Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/20/15
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1256 AM EST SUN JAN 18 2015
.SYNOPSIS...
WEAK LOW PRES WILL APPROACH THE REGION SUNDAY...THEN RAPIDLY
DEEPEN OVER THE AREA SUNDAY EVENING BEFORE DEPARTING OVERNIGHT.
HIGH PRESSURE BUILDS IN MONDAY AND TUESDAY. LOW PRESSURE
APPROACHES FROM THE WEST LATE TUESDAY AND PASSES
WEDNESDAY...DEEPENING AS IT MOVES EAST. WEAK HIGH PRESSURE BUILDS
LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A SHORTWAVE WILL PIVOT EAST THROUGH THE THE OHIO VALLEY
OVERNIGHT TO THE EAST COAST BY LATE SUNDAY...SPAWNING LOW PRES
OVER THE AREA LATE SUNDAY.
CLOUD COVER WILL INCREASE OVERNIGHT AS LLJ AND WAA STRENGTHENS.
COMBINATION OF LIGHT SURFACE RETURN FLOW AROUND THE HIGH AND
INCREASING CLOUD COVER WILL CAUSE TEMPS TO SLOWLY RISE ALONG THE
COAST AND REMAIN FAIRLY STEADY ACROSS INTERIOR.
CURRENT FREEZING RAIN ADVISORY LOOKS REASONABLE FOR LOCATIONS
AWAY FROM COASTLINE AS TEMPS WILL BE SLOW TO RISE THROUGH THE 20S
WITH LIGHT FLOW. OPER MODELS AND HRRR SHOW POTENTIAL FOR
DRIZZLE/LIGHT RA TOWARDS DAYBREAK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
RAPID DEVELOPMENT OF STEADIER AND HEAVIER PRECIP THROUGH THE MID
TO LATE MORNING WITH STRONGER LIFT.
AS THE FLOW STRENGTHENS AFTER SUNRISE...TEMPS ALONG THE SRN TIER
RISE ABV FREEZING. ACROSS THE NWRN INTERIOR THE COLD AIR WILL TAKE
LONGER TO ERODE. END TIME FOR THE ADVY IS 13Z COASTS AND 16Z
INTERIOR AS A RESULT. MAIN CHALLENGE FOR THE ICE FCST IS THE
EXTENT OF THE PCPN. IF THE PCPN TAKES LONGER TO
MATERIALIZE...LITTLE TO NO ICE ALONG THE COASTS/CITY AND REDUCED
AMOUNTS ACROSS THE INTERIOR.
BUT...EVEN IF AIR TEMPS DO RISE ABOVE FREEZING...NYS THRUWAY ROAD TEMP
SENSORS INDICATING...ROAD TEMPS AROUND 30 DEGREES ACROSS SOUTHERN
WESTCHESTER AND MID 20S ACROSS NORTHERN
WESTCHESTER/ORANGE/ROCKLAND COUNTIES. THIS SHOULD BE A REASONABLE
PROXY FOR NE NJ AND SW CT ROADS AS WELL. SO UNTREATED GROUND
SURFACE ICING MAY BE AN ISSUE UNTIL TEMPS CAN GET INTO THE MID
30S...WHICH MATCHES FAIRLY WELL WITH END TIMES OF ADVISORY.
THE CWA GETS INTO THE RRQUAD OF THE 130KT H3 JET LATE IN THE DAY.
THIS WILL ALLOW FOR MODERATE TO HVY RAIN TO BLOSSOM OVER THE
AREA. ALL RAIN WITH THE INTENSIFYING SLY FLOW WARMING THE LLVLS.
HAVE BUMPED UP RAIN AMOUNTS A BIT WITH HIGH RES MODELS INDICATING
POTENTIAL FOR 1+ INCH OF RAIN IN 3 HRS...WITH 40+ DBZ ECHOES IN
SIMULATED REFLECTIVITY. MMEFS IN FAIRLY GOOD CONSENSUS OF AROUND 1
INCHES EAST AND FAR NW TRI-STATE TO 1 1/2 INCHES OF RAIN FOR
NYC/NJ METRO IN ABOUT 12 HRS. NAM/SREF INDICATING POTENTIAL FOR
ISOLD TSTM IN THE LATE AFTN/EVE...MAINLY SE CT/E LI.
COLD DRY AIR WRAPS IN FROM THE W SUN EVE AND NGT...ENDING PCPN
QUICKLY. W WINDS WILL GUST TO AROUND 25 MPH BY MON MRNG.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
INITIALLY...GLOBAL MODELS REMAIN IN GENERAL AGREEMENT EARLY IN THE
WEEK. THEN DIFFERENCES ARISE IN THE HANDLING OF QUICK MOVING...WEAK
SYSTEMS IN A PROGRESSIVE PATTERN. FORECAST DETAILS REMAIN LOW AS A
RESULT.
GENERALLY DRY THOUGH...EXCEPT POSSIBLY MID WEEK.
DRY WEATHER PREVAILS MONDAY AS DEEP LOW PRESSURE DEPARTS...AS DOES
UPPER TROUGH AS IT MOVES NORTHEASTWARD. THIS WILL BE REPLACED BY
WEAK RIDGE...SFC HIGH BRIEFLY. THE DRY WEATHER CONTINUES INTO
TUESDAY. THEN CLIPPER SYSTEM QUICKLY APPROACHES FROM THE WEST...WITH
12Z ECMWF FORECASTING UP TO TWO TENTHS OF AN INCH OF QPF...WITH
MID/UPPER LEVEL VORT PASSING NEARBY OR JUST SOUTH OF THE AREA BY
EARLY WEDNESDAY. LOOKS LIKE MAINLY A SNOW EVENT IF IT DOES INDEED
MATERIALIZE DUE TO ENOUGH COLD AIR ALOFT. POPS UPPED FROM
PREVIOUS...AND WITH COORDINATION FROM SURROUNDING OFFICES...CAPPED
POPS AT HIGH CHANCE FOR NOW. ANY SHIFT IN SUBSEQUENT MODEL RUNS WILL
MAKE A BIG DIFFERENCE...WITH EITHER CATEGORICAL POPS IN A LOW QPF
EVENT...TO A DRY FORECAST.
THEREAFTER...UPSTREAM TROUGH...WITH DIFFERENCES IN THE GLOBAL MODELS
NOTED...APPROACHES AND MOVES ACROSS THE NORTHEAST. GENERALLY DRY
ACROSS OUR AREA THOUGH.
TEMPS ARE A MET/MAV BLEND MONDAY...AND GRIDDED MOS TUESDAY.
THEREAFTER...BLENDED ECE MOS WITH WPC AND GRIDDED MOS. IN
GENERAL...NEAR NORMAL TEMPS COOL LATE IN THE WEAK AS HEIGHTS LOWER
BEHIND MID WEEK CLIPPER.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
LOW PRESSURE DEVELOPS IN THE CAROLINAS EARLY THIS MORNING AND WILL
THEN MOVE TO THE MID ATLANTIC COAST THIS AFTERNOON AND THEN OVER THE
REGION THIS EVE.
LIGHT DRIZZLE OR -SHRA EXPECTED TO SPREAD INTO THE AREA EARLY THIS
MORNING. RAIN FOR COASTAL TERMINALS...BUT FOR KEWR/KTEB/KHPN/KSWF THERE
WILL LIKELY BE ONSET AFTER 10-14Z AS -FZDZ/-FZRZ. EVEN IF SURFACE
TEMPS RISE JUST ABOVE FREEZING AT THESE TERMINALS...GROUND TEMPS
COULD BE AROUND FREEZING FOR A COUPLE MORE HOURS RESULTING
IN THE CONTINUATION OF ICING ON UNTREATED SURFACES. PRECIP SHOULD
CHANGE TO RAIN AT MOST TERMINALS BY 13-14Z WITH GROUND TEMPS
WARMING ABOVE FREEZING...BUT HOLDING OFF UNTIL AT LEAST 15-16Z AT
KSWF.
FLIGHT CAT SHOULD QUICKLY GO TO LOW-END MVFR WITH ONSET OF PRECIP
AROUND DAYBREAK...AND THEN TO IFR A COUPLE OF HRS
LATER CONTINUING THROUGH AFTERNOON IN MODERATE TO HEAVY RAIN.
POTENTIAL FOR LIFR OR LOWER CONDS AT KTEB/KHPN/KSWF LATE MORNING
THROUGH THE AFTERNOON WITH LIGHT WINDS AND RAIN. THERE IS A LOW
POTENTIAL FOR SPARSE TSRA AT KISP/KGON LATE THIS AFT/EARLY EVE.
GENERALLY S FLOW 10 KT OR LESS EXPECTED TONIGHT. MEANWHILE...SE
WINDS INCREASE TO AROUND 15 KT WITH OCCASIONAL GUSTS INTO THE
LOWER 20S FOR KJFK AND EASTERN TERMINALS THIS MORNING/AFTN.
POTENTIAL FOR GUSTS OF 30+KT IN HEAVIER RAIN. LLWS POTENTIAL
BETWEEN 18Z TO 00Z FOR COASTAL TERMINALS...WITH 45-50 KT LLJ AT 2
KFT.
WINDS SHIFT TO WEST AFTER COLD FRONTAL PASSAGE BETWEEN 23Z TO 04Z.
.OUTLOOK FOR 06Z MONDAY THROUGH THU...
.LATE TONIGHT...GUSTY WNW WINDS. CONDS GRADUALLY IMPROVING TO
MVFR THEN VFR. A FEW SNOW SHOWERS/FLURRIES POSSIBLE AT KSWF.
.MON...VFR. WEST WINDS 10-20 KT WITH G20-30 KT.
.TUE...VFR.
.WED...MVFR OR LOWER CONDS POSSIBLE IN SNOW.
.WED NIGHT...VFR.
.THU...VFR. NW WINDS G15-20KT.
&&
.MARINE...
SOUTHERLY WINDS WILL BUILD SEAS ON THE OCEAN TONIGHT. WINDS SHOULD
INCREASE TO AROUND 25 KTS AFTER MIDNIGHT AS COLD AIR ALOFT ALLOWS
MIXING OF STRENGTHENING LOW LEVEL JET. AS THE AIR WARMS
ALOFT...WINDS MAY ABATE SOMEWHAT LATE TONIGHT INTO EARLY SUNDAY
MORNING.
WAVES REACH 5 FT ON SUNDAY. A SCA ISSUED FOR THE OCEAN THRU SUN
NGT. WINDS WILL GUST UP TO 25-30KT WITH THE HIGHEST GUSTS NEAR
44017. ELSEWHERE...WINDS GENERALLY BLW 25 KT...BUT EASTERN LI
SOUND AND BAY MAY BRIEFLY SEE MARGINAL SCA LATE SUN/SUN EVE.
AS DEEP LOW PRESSURE TRACKS ACROSS THE CANADIAN MARITIMES
MONDAY...GUSTY NW/W FLOW PREVAILS ON THE WATERS. ROUGH CONDITIONS
ARE EXPECTED.
WINDS WILL GRADUALLY DIMINISH TUESDAY AHEAD OF CLIPPER LOW.
THIS LOW MOVES IN THE VICINITY OF THE WATERS WEDNESDAY...THEN
DEEPENS WELL TO THE EAST WEDNESDAY NIGHT INTO THURSDAY. WEAK HIGH
PRESSURE BUILDS BEHIND IT.
AS FOR POTENTIAL HAZARDS...SCA CONDITIONS ARE LIKELY MONDAY INTO
MONDAY NIGHT. SUB SCA CONDITIONS SHOULD PREVAIL THROUGH MID WEEK
INTO THE LATE WEEK PERIOD.
WAVE WATCH III OUTPUT SEEMS REASONABLE.
&&
.HYDROLOGY...
POTENTIAL FOR 1 TO 1 1/2 INCHES OF RAIN ACROSS THE AREAS...WITH
LOCALLY HIGHER AMOUNTS. HEAVIEST RAIN MAY BE ACROSS NYC/NJ METRO
CORRIDOR...WITH LIGHTER AMOUNT NW AND EAST. POTENTIAL FOR ABOUT 1 INCH
OF RAIN IN 3 HRS IN AFT/EARLY EVE.
THESE RAINFALL RATES/AMOUNTS WOULD CAUSE MINOR URBAN/POOR
DRAINAGE FLOODING DURING THE AFT/EVE. ADDITIONALLY...IF THE
HEAVIER RAINFALL AMOUNTS ARE REALIZED ACROSS NE NJ/LOWER HUDSON
VALLEY/SW CT...THERE WILL BE POTENTIAL FOR MINOR FLOODING OF
FLASHY SMALL STREAMS DUE TO SLOWLY THAWING GROUND AND RUNOFF.
ICE ON THE WALLKILL AND YANTIC RIVERS IS CAUSING MINOR
FLUCTUATIONS IN RIVER LEVELS AT THIS TIME.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR CTZ005-
006.
FREEZING RAIN ADVISORY UNTIL 8 AM EST THIS MORNING FOR CTZ009-
010.
NY...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR
NYZ067>070.
FREEZING RAIN ADVISORY UNTIL 8 AM EST THIS MORNING FOR
NYZ071>074.
NJ...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR NJZ002-
004-103.
FREEZING RAIN ADVISORY UNTIL 8 AM EST THIS MORNING FOR NJZ006-
104>108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST MONDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JMC/PW
NEAR TERM...JMC/NV/PW
SHORT TERM...JMC
LONG TERM...PW
AVIATION...NV
MARINE...JMC/PW
HYDROLOGY...JMC/PW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
222 AM CST SUN JAN 18 2015
.SHORT TERM...
259 PM CST
THROUGH MONDAY...
AFTER MILD TEMPERATURES TODAY...A FRONTAL PASSAGE THIS EVENING WILL
BRING A CHANCE OF LIGHT RAIN AND THEN POSSIBLE FLURRIES
OVERNIGHT...BUT NOT MUCH OF A TEMPERATURE CHANGE FOR TOMORROW. THE
PARENT LOW STAYS WELL NORTH OF THE LAKES...AND LOOKING UPSTREAM
SHOWS UPPER 30S TO LOWER 40S ACROSS PARTS OF MINNESOTA AND ALL THE
WAY INTO NORTH DAKOTA. THIS IS A FAIRLY GENTLE POST FRONTAL
AIR MASS FOR THIS TIME OF YEAR.
LATE THIS AFTERNOON THE RADAR MOSAIC IS SHOWING SOME MOSTLY ELEVATED
SHOWERS ACROSS SOUTHERN WISCONSIN AND NORTHWEST ILLINOIS...BUT SFC
OBSERVATIONS ARE SHOWING VERY LITTLE REACHING THE GROUND BELOW CLOUD
BASES OF 5000 FT OR MORE. WITH THE BEST MOISTURE ALOFT AND THE BEST
SHORTWAVE ENERGY TRAILING THE SFC FRONT...MID TO LOWER LEVELS SLOWLY
SATURATE BUT THEN HIGHER LEVELS START TO DRY OUT. MODELS ALSO ARE
SHOWING DECENT FGEN AND INSTABILITY ALONG THE FRONT BUT THE AIR IN
THAT REGION IS NOT FAVORABLY COLD OR SATURATED ENOUGH FOR
SUBSTANTIAL SNOW GROWTH. FINALLY...LAKE EFFECTS IN NW INDIANA ALSO
ARE LIMITED BY RELATIVELY MILD AIR AND MORE WESTERLY THAN NORTH OR
NORTHWESTERLY FLOW. IN SUMMARY...EXPECT THE ISOLATED LIGHT SHOWERS
TO PERSIST THIS EVENING AND POSSIBLY TRANSITION TO LIGHT SNOW OR
FLURRIES LATE WITH DIURNAL COOLING.
COLDER AIR MIGHT BE EXPECTED SUNDAY WITH NORTHWEST FLOW BEHIND THE
COLD FRONT...BUT AS MENTIONED ABOVE THE UPSTREAM AIR MASS IS NEARLY
AS WARM AS WHAT WE ARE SEEING WITH TODAYS TEMPERATURES. FOR THAT
REASON...WILL ONLY DROP FCST HIGH TEMPERATURES INTO THE UPPER
30S...AND WOULD NOT BE SURPRISED TO SEE SOME PLACES IN THE
SOUTHWEST PORTION OF OUR AREA REACH 40 AGAIN WITH CLEARER SKIES
AND LESS SNOW COVER.
MONDAY SHOULD REMAIN RELATIVELY MILD...LIKE TODAY PERHAPS A COUPLE
DEGREES WARMER THAN SUNDAY...AS WINDS TURN SOUTH AHEAD OF THE NEXT
LOW PRESSURE SYSTEM APPROACHING FROM THE NORTHWEST.
LENNING
&&
.LONG TERM...
259 PM CST
MONDAY NIGHT THROUGH SATURDAY...
DETERMINISTIC MODELS DISAGREE ON THE EXACT PATH OF THE NEXT LOW
PRESSURE SYSTEM MONDAY NIGHT INTO TUESDAY...BUT GENERALLY AGREE ON
BRINGING IT VERY CLOSE TO THE LOCAL AREA. THIS SYSTEM APPEARS TO
HAVE A DEEPER AND MORE ENERGETIC SHORTWAVE ALOFT...AND SOME MODELS
ARE HINTING AT MESOSCALE SUPPORT ALTHOUGH IT IS TOO EARLY TO
NARROW DOWN THE EXTENT AND AMOUNTS OF ANY SNOW THAT MIGHT DEVELOP.
WITH ENOUGH COLD AIR...SOME AREAS COULD SEE LIGHT ACCUMULATIONS OF
A FEW TENTHS EVEN WITHOUT ASSISTANCE FROM MESOSCALE FORCING. THE
TRACK OF THE LOW ALSO RAISES THE IDEA OF PTYPE CONCERNS MONDAY
NIGHT INTO TUESDAY.
AFTER ONE LAST SEASONABLY MILD DAY TUESDAY...OR AT LEAST EARLY
TUESDAY...MORE AMPLIFIED RIDGING OUT WEST AND A DEEPENING TOUGH OVER
THE EASTERN CONUS WILL SUPPORT THE ARRIVAL OF A COLDER AIR MASS LATE
TUESDAY WITH THE WEEKS COLDEST AIR SETTLING IN WEDNESDAY AND HANGING
AROUND AT LEAST INTO FRIDAY. SECONDARY COLD FRONTS AND WEAK UPPER
WAVES WILL SUPPORT ONGOING CHANCES OF LIGHT SNOW THROUGH THE WEEK.
LOOKING FARTHER AHEAD...MILDER AIR MAY ARRIVE AGAIN FRIDAY OR LATE
FRIDAY INTO EARLY SATURDAY AHEAD OF A BROADER AND DEEPER LOW
PRESSURE SYSTEM WORKING INTO THE GREAT LAKES NEXT WEEKEND.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR CIGS OF 2000-3000 FT INTO SUNDAY MORNING.
//DISCUSSION...UPDATED 06Z...
AS LOW PRESSURE OVER THE NORTHERN GREAT LAKES MOVES
EAST THROUGH SUNDAY MORNING...CYCLONIC FLOW WILL CONTINUE TO DRIVE
WEST WINDS WITH FREQUENT GUSTS AROUND 20 KT. THE PATTERN IS ALSO
SUPPORTIVE OF MAINLY BROKEN MVFR STRATOCU ALTHOUGH SOME TEMPORARY
SCATTERING APPEARS LIKELY AROUND DAYBREAK BASED ON UPSTREAM
SATELLITE IMAGERY. CONFIDENCE IS HIGH THAT CIGS WILL BE 2000 FT OR
HIGHER. BY AFTERNOON...VFR CONDITIONS SHOULD PREVAIL AS WEAK
SURFACE RIDGING APPROACHES.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN VFR CONDITIONS BY SUNDAY AFTERNOON.
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR PROBABLE.
TUESDAY...MVFR LIKELY/CHANCE OF IFR. CHANCE OF LIGHT SNOW/FLURRIES.
WEDNESDAY THROUGH FRIDAY...MVFR CIGS POSSIBLE. PRIMARILY DRY.
MTF/IZZI
&&
.MARINE...
220 AM CST
STRONG LOW PRESSURE ACROSS THE FAR NORTHERN LAKES WILL BE DEPARTING
THE REGION TODAY BUT ITS INFLUENCE WILL LINGER INTO TONIGHT WITH
GRADUALLY DIMINISHING BUT STILL PRONOUNCED AND GUSTY WEST TO
NORTHWEST WINDS. IN THE ILLINOIS AND INDIANA NEARSHORE AREAS THE
SPEEDS IS FORECAST TO EASE UNDER SMALL CRAFT ADVISORY CRITERIA
LATER THIS MORNING. ICE COVERAGE SHOULD BE PRETTY LIMITED WITH THE
RECENT MILD FLOW...BUT WITH THE MAINLY OFFSHORE OR PARALLEL WINDS
THE WAVES ARE NOT EXPECTED TO BE TOO MUCH OF AN ISSUE IN THESE
NEARSHORE AREAS. A PROGRESSIVE NORTHWEST FLOW PATTERN WILL BE SEEN
THE REMAINDER OF THE WEEK WITH LOW PRESSURE DROPPING FROM SOUTHERN
CANADA AND THE UPPER MIDWEST TO JUST SOUTH OF THE GREAT LAKES
REGION...WITH THE FIRST LOW BEING LATE MONDAY NIGHT INTO TUESDAY.
A WAYS OUT THERE YET...BUT IN THE DAYS 6-9 PERIOD /JANUARY 24-27/
THERE LOOKS LIKE THERE COULD BE ONE OR TWO POTENTIALLY STRONGER
STORMS IN THE REGION AS THE JET STREAM IS FORECAST TO BUCKLE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 AM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1144 PM CST Sat Jan 17 2015
.UPDATE...
ISSUED AT 855 PM CST SAT JAN 17 2015
Some sprinkles have been reaching the ground with the radar
echoes over east-central and southeast Illinois this evening, but
they should be exiting the area shortly along with the surface
cold front. A second, smaller, area of sprinkles and/or flurries
is approaching the area from eastern Iowa, associated with main
500 MB trof/vort max. This feature will track across the forecast
area over the next few hours, exiting the area to the east before
daybreak. Skies should also begin to rapidly clear behind the
second area of light precipitation.
Going forecast was in good shape overall. Updated forecast for the
latest trends, mainly to freshen the overnight precipitation and
cloud trends.
&&
.SHORT TERM...(Tonight)
ISSUED AT 245 PM CST SAT JAN 17 2015
20z/2 PM surface map shows deepening 991 mb low pressure nw of Lake
Superior with its cold front extending southward across western WI
to near the IA/IL border into central MO. This front will sweep
eastward across central and eastern IL during this evening, shifting
breezy ssw winds 15-25 mph and gusts 25-35 mph to the WNW with its
passage and diminishing to 10-20 mph tonight. A fairly strong upper
level trof over western MN to the NE/IA border to push eastward into
IL by 06Z/midnight tonight and to the IN/OH border by sunrise
Sunday. Already increased clouds this afternoon and tonight as cloud
levels lower tonight. But still think light measurable mixed
precipitation will be mainly east and ne of IL over Indiana and the
Great Lakes region since moisture limited over central IL. So
continued with chance of flurries and sprinkles over central IL this
evening and ending chances from west to east during overnight as
short wave trof axis passes to the east. Lows mostly in the lower
30s tonight with upper 20s near Galesburg and mid 30s near the
Wabash river by Lawrenceville.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 245 PM CST SAT JAN 17 2015
The upper air pattern across the lower 48 will continue to keep
the very cold air locked up over northern Canada with a more active
southern stream shunting the more significant precipitation well
to our south during this period. Several disturbances embedded in
the west to northwest flow pattern will track mainly to our north
during this period keeping us mild into early next week with little
in the way of significant rain or snow expected with these fast
moving shortwaves.
The upper trof and attendant frontal boundary that pushed across our
area today will be well off to our east by Sunday morning. Forecast
soundings showing quite a bit of low level moisture in place into
early Sunday morning with drier air filtering in from the west and
northwest during the day. Satellite data and upstream surface
observations showing a small band of lower clouds tracking southeast
behind the cool front but the HRRR model has been consistently showing
the back-edge of those clouds pushing into west central Illinois just
after midnight tonight, so with our low level flowing becoming less
cyclonic during the day Sunday, will decrease the cloud cover from
west to east in the morning. Not a lot of cold air available behind
the system late tonight into Sunday so temps will be above normal
again Sunday afternoon, although not quite as mild as this afternoon.
The next shortwave forecast to dig into the lower Great Lakes on
Tuesday with low chance PoPs confined to the north starting later
Monday night and holding into Tuesday evening across the east. Once
again, not a major rain or snow system with very little moisture
available to the upper wave. After that, a series of fast moving
shortwaves will track east southeast into the lower Great Lakes with
the surface lows moving mainly to our north. By Thursday, we see some
disagreement with the models in the speed and strength of the approaching
shortwave with the GFS much more aggressive with the upper wave and
further south track on the surface low than the current ECMWF. For now,
will side more with the weaker ECMWF which would lead to a further track
to the north later in the week, which would once again keep any low
chance PoPs confined to the north.
Towards the end of this forecast period models are starting to show
some ridging building northward around 140 degrees Longitude with
500 mb heights starting to lower over the central U.S. which would
lead to some colder temps for the last week of January. Will see
if the medium and long range models hold on to this idea in the next
several days. In the mean time, we should see a return to more seasonably
cold weather starting on Wednesday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1136 PM CST SAT JAN 17 2015
Predominantly VFR conditions expected across the central Illinois
terminals through the 06Z TAF valid time. However, a patch of MVFR
CIGS is currently crossing west-central Illinois, and this may
impact a few of the local terminals over the next few hours. A few
sprinkles and/or flurries may also accompany these lower clouds.
After the patch of lower clouds moves through, skies should
rapidly clear, with minimal cloud cover expected for the rest of
the period. Westerly winds will persist through the daytime hours
Sunday, with a gradual decrease in wind speed anticipated. Winds
will become light by Sunday night.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Bak
SHORT TERM...07
LONG TERM...Smith
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1230 PM EST SUN JAN 18 2015
.SYNOPSIS...
ISSUED AT 644 AM EST SUN JAN 18 2015
A BRIEF PERIOD OF LIGHT RAIN...MIXING WITH AND THEN CHANGING TO
LIGHT SNOW IS EXPECTED THIS MORNING. LITTLE IF ANY SNOW
ACCUMULATION IS ANTICIPATED. TEMPERATURES WILL BE NOTICEABLY
COLDER THAN YESTERDAY WITH HIGHS TODAY ONLY INTO THE MID 30S. IT
WILL BE DRY TONIGHT...EXCEPT FOR A CHANCE OF A FEW FLURRIES OFF
LAKE MICHIGAN. TEMPERATURES WILL DIP INTO THE MID 20S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM EST SUN JAN 18 2015
DISJOINTED SYSTEM MOVG THROUGH SRN GRTLKS THIS AM WITH WEAK
PREFRONTAL ZONE PUSHING THROUGH OHIO ATTM WITH LOW LEVEL
CONVERGENCE AND PARALLEL ISENTROPIC FLOW LENDING TO MEAGER LIFT
WITHIN THIN BREADTH OF RICHEST BULK MOISTURE. CWA NOW WITHIN DRY
SLOTTING/STRONG 1000-850MB MOISTURE FLUX DIVERGENCE WITH I280K
DOWNSLOPE DESPITE STRONG 160-180M/12 HR HFC MOVG THROUGH CNTL/SRN
IN AND LARGELY IN VOID OF RAFL SAVE FOR FAR NWRN/FAR SERN EDGES.
GIVEN SIG DOWNTURN IN BULK MOISTURE WITH ONLY LITTLE ENHANCEMENT
IN UPSTREAM COMMAHEAD PER WV IMAGERY AND FINE LINE LIGHT PRECIP
BAND WITH MARKED DPCVA HAVE CONTD WITH LOWER END CHC/SLIGHT CHC
POPS HIGHLIGHTING LIGHT NATURE OF PRECIP. SLIGHT INCREASE IN
HEIGHT/SLOWER COLLAPSE OF RUC WET BULB ZERO HEIGHTS WITH WARM SFC
BASED BLYR STILL LEADING TO LIQUID PTYPE ACRS NERN IL. SLIGHT LK
ENVIRONMENT CONDITIONING ACRS FAR NWRN CWA FOR HIEST POPS BYND
PREFIRST PD. EXTENSIVE CLOUD COVER AND PERSISTENT 295MB CAA TO
KEEP DIURNAL RISES WELL IN CHECK...ONLY ABOUT 3 DEGREE RISE OVR
12-15 UTC LOWS. SMALL AMPLITUDE RIDGING THIS AFTN/OVERNIGHT AS
TROF AXIS CONTS TO ROTATE THROUGH LWR GRTLKS INTO NEW ENGLAND.
POSSIBLE WEAK SHORTWAVE EJECTION OFF LEE NORTHERN ROCKIES WITH
WEAK SFC REFLECTION INTO SERN MO BY DAYBREAK MONDAY PER WELL
CLUSTERED MODEL CONSENSUS. HOWEVER THIS PRESENTS NO SENSIBLE
WEATHER CONCERNS TONIGHT GIVEN FEATURES DISTAL NATURE/DEEP LAYER
DESCENT OWING TO RISING 80-100M/12 HR 5H RISES AND DEARTH OF
MOISTURE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 425 AM EST SUN JAN 18 2015
SEASONABLE TEMPS WITH LOW/PERIODIC CHANCES FOR LIGHT PCPN
HIGHLIGHT THIS PERIOD AS SEVERAL NORTHERN STREAM SHORTWAVES IN
AMPLIFYING MEAN WNW FLOW DIG SE THROUGH THE LAKES/OH VALLEY.
CONSENSUS TREND IN 00Z GUIDANCE WAS TOWARD A DRIER SYSTEM LOCALLY
TUESDAY-TUESDAY NIGHT WITH INITIAL LEAD PV PUSH/850-700 MB FGEN
SIGNAL NORTH INTO CENTRAL MI TUESDAY...AND DEEPER LIFT/MOISTURE
CONVERGENCE TIED TO A MORE PRONOUNCED/DIGGING SHORTWAVE FOCUSING
SE OF THE AREA BY WEDNESDAY MORNING. AS A RESULT LOWERED POPS FOR
LGT RN/SN MIX IN LINE WITH NEIGHBORING OFFICES. ONLY MINOR TWEAKS
WEDNESDAY AND BEYOND AS WEAK CLIPPER SYSTEMS FOLLOW IN QUICK
SUCCESSION MAKING IT HARD TO COMPLETELY RULE OUT CHANCES FOR -SN
IN ANY PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1230 PM EST SUN JAN 18 2015
A MIDLEVEL SHORTWAVE IS CURRENTLY MOVING OVER THE AREA AND
GENERATING SOME LIGHT RAIN/SNOW AND FUEL ALTERNATE CONDITIONS.
THIS WAVE WILL EXIT IN THE NEXT TWO HOURS BUT A SECONDARY IMPULSE
WILL ROTATE THROUGH THE REGION LATER TONIGHT. PERIODS OF VFR
CONDITIONS WILL BE POSSIBLE IN BETWEEN THESE SYSTEMS BUT
CONFIDENCE IS NOT HIGH AND PREFER TO KEEP 3 KFT CEILINGS BASED ON
MODEL GUIDANCE AND UPSTREAM OBS. LOWER STRATUS WILL RETURN AGAIN
LATER TONIGHT BUT WILL CONTINUE TO HOLD JUST ABOVE FUEL ALTERNATE
CRITERIA FOR NOW. GRADUAL IMPROVEMENT EXPECTED TOMORROW BUT MAY BE
MIDDAY BEFORE VFR CONDITIONS ARRIVE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...STEINWEDEL
AVIATION...AGD
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
652 AM EST SUN JAN 18 2015
.SYNOPSIS...
ISSUED AT 644 AM EST SUN JAN 18 2015
A BRIEF PERIOD OF LIGHT RAIN...MIXING WITH AND THEN CHANGING TO
LIGHT SNOW IS EXPECTED THIS MORNING. LITTLE IF ANY SNOW
ACCUMULATION IS ANTICIPATED. TEMPERATURES WILL BE NOTICEABLY
COLDER THAN YESTERDAY WITH HIGHS TODAY ONLY INTO THE MID 30S. IT
WILL BE DRY TONIGHT...EXCEPT FOR A CHANCE OF A FEW FLURRIES OFF
LAKE MICHIGAN. TEMPERATURES WILL DIP INTO THE MID 20S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM EST SUN JAN 18 2015
DISJOINTED SYSTEM MOVG THROUGH SRN GRTLKS THIS AM WITH WEAK
PREFRONTAL ZONE PUSHING THROUGH OHIO ATTM WITH LOW LEVEL
CONVERGENCE AND PARALLEL ISENTROPIC FLOW LENDING TO MEAGER LIFT
WITHIN THIN BREADTH OF RICHEST BULK MOISTURE. CWA NOW WITHIN DRY
SLOTTING/STRONG 1000-850MB MOISTURE FLUX DIVERGENCE WITH I280K
DOWNSLOPE DESPITE STRONG 160-180M/12 HR HFC MOVG THROUGH CNTL/SRN
IN AND LARGELY IN VOID OF RAFL SAVE FOR FAR NWRN/FAR SERN EDGES.
GIVEN SIG DOWNTURN IN BULK MOISTURE WITH ONLY LITTLE ENHANCEMENT
IN UPSTREAM COMMAHEAD PER WV IMAGERY AND FINE LINE LIGHT PRECIP
BAND WITH MARKED DPCVA HAVE CONTD WITH LOWER END CHC/SLIGHT CHC
POPS HIGHLIGHTING LIGHT NATURE OF PRECIP. SLIGHT INCREASE IN
HEIGHT/SLOWER COLLAPSE OF RUC WET BULB ZERO HEIGHTS WITH WARM SFC
BASED BLYR STILL LEADING TO LIQUID PTYPE ACRS NERN IL. SLIGHT LK
ENVIRONMENT CONDITIONING ACRS FAR NWRN CWA FOR HIEST POPS BYND
PREFIRST PD. EXTENSIVE CLOUD COVER AND PERSISTENT 295MB CAA TO
KEEP DIURNAL RISES WELL IN CHECK...ONLY ABOUT 3 DEGREE RISE OVR
12-15 UTC LOWS. SMALL AMPLITUDE RIDGING THIS AFTN/OVERNIGHT AS
TROF AXIS CONTS TO ROTATE THROUGH LWR GRTLKS INTO NEW ENGLAND.
POSSIBLE WEAK SHORTWAVE EJECTION OFF LEE NORTHERN ROCKIES WITH
WEAK SFC REFLECTION INTO SERN MO BY DAYBREAK MONDAY PER WELL
CLUSTERED MODEL CONSENSUS. HOWEVER THIS PRESENTS NO SENSIBLE
WEATHER CONCERNS TONIGHT GIVEN FEATURES DISTAL NATURE/DEEP LAYER
DESCENT OWING TO RISING 80-100M/12 HR 5H RISES AND DEARTH OF
MOISTURE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 425 AM EST SUN JAN 18 2015
SEASONABLE TEMPS WITH LOW/PERIODIC CHANCES FOR LIGHT PCPN
HIGHLIGHT THIS PERIOD AS SEVERAL NORTHERN STREAM SHORTWAVES IN
AMPLIFYING MEAN WNW FLOW DIG SE THROUGH THE LAKES/OH VALLEY.
CONSENSUS TREND IN 00Z GUIDANCE WAS TOWARD A DRIER SYSTEM LOCALLY
TUESDAY-TUESDAY NIGHT WITH INITIAL LEAD PV PUSH/850-700 MB FGEN
SIGNAL NORTH INTO CENTRAL MI TUESDAY...AND DEEPER LIFT/MOISTURE
CONVERGENCE TIED TO A MORE PRONOUNCED/DIGGING SHORTWAVE FOCUSING
SE OF THE AREA BY WEDNESDAY MORNING. AS A RESULT LOWERED POPS FOR
LGT RN/SN MIX IN LINE WITH NEIGHBORING OFFICES. ONLY MINOR TWEAKS
WEDNESDAY AND BEYOND AS WEAK CLIPPER SYSTEMS FOLLOW IN QUICK
SUCCESSION MAKING IT HARD TO COMPLETELY RULE OUT CHANCES FOR -SN
IN ANY PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 637 AM EST SUN JAN 18 2015
ONLY ANTICIPATE BRIEF PD OF HIGH END IFR CIGS AT KFWA WITH PASSAGE
OF SECONDARY TROF MOVG EWD THROUGH NRN/NERN IN ATTM. THIS IN LINE
WITH UPSTREAM OB TRENDS SEEN AT KSBN KRCR KASW. CYCLONIC FLOW WITH
SUFFICIENT MOISTURE AND 925-8H COLD POOL UPSTREAM...SHOULD SUPPORT
WIDESPREAD STRATOCU THROUGH MUCH OF FCST PD. ATTEMPT TO BRING MORE
OPTIMISM WITH FCSTS OUT OF FUELING/ALTERNATE CRITERIA BY LATE
AFTERNOON...THOUGH CERTAINTY A QUESTION GIVEN MORE PESSIMISTIC
GUIDANCE/BUFKIT NAM/RAP SOUNDINGS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...STEINWEDEL
AVIATION...MURPHY
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
429 AM EST SUN JAN 18 2015
.SYNOPSIS...
ISSUED AT 425 AM EST SUN JAN 18 2015
A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE THIS MORNING...WHICH MAY
MIX WITH AND CHANCE TO LIGHT SNOW BY LATE MORNING INTO MIDDAY.
LITTLE IF ANY SNOW ACCUMULATION IS ANTICIPATED. TEMPERATURES WILL
BE NOTICEABLY COLDER THAN YESTERDAY WITH HIGHS TODAY ONLY WARM
INTO THE MID 30S. IT WILL BE DRY TONIGHT... EXCEPT FOR A FEW
FLURRIES OF LAKE MICHIGAN. TEMPERATURES WILL DIP INTO THE MID
20S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM EST SUN JAN 18 2015
DISJOINTED SYSTEM MOVG THROUGH SRN GRTLKS THIS AM WITH WEAK
PREFRONTAL ZONE PUSHING THROUGH OHIO ATTM WITH LOW LEVEL
CONVERGENCE AND PARALLEL ISENTROPIC FLOW LENDING TO MEAGER LIFT
WITHIN THIN BREADTH OF RICHEST BULK MOISTURE. CWA NOW WITHIN DRY
SLOTTING/STRONG 1000-850MB MOISTURE FLUX DIVERGENCE WITH I280K
DOWNSLOPE DESPITE STRONG 160-180M/12 HR HFC MOVG THROUGH CNTL/SRN
IN AND LARGELY IN VOID OF RAFL SAVE FOR FAR NWRN/FAR SERN EDGES.
GIVEN SIG DOWNTURN IN BULK MOISTURE WITH ONLY LITTLE ENHANCEMENT
IN UPSTREAM COMMAHEAD PER WV IMAGERY AND FINE LINE LIGHT PRECIP
BAND WITH MARKED DPCVA HAVE CONTD WITH LOWER END CHC/SLIGHT CHC
POPS HIGHLIGHTING LIGHT NATURE OF PRECIP. SLIGHT INCREASE IN
HEIGHT/SLOWER COLLAPSE OF RUC WET BULB ZERO HEIGHTS WITH WARM SFC
BASED BLYR STILL LEADING TO LIQUID PTYPE ACRS NERN IL. SLIGHT LK
ENVIRONMENT CONDITIONING ACRS FAR NWRN CWA FOR HIEST POPS BYND
PREFIRST PD. EXTENSIVE CLOUD COVER AND PERSISTENT 295MB CAA TO
KEEP DIURNAL RISES WELL IN CHECK...ONLY ABOUT 3 DEGREE RISE OVR
12-15 UTC LOWS. SMALL AMPLITUDE RIDGING THIS AFTN/OVERNIGHT AS
TROF AXIS CONTS TO ROTATE THROUGH LWR GRTLKS INTO NEW ENGLAND.
POSSIBLE WEAK SHORTWAVE EJECTION OFF LEE NORTHERN ROCKIES WITH
WEAK SFC REFLECTION INTO SERN MO BY DAYBREAK MONDAY PER WELL
CLUSTERED MODEL CONSENSUS. HOWEVER THIS PRESENTS NO SENSIBLE
WEATHER CONCERNS TONIGHT GIVEN FEATURES DISTAL NATURE/DEEP LAYER
DESCENT OWING TO RISING 80-100M/12 HR 5H RISES AND DEARTH OF
MOISTURE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 425 AM EST SUN JAN 18 2015
SEASONABLE TEMPS WITH LOW/PERIODIC CHANCES FOR LIGHT PCPN
HIGHLIGHT THIS PERIOD AS SEVERAL NORTHERN STREAM SHORTWAVES IN
AMPLIFYING MEAN WNW FLOW DIG SE THROUGH THE LAKES/OH VALLEY.
CONSENSUS TREND IN 00Z GUIDANCE WAS TOWARD A DRIER SYSTEM LOCALLY
TUESDAY-TUESDAY NIGHT WITH INITIAL LEAD PV PUSH/850-700 MB FGEN
SIGNAL NORTH INTO CENTRAL MI TUESDAY...AND DEEPER LIFT/MOISTURE
CONVERGENCE TIED TO A MORE PRONOUNCED/DIGGING SHORTWAVE FOCUSING
SE OF THE AREA BY WEDNESDAY MORNING. AS A RESULT LOWERED POPS FOR
LGT RN/SN MIX IN LINE WITH NEIGHBORING OFFICES. ONLY MINOR TWEAKS
WEDNESDAY AND BEYOND AS WEAK CLIPPER SYSTEMS FOLLOW IN QUICK
SUCCESSION MAKING IT HARD TO COMPLETELY RULE OUT CHANCES FOR -SN
IN ANY PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1242 AM EST SUN JAN 18 2015
MINIMAL CHANGES FROM EARLIER TAF AMDS AROUND 04 UTC THAT IMPROVED
CONDS/FORECAST. LAGGED LOW LEVEL MOISTURE/LOWER CONDENSATION
LEVELS REMAIN UPSTREAM AND WILL LIKELY BE A FEW MORE HOURS TO
REALIZE FUELING/ALTERNATE CRITERIA. ONLY LIGHT PRECIP WITH A
MARKED DISJOINT BTWN DYNAMICS/MOISTURE PROFILES. AS WITH PRIOR
UPDATE HAVE DISBANDED WITH SIG LWR/IFR CONDS WITH TREND TOWARD
LESSER CERTAINTY OF OCCURRENCE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...STEINWEDEL
AVIATION...MURPHY
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 INDIANAPOLIS IN
250 AM EST SUN JAN 18 2015
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST SAT JAN 17 2015
A COLD FRONT WILL BRING THE CHANCE FOR LIGHT PRECIPITATION TONIGHT
ALONG WITH A RETURN TO COOLER WEATHER SUNDAY. AFTER A BRIEF WARMUP
MONDAY...ANOTHER WEAK SYSTEM WILL BRING LOW CHANCES FOR LIGHT RAIN
AND SNOW TUESDAY AND TUESDAY NIGHT. YET ANOTHER UPPER WAVE MAY BRING
SOME LIGHT SNOW THURSDAY NIGHT AND FRIDAY. SEASONABLE TEMPERATURES
ARE EXPECTED FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 955 PM EST SAT JAN 17 2015
.UPDATE...BAND OF SHOWERS HAVE DEVELOPED OVER NORTHWEST INDIANA AND
EAST CENTRAL ILLINOIS AND THESE SHOULD SPREAD INTO OUR REGION OVER
THE NEXT FEW HOURS. ALL IN ALL THE CURRENT FORECAST IS ON TRACK.
ONLY MINOR CHANGES MADE...MAINLY TO DELAY THE CHANGE OVER TO MIXED
PRECIPITATION AN HOUR OR TWO GIVEN THAT TEMPERATURES ARE STILL WELL
ABOVE FREEZING. STILL LOOKS LIKE LOW TEMPERATURES WILL BE IN THE
MIDDLE 30S MOST SECTIONS WITH LOWER 30S IN THE NORTHWEST.
PORTION OF PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
HI-RES GUIDANCE AND THE HRRR BOTH HIGHLIGHT LIGHT PRECIP BREAKING
OUT ACROSS THE FORECAST AREA BY MID EVENING WITH A LOW LEVEL JET
PULLING INCREASING MOISTURE INTO THE REGION. THE COLD FRONT WITH AN
UPPER WAVE TRAILING WILL CROSS THE FORECAST AREA AFTER MIDNIGHT WITH
COLD ADVECTION DEVELOPING BEHIND THE BOUNDARY. LOW LEVEL THERMALS
REMAIN WARM ENOUGH THROUGH THE EVENING THAT PRECIP INITIALLY WILL
FALL AS A LIGHT RAIN. LOW LEVEL THERMALS WILL BECOME SUPPORTIVE OF
SNOW MIXING IN AND EVENTUALLY BECOMING THE PREDOMINANT PRECIP TYPE
AFTER 06Z FROM WEST TO EAST. ANY IMPACTS FROM LIGHT SNOW WILL BE
MINIMAL AT BEST WITH SURFACE TEMPS REMAINING ABOVE FREEZING AT MOST
LOCATIONS ALL NIGHT. COULD SEE A TENTH OR SO OF SNOW IN SOME AREAS
BY DAYBREAK.
WINDS WILL REMAIN GUSTY INTO THE EVENING WITH THE LOW LEVEL JET
PERSISTING ACROSS THE OHIO VALLEY. EXPECT PEAK GUSTS AT 35-40MPH
THROUGH SUNSET...DROPPING BACK TO 25-30MPH DURING THE EVENING THEN
DIMINISHING BELOW 20MPH AFTER MIDNIGHT AS THE LOW LEVEL JET DEPARTS
OFF TO THE EAST.
TEMPS...TEMPS HAVE OUTPACED GUIDANCE BY SEVERAL DEGREES THIS
AFTERNOON WHICH MAY HAVE AN IMPACT ON EXPECTED LOWS TONIGHT.
GENERALLY WENT A COUPLE DEGREES ABOVE MOS FOR LOWS FOR THIS
REASON...WITH ALL BUT THE NORTHERN WABASH VALLEY ABOVE 32F THROUGH
SUNDAY MORNING.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 347 PM EST SAT JAN 17 2015
FORECAST CHALLENGES ARE ON CLOUDS AND TEMPS THROUGHOUT THE PERIOD
AND PRECIP CHANCES TUESDAY.
UPPER TROUGH AXIS WILL BE IN THE PROCESS OF MOVING AWAY TO THE EAST
ON SUNDAY MORNING...BUT THINK THE POTENTIAL IS THERE FOR A FEW LIGHT
SNOW SHOWERS AND/OR FLURRIES TO LINGER OVER EASTERN COUNTIES THROUGH
THE MORNING AS ANOTHER PIECE OF ENERGY ALOFT DIVES INTO THE BACK END
OF THE DEPARTING TROUGH.
PRIMARY ISSUE FOR SUNDAY WILL FOCUS ON THE LOW CLOUDS WHICH
CONSIDERING THE COLD ADVECTION...IS EXPECTED TO HAVE SOME DIFFICULTY
SCOURING OUT DURING THE DAY. OP GFS AND NAM BOTH MAINTAIN A
HEIGHTENED LEVEL OF MOISTURE AT 925MB INTO THE AFTERNOON WITH DRIER
AIR FINALLY ADVECTING INTO THE REGION BY LATE DAY. HAVE MAINTAINED
PREVIOUS FORECAST IDEA AND HELD ONTO MOSTLY CLOUDY CONDITIONS WELL
INTO THE AFTERNOON OVER WESTERN COUNTIES AND INTO THE EVENING
FURTHER EAST. THE ARRIVAL OF A HIGH PRESSURE RIDGE PASSING BY TO THE
SOUTH SUNDAY EVENING SHOULD FINALLY ENABLE SKIES TO BECOME PARTLY
CLOUDY OVER MUCH OF THE AREA.
WARM ADVECTION RETURNS MONDAY IN A QUASI-ZONAL FLOW ALOFT WITH THE
HIGH PRESSURE RIDGE SHIFTING INTO THE SOUTHEAST U S AND AN UPPER
WAVE MOVING THROUGH THE NORTHERN PLAINS. THIS WAVE WILL DIVE
SOUTHEAST INTO THE LOWER GREAT LAKES BY TUESDAY MORNING...BRINGING
WITH IT THE NEXT CHANCE FOR PRECIPITATION AS IT TRACKS THROUGH THE
AREA TUESDAY. MOISTURE WILL BE LIMITED AS THE SURFACE WAVE MOVES
INTO THE REGION TUESDAY WITH BULK OF THE BETTER FORCING ALOFT
HOLDING OFF UNTIL TUESDAY AFTERNOON AND EVENING. WILL CARRY LOW
CHANCE POPS FOR MUCH OF THE AREA TUESDAY. LOW LEVEL THERMALS LARGELY
SUPPORT A RAIN/SNOW MIX AND POSSIBLY EVEN A PERIOD OF PREDOMINANT
LIGHT RAIN TUESDAY AFTERNOON.
TEMPS...WITH EXPECTED IMPACT FROM CLOUDS ON SUNDAY...LEANED TOWARDS
COOLER METMOS FOR HIGHS. LEANED TOWARDS WARMER MAVMOS FOR MONDAY
HIGHS...THEN UNDERCUT ON TUESDAY WITH CLOUDS/PRECIP. TOOK A MOS
BLEND ON LOWS THROUGH THE SHORT TERM.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 250 AM EST SUN JAN 18 2015
MODELS CONTINUE TO ADVERTISE A STRONG MEAN UPPER RIDGE JUST OFF THE
WEST COAST MID WEEK INTO NEXT WEEKEND WHICH WILL RESULT IN A MEAN
TROUGH OVER THE EASTERN STATES. MODELS WERE ALL ALSO SHOWING SEVERAL
CLIPPERS DROPPING SOUTHEAST OVER THE GREAT LAKES AND OHIO VALLEY.
AS IS OFTEN THE CASE WITH CLIPPER SYSTEMS...THE MODELS HAVE A TOUGH
TIME COMING TOGETHER REGARDING TIMING AND STRENGTH OF THESE
INDIVIDUAL IMPULSES...SO A MODEL BLEND AND CONSISTENCY ARE FAVORED
OVER BIGGER CHANGES TO THE FORECAST FROM RUN TO RUN. THE RESULT WILL
BE SMALL POPS OVER ALL OR PART OF THE FORECAST AREA WEDNESDAY
THROUGH FRIDAY. BUFKIT SUGGESTS MOSTLY SNOW CHANCES BUT POSSIBLY
MIXED WITH RAIN SOUTH ON WEDNESDAY.
SEASONABLE TEMPERATURES WITH HIGHS MOSTLY IN THE 30S AND LOWS IN THE
20S LOOK GOOD WITH THIS TYPE OF SETUP PER THE 00Z REGIONAL BLEND.
&&
.AVIATION /DISCUSSION FOR 180606Z TAF ISSUANCE/...
ISSUED AT 1155 PM EST SAT JAN 17 2015
MVFR CEILINGS WILL DEVELOP BEFORE 12Z AS COLD ADVECTION FOLLOWING A
FRONTAL PASSAGE BUILDS STRATOCUMULUS. SKIES SHOULD CLEAR BY EVENING
AS HIGH PRESSURE ARRIVES. THERE IS A SMALL CHANCE OF FLURRIES UNTIL
THE CLOUDS BREAK. VISIBILITIES SHOULD STAY VFR IN ANY FLURRIES.
WINDS ARE GOING TO BE MOSTLY WEST. THEY WILL BE 10-15 KNOTS UNTIL
NEAR SUNSET...THEN DROP TO 5 KNOTS OR LESS. GUSTS AROUND 20 KNOTS
SHOULD BE EXPECTED FROM LATE MORNING INTO THE AFTERNOON WHEN
CONDITIONS ARE BEST FOR AIR TO MIX TO THE SURFACE FROM ALOFT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/JH
SHORT TERM...RYAN
LONG TERM...MK
AVIATION...JK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1155 PM EST SAT JAN 17 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 347 PM EST SAT JAN 17 2015
A COLD FRONT WILL BRING THE CHANCE FOR LIGHT PRECIPITATION TONIGHT
ALONG WITH A RETURN TO COOLER WEATHER SUNDAY. AFTER A BRIEF WARMUP
MONDAY...ANOTHER WEAK SYSTEM WILL BRING LOW CHANCES FOR LIGHT RAIN
AND SNOW TUESDAY AND TUESDAY NIGHT. YET ANOTHER UPPER WAVE MAY BRING
SOME LIGHT SNOW THURSDAY NIGHT AND FRIDAY. SEASONABLE TEMPERATURES
ARE EXPECTED FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 955 PM EST SAT JAN 17 2015
.UPDATE...BAND OF SHOWERS HAVE DEVELOPED OVER NORTHWEST INDIANA AND
EAST CENTRAL ILLINOIS AND THESE SHOULD SPREAD INTO OUR REGION OVER
THE NEXT FEW HOURS. ALL IN ALL THE CURRENT FORECAST IS ON TRACK.
ONLY MINOR CHANGES MADE...MAINLY TO DELAY THE CHANGE OVER TO MIXED
PRECIPITATION AN HOUR OR TWO GIVEN THAT TEMPERATURES ARE STILL WELL
ABOVE FREEZING. STILL LOOKS LIKE LOW TEMPERATURES WILL BE IN THE
MIDDLE 30S MOST SECTIONS WITH LOWER 30S IN THE NORTHWEST.
PORTION OF PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
HI-RES GUIDANCE AND THE HRRR BOTH HIGHLIGHT LIGHT PRECIP BREAKING
OUT ACROSS THE FORECAST AREA BY MID EVENING WITH A LOW LEVEL JET
PULLING INCREASING MOISTURE INTO THE REGION. THE COLD FRONT WITH AN
UPPER WAVE TRAILING WILL CROSS THE FORECAST AREA AFTER MIDNIGHT WITH
COLD ADVECTION DEVELOPING BEHIND THE BOUNDARY. LOW LEVEL THERMALS
REMAIN WARM ENOUGH THROUGH THE EVENING THAT PRECIP INITIALLY WILL
FALL AS A LIGHT RAIN. LOW LEVEL THERMALS WILL BECOME SUPPORTIVE OF
SNOW MIXING IN AND EVENTUALLY BECOMING THE PREDOMINANT PRECIP TYPE
AFTER 06Z FROM WEST TO EAST. ANY IMPACTS FROM LIGHT SNOW WILL BE
MINIMAL AT BEST WITH SURFACE TEMPS REMAINING ABOVE FREEZING AT MOST
LOCATIONS ALL NIGHT. COULD SEE A TENTH OR SO OF SNOW IN SOME AREAS
BY DAYBREAK.
WINDS WILL REMAIN GUSTY INTO THE EVENING WITH THE LOW LEVEL JET
PERSISTING ACROSS THE OHIO VALLEY. EXPECT PEAK GUSTS AT 35-40MPH
THROUGH SUNSET...DROPPING BACK TO 25-30MPH DURING THE EVENING THEN
DIMINISHING BELOW 20MPH AFTER MIDNIGHT AS THE LOW LEVEL JET DEPARTS
OFF TO THE EAST.
TEMPS...TEMPS HAVE OUTPACED GUIDANCE BY SEVERAL DEGREES THIS
AFTERNOON WHICH MAY HAVE AN IMPACT ON EXPECTED LOWS TONIGHT.
GENERALLY WENT A COUPLE DEGREES ABOVE MOS FOR LOWS FOR THIS
REASON...WITH ALL BUT THE NORTHERN WABASH VALLEY ABOVE 32F THROUGH
SUNDAY MORNING.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 347 PM EST SAT JAN 17 2015
FORECAST CHALLENGES ARE ON CLOUDS AND TEMPS THROUGHOUT THE PERIOD
AND PRECIP CHANCES TUESDAY.
UPPER TROUGH AXIS WILL BE IN THE PROCESS OF MOVING AWAY TO THE EAST
ON SUNDAY MORNING...BUT THINK THE POTENTIAL IS THERE FOR A FEW LIGHT
SNOW SHOWERS AND/OR FLURRIES TO LINGER OVER EASTERN COUNTIES THROUGH
THE MORNING AS ANOTHER PIECE OF ENERGY ALOFT DIVES INTO THE BACK END
OF THE DEPARTING TROUGH.
PRIMARY ISSUE FOR SUNDAY WILL FOCUS ON THE LOW CLOUDS WHICH
CONSIDERING THE COLD ADVECTION...IS EXPECTED TO HAVE SOME DIFFICULTY
SCOURING OUT DURING THE DAY. OP GFS AND NAM BOTH MAINTAIN A
HEIGHTENED LEVEL OF MOISTURE AT 925MB INTO THE AFTERNOON WITH DRIER
AIR FINALLY ADVECTING INTO THE REGION BY LATE DAY. HAVE MAINTAINED
PREVIOUS FORECAST IDEA AND HELD ONTO MOSTLY CLOUDY CONDITIONS WELL
INTO THE AFTERNOON OVER WESTERN COUNTIES AND INTO THE EVENING
FURTHER EAST. THE ARRIVAL OF A HIGH PRESSURE RIDGE PASSING BY TO THE
SOUTH SUNDAY EVENING SHOULD FINALLY ENABLE SKIES TO BECOME PARTLY
CLOUDY OVER MUCH OF THE AREA.
WARM ADVECTION RETURNS MONDAY IN A QUASI-ZONAL FLOW ALOFT WITH THE
HIGH PRESSURE RIDGE SHIFTING INTO THE SOUTHEAST U S AND AN UPPER
WAVE MOVING THROUGH THE NORTHERN PLAINS. THIS WAVE WILL DIVE
SOUTHEAST INTO THE LOWER GREAT LAKES BY TUESDAY MORNING...BRINGING
WITH IT THE NEXT CHANCE FOR PRECIPITATION AS IT TRACKS THROUGH THE
AREA TUESDAY. MOISTURE WILL BE LIMITED AS THE SURFACE WAVE MOVES
INTO THE REGION TUESDAY WITH BULK OF THE BETTER FORCING ALOFT
HOLDING OFF UNTIL TUESDAY AFTERNOON AND EVENING. WILL CARRY LOW
CHANCE POPS FOR MUCH OF THE AREA TUESDAY. LOW LEVEL THERMALS LARGELY
SUPPORT A RAIN/SNOW MIX AND POSSIBLY EVEN A PERIOD OF PREDOMINANT
LIGHT RAIN TUESDAY AFTERNOON.
TEMPS...WITH EXPECTED IMPACT FROM CLOUDS ON SUNDAY...LEANED TOWARDS
COOLER METMOS FOR HIGHS. LEANED TOWARDS WARMER MAVMOS FOR MONDAY
HIGHS...THEN UNDERCUT ON TUESDAY WITH CLOUDS/PRECIP. TOOK A MOS
BLEND ON LOWS THROUGH THE SHORT TERM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 233 PM EST SAT JAN 17 2015
MODELS CONTINUE TO DIFFER IN THE DETAILS OF SYSTEMS MOVING THROUGH
THE UPPER TROUGH THAT WILL BE ACROSS THE EASTERN USA DURING THE LONG
TERM PERIOD. THUS CONFIDENCE IS LOW THROUGH THE PERIOD AS THESE
TYPES OF SYSTEMS ARE HARD TO PIN DOWN THAT FAR OUT. HAD TO ALTER
SUPERBLEND/S POPS...OTHERWISE GENERALLY STUCK CLOSE TO IT DUE TO THE
UNCERTAINTIES.
LOW CHANCES FOR PRECIPITATION WILL CONTINUE TUESDAY NIGHT AS ONE
SYSTEM EXITS. FOR WEDNESDAY/WEDNESDAY NIGHT KEPT A DRY FORECAST AND
REMOVED ANY SUPERBLEND SLIGHT CHANCE POPS FOR THE SAKE OF
CONTINUITY.
ON THURSDAY SUPERBLEND IS DRY BUT AGAIN FOR SAKE OF CONTINUITY KEPT
SOME SMALL POPS IN THE FAR EAST. ON FRIDAY...12Z GFS AND CANADIAN
GLOBAL BRING A CLIPPER THROUGH THE AREA. 12Z ECMWF IS DRY.
SUPERBLEND IS DRY...BUT WITH 2 MODELS SHOWING A DECENT CHANCE FOR
PRECIPITATION...DECIDED TO GO WITH SLIGHT CHANCE POPS FOR NOW.
SATURDAY LOOKS DRY AT THIS POINT.
TEMPERATURES LOOK SEASONABLE FOR THE MOST PART.
&&
.AVIATION /DISCUSSION FOR 180606Z TAF ISSUANCE/...
ISSUED AT 1155 PM EST SAT JAN 17 2015
MVFR CEILINGS WILL DEVELOP BEFORE 12Z AS COLD ADVECTION FOLLOWING A
FRONTAL PASSAGE BUILDS STRATOCUMULUS. SKIES SHOULD CLEAR BY EVENING
AS HIGH PRESSURE ARRIVES. THERE IS A SMALL CHANCE OF FLURRIES UNTIL
THE CLOUDS BREAK. VISIBILITIES SHOULD STAY VFR IN ANY FLURRIES.
WINDS ARE GOING TO BE MOSTLY WEST. THEY WILL BE 10-15 KNOTS UNTIL
NEAR SUNSET...THEN DROP TO 5 KNOTS OR LESS. GUSTS AROUND 20 KNOTS
SHOULD BE EXPECTED FROM LATE MORNING INTO THE AFTERNOON WHEN
CONDITIONS ARE BEST FOR AIR TO MIX TO THE SURFACE FROM ALOFT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/JH
SHORT TERM...RYAN
LONG TERM...50
AVIATION...JK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS JACKSON KY
145 PM EST SUN JAN 18 2015
.UPDATE...
ISSUED AT 145 PM EST SUN JAN 18 2015
DRIER AIR MIXING INTO THE BOUNDARY LAYER HAS EATEN AWAY AT THE CU
FIELD THAT DEVELOPED MID MORNING...RESULTING IN A BIT MORE SUNSHINE
THAN ANTICIPATED THIS AFTERNOON. AS A RESULT HAVING TO ADJUST
AFTERNOON HIGHS UP SOME TO ACCOUNT FOR ADDITIONAL SUNSHINE. SEEING
THE OCCASIONAL REDEVELOPMENT OF LIGHT ECHOS IN THE FAR EAST...SO
ISOLD TO SCT POPS FOR THE LATE AFTERNOON IN OUR EXTREME EAST STILL
APPEARS WARRANTED. CURRENT FORECAST HAS THIS POTENTIAL COVERED.
UPDATE ISSUED AT 1030 AM EST SUN JAN 18 2015
RAIN HAS EXITED THE AREA...THOUGH THERE COULD BE A FEW SPRINKLES
STILL OUT THERE ACROSS OUR EAST. AFTER A LULL IN PRECIP THROUGH THE
MID DAY TIME FRAME...ADDITIONAL SHORT WAVE ENERGY ALOFT IN COMBINATION
WITH DIURNAL HEATING MAY ALLOW FOR SOME ISOLD TO SCT SHOWERS TO
REFORM ACROSS OUR EXTREME EAST LATE THIS AFTERNOON. APPEARS THAT THE
RAP...NAM AND GFS HAVE ALL PICKED UP ON THIS POTENTIAL. THE HRRR HAS
AS WELL...BUT IS ADVERTISING A SLIGHTLY DIFFERENT AREAL THREAT WITH
RESPECT TO COVERAGE. WILL WATCH TRENDS OVER THE NEXT FEW HOURS. FOR
NOW INCREASED POPS IN OUR EXTREME EAST FOR LATE THIS AFTERNOON INTO
EARLY THIS EVENING. OTHERWISE BROUGHT GRIDS IN LINE WITH HOURLY OBS.
FOR TEMPERATURE TRENDS...WEAK CAA AND REDEVELOPMENT OF BOUNDARY LAYER
CU FIELD WILL BATTLE DIURNAL HEATING RESULTING IN NEARLY STEADY TO
SLIGHTLY WARMING TEMPS DURING THE NEXT SEVERAL HOURS.
UPDATE ISSUED AT 730 AM EST SUN JAN 18 2015
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATION...
SATELLITE...AND OBSERVATION TRENDS. THIS LED TO GENERALLY A QUICKER
PROGRESSION OF THE BAND OF SHOWERS OUT OF THE CWA AND A LITTLE COLDER
TEMPS IN WESTERN SECTIONS. OTHERWISE...NO SUBSTANTIAL CHANGES WERE
MADE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EST SUN JAN 18 2015
A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT ARE APPROACHING THE
REGION FROM THE WEST ATTM. ALTHOUGH AMOUNTS HAVE BEEN LIGHT...REGIONAL
ASOS SITES AND KY MESONET SITES INDICATE THAT MEASURABLE RAIN HAS
FALLEN ALONG THE NARROW BAND OF SHOWERS ACROSS CENTRAL KY. THIS BAND
OF SHOWERS WILL MOVE EAST INTO THE REGION PRIOR TO SUNRISE AND MAY BE
HALF WAY ACROSS THE REGION BY SUNRISE. THE OTHER FEATURE AT THIS TIME
IS DECOUPLED EASTERN VALLEYS IN THE 30S IN SOME PLACES WHILE THE TOP
OF BLACK MTN IS ALSO LINGER IN THE 30S. IN FACT...THE TOP OF BLACK
MTN IS 33 WITH A DEW POINT OF 25 ATTM.
WE HAVE OPTED TO GO WITH A NARROW WINDOW OF CATEGORICAL POPS AS THE
BAND OF SHOWERS MOVING THROUGH THE REGION AS IT WILL ALSO LIKELY
MEASURE LESS THAN A TENTH OF AN INCH AS IT ROLLS ACROSS EAST KY
THROUGH MID MORNING. AS CLOUDS THICKEN AND BEFORE THE RAIN ARRIVES
TEMPS IN THE DECOUPLED AREAS THROUGH REBOUND INTO THE UPPER 30S TO
LOWER 40S. MIN TEMPS ALSO WILL BE REACHED IN SOME AREAS WITH
WETBULBING. CONFIDENCE IN THE THE DEGREE OF SKY COVER FROM MIDDAY
INTO TONIGHT IS LOWER THAN AVERAGE AS MODEL TIME HEIGHT SECTIONS FROM
THE NAM AND GFS INDICATE AT LEAST SOME CU OR STRATOCU LINGERING...BUT
AT PRESENT THERE IS A SHARP BACK EDGE. IF CLEARING DOES OCCUR...THE
MAX WILL BE AT LEAST A CAT HIGHER THAN THE CURRENT FORECAST AND LOWS
TONIGHT WOULD ALSO BE LOWER. MAX T FOR TODAY SHOULD BE AT LEAST 10
DEGREES LOWER THAN ON SAT ON AVERAGE HOWEVER...AS 850 MB TEMPS WILL
DROP ABOUT 6 DEGREES C FROM SATURDAY.
ADDITIONAL DISTURBANCES IN NW FLOW WOULD ARGUE FOR THE POTENTIAL FOR
AT LEAST SOME LOW CLOUDS LINGERING INTO TONIGHT AND POSSIBLY MONDAY
AS DOES A WEAK WARM FRONT ASSOCIATED WITH A SYSTEM MOVING THROUGH THE
PLAINS. THIS LEADS TO LOWER THAN AVERAGE CONFIDENCE IN MIN T FOR
TONIGHT AND THE DAY ON MONDAY. HOWEVER...ATTM...THIS WARM FRONT IS
NOT EXPECTED TO BE TOO MOISTURE STARVED TO PRODUCE ANY PRECIPITATION.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 310 AM EST SUN JAN 18 2015
THE PERIOD WILL START OUT QUIET WITH ZONAL FLOW CONTINUING. CLEAR
SKIES SHOULD PROVIDE A SHARP DROP OFF IN TEMPERATURES FOR VALLEY
LOCATIONS MONDAY NIGHT. HOWEVER...TEMPERATURES WILL REBOUND NICELY
ON TUESDAY WITH HIGHS REACHING THE 50S ONCE MORE. A STRONG MID LEVEL
TROUGH WILL THEN DIVE SOUTHEAST ACROSS THE OHIO RIVER VALLEY LATE
TUESDAY AND TUESDAY NIGHT WITH PRECIPITATION DEVELOPING ACROSS THE
AREA. BOUNDARY LAYER IS EXPECTED TO REMAIN SOMEWHAT MILD INTO
WEDNESDAY MORNING...SUPPORTING MAINLY RAIN. THE EXCEPTION TO THIS
MAY BE IN THE HIGH TERRAIN NEAR THE VIRGINIA BORDER WHERE SOME SNOW
MAY BE MORE LIKELY. THIS SYSTEM HAS THE DYNAMICS AND MOISTURE TO
SUPPORT INCREASED PRECIPITATION CHANCES...SO HAVE GONE WITH A PERIOD
OF LIKELY/CATEGORICAL POPS ACROSS PORTIONS OF EASTERN KENTUCKY
TUESDAY NIGHT. PRECIPITATION WILL WIND DOWN ON WEDNESDAY...BUT SOME
RAIN MAY LINGER IN THE EAST THROUGH THE DAY. STILL SOME QUESTIONS
REGARDING THE WEDNESDAY NIGHT THROUGH FRIDAY TIME PERIOD...AS MODELS
SUPPORT SOME MOISTURE HANGING ON IN EAST KENTUCKY AND POSSIBLY SOME
FLURRIES OR DRIZZLE AT TIMES. CONFIDENCE IS LOW ON THIS LIGHT
PRECIPITATION FORECAST AND HAVE OPTED TO LEAVE THE FORECAST DRY DUE
TO LOW CONFIDENCE. MODELS REMAIN ALL OVER THE PLACE THROUGH THE
WEEKEND...BUT AGAIN...NO ORGANIZED SYSTEMS SUPPORT A DRY FORECAST
GOING FORWARD. AFTER A COOLER END TO THE WEEK...IT DOES APPEAR
TEMPERATURES WILL MODERATE AGAIN AS WE HEAD THROUGH NEXT WEEKEND.
THIS MAY GIVE WAY TO A STORM SYSTEM AS WE HEAD INTO LATE WEEKEND OR
EARLY THE FOLLOWING WEEK...WHICH AT THIS TIME LOOKS TO BE MAINLY
RAIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 145 PM EST SUN JAN 18 2015
GENERALLY LOOKING AT VFR CONDITIONS THROUGH THE TAF FORECAST PERIOD.
HOWEVER AN OCCASIONAL BUT TEMPORARY DROP INTO MVFR TERRITORY CAN NOT
BE RULED OUT EARLY THIS AFTERNOON BASED ON SFC OBS ACROSS THE REGION.
BUT OVERALL CIGS AND FLIGHT CONDITIONS CONTINUE TO IMPROVE AND WE
SHOULD SEE SKIES CLEAR THROUGH THE OVERNIGHT. WINDS BEHIND THIS
MORNING/S FROPA CONTINUE TO GUST DECENTLY OUT OF THE WEST. WINDS ARE
GENERALLY RUNNING AROUND 10 KTS WITH THE OCCASIONAL GUSTS TO ABOUT 20
KTS. THESE SHOULD SLACKEN THROUGH THE LATE AFTERNOON...BUT PICK UP
AGAIN TO AROUND 6-7 KTS TOMORROW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...JP
LONG TERM...KAS
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
1030 AM EST SUN JAN 18 2015
.UPDATE...
ISSUED AT 1030 AM EST SUN JAN 18 2015
RAIN HAS EXITED THE AREA...THOUGH THERE COULD BE A FEW SPRINKLES
STILL OUT THERE ACROSS OUR EAST. AFTER A LULL IN PRECIP THROUGH THE
MID DAY TIME FRAME...ADDITIONAL SHORT WAVE ENERGY ALOFT IN COMBINATION
WITH DIURNAL HEATING MAY ALLOW FOR SOME ISOLD TO SCT SHOWERS TO
REFORM ACROSS OUR EXTREME EAST LATE THIS AFTERNOON. APPEARS THAT THE
RAP...NAM AND GFS HAVE ALL PICKED UP ON THIS POTENTIAL. THE HRRR HAS
AS WELL...BUT IS ADVERTISING A SLIGHTLY DIFFERENT AREAL THREAT WITH
RESPECT TO COVERAGE. WILL WATCH TRENDS OVER THE NEXT FEW HOURS. FOR
NOW INCREASED POPS IN OUR EXTREME EAST FOR LATE THIS AFTERNOON INTO
EARLY THIS EVENING. OTHERWISE BROUGHT GRIDS IN LINE WITH HOURLY OBS.
FOR TEMPERATURE TRENDS...WEAK CAA AND REDEVELOPMENT OF BOUNDARY LAYER
CU FIELD WILL BATTLE DIURNAL HEATING RESULTING IN NEARLY STEADY TO
SLIGHTLY WARMING TEMPS DURING THE NEXT SEVERAL HOURS.
UPDATE ISSUED AT 730 AM EST SUN JAN 18 2015
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT OBSERVATION...
SATELLITE...AND OBSERVATION TRENDS. THIS LED TO GENERALLY A QUICKER
PROGRESSION OF THE BAND OF SHOWERS OUT OF THE CWA AND A LITTLE COLDER
TEMPS IN WESTERN SECTIONS. OTHERWISE...NO SUBSTANTIAL CHANGES WERE
MADE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EST SUN JAN 18 2015
A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT ARE APPROACHING THE
REGION FROM THE WEST ATTM. ALTHOUGH AMOUNTS HAVE BEEN LIGHT...REGIONAL
ASOS SITES AND KY MESONET SITES INDICATE THAT MEASURABLE RAIN HAS
FALLEN ALONG THE NARROW BAND OF SHOWERS ACROSS CENTRAL KY. THIS BAND
OF SHOWERS WILL MOVE EAST INTO THE REGION PRIOR TO SUNRISE AND MAY BE
HALF WAY ACROSS THE REGION BY SUNRISE. THE OTHER FEATURE AT THIS TIME
IS DECOUPLED EASTERN VALLEYS IN THE 30S IN SOME PLACES WHILE THE TOP
OF BLACK MTN IS ALSO LINGER IN THE 30S. IN FACT...THE TOP OF BLACK
MTN IS 33 WITH A DEWPOINT OF 25 ATTM.
WE HAVE OPTED TO GO WITH A NARROW WINDOW OF CATEGORICAL POPS AS THE
BAND OF SHOWERS MOVING THROUGH THE REGION AS IT WILL ALSO LIKELY
MEASURE LESS THAN A TENTH OF AN INCH AS IT ROLLS ACROSS EAST KY
THROUGH MID MORNING. AS CLOUDS THICKEN AND BEFORE THE RAIN ARRIVES
TEMPS IN THE DECOUPLED AREAS THROUGH REBOUND INTO THE UPPER 30S TO
LOWER 40S. MIN TEMPS ALSO WILL BE REACHED IN SOME AREAS WITH
WETBULBING. CONFIDENCE IN THE THE DEGREE OF SKY COVER FROM MIDDAY
INTO TONIGHT IS LOWER THAN AVERAGE AS MODEL TIME HEIGHT SECTIONS FROM
THE NAM AND GFS INDICATE AT LEAST SOME CU OR STRATOCU LINGERING...BUT
AT PRESENT THERE IS A SHARP BACK EDGE. IF CLEARING DOES OCCUR...THE
MAX WILL BE AT LEAST A CAT HIGHER THAN THE CURRENT FORECAST AND LOWS
TONIGHT WOULD ALSO BE LOWER. MAX T FOR TODAY SHOULD BE AT LEAST 10
DEGREES LOWER THAN ON SAT ON AVERAGE HOWEVER...AS 850 MB TEMPS WILL
DROP ABOUT 6 DEGREES C FROM SATURDAY.
ADDITIONAL DISTURBANCES IN NW FLOW WOULD ARGUE FOR THE POTENTIAL FOR
AT LEAST SOME LOW CLOUDS LINGERING INTO TONIGHT AND POSSIBLY MONDAY
AS DOES A WEAK WARM FRONT ASSOCIATED WITH A SYSTEM MOVING THROUGH THE
PLAINS. THIS LEADS TO LOWER THAN AVERAGE CONFIDENCE IN MIN T FOR
TONIGHT AND THE DAY ON MONDAY. HOWEVER...ATTM...THIS WARM FRONT IS
NOT EXPECTED TO BE TOO MOISTURE STARVED TO PRODUCE ANY PRECIPITATION.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 310 AM EST SUN JAN 18 2015
THE PERIOD WILL START OUT QUIET WITH ZONAL FLOW CONTINUING. CLEAR
SKIES SHOULD PROVIDE A SHARP DROP OFF IN TEMPERATURES FOR VALLEY
LOCATIONS MONDAY NIGHT. HOWEVER...TEMPERATURES WILL REBOUND NICELY
ON TUESDAY WITH HIGHS REACHING THE 50S ONCE MORE. A STRONG MID LEVEL
TROUGH WILL THEN DIVE SOUTHEAST ACROSS THE OHIO RIVER VALLEY LATE
TUESDAY AND TUESDAY NIGHT WITH PRECIPITATION DEVELOPING ACROSS THE
AREA. BOUNDARY LAYER IS EXPECTED TO REMAIN SOMEWHAT MILD INTO
WEDNESDAY MORNING...SUPPORTING MAINLY RAIN. THE EXCEPTION TO THIS
MAY BE IN THE HIGH TERRAIN NEAR THE VIRGINIA BORDER WHERE SOME SNOW
MAY BE MORE LIKELY. THIS SYSTEM HAS THE DYNAMICS AND MOISTURE TO
SUPPORT INCREASED PRECIPITATION CHANCES...SO HAVE GONE WITH A PERIOD
OF LIKELY/CATEGORICAL POPS ACROSS PORTIONS OF EASTERN KENTUCKY
TUESDAY NIGHT. PRECIPITATION WILL WIND DOWN ON WEDNESDAY...BUT SOME
RAIN MAY LINGER IN THE EAST THROUGH THE DAY. STILL SOME QUESTIONS
REGARDING THE WEDNESDAY NIGHT THROUGH FRIDAY TIME PERIOD...AS MODELS
SUPPORT SOME MOISTURE HANGING ON IN EAST KENTUCKY AND POSSIBLY SOME
FLURRIES OR DRIZZLE AT TIMES. CONFIDENCE IS LOW ON THIS LIGHT
PRECIPITATION FORECAST AND HAVE OPTED TO LEAVE THE FORECAST DRY DUE
TO LOW CONFIDENCE. MODELS REMAIN ALL OVER THE PLACE THROUGH THE
WEEKEND...BUT AGAIN...NO ORGANIZED SYSTEMS SUPPORT A DRY FORECAST
GOING FORWARD. AFTER A COOLER END TO THE WEEK...IT DOES APPEAR
TEMPERATURES WILL MODERATE AGAIN AS WE HEAD THROUGH NEXT WEEKEND.
THIS MAY GIVE WAY TO A STORM SYSTEM AS WE HEAD INTO LATE WEEKEND OR
EARLY THE FOLLOWING WEEK...WHICH AT THIS TIME LOOKS TO BE MAINLY
RAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
UPDATE ISSUED AT 1030 AM EST SUN JAN 18 2015
POST FRONTAL CU FIELD HAS DEVELOPED QUICKLY IN WAKE OF FRONTAL
ZONE PASSAGE. AS A RESULT MVFR CIGS HAVE DEVELOPED AND WILL AMEND AS
REQUIRED. EXPECT ONLY A GRADUAL IMPROVEMENT...LIFTING THROUGH THE
REMAINDER OF THE DAY.
ISSUED AT 735 AM EST SUN JAN 18 2015
CIGS WILL IMPROVE TO VFR AT ALL THE TAF SITES BY 14Z AS A BAND OF
SHOWERS ALONG A COLD FRONT EXITS. CIGS SHOULD THEN REMAIN VFR THROUGH
THE END OF THE PERIOD. WINDS WILL BE SOUTHWEST TO WEST AT AROUND 10KT
WITH SOME GUSTS UP TO 20KT POSSIBLE. WINDS WILL SLACKEN AROUND 0Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...JP
LONG TERM...KAS
AVIATION...RAY
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
154 AM EST SUN JAN 18 2015
.UPDATE...
ISSUED AT 130 AM EST SUN JAN 18 2015
HOURLY GRIDS HAVE BEEN FRESHENED UP TO ACCOUNT FOR THE DECOUPLING THAT
HAS OCCURRED IN SOME VALLEY LOCATIONS...BUT A GENERAL MIXING OUT OF
THESE DECOUPLED VALLEYS HAS BEEN OCCURRING FROM WEST TO EAST. CWOP AND
MESONET STATIONS INDICATE THAT THE MIXING OUT HAS OCCURRED AS FAR
EAST AS THE KY RIVER BASIN AND MOST OF THE LIKING RIVER BASIN AS
WELL. A FEW SPOTS IN THE BIG SANDY REGION ARE AROUND THE FREEZING
MARK. HOWEVER...EVEN THESE LOCATIONS WILL CLIMB ABOVE FREEZING AS
CLOUDS INCREASE AND THE PRESSURE GRADIENT INCREASES OVERNIGHT AS WELL.
SHOWERS TOWARD DAWN ALSO WILL ADD TO THE COMPLEXITY OF THE
TEMPERATURE CURVE AS WETBULBING SHOULD OCCUR. MEANWHILE...THE TOP OF BLACK
MTN IS CURRENTLY 34 DEGREES WITH A DEWPOINT OF 26...SO WETBULBING
SHOULD ALLOW MOST PRECIP THAT OCCURS THERE OR ELEVATIONS ABOVE 3500
FEET IN HARLAN COUNTY TO FALL AS SOME SNOW. THIS WILL AFFECT A VERY
SMALL AREA...HOWEVER. ALSO...WINDS NEAR 20 MPH ARE OCCURRING IN
EXPOSED LOCATIONS ABOVE 2500 FEET...WITH SOME 10 TO 15 MPH WINDS ALSO
RECENTLY OBSERVED FROM ABOUT THE ESCARPMENT WEST. ADJUSTMENTS HAVE
ALSO BEEN MADE TO THE WINDS OVERNIGHT.
RECENT SREF GUIDANCE AS WELL AS HRRR DATA SHOW A SOLID...BUT BRIEF
WIND OF SHOWERS AND THE MAV GUIDANCE FOR NORTHERN LOCATIONS SUPPORTS
THIS. AS THIS MOVES EAST...KY MESONET DATA HAS BEEN SHOWING THESE
MEASURING FROM THE WESTERN KY PARKWAY NORTH INTO INDIANA. WITH THE
SHORTWAVE EXPECTED TO DIG AND BECOME NEUTRALLY TITLED IF NOT A BIT
NEGATIVELY TILTED BY THE TIME IT EXITS THE CENTRAL APPALACHIAN REGION
AND LOWER OH VALLEY REGION MEASURABLE PRECIP SHOULD OCCUR...BUT
AMOUNTS SHOULD BE LIGHT. POPS HAVE BEEN RAISED TO LIKELY TO CAT FOR A
WINDOW FROM THE LATE OVERNIGHT HOURS THROUGH MID MORNING ON SUNDAY
THAT TRANSLATES FROM WEST TO EAST.
UPDATE ISSUED AT 1100 PM EST SAT JAN 17 2015
THE CURRENT FORECAST IS MOSTLY ON TRACK WITH A LARGE RIDGE AND VALLEY
TEMPERATURE SPLIT STILL IN PLACE THROUGH PARTS OF EASTERN KENTUCKY.
FOR INSTANCE...QUICKSAND MESONET IS AT 31 DEGREES WHILE A COUPLE OF
MILES AWAY AND 700 FEET OR SO HIGHER THE JKL OFFICE IS SITTING AT 48
DEGREES. HAVE MADE SOME FINE TUNE ADJUSTMENTS TO THESE TEMPERATURES
AND ALSO THE LOWS OVERNIGHT. THE TIMING OF THE THICKER CLOUDS
ARRIVING AND PCPN CHANCES LOOK TO BE ON TRACK WITH THE CURRENT
MODELS. THESE MINOR GRID UPDATES HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
UPDATE ISSUED AT 720 PM EST SAT JAN 17 2015
23Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING THROUGH THE
GREAT LAKES. ACCOMPANYING THE LOW IS A COLD FRONT CROSSING THE
MIDWEST AND INBOUND TO THE OHIO VALLEY. EAST KENTUCKY IS AHEAD OF
THIS BOUNDARY WITH SOUTH TO SOUTHWEST WINDS SUPPORTING TEMPERATURES
IN THE UPPER 40S AND LOWER 50S FOR MUCH OF THE AREA. HOWEVER...UNDER
STILL CLEAR SKIES...THE MOST SHELTERED VALLEYS HAVE DROPPED OFF FAST
TOWARD THE DEWPOINTS...GENERALLY IN THE MID 20S TO LOWER 30S
THROUGHOUT THE AREA. TEMPERATURES IN THESE PLACES ARE IN THE MID 30S
TO LOW 40S ALREADY THIS EVENING. HAVE UPDATED THE FORECAST TO
PRIMARILY HONE IN ON THIS QUICK DROP OFF IN THE VALLEYS. DO ALLOW
THESE SPOTS TO MIX OUT AND WARM TOWARDS DAWN ON THE CUSP OF THE COLD
FRONT. THICKENING AND LOWERING CLOUDS WILL MOVE INTO THE AREA AFTER
MIDNIGHT HELPING TO CAP THE TEMP DROP. WHEN THE FRONT...AND RAIN THAT
WILL ACCOMPANY IT...MOVES INTO EASTERN KENTUCKY THE TEMPERATURES WILL
BOUNCE BACK UP IN THE SHELTERED VALLEYS MITIGATING ANY CONCERN FOR
SOME FREEZING PCPN AT THE LEADING EDGE OF ANY RAIN. HAVE ALSO FINE
TUNED THE FRONT/S PASSAGE AND TIMING OF THE RAIN ASSOCIATED WITH IT
IN THE POP AND WX GRIDS THROUGH MID DAY SUNDAY. THESE UPDATES HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 340 PM EST SAT JAN 17 2015
GUSTY SSW WINDS HAVE PUSHED TEMPERATURES INTO THE MID AND UPPER 50S
ACROSS MUCH OF THE AREA THIS AFTERNOON. WINDS HAVE BEEN GUSTING TO
20 TO 30 MPH...AND WINDS WILL REMAIN GUSTY ON THE THE HIGHER RIDGES
OVERNIGHT. THE DEEPER EASTERN VALLEYS MAY DECOUPLE TONIGHT...ALLOWING
TEMPERATURES TO FALL INTO THE 30S WHILE MOST AREAS SEE LOWS CLOSER TO
40.
AT 18Z A MID LEVEL TROF WAS MOVING OUT OF THE PLAINS AND INTO THE MS
VALLEY. THE ASSOCIATED SURFACE COLD FRONT EXTENDED FROM WESTERN UPPER
MI SSW TO NE OK. AT THIS POINT THERE IS VERY LITTLE MOISTURE
ASSOCIATED WITH THE FRONT. MOISTURE WILL INCREASE WITH THE FRONT AND
WITH THE UPPER LEVEL TROUGH...BUT DEEP MOISTURE WILL STILL BE LIMITED
AS THESE FEATURES APPROACH THE AREA TONIGHT.
LOW CLOUDS WILL MOVE INTO THE AREA IN ADVANCE OF THE COLD FRONT
TONIGHT...WITH THE SURFACE FRONT MOVING ACROSS THE AREA EARLY
SUNDAY MORNING AND WINDS SHIFTING TO A MORE WESTERLY DIRECTION. THE
BEST LIFT AND MOISTURE WILL BE FROM THE NORTHERN PART OF THE FORECAST
AREA N INTO OH. AS SUCH WILL CONTINUE WITH PREVIOUS FORECAST
THINKING AND KEEP LIKELY RAIN PROBABILITIES IN THE NORTH WITH LOWER
CHANCES IN THE SOUTH. TIMING FOR BEST CHANCE OF RAIN STILL LOOKS TO
BE EARLY IN THE DAY ON SUNDAY. WEAK CAA WILL FOLLOW THE FRONT EARLY
SUNDAY...BUT BY EVENING WEAK WAA WILL HAVE ALREADY BEGUN. DESPITE THE
LIMITED COLD AIR BEHIND THE FRONT...LOW CLOUDS WILL INHIBIT
TEMPERATURE RISES ON SUNDAY...WITH TEMPERATURES GETTING NO HIGHER
THAN THE LOWER TO MIDDLE 40S. CLOUDS SHOULD DECREASE SUNDAY
NIGHT...BUT A WEAK WAVE OF LOW PRESSURE MOVING INTO THE MID MS VALLEY
WILL KEEP SOME CLOUD ACROSS THE AREA. HOW MUCH CLOUD COVER WE HAVE
SUNDAY NIGHT IS IN QUESTION AND THE MINIMUM TEMPERATURES SUNDAY NIGHT
WILL BE VERY DEPENDENT ON SKY COVER. AT THIS TIME WILL GO WITH A
MIDDLE GROUND ON THE SUNDAY NIGHT SKY COVER FORECAST AND GO WITH
TEMPERATURES AT FREEZING OR A LITTLE BELOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 3 PM EST SAT JAN 17 2015
THE EXTENDED PERIOD WILL START OFF DRY AND MILD...AS A RIDGE OF HIGH
PRESSURE MOVING EAST ALONG THE GULF COAST EXERTS ITS INFLUENCE OF THE
REGION. MONDAY AND TUESDAY WILL LIKELY SEE TEMPERATURES TOP OUT IN
THE LOWER 50S FOR MOST LOCATIONS...PARTICULARLY TUESDAY. THE WARM AIR
WILL BE BROUGHT INTO THE AREA ON SOUTHERLY WINDS TO START OFF THE NEW
WORK WEEK. THE WARM WEATHER WILL BE SHORT LIVED...HOWEVER...AS A
SERIES OF SHORT WAVES MOVING ACROSS THE GREAT LAKES AND OHIO VALLEY
REGIONS BRING COLDER AIR INTO THE AREA. PRECIPITATION WILL BE ALL
RAIN ON TUESDAY...AS TEMPERATURES RISE INTO THE LOWER 50S BY THE
AFTERNOON. THE COOL DOWN IS FORECAST TO BEGIN EARLY WEDNESDAY
MORNING...AS WINDS SHIFT FROM SOUTHERLY TO WESTERLY. SOME SNOW MAY
MIX IN WITH THE RAIN WEDNESDAY MORNING AS TEMPERATURES WILL HAVE
BOTTOMED OUT IN THE LOW TO MID 30S. THE PRECIPITATION CHANCES ARE
EXPECTED TO LAST THROUGH FRIDAY AFTERNOON...AS A SERIES OF SHORT
WAVES ROTATE AROUND THE PERIPHERY OF A LARGER SCALE UPPER TROUGH THAT
WILL BE SLOWLY SPINNING ITS WAY ACROSS THE GREAT LAKES AND SOUTHERN
NEW ENGLAND FROM MID WEEK ONWARD. THERE ARE TWO ISSUES THESE WEATHER
SYSTEMS WILL FACE AS THEY MOVE EAST...A LACK OF GOOD MOISTURE FEED
AND WEAK LIFT. WITH WINDS EXPECTED TO REMAIN PRETTY MUCH DUE WEST
THROUGH THE PERIODS WITH PRECIPITATION CHANCES...UPSLOPE LIFT WOULD
BE WEAK AT BEST. THE FORECAST TIME HEIGHTS AND SOUNDINGS ALSO SUPPORT
THIS SCENARIO. FROM EARLY WEDNESDAY ONWARD...THERE WILL BE A CHANCE
OF EITHER A RAIN SNOW MIX DURING THE MORNING AND OVERNIGHT
PERIODS...AND ALL SNOW SHOWERS THURSDAY NIGHT AND MOST OF FRIDAY. THE
COLDEST AIR ASSOCIATED WITH OUR WEATHER MAKERS IN THE EXTENDED WILL
FILTER INTO THE AREA TO END THE WEEK. DUE TO THE REINTRODUCTION OF
ABOVE FREEZING TEMPERATURES DURING THE DAY TIME PERIODS EXCEPT FOR
FRIDAY...AND THE ISOLATED NATURE OF THE SNOW SHOWERS THURSDAY NIGHT
AND FRIDAY...SNOW ACCUMULATIONS WILL BE LEFT OUT OF THE FORECAST FOR
NOW.
TEMPERATURES DURING THE PERIOD WILL FLUCTUATE A BIT...WITH WELL ABOVE
NORMAL READINGS EXPECTED THE FIRST COUPLE OF DAYS OF THE PERIOD...AND
BELOW NORMAL READINGS FROM WEDNESDAY ONWARD. DECIDED TO DECREASE
THE DAYTIME HIGHS THE MODEL BLEND GAVE ME THROUGHOUT THE PERIOD BY A
DEGREE OR TWO EACH DAY...ACCOUNTING FOR CLOUD COVER AND PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 125 AM EST SUN JAN 18 2015
VFR CONDITIONS WILL HOLD ON FOR ABOUT 3 HOURS FOR MOST OF THE
AREA...BEFORE LOWERING CEILINGS AND A BAND OF RAIN ASSOCIATED WITH A
COLD FRONT MOVES INTO THE AREA BETWEEN 9Z AND 15Z. CEILINGS WILL LOWER
TO MVFR AT LEAST BRIEFLY IN THIS BAND AND FOR A TIME BEHIND THE
FRONT...CIGS SHOULD THEN IMPROVE BACK TO MVFR OR NEAR THE MVFR/VFR
BREAK. WINDS WILL BE STRONGEST INITIALLY AT SME...SYM AND SJS...WITH
LOZ AND JKL INCREASING ALONG THE BAND OF SHOWERS. THE WINDS WILL
SWITCH TO THE WEST BEHIND THE FRONT AND WILL BE MORE UNIFORM AT 10 TO
15 KTS INTO THE DAY SUNDAY WITH CIG GRADUALLY IMPROVING TO VFR IN ALL
AREAS BY THE END OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...SBH
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
302 PM EST SUN JAN 18 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE ATLANTIC COAST THIS EVENING. HIGH
PRESSURE WILL BUILD INTO THE REGION MONDAY AND TUESDAY...WHILE A
COUPLE OF UPPER LEVEL LOW PRESSURE WAVES APPROACH THE AREA FROM
THE UPPER MIDWEST...THE FIRST MOVING OVER THE REGION DURING THE
MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SFC LOPRES OFF WAL TAFTN. ITS CHUGGING NEWD AS CDFNT ENTERS SHEN
VLY/I-81. AXIS OF MDL RAFL ASSOCD W/ LLJ MAINLY OVER THE DELMARVA
ALTHO BACK EDGE MAY BE CLIPPING THE ERN SIDE OF THE BAY. ON THE
WHOLE...PCPN FM IT OVER. WL BE TURNING ATTN TO WELL DEFINED VORT
AXIS/SFC CDFNT FOR AFTN-EVE PCPN PRODUCTION.
WHILE THE AMPLITUDE/INTENSITY OF THE PVA SUGGESTS THAT SCT SHOWERS
WUD BE PSBL...DRY AIR HAS DVLPD E OF THE FNT-- ENUF TO HV A DRY SLOT
WHERE CLDS SCATTERING OUT ACRS CENTRL VA. HRRR HAS BACKED AWAY FM A
SOLN WHERE A LINE OF LGT QPF WUD CROSS CWFA MID-LT AFTN AS IT
DEPICTED IN ERLR RUNS. AM STILL HESITANT TO GO COMPLETELY DRY INVOF
FNT..AND HV CHC POPS RETURNING AFTR 20Z.
MRNG LOW CLDS/PCPN HAS KEPT IT COOLER THAN PRVSLY ADVERTISED...AND
CAA SHUD BE UNDERWAY SHORTLY. THAT WUD MAKE FOR A COLUMN WHERE
SHOWERS MAY FALL AS SHSN IF VERT VELOCITIES FAST ENUF. WL BRING A
SHRASN MIX INTO THE PTMC HIGHLANDS PRIOR TO SUNSET. DONT HV THE
CONFIDENCE TO GO FURTHER EAST...ALTHO ITS NOT OUT OF THE REALM OF
PSBLTY.
ENUF COLD AIR WL REACH APLCNS FOR PTYPE TO CHG TO SHSN BY NIGHTFALL.
BEST FORCING COMES IN THE EVNG...AND MSTR LOOKS TO BE A LTL MORE
PLENTIFUL THAN PRVS RUNS. HV BUMPED UP SNW TTLS A LTL...BUT NOT ENUF
TO TRIGGER AN ADVY.
COOLING TNGT WL BE COMING FM ADVCTN...NOT RADIATION. FOR THAT
REASON...AND MAINTENANCE OF A GRADIENT...MIN-T FCST MIDPACK OR
PERHAPS A PINCH HIER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
BREEZY AND DRY IN THE POST-FRONTAL REGIME ON MONDAY. THE STRONGER
GUSTS WILL BE MORE LIMITED TO THE NRN HALF OF THE CWA...FROM THE
I-66 CORRIDOR TO THE MASON-DIXON LINE AND THE HIGHER TERRAIN OF THE
CNTRL APLCNS. THE INFLUX OF DRIER AND COLDER AIR WILL KEEP TEMPS
MODERATED IN THE U30S/L40S ACROSS THE NORTH WHERE THE WINDIER
CONDITIONS EXIST...WHILE THE SRN HALF OF THE AREA WILL SEE TEMPS
CLIMBING CLOSER TO 50F BY MID AFTN.
ANOTHER SUB-FREEZING OVERNIGHT PERIOD AS CLOUDS EXIT THE REGION
ALONG W/ THE PARENT UPPER LOW OVER NEW ENGLAND. FAST UPPER AND
NEARLY ZONAL FLOW WILL BE IN PLACE AHEAD OF THE NEXT SYSTEM. A
SERIES OF CLIPPERS AND CLIPPER-LIKE UPPER VORT PASSAGES WILL MARK
THE REMAINDER OF THE WEEK. THE FIRST WILL ARRIVE LATE TUE INTO EARLY
WED. WELL OUT AHEAD OF THE ACTUAL UPPER LEVEL FEATURE...A LONG BAND
OF MID-UPPER CLOUDS WILL BE CARRIED FROM THE UPPER MIDWEST TOWARD
THE MID-ATLC. SIMILAR DAYTIME HIGHS ON TUE...BUT MAINLY FROM THE
INCREASED CLOUD COVER OVER THE NORTH AS OPPOSED TO WINDS...THE SRN
TIER COUNTIES WILL ONCE AGAIN SEE RELATIVELY WARMER CONDITIONS NEAR
THE L50S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
WHILE A MUCH LARGER UPPER LOW CONTINUES TO ROTATE JUST NORTH OF
HUDSON BAY...SEVERAL VORT LOBES OF ENERGY WILL SWING AROUND THE
BASE OF THE LOW THROUGH THE REST OF THE CURRENT WEEK AND LIKELY
INTO EARLY NEXT WEEK. THE FIRST IN THIS SERIES OF SHORTWAVES IS
EXPECTED TO SLIDE ACROSS THE MID-ATLC DURING THE DAYTIME HRS ON
WED. THIS FEATURE WILL HAVE ITS ORIGINS IN THE NRN PACIFIC BUT
WILL BE DIRECTED QUICKLY ACROSS THE NRN TIER OF THE CONUS FROM TUE
INTO WED.
ENSEMBLES SHOW A TRACK ESSENTIALLY OVER TOP OUR AREA W/ DISCREPANCY
W/IN VARIOUS MEMBERS OF THE AMOUNT OF COLD AIR AND THE POTENTIAL
FOR ACCUMULATING SNOW. KEPT A HIGH-RANGE CHANCE POP FOR THE
DAYTIME HRS. MODEL BLENDS CONTINUE TO GIVE A MAX TEMP WELL ABOVE
FREEZING FOR THE AREA OUTSIDE THE MTNS...WHICH POINTS TO THE LACK
OF STRONG CAA...EVEN IF ENOUGH COLD AIR IS CARRIED W/IN THE
FEATURE TO DEVELOP SNOW SHOWERS. ACCUMULATING SNOWS MOST
CONFIDENTLY WILL BE IN THE HIGHER TERRAIN FROM START-TO-FINISH W/
LOWER CONFIDENCE EAST OF THE APLCNS. PERIODS OF SNOW OR A
RAIN/SNOW MIX LOOK POSSIBLE FOR MUCH OF THE AREA BUT IT APPEARS
THE LOW WILL HAVE TO MOVE OFF THE COAST BEFORE A MORE ORGANIZED
PRECIP SHIELD DEVELOPS.
ANOTHER COUPLE OF WEAKER BUT CLOSER-TOGETHER UPPER VORTS WILL BE
RIGHT BEHIND THE WED CLIPPER. EACH WILL LACK MOISTURE OUTSIDE OF
THE BOUNDARY LAYER CLOUD DECK THAT COULD BRING MORE SNOWS TO THE
MTNS W/ UPSLOPE EFFECTS ON THU AND AGAIN ON FRI. WEAK IN-SITU HIGH
PRESSURE IN BETWEEN UPPER WAVES AND INTO THE WEEKEND...BRINGING
CONDITIONS BACK TOWARD AVG FOR THIS TIME OF YEAR.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
CDFNT APPROACHING THE TERMINALS...AND SHUD BE THRU BY 21Z. VFR
POST-FROPA...AOB IFR AHD OF IT DUE TO LOW CLDS AND VSBYS. OUTSIDE
CHC OF A BRIEF SHRA THRU 00Z. LOW CONFIDENCE AND LMTD AREAL CVRG
PRECLUDE A TAF MENTION. ONCE TROF AXIS PASSES...CIGS WL LIFT AND
CLDS DSPT.
WINDS WL BE NWLY TNGT...BUT THEY WONT PICK UP TIL MIDDAY MON...W/
GUSTS 20-25KT LKLY AT THAT TIME. THE WIND FIELD WILL GRADUALLY
WEAKEN TOWARD SUNSET W/ A GOOD STRETCH OF LIGHT WINDS INTO MID
WEEK. A COUPLE OF CLIPPER SYSTEMS EXPECTED TO SLIDE OVER THE
AREA. ONE MID WEEK AND ANOTHER TOWARD THE END OF THE WORK WEEK.
EACH ONE POTENTIALLY BRINGING A WINTRY MIX.
&&
.MARINE...
CDFNT WL CROSS WATERS BY 00Z. NW WINDS WL PICK AFTR FROPA. WL KEEP
SCA IN EFFECT TNGT FOR 20 KT GUSTS.
GUSTS INCREASE MON MRNG ACROSS THE WATERS AND SOLID SCA CONDITIONS
OVER THE AREA WELL INTO THE AFTN...SHOULD SUBSIDE GRADUALLY TOWARD
THE EVE HRS. LIGHT WINDS INTO THE MIDDLE OF THE WEEK W/ HIGH
PRESSURE MOVING ACROSS THE AREA. A CLIPPER SYSTEM WILL SWING THRU
ON WED...POTENTIALLY BRINGING SOME RAIN/SNOW TO THE AREA.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 PM EST MONDAY
FOR ANZ530>543.
&&
$$
SYNOPSIS...GMS
NEAR TERM...HTS
SHORT TERM...GMS
LONG TERM...CEM/GMS
AVIATION...HTS/GMS
MARINE...HTS/GMS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
648 AM EST SUN JAN 18 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TODAY. A SERIES OF WEAK
DISTURBANCES WILL KEEP UNSETTLED WEATHER IN THE AREA THROUGH THE
END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES ATTM OTHER THAN MINOR ADJUSTMENTS TO HOURLY
TEMPERATURES TO INTERPOLATE LATEST OBS WITH FORECAST VALUES OVER
THE NEXT SEVERAL HOURS. OVERALL TIMING OF INITIAL PRECIP LOOKS
CLOSE WITH PRECIP SPREADING ACROSS THE FORECAST AREA OVER THEN
NEXT COUPLE HOURS. PREV DISCUSSION FOLLOWS..
COLD FRONT CURRENTLY ALONG
THE INDIANA/OHIO BORDER WILL MOVE EAST DURING THE DAY. HAVE LEANED
HEAVILY TOWARDS HRRR FOR THE TIMING OF PRECIPITATION. MANY HIGH
RESOLUTION MODELS SHOW PRECIPITATION MARKEDLY DROPPING IN COVERAGE
BY EARLY AFTERNOON...POSSIBLY DUE TO MOISTURE TRANSPORT BEING CUT
OFF BY FEATURE DEVELOPING ALONG THE ATLANTIC COAST. EXPECT A LULL
IN PRECIPITATION BY EARLY AFTERNOON...WITH REDEVELOPMENT OF
PRECIPITATION BY LATE AFTERNOON AS COLDER AIR ALLOWS FOR LAKE
ENHANCED PRECIP TO BEGIN ANEW.
TEMPERATURES OVERNIGHT HAVE REMAINED WELL ABOVE NORMAL THANKS TO
SOUTHERLY FLOW. 00Z SYNOPTIC MODELS CANNOT SEEM TO HANDLE THIS...AND
HAVE INITIALIZED TEMPS QUITE POORLY. EVEN HI-RES MODELS LIKE THE RAP
AND HRRR ARE ALSO STRUGGLING. HAVE RELIED ON GFSLAMP TEMPERATURE
GUIDANCE TODAY...WHICH MAY BE A LITTLE TOO SLOW IN BRINGING IN
COLDER TEMPERATURES BEHIND THE COLD FRONT. CURRENT FORECAST KEEPS
DAYTIME SNOWFALL ACCUMULATION TO A HALF INCH OR LESS...PRIMARILY
ALONG THE INTERSTATE 80 CORRIDOR.
SNOW WILL CONTINUE OVERNIGHT IN THE USUAL FAVORED LOCATIONS. WHILE
BOUNDARY LAYER MOISTURE IS PLENTIFUL...MOST OF THE DENDRITIC GROWTH
ZONE WILL BE ABOVE THE MOISTURE. HAVE GONE WITH ABOUT AN INCH OF
SNOW ALONG INTERSTATE 80 AND TWO INCHES OF SNOW IN THE HIGHER
ELEVATIONS OF WV/MD...WITH LESSER AMOUNTS ELSEWHERE. WHILE OVERNIGHT
TEMPERATURES WILL BE COOLER...THEY WILL STILL BE ABOVE NORMAL FOR
THIS TIME OF YEAR...IN THE MID TO UPPER 20S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HAVE KEPT CHANCE POPS IN THE RIDGES MONDAY MORNING...WITH UP TO
ANOTHER HALF INCH OF SNOW POSSIBLE. AS FLOW TURNS MORE
WESTERLY...SNOWFALL WILL COME TO AN END. MONDAY NIGHT WILL BE
DRY...BUT MODEL SOLUTIONS BEGIN TO VARY BY TUESDAY. THERE IS SOME
AMOUNT OF AGREEMENT THAT THERE WILL BE AN UPPER LEVEL TROUGH WORKING
ACROSS THE GREAT LAKES ALONG WITH A SECOND SYSTEM ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA...BUT THE STRENGTH OF THE
SYSTEMS AND THE AMOUNT OF PHASING THAT WILL OCCUR IS DEPICTED
DIFFERENTLY BY EVERY MODEL. SINCE 12Z MODEL RUNS WERE IN BETTER
AGREEMENT WITH THE HANDLING OF THESE SYSTEMS...WILL ESSENTIALLY
LEAVE THIS PART OF THE FORECAST STATUS QUO UNTIL MODELS CAN COME
BACK INTO BETTER AGREEMENT. TEMPERATURES SHOULD GENERALLY BE AROUND
NORMAL FOR MID TO LATE JANUARY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE LONGWAVE PATTERN WILL AMPLIFY AS RIDGING CONTINUES TO BUILD
OVER THE WEST COAST THROUGH THE PERIOD. LATEST MODEL RUNS ALL CONTINUE TO SHOW
REASONABLE CONSENSUS AND GOOD CONTINUITY WITH THE GENERAL
IDEA...BUT VARY WIDELY IN DETAILS. IN ANY CASE...THE AREA WILL
REMAIN IN AN UNSETTLED WEATHER PATTERN AS MEAN TROUGHING REMAINS
IN PLACE ACROSS THE EASTERN CONUS. AT THIS TIME THE BEST CHANCE
FOR PRECIPITATION LOOKS TO BE WEDNESDAY...FRIDAY...AND
SUNDAY...WITH TEMPERATURES REMAINING RELATIVELY CLOSE TO CLIMO NORMS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
CONDITIONS WILL DETERIORATE OVER THE NEXT 2-3 HOURS AS A COLD
FRONT TRANSITIONS OVER THE AREA. LLWS WILL BE POSSIBLE AHEAD OF
THE FRONT ESPECIALLY FOR LOCATIONS WHERE SURFACE WINDS REMAIN
DECOUPLED FROM WINDS ALOFT...WITH 35-40KTS VIA MDCRS AT 2500FT.
FROPA TIMES LOOK TO BE AT THE FOLLOWING TIMES 13Z ZZV...15Z
PIT...16Z LBE. AFTER IT PASSES...ANY RAIN SHOWERS WILL MIX AND
EVENTUALLY TURN TO SNOW SHOWERS FROM WEST TO EAST. MVFR AND
OCCASIONAL IFR CONDITIONS WILL THEN PERSIST THE REMAINDER OF THE
TAF PERIOD UNTIL MONDAY MORNING WHEN THE ASSOCIATED UPPER LEVEL
DISTURBANCE IS EAST OF THE AREA.
.OUTLOOK.../SUNDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS ARE EXPECTED WITH LOW PRESSURE TUESDAY NIGHT INTO
WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
338 AM EST SUN JAN 18 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TODAY. A SERIES OF WEAK
DISTURBANCES WILL KEEP UNSETTLED WEATHER IN THE AREA THROUGH THE
END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT CURRENTLY ALONG THE INDIANA/OHIO BORDER WILL MOVE EAST
DURING THE DAY. HAVE LEANED HEAVILY TOWARDS HRRR FOR THE TIMING OF
PRECIPITATION. MANY HIGH RESOLUTION MODELS SHOW PRECIPITATION
MARKEDLY DROPPING IN COVERAGE BY EARLY AFTERNOON...POSSIBLY DUE TO
MOISTURE TRANSPORT BEING CUT OFF BY FEATURE DEVELOPING ALONG THE
ATLANTIC COAST. EXPECT A LULL IN PRECIPITATION BY EARLY
AFTERNOON...WITH REDEVELOPMENT OF PRECIPITATION BY LATE AFTERNOON AS
COLDER AIR ALLOWS FOR LAKE ENHANCED PRECIP TO BEGIN ANEW.
TEMPERATURES OVERNIGHT HAVE REMAINED WELL ABOVE NORMAL THANKS TO
SOUTHERLY FLOW. 00Z SYNOPTIC MODELS CANNOT SEEM TO HANDLE THIS...AND
HAVE INITIALIZED TEMPS QUITE POORLY. EVEN HI-RES MODELS LIKE THE RAP
AND HRRR ARE ALSO STRUGGLING. HAVE RELIED ON GFSLAMP TEMPERATURE
GUIDANCE TODAY...WHICH MAY BE A LITTLE TOO SLOW IN BRINGING IN
COLDER TEMPERATURES BEHIND THE COLD FRONT. CURRENT FORECAST KEEPS
DAYTIME SNOWFALL ACCUMULATION TO A HALF INCH OR LESS...PRIMARILY
ALONG THE INTERSTATE 80 CORRIDOR.
SNOW WILL CONTINUE OVERNIGHT IN THE USUAL FAVORED LOCATIONS. WHILE
BOUNDARY LAYER MOISTURE IS PLENTIFUL...MOST OF THE DENDRITIC GROWTH
ZONE WILL BE ABOVE THE MOISTURE. HAVE GONE WITH ABOUT AN INCH OF
SNOW ALONG INTERSTATE 80 AND TWO INCHES OF SNOW IN THE HIGHER
ELEVATIONS OF WV/MD...WITH LESSER AMOUNTS ELSEWHERE. WHILE OVERNIGHT
TEMPERATURES WILL BE COOLER...THEY WILL STILL BE ABOVE NORMAL FOR
THIS TIME OF YEAR...IN THE MID TO UPPER 20S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HAVE KEPT CHANCE POPS IN THE RIDGES MONDAY MORNING...WITH UP TO
ANOTHER HALF INCH OF SNOW POSSIBLE. AS FLOW TURNS MORE
WESTERLY...SNOWFALL WILL COME TO AN END. MONDAY NIGHT WILL BE
DRY...BUT MODEL SOLUTIONS BEGIN TO VARY BY TUESDAY. THERE IS SOME
AMOUNT OF AGREEMENT THAT THERE WILL BE AN UPPER LEVEL TROUGH WORKING
ACROSS THE GREAT LAKES ALONG WITH A SECOND SYSTEM ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA...BUT THE STRENGTH OF THE
SYSTEMS AND THE AMOUNT OF PHASING THAT WILL OCCUR IS DEPICTED
DIFFERENTLY BY EVERY MODEL. SINCE 12Z MODEL RUNS WERE IN BETTER
AGREEMENT WITH THE HANDLING OF THESE SYSTEMS...WILL ESSENTIALLY
LEAVE THIS PART OF THE FORECAST STATUS QUO UNTIL MODELS CAN COME
BACK INTO BETTER AGREEMENT. TEMPERATURES SHOULD GENERALLY BE AROUND
NORMAL FOR MID TO LATE JANUARY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE LONGWAVE PATTERN WILL AMPLIFY AS RIDGING CONTINUES TO BUILD
OVER THE WEST COAST THROUGH THE PERIOD. LATEST MODEL RUNS ALL CONTINUE TO SHOW
REASONABLE CONSENSUS AND GOOD CONTINUITY WITH THE GENERAL
IDEA...BUT VARY WIDELY IN DETAILS. IN ANY CASE...THE AREA WILL
REMAIN IN AN UNSETTLED WEATHER PATTERN AS MEAN TROUGHING REMAINS
IN PLACE ACROSS THE EASTERN CONUS. AT THIS TIME THE BEST CHANCE
FOR PRECIPITATION LOOKS TO BE WEDNESDAY...FRIDAY...AND
SUNDAY...WITH TEMPERATURES REMAINING RELATIVELY CLOSE TO CLIMO NORMS.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
CONDITIONS WILL DETERIORATE OVERNITE AS A COLD FRONT CURRENTLY
OVER CENTRAL INDIANA CONTINUES TO APPROACH FROM THE WEST. STRONG
WINDS ALOFT ARE ALREADY IN PLACE AND LLWS CONDITIONS WILL BE
POSSIBLE AHEAD OF THE FRONT WHERE SFC WINDS HAVE DECOUPLED FROM
WINDS ALOFT...WITH 35-40KTS VIA MDCRS AT 2500FT AND AND
RELATIVELY LIGHT WINDS AT THE SURFACE CURRENTLY BEING OBSERVED.
THESE CONDITIONS WILL BE POSSIBLE UNTIL MID MORNING CLOSER TO
FROPA....WHICH STILL LOOKS TO BE AT THE FOLLOWING TIMES 13Z
ZZV...15Z PIT...16Z LBE. AFTER IT PASSES...ANY RAIN SHOWERS WILL
MIX AND EVENTUALLY TURN TO SNOW SHOWERS FROM WEST TO EAST.
GUIDANCE IS CLUSTERED AROUND 2-3SM FOR VIS WITH SHSN MOST OF
SUNDAY AFTERNOON AND WITH CONCURRENCE FROM GRIDDED DATASETS ROLLED
WITH CLIMO FAVORED IFR VIS AND MVFR CIGS AT MOST TERMINALS. AT
HIGHER FREQUENCY IFR SITES...FKL/DUJ/ZZV OPTED FOR IFR CIGS AS
WELL. NOW GRANTED THERE WILL BE SHORT PERIODS WHERE MVFR
CONDITIONS WILL BE OBSERVED. PCPN WINDS DOWN THE LAST FEW HOURS OF
THE FORECAST AT ZZV...WHILE AT THE REMAINDER OF THE AIRPORTS
SCATTERED RAIN/SNOW SHOWERS WILL BE AROUND AS THE UPPER LEVEL
DISTURBANCE HAS YET TO PASS THROUGH.
WINDS WILL BE GUSTY IN WAKE OF THE FRONT SUNDAY AFTERNOON WITH
SUSTAIN SPEED ECLIPSING THE CRITICAL 12KT THRESHOLD AND GUSTS
BETWEEN 2O TO 25 KTS.
.OUTLOOK.../SUNDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS ARE EXPECTED WITH LOW PRESSURE TUESDAY NIGHT INTO WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1207 PM EST SUN JAN 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EST SUN JAN 18 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
HUDSON BAY THROUGH THE WRN GREAT LAKES. A SHORTWAVE INTO NW WI
SUPPORTED LITTLE MORE THAN SOME PATCHY LIGHT SNOW OR FLURRIES IN NE
MN AND NW WI. ANOTHER UPSTREAM SHRTWV WAS LOCATED OVER NW MANITOBA.
AT THE SFC...A 995 MB TROUGH EXTENDED FROM JAMES BAY TO THE THE E
END OF LAKE SUPERIOR. A COLD FRONT STRETCHED FROM THE S END OF JAMES
BAY THROUGH NRN ONTARIO TO SRN MANITOBA. WITH NW FLOW...LINGERING
DEEP MOISTURE AND CAA BRINGING IN ONLY MODERATELY COLD AIR (850 MB
TEMPS TO NEAR -11C) ONLY WEAK LES OR FLURRIES HAVE DEVELOPED
OVERNIGHT.
WITH ONLY MARGINAL INSTABILITY...EXPECT ONLY SCT -SHSN INTO THIS
AFTERNOON WITH LIGHT ACCUMULATIONS OF AN INCH OR LESS FOR NW FLOW
FAVORED LOCATIONS. ADDITIONAL CAA BEHIND THE COLD FRONT SHIT AFTERNOON
DROPPING 850 MB TEMPS TO AROUND -14C ALONG WITH WEAK FORCING ASSOCIATED
WITH THE MANITOBA SHRTWV MAY BOOST THE LES. THE HIGHER RES MODELS
SUGGEST THAT LOW LEVEL CONV INTO WRN UPPER MI FROM IWD TOWARD ONTONAGON
BY MID TO LATE AFTERNOON COULD BRING AN INCREASE IN SHSN WITH BEST
CHANCE FOR AN INCH OR TWO OF ACCUMULATION.
TONIGHT...AS HIGH PRES BUILDS INTO THE AREA...THE LOW LEVEL WIND
BACKING TREND WITH INCREASINGLY ACYC FLOW AND INVERSION HEIGHTS
DROPPING TO AROUND 3K FT SHOULD ALLOW THE LES TO DIMINISH. THE
REMAINING SCT LIGHT SHSN SHOULD MOVE OFFSHORE FROM IWD AND SHIFT INTO
N CNTRL UPPER MI. HOWEVER...ANY ACCCUMULATIONS WILL REMAIN LIGHT...AT
OR BELOW AN INCH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 420 AM EST SUN JAN 18 2015
A SERIES OF CLIPPER SYSTEMS WILL DROP SOUTHEAST ACROSS THE REGION
DURING THE LONG TERM PERIOD AND PRODUCE PERIODS OF GENERALLY LIGHT
SNOW. BETWEEN THESE SYSTEMS THERE MAY BE A FEW LAKE ENHANCED CLOUDS
OR SNOW...BUT 850MB TEMPS DON/T REALLY BECOME FAVORABLE FOR LAKE
EFFECT UNTIL WEDNESDAY NIGHT THROUGH THURSDAY NIGHT WHEN 850MB
TEMPERATURES FALL TO THE MIDDLE TEENS BELOW ZERO.
OVERALL...TEMPERATURES WILL END UP AROUND NORMAL THROUGH THE PERIOD
AS MOST DAYS WILL BE SLIGHTLY ABOVE/BELOW NORMAL.
STARTING OFF MONDAY MORNING...THE AREA WILL UNDER THE SOUTHERN EDGE
OF A RIDGE FROM A HIGH NEAR HUDSON BAY. THE SUBSIDENCE ASSOCIATED
WITH THIS RIDGE WILL REALLY LOWER INVERSION HEIGHTS TONIGHT AND THEY
WILL ONLY BE AROUND 2-3KFT MONDAY MORNING. BUT WITH 925MB TEMPS
AROUND -15C AND MODELS SHOWING PLENTY OF LOW LEVEL MOISTURE...WOULD
EXPECT LAKE CLOUDS TO BE PRESENT. BASED OFF THE SFC-925MB WINDS
(NORTHERLY BUT VEERING OVER THE WEST)...THINK THE CLOUDS WILL BE
FOCUSED OVER THE NORTHERN HALF OF THE CWA AND ESPECIALLY OVER THE
UPSLOPE AREAS OF NORTH CENTRAL UPPER MICHIGAN. ALTHOUGH WINDS DO
VEER THROUGH THE DAY...DON/T EXPECT MUCH CLEARING WITH THE AMOUNT OF
MOISTURE BELOW THE INVERSION...SO WILL FOCUS ON MOSTLY CLOUDY SKIES
FOR MUCH OF THE AREA...WITH THE BEST OPPORTUNITY FOR A FEW PEEKS OF
SUN BEING OVER THE SOUTHERN HALF OF THE U.P. IN THE MORNING.
THE FIRST CLIPPER SYSTEM TO AFFECT THE AREA DURING THE LONG TERM
WILL BE MOVING OUT OF EASTERN NORTH DAKOTA EARLY MONDAY AFTERNOON
AND MOVE SOUTHEAST THROUGH MINNESOTA AND INTO SOUTHERN WISCONSIN AND
SOUTHERN LAKE MICHIGAN BY 18Z TUESDAY. MODELS STILL DIFFER ON THE
EXACT LOCATION OF THE BROAD AND GENERALLY WEAK MID LEVEL WARM AIR
ADVECTION MOVING ACROSS THE AREA MONDAY NIGHT INTO TUESDAY
MORNING...LARGELY TIED TO THE POTENTIAL PHASING OF TWO SHORTWAVES
EITHER OVER THE AREA OR EAST OF THE AREA. THE NORTHERN SOLUTIONS
(00Z NAM AND 12Z ECMWF) PHASE THE WAVES JUST TO THE WEST OF THE CWA
AND TRACK MUCH OF THE PRECIPITATION ACROSS UPPER MICHIGAN AND LAKE
SUPERIOR. MEANWHILE...THE 00Z GEM/GFS/ECMWF TRACK THE PRECIP ACROSS
NORTHERN WISCONSIN AND FAR SOUTHERN UPPER MICHIGAN DUE TO THE
SHORTWAVES PHASING DOWNSTREAM OF THE AREA. 12Z ECMWF ENSEMBLES
APPEAR TO BE SPLIT ON THE TWO SOLUTIONS...WHICH LIMITS CONFIDENCE IN
THE FORECAST BUT DID TREND TOWARDS THE SOUTHERN SOLUTION WITH IT/S
GROWING NUMBER OF MEMBERS. THUS...FOCUSED THE HIGHEST POPS ALONG THE
WISCONSIN BORDER AND WILL KEEP SNOWFALL AMOUNTS MAINLY UNDER AN
INCH.
BEHIND THE LOW AND SHORTWAVES...WEAK UPPER RIDGING MOVES OVER THE
AREA AND DRIES OUT THE MID LEVELS. STILL APPEARS THAT THERE WILL BE
SOME LINGERING MOISTURE IN THE LOWER LEVELS...BUT WITH 900-850MB
TEMPS ONLY AROUND -10C THERE SHOULDN/T BE MUCH IN THE WAY OF LAKE
HELP. ESPECIALLY WITH GENERALLY LIGHT NORTHERLY FLOW. WILL KEEP
CLOUDS FOCUSED IN THE NORTHERLY WIND AREA TUESDAY AFTERNOON INTO
TUESDAY NIGHT BUT WON/T SHOW MUCH MORE THAN LOW CHANCE POPS FOR THE
FAVORED UPSLOPE AREAS.
ANOTHER WEAK SURFACE TROUGH AND SHORTWAVE WILL BRUSH THE AREA LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING. DON/T EXPECT MUCH IN THE WAY
OF SNOW OTHER THAN A QUICK DUSTING OR SOME FLURRIES. BEHIND THIS
TROUGH...IT DOES APPEAR THAT COLDER AIR WILL WORK INTO THE AREA
UNDER NORTHWEST WINDS BUT INVERSION HEIGHTS ARE ONLY AROUND 4KFT.
THUS...WOULD EXPECT SOME LAKE EFFECT...BUT ACCUMULATIONS WILL BE ON
THE LIGHT SIDE. THE ONLY POSITIVE IS MUCH OF THE CLOUD BEING AROUND
OR WITHIN THE DGZ...WHICH SHOULD LEAD TO FLUFFIER SNOW BUT LIMIT
IMPACT. THIS LIGHT AND FLUFFY LAKE EFFECT SNOW WILL CONTINUE INTO
THURSDAY NIGHT BEFORE DIMINISHING.
THE NEXT SHORTWAVE IN THIS SERIES ARRIVES LATE FRIDAY AFTERNOON AND
FRIDAY NIGHT FROM THE NORTHWEST. THUS...HAVE SPREAD ANOTHER PERIOD
OF SNOW ACROSS THE AREA. WHILE IT IS STILL SEVERAL DAYS OUT...IT
APPEARS THAT THIS WAVE COULD PRODUCE A QUICK INCH OF SNOW ACROSS THE
UPPER GREAT LAKES REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1207 PM EST SUN JAN 18 2015
MAINLY MVFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD AS
LOW LEVEL MOISTURE LINGERS OVER THE AREA. LIGHT LAKE EFFECT SNOW IS
ALSO POSSIBLE AT CMX THIS MORNING AND AT IWD AND SAW LATE TODAY AND
THIS EVENING AS WINDS VEER TO THE NORTH. IWD HAS THE BEST CHANCE OF
SEEING A PERIOD OF IFR VSBY WITH SNOW SHOWERS AS THE TROUGH/FRONT
MOVES THROUGH. OTHERWISE...VSBY IS NOT EXPECTED TO DROP BELOW MVFR
AT CMX AND SAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EST SUN JAN 18 2015
NORTHWEST WINDS TO 30 KNOTS TODAY IN THE TIGHT GRADIENT BEHIND A LOW
OVER NRN ONTARIO...WILL DIMINISH TONIGHT AS HIGH PRES BUILDS INTO
THE AREA. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW 30 KNOTS
FOR THE REST OF THE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
655 AM EST SUN JAN 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EST SUN JAN 18 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
HUDSON BAY THROUGH THE WRN GREAT LAKES. A SHORTWAVE INTO NW WI
SUPPORTED LITTLE MORE THAN SOME PATCHY LIGHT SNOW OR FLURRIES IN NE
MN AND NW WI. ANOTHER UPSTREAM SHRTWV WAS LOCATED OVER NW MANITOBA.
AT THE SFC...A 995 MB TROUGH EXTENDED FROM JAMES BAY TO THE THE E
END OF LAKE SUPERIOR. A COLD FRONT STRETCHED FROM THE S END OF JAMES
BAY THROUGH NRN ONTARIO TO SRN MANITOBA. WITH NW FLOW...LINGERING
DEEP MOISTURE AND CAA BRINGING IN ONLY MODERATELY COLD AIR (850 MB
TEMPS TO NEAR -11C) ONLY WEAK LES OR FLURRIES HAVE DEVELOPED
OVERNIGHT.
WITH ONLY MARGINAL INSTABILITY...EXPECT ONLY SCT -SHSN INTO THIS
AFTERNOON WITH LIGHT ACCUMULATIONS OF AN INCH OR LESS FOR NW FLOW
FAVORED LOCATIONS. ADDITIONAL CAA BEHIND THE COLD FRONT SHIT AFTERNOON
DROPPING 850 MB TEMPS TO AROUND -14C ALONG WITH WEAK FORCING ASSOCIATED
WITH THE MANITOBA SHRTWV MAY BOOST THE LES. THE HIGHER RES MODELS
SUGGEST THAT LOW LEVEL CONV INTO WRN UPPER MI FROM IWD TOWARD ONTONAGON
BY MID TO LATE AFTERNOON COULD BRING AN INCREASE IN SHSN WITH BEST
CHANCE FOR AN INCH OR TWO OF ACCUMULATION.
TONIGHT...AS HIGH PRES BUILDS INTO THE AREA...THE LOW LEVEL WIND
BACKING TREND WITH INCREASINGLY ACYC FLOW AND INVERSION HEIGHTS
DROPPING TO AROUND 3K FT SHOULD ALLOW THE LES TO DIMINISH. THE
REMAINING SCT LIGHT SHSN SHOULD MOVE OFFSHORE FROM IWD AND SHIFT INTO
N CNTRL UPPER MI. HOWEVER...ANY ACCCUMULATIONS WILL REMAIN LIGHT...AT
OR BELOW AN INCH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 420 AM EST SUN JAN 18 2015
A SERIES OF CLIPPER SYSTEMS WILL DROP SOUTHEAST ACROSS THE REGION
DURING THE LONG TERM PERIOD AND PRODUCE PERIODS OF GENERALLY LIGHT
SNOW. BETWEEN THESE SYSTEMS THERE MAY BE A FEW LAKE ENHANCED CLOUDS
OR SNOW...BUT 850MB TEMPS DON/T REALLY BECOME FAVORABLE FOR LAKE
EFFECT UNTIL WEDNESDAY NIGHT THROUGH THURSDAY NIGHT WHEN 850MB
TEMPERATURES FALL TO THE MIDDLE TEENS BELOW ZERO.
OVERALL...TEMPERATURES WILL END UP AROUND NORMAL THROUGH THE PERIOD
AS MOST DAYS WILL BE SLIGHTLY ABOVE/BELOW NORMAL.
STARTING OFF MONDAY MORNING...THE AREA WILL UNDER THE SOUTHERN EDGE
OF A RIDGE FROM A HIGH NEAR HUDSON BAY. THE SUBSIDENCE ASSOCIATED
WITH THIS RIDGE WILL REALLY LOWER INVERSION HEIGHTS TONIGHT AND THEY
WILL ONLY BE AROUND 2-3KFT MONDAY MORNING. BUT WITH 925MB TEMPS
AROUND -15C AND MODELS SHOWING PLENTY OF LOW LEVEL MOISTURE...WOULD
EXPECT LAKE CLOUDS TO BE PRESENT. BASED OFF THE SFC-925MB WINDS
(NORTHERLY BUT VEERING OVER THE WEST)...THINK THE CLOUDS WILL BE
FOCUSED OVER THE NORTHERN HALF OF THE CWA AND ESPECIALLY OVER THE
UPSLOPE AREAS OF NORTH CENTRAL UPPER MICHIGAN. ALTHOUGH WINDS DO
VEER THROUGH THE DAY...DON/T EXPECT MUCH CLEARING WITH THE AMOUNT OF
MOISTURE BELOW THE INVERSION...SO WILL FOCUS ON MOSTLY CLOUDY SKIES
FOR MUCH OF THE AREA...WITH THE BEST OPPORTUNITY FOR A FEW PEEKS OF
SUN BEING OVER THE SOUTHERN HALF OF THE U.P. IN THE MORNING.
THE FIRST CLIPPER SYSTEM TO AFFECT THE AREA DURING THE LONG TERM
WILL BE MOVING OUT OF EASTERN NORTH DAKOTA EARLY MONDAY AFTERNOON
AND MOVE SOUTHEAST THROUGH MINNESOTA AND INTO SOUTHERN WISCONSIN AND
SOUTHERN LAKE MICHIGAN BY 18Z TUESDAY. MODELS STILL DIFFER ON THE
EXACT LOCATION OF THE BROAD AND GENERALLY WEAK MID LEVEL WARM AIR
ADVECTION MOVING ACROSS THE AREA MONDAY NIGHT INTO TUESDAY
MORNING...LARGELY TIED TO THE POTENTIAL PHASING OF TWO SHORTWAVES
EITHER OVER THE AREA OR EAST OF THE AREA. THE NORTHERN SOLUTIONS
(00Z NAM AND 12Z ECMWF) PHASE THE WAVES JUST TO THE WEST OF THE CWA
AND TRACK MUCH OF THE PRECIPITATION ACROSS UPPER MICHIGAN AND LAKE
SUPERIOR. MEANWHILE...THE 00Z GEM/GFS/ECMWF TRACK THE PRECIP ACROSS
NORTHERN WISCONSIN AND FAR SOUTHERN UPPER MICHIGAN DUE TO THE
SHORTWAVES PHASING DOWNSTREAM OF THE AREA. 12Z ECMWF ENSEMBLES
APPEAR TO BE SPLIT ON THE TWO SOLUTIONS...WHICH LIMITS CONFIDENCE IN
THE FORECAST BUT DID TREND TOWARDS THE SOUTHERN SOLUTION WITH IT/S
GROWING NUMBER OF MEMBERS. THUS...FOCUSED THE HIGHEST POPS ALONG THE
WISCONSIN BORDER AND WILL KEEP SNOWFALL AMOUNTS MAINLY UNDER AN
INCH.
BEHIND THE LOW AND SHORTWAVES...WEAK UPPER RIDGING MOVES OVER THE
AREA AND DRIES OUT THE MID LEVELS. STILL APPEARS THAT THERE WILL BE
SOME LINGERING MOISTURE IN THE LOWER LEVELS...BUT WITH 900-850MB
TEMPS ONLY AROUND -10C THERE SHOULDN/T BE MUCH IN THE WAY OF LAKE
HELP. ESPECIALLY WITH GENERALLY LIGHT NORTHERLY FLOW. WILL KEEP
CLOUDS FOCUSED IN THE NORTHERLY WIND AREA TUESDAY AFTERNOON INTO
TUESDAY NIGHT BUT WON/T SHOW MUCH MORE THAN LOW CHANCE POPS FOR THE
FAVORED UPSLOPE AREAS.
ANOTHER WEAK SURFACE TROUGH AND SHORTWAVE WILL BRUSH THE AREA LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING. DON/T EXPECT MUCH IN THE WAY
OF SNOW OTHER THAN A QUICK DUSTING OR SOME FLURRIES. BEHIND THIS
TROUGH...IT DOES APPEAR THAT COLDER AIR WILL WORK INTO THE AREA
UNDER NORTHWEST WINDS BUT INVERSION HEIGHTS ARE ONLY AROUND 4KFT.
THUS...WOULD EXPECT SOME LAKE EFFECT...BUT ACCUMULATIONS WILL BE ON
THE LIGHT SIDE. THE ONLY POSITIVE IS MUCH OF THE CLOUD BEING AROUND
OR WITHIN THE DGZ...WHICH SHOULD LEAD TO FLUFFIER SNOW BUT LIMIT
IMPACT. THIS LIGHT AND FLUFFY LAKE EFFECT SNOW WILL CONTINUE INTO
THURSDAY NIGHT BEFORE DIMINISHING.
THE NEXT SHORTWAVE IN THIS SERIES ARRIVES LATE FRIDAY AFTERNOON AND
FRIDAY NIGHT FROM THE NORTHWEST. THUS...HAVE SPREAD ANOTHER PERIOD
OF SNOW ACROSS THE AREA. WHILE IT IS STILL SEVERAL DAYS OUT...IT
APPEARS THAT THIS WAVE COULD PRODUCE A QUICK INCH OF SNOW ACROSS THE
UPPER GREAT LAKES REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 655 AM EST SUN JAN 18 2015
MAINLY MVFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD AS
LOW LEVEL MOISTURE LINGERS OVER THE AREA. LIGHT LAKE EFFECT SNOW IS
ALSO POSSIBLE AT CMX THIS MORNING AND AT IWD AND SAW LATE TODAY AND
THIS EVENING AS WINDS VEER TO THE NORTH. IWD HAS THE BEST CHANCE OF
SEEING A PERIOD OF IFR VSBY WITH SNOW SHOWERS AS THE TROUGH/FRONT
MOVES THROUGH. OTHERWISE...VSBY IS NOT EXPECTED TO DROP BELOW MVFR
AT CMX AND SAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EST SUN JAN 18 2015
NORTHWEST WINDS TO 30 KNOTS TODAY IN THE TIGHT GRADIENT BEHIND A LOW
OVER NRN ONTARIO...WILL DIMINISH TONIGHT AS HIGH PRES BUILDS INTO
THE AREA. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW 30 KNOTS
FOR THE REST OF THE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
511 AM EST SUN JAN 18 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EST SUN JAN 18 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
HUDSON BAY THROUGH THE WRN GREAT LAKES. A SHORTWAVE INTO NW WI
SUPPORTED LITTLE MORE THAN SOME PATCHY LIGHT SNOW OR FLURRIES IN NE
MN AND NW WI. ANOTHER UPSTREAM SHRTWV WAS LOCATED OVER NW MANITOBA.
AT THE SFC...A 995 MB TROUGH EXTENDED FROM JAMES BAY TO THE THE E
END OF LAKE SUPERIOR. A COLD FRONT STRETCHED FROM THE S END OF JAMES
BAY THROUGH NRN ONTARIO TO SRN MANITOBA. WITH NW FLOW...LINGERING
DEEP MOISTURE AND CAA BRINGING IN ONLY MODERATELY COLD AIR (850 MB
TEMPS TO NEAR -11C) ONLY WEAK LES OR FLURRIES HAVE DEVELOPED
OVERNIGHT.
WITH ONLY MARGINAL INSTABILITY...EXPECT ONLY SCT -SHSN INTO THIS
AFTERNOON WITH LIGHT ACCUMULATIONS OF AN INCH OR LESS FOR NW FLOW
FAVORED LOCATIONS. ADDITIONAL CAA BEHIND THE COLD FRONT SHIT AFTERNOON
DROPPING 850 MB TEMPS TO AROUND -14C ALONG WITH WEAK FORCING ASSOCIATED
WITH THE MANITOBA SHRTWV MAY BOOST THE LES. THE HIGHER RES MODELS
SUGGEST THAT LOW LEVEL CONV INTO WRN UPPER MI FROM IWD TOWARD ONTONAGON
BY MID TO LATE AFTERNOON COULD BRING AN INCREASE IN SHSN WITH BEST
CHANCE FOR AN INCH OR TWO OF ACCUMULATION.
TONIGHT...AS HIGH PRES BUILDS INTO THE AREA...THE LOW LEVEL WIND
BACKING TREND WITH INCREASINGLY ACYC FLOW AND INVERSION HEIGHTS
DROPPING TO AROUND 3K FT SHOULD ALLOW THE LES TO DIMINISH. THE
REMAINING SCT LIGHT SHSN SHOULD MOVE OFFSHORE FROM IWD AND SHIFT INTO
N CNTRL UPPER MI. HOWEVER...ANY ACCCUMULATIONS WILL REMAIN LIGHT...AT
OR BELOW AN INCH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 420 AM EST SUN JAN 18 2015
A SERIES OF CLIPPER SYSTEMS WILL DROP SOUTHEAST ACROSS THE REGION
DURING THE LONG TERM PERIOD AND PRODUCE PERIODS OF GENERALLY LIGHT
SNOW. BETWEEN THESE SYSTEMS THERE MAY BE A FEW LAKE ENHANCED CLOUDS
OR SNOW...BUT 850MB TEMPS DON/T REALLY BECOME FAVORABLE FOR LAKE
EFFECT UNTIL WEDNESDAY NIGHT THROUGH THURSDAY NIGHT WHEN 850MB
TEMPERATURES FALL TO THE MIDDLE TEENS BELOW ZERO.
OVERALL...TEMPERATURES WILL END UP AROUND NORMAL THROUGH THE PERIOD
AS MOST DAYS WILL BE SLIGHTLY ABOVE/BELOW NORMAL.
STARTING OFF MONDAY MORNING...THE AREA WILL UNDER THE SOUTHERN EDGE
OF A RIDGE FROM A HIGH NEAR HUDSON BAY. THE SUBSIDENCE ASSOCIATED
WITH THIS RIDGE WILL REALLY LOWER INVERSION HEIGHTS TONIGHT AND THEY
WILL ONLY BE AROUND 2-3KFT MONDAY MORNING. BUT WITH 925MB TEMPS
AROUND -15C AND MODELS SHOWING PLENTY OF LOW LEVEL MOISTURE...WOULD
EXPECT LAKE CLOUDS TO BE PRESENT. BASED OFF THE SFC-925MB WINDS
(NORTHERLY BUT VEERING OVER THE WEST)...THINK THE CLOUDS WILL BE
FOCUSED OVER THE NORTHERN HALF OF THE CWA AND ESPECIALLY OVER THE
UPSLOPE AREAS OF NORTH CENTRAL UPPER MICHIGAN. ALTHOUGH WINDS DO
VEER THROUGH THE DAY...DON/T EXPECT MUCH CLEARING WITH THE AMOUNT OF
MOISTURE BELOW THE INVERSION...SO WILL FOCUS ON MOSTLY CLOUDY SKIES
FOR MUCH OF THE AREA...WITH THE BEST OPPORTUNITY FOR A FEW PEEKS OF
SUN BEING OVER THE SOUTHERN HALF OF THE U.P. IN THE MORNING.
THE FIRST CLIPPER SYSTEM TO AFFECT THE AREA DURING THE LONG TERM
WILL BE MOVING OUT OF EASTERN NORTH DAKOTA EARLY MONDAY AFTERNOON
AND MOVE SOUTHEAST THROUGH MINNESOTA AND INTO SOUTHERN WISCONSIN AND
SOUTHERN LAKE MICHIGAN BY 18Z TUESDAY. MODELS STILL DIFFER ON THE
EXACT LOCATION OF THE BROAD AND GENERALLY WEAK MID LEVEL WARM AIR
ADVECTION MOVING ACROSS THE AREA MONDAY NIGHT INTO TUESDAY
MORNING...LARGELY TIED TO THE POTENTIAL PHASING OF TWO SHORTWAVES
EITHER OVER THE AREA OR EAST OF THE AREA. THE NORTHERN SOLUTIONS
(00Z NAM AND 12Z ECMWF) PHASE THE WAVES JUST TO THE WEST OF THE CWA
AND TRACK MUCH OF THE PRECIPITATION ACROSS UPPER MICHIGAN AND LAKE
SUPERIOR. MEANWHILE...THE 00Z GEM/GFS/ECMWF TRACK THE PRECIP ACROSS
NORTHERN WISCONSIN AND FAR SOUTHERN UPPER MICHIGAN DUE TO THE
SHORTWAVES PHASING DOWNSTREAM OF THE AREA. 12Z ECMWF ENSEMBLES
APPEAR TO BE SPLIT ON THE TWO SOLUTIONS...WHICH LIMITS CONFIDENCE IN
THE FORECAST BUT DID TREND TOWARDS THE SOUTHERN SOLUTION WITH IT/S
GROWING NUMBER OF MEMBERS. THUS...FOCUSED THE HIGHEST POPS ALONG THE
WISCONSIN BORDER AND WILL KEEP SNOWFALL AMOUNTS MAINLY UNDER AN
INCH.
BEHIND THE LOW AND SHORTWAVES...WEAK UPPER RIDGING MOVES OVER THE
AREA AND DRIES OUT THE MID LEVELS. STILL APPEARS THAT THERE WILL BE
SOME LINGERING MOISTURE IN THE LOWER LEVELS...BUT WITH 900-850MB
TEMPS ONLY AROUND -10C THERE SHOULDN/T BE MUCH IN THE WAY OF LAKE
HELP. ESPECIALLY WITH GENERALLY LIGHT NORTHERLY FLOW. WILL KEEP
CLOUDS FOCUSED IN THE NORTHERLY WIND AREA TUESDAY AFTERNOON INTO
TUESDAY NIGHT BUT WON/T SHOW MUCH MORE THAN LOW CHANCE POPS FOR THE
FAVORED UPSLOPE AREAS.
ANOTHER WEAK SURFACE TROUGH AND SHORTWAVE WILL BRUSH THE AREA LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING. DON/T EXPECT MUCH IN THE WAY
OF SNOW OTHER THAN A QUICK DUSTING OR SOME FLURRIES. BEHIND THIS
TROUGH...IT DOES APPEAR THAT COLDER AIR WILL WORK INTO THE AREA
UNDER NORTHWEST WINDS BUT INVERSION HEIGHTS ARE ONLY AROUND 4KFT.
THUS...WOULD EXPECT SOME LAKE EFFECT...BUT ACCUMULATIONS WILL BE ON
THE LIGHT SIDE. THE ONLY POSITIVE IS MUCH OF THE CLOUD BEING AROUND
OR WITHIN THE DGZ...WHICH SHOULD LEAD TO FLUFFIER SNOW BUT LIMIT
IMPACT. THIS LIGHT AND FLUFFY LAKE EFFECT SNOW WILL CONTINUE INTO
THURSDAY NIGHT BEFORE DIMINISHING.
THE NEXT SHORTWAVE IN THIS SERIES ARRIVES LATE FRIDAY AFTERNOON AND
FRIDAY NIGHT FROM THE NORTHWEST. THUS...HAVE SPREAD ANOTHER PERIOD
OF SNOW ACROSS THE AREA. WHILE IT IS STILL SEVERAL DAYS OUT...IT
APPEARS THAT THIS WAVE COULD PRODUCE A QUICK INCH OF SNOW ACROSS THE
UPPER GREAT LAKES REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1235 AM EST SUN JAN 18 2015
A MOIST...CYC AND GUSTY UPSLOPE NW FLOW IN THE PRESENCE OF LINGERING
MSTR WL BRING PREDOMINANT IFR CONDITIONS TO CMX EARLY THIS MRNG AND
AT LEAST OCNL IFR WX TO IWD EVEN THOUGH THE AIRMASS IS ONLY
MARGINALLY COLD FOR LES. ALTHOUGH SOME -SHSN MAY IMPACT SAW...
DOWNSLOPE NATURE OF THE FLOW AT THIS LOCATION WL RESULT IN MVFR
CONDITIONS THERE. WITH SOME DRYING ALOFT LATER ON...CONDITIONS WL
TEND TO IMPROVE TOWARD 12Z. MVFR CONDITIONS WL THEN PREVAIL INTO THE
AFTN...WHEN A COLD FNT WL SWING ACRS UPR MI. WITH A WSHFT TO AN
UPSLOPE N DIRECTION BEHIND THE FNT...IWD AND PERHAPS SAW WL SEE AT
LEAST A BRIEF PERIOD OF IFR CONDITIONS. BUT RATHER STEADY DRYING
DURING THE EVNG WL TEND TO DIMINISH THE SHSN AND BRING A RETURN TO
MVFR WX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EST SUN JAN 18 2015
NORTHWEST WINDS TO 30 KNOTS TODAY IN THE TIGHT GRADIENT BEHIND A LOW
OVER NRN ONTARIO...WILL DIMINISH TONIGHT AS HIGH PRES BUILDS INTO
THE AREA. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW 30 KNOTS
FOR THE REST OF THE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
1207 PM CST SUN JAN 18 2015
.UPDATE...
ISSUED AT 1205 AM CST SUN JAN 18 2015
UPDATED FOR AVIATION DISCUSSION ISSUED BELOW
UPDATE ISSUED AT 938 AM CST SUN JAN 18 2015
A BAND OF SNOW HAS MOVED OVER THE ARROWHEAD THANKS TO A VORT MAX
CROSSING THROUGH. COOLING CLOUD TOPS NOTED ON SATELLITE SHOULD
RESULT IN SOME MODERATE BANDS AS WELL WITH REDUCED VISIBILITIES.
MADE SOME ADJUSTMENTS.
UPDATE ISSUED AT 833 AM CST SUN JAN 18 2015
SEVERAL LOCATIONS ARE REPORTING SOME UNKNOWN PRECIPITATION OVER
NORTHERN MN. HAVE ADDED A MENTION OF PATCHY FREEZING DRIZZLE WHICH
IS SUPPORTED BY RAP FORECAST SOUNDINGS. REST OF THE FORECAST IN
THE BALLPARK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CST SUN JAN 18 2015
SCATTED BRIEF SNOW SHOWERS THIS MORNING WITH SOUTH SHORE LAKE
EFFECT THROUGH THE DAY...THEN SOME CLEARING LATE TODAY BEFORE
WIDESPREAD CHANCE FOR 1-3 INCHES OF SNOW ON MONDAY. TEMPS
MILD...AROUND 10 DEGREES ABOVE NORMAL.
ON THE SYNOPTIC SCALE...NORTHWESTERLY FLOW ACROSS THE REGION
THROUGHOUT THE COLUMN WITH A FAIRLY TYPICAL RIDGE-TROUGH PATTERN
OVER THE LOWER 48...WITH A RIDGE OVER THE NORTHERN US/CANADIAN
ROCKIES AND A TROUGH OVER THE UPPER GREAT LAKES/OHIO VALLEY. THIS
WILL CHANGE LATE SUNDAY THROUGH THE EARLY WORK WEEK AS A SERIES OF
MID-LEVEL DISTURBANCES ENTER THE PACIFIC NORTHWEST AND MOVE EAST
INTO THE NORTHERN PLAINS AND UPPER MIDWEST RESULTING IN AN ACTIVE
WEATHER PERIOD. WITH THE COMPLEXITY OF THIS UPCOMING PATTERN
CONFIDENCE IS GENERALLY LOW FOR LATE TONIGHT AND INTO MONDAY DUE TO
MODEL INCONSISTENCIES AND THE DIFFERENCES JUST A SMALL SHIFT IN A
PATTERN CAN MEAN TO THE SENSIBLE WEATHER LIKE SNOWFALL AMOUNTS.
TODAY...SCATTERED LIGHT SNOW SHOWERS ACROSS NORTHEAST MINNESOTA THIS
MORNING AND SOUTH SHORE LAKE EFFECT SNOW SHOWERS THROUGH MOST OF THE
DAY. SNOWFALL AMOUNTS WILL BE LIGHT IN BOTH LOCATIONS...WITH A
COATING TO A FEW QUICK TENTHS OF AN INCH IN NORTHERN MN AND UP TO AN
INCH OR TWO ALONG THE GOGEBIC RANGE IN NORTHERN IRON/ASHLAND
COUNTIES. LOW LEVEL LAPSE ARE FAIRLY STEEP AT LOW LEVELS...AND
EXPECT SNOW SHOWERS THIS MORNING WILL HAVE THE POTENTIAL TO BE
FAIRLY INTENSE /POSSIBLY DROPPING VISIBILITY TO A MILE AT
TIMES/...BUT THEIR SHORT DURATION WILL LIMIT ACCUMULATION.
TEMPERATURES MILD...A WEAK COLD FRONT WILL DIP SOUTH THROUGH THE
REGION THIS MORNING WHICH WILL PROVIDE THE FORCING FOR THE
AFOREMENTIONED SNOW SHOWERS IN NORTHERN MINNESOTA...SO IN MOST
PLACES HIGHS IN THE UPPER 20S TO LOW 30S WILL OCCUR IN THE MORNING
HOURS WITH TEMPERATURES GRADUALLY FALLING DURING THE AFTERNOON. MAY
SEE THE SUN BREAK LATE THIS AFTERNOON AS WEAK LOW/MID-LEVEL RIDING MOVES
IN FROM THE WEST AHEAD OF THE NEXT DISTURBANCE.
TONIGHT...INCREASING CLOUDS FROM WEST TO EAST. ALL SNOW SHOWERS WILL
END BY THE EARLY EVENING AND THINGS SHOULD REMAIN DRY THROUGHOUT THE
NIGHT. TEMPERATURES DROPPING TO MID-TEENS TO SINGLE DIGITS. CURRENT
FORECAST MAY BE A BIT TOO MILD IF CLOUD COVER IS LESS THAN CURRENTLY
ANTICIPATED.
MONDAY...A VERY COMPLEX PATTERN AT MID-LEVELS OVER THE NORTHERN
PLAINS AND UPPER MIDWEST AS H5 HEIGHTS FALL AND A LOW PRESSURE
DEVELOPS ALONG THE NORTH DAKOTA/CANADIAN BORDER. CURRENT SPREAD OF
MODEL GUIDANCE IS LARGER THAN EXPECTED AT THIS TIME RANGE...AND THUS
HAVE BELOW NORMAL CONFIDENCE FOR HOW THIS STORM WILL EVOLVE. AT THIS
POINT IT LOOKS SNOWFALL WILL BEGIN MONDAY MORNING IN NORTHEAST
MINNESOTA QUICKLY SPREADING FROM WEST TO EAST...REACHING NORTHWEST
WISCONSIN BY MID/LATE MORNING. AT THIS POINT THE BEST CHANCE FOR
SNOWFALL LOOKS TO BE FROM BEMIDJI EAST ALONG THE HIGHWAY TWO
CORRIDOR AND INTO MOST OF NORTHWEST WISCONSIN. HOWEVER...SOME OF THE
HIGHER RESOLUTION GUIDANCE PLACES THE BEST CORRIDOR FOR SNOWFALL
ALONG THE INTERNATIONAL BORDER REGION. WENT WITH A CONSERVATIVE
FORECAST FOR SNOWFALL AMOUNTS WITH 1-3 INCHES...BUT SEE POTENTIAL
FOR A SWATH OF 2-4 INCHES SOMEWHERE ACROSS THE REGION. TEMPS
RELATIVELY MILD...UPPER 20S TO LOW 30S EXCEPT FOR THE ARROWHEAD
REGION WHERE HIGHS WILL BE LIMITED TO THE LOW TO MID 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 357 AM CST SUN JAN 18 2015
PERSISTENT NW FLOW POSITIONED OVER THE UPPER MIDWEST WILL ALLOW FOR
A WAVE TRAIN OF MULTIPLE EMBEDDED SHORT WAVES TO TRANSLATE ACROSS
THE FORECAST AREA THROUGH THE EXTENDED PERIOD. EACH VORT MAX/CLIPPER
WILL BRING A QUICK SHOT FOR LIGHT SNOW AND/OR DRIZZLE...KEEPING
SMALL POPS IN NEARLY EVERY PERIOD OUT THROUGH SUNDAY.
ALTHOUGH...TIMING AND TRACK OF THESE FAST MOVING WAVES CAN BE
DIFFICULT TO PIN DOWN...AT THIS TIME LONG RANGE MODELS ARE IN
REASONABLE AGREEMENT THAT THE STRONGEST WAVE WITH AN ASSOCIATED H85
TROUGH AND SFC LOW IS ON TRACK TO BRING LIGHT SNOW ACCUMULATIONS OF
AN INCH OR TWO FRIDAY/FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1205 AM CST SUN JAN 18 2015
A COLD FRONT CURRENTLY ACROSS NORTHERN MINNESOTA WILL GRADUALLY
MAKE ITS WAY SOUTHWARD TODAY... BRINGING AN AREA OF LIGHT SNOW
SHOWERS WITH OCCASIONAL FREEZING DRIZZLE WITH IT. MVFR CIGS ARE
OCCURRING... OR EXPECTED SOON ACROSS MOST TAF SITES WITH AN
IMPROVEMENT BACK TO VFR EXPECTED GENERALLY AROUND THE 22Z TO 0Z
TIME FRAME FOR THOSE SITES. THE EXCEPTION WILL BE HYR... WITH CIGS
HOVERING AROUND THE MVFR/VRF LINE. A NEW SYSTEM WILL APPROACH FROM
THE WEST LATE TONIGHT... WHICH WILL BRING CIGS BACK DOWN TO
MVFR... WITH POSSIBLE INTERMITTENT IFR LEVELS MAINLY FROM 12Z ON.
THE SYSTEM WILL BRING A ROUND OF ACCUMULATING SNOW TO THE
NORTHLAND... WHICH MAY BRING VIS DOWN TO 3SM ON OCCASION.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 32 16 28 21 / 20 40 60 60
INL 28 8 27 15 / 20 20 40 30
BRD 31 19 33 22 / 0 30 40 40
HYR 33 16 29 20 / 10 20 60 60
ASX 35 15 27 20 / 30 20 60 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...GRANING
AVIATION...GROCHOCINSKI/MCLOVIN
AREA FORECAST DISCUSSION
NWS DULUTH MN
938 AM CST SUN JAN 18 2015
.UPDATE...
ISSUED AT 938 AM CST SUN JAN 18 2015
A BAND OF SNOW HAS MOVED OVER THE ARROWHEAD THANKS TO A VORT MAX
CROSSING THROUGH. COOLING CLOUD TOPS NOTED ON SATELLITE SHOULD
RESULT IN SOME MODERATE BANDS AS WELL WITH REDUCED VISIBILITIES.
MADE SOME ADJUSTMENTS.
UPDATE ISSUED AT 833 AM CST SUN JAN 18 2015
SEVERAL LOCATIONS ARE REPORTING SOME UNKNOWN PRECIPITATION OVER
NORTHERN MN. HAVE ADDED A MENTION OF PATCHY FREEZING DRIZZLE WHICH
IS SUPPORTED BY RAP FORECAST SOUNDINGS. REST OF THE FORECAST IN
THE BALLPARK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CST SUN JAN 18 2015
SCATTED BRIEF SNOW SHOWERS THIS MORNING WITH SOUTH SHORE LAKE
EFFECT THROUGH THE DAY...THEN SOME CLEARING LATE TODAY BEFORE
WIDESPREAD CHANCE FOR 1-3 INCHES OF SNOW ON MONDAY. TEMPS
MILD...AROUND 10 DEGREES ABOVE NORMAL.
ON THE SYNOPTIC SCALE...NORTHWESTERLY FLOW ACROSS THE REGION
THROUGHOUT THE COLUMN WITH A FAIRLY TYPICAL RIDGE-TROUGH PATTERN
OVER THE LOWER 48...WITH A RIDGE OVER THE NORTHERN US/CANADIAN
ROCKIES AND A TROUGH OVER THE UPPER GREAT LAKES/OHIO VALLEY. THIS
WILL CHANGE LATE SUNDAY THROUGH THE EARLY WORK WEEK AS A SERIES OF
MID-LEVEL DISTURBANCES ENTER THE PACIFIC NORTHWEST AND MOVE EAST
INTO THE NORTHERN PLAINS AND UPPER MIDWEST RESULTING IN AN ACTIVE
WEATHER PERIOD. WITH THE COMPLEXITY OF THIS UPCOMING PATTERN
CONFIDENCE IS GENERALLY LOW FOR LATE TONIGHT AND INTO MONDAY DUE TO
MODEL INCONSISTENCIES AND THE DIFFERENCES JUST A SMALL SHIFT IN A
PATTERN CAN MEAN TO THE SENSIBLE WEATHER LIKE SNOWFALL AMOUNTS.
TODAY...SCATTERED LIGHT SNOW SHOWERS ACROSS NORTHEAST MINNESOTA THIS
MORNING AND SOUTH SHORE LAKE EFFECT SNOW SHOWERS THROUGH MOST OF THE
DAY. SNOWFALL AMOUNTS WILL BE LIGHT IN BOTH LOCATIONS...WITH A
COATING TO A FEW QUICK TENTHS OF AN INCH IN NORTHERN MN AND UP TO AN
INCH OR TWO ALONG THE GOGEBIC RANGE IN NORTHERN IRON/ASHLAND
COUNTIES. LOW LEVEL LAPSE ARE FAIRLY STEEP AT LOW LEVELS...AND
EXPECT SNOW SHOWERS THIS MORNING WILL HAVE THE POTENTIAL TO BE
FAIRLY INTENSE /POSSIBLY DROPPING VISIBILITY TO A MILE AT
TIMES/...BUT THEIR SHORT DURATION WILL LIMIT ACCUMULATION.
TEMPERATURES MILD...A WEAK COLD FRONT WILL DIP SOUTH THROUGH THE
REGION THIS MORNING WHICH WILL PROVIDE THE FORCING FOR THE
AFOREMENTIONED SNOW SHOWERS IN NORTHERN MINNESOTA...SO IN MOST
PLACES HIGHS IN THE UPPER 20S TO LOW 30S WILL OCCUR IN THE MORNING
HOURS WITH TEMPERATURES GRADUALLY FALLING DURING THE AFTERNOON. MAY
SEE THE SUN BREAK LATE THIS AFTERNOON AS WEAK LOW/MID-LEVEL RIDING MOVES
IN FROM THE WEST AHEAD OF THE NEXT DISTURBANCE.
TONIGHT...INCREASING CLOUDS FROM WEST TO EAST. ALL SNOW SHOWERS WILL
END BY THE EARLY EVENING AND THINGS SHOULD REMAIN DRY THROUGHOUT THE
NIGHT. TEMPERATURES DROPPING TO MID-TEENS TO SINGLE DIGITS. CURRENT
FORECAST MAY BE A BIT TOO MILD IF CLOUD COVER IS LESS THAN CURRENTLY
ANTICIPATED.
MONDAY...A VERY COMPLEX PATTERN AT MID-LEVELS OVER THE NORTHERN
PLAINS AND UPPER MIDWEST AS H5 HEIGHTS FALL AND A LOW PRESSURE
DEVELOPS ALONG THE NORTH DAKOTA/CANADIAN BORDER. CURRENT SPREAD OF
MODEL GUIDANCE IS LARGER THAN EXPECTED AT THIS TIME RANGE...AND THUS
HAVE BELOW NORMAL CONFIDENCE FOR HOW THIS STORM WILL EVOLVE. AT THIS
POINT IT LOOKS SNOWFALL WILL BEGIN MONDAY MORNING IN NORTHEAST
MINNESOTA QUICKLY SPREADING FROM WEST TO EAST...REACHING NORTHWEST
WISCONSIN BY MID/LATE MORNING. AT THIS POINT THE BEST CHANCE FOR
SNOWFALL LOOKS TO BE FROM BEMIDJI EAST ALONG THE HIGHWAY TWO
CORRIDOR AND INTO MOST OF NORTHWEST WISCONSIN. HOWEVER...SOME OF THE
HIGHER RESOLUTION GUIDANCE PLACES THE BEST CORRIDOR FOR SNOWFALL
ALONG THE INTERNATIONAL BORDER REGION. WENT WITH A CONSERVATIVE
FORECAST FOR SNOWFALL AMOUNTS WITH 1-3 INCHES...BUT SEE POTENTIAL
FOR A SWATH OF 2-4 INCHES SOMEWHERE ACROSS THE REGION. TEMPS
RELATIVELY MILD...UPPER 20S TO LOW 30S EXCEPT FOR THE ARROWHEAD
REGION WHERE HIGHS WILL BE LIMITED TO THE LOW TO MID 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 357 AM CST SUN JAN 18 2015
PERSISTENT NW FLOW POSITIONED OVER THE UPPER MIDWEST WILL ALLOW FOR
A WAVE TRAIN OF MULTIPLE EMBEDDED SHORT WAVES TO TRANSLATE ACROSS
THE FORECAST AREA THROUGH THE EXTENDED PERIOD. EACH VORT MAX/CLIPPER
WILL BRING A QUICK SHOT FOR LIGHT SNOW AND/OR DRIZZLE...KEEPING
SMALL POPS IN NEARLY EVERY PERIOD OUT THROUGH SUNDAY.
ALTHOUGH...TIMING AND TRACK OF THESE FAST MOVING WAVES CAN BE
DIFFICULT TO PIN DOWN...AT THIS TIME LONG RANGE MODELS ARE IN
REASONABLE AGREEMENT THAT THE STRONGEST WAVE WITH AN ASSOCIATED H85
TROUGH AND SFC LOW IS ON TRACK TO BRING LIGHT SNOW ACCUMULATIONS OF
AN INCH OR TWO FRIDAY/FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 552 AM CST SUN JAN 18 2015
WIDESPREAD CEILINGS AROUND 4-6 KFT WITH POCKETS OF MVFR CONDITIONS
AND FLURRIES WILL PREVAIL TODAY. THE EXCEPTION WILL BE AT KBRD
WHERE VFR CONDITIONS SHOULD PREVAIL. THE LOWEST CEILINGS WITH
PERSISTENT MVFR CIGS ARE EXPECTED AT KHYR THROUGH THE TAF PERIOD.
SKIES MAY SCATTER OUT FOR A BRIEF TIME THIS EVENING FOR LOCATIONS
OVER MINNESOTA...BEFORE WINDS TURN OUT OF THE SOUTHEAST/EAST AND
LOW CLOUDS MAKE A RETURN LATE IN THE NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 32 16 28 21 / 20 40 60 60
INL 28 8 27 15 / 10 20 40 30
BRD 31 19 33 22 / 0 30 40 40
HYR 32 16 29 20 / 10 20 60 60
ASX 32 15 27 20 / 30 20 60 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...JJM
LONG TERM...GRANING
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS DULUTH MN
833 AM CST SUN JAN 18 2015
.UPDATE...
ISSUED AT 833 AM CST SUN JAN 18 2015
SEVERAL LOCATIONS ARE REPORTING SOME UNKNOWN PRECIPITATION OVER
NORTHERN MN. HAVE ADDED A MENTION OF PATCHY FREEZING DRIZZLE WHICH
IS SUPPORTED BY RAP FORECAST SOUNDINGS. REST OF THE FORECAST IN
THE BALLPARK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CST SUN JAN 18 2015
SCATTED BRIEF SNOW SHOWERS THIS MORNING WITH SOUTH SHORE LAKE
EFFECT THROUGH THE DAY...THEN SOME CLEARING LATE TODAY BEFORE
WIDESPREAD CHANCE FOR 1-3 INCHES OF SNOW ON MONDAY. TEMPS
MILD...AROUND 10 DEGREES ABOVE NORMAL.
ON THE SYNOPTIC SCALE...NORTHWESTERLY FLOW ACROSS THE REGION
THROUGHOUT THE COLUMN WITH A FAIRLY TYPICAL RIDGE-TROUGH PATTERN
OVER THE LOWER 48...WITH A RIDGE OVER THE NORTHERN US/CANADIAN
ROCKIES AND A TROUGH OVER THE UPPER GREAT LAKES/OHIO VALLEY. THIS
WILL CHANGE LATE SUNDAY THROUGH THE EARLY WORK WEEK AS A SERIES OF
MID-LEVEL DISTURBANCES ENTER THE PACIFIC NORTHWEST AND MOVE EAST
INTO THE NORTHERN PLAINS AND UPPER MIDWEST RESULTING IN AN ACTIVE
WEATHER PERIOD. WITH THE COMPLEXITY OF THIS UPCOMING PATTERN
CONFIDENCE IS GENERALLY LOW FOR LATE TONIGHT AND INTO MONDAY DUE TO
MODEL INCONSISTENCIES AND THE DIFFERENCES JUST A SMALL SHIFT IN A
PATTERN CAN MEAN TO THE SENSIBLE WEATHER LIKE SNOWFALL AMOUNTS.
TODAY...SCATTERED LIGHT SNOW SHOWERS ACROSS NORTHEAST MINNESOTA THIS
MORNING AND SOUTH SHORE LAKE EFFECT SNOW SHOWERS THROUGH MOST OF THE
DAY. SNOWFALL AMOUNTS WILL BE LIGHT IN BOTH LOCATIONS...WITH A
COATING TO A FEW QUICK TENTHS OF AN INCH IN NORTHERN MN AND UP TO AN
INCH OR TWO ALONG THE GOGEBIC RANGE IN NORTHERN IRON/ASHLAND
COUNTIES. LOW LEVEL LAPSE ARE FAIRLY STEEP AT LOW LEVELS...AND
EXPECT SNOW SHOWERS THIS MORNING WILL HAVE THE POTENTIAL TO BE
FAIRLY INTENSE /POSSIBLY DROPPING VISIBILITY TO A MILE AT
TIMES/...BUT THEIR SHORT DURATION WILL LIMIT ACCUMULATION.
TEMPERATURES MILD...A WEAK COLD FRONT WILL DIP SOUTH THROUGH THE
REGION THIS MORNING WHICH WILL PROVIDE THE FORCING FOR THE
AFOREMENTIONED SNOW SHOWERS IN NORTHERN MINNESOTA...SO IN MOST
PLACES HIGHS IN THE UPPER 20S TO LOW 30S WILL OCCUR IN THE MORNING
HOURS WITH TEMPERATURES GRADUALLY FALLING DURING THE AFTERNOON. MAY
SEE THE SUN BREAK LATE THIS AFTERNOON AS WEAK LOW/MID-LEVEL RIDING MOVES
IN FROM THE WEST AHEAD OF THE NEXT DISTURBANCE.
TONIGHT...INCREASING CLOUDS FROM WEST TO EAST. ALL SNOW SHOWERS WILL
END BY THE EARLY EVENING AND THINGS SHOULD REMAIN DRY THROUGHOUT THE
NIGHT. TEMPERATURES DROPPING TO MID-TEENS TO SINGLE DIGITS. CURRENT
FORECAST MAY BE A BIT TOO MILD IF CLOUD COVER IS LESS THAN CURRENTLY
ANTICIPATED.
MONDAY...A VERY COMPLEX PATTERN AT MID-LEVELS OVER THE NORTHERN
PLAINS AND UPPER MIDWEST AS H5 HEIGHTS FALL AND A LOW PRESSURE
DEVELOPS ALONG THE NORTH DAKOTA/CANADIAN BORDER. CURRENT SPREAD OF
MODEL GUIDANCE IS LARGER THAN EXPECTED AT THIS TIME RANGE...AND THUS
HAVE BELOW NORMAL CONFIDENCE FOR HOW THIS STORM WILL EVOLVE. AT THIS
POINT IT LOOKS SNOWFALL WILL BEGIN MONDAY MORNING IN NORTHEAST
MINNESOTA QUICKLY SPREADING FROM WEST TO EAST...REACHING NORTHWEST
WISCONSIN BY MID/LATE MORNING. AT THIS POINT THE BEST CHANCE FOR
SNOWFALL LOOKS TO BE FROM BEMIDJI EAST ALONG THE HIGHWAY TWO
CORRIDOR AND INTO MOST OF NORTHWEST WISCONSIN. HOWEVER...SOME OF THE
HIGHER RESOLUTION GUIDANCE PLACES THE BEST CORRIDOR FOR SNOWFALL
ALONG THE INTERNATIONAL BORDER REGION. WENT WITH A CONSERVATIVE
FORECAST FOR SNOWFALL AMOUNTS WITH 1-3 INCHES...BUT SEE POTENTIAL
FOR A SWATH OF 2-4 INCHES SOMEWHERE ACROSS THE REGION. TEMPS
RELATIVELY MILD...UPPER 20S TO LOW 30S EXCEPT FOR THE ARROWHEAD
REGION WHERE HIGHS WILL BE LIMITED TO THE LOW TO MID 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 357 AM CST SUN JAN 18 2015
PERSISTENT NW FLOW POSITIONED OVER THE UPPER MIDWEST WILL ALLOW FOR
A WAVE TRAIN OF MULTIPLE EMBEDDED SHORT WAVES TO TRANSLATE ACROSS
THE FORECAST AREA THROUGH THE EXTENDED PERIOD. EACH VORT MAX/CLIPPER
WILL BRING A QUICK SHOT FOR LIGHT SNOW AND/OR DRIZZLE...KEEPING
SMALL POPS IN NEARLY EVERY PERIOD OUT THROUGH SUNDAY.
ALTHOUGH...TIMING AND TRACK OF THESE FAST MOVING WAVES CAN BE
DIFFICULT TO PIN DOWN...AT THIS TIME LONG RANGE MODELS ARE IN
REASONABLE AGREEMENT THAT THE STRONGEST WAVE WITH AN ASSOCIATED H85
TROUGH AND SFC LOW IS ON TRACK TO BRING LIGHT SNOW ACCUMULATIONS OF
AN INCH OR TWO FRIDAY/FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 552 AM CST SUN JAN 18 2015
WIDESPREAD CEILINGS AROUND 4-6 KFT WITH POCKETS OF MVFR CONDITIONS
AND FLURRIES WILL PREVAIL TODAY. THE EXCEPTION WILL BE AT KBRD
WHERE VFR CONDITIONS SHOULD PREVAIL. THE LOWEST CEILINGS WITH
PERSISTENT MVFR CIGS ARE EXPECTED AT KHYR THROUGH THE TAF PERIOD.
SKIES MAY SCATTER OUT FOR A BRIEF TIME THIS EVENING FOR LOCATIONS
OVER MINNESOTA...BEFORE WINDS TURN OUT OF THE SOUTHEAST/EAST AND
LOW CLOUDS MAKE A RETURN LATE IN THE NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 32 16 28 21 / 20 40 60 60
INL 28 8 27 15 / 10 20 40 30
BRD 31 19 33 22 / 0 30 40 40
HYR 32 16 29 20 / 10 20 60 60
ASX 32 15 27 20 / 30 20 60 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...JJM
LONG TERM...GRANING
AVIATION...GRANING
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1052 AM CST Sun Jan 18 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 225 AM CST Sun Jan 18 2015
Main forecast issue today is how warm to go with temps. The weak
cold front has pushed east of the area and the core of coolest air
is already centered east of the CWA. Surface winds remain westerly
at this time and warm advection aloft has begun. All signals
currently point to raising the high temperatures. Heights aloft
will be on the rise in the wake of the departing upper trof, low
level WAA will be occuring, surface winds will have a largely
westerly component while backing slightly this afternoon, and
temps at this early morning hour are not very cold. The only
clouds should be a swath of high clouds passing west to east. Sans
the HRRR and RAP, the 2m model temps and MOS guidance has exhibited
a pretty good cool bias the last few days. The HRRR and RAP have
peformed rather well and the new forecast for today nudges highs
closer to them with another day of well above average temperatures.
Glass
.LONG TERM: (Tonight through Friday)
Issued at 225 AM CST Sun Jan 18 2015
The models depict a weak surface low migrating east-southeastward
from near Kansas City into southern Illinois tonight along a wind
shift boundary, and then lift this boundary to the east of the CWA
during the day on Monday. There has been some type of this depiction
the last few days in the models, however the placement now is further
south and leaves into question the nature of the surface wind field
on Monday and strength of warm advection. I have lowered temps
slightly as a result, but taking into account the cool bias, not
as much as MOS and they are still above average.
Another northwest flow shortwave will amplify as it moves through
the area Tuesday into Tuesday Night. There is initially a westerly
wind shift on Monday night in response, with increasing baroclinicity
and cold advection on Tuesday and Tuesday night as the heights
aloft really begin to fall. A greater number of the models are now
generating precipitation across southern MO and southern IL on
Tuesday in response to mid level convergence/frontogenesis, weak
large scale ascent, and divergence associated with the ULJ. I have
added some slight chance pops as a result, but these pops may need
to be ramped up should the current model trends persist.
Cooler temperatures, more seasonable for the later part of January,
will prevail during the later part of the week and into the
weekend however confidence in the degree of cooling is low. The
large scale pattern will once again become more amplified with an
upper ridge from the East Pacific into western North America and a
downstream longwave trof dominating a good portion of the Conus
which favors overall cooler weather. However, there is considerable
variability in the deterministic models and GEFS ensemble members
with the shortwaves moving through the longwave leading to lower
than normal predicatability.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1048 AM CST Sun Jan 18 2015
Northwest flow aloft and weak areas of low pressure will produce a
VFR forecast with light winds.
Specifics for KSTL: Some mid to high clouds and a west wind for
the early part of the forecast, then the wind becomes light and
variale late tonight. VFR through the period.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
433 AM CST Sun Jan 18 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 225 AM CST Sun Jan 18 2015
Main forecast issue today is how warm to go with temps. The weak
cold front has pushed east of the area and the core of coolest air
is already centered east of the CWA. Surface winds remain westerly
at this time and warm advection aloft has begun. All signals
currently point to raising the high temperatures. Heights aloft
will be on the rise in the wake of the departing upper trof, low
level WAA will be occuring, surface winds will have a largely
westerly component while backing slightly this afternoon, and
temps at this early morning hour are not very cold. The only
clouds should be a swath of high clouds passing west to east. Sans
the HRRR and RAP, the 2m model temps and MOS guidance has exhibited
a pretty good cool bias the last few days. The HRRR and RAP have
peformed rather well and the new forecast for today nudges highs
closer to them with another day of well above average temperatures.
Glass
.LONG TERM: (Tonight through Friday)
Issued at 225 AM CST Sun Jan 18 2015
The models depict a weak surface low migrating east-southeastward
from near Kansas City into southern Illinois tonight along a wind
shift boundary, and then lift this boundary to the east of the CWA
during the day on Monday. There has been some type of this depiction
the last few days in the models, however the placement now is further
south and leaves into question the nature of the surface wind field
on Monday and strength of warm advection. I have lowered temps
slightly as a result, but taking into account the cool bias, not
as much as MOS and they are still above average.
Another northwest flow shortwave will amplify as it moves through
the area Tuesday into Tuesday Night. There is initially a westerly
wind shift on Monday night in response, with increasing baroclinicity
and cold advection on Tuesday and Tuesday night as the heights
aloft really begin to fall. A greater number of the models are now
generating precipitation across southern MO and southern IL on
Tuesday in response to mid level convergence/frontogenesis, weak
large scale ascent, and divergence associated with the ULJ. I have
added some slight chance pops as a result, but these pops may need
to be ramped up should the current model trends persist.
Cooler temperatures, more seasonable for the later part of January,
will prevail during the later part of the week and into the
weekend however confidence in the degree of cooling is low. The
large scale pattern will once again become more amplified with an
upper ridge from the East Pacific into western North America and a
downstream longwave trof dominating a good portion of the Conus
which favors overall cooler weather. However, there is considerable
variability in the deterministic models and GEFS ensemble members
with the shortwaves moving through the longwave leading to lower
than normal predicatability.
Glass
&&
.AVIATION: (For the 12z TAFs through 12z Monday Morning)
Issued at 419 AM CST Sun Jan 18 2015
Just some high level clouds expected today and tonight. W-swly
surface winds will become light this evening as a weak area of low
pressure moves eastward into central MO.
Specifics for KSTL: Just some high level clouds this forecast
period. A w-swly surface wind will become light this evening.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
246 AM CST Sun Jan 18 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 225 AM CST Sun Jan 18 2015
Main forecast issue today is how warm to go with temps. The weak
cold front has pushed east of the area and the core of coolest air
is already centered east of the CWA. Surface winds remain westerly
at this time and warm advection aloft has begun. All signals
currently point to raising the high temperatures. Heights aloft
will be on the rise in the wake of the departing upper trof, low
level WAA will be occuring, surface winds will have a largely
westerly component while backing slightly this afternoon, and
temps at this early morning hour are not very cold. The only
clouds should be a swath of high clouds passing west to east. Sans
the HRRR and RAP, the 2m model temps and MOS guidance has exhibited
a pretty good cool bias the last few days. The HRRR and RAP have
peformed rather well and the new forecast for today nudges highs
closer to them with another day of well above average temperatures.
Glass
.LONG TERM: (Tonight through Friday)
Issued at 225 AM CST Sun Jan 18 2015
The models depict a weak surface low migrating east-southeastward
from near Kansas City into southern Illinois tonight along a wind
shift boundary, and then lift this boundary to the east of the CWA
during the day on Monday. There has been some type of this depiction
the last few days in the models, however the placement now is further
south and leaves into question the nature of the surface wind field
on Monday and strength of warm advection. I have lowered temps
slightly as a result, but taking into account the cool bias, not
as much as MOS and they are still above average.
Another northwest flow shortwave will amplify as it moves through
the area Tuesday into Tuesday Night. There is initially a westerly
wind shift on Monday night in response, with increasing baroclinicity
and cold advection on Tuesday and Tuesday night as the heights
aloft really begin to fall. A greater number of the models are now
generating precipitation across southern MO and southern IL on
Tuesday in response to mid level convergence/frontogenesis, weak
large scale ascent, and divergence associated with the ULJ. I have
added some slight chance pops as a result, but these pops may need
to be ramped up should the current model trends persist.
Cooler temperatures, more seasonable for the later part of January,
will prevail during the later part of the week and into the
weekend however confidence in the degree of cooling is low. The
large scale pattern will once again become more amplified with an
upper ridge from the East Pacific into western North America and a
downstream longwave trof dominating a good portion of the Conus
which favors overall cooler weather. However, there is considerable
variability in the deterministic models and GEFS ensemble members
with the shortwaves moving through the longwave leading to lower
than normal predicatability.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1125 PM CST Sat Jan 17 2015
VFR conditions are expected at the TAF sites thru the valid
period. Surface winds from the W will be maintained until midday-
early Sunday afternoon, with backing and diminishing occurring
ahead of a weak area of low pressure that will approach our
region and light/variable winds continuing into Sunday evening.
Specifics for KSTL: VFR thru the period. Otherwise, look for W
surface winds to diminish/back Sunday afternoon ahead of a weak
area of low pressure approaching upstream with light/variable
winds continuing into Sunday night.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1040 PM MST SAT JAN 17 2015
.AVIATION...
06Z TAF CYCLE
BEEN A TOUGH NIGHT IN TERMS OF FG/LOW CIG DEVELOPMENT ACROSS THE
FOUR CORNERS AREA. RESTRICTIONS HAVE REMAINED ON THE COLORADO SIDE
THROUGH 6Z. INGREDIENTS ARE STILL IN PLACE FOR RESTRICTIONS ON THE
NM SIDE SO JUST DELAYED LIFR CONDITIONS AT FMN UNTIL LATER IN
THE NIGHT. NEXT SHIFT WILL REASSESS AND MONITOR ACCORDINGLY. CIRRUS
CLOUDS WILL EVENTUALLY OVERSPREAD THE AREA. ALSO LOOKING AT A
STRENGTHENING LEE SIDE TROUGH THROUGH THE MORNING TO EARLY
AFTERNOON HORUS BEFORE WEAKENING SOME. GUSTS BETWEEN 20 TO 30 KT
INDICATED AT LVS/TCC.
50
&&
.PREV DISCUSSION...305 PM MST SAT JAN 17 2015...
.SYNOPSIS...
ANOTHER ROUND OF FREEZING FOG AND LOW CLOUDS IS IN STORE FOR
NORTHWEST NEW MEXICO THIS EVENING. LIKE LAST NIGHT...VISIBILITIES
MAY FALL BELOW ONE HALF MILE CREATING A THIN GLAZE OF ICE ON
ROADWAYS. ON SUNDAY...WHILE THE LOW CLOUDS PERSIST ACROSS THE
NORTHWEST...BREEZY TO WINDY WESTERLY WINDS WILL AID IN WARMING UP
TEMPERATURES SEVERAL DEGREES ACROSS THE EASTERN PLAINS. HIGH
TEMPERATURES MAY BE AS MUCH AS 20 DEGREES ABOVE NORMAL. THE WARMTH
WILL REMAIN IN STORE FOR THE AREA ON MONDAY AS WELL. TEMPERATURES
WILL YO-YO BACK DOWNWARD ON TUESDAY THANKS TO A BACK DOOR COLD
FRONT. TEMPERATURES WILL CONTINUE TO FALL AREAWIDE ON WEDNESDAY AS
A STORM SYSTEM APPROACHES NEW MEXICO FROM THE WEST AND A CHANCE OF
PRECIPITATION RETURNS.
&&
.DISCUSSION...
FOG AND LOW CLOUDS HAVE ONCE AGAIN PLAGUED NW NM TODAY. THOUGH THE
FOG LIFTED AT OR SHORTLY BEFORE NOON...THE LOW CLOUDS HAVE PERSISTED
KEEPING TEMPERATURES QUITE COLD AND WELL BELOW ANY GUIDANCE NUMBERS.
GIVEN THAT THEY DID NOT GET OUT OF THE MUCK TODAY...IT IS HIGHLY
LIKELY THAT THE SAME WILL HAPPEN AGAIN TONIGHT AND SUNDAY. NAM BUFR
SOUNDINGS AND HRRR PROGS SUPPORT THIS...AND THEREFORE WILL ISSUE A
FREEZING FOG ADVISORY FROM 9PM TONIGHT TIL 10AM SUN FOR ZONES
501-502-504. FOR ZONE 504...THE GREATEST IMPACTS WILL BE WEST/NW OF
THE CONTDVD.
MEANWHILE...THE BACK DOOR FRONT OR WIND SHIFT HAS PUSHED THROUGH THE
PLAINS AND SOME BREEZY TO LOCALLY WINDY CONDITIONS HAVE BEEN NOTED
BEHIND IT. VERY LOW DEWPOINTS ARE ALSO NOTED BEHIND IT...THUS AS
OPPOSED TO PREVIOUS BACK DOOR FRONTS...NO LOW CLOUDS OR FOG ARE
EXPECTED ACROSS THE EAST TONIGHT.
FOR SUNDAY...WITH LOW CLOUDS LINGERING ACROSS THE NW MOST LIKELY
AGAIN...AND ADDITIONALLY...A BATCH OF HIGH CLOUDS MOVING IN...WENT
BELOW GUIDANCE FOR FARMINGTON AND SURROUNDING AREAS FOR MAX TEMPS.
MEANWHILE...A STRONG LEE SIDE TROUGH WILL DEVELOP ACROSS THE PLAINS
ALLOWING FOR BREEZY TO WINDY WESTERLY WINDS. COMPRESSIONAL WARMING
SHOULD ALLOW TEMPS TO SOAR BETWEEN 5 AND NEARLY 20 DEGREES ABOVE
NORMAL. IN FACT...EXCEPT FOR THE FMN AREA...WESTERN AND CENTRAL
AREAS SHOULD ALSO BE 5 TO 10 DEGREES ABOVE NORMAL. THOUGH NOT AS
MUCH WIND IS EXPECTED ON MONDAY...TEMPERATURES ARE STILL EXPECTED TO
BE QUITE WARM...THOUGH WILL ONCE AGAIN HAVE TO WATCH FOR FOG AND LOW
CLOUDS ACROSS NW NM.
A BACK DOOR COLD FRONT REMAINS IN STORE MONDAY NIGHT AND EARLY
TUESDAY AS A SHORTWAVE TROUGH CROSSES THE UPPER MIDWEST. THIS WILL
RESULT IN TUESDAYS HIGH TEMPERATURES DROPPING AS MUCH AS 20 DEGREES
FROM MONDAYS READINGS. WESTERN AREAS WILL COOL A FEW DEGREES AS
WELL...THANKS TO A VEIL OF UPPER LEVEL CLOUDS.
THE BACK DOOR FRONT LOOKS TO BE REINFORCED LATE TUESDAY AND
WEDNESDAY...RESULTING IN TEMPS CONTINUING TO DROP. WIDESPREAD HIGH
CLOUDS WILL ALSO BE PRESENT AHEAD OF THE NEXT ORGANIZING STORM
SYSTEM. MODELS INDICATE THAT A SHORTWAVE TROUGH WILL DROP SOUTHWARD
INTO AZ OUT OF NW FLOW ALOFT LATE TUESDAY AND WEDNESDAY. MOST MODELS
INDICATE A BAND OF MAINLY SNOW ACROSS NORTHERN NM ALONG THE
DEFORMATION ZONE WEDNESDAY AFTN...THOUGH THERE COULD BE SOME
ENHANCEMENT ACROSS THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN IF
ANY LOW LEVEL EASTERLY UPSLOPE FLOW REMAINS. THE EC IS THE MOST
BULLISH ON THE AMOUNT OF PRECIP...BUT EVEN THEN WOULD ONLY AMOUNT TO
A FEW INCHES OF SNOW.
MODELS CONTINUE TO STRUGGLE WITH WHAT WILL HAPPEN THEREAFTER. THE
GFS SHOWS THE SYSTEM CLOSING OFF NEAR THE BOOTHEEL WHILE THE EC
CONTINUES TO MIGRATE THE TROUGH EASTWARD. BASED ON THE
LATTER...PRECIPITATION SHOULD LARGELY END BY FRIDAY...THOUGH IF THE
GFS IS CORRECT...PRECIP COULD LINGER ACROSS SOUTHERN ZONES INTO THE
WEEKEND. THE GFS ALSO SHOWS ADDITIONAL UPSTREAM ENERGY DROPPING INTO
THE REGION BUT THE PATTERN LOOKS WONKY AT BEST. SIDED MORE WITH THE
DRIER EC AND GFS ENSEMBLE FRI AND BEYOND FOR NOW. STAY TUNED.
34
&&
.FIRE WEATHER...
ONLY SIGNIFICANT FIRE WEATHER CONCERN OVER THE NEXT WEEK WILL BE
THE VENTILATION RATES...WHICH WILL BE MOSTLY POOR TO FAIR.
COLD FRONT MADE IT THROUGH ROSWELL EARLY THIS AFTERNOON. SOME GUSTY
NORTH TO NORTHEAST WINDS BEHIND THE FRONT. MEANWHILE LOW CLOUDS
CONTINUE TO SHROUD THE NORTHWEST TODAY...KEEPING TEMPERATURES AT
OR BELOW FREEZING ALONG THE SAN JUAN RIVER VALLEY. ELSEWHERE IT IS
SUNNY AND RATHER COMFORTABLE FOR MID JANUARY.
TONIGHT WILL BE GENERALLY CLEAR EXCEPT FOR THE LOW CLOUDS OVER THE
NORTHWEST PLATEAU. DENSE FREEZING FOG WILL LIKELY FORM AGAIN AS WELL
THIS EVENING AND CONTINUE INTO SUNDAY MORNING. RH RECOVERIES WILL BE
MOSTLY IN THE 40S AND 50S IN THE EAST BUT 70S AND 80S IN THE WEST.
A NICE DAY ON TAP FOR SUNDAY WITH A GOOD DEAL OF SUNSHINE...ALTHOUGH
FILTERED BY HIGH CLOUDS. BREEZY TO WINDY CONDITIONS WILL BE CONFINED
TO THE CENTRAL HIGHLANDS ONTO THE EAST CENTRAL PLAINS. TEMPERATURES
WILL BE HIGHER AT MOST LOCATIONS...ESPECIALLY IN THE NORTHEAST
THANKS TO A STRENGTHENING LEE OF THE MOUNTAINS TROUGH. MINIMUM RH
VALUES WILL DROP INTO THE TEENS IN THE NORTHEAST...WHILE ELSEWHERE
THEY WILL BOTTOM OUT IN THE 20S AND 30S...40S IN THE NORTHWEST WHERE
CLOUDS MAY LINGER MUCH OF THE DAY ONCE AGAIN AND HOLD DOWN THE HIGH
TEMPERATURES. THE FLY IN THE OINTMENT ON SUNDAY WILL AGAIN BE THE
VENT RATES THAT WILL BE POOR IN MUCH OF THE WEST AND CENTRAL
AREAS...WITH SOME FAIR TO GOOD IN THE EAST OWING TO THE WINDS
HELPING RAISE THE MIXING HEIGHTS SOME. NIGHTTIME RH RECOVERIES WILL
BOTTOM OUT IN THE 50S AND 60S IN THE EAST AND MOSTLY BETWEEN 80 AND
100 PERCENT IN THE WEST.
THE DRY NORTHWEST FLOW ALOFT WILL CONTINUE MONDAY WITH MORE SUNSHINE
AND EVEN MILDER TEMPERATURES FOR MOST AREAS. A WEAK BACK DOOR COLD
FRONT COULD REACH THE NORTHEAST AND PRODUCE HIGH TEMPERATURES A BIT
LOWER THAN SUNDAY. WINDS WILL BE LOWER OVER THE EAST...WITH MODERATE
BREEZES FROM CLINES CORNERS TO SANTA ROSA. MIN RH VALUES WILL BE IN
THE 20S AND 30S. VENT RATES WILL IMPROVE A BIT MOST AREAS...BUT
STILL BE FAIR TO POOR IN THE WEST AND CENTRAL AREAS...WHILE FAIR OR
BETTER IN THE EAST. THERE WILL EVEN BE SOME VERY GOOD TO EXCELLENT
VENT RATES IN THE NORTHEAST THANKS TO HIGHER MIXING HEIGHTS.
THE COLD FRONT WILL CONTINUE SOUTH AND WEST MONDAY NIGHT WITH A MUCH
COOLER DAY ON TAP FOR TUESDAY ACROSS THE AREA...BUT ESPECIALLY SO IN
THE EAST. MIN RH VALUES WILL ONLY LOWER TO THE 30S AND 40S. TUESDAY
WILL BE DRY WITH GUSTY NORTH WINDS IN THE EAST DURING THE MORNING
DIMINISHING THROUGHOUT THE AFTERNOON. VENT RATES WILL DROP BACK TO
MOSTLY FAIR TO POOR VALUES TUESDAY...EXCEPT SOME GOOD RATES RIGHT
ALONG THE EASTERN BORDER.
A REINFORCING FRONT WILL PRESS SOUTH ACROSS THE AREA TUESDAY NIGHT
AND WEDNESDAY. LOWER LEVEL MOISTURE WILL BE ON THE INCREASE AND WE
COULD SEE OUR FIRST LIGHT PRECIPITATION OF THE WEEK DEVELOP OVER THE
NORTHERN HIGH TERRAIN TUESDAY NIGHT IN THE FORM OF SNOW SHOWERS. THE
NIGHTTIME RH RECOVERIES WILL BE MOSTLY EXCELLENT.
A STRENGTHENING TROUGH TO OUR WEST MAY DEVELOP INTO A CLOSED LOW
NEAR THE BOOTHEEL WEDNESDAY NIGHT AND THURSDAY. THIS WILL HELP BRING
ADDITIONAL MOISTURE TO THE STATE. WIDESPREAD RAIN AND SNOW SHOWERS
ARE FORECAST FOR WEDNESDAY INTO THURSDAY...ALONG WITH CHILLY...BELOW
NORMAL TEMPERATURES AND DAYTIME MIN RH VALUES ONLY IN THE 40S TO
60S. AGAIN THE VENT RATES WILL BE MOSTLY FAIR TO POOR ON WEDNESDAY
AND THURSDAY.
MOST MODELS THEN DRY THINGS OUT FOR FRIDAY INTO NEXT WEEKEND WITH A
MODERATION IN TEMPERATURES.
CHJ
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 10 AM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ501-503-504.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
307 PM EST SUN JAN 18 2015
.SYNOPSIS...
WIDESPREAD WINTRY PRECIPITATION...OCCASIONALLY HEAVY...WILL AFFECT
THE EASTERN HALF OF THE FORECAST AREA TONIGHT INTO EARLY MORNING
MONDAY AS LOW PRESSURE TRACKS THROUGH NEW ENGLAND. BEHIND THIS
SYSTEM...HIGH PRESSURE WILL GENERALLY CONTROL WEATHER CONDITIONS FOR
MUCH OF NEXT WEEK WITH MAINLY DRY AND SEASONABLY COLD WEATHER
EXPECTED.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
AS OF 307 PM EST SUNDAY...COMPLEX WEATHER SCENARIO CONTINUES TO
UNFOLD ACROSS THE NORTHEAST THIS EVENING AS COPIOUS MOISTURE IS
DRIVEN NORTHWARD AHEAD OF AN ADVANCING NORTHERN STREAM UPPER
TROUGH. IMPRESSIVE FRONTOGENESIS HAS DEVELOPED ALONG THE PRIMARY
COASTAL FRONT TO OUR SOUTH THIS AFTERNOON WITH A WIDE DISPARITY IN
TEMPERATURE PROFILES ACROSS THE BOUNDARY AND THEMALLY DRIVEN
VERTICAL MOTIONS LEADING TO A 75-100 NM BAND OF MODERATE TO HEAVY
PCPN WITH EMBEDDED THUNDER. AS DEEP SOUTHERLY FLOW ALOFT CONTINUES
INTO THIS EVENING...THIS PCPN WILL CONTINUE TO DRIVE NORTHWARD
INTO THE EASTERN HALF OF OUR AREA. SOME REPORTS OF -FZRA OCCURRING
ACROSS CENTRAL/SRN VT ON LEADING EDGE OF THIS PCPN AND STILL
EXPECT SOME LIGHT ICING CONCERNS IN THESE AREAS THROUGH EARLY
EVENING. THEREAFTER HAVE OFFERED MAINLY A RAIN/SNOW SCENARIO AS
LARGE-SCALE WARM THERMAL ADVECTIVE PROCESSES WILL BE COMING TO AN
END BY THAT POINT. HOWEVER...THOSE THERMAL PROFILES IN THE LOWER
TO MID LEVELS REMAIN QUITE PROBLEMATICAL IN THE SENSE OF
PREDICTING EXACT TIMING OF RAIN/SNOW CHANGEOVER AND TOTAL SNOWFALL
AMOUNTS. FOR THE SAKE OF CONTINUITY...USED A MULTI-MODEL BLEND FOR
QPF...AND MOST RECENT RAP THERMAL PROFILES TO LARGELY GOVERN THE
FORECAST THROUGH THE EVENING AND OVERNIGHT HOURS. THIS WOULD
SUGGEST HIGHEST TOTALS ACROSS THE HIGHER TERRAIN OF CENTRAL/NRN VT
(5-11 INCHES)...WITH LESSER AMOUNTS IN THE VT VALLEYS (2-6 INCHES)
AND ACROSS NRN NY (1-4 INCHES) WHICH WILL BE TOO FAR WEST TO
EXPERIENCE HEAVIER FGEN/QPF. I WILL NOTE THAT MOST RECENT TRENDS
IN THE NEAR- TERM HRRR/RAP GUIDANCE SUGGEST PRIMARY PCPN SHIELD IS
TENDING TO SHIFT A TAD FURTHER EAST THAN CURRENT FORECAST. IF THIS
PANS OUT...SNOWFALL AMOUNTS ACROSS WESTERN VT MAY BE A TAD LESS
THAN CURRENT FORECASTS. TIME WILL TELL HOWEVER...AND ALL
ADVISORIES AND WARNINGS WILL REMAIN IN PLACE WITH THIS PACKAGE.
LOWS GENERALLY IN THE UPPER 20S TO LOWER 30S BY MONDAY MORNING.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 307 PM EST SUNDAY...LINGERING/WRAP-AROUND LIGHT SNOWS
AND/OR SHSN THEN FADE WITH TIME DURING THE COURSE OF MONDAY AS
DEEPER MOISTURE LIFTS QUICKLY NORTH AND EAST FROM THE AREA. MODEST
COLD THERMAL ADVECTION ON WEST TO NORTHWESTERLY FLOW WILL KEEP
TEMPERATURES IN CHECK AND IN MOST LOCALES NEAR STEADY VALUES IN
THE UPPER 20S TO MID 30S ARE EXPECTED. ANY LINGERING MINOR
ACCUMULATIONS WOULD TEND TO OCCUR IN THE MORNING HOURS.
THEREAFTER...BROAD HIGH PRESSURE ACROSS THE UPPER MIDWEST/GREAT
LAKES BUILDS EAST/SOUTHEAST INTO OUR REGION AND WILL SET UP SHOP FOR
MUCH OF NEXT WEEK. THUS GENERALLY DRY WEATHER WILL BE OFFERED WITH
SEASONABLY COLD MID-WINTER TEMPERATURES EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM EST SUNDAY...VERY LITTLE CHANGE FROM PREVIOUS COUPLE
OF DAYS FCST WITH REGARDS TO LARGE SCALE SYNOPTIC PATTERN...WHICH
FEATURES BLW NORMAL CHCS FOR PRECIP AND SLIGHTLY BLW NORMAL TEMPS.
ALL LONG TERM GUIDANCE...INCLUDING THE 12Z GFS/ECMWF AND 00Z
ENSEMBLE DATA SUPPORTS MEAN MID/UPPER LVL TROF ACRS THE GREAT
LAKES INTO THE NORTHEAST CONUS WITH OUR CWA UNDER THE INFLUENCE OF
THE NORTHERN JET. THE BEST CHC FOR SNOW SHOWERS WL COME ALONG SAT
INTO SUNDAY OF NEXT WEEKEND ASSOCIATED WITH WEAK CLIPPER LIKE
SYSTEM. LATEST PROGS SHOW THIS SYSTEM TRACKING ACRS THE NORTHERN
GREAT LAKES AND INTO EASTERN CANADA BY NEXT SUNDAY...WHICH PLACES
OUR CWA IN THE BRISK SOUTHWEST FLW AND IMPACTS OF SHADOWING OFF
THE DACKS ACRS THE CPV. IN ADDITION...BEST RH PROGS AND ULVL
SUPPORT WL BE MAINLY NORTH OF OUR FA...SUPPORTING ONLY LIGHT SNOW
ACCUMULATION. HAVE MENTION CHC POPS ATTM. OTHERWISE...DRY FCST
EXPECTED FROM WEDS UNTIL SATURDAY...WITH LOWS IN THE -5F TO +5F
COLDER VALLEYS TO NEAR 10F CPV...AND HIGHS MAINLY IN THE TEENS TO
MID 20S. A SLIGHT WARMING TREND IS EXPECTED BY NEXT WEEKEND WITH
LOWS IN THE TEENS AND HIGHS IN THE 20S TO POSSIBLY NEAR 30F CPV.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...HIGH IMPACT TO AVIATION EXPECTED LATE THIS
AFTN UNTIL EARLY MONDAY MONDAY...ASSOCIATED WITH POTENTIAL
ICING...HEAVY SNOW AND DEVELOPING IFR/LIFR CONDITIONS TONIGHT.
CRNT RADAR SHOWS BAND OF HEAVY PRECIP ALONG THE MID ATLANTIC
COAST...MOVING TWD SOUTHERN VT ATTM. THIS PREICP WL IMPACT
RUTLAND BY 19Z AND MPV BY 20Z...AND INTO BTV/PBG BTWN 21Z AND 23Z
THIS EVENING. GIVEN VERY COLD SUB-SFC TEMPS...EXPECT RAIN TO
FREEZE ON CONTACT WITH THE GROUND...ESPECIALLY AT MPV WITH SOME
LIGHT ICING LIKELY THIS EVENING. OTHERWISE...AS THE HEAVIER PRECIP
ARRIVES THIS EVENING...EXPECT THE RAIN TO CHANGE TO SNOW BTWN 00Z
AND 03Z ACRS OUR CENTRAL AND EASTERN TAF SITES. A PERIOD OF
MODERATE TO HEAVY SNOW IS EXPECTED AT RUT/MPV/BTV WITH LIFR/VLIFR
CONDITIONS LIKELY BTWN 03Z-08Z. AFT 08Z CONDITIONS WL SLOWLY
IMPROVE TO IFR CIGS WITH PERIODS OF MVFR/IFR VIS IN AREAS OF LIGHT
RAIN AND SNOW SHOWERS ACRS OUR CENTRAL/EASTERN TAF SITES.
MEANWHILE...AT MSS/SLK MUCH LESS IMPACTS ARE ANTICIPATED WITH
LIGHT RAIN/SNOW AND DEVELOPING IFR CONDITIONS AT SLK AND MAINLY
MVFR AT MSS. UPSLOPE SNOW SHOWERS WL PERSIST AT SLK/MPV ON MONDAY
WITH IFR CIGS/VIS LIKELY THRU 15Z. IN ADDITION...STRONG 925MB TO
850MB WINDS OF 40 TO 50 KNOTS WL SLOWLY DECREASE THIS
EVENING...ALONG WITH THE LLVL WINDSHEAR AND TURBULENCE.
OUTLOOK 18Z MONDAY THROUGH THURSDAY...DEPARTING LOW PRES WL
RESULTING IN IMPROVING CONDITIONS AFT 18Z MONDAY...WITH VFR
DEVELOPING BY 00Z TUES. THESE CONDITIONS WL PREVAIL THRU THE
WEEK...WITH WEAK SFC HIGH PRES OVERHEAD.
&&
.HYDROLOGY...
A QUICK MOVING AREA OF LOW PRES ALONG THE MID ATLANTIC COAST WILL
SPREAD A PERIOD OF MODERATE TO HEAVY PRECIPITATION ACROSS OUR
CENTRAL AND EASTERN CWA TONIGHT. A SHARP PRECIPITATION GRADIENT IS
EXPECTED FROM WEST TO EAST ACRS OUR REGION...WITH TOTAL AMOUNTS
RANGING FROM A COUPLE TENTHS SLV/NORTHERN DACKS TO 0.75 AND 1.50
OVER CENTRAL/SOUTHERN AND EASTERN VT ZNS BY 12Z MONDAY. GIVEN THE
VERY INTENSE RATE OF PRECIP ANTICIPATED AND SOME OF THIS FALLING IN
THE FORM OF RAIN...SHARP WITHIN BANK RISES ARE POSSIBLE ON LOCAL
STREAMS AND RIVERS...WHICH COULD RESULT IN A FEW BREAK UP ICE JAMS.
THE GREATEST POTENTIAL WILL BE ACROSS THE SMALLER STREAMS AND
RIVERS OF ADDISON...RUTLAND....WINDSOR...AND ORANGE COUNTIES
THROUGH 18Z MONDAY. NO WIDESPREAD OR LARGE SCALE FLOODING IS
ANTICIPATED ATTM...ONLY MINOR IF ANY AT ALL.
&&
.EQUIPMENT...
AS OF 1259 PM EST SUNDAY...THERE HAVE BEEN NO AUTOMATED SURFACE
OBSERVATIONS AT THE ADIRONDACK AIRPORT/SARANAC LAKE (KSLK) SINCE
EARLY THIS MORNING. INTERMITTENT POWER OUTAGES AT THE SLK ASOS IS
THE SUSPECTED CAUSE OF THE OUTAGE. THE FAA AND ELECTRONICS
TECHNICIANS ARE AWARE OF THE OUTAGE AND ARE WORKING TO RESTORE
OBSERVATIONS AT SARANAC LAKE, BUT NO ESTIMATED RETURN TO SERVICE
IS KNOWN AT THIS TIME.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR VTZ001-005-009.
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR VTZ002>004-006>008-016>018.
WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR VTZ010>012-
019.
NY...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR NYZ028-035.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...TABER
AVIATION...TABER
HYDROLOGY...TABER
EQUIPMENT...LOCONTO
AREA FORECAST DISCUSSION
NWS BUFFALO NY
930 AM EST SUN JAN 18 2015
.SYNOPSIS...
A PUSH OF WARM AIR WILL BRING TEMPERATURES WELL ABOVE FREEZING
THROUGH MUCH OF TODAY BEFORE COLDER AIR FILTERS BACK IN TONIGHT
BEHIND A COLD FRONT. THE FRONT WILL BRING A FEW RAIN SHOWERS TODAY
AT LOWER ELEVATIONS AND A MIX OF RAIN AND WET SNOW ACROSS HIGHER
TERRAIN. PRECIPITATION WILL CHANGE BACK TO ALL SNOW TONIGHT WITH
SOME MINOR ACCUMULATIONS POSSIBLE ESPECIALLY ACROSS HIGHER TERRAIN.
TEMPERATURES WILL REMAIN CLOSE TO NORMAL THROUGH MUCH OF THE
UPCOMING WEEK WITH SEVERAL WEAK SYSTEMS BRINGING A CHANCE OF LIGHT
SNOW AT TIMES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 900 AM...THE COLD FRONT WAS JUST ENTERING WESTERN NEW
YORK...WITH A BRIEF PERIOD OF GUSTY SOUTHWEST WINDS ALONG THE LAKE
ERIE SHORELINE AND NIAGARA FRONTIER. THIS SHOULD ONLY LAST A
COUPLE HOURS...SINCE IT IS MAINLY DUE TO FUNNELING AS THE FRONT
MOVES THROUGH. ELSEWHERE...WINDS ALOFT HAVE DIMINISHED...WITH
SOUTHERLY DOWNSLOPE WINDS EXCEPTED TO DIMINISH.
TEMPERATURES HAVE DROPPED MARKEDLY WITH THE FRONT...FROM THE LOWER
TO MID 40S TO THE MID TO UPPER 30S WITH THE WIND SHIFT. FOR
WESTERN AREAS...THE HIGH FOR THE DAY HAS ALREADY BEEN
REACHED...WITH STEADY OR SLOWLY FALLING TEMPERATURES FOR THE REST
OF THE DAY. OTHERWISE...EXPECT LITTLE CHANGE IN TEMPERATURES
ACROSS HIGHER TERRAIN WITH THE FRONTAL PASSAGE...BUT A QUICK 5
DEGREE DROP IN DOWNSLOPE REGIONS AS THE FRONT MOVES THROUGH LATE
THIS MORNING AND EARLY AFTERNOON.
THE INITIAL ROUND OF PRECIPITATION IS FINALLY MOVING INTO WESTERN
NEW YORK...AND THIS WILL MOVE EAST WITH THE FRONT AND BRING LIGHT
SHOWERS. THE MILD TEMPERATURES WILL ALLOW MUCH OF THE INITIAL
PRECIPITATION TO FALL AS RAIN...WITH SOME WET SNOW POSSIBLY MIXING
IN ACROSS HIGHER TERRAIN.
IN TERMS OF MODEL GUIDANCE...THE HRRR WAS PREFERRED DUE TO ITS
ABILITY TO CAPTURE THE ABRUPT TEMPERATURE CHANGES WITH THE
FRONT. IT ALSO HANDLES SHOWERS FAIRLY SIMILAR TO A CONSENSUS OF
THE NAM/RGEM/SREF...WHICH MATCHES UP WITH RADAR TRENDS WELL.
THE MID LEVEL TROUGH WILL ADVANCE EAST INTO THE AREA TODAY AND
PROVIDE INCREASING LARGE SCALE ASCENT IN THE FORM OF DPVA AHEAD OF A
STRONG EMBEDDED VORTICITY MAXIMA...AND UPPER LEVEL DIVERGENCE WITHIN
A DEVELOPING COUPLED JET STRUCTURE ALOFT AS THE NORTHERN AND
SOUTHERN STREAMS BEGIN TO PHASE ALONG THE EAST COAST. THIS PHASING
OF STREAMS WILL DIRECT THE BULK OF STRONGER ASCENT AND MOISTURE
CONVERGENCE WELL EAST OF OUR AREA. AT THE SURFACE A COLD FRONT WILL
CROSS THE REGION FROM WEST TO EAST THIS AFTERNOON. THE COMBINATION
OF LARGE SCALE ASCENT AND LOW LEVEL CONVERGENCE ALONG THE COLD FRONT
WILL PRODUCE A BRIEF PERIOD OF PRECIP MOVING FROM WEST TO EAST
ACROSS THE AREA. THIS WILL REACH WESTERN NY AROUND MID TO LATE
MORNING...THEN MOVE TO THE GENESEE VALLEY BY EARLY AFTERNOON BEFORE
FINALLY REACHING CENTRAL NY AND THE NORTH COUNTRY LATE IN THE
AFTERNOON. THE GREATEST CHANCES OF MEASURABLE PRECIP WILL BE FOUND
ACROSS HIGHER TERRAIN...WITH ONGOING SOUTHERLY DOWNSLOPE WINDS
FORCING LOWER AMOUNTS ON THE LAKE PLAINS.
THERE SHOULD BE A SEVERAL HOUR DRY GAP BETWEEN THE INITIAL BATCH OF
PRECIPITATION AND DEEPER WRAP AROUND MOISTURE...WHICH WILL ARRIVE IN
WESTERN NY BY LATE AFTERNOON THEN SLOWLY OVERSPREAD THE REST OF THE
AREA TONIGHT. COLD ADVECTION WILL COOL BOUNDARY LAYER TEMPS ENOUGH
TO CHANGE ANY REMAINING PRECIP OVER TO ALL SNOW BY MID TO LATE
EVENING. EXPECT THE GREATEST COVERAGE OF SNOW TO BE FOUND ACROSS THE
WESTERN SOUTHERN TIER FROM LATE AFTERNOON THROUGH EVENING WITH SOME
MODEST LAKE ENHANCEMENT OFF THE OPEN PATCH OF WATER ON LAKE ERIE AND
MORE IMPORTANTLY UPSLOPE FLOW. THIS MAY PRODUCE 1-2 INCH AMOUNTS
TONIGHT ACROSS THE HIGHER TERRAIN. MODEST LAKE ENHANCEMENT WILL ALSO
DEVELOP LATE TONIGHT SOUTHEAST OF LAKE ONTARIO WITH UPSLOPE ALSO
INCREASING ACROSS THE TUG HILL AND WESTERN FOOTHILLS OF THE
ADIRONDACKS LATE TONIGHT. THIS MAY PRODUCE UP TO AN INCH
ACCUMULATION. ELSEWHERE EXPECT ANY ACCUMULATION TO BE MINIMAL. COLD
ADVECTION BEHIND THE FRONT IS ONLY MODEST...SO EXPECT LOWS IN THE
MID 20S IN MOST AREAS BY EARLY MONDAY MORNING AND ONLY AROUND 30 TO
THE SOUTHEAST OF LAKE ONTARIO.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AN UPPER LEVEL TROUGH WILL CROSS UPSTATE NEW YORK ON MONDAY...AS A
COASTAL LOW LIFTS NORTHWARD THROUGH MAINE. THE WESTERLY TO
NORTHWESTERLY FLOW AND DEEPENING COLD AIR WILL PRODUCE SOME LAKE
EFFECT SNOW SHOWERS EAST OF LAKES ERIE AND ONTARIO. SOME LIGHT SNOW
ACCUMULATIONS OF A COUPLE TO A FEW INCHES ARE POSSIBLE IN THESE LAKE
SNOWS. THE LAKE EFFECT PARAMETERS WILL BE RATHER MARGINAL WITH LAKE
TO 850MB TEMPS BARELY FAVORABLE...BUT SOME ADDITIONAL LOW LEVEL
OROGRAPHIC FORCING SHOULD PROVE ENOUGH LIFT TO MAINTAIN SNOW SHOWERS
MONDAY MORNING BEFORE DIMINISHING MONDAY AFTERNOON. HIGH TEMPERATURES
ACROSS THE AREA ON MONDAY WILL SETTLE TO THE MID 20S.
A NARROW RIDGE OF SURFACE HIGH PRESSURE BUILDS INTO THE LOWER LAKES
MONDAY NIGHT. LOW PRESSURE STALLS ACROSS THE GULF OF SAINT LAWRENCE
AND WILL KEEP SOME SNOW SHOWERS ACROSS THE TUG HILL AND CENTRAL NEW YORK
WITH GENERALLY DRY CONDITIONS ELSEWHERE.
A CLIPPER WILL PASS MAINLY TO THE SOUTH OF THE REGION ON TUESDAY
NIGHT AND WEDNESDAY WITH A GENERAL LIGHT SNOW ACROSS THE SOUTHERN HALF
OF THE FORECAST AREA. PRECIPITATION AMOUNTS WILL BE VERY LIGHT WITH
THIS SYSTEM...AS THE STRONGER SYNOPTIC FORCING ACROSS PA...BUT SOME
NORTHERLY UPSLOPE WINDS SHOULD HELP TO MAINTAIN SOME LIGHT SNOW
SHOWERS THROUGH THE DAY WEDNESDAY ACROSS THE SOUTHERN TIER AND
NORTHERN FINGER LAKES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
LONG RANGE MODELS AND ENSEMBLES ARE IN GOOD AGREEMENT ABOUT A LARGE
SCALE RIDGE DEVELOPING OVER THE WEST COAST FOR THE END OF THE WEEK
THROUGH THE BEGINNING OF NEXT WEEK. THIS PATTERN OPENS UP THE
EASTERN HALF OF THE COUNTRY TO COLD AIR INTRUSIONS WITH A GENERAL
LARGE SCALE TROUGH ACROSS THE EASTERN HALF OF THE COUNTRY. WHILE
MODELS CONTINUE TO STRUGGLE WITH THE EXACT DETAILS OF THE WEATHER
SYSTEMS IN THE EXTENDED...THE OVERALL THEME WILL BE BELOW NORMAL
TEMPERATURES AND INCREASED CHANCES FOR SNOW FROM MULTIPLE SHORTWAVE
EMBEDDED IN THE LARGE SCALE TROUGH. THERE IS SOME GENERAL AGREEMENT
BETWEEN THE GFS AND ECMWF FOR A SHORTWAVE TO BRING SOME GENERAL
LIGHT SNOW ON SATURDAY...FOLLOWED BY SOME LAKE EFFECT SNOW SHOWERS
THROUGH SUNDAY.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AT 14Z...A COLD FRONT HAD JUST REACHED BUF/IAG AND WILL CONTINUE
ITS EASTWARD PROGRESSION. SHOWERS WITH THIS FRONT WILL ALSO SPREAD
FROM W-E...BUT THEY WILL BE ON THE LIGHT SIDE AND ONLY LAST A
COUPLE HOURS. ERI/DKK BOTH BRIEFLY DROPPED TO IFR IN CIGS...SO
THIS MAY HAPPEN BRIEFLY AT BUF JUST BEHIND THE FRONT.
THERE WILL BE A BREAK OF AT LEAST A FEW HOURS BETWEEN THE INITIAL
BATCH OF PRECIPITATION AND ADDITIONAL MOISTURE WHICH WILL ARRIVE
IN WESTERN NY BY LATE AFTERNOON OR EARLY EVENING...THEN SPREAD
SLOWLY EAST ACROSS THE REST OF THE AREA TONIGHT. COLDER AIR WILL
ALLOW THIS TO CHANGE TO ALL SNOW BY MID EVENING. EXPECT AREAS OF
MVFR VSBY IN LIGHT SNOW SHOWERS AT LOWER ELEVATIONS TONIGHT...WITH
IFR VSBY IN SOMEWHAT STEADIER LIGHT SNOW ACROSS THE HIGHER TERRAIN
OF THE WESTERN SOUTHERN TIER.
CIGS WILL PRIMARILY BE VFR THIS MORNING UNTIL THE FIRST BATCH OF
PRECIPITATION ARRIVES. FROM THAT POINT THEY WILL QUICKLY
DETERIORATE TO MVFR FROM WEST TO EAST...WITH IFR BECOMING LIKELY
ACROSS HIGHER TERRAIN THIS AFTERNOON. TONIGHT CIGS WILL REMAIN
MVFR AT LOWER ELEVATIONS AND IFR ACROSS HIGHER TERRAIN.
OUTLOOK...
MONDAY...MVFR/VFR WITH SCATTERED LIGHT SNOW SHOWERS...MVFR/IFR IN
LAKE EFFECT SNOW SHOWERS SOUTHEAST OF THE LAKES.
TUESDAY...MAINLY VFR.
WEDNESDAY AND THURSDAY...AREAS OF MVFR WITH A CHANCE OF LIGHT SNOW.
&&
.MARINE...
SOUTHERLY WINDS HAVE DROPPED OFF IN MOST AREAS EXCEPT ACROSS
EASTER LAKE ONTARIO. THIS ALLOWED THE FIRST ROUND OF SMALL CRAFT
ADVISORIES TO BE DROPPED ON THE SOUTH SHORES OF LAKE ONTARIO.
THERE WILL BE BRIEFLY GUSTY SOUTHWEST WINDS ON LAKE ERIE...SO
OPTED TO EXTEND THE SMALL CRAFT EVEN THOUGH THERE WILL BE A 3 TO 6
HOUR LULL THIS AFTERNOON.
A COLD FRONT WILL CROSS LAKE ONTARIO TODAY TODAY WITH WINDS
BECOMING MORE WESTERLY TONIGHT BEHIND THE FRONT. THIS WILL BRING
ANOTHER ROUND OF SMALL CRAFT ADVISORY CONDITIONS ON LAKE ONTARIO
TONIGHT THROUGH MONDAY NIGHT. WINDS WILL BE MORE MARGINAL ON LAKE
ERIE BEHIND THE COLD FRONT...BUT SHOULD STILL INCREASE TO SMALL
CRAFT ADVISORY CRITERIA FOR A SHORT TIME FROM LATE THIS AFTERNOON
THROUGH THIS EVENING.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 1 AM MONDAY TO 7 AM EST
TUESDAY FOR LOZ043-044.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 10 PM EST
MONDAY FOR LOZ042.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
LOZ045.
SMALL CRAFT ADVISORY FROM 3 AM MONDAY TO 7 AM EST TUESDAY
FOR LOZ045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...CHURCH
LONG TERM...CHURCH
AVIATION...APFFEL/HITCHCOCK
MARINE...HITCHCOCK/APFFEL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
251 PM EST SUN JAN 18 2015
.SYNOPSIS...
WEAK COLD FRONT EXITS THIS AFTERNOON. RELATIVELY MINOR SYSTEM
IMPACTS AREA ON WEDNESDAY THEN GENERALLY DRY WITH SEASONABLE
TEMPERATURES.
&&
.NEAR TERM /THROUGH MONDAY/...
COLD FRONT EXITS THE EASTERN MOUNTAINS BY SUNSET. MODELS INDICATE
THAT DESCENT COLD AIR ADVECTION BEHIND THE FRONT WILL BEING H85
TEMPERATURES TO MINUS 8C TO SUPPORT SNOW ACROSS THE NORTHERN
SECTIONS OF SOUTHEAST OH AND NORTHERN AND NORTHEAST MOUNTAINS OF
WV TONIGHT. WWD GUIDANCE SUGGESTS 2 TO 4 INCHES OF SNOW POSSIBLE
OVER THE NORTHEAST MOUNTAINS. ALL MODELS SUGGEST SOME PCPN IN
THEIR QPF FIELDS MAINLY ACROSS THE NORTHEAST MOUNTAINS. THE HIGH
RESOLUTION MODELS...WRF AND RUC13 ALSO INDICATE SOME KIND OF
BANDING PCPN MAINLY ACROSS THE NORTHEAST MOUNTAINS AND WESTERN
COUNTIES. THE NAM AND WRF MODELS SHOW SOME INDICATIONS THAT THE
MOISTURE PLUME COMES FROM LAKE MICHIGAN. THIS MOISTURE WILL LIKELY
BE ENHANCED BY A SMALL UPSLOPE COMPONENT UNDER WEST NORTHWEST FLOW.
THE NAM AND HYSPLIT BACKWARD TRAJECTORIES SUGGEST THAT MOISTURE
SHOULD COME FROM LAKE MICHIGAN...PLUS LINGERING MOISTURE BEHIND
THE FRONT...COULD PRODUCE PERIODS OF SNOW ACROSS THE NORTH AND
NORTHEAST MOUNTAINS OVERNIGHT TONIGHT. CONTINUED WITH HIGH POPS
ACROSS OUR NORTHEAST QUADRANT FOR TONIGHT.
HOWEVER...MODELS DID NOT DEPICT THE INTENSITY OF PCPN ALONG THE
COLD FRONT TODAY...AS THEY LOOKED OVERDONE. THIS INSERTS SOME
UNCERTAINTY TO THE FORECAST. THEREFORE...CODED UP TO 2 INCHES OF
SNOW OVER THE NORTHEAST MOUNTAINS...EXTENDING WEST TO COVER FEW
COUNTIES WITH LIKELY POPS...AND LOW CHANCE POPS ELSEWHERE.
WINDS SHOULD SUBSIDE SOME TONIGHT RESULTING IN LIGHT TO GENTLE
WEST TO NORTHWEST FLOW.
WENT MAINLY WITH MOS GUIDANCE FOR TEMPERATURES WITH MINOR TWEAKS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
STILL A BIT OF UNCERTAINTY REGARDING MIDWEEK WITH A SERIES OF
DISTURBANCES AND ASSOCIATED BAROCLINIC ZONES DROPPING THRU BROAD
UPPER TROF. FOLLOWED HPC PREFERRED SOLUTION CLOSE TO GFS. MOST
NOTABLE CHANGE FROM PREVIOUS FORECAST WAS TO DELAY ARRIVAL OF POPS
ACROSS THE NW UNTIL TUESDAY AFTERNOON. STILL LOOKS LIKE THE WEAK
SURFACE LOW WILL TRACK ACROSS N WV ON WEDNESDAY WITH SUBSEQUENT
FROPA SWINGING DO THRU REMAINDER OF CWA WEDNESDAY EVENING. HAVE
PRECIP SLOWLY MIXING WITH AND EVENTUALLY CHANGING TO -SN ACROSS THE
AREA WEDNESDAY AFTERNOON AND EVENING WITH THE MOUNTAINS AND SE OH
CHANGING WEDNESDAY MORNING. HAVE SOME MINOR ACCUMULATIONS IN THE
MOUNTAINS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A CLIPPER EXITS THE REGION ON THURSDAY MORNING WITH LIGHT RAIN
AND SNOW SHOWERS DECREASING. AFTER THAT...MODELS DIVERGE ON THE
DETAILS...BUT THEY ALL AGREE THAT THERE IS NOTHING TOO SIGNIFICANT
TO NOTE UNTIL SUNDAY NIGHT WHEN A MORE ORGANIZED SYSTEM APPROACHES
IN A SHARPER UPPER TROUGH. STILL WAY TOO FAR OUT TO PUT ANY WEIGHT
IN THIS. TEMPERATURES APPEAR TO REMAIN SEASONABLE WITH HIGHS IN
THE 40S AND LOWS IN THE 20S IN MOST PLACES.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
COLD FRONT EXITS THE EASTERN MOUNTAINS THIS AFTERNOON LEAVING MVFR
CEILINGS...ABOUT 2200 FEET...AND GUSTY WINDS UP TO 24 KNOTS BEHIND
IT. A SECOND WAVE IN THE MID LEVELS WILL REINFORCE THE COLD AIR
BEHIND THE FRONT AND SQUEEZE LINGERING MOISTURE FURTHER DOWN...TO
1500 FEET OVERNIGHT AT MOST SITES ACCORDING WITH SREF MODEL AND
BUFKIT SOUNDINGS.
EXPECT WINDS TO SUBSIDE AND TURNING MORE FROM THE WEST WITH A
LITTLE COMPONENT FROM THE NORTHWEST TONIGHT...WITH CEILINGS
DROPPING TO LOW MVFR. LIGHT SNOW WILL BE POSSIBLE OVER THE
NORTHEAST MOUNTAINS TO AFFECT EKN AND SURROUNDING AREAS WITH
PERIODS OF IFR. ALTHOUGH CONFIDENCE IS LOW DUE TO A SHALLOW LAYER
OF MOISTURE...DECIDED NOT TO INCLUDE IFR AT EKN AT THIS TIME.
GUIDANCE SUGGESTS IMPROVING CONDITIONS POSSIBLE EARLY MONDAY
MORNING SPREADING FROM SOUTHWEST TO CENTRAL WV WITH SOME CLEARING.
THEREFORE...VFR CONDITIONS COULD PREVAIL MONDAY AT LEAST OVER
HTS...CRW...AND BKW BY MID DAY...AND THE REST OF SITES DURING THE
AFTERNOON HOURS.
CHANCES FOR PCPN INCREASE TUESDAY NIGHT WITH A SERIES OF UPPER
WAVES PASSING BY. TEMPERATURES COULD SUPPORT SNOW ACROSS THE
NORTHERN PORTIONS OF WV INCLUDING THE NORTHEAST MOUNTAINS FOR
PERIODS OF IFR CONDITIONS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: MAY NEED TO ADD RESTRICTIONS IN LIGHT SNOW
AFTER 03Z MONDAY FOR CKB AND EKN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H H H H M H H H H H H H
HTS CONSISTENCY M M M M M M M M M H H H
BKW CONSISTENCY M M M H H H H H H H H L
EKN CONSISTENCY M M M M M L L L M M M H
PKB CONSISTENCY H H H H H H H H H H M M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30/JW
NEAR TERM...ARJ
SHORT TERM...30
LONG TERM...JW
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
250 PM EST SUN JAN 18 2015
.SYNOPSIS...
WEAK COLD FRONT EXITS THIS AFTERNOON. RELATIVELY MINOR SYSTEM
IMPACTS AREA ON WEDNESDAY THEN GENERALLY DRY WITH SEASONABLE
TEMPERATURES.
&&
.NEAR TERM /THROUGH MONDAY/...
COLD FRONT EXITS THE EASTERN MOUNTAINS BY SUNSET. MODELS INDICATE
THAT DESCENT COLD AIR ADVECTION BEHIND THE FRONT WILL BEING H85
TEMPERATURES TO MINUS 8C TO SUPPORT SNOW ACROSS THE NORTHERN
SECTIONS OF SOUTHEAST OH AND NORTHERN AND NORTHEAST MOUNTAINS OF
WV TONIGHT. WWD GUIDANCE SUGGESTS 2 TO 4 INCHES OF SNOW POSSIBLE
OVER THE NORTHEAST MOUNTAINS. ALL MODELS SUGGEST SOME PCPN IN
THEIR QPF FIELDS MAINLY ACROSS THE NORTHEAST MOUNTAINS. THE HIGH
RESOLUTION MODELS...WRF AND RUC13 ALSO INDICATE SOME KIND OF
BANDING PCPN MAINLY ACROSS THE NORTHEAST MOUNTAINS AND WESTERN
COUNTIES. THE NAM AND WRF MODELS SHOW SOME INDICATIONS THAT THE
MOISTURE PLUME COMES FROM LAKE MICHIGAN. THIS MOISTURE WILL LIKELY
BE ENHANCED BY A SMALL UPSLOPE COMPONENT UNDER WEST NORTHWEST FLOW.
THE NAM AND HYSPLIT BACKWARD TRAJECTORIES SUGGEST THAT MOISTURE
SHOULD COME FROM LAKE MICHIGAN...PLUS LINGERING MOISTURE BEHIND
THE FRONT...COULD PRODUCE PERIODS OF SNOW ACROSS THE NORTH AND
NORTHEAST MOUNTAINS OVERNIGHT TONIGHT. CONTINUED WITH HIGH POPS
ACROSS OUR NORTHEAST QUADRANT FOR TONIGHT.
HOWEVER...MODELS DID NOT DEPICT THE INTENSITY OF PCPN ALONG THE
COLD FRONT TODAY...AS THEY LOOKED OVERDONE. THIS INSERTS SOME
UNCERTAINTY TO THE FORECAST. THEREFORE...CODED UP TO 2 INCHES OF
SNOW OVER THE NORTHEAST MOUNTAINS...EXTENDING WEST TO COVER FEW
COUNTIES WITH LIKELY POPS...AND LOW CHANCE POPS ELSEWHERE.
WINDS SHOULD SUBSIDE SOME TONIGHT RESULTING IN LIGHT TO GENTLE
WEST TO NORTHWEST FLOW.
WENT MAINLY WITH MOS GUIDANCE FOR TEMPERATURES WITH MINOR TWEAKS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
STILL A BIT OF UNCERTAINTY REGARDING MIDWEEK WITH A SERIES OF
DISTURBANCES AND ASSOCIATED BAROCLINIC ZONES DROPPING THRU BROAD
UPPER TROF. FOLLOWED HPC PREFERRED SOLUTION CLOSE TO GFS. MOST
NOTABLE CHANGE FROM PREVIOUS FORECAST WAS TO DELAY ARRIVAL OF POPS
ACROSS THE NW UNTIL TUESDAY AFTERNOON. STILL LOOKS LIKE THE WEAK
SURFACE LOW WILL TRACK ACROSS N WV ON WEDNESDAY WITH SUBSEQUENT
FROPA SWINGING DO THRU REMAINDER OF CWA WEDNESDAY EVENING. HAVE
PRECIP SLOWLY MIXING WITH AND EVENTUALLY CHANGING TO -SN ACROSS THE
AREA WEDNESDAY AFTERNOON AND EVENING WITH THE MOUNTAINS AND SE OH
CHANGING WEDNESDAY MORNING. HAVE SOME MINOR ACCUMULATIONS IN THE
MOUNTAINS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A CLIPPER EXITS THE REGION ON THURSDAY MORNING WITH LIGHT RAIN
AND SNOW SHOWERS DECREASING. AFTER THAT...MODELS DIVERGE ON THE
DETAILS...BUT THEY ALL AGREE THAT THERE IS NOTHING TOO SIGNIFICANT
TO NOTE UNTIL SUNDAY NIGHT WHEN A MORE ORGANIZED SYSTEM APPROACHES
IN A SHARPER UPPER TROUGH. STILL WAY TOO FAR OUT TO PUT ANY WEIGHT
IN THIS. TEMPERATURES APPEAR TO REMAIN SEASONABLE WITH HIGHS IN
THE 40S AND LOWS IN THE 20S IN MOST PLACES.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
COLD FRONT EXITS THE EASTERN MOUNTAINS THIS AFTERNOON LEAVING MVFR
CEILINGS...ABOUT 2200 FEET...AND GUSTY WINDS UP TO 24 KNOTS BEHIND
IT. A SECOND WAVE IN THE MID LEVELS WILL REINFORCE THE COLD AIR
BEHIND THE FRONT AND SQUEEZE LINGERING MOISTURE FURTHER DOWN...TO
1500 FEET OVERNIGHT AT MOST SITES ACCORDING WITH SREF MODEL AND
BUFKIT SOUNDINGS.
EXPECT WINDS TO SUBSIDE AND TURNING MORE FROM THE WEST WITH A
LITTLE COMPONENT FROM THE NORTHWEST TONIGHT...WITH CEILINGS
DROPPING TO LOW MVFR. LIGHT SNOW WILL BE POSSIBLE OVER THE
NORTHEAST MOUNTAINS TO AFFECT EKN AND SURROUNDING AREAS WITH
PERIODS OF IFR. ALTHOUGH CONFIDENCE IS LOW DUE TO A SHALLOW LAYER
OF MOISTURE...DECIDED NOT TO INCLUDE IFR AT EKN AT THIS TIME.
GUIDANCE SUGGESTS IMPROVING CONDITIONS POSSIBLE EARLY MONDAY
MORNING SPREADING FROM SOUTHWEST TO CENTRAL WV WITH SOME CLEARING.
THEREFORE...VFR CONDITIONS COULD PREVAIL MONDAY AT LEAST OVER
HTS...CRW...AND BKW BY MID DAY...AND THE REST OF SITES DURING THE
AFTERNOON HOURS.
CHANCES FOR PCPN INCREASE TUESDAY NIGHT WITH A SERIES OF UPPER
WAVES PASSING BY. TEMPERATURES COULD SUPPORT SNOW ACROSS THE
NORTHERN PORTIONS OF WV INCLUDING THE NORTHEAST MOUNTAINS FOR
PERIODS OF IFR CONDITIONS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: MAY NEED TO ADD RESTRICTIONS IN LIGHT SNOW
AFTER 03Z MONDAY FOR CKB AND EKN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H H H H M H H H H H H H
HTS CONSISTENCY M M M M M M M M M H H H
BKW CONSISTENCY M M M H H H H H H H H L
EKN CONSISTENCY M M M M M L L L M M M H
PKB CONSISTENCY H H H H H H H H H H M M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30/JW
NEAR TERM...ARJ
SHORT TERM...JMV
LONG TERM...JW
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
222 PM EST SUN JAN 18 2015
.SYNOPSIS...
WEAK COLD FRONT EXITS THIS AFTERNOON. RELATIVELY MINOR SYSTEM
IMPACTS AREA ON WEDNESDAY THEN GENERALLY DRY WITH SEASONABLE
TEMPERATURES.
&&
.NEAR TERM /THROUGH MONDAY/...
COLD FRONT EXITS THE EASTERN MOUNTAINS BY SUNSET. MODELS INDICATE
THAT DESCENT COLD AIR ADVECTION BEHIND THE FRONT WILL BEING H85
TEMPERATURES TO MINUS 8C TO SUPPORT SNOW ACROSS THE NORTHERN
SECTIONS OF SOUTHEAST OH AND NORTHERN AND NORTHEAST MOUNTAINS OF
WV TONIGHT. WWD GUIDANCE SUGGESTS 2 TO 4 INCHES OF SNOW POSSIBLE
OVER THE NORTHEAST MOUNTAINS. ALL MODELS SUGGEST SOME PCPN IN
THEIR QPF FIELDS MAINLY ACROSS THE NORTHEAST MOUNTAINS. THE HIGH
RESOLUTION MODELS...WRF AND RUC13 ALSO INDICATE SOME KIND OF
BANDING PCPN MAINLY ACROSS THE NORTHEAST MOUNTAINS AND WESTERN
COUNTIES. THE NAM AND WRF MODELS SHOW SOME INDICATIONS THAT THE
MOISTURE PLUME COMES FROM LAKE MICHIGAN. THIS MOISTURE WILL LIKELY
BE ENHANCED BY A SMALL UPSLOPE COMPONENT UNDER WEST NORTHWEST FLOW.
THE NAM AND HYSPLIT BACKWARD TRAJECTORIES SUGGEST THAT MOISTURE
SHOULD COME FROM LAKE MICHIGAN...PLUS LINGERING MOISTURE BEHIND
THE FRONT...COULD PRODUCE PERIODS OF SNOW ACROSS THE NORTH AND
NORTHEAST MOUNTAINS OVERNIGHT TONIGHT. CONTINUED WITH HIGH POPS
ACROSS OUR NORTHEAST QUADRANT FOR TONIGHT.
HOWEVER...MODELS DID NOT DEPICT THE INTENSITY OF PCPN ALONG THE
COLD FRONT TODAY...AS THEY LOOKED OVERDONE. THIS INSERTS SOME
UNCERTAINTY TO THE FORECAST. THEREFORE...CODED UP TO 2 INCHES OF
SNOW OVER THE NORTHEAST MOUNTAINS...EXTENDING WEST TO COVER FEW
COUNTIES WITH LIKELY POPS...AND LOW CHANCE POPS ELSEWHERE.
WINDS SHOULD SUBSIDE SOME TONIGHT RESULTING IN LIGHT TO GENTLE
WEST TO NORTHWEST FLOW.
WENT MAINLY WITH MOS GUIDANCE FOR TEMPERATURES WITH MINOR TWEAKS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
THIS WILL BE A VERY BUSY AND DIFFICULT NORTHWEST FLOW ALOFT PATTERN
WITH UPPER DISTURBANCES AND ASSOCIATED COLD FRONTS DROPPING
SOUTHEAST THRU THE OHIO VALLEY...WHILE THE MAIN BAROCLINIC ZONE AND
JUICY LOW PRESSURE SYSTEMS REMAIN WELL TO THE SOUTH AND EAST. THIS
IS THEREFORE A RATHER NUISANCE BUT UNSETTLED PATTERN WITH A COOLING
TREND FOR THE MIDDLE AND LATER PART OF THE WORK WEEK...WITH DIFFICULTY
TO FOLLOW AND TIME THESE DISTURBANCES. MODELS HAVE THE MOST
SIGNIFICANT DISTURBANCE WITH ITS ASSOCIATED SURFACE LOW AND COLD
FRONT DROPPING ACROSS TUESDAY AND TUESDAY NIGHT...FOLLOWED BY
REINFORCING COOL SHOTS FOR THE REMAINDER OF THE WORK WEEK. THERE IS
MUCH MODEL DISAGREEMENT ON THE AMPLITUDE OF THE THIS MAIN
DISTURBANCE...AND THEREFORE TRACK/TIMING OF THE ASSOCIATED SURFACE
LOW AND COLD FRONT. MODEL SOLUTIONS FOR THIS SURFACE LOW RANGE FROM
THE SLOWEST AND MOST WELL DEVELOPED CMC SOLUTION THAT TRACKS THE LOW
ACROSS ACROSS SOUTHERN WEST VIRGINIA TUESDAY NIGHT...TO THE FASTEST
EURO WITH A SIMILAR TRACK TO THE CMC BUT LESS DEVELOPED LOW...TO THE
FARTHEST NORTH AND WEAKEST SOLUTION OF THE NAM THAT TRACKS THE LOW
ACROSS THE SOUTHERN GREAT LAKES. THE GFS IS A TRUE MIDDLE GROUND AND
A GOOD COMPROMISE...TAKING A WEAKER LOW ACROSS NORTHERN WEST
VIRGINIA TUESDAY NIGHT AND REDEVELOPING IT EAST OF THE APPALACHIAN
BY WEDNESDAY MORNING. THIS WILL BE FOLLOWED BY COLD ADVECTION
WEDNESDAY AND WEDNESDAY NIGHT IN MOIST NORTHWEST FLOW.
THIS GFS ACCEPTED SOLUTION THEN HAS A WARM FRONT LIFTING NORTHEAST
TUESDAY AHEAD OF THE LOW...FOLLOWED BY THE LOW CUTTING ACROSS
NORTHERN WEST VIRGINIA TUESDAY NIGHT...DRAGGING A COLD FRONT WITH
IT.
MOISTURE IS NOT IMPRESSIVE...WITH THE MAIN STORM TRACK HOGGING
THINGS WELL TO THE SOUTH. BUT FAVORABLE DYNAMICS FROM THE WARM FRONT
AND FOLLOWING SURFACE LOW AND COLD FRONT...AND MOIST COLD ADVECTION
BEHIND IT WILL BRING AN UNSETTLED AND COOLING TREND FOR MID WEEK.
SPECIFICALLY...LOOK FOR SOME LIGHT RAIN DEVELOPING WITH THE WARM
FRONT TUESDAY WITH MILD AIR...THEN A MORE CONCENTRATED AREA OF LIGHT
RAIN TUESDAY NIGHT TRENDING TOWARD A WINTRY MIX LATER TUESDAY NIGHT
AND WEDNESDAY...AND FINALLY SOME LIGHT SNOW WEDNESDAY NIGHT.
HIGHS TUESDAY IN THE 50S WILL BE REPLACED BY HIGHS IN THE 30S
WEDNESDAY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A CLIPPER EXITS THE REGION ON THURSDAY MORNING WITH LIGHT RAIN
AND SNOW SHOWERS DECREASING. AFTER THAT...MODELS DIVERGE ON THE
DETAILS...BUT THEY ALL AGREE THAT THERE IS NOTHING TOO SIGNIFICANT
TO NOTE UNTIL SUNDAY NIGHT WHEN A MORE ORGANIZED SYSTEM APPROACHES
IN A SHARPER UPPER TROUGH. STILL WAY TOO FAR OUT TO PUT ANY WEIGHT
IN THIS. TEMPERATURES APPEAR TO REMAIN SEASONABLE WITH HIGHS IN
THE 40S AND LOWS IN THE 20S IN MOST PLACES.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
COLD FRONT EXITS THE EASTERN MOUNTAINS THIS AFTERNOON LEAVING MVFR
CEILINGS...ABOUT 2200 FEET...AND GUSTY WINDS UP TO 24 KNOTS BEHIND
IT. A SECOND WAVE IN THE MID LEVELS WILL REINFORCE THE COLD AIR
BEHIND THE FRONT AND SQUEEZE LINGERING MOISTURE FURTHER DOWN...TO
1500 FEET OVERNIGHT AT MOST SITES ACCORDING WITH SREF MODEL AND
BUFKIT SOUNDINGS.
EXPECT WINDS TO SUBSIDE AND TURNING MORE FROM THE WEST WITH A
LITTLE COMPONENT FROM THE NORTHWEST TONIGHT...WITH CEILINGS
DROPPING TO LOW MVFR. LIGHT SNOW WILL BE POSSIBLE OVER THE
NORTHEAST MOUNTAINS TO AFFECT EKN AND SURROUNDING AREAS WITH
PERIODS OF IFR. ALTHOUGH CONFIDENCE IS LOW DUE TO A SHALLOW LAYER
OF MOISTURE...DECIDED NOT TO INCLUDE IFR AT EKN AT THIS TIME.
GUIDANCE SUGGESTS IMPROVING CONDITIONS POSSIBLE EARLY MONDAY
MORNING SPREADING FROM SOUTHWEST TO CENTRAL WV WITH SOME CLEARING.
THEREFORE...VFR CONDITIONS COULD PREVAIL MONDAY AT LEAST OVER
HTS...CRW...AND BKW BY MID DAY...AND THE REST OF SITES DURING THE
AFTERNOON HOURS.
CHANCES FOR PCPN INCREASE TUESDAY NIGHT WITH A SERIES OF UPPER
WAVES PASSING BY. TEMPERATURES COULD SUPPORT SNOW ACROSS THE
NORTHERN PORTIONS OF WV INCLUDING THE NORTHEAST MOUNTAINS FOR
PERIODS OF IFR CONDITIONS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: MAY NEED TO ADD RESTRICTIONS IN LIGHT SNOW
AFTER 03Z MONDAY FOR CKB AND EKN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H H H H M H H H H H H H
HTS CONSISTENCY M M M M M M M M M H H H
BKW CONSISTENCY M M M H H H H H H H H L
EKN CONSISTENCY M M M M M L L L M M M H
PKB CONSISTENCY H H H H H H H H H H M M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30/JW
NEAR TERM...ARJ
SHORT TERM...JMV
LONG TERM...JW
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
202 PM EST SUN JAN 18 2015
.SYNOPSIS...
WEAK COLD FRONT EXITS THIS AFTERNOON. UPPER DISTURBANCES MID TO
LATE WEEK IN AN UNSETTLED AND COOLING TREND.
&&
.NEAR TERM /THROUGH MONDAY/...
COLD FRONT EXITS THE EASTERN MOUNTAINS BY SUNSET. MODELS INDICATE
THAT DESCENT COLD AIR ADVECTION BEHIND THE FRONT WILL BEING H85
TEMPERATURES TO MINUS 8C TO SUPPORT SNOW ACROSS THE NORTHERN
SECTIONS OF SOUTHEAST OH AND NORTHERN AND NORTHEAST MOUNTAINS OF
WV TONIGHT. WWD GUIDANCE SUGGESTS 2 TO 4 INCHES OF SNOW POSSIBLE
OVER THE NORTHEAST MOUNTAINS. ALL MODELS SUGGEST SOME PCPN IN
THEIR QPF FIELDS MAINLY ACROSS THE NORTHEAST MOUNTAINS. THE HIGH
RESOLUTION MODELS...WRF AND RUC13 ALSO INDICATE SOME KIND OF
BANDING PCPN MAINLY ACROSS THE NORTHEAST MOUNTAINS AND WESTERN
COUNTIES. THE NAM AND WRF MODELS SHOW SOME INDICATIONS THAT THE
MOISTURE PLUME COMES FROM LAKE MICHIGAN. THIS MOISTURE WILL LIKELY
BE ENHANCED BY A SMALL UPSLOPE COMPONENT UNDER WEST NORTHWEST FLOW.
THE NAM AND HYSPLIT BACKWARD TRAJECTORIES SUGGEST THAT MOISTURE
SHOULD COME FROM LAKE MICHIGAN...PLUS LINGERING MOISTURE BEHIND
THE FRONT...COULD PRODUCE PERIODS OF SNOW ACROSS THE NORTH AND
NORTHEAST MOUNTAINS OVERNIGHT TONIGHT. CONTINUED WITH HIGH POPS
ACROSS OUR NORTHEAST QUADRANT FOR TONIGHT.
HOWEVER...MODELS DID NOT DEPICT THE INTENSITY OF PCPN ALONG THE
COLD FRONT TODAY...AS THEY LOOKED OVERDONE. THIS INSERTS SOME
UNCERTAINTY TO THE FORECAST. THEREFORE...CODED UP TO 2 INCHES OF
SNOW OVER THE NORTHEAST MOUNTAINS...EXTENDING WEST TO COVER FEW
COUNTIES WITH LIKELY POPS...AND LOW CHANCE POPS ELSEWHERE.
WINDS SHOULD SUBSIDE SOME TONIGHT RESULTING IN LIGHT TO GENTLE
WEST TO NORTHWEST FLOW.
WENT MAINLY WITH MOS GUIDANCE FOR TEMPERATURES WITH MINOR TWEAKS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
THIS WILL BE A VERY BUSY AND DIFFICULT NORTHWEST FLOW ALOFT PATTERN
WITH UPPER DISTURBANCES AND ASSOCIATED COLD FRONTS DROPPING
SOUTHEAST THRU THE OHIO VALLEY...WHILE THE MAIN BAROCLINIC ZONE AND
JUICY LOW PRESSURE SYSTEMS REMAIN WELL TO THE SOUTH AND EAST. THIS
IS THEREFORE A RATHER NUISANCE BUT UNSETTLED PATTERN WITH A COOLING
TREND FOR THE MIDDLE AND LATER PART OF THE WORK WEEK...WITH DIFFICULTY
TO FOLLOW AND TIME THESE DISTURBANCES. MODELS HAVE THE MOST
SIGNIFICANT DISTURBANCE WITH ITS ASSOCIATED SURFACE LOW AND COLD
FRONT DROPPING ACROSS TUESDAY AND TUESDAY NIGHT...FOLLOWED BY
REINFORCING COOL SHOTS FOR THE REMAINDER OF THE WORK WEEK. THERE IS
MUCH MODEL DISAGREEMENT ON THE AMPLITUDE OF THE THIS MAIN
DISTURBANCE...AND THEREFORE TRACK/TIMING OF THE ASSOCIATED SURFACE
LOW AND COLD FRONT. MODEL SOLUTIONS FOR THIS SURFACE LOW RANGE FROM
THE SLOWEST AND MOST WELL DEVELOPED CMC SOLUTION THAT TRACKS THE LOW
ACROSS ACROSS SOUTHERN WEST VIRGINIA TUESDAY NIGHT...TO THE FASTEST
EURO WITH A SIMILAR TRACK TO THE CMC BUT LESS DEVELOPED LOW...TO THE
FARTHEST NORTH AND WEAKEST SOLUTION OF THE NAM THAT TRACKS THE LOW
ACROSS THE SOUTHERN GREAT LAKES. THE GFS IS A TRUE MIDDLE GROUND AND
A GOOD COMPROMISE...TAKING A WEAKER LOW ACROSS NORTHERN WEST
VIRGINIA TUESDAY NIGHT AND REDEVELOPING IT EAST OF THE APPALACHIAN
BY WEDNESDAY MORNING. THIS WILL BE FOLLOWED BY COLD ADVECTION
WEDNESDAY AND WEDNESDAY NIGHT IN MOIST NORTHWEST FLOW.
THIS GFS ACCEPTED SOLUTION THEN HAS A WARM FRONT LIFTING NORTHEAST
TUESDAY AHEAD OF THE LOW...FOLLOWED BY THE LOW CUTTING ACROSS
NORTHERN WEST VIRGINIA TUESDAY NIGHT...DRAGGING A COLD FRONT WITH
IT.
MOISTURE IS NOT IMPRESSIVE...WITH THE MAIN STORM TRACK HOGGING
THINGS WELL TO THE SOUTH. BUT FAVORABLE DYNAMICS FROM THE WARM FRONT
AND FOLLOWING SURFACE LOW AND COLD FRONT...AND MOIST COLD ADVECTION
BEHIND IT WILL BRING AN UNSETTLED AND COOLING TREND FOR MID WEEK.
SPECIFICALLY...LOOK FOR SOME LIGHT RAIN DEVELOPING WITH THE WARM
FRONT TUESDAY WITH MILD AIR...THEN A MORE CONCENTRATED AREA OF LIGHT
RAIN TUESDAY NIGHT TRENDING TOWARD A WINTRY MIX LATER TUESDAY NIGHT
AND WEDNESDAY...AND FINALLY SOME LIGHT SNOW WEDNESDAY NIGHT.
HIGHS TUESDAY IN THE 50S WILL BE REPLACED BY HIGHS IN THE 30S
WEDNESDAY.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
NOT MUCH CHANGE...A CLIPPER MOVES IN MID WEEK...SPREADING MORE
LIGHT RAIN AND SNOW SHOWERS BACK INTO THE AREA. AFTER THAT...MODELS
DIVERGE ON THE DETAILS...BUT THEY ALL AGREE THAT THERE IS NOTHING
TOO SIGNIFICANT TO NOTE.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
COLD FRONT EXITS THE EASTERN MOUNTAINS THIS AFTERNOON LEAVING MVFR
CEILINGS...ABOUT 2200 FEET...AND GUSTY WINDS UP TO 24 KNOTS BEHIND
IT. A SECOND WAVE IN THE MID LEVELS WILL REINFORCE THE COLD AIR
BEHIND THE FRONT AND SQUEEZE LINGERING MOISTURE FURTHER DOWN...TO
1500 FEET OVERNIGHT AT MOST SITES ACCORDING WITH SREF MODEL AND
BUFKIT SOUNDINGS.
EXPECT WINDS TO SUBSIDE AND TURNING MORE FROM THE WEST WITH A
LITTLE COMPONENT FROM THE NORTHWEST TONIGHT...WITH CEILINGS
DROPPING TO LOW MVFR. LIGHT SNOW WILL BE POSSIBLE OVER THE
NORTHEAST MOUNTAINS TO AFFECT EKN AND SURROUNDING AREAS WITH
PERIODS OF IFR. ALTHOUGH CONFIDENCE IS LOW DUE TO A SHALLOW LAYER
OF MOISTURE...DECIDED NOT TO INCLUDE IFR AT EKN AT THIS TIME.
GUIDANCE SUGGESTS IMPROVING CONDITIONS POSSIBLE EARLY MONDAY
MORNING SPREADING FROM SOUTHWEST TO CENTRAL WV WITH SOME CLEARING.
THEREFORE...VFR CONDITIONS COULD PREVAIL MONDAY AT LEAST OVER
HTS...CRW...AND BKW BY MID DAY...AND THE REST OF SITES DURING THE
AFTERNOON HOURS.
CHANCES FOR PCPN INCREASE TUESDAY NIGHT WITH A SERIES OF UPPER
WAVES PASSING BY. TEMPERATURES COULD SUPPORT SNOW ACROSS THE
NORTHERN PORTIONS OF WV INCLUDING THE NORTHEAST MOUNTAINS FOR
PERIODS OF IFR CONDITIONS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: MAY NEED TO ADD RESTRICTIONS IN LIGHT SNOW
AFTER 03Z MONDAY FOR CKB AND EKN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY M M M H H H H H H H H H
HTS CONSISTENCY M M H M H H M M M M M H
BKW CONSISTENCY M H H H H H H H H H H H
EKN CONSISTENCY H M M H M M M L L L M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/JMV/26
NEAR TERM...ARJ
SHORT TERM...JMV
LONG TERM...JW
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
850 AM EST SUN JAN 18 2015
.SYNOPSIS...
COLD FRONT PASSES TODAY. UPPER DISTURBANCES MID TO LATE WEEK IN AN
UNSETTLED AND COOLING TREND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
ADJUSTED TIMING OF HIGHER POPS ASSOCIATED WITH COLD FRONT CROSSING
THE AREA. A SECOND BATCH OF PCPN FOLLOWS ENTERING SOUTHEAST OH BY
1330Z...BUT PCPN IS MORE ISOLATED SO KEPT CHANCE POPS WITH THIS
SECOND FEATURE.
PREVIOUS DISCUSSION BELOW...
UPDATE...
SHOWERS ARE LESS THAN AN HOUR AWAY FROM THE FAR WESTERN ZONES IN
SOUTHEAST OHIO AND NORTHEAST KENTUCKY. LINE HAS EXHIBITED SOME
WIND GUSTS AS IT PASSES...SO A 30-35MPH BRIEF GUST CAN BE EXPECTED
AS THE LINE MOVES EASTWARD OVER THE NEXT FEW HOURS.
PREVIOUS DISCUSSION...
USING THE HRRR THIS MORNING FOR THE TIMING OF THE LINE OF SHOWERS
SLATED TO ENTER THE SOUTHEAST OHIO COUNTIES AND NORTHEAST KENTUCKY
AREA BY 12Z. FORCING WILL PEAK OUT RIGHT AROUND THIS TIME AND EXPECT
IT GO FRONTOLYTIC AS IT CROSSES THE OHIO VALLEY INTO WEST VIRGINIA.
STILL CONTINUE TO BE LESS THAN IMPRESSED WITH THE RATE OF THE COLD
AIR ADVECTION OFF THE SURFACE...ESPECIALLY WHEN USING THIS TO
DETERMINE THE TRANSITION TIME FROM RAIN TO SNOW. IN THE END...THIS
WILL NOT BE A QUICK TRANSITION...EVEN IN THE MOUNTAINS...AND ONLY
GET THE -8C CONTOUR INTO OUR CWA AFTER 03Z MONDAY.
ONCE AGAIN...WE ARE LEFT WITH YET ANOTHER IMPERFECT UPSLOPE SCENARIO
FOR TONIGHT AS ALREADY MENTIONED IN TERMS OF THE TEMPERATURES ALOFT.
LOW LEVEL STREAMLINES ARE NEARLY WESTERLY WITHOUT A GREAT MOISTURE
FEED FROM THE GREAT LAKES. THAT BEING SAID...THINK THE BEST TIME FOR
SNOW ACCUMULATIONS IN THE MOUNTAINS WILL BE FROM AROUND 03Z TO 09Z
TONIGHT. THINK A GENERAL 1-2 INCHES IS THE WAY TO GO FOR THIS EVENT
WITH AN ISOLATED 3 INCH TOTAL FOR THE EXPOSED WESTERLY RIDGES.
FOR THE TEMPERATURES DURING THE DAY SUNDAY...HAVE SOME REASONABLY
LOW CONFIDENCE IN TERMS OF A DIURNAL VERSUS NON DIURNAL TREND. SOME
LOCATIONS DURING THE OVERNIGHT PERIOD ACTUALLY WERE ABLE TO
RADIATE...LIKE I16/PINEVILLE AND OTHER SCATTERED LOCATIONS...WHILE
HIGHER POINTS EXPOSED TO WIND HAVE STAYED IN THE 40S. THESE
LOCATIONS MAY BE AT THEIR MAX TEMP FOR THE DAY AS THE SUN RISES
ACROSS SOUTHEAST OHIO. NO CONSENSUS BETWEEN THE MET AND MAV GUIDANCE
NUMBERS TO HELP OUT AND WILL FAVOR THE MET FOR NOW WHICH SUPPORTS
THE DIURNAL TREND.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
THIS WILL BE A VERY BUSY AND DIFFICULT NORTHWEST FLOW ALOFT PATTERN
WITH UPPER DISTURBANCES AND ASSOCIATED COLD FRONTS DROPPING
SOUTHEAST THRU THE OHIO VALLEY...WHILE THE MAIN BAROCLINIC ZONE AND
JUICY LOW PRESSURE SYSTEMS REMAIN WELL TO THE SOUTH AND EAST. THIS
IS THEREFORE A RATHER NUISANCE BUT UNSETTLED PATTERN WITH A COOLING
TREND FOR THE MIDDLE AND LATER PART OF THE WORK WEEK...WITH DIFFICULTY
TO FOLLOW AND TIME THESE DISTURBANCES. MODELS HAVE THE MOST
SIGNIFICANT DISTURBANCE WITH ITS ASSOCIATED SURFACE LOW AND COLD
FRONT DROPPING ACROSS TUESDAY AND TUESDAY NIGHT...FOLLOWED BY
REINFORCING COOL SHOTS FOR THE REMAINDER OF THE WORK WEEK. THERE IS
MUCH MODEL DISAGREEMENT ON THE AMPLITUDE OF THE THIS MAIN
DISTURBANCE...AND THEREFORE TRACK/TIMING OF THE ASSOCIATED SURFACE
LOW AND COLD FRONT. MODEL SOLUTIONS FOR THIS SURFACE LOW RANGE FROM
THE SLOWEST AND MOST WELL DEVELOPED CMC SOLUTION THAT TRACKS THE LOW
ACROSS ACROSS SOUTHERN WEST VIRGINIA TUESDAY NIGHT...TO THE FASTEST
EURO WITH A SIMILAR TRACK TO THE CMC BUT LESS DEVELOPED LOW...TO THE
FARTHEST NORTH AND WEAKEST SOLUTION OF THE NAM THAT TRACKS THE LOW
ACROSS THE SOUTHERN GREAT LAKES. THE GFS IS A TRUE MIDDLE GROUND AND
A GOOD COMPROMISE...TAKING A WEAKER LOW ACROSS NORTHERN WEST
VIRGINIA TUESDAY NIGHT AND REDEVELOPING IT EAST OF THE APPALACHIAN
BY WEDNESDAY MORNING. THIS WILL BE FOLLOWED BY COLD ADVECTION
WEDNESDAY AND WEDNESDAY NIGHT IN MOIST NORTHWEST FLOW.
THIS GFS ACCEPTED SOLUTION THEN HAS A WARM FRONT LIFTING NORTHEAST
TUESDAY AHEAD OF THE LOW...FOLLOWED BY THE LOW CUTTING ACROSS
NORTHERN WEST VIRGINIA TUESDAY NIGHT...DRAGGING A COLD FRONT WITH
IT.
MOISTURE IS NOT IMPRESSIVE...WITH THE MAIN STORM TRACK HOGGING
THINGS WELL TO THE SOUTH. BUT FAVORABLE DYNAMICS FROM THE WARM FRONT
AND FOLLOWING SURFACE LOW AND COLD FRONT...AND MOIST COLD ADVECTION
BEHIND IT WILL BRING AN UNSETTLED AND COOLING TREND FOR MID WEEK.
SPECIFICALLY...LOOK FOR SOME LIGHT RAIN DEVELOPING WITH THE WARM
FRONT TUESDAY WITH MILD AIR...THEN A MORE CONCENTRATED AREA OF LIGHT
RAIN TUESDAY NIGHT TRENDING TOWARD A WINTRY MIX LATER TUESDAY NIGHT
AND WEDNESDAY...AND FINALLY SOME LIGHT SNOW WEDNESDAY NIGHT.
HIGHS TUESDAY IN THE 50S WILL BE REPLACED BY HIGHS IN THE 30S
WEDNESDAY.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
NOT MUCH CHANGE...A CLIPPER MOVES IN MID WEEK...SPREADING MORE
LIGHT RAIN AND SNOW SHOWERS BACK INTO THE AREA. AFTER THAT...MODELS
DIVERGE ON THE DETAILS...BUT THEY ALL AGREE THAT THERE IS NOTHING
TOO SIGNIFICANT TO NOTE.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
LINE OF SHOWERS WILL BE AT PKB/HTS AROUND THE 12Z MARK WITH THE
NEXT TAF ISSUANCE. LINE HAS A HISTORY OF 25-20KT GUSTS...SO HAVE
ADDED THAT TO THE TAFS FROM THE PREVIOUS RUN. ALSO CHANGED WAS THE
TIMING BY AN HOUR OR TWO AND MOVED IT UP...ALONG WITH THE
ELIMINATION OF IFR VISIBILITIES IN RAIN. LINE IS NOT VERY INTENSE
AND SHOULD MOVE QUICKLY THROUGH THE LOWLAND TERMINALS THIS
MORNING.
KEEP CEILINGS MVFR IN THE WAKE OF THE FRONT. COLD AIR ADVECTION
WITH WINDS VEERING TO THE WEST NORTHWEST PAVES THE WAY FOR LIGHT
UPSLOPE SNOW TONIGHT AND HAVE THIS HIGHLIGHTED IN THE CKB/EKN/BKW
TAFS. IFR EXPECTED IN SNOW AT TIMES AND USE THIS IN PREVAILING
CONDITIONS. LIGHT SNOW EXPECTED ELSEWHERE AT PKB AND CRW BUT
CHANCES ARE TOO LOW FOR ANY PREVAILING RESTRICTIONS AT THESE
LOCATIONS. THIS COULD CHANGE WITH THE 18Z ISSUANCE LATER TODAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: BRIEF IFR IN THE RAIN THIS MORNING CANNOT BE
FULLY DISCOUNTED...EVEN THOUGH GUIDANCE DOES NOT SUPPORT THIS. MAY
NEED TO ADD RESTRICTIONS IN LIGHT SNOW AFTER 00Z MONDAY FOR CRW
AND PKB.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H M H H H H H H H
HTS CONSISTENCY M M M M H M M M H H H H
BKW CONSISTENCY H H H H M M M H H H H H
EKN CONSISTENCY H H H M M M H H H H H H
PKB CONSISTENCY H M H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z MONDAY...
IFR CONDITIONS POSSIBLE LATE SUNDAY NIGHT INTO MONDAY IN LIGHT
RAIN AND SNOW SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...JW
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
533 AM EST SUN JAN 18 2015
.SYNOPSIS...
COLD FRONT PASSES TODAY. UPPER DISTURBANCES MID TO LATE WEEK IN AN
UNSETTLED AND COOLING TREND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
SHOWERS ARE LESS THAN AN HOUR AWAY FROM THE FAR WESTERN ZONES IN
SOUTHEAST OHIO AND NORTHEAST KENTUCKY. LINE HAS EXHIBITED SOME
WIND GUSTS AS IT PASSES...SO A 30-35MPH BRIEF GUST CAN BE EXPECTED
AS THE LINE MOVES EASTWARD OVER THE NEXT FEW HOURS.
PREVIOUS DISCUSSION...
USING THE HRRR THIS MORNING FOR THE TIMING OF THE LINE OF SHOWERS
SLATED TO ENTER THE SOUTHEAST OHIO COUNTIES AND NORTHEAST KENTUCKY
AREA BY 12Z. FORCING WILL PEAK OUT RIGHT AROUND THIS TIME AND EXPECT
IT GO FRONTOLYTIC AS IT CROSSES THE OHIO VALLEY INTO WEST VIRGINIA.
STILL CONTINUE TO BE LESS THAN IMPRESSED WITH THE RATE OF THE COLD
AIR ADVECTION OFF THE SURFACE...ESPECIALLY WHEN USING THIS TO
DETERMINE THE TRANSITION TIME FROM RAIN TO SNOW. IN THE END...THIS
WILL NOT BE A QUICK TRANSITION...EVEN IN THE MOUNTAINS...AND ONLY
GET THE -8C CONTOUR INTO OUR CWA AFTER 03Z MONDAY.
ONCE AGAIN...WE ARE LEFT WITH YET ANOTHER IMPERFECT UPSLOPE SCENARIO
FOR TONIGHT AS ALREADY MENTIONED IN TERMS OF THE TEMPERATURES ALOFT.
LOW LEVEL STREAMLINES ARE NEARLY WESTERLY WITHOUT A GREAT MOISTURE
FEED FROM THE GREAT LAKES. THAT BEING SAID...THINK THE BEST TIME FOR
SNOW ACCUMULATIONS IN THE MOUNTAINS WILL BE FROM AROUND 03Z TO 09Z
TONIGHT. THINK A GENERAL 1-2 INCHES IS THE WAY TO GO FOR THIS EVENT
WITH AN ISOLATED 3 INCH TOTAL FOR THE EXPOSED WESTERLY RIDGES.
FOR THE TEMPERATURES DURING THE DAY SUNDAY...HAVE SOME REASONABLY
LOW CONFIDENCE IN TERMS OF A DIURNAL VERSUS NON DIURNAL TREND. SOME
LOCATIONS DURING THE OVERNIGHT PERIOD ACTUALLY WERE ABLE TO
RADIATE...LIKE I16/PINEVILLE AND OTHER SCATTERED LOCATIONS...WHILE
HIGHER POINTS EXPOSED TO WIND HAVE STAYED IN THE 40S. THESE
LOCATIONS MAY BE AT THEIR MAX TEMP FOR THE DAY AS THE SUN RISES
ACROSS SOUTHEAST OHIO. NO CONSENSUS BETWEEN THE MET AND MAV GUIDANCE
NUMBERS TO HELP OUT AND WILL FAVOR THE MET FOR NOW WHICH SUPPORTS
THE DIURNAL TREND.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
THIS WILL BE A VERY BUSY AND DIFFICULT NORTHWEST FLOW ALOFT PATTERN
WITH UPPER DISTURBANCES AND ASSOCIATED COLD FRONTS DROPPING
SOUTHEAST THRU THE OHIO VALLEY...WHILE THE MAIN BAROCLINIC ZONE AND
JUICY LOW PRESSURE SYSTEMS REMAIN WELL TO THE SOUTH AND EAST. THIS
IS THEREFORE A RATHER NUISANCE BUT UNSETTLED PATTERN WITH A COOLING
TREND FOR THE MIDDLE AND LATER PART OF THE WORK WEEK...WITH DIFFICULTY
TO FOLLOW AND TIME THESE DISTURBANCES. MODELS HAVE THE MOST
SIGNIFICANT DISTURBANCE WITH ITS ASSOCIATED SURFACE LOW AND COLD
FRONT DROPPING ACROSS TUESDAY AND TUESDAY NIGHT...FOLLOWED BY
REINFORCING COOL SHOTS FOR THE REMAINDER OF THE WORK WEEK. THERE IS
MUCH MODEL DISAGREEMENT ON THE AMPLITUDE OF THE THIS MAIN
DISTURBANCE...AND THEREFORE TRACK/TIMING OF THE ASSOCIATED SURFACE
LOW AND COLD FRONT. MODEL SOLUTIONS FOR THIS SURFACE LOW RANGE FROM
THE SLOWEST AND MOST WELL DEVELOPED CMC SOLUTION THAT TRACKS THE LOW
ACROSS ACROSS SOUTHERN WEST VIRGINIA TUESDAY NIGHT...TO THE FASTEST
EURO WITH A SIMILAR TRACK TO THE CMC BUT LESS DEVELOPED LOW...TO THE
FARTHEST NORTH AND WEAKEST SOLUTION OF THE NAM THAT TRACKS THE LOW
ACROSS THE SOUTHERN GREAT LAKES. THE GFS IS A TRUE MIDDLE GROUND AND
A GOOD COMPROMISE...TAKING A WEAKER LOW ACROSS NORTHERN WEST
VIRGINIA TUESDAY NIGHT AND REDEVELOPING IT EAST OF THE APPALACHIAN
BY WEDNESDAY MORNING. THIS WILL BE FOLLOWED BY COLD ADVECTION
WEDNESDAY AND WEDNESDAY NIGHT IN MOIST NORTHWEST FLOW.
THIS GFS ACCEPTED SOLUTION THEN HAS A WARM FRONT LIFTING NORTHEAST
TUESDAY AHEAD OF THE LOW...FOLLOWED BY THE LOW CUTTING ACROSS
NORTHERN WEST VIRGINIA TUESDAY NIGHT...DRAGGING A COLD FRONT WITH
IT.
MOISTURE IS NOT IMPRESSIVE...WITH THE MAIN STORM TRACK HOGGING
THINGS WELL TO THE SOUTH. BUT FAVORABLE DYNAMICS FROM THE WARM FRONT
AND FOLLOWING SURFACE LOW AND COLD FRONT...AND MOIST COLD ADVECTION
BEHIND IT WILL BRING AN UNSETTLED AND COOLING TREND FOR MID WEEK.
SPECIFICALLY...LOOK FOR SOME LIGHT RAIN DEVELOPING WITH THE WARM
FRONT TUESDAY WITH MILD AIR...THEN A MORE CONCENTRATED AREA OF LIGHT
RAIN TUESDAY NIGHT TRENDING TOWARD A WINTRY MIX LATER TUESDAY NIGHT
AND WEDNESDAY...AND FINALLY SOME LIGHT SNOW WEDNESDAY NIGHT.
HIGHS TUESDAY IN THE 50S WILL BE REPLACED BY HIGHS IN THE 30S
WEDNESDAY.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
NOT MUCH CHANGE...A CLIPPER MOVES IN MID WEEK...SPREADING MORE
LIGHT RAIN AND SNOW SHOWERS BACK INTO THE AREA. AFTER THAT...MODELS
DIVERGE ON THE DETAILS...BUT THEY ALL AGREE THAT THERE IS NOTHING
TOO SIGNIFICANT TO NOTE.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
LINE OF SHOWERS WILL BE AT PKB/HTS AROUND THE 12Z MARK WITH THE
NEXT TAF ISSUANCE. LINE HAS A HISTORY OF 25-20KT GUSTS...SO HAVE
ADDED THAT TO THE TAFS FROM THE PREVIOUS RUN. ALSO CHANGED WAS THE
TIMING BY AN HOUR OR TWO AND MOVED IT UP...ALONG WITH THE
ELIMINATION OF IFR VISIBILITIES IN RAIN. LINE IS NOT VERY INTENSE
AND SHOULD MOVE QUICKLY THROUGH THE LOWLAND TERMINALS THIS
MORNING.
KEEP CEILINGS MVFR IN THE WAKE OF THE FRONT. COLD AIR ADVECTION
WITH WINDS VEERING TO THE WEST NORTHWEST PAVES THE WAY FOR LIGHT
UPSLOPE SNOW TONIGHT AND HAVE THIS HIGHLIGHTED IN THE CKB/EKN/BKW
TAFS. IFR EXPECTED IN SNOW AT TIMES AND USE THIS IN PREVAILING
CONDITIONS. LIGHT SNOW EXPECTED ELSEWHERE AT PKB AND CRW BUT
CHANCES ARE TOO LOW FOR ANY PREVAILING RESTRICTIONS AT THESE
LOCATIONS. THIS COULD CHANGE WITH THE 18Z ISSUANCE LATER TODAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: BRIEF IFR IN THE RAIN THIS MORNING CANNOT BE
FULLY DISCOUNTED...EVEN THOUGH GUIDANCE DOES NOT SUPPORT THIS. MAY
NEED TO ADD RESTRICTIONS IN LIGHT SNOW AFTER 00Z MONDAY FOR CRW
AND PKB.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H M H H H H
HTS CONSISTENCY H H H M M M M M H H H H
BKW CONSISTENCY H M M H H H H M M M M H
EKN CONSISTENCY H H H H H H M M M M H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z MONDAY...
IFR CONDITIONS POSSIBLE LATE SUNDAY NIGHT INTO MONDAY IN LIGHT
RAIN AND SNOW SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...JW
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
414 AM EST SUN JAN 18 2015
.SYNOPSIS...
COLD FRONT PASSES TODAY. UPPER DISTURBANCES MID TO LATE WEEK IN AN
UNSETTLED AND COOLING TREND.
&&
.NEAR TERM /THROUGH TONIGHT/...
USING THE HRRR THIS MORNING FOR THE TIMING OF THE LINE OF SHOWERS
SLATED TO ENTER THE SOUTHEAST OHIO COUNTIES AND NORTHEAST KENTUCKY
AREA BY 12Z. FORCING WILL PEAK OUT RIGHT AROUND THIS TIME AND EXPECT
IT GO FRONTOLYTIC AS IT CROSSES THE OHIO VALLEY INTO WEST VIRGINIA.
STILL CONTINUE TO BE LESS THAN IMPRESSED WITH THE RATE OF THE COLD
AIR ADVECTION OFF THE SURFACE...ESPECIALLY WHEN USING THIS TO
DETERMINE THE TRANSITION TIME FROM RAIN TO SNOW. IN THE END...THIS
WILL NOT BE A QUICK TRANSITION...EVEN IN THE MOUNTAINS...AND ONLY
GET THE -8C CONTOUR INTO OUR CWA AFTER 03Z MONDAY.
ONCE AGAIN...WE ARE LEFT WITH YET ANOTHER IMPERFECT UPSLOPE SCENARIO
FOR TONIGHT AS ALREADY MENTIONED IN TERMS OF THE TEMPERATURES ALOFT.
LOW LEVEL STREAMLINES ARE NEARLY WESTERLY WITHOUT A GREAT MOISTURE
FEED FROM THE GREAT LAKES. THAT BEING SAID...THINK THE BEST TIME FOR
SNOW ACCUMULATIONS IN THE MOUNTAINS WILL BE FROM AROUND 03Z TO 09Z
TONIGHT. THINK A GENERAL 1-2 INCHES IS THE WAY TO GO FOR THIS EVENT
WITH AN ISOLATED 3 INCH TOTAL FOR THE EXPOSED WESTERLY RIDGES.
FOR THE TEMPERATURES DURING THE DAY SUNDAY...HAVE SOME REASONABLY
LOW CONFIDENCE IN TERMS OF A DIURNAL VERSUS NON DIURNAL TREND. SOME
LOCATIONS DURING THE OVERNIGHT PERIOD ACTUALLY WERE ABLE TO
RADIATE...LIKE I16/PINEVILLE AND OTHER SCATTERED LOCATIONS...WHILE
HIGHER POINTS EXPOSED TO WIND HAVE STAYED IN THE 40S. THESE
LOCATIONS MAY BE AT THEIR MAX TEMP FOR THE DAY AS THE SUN RISES
ACROSS SOUTHEAST OHIO. NO CONSENSUS BETWEEN THE MET AND MAV GUIDANCE
NUMBERS TO HELP OUT AND WILL FAVOR THE MET FOR NOW WHICH SUPPORTS
THE DIURNAL TREND.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
THIS WILL BE A VERY BUSY AND DIFFICULT NORTHWEST FLOW ALOFT PATTERN
WITH UPPER DISTURBANCES AND ASSOCIATED COLD FRONTS DROPPING
SOUTHEAST THRU THE OHIO VALLEY...WHILE THE MAIN BAROCLINIC ZONE AND
JUICY LOW PRESSURE SYSTEMS REMAIN WELL TO THE SOUTH AND EAST. THIS
IS THEREFORE A RATHER NUISANCE BUT UNSETTLED PATTERN WITH A COOLING
TREND FOR THE MIDDLE AND LATER PART OF THE WORK WEEK...WITH DIFFICULTY
TO FOLLOW AND TIME THESE DISTURBANCES. MODELS HAVE THE MOST
SIGNIFICANT DISTURBANCE WITH ITS ASSOCIATED SURFACE LOW AND COLD
FRONT DROPPING ACROSS TUESDAY AND TUESDAY NIGHT...FOLLOWED BY
REINFORCING COOL SHOTS FOR THE REMAINDER OF THE WORK WEEK. THERE IS
MUCH MODEL DISAGREEMENT ON THE AMPLITUDE OF THE THIS MAIN
DISTURBANCE...AND THEREFORE TRACK/TIMING OF THE ASSOCIATED SURFACE
LOW AND COLD FRONT. MODEL SOLUTIONS FOR THIS SURFACE LOW RANGE FROM
THE SLOWEST AND MOST WELL DEVELOPED CMC SOLUTION THAT TRACKS THE LOW
ACROSS ACROSS SOUTHERN WEST VIRGINIA TUESDAY NIGHT...TO THE FASTEST
EURO WITH A SIMILAR TRACK TO THE CMC BUT LESS DEVELOPED LOW...TO THE
FARTHEST NORTH AND WEAKEST SOLUTION OF THE NAM THAT TRACKS THE LOW
ACROSS THE SOUTHERN GREAT LAKES. THE GFS IS A TRUE MIDDLE GROUND AND
A GOOD COMPROMISE...TAKING A WEAKER LOW ACROSS NORTHERN WEST
VIRGINIA TUESDAY NIGHT AND REDEVELOPING IT EAST OF THE APPALACHIAN
BY WEDNESDAY MORNING. THIS WILL BE FOLLOWED BY COLD ADVECTION
WEDNESDAY AND WEDNESDAY NIGHT IN MOIST NORTHWEST FLOW.
THIS GFS ACCEPTED SOLUTION THEN HAS A WARM FRONT LIFTING NORTHEAST
TUESDAY AHEAD OF THE LOW...FOLLOWED BY THE LOW CUTTING ACROSS
NORTHERN WEST VIRGINIA TUESDAY NIGHT...DRAGGING A COLD FRONT WITH
IT.
MOISTURE IS NOT IMPRESSIVE...WITH THE MAIN STORM TRACK HOGGING
THINGS WELL TO THE SOUTH. BUT FAVORABLE DYNAMICS FROM THE WARM FRONT
AND FOLLOWING SURFACE LOW AND COLD FRONT...AND MOIST COLD ADVECTION
BEHIND IT WILL BRING AN UNSETTLED AND COOLING TREND FOR MID WEEK.
SPECIFICALLY...LOOK FOR SOME LIGHT RAIN DEVELOPING WITH THE WARM
FRONT TUESDAY WITH MILD AIR...THEN A MORE CONCENTRATED AREA OF LIGHT
RAIN TUESDAY NIGHT TRENDING TOWARD A WINTRY MIX LATER TUESDAY NIGHT
AND WEDNESDAY...AND FINALLY SOME LIGHT SNOW WEDNESDAY NIGHT.
HIGHS TUESDAY IN THE 50S WILL BE REPLACED BY HIGHS IN THE 30S
WEDNESDAY.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
NOT MUCH CHANGE...A CLIPPER MOVES IN MID WEEK...SPREADING MORE
LIGHT RAIN AND SNOW SHOWERS BACK INTO THE AREA. AFTER THAT...MODELS
DIVERGE ON THE DETAILS...BUT THEY ALL AGREE THAT THERE IS NOTHING
TOO SIGNIFICANT TO NOTE.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
COLD FRONT COMING THROUGH THE AREA WILL BRING A LINE OF SHOWERS
AND WINDS VEERING TO THE WEST WITH GUSTS IN THE 15 TO 20 KNOT
RANGE...ESPECIALLY IN THE HIGHER ELEVATIONS.
BIGGEST QUESTION IS MVFR OR IFR VISIBILITIES IN THE TAFS. FIGURE
THE BEST CHANCES FOR IFR WILL BE AT PKB AND POSSIBLY HTS LATER
THIS MORNING AS THE FRONT MOVES IN FROM THE WEST. LINE SHOULD
WEAKEN AS IT ADVANCES TO THE EAST...AND WILL RIDE MVFR CONDITIONS
AS IT PASSES THROUGH CKB/CRW AND FINALLY INTO EKN/BKW AFTER 15Z.
WILL BE A QUICK MOVER AND ALSO BRING MVFR CEILINGS WITH THE
SHOWERS AND IN THE WAKE OF THE FRONT.
UPSLOPE SNOW POTENTIAL EXISTS AFTER 00Z MONDAY WHEN THE
TEMPERATURE DROPS BELOW FREEZING...AND SHOULD SEE IFR SNOW LATE AT
CKB AND EKN TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY...
FORECAST CONFIDENCE: HIGH OVERNIGHT...MEDIUM SUNDAY.
ALTERNATE SCENARIO: TIMING OF THE PRECIPITATION BAND AND
RESTRICTIONS ON SUNDAY COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN 01/18/15
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H M M H H H H
HTS CONSISTENCY H H H H H M H M M H H H
BKW CONSISTENCY H H H H M M H H H H M M
EKN CONSISTENCY H H H H H H H H H H H M
PKB CONSISTENCY H H H H H H M M H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z MONDAY...
IFR CONDITIONS POSSIBLE LATE SUNDAY NIGHT INTO MONDAY IN LIGHT
RAIN AND SNOW SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...JW
AVIATION...26
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
1134 PM PST SAT JAN 17 2015
.SYNOPSIS...A WARM FRONT WILL CONTINUE TO MOVE SLOWLY N INTO
WASHINGTON OVERNIGHT. A COLD FRONT WILL MOVE ASHORE A LITTLE BEFORE
MIDNIGHT...AND THEN REACH THE CASCADES OVERNIGHT. A COUPLE OF
UPPER LEVEL DISTURBANCES WILL MOVE ACROSS THE REGION SUNDAY. HIGH
PRESSURE STARTS TO BUILD OVER THE AREA MON. HIGHER PRESSURE DEVELOPS
OVER EXTREME ERN WASHINGTON AND OREGON TUESDAY RESULTING IN THE
RETURN OF OFFSHORE LOW-LEVEL FLOW. THIS PATTERN SHOULD HOLD WEDNESDAY
AND THURSDAY.
&&
.UPDATE...THE COLD FRONT HAS MOVED ACROSS THE REGION AND IS CURRENTLY
MOVING ACROSS THE CASCADES FOOTHILLS. THE WINDS ARE DECREASING BEHIND
THE FRONT AND HAVE CANCELLED THE HIGH WIND WARNING FOR THE BEACHES
AND HEADLANDS. GUSTY WINDS WILL CONTINUE THROUGH SUNDAY MORNING...BUT
THE INTENSITY OF THE GUSTS WILL BE ON A DOWNWARD TREND. THE RAIN HAS
BECOME MORE SHOWERY BEHIND THE FRONT WITH A DECREASE IN RAIN
RATES...BUT STILL EXPECT OCCASSIONAL HEAVY SHOWERS THROUGH THE NIGHT.
TJ
.PREVIOUS SHORT TERM...A WARM FRONT CONTINUES TO GRADUALLY DRIFT N
OVER THE AREA THIS EVENING. THE WARMER AIR HAD REACHED THE WEST SIDE
OF THE N WILLAMETTE VALLEY AS OF 03Z...WITH KHIO AT 55 DEG. COOLER
AIR REMAINED TRAPPED ON THE EAST SIDE OF THE N VALLEY WITH TEMPS IN
THE MID TO UPPER 40S. KTTD-KDLS GRADIENT WAS AT -5.5 MB JUST BEFORE
04Z WITH GUSTS TO 25 MPH AT KTTD. KRTX DUAL-POL DOPPLER RADAR SHOWING
HEAVIER RETURNS ALONG THE COAST ASSOCIATED WITH THE LEADING EDGE OF
THE COLD FRONT. INFRA-RED SATELLITE LOOP WITH NAM 12 SFC PRES
OVERLAID SHOWED A NEAR 990 MB LOW PRES CENTER AT 47N 129W MOVING TO
THE NE. TRAILING END OF THE COLD FRONT LOOKED TO BE NEAR 125W AT
0330Z. FRONT MAY MOVE ASHORE A LITTLE QUICKER THAN THE NAM INDICATED.
KRTX VELOCITY DISPLAY INDICATED 60-65 KT S-SW WIND ABOUT 5000 FT MSL.
STRONGEST WIND GUSTS EARLY THIS EVENING HAVE BEEN AT GARIBALDI...
AROUND 55 MPH...WITH A COUPLE ISOLATED GUSTS 55 TO 60 MPH. THE PEAK
WIND PERIOD STILL LOOKS TO BE THROUGH ABOUT 07Z.
SOME RATHER IMPRESSIVE RAINFALL TOTALS FOR PORTIONS OF THE N OREGON
CASCADES AND IN THE OREGON COAST RANGE. NEARLY 3.5 INCHES OF RAIN HAD
FALLEN AT THE 5880 FT TIMBERLINE SENSOR...WITH RAINFALL RATES UP TO
0.5 INCHES PER HR THIS AFTERNOON. AROUND 1.5 TO 3 INCHES HAVE FALLEN
IN THE OREGON COAST RANGE. FORTUNATELY...THE HEAVIER RAIN RATES HAVE
PUSHED INTO WASHINGTON. THERE WILL BE ANOTHER 3-6 HR PERIOD TONIGHT
OF HEAVIER RAINFALL WITH THE COLD FRONT. ADDED A SLIGHT CHANCE OF
TSTMS FOR THE COASTAL WATERS 03Z-06Z AS THE HRRR MODEL WAS HINTING AT
THE POTENTIAL FOR POTENTIAL CONVECTIVE DEVELOPMENT ALONG THE COLD
FRONTAL BOUNDARY AS IT MOVED TOWARD THE COASTLINE. DID NOT INCLUDE
THE COASTAL ZONES AT THIS TIME. NAMM SOUNDING FOR KAST NOT ALL THAT
IMPRESSIVE WITH CONVECTIVE POSSIBILITIES...BUT SOMETHING THAT WILL
NEED TO BE CLOSELY MONITORED AS THE FRONT MOVES ASHORE.
ONCE THE COLD FRONT MOVES INLAND...AIR MASS TRANSITIONS TO A COOLER
MORE UNSTABLE AIR MASS. MODEL SOUNDINGS INDICATE THE POST FRONTAL
UNSTABLE LAYER IS LIMITED VERTICALLY BY SOME SUBSIDENCE ALOFT...SO
CONVECTION IS NOT EXPECTED TO BE TERRIBLY DEEP...PROBABLY UP TO
AROUND 15K FT. A SERIES OF SHORTWAVES ON SUN WILL PROVIDE SOME
DYNAMIC LIFT FOR POST FRONTAL SHOWERS...WITH OROGRAPHIC LIFT AIDING
THE WINDWARD SIDE OF MOUNTAINS. WEST FLOW ALOFT COMING IN OFF THE
PACIFIC WILL KEEP SNOW LEVELS ELEVATED A BIT...BUT BY LATE SUN ENOUGH
COOLING OCCURS TO DROP THE SNOW LEVEL DOWN BELOW MOST CASCADE PASSES.
CHANCES FOR SHOWERS WILL DROP OFF FROM S TO N SUN NIGHT INTO MON AS A
SURFACE HIGH BUILDS NORTHWARD. MODELS CONTINUE TO SHOW SOME DEGREE OF
THERMALLY-INDUCED SURFACE TROUGHING ALONG THE COAST MON NIGHT AND
TUE. COUPLED WITH STRENGTHENING HIGH PRES OVER THE NRN ROCKIES
CONFIDENCE IS HIGH THAT OFFSHORE LOW-LEVEL FLOW WILL RETURN MON NIGHT
AND PERSIST TUE. WEISHAAR
.LONG TERM...MODELS IN PRETTY GOOD AGREEMENT IN BEGINNING THE
EXTENDED PERIOD WITH AN UPPER RIDGE AT MID WEEK...WHICH SHOULD
RESULT IN DRY WEATHER BUT WITH PLENTY OF VALLEY FOG UNDER A
SUBSIDENCE INVERSION. MODELS AGREE IN WEAKENING THE RIDGE THU AND
FRI...ALTHOUGH HEIGHTS REMAIN HIGH. LOOKS LIKE WHATEVER SYSTEMS
BREAK THROUGH WILL BE ON THE WEAK SIDE...SO OVERALL WILL TEND TO
KEEP POPS ON THE LOW SIDE...PEAKING WITH SOME LIKELY POPS ACROSS THE
N ON FRI WHEN MODELS APPEAR TO BE IN BEST AGREEMENT WITH RAIN
POTENTIAL. WILL THEN TREND BACK TO DRIER CONDITIONS FOR NEXT WEEKEND
AS BOTH GFS AND ECMWF SUGGESTING A STRENGTHENING RIDGE AGAIN.
&&
.AVIATION...COASTAL SITES REMAINING MVFR WITH WINDS GUSTING TO 40
KTS AT KONP. EXPECT WINDS TO RAMP UP TO GUSTS NEAR 50 KT JUST
AHEAD OF FRONTAL PASSAGE. INTERIOR VALLEY SITES PRIMARILY
MVFR...WITH OCCASIONAL BREAKS TO VFR CIGS AS WINDS ARE RAMPING UP
OUT OF THE SOUTH. SO FAR KPDX AND KTTD STILL HAVE SOLID EASTERLY
WINDS WITH A TTD-DLS GRADIENT OF -4.6 KEEPING WINDS OUT OF THE
EAST. AS THE WARM FRONT PUSHES FURTHER NORTH OVER THE NEXT COUPLE
HOURS...EXPECT WINDS TO TURN SOUTHERLY AND RAMP UP LATER TONIGHT.
UNTIL THEN...WIND SHEAR OF 30-35 KTS FROM SFC TO FL020 IS BEING
OBSERVED VIA AMDAR SOUNDING DATA OUT OF PDX...WITH EASTERLY WINDS
AT THE SURFACE AND SOUTHERLY WINDS ALOFT. EXPECT MVFR CONDITIONS
TO CONTINUE AT INTERIOR VALLEY SITES UNTIL THE COLD FRONT MOVES
THROUGH AROUND 9-10Z. WINDS WILL EASE BEHIND THE FRONT...VEERING
WINDS MORE WESTERLY BY DAYBREAK SUNDAY. CIGS MAY RISE A LITTLE AT
THIS TIME...BUT STAY SOMEWHERE BETWEEN 015 AND 025 AGL. EXCEPTIONS
WILL LIKELY BE KONP AND KEUG WHERE IFR COULD PREVAIL ALL DAY.
KPDX AND APPROACHES...MVFR CONDITIONS TO CONTINUE THROUGH MOST OF
TONIGHT...WITH LLWS UNTIL WINDS VEER TO SOUTH AROUND 06Z. WINDS
AFTER 06Z WILL INCREASE TO 20 TO 25 KT WITH GUSTS NEAR 35 KT
LIKELY. WINDS EASE AFTER 09Z BEHIND COLD FRONT...FALLING BELOW 20
KT BY 10Z. CIGS LIFT SOME AROUND 12-14Z...BUT LIKELY WILL STAY
BELOW FL040 ALL DAY THUS LIMITING VISUAL APPROACHES. -MCCOY/JBONK
&&
.MARINE...WINDS AROUND 30 KT GUSTING TO 40 KT AT BUOY 29.
SOUTHERLY WINDS LIKELY WILL CONTINUE TO INCREASE...GUSTING TO 45 KT
AS FRONT APPROACHES THE COAST. SEAS NOT INCREASING AT RATE
EXPECTED...SO SEAS LIKELY TO PEAK A BIT LOWER AROUND 16 FT AFTER
MIDNIGHT...AND STAY UP IN THE LOW TO MIDDLE TEENS THROUGH SUNDAY.
WINDS VEER TO THE WEST-SOUTHWEST EARLY SUNDAY BEHIND THE
FRONT...AND REMAIN ABOVE 20 KT IN THE NORTHERN WATERS THROUGH MOST
OF THE DAY. WINDS LOOK TO WEAKEN OVER SOUTHERN WATERS SUNDAY
MORNING...DROPPING BELOW 20 KTS BY THE AFTERNOON.
HIGH PRESSURE BUILDS IN LATE SUNDAY BEHIND THE FRONT...STAYING IN
PLACE THROUGH EARLY THIS WEEK. THIS WILL ALLOW SEAS TO GRADUALLY
SUBSIDE UNTIL DROPPING BELOW 10 FT TUESDAY. -MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE
WA...NONE
PZ...GALE WARNING UNTIL 7 AM PST SUNDAY FOR COASTAL WATERS FROM CAPE
SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM.
GALE WARNING UNTIL 4 AM PST SUNDAY FOR COASTAL WATERS FROM
CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM
PST SUNDAY.
&&
$$
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
902 PM PST SAT JAN 17 2015
.SYNOPSIS...A WARM FRONT WILL CONTINUE TO MOVE SLOWLY N INTO
WASHINGTON OVERNIGHT. A COLD FRONT WILL MOVE ASHORE A LITTLE BEFORE
MIDNIGHT...AND THEN REACH THE CASCADES OVERNIGHT. A COUPLE OF
UPPER LEVEL DISTURBANCES WILL MOVE ACROSS THE REGION SUNDAY. HIGH
PRESSURE STARTS TO BUILD OVER THE AREA MON. HIGHER PRESSURE DEVELOPS
OVER EXTREME ERN WASHINGTON AND OREGON TUESDAY RESULTING IN THE
RETURN OF OFFSHORE LOW-LEVEL FLOW. THIS PATTERN SHOULD HOLD WEDNESDAY
AND THURSDAY.
&&
.SHORT TERM...A WARM FRONT CONTINUES TO GRADUALLY DRIFT N OVER THE
AREA THIS EVENING. THE WARMER AIR HAD REACHED THE WEST SIDE OF THE N
WILLAMETTE VALLEY AS OF 03Z...WITH KHIO AT 55 DEG. COOLER AIR
REMAINED TRAPPED ON THE EAST SIDE OF THE N VALLEY WITH TEMPS IN THE
MID TO UPPER 40S. KTTD-KDLS GRADIENT WAS AT -5.5 MB JUST BEFORE 04Z
WITH GUSTS TO 25 MPH AT KTTD. KRTX DUAL-POL DOPPLER RADAR SHOWING
HEAVIER RETURNS ALONG THE COAST ASSOCIATED WITH THE LEADING EDGE OF
THE COLD FRONT. INFRA-RED SATELLITE LOOP WITH NAM 12 SFC PRES
OVERLAID SHOWED A NEAR 990 MB LOW PRES CENTER AT 47N 129W MOVING TO
THE NE. TRAILING END OF THE COLD FRONT LOOKED TO BE NEAR 125W AT
0330Z. FRONT MAY MOVE ASHORE A LITTLE QUICKER THAN THE NAM INDICATED.
KRTX VELOCITY DISPLAY INDICATED 60-65 KT S-SW WIND ABOUT 5000 FT MSL.
STRONGEST WIND GUSTS EARLY THIS EVENING HAVE BEEN AT GARIBALDI...
AROUND 55 MPH...WITH A COUPLE ISOLATED GUSTS 55 TO 60 MPH. THE PEAK
WIND PERIOD STILL LOOKS TO BE THROUGH ABOUT 07Z.
SOME RATHER IMPRESSIVE RAINFALL TOTALS FOR PORTIONS OF THE N OREGON
CASCADES AND IN THE OREGON COAST RANGE. NEARLY 3.5 INCHES OF RAIN HAD
FALLEN AT THE 5880 FT TIMBERLINE SENSOR...WITH RAINFALL RATES UP TO
0.5 INCHES PER HR THIS AFTERNOON. AROUND 1.5 TO 3 INCHES HAVE FALLEN
IN THE OREGON COAST RANGE. FORTUNATELY...THE HEAVIER RAIN RATES HAVE
PUSHED INTO WASHINGTON. THERE WILL BE ANOTHER 3-6 HR PERIOD TONIGHT
OF HEAVIER RAINFALL WITH THE COLD FRONT. ADDED A SLIGHT CHANCE OF
TSTMS FOR THE COASTAL WATERS 03Z-06Z AS THE HRRR MODEL WAS HINTING AT
THE POTENTIAL FOR POTENTIAL CONVECTIVE DEVELOPMENT ALONG THE COLD
FRONTAL BOUNDARY AS IT MOVED TOWARD THE COASTLINE. DID NOT INCLUDE
THE COASTAL ZONES AT THIS TIME. NAMM SOUNDING FOR KAST NOT ALL THAT
IMPRESSIVE WITH CONVECTIVE POSSIBILITIES...BUT SOMETHING THAT WILL
NEED TO BE CLOSELY MONITORED AS THE FRONT MOVES ASHORE.
ONCE THE COLD FRONT MOVES INLAND...AIR MASS TRANSITIONS TO A COOLER
MORE UNSTABLE AIR MASS. MODEL SOUNDINGS INDICATE THE POST FRONTAL
UNSTABLE LAYER IS LIMITED VERTICALLY BY SOME SUBSIDENCE ALOFT...SO
CONVECTION IS NOT EXPECTED TO BE TERRIBLY DEEP...PROBABLY UP TO
AROUND 15K FT. A SERIES OF SHORTWAVES ON SUN WILL PROVIDE SOME
DYNAMIC LIFT FOR POST FRONTAL SHOWERS...WITH OROGRAPHIC LIFT AIDING
THE WINDWARD SIDE OF MOUNTAINS. WEST FLOW ALOFT COMING IN OFF THE
PACIFIC WILL KEEP SNOW LEVELS ELEVATED A BIT...BUT BY LATE SUN ENOUGH
COOLING OCCURS TO DROP THE SNOW LEVEL DOWN BELOW MOST CASCADE PASSES.
CHANCES FOR SHOWERS WILL DROP OFF FROM S TO N SUN NIGHT INTO MON AS A
SURFACE HIGH BUILDS NORTHWARD. MODELS CONTINUE TO SHOW SOME DEGREE OF
THERMALLY-INDUCED SURFACE TROUGHING ALONG THE COAST MON NIGHT AND
TUE. COUPLED WITH STRENGTHENING HIGH PRES OVER THE NRN ROCKIES
CONFIDENCE IS HIGH THAT OFFSHORE LOW-LEVEL FLOW WILL RETURN MON NIGHT
AND PERSIST TUE. WEISHAAR
.LONG TERM...MODELS IN PRETTY GOOD AGREEMENT IN BEGINNING THE
EXTENDED PERIOD WITH AN UPPER RIDGE AT MID WEEK...WHICH SHOULD
RESULT IN DRY WEATHER BUT WITH PLENTY OF VALLEY FOG UNDER A
SUBSIDENCE INVERSION. MODELS AGREE IN WEAKENING THE RIDGE THU AND
FRI...ALTHOUGH HEIGHTS REMAIN HIGH. LOOKS LIKE WHATEVER SYSTEMS
BREAK THROUGH WILL BE ON THE WEAK SIDE...SO OVERALL WILL TEND TO
KEEP POPS ON THE LOW SIDE...PEAKING WITH SOME LIKELY POPS ACROSS THE
N ON FRI WHEN MODELS APPEAR TO BE IN BEST AGREEMENT WITH RAIN
POTENTIAL. WILL THEN TREND BACK TO DRIER CONDITIONS FOR NEXT WEEKEND
AS BOTH GFS AND ECMWF SUGGESTING A STRENGTHENING RIDGE AGAIN.
&&
.AVIATION...COASTAL SITES REMAINING MVFR WITH WINDS GUSTING TO 40
KTS AT KONP. EXPECT WINDS TO RAMP UP TO GUSTS NEAR 50 KT JUST
AHEAD OF FRONTAL PASSAGE. INTERIOR VALLEY SITES PRIMARILY
MVFR...WITH OCCASIONAL BREAKS TO VFR CIGS AS WINDS ARE RAMPING UP
OUT OF THE SOUTH. SO FAR KPDX AND KTTD STILL HAVE SOLID EASTERLY
WINDS WITH A TTD-DLS GRADIENT OF -4.6 KEEPING WINDS OUT OF THE
EAST. AS THE WARM FRONT PUSHES FURTHER NORTH OVER THE NEXT COUPLE
HOURS...EXPECT WINDS TO TURN SOUTHERLY AND RAMP UP LATER TONIGHT.
UNTIL THEN...WIND SHEAR OF 30-35 KTS FROM SFC TO FL020 IS BEING
OBSERVED VIA AMDAR SOUNDING DATA OUT OF PDX...WITH EASTERLY WINDS
AT THE SURFACE AND SOUTHERLY WINDS ALOFT. EXPECT MVFR CONDITIONS
TO CONTINUE AT INTERIOR VALLEY SITES UNTIL THE COLD FRONT MOVES
THROUGH AROUND 9-10Z. WINDS WILL EASE BEHIND THE FRONT...VEERING
WINDS MORE WESTERLY BY DAYBREAK SUNDAY. CIGS MAY RISE A LITTLE AT
THIS TIME...BUT STAY SOMEWHERE BETWEEN 015 AND 025 AGL. EXCEPTIONS
WILL LIKELY BE KONP AND KEUG WHERE IFR COULD PREVAIL ALL DAY.
KPDX AND APPROACHES...MVFR CONDITIONS TO CONTINUE THROUGH MOST OF
TONIGHT...WITH LLWS UNTIL WINDS VEER TO SOUTH AROUND 06Z. WINDS
AFTER 06Z WILL INCREASE TO 20 TO 25 KT WITH GUSTS NEAR 35 KT
LIKELY. WINDS EASE AFTER 09Z BEHIND COLD FRONT...FALLING BELOW 20
KT BY 10Z. CIGS LIFT SOME AROUND 12-14Z...BUT LIKELY WILL STAY
BELOW FL040 ALL DAY THUS LIMITING VISUAL APPROACHES. -MCCOY/JBONK
&&
.MARINE...WINDS AROUND 30 KT GUSTING TO 40 KT AT BUOY 29.
SOUTHERLY WINDS LIKELY WILL CONTINUE TO INCREASE...GUSTING TO 45 KT
AS FRONT APPROACHES THE COAST. SEAS NOT INCREASING AT RATE
EXPECTED...SO SEAS LIKELY TO PEAK A BIT LOWER AROUND 16 FT AFTER
MIDNIGHT...AND STAY UP IN THE LOW TO MIDDLE TEENS THROUGH SUNDAY.
WINDS VEER TO THE WEST-SOUTHWEST EARLY SUNDAY BEHIND THE
FRONT...AND REMAIN ABOVE 20 KT IN THE NORTHERN WATERS THROUGH MOST
OF THE DAY. WINDS LOOK TO WEAKEN OVER SOUTHERN WATERS SUNDAY
MORNING...DROPPING BELOW 20 KTS BY THE AFTERNOON.
HIGH PRESSURE BUILDS IN LATE SUNDAY BEHIND THE FRONT...STAYING IN
PLACE THROUGH EARLY THIS WEEK. THIS WILL ALLOW SEAS TO GRADUALLY
SUBSIDE UNTIL DROPPING BELOW 10 FT TUESDAY. -MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 3 AM PST SUNDAY FOR CENTRAL OREGON
COAST-NORTH OREGON COAST.
WA...HIGH WIND WARNING UNTIL 6 AM PST SUNDAY FOR SOUTH WASHINGTON
COAST.
PZ...GALE WARNING UNTIL 7 AM PST SUNDAY FOR COASTAL WATERS FROM CAPE
SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM.
GALE WARNING UNTIL 4 AM PST SUNDAY FOR COASTAL WATERS FROM
CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 PM
PST SUNDAY.
&&
$$
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...UPDATED
NWS BROWNSVILLE TX
1146 AM CST SUN JAN 18 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. /53/
&&
.AVIATION...
SURFACE HIGH PRESSURE CONTINUES TO SETTLE INTO THE REGION LATE THIS
MORNING. DESPITE THIS...WATER VAPOR IMAGERY SHOWS A CONTINUED W-SW
FLOW ALOFT...WHICH WILL ALLOW PLENTY OF MID- AND HIGH-LEVEL CLOUDS
TO CONTINUE STREAMING ACROSS AREA TERMINALS. EXPECT THE BEST
OPPORTUNITY FOR SEEING SCTD CLOUD COVER AND UNLIMITED CIGS TO REMAIN
OVER N PARTS OF THE FORECAST AREA...GENERALLY ALONG AND N OF A
ZAPATA TO ARMSTRONG LINE. CIGS OVER THE MAJOR RGV AIRPORTS SHOULD
REMAIN AT OR ABOVE 120...ALLOWING VFR FLIGHT CATEGORIES TO MOSTLY
CONTINUE THROUGH 19/1800 UTC.
HERE`S THE ONLY FLY IN THE OINTMENT -- WIND SPEEDS OF 5 KTS. OR LESS
TONIGHT MAY ALLOW SOME BR TO BE SEEN. SOME ADJUSTMENT TO ONSET
TIMING HAS BEEN MADE BASED ON THE LATEST HRRR AND PROBABILISTIC
GUIDANCE...AND I SUSPECT ANY POTENTIAL CIG REDUCTIONS DUE TO VSBYS
WILL LIKELY BE CONFINED TO KBRO AND KHRL. /53/
&&
.PREV DISCUSSION... /ISSUED 618 AM CST SUN JAN 18 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...IR SATL IMAGERY SHOWS PLENTY OF HIGH LEVEL CLDS MOVING
OVER THE REGION FROM WEST TO EAST. MEANWHILE AT THE LOW LEVELS
SURFACE OBS FROM AROUND THE REGION INDICATE THAT THE NORTHERLY
FLOW IS STARTING TO INCREASE OVER THE REGION ALLOWING DRIER AND
SLIGHTLY COOLER AIR TO FILTER IN FROM THE NORTH. NAM FORECAST
SOUNDINGS KEEP PRETTY DRY CONDITIONS AT THE MID AND LOWER LEVELS
OF THE ATMS. THE SURFACE WINDS GO LIGHT AND VARIABLE LATE IN THE
TAF PERIOD WHICH MAY ALLOW SOME PATCHY LIGHT FOG TO REFORM MON
MONDAY. EXPECT OVERALL VFR CONDITIONS TO PREVAIL FOR THE RGV
AIRPORTS OVER THE NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 419 AM CST SUN JAN 18 2015/
SHORT TERM /NOW THROUGH MONDAY/...A WEAK COLD FRONT IS PUSHING ITS
WAY THROUGH DEEP SOUTH TX EARLY THIS MORNING WITH LIGHT W-NW WINDS
BUILDING IN OVER THE REGION. KBRO RADAR IS SHOWING SOME LIGHT
ELEVATED REFLECTIVITY MOVING FROM WEST TO EAST OVER MUCH OF
NORTHEASTERN MEXICO. SO FAR SURFACE OBS INDICATE THAT THESE ECHOES
ARE NOT REACHING THE GROUND. IR SATL IMAGERY SHOWS PLENTY OF MID AND
HIGH LEVEL CLD COVER ADVECTING OVER TX FROM WEST TO EAST AND EXPECT
THIS TO REMAIN IN PLACE OVER THE REGION THROUGHOUT THE SHORT TERM
PERIOD AS THE ELEVATED MOISTURE FEED FROM THE WEST PERSISTS. THE
SURFACE HIGH MOVING IN PLACE IN THE WAKE OF THE WEAK COLD FRONT THIS
MORNING WILL BE MOVING OFF PRETTY QUICKLY TO THE EAST ALOWING FOR A
RETURN OF LIGHT EAST TO SOUTHERLY SURFACE FLOW ON MON.
THE MAV/MET AND ECMWF TEMP GUIDANCE THROUGHOUT THE SHORT TERM PERIOD
IS IN PRETTY DECENT AGREEMENT MAINTAINING FAIRLY STATUS QUO TEMPS
SINCE CAA WILL BE FAIRLY WEAK TODAY. SO WILL STICK CLOSE TO A
GENERAL BLEND OF THE SHORT TERM TEMP GUIDANCE THROUGH TOMORROW.
ALTHOUGH WE ARE DETECTING THE LIGHT ELEVATED PCPN ECHOES TO OUR WEST
AND SOUTH TODAY BELIEVE THAT THE DRIER AIR FILTERING IN FROM THE
NORTH WILL PREVENT ANY VIRGA FROM REACHING THE GROUND TODAY. SO NEAR
NIL POPS EXPECTED THROUGH TOMORROW.
SURFACE OBS OVER THE PAST HOUR HAVE STARTED REPORTING SOME AREAS OF
FOG OVER THE REGION. SO FAR THE FOG HAS BEEN FAIRLY LIGHT. SINCE THE
SURFACE WINDS OVER MOST OF THE AREA HAVE ALREADY SHIFTED AROUND TO
THE W-N BELIEVE THAT THE CURRENT FOG WILL LIKELY REMAIN PRETTY LIGHT
AND SHORT LIVED AS THE DRIER AIR ERODES AWAY THE SURFACE MOISTURE.
NO DENSE FOG EXPECTED.
LONG TERM /MONDAY NIGHT THROUGH SATURDAY NIGHT/...A BENIGN WEATHER
PATTERN IS EXPECTED MONDAY NIGHT THROUGH TUESDAY NIGHT AS DRY
NORTHWEST TO WEST WINDS ALOFT PREVAILS ACROSS THE REGION. OVERNIGHT
LOW TEMPERATURES MONDAY NIGHT WILL BE IN THE 50S. ABUNDANT SUNSHINE
AND A SLIGHTLY DRIER AIR WILL PROVIDE FOR A WARM DAY ACROSS DEEP
SOUTH TEXAS ON TUESDAY WITH HIGH TEMPERATURES REACHING THE UPPER
70S...TO AROUND 80 ACROSS THE WEST.
NEXT COLD FRONT ARRIVES WEDNESDAY MORNING. RAIN CHANCES BEGIN TO
INCREASE ON WEDNESDAY WITH THE BETTER RAIN CHANCES WEDNESDAY NIGHT
INTO THURSDAY NIGHT DUE TO THE DEVELOP OF A COASTAL TROUGH AND
APPROACHING 500MB TROUGH. THE AIR MASS IS NOT OVERLY COLD BUT
OVERRUNNING RAIN AND BREEZY NORTH WINDS WILL ALLOW TEMPERATURES TO
FALL OR REMAIN STEADY WEDNESDAY NIGHT THROUGH FRIDAY. TEMPERATURES
WEDNESDAY NIGHT AND THURSDAY WILL REMAIN IN THE 50S. LOW
TEMPERATURES THURSDAY NIGHT WILL FALL INTO THE 40S AS A SURGE OF
HIGH PRESSURE MOVES INTO THE AREA. RAIN CHANCES DECREASE ON FRIDAY
AS MID TO UPPER TROUGH SWINGS THROUGH DEEP SOUTH TEXAS. RAIN CHANCES
DECREASE WEST TO EAST ON FRIDAY HOWEVER...SOME TIMING ISSUES
CONTINUE DUE TO MODEL DIFFERENCES. HIGH TEMPERATURES WILL BE IN THE
LOW TO MID 50S FRIDAY. HIGH PRESSURE SETTLES ACROSS THE AREA FRIDAY
NIGHT WITH OVERNIGHT LOW TEMPERATURES FRIDAY NIGHT IN THE 40S. HIGH
PRESSURE CONTINUES OVERHEAD ON SATURDAY WITH HIGHS NEAR 60.
MARINE.../NOW THROUGH MONDAY/...THE PGF WILL STRENGTHEN SOME TODAY AS
SOME STRONGER N-NE SURFACE WINDS BUILD IN BEHIND THE COLD FRONT.
HOWEVER THIS SHOULD BE FAIRLY SHORT LIVED AND THE GRADIENT SHOULD
RELAX LATER TODAY AND TONIGHT WITH LIGHT SOUTHERLY WINDS RETURNING
TOMORROW. WILL MENTION SCEC CONDITIONS ACROSS THE GULF WATERS TODAY.
MONDAY NIGHT THROUGH THURSDAY NIGHT...FAVORABLE MARINE CONDITIONS
WILL PREVAIL ALONG THE LOWER TEXAS COAST MONDAY NIGHT THROUGH
TUESDAY NIGHT. STRONGER WINDS AND HIGHER SEAS WILL DEVELOP WEDNESDAY
AND THURSDAY DUE TO THE ARRIVAL OF A COLD FRONT WEDNESDAY MORNING.
SMALL CRAFT ADVISORIES WILL BE LIKELY BE NEEDED ON THURSDAY. RAIN
CHANCES WILL INCREASE WEDNESDAY INTO THURSDAY AS A LOW PRESSURE
TROUGH DEVELOPS OVER THE LOWER TEXAS GULF WATERS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM FORECASTER... BUTTS
LONG TERM FORECASTER... MILLER
PSU... BILLINGS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1014 AM EST SUN JAN 18 2015
.SYNOPSIS...
LOW PRESSURE MOVING UP THE COAST FROM THE CAROLINAS WILL MERGE
WITH A COLD FRONT CROSSING THE REGION TODAY...AND BY TONIGHT A
DEEPENING LOW PRESSURE SYSTEM WILL BE OVER NEW ENGLAND. HIGH
PRESSURE WILL COVER THE SOUTHEAST UNITED STATES MONDAY. A CLIPPER
WILL TRACK FROM THE NORTHERN PLAINS ON MONDAY NIGHT INTO THE MID
ATLANTIC REGION BY WEDNESDAY MORNING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM EST SUNDAY...
FOR THE MOST PART THINGS ARE UNFOLDING ON SCHEDULE. ONE LAST SURGE
OF SPOTTY LIGHT RAIN IS MOVING THROUGH OUR FAR EASTERN SECTIONS OF
THE PIEDMONT ASSOCIATED WITH DEVELOPING LOW PRESSURE OVER COASTAL
NORTH CAROLINA...WHILE LIGHT PRECIPITATION ASSOCIATED WITH A COLD
FRONT MOVING IN FROM THE WEST IS AFFECTING AREAS WEST OF THE BLUE
RIDGE. HAVE MADE MINOR ADJUSTMENTS TO THE GRIDS MAINLY TO REFLECT
CURRENT RADAR TRENDS OUT EAST SINCE WESTERN AREAS APPEARED TO BE
ON TARGET. MAX TEMPS STILL LOOK TO BE ON TARGET. TEMPS ACROSS THE
EAST WILL GET A CHANCE TO RECOVER AS PCPN PULLS OUT BEFORE THE
COLD FRONT MOVES THROUGH. TEMPS WEST WILL STRUGGLE A BIT UNDER CLOUDS
AND DEVELOPING COLD AIR ADVECTION.
WILL BE WATCHING DEVELOPMENT OF GUSTY WINDS VERY CLOSELY THROUGH
EARLY THIS AFTERNOON. BUFKIT MODEL SOUNDINGS SHOW GOOD DOWNWARD
MOMENTUM TRANSPORT AS LOW LEVEL JET DEVELOPS AND SLIDES NORTH
ALONG THE BLUE RIDGE LATER TODAY AND INTO TONIGHT. IF DEVELOPING
WINDS OFFER A LOT OF SUPPORT TO THIS SCENARIO WILL HAVE TO
CONSIDER EXPANDING THE WIND ADVISORY TO LOCATIONS FURTHER NORTH.
PREVIOUS AFD...
WATER VAPOR LOOP SHOWED A WELL DEFINED SHORT WAVE CROSSING THROUGH
INDIANA. THE ASSOCIATED SURFACE FRONT EXTENDED FROM MICHIGAN TO
ARKANSAS. THE SHOWERS WERE ALIGNED ALONG THE FRONT. LATEST RAP
GUIDANCE LINED UP WELL WITH BOTH AREAS OF PRECIPITATION AND HAD
REASONABLE TIMING AND PLACEMENT FOR TODAY. 00Z LOCAL WRF WAS GOOD
WITH THE LOCATION OF THE RAIN...ALTHOUGH A COUPLE OF HOURS SLOW.
WILL USE LATEST RADAR TRENDS FOR FINAL PLACEMENT OF RAIN THIS
MORNING.
UPPER TROF AND COLD FRONT WILL BE EAST OF THE FORECAST AREA BY
21Z/5PM. ONCE COLD FRONT GOES THROUGH THE MOUNTAINS THIS
MORNING...EXPECTING STEADY OR SLOWLY FALLING TEMPERATURES FOR THE
REST OF THE DAY.
MODELS FORECAST LOW LEVEL MOISTURE BEHIND THE FRONT IN SOUTHEAST
WEST VIRGINIA. WIND SPEEDS PLENTY STRONG ENOUGH FOR GOOD UPSLOPE
ALTHOUGH WIND DIRECTION IS NOT IDEAL. STILL ENOUGH LIFT EXPECTED TO
HAVE SNOW SHOWERS IN THE FAVORED AREAS LATE TONIGHT. WILL BE
REMOVING CHANCE OF SNOW SHOWERS IN THE SOUTHWEST COUNTIES FOR THIS
EVENING.
NAM/GFS SHOWED CONCENTRATION OF HIGHEST 850 MB WINDS ALONG THE BLUE
RIDGE MIGRATING FROM NORTHWEST NORTH CAROLINA AROUND 00Z/7PM TO
CENTRAL VIRGINIA LATE TONIGHT. NO CHANGES NEEDED TO THE WIND
ADVISORY AT THIS TIME.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM EST SUNDAY...
DEEPENING LOW OVER MAIN WILL KEEP SOME ENHANCED WINDS AROUND MONDAY
MORNING BUT BY MID MORNING ALL WINDS SHOULD BE UNDER 40 MPH IN
GUSTS...SO THE ADVISORY EXPIRATION OF 10 AM LOOKS REASONABLE. EXPECT
MOISTURE EROSION FAIRLY QUICK WITH FLOW TURNING MORE TO THE WEST AS
WE HEAD INTO THE AFTERNOON...SO ANY SNOW SHOWERS OVER WRN GREENBRIER
TO FLATTOP WV WILL BE GOING AWAY BY MID MORNING AS WELL. 8H TEMPS
WARM BY AFTERNOON WITH HIGHS RANGING FROM THE UPPER 30S TO LOWER 40S
SE WV MTNS...TO MID TO UPPER 40S NEW RIVER VALLEY AND NC MTNS...TO
50-55 EAST.
FLOW AT THE SFC WEAKENS MONDAY NIGHT INTO TUESDAY WHILE WAA
CONTINUES ALOFT. WILL SEE SKIES MAINLY CLEAR THOUGH SOME HIGH CLOUDS
WILL INCREASE AHEAD OF A CLIPPER TUESDAY. LOWS ARE GOING TO STAY AT
OR JUST ABOVE NORMAL MONDAY NIGHT IN THE MID 20S TO LOWER
30S...WARMING TO THE MID 40S-AROUND 50 MOUNTAINS TO LOWER TO MID 50S
EAST TUESDAY.
THE 00Z GFS/ECM SIMILAR IN TIMING WITH RESPECT TO THE CLIPPER TUE
NIGHT-WED...BUT LOCATION IS DIFFERENT. THE ECM ADVANCES THE LOW
ACROSS THE CENTRAL APPALACHIANS INTO NC TUE NIGHT THEN OVER THE VA
TIDEWATER WED AFTERNOON. THE GFS IS FURTHER NORTH FROM OH/PA TUE
NIGHT SOUTHEAST TO THE CHESAPEAKE BAY BY WED AFTERNOON. STILL MODELS
SHOWING A FAIRLY DECENT SHOT OF PRECIP ESPECIALLY IN THE NRN AND WRN
CWA GOING INTO WED MORNING. QUESTION IS PTYPE/THERMAL PROFILE. WITH
A BLEND WITH THE TWO MODELS EXPECT A RAIN CHANGING TO SNOW SHOWER
EVENT IN THE MOUNTAINS AND SOME BEFORE THE NW FLOW WORKS IN DRIER
AIR EAST OF THE MTNS BY WED NIGHT. AT THIS TIME...AMOUNTS QUITE LOW
SO NOT EXPECTING MUCH SNOW...THOUGH IF A FURTHER SOUTH PATH
OCCURS...THERE COULD BE SOME 1-3 INCH ACCUMULATIONS ACROSS THE
ALLEGHANY HIGHLANDS AND MTNS OF SE WV. STILL SUB ADVISORY LEVELS.
KEPT WEDNESDAY TEMP FORECAST THE SAME AS TEMPS FALL INTO THE 30S IN
THE WEST BY LATE AFTERNOON.
BY WED NIGHT THINK WILL SEE A FEW LINGERING SNOW SHOWERS IN THE
MOUNTAINS THOUGH UPSLOPE WEAKENS...BUT CORE OF 8H THERMAL TROUGH
STICKS AROUND WEST OF THE MTNS. LOWS WILL BE IN THE 20S...WITH LOWER
30S ACROSS THE PIEDMONT SOUTH OF LYH.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 256 PM EST SATURDAY...
WINDS BEGIN TO RETURN TO THE SOUTHWEST THURSDAY AS THE NEXT
DISTURBANCE TRACKS FROM THE GREAT LAKES TO THE OHIO VALLEY. GFS
PORTRAYS THIS DISTURBANCE AS A CLIPPER MOVING FROM THE NORTHERN
PLAINS THURSDAY TO THE OHIO VALLEY AND CENTRAL APPALACHIANS BY
FRIDAY AFTERNOON. THE ECM HAS A SIMILAR PRECIPITATION PATTERN OVER
THE OHIO VALLEY BUT IS LESS ON AMOUNTS WITH PARENT LOW TRACKING
ACROSS SOUTHEASTERN CANADA. GFS POPS ARE 40-60 WHILE THE ECM IS AT
ZERO FRIDAY AND FRIDAY NIGHT. THIS IS ALSO THE SAME TIME FRAME
BOTH MODELS...AT ONE TIME OR ANOTHER...WERE PHASING THE NORTHERN
AND SOUTHERN STREAMS. NOW...NO PHASING IS OCCURRING AND THEY HAVE
A DISTURBANCE/CLIPPER TRACKING ACROSS THE OHIO VALLEY. WE WILL
CONTINUE TO KEEP POPS IN LINE WITH CONFIDENCE LEVEL...LOW.
IF THIS DISTURBANCE DOES DEVELOP AND MOVE ACROSS ON FRIDAY...HIGH
PRESSURE WILL BUILD IN FOR THE WEEKEND. WE DID NOT STRAY TO FAR
FROM GUIDANCE OR CLIMATOLOGY FOR TEMPERATURES THURSDAY INTO
SATURDAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AS OF 645 AM EST SUNDAY...
WESTERN EDGE OF RAIN AND MVFR CEILINGS WAS ABOUT 10SM EAST OF KDAN
AT 630AM. EXPECT THE LOWER CLOUDS AND PRECIPITATION TO GRADUALLY
MOVE AWAY FROM KDAN AND KLYH SO CEILINGS MAY IMPROVE TO VFR SOONER
THAN 15Z/10AM.
LEADING EDGE OF PRECIPITATION ASSOCIATED WITH COLD FRONT
APPROACHING FROM THE WEST EXTENDED FROM NORTHEAST OHIO TO EASTERN
TENNESSEE. HRRR AND BUFKIT DATA WERE USED FOR THE TIMING OF THE
SHOWERS AND THE FRONTAL PASSAGE. LOWER CONFIDENCE AS TO WHETHER
CEILINGS WILL DROP TO MVFR WITH THE SHOWERS.
WINDS WILL SHIFT TO THE WEST-NORTHWEST BEHIND THE FRONT. DO NOT
EXPECT THESE SHOWERS TO REACH KLYH OR KDAN BEFORE THEY DISSIPATE.
WIND GUSTS WILL INCREASE AND WILL BE IN THE 15 TO 25 KNOT RANGE
FOR THE REST OF THE AFTERNOON.
LOW LEVEL MOISTURE WILL BANK UP AGAINST THE APPALACHIANS THIS
AFTERNOON THROUGH TONIGHT. WENT WITH LOWER CEILINGS THAN SUGGESTED
BY THE MODELS AT KLWB AND KBLF. ANY SNOW ACCUMULATION THROUGH
MONDAY MORNING WILL BE LIGHT. WINDS WILL CONTINUE TO GUST 20 TO 35
KNOTS OVERNIGHT...ESPECIALLY AT HIGHER ELEVATIONS.
EXTENDED DISCUSSION...
ZONAL FLOW RETURNS MONDAY...WITH THE REMAINING UPSLOPE CLOUDS
ACROSS THE MOUNTAINS SLOWLY DISSIPATING AND BY MID AFTERNOON
MONDAY ALL TAF LOCATIONS SHOULD BE VFR. A SERIES OF WEAK
DISTURBANCES BETWEEN TUESDAY AND THURSDAY WILL BRING THE CHANCE
FOR SUB VFR CONDITIONS MAINLY TO THE MOUNTAINS DUE TO SUBSEQUENT
FRONTAL PASSAGES AS WELL AS UPSLOPE CLOUDS/PRECIP.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST MONDAY FOR
VAZ015.
NC...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST MONDAY FOR
NCZ001-002-018.
WV...NONE.
&&
$$
SYNOPSIS...AMS/MBS
NEAR TERM...AMS
SHORT TERM...WP
LONG TERM...RCS
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
651 AM EST SUN JAN 18 2015
.SYNOPSIS...
LOW PRESSURE MOVING UP THE COAST FROM THE CAROLINAS WILL MERGE
WITH A COLD FRONT CROSSING THE REGION TODAY...AND BY TONIGHT A
DEEPENING LOW PRESSURE SYSTEM WILL BE OVER NEW ENGLAND. HIGH
PRESSURE WILL COVER THE SOUTHEAST UNITED STATES MONDAY. A CLIPPER
WILL TRACK FROM THE NORTHERN PLAINS ON MONDAY NIGHT INTO THE MID
ATLANTIC REGION BY WEDNESDAY MORNING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EST SUNDAY...
RADAR SHOWED RAPID DEVELOPMENT OF RAIN FROM COASTAL GEORGIA TO
NORTHERN NORTH CAROLINA. EXPECT COVERAGE TO CONTINUE TO EXPAND AND
SHIFT EAST THROUGH 12Z/7AM. WILL ADD CHANCE OF RAIN IN FOR THE NORTH
CAROLINA COUNTIES EARLY THIS MORNING...BUT THE BEST CHANCE WILL
REMAIN EAST OF US-29. TEMPERATURES WILL RISE INTO THE MID 30S WITH
THE CLOUD COVER SPREADING NORTH THIS MORNING. MOISTURE ADVECTION AND
PRECIPITATION IN THE EAST WILL ALSO BRING DEW POINTS UP INTO THE
LOWER 30S. THIS WILL ELIMINATE THE CHANCE FOR ANY FREEZING
PRECIPITATION.
WATER VAPOR LOOP SHOWED A WELL DEFINED SHORT WAVE CROSSING THROUGH
INDIANA. THE ASSOCIATED SURFACE FRONT EXTENDED FROM MICHIGAN TO
ARKANSAS. THE SHOWERS WERE ALIGNED ALONG THE FRONT. LATEST RAP
GUIDANCE LINED UP WELL WITH BOTH AREAS OF PRECIPITATION AND HAD
REASONABLE TIMING AND PLACEMENT FOR TODAY. 00Z LOCAL WRF WAS GOOD
WITH THE LOCATION OF THE RAIN...ALTHOUGH A COUPLE OF HOURS SLOW.
WILL USE LATEST RADAR TRENDS FOR FINAL PLACEMENT OF RAIN THIS
MORNING.
UPPER TROF AND COLD FRONT WILL BE EAST OF THE FORECAST AREA BY
21Z/5PM. ONCE COLD FRONT GOES THROUGH THE MOUNTAINS THIS
MORNING...EXPECTING STEADY OR SLOWLY FALLING TEMPERATURES FOR THE
REST OF THE DAY.
MODELS FORECAST LOW LEVEL MOISTURE BEHIND THE FRONT IN SOUTHEAST
WEST VIRGINIA. WIND SPEEDS PLENTY STRONG ENOUGH FOR GOOD UPSLOPE
ALTHOUGH WIND DIRECTION IS NOT IDEAL. STILL ENOUGH LIFT EXPECTED TO
HAVE SNOW SHOWERS IN THE FAVORED AREAS LATE TONIGHT. WILL BE
REMOVING CHANCE OF SNOW SHOWERS IN THE SOUTHWEST COUNTIES FOR THIS
EVENING.
NAM/GFS SHOWED CONCENTRATION OF HIGHEST 850 MB WINDS ALONG THE BLUE
RIDGE MIGRATING FROM NORTHWEST NORTH CAROLINA AROUND 00Z/7PM TO
CENTRAL VIRGINIA LATE TONIGHT. NO CHANGES NEEDED TO THE WIND
ADVISORY AT THIS TIME.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM EST SUNDAY...
DEEPENING LOW OVER MAIN WILL KEEP SOME ENHANCED WINDS AROUND MONDAY
MORNING BUT BY MID MORNING ALL WINDS SHOULD BE UNDER 40 MPH IN
GUSTS...SO THE ADVISORY EXPIRATION OF 10 AM LOOKS REASONABLE. EXPECT
MOISTURE EROSION FAIRLY QUICK WITH FLOW TURNING MORE TO THE WEST AS
WE HEAD INTO THE AFTERNOON...SO ANY SNOW SHOWERS OVER WRN GREENBRIER
TO FLATTOP WV WILL BE GOING AWAY BY MID MORNING AS WELL. 8H TEMPS
WARM BY AFTERNOON WITH HIGHS RANGING FROM THE UPPER 30S TO LOWER 40S
SE WV MTNS...TO MID TO UPPER 40S NEW RIVER VALLEY AND NC MTNS...TO
50-55 EAST.
FLOW AT THE SFC WEAKENS MONDAY NIGHT INTO TUESDAY WHILE WAA
CONTINUES ALOFT. WILL SEE SKIES MAINLY CLEAR THOUGH SOME HIGH CLOUDS
WILL INCREASE AHEAD OF A CLIPPER TUESDAY. LOWS ARE GOING TO STAY AT
OR JUST ABOVE NORMAL MONDAY NIGHT IN THE MID 20S TO LOWER
30S...WARMING TO THE MID 40S-AROUND 50 MOUNTAINS TO LOWER TO MID 50S
EAST TUESDAY.
THE 00Z GFS/ECM SIMILAR IN TIMING WITH RESPECT TO THE CLIPPER TUE
NIGHT-WED...BUT LOCATION IS DIFFERENT. THE ECM ADVANCES THE LOW
ACROSS THE CENTRAL APPALACHIANS INTO NC TUE NIGHT THEN OVER THE VA
TIDEWATER WED AFTERNOON. THE GFS IS FURTHER NORTH FROM OH/PA TUE
NIGHT SOUTHEAST TO THE CHESAPEAKE BAY BY WED AFTERNOON. STILL MODELS
SHOWING A FAIRLY DECENT SHOT OF PRECIP ESPECIALLY IN THE NRN AND WRN
CWA GOING INTO WED MORNING. QUESTION IS PTYPE/THERMAL PROFILE. WITH
A BLEND WITH THE TWO MODELS EXPECT A RAIN CHANGING TO SNOW SHOWER
EVENT IN THE MOUNTAINS AND SOME BEFORE THE NW FLOW WORKS IN DRIER
AIR EAST OF THE MTNS BY WED NIGHT. AT THIS TIME...AMOUNTS QUITE LOW
SO NOT EXPECTING MUCH SNOW...THOUGH IF A FURTHER SOUTH PATH
OCCURS...THERE COULD BE SOME 1-3 INCH ACCUMULATIONS ACROSS THE
ALLEGHANY HIGHLANDS AND MTNS OF SE WV. STILL SUB ADVISORY LEVELS.
KEPT WEDNESDAY TEMP FORECAST THE SAME AS TEMPS FALL INTO THE 30S IN
THE WEST BY LATE AFTERNOON.
BY WED NIGHT THINK WILL SEE A FEW LINGERING SNOW SHOWERS IN THE
MOUNTAINS THOUGH UPSLOPE WEAKENS...BUT CORE OF 8H THERMAL TROUGH
STICKS AROUND WEST OF THE MTNS. LOWS WILL BE IN THE 20S...WITH LOWER
30S ACROSS THE PIEDMONT SOUTH OF LYH.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 256 PM EST SATURDAY...
WINDS BEGIN TO RETURN TO THE SOUTHWEST THURSDAY AS THE NEXT
DISTURBANCE TRACKS FROM THE GREAT LAKES TO THE OHIO VALLEY. GFS
PORTRAYS THIS DISTURBANCE AS A CLIPPER MOVING FROM THE NORTHERN
PLAINS THURSDAY TO THE OHIO VALLEY AND CENTRAL APPALACHIANS BY
FRIDAY AFTERNOON. THE ECM HAS A SIMILAR PRECIPITATION PATTERN OVER
THE OHIO VALLEY BUT IS LESS ON AMOUNTS WITH PARENT LOW TRACKING
ACROSS SOUTHEASTERN CANADA. GFS POPS ARE 40-60 WHILE THE ECM IS AT
ZERO FRIDAY AND FRIDAY NIGHT. THIS IS ALSO THE SAME TIME FRAME
BOTH MODELS...AT ONE TIME OR ANOTHER...WERE PHASING THE NORTHERN
AND SOUTHERN STREAMS. NOW...NO PHASING IS OCCURRING AND THEY HAVE
A DISTURBANCE/CLIPPER TRACKING ACROSS THE OHIO VALLEY. WE WILL
CONTINUE TO KEEP POPS IN LINE WITH CONFIDENCE LEVEL...LOW.
IF THIS DISTURBANCE DOES DEVELOP AND MOVE ACROSS ON FRIDAY...HIGH
PRESSURE WILL BUILD IN FOR THE WEEKEND. WE DID NOT STRAY TO FAR
FROM GUIDANCE OR CLIMATOLOGY FOR TEMPERATURES THURSDAY INTO
SATURDAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 645 AM EST SUNDAY...
WESTERN EDGE OF RAIN AND MVFR CEILINGS WAS ABOUT 10SM EAST OF KDAN
AT 630AM. EXPECT THE LOWER CLOUDS AND PRECIPITATION TO GRADUALLY
MOVE AWAY FROM KDAN AND KLYH SO CEILINGS MAY IMPROVE TO VFR SOONER
THAN 15Z/10AM.
LEADING EDGE OF PRECIPITATION ASSOCIATED WITH COLD FRONT
APPROACHING FROM THE WEST EXTENDED FROM NORTHEAST OHIO TO EASTERN
TENNESSEE. HRRR AND BUFKIT DATA WERE USED FOR THE TIMING OF THE
SHOWERS AND THE FRONTAL PASSAGE. LOWER CONFIDENCE AS TO WHETHER
CEILINGS WILL DROP TO MVFR WITH THE SHOWERS.
WINDS WILL SHIFT TO THE WEST-NORTHWEST BEHIND THE FRONT. DO NOT
EXPECT THESE SHOWERS TO REACH KLYH OR KDAN BEFORE THEY DISSIPATE.
WIND GUSTS WILL INCREASE AND WILL BE IN THE 15 TO 25 KNOT RANGE
FOR THE REST OF THE AFTERNOON.
LOW LEVEL MOISTURE WILL BANK UP AGAINST THE APPALACHIANS THIS
AFTERNOON THROUGH TONIGHT. WENT WITH LOWER CEILINGS THAN SUGGESTED
BY THE MODELS AT KLWB AND KBLF. ANY SNOW ACCUMULATION THROUGH
MONDAY MORNING WILL BE LIGHT. WINDS WILL CONTINUE TO GUST 20 TO 35
KNOTS OVERNIGHT...ESPECIALLY AT HIGHER ELEVATIONS.
EXTENDED DISCUSSION...
ZONAL FLOW RETURNS MONDAY...WITH THE REMAINING UPSLOPE CLOUDS
ACROSS THE MOUNTAINS SLOWLY DISSIPATING AND BY MID AFTERNOON
MONDAY ALL TAF LOCATIONS SHOULD BE VFR. A SERIES OF WEAK
DISTURBANCES BETWEEN TUESDAY AND THURSDAY WILL BRING THE CHANCE
FOR SUB VFR CONDITIONS MAINLY TO THE MOUNTAINS DUE TO SUBSEQUENT
FRONTAL PASSAGES AS WELL AS UPSLOPE CLOUDS/PRECIP.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST MONDAY FOR
VAZ015.
NC...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST MONDAY FOR
NCZ001-002-018.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...WP
LONG TERM...RCS
AVIATION...AMS/JH
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1147 PM CST SAT JAN 17 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 305 PM CST SAT JAN 17 2015
THE MAIN FOCUS THROUGH SUNDAY IS ON THE PRECIPITATION CHANCES IN
NORTH CENTRAL WISCONSIN TONIGHT FOLLOWED BY TEMPERATURES TOMORROW.
CURRENTLY...A MID LEVEL POSITIVELY TILTED TROUGH IS DIGGING TO THE
SOUTHEAST ACROSS MINNESOTA/NORTHWEST IOWA WITH A SURFACE LOW
LOCATED IN SOUTHWEST ONTARIO. A WARM FRONT ASSOCIATED WITH THIS
LOW EXTENDS SOUTH TOWARD LAKE MICHIGAN WITH A COLD FRONT TRAILING
SOUTH OF IT THROUGH NORTHEAST TO SOUTHWEST MINNESOTA. THE LATEST
OBSERVATIONS AND RADAR IMAGERY SHOWS A CLUSTER OF SNOW SHOWERS
OCCURRING IN NORTHEAST MINNESOTA CLOSER TO THE CORE OF THE MID
LEVEL/SURFACE TROUGH WHERE LIFT/MOISTURE IS DEEPER. THE QUESTION
IS WITH HOW FAR SOUTH THESE SNOW SHOWERS WILL MAKE IT TONIGHT. THE
PAST FEW RUNS OF THE RAP HAVE SHOWN THAT THE MOISTURE/LIFT DOES
NOT APPEAR TO BE DEEP ENOUGH TO PRODUCE MUCH SOUTH OF CLARK AND
TAYLOR COUNTIES IN NORTH CENTRAL WISCONSIN. AM NOT EXPECTING
DRIZZLE TO BE AN ISSUE BECAUSE WHERE THERE IS LIFT...THE MOISTURE
GETS DEEP ENOUGH TO PRODUCE ICE...SO HAVE BACKED OFF ON THAT
FORECAST.
OTHERWISE...GUSTY WEST TO NORTHWEST WINDS WILL HOLD ON THROUGH
MUCH OF THE NIGHT THOUGH ANY GUSTS SHOULD STAY BELOW ADVISORY
LEVELS. SKIES ARE EXPECTED TO CLEAR OUT FROM WEST TO EAST
OVERNIGHT WITH THE BACK EDGE OF THE CLOUD DECK ALREADY INTO
WESTERN MINNESOTA. SOME CLOUDS MAY LINGER LONGER IN WESTERN TO
NORTH CENTRAL WISCONSIN WHERE THE CORE OF THE TROUGH/LOW WILL BE
CLOSER.
WHILE WE LIKELY WILL NOT HIT 40 AGAIN TOMORROW...TEMPERATURES
WILL NOT DROP MUCH BEHIND THIS FRONT WITH THE MAIN POOL OF COLDER
850MB TRACKING TO THE EAST THROUGH THE GREAT LAKES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 305 PM CST SAT JAN 17 2015
THE NEXT FEATURE TO BRING ANY PRECIPITATION CHANCES WITH IT IS
ANOTHER POSITIVELY TILTED MID LEVEL TROUGH THAT DROPS DOWN FROM
THE NORTHWEST ON MONDAY/TUESDAY. THE FIRST ROUND FOR SOME LIGHT
SNOW APPEARS TO COME IN ON MONDAY ACROSS NORTH CENTRAL
WISCONSIN...THOUGH TRENDS FROM ALL OF THE GUIDANCE EXCEPT THE
17.12Z GFS SEEM TO BE TAKING THIS BELT OF LIFT FROM WARM AIR
ADVECTION FURTHER TO THE NORTH. THE 17.12Z ECMWF HAS A UNIQUE
SOLUTION WITH BRINGING SOME PRECIPITATION ACROSS IOWA WITH AN
850MB TROUGH. THE MAIN CHANCES FOR ANY LIGHT SNOW APPEAR TO COME
IN ON TUESDAY AS THE MAIN TROUGH SWINGS THROUGH. THERMAL PROFILES
LOOK COLD ENOUGH TO SUPPORT THE PRECIPITATION TYPE BEING ALL SNOW
BUT FORCING LOOKS WEAK SO AM NOT EXPECTING MUCH IF ANY
ACCUMULATIONS. BEYOND THAT IT LOOKS LIKE WE WILL STAY IN NORTHWEST
FLOW ALOFT THOUGH THE AIR MASS IS RELATIVELY ON THE MILD SIDE. A
COUPLE SHORT WAVE TROUGHS ARE POTENTIALLY OUT THERE AS WELL THOUGH
TIMING/TRACK IS FAIRLY UNCERTAIN BETWEEN THE MODELS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1147 PM CST SAT JAN 17 2015
CLEARING LINE EXTENDS FROM KLXL TO KMSP TO KRST TO KPDC AS OF
18.0530Z AND WILL CONTINUE TO PUSH EASTWARD OVERNIGHT RESULTING
IN VFR CONDITIONS AT BOTH TAF AIRFIELDS. FORECAST GUIDANCE
SUGGESTS MVFR CLOUD DECK CURRENTLY ACROSS NORTH-CENTRAL/NORTHEAST
MN SHOULD EVENTUALLY TRANSLATE TO THE SOUTHEAST...POSSIBLY
IMPACTING KLSE/KRST BY SUNDAY AFTERNOON. GIVEN RECENT MODEL
PERFORMANCE...CONFIDENCE NOT HIGH ENOUGH AT THIS TIME TO INTRODUCE
CEILINGS AT OR BELOW 3000 FT AGL...BUT SOMETHING TO WATCH AS NEW
GUIDANCE BECOMES AVAILABLE. NORTHWEST WIND WILL PERSIST THROUGH
THE PERIOD...BECOMING LIGHT BY SUNDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
905 AM EST TUE JAN 20 2015
.UPDATE (REST OF TODAY THROUGH WEDNESDAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS MUCH OF THE CONUS TO THE
EAST OF THE CONTINENTAL DIVIDE WITHIN A VERY BROAD LONGWAVE TROUGH.
EMBEDDED WITHIN THIS BROAD FLOW ARE SEVERAL WEAK SHORTWAVE
IMPULSES...HOWEVER AT THIS TIME NONE OF THESE ARE PRODUCING MUCH IN
THE WAY OF HAZARDOUS WEATHER...AND THE PATTERN ACROSS THE CONUS IS
UNUSUALLY QUIET FOR MID/LATE JANUARY. ONE OF THESE WEAK SHORTWAVE
IMPULSES IS CURRENTLY CROSSING THE EASTERN GULF OF MEXICO AND WILL
PASS OVER THE FLORIDA PENINSULA THIS AFTERNOON AND THEN OFF INTO THE
ATLANTIC THIS EVENING.
MORNING SATELLITE IMAGERY SHOWS A LARGE SWATH OF MAINLY MID/HIGH
LEVEL CLOUDS ASSOCIATED WITH THIS SHORTWAVE AND ASSOCIATED JET
STRUCTURE OVERHEAD. EXPECT SKIES TO REMAIN MOSTLY CLOUDY TO CLOUDY
FOR THE REMAINDER OF THE MORNING HOURS...WITH THE CHANCES FOR A FEW
SUNNY BREAKS INCREASING THE DEEPER INTO THE AFTERNOON WE GO. THE
BEST CHANCE AT ANY SIGNIFICANT SUN LATER TODAY WILL BE TO THE NORTH
OF THE TAMPA BAY AREA ACROSS THE NATURE COAST ZONES.
AREAS OF MAINLY LIGHT RAINFALL CAN BE SEEN ON REGIONAL RADARS OVER
THE COASTAL WATERS TO THE SOUTH OF TAMPA BAY. THIS RAINFALL IS THE
RESULT OF A COMBINATION BETWEEN LARGE SCALE QG FORCING ASSOCIATED
WITH THE SHORTWAVE...BROAD LOW LEVEL ISENTROPIC UPGLIDE IN THE LOWER
LEVELS ALONG THE 295-305K SURFACES...AND BROAD UPPER LEVEL
DIVERGENCE WITHIN THE LER OF A 90-100KT UPPER JET STREAK DROPPING
DOWN THE BACKSIDE OF THE SHORTWAVE.
THE RADAR IMAGE SEEMS TO SHOW LIGHT RAINFALL ALREADY SPREADING
ACROSS THE SOUTHERN HALF OF THE FLORIDA PENINSULA...HOWEVER THIS IS
SIMPLY DUE TO THE HIGHER ELEVATION SCANNING OF THE RADARS OVER THESE
AREAS. THE 20/12Z KTBW SOUNDING PROFILE SHOWS A VERY DRY ATMOSPHERIC
COLUMN IN PLACE BELOW 600-500MB...SO ANY PRECIP FALLING OUT OF THE
CLOUD DECK OVER LAND IS CURRENTLY VIRGA. OVER TIME...TIME-HEIGHT
ANALYSIS DOES SHOW THE COLUMN MOISTENING SOMEWHAT...AND DO EXPECT
AREAS SOUTH OF THE I-4 CORRIDOR TO SEE SOME SHOWER ACTIVITY DEVELOP
INTO THE LATER MORNING AND AFTERNOON HOURS. HOWEVER...THE OVERALL
FORCING FOR LIFT...INCLUDING THE UPGLIDE IS SHOWN TO WEAKEN WITH
TIME...AND THEREFORE DO NOT ANTICIPATE MUCH MORE THAN SOME PERIODS
OF LIGHT RAIN (LOW ACCUMULATION) SOUTH OF THE TAMPA BAY REGION...A
FEW SPRINKLES THROUGH TAMPA BAY (LITTLE TO NO ACCUMULATION)...AND
ESSENTIALLY NO RAIN ACROSS THE NATURE COAST TODAY.
TEMPERATURES ARE LOOKING TO REMAIN COOL TODAY...ESPECIALLY FROM I-4
SOUTHWARD WHERE A LONGER DURATION OF CLOUDS...AND SOME ADDED
WET-BULBING/EVAPORATIVE COOLING SLOWS THE DIURNAL TEMP CLIMB. WILL
LIKELY BE LOWERING HIGH TEMPS FOR THE CENTRAL/SOUTHERN ZONES BY A
COUPLE OF DEGREES WITH THE MORNING FORECAST UPDATE.
WHAT LITTLE FORCING FOR LIFT ASSOCIATED WITH SHORTWAVE QUICKLY
PASSES EAST OF THE REGION THIS EVENING. A SECONDARY SHORTWAVE WILL
QUICKLY BE ON ITS HEELS APPROACHING FROM THE SLOWER MS
VALLEY...HOWEVER THIS ENERGY AND ITS SYNOPTIC SUPPORT FOR LIFT LOOK
TO PASS MAINLY NORTH OF OUR REGION OVERNIGHT. THEREFORE...SOME SCT
LIGHT SHOWERS EARLY EVENING SOUTH WILL END BEFORE MIDNIGHT...WITH A
GENERALLY DRY OVERNIGHT FOR ALL THEREAFTER. TEMPERATURES WILL BE
SEASONABLE WITH MID/UPPER 40S NORTH OF THE I-4 CORRIDOR AND 50S
ELSEWHERE.
A QUIET SENSIBLE WEATHER DAY ON TAP FOR WEDNESDAY AS THE UPPER
LEVELS RETURN TO ZONAL FLOW AND WEAK HIGH PRESSURE AT THE SURFACE
RIDGES IN OVER THE REGION FROM THE NORTHWEST. EXPECT MUCH MORE IN
THE WAY OF SUNSHINE FOR WEDNESDAY WITH HIGH TEMPERATURES GENERALLY
IN THE LOWER 70S NORTH AND MIDDLE 70S SOUTH. HAVE A GREAT TUESDAY
EVERYBODY!
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS THE REGION UNDER WIDESPREAD MID/HIGH
LEVEL CLOUDS. THESE CONDITIONS WITH DEVELOPING MAINLY LIGHT SHOWERS
OR SPRINKLES EXPECTED THROUGH THE REMAINDER OF THE DAYLIGHT HOURS.
BEST CHANCES FOR SHOWERS AND A BRIEF PERIOD OF OF MVFR CIGS WILL
EXIST TO THE SOUTH OF THE TAMPA BAY REGION. SHOWERS END THIS EVENING
WITH VFR CONDITIONS LIKELY THROUGH MUCH OF THE OVERNIGHT. SOME
PATCHY GROUND FOG IS LIKELY LATE AT NIGHT...WITH KLAL AND KPGD
SEEING THE BEST SHOT AT A PERIOD OF VIS RESTRICTIONS IN THE HOURS
APPROACHING DAWN. ANY EARLY MORNING FOG BURNS OFF QUICKLY ON
WEDNESDAY WITH PREVAILING VFR CONDITIONS EXPECTED THE REMAINDER OF
THE DAY.
&&
.MARINE...
PATCHY LIGHT RAIN OR SPRINKLES WILL AFFECT THE WATERS MAINLY SOUTH
OF TAMPA BAY AS A WEAK DISTURBANCE OVER THE GULF WILL QUICKLY PASS
BY THE STATE TODAY. GENERALLY BENIGN WEATHER FOR THE NEXT COUPLE OF
DAYS...WITH WINDS 15 KNOTS OR LESS AND SEAS 2 FEET OR LESS EXPECTED
THROUGH THURSDAY. AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE GULF
AT THE END OF THE WEEK...BRINGING INCREASED RAIN CHANCES FRIDAY
THROUGH SATURDAY AS WELL AS INCREASING WINDS AND SEAS. NO HAZARDS
EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 69 58 73 59 / 10 10 10 0
FMY 72 60 77 61 / 40 20 10 0
GIF 70 56 75 58 / 10 10 10 0
SRQ 69 57 74 58 / 20 10 0 0
BKV 70 50 72 52 / 0 10 10 0
SPG 68 60 72 62 / 10 10 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...DOUGHERTY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1002 AM CST TUE JAN 20 2015
.SHORT TERM...
339 AM CST
THROUGH TODAY...
MAIN FORECAST CHALLENGES/CONCERNS TODAY ARE WITH A BRIEF WINDOW OF
FREEZING RAIN OR FREEZING DRIZZLE THIS MORNING ACROSS NORTHERN
ILLINOIS...AND THEN INCREASING CLOUD COVER AND CHANCES FOR PRECIP
VERY LATE THIS AFTERNOON.
BEEN MONITORING AN AREA OF PRECIP WHICH HAS MOVED SOUTHEAST
THROUGH IOWA AND SOUTHWEST WISCONSIN THIS MORNING...APPROACHING
THE RFD AREA AT THIS TIME. MAIN AREA OF PRECIP ACROSS THE REGION
HAS REMAINED WELL NORTH OF THE CWA ACROSS WISCONSIN AS SURFACE LOW
HAS DROPPED SOUTHEAST INTO NORTHWEST ILLINOIS THIS MORNING...BUT
STRONG VORT MAX HAS ENABLED FOR THE CONTINUED PRECIP DEVELOPMENT
FURTHER TO THE SOUTHWEST. THIS WILL LIKELY CONTINUE OVER THE NEXT
SEVERAL HOURS...MOVING INTO NORTH CENTRAL ILLINOIS OVER THE NEXT
1-2 HOURS AND THEN INTO NORTHEAST ILLINOIS AROUND THE 13Z TIME
FRAME. FORECAST SOUNDINGS INDICATING A MARGINAL SETUP FOR SNOW
DEVELOPMENT WITH RAIN THE LIKELY PRECIP TYPE. UPSTREAM OBS HAVE
SUPPORTED THIS WITH BOTH RAIN AND SNOW BEING REPORTED ACROSS IOWA
AND WISCONSIN. ONCE AGAIN...DONT ANTICIPATE THIS TO CHANGE ACROSS
THE CWA AND WITH AIR TEMPS AROUND FREEZING...AM A LITTLE CONCERNED
FOR A BRIEF WINDOW OF FREEZING RAIN OR FREEZING DRIZZLE AS THIS
PUSHES THROUGH. THIS WILL LIKELY BE LIGHT AND VERY BRIEF...UNDER
ONE HOUR...BUT STILL COULD CAUSE ISSUES THIS MORNING. THIS WILL
ESPECIALLY BE THE CASE ACROSS NORTHWEST AND NORTH CENTRAL ILLINOIS
WHERE TEMPS HAVE BEEN COOLER. ANY FREEZING COMPONENT WILL LIKELY
BECOME LESS OF A PROBLEM AS IT APPROACHES NORTHEAST ILLINOIS WITH
TEMPS SLIGHTLY WARMER. HAVE ISSUED AN SPS THIS MORNING AND WILL
CONTINUE TO MONITOR THE SOUTHEASTWARD MOVEMENT AND TEMP TRENDS FOR
AREAS ACROSS NORTHEAST ILLINOIS.
SKIES WILL LIKELY BE PARTLY CLOUDY TO PARTLY SUNNY TO START OFF
THIS MORNING AS CLOUD COVER OVER EAST CENTRAL ILLINOIS AND
NORTHWEST INDIANA DEPART...AND THEN AS LOW STRATUS DROPS SOUTH OUT
OF WISCONSIN. THIS SOUTHWARD MOVING STRATUS WILL BRING A RETURN TO
MOSTLY CLOUDY SKIES BY THE AFTERNOON FOR ALL AREAS...WITH ABOVE
NORMAL TEMPS STILL APPEARING LIKELY. DID LOWER TEMPS FOR TODAY
MAINLY OVER NORTHERN ILLINOIS WHERE STRATUS WILL APPROACH
QUICKER...BUT LEFT TEMPS OVER THE SOUTHERN HALF ALONE WHERE HIGHS
COULD REACH AROUND 40. HAVE POPS INCREASING VERY LATE IN THE
AFTERNOON TODAY MAINLY FOR THE NORTHERN HALF OF THE CWA BUT THEY
MAY BE TOO QUICK AS THE ARRIVAL OF THE NEXT SYSTEM AND PRECIP NOT
LIKELY UNTIL LATER THIS EVENING.
RODRIGUEZ
&&
.LONG TERM...
339 AM CST
TONIGHT THROUGH MONDAY...
A NICELY DEFINED MID-LEVEL CIRCULATION ON WATER VAPOR IMAGERY THIS
MORNING OVER NORTH DAKOTA WILL RIDE AN UPPER LEVEL PV INTRUSION
INTO THE FORECAST AREA LATE TONIGHT. IN ADVANCE OF THIS LOW
AMPLITUDE WAVE...SUBTLE ISENTROPIC ASCENT SHOULD GRADUALLY
INCREASE ALONG THE 900-700MB THERMAL BOUNDARY ATOP THE AREA. WITH
LOW-LEVEL SATURATION ALREADY IN PLACE BY THAT TIME...LIGHT
PRECIPITATION SHOULD EXPAND IN COVERAGE THIS EVENING...MAINLY
NORTH OF I-80. GIVEN THE FORCING IS LIGHT AT FIRST AND LIMITED ICE
CRYSTAL INITIATION PER FORECAST SOUNDINGS...A PERIOD OF LIGHT
LIQUID COULD OCCUR AT FIRST. SURFACE TEMPERATURES LOOK TO BE AT
OR POSSIBLY A BIT ABOVE FREEZING...SO NOT TOO CONCERNED ABOUT
THAT IF IT OCCURS EARLY THIS EVENING. FORCING INCREASES LATE IN
THE EVENING AND ESPECIALLY OVERNIGHT SO THAT CONFIDENCE INCREASES
PRECIPITATION TYPE WOULD CHANGE TO SNOW.
IT TAKES A WHILE FOR THIS SYSTEM TO MOVE THROUGH THE AREA WITH THE
VORT MAX STILL FORECAST OVER NORTHWEST INDIANA AT MIDDAY WEDNESDAY.
THIS INDICATES A LIGHT SNOW EVENT OF LONGER DURATION...AGAIN
ESPECIALLY FOR AREAS NORTH OF I-80. WHILE THERE WILL LIKELY BE
BREAKS IN THE SNOW DUE TO THE OVERALL MARGINAL
FORCING...ACCUMULATIONS OF AROUND ONE TO ONE AND A HALF INCHES
REMAIN FORECAST TO MATERIALIZE FROM THIS EVENING THROUGH MIDDAY
WEDNESDAY WITH SHARPLY LESSER AMOUNTS SOUTH OF I-80. RATES SHOULD
MAINLY BE LIGHT WITH LIMITED MESOSCALE FORCING...THOUGH AS THE
SNOW GROWTH ZONE LOWERS BY DAYBREAK WEDNESDAY SOME FORCING COULD
BETTER EXIST IN THE SNOW GROWTH AREA TO HELP INCREASE EFFICIENCY.
WILL NOT ISSUE ANY SPS AT THIS TIME WITH IT STILL BEING 24 HOURS
OUT AND TO AVOID CONFUSION WITH CURRENT SPS OUT FOR THIS MORNINGS
LIGHT FREEZING PRECIPITATION. PLUS IT WILL GIVE THE DAY CHANCE A
BETTER OPPORTUNITY TO REFINE DETAILS.
SOME LIGHT SNOW OR FLURRIES WILL REMAIN POSSIBLE WEDNESDAY AFTERNOON
AND EVENING ACROSS THE ENTIRE AREA WITH THE WAVE SHEARING AS IT
MOVES THROUGH. TEMPERATURES ARE NOT FORECAST TO RISE MUCH
WEDNESDAY GIVEN AMPLE CLOUDINESS.
COLDER AND MORE SEASONAL AIR DOES FILTER IN BEHIND THIS SYSTEM FOR
WEDNESDAY NIGHT INTO THURSDAY. LIMITED HEIGHT RISES AND SUPPRESSION
POINT TOWARD LOW CLOUDS HANGING AROUND...POSSIBLY EVEN THROUGH
THURSDAY NIGHT. SO HAVE LOW TEMPERATURES WEDNESDAY NIGHT STILL
ONLY FORECAST IN THE MID 20S.
AS THE PATTERN BEGINS TO AMPLIFY OVER THE NORTH AMERICAN WEST COAST
INTO CANADA...A STRONG LOW WILL MOVE NORTH OF THE GREAT LAKES AND
SWING A COLD FRONT INTO OUR REGION FRIDAY NIGHT. AHEAD OF THIS
SYSTEM...FRIDAY LOOKS LIKE A BREEZY DAY WITHIN A MODEST WARM SECTOR.
WITH SOME LIGHT SNOW COVER ACROSS THE NORTHERN FORECAST
AREA...SIMILAR TO THIS PAST SATURDAY...TEMPERATURES AGAIN MAY
HANG BELOW 40 BUT EXPECTING AT LEAST TO BE CLOSE AND TOPPING 40
SOUTH. THE FROPA LOOKS TO BE DRY WITH VERY LIMITED MOISTURE
FORECAST.
AS SIGNIFICANT UPPER HEIGHT ANOMALIES DEVELOP OVER THE WEST COAST
AND A ROBUST 150+ KT NORTHERN PACIFIC JET OVERTOPS THIS...THE
PATTERN CONTINUES TO SUPPORT A COLD PUNCH OR TWO LATE IN THE
WEEKEND INTO NEXT WEEK. THE REGION WOULD CERTAINLY LOOK TO HAVE A
CHANCE FOR SNOW AS THIS PATTERN TRANSITION OCCURS...AND RIGHT NOW
DETERMINISTIC MODELS AND ENSEMBLES HINT AT SUNDAY WITH A DIGGING
NORTHERN STREAM SYSTEM. HAVE GONE WITH A SMART BLEND OF MODEL
POPS AT THIS TIME.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* IFR/LIFR TODAY AND TONIGHT.
* REDUCED VIS IN LIGHT SNOW LATER TONIGHT INTO WEDNESDAY.
* NORTHEAST WINDS APPROACHING 10KT LATER THIS AFTERNOON.
RODRIGUEZ/BMD
//DISCUSSION...UPDATED 12Z...
QUICK AND SMALL AREA OF A WINTRY MIX OF FREEZING RAIN/SNOW/PELLETS
STILL PUSHING EAST THROUGH NORTHERN ILLINOIS AT THIS TIME. TIMING
AND DURATION STILL APPEAR TO BE ON TRACK WITH THIS REALLY NOT LONG
LASTING EARLY THIS MORNING...WITH THE OVERALL SIZE ACTUALLY
SHRINKING WITH TIME. THIS WILL QUICKLY PASS WITH THEN MVFR AND IFR
CEILINGS TO QUICKLY PUSH ACROSS THE TERMINALS THROUGH MID MORNING.
IT DOES LOOK LIKE THE WINDOW BETWEEN THIS TRANSITION WILL BE SMALL
AS ROCKFORD HAS ALREADY TRANSITIONED FROM VFR TO IFR IN A MATTER OF
ONE TO TWO HOURS. CONTINUED THAT TREND WITH THE REMAINING
TERMINALS...WITH IFR TO THEN PREVAIL FOR THE REMAINDER OF THE DAY.
APPROACHING SYSTEM TONIGHT WILL LIKELY HELP TO LOWER CEILINGS
FURTHER AS A PERIOD OF LIGHT SNOW WILL BE OBSERVED INTO WEDNESDAY
MORNING. CONFIDENCE WITH EXACT START TIME IS LOWER AT THIS TIME AS
CONDITIONS INITIALLY DONT APPEAR TO BE FAVORABLE FOR SNOW
DEVELOPMENT THIS EVENING. NONETHELESS...SNOW WILL BECOME MORE
PREVAILING WITH TIME TONIGHT. SNOW WILL THEN TAPER OFF DURING THE
MORNING HOURS...BUT WITH CEILINGS LIKELY HOLDING ONTO IFR DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM HIGH CONFIDENCE WITH CIG TRENDS.
* HIGH CONFIDENCE WITH LIGHT SNOW TONIGHT INTO WEDNESDAY...MEDIUM
CONFIDENCE WITH TIMING.
* LOW CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...SLIGHT CHANCE OF LIGHT SNOW.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF LIGHT SNOW.
MONDAY...SLIGHT CHANCE OF LIGHT SNOW.
RODRIGUEZ
&&
.MARINE...
200 AM CST
A COUPLE OF WEAK LOW PRESSURE SYSTEMS WILL TRACK JUST SOUTH OF LAKE
MICHIGAN THROUGH WEDNESDAY...WITH ONE THIS MORNING AND THE OTHER
WEDNESDAY AFTERNOON. WITH HIGH PRESSURE TO THE NORTHEAST THIS
PATTERN WILL BRING NORTHEASTERLY WINDS ACROSS MOST OF THE
LAKE...THOUGH THE GRADIENT IS MODEST AT BEST. THE HIGHEST WINDS
TODAY AND TONIGHT...WITH GUSTS AROUND 20 KT...LOOK TO BE JUST
NORTH OF THE LOW TRACK. THESE EAST-NORTHEAST WINDS SHOULD BE
POINTED INTO THE ILLINOIS NEARSHORE...ESPECIALLY NORTH OF
CHICAGO...BUT CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA.
HIGH PRESSURE WILL MAKE A QUICK PASS OVER THE LAKE LATE WEDNESDAY
NIGHT AND THURSDAY MORNING BEFORE GIVING WAY TO STRONG SOUTHWEST
WINDS. THE PATTERN THURSDAY NIGHT INTO FRIDAY FORECAST BY COMPUTER
MODELS WITH A LOW PRESSURE OF SUB 29.50 INCHES PASSING EASTWARD
ACROSS ONTARIO LOOKS LIKE ONE SUPPORTIVE OF GALES. SO WILL CARRY
SOME 35 KT GUSTS NAMELY ACROSS THE NORTH AND CENTRAL DURING LATE
THURSDAY NIGHT AND FRIDAY. THE FORECAST WINDS COULD END UP
NEEDING TO BE STRONGER IN TIME. THE COLD FRONT WITH THIS SYSTEM
WILL BEGIN USHERING IN A PATTERN MORE SEASONAL FOR LATE JANUARY
WITH COLDER AIR AND SUCCESSIVE SYSTEMS INTO EARLY NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
944 AM CST Tue Jan 20 2015
.UPDATE...
ISSUED AT 940 AM CST TUE JAN 20 2015
Main forecast issue for the rest of today is with cloud cover.
Large area of stratocumulus dropping southeast out of the upper
Mississippi Valley, with the leading edge currently roughly along
a Galesburg to Joliet line, although a finger of lower clouds is
extending as far southeast as Peoria. Latest RAP 925-850 mb layer
humidity plot suggests this should spread over a large part of
central Illinois into early afternoon. Have updated the sky trends
in the zones and grids for this trend. Made some minor
adjustments to the hourly temperature/dew point grids as well, but
no significant changes to the high temperatures were made.
&&
.SHORT TERM...(Today)
ISSUED AT 323 AM CST TUE JAN 20 2015
A fairly potent short-wave trough evident on 08z/2am water vapor
imagery over northeast Iowa brought clouds and a few light rain
showers to the northern half of the KILX CWA earlier this evening.
Latest radar imagery shows a few lingering showers east of the I-55
corridor, while skies have already cleared further west across the
Illinois River Valley. Based on satellite timing tools, all of
central and southeast Illinois will be mostly clear by 12z. As the
wave skirts across northern Illinois and Indiana later today,
additional cloud cover behind this feature along a trailing vort max
will begin to sink southeastward toward the area. Meanwhile,
high/thin clouds associated with a separate system over the Plains
will spill eastward as well. End result will be a sunny start to
the day, with increasing clouds as the day progresses. Most
locations will be partly sunny by mid to late afternoon, with mostly
cloudy conditions noted along/northwest of the Illinois River. It
will be another unseasonably warm day, with high temperatures
climbing about 10 degrees normal for this time of year. Afternoon
readings will range from around 40 degrees northwest of the Illinois
River where clouds will become thickest, to the lower 50s southeast
of I-70.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 323 AM CST TUE JAN 20 2015
Extended forecast continues to look relatively tranquil for mid to
late January, with a series of weak disturbances expected to pass
through the region. System number one has been well advertised for
several days and is still on target for tonight into Wednesday.
Trends have consistently been further north with its track and
associated QPF and the latest model run is no exception. Given this
well-established trend and good agreement among the various models,
have trimmed PoPs to focus chances mainly along/north of I-74. Any
precip that occurs will be quite light, with heavier amounts
expected to remain further north along/north of the I-80 corridor.
With temps initially in the 40s this afternoon, precip may begin as
a rain/snow mix toward midnight around Galesburg, then will
transition to light snow overnight into Wednesday morning. High
temps on Wednesday will climb into the upper 30s and lower 40s, so
snow will transition back to rain or a rain/snow mix by midday.
Little or no snow accumulation is expected across the north.
Once the wave passes to the east of the region, mild and dry weather
is expected Thursday through Saturday, with high temperatures in the
upper 30s/lower 40s gradually climbing back into the lower to middle
40s by Saturday. The next system of interest will arrive by Sunday:
however, model agreement and consistency remains poor. The main
question will be how deep the system becomes as it dives
southeastward out of Canada and carves out a long-wave trough across
the eastern CONUS. GFS is quite aggressive with the amplification
of the wave, indicating a closed 500mb low developing over southern
Iowa/northern Missouri by 00z Mon. This particular solution would
result in a colder atmospheric profile and a slower exit of the
system, which could lead to snow accumulation Sunday night into
Monday. Meanwhile, the ECMWF/GEM/UKMET all feature
open/progressive waves that quickly pass through the region on
Sunday. The latest ECMWF has trended slightly deeper with the
system, but still not as amplified as the GFS. An examination of
the Ensemble GFS and its members reveals the operational GFS is
actually an outlier. As a result, am favoring a faster-moving/weaker
wave late in the weekend. This will likely bring a period of light
precip to the area Sunday into Monday morning. With no source of
cold air to tap into, temps will once again be marginal for snow,
with highs on Sunday reaching the upper 30s and lower 40s. Have
gone with rain or a rain/snow mix during the day accordingly,
changing to light snow Sunday night. A minor accumulation will be
possible before the precip exits Monday morning.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 522 AM CST TUE JAN 20 2015
Skies have cleared across central IL this morning following a
system that passed through last night. Observations are currently
showing mostly VFR visibilities, although patchy MVFR visibility
in fog is present. For a few hours this morning, have included
VCFG in TAFs nearby where rain fell last night, with tempo MVFR BR
at KPIA and KCMI which have had lower visibilities reported this
morning. Meanwhile, region of IFR/MVFR ceilings associated with a
system over northern Plains/Upper Mississippi Valley region will
move into central Illinois through the day. Decreasing ceilings
into MVFR category in TAFs during the afternoon due to this
system, and bringing VCSH and local IFR into KPIA, KBMI, KCMI late
evening due to a chance for light snow showers.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
955 AM EST TUE JAN 20 2015
.SYNOPSIS...
PASSING UPPER LEVEL DISTURBANCES...AND MOISTURE...WILL LEAD TO
LINGERING FLURRIES INTO THIS AFTERNOON. LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED. TONIGHT AND MOST OF WEDNESDAY WILL BE
DRY AND SEASONABLY COLD...WITH WEAK HIGH PRESSURE IN CONTROL. A
FAST MOVING STORM SYSTEM WILL BRING A PERIOD OF LIGHT SNOW OR
FLURRIES WEDNESDAY NIGHT INTO EARLY THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
940 AM UPDATE...VISIBLE SATELLITE SHOWS SHALLOW LOW-LEVEL MOISTURE
AND STRATOCUMULUS CLOUDS THAT LINGERED OVER MUCH OF CENTRAL NY
AND MOST OF PA. A DRIER ARCTIC AIR MASS HAS SLIDE SOUTHWARD INTO
ONEIDA COUNTY AND HAS LED TO CLEARING. MODEL SOUNDINGS CONTINUE
TO SHOW MOISTURE TRAPPED UNDER AN INVERSION MOST AREAS WHICH
LOWERS DURING THE AFTERNOON. THE HRRR SUGGESTS CLEARING IN MOST
AREAS WITH THE NAM12 CONTINUING THE LOW CLDS ESP ACRS NE PA TO THE
CATSKILLS. LOOKING AT THE SATELLITE IMAGERY WILL HAVE PARTIAL
CLEARING WORKING S AND W DURING THE AFTERNOON. WILL KEEP MO CLDY
FROM KAVP TO KELM THRU AFTERNOON. FARTHER N AND E...THERE SHUD BE
SOME BREAKS AND NC NY WILL SEE MORE SUNSHINE. SINCE LOW-LEVEL
TEMPERATURES UNDER THE INVERSION WERE CLOSE TO THE MAX GROWTH FOR
ICE CRYSTALS IT IS NOT HARD FOR CLOUD COVER TO PRODUCE A FEW
FLURRIES AS THE AIR BLOWS UP THE HILLS. SO WILL KEEP SCT FLURRIES
UNTIL AFTERNOON.
340 AM UPDATE... LINGERING LOW-LVL MOISTURE UNDERNEATH AN 850-800
MB CAPPING INVERSION THIS MRNG...280-290 FLOW...AND FAST MOVG MID-
LVL S/WVS...WILL KEEP FLRYS/SCTD LGT SNOW SHWRS GOING THROUGH AT
LEAST 12-15Z...UNDERNEATH MAINLY CLOUDY SKIES.
STARTING DURG THE LATE MRNG AND EARLY AFTN HRS...SOME LOW-LVL
DRYING DOES ATTEMPT TO COME DOWN FROM THE N...WITH WEAK SFC
RIDGING BLDG DOWN FROM ONT/QUE. THUS...WE MAY SEE BREAKS OF
SUNSHINE DVLP BY AFTN...ALG WITH A CESSATION OF FLRYS/SNOW SHWRS.
IT WILL BE SEASONABLY COLD AGN TDY...WITH MAX TEMPS MOSTLY IN THE
20S...EXCEPT FOR A FEW LWR 30S IN THE WYO/LACK VLYS OF NE PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
350 AM UPDATE... TNT AND MOST OF WED WILL BE QUIET/DRY...WITH ABV
MENTIONED SFC HIGH PRES BLDG ACRS UPSTATE NY AND NRN NEW ENG.
CLEAR TO PTLY CLDY SKIES...SPCLY OVER OUR NRN ZNS TNT...ALG WITH A
CHILLY AMS AND SNOW COVER...WILL LEAD TO LOW TEMPS IN THE SINGLE
DIGITS OVER MUCH OF CNY/NE PA. SOME OF OUR NORMALLY COLDER VLYS
COULD SEE SUB-ZERO READINGS BY DAYBREAK WED. BY WED AFTN...HIGHS
SHOULD RECOVER INTO THE 20S-LWR 30S ONCE AGN...UNDERNEATH
INCREASING MID TO HIGH-LVL CLDNS.
WED NGT INTO EARLY THU...WE CONTINUE TO WATCH A S/WV EMERGING FROM
THE NRN PLAINS/UPR LKS RGNS...THEN COMING EWD ACRS NY/PA. AN
ASSOCD WEAK CLIPPER-TYPE SFC LOW IS PROGGED TO TRACK EWD IN
TANDEM...LIKELY ACRS THE OH VLY/PA/NJ. A NARROW SWATH OF LGT SNOW
IS EXPECTED TO ACCOMPANY THIS SYSTEM. HOWEVER...THE EXACT LATITUDE
OF THIS STRIPE OF LGT SNOW REMAINS IN QUESTION (THE NAM FARTHEST N
THROUGH MUCH OF CNY...WHILE THE EC IS FARTHEST S...MOSTLY POINTS
FROM PA SWD). FOR NOW...WE`VE GONE WITH A BLEND OF OUR EXISTING FCST
AND A MODEL COMPROMISE...WHICH WOULD BRING A GENERAL 0.5-1.5" OF
SNOW TO MOST OF THE FA OVERNIGHT WED INTO THU MRNG. LGT SNOW
SHOULD TAPER OFF TO SCTD SNOW SHWRS/FLRYS THU AFTN...AS THE MAIN
FORCED ASCENT SHIFTS EWD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
XTNDD PD WILL BE QUIET AS LTL OVERALL CHG IN THE PTRN IS
XPCTD...AND NO MAJOR SYSTEMS FORECAST. GNRL NW FLOW CONTS EARLY IN THE
PD SO SOME MSTLY LGT LE CANNOT BE RULED OUT AT ANY TIME...BUT THE
BEST CHANCE WILL BE THU NGT AND FRI BEFORE A SFC HIPRES BLDS IN.
WITH THIS HIGH AND INTO THE SAT...FLOW IS MORE WSW SO ANY LE COULD
BE MAINLY NORTH OF THE FCST AREA. SAT NGT A SHRP WV AND STRONG
COLD FNT PASS INCRSG THE CHANCE FOR LE AND BRINGING MUCH COLDER
AIR BACK TO THE REGION.
WITH LTL GOING ON...GNRLY FLWD HPC GUID FOR THE XTNDD PD.THAT
SEEMED TO BRING US INTO GOOD COLLABORATION WITH MOST OF THE
SURROUNDING OFFICES AS WELL.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
GENERALLY VFR AT KAVP. MVFR CIGS AT NY TERMINALS WILL IMPROVE TO
VFR FIRST AT KSYR/KRME/KELM BY MID MORNING. AT KSYR AND KBGM
IMPROVEMENT TO VFR LIKELY TO TAKE LONGER AND PERHAPS NOT UNTIL
AFTER 21Z. VFR TONIGHT WITH A FEW HIGH CLOUDS.
NORTHWEST WINDS AROUND 10 KTS THIS MORNING, BECOMING LIGHT
NORTHWEST THIS AFTERNOON. NEAR CALM OR LIGHT NORTHERLY WINDS AT 5
KTS OR LESS TONIGHT.
OUTLOOK...
TUE/WED...VFR.
WED NGT THU...MVFR PSBL IFR IN SNOW SHWRS AS CLIPPER MVES THRU.
FRI/SAT...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/MLJ
NEAR TERM...DJN/MLJ
SHORT TERM...MLJ
LONG TERM...DGM
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
304 PM PST TUE JAN 20 2015
.SYNOPSIS...
THE SAN JOAQUIN VALLEY WILL SEE A CONTINUATION OF COOL WEATHER UNDER
MOSTLY CLOUDY SKIES ALONG WITH NIGHT AND MORNING FOG. CONDITIONS
OUTSIDE THE VALLEY WILL SEE PARTLY CLOUDY SKIES WITH ABOVE NORMAL
TEMPERATURES.
&&
.DISCUSSION...ABUNDANT HIGH CLOUDS WERE PRESENT OVER THE REGION
THIS AFTERNOON AS AN UPPER TROUGH MOVED SOUTHEAST THROUGH THE AREA
TODAY. MUCH OF THE SAN JOAQUIN VALLEY REMAINS IN A THICK LAYER OF
STRATUS...APPROXIMATELY 1500 FEET DEEP ACCORDING TO THE VISALIA
PROFILER. ADDITIONALLY...PATCHY DRIZZLE WAS REPORTED THROUGH PARTS
OF THE VALLEY. A FEW LOCATIONS IN THE VALLEY REPORTED
DRIZZLE...WITH TULARE...HURON...AND KETTLEMAN HILL ACTUALLY
MEASURING 0.01" OF PRECIPITATION. WITH ABUNDANT CLOUD COVER OVER
THE VALLEY...THERE HAS BEEN VERY LITTLE DIURNAL TEMPERATURE
CHANGE...WITH HIGH TEMPERATURES IN THE UPPER 40S TO LOW 50S AND
OVERNIGHT LOW TEMPERATURES IN THE MID 40S.
THE UPPER TROUGH WILL SHIFT EAST OUT OF THE AREA LATE TONIGHT INTO
EARLY TOMORROW MORNING ALLOWING HIGH PRESSURE TO BRIEFLY BUILD
OVER THE REGION. UNFORTUNATELY THIS WILL DO LITTLE TO NOTHING TO
THE VALLEY STRATUS. THE HIGH RES ARW...HIGH RES NMM...AND HRRR ALL
INDICATE PATCHY DRIZZLE ONCE AGAIN OVER THE VALLEY TONIGHT...WITH
THE ARW AND NMM SHOWING DRIZZLE THROUGH AT LEAST THURSDAY MORNING.
WITH STRATUS FIRMLY IN PLACE...THE TEMPERATURE FORECAST WILL BE A
NEARLY COOKIE CUTTER FROM DAY TO DAY.
ANOTHER UPPER TROUGH WILL MOVE SOUTHEAST TOWARD THE REGION ON
THURSDAY. THE HIGH RES MODELS INDICATE A DRYING OF THE BOUNDARY
LAYER...POSSIBLY ERODING THE STRATUS LAYER. HOWEVER CONFIDENCE IS
LOW AND THE LOW CLOUDS REMAIN IN THE FORECAST. WE WILL CONTINUE TO
MONITOR MODEL TRENDS AND HOPEFULLY GET A BETTER HANDLE OF THE
SITUATION IN THE NEXT 24 HOURS.
OTHERWISE...INTERESTING WEATHER PATTERN SETS UP OVER THE WEEKEND
INTO EARLY NEXT WEEK. AN UPPER RIDGE WILL BE PRESENT OVER
CALIFORNIA WITH A CLOSED UPPER LOW OVER THE SOUTHEASTERN PACIFIC
RESULTING IN A REX BLOCK. AN UPPER TROUGH IN THE EASTERN PACIFIC
WILL SHIFT EAST TOWARD THE REGION MONDAY INTO TUESDAY...WITH THE
UPPER LOW MOVING NORTHEAST. THERE ARE HUGE DISCREPANCIES BETWEEN
THE OPERATIONAL MODELS...THE ENSEMBLE MEANS...AND THE MODEL TRENDS
WITH THE MOVEMENT OF THIS LOW. THERE IS THE POSSIBILITY OF RAIN
MOVING NORTH INTO KERN COUNTY EARLY NEXT WEEK...CONTINUING NORTH
THROUGH THE REST OF THE AREA INTO THE MIDDLE OF THE WORK WEEK. A
SLIGHT CHANCE OF RAIN HAS BEEN ADDED TO THE FORECAST FOR THIS TIME
FRAME...AS NCEPS RELATIVE MEASURE OF PREDICIBILITY IS INDICATING
MEDIUM CONFIDENCE FOR THE UPPER PATTERN. PLEASE CONTINUE TO
MONITOR THE FORECAST FOR THE LATEST INFORMATION.
&&
.AVIATION...
IFR VISIBILITIES WILL PREVAIL IN THE SAN JOAQUIN VALLEY DURING THE
NEXT 24 HOURS WITH LOCAL LIFR/VLIFR VISIBILITIES IN DRIZZLE AND FOG
UNTIL 20Z WEDNESDAY. VFR CONDITIONS CAN BE EXPECTED ELSEWHERE ACROSS
THE CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.
&&
.AIR QUALITY ISSUES...
ON TUESDAY JANUARY 20 2015... FIREPLACE/WOOD STOVE BURNING STATUS
IS: NO BURNING UNLESS REGISTERED IN FRESNO... KERN... KINGS...
MADERA... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 01-20 72:1994 36:1937 55:1901 24:1963
KFAT 01-21 72:1994 39:1937 56:1896 19:1937
KFAT 01-22 70:1994 35:1962 52:1888 25:1945
KBFL 01-20 77:1912 40:1940 56:1969 21:1922
KBFL 01-21 79:1981 40:1937 60:1942 19:1937
KBFL 01-22 76:1981 38:1962 60:1981 19:1937
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...RILEY
AVN/FW...ANDERSEN
SYNOPSIS...JDB
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
957 AM MST TUE JAN 20 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 331 AM MST TUE JAN 20 2015
LAST EVENING`S PROGRESSIVE SHORTWAVE TROUGH WAS QUICKLY EXITING INTO
THE CENTRAL PLAINS EARLY THIS MORNING BUT FAVORABLE NW OROGRAPHIC
FLOW AND THE NOSE OF A TRAILING UPPER JET SHOULD KEEP SNOW OVER THE
NAN AND CNTL CO MTNS NEARER THE DIVIDE UNTIL ABOUT SUNRISE PER
THE 08Z HRRR MODEL. WILL CONTINUE THE WINTER WEATHER ADVISORY FOR
THE VAIL PASS AREA THOUGH IT MAY BE A BIT LONG IN DURATION. FOG
PERSISTS IN THE EASTERN UINTA BASIN WHERE A DENSE FOG ADVISORY
CONTINUES.
FOG ALSO DEVELOPED IN THE GUNNISON AREA EARLY THIS MORNING FOLLOWING
SOME LIGHT SNOW LAST EVENING. FOG WAS QUITE NOTICEABLE ON THE
WSCU CAMPUS WEBCAM IN GUNNISON. THE GUNNISON AIRPORT OBSERVATION
HAS BEEN DOWN TO 1/4 MILE VISIBILITY AT TIMES...AND RAP FORECAST
SOUNDING INDICATED FOG TO PERSIST THIS MORNING. ISSUED A DENSE
FOG ADVISORY FOR THE UPPER GUNNISON RIVER VALLEY.
CONTINUED DRYING OF THE AIRMASS SHOULD LEAD TO PARTLY TO MOSTLY
SUNNY SKIES ACROSS MOST OF THE FORECAST AREA THIS AFTERNOON. DO NOT
SEE MUCH MIXING FOR THE EASTERN UINTA BASIN TODAY SO WILL CARRY HAZE
AND SOME CLOUDS THERE THIS AFTERNOON THEN PATCHY FOG AGAIN TONIGHT.
A PACIFIC TROUGH APPROACHING THE NAN CA COAST WILL DEEPEN AND
DROP DOWN INTO THE SOUTHWEST BY WED MORNING WHILE ANOTHER
SHORTWAVE DISTURBANCE MOVES DOWN THE EAST SIDE OF THE ROCKIES. 400
MB POTENTIAL VORTICITY SHOW THESE TWO TROUGHS PHASING WITH THE
RESULTING TROUGH AXIS STRETCHING FROM THE UPPER MIDWEST ACROSS THE
FOUR CORNERS AND AZ BY LATE WED. MODELS AGREE ON A PRECIPITATION
BAND DEVELOPING JUST TO OUR SOUTH ACROSS NAN AZ/NAN NM...THOUGH
THEY HAVE BEEN KNOWN TO PLACE IT NORTHWARD IN EARLIER MODEL RUNS.
WILL MAKE LITTLE CHANGE TO THE CURRENT FORECAST OF A CHANCE OF
SNOW FOR THE SAN JUANS AND SOUTHWARD WED WITH A FEW POCKETS OF
LIGHT SNOW OVER THE CENTRAL MTNS IN COOLER BUT WEAK NORTHERLY
FLOW. NE UT AND NW CO LOOK MOSTLY SUNNY ON WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 331 AM MST TUE JAN 20 2015
THE FOCUS OF PRECIP WILL CONTINUE TO DROP SOUTH OVERNIGHT
WEDNESDAY AND THOUGH BEST CHANCES FOR PRECIP WILL BE IN NM...SOME
SHOWERS WILL LIKELY CONTINUE FOR THE SAN JUANS AND CENTRAL MTNS.
NOT MUCH IN THE WAY OF ACCUMULATION THOUGH AS THE ATMOSPHERE
REMAINS RELATIVELY DRY. MADE MINIMAL CHANGES TO GOING FORECAST AS
THIS IS CAPTURED WELL.
WHILE THE FORCING FOR PRECIP LOOKS TO BE A DEFORMATION ZONE...A
RELATIVELY WEAK AND DRY COLD FRONT WILL ALSO AID IN SOME LIFT.
HOWEVER...WITH LITTLE MOISTURE TO WORK WITH THE ONLY REAL SENSIBLE
WX FELT WILL BE COLD TEMPS. MOS GUIDANCE SHOWS HI TEMPS DROPPING
WEDNESDAY AND THURSDAY BEFORE REBOUNDING FRIDAY AND BEYOND. LOW
TEMPS FOR MANY LOCATIONS WILL BE IN THE SINGLE DIGITS TO SUBZERO
RANGE THURSDAY AND FRIDAY MORNING WHICH CERTAINLY SEEMS REASONABLE
AS NORTHERLY FLOW USHERS IN MUCH COLDER AIR TO THE REGION.
BY THURSDAY NIGHT...THE FRONT AND TROUGH WILL HAVE SHIFTED WELL
TO THE SOUTH AS FLOW BECOMES MORE NWLY. A LARGE AREA OF HIGH
PRESSURE WILL THEN BEGIN TO BUILD IN TO THE DESERT SW AS WEAK
WAVES START TO DROP DOWN FROM THE PACNW. SOME LIGHT PRECIP IS
POSSIBLE FOR THE NAN MTNS FRIDAY NIGHT WITH COVERAGE INCREASING A
BIT SUNDAY INTO MONDAY. WHILE NOTHING TOO IMPRESSIVE YET...THESE
TYPES OF LITTLE SYSTEMS SOMETIMES HAVE A HABIT OF DROPPING A QUICK
FEW INCHES OF SNOW. BLENDED GUIDANCE NOT IMPRESSED EITHER WITH SLT
CHC SNOW FOR THOSE TIMES WHICH SEEMS REASONABLE FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 955 AM MST TUE JAN 20 2015
STATUS AND FOG CONTINUE TO PLAGUE FLIGHT OPERATIONS AT KVEL AND
KDRO WITH IFR IN CONTROL THIS MORNING. WEB CAMS INDICATE THIS IS
VERY LOCALLIZED TO THE AIRFIELDS AND SOME IMPROVEMENT IS LIKELY BY
MID AFTERNOON. KASE AND KEGE ARE VFR BUT REMAIN UNDER ILS AS CIGS
HOOVER AROUND 4-5KFT AGL. AGAIN IMPROVEMENT IS EXPECTED HERE AS
WELL. VFR CONDITIONS SHOULD PREVAIL AT THESE LOCATIONS OVER THE
NEXT 24 HOURS AND WILL BE MONITORING SATELLITE TREND FOR KVEL AND
KDRO. PERSISTENCE WOULD DICTATE KVEL WILL BE IN IFR/LIFR AGAIN
TONIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...DENSE FOG ADVISORY UNTIL NOON MST TODAY FOR COZ014.
UT...DENSE FOG ADVISORY UNTIL NOON MST TODAY FOR UTZ024.
&&
$$
SHORT TERM...JAD
LONG TERM...TGR
AVIATION...15
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
305 PM CST TUE JAN 20 2015
.SHORT TERM...
339 AM CST
THROUGH TODAY...
MAIN FORECAST CHALLENGES/CONCERNS TODAY ARE WITH A BRIEF WINDOW OF
FREEZING RAIN OR FREEZING DRIZZLE THIS MORNING ACROSS NORTHERN
ILLINOIS...AND THEN INCREASING CLOUD COVER AND CHANCES FOR PRECIP
VERY LATE THIS AFTERNOON.
BEEN MONITORING AN AREA OF PRECIP WHICH HAS MOVED SOUTHEAST
THROUGH IOWA AND SOUTHWEST WISCONSIN THIS MORNING...APPROACHING
THE RFD AREA AT THIS TIME. MAIN AREA OF PRECIP ACROSS THE REGION
HAS REMAINED WELL NORTH OF THE CWA ACROSS WISCONSIN AS SURFACE LOW
HAS DROPPED SOUTHEAST INTO NORTHWEST ILLINOIS THIS MORNING...BUT
STRONG VORT MAX HAS ENABLED FOR THE CONTINUED PRECIP DEVELOPMENT
FURTHER TO THE SOUTHWEST. THIS WILL LIKELY CONTINUE OVER THE NEXT
SEVERAL HOURS...MOVING INTO NORTH CENTRAL ILLINOIS OVER THE NEXT
1-2 HOURS AND THEN INTO NORTHEAST ILLINOIS AROUND THE 13Z TIME
FRAME. FORECAST SOUNDINGS INDICATING A MARGINAL SETUP FOR SNOW
DEVELOPMENT WITH RAIN THE LIKELY PRECIP TYPE. UPSTREAM OBS HAVE
SUPPORTED THIS WITH BOTH RAIN AND SNOW BEING REPORTED ACROSS IOWA
AND WISCONSIN. ONCE AGAIN...DONT ANTICIPATE THIS TO CHANGE ACROSS
THE CWA AND WITH AIR TEMPS AROUND FREEZING...AM A LITTLE CONCERNED
FOR A BRIEF WINDOW OF FREEZING RAIN OR FREEZING DRIZZLE AS THIS
PUSHES THROUGH. THIS WILL LIKELY BE LIGHT AND VERY BRIEF...UNDER
ONE HOUR...BUT STILL COULD CAUSE ISSUES THIS MORNING. THIS WILL
ESPECIALLY BE THE CASE ACROSS NORTHWEST AND NORTH CENTRAL ILLINOIS
WHERE TEMPS HAVE BEEN COOLER. ANY FREEZING COMPONENT WILL LIKELY
BECOME LESS OF A PROBLEM AS IT APPROACHES NORTHEAST ILLINOIS WITH
TEMPS SLIGHTLY WARMER. HAVE ISSUED AN SPS THIS MORNING AND WILL
CONTINUE TO MONITOR THE SOUTHEASTWARD MOVEMENT AND TEMP TRENDS FOR
AREAS ACROSS NORTHEAST ILLINOIS.
SKIES WILL LIKELY BE PARTLY CLOUDY TO PARTLY SUNNY TO START OFF
THIS MORNING AS CLOUD COVER OVER EAST CENTRAL ILLINOIS AND
NORTHWEST INDIANA DEPART...AND THEN AS LOW STRATUS DROPS SOUTH OUT
OF WISCONSIN. THIS SOUTHWARD MOVING STRATUS WILL BRING A RETURN TO
MOSTLY CLOUDY SKIES BY THE AFTERNOON FOR ALL AREAS...WITH ABOVE
NORMAL TEMPS STILL APPEARING LIKELY. DID LOWER TEMPS FOR TODAY
MAINLY OVER NORTHERN ILLINOIS WHERE STRATUS WILL APPROACH
QUICKER...BUT LEFT TEMPS OVER THE SOUTHERN HALF ALONE WHERE HIGHS
COULD REACH AROUND 40. HAVE POPS INCREASING VERY LATE IN THE
AFTERNOON TODAY MAINLY FOR THE NORTHERN HALF OF THE CWA BUT THEY
MAY BE TOO QUICK AS THE ARRIVAL OF THE NEXT SYSTEM AND PRECIP NOT
LIKELY UNTIL LATER THIS EVENING.
RODRIGUEZ
&&
.LONG TERM...
339 AM CST
TONIGHT THROUGH MONDAY...
A NICELY DEFINED MID-LEVEL CIRCULATION ON WATER VAPOR IMAGERY THIS
MORNING OVER NORTH DAKOTA WILL RIDE AN UPPER LEVEL PV INTRUSION
INTO THE FORECAST AREA LATE TONIGHT. IN ADVANCE OF THIS LOW
AMPLITUDE WAVE...SUBTLE ISENTROPIC ASCENT SHOULD GRADUALLY
INCREASE ALONG THE 900-700MB THERMAL BOUNDARY ATOP THE AREA. WITH
LOW-LEVEL SATURATION ALREADY IN PLACE BY THAT TIME...LIGHT
PRECIPITATION SHOULD EXPAND IN COVERAGE THIS EVENING...MAINLY
NORTH OF I-80. GIVEN THE FORCING IS LIGHT AT FIRST AND LIMITED ICE
CRYSTAL INITIATION PER FORECAST SOUNDINGS...A PERIOD OF LIGHT
LIQUID COULD OCCUR AT FIRST. SURFACE TEMPERATURES LOOK TO BE AT
OR POSSIBLY A BIT ABOVE FREEZING...SO NOT TOO CONCERNED ABOUT
THAT IF IT OCCURS EARLY THIS EVENING. FORCING INCREASES LATE IN
THE EVENING AND ESPECIALLY OVERNIGHT SO THAT CONFIDENCE INCREASES
PRECIPITATION TYPE WOULD CHANGE TO SNOW.
IT TAKES A WHILE FOR THIS SYSTEM TO MOVE THROUGH THE AREA WITH THE
VORT MAX STILL FORECAST OVER NORTHWEST INDIANA AT MIDDAY WEDNESDAY.
THIS INDICATES A LIGHT SNOW EVENT OF LONGER DURATION...AGAIN
ESPECIALLY FOR AREAS NORTH OF I-80. WHILE THERE WILL LIKELY BE
BREAKS IN THE SNOW DUE TO THE OVERALL MARGINAL
FORCING...ACCUMULATIONS OF AROUND ONE TO ONE AND A HALF INCHES
REMAIN FORECAST TO MATERIALIZE FROM THIS EVENING THROUGH MIDDAY
WEDNESDAY WITH SHARPLY LESSER AMOUNTS SOUTH OF I-80. RATES SHOULD
MAINLY BE LIGHT WITH LIMITED MESOSCALE FORCING...THOUGH AS THE
SNOW GROWTH ZONE LOWERS BY DAYBREAK WEDNESDAY SOME FORCING COULD
BETTER EXIST IN THE SNOW GROWTH AREA TO HELP INCREASE EFFICIENCY.
WILL NOT ISSUE ANY SPS AT THIS TIME WITH IT STILL BEING 24 HOURS
OUT AND TO AVOID CONFUSION WITH CURRENT SPS OUT FOR THIS MORNINGS
LIGHT FREEZING PRECIPITATION. PLUS IT WILL GIVE THE DAY CHANCE A
BETTER OPPORTUNITY TO REFINE DETAILS.
SOME LIGHT SNOW OR FLURRIES WILL REMAIN POSSIBLE WEDNESDAY AFTERNOON
AND EVENING ACROSS THE ENTIRE AREA WITH THE WAVE SHEARING AS IT
MOVES THROUGH. TEMPERATURES ARE NOT FORECAST TO RISE MUCH
WEDNESDAY GIVEN AMPLE CLOUDINESS.
COLDER AND MORE SEASONAL AIR DOES FILTER IN BEHIND THIS SYSTEM FOR
WEDNESDAY NIGHT INTO THURSDAY. LIMITED HEIGHT RISES AND SUPPRESSION
POINT TOWARD LOW CLOUDS HANGING AROUND...POSSIBLY EVEN THROUGH
THURSDAY NIGHT. SO HAVE LOW TEMPERATURES WEDNESDAY NIGHT STILL
ONLY FORECAST IN THE MID 20S.
AS THE PATTERN BEGINS TO AMPLIFY OVER THE NORTH AMERICAN WEST COAST
INTO CANADA...A STRONG LOW WILL MOVE NORTH OF THE GREAT LAKES AND
SWING A COLD FRONT INTO OUR REGION FRIDAY NIGHT. AHEAD OF THIS
SYSTEM...FRIDAY LOOKS LIKE A BREEZY DAY WITHIN A MODEST WARM SECTOR.
WITH SOME LIGHT SNOW COVER ACROSS THE NORTHERN FORECAST
AREA...SIMILAR TO THIS PAST SATURDAY...TEMPERATURES AGAIN MAY
HANG BELOW 40 BUT EXPECTING AT LEAST TO BE CLOSE AND TOPPING 40
SOUTH. THE FROPA LOOKS TO BE DRY WITH VERY LIMITED MOISTURE
FORECAST.
AS SIGNIFICANT UPPER HEIGHT ANOMALIES DEVELOP OVER THE WEST COAST
AND A ROBUST 150+ KT NORTHERN PACIFIC JET OVERTOPS THIS...THE
PATTERN CONTINUES TO SUPPORT A COLD PUNCH OR TWO LATE IN THE
WEEKEND INTO NEXT WEEK. THE REGION WOULD CERTAINLY LOOK TO HAVE A
CHANCE FOR SNOW AS THIS PATTERN TRANSITION OCCURS...AND RIGHT NOW
DETERMINISTIC MODELS AND ENSEMBLES HINT AT SUNDAY WITH A DIGGING
NORTHERN STREAM SYSTEM. HAVE GONE WITH A SMART BLEND OF MODEL
POPS AT THIS TIME.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* VARIABLE VISIBILITY WITH FG/BR IN THE REGION AND SNOW
OVERSPREADING THIS EVENING/TONIGHT.
* NORTHEAST WINDS AOA 10KT MID TO LATE THIS AFTERNOON.
* IFR/LIFR CIGS.
BMD
//DISCUSSION...UPDATED 18Z...
SURFACE LOW LIES OVER FAR NE IL AND NW IN THIS AFTERNOON WITH
TROUGHING EXTENDING NORTHWEST ACROSS NORTHWEST ILLINOIS. WINDS
WITHIN THE FRONTAL TROUGH ARE LIGHT AND FOG IS REDUCING VSBY TO LESS
THAN A MILE AT TIMES...BUT AS THE TROUGH SAGS SOUTH THROUGH THE
EVENING...EXPECT NORTH/NORTHEAST WINDS TO PICKUP SLIGHTLY BEHIND THE
DEPARTING LOW. NORTHEAST WINDS IN EXCESS OF 10 KTS ARE POSSIBLE
STARTING MID AFTERNOON AT ORD. PRIMARILY IFR CIGS ARE EXPECTED TO
PERSIST THROUGH THE REMAINDER OF THE TAF PERIOD LOWERING TO LIFR
THIS EVENING/TONIGHT AS AN UPPER LEVEL DISTURBANCE DIGS ACROSS THE
MIDWEST WITH SNOW OVERSPREADING THE REGION. PRECIPITATION IS
EXPECTED TO INITIALLY START AS DRIZZLE OR A DRIZZLE/SNOW MIX BEFORE
CHANGING TO ALL SNOW MID TO LATE THIS EVENING. LIGHT SNOW WILL
CONTINUE OVERNIGHT THROUGH MIDDAY WEDNESDAY WITH AN INCH OR TWO
ACCUMULATION POSSIBLE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* LOW-MEDIUM CONFIDENCE IN VSBY TRENDS.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...LOW-MEDIUM IN SPEEDS
MAINLY THIS AFTERNOON.
* MEDIUM CONFIDENCE IN PRECIP TYPE/TIMING.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...SLIGHT CHANCE OF LIGHT SNOW.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF LIGHT SNOW.
MONDAY...SLIGHT CHANCE OF LIGHT SNOW.
RODRIGUEZ
&&
.MARINE...
304 PM CST
FOR HEADLINES...GALES ARE IN THE FORECAST FOR THE NORTH HALF OF THE
LAKE THURSDAY NIGHT INTO FRIDAY MORNING...BUT IT IS STILL TOO FAR
OUT TO PUT ANY HEADLINES OUT YET. FOR THE NEARSHORE WATERS...A
SMALL CRAFT ADVISORY MAY BE NEEDED FOR THE IL WATERS FRIDAY...MAYBE
INTO FRIDAY EVENING. IT STILL LOOKS LIKE A MARGINAL EVENT SO WILL
HOLD OFF WITH ANY HEADLINES.
A WEAK LOW IS OVER SOUTHEAST INDIANA AND ANOTHER WEAK LOW WILL MOVE
OVER NORTHERN IL TOMORROW MORNING. NORTHEAST WINDS WILL DIMINISH TO
5 TO 10 KT OVERNIGHT OVER THE NORTH HALF WHILE THE SOUTH HALF WILL
SEE NORTHEAST WINDS DIMINISH TO 10 TO 15 KT OVERNIGHT. WINDS BECOME
NORTH BEHIND THE LOW TOMORROW AFTERNOON. WINDS CONTINUE TO BACK TO
WEST THURSDAY AS HIGH PRESSURE SPREADS OVER THE REGION. THE
GRADIENT TIGHTENS OVER THE NORTHERN HALF OF THE LAKE AS THE HIGH
SHIFTS SOUTH AND A LARGE LOW MOVES OVER ONTARIO LATE THURSDAY NIGHT
INTO FRIDAY MORNING. SOUTHWEST WINDS INCREASE TO LOW END GALES OVER
THE NORTH HALF THURSDAY NIGHT...WITH SOUTHWEST WINDS TO 30 KT ACROSS
THE ENTIRE LAKE FRIDAY AFTERNOON. THE LOWS COLD FRONT SWINGS OVER
THE LAKE FRIDAY NIGHT WITH WINDS BECOMING WEST 15 TO 20 KT. WINDS
THEN SHIFT TO NORTHWEST SATURDAY. HIGH PRESSURE QUICKLY PASSES OVER
THE LAKE SATURDAY NIGHT AND ANOTHER LOW IS EXPECTED TO MOVE OVER
ILLINOIS SUNDAY. GUIDANCE CONTINUES TO DIFFER ON THE TIMING AND
EXACT LOCATION OF THIS LOW...BUT BOTH LONG TERM GUIDANCE MEMBERS
HAVE THE LOW PASSING SOUTH OF THE LAKE.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
253 PM CST Tue Jan 20 2015
.SHORT TERM...(Tonight)
ISSUED AT 245 PM CST TUE JAN 20 2015
Lingering sunshine is rapidly fading across the CWA, as the low
cloud deck has advanced as far southeast as Decatur and Paris, while
mid and high clouds spread east from Missouri. The lower clouds have
stopped the temperature rise in the north with mid/upper 30s this
afternoon, while mid 40s to around 50 degrees were observed further
south where the sunshine had lingered the longest.
Main forecast concern for tonight is with the clipper system dropping
southeast from South Dakota this afternoon. Morning model suite is
in good agreement with a low track roughly along a Moline to Kankakee
line after midnight. With this type of system, the highest snow
chances are generally along/north of the track, and the forecast
soundings across our northern CWA show little in the way of snow-
generating ice crystals in the -10 to -20C layer. However, the
soundings are moist enough below 750 mb that some light snow should
be a possibility with just enough lift passing through, mainly after
midnight. Snow threat should mainly be from about Macomb to Bloomington
northward, although some light snow may make it as far southeast as
Champaign and Danville toward sunrise.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 245 PM CST TUE JAN 20 2015
Several low amplitude shortwaves to affect the forecast area this
period bringing low chance POPs to the region along with temperatures
continuing to average above normal. The wave that brings our northern
areas a little snow tonight into Wednesday will be shifting to our
east during the afternoon hours. The weak surface low associated with
the shortwave is still forecast to pass to our north, roughly along
the I-80 corridor with the better threat for light accumulating snows
along and north of the track of the low. As the low passes to our
east later in the day, there may be enough cyclonic flow/weak cold
air advection for some scattered flurries across the north into Wed.
night.
There is a lull in the parade of shortwaves tracking from northwest
to southeast into our area until late Saturday night or Sunday when
a stronger wave is forecast to arrive in our area. This wave is
forecast to dig sharply southeast into the mean longwave trof position
with a surface wave then expected to shift across parts of Illinois
during the day Sunday. Once again, the model consistency with this
feature continues to be poor at best. The latest ECMWF now tracks
the low further northeast than the GFS, which would translate to more
of a rain/snow mixture, while the 12z GFS operation model solution
would lean more towards a period of light snow during the day. The
latest GFS ensemble mean takes the storm system across north central
Illinois with the 12z UK and GEM models also trending further north
and east. At this point, not very confident the models have a decent
enough handle on the wave for Sunday, so no significant changes will
be made to the timing of the precip into our area along with precip
types on Sunday. Will keep the chances for snow or rain in the morning
across the forecast area, and then mainly rain during the afternoon
based on the further northeast track to the surface wave which helps
edge temperatures up close to 40 degrees Sunday afternoon.
Will continue with low chance POPs for light snow Sunday night as
the system shifts off to our southeast with flurries possible on
Monday due to low level cold advection/cyclonic flow in the wake
of the storm system. The next upper level wave will be fast
approaching from the northwest on Tuesday, but once again, the
main surface low will track well to our north keeping us on the
mild side for late January with not much in the way of rain or
snow to deal with.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1132 AM CST TUE JAN 20 2015
Area of IFR ceilings dropping southeast this afternoon, and should
be reaching the KSPI-KCMI corridor by 19Z. Ceilings 800-1200 feet
expected through the afternoon. Latest HRRR indicates some
scouring of the low clouds taking place west to east this evening,
but have only indicated this for KSPI for now, as the areas
further east/north will be coming under the influence of a fast
moving clipper system now in South Dakota. Have maintained the
VCSH from KPIA-KCMI for now, but forecast soundings would suggest
more of a drizzle/snow grains profile as the better ice crystal
generation remains in northern Illinois. Northwest winds to trend
southwest this evening ahead of the clipper, before going back
toward the west tomorrow morning following its passage. Have
maintained some high IFR/low MVFR conditions after the passage as
well.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Smith
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS GOODLAND KS
139 PM MST TUE JAN 20 2015
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 139 PM MST TUE JAN 20 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS NW
FLOW IN PLACE FROM THE CANADIAN ROCKIES AND INTO THE SOUTHERN
PLAINS. SHORTWAVE TROUGH AXIS FROM LAST NIGH HAS SHIFTED
EAST..WITH UPSTREAM THERE IS ANOTHER WEAK SHORTWAVE IN THE
NORTHERN STREAM OVER ALBERTA CANADA. IN THE SOUTHERN STREAM A
STRONGER SHORTWAVE TROUGH IS MOVING ONSHORE OVER SOUTHERN
CALIFORNIA.
THIS AFTERNOON...LOW TO MID CLOUD SHIELD ASSOCIATED WITH DECAYED
PRECIPITATION BAND HAS SHIFTED SOUTH. 950-850 MB THETA E LAPSE
RATES INDICATE SHALLOW UNSTABLE LAYER THAT HAS LED A FEW POCKETS
OF SPRINKLES DEVELOPING OVER EASTERN WYOMING/NORTHEAST
COLORADO...WHICH IS CURRENTLY TRANSITIONING SOUTH AND EAST. THIS
WILL BE TIED TO DAYTIME HEATING AND I DO NOT ANTICIPATE ANY
MEASURABLE PRECIP WITH THIS ACTIVITY.
TONIGHT-WEDNESDAY...NORTHERN AND SOUTHERN STREAM SHORTWAVE TROUGHS
WILL MERGE AND DEEPEN LATE TONIGHT WITH NOSE OF H3 JET SLIDING
OVER EASTERN COLORADO/NORTHWEST KANSAS. AS THIS UPPER LOW DEEPENS
BETTER FORCING WILL MAINLY BE OVER EASTERN COLORADO...LIKELY
SOUTHWEST OF OUR CWA. DESPITE THIS...THERE SHOULD BE ENOUGH
FORCING FOR LIGHT SNOW DEVELOPMENT ACROSS THE SOUTHWEST PORTIONS
OF OUR CWA...WITH BEST CHANCES IN THE 12Z-20Z TIME FRAME. I COULD
SEE AROUND ONE INCH OF SNOW ACCUMULATIONS OVER WESTERN PARTS OF
KIT CARSON AND CHEYENNE COUNTIES IN COLORADO...WITH LESS THAN ONE
INCH FURTHER EAST. ALTHOUGH THERE IS AN OVERLAPPING PRECIP SIGNAL
FURTHER NORTHEAST INTO NORTHWEST KANSAS...TRACK OF MAIN UPPER LOW
AND POSITION OF UPPER LEVEL DIVERGENCE LOWERS CONFIDENCE IN LIGHT
SNOW OVER NW KANSAS. I TAPERED POPS TO THE NORTHEAST IN LINE WITH
CONSENSUS...WITH AND HAVE ACTIVITY WINDING DOWN DURING THE
AFTERNOON AS UPPER LEVEL FORCING SHIFTS SOUTH.
TEMP FORECAST WED MAY BE ON THE COLDER SIDE AS H85 TEMPS AROUND -4C
RANGE ARE ADVERTISED BY MOST GUIDANCE. WITH CLOUD COVER/PRECIP IN
THE WEST THROUGH THE EARLY AFTERNOON WE MAY NOT SEE MUCH WARMING
AT ALL...AND TEMPS HOVERING AROUND OR BELOW FREEZING. IN THE EAST
WE MAY SEE SOME BREAKS IN CLOUD COVER BY THE AFTERNOON...WHICH
COULD ALLOW TEMPS TO RECOVER INTO THE LOW 40S. NOT AN EASY TEMP
FORECAST AS POSITION OF PRECIP/CLOUD COVER WILL DETERMINE CUTOFF
IN SUB FREEZING HIGHS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1239 PM MST TUE JAN 20 2015
PRECIPITATION SHOULD END BY 00Z THURSDAY AS SHORTWAVE TROUGH
CONTINUES TO MOVE SOUTH. SHORTWAVE RIDGING WILL FOLLOW ON THURSDAY
WITH DRY CONDITIONS AND TEMPERATURES NEAR NORMAL. NORTHWEST FLOW
WILL RETURN ON FRIDAY AND CONTINUE THROUGH THE WEEKEND WITH A
COUPLE OF EMBEDDED WEAK DISTURBANCES. ONE MOVES THROUGH ON FRIDAY
BUT WILL LACK ADEQUATE LOW LEVEL MOISTURE FOR MORE THAN A FEW
AFTERNOON SPRINKLES AS TEMPERATURES WARM TO THE LOWER 50S. ANOTHER
STRONGER SYSTEM WILL MOVE THROUGH THE NORTHERN PLAINS AND UPPER
MISSISSIPPI RIVER VALLEY SATURDAY NIGHT AND SUNDAY. THE UPPER
DYNAMICS WILL BE TOO FAR AWAY FOR PRECIPITATION CHANCES...THOUGH
IT WILL CREATE A TIGHT HEIGHT AND PRESSURE GRADIENT FOR WINDY
CONDITIONS ON SUNDAY ESPECIALLY IN EASTERN SECTIONS OF THE LOCAL
AREA LIKE MCCOOK AND HILL CITY. AN UPPER RIDGE WILL BUILD WEST
ACROSS THE ROCKIES AND ADJACENT PLAINS EARLY NEXT WEEK RESULTING
IN DRY CONDITIONS AND MUCH ABOVE NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1030 AM MST TUE JAN 20 2015
PATCHY DENSE FOG HAS DEVELOPED OVER PARTS OF EASTERN COLORADO
IMMEDIATELY BEHIND LIGHT RAIN/SNOW THAT HAS TRANSITIONED WELL
SOUTH OF INTERSTATE 70. SHORT RANGE GUIDANCE INDICATES THIS FOG
SHOULD REMAIN WEST OF KGLD. WITH CLEARING SKIES AND WARMING
TEMPERATURES THIS FOG SHOULD QUICKLY BURN OFF...SO I DECIDED TO
LEAVE MENTION OUT OF THE TAF FOR FOR NOW. AT BOTH KGLD AND KMCK
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD...THOUGH
WITH LIGHT SNOW POSSIBLY DEVELOPING LATE IN THE TAF PERIOD IN
EASTERN COLORADO THERE IS A CHANCE CONDITIONS COULD DROP AT KGLD
TO MVFR OR LOWER. NOT A LOT OF CONFIDENCE AS THE TRACK OF THE
UPPER LEVEL DISTURBANCE SHOULD FAVOR LOCATIONS SOUTH OF
INTERSTATE 70.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
536 PM EST TUE JAN 20 2015
.UPDATE...
ISSUED AT 535 PM EST TUE JAN 20 2015
LATEST STLT IMAGERY INDICATES LK INDUCED VORTEX E OF THE KEWEENAW IS
TENDING TO TURN MORE TO THE NNE AND AWAY FM THE KEWEENAW PENINSULA.
THIS MOTION IS IN LINE WITH THE LLVL SSW FLOW THIS MESOVORTEX IS
ENCOUNTERING ON THE NRN FLANK OF SFC RDG AXIS ORIENTED E-W ACROSS
UPR MI. OPTED TO LOWER POPS OVER THE KEWEENAW FOR THIS EVNG BASED ON
THIS CHANGE IN TRACK.
CONSIDERING THE DRYNESS OF THE AIRMASS IN PLACE...WITH PWAT IN THE
0.10 TO 0.15 RANGE...OPTED TO LOWER FCST MIN TEMPS OVER THE ERN CWA
WHERE SKIES ARE LIKELY TO REMAIN MOCLR AND WINDS LGT THRU THE NGT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EST TUE JAN 20 2015
WATER VAPOR LOOP AND RUC ANALYSIS INDICATES A NW FLOW OVER THE
REGION AS THE MAIN SHORTWAVE EMBEDDED IN THIS FLOW IS WELL SW OF THE
UPPER LAKES. VIS SATELLITE LOOP SHOWS LOW CLOUDS PERSISTING OVER THE
W-SW FCST AREA WITH MOSTLY SUNNY SKIES ACROSS THE NCNTRL AND ERN
FCST AREA. MESOSCALE LOW IS EVIDENT JUST EAST OF THE KEWEENAW AND
MOVING SLOWLY EAST.
TONIGHT...LATEST HIGH RES MODELS HAVING A POOR TIME RESOLVING
MESOSCALE FEATURE EAST OF THE KEWEENAW THIS EVENING. AS A
RESULT...HAD TO ADJUST POPS UP TO 50-60 PCT OVER THE TIP OF
THE KEWEENAW AT LEAST THROUGH THIS EVENING TO ACCOUNT FOR THE LES
POTENTIAL. ALSO BUMPED UP SNOW ACCUMULATION TO 1-2 INCHES OVER
THE TIP OF THE KEWEENAW THROUGH THIS EVENING BUT THIS MAY BE TOO
CONSERVATIVE GIVEN FAIRLY IMPRESSIVE LOOK TO THE MESOLOW ON VISIBLE
SATELLITE.
ELSEWHERE TONIGHT TEMPS AND CLOUDS WILL BE THE MAIN CONCERN AND
DETERMINING HOW FAR WEST THE CLEARING LINE REACHES INTO SW UPPER MI
THIS EVENING. THIS WILL HAVE A BIG IMPACT ON MIN TEMPS. AT A
MININUM...WHERE THERE IS CLEARING...SHOULD SEE TEMPS LOWERING INTO
AT LEAST THE SINGLE DIGITS BLO ZERO AND PROBABLY WILL REACH COLDER
THAN -10F AT SOME OF THE COLDER EASTERN INTERIOR LOCATIONS. WILL
KEEP TEMPS CLOSER TO 10-12F OVER THE FAR WEST WHERE CLOUDS SHOULD
PERSIST THROUGH THE NIGHT.
WEDNESDAY...WEAK SHORTWAVE MOVING DOWN FROM MANITOBA/NRN ONTARIO
WILL PUSH A SURFACE TROUGH INTO NW UPPER MI/SCNTRL LAKE SUPERIOR.
LOOK FOR THIS TROUGH TO BECOME THE FOCUS FOR SOME LIGHT LES AS 850
MB TEMPS LINGER AROUND -11C. WILL MAINTAIN SLIGHT CHC TO LOW CHC
POPS OVER NW AND NCNTRL ZONES. EXPECT TEMPS TO REBOUND FM CHILLY
OVERNIGHT LOWS AND REACH INTO THE LOWER 20S EAST TO MID TO UPPER 20S
WEST AND CENTRAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 435 PM EST TUE JAN 20 2015
A TROUGH OF LOW PRESSURE WILL REMAIN ACROSS EASTERN CANADA AND MUCH
OF THE EASTERN U.S. THROUGH THE PERIOD...WITH A RIDGE ACROSS THE FAR
W. AS A RESULT...A SERIES OF WAVES WILL DIVE S ACROSS THE UPPER
GREAT LAKES REGION. HIGH TEMPERATURES WILL GENERALLY HOVER IN THE
20S TO LOW 30S...WHICH IS NEAR TO JUST SLIGHTLY ABOVE NORMAL FOR MID
TO LATE JANUARY.
TO BEGIN 00Z THURSDAY NW FLOW OVER THE W HALF AND 850MB TEMPS NEAR -
12C...WITH SOME MOISTURE IN THE DGZ WILL BE OPPOSED TO THE
STRENGTHENING INVERSION. EXPECT ONLY LIGHT SNOW. UPPER MI WILL BE IN
BETWEEN A WAVE SLIDING TO OUR S...AND AN ADDITIONAL WAVE STRETCHING
FROM THE 500MB TROUGH AND ASSOCIATED SFC LOW OVER HUDSON BAY
STRETCHING ACROSS ONTARIO. WHILE COOLER AIR WILL BRIEFLY SLIDE IN
WEDNESDAY NIGHT...MOISTURE WILL BE LIMITED AS HIGH PRESSURE SLOWLY
BUILDS IN.
STRENGTHENING WINDS WILL BE THE MAIN STORY FOR THURSDAY NIGHT INTO
FRIDAY...AS UPPER MI RESIDES BETWEEN THE STRONG LOW SETTLING ACROSS
THE OHIO VALLEY AND A ORGANIZED LOW ACROSS N MANITOBA AT 00Z FRIDAY.
EXPECT THE LOW TO SHIFT TO CROSS N AND CENTRAL ONTARIO FRIDAY...AND
EXIT ACROSS JAMES BAY FRIDAY EVENING. HIGHS IN THE LOW TO MID 30S
/AROUND 10F ABOVE NORMAL/ LOOK REASONABLE FOR FRIDAY AFTERNOON AS
850MB TEMPS RISE TO 0 TO 3C...ALONG WITH A CHANCE OF SNOW AND PATCHY
BLOWING SNOW ALONG LAKE SUPERIOR. THE MAIN SFC TROUGH WILL USHER
COOLER AIR BACK INTO THE CWA SATURDAY...WITH SLOWLY FALLING TEMPS
THROUGH THE DAY. DECREASED WINDS SLIGHTLY FROM WHAT WE HAD
ORIGINALLY FRIDAY NIGHT/SATURDAY...WHICH WILL NEED TO BE MONITORED.
THURSDAY NIGHT/FRIDAY MORNING STILL LOOKS TO BE THE PERIOD OF
STRONGEST WINDS. THE 20/12Z ECMWF HAS COME IN WITH 40-50KT W WINDS
AT 850MB 06-12Z FRIDAY.
LOOKING FARTHER OUT...THERE ARE SOME SIGNIFICANT DISCREPANCIES AS WE
MOVE INTO THE LONGER RANGE OF THIS FCST...FROM MONDAY AFTERNOON ON.
ONE CHANGE FOR THIS ISSUANCE WAS TO LIMIT THE TIME OF N-NE WINDS
ACROSS LAKE SUPERIOR...BRINING LIGHT TO MODERATE LES INTO N CENTRAL
UPPER MI. THE 02/12Z ECMWF STILL HOLDS ONTO THE EXTENDED DURATION OF
COOL N-NE WINDS...WITH 850MB TEMPS AROUND -15C. THE GFS SWEEPS A LOW
ACROSS THE AREA...WITH VARIED WIND DIRECTIONS. WILL CONTINUE A BLEND
AT THIS TIME...AND WAIT FOR FCST MODELS TO HAVE A BETTER HANDLE ON
THIS LATER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE JAN 20 2015
EXPECT PREDOMINANT MVFR CONDITIONS THROUGH TAF PERIOD AT MOST OF THE
SITES AS LOW-LVL MOISTURE REMAINS TRAPPED UNDER PERSISTENT
SUBSIDENCE INVERSION. DRIER EASTERLY WIND AT KSAW COULD ALLOW FOR LOW
CLOUDS TO SCATTER OUT THROUGH THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST TUE JAN 20 2015
A RELATIVELY TRANQUIL PERIOD IS EXPECTED INTO THURSDAY WITH WINDS
BELOW 30 KNOTS. HOWEVER...SW WINDS WILL INCREASE TO 30 KNOTS THU
NIGHT WITH A FEW GALE FORCE GUSTS POSSIBLE AS LOW PRESSURE MOVES
TOWARD JAMES BAY. WEST WINDS TO 30 KNOTS ARE EXPECTED TO CONTINUE
FRI INTO SAT AS WINDS VEER TO THE WEST AND THEN TO THE NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
436 PM EST TUE JAN 20 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EST TUE JAN 20 2015
WATER VAPOR LOOP AND RUC ANALYSIS INDICATES A NW FLOW OVER THE
REGION AS THE MAIN SHORTWAVE EMBEDDED IN THIS FLOW IS WELL SW OF THE
UPPER LAKES. VIS SATELLITE LOOP SHOWS LOW CLOUDS PERSISTING OVER THE
W-SW FCST AREA WITH MOSTLY SUNNY SKIES ACROSS THE NCNTRL AND ERN
FCST AREA. MESOSCALE LOW IS EVIDENT JUST EAST OF THE KEWEENAW AND
MOVING SLOWLY EAST.
TONIGHT...LATEST HIGH RES MODELS HAVING A POOR TIME RESOLVING
MESOSCALE FEATURE EAST OF THE KEWEENAW THIS EVENING. AS A
RESULT...HAD TO ADJUST POPS UP TO 50-60 PCT OVER THE TIP OF
THE KEWEENAW AT LEAST THROUGH THIS EVENING TO ACCOUNT FOR THE LES
POTENTIAL. ALSO BUMPED UP SNOW ACCUMULATION TO 1-2 INCHES OVER
THE TIP OF THE KEWEENAW THROUGH THIS EVENING BUT THIS MAY BE TOO
CONSERVATIVE GIVEN FAIRLY IMPRESSIVE LOOK TO THE MESOLOW ON VISIBLE
SATELLITE.
ELSEWHERE TONIGHT TEMPS AND CLOUDS WILL BE THE MAIN CONCERN AND
DETERMINING HOW FAR WEST THE CLEARING LINE REACHES INTO SW UPPER MI
THIS EVENING. THIS WILL HAVE A BIG IMPACT ON MIN TEMPS. AT A
MININUM...WHERE THERE IS CLEARING...SHOULD SEE TEMPS LOWERING INTO
AT LEAST THE SINGLE DIGITS BLO ZERO AND PROBABLY WILL REACH COLDER
THAN -10F AT SOME OF THE COLDER EASTERN INTERIOR LOCATIONS. WILL
KEEP TEMPS CLOSER TO 10-12F OVER THE FAR WEST WHERE CLOUDS SHOULD
PERSIST THROUGH THE NIGHT.
WEDNESDAY...WEAK SHORTWAVE MOVING DOWN FROM MANITOBA/NRN ONTARIO
WILL PUSH A SURFACE TROUGH INTO NW UPPER MI/SCNTRL LAKE SUPERIOR.
LOOK FOR THIS TROUGH TO BECOME THE FOCUS FOR SOME LIGHT LES AS 850
MB TEMPS LINGER AROUND -11C. WILL MAINTAIN SLIGHT CHC TO LOW CHC
POPS OVER NW AND NCNTRL ZONES. EXPECT TEMPS TO REBOUND FM CHILLY
OVERNIGHT LOWS AND REACH INTO THE LOWER 20S EAST TO MID TO UPPER 20S
WEST AND CENTRAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 435 PM EST TUE JAN 20 2015
A TROUGH OF LOW PRESSURE WILL REMAIN ACROSS EASTERN CANADA AND MUCH
OF THE EASTERN U.S. THROUGH THE PERIOD...WITH A RIDGE ACROSS THE FAR
W. AS A RESULT...A SERIES OF WAVES WILL DIVE S ACROSS THE UPPER
GREAT LAKES REGION. HIGH TEMPERATURES WILL GENERALLY HOVER IN THE
20S TO LOW 30S...WHICH IS NEAR TO JUST SLIGHTLY ABOVE NORMAL FOR MID
TO LATE JANUARY.
TO BEGIN 00Z THURSDAY NW FLOW OVER THE W HALF AND 850MB TEMPS NEAR -
12C...WITH SOME MOISTURE IN THE DGZ WILL BE OPPOSED TO THE
STRENGTHENING INVERSION. EXPECT ONLY LIGHT SNOW. UPPER MI WILL BE IN
BETWEEN A WAVE SLIDING TO OUR S...AND AN ADDITIONAL WAVE STRETCHING
FROM THE 500MB TROUGH AND ASSOCIATED SFC LOW OVER HUDSON BAY
STRETCHING ACROSS ONTARIO. WHILE COOLER AIR WILL BRIEFLY SLIDE IN
WEDNESDAY NIGHT...MOISTURE WILL BE LIMITED AS HIGH PRESSURE SLOWLY
BUILDS IN.
STRENGTHENING WINDS WILL BE THE MAIN STORY FOR THURSDAY NIGHT INTO
FRIDAY...AS UPPER MI RESIDES BETWEEN THE STRONG LOW SETTLING ACROSS
THE OHIO VALLEY AND A ORGANIZED LOW ACROSS N MANITOBA AT 00Z FRIDAY.
EXPECT THE LOW TO SHIFT TO CROSS N AND CENTRAL ONTARIO FRIDAY...AND
EXIT ACROSS JAMES BAY FRIDAY EVENING. HIGHS IN THE LOW TO MID 30S
/AROUND 10F ABOVE NORMAL/ LOOK REASONABLE FOR FRIDAY AFTERNOON AS
850MB TEMPS RISE TO 0 TO 3C...ALONG WITH A CHANCE OF SNOW AND PATCHY
BLOWING SNOW ALONG LAKE SUPERIOR. THE MAIN SFC TROUGH WILL USHER
COOLER AIR BACK INTO THE CWA SATURDAY...WITH SLOWLY FALLING TEMPS
THROUGH THE DAY. DECREASED WINDS SLIGHTLY FROM WHAT WE HAD
ORIGINALLY FRIDAY NIGHT/SATURDAY...WHICH WILL NEED TO BE MONITORED.
THURSDAY NIGHT/FRIDAY MORNING STILL LOOKS TO BE THE PERIOD OF
STRONGEST WINDS. THE 20/12Z ECMWF HAS COME IN WITH 40-50KT W WINDS
AT 850MB 06-12Z FRIDAY.
LOOKING FARTHER OUT...THERE ARE SOME SIGNIFICANT DISCREPANCIES AS WE
MOVE INTO THE LONGER RANGE OF THIS FCST...FROM MONDAY AFTERNOON ON.
ONE CHANGE FOR THIS ISSUANCE WAS TO LIMIT THE TIME OF N-NE WINDS
ACROSS LAKE SUPERIOR...BRINING LIGHT TO MODERATE LES INTO N CENTRAL
UPPER MI. THE 02/12Z ECMWF STILL HOLDS ONTO THE EXTENDED DURATION OF
COOL N-NE WINDS...WITH 850MB TEMPS AROUND -15C. THE GFS SWEEPS A LOW
ACROSS THE AREA...WITH VARIED WIND DIRECTIONS. WILL CONTINUE A BLEND
AT THIS TIME...AND WAIT FOR FCST MODELS TO HAVE A BETTER HANDLE ON
THIS LATER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE JAN 20 2015
EXPECT PREDOMINANT MVFR CONDITIONS THROUGH TAF PERIOD AT MOST OF THE
SITES AS LOW-LVL MOISTURE REMAINS TRAPPED UNDER PERSISTENT
SUBSIDENCE INVERSION. DRIER EASTERLY WIND AT KSAW COULD ALLOW FOR LOW
CLOUDS TO SCATTER OUT THROUGH THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST TUE JAN 20 2015
A RELATIVELY TRANQUIL PERIOD IS EXPECTED INTO THURSDAY WITH WINDS
BELOW 30 KNOTS. HOWEVER...SW WINDS WILL INCREASE TO 30 KNOTS THU
NIGHT WITH A FEW GALE FORCE GUSTS POSSIBLE AS LOW PRESSURE MOVES
TOWARD JAMES BAY. WEST WINDS TO 30 KNOTS ARE EXPECTED TO CONTINUE
FRI INTO SAT AS WINDS VEER TO THE WEST AND THEN TO THE NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 PM EST TUE JAN 20 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EST TUE JAN 20 2015
WATER VAPOR LOOP AND RUC ANALYSIS INDICATES A NW FLOW OVER THE
REGION AS THE MAIN SHORTWAVE EMBEDDED IN THIS FLOW IS WELL SW OF THE
UPPER LAKES. VIS SATELLITE LOOP SHOWS LOW CLOUDS PERSISTING OVER THE
W-SW FCST AREA WITH MOSTLY SUNNY SKIES ACROSS THE NCNTRL AND ERN
FCST AREA. MESOSCALE LOW IS EVIDENT JUST EAST OF THE KEWEENAW AND
MOVING SLOWLY EAST.
TONIGHT...LATEST HIGH RES MODELS HAVING A POOR TIME RESOLVING
MESOSCALE FEATURE EAST OF THE KEWEENAW THIS EVENING. AS A
RESULT...HAD TO ADJUST POPS UP TO 50-60 PCT OVER THE TIP OF
THE KEWEENAW AT LEAST THROUGH THIS EVENING TO ACCOUNT FOR THE LES
POTENTIAL. ALSO BUMPED UP SNOW ACCUMULATION TO 1-2 INCHES OVER
THE TIP OF THE KEWEENAW THROUGH THIS EVENING BUT THIS MAY BE TOO
CONSERVATIVE GIVEN FAIRLY IMPRESSIVE LOOK TO THE MESOLOW ON VISIBLE
SATELLITE.
ELSEWHERE TONIGHT TEMPS AND CLOUDS WILL BE THE MAIN CONCERN AND
DETERMINING HOW FAR WEST THE CLEARING LINE REACHES INTO SW UPPER MI
THIS EVENING. THIS WILL HAVE A BIG IMPACT ON MIN TEMPS. AT A
MININUM...WHERE THERE IS CLEARING...SHOULD SEE TEMPS LOWERING INTO
AT LEAST THE SINGLE DIGITS BLO ZERO AND PROBABLY WILL REACH COLDER
THAN -10F AT SOME OF THE COLDER EASTERN INTERIOR LOCATIONS. WILL
KEEP TEMPS CLOSER TO 10-12F OVER THE FAR WEST WHERE CLOUDS SHOULD
PERSIST THROUGH THE NIGHT.
WEDNESDAY...WEAK SHORTWAVE MOVING DOWN FROM MANITOBA/NRN ONTARIO
WILL PUSH A SURFACE TROUGH INTO NW UPPER MI/SCNTRL LAKE SUPERIOR.
LOOK FOR THIS TROUGH TO BECOME THE FOCUS FOR SOME LIGHT LES AS 850
MB TEMPS LINGER AROUND -11C. WILL MAINTAIN SLIGHT CHC TO LOW CHC
POPS OVER NW AND NCNTRL ZONES. EXPECT TEMPS TO REBOUND FM CHILLY
OVERNIGHT LOWS AND REACH INTO THE LOWER 20S EAST TO MID TO UPPER 20S
WEST AND CENTRAL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 AM EST TUE JAN 20 2015
A BUILDING RIDGE OVER THE PACIFIC NORTHWEST AND WESTERN CANADA
TODAY WILL LEAD TO NORTHWESTERLY FLOW ALOFT AND SEND A SERIES OF
SHORTWAVES/CLIPPERS SOUTHEAST ACROSS THE GREAT LAKES AND EASTERN
CANADA. ALTHOUGH THESE CLIPPERS WILL BE BRINGING CANADIAN AIR ACROSS
THE REGION...THE COLDEST AIR WILL REMAIN LOCKED OVER HUDSON BAY.
THUS...EXPECT TEMPERATURES TO BE NEAR OR ABOVE NORMAL OVER THE
NEXT WEEK WITH OCCASIONAL PERIODS OF LIGHT SNOW OR FLURRIES WITH THE
CLIPPERS. BETWEEN THE CLIPPERS THERE MAY BE A FEW PERIODS OF VERY
LIGHT LAKE EFFECT SNOW...BUT 925/850MB TEMPS ARE FAIRLY MARGINAL AND
THE WIND FIELDS ARE CONSTANTLY FLUCTUATING TO SUPPORT MUCH MORE THAN
OCCASIONAL SHOWERS. ALL IN ALL...NOT MUCH IN THE WAY OF SIGNIFICANT
WEATHER FOR THE PERIOD.
THE AREA WILL BE BETWEEN SHORTWAVES ON WEDNESDAY (ONE WILL BE
TRACKING THROUGH SOUTHERN WISCONSIN AND ILLINOIS AND THE OTHER
THROUGH NORTHERN ONTARIO)...WHICH WILL LIMIT ANY LARGER SCALE
SUPPORT FOR PRECIPITATION. BUT A LOW LEVEL THERMAL TROUGH WILL
GRADUALLY DROP SOUTHEAST ACROSS THE CWA LATE TONIGHT THROUGH
WEDNESDAY NIGHT...LEADING TO WINDS GRADUALLY BECOMING NORTHWEST ON
WEDNESDAY BEFORE QUICKLY BACKING SOUTHWESTERLY THURSDAY AHEAD OF A
SLIGHTLY STRONGER SHORTWAVE AND CLIPPER THAT WILL MOVE THROUGH
NORTHERN ONTARIO ON FRIDAY. MODELS ARE STILL VARYING ON THE AMOUNT
OF COLD AIR...BUT THERE SHOULD BE ENOUGH TO PRODUCE SOME LIGHT
SNOW...ESPECIALLY OVER THE WEST AND KEWEENAW WHERE LIGHT
NORTHWESTERLY WINDS ARE EXPECTED. FARTHER EAST...IT MAY TAKE A
LITTLE LONGER TO GET THE SNOW TO DEVELOP (DUE TO THE DELAYED
ARRIVAL OF COLDER AIR) BUT SHOULD SEE SOME LIGHT SNOW LATE
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. THERE ARE TWO FACTORS
CONTRIBUTING TO LIMITED SNOWFALL AMOUNTS...THE MARGINAL DELTA-T
VALUES (WEAK LAPSE RATES) AND MUCH OF THE CLOUD BELOW THE DGZ. THE
KEWEENAW WOULD SEE THE BEST CHANCE FOR AN INCH OF SNOW DUE TO THE
HIGHER INVERSION HEIGHTS (5-7KFT)...ALTHOUGH THE WEAK LAPSE RATES
WILL LIMIT INTENSITY. EXPECT THE LAKE EFFECT PRECIPITATION TO FOCUS
OVER THE WEST-SOUTHWEST WIND AREAS ON THURSDAY...BEFORE DIMINISHING
AS WARM AIR ADVECTION INCREASES AND STRENGTHENS THE INVERSION BELOW
850MB. DEPENDING ON THE AMOUNT OF MIXING ON THURSDAY...IT COULD GET
A LITTLE GUSTY WITH GUSTS UP TO 20-25KTS.
THAT NEXT CLIPPER WILL MOVE MOVING ACROSS NORTHERN ONTARIO LATE
THURSDAY NIGHT AND FRIDAY...WHICH WILL SWEEP A COLD FRONT SOUTHEAST
ACROSS THE CWA FRIDAY AFTERNOON INTO FRIDAY EVENING. WILL SHOWING
INCREASING PRECIPITATION CHANCES AHEAD OF THE FRONT AS IT MOVES
ACROSS THE AREA. THERE IS SOME SUPPORT ALOFT...AS A SECONDARY
SHORTWAVE WILL DROP ACROSS THE AREA WITH THE FRONT...BUT THERE IS A
DECENT POCKET OF DRY AIR BETWEEN 925-750MB OVER THE SOUTHERN HALF
OF THE U.P. WHICH WILL LIKELY LIMIT PRECIPITATION CHANCES THERE.
ALSO...THAT AREA WITH THE DRY AIR AND WARMING WOULD PUT THE THERMAL
PROFILE THERE ABOVE FREEZING. BUT LOOKING AT THE WETBULB VALUES
WOULD INDICATE IF PRECIPITATION WOULD OCCUR...IT WOULD COOL BACK
BELOW FREEZING. THEREFORE AT THIS POINT...WILL KEEP PRECIPITATION
AS ALL SNOW AND ONLY HAVE AMOUNTS UNDER AN INCH FOR MOST AREAS
(AND A COUPLE INCHES OVER THE EAST).
FORECAST BECOMES A LITTLE UNCERTAIN FOR FRIDAY NIGHT INTO SATURDAY
BEHIND THE CLIPPER. WHILE ALL OF THE MODELS SHIFT THE WINDS TO THE
NORTHWEST BEHIND THE FRONT...THERE IS A SIGNIFICANT DIFFERENCE IN
850MB TEMPS. THE 00Z GFS AND PAST COUPLE OF RUNS HAVE BEEN
CONSISTENT IN DROPPING 850MB TEMPS TO -12C...WHILE RECENT RUNS OF
THE ECMWF/GEM ARE MUCH WARMER AND AROUND -6C THROUGH SATURDAY
NIGHT. THAT COLD AIR MAKES/BREAKS THE LAKE EFFECT POTENTIAL FOR
THIS WEEKEND IN THE NW WIND SNOW BELTS. WITH THE 12Z ECMWF ENSEMBLE
MEAN CLOSER TO THE ECMWF/GEM DETERMINISTIC RUNS...WILL TREND IN
THAT DIRECTION BUT STILL KEEP LOW CHANCE AND SLIGHT CHANCE POPS IN
THE FAVORED NW WIND AREAS. HIGH PRESSURE SLIGHTS THROUGH NORTHERN
ONTARIO ON SUNDAY...WHICH WILL SHIFT WINDS TO THE NORTHEAST AND
EVENTUALLY EASTERLY. SNOW STILL DEPENDS ON HOW COLD IT WILL
BE...BUT BOTH GEM/ECMWF DO SHOW 850MB TEMPS FALLING TOWARDS -12C ON
SUNDAY AND WILL SHOW CHANCE POPS IN THE NORTH CENTRAL AND KEWEENAW.
ANOTHER CLIPPER SYSTEM WILL APPROACH THE AREA ON MONDAY FROM THE
NORTHWEST AND WILL SHOW SLIGHT CHANCE POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE JAN 20 2015
EXPECT PREDOMINANT MVFR CONDITIONS THROUGH TAF PERIOD AT MOST OF THE
SITES AS LOW-LVL MOISTURE REMAINS TRAPPED UNDER PERSISTENT
SUBSIDENCE INVERSION. DRIER EASTERLY WIND AT KSAW COULD ALLOW FOR LOW
CLOUDS TO SCATTER OUT THROUGH THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST TUE JAN 20 2015
A RELATIVELY TRANQUIL PERIOD IS EXPECTED INTO THURSDAY WITH WINDS
BELOW 30 KNOTS. HOWEVER...SW WINDS WILL INCREASE TO 30 KNOTS THU
NIGHT WITH A FEW GALE FORCE GUSTS POSSIBLE AS LOW PRESSURE MOVES
TOWARD JAMES BAY. WEST WINDS TO 30 KNOTS ARE EXPECTED TO CONTINUE
FRI INTO SAT AS WINDS VEER TO THE WEST AND THEN TO THE NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1255 PM EST TUE JAN 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST TUE JAN 20 2015
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW INTO
THE NRN GREAT LAKES BETWEEN A TROUGH FROM QUEBEC INTO THE NE CONUS
AND A RIDGE OVER WRN CANADA. QVECTOR DIV/SUBSIDENCE PREVAILED OVER
THE REGION IN THE WAKE OF A SHORTWAVE TROUGH MOVING INTO LOWER
MI. AT THE SFC...LIGHT VARIABLE WINDS CONTINUED OVER LAKE SUPERIOR
AND UPPER MICHIGAN ON THE SRN FLANK OF HIGH PRES OVER NRN ONTARIO.
RADAR SHOWED LES DIMINISHING OVER N CNTRL UPPER MI WITH MAINLY JUST
FLURRIES. THERE WAS ENOUGH OF A NRLY WIND COMPONENT ABOVE THE SFC TO
SUSTAIN THE LES/FLURRIES WELL INLAND. HOWEVER...AS THE WINDS
CONTINUED TO WEAKEN...THE SNOW WAS ALSO DISSIPATING.WITH 900 MB
TEMPS AROUND -12C...CONDITIONS REMAINED FAVORABLE FOR HIGHER SLR
VALUES ABOVE 30/1. OTHERWISE...CLOUDS OVER WEST/CNTRL UPPER MI HAS
KEPT TEMPS IN THE TEENS WHILE CLEARING OVER THE EAST HAS ALLOWED
TEMPS TO DROP TO 0 TO -10F.
TODAY...THE LINGERING LOW LEVEL MOISTURE AND COLD AIR WILL SUSTAIN
THE LIGHT LES. HOWEVER...CONFIDENCE IN WHERE ANY BANDS WILL DEVELOP
OR MOVE WITH THE LIGHT WINDS IS LOW. SO...ONLY CHANCE POPS WERE
MENTIONED FOR LOCATIONS FAVORED BY EAST FLOW...FROM NRN MARQUETTE
COUNTY INTO THE KEWEENAW. THE DRY EASTERLY FLOW SHOULD BRING MOSTLY
SUNNY SKIES TO THE EAST AND MAY ERODE SOME OF THE LOWER CLOUDS OVER
CENTRAL UPPER MICHIGAN. TEMPS WILL CLIMB TO AROUND SEASONAL
AVERAGES WITH HIGHS FROM THE UPPER TEENS EAST TO THE MID 20S WEST.
TONIGHT...THE HIGHER RES MODELS SUGGEST THAT MOST OF THE LINGERING
LES WILL REMAIN OFFSHORE BUT MAY MOVE BACK INTO THE KEWEENAW AS
WINDS BECOME LIGHT NORTHERLY. EXPECT THE LOWEST TEMPS OVER THE EAST
TO AROUND ZERO WHERE SKIES REMAIN MOSTLY CLEAR. THERE IS MORE
UNCERTAINTY WITH THE CLOUDS/TEMPS CENTRAL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 AM EST TUE JAN 20 2015
A BUILDING RIDGE OVER THE PACIFIC NORTHWEST AND WESTERN CANADA
TODAY WILL LEAD TO NORTHWESTERLY FLOW ALOFT AND SEND A SERIES OF
SHORTWAVES/CLIPPERS SOUTHEAST ACROSS THE GREAT LAKES AND EASTERN
CANADA. ALTHOUGH THESE CLIPPERS WILL BE BRINGING CANADIAN AIR ACROSS
THE REGION...THE COLDEST AIR WILL REMAIN LOCKED OVER HUDSON BAY.
THUS...EXPECT TEMPERATURES TO BE NEAR OR ABOVE NORMAL OVER THE
NEXT WEEK WITH OCCASIONAL PERIODS OF LIGHT SNOW OR FLURRIES WITH THE
CLIPPERS. BETWEEN THE CLIPPERS THERE MAY BE A FEW PERIODS OF VERY
LIGHT LAKE EFFECT SNOW...BUT 925/850MB TEMPS ARE FAIRLY MARGINAL AND
THE WIND FIELDS ARE CONSTANTLY FLUCTUATING TO SUPPORT MUCH MORE THAN
OCCASIONAL SHOWERS. ALL IN ALL...NOT MUCH IN THE WAY OF SIGNIFICANT
WEATHER FOR THE PERIOD.
THE AREA WILL BE BETWEEN SHORTWAVES ON WEDNESDAY (ONE WILL BE
TRACKING THROUGH SOUTHERN WISCONSIN AND ILLINOIS AND THE OTHER
THROUGH NORTHERN ONTARIO)...WHICH WILL LIMIT ANY LARGER SCALE
SUPPORT FOR PRECIPITATION. BUT A LOW LEVEL THERMAL TROUGH WILL
GRADUALLY DROP SOUTHEAST ACROSS THE CWA LATE TONIGHT THROUGH
WEDNESDAY NIGHT...LEADING TO WINDS GRADUALLY BECOMING NORTHWEST ON
WEDNESDAY BEFORE QUICKLY BACKING SOUTHWESTERLY THURSDAY AHEAD OF A
SLIGHTLY STRONGER SHORTWAVE AND CLIPPER THAT WILL MOVE THROUGH
NORTHERN ONTARIO ON FRIDAY. MODELS ARE STILL VARYING ON THE AMOUNT
OF COLD AIR...BUT THERE SHOULD BE ENOUGH TO PRODUCE SOME LIGHT
SNOW...ESPECIALLY OVER THE WEST AND KEWEENAW WHERE LIGHT
NORTHWESTERLY WINDS ARE EXPECTED. FARTHER EAST...IT MAY TAKE A
LITTLE LONGER TO GET THE SNOW TO DEVELOP (DUE TO THE DELAYED
ARRIVAL OF COLDER AIR) BUT SHOULD SEE SOME LIGHT SNOW LATE
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. THERE ARE TWO FACTORS
CONTRIBUTING TO LIMITED SNOWFALL AMOUNTS...THE MARGINAL DELTA-T
VALUES (WEAK LAPSE RATES) AND MUCH OF THE CLOUD BELOW THE DGZ. THE
KEWEENAW WOULD SEE THE BEST CHANCE FOR AN INCH OF SNOW DUE TO THE
HIGHER INVERSION HEIGHTS (5-7KFT)...ALTHOUGH THE WEAK LAPSE RATES
WILL LIMIT INTENSITY. EXPECT THE LAKE EFFECT PRECIPITATION TO FOCUS
OVER THE WEST-SOUTHWEST WIND AREAS ON THURSDAY...BEFORE DIMINISHING
AS WARM AIR ADVECTION INCREASES AND STRENGTHENS THE INVERSION BELOW
850MB. DEPENDING ON THE AMOUNT OF MIXING ON THURSDAY...IT COULD GET
A LITTLE GUSTY WITH GUSTS UP TO 20-25KTS.
THAT NEXT CLIPPER WILL MOVE MOVING ACROSS NORTHERN ONTARIO LATE
THURSDAY NIGHT AND FRIDAY...WHICH WILL SWEEP A COLD FRONT SOUTHEAST
ACROSS THE CWA FRIDAY AFTERNOON INTO FRIDAY EVENING. WILL SHOWING
INCREASING PRECIPITATION CHANCES AHEAD OF THE FRONT AS IT MOVES
ACROSS THE AREA. THERE IS SOME SUPPORT ALOFT...AS A SECONDARY
SHORTWAVE WILL DROP ACROSS THE AREA WITH THE FRONT...BUT THERE IS A
DECENT POCKET OF DRY AIR BETWEEN 925-750MB OVER THE SOUTHERN HALF
OF THE U.P. WHICH WILL LIKELY LIMIT PRECIPITATION CHANCES THERE.
ALSO...THAT AREA WITH THE DRY AIR AND WARMING WOULD PUT THE THERMAL
PROFILE THERE ABOVE FREEZING. BUT LOOKING AT THE WETBULB VALUES
WOULD INDICATE IF PRECIPITATION WOULD OCCUR...IT WOULD COOL BACK
BELOW FREEZING. THEREFORE AT THIS POINT...WILL KEEP PRECIPITATION
AS ALL SNOW AND ONLY HAVE AMOUNTS UNDER AN INCH FOR MOST AREAS
(AND A COUPLE INCHES OVER THE EAST).
FORECAST BECOMES A LITTLE UNCERTAIN FOR FRIDAY NIGHT INTO SATURDAY
BEHIND THE CLIPPER. WHILE ALL OF THE MODELS SHIFT THE WINDS TO THE
NORTHWEST BEHIND THE FRONT...THERE IS A SIGNIFICANT DIFFERENCE IN
850MB TEMPS. THE 00Z GFS AND PAST COUPLE OF RUNS HAVE BEEN
CONSISTENT IN DROPPING 850MB TEMPS TO -12C...WHILE RECENT RUNS OF
THE ECMWF/GEM ARE MUCH WARMER AND AROUND -6C THROUGH SATURDAY
NIGHT. THAT COLD AIR MAKES/BREAKS THE LAKE EFFECT POTENTIAL FOR
THIS WEEKEND IN THE NW WIND SNOW BELTS. WITH THE 12Z ECMWF ENSEMBLE
MEAN CLOSER TO THE ECMWF/GEM DETERMINISTIC RUNS...WILL TREND IN
THAT DIRECTION BUT STILL KEEP LOW CHANCE AND SLIGHT CHANCE POPS IN
THE FAVORED NW WIND AREAS. HIGH PRESSURE SLIGHTS THROUGH NORTHERN
ONTARIO ON SUNDAY...WHICH WILL SHIFT WINDS TO THE NORTHEAST AND
EVENTUALLY EASTERLY. SNOW STILL DEPENDS ON HOW COLD IT WILL
BE...BUT BOTH GEM/ECMWF DO SHOW 850MB TEMPS FALLING TOWARDS -12C ON
SUNDAY AND WILL SHOW CHANCE POPS IN THE NORTH CENTRAL AND KEWEENAW.
ANOTHER CLIPPER SYSTEM WILL APPROACH THE AREA ON MONDAY FROM THE
NORTHWEST AND WILL SHOW SLIGHT CHANCE POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE JAN 20 2015
EXPECT PREDOMINANT MVFR CONDITIONS THROUGH TAF PERIOD AT MOST OF THE
SITES AS LOW-LVL MOISTURE REMAINS TRAPPED UNDER PERSISTENT
SUBSIDENCE INVERSION. DRIER EASTERLY WIND AT KSAW COULD ALLOW FOR LOW
CLOUDS TO SCATTER OUT THROUGH THIS EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 517 AM EST TUE JAN 20 2015
A RELATIVELY TRANQUIL PERIOD IS EXPECTED INTO THURSDAY WITH WINDS
BELOW 30 KNOTS. HOWEVER...SW WINDS WILL INCREASE TO 30 KNOTS THU
NIGHT WITH A FEW GALE FORCE GUSTS POSSIBLE AS LOW PRESSURE MOVES
TOWARD JAMES BAY. WEST WINDS TO 30 KNOTS ARE EXPECTED TO CONTINUE
FRI INTO SAT AS WINDS VEER TO THE WEST AND THEN TO THE NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
104 PM EST TUE JAN 20 2015
.SYNOPSIS...
PASSING UPPER LEVEL DISTURBANCES...AND MOISTURE...WILL LEAD TO
LINGERING FLURRIES INTO THIS AFTERNOON. LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED. TONIGHT AND MOST OF WEDNESDAY WILL BE
DRY AND SEASONABLY COLD...WITH WEAK HIGH PRESSURE IN CONTROL. A
FAST MOVING STORM SYSTEM WILL BRING A PERIOD OF LIGHT SNOW OR
FLURRIES WEDNESDAY NIGHT INTO EARLY THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
940 AM UPDATE...VISIBLE SATELLITE SHOWS SHALLOW LOW-LEVEL MOISTURE
AND STRATOCUMULUS CLOUDS THAT LINGERED OVER MUCH OF CENTRAL NY
AND MOST OF PA. A DRIER ARCTIC AIR MASS HAS SLIDE SOUTHWARD INTO
ONEIDA COUNTY AND HAS LED TO CLEARING. MODEL SOUNDINGS CONTINUE
TO SHOW MOISTURE TRAPPED UNDER AN INVERSION MOST AREAS WHICH
LOWERS DURING THE AFTERNOON. THE HRRR SUGGESTS CLEARING IN MOST
AREAS WITH THE NAM12 CONTINUING THE LOW CLDS ESP ACRS NE PA TO THE
CATSKILLS. LOOKING AT THE SATELLITE IMAGERY WILL HAVE PARTIAL
CLEARING WORKING S AND W DURING THE AFTERNOON. WILL KEEP MO CLDY
FROM KAVP TO KELM THRU AFTERNOON. FARTHER N AND E...THERE SHUD BE
SOME BREAKS AND NC NY WILL SEE MORE SUNSHINE. SINCE LOW-LEVEL
TEMPERATURES UNDER THE INVERSION WERE CLOSE TO THE MAX GROWTH FOR
ICE CRYSTALS IT IS NOT HARD FOR CLOUD COVER TO PRODUCE A FEW
FLURRIES AS THE AIR BLOWS UP THE HILLS. SO WILL KEEP SCT FLURRIES
UNTIL AFTERNOON.
340 AM UPDATE... LINGERING LOW-LVL MOISTURE UNDERNEATH AN 850-800
MB CAPPING INVERSION THIS MRNG...280-290 FLOW...AND FAST MOVG MID-
LVL S/WVS...WILL KEEP FLRYS/SCTD LGT SNOW SHWRS GOING THROUGH AT
LEAST 12-15Z...UNDERNEATH MAINLY CLOUDY SKIES.
STARTING DURG THE LATE MRNG AND EARLY AFTN HRS...SOME LOW-LVL
DRYING DOES ATTEMPT TO COME DOWN FROM THE N...WITH WEAK SFC
RIDGING BLDG DOWN FROM ONT/QUE. THUS...WE MAY SEE BREAKS OF
SUNSHINE DVLP BY AFTN...ALG WITH A CESSATION OF FLRYS/SNOW SHWRS.
IT WILL BE SEASONABLY COLD AGN TDY...WITH MAX TEMPS MOSTLY IN THE
20S...EXCEPT FOR A FEW LWR 30S IN THE WYO/LACK VLYS OF NE PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
350 AM UPDATE... TNT AND MOST OF WED WILL BE QUIET/DRY...WITH ABV
MENTIONED SFC HIGH PRES BLDG ACRS UPSTATE NY AND NRN NEW ENG.
CLEAR TO PTLY CLDY SKIES...SPCLY OVER OUR NRN ZNS TNT...ALG WITH A
CHILLY AMS AND SNOW COVER...WILL LEAD TO LOW TEMPS IN THE SINGLE
DIGITS OVER MUCH OF CNY/NE PA. SOME OF OUR NORMALLY COLDER VLYS
COULD SEE SUB-ZERO READINGS BY DAYBREAK WED. BY WED AFTN...HIGHS
SHOULD RECOVER INTO THE 20S-LWR 30S ONCE AGN...UNDERNEATH
INCREASING MID TO HIGH-LVL CLDNS.
WED NGT INTO EARLY THU...WE CONTINUE TO WATCH A S/WV EMERGING FROM
THE NRN PLAINS/UPR LKS RGNS...THEN COMING EWD ACRS NY/PA. AN
ASSOCD WEAK CLIPPER-TYPE SFC LOW IS PROGGED TO TRACK EWD IN
TANDEM...LIKELY ACRS THE OH VLY/PA/NJ. A NARROW SWATH OF LGT SNOW
IS EXPECTED TO ACCOMPANY THIS SYSTEM. HOWEVER...THE EXACT LATITUDE
OF THIS STRIPE OF LGT SNOW REMAINS IN QUESTION (THE NAM FARTHEST N
THROUGH MUCH OF CNY...WHILE THE EC IS FARTHEST S...MOSTLY POINTS
FROM PA SWD). FOR NOW...WE`VE GONE WITH A BLEND OF OUR EXISTING FCST
AND A MODEL COMPROMISE...WHICH WOULD BRING A GENERAL 0.5-1.5" OF
SNOW TO MOST OF THE FA OVERNIGHT WED INTO THU MRNG. LGT SNOW
SHOULD TAPER OFF TO SCTD SNOW SHWRS/FLRYS THU AFTN...AS THE MAIN
FORCED ASCENT SHIFTS EWD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
PD FEATURES CONTD BLO NRML TEMPS...AND A NEAR MISS BY A CPL DVLPG
CSTL SYSTEMS. DETAILS...FRI NGT BEGINS THE PD WITH DRY AIR OUT AHD
OF SAT/S DVLPG CSTL SYSTEM. BOTH THE EURO AND GFS AGREE TO KEEP
THE CNTR OF THE DEEPENING STORM WELL EAST OF THE NJ CST DURING SAT
PERHAPS JUST BRUSHING THE NEPA ZONES WITH SOME LGT SNOW OTRW
HAVING LTL EFFECT IN THE AREA. ARCTIC FNT DROPS IN BHD THE STORM
SAT NGT AND SUNDAY BRINGING SOME VERY CHILLY AIR ONCE AGAIN...WITH
A N TO NE FLOW LIMITING THE LE...AND MAXIMIZING THE CAA. BEST
CHANCE FOR LE SUNDAY WILL ONCE AGAIN BE OVER THE FINGER LAKES
REGION. ARCTIC HI BLDS IN FOR MON...BRINGING PSBL BLO ZERO TEMPS
ONCE AGAIN...ESP FOR THE NE ZONES. MODELS...ESP THE EURO...DVLP
ANOTHER DEEP CSTL ON TUE...BUT ONCE AGAIN TRACK THE CNTR WELL EAST
OF THE FCST AREA RESULTING IN LTL EFFECT IN THE FCST.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
WEAK CLIPPER WILL PASS SOUTH OF THE AREA TNGT MISSING THE TAF
SITES. HWVR...STILL SOME LL MOISTURE...PERHAPS ENHANCED BY THE
LAKES...OVER THE AREA...ESP LTR TNGT WHICH SHD BRING SOME OCNL
MVFR CIGS TO SOME OF THE NY STATIONS. NEXT SW APRCHS FOR LTR
WED...AHD OF THE SYSTEMS EARLY WED WILL FEATURE HI CIGS AND NO
RESTRICTIONS. WEAK LL GRADIENT WILL RESULT IN LGT WINDS THRU THE
TAF PD.
OUTLOOK...
WED NGT THU...MVFR PSBL IFR IN SNOW SHWRS AS CLIPPER MVES THRU.
FRI/SAT...VFR.
SUN...MVFR AND OCNL IFR PSBL IN SNOW SHWRS...ESP IN NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/MLJ
NEAR TERM...DJN/MLJ
SHORT TERM...MLJ
LONG TERM...DGM
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
425 PM EST TUE JAN 20 2015
.SYNOPSIS...
A SERIES OF WEATHER DISTURBANCES WILL MOVE EAST ACROSS THE OHIO
VALLEY THROUGH WEDNESDAY NIGHT...BRINGING OCCASIONAL CHANCES FOR
LIGHT RAIN AND SNOW. SLIGHTLY COOLER AIR WILL MOVE INTO THE REGION
THROUGH THE REST OF THE WEEK...WITH HIGH PRESSURE PROVIDING DRY
CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
WITH ONE SHORTWAVE NOW OFF TO THE EAST...THE ILN FORECAST AREA IS
NOW LOCATED UNDER A SMALL AREA OF RIDGING ALOFT. THE TEMPERATURE
GRADIENT REMAINS VERY TIGHT...DUE TO SEVERAL FACTORS. THE CLOUDS
AND SNOW PACK IN THE NORTH ARE HELPING TO KEEP CONDITIONS
COOLER...WHILE VERY CLEAR SKIES IN THE SOUTH HAVE ALLOWED FOR A
BIG DIURNAL INCREASE IN TEMPERATURES. THERE ALSO REMAINS A WEAK
AND NEBULOUS SURFACE BOUNDARY...STRETCHED SOMEWHERE ACROSS THE
REGION.
THIS TEMPERATURE GRADIENT SHOULD RELAX SLIGHTLY OVERNIGHT...AS
ATTENTION TURNS TO THE NEXT SHORTWAVE MOVING IN FROM THE WEST
(WHICH WILL BE DISCUSSED IN THE SHORT TERM SECTION). EVEN THOUGH
CLOUD COVER WILL BE INCREASING...TEMPERATURES ARE EXPECTED TO DROP
TO NEAR FREEZING (WITH MID 30S IN THE FAR SOUTH). WITH DEWPOINTS
CURRENTLY IN THE LOWER TO MID 30S AND AT LEAST SOME IMPACT
EXPECTED FROM THE INCOMING CLOUDS...MIN TEMPS WERE RAISED SLIGHTLY
FROM THE PREVIOUS FORECAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
THE FIRST PERIOD OF THE SHORT TERM FORECAST WILL COME WITH A FEW
ITEMS WORTH DISCUSSING. ANOTHER SHORTWAVE IN THE QUICK WESTERLY
FLOW WILL APPROACH THE OHIO VALLEY VERY EARLY WEDNESDAY MORNING.
AS THIS OCCURS...THE LEFT EXIT REGION OF A 100-PLUS KNOT UPPER JET
WILL BE POSITIONING ITSELF FAVORABLY...AS ISENTROPIC LIFT ALSO
DEVELOPS NEAR 700MB. COMBINED TOGETHER...THE ILN FORECAST AREA
WILL BE IN AN AREA OF DEVELOPMENTAL PRECIPITATION...WHICH IS
FORECAST TO EXPAND AND STRENGTHEN AS IT MOVES EAST-NORTHEAST
THROUGH OHIO AND INTO PENNSYLVANIA. POPS WERE RAISED TO LIKELY IN
THE NORTHERN AND NORTHEASTERN SECTIONS OF THE FORECAST AREA...WITH
SOME TIMING ADJUSTMENTS BASED ON THE 12Z NAM AND LATEST RAP MODEL
RUNS.
BEHIND THE AXIS OF THE SHORTWAVE...TEMPERATURES JUST OFF THE
SURFACE WILL BEGIN COOLING...AS WINDS SHIFT FROM SOUTHERLY TO
WESTERLY. THERE IS LITTLE REFLECTION OF THIS AT THE
SURFACE...AS THE PRESSURE PATTERN WILL REMAIN VERY
NEBULOUS...THOUGH THE LIGHT WINDS MAY SHIFT SLIGHTLY TO THE WEST.
BY LATE MORNING...LAPSE RATES WILL BE FAIRLY STEEP...AND WHETHER
PRECIPITATION FALLS AS RAIN OR SNOW WILL LARGELY BE ABLE TO BE
DEFINED BY SURFACE TEMPERATURE. THE TEMPERATURE GRADIENT WILL
REMAIN SHARP...SO A MIX OF PRECIPITATION TYPES IS LIKELY AS
CONDITIONS WARM AND COOL.
HOWEVER...JUST AHEAD OF THE SHORTWAVE...A SMALL WARM AND SATURATED
LAYER WILL REMAIN IN PLACE NEAR 925MB. PRECIPITATION COMING OUT OF
THIS LAYER WILL LIKELY BE LIQUID...NECESSITATING A CAREFUL LOOK AT
SURFACE TEMPERATURES FOR WEDNESDAY MORNING. BASED ON THE
ADJUSTMENTS DESCRIBED IN THE NEAR TERM DISCUSSION...ONLY A SMALL
SECTION OF THE FORECAST AREA APPEARS LIKELY TO FALL INTO THE
30-32 DEGREE RANGE...GENERALLY IN WEST CENTRAL AND CENTRAL OHIO.
IN FACT...SOME MODELS ALLOW THESE LOCATIONS TO REMAIN AT OR ABOVE
THE FREEZING MARK. HOWEVER...THERE IS ENOUGH UNCERTAINTY IN THE
TEMPERATURE FORECAST TO ALLOW FOR A CHANCE OF FREEZING
RAIN...ESPECIALLY AS THE PRECIPITATION IS IN THE FIRST FEW HOURS
OF ITS DEVELOPMENT. COMING OUT OF A FEW RELATIVELY WARM
DAYS...ANTECEDENT CONDITIONS FOR ICING ARE NOT FAVORABLE...AND
HAZARDOUS CONDITIONS ARE UNLIKELY. HOWEVER...IF SURFACE
TEMPERATURES AND DEWPOINTS FALL OFF MORE THAN FORECAST DURING THE
OVERNIGHT HOURS...THIS LINE OF THINKING WILL NEED TO BE REVISITED.
FOR THE GRIDS...ANY MENTION OF FREEZING RAIN WAS LIMITED TO JUST A
CHANCE...AND ICE ACCUMULATION GRIDS WERE KEPT BLANK. SNOW
ACCUMULATIONS OF A FEW TENTHS OF AN INCH WILL BE POSSIBLE IN THE
FAR NORTHERN TIER OF ILN COUNTIES...ROUGHLY ALONG AND NORTH OF A
LINE FROM WAPAKONETA TO NEWARK.
A MIX OF RAIN AND SNOW MAY CONTINUE INTO THE DAY FOR THE NORTHERN
HALF OF THE FORECAST AREA...AT LEAST AFTER A BRIEF LULL FOLLOWING
THE CURVED BAND AHEAD OF THE SHORTWAVE. ALL OF THE MODELS SUGGEST
A SECOND WAVE MOVING INTO THE AREA AFTER 18Z (JUST SOUTH OF THE
WEAKENING 700MB LOW)...WITH GENERALLY LIGHT PRECIPITATION AMOUNTS.
THOUGH DRY CONDITIONS ARE GENERALLY EXPECTED AFTER 00Z...REMAINING
LOW-LEVEL MOISTURE COULD ALLOW FOR SOME FLURRIES TO CONTINUE
LONGER THAN CURRENTLY FORECAST.
NORTHERN STREAM INFLUENCE OVER THE OHIO VALLEY WILL WANE MARKEDLY
BY THURSDAY...WITH AN ELONGATED WEST-TO-EAST AREA OF HIGH PRESSURE
STRETCHING ACROSS THE REGION...CAUGHT IN BETWEEN LOW PRESSURE
SYSTEMS WELL TO THE NORTH AND SOUTH. WNW FLOW BEHIND THE SHORTWAVE
WILL TURN ADVECTION TO THE COOL SIDE...LEADING TO A DROP IN
TEMPERATURES ON THURSDAY. SKY GRIDS WERE INCREASED THROUGH THIS
PERIOD...AS IT NOW APPEARS UNLIKELY THAT SIGNIFICANT BREAKS IN THE
LOW-LEVEL MOISTURE WILL DEVELOP UNTIL THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL START OUT THE LONG TERM PERIOD. FRIDAY EVENING
INTO FRIDAY NIGHT A SYSTEM WILL MOVE JUST SE OF THE FA. THIS WILL
BRING A CHANCE OF PRECIPITATION TO FAR SE PORTIONS OF THE REGION.
THIS SYSTEM MOVES OUT OF THE REGION BY SATURDAY. SATURDAY AFTERNOON
INTO SATURDAY NIGHT SOME LIGHT PRECIPITATION WILL BE POSSIBLE WITH
WINDS OFF OF LAKE MICHIGAN. KEPT MENTION TO A SLIGHT CHANCE AT THIS
TIME.
MODELS ARE NOT IN AGREEMENT ON A SYSTEM THAT IS EXPECTED TO MOVE
THROUGH THE AREA SUNDAY INTO MONDAY. THE GFS KEEPS MOST OF THE
PRECIPITATION SOUTH OF THE AREA WITH THIS SYSTEM WHILE THE ECMWF
LINGERS PRECIPITATION ACROSS THE AREA THROUGH ALMOST THE ENTIRE
SUNDAY TO MONDAY TIME FRAME. WENT CLOSER TO THE ECMWF SOLUTION
HOWEVER KEPT PRECIPITATION CHANCES CONFINED TO THE CHANGE CATEGORY
FOR MOST LOCATIONS AT THIS TIME. TEMPERATURES WILL BE COOL ENOUGH
THAT ANY PRECIPITATION THAT DOES OCCUR SUNDAY INTO MONDAY WILL BE IN
THE FORM OF SNOW. AFTER THIS TIME HIGH PRESSURE WILL BUILD INTO THE
AREA FOR TUESDAY.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
THE FORECAST AREA WILL BE IN A LULL IN TERMS OF CLOUD COVER AND
PRECIPITATION CHANCES FOR THE REMAINDER OF THIS AFTERNOON. A
BOUNDARY WAS LOCATED ACROSS THE NORTHERN TAF SITES. WILL HAVE TO
WATCH IF LOW LEVEL MOISTURE SNEAKS INTO THE KCMH/KLCK TERMINALS
ON A NORTH/NORTHEAST LOW LEVEL WIND.
FOR TONIGHT...ANOTHER EMBEDDED DISTURBANCE WITHIN THE FLOW ALOFT
WILL MOVE QUICKLY EAST TOWARD OUR AREA. MODELS SUGGEST THAT A WEAK
FRONTAL BOUNDARY WILL PASS FROM WEST TO EAST OVER OUR REGION WHILE
LINGERING BOUNDARY NEAR OUR NORTHERN TERMINALS BECOMES A QUASI-
WARM FRONT. AN INCREASING LOW LEVEL JET AND ISENTROPIC LIFT SHOULD
ALLOW PRECIPITATION TO BREAK OUT BETWEEN KDAY AND KCMH/KLCK
BETWEEN 06Z AND 12Z...EXPANDING IN COVERAGE AS IT LIFTS OUT OF THE
AREA. LOW LEVEL MOISTURE WILL INCREASE OVERNIGHT...NOT ONLY FROM
THE NORTH BUT FROM THE NORTHWEST BEHIND THE WEST TO EAST MOVING
BOUNDARY. ALL LOCATIONS SHOULD DROP INTO MVFR CONDITIONS WITH THE
NORTHERN TAF SITES OF KDAY/KCMH/KLCK HAVING THE BEST CHANCE OF
SEEING IFR CEILINGS. THE THREAT FOR PCPN (RAIN/SNOW MIXED) IS
HIGHEST AT THE KCMH/KLCK TERMINALS AND HAVE PLACED SOME IFR VSBYS
AT THESE SITES BETWEEN 09Z AND 12Z.
ON WEDNESDAY...FAST MOVING DISTURBANCE WILL SHEAR AS IT HEADS
EAST. LOW LEVEL CLOUDS WILL LINGER WITH PERHAPS CEILINGS LIFTING
BACK UP INTO THE MVFR CATEGORY ALL LOCATIONS BY 18Z. SOME
SCATTERED SNOW SHOWERS MAY DEVELOP LATE IN THE DAY...BUT THIS WILL
BE LOOKED AT IN MORE DETAIL WITH THE NEXT TAF ISSUANCE.
OUTLOOK...MVFR/IFR CEILINGS AND MVFR VISIBILITIES LIKELY WEDNESDAY
NIGHT INTO THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1229 PM CST TUE JAN 20 2015
.UPDATE...SURFACE FRONT CONTINUES TO MOVE SLOWLY ACROSS NW MIDDLE
TENNESSEE, WITH PASSAGE EVIDENT AT CKV, BUT NOT YET AT BNA.
SLIGHTLY COOLER AIR IS MOVING IN BEHIND THE FRONT, BUT DEW POINTS
AREN`T SEEMING TO BUDGE. AIR MASS CHANGE WILL INDEED BE SLOW. ONLY
HIGH CLOUDS ARE CURRENTLY FILLING IN BEHIND THE FRONT, SO NO
PRECIPITATION IS EXPECTED AT LEAST THROUGH THE AFTERNOON. HAVE
UPDATED THE GRIDS AND THE PUBLIC FORECAST TO INCREASE TODAY`S HIGH
TEMPERATURES BY A COUPLE OF DEGREES, SINCE WE HAD ALREADY HIT OUR
FORECAST HIGH HERE.
&&
.PREV DISCUSSION... /ISSUED 1147 AM CST TUE JAN 20 2015/
UPDATE...FOR 18Z AVIATION.
AVIATION...18Z TAF DISCUSSION.
AN APPROACHING SHORTWAVE WILL LEAD TO AN INCREASE IN CLOUD COVER
FOR ALL THREE MIDDLE TN TERMINALS. CLOUDS SHOULD STAY IN THE VFR
CATEGORY. MENTIONED VCSH AT CKV. HRRR DOES SHOW SHOWER ACTIVITY
CURRENTLY OVER SE KANSAS AND WESTERN MO HOLDING TOGETHER LONG
ENOUGH TO PRODUCE A LIGHT, BRIEF SHOWER AT THAT TERMINAL. BEHIND
THE SHORTWAVE SKIES SHOULD GO SKC RATHER QUICKLY AT CKV AND BNA.
MOISTURE MAY LINGER A LITTLE LONGER AT CSV. COLD FRONT CURRENTLY
LOCATED NEAR BNA WILL CONTINUE TO PUSH EAST. WINDS AT CKV HAVE
ALREADY VEERED TO THE NW. BNA AND CSV WILL FOLLOW IN THE NEXT FEW
HOURS. WINDS SHOULD STAY LIGHT AFTER THIS EVENING.
REAGAN
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1147 AM CST TUE JAN 20 2015
.UPDATE...FOR 18Z AVIATION.
&&
.AVIATION...18Z TAF DISCUSSION.
AN APPROACHING SHORTWAVE WILL LEAD TO AN INCREASE IN CLOUD COVER
FOR ALL THREE MIDDLE TN TERMINALS. CLOUDS SHOULD STAY IN THE VFR
CATEGORY. MENTIONED VCSH AT CKV. HRRR DOES SHOW SHOWER ACTIVITY
CURRENTLY OVER SE KANSAS AND WESTERN MO HOLDING TOGETHER LONG
ENOUGH TO PRODUCE A LIGHT, BRIEF SHOWER AT THAT TERMINAL. BEHIND
THE SHORTWAVE SKIES SHOULD GO SKC RATHER QUICKLY AT CKV AND BNA.
MOISTURE MAY LINGER A LITTLE LONGER AT CSV. COLD FRONT CURRENTLY
LOCATED NEAR BNA WILL CONTINUE TO PUSH EAST. WINDS AT CKV HAVE
ALREADY VEERED TO THE NW. BNA AND CSV WILL FOLLOW IN THE NEXT FEW HOURS. WINDS
SHOULD STAY LIGHT AFTER THIS EVENING.
REAGAN
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
248 PM CST TUE JAN 20 2015
.DISCUSSION...
AT 2 PM...SURFACE HIGH PRESSURE WAS LOCATED OVER THE NORTHERN GULF
COAST AND A WEAK COLD FRONT EXTENDED FROM PINE BLUFF TO JUST
SOUTH OF DFW TO MAF. MAIN ISSUE IN THE SHORT TERM IS SEA FOG
POTENTIAL...HOW FAR THE FOG WILL MOVE INLAND...TIMING THE ONSET
AND VISIBILITY RESTRICTIONS. WATER TEMPS ARE 50-51 AND SFC DEW PTS
ARE NEAR 60 SO CONDITIONS SEEM RIPE FOR DENSE SEA FOG TO DEVELOP.
THE HRRR DID A GREAT JOB TIMING THE ONSET AND AREA OF FOG
DEVELOPMENT LAST NIGHT SO WILL LEAN TOWARD THE HRRR SOLUTION
TONIGHT. ATTM...DENSE FOG SHOULD DEVELOP NEAR THE COAST BETWEEN
00-01Z AND GRADUALLY EXPAND INLAND. THE WEAK FRONT TO THE NORTH
WILL BE MOVING SOUTH AND WILL CROSS THE CWA BY 09Z. AM NOT SURE
HOW THIS FEATURE WILL AFFECT FOG POTENTIAL LATE TONIGHT. STRONGER
WINDS BEHIND THE BOUNDARY COULD PROVIDE ENOUGH MIXING TO LIFT THE
FOG INTO A LOW STRATUS. A DENSE FOG ADVISORY WILL LIKELY BE
REQUIRED LATER TONIGHT FOR COASTAL COUNTIES AND PROBABLY THE NEXT
TIER OF COUNTIES INLAND.
FCST SOUNDINGS SHOW SATURATION INCREASING ON WEDNESDAY AS
ISENTROPIC UPGLIDE BEGINS. PROBABLY GET SOME VERY LIGHT RAIN
DURING THE DAY...ESPECIALLY IN THE AFTERNOON AS SATURATION
DEEPENS. AN UPPER LEVEL TROUGH OVER CA WILL MOVE EAST ON WEDNESDAY
AND APPROACH THE 4 CORNERS REGION WED NIGHT. WINDS ALOFT WILL
BECOME SOUTHWEST AND A SERIES OF WEAK UPPER LEVEL DISTURBANCES
WILL BEGIN TO TRAVERSE SE TX. IN ADDITION...AN AREA OF LOW
PRESSURE WILL DEVELOP OVER DEEP SOUTH TEXAS AND THIS FEATURE WILL
HELP FOCUS LOW LEVEL CONVERGENCE ACROSS THE COASTAL PLAINS INTO SE
TX BY EARLY THURSDAY. SE TX WILL ALSO LIE IN A STRENGTHENING
120-140 KT RRQ WHICH WILL ALSO ASSIST LIFT. PW VALUES WILL
INCREASE WED NIGHT INTO THURSDAY REACHING 1.50 INCHES AROUND 18Z
THURSDAY. THIS IS 2 STD DEV ABOVE NORMAL FOR THIS TIME OF YEAR.
FCST SOUNDINGS SHOW A SKINNY SATURATED PROFILE FROM THE SFC TO 300
MB SO RAINFALL COULD GET BRIEFLY HEAVY THURSDAY MORNING INTO THE
EARLY AFTN. RAIN SHOULD DIMINISH QUICKLY THURSDAY NIGHT AS THE
COASTAL LOW EXITS THE REGION. THAT SAID...STRONG JET DYNAMICS AND
LIFT ON THE EAST SIDE OF THE TROUGH AXIS SHOULD KEEP PERIODS OF
VERY LIGHT RAIN OR DRIZZLE GOING THROUGH MUCH OF FRIDAY.
UPPER FLOW BECOMES CONFLUENT FRIDAY NIGHT AND MSTR LEVELS BEGIN TO
DROP SO ANY REMAINING LT RAIN WILL COME TO AN END. CLEARING SKIES
ARE EXPECTED FRIDAY NIGHT WITH ONLY PERIODS OF CIRRUS CLOUDS
EXPECTED THROUGH THE WEEKEND. AN EXPANDING UPPER LEVEL RIDGE OVER
CA WILL CREATE A NW FLOW OVER TEXAS KEEPING THINGS DRY AND
SEASONAL FOR MUCH OF NEXT WEEK. THE UPPER FLOW WILL BEGIN TO
FLATTEN TOWARD THE END OF NEXT WEEK AS ANOTHER STORM SYSTEM
APPROACHES THE DESERT SOUTHWEST. 43
&&
.MARINE...
MOIST AND WARM AIR OVER COOLER SHALLOW SHELF WATERS INCREASING THE
PROBABILITY OF RETURN SEA FOG THIS EVENING...QUICKLY BECOMING DENSE
THROUGH MIDNIGHT AND PERSISTING THROUGH A GOOD MAJORITY OF WEDNESDAY
MORNING. IF FOG DOES FORM...VISIBILITIES WILL FALL TO A MILE OR
UNDER THUS PROMPTING AN OVERNIGHT MARINE DENSE FOG ADVISORY. AN
EMERGING WESTERN STORM SYSTEM WILL ORIENT THE LATE WEEK PRESSURE
GRADIENT FROM NORTHEAST TO SOUTHWEST...ULTIMATELY GENERATING A
MODERATE TO STRONG NORTHEASTERLY FETCH THURSDAY...BACKING MORE
NORTHERLY WITH A COLD FRONTAL PASSAGE FRIDAY. THIS FETCH WILL
PRODUCE HIGHER COASTAL WATER LEVELS/TIDES AND CHURN THE OPEN SEAS TO
GREATER THAN 6 FEET NEARSHORE...10 FEET OFFSHORE THURSDAY
NIGHT/EARLY FRIDAY MORNING. OFFSHORE WIND GUSTS TO GALE ARE ALSO
LIKELY DURING THIS THURSDAY-FRIDAY PERIOD OF HIGH WIND...SEAS AND
RAIN. MUCH IMPROVED WEEKEND WEATHER WITH A WEAKENING NORTHWEST TO
WEST WIND UNDER SLIGHTLY WARMER CONDITIONS. 31
&&
.CLIMATE...
HOUSTON REACHED 70 DEGREES AGAIN TODAY. THIS IS THE THIRD
CONSECUTIVE DAY WITH TEMPS AT OR ABOVE 70 DEGREES. THE LAST TIME
HOUSTON RECORDED 3 CONSECUTIVE DAYS WITH TEMPS AT OR ABOVE 70
DEGREES WAS BACK ON DEC 11...DEC 12 AND DEC 13. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 51 64 50 51 40 / 10 20 80 100 40
HOUSTON (IAH) 53 66 54 55 42 / 10 20 60 100 60
GALVESTON (GLS) 54 63 57 58 45 / 10 20 50 100 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1204 PM CST TUE JAN 20 2015
.AVIATION...
THE LAST REMNANTS OF THIS MORNING`S DENSE FOG NOW WHISKING AWAY
AT THE TOP OF THE 18Z HOUR. VFR/SKC WITH A VARIABLE BREEZE THIS
AFTERNOON. AN APPROACHING WEAK NORTHERN BOUNDARY WILL SLOWLY
TRAVEL ACROSS THE REGION EARLY WEDNESDAY...VEERING LOW LEVEL WINDS
TO THE NORTH-NORTHEAST. INTERIOR AND SEA FOG IS FORECAST TO RETURN
WITH THE HIGHER RESOLUTION MODELING BRINGING THE ONSET OF MVFR (OR
LOWER) CATEGORY FOG INTO THE SOUTHERN 1/2 OF REGION JUST AFTER
00Z TONIGHT. AN EARLIER ONSET THAN TODAY WITH A GOOD CHANCE FOR
SIMILAR VISIBILITY RESTRICTIONS WITHIN FOG. THE NORTHERN BOUNDARY
MAY INCREASE NNE FLOW ENOUGH TO LIMIT THE EXTENT OF (L)IFR FOG
DEVELOPMENT ACROSS TERMINALS FROM KIAH NORTHWARD. A TRADITIONALLY
COOLER AND MORE MOIST FLOW DURING THE WINTER MONTHS...AN ESTABLISHED
NORTHEASTERLY WIND SHOULD KEEP MVFR OVERCAST IN PLACE THROUGH THE
WEDNESDAY PM HOURS. 31
&&
.PREV DISCUSSION... /ISSUED 1008 AM CST TUE JAN 20 2015/
UPDATE...
EXTENDED DENSE FOG ADVISORY FOR GALVESTON...CHAMBERS AND LIBERTY
COUNTY THROUGH 18Z. SEE MORNING UPDATE.
DISCUSSION...
FOG IS ERODING RATHER QUICKLY OVER MUCH OF SE TX BUT AREAS OF FOG
CONTINUE TO LINGER IN THE GALVESTON BAY REGION. GHAVE EXTENDED THE
DENSE FOG ADVISORY FOR COUNTIES SURROUNDING THE BAY (EXCLUDING
HARRIS) THROUGH 18Z. HRRR IS HINTING AT DENSE FOG REDEVELOPING
SHORTLY AFTER SUNSET NEAR THE COAST AND EXPANDING INLAND
OVERNIGHT. HAVE ADDED FOG TO THE WEATHER GRIDS FOR TONIGHT. REST
OF THE FCST LOOKS OK. NEW ZONES/NPW OUT SHORTLY. 43
&&
PREV DISCUSSION... /ISSUED 532 AM CST TUE JAN 20 2015/
AVIATION...
DEALING WITH IFR/LIFR CEILINGS AND VISIBILITIES EARLY THIS MORNING
AT ALMOST ALL AREA TAF SITES. EXPECT IMPROVEMENT AROUND MID MORNING
WITH VFR CONDITIONS THROUGHOUT THE AFTERNOON HOURS. COULD SEE ANOTHER
ROUND OF IFR/LIFR CONDITIONS AGAIN TONIGHT INTO WEDNESDAY MORNING AHEAD
OF THE NEXT COLD FRONT. DETERIORATING CEILINGS AND VISIBILITIES INTO
WEDNESDAY NIGHT AND THURSDAY WITH WIDESPREAD R- ASSOCIATED WITH THE
NEXT STORM SYSTEM. 42
&&
PREV DISCUSSION... /ISSUED 354 AM CST TUE JAN 20 2015/
DISCUSSION...
WIDESPREAD FOG IS ONGOING ACROSS SOUTHEAST TEXAS THIS MORNING AS
LIGHT WINDS AND CLEAR SKIES ALLOWED FOR GOOD COOLING WHILE
MOISTURE CONTINUES TO MOVE NORTHWARD INTO THE REGION. DENSE FOG
HAS BEEN MORE PERSISTENT ALONG THE AXIS OF BEST LOW LEVEL MOISTURE
ACROSS OUR WESTERN AND SOUTHWESTERN COUNTIES. VISIBILITIES FURTHER
EAST HAVE DROPPED TO 1/4 MILE OR LESS AT TIMES AND THUS WILL
LEAVE THE CURRENT DENSE FOG ADVISORY IN PLACE FOR ALL OF SOUTHEAST
TEXAS. EXPECT CONDITIONS TO IMPROVE QUICKLY AROUND MID MORNING
WITH ANOTHER RELATIVELY WARM DAY ACROSS SOUTHEAST TEXAS.
ONLY SIGNIFICANT CHANGE TO THE FORECAST THIS MORNING IS TO HOLD
POPS INTO FRIDAY ACROSS MUCH OF THE REGION. A WEAK COLD FRONT
WILL MOVE INTO THE REGION OVERNIGHT BRINGING CLOUDS AND SLIGHTLY
COOLER TEMPERATURES FOR WEDNESDAY. RAIN CHANCES RAMP UP QUICKLY
LATE WEDNESDAY NIGHT AS AN UPPER LEVEL TROUGH DEEPENS ACROSS THE
WESTERN UNITED STATES. AS THIS SYSTEM APPROACHES A COASTAL TROUGH
WILL DEVELOP ON THURSDAY NEAR THE COASTAL BEND REGION WHILE
PERSISTENT ISENTROPIC UPGLIDE COMBINED WITH A FAVORABLE JET
POSITION WILL SUPPORT WIDESPREAD RAINFALL ACROSS SOUTHEAST TEXAS
THURSDAY. RAINFALL AMOUNTS WILL AVERAGE BETWEEN 1-2 INCHES ALTHOUGH
SOME ISOLATED 3+ INCH TOTALS ARE POSSIBLE. THE BULK OF THE
PRECIPITATION WILL EXIT TO THE EAST THURSDAY NIGHT BUT MODELS
CONTINUE TO SLOW THE PROGRESSION OF THE UPPER TROUGH...AND THUS
WILL HOLD ONTO POPS A BIT FURTHER INTO FRIDAY. SKIES WILL CLEAR
OVER THE WEEKEND AS ANOTHER UPPER TROUGH DIGS INTO THE
SOUTHEASTERN UNITED STATES. THIS WILL ALLOW FOR PERSISTENT
NORTHWEST FLOW ALOFT AND DRY AND SEASONABLE CONDITIONS THROUGH
THE MIDDLE OF NEXT WEEK. 38
&&
MARINE...
LIGHT MAINLY SOUTH WINDS WILL PERSIST THROUGH TUESDAY NIGHT.
SOME PATCHY SEA FOG IS POSSIBLE AS WARMER AND MORE MOIST AIR
OVERRIDES THE COOLER SHELF WATERS. EAST TO NORTHEAST WINDS
RETURN TO THE AREA WEDNESDAY AND STRENGTHEN THROUGH FRIDAY
MORNING AHEAD OF AN APPROACHING STORM SYSTEM. THIS SYSTEM
WILL BRING STRONG WINDS (GUSTS POSSIBLY REACHING GALE FORCE
LATE THURSDAY AFTERNOON THROUGH EARLY FRIDAY MORNING)...ROUGH
SEAS...RAIN...AND TIDE LEVELS ABOVE TO MUCH ABOVE NORMAL.
SMALL CRAFT ADVISORIES WILL BE NEEDED. WINDS WILL BECOME MORE
NORTHERLY AS THE DAY PROGRESSES ON FRIDAY WITH THE STORM
SYSTEM EDGING OFF TO THE EAST. LIGHTER NORTH TO NORTHWEST
WINDS WILL PREVAIL OVER THE WEEKEND. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 49 64 49 49 / 0 0 20 80 100
HOUSTON (IAH) 72 50 66 52 56 / 0 10 20 50 90
GALVESTON (GLS) 67 56 63 54 60 / 0 10 20 50 90
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
CHAMBERS...GALVESTON...LIBERTY.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20
NM.
&&
$$
DISCUSSION...31
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1008 AM CST TUE JAN 20 2015
.UPDATE...
EXTENDED DENSE FOG ADVISORY FOR GALVESTON...CHAMBERS AND LIBERTY
COUNTY THROUGH 18Z. SEE MORNING UPDATE.
&&
.DISCUSSION...
FOG IS ERODING RATHER QUICKLY OVER MUCH OF SE TX BUT AREAS OF FOG
CONTINUE TO LINGER IN THE GALVESTON BAY REGION. GHAVE EXTENDED THE
DENSE FOG ADVISORY FOR COUNTIES SURROUNDING THE BAY (EXCLUDING
HARRIS) THROUGH 18Z. HRRR IS HINTING AT DENSE FOG REDEVELOPING
SHORTLY AFTER SUNSET NEAR THE COAST AND EXPANDING INLAND
OVERNIGHT. HAVE ADDED FOG TO THE WEATHER GRIDS FOR TONIGHT. REST
OF THE FCST LOOKS OK. NEW ZONES/NPW OUT SHORTLY. 43
&&
.PREV DISCUSSION... /ISSUED 532 AM CST TUE JAN 20 2015/
AVIATION...
DEALING WITH IFR/LIFR CEILINGS AND VISIBILITIES EARLY THIS MORNING
AT ALMOST ALL AREA TAF SITES. EXPECT IMPROVEMENT AROUND MID MORNING
WITH VFR CONDITIONS THROUGHOUT THE AFTERNOON HOURS. COULD SEE ANOTHER
ROUND OF IFR/LIFR CONDITIONS AGAIN TONIGHT INTO WEDNESDAY MORNING AHEAD
OF THE NEXT COLD FRONT. DETERIORATING CEILINGS AND VISIBILITIES INTO
WEDNESDAY NIGHT AND THURSDAY WITH WIDESPREAD R- ASSOCIATED WITH THE
NEXT STORM SYSTEM. 42
PREV DISCUSSION... /ISSUED 354 AM CST TUE JAN 20 2015/
DISCUSSION...
WIDESPREAD FOG IS ONGOING ACROSS SOUTHEAST TEXAS THIS MORNING AS
LIGHT WINDS AND CLEAR SKIES ALLOWED FOR GOOD COOLING WHILE
MOISTURE CONTINUES TO MOVE NORTHWARD INTO THE REGION. DENSE FOG
HAS BEEN MORE PERSISTENT ALONG THE AXIS OF BEST LOW LEVEL MOISTURE
ACROSS OUR WESTERN AND SOUTHWESTERN COUNTIES. VISIBILITIES FURTHER
EAST HAVE DROPPED TO 1/4 MILE OR LESS AT TIMES AND THUS WILL
LEAVE THE CURRENT DENSE FOG ADVISORY IN PLACE FOR ALL OF SOUTHEAST
TEXAS. EXPECT CONDITIONS TO IMPROVE QUICKLY AROUND MID MORNING
WITH ANOTHER RELATIVELY WARM DAY ACROSS SOUTHEAST TEXAS.
ONLY SIGNIFICANT CHANGE TO THE FORECAST THIS MORNING IS TO HOLD
POPS INTO FRIDAY ACROSS MUCH OF THE REGION. A WEAK COLD FRONT
WILL MOVE INTO THE REGION OVERNIGHT BRINGING CLOUDS AND SLIGHTLY
COOLER TEMPERATURES FOR WEDNESDAY. RAIN CHANCES RAMP UP QUICKLY
LATE WEDNESDAY NIGHT AS AN UPPER LEVEL TROUGH DEEPENS ACROSS THE
WESTERN UNITED STATES. AS THIS SYSTEM APPROACHES A COASTAL TROUGH
WILL DEVELOP ON THURSDAY NEAR THE COASTAL BEND REGION WHILE
PERSISTENT ISENTROPIC UPGLIDE COMBINED WITH A FAVORABLE JET
POSITION WILL SUPPORT WIDESPREAD RAINFALL ACROSS SOUTHEAST TEXAS
THURSDAY. RAINFALL AMOUNTS WILL AVERAGE BETWEEN 1-2 INCHES ALTHOUGH
SOME ISOLATED 3+ INCH TOTALS ARE POSSIBLE. THE BULK OF THE
PRECIPITATION WILL EXIT TO THE EAST THURSDAY NIGHT BUT MODELS
CONTINUE TO SLOW THE PROGRESSION OF THE UPPER TROUGH...AND THUS
WILL HOLD ONTO POPS A BIT FURTHER INTO FRIDAY. SKIES WILL CLEAR
OVER THE WEEKEND AS ANOTHER UPPER TROUGH DIGS INTO THE
SOUTHEASTERN UNITED STATES. THIS WILL ALLOW FOR PERSISTENT
NORTHWEST FLOW ALOFT AND DRY AND SEASONABLE CONDITIONS THROUGH
THE MIDDLE OF NEXT WEEK. 38
MARINE...
LIGHT MAINLY SOUTH WINDS WILL PERSIST THROUGH TUESDAY NIGHT.
SOME PATCHY SEA FOG IS POSSIBLE AS WARMER AND MORE MOIST AIR
OVERRIDES THE COOLER SHELF WATERS. EAST TO NORTHEAST WINDS
RETURN TO THE AREA WEDNESDAY AND STRENGTHEN THROUGH FRIDAY
MORNING AHEAD OF AN APPROACHING STORM SYSTEM. THIS SYSTEM
WILL BRING STRONG WINDS (GUSTS POSSIBLY REACHING GALE FORCE
LATE THURSDAY AFTERNOON THROUGH EARLY FRIDAY MORNING)...ROUGH
SEAS...RAIN...AND TIDE LEVELS ABOVE TO MUCH ABOVE NORMAL.
SMALL CRAFT ADVISORIES WILL BE NEEDED. WINDS WILL BECOME MORE
NORTHERLY AS THE DAY PROGRESSES ON FRIDAY WITH THE STORM
SYSTEM EDGING OFF TO THE EAST. LIGHTER NORTH TO NORTHWEST
WINDS WILL PREVAIL OVER THE WEEKEND. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 49 64 49 49 / 0 0 20 80 100
HOUSTON (IAH) 72 50 66 52 56 / 0 10 20 50 90
GALVESTON (GLS) 67 56 63 54 60 / 0 10 20 50 90
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
CHAMBERS...GALVESTON...LIBERTY.
GM...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM.
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20
NM.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1143 AM CST TUE JAN 20 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 337 AM CST TUE JAN 20 2015
PCPN TRENDS AND TYPE WILL BE THE MAIN FCST CONCERNS.
A S/W TROF OVER SW WI/NE IA/NW IL AND SOME MID-LEVEL (800-700 MB)
FRONTOGENETIC FORCING WAS PRODUCING BANDED SNOWFALL AND ACCUMS OF
1-2 INCHES OVER C/EC WI EARLY THIS MORNING. SOME FZDZ WAS ALSO
BEING REPORTED IN AREAS WHERE THE SNOW WAS TAPERING OFF. WV
IMAGERY AND RUC ANALYSES SHOWED AN UPPER LOW OVER NORTH DAKOTA.
THIS SYSTEM IS EXPECTED TO AFFECT MAINLY C/EC WI TONIGHT INTO
WEDNESDAY.
SNOW SHOULD TAPER OFF OVER ALL BUT EAST CENTRAL WI BY DAYBREAK...
BUT THERE WILL BE SOME PATCHY FZDZ OVER MAINLY C/EC WI INTO THE
MORNING HOURS. IT IS POSSIBLE THAT A LITTLE FZDZ MAY LINGER OVER
OUR FAR SW/S COUNTIES THROUGH THE DAY...BUT MOST PLACES SHOULD
SEE A BREAK IN THE PCPN. EXPECT HIGH TEMPS TO WARM INTO THE
20S...WITH UPPER 20S AND LOWER 30S SOUTH.
AS THE NORTH DAKOTA UPPER LOW TRACKS TOWARD SW WI...SOME LIGHT
SNOW AND FZDZ IS EXPECTED TO REDEVELOP OVER CENTRAL AND PARTS OF
EAST CENTRAL WI DURING THE EVG AND OVERNIGHT. SNOW ACCUMS SHOULD
BE UNDER AN INCH...WITH THE HIGHEST ACCUMS IN OUR FAR SW COUNTIES.
PATCHY LIGHT SNOW WILL CONTINUE IN C/EC WI INTO WEDS MORNING...
THEN GRADUALLY DECREASE AS THE UPPER LOW TRACKS SE OF THE REGION
IN THE AFTERNOON. SOME LIGHT LAKE-EFFECT MAY DEVELOP OVER NC WI
AS LIGHT NORTH WINDS DEVELOP. LOWS TONIGHT SHOULD BE IN THE TEENS
AND LOWER 20S...WITH HIGHS MAINLY 25 TO 30 ON WEDNESDAY.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 337 AM CST TUE JAN 20 2015
500MB RIDGE WILL DOMINATE THE WEATHER PATTERN WITH SPLIT FLOW
NOTED ACROSS THE EASTERN HALF OF NORTH AMERICA. THIS PATTERN
WILL LEAD TO THE MORE SIGNIFICANT STORMS STAYING WELL SOUTH
OF THE AREA WHILE WEAK CLIPPER SYSTEMS WILL DROP SOUTHEAST OUT OF
CANADA. THE BIGGEST BENEFIT WITH THIS PATTERN IS THE TRUE ARCTIC
AIR WILL REMAIN UP IN CANADA...ALTHOUGH THEIR ARE HINTS IT MAY
DROP SOUTH INTO OUR AREA BEYOND THE FORECAST PERIOD.
FIRST CLIPPER SYSTEM AND ASSOCIATED COLD FRONT WILL MOVE ACROSS
THE AREA ON FRIDAY. PRECIPITATION TYPE MAY BE AN ISSUE WITH
WARM AIR FLOWING INTO THE SYSTEM. BUFKIT SOUNDINGS WOULD
SUGGEST PARTIAL OR COMPLETE MELTING OF ANY SNOWFLAKES AND
MAY REFREEZE BELOW 850MB DUE TO DRY AIR AROUND 925MB. ADDED
SLEET TO THE FORECAST ON FRIDAY...AND A LITTLE RAIN ACROSS THE
EAST FRIDAY AFTERNOON DUE TO MILD TEMPERATURES AHEAD OF COLD
FRONT.
THE NEXT CLIPPER SYSTEM FOR SATURDAY NIGHT AND SUNDAY APPEARS
TO BE MOVING SOUTHWEST OF THE AREA. WILL HAVE THE HIGHEST CHANCES
FOR SNOW ACROSS THE SOUTH. LATER SHIFTS MAY BE ABLE TO REMOVE
CHANCES ACROSS PORTIONS OF THE NORTH IF THIS SCENARIO HOLDS TRUE.
ANOTHER ONE OR TWO CLIPPER SYSTEMS WILL MOVE ACROSS THE REGION
EARLY NEXT WEEK. IT IS TOO FAR OUT TO PINPOINT WHERE HIGHEST
CHANCES OF LIGHT SNOW WOULD OCCUR ACROSS THE REGION DUE TO
TIMING AND LOCATION DIFFERENCES. DID RAISE TEMPERATURES UP A
DEGREES OR TWO FROM THURSDAY INTO THE WEEKEND.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1142 AM CST TUE JAN 20 2015
DRY CONDITIONS ARE EXPECTED FOR THE EARLY AFTERNOON HOURS...AS THE
AREA IS IN BETWEEN WEAK WEATHER SYSTEMS. THE NEXT UPPER LEVEL
DISTURBANCE AND SURFACE LOW PRESSURE WILL PUSH ACROSS SOUTHERN MN
AND SOUTHERN WI TONIGHT INTO WEDNESDAY AM. THE SYSTEM IS TRACKING
SLIGHTLY SLIGHTLY FARTHER SOUTH THAN THE SYSTEM LAST NIGHT...SO
MOST OF THE ACCUMULATING SNOW WILL PASS SOUTH OF THE AREA...
HOWEVER WILL INCLUDE SOME -SN WITH MVFR/VFR VSBYS TO COVER ANY
LIGHT SNOW OR FLURRIES THAT MAKE IT INTO AUW/CWA/GRB/ATW/MTW. THE
CHANCES FOR ANY ACCUMULATIONS INCREASE AS YOU MOVE SOUTH OF A
MARSHFIELD TO OSHKOSH LINE. MODELS SOUNDINGS SHOW A THREAT OF
FREEZING DRIZZLE MIXING IN WITH THE LIGHT SNOW AS MID-LEVEL
MOISTURE WILL BE LACKING ON THE NORTH SIDE OF THE LOW PRESSURE
SYSTEM. WILL MENTION OF -FZDZ ALONG WITH -SN TO COVER THIS
THREAT...BUT CONFIDENCE IS LOW. RHI LOOKS TO REMAIN DRY TONIGHT...
THEN THERE IS A SMALL CHANCE OF A SNOW SHOWER WEDNESDAY PM AS SOME
LAKE EFFECT ACTIVITY FROM LAKE SUPERIOR COULD APPROACH NORTH-
CENTRAL WI...BUT WILL NOT INCLUDE A MENTION AT THIS TIME. AS FOR
CLOUDS...THICK CLOUD COVER IS FORECAST TO REMAIN OVER THE AREA
THROUGH WEDNESDAY. HIGH IFR TO LOW MVFR CIGS ARE EXPECTED TONIGHT
INTO WEDNESDAY AM. A CLEARING LINE IS APPROACHING FROM THE WI/MI
BORDER...BUT THAT WILL COME UP WELL SHORT OF MAKING INTO THE TAF
SITES. SOME PATCHY FOG IS POSSIBLE OVERNIGHT ACROSS NORTHERN WI AS
WELL.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....KIECKBUSCH
LONG TERM......ECKBERG
AVIATION.......BERSCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
211 PM MST TUE JAN 20 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 300 PM MST TUE JAN 20 2015
COLD AIR MASS TO REMAIN IN PLACE WITH 700MB TEMPERATURES OF -14 TO
-16C TODAY THROUGH WEDNESDAY NIGHT. SURFACE TEMPERATURES COLD WITH
OVERNIGHT LOWS IN THE SINGLE DIGITS TO LOW TEENS AND DAYTIME HIGHS
STRUGGLING TO GET ABOVE FREEZING. THIS IS DUE TO A SLOW MOVING UPPER
LOW THAT TRACKS ACROSS COLORADO THROUGH THURSDAY THAT KEEPS A NORTH
WIND OVER THE AREA.
WILL STAY DRY FOR THE MOST PART...MAYBE SOME SCATTERED SNOW SHOWERS
OVER THE SNOWY AND SIERRA MADRE RANGES...BUT THATS ABOUT IT. START
TO SEE A CHANGE THURSDAY NIGHT AS THE LOW FINALLY TRACKS OFF TO THE
SOUTHEAST WITH UPPER LEVEL RIDGING BUILDING BACK OVER WYOMING. 700MB
TEMPERATURES WARM UP ABOUT 8 DEGREES C INTO THURSDAY MORNING TO -6
TO -10C. NO ISSUES WITH WINDS OR PRECIP THROUGH THE SHORT TERM.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 300 PM MST TUE JAN 20 2015
THE LATEST MEDIUM RANGE MODELS AND THEIR ENSEMBLES ARE IN GENERAL
AGREEMENT. THE LARGE SCALE PATTERN WILL BE DOMINATED BY A WESTERN
CONUS UPPER RIDGE AND EASTERN CONUS UPPER TROUGH. CONSEQUENTLY...
NORTHWEST FLOW ALOFT WILL PREVAIL. NO SENSIBLE WEATHER IS FORECAST
FRIDAY WITH BREEZY NORTHWEST WINDS. DOWNSLOPE FLOW LEE OF THE LARAMIE
RANGE WILL PUSH THE MERCURY INTO THE 40S DURING THE AFTERNOON. A
CLIPPER LOW PRESSURE SYSTEM AND COLD FRONT WILL MOVE SOUTHEAST
ACROSS THE NORTHERN PLAINS AND MIDWEST LATE SATURDAY THROUGH
SUNDAY. THE ECMWF/GEM ARE PRODUCING SOME LIGHT PRECIPITATION OVER
EAST CENTRAL WY AND THE SOUTHEAST WY MOUNTAINS SATURDAY AFTERNOON
AND NIGHT. AS THIS CLIPPER PASSES TO THE NORTHEAST OF THE CWFA
SATURDAY...THE PRESSURE GRADIENT TIGHTENS ACROSS SOUTHEAST WY WITH
WEST WINDS GUSTING TO 40 KT THROUGH WIND PRONE AREAS. DOWNSLOPE
FLOW ONCE AGAIN WILL PROVIDE ABOVE NORMAL HIGH TEMPERATURES. UPPER
RIDGE AMPLIFIES SUNDAY WITH ANOTHER SHORTWAVE MOVING SOUTHEAST
THROUGH THE NORTHERN HIGH PLAINS. GFS DEPICTS LITTLE OR NO
PRECIPITATION WHILE THE ECMWF/GEM PRODUCE A BAND OF LIGHT QPF FROM
NORTHERN WY INTO NORTHWEST NE. REGARDLESS...THE MAJORITY OF THE
CWFA WILL BE DRY SUNDAY...EXCEPT FOR ISOLATED OROGRAPHIC SNOW
SHOWERS OVER THE SNOWY/SIERRA MADRE RANGES. AS THE UPPER RIDGE
MOVES OVERHEAD EARLY NEXT WEEK...EXPECT DRY AND UNSEASONABLY MILD
CONDITIONS WITH HIGHS INTO THE 50S FOR THE PLAINS. WEST TO NORTHWEST
WINDS WILL BE BREEZY...MAINLY DURING THE DAYTIME HOURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1050 AM MST TUE JAN 20 2015
EXPECT CIGS BETWEEN 5000 AND 10000 KT AGL ALONG/EAST OF LARAMIE RANGE
THIS AFTERNOON...BECOMING SCATTERED THIS EVENING. LATEST HRRR GUIDANCE
BRINGS IN LOWER CIGS WEST OF LARAMIE RANGE LATE THIS AFTERNOON WITH
RWL/SAA AIRFIELDS FLIRTING WITH MVFR THROUGH WEDNESDAY MORNING. IT
WILL BE BREEZY THIS AFTERNOON WITH W-NW SURFACE WINDS GUSTING TO 25
KT...HIGHER IN AND NEAR THE SE WY MOUNTAINS. WINDS WILL DIMINISH THIS
EVENING.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MST TUE JAN 20 2015
MINIMAL FIRE WEATHER CONCERNS AS A COLD FRONT WILL REMAIN OVER THE
AREA THROUGH THE NEXT COUPLE DAYS. WILL SEE SOME MOUNTAIN SNOW...BUT
ACCUMULATIONS WILL BE LIGHT. AFTERNOON HUMIDITIES WELL ABOVE CRITICAL
THRESHOLDS WITH EXCELLENT OVERNIGHT RECOVERIES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...GCC
LONG TERM...MJ
AVIATION...MJ
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1056 AM MST TUE JAN 20 2015
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 400 AM MST TUE JAN 20 2015
QUIET WEATHER THROUGH THURSDAY NIGHT WITH VERY FEW FORECAST CONCERNS.
A STRUNG OUT AREA OF VORTICITY WILL PROVIDE ENOUGH LIFT FOR SOME
LIGHT SNOW TODAY. VERY LITTLE IN THE WAY OF ACCUMULATION IS EXPECTED
BUT THERE IS THE POTENTIAL FOR A FEW VERY NARROW BANDS OF SNOW WHICH
COULD PRODUCE SOME ACCUMULATION IN THE PLAINS OF SOUTHEAST WYOMING.
THERE IS SOME LOW LEVEL INSTABILITY IN PLACE TODAY BUT WITH WEAK
FRONTOGENESIS AND WEAK UPPER LEVEL SUPPORT...EVEN BANDED PRECIPITATION
IS NOT A SURE THING.
COOLER AIR WILL PUSH INTO THE AREA TODAY AND TONIGHT WITH THE COLDEST
AIR IN PLACE WEDNESDAY WITH HIGHS MAINLY IN THE 20S AND LOWS IN THE
SINGLE DIGITS WEDNESDAY NIGHT. DID NOT MENTION CHANCES FOR PRECIPITATION
WEDNESDAY BUT GIVEN COOL NORTHWEST FLOW ALOFT AND A WEAK SHORTWAVE
THERE COULD BE SOME SNOW FLURRY ACTIVITY...ESPECIALLY LATE MORNING
AND AFTERNOON AS THE LOW LEVELS DESTABILIZE.
NO CHANCES FOR PRECIPITATION THURSDAY UNDER CLEAR SKIES AND WESTERLY
DOWNSLOPE FLOW. TEMPERATURES WILL REBOUND WITH THE CLEAR SKIES AND
WARMING TEMPERATURES ALOFT AS A BROAD UPPER RIDGE BEGINS TO BUILD
ACROSS THE ROCKIES.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 400 AM MST TUE JAN 20 2015
SOMEWHAT MILDER THAN AVERAGE TEMPERATURES EXPECTED OVERALL ACROSS
THE CWA DURING THIS PERIOD UNDER A GENERALLY NW FLOW ALOFT BETWEEN
RIDING OVER THE WESTERN CONUS AND DEEP TROFFING ACROSS THE EASTERN
CONUS. BEST CHANCE FOR ANY PCPN LOOKS TO BE SATURDAY NIGHT AS AN
UPPER TROF DROPS RATHER QUICKLY SE IN THE FLOW AND ACROSS THE AREA.
ARCTIC AIR WILL REMAIN CUT OFF AND WELL TO THE NORTH OF THE AREA
WITH MODIFIED PACIFIC AIR CONTINUING ACROSS THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1050 AM MST TUE JAN 20 2015
EXPECT CIGS BETWEEN 5000 AND 10000 KT AGL ALONG/EAST OF LARAMIE RANGE
THIS AFTERNOON...BECOMING SCATTERED THIS EVENING. LATEST HRRR GUIDANCE
BRINGS IN LOWER CIGS WEST OF LARAMIE RANGE LATE THIS AFTERNOON WITH
RWL/SAA AIRFIELDS FLIRTING WITH MVFR THROUGH WEDNESDAY MORNING. IT
WILL BE BREEZY THIS AFTERNOON WITH W-NW SURFACE WINDS GUSTING TO 25
KT...HIGHER IN AND NEAR THE SE WY MOUNTAINS. WINDS WILL DIMINISH THIS
EVENING.
&&
.FIRE WEATHER...
ISSUED AT 400 AM MST TUE JAN 20 2015
NO FIRE WEATHER CONCERNS WITH LIGHT WINDS ACROSS THE AREA THE NEXT
SEVERAL DAYS. COOLER TEMPERATURES TUESDAY AND WEDNESDAY THEN A
WARMING TREND INTO THE WEEKEND. A FEW LIGHT SNOW SHOWERS POSSIBLE
TODAY OTHERWISE DRY THROUGH AT LEAST THURSDAY NIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...SML
LONG TERM...RE
AVIATION...MJ
FIRE WEATHER...SML