THE
ONSET OF STG COLD FRONT MOVG INTO SE OK/NE TX BY AROUND
09/12Z...WITH A FEW SHOWERS POSSIBLY REDEVELOPING NEAR FRONT.
MOSTLY WNW WINDS INCREASING TO AT LEAST 15 KTS AREAWIDE DURG DAY
WITH PASSAGE OF COLD FRONT...AND NE TX MAY SEE GUSTS OVER 30 KTS.
A STUBBORN LOW LVL INVERSION WILL KEEP MOST CIGS IN MVFR CAT THRU
THE AFTN...AND POSSIBLY BEYOND 10/00Z...WITH NW WINDS ONLY
DECREASING TO 10 TO 15 KTS AFTER 10/00Z./VII/.
&&
.PREV DISCUSSION... /ISSUED 1124 PM CST FRI JAN 8 2016/
DISCUSSION...
A LATE ZONE UPDATE WAS JUST SENT FOR THE EXPIRATION OF SVR WATCH
#1 FOR DEEP E TX/SABINE PARISH LA. DRY SLOTTING IS EVIDENT ON THE
RADAR AND WATER VAPOR IMAGERY THIS EVENING WELL AHEAD OF THE
SHORTWAVE TROUGH ROTATING THROUGH FAR W TX. AS HAS BEEN THE CASE
FOR MUCH OF THIS EVENING...STILL CAN`T RULE OUT ISOLATED HAILERS
FROM THE STRONGER STORMS EMBEDDED IN THE CONVECTION OVER NCNTRL
LA/SCNTRL AR GIVEN THE STEEP LAPSE RATES ALOFT AND LOW WET BULB
ZERO HEIGHTS EVIDENT ON THE 00Z KSHV/KFWD RAOBS...BUT THIS
CONVECTION IS BECOMING MORE REMOVED FROM THE BEST SOURCE OF
MUCAPE...WHICH REMAINS OVER S LA AND RANGES FROM 500-1000 J/KG.
THE ONGOING CONVECTION SHOULD QUICKLY DIMINISH FROM W TO E ACROSS
N LA/SCNTRL AR BETWEEN 06-09Z...ALTHOUGH THE 00Z NAM/GFS AND
LATEST HRRR RUNS DEPICT ADDITIONAL CONVECTION DEVELOPMENT LATE
TONIGHT OVER E TX...WHICH MAY BUILD NE INTO SW AR/EXTREME NW LA BY
DAYBREAK SATURDAY ALONG/JUST AHEAD OF A COLD FRONT AND ATTENDENT
TROUGH AXIS...WHICH REMAINS JUST NW OF THE REGION OVER ECNTRL
TX/SE OK/WRN AR.
HAVE LOWERED POPS TO MID CHANCE LATE TONIGHT FOR THESE
AREAS...WITH ISOLATED THUNDER STILL POSSIBLE GIVEN THE STEEP LAPSE
RATES ALOFT AHEAD OF THE TROUGH. HAVE KEPT LIKELY POPS OVER THE
ERN ZONES LATE FOR THE ONGOING CONVECTION...WITH THE TROUGH
EXPECTED TO OPEN UP AND LIFT NE INTO THE MID-SOUTH AND OH VALLEY
SATURDAY. ANY CONVECTION N OF I-20 SATURDAY MORNING SHOULD
DIMINISH BY AFTERNOON AS THIS SYSTEM PULLS AWAY FROM THE
REGION...AND COLDER AIR SPILLS SE IN WAKE OF THE FRONT. ONLY MADE
MINOR TWEAKS TO THE FORECAST MIN TEMPS...WITH TEMPS ONLY EXPECTED
TO FALL OFF A FEW MORE DEGREES AT BEST ACROSS MUCH OF THE
REGION...AS WE AWAIT THE ARRIVAL OF THE FRONT LATE.
PORTIONS OF NE TX/SE OK/SW AR MAY NEED A LAKE WIND ADVISORY FOR
THE STRONG POST-FRONTAL WINDS SATURDAY EVEN BENEATH THE STRATOCU
FIELD...BUT WILL DEFER THIS DECISION TO THE MID SHIFT.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 51 55 33 45 / 60 30 10 10
MLU 55 62 35 45 / 100 30 10 10
DEQ 47 50 26 42 / 50 40 10 10
TXK 49 52 29 42 / 40 40 10 10
ELD 51 57 30 44 / 100 50 10 10
TYR 45 50 30 44 / 40 20 10 10
GGG 49 52 30 44 / 40 20 10 10
LFK 52 56 32 48 / 20 20 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1124 PM CST FRI JAN 8 2016
.DISCUSSION...
A LATE ZONE UPDATE WAS JUST SENT FOR THE EXPIRATION OF SVR WATCH
#1 FOR DEEP E TX/SABINE PARISH LA. DRY SLOTTING IS EVIDENT ON THE
RADAR AND WATER VAPOR IMAGERY THIS EVENING WELL AHEAD OF THE
SHORTWAVE TROUGH ROTATING THROUGH FAR W TX. AS HAS BEEN THE CASE
FOR MUCH OF THIS EVENING...STILL CAN`T RULE OUT ISOLATED HAILERS
FROM THE STRONGER STORMS EMBEDDED IN THE CONVECTION OVER NCNTRL
LA/SCNTRL AR GIVEN THE STEEP LAPSE RATES ALOFT AND LOW WET BULB
ZERO HEIGHTS EVIDENT ON THE 00Z KSHV/KFWD RAOBS...BUT THIS
CONVECTION IS BECOMING MORE REMOVED FROM THE BEST SOURCE OF
MUCAPE...WHICH REMAINS OVER S LA AND RANGES FROM 500-1000 J/KG.
THE ONGOING CONVECTION SHOULD QUICKLY DIMINISH FROM W TO E ACROSS
N LA/SCNTRL AR BETWEEN 06-09Z...ALTHOUGH THE 00Z NAM/GFS AND
LATEST HRRR RUNS DEPICT ADDITIONAL CONVECTION DEVELOPMENT LATE
TONIGHT OVER E TX...WHICH MAY BUILD NE INTO SW AR/EXTREME NW LA BY
DAYBREAK SATURDAY ALONG/JUST AHEAD OF A COLD FRONT AND ATTENDENT
TROUGH AXIS...WHICH REMAINS JUST NW OF THE REGION OVER ECNTRL
TX/SE OK/WRN AR.
HAVE LOWERED POPS TO MID CHANCE LATE TONIGHT FOR THESE
AREAS...WITH ISOLATED THUNDER STILL POSSIBLE GIVEN THE STEEP LAPSE
RATES ALOFT AHEAD OF THE TROUGH. HAVE KEPT LIKELY POPS OVER THE
ERN ZONES LATE FOR THE ONGOING CONVECTION...WITH THE TROUGH
EXPECTED TO OPEN UP AND LIFT NE INTO THE MID-SOUTH AND OH VALLEY
SATURDAY. ANY CONVECTION N OF I-20 SATURDAY MORNING SHOULD
DIMINISH BY AFTERNOON AS THIS SYSTEM PULLS AWAY FROM THE
REGION...AND COLDER AIR SPILLS SE IN WAKE OF THE FRONT. ONLY MADE
MINOR TWEAKS TO THE FORECAST MIN TEMPS...WITH TEMPS ONLY EXPECTED
TO FALL OFF A FEW MORE DEGREES AT BEST ACROSS MUCH OF THE
REGION...AS WE AWAIT THE ARRIVAL OF THE FRONT LATE.
PORTIONS OF NE TX/SE OK/SW AR MAY NEED A LAKE WIND ADVISORY FOR
THE STRONG POST-FRONTAL WINDS SATURDAY EVEN BENEATH THE STRATOCU
FIELD...BUT WILL DEFER THIS DECISION TO THE MID SHIFT.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PREV DISCUSSION... /ISSUED 626 PM CST FRI JAN 8 2016/
AVIATION...
DESPITE A LOW LVL INVERSION WHICH HAS TRAPPED IFR CIGS AND LOW
VSBYS ACROSS SOUTHERN PORTIONS OF THE AREA...MAINLY AT KLFK AND
KMLU...STEEP ELEVATED INSTABILITY ABOVE THE INVERSION IS ALLOWING
FOR SCATTERED TSTMS TO DEVELOP. THESE CONDITIONS...ALONG WITH
DRIER AIR IN MID LVLS AND LOW FRZG LVLS...IS ENHANCING HAIL
DEVELOPMENT IN THESE STORMS. CONVECTION MAY REMAIN MORE ISOLD
ACROSS NW PORTIONS OF AREA...INCLUDING KTYR...KGGG...AND KTXK.
CONVECTION MOVG NEWD AT 30 TO 40 KTS. MOSTLY LGT SOUTH WINDS AND
WETTING RAINS WILL ALSO ALLOW FOR CONTINUED LOW CIGS AND REDUCED
VSBYS AT REMAINING TERMINAL SITES OVERNIGHT. A STG COLD FRONT WILL
MOVE ACROSS AREA MID TO LATE MORNING ON SATURDAY. WINDS WILL SHIFT
TO THE SW-W...BEFORE SHIFTING AGAIN TO THE WNW THRU THE AFTN
HOURS. WINDS MAY INCREASE TO 15 TO 25 KTS OVER NE TX PORTION OF
THE AREA. LOW POSTFRONTAL STRATOCU MAY HOLD IN PLACES DURG THE
DAY...ALTHOUGH SOME SCATTERING OUT OF LOW CIGS IS POSSIBLE. /VII/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 51 55 33 45 / 60 30 10 10
MLU 55 62 35 45 / 100 30 10 10
DEQ 47 50 26 42 / 50 40 10 10
TXK 49 52 29 42 / 40 40 10 10
ELD 51 57 30 44 / 100 50 10 10
TYR 45 50 30 44 / 40 20 10 10
GGG 49 52 30 44 / 40 20 10 10
LFK 52 56 32 48 / 20 20 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1258 AM EST SAT JAN 9 2016
.SYNOPSIS...
A WEAK FRONT WILL LIFT NORTHWARD THROUGH THE REGION TONIGHT AND
BRING A BRIEF PERIOD OF SNOW SLEET AND FREEZING RAIN. A SECOND
SYSTEM WILL MOVE IN FROM THE SOUTH SATURDAY NIGHT AND SUNDAY WITH
WIDESPREAD RAIN EXPECTED THROUGH SUNDAY AFTERNOON. AS THIS SYSTEM
EXITS A COLD AIR MASS WILL PUSH IN FROM THE NORTHWEST AND CHANGE
THE LINGERING RAIN OVER TO SNOW. A PERSISTENT WEST WIND WILL ALLOW
FOR LAKE EFFECT SNOW SHOWERS THROUGH MOST OF THE WEEK ACROSS THE
FINGER LAKES AND INTO THE TUG HILL PLATEAU. SIGNIFICANT SNOW
ACCUMULATIONS ARE POSSIBLE.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
855 PM UPDATE...
TWO POSITIVE SIGNS: TEMPERATURES ARE NOT FALLING AS QUICKLY AS
FEARED, AND THE RADAR PICTURE IS MORE SPARSE THAN EXPECTED. FOR
THIS REASON, WE BELIEVE LIGHT FREEZING RAIN WILL BE ISOLATED.
WE RAISED TEMPERATURES THROUGH THE NEXT 3-6 HOURS AND CUT BACK ON
THE POPS, MOVING MORE IN LINE WITH THE HRRR AND NAM12 RADAR PROGS.
350 PM UPDATE... A WINTER WEATHER ADVISORY FOR FREEZING RAIN IS
IN EFFECT TONIGHT FOR PORTIONS OF CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA.
A WEAK WARM FRONT CURRENTLY MOVING NEWD THROUGH OH/WV/VA THIS
AFTERNOON WILL SPREAD A NARROW BAND OF PRECIPITATION THROUGH THE
REGION TONIGHT. A LAYER OF MID LVL WAA COMBINED WITH A WEAK UPPER
S/W WILL TRIGGER AN INITIAL BAND OF PRECIP EARLY THIS EVENING. THE
SIGNIFICANT FACTOR WILL BE THE PRESENCE OF A WEDGE OF AIR BELOW
FREEZING NEAR THE SURFACE. A COLD AREA OF HIGH PRESSURE OVER ERN
QUEBEC EXTENDING SWD INTO NEW ENGLAND AND NOSING WWD INTO THE NRN
APPALACHIAN MTNS WILL KEEP A COLD AIR MASS IN PLACE AS THE WARM
AIR RIDES OVER THE TOP AND CREATES FAVORABLE THERMAL PROFILES FOR
FREEZING RAIN. ONE AREA OF CONCERN WILL BE THE NRN EDGE OF THE
ALLEGHENY MTNS IN THE HIGHER TERRAIN OF BRADFORD AND WYOMING
COUNTIES MAINLY THIS EVENING AND INTO THE EARLY OVERNIGHT. THE
SECOND AREA OF CONCERN WILL BE LOCATIONS EAST OF I-81 FROM THE SRN
TUG HILL PLATEAU INTO THE POCONO MTNS WHERE THE COLDEST SFC TEMPS
WILL BE LOCATED. THE FREEZING RAIN/DRIZZLE MAIN END UP LINGERING A
BIT LONGER AS THE BAND OF PRECIP EXITS TO THE E/NE SAT MORNING.
ICE ACCUMULATIONS WILL GENERALLY BE LESS THAN A TENTH OF AN
INCH...ALONG WITH LIGHT SNOW AMTS MIXED IN AT TIMES AS WELL. AREA
ROADS THAT ARE NOT TREATED MAY BECOME SLIPPERY TONIGHT AND
SATURDAY MORNING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
350 PM UPDATE... A WEAK RIDGE IS EXPECTED TO BUILD IN BEHIND THE
DEPARTING WARM FRONT/ UPPER TROUGH THROUGH THE DAY SATURDAY WITH
LINGERING LIGHT RAIN AND/OR DRIZZLE INTO SATURDAY NIGHT. A MUCH
MORE DYNAMIC STORM SYSTEM WILL LIFT NEWD FROM THE OHIO VALLEY INTO
THE WRN GREAT LAKES DURING THE DAY SUNDAY. A RELATIVELY STRONG
PUSH OF MOISTURE FROM THE SOUTH WILL BECOME ENTRAINED INTO THE
SYSTEM AND PRODUCE MODERATE PERSISTENT RAIN ACROSS THE REGION
THROUGH SUNDAY AFTERNOON. PWAT VALUES AROUND 0.8 INCH WITH THIS
SYSTEM WILL ALLOW FOR A HALF INCH TO 1.5 INCHES OF RAINFALL ON
SUNDAY. RAINFALL AMOUNTS SHOULD NOT BE SIGNIFICANT ENOUGH FOR
HYDRO ISSUES.
A STRONG PUSH OF COLD AIR WILL DEVELOP ON THE BACK SIDE OF THE
SYSTEM BEHIND THE COLD FRONT SUNDAY NIGHT AND ALLOW THE RAIN TO
MIX WITH INITIALLY AND EVENTUALLY CHANGE OVER TO ALL SNOW.
SNOWFALL AMOUNTS WILL NOT ADD UP TO MUCH AS THE AIR MASS BEHIND
THE FRONT IS EXPECTED TO BE RELATIVELY DRY. THIS ARCTIC AIR MASS
WILL BE FAVORABLE FOR LAKE EFFECT SNOW...AND THE TRAJECTORIES FROM
THE WEST WILL ALLOW FOR LES BANDS TO SET UP EAST OF LAKE ERIE AND
EAST OF ONTARIO...POSSIBLY IMPACTING STEUBEN COUNTY WITH LIGHT
SNOW AND THE SRN TUG HILL PLATEAU WITH EVEN MORE SNOW.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
350 PM UPDATE... THE COLD ARCTIC PATTERN WILL REMAIN IN PLACE
THROUGH MOST OF THE WEEK WITH 850MB TEMPS AROUND -15 TO -20 DEG C
BLOWING ACROSS RELATIVELY WARM LAKES OF ERIE AND ONTARIO. THE
DETERMINING FACTOR FOR WHERE THE HEAVIEST SNOW WILL SET UP WILL BE
THE RESULTING WIND FIELD. A WESTERLY WIND WILL KEEP THE BEST
CHANCE OF ACCUMULATING LES OVER NRN ONEIDA COUNTY MONDAY AND
TUESDAY...BUT SHIFT THE BAND TO THE NORTH TUE NIGHT AS THE NEXT
WEAK CLIPPER SYSTEM MOVES IN FROM THE WEST AND BACKS THE WINDS TO
THE SSW. THIS COLD S/W WILL TRIGGER ADDITIONAL MORE WIDESPREAD
SNOW SHOWERS LATE TUE INTO WED...BUT AMOUNTS WILL BE LIGHT AS THE
AIR MASS IS EXPECTED TO BE VERY DRY. THE COLD AIR ALOFT WILL
INDUCE THE STEEP LOW LEVEL LAPSE RATES AND BE THE MAIN DRIVING
FORCE FOR THE SNOW PRODUCTION.
AS THE SYSTEM EXITS EAST...WINDS WILL VEER TO THE NW LATE
WEDNESDAY AND COMBINE WITH ANOTHER PUSH OF ARCTIC AIR TO PRODUCE
ADDITIONAL LAKE EFFECT SNOW INTO WED NIGHT. THE PATTERN REPEATS
THURSDAY INTO FRIDAY WITH THE PASSAGE OF ANOTHER S/W AND
ADDITIONAL LIGHT ACCUMULATING SNOW SHOWERS.
TEMPERATURES WILL REMAIN NEAR NORMAL MOST OF THE WEEK WITH HIGHS
IN THE MID TO UPPER 20S AND LOWS IN THE TEENS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE EARLY MORNING
HOURS WITH SCT SHRA AND PATCHY DZ. CIGS HAVE ALREADY LOWERED TO
FUEL ALT KITH-KELM-KBGM...WHILE OTHER TERMINALS ARE TEETERING INTO
HIGH END MVFR BUT WILL EVENTUALLY ALSO ACHIEVE FUEL ALT. FOR
KBGM...MOIST UPSLOPE AND PATCHY DRIZZLE IN THE HOURS AROUND DAWN
SHOULD EVEN RESULT IN IFR AT TIMES...THOUGH FOR KITH DUE TO
DOWNSLOPING THAT WILL BE HARDER TO ACHIEVE UNTIL A WEAK WAVE
PASSES WITH ANOTHER BATCH OF LIGHT SHOWERS OR DRIZZLE TO ADD
MOISTURE THIS AFTERNOON /EVEN THEN IT WILL BE INTERMITTENT/. AS
MOISTENING CONTINUES...IFR CIG SHOULD BECOME PREDOMINANT FOR KBGM
LATE MORNING THROUGH AFTERNOON AND PROBABLY EVEN LOWERING FURTHER
THIS EVENING. IFR WILL ALSO EVENTUALLY BE REALIZED THIS EVENING
KAVP ONCE LOW LEVEL FLOW BACKS TO A RESTRICTION-FAVORABLE LIGHT
NORTHEASTERLY. GENERALLY SPEAKING HOWEVER...WIND FOR MOST
TERMINALS IF NOT LIGHT-VARIABLE WILL BE ESE-SSE 5-10 KTS...SEE
TAFS FOR SPECIFICS. ALSO...AT KRME- KSYR...BECAUSE OF LOCALIZED
TERRAIN-INDUCED ESE SURFACE WIND VERSUS A S-SSW LOW LEVEL JET
AROUND 40 KTS...THERE WILL BE A PERIOD OF MARGINAL LLWS EARLY THIS
MORNING.
WINDS E/SE 5-10 KNOTS.
.OUTLOOK...
SUN...RESTRICTIONS LIKELY FROM SOLID BATCH OF RAIN SHOWERS
ESPECIALLY EARLY MORNING TO MIDDAY. LINGERING RAIN SHOWERS MAY CHANGE
OVER TO SNOW SNOW SHOWERS WHILE DIMINISHING SUNDAY NIGHT.
MON/TUE/WED...VFR...BUT SPOTTY MVFR/IFR PSBL IN LAKE EFFECT SNOW
SHWRS OVER NY STATIONS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR PAZ039-
040-044-048-072.
WINTER WEATHER ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
PAZ038-043.
NY...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR NYZ009-
036-037-045-046-056-057-062.
&&
$$
SYNOPSIS...BJT
NEAR TERM...BJT/DJP
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
245 AM EST SAT JAN 09 2016
.SYNOPSIS...A RIDGE OF COOL HIGH PRESSURE AT THE SURFACE WITH
PLENTIFUL MOISTURE ALOFT WILL KEEP UNSETTLED WEATHER THROUGH
SATURDAY NIGHT... AS A STRONG STORM SYSTEM APPROACHES FROM THE WEST
AND MOVES THROUGH THE REGION. THIS SYSTEM WILL EXIT ON SUNDAY WITH
CLEARING SKIES AND DRIER WEATHER THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 240 AM SATURDAY...
THROUGH THIS MORNING... WIDESPREAD FOG AND THICK STRATUS ARE LIKELY
TO PERSIST WITHIN THE WEDGE REGIME... FEATURING A DAMMING SURFACE
HIGH CENTERED OFF THE CANADIAN MARITIMES NOSING SW INTO NC... CAPPED
BY WEAK BUT STEADY MOIST UPGLIDE. BLOCKED BY THE MOUNTAINS TO THE
WEST AND A FRONTAL ZONE WELL TO OUR SOUTH AND SE... THE WEDGE SHOULD
STAY LOCKED IN WELL INTO THE MORNING GIVEN THE STAGNANT SURFACE
AIR... PROFOUND CLOUD DEPTH... AND LACK OF ANY MECHANISM TO DISPERSE
IT IN THE VERTICAL. THE HRRR AND HRRR-X ARE STILL SHOWING INCREASING
FOG DENSITY THROUGH DAYBREAK... AND WHILE THIS IS FAR FROM CERTAIN
GIVEN THE EXTENT OF STRATUS... WILL KEEP A CLOSE EYE ON FOG
TRENDS... AND DENSE FOG ADVISORY MAY BE NEEDED THIS MORNING. THE
MOIST UPGLIDE DOESN`T APPEAR TO BE STRONG OR DEEP ENOUGH FOR
ANYTHING MORE THAN PATCHY DRIZZLE OVER THE NEXT SEVERAL HOURS... AND
OTHER FORCING MECHANISMS ARE LACKING AS WELL GIVEN THE DEPARTURE TO
OUR NE OF A BATCH OF MID LEVEL VORTICITY... SO POPS THROUGH THIS
MORNING WILL BE LOW. TEMPS WILL BE SLOW TO RISE THROUGH THE UPPER
40S AND LOW-MID 50S THIS MORNING.
MIDDAY TODAY THROUGH TONIGHT: THE ACTIVE SOUTHERN STREAM REACHES ITS
PEAK IMPACT ON THE SOUTHEAST STATES LATE THIS AFTERNOON AND TONIGHT
WITH PASSAGE OF A POTENT MID LEVEL SHORTWAVE TROUGH AND SURFACE LOW
TO OUR WEST AND NW... MOVING FROM THE LOWER MISS VALLEY NEAR MIDDAY
THROUGH THE TN AND ERN OH VALLEY THROUGH TONIGHT. WHILE THE CHANCE
OF EVERYONE SEEING AT LEAST SOME SHOWERS (AND PERHAPS A STORM OR
TWO... MORE ON THAT LATER) IS HIGH CONSIDERING THE PROJECTIONS OF
MUCH ABOVE NORMAL PW (0.90-1.20")... IT APPEARS THAT THE BULK OF THE
DYNAMIC FORCING FOR ASCENT WILL HOLD TO OUR WEST AND NORTH. THESE
MECHANISMS INCLUDES THE MID LEVEL DPVA WITH THE SHORTWAVE TROUGH AS
WELL AS THE STRONGEST UPPER DIVERGENCE WITH THE LEFT EXIT REGION OF
THE SUBTROPICAL JET... BOTH OF WHICH TAKE A PATH NW OF CENTRAL NC.
BUT THERE SHOULD STILL BE A STRONG INFLUX OF LOWER LEVEL MOISTURE...
FOCUSED INTO CENTRAL AND ERN NC OUT AHEAD OF A WEAK SURFACE LOW NOW
OVER SOUTH FLA AND EXPECTED TO TRACK NORTHWARD TODAY AND THROUGH
CENTRAL NC TONIGHT... DRAWING ENOUGH ATLANTIC MOISTURE INTO THE AREA
FOR A PERIOD OF CATEGORICAL POPS... FOCUSING LATE AFTERNOON THROUGH
TONIGHT... WITH GREATEST COVERAGE AND DURATION OCCURRING ACROSS THE
NRN AND ERN FORECAST AREA. AS THIS SURFACE LOW APPROACHES AND DRAWS
THE COASTAL WEDGE FRONT WESTWARD INTO THE NC COASTAL PLAIN THIS
EVENING/TONIGHT... WEAK INSTABILITY (PEAKING AT A MUCAPE OF ABOUT
500-1000 J/KG TONIGHT) ALONG WITH IMPRESSIVE DEEP LAYER SHEAR AOA 50
KTS COULD SUPPORT A FEW POCKETS OF STRONGER CONVECTION... MOST
LIKELY (ACCORDING TO THE LATEST MODEL RUNS) DURING THE EARLY TO MID
EVENING HOURS. IT`S UNCLEAR WHETHER OR NOT ANY WEAK INSTABILITY WILL
BE ACHIEVED DURING THE TIME OF GREATEST LOW LEVEL SHEAR (0-3 KM SRH
PREDICTED TO REACH 300-400 M2/S2 ON THE NAM AND ABOUT HALF THAT ON
THE GFS)... WHICH WOULD INFLUENCE THE THREAT OF SUPERCELLS. SUCH A
SCENARIO SEEMS UNLIKELY BUT THE POTENTIAL WILL BE MONITORED. IF
SURFACE DEWPOINTS OVER OUR EAST CLIMB INTO THE UPPER 50S TO AROUND
60 AS EXPECTED HOWEVER... WITH WINDS BECOMING MORE UNIDIRECTIONAL (A
STRAIGHTENING HODOGRAPH)... THERE COULD BE A RISK OF BOWING SEGMENTS
AND STRONG STRAIGHT LINE WINDS TONIGHT. WILL RESTRICT AN ISOLATED
MENTION OF THUNDER TONIGHT FROM RALEIGH EAST AND SOUTH... ALONG AND
EAST OF THE ANTICIPATED TRACK OF THE WEAK SURFACE LOW. THE
WARM/WEDGE FRONT WILL SHIFT BACK EAST OVER THE COASTAL PLAIN LATE
TONIGHT AS THE OCCLUDED FRONT APPROACHES. EXPECT HIGHS FROM THE
UPPER 40S TO NEAR 50 IN THE TRIAD TO NEAR 60 IN OUR FAR SE (CLINTON
TO GOLDSBORO). TEMPS SHOULD SLIP JUST A FEW DEGREES EARLY TONIGHT...
TO THE MID 40S NW TO MID-UPPER 50S SE... WITH STEADY TEMPS OR A
SLIGHT RISE OVERNIGHT. -GIH
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 245 AM SATURDAY...
CONSENSUS OF THE LATEST MODELS IS TO SHIFT THE FRONTAL ZONE AND
ATTENDANT PRECIP EAST OUT OF THE COASTAL PLAIN SUN MORNING... WITH
THE ONSET OF BRISK AND GUSTY SW WINDS... SHIFTING TO WESTERLY LATE
IN THE DAY... AS THE SECONDARY COLD FRONT (TRAILING THE POTENT
SURFACE LOW THAT WILL ACCOMPANY THE VORTICITY/UPPER DIVERGENCE MAX
UP THROUGH LAKE ERIE/LAKE ONTARIO) PUSHES EAST INTO THE AREA LATE.
LOW LEVEL THICKNESSES START TO DROP SUNDAY MORNING BUT WILL
INITIALLY BE OFFSET BY INCREASING SUNSHINE AND THE DELAY IN COLD AIR
ADVECTION. HIGHS SHOULD BE IN THE MID 50S TO LOWER 60S EARLY IN THE
DAY... WITH READINGS SLIPPING LATER IN THE DAY. WITH THE TIGHT MSLP
GRADIENT IN THE WAKE OF THE LAKE ERIE LOW... SUSTAINED WINDS OF 15-
20 KTS APPEAR LIKELY... WITH FREQUENT GUSTS TO AROUND 30 MPH... BOTH
LIGHTENING UP LATE IN THE DAY. MOSTLY CLEAR SUN NIGHT WITH
DIMINISHING WINDS AND WINDS BECOMING WNW AS COLDER AIR RUSHES IN.
LOWS 25-33. -GIH
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 230 AM SATURDAY...
THE WORK WEEK BEGINS WITH HIGH PRESSURE IN PLACE OVER THE DEEP SOUTH
AND SOUTHWESTERLY FLOW ALOFT WHICH WILL KEEP CENTRAL NC DRY WITH
SLIGHTLY BELOW NORMAL TEMPERATURES IN PLACE AS HIGHS WILL CLIMB INTO
THE LOW TO MID 40S MONDAY WITH LOWS IN THE MID TO UPPER 20S.
MODERATION OF THE TEMPERATURES WILL INCREASE ON TUESDAY AS THICKNESS
VALUES RISE ABOUT 15 METERS...THUS CORRESPONDING TO ABOUT A 5 DEGREE
TEMPERATURE INCREASE FOR HIGHS ON TUESDAY. EXPECT MID 40S IN THE NW
PIEDMONT TO NEAR 50 DEGREES IN THE SOUTHEAST.
THAT IS WHERE THE MODERATION ENDS HOWEVER AS A COLD FRONT COMES
RUSHING INTO THE AREA TUESDAY NIGHT AND EARLY WEDNESDAY MORNING.
THIS WILL KEEP LOWS BELOW FREEZING WEDNESDAY MORNING...MID 20S TO
NEAR 30 DEGREES. A VERY STRONG PRESSURE GRADIENT WILL ACCOMPANY THE
FRONTAL PASSAGE AND GUSTY WINDS CAN BE EXPECTED. ACCORDING TO GFS
BUFFER SOUNDINGS...GUSTS COULD BE AS HIGH AS 25 KTS BASED ON
MOMENTUM TRANSFER TO THE SURFACE. RIGHT NOW MODELS REMAIN DRY...BUT
A BRIEF FLURRY OR TWO CANT BE RULED OUT AS THE UPPER TROUGH MOVES
THROUGH EARLY WEDNESDAY MORNING. NO IMPACTS ARE EXPECTED ASIDE FROM
VERY STRONG COLD AIR ADVECTION. THIS WILL KEEP MAX TEMPERATURES DOWN
IN THE UPPER 30S ACROSS THE NORTH TO LOW 40S IN THE SOUTHERN TIER.
LOWS IN THE MIDDLE 20S.
AFTER THE UPPER TROUGH CROSSES THE AREA WEDNESDAY MORNING...SURFACE
HIGH PRESSURE OVER THE SOUTH WILL BEGIN TO MIGRATE NORTHEASTWARD OVER
THE CAROLINAS...RELAXING THE PRESSURE GRADIENT. SOUTHWESTERLY FLOW
ALOFT WILL ONCE AGAIN MODERATE TEMPERATURES BACK INTO THE MID TO
UPPER 40S ON THURSDAY AFTERNOON WITH UPPER 20S TO LOWER 30S THURSDAY
NIGHT.
MODELS DIFFER IN THE APPROACH OF A LOW PRESSURE SYSTEM THAT FORMS
OVER THE WESTERN GULF OF MEXICO WEDNESDAY NIGHT AND ENDS UP
SOMEWHERE OFF OF THE EAST COAST ON FRIDAY MORNING. THE GFS SOLUTION
KEEPS THE LOW OFF OF THE COAST ON FRIDAY BUT THE ECMWF DOUSES
CENTRAL NC WITH PRECIPITATION FRIDAY MORNING. AT THIS TIME...IT
APPEARS MOST OF THE PRECIPITATION WOULD BE LIQUID AS TEMPERATURES
MODERATE INTO THE UPPER 40S TO LOWER 50S. AGAIN A FLURRY CANT BE
RULED OUT AT THE ONSET OF PRECIPITATION IN THE NORTHWEST PIEDMONT
BUT AS OF NOW THIS WOULD BE A RAIN EVENT. PLENTY OF TIME FOR THINGS
TO CHANGE AS THE PARENT LOW HASN`T BEGUN TO FORM YET.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1230 AM SATURDAY...
...WIDESPREAD FOG OVERNIGHT THROUGH SATURDAY MORNING...
HIGH CONFIDENCE IN ADVERSE AVIATION CONDITIONS TONIGHT THROUGH MUCH
OF SAT MORNING... WITH ONLY SLOW IMPROVEMENT THEREAFTER. A WEDGE OF
COOL HIGH PRESSURE WILL CONTINUE TO NOSE IN FROM THE NE AT THE
SURFACE... WHILE DEEP MOISTURE STREAMS INTO THE AREA JUST OFF THE
SURFACE. THIS WILL KEEP DEEP LOW IFR/LIFR CLOUDS OVER THE REGION
WITH WIDESPREAD IFR FOG... SOME OF IT NEARING LIFR/VLIFR LATE
TONIGHT. THE STAGNANT AIR MASS AND CLOUD DEPTH WILL KEEP THESE
ADVERSE CONDITIONS LOCKED IN LONGER THAN USUAL SAT MORNING... AS IT
MAY BE LATE MORNING OR THE NOON HOUR BEFORE WE ACHIEVE MVFR
CONDITIONS AT CENTRAL NC AIRFIELDS. AN APPROACHING STORM SYSTEM FROM
THE SOUTH AND SW WILL THEN BRING INCREASING CHANCE FOR SHOWERS AND
ISOLATED STORMS STARTING SAT AFTERNOON AND LASTING THROUGH SAT
NIGHT... WITH CONDITIONS AGAIN DETERIORATING TO IFR LATE SAT
AFTERNOON THROUGH SAT NIGHT. AVIATION INTERESTS SHOULD BE ALERT FOR
STRONG WINDS FROM THE SE AT 1500-3000 FT AGL PRECEDING THE FRONT SAT
NIGHT... PARTICULARLY AS WE APPROACH 06Z.
LOOKING BEYOND 06Z SAT NIGHT... POOR AVIATION CONDITIONS WILL
PERSIST UNTIL PASSAGE OF A COLD FRONT FROM WEST TO EAST LATE SAT
NIGHT INTO SUN MORNING. THE STRONG WINDS FROM THE SE JUST OFF THE
GROUND WILL CONTINUE TO INCREASE AND VEER TO SOUTHERLY OR
SOUTHWESTERLY LATE SAT NIGHT INTO SUN MORNING. THUNDERSTORMS ARE
POSSIBLE SAT NIGHT ESPECIALLY AFFECTING RWI/FAY. CLEARING SKIES AND
A TREND TO VFR ARE EXPECTED SUNDAY... ALTHOUGH STRONG GUSTY WINDS
FROM THE WEST ARE LIKELY POST-FRONT. VFR CONDITIONS ARE EXPECTED TO
DOMINATE THROUGH WED... ALTHOUGH GUSTY WINDS MAY RETURN WITH A DRY
COLD FRONT PASSAGE TUE NIGHT/WED. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS NORMAN OK
1205 AM CST SAT JAN 9 2016
.UPDATE...
A RELATIVELY SMALL BAND OF MODERATE PRECIPITATION CONTINUES TO
MOVE INTO OUR NORTH TEXAS COUNTIES IN THE PROXIMITY OF THE UPPER
LOW. LOW-LEVEL TEMPERATURES HAVE REMAINED UP THOUGH AS ALTUS
REMAINS 36 WITH PRIMARILY RAIN AND KNOX CITY IS 39. MAY HAVE A
SLIVER OF AIR COOL ENOUGH FOR SNOW IN THE QUANAH/HOLLIS AREA AS
CHILDRESS IS NOW REPORTING SNOW. WILL CONTINUE TO WATCH FOR
OVERLAP OF THIS PRECIP AND COOLER LOW-LEVEL TEMPERATURES OVERNIGHT
ACROSS SOUTHWEST AND CENTRAL. THE PRIMARY AREA OF SNOW MAY BE
ACROSS WEST CENTRAL OKLAHOMA WHERE SOMEWHAT HIGHER REFLECTIVITIES
PERSIST ACROSS CUSTER/DEWEY COUNTIES. WE DID RECEIVE A TWITTER
PICTURE OF AN INCH OF SNOW ACCUMULATION AT HAMMON ABOUT AN HOUR
AGO... SO COULD SEE SOME ISOLATED AREAS WITH A TOUCH MORE THAN 2
INCHES. BUT THIS BAND OF MODERATE PRECIP IS RATHER NARROW AND
OTHERWISE INTENSITY TRENDS HAVE BEEN DOWNWARD...SO MOST AREAS WILL
REMAIN LESS.
&&
.PREV DISCUSSION... /ISSUED 1049 PM CST FRI JAN 8 2016/
DISCUSSION...
AVIATION DISCUSSION FOR THE 06Z TAFS IS BELOW.
AVIATION...
THE TAFS REMAIN CHALLENGING OVER THE NEXT 24 HOURS. CONFIDENCE
IS RATHER LOW THROUGH 15Z.
THROUGH 12Z...GENERALLY THINK MVFR CONDITIONS WILL OCCUR IN MOST
LOCATIONS. PATCHES OF IFR/LIFR CONDITIONS WILL OCCUR AS WELL...
ESPECIALLY WHERE -SN OCCURS.
PRECIPITATION TYPE SHOULD BE -SN AT MOST SITES. KSPS MAY HAVE A
-RAPLSN MIX THROUGH 10Z.
AFTER 12Z...CONDITIONS WILL IMPROVE NORTH TO SOUTH. BELIEVE ALL
SITES WILL BE VFR BY 21Z. ANY -SN WILL END BY 16Z.
NORTH WINDS WILL BECOME GUSTY AT MANY SITES BY 12Z...THEN WEAKEN
AFTER 23Z.
MBS
PREV DISCUSSION... /ISSUED 959 PM CST FRI JAN 8 2016/
UPDATE...
COMPLICATED FORECAST THIS EVENING. UPPER LOW SPINNING NEAR LUBBOCK
WILL MOVE EAST-NORTHEAST TOWARD THE RED RIVER VALLEY. MEANWHILE
COLD LOW-LEVEL AIR IS FILTERING SOUTHEAST. LOW LEVELS ARE COOL
ENOUGH TO CHANCE PRECIP TO SNOW AS FAR SOUTH AS ERICK/ELK CITY.
RAP AND HRRR SHOW PRIMARY PRECIP BAND NEAR LUBBOCK MAY PIVOT UP
THE I-44 CORRIDOR FROM ROUGHLY CROWELL TO LAWTON TO OKLAHOMA
CITY... BUT WILL THE LOW LEVELS BE COOL ENOUGH FOR PRECIP TO BE
PRIMARILY SNOW WHEN MODERATE PRECIPITATION IS FALLING? WILL BE
WATCHING THIS CLOSELY TO SEE IF THE ADVISORY MAY NEED TO BE
EXPANDED SOUTHEAST A LITTLE BIT THIS EVENING OR OVERNIGHT.
MEANWHILE... THE PRECIPITATION IS LIGHTER FARTHER NORTH... BUT
DURATION OF LIGHT SNOW MAY STILL BE SUFFICIENT FOR AN INCH OR TWO
OF SNOW IN WESTERN AND PORTIONS OF NORTHERN OKLAHOMA... SO WILL
KEEP THE ADVISORY UP THERE. VISIBILITY IN THE AREAS OF SNOW IN
NORTHWEST OKLAHOMA AND THE TEXAS PANHANDLES HAVE GENERALLY BEEN
3-5 MILES SO IT DOES NOT SEEM LIKE IT WILL ACCUMULATE TOO QUICKLY.
DID ISSUE ONE UPDATE EARLIER THIS EVENING TO ACCOUNT FOR CURRENT
TRENDS... AND WILL LET THAT RIDE FOR THE NOW.
PREV DISCUSSION... /ISSUED 303 PM CST FRI JAN 8 2016/
DISCUSSION...
WE EARLIER ISSUED A WINTER WEATHER ADVISORY FOR MUCH OF OUR
FORECAST AREA...BASED ON VERY AGGRESSIVE SNOWFALL AMOUNTS
ADVERTISED BY MOST OF THE FORECAST MODELS AVAILABLE AT THE TIME.
MORE-RECENT TRENDS IN THE MODELS HAVE ADDED A GREAT DEAL OF
UNCERTAINTY TO THE FORECAST...BY PLACING SNOW BANDS IN VARYING
PLACES...WITH FAR LESS GEOGRAPHICAL/TEMPORAL AGREEMENT THAN
BEFORE. AS A RESULT...WE HAVE SMOOTHED THE SNOWFALL FORECAST A
LOT...REMOVING STORM TOTAL AMOUNTS GREATER THAN 2 INCHES. OUR BEST
ESTIMATE AT THIS TIME...HOWEVER...STILL SUPPORTS A WINTER WEATHER
ADVISORY OVER ESSENTIALLY THE SAME AREA AS BEFORE...JUST LESS
CERTAINTY ABOUT SNOWFALL TOTALS. THERE IS STILL A GOOD CHANCE THAT
A STRIPE OF LAND WILL BE COVERED WITH 2 TO 4 INCHES OF SNOW...BUT
IT IS MUCH HARDER TO SAY WHERE THAT STRIPE WILL BE.
SO...WE ARE MAKING NO CHANGES AT THIS ISSUANCE TO EITHER THE
TIMING OR THE GEOGRAPHICAL BOUNDARIES OF OUR ADVISORY. THE
SNOWFALL AMOUNTS HAVE BEEN LOWERED SIGNIFICANTLY IN THE AREA
ROUGHLY FROM MANGUM TO ENID. OTHERWISE...THERE IS NOT MUCH CHANGE
IN THIS PART OF THE FORECAST.
WE HAVE MADE SOME VERY SHORT-RANGE ADJUSTMENTS ALSO TO POPS TO
ACCOMMODATE THE CURRENT RADAR TRENDS. A BAND OF RAIN IS DEVELOPING
FROM NEAR WICHITA FALLS TO SHAWNEE...AND THIS MAY LATER CONVERT
INTO A SNOW BAND LATE TONIGHT...ONCE TEMPERATURES ALOFT FALL
ENOUGH TO MAKE THE CHANGEOVER.
SNOW SHOULD END DURING THE DAY TOMORROW...AND THERE IS NOT MUCH OF
INTEREST IN THE REST OF THE FORECAST. AFTER A COLDER-THAN-AVERAGE
WEEKEND...TEMPERATURES WILL BEGIN A SLOW WARMING TREND THAT WILL
LAST THROUGH NEXT WEEK. ANOTHER DISTURBANCE MAY BRING SOME SHOWERS
TO THE AREA ON THURSDAY.
OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR OKZ004>025-
033>036.
TX...WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR TXZ083.
$$
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 30 35 18 30 / 70 20 0 0
HOBART OK 29 37 18 33 / 70 10 0 0
WICHITA FALLS TX 34 42 22 39 / 60 20 0 0
GAGE OK 25 34 13 34 / 70 10 0 0
PONCA CITY OK 29 32 13 31 / 60 20 0 0
DURANT OK 37 41 24 37 / 60 20 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR OKZ004>025-
033>036.
TX...WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR TXZ083.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
1049 PM CST FRI JAN 8 2016
.DISCUSSION...
AVIATION DISCUSSION FOR THE 06Z TAFS IS BELOW.
&&
.AVIATION...
THE TAFS REMAIN CHALLENGING OVER THE NEXT 24 HOURS. CONFIDENCE
IS RATHER LOW THROUGH 15Z.
THROUGH 12Z...GENERALLY THINK MVFR CONDITIONS WILL OCCUR IN MOST
LOCATIONS. PATCHES OF IFR/LIFR CONDITIONS WILL OCCUR AS WELL...
ESPECIALLY WHERE -SN OCCURS.
PRECIPITATION TYPE SHOULD BE -SN AT MOST SITES. KSPS MAY HAVE A
-RAPLSN MIX THROUGH 10Z.
AFTER 12Z...CONDITIONS WILL IMPROVE NORTH TO SOUTH. BELIEVE ALL
SITES WILL BE VFR BY 21Z. ANY -SN WILL END BY 16Z.
NORTH WINDS WILL BECOME GUSTY AT MANY SITES BY 12Z...THEN WEAKEN
AFTER 23Z.
MBS
&&
.PREV DISCUSSION... /ISSUED 959 PM CST FRI JAN 8 2016/
UPDATE...
COMPLICATED FORECAST THIS EVENING. UPPER LOW SPINNING NEAR LUBBOCK
WILL MOVE EAST-NORTHEAST TOWARD THE RED RIVER VALLEY. MEANWHILE
COLD LOW-LEVEL AIR IS FILTERING SOUTHEAST. LOW LEVELS ARE COOL
ENOUGH TO CHANCE PRECIP TO SNOW AS FAR SOUTH AS ERICK/ELK CITY.
RAP AND HRRR SHOW PRIMARY PRECIP BAND NEAR LUBBOCK MAY PIVOT UP
THE I-44 CORRIDOR FROM ROUGHLY CROWELL TO LAWTON TO OKLAHOMA
CITY... BUT WILL THE LOW LEVELS BE COOL ENOUGH FOR PRECIP TO BE
PRIMARILY SNOW WHEN MODERATE PRECIPITATION IS FALLING? WILL BE
WATCHING THIS CLOSELY TO SEE IF THE ADVISORY MAY NEED TO BE
EXPANDED SOUTHEAST A LITTLE BIT THIS EVENING OR OVERNIGHT.
MEANWHILE... THE PRECIPITATION IS LIGHTER FARTHER NORTH... BUT
DURATION OF LIGHT SNOW MAY STILL BE SUFFICIENT FOR AN INCH OR TWO
OF SNOW IN WESTERN AND PORTIONS OF NORTHERN OKLAHOMA... SO WILL
KEEP THE ADVISORY UP THERE. VISIBILITY IN THE AREAS OF SNOW IN
NORTHWEST OKLAHOMA AND THE TEXAS PANHANDLES HAVE GENERALLY BEEN
3-5 MILES SO IT DOES NOT SEEM LIKE IT WILL ACCUMULATE TOO QUICKLY.
DID ISSUE ONE UPDATE EARLIER THIS EVENING TO ACCOUNT FOR CURRENT
TRENDS... AND WILL LET THAT RIDE FOR THE NOW.
PREV DISCUSSION... /ISSUED 303 PM CST FRI JAN 8 2016/
DISCUSSION...
WE EARLIER ISSUED A WINTER WEATHER ADVISORY FOR MUCH OF OUR
FORECAST AREA...BASED ON VERY AGGRESSIVE SNOWFALL AMOUNTS
ADVERTISED BY MOST OF THE FORECAST MODELS AVAILABLE AT THE TIME.
MORE-RECENT TRENDS IN THE MODELS HAVE ADDED A GREAT DEAL OF
UNCERTAINTY TO THE FORECAST...BY PLACING SNOW BANDS IN VARYING
PLACES...WITH FAR LESS GEOGRAPHICAL/TEMPORAL AGREEMENT THAN
BEFORE. AS A RESULT...WE HAVE SMOOTHED THE SNOWFALL FORECAST A
LOT...REMOVING STORM TOTAL AMOUNTS GREATER THAN 2 INCHES. OUR BEST
ESTIMATE AT THIS TIME...HOWEVER...STILL SUPPORTS A WINTER WEATHER
ADVISORY OVER ESSENTIALLY THE SAME AREA AS BEFORE...JUST LESS
CERTAINTY ABOUT SNOWFALL TOTALS. THERE IS STILL A GOOD CHANCE THAT
A STRIPE OF LAND WILL BE COVERED WITH 2 TO 4 INCHES OF SNOW...BUT
IT IS MUCH HARDER TO SAY WHERE THAT STRIPE WILL BE.
SO...WE ARE MAKING NO CHANGES AT THIS ISSUANCE TO EITHER THE
TIMING OR THE GEOGRAPHICAL BOUNDARIES OF OUR ADVISORY. THE
SNOWFALL AMOUNTS HAVE BEEN LOWERED SIGNIFICANTLY IN THE AREA
ROUGHLY FROM MANGUM TO ENID. OTHERWISE...THERE IS NOT MUCH CHANGE
IN THIS PART OF THE FORECAST.
WE HAVE MADE SOME VERY SHORT-RANGE ADJUSTMENTS ALSO TO POPS TO
ACCOMMODATE THE CURRENT RADAR TRENDS. A BAND OF RAIN IS DEVELOPING
FROM NEAR WICHITA FALLS TO SHAWNEE...AND THIS MAY LATER CONVERT
INTO A SNOW BAND LATE TONIGHT...ONCE TEMPERATURES ALOFT FALL
ENOUGH TO MAKE THE CHANGEOVER.
SNOW SHOULD END DURING THE DAY TOMORROW...AND THERE IS NOT MUCH OF
INTEREST IN THE REST OF THE FORECAST. AFTER A COLDER-THAN-AVERAGE
WEEKEND...TEMPERATURES WILL BEGIN A SLOW WARMING TREND THAT WILL
LAST THROUGH NEXT WEEK. ANOTHER DISTURBANCE MAY BRING SOME SHOWERS
TO THE AREA ON THURSDAY.
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR OKZ004>025-
033>036.
TX...WINTER WEATHER ADVISORY UNTIL NOON CST SATURDAY FOR TXZ083.
&&
$$
26/17/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
204 AM EST SAT JAN 9 2016
.SYNOPSIS...
A LIGHT COATING OF FREEZING RAIN IS POSSIBLE OVER THE MOUNTAINS
TONIGHT AS WARMER AIR SPREADS ACROSS THE REGION. A STRONG LOW
PRESSURE SYSTEM WILL TAKE A PATH WEST AND NORTH OF PENNSYLVANIA
SATURDAY NIGHT INTO EARLY SUNDAY. AN UPPER LEVEL TROUGH WILL THEN
PIVOT THROUGH THE NORTHEAST CONUS DURING THE FIRST HALF OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
REGIONAL RADAR LOOP AND NEAR TERM MDL DATA SUPPORT OCNL LGT RAIN
CONTINUING ACROSS NORTHWEST PA THRU DAWN IN ASSOC WITH WEAK
SHORTWAVE LIFTING NE ACROSS THE GRT LKS. WEAKER LG SCALE FORCING
ACROSS THE SE HALF OF THE STATE SHOULD RESULT IN LITTLE MORE THAN
DRIZZLE IN THAT AREA.
07Z MESONET SFC OBS INDICATE NEARLY THE ENTIRE AREA IS ABV
FREEZING. HOWEVER...WILL HOLD ONTO THE ADVISORY FOR A FEW MORE
HOURS TO ACCOUNT FOR POSSIBLE ICY SPOTS WHERE GROUND TEMPS REMAIN
BLW FREEZING. NCAR MESO ENSEMBLE OUTPUT SUGGESTS THE BEST CHC OF
ADDITIONAL ICING BTWN 07Z-10Z WILL BE OVR THE MTNS NORTH OF KIPT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TODAY/...
NO SIG RAIN EXPECTED LATER TODAY...AS UPPER LVL RIDGING BUILDS
OVR THE REGION. HOWEVER...A MOIST SERLY FLOW WILL YIELD LINGERING
LOW CLOUDS AND SPOTTY DRIZZLE. SUPERBLEND INDICATES TEMPS ONLY
SLOWLY RISING TO BTWN 40-45F.
&&
.LONG TERM /TONIGHT THROUGH FRIDAY/...
A POTENT SOUTHERN STREAM SHORTWAVE AND ASSOC SFC LOW WILL TRACK
WEST OF PA SAT NIGHT/EARLY SUNDAY. A PERIOD OF STEADY/MODERATE
RAIN IS EXPECTED SATURDAY NIGHT INTO SUNDAY MORNING AS ANOMALOUS
SERLY LL JET/PWAT PLUME LIFTS THRU. GEFS MFLUX VALUES TOP OUT ARND
3SD ABV CLIMO EARLY SUN AM. MDL CONSENSUS RAINFALL AMOUNTS ARE
CLOSE TO 1 INCH OVER MUCH OF CENTRAL PA BY THE TIME IT TAPERS OFF
LATE SUNDAY MORNING.
ABOVE NORMAL TEMPERATURES EXPECTED SUNDAY...AS THE REGION BRIEFLY
BREAKS INTO WARM SECTOR SOUTH OF SFC LOW. HOWEVER...MUCH COLDER
AIR WILL ARRIVE VIA GUSTY WEST WINDS BEHIND THE COLD FRONT LATER
SUNDAY INTO EARLY MONDAY. A BAND OF FRONTAL RAIN SHOWERS WILL
LIKELY END AS A PERIOD OF SNOW SHOWERS OVER THE ALLEGHENIES SUNDAY
PM.
A PERSISTENT COLD WESTERLY FLOW PATTERN SHOULD SUPPORT PERIODS OF
LAKE EFFECT AND OROGRAPHIC SNOW SHOWERS THROUGH THE MIDDLE OF NEXT
WEEK. SNOW ACCUMULATION IS PROBABLE DOWNWIND OF LAKE ERIE AND OVER
THE RIDGES IN SOUTHWEST PENNSYLVANIA. TEMPERATURES SHOULD AVERAGE
BELOW NORMAL WITH SINGLE DIGITS WIND CHILLS LIKELY OVER THE
ALLEGHENIES.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS THE SYSTEM MOVES THROUGH CURRENTLY THE HEAVIEST SHOWERS ARE
MOVING INTO THE NORTHEAST...WITH LIGHT RAIN ACROSS CENTRAL PA.
TEMPERATURES HAVE INCREASED...WITH SFC TEMPS JUST ABOVE FREEZING.
DEWPOINTS REMAIN AT OR SLIGHTLY ABOVE FREEZING SO THERE STILL
REMAINS A PROBABILITY OF FREEZING RAIN OVERNIGHT. THOUGH THIS
PROBABILITY IS LESS CONSIDERING THE FLOW HAS SHIFTED TO THE
SOUTHWEST. LATEST HRRR SHOWS TEMPERATURES SLOWLY WARMING
OVERNIGHT.
HOWEVER THE COPIOUS AMOUNTS OF LOW LEVEL MOISTURE HAVE ALLOWED FOR
IFR AND LOWER CIGS TO CONTINUE THROUGH OUT THE CENTRAL AND WESTERN
TAF SITES. AS THE PRECIP MOVES LIGHTENS AND ENDS AS THE NIGHT
CONTINUES...VSBYS COULD IMPROVE...HOWEVER THE LOW STRATOCU SHOULD
REMAIN IN PLACE THROUGH THE EARLY MORNING HOURS AND SREF AND NAM
SHOWING IT SPREADING EAST. THE LOW STRATOCU WILL KEEP PERSISTENT IFR
CIGS ACROSS THE WESTERN HALF OF CENTRAL PENNSYLVANIA THROUGH THE
MORNING AND INTO THE EARLY AFTERNOON HOURS. ANY CIGS WILL LIFT
BRIEFLY IN THE SOUTHEAST TOMORROW AFTERNOON AND INTO THE EARLY
EVENING. HOWEVER. AREAS TO THE EAST...THOUGH SEEING MVFR CIGS AND
LIGHT RAIN...REMAIN ABOVE FREEZING. WINDS OUT WEST HAVE SHIFTED TO
THE SOUTH EAST...WITH CALM WINDS THROUGH CENTRAL TAF SITES...AND
EASTERLY WINDS OUT EAST. AS THE SHOWERS CONTINUE TO MOVE TO THE
NORTHEAST...EXPECT CIG AND VSBYS TO DEGRADE AT IPT AND WINDS TO
GRADUALLY SHIFT TO THE SOUTH EAST ACROSS THE REGION OVERNIGHT.
BEHIND THE FIRST SUBSTANTIAL ROUND OF FREEZING PRECIPITATION...ANY
PRECIPITATION WILL BE LIGHT. EXPECT REDUCING CIGS AND VSBYS TO
PERSIST WELL INTO TOMORROW BEFORE IMPROVING TOMORROW AFTERNOON
BRIEFLY...AND THEN DEGRADING AGAIN TOMORROW EVENING.
RESTRICTIONS WILL PERSIST THROUGH THE WEEKEND UNTIL NEXT SYSTEM
MOVES THROUGH ON SUNDAY...WHEN FLOW WILL TURN WESTERLY /AND BE
QUITE STRONG/ WITH RESTRICTIONS BECOMING CONFINED TO WESTERN
HIGHER TERRAIN.
LATE TOMORROW NIGHTS SYSTEM COULD SEE SOME LOW LEVEL WIND SHEAR
AT THE WESTERN TAF SITES AFTER 06Z SUNDAY.
OUTLOOK...
SAT...LOW CIGS CONTINUE. AREAS OF DRIZZLE POSSIBLE.
SAT NIGHT...LOW CIGS. AREAS OF RAIN. LLWS LIKELY.
SUN...AM RAIN/LOW CIGS POSSIBLE. TURNING QUITE WINDY WITH PM
SHSN/BRIEF VIS REDUCTIONS POSSIBLE KBFD/KJST. WESTERLY WIND GUSTS
ACROSS CENTRAL AND WRN PENN POSSIBLY TOPPING 40 KTS AT TIMES.
MON...A FEW LOCALIZED BANDS OF LOW CIGS AND VSBYS IN SNOW SHOWERS
ACROSS THE LAUREL HIGHLANDS AND NW MTNS. OTHERWISE...QUITE BREEZY
WITH NO WIDESPREAD SIG WX RESTRICTIONS EXPECTED.
TUE...CIG REDUCTIONS LIKELY NW HALF IN SNOW SHOWERS. VFR
ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
PAZ005-006-010>012-017>019-024>028-033>035-037-041-042-045-046-
049-050.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/GARTNER
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1209 AM EST SAT JAN 9 2016
.SYNOPSIS...
A LIGHT COATING OF FREEZING RAIN IS POSSIBLE OVER THE MOUNTAINS
TONIGHT AS WARMER AIR SPREADS ACROSS THE REGION. A STRONG LOW
PRESSURE SYSTEM WILL TAKE A PATH WEST AND NORTH OF PENNSYLVANIA
SATURDAY NIGHT INTO EARLY SUNDAY. AN UPPER LEVEL TROUGH WILL THEN
PIVOT THROUGH THE NORTHEAST CONUS DURING THE FIRST HALF OF NEXT
WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
10 PM UPDATE...
A COUPLE OF MORE WAVES OF SHOWERS /SCT COVG/ CONTINUE TO MOVE
INTO THE AREA FROM THE SW. MANY OF THE POPULATED AREAS ARE ABOVE
FREEZING. HOWEVER...THE HIGH ELEVATIONS IN THE
LAURELS...ALLEGHENIES AND NORTHEAST MOUNTAINS ARE AOB FREEZING.
WHILE IT IS STILL EXPECTED TO WARM UP A DEG OR TWO
OVERNIGHT...LATEST HRRR AND RAP SFC TEMPS REMAIN BELOW FZG IN THE
HIGHER ELEVS THRU 10Z. LWX HAS EXTENDED THEIR ADVY INTO THE
MORNING...AND HAVE WE HAVE CHOSEN TO EXTEND THE ADVY SEGMENT WHICH
COVERS THE MAJORITY OF CENTRAL PA THROUGH 10Z AS WELL. THUS...ALL
THE FZRA ADVY NOW GOES UNTIL 10Z.
PREV...
CLOUDS WILL CONTINUE TO THICKEN ACROSS THE REGION AHEAD OF A WARM
FRONT THAT WILL BRING SOME LIGHT SHOWERS AND FREEZING RAIN THIS
EVENING. TEMPERATURES ARE CURRENTLY IN THE UPPER 30S ACROSS THE
SOUTHERN PIEDMONT AND SUSQUEHANNA VALLEY. ACROSS THE CENTRAL AND
NORTHERN MOUNTAINS TEMPERATURES HAVE STRUGGLED TO RISE TODAY AND
ARE CURRENTLY IN THE UPPER 20S. THIS HAS LED TO A CONCERN FOR
FREEZING RAIN THIS EVENING...AND WE HAVE ISSUED A FREEZING RAIN
ADVISORY FOR THESE AREAS. HIGH TEMPERATURES IN THE MOUNTAINS WILL
STRUGGLE TO REACH THE FREEZING POINT AND WILL QUICKLY COOL WHEN
PRECIPITATION ARRIVES FROM EVAPORATIONAL COOLING DUE TO THE LOW
DEW POINTS FOR THESE LOCATIONS.
THE OTHER STORY TODAY HAS BEEN THE PERSISTENT FOG AND MIST OVER
THE EXTREME SOUTHERN SUSQUEHANNA VALLEY. EVERYWHERE BUT YORK HAS
LIFTED ABOVE A MILE VISIBILITY BUT THE FOG WILL REASSERT ITSELF
LATER THIS EVENING WHEN IT STARTS RAINING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH 6 PM SATURDAY/...
RAIN SHOULD BEGIN TO FALL AROUND 7 PM OVER THE LAUREL HIGHLANDS
AND NORTHWEST MOUNTAINS AND WILL SPREAD EASTWARD FROM THERE. OVER
THE MOUNTAINS THE RAIN WILL FALL AS FREEZING RAIN AND WILL ACCUMULATE
UP TO A FEW HUNDREDTHS OF AN INCH BEFORE TEMPERATURES WARM ABOVE
FREEZING. FARTHER EAST...ESPECIALLY
CLINTON...POTTER...TIOGA...LYCOMING...AND SULLIVAN
COUNTIES...TEMPERATURES MAY NOT RISE ABOVE FREEZING DURING THE
LIGHT RAIN AND ICE COULD ACCUMULATE BETWEEN A TENTH AND TWO
TENTHS.
NO SIG RAIN EXPECTED DURING SATURDAY...AS UPPER LVL RIDGING
BUILDS OVR THE REGION. HOWEVER...A MOIST SERLY FLOW WILL YIELD
LINGERING LOW CLOUDS AND SPOTTY DRIZZLE. SUPERBLEND INDICATES
TEMPS ONLY SLOWLY RISING TO BTWN 40-45F.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
A POTENT SOUTHERN STREAM SHORTWAVE AND ASSOC SFC LOW WILL TRACK
WEST OF PA SAT NIGHT/EARLY SUNDAY. A PERIOD OF STEADY/MODERATE
RAIN IS EXPECTED SATURDAY NIGHT INTO SUNDAY MORNING AS ANOMALOUS
SERLY LL JET/PWAT PLUME LIFTS THRU. GEFS MFLUX VALUES TOP OUT ARND
3SD ABV CLIMO EARLY SUN AM. MDL CONSENSUS RAINFALL AMOUNTS ARE
CLOSE TO 1 INCH OVER MUCH OF CENTRAL PA BY THE TIME IT TAPERS OFF
LATE SUNDAY MORNING.
ABOVE NORMAL TEMPERATURES EXPECTED SUNDAY...AS THE REGION BRIEFLY
BREAKS INTO WARM SECTOR SOUTH OF SFC LOW. HOWEVER...MUCH COLDER
AIR WILL ARRIVE VIA GUSTY WEST WINDS BEHIND THE COLD FRONT LATER
SUNDAY INTO EARLY MONDAY. A BAND OF FRONTAL RAIN SHOWERS WILL
LIKELY END AS A PERIOD OF SNOW SHOWERS OVER THE ALLEGHENIES SUNDAY
PM.
A PERSISTENT COLD WESTERLY FLOW PATTERN SHOULD SUPPORT PERIODS OF
LAKE EFFECT AND OROGRAPHIC SNOW SHOWERS THROUGH THE MIDDLE OF NEXT
WEEK. SNOW ACCUMULATION IS PROBABLE DOWNWIND OF LAKE ERIE AND OVER
THE RIDGES IN SOUTHWEST PENNSYLVANIA. TEMPERATURES SHOULD AVERAGE
BELOW NORMAL WITH SINGLE DIGITS WIND CHILLS LIKELY OVER THE
ALLEGHENIES.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS THE SYSTEM MOVES THROUGH CURRENTLY THE HEAVIEST SHOWERS ARE
MOVING INTO THE NORTHEAST...WITH LIGHT RAIN ACROSS CENTRAL PA.
TEMPERATURES HAVE INCREASED...WITH SFC TEMPS JUST ABOVE FREEZING.
DEWPOINTS REMAIN AT OR SLIGHTLY ABOVE FREEZING SO THERE STILL
REMAINS A PROBABILITY OF FREEZING RAIN OVERNIGHT. THOUGH THIS
PROBABILITY IS LESS CONSIDERING THE FLOW HAS SHIFTED TO THE
SOUTHWEST. LATEST HRRR SHOWS TEMPERATURES SLOWLY WARMING
OVERNIGHT.
HOWEVER THE COPIOUS AMOUNTS OF LOW LEVEL MOISTURE HAVE ALLOWED FOR
IFR AND LOWER CIGS TO CONTINUE THROUGH OUT THE CENTRAL AND WESTERN
TAF SITES. AS THE PRECIP MOVES LIGHTENS AND ENDS AS THE NIGHT
CONTINUES...VSBYS COULD IMPROVE...HOWEVER THE LOW STRATOCU SHOULD
REMAIN IN PLACE THROUGH THE EARLY MORNING HOURS AND SREF AND NAM
SHOWING IT SPREADING EAST. THE LOW STRATOCU WILL KEEP PERSISTENT IFR
CIGS ACROSS THE WESTERN HALF OF CENTRAL PENNSYLVANIA THROUGH THE
MORNING AND INTO THE EARLY AFTERNOON HOURS. ANY CIGS WILL LIFT
BRIEFLY IN THE SOUTHEAST TOMORROW AFTERNOON AND INTO THE EARLY
EVENING. HOWEVER. AREAS TO THE EAST...THOUGH SEEING MVFR CIGS AND
LIGHT RAIN...REMAIN ABOVE FREEZING. WINDS OUT WEST HAVE SHIFTED TO
THE SOUTH EAST...WITH CALM WINDS THROUGH CENTRAL TAF SITES...AND
EASTERLY WINDS OUT EAST. AS THE SHOWERS CONTINUE TO MOVE TO THE
NORTHEAST...EXPECT CIG AND VSBYS TO DEGRADE AT IPT AND WINDS TO
GRADUALLY SHIFT TO THE SOUTH EAST ACROSS THE REGION OVERNIGHT.
BEHIND THE FIRST SUBSTANTIAL ROUND OF FREEZING PRECIPITATION...ANY
PRECIPITATION WILL BE LIGHT. EXPECT REDUCING CIGS AND VSBYS TO
PERSIST WELL INTO TOMORROW BEFORE IMPROVING TOMORROW AFTERNOON
BRIEFLY...AND THEN DEGRADING AGAIN TOMORROW EVENING.
RESTRICTIONS WILL PERSIST THROUGH THE WEEKEND UNTIL NEXT SYSTEM
MOVES THROUGH ON SUNDAY...WHEN FLOW WILL TURN WESTERLY /AND BE
QUITE STRONG/ WITH RESTRICTIONS BECOMING CONFINED TO WESTERN
HIGHER TERRAIN.
LATE TOMORROW NIGHTS SYSTEM COULD SEE SOME LOW LEVEL WIND SHEAR
AT THE WESTERN TAF SITES AFTER 06Z SUNDAY.
OUTLOOK...
SAT...LOW CIGS CONTINUE. AREAS OF DRIZZLE POSSIBLE.
SAT NIGHT...LOW CIGS. AREAS OF RAIN. LLWS LIKELY.
SUN...AM RAIN/LOW CIGS POSSIBLE. TURNING QUITE WINDY WITH PM
SHSN/BRIEF VIS REDUCTIONS POSSIBLE KBFD/KJST. WESTERLY WIND GUSTS
ACROSS CENTRAL AND WRN PENN POSSIBLY TOPPING 40 KTS AT TIMES.
MON...A FEW LOCALIZED BANDS OF LOW CIGS AND VSBYS IN SNOW SHOWERS
ACROSS THE LAUREL HIGHLANDS AND NW MTNS. OTHERWISE...QUITE BREEZY
WITH NO WIDESPREAD SIG WX RESTRICTIONS EXPECTED.
TUE...CIG REDUCTIONS LIKELY NW HALF IN SNOW SHOWERS. VFR
ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 5 AM EST SATURDAY FOR PAZ005-006-
010>012-017>019-024>028-033>035-037-041-042-045-046-049-050.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/GARTNER
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1141 PM CST FRI JAN 8 2016
.AVIATION...
THE LATEST HRRR BRINGS A FEW SHOWERS ACROSS KCLL/KUTS OVERNIGHT
BUT THE DEEPER CONVECTION IS WELL EAST OF AREA TAF SITES. LOW CIGS
AND AREAS OF FOG DEVELOPING IN THE WAKE OF THE CONVECTION WILL
CONTINUE TO HAMPER AVIATION INTERESTS OVERNIGHT. NOT MUCH
CONFIDENCE IN HOW THINGS EVENTUALLY PLAY OUT AS DRIER AIR TO THE
WEST SHOULD FILTER IN TO THE REGION OVERNIGHT. THERE COULD BE SOME
BRIEF CLEARING BEFORE WRAP AROUND CLOUDS BRING MVFR CIGS BACK TO
AREA TAF SITES FOR MUCH OF SATURDAY. WINDS WILL BE CONSIDERABLY
STRONGER ON SATURDAY AND ADDED A GUST GROUP. 43
&&
.PREV DISCUSSION... /ISSUED 923 PM CST FRI JAN 8 2016/
UPDATE...
QUICK FORECAST UPDATE TO DROP THE WESTERN TWO THIRDS OF THE
FORECAST AREA FROM SEVERE THUNDERSTORM WATCH 1 AS MAJORITY OF
CONVECTION HAS EXITED THE FORECAST AREA. HAVE ALSO ISSUED A
SHORT-FUSED DENSE FOG ADVISORY FOR THE WESTERN COUNTIES AS
VISIBILITIES HAVE DROPPED TO LESS THAN ONE MILE IN MANY LOCATIONS.
MAY POSSIBLY SEE DENSE FOG DEVELOP IN AND AROUND THE HOUSTON METRO
AS WELL... AND WILL CONTINUE TO MONITOR FOR POSSIBLE EASTWARD
EXPANSION OF THE ADVISORY. WINDS SHIFTING TO THE WEST/NORTHWEST
AHEAD OF AN APPROACHING COLD FRONT TONIGHT WILL HELP DISSIPATE
THE DENSE FOG THAT DEVELOPS... BUT GIVEN UNCERTAINTY ON TIMING THE
DENSE FOG ADVISORY MAY ALSO NEED TO BE EXTENDED IN TIME.
HUFFMAN
PREV DISCUSSION... /ISSUED 311 PM CST FRI JAN 8 2016/
DISCUSSION...
STARTING TO SEE AN INCREASE OF SHRA/TSRA ALONG AND NEAR THE UPPER
TX COAST THIS AFTN AS THE WARM FRONT (OR POSSIBLY A WEAK SFC LOW)
BEGINS TO DEVELOP/MOVE INLAND. RAIN CHANCES WILL CONTINUE TO INCREASE
THIS EVENING WITH THE APPROACH AND PASSAGE OF A STRONG UPPR LEVEL
DISTURBANCE FROM THE WEST. THERE IS A POSSIBILITY OF STRONG TO
SEVERE TSRA WITH THIS FEATURE GIVEN THE VERY STEEP LAPSE RATES AND
DYNAMIC JET STRUCTURE FOR THIS EVENING. HOWEVER..LIMITED DAYTIME
HEATING ALONG WITH A VERY DRY AIRMASS OVER SE TX ARE SOME OF THE
MAIN OBSTACLES TO OVERCOME FOR THESE STORMS TO DEVELOP. SPC`S DAY
1 OUTLOOK HAS MORE DETAILS.
THE PASSAGE OF THE STORM SYSTEM/UPPER TROF THIS EVENING WILL ALSO
DRAG A STRONG COLD FRONT ACROSS SE TX OVERNIGHT AND EARLY SAT
MORNING. COLDER/CLEARING FOR THE REST OF THE WEEKEND AS WINDS
ALOFT BECOME MORE NWLY WITH TIME. HOWEVER...AS IT HAS BEEN THE
CASE MORE OFTEN THAN NOT THIS SEASON...THE RIDGING WITH WILL BE
SHORT LIVED AS WE SEE THE RETURN OF THE SUBTROPICAL JET OVER THE
STATE WITH ANOTHER UPPER TROF DIGGING INTO NRN MEXICO. AND THEN BY
MON (WITH THE SFC HIGH MOVING OFF TO THE E/NE) WE SHOULD BEGIN TO
SEE THE RETURN OF SOME LOW POPS (COASTAL WATERS/SW PARTS OF THE
AREA)...BEFORE POPS SPREAD FURTHER INLAND (LATE WEDS/THUR) AS THE
UPPER TROF MOVES IN FROM THE WEST. 41
MARINE...
PATCHY AREAS OF DENSE SEA FOG WILL REMAIN A POSSIBILITY UNTIL 1-3AM
UNTIL A PREFRONTAL TROUGH PUSHES THRU THE WATERS. AHEAD OF THIS TROF...
WILL PROBABLY SEE SOME SCT SHOWERS/STORMS DEVELOP IN THE WATERS AS
UPPER LEVEL CONDITIONS BECOME MORE FAVORABLE. MAY SEE SOME ISOLATED
STRONGER CELLS CAPABLE OF PRODUCING WATERSPOUTS AND POSSIBLY GUSTY
WINDS. THREAT DIMINISHES AFTER MIDNIGHT ONCE WE SEE A WRLY WIND SHIFT.
COLD FRONT ITSELF WILL MOVE INTO THE AREA EARLY SAT MORNING. WINDS WILL
BECOME MORE NWRLY AND INCREASE TO CAUTION AND ADVSY CRITERIA. WINDS/SEAS
BEGIN DIMINISHING SUNDAY THEN GRADUALLY VEER TO THE NE/E INTO THE MIDWEEK
TIME PERIOD. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 46 56 33 48 31 / 40 10 0 0 10
HOUSTON (IAH) 52 61 36 50 33 / 70 10 0 0 10
GALVESTON (GLS) 55 62 40 49 42 / 60 10 0 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...COLORADO...
FORT BEND...GRIMES...JACKSON...MATAGORDA...WALLER...
WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
900 AM MST SAT JAN 9 2016
.SYNOPSIS...
THE GRADUAL WARMING AND DRYING TREND WILL CONTINUE TODAY IN THE WAKE
OF THIS PAST WEEK`S RAINFALL. ANOTHER WEAK STORM SYSTEM WILL BRING A
VERY SLIGHT CHANCE OF SHOWERS TO THE AREA AGAIN TONIGHT AND SUNDAY.
NEXT WEEK WILL GENERALLY BE RAIN-FREE ACROSS THE DESERT SOUTHWEST AND
TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.DISCUSSION...
A RETURN TO DRIER AND SLIGHTLY WARMER CONDITIONS WILL CONTINUE TODAY
AS ATMOSPHERIC MOISTURE CONTINUES TO DRAW DOWN AND THE REGION BECOMES
SLIGHTLY REMOVED FROM THE UPPER STORM TRACK. SURFACE CONDITIONS THIS
MORNING ARE COOL...CALM AND SKIES ARE MOSTLY CLEAR. LINGERING
SURFACE MOISTURE AND STILL SATURATED FIELD/LANDSCAPES DID SUPPORT
SOME LIMITED MIST AND FOG DEVELOPMENT THIS MORNING. FOG/IR IMAGERY
NOT OVERLY ENTHUSIASTIC ABOUT THE COVERAGE HOWEVER SOME SOCIAL MEDIA
REPORTS AND SURFACE OBSERVATIONS AROUND THE AREA DO INDICATE SOME
MINIMAL VSBY RESTRICTIONS (SCOTTSDALE...GILA BEND AND AROUND THE
KOMATKE AREA AND GILA RIVER DRAINAGE TO BE SPECIFIC). ANY AREAS OF
PATCHY FOG/MIST DEVELOPMENT WILL SLOWLY DISSIPATE IN THE NEXT HOUR OR
TWO ONCE THE SUN GETS HIGHER IN THE SKY. DRY AND MOSTLY CLEAR
CONDITIONS IN STORE FOR TODAY AS WE SEE A BREAK IN BETWEEN THE ACTIVE
STORM SYSTEM TRAIN. NO UPDATES NEEDED TO THE FORECAST PACKAGE THIS
MORNING.
&&
.PREVIOUS DISCUSSION...
NORTHWESTERLY FLOW HAS BECOME ESTABLISHED ACROSS THE DESERT
SOUTHWEST IN THE WAKE OF THE LOW PRESSURE SYSTEM THAT BROUGHT THE
WIDESPREAD PRECIPITATION TO THE AREA. MAIN WEATHER CONCERN IN THE
SHORT-TERM IS THE POTENTIAL FOR FOG FORMATION. CROSSOVER TEMPERATURES
ARE GENERALLY IN THE UPPER 30S...SUGGESTING SOME POTENTIAL FOR
SATURATION NEAR THE SURFACE AROUND SUNRISE. HOWEVER...RECENT RUNS OF
THE HRRR ONLY INDICATE AN ISOLATED THREAT...PARTICULARLY ACROSS THE
LOWER GILA RIVER VALLEY. LATEST NCAR ENSEMBLE ALSO INDICATES VERY LOW
PROBABILITIES FOR RESTRICTED VSBYS. ANY FOG THAT DOES DEVELOP WILL
LIKELY BE PATCHY AND SHALLOW. IN TERMS OF SENSIBLE WEATHER...TODAY
WILL FINALLY BE A RAIN-FREE DAY BUT TEMPERATURES WILL REMAIN BELOW
NORMAL.
MODELS CONTINUE TO INDICATE THAT TWO WEAK VORT MAXES WILL AFFECT THE
AREA OVERNIGHT AND SUNDAY. THE FIRST SYSTEM WILL BRING AN INCREASE
IN CLOUDS AND A SLIGHT CHANCE OF SHOWERS TO SOUTHERN CA
TONIGHT...WITH THE HIGHEST POPS RELEGATED TO JTNP. THE SECOND
SYSTEM...A BIT FURTHER NORTH WILL PROVIDE SOME FORCING FOR ASCENT
SUNDAY...THOUGH ABOVE MEDIAN POPS ARE STILL ONLY AT OR BELOW 10
PERCENT FOR MUCH OF THE AREA. LOCAL HI-RES WRFS CONTINUE TO SUGGEST
THE BETTER THREAT WILL BE FURTHER TO THE NORTH AND EAST ACROSS THE
MOGOLLON RIM.
NEXT WEEK WILL BE LARGELY CHARACTERIZED BY THE PREVALENCE OF A LONG-
WAVE RIDGE ACROSS THE PACIFIC NORTHWEST AND INTERMOUNTAIN WEST. THE
PACIFIC WILL REMAIN ACTIVE WITH SEVERAL SHORT-WAVE TROUGHS IMPACTING
THE WEST. CONSIDERABLE SPREAD STILL REMAINS AMONG THE OPERATIONAL
GFS/ECMWF AND ASSOCIATED ENSEMBLE MEMBERS...HOWEVER THE GENERAL
CONSENSUS IS THAT NONE OF THESE SYSTEMS WILL BE ANOMALOUS OR
EXTREME...NOR WILL THEY HAVE AN IMPACT ON THE REGION UNTIL AT LEAST
FRIDAY OR SATURDAY. MEANWHILE...TEMPERATURES WILL LIKELY REMAIN A FEW
DEGREES BELOW NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SKIES CLEARED EARLIER OVER MUCH OF THE AREA ASIDE FROM OVER THE
HIGHER TERRAIN. LOW LEVEL MOISTURE STILL REMAINS IN PLACE AND THUS
EXPECTING DAYTIME STRATOCU TO DEVELOP SOMETIME LATE THIS
MORNING...LASTING THROUGH THE AFTERNOON. CURRENT THINKING IS CLOUDS
WITH DECKS AROUND 6K FEET SHOULD REMAIN MOSTLY SCATTERED OVER THE
DESERTS AND BROKEN OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX.
WINDS WILL REMAIN LIGHT THROUGH THE PERIOD AND MOSTLY FOLLOW TYPICAL
DIURNAL DIRECTIONS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SKIES TO REMAIN MOSTLY CLEAR ASIDE FROM SOME SCT-BKN CIRRUS LAYERS
PASSING OVER THE TERMINALS FROM TIME-TO-TIME THROUGH THE TAF PERIOD.
WINDS TO REMAIN ON THE LIGHT SIDE...8 KTS OR LESS...FAVORING A
NORTHERLY DIRECTION AT KBLH AND WESTERLY AT KIPL.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
AN OVERALL DRY BUT COOL WEEK IS IN STORE WITH SOME POTENTIAL FOR
RETURNING PRECIPITATION CHANCES BY THE END OF THE WEEK. HIGH
TEMPERATURES WILL REMAIN WELL BELOW NORMAL EACH DAY. LOW LEVEL
MOISTURE WILL REMAIN ELEVATED OVERALL WITH MINIMUM HUMIDITY VALUES
ABOVE 30 PERCENT EACH AFTERNOON. WINDS SHOULD BE LIGHT THROUGH THE
ENTIRE PERIOD.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...NOLTE
PREVIOUS DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
502 AM MST SAT JAN 9 2016
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
THE GRADUAL WARMING AND DRYING TREND WILL CONTINUE TODAY IN THE WAKE
OF THIS PAST WEEK`S RAINFALL. ANOTHER WEAK STORM SYSTEM WILL BRING A
VERY SLIGHT CHANCE OF SHOWERS TO THE AREA AGAIN TONIGHT AND SUNDAY.
NEXT WEEK WILL GENERALLY BE RAIN-FREE ACROSS THE DESERT SOUTHWEST AND
TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.DISCUSSION...
NORTHWESTERLY FLOW HAS BECOMES ESTABLISHED ACROSS THE DESERT
SOUTHWEST IN THE WAKE OF THE LOW PRESSURE SYSTEM THAT BROUGHT THE
WIDESPREAD PRECIPITATION TO THE AREA. MAIN WEATHER CONCERN IN THE
SHORT-TERM IS THE POTENTIAL FOR FOG FORMATION. CROSSOVER TEMPERATURES
ARE GENERALLY IN THE UPPER 30S...SUGGESTING SOME POTENTIAL FOR
SATURATION NEAR THE SURFACE AROUND SUNRISE. HOWEVER...RECENT RUNS OF
THE HRRR ONLY INDICATE AN ISOLATED THREAT...PARTICULARLY ACROSS THE
LOWER GILA RIVER VALLEY. LATEST NCAR ENSEMBLE ALSO INDICATES VERY LOW
PROBABILITIES FOR RESTRICTED VSBYS. ANY FOG THAT DOES DEVELOP WILL
LIKELY BE PATCHY AND SHALLOW. IN TERMS OF SENSIBLE WEATHER...TODAY
WILL FINALLY BE A RAIN-FREE DAY BUT TEMPERATURES WILL REMAIN BELOW
NORMAL.
MODELS CONTINUE TO INDICATE THAT TWO WEAK VORT MAXES WILL AFFECT THE
AREA OVERNIGHT AND SUNDAY. THE FIRST SYSTEM WILL BRING AN INCREASE
IN CLOUDS AND A SLIGHT CHANCE OF SHOWERS TO SOUTHERN CA
TONIGHT...WITH THE HIGHEST POPS RELEGATED TO JTNP. THE SECOND
SYSTEM...A BIT FURTHER NORTH WILL PROVIDE SOME FORCING FOR ASCENT
SUNDAY...THOUGH ABOVE MEDIAN POPS ARE STILL ONLY AT OR BELOW 10
PERCENT FOR MUCH OF THE AREA. LOCAL HI-RES WRFS CONTINUE TO SUGGEST
THE BETTER THREAT WILL BE FURTHER TO THE NORTH AND EAST ACROSS THE
MOGOLLON RIM.
NEXT WEEK WILL BE LARGELY CHARACTERIZED BY THE PREVALENCE OF A LONG-
WAVE RIDGE ACROSS THE PACIFIC NORTHWEST AND INTERMOUNTAIN WEST. THE
PACIFIC WILL REMAIN ACTIVE WITH SEVERAL SHORT-WAVE TROUGHS IMPACTING
THE WEST. CONSIDERABLE SPREAD STILL REMAINS AMONG THE OPERATIONAL
GFS/ECMWF AND ASSOCIATED ENSEMBLE MEMBERS...HOWEVER THE GENERAL
CONSENSUS IS THAT NONE OF THESE SYSTEMS WILL BE ANOMALOUS OR
EXTREME...NOR WILL THEY HAVE AN IMPACT ON THE REGION UNTIL AT LEAST
FRIDAY OR SATURDAY. MEANWHILE...TEMPERATURES WILL LIKELY REMAIN A FEW
DEGREES BELOW NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SKIES CLEARED EARLIER OVER MUCH OF THE AREA ASIDE FROM OVER THE
HIGHER TERRAIN. LOW LEVEL MOISTURE STILL REMAINS IN PLACE AND THUS
EXPECTING DAYTIME STRATOCU TO DEVELOP SOMETIME LATE THIS
MORNING...LASTING THROUGH THE AFTERNOON. CURRENT THINKING IS CLOUDS
WITH DECKS AROUND 6K FEET SHOULD REMAIN MOSTLY SCATTERED OVER THE
DESERTS AND BROKEN OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX.
WINDS WILL REMAIN LIGHT THROUGH THE PERIOD AND MOSTLY FOLLOW TYPICAL
DIURNAL DIRECTIONS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SKIES TO REMAIN MOSTLY CLEAR ASIDE FROM SOME SCT-BKN CIRRUS LAYERS
PASSING OVER THE TERMINALS FROM TIME-TO-TIME THROUGH THE TAF PERIOD.
WINDS TO REMAIN ON THE LIGHT SIDE...8 KTS OR LESS...FAVORING A
NORTHERLY DIRECTION AT KBLH AND WESTERLY AT KIPL.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
AN OVERALL DRY BUT COOL WEEK IS IN STORE WITH SOME POTENTIAL FOR
RETURNING PRECIPITATION CHANCES BY THE END OF THE WEEK. HIGH
TEMPERATURES WILL REMAIN WELL BELOW NORMAL EACH DAY. LOW LEVEL
MOISTURE WILL REMAIN ELEVATED OVERALL WITH MINIMUM HUMIDITY VALUES
ABOVE 30 PERCENT EACH AFTERNOON. WINDS SHOULD BE LIGHT THROUGH THE
ENTIRE PERIOD.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
327 AM MST SAT JAN 9 2016
.SYNOPSIS...
THE GRADUAL WARMING AND DRYING TREND WILL CONTINUE TODAY IN THE WAKE
OF THIS PAST WEEK`S RAINFALL. ANOTHER WEAK STORM SYSTEM WILL BRING A
VERY SLIGHT CHANCE OF SHOWERS TO THE AREA AGAIN TONIGHT AND SUNDAY.
NEXT WEEK WILL GENERALLY BE RAIN-FREE ACROSS THE DESERT SOUTHWEST AND
TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.DISCUSSION...
NORTHWESTERLY FLOW HAS BECOMES ESTABLISHED ACROSS THE DESERT
SOUTHWEST IN THE WAKE OF THE LOW PRESSURE SYSTEM THAT BROUGHT THE
WIDESPREAD PRECIPITATION TO THE AREA. MAIN WEATHER CONCERN IN THE
SHORT-TERM IS THE POTENTIAL FOR FOG FORMATION. CROSSOVER TEMPERATURES
ARE GENERALLY IN THE UPPER 30S...SUGGESTING SOME POTENTIAL FOR
SATURATION NEAR THE SURFACE AROUND SUNRISE. HOWEVER...RECENT RUNS OF
THE HRRR ONLY INDICATE AN ISOLATED THREAT...PARTICULARLY ACROSS THE
LOWER GILA RIVER VALLEY. LATEST NCAR ENSEMBLE ALSO INDICATES VERY LOW
PROBABILITIES FOR RESTRICTED VSBYS. ANY FOG THAT DOES DEVELOP WILL
LIKELY BE PATCHY AND SHALLOW. IN TERMS OF SENSIBLE WEATHER...TODAY
WILL FINALLY BE A RAIN-FREE DAY BUT TEMPERATURES WILL REMAIN BELOW
NORMAL.
MODELS CONTINUE TO INDICATE THAT TWO WEAK VORT MAXES WILL AFFECT THE
AREA OVERNIGHT AND SUNDAY. THE FIRST SYSTEM WILL BRING AN INCREASE
IN CLOUDS AND A SLIGHT CHANCE OF SHOWERS TO SOUTHERN CA
TONIGHT...WITH THE HIGHEST POPS RELEGATED TO JTNP. THE SECOND
SYSTEM...A BIT FURTHER NORTH WILL PROVIDE SOME FORCING FOR ASCENT
SUNDAY...THOUGH ABOVE MEDIAN POPS ARE STILL ONLY AT OR BELOW 10
PERCENT FOR MUCH OF THE AREA. LOCAL HI-RES WRFS CONTINUE TO SUGGEST
THE BETTER THREAT WILL BE FURTHER TO THE NORTH AND EAST ACROSS THE
MOGOLLON RIM.
NEXT WEEK WILL BE LARGELY CHARACTERIZED BY THE PREVALENCE OF A LONG-
WAVE RIDGE ACROSS THE PACIFIC NORTHWEST AND INTERMOUNTAIN WEST. THE
PACIFIC WILL REMAIN ACTIVE WITH SEVERAL SHORT-WAVE TROUGHS IMPACTING
THE WEST. CONSIDERABLE SPREAD STILL REMAINS AMONG THE OPERATIONAL
GFS/ECMWF AND ASSOCIATED ENSEMBLE MEMBERS...HOWEVER THE GENERAL
CONSENSUS IS THAT NONE OF THESE SYSTEMS WILL BE ANOMALOUS OR
EXTREME...NOR WILL THEY HAVE AN IMPACT ON THE REGION UNTIL AT LEAST
FRIDAY OR SATURDAY. MEANWHILE...TEMPERATURES WILL LIKELY REMAIN A FEW
DEGREES BELOW NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... L
CONSIDERABLE LOW/MID CLOUD PERSISTING ACROSS THE GREATER PHOENIX
AREA THIS EVENING...WITH CIGS DOWN AS LOW AS 4-5K FEET IN PLACES AND
WIDESPREAD CIGS 8-10K FEET. EXPECT THAT CIGS WILL START TO SCATTER
OUT LATER THIS EVENING AS SOMEWHAT DRIER AIR STARTS TO WORK IN FROM
THE NORTHWEST. STILL...LATEST HI-RES GUIDANCE SUGGESTS SHOWERS IN
THE AREA THRU 06Z...AND FORECAST SOUNDINGS KEEP RATHER SATURATED
LAYERS AROUND 5K FEET INTO THE MORNING ON SATURDAY. WILL ATTEMPT TO
SCATTER OUT THE LOWEST DECKS AFTER 06Z IN THE PHOENIX TAFS BUT
REALIZE THAT A STRAY CIG BELOW 6K FEET IS POSSIBLE PAST 12Z SAT.
SOME HIGH CLOUDS SHOULD BE MOVING INTO THE AREA FROM THE WEST LATER
TONIGHT AND INTO THE DAY SATURDAY AS WELL.
AS FAR AS THE POTENTIAL FOR FOG ON SAT MORNING IS CONCERNED...IT
APPEARS THAT FOG DEVELOPMENT IS UNLIKELY DUE TO THE FACT IT APPEARS
THAT ENOUGH DRY AIR WILL BE MIXING DOWN TO THE SFC TO PREVENT FOG
FORMATION...ALONG WITH THE FACT THAT INCREASING HIGH CLOUDINESS
SHOULD INHIBIT NIGHTTIME COOLING OF THE LOWER LEVELS OF THE
ATMOSPHERE. WINDS WILL BE REMAINING ON THE LIGHT SIDE...MAINLY 8 KTS
OR LESS...AND FAVOR USUAL DIURNAL TRENDS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SKIES TO REMAIN MOSTLY CLEAR ASIDE FROM SOME SCT-BKN CIRRUS LAYERS
PASSING OVER THE TERMINALS FROM TIME-TO-TIME THROUGH THE TAF PERIOD.
WINDS TO REMAIN ON THE LIGHT SIDE...8 KTS OR LESS...FAVORING A
NORTHERLY DIRECTION AT KBLH AND WESTERLY AT KIPL.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A FAST MOVING WEATHER SYSTEM WILL BRING A CHANCE OF SHOWERS MAINLY
SATURDAY NIGHT INTO SUNDAY AS A WEAK DISTURBANCE PASSES THROUGH THE
REGION. COOL TEMPERATURES WILL PREVAIL WITH SOME GRADUAL WARMING
GOING INTO NEXT WEEK...BUT HIGHS WILL REMAIN BELOW NORMAL. HIGH
PRESSURE WILL SETTLE IN EARLY NEXT WEEK ALLOWING FOR GRADUAL DRYING
CONDITIONS. HUMIDITY WILL BE MUCH ABOVE AVERAGE WITH MINIMUM VALUES
NEAR 50 PERCENT INTO MONDAY WITH VALUES FALLING INTO THE 30S BY
WEDNESDAY. WINDS SHOULD BE LIGHT THROUGH THE ENTIRE PERIOD.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION...PERCHA/CB
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
413 AM MST SAT JAN 9 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM MST SAT JAN 9 2016
CURRENTLY...
GENERALLY CLOUDY SKIES WITH AREAS OF FOG PREVAIL ACROSS THE FCST
AREA. A FEW SNOW SHOWERS WERE STILL NOTED OVER THE PLAINS...AND SNOW
SHOWERS WERE OCCURRING ACROSS THE CENTRAL MTNS. TEMPS WERE STILL
REASONABLY MILD OVER THE REGION GIVEN THE CLOUD COVER...WITH TEENS
AND 20S OVER THE PLAINS...TEENS AND SINGLE DIGITS VALLEYS...AND
SINGLE DIGITS MTNS.
TODAY...
A COLD DAY IS EXPECTED ACROSS THE REGION. WE SHOULD SEE CLOUDS
DECREASE SOMEWHAT OVER THE AREA BUT WE WILL STILL SEE QUITE A BIT OF
CLOUDS THIS AFTERNOON OVER MOST OF THE REGION AS INDICATED BY POINT
SOUNDINGS. SNOW SHOWERS WILL CONTINUE ON THE CENTRAL MTNS...WITH
LIGHT ACCUMS POSSIBLE. GIVEN THE SNOW THAT FELL OVER THE PLAINS AND
CLOUD COVER...TEMPS WILL STRUGGLE TO REACH THE FREEZING MARK OVER
THE LOWER ELEVATIONS THIS AFTERNOON.
TONIGHT...
COLD. SAN LUIS VALLEY WILL LIKELY WILL BE COLDEST WITH MIN TEMPS
EXPECTED IN THE NEGATIVE SINGLE DIGITS . OVER THE PLAINS POSITIVE
SINGLE DIGITS ARE LIKELY. MTNS WILL RANGE FROM ZERO TO NEGATIVE 10F.
IT WILL REMAIN DRY. SOUNDINGS SHOW THE LOW LVLS DRYING OUT OVER THE
PLAINS DURING THE EARLY MORNING HOURS...AND THIS MAY LIMIT FOG
POTENTIAL...ALTHOUGH I CANNOT RULE IT OUT COMPLETELY. SOUNDING
PROFILES INDICATE THE SAN LUIS VALLEY MAY CLOUD UP/FOG UP LATER
TONIGHT AND HAVE ACCOUNTED FOR THIS IN THE NDFD.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 356 AM MST SAT JAN 9 2016
NOT MUCH CHANGE TO THE FORECAST THINKING THROUGH MUCH OF THE
EXTENDED PERIOD. THERE IS SOME UNCERTAINTY LATE IN THE WORK WEEK
WITH AN INCOMING UPPER DISTURBANCE BETWEEN THE GFS AND ECMWF WITH
HIGHER ENSEMBLE SPREADS.
SUNDAY...AN UPPER DISTURBANCE IN NORTHWEST FLOW WILL TRACK SOUTH
ACROSS WESTERN COLORADO. THIS WILL BRING PERIODS OF LIGHT SNOW TO
THE CONTINENTAL DIVIDE THROUGH SUNDAY EVENING BEFORE COMING TO AN
END DURING THE OVERNIGHT HOURS. AN INCH OR TWO OF ACCUMULATION IS
POSSIBLE...ESPECIALLY ON NORTHWEST FACING SLOPES. COLD AND DRY
CONDITIONS WILL PREVAIL ACROSS THE PLAINS WITH HIGHS IN THE 30S.
MONDAY THROUGH WEDNESDAY...NORTHWEST FLOW WILL GIVE WAY TO HIGH
PRESSURE ALOFT MOVING ACROSS COLORADO. EXPECT DRY CONDITIONS
ACROSS THE REGION THROUGH THIS PERIOD. TEMPERATURES WILL SLOWLY
WARM WITH MID TO UPPER 40S FOR THE PLAINS BY WEDNESDAY.
THURSDAY AND FRIDAY...MODELS DIVERGE HEADING INTO THE LATE WORK
WEEK. THE GFS SHIFTS THE UPPER RIDGE EAST INTO THE CENTRAL PLAINS
AND BRINGS A STRONG TROUGH ACROSS THE DESERT SOUTHWEST. PLENTY OF
MOISTURE AND SOUTHWEST FLOW ON THURSDAY WOULD SPREAD SNOW INTO THE
CONTINENTAL DIVIDE...THEN SPREADING EAST ACROSS THE PLAINS BY
FRIDAY BEHIND A COLD FRONT. DECENT MOUNTAIN SNOWS WOULD BE
POSSIBLE WITH LIGHT SNOWS ACROSS THE PLAINS BASED ON THE GFS
SOLUTION. THE ECMWF IS MUCH SLOWER AND FURTHER SOUTH WITH THE
STORM SYSTEM. IT DOES NOT BRING THE SYSTEM ACROSS THE AREA UNTIL
FRIDAY INTO THE WEEKEND...WITH THE STORM TRACK NEAR THE MEXICO
BORDER. THIS WOULD KEEP MOST OF THE PRECIPITATION TO THE SOUTH
WITH LIMITED COVERAGE ACROSS SOUTHERN COLORADO. ENSEMBLE SPREADS
ARE HIGH...SO CONFIDENCE IN STORM TRACK AND PRECIPITATION ARE LOW
AT THIS TIME FOR THURSDAY AND FRIDAY. MOZLEY
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 356 AM MST SAT JAN 9 2016
KCOS...LIFR CONDITIONS NOTED AT KCOS AT 11 UTC THIS MORNING AS
DENSE FOG WAS OVER THE AIRPORT. THESE CONDITIONS WILL LIKELY EXIST
UNTIL MID MORNING...ALTHOUGH IFR/MVFR MAY EXIST THROUGH MOST IF
NOT ALL OF THE DAY. IT SHOULD REMAIN DRY. CONDITIONS ARE FCST TO
DRY OUT THIS EVENING WITH VFR CONDITIONS RETURNING. PLAN TO
CLOSELY MONITOR HRRR DATA FOR THE 12 UTC TAF FCST.
KPUB...MVFR CIGS NOTED AT 11 UTC. EXPECT CIGS AND VIS TO COME
DOWN SOMEWHAT THIS MORNING. LOWER CLOUDS WILL LIKELY REMAIN OVER
THE TAF SITE INTO THE AFTERNOON BUT MAY CIGS WILL PROBABLY BE
ABOVE MVFR CRITERIA. CONDITIONS SHOULD DRY OUT LATER TONIGHT WITH
VFR CONDITIONS RETURNING.
KALS...MID CLOUD DECK KEEPING VIS ABOVE P6SM AND PREVENTING FOG
FORMATION. DO NOT KNOW IF THIS WILL LAST THROUGH THE MORNING AS IF
IT CLEARS OUT ANY FOG WILL FORM AND CIGS WILL LOWER. HI RES
GUIDANCE INDICATES LOW CIGS/FOG SHOULD DEVELOP OVER KALS THIS
MORNING. WILL CONTINUE TO MONITOR. FOR TONIGHT...LOW CLOUDS
EXPECTED FOR THE SAN LUIS VALLEY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...MOZLEY
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1047 AM EST SAT JAN 9 2016
.SYNOPSIS...
HIGH PRESSURE FROM EASTERN CANADA DOWN TO THE MID ATLANTIC STATES
WEAKENS LATE TODAY. LOW PRESSURE IN THE OHIO VALLEY THIS EVENING
INTENSIFIES RAPIDLY IS IT CROSSES PENNSYLVANIA AND NEW YORK STATE
SUNDAY. IT DRAWS A STRONG WARM FRONT NORTHWARD THROUGH OUR AREA
SUNDAY MORNING, THEN A STRONG COLD FRONT PASSES OFF THE COAST
SUNDAY AFTERNOON. HIGH PRESSURE BUILDS TO OUR SOUTH LATE MONDAY.
GREAT LAKES LOW PRESSURE TUESDAY SENDS A STRONG COLD FRONT ACROSS
THE MID ATLANTIC STATES TUESDAY EVENING. THAT LOW REFORMS ALONG
COASTAL NEW ENGLAND AND INTENSIFIES RAPIDLY ON WEDNESDAY. HIGH
PRESSURE BUILDS TO OUR SOUTH ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLIER THIS MORNING, THE WINTER WEATHER ADVISORY WAS ALLOWED TO
EXPIRE AS PRECIP WAS LIMITED OVER THE REMAINING ADVISORY AREA AND
TEMPERATURES WERE ABOVE FREEZING, EXCEPT ACROSS THE HIGHEST
TERRAIN LOCATIONS. AN UPWARD TREND HAS CONTINUED WITH HOURLY
TEMPERATURES SINCE THAT TIME, AND TEMPS ARE GENERALLY RUNNING IN
THE MID TO UPPER 30S WITH A LITTLE LIGHT RAIN/DRIZZLE ACROSS
NORTHWEST NJ AND THE POCONOS. IN FACT, WE ACTUALLY EXTENDED THE
COVERAGE AND LOW POPS FOR LIGHT RAIN ACROSS MUCH OF NJ THROUGH
THE REMAINDER OF THE MORNING TO EARLY AFTERNOON, BASED ON LATEST
RADAR TRENDS. OTHERWISE, SOME MINOR ADJUSTMENTS WERE MADE TO
HOURLY TEMPS THROUGH THE REST OF THE MORNING FOR THE REMAINDER OF
THE CWA, WITH TEMPS RISING INTO THE MID/UPPER 40S AND EVEN SOME
50S ACROSS SOUTHERN NJ AND THE SOUTHERN DELMARVA.
OTHERWISE, TODAY LOOKS TO BE A CLOUDY DAY ACROSS THE REGION AS A
WARM FRONTAL BOUNDARY LIFTS NORTHWARD INTO NEW ENGLAND AND LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST UNITED STATES COASTLINE. THIS
WILL RESULT IN WARMER AND MOISTER AIR BEING ADVECTED INTO THE
REGION WITH EASTERLY WINDS FROM 5-10 MPH. DAYTIME TEMPERATURES
SHOULD RISE TO AROUND 50 FOR MOST LOCATIONS WITH THE POCONOS
STRUGGLING TO GET OUT OF THE UPPER 30S. BOTH THE HRRR AND RAP
MESOSCALE MODELS ARE TRYING TO SPIT OUT A BRIEF SHOWER OR TWO
TODAY, SO HAVE LOW OR SLIGHT CHANCE POPS ACROSS THE REGION TODAY.
THE MAJORITY OF THE REGION WILL STAY DRY THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE LOW PRESSURE IN THE SOUTHEAST UNITED STATES WILL CONTINUE TO
MOVE QUICKLY NORTHWARD TONIGHT REACHING OUR AREA BY SUNDAY MORNING
WITH A WARM FRONT EXTENDING EAST OF THE LOW PRESSURE CENTER. AN
AGGRESSIVE LLJ MODELED NEAR 60 KNOTS WILL CONTINUE TO SEND NORTHWARD
WARMER AND MOIST AIR INTO THE REGION. MOISTURE LIFTING OVER THE WARM
FRONT WILL LEAD TO WIDESPREAD RAIN BREAKING OUT TO OUR SOUTH LATE
SATURDAY. THE RAIN WILL INCREASE IN COVERAGE AND INTENSITY AS THE
NIGHT GOES ON WITH ALL LOCATIONS SEEING A STEADY RAIN BY SUNDAY
MORNING. TEMPERATURES WILL ACTUALLY RISE OVERNIGHT AND THE FORECAST
DOES GO WARMER WITH THE TEMPERATURES OVERNIGHT THAN WHAT THE MAV/MET
GUIDANCE SUGGESTS DUE TO THE LLJ INFLUENCE. AROUND HALF AN INCH OF
RAIN SHOULD FALL TONIGHT WITH ADDITIONAL RAIN ON SUNDAY. SOME OF THE
HEAVIER INTERVALS OF RAIN MAY CAUSE SOME PONDING OF WATER ON
ROADWAYS.
WINDS WILL INCREASE AS WELL, THE GFS, ECMWF AND NAM ALL
SUGGEST WINDS AT 925 MB REACH AT LEAST 50 MPH BY SUNDAY MORNING SE
OF PHILADELPHIA. WHILE THE STRONGEST WINDS WILL LIKELY BE ON SUNDAY,
THE FORECAST DOES GO STRONGER THAN GUIDANCE WITH THE WINDS AFTER
MIDNIGHT TONIGHT. SOME EAST TO SOUTHEAST WIND GUSTS AROUND 25 MPH
ARE POSSIBLE BY SUNDAY MORNING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
500 MB: A NEGATIVE TILT SHORT WAVE RIPS NEWD THROUGH THE NORTHEAST
SUNDAY FOLLOWED BY THE DEVELOPMENT OF A FULL LATITUDE TROUGH ALONG
THE EAST COAST NEXT TUESDAY AND THEN WESTERLY FLOW DEVELOPS BY NEXT
THURSDAY BEFORE A NEW TROUGH FORMS IN THE CENTRAL USA NEXT WEEKEND.
TEMPERATURES: AFTER RECORD OR NEAR RECORD WARMTH SUNDAY AND MAXIMUM
TEMPERATURES NEARLY 25 DEGREES ABOVE NORMAL, CALENDAR DAY AVERAGES
WILL COOL TO NEAR NORMAL MONDAY AND TUESDAY, THEN SLIP A FEW DEGREES
BELOW NORMAL WEDNESDAY. THEREAFTER THERE IS SOME UNCERTAINTY...
BUT OVERALL NEAR OR SLIGHTLY BELOW NORMAL THURSDAY AND FRIDAY.
FORECAST BASIS: UNLESS OTHERWISE NOTED, A 50 50 BLEND 00Z/9 GFS/NAM
MOS GUIDANCE SUNDAY-SUNDAY NIGHT, THEREAFTER THE 00Z/9 GFS MEX MOS
MONDAY AND TUESDAY, THEN FOR TUESDAY NIGHT-FRIDAY GENERALLY THE
06Z/9 SUPERBLEND WHICH INCLUDES 00Z/9 GFS MEX GUIDANCE AND WPC
GUIDANCE.
THE DAILIES...
SUNDAY...A STORMY MORNING WITH AN OPPORTUNITY FOR A STRONG TSTM
IN STRONG SE INFLOW WITH INSTABILITY, ESPECIALLY ALOFT WHERE SWI
WILL BE BRIEFLY NEAR -2C, TT IN THE LOWER 50S AND RAPIDLY FALLING
SFC PRES. THIS COULD MEAN ISOLATED WIND GUSTS 40-50 MPH, ESPECIALLY
DELMARVA AND COASTAL NJ.
WE MAY EVENTUALLY NEED A WIND ADVY FOR THE NEAREST 5 MILES OF THE NJ
COAST IN THE 10Z-15Z TIME FRAME AND THIS IS WHERE I`VE GREATEST
CONFIDENCE ON VERIFYING NON CONVECTIVE 46 MPH SE WIND GUSTS.
BRIEF POOR DRAINAGE STREET FLOODING IN THE MORNING BUT OTRW NO
STREAM FLOODING EXPECTED.
TIDES WILL APPROACH MINOR ADVISORY STAGE IN THE 12Z-14Z TIME FRAME
BUT NO ADVISORY ATTM.
A WSHIFT TO WSW IN THE AFTERNOON WITH RECORD OR NEAR RECORD WARMTH
DURING MIDDAY BEGINNING TO BE SWEPT SEAWARD AND MAYBE ONE LAST
BAND OF SHOWERS PASSING EASTWARD AS A COLD FRONT MOVES THROUGH OUR
FORECAST AREA.
SUNDAY NIGHT...P/C, WINDY AND TURNING COLDER. GUSTY WEST WINDS 30-40
MPH. STRONG PRESSURE RISES DURING THE EVENING ACCOMPANIES THE INFLUX
OF COLDER DRIER AIR. SMALL CHC OF FLURRIES IN THE POCONOS.
MONDAY...DRY AND BREEZY. WESTERLY WIND GUSTS TO 25 MPH. .
TUESDAY...CHANCE OF SNOW SHOWERS OR FLURRIES IN THE DESTABILIZING
AIRMASS AS A STRONG TROUGH DEVELOPS ALONG THE EAST COAST. GUSTY
SOUTHWEST WINDS 20 TO 25 MPH SHIFTING TO WEST AT NIGHT WITH GUSTS
20 TO 30 MPH.
WEDNESDAY...WINDY AND COLD. DRY WITH EXCEPTION ALONG AND NORTH OF
I-78 WHERE THERE ARE MODEL INDICATIONS OF STEEP LAPSE RATES AND
POSSIBLE FLURRIES. WESTERLY WINDS WILL BE GUSTING 30 TO POSSIBLY
40 MPH.
THURSDAY...DIMINISHING WIND AND NOT QUITE AS COLD.
FRIDAY...UNCERTAINTY. FOR NOW, FORECASTING QUIET WEATHER (NOT THE
OUTLIER 00Z/9 ECMWF OPERATIONAL SOLUTION)
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
MOST LOCATIONS ARE CURRENTLY VARYING BETWEEN MVFR AND VFR
CEILINGS, WITH KRDG AND KABE MAINLY SEEING MVFR TO IFR CEILINGS.
THIS WILL LIKELY CONTINUE UNTIL ABOUT 17Z TO 18Z. LOCATIONS FROM
KPHL TO THE SOUTH AND EAST HAVE THE BEST CHANCE TO STAY VFR THE
LONGEST TODAY. THE GENERAL EXPECTATION WILL BE FOR CEILINGS TO
LOWER TO IFR LATE-DAY TO EARLY EVENING AT ALL TAF SITES. HOWEVER,
CONFIDENCE IS ONLY MEDIUM AT THIS POINT THROUGH 23Z SATURDAY ON
CEILINGS, SINCE THE CEILINGS HAVE BEEN HIGHER THAN SUGGESTED FROM
SOME OUR FORECASTING TOOLS. VISIBILITIES WILL RANGE FROM MVFR TO
VFR ACROSS THE REGION, BUT SOME IFR VSBYS ARE POSSIBLE AT TIMES,
ESPECIALLY FOR KRDG AND KABE. A GENERAL EASTERLY WIND UNDER 10
KNOTS IS EXPECTED.
MUCH HIGHER CONFIDENCE TONIGHT FOR IFR CEILINGS WITH LOWERING
VISIBILITIES AND RAIN DEVELOPING BY 06Z SUNDAY FROM SOUTH TO
NORTH. IFR OR LOWER CEILINGS AND VISIBILITIES FROM 09Z INTO
SUNDAY MORNING WITH RAIN. WINDS WILL ALSO INCREASE AND BECOME MORE
SOUTHEASTERLY TOWARD SUNDAY MORNING AROUND 15 KNOTS WITH HIGHER
GUSTS TO 25 KNOTS. LLWS POSSIBLE FROM KPHL TO THE SOUTHEAST
TOWARD KACY AFTER 09Z SUNDAY. MODERATE CONFIDENCE IN LLWS.
OUTLOOK...
SUNDAY MORNING...EARLY IFR CONDITIONS IN SHOWERY-BRIEFLY HEAVY
RAINS. POSSIBLE ISOLATED TSTM. SE WINDS GUSTY 20-25 KT EXCEPT
POSSIBLY 40-45 KT IN A TSTM. LLWS VCNTY KMIV AND KACY.
SUNDAY AFTERNOON...BECOMING VFR CIGS AOA 3500 FT WITH A POSSIBLE
RESIDUAL BAND OF SHOWERS ACCOMPANY THE COLD FRONT. WINDS SHIFTING
SOUTHWEST THEN WEST AND GUSTY 25-35 KT.
SUNDAY NIGHT-MONDAY...MOSTLY VFR. GUSTY WEST-NORTHWEST WINDS
25-30 KT.
MONDAY NIGHT...VFR.
TUESDAY-WEDNESDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS BETWEEN 20
AND 25 KT TUESDAY, BECOMING WEST-NORTHWEST TUESDAY NIGHT INTO
WEDNESDAY. GUSTS INCREASING TO 30 TO 35 KT WEDNESDAY.
&&
.MARINE...
CURRENTLY, WAVE HEIGHTS ARE FIVE TO SEVEN FEET ON THE OCEAN
WATERS AND WILL CONTINUE TO BUILD SLOWLY INTO TONIGHT. WINDS WILL
REMAIN OUT OF THE EAST UNDER SCA CRITERIA TODAY BUT WILL RAMP UP
AFTER MIDNIGHT TONIGHT, REACHING 30 KNOTS TOWARD SUNRISE SUNDAY.
STRONGER WINDS A FEW THOUSAND FEET UP IN THE ATMOSPHERE MAY MIX
DOWN LEADING TO EVEN LOCALLY HIGHER WIND GUSTS TOWARD SUNRISE
SUNDAY.
ATLC COAST: SINCE ADVISORY SEAS ARE IN PROGRESS, WE CONTINUED THE
SCA HEADLINE INTO TONIGHT BUT THE SCA WILL PROBABLY BE DISCONTINUED
AT 330 PM FOR ONE PRIMARY HEADLINE AS GALE WARNING WINDS DRAW
CLOSER TO TIME ZERO.
DE BAY: SCA CANCELLED SINCE THE PREDOMINANT INTERMITTENT GALE ON
SUNDAY SUPERSEDES THE BRIEF TRANSITION FROM NON ADVISORY TO GALE
WARNING LATE TONIGHT.
OUTLOOK...
SEA SURFACE TEMPERATURES REMAIN VERY WARM FOR JANUARY...NEAR 50F
WHICH IS ABOUT 8 DEGREES ABOVE NORMAL. THIS CONTRIBUTES TO GREATER
INSTABILITY IN WESTERLY TO NORTHERLY FLOW COLD AIR PATTERNS AND
POSSIBLY STRONGER THAN MODELED WINDS. THIS COULD WELL AGAIN BE A
FACTOR IN STRONG COLD AIR ADVECTION WIND TRANSFER SUNDAY NIGHT.
SUNDAY-SUNDAY NIGHT...GALE WARNING ISSUED, FIRST FOR 1-3 HOURS SE
INFLOW GUSTS NEAR 35KT DURING THE MORNING. WE MAY NEED A SPECIAL
MARINE WARNING FOR ISOLATED TSTM GUSTS 40-45 KT. THEN A 9 TO 12
HOUR PERIOD OF WESTERLY GALES IS ANTICIPATED FOR LATE SUNDAY OR
MORE LIKELY SUNDAY NIGHT.
MONDAY-TUESDAY...OTHER THAN A BRIEF BREAK LATE MONDAY NIGHT INTO
EARLY TUESDAY, WINDS AND SEAS LIKELY TO REMAIN ABOVE SMALL CRAFT
CRITERIA THROUGH TUESDAY.
WEDNESDAY...THERE IS A HIGH PROBABILITY FOR GALE FORCE NORTHWEST
WIND GUSTS OF 35-40 KT.
&&
.TIDES/COASTAL FLOODING...
WITH THE NEW MOON TODAY AND AN INCREASING FLOW EASTERLY FLOW,
TIDES COULD APPROACH THE MINOR COASTAL FLOOD THRESHOLD, ESPECIALLY
SUNDAY. CURRENTLY THE TIDE WITH THE HIGHEST FORECAST IS SUNDAY
MORNING, BUT EVEN THIS MORNING IT WILL BE WITHIN AN INCH OR 2 OF
FLOOD ALONG THE ATLANTIC COAST.
FOR NOW ITS A MARGINAL CHANCE OF MINOR COASTAL FLOODING AND NO
ADVISORY IS BEING ISSUED ATTM.
ALSO, BEHIND THE STORM SYSTEM, STRONG NORTHWEST WINDS WILL DEVELOP.
CURRENT ETSS FORECASTS IN INDICATING THE POSSIBILITY OF APPROACHING
BLOW OUT FOR SOME AREAS, ESPECIALLY THE DELAWARE BAY AND POSSIBLY
THE TIDAL DELAWARE RIVER.
&&
.CLIMATE...
OUR 330 AM FORECAST HAS RECORD HIGHS FORECAST SUNDAY AT SEVERAL
LOCATIONS, INCLUDING KPHL, KTTN AND KRDG, WITH RECORD EQUALING OR
JUST A DEGREE SHY OF RECORD AT KACY, KILG, KABE, KGED.
DAILY RECORD HIGHS FOR SUNDAY JAN 10 ARE LISTED BELOW:
LOCATION RECORD YEAR
------------------------------
ATLANTIC CITY 63 1930
PHILADELPHIA 63 1950
WILMINGTON 64 1930
ALLENTOWN 60 1924
TRENTON 62 1950
GEORGETOWN 67 1950
READING 58 1939
MOUNT POCONO 57 1998
WE`LL BRING THE SNOW CLIMATOLOGY BACK EARLY NEXT WEEK ONCE WE GET
THROUGH THE SUNDAY WARM EVENT AND HAVE A BETTER FEEL FOR A COUPLE
OF SNOW THREATS NEXT WEEK.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR ANZ450>455.
GALE WARNING FROM 5 AM SUNDAY TO 6 AM EST MONDAY FOR ANZ430-
431-450>455.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GAINES/KLINE
SHORT TERM...GAINES
LONG TERM...DRAG
AVIATION...DRAG/GAINES/KLINE
MARINE...DRAG/GAINES/KLINE
TIDES/COASTAL FLOODING...DRAG
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
649 AM EST SAT JAN 9 2016
.SYNOPSIS...
HIGH PRESSURE FROM EASTERN CANADA DOWN TO THE MID ATLANTIC STATES
WEAKENS LATE TODAY. LOW PRESSURE IN THE OHIO VALLEY THIS EVENING
INTENSIFIES RAPIDLY IS IT CROSSES PENNSYLVANIA AND NEW YORK STATE
SUNDAY. IT DRAWS A STRONG WARM FRONT NORTHWARD THROUGH OUR AREA
SUNDAY MORNING, THEN A STRONG COLD FRONT PASSES OFF THE COAST
SUNDAY AFTERNOON. HIGH PRESSURE BUILDS TO OUR SOUTH LATE MONDAY.
GREAT LAKES LOW PRESSURE TUESDAY SENDS A STRONG COLD FRONT ACROSS
THE MID ATLANTIC STATES TUESDAY EVENING. THAT LOW REFORMS ALONG
COASTAL NEW ENGLAND AND INTENSIFIES RAPIDLY ON WEDNESDAY. HIGH
PRESSURE BUILDS TO OUR SOUTH ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR MONROE, PA AND
SUSSEX, NJ UNTIL 9 AM. TEMPERATURES ARE ABOVE FREEZING WITH THE
EXCEPTION OF SOME LOCATIONS IN MONROE AND SUSSEX COUNTIES. A FEW
SPOTTY SHOWERS OF FREEZING RAIN HAVE OCCURRED OVER THE PAST
COUPLE OF HOURS AND MAY CONTINUE TO DO SO FOR THE NEXT FEW HOURS.
OTHERWISE, TODAY LOOKS TO BE A CLOUDY DAY ACROSS THE REGION AS A
WARM FRONTAL BOUNDARY LIFTS NORTHWARD INTO NEW ENGLAND AND LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST UNTIED STATES COASTLINE. THIS
WILL RESULT IN WARMER AND MOISTER BEING ADVECTED INTO THE REGION
WITH EASTERLY WINDS FROM 5-10 MPH. DAYTIME TEMPERATURES SHOULD RISE
TO AROUND 50 FOR MOST LOCATIONS WITH THE POCONOS STRUGGLING TO GET
OUT OF THE UPPER 30`S. BOTH THE HRRR AND RAP MESOSCALE MODELS ARE
TRYING TO SPIT OUT A BRIEF SHOWER OR TWO TODAY, SO HAVE LOW OR
SLIGHT CHANCE POPS ACROSS THE REGION TODAY. THE MAJORITY OF THE
REGION WILL STAY DRY THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE LOW PRESSURE IN THE SOUTHEAST UNITED STATES WILL CONTINUE TO
MOVE QUICKLY NORTHWARD TONIGHT REACHING OUR AREA BY SUNDAY MORNING
WITH A WARM FRONT EXTENDING EAST OF THE LOW PRESSURE CENTER. AN
AGGRESSIVE LLJ MODELED NEAR 60 KNOTS WILL CONTINUE TO SEND NORTHWARD
WARMER AND MOIST AIR INTO THE REGION. MOISTURE LIFTING OVER THE WARM
FRONT WILL LEAD TO WIDESPREAD RAIN BREAKING OUT TO OUR SOUTH LATE
SATURDAY. THE RAIN WILL INCREASE IN COVERAGE AND INTENSITY AS THE
NIGHT GOES ON WITH ALL LOCATIONS SEEING A STEADY RAIN BY SUNDAY
MORNING. TEMPERATURES WILL ACTUALLY RISE OVERNIGHT AND THE FORECAST
DOES GO WARMER WITH THE TEMPERATURES OVERNIGHT THAN WHAT THE MAV/MET
GUIDANCE SUGGESTS DUE TO THE LLJ INFLUENCE. AROUND HALF AN INCH OF
RAIN SHOULD FALL TONIGHT WITH ADDITIONAL RAIN ON SUNDAY. SOME OF THE
HEAVIER INTERVALS OF RAIN MAY CAUSE SOME PONDING OF WATER ON
ROADWAYS.
WINDS WILL INCREASE AS WELL, THE GFS, ECMWF AND NAM ALL
SUGGEST WINDS AT 925 MB REACH AT LEAST 50 MPH BY SUNDAY MORNING SE
OF PHILADELPHIA. WHILE THE STRONGEST WINDS WILL LIKELY BE ON SUNDAY,
THE FORECAST DOES GO STRONGER THAN GUIDANCE WITH THE WINDS AFTER
MIDNIGHT TONIGHT. SOME EAST TO SOUTHEAST WIND GUSTS AROUND 25 MPH
ARE POSSIBLE BY SUNDAY MORNING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
500 MB: A NEGATIVE TILT SHORT WAVE RIPS NEWD THROUGH THE NORTHEAST
SUNDAY FOLLOWED BY THE DEVELOPMENT OF A FULL LATITUDE TROUGH ALONG
THE EAST COAST NEXT TUESDAY AND THEN WESTERLY FLOW DEVELOPS BY NEXT
THURSDAY BEFORE A NEW TROUGH FORMS IN THE CENTRAL USA NEXT WEEKEND.
TEMPERATURES: AFTER RECORD OR NEAR RECORD WARMTH SUNDAY AND MAXIMUM
TEMPERATURES NEARLY 25 DEGREES ABOVE NORMAL, CALENDAR DAY AVERAGES
WILL COOL TO NEAR NORMAL MONDAY AND TUESDAY, THEN SLIP A FEW DEGREES
BELOW NORMAL WEDNESDAY. THEREAFTER THERE IS SOME UNCERTAINTY...
BUT OVERALL NEAR OR SLIGHTLY BELOW NORMAL THURSDAY AND FRIDAY.
FORECAST BASIS: UNLESS OTHERWISE NOTED, A 50 50 BLEND 00Z/9 GFS/NAM
MOS GUIDANCE SUNDAY-SUNDAY NIGHT, THEREAFTER THE 00Z/9 GFS MEX MOS
MONDAY AND TUESDAY, THEN FOR TUESDAY NIGHT-FRIDAY GENERALLY THE
06Z/9 SUPERBLEND WHICH INCLUDES 00Z/9 GFS MEX GUIDANCE AND WPC
GUIDANCE.
THE DAILIES...
SUNDAY...A STORMY MORNING WITH AN OPPORTUNITY FOR A STRONG TSTM
IN STRONG SE INFLOW WITH INSTABILITY, ESPECIALLY ALOFT WHERE SWI
WILL BE BRIEFLY NEAR -2C, TT IN THE LOWER 50S AND RAPIDLY FALLING
SFC PRES. THIS COULD MEAN ISOLATED WIND GUSTS 40-50 MPH, ESPECIALLY
DELMARVA AND COASTAL NJ.
WE MAY EVENTUALLY NEED A WIND ADVY FOR THE NEAREST 5 MILES OF THE NJ
COAST IN THE 10Z-15Z TIME FRAME AND THIS IS WHERE I`VE GREATEST
CONFIDENCE ON VERIFYING NON CONVECTIVE 46 MPH SE WIND GUSTS.
BRIEF POOR DRAINAGE STREET FLOODING IN THE MORNING BUT OTRW NO
STREAM FLOODING EXPECTED.
TIDES WILL APPROACH MINOR ADVISORY STAGE IN THE 12Z-14Z TIME FRAME
BUT NO ADVISORY ATTM.
A WSHIFT TO WSW IN THE AFTERNOON WITH RECORD OR NEAR RECORD WARMTH
DURING MIDDAY BEGINNING TO BE SWEPT SEAWARD AND MAYBE ONE LAST
BAND OF SHOWERS PASSING EASTWARD AS A COLD FRONT MOVES THROUGH OUR
FORECAST AREA.
SUNDAY NIGHT...P/C, WINDY AND TURNING COLDER. GUSTY WEST WINDS 30-40
MPH. STRONG PRESSURE RISES DURING THE EVENING ACCOMPANIES THE INFLUX
OF COLDER DRIER AIR. SMALL CHC OF FLURRIES IN THE POCONOS.
MONDAY...DRY AND BREEZY. WESTERLY WIND GUSTS TO 25 MPH. .
TUESDAY...CHANCE OF SNOW SHOWERS OR FLURRIES IN THE DESTABILIZING
AIRMASS AS A STRONG TROUGH DEVELOPS ALONG THE EAST COAST. GUSTY
SOUTHWEST WINDS 20 TO 25 MPH SHIFTING TO WEST AT NIGHT WITH GUSTS
20 TO 30 MPH.
WEDNESDAY...WINDY AND COLD. DRY WITH EXCEPTION ALONG AND NORTH OF
I-78 WHERE THERE ARE MODEL INDICATIONS OF STEEP LAPSE RATES AND
POSSIBLE FLURRIES. WESTERLY WINDS WILL BE GUSTING 30 TO POSSIBLY
40 MPH.
THURSDAY...DIMINISHING WIND AND NOT QUITE AS COLD.
FRIDAY...UNCERTAINTY. FOR NOW, FORECASTING QUIET WEATHER (NOT THE
OUTLIER 00Z/9 ECMWF OPERATIONAL SOLUTION)
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
MOST LOCATIONS ARE CURRENTLY VARYING BETWEEN MVFR AND VFR
CEILINGS, WITH KRDG AND KABE MAINLY SEEING MVFR TO IFR CEILINGS.
THIS WILL LIKELY CONTINUE TILL ABOUT 16Z. LOCATIONS FROM KPHL TO
THE SOUTH AND EAST HAVE THE BEST CHANCE TO STAY VFR THE LONGEST
TODAY. THE GENERAL EXPECTATION WILL BE FOR CEILINGS TO LOWER TO
IFR THIS AFTERNOON AT ALL TAF SITES. HOWEVER, CONFIDENCE IS ONLY
MEDIUM AT THIS POINT THROUGH 23Z SATURDAY ON CEILINGS, SINCE THE
CEILINGS HAVE BEEN HIGHER THAN SUGGESTED FROM SOME OUR FORECASTING
TOOLS. VISIBILITIES WILL RANGE FROM MVFR TO VFR ACROSS THE REGION.
GENERAL EASTERLY WIND UNDER 10 KNOTS.
MUCH HIGHER CONFIDENCE TONIGHT FOR IFR CEILINGS WITH LOWERING
VISIBILITIES AND RAIN DEVELOPING BY 06Z SUNDAY FROM SOUTH TO
NORTH. IFR OR LOWER CEILINGS AND VISIBILITIES FROM 09Z INTO
SUNDAY MORNING WITH RAIN. WINDS WILL ALSO INCREASE AND BECOME MORE
SOUTHEASTERLY TOWARD SUNDAY MORNING AROUND 15 KNOTS WITH HIGHER
GUSTS TO 25 KNOTS. LLWS POSSIBLE FROM KPHL TO THE SOUTHEAST
TOWARD KACY AFTER 09Z SUNDAY. MODERATE CONFIDENCE IN LLWS.
OUTLOOK...
SUNDAY MORNING...EARLY IFR CONDITIONS IN SHOWERY-BRIEFLY HEAVY
RAINS. POSSIBLE ISOLATED TSTM. SE WINDS GUSTY 20-25 KT EXCEPT
POSSIBLY 40-45 KT IN A TSTM. LLWS VCNTY KMIV AND KACY.
SUNDAY AFTERNOON...BECOMING VFR CIGS AOA 3500 FT WITH A POSSIBLE
RESIDUAL BAND OF SHOWERS ACCOMPANY THE COLD FRONT. WINDS SHIFTING
SOUTHWEST THEN WEST AND GUSTY 25-35 KT.
SUNDAY NIGHT-MONDAY...MOSTLY VFR. GUSTY WEST-NORTHWEST WINDS
25-30 KT.
MONDAY NIGHT...VFR.
TUESDAY-WEDNESDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS BETWEEN 20
AND 25 KT TUESDAY, BECOMING WEST-NORTHWEST TUESDAY NIGHT INTO
WEDNESDAY. GUSTS INCREASING TO 30 TO 35 KT WEDNESDAY.
&&
.MARINE...
CURRENTLY WAVE HEIGHTS ARE SEVEN TO EIGHT FEET ON THE OCEAN WATERS
AND WILL CONTINUE TO BUILD SLOWLY INTO TONIGHT. WINDS WILL REMAIN
OUT OF THE EAST UNDER SCA CRITERIA TODAY BUT WILL RAMP UP AFTER
MIDNIGHT TONIGHT, REACHING 30 KNOTS TOWARD SUNRISE SUNDAY.
STRONGER WINDS A FEW THOUSAND FEET UP IN THE ATMOSPHERE MAY MIX
DOWN LEADING TO EVEN LOCALLY HIGHER WIND GUSTS TOWARD SUNRISE
SUNDAY.
ATLC COAST: SINCE ADVISORY SEAS ARE IN PROGRESS, WE CONTINUED THE
SCA HEADLINE INTO TONIGHT BUT THE SCA WILL PROBABLY BE DISCONTINUED
AT 330 PM FOR ONE PRIMARY HEADLINE AS GALE WARNING WINDS DRAW
CLOSER TO TIME ZERO.
DE BAY: SCA CANCELLED SINCE THE PREDOMINANT INTERMITTENT GALE ON
SUNDAY SUPERSEDES THE BRIEF TRANSITION FROM NON ADVISORY TO GALE
WARNING LATE TONIGHT.
OUTLOOK...
SEA SURFACE TEMPERATURES REMAIN VERY WARM FOR JANUARY...NEAR 50F
WHICH IS ABOUT 8 DEGREES ABOVE NORMAL. THIS CONTRIBUTES TO GREATER
INSTABILITY IN WESTERLY TO NORTHERLY FLOW COLD AIR PATTERNS AND
POSSIBLY STRONGER THAN MODELED WINDS. THIS COULD WELL AGAIN BE A
FACTOR IN STRONG COLD AIR ADVECTION WIND TRANSFER SUNDAY NIGHT.
SUNDAY-SUNDAY NIGHT...GALE WARNING ISSUED, FIRST FOR 1-3 HOURS SE
INFLOW GUSTS NEAR 35KT DURING THE MORNING. WE MAY NEED A SPECIAL
MARINE WARNING FOR ISOLATED TSTM GUSTS 40-45 KT. THEN A 9 TO 12
HOUR PERIOD OF WESTERLY GALES IS ANTICIPATED FOR LATE SUNDAY OR
MORE LIKELY SUNDAY NIGHT.
MONDAY-TUESDAY...OTHER THAN A BRIEF BREAK LATE MONDAY NIGHT INTO
EARLY TUESDAY, WINDS AND SEAS LIKELY TO REMAIN ABOVE SMALL CRAFT
CRITERIA THROUGH TUESDAY.
WEDNESDAY...THERE IS A HIGH PROBABILITY FOR GALE FORCE NORTHWEST
WIND GUSTS OF 35-40 KT.
&&
.TIDES/COASTAL FLOODING...
WITH THE NEW MOON TODAY AND AN INCREASING FLOW EASTERLY FLOW,
TIDES COULD APPROACH THE MINOR COASTAL FLOOD THRESHOLD, ESPECIALLY
SUNDAY. CURRENTLY THE TIDE WITH THE HIGHEST FORECAST IS SUNDAY
MORNING, BUT EVEN THIS MORNING IT WILL BE WITHIN AN INCH OR 2 OF
FLOOD ALONG THE ATLANTIC COAST.
FOR NOW ITS A MARGINAL CHANCE OF MINOR COASTAL FLOODING AND NO
ADVISORY IS BEING ISSUED ATTM.
ALSO, BEHIND THE STORM SYSTEM, STRONG NORTHWEST WINDS WILL DEVELOP.
CURRENT ETSS FORECASTS IN INDICATING THE POSSIBILITY OF APPROACHING
BLOW OUT FOR SOME AREAS, ESPECIALLY THE DELAWARE BAY AND POSSIBLY
THE TIDAL DELAWARE RIVER.
&&
.CLIMATE...
OUR 330 AM FORECAST HAS RECORD HIGHS FORECAST SUNDAY AT SEVERAL
LOCATIONS, INCLUDING KPHL, KTTN AND KRDG, WITH RECORD EQUALING OR
JUST A DEGREE SHY OF RECORD AT KACY, KILG, KABE, KGED.
DAILY RECORD HIGHS FOR SUNDAY JAN 10 ARE LISTED BELOW:
LOCATION RECORD YEAR
------------------------------
ATLANTIC CITY 63 1930
PHILADELPHIA 63 1950
WILMINGTON 64 1930
ALLENTOWN 60 1924
TRENTON 62 1950
GEORGETOWN 67 1950
READING 58 1939
MOUNT POCONO 57 1998
WE`LL BRING THE SNOW CLIMATOLOGY BACK EARLY NEXT WEEK ONCE WE GET
THROUGH THE SUNDAY WARM EVENT AND HAVE A BETTER FEEL FOR A COUPLE
OF SNOW THREATS NEXT WEEK.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ055.
NJ...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR ANZ450>455.
GALE WARNING FROM 5 AM SUNDAY TO 6 AM EST MONDAY FOR ANZ430-
431-450>455.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GAINES
SHORT TERM...GAINES
LONG TERM...DRAG 649A
AVIATION...DRAG/GAINES 649A
MARINE...DRAG/GAINES 649A
TIDES/COASTAL FLOODING... 649A
CLIMATE...649A
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
624 AM EST SAT JAN 9 2016
.SYNOPSIS...
HIGH PRESSURE FROM EASTERN CANADA DOWN TO THE MID ATLANTIC STATES
WEAKENS LATE TODAY. LOW PRESSURE IN THE OHIO VALLEY THIS EVENING
INTENSIFIES RAPIDLY IS IT CROSSES PENNSYLVANIA AND NEW YORK STATE
SUNDAY. IT DRAWS A STRONG WARM FRONT NORTHWARD THROUGH OUR AREA
SUNDAY MORNING, THEN A STRONG COLD FRONT PASSES OFF THE COAST
SUNDAY AFTERNOON. HIGH PRESSURE BUILDS TO OUR SOUTH LATE MONDAY.
GREAT LAKES LOW PRESSURE TUESDAY SENDS A STRONG COLD FRONT ACROSS
THE MID ATLANTIC STATES TUESDAY EVENING. THAT LOW REFORMS ALONG
COASTAL NEW ENGLAND AND INTENSIFIES RAPIDLY ON WEDNESDAY. HIGH
PRESSURE BUILDS TO OUR SOUTH ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR MONROE, PA AND
SUSSEX, NJ UNTIL 9 AM. TEMPERATURES ARE ABOVE FREEZING WITH THE
EXCEPTION OF SOME LOCATIONS IN MONROE AND SUSSEX COUNTIES. A FEW
SPOTTY SHOWERS OF FREEZING RAIN HAVE OCCURRED OVER THE PAST
COUPLE OF HOURS AND MAY CONTINUE TO DO SO FOR THE NEXT FEW HOURS.
OTHERWISE, TODAY LOOKS TO BE A CLOUDY DAY ACROSS THE REGION AS A
WARM FRONTAL BOUNDARY LIFTS NORTHWARD INTO NEW ENGLAND AND LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST UNTIED STATES COASTLINE. THIS
WILL RESULT IN WARMER AND MOISTER BEING ADVECTED INTO THE REGION
WITH EASTERLY WINDS FROM 5-10 MPH. DAYTIME TEMPERATURES SHOULD RISE
TO AROUND 50 FOR MOST LOCATIONS WITH THE POCONOS STRUGGLING TO GET
OUT OF THE UPPER 30`S. BOTH THE HRRR AND RAP MESOSCALE MODELS ARE
TRYING TO SPIT OUT A BRIEF SHOWER OR TWO TODAY, SO HAVE LOW OR
SLIGHT CHANCE POPS ACROSS THE REGION TODAY. THE MAJORITY OF THE
REGION WILL STAY DRY THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE LOW PRESSURE IN THE SOUTHEAST UNITED STATES WILL CONTINUE TO
MOVE QUICKLY NORTHWARD TONIGHT REACHING OUR AREA BY SUNDAY MORNING
WITH A WARM FRONT EXTENDING EAST OF THE LOW PRESSURE CENTER. AN
AGGRESSIVE LLJ MODELED NEAR 60 KNOTS WILL CONTINUE TO SEND NORTHWARD
WARMER AND MOIST AIR INTO THE REGION. MOISTURE LIFTING OVER THE WARM
FRONT WILL LEAD TO WIDESPREAD RAIN BREAKING OUT TO OUR SOUTH LATE
SATURDAY. THE RAIN WILL INCREASE IN COVERAGE AND INTENSITY AS THE
NIGHT GOES ON WITH ALL LOCATIONS SEEING A STEADY RAIN BY SUNDAY
MORNING. TEMPERATURES WILL ACTUALLY RISE OVERNIGHT AND THE FORECAST
DOES GO WARMER WITH THE TEMPERATURES OVERNIGHT THAN WHAT THE MAV/MET
GUIDANCE SUGGESTS DUE TO THE LLJ INFLUENCE. AROUND HALF AN INCH OF
RAIN SHOULD FALL TONIGHT WITH ADDITIONAL RAIN ON SUNDAY. SOME OF THE
HEAVIER INTERVALS OF RAIN MAY CAUSE SOME PONDING OF WATER ON
ROADWAYS.
WINDS WILL INCREASE AS WELL, THE GFS, ECMWF AND NAM ALL
SUGGEST WINDS AT 925 MB REACH AT LEAST 50 MPH BY SUNDAY MORNING SE
OF PHILADELPHIA. WHILE THE STRONGEST WINDS WILL LIKELY BE ON SUNDAY,
THE FORECAST DOES GO STRONGER THAN GUIDANCE WITH THE WINDS AFTER
MIDNIGHT TONIGHT. SOME EAST TO SOUTHEAST WIND GUSTS AROUND 25 MPH
ARE POSSIBLE BY SUNDAY MORNING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
500 MB: A NEGATIVE TILT SHORT WAVE RIPS NEWD THROUGH THE NORTHEAST
SUNDAY FOLLOWED BY THE DEVELOPMENT OF A FULL LATITUDE TROUGH ALONG
THE EAST COAST NEXT TUESDAY AND THEN WESTERLY FLOW NEXT THURSDAY
BEFORE A NEW TROUGH FORMS IN THE CENTRAL USA BY NEXT WEEKEND.
TEMPERATURES: AFTER RECORD OR NEAR RECORD WARMTH SUNDAY AND MAXIMUM
TEMPERATURES NEARLY 25 DEGREES ABOVE NORMAL, CALENDAR DAY AVERAGES
WILL COOL TO NEAR NORMAL MONDAY AND TUESDAY, THEN SLIP A FEW DEGREES
BELOW NORMAL WEDNESDAY. THEREAFTER THERE IS SOME UNCERTAINTY...
BUT OVERALL NEAR OR SLIGHTLY BELOW NORMAL THURSDAY AND FRIDAY.
FORECAST BASIS: UNLESS OTHERWISE NOTED, A 50 50 BLEND 00Z/9 GFS/NAM
MOS GUIDANCE SUNDAY-SUNDAY NIGHT, THEREAFTER THE 00Z/9 GFS MEX MOS
MONDAY AND TUESDAY, THEN FOR TUESDAY NIGHT-FRIDAY GENERALLY THE
06Z/9 SUPERBLEND WHICH INCLUDES 00Z/9 GFS MEX GUIDANCE AND WPC
GUIDANCE.
THE DAILIES...
SUNDAY...A STORMY MORNING WITH AN OPPORTUNITY FOR A STRONG TSTM
IN STRONG SE INFLOW WITH INSTABILITY, ESPECIALLY ALOFT WHERE SWI
WILL BE BRIEFLY NEAR -2C, TT IN THE LOWER 50S AND RAPIDLY FALLING
SFC PRES. THIS COULD MEAN ISOLATED WIND GUSTS 40-50 MPH, ESPECIALLY
DELMARVA AND COASTAL NJ.
WE MAY EVENTUALLY NEED A WIND ADVY FOR THE NEAREST 5 MILES OF THE NJ
COAST IN THE 10Z-15Z TIME FRAME AND THIS IS WHERE I`VE GREATEST
CONFIDENCE ON VERIFYING NON CONVECTIVE 46 MPH SE WIND GUSTS.
BRIEF POOR DRAINAGE STREET FLOODING IN THE MORNING BUT OTRW NO
STREAM FLOODING EXPECTED.
TIDES WILL APPROACH MINOR ADVISORY STAGE IN THE 12Z-14Z TIME FRAME
BUT NO ADVISORY ATTM.
A WSHIFT TO WSW IN THE AFTERNOON WITH RECORD OR NEAR RECORD
WARMTH DURING MIDDAY BEGINNING TO BE SWEPT SEAWARD AND MAYBE ONE
LAST BAND OF SHOWERS?.
SUNDAY NIGHT...P/C, WINDY AND TURNING COLDER. GUSTY WEST WINDS 30-40
MPH. STRONG PRESSURE RISES DURING THE EVENING ACCOMPANIES THE INFLUX
OF COLDER DRIER AIR. SMALL CHC OF FLURRIES IN THE POCONOS.
MONDAY...DRY.
TUESDAY...CHANCE OF SNOW SHOWERS OR FLURRIES IN THE DESTABILIZING
AIRMASS AS A STRONG TROUGH DEVELOPS ALONG THE EAST COAST. GUSTY
SOUTHWEST WINDS 20 TO 25 MPH SHIFTING TO WEST AT NIGHT WITH GUSTS
20 TO 30 MPH.
WEDNESDAY...WINDY AND COLD. DRY WITH EXCEPTION ALONG AND NORTH OF
I-78 WHERE MODEL INDICATIONS OF STEEP LAPSE RATES AND POSSIBLE
FLURRIES. WESTERLY WINDS WILL BE GUSTING 30 TO POSSIBLY 40 MPH.
THURSDAY...DIMINISHING WIND AND NOT QUITE AS COLD.
FRIDAY...UNCERTAINTY. FOR NOW, FORECASTING QUIET WEATHER (NOT THE
00Z/9 ECMWF OPERATIONAL SOLUTION)
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
MOST LOCATIONS ARE CURRENTLY VARYING BETWEEN MVFR AND VFR
CEILINGS, WITH KRDG AND KABE MAINLY SEEING MVFR TO IFR CEILINGS.
THIS WILL LIKELY CONTINUE TILL ABOUT 16Z. LOCATIONS FROM KPHL TO
THE SOUTH AND EAST HAVE THE BEST CHANCE TO STAY VFR THE LONGEST
TODAY. THE GENERAL EXPECTATION WILL BE FOR CEILINGS TO LOWER TO
IFR THIS AFTERNOON AT ALL TAF SITES. HOWEVER, CONFIDENCE IS ONLY
MEDIUM AT THIS POINT THROUGH 23Z SATURDAY ON CEILINGS, SINCE THE
CEILINGS HAVE BEEN HIGHER THAN SUGGESTED FROM SOME OUR FORECASTING
TOOLS. VISIBILITIES WILL RANGE FROM MVFR TO VFR ACROSS THE REGION.
GENERAL EASTERLY WIND UNDER 10 KNOTS.
MUCH HIGHER CONFIDENCE TONIGHT FOR IFR CEILINGS WITH LOWERING
VISIBILITIES AND RAIN DEVELOPING BY 06Z SUNDAY FROM SOUTH TO
NORTH. IFR OR LOWER CEILINGS AND VISIBILITIES FROM 09Z INTO
SUNDAY MORNING WITH RAIN. WINDS WILL ALSO INCREASE AND BECOME MORE
SOUTHEASTERLY TOWARD SUNDAY MORNING AROUND 15 KNOTS WITH HIGHER
GUSTS TO 25 KNOTS. LLWS POSSIBILE FROM KPHL TO THE SOUTHEAST
TOWARD KACY AFTER 09Z SUNDAY. MODERATE CONFIDENCE IN LLWS.
OUTLOOK...
SUNDAY MORNING...EARLY IFR CONDITIONS IN SHOWERY BRIEFLY HEAVY
RAINS, POSSIBLE ISOLATED TSTM. SE WINDS GUSTY 20-25 KT EXCEPT
POSSIBLY 40-45 KT IN A TSTM. LLWS VCNTY KMIV AND KACY.
SUNDAY AFTERNOON...BECOMING VFR CIGS AOA 3500 FT WITH A POSSIBLE
RESIDUAL BAND OF SHOWERS ACCOMPANY THE COLD FRONT. WINDS SHIFTING
SOUTHWEST THEN WEST AND GUSTY 25-35 KT.
SUNDAY NIGHT-MONDAY...MOSTLY VFR. GUSTY WEST-NORTHWEST WINDS
25-30 KT.
MONDAY NIGHT...VFR.
TUESDAY-WEDNESDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS BETWEEN 20
AND 25 KT TUESDAY, BECOMING WEST-NORTHWEST TUESDAY NIGHT INTO
WEDNESDAY. GUSTS INCREASING TO 30 TO 35 KT WEDNESDAY.
&&
.MARINE...
CURRENTLY WAVE HEIGHTS ARE SIX TO SEVEN FEET ON THE OCEAN WATERS
AND WILL CONTINUE TO BUILD SLOWLY THROUGH THE DAY TODAY AND INTO
TONIGHT. WINDS WILL REMAIN OUT OF THE EAST UNDER SCA CRITERIA
TODAY BUT WILL RAMP UP AFTER MIDNIGHT TONIGHT, REACHING 30 KNOTS
TOWARD SUNRISE SUNDAY. STRONGER WINDS A FEW THOUSAND FEET UP IN
THE ATMOSPHERE MAY MIX DOWN LEADING TO EVEN LOCALLY HIGHER WIND
GUSTS TOWARD SUNRISE SUNDAY.
ATLC COAST: SINCE ADVISORY SEAS ARE IN PROGRESS, WE CONTINUED THE
SCA HEADLINE INTO TONIGHT BUT THE SCA WILL PROBABLY BE DISCONTINUED
AT 330 PM FOR ONE PRIMARY HEADLINE AS GALE WARNING WINDS DRAW
CLOSER TO TIME ZERO.
DE BAY: SCA CANCELLED SINCE THE PREDOMINANT INTERMITTENT GALE ON
SUNDAY SUPERSEDES THE BRIEF TRANSITION FROM NON ADVISORY TO GALE
WARNING EARLY SUNDAY.
OUTLOOK...
SEA SURFACE TEMPERATURES REMAIN VERY WARM FOR JANUARY...NEAR 50F
WHICH IS ABOUT 8 DEGREES ABOVE NORMAL. THIS CONTRIBUTES TO GREATER
INSTABILITY IN WESTERLY TO NORTHERLY FLOW COLD AIR PATTERNS AND
POSSIBLY STRONGER THAN MODELED WINDS. THIS COULD WELL AGAIN BE A
FACTOR IN STRONG COLD AIR ADVECTION WIND TRANSFER SUNDAY NIGHT.
SUNDAY-SUNDAY NIGHT...GALE WARNING ISSUED, FIRST FOR 1-3 HOURS SE
INFLOW GUSTS NEAR 35KT DURING THE MORNING. WE MAY NEED A SPECIAL
MARINE WARNING FOR ISOLATED TSTM GUSTS 40-45 KT. THEN A 9 TO 12
HOUR PERIOD OF WESTERLY GALES IS ANTICIPATED FOR LATE SUNDAY OR
MORE LIKELY SUNDAY NIGHT.
MONDAY-TUESDAY...OTHER THAN A BRIEF BREAK LATE MONDAY NIGHT INTO
EARLY TUESDAY, WINDS AND SEAS LIKELY TO REMAIN ABOVE SMALL CRAFT
CRITERIA THOUGH TUESDAY.
WEDNESDAY...THERE IS A HIGH PROBABILITY FOR GALE FORCE NORTHWEST
WIND GUSTS OF 35-40 KT.
&&
.TIDES/COASTAL FLOODING...
WITH THE NEW MOON ON SATURDAY AND AN INCREASING FLOW EASTERLY
FLOW, TIDES COULD APPROACH THE MINOR COASTAL FLOOD LEVEL SUNDAY.
CURRENTLY THE TIDE WITH THE HIGHEST FORECAST IS SUNDAY MORNING.
FOR NOW ITS A MARGINAL CHANCE OF MINOR COASTAL FLOODING AND NO
ADVISORY IS BEING ISSUED ATTM.
ALSO, BEHIND THE STORM SYSTEM, STRONG NORTHWEST WINDS WILL DEVELOP.
CURRENT ETSS FORECASTS IN INDICATING THE POSSIBILITY OF APPROACHING
BLOW OUT FOR SOME AREAS, ESPECIALLY THE DELAWARE BAY AND POSSIBLY
THE TIDAL DELAWARE RIVER.
&&
.CLIMATE...
RECORD HIGHS LIKELY SUNDAY AT SEVERAL LOCATIONS.
DAILY RECORD HIGHS FOR SUNDAY JAN 10 ARE LISTED BELOW:
LOCATION RECORD YEAR
------------------------------
ATLANTIC CITY 63 1930
PHILADELPHIA 63 1950
WILMINGTON 64 1930
ALLENTOWN 60 1924
TRENTON 62 1950
GEORGETOWN 67 1950
READING 58 1939
MOUNT POCONO 57 1998
WE`LL BRING THE SNOW CLIMATOLOGY BACK EARLY NEXT WEEK ONCE WE GET
THROUGH THE SUNDAY WARM EVENT AND HAVE A BETTER FEEL FOR A COUPLE
OF SNOW THREATS NEXT WEEK.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ055.
NJ...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR ANZ450>455.
GALE WARNING FROM 5 AM SUNDAY TO 6 AM EST MONDAY FOR ANZ430-
431-450>455.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GAINES
SHORT TERM...GAINES
LONG TERM...DRAG
AVIATION...DRAG/GAINES
MARINE...DRAG/GAINES
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1005 AM EST SAT JAN 9 2016
.DISCUSSION...
...WARMER THIS AFTERNOON...
...SLIGHT CHANCE OF THUNDERSTORMS THIS EVENING...
.UPDATE...AREA OF STRATUS AND FOG AFFECTING EAST CENTRAL FL THIS
MORNING SHOULD BREAK UP AND DISSIPATE INTO MID DAY AS LOW LVL FLOW
TURNS SOUTHERLY AHEAD OF THE NEXT APPROACHING FRONT LATER TONIGHT.
SHORT RANGE MODELS INCLUDING THE HRRR BRING GULF CONVECTION TWD LAKE
COUNTY BETWEEN 5 AND 7 PM AND THEN EASTWARD ACROSS E CENTRAL FL THIS
EVENING. WILL MAKE ONLY MINOR ADJUSTMENTS TO FCST WITH HIGHS STILL
EXPECTED TO REACH THE UPPER 70S TO LOWER 80S ONCE MORNING STRATUS
DECK BREAKS UP. COULD BE A FEW STRONGER STORMS WITH LOCALLY HEAVY
RAIN AND GUSTY WINDS PUSHING INTO THE INTERIOR FROM THE WESTERN
PENINSULA THIS EVENING WITH MID LAYER FLOW AT 500 MBS TO 45-55
KNOTS AND H5 TEMPS COOLING A DEG OR TWO TO -11 TO -12 DEGS C THIS
EVENING.
&&
.AVIATION... LOW STRATUS AND FOG SHOULD BREAK UP AND LIFT BY 17Z AND
BECOMING VFR MOST AREAS BY 18Z. HRRR INDICATES GULF CONVECTION MAY
APPROACH KLEE 22Z-24Z AND AFFECT REMAINDER OF INTERIOR TERMINALS AND
POSSIBLY CSTL TERMINALS LATER INTO THE EVENING.
&&
.MARINE... UPDATE...NW WINDS THIS MORNING WILL BECOME S/SW THIS AFTN
AHEAD OF THE NEXT FRONTAL SYSTEM APPROACHING THE AREA TONIGHT.
SWELLS AT BUOY 41009 RUNNING SLIGHTLY HIGHER THAN GUID THIS MORNING
TO 7-8 FT. WILL CONTINUE EXERCISE CAUTION HEADLINES ALL MARINE AREAS
INTO THE AFTERNOON WITH SEAS TO 7 FT OFFSHORE. PREVIOUS DISCUSSION...
TODAY/TONIGHT...LOW PRESSURE IS FORECAST TO LIFT NE FROM THE LOWER MS
VALLEY AND STRENGTHEN AS IT REACHES THE EASTERN GREAT LAKES TONIGHT.
A WEAK INVERTED TROUGH ANALYZED JUST OFFSHORE THE FL EAST COAST WILL
PRODUCE A LIGHT NORTH FLOW ALONG THE COAST THIS MORNING. BUT WINDS
WILL SHIFT OUT OF THE S TO SW LATER THIS MORNING AND AFTERNOON AS AN
APPROACHING SYSTEM RAPIDLY MOVES EAST FROM THE GULF OF MEXICO. WIND
SPEEDS WILL BE AROUND 10 KNOTS THIS AFTERNOON BUT INCREASE 15-20
KNOTS OFFSHORE TONIGHT AHEAD OF A COLD FRONT. RAIN CHANCES LOOK
QUITE LOW OVER THE ATLC WATERS DURING THE DAY BUT FAST MOVING
SHOWERS WILL APPROACH FROM THE WEST BY EARLY EVENING INTO THE
OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 78 62 73 43 / 20 40 10 0
MCO 80 64 77 45 / 30 40 10 0
MLB 80 66 79 46 / 20 40 20 0
VRB 81 66 80 49 / 20 40 30 10
LEE 79 63 73 44 / 40 40 10 0
SFB 80 63 74 44 / 30 40 10 0
ORL 81 65 75 48 / 30 40 10 0
FPR 81 66 80 49 / 20 40 30 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
VOLKMER/SPRATT
AREA FORECAST DISCUSSION
NWS MIAMI FL
942 AM EST SAT JAN 9 2016
.UPDATE...
EARLY MORNING FOG CONTINUES TO BURN OFF, ALTHOUGH SOME AREAS OF
LOW VISIBILITY REMAIN, ESPECIALLY ALONG ALLIGATOR ALLEY AND U.S.
27. THE FOG SHOULD BE GONE BY 11 AM, IF NOT SOONER AS DEPTH OF THE
FOG LAYER IS QUITE SHALLOW.
PSEUDO-WARM FRONT OVER THE KEYS AND STRAITS OF FLORIDA, AS
DEPICTED ON VISIBLE SATELLITE IMAGERY AS A THIN BAND OF CLOUDS,
WILL MOVE NORTH TODAY AND LEAD TO SW WINDS AND SLOWLY INCREASING
MOISTURE ACROSS SOUTH FLORIDA. A WEAK SEA BREEZE COULD TRY TO PUSH
ONSHORE THE EAST COAST THIS AFTERNOON. INSTABILITY REMAINS
LIMITED TODAY ALTHOUGH WITH MODERATELY STRONG WIND FIELDS/DEEP-
LAYERED SHEAR OVERHEAD, IT WOULDN`T TAKE A LOT OF INSTABILITY TO
TRIGGER A FEW TSTMS TODAY. FOR NOW WILL KEEP FORECAST AS
IS...WHICH IS FOR ISOLATED SHOWERS AREA-WIDE.
SOME DISAGREEMENT AMONG MODEL SUITE REGARDING PRECIP TONIGHT IN
ADVANCE OF THE COLD FRONT. HRRR AND SOME OF THE WRF GUIDANCE
BRINGS PRECIP ONSHORE GULF COAST LATE THIS AFTERNOON, WHILE THE
RUC AND GLOBAL MODELS HOLD OFF UNTIL THIS EVENING/TONIGHT. CURRENT
FORECAST HAS GOOD TREND OF INCREASING RAIN CHANCES BETWEEN 00Z-
12Z. COULD SEE A FEW TSTMS TONIGHT AND MAY HAVE TO INTRODUCE
THUNDER TO FORECAST IN LATER UPDATES. /MOLLEDA
&&
.PREV DISCUSSION... /ISSUED 700 AM EST SAT JAN 9 2016/
AVIATION...
MAIN CONCERN THROUGH MID-MORNING IS LOW VISIBILITY/IFR CONDITIONS
IN FOG ACROSS MUCH OF SOUTH FLORIDA. SEVERAL SITES REPORTING SFC
VISIBILITY BELOW 1SM IN FOG AT 12Z THIS MORNING, BUT FOG IS
PATCHY AND SHALLOW AND AREAS NEAR/ALONG THE EAST COAST HAVE
ALREADY BROKEN OUT OF THE FOG. THEREFORE, EXPECT SIGNIFICANT
IMPROVEMENT BY 13Z, WITH MOST IF NOT ALL AREAS VFR BY 14Z. SFC WINDS
PREVAILING SW AHEAD OF A COLD FRONT IN THE GULF OF MEXICO WHICH
WILL BE AFFECTING THE AREA ON SUNDAY. MODELS SUGGEST A WEAK
SEA BREEZE COULD FORM ALONG THE IMMEDIATE EAST COAST, BUT WIND
SPEEDS ARE EXPECTED TO BE 10 KT OR LESS. MOISTURE INCREASES FROM
THE GULF OF MEXICO LATE TODAY AND TONIGHT, WITH SHOWERS MOVING
ONSHORE GULF COAST/KAPF THIS AFTERNOON AND TONIGHT. /MOLLEDA
PREV DISCUSSION... /ISSUED 420 AM EST SAT JAN 9 2016/
.ACTIVE WEATHER PATTERN FOR SOUTH FL INTO NEXT WEEK...
DISCUSSION...
A CHANGEABLE, ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS SOUTH
FLORIDA INTO NEXT WEEK, POTENTIALLY REVVING UP DURING THE LATTER
PART OF NEXT WEEK...IN EL NINO STYLE.
THE MAIN IMPACT IN THE NEAR TERM IS DENSE FOG. THIS FOG HAS
BECOME FAIRLY WIDESPREAD OVER THE INTERIOR AND GULF COAST WITH
VISIBILITIES REPORTED LESS THAN A QUARTER OF MILE NEAR THE LAKE
AND NAPLES CONSISTENTLY NOW RECORDING M1/4SM. FOR THIS REASON, A
DENSE FOG ADVISORY WAS ISSUED FOR THE INTERIOR AND GULF COAST. FOG
IS PATCHY ACROSS THE EAST COAST METRO AND MAINLY IN THE 1-3SM
RANGE. WILL MONITOR VISIBILITY TRENDS TO SEE IF THE ADVISORY MAY
NEED AN EXPANSION EAST EARLY THIS MORNING.
AFTER THE FOG DISSIPATED BY MID MORNING...SKIES WILL BE PARTLY
SUNNY WITH DRY WEATHER PREVAILING. HOWEVER, THE NEXT IN A SERIES
OF SHORTWAVES WILL APPROACH FROM THE EASTERN GULF...BUT THIS WILL
BE LATE IN THE DAY, SO ALTHOUGH THERE IS THE POTENTIAL OF A FEW
SHOWERS DEVELOPING ACROSS SOUTH FL...IT APPEARS THE FOCUS WILL
REMAIN OFF TO THE WEST AND NORTH. GIVEN THIS AND ONLY MARGINAL
INSTABILITY, HAVE KEPT TSTORM MENTION OUT OF THE FORECAST FOR
TODAY.
LOW PRESSURE DEVELOPING OVER THE MID SOUTH WILL MOVE QUICKLY UP
THE TENNESSEE VALLEY REGION AND INTO THE EASTERN GREAT LAKES
THROUGH SUNDAY. ITS ASSOCIATED COLD FRONT WILL MOVE ACROSS
NORTHERN AND CENTRAL FL ON SUNDAY...SWEEPING ACROSS SOUTH FL
SUNDAY EVENING. MOISTURE AHEAD OF THIS FRONT LOOKS SUFFICIENT FOR
SCATTERED SHOWERS TONIGHT-SUNDAY. INSTABILITY LOOKS JUST TOO
MARGINAL WHILE THE MAIN ENERGY REMAINS DISPLACED OFF NORTH OF THE
AREA TO SUPPORT AN APPRECIABLE TSTORM RISK, SO FOR NOW HAVE KEPT
TSTORM MENTION OUT IN ADVANCE OF THIS FRONT.
MUCH COOLER AND DRIER AIR WILL ADVECT DOWN THE PENINSULA ON
NORTHERLY WINDS SUN NIGHT-MON. SO WHILE THIS WEEKEND WILL BE WARM
AND MODERATELY HUMID, A NOTICEABLE CHANGE WILL OCCUR BY MONDAY. IN
FACT...HIGHS ON MONDAY ARE FORECAST TO REMAIN IN THE 60S ACROSS
THE LAKE OKEECHOBEE REGION AND ONLY AROUND 70 ELSEWHERE.
THE AFOREMENTIONED FRONT DOESN`T GET TOO FAR SOUTH THOUGH...AND
YET ANOTHER SHORTWAVE IS FORECAST TO MOVE ACROSS THE GULF AND
ACROSS SOUTH FL ON TUE. THIS WILL RESULT IN AN OVERRUNING
SITUATION WITH SHOWERS TO BREAK OUT AS WARMER AIR ALOFT GLIDES
OVER THE RELATIVELY COOLER SURFACE AIRMASS THAT WILL BE IN PLACE.
HOW WET IT GETS ON TUESDAY IS IN QUESTION. STAYED CLOSE TO THE
MODEL BLENDS IN THE 50-60% RANGE, BUT WOULD NOT DOUBT POPS GO
HIGHER SOUTHERN LOCALES WITH TIME.
THAT SHORTWAVE DEPARTS TUE NIGHT WITH A DRY DAY FORECAST FOR
WEDNESDAY AHEAD OF THE NEXT POTENTIALLY MORE VIGOROUS SHORTWAVE.
GFS AND ECMWF SHOW THIS ENERGY ENTERING THE GULF OF MEXICO ON
THURSDAY THEN MOVING ACROSS FLORIDA THURSDAY NIGHT. BOTH
OPERATIONAL RUNS ARE BULLISH WITH SURFACE LOW PRESSURE
DEVELOPMENT...BUT MANY ENSEMBLE MEMBERS ARE LESS AGGRESSIVE...NO
SURPRISE THIS FAR OUT. HOWEVER, GIVEN THAT BOTH OPERATIONAL RUNS
OF GFS/ECMWF SHOW QUICK MOISTURE RECOVERY LATE THU ALONG WITH
IMPRESSIVE WIND FIELDS...IT IS A TIMEFRAME IN THE EXTENDED THAT
WE WILL BE MONITORING FOR POTENTIAL SEVERE THUNDERSTORMS. THERE IS
LOW CONFIDENCE NOW (AFTER ALL THIS ENERGY IS ALL THE WAY OUT IN
THE PACIFIC AT AROUND 158W!), BUT GIVEN THAT THIS EL NINO IS TIED
NOW FOR THE STRONGEST ON RECORD, AND WE KNOW THAT EL NINO`S FAVOR
AN UPTICK IN SEVERE WEATHER/TORNADOES ACROSS FLORIDA, WE WILL BE
MONITORING THIS CLOSELY IN THE DAYS AHEAD. /GREGORIA
MARINE...
NO HEADLINES NEEDED. A LONG PERIOD NE SWELL WILL CONTINUE TO
SLOWLY SUBSIDE ACROSS THE ATLANTIC WATERS. WINDS WILL PICK UP
WHILE TURNING NORTHERLY BEHIND A COLD FRONT SUN NIGHT-MON...BUT
RIGHT NOW SEAS ARE FORECAST TO REMAIN BELOW 7 FT. /GREGORIA
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 69 82 58 / 20 20 40 20
FORT LAUDERDALE 83 69 83 60 / 20 20 40 20
MIAMI 83 71 83 62 / 20 20 40 20
NAPLES 79 69 79 58 / 20 40 50 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 7 PM EST THIS EVENING FOR FLZ168-172-
173.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
920 AM EST SAT JAN 9 2016
.Near Term [Through Today]...
Water vapor imagery shows and upper low over Oklahoma this morning.
Surface analysis shows weakening low pressure over Arkansas with
another low developing closer to the Gulf of Mexico (GOMEX) near
coastal Louisiana. A warm front is developing southeastward from
this low over the eastern GOMEX southwest of our marine area.
Regional radars show a cluster of thunderstorms tracking eastward
south of the MS/AL coastline. This is a remnant of a more organized
squall line that tracked across the Mississippi River overnight. The
12Z KTAE sounding sampled the 145-kt jet stream that extends across
the northern GOMEX. The sounding also shows the stable air mass is
place across the Big Bend.
Little has changed in our overall assessment of today`s severe
weather potential. We will find ourselves in a high-shear, low-CAPE
environment that is typical when frontal systems traverse the Gulf
Coast during winter. Deep layer shear values will be in the
impressive 70-85 knot range, but remain largely displaced northward
from the deep moisture and instability over the GOMEX. There is a
narrow zone where we could see sufficient overlap of shear and
instability to allow severe storms to develop. That includes our
coastal counties and marine area. The locally developed DVD severe
weather parameter from the 13Z RAP indicates this will mainly occur
in the afternoon and evening hours once the surface low tracks more
toward the northeast allowing the warm front to edge closer to the
coast. ECAM probabilities for severe gusts and strong updraft
helicity has been scaled back from what we were seeing yesterday to
include the same geographic threat area and SPC`s marginal risk
areas generally depicts this as well. The threat will be for
isolated damaging wind gusts and perhaps a tornado.
&&
.Hydrology...
The low pressure system today will, on average, bring less than a
quarter of an inch of rain across southeast Alabama and south
Georgia. Across north Florida, a half inch will be more common.
Isolated rainfall totals between 1 to 2 inches will be possible
should a strong thunderstorm reach land areas south of interstate
10. In general, this event is not expected to have a significant
impact on river levels or trends. The lower Choctawhatchee and
Apalachicola rivers remain at moderate flood levels this morning.
Though levels are steadily lowering across these rivers, they`ll
likely remain in flood for several more days. The lower Flint
River will drop below flood stage this evening.
&&
.Prev Discussion [626 AM EST]...
.Short Term [Tonight Through Monday]...
The shortwave currently over central Texas is forecast to be over
the Mississippi and Tennessee valleys by this evening and embedded
within the large, broad full CONUS trough. At the surface, low
pressure centered over the Ohio and Tennessee valleys is forecast
to move through the Midwest tonight and the Northeast on Sunday.
Much, if not all of the day`s convection will likely be through
the region by this evening. Should convection linger into the
evening a bit it will primarily be focused across the southeast
Big Bend of Florida, with a weakening rain shield over south-
central Georgia. The potential for an isolated severe storm will
still exist across primarily Taylor, Lafayette, and Dixie counties
early this evening. The primary threat with any supercells that
develop will be tornadoes and damaging winds.
After tonight, surface ridging will build into the Southeast
behind a cold front. Temperatures will fall to below seasonal
averages Sunday through Monday, with highs ranging from the upper
40s across southeast Alabama tomorrow, to the mid 60s across the
southeast Big Bend of Florida. Low to mid 50s will be common
area-wide on Monday. CAA from Sunday will linger into Sunday
night, forcing lows into the upper 20s across southeast Alabama
and southwest Georgia, up to the upper 30s across the southeast
Big Bend. Wind chill readings will essentially make it feel like
30 degrees and below, with some spots nearing the 20 degree wind
chill mark in the coldest spots.
.Long Term [Monday Night Through Saturday]...
The below normal temperatures will continue through Thursday as
another cold front (with no rain), moves through the region on
Tuesday. Monday night will be the closest to a radiational cooling
event, with little to no wind. CAA and wind chills are expected
again on Tuesday and Wednesday nights. Highs will remain solidly
in the 50s through Thursday, with overnight lows in the 30s. Wind
chills on Tues/Wed nights will likely only fall into the middle
20s across southeast Alabama and southwest Georgia.
Thursday through Saturday, models are essentially split and
cannot agree on placement or strength of a developing Gulf low.
Though, moderating temperatures and a chance for rain will likely
return by the end of the period.
.Aviation...
[Through 12Z Sunday] Expect patchy fog this morning. Current
visibilities are IFR and better. Most CIGs throughout the region
are currently LIFR and are forecast to become IFR after daybreak.
Showers and thunderstorms will move in to the region from the west
by late morning/early afternoon. A few storms may be severe,
particularly in the Florida counties. If these storms are able to
organize, the primary threat will be damaging winds and brief
tornadoes. MVFR conditions are likely beginning in the late
morning/early afternoon hours.
.Marine...
Cautionary level winds are expected through Sunday night, ahead
of, and in the wake of a passing cold front. Another uptick in
winds will be possible behind a cold front early next week, though
at this time appear to remain below headline levels. Finally, late
next week there is the potential for another enhancement in winds
and seas associated with a developing Gulf low.
.Fire Weather...
With a moist air mass in place, there are no fire weather
concerns for this weekend. On Monday, a very dry air mass will
invade the region. Red Flag conditions are a possibility on
Monday.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 70 54 56 34 55 / 80 20 0 0 0
Panama City 69 54 55 36 52 / 80 10 0 0 0
Dothan 65 47 49 29 52 / 80 30 0 0 0
Albany 66 50 52 29 52 / 80 40 0 0 0
Valdosta 70 55 57 33 55 / 60 60 0 0 0
Cross City 75 59 64 39 59 / 50 60 0 0 0
Apalachicola 70 57 58 39 54 / 80 10 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through late tonight FOR Coastal Bay-
Coastal Franklin-Coastal Gulf-South Walton.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...WOOL
SHORT TERM...HARRIGAN
LONG TERM...HARRIGAN
AVIATION...MCDERMOTT
MARINE...HARRIGAN
FIRE WEATHER...MCDERMOTT
HYDROLOGY...HARRIGAN
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
511 AM EST SAT JAN 9 2016
.DISCUSSION...
TODAY...A STRONGER AND DEEPER SHORT WAVE TROUGH THAN WE HAVE SEEN
THIS SEASON WILL PUSH FROM THE SOUTHERN PLAINS THIS MORNING TO THE
NORTHEAST STATES SUNDAY. THE SOUTHERN STREAM JET AXIS NOSING INTO
THE WESTERN GULF OF MEXICO TODAY WILL LIFT STEADILY INTO THE
SOUTHEAST STATES. THIS WILL KEEP THE MAIN LARGE SCALE ASCENT NORTH
OF OUR AREA AS THE ASSOCIATED SFC LOW OVER THE SOUTHERN MS VALLEY
DEEPENS AND MOVES INTO THE EASTERN GREAT LAKES SUNDAY MORNING.
THE GFS SHOWS SOME CLUSTERS OF CONVECTION OVER THE GULF OF MEXICO
AHEAD OF THE APPROACHING COLD FRONT BUT ITS MODEL QPF AND MOS
POPS ARE 10 PERCENT OR LESS NOT ONLY TODAY BUT ALSO TONIGHT. THE
ECMWF IS ALSO MOSTLY DRY FOR TODAY BUT SHOWS 20 POP FOR LEE AND
BRINGS 40 POP ACROSS THE AREA TONIGHT. THE ATMOS DOES HAS SOME
MOISTENING TO DO BUT AS WE SAW RECENTLY...IT CAN MOISTEN QUICKLY.
THE HRRR MODEL CONTINUES TO SHOW RAPID EASTWARD MOVEMENT OF PRECIP
SHIELD REACHING LAKE COUNTY AROUND SUNSET AND METRO ORLANDO/I 4
CORRIDOR EARLY IN THE EVE. HAVE LEANED TOWARD THIS SOLUTION IN POP
DISTRIBUTION SHOWING RAIN FREE CONDITIONS MOST OF THE DAY ALL
AREAS THEN SCATTERED SHOWERS I 4 CORRIDOR EARLY IN THE EVE.
THE OTHER FORECAST CHALLENGE IS PROSPECT FOR THUNDER. DESPITE
ABOVE NORMAL TEMPERATURES IN THE LOWER 80S...CONSIDERABLE
CLOUDINESS AND WEAK DESTABILIZATION WILL COMBINE WITH TIMING OF
BEST PRECIP CHANCES TO LIMIT DEEP CONVECTION TO AN EXTENT. THE
BEST CHANCE MAY OCCUR LATE TODAY/EARLY THIS EVE AS INITIAL
CONVECTION PUSHES ONSHORE THE FL GULF COAST. SO HAVE DRAWN A
SLIGHT CHANCE FOR THUNDER INITIALLY IN LAKE COUNTY AND GRADUALLY
SPREAD THAT SLIGHT CHANCE ACROSS THE REMAINDER OF EC FL THE REST
OF THE EVE. BUT THREAT FOR THUNDER LOOKS TOO LOW TO MENTION AFTER
MIDNIGHT. RISK OF SEVERE STORMS APPEARS VERY LOW.
SUN-MON...NEARLY ZONAL (WSW) FLOW ALOFT DURING THIS PERIOD AS
SHORTWAVE ENERGY REMAINS CONFINED TO THE GULF COAST STATES AND
FURTHER NORTH. A COLD FRONT OVER CENTRAL FL EARLY IN THE PERIOD WILL
CONTINUE TO ADVANCE SOUTHEAST AND FINALLY EAST OF THE AREA BY
AFTERNOON. NORTHWEST WINDS AROUND 15 MPH WILL FOLLOW THE BOUNDARY AS
HIGH PRESSURE BUILDS INTO THE DEEP SOUTH THROUGH THE PERIOD. THERE
MAY BE ISOLD-SCT SHOWERS SOUTH OF A LINE FROM NEAR TITUSVILLE-
KISSIMMEE ON SUN BUT CONDITIONS SHOULD GRADUALLY IMPROVE FROM NORTH
TO SOUTH DURING THE DAY. MAINLY DRY CONDITIONS FORECAST SUN NIGHT-
MON EVENING...EXCEPT POTENTIALLY LATE NIGHT SHOWERS MON OVERNIGHT
OVER THE TREASURE COAST AS THERE MAY BE SOME RETURN MOISTURE HERE.
HIGHS ON SUN SHOULD RECOVER INTO THE L-M70S ALONG/NORTH OF I-
4...EXCEPT U70S TO AROUND 80 DEGREES SOUTH OF HERE. LOWS ON SUN
NIGHT COMING IN COOLER NOW AND IN THE 40S...EXCEPT L50S ALONG THE
IMMEDIATE SAINT LUCIE/MARTIN COASTS. IF WINDS WERE TO REMAIN A BIT
MORE ELEVATED EXPECT THESE LOWS TO BE A BIT HIGHER. HIGHS ON MON
COOLER AND MAINLY IN THE 60S AREAWIDE. CHILLY AGAIN MON NIGHT WITH
SIMILAR TEMPERATURES AS THE PREVIOUS NIGHT.
TUE-FRI...THE SOUTHERN JET STREAM REMAINS FAIRLY ACTIVE THROUGH THE
PERIOD WITH WINDS OF 120-150KTS ACROSS THE REGION AT 250MB. NEARLY
ZONAL FLOW WILL EXIST AT 500MB THROUGH THE PERIOD THOUGH SHORTWAVE
IMPULSES WILL BE FEW ACROSS THE AREA INTO EARLY THU. REINFORCING
HIGH PRESSURE WILL MOVE DOWN INTO THE DEEP SOUTH ON WED...INTO THE
SOUTHEAST U.S. WED OVERNIGHT AND QUICKLY OFF OF THE COAST INTO THE
WESTERN ATLC ON THU.
WHILE TIMING/PLACEMENT OF FEATURES ARE NOT PRESENTLY CONSISTENT BOTH
THE GFS/ECMWF NOW HINT AT THE NEXT WEATHER SYSTEM ORGANIZING ACROSS
SOUTH TEXAS/WESTERN GULF WED OVERNIGHT AND MOVING ALONG THE GULF
COAST DURING THE DAY ON THU AND ACROSS THE FLORIDA PENINSULA THU
NIGHT/EARLY FRI. SOME POTENT SHORTWAVE ENERGY IS ALSO CURRENTLY
FORECAST TO ACCOMPANY THIS SYSTEM. IF THIS WERE TO HOLD TRUE THE
WIND FIELD AHEAD OF THIS SYSTEM COULD MAKE CONVECTION INTERESTING
THU OVERNIGHT. HOWEVER...COOLER TEMPERATURES/LOW MOISTURE RETURN
WOULD LIMIT THE OVERALL INSTABILITY. THE EXTENDED RANGE HAS BEEN
ANYTHING BUT CONSISTENT SO WILL CONTINUE TO MONITOR FOR NOW.
ANY AIRMASS MODIFICATION THAT MAY TAKE PLACE LOOKS MORE LIKELY
ACROSS THE SOUTH SO CONTINUE SCHC/CHC POPS TUE-TUE EVENING ACROSS
MAINLY THE TREASURE COAST/OKEECHOBEE COUNTY. THE MUCH COOLER AIR
BEHIND THE LATEST FRONT WILL CONTINUE IN PLACE INTO THE EXTENDED AS
FORECAST HIGHS/LOWS REMAIN WELL BELOW CLIMO THRU THU AND THEN CLOSER
TOWARDS NORMAL BY FRI.
&&
.AVIATION...
TAF SUITE SHOWS ALL TERMINALS BECOMING LIFR/VLIFR VV002-006
THROUGH 14Z WITH PATCHY DENSE FOG REDUCING VSBYS BELOW 1 MILE IN
SPOTS. LINGERING MVFR/IFR STRATUS FOR 2HRS OR SO THEREAFTER THEN
BECOMING VFR BY 17Z. MOST OF THE DAY SHOULD BE RAINFREE WITH A
CHANCE FOR SHOWERS AFT 21Z AT LEE SPREADING EAST TO MCO/DAB
THROUGH 02Z AND REMAINING TERMINALS THROUGH 06Z AND BEYOND. THREAT
FOR THUNDER LOOKS LOW BUT BEST CHANCE WILL BE LEE LATE IN THE DAY.
&&
.MARINE...
TODAY/TONIGHT...LOW PRESSURE IS FORECAST TO LIFT NE FROM THE
LOWER MS VALLEY AND STRENGTHEN AS IT REACHES THE EASTERN GREAT
LAKES TONIGHT. A WEAK INVERTED TROUGH ANALYZED JUST OFFSHORE THE
FL EAST COAST WILL PRODUCE A LIGHT NORTH FLOW ALONG THE COAST THIS
MORNING. BUT WINDS WILL SHIFT OUT OF THE S TO SW LATER THIS
MORNING AND AFTERNOON AS AN APPROACHING SYSTEM RAPIDLY MOVES EAST
FROM THE GULF OF MEXICO. WIND SPEEDS WILL BE AROUND 10 KNOTS THIS
AFTERNOON BUT INCREASE 15-20 KNOTS OFFSHORE TONIGHT AHEAD OF A
COLD FRONT. RAIN CHANCES LOOK QUITE LOW OVER THE ATLC WATERS
DURING THE DAY BUT FAST MOVING SHOWERS WILL APPROACH FROM THE WEST
BY EARLY EVENING INTO THE OVERNIGHT.
SUN-WED...THE LATEST WEATHER SYSTEM OVER THE CENTRAL PENINSULA EARLY
IN THE PERIOD WILL FINALLY CLEAR THE COASTAL WATERS BY LATE IN THE
DAY OR EARLY SUN EVENING. SCATTERED SHOWERS MAY CONTINUE IN THE
FORECAST SOUTH OF SEBASTIAN INLET ON SUN. CENTER OF HIGH PRESSURE
BUILDS INTO THE REGION SUN NIGHT THRU WED AND REMAINS NORTH OF THE
AREA. WE MAY SEE AN INTRO FOR SHOWERS BACK IN THE FORECAST MON
OVERNIGHT-TUE EVENING WITH SOME RETURN MOISTURE SOUTH OF SEBASTIAN
INLET.
WRLY WINDS BECOMING NWRLY ON SUN BEHIND THE FRONT WITH SPEEDS 14-
18KTS OVER THE OPEN ATLC. THE PRESSURE GRADIENT RELAXES ON MON AS
WINDS VEER MORE NORTHERLY AND SPEEDS DECREASE. WILL CONTINUE TO SEE
A N/NW WIND DIRECTION THROUGH THE EXTENDED. A PERSISTENT ENE LONG
PERIOD SWELL WILL KEEP SMALL CRAFT BOATING CONDITIONS POOR WITH
POTENTIAL HAZARDOUS CONDITIONS NEAR INLETS DURING THE OUTGOING TIDE.
THRU MON NIGHT SEAS WILL AVERAGE 5-6FT...POSSIBLY 7FT OFFSHORE/GULF
STREAM AND 3-5FT PERHAPS 4-6FT WITHIN 20NM OF THE COAST. LATE MON
NIGHT INTO WED MAY FINALLY SEE ANOTHER FOOT OR TWO DROP OFF OF THESE
WAVE HEIGHTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 78 62 73 43 / 30 40 10 0
MCO 80 64 77 45 / 30 40 10 0
MLB 80 66 79 46 / 20 40 20 0
VRB 81 66 80 49 / 20 40 30 10
LEE 79 63 73 44 / 40 40 10 0
SFB 80 63 74 44 / 30 40 10 0
ORL 81 65 75 48 / 30 40 10 0
FPR 81 66 80 49 / 20 40 30 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...KELLY
LONG TERM....SEDLOCK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
534 AM EST SAT JAN 9 2016
.SYNOPSIS...
ISSUED AT 1245 AM EST SAT JAN 9 2016
RAIN WILL MOVE BACK INTO THE AREA THIS AFTERNOON AND THEN
TRANSITION TO SNOW FROM WEST TO EAST THROUGH THE EVENING AND
OVERNIGHT HOURS. THE GREATEST POTENTIAL FOR HEAVY SNOW AND SEVERAL
INCHES OF ACCUMULATION REMAINS CLOSER TO LAKE MICHIGAN. FURTHER
EAST...AMOUNTS WILL BE LIGHTER BUT THEY WILL DEPEND ON THE TIMING
OF CHANGEOVER FROM RAIN TO SNOW. TEMPERATURES WILL FALL QUICKLY
TONIGHT LEADING TO A QUICK FREEZE OF WET SURFACES. WINDS WILL ALSO
INCREASE LATE TONIGHT INTO SUNDAY CREATING BLOWING AND DRIFTING
SNOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM EST SAT JAN 9 2016
OBVIOUS FOCUS FOR THIS SHORT TERM FORECAST IS TRANSITION FROM RAIN
TO SNOW LATE TODAY AND AMOUNTS. HAVE ISSUED WINTER STORM WARNING FOR
FAR NORTHWEST COUNTIES WITH WINTER WEATHER ADVISORY TO THE EAST OF
THE WARNING.
PHASING OF NORTHERN AND SOUTHERN STREAM SHORT WAVES TO TAKE PLACE
THIS PERIOD AND WATER VAPOR SHOWS THE TWO PLAYERS OF INTEREST
BEGINNING TO COME TOGETHER. NORTHERN STREAM WAVE IS DROPPING INTO
THE NORTHERN CONUS THIS MORNING WHILE SOUTHERN STREAM SYSTEM IS
BEGINNING TO LIFT OUT OF TEXAS. THIS WILL INITIALLY SPREAD RAIN
NORTHWARD ACROSS THE AREA THIS AFTERNOON. RAIN AND SNOW MIX EXPECTED
LATE AFTERNOON IN FAR NORTHWEST WHILE ALL RAIN CENTRAL AND EAST
UNTIL TONIGHT. SFC TEMPS INITIALLY ABOVE FREEZING SO LITTLE TO NO
ACCUMULATION EXPECTED UNTIL THIS EVENING.
MODELS IN RATHER GOOD AGREEMENT FOR COMPLEXITY OF PHASING WITH
PRIMARY DIFFERENCES BEING STRENGTH OF PHASED LOW AND HOW FAST COLD
AIR MOVES IN LOCALLY FOR CHANGEOVER TO SNOW LATE TODAY. 150+ KT 250-
300MB JET WILL DEVELOP TONIGHT FROM THE GULF COAST INTO THE TN
VALLEY REGION. LEFT EXIT REGION TO PROVIDE UPPER LEVEL DIFFLUENCE TO
AID IN DEEPENING SFC LOW WHICH SHOULD LIFT NORTHEAST FROM ARKANSAS
TO SOUTHERN INDIANA AND INTO NORTH CENTRAL OHIO BY SUNDAY MORNING.
MODEL CLUSTERS ARE RATHER TIGHT SO CONFIDENCE HIGH IN THIS GENERAL
TRACK.
THE PROBLEM LIES WITH HOW FAST LOW WILL DEEPEN AND HOW QUICK COLD
AIR WILL INFILTRATE CWA TO CHANGE PCPN OVER TO SNOW. NAM12 GENERALLY
THE QUICKEST WHILE MOST OTHER MODEL SOLUTIONS ARE SLOWER WITH THE
COLD AIR AND COMPLETE CHANGEOVER. TYPICALLY MODELS ARE TOO SLOW WITH
ARCTIC AIR INTRUSION AND 2M TEMPS UPSTREAM OVERNIGHT HAVE BEEN
LAGGING SFC OBS BY A FEW DEGREES SO GIVING SOME WEIGHT TO THE COLDER
NAM THERMAL PROFILES DESPITE ITS OVERALL WEAKER SOLUTION. WHILE
850MB TEMPS DROP BELOW 0C LATE THIS AFTERNOON...MOST MODELS KEEPING
A PBL MAX TEMP OF 3 TO 4C THROUGH 03Z IN THE NORTHWEST WITH SFC
TEMPS IN THE 33-36F RANGE. HAVE ADJUSTED THESE DOWN A COUPLE DEGREES
USING BLEND OF NAM AND GFS TO ALLOW FOR CHANGEOVER TO ALL SNOW
SHORTLY AFTER 00Z WITH DYNAMIC COOLING FROM STRONG LIFT IN
DEFORMATION ZONE AIDING IN CHANGEOVER. SFC TEMPS INITIALLY ABOVE
FREEZING AND WET GROUND FROM AFTERNOON RAIN MAY INHIBIT ACCUMS
INITIALLY UNTIL DEEPER COLD WEDGE ARRIVES IN THE NORTHWEST BY 03Z
WITH MODERATE SNOWFALL EXPECTED FOR SEVERAL HOURS OVERNIGHT.
USED A BLEND OF NAM12 AND GFS SNOW RATIOS IN TOP DOWN METHOD ALONG
WITH WPC QPF TO ARRIVE AT SNOWFALL AMOUNTS. AGAIN...TRICKY WITH PBL
TEMPS SO AMOUNTS COULD STILL VARY DEPENDING ON TIMING OF CHANGEOVER.
CONFIDENCE FOR WARNING AIDED BY EXPECTED LAKE ENHANCEMENT LATE
TONIGHT ALONG WITH STRONG WINDS AND FREEZING TEMPS MAKING FOR ICY
ROADS. THE BLEND YIELDED GENERAL AMOUNTS OF 4-7 INCHES IN THE FAR
NORTHWEST WHERE WARNING WAS ISSUED.
AWAY FROM THE WARNING...AMOUNTS OF 2 TO 5 EXPECTED WITH SIMILAR WIND
AND FREEZING ROAD CONCERNS SO ISSUED WINTER WEATHER ADVISORY. THIS
MAY NEED TO BE EXPANDED EAST FOR SUNDAY BUT WITH LESS AMOUNTS
GENERALLY EAST OF US 31 AND MORE IMPACTS IN THE LATE 2ND AND 3RD
PERIODS OPTED TO HOLD OFF ON SPREADING ADVISORY ANY FARTHER EAST.
CHANGEOVER TO SNOW WILL BE LATER TONIGHT AND LATEST GUIDANCE KEPT
EXTREME EASTERN COUNTIES AS RAIN TIL 12Z SUNDAY.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 529 AM EST SAT JAN 9 2016
TRANSITION TO ALL SNOW SHOULD BE COMPLETE AT THE START OF THE PERIOD
AS ARCTIC AIR POURS IN ON STRONG NW WINDS. LAKE ENHANCED SNOW
SHOWERS SHOULD PENETRATE WELL INLAND RESULTING NEED FOR INCREASE IN
POPS THROUGH THE DAY FURTHER EAST AND SOUTH. MOST LOCATIONS SHOULD
SEE ANYWHERE FROM A DUSTING TO UP TO AN INCH WITH LOCATIONS CLOSER
TO THE LAKE IN THE WARNING AREA POTENTIALLY SEEING LOCALLY MORE. THE
STRONG WINDS WILL ALLOW FOR EFFICIENT BLOWING AND DRIFTING OF THE
SNOW ALL DAY IN THE HEADLINE AREAS AND EXPANDING TO SOUTHEAST HALF
OR SO DURING THE AFTERNOON AS TEMPS FALL THROUGH THE 20S AND THE
SNOW BECOMES EASIER TO PICK UP. LATER SHIFTS MAY NEED TO EXPAND
ADVISORY FURTHER EAST THAN CURRENTLY IN PLACE DEPENDING ON FINAL
LAYOUT OF HEAVIEST SNOW...ADDITIONAL ACCUMULATIONS ON SUNDAY AND MAX
WIND SPEEDS.
LOW LEVEL FLOW WILL BRIEFLY BECOME WEST AND EVENTUALLY SOUTHWEST
SUNDAY NIGHT INTO MONDAY AHEAD OF THE NEXT SYSTEM..ALLOWING THE SNOW
SHOWERS TO SHIFT MORE INTO MI. CLIPPER SYSTEM WILL DROP INTO THE
AREA MONDAY NIGHT INTO TUESDAY AND BRING INCREASING CHANCES FOR
LIGHT SNOW TO THE AREA. LAKE EFFECT WILL BECOME RENEWED AS
COMBINATION OF EVEN COLDER AIR...INCREASE IN SYNOPTIC MOISTURE AND
INVERSION HEIGHTS AND MORE FAVORABLE FETCH ALL COMBINE.
THE CHANCE FOR SNOW SHOWERS WILL LINGER THROUGH THE REMAINDER OF THE
PERIOD AS COLD AIR CONTINUES TO REMAIN ENTRENCHED..ALTHOUGH SOME
MODERATION INTO THE MIDDLE AND UPPER 20S LOOKS POSSIBLE TOWARDS THE
END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1244 AM EST SAT JAN 9 2016
AVIATION FORECAST BECOMING TRICKY AS MIXING WITHIN WARM SECTOR HAS
ERODED LOW CIGS NEAR KFWA WHILE KSBN REMAINS CLOSER TO FRONTAL
BOUNDARY AND LIFR CONDITIONS. HIRES GUIDANCE DOES NOT HAVE A GOOD
HANDLE ON THESE CONDITIONS BUT HRRR IS TRENDING TOWARD MVFR AND
VFR AT KFWA WITH KSBN IN AND OUT OF THE LOW STRATUS. HAVE KEPT
KSBN IN THE LOWER CIGS WITH TRAJECTORIES SUGGESTING LOW CLOUDS MAY
NOT LIFT OUT. WITH VFR UPSTREAM OF KFWA HAVE BEEN A BIT MORE
OPTIMISTIC THERE. CONDITIONS DETERIORATE AGAIN SATURDAY AS NEXT
WAVE LIFTS NORTH AND FRONTAL BOUNDARY SAGS FURTHER EAST. PCPN TO
DEVELOP AFTER 20Z WITH KFWA LIKELY REMAINING RAIN UNTIL VERY END
OF PERIOD WHILE KSBN LIKELY STARTS AS A RAIN AND SNOW MIX WITH
QUICK TRANSITION TO ALL SNOW TOWARD 00Z AND VLIFR CONDITIONS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 7
PM EST /6 PM CST/ SUNDAY FOR INZ003-004.
WINTER WEATHER ADVISORY FROM 7 PM EST /6 PM CST/ THIS EVENING TO
7 PM EST /6 PM CST/ SUNDAY FOR INZ012>015-020-022.
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
SUNDAY FOR INZ005-006-016.
MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST SUNDAY
FOR MIZ077-078.
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
SUNDAY FOR MIZ079-080.
OH...NONE.
LM...GALE WARNING FROM 11 PM THIS EVENING TO 7 PM EST SUNDAY FOR
LMZ043-046.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
515 AM MST SAT JAN 9 2016
.UPDATE...
ISSUED AT 510 AM MST SAT JAN 9 2016
UPDATED TO ADD SLIGHT CHANCE POPS TO EASTERN CWA AND PATCHY FOG
TO EASTERN COLORADO. STRONGER RADAR RETURNS ARE EVIDENT AS BAND OF
SNOW DEVELOPED NEAR DEFORMATION ZONE ON NW SIDE OF UPPER LOW
CENTER. PROGRESSION OF UPPER LOW WILL CONTINUE TO BE TOWARDS THE
SOUTHEAST...HOWEVER THERE COULD BE STILL BE SEVERAL HOURS OF LIGHT
MEASURABLE SNOW (DUSTING) IN OUR EASTERN COUNTIES. OTHERWISE
FLURRIES/NON MEASURABLE SHOULD BE EXPECTED ACROSS REST OF CWA.
SHORT RANGE GUIDANCE STILL INDICATING POSSIBILITY FOR VIS TO DROP
TO ONE MILE OR LESS IN OUR FAR SOUTHEAST DUE TO FOG...THOUGH SO
FAR VIS HAS BEEN 3-6SM. ADDED PATCHY FOG MENTION IN COLORADO
COUNTIES TO ACCOUNT FOR POSSIBILITY.
&&
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 223 AM MST SAT JAN 9 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS A
LONGWAVE TROUGH ACROSS THE CENTRAL US ACROSS THE GLD CWA WITH A
CLOSED CENTER ROTATING OVER WESTERN OK TO THE SOUTHEAST. AN
AMPLIFIED RIDGE IN IN PLACE ACROSS THE WESTERN US UPSTREAM. AT THE
SURFACE CANADIAN HIGH PRESSURE EXTENDS SOUTH ACROSS THE NORTHERN
PLAINS ACROSS OUR CWA.
THIS MORNING-THIS AFTERNOON...WEAK FORCING BENEATH LONGWAVE TROUGH
HAS COMBINED WITH A SATURATED LAYER FROM 925-700 MB AND STEEP LOW
LOW LEVEL LAPSE RATES TO SUPPORT POCKETS OF FLURRIES ACROSS THE
AREA. AS THE CLOSED UPPER LOW TO THE SOUTHEAST MOVES EAST AND
SHORTWAVE RIDGING BUILDS INTO THE ROCKIES MUCH DRIER/STABLE AIR
SHOULD LEAD TO THIS ACTIVITY DISSIPATING. THERE COULD STILL BE A FEW
FLURRIES POSSIBLE THROUGH MIDDAY...HOWEVER OVERALL TREND SHOULD BE
FOR THIS TO END DURING THE MORNING HOURS. CAA WILL CONTINUE THIS
MORNING THROUGH THE AFTERNOON...AND IN LOCATIONS WITH PERSISTENT
CLOUD COVER WE COULD SEE HIGHS STRUGGLE TO REACH 20F. THERE IS SOME
INDICATION THAT WE COULD SEE BREAKS IN CLOUD COVER THIS
AFTERNOON...WHICH MAY ALLOW TEMPS (MAINLY SOUTH OF I-70) TO REACH
30F.
TONIGHT-MONDAY NIGHT...AMPLIFIED NW FLOW WILL BE IN PLACE ACROSS THE
PLAINS WITH MAIN STORM TRACK SPLIT AROUND OUR CWA. THERE WILL BE A
SERIES OF CLIPPERS ROTATING THROUGH THE MEAN FLOW...HOWEVER ANY
IMPACT ON SENSIBLE WEATHER OVER OUR CWA SHOULD BE LIMITED TO
INCREASES IN HIGH CLOUD COVER THROUGH THESE PERIODS.
REGARDING TEMPERATURES...THERE WILL BE A SLIGHT MODERATION IN THE
AIR MASS TONIGHT...HOWEVER WITH CANADIAN HIGH PRESSURE STILL BE A
STRONG INFLUENCE ON OUR TEMPS. THE QUESTION IS CLOUD COVER AND TDS AS
WITH CLEARING SKIES AND TDS ON DRIER END OF GUIDANCE COULD SUPPORT
LOWS NEAR ZERO AT SOME LOCATIONS. GUIDANCE SHOWS HIGH CLOUD COVER
INCREASING LATE WHICH LOWERS CONFIDENCE IN IDEAL RADIATIONAL
CONDITIONS. WEAK LEE TROUGH DEVELOPS IN EASTERN COLORADO/WYOMING
WITH DOWNSLOPE FLOW SUPPORTING CONTINUED MODERATION OF THE AIR MASS
THROUGH MONDAY. UPSTREAM SNOW FIELD AND PERIODS OF CLOUD COVER (AND
WINDS DURING THE NIGHT PERIODS) ALL LOWER CONFIDENCE IN TEMPS
THROUGH THE PERIODS. I STUCK WITH SIMILAR TRENDS AS PREVIOUS
FORECAST WITH HIGHS RETURNING TO SEASONAL VALUES AROUND 42 BY
MONDAY...AND OVERNIGHT LOWS IN THE SINGLE DIGITS (WEST) TO THE
TEENS(EAST). A QUICK MOVING SHORTWAVE TROUGH AND PASSING COLD FRONT
COMPLICATES LOWS MONDAY NIGHT...THOUGH WITH CAA IN PLACE EVEN CLOUD
COVER MAY NOT KEEP LOWS FROM DROPPING INTO THE TEENS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 117 AM MST SAT JAN 9 2016
MODELS CONTINUE TO NOT DO VERY WELL IN THIS TIME PERIOD. A LOT OF
SPREAD REMAINS NOT ONLY WITH THE DETERMINISTIC OUTPUT BUT ALSO THE
ENSEMBLES. MODELS DISAGREE ON HOW AMPLIFIED OR NOT THE FLOW IS WITH
THE OUTPUT OUT OF PHASE BY THE END OF THE PERIOD. ESSENTIALLY THE
FLOW REMAINS WEST TO NORTHWEST AND SOMETIMES EVEN MORE NORTH.
SO MOST OF THE WAVES GOING THROUGH LOOK TO BE OPEN AND FAST MOVING.
SO LITTLE TO NO CHANCE TO GET PRECIPITATION IN THIS SCENARIO. ONE OF
THOSE SHORTWAVES MOVES THROUGH IN THE THURSDAY TO FRIDAY TIME FRAME
AND BRINGS IN A MUCH COLDER AIR MASS. THE COMBINATION OF THE
SHORTWAVE AND COLD AIR ADVECTION SHOULD BE ABLE TO PRODUCE A SMALL
CHANCE OF LIGHT SNOW WHICH IS WHAT THE CRH_INIT GAVE ME FOR FRIDAY
WHICH IS REASONABLE.
WHAT LOOKS TO BE THE MOST UNCERTAIN IS THE TEMPERATURE FORECAST. IN
THIS FLOW COULD POSSIBLY GET A COLD SURGE/BACK DOOR COLD FRONT
MOVING INTO THE AREA. THE INIT GAVE ME WARMER TEMPERATURES IN THE
MIDDLE TO UPPER 40S ON WEDNESDAY AND THURSDAY...WHICH I WILL LEAVE
ALONE FOR NOW DUE TO MODEL DISAGREEMENT...BUT THERE IS DEFINITE
POTENTIAL FOR COLDER TEMPERATURES THOSE DAYS...DEPENDING OF COURSE
ON WHICH MODELS MID/UPPER SOLUTION WORKS OUT.
FRIDAY DEFINITELY LOOKS COLDER AND EVEN INTO THE REMAINDER OF NEXT
WEEKEND. THE PATTERN THE MODEL OUTPUT IS SHOWING...EVEN THOUGH
SHOWING DIFFERENCES...IS CONDUCIVE TO MUCH COLDER TEMPERATURES.
OVERALL NO CHANGES WILL BE MADE TO THE CRH_INIT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 414 AM MST SAT JAN 9 2016
POCKETS OF STRATUS (AROUND 1500 FT AGL)...FLURRIES...AND LIGHT
FOG (VIS 4-6SM) HAVE CONTINUED TO IMPACT PARTS OF EASTERN
COLORADO...NORTHWEST KANSAS...AND SOUTHWEST NEBRASKA AS INDICATED
BY AREA OBS/SATELLITE/RADAR. SHORT RANGE GUIDANCE SHOWS THIS
CONTINUING TO DISSIPATE AND RETREAT WESTWARD INTO EASTERN COLORADO.
IN THE EARLY PART OF THE TAF PERIOD I KEPT LOWER CONDITIONS AT
KGLD LINGERING INTO THE THE MID MORNING WITH QUICKER IMPROVEMENT
EXPECTED AT KMCK. THERE IS A CHANCE THESE CONDITIONS COULD LINGER
AT KGLD INTO THE EARLY AFTERNOON...BASED ON RAP RH VALUES. EVEN
IF CONDITIONS LINGER LONGER ALL GUIDANCE SUPPORTS VFR FROM THE
AFTERNOON THROUGH THE REMAINING TAF PERIOD. NW WINDS 10-12KT TODAY
SHOULD DECREASE AFTER 00Z WITH LIGHT AND VARIABLE WINDS DUE TO
HIGH PRESSURE SHIFTING SOUTH THROUGH THE REGION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
414 AM MST SAT JAN 9 2016
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 223 AM MST SAT JAN 9 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS A
LONGWAVE TROUGH ACROSS THE CENTRAL US ACROSS THE GLD CWA WITH A
CLOSED CENTER ROTATING OVER WESTERN OK TO THE SOUTHEAST. AN
AMPLIFIED RIDGE IN IN PLACE ACROSS THE WESTERN US UPSTREAM. AT THE
SURFACE CANADIAN HIGH PRESSURE EXTENDS SOUTH ACROSS THE NORTHERN
PLAINS ACROSS OUR CWA.
THIS MORNING-THIS AFTERNOON...WEAK FORCING BENEATH LONGWAVE TROUGH
HAS COMBINED WITH A SATURATED LAYER FROM 925-700 MB AND STEEP LOW
LOW LEVEL LAPSE RATES TO SUPPORT POCKETS OF FLURRIES ACROSS THE
AREA. AS THE CLOSED UPPER LOW TO THE SOUTHEAST MOVES EAST AND
SHORTWAVE RIDGING BUILDS INTO THE ROCKIES MUCH DRIER/STABLE AIR
SHOULD LEAD TO THIS ACTIVITY DISSIPATING. THERE COULD STILL BE A FEW
FLURRIES POSSIBLE THROUGH MIDDAY...HOWEVER OVERALL TREND SHOULD BE
FOR THIS TO END DURING THE MORNING HOURS. CAA WILL CONTINUE THIS
MORNING THROUGH THE AFTERNOON...AND IN LOCATIONS WITH PERSISTENT
CLOUD COVER WE COULD SEE HIGHS STRUGGLE TO REACH 20F. THERE IS SOME
INDICATION THAT WE COULD SEE BREAKS IN CLOUD COVER THIS
AFTERNOON...WHICH MAY ALLOW TEMPS (MAINLY SOUTH OF I-70) TO REACH
30F.
TONIGHT-MONDAY NIGHT...AMPLIFIED NW FLOW WILL BE IN PLACE ACROSS THE
PLAINS WITH MAIN STORM TRACK SPLIT AROUND OUR CWA. THERE WILL BE A
SERIES OF CLIPPERS ROTATING THROUGH THE MEAN FLOW...HOWEVER ANY
IMPACT ON SENSIBLE WEATHER OVER OUR CWA SHOULD BE LIMITED TO
INCREASES IN HIGH CLOUD COVER THROUGH THESE PERIODS.
REGARDING TEMPERATURES...THERE WILL BE A SLIGHT MODERATION IN THE
AIR MASS TONIGHT...HOWEVER WITH CANADIAN HIGH PRESSURE STILL BE A
STRONG INFLUENCE ON OUR TEMPS. THE QUESTION IS CLOUD COVER AND TDS AS
WITH CLEARING SKIES AND TDS ON DRIER END OF GUIDANCE COULD SUPPORT
LOWS NEAR ZERO AT SOME LOCATIONS. GUIDANCE SHOWS HIGH CLOUD COVER
INCREASING LATE WHICH LOWERS CONFIDENCE IN IDEAL RADIATIONAL
CONDITIONS. WEAK LEE TROUGH DEVELOPS IN EASTERN COLORADO/WYOMING
WITH DOWNSLOPE FLOW SUPPORTING CONTINUED MODERATION OF THE AIR MASS
THROUGH MONDAY. UPSTREAM SNOW FIELD AND PERIODS OF CLOUD COVER (AND
WINDS DURING THE NIGHT PERIODS) ALL LOWER CONFIDENCE IN TEMPS
THROUGH THE PERIODS. I STUCK WITH SIMILAR TRENDS AS PREVIOUS
FORECAST WITH HIGHS RETURNING TO SEASONAL VALUES AROUND 42 BY
MONDAY...AND OVERNIGHT LOWS IN THE SINGLE DIGITS (WEST) TO THE
TEENS(EAST). A QUICK MOVING SHORTWAVE TROUGH AND PASSING COLD FRONT
COMPLICATES LOWS MONDAY NIGHT...THOUGH WITH CAA IN PLACE EVEN CLOUD
COVER MAY NOT KEEP LOWS FROM DROPPING INTO THE TEENS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 117 AM MST SAT JAN 9 2016
MODELS CONTINUE TO NOT DO VERY WELL IN THIS TIME PERIOD. A LOT OF
SPREAD REMAINS NOT ONLY WITH THE DETERMINISTIC OUTPUT BUT ALSO THE
ENSEMBLES. MODELS DISAGREE ON HOW AMPLIFIED OR NOT THE FLOW IS WITH
THE OUTPUT OUT OF PHASE BY THE END OF THE PERIOD. ESSENTIALLY THE
FLOW REMAINS WEST TO NORTHWEST AND SOMETIMES EVEN MORE NORTH.
SO MOST OF THE WAVES GOING THROUGH LOOK TO BE OPEN AND FAST MOVING.
SO LITTLE TO NO CHANCE TO GET PRECIPITATION IN THIS SCENARIO. ONE OF
THOSE SHORTWAVES MOVES THROUGH IN THE THURSDAY TO FRIDAY TIME FRAME
AND BRINGS IN A MUCH COLDER AIR MASS. THE COMBINATION OF THE
SHORTWAVE AND COLD AIR ADVECTION SHOULD BE ABLE TO PRODUCE A SMALL
CHANCE OF LIGHT SNOW WHICH IS WHAT THE CRH_INIT GAVE ME FOR FRIDAY
WHICH IS REASONABLE.
WHAT LOOKS TO BE THE MOST UNCERTAIN IS THE TEMPERATURE FORECAST. IN
THIS FLOW COULD POSSIBLY GET A COLD SURGE/BACK DOOR COLD FRONT
MOVING INTO THE AREA. THE INIT GAVE ME WARMER TEMPERATURES IN THE
MIDDLE TO UPPER 40S ON WEDNESDAY AND THURSDAY...WHICH I WILL LEAVE
ALONE FOR NOW DUE TO MODEL DISAGREEMENT...BUT THERE IS DEFINITE
POTENTIAL FOR COLDER TEMPERATURES THOSE DAYS...DEPENDING OF COURSE
ON WHICH MODELS MID/UPPER SOLUTION WORKS OUT.
FRIDAY DEFINITELY LOOKS COLDER AND EVEN INTO THE REMAINDER OF NEXT
WEEKEND. THE PATTERN THE MODEL OUTPUT IS SHOWING...EVEN THOUGH
SHOWING DIFFERENCES...IS CONDUCIVE TO MUCH COLDER TEMPERATURES.
OVERALL NO CHANGES WILL BE MADE TO THE CRH_INIT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 414 AM MST SAT JAN 9 2016
POCKETS OF STRATUS (AROUND 1500 FT AGL)...FLURRIES...AND LIGHT
FOG (VIS 4-6SM) HAVE CONTINUED TO IMPACT PARTS OF EASTERN
COLORADO...NORTHWEST KANSAS...AND SOUTHWEST NEBRASKA AS INDICATED
BY AREA OBS/SATELLITE/RADAR. SHORT RANGE GUIDANCE SHOWS THIS
CONTINUING TO DISSIPATE AND RETREAT WESTWARD INTO EASTERN COLORADO.
IN THE EARLY PART OF THE TAF PERIOD I KEPT LOWER CONDITIONS AT
KGLD LINGERING INTO THE THE MID MORNING WITH QUICKER IMPROVEMENT
EXPECTED AT KMCK. THERE IS A CHANCE THESE CONDITIONS COULD LINGER
AT KGLD INTO THE EARLY AFTERNOON...BASED ON RAP RH VALUES. EVEN
IF CONDITIONS LINGER LONGER ALL GUIDANCE SUPPORTS VFR FROM THE
AFTERNOON THROUGH THE REMAINING TAF PERIOD. NW WINDS 10-12KT TODAY
SHOULD DECREASE AFTER 00Z WITH LIGHT AND VARIABLE WINDS DUE TO
HIGH PRESSURE SHIFTING SOUTH THROUGH THE REGION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
653 AM CST SAT JAN 9 2016
...SOUNDING DISCUSSION...
BALLOON WAS RELEASED SHORTLY BEFORE THE RAIN BEGAN AT THE OFFICE.
THERE WAS QUITE A BIT OF DRY AIR FROM ABOUT 1000 TO 10000
FEET WITH A PRECIPITABLE WATER VALUE A LITTLE OVER AN INCH. A
TEMPERATURE INVERSION EXTENDED TO ABOUT 900 FEET. WITH THE
SURFACE BOUNDARY AROUND THE LOUISIANA COAST...STORMS ACROSS MUCH
OF THE AREA HAVE BEEN MOSTLY ELEVATED...ESPECIALLY NORTH OF THE
TIDAL LAKES. A FEW STRONGER STORMS WERE ABLE TO PRODUCE HAIL
EARLIER IN THE NIGHT AND THE CURRENT FREEZING LEVEL AT ABOUT 8200
FEET. THE WIND PROFILE IS FAIRLY IMPRESSIVE WITH A NICE VEERING
WIND PROFILE AND GOOD SPEED SHEAR WITH THE CORE OF THE JET OVER
THE NORTHERN GULF OF MEXICO. PEAK WINDS SAMPLED BY THE SONDE WERE
133 KNOTS AT 39700 FEET.
12Z BALLOON INFO: NO ISSUES WITH THE FLIGHT THAT LASTED 83 MINUTES
AND BURST NEAR VANCLEAVE AT A HEIGHT OF 19.2 MILES ABOVE THE
GROUND 66 MILES DOWNRANGE FROM THE OFFICE.
ANSORGE
&&
.PREV DISCUSSION... /ISSUED 430 AM CST SAT JAN 9 2016/
SHORT TERM.. WIDE SWATH OF SHOWERS AND SCATTERED THUNDERSTORMS ARE
MOVING ACROSS THE CWA THIS MORNING. INTENSITY OF STORMS HAS DROPPED
OFF CONSIDERABLY HAS CONVECTION HAS MOVED INTO THE FORECAST AREA.
THIS ISN/T MUCH OF A SURPRISE BASED ON THE LOCAL 00Z SOUNDING WHICH
SHOWS STRONG WARM NOSE WHICH IS SEVERELY LIMITING INSTABILITY. DOWN
ON THE COAST...SFC TEMPS ARE SIGNIFICANTLY WARMER IN THE 60S AND 70S
OFFSHORE. IN THOSE AREAS (SOUTH OF I-10) SHOULD STILL HAVE ELEVATED
THUNDERSTORMS WITH ISOLATED STORMS CAPABLE OF PRODUCING SMALL HAIL.
FOR THE OFFSHORE WATERS COULD HAVE SOME SFC BASED CELLS WHICH COULD
LEAD TO A FEW WATERSPOUTS. THE FURTHER EAST CONVECTION MOVES ACROSS
LAND THE MORE IN TRACKS INTO LESS CONDUCIVE CONDITIONS. THE HRRR HAS
PERFORMED EXTREMELY WELL AND FEEL CONFIDENT THE OUTPUT OVER THE NEXT
SEVERAL HOURS IS A PRETTY GOOD REPRESENTATION OF WHAT TO EXPECT.
THAT WOULD BE STRONG STORMS OFFSHORE MOVING EAST...SCATTERED STORMS
SOUTH OF NEW ORLEANS AND MOSTLY RAIN NORTH OF THERE AS IT ALL SHIFTS
ACROSS THE CWA. THE BACK EDGE OF THIS RAINFALL SHOULD EXIT THE MS
COAST BY AROUND NOON TO SLIGHTLY SOONER. WRAP AROUND MOISTURE
ASSOCIATED WITH THE UPPER LOW COULD SPARK OFF SOME LINGERING SHOWERS
THIS AFTERNOON BUT NOT EXPECTING TOO MUCH IN THE WAY OF COVERAGE OR
INTENSITIES.
THE REMAINDER OF THE WEEKEND LOOKS QUIET AS STRONG SURFACE RIDGE
BUILDS IN ON SUNDAY. WILL HAVE A 15 TO 20 DEGREE DROP IN HIGHS.
STRONG CAA OCCURRING TOMORROW NIGHT. THIS WILL LEAD TO POSSIBLY THE
COLDEST TEMPERATURES OF THIS WINTER SEASON. DROPPED LOWS BY A COUPLE
DEGREES IN SOME LOCATIONS...BASICALLY SPLITTING MAV/MET FCST LOWS.
TEMPS WOULD RANGE FROM MID 20S TO LOWER 30S.
LONG TERM... BROAD UPPER TROUGH WILL TRACK ACROSS THE EASTERN HALF
OF THE COUNTRY. THIS WILL KEEP COLD AIR MAKING IT ACTUALLY FEEL LIKE
WINTER DOWN ALONG THE GULF COAST THROUGH TUESDAY. HIGHS MONDAY MAY
NOT EVEN BREAK THE 40S FOR MANY LOCATIONS. CLEAR SKIES...LIGHT WINDS
WITH HIGH PRESSURE SITTING RIGHT OVER THE REGION. AFTER TUE MORNING
THE REGION STARTS TO MODERATE WITH THE NEXT SYSTEM NOT ANTICIPATED
TO IMPACT THE REGION TILL THE LATTER HALF OF THE WEEK
MEFFER
AVIATION... VISIBILITIES HAVE RISE CONSIDERABLY IN THE LAST FEW
HOURS AS WIDE SWATH OF RAIN PROGRESSES ACROSS THE AREA.
HOWEVER...LIFR/IFR CEILINGS PERSIST AND INTERMITTENT HEAVY RAINFALL.
THE BULK OF HEAVY RAIN IS RACING EAST AND SHOULD BE EAST OF ALL
TERMINALS BY NOON WITH LINGERING SHOWERS DURING THE AFTERNOON HOURS.
CLEAR SKIES NOT EXPECTED UNTIL BEYOND THE TAF PERIOD.
MARINE... LATEST SFC ANALYSIS SHOWS TROUGH TRACKING EAST ACROSS
LOUISIANA WITH LOW CENTER IN ARKANSAS. FRONTAL BOUNDARY EXPECTED TO
MOVE ACROSS THE COASTAL WATERS THIS AFTERNOON AND CONTINUE WELL
SOUTH ACROSS THE ENTIRE GULF OF MEXICO. LATEST OBSERVED WINDS
OFFSHORE HOVERING NEAR EXERCISE CAUTION. LIKELY TO GET WIND
ENHANCEMENT WITH AREA OF SHOWERS AND STORMS MOVING ACROSS AND
DEFINITELY COULD BE SOME WATERSPOUTS WITH STRONGER CELLS. IN
ADDITION...WINDS TO SHIFT FROM SOUTHEAST THIS MORNING TO A MORE
WESTERLY AND THEN NORTHWESTERLY DIRECTION BY THE AFTN HOURS. SMALL
CRAFT ADVISORY GOING OUT THIS FCST PACKAGE STARTING AT 21Z FOR ALL
COASTAL WATERS AND CONTINUING THRU 15Z SUNDAY. NEARSHORE AND TIDAL
LAKES WILL BE THE FIRST TO DROP DOWN AS PRESSURE GRADIENT WEAKENS
WITH SFC RIDGE CLOSE IN ON THE AREA. HIGH PRESSURE WILL THEN SETTLE
OVER THE AREA SUNDAY NIGHT AND MONDAY...WITH NORTHERLY WINDS FALLING
TO BETWEEN 10 AND 15 KNOTS. THESE WINDS WILL GRADUALLY TURN MORE
EASTERLY BY TUESDAY.
MEFFER
DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...ONGOING FLOODING ON MISSISSIPPI RIVER
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 68 37 47 25 / 50 10 0 0
BTR 70 40 49 28 / 40 10 10 0
ASD 70 43 51 28 / 80 10 0 0
MSY 71 44 50 33 / 70 10 0 0
GPT 70 42 52 28 / 80 10 0 0
PQL 73 43 53 26 / 80 10 0 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM CST SUNDAY
FOR GMZ530-532-534-536-538-550-552-555-557-570-572-575-577.
MS...NONE.
GM...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM CST SUNDAY
FOR GMZ532-534-536-538-550-552-555-557-570-572-575-577.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
430 AM CST SAT JAN 9 2016
.SHORT TERM.. WIDE SWATH OF SHOWERS AND SCATTERED THUNDERSTORMS ARE
MOVING ACROSS THE CWA THIS MORNING. INTENSITY OF STORMS HAS DROPPED
OFF CONSIDERABLY HAS CONVECTION HAS MOVED INTO THE FORECAST AREA.
THIS ISN/T MUCH OF A SURPRISE BASED ON THE LOCAL 00Z SOUNDING WHICH
SHOWS STRONG WARM NOSE WHICH IS SEVERELY LIMITING INSTABILITY. DOWN
ON THE COAST...SFC TEMPS ARE SIGNIFICANTLY WARMER IN THE 60S AND 70S
OFFSHORE. IN THOSE AREAS (SOUTH OF I-10) SHOULD STILL HAVE ELEVATED
THUNDERSTORMS WITH ISOLATED STORMS CAPABLE OF PRODUCING SMALL HAIL.
FOR THE OFFSHORE WATERS COULD HAVE SOME SFC BASED CELLS WHICH COULD
LEAD TO A FEW WATERSPOUTS. THE FURTHER EAST CONVECTION MOVES ACROSS
LAND THE MORE IN TRACKS INTO LESS CONDUCIVE CONDITIONS. THE HRRR HAS
PERFORMED EXTREMELY WELL AND FEEL CONFIDENT THE OUTPUT OVER THE NEXT
SEVERAL HOURS IS A PRETTY GOOD REPRESENTATION OF WHAT TO EXPECT.
THAT WOULD BE STRONG STORMS OFFSHORE MOVING EAST...SCATTERED STORMS
SOUTH OF NEW ORLEANS AND MOSTLY RAIN NORTH OF THERE AS IT ALL SHIFTS
ACROSS THE CWA. THE BACK EDGE OF THIS RAINFALL SHOULD EXIT THE MS
COAST BY AROUND NOON TO SLIGHTLY SOONER. WRAP AROUND MOISTURE
ASSOCIATED WITH THE UPPER LOW COULD SPARK OFF SOME LINGERING SHOWERS
THIS AFTERNOON BUT NOT EXPECTING TOO MUCH IN THE WAY OF COVERAGE OR
INTENSITIES.
THE REMAINDER OF THE WEEKEND LOOKS QUIET AS STRONG SURFACE RIDGE
BUILDS IN ON SUNDAY. WILL HAVE A 15 TO 20 DEGREE DROP IN HIGHS.
STRONG CAA OCCURRING TOMORROW NIGHT. THIS WILL LEAD TO POSSIBLY THE
COLDEST TEMPERATURES OF THIS WINTER SEASON. DROPPED LOWS BY A COUPLE
DEGREES IN SOME LOCATIONS...BASICALLY SPLITTING MAV/MET FCST LOWS.
TEMPS WOULD RANGE FROM MID 20S TO LOWER 30S.
.LONG TERM... BROAD UPPER TROUGH WILL TRACK ACROSS THE EASTERN HALF
OF THE COUNTRY. THIS WILL KEEP COLD AIR MAKING IT ACTUALLY FEEL LIKE
WINTER DOWN ALONG THE GULF COAST THROUGH TUESDAY. HIGHS MONDAY MAY
NOT EVEN BREAK THE 40S FOR MANY LOCATIONS. CLEAR SKIES...LIGHT WINDS
WITH HIGH PRESSURE SITTING RIGHT OVER THE REGION. AFTER TUE MORNING
THE REGION STARTS TO MODERATE WITH THE NEXT SYSTEM NOT ANTICIPATED
TO IMPACT THE REGION TILL THE LATTER HALF OF THE WEEK
MEFFER
&&
.AVIATION... VISIBILITIES HAVE RISE CONSIDERABLY IN THE LAST FEW
HOURS AS WIDE SWATH OF RAIN PROGRESSES ACROSS THE AREA.
HOWEVER...LIFR/IFR CEILINGS PERSIST AND INTERMITTENT HEAVY RAINFALL.
THE BULK OF HEAVY RAIN IS RACING EAST AND SHOULD BE EAST OF ALL
TERMINALS BY NOON WITH LINGERING SHOWERS DURING THE AFTERNOON HOURS.
CLEAR SKIES NOT EXPECTED UNTIL BEYOND THE TAF PERIOD.
&&
.MARINE... LATEST SFC ANALYSIS SHOWS TROUGH TRACKING EAST ACROSS
LOUISIANA WITH LOW CENTER IN ARKANSAS. FRONTAL BOUNDARY EXPECTED TO
MOVE ACROSS THE COASTAL WATERS THIS AFTERNOON AND CONTINUE WELL
SOUTH ACROSS THE ENTIRE GULF OF MEXICO. LATEST OBSERVED WINDS
OFFSHORE HOVERING NEAR EXERCISE CAUTION. LIKELY TO GET WIND
ENHANCEMENT WITH AREA OF SHOWERS AND STORMS MOVING ACROSS AND
DEFINITELY COULD BE SOME WATERSPOUTS WITH STRONGER CELLS. IN
ADDITION...WINDS TO SHIFT FROM SOUTHEAST THIS MORNING TO A MORE
WESTERLY AND THEN NORTHWESTERLY DIRECTION BY THE AFTN HOURS. SMALL
CRAFT ADVISORY GOING OUT THIS FCST PACKAGE STARTING AT 21Z FOR ALL
COASTAL WATERS AND CONTINUING THRU 15Z SUNDAY. NEARSHORE AND TIDAL
LAKES WILL BE THE FIRST TO DROP DOWN AS PRESSURE GRADIENT WEAKENS
WITH SFC RIDGE CLOSE IN ON THE AREA. HIGH PRESSURE WILL THEN SETTLE
OVER THE AREA SUNDAY NIGHT AND MONDAY...WITH NORTHERLY WINDS FALLING
TO BETWEEN 10 AND 15 KNOTS. THESE WINDS WILL GRADUALLY TURN MORE
EASTERLY BY TUESDAY.
MEFFER
&&
.DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...ONGOING FLOODING OF PEARL AND MISSISSIPPI RIVERS
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 67 37 47 25 / 50 10 0 0
BTR 70 40 49 28 / 40 10 10 0
ASD 71 43 51 28 / 80 10 0 0
MSY 71 44 50 33 / 70 10 0 0
GPT 70 42 52 28 / 80 10 0 0
PQL 73 43 53 26 / 80 10 0 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM CST SUNDAY
FOR GMZ530-532-534-536-538-550-552-555-557-570-572-575-577.
MS...NONE.
GM...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM CST SUNDAY
FOR GMZ532-534-536-538-550-552-555-557-570-572-575-577.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
701 AM EST SAT JAN 9 2016
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 254 AM EST SAT JAN 9 2016
A WINTER STORM WILL AFFECT THE REGION AS RAIN CHANGES TO SNOW THIS
EVENING AND OVERNIGHT. A RAPID FALL IN TEMPERATURES WILL CAUSE A
QUICK FREEZE UP ON AREA ROADS THIS EVENING. AREAS NORTH AND WEST OF
GRAND RAPIDS CAN EXPECT 4 TO 8 INCHES OF SNOW...WHILE AREAS SOUTH
AND EAST OF GRAND RAPIDS WILL SEE 1 TO 5 INCHES OF SNOW. ALONG WITH
THE SNOW...WINDS WILL INCREASE LATE SATURDAY NIGHT AND CONTINUE INTO
SUNDAY. NORTHWEST WINDS WILL GUST TO 30-35 MPH CAUSING BLOWING AND
DRIFTING SNOW.
ANOTHER ROUND OF ACCUMULATING SNOW APPEARS LIKELY MONDAY NIGHT INTO
TUESDAY NIGHT. IT SHOULD REMAIN COLD ALL NEXT WEEK WITH DAYTIME
HIGHS ONLY 20 TO 25.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 254 AM EST SAT JAN 9 2016
WILL ISSUE A WINTER STORM WARNING FOR THE NW HALF OF THE CWA FOR
TONIGHT AND SUNDAY. THIS WILL BE BORDERED BY AN ADVISORY TO IT/S SE.
POTENT LOW PRESSURE REMAINS ON TRACK TO IMPACT MUCH OF LOWER
MICHIGAN. CONFIDENCE REMAINS HIGH AS THE MODELS HAVE STUCK TO A
VERY SIMILAR SOLUTION FOR THE PAST 24-36 HOURS. THE STORM PATH
REMAINS INTACT...ALTHOUGH IT APPEARS SLIGHT QUICKER...REACHING JUST
WEST OF ERIE PA BY 12 SUNDAY.
THE KEY ELEMENT TO THE FORECAST WILL BE THE TEMP TREND. MODELS
SEEMS TOO WARM AS THE PCPN SETTLES IN LATE THIS AFTERNOON. UPSTREAM
OBS BACK THIS UP. IF THIS HOLDS WE WILL SEE A QUICKER CHANGE OVER
TO SNOW...AND THEREFORE HIGHER SNOW TOTALS. I BELIEVE THIS COOLER
TREND WILL HOLD FOR THE NW CWA...HOWEVER IT APPEARS THE SE WILL
STRUGGLE TO COOL AS THE SYSTEM BRINGS A SURGE OF WARM GULF AIR
THERE. SO EXPECT WE WILLS SEE A SHARP SNOW TOTALS ALONG A LINE FROM
ROUGHLY ALMA TO SOUTH HAVEN. NW OF THIS LINE THE PCPN TYPE BY EARLY
THIS EVENING SHOULD BE MAINLY SNOW...WHILE AREAS SE OF THE LINE ONLY
CHANGE OVER THROUGH TONIGHT. THEREFORE WILL ISSUE A WINTER STORM
WARNING FOR AREAS NW OF THE LINE...AN ADVISORY TO THE SE.
5TO8INCHESIN THE WARNING...3-5 IN THE ADVISORY. I WILL EXCLUDE
CALHOUN...INGHAM AND JACKSON COUNTIES WHERE ONLY 1-3 INCHES IS
EXPECTED.
THE QUICK FREEZE UP WILL BE A FACTOR IN THIS STORM CAUSING ROADS TO
ICE UP AS THE SNOW BEGINS. THE WINDS WILL BECOME A FACTOR AND IS
REALLY WHAT PUSHES THIS STORM INTO THE WARNING CATEGORY. GUST WILL
FREQUENTLY BE IN THE 30-35 MPH RANGE...AND EVEN A BIT HIGHER ALONG
THE COAST. THIS WILL CAUSE BLOWING AND DRIFTING SNOW...ESPECIALLY
AS TEMPS GET COLDER AND THE SNOW GET FLUFFIER. THE ABRUPT CHANGE IN
THE AREA/S CONDITIONS WAS ALSO A CONSIDERING FACTOR WITH THE
HEADLINES DECISIONS.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 254 AM EST SAT JAN 9 2016
AFTER 5 MONTHS OF UNUSUALLY WARM TEMPERATURES AND VERY LITTLE IN THE
WAY OF PERSISTENT COLD WEATHER... WE ARE IN FOR A MAJOR PATTERN
CHANGE. THIS WILL MEAN PERSISTENT LAKE EFFECT SNOW AND BELOW NORMAL
TEMPERATURES MOST OF THIS WEEK AND LIKELY BEYOND THAT. THE DAYS WITH
THE STRONGEST WINDS AND GREATEST LAKE EFFECT SNOW POTENTIAL ARE
TUESDAY THEN LATE WEDNESDAY INTO THURSDAY.
THANKS TO MASSIVE UPPER LEVEL BLOCKING WITH A CLOSED UPPER LEVEL
HIGH NORTH OF ALASKA AND A RIDGE (FORCED BY THE MJO BEING IN PHASE
8) ALONG THE WEST COAST WE WILL CONTINUE TO SEE THE NORTHERN STREAM
IMPACTING OUR WEATHER MOST OF THIS WEEK INTO NEXT WEEKEND. ACTUALLY
BY THURSDAY WE HAVE REX BLOCK OVER EASTERN NORTH AMERICA WITH AN
UPPER LEVEL HIGH OVER BAFFIN`S ISLAND AND ELONGATED CLOSED UPPER LOW
CENTERED OVER EASTERN CANADA. MEANWHILE THE WEST COAST RIDGE
PERSISTENT. SO WHAT WE WILL SEE IS A SERIES OF SHORTWAVES ROTATING
AROUND THE CANADIAN UPPER LOW THROUGH THIS WEEK THROUGH THIS COMING
WEEKEND. AS EACH COMES THROUGH THE INVERSION HEIGHT RISES AND LAKE
EFFECT SNOW WILL RAMP UP. THE FIRST OF THESE COMES THROUGH TUESDAY
MORNING THEN THE NEXT ONE IS WEDNESDAY NIGHT INTO THURSDAY MORNING.
AS THE SHORTWAVE THAT COMES FROM NORTH OF ALASKA (THIS MORNING)
DROPS INTO THE MEAN TROUGH IT HELPS CLOSE OFF AN UPPER LOW OVER
MICHIGAN BY TUESDAY EVENING. THAT RESULTS IN INVERSION HEIGHTS RISE
ABOVE 10000 FT TUESDAY MORNING AND THERE IS STRONG LIFT IN THE DGZ.
THIS WILL START AS SOUTHWEST FLOW EVENT AND TRANSITION INTO A WEST
FLOW EVENT TUESDAY DURING THE DAY. IT WILL BE WINDY IN THE AFTERNOON
WITH GUSTS TO 30 MPH MORE THAN POSSIBLE DUE TO THE SHIFTING SNOW
BANDS THE HEAVIEST SNOW WILL BE SOMEWHAT SPREAD OUT BUT THANKS TO
THE WEST WINDS DURING THE DAY TUESDAY THE BAND WILL STREAM INLAND
BETWEEN I-94 AND I-96. THE CIPS ANALOGS SHOW AT GREATER THAN 80 PCT
CHANCE OF MORE THAN 6 INCHES OF SNOW WEST OF US-131 FOR THIS EVENT.
THE NEXT SYSTEM THAT COMES THROUGH WEDNESDAY NIGHT INTO THURSDAY IS
NOT AS IMPRESSIVE BUT EVEN SO WE ARE STILL IN THE COLD AIR AND GFS
AND ECMWF ARE SHOWING GOOD LIFT AS THIS WAVE PASSES THROUGH. THIS
ONE SEEMS TO IMPACT THE SOUTHERN SECTIONS MORE THAN THE NORTHERN
ONES. EVEN SO... THE LAKE EFFECT SNOW WILL CONTINUE.
BEYOND THURSDAY THERE IS MODEL DISAGREEMENT AS TO HOW THE CANADIAN
UPPER LOW WOBBLES AROUND. THE ECMWF ROTATES ANOTHER CLOSED UPPER LOW
THOUGH THE AREA FRIDAY WHILE THE GFS HAS THAT SYSTEM STALLED OVER
NORTH DAKOTAS. WE WILL HAVE TO SEE LATER MODEL RUNS TO RESOLVE THAT
BUT ONE WAY OR THE OTHER IT WILL REMAIN COLDER THAN NORMAL AND
SIGNIFICANT SNOWFALL AMOUNTS SHOULD BE EXPECTED NEAR AND WEST OF US-
131 MONDAY AFTERNOON THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 700 AM EST SAT JAN 9 2016
I SEE TWO MAJOR AVIATION ISSUES TODAY. FIRST IS DENSE FOG. THEN WE
HAVE THE ISSUE OF RAIN CHANGING TO SNOW AND BLOWING SNOW WITH THE SYSTEM
TONIGHT INTO SUNDAY.
THE FOG HAS BEEN IN AND OUT OVERNIGHT (MOSTLY AT GRR)HOWEVER WE
CURRENTLY REMAIN IN THE CIRCULATION OF THE DEPARTING SURFACE LOW.
ONCE THAT SYSTEM LIFTS OUT OF THE AREA... AROUND 15Z OR SO...
WINDS WILL BECOME LIGHT AND VARIABLE AND I DO BELIEVE WE WILL SEE
THE FOG REALLY SET IN AND MOST OF OUR TAF SITES WILL SEE 1/2SM FG
FOR SEVERAL HOURS (SEEN ON THE RAP MODEL VISIBILITY FORECAST RUN
AFTER RUN OVERNIGHT).
BY 21Z OR SO THE DEVELOPING STORM TO OUR SOUTH WILL BE CLOSE
ENOUGH TO PUT US IN THE CIRCULATION OF THAT SYSTEM. THAT WILL
START THE RAIN AND INCREASE THE WIND...ENDING THE FOG. WE SHOULD
SEE ABOUT 12 HOURS OF MODERATE TO HEAVY PRECIPITATION AS THE
DEFORMATION ZONE OF THE SYSTEM PASSES OVERHEAD. THE HEAVIEST QPF
WILL BE JUST ON A LINE FROM SBN TO MOP. MEANWHILE THE RAIN/SNOW
LINE WILL MOVE EASTWARD...CHANGING THE RAIN TO SNOW AT MKG AND GRR BY
00Z...BUT IT MAY TAKE TILL 10Z FOR THAT RAIN TO SNOW LINE TO REACH
JXN. THIS IS SHOWN BY THE NUMEROUS RUNS OF THE RAP...HRRR...AND
GFS MODELS (ECMWF FOR THAT MATTER TOO). AS THE LOW DEEPENS WINDS
WILL INCREASE OUT OF THE NORTH AND WITH TEMPERATURES FALLING INTO
THE 20S BY 09Z OR SO... I WOULD EXPECT CONSIDERABLE BLOWING SNOW
TOO.
BOTTOM LINE...IFR /LIFR FOG THIS AFTERNOON.... THEN IFR RAIN TO
SNOW TONIGHT.
&&
.MARINE...
ISSUED AT 254 AM EST SAT JAN 9 2016
GALE WARNING HAS BEEN ISSUED AS WINDS RAMP UP QUICKLY LATE TONIGHT.
THE WINDS SHOULD SIMMER DOWN A BIT BY LATE SUNDAY EVENING AS THE
STORM PULLS AWAY.
&&
.HYDROLOGY...
ISSUED AT 134 PM EST FRI JAN 8 2016
THERE IS INCREASING CONCERN FOR MINOR RIVER FLOODING HEADING
THROUGH THE NEXT SEVERAL DAYS. RIVER RISES ARE LIKELY WITH A FEW
LOCATIONS THAT HAVE THE POTENTIAL TO REACH BANKFULL. THE MAIN
QUESTIONS TO BE ANSWERED HAVE TO DEAL WITH THE AMOUNT OF RUNOFF
DUE TO SNOWMELT AND RESULTING LIQUID PRECIPITATION THROUGH LATE
SATURDAY EVENING.
THE FIRST WAVE OF MOISTURE WILL MOVE THROUGH AHEAD OF A STORM
SYSTEM CURRENTLY OVER MISSOURI/ILLINOIS. RAINFALL POTENTIAL EXISTS
NOW THROUGH MUCH OF SATURDAY. THE KEY TO HOW QUICKLY RIVERS
RESPOND LIES IN THE DETAILS OF REALIZED TOTALS...LEADING UP TO THE
THE TRANSITION TO SNOW SATURDAY NIGHT. ONCE COLDER AIR MOVES IN
LATE SATURDAY INTO SUNDAY...SUB-FREEZING TEMPS MAY BRING A HALT TO
MUCH OF THE RUNOFF AS POTENTIAL RUNOFF FREEZES. PRECIPITATION IS
THEN EXPECTED TO REMAIN LARGELY LOCKED UP IN SNOW ACCUMULATIONS.
THE WEEK AHEAD WILL BRING ADDITIONAL SNOW ACCUMULATIONS...BUT
TEMPERATURES SHOULD BE WELL BELOW FREEZING THROUGH THURSDAY.
CONDITIONS WILL NEED TO BE MONITORED THROUGH THE NEXT FEW DAYS FOR
ANY RISES THAT HAVE THE POTENTIAL TO EXCEED BANKFULL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST SUNDAY
FOR MIZ037>040-043>046-050-051-056-057-064-071.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
SUNDAY FOR MIZ052-058-059-065-066-072.
LM...GALE WARNING FROM 1 AM TO 7 PM EST SUNDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JAM
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
645 AM EST SAT JAN 9 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 407 AM EST SAT JAN 9 2016
MUCH COLDER AIR WILL BEGIN SURGING INTO THE AREA TODAY AND LEAD TO
BELOW NORMAL TEMPERATURES (WITH LAKE EFFECT SNOW) THROUGH AT LEAST
THE MIDDLE OF THE UPCOMING WORK WEEK. THE COLD AIR IS NOW STARTING
TO MOVE INTO THE WESTERN U.P. (RAP ANALYSIS SHOWING 850MB TEMPS
AROUND -7C AND -12C UPSTREAM IN THE MINNESOTA ARROWHEAD) AND THAT
WILL CONTINUE ACROSS THE AREA TODAY. BEFORE THAT OCCURS...A SURFACE
LOW IS CURRENTLY LOCATED OVER THE EASTERN U.P. AND IS CONTINUING TO
PRODUCE PRECIPITATION AS A SHORTWAVE LIFTS NORTHEAST THROUGH THE
AREA. WHILE MUCH OF THE PRECIPITATION OVER THE EASTERN U.P. FELL AS
RAIN THROUGH THE EVENING...HAVE BEEN SEEING A TRANSITION TO SNOW NOW
AS THE COLDER AIR IS STARTING TO WORK INTO THAT AREA (3AM METARS
SHOW KISQ IS THE ONLY SITE HANGING ON TO RAIN). EVENING SHIFT
FOLLOWED THE WETBULB0 HEIGHTS FROM THE RAP FOR THE RAIN/SNOW
TRANSITION AND THAT STILL SEEMS REASONABLE WITH THE LATEST RUNS.
HAVE FOLLOWED THAT WHICH TRANSITIONS THE LINGERING PRECIPITATION
OVER THE EAST TO SNOW BY THROUGH 5-6AM. OVER THE WEST HALF...HAVE
SEEN A LITTLE BIT OF A LULL (LIGHT SNOW FARTHER TO THE SOUTHWEST IN
SOUTHWESTERN WISCONSIN TIED WITH BETTER MOISTURE AND TRAILING COLD
FRONT)...BUT WITH THE COLDER AIR MOVING INTO THE AREA...VISIBILITIES
STARTED TO FALL WITH SNOW AT KIWD/KCMX AROUND 1AM AND HAVE BEEN
BOUNCING THROUGH THE NIGHT (LIKELY MORE TIED WITH THE LIGHT SNOW
SHOWERS MOVING IN FROM WISCONSIN THAN PURE LAKE EFFECT AT THIS
POINT). 3AM TEMPERATURES ARE STILL HOLDING ON TO THE LOWER 30S OVER
THE EASTERN 2/3RDS OF THE U.P. AND IN THE UPPER 20S TO THE WEST OF
THAT.
WITH THE COLDER AIR SURGING IN TODAY...EXPECT A TRANSITION TO PURE
LES THROUGH THE MORNING FOR THE NORTHERLY WIND SNOWBELTS BEFORE
GRADUALLY TRANSITIONING TO THE NORTHWEST WIND AREAS THROUGH THE
AFTERNOON. INVERSION HEIGHTS ARE FORECASTED TO BE AROUND 5KFT WHICH
IS SOMEWHAT LIMITING...BUT THE CLOUD WILL MOVE ENTIRELY WITHIN THE
DGZ THIS AFTERNOON AND WITH WINDS GENERALLY IN THE 15-25KT RANGE
THERE WON/T BE TOO MUCH FRACTURING. THUS...HAVE TRENDED SNOW RATIOS
UP INTO THE UPPER 20S AND WOULDN/T BE SURPRISED IF SOME LOCATIONS
END UP IN THE 30S TO 1 RANGE BASED OFF PAST SITUATIONS HERE AT OUR
OFFICE THAT HAVE YIELDED SNOW RATIOS AT OR EVEN ABOVE THOSE VALUES.
THE LOWER INVERSION HEIGHTS WILL LIKELY LIMIT THE OVERALL STRENGTH
OF THE LAKE EFFECT...BUT WITH RATIOS THAT HIGH STILL EXPECT
OCCASIONAL MODERATE SNOWFALL. HAVE SNOWFALL AMOUNTS OF 1 TO 4 INCHES
TODAY OVER THE FAVORED AREAS OVER THE FAR WESTERN U.P....WITH THE
GREATEST AMOUNTS OVER THE HIGHER TERRAIN OF GOGEBIC/ONTONAGON
COUNTIES. ONE OTHER LIMITING FACTOR FOR TODAY IS THAT THERE WILL BE
ENOUGH BACKING OF THE WINDS FROM NORTH-NORTHWEST TO NORTHWEST TODAY
TO MOVE THE BANDS AROUND ENOUGH TO LIMIT THE RESIDENCE TIME OF THE
STRONGER BANDS IN ANY ONE LOCATION. FARTHER TO THE EAST...EXPECT
SOME LAKE ENHANCEMENT NEAR LAKE SUPERIOR THROUGH THE DAY WITH THE
NORTH AND EVENTUALLY NORTHWEST WINDS...BUT INVERSION STRUGGLE TO
RISE MUCH ABOVE 4KFT WITH LESS FAVORABLE MOISTURE. THUS...DON/T
EXPECT MUCH MORE THAN A LIGHT DUSTING TO AN INCH OF SNOW TODAY THERE
AND EXPECT SCATTERED SNOW SHOWERS AND MAYBE A DUSTING OF SNOW FOR
THE REST OF THE U.P. AS THE COLD FRONT MOVES THROUGH AND THE SNOW
SHOWERS IN WISCONSIN SLIDE EAST-NORTHEAST THROUGH THE AREA. FINALLY
FOR TEMPERATURES...EXPECT STEADILY FALLING TEMPERATURES THROUGH THE
DAY...WITH VALUES AROUND SUNSET RANGING FROM THE MID TEENS OVER THE
WEST AND UPPER 20S OVER THE EAST.
FOR TONIGHT...EXPECT THE LAKE EFFECT TO CONTINUE FOR AREAS NEAR LAKE
SUPERIOR AS THE WINDS VEER BACK TO A MORE NORTHERLY DIRECTION IN
RESPONSE TO A SURFACE RIDGE TRYING TO NOSE INTO THE AREA AND A
SURFACE LOW LIFTING NORTH INTO THE LOWER GREAT LAKES. 850MB TEMPS
CONTINUE TO FALL THROUGH THE NIGHT (DOWN TO -21C OVER THE
WEST)...PUSHING THE CLOUD LAYER OUT OF THE DGZ. THAT WILL TRANSITION
THE SNOW FLAKE SIZE AND RATIOS DOWN THROUGH THE NIGHT. INVERSION
HEIGHTS STILL STAY IN THE 5-6KFT RANGE...SO STILL EXPECT LIGHT TO
OCCASIONALLY MODERATE LAKE EFFECT TO OCCUR AND HAVE ANOTHER 1-4
INCHES OF SNOW FOR THE SAME AREAS OUT WEST. THE EAST WILL SEE A
COMBINATION OF TWO FEATURES FOR TONIGHT. FIRST...THE AREA WILL BE
BRUSHED BY SNOW ASSOCIATED WITH THE SURFACE LOW LIFTING NORTHEAST
THROUGH THE EASTERN GREAT LAKES. THE HEAVIEST SNOW WILL OCCUR JUST
TO THE SOUTHEAST OF THE AREA...BUT COULD SEE A LIGHT DUSTING OVER
SOUTHERN SCHOOLCRAFT AND SOUTHERN LUCE COUNTIES. THEN FOR THE LAKE
EFFECT AREAS CLOSER TO LAKE SUPERIOR...THINK THINGS WILL INTENSIFY
THROUGH THE NIGHT AS THE COLDER AIR FINALLY ARRIVES...RAISING
INVERSION HEIGHTS TO 5-6KFT AND PUTS THE CLOUD WITHIN THE DGZ.
EXPECT SNOWFALL AMOUNTS TO BE SIMILAR TO OUT WEST IN THE FAVORED
TIME COINCIDING WITH THE CLOUD IN THE DGZ WITH 1 TO 3 INCHES OF
SNOW. WHILE WINDS WILL BE PICKING UP OVER THE EAST...THINK THE AREA
WILL NEED SOME TIME TO ACCUMULATE SNOW (AFTER THE RAIN THIS EVENING)
BEFORE THE BLOWING SNOW WILL REALLY PICKUP.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 349 AM EST SAT JAN 9 2016
MEDIUM/EXTENDED RANGE GUIDANCE CONTINUES TO INDICATE A HI AMPLITUDE
WRN NAMERICA UPR RDG/ERN TROF WL DOMINATE THE COMING WEEK...
RESULTING IN BLO NORMAL TO WELL BLO NORMAL TEMPS FOR UPR MI MOST OF
THE TIME. LES WL BE COMMON DURING MUCH OF THIS TIME AS THE COLD
ARCTIC AIR FLOWS OVER THE RELATIVELY WARM WATERS OF LK SUP.
SUN...SINCE SHRTWV LIFTING NEWD FM THE LOWER MS RIVER VALLEY TOWARD
THE UPR OH RIVER VALLY AT 12Z SUN IS FCST TO REMAIN OUT OF PHASE
WITH ARCTIC BRANCH TROF SHIFTING INTO THE WRN GREAT LKS...ASSOCIATED
SFC LO AND BULK OF DYNAMIC SUPPORT ASSOCIATED WITH THE SHRTWV/
DEEPER MSTR/HEAVIER PCPN ARE FCST TO REMAIN MAINLY TO THE E OF THE
CWA. HOWEVER...AS CYC NNW SLOWLY BACK NW FLOW DRAWS H85 TEMPS IN THE
-20C TO -23C RANGE INTO THE UPR LKS...WL FCST CATEGORICAL POPS FOR
LES IN THE FAVORED SN BELTS NEAR LK SUP. BUT THE INTENSITY OF THIS
LES WL BE LIMITED BY RATHER LO INVRN BASE FCST NEAR H85 AND INCRSGLY
POOR SN GROWTH ASSOCIATED WITH THE ARRIVAL OF THE VERY COLD AIR THAT
WL PUSH THE DGZ TO NEAR THE SFC. DOWNSLOPE NATURE OF THE BACKING
LLVL NW FLOW WL BRING DRY WX TO THE SCENTRAL. WITH THE INFLUX OF THE
ARCTIC AIR...MAX TEMPS ON SUN WL HOLD IN THE SINGLE DIGITS ABOVE 0F
OVER MUCH OF THE W HALF.
SUN NGT/MON...NW LLVL WINDS AT 00Z MON ARE FCST TO BACK SLOWLY AS
THE DEEPENING SFC LO EXITS TO THE NE THRU QUEBEC AND COLD SFC HI
PRES IN THE PLAINS SHIFTS INTO THE LOWER MS RIVER VALLEY IN ADVANCE
OF ANOTHER SHRTWV WITHIN THE NW FLOW ALF DIGGING SEWD TOWARD THE UPR
MS RIVER VALLEY. H85 TEMPS ARE FCST TO MODERATE A FEW DEGREES TO
-18C TO -21C. ALTHOUGH THE INCRSG H85 TEMPS WL ALLOW FOR BETTER SN
GROWTH...THE SHIFTING WINDS SHOULD TEND TO LIMIT BAND RESIDENCE
TIME/PURE LES ACCUMS. HOWEVER...THERE MAY BE SOME MDT LES OVER NRN
ONTONAGON/CENTRAL HOUGHTON COUNTY WHERE MORE PERSISTENT LLVL CNVGC
WL BE ENHANCED ALONG A LK INDUCED TROF THAT IS FCST BY MANY OF THE
MODELS TO CROSS THE CENTRAL KEWEENAW PENINSULA AND PERHAPS OVER THE
FAR E FM GRAND MARAIS TO WHITEFISH PT. VERY COLD AIR TO THE S OF
THIS TROF...WITH MIN TEMPS -5F TO PERHAPS -10F...WL ALSO ACCENTUATE
LAND BREEZE CNVGC. TENDED TO BUMP UP QPF OVER CONSENSUS FCST IN THIS
AREA...WHERE AN LES HEADLINE WL LIKELY BE NECESSARY. RIGHT NOW...
LOOKS LIKE WIND CHILLS WL NOT FALL TO ADVY CRITERIA /-25F/ AS WINDS
WL BE LIGHTER OVER THE INTERIOR W WHERE MIN TEMPS WL BE LOWEST.
ALTHOUGH H85 TEMPS WL BE A FEW DEGREES HIER ON MON THAN ON SUN...A
MORE W WIND COMPONENT THAT LIMITS LK SUP MODERATION SUGGESTS MAX
TEMPS WL BE NO WARMER AND PERHAPS EVEN COLDER ON MON THAN SUN. THIS
MORE BACKED FLOW WL KEEP MUCH OF THE CWA DRY TO THE S OF THE MORE
DOMINANT LES BAND THAT MAY IMPACT NRN ONTONAGON/CENTRAL HOUGHTON
COUNTY AND PERHAPS THE FAR E NEAR LK SUP.
MON NGT/TUE...MEDIUM RANGE GUIDANCE IS COMING INTO BETTER AGREEMENT
ON TIMING/TRACK OF CLIPPER TYPE SHRTWV FCST TO DIG OVER NRN MN BY
00Z TUE...OVER THE LOWER GREAT LKS AT 12Z TUE AND THEN OVER SE
ONTARIO LATE ON TUE. ALTHOUGH THE ACCOMPANYING SFC LO IS PROGGED TO
PASS TO THE S THRU WI AND LOWER MI...MODELS SHOW LLVL W FLOW ON MON
EVNG BECOMING SHARPLY CYC AND VEERING TO THE NNW ON TUE...WHICH IS
PROGGED TO ADVECT H85 TEMPS AS LO AS -22C TO -24C BACK OVER UPR MI
BY LATER ON TUE. SINCE THE DEEP LYR QVECTOR CNVGC IS PROGGED TO
IMPACT UPR MI TO THE N OF THE SHRTWV TRACK...GFS FCST SDNGS SHOW
DEEP MOISTENING DESPITE LACK OF MSTR INFLOW INTO THE AREA AHEAD OF
THE SHRTWV THAT WL LIMIT QPF AWAY FM LK SUP MOISTENING. BUT LOOKS
LIKE A HEADLINE LK ENHANCED EVENT MAY BE IN THE WORKS FOR LATE MON
NIGHT THRU MUCH OF TUE FOR THE FAVORED AREAS IMPACTED BY THE LES OFF
LK SUP. GUSTY WINDS AND INCRSGLY SMALL SN FLAKES ASSOCIATED WITH
DESCENDING DGZ MAY ALSO RESULT IN SOME VERY LO VSBYS.
EXTENDED...ON WED...WINDS WL BACK AGAIN TO A MORE W DIRECTION AS HI
PRES TRAILING THE DEPARTING CLIPPER SHRTWV SHIFTS FM THE NRN PLAINS
INTO THE OH RIVER VALLEY. WITH THE BACKING FLOW...THE PURE LES WL
BECOME MORE RESTRICTED TO THE KEWEENAW AND AREAS NEAR LK SUP FM
GRAND MARAIS TO WHITEFISH PT. SOME OF THE LONGER RANGE GUIDANCE
HINTS ANOTHER SHRTWV/SFC LO WL APRCH LATER WED/THU...WITH WAA BAND
OF SN ARRIVING TO THE N OF ASSOCIATED WARM FNT...FOLLOWED BY SOME
LES ON FRI AS A MORE MODERATELY COLD AIRMASS RETURNS. BUT EXPLICIT
MODELS SHOW CONSIDERABLE VARIABILITY DURING THIS LATE WEEK PERIOD...
SO DID NOT STRAY FM CONSENSUS FCST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 644 AM EST SAT JAN 9 2016
COLD AIR MOVING INTO THE AREA TODAY WILL LEAD TO A PROLONGED PERIOD
OF LAKE EFFECT SNOW OVER UPPER MICHIGAN. THE LAKE EFFECT SNOW WILL
DEVELOP FROM WEST TO EAST THROUGH THE DAY...LEADING TO LOWERING
VISIBILITIES FROM MVFR TO IFR BY THIS AFTERNOON AND POSSIBLY
REACHING LIFR AT TIMES TONIGHT AT KCMX/KIWD. CEILINGS WILL REMAIN
FAIRLY STEADY IN THE BORDERLINE IFR/MVFR CATEGORY THIS MORNING
BEFORE SLOWLY RISING INTO THE MIDDLE OF THE MVFR RANGE TONIGHT.
MAY NEED TO ADD BLOWING SNOW FOR TONIGHT AS WINDS INCREASE...BUT
LATEST TRENDS IN THE MODELS HAVE WINDS LOWER THAN INITIALLY
EXPECTED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 AM EST SAT JAN 9 2016
A BROAD SURFACE LOW OVER NORTHERN LAKE MICHIGAN WILL CONTINUE
NORTHEAST AND SLOWLY DISSIPATE TODAY WHILE A SECONDARY LOW TAKES
SHAPE IN THE SOUTHERN PLAINS. WINDS HAVE ALREADY SHIFTED TO THE
NORTHWEST OVER THE WESTERN HALF OF THE LAKE AND EXPECT THAT WIND
SHIFT TO SLIDE EAST ACROSS THE REST OF THE LAKE THROUGH THE MORNING
HOURS. AT THIS POINT...ONLY EXPECT WINDS UP TO 30KTS THROUGH THIS
EVENING...BUT AS THE SECONDARY LOW LIFTS NORTHEAST THROUGH THE
SOUTHEASTERN GREAT LAKES LATE TONIGHT AND SUNDAY MORNING...THE
GRADIENT BETWEEN THE LOW AND THE HIGH IN THE CENTRAL/NORTHERN
PLAINS WILL PRODUCE OCCASIONAL NORTHERLY GALES TO 35KTS OVER THE
EASTERN HALF OF LAKE SUPERIOR. WITH ONLY MARGINAL GALES
EXPECTED...WILL KEEP THE GALE WATCH IN PLACE AND ALLOW THE DAY
SHIFT ONE FINAL LOOK TO SEE IF THE MODELS CONTINUE TO TREND WINDS
DOWN. ALSO EXPECT A PERIOD OF FREEZING SPRAY AND MAY NEED A HEAVY
FREEZING SPRAY WARNING IF THE WINDS/WAVES STAY AT THE CURRENTLY
FORECASTED LEVELS. THE WINDS WILL QUICKLY DIMINISH SUNDAY NIGHT AS
THE LOW DEPARTS...BUT ANOTHER LOW WILL QUICKLY DROP SOUTHEAST ACROSS
THE UPPER GREAT LAKES MONDAY NIGHT AND BRING ANOTHER POTENTIAL FOR
NORTHERLY GALES TUESDAY INTO TUESDAY EVENING. BEHIND THE LOW...A
HIGH PRESSURE RIDGE WILL MOVE INTO THE AREA FOR WEDNESDAY AND
DIMINISH WINDS BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT FOR
LSZ249>251-266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
951 AM EST SAT JAN 9 2016
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA LATE IN THE DAY INTO
THIS EVENING. A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA
EARLY SUNDAY MORNING. SHOWERS AND SOME THUNDERSTORMS WILL REMAIN
IN THE FORECAST UNTIL THE FRONT SWEEPS TO OUR EAST. A SECONDARY
COLD FRONT WILL MOVE ACROSS THE AREA TUESDAY NIGHT. TEMPERATURES
WILL BE BELOW NORMAL FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...THIS IS A VERY COMPLEX FORECAST TODAY AND
TONIGHT WITH PLENTY OF OPPORTUNITY FOR ERROR. A WARM FRONT/COASTAL
TROUGH NEAR THE WESTERN EDGE OF THE GULF STREAM WILL WALK WESTWARD
TOWARD THE COAST...MOVING ONSHORE SOMETIME EARLY THIS EVENING. THE
PRECISE TIMING OF THE FRONTAL PASSAGE WILL HAVE ENORMOUS IMPACTS
ON TEMPERATURES TODAY.
WEST OF THE FRONT THERE IS A THIN BUT EXPANSIVE DECK OF LOW
STRATUS WITH PATCHIER CIRRUS ALOFT. VISIBLE SATELLITE, WEBCAMS,
AND A LOOK OUT THE WINDOW REVEALS THERE ARE SOME THIN SPOTS IN
THIS LOW STRATUS CURRENTLY. WITH VAD WIND PROFILES INDICATING EAST
AND SOUTHEAST WINDS DOWN AS LOW AS 1000 FEET AGL...IT WON`T TAKE
MUCH TO ERODE THE THIN LAYER OF NE WINDS AND "JUMP" THE FRONT
ONSHORE. FORECAST HIGHS RANGE FROM THE MID 60S IN THE WILMINGTON
AREA WITH LOWER 60S ALONG THE COAST WEST OF CAPE FEAR. HIGHS
SHOULD REACH THE UPPER 50S TO AROUND 60 INLAND. ALL OF THESE
TEMPERATURES WILL BE ACHIEVED VERY LATE IN THE DAY AS WARM
ADVECTION MAY BE MORE IMPORTANT THAN INSOLATION.
AS IS TYPICAL, MODELS PAINT A VARIETY OF FORECAST POSITIONS FOR
THE FRONT. THE 06Z NAM WAS THE FASTEST TO BRING THE FRONT IN,
WHILE THE 00Z ARW-NMM WAS THE SLOWEST. AN MEDIAN TIME WAS JUST
AFTER SUNSET ALONG THE EAST-FACING BEACHES OF CAPE FEAR, WITH
WINDS TURNING SOUTHERLY THROUGHOUT THE AREA INCLUDING FAR INLAND
DURING THE EVENING HOURS AS THE COLD FRONT OFF THE WEST BECOMES
THE PRIMARY FEATURE AFFECTING THE PRESSURE GRADIENT AND LOW-LEVEL
WINDS.
RADAR/SATELLITE IMAGES SHOWS WAVES OF SHOWERS DEVELOPING OVER THE
GULF STREAM MOVING NORTHWESTWARD. THE HRRR AND HRRRX MODELS BOTH
SHOW THESE IMPACTING THE COAST THIS AFTERNOON BEGINNING BETWEEN
2-4 PM. POPS HAVE BEEN INCREASED TO 50-80 PERCENT DURING THE
AFTERNOON HOURS. PRECIP CHANCES INLAND ARE LESS CERTAIN GIVEN MUCH
LESS ATLANTIC TRANSPORT OF MOISTURE THAT FAR WEST PLUS OVERALL
WEAK FORCING. MEASURABLE RAIN OVER THE INLAND PEE DEE REGION WILL
PROBABLY FOCUS MORE ON ANY PRECIP AHEAD OF THE COLD FRONT LATE
TONIGHT.
SEVERE WEATHER POTENTIAL APPEARS QUITE LIMITED GIVEN SURFACE-BASED
INSTABILITY REMAINING NEAR ZERO TODAY AND TONIGHT. ALTHOUGH
ELEVATED INSTABILITY MAY GROW TO 400-600 J/KG...FAIRLY WEAK UPPER
LEVEL SUPPORT AND THE PRESENCE OF A LARGE DRY SLOT ALOFT THIS
EVENING WILL TEND TO REMOVE CONVECTION DURING THE TIME WHEN THE
BEST WIND SHEAR WILL BE PRESENT. WHILE I CANNOT RULE OUT SEVERE
WEATHER COMPLETELY, THIS DOES NOT APPEAR TO BE A VERY CONCERNING
SETUP AT THIS TIME.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...STRONG COLD FRONT COMES THROUGH TO START
THE PERIOD AND FOR A FEW DAYS NOW GETTING SUNDAY`S HIGH
TEMPERATURE SEEMS AWFULLY TRICKY AS IT WILL LIKELY BE IN THE
MORNING IF NOT PREDAWN. LINGERING COASTAL SHOWERS TO START THE
PERIOD, IF ANY, WILL QUICKLY SCOOT OFFSHORE IN THE STRONG COLD AND
DRY ADVECTION REGIME. 850 TEMPS PLUNGE TO ABOUT -2C SUNDAY NIGHT
BRINGING SOME SEASONABLE MID 30S AREA-WIDE. WITH NO REAL RECOVERY
IN LOW LEVEL THERMAL FIELDS ON MONDAY AFTERNOON HIGHS A SOLID
CATEGORY BELOW NORMAL WITH HIGHS IN THE MID TO UPPER 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE ON TUESDAY IS SUPPRESSED TO
OUR SOUTH AND WEST ON TUESDAY WITH THE APPROACH OF A STRONG UPPER
TROUGH AND MOISTURE-DEPRIVED COLD FRONT SLATED FOR A TUESDAY NIGHT
PASSAGE AFTER A SEASONABLE TO SLIGHTLY COOL TUESDAY TEMPERATURES
WILL TAKE A TURN DOWNWARD POSSIBLY FOR THE REMAINDER OF THE PERIOD
THOUGH MOST OF THE TIME CLOUD COVER WILL BE LOW END PARTLY CLOUDY
IF NOT LESS. THIS WILL CHANGE ON THURSDAY AS SOME MOISTURE STREAMS
IN ALOFT AHEAD OF A SOUTHERN BRANCH DISTURBANCE. THIS FEATURE MAY
BRING RAIN CHANCES ON FRIDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...IFR OR LOWER CONDITIONS ONGOING AND ENVIRONMENT
REMAINS CONDUCIVE FOR THESE CONDITIONS TO PERSIST THROUGH
18Z.
HIGH CONFIDENCE WE WILL SEE PREDOMINATELY IFR CONDITIONS
THROUGH A GOOD CHUNK OF THE FORECAST PERIOD. CIGS MAY IMPROVE
TO MVFR AFT 18Z BUT IFR CONDITIONS COULD RETURN AFTER SUNSET.
A WARM FRONT MOVING THROUGH THE AREA OVERNIGHT SHOULD BRING AN
END TO THE IFR CONDITIONS IN THE 04Z TO 08Z WINDOW BUT SHOWERS
COULD RESULT IN MVFR CONDITIONS AFTER PREDOMINANT IFR LIFTS.
EXTENDED OUTLOOK...POTENTIAL FOR ADDITIONAL IFR-MVFR EARLY SUNDAY.
OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...A WARM FRONT/COASTAL TROUGH NEAR THE
WESTERN EDGE OF THE GULF STREAM WILL MOVE WESTWARD TODAY,
REACHING THE COAST OF CAPE FEAR EARLY THIS EVENING. THE FRONT
SHOULD THEN JUMP INLAND ALLOWING WINDS TO BECOME SOUTHERLY ALONG
THE SOUTH CAROLINA COAST TOO. UNTIL THEN, NORTHERLY WINDS WILL
CONTINUE ALONG THE COAST WITH WIND SPEEDS UP TO 20 KNOTS AT TIMES
IN A FAIRLY TIGHT PRESSURE GRADIENT. THIS HAS BUILT SEAS UP TO 5
FEET NEAR AND NORTH OF CAPE FEAR...AND AN EXERCISE CAUTION
HEADLINE WILL REMAIN POSTED THERE UNTIL 11 AM.
SHOWERS DEVELOPING OVER THE GULF STREAM ARE MOVING NORTHWESTWARD
AND SHOULD OVERSPREAD THE CAPE FEAR AREA AND MYRTLE BEACH WATERS
THIS AFTERNOON. ISOLATED THUNDERSTORMS ARE POSSIBLE TOO. AFTER A
LULL DURING THE EVENING HOURS, ANOTHER WAVE OF SHOWERS AND STORMS MAY
PUSH ACROSS THE AREA AHEAD OF THE COLD FRONT LATE TONIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...A HEALTHY COLD FRONT WITH APPRECIABLE
DYNAMICS ALOFT CROSSES EARLY SUNDAY. WIND AND SEAS SHOULD READILY
RAMP UP TO ADVISORY LEVELS WHERE THEY WILL REMAIN MUCH OF SUNDAY
NIGHT AS WINDS VEER TO W AND THEN NW. LATER SUNDAY NIGHT INTO
MONDAY WILL FEATURE A CONSIDERABLE DECREASE IN BOTH WIND AND SEAS
AS HIGH PRESSURE BUILDS INTO THE GULF STATES AND A RIDGE AXIS
POKES INTO THE CAROLINAS AND MID ATLANTIC REGION EASING THE
GRADIENT ALONG MOST OF THE EAST COAST.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...A VERY LIGHT GRADIENT IN PLACE ON TUESDAY
AS THE POST-FRONTAL HIGH SINKS INTO THE GULF STATES AND WEAKENS
CONSIDERABLY. A MODERATELY STRONG COLD FRONT COMES THROUGH TUESDAY
NIGHT WITH GOOD DYNAMICS IN THE LOW TO MID LEVELS FOR SOME FAIRLY
STRONG WINDS THAT COULD YIELD SCEC FOR EITHER WIND OR SEAS. THIS
POST-FRONTAL HIGH WILL NOT BE SO QUICK TO WEAKEN NOR ENTER THE
AREA ON WEDNESDAY KEEPING THE GRADIENT A BIT TIGHTER BUT PROBABLY
NOT TO WHERE HEADLINES WILL BE NEEDED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...RAN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
610 AM EST SAT JAN 09 2016
.SYNOPSIS...A RIDGE OF COOL HIGH PRESSURE AT THE SURFACE WITH
PLENTIFUL MOISTURE ALOFT WILL KEEP UNSETTLED WEATHER THROUGH
TONIGHT... AS A STRONG STORM SYSTEM APPROACHES FROM THE WEST AND
MOVES THROUGH THE REGION. THIS SYSTEM WILL EXIT ON SUNDAY... WITH
CLEARING SKIES AND DRIER WEATHER THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 240 AM SATURDAY...
THROUGH THIS MORNING... WIDESPREAD FOG AND THICK STRATUS ARE LIKELY
TO PERSIST WITHIN THE WEDGE REGIME... FEATURING A DAMMING SURFACE
HIGH CENTERED OFF THE CANADIAN MARITIMES NOSING SW INTO NC... CAPPED
BY WEAK BUT STEADY MOIST UPGLIDE. BLOCKED BY THE MOUNTAINS TO THE
WEST AND A FRONTAL ZONE WELL TO OUR SOUTH AND SE... THE WEDGE SHOULD
STAY LOCKED IN WELL INTO THE MORNING GIVEN THE STAGNANT SURFACE
AIR... PROFOUND CLOUD DEPTH... AND LACK OF ANY MECHANISM TO DISPERSE
IT IN THE VERTICAL. THE HRRR AND HRRR-X ARE STILL SHOWING INCREASING
FOG DENSITY THROUGH DAYBREAK... AND WHILE THIS IS FAR FROM CERTAIN
GIVEN THE EXTENT OF STRATUS... WILL KEEP A CLOSE EYE ON FOG
TRENDS... AND DENSE FOG ADVISORY MAY BE NEEDED THIS MORNING. THE
MOIST UPGLIDE DOESN`T APPEAR TO BE STRONG OR DEEP ENOUGH FOR
ANYTHING MORE THAN PATCHY DRIZZLE OVER THE NEXT SEVERAL HOURS... AND
OTHER FORCING MECHANISMS ARE LACKING AS WELL GIVEN THE DEPARTURE TO
OUR NE OF A BATCH OF MID LEVEL VORTICITY... SO POPS THROUGH THIS
MORNING WILL BE LOW. TEMPS WILL BE SLOW TO RISE THROUGH THE UPPER
40S AND LOW-MID 50S THIS MORNING.
MIDDAY TODAY THROUGH TONIGHT: THE ACTIVE SOUTHERN STREAM REACHES ITS
PEAK IMPACT ON THE SOUTHEAST STATES LATE THIS AFTERNOON AND TONIGHT
WITH PASSAGE OF A POTENT MID LEVEL SHORTWAVE TROUGH AND SURFACE LOW
TO OUR WEST AND NW... MOVING FROM THE LOWER MISS VALLEY NEAR MIDDAY
THROUGH THE TN AND ERN OH VALLEY THROUGH TONIGHT. WHILE THE CHANCE
OF EVERYONE SEEING AT LEAST SOME SHOWERS (AND PERHAPS A STORM OR
TWO... MORE ON THAT LATER) IS HIGH CONSIDERING THE PROJECTIONS OF
MUCH ABOVE NORMAL PW (0.90-1.20")... IT APPEARS THAT THE BULK OF THE
DYNAMIC FORCING FOR ASCENT WILL HOLD TO OUR WEST AND NORTH. THESE
MECHANISMS INCLUDES THE MID LEVEL DPVA WITH THE SHORTWAVE TROUGH AS
WELL AS THE STRONGEST UPPER DIVERGENCE WITH THE LEFT EXIT REGION OF
THE SUBTROPICAL JET... BOTH OF WHICH TAKE A PATH NW OF CENTRAL NC.
BUT THERE SHOULD STILL BE A STRONG INFLUX OF LOWER LEVEL MOISTURE...
FOCUSED INTO CENTRAL AND ERN NC OUT AHEAD OF A WEAK SURFACE LOW NOW
OVER SOUTH FLA AND EXPECTED TO TRACK NORTHWARD TODAY AND THROUGH
CENTRAL NC TONIGHT... DRAWING ENOUGH ATLANTIC MOISTURE INTO THE AREA
FOR A PERIOD OF CATEGORICAL POPS... FOCUSING LATE AFTERNOON THROUGH
TONIGHT... WITH GREATEST COVERAGE AND DURATION OCCURRING ACROSS THE
NRN AND ERN FORECAST AREA. AS THIS SURFACE LOW APPROACHES AND DRAWS
THE COASTAL WEDGE FRONT WESTWARD INTO THE NC COASTAL PLAIN THIS
EVENING/TONIGHT... WEAK INSTABILITY (PEAKING AT A MUCAPE OF ABOUT
500-1000 J/KG TONIGHT) ALONG WITH IMPRESSIVE DEEP LAYER SHEAR AOA 50
KTS COULD SUPPORT A FEW POCKETS OF STRONGER CONVECTION... MOST
LIKELY (ACCORDING TO THE LATEST MODEL RUNS) DURING THE EARLY TO MID
EVENING HOURS. IT`S UNCLEAR WHETHER OR NOT ANY WEAK INSTABILITY WILL
BE ACHIEVED DURING THE TIME OF GREATEST LOW LEVEL SHEAR (0-3 KM SRH
PREDICTED TO REACH 300-400 M2/S2 ON THE NAM AND ABOUT HALF THAT ON
THE GFS)... WHICH WOULD INFLUENCE THE THREAT OF SUPERCELLS. SUCH A
SCENARIO SEEMS UNLIKELY BUT THE POTENTIAL WILL BE MONITORED. IF
SURFACE DEWPOINTS OVER OUR EAST CLIMB INTO THE UPPER 50S TO AROUND
60 AS EXPECTED HOWEVER... WITH WINDS BECOMING MORE UNIDIRECTIONAL (A
STRAIGHTENING HODOGRAPH)... THERE COULD BE A RISK OF BOWING SEGMENTS
AND STRONG STRAIGHT LINE WINDS TONIGHT. WILL RESTRICT AN ISOLATED
MENTION OF THUNDER TONIGHT FROM RALEIGH EAST AND SOUTH... ALONG AND
EAST OF THE ANTICIPATED TRACK OF THE WEAK SURFACE LOW. THE
WARM/WEDGE FRONT WILL SHIFT BACK EAST OVER THE COASTAL PLAIN LATE
TONIGHT AS THE OCCLUDED FRONT APPROACHES. EXPECT HIGHS FROM THE
UPPER 40S TO NEAR 50 IN THE TRIAD TO NEAR 60 IN OUR FAR SE (CLINTON
TO GOLDSBORO). TEMPS SHOULD SLIP JUST A FEW DEGREES EARLY TONIGHT...
TO THE MID 40S NW TO MID-UPPER 50S SE... WITH STEADY TEMPS OR A
SLIGHT RISE OVERNIGHT. -GIH
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 245 AM SATURDAY...
CONSENSUS OF THE LATEST MODELS IS TO SHIFT THE FRONTAL ZONE AND
ATTENDANT PRECIP EAST OUT OF THE COASTAL PLAIN SUN MORNING... WITH
THE ONSET OF BRISK AND GUSTY SW WINDS... SHIFTING TO WESTERLY LATE
IN THE DAY... AS THE SECONDARY COLD FRONT (TRAILING THE POTENT
SURFACE LOW THAT WILL ACCOMPANY THE VORTICITY/UPPER DIVERGENCE MAX
UP THROUGH LAKE ERIE/LAKE ONTARIO) PUSHES EAST INTO THE AREA LATE.
LOW LEVEL THICKNESSES START TO DROP SUNDAY MORNING BUT WILL
INITIALLY BE OFFSET BY INCREASING SUNSHINE AND THE DELAY IN COLD AIR
ADVECTION. HIGHS SHOULD BE IN THE MID 50S TO LOWER 60S EARLY IN THE
DAY... WITH READINGS SLIPPING LATER IN THE DAY. WITH THE TIGHT MSLP
GRADIENT IN THE WAKE OF THE LAKE ERIE LOW... SUSTAINED WINDS OF 15-
20 KTS APPEAR LIKELY... WITH FREQUENT GUSTS TO AROUND 30 MPH... BOTH
LIGHTENING UP LATE IN THE DAY. MOSTLY CLEAR SUN NIGHT WITH
DIMINISHING WINDS AND WINDS BECOMING WNW AS COLDER AIR RUSHES IN.
LOWS 25-33. -GIH
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 230 AM SATURDAY...
THE WORK WEEK BEGINS WITH HIGH PRESSURE IN PLACE OVER THE DEEP SOUTH
AND SOUTHWESTERLY FLOW ALOFT WHICH WILL KEEP CENTRAL NC DRY WITH
SLIGHTLY BELOW NORMAL TEMPERATURES IN PLACE AS HIGHS WILL CLIMB INTO
THE LOW TO MID 40S MONDAY WITH LOWS IN THE MID TO UPPER 20S.
MODERATION OF THE TEMPERATURES WILL INCREASE ON TUESDAY AS THICKNESS
VALUES RISE ABOUT 15 METERS...THUS CORRESPONDING TO ABOUT A 5 DEGREE
TEMPERATURE INCREASE FOR HIGHS ON TUESDAY. EXPECT MID 40S IN THE NW
PIEDMONT TO NEAR 50 DEGREES IN THE SOUTHEAST.
THAT IS WHERE THE MODERATION ENDS HOWEVER AS A COLD FRONT COMES
RUSHING INTO THE AREA TUESDAY NIGHT AND EARLY WEDNESDAY MORNING.
THIS WILL KEEP LOWS BELOW FREEZING WEDNESDAY MORNING...MID 20S TO
NEAR 30 DEGREES. A VERY STRONG PRESSURE GRADIENT WILL ACCOMPANY THE
FRONTAL PASSAGE AND GUSTY WINDS CAN BE EXPECTED. ACCORDING TO GFS
BUFFER SOUNDINGS...GUSTS COULD BE AS HIGH AS 25 KTS BASED ON
MOMENTUM TRANSFER TO THE SURFACE. RIGHT NOW MODELS REMAIN DRY...BUT
A BRIEF FLURRY OR TWO CANT BE RULED OUT AS THE UPPER TROUGH MOVES
THROUGH EARLY WEDNESDAY MORNING. NO IMPACTS ARE EXPECTED ASIDE FROM
VERY STRONG COLD AIR ADVECTION. THIS WILL KEEP MAX TEMPERATURES DOWN
IN THE UPPER 30S ACROSS THE NORTH TO LOW 40S IN THE SOUTHERN TIER.
LOWS IN THE MIDDLE 20S.
AFTER THE UPPER TROUGH CROSSES THE AREA WEDNESDAY MORNING...SURFACE
HIGH PRESSURE OVER THE SOUTH WILL BEGIN TO MIGRATE NORTHEASTWARD OVER
THE CAROLINAS...RELAXING THE PRESSURE GRADIENT. SOUTHWESTERLY FLOW
ALOFT WILL ONCE AGAIN MODERATE TEMPERATURES BACK INTO THE MID TO
UPPER 40S ON THURSDAY AFTERNOON WITH UPPER 20S TO LOWER 30S THURSDAY
NIGHT.
MODELS DIFFER IN THE APPROACH OF A LOW PRESSURE SYSTEM THAT FORMS
OVER THE WESTERN GULF OF MEXICO WEDNESDAY NIGHT AND ENDS UP
SOMEWHERE OFF OF THE EAST COAST ON FRIDAY MORNING. THE GFS SOLUTION
KEEPS THE LOW OFF OF THE COAST ON FRIDAY BUT THE ECMWF DOUSES
CENTRAL NC WITH PRECIPITATION FRIDAY MORNING. AT THIS TIME...IT
APPEARS MOST OF THE PRECIPITATION WOULD BE LIQUID AS TEMPERATURES
MODERATE INTO THE UPPER 40S TO LOWER 50S. AGAIN A FLURRY CANT BE
RULED OUT AT THE ONSET OF PRECIPITATION IN THE NORTHWEST PIEDMONT
BUT AS OF NOW THIS WOULD BE A RAIN EVENT. PLENTY OF TIME FOR THINGS
TO CHANGE AS THE PARENT LOW HASN`T BEGUN TO FORM YET.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 610 AM SATURDAY...
HIGH CONFIDENCE IN ADVERSE AVIATION CONDITIONS TONIGHT THROUGH MUCH
OF THIS MORNING... WITH ONLY SLOW IMPROVEMENT THEREAFTER. A WEDGE OF
COOL HIGH PRESSURE WILL CONTINUE TO NOSE IN FROM THE NE AT THE
SURFACE... WHILE DEEP MOISTURE STREAMS INTO THE AREA JUST OFF THE
SURFACE. THIS WILL KEEP DEEP LOW IFR/LIFR CLOUDS OVER THE REGION
WITH WIDESPREAD IFR/LIFR FOG. THE STAGNANT AIR MASS AND CLOUD DEPTH
WILL KEEP THESE ADVERSE CONDITIONS LOCKED IN LONGER THAN USUAL THIS
MORNING... AS IT MAY BE THE NOON HOUR OR EARLY AFTERNOON BEFORE WE
ACHIEVE MVFR CONDITIONS AT CENTRAL NC AIRFIELDS. AN APPROACHING
STORM SYSTEM FROM THE SOUTH AND SW WILL THEN BRING INCREASING CHANCE
FOR SHOWERS AND ISOLATED STORMS STARTING MID-LATE THIS AFTERNOON AND
LASTING THROUGH TONIGHT... WITH CONDITIONS AGAIN DETERIORATING TO
IFR BY THIS EVENING. AVIATION INTERESTS SHOULD BE ALERT FOR STRONG
WINDS FROM THE SE AT 1500-3000 FT AGL PRECEDING THE FRONT TONIGHT.
THESE STRONG WINDS FROM THE SE JUST OFF THE GROUND WILL CONTINUE TO
INCREASE AND VEER TO SOUTHWESTERLY LATE TONIGHT INTO SUN MORNING.
LOOKING BEYOND 12Z SUN MORNING... POOR AVIATION CONDITIONS WILL
PERSIST UNTIL PASSAGE OF A COLD FRONT FROM WEST TO EAST EARLY SUN
MORNING. CLEARING SKIES AND A TREND TO VFR ARE EXPECTED SUNDAY...
ALTHOUGH STRONG GUSTY WINDS FROM THE WEST ARE LIKELY POST-FRONT. VFR
CONDITIONS ARE EXPECTED TO DOMINATE THROUGH WED... ALTHOUGH GUSTY
WINDS MAY RETURN WITH A DRY COLD FRONT PASSAGE TUE NIGHT/WED. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1038 AM EST SAT JAN 9 2016
.DISCUSSION...
LATEST HRRR AND RAP REFLECTIVITY SIMIULATIONS SHOW A LATER ARRIVAL
OF RAIN INTO THE AREA THAN PREVIOUS RUNS...AND THIS LINES UP WELL
WITH CURRENT RADAR TRENDS. PRECIP NEAR THE MS/AL STATE LINE WILL
NOT ARRIVE UNTIL AFTER 18Z...SO WILL ADJUST POPS TO DELAY ANY
PRECIP CHANCES UNTIL AFTER THIS TIME...AND LOWER POPS TODAY DOWN
INTO THE LIKELY RANGE. A SLIGHT DOWNWARD ADJUSTMENT OF TEMPERATURES
WILL BE MADE AS WELL. WITH CLOUDS SPREADING FROM SOUTH TO
NORTH...THE WARMEST TEMPS TODAY WILL BE IN NORTHERN AREAS.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
503 AM MST SAT JAN 9 2016
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 300 AM MST SAT JAN 9 2016
STILL GETTING VERY LIGHT SNOW OR FLURRIES IN AREAS ALONG
INTERSTATE 80...HOWEVER VISIBILITY IS MOSTLY ABOVE 3SM AND
ACCUMULATIONS ARE MINIMAL. THESE SNOW SHOWERS SHOULD GRADUALLY
DIMINISH THROUGH THE MORNING AS THE WEAK LIFT/SATURATION IN THE
700-500MB LAYER DEPARTS THE AREA. TEMPS WILL BE COLD TODAY WITH
MOST LOCATIONS STRUGGLING TO GET OUT OF THE LOW 20S (AROUND 15
DEGREES BELOW NORMAL). KEPT CHANCE POPS GOING FOR THE SIERRA
MADRE/SNOWY RANGES THROUGH THE EARLY EVENING HOWEVER ACCUMULATIONS
WILL BE LIGHT. NORTHWESTERLY FLOW ALOFT WILL REMAIN IN PLACE
THROUGH MONDAY WITH A CONTINUATION OF THE BELOW NORMAL
TEMPS...ALTHOUGH SOME PLACES WILL WARM TO AROUND FREEZING BY
MONDAY.
WILL SEE BREEZY-TO-WINDY CONDITIONS DEVELOP ACROSS SOUTHEAST WY
BY SUNDAY NIGHT INTO MONDAY AS PRESSURE FALLS OCCUR OVER
NEBRASKA/SOUTH DAKOTA AHEAD OF A SOUTHWARD-MOVING SHORTWAVE. THE
850MB CAG-CPR GRADIENT WILL INCREASE TO 45-50 METERS BY LATE
SUNDAY NIGHT SO WILL DEFINITELY SEE AN INCREASE IN WEST WINDS
ESPECIALLY IN THE WIND PRONE AREAS. WITH THE RECENT
SNOWFALL...COULD SEE SOME PATCHY BLOWING SNOW IN ARLINGTON AND
THE SOUTHERN LARAMIE RANGE. HOWEVER...NOT EXPECTING A WIDESPREAD
BLOWING SNOW EVENT AS THE OFFICE BLOWING SNOW MODEL IS GIVING LOW
PROBABILITIES. THE STRONG SHORTWAVE DIVES INTO THE NORTHERN PLAINS
BY MONDAY. THE COLDEST AIR AND BEST FORCING FOR PRECIP WILL
REMAIN ACROSS THE DAKOTAS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM MST SAT JAN 9 2016
GOING TO STAY COLD IN THE LONG TERM AS UPPER RIDGE STAYS WEST OF
THE CWA AND WE STAY IN NORTHWEST FLOW. 700MB TEMPERATURES OF -8 TO
-10C OVER SOUTHEAST WYOMING SHOULD YIELD HIGHS IN THE 20S TO
POSSIBLY LOW 30S WITH LOWS IN THE SINGLE DIGITS AND LOW TEENS.
GFS HINTING AT INCREASING WINDS THAT COULD CHANGE TEMPERATURE
FORECAST. BY TUESDAY...700MB WINDS ON THE GFS INCREASE TO 40KTS
ACROSS SOUTHEAST WYOMING. 850MB WINDS OF 30 TO 35KTS OVER THE
PANHANDLE. WILL WAIT FOR ANOTHER RUN OR TWO BEFORE INCREASING
TEMPERATURES AND WINDS.
GUIDANCE DIFFERS ON SYSTEM FOR THE END OF THE WEEK. GFS MUCH
FASTER ON BRINGING IN THE NEXT PACIFIC SHORTWAVE THURSDAY WHILE
ECMWF SLOWER AND FURTHER NORTH WITH THE SYSTEM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 501 AM MST SAT JAN 9 2016
LATEST HRRR GUIDANCE SHOWING IFR STRATUS MOVING INTO THE PANHANDLE
FROM THE NORTHEAST DURING THE MORNING HOURS. 11-3.9U SATELLITE
IMAGERY DOES SHOW A DECK MOVING SOUTHWEST...SO DO BELIEVE THIS
WILL HAPPEN. COULD PERSIST THROUGH THE AFTERNOON AS SUGGESTED BY
HRRR. DO THINK THOUGH THAT BY 18Z...CONDITIONS SHOULD IMPROVE.
WILL CONTINUE TO MONITOR.
&&
.FIRE WEATHER...
ISSUED AT 103 AM MST SAT JAN 9 2016
NO FIRE WEATHER CONCERNS. MINIMUM AFTERNOON HUMIDITY VALUES WILL
BE ABOVE 40 PERCENT. WIDESPREAD SNOW COVER WILL EXIST WITH THE
COLD TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
341 AM MST SAT JAN 9 2016
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 300 AM MST SAT JAN 9 2016
STILL GETTING VERY LIGHT SNOW OR FLURRIES IN AREAS ALONG
INTERSTATE 80...HOWEVER VISIBILITY IS MOSTLY ABOVE 3SM AND
ACCUMULATIONS ARE MINIMAL. THESE SNOW SHOWERS SHOULD GRADUALLY
DIMINISH THROUGH THE MORNING AS THE WEAK LIFT/SATURATION IN THE
700-500MB LAYER DEPARTS THE AREA. TEMPS WILL BE COLD TODAY WITH
MOST LOCATIONS STRUGGLING TO GET OUT OF THE LOW 20S (AROUND 15
DEGREES BELOW NORMAL). KEPT CHANCE POPS GOING FOR THE SIERRA
MADRE/SNOWY RANGES THROUGH THE EARLY EVENING HOWEVER ACCUMULATIONS
WILL BE LIGHT. NORTHWESTERLY FLOW ALOFT WILL REMAIN IN PLACE
THROUGH MONDAY WITH A CONTINUATION OF THE BELOW NORMAL
TEMPS...ALTHOUGH SOME PLACES WILL WARM TO AROUND FREEZING BY
MONDAY.
WILL SEE BREEZY-TO-WINDY CONDITIONS DEVELOP ACROSS SOUTHEAST WY
BY SUNDAY NIGHT INTO MONDAY AS PRESSURE FALLS OCCUR OVER
NEBRASKA/SOUTH DAKOTA AHEAD OF A SOUTHWARD-MOVING SHORTWAVE. THE
850MB CAG-CPR GRADIENT WILL INCREASE TO 45-50 METERS BY LATE
SUNDAY NIGHT SO WILL DEFINITELY SEE AN INCREASE IN WEST WINDS
ESPECIALLY IN THE WIND PRONE AREAS. WITH THE RECENT
SNOWFALL...COULD SEE SOME PATCHY BLOWING SNOW IN ARLINGTON AND
THE SOUTHERN LARAMIE RANGE. HOWEVER...NOT EXPECTING A WIDESPREAD
BLOWING SNOW EVENT AS THE OFFICE BLOWING SNOW MODEL IS GIVING LOW
PROBABILITIES. THE STRONG SHORTWAVE DIVES INTO THE NORTHERN PLAINS
BY MONDAY. THE COLDEST AIR AND BEST FORCING FOR PRECIP WILL
REMAIN ACROSS THE DAKOTAS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM MST SAT JAN 9 2016
GOING TO STAY COLD IN THE LONG TERM AS UPPER RIDGE STAYS WEST OF
THE CWA AND WE STAY IN NORTHWEST FLOW. 700MB TEMPERATURES OF -8 TO
-10C OVER SOUTHEAST WYOMING SHOULD YIELD HIGHS IN THE 20S TO
POSSIBLY LOW 30S WITH LOWS IN THE SINGLE DIGITS AND LOW TEENS.
GFS HINTING AT INCREASING WINDS THAT COULD CHANGE TEMPERATURE
FORECAST. BY TUESDAY...700MB WINDS ON THE GFS INCREASE TO 40KTS
ACROSS SOUTHEAST WYOMING. 850MB WINDS OF 30 TO 35KTS OVER THE
PANHANDLE. WILL WAIT FOR ANOTHER RUN OR TWO BEFORE INCREASING
TEMPERATURES AND WINDS.
GUIDANCE DIFFERS ON SYSTEM FOR THE END OF THE WEEK. GFS MUCH
FASTER ON BRINGING IN THE NEXT PACIFIC SHORTWAVE THURSDAY WHILE
ECMWF SLOWER AND FURTHER NORTH WITH THE SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 103 AM MST SAT JAN 9 2016
MAINLY MVFR CONDITIONS ACROSS THE NEBRASKA PANHANDLE AND SOUTHEAST
WYOMING WITH LIGHT SNOW. LATEST HRRR SHOWING SOME SIGNS OF
IFR/LIFR CONDITIONS IN THE PANHANDLE. SO FAR IT HAS NOT HAPPENED.
WILL CONTINUE TO MONITOR.
&&
.FIRE WEATHER...
ISSUED AT 103 AM MST SAT JAN 9 2016
NO FIRE WEATHER CONCERNS. MINIMUM AFTERNOON HUMIDITY VALUES WILL
BE ABOVE 40 PERCENT. WIDESPREAD SNOW COVER WILL EXIST WITH THE
COLD TEMPERATURES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
249 PM PST SAT JAN 9 2016
.SYNOPSIS...SCATTERED SHOWERS WILL GRADUALLY TAPER OFF THIS
EVENING. CLEARING AND COOL OVERNIGHT INTO SUNDAY MORNING. DRY ON
SUNDAY WITH BUILDING HIGH PRESSURE. NEXT FRONT APPROACHES MONDAY
BUT LOOKS TO WEAKEN WITH THE BEST CHANCE FOR LIGHT RAIN IN THE
NORTH BAY. ANOTHER STORM IS FORECAST TO ARRIVE LATE TUESDAY NIGHT
INTO WEDNESDAY WITH RAIN LIKELY.
&&
.DISCUSSION...AS OF 3:00 PM PST SATURDAY...SCATTERED SHOWERS
CONTINUE ACROSS OUR AREA. KMUX BEAM IS OVERSHOOTING QUITE A FEW OF
THEM BASED OFF OF GROUND TRUTH THAT WE ARE RECEIVING (PLEASE SEE
SFOPNSMTR FOR 24 HOUR TOTALS). IN GENERAL, COMMUNITIES HAVE PICKED
UP LESS THAN TWO TENTHS WITH SOME ISOLATED SPOTS IN THE HILLS
ABOVE 1/2". CLOUDS AND PRECIP HAVE PREVENTED TEMPS FROM WARMING UP
MUCH FROM THEIR OVERNIGHT LOWS. SHOULD END THE DAY WITH MOST SPOTS
IN THE 50S. LATEST RUN OF THE HRRR HAS RAINFALL SLOWLY ENDING
NORTH TO SOUTH LATE THIS AFTERNOON THROUGH THE EVENING. THIS GOES
ALONG WITH NAM/ECMWF/GFS THINKING. ADDITIONAL RAINFALL AMOUNTS
WILL BE LIGHT WITH THE POSSIBLE EXCEPTION OF THE SANTA LUCIAS.
THERE MORE THAN 1/4" COULD LOCALLY FALL. LOWS WILL GENERAL BE IN
THE 40S ONCE AGAIN.
A VERY WEAK SYSTEM WILL PASS THROUGH ON SUNDAY POSSIBLY BRINGING
A FEW SHOWERS TO OUR AREA -- PARTICULARLY THE SOUTHERN THIRD.
AMOUNTS WILL BE UNDER 1/10" IN ALMOST ALL CASES.
A SLIGHTLY STRONGER SYSTEM WILL THEN MOVE TO THE COAST AND BRING
ANOTHER ROUND OF RAIN BEGINNING SUNDAY NIGHT INTO MONDAY. CURRENT
TIMING BRINGS IT TO THE NORTH BY SUNDAY NIGHT THEN DOWN TO THE SF
BAY AREA MONDAY MORNING. RAIN WILL MOVE TO THE MONTEREY BAY REGION
BY LATE IN THE MORNING. RAINFALL AMOUNTS ARE FORECAST TO GENERALLY
BE 1/10" TO 1/4" WITH LOCALLY HIGHER AMOUNTS FOR THE NORTH BAY
MOUNTAINS. LIKELY THAT SANTA CLARA VALLEY DOWN THROUGH THE SALINAS
VALLEY WILL PICK UP EVEN LESS. RAIN WILL SWITCH BACK TO SHOWERS
LATER ON MONDAY.
AFTER ANOTHER BREAK FROM LATE MONDAY TO THE FIRST HALF OF TUESDAY,
ANOTHER SYSTEM WILL MOVE BACK TO OUR AREA. THIS ONE WILL LIKELY BE
THE STRONGEST OF THE WEEK WITH WIDESPREAD RAIN FORECAST LATE
TUESDAY NIGHT INTO WEDNESDAY. ALTHOUGH OVERALL DYNAMICS ARE NOT
NEARLY AS STRONG AS THE RECENT SYSTEMS, THIS SHOULD STILL BRING
1/4" TO 2/3" AMOUNTS WITH COASTAL RANGES IN THE 1-2" VALUES
(LOCALLY 3"+). RAIN MAY BE LOCALLY HEAVY AT TIMES AND PRE- FRONTAL
SOUTHERLY WINDS WILL GUST IN THE 20 TO 30 MPH IN MANY SPOTS. SOME
MODELS DO BRING THE MAIN BAND THROUGH IN THE MIDDLE OF THE DAY,
WHICH WOULD HELP TO MITIGATE RUSH HOUR ISSUES. WILL SEE WHAT THE
LATER MODELS SHOWS. RAIN WILL AGAIN SWITCH TO SHOWERS BY WEDNESDAY
EVENING OR NIGHT.
AFTER THAT POINT A PERIOD OF DRIER WEATHER IS FORECAST (THIS IS
SUPPORTED BY THE OPERATIONAL AND ENSEMBLE MODELS) AS A WEAK RIDGE
OF HIGH PRESSURE BUILDS INTO THE REGION. THIS WILL LIKELY HOLD
UNTIL AROUND SUNDAY WHEN A WEAK SYSTEM COULD BRING ANOTHER ROUND
OF LIGHT RAIN.
LONGER RANGE GUIDANCE INDICATES A RETURN TO ACTIVE WEATHER IN THE
10 TO 16 DAY RANGE. ABOVE NORMAL RAINFALL IS FORECAST.
&&
.AVIATION...AS OF 09:55 AM PST SATURDAY...A SURFACE FRONT
CONTINUES TO PASS OVER THE AREA THIS MORNING RESULTING IN
WIDESPREAD MVFR CIGS AND LIGHT RAIN. THIS FRONT APPEARS PRETTY
WEAK AND THE FORECAST MODEL SOUNDINGS ARE SHOWING CIGS SLOWLY
LOWERING BEHIND THE FRONT LATER THIS AFTERNOON...RATHER THAN THE
TYPICAL MIXING OUT BEHIND THE FRONT. OTHERWISE GENERALLY LIGHT
WINDS ARE EXPECTED AT MOST TERMINALS TODAY WITH THE EXCEPTION OF
KSNS.
VICINITY OF KSFO...MVFR CIGS ARE EXPECTED TO PREVAIL TODAY WITH
CIGS HOVERING AROUND BKN-OVC025-035. LIGHT RAIN IS EXPECTED TO
LINGER INTO THE EARLY AFTERNOON HOURS. GENERALLY LIGHT WINDS ARE
ANTICIPATED.
CONFIDENCE IS MODERATE.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS ARE EXPECTED TO
PREVAIL TODAY WITH CIGS OVC040...OCCASIONAL BKN025 WILL BE
POSSIBLE WITH LIGHT SHOWERS THROUGH 2200Z. MVFR CIGS ARE EXPECTED
BY EARLY AFTERNOON WITH A LINGERING SHOWER IN THE VICINITY OF THE
TERMINAL. GENERALLY LIGHT WINDS AT KMRY WITH MODERATE EAST
SOUTHEASTERLY WINDS AT KSNS REACHING 18 KT WITH GUSTS TO 25 KT
INTO THE EARLY AFTERNOON HOURS.
CONFIDENCE IS MODERATE.
&&
.MARINE...AS OF 3:00 PM PST SATURDAY...WINDS WILL BECOME NORTH
NORTHWEST THIS EVENING BEHIND A DEPARTING COLD FRONT. WINDS ARE
EXPECTED TO INCREASE OUT OF THE SOUTH ONCE AGAIN SUNDAY EVENING AS
THE NEXT PACIFIC STORM SYSTEM APPROACHES THE COAST. A MODERATE
SIZED LONG PERIOD WESTERLY SWELL IS ANTICIPATED TO MOVE INTO THE
WATERS SUNDAY NIGHT...RESULTING IN LARGE BREAKING WAVES NEAR
OFFSHORE REEFS AND SAND BARS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 3 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: LARRY
MARINE: LARRY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
955 AM PST SAT JAN 9 2016
.SYNOPSIS...AREAS OF LIGHT RAIN THIS MORNING WILL TURN TO
SCATTERED SHOWERS BY THE AFTERNOON. CLEARING AND COOL OVERNIGHT
INTO SUNDAY MORNING. DRY ON SUNDAY WITH BUILDING HIGH PRESSURE.
NEXT FRONT APPROACHES MONDAY BUT LOOKS TO WEAKEN WITH THE BEST
CHANCE FOR LIGHT RAIN IN THE NORTH BAY. ANOTHER STORM IS FORECAST
TO ARRIVE LATE TUESDAY NIGHT INTO WEDNESDAY WITH ANOTHER CHANCE OF
RAIN.
&&
.DISCUSSION...AS OF 8:30 AM PST SATURDAY...ALTHOUGH KMUX RADAR
SHOWS ONLY A FEW SPOTS WITH VERY LIGHT RETURNS, A RUN OF IRIS LAST
HOUR (SENT OUT AS SFOPNSMTR) SHOWS MANY LOCATIONS ACROSS OUR CWA
HAVE PICKED UP MEASURABLE PRECIPITATION. SONOMA SO FAR IS AHEAD OF
THE PACK WITH A HANDFUL ABOVE 1/3". OBVIOUSLY THE RADAR BEAM IS
OVERSHOOTING MUCH OF THE PRECIPITATION.
MADE A SMALL CHANGE TO THE FORECAST FOR THE REST OF TODAY BASED
OFF BOTH CURRENT PRECIP PLUS THE HRRR WHICH KEEPS SCATTERED
SHOWERS THROUGH ALL OF THE CWA UNTIL LATE IN THE AFTERNOON. HRRR
ALSO SHOWS SOME SCATTERED SHOWERS CONTINUING THROUGH THE EVENING
FOR THE SOUTHERN THIRD OF OUR REGION. HIGHER POP VALUES PLUS
UPDATED WEATHER AN QPF GRIDS HAVE BEEN SENT OUT.
12Z GFS CURRENTLY COMING IN IS CLOSE TO THE 0Z ECMWF FOR THE
STRONGEST SYSTEM NEXT WEEK (LATE TUESDAY INTO WEDNESDAY). LATEST
TRENDS ARE WETTER, SO UNLESS THE ECMWF TAKES AN UNEXPECTED TURN,
POPS WILL BE INCREASED FOR THAT PERIOD. OTHER SYSTEMS DURING THE
WEEK APPEAR TO BE VERY MINOR AT THIS TIME.
.PREVIOUS DISCUSSION...ONLY GETTING SOME LIGHT RAIN REPORTS THIS
MORNING WITH WEAK SYSTEM MOVING ONSHORE. RAIN TOTALS SO FAR
GENERALLY A FEW HUNDREDTHS TO AROUND A TENTH OF AN INCH. EXPECT
SCATTERED LIGHT RAIN OR SHOWERS TO CONTINUE THIS MORNING BUT THEN
BE ON THE DECREASE THIS AFTERNOON. IR SATELLITE SHOWS NO COLD AIR
ASSOCIATED ALOFT WITH THIS SYSTEM WITH WARMING CLOUD TOPS
SUGGESTING A WEAKENING UPPER LOW AS HIGH PRESSURE TRIES TO BUILD
ON THE BACKSIDE. LOOK FOR PARTLY CLOUDY SKIES AND SEASONABLY COOL
LOWS TONIGHT IN THE UPPER 30S AND 40S.
SUNDAY LOOKS LIKE THE NICER DAY OF THE WEEKEND WITH DRY WEATHER
FORECAST BUT PROBABLY ONLY FILTERED SUNSHINE WITH A COMBINATION OF
LINGERING LOW AND HIGH LEVEL CLOUD DECKS.
NEXT SYSTEM TRIES TO KNOCK DOWN THE RIDGE ON MONDAY WITH ANOTHER
CHANCE OF LIGHT RAIN...BUT MODEL TRENDS HAVE BEEN DRIER AND KEEP
THE BEST CHANCE OF RAIN NOW CONFINED NORTH OF THE GOLDEN GATE. IF
12Z RUNS KEEP THIS TREND WILL HAVE TO TRIM BACK POPS FOR THE SOUTH
BAY AND MONTEREY BAY REGION ON MONDAY. EITHER WAY ANY RAIN WITH
THE MONDAY SYSTEM LOOKS LIGHT EVEN FOR THE NORTH BAY.
MIDWEEK SYSTEM IS NOW TIMED SLIGHTLY FASTER TO ARRIVE LATER
TUESDAY EVENING INTO WEDNESDAY. ECMWF AND GFS STILL SHOWING A
LOW TO MODERATE STRENGTH SYSTEM MOVING ONSHORE...WITH THE GFS
SLIGHTLY MORE ROBUST IN TERMS OF QPF AND ASSOCIATED JET ENERGY AND
COLD ADVECTION ALOFT.
PATTERN REMAINS PROGRESSIVE WITH DRY CONDITIONS SUGGESTED FOR
THURSDAY AND FRIDAY AND POSSIBLY INTO SATURDAY. HOWEVER GENERAL
MODEL CONSENSUS FOR CONTINUED RAIN CHANCES BY NEXT MLK WEEKEND.
SIMILAR TO THIS WEEK EXPECT TO SEE SOME SIGNIFICANT RUN TO RUN
MODEL CHANGES IN THIS PROGRESSIVE AND DYNAMIC PATTERN. OVERALL
IDEA IS CONTINUED RAIN CHANCES BUT NO BIG STORMS ON THE
HORIZON.
&&
.AVIATION...AS OF 09:55 AM PST SATURDAY...A SURFACE FRONT
CONTINUES TO PASS OVER THE AREA THIS MORNING RESULTING IN
WIDESPREAD MVFR CIGS AND LIGHT RAIN. THIS FRONT APPEARS PRETTY
WEAK AND THE FORECAST MODEL SOUNDINGS ARE SHOWING CIGS SLOWLY
LOWERING BEHIND THE FRONT LATER THIS AFTERNOON...RATHER THAN THE
TYPICAL MIXING OUT BEHIND THE FRONT. OTHERWISE GENERALLY LIGHT
WINDS ARE EXPECTED AT MOST TERMINALS TODAY WITH THE EXCEPTION OF
KSNS.
VICINITY OF KSFO...MVFR CIGS ARE EXPECTED TO PREVAIL TODAY WITH
CIGS HOVERING AROUND BKN-OVC025-035. LIGHT RAIN IS EXPECTED TO
LINGER INTO THE EARLY AFTERNOON HOURS. GENERALLY LIGHT WINDS ARE
ANTICIPATED.
CONFIDENCE IS MODERATE.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS ARE EXPECTED TO
PREVAIL TODAY WITH CIGS OVC040...OCCASIONAL BKN025 WILL BE
POSSIBLE WITH LIGHT SHOWERS THROUGH 2200Z. MVFR CIGS ARE EXPECTED
BY EARLY AFTERNOON WITH A LINGERING SHOWER IN THE VICINITY OF THE
TERMINAL. GENERALLY LIGHT WINDS AT KMRY WITH MODERATE EAST
SOUTHEASTERLY WINDS AT KSNS REACHING 18 KT WITH GUSTS TO 25 KT
INTO THE EARLY AFTERNOON HOURS.
CONFIDENCE IS MODERATE.
&&
.MARINE...AS OF 08:50 AM PST SATURDAY...A COLD FRONT IS PASSING
OVER THE COASTAL WATERS TODAY. EXPECT BREEZY SOUTH EASTERLY WINDS
THIS MORNING AHEAD OF THE FRONT WITH WINDS BECOMING WESTERLY LATER
TODAY AS THE FRONT MOVES ONSHORE. WINDS WILL INCREASE OUT OF THE
SOUTH ONCE AGAIN SUNDAY EVENING AS THE NEXT PACIFIC STORM SYSTEM
APPROACHES THE COAST.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
&&
$$
PUBLIC FORECAST: BELL/RWW
AVIATION: LARRY
MARINE: LARRY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
851 AM PST SAT JAN 9 2016
.SYNOPSIS...AREAS OF LIGHT RAIN THIS MORNING WILL TURN TO
SCATTERED SHOWERS BY THE AFTERNOON. CLEARING AND COOL OVERNIGHT
INTO SUNDAY MORNING. DRY ON SUNDAY WITH BUILDING HIGH PRESSURE.
NEXT FRONT APPROACHES MONDAY BUT LOOKS TO WEAKEN WITH THE BEST
CHANCE FOR LIGHT RAIN IN THE NORTH BAY. ANOTHER STORM IS FORECAST
TO ARRIVE LATE TUESDAY NIGHT INTO WEDNESDAY WITH ANOTHER CHANCE OF
RAIN.
&&
.DISCUSSION...AS OF 8:30 AM PST SATURDAY...ALTHOUGH KMUX RADAR
SHOWS ONLY A FEW SPOTS WITH VERY LIGHT RETURNS, A RUN OF IRIS LAST
HOUR (SENT OUT AS SFOPNSMTR) SHOWS MANY LOCATIONS ACROSS OUR CWA
HAVE PICKED UP MEASURABLE PRECIPITATION. SONOMA SO FAR IS AHEAD OF
THE PACK WITH A HANDFUL ABOVE 1/3". OBVIOUSLY THE RADAR BEAM IS
OVERSHOOTING MUCH OF THE PRECIPITATION.
MADE A SMALL CHANGE TO THE FORECAST FOR THE REST OF TODAY BASED
OFF BOTH CURRENT PRECIP PLUS THE HRRR WHICH KEEPS SCATTERED
SHOWERS THROUGH ALL OF THE CWA UNTIL LATE IN THE AFTERNOON. HRRR
ALSO SHOWS SOME SCATTERED SHOWERS CONTINUING THROUGH THE EVENING
FOR THE SOUTHERN THIRD OF OUR REGION. HIGHER POP VALUES PLUS
UPDATED WEATHER AN QPF GRIDS HAVE BEEN SENT OUT.
12Z GFS CURRENTLY COMING IN IS CLOSE TO THE 0Z ECMWF FOR THE
STRONGEST SYSTEM NEXT WEEK (LATE TUESDAY INTO WEDNESDAY). LATEST
TRENDS ARE WETTER, SO UNLESS THE ECMWF TAKES AN UNEXPECTED TURN,
POPS WILL BE INCREASED FOR THAT PERIOD. OTHER SYSTEMS DURING THE
WEEK APPEAR TO BE VERY MINOR AT THIS TIME.
.PREVIOUS DISCUSSION...ONLY GETTING SOME LIGHT RAIN REPORTS THIS
MORNING WITH WEAK SYSTEM MOVING ONSHORE. RAIN TOTALS SO FAR
GENERALLY A FEW HUNDREDTHS TO AROUND A TENTH OF AN INCH. EXPECT
SCATTERED LIGHT RAIN OR SHOWERS TO CONTINUE THIS MORNING BUT THEN
BE ON THE DECREASE THIS AFTERNOON. IR SATELLITE SHOWS NO COLD AIR
ASSOCIATED ALOFT WITH THIS SYSTEM WITH WARMING CLOUD TOPS
SUGGESTING A WEAKENING UPPER LOW AS HIGH PRESSURE TRIES TO BUILD
ON THE BACKSIDE. LOOK FOR PARTLY CLOUDY SKIES AND SEASONABLY COOL
LOWS TONIGHT IN THE UPPER 30S AND 40S.
SUNDAY LOOKS LIKE THE NICER DAY OF THE WEEKEND WITH DRY WEATHER
FORECAST BUT PROBABLY ONLY FILTERED SUNSHINE WITH A COMBINATION OF
LINGERING LOW AND HIGH LEVEL CLOUD DECKS.
NEXT SYSTEM TRIES TO KNOCK DOWN THE RIDGE ON MONDAY WITH ANOTHER
CHANCE OF LIGHT RAIN...BUT MODEL TRENDS HAVE BEEN DRIER AND KEEP
THE BEST CHANCE OF RAIN NOW CONFINED NORTH OF THE GOLDEN GATE. IF
12Z RUNS KEEP THIS TREND WILL HAVE TO TRIM BACK POPS FOR THE SOUTH
BAY AND MONTEREY BAY REGION ON MONDAY. EITHER WAY ANY RAIN WITH
THE MONDAY SYSTEM LOOKS LIGHT EVEN FOR THE NORTH BAY.
MIDWEEK SYSTEM IS NOW TIMED SLIGHTLY FASTER TO ARRIVE LATER
TUESDAY EVENING INTO WEDNESDAY. ECMWF AND GFS STILL SHOWING A
LOW TO MODERATE STRENGTH SYSTEM MOVING ONSHORE...WITH THE GFS
SLIGHTLY MORE ROBUST IN TERMS OF QPF AND ASSOCIATED JET ENERGY AND
COLD ADVECTION ALOFT.
PATTERN REMAINS PROGRESSIVE WITH DRY CONDITIONS SUGGESTED FOR
THURSDAY AND FRIDAY AND POSSIBLY INTO SATURDAY. HOWEVER GENERAL
MODEL CONSENSUS FOR CONTINUED RAIN CHANCES BY NEXT MLK WEEKEND.
SIMILAR TO THIS WEEK EXPECT TO SEE SOME SIGNIFICANT RUN TO RUN
MODEL CHANGES IN THIS PROGRESSIVE AND DYNAMIC PATTERN. OVERALL
IDEA IS CONTINUED RAIN CHANCES BUT NO BIG STORMS ON THE
HORIZON.
&&
.AVIATION...AS OF 3:55 AM PST SATURDAY... SCATTERED TO WIDESPREAD
RAIN SHOWERS ACROSS THE REGION THIS MORNING BRINGING -SHRA TO MOST
TAF SITES. CIGS ARE GRADUALLY DESCENDING INTO THE UPPER MVFR
RANGE... IE 2500-4000 FT AGL AS FRONT PUSHES INLAND. WINDS WILL
GENERALLY BE LIGHT SOUTHEAST THROUGH THE FORECAST PERIOD. RAIN
SHOWERS WILL BECOME ISOLATED TO SCATTERED AFTER 00Z AND END FOR
MOST AREAS BY 03Z.
VICINITY OF KSFO... -SHRA THROUGH 20Z SAT... THEN LINGERING VCSH
THROUGH 00-03Z SUN. WIND GENERALLY LIGHT AND SOUTHEASTERLY.
INTERMITTENT VFR/MVFR CIGS.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS... -SHRA THROUGH 20Z SAT... THEN
LINGERING VCSH THROUGH 00-03Z SUN. WINDS GENERALLY SOUTHEASTERLY
AND LIGHT EXCEPT IN THE SALINAS VALLEY... WHERE BREEZY SOUTHEAST
WINDS WILL PERSIST THROUGH 21Z. INTERMITTENT VFR/MVFR CIGS.
&&
.MARINE...AS OF 08:50 AM PST SATURDAY...A COLD FRONT IS PASSING
OVER THE COASTAL WATERS TODAY. EXPECT BREEZY SOUTH EASTERLY WINDS
THIS MORNING AHEAD OF THE FRONT WITH WINDS BECOMING WESTERLY LATER
TODAY AS THE FRONT MOVES ONSHORE. WINDS WILL INCREASE OUT OF THE
SOUTH ONCE AGAIN SUNDAY EVENING AS THE NEXT PACIFIC STORM SYSTEM
APPROACHES THE COAST.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
&&
$$
PUBLIC FORECAST: BELL/RWW
AVIATION: DRP
MARINE: LARRY
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
831 AM PST SAT JAN 9 2016
.SYNOPSIS...AREAS OF LIGHT RAIN THIS MORNING WILL TURN TO
SCATTERED SHOWERS BY THE AFTERNOON. CLEARING AND COOL OVERNIGHT
INTO SUNDAY MORNING. DRY ON SUNDAY WITH BUILDING HIGH PRESSURE.
NEXT FRONT APPROACHES MONDAY BUT LOOKS TO WEAKEN WITH THE BEST
CHANCE FOR LIGHT RAIN IN THE NORTH BAY. ANOTHER STORM IS FORECAST
TO ARRIVE LATE TUESDAY NIGHT INTO WEDNESDAY WITH ANOTHER CHANCE OF
RAIN.
&&
.DISCUSSION...AS OF 8:30 AM PST SATURDAY...ALTHOUGH KMUX RADAR
SHOWS ONLY A FEW SPOTS WITH VERY LIGHT RETURNS, A RUN OF IRIS LAST
HOUR (SENT OUT AS SFOPNSMTR) SHOWS MANY LOCATIONS ACROSS OUR CWA
HAVE PICKED UP MEASURABLE PRECIPITATION. SONOMA SO FAR IS AHEAD OF
THE PACK WITH A HANDFUL ABOVE 1/3". OBVIOUSLY THE RADAR BEAM IS
OVERSHOOTING MUCH OF THE PRECIPITATION.
MADE A SMALL CHANGE TO THE FORECAST FOR THE REST OF TODAY BASED
OFF BOTH CURRENT PRECIP PLUS THE HRRR WHICH KEEPS SCATTERED
SHOWERS THROUGH ALL OF THE CWA UNTIL LATE IN THE AFTERNOON. HRRR
ALSO SHOWS SOME SCATTERED SHOWERS CONTINUING THROUGH THE EVENING
FOR THE SOUTHERN THIRD OF OUR REGION. HIGHER POP VALUES PLUS
UPDATED WEATHER AN QPF GRIDS HAVE BEEN SENT OUT.
12Z GFS CURRENTLY COMING IN IS CLOSE TO THE 0Z ECMWF FOR THE
STRONGEST SYSTEM NEXT WEEK (LATE TUESDAY INTO WEDNESDAY). LATEST
TRENDS ARE WETTER, SO UNLESS THE ECMWF TAKES AN UNEXPECTED TURN,
POPS WILL BE INCREASED FOR THAT PERIOD. OTHER SYSTEMS DURING THE
WEEK APPEAR TO BE VERY MINOR AT THIS TIME.
.PREVIOUS DISCUSSION...ONLY GETTING SOME LIGHT RAIN REPORTS THIS
MORNING WITH WEAK SYSTEM MOVING ONSHORE. RAIN TOTALS SO FAR
GENERALLY A FEW HUNDREDTHS TO AROUND A TENTH OF AN INCH. EXPECT
SCATTERED LIGHT RAIN OR SHOWERS TO CONTINUE THIS MORNING BUT THEN
BE ON THE DECREASE THIS AFTERNOON. IR SATELLITE SHOWS NO COLD AIR
ASSOCIATED ALOFT WITH THIS SYSTEM WITH WARMING CLOUD TOPS
SUGGESTING A WEAKENING UPPER LOW AS HIGH PRESSURE TRIES TO BUILD
ON THE BACKSIDE. LOOK FOR PARTLY CLOUDY SKIES AND SEASONABLY COOL
LOWS TONIGHT IN THE UPPER 30S AND 40S.
SUNDAY LOOKS LIKE THE NICER DAY OF THE WEEKEND WITH DRY WEATHER
FORECAST BUT PROBABLY ONLY FILTERED SUNSHINE WITH A COMBINATION OF
LINGERING LOW AND HIGH LEVEL CLOUD DECKS.
NEXT SYSTEM TRIES TO KNOCK DOWN THE RIDGE ON MONDAY WITH ANOTHER
CHANCE OF LIGHT RAIN...BUT MODEL TRENDS HAVE BEEN DRIER AND KEEP
THE BEST CHANCE OF RAIN NOW CONFINED NORTH OF THE GOLDEN GATE. IF
12Z RUNS KEEP THIS TREND WILL HAVE TO TRIM BACK POPS FOR THE SOUTH
BAY AND MONTEREY BAY REGION ON MONDAY. EITHER WAY ANY RAIN WITH
THE MONDAY SYSTEM LOOKS LIGHT EVEN FOR THE NORTH BAY.
MIDWEEK SYSTEM IS NOW TIMED SLIGHTLY FASTER TO ARRIVE LATER
TUESDAY EVENING INTO WEDNESDAY. ECMWF AND GFS STILL SHOWING A
LOW TO MODERATE STRENGTH SYSTEM MOVING ONSHORE...WITH THE GFS
SLIGHTLY MORE ROBUST IN TERMS OF QPF AND ASSOCIATED JET ENERGY AND
COLD ADVECTION ALOFT.
PATTERN REMAINS PROGRESSIVE WITH DRY CONDITIONS SUGGESTED FOR
THURSDAY AND FRIDAY AND POSSIBLY INTO SATURDAY. HOWEVER GENERAL
MODEL CONSENSUS FOR CONTINUED RAIN CHANCES BY NEXT MLK WEEKEND.
SIMILAR TO THIS WEEK EXPECT TO SEE SOME SIGNIFICANT RUN TO RUN
MODEL CHANGES IN THIS PROGRESSIVE AND DYNAMIC PATTERN. OVERALL
IDEA IS CONTINUED RAIN CHANCES BUT NO BIG STORMS ON THE
HORIZON.
&&
.AVIATION...AS OF 3:55 AM PST SATURDAY... SCATTERED TO WIDESPREAD
RAIN SHOWERS ACROSS THE REGION THIS MORNING BRINGING -SHRA TO MOST
TAF SITES. CIGS ARE GRADUALLY DESCENDING INTO THE UPPER MVFR
RANGE... IE 2500-4000 FT AGL AS FRONT PUSHES INLAND. WINDS WILL
GENERALLY BE LIGHT SOUTHEAST THROUGH THE FORECAST PERIOD. RAIN
SHOWERS WILL BECOME ISOLATED TO SCATTERED AFTER 00Z AND END FOR
MOST AREAS BY 03Z.
VICINITY OF KSFO... -SHRA THROUGH 20Z SAT... THEN LINGERING VCSH
THROUGH 00-03Z SUN. WIND GENERALLY LIGHT AND SOUTHEASTERLY.
INTERMITTENT VFR/MVFR CIGS.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS... -SHRA THROUGH 20Z SAT... THEN
LINGERING VCSH THROUGH 00-03Z SUN. WINDS GENERALLY SOUTHEASTERLY
AND LIGHT EXCEPT IN THE SALINAS VALLEY... WHERE BREEZY SOUTHEAST
WINDS WILL PERSIST THROUGH 21Z. INTERMITTENT VFR/MVFR CIGS.
&&
.MARINE...AS OF 08:18 AM PST SATURDAY...BREEZY SOUTHERLY WINDS
EARLY THIS MORNING WILL SHIFT TO THE WEST AND WEAKEN LATER TODAY.
WINDS INCREASE LATE THIS WEEKEND AHEAD OF THE NEXT PACIFIC STORM
SYSTEM. MODERATE WESTERLY SWELL WILL CONTINUE TO DIMINISH TONIGHT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 9 AM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 9 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
&&
$$
PUBLIC FORECAST: BELL/RWW
AVIATION: DRP
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
100 PM EST SAT JAN 9 2016
.Aviation...
[Through 18Z Sunday] IFR ceilings and MVFR visibility will be the
most likely conditions that accompany a band of showers as it
traverses the forecast area from west to east this afternoon and
evening. Thunderstorms should be limited to areas along and south
of I-10 and perhaps the VLD area. Once the showers pass, a brief
return to LIFR ceilings is possible until later tonight when
conditions will improve to MVFR with a wind shift to the
northwest. These northwest winds will be gusty on Sunday.
&&
.Prev Discussion [920 AM EST]...
.Near Term [Through Today]...
Water vapor imagery shows and upper low over Oklahoma this morning.
Surface analysis shows weakening low pressure over Arkansas with
another low developing closer to the Gulf of Mexico (GOMEX) near
coastal Louisiana. A warm front is developing southeastward from
this low over the eastern GOMEX southwest of our marine area.
Regional radars show a cluster of thunderstorms tracking eastward
south of the MS/AL coastline. This is a remnant of a more organized
squall line that tracked across the Mississippi River overnight. The
12Z KTAE sounding sampled the 145-kt jet stream that extends across
the northern GOMEX. The sounding also shows the stable air mass is
place across the Big Bend.
Little has changed in our overall assessment of today`s severe
weather potential. We will find ourselves in a high-shear, low-CAPE
environment that is typical when frontal systems traverse the Gulf
Coast during winter. Deep layer shear values will be in the
impressive 70-85 knot range, but remain largely displaced northward
from the deep moisture and instability over the GOMEX. There is a
narrow zone where we could see sufficient overlap of shear and
instability to allow severe storms to develop. That includes our
coastal counties and marine area. The locally developed DVD severe
weather parameter from the 13Z RAP indicates this will mainly occur
in the afternoon and evening hours once the surface low tracks more
toward the northeast allowing the warm front to edge closer to the
coast. ECAM probabilities for severe gusts and strong updraft
helicity has been scaled back from what we were seeing yesterday to
include the same geographic threat area and SPC`s marginal risk
areas generally depicts this as well. The threat will be for
isolated damaging wind gusts and perhaps a tornado.
.Short Term [Tonight Through Monday]...
The shortwave currently over central Texas is forecast to be over
the Mississippi and Tennessee valleys by this evening and embedded
within the large, broad full CONUS trough. At the surface, low
pressure centered over the Ohio and Tennessee valleys is forecast
to move through the Midwest tonight and the Northeast on Sunday.
Much, if not all of the day`s convection will likely be through
the region by this evening. Should convection linger into the
evening a bit it will primarily be focused across the southeast
Big Bend of Florida, with a weakening rain shield over south-
central Georgia. The potential for an isolated severe storm will
still exist across primarily Taylor, Lafayette, and Dixie counties
early this evening. The primary threat with any supercells that
develop will be tornadoes and damaging winds.
After tonight, surface ridging will build into the Southeast
behind a cold front. Temperatures will fall to below seasonal
averages Sunday through Monday, with highs ranging from the upper
40s across southeast Alabama tomorrow, to the mid 60s across the
southeast Big Bend of Florida. Low to mid 50s will be common
area-wide on Monday. CAA from Sunday will linger into Sunday
night, forcing lows into the upper 20s across southeast Alabama
and southwest Georgia, up to the upper 30s across the southeast
Big Bend. Wind chill readings will essentially make it feel like
30 degrees and below, with some spots nearing the 20 degree wind
chill mark in the coldest spots.
.Long Term [Monday Night Through Saturday]...
The below normal temperatures will continue through Thursday as
another cold front (with no rain), moves through the region on
Tuesday. Monday night will be the closest to a radiational cooling
event, with little to no wind. CAA and wind chills are expected
again on Tuesday and Wednesday nights. Highs will remain solidly
in the 50s through Thursday, with overnight lows in the 30s. Wind
chills on Tues/Wed nights will likely only fall into the middle
20s across southeast Alabama and southwest Georgia.
Thursday through Saturday, models are essentially split and
cannot agree on placement or strength of a developing Gulf low.
Though, moderating temperatures and a chance for rain will likely
return by the end of the period.
.Marine...
Cautionary level winds are expected through Sunday night, ahead
of, and in the wake of a passing cold front. Another uptick in
winds will be possible behind a cold front early next week, though
at this time appear to remain below headline levels. Finally, late
next week there is the potential for another enhancement in winds
and seas associated with a developing Gulf low.
.Fire Weather...
With a moist air mass in place, there are no fire weather
concerns for this weekend. On Monday, a very dry air mass will
invade the region. Red Flag conditions are a possibility on
Monday.
.Hydrology...
The low pressure system today will, on average, bring less than a
quarter of an inch of rain across southeast Alabama and south
Georgia. Across north Florida, a half inch will be more common.
Isolated rainfall totals between 1 to 2 inches will be possible
should a strong thunderstorm reach land areas south of interstate
10. In general, this event is not expected to have a significant
impact on river levels or trends. The lower Choctawhatchee and
Apalachicola rivers remain at moderate flood levels this morning.
Though levels are steadily lowering across these rivers, they`ll
likely remain in flood for several more days. The lower Flint
River will drop below flood stage this evening.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 54 56 34 55 31 / 20 0 0 0 0
Panama City 54 55 36 52 38 / 10 0 0 0 0
Dothan 47 49 29 52 30 / 30 0 0 0 0
Albany 50 52 29 52 30 / 40 0 0 0 0
Valdosta 55 57 33 55 31 / 60 0 0 0 0
Cross City 59 64 39 59 33 / 60 0 0 0 0
Apalachicola 57 58 39 54 38 / 10 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through late tonight FOR Coastal Bay-
Coastal Franklin-Coastal Gulf-South Walton.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...WOOL
SHORT TERM...HARRIGAN
LONG TERM...HARRIGAN
AVIATION...WOOL
MARINE...HARRIGAN
FIRE WEATHER...MCDERMOTT
HYDROLOGY...HARRIGAN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1129 AM MST SAT JAN 9 2016
.UPDATE...
ISSUED AT 1129 AM MST SAT JAN 9 2016
UPDATE ISSUED TO REMOVE MENTION OF MORNING FLURRIES/SNOW SHOWERS
AND TO ADJUST CLOUD COVER BASED ON LATEST VISIBLE SATELLITE
TREND. CURRENTLY THE CWA IS SEEING TEMPS IN THE 20S WITH A
NORTHERLY FETCH UNDER MIXED SKY COVER. CLOUD DECK OVER PAST FEW
HOURS HAS THINNED IN SPOTS ALLOWING FOR MORE SUN TO REACH THE
AREA. DO EXPECT TREND TO CONTINUE THRU THE AFTERNOON HOURS SO
HAVE MENTIONED PARTLY TO MOSTLY SUNNY SKIES. WITH THIS ADDITIONAL
CLEARING...RADAR ECHOES HAVE BEEN TEMPERED...SO HAVE REMOVED
PRECIP. REST OF FORECAST ON TRACK.
&&
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 223 AM MST SAT JAN 9 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS A
LONGWAVE TROUGH ACROSS THE CENTRAL US ACROSS THE GLD CWA WITH A
CLOSED CENTER ROTATING OVER WESTERN OK TO THE SOUTHEAST. AN
AMPLIFIED RIDGE IN IN PLACE ACROSS THE WESTERN US UPSTREAM. AT THE
SURFACE CANADIAN HIGH PRESSURE EXTENDS SOUTH ACROSS THE NORTHERN
PLAINS ACROSS OUR CWA.
THIS MORNING-THIS AFTERNOON...WEAK FORCING BENEATH LONGWAVE TROUGH
HAS COMBINED WITH A SATURATED LAYER FROM 925-700 MB AND STEEP LOW
LOW LEVEL LAPSE RATES TO SUPPORT POCKETS OF FLURRIES ACROSS THE
AREA. AS THE CLOSED UPPER LOW TO THE SOUTHEAST MOVES EAST AND
SHORTWAVE RIDGING BUILDS INTO THE ROCKIES MUCH DRIER/STABLE AIR
SHOULD LEAD TO THIS ACTIVITY DISSIPATING. THERE COULD STILL BE A FEW
FLURRIES POSSIBLE THROUGH MIDDAY...HOWEVER OVERALL TREND SHOULD BE
FOR THIS TO END DURING THE MORNING HOURS. CAA WILL CONTINUE THIS
MORNING THROUGH THE AFTERNOON...AND IN LOCATIONS WITH PERSISTENT
CLOUD COVER WE COULD SEE HIGHS STRUGGLE TO REACH 20F. THERE IS SOME
INDICATION THAT WE COULD SEE BREAKS IN CLOUD COVER THIS
AFTERNOON...WHICH MAY ALLOW TEMPS (MAINLY SOUTH OF I-70) TO REACH
30F.
TONIGHT-MONDAY NIGHT...AMPLIFIED NW FLOW WILL BE IN PLACE ACROSS THE
PLAINS WITH MAIN STORM TRACK SPLIT AROUND OUR CWA. THERE WILL BE A
SERIES OF CLIPPERS ROTATING THROUGH THE MEAN FLOW...HOWEVER ANY
IMPACT ON SENSIBLE WEATHER OVER OUR CWA SHOULD BE LIMITED TO
INCREASES IN HIGH CLOUD COVER THROUGH THESE PERIODS.
REGARDING TEMPERATURES...THERE WILL BE A SLIGHT MODERATION IN THE
AIR MASS TONIGHT...HOWEVER WITH CANADIAN HIGH PRESSURE STILL BE A
STRONG INFLUENCE ON OUR TEMPS. THE QUESTION IS CLOUD COVER AND TDS AS
WITH CLEARING SKIES AND TDS ON DRIER END OF GUIDANCE COULD SUPPORT
LOWS NEAR ZERO AT SOME LOCATIONS. GUIDANCE SHOWS HIGH CLOUD COVER
INCREASING LATE WHICH LOWERS CONFIDENCE IN IDEAL RADIATIONAL
CONDITIONS. WEAK LEE TROUGH DEVELOPS IN EASTERN COLORADO/WYOMING
WITH DOWNSLOPE FLOW SUPPORTING CONTINUED MODERATION OF THE AIR MASS
THROUGH MONDAY. UPSTREAM SNOW FIELD AND PERIODS OF CLOUD COVER (AND
WINDS DURING THE NIGHT PERIODS) ALL LOWER CONFIDENCE IN TEMPS
THROUGH THE PERIODS. I STUCK WITH SIMILAR TRENDS AS PREVIOUS
FORECAST WITH HIGHS RETURNING TO SEASONAL VALUES AROUND 42 BY
MONDAY...AND OVERNIGHT LOWS IN THE SINGLE DIGITS (WEST) TO THE
TEENS(EAST). A QUICK MOVING SHORTWAVE TROUGH AND PASSING COLD FRONT
COMPLICATES LOWS MONDAY NIGHT...THOUGH WITH CAA IN PLACE EVEN CLOUD
COVER MAY NOT KEEP LOWS FROM DROPPING INTO THE TEENS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 117 AM MST SAT JAN 9 2016
MODELS CONTINUE TO NOT DO VERY WELL IN THIS TIME PERIOD. A LOT OF
SPREAD REMAINS NOT ONLY WITH THE DETERMINISTIC OUTPUT BUT ALSO THE
ENSEMBLES. MODELS DISAGREE ON HOW AMPLIFIED OR NOT THE FLOW IS WITH
THE OUTPUT OUT OF PHASE BY THE END OF THE PERIOD. ESSENTIALLY THE
FLOW REMAINS WEST TO NORTHWEST AND SOMETIMES EVEN MORE NORTH.
SO MOST OF THE WAVES GOING THROUGH LOOK TO BE OPEN AND FAST MOVING.
SO LITTLE TO NO CHANCE TO GET PRECIPITATION IN THIS SCENARIO. ONE OF
THOSE SHORTWAVES MOVES THROUGH IN THE THURSDAY TO FRIDAY TIME FRAME
AND BRINGS IN A MUCH COLDER AIR MASS. THE COMBINATION OF THE
SHORTWAVE AND COLD AIR ADVECTION SHOULD BE ABLE TO PRODUCE A SMALL
CHANCE OF LIGHT SNOW WHICH IS WHAT THE CRH_INIT GAVE ME FOR FRIDAY
WHICH IS REASONABLE.
WHAT LOOKS TO BE THE MOST UNCERTAIN IS THE TEMPERATURE FORECAST. IN
THIS FLOW COULD POSSIBLY GET A COLD SURGE/BACK DOOR COLD FRONT
MOVING INTO THE AREA. THE INIT GAVE ME WARMER TEMPERATURES IN THE
MIDDLE TO UPPER 40S ON WEDNESDAY AND THURSDAY...WHICH I WILL LEAVE
ALONE FOR NOW DUE TO MODEL DISAGREEMENT...BUT THERE IS DEFINITE
POTENTIAL FOR COLDER TEMPERATURES THOSE DAYS...DEPENDING OF COURSE
ON WHICH MODELS MID/UPPER SOLUTION WORKS OUT.
FRIDAY DEFINITELY LOOKS COLDER AND EVEN INTO THE REMAINDER OF NEXT
WEEKEND. THE PATTERN THE MODEL OUTPUT IS SHOWING...EVEN THOUGH
SHOWING DIFFERENCES...IS CONDUCIVE TO MUCH COLDER TEMPERATURES.
OVERALL NO CHANGES WILL BE MADE TO THE CRH_INIT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1028 AM MST SAT JAN 9 2016
FOR KGLD...WILL SEE A MVFR/VFR MIX IN CEILINGS THRU 20Z THEN VFR
CONDITIONS. BY 07Z SUNDAY...MVFR AGAIN THRU 12Z AS FOG TO 3SM AND
CEILINGS DROP TO OVC010. BY 12Z SUNDAY VFR PREVAILS. WINDS NORTH
AROUND 10KTS THRU 00Z SUNDAY...THEN LGT/VAR THRU 12Z BECOMING SW
AROUND 10KTS.
FOR KMCK...WILL SEE VFR CONDITIONS WITH CEILINGS RANGING
BKN035-150. BY 06Z SUNDAY...MVFR CONDITIONS IN 3SM FOR FOG AND
CEILINGS OVC010. BY 13Z VFR SKY CONDITIONS. WINDS NNE AROUND 10KTS
BECM LGT/VAR BY 00Z SUNDAY. BY 13Z SUNDAY...SW AROUND 10KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1028 AM MST SAT JAN 9 2016
.UPDATE...
ISSUED AT 510 AM MST SAT JAN 9 2016
UPDATED TO ADD SLIGHT CHANCE POPS TO EASTERN CWA AND PATCHY FOG
TO EASTERN COLORADO. STRONGER RADAR RETURNS ARE EVIDENT AS BAND OF
SNOW DEVELOPED NEAR DEFORMATION ZONE ON NW SIDE OF UPPER LOW
CENTER. PROGRESSION OF UPPER LOW WILL CONTINUE TO BE TOWARDS THE
SOUTHEAST...HOWEVER THERE COULD BE STILL BE SEVERAL HOURS OF LIGHT
MEASURABLE SNOW (DUSTING) IN OUR EASTERN COUNTIES. OTHERWISE
FLURRIES/NON MEASURABLE SHOULD BE EXPECTED ACROSS REST OF CWA.
SHORT RANGE GUIDANCE STILL INDICATING POSSIBILITY FOR VIS TO DROP
TO ONE MILE OR LESS IN OUR FAR SOUTHEAST DUE TO FOG...THOUGH SO
FAR VIS HAS BEEN 3-6SM. ADDED PATCHY FOG MENTION IN COLORADO
COUNTIES TO ACCOUNT FOR POSSIBILITY.
&&
.SHORT TERM...(THIS MORNING THROUGH MONDAY NIGHT)
ISSUED AT 223 AM MST SAT JAN 9 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS A
LONGWAVE TROUGH ACROSS THE CENTRAL US ACROSS THE GLD CWA WITH A
CLOSED CENTER ROTATING OVER WESTERN OK TO THE SOUTHEAST. AN
AMPLIFIED RIDGE IN IN PLACE ACROSS THE WESTERN US UPSTREAM. AT THE
SURFACE CANADIAN HIGH PRESSURE EXTENDS SOUTH ACROSS THE NORTHERN
PLAINS ACROSS OUR CWA.
THIS MORNING-THIS AFTERNOON...WEAK FORCING BENEATH LONGWAVE TROUGH
HAS COMBINED WITH A SATURATED LAYER FROM 925-700 MB AND STEEP LOW
LOW LEVEL LAPSE RATES TO SUPPORT POCKETS OF FLURRIES ACROSS THE
AREA. AS THE CLOSED UPPER LOW TO THE SOUTHEAST MOVES EAST AND
SHORTWAVE RIDGING BUILDS INTO THE ROCKIES MUCH DRIER/STABLE AIR
SHOULD LEAD TO THIS ACTIVITY DISSIPATING. THERE COULD STILL BE A FEW
FLURRIES POSSIBLE THROUGH MIDDAY...HOWEVER OVERALL TREND SHOULD BE
FOR THIS TO END DURING THE MORNING HOURS. CAA WILL CONTINUE THIS
MORNING THROUGH THE AFTERNOON...AND IN LOCATIONS WITH PERSISTENT
CLOUD COVER WE COULD SEE HIGHS STRUGGLE TO REACH 20F. THERE IS SOME
INDICATION THAT WE COULD SEE BREAKS IN CLOUD COVER THIS
AFTERNOON...WHICH MAY ALLOW TEMPS (MAINLY SOUTH OF I-70) TO REACH
30F.
TONIGHT-MONDAY NIGHT...AMPLIFIED NW FLOW WILL BE IN PLACE ACROSS THE
PLAINS WITH MAIN STORM TRACK SPLIT AROUND OUR CWA. THERE WILL BE A
SERIES OF CLIPPERS ROTATING THROUGH THE MEAN FLOW...HOWEVER ANY
IMPACT ON SENSIBLE WEATHER OVER OUR CWA SHOULD BE LIMITED TO
INCREASES IN HIGH CLOUD COVER THROUGH THESE PERIODS.
REGARDING TEMPERATURES...THERE WILL BE A SLIGHT MODERATION IN THE
AIR MASS TONIGHT...HOWEVER WITH CANADIAN HIGH PRESSURE STILL BE A
STRONG INFLUENCE ON OUR TEMPS. THE QUESTION IS CLOUD COVER AND TDS AS
WITH CLEARING SKIES AND TDS ON DRIER END OF GUIDANCE COULD SUPPORT
LOWS NEAR ZERO AT SOME LOCATIONS. GUIDANCE SHOWS HIGH CLOUD COVER
INCREASING LATE WHICH LOWERS CONFIDENCE IN IDEAL RADIATIONAL
CONDITIONS. WEAK LEE TROUGH DEVELOPS IN EASTERN COLORADO/WYOMING
WITH DOWNSLOPE FLOW SUPPORTING CONTINUED MODERATION OF THE AIR MASS
THROUGH MONDAY. UPSTREAM SNOW FIELD AND PERIODS OF CLOUD COVER (AND
WINDS DURING THE NIGHT PERIODS) ALL LOWER CONFIDENCE IN TEMPS
THROUGH THE PERIODS. I STUCK WITH SIMILAR TRENDS AS PREVIOUS
FORECAST WITH HIGHS RETURNING TO SEASONAL VALUES AROUND 42 BY
MONDAY...AND OVERNIGHT LOWS IN THE SINGLE DIGITS (WEST) TO THE
TEENS(EAST). A QUICK MOVING SHORTWAVE TROUGH AND PASSING COLD FRONT
COMPLICATES LOWS MONDAY NIGHT...THOUGH WITH CAA IN PLACE EVEN CLOUD
COVER MAY NOT KEEP LOWS FROM DROPPING INTO THE TEENS.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 117 AM MST SAT JAN 9 2016
MODELS CONTINUE TO NOT DO VERY WELL IN THIS TIME PERIOD. A LOT OF
SPREAD REMAINS NOT ONLY WITH THE DETERMINISTIC OUTPUT BUT ALSO THE
ENSEMBLES. MODELS DISAGREE ON HOW AMPLIFIED OR NOT THE FLOW IS WITH
THE OUTPUT OUT OF PHASE BY THE END OF THE PERIOD. ESSENTIALLY THE
FLOW REMAINS WEST TO NORTHWEST AND SOMETIMES EVEN MORE NORTH.
SO MOST OF THE WAVES GOING THROUGH LOOK TO BE OPEN AND FAST MOVING.
SO LITTLE TO NO CHANCE TO GET PRECIPITATION IN THIS SCENARIO. ONE OF
THOSE SHORTWAVES MOVES THROUGH IN THE THURSDAY TO FRIDAY TIME FRAME
AND BRINGS IN A MUCH COLDER AIR MASS. THE COMBINATION OF THE
SHORTWAVE AND COLD AIR ADVECTION SHOULD BE ABLE TO PRODUCE A SMALL
CHANCE OF LIGHT SNOW WHICH IS WHAT THE CRH_INIT GAVE ME FOR FRIDAY
WHICH IS REASONABLE.
WHAT LOOKS TO BE THE MOST UNCERTAIN IS THE TEMPERATURE FORECAST. IN
THIS FLOW COULD POSSIBLY GET A COLD SURGE/BACK DOOR COLD FRONT
MOVING INTO THE AREA. THE INIT GAVE ME WARMER TEMPERATURES IN THE
MIDDLE TO UPPER 40S ON WEDNESDAY AND THURSDAY...WHICH I WILL LEAVE
ALONE FOR NOW DUE TO MODEL DISAGREEMENT...BUT THERE IS DEFINITE
POTENTIAL FOR COLDER TEMPERATURES THOSE DAYS...DEPENDING OF COURSE
ON WHICH MODELS MID/UPPER SOLUTION WORKS OUT.
FRIDAY DEFINITELY LOOKS COLDER AND EVEN INTO THE REMAINDER OF NEXT
WEEKEND. THE PATTERN THE MODEL OUTPUT IS SHOWING...EVEN THOUGH
SHOWING DIFFERENCES...IS CONDUCIVE TO MUCH COLDER TEMPERATURES.
OVERALL NO CHANGES WILL BE MADE TO THE CRH_INIT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1028 AM MST SAT JAN 9 2016
FOR KGLD...WILL SEE A MVFR/VFR MIX IN CEILINGS THRU 20Z THEN VFR
CONDITIONS. BY 07Z SUNDAY...MVFR AGAIN THRU 12Z AS FOG TO 3SM AND
CEILINGS DROP TO OVC010. BY 12Z SUNDAY VFR PREVAILS. WINDS NORTH
AROUND 10KTS THRU 00Z SUNDAY...THEN LGT/VAR THRU 12Z BECOMING SW
AROUND 10KTS.
FOR KMCK...WILL SEE VFR CONDITIONS WITH CEILINGS RANGING
BKN035-150. BY 06Z SUNDAY...MVFR CONDITIONS IN 3SM FOR FOG AND
CEILINGS OVC010. BY 13Z VFR SKY CONDITIONS. WINDS NNE AROUND 10KTS
BECM LGT/VAR BY 00Z SUNDAY. BY 13Z SUNDAY...SW AROUND 10KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...JN
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
320 PM EST SAT JAN 9 2016
.DISCUSSION...
PER RECENT WATER VAPOR IMAGERY...THE MAIN UPPER WAVE IS SHOWN
LIFTING INTO ARKANSAS WHILE A SHORTER WAVELENGTH IMPULSE IS NOW
LIFTING INTO CENTRAL ILLINOIS. MEANWHILE...THERE IS ONGOING
AMPLIFICATION IN THE BASE OF THE CENTRAL CANADIAN POLAR LOW INTO THE
UPPER MIDWEST. THIS HAS BEEN DRIVING AN ARCTIC BOUNDARY SOUTHWARD
ACROSS THE MID MS VALLEY. SFC LOW PRESSURE NOW LOCATED ALONG THE
AR/TN BORDER REGION WILL LIFT NORTHEAST INTO OHIO TONIGHT AS THE MID
LEVEL WAVE ROTATES INTO THE UPPER OHIO VALLEY. THIS WILL SLOW THE
EASTWARD PROGRESS OF THE ARCTIC FRONT ACROSS LOWER MI TONIGHT. DEEP
LAYER MOISTURE ADVECTION AND LARGER SCALE ASCENT ASSOCIATED WITH
THESE UPSTREAM SHORT WAVE FEATURES HAVE BEEN RESULTING IN A
NORTHWARD EXPANSION OF RAIN ACROSS INDIANA AND NE ILLINOIS THIS
AFTERNOON. ACROSS CENTRAL EAST CENTRAL IL AND DEEPER INTO THE COLD
AIR...THE PRECIP HAS BEEN IN THE FORM OF SNOW.
RECENT HI RES SOLUTIONS WITH SUPPORT OF UPSTREAM RADAR/SATELLITE
SUGGEST THE PRECIP WILL FIRST ARRIVE INTO SRN MI ALONG THE MID LEVEL
FRONT WHICH NOW EXTENDS FROM SRN MO INTO CNTL LOWER MI. THIS WILL
CAUSE RAIN TO OVERSPREAD THE WESTERN SECTIONS OF THE FCST AREA AND
SAGINAW VALLEY THIS EVENING. THE APPROACH OF THE UPPER WAVE TONIGHT
WILL CAUSE A TIGHTENING OF THE THERMAL GRADIENT ALONG THE FRONTAL
SLOPE...LEADING TO AN INTENSIFICATION IN THE MID LEVEL FRONTOGENESIS.
THIS ALONG WITH SOME DYNAMIC COOLING WILL LEAD TO A SHARP TRANSITION
ZONE BETWEEN RAIN AND HEAVY WET SNOW. THE RECENT HRRR WITH SUPPORT OF
UPSTREAM OBS CONTINUES TO SUGGEST THIS TRANSITION ZONE WILL BE OVER
MIDLAND/BAY COUNTIES LATE THIS EVENING. THE RAIN/SNOW LINE WILL THEN
SLOWLY PUSH SOUTHEAST ACROSS THE SAGINAW VALLEY OVERNIGHT. THE REST
OF THE FORECAST AREA WILL SEE LIGHT RAIN OR DRIZZLE DURING THIS TIME
PERIOD. THE 12Z MODEL SOLUTIONS ACTUALLY SUGGESTS THE BETTER MID
LEVEL DEFORMATION TRANSITIONING ACROSS THE REMAINDER OF THE FORECAST
AREA RATHER QUICKLY LATE TONIGHT INTO SUN MORNING AS THE UPPER WAVE
LIFTS ACROSS THE UPPER OHIO VALLEY. THE SURFACE LOW WILL IN TURN
DEEPEN AS IT LIFTS FROM NORTHERN OHIO INTO SRN ONTARIO SUN MORNING.
THIS WILL PROPEL THE ARCTIC FRONT ACROSS THE REST OF THE FORECAST
AREA...TRANSITIONING RAIN OVER TO SNOW. THE HEADLINES WILL REMAIN
UNCHANGED. THE POTENTIAL LONG DURATION /03Z TO 09Z/ OF MODERATE TO
HEAVY SNOW STILL SUGGESTS A GOOD CHANCE OF GETTING SNOW AMOUNTS OVER
6 INCHES ACROSS MIDLAND/NRN BAY. THE LATER CHANGE OVER ACROSS THE
ADVISORY AREA /SAGINAW/SHIAWASSEE/TUSCOLA/HURON SUGGESTS 1 TO 4 INCH
TYPE ACCUMS. THE REST OF THE FORECAST AREA WILL CHANGE OVER TO SNOW
AROUND THE TIME THAT THE LARGE SCALE FORCING IS WEAKENING...SO
AMOUNTS WILL BE MUCH LESS.
THE ARCTIC FRONT /FORECAST TO PUSH FROM THE SAGINAW VALLEY AND THUMB
AT 09Z ACROSS METRO DETROIT AND PORT HURON BY 12 TO 13Z/ WILL BE
MARKED AN INCREASE IN WIND GUSTS AND RAPID DROP IN TEMPS /INTO THE
MID 20S/. THIS COULD CAUSE SOME RAPID FREEZING OF WET/SNOW COVERED
ROADWAYS /ESPECIALLY IN THE ADVISORY AND WARNING COUNTIES/. THE
NEGATIVE TILT OF THE MID LEVEL SHORT WAVE LIFTING ACROSS THE UPPER
OHIO VALLEY SUN AND VERY STRONG BAROCLINICITY WILL LEAD TO A RAPIDLY
DEEPENING SURFACE LOW TRACKING ACROSS ONTARIO SUNDAY /FCST TO DROP
TO 982MB BY SUN EVENING/. THIS WILL INCREASE THE NORTHWEST GRADIENT
ACROSS SE MI. AS THE DEPTH OF THE COLD AIR INCREASES DURING SUN
AFTERNOON...WINDS WILL INCREASE /GUSTING UP TO 35 AND 40 MPH AT
TIMES/. TEMPS WILL ALSO CONTINUE TO DROP UNDER THE STEADY
INFILTRATION OF ARCTIC AIR...WITH WIND CHILLS DROPPING TOWARD ZERO
BY LATE SUN AFTERNOON.
MAIN FOCUS FOR THE REST OF THE FORECAST IS ON THE CLIPPER SYSTEM
THAT IS EXPECTED TO BRING ACCUMULATING SNOW TO THE AREA MONDAY NIGHT
AND TUESDAY. THE UPPER WAVE ASSOCIATED WITH THIS DISTURBANCE IS
EXPECTED TO RACE SOUTH-SOUTHEASTWARD ALONG THE WESTERN PERIPHERY OF
THE UPPER LOW OVER WESTERN HUDSON BAY...WITH THE SHEARED-OUT VORT
MAX QUICKLY BECOMING MORE CIRCULAR DIRECTLY OVER THE WESTERN GREAT
LAKES. THIS PROCESS IS EXPECTED TO LEAD TO RAPID CYCLOGENESIS OVER
MID-MICHIGAN/LAKE HURON MONDAY NIGHT INTO TUESDAY. NWP CONTINUES TO
BE IN GOOD AGREEMENT WITH THE EVOLUTION OF THESE FEATURES.
GFS/ECMWF/NAM ALL STRENGTHEN THE SURFACE LOW 8-12 MB IN 12 HR FROM
06-18Z TUESDAY.
THE FIRST PHASE OF THIS EVENT APPEARS TO BE A RELATIVELY UNIFORM
DISTRIBUTION OF LIGHT SNOW MONDAY NIGHT...FORCED BY ISENTROPIC LIFT
INITIALLY AND THEN WITH A CONTRIBUTION FROM DCVA AS THE UPPER WAVE
APPROACHES. THE PASSAGE OF A STRONG COLD FRONT AROUND 12Z TUESDAY
WILL LIKELY RESULT IN THE TRANSITION TO MORE OF A LAKE EFFECT EVENT.
A QUICK LOOK AT SOME OF THE LAKE EFFECT PARAMETERS SUGGESTS THE
POTENTIAL FOR SNOW SQUALLS EXTENDING INTO SOUTHEAST MICHIGAN. H850
TEMPS DROP TO NEAR -17C WITH 0-1KM THETA-E LAPSE RATES DOWN TO -6
K/KM OVER LAKE MICHIGAN. MEANWHILE TEMPS WILL BE DROPPING INTO THE
TEENS WITH SUSTAINED WINDS APPROACHING 20 MPH...WHICH MAY RESULT IN
WIND CHILLS INTO THE SINGLE DIGITS. ALL TOLD...EARLY INDICATIONS ARE
FOR 2 TO 4 INCHES WITH LOCALES THAT SEE MORE IN THE WAY OF LAKE
EFFECT TUESDAY TOWARD THE HIGHER END OF THAT RANGE.
TEMPERATURES WILL REMAIN ON THE CHILLY SIDE WITH PERHAPS A
MODERATING TREND TOWARD THE END OF THE WEEK AS THE HUDSON BAY UPPER
LOW DRIFTS A BIT NORTH AND EAST INTO QUEBEC. DISTURBANCES ROTATING
AROUND THE UPPER LOW WILL PROVIDE A FEW MORE CHANCES FOR LIGHT SNOW
FROM THE MIDDLE TO THE END OF NEXT WEEK.
&&
.MARINE...
MILD AIR AND LIGHT WINDS AROUND EARLY THIS EVENING WILL ABRUPTLY
CHANGE LATE TONIGHT AS A RAPIDLY DEEPENING LOW PRESSURE SYSTEM
TRACKS NORTHEAST THROUGH THE EASTERN GREAT LAKES. STRONG NORTHWEST
GALES WILL DEVELOP IN THE LOWS WAKE TOMORROW MORNING...AS ARCTIC AIR
SURGES INTO THE AREA. WITH THE GALES AND PLUMMETING TEMPERATURES...A
HEAVY FREEZING SPRAY WARNING IS IN EFFECT FOR SUNDAY AFTERNOON.
WINDS WILL DIMINISH AND BACK TO WESTERLY BY MONDAY MORNING BUT WILL
REMAIN ELEVATED IN THE 20 TO 30 KNOT RANGE. A SECOND SURGE OF ARCTIC
AIR IS EXPECTED ON TUESDAY...WHICH LOOKS TO SUPPORT ANOTHER PERIOD
OF STRONG NORTHWEST GALES AND HEAVY FREEZING SPRAY OVER THE OPEN
WATERS OF LAKE HURON. A GALE WATCH WAS NOT ISSUED DUE TO CURRENT
HEADLINE IN EFFECT.
&&
.HYDROLOGY...
DEEPENING LOW PRESSURE WILL TRACK THROUGH THE EASTERN GREAT LAKES
TONIGHT...SPREADING A GOOD SLUG OF MOISTURE INTO THE REGION.
PRECIPITATION WILL START OFF AS RAIN THIS EVENING BEFORE COLD AIR
SURGES IN FROM THE NORTH...QUICKLY CHANGING IT OVER TO SNOW BY
SUNDAY MORNING. HIGHEST SNOWFALL AMOUNTS WILL OCCUR ACROSS THE
SAGINAW VALLEY AREA...TAPERING OFF HEADING SOUTHWARD. TOTAL
PRECIPITATION AMOUNTS ARE EXPECTED TO RANGE FROM THREE QUARTERS OF
AN INCH ACROSS TRI-CITIES REGION TAPERING OFF SOUTHEAST TO A QUARTER
OF AN INCH IN AND AROUND DETROIT. TEMPERATURES PLUMMETING INTO THE
TEENS SUNDAY EVENING WILL FREEZE ANY LEFTOVER STANDING WATER.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING FROM 9 PM THIS EVENING TO NOON EST SUNDAY FOR
MIZ047-048.
WINTER WEATHER ADVISORY FROM 3 AM TO 4 PM EST SUNDAY FOR MIZ049-054.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SUNDAY
FOR MIZ053-060.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM SUNDAY TO 4 AM EST MONDAY
FOR LHZ462>464.
GALE WARNING FROM 4 AM SUNDAY TO 6 AM EST MONDAY FOR LHZ361>363-
462>464.
GALE WARNING FROM 4 AM TO 11 PM EST SUNDAY FOR LHZ421-422-441>443.
HEAVY FREEZING SPRAY WARNING FROM 1 PM SUNDAY TO 4 AM EST MONDAY
FOR LHZ361>363.
LAKE ST CLAIR...GALE WARNING FROM 7 AM TO 11 PM EST SUNDAY FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...GALE WARNING FROM 7 AM TO 11 PM EST SUNDAY FOR LEZ444.
&&
$$
DISCUSSION...SC/DT
MARINE.......SF
HYDROLOGY....SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
316 PM EST SAT JAN 9 2016
.DISCUSSION...
PER RECENT WATER VAPOR IMAGERY...THE MAIN UPPER WAVE IS SHOWN
LIFTING INTO ARKANSAS WHILE A SHORTER WAVELENGTH IMPULSE IS NOW
LIFTING INTO CENTRAL ILLINOIS. MEANWHILE...THERE IS ONGOING
AMPLIFICATION IN THE BASE OF THE CENTRAL CANADIAN POLAR LOW INTO THE
UPPER MIDWEST. THIS HAS BEEN DRIVING AN ARCTIC BOUNDARY SOUTHWARD
ACROSS THE MID MS VALLEY. SFC LOW PRESSURE NOW LOCATED ALONG THE
AR/TN BORDER REGION WILL LIFT NORTHEAST INTO OHIO TONIGHT AS THE MID
LEVEL WAVE ROTATES INTO THE UPPER OHIO VALLEY. THIS WILL SLOW THE
EASTWARD PROGRESS OF THE ARCTIC FRONT ACROSS LOWER MI TONIGHT. DEEP
LAYER MOISTURE ADVECTION AND LARGER SCALE ASCENT ASSOCIATED WITH
THESE UPSTREAM SHORT WAVE FEATURES HAVE BEEN RESULTING IN A
NORTHWARD EXPANSION OF RAIN ACROSS INDIANA AND NE ILLINOIS THIS
AFTERNOON. ACROSS CENTRAL EAST CENTRAL IL AND DEEPER INTO THE COLD
AIR...THE PRECIP HAS BEEN IN THE FORM OF SNOW.
RECENT HI RES SOLUTIONS WITH SUPPORT OF UPSTREAM RADAR/SATELLITE
SUGGEST THE PRECIP WILL FIRST ARRIVE INTO SRN MI ALONG THE MID LEVEL
FRONT WHICH NOW EXTENDS FROM SRN MO INTO CNTL LOWER MI. THIS WILL
CAUSE RAIN TO OVERSPREAD THE WESTERN SECTIONS OF THE FCST AREA AND
SAGINAW VALLEY THIS EVENING. THE APPROACH OF THE UPPER WAVE TONIGHT
WILL CAUSE A TIGHTENING OF THE THERMAL GRADIENT ALONG THE FRONTAL
SLOPE...LEADING TO AN INTENSIFICATION IN THE MID LEVEL FRONTOGENESIS.
THIS ALONG WITH SOME DYNAMIC COOLING WILL LEAD TO A SHARP TRANSITION
ZONE BETWEEN RAIN AND HEAVY WET SNOW. THE RECENT HRRR WITH SUPPORT OF
UPSTREAM OBS CONTINUES TO SUGGEST THIS TRANSITION ZONE WILL BE OVER
MIDLAND/BAY COUNTIES LATE THIS EVENING. THE RAIN/SNOW LINE WILL THEN
SLOWLY PUSH SOUTHEAST ACROSS THE SAGINAW VALLEY OVERNIGHT. THE REST
OF THE FORECAST AREA WILL SEE LIGHT RAIN OR DRIZZLE DURING THIS TIME
PERIOD. THE 12Z MODEL SOLUTIONS ACTUALLY SUGGESTS THE BETTER MID
LEVEL DEFORMATION TRANSITIONING ACROSS THE REMAINDER OF THE FORECAST
AREA RATHER QUICKLY LATE TONIGHT INTO SUN MORNING AS THE UPPER WAVE
LIFTS ACROSS THE UPPER OHIO VALLEY. THE SURFACE LOW WILL IN TURN
DEEPEN AS IT LIFTS FROM NORTHERN OHIO INTO SRN ONTARIO SUN MORNING.
THIS WILL PROPEL THE ARCTIC FRONT ACROSS THE REST OF THE FORECAST
AREA...TRANSITIONING RAIN OVER TO SNOW. THE HEADLINES WILL REMAIN
UNCHANGED. THE POTENTIAL LONG DURATION /03Z TO 09Z/ OF MODERATE TO
HEAVY SNOW STILL SUGGESTS A GOOD CHANCE OF GETTING SNOW AMOUNTS OVER
6 INCHES ACROSS MIDLAND/NRN BAY. THE LATER CHANGE OVER ACROSS THE
ADVISORY AREA /SAGINAW/SHIAWASSEE/TUSCOLA/HURON SUGGESTS 1 TO 4 INCH
TYPE ACCUMS. THE REST OF THE FORECAST AREA WILL CHANGE OVER TO SNOW
AROUND THE TIME THAT THE LARGE SCALE FORCING IS WEAKENING...SO
AMOUNTS WILL BE MUCH LESS.
THE ARCTIC FRONT /FORECAST TO PUSH FROM THE SAGINAW VALLEY AND THUMB
AT 09Z ACROSS METRO DETROIT AND PORT HURON BY 12 TO 13Z/ WILL BE
MARKED AN INCREASE IN WIND GUSTS AND RAPID DROP IN TEMPS /INTO THE
MID 20S/. THIS COULD CAUSE SOME RAPID FREEZING OF WET/SNOW COVERED
ROADWAYS /ESPECIALLY IN THE ADVISORY AND WARNING COUNTIES/. THE
NEGATIVE TILT OF THE MID LEVEL SHORT WAVE LIFTING ACROSS THE UPPER
OHIO VALLEY SUNDAY AND VERY STRONG BAROCLINICITY WILL LEAD TO A
RAPIDLY DEEPENING SURFACE LOW TRACKING ACROSS ONTARIO /FCST TO
DROP TO 982MB BY SUN EVENING/. THIS WILL INCREASE THE NORTHWEST
GRADIENT ACROSS SE MI. AS THE DEPTH OF THE COLD AIR INCREASES
DURING SUN AFTERNOON...WINDS WILL INCREASE /GUSTING UP TO 35 AND
40 MPH AT TIMES/. TEMPS WILL ALSO CONTINUE TO DROP UNDER THE
STEADY INFILTRATION OF ARCTIC AIR...WITH WIND CHILLS DROPPING
TOWARD ZERO BY LATE SUN AFTERNOON.
MAIN FOCUS FOR THE REST OF THE FORECAST IS ON THE CLIPPER SYSTEM
THAT IS EXPECTED TO BRING ACCUMULATING SNOW TO THE AREA MONDAY NIGHT
AND TUESDAY. THE UPPER WAVE ASSOCIATED WITH THIS DISTURBANCE IS
EXPECTED TO RACE SOUTH-SOUTHEASTWARD ALONG THE WESTERN PERIPHERY OF
THE UPPER LOW OVER WESTERN HUDSON BAY...WITH THE SHEARED-OUT VORT
MAX QUICKLY BECOMING MORE CIRCULAR DIRECTLY OVER THE WESTERN GREAT
LAKES. THIS PROCESS IS EXPECTED TO LEAD TO RAPID CYCLOGENESIS OVER
MID-MICHIGAN/LAKE HURON MONDAY NIGHT INTO TUESDAY. NWP CONTINUES TO
BE IN GOOD AGREEMENT WITH THE EVOLUTION OF THESE FEATURES.
GFS/ECMWF/NAM ALL STRENGTHEN THE SURFACE LOW 8-12 MB IN 12 HR FROM
06-18Z TUESDAY.
THE FIRST PHASE OF THIS EVENT APPEARS TO BE A RELATIVELY UNIFORM
DISTRIBUTION OF LIGHT SNOW MONDAY NIGHT...FORCED BY ISENTROPIC LIFT
INITIALLY AND THEN WITH A CONTRIBUTION FROM DCVA AS THE UPPER WAVE
APPROACHES. THE PASSAGE OF A STRONG COLD FRONT AROUND 12Z TUESDAY
WILL LIKELY RESULT IN THE TRANSITION TO MORE OF A LAKE EFFECT EVENT.
A QUICK LOOK AT SOME OF THE LAKE EFFECT PARAMETERS SUGGESTS THE
POTENTIAL FOR SNOW SQUALLS EXTENDING INTO SOUTHEAST MICHIGAN. H850
TEMPS DROP TO NEAR -17C WITH 0-1KM THETA-E LAPSE RATES DOWN TO -6
K/KM OVER LAKE MICHIGAN. MEANWHILE TEMPS WILL BE DROPPING INTO THE
TEENS WITH SUSTAINED WINDS APPROACHING 20 MPH...WHICH MAY RESULT IN
WIND CHILLS INTO THE SINGLE DIGITS. ALL TOLD...EARLY INDICATIONS ARE
FOR 2 TO 4 INCHES WITH LOCALES THAT SEE MORE IN THE WAY OF LAKE
EFFECT TUESDAY TOWARD THE HIGHER END OF THAT RANGE.
TEMPERATURES WILL REMAIN ON THE CHILLY SIDE WITH PERHAPS A
MODERATING TREND TOWARD THE END OF THE WEEK AS THE HUDSON BAY UPPER
LOW DRIFTS A BIT NORTH AND EAST INTO QUEBEC. DISTURBANCES ROTATING
AROUND THE UPPER LOW WILL PROVIDE A FEW MORE CHANCES FOR LIGHT SNOW
FROM THE MIDDLE TO THE END OF NEXT WEEK.
&&
.MARINE...
MILD AIR AND LIGHT WINDS AROUND EARLY THIS EVENING WILL ABRUPTLY
CHANGE LATE TONIGHT AS A RAPIDLY DEEPENING LOW PRESSURE SYSTEM
TRACKS NORTHEAST THROUGH THE EASTERN GREAT LAKES. STRONG NORTHWEST
GALES WILL DEVELOP IN THE LOWS WAKE TOMORROW MORNING...AS ARCTIC AIR
SURGES INTO THE AREA. WITH THE GALES AND PLUMMETING TEMPERATURES...A
HEAVY FREEZING SPRAY WARNING IS IN EFFECT FOR SUNDAY AFTERNOON.
WINDS WILL DIMINISH AND BACK TO WESTERLY BY MONDAY MORNING BUT WILL
REMAIN ELEVATED IN THE 20 TO 30 KNOT RANGE. A SECOND SURGE OF ARCTIC
AIR IS EXPECTED ON TUESDAY...WHICH LOOKS TO SUPPORT ANOTHER PERIOD
OF STRONG NORTHWEST GALES AND HEAVY FREEZING SPRAY OVER THE OPEN
WATERS OF LAKE HURON. A GALE WATCH WAS NOT ISSUED DUE TO CURRENT
HEADLINE IN EFFECT.
&&
.AVIATION...ISSUED 1200 PM EST SAT JAN 9 2016
HUNG UP FRONTAL BOUNDARY OVER SOUTHEAST MICHIGAN THIS AFTERNOON AND
EVENING WILL LEAD TO WEAK SURFACE WINDS AND PERSISTENT LOW LEVEL
MOISTURE TO SUSTAIN IFR/LIFR CONDITIONS...EXCEPT ACROSS SOUTHERN
TAF SITES THIS EARLY AFTERNOON WHERE PERIOD OF MVFR CEILINGS LOOK
TO PREVAIL. SURFACE DEW PTS OF 40+ F ACROSS MUCH OF SOUTHEAST
MICHIGAN INDICATIVE OF THE MILD AIR...AND LOOKS LIKE DEVELOPING
PRECIPITATION LATER TODAY WILL FALL AS RAIN OVER TAF SITES INTO
THIS EVENING...WITH ABRUPT AND SHARP CHANGEOVER TO SNOW OCCURRING
FROM NORTHWEST TO SOUTHEAST OVERNIGHT INTO EARLY SUNDAY MORNING.
AS THE CHANGEOVER TO SNOW OCCURS...NORTH-NORTHWEST WINDS WILL
RAMP UP QUICKLY...WITH GUSTS APPROACHING 35 KNOTS DURING THE DAY
ON SUNDAY AS RUSH OF ARCTIC AIR TAKES HOLD. AT THIS TIME...LOOKS
LIKE TOTAL SNOWFALL AMOUNTS WILL BE HIGHEST OVER MBS...BETWEEN 3
TO 5 INCHES...WITH FNT/PTK IN THE 1 TO 3 INCH RANGE...AND
DTW/YIP/DET CLOSER TO 1 INCH.
FOR DTW...MVFR CEILINGS/PARTIAL BREAKS IN THE CLOUD COVER AROUND
NOON HOUR SHOULD FILL BACK IN AND CEILINGS LOWERING BACK INTO IFR
BY EARLY EVENING. THIS EVENING AND TONIGHT NOT MUCH RAIN IS
EXPECTED...AS BULK OF PRECIPITATION FALLS TO THE WEST. CARRYING
IFR THROUGH EVENING AND BULK OF THE NIGHT...BUT LIFR REMAINS
POSSIBLE. HEAVIER PRECIPITATION SHOULD SPREAD IN 9-12Z...CHANGING
TO SNOW AROUND 12Z AS STRONG NORTHWEST WINDS PICK UP. SHORT WINDOW
FOR GOOD SNOWFALL RATES (VISIBILITY BELOW 1SM) SUGGESTS
ACCUMULATIONS AROUND 1 INCH...BUT LIGHT SNOW SHOWERS/FLURRIES
COULD PERSIST FOR MUCH OF THE DAY. HIGH CONFIDENCE IN WINDS
GUSTING BETWEEN 30 AND 35 KNOTS FROM 310-330 DIRECTION SUNDAY
MORNING/EARLY SUNDAY AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILINGS AOB 5000 FEET THROUGH THE TAF PERIOD.
* LOW FOR CIGS/VSBYS FALLING BELOW 200FT AND/OR 1/2SM THIS
EVENING THROUGH MID SUNDAY MORNING.
* HIGH FOR PRECIPITATION TYPE AS RAIN THROUGH 11Z SUNDAY
MORNING...BECOMING ALL SNOW BY 13Z.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING FROM 9 PM THIS EVENING TO NOON EST SUNDAY FOR
MIZ047-048.
WINTER WEATHER ADVISORY FROM 3 AM TO 4 PM EST SUNDAY FOR MIZ049-054.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SUNDAY
FOR MIZ053-060.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM SUNDAY TO 4 AM EST MONDAY
FOR LHZ462>464.
GALE WARNING FROM 4 AM SUNDAY TO 6 AM EST MONDAY FOR LHZ361>363-
462>464.
GALE WARNING FROM 4 AM TO 11 PM EST SUNDAY FOR LHZ421-422-441>443.
HEAVY FREEZING SPRAY WARNING FROM 1 PM SUNDAY TO 4 AM EST MONDAY
FOR LHZ361>363.
LAKE ST CLAIR...GALE WARNING FROM 7 AM TO 11 PM EST SUNDAY FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...GALE WARNING FROM 7 AM TO 11 PM EST SUNDAY FOR LEZ444.
&&
$$
DISCUSSION...SC/DT
MARINE.......SF
AVIATION.....SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
249 PM EST SAT JAN 9 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 407 AM EST SAT JAN 9 2016
MUCH COLDER AIR WILL BEGIN SURGING INTO THE AREA TODAY AND LEAD TO
BELOW NORMAL TEMPERATURES (WITH LAKE EFFECT SNOW) THROUGH AT LEAST
THE MIDDLE OF THE UPCOMING WORK WEEK. THE COLD AIR IS NOW STARTING
TO MOVE INTO THE WESTERN U.P. (RAP ANALYSIS SHOWING 850MB TEMPS
AROUND -7C AND -12C UPSTREAM IN THE MINNESOTA ARROWHEAD) AND THAT
WILL CONTINUE ACROSS THE AREA TODAY. BEFORE THAT OCCURS...A SURFACE
LOW IS CURRENTLY LOCATED OVER THE EASTERN U.P. AND IS CONTINUING TO
PRODUCE PRECIPITATION AS A SHORTWAVE LIFTS NORTHEAST THROUGH THE
AREA. WHILE MUCH OF THE PRECIPITATION OVER THE EASTERN U.P. FELL AS
RAIN THROUGH THE EVENING...HAVE BEEN SEEING A TRANSITION TO SNOW NOW
AS THE COLDER AIR IS STARTING TO WORK INTO THAT AREA (3AM METARS
SHOW KISQ IS THE ONLY SITE HANGING ON TO RAIN). EVENING SHIFT
FOLLOWED THE WETBULB0 HEIGHTS FROM THE RAP FOR THE RAIN/SNOW
TRANSITION AND THAT STILL SEEMS REASONABLE WITH THE LATEST RUNS.
HAVE FOLLOWED THAT WHICH TRANSITIONS THE LINGERING PRECIPITATION
OVER THE EAST TO SNOW BY THROUGH 5-6AM. OVER THE WEST HALF...HAVE
SEEN A LITTLE BIT OF A LULL (LIGHT SNOW FARTHER TO THE SOUTHWEST IN
SOUTHWESTERN WISCONSIN TIED WITH BETTER MOISTURE AND TRAILING COLD
FRONT)...BUT WITH THE COLDER AIR MOVING INTO THE AREA...VISIBILITIES
STARTED TO FALL WITH SNOW AT KIWD/KCMX AROUND 1AM AND HAVE BEEN
BOUNCING THROUGH THE NIGHT (LIKELY MORE TIED WITH THE LIGHT SNOW
SHOWERS MOVING IN FROM WISCONSIN THAN PURE LAKE EFFECT AT THIS
POINT). 3AM TEMPERATURES ARE STILL HOLDING ON TO THE LOWER 30S OVER
THE EASTERN 2/3RDS OF THE U.P. AND IN THE UPPER 20S TO THE WEST OF
THAT.
WITH THE COLDER AIR SURGING IN TODAY...EXPECT A TRANSITION TO PURE
LES THROUGH THE MORNING FOR THE NORTHERLY WIND SNOWBELTS BEFORE
GRADUALLY TRANSITIONING TO THE NORTHWEST WIND AREAS THROUGH THE
AFTERNOON. INVERSION HEIGHTS ARE FORECASTED TO BE AROUND 5KFT WHICH
IS SOMEWHAT LIMITING...BUT THE CLOUD WILL MOVE ENTIRELY WITHIN THE
DGZ THIS AFTERNOON AND WITH WINDS GENERALLY IN THE 15-25KT RANGE
THERE WON/T BE TOO MUCH FRACTURING. THUS...HAVE TRENDED SNOW RATIOS
UP INTO THE UPPER 20S AND WOULDN/T BE SURPRISED IF SOME LOCATIONS
END UP IN THE 30S TO 1 RANGE BASED OFF PAST SITUATIONS HERE AT OUR
OFFICE THAT HAVE YIELDED SNOW RATIOS AT OR EVEN ABOVE THOSE VALUES.
THE LOWER INVERSION HEIGHTS WILL LIKELY LIMIT THE OVERALL STRENGTH
OF THE LAKE EFFECT...BUT WITH RATIOS THAT HIGH STILL EXPECT
OCCASIONAL MODERATE SNOWFALL. HAVE SNOWFALL AMOUNTS OF 1 TO 4 INCHES
TODAY OVER THE FAVORED AREAS OVER THE FAR WESTERN U.P....WITH THE
GREATEST AMOUNTS OVER THE HIGHER TERRAIN OF GOGEBIC/ONTONAGON
COUNTIES. ONE OTHER LIMITING FACTOR FOR TODAY IS THAT THERE WILL BE
ENOUGH BACKING OF THE WINDS FROM NORTH-NORTHWEST TO NORTHWEST TODAY
TO MOVE THE BANDS AROUND ENOUGH TO LIMIT THE RESIDENCE TIME OF THE
STRONGER BANDS IN ANY ONE LOCATION. FARTHER TO THE EAST...EXPECT
SOME LAKE ENHANCEMENT NEAR LAKE SUPERIOR THROUGH THE DAY WITH THE
NORTH AND EVENTUALLY NORTHWEST WINDS...BUT INVERSION STRUGGLE TO
RISE MUCH ABOVE 4KFT WITH LESS FAVORABLE MOISTURE. THUS...DON/T
EXPECT MUCH MORE THAN A LIGHT DUSTING TO AN INCH OF SNOW TODAY THERE
AND EXPECT SCATTERED SNOW SHOWERS AND MAYBE A DUSTING OF SNOW FOR
THE REST OF THE U.P. AS THE COLD FRONT MOVES THROUGH AND THE SNOW
SHOWERS IN WISCONSIN SLIDE EAST-NORTHEAST THROUGH THE AREA. FINALLY
FOR TEMPERATURES...EXPECT STEADILY FALLING TEMPERATURES THROUGH THE
DAY...WITH VALUES AROUND SUNSET RANGING FROM THE MID TEENS OVER THE
WEST AND UPPER 20S OVER THE EAST.
FOR TONIGHT...EXPECT THE LAKE EFFECT TO CONTINUE FOR AREAS NEAR LAKE
SUPERIOR AS THE WINDS VEER BACK TO A MORE NORTHERLY DIRECTION IN
RESPONSE TO A SURFACE RIDGE TRYING TO NOSE INTO THE AREA AND A
SURFACE LOW LIFTING NORTH INTO THE LOWER GREAT LAKES. 850MB TEMPS
CONTINUE TO FALL THROUGH THE NIGHT (DOWN TO -21C OVER THE
WEST)...PUSHING THE CLOUD LAYER OUT OF THE DGZ. THAT WILL TRANSITION
THE SNOW FLAKE SIZE AND RATIOS DOWN THROUGH THE NIGHT. INVERSION
HEIGHTS STILL STAY IN THE 5-6KFT RANGE...SO STILL EXPECT LIGHT TO
OCCASIONALLY MODERATE LAKE EFFECT TO OCCUR AND HAVE ANOTHER 1-4
INCHES OF SNOW FOR THE SAME AREAS OUT WEST. THE EAST WILL SEE A
COMBINATION OF TWO FEATURES FOR TONIGHT. FIRST...THE AREA WILL BE
BRUSHED BY SNOW ASSOCIATED WITH THE SURFACE LOW LIFTING NORTHEAST
THROUGH THE EASTERN GREAT LAKES. THE HEAVIEST SNOW WILL OCCUR JUST
TO THE SOUTHEAST OF THE AREA...BUT COULD SEE A LIGHT DUSTING OVER
SOUTHERN SCHOOLCRAFT AND SOUTHERN LUCE COUNTIES. THEN FOR THE LAKE
EFFECT AREAS CLOSER TO LAKE SUPERIOR...THINK THINGS WILL INTENSIFY
THROUGH THE NIGHT AS THE COLDER AIR FINALLY ARRIVES...RAISING
INVERSION HEIGHTS TO 5-6KFT AND PUTS THE CLOUD WITHIN THE DGZ.
EXPECT SNOWFALL AMOUNTS TO BE SIMILAR TO OUT WEST IN THE FAVORED
TIME COINCIDING WITH THE CLOUD IN THE DGZ WITH 1 TO 3 INCHES OF
SNOW. WHILE WINDS WILL BE PICKING UP OVER THE EAST...THINK THE AREA
WILL NEED SOME TIME TO ACCUMULATE SNOW (AFTER THE RAIN THIS EVENING)
BEFORE THE BLOWING SNOW WILL REALLY PICKUP.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 249 PM EST SAT JAN 9 2016
NAM SHOWS A 500 MB RIDGE ON THE WEST COAST 00Z MON WITH A DEEP
TROUGH ACROSS THE UPPER GREAT LAKES. A SHORTWAVE DIGS DOWN THE
BACKSIDE OF THE TROUGH LATE ON MON AND MOVES THROUGH THE AREA MON
NIGHT. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE AND DEEPER
MOISTURE MOVING INTO THE AREA MON AFTERNOON LASTING INTO TUE
AFTERNOON. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST
OVERALL FOR TEMPERATURES OR POPS. LAKE EFFECT SNOW WILL CONTINUE IN
WEST AND NORTHWEST LAKE EFFECT SNOW BELTS.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE OVER
THE GREAT LAKES REGION INTO NEW ENGLAND 12Z WED WITH 850 MB
TEMPERATURES AROUND -21C OVER LAKE SUPERIOR. THE TROUGHING ALOFT
STAYS THROUGH 12Z THU WITH AN ALBERTA CLIPPER SYSTEM MOVING THROUGH
THE AREA. THE AIRMASS STARTS TO SLOWLY MODIFY ON FRI WITH THE TROUGH
AXIS TO THE EAST OF THE AREA 12Z FRI. THE AIRMASS CONTINUES TO
MODIFY SLOWLY ON SATURDAY. LAKE EFFECT SNOW WILL CONTINUE THROUGH
MOST OF THIS PERIOD ALONG WITH BELOW NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1254 PM EST SAT JAN 9 2016
LOOK FOR CONTINUED DETERIORATED CONDITIONS AT ALL SITES THROUGH THE
PERIOD...AS COLD AIR MOVING INTO THE AREA LEADS TO A PROLONGED
PERIOD OF LAKE EFFECT SNOW BEHIND A SERIES OF LOW PRESSURE SYSTEMS
TO OUR E AND HIGH PRESSURE SET UP ACROSS THE N AND CENTRAL PLAINS.
CEILINGS HAVE FALLEN TO MVFR TO HIGH END IFR /LOWEST AT IWD WHERE
THE FAVORABLE NW WINDS HAVE TAKEN HOLD. CONTINUED CALM WINDS REPORTED
AT IWD LOOK TO BE A CONTINUED TECHNICAL ISSUE FROM THE SITE. HAVE
EDITED THE LAST LINE OF THE TAF TO AMD LTD TO CLD AND VIS.
TEMPORARILY BLSN COULD BE A POSSIBILITY LATE TONIGHT THROUGH SUNDAY
MAINLY AT CMX AND SAW...WHERE THE PRESSURE GRADIENT REMAINS
STRONGEST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 AM EST SAT JAN 9 2016
A BROAD SURFACE LOW OVER NORTHERN LAKE MICHIGAN WILL CONTINUE
NORTHEAST AND SLOWLY DISSIPATE TODAY WHILE A SECONDARY LOW TAKES
SHAPE IN THE SOUTHERN PLAINS. WINDS HAVE ALREADY SHIFTED TO THE
NORTHWEST OVER THE WESTERN HALF OF THE LAKE AND EXPECT THAT WIND
SHIFT TO SLIDE EAST ACROSS THE REST OF THE LAKE THROUGH THE MORNING
HOURS. AT THIS POINT...ONLY EXPECT WINDS UP TO 30KTS THROUGH THIS
EVENING...BUT AS THE SECONDARY LOW LIFTS NORTHEAST THROUGH THE
SOUTHEASTERN GREAT LAKES LATE TONIGHT AND SUNDAY MORNING...THE
GRADIENT BETWEEN THE LOW AND THE HIGH IN THE CENTRAL/NORTHERN
PLAINS WILL PRODUCE OCCASIONAL NORTHERLY GALES TO 35KTS OVER THE
EASTERN HALF OF LAKE SUPERIOR. WITH ONLY MARGINAL GALES
EXPECTED...WILL KEEP THE GALE WATCH IN PLACE AND ALLOW THE DAY
SHIFT ONE FINAL LOOK TO SEE IF THE MODELS CONTINUE TO TREND WINDS
DOWN. ALSO EXPECT A PERIOD OF FREEZING SPRAY AND MAY NEED A HEAVY
FREEZING SPRAY WARNING IF THE WINDS/WAVES STAY AT THE CURRENTLY
FORECASTED LEVELS. THE WINDS WILL QUICKLY DIMINISH SUNDAY NIGHT AS
THE LOW DEPARTS...BUT ANOTHER LOW WILL QUICKLY DROP SOUTHEAST ACROSS
THE UPPER GREAT LAKES MONDAY NIGHT AND BRING ANOTHER POTENTIAL FOR
NORTHERLY GALES TUESDAY INTO TUESDAY EVENING. BEHIND THE LOW...A
HIGH PRESSURE RIDGE WILL MOVE INTO THE AREA FOR WEDNESDAY AND
DIMINISH WINDS BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 AM TO 10 PM EST SUNDAY FOR LSZ249>251-266-
267.
LAKE MICHIGAN...
GALE WARNING FROM 7 AM TO 7 PM EST SUNDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...07
AVIATION...KF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1255 PM EST SAT JAN 9 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 407 AM EST SAT JAN 9 2016
MUCH COLDER AIR WILL BEGIN SURGING INTO THE AREA TODAY AND LEAD TO
BELOW NORMAL TEMPERATURES (WITH LAKE EFFECT SNOW) THROUGH AT LEAST
THE MIDDLE OF THE UPCOMING WORK WEEK. THE COLD AIR IS NOW STARTING
TO MOVE INTO THE WESTERN U.P. (RAP ANALYSIS SHOWING 850MB TEMPS
AROUND -7C AND -12C UPSTREAM IN THE MINNESOTA ARROWHEAD) AND THAT
WILL CONTINUE ACROSS THE AREA TODAY. BEFORE THAT OCCURS...A SURFACE
LOW IS CURRENTLY LOCATED OVER THE EASTERN U.P. AND IS CONTINUING TO
PRODUCE PRECIPITATION AS A SHORTWAVE LIFTS NORTHEAST THROUGH THE
AREA. WHILE MUCH OF THE PRECIPITATION OVER THE EASTERN U.P. FELL AS
RAIN THROUGH THE EVENING...HAVE BEEN SEEING A TRANSITION TO SNOW NOW
AS THE COLDER AIR IS STARTING TO WORK INTO THAT AREA (3AM METARS
SHOW KISQ IS THE ONLY SITE HANGING ON TO RAIN). EVENING SHIFT
FOLLOWED THE WETBULB0 HEIGHTS FROM THE RAP FOR THE RAIN/SNOW
TRANSITION AND THAT STILL SEEMS REASONABLE WITH THE LATEST RUNS.
HAVE FOLLOWED THAT WHICH TRANSITIONS THE LINGERING PRECIPITATION
OVER THE EAST TO SNOW BY THROUGH 5-6AM. OVER THE WEST HALF...HAVE
SEEN A LITTLE BIT OF A LULL (LIGHT SNOW FARTHER TO THE SOUTHWEST IN
SOUTHWESTERN WISCONSIN TIED WITH BETTER MOISTURE AND TRAILING COLD
FRONT)...BUT WITH THE COLDER AIR MOVING INTO THE AREA...VISIBILITIES
STARTED TO FALL WITH SNOW AT KIWD/KCMX AROUND 1AM AND HAVE BEEN
BOUNCING THROUGH THE NIGHT (LIKELY MORE TIED WITH THE LIGHT SNOW
SHOWERS MOVING IN FROM WISCONSIN THAN PURE LAKE EFFECT AT THIS
POINT). 3AM TEMPERATURES ARE STILL HOLDING ON TO THE LOWER 30S OVER
THE EASTERN 2/3RDS OF THE U.P. AND IN THE UPPER 20S TO THE WEST OF
THAT.
WITH THE COLDER AIR SURGING IN TODAY...EXPECT A TRANSITION TO PURE
LES THROUGH THE MORNING FOR THE NORTHERLY WIND SNOWBELTS BEFORE
GRADUALLY TRANSITIONING TO THE NORTHWEST WIND AREAS THROUGH THE
AFTERNOON. INVERSION HEIGHTS ARE FORECASTED TO BE AROUND 5KFT WHICH
IS SOMEWHAT LIMITING...BUT THE CLOUD WILL MOVE ENTIRELY WITHIN THE
DGZ THIS AFTERNOON AND WITH WINDS GENERALLY IN THE 15-25KT RANGE
THERE WON/T BE TOO MUCH FRACTURING. THUS...HAVE TRENDED SNOW RATIOS
UP INTO THE UPPER 20S AND WOULDN/T BE SURPRISED IF SOME LOCATIONS
END UP IN THE 30S TO 1 RANGE BASED OFF PAST SITUATIONS HERE AT OUR
OFFICE THAT HAVE YIELDED SNOW RATIOS AT OR EVEN ABOVE THOSE VALUES.
THE LOWER INVERSION HEIGHTS WILL LIKELY LIMIT THE OVERALL STRENGTH
OF THE LAKE EFFECT...BUT WITH RATIOS THAT HIGH STILL EXPECT
OCCASIONAL MODERATE SNOWFALL. HAVE SNOWFALL AMOUNTS OF 1 TO 4 INCHES
TODAY OVER THE FAVORED AREAS OVER THE FAR WESTERN U.P....WITH THE
GREATEST AMOUNTS OVER THE HIGHER TERRAIN OF GOGEBIC/ONTONAGON
COUNTIES. ONE OTHER LIMITING FACTOR FOR TODAY IS THAT THERE WILL BE
ENOUGH BACKING OF THE WINDS FROM NORTH-NORTHWEST TO NORTHWEST TODAY
TO MOVE THE BANDS AROUND ENOUGH TO LIMIT THE RESIDENCE TIME OF THE
STRONGER BANDS IN ANY ONE LOCATION. FARTHER TO THE EAST...EXPECT
SOME LAKE ENHANCEMENT NEAR LAKE SUPERIOR THROUGH THE DAY WITH THE
NORTH AND EVENTUALLY NORTHWEST WINDS...BUT INVERSION STRUGGLE TO
RISE MUCH ABOVE 4KFT WITH LESS FAVORABLE MOISTURE. THUS...DON/T
EXPECT MUCH MORE THAN A LIGHT DUSTING TO AN INCH OF SNOW TODAY THERE
AND EXPECT SCATTERED SNOW SHOWERS AND MAYBE A DUSTING OF SNOW FOR
THE REST OF THE U.P. AS THE COLD FRONT MOVES THROUGH AND THE SNOW
SHOWERS IN WISCONSIN SLIDE EAST-NORTHEAST THROUGH THE AREA. FINALLY
FOR TEMPERATURES...EXPECT STEADILY FALLING TEMPERATURES THROUGH THE
DAY...WITH VALUES AROUND SUNSET RANGING FROM THE MID TEENS OVER THE
WEST AND UPPER 20S OVER THE EAST.
FOR TONIGHT...EXPECT THE LAKE EFFECT TO CONTINUE FOR AREAS NEAR LAKE
SUPERIOR AS THE WINDS VEER BACK TO A MORE NORTHERLY DIRECTION IN
RESPONSE TO A SURFACE RIDGE TRYING TO NOSE INTO THE AREA AND A
SURFACE LOW LIFTING NORTH INTO THE LOWER GREAT LAKES. 850MB TEMPS
CONTINUE TO FALL THROUGH THE NIGHT (DOWN TO -21C OVER THE
WEST)...PUSHING THE CLOUD LAYER OUT OF THE DGZ. THAT WILL TRANSITION
THE SNOW FLAKE SIZE AND RATIOS DOWN THROUGH THE NIGHT. INVERSION
HEIGHTS STILL STAY IN THE 5-6KFT RANGE...SO STILL EXPECT LIGHT TO
OCCASIONALLY MODERATE LAKE EFFECT TO OCCUR AND HAVE ANOTHER 1-4
INCHES OF SNOW FOR THE SAME AREAS OUT WEST. THE EAST WILL SEE A
COMBINATION OF TWO FEATURES FOR TONIGHT. FIRST...THE AREA WILL BE
BRUSHED BY SNOW ASSOCIATED WITH THE SURFACE LOW LIFTING NORTHEAST
THROUGH THE EASTERN GREAT LAKES. THE HEAVIEST SNOW WILL OCCUR JUST
TO THE SOUTHEAST OF THE AREA...BUT COULD SEE A LIGHT DUSTING OVER
SOUTHERN SCHOOLCRAFT AND SOUTHERN LUCE COUNTIES. THEN FOR THE LAKE
EFFECT AREAS CLOSER TO LAKE SUPERIOR...THINK THINGS WILL INTENSIFY
THROUGH THE NIGHT AS THE COLDER AIR FINALLY ARRIVES...RAISING
INVERSION HEIGHTS TO 5-6KFT AND PUTS THE CLOUD WITHIN THE DGZ.
EXPECT SNOWFALL AMOUNTS TO BE SIMILAR TO OUT WEST IN THE FAVORED
TIME COINCIDING WITH THE CLOUD IN THE DGZ WITH 1 TO 3 INCHES OF
SNOW. WHILE WINDS WILL BE PICKING UP OVER THE EAST...THINK THE AREA
WILL NEED SOME TIME TO ACCUMULATE SNOW (AFTER THE RAIN THIS EVENING)
BEFORE THE BLOWING SNOW WILL REALLY PICKUP.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 349 AM EST SAT JAN 9 2016
MEDIUM/EXTENDED RANGE GUIDANCE CONTINUES TO INDICATE A HI AMPLITUDE
WRN NAMERICA UPR RDG/ERN TROF WL DOMINATE THE COMING WEEK...
RESULTING IN BLO NORMAL TO WELL BLO NORMAL TEMPS FOR UPR MI MOST OF
THE TIME. LES WL BE COMMON DURING MUCH OF THIS TIME AS THE COLD
ARCTIC AIR FLOWS OVER THE RELATIVELY WARM WATERS OF LK SUP.
SUN...SINCE SHRTWV LIFTING NEWD FM THE LOWER MS RIVER VALLEY TOWARD
THE UPR OH RIVER VALLY AT 12Z SUN IS FCST TO REMAIN OUT OF PHASE
WITH ARCTIC BRANCH TROF SHIFTING INTO THE WRN GREAT LKS...ASSOCIATED
SFC LO AND BULK OF DYNAMIC SUPPORT ASSOCIATED WITH THE SHRTWV/
DEEPER MSTR/HEAVIER PCPN ARE FCST TO REMAIN MAINLY TO THE E OF THE
CWA. HOWEVER...AS CYC NNW SLOWLY BACK NW FLOW DRAWS H85 TEMPS IN THE
-20C TO -23C RANGE INTO THE UPR LKS...WL FCST CATEGORICAL POPS FOR
LES IN THE FAVORED SN BELTS NEAR LK SUP. BUT THE INTENSITY OF THIS
LES WL BE LIMITED BY RATHER LO INVRN BASE FCST NEAR H85 AND INCRSGLY
POOR SN GROWTH ASSOCIATED WITH THE ARRIVAL OF THE VERY COLD AIR THAT
WL PUSH THE DGZ TO NEAR THE SFC. DOWNSLOPE NATURE OF THE BACKING
LLVL NW FLOW WL BRING DRY WX TO THE SCENTRAL. WITH THE INFLUX OF THE
ARCTIC AIR...MAX TEMPS ON SUN WL HOLD IN THE SINGLE DIGITS ABOVE 0F
OVER MUCH OF THE W HALF.
SUN NGT/MON...NW LLVL WINDS AT 00Z MON ARE FCST TO BACK SLOWLY AS
THE DEEPENING SFC LO EXITS TO THE NE THRU QUEBEC AND COLD SFC HI
PRES IN THE PLAINS SHIFTS INTO THE LOWER MS RIVER VALLEY IN ADVANCE
OF ANOTHER SHRTWV WITHIN THE NW FLOW ALF DIGGING SEWD TOWARD THE UPR
MS RIVER VALLEY. H85 TEMPS ARE FCST TO MODERATE A FEW DEGREES TO
-18C TO -21C. ALTHOUGH THE INCRSG H85 TEMPS WL ALLOW FOR BETTER SN
GROWTH...THE SHIFTING WINDS SHOULD TEND TO LIMIT BAND RESIDENCE
TIME/PURE LES ACCUMS. HOWEVER...THERE MAY BE SOME MDT LES OVER NRN
ONTONAGON/CENTRAL HOUGHTON COUNTY WHERE MORE PERSISTENT LLVL CNVGC
WL BE ENHANCED ALONG A LK INDUCED TROF THAT IS FCST BY MANY OF THE
MODELS TO CROSS THE CENTRAL KEWEENAW PENINSULA AND PERHAPS OVER THE
FAR E FM GRAND MARAIS TO WHITEFISH PT. VERY COLD AIR TO THE S OF
THIS TROF...WITH MIN TEMPS -5F TO PERHAPS -10F...WL ALSO ACCENTUATE
LAND BREEZE CNVGC. TENDED TO BUMP UP QPF OVER CONSENSUS FCST IN THIS
AREA...WHERE AN LES HEADLINE WL LIKELY BE NECESSARY. RIGHT NOW...
LOOKS LIKE WIND CHILLS WL NOT FALL TO ADVY CRITERIA /-25F/ AS WINDS
WL BE LIGHTER OVER THE INTERIOR W WHERE MIN TEMPS WL BE LOWEST.
ALTHOUGH H85 TEMPS WL BE A FEW DEGREES HIER ON MON THAN ON SUN...A
MORE W WIND COMPONENT THAT LIMITS LK SUP MODERATION SUGGESTS MAX
TEMPS WL BE NO WARMER AND PERHAPS EVEN COLDER ON MON THAN SUN. THIS
MORE BACKED FLOW WL KEEP MUCH OF THE CWA DRY TO THE S OF THE MORE
DOMINANT LES BAND THAT MAY IMPACT NRN ONTONAGON/CENTRAL HOUGHTON
COUNTY AND PERHAPS THE FAR E NEAR LK SUP.
MON NGT/TUE...MEDIUM RANGE GUIDANCE IS COMING INTO BETTER AGREEMENT
ON TIMING/TRACK OF CLIPPER TYPE SHRTWV FCST TO DIG OVER NRN MN BY
00Z TUE...OVER THE LOWER GREAT LKS AT 12Z TUE AND THEN OVER SE
ONTARIO LATE ON TUE. ALTHOUGH THE ACCOMPANYING SFC LO IS PROGGED TO
PASS TO THE S THRU WI AND LOWER MI...MODELS SHOW LLVL W FLOW ON MON
EVNG BECOMING SHARPLY CYC AND VEERING TO THE NNW ON TUE...WHICH IS
PROGGED TO ADVECT H85 TEMPS AS LO AS -22C TO -24C BACK OVER UPR MI
BY LATER ON TUE. SINCE THE DEEP LYR QVECTOR CNVGC IS PROGGED TO
IMPACT UPR MI TO THE N OF THE SHRTWV TRACK...GFS FCST SDNGS SHOW
DEEP MOISTENING DESPITE LACK OF MSTR INFLOW INTO THE AREA AHEAD OF
THE SHRTWV THAT WL LIMIT QPF AWAY FM LK SUP MOISTENING. BUT LOOKS
LIKE A HEADLINE LK ENHANCED EVENT MAY BE IN THE WORKS FOR LATE MON
NIGHT THRU MUCH OF TUE FOR THE FAVORED AREAS IMPACTED BY THE LES OFF
LK SUP. GUSTY WINDS AND INCRSGLY SMALL SN FLAKES ASSOCIATED WITH
DESCENDING DGZ MAY ALSO RESULT IN SOME VERY LO VSBYS.
EXTENDED...ON WED...WINDS WL BACK AGAIN TO A MORE W DIRECTION AS HI
PRES TRAILING THE DEPARTING CLIPPER SHRTWV SHIFTS FM THE NRN PLAINS
INTO THE OH RIVER VALLEY. WITH THE BACKING FLOW...THE PURE LES WL
BECOME MORE RESTRICTED TO THE KEWEENAW AND AREAS NEAR LK SUP FM
GRAND MARAIS TO WHITEFISH PT. SOME OF THE LONGER RANGE GUIDANCE
HINTS ANOTHER SHRTWV/SFC LO WL APRCH LATER WED/THU...WITH WAA BAND
OF SN ARRIVING TO THE N OF ASSOCIATED WARM FNT...FOLLOWED BY SOME
LES ON FRI AS A MORE MODERATELY COLD AIRMASS RETURNS. BUT EXPLICIT
MODELS SHOW CONSIDERABLE VARIABILITY DURING THIS LATE WEEK PERIOD...
SO DID NOT STRAY FM CONSENSUS FCST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1254 PM EST SAT JAN 9 2016
LOOK FOR CONTINUED DETERIORATED CONDITIONS AT ALL SITES THROUGH THE
PERIOD...AS COLD AIR MOVING INTO THE AREA LEADS TO A PROLONGED
PERIOD OF LAKE EFFECT SNOW BEHIND A SERIES OF LOW PRESSURE SYSTEMS
TO OUR E AND HIGH PRESSURE SET UP ACROSS THE N AND CENTRAL PLAINS.
CEILINGS HAVE FALLEN TO MVFR TO HIGH END IFR /LOWEST AT IWD WHERE
THE FAVORABLE NW WINDS HAVE TAKEN HOLD. CONTINUED CALM WINDS REPORTED
AT IWD LOOK TO BE A CONTINUED TECHNICAL ISSUE FROM THE SITE. HAVE
EDITED THE LAST LINE OF THE TAF TO AMD LTD TO CLD AND VIS.
TEMPORARILY BLSN COULD BE A POSSIBILITY LATE TONIGHT THROUGH SUNDAY
MAINLY AT CMX AND SAW...WHERE THE PRESSURE GRADIENT REMAINS
STRONGEST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 AM EST SAT JAN 9 2016
A BROAD SURFACE LOW OVER NORTHERN LAKE MICHIGAN WILL CONTINUE
NORTHEAST AND SLOWLY DISSIPATE TODAY WHILE A SECONDARY LOW TAKES
SHAPE IN THE SOUTHERN PLAINS. WINDS HAVE ALREADY SHIFTED TO THE
NORTHWEST OVER THE WESTERN HALF OF THE LAKE AND EXPECT THAT WIND
SHIFT TO SLIDE EAST ACROSS THE REST OF THE LAKE THROUGH THE MORNING
HOURS. AT THIS POINT...ONLY EXPECT WINDS UP TO 30KTS THROUGH THIS
EVENING...BUT AS THE SECONDARY LOW LIFTS NORTHEAST THROUGH THE
SOUTHEASTERN GREAT LAKES LATE TONIGHT AND SUNDAY MORNING...THE
GRADIENT BETWEEN THE LOW AND THE HIGH IN THE CENTRAL/NORTHERN
PLAINS WILL PRODUCE OCCASIONAL NORTHERLY GALES TO 35KTS OVER THE
EASTERN HALF OF LAKE SUPERIOR. WITH ONLY MARGINAL GALES
EXPECTED...WILL KEEP THE GALE WATCH IN PLACE AND ALLOW THE DAY
SHIFT ONE FINAL LOOK TO SEE IF THE MODELS CONTINUE TO TREND WINDS
DOWN. ALSO EXPECT A PERIOD OF FREEZING SPRAY AND MAY NEED A HEAVY
FREEZING SPRAY WARNING IF THE WINDS/WAVES STAY AT THE CURRENTLY
FORECASTED LEVELS. THE WINDS WILL QUICKLY DIMINISH SUNDAY NIGHT AS
THE LOW DEPARTS...BUT ANOTHER LOW WILL QUICKLY DROP SOUTHEAST ACROSS
THE UPPER GREAT LAKES MONDAY NIGHT AND BRING ANOTHER POTENTIAL FOR
NORTHERLY GALES TUESDAY INTO TUESDAY EVENING. BEHIND THE LOW...A
HIGH PRESSURE RIDGE WILL MOVE INTO THE AREA FOR WEDNESDAY AND
DIMINISH WINDS BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT FOR
LSZ249>251-266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...KF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1126 AM EST SAT JAN 9 2016
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 254 AM EST SAT JAN 9 2016
A WINTER STORM WILL AFFECT THE REGION AS RAIN CHANGES TO SNOW THIS
EVENING AND OVERNIGHT. A RAPID FALL IN TEMPERATURES WILL CAUSE A
QUICK FREEZE UP ON AREA ROADS THIS EVENING. AREAS NORTH AND WEST OF
GRAND RAPIDS CAN EXPECT 4 TO 8 INCHES OF SNOW...WHILE AREAS SOUTH
AND EAST OF GRAND RAPIDS WILL SEE 1 TO 5 INCHES OF SNOW. ALONG WITH
THE SNOW...WINDS WILL INCREASE LATE SATURDAY NIGHT AND CONTINUE INTO
SUNDAY. NORTHWEST WINDS WILL GUST TO 30-35 MPH CAUSING BLOWING AND
DRIFTING SNOW.
ANOTHER ROUND OF ACCUMULATING SNOW APPEARS LIKELY MONDAY NIGHT INTO
TUESDAY NIGHT. IT SHOULD REMAIN COLD ALL NEXT WEEK WITH DAYTIME
HIGHS ONLY 20 TO 25.
&&
.UPDATE...
ISSUED AT 1114 AM EST SAT JAN 9 2016
HAD TO TWEAK SNOWFALL AMOUNTS A BIT ACROSS THE CENTRAL FORECAST
AREA TO LINE UP BETTER WITH ADJACENT OFFICES. ADDED CALHOUN COUNTY
TO THE WINTER WEATHER ADVISORY FOR BETTER CONTINUITY.
STILL LOOKING AT A SHARP SNOWFALL GRADIENT SETTING UP OVER THE
CENTRAL OR EASTERN FORECAST AREA...BUT FALLING TEMPERATURES BEHIND
THE ARCTIC FRONT SHOULD CAUSE ENOUGH ICY TRAVEL CONDITIONS TO
JUSTIFY THE ADVISORY ACROSS MUCH OF THE EASTERN FORECAST ZONES
WHERE ACTUAL SNOW AMOUNTS BY SUNDAY EVENING COULD END UP BEING IN
THE 1 TO 2 INCH RANGE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 254 AM EST SAT JAN 9 2016
WILL ISSUE A WINTER STORM WARNING FOR THE NW HALF OF THE CWA FOR
TONIGHT AND SUNDAY. THIS WILL BE BORDERED BY AN ADVISORY TO IT/S SE.
POTENT LOW PRESSURE REMAINS ON TRACK TO IMPACT MUCH OF LOWER
MICHIGAN. CONFIDENCE REMAINS HIGH AS THE MODELS HAVE STUCK TO A
VERY SIMILAR SOLUTION FOR THE PAST 24-36 HOURS. THE STORM PATH
REMAINS INTACT...ALTHOUGH IT APPEARS SLIGHT QUICKER...REACHING JUST
WEST OF ERIE PA BY 12 SUNDAY.
THE KEY ELEMENT TO THE FORECAST WILL BE THE TEMP TREND. MODELS
SEEMS TOO WARM AS THE PCPN SETTLES IN LATE THIS AFTERNOON. UPSTREAM
OBS BACK THIS UP. IF THIS HOLDS WE WILL SEE A QUICKER CHANGE OVER
TO SNOW...AND THEREFORE HIGHER SNOW TOTALS. I BELIEVE THIS COOLER
TREND WILL HOLD FOR THE NW CWA...HOWEVER IT APPEARS THE SE WILL
STRUGGLE TO COOL AS THE SYSTEM BRINGS A SURGE OF WARM GULF AIR
THERE. SO EXPECT WE WILLS SEE A SHARP SNOW TOTALS ALONG A LINE FROM
ROUGHLY ALMA TO SOUTH HAVEN. NW OF THIS LINE THE PCPN TYPE BY EARLY
THIS EVENING SHOULD BE MAINLY SNOW...WHILE AREAS SE OF THE LINE ONLY
CHANGE OVER THROUGH TONIGHT. THEREFORE WILL ISSUE A WINTER STORM
WARNING FOR AREAS NW OF THE LINE...AN ADVISORY TO THE SE.
5TO8INCHESIN THE WARNING...3-5 IN THE ADVISORY. I WILL EXCLUDE
CALHOUN...INGHAM AND JACKSON COUNTIES WHERE ONLY 1-3 INCHES IS
EXPECTED.
THE QUICK FREEZE UP WILL BE A FACTOR IN THIS STORM CAUSING ROADS TO
ICE UP AS THE SNOW BEGINS. THE WINDS WILL BECOME A FACTOR AND IS
REALLY WHAT PUSHES THIS STORM INTO THE WARNING CATEGORY. GUST WILL
FREQUENTLY BE IN THE 30-35 MPH RANGE...AND EVEN A BIT HIGHER ALONG
THE COAST. THIS WILL CAUSE BLOWING AND DRIFTING SNOW...ESPECIALLY
AS TEMPS GET COLDER AND THE SNOW GET FLUFFIER. THE ABRUPT CHANGE IN
THE AREA/S CONDITIONS WAS ALSO A CONSIDERING FACTOR WITH THE
HEADLINES DECISIONS.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 254 AM EST SAT JAN 9 2016
AFTER 5 MONTHS OF UNUSUALLY WARM TEMPERATURES AND VERY LITTLE IN THE
WAY OF PERSISTENT COLD WEATHER... WE ARE IN FOR A MAJOR PATTERN
CHANGE. THIS WILL MEAN PERSISTENT LAKE EFFECT SNOW AND BELOW NORMAL
TEMPERATURES MOST OF THIS WEEK AND LIKELY BEYOND THAT. THE DAYS WITH
THE STRONGEST WINDS AND GREATEST LAKE EFFECT SNOW POTENTIAL ARE
TUESDAY THEN LATE WEDNESDAY INTO THURSDAY.
THANKS TO MASSIVE UPPER LEVEL BLOCKING WITH A CLOSED UPPER LEVEL
HIGH NORTH OF ALASKA AND A RIDGE (FORCED BY THE MJO BEING IN PHASE
8) ALONG THE WEST COAST WE WILL CONTINUE TO SEE THE NORTHERN STREAM
IMPACTING OUR WEATHER MOST OF THIS WEEK INTO NEXT WEEKEND. ACTUALLY
BY THURSDAY WE HAVE REX BLOCK OVER EASTERN NORTH AMERICA WITH AN
UPPER LEVEL HIGH OVER BAFFIN`S ISLAND AND ELONGATED CLOSED UPPER LOW
CENTERED OVER EASTERN CANADA. MEANWHILE THE WEST COAST RIDGE
PERSISTENT. SO WHAT WE WILL SEE IS A SERIES OF SHORTWAVES ROTATING
AROUND THE CANADIAN UPPER LOW THROUGH THIS WEEK THROUGH THIS COMING
WEEKEND. AS EACH COMES THROUGH THE INVERSION HEIGHT RISES AND LAKE
EFFECT SNOW WILL RAMP UP. THE FIRST OF THESE COMES THROUGH TUESDAY
MORNING THEN THE NEXT ONE IS WEDNESDAY NIGHT INTO THURSDAY MORNING.
AS THE SHORTWAVE THAT COMES FROM NORTH OF ALASKA (THIS MORNING)
DROPS INTO THE MEAN TROUGH IT HELPS CLOSE OFF AN UPPER LOW OVER
MICHIGAN BY TUESDAY EVENING. THAT RESULTS IN INVERSION HEIGHTS RISE
ABOVE 10000 FT TUESDAY MORNING AND THERE IS STRONG LIFT IN THE DGZ.
THIS WILL START AS SOUTHWEST FLOW EVENT AND TRANSITION INTO A WEST
FLOW EVENT TUESDAY DURING THE DAY. IT WILL BE WINDY IN THE AFTERNOON
WITH GUSTS TO 30 MPH MORE THAN POSSIBLE DUE TO THE SHIFTING SNOW
BANDS THE HEAVIEST SNOW WILL BE SOMEWHAT SPREAD OUT BUT THANKS TO
THE WEST WINDS DURING THE DAY TUESDAY THE BAND WILL STREAM INLAND
BETWEEN I-94 AND I-96. THE CIPS ANALOGS SHOW AT GREATER THAN 80 PCT
CHANCE OF MORE THAN 6 INCHES OF SNOW WEST OF US-131 FOR THIS EVENT.
THE NEXT SYSTEM THAT COMES THROUGH WEDNESDAY NIGHT INTO THURSDAY IS
NOT AS IMPRESSIVE BUT EVEN SO WE ARE STILL IN THE COLD AIR AND GFS
AND ECMWF ARE SHOWING GOOD LIFT AS THIS WAVE PASSES THROUGH. THIS
ONE SEEMS TO IMPACT THE SOUTHERN SECTIONS MORE THAN THE NORTHERN
ONES. EVEN SO... THE LAKE EFFECT SNOW WILL CONTINUE.
BEYOND THURSDAY THERE IS MODEL DISAGREEMENT AS TO HOW THE CANADIAN
UPPER LOW WOBBLES AROUND. THE ECMWF ROTATES ANOTHER CLOSED UPPER LOW
THOUGH THE AREA FRIDAY WHILE THE GFS HAS THAT SYSTEM STALLED OVER
NORTH DAKOTAS. WE WILL HAVE TO SEE LATER MODEL RUNS TO RESOLVE THAT
BUT ONE WAY OR THE OTHER IT WILL REMAIN COLDER THAN NORMAL AND
SIGNIFICANT SNOWFALL AMOUNTS SHOULD BE EXPECTED NEAR AND WEST OF US-
131 MONDAY AFTERNOON THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 700 AM EST SAT JAN 9 2016
I SEE TWO MAJOR AVIATION ISSUES TODAY. FIRST IS DENSE FOG. THEN WE
HAVE THE ISSUE OF RAIN CHANGING TO SNOW AND BLOWING SNOW WITH THE SYSTEM
TONIGHT INTO SUNDAY.
THE FOG HAS BEEN IN AND OUT OVERNIGHT (MOSTLY AT GRR)HOWEVER WE
CURRENTLY REMAIN IN THE CIRCULATION OF THE DEPARTING SURFACE LOW.
ONCE THAT SYSTEM LIFTS OUT OF THE AREA... AROUND 15Z OR SO...
WINDS WILL BECOME LIGHT AND VARIABLE AND I DO BELIEVE WE WILL SEE
THE FOG REALLY SET IN AND MOST OF OUR TAF SITES WILL SEE 1/2SM FG
FOR SEVERAL HOURS (SEEN ON THE RAP MODEL VISIBILITY FORECAST RUN
AFTER RUN OVERNIGHT).
BY 21Z OR SO THE DEVELOPING STORM TO OUR SOUTH WILL BE CLOSE
ENOUGH TO PUT US IN THE CIRCULATION OF THAT SYSTEM. THAT WILL
START THE RAIN AND INCREASE THE WIND...ENDING THE FOG. WE SHOULD
SEE ABOUT 12 HOURS OF MODERATE TO HEAVY PRECIPITATION AS THE
DEFORMATION ZONE OF THE SYSTEM PASSES OVERHEAD. THE HEAVIEST QPF
WILL BE JUST ON A LINE FROM SBN TO MOP. MEANWHILE THE RAIN/SNOW
LINE WILL MOVE EASTWARD...CHANGING THE RAIN TO SNOW AT MKG AND GRR BY
00Z...BUT IT MAY TAKE TILL 10Z FOR THAT RAIN TO SNOW LINE TO REACH
JXN. THIS IS SHOWN BY THE NUMEROUS RUNS OF THE RAP...HRRR...AND
GFS MODELS (ECMWF FOR THAT MATTER TOO). AS THE LOW DEEPENS WINDS
WILL INCREASE OUT OF THE NORTH AND WITH TEMPERATURES FALLING INTO
THE 20S BY 09Z OR SO... I WOULD EXPECT CONSIDERABLE BLOWING SNOW
TOO.
BOTTOM LINE...IFR /LIFR FOG THIS AFTERNOON.... THEN IFR RAIN TO
SNOW TONIGHT.
&&
.MARINE...
ISSUED AT 254 AM EST SAT JAN 9 2016
GALE WARNING HAS BEEN ISSUED AS WINDS RAMP UP QUICKLY LATE TONIGHT.
THE WINDS SHOULD SIMMER DOWN A BIT BY LATE SUNDAY EVENING AS THE
STORM PULLS AWAY.
&&
.HYDROLOGY...
ISSUED AT 1126 AM EST SAT JAN 9 2016
MINOR RIVER FLOODING CONCERNS EXIST AS WE HEAD THROUGH THE NEXT
SEVERAL DAYS. KEY QUESTIONS LINGER IN THE DETAILS...SUCH AS HOW
MUCH RUNOFF RESULTS FROM RAINFALL AND SNOWMELT...IN ADDITION TO
THE ONSET OF SUB-FREEZING TEMPERATURES.
GUIDANCE CONTINUES TO SUGGEST THAT RAINFALL WILL QUICKLY CHANGE TO
SNOW LATE THIS EVENING NEAR AND ALONG I-196...AS WELL AS NORTH AND
WEST OF GRAND RAPIDS. THE DIFFICULTY IN TIMING THIS TRANSITION
INCREASES FURTHER SOUTH AND EAST OF GRAND RAPIDS. THIS IS WHERE
MUCH OF THE CONCERN EXISTS FOR RIVERS TO HAVE QUICKER RESPONSES
AND POSSIBLY REACH/EXCEED BANKFULL. RAINFALL AND SNOWMELT HAS
ALREADY LED TO WITHIN BANK RISES AND IF MOISTURE REMAINS IN LIQUID
FORM FOR A LONGER PERIOD...WE MAY EASILY REACH BANKFULL.
FLOOD ADVISORIES HAVE BEEN ISSUED FOR EAGLE (EAGM4)...HOLT
(HHTM4)...MAPLE RAPIDS (MRPM4) AND IONIA (IONM4). CURRENT
FORECASTS INCLUDE 48HR PRECIP AND ARE RATHER CONSERVATIVE...ACCOUNTING
FOR FREEZE UP THAT MAY OCCUR QUICKER THAN EXPECTED JUST A FEW DAYS
AGO. ADDITIONAL SNOWFALL IS EXPECTED THROUGH THE WEEK WITH
TEMPERATURES THAT REMAIN BELOW FREEZING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST SUNDAY
FOR MIZ037>040-043>046-050-051-056-057-064-071.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
SUNDAY FOR MIZ052-058-059-065-066-072-073.
LM...GALE WARNING FROM 1 AM TO 7 PM EST SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...OSTUNO
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JAM
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1114 AM EST SAT JAN 9 2016
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 254 AM EST SAT JAN 9 2016
A WINTER STORM WILL AFFECT THE REGION AS RAIN CHANGES TO SNOW THIS
EVENING AND OVERNIGHT. A RAPID FALL IN TEMPERATURES WILL CAUSE A
QUICK FREEZE UP ON AREA ROADS THIS EVENING. AREAS NORTH AND WEST OF
GRAND RAPIDS CAN EXPECT 4 TO 8 INCHES OF SNOW...WHILE AREAS SOUTH
AND EAST OF GRAND RAPIDS WILL SEE 1 TO 5 INCHES OF SNOW. ALONG WITH
THE SNOW...WINDS WILL INCREASE LATE SATURDAY NIGHT AND CONTINUE INTO
SUNDAY. NORTHWEST WINDS WILL GUST TO 30-35 MPH CAUSING BLOWING AND
DRIFTING SNOW.
ANOTHER ROUND OF ACCUMULATING SNOW APPEARS LIKELY MONDAY NIGHT INTO
TUESDAY NIGHT. IT SHOULD REMAIN COLD ALL NEXT WEEK WITH DAYTIME
HIGHS ONLY 20 TO 25.
&&
.UPDATE...
ISSUED AT 1114 AM EST SAT JAN 9 2016
HAD TO TWEAK SNOWFALL AMOUNTS A BIT ACROSS THE CENTRAL FORECAST
AREA TO LINE UP BETTER WITH ADJACENT OFFICES. ADDED CALHOUN COUNTY
TO THE WINTER WEATHER ADVISORY FOR BETTER CONTINUITY.
STILL LOOKING AT A SHARP SNOWFALL GRADIENT SETTING UP OVER THE
CENTRAL OR EASTERN FORECAST AREA...BUT FALLING TEMPERATURES BEHIND
THE ARCTIC FRONT SHOULD CAUSE ENOUGH ICY TRAVEL CONDITIONS TO
JUSTIFY THE ADVISORY ACROSS MUCH OF THE EASTERN FORECAST ZONES
WHERE ACTUAL SNOW AMOUNTS BY SUNDAY EVENING COULD END UP BEING IN
THE 1 TO 2 INCH RANGE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 254 AM EST SAT JAN 9 2016
WILL ISSUE A WINTER STORM WARNING FOR THE NW HALF OF THE CWA FOR
TONIGHT AND SUNDAY. THIS WILL BE BORDERED BY AN ADVISORY TO IT/S SE.
POTENT LOW PRESSURE REMAINS ON TRACK TO IMPACT MUCH OF LOWER
MICHIGAN. CONFIDENCE REMAINS HIGH AS THE MODELS HAVE STUCK TO A
VERY SIMILAR SOLUTION FOR THE PAST 24-36 HOURS. THE STORM PATH
REMAINS INTACT...ALTHOUGH IT APPEARS SLIGHT QUICKER...REACHING JUST
WEST OF ERIE PA BY 12 SUNDAY.
THE KEY ELEMENT TO THE FORECAST WILL BE THE TEMP TREND. MODELS
SEEMS TOO WARM AS THE PCPN SETTLES IN LATE THIS AFTERNOON. UPSTREAM
OBS BACK THIS UP. IF THIS HOLDS WE WILL SEE A QUICKER CHANGE OVER
TO SNOW...AND THEREFORE HIGHER SNOW TOTALS. I BELIEVE THIS COOLER
TREND WILL HOLD FOR THE NW CWA...HOWEVER IT APPEARS THE SE WILL
STRUGGLE TO COOL AS THE SYSTEM BRINGS A SURGE OF WARM GULF AIR
THERE. SO EXPECT WE WILLS SEE A SHARP SNOW TOTALS ALONG A LINE FROM
ROUGHLY ALMA TO SOUTH HAVEN. NW OF THIS LINE THE PCPN TYPE BY EARLY
THIS EVENING SHOULD BE MAINLY SNOW...WHILE AREAS SE OF THE LINE ONLY
CHANGE OVER THROUGH TONIGHT. THEREFORE WILL ISSUE A WINTER STORM
WARNING FOR AREAS NW OF THE LINE...AN ADVISORY TO THE SE.
5TO8INCHESIN THE WARNING...3-5 IN THE ADVISORY. I WILL EXCLUDE
CALHOUN...INGHAM AND JACKSON COUNTIES WHERE ONLY 1-3 INCHES IS
EXPECTED.
THE QUICK FREEZE UP WILL BE A FACTOR IN THIS STORM CAUSING ROADS TO
ICE UP AS THE SNOW BEGINS. THE WINDS WILL BECOME A FACTOR AND IS
REALLY WHAT PUSHES THIS STORM INTO THE WARNING CATEGORY. GUST WILL
FREQUENTLY BE IN THE 30-35 MPH RANGE...AND EVEN A BIT HIGHER ALONG
THE COAST. THIS WILL CAUSE BLOWING AND DRIFTING SNOW...ESPECIALLY
AS TEMPS GET COLDER AND THE SNOW GET FLUFFIER. THE ABRUPT CHANGE IN
THE AREA/S CONDITIONS WAS ALSO A CONSIDERING FACTOR WITH THE
HEADLINES DECISIONS.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 254 AM EST SAT JAN 9 2016
AFTER 5 MONTHS OF UNUSUALLY WARM TEMPERATURES AND VERY LITTLE IN THE
WAY OF PERSISTENT COLD WEATHER... WE ARE IN FOR A MAJOR PATTERN
CHANGE. THIS WILL MEAN PERSISTENT LAKE EFFECT SNOW AND BELOW NORMAL
TEMPERATURES MOST OF THIS WEEK AND LIKELY BEYOND THAT. THE DAYS WITH
THE STRONGEST WINDS AND GREATEST LAKE EFFECT SNOW POTENTIAL ARE
TUESDAY THEN LATE WEDNESDAY INTO THURSDAY.
THANKS TO MASSIVE UPPER LEVEL BLOCKING WITH A CLOSED UPPER LEVEL
HIGH NORTH OF ALASKA AND A RIDGE (FORCED BY THE MJO BEING IN PHASE
8) ALONG THE WEST COAST WE WILL CONTINUE TO SEE THE NORTHERN STREAM
IMPACTING OUR WEATHER MOST OF THIS WEEK INTO NEXT WEEKEND. ACTUALLY
BY THURSDAY WE HAVE REX BLOCK OVER EASTERN NORTH AMERICA WITH AN
UPPER LEVEL HIGH OVER BAFFIN`S ISLAND AND ELONGATED CLOSED UPPER LOW
CENTERED OVER EASTERN CANADA. MEANWHILE THE WEST COAST RIDGE
PERSISTENT. SO WHAT WE WILL SEE IS A SERIES OF SHORTWAVES ROTATING
AROUND THE CANADIAN UPPER LOW THROUGH THIS WEEK THROUGH THIS COMING
WEEKEND. AS EACH COMES THROUGH THE INVERSION HEIGHT RISES AND LAKE
EFFECT SNOW WILL RAMP UP. THE FIRST OF THESE COMES THROUGH TUESDAY
MORNING THEN THE NEXT ONE IS WEDNESDAY NIGHT INTO THURSDAY MORNING.
AS THE SHORTWAVE THAT COMES FROM NORTH OF ALASKA (THIS MORNING)
DROPS INTO THE MEAN TROUGH IT HELPS CLOSE OFF AN UPPER LOW OVER
MICHIGAN BY TUESDAY EVENING. THAT RESULTS IN INVERSION HEIGHTS RISE
ABOVE 10000 FT TUESDAY MORNING AND THERE IS STRONG LIFT IN THE DGZ.
THIS WILL START AS SOUTHWEST FLOW EVENT AND TRANSITION INTO A WEST
FLOW EVENT TUESDAY DURING THE DAY. IT WILL BE WINDY IN THE AFTERNOON
WITH GUSTS TO 30 MPH MORE THAN POSSIBLE DUE TO THE SHIFTING SNOW
BANDS THE HEAVIEST SNOW WILL BE SOMEWHAT SPREAD OUT BUT THANKS TO
THE WEST WINDS DURING THE DAY TUESDAY THE BAND WILL STREAM INLAND
BETWEEN I-94 AND I-96. THE CIPS ANALOGS SHOW AT GREATER THAN 80 PCT
CHANCE OF MORE THAN 6 INCHES OF SNOW WEST OF US-131 FOR THIS EVENT.
THE NEXT SYSTEM THAT COMES THROUGH WEDNESDAY NIGHT INTO THURSDAY IS
NOT AS IMPRESSIVE BUT EVEN SO WE ARE STILL IN THE COLD AIR AND GFS
AND ECMWF ARE SHOWING GOOD LIFT AS THIS WAVE PASSES THROUGH. THIS
ONE SEEMS TO IMPACT THE SOUTHERN SECTIONS MORE THAN THE NORTHERN
ONES. EVEN SO... THE LAKE EFFECT SNOW WILL CONTINUE.
BEYOND THURSDAY THERE IS MODEL DISAGREEMENT AS TO HOW THE CANADIAN
UPPER LOW WOBBLES AROUND. THE ECMWF ROTATES ANOTHER CLOSED UPPER LOW
THOUGH THE AREA FRIDAY WHILE THE GFS HAS THAT SYSTEM STALLED OVER
NORTH DAKOTAS. WE WILL HAVE TO SEE LATER MODEL RUNS TO RESOLVE THAT
BUT ONE WAY OR THE OTHER IT WILL REMAIN COLDER THAN NORMAL AND
SIGNIFICANT SNOWFALL AMOUNTS SHOULD BE EXPECTED NEAR AND WEST OF US-
131 MONDAY AFTERNOON THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 700 AM EST SAT JAN 9 2016
I SEE TWO MAJOR AVIATION ISSUES TODAY. FIRST IS DENSE FOG. THEN WE
HAVE THE ISSUE OF RAIN CHANGING TO SNOW AND BLOWING SNOW WITH THE SYSTEM
TONIGHT INTO SUNDAY.
THE FOG HAS BEEN IN AND OUT OVERNIGHT (MOSTLY AT GRR)HOWEVER WE
CURRENTLY REMAIN IN THE CIRCULATION OF THE DEPARTING SURFACE LOW.
ONCE THAT SYSTEM LIFTS OUT OF THE AREA... AROUND 15Z OR SO...
WINDS WILL BECOME LIGHT AND VARIABLE AND I DO BELIEVE WE WILL SEE
THE FOG REALLY SET IN AND MOST OF OUR TAF SITES WILL SEE 1/2SM FG
FOR SEVERAL HOURS (SEEN ON THE RAP MODEL VISIBILITY FORECAST RUN
AFTER RUN OVERNIGHT).
BY 21Z OR SO THE DEVELOPING STORM TO OUR SOUTH WILL BE CLOSE
ENOUGH TO PUT US IN THE CIRCULATION OF THAT SYSTEM. THAT WILL
START THE RAIN AND INCREASE THE WIND...ENDING THE FOG. WE SHOULD
SEE ABOUT 12 HOURS OF MODERATE TO HEAVY PRECIPITATION AS THE
DEFORMATION ZONE OF THE SYSTEM PASSES OVERHEAD. THE HEAVIEST QPF
WILL BE JUST ON A LINE FROM SBN TO MOP. MEANWHILE THE RAIN/SNOW
LINE WILL MOVE EASTWARD...CHANGING THE RAIN TO SNOW AT MKG AND GRR BY
00Z...BUT IT MAY TAKE TILL 10Z FOR THAT RAIN TO SNOW LINE TO REACH
JXN. THIS IS SHOWN BY THE NUMEROUS RUNS OF THE RAP...HRRR...AND
GFS MODELS (ECMWF FOR THAT MATTER TOO). AS THE LOW DEEPENS WINDS
WILL INCREASE OUT OF THE NORTH AND WITH TEMPERATURES FALLING INTO
THE 20S BY 09Z OR SO... I WOULD EXPECT CONSIDERABLE BLOWING SNOW
TOO.
BOTTOM LINE...IFR /LIFR FOG THIS AFTERNOON.... THEN IFR RAIN TO
SNOW TONIGHT.
&&
.MARINE...
ISSUED AT 254 AM EST SAT JAN 9 2016
GALE WARNING HAS BEEN ISSUED AS WINDS RAMP UP QUICKLY LATE TONIGHT.
THE WINDS SHOULD SIMMER DOWN A BIT BY LATE SUNDAY EVENING AS THE
STORM PULLS AWAY.
&&
.HYDROLOGY...
ISSUED AT 134 PM EST FRI JAN 8 2016
THERE IS INCREASING CONCERN FOR MINOR RIVER FLOODING HEADING
THROUGH THE NEXT SEVERAL DAYS. RIVER RISES ARE LIKELY WITH A FEW
LOCATIONS THAT HAVE THE POTENTIAL TO REACH BANKFULL. THE MAIN
QUESTIONS TO BE ANSWERED HAVE TO DEAL WITH THE AMOUNT OF RUNOFF
DUE TO SNOWMELT AND RESULTING LIQUID PRECIPITATION THROUGH LATE
SATURDAY EVENING.
THE FIRST WAVE OF MOISTURE WILL MOVE THROUGH AHEAD OF A STORM
SYSTEM CURRENTLY OVER MISSOURI/ILLINOIS. RAINFALL POTENTIAL EXISTS
NOW THROUGH MUCH OF SATURDAY. THE KEY TO HOW QUICKLY RIVERS
RESPOND LIES IN THE DETAILS OF REALIZED TOTALS...LEADING UP TO THE
THE TRANSITION TO SNOW SATURDAY NIGHT. ONCE COLDER AIR MOVES IN
LATE SATURDAY INTO SUNDAY...SUB-FREEZING TEMPS MAY BRING A HALT TO
MUCH OF THE RUNOFF AS POTENTIAL RUNOFF FREEZES. PRECIPITATION IS
THEN EXPECTED TO REMAIN LARGELY LOCKED UP IN SNOW ACCUMULATIONS.
THE WEEK AHEAD WILL BRING ADDITIONAL SNOW ACCUMULATIONS...BUT
TEMPERATURES SHOULD BE WELL BELOW FREEZING THROUGH THURSDAY.
CONDITIONS WILL NEED TO BE MONITORED THROUGH THE NEXT FEW DAYS FOR
ANY RISES THAT HAVE THE POTENTIAL TO EXCEED BANKFULL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST SUNDAY
FOR MIZ037>040-043>046-050-051-056-057-064-071.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
SUNDAY FOR MIZ052-058-059-065-066-072-073.
LM...GALE WARNING FROM 1 AM TO 7 PM EST SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...OSTUNO
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...JAM
MARINE...JK
AREA FORECAST DISCUSSION
NWS DULUTH MN
324 PM CST SAT JAN 9 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 323 PM CST SAT JAN 9 2016
CONCERN FOR SHORT TERM IS SNOW SHOWERS ALONG SOUTH SHORE SNOW AND WIND
CHILLS/CLOUD COVER ACROSS REST OF FORECAST AREA.
CURRENT SURFACE ANALYSIS INDICATES FLURRIES/SNOW SHOWERS ACROSS
AREAS MAINLY EAST OF HIGHWAY 53. THERE ARE LOWER VISIBILITIES DUETO
HEAVIER SNOW SHOWERS ASX AND EAST ON HIGHWAY 2. THE FLURRIES/LIGHT
SNOW IS CAUSED BY AN UPPER LOW PRESSURE TROUGH MOVING THROUGH THE
FORECAST REGION. THIS FEATURE WILL CLEAR THE FORECAST REGION BY
THIS EVENING. DRIER AIR IS PUSHING IN FROM THE NORTHWEST THIS
AFTERNOON CLEARING THE SKIES WEST OF HIGHWAY 53. THIS CLEARING
TREND WILL CONTINUE INTO NORTHWEST WISCONSIN THIS EVENING WITH
THE ENTIRE REGION MAINLY CLEAR TO PARTLY CLOUDY BY LATE EVENING.
THE ONLY EXCEPTION WILL BE ALONG THE SOUTHSHORE WHERE LAKE EFFECT
SNOW SHOWERS WILL OCCUR.
THE LOWS WILL DROP DOWN FAR BELOW ZERO TONIGHT. AT DLH...IT WILL
BE THE SECOND LATEST DATE FOR THE FIRST RECORDED BELOW ZERO
TEMPERATURES DATING BACK TO 1870. THESE TEMPS WILL COMBINE WITH
NW WINDS OF 5 TO 15 MPH WILL CAUSE WIND CHILLS TO DROP TO THE -25
TO -30 RANGE. CURRENT WC ADVISORY LOOKS GOOD AND WILL NOT CHANGE
TIMING/COVERAGE.
THE RIDGE WILL DOMINATE THE WEATHER ACROSS THE FORECAST AREA ON
SUNDAY. SKIES WILL BE SUNNY TO PARTLY SUNNY EXCEPT FOR THE CLOUDS
ACROSS THE SOUTHSHORE WITH THE SNOW SHOWERS STILL CONTINUING.
ACCUMULATIONS IS STILL FORECAST TO BE IN THE 2-5 INCH RANGE
THROUGH SUNDAY EVENING. HIGH TEMPS AWAY FORM THE LAKE WILL BE IN
THE SINGLE FIGURES ABOVE AND BELOW ZERO.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 303 PM CST SAT JAN 9 2016
CLOSED LOW POSITIONED OVER HUDSON BAY WILL ALLOW FOR SEVERAL
SHORTWAVES TO ROTATE ACROSS THE REGION THE IN THE CYCLONIC FLOW. A
MODELS ARE IN GOOD AGREEMENT A VORT MAX DROPS OUT OF CANADA AND
SWEEPS OVER THE NORTHLAND MONDAY NIGHT THROUGH TUESDAY. HAVE
INCREASED POPS DURING THIS TIME AS LAPSE RATES BECOME FAVORABLE FOR
LIGHT SNOW SHOWERS. HOWEVER...AMOUNTS WILL BE LIGHT WITH GENERALLY
AROUND AND INCH ACROSS THE FORECAST AREA. FLURRIES TO A DUSTING OF
LIGHT SNOW WILL LINGER DURING THE DAY TUESDAY IN THE COLD AIR
ADVECTION REGIME WHERE 850HPA TEMPS HANG IN THE 25C RANGE. HAVE ALSO
INCREASED WINDS ABOVE SUPERBLEND GUIDANCE TO ACCOUNT FOR THE COLD AIR
ALOFT PRODUCING STEEP LOW LEVEL LAPSE RATES AND ADDITIONAL GUSTS
MONDAY NIGHT/TUESDAY.
ADDITIONAL SNOW SHOWERS ARE EXPECTED ALONG THE SOUTH SHORE OF LAKE
SUPERIOR THROUGH TUESDAY NIGHT...MAINLY OVER NORTHERN ASHLAND AND
IRON COUNTIES...WHERE WINDS AND TEMPS WILL BE FAVORABLE FOR LAKE
EFFECT/ENHANCED SNOW.
AN AREA OF CANADIAN HIGH PRESSURE BUILDS INTO THE DAKOTAS AND
WESTERN MINNESOTA TUESDAY...WITH THE RIDGE AXIS EXPECTED TO TRACK
OVER THE NORTHLAND DURING THE TUESDAY NIGHT/WEDNESDAY TIME FRAME.
DEPENDING ON TIMING AND ABILITY FOR SKIES TO CLEAR...OVERNIGHT LOW
TEMPS TUESDAY NIGHT INTO WEDNESDAY MORNING HAVE THE POTENTIAL TO
FALL INTO THE TEENS TO POSSIBLY AROUND 20 BELOW ZERO IN LOCATIONS
THAT CLEAR OUT AND WINDS DECOUPLE. WIND CHILL HEADLINES MAY BE
NEEDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1231 PM CST SAT JAN 9 2016
A TROUGH WILL MOVE THROUGH NORTHERN MINNESOTA AND INTO NORTHERN
WISCONSIN BY LATE TONIGHT. BEHIND THE TROUGH HIGH PRESSURE WILL
NUDGE ITS WAY INTO WESTERN WESTERN PORTIONS OF MINNESOTA. THIS
WILL RESULT IN MVFR CIGS UNTIL 20-00Z AT ALL TERMINALS EXCEPT FOR
KHYR WHERE MVFR CIGS WILL PERSIST THROUGH THE TAF CYCLE.
LIGHT SNOW AND FLURRIES ARE EXPECTED AT ALL SITES EXCEPT
KBRD...WHERE THE LATEST VIS SATELLITE SHOWS DRIER AIR ALREADY WORKING
ITS WAY INTO CENTRAL MINNESOTA. TRIED TO TIME THE ENDING OF SNOW
AT KDLH/KHIB/KINL BY THE LATEST OBS ALONG WITH THE RAP WHICH HAS
HAD BEST HANDLE ON THINGS. VISBY HAS DROPPED TO 1-5 SM WHERE
SNOWFALL IS OCCURRING...SO WILL SEE MUCH OF THE SAME BEFORE
20-00Z. AFTER THIS ALL SITES EXCEPT KHYR WILL BE VFR...WITH THE
MAIN CONCERN BEING SUSTAINED WINDS GREATER THAN 10 KTS OVERNIGHT
WITH SOME GUSTS.
KHYR WILL REMAIN MVFR THROUGH THE FORECAST WITH SOME IFR VISBY
REDUCTION FROM SNOW SHOWERS. UNSURE HOW WIDESPREAD SNOW SHOWERS
WILL BE AFTER 00Z AS DRIER AIR WORKS ITS WAY INTO THE REGION...SO
KEPT AT MVFR CIGS WITH VCSH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH -11 1 -10 7 / 0 0 10 20
INL -16 -3 -15 2 / 0 0 0 30
BRD -16 3 -10 9 / 0 0 0 40
HYR -8 3 -14 6 / 20 10 10 10
ASX 0 5 -5 8 / 40 30 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CST SUNDAY
FOR WIZ001-002-006>009.
MN...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 10 AM CST SUNDAY
FOR MNZ010>012-018>021-025-026-033>038.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CST SUNDAY FOR LSZ121-140-141-
146>148.
&&
$$
SHORT TERM...STEWART
LONG TERM...GRANING
AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
1231 PM CST SAT JAN 9 2016
.UPDATE...
ISSUED AT 1155 AM CST SAT JAN 9 2016
UPDATED TO ADD SCT SNOW SHOWERS TO THE TWIN
PORTS...NORTHSHORE...AND NW WI EXCEPT FOR THE SNOW BELT AREAS
WHERE LIKELY POPS ARE ALREADY THERE. THIS SNOW IS THE RESPONSE TO
A SHORT WAVE/UPPER LEVEL TROUGH MOVING THROUGH THE REGION. THE
SNOW WILL TAPER OFF THIS AFTERNOON AS DRIER AIR MOVES INTO THE
AREA.
UPDATE ISSUED AT 950 AM CST SAT JAN 9 2016
UPDATED TO EXPAND AREA OF FLURRIES ACROSS NE MN THROUGH MIDDAY.
OBSERVATIONS REPORT VISIBILITIES VARYING FROM 1.5 TO 5 MILES
ACROSS THE REGION. THIS SNOW IS IN RESPONSE TO A SHORT WAVE
MOVING ACROSS NORTHERN MN THIS MORNING. THERE IS CLEARING BEHIND
THE WAVE IN SOUTHERN CANADA BUT THAT WONT REACH THE WESTERN AREAS
UNTIL THIS AFTERNOON. ALSO INCREASED WINDS A FEW MPH ALONG THE
NORTHSHORE DUE TO OBSERVATIONS SHOW WINDS 15 TO 25 WITH GUSTS TO
NEAR 30 MPH. MODELS INDICATE THE WINDS WILL SLOW DECREASE THIS
AFTERNOON. ALSO ADJUSTED CLOUD COVER BASED ON TRENDS AND MODEL
FORECASTS. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 415 AM CST SAT JAN 9 2016
THE FIRST TRUE ARCTIC AIR OUTBREAK OVER THE UPPER MIDWEST WILL
FINALLY OCCUR THIS WEEKEND AFTER A VERY MILD WINTER THUS FAR. TEMPS
WILL FALL TONIGHT TO VALUES NOT SEEN SINCE LAST WINTER...MARCH 5
2015 TO BE EXACT. THIS COLD WILL NOT JUST BE A RETURN TO NORMAL BUT
A BOOMERANG FROM WELL ABOVE NORMAL TO WELL BELOW NORMAL...WITH LOWS
TONIGHT FALLING TO AROUND 10 DEGREES BELOW NORMAL AND HIGHS SUNDAY
AROUND 15 DEGREES BELOW NORMAL. /THIS COMPARED HIGHS AND LOWS 13 TO
14 DEGREES ABOVE NORMAL YESTERDAY AT DLH AND INL./ PRECIPITATION
CHANCES WILL BE LIMITED TO THE SOUTH SHORE OF LAKE SUPERIOR WHERE
LAKE EFFECT SNOW SHOWERS WILL PERSIST THROUGH MOST OF THE WEEKEND
AND RESULT IN LIGHT BUT LONG-LASTING SNOW SHOWERS...ACCUMULATING 1
TO 5 INCHES ALONG FAVORED AREAS OF THE BAYFIELD PENINSULA AND
ESPECIALLY ACROSS THE GOGEBIC RANGE IN NORTHERN IRON/ASHLAND
COUNTIES.
ON THE SYNOPTIC SCALE A FAIRLY STRAIGHTFORWARD SET UP WITH AN UPPER
LOW OVER HUDSON BAY AND AN UPPER RIDGE OVER THE WEST COAST RESULTING
IN NORTHWEST FLOW OVER THE NORTHWEST TERRITORIES...CANADIAN
PRAIRIE...AND NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY. THIS WILL
ALLOW A SERIES OF ARCTIC AIR MASSES TO MOVE ACROSS THE REGION. WHILE
THERE ARE STILL FORECAST CHALLENGES WHICH WILL DICTATE JUST HOW FAR
TEMPS WILL FALL...CONFIDENCE IS OVERALL VERY HIGH...THE COLD IS
COMING.
TODAY A MID-LEVEL TROUGH AXIS ASSOCIATED WITH THE UPPER LOW OVER
HUDSON BAY WILL MOVE EAST ACROSS EASTERN NORTH DAKOTA AND NORTHERN
MINNESOTA AHEAD OF THE FIRST ROUND OF ARCTIC AIR. AS THIS TROUGH
AXIS MOVES ACROSS THERE HAS BEEN ENOUGH PVA AND THE NECESSARY MID-
LEVEL MOISTURE TO SUPPORT SNOW SHOWERS/FLURRIES ACROSS NORTHEAST
MINNESOTA THIS MORNING...THROUGH AS DRIER AIR MOVES IN TOWARDS MID
MORNING TODAY THIS LIGHT PRECIP WILL COME TO AN END. A SFC HIGH
PRESSURE MOVES ACROSS THE MISSOURI RIVER VALLEY INTO THE CENTRAL
PLAINS TODAY INTO TONIGHT...WITH THE INCREASED PRESSURE GRADIENT
FROM THE DEPARTING LOW OVER THE UPPER GREAT LAKES RESULTING IN
BREEZY WINDS THIS MORNING...WINDS WILL GRADUALLY DIMINISH FROM WEST
TO EAST INTO TONIGHT.
THE BIGGEST FORECAST CHALLENGE IS THE CLOUD COVER LATE TODAY INTO
TONIGHT. AS THE HIGH PRESSURE BUILDS TO THE WEST CLOUDS SHOULD CLEAR
OUT SAVE FOR SOME MID-LEVEL CLOUDS THAT MOVE ACROSS THE BORDERLAND
TONIGHT INTO SUNDAY MORNING ASSOCIATED WITH THE AFOREMENTIONED MID-
LEVEL TROUGH AXIS. WHILE MOST GUIDANCE IS INDICATING CLEAR SKIES AT
FIRST GLANCE...LOOKING AT MODEL SOUNDINGS THERE IS ENOUGH MOISTURE
IN PROFILES TO INDICATE THAT STRATUS MAY PERSIST INTO TONIGHT OR IF
IT DOES CLEAR...REDEVELOP TOWARDS SUNDAY MORNING IN NORTH CENTRAL
MINNESOTA. NAM MOS HINTS TOWARDS THIS WHILE GFS MOST REMAINS
OPTIMISTIC ON A CLEAR...AND THUS VERY COLD...NIGHT. FOR THE LOW
TEMPS TONIGHT STARTED WITH A BLEND OF GUIDANCE BUT THEN USED OUR
CLOUD COVER AND WIND SPEED FORECASTS TO DRILL DOWN ON WHERE TEMPS
MAY FALL THE FURTHEST...BLENDING TOWARDS OUR INTERNAL ECMWF MOS
WHERE CLOUDS CLEAR AND WINDS MAY GO CALM FOR A TIME. /THE ECMWF AND
ITS MOS HAS BEEN VERY PERSISTENT IN COLD TEMPS...ESPECIALLY ACROSS
THE BORDERLAND WITH SEVERAL PAST RUNS HAVING LOWS TO 25 BELOW OR
COLDER./ ALSO DROPPED TEMPS ANOTHER DEGREE OR TWO IN THE
TRADITIONALLY COLDEST AREAS PER LOCAL RESEARCH.
IN THE END WENT WITH A SOLUTION SLIGHTLY COLDER THAN THE PREVIOUS
FORECAST BUT NOT BY MUCH. HIGHS TODAY NEAR ZERO FROM WALKER TO THE
BORDERLAND...SINGLE DIGITS ELSEWHERE IN NORTHEAST MINNESOTA INTO THE
TEENS IN NORTHWEST WISCONSIN. LOWS 10 TO 25 BELOW ZERO TONIGHT IN
NORTHEAST MINNESOTA...NEAR ZERO TO 10 BELOW ZERO IN NORTHWEST
WISCONSIN. AND ON SUNDAY AS THE COLDEST AIR DRIFTS EAST AS A WEAK
LOW DEVELOPS ACROSS THE NORTHERN PLAINS HIGHS WILL BE LIMITED TO
NEAR ZERO TO THE MID SINGLE DIGITS...COLDEST NORTH OF HIGHWAY 2 IN
NORTHEAST MINNESOTA.
BESIDES THAN THE COLD TEMPS AND RESULTING WIND CHILLS LAKE EFFECT
SNOW SHOWERS WILL BE A PERSISTENT FEATURE THROUGH MUCH OF THE
WEEKEND. ALONG THE SOUTH SHORE OF LAKE SUPERIOR ANYWHERE BETWEEN AN
INCH AND 5 INCHES WILL FALL ACROSS THE WEEKEND. SNOW SHOWERS THIS
MORNING MAY DIMINISH FOR A TIME AS LOW LEVEL WINDS TURN MORE
WESTERLY AHEAD OF THE MID-LEVEL TROUGH AXIS APPROACHING FROM THE
WEST...BUT AS THE TROUGH GETS CLOSER TO THE SOUTH SHORE LOW LEVEL
WINDS TURN NORTH-NORTHWESTERLY AND LAKE EFFECT SNOW SHOWERS WILL
RAMP UP. THIS IS EXPECTED TO OCCUR THIS EVENING AND WILL COINCIDE
WITH WHEN THE COLDEST AIR WILL BE OVER THE LAKE...850MB TEMPS -20 TO
-24C WITH FAVORABLE WIND DIRECTION FOR BOTH THE BAYFIELD PENINSULA
AND ESPECIALLY THE GOGEBIC RANGE. ANY MID-LEVEL MOISTURE ASSOCIATED
WITH THE TROUGH WILL ONLY AID IN SNOW SHOWER DEVELOPMENT. WITH THE
SNOWFALL OCCURRING OVER A LONG PERIOD OF TIME DO NOT ANTICIPATE ANY
KIND OF ADVISORY WILL BE NECESSARY FOR THIS SNOWFALL.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 415 AM CST SAT JAN 9 2016
THE EXTENDED PERIOD WILL BE DOMINATED BY CANADIAN LOW PRESSURE OVER
HUDSON BAY STRETCHING DOWN INTO THE NORTHLAND. IN ADDITION TO A
STRONG AND COLD NORTHERLY FLOW...THIS LOW WILL BRING A SUCCESSION OF
SHORTWAVES THROUGH THE REGION. ONE WILL BE HEADING THROUGH THE
REGION MONDAY AFTERNOON AND EVENING WITH ANOTHER ONE QUICKLY
FOLLOWING MONDAY NIGHT AND TUESDAY. A FEW MORE WEAKER ONES WILL
FOLLOW LATER IN THE WEEK...BUT CONFIDENCE ON WHERE AND EXACTLY
WHEN IS DIFFICULT WITH THIS SYSTEM AS THE GFS BRINGS A CLOSED LOW
OVER THE REGION LATE IN THE WEEK WHILE THE ECMWF IS MUCH MORE
PROGRESSIVE WITH THE UPPER LOW AND SWINGS IT INTO NEWFOUNDLAND BY
THE END OF THE WEEK...BUT STILL BRINGS SOME ENERGY THROUGH THE
REGION.
IN GENERAL THE COLD TREND WILL CONTINUE WITH SOME MINOR WARM UPS
FOLLOWED BY MORE COLD. THE FIRST SLIGHT WARM UP WILL BE SUNDAY NIGHT
AS A SHOT OF WARM AIR ADVECTION OCCURS IN THE RETURN FLOW AS HIGH
PRESSURE SLIDES EAST AND LOW PRESSURE ADVANCES FROM THE WEST. SUNDAY
NIGHT TEMPS WILL DROP QUICKLY...BUT THEN WILL REMAIN FAIRLY STEADY
OR SLIGHTLY RISE OVERNIGHT. ONCE THIS LOW PASSES THROUGH MONDAY
THERE WILL BE ANOTHER SHOT OF VERY COLD AIR ARRIVING ON BRISK
NORTHWEST WINDS FOR TUESDAY. THIS LOW WILL BE A QUICK MOVING AND
FAIRLY DRY LOW AS IT MOVES ACROSS IOWA AND SOUTHERN WISCONSIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1231 PM CST SAT JAN 9 2016
A TROUGH WILL MOVE THROUGH NORTHERN MINNESOTA AND INTO NORTHERN
WISCONSIN BY LATE TONIGHT. BEHIND THE TROUGH HIGH PRESSURE WILL
NUDGE ITS WAY INTO WESTERN WESTERN PORTIONS OF MINNESOTA. THIS
WILL RESULT IN MVFR CIGS UNTIL 20-00Z AT ALL TERMINALS EXCEPT FOR
KHYR WHERE MVFR CIGS WILL PERSIST THROUGH THE TAF CYCLE.
LIGHT SNOW AND FLURRIES ARE EXPECTED AT ALL SITES EXCEPT
KBRD...WHERE THE LATEST VIS SATELLITE SHOWS DRIER AIR ALREADY WORKING
ITS WAY INTO CENTRAL MINNESOTA. TRIED TO TIME THE ENDING OF SNOW
AT KDLH/KHIB/KINL BY THE LATEST OBS ALONG WITH THE RAP WHICH HAS
HAD BEST HANDLE ON THINGS. VISBY HAS DROPPED TO 1-5 SM WHERE
SNOWFALL IS OCCURRING...SO WILL SEE MUCH OF THE SAME BEFORE
20-00Z. AFTER THIS ALL SITES EXCEPT KHYR WILL BE VFR...WITH THE
MAIN CONCERN BEING SUSTAINED WINDS GREATER THAN 10 KTS OVERNIGHT
WITH SOME GUSTS.
KHYR WILL REMAIN MVFR THROUGH THE FORECAST WITH SOME IFR VISBY
REDUCTION FROM SNOW SHOWERS. UNSURE HOW WIDESPREAD SNOW SHOWERS
WILL BE AFTER 00Z AS DRIER AIR WORKS ITS WAY INTO THE REGION...SO
KEPT AT MVFR CIGS WITH VCSH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 7 -11 2 -10 / 20 0 0 0
INL -1 -16 -1 -15 / 10 0 0 0
BRD 4 -16 4 -10 / 0 0 0 10
HYR 13 -8 3 -14 / 20 20 10 10
ASX 18 0 6 -5 / 40 40 30 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CST SUNDAY
FOR WIZ001-002-006>009.
MN...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 10 AM CST SUNDAY
FOR MNZ010>012-018>021-025-026-033>038.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CST SUNDAY FOR LSZ121-140-141-
146>148.
&&
$$
UPDATE...STEWART
SHORT TERM...JJM
LONG TERM...CLC
AVIATION...WL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
327 PM EST SAT JAN 9 2016
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA LATE IN THE DAY INTO
THIS EVENING. A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA
EARLY SUNDAY MORNING. SHOWERS AND SOME THUNDERSTORMS WILL REMAIN
IN THE FORECAST UNTIL THE FRONT SWEEPS TO OUR EAST. A SECONDARY
COLD FRONT WILL MOVE ACROSS THE AREA TUESDAY NIGHT. TEMPERATURES
WILL BE BELOW NORMAL FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SATURDAY...I CERTAINLY DIDN`T LIE ABOUT THIS BEING A
COMPLEX FORECAST. LOW STRATUS CLOUDS HAVE THINNED ENOUGH TO LET
THE SUN BURN THROUGH THEM ACROSS THE BURGAW/WILMINGTON/SOUTHPORT
VICINITY AND WE ARE ALREADY AT FORECAST HIGHS AT NOON. I HAVE
TACKED ON ANOTHER DEGREE TO WILMINGTON FORECASTING 67 HERE, WITH
66 AND 65 AT BURGAW AND SOUTHPORT RESPECTIVELY.
SHOWERS CONTINUE TO ADVANCE TOWARD THE COAST AND MAY BEGIN ROLLING
ONSHORE NORTH OF CAPE FEAR IN THE NEXT 90 MINUTES. WHILE
TECHNICALLY CONVECTIVE THEY LOOK MORE LIKE WARM CLOUD/COALESCENCE
RAIN ON RADAR AND I EXPECT THEY`LL DUMP A TENTH TO A QUARTER INCH
ALONG THE CAPE FEAR COAST LATE THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIP CHANCES FARTHER INLAND ARE LOOKING MUCH
POORER...AND I HAVE TRIMMED BACK POPS WITH EACH UPDATE WEST OF A
LINE FROM GEORGETOWN TO CONWAY TO LUMBERTON. WHERE WE CURRENTLY
STILL HAVE 50-70 POPS TONIGHT I MAY END UP TRIMMING THESE BACK
ANOTHER 20-30 PERCENT DEPENDING ON WHAT THE BAND OF PRECIP
ON/AHEAD OF THE COLD FRONT LOOKS LIKE IN A COUPLE HOURS. SEVERE
WEATHER IS LOOKING INCREASINGLY UNLIKELY AND I HAVE REMOVED
MENTION OF THIS FROM THE HAZARDOUS WEATHER OUTLOOK. DISCUSSION
FROM 930 AM FOLLOWS...
THIS IS A VERY COMPLEX FORECAST TODAY AND TONIGHT WITH PLENTY OF
OPPORTUNITY FOR ERROR. A WARM FRONT/COASTAL TROUGH NEAR THE
WESTERN EDGE OF THE GULF STREAM WILL WALK WESTWARD TOWARD THE
COAST...MOVING ONSHORE SOMETIME EARLY THIS EVENING. THE PRECISE
TIMING OF THE FRONTAL PASSAGE WILL HAVE ENORMOUS IMPACTS ON
TEMPERATURES TODAY.
WEST OF THE FRONT THERE IS A THIN BUT EXPANSIVE DECK OF LOW
STRATUS WITH PATCHIER CIRRUS ALOFT. VISIBLE SATELLITE, WEBCAMS,
AND A LOOK OUT THE WINDOW REVEALS THERE ARE SOME THIN SPOTS IN
THIS LOW STRATUS CURRENTLY. WITH VAD WIND PROFILES INDICATING EAST
AND SOUTHEAST WINDS DOWN AS LOW AS 1000 FEET AGL...IT WON`T TAKE
MUCH TO ERODE THE THIN LAYER OF NE WINDS AND "JUMP" THE FRONT
ONSHORE. FORECAST HIGHS RANGE FROM THE MID 60S IN THE WILMINGTON
AREA WITH LOWER 60S ALONG THE COAST WEST OF CAPE FEAR. HIGHS
SHOULD REACH THE UPPER 50S TO AROUND 60 INLAND. ALL OF THESE
TEMPERATURES WILL BE ACHIEVED VERY LATE IN THE DAY AS WARM
ADVECTION MAY BE MORE IMPORTANT THAN INSOLATION.
AS IS TYPICAL, MODELS PAINT A VARIETY OF FORECAST POSITIONS FOR
THE FRONT. THE 06Z NAM WAS THE FASTEST TO BRING THE FRONT IN,
WHILE THE 00Z ARW-NMM WAS THE SLOWEST. AN MEDIAN TIME WAS JUST
AFTER SUNSET ALONG THE EAST-FACING BEACHES OF CAPE FEAR, WITH
WINDS TURNING SOUTHERLY THROUGHOUT THE AREA INCLUDING FAR INLAND
DURING THE EVENING HOURS AS THE COLD FRONT OFF THE WEST BECOMES
THE PRIMARY FEATURE AFFECTING THE PRESSURE GRADIENT AND LOW-LEVEL
WINDS.
RADAR/SATELLITE IMAGES SHOWS WAVES OF SHOWERS DEVELOPING OVER THE
GULF STREAM MOVING NORTHWESTWARD. THE HRRR AND HRRRX MODELS BOTH
SHOW THESE IMPACTING THE COAST THIS AFTERNOON BEGINNING BETWEEN
2-4 PM. POPS HAVE BEEN INCREASED TO 50-80 PERCENT DURING THE
AFTERNOON HOURS. PRECIP CHANCES INLAND ARE LESS CERTAIN GIVEN MUCH
LESS ATLANTIC TRANSPORT OF MOISTURE THAT FAR WEST PLUS OVERALL
WEAK FORCING. MEASURABLE RAIN OVER THE INLAND PEE DEE REGION WILL
PROBABLY FOCUS MORE ON ANY PRECIP AHEAD OF THE COLD FRONT LATE
TONIGHT.
SEVERE WEATHER POTENTIAL APPEARS QUITE LIMITED GIVEN SURFACE-BASED
INSTABILITY REMAINING NEAR ZERO TODAY AND TONIGHT. ALTHOUGH
ELEVATED INSTABILITY MAY GROW TO 400-600 J/KG...FAIRLY WEAK UPPER
LEVEL SUPPORT AND THE PRESENCE OF A LARGE DRY SLOT ALOFT THIS
EVENING WILL TEND TO REMOVE CONVECTION DURING THE TIME WHEN THE
BEST WIND SHEAR WILL BE PRESENT. WHILE I CANNOT RULE OUT SEVERE
WEATHER COMPLETELY, THIS DOES NOT APPEAR TO BE A VERY CONCERNING
SETUP AT THIS TIME.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...STRONG COLD FRONT COMES THROUGH TO START
THE PERIOD AND FOR A FEW DAYS NOW GETTING SUNDAY`S HIGH
TEMPERATURE SEEMS AWFULLY TRICKY AS IT WILL LIKELY BE IN THE
MORNING IF NOT PREDAWN. LINGERING COASTAL SHOWERS TO START THE
PERIOD, IF ANY, WILL QUICKLY SCOOT OFFSHORE IN THE STRONG COLD AND
DRY ADVECTION REGIME. 850 TEMPS PLUNGE TO ABOUT -2C SUNDAY NIGHT
BRINGING SOME SEASONABLE MID 30S AREA-WIDE. WITH NO REAL RECOVERY
IN LOW LEVEL THERMAL FIELDS ON MONDAY AFTERNOON HIGHS A SOLID
CATEGORY BELOW NORMAL WITH HIGHS IN THE MID TO UPPER 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE ON TUESDAY IS SUPPRESSED TO
OUR SOUTH AND WEST ON TUESDAY WITH THE APPROACH OF A STRONG UPPER
TROUGH AND MOISTURE-DEPRIVED COLD FRONT SLATED FOR A TUESDAY NIGHT
PASSAGE AFTER A SEASONABLE TO SLIGHTLY COOL TUESDAY TEMPERATURES
WILL TAKE A TURN DOWNWARD POSSIBLY FOR THE REMAINDER OF THE PERIOD
THOUGH MOST OF THE TIME CLOUD COVER WILL BE LOW END PARTLY CLOUDY
IF NOT LESS. THIS WILL CHANGE ON THURSDAY AS SOME MOISTURE STREAMS
IN ALOFT AHEAD OF A SOUTHERN BRANCH DISTURBANCE. THIS FEATURE MAY
BRING RAIN CHANCES ON FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...CLEARING LINE WORKING WESTWARD FROM SOUTHEAST NC
SHOULD WORK THROUGH ALL COASTAL TERMINALS IN THE NEXT 2 TO 4
HOURS AND RESULT IN PREVAILING VFR CONDITIONS WITH TEMPO MVFR
CIGS DUE TO SHRA AND THE ASSOCIATED CIGS THIS AFTERNOON INTO
TONIGHT. INLAND TAF SITES LIKELY TO RETAIN IFR CIGS UNTIL WARM
FRONTAL PASSAGE IN THE 04Z TO 08Z WINDOW BUT SHOWERS
COULD RESULT IN MVFR CONDITIONS AFTER PREDOMINANT IFR LIFTS.
WINDS WILL SHIFT FROM NE TO E AT 5 TO 10 KT TO SE TO S AFTER
THE WARM FRONT LIFTS THROUGH. VFR CONDITIONS EXPECTED ALL
TERMINALS ON SW FLOW AFT 12Z THE 10TH.
EXTENDED OUTLOOK...EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM SATURDAY...FEW CHANGES ARE NEEDED WITH THIS NOON
UPDATE. LIGHT SHOWERS HAVE ALREADY MOVED INTO THE WATERS NORTH OF
CAPE FEAR AND WILL REACH THE REMAINDER OF THE WATERS SOUTH OF CAPE
FEAR BY LATE THIS AFTERNOON/EARLY THIS EVENING. WE ARE SEEING SOME
HEAVIER SHOWERS AND THUNDERSTORMS OUT OVER THE GULF STREAM...SOME
OF WHICH MAY MAKE IT INSIDE 20 MILES BY SUNSET. WINDS/SEAS ARE
IN-LINE WITH PREVIOUS FORECASTS. DISCUSSION FROM 930 AM FOLLOWS...
A WARM FRONT/COASTAL TROUGH NEAR THE WESTERN EDGE OF THE GULF
STREAM WILL MOVE WESTWARD TODAY, REACHING THE COAST OF CAPE FEAR
EARLY THIS EVENING. THE FRONT SHOULD THEN JUMP INLAND ALLOWING
WINDS TO BECOME SOUTHERLY ALONG THE SOUTH CAROLINA COAST TOO.
UNTIL THEN, NORTHERLY WINDS WILL CONTINUE ALONG THE COAST WITH
WIND SPEEDS UP TO 20 KNOTS AT TIMES IN A FAIRLY TIGHT PRESSURE
GRADIENT. THIS HAS BUILT SEAS UP TO 5 FEET NEAR AND NORTH OF CAPE
FEAR...AND AN EXERCISE CAUTION HEADLINE WILL REMAIN POSTED THERE
UNTIL 11 AM.
SHOWERS DEVELOPING OVER THE GULF STREAM ARE MOVING NORTHWESTWARD
AND SHOULD OVERSPREAD THE CAPE FEAR AREA AND MYRTLE BEACH WATERS
THIS AFTERNOON. ISOLATED THUNDERSTORMS ARE POSSIBLE TOO. AFTER A
LULL DURING THE EVENING HOURS, ANOTHER WAVE OF SHOWERS AND STORMS MAY
PUSH ACROSS THE AREA AHEAD OF THE COLD FRONT LATE TONIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...A HEALTHY COLD FRONT WITH APPRECIABLE
DYNAMICS ALOFT CROSSES EARLY SUNDAY. WIND AND SEAS SHOULD READILY
RAMP UP TO ADVISORY LEVELS WHERE THEY WILL REMAIN MUCH OF SUNDAY
NIGHT AS WINDS VEER TO W AND THEN NW. LATER SUNDAY NIGHT INTO
MONDAY WILL FEATURE A CONSIDERABLE DECREASE IN BOTH WIND AND SEAS
AS HIGH PRESSURE BUILDS INTO THE GULF STATES AND A RIDGE AXIS
POKES INTO THE CAROLINAS AND MID ATLANTIC REGION EASING THE
GRADIENT ALONG MOST OF THE EAST COAST.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...A VERY LIGHT GRADIENT IN PLACE ON TUESDAY
AS THE POST-FRONTAL HIGH SINKS INTO THE GULF STATES AND WEAKENS
CONSIDERABLY. A MODERATELY STRONG COLD FRONT COMES THROUGH TUESDAY
NIGHT WITH GOOD DYNAMICS IN THE LOW TO MID LEVELS FOR SOME FAIRLY
STRONG WINDS THAT COULD YIELD SCEC FOR EITHER WIND OR SEAS. THIS
POST-FRONTAL HIGH WILL NOT BE SO QUICK TO WEAKEN NOR ENTER THE
AREA ON WEDNESDAY KEEPING THE GRADIENT A BIT TIGHTER BUT PROBABLY
NOT TO WHERE HEADLINES WILL BE NEEDED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...RAN
MARINE...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
210 PM EST SAT JAN 09 2016
.SYNOPSIS... LOW PRESSURE WILL APPROACH THE AREA FROM THE WEST
TONIGHT. THE COLD FRONT WILL BLOW OFF THE COAST LATE TONIGHT AND
EARLY SUNDAY. COLD HIGH PRESSURE WILL ARRIVE FOR TONIGHT AND
MONDAY.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 240 AM SATURDAY...
THROUGH THIS MORNING... WIDESPREAD FOG AND THICK STRATUS ARE LIKELY
TO PERSIST WITHIN THE WEDGE REGIME... FEATURING A DAMMING SURFACE
HIGH CENTERED OFF THE CANADIAN MARITIMES NOSING SW INTO NC... CAPPED
BY WEAK BUT STEADY MOIST UPGLIDE. BLOCKED BY THE MOUNTAINS TO THE
WEST AND A FRONTAL ZONE WELL TO OUR SOUTH AND SE... THE WEDGE SHOULD
STAY LOCKED IN WELL INTO THE MORNING GIVEN THE STAGNANT SURFACE
AIR... PROFOUND CLOUD DEPTH... AND LACK OF ANY MECHANISM TO DISPERSE
IT IN THE VERTICAL. THE HRRR AND HRRR-X ARE STILL SHOWING INCREASING
FOG DENSITY THROUGH DAYBREAK... AND WHILE THIS IS FAR FROM CERTAIN
GIVEN THE EXTENT OF STRATUS... WILL KEEP A CLOSE EYE ON FOG
TRENDS... AND DENSE FOG ADVISORY MAY BE NEEDED THIS MORNING. THE
MOIST UPGLIDE DOESN`T APPEAR TO BE STRONG OR DEEP ENOUGH FOR
ANYTHING MORE THAN PATCHY DRIZZLE OVER THE NEXT SEVERAL HOURS... AND
OTHER FORCING MECHANISMS ARE LACKING AS WELL GIVEN THE DEPARTURE TO
OUR NE OF A BATCH OF MID LEVEL VORTICITY... SO POPS THROUGH THIS
MORNING WILL BE LOW. TEMPS WILL BE SLOW TO RISE THROUGH THE UPPER
40S AND LOW-MID 50S THIS MORNING.
MIDDAY TODAY THROUGH TONIGHT: THE ACTIVE SOUTHERN STREAM REACHES ITS
PEAK IMPACT ON THE SOUTHEAST STATES LATE THIS AFTERNOON AND TONIGHT
WITH PASSAGE OF A POTENT MID LEVEL SHORTWAVE TROUGH AND SURFACE LOW
TO OUR WEST AND NW... MOVING FROM THE LOWER MISS VALLEY NEAR MIDDAY
THROUGH THE TN AND ERN OH VALLEY THROUGH TONIGHT. WHILE THE CHANCE
OF EVERYONE SEEING AT LEAST SOME SHOWERS (AND PERHAPS A STORM OR
TWO... MORE ON THAT LATER) IS HIGH CONSIDERING THE PROJECTIONS OF
MUCH ABOVE NORMAL PW (0.90-1.20")... IT APPEARS THAT THE BULK OF THE
DYNAMIC FORCING FOR ASCENT WILL HOLD TO OUR WEST AND NORTH. THESE
MECHANISMS INCLUDES THE MID LEVEL DPVA WITH THE SHORTWAVE TROUGH AS
WELL AS THE STRONGEST UPPER DIVERGENCE WITH THE LEFT EXIT REGION OF
THE SUBTROPICAL JET... BOTH OF WHICH TAKE A PATH NW OF CENTRAL NC.
BUT THERE SHOULD STILL BE A STRONG INFLUX OF LOWER LEVEL MOISTURE...
FOCUSED INTO CENTRAL AND ERN NC OUT AHEAD OF A WEAK SURFACE LOW NOW
OVER SOUTH FLA AND EXPECTED TO TRACK NORTHWARD TODAY AND THROUGH
CENTRAL NC TONIGHT... DRAWING ENOUGH ATLANTIC MOISTURE INTO THE AREA
FOR A PERIOD OF CATEGORICAL POPS... FOCUSING LATE AFTERNOON THROUGH
TONIGHT... WITH GREATEST COVERAGE AND DURATION OCCURRING ACROSS THE
NRN AND ERN FORECAST AREA. AS THIS SURFACE LOW APPROACHES AND DRAWS
THE COASTAL WEDGE FRONT WESTWARD INTO THE NC COASTAL PLAIN THIS
EVENING/TONIGHT... WEAK INSTABILITY (PEAKING AT A MUCAPE OF ABOUT
500-1000 J/KG TONIGHT) ALONG WITH IMPRESSIVE DEEP LAYER SHEAR AOA 50
KTS COULD SUPPORT A FEW POCKETS OF STRONGER CONVECTION... MOST
LIKELY (ACCORDING TO THE LATEST MODEL RUNS) DURING THE EARLY TO MID
EVENING HOURS. IT`S UNCLEAR WHETHER OR NOT ANY WEAK INSTABILITY WILL
BE ACHIEVED DURING THE TIME OF GREATEST LOW LEVEL SHEAR (0-3 KM SRH
PREDICTED TO REACH 300-400 M2/S2 ON THE NAM AND ABOUT HALF THAT ON
THE GFS)... WHICH WOULD INFLUENCE THE THREAT OF SUPERCELLS. SUCH A
SCENARIO SEEMS UNLIKELY BUT THE POTENTIAL WILL BE MONITORED. IF
SURFACE DEWPOINTS OVER OUR EAST CLIMB INTO THE UPPER 50S TO AROUND
60 AS EXPECTED HOWEVER... WITH WINDS BECOMING MORE UNIDIRECTIONAL (A
STRAIGHTENING HODOGRAPH)... THERE COULD BE A RISK OF BOWING SEGMENTS
AND STRONG STRAIGHT LINE WINDS TONIGHT. WILL RESTRICT AN ISOLATED
MENTION OF THUNDER TONIGHT FROM RALEIGH EAST AND SOUTH... ALONG AND
EAST OF THE ANTICIPATED TRACK OF THE WEAK SURFACE LOW. THE
WARM/WEDGE FRONT WILL SHIFT BACK EAST OVER THE COASTAL PLAIN LATE
TONIGHT AS THE OCCLUDED FRONT APPROACHES. EXPECT HIGHS FROM THE
UPPER 40S TO NEAR 50 IN THE TRIAD TO NEAR 60 IN OUR FAR SE (CLINTON
TO GOLDSBORO). TEMPS SHOULD SLIP JUST A FEW DEGREES EARLY TONIGHT...
TO THE MID 40S NW TO MID-UPPER 50S SE... WITH STEADY TEMPS OR A
SLIGHT RISE OVERNIGHT. -GIH
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 245 AM SATURDAY...
CONSENSUS OF THE LATEST MODELS IS TO SHIFT THE FRONTAL ZONE AND
ATTENDANT PRECIP EAST OUT OF THE COASTAL PLAIN SUN MORNING... WITH
THE ONSET OF BRISK AND GUSTY SW WINDS... SHIFTING TO WESTERLY LATE
IN THE DAY... AS THE SECONDARY COLD FRONT (TRAILING THE POTENT
SURFACE LOW THAT WILL ACCOMPANY THE VORTICITY/UPPER DIVERGENCE MAX
UP THROUGH LAKE ERIE/LAKE ONTARIO) PUSHES EAST INTO THE AREA LATE.
LOW LEVEL THICKNESSES START TO DROP SUNDAY MORNING BUT WILL
INITIALLY BE OFFSET BY INCREASING SUNSHINE AND THE DELAY IN COLD AIR
ADVECTION. HIGHS SHOULD BE IN THE MID 50S TO LOWER 60S EARLY IN THE
DAY... WITH READINGS SLIPPING LATER IN THE DAY. WITH THE TIGHT MSLP
GRADIENT IN THE WAKE OF THE LAKE ERIE LOW... SUSTAINED WINDS OF 15-
20 KTS APPEAR LIKELY... WITH FREQUENT GUSTS TO AROUND 30 MPH... BOTH
LIGHTENING UP LATE IN THE DAY. MOSTLY CLEAR SUN NIGHT WITH
DIMINISHING WINDS AND WINDS BECOMING WNW AS COLDER AIR RUSHES IN.
LOWS 25-33. -GIH
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 210 PM SATURDAY...
IT APPEARS THAT A RELATIVELY DRY AND CHILLY PATTERN WILL PREVAIL
THIS WEEK. THE EXCEPTION MAY BE TOWARD THE END OF THE WEEK WHEN
UNCERTAINTY INCREASES SIGNIFICANTLY WITH THE MODELS.
THERE IS HIGH CONFIDENCE EARLY IN THE WEEK WITH HIGH PRESSURE
EXPECTED TO BRING SUNNY AND COLDER TEMPERATURES MONDAY. HIGHS
GENERALLY SHOULD BE A FEW DEGREES BELOW THE 30 YEAR NORMS. EXPECT
MOSTLY MID TO UPPER 40S.
TUESDAY AND WEDNESDAY... AN ARCTIC COLD FRONT WILL SURGE THROUGH THE
REGION TUESDAY AFTERNOON. A PERIOD OF MID AND HIGH CLOUDINESS CAN BE
EXPECTED MONDAY NIGHT INTO TUESDAY ASSOCIATED WITH THE MID/UPPER
TROUGH APPROACH AND COLD FRONTAL PASSAGE. THE PREDOMINATE W-NW FLOW
WILL KEEP ANY QPF OUT OF THE FORECAST EAST OF THE MOUNTAINS.
HIGHS TUESDAY SHOULD MODERATE BEFORE THE TRUE CAA ARRIVES LATE IN
THE DAY AND TUESDAY EVENING WHEN NW WINDS 10-20 MPH WITH GUSTS TO 30
MPH CAN BE EXPECTED. HIGHS GENERALLY 48-53 TUESDAY WITH FALLING
TEMPERATURES IN THE AFTERNOON INTO THE NW PIEDMONT. MUCH COLDER
TEMPERATURES WITH DIMINISHING WINDS WITH CLEAR SKIES ARE EXPECTED
TUESDAY NIGHT WITH LOWS 20-25. WEDNESDAY... SUNNY AND COLD WITH
HIGHS ONLY 37-42. LOWS WEDNESDAY NIGHT 18-25.
THURSDAY THROUGH SATURDAY... PLENTY OF DIFFERENCES IN THE MODELS
HANDLING THE SPLIT FLOW PATTERN WITH THE ACTIVE SOUTHERN STREAM AND
POTENTIAL INTERACTION WITH THE POLAR JET. ENSEMBLES SUGGEST A MORE
ACTIVE SUBTROPICAL JET WITH ENERGY TRACKING FROM THE PACIFIC INTO
THE SOUTHWEST STATES... THEN POSSIBLY INDUCING A SYSTEM ALONG THE
GULF COAST STATES LATE IN THE PERIOD. OPERATIONAL MODELS ARE ALL
OVER THE PLACE WITH A POTENTIAL SYSTEM. FOR NOW... WE WILL MAINTAIN
THE CURRENT FORECAST OF NEAR AVERAGE TEMPERATURES AND AN INCREASE IN
CLOUDINESS FRI-SAT. LOWS GENERALLY 25-30 AND HIGHS 45-50. OBVIOUSLY
THIS WILL CHANGE IF/WHEN A SYSTEM DOES DEVELOP AS FAR AS TEMPS AND
POP.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 610 AM SATURDAY...
HIGH CONFIDENCE IN ADVERSE AVIATION CONDITIONS TONIGHT THROUGH MUCH
OF THIS MORNING... WITH ONLY SLOW IMPROVEMENT THEREAFTER. A WEDGE OF
COOL HIGH PRESSURE WILL CONTINUE TO NOSE IN FROM THE NE AT THE
SURFACE... WHILE DEEP MOISTURE STREAMS INTO THE AREA JUST OFF THE
SURFACE. THIS WILL KEEP DEEP LOW IFR/LIFR CLOUDS OVER THE REGION
WITH WIDESPREAD IFR/LIFR FOG. THE STAGNANT AIR MASS AND CLOUD DEPTH
WILL KEEP THESE ADVERSE CONDITIONS LOCKED IN LONGER THAN USUAL THIS
MORNING... AS IT MAY BE THE NOON HOUR OR EARLY AFTERNOON BEFORE WE
ACHIEVE MVFR CONDITIONS AT CENTRAL NC AIRFIELDS. AN APPROACHING
STORM SYSTEM FROM THE SOUTH AND SW WILL THEN BRING INCREASING CHANCE
FOR SHOWERS AND ISOLATED STORMS STARTING MID-LATE THIS AFTERNOON AND
LASTING THROUGH TONIGHT... WITH CONDITIONS AGAIN DETERIORATING TO
IFR BY THIS EVENING. AVIATION INTERESTS SHOULD BE ALERT FOR STRONG
WINDS FROM THE SE AT 1500-3000 FT AGL PRECEDING THE FRONT TONIGHT.
THESE STRONG WINDS FROM THE SE JUST OFF THE GROUND WILL CONTINUE TO
INCREASE AND VEER TO SOUTHWESTERLY LATE TONIGHT INTO SUN MORNING.
LOOKING BEYOND 12Z SUN MORNING... POOR AVIATION CONDITIONS WILL
PERSIST UNTIL PASSAGE OF A COLD FRONT FROM WEST TO EAST EARLY SUN
MORNING. CLEARING SKIES AND A TREND TO VFR ARE EXPECTED SUNDAY...
ALTHOUGH STRONG GUSTY WINDS FROM THE WEST ARE LIKELY POST-FRONT. VFR
CONDITIONS ARE EXPECTED TO DOMINATE THROUGH WED... ALTHOUGH GUSTY
WINDS MAY RETURN WITH A DRY COLD FRONT PASSAGE TUE NIGHT/WED. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1226 PM EST SAT JAN 9 2016
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA LATE IN THE DAY INTO
THIS EVENING. A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA
EARLY SUNDAY MORNING. SHOWERS AND SOME THUNDERSTORMS WILL REMAIN
IN THE FORECAST UNTIL THE FRONT SWEEPS TO OUR EAST. A SECONDARY
COLD FRONT WILL MOVE ACROSS THE AREA TUESDAY NIGHT. TEMPERATURES
WILL BE BELOW NORMAL FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SATURDAY...I CERTAINLY DIDN`T LIE ABOUT THIS BEING A
COMPLEX FORECAST. LOW STRATUS CLOUDS HAVE THINNED ENOUGH TO LET
THE SUN BURN THROUGH THEM ACROSS THE BURGAW/WILMINGTON/SOUTHPORT
VICINITY AND WE ARE ALREADY AT FORECAST HIGHS AT NOON. I HAVE
TACKED ON ANOTHER DEGREE TO WILMINGTON FORECASTING 67 HERE, WITH
66 AND 65 AT BURGAW AND SOUTHPORT RESPECTIVELY.
SHOWERS CONTINUE TO ADVANCE TOWARD THE COAST AND MAY BEGIN ROLLING
ONSHORE NORTH OF CAPE FEAR IN THE NEXT 90 MINUTES. WHILE
TECHNICALLY CONVECTIVE THEY LOOK MORE LIKE WARM CLOUD/COALESCENCE
RAIN ON RADAR AND I EXPECT THEY`LL DUMP A TENTH TO A QUARTER INCH
ALONG THE CAPE FEAR COAST LATE THIS AFTERNOON INTO EARLY THIS
EVENING. PRECIP CHANCES FARTHER INLAND ARE LOOKING MUCH
POORER...AND I HAVE TRIMMED BACK POPS WITH EACH UPDATE WEST OF A
LINE FROM GEORGETOWN TO CONWAY TO LUMBERTON. WHERE WE CURRENTLY
STILL HAVE 50-70 POPS TONIGHT I MAY END UP TRIMMING THESE BACK
ANOTHER 20-30 PERCENT DEPENDING ON WHAT THE BAND OF PRECIP
ON/AHEAD OF THE COLD FRONT LOOKS LIKE IN A COUPLE HOURS. SEVERE
WEATHER IS LOOKING INCREASINGLY UNLIKELY AND I HAVE REMOVED
MENTION OF THIS FROM THE HAZARDOUS WEATHER OUTLOOK. DISCUSSION
FROM 930 AM FOLLOWS...
THIS IS A VERY COMPLEX FORECAST TODAY AND TONIGHT WITH PLENTY OF
OPPORTUNITY FOR ERROR. A WARM FRONT/COASTAL TROUGH NEAR THE
WESTERN EDGE OF THE GULF STREAM WILL WALK WESTWARD TOWARD THE
COAST...MOVING ONSHORE SOMETIME EARLY THIS EVENING. THE PRECISE
TIMING OF THE FRONTAL PASSAGE WILL HAVE ENORMOUS IMPACTS ON
TEMPERATURES TODAY.
WEST OF THE FRONT THERE IS A THIN BUT EXPANSIVE DECK OF LOW
STRATUS WITH PATCHIER CIRRUS ALOFT. VISIBLE SATELLITE, WEBCAMS,
AND A LOOK OUT THE WINDOW REVEALS THERE ARE SOME THIN SPOTS IN
THIS LOW STRATUS CURRENTLY. WITH VAD WIND PROFILES INDICATING EAST
AND SOUTHEAST WINDS DOWN AS LOW AS 1000 FEET AGL...IT WON`T TAKE
MUCH TO ERODE THE THIN LAYER OF NE WINDS AND "JUMP" THE FRONT
ONSHORE. FORECAST HIGHS RANGE FROM THE MID 60S IN THE WILMINGTON
AREA WITH LOWER 60S ALONG THE COAST WEST OF CAPE FEAR. HIGHS
SHOULD REACH THE UPPER 50S TO AROUND 60 INLAND. ALL OF THESE
TEMPERATURES WILL BE ACHIEVED VERY LATE IN THE DAY AS WARM
ADVECTION MAY BE MORE IMPORTANT THAN INSOLATION.
AS IS TYPICAL, MODELS PAINT A VARIETY OF FORECAST POSITIONS FOR
THE FRONT. THE 06Z NAM WAS THE FASTEST TO BRING THE FRONT IN,
WHILE THE 00Z ARW-NMM WAS THE SLOWEST. AN MEDIAN TIME WAS JUST
AFTER SUNSET ALONG THE EAST-FACING BEACHES OF CAPE FEAR, WITH
WINDS TURNING SOUTHERLY THROUGHOUT THE AREA INCLUDING FAR INLAND
DURING THE EVENING HOURS AS THE COLD FRONT OFF THE WEST BECOMES
THE PRIMARY FEATURE AFFECTING THE PRESSURE GRADIENT AND LOW-LEVEL
WINDS.
RADAR/SATELLITE IMAGES SHOWS WAVES OF SHOWERS DEVELOPING OVER THE
GULF STREAM MOVING NORTHWESTWARD. THE HRRR AND HRRRX MODELS BOTH
SHOW THESE IMPACTING THE COAST THIS AFTERNOON BEGINNING BETWEEN
2-4 PM. POPS HAVE BEEN INCREASED TO 50-80 PERCENT DURING THE
AFTERNOON HOURS. PRECIP CHANCES INLAND ARE LESS CERTAIN GIVEN MUCH
LESS ATLANTIC TRANSPORT OF MOISTURE THAT FAR WEST PLUS OVERALL
WEAK FORCING. MEASURABLE RAIN OVER THE INLAND PEE DEE REGION WILL
PROBABLY FOCUS MORE ON ANY PRECIP AHEAD OF THE COLD FRONT LATE
TONIGHT.
SEVERE WEATHER POTENTIAL APPEARS QUITE LIMITED GIVEN SURFACE-BASED
INSTABILITY REMAINING NEAR ZERO TODAY AND TONIGHT. ALTHOUGH
ELEVATED INSTABILITY MAY GROW TO 400-600 J/KG...FAIRLY WEAK UPPER
LEVEL SUPPORT AND THE PRESENCE OF A LARGE DRY SLOT ALOFT THIS
EVENING WILL TEND TO REMOVE CONVECTION DURING THE TIME WHEN THE
BEST WIND SHEAR WILL BE PRESENT. WHILE I CANNOT RULE OUT SEVERE
WEATHER COMPLETELY, THIS DOES NOT APPEAR TO BE A VERY CONCERNING
SETUP AT THIS TIME.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...STRONG COLD FRONT COMES THROUGH TO START
THE PERIOD AND FOR A FEW DAYS NOW GETTING SUNDAY`S HIGH
TEMPERATURE SEEMS AWFULLY TRICKY AS IT WILL LIKELY BE IN THE
MORNING IF NOT PREDAWN. LINGERING COASTAL SHOWERS TO START THE
PERIOD, IF ANY, WILL QUICKLY SCOOT OFFSHORE IN THE STRONG COLD AND
DRY ADVECTION REGIME. 850 TEMPS PLUNGE TO ABOUT -2C SUNDAY NIGHT
BRINGING SOME SEASONABLE MID 30S AREA-WIDE. WITH NO REAL RECOVERY
IN LOW LEVEL THERMAL FIELDS ON MONDAY AFTERNOON HIGHS A SOLID
CATEGORY BELOW NORMAL WITH HIGHS IN THE MID TO UPPER 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE ON TUESDAY IS SUPPRESSED TO
OUR SOUTH AND WEST ON TUESDAY WITH THE APPROACH OF A STRONG UPPER
TROUGH AND MOISTURE-DEPRIVED COLD FRONT SLATED FOR A TUESDAY NIGHT
PASSAGE AFTER A SEASONABLE TO SLIGHTLY COOL TUESDAY TEMPERATURES
WILL TAKE A TURN DOWNWARD POSSIBLY FOR THE REMAINDER OF THE PERIOD
THOUGH MOST OF THE TIME CLOUD COVER WILL BE LOW END PARTLY CLOUDY
IF NOT LESS. THIS WILL CHANGE ON THURSDAY AS SOME MOISTURE STREAMS
IN ALOFT AHEAD OF A SOUTHERN BRANCH DISTURBANCE. THIS FEATURE MAY
BRING RAIN CHANCES ON FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...CLEARING LINE WORKING WESTWARD FROM SOUTHEAST NC
SHOULD WORK THROUGH ALL COASTAL TERMINALS IN THE NEXT 2 TO 4
HOURS AND RESULT IN PREVAILING VFR CONDITIONS WITH TEMPO MVFR
CIGS DUE TO SHRA AND THE ASSOCIATED CIGS THIS AFTERNOON INTO
TONIGHT. INLAND TAF SITES LIKELY TO RETAIN IFR CIGS UNTIL WARM
FRONTAL PASSAGE IN THE 04Z TO 08Z WINDOW BUT SHOWERS
COULD RESULT IN MVFR CONDITIONS AFTER PREDOMINANT IFR LIFTS.
WINDS WILL SHIFT FROM NE TO E AT 5 TO 10 KT TO SE TO S AFTER
THE WARM FRONT LIFTS THROUGH. VFR CONDITIONS EXPECTED ALL
TERMINALS ON SW FLOW AFT 12Z THE 10TH.
EXTENDED OUTLOOK...EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM SATURDAY...FEW CHANGES ARE NEEDED WITH THIS NOON
UPDATE. LIGHT SHOWERS HAVE ALREADY MOVED INTO THE WATERS NORTH OF
CAPE FEAR AND WILL REACH THE REMAINDER OF THE WATERS SOUTH OF CAPE
FEAR BY LATE THIS AFTERNOON/EARLY THIS EVENING. WE ARE SEEING SOME
HEAVIER SHOWERS AND THUNDERSTORMS OUT OVER THE GULF STREAM...SOME
OF WHICH MAY MAKE IT INSIDE 20 MILES BY SUNSET. WINDS/SEAS ARE
IN-LINE WITH PREVIOUS FORECASTS. DISCUSSION FROM 930 AM FOLLOWS...
A WARM FRONT/COASTAL TROUGH NEAR THE WESTERN EDGE OF THE GULF
STREAM WILL MOVE WESTWARD TODAY, REACHING THE COAST OF CAPE FEAR
EARLY THIS EVENING. THE FRONT SHOULD THEN JUMP INLAND ALLOWING
WINDS TO BECOME SOUTHERLY ALONG THE SOUTH CAROLINA COAST TOO.
UNTIL THEN, NORTHERLY WINDS WILL CONTINUE ALONG THE COAST WITH
WIND SPEEDS UP TO 20 KNOTS AT TIMES IN A FAIRLY TIGHT PRESSURE
GRADIENT. THIS HAS BUILT SEAS UP TO 5 FEET NEAR AND NORTH OF CAPE
FEAR...AND AN EXERCISE CAUTION HEADLINE WILL REMAIN POSTED THERE
UNTIL 11 AM.
SHOWERS DEVELOPING OVER THE GULF STREAM ARE MOVING NORTHWESTWARD
AND SHOULD OVERSPREAD THE CAPE FEAR AREA AND MYRTLE BEACH WATERS
THIS AFTERNOON. ISOLATED THUNDERSTORMS ARE POSSIBLE TOO. AFTER A
LULL DURING THE EVENING HOURS, ANOTHER WAVE OF SHOWERS AND STORMS MAY
PUSH ACROSS THE AREA AHEAD OF THE COLD FRONT LATE TONIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...A HEALTHY COLD FRONT WITH APPRECIABLE
DYNAMICS ALOFT CROSSES EARLY SUNDAY. WIND AND SEAS SHOULD READILY
RAMP UP TO ADVISORY LEVELS WHERE THEY WILL REMAIN MUCH OF SUNDAY
NIGHT AS WINDS VEER TO W AND THEN NW. LATER SUNDAY NIGHT INTO
MONDAY WILL FEATURE A CONSIDERABLE DECREASE IN BOTH WIND AND SEAS
AS HIGH PRESSURE BUILDS INTO THE GULF STATES AND A RIDGE AXIS
POKES INTO THE CAROLINAS AND MID ATLANTIC REGION EASING THE
GRADIENT ALONG MOST OF THE EAST COAST.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...A VERY LIGHT GRADIENT IN PLACE ON TUESDAY
AS THE POST-FRONTAL HIGH SINKS INTO THE GULF STATES AND WEAKENS
CONSIDERABLY. A MODERATELY STRONG COLD FRONT COMES THROUGH TUESDAY
NIGHT WITH GOOD DYNAMICS IN THE LOW TO MID LEVELS FOR SOME FAIRLY
STRONG WINDS THAT COULD YIELD SCEC FOR EITHER WIND OR SEAS. THIS
POST-FRONTAL HIGH WILL NOT BE SO QUICK TO WEAKEN NOR ENTER THE
AREA ON WEDNESDAY KEEPING THE GRADIENT A BIT TIGHTER BUT PROBABLY
NOT TO WHERE HEADLINES WILL BE NEEDED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...RAN
MARINE...
AREA FORECAST DISCUSSION
NWS MEDFORD OR
916 AM PST SAT JAN 9 2016
.DISCUSSION...CURRENT RADAR SHOWS MOST OF THE PRECIPITATION IN
WESTERN SIKSYOU COUNTY THROUGH EASTERN JACKSON COUNTY AND
SOUTHWEST KLAMATH COUNTY AND MOVING EAST TO NORTHEAST. THE SHORT
TERM HRRR MODELS SUGGEST PRECIPITATION WILL GRADUALLY DECREASE
THIS AFTERNOON WITH MOST CONFINED TO NORTHERN CAL BY THIS EVENING.
HAVE ADJUSTED POPS AND QPF AMOUNTS HIGHER FOR NORTHERN CAL AND
EAST OF THE CASCADES THIS AFTERNOON. SNOW LEVELS WILL GRADUALLY
COME UP, BUT ONLY AROUND 4000 FEET. LIGHT SNOW IS EXPECTED TO
PERSIST INTO THE AFTERNOON NEAR OR ABOVE 4000 FEET, BUT ROAD
TEMPERATURES WILL WARM UP ENOUGH DURING THE DAY TO KEEP SNOW FROM
ACCUMULATING. CURRENT WINTER WEATHER ADVISORY IS DUE TO END AT 10
AM PST IN THE MOUNT SHASTA REGION WHICH LOOKS REASONABLE, SO
WE`LL LET IT EXPIRE. -PETRUCELLI
&&
.AVIATION...FOR THE 09/12Z TAF CYCLE...A WARM FRONT WILL BRING
WIDESPREAD RAIN TO SW OREGON THROUGH LATE THIS MORNING WITH
WIDESPREAD MVFR CIGS AND MOUNTAIN OBSCURATION. AREAS OF IFR CIGS
HAVE BEEN PERSISTENT ACROSS THE UMPQUA BASIN AND KRBG IS NOT
EXPECTED TO LIFT TO VFR UNTIL AROUND NOON. TO THE EAST EXPECT AREAS
OF IFR CIGS/VIS IN SNOW UNTIL MID MORNING...THEN CONDITIONS
IMPROVING TO MVFR CIGS. MOUNTAINS WILL BE OBSCURED. /FB
&&
.MARINE...UPDATED 215 AM PST SATURDAY 9 JAN 2016...A COLD FRONT WILL
MOVE THROUGH EARLY THIS MORNING. WINDS HAVE DECREASED BELOW GALE BUT
STEEP SEAS CONTINUE WITH VERY SHORT PERIOD AROUND 9 SECONDS. A
WEAKER FRONT WILL MOVE THROUGH THE WATERS MONDAY, BUT WITH ANOTHER
HEAVY LONG PERIOD WEST SWELL. A STRONG LOW PRESSURE WILL APPROACH
THE WATERS FROM THE WEST TUESDAY. SOUTH WINDS AHEAD OF THIS LOW
COULD APPROACH GALE AGAIN TUESDAY NIGHT. /FB
&&
PREV DISCUSSION... /ISSUED 302 AM PST SAT JAN 9 2016/
DISCUSSION...
SHORT TERM...TODAY THROUGH TUESDAY...A WEAK FRONT IS MOVING ONSHORE
THIS MORNING, AND IS BRINGING SOME LIGHT PRECIPITATION TO THE AREA.
SNOW LEVELS WILL REMAIN AT ABOUT 4000 FEET THROUGHOUT THE AREA, WITH
THE EXCEPTION OF THE MOUNT SHASTA CITY AREA, WHERE SNOW LEVELS WILL
BE ABOUT 500 LOWER DUE TO PRECIPITATION RATES IN THE STRONGER AREA OF
UPSLOPE FLOW. DUE TO THIS, THE WINTER WEATHER ADVISORY FOR THAT AREA
WILL REMAIN IN EFFECT UNTIL LATER THIS MORNING, MOSTLY DUE TO
WEEKEND TRAVEL CONCERNS. A FEW INCHES ARE ALSO EXPECTED IN THE
MOUNTAINS AND ACROSS THE EAST SIDE, BUT AMOUNTS SHOULD NOT APPROACH
ADVISORY CRITERIA.
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BUILD INTO THE
PACIFIC NORTHWEST LATE TONIGHT AND PERSIST THROUGH SUNDAY. LOOK FOR
VALLEY FOG OR LOW STRATUS IN THE WEST SIDE VALLEYS, AND MUCH COLDER
LOW TEMPERATURES EAST OF THE CASCADES, BOTH DUE TO MOSTLY CLEAR
SKIES AND EXCELLENT RADIATIONAL COOLING OVERNIGHT. THE NEXT SYSTEM,
DUE IN LATE SUNDAY NIGHT INTO MONDAY, APPEARS VERY SIMILAR TO THE
ONE TODAY, WEAKENING CONSIDERABLY AS IT MOVES ONSHORE, AND ONLY
PRODUCING LIGHT PRECIPITATION. THE BULK OF THE MOISTURE WITH THIS
FRONT WILL BE CONCENTRATED TO OUR SOUTH, BUT CURRY, JOSEPHINE, AND
WESTERN SISKIYOU COUNTIES SHOULD SEE SOME DECENT PRECIPITATION
AMOUNTS, ALTHOUGH NOTHING LIKE THE LARGER SYSTEMS SEEN BACK IN
DECEMBER.
RIDGING RETURNS LATE MONDAY NIGHT INTO TUESDAY MORNING, AHEAD OF THE
NEXT FRONT DUE IN TUESDAY AFTERNOON. THIS APPEARS TO BE A MORE
CLASSIC WET-SEASON FRONTAL SYSTEM, THAT SHOULD THE MODELS VERIFY,
HAS THE POTENTIAL TO BRING SIGNIFICANT RAINS AND WIND TO SOUTHERN
OREGON AND NORTHERN CALIFORNIA. HOWEVER, THERE IS SOME QUESTION IN
TIMING, AS WELL AS IF THE SYSTEM WILL HOLD TOGETHER SUFFICIENTLY AS
IT MOVES ASHORE AND ENCOUNTERS THE PERSISTENT RIDGE IN PLACE OVER
THE WESTERN US. WILL HOPE FOR BETTER CONFIDENCE IN THESE DETAILS
WITH THE NEXT ROUND OF MODEL RUNS, BUT FOR NOW HAVE TRENDED TOWARDS
A BLEND OF THE GFS AND ECMWF SOLUTIONS AS WE HEAD INTO THE EXTENDED
PERIOD. -BPN
LONG TERM DISCUSSION FROM PREVIOUS ISSUANCE...TUESDAY NIGHT
THROUGH FRIDAY...MODELS SHOW A PERSISTENT PATTERN WITH FRONTS
MOVING INTO THE AREA THROUGH NEXT WEEK. AN UPPER LOW IS FORECAST
TO REMAIN ANCHORED NEAR THE ALEUTIAN ISLANDS WITH A STRONG UPPER
LEVEL JET OVER THE CENTRAL PACIFIC WHILE WEAK RIDGING REMAINS OVER
THE PACNW. SEVERAL LOW PRESSURE SYSTEMS AND FRONTS ARE FORECAST TO
MOVE INTO THE RIDGE AND WEAKEN IT AND BRING PERIODS OF
PRECIPITATION THROUGH NEXT WEEK.
TUESDAY NIGHT INTO WEDNESDAY...MODELS ARE SHOWING GOOD AGREEMENT
WITH A FRONT PUSHING INLAND TUESDAY NIGHT. THIS FRONT IS EXPECTED TO
SPREAD MODERATE PRECIPITATION ACROSS MUCH OF THE AREA WITH SNOW
LEVELS INITIALLY AROUND 5000 FEET TUESDAY NIGHT AND LOWERING TO 4000
FEET DURING THE DAY WEDNESDAY. THE GFS SHOWS A WEAK WARM LAYER ABOVE
THE SURFACE MOVING INTO EASTERN AREAS ON TUESDAY NIGHT WITH
TEMPERATURES NEAR OR BELOW FREEZING AT THE SURFACE IN EASTERN
VALLEYS. THE ECMWF THOUGH INDICATES COLDER TEMPERATURES WITH ONLY SNOW
OVER EASTERN AREAS. IN THE CURRENT FORECAST, HAVE ADDED A SLIGHT
CHANCE FOR FREEZING RAIN TO VALLEYS EAST OF THE CASCADES TUESDAY
NIGHT. CONFIDENCE IS LOW FOR FREEZING RAIN THOUGH AND WILL NEED TO
MONITOR THIS WITH FUTURE MODEL RUNS. A SURFACE LOW IS FORECAST TO
DEVELOP ON THE SOUTHERN END THIS FRONT WITH THE SHORTWAVE TROUGH AND
MOVE INTO SOUTHERN OREGON AND/OR NORTHERN CALIFORNIA LATE WEDNESDAY.
MODELS SHOW VARIABILITY ON THE TRACK AND STRENGTH OF THIS LOW.
OVERALL EXPECT THAT THIS FEATURE ALONG WITH THE SHORTWAVE TROUGH
MOVING INLAND WILL MAY BRING SOME CONTINUED SHOWERS TO THE AREA
THROUGH WEDNESDAY NIGHT.
EXPECT DIMINISHING SHOWERS THURSDAY INTO FRIDAY WITH WEAK RIDGING
BUILDING INTO THE REGION AGAIN. OF NOTE, THE GFS CONTINUES TO SHOW
SOME WEAK DISTURBANCES MOVING INTO THE RIDGE AND BRINGING A SLIGHT
CHANCE FOR LIGHT PRECIPITATION, MAINLY FOR NORTHERN CALIFORNIA AND
FROM THE CASCADES WEST.
FRIDAY NIGHT INTO SATURDAY, MODELS THEN TREND WETTER WITH ANOTHER
FRONT BRINGING ADDITIONAL RAIN AND SNOW INTO THE AREA. THE GFS
REMAINS FASTER THAN THE ECMWF THOUGH ON THE TRACK OF THIS FRONT.
HAVE GONE WITH A BLEND OF THE MODELS FOR THE PRECIPITATION FORECAST
LATE NEXT WEEK. /CC
AVIATION...FOR THE 09/06Z TAF CYCLE...A WARM FRONT MOVING ACROSS
THE REGION THIS EVENING WILL BRING LIGHT WEST SIDE VALLEY RAIN AND
MOUNTAIN AND EAST SIDE LIGHT SNOW. EXPECT MVFR CIGS/VIS ON THE WEST
SIDE OVERNIGHT AND MVFR TO IFR CONDITIONS ON THE EAST SIDE.
MOUNTAINS WILL BE OBSCURED THROUGH THE NIGHT. CIGS AND VIS WILL
IMPROVE TO VFR SATURDAY AFTERNOON. -WRIGHT
MARINE...UPDATED 415 PM PST FRIDAY 8 JAN 2016...A COLD FRONT WILL MOVE
THROUGH TONIGHT WITH GALE FORCE SOUTH WINDS AND VERY STEEP SEAS
EXPECTED BEYOND 5NM FROM SHORE. WITH AN OFFSHORE COMPONENT TO THE WINDS
THIS EVENING, AREAS IN CLOSER TO SHORE LIKELY ONLY HAVE CONDITIONS
HAZARDOUS TO SMALL CRAFT. BUT EVEN THOSE AREAS PROBABLY HAVE VERY STEEP
SEAS FOR A WHILE SATURDAY MORNING. A WEAKER FRONT WILL MOVE THROUGH THE
WATERS MONDAY, BUT WITH ANOTHER HEAVY LONG PERIOD WEST SWELL. A STRONG
COLD FRONT WILL APPROACH THE WATERS TUESDAY NIGHT AND MOVE ONSHORE
WEDNESDAY. SPILDE
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...
CA...WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING FOR CAZ082.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST SUNDAY
FOR PZZ350-356.
HAZARDOUS SEAS WARNING UNTIL 10 AM PST THIS MORNING FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
FOR PZZ370-376.
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1143 AM CST SAT JAN 9 2016
.UPDATE...
FOR 18Z AVIATION DISCUSSION.
&&
.DISCUSSION...
A FEW LIGHT SHOWERS AND DRIZZLE ARE ONGOING ACROSS THE WESTERN
PORTIONS OF MIDDLE TN AT UPDATE TIME THIS MORNING. SHOWER COVERAGE
AND INTENSITY WILL PICK UP THROUGH THE AFTERNOON HOURS AS THE LOW
PRESSURE CENTER OF THIS CURRENT SYSTEM PULLS NEWD OUT OF NW
MISSISSIPPI/SE ARKANSAS AND TRAVERSES WEST TN. THE QUESTIONS WILL
LIE WITH HOW MUCH THUNDERSTORM COVERAGE WILL THERE BE. AS THE LOW
MOVES CLOSER...A POCKET OF DRY AIR WILL MOVE INTO THE MID-STATE.
EVIDENT ALREADY IN THE VISIBLE SATELLITE IMAGERY OVER NORTHERN
MS...SOME SUNSHINE MAY VERY WELL PEEK OUT EARLY THIS AFTERNOON.
THIS IS THE INGREDIENT NECESSARY TO WARM US UP A LITTLE AND PROVIDE
SOME LIMITED CAPE VALUES /250-500 J/KG/ OVER THE SOUTHERN HALF OF
THE MID-STATE. IF WE CAN GET ENOUGH INSTABILITY TO FIRE A FEW
THUNDERSTORMS...FORECAST SOUNDINGS SUGGEST THAT THE COLD AIR
ALOFT WILL PROVIDE MID-LEVEL LAPSE RATES SHARP ENOUGH FOR SMALL
HAIL DEVELOPMENT AND EVEN A STRONG WIND GUST OR TWO. THE LATEST
COUPLE RUNS OF THE HRRR IS IN DECENT AGREEMENT WITH THIS SOLUTION
AS IT CONTINUES TO BRING A BROKEN LINE OF THUNDERSTORMS NEWD INTO
OUR SOUTHERN COUNTIES LATE THIS AFTERNOON. WILL HIGHLIGHT THIS
STRONG THUNDERSTORM POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK
THROUGH THE EARLY EVENING HOURS. THE GOOD NEWS IS AFTER THE SUN
GOES DOWN WE`LL LOSE THE INSTABILITY AND ANY STORMS THAT HAVE
DEVELOPED SHOULD DISSIPATE LEAVING ONLY MODERATE SHOWERS FOR OUR
EASTERN COUNTIES THIS EVENING.
THE BIGGER STORY WILL BE THE PUSH OF COLD AIR BEHIND THIS SYSTEM
AND IT MATCHING UP WITH LINGERING ATMOSPHERIC MOISTURE. MODELS ARE
IN DECENT AGREEMENT ABOUT MIDDLE TN SEEING ITS FIRST SNOWFALL OF
THIS WINTER AND OF 2016. WE`RE WORKING OUT THE DETAILS OF WHAT TO
EXPECT AND THIS WILL BE THE FOCUS OF THIS AFTERNOON`S FULL
FORECAST PACKAGE.
&&
.AVIATION...
18Z TAF DISCUSSION.
DIVERSE TAF CYCLE. WILL RANGE FROM LIGHT TO MODERATE RAINS THIS
AFTERNOON AND EVENING TO A CHANGEOVER TO LIGHT SNOW AFTER 06Z AS
COLD AIR MOVES IN. MVFR CIGS ARE EXPECTED TO CONTINUE THIS
AFTERNOON AND BEGIN TO FALL INTO IFR THIS EVENING. VIS WILL
FLUCTUATE BASED ON RAIN INTENSITIES.
WINDS WILL BE BREEZY OUT OF THE SOUTHEAST THEN VEER TO THE NW AS
THE COLDER AIR INTRUDES INTO THE MID-STATE TONIGHT. GUSTS OF
15-18 KTS ARE POSSIBLE THROUGHOUT THE CYCLE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........UNGER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1110 AM CST SAT JAN 9 2016
.UPDATE...
FOR MORNING DISCUSSION.
&&
.DISCUSSION...
A FEW LIGHT SHOWERS AND DRIZZLE ARE ONGOING ACROSS THE WESTERN
PORTIONS OF MIDDLE TN AT UPDATE TIME THIS MORNING. SHOWER COVERAGE
AND INTENSITY WILL PICK UP THROUGH THE AFTERNOON HOURS AS THE LOW
PRESSURE CENTER OF THIS CURRENT SYSTEM PULLS NEWD OUT OF NW
MISSISSIPPI/SE ARKANSAS AND TRAVERSES WEST TN. THE QUESTIONS WILL
LIE WITH HOW MUCH THUNDERSTORM COVERAGE WILL THERE BE. AS THE LOW
MOVES CLOSER...A POCKET OF DRY AIR WILL MOVE INTO THE MID-STATE.
EVIDENT ALREADY IN THE VISIBLE SATELLITE IMAGERY OVER NORTHERN
MS...SOME SUNSHINE MAY VERY WELL PEEK OUT EARLY THIS AFTERNOON.
THIS IS THE INGREDIENT NECESSARY TO WARM US UP A LITTLE AND PROVIDE
SOME LIMITED CAPE VALUES /250-500 J/KG/ OVER THE SOUTHERN HALF OF
THE MID-STATE. IF WE CAN GET ENOUGH INSTABILITY TO FIRE A FEW
THUNDERSTORMS...FORECAST SOUNDINGS SUGGEST THAT THE COLD AIR
ALOFT WILL PROVIDE MID-LEVEL LAPSE RATES SHARP ENOUGH FOR SMALL
HAIL DEVELOPMENT AND EVEN A STRONG WIND GUST OR TWO. THE LATEST
COUPLE RUNS OF THE HRRR IS IN DECENT AGREEMENT WITH THIS SOLUTION
AS IT CONTINUES TO BRING A BROKEN LINE OF THUNDERSTORMS NEWD INTO
OUR SOUTHERN COUNTIES LATE THIS AFTERNOON. WILL HIGHLIGHT THIS
STRONG THUNDERSTORM POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK
THROUGH THE EARLY EVENING HOURS. THE GOOD NEWS IS AFTER THE SUN
GOES DOWN WE`LL LOSE THE INSTABILITY AND ANY STORMS THAT HAVE
DEVELOPED SHOULD DISSIPATE LEAVING ONLY MODERATE SHOWERS FOR OUR
EASTERN COUNTIES THIS EVENING.
THE BIGGER STORY WILL BE THE PUSH OF COLD AIR BEHIND THIS SYSTEM
AND IT MATCHING UP WITH LINGERING ATMOSPHERIC MOISTURE. MODELS ARE
IN DECENT AGREEMENT ABOUT MIDDLE TN SEEING ITS FIRST SNOWFALL OF
THIS WINTER AND OF 2016. WE`RE WORKING OUT THE DETAILS OF WHAT TO
EXPECT AND THIS WILL BE THE FOCUS OF THIS AFTERNOON`S FULL
FORECAST PACKAGE.
&&
.AVIATION...
12Z TAF DISCUSSION.
NUMEROUS SHOWERS ARE EXPECTED TO SPREAD IN FROM THE WEST TODAY,
BEGINNING AT CKV AND BNA AROUND 15Z, AND AT CSV AROUND 21Z. MVFR
CONDITIONS AT CKV WILL DETERIORATE TO IFR BY 18Z, THEN CONTINUE
IFR FOR THE REST OF THE FORECAST PERIOD. MVFR CONDITIONS WILL
DEVELOP AT BNA AND CSV BY 15Z, THEN DETERIORATE TO IFR BY LATE
AFTERNOON OR EVENING. A FEW THUNDERSTORMS ARE ALSO POSSIBLE TODAY,
AHEAD OF AN APPROACHING COLD FRONT. FOLLOWING PASSAGE OF THE COLD
FRONT TONIGHT, -SHRA WILL CHANGE TO -RASN AND -SN.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........UNGER
LONG TERM..................13