Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/04/16
AREA FORECAST DISCUSSION
NWS ALBANY NY
115 AM EST SAT JAN 2 2016
.SYNOPSIS...
A DISTURBANCE WILL KEEP OUR WEATHER A LITTLE UNSETTLED
THROUGH EVENING...WITH ADDITIONAL SNOW SHOWERS...ESPECIALLY NORTH
AND WEST OF THE CAPITAL REGION. CLOUDS WILL LINGER INTO THE
OVERNIGHT WHILE LAKE EFFECT SNOWS CONTINUE ACROSS THE ADIRONDACKS.
OUTSIDE OF LAKE EFFECT TO THE WEST OF THE HUDSON VALLEY...SATURDAY
LOOKS DRY WITH SEASONABLE TEMPERATURES. THEN A COLD FRONT WILL USHER
IN MUCH COLDER AIR LATE SUNDAY INTO THE EARLY PORTION OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LAKE EFFECT SNOW ADVISORY NOW IN EFFECT FOR SOUTHERN
HERKIMER/NORTHERN FULTON COS...LAKE EFFECT SNOW WARNING
FOR NORTHERN HERKIMER AND HAMILTON COUNTIES THROUGH 7
PM EST SAT....
AS OF 100 AM EST...ONE LAST SHORT WAVE CONTINUED LAKE EFFECT SNOW
ACROSS HERKIMER...SOUTHERN HAMILTON COUNTY...WORKING DOWN
THE MOHAWK VALLEY. OTHERWISE...RADARS SHOWING LITTLE IF ANY
SNOW ACTIVITY OUTSIDE OF THIS AREA.
THE LATEST HRRR HAS A PRETTY GOOD HANDLE ON THIS...AND INDICATED THE
BANDS PERSIST...OCCASIONALLY WORKING INTO THE CAPITAL REGION AND
EVEN BERKSHIRES THROUGH THE OVERNIGHT.
WE WILL KEEP ALL HEADLINES IN TACT EVEN THOUGH THIS BANDS HAVE BEEN SOMEWHAT
MIGRATORY. ONCE THE SHORT WAVE MOVES THROUGH...THE FLOW LOOKS TO
BACK FROM WNW TO WSW SO THE ADIRONDACKS SHOULD GET SEVERAL INCHES MORE
OF SNOW TODAY...AND EVEN PORTIONS OF THE MOHAWK VALLEY.
EVEN THE CAPITAL REGION AND SURROUNDING AREAS COULD GET UP TO
AN INCH IN SPOTS...BUT PROBABLY LESS. SOME UPSLOPE AREAS OF
THE CATSKILLS/BERKSHIRES AND THE SOUTHERN GREENS COULD SEE
LOCALIZED AMOUNTS UP TO TWO INCHES.
IT REMAINS MOSTLY CLOUDY FROM THE CAPITAL REGION NORTHWARD...
LESS CLOUDS FURTHER SOUTH.
TEMPERATURES LOOK TO ONLY FALL A FEW DEGREES OVERNIGHT DUE TO A
PERSISTENT WESTERLY BREEZE 5-10 MPH. LOOK FOR LOWS GENERALLY IN
THE 20S...WITH SOME TEENS IN THE ADIRONDACKS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
BY SATURDAY...AS THE FLOW BACK WSW AND EVENTUALLY
THE SUBSIDENCE INVERSION WILL LOWER. LAKE EFFECT SNOW SHOWER
ACTIVITY WILL SLOWLY WEAKEN...BUT NOT BEFORE GIVING A FEW
ADDITIONAL INCHES ESPECIALLY NEAR OLD FORGE.
THE REMAINDER OF THE AREA LOOKS MAINLY DRY WITH NOTHING MORE
THAN A FEW FLURRIES. IT WILL PARTLY SUNNY AND BRISK BUT
TEMPERATURES STILL RUNNING A LITTLE ABOVE NORMAL. LOOKS
FOR HIGHS SATURDAY 25-30 ACROSS THE HIGHER TERRAIN...30S
IN THE VALLEYS...LOCALLY MID 30S ACROSS THE CAPITAL REGION.
THERE STILL WILL BE SOME LINGERING LIGHT SNOW SHOWERS ACROSS
ADIRONDACKS SATURDAY NIGHT...WITH PERHAPS AN INCH OR TWO
ADDITIONAL ACCUMULATIONS. OTHERWISE IT WILL PARTLY CLOUDY
AND DRY WITH LOWS IN THE 20S.
SUNDAY WILL START DRY. THEN..A POTENTIAL CLIPPER TYPE SYSTEM
(CURRENTLY OVER MINNESOTA) WILL DRIVE THE COLDEST AIR MASS OF THE
SEASON OUR WAY LATE SUNDAY INTO EARLY MONDAY. ITS LEADING
EDGE...AN ARCTIC BOUNDARY COULD TOUCH OFF WIDESPREAD SNOW SHOWERS
AND EVEN SOME SNOW SQUALLS LATE IN THE DAY...AS THE ATMOSPHERE
BECOMES VERY UNSTABLE ONCE MORE...AND THIS IS A STRONG COLD FRONT.
THE POTENTIAL IS THERE FOR ANY OF THESE POSSIBLE SNOW SQUALLS TO
BRING A QUICK COATING TO A COUPLE OF INCHES OF SNOW IN SOME PLACES
IN A SHORT INTERVAL OF TIME. THE BEST THREAT OF THESE LOOK TO BE
LATER IN THE DAY PERHAPS EARLY EVENING. WE WILL FINE TUNE AS WE
GET CLOSER TO THE POSSIBLE EVENT.
GUSTY WINDS TO 30-35 MPH OUT OF THE NORTHWEST WILL ACCOMPANY THE FRONT
AS WELL.
HIGHS ON SUNDAY WILL RANGE FROM AROUND 30 NORTHWEST...TO NEAR 40 SOUTHEAST
OF ALBANY...BUT TEMPERATURES WILL FALL QUICKLY BEHIND THIS FRONT...
LIKELY BELOW FREEZING EVERYWHERE BY DARK ALONG WITH A GUSTY NORTHWEST WIND.
SUNDAY NIGHT...IT TURNS MIGHTY COLD. ARCTIC AIR WOULD PRODUCE
SOME UPSLOPE SNOW SHOWERS...ESPECIALLY ACROSS THE ADIRONDACKS AND
SOUTHERN GREENS. THE FLOW LOOKS TO NORTHWEST FOR MOST FRAGMENTED
LAKE BANDS TO REACH OUR AREA...BUT A FEW COULD CLIP THE SOUTHERN
CATSKILLS.
TEMPERATURES WILL DROP DURING THE EVENING...BOTTOMING OUT NEAR 0
ACROSS THE ADIRONDACKS...SINGLE NUMBERS REMAINING PORTIONS OF OUR
NORTHERN ZONES...TEENS FROM THE CAPITAL REGION SOUTH. THIS WILL BE
THE FIRST SUB 20 READINGS IN THE CAPITAL REGION...THE LATEST THIS
HAS EVEN HAPPEN ANY WINTER SEASON.
TUESDAY LOOKS MAINLY DRY WITH A PARTLY TO MOSTLY SUNNY SKY. HOWEVER
THAT SUNSHINE WILL DO LITTLE TO WARM THINGS UP. HIGHS WILL STRUGGLE
TO REACH BACK INTO THE SINGLE NUMBERS ACROSS THE ADIRONDACKS...TEENS
REMAINDER OF THE NORTHERN REGION...NEAR 20 CAPITAL REGION...LOWER
TO MID 20S FURTHER SOUTH. A BREEZE OUT OF THE NORTH OR NORTHWEST
WILL MAKE IT FEEL EVEN COLDER.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE COLDEST AIR MASS OF THE COOL SEASON THUS FAR BEGINS TO RETREAT
AS WE HEAD THROUGH THE EARLY PART OF THE EXTENDED. HIGH PRESSURE
FIRMLY IN PLACE BEGINS TO WEAKEN ON FRIDAY...BUT THERE IS NO
PRECIPITATION ANTICIPATED THROUGHOUT THE PERIOD. SUNSHINE WILL BE
ABUNDANT THROUGH MIDWEEK...BUT MORE IN THE WAY OF CLOUDS IS EXPECTED
FOR FRIDAY AS A DRY COLD FRONT WORKS TOWARD OUR ZONES FROM THE NORTH.
HIGH TEMPERATURES WILL BE IN ONLY THE TEENS AND 20S ON TUESDAY...
WITH AN ADDITIONAL 5 DEGREES FOR WEDNESDAY AND THEN AGAIN THURSDAY.
FRIDAY/S HIGHS WILL BE ABOUT THE SAME AS THURSDAY/S. THE COLD WILL
BE DOWNRIGHT BONE-CHILLING MONDAY NIGHT WITH OVERNIGHT LOWS RANGING
FROM AROUND 5 TO 10 DEGREES BELOW ZERO IN THE WESTERN ADIRONDACKS...
TO AS MILD AS 10 DEGREES IN THE LOWER MID-HUDSON VALLEY. READINGS
WILL BOUNCE BACK TO LOWS IN THE SINGLE DIGITS AND TEENS TUESDAY
NIGHT...AND FURTHER TO THE MID TEENS TO LOWER 20S RANGE WEDNESDAY
NIGHT. THURSDAY NIGHT WILL BE MILDER STILL WITH LOWS FROM THE MID
TEENS TO UPPER 20S.
NORMAL HIGH TEMPERATURES IN ALBANY ARE IN THE LOW 30S...WITH NORMAL
LOWS IN THE MID TEENS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
MAINLY VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD ENDING 06Z
SUNDAY. HOWEVER...WE ARE STILL DEALING WITH A STRONG UPPER LEVEL
DISTURBANCE AS IT FINALLY MOVES PAST THE TAF SITES OVERNIGHT. RESIDUAL
SCATTERED SNOW SHOWERS WILL PERSIST DOWN THE MOHAWK VALLEY AND
COULD PRODUCE BRIEF MVFR CONDITIONS....MAINLY AT KALB THROUGH 10Z.
OTHERWISE IT IS VFR SATURDAY WITH A WEST WIND AROUND 10KTS...GUSTING
TO NEAR 18KTS AT KALB. IT WILL PARTLY SUNNY WITH SCT-BKN CIGS
AROUND 4000 FEET AGL.
OUTLOOK...
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO ISSUES ARE ANTICIPATED THROUGH THE NEXT 5 DAYS.
ASIDE FROM SOME SNOW SHOWERS...MAINLY DRY WEATHER IS EXPECTED
THROUGH THE HOLIDAY WEEKEND INTO EARLY NEXT WEEK.
COLDER TEMPS WILL CONTINUE TO ALLOW FOR THE RIVERS AND STREAMS TO
SLOWLY RECEDE...WITH SOME ICE FORMATION MONDAY AND TUESDAY AS EVEN
COLDER AIR MOVES IN.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
NYZ032-033.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ038-082.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV/KL
SHORT TERM...HWJIV
LONG TERM...ELH
AVIATION...HWJIV/KL
HYDROLOGY...HWJIV/11/JPV
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1040 PM EST SUN JAN 3 2016
.DISCUSSION...
UPDATE...BACK EDGE OF THE RAIN SHIELD HAS BEGUN TO SHIFT S/E AND
RAINS WILL TAPER OFF ACROSS MOST OF EC FL OVERNIGHT. SO HAVE BEGUN
TO REDUCE RAIN CHANCES ACROSS THE FAR NORTH BUT NEAR 100 PERCENT
CHANCE WILL CONTINUE SOUTH OF ORLANDO INTO THE EARLY MORNING HOURS.
OTHERWISE NO SIGNIFICANT CHANGES TO CLOUDS/TEMPS.
(PREVIOUS) MID LEVEL SHORT WAVE TROUGH AXIS OVER THE CTRL GULF
COAST/NORTHERN GOMEX HAS BACKED THE H85-50 FLOW TO SWRLY NORTH OF
THE STALLED FRONT TO OUR SOUTH. ADDITIONAL FORCED ASCENT BEING
PROVIDED BY RR QUAD OF DEPARTING 110-130KT JET STREAK ACROSS THE SE
ATLC COASTAL STATES... WITH LF QUAD OF APPROACHING JET PUSHING
TOWARD THE N-CTRL/NE GOMEX.
TWO LARGE SW-NE ORIENTED SWATHS OF LIGHT-MDT RAIN HAVE OVERSPREAD
THE FAR NORTHERN AND CENTRAL-SOUTHERN CWA...WITH VERY LIGHT RETURNS
(SPRINKLES) ON EITHER SIDE OF THESE TWO FEATURES. OTRW...SKIES OVC
WITH TEMPS PRETTY MUCH RIGHT WHERE THEY WERE THIS MORNING.
THROUGH TONIGHT...
MID LEVEL TROUGH SLIDES E AND THEN TURNS ENE AS IT MOVES OFFSHORE
INTO THE ATLC. THIS WILL SPIN UP SURFACE LOW NE OF THE BAHAMAS ALONG
THE STALLED FRONT...AND BEGIN TO DRAG DRIER AIR INTO THE NRN-CTRL
CWA LATE TONIGHT. UNTIL THEN...PERIODS OF RAIN WILL CONTINUE FROM
LATE AFTERNOON WELL INTO THE EVENING/OVERNIGHT WITH ACTIVITY
SHIFTING E/S AND TAPERING OFF OR ENDING LATE. EVEN WITH ALL THE
CLOUDS/RAIN...TEMPS LOOK QUITE CHILLY TOWARD SUNRISE MONDAY WITH
MINS PROGGED TO DROP BELOW 50F N/W OF FORT DRUM-KMLB LINE. L-M40S NW
OF I-4...MAINLY L-M50S TO THE S/E.
MONDAY...COOL DAY ON TAP WITH TEMPS SLOWLY RISING INTO/THROUGH THE
50S AND ONLY REACHING THE L60S NORTH TO MID 60S SOUTH UNDER RAPIDLY
CLEARING SKIES (WITH SOME LINGERING HIGH CLOUDS) AND A NW BREEZE OF
10-15MPH. MAYBE A FEW LINGERING SPRINKLES OVER THE FAR SOUTH IN THE
MORNING...BUT JUST ABOUT ALL THE PRECIP WILL BE LONG GONE BY THEN.
&&
.AVIATION...IFR CIGS HAVE BEGUN TO LIFT SO HAVE LARGELY REMOVED THEM
FROM PREVAILING CONDS BUT KEPT A TEMPO THROUGH 06Z. OCNL MVFR VSBYS
IN -RABR WITH SPOTTY IFR NEAR 2SM IN MODERATE RAIN. CONDITIONS TO
GRADUALLY IMPROVE FROM N/W TO S/E STARTING ABOUT 06Z. LOWER CIGS
CLEARING OUT OF MLB-SUA 12Z-16Z.
&&
.MARINE...
NO SIGNIFICANT CHANGES TO CURRENT COASTAL WATERS FCST.
TONIGHT/MON...12Z NWPS LOOKED TOO HIGH GIVEN THE FCST WINDS A LITTLE
EITHER SIDE OF 20KT...SO WENT WITH A BLEND WHICH KEPT PEAK SEAS
AROUND 7FT THRU MONDAY AFTERNOON...WITH A BRIEF PERIOD OF 7-8FT SEAS
IN THE GULF STREAM OVERNIGHT. WINDS/SEAS WILL AT BEST BARELY MEET
SCA CRITERIA OVER THE OUTER PORTION OF THE 0-20NM LEGS THROUGH
OVERNIGHT...BUT GIVEN THE SHORT PERIOD CHOP AND INCREASING TREND IN
WINDS FCST JUST BEYOND THE SHORT RANGE...WILL LEAVE IT IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 46 62 49 62 / 90 0 10 20
MCO 45 64 46 66 / 100 0 0 10
MLB 48 64 55 67 / 100 10 10 20
VRB 52 64 56 69 / 100 10 10 20
LEE 42 63 42 64 / 90 0 0 10
SFB 43 63 44 64 / 90 0 0 10
ORL 46 63 46 66 / 100 0 0 10
FPR 53 64 56 69 / 100 10 10 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST WEDNESDAY FOR FLAGLER BEACH
TO VOLUSIA-BREVARD COUNTY LINE 0-20 NM-FLAGLER BEACH TO
VOLUSIA-BREVARD COUNTY LINE 20-60 NM-VOLUSIA-BREVARD COUNTY
LINE TO SEBASTIAN INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE
TO SEBASTIAN INLET 20-60 NM.
SMALL CRAFT ADVISORY UNTIL 4 AM EST WEDNESDAY FOR SEBASTIAN
INLET TO JUPITER INLET 0-20 NM-SEBASTIAN INLET TO JUPITER
INLET 20-60 NM.
&&
$$
KELLY/SEDLOCK
AREA FORECAST DISCUSSION
NWS MIAMI FL
1251 AM EST SAT JAN 2 2016
.AVIATION...SHOWERS LINGERING ACROSS EAST COAST TAF SITES FROM
KOPF NORTHWARDS WITH A FEW MORE MOVING INTO THE GULF COAST SOUTH
OF KAPF/KMKY. EAST COAST ACTIVITY PROGGED TO LINGER A FEW MORE
HOURS BEFORE PUSHING OFFSHORE GENERALLY AFTER 09Z. EXTENSIVE IFR
FOG/STRATUS DECK OVER CENTRAL FL OOZING DOWN WITH FRONT LIKELY
REACHING INTO KAPF BY 08Z AND KPBI AROUND 10Z, AND POSSIBLY INTO
KFXE/KFLL. PRIEPS SHOW DECK IS NOT TOO THICK, SO SHOULD BE ABLE TO
LIFT BY LATE MORNING WITH CIGS BECOMING VFR. WINDS SHIFTING NNW
OVERNIGHT, AND NNE ALONG EAST COAST LATE TOMORROW AFTERNOON. A FEW
SHOWERS AT TIMES AS FRONT SETTLES OVER REGION. /ALM
&&
.PREV DISCUSSION... /ISSUED 801 PM EST FRI JAN 1 2016/
UPDATE...NOT MUCH CHANGE TO THE FORECAST THIS EVENING. MAINLY
ADJUST THE WEATHER TO REFLECT CURRENT CONDITIONS. SOME SHOWER
ACTIVITY IS ONGOING IN THE INTERIOR. THE HRRR IS NOT DOING WELL
WITH THIS, AS IT IS COMPLETELY MISSING IT. HOWEVER, THE SYNOPTIC
MODELS ARE SHOWING PERHAPS A WEAK TROUGH MOVING ACROSS THE AREA,
HELPING TO SUPPORT THESE SHOWERS. THEY SHOULD COME TO AN END IN A
FEW HOURS. THEY ARE LIGHT, WITH RADAR ESTIMATES AROUND A QUARTER
INCH OR SO AN HOUR, SO NO SIGNIFICANT IMPACT AT THIS TIME.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
922 AM EST SAT JAN 2 2016
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 229 AM EST SAT JAN 2 2016
AN UPPER LEVEL SYSTEM COULD BRING SOME LIGHT SNOW TO PARTS OF THE
AREA SUNDAY NIGHT INTO MONDAY. A STRONGER SYSTEM COULD BRING RAIN
LATE NEXT WEEK. TEMPERATURES WILL REMAIN BELOW AVERAGE UNTIL THE
LATTER HALF OF NEXT WEEK.
&&
.NEAR TERM.../TODAY/
ISSUED AT 229 AM EST SAT JAN 2 2016
A WEAK SURFACE TROUGH WILL MOVE ACROSS THE AREA TODAY. SOME LOWER
LEVEL CLOUDS /ACROSS NORTHERN ILLINOIS AT THE MOMENT/ COULD SKIRT
THE NORTHERN PORTION OF THE FORECAST AREA TODAY...AND SOME MODELS
SUCH AS THE RUC INDICATE THE POTENTIAL FOR SOME ADDITIONAL CLOUDS TO
DEVELOP NORTHEAST.
THUS WILL GO BECOMING PARTLY CLOUDY NORTH BUT KEEP SKIES MOSTLY
SUNNY SOUTH.
MAV MOS HAS BEEN RUNNING WARM LATELY WITH HIGH TEMPERATURES...SO
STAYED CLOSER TO A MODEL BLEND.
&&
.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 229 AM EST SAT JAN 2 2016
FOCUS IS ON ANY CHANCES FOR SNOW...AS WELL AS SKY COVER. MODELS ARE
CLOSE ENOUGH THAT A BLEND WAS USED.
MOSTLY CLEAR SKIES WILL GIVE WAY TO SOME CLOUDS ACROSS NORTHERN
SECTIONS OF THE AREA DURING THE NIGHT AS A COLD FRONT APPROACHES.
THE FRONT WILL THEN MOVE THROUGH THE AREA EARLY SUNDAY. AS COLD
ADVECTION BEGINS EXPECT CLOUDS TO INCREASE DURING THE DAY WITH
PARTLY TO MOSTLY CLOUDY SKIES COMMON BY LATER SUNDAY AFTERNOON.
SUNDAY NIGHT INTO THE FIRST HALF OF MONDAY ADDITIONAL UPPER ENERGY
WILL MOVE INTO THE NORTHEASTERN PORTIONS OF THE AREA AS A LARGE
UPPER TROUGH SETTLES INTO THE NORTHEASTERN USA. THIS ENERGY ALONG
WITH THE CONTINUED COLD ADVECTION WILL LEAD TO A CHANCE FOR A FEW
SNOW SHOWERS OR FLURRIES ACROSS THE NORTHEAST HALF OF THE AREA.
DRIER AIR AND HIGH PRESSURE WILL THEN WORK IN AND END SNOWFALL
CHANCES AND EVEN ALLOW SOME CLEARING OF THE SKIES BY TUESDAY.
STUCK WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 230 AM EST SAT JAN 2 2016
OPERATIONAL MODELS AND ENSEMBLE MEANS AGREE THAT AN UPPER RIDGE OVER
THE AREA WILL KEEP IT DRY THROUGH WEDNESDAY. WOULD NOT COMPLETELY
RULE OUT A SHOWER OR TWO ON WEDNESDAY NIGHT INTO THURSDAY AS A WEAK
SOUTHWESTERLY UPPER WAVE MOVES THROUGH THE MEAN RIDGE. HOWEVER...VERY
MID AND LOWER LEVELS...PER MODEL RH TIME SECTIONS...FAVOR KEEPING IT
DRY THROUGH THURSDAY. THEN...A STRONGER SYSTEM WILL APPROACH THE
AREA FROM THE SOUTHWEST LATE FRIDAY. THIS SYSTEM WILL COMBINE WITH
SOUTHERLY FLOW AROUND AN EAST COAST HIGH AND RESULT IN INCREASING
MOISTURE AND FORCING AND THE RETURN OF PRECIPITATION BY THURSDAY
NIGHT. ALTHOUGH BUFKIT SUGGESTS THURSDAY NIGHT SHOULD BE MOSTLY
RAIN...WITH SLIGHTLY SUB-FREEZING OVERNIGHT LOWS FROM THE REGIONAL
BLEND...WENT WITH RAIN AND SNOW CHANCES THURSDAY NIGHT WITH JUST
RAIN CHANCES ON FRIDAY. DESPITE THE SNOW MENTION...NOT LOOKING
OPTIMISTIC FOR SNOW ENTHUASISTS REGARDING ACCUMULATION UNTIL AT
LEAST LATE NEXT WEEKEND OR EARLY NEXT WEEK. RAIN WILL BE THE MAIN
FOCUS THROUGH NEXT SATURDAY.
TEMPERATURES WILL BE WARMING MIDWEEK AS SOUTHERLY FLOW COMMENCES
ON THE BACK SIDE OF THE EAST COAST HIGH. REGIONAL BLEND HIGHS IN THE
UPPER 20S AND MID 30S ON TUESDAY AND UPPER 30S AND MID 40S BY
THURSDAY REFLECT THIS. NORMAL HIGHS THIS TIME OF YEAR ARE IN THE MID
30S.
&&
.AVIATION /DISCUSSION FOR THE 02/1500Z KIND TAF UPDATE/...
ISSUED AT 922 AM EST SAT JAN 2 2016
MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.
PREVIOUS AVIATION DISCUSSION FOLLOWS...
HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE THROUGH THE TAF
PERIOD. IN FACT...MODEL RH TIME SECTIONS AND SATELLITE SUGGEST CLEAR
SKIES THROUGH AT LEAST 09Z MONDAY. STRATOCU TO INCREASE FROM THE
NORTHWEST EARLY MONDAY AHEAD OF AN UPPER WAVE. THE STRATOCU SHOULD
REACH LAF NEAR 12Z. FOR NOW...WILL JUST BRING IN BROKEN 3500 FOOT
DECK THERE AT 09Z AND AT IND AFTER 12Z.
WINDS WILL BE FROM THE WEST AND SOUTHWEST 8 TO 12Z KNOTS TODAY AND
10 KNOTS OR LESS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....MK
AVIATION...MK/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
510 AM EST SAT JAN 2 2016
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 229 AM EST SAT JAN 2 2016
AN UPPER LEVEL SYSTEM COULD BRING SOME LIGHT SNOW TO PARTS OF THE
AREA SUNDAY NIGHT INTO MONDAY. A STRONGER SYSTEM COULD BRING RAIN
LATE NEXT WEEK. TEMPERATURES WILL REMAIN BELOW AVERAGE UNTIL THE
LATTER HALF OF NEXT WEEK.
&&
.NEAR TERM.../TODAY/
ISSUED AT 229 AM EST SAT JAN 2 2016
A WEAK SURFACE TROUGH WILL MOVE ACROSS THE AREA TODAY. SOME LOWER
LEVEL CLOUDS /ACROSS NORTHERN ILLINOIS AT THE MOMENT/ COULD SKIRT
THE NORTHERN PORTION OF THE FORECAST AREA TODAY...AND SOME MODELS
SUCH AS THE RUC INDICATE THE POTENTIAL FOR SOME ADDITIONAL CLOUDS TO
DEVELOP NORTHEAST.
THUS WILL GO BECOMING PARTLY CLOUDY NORTH BUT KEEP SKIES MOSTLY
SUNNY SOUTH.
MAV MOS HAS BEEN RUNNING WARM LATELY WITH HIGH TEMPERATURES...SO
STAYED CLOSER TO A MODEL BLEND.
&&
.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 229 AM EST SAT JAN 2 2016
FOCUS IS ON ANY CHANCES FOR SNOW...AS WELL AS SKY COVER. MODELS ARE
CLOSE ENOUGH THAT A BLEND WAS USED.
MOSTLY CLEAR SKIES WILL GIVE WAY TO SOME CLOUDS ACROSS NORTHERN
SECTIONS OF THE AREA DURING THE NIGHT AS A COLD FRONT APPROACHES.
THE FRONT WILL THEN MOVE THROUGH THE AREA EARLY SUNDAY. AS COLD
ADVECTION BEGINS EXPECT CLOUDS TO INCREASE DURING THE DAY WITH
PARTLY TO MOSTLY CLOUDY SKIES COMMON BY LATER SUNDAY AFTERNOON.
SUNDAY NIGHT INTO THE FIRST HALF OF MONDAY ADDITIONAL UPPER ENERGY
WILL MOVE INTO THE NORTHEASTERN PORTIONS OF THE AREA AS A LARGE
UPPER TROUGH SETTLES INTO THE NORTHEASTERN USA. THIS ENERGY ALONG
WITH THE CONTINUED COLD ADVECTION WILL LEAD TO A CHANCE FOR A FEW
SNOW SHOWERS OR FLURRIES ACROSS THE NORTHEAST HALF OF THE AREA.
DRIER AIR AND HIGH PRESSURE WILL THEN WORK IN AND END SNOWFALL
CHANCES AND EVEN ALLOW SOME CLEARING OF THE SKIES BY TUESDAY.
STUCK WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 230 AM EST SAT JAN 2 2016
OPERATIONAL MODELS AND ENSEMBLE MEANS AGREE THAT AN UPPER RIDGE OVER
THE AREA WILL KEEP IT DRY THROUGH WEDNESDAY. WOULD NOT COMPLETELY
RULE OUT A SHOWER OR TWO ON WEDNESDAY NIGHT INTO THURSDAY AS A WEAK
SOUTHWESTERLY UPPER WAVE MOVES THROUGH THE MEAN RIDGE. HOWEVER...VERY
MID AND LOWER LEVELS...PER MODEL RH TIME SECTIONS...FAVOR KEEPING IT
DRY THROUGH THURSDAY. THEN...A STRONGER SYSTEM WILL APPROACH THE
AREA FROM THE SOUTHWEST LATE FRIDAY. THIS SYSTEM WILL COMBINE WITH
SOUTHERLY FLOW AROUND AN EAST COAST HIGH AND RESULT IN INCREASING
MOISTURE AND FORCING AND THE RETURN OF PRECIPITATION BY THURSDAY
NIGHT. ALTHOUGH BUFKIT SUGGESTS THURSDAY NIGHT SHOULD BE MOSTLY
RAIN...WITH SLIGHTLY SUB-FREEZING OVERNIGHT LOWS FROM THE REGIONAL
BLEND...WENT WITH RAIN AND SNOW CHANCES THURSDAY NIGHT WITH JUST
RAIN CHANCES ON FRIDAY. DESPITE THE SNOW MENTION...NOT LOOKING
OPTIMISTIC FOR SNOW ENTHUASISTS REGARDING ACCUMULATION UNTIL AT
LEAST LATE NEXT WEEKEND OR EARLY NEXT WEEK. RAIN WILL BE THE MAIN
FOCUS THROUGH NEXT SATURDAY.
TEMPERATURES WILL BE WARMING MIDWEEK AS SOUTHERLY FLOW COMMENCES
ON THE BACK SIDE OF THE EAST COAST HIGH. REGIONAL BLEND HIGHS IN THE
UPPER 20S AND MID 30S ON TUESDAY AND UPPER 30S AND MID 40S BY
THURSDAY REFLECT THIS. NORMAL HIGHS THIS TIME OF YEAR ARE IN THE MID
30S.
&&
.AVIATION /DISCUSSION FOR THE 02/1200Z TAF ISSUANCE/...
ISSUED AT 510 AM EST SAT JAN 2 2016
HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE THROUGH THE TAF
PERIOD. IN FACT...MODEL RH TIME SECTIONS AND SATELLITE SUGGEST CLEAR
SKIES THROUGH AT LEAST 09Z MONDAY. STRATOCU TO INCREASE FROM THE
NORTHWEST EARLY MONDAY AHEAD OF AN UPPER WAVE. THE STRATOCU SHOULD
REACH LAF NEAR 12Z. FOR NOW...WILL JUST BRING IN BROKEN 3500 FOOT
DECK THERE AT 09Z AND AT IND AFTER 12Z.
WINDS WILL BE FROM THE WEST AND SOUTHWEST 8 TO 12Z KNOTS TODAY AND
10 KNOTS OR LESS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....MK
AVIATION...MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
330 AM EST SAT JAN 2 2016
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 229 AM EST SAT JAN 2 2016
AN UPPER LEVEL SYSTEM COULD BRING SOME LIGHT SNOW TO PARTS OF THE
AREA SUNDAY NIGHT INTO MONDAY. A STRONGER SYSTEM COULD BRING RAIN
LATE NEXT WEEK. TEMPERATURES WILL REMAIN BELOW AVERAGE UNTIL THE
LATTER HALF OF NEXT WEEK.
&&
.NEAR TERM.../TODAY/
ISSUED AT 229 AM EST SAT JAN 2 2016
A WEAK SURFACE TROUGH WILL MOVE ACROSS THE AREA TODAY. SOME LOWER
LEVEL CLOUDS /ACROSS NORTHERN ILLINOIS AT THE MOMENT/ COULD SKIRT
THE NORTHERN PORTION OF THE FORECAST AREA TODAY...AND SOME MODELS
SUCH AS THE RUC INDICATE THE POTENTIAL FOR SOME ADDITIONAL CLOUDS TO
DEVELOP NORTHEAST.
THUS WILL GO BECOMING PARTLY CLOUDY NORTH BUT KEEP SKIES MOSTLY
SUNNY SOUTH.
MAV MOS HAS BEEN RUNNING WARM LATELY WITH HIGH TEMPERATURES...SO
STAYED CLOSER TO A MODEL BLEND.
&&
.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 229 AM EST SAT JAN 2 2016
FOCUS IS ON ANY CHANCES FOR SNOW...AS WELL AS SKY COVER. MODELS ARE
CLOSE ENOUGH THAT A BLEND WAS USED.
MOSTLY CLEAR SKIES WILL GIVE WAY TO SOME CLOUDS ACROSS NORTHERN
SECTIONS OF THE AREA DURING THE NIGHT AS A COLD FRONT APPROACHES.
THE FRONT WILL THEN MOVE THROUGH THE AREA EARLY SUNDAY. AS COLD
ADVECTION BEGINS EXPECT CLOUDS TO INCREASE DURING THE DAY WITH
PARTLY TO MOSTLY CLOUDY SKIES COMMON BY LATER SUNDAY AFTERNOON.
SUNDAY NIGHT INTO THE FIRST HALF OF MONDAY ADDITIONAL UPPER ENERGY
WILL MOVE INTO THE NORTHEASTERN PORTIONS OF THE AREA AS A LARGE
UPPER TROUGH SETTLES INTO THE NORTHEASTERN USA. THIS ENERGY ALONG
WITH THE CONTINUED COLD ADVECTION WILL LEAD TO A CHANCE FOR A FEW
SNOW SHOWERS OR FLURRIES ACROSS THE NORTHEAST HALF OF THE AREA.
DRIER AIR AND HIGH PRESSURE WILL THEN WORK IN AND END SNOWFALL
CHANCES AND EVEN ALLOW SOME CLEARING OF THE SKIES BY TUESDAY.
STUCK WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 230 AM EST SAT JAN 2 2016
OPERATIONAL MODELS AND ENSEMBLE MEANS AGREE THAT AN UPPER RIDGE OVER
THE AREA WILL KEEP IT DRY THROUGH WEDNESDAY. WOULD NOT COMPLETELY
RULE OUT A SHOWER OR TWO ON WEDNESDAY NIGHT INTO THURSDAY AS A WEAK
SOUTHWESTERLY UPPER WAVE MOVES THROUGH THE MEAN RIDGE. HOWEVER...VERY
MID AND LOWER LEVELS...PER MODEL RH TIME SECTIONS...FAVOR KEEPING IT
DRY THROUGH THURSDAY. THEN...A STRONGER SYSTEM WILL APPROACH THE
AREA FROM THE SOUTHWEST LATE FRIDAY. THIS SYSTEM WILL COMBINE WITH
SOUTHERLY FLOW AROUND AN EAST COAST HIGH AND RESULT IN INCREASING
MOISTURE AND FORCING AND THE RETURN OF PRECIPITATION BY THURSDAY
NIGHT. ALTHOUGH BUFKIT SUGGESTS THURSDAY NIGHT SHOULD BE MOSTLY
RAIN...WITH SLIGHTLY SUB-FREEZING OVERNIGHT LOWS FROM THE REGIONAL
BLEND...WENT WITH RAIN AND SNOW CHANCES THURSDAY NIGHT WITH JUST
RAIN CHANCES ON FRIDAY. DESPITE THE SNOW MENTION...NOT LOOKING
OPTIMISTIC FOR SNOW ENTHUASISTS REGARDING ACCUMULATION UNTIL AT
LEAST LATE NEXT WEEKEND OR EARLY NEXT WEEK. RAIN WILL BE THE MAIN
FOCUS THROUGH NEXT SATURDAY.
TEMPERATURES WILL BE WARMING MIDWEEK AS SOUTHERLY FLOW COMMENCES
ON THE BACK SIDE OF THE EAST COAST HIGH. REGIONAL BLEND HIGHS IN THE
UPPER 20S AND MID 30S ON TUESDAY AND UPPER 30S AND MID 40S BY
THURSDAY REFLECT THIS. NORMAL HIGHS THIS TIME OF YEAR ARE IN THE MID
30S.
&&
.AVIATION /DISCUSSION FOR THE 02/0900Z IND TAF UPDATE/...
ISSUED AT 330 AM EST SAT JAN 2 2016
VFR CONDITIONS TO CONTINUE WITH CLEAR SKIES. SOUTHWEST WINDS TO 10
KNOTS OR MORE WILL KEEP THE BOUNDARY LAYER MIXED AND PREVENT FOG.
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 1150 PM EST FRI JAN 1 2016
VFR THROUGH THE PERIOD.
MID CLOUDS POSSIBLE SOME AREAS EARLY ON...OTHERWISE MOSTLY CLEAR OVERNIGHT.
AN AREA OF MVFR CEILINGS OVER WISCONSIN WILL SPREAD SOUTHEAST INTO NORTHERN
INDIANA TOWARDS SUNRISE AS A WEAK UPPER TROUGH MOVES INTO THE GREAT
LAKES. MOST OF THESE CLOUDS SHOULD REMAIN JUST NORTHEAST OF KLAF
AND KIND...BUT WILL MENTION SCT025 THERE. OTHERWISE...MOSTLY CLEAR
KHUF AND KBMG SATURDAY AND SATURDAY NIGHT AND KIND AND KLAF AFTER
22Z AS DRIER AIR SPREADS IN.
WINDS WILL BE FROM THE WEST TO SOUTHWEST UP TO 10 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....MK
AVIATION...JH/MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
230 AM EST SAT JAN 2 2016
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 229 AM EST SAT JAN 2 2016
AN UPPER LEVEL SYSTEM COULD BRING SOME LIGHT SNOW TO PARTS OF THE
AREA SUNDAY NIGHT INTO MONDAY. A STRONGER SYSTEM COULD BRING RAIN
LATE NEXT WEEK. TEMPERATURES WILL REMAIN BELOW AVERAGE UNTIL THE
LATTER HALF OF NEXT WEEK.
&&
.NEAR TERM.../TODAY/
ISSUED AT 229 AM EST SAT JAN 2 2016
A WEAK SURFACE TROUGH WILL MOVE ACROSS THE AREA TODAY. SOME LOWER
LEVEL CLOUDS /ACROSS NORTHERN ILLINOIS AT THE MOMENT/ COULD SKIRT
THE NORTHERN PORTION OF THE FORECAST AREA TODAY...AND SOME MODELS
SUCH AS THE RUC INDICATE THE POTENTIAL FOR SOME ADDITIONAL CLOUDS TO
DEVELOP NORTHEAST.
THUS WILL GO BECOMING PARTLY CLOUDY NORTH BUT KEEP SKIES MOSTLY
SUNNY SOUTH.
MAV MOS HAS BEEN RUNNING WARM LATELY WITH HIGH TEMPERATURES...SO
STAYED CLOSER TO A MODEL BLEND.
&&
.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 229 AM EST SAT JAN 2 2016
FOCUS IS ON ANY CHANCES FOR SNOW...AS WELL AS SKY COVER. MODELS ARE
CLOSE ENOUGH THAT A BLEND WAS USED.
MOSTLY CLEAR SKIES WILL GIVE WAY TO SOME CLOUDS ACROSS NORTHERN
SECTIONS OF THE AREA DURING THE NIGHT AS A COLD FRONT APPROACHES.
THE FRONT WILL THEN MOVE THROUGH THE AREA EARLY SUNDAY. AS COLD
ADVECTION BEGINS EXPECT CLOUDS TO INCREASE DURING THE DAY WITH
PARTLY TO MOSTLY CLOUDY SKIES COMMON BY LATER SUNDAY AFTERNOON.
SUNDAY NIGHT INTO THE FIRST HALF OF MONDAY ADDITIONAL UPPER ENERGY
WILL MOVE INTO THE NORTHEASTERN PORTIONS OF THE AREA AS A LARGE
UPPER TROUGH SETTLES INTO THE NORTHEASTERN USA. THIS ENERGY ALONG
WITH THE CONTINUED COLD ADVECTION WILL LEAD TO A CHANCE FOR A FEW
SNOW SHOWERS OR FLURRIES ACROSS THE NORTHEAST HALF OF THE AREA.
DRIER AIR AND HIGH PRESSURE WILL THEN WORK IN AND END SNOWFALL
CHANCES AND EVEN ALLOW SOME CLEARING OF THE SKIES BY TUESDAY.
STUCK WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 230 AM EST SAT JAN 2 2016
OPERATIONAL MODELS AND ENSEMBLE MEANS AGREE THAT AN UPPER RIDGE OVER
THE AREA WILL KEEP IT DRY THROUGH WEDNESDAY. WOULD NOT COMPLETELY
RULE OUT A SHOWER OR TWO ON WEDNESDAY NIGHT INTO THURSDAY AS A WEAK
SOUTHWESTERLY UPPER WAVE MOVES THROUGH THE MEAN RIDGE. HOWEVER...VERY
MID AND LOWER LEVELS...PER MODEL RH TIME SECTIONS...FAVOR KEEPING IT
DRY THROUGH THURSDAY. THEN...A STRONGER SYSTEM WILL APPROACH THE
AREA FROM THE SOUTHWEST LATE FRIDAY. THIS SYSTEM WILL COMBINE WITH
SOUTHERLY FLOW AROUND AN EAST COAST HIGH AND RESULT IN INCREASING
MOISTURE AND FORCING AND THE RETURN OF PRECIPITATION BY THURSDAY
NIGHT. ALTHOUGH BUFKIT SUGGESTS THURSDAY NIGHT SHOULD BE MOSTLY
RAIN...WITH SLIGHTLY SUB-FREEZING OVERNIGHT LOWS FROM THE REGIONAL
BLEND...WENT WITH RAIN AND SNOW CHANCES THURSDAY NIGHT WITH JUST
RAIN CHANCES ON FRIDAY. DESPITE THE SNOW MENTION...NOT LOOKING
OPTIMISTIC FOR SNOW ENTHUASISTS REGARDING ACCUMULATION UNTIL AT
LEAST LATE NEXT WEEKEND OR EARLY NEXT WEEK. RAIN WILL BE THE MAIN
FOCUS THROUGH NEXT SATURDAY.
TEMPERATURES WILL BE WARMING MIDWEEK AS SOUTHERLY FLOW COMMENCES
ON THE BACK SIDE OF THE EAST COAST HIGH. REGIONAL BLEND HIGHS IN THE
UPPER 20S AND MID 30S ON TUESDAY AND UPPER 30S AND MID 40S BY
THURSDAY REFLECT THIS. NORMAL HIGHS THIS TIME OF YEAR ARE IN THE MID
30S.
&&
.AVIATION /DISCUSSION FOR THE 02/0600Z TAF ISSUANCE/...
ISSUED AT 1150 PM EST FRI JAN 1 2016
VFR THROUGH THE PERIOD.
MID CLOUDS POSSIBLE SOME AREAS EARLY ON...OTHERWISE MOSTLY CLEAR OVERNIGHT.
AN AREA OF MVFR CEILINGS OVER WISCONSIN WILL SPREAD SOUTHEAST INTO NORTHERN
INDIANA TOWARDS SUNRISE AS A WEAK UPPER TROUGH MOVES INTO THE GREAT LAKES.
MOST OF THESE CLOUDS SHOULD REMAIN JUST NORTHEAST OF KLAF AND KIND...BUT WILL
MENTION SCT025 THERE. OTHERWISE...MOSTLY CLEAR KHUF AND KBMG SATURDAY AND
SATURDAY NIGHT AND KIND AND KLAF AFTER 22Z AS DRIER AIR SPREADS IN.
WINDS WILL BE FROM THE WEST TO SOUTHWEST UP TO 10 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....MK
AVIATION...JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
229 AM EST SAT JAN 2 2016
.UPDATE...
THE SYNOPSIS...NEAR TERM...AND SHORT TERM SECTIONS HAVE BEEN
UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 229 AM EST SAT JAN 2 2016
AN UPPER LEVEL SYSTEM COULD BRING SOME LIGHT SNOW TO PARTS OF THE
AREA SUNDAY NIGHT INTO MONDAY. A STRONGER SYSTEM COULD BRING RAIN
LATE NEXT WEEK. TEMPERATURES WILL REMAIN BELOW AVERAGE UNTIL THE
LATTER HALF OF NEXT WEEK.
&&
.NEAR TERM.../TODAY/
ISSUED AT 229 AM EST SAT JAN 2 2016
A WEAK SURFACE TROUGH WILL MOVE ACROSS THE AREA TODAY. SOME LOWER
LEVEL CLOUDS /ACROSS NORTHERN ILLINOIS AT THE MOMENT/ COULD SKIRT
THE NORTHERN PORTION OF THE FORECAST AREA TODAY...AND SOME MODELS
SUCH AS THE RUC INDICATE THE POTENTIAL FOR SOME ADDITIONAL CLOUDS TO
DEVELOP NORTHEAST.
THUS WILL GO BECOMING PARTLY CLOUDY NORTH BUT KEEP SKIES MOSTLY
SUNNY SOUTH.
MAV MOS HAS BEEN RUNNING WARM LATELY WITH HIGH TEMPERATURES...SO
STAYED CLOSER TO A MODEL BLEND.
&&
.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 229 AM EST SAT JAN 2 2016
FOCUS IS ON ANY CHANCES FOR SNOW...AS WELL AS SKY COVER. MODELS ARE
CLOSE ENOUGH THAT A BLEND WAS USED.
MOSTLY CLEAR SKIES WILL GIVE WAY TO SOME CLOUDS ACROSS NORTHERN
SECTIONS OF THE AREA DURING THE NIGHT AS A COLD FRONT APPROACHES.
THE FRONT WILL THEN MOVE THROUGH THE AREA EARLY SUNDAY. AS COLD
ADVECTION BEGINS EXPECT CLOUDS TO INCREASE DURING THE DAY WITH
PARTLY TO MOSTLY CLOUDY SKIES COMMON BY LATER SUNDAY AFTERNOON.
SUNDAY NIGHT INTO THE FIRST HALF OF MONDAY ADDITIONAL UPPER ENERGY
WILL MOVE INTO THE NORTHEASTERN PORTIONS OF THE AREA AS A LARGE
UPPER TROUGH SETTLES INTO THE NORTHEASTERN USA. THIS ENERGY ALONG
WITH THE CONTINUED COLD ADVECTION WILL LEAD TO A CHANCE FOR A FEW
SNOW SHOWERS OR FLURRIES ACROSS THE NORTHEAST HALF OF THE AREA.
DRIER AIR AND HIGH PRESSURE WILL THEN WORK IN AND END SNOWFALL
CHANCES AND EVEN ALLOW SOME CLEARING OF THE SKIES BY TUESDAY.
STUCK WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE PERIOD.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 243 PM EST FRI JAN 1 2016
RIDGING ALOFT AND AT THE SURFACE WILL STRENGTHEN OVER THE REGION
EARLY IN THE EXTENDED PERIOD...KEEPING CONDITIONS DRY THROUGH
THURSDAY. THE PATTERN WILL CHANGE BY THURSDAY NIGHT THOUGH AS A LOW
PRESSURE SYSTEM DIGS INTO THE DESERT SOUTHWEST. RAIN SHOWERS WILL
BE POSSIBLE ON THURSDAY NIGHT AS THE RIDGING ALOFT BREAKS DOWN AND A
FRONTAL BOUNDARY APPROACHES CENTRAL INDIANA AT THE SURFACE.
TEMPERATURES WILL START OUT NEAR NORMAL FOR THE FIRST HALF OF THE
LONG TERM PERIOD...THEN INCREASE SLIGHTLY BY WEDNESDAY AND THURSDAY
WITH WARM ADVECTION.
&&
.AVIATION /DISCUSSION FOR THE 02/0600Z TAF ISSUANCE/...
ISSUED AT 1150 PM EST FRI JAN 1 2016
VFR THROUGH THE PERIOD.
MID CLOUDS POSSIBLE SOME AREAS EARLY ON...OTHERWISE MOSTLY CLEAR OVERNIGHT.
AN AREA OF MVFR CEILINGS OVER WISCONSIN WILL SPREAD SOUTHEAST INTO NORTHERN
INDIANA TOWARDS SUNRISE AS A WEAK UPPER TROUGH MOVES INTO THE GREAT LAKES.
MOST OF THESE CLOUDS SHOULD REMAIN JUST NORTHEAST OF KLAF AND KIND...BUT WILL
MENTION SCT025 THERE. OTHERWISE...MOSTLY CLEAR KHUF AND KBMG SATURDAY AND
SATURDAY NIGHT AND KIND AND KLAF AFTER 22Z AS DRIER AIR SPREADS IN.
WINDS WILL BE FROM THE WEST TO SOUTHWEST UP TO 10 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....TDUD
AVIATION...JH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
930 PM CST SUN JAN 3 2016
.UPDATE...
ISSUED AT 927 PM CST SUN JAN 3 2016
HAVE HIT THE FOG WORDING A BIT HARDER OVER THE NW HALF OF THE
FORECAST AREA OVERNIGHT. LATEST RAP AND HRRR BOTH HAVE A GOOD
HANDLE ON CURRENT LOW VISIBILITIES THROUGH THE SIOUXLAND AREA AND
GRADUALLY EXPANDED THE FOG SOUTH AND EAST WITH TIME. NO HEADLINE
YET...BUT POSSIBILITY WILL CERTAINLY NEED TO BE MONITORED IF NW
OBS START DROPPING.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 320 PM CST SUN JAN 3 2016
BROAD AREA OF STRATUS STILL IN PLACE ACROSS IOWA THOUGH IT HAS BEEN
AGGRESSIVELY DISSIPATING OVER PORTIONS OF WEST CENTRAL MN THIS
AFTERNOON. HAVE KEPT MOSTLY CLOUDY CONDITIONS IN PLACE THROUGH
TONIGHT. WITH THE RESIDUAL MOISTURE IN PLACE...THE STRATUS SHOULD
START TO EXPAND BACK WEST SHORTLY AFTER MIDNIGHT OR MAY VERY WELL
FILL IN AS FOG AS HIGH PRESSURE BEGINS TO SETTLE OVER THE LOW LEVEL
MOISTURE. HAVE KEPT TEMPERATURES ABOVE GUIDANCE WITH THE EXPECTED
CLOUD COVER. HAVE ALSO BROUGHT FOG MENTION OVER WESTERN PORTIONS OF
THE FORECAST AREA. SHOULD CLEARING POCKETS DEVELOP...ADDITIONAL
AREAS OF FOG WILL BE POSSIBLE IN ADDITION TO LOCALIZED COLDER
TEMPERATURES.
.LONG TERM /MONDAY THROUGH SUNDAY/...
ISSUED AT 320 PM CST SUN JAN 3 2016
IN THE NEAR FUTURE THE STRATUS HAVE LITTLE PLACE TO GO. DESPITE
THE RIDGE MOVING OVER THE REGION BY MONDAY AFTERNOON THE STRATUS
LOOK TO EXPAND ENOUGH OVERNIGHT TONIGHT THAT IT WILL LIKELY TAKE
LONGER FOR THE CLOUDS TO DISSIPATE TOMORROW GIVEN THE TIME OF YEAR.
FOR NOW...WILL GO WITH PERSISTENCE AS EVEN THE MESOSCALE MODELS
ARE HOLDING ONTO SOME CLOUDS INTO MONDAY AFTERNOON. HIGHS MONDAY
WILL BE HELD BACK WITH THE CLOUD COVER...SIMILAR TO TODAY. THE
NEXT CHALLENGE WILL BE THE ARRIVAL OF THE WEAK SYSTEM ON WEDNESDAY.
A MINOR WAVE WILL APPROACH THE REGION WEDNESDAY WITH INCREASING
MOISTURE THROUGH H700. AS WARMER AIR ALSO LIFTS NORTH WITH THE
ACCOMPANYING SHORTWAVES LIFT...SOME LIGHT PRECIPITATION BEGINNING
AS SNOW WILL MOVE ACROSS THE REGION THROUGH MORNING THEN MIX IN
WITH SOME LIGHT RAIN OR LIGHT DRIZZLE LATER IN THE AFTERNOON.
DURING WED NIGHT THERE MAY BE A LIGHT MIX OF DRIZZLE OR FREEZING
DRIZZLE BUT FOR NOW HAVE NOT DEFINED THE THREAT IN GREAT DETAIL.
UNCERTAINTY OF THE THERMAL PROFILES FOR THIS EVENT IS MAKING PTYPE
FORECAST DIFFICULT. THIS TREND IS CONTINUING INTO THURSDAY AND
THURSDAY NIGHT WITH THE ARRIVAL OF THE MAIN SYSTEM...THOUGH THE
GENERAL TRENDS ARE FOR THE WARMER AIR TO OVERTAKE THE COLD AIR
ENOUGH TO CHANGE MUCH OF THE PRECIPITATION TO RAIN. BY LATE FRIDAY
AS THE SECOND SYSTEM BEGINS TO SHIFT EAST OF THE AREA...THE
PRECIPITATION WILL CHANGE BACK TO SNOW WITH SOME LIGHT ACCUMULATIONS
POSSIBLE AS THE LOW DEPARTS FRIDAY NIGHT INTO SATURDAY. HIGHS
THROUGH THE BULK OF THE WEEK WILL REMAIN MILDER THAN NORMAL ONCE
TUESDAY ROLLS AROUND. MOST AREAS WILL REACH THE 30S WITH THE
CENTRAL AND SOUTH THE UPPER 30S TO NEARING 40. LOWS WILL DROP INTO
THE 20S AND 30S. TOWARD THE END OF FRIDAY A THIRD SHORTWAVE WILL
TRACK ACROSS THE SOUTHERN US. CURRENTLY IT APPEARS THAT THE WAVE
WILL REMAIN FAR ENOUGH SOUTH THAT IT WILL NOT PHASE WITH THE
DIGGING NORTHERN STREAM. CURRENTLY THE EURO IS FARTHER WEST/NORTH
WITH THE TRACK OF THIS SYSTEM WHILE THE GFS REMAINS ALONG THE GULF
COAST. THOUGH IT LIKELY WONT BE A PROBLEM FOR OUR AREA...WILL
MONITOR FOR ANY POSSIBLE PHASING AND FARTHER NORTHWEST TRACK NEXT
WEEKEND. MEANWHILE...THERE CONTINUES A SIGNAL FOR MUCH COLDER
WEATHER BEYOND DAY7 AS AN ARCTIC INTRUSION BUILDS SOUTHEAST INTO
THE CENTRAL PLAINS. BY SUNDAY TEMPERATURES BEGIN TO SLIDE WITH
TEENS/20S FOR HIGHS AND LOWS IN THE SINGLE DIGITS DAY7 NIGHT.
&&
.AVIATION...04/00Z
ISSUED AT 604 PM CST SUN JAN 3 2016
PRIMARY CONCERNS WILL BE FOG AND VSBY TRENDS INTO MON. WIDESPREAD
MVFR CIGS REMAIN IN PLACE ACROSS IA BUT A SMALL WEDGE OF CLEARING
IS ADVANCING SLOWLY SWD TOWARD IA. HAVE CLEARED OUT THE NERN SITES
FOR A PERIOD...BUT BELIEVE THE PREDOMINATE TREND WILL BE AT LEAST
MVFR STRATUS. CIGS COULD ALSO DROP TO IFR FOR A PERIOD...AND IFR
OR LESS CONDITIONS DUE TO VSBYS WILL HAVE TO BE MONITORED IF THE
SIOUXLAND FOG SPREADS BACK TO THE EAST. CONFIDENCE WAS NOT THERE
FOR MUCH IFR MENTION AS OF YET...BUT IS CERTAINLY POSSIBLE AND
NEEDS TO BE WATCHED.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMALL
SHORT TERM...DONAVON
LONG TERM...REV
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
258 PM CST SAT JAN 2 2016
.SHORT TERM /TONIGHT/...
ISSUED AT 256 PM CST SAT JAN 2 2016
BREEZY WESTERLY WINDS WILL SWITCH FROM THE NORTHWEST OVERNIGHT AS A
BOUNDARY PASSES THROUGH THE STATE. A BROAD STRATUS DECK OVER
ONTARIO THROUGH MUCH OF MANITOBA WILL DROP SOUTH ALONG WITH THE
BOUNDARY OVERNIGHT. STILL SOME UNCERTAINTY ON HOW MUCH AREAL
COVERAGE THE STRATUS WILL HAVE ONCE IT ARRIVES. THE LATEST RAP 925
MB RH ANALYSIS MATCHES WELL WITH CURRENT PLACEMENT OF THE STRATUS.
USING THIS RH AND THE 925 MB WIND AS THE STEERING FLOW WIND...THE
STRATUS SHOULD BE NEAR HIGHWAY 20 BY 12Z FROM NORTH CENTRAL TO
NORTHEAST IOWA. THE CURRENT MOVEMENT IS SOUTH AT 38 KTS...WHICH
WOULD PLACE TIME OF ARRIVAL OVER NORTHERN IOWA AROUND 06Z. PRIMARY
IMPACT ON TIME OF ARRIVAL IS AVIATION CONCERNS BUT ALSO OVERNIGHT
LOW TEMPERATURES. HAVE KEPT THE NORTH A BIT WARMER BASED ON ARRIVAL
OF CLOUD COVER. NO FLURRIES ADDED AT THIS TIME WITH THE MOIST LAYER
TEMPERATURES WARMER THAN THE PREFERRED DENDRITIC GROWTH ZONE.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 256 PM CST SAT JAN 2 2016
CONTINUED QUIET WEATHER FOR THE NEXT SEVERAL DAYS...THOUGH WITH THE
COLD FRONT AND UPPER LEVEL TROUGH APPROACHING OUR AREA BY TOMORROW
MORNING...STRATUS SHIELD NOW OVER NORTHERN MINNESOTA WILL EVENTUALLY
BRING SIGNIFICANT CLOUD COVER TO THE REGION SUNDAY THROUGH EARLY
MONDAY. ONCE THE UPPER LEVEL RIDGE BEGINS TO PULL EAST...
ANTICYCLONIC ROTATION AND SUBSIDENCE WILL ACT TO CLEAR SKIES BY
MONDAY AFTERNOON MOST AREAS. TEMPERATURES WILL BE HELD DOWN A BIT
MORE OVER THE NORTHEAST HALF OF THE AREA ON SUNDAY...WHILE THE WEST
MAY SEE ENOUGH SUNSHINE FOR A FEW DEGREES WARMER TEMPERATURES. BY
LATE SUNDAY NIGHT CLOUDS WILL SLOWLY ERODE...WITH COLDER OVERNIGHT
LOWS IN THE WEST. BY MONDAY AFTERNOON THE RIDGE IS BEGINNING TO
BUILD EAST. EARLIER FORECASTS SUGGESTED THE TROUGH TO HOLD ON LONGER
OVER THE GREAT LAKES...BUT ALL MEDIUM RANGE MODELS HAVE COME AROUND
TO A SLIGHTLY MORE PROGRESSIVE SOLUTION. THE BEST MODEL EARLIER WAS
THE GFS...THOUGH IT INITIALLY HAD THE COLD AIR MOVING OUT TOO FAST
WHILE THE GEM/EURO WERE BOTH TOO SLOW. TEMPERATURES WILL ALREADY BE
WARMING UP LATE MONDAY EVENING ALOFT...SO MINS OVER THE WEST WILL BE
MILDER. ACROSS THE EAST...LIGHTER SFC WINDS WILL STILL ALLOW FOR
SOME LOCATIONS TO REACH THE SINGLE DIGITS TUESDAY MORNING.
THE MAIN WEATHER MAKER WILL CONTINUES TO BE THE MID TO LATE WEEK
SYSTEM PROGGED TO REACH THE CALIFORNIA COAST TUESDAY NIGHT. A WEAKER
LESS AMPLIFIED SHORT WAVE WILL TRACK INTO THE CENTRAL PLAINS ALREADY
ON WEDNESDAY. WITH LITTLE MOISTURE RETURN AND SOME LIFT DUE TO BOTH
THE WAVE AND WARM AIR ADVECTION...EXPECTING SOME VERY LIGHT
PRECIPITATION OR A MIX OF DRIZZLE/LIGHT SNOW TO OCCUR DURING THE
DAYTIME HOURS. GFS BUFR SOUNDINGS SUGGEST A RATHER SHALLOW LAYER
OF MOISTURE INITIALLY...WITH LITTLE ICE INTRODUCTION ON WEDNESDAY.
THE MORE DYNAMIC SYSTEM IS EXPECTED TO REACH THE REGION ON
THURSDAY INTO FRIDAY...BEGINNING AS A MIX OF PRECIPITATION
THURSDAY AND FRIDAY...CHANGING TO ALL SNOW BY FRIDAY NIGHT AND
LINGERING LIGHT SNOW ON SATURDAY. TEMPERATURES OVER THE SOUTHEAST
ARE EXPECTED TO WARM TO ABOVE THE FREEZING MARK INTO THE MID 30S
FOR WEDNESDAY/THURSDAY/FRIDAY...SO MUCH OF THE PRECIPITATION MAY
EITHER END UP AS A MIX OR PLAIN RAIN. OVERNIGHT AND EARLY MORNING
MAY SEE THE PRECIP SWITCH BACK OVER TO A FROZEN MIX. WITH GULF
MOISTURE MORE AVAILABLE BY WEEKS END...SOME ACCUMULATING SNOW
SHOULD OCCUR ON THE BACKSIDE OF THE SYSTEM AS IT DEPARTS FRIDAY
EVENING INTO SATURDAY. AT THIS TIME AMOUNTS ARE EXPECTED TO BE ON
THE LIGHT SIDE.
AS MENTIONED YESTERDAY COLD AIR REALLY DOES NOT REACH THE SYSTEM
FAST ENOUGH FOR STRONGER AMPLIFICATION PRIOR TO THE STORMS
DEPARTURE. AS WE GET CLOSER TO THE EVENT...MORE DETAILS WILL BE
AVAILABLE FOR PRECIPITATION TYPES THURSDAY INTO FRIDAY. ONCE THE
SYSTEM DEPARTS THE REGION LATE ON SATURDAY COLDER AIR WILL BEGIN
DRIVING SOUTH INTO THE NORTHERN PLAINS AND EVENTUALLY IOWA.
CURRENTLY...THE CLIMATE PREDICTION CENTERS 8/14 DAY OUTLOOK IS FOR
COLDER THAN NORMAL TEMPERATURES...AND JUDGING BY THE UPSTREAM
AIRMASS AND SOME CONSISTENCY OVER THE PAST TWO MEDIUM RANGE MODEL
RUNS OF THE EURO/GFS...THIS LOOKS LIKE A GOOD BET FOR NOW.
&&
.AVIATION...02/18Z
ISSUED AT 1137 AM CST SAT JAN 2 2016
VFR CONDITIONS THROUGH MUCH OF TONIGHT BEFORE A REGION OF IFR
STRATUS...THAT IS CURRENTLY OVER WRN ONTARIO AND MANITOBA...DROPS
SOUTH INTO THE STATE LATE TONIGHT. EXPECT AREAS OF IFR CIGS BY
SUNDAY MORNING WITH MOST FAVORED REGIONS OVER NORTHERN SITES.
BREEZY WESTERLY WINDS WILL BECOME NORTHWESTERLY OVERNIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DONAVON
LONG TERM...REV
AVIATION...DONAVON
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
549 PM CST SUN JAN 3 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Monday)
Issued at 329 PM CST SUN JAN 3 2016
Tonight and Monday
Mid level ridging over the central CONUS continues to increase this
afternoon as broad troughing occurs from the Midwest towards the
Great Lakes region. Low stratus on the eastern edge of the high
pressure over Iowa into northern Missouri has slowly sank southward
through the day today. As the sun sets, temps currently in the
mid and upper 30s will quickly cool, carrying the stratus westward.
Forecast soundings develop a low stratus layer between 00 and 06Z at
the 950 mb layer. Some uncertainty exists between guidance on
timing of the stratus moving into the area, given the poor handling
of todays temperatures and lack of cloud cover. Forecast sided
closer to the RAP and HRRR solutions which have seemed to handled
trends through the afternoon. This result will also result in warmer
lows tonight in the upper teens and lower 20s given the mostly
cloudy skies. Patchy fog is also of concern, especially over north
central Kansas where cool temps and slower onset of cloud cover
could result in dense fog. Coverage and confidence is not high
enough for a headline at this time.
Sfc ridge progresses slowly eastward into northern Missouri Monday
shifting winds to the east and southeast below 10 mph. If widespread
stratus forms overnight, it will be difficult to mix out especially
over far east central Kansas where mixing remains very weak within
the boundary layer. Clearing is likely for most of the area by late
afternoon as better dry advection and mixing from the southeast will
help temps reach the low and middle 30s.
.LONG TERM...(Monday Night through Sunday)
Issued at 329 PM CST SUN JAN 3 2016
An upper ridge over the Central CONUS Monday
evening will move east Tuesday as a series of shortwave troughs move
into the plains from the desert southwest. The first shortwave
appears to be weakening as it moves through the central plains
Tuesday night and early Wednesday. The second, stronger wave,
should move through Thursday night and Friday. The northern stream
finally gets into the action late in the forecast period as
shortwave energy moves into the northern rockies and plains late in
the period. The models are in general agreement concerning these
large-scale features.
For northeast Kansas, we should have a few rounds of precipitation
associated with the passage of the upper troughs. The initial wave
will have limited moisture to work with Tuesday night and Wednesday.
Only brief focused forcing is expected and deeper moisture around
12Z Wednesday morning. While there is ice in the sounding, light
snow looks favored. However, in the absence of deep moisture and
forcing, soundings suggest a chance of freezing drizzle. Will have a
mixture of light freezing drizzle/light snow Tuesday night and early
Wednesday with small pops. Once the shortwave energy passes, low-
levels should remain nearly saturated over eastern Kansas with
sustained southerly flow in that layer. With only marginal UVV, will
keep a small chances of drizzle/light rain Wednesday into Wednesday
night.
The second round of precipitation Thursday and Friday should be more
significant, but based on temperature profiles at the time, it
should be all liquid precipitation over northeast Kansas. As the
system pulls out Friday night, what is left of the precipitation may
change over to light snow. However, by that point, the precipitation
chances are diminishing quickly.
Dry for the rest of the forecast next weekend with seasonally cold
temperatures. True arctic air should remain out of the area until
after the forecast period, but it may arrive next week.
As for temperatures, small diurnal ranges look likely with the
cloudiness and precipitation expected. Close to normal for highs,
but above normal lows.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 539 PM CST SUN JAN 3 2016
Low confidence forecast this period. Currently, low level stratus
is off to the northeast with the leading edge around Falls City,
NE. The thought is this status may just edge into the KTOP/KFOE
terminals later over night with possibly some scattered clouds at
KMHK. However, the progression of this deck of stratus to the
southwest is not certain as the upper trough is trying to slowly
move east and thus drag the stratus with it. That said, it is
possible for the boundary layer to also cool, as the nighttime
inversion sets up, bringing fog into the forecast and therefore
reduce visibilties for a period of time. It does seem that models
are overdoing this setup a bit, so have not gone as low
category wise as suggested at this point with the low confidence
and the slower than expected progression of the current stratus
deck. Will refine and hopefully have a better handle on timing by
06z time frame. But still forecasting a period of MVFR
transitioning to IFR near the 12z time frame at this point.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Johnson
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
914 PM EST SUN JAN 3 2016
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW SHOWERS TONIGHT AND MONDAY...WITH
THE COLDEST TEMPERATURES OF THE SEASON SO FAR EXPECTED EARLY IN
THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
A DEEPENING UPPER TROUGH IS EXPECTED TO SET UP ACROSS THE GREAT
LAKES REGION TONIGHT AND MON. SNOW SHOWERS SHOULD INCREASE IN
COVERAGE TONIGHT WITH INCRG SHORTWAVE SUPPORT AND LAKE
ENHANCEMENT IN NW FLOW. A HEAVIER SNOW BAND IS EXPECTED OFF LAKES
HURON AND ERIE...INITIALLY ACROSS NW PA OVERNIGHT. THE BAND SHOULD
MOVE WWD THRU WRN PA INTO OH MON MRNG AS THE BOUNDARY LYR FLOW
VEERS TO THE N THRU MON MRNG. THE BAND IS PROGGED TO PERSIST FOR A
FEW HRS ACRS MERCER AND LAWRENCE COUNTIES WHERE THE MOST
ACCUMULATION IS EXPECTED. THE MOVEMENT OF THE BAND SHOULD HELP
LIMIT SNOW ACCUMULATIONS TO ARND AN INCH FOR MUCH OF THE REST OF
THE AREA OUTSIDE OF THE RIDGES...THOUGH SOME LOCALIZED BRIEF
SQUALLS ARE PSBL.
IN ADDITION...UPSLOPE FLOW SHOULD HELP ENHANCE SNOWFALL RATES IN
THE HIGHER TERRAIN OF WV/MD...THOUGH RELATIVELY SHALLOW AND TEMP
INVERSIONS JUST ABV 5KFT SHOULD KEEP ACCUMULATIONS IN THE 2-4 INCH
RANGE. WILL MAINTAIN THE WINTER WEATHER/LK EFCT ADVISORIES AS IS
ATTM. SNOW SHOWERS SHOULD CONTINUE MON UNTIL THE UPR TROF AXIS
SHIFTS E OF THE AREA. AFTER NEAR SEASONAL TEMPS TONIGHT...LITTLE
RECOVERY IS EXPD MON WITH COLD ADVECTION.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
MUCH DRIER ARCTIC AIR WILL MOVE INTO THE AREA MONDAY NIGHT INTO
TUESDAY. CLOUDS SHOULD SCOUR OUT AS A RESULT...AND AS SURFACE HIGH
PRESSURE SETTLES IN OVERHEAD...OVERNIGHT TEMPERATURES WILL GO INTO
FREE FALL. MOS GUIDANCE SUGGEST SOME AREAS IN THE NORTHEASTERN
PORTIONS OF THE CWA AS WELL AS IN THE VALLEYS AMONGST THE RIDGES
MAY WELL APPROACH ZERO. ELSEWHERE...SINGLE DIGITS AND A FEW LOW
TEENS WILL BE POSSIBLE OVERNIGHT BOTH MONDAY AND TUESDAY NIGHT.
HIGHS WILL REMAIN BELOW NORMAL ON TUESDAY BEFORE MODERATING ON
WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RETURN FLOW ON THE BACK SIDE OF HIGH PRESSURE USHERS WARMER AIR
INTO THE AREA WEDNESDAY NIGHT THROUGH THE BALANCE OF THE WORK
WEEK. H8 TEMPS CLIMB BACK TO 4-6C BY FRIDAY YIELDING MAX T IN THE
40S. LONG RANGE 12Z OPERATIONAL RUNS CONTINUE TO CONCUR WITH 06Z
ENSEMBLE MEANS OF A WARM FRONT PASSING THROUGH FRIDAY NIGHT INTO
SATURDAY MORNING. SURFACE PRESSURE FIELDS YIELD A COLD AIR DAMMING
SETUP WITH A 30 KNOT BARRIER JET. TEMPERATURES AT THIS TIME ARE
PROGGED TO BE IN THE MID AND UPPER 30S OVER THE MOUNTAIN VALLEYS
OF WESTERN MARYLAND AND NORTHERN WEST VIRGINIA...SO PTYPE IS NOT A
CONCERN AT THIS POINT. HOWEVER...IF COLDER AIR DOES NOT SCOUR OUT
OF THE DEEPER VALLEYS THAN POTENTIAL EXISTS FOR A FREEZING RAIN.
THIS WILL BE MONITORED OVER COMING DAYS.
DOUBLE BARREL LOW PRESSURE ONE UP THE EAST COAST AND THE OTHER
THROUGH THE GREAT LAKES LEAVES US IN NO MANS LAND SATURDAY NIGHT
AND SUNDAY. STILL ENOUGH DIFFERENTIAL VORTICITY ADVECTION WITH
PLENTY OF MOISTURE IN THE ATMOSPHERIC COLUMN TO GENERATE SHOWERS.
A GRADUAL COOLING BACK TO NORMAL VALUES IN THE MID AND UPPER 30S
HAPPENS SUNDAY.
NOT MUCH CHANGE IN THE FORECAST WITH LIKELY NUMBERS FOR THE WARM
FRONT PASSAGE THEN CHANCE NUMBERS FOR THE WARM SECTOR THIS WEEKEND.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
EXPECT A BAND OF LAKE ENHANCED SNOW TO DEVELOP NEAR KFKL THIS
EVENING INTO NORTHWEST PA AND THEN SHIFT WEST OVERNIGHT INTO
EARLY MONDAY. 18Z MODELS AND LATEST HRRR RUN IS A BIT FASTER
SHIFTING BAND WEST AND HAVE TRIED TO TIME BEST OPPORTUNITY FOR
IFR SNOW SHOWERS BASED ON THIS. BAND WILL BE QUICKLY DECAYING BY
LATE MORNING MONDAY BUT EXPECT SNOW SHOWERS TO REACH KZZV WITH A
PERIOD OF MVFR POSSIBLE. WINDS WILL BE NORTHWEST OVERNIGHT
TURNING NORTH DURING THE MORNING MONDAY AROUND 10 KTS.
.OUTLOOK.../TUESDAY THROUGH FRIDAY/...
NO WIDESPREAD IFR RESTRICTIONS ARE EXPECTED.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY FROM 1 AM TO 4 PM EST MONDAY FOR
MDZ001.
OH...NONE.
PA...LAKE EFFECT SNOW ADVISORY UNTIL 9 AM EST MONDAY FOR PAZ007-013.
WV...WINTER WEATHER ADVISORY FROM 1 AM TO 4 PM EST MONDAY FOR
WVZ512-514.
&&
$$
07/10
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
716 PM EST SUN JAN 3 2016
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW SHOWERS TONIGHT INTO MONDAY...WITH
THE COLDEST TEMPERATURES OF THE SEASON SO FAR EXPECTED EARLY IN
THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
A DEEPENING UPPER TROUGH IS EXPECTED TO SET UP ACROSS THE GREAT
LAKES REGION TONIGHT AND MON. A SECONDARY SFC COLD FRONT IS ALSO
PROGGED FOR AN OVERNIGHT PASSAGE. SNOW SHOWERS SHOULD INCREASE IN
COVERAGE TONIGHT WITH INCRG SHORTWAVE SUPPORT. LAKE ENHANCEMENT IS
ALSO PROGGED OFF LAKES ERIE AND HURON WITH NW FLOW. THIS SHOULD
PRODUCE A SNOW BAND INITIALLY ACROSS NW PA OVERNIGHT...BEFORE
MOVING WWD AS THE BOUNDARY LYR FLOW VEERS TO THE N. THE BAND IS
PROGGED TO PERSIST FOR A FEW HRS ACRS MERCER AND LAWRENCE COUNTIES
WHERE THE MOST ACCUMULATION IS EXPECTED. THE MOVEMENT OF THE BAND
SHOULD HELP LIMIT SNOW ACCUMULATIONS FOR MUCH OF THE REST OF THE
AREA OUTSIDE OF THE RIDGES...THOUGH SOME LOCALIZED BRIEF SQUALLS
ARE PSBL.
IN ADDITION...UPSLOPE FLOW SHOULD HELP ENHANCE SNOWFALL RATES IN
THE HIGHER TERRAIN OF WV/MD...THOUGH RELATIVELY SHALLOW AND TEMP
INVERSIONS JUST ABV 5KFT SHOULD KEEP ACCUMULATIONS IN THE 2-4 INCH
RANGE. WILL MAINTAIN THE WINTER WEATHER/LK EFCT ADVISORIES AS IS
ATTM. THE UPR TROF AXIS IS PROGGED TO SHIFT E OF THE AREA BY
AFTN...WITH A DCREASE IN SNOW SHOWERS EXPECTED. AFTER NEAR
SEASONAL TEMPS TONIGHT...LITTLE RECOVERY IS EXPD MON WITH COLD
ADVECTION.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
MUCH DRIER ARCTIC AIR WILL MOVE INTO THE AREA MONDAY NIGHT INTO
TUESDAY. CLOUDS SHOULD SCOUR OUT AS A RESULT...AND AS SURFACE HIGH
PRESSURE SETTLES IN OVERHEAD...OVERNIGHT TEMPERATURES WILL GO INTO
FREE FALL. MOS GUIDANCE SUGGEST SOME AREAS IN THE NORTHEASTERN
PORTIONS OF THE CWA AS WELL AS IN THE VALLEYS AMONGST THE RIDGES
MAY WELL APPROACH ZERO. ELSEWHERE...SINGLE DIGITS AND A FEW LOW
TEENS WILL BE POSSIBLE OVERNIGHT BOTH MONDAY AND TUESDAY NIGHT.
HIGHS WILL REMAIN BELOW NORMAL ON TUESDAY BEFORE MODERATING ON
WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RETURN FLOW ON THE BACK SIDE OF HIGH PRESSURE USHERS WARMER AIR
INTO THE AREA WEDNESDAY NIGHT THROUGH THE BALANCE OF THE WORK
WEEK. H8 TEMPS CLIMB BACK TO 4-6C BY FRIDAY YIELDING MAX T IN THE
40S. LONG RANGE 12Z OPERATIONAL RUNS CONTINUE TO CONCUR WITH 06Z
ENSEMBLE MEANS OF A WARM FRONT PASSING THROUGH FRIDAY NIGHT INTO
SATURDAY MORNING. SURFACE PRESSURE FIELDS YIELD A COLD AIR DAMMING
SETUP WITH A 30 KNOT BARRIER JET. TEMPERATURES AT THIS TIME ARE
PROGGED TO BE IN THE MID AND UPPER 30S OVER THE MOUNTAIN VALLEYS
OF WESTERN MARYLAND AND NORTHERN WEST VIRGINIA...SO PTYPE IS NOT A
CONCERN AT THIS POINT. HOWEVER...IF COLDER AIR DOES NOT SCOUR OUT
OF THE DEEPER VALLEYS THAN POTENTIAL EXISTS FOR A FREEZING RAIN.
THIS WILL BE MONITORED OVER COMING DAYS.
DOUBLE BARREL LOW PRESSURE ONE UP THE EAST COAST AND THE OTHER
THROUGH THE GREAT LAKES LEAVES US IN NO MANS LAND SATURDAY NIGHT
AND SUNDAY. STILL ENOUGH DIFFERENTIAL VORTICITY ADVECTION WITH
PLENTY OF MOISTURE IN THE ATMOSPHERIC COLUMN TO GENERATE SHOWERS.
A GRADUAL COOLING BACK TO NORMAL VALUES IN THE MID AND UPPER 30S
HAPPENS SUNDAY.
NOT MUCH CHANGE IN THE FORECAST WITH LIKELY NUMBERS FOR THE WARM
FRONT PASSAGE THEN CHANCE NUMBERS FOR THE WARM SECTOR THIS WEEKEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
EXPECT A BAND OF LAKE ENHANCED SNOW TO DEVELOP NEAR KFKL THIS
EVENING INTO NORTHWEST PA AND THEN SHIFT WEST OVERNIGHT INTO
EARLY MONDAY. 18Z MODELS AND LATEST HRRR RUN IS A BIT FASTER
SHIFTING BAND WEST AND HAVE TRIED TO TIME BEST OPPORTUNITY FOR
IFR SNOW SHOWERS BASED ON THIS. BAND WILL BE QUICKLY DECAYING BY
LATE MORNING MONDAY BUT EXPECT SNOW SHOWERS TO REACH KZZV WITH A
PERIOD OF MVFR POSSIBLE. WINDS WILL BE NORTHWEST OVERNIGHT
TURNING NORTH DURING THE MORNING MONDAY AROUND 10 KTS.
.OUTLOOK.../TUESDAY THROUGH FRIDAY/...
NO WIDESPREAD IFR RESTRICTIONS ARE EXPECTED.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY FROM 1 AM TO 4 PM EST MONDAY FOR
MDZ001.
OH...NONE.
PA...LAKE EFFECT SNOW ADVISORY UNTIL 9 AM EST MONDAY FOR PAZ007-013.
WV...WINTER WEATHER ADVISORY FROM 1 AM TO 4 PM EST MONDAY FOR
WVZ512-514.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1251 PM EST SAT JAN 2 2016
.AVIATION...
SUBSIDENCE IN THE WAKE OF THIS MORNINGS TROUGH PASSAGE IS RESULTING
IN A GOOD DEAL OF DRY AIR AND BREAKS IN THE CLOUDS OVER LOWER
MICHIGAN. EVEN WITH THE MODEL SOUNDINGS ADVERTISING A STRENGTHENING
INVERSION...DECIDED TO INTRODUCE SCT CIGS THIS AFTERNOON AND INTO
THE OVERNIGHT. THE NEXT FRONT WILL DROP THROUGH EARLY TONIGHT WHICH
WILL BRING A RETURN OF MVFR...POSSIBLY IFR...CIGS. SOUTHWEST WINDS
WILL INCREASE SOME THIS EVENING GUSTING TO AROUND 20 KNOTS AND WILL
REMAIN ABOVE 10 KNOTS THROUGH THE FORECAST.
FOR DTW...CIGS LOOK TO BE THE IMMEDIATE ISSUES AS BREAKS IN THE
STRATUS ARE EXPANDING ACROSS LOWER MI. WENT SCT FOR SEVERAL HOURS
THIS EVENING TAKING INTO ACCOUNT THE AMOUNT OF DRY AIR UPSTREAM.
CIGS WILL DROP OVERNIGHT WITH ANOTHER COLD FRONTAL PASSAGE.
//DTW THRESHOLD PROBABILITIES...
* LOW IN CEILINGS BELOW 5000 FT THIS EVENING...HIGH FOR
OVERNIGHT AND SUNDAY.
&&
.PREV DISCUSSION...ISSUED 342 AM EST SAT JAN 2 2016
DISCUSSION...
A STRONG SHORT WAVE WILL MOVE INTO NORTHERN ONTARIO DURING THE DAY
AND DEEPEN A SURFACE REFLECTION OF LOW PRESSURE TO THE NORTH OF LAKE
HURON BY EVENING. PRECIPITATION WITH THIS SYSTEM WILL REMAIN WELL
NORTH OF OUR AREA THROUGH TODAY AND TONIGHT LEAVING JUST SOME LOW
IMPACT PATCHY FREEZING DRIZZLE POSSIBLE DURING THE MORNING OVER SE
MICHIGAN. MODEL SOUNDINGS INDICATE FAVORABLE BOUNDARY LAYER LAPSE
RATES UNDER A STRONG INVERSION AND WITH A MODERATE WIND SHEAR
PROFILE. THE LACK OF OBSERVATIONAL EVIDENCE SINCE MIDNIGHT ACTUALLY
MATCHES UP WITH RAP AND NAM DEPICTIONS THAT HIGHLIGHT THE 12Z-15Z
TIME PERIOD AS HAVING THE BEST POTENTIAL BASED ON MODEL QPF. THE NAM
TENDS TO OVERFORECAST QPF IN THESE SCENARIOS BUT IT REMAINS WORTH
THE PATCHY MENTION IN THE GOING FORECAST.
AS THE SURFACE LOW DEVELOPS OVER NORTHERN ONTARIO DURING THE
AFTERNOON...WESTERLY FLOW WILL INCREASE OVER LOWER MICHIGAN AND
SCOUR THE LOW LEVEL THERMAL TROUGH EASTWARD INTO THE NEW ENGLAND
STATES. THIS WILL HELP BOOST AFTERNOON TEMPERATURES INTO THE MID 30S
MOST LOCATIONS DESPITE THE STUBBORN CLOUD PATTERN LOCKED IN OVER THE
REGION. AS MENTIONED ABOVE...THERE IS GOOD AGREEMENT IN SOUNDINGS
ACROSS MODEL SOLUTIONS WITH THE DEPICTION OF A STRONG INVERSION THAT
COULD SUPPORT PATCHY FREEZING DRIZZLE BUT WILL DEFINITELY DUCT A
STEADY SUPPLY OF STRATUS FROM LAKE MICHIGAN. THE BOUNDARY LAYER WILL
BE WARMER THAN YESTERDAY BUT NOT WARM ENOUGH TO SHUT DOWN LAKE CLOUD
PRODUCTION AS 925 MB TEMPS REMAIN BELOW 0C UNTIL LATE IN THE DAY.
THE WARM NOSE WITHIN THE WESTERLY LOW LEVEL FLOW IS THEN SHOWN TO BE
DIRECTED INTO INDIANA/OHIO DURING THE EVENING. THERE COULD BE SOME
BREAKS IN THE STRATUS DURING THIS TIME BEFORE THE PREFRONTAL TROUGH
PUSHES THE WARMER AIR SOUTH.
THE MAIN COLD FRONT WITH THIS SYSTEM WILL SETTLE SOUTHWARD LATER
TONIGHT AS THE SURFACE LOW MOVES INTO QUEBEC. THERE IS GOOD MODEL
AGREEMENT SUNDAY THAT SHOWS THE FRONT MAINTAINING A SLOW SOUTHWARD
PACE THROUGH THROUGH CENTRAL LOWER MICHIGAN AS LARGER SCALE HEIGHT
FALLS CONSOLIDATE OVER THE UPPER MIDWEST. THE FRONT WILL BE A
CONDUIT FOR LAKE ENHANCED SNOW SHOWERS FROM LAKE SUPERIOR AND
NORTHERN LAKE MICHIGAN...SOME OF WHICH COULD DRIFT INTO THE SAGINAW
VALLEY AND THUMB DURING THE DAY PERHAPS WITH SCATTERED COVERAGE.
THE MAIN CONCERN FOR OUR AREA WILL BE SUNDAY NIGHT INTO MONDAY AS
THE LARGER SCALE UPPER TROUGH AXIS MOVES THROUGH AND DRIVES THE
FRONT THROUGH THE REST OF LOWER MICHIGAN. THIS WILL PRODUCE ABOUT A
12 HOUR PERIOD OF STRONG NORTHERLY FLOW OFF LAKE HURON INTO THE
THUMB AND RAISE LAKE EFFECT POTENTIAL. MODELS FORECAST 850 MB TEMPS
MAKING A RUN AT -20C OVER THE LAKE RESULTING IN 0-1KM DELTA THETA-E
NEAR -8 K/KM WHICH ADDS CONFIDENCE TO LAKE EFFECT OCCURRENCE. THE
PROBLEM IS THAT OTHER INGREDIENTS ARE LACKING FOR A SIGNIFICANT
EVENT. LARGE SCALE VERTICAL MOTION WITH THE UPPER TROUGH PIVOTS
QUICKLY THROUGH THE REGION BY MONDAY MORNING AND LEAVES STRONG
SUBSIDENCE BEHIND. THIS IS SHOWN TO FORCE CONVECTIVE DEPTH QUICKLY
BELOW 5000 FT AS THE WIND TURNS NORTHERLY RESULTING IN A HIGH
POP/LOWER ACCUMULATION SCENARIO IN THE THUMB WITH SCATTERED COVERAGE
OF SNOW SHOWERS OVER THE REST OF SE MICHIGAN.
THE OTHER CONSEQUENCE OF THIS ARCTIC FRONT IS THAT IT WILL BRING THE
COLDEST AIR OF THE SEASON INTO SE MICHIGAN FOR THE FIRST HALF OF THE
WEEK. MAX TEMPS LIMITED TO THE LOWER AND MID 20S LOOK GOOD IN
GUIDANCE DATA FOR MONDAY LEADING TO LOWS IN THE TEENS TO SINGLE
DIGITS INTERIOR WHERE SOME CLEARING WILL BE POSSIBLE MONDAY NIGHT
INTO TUESDAY MORNING. THE GOOD NEWS HERE IS THAT THE EL NINO
DOMINATED SEASON WILL SHOW ITSELF AGAIN DURING THE SECOND HALF OF
NEXT WEEK. GLOBAL MODELS INDICATE A PATTERN SHIFT BACK TO A LONG
WAVE TROUGH OUT WEST THAT WILL LEAD TO A RIDGE AND WARMING TREND IN
THE GREAT LAKES.
MARINE...
A RENEWED INCREASE IN SOUTHWESTERLY WINDS IS EXPECTED THROUGH
TONIGHT AS THE PRESSURE GRADIENT STRENGTHENS. THIS WILL RESULT IN A
PROLONGED PERIOD OF SMALL CRAFT CONDITIONS ACROSS ALL LAKE HURON
NEARSHORE WATERS AND SAGINAW BAY. COLDER NORTHWEST FLOW WILL
DEVELOP LATE TONIGHT AND SUNDAY. THE ADDED INSTABILITY WILL RESULT
IN GUSTY CONDITIONS DURING THIS TIME...ALTHOUGH THE POTENTIAL FOR
GUSTS TO REACH GALES OVER LAKE HURON FOR AN EXTENDED PERIOD OF TIME
APPEARS LOW. A MODERATE NORTH TO NORTHEAST FLOW WILL REMAIN IN
PLACE ON MONDAY. THIS WILL MAINTAIN ELEVATED WAVE CONDITIONS
THROUGH THIS TIME. HIGH PRESSURE BUILDING INTO THE REGION WILL
BRING ALLOW BOTH WIND AND WAVE CONDITIONS TO DIMINISH BY MONDAY
NIGHT AND TUESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM 7 AM SUNDAY TO 7 AM EST MONDAY FOR LHZ442-
443.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ422.
SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LHZ421-441.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DRK
DISCUSSION...BT
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
444 AM EST SAT JAN 2 2016
.AVIATION...
WEAK TROUGH WILL LIFT ACROSS THE REGION THIS MORNING...REINFORCING
THE EXISTING STRATUS THROUGH THE DAYLIGHT PERIOD. AREA OBSERVATIONS
AND MODEL GUIDANCE SUGGEST CEILING RESTRICTIONS WILL HOLD AT MVFR
INTO THE EARLY AFTERNOON...BEFORE CLOUD BASES ATTEMPT TO LIFT IN
RESPONSE TO INCREASING INVERSION HEIGHTS. A MODERATE SOUTHWESTERLY
FLOW IN THE WAKE OF THE TROUGH WILL STRENGTHEN THROUGH THE AFTERNOON
AND EVENING. SUSTAINED WINDS INTO THE 15 KNOT RANGE WITH GUSTS UP
TO 25 KNOTS DURING THIS TIME. WINDOW FOR VFR CONDITIONS THIS
EVENING...BEFORE A PASSING COLD FRONT SOLIDIFIES MVFR CIGS AGAIN
LATE TONIGHT AND EARLY SUNDAY.
FOR DTW...CEILINGS WILL HOVER AT OR JUST BELOW 3000 FT THROUGH THE
FIRST HALF OF THE DAY. WINDOW FOR SOME IMPROVEMENT IN CEILING
HEIGHT FROM MID AFTERNOON INTO THE EVENING...THEN RENEWED LOWER
STRATUS WILL FILL IN WITH A COLD FRONTAL PASSAGE OVERNIGHT. SW FLOW
WILL PERSIST WITH GUSTY CONDITIONS EXPECTED TO DEVELOP IN THE 22Z-
02Z TIME FRAME.
//DTW THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS BELOW 5000 FT THROUGH THE FORECAST PERIOD.
&&
.PREV DISCUSSION...ISSUED 342 AM EST SAT JAN 2 2016
DISCUSSION...
A STRONG SHORT WAVE WILL MOVE INTO NORTHERN ONTARIO DURING THE DAY
AND DEEPEN A SURFACE REFLECTION OF LOW PRESSURE TO THE NORTH OF LAKE
HURON BY EVENING. PRECIPITATION WITH THIS SYSTEM WILL REMAIN WELL
NORTH OF OUR AREA THROUGH TODAY AND TONIGHT LEAVING JUST SOME LOW
IMPACT PATCHY FREEZING DRIZZLE POSSIBLE DURING THE MORNING OVER SE
MICHIGAN. MODEL SOUNDINGS INDICATE FAVORABLE BOUNDARY LAYER LAPSE
RATES UNDER A STRONG INVERSION AND WITH A MODERATE WIND SHEAR
PROFILE. THE LACK OF OBSERVATIONAL EVIDENCE SINCE MIDNIGHT ACTUALLY
MATCHES UP WITH RAP AND NAM DEPICTIONS THAT HIGHLIGHT THE 12Z-15Z
TIME PERIOD AS HAVING THE BEST POTENTIAL BASED ON MODEL QPF. THE NAM
TENDS TO OVERFORECAST QPF IN THESE SCENARIOS BUT IT REMAINS WORTH
THE PATCHY MENTION IN THE GOING FORECAST.
AS THE SURFACE LOW DEVELOPS OVER NORTHERN ONTARIO DURING THE
AFTERNOON...WESTERLY FLOW WILL INCREASE OVER LOWER MICHIGAN AND
SCOUR THE LOW LEVEL THERMAL TROUGH EASTWARD INTO THE NEW ENGLAND
STATES. THIS WILL HELP BOOST AFTERNOON TEMPERATURES INTO THE MID 30S
MOST LOCATIONS DESPITE THE STUBBORN CLOUD PATTERN LOCKED IN OVER THE
REGION. AS MENTIONED ABOVE...THERE IS GOOD AGREEMENT IN SOUNDINGS
ACROSS MODEL SOLUTIONS WITH THE DEPICTION OF A STRONG INVERSION THAT
COULD SUPPORT PATCHY FREEZING DRIZZLE BUT WILL DEFINITELY DUCT A
STEADY SUPPLY OF STRATUS FROM LAKE MICHIGAN. THE BOUNDARY LAYER WILL
BE WARMER THAN YESTERDAY BUT NOT WARM ENOUGH TO SHUT DOWN LAKE CLOUD
PRODUCTION AS 925 MB TEMPS REMAIN BELOW 0C UNTIL LATE IN THE DAY.
THE WARM NOSE WITHIN THE WESTERLY LOW LEVEL FLOW IS THEN SHOWN TO BE
DIRECTED INTO INDIANA/OHIO DURING THE EVENING. THERE COULD BE SOME
BREAKS IN THE STRATUS DURING THIS TIME BEFORE THE PREFRONTAL TROUGH
PUSHES THE WARMER AIR SOUTH.
THE MAIN COLD FRONT WITH THIS SYSTEM WILL SETTLE SOUTHWARD LATER
TONIGHT AS THE SURFACE LOW MOVES INTO QUEBEC. THERE IS GOOD MODEL
AGREEMENT SUNDAY THAT SHOWS THE FRONT MAINTAINING A SLOW SOUTHWARD
PACE THROUGH THROUGH CENTRAL LOWER MICHIGAN AS LARGER SCALE HEIGHT
FALLS CONSOLIDATE OVER THE UPPER MIDWEST. THE FRONT WILL BE A
CONDUIT FOR LAKE ENHANCED SNOW SHOWERS FROM LAKE SUPERIOR AND
NORTHERN LAKE MICHIGAN...SOME OF WHICH COULD DRIFT INTO THE SAGINAW
VALLEY AND THUMB DURING THE DAY PERHAPS WITH SCATTERED COVERAGE.
THE MAIN CONCERN FOR OUR AREA WILL BE SUNDAY NIGHT INTO MONDAY AS
THE LARGER SCALE UPPER TROUGH AXIS MOVES THROUGH AND DRIVES THE
FRONT THROUGH THE REST OF LOWER MICHIGAN. THIS WILL PRODUCE ABOUT A
12 HOUR PERIOD OF STRONG NORTHERLY FLOW OFF LAKE HURON INTO THE
THUMB AND RAISE LAKE EFFECT POTENTIAL. MODELS FORECAST 850 MB TEMPS
MAKING A RUN AT -20C OVER THE LAKE RESULTING IN 0-1KM DELTA THETA-E
NEAR -8 K/KM WHICH ADDS CONFIDENCE TO LAKE EFFECT OCCURRENCE. THE
PROBLEM IS THAT OTHER INGREDIENTS ARE LACKING FOR A SIGNIFICANT
EVENT. LARGE SCALE VERTICAL MOTION WITH THE UPPER TROUGH PIVOTS
QUICKLY THROUGH THE REGION BY MONDAY MORNING AND LEAVES STRONG
SUBSIDENCE BEHIND. THIS IS SHOWN TO FORCE CONVECTIVE DEPTH QUICKLY
BELOW 5000 FT AS THE WIND TURNS NORTHERLY RESULTING IN A HIGH
POP/LOWER ACCUMULATION SCENARIO IN THE THUMB WITH SCATTERED COVERAGE
OF SNOW SHOWERS OVER THE REST OF SE MICHIGAN.
THE OTHER CONSEQUENCE OF THIS ARCTIC FRONT IS THAT IT WILL BRING THE
COLDEST AIR OF THE SEASON INTO SE MICHIGAN FOR THE FIRST HALF OF THE
WEEK. MAX TEMPS LIMITED TO THE LOWER AND MID 20S LOOK GOOD IN
GUIDANCE DATA FOR MONDAY LEADING TO LOWS IN THE TEENS TO SINGLE
DIGITS INTERIOR WHERE SOME CLEARING WILL BE POSSIBLE MONDAY NIGHT
INTO TUESDAY MORNING. THE GOOD NEWS HERE IS THAT THE EL NINO
DOMINATED SEASON WILL SHOW ITSELF AGAIN DURING THE SECOND HALF OF
NEXT WEEK. GLOBAL MODELS INDICATE A PATTERN SHIFT BACK TO A LONG
WAVE TROUGH OUT WEST THAT WILL LEAD TO A RIDGE AND WARMING TREND IN
THE GREAT LAKES.
MARINE...
A RENEWED INCREASE IN SOUTHWESTERLY WINDS IS EXPECTED THROUGH
TONIGHT AS THE PRESSURE GRADIENT STRENGTHENS. THIS WILL RESULT IN A
PROLONGED PERIOD OF SMALL CRAFT CONDITIONS ACROSS ALL LAKE HURON
NEARSHORE WATERS AND SAGINAW BAY. COLDER NORTHWEST FLOW WILL
DEVELOP LATE TONIGHT AND SUNDAY. THE ADDED INSTABILITY WILL RESULT
IN GUSTY CONDITIONS DURING THIS TIME...ALTHOUGH THE POTENTIAL FOR
GUSTS TO REACH GALES OVER LAKE HURON FOR AN EXTENDED PERIOD OF TIME
APPEARS LOW. A MODERATE NORTH TO NORTHEAST FLOW WILL REMAIN IN
PLACE ON MONDAY. THIS WILL MAINTAIN ELEVATED WAVE CONDITIONS
THROUGH THIS TIME. HIGH PRESSURE BUILDING INTO THE REGION WILL
BRING ALLOW BOTH WIND AND WAVE CONDITIONS TO DIMINISH BY MONDAY
NIGHT AND TUESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM 7 AM SUNDAY TO 7 AM EST MONDAY FOR LHZ442-
443.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ422.
SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LHZ421-441.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
DISCUSSION...BT
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
342 AM EST SAT JAN 2 2016
.DISCUSSION...
A STRONG SHORT WAVE WILL MOVE INTO NORTHERN ONTARIO DURING THE DAY
AND DEEPEN A SURFACE REFLECTION OF LOW PRESSURE TO THE NORTH OF LAKE
HURON BY EVENING. PRECIPITATION WITH THIS SYSTEM WILL REMAIN WELL
NORTH OF OUR AREA THROUGH TODAY AND TONIGHT LEAVING JUST SOME LOW
IMPACT PATCHY FREEZING DRIZZLE POSSIBLE DURING THE MORNING OVER SE
MICHIGAN. MODEL SOUNDINGS INDICATE FAVORABLE BOUNDARY LAYER LAPSE
RATES UNDER A STRONG INVERSION AND WITH A MODERATE WIND SHEAR
PROFILE. THE LACK OF OBSERVATIONAL EVIDENCE SINCE MIDNIGHT ACTUALLY
MATCHES UP WITH RAP AND NAM DEPICTIONS THAT HIGHLIGHT THE 12Z-15Z
TIME PERIOD AS HAVING THE BEST POTENTIAL BASED ON MODEL QPF. THE NAM
TENDS TO OVERFORECAST QPF IN THESE SCENARIOS BUT IT REMAINS WORTH
THE PATCHY MENTION IN THE GOING FORECAST.
AS THE SURFACE LOW DEVELOPS OVER NORTHERN ONTARIO DURING THE
AFTERNOON...WESTERLY FLOW WILL INCREASE OVER LOWER MICHIGAN AND
SCOUR THE LOW LEVEL THERMAL TROUGH EASTWARD INTO THE NEW ENGLAND
STATES. THIS WILL HELP BOOST AFTERNOON TEMPERATURES INTO THE MID 30S
MOST LOCATIONS DESPITE THE STUBBORN CLOUD PATTERN LOCKED IN OVER THE
REGION. AS MENTIONED ABOVE...THERE IS GOOD AGREEMENT IN SOUNDINGS
ACROSS MODEL SOLUTIONS WITH THE DEPICTION OF A STRONG INVERSION THAT
COULD SUPPORT PATCHY FREEZING DRIZZLE BUT WILL DEFINITELY DUCT A
STEADY SUPPLY OF STRATUS FROM LAKE MICHIGAN. THE BOUNDARY LAYER WILL
BE WARMER THAN YESTERDAY BUT NOT WARM ENOUGH TO SHUT DOWN LAKE CLOUD
PRODUCTION AS 925 MB TEMPS REMAIN BELOW 0C UNTIL LATE IN THE DAY.
THE WARM NOSE WITHIN THE WESTERLY LOW LEVEL FLOW IS THEN SHOWN TO BE
DIRECTED INTO INDIANA/OHIO DURING THE EVENING. THERE COULD BE SOME
BREAKS IN THE STRATUS DURING THIS TIME BEFORE THE PREFRONTAL TROUGH
PUSHES THE WARMER AIR SOUTH.
THE MAIN COLD FRONT WITH THIS SYSTEM WILL SETTLE SOUTHWARD LATER
TONIGHT AS THE SURFACE LOW MOVES INTO QUEBEC. THERE IS GOOD MODEL
AGREEMENT SUNDAY THAT SHOWS THE FRONT MAINTAINING A SLOW SOUTHWARD
PACE THROUGH THROUGH CENTRAL LOWER MICHIGAN AS LARGER SCALE HEIGHT
FALLS CONSOLIDATE OVER THE UPPER MIDWEST. THE FRONT WILL BE A
CONDUIT FOR LAKE ENHANCED SNOW SHOWERS FROM LAKE SUPERIOR AND
NORTHERN LAKE MICHIGAN...SOME OF WHICH COULD DRIFT INTO THE SAGINAW
VALLEY AND THUMB DURING THE DAY PERHAPS WITH SCATTERED COVERAGE.
THE MAIN CONCERN FOR OUR AREA WILL BE SUNDAY NIGHT INTO MONDAY AS
THE LARGER SCALE UPPER TROUGH AXIS MOVES THROUGH AND DRIVES THE
FRONT THROUGH THE REST OF LOWER MICHIGAN. THIS WILL PRODUCE ABOUT A
12 HOUR PERIOD OF STRONG NORTHERLY FLOW OFF LAKE HURON INTO THE
THUMB AND RAISE LAKE EFFECT POTENTIAL. MODELS FORECAST 850 MB TEMPS
MAKING A RUN AT -20C OVER THE LAKE RESULTING IN 0-1KM DELTA THETA-E
NEAR -8 K/KM WHICH ADDS CONFIDENCE TO LAKE EFFECT OCCURRENCE. THE
PROBLEM IS THAT OTHER INGREDIENTS ARE LACKING FOR A SIGNIFICANT
EVENT. LARGE SCALE VERTICAL MOTION WITH THE UPPER TROUGH PIVOTS
QUICKLY THROUGH THE REGION BY MONDAY MORNING AND LEAVES STRONG
SUBSIDENCE BEHIND. THIS IS SHOWN TO FORCE CONVECTIVE DEPTH QUICKLY
BELOW 5000 FT AS THE WIND TURNS NORTHERLY RESULTING IN A HIGH
POP/LOWER ACCUMULATION SCENARIO IN THE THUMB WITH SCATTERED COVERAGE
OF SNOW SHOWERS OVER THE REST OF SE MICHIGAN.
THE OTHER CONSEQUENCE OF THIS ARCTIC FRONT IS THAT IT WILL BRING THE
COLDEST AIR OF THE SEASON INTO SE MICHIGAN FOR THE FIRST HALF OF THE
WEEK. MAX TEMPS LIMITED TO THE LOWER AND MID 20S LOOK GOOD IN
GUIDANCE DATA FOR MONDAY LEADING TO LOWS IN THE TEENS TO SINGLE
DIGITS INTERIOR WHERE SOME CLEARING WILL BE POSSIBLE MONDAY NIGHT
INTO TUESDAY MORNING. THE GOOD NEWS HERE IS THAT THE EL NINO
DOMINATED SEASON WILL SHOW ITSELF AGAIN DURING THE SECOND HALF OF
NEXT WEEK. GLOBAL MODELS INDICATE A PATTERN SHIFT BACK TO A LONG
WAVE TROUGH OUT WEST THAT WILL LEAD TO A RIDGE AND WARMING TREND IN
THE GREAT LAKES.
&&
.MARINE...
A RENEWED INCREASE IN SOUTHWESTERLY WINDS IS EXPECTED THROUGH
TONIGHT AS THE PRESSURE GRADIENT STRENGTHENS. THIS WILL RESULT IN A
PROLONGED PERIOD OF SMALL CRAFT CONDITIONS ACROSS ALL LAKE HURON
NEARSHORE WATERS AND SAGINAW BAY. COLDER NORTHWEST FLOW WILL
DEVELOP LATE TONIGHT AND SUNDAY. THE ADDED INSTABILITY WILL RESULT
IN GUSTY CONDITIONS DURING THIS TIME...ALTHOUGH THE POTENTIAL FOR
GUSTS TO REACH GALES OVER LAKE HURON FOR AN EXTENDED PERIOD OF TIME
APPEARS LOW. A MODERATE NORTH TO NORTHEAST FLOW WILL REMAIN IN
PLACE ON MONDAY. THIS WILL MAINTAIN ELEVATED WAVE CONDITIONS
THROUGH THIS TIME. HIGH PRESSURE BUILDING INTO THE REGION WILL
BRING ALLOW BOTH WIND AND WAVE CONDITIONS TO DIMINISH BY MONDAY
NIGHT AND TUESDAY.
&&
.AVIATION...ISSUED 1153 PM EST FRI JAN 1 2016
CIGS WILL REMAIN IN THE 1800-2500 FOOT RANGE OVERNIGHT INTO SATURDAY
MORNING WITH A SLIGHT INCREASE IN SNOW FLURRY ACTIVITY AGAIN LATE
TONIGHT/EARLY MORNING AS A WEAK SHORTWAVE TRAVERSES THE AREA. WILL
FOCUS MENTION AT PTK/FNT GIVEN SW LOW LEVEL FLOW...BUT SUSPECT ALL
TERMINALS WILL SEE MINOR FLURRY ACTIVITY FOR A TIME. STEADY SW FLOW
WILL ACTUALLY INCREASE LATE IN THE FORECAST...POST 00Z SATURDAY
EVENING...AS THE PRESSURE GRADIENT TIGHTENS IN ADVANCE OF STRONGER
TROUGH. GUSTS INTO THE 20-25 KT RANGE CAN BE EXPECTED. THIS TROUGH
WILL THEN MOVE THROUGH AREA 06Z-12Z OR SO...BRINGING ADDITIONAL
FLURRIES/SHSNS JUST BEYOND THIS FORECAST PERIOD. WILL MAINTAIN MVFR
CIGS FOR THE MOST PART...BUT MAY SEE SOME BREAKS IN ADVANCE OF THE
TROUGH WITH LOWER VFR NOT OUT OF THE QUESTION.
FOR DTW...CIGS WILL BOUNCE AROUND 2KFT AND REMAIN OVC INTO SATURDAY
MORNING...WITH PASSING FLURRIES IN THE 10Z-14Z TIME FRAME. WHILE
THERE MAY BE A FEW BREAKS IN STRATUS...MVFR CONDITIONS ARE EXPECTED
TO PREVAIL THROUGH MOST/ALL OF FORECAST PERIOD. SW FLOW WILL ALSO
PERSIST WITH GUSTY CONDITIONS EXPECTED TO DEVELOP IN THE 22Z-02Z
TIME FRAME.
//DTW THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS BELOW 5000 FT THROUGH THE FORECAST PERIOD.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM 7 AM SUNDAY TO 7 AM EST MONDAY FOR LHZ442-
443.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ422.
SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LHZ421-441.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
DISCUSSION...BT
MARINE.......MR
AVIATION.....DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1002 PM CST SUN JAN 3 2016
.UPDATE...
ISSUED AT 1002 PM CST SUN JAN 3 2016
ISSUED A DENSE FOG ADVISORY UNTIL 9 AM MONDAY MORNING FOR MUCH OF
WEST CENTRAL THROUGH SOUTH CENTRAL MN. VISIBILITIES CONTINUE TO
LOWER LATE THIS EVENING TO A QUARTER MILE OR LESS ACROSS WEST
CENTRAL MN UNDER THE RIDGE OF HIGH PRESSURE MOVING IN FROM SD.
THE THINKING OVERNIGHT IS THAT THE DENSE FOG WILL EXPAND INTO
SOUTH CENTRAL MN PER HRRR FORECASTS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CST SUN JAN 3 2016
THE SHORT TERM FORECAST CONCERNS ARE CLOUD COVER...HOW FAR SOUTH
AND EAST THE CLEARING LOCATED IN NW MN WILL EXTEND AS WELL AS
OVERNIGHT TEMPERATURES ASSOCIATED WITH CLOUDS OR NO CLOUDS.
SATELLITE SHOWS CLEAR SKIES OVER NW MN AND ALL OF ND AND MOST OF SD.
THIS AREA OF CLEARING IS SLOWLY MOVING SOUTHEAST AND IT IS
QUESTIONABLE AS TO HOW FAR SOUTH AND EAST IT WILL GO. MODEL
SOLUTIONS ARE SOMEWHAT MIXED. THE HRRR WANTS TO MIX OUT CLOUDS IN A
SOMEWHAT NATURAL PROGRESSION FROM NW TO SE. THE VARIOUS HOPWRF RUNS
ARE SOMEWHAT CONFLICTING TOO. IF YOU USE H875 OR H900 RH AS A PROXY
FOR WHERE CLOUDS ARE AND ARE NOT...THE GFS SHUNTS RH EAST OF THE
AREA AROUND 06Z. THE NAM IS EVEN FASTER. THE CHALLENGE IS WITH HIGH
PRESSURE WEST OF THE AREA AND DRIFTING SE TOWARD SW MN THERE IS NO
COMPELLING ARGUMENT FOR UNLOADING ENOUGH OF THE LOW LEVEL MOISTURE
TO SCATTER THE CLOUDS OUT. TO MAKE THINGS MORE CHALLENGING AREA THAT
WERE DOMINATED BY THE HIGH PRESSURE TODAY SAW VIRTUALLY NO LOSS OF
CLOUD COVER. AS A RESULT WILL SLOWLY SCATTER THE CLOUDS BETWEEN THE
I-94 CORRIDOR AND THE MN RIVER VALLEY TONIGHT. THERE MAY BE SOME
BREAK IN THE CLOUDS AS FAR SOUTH AND EAST AS THE TWIN
CITIES. SO WILL CONTINUE THAT TREND INTO MONDAY. WESTERN WI WILL
REMAIN OVERCAST. OVERNIGHT LOWS WERE ADJUSTED TO ACCOUNT FOR THE
VARYING CLOUD COVER. MORE SCATTERING OF CLOUDS IS EXPECT ON MONDAY
AS THE HIGH MOVES SOUTHEAST AND WINDS BECOME MORE SOUTHEASTERLY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CST SUN JAN 3 2016
SEVERAL CONCERNS OVER THE NEXT 7 DAYS IN TERMS OF PRECIPITATION
TYPE/SNOWFALL RATIOS AND SFC TEMPS WHICH WILL LEAD TO
UNCERTAINTIES OF SNOWFALL AMTS.
TUESDAY/TUESDAY NIGHT WILL BE DRY...BUT WINDS WILL SHIFT TO THE
SOUTH AND COMMENCE THE MUCH MILDER CONDS FOR WED/THU/FRI BEFORE
PROBABLY THE COLDEST AIR OF THE SEASON MOVES IN NEXT WEEKEND.
FIRST...THE SYSTEM MOVING INTO SOUTHERN CALIFORNIA OVER THE NEXT
12-24 HRS WILL BE THE FIRST INGREDIENT FOR PRECIPITATION TO
DEVELOP LATE WEDNESDAY AFTN/EVENING AS ENERGY FROM THIS SYSTEM
MOVES NE ACROSS THE UPPER MIDWEST. THIS SYSTEM WILL BE RELATIVELY
MOISTURE STARVED INITIALLY...BUT WITH THE INCREASING SOUTHERLY
FLOW AHEAD AND BEHIND IT...QPF AMTS WILL LIKELY INCREASE IN FUTURE
MODEL RUNS. ALSO THIS WILL SET THE STAGE FOR LATE IN THE WEEK AS
ANOTHER SYSTEM MOVES IN...WITH PRECIPITABLE WATER VALUES
INCREASING TO OVER 0.50". ALTHOUGH WEDNESDAY SYSTEM WILL BE COLD
ENOUGH INITIALLY FOR ALL SNOW...AM CONCERN AT THE END AS WET-BULB
TEMPS IN THE FIRST 0-1KM INCREASES TO AROUND +0.5C ALONG THE MN/IA
BORDER. AT LEAST ONCE SNOW DEVELOPS AND SFC TEMPS RISE TO NEAR
FREEZING OR SLIGHTLY ABV...SNOWFALL WILL LIKELY BE LIMITED WITH
SNOWFALL RATIOS DROPPING TO AROUND 8-1 OR 5-1. THIS LEADS TO
SNOWFALL AMOUNTS OF LESS THAN ONE INCH FOR MOST AREAS THAT STAY
ALL SNOW. OUR SNOWFALL PROBABILITIES HAVE A BETTER CHANCE OF 1-2"
OUTSIDE OUR GREATEST QPF AREAS WEST/NW OF THE TWIN CITIES METRO
AREA. SEE THE LATEST TRENDS ON OUR WEB PAGE.
WWW.WEATHER.GOV/MPX/WINTER.
ONCE WEDNESDAY SYSTEM MOVES OFF...THERE SHOULD BE A BREAK IN THE
PRECIPITATION UNTIL LATE THURSDAY NIGHT/FRIDAY DEPENDING UPON THE
SPEED OF THE NEXT SHORTWAVE MOVING OUT OF THE DESERT SW LATE IN
THE WEEK. MOST MODELS HAVE THE BEST TIME FRAME OF PRECIPITATION
DEVELOPING FRIDAY AFTERNOON/EVENING...AND SLOWLY EXITING THE AREA
SATURDAY. HAVE INCREASED POPS TO LIKELY FOR PORTIONS OF MPX CWA
FRIDAY/FRIDAY NIGHT...BUT STILL SOME UNCERTAINTIES ON LOCATION OF
THE BEST LIFT AND SFC FEATURES. BASED ON THE LATEST MODEL
RUNS...IT IS LIKELY THAT THIS SYSTEM WILL BE WARM ENOUGH FOR A
PERIOD OF RAIN OR RAIN/SNOW MIX IN MPX SE CWA. OR BASICALLY FROM
SC TO EC MN AND INTO WC WI. DEPENDING UPON THE UPPER LEVEL
FEATURES...THE WARMER AIR COULD ACTUALLY MOVE FURTHER TO THE NW
ALLOWING FOR MOST OF THE AREA TO SEE RAIN/SNOW BEFORE COLDER AIR
ARRIVES SATURDAY. AGAIN...THIS IS BASED ON THE CURRENT MODEL RUNS
WHICH IS TOO FAR OUT TO GUARANTEE ANY EXACT QPF AND SNOWFALL AMTS.
EVEN IF THE SYSTEM IS COLD ENOUGH FOR ALL SNOW...SNOWFALL RATIOS
WILL LIKELY BE NEAR 10-1 OR LOWER AROUND 6 OR 8-1.
THEREFORE...KEEPING SNOWFALL AMOUNTS ON THE LOW SIDE. SFC TEMPS
WILL REFLECT THE MILDER AIR WITH READINGS HOLDING NEAR FREEZING OR
SLIGHTLY ABOVE ONCE THE PRECIPITATION DEVELOPS.
DUE TO THE FACT THE MODELS HAVE TRENDED TOWARD A LARGE AREA OF
COLD AIR FROM NORTHEAST CANADA TO MOVE SOUTHWARD NEXT
WEEKEND...THE PROBABILITY OF THE COLDEST AIR OF THE SEASON WILL
ARRIVE LATE NEXT WEEKEND AND INTO EARLY NEXT WEEK. OUR FIRST BELOW
ZERO READING /MPX CWA WIDE/ IS ALSO LIKELY DURING THIS TIME
FRAME. IN ADDITION...THE EPO /EASTERN PACIFIC OSCILLATION/ WHICH
IS CURRENTLY NEGATIVE AND WILL REMAIN NEGATIVE THROUGH THE 13TH OF
JANUARY...LEADS TO MUCH COLDER AIR PROBABILITIES ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST. THIS IS THE SAME SCENARIO WITH WPC
BELOW NORMAL TEMPS FOR THE 6-14 DAY TIME PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 552 PM CST SUN JAN 3 2016
LOW CONFIDENCE FORECAST OVERNIGHT AND MONDAY WITH
REGARDS TO CEILINGS AND VISIBILITIES. CLEARING HAS PROGRESSED MUCH
FARTHER SOUTHEAST EARLY THIS EVENING...PUSHING THROUGH THE TWIN
CITIES. IT LOOKS LIKE THE CLEARING OR AT LEAST CEILINGS RISING TO
VFR LEVELS IS POSSIBLE THIS EVENING ACROSS WEST CENTRAL WI. TO THE
WEST...CEILINGS ARE DROPPING TO IFR FROM KAXN TO KRWF AS THE
CENTER OF SURFACE HIGH PRESSURE MOVES INTO WESTERN MN TRAPPING THE
LOW CLOUDS THAT ARE STRUNG OUT ALONG THE MN/SD BORDER. THE CONCERN
OVERNIGHT...WHICH IS SEEN IN THE LATEST HRRR...IS THAT THE IFR
ACROSS WESTERN MN WILL SPREAD EASTWARD AND EXPAND ACROSS KSTC AND
KMSP LATE IN THE NIGHT AND THEN LINGER FOR A TIME ON MONDAY AT ALL
OF OUR TAF SITES. HENCE...FOR AREAS VFR NOW...BROUGHT CEILING BACK
DOWN OVERNIGHT BUT MAY NEED TO HOLD ON TO THEM LONGER ON MONDAY.
WNW WINDS TONIGHT 3-7 KNOTS BECOMING SE 8-14 KNOTS BY MONDAY
AFTERNOON.
KMSP...VFR CONDITIONS THIS EVENING SHOULD GIVE WAY TO LOW MVFR
CEILINGS AND SOME MVFR VSBYS DURING THE OVERNIGHT HOURS. BROUGHT
CONDITIONS BACK TO VFR AFTER 16Z BUT WITH THE HIGH OVERHEAD ON
MONDAY...MVFR CEILINGS MAY LINGER THROUGH THE DAY.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS S 8-16 KTS.
WED...VFR. CHANCE MVFR/-SN. WINDS 5-12 KTS.
THU...VFR. CHANCE MVFR/-SN. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...DENSE FOG ADVISORY UNTIL 9 AM CST MONDAY FOR MNZ047-048-054>057-
064-065-073>075-082-083-091-092.
&&
$$
UPDATE...RAH
SHORT TERM...DRL
LONG TERM...JLT
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
552 PM CST SUN JAN 3 2016
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CST SUN JAN 3 2016
THE SHORT TERM FORECAST CONCERNS ARE CLOUD COVER...HOW FAR SOUTH
AND EAST THE CLEARING LOCATED IN NW MN WILL EXTEND AS WELL AS
OVERNIGHT TEMPERATURES ASSOCIATED WITH CLOUDS OR NO CLOUDS.
SATELLITE SHOWS CLEAR SKIES OVER NW MN AND ALL OF ND AND MOST OF SD.
THIS AREA OF CLEARING IS SLOWLY MOVING SOUTHEAST AND IT IS
QUESTIONABLE AS TO HOW FAR SOUTH AND EAST IT WILL GO. MODEL
SOLUTIONS ARE SOMEWHAT MIXED. THE HRRR WANTS TO MIX OUT CLOUDS IN A
SOMEWHAT NATURAL PROGRESSION FROM NW TO SE. THE VARIOUS HOPWRF RUNS
ARE SOMEWHAT CONFLICTING TOO. IF YOU USE H875 OR H900 RH AS A PROXY
FOR WHERE CLOUDS ARE AND ARE NOT...THE GFS SHUNTS RH EAST OF THE
AREA AROUND 06Z. THE NAM IS EVEN FASTER. THE CHALLENGE IS WITH HIGH
PRESSURE WEST OF THE AREA AND DRIFTING SE TOWARD SW MN THERE IS NO
COMPELLING ARGUMENT FOR UNLOADING ENOUGH OF THE LOW LEVEL MOISTURE
TO SCATTER THE CLOUDS OUT. TO MAKE THINGS MORE CHALLENGING AREA THAT
WERE DOMINATED BY THE HIGH PRESSURE TODAY SAW VIRTUALLY NO LOSS OF
CLOUD COVER. AS A RESULT WILL SLOWLY SCATTER THE CLOUDS BETWEEN THE
I-94 CORRIDOR AND THE MN RIVER VALLEY TONIGHT. THERE MAY BE SOME
BREAK IN THE CLOUDS AS FAR SOUTH AND EAST AS THE TWIN
CITIES. SO WILL CONTINUE THAT TREND INTO MONDAY. WESTERN WI WILL
REMAIN OVERCAST. OVERNIGHT LOWS WERE ADJUSTED TO ACCOUNT FOR THE
VARYING CLOUD COVER. MORE SCATTERING OF CLOUDS IS EXPECT ON MONDAY
AS THE HIGH MOVES SOUTHEAST AND WINDS BECOME MORE SOUTHEASTERLY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CST SUN JAN 3 2016
SEVERAL CONCERNS OVER THE NEXT 7 DAYS IN TERMS OF PRECIPITATION
TYPE/SNOWFALL RATIOS AND SFC TEMPS WHICH WILL LEAD TO
UNCERTAINTIES OF SNOWFALL AMTS.
TUESDAY/TUESDAY NIGHT WILL BE DRY...BUT WINDS WILL SHIFT TO THE
SOUTH AND COMMENCE THE MUCH MILDER CONDS FOR WED/THU/FRI BEFORE
PROBABLY THE COLDEST AIR OF THE SEASON MOVES IN NEXT WEEKEND.
FIRST...THE SYSTEM MOVING INTO SOUTHERN CALIFORNIA OVER THE NEXT
12-24 HRS WILL BE THE FIRST INGREDIENT FOR PRECIPITATION TO
DEVELOP LATE WEDNESDAY AFTN/EVENING AS ENERGY FROM THIS SYSTEM
MOVES NE ACROSS THE UPPER MIDWEST. THIS SYSTEM WILL BE RELATIVELY
MOISTURE STARVED INITIALLY...BUT WITH THE INCREASING SOUTHERLY
FLOW AHEAD AND BEHIND IT...QPF AMTS WILL LIKELY INCREASE IN FUTURE
MODEL RUNS. ALSO THIS WILL SET THE STAGE FOR LATE IN THE WEEK AS
ANOTHER SYSTEM MOVES IN...WITH PRECIPITABLE WATER VALUES
INCREASING TO OVER 0.50". ALTHOUGH WEDNESDAY SYSTEM WILL BE COLD
ENOUGH INITIALLY FOR ALL SNOW...AM CONCERN AT THE END AS WET-BULB
TEMPS IN THE FIRST 0-1KM INCREASES TO AROUND +0.5C ALONG THE MN/IA
BORDER. AT LEAST ONCE SNOW DEVELOPS AND SFC TEMPS RISE TO NEAR
FREEZING OR SLIGHTLY ABV...SNOWFALL WILL LIKELY BE LIMITED WITH
SNOWFALL RATIOS DROPPING TO AROUND 8-1 OR 5-1. THIS LEADS TO
SNOWFALL AMOUNTS OF LESS THAN ONE INCH FOR MOST AREAS THAT STAY
ALL SNOW. OUR SNOWFALL PROBABILITIES HAVE A BETTER CHANCE OF 1-2"
OUTSIDE OUR GREATEST QPF AREAS WEST/NW OF THE TWIN CITIES METRO
AREA. SEE THE LATEST TRENDS ON OUR WEB PAGE.
WWW.WEATHER.GOV/MPX/WINTER.
ONCE WEDNESDAY SYSTEM MOVES OFF...THERE SHOULD BE A BREAK IN THE
PRECIPITATION UNTIL LATE THURSDAY NIGHT/FRIDAY DEPENDING UPON THE
SPEED OF THE NEXT SHORTWAVE MOVING OUT OF THE DESERT SW LATE IN
THE WEEK. MOST MODELS HAVE THE BEST TIME FRAME OF PRECIPITATION
DEVELOPING FRIDAY AFTERNOON/EVENING...AND SLOWLY EXITING THE AREA
SATURDAY. HAVE INCREASED POPS TO LIKELY FOR PORTIONS OF MPX CWA
FRIDAY/FRIDAY NIGHT...BUT STILL SOME UNCERTAINTIES ON LOCATION OF
THE BEST LIFT AND SFC FEATURES. BASED ON THE LATEST MODEL
RUNS...IT IS LIKELY THAT THIS SYSTEM WILL BE WARM ENOUGH FOR A
PERIOD OF RAIN OR RAIN/SNOW MIX IN MPX SE CWA. OR BASICALLY FROM
SC TO EC MN AND INTO WC WI. DEPENDING UPON THE UPPER LEVEL
FEATURES...THE WARMER AIR COULD ACTUALLY MOVE FURTHER TO THE NW
ALLOWING FOR MOST OF THE AREA TO SEE RAIN/SNOW BEFORE COLDER AIR
ARRIVES SATURDAY. AGAIN...THIS IS BASED ON THE CURRENT MODEL RUNS
WHICH IS TOO FAR OUT TO GUARANTEE ANY EXACT QPF AND SNOWFALL AMTS.
EVEN IF THE SYSTEM IS COLD ENOUGH FOR ALL SNOW...SNOWFALL RATIOS
WILL LIKELY BE NEAR 10-1 OR LOWER AROUND 6 OR 8-1.
THEREFORE...KEEPING SNOWFALL AMOUNTS ON THE LOW SIDE. SFC TEMPS
WILL REFLECT THE MILDER AIR WITH READINGS HOLDING NEAR FREEZING OR
SLIGHTLY ABOVE ONCE THE PRECIPITATION DEVELOPS.
DUE TO THE FACT THE MODELS HAVE TRENDED TOWARD A LARGE AREA OF
COLD AIR FROM NORTHEAST CANADA TO MOVE SOUTHWARD NEXT
WEEKEND...THE PROBABILITY OF THE COLDEST AIR OF THE SEASON WILL
ARRIVE LATE NEXT WEEKEND AND INTO EARLY NEXT WEEK. OUR FIRST BELOW
ZERO READING /MPX CWA WIDE/ IS ALSO LIKELY DURING THIS TIME
FRAME. IN ADDITION...THE EPO /EASTERN PACIFIC OSCILLATION/ WHICH
IS CURRENTLY NEGATIVE AND WILL REMAIN NEGATIVE THROUGH THE 13TH OF
JANUARY...LEADS TO MUCH COLDER AIR PROBABILITIES ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST. THIS IS THE SAME SCENARIO WITH WPC
BELOW NORMAL TEMPS FOR THE 6-14 DAY TIME PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 552 PM CST SUN JAN 3 2016
LOW CONFIDENCE FORECAST OVERNIGHT AND MONDAY WITH
REGARDS TO CEILINGS AND VISIBILITIES. CLEARING HAS PROGRESSED MUCH
FARTHER SOUTHEAST EARLY THIS EVENING...PUSHING THROUGH THE TWIN
CITIES. IT LOOKS LIKE THE CLEARING OR AT LEAST CEILINGS RISING TO
VFR LEVELS IS POSSIBLE THIS EVENING ACROSS WEST CENTRAL WI. TO THE
WEST...CEILINGS ARE DROPPING TO IFR FROM KAXN TO KRWF AS THE
CENTER OF SURFACE HIGH PRESSURE MOVES INTO WESTERN MN TRAPPING THE
LOW CLOUDS THAT ARE STRUNG OUT ALONG THE MN/SD BORDER. THE CONCERN
OVERNIGHT...WHICH IS SEEN IN THE LATEST HRRR...IS THAT THE IFR
ACROSS WESTERN MN WILL SPREAD EASTWARD AND EXPAND ACROSS KSTC AND
KMSP LATE IN THE NIGHT AND THEN LINGER FOR A TIME ON MONDAY AT ALL
OF OUR TAF SITES. HENCE...FOR AREAS VFR NOW...BROUGHT CEILING BACK
DOWN OVERNIGHT BUT MAY NEED TO HOLD ON TO THEM LONGER ON MONDAY.
WNW WINDS TONIGHT 3-7 KNOTS BECOMING SE 8-14 KNOTS BY MONDAY
AFTERNOON.
KMSP...VFR CONDITIONS THIS EVENING SHOULD GIVE WAY TO LOW MVFR
CEILINGS AND SOME MVFR VSBYS DURING THE OVERNIGHT HOURS. BROUGHT
CONDITIONS BACK TO VFR AFTER 16Z BUT WITH THE HIGH OVERHEAD ON
MONDAY...MVFR CEILINGS MAY LINGER THROUGH THE DAY.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS S 8-16 KTS.
WED...VFR. CHANCE MVFR/-SN. WINDS 5-12 KTS.
THU...VFR. CHANCE MVFR/-SN. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...DRL
LONG TERM...JLT
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
323 PM CST SAT JAN 2 2016
.SHORT TERM: (Through Late Tonight)
Issued at 323 PM CST Sat Jan 2 2016
Cold front over the Upper Midwest and northeast Plains will dive
south tonight, reaching the I-70 corridor by around 12Z. The latest
runs of the RAP, HRRR and NARRE-TL are now showing about the same,
while the GFS and GFS LAMP guidance are much drier in the low
levels. Ended up hinting at some clouds coming into the area late
tonight, but did not go as cloudy as what most short range guidance
suggests. Latest satellite pictures tho are tending to agree with
the short range guidance...so this forecast may need to be
overhauled later tonight if the clouds continue their march
southward. Used a blend of temperature guidance for lows tonight,
but ended up leaning toward the colder side which is closer to
persistence.
Carney
.LONG TERM: (Sunday through Next Saturday)
Issued at 323 PM CST Sat Jan 2 2016
Pcpn-free weather will persist across our region thru at least
Wednesday, as northwest flow aloft, and a mainly northerly flow at
the surface persists, keeping the column very dry. Thru Monday,
temps will be a bit below seasonal averages, but with a shift of the
low level flow from the south by Tuesday, temps are expected to
return to above average for daytime maxes.
Another interesting forecast issue will be what looks to be an
increasing chance for an extensive area of low level stratus clouds
to invade our region from the north late tonight or Sunday morning.
This stratus, if it does make it down here to any large degree, may
very well persist until Tuesday, when low level flow turns from the
south. Will take it a day at a time for now, with some clearing on
Monday, as confidence increases. Thicker more persistent clouds
will also favor more the lower MET MOS max temps Sunday, and perhaps
into Monday.
The next chance for widespread pcpn look to still be set for late
week, as flow aloft backs from the southwest and different Pacific
systems track across the country. A persistent model signal has
settled on the onset beginning at some point Wednesday night,
peaking Thursday night, and lingering to some extent into the
weekend.
Some good news with a slightly earlier onset is that it looks less
likely temps will cool down sufficiently for wintry pcpn types, and
with above freezing temps now expected, have kept the pcpn all rain
for now. Only on the back-end this weekend where colder air spills
in as the pcpn is pulling out may there be a relatively brief spat
of snow.
Temps should remain above average thru late week.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1148 AM CST Sat Jan 2 2016
VFR flight conditions with west-southwest flow will prevail today
into tonight. A cold front which is currently over the Upper
Midwest/northern Plains will drop into Missouri and Illinois
between 06-12Z Sunday. A fairly expansive area of stratus with
ceilings down in the IFR range will drop out of Canada behind the
front and move south through the Mississippi Valley. Unsure at
this time what the coverage or heights of these clouds will be
when they reach our area, so have just hinted at MVFR in the TAFs
Sunday morning. Could be down below 1000 FT...but those clouds do
have a long way to go and model guidance can`t seem to agree on
heights and coverage so confidence is low at this time.
Specifics for KSTL:
VFR flight conditions with west-southwest flow will prevail today
through most of the night. A cold front which is currently over
the Upper Midwest/northern Plains will pass through the terminal
between 10-12Z. A fairly expansive area of stratus with ceilings
down in the IFR range will drop out of Canada behind the front
and move south through the Mississippi Valley. Unsure at this time
what the coverage or heights of these clouds will be when they
reach Lambert, so have just hinted at MVFR in the TAFs Sunday
morning. Could be down below 1000 FT...but the clouds do have a
long way to go and model guidance can`t seem to agree on
heights and coverage so confidence is low at this time..
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
315 PM CST SAT JAN 2 2016
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 315 PM CST SAT HAN 2 2016
THE PRIMARY FORECAST CONCERNS INCLUDE THE POTENTIAL FOR LOW CLOUDS
LATE TONIGHT INTO SUNDAY AND TEMPERATURES THE NEXT FEW DAYS.
PATTERN ALOFT HAD NOT CHANGED A LOT COMPARED TO YESTERDAY. REX
BLOCK STILL REMAINED TO OUR WEST/NORTHWEST...WITH FAIRLY FAST
FLOW AT 500 MB FROM SASKATCHEWAN AND MANITOBA INTO THE GREAT LAKES
REGION. 850 MB TEMPERATURES HAD WARMED A BIT FROM MONTANA AND
WESTERN NORTH DAKOTA SOUTHEASTWARD INTO OUR AREA. SURFACE ANALYSIS
SHOWED LOW PRESSURE CENTERED NORTHEAST OF LAKE SUPERIOR WITH HIGH
PRESSURE LOCATED TO OUR WEST AND SOUTH. SURFACE WINDS VARIED FROM
SOUTHWEST TO NORTHWEST IN OUR FORECAST AREA.
SATELLITE IMAGERY LOOP SHOWED LOW CLOUDS TO OUR NORTH...DROPPING
DOWN INTO NORTHERN MINNESOTA AND THE FAR NORTHEAST CORNER OF NORTH
DAKOTA. LOOKING AT SOME OF THE SHORT RANGE HIGH RESOLUTION MODELS...
INCLUDING THE 18Z EXPERIMENTAL HRRR...BELIEVE LOW CLOUDS COULD
APPROACH THE NORTHERN PARTS OF THE FORECAST AREA BY 12Z. THE
PREVIOUSLY MENTIONED HRRR THEN BRINGS THESE SOUTH TO OMAHA AND
MUCH OF WESTERN IOWA BY MID TO LATE MORNING. THE GFS AND NAM SHOW
VARYING DEGREES OF LOWER TROPOSPHERIC RELATIVE HUMIDITY VALUES
(AREA AROUND 925 MB SEEMED TO BE BEST LEVEL TO LOOK AT) SO THE
AMOUNT OF CLOUD COVER FOR SUNDAY IS IN QUESTION. WILL COUNT ON
SKIES AT LEAST BECOMING PARTLY CLOUDY FOR NOW.
HIGH PRESSURE AT THE SURFACE WILL SETTLE DOWN ACROSS EASTERN
NEBRASKA AND SOUTHWEST IOWA FOR LATE SUNDAY NIGHT/EARLY MONDAY
MORNING. THINK THERE WILL BE AT LEAST PATCHY FOG WITH LIGHT WINDS.
RETURN FLOW STRENGTHENS MONDAY AND INTO MONDAY NIGHT/TUESDAY. AT
SOME POINT...LOW CLOUDS MAY RETURN...POSSIBLY BY TUESDAY NIGHT.
OVERALL THE NAM MOS TEMPERATURES SEEMED TOO COOL. USED A BLEND...
WITH A DECENT AMOUNT OF WEIGHT GIVEN TO GFS AND ECMWF...ESPECIALLY
FOR HIGHS.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CST SAT JAN 2 2016
THIS PERIOD WILL GET MORE ACTIVE...ESPECIALLY BY THURSDAY. WILL
INCLUDE SOME LOW POPS PRIOR TO THAT...BUT IT MAY END UP BEING MORE
TRACE TYPE PCPN...DRIZZLE/FREEZING DRIZZLE/FLURRIES. LARGE SCALE
FORCING REMAINS WEAK TUESDAY NIGHT INTO WEDNESDAY NIGHT. DEEPER
MOISTURE AND BETTER LARGE SCALE LIFT ARE IN PLACE FROM LATE
THURSDAY INTO EARLY SATURDAY...BUT NOT CONTINUOUSLY. AFTER THAT...
IT APPEARS WE WILL TURN COLDER...AS CANADIAN AIR IS FILTERED DOWN
INTO THE NORTHERN AND CENTRAL PLAINS.
PCPN TYPE WILL LIKELY BE MIXED THURSDAY INTO FRIDAY...THEN MAINLY
JUST LIGHT SNOW BY FRIDAY NIGHT/SATURDAY. WILL REFINE THIS MORE AS
THE EVENT APPROACHES. SOME SNOW ACCUMULATIONS SEEM POSSIBLE.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1143 AM CST SAT JAN 2 2016
VFR CONDITIONS ARE EXPECTED ACROSS THE TAF SITES THROUGH THE
PERIOD. THERE IS A HINT OF A FOG/LOW CLOUD DECK PUSHING IN FROM
THE NORTHEAST LATE TONIGHT AND POSSIBLY OVER THE TAF SITES BY 15Z.
DID ADD A HINT OF THIS IN THE TAFS BUT WILL TREND TO HIT IT HARDER
IN LATER ISSUANCES IF IT APPEARS IT LOOKS MORE LIKELY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
626 AM EST SAT JAN 2 2016
.SYNOPSIS...
A RIDGE OVER THE OHIO VALLEY WILL MOVE SOUTH OF THE AREA TODAY.
LOW PRESSURE WILL MOVE EAST ACROSS THE CENTRAL GREAT LAKES AND
FORCE A TRAILING COLD FRONT SOUTH ACROSS THE REGION SUNDAY NIGHT.
HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES MONDAY NIGHT
INTO TUESDAY. THE HIGH WILL SETTLE IN OVER THE CAROLINA COAST BY
WEDNESDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FLOW HAS SHIFTED OFFSHORE IN THE NORTHEAST SNOWBELT. DRIER AIR AND
SUBSIDENCE PUSHING INTO THE REGION IS ALSO HELPING TO DIMINISH THE
SNOW THREAT AS WELL. SO WENT AHEAD AND REMOVED THE THREAT FOR
SNOW SHOWERS TODAY. OTHERWISE...JUST MADE SOME MINOR ADJUSTMENTS
TO HOURLY TEMPERATURES THIS MORNING.
PREVIOUS DISCUSSION...
LAKE EFFECT SNOW CONTINUES TO WIND DOWN AT
THIS TIME. CANT RULE OUT A BRIEF SNOW SHOWER IN THE NORTHEAST BUT
WILL LIKELY TAKE DOWN THE PRECIPITATION WITH THE NEXT UPDATE.
OTHERWISE...CLEARING CONTINUES TO PUSH INTO THE AREA FROM THE WEST
AS DRIER AIR PUSHES INTO THE REGION. LATEST HRRR MODEL SUGGEST
MORE CLOUDS...CURRENTLY OVER MICHIGAN...WILL MOVE SOUTHEAST ACROSS
THE FORECAST AREA THIS MORNING BUT WILL KEEP IT PARTLY CLOUDY AS
THE BULK OF THE OVERCAST CONDITIONS SHOULD STAY NORTH OF THE
FORECAST AREA. TEMPERATURES HAVE BEEN REALLY TOUGH OVER THE LAST
SEVERAL WEEKS AS GUIDANCE STRUGGLES AGAINST ABNORMALLY WARM
CONDITIONS. FEELING NOW IS THAT WE ARE SETTLING INTO A MORE NORMAL
TEMPERATURE PATTERN AND GUIDANCE TEMPERATURES SHOULD BE MORE
REASONABLE COMPARED TO RECENT MAJOR TEMPERATURE ERRORS. SO WILL BE
DOING A BLEND OF NAM...GFS...AND SREF TEMPERATURES FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
UPPER LEVEL PATTERN SHAPING UP TO BE MORE LIKE A WINTER TIME
PATTERN AS MAJOR UPPER LEVEL RIDGE BUILDS OVER THE ROCKY MOUNTAIN
STATES BY MONDAY MORNING. THIS WILL CAUSE A VIGOROUS UPPER LEVEL
TROUGH TO DEVELOP OVER THE EASTERN HALF OF THE UNITED STATES
SUNDAY INTO MONDAY. THE UPPER LEVEL TROUGH WILL ALLOW ARCTIC AIR
TO PLUNGE SOUTH ACROSS THE FORECAST AREA SUNDAY NIGHT INTO MONDAY.
STRONG HIGH PRESSURE WILL BEGIN TO BUILD IN BEHIND THE ARCTIC AIR
MASS DURING THE LATTER HALF OF THE DAY MONDAY AND THEN SETTLE
SOUTHEAST TOWARD THE CAROLINA COAST.
AS THE LOW PRESSURE SYSTEM MOVES EAST WITH THE TRAILING COLD
FRONT...MOISTURE WILL SPREAD ACROSS THE FORECAST AREA LATE SUNDAY
INTO SUNDAY NIGHT WITH A LIGHT SNOW ACROSS THE ENTIRE AREA.
THEN...AS FLOW BECOMES NORTHWEST SUNDAY NIGHT AND THEN NORTHERLY
BY MONDAY...LAKE EFFECT SNOW SHOWERS WILL DEVELOP IN MULTIBANDS
ACROSS THE NORTHEAST. THIS MULTIBAND SNOW WILL THEN TRANSITION
INTO A SINGLE BAND EXTENDING SOUTH FROM LAKE HURON ACROSS LAKE
ERIE AND BEGIN TO AFFECT THE SECONDARY SNOWBELT REGION SOUTH OF
CLEVELAND. THE WINDOW WILL BE SHORT WHERE ANY ONE LOCATION SEES
THE SNOW AS THE BANDS WILL BE GRADUALLY SHIFTING WITH THE
ADVANCEMENT OF THE HIGH PRESSURE CENTER INTO THE FORECAST AREA.
SNOW ACCUMULATIONS...IF ANY...WILL BE VERY LIGHT ACROSS ALL OF THE
FORECAST AREA SUNDAY NIGHT INTO MONDAY MORNING. HOWEVER...BETTER
SNOWFALL ACCUMULATIONS WILL TAKE PLACE OVER THE PRIMARY AND
SECONDARY SNOWBELTS FROM MONDAY 8 AM THROUGH 1 PM AS THIS IS WHEN
THE GREATEST INSTABILITY WILL OCCUR. LAKE SURFACE TEMPERATURE
COMPARED TO 850 MB TEMPERATURES REACHES 20+ DEGREES CELCIUS. THIS
WILL BE SOME OF THE COLDEST AIR OF THE SEASON AS HIGH TEMPERATURES
STRUGGLE TO CLIMB OUT OF THE 20S FOR HIGHS BY MONDAY. THIS WILL BE
FOLLOWED BY LOWS IN THE TEENS BY TUESDAY MORNING IN THE STRONG
COLD AIR ADVECTION. CONFIDENCE IS FAIRLY LOW THAT ADVISORY OR
WARNING CRITERIA WILL BE MET FOR SNOW ACCUMULATIONS OVER A
WIDESPREAD AREA. SO...WILL NOT BE ISSUING ANY HEADLINES AT THIS
TIME. OBVIOUSLY...WE WILL NEED TO MONITOR THIS SITUATION IN THE
EVENT BANDS APPEAR THEY WILL BECOME NEARLY STATIONARY FOR A PERIOD
OF TIME.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AN UPPER RIDGE WILL BUILD OVER THE AREA TUESDAY AND SLOWLY MOVE OFF
THE EASTERN SEABOARD WEDNESDAY. A FEW SHORT WAVES WILL MOVE THROUGH
THE AREA ALONG THE MID LEVEL RIDGE BUT GIVEN THE LACK OF MOISTURE DO
NOT EXPECT MORE THAN A BRIEF INCREASE IN CLOUDS. THE LOW LEVEL
MOISTURE WILL INCREASE NOTABLY THURSDAY NIGHT AS THE FLOW
STRENGTHENS BETWEEN THE EAST COAST HIGH AND A DEEPENING LOW COMING
OUT OF THE ROCKIES. THE GULF MOISTURE MOVING INTO THE OHIO VALLEY
WILL BE ACCOMPANIED BY WARMER TEMPERATURES RIGHT OFF THE SURFACE.
THIS WILL SUPPORT AN ALL RAIN PRECIP TYPE. SURFACE TEMPERATURE COULD
BE AT OR JUST BELOW FREEZING AT THE ONSET...BUT SOUNDINGS SUGGEST
THIS QUICKLY ERODING ONCE THE RAIN STARTS. THE RAIN WILL INCREASE IN
COVERAGE FRIDAY INTO SATURDAY AS THE SAID LOW AND SUBSEQUENT FORCING
MOVES UP INTO THE GREAT LAKES. TEMPERATURES WILL BE WELL ABOVE
FREEZING THROUGHOUT THE EVENT WITH SOME POTENTIAL FOR SNOW ON THE
BACKSIDE OF THE SYSTEM SATURDAY NIGHT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SUBSIDENCE ASSOCIATED WITH A PASSING SHORT WAVE HAS PRODUCED A
LARGE BREAK IN THE CLOUDS OVER IN/OH THIS MORNING. HOWEVER AS IT
PUSHES EAST...ANOTHER SHORT WAVE SLIDES INTO NW OH. MVFR CEILINGS
WILL RETURN TO THE TAF SITES THROUGH MUCH OF THE DAY. EXPECT SOME
CLEARING ON THE BACKSIDE OF THE SYSTEM TONIGHT. HOWEVER
A LOWER 1500FT CLOUD DECK WILL DEVELOP BY EARLY SUNDAY MORNING.
OUTLOOK...OCCASIONAL NON VFR AGAIN SUNDAY INTO MONDAY...MAINLY
IN EXTREME NE OH/NW PA WITH LAKE EFFECT SNOW SHOWERS.
&&
.MARINE...
THE UPPER LEVEL TROUGH WILL REMAIN OVER THE REGION INTO
NEXT WEEK. A STRONG HIGH PRESSURE SYSTEM WILL SLIDE OVER THE CENTRAL
U.S. WHILE A SERIES OF WEAK TROUGHS MOVE OVER THE GREAT LAKES. THESE
FEATURES WILL SUPPORT SOUTHWESTERLY FLOW FOR THE NEXT SEVERAL DAYS
WITH SPEEDS NEAR 20KT AND WAVES AROUND 4 FT. SMALL CRAFT ADVISORIES
WILL CONTINUE INTO SUNDAY. A STRONG COLD FRONT WILL DIP SOUTH SUNDAY
WITH SOME POTENTIAL FOR ONGOING SMALL CRAFT CONDITIONS WITH WINDS
VEERING TO THE NORTH. WINDS WILL SUBSIDE NEXT WEEK AS THE
BEFORE-MENTIONED HIGH SLIDES EAST OVER THE REGION.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST SUNDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...JAMISON
AVIATION...JAMISON
MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
408 AM EST SAT JAN 2 2016
.SYNOPSIS...
A RIDGE OVER THE OHIO VALLEY WILL MOVE SOUTH OF THE AREA TODAY.
LOW PRESSURE WILL MOVE EAST ACROSS THE CENTRAL GREAT LAKES AND
FORCE A TRAILING COLD FRONT SOUTH ACROSS THE REGION SUNDAY NIGHT.
HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES MONDAY NIGHT
INTO TUESDAY. THE HIGH WILL SETTLE IN OVER THE CAROLINA COAST BY
WEDNESDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LAKE EFFECT SNOW CONTINUES TO WIND DOWN AT THIS TIME. CANT RULE
OUT A BRIEF SNOW SHOWER IN THE NORTHEAST BUT WILL LIKELY TAKE DOWN
THE PRECIPITATION WITH THE NEXT UPDATE. OTHERWISE...CLEARING
CONTINUES TO PUSH INTO THE AREA FROM THE WEST AS DRIER AIR PUSHES
INTO THE REGION. LATEST HRRR MODEL SUGGEST MORE CLOUDS...CURRENTLY
OVER MICHIGAN...WILL MOVE SOUTHEAST ACROSS THE FORECAST AREA THIS
MORNING BUT WILL KEEP IT PARTLY CLOUDY AS THE BULK OF THE OVERCAST
CONDITIONS SHOULD STAY NORTH OF THE FORECAST AREA. TEMPERATURES
HAVE BEEN REALLY TOUGH OVER THE LAST SEVERAL WEEKS AS GUIDANCE
STRUGGLES AGAINST ABNORMALLY WARM CONDITIONS. FEELING NOW IS THAT
WE ARE SETTLING INTO A MORE NORMAL TEMPERATURE PATTERN AND
GUIDANCE TEMPERATURES SHOULD BE MORE REASONABLE COMPARED TO RECENT
MAJOR TEMPERATURE ERRORS. SO WILL BE DOING A BLEND OF
NAM...GFS...AND SREF TEMPERATURES FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
UPPER LEVEL PATTERN SHAPING UP TO BE MORE LIKE A WINTER TIME
PATTERN AS MAJOR UPPER LEVEL RIDGE BUILDS OVER THE ROCKY MOUNTAIN
STATES BY MONDAY MORNING. THIS WILL CAUSE A VIGOROUS UPPER LEVEL
TROUGH TO DEVELOP OVER THE EASTERN HALF OF THE UNITED STATES
SUNDAY INTO MONDAY. THE UPPER LEVEL TROUGH WILL ALLOW ARCTIC AIR
TO PLUNGE SOUTH ACROSS THE FORECAST AREA SUNDAY NIGHT INTO MONDAY.
STRONG HIGH PRESSURE WILL BEGIN TO BUILD IN BEHIND THE ARCTIC AIR
MASS DURING THE LATTER HALF OF THE DAY MONDAY AND THEN SETTLE
SOUTHEAST TOWARD THE CAROLINA COAST.
AS THE LOW PRESSURE SYSTEM MOVES EAST WITH THE TRAILING COLD
FRONT...MOISTURE WILL SPREAD ACROSS THE FORECAST AREA LATE SUNDAY
INTO SUNDAY NIGHT WITH A LIGHT SNOW ACROSS THE ENTIRE AREA.
THEN...AS FLOW BECOMES NORTHWEST SUNDAY NIGHT AND THEN NORTHERLY
BY MONDAY...LAKE EFFECT SNOW SHOWERS WILL DEVELOP IN MULTIBANDS
ACROSS THE NORTHEAST. THIS MULTIBAND SNOW WILL THEN TRANSITION
INTO A SINGLE BAND EXTENDING SOUTH FROM LAKE HURON ACROSS LAKE
ERIE AND BEGIN TO AFFECT THE SECONDARY SNOWBELT REGION SOUTH OF
CLEVELAND. THE WINDOW WILL BE SHORT WHERE ANY ONE LOCATION SEES
THE SNOW AS THE BANDS WILL BE GRADUALLY SHIFTING WITH THE
ADVANCEMENT OF THE HIGH PRESSURE CENTER INTO THE FORECAST AREA.
SNOW ACCUMULATIONS...IF ANY...WILL BE VERY LIGHT ACROSS ALL OF THE
FORECAST AREA SUNDAY NIGHT INTO MONDAY MORNING. HOWEVER...BETTER
SNOWFALL ACCUMULATIONS WILL TAKE PLACE OVER THE PRIMARY AND
SECONDARY SNOWBELTS FROM MONDAY 8 AM THROUGH 1 PM AS THIS IS WHEN
THE GREATEST INSTABILITY WILL OCCUR. LAKE SURFACE TEMPERATURE
COMPARED TO 850 MB TEMPERATURES REACHES 20+ DEGREES CELCIUS. THIS
WILL BE SOME OF THE COLDEST AIR OF THE SEASON AS HIGH TEMPERATURES
STRUGGLE TO CLIMB OUT OF THE 20S FOR HIGHS BY MONDAY. THIS WILL BE
FOLLOWED BY LOWS IN THE TEENS BY TUESDAY MORNING IN THE STRONG
COLD AIR ADVECTION. CONFIDENCE IS FAIRLY LOW THAT ADVISORY OR
WARNING CRITERIA WILL BE MET FOR SNOW ACCUMULATIONS OVER A
WIDESPREAD AREA. SO...WILL NOT BE ISSUING ANY HEADLINES AT THIS
TIME. OBVIOUSLY...WE WILL NEED TO MONITOR THIS SITUATION IN THE
EVENT BANDS APPEAR THEY WILL BECOME NEARLY STATIONARY FOR A PERIOD
OF TIME.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AN UPPER RIDGE WILL BUILD OVER THE AREA TUESDAY AND SLOWLY MOVE OFF
THE EASTERN SEABOARD WEDNESDAY. A FEW SHORT WAVES WILL MOVE THROUGH
THE AREA ALONG THE MID LEVEL RIDGE BUT GIVEN THE LACK OF MOISTURE DO
NOT EXPECT MORE THAN A BRIEF INCREASE IN CLOUDS. THE LOW LEVEL
MOISTURE WILL INCREASE NOTABLY THURSDAY NIGHT AS THE FLOW
STRENGTHENS BETWEEN THE EAST COAST HIGH AND A DEEPENING LOW COMING
OUT OF THE ROCKIES. THE GULF MOISTURE MOVING INTO THE OHIO VALLEY
WILL BE ACCOMPANIED BY WARMER TEMPERATURES RIGHT OFF THE SURFACE.
THIS WILL SUPPORT AN ALL RAIN PRECIP TYPE. SURFACE TEMPERATURE COULD
BE AT OR JUST BELOW FREEZING AT THE ONSET...BUT SOUNDINGS SUGGEST
THIS QUICKLY ERODING ONCE THE RAIN STARTS. THE RAIN WILL INCREASE IN
COVERAGE FRIDAY INTO SATURDAY AS THE SAID LOW AND SUBSEQUENT FORCING
MOVES UP INTO THE GREAT LAKES. TEMPERATURES WILL BE WELL ABOVE
FREEZING THROUGHOUT THE EVENT WITH SOME POTENTIAL FOR SNOW ON THE
BACKSIDE OF THE SYSTEM SATURDAY NIGHT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
LAKE EFFECT SNOW HAS SHIFTED OVER THE LAKE WITH THE SOUTHWEST FLOW
AND WILL NOT BE A CONCERN TODAY. SOME CLEARING OF THE CLOUDS FROM
THE WEST OVERNIGHT WITH AN UPPER LEVEL SHORT WAVE. THE CLOUDS WILL
GRADUALLY FILL BACK IN BEHIND THE SHORT WAVE SATURDAY MORNING.
OUTLOOK...OCCASIONAL NON VFR AGAIN SUNDAY INTO MONDAY...MAINLY IN
EXTREME NE OH/NW PA WITH LAKE EFFECT SNOW SHOWERS.
&&
.MARINE...
THE UPPER LEVEL TROUGH WILL REMAIN OVER THE REGION INTO
NEXT WEEK. A STRONG HIGH PRESSURE SYSTEM WILL SLIDE OVER THE CENTRAL
U.S. WHILE A SERIES OF WEAK TROUGHS MOVE OVER THE GREAT LAKES. THESE
FEATURES WILL SUPPORT SOUTHWESTERLY FLOW FOR THE NEXT SEVERAL DAYS
WITH SPEEDS NEAR 20KT AND WAVES AROUND 4 FT. SMALL CRAFT ADVISORIES
WILL CONTINUE INTO SUNDAY. A STRONG COLD FRONT WILL DIP SOUTH SUNDAY
WITH SOME POTENTIAL FOR ONGOING SMALL CRAFT CONDITIONS WITH WINDS
VEERING TO THE NORTH. WINDS WILL SUBSIDE NEXT WEEK AS THE
BEFORE-MENTIONED HIGH SLIDES EAST OVER THE REGION.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST SUNDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...JAMISON
AVIATION...DJB
MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1130 PM EST FRI JAN 1 2016
.SYNOPSIS...
A SERIES OF TROUGHS WILL TRAVERSE THE GREAT LAKES OVER THE WEEKEND
BRINGING PERIODS OF LAKE EFFECT SNOW. A LARGE AREA OF HIGH PRESSURE
WILL BUILD SOUTHEAST OUT OF CANADA BY MONDAY NIGHT...THEN SLOWLY
MOVE TO THE EAST COAST THROUGH MID-WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATE...INVERSION HAS LOWERED ENOUGH TO BRING THE SIGNIFICANT SNOW
TO AN END AT LEAST ACROSS NERN OHIO AND NWRN PA. STILL BELIEVE
THERE COULD BE ADDITIONAL SNOW SHOWERS LATER WITH THE LONG FETCH
INTO KERI BUT NOT EXPECTING MUCH ACCUM. NO OTHER SIGNIFICANT
CHANGES FOR TONIGHT ALTHOUGH DID TWEAK SNOW AND POPS JUST A BIT
SUNDAY NIGHT AND MONDAY. BIG HIGH BUILDING IN BUT THERE SHOULD BE
A PERIOD OF TIME THAT LAKE EFFECT WITH A HURON FETCH GETS INTO NRN
AND EVEN NORTH CENTRAL OHIO.
ORIGINAL...A WELL ESTABLISHED AND ORGANIZED LAKE EFFECT SNOW BAND
HAS SET UP FROM ERIE PA UP THE SHORELINE INTO NY WITH MODERATE TO
HEAVY SNOWFALL. HAVE UPGRADED THE ADVISORY TO A WARNING. SO FAR
TODAY THIS AREA HAS RECEIVED 3 TO 5 INCHES. AN ADDITIONAL 3 TO 5
INCHES IS EXPECTED THROUGH THIS EVENING...TAPERING AFTER MIDNIGHT.
BOTH THE RAP AND THE NAM SHOW RH DROPPING IN THE DENDRITIC GROWTH
LAYER AFTER 00Z. BEYOND THAT THE FLOW IS EXPECTED TO BACK TO THE
SOUTHWEST DISORGANIZING THE BAND AND PUSHING IT OFFSHORE BY
MORNING. THEREFORE BELIEVE THE HEAVIEST SNOWFALL WILL TAKE PLACE
THROUGH THIS EVENING. IMMEDIATELY OUTSIDE OF THE BAND EXPECT JUST
AN INCH OR TWO AND BEYOND THAT NOTHING MORE THAN A FEW FLURRIES.
THE FAR SOUTHWESTERN COUNTIES MAY EVEN SEE A FEW BREAKS IN THE
OVERCAST OVERNIGHT. TEMPERATURES WILL BE IN THE LOWER AND MID 20S
TONIGHT. THE GUSTS FROM THIS AFTERNOON WILL BE DIMINISHING TOO.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
THE LULL IN THE LAKE EFFECT IS EXPECTED TO LAST THROUGH THE DAY
ON SATURDAY. WINDS REMAIN BACKED TO THE SOUTHWEST AND A PERIOD OF
WARM AIR ADVECTION WILL AID IN SUPPRESSING THE LAKE EFFECT. IT
WILL NOT BE UNTIL SATURDAY NIGHT/SUNDAY WHEN WE GET THE NEXT PUSH
OF COLD AIR AND A WELL DEFINED TROUGH. MODELS HAD BEEN DIFFERING
ON THE AMOUNT OF COLD AIR...BUT ARE NOW IN MUCH BETTER AGREEMENT.
THIS ROUND OF SNOW WILL AFFECT A BROADER AREA OF THE
SNOWBELT...INCLUDING THE SECONDARY SNOWBELT AS WINDS VEER TO THE
NORTHWEST. THIS WILL HAVE TO BE WATCHED AS WE WILL LIKELY SET UP A
LAKE HURON CONNECTION AND THEREFORE ENHANCING THE SNOWFALL.
TEMPERATURES WILL BE SEASONABLE WITH HIGHS ONLY AROUND 30. SUNDAY
NIGHT WHEN THE COLDER AIR ARRIVES...NIGHT LOWS WILL LIKELY DIP
INTO THE TEENS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MODELS CONTINUE TO DISLODGE A CHUNK OF ARCTIC AIR WHICH
SLIDES SOUTH WITH THE TROUGH ALOFT EARLY NEXT WEEK. THE FLOW WILL
REMAIN NORTHERLY OFF OF WARM LAKE ERIE EARLY IN THE WEEK WHICH WILL
MODIFY THE AIR TO SOME EXTENT. I DOUBT THERE WILL BE MUCH SNOW COVER
EXCEPT FOR THE SNOWBELT. NONETHELESS TEMPERATURES WILL BE BELOW
NORMAL AND WILL BE THE COLDEST SO FAR THIS WINTER. HIGHS IN
THE 20S MONDAY AND TUESDAY. SOME SECTIONS OF EXTREME INLAND
NORTHEAST OHIO AND NORTHWEST PA MAY NOT GET OUT OF THE TEENS ON
MONDAY.
THE SURFACE HIGH PRESSURE IS PROGGED TO MOVE OVERHEAD TUESDAY AND OFF
TO THE EAST WEDNESDAY. TEMPERATURES WILL MODIFY BACK TO NORMAL. NOT
SURE HOW WARM IT WILL GET LATER IN THE WEEK AS THERE WILL BE
SOME CHILLY AIR TO THE NORTH TRYING TO TRICKLE DOWN. A SOUTHERN
BRANCH SHORT WAVE WILL TRACK TOWARD THE OHIO VALLEY. IT MAY TAKE A
WHILE FOR PRECIPITATION TO DEVELOP SINCE THE AIR MASS WILL BE QUITE
DRY AT FIRST. WILL JUST CALL FOR A CHANCE OF SHOWERS AT THIS TIME.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
LAKE EFFECT SNOW HAS SHIFTED OVER THE LAKE WITH THE SOUTHWEST FLOW
AND WILL NOT BE A CONCERN TODAY. SOME CLEARING OF THE CLOUDS FROM
THE WEST OVERNIGHT WITH AN UPPER LEVEL SHORT WAVE. THE CLOUDS WILL
GRADUALLY FILL BACK IN BEHIND THE SHORT WAVE SATURDAY MORNING.
OUTLOOK...OCCASIONAL NON VFR AGAIN SUNDAY INTO MONDAY...MAINLY IN
EXTREME NE OH/NW PA WITH LAKE EFFECT SNOW SHOWERS.
&&
.MARINE...
SEVERAL WAVES OF LOW PRESSURE WILL CONTINUE TO PASS TO THE NORTH
ACROSS EASTERN CANADA...WHILE A LARGE AREA OF HIGH PRESSURE
SPREADS ACROSS THE MIDSECTION OF THE COUNTRY. THIS WILL CONTINUE
TO PRODUCE A BRISK SOUTHWEST TO WEST FLOW ON LAKE ERIE. SMALL
CRAFT ADVISORIES WILL CONTINUE FROM ABOUT THE ISLANDS EAST.
A COLD FRONT WILL DROP SOUTH ACROSS THE LAKE ON SUNDAY VEERING THE
WIND NORTHWEST AND NORTH THROUGH EARLY NEXT WEEK. SMALL CRAFT
ADVISORIES WILL LIKELY REMAIN AND MAY BE NEEDED FOR ALL OF THE SOUTH
SHORE.
HIGH PRESSURE FROM CANADA WILL FINALLY SETTLE ACROSS THE LAKE AND
ALLOW THE WINDS AND WAVES TO CALM DOWN MID WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST SUNDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...TK/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...KOSARIK
AVIATION...DJB
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
618 PM PST SUN JAN 3 2016
CORRECTED...TOTAL ICE ACCUMULATIONS EXPECTED TONIGHT.
.SYNOPSIS...A WARM FRONT CONTINUES TO SPREAD PRECIPITATION NORTHWARD
ACROSS NORTHWEST OREGON AND SOUTHWEST WASHINGTON THIS AFTERNOON.
MEANWHILE COLD AIR REMAINS ENTRENCHED EAST OF THE CASCADES...WITH
EAST TO NORTHEASTERLY FLOW AT THE SURFACE KEEPING TEMPERATURES BELOW
FREEZING EAST OF THE COAST RANGE. THIS WILL RESULT IN A MIX OF WINTRY
PRECIPITATION TONIGHT...MAINLY FREEZING RAIN WITH AREAS OF SNOW AND
SLEET NEAR THE GORGE AND THE EAST SLOPES OF THE COAST RANGE. COLD AIR
WILL ONLY SLOWLY MODERATE...WITH SOME CONCERN FOR FREEZING RAIN AGAIN
AS THE NEXT SYSTEM APPROACHES FROM THE SOUTH MONDAY NIGHT AND
TUESDAY...ESPECIALLY NEAR THE COLUMBIA GORGE. ADDITIONAL WEAK WEATHER
SYSTEMS WILL BRING LIGHT PRECIPITATION AT TIMES THROUGH THE END OF
THE UPCOMING WEEK.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY...NWS DOPPLER RADAR SHOWS
ANOTHER SWATH OF PRECIPITATION PUSHING NORTHWARD INTO THE PORTLAND
AND VANCOUVER METRO AREA THIS AFTERNOON. ESRL TROUTDALE PROFILER
SUGGESTS A FREEZING LEVEL AROUND 3500 FT DUE TO THE WARM NOSE MOVING
IN ALOFT. MEANWHILE...THE COLD POOL THROUGH THE COLUMBIA GORGE
APPEARS TO BE 2500 FEET DEEP. THE 1000 FT IN BETWEEN IS PRESENTLY
ABOVE FREEZING ENOUGH TO MELT SNOW FROM ABOVE. AS A RESULT MAINLY
SLEET AND FREEZING RAIN HAVE BEEN REPORTED WITH THIS BATCH OF
PRECIPITATION...THOUGH THERE MAY BE OCCASIONAL PERIODS OF SNOW WITHIN
THIS BAND DUE TO HEAVIER PRECIPITATION BRIEFLY PULLING DOWN THE
GENERAL FREEZING LEVEL CLOSER TO THE TOP OF THE COLD AIR FROM THE
GORGE. THE BEST CHANCE FOR ADDITIONAL SNOW WILL BE IN THE GORGE AND
ALONG THE EAST SLOPES OF THE COAST RANGE WHERE COLD AIR WILL BE
DEEPEST. MOST OF THE PDX METRO CAN EXPECT ABOUT A TENTH OF AN INCH OF
ICE FROM THIS BAND...WITH SOME SPOTS REACHING TWO TENTHS OF AND INCH.
WHERE SNOW FALLS...THIS BAND MAY PRODUCE 1 TO MAYBE 3 INCHES OF NEW SNOW.
TEMPERATURES ARE STRUGGLING TO RISE ABOVE FREEZING ANYWHERE EAST OF
THE COAST RANGE...SO JUST ABOUT ALL PRECIPITATION THAT FALLS COAST
RANGE EASTWARD WILL BE OF THE FREEZING OR FROZEN TYPE.
AS MENTIONED EARLIER...THE SYSTEM PUSHING THIS WARM FRONT NORTHWARD
REMAINS WEAK...AND WILL STRUGGLE TO SCOUR OUT THE COLD AIR FROM THE
INTERIOR. AS A RESULT 850-700 MB FRONTOGENESIS WILL PROBABLY REMAIN
DECENT NORTH OF SALEM MUCH OF TONIGHT. EARLIER RUNS OF THE HRRR WHICH
BROUGHT THE BACK EDGE OF STEADIER PRECIP THROUGH THE PDX METRO AROUND
10 PM LOOK BETTER THAN THE LATEST 22Z RUN. AREAS SOUTH OF SAID BACK
EDGE WILL STILL BE PRONE TO AREAS OF FREEZING DRIZZLE... WITH LIGHT
ACCUMULATIONS. IT IS IMPORTANT TO KEEP IN MIND THAT REGARDLESS OF
INTENSITY...ANY AMOUNT OF FREEZING RAIN OR FREEZING DRIZZLE CAN BE
HAZARDOUS FOR TRAVEL. THEREFORE WE DECIDED TO HOLD ON TO THE WINTER
WX ADVISORY THROUGH 10 AM MONDAY FOR MOST ZONES. THE NORTH COAST WAS
THE EXCEPTION...WHERE TEMPS HAVE GENERALLY RISEN INTO THE MID TO
UPPER 30S.
SHORTWAVE RIDGING WILL MOVE SOUTH TO NORTH ACROSS THE FORECAST AREA
MONDAY FOR A BRIEF BREAK IN THE PRECIPITATION. WHILE THE AIR MASS
WILL BE WARMING ALOFT...EXPECT A MUCH SLOWER MODERATION OF TEMPS AT
THE SURFACE. AM FAIRLY CONFIDENT THAT TEMPS SOUTH OF SALEM WILL RISE
A FEW DEGREES ABOVE FREEZING MONDAY...PERHAPS INTO THE UPPER 30S.
HOWEVER TEMPS EAST OF THE CASCADES REMAIN IN THE TEENS TO MID
20S...WITH PLENTY OF SNOW COVER TO ACT AS A REFRIGERANT. BELIEVE THAT
ALL THE MODELS WE CURRENTLY SEE ARE FAR TOO QUICK IN MODERATING THE
EASTSIDE COLD POOL. WITH EASTERLY FLOW CONTINUING THROUGH THE
GORGE...THIS WILL LIKELY SPELL PROBLEMS FOR THE GORGE AND POSSIBLY
THE PDX METRO AS THE NEXT SYSTEM APPROACHES FROM THE SOUTH AND
SPREADS PRECIPITATION ACROSS THE REGION MON NIGHT/TUE.
THERE REMAINS A LOT OF UNCERTAINTY AS TO WHAT HAPPENS TUESDAY AND
BEYOND...AS A BROAD COMPLEX LOW PRESSURE SYSTEM SETS UP SHOP OVER
MUCH OF THE NE PACIFIC. A SERIES OF MORE COMPACT LOWS WILL ROTATE
AROUND THIS SYSTEM...EACH ENHANCING EASTERLY FLOW THROUGH THE GORGE
AND SPREADING LIGHT TO MODERATE PRECIPITATION INTO THE FORECAST AREA.
WHILE MODELS SUGGEST ONLY CENTRAL AND EASTERN PORTIONS OF THE GORGE
WILL HAVE PROBLEMS WITH WINTRY PRECIPITATION...AM HIGHLY SKEPTICAL
THAT THE PDX METRO AND PERHAPS A BROADER AREA WILL BE OUT OF THE
WOODS BY THEN. FOLLOWING ALONG THIS LINE OF THOUGHT...HELD TEMPS
SEVERAL DEGREES BELOW GUIDANCE AND KEPT OCCASIONAL CHANCES OF FZRA IN
THE FORECAST FOR A LARGE AREA EAST OF THE COAST RANGE THROUGH WED.
ALSO HELD SNOW LEVELS TO THE GORGE FLOOR NEAR HOOD RIVER...AS THE
HOOD RIVER VALLEY AND CENTRAL GORGE WILL PROBABLY SEE MOSTLY SNOW
FROM THESE SYSTEMS. WILL BE AN INTERESTING WINTRY WEATHER PATTERN TO
FOLLOW THE NEXT SEVERAL DAYS. WEAGLE
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...MODELS ARE KEEPING THE
UPPER RIDGE OUT OVER THE NORTHEAST PACIFIC...ALLOWING FOR SHORTWAVES
TO SLIDE SOUTHWARD ALONG THE COAST DOWN INTO OUR AREA. THIS WILL
BRING CHANCES FOR LIGHT PRECIPITATION THROUGH THURSDAY. PREVIOUSLY
MODELS WERE KEEPING FRIDAY MOSTLY DRY...BUT RECENTLY HAVE STARTED
SHOWING A SYSTEM SLIDING DOWN THE COAST FRIDAY. WITH STRONG DRY
EASTERLY FLOW ACROSS THE AREA...STILL THINK THAT ANY PRECIP WITH
THIS SYSTEM WILL STRUGGLE TO MAKE IT INLAND...BUT HAVE ADDED A
SLIGHT CHANCE OF PRECIP ON FRIDAY...MAINLY ACROSS THE NORTHERN HALF
OF OUR AREA. ANY PRECIP WITH STRENGTHENING COLD EASTERLY FLOW
THROUGH THE GORGE COULD BRING MORE WINTRY PRECIP ALL THE WAY DOWN TO
THE VALLEY FLOOR IN THE NORTH WILLAMETTE VALLEY. MODELS SHOW A
GREATER CHANCE FOR PRECIPITATION OVER THE WEEKEND...WITH A LOW-
ELEVATION WINTRY MIX...ESPECIALLY NEAR THE GORGE AND THE NORTH
WILLAMETTE VALLEY. -MCCOY
&&
.AVIATION...PRECIP HAS SWITCHED OVER TO A MIX OF FZRA AND PL
INLAND WITH RA AT THE COAST AND THAT WILL CONTINUE THROUGH THIS
EVENING BEFORE TAPERING OFF OVERNIGHT FROM SOUTH TO NORTH...ENDING
AFTER 05Z SOUTH AROUND KEUG AND AFTER 08Z NORTH AROUND KPDX.
TEMPERATURES INLAND WILL NOT RISE ABOVE FREEZING UNTIL TOMORROW
AFTERNOON. MIX OF MVFR...VFR...AND SOME IFR CONDITIONS ACROSS THE
AREA WILL CONTINUE WITH THE LOWER CONDITIONS IN HEAVIER PRECIP.
STRONG EAST WINDS WILL CONTINUE AROUND THE COLUMBIA RIVER GORGE WITH
RELATIVELY LIGHT NORTHEAST TO NORTHWEST WINDS ELSEWHERE.
KPDX AND APPROACHES...MIX OF PL AND FZRA THIS EVENING THEN
TAPERING OFF OVERNIGHT AFTER 08Z. VIS AND CIG WILL BOUNCE BETWEEN
MVFR AND VFR WITH SOME BRIEF IFR POSSIBLE IN HEAVIER PRECIP. EAST
WINDS FOR THE EASTERN APPROACHES INCLUDING KTTD WITH GUSTS TO
AROUND 30 KT.
&&
.MARINE...WINDS OUT OF THE EAST TO NORTHEAST AROUND 15 TO 20 KT
BUT WITH VERY LITTLE GUSTS. SWELL APPEARS TO BE FINALLY BUILDING
TOWARDS 10 FT AT BUOY 50 BUT IS STILL DELAYED FARTHER NORTH. COMBO
OF W AND S SWELL SHOULD INCREASE SEAS TO ABOVE 10 FT THIS EVENING
AND TONIGHT AND SEAS SHOULD REMAIN AROUND 9 TO 11 FT FOR THE NEXT
FEW DAYS.
A SERIES OF STRONG STORM SYSTEMS SOUTH OF THE ALEUTIANS WILL
EVENTUALLY BUILD LONG PERIOD SWELL WHICH WILL LIKELY ARRIVE ALONG
THE WEST COAST MON NIGHT OR TUE...POSSIBLY PUSHING SEAS TO THE 15
TO 20 RANGE FEET BY MIDWEEK. A LOW PRESSURE SYSTEM WILL MOVE UP
THE COAST TUESDAY AND WEDNESDAY...PRODUCING STRONG WIND GUSTS
APPROACHING GALE FORCE. BOWEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST MONDAY FOR CASCADE
FOOTHILLS IN LANE COUNTY-CENTRAL COAST RANGE OF WESTERN
OREGON-CENTRAL COLUMBIA RIVER GORGE-CENTRAL WILLAMETTE
VALLEY-COAST RANGE OF NORTHWEST OREGON-GREATER PORTLAND
METRO AREA-LOWER COLUMBIA-NORTHERN OREGON CASCADE FOOTHILLS-
SOUTH WILLAMETTE VALLEY-UPPER HOOD RIVER VALLEY-WESTERN
COLUMBIA RIVER GORGE.
WA...WINTER WEATHER ADVISORY UNTIL 10 AM PST MONDAY FOR CENTRAL
COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-I-5 CORRIDOR IN
COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS-WESTERN
COLUMBIA RIVER GORGE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON PST MONDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 9 PM THIS
EVENING TO 1 AM PST MONDAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 9 AM TO 4
PM PST MONDAY.
&&
$$
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
418 PM PST SUN JAN 3 2016
.SYNOPSIS...A WARM FRONT CONTINUES TO SPREAD PRECIPITATION NORTHWARD
ACROSS NORTHWEST OREGON AND SOUTHWEST WASHINGTON THIS AFTERNOON.
MEANWHILE COLD AIR REMAINS ENTRENCHED EAST OF THE CASCADES...WITH
EAST TO NORTHEASTERLY FLOW AT THE SURFACE KEEPING TEMPERATURES BELOW
FREEZING EAST OF THE COAST RANGE. THIS WILL RESULT IN A MIX OF WINTRY
PRECIPITATION TONIGHT...MAINLY FREEZING RAIN WITH AREAS OF SNOW AND
SLEET NEAR THE GORGE AND THE EAST SLOPES OF THE COAST RANGE. COLD AIR
WILL ONLY SLOWLY MODERATE...WITH SOME CONCERN FOR FREEZING RAIN AGAIN
AS THE NEXT SYSTEM APPROACHES FROM THE SOUTH MONDAY NIGHT AND
TUESDAY...ESPECIALLY NEAR THE COLUMBIA GORGE. ADDITIONAL WEAK WEATHER
SYSTEMS WILL BRING LIGHT PRECIPITATION AT TIMES THROUGH THE END OF
THE UPCOMING WEEK.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY...NWS DOPPLER RADAR SHOWS
ANOTHER SWATH OF PRECIPITATION PUSHING NORTHWARD INTO THE PORTLAND
AND VANCOUVER METRO AREA THIS AFTERNOON. ESRL TROUTDALE PROFILER
SUGGESTS A FREEZING LEVEL AROUND 3500 FT DUE TO THE WARM NOSE MOVING
IN ALOFT. MEANWHILE...THE COLD POOL THROUGH THE COLUMBIA GORGE
APPEARS TO BE 2500 FEET DEEP. THE 1000 FT IN BETWEEN IS PRESENTLY
ABOVE FREEZING ENOUGH TO MELT SNOW FROM ABOVE. AS A RESULT MAINLY
SLEET AND FREEZING RAIN HAVE BEEN REPORTED WITH THIS BATCH OF
PRECIPITATION...THOUGH THERE MAY BE OCCASIONAL PERIODS OF SNOW WITHIN
THIS BAND DUE TO HEAVIER PRECIPITATION BRIEFLY PULLING DOWN THE
GENERAL FREEZING LEVEL CLOSER TO THE TOP OF THE COLD AIR FROM THE
GORGE. THE BEST CHANCE FOR ADDITIONAL SNOW WILL BE IN THE GORGE AND
ALONG THE EAST SLOPES OF THE COAST RANGE WHERE COLD AIR WILL BE
DEEPEST. MOST OF THE PDX METRO CAN EXPECT ABOUT A TENTH OF AN INCH OF
ICE FROM THIS BAND...WITH SOME SPOTS REACHING TWO INCHES. WHERE SNOW
FALLS...THIS BAND MAY PRODUCE UP TO 1-3 INCHES OF ADDITIONAL SNOW.
TEMPERATURES ARE STRUGGLING TO RISE ABOVE FREEZING ANYWHERE EAST OF
THE COAST RANGE...SO JUST ABOUT ALL PRECIPITATION THAT FALLS COAST
RANGE EASTWARD WILL BE OF THE FREEZING OR FROZEN TYPE.
AS MENTIONED EARLIER...THE SYSTEM PUSHING THIS WARM FRONT NORTHWARD
REMAINS WEAK...AND WILL STRUGGLE TO SCOUR OUT THE COLD AIR FROM THE
INTERIOR. AS A RESULT 850-700 MB FRONTOGENESIS WILL PROBABLY REMAIN
DECENT NORTH OF SALEM MUCH OF TONIGHT. EARLIER RUNS OF THE HRRR WHICH
BROUGHT THE BACK EDGE OF STEADIER PRECIP THROUGH THE PDX METRO AROUND
10 PM LOOK BETTER THAN THE LATEST 22Z RUN. AREAS SOUTH OF SAID BACK
EDGE WILL STILL BE PRONE TO AREAS OF FREEZING DRIZZLE... WITH LIGHT
ACCUMULATIONS. IT IS IMPORTANT TO KEEP IN MIND THAT REGARDLESS OF
INTENSITY...ANY AMOUNT OF FREEZING RAIN OR FREEZING DRIZZLE CAN BE
HAZARDOUS FOR TRAVEL. THEREFORE WE DECIDED TO HOLD ON TO THE WINTER
WX ADVISORY THROUGH 10 AM MONDAY FOR MOST ZONES. THE NORTH COAST WAS
THE EXCEPTION...WHERE TEMPS HAVE GENERALLY RISEN INTO THE MID TO
UPPER 30S.
SHORTWAVE RIDGING WILL MOVE SOUTH TO NORTH ACROSS THE FORECAST AREA
MONDAY FOR A BRIEF BREAK IN THE PRECIPITATION. WHILE THE AIR MASS
WILL BE WARMING ALOFT...EXPECT A MUCH SLOWER MODERATION OF TEMPS AT
THE SURFACE. AM FAIRLY CONFIDENT THAT TEMPS SOUTH OF SALEM WILL RISE
A FEW DEGREES ABOVE FREEZING MONDAY...PERHAPS INTO THE UPPER 30S.
HOWEVER TEMPS EAST OF THE CASCADES REMAIN IN THE TEENS TO MID
20S...WITH PLENTY OF SNOW COVER TO ACT AS A REFRIGERANT. BELIEVE THAT
ALL THE MODELS WE CURRENTLY SEE ARE FAR TOO QUICK IN MODERATING THE
EASTSIDE COLD POOL. WITH EASTERLY FLOW CONTINUING THROUGH THE
GORGE...THIS WILL LIKELY SPELL PROBLEMS FOR THE GORGE AND POSSIBLY
THE PDX METRO AS THE NEXT SYSTEM APPROACHES FROM THE SOUTH AND
SPREADS PRECIPITATION ACROSS THE REGION MON NIGHT/TUE.
THERE REMAINS A LOT OF UNCERTAINTY AS TO WHAT HAPPENS TUESDAY AND
BEYOND...AS A BROAD COMPLEX LOW PRESSURE SYSTEM SETS UP SHOP OVER
MUCH OF THE NE PACIFIC. A SERIES OF MORE COMPACT LOWS WILL ROTATE
AROUND THIS SYSTEM...EACH ENHANCING EASTERLY FLOW THROUGH THE GORGE
AND SPREADING LIGHT TO MODERATE PRECIPITATION INTO THE FORECAST AREA.
WHILE MODELS SUGGEST ONLY CENTRAL AND EASTERN PORTIONS OF THE GORGE
WILL HAVE PROBLEMS WITH WINTRY PRECIPITATION...AM HIGHLY SKEPTICAL
THAT THE PDX METRO AND PERHAPS A BROADER AREA WILL BE OUT OF THE
WOODS BY THEN. FOLLOWING ALONG THIS LINE OF THOUGHT...HELD TEMPS
SEVERAL DEGREES BELOW GUIDANCE AND KEPT OCCASIONAL CHANCES OF FZRA IN
THE FORECAST FOR A LARGE AREA EAST OF THE COAST RANGE THROUGH WED.
ALSO HELD SNOW LEVELS TO THE GORGE FLOOR NEAR HOOD RIVER...AS THE
HOOD RIVER VALLEY AND CENTRAL GORGE WILL PROBABLY SEE MOSTLY SNOW
FROM THESE SYSTEMS. WILL BE AN INTERESTING WINTRY WEATHER PATTERN TO
FOLLOW THE NEXT SEVERAL DAYS. WEAGLE
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...MODELS ARE KEEPING THE
UPPER RIDGE OUT OVER THE NORTHEAST PACIFIC...ALLOWING FOR SHORTWAVES
TO SLIDE SOUTHWARD ALONG THE COAST DOWN INTO OUR AREA. THIS WILL
BRING CHANCES FOR LIGHT PRECIPITATION THROUGH THURSDAY. PREVIOUSLY
MODELS WERE KEEPING FRIDAY MOSTLY DRY...BUT RECENTLY HAVE STARTED
SHOWING A SYSTEM SLIDING DOWN THE COAST FRIDAY. WITH STRONG DRY
EASTERLY FLOW ACROSS THE AREA...STILL THINK THAT ANY PRECIP WITH
THIS SYSTEM WILL STRUGGLE TO MAKE IT INLAND...BUT HAVE ADDED A
SLIGHT CHANCE OF PRECIP ON FRIDAY...MAINLY ACROSS THE NORTHERN HALF
OF OUR AREA. ANY PRECIP WITH STRENGTHENING COLD EASTERLY FLOW
THROUGH THE GORGE COULD BRING MORE WINTRY PRECIP ALL THE WAY DOWN TO
THE VALLEY FLOOR IN THE NORTH WILLAMETTE VALLEY. MODELS SHOW A
GREATER CHANCE FOR PRECIPITATION OVER THE WEEKEND...WITH A LOW-
ELEVATION WINTRY MIX...ESPECIALLY NEAR THE GORGE AND THE NORTH
WILLAMETTE VALLEY. -MCCOY
&&
.AVIATION...PRECIP HAS SWITCHED OVER TO A MIX OF FZRA AND PL
INLAND WITH RA AT THE COAST AND THAT WILL CONTINUE THROUGH THIS
EVENING BEFORE TAPERING OFF OVERNIGHT FROM SOUTH TO NORTH...ENDING
AFTER 05Z SOUTH AROUND KEUG AND AFTER 08Z NORTH AROUND KPDX.
TEMPERATURES INLAND WILL NOT RISE ABOVE FREEZING UNTIL TOMORROW
AFTERNOON. MIX OF MVFR...VFR...AND SOME IFR CONDITIONS ACROSS THE
AREA WILL CONTINUE WITH THE LOWER CONDITIONS IN HEAVIER PRECIP.
STRONG EAST WINDS WILL CONTINUE AROUND THE COLUMBIA RIVER GORGE WITH
RELATIVELY LIGHT NORTHEAST TO NORTHWEST WINDS ELSEWHERE.
KPDX AND APPROACHES...MIX OF PL AND FZRA THIS EVENING THEN
TAPERING OFF OVERNIGHT AFTER 08Z. VIS AND CIG WILL BOUNCE BETWEEN
MVFR AND VFR WITH SOME BRIEF IFR POSSIBLE IN HEAVIER PRECIP. EAST
WINDS FOR THE EASTERN APPROACHES INCLUDING KTTD WITH GUSTS TO
AROUND 30 KT.
&&
.MARINE...WINDS OUT OF THE EAST TO NORTHEAST AROUND 15 TO 20 KT
BUT WITH VERY LITTLE GUSTS. SWELL APPEARS TO BE FINALLY BUILDING
TOWARDS 10 FT AT BUOY 50 BUT IS STILL DELAYED FARTHER NORTH. COMBO
OF W AND S SWELL SHOULD INCREASE SEAS TO ABOVE 10 FT THIS EVENING
AND TONIGHT AND SEAS SHOULD REMAIN AROUND 9 TO 11 FT FOR THE NEXT
FEW DAYS.
A SERIES OF STRONG STORM SYSTEMS SOUTH OF THE ALEUTIANS WILL
EVENTUALLY BUILD LONG PERIOD SWELL WHICH WILL LIKELY ARRIVE ALONG
THE WEST COAST MON NIGHT OR TUE...POSSIBLY PUSHING SEAS TO THE 15
TO 20 RANGE FEET BY MIDWEEK. A LOW PRESSURE SYSTEM WILL MOVE UP
THE COAST TUESDAY AND WEDNESDAY...PRODUCING STRONG WIND GUSTS
APPROACHING GALE FORCE. BOWEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST MONDAY FOR CASCADE
FOOTHILLS IN LANE COUNTY-CENTRAL COAST RANGE OF WESTERN
OREGON-CENTRAL COLUMBIA RIVER GORGE-CENTRAL WILLAMETTE
VALLEY-COAST RANGE OF NORTHWEST OREGON-GREATER PORTLAND
METRO AREA-LOWER COLUMBIA-NORTHERN OREGON CASCADE FOOTHILLS-
SOUTH WILLAMETTE VALLEY-UPPER HOOD RIVER VALLEY-WESTERN
COLUMBIA RIVER GORGE.
WA...WINTER WEATHER ADVISORY UNTIL 10 AM PST MONDAY FOR CENTRAL
COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-I-5 CORRIDOR IN
COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS-WESTERN
COLUMBIA RIVER GORGE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON PST MONDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 9 PM THIS
EVENING TO 1 AM PST MONDAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 9 AM TO 4
PM PST MONDAY.
&&
$$
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 AUSTIN/SAN ANTONIO TX
1104 PM CST FRI JAN 1 2016
.UPDATE...06Z AVIATION UPDATE BELOW.
&&
.AVIATION...-RA CONTINUES LATE THIS EVENING SOUTH OF A LA GRANGE
TO SAN ANTONIO LINE. THE RAIN SHOULD EXPAND BACK TO THE WEST
OVERNIGHT AND SLIGHTLY NORTH SATURDAY MORNING. CEILINGS GENERALLY
SHOULD REMAIN 5-7K FEET OVERNIGHT...AND THEN GRADUALLY LOWER
DURING THE DAY ON SATURDAY AND INTO SATURDAY NIGHT FROM SOUTHWEST
TO NORTHEAST. NEW 00Z GUIDANCE SUGGESTS CEILINGS TO STEADILY
LOWER THROUGH MVFR CATEGORY AT BOTH DRT AND SAT...POSSIBLY INTO
IFR AT DRT SATURDAY AFTERNOON AND SAT SATURDAY EVENING.
&&
PREV DISCUSSION... /ISSUED 236 PM CST FRI JAN 1 2016/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
AREAS OF LIGHT RAIN CONTINUE TO BE CONFINED TO AREAS SOUTH OF
HIGHWAY 90 AND EXPECT THIS TREND TO CONTINUE FOR THE NEXT SEVERAL
HOURS AT LEAST. 850 MOISTURE IS VASTLY DIFFERENT ACROSS THE CWA
WITH NEARLY SATURATED CONDITIONS ACROSS THE SOUTHWESTERN CWA AND
RH VALUES NEAR 20 PERCENT IN WILLIAMSON COUNTY ACCORDING TO THE
LATEST RAP ANALYSIS. THIS IS WHY WE ARE NOT SEEING MUCH NORTH OF
HIGHWAY 90 AT THIS TIME. LOW-LEVEL MOISTURE VALUES WILL SLOWLY BE
INCREASING THROUGH THE NIGHT AND ALL DAY TOMORROW WHICH SHOULD
ALLOW FOR MORE OF THE CWA TO HAVE BETTER CHANCES OF RAIN.
CURRENTLY...SOUTHWEST FLOW ALOFT IS HELPING CREATE ENOUGH LIFT FOR
THE LIGHT RAIN AND THIS PATTERN IS EXPECTED TO CONTINUE THROUGH
TOMORROW NIGHT WITH A SHORTWAVE TROUGH PASSAGE SHUTTING THINGS
DOWN BY SUNDAY MORNING. THE HIGHEST RAIN CHANCES WILL BE IN THE
SOUTHERN AND SOUTHWESTERN CWA WHERE THE HIGHER MOISTURE VALUES
WILL BE LOCATED. TEMPERATURES THROUGHOUT THE EVENT WILL BE COLD
WITH LOWS TONIGHT AND SATURDAY NIGHT IN THE 30S AND LOWER 40S. THE
COLDER VALUES...LOWER TO MIDDLE 30S WILL BE IN THE NORTHERN HILL
COUNTRY. HIGHS TOMORROW WILL ONLY TOP OUT IN THE LOWER TO UPPER
40S ACROSS THE AREA.
WE HAD BEEN GOING WITH A CHANCE OF SLEET MIXED WITH RAIN FOR THE
NORTHERN HILL COUNTRY WHERE TEMPERATURES ARE EXPECTED TO BE THE
COLDEST BUT HAVE REMOVED THE MENTION OF SLEET IN THE FORECAST.
LATEST FORECAST SOUNDINGS HAVE THE COLUMN BELOW 700 MB ALL ABOVE
FREEZING. THE DRY AIR DOES REMAIN IN THIS SAME LAYER ACROSS THE
NORTHERN CWA AND THAT COULD LEAD TO SOME EVAPORATIVE COOLING BUT
DO NOT THINK WE WILL SEE A SUBSTANTIAL LOWERING OF THE
ENVIRONMENTAL TEMPERATURE. IT WOULD TAKE A DECENT AMOUNT OF QUICK
RAINFALL TO GET THE COOLING NEEDED ONLY DUE TO EFFECTS OF
EVAPORATION. LAPSE RATES ABOVE 700 MB ARE MARGINAL AT BEST AND
ONLY EXPECTING LIGHT RAIN TO FALL FROM THESE HIGHER CLOUD BASES.
SURFACE TEMPS IN THIS TIME FRAME ARE ALSO A BIT WARMER THAN
PREVIOUSLY FORECASTED. NORTHERLY WINDS AT THE SURFACE SHOULD
REMAIN ABOUT 10 MPH OR LESS AND WITH THE LITTLE COLD AIR ADVECTION
COMBINED WITH OVERCAST SKIES...AM NOT EXPECTING THERE TO BE MUCH A
COOL DOWN EACH NIGHT. OUR NEIGHBORING OFFICES TO THE NORTH HAVE
ALSO REMOVED THE MENTION OF SLEET FROM OUR BORDERING COUNTIES.
RAINFALL SHOULD END FROM WEST TO EAST BY SUNDAY MORNING.
LONG TERM (SUNDAY THROUGH FRIDAY)...
LIGHT NORTHERLY FLOW WILL CONTINUE AT THE BEGINNING OF THE LONG-
TERM PORTION OF THE FORECAST KEEPING TEMPERATURES BELOW NORMAL TO
START THE NEW YEAR. IT LOOKS LIKE WE WILL ALSO TRANSITION TO A
PROGRESSIVE UPPER PATTERN TO BEGIN THE YEAR OFF AS WELL. OUR FIRST
FAST-MOVING UPPER TROUGH WILL MOVE THROUGH THE AREA TUESDAY
BRINGING ABOUT A 20 TO 30 PERCENT CHANCE OF RAIN TO THE CWA. AS
THIS SHORTWAVE EXITS...ANOTHER WILL BE ON ITS HEELS AND RAIN
CHANCES SHOULD BE A BIT HIGHER ON WEDNESDAY AND WEDNESDAY NIGHT AS
THIS SHORTWAVE DIGS A BIT DEEPER THAN THE TUESDAY SYSTEM. ANOTHER
TROUGH PASSES THROUGH THE PLAINS ON FRIDAY...BUT WE SHOULD BE DRY
AS THE FORECASTED PATH OF THIS SYSTEM IS THROUGH OKLAHOMA AND
KANSAS. HIGHS IN THE EXTENDED WILL START OFF IN THE 50S BEFORE
WARMING TO AROUND 60 BY THE END OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 38 48 36 56 39 / 20 40 40 10 0
AUSTIN BERGSTROM INTL AIRPORT 38 47 35 55 36 / 20 40 50 10 0
NEW BRAUNFELS MUNI AIRPORT 40 46 36 55 37 / 40 60 50 10 0
BURNET MUNI AIRPORT 35 47 34 54 33 / 20 30 30 - 0
DEL RIO INTL AIRPORT 41 45 38 55 40 / 40 60 30 0 0
GEORGETOWN MUNI AIRPORT 36 47 35 55 37 / 20 20 40 - 0
HONDO MUNI AIRPORT 39 45 37 56 37 / 50 70 50 10 0
SAN MARCOS MUNI AIRPORT 39 46 37 55 37 / 40 50 50 10 0
LA GRANGE - FAYETTE REGIONAL 41 48 39 55 38 / 30 30 50 10 0
SAN ANTONIO INTL AIRPORT 40 46 38 56 39 / 50 60 60 10 0
STINSON MUNI AIRPORT 41 46 39 56 40 / 50 70 60 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...RUNYEN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
849 PM EST SUN JAN 3 2016
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION OVERNIGHT INTO EARLY
MONDAY...BRINGING MUCH COLDER AIR ALONG WITH SNOW SHOWERS AND
STRONG NORTHWEST WINDS TO THE MOUNTAINS THROUGH MONDAY AFTERNOON.
COLD HIGH PRESSURE FOLLOWS THE FRONT MONDAY NIGHT INTO WEDNESDAY
BEFORE MOISTURE STARTS TO RETURN LATE WEDNESDAY NIGHT INTO
THURSDAY. A COMPLEX LOW PRESSURE SYSTEM WILL PASS TO THE WEST
FRIDAY RESULTING IN WARMER TEMPERATURES ALONG WITH MORE
WIDESPREAD RAINFALL FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 830 PM EST SUNDAY...
LEADING EDGE OF THE LOW CLOUD DECK ASSOCIATED WITH A LEAD SURFACE
TROUGH CONTINUES TO ADVANCE SOUTH INTO THE WESTERN SLOPES AND
SHOULD PUSH SOUTHEAST TOWARD THE BLUE RIDGE BY MIDNIGHT. HOWEVER
MOISTURE REMAINS QUITE LIMITED PER CONTINUED VERY DRY EVENING
SOUNDINGS WITH THE CLOUD SHIELD FADING AT TIMES UPON DROPPING
SOUTH. LACK OF DEEPER MOISTURE ALSO A LIMITING FACTOR IN SNOW
SHOWER DEVELOPMENT THIS EVENING...AND APPEARS WILL HAVE TO WAIT
UNTIL AFTER MIDNIGHT NW TO GET COVERAGE GOING PER LATEST RAP AND
LOCAL RNK-WRF SOLUTIONS. FORECAST SOUNDINGS DO SUPPORT MORE BANDED
NATURE SNOW SHOWERS LATE TONIGHT AS AN UPPER WAVE CROSSES BUT
AGAIN QUESTIONS WITH THE SHALLOW NATURE OF THE MOISTURE COLUMN.
APPEARS BEST POTENTIAL FOR BANDING WILL BE TO THE WEST PER
NAM TRAJECTORIES OFF THE LAKES...AND TO THE NORTH CLOSER TO THE
COLD POOL...WITH LIGHTER UPSLOPE DRIVEN SNOW SHOWERS IN BETWEEN.
THUS HAVE CONTINUED TO DELAY THE ONSET OF POPS A FEW HOURS AND CUT
BACK SOME ON SNOWFALL AMOUNTS ESPCLY GIVEN THE SLOWER ONSET AND
LIKELY OFF/ON NATURE TO THE PRECIP. STILL APPEARS THAT THE FAR NW
RIDGES COULD GET AN INCH OR TWO PENDING BANDS...WITH LESS
ELSEWHERE WESTERN SLOPES...AND MAINLY FLURRIES OUT TOWARD THE BLUE
RIDGE.
OTRW BECOMING MOSTLY CLOUDY WEST OVERNIGHT WITH POPS INCREASING
TO HIGH CHANCE/LIKELYS FAR WEST AND SLIGHT POPS ELSEWHERE OUT TO
THE BLUE RIDGE. MAINLY PARTLY CLOUDY EAST FOR EARLY HIGH CLOUDS
AND SOME SPILLOVER OF STRATO- CU LATE BUT DRY. WIDE RANGE OF TEMPS
ONGOING SHOULD PERSIST AS MIXING/CLOUDS INCREASE BUT THEN DROP
INTO THE UNIFORM LOW/MID 20S WEST. SOME RISES POSSIBLE EAST BEFORE
FALLING LATE AS THE ACTUAL 85H BOUNDARY AND BETTER COLD ADVECTION
ARRIVE BY DAYBREAK.
PREVIOUS DISCUSSION AS OF 315 PM EST SUNDAY...
WHILE MOST OF THE REGION IS ENJOYING SEASONABLE TEMPERATURES AND A
GOOD BIT OF SUN...SATELLITE IMAGERY SHOWS A WALL OF LOW CLOUDS TO
OUR NORTH MAKING STEADY PROGRESS TOWARD THE REGION. THESE CLOUDS
ARE ASSOCIATED WITH A COLD FRONT THAT WILL MOVE THROUGH THE
REGION TONIGHT AND BRING WITH IT MUCH COLDER AIR FOR THE START OF
THE WORKWEEK. BLUSTERY NORTHWEST WINDS CAN ALSO BE EXPECTED BEHIND
THE FRONT THROUGH MONDAY...ADDING A BITE TO THE COLD AND MAKING
OUR RECORD WARM DECEMBER SEEM LIKE A DISTANT MEMORY. EXPECT HIGH
TEMPERATURES ON MONDAY TO ONLY BE AROUND 40 DEGREES ACROSS THE
PIEDMONT WITH READINGS IN THE MID 20S/AROUND 30 WEST OF THE BLUE
RIDGE. WIND CHILLS WILL BE IN THE 20S EAST TO TEENS WEST.
THERE IS A GOOD AMOUNT OF SYNOPTIC LOW LEVEL MOISTURE MOVING IN
BEHIND THE FRONT AND THE MESO MODELS INDICATE POTENTIAL FOR UPSTREAM
LAKE INFLUENCE/STREAMERS AS WELL. ADD IN A GOOD NW UPSLOPE TRAJECTORY
AND UPPER SHORT WAVE SUPPORT...AND LOCATIONS FROM THE BLUE RIDGE
WESTWARD CAN EXPECT FLURRIES TO DEVELOP LATE THIS EVENING WITH THE
FAR WESTERN SLOPES SEEING SOME STEADIER SNOW SHOWERS WITH MINOR
ACCUMULATIONS. FROM TONIGHT THROUGH MONDAY... WESTERN GREENBRIER
IN WV CAN EXPECT ACCUMULATIONS AROUND 2 INCHES WITH AMOUNTS OF AN
INCH OR LESS DOWN THROUGH THE WEST FACES OF THE MOUNTAIN EMPIRE
AND GRAYSON HIGHLANDS OF VA INTO THE NORTHWEST MOUNTAINS OF
NC...AND TRACE AMOUNTS IN FLURRIES OUT TO THE BLUE RIDGE. NO
AMOUNTS WILL EXCEED ADVISORY CRITERIA BUT WILL MENTION IN THE HWO
SINCE THIS IS THE FIRST EVENT OF THE SEASON AND IT WILL BE THE
FIRST DAY BACK FROM BREAK FOR MANY SCHOOL DISTRICTS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 315 PM EST SUNDAY...
SOME LINGERING SNOW SHOWERS OR FLURRIES WILL CONTINUE ACROSS THE
PREFERRED WESTERN UPSLOPE AREAS OF THE FORECAST AREA MONDAY NIGHT
THROUGH THE EVENING HOURS. AS MIDNIGHT APPROACHES...LOW LEVEL WINDS
WILL HAVE VEERED MORE NORTHERLY THAN NORTHWEST...AND BY MORNING BE
NORTHEAST. THIS SERIES OF EVENTS WILL TURN OFF THE UPSLOPE MACHINE
ALLOWING FOR AN END OF PRECIPITATION AND A TREND TOWARDS DECREASING
CLOUDS.
HIGH PRESSURE WILL SETTLE OVER THE REGION BY TUESDAY EVENING...AND
THEN SHIFT NORTHEAST TO OVER PA/NJ BY WEDNESDAY NIGHT. THE RESULT
WILL BE PRIMARILY DRY CONDITIONS THROUGH THIS PORTION OF THE
FORECAST. THE ONE EXCEPTION WILL BE THE FAR SOUTHWEST PART OF THE
AREA. AS THE HIGH SHIFTS NORTHEAST...LOW LEVEL FLOW WILL BECOME EAST
OVER THE COAST OF THE CAROLINAS AND SOUTH OVER OUR REGION. THE
RESULT WILL BE AN INCREASE IN ATLANTIC MOISTURE THAT WILL BRING
INCREASING CLOUDS TO THE ENTIRE REGION...AND THE POTENTIAL FOR SOME
LIGHT RAIN OR LIGHT FREEZING RAIN OVER THE MOUNTAINS AND FOOTHILLS
OF NORTH CAROLINA LATE WEDNESDAY NIGHT.
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL AVERAGE 5 TO
10 DEGREES BELOW NORMAL.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 PM EST SUNDAY...
GUIDANCE VARIES ON THE SPECIFIC TIMING OF FEATURES...AND THE PATH
THESE FEATURES WILL TAKE DURING THIS PORTION OF THE FORECAST.
HOWEVER...THE GENERAL PATTERN IS PROGGED TO BE ONE ASSOCIATED WITH A
TROUGH/CLOSED LOW OVER THE CENTRAL PLAINS STATES HEADING NORTHEAST
INTO THE GREAT LAKES. ON ITS FORWARD FLANKS...A SERIES OF
DISTURBANCES ARE PROGGED TO PROGRESS NORTHEAST FROM THE WESTERN GULF
OF MEXICO TO OVER OR NEAR OUR REGION. THE FIRST IS EXPECTED TO
ARRIVE APPROXIMATELY THURSDAY NIGHT INTO FRIDAY. THIS SECOND HAS
MORE OF A SATURDAY NIGHT INTO SUNDAY WINDOW OF ARRIVAL.
LOW LEVEL TEMPERATURES PROFILES HAVE TRENDED SLIGHTLY WARMER WITH
THE FIRST SYSTEM. WE ALREADY HAD A PRIMARILY RAIN FORECAST DURING
THIS THURSDAY NIGHT/FRIDAY TIME PERIOD. THIS TREND STRENGTHENS THIS
LIKELIHOOD. THE TEMPERATURE PROFILE FOR THE SECOND SYSTEM IS MUCH
MORE IN QUESTION. THE GFS SOLUTIONS KEEPS THE GREAT LAKES LOW/TROUGH
DISTINCT FROM THE SOUTHERN STREAM SYSTEM...WITH A MORE PROGRESSIVE
SOLUTION THAT ALLOWS COLDER AIR TO WORK ITS WAY INTO WESTERN PARTS
OF THE AREA BY SUNDAY AFTERNOON. THE ECWMF SOLUTION TRIES TO MERGE
THE TWO SYSTEMS...ALLOWING FOR A SLOW DOWN...AND A MILDER LOW LEVEL
TEMPERATURE PROFILE TO EXIST FOR A LONGER PERIOD OF TIME. OUR
FORECAST WILL REFLECT A CONSENSUS OF THESE TWO.
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND WARMER
EACH DAY AND BE SOME 5 TO 10 DEGREES ABOVE NORMAL BY SUNDAY.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
AS OF 605 PM EST SUNDAY...
EXPECTING VFR TO PREVAIL EAST OF THE MOUNTAINS THIS EVENING WITH
DETERIORATING CONDITIONS OVER THE MOUNTAINS AS A BAND OF LOW
CLOUDS ALONG A COLD FRONT SLIDES IN FROM THE NORTH. MVFR/IFR CIGS
WILL BECOME ESTABLISHED IN UPSLOPE FLOW AT KLWB/KBLF ESPCLY TOWARD
MIDNIGHT WITH OCCASIONAL MVFR IN SHOW SHOWERS AND FLURRIES
CONTINUING INTO MONDAY MORNING. PERIODS OF MVFR CIGS ARE ALSO
EXPECTED AT KBCB MAINLY AFTER MIDNIGHT THROUGH MID MORNING MONDAY
WITH A FEW PASSING FLURRIES OR SNOW SHOWERS POSSIBLE. A FEW HOURS
OF MVFR COULD ALSO OCCUR AT KROA TOWARD EARLY MONDAY WHEN THE BEST
TRANSPORT OF LOW LEVEL MOISTURE OCCURS OTRW THINKING VFR CIGS
THERE AND PERHAPS AT KLYH/KDAN MONDAY MORNING. BASED ON LOW LEVEL
RH FIELDS CIGS MAY START TO RISE ACROSS THE WEST BY MIDDAY MONDAY
BUT GIVEN TENDENCY OF MODELS TO ERODE MOISTURE TOO FAST WITHIN A
STRONG COLD ADVECTION/UPSLOPE REGIME...EXPECT CIGS WILL GO NO
HIGHER THAN MVFR AT KBLF/KLWB FOR THE MOST PART. EXPECT
DOWNSLOPING EAST OF THE RIDGES TO FINALLY DRY THINGS ENOUGH TO
SCATTER ANY CIGS OUT FROM KROA EAST MONDAY AFTERNOON ALTHOUGH SOME
CIGS MAY LINGER AROUND KLYH WHERE WINDS WILL VEER MORE NORTHERLY
DURING THE DAY.
NORTHWEST WINDS SHOULD INCREASE AS THE FRONT CROSSES OVERNIGHT
WITH A FEW GUSTS TOPPING 20-25 KTS OVER THE WESTERN SITES BY
DAYBREAK MONDAY. THE STRONGEST GUSTS CAN BE EXPECTED BY LATE
MONDAY MORNING WHEN THE COLDEST AIR ARRIVES AND MIXING DEEPENS
WITH GUSTS TO 25 OR 30 KNOTS POSSIBLY ESPECIALLY AT
KROA/KBCB/KBLF.
WIDESPREAD VFR SHOULD RETURN MONDAY NIGHT AND CONTINUE THROUGH
MUCH OF WEDNESDAY AS HIGH PRESSURE BUILDS OVERHEAD ALLOWING WINDS
TO DIMINISH.
.EXTENDED AVIATION DISCUSSION...
LOW LEVEL MOISTURE WILL THEN INCREASE LATER WEDNESDAY NIGHT INTO
THURSDAY AS THE HIGH EXITS AND RETURN FLOW DEVELOPS. THIS MAY
BRING MVFR CONDITIONS FOR LATER WEDNESDAY INTO THURSDAY ALONG WITH
SOME SPOTTY VERY LIGHT PRECIP ESPCLY ALONG THE BLUE RIDGE BY EARLY
THURSDAY MORNING. LOW LEVEL MOISTURE WITHIN THE WEDGE LOOKS TO
KEEP AT LEAST PERIODS OF SUB-VFR IN PLACE FOR MUCH OF THURSDAY
ALTHOUGH DEEP MOISTURE LOOKS TOO LIMITED FOR MUCH RAINFALL OUTSIDE
OF SPOTTY DRIZZLE OR SPRINKLES. MORE IN THE WAY OF WIDESPREAD
RAINFALL INCLUDING MVFR/IFR CONDITIONS APPEARS MORE LIKELY LATER
THURSDAY NIGHT INTO FRIDAY AHEAD OF A WARM FRONT APPROACHING FROM
THE SOUTHWEST LATE IN THE DAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/MBS
NEAR TERM...JH/MBS
SHORT TERM...DS
LONG TERM...DS
AVIATION...JH/MBS/WP
AREA FORECAST DISCUSSION
NWS SEATTLE WA
300 PM PST SUN JAN 3 2016
.SYNOPSIS...AN UPPER LEVEL LOW WILL CONTINUE LIFTING NORTHWARD INTO
BRITISH COLUMBIA TONIGHT AND MONDAY. PERIODS OF RAIN AND SNOW
WILL TRANSITION TO ALL RAIN ON MONDAY. A SERIES OF WEAK
SYSTEMS WILL REACH THE AREA TUESDAY THROUGH NEXT WEEKEND. COOLER
AIR MAY FILTER INTO WESTERN WASHINGTON BY SATURDAY.
&&
.SHORT TERM...LATEST RADAR TRENDS SHOW PRECIPITATION TAPERING OFF ACROSS
GREATER PUGET SOUND WITH DRY CONDITIONS TOWARD THE COAST WHERE THE UPPER
LOW RESIDES. THE LOW SEEMS TO HAVE BACKED WWD FURTHER THAN WAS EXPECTED
ALLOWING RAIN AND SNOW BANDS OVER OREGON TO LIFT NORTH ACROSS WRN WA
TODAY. AREAS OF LEWIS...THURSTON...AND INTERIOR PIERCE COUNTY PICKED
UP SPOTTY 1 INCH AMOUNTS AND OTHER AREAS JUST A DUSTING. PRECIPITATION
THE SEATTLE-BELLEVUE METRO AREA HAS BEEN MIXED SO LITTLE OR NO ACCUMULATION
EXCEPT TOWARD THE FOOTHILL AREAS WITH A LITTLE ELEVATION. MOST MODELS
HAVE PERFORMED POORLY TODAY IN THE NEAR TERM SO CONFIDENCE IS NOT ALL THAT
GREAT FOR TONIGHT. THE GFS AND ALSO THE LATEST HRRR LIFT ANOTHER BAND OF
PRECIPITATION INTO THE AREA OVERNIGHT WITH ROUGHLY A QUARTER INCH LIQUID BY
MODAY MORNING. THE NAM-12 IS MUCH HEAVIER WITH ALMOST A HALF INCH LIQUID BUT
KEEPS IT MOSTLY FOCUSED OVER LEWIS/THURSTON AND MAYBE INTERIOR PIERCE
COUNTY. THERE IS ALSO A QUESTION OF PRECIPITATION TYPE WITH SOME MODELS
SHOWING WARMING FROM THE SOUTH AS 1000-850 MB THICKNESS VALUES RISE ABOVE
1300M OVER PUGET SOUND SOMETIME LATE TONIGHT OR EARLY MONDAY MORNING.
SOME LOCATIONS FROM AROUND PORTLAND SOUTHWARD NOW HAVE A MIX OF RAIN/SNOW/
OR FREEZING RAIN. EVENTUALLY THIS WILL BE THE CASE OVER INTERIOR WRN WA BY
MONDAY MORNING. THE ONE AREA THAT COULD HANG ONTO FROZEN PRECIPITATION
LONGER WOULD BE HOOD CANAL/KITSAP WHERE COLD AIR TENDS TO DAM. WITH MODELS
SHOWING ANOTHER BAND OF SNOW MOVING UP TONIGHT THOSE AREAS WERE ADDED TO
THE ADVISORY AND EXTENDED SLIGHTLY THROUGH 6 AM MONDAY. TEMPERATURES ARE
MARGINAL NEAR THE WATER NORTH OF TACOMA SO NOT MUCH ACCUMULATION EXPECTED
AROUND DOWNTOWN SEATTLE OR OTHER COASTLINE LOCATIONS. JUST INLAND FROM THE
WATER...SPOTTY AMOUNTS UNDER ONE INCH ARE POSSIBLE...ESPECIALLY ON HILLTOPS.
MOST MODELS ARE LIGHTER WITH PRECIPITATION AMOUNTS FROM AROUND EVERETT
NORTHWARD. WILL NOT ISSUE AN ADVISORY AT THIS POINT BUT THIS AREA NEEDS TO
BE MONITORED AS TEMPERATURES ARE COLD ENOUGH TO SUPPORT MOSTLY NOW THERE.
THE GFS SHOWS RAIN TAPERING OFF MONDAY NIGHT WITH ONLY LIGHT AMOUNTS. A COUPLE
OF WEAK SYSTEMS EMBEDDED IN SPLIT FLOW WILL AFFECT THE AREA THROUGH MID
WEEK WITH PERIODS OF LIGHT RAIN. TEMPERATURES WILL BE MILDER WITH HIGHS IN THE
40S AND LOWS MOSTLY IN THE 30S.
.LONG TERM...CONFIDENCE REMAINS LOW IN THE EXTENDED FORECAST GIVEN CONSIDERABLE
MODEL VARIATIONS. KEPT AT LEAST CHANCE POPS IN FOR ALL PERIODS THURSDAY INTO
THE WEEKEND...ALTHOUGH SOME DRY PERIODS ARE LIKELY BETWEEN SYSTEMS WHICH
CANNOT BE TIMED OUT. SOME MODELS...ESPECIALLY THE GFS...ARE TRYING TO DIG A
COLDER AIR MASS INTO THE AREA BY NEXT WEEKEND. THE ECMWF HAS BEEN RELUCTANT
TO BRING THE COLDER AIR INTO WRN WA. STUCK WITH RAIN FOR THE LOWLANDS BUT
SNOW LEVELS COULD BE QUITE LOW LOW BY SATURDAY...SOMETHING TO WATCH.
&&
.AVIATION...AN UPPER LOW NEAR CAPE FLATTERY WILL MOVE NE INTO SW
BRITISH COLUMBIA ON MONDAY. SOUTHWEST FLOW ALOFT. AT THE
SURFACE...HIGH PRESSURE OVER EASTERN WASHINGTON WILL GIVE LIGHT LOW
LEVEL OFFSHORE FLOW.
MOISTURE OVER THE INTERIOR...MAINLY SOUTH OF KPAE...WILL SLOWLY
SHIFT NW ACROSS THE AREA TONIGHT INTO MONDAY MORNING. THE AIR MASS
IS COLD ENOUGH THIS EVENING THAT PRECIPITATION WILL MAINLY BE IN
THE FORM OF SNOW OVER THE INTERIOR TONIGHT. SOME WARMING ALOFT MAY
CHANGE PRECIPITATION TO FREEZING RAIN OR SLEET FROM KSHN-KTCM
SOUTHWARD AFTER 08Z. PRECIPITATION TYPE WILL CHANGE TO ALL RAIN
ACROSS THE AREA BETWEEN 12Z-15Z.
SHORT TERM MODELS ARE SHOWING A GOOD DEAL OF UNCERTAINTY ON
PRECIPITATION AMOUNTS TONIGHT. THE HOURLY UPDATED HRRR SOLUTIONS
SHOW LIGHT PRECIPITATION AMOUNTS NORTH OF KOLM WITH SNOW ACCUMULATIONS
AT KPAE...KSEA AND KBFI TRACE TO 0.5 INCHES. KOLM WILL LIKELY SEE 1-2
INCHES OF SNOW AND MAY SEE SOME FREEZING RAIN LATE TONIGHT OR EARLY
MONDAY MORNING. EXPECT KBLI...KCLM...KUIL AND KHQM TO SEE SPRINKLES
OR FLURRIES WITH NO ACCUMULATIONS. IN THE INTERIOR FROM KPAE
SOUTHWARD EXPECT IFR VIS AND CIG CONDITIONS AT TIMES THROUGH 15Z
MON. VFR CONDITIONS EXPECTED ON THE COAST AND N OF KPAE. ALBRECHT
KSEA...BASED ON RADAR AND CONSENSUS OF SHORT TERM MODEL
SOLUTIONS...EXPECT VERY LIGHT SNOW AT TIMES TONIGHT. 2 MODEL
SOLUTIONS SHOW MORE SIGNIFICANT ACCUMULATIONS OF 1-2 INCHES BY 15Z.
AT THIS TIME...WILL FOLLOW MAJORITY OF MODELS. EXPECT TEMPERATURES
TO REMAIN ABOVE FREEZING UNTIL PRECIPITATION TURNS TO RAIN 15Z MONDAY
MORNING. ACCUMULATIONS...TRACE TO 0.5 INCHES. MVFR CIGS AND VIS
FALLING TO IFR AT TIMES WITH HEAVIER PRECIPITATION. NE WIND 5-8 KT
BECOMING LIGHT AFTER 12Z. ALBRECHT
&&
.MARINE...SOUTHEASTERLY PRESSURE GRADIENTS WILL DOMINATE FOR THE
NEXT SEVERAL DAYS AS HIGH PRESSURE REMAINS EAST OF THE CASCADES
AND A SERIES OF SYSTEMS MOVE NORTH THROUGH THE OFFSHORE WATERS.
SMALL CRAFT ADVISORY CONDITIONS CAN BE EXPECTED AT TIMES...MAINLY
OVER THE COASTAL WATERS AND AT THE WEST ENTRANCE TO THE STRAIT OF
JUAN DE FUCA.
WEST SWELL 10 TO 15 FEET WILL MOVE INTO THE WATERS TUESDAY OR
TUESDAY NIGHT AND WILL PERSIST THROUGH THURSDAY. ALBRECHT
&&
.HYDROLOGY...FLOODING IS NOT EXPECTED FOR THE NEXT 7 DAYS.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY IN EFFECT THROUGH 6 AM PST FOR THE
SOUTHWEST INTERIOR...TACOMA AND VICINITY...EAST PUGET SOUND
LOWLANDS...AND BREMERTON/HOOD CANAL AND VICINITY.
PZ...SMALL CRAFT ADVISORY UNTIL 9 PM PST THIS EVENING FOR CENTRAL
U.S. WATERS STRAIT OF JUAN DE FUCA-COASTAL WATERS FROM CAPE
FLATTERY TO JAMES ISLAND OUT 10 NM-WEST ENTRANCE U.S.
WATERS STRAIT OF JUAN DE FUCA.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
940 PM CST SUN JAN 3 2016
.UPDATE...-SHSN HAVE DEVELOPED OVER WEST CENTRAL WI...AND ARE
MOVING SOUTH. WL CARRY SOME -SHSN INTO WESTERN CWA NEXT SEVERAL
HOURS. OTHERWISE...MESOSCALE MODELS INCLUDING HRRR AND RAP BRING
UPSTREAM LOW PRESSURE TROUGH OVER NORTHERN LAKE MI AND UPPER MI
RAPIDLY SOUTHWARD OVERNIGHT. TROUGH BEGINS TO AFFECT SHEBOYGAN
COUNTY AREA AFTER 10Z WITH MODERATE LOW LEVEL OMEGA AND INCREASING
LOW LEVEL MOISTURE FLUX CONVERGENCE. HENCE ADDED POPS TO FAR
NORTHEAST CWA LATE TONIGHT AND BEEFED UP POPS FARTHER SOUTH OVER
LAKESHORE COUNTIES THROUGH MID-MORNING MON. SHEBOYGAN AND OZAUKEE
COUNTIES MAY EXPERIENCE SOME VISIBILITY RESTRICTIONS FROM SHSN
EARLY IN THE MORNING. SCT TO NMRS SHSN STILL EXPECTED OVER
LAKESHORE COUNTIES ON MON AS LOW PRESSURE TROUGH MOVES THROUGH.
DESPITE LOWERING RH IN THE 850-700MB LAYER...INVERSION REMAINS
AROUND 4-5K FT AS THE LOW LEVEL WINDS VEER TO THE NORTHEAST AND
REMAIN NORTHEAST THROUGH THE LATE MORNING AND AFTERNOON AS THE
WINDS DIMINISH. MAY BE ABLE TO LOWER POPS IN THE AFTERNOON AS THE
SCT -SHSN DIMINISH. SOME LOCATIONS MAY RECEIVE A QUICK INCH MONDAY
MORNING.
&&
.AVIATION/06Z TAFS/...AREA OF CLEARING OVER EASTERN CWA SHOULD
FILL IN WITH MOSTLY VFR CLOUDS OVERNIGHT. EXPECT CIGS TO LOWER TO
MVFR LATE TNGT OR EARLY MONDAY MORNING IN THE EAST AS LOW PRESSURE
TROUGH MOVES THROUGH. KMSN MAY BE AFFECTED BY SOME -SHSN NEXT FEW
HOURS THAT DEVELOPED OVER WEST CENTRAL WI AND ARE MOVING SOUTH.
OTRW...A FEW FLURRIES WILL BE POSSIBLE AT KMSN. SNOW SHOWERS STILL
LOOK TO AFFECT KMKE AND KENW BEGINNING MONDAY MORNING...TAPERING
OFF MON AFTN OR EVE.
&&
.MARINE...POSTPONED START TIME OF SMALL CRAFT ADVISORY UNTIL 06Z
AS FREQUENT GUSTS OF 22 KNOTS OR MORE NOT EXPECTED UNTIL LATER
TONIGHT. LOW PRESSURE TROUGH NOW OVER FAR NORTHERN LAKE MICHIGAN
WILL BE SLIDING RAPIDLY SOUTHWARD AND WILL START TO MOVE THROUGH
NEAR SHORE WATERS FROM 11Z THROUGH 15Z...WHICH IS A BIT FASTER
THAN EARLIER EXPECTED. SNOW SHOWERS WILL ACCOMPANY THE TROUGH
PASSAGE.
&&
.PREV DISCUSSION... /ISSUED 340 PM CST SUN JAN 3 2016/
SHORT TERM...
TONIGHT AND MONDAY...FORECAST CONFIDENCE IS MEDIUM.
AREA OF LIGHT SNOW SHOWERS AND FLURRIES CONTINUES TO AFFECT THE AREA
THIS AFTERNOON. THIS IS DUE TO SATURATED LOW LEVELS WITHIN DENDRITE
SNOW CRYSTAL GROWTH ZONE AND STEEP LOW LEVEL LAPSE RATES. PASSING
500 MB SHORTWAVE TROUGH HELPING SOMEWHAT AS WELL. THIS ACTIVITY IS
EXPECTED TO LINGER UNTIL AROUND 00Z MONDAY...BEFORE DISSIPATING OR
MOVING OFF TO THE SOUTHEAST OF THE AREA. A DUSTING OF ACCUMULATION
IS POSSIBLE WITHIN ANY OF THE LIGHT SNOW SHOWER BANDS.
STRATUS CLOUD DECK SHOULD REMAIN OVER THE AREA TONIGHT INTO MONDAY
MORNING. THERE MAY BE SOME PARTIAL MIXING OUT OF THIS DECK ACROSS
PORTIONS OF THE AREA AT TIMES...BUT NOT ENOUGH CONFIDENCE TO LOWER
SKY COVER AT THIS TIME.
GIVEN THE CLOUDS EXPECTED TONIGHT INTO MONDAY MORNING...RAISED LOW
TEMPERATURES INTO THE UPPER TEENS TO LOWER 20S. THESE MAY NEED TO
BE BROUGHT UP FURTHER.
CONFIDENCE IS A BIT HIGHER WITH REGARDS TO LIGHT LAKE EFFECT SNOW
SHOWERS FOR MONDAY NEAR LAKE MICHIGAN. THE BEST SHOT FOR LIGHT LAKE
EFFECT SNOW SHOWERS WILL BE IN SOUTHEAST MILWAUKEE...AND EASTERN
RACINE AND KENOSHA COUNTIES. MESOSCALE MODELS ARE SUGGESTING THAT
SOME KIND OF ELONGATED SINGULAR LAKE EFFECT SNOW BAND WILL TRAVERSE
SOUTHWESTWARD INTO THAT AREA MONDAY MORNING AND LINGER INTO THE
EARLY TO MID AFTERNOON PERIOD. SOME LIGHT SNOW SHOWERS MAY AFFECT
THE SHORELINE AREAS TO THE NORTH AS WELL.
DELTA T VALUES AND NORTHEAST FETCH REMAIN FAVORABLE...THOUGH ALL
MOISTURE REMAINS BELOW THE INVERSION LEVEL OF 850 MB. LAKE EFFECT
FLOW CHART SUGGESTS MINOR ACCUMULATIONS OF UNDER AN INCH POSSIBLE
WITH THE EXPECTED CONDITIONS...MAINLY IN THE SOUTHEAST MILWAUKEE
COUNTY...AND EASTERN RACINE AND KENOSHA COUNTY AREAS. HIGH POPS FOR
THIS AREA LOOKS REASONABLE...WITH LOWER POPS FOR THE REST OF THE
LAKESHORE AREAS.
MONDAY NIGHT AND TUESDAY...FORECAST CONFIDENCE HIGH
THE MID/UPPER FLOW BECOMES MORE ZONAL AND WEAKENS AS THE PLAINS
RIDGE FLATTENS AND MOVES ACROSS MUCH OF WISCONSIN. THE 850/700 MB
RIDGE MOVES TO THE EAST LATER TUESDAY WITH A SOUTHWEST FLOW AND
WARM AIR ADVECTION. WEAK UPWARD MOTION BEGINS BUT THE MID LAYERS
REMAIN DRY BUT LAYERS ABOVE 500 MB SATURATE LATER TUESDAY.
THE SURFACE HIGH MOVES ACROSS THE GREAT LAKES MONDAY NIGHT AND
OVER THE EASTERN U.S. LATER TUESDAY BEGINNING A SOUTH LOW LEVEL
FLOW AND MODERATION IN TEMPERATURES TO SOUTHERN WISCONSIN.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE HIGH
THE UPPER FLOW BECOMES MORE SOUTHWEST WITH A VERY WEAK SHORTWAVE
APPROACHING SOUTHERN WISCONSIN LATE WEDNESDAY. WEAK 700 MB UPWARD
MOTION CONTINUES. FORECAST SOUNDINGS SHOW THE MID LEVEL SATURATION
SLOWLY LOWERS TO AROUND 700 MB MAINLY WEST OF MADISON WEDNESDAY
AFTERNOON. MOST OF THE MODELS ARE DRY WITH AROUND A HUNDREDTH OF
AN INCH OF PRECIPITATION JUST WEST OF THE MISSISSIPPI RIVER
THROUGH THE AFTERNOON.
LONG TERM...
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH
THE WEAK SOUTHWEST UPPER FLOW INCREASES A LITTLE WITH THE VERY
WEAK SHORTWAVE MOVING ACROSS SOUTHERN WISCONSIN BY THURSDAY
MORNING WHILE THE MAIN SHORTWAVE TROUGH MOVES INTO THE HIGH
PLAINS WITH THE WEAK RIDGE AHEAD OF THE TROUGH MOVING INTO
SOUTHERN WISCONSIN.
THE SOUTH LOW LEVEL FLOW MOISTENS AND LIGHT PRECIPITATION AFFECTS
SOUTHERN WISCONSIN. THE GFS FORECAST SOUNDINGS INDICATE MAINLY
SNOW INITIALLY WITH SOME FREEZING RAIN POTENTIAL OR RAIN SNOW MIX
SOUTH LATER THURSDAY.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
A SHORTWAVE PUSHES INTO AND ACROSS WISCONSIN DURING THIS TIME
FRAME WHICH IS A LITTLE FASTER ON THE 00Z ECMWF.
LOW PRESSURE EXITS THE KANSAS/OKLAHOMA REGION FRIDAY AS IT TRACKS
TOWARDS SOUTHERN WISCONSIN SATURDAY ON THE GFS...WITH THE FASTER 00Z
ECMWF EXITING WISCONSIN.
ON THE GFS THE PRECIPITATION TRENDS TOWARD RAIN BEFORE COOLING
AGAIN WHEN THE UPPER LOW MOVES ACROSS SATURDAY.
SUNDAY...FORECAST CONFIDENCE IS MEDIUM.
THE MID/UPPER TROUGH MOVES OFF TO THE EAST WITH A MORE ZONAL FLOW
DEVELOPING.
A COLD NORTHWEST FLOW OCCURS IN THE LOW LEVELS WITH A STRONG
RIDGE OF HIGH PRESSURE OVER THE NORTHERN PLAINS.
AVIATION/00Z TAFS/...
LIGHT SNOW SHOWERS AND FLURRIES WILL CONTINUE ACROSS TAF SITES UNTIL
AROUND 00Z MONDAY...AS A TROUGH OF LOW PRESSURE MOVES THROUGH. A
DUSTING OF ACCUMULATION IS POSSIBLE IN ANY OF THE LIGHT SNOW BANDS
MOVING THROUGH.
MVFR CATEGORY CEILINGS ABOVE 2000 FEET ABOVE GROUND LEVEL MAY GO UP
TO AROUND 3000 FEET BY 00Z MONDAY. UPSTREAM OBSERVATIONS ARE GOING
INTO VFR CATEGORY WITH THE CEILINGS...AND SOME OF THESE MAY MOVE
INTO TAF SITES THIS EVENING. SOME UNCERTAINTY WITH THIS...SO WENT
NEAR 3000 FEET BY 00Z MONDAY FOR NOW.
NORTHWEST TO NORTH WINDS WILL BECOME GUSTY AT TIMES TONIGHT INTO
MONDAY MORNING...VEERING NORTHEAST AND WEAKENING IN THE AFTERNOON AT
MILWAUKEE AND KENOSHA.
LIGHT LAKE EFFECT SNOW SHOWERS WILL AFFECT KENOSHA AND MILWAUKEE AT
TIMES AFTER 15Z MONDAY MORNING INTO THE AFTERNOON. KENOSHA WILL HAVE
THE BEST CHANCES. LIGHT SNOW ACCUMULATIONS OF UNDER AN INCH ARE
EXPECTED AT KENOSHA AND MILWAUKEE. WAUKESHA IS QUESTIONABLE FOR ANY
SNOW ACCUMULATIONS...MOSTLY REMAINING EAST OF THERE. SNOW RATES WILL
BE VERY LIGHT...AROUND A TENTH OF AN INCH PER HOUR.
FOR NOW...WILL MENTION LIGHT SNOW SHOWERS IN KENOSHA AND MILWAUKEE
TAFS...AND LEAVE THEM OUT OF WAUKESHA DUE TO UNCERTAINTY WITH TIMING
AND PLACEMENT OF THESE LIGHT SNOW SHOWERS. MVFR TO POSSIBLY IFR
CATEGORY CEILINGS AND VISIBILITIES ARE POSSIBLE WITH THE SNOW
SHOWERS...BEST SHOT AGAIN WILL BE AT KENOSHA.
MARINE...
THE NORTHWEST TO NORTH WINDS WILL BECOME GUSTY TONIGHT INTO MONDAY
MORNING...AS THE PRESSURE GRADIENT TIGHTENS ONCE AGAIN. SHOULD SEE
25 KNOT GUSTS OCCUR LATER THIS EVENING AND INTO MONDAY MORNING...AS
WINDS GRADUALLY VEER NORTH TO NORTHEAST BY THE AFTERNOON. HIGH WAVES
OVER 4 FEET SHOULD DEVELOP AS WELL DURING THIS TIME...ESPECIALLY
SOUTH OF NORTH POINT LIGHTHOUSE. THUS...A SMALL CRAFT ADVISORY HAS
BEEN ISSUED FROM 03Z TO 18Z MONDAY NORTH OF NORTHPOINT
LIGHTHOUSE...AND FROM 03Z TO 21Z SOUTH OF THERE. SOME FREEZING SPRAY
IS ALSO POSSIBLE WITH THE HIGHER WAVE ACTION LATER TONIGHT AND EARLY
MONDAY...MAINLY TOWARD THE OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 3 PM CST MONDAY FOR LMZ645-646.
SMALL CRAFT ADVISORY UNTIL NOON CST MONDAY FOR LMZ643-644.
&&
$$
UPDATE...MBK
TONIGHT/MONDAY AND AVIATION/MARINE...WOOD
MONDAY NIGHT THROUGH SUNDAY...HENTZ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
923 PM MST SUN JAN 3 2016
.SYNOPSIS...
CLOUDS WILL THICKEN GOING INTO TONIGHT AHEAD OF THE FIRST OF SEVERAL
STORM SYSTEMS EXPECTED TO MOVE THROUGH THE REGION. THESE STORM
SYSTEMS WILL BRING COOLER AFTERNOON HIGHS AND MILD NIGHTS THROUGHOUT
THE WEEK...FREQUENT CLOUDY SKIES...WHILE ALSO PROVIDING SEVERAL
PERIODS OF LIGHT TO MODERATE RAINFALL. CONDITIONS WILL START TO DRY
OUT FOR THE COMING WEEKEND...BUT TEMPERATURES WILL REMAIN BELOW
SEASONAL NORMALS.
&&
.DISCUSSION...
LATEST WATER VAPOR IMAGERY SHOWS A WELL-DEFINED VORT MAX NEAR 30N
120W...OR ROUGHLY 300 MILES SOUTHWEST OF SAN DIEGO. MID AND HIGH
CLOUDS CONTINUE TO OVERSPREAD THE DESERT SOUTHWEST AHEAD OF THE
TROUGH. LATEST MRMS SHOWS SOME SPRINKLES OR EVEN LIGHT SHOWER
ACTIVITY BACKBUILDING INTO THE PHOENIX AREA. FURTHER WEST ACROSS THE
IMPERIAL VALLEY...RADAR IS DETECTING SOME LIGHT ECHOES NEAR EL
CENTRO. ADDITIONAL SPRINKLES ARE POSSIBLE OVERNIGHT IN THESE AREAS...THOUGH
LATEST RUNS OF THE HRRR SUGGEST THAT THE MORE ORGANIZED ACTIVITY WILL
REACH IMPERIAL COUNTY AROUND 4 AM WITH SCATTERED SHOWERS DEVELOPING
ACROSS SOUTH-CENTRAL AZ DURING THE EARLY TO LATE MORNING. ATMOSPHERIC
RIVER IS THEN EXPECTED TO WEAKEN AS IT REACHES THE COAST...THOUGH
MOISTURE TRANSPORT MAGNITUDES AND ORIENTATION WILL REMAIN FAVORABLE
FOR ADDITIONAL PRECIPITATION DURING THE AFTERNOON. FORECAST REMAINS
IN GOOD SHAPE. ONLY MINOR SHORT-TERM ADJUSTMENTS WERE MADE TO THE
TEMPERATURES AND DEWPOINTS.
&&
.PREVIOUS DISCUSSION... THE LONG ANTICIPATED FIRST EL NINO
INFLUENCED RAIN IS NEARLY HERE AS THE FIRST OF SEVERAL LOW PRESSURE
SYSTEMS IS NEARING THE CALIFORNIA COAST. THE CURRENT SET UP SHOWS A
DEEP TROUGH SITUATED OFF THE WEST COAST WITH TWO DISTINCT CIRCULATION
CENTERS...THE DEEPER BUT WEAKENING CLOSED LOW OFF THE NORTHERN
CALIFORNIA COAST AND ANOTHER THAT IS AN OPEN WAVE OFF THE NORTHERN
BAJA COAST BUT IS STARTING BECOME MORE ORGANIZED ON THE NOSE OF A
140+ KT UPPER JET. AS THIS SOUTHERN WAVE MOVES THROUGH NORTHERN BAJA
TONIGHT...STRONG SOUTHERLY FLOW AHEAD OF IT WILL START TO PULL
MOISTURE NORTHWARD INTO THE DESERT SOUTHWEST. AM STILL CONFIDENT
SHOWERS WILL BEGIN TO DEVELOP LATE TONIGHT ACROSS SOUTHERN ARIZONA
AND THEN INCREASE IN COVERAGE THROUGH THE DAY WITH MUCH OF THE AREA
SEEING AT LEAST A TENTH OF AN INCH OF RAIN AND SOME LOCALIZED AMOUNTS
AROUND A HALF AN INCH.
AS THE FIRST WAVE DAMPENS AND LIFTS INTO THE GREAT BASIN TUESDAY
MORNING...SOME MEASURE OF SHORTWAVE RIDGING AND SUBSIDENCE WILL
SPREAD INTO THE FORECAST AREA DURING THE DAYLIGHT HOURS. AN
OROGRAPHIC UPSLOPE COMPONENT WILL STILL PREVAIL EAST OF THE PHOENIX
METRO AND GIVEN THE MOIST ENVIRONMENT...A FEW LIGHT SHOWERS WILL
LIKELY BE SQUEEZED OUT OVER HIGHER TERRAIN. OTHERWISE...THE NEXT
PROGRESSIVE SHORTWAVE AND ASSOCIATED FRONTAL BAND WILL CRASH INTO
SRN CALIFORNIA TUESDAY AFTERNOON WITH MOISTURE SPILLING INLAND
TUESDAY NIGHT.
BOTH OPERATIONAL AND ENSEMBLE MEMBERS INDICATE THE ARRIVAL OF THE
SECOND SHORTWAVE AND FRONTAL BOUNDARY EARLY WEDNESDAY SUCH THAT
SHOWERS IN A STRONGLY FORCED ENVIRONMENT WILL SPREAD ACROSS THE CWA
PRIMARILY DURING THE OVERNIGHT AND MORNING TIME FRAME. ONCE AGAIN...A
FAVORABLE OROGRAPHIC COMPONENT WILL EXIST UNDER A DIVERGENT JET
STRUCTURE AND SAW LITTLE REASON NOT TO INCREASE POPS ON THE NORTHERN
AND EASTERN PERIPHERY OF THE FORECAST AREA DURING THE DAY WEDNESDAY.
DESPITE LESS THAN OPTIMAL WV TRANSPORT FROM THE SUBTROPICS...RAINFALL
MAY STILL BE EFFICIENT GIVEN PWATS IN EXCESS OF 0.75 INCHES AND THE
PROLONGED STRONG DYNAMICAL FORCING.
THE THIRD WAVE WILL FOLLOW QUICKLY ON THE HEELS OF THE SECOND WEDNESDAY
NIGHT AND THURSDAY WITH COLDER AIR ALOFT THAN THE PREVIOUS TWO
WAVES. AT THIS POINT...THE FORECAST BECOMES FAR MORE UNCERTAIN AND
COMPLICATED AS ENSEMBLE MEMBER SPREAD INCREASES REGARDING
TIMING...TRAJECTORIES...AND DEPTHS OF THE FINAL TWO SHORTWAVES
THURSDAY AND FRIDAY. IMPACTS FROM THESE WAVES MAY ALSO BECOME
CRITICAL AS SNOW LEVELS MAY EASILY DROP BELOW 4500FT...NOT TO MENTION
STEEPENING MIDLEVEL LAPSE RATES WITH THE COLDER AIR ALOFT (I.E.
THUNDERSTORM POTENTIAL). A CURSORY LOOK AT ENSEMBLE OUTPUT SEEMS TO
FAVOR A SLIGHTLY LESS PROGRESSIVE SOLUTION THAN THE OPERATIONAL
ECMWF...BUT ALSO AN OUTCOME NOT QUITE AS INTENSE/DEEP AS THE
OPERATIONAL GFS. GIVEN THESE TENDENCIES...HAVE KEPT POPS RATHER
INFLATED WITH THE OVERALL PATTERN...BUT WILL REFRAIN FROM HITTING
STRONGLY ON POTENTIALLY BIGGER IMPACTS UNTIL SOME MEASURE OF MODEL
CONSISTENCY CAN BE ACHIEVED.
A BREAK IN THE ACTIVE WEATHER PATTERN FOR THE SWRN CONUS SHOULD
FINALLY ARRIVE SATURDAY AS ENSEMBLE OUTPUT INDICATES MORE OF A
POSITIVE PNA PATTERN DEVELOPING FOR NORTH AMERICA (AS WOULD BE
COMMON GIVEN THE MJO SIGNAL MOVING INTO THE WEST HEMISPHERE/AFRICA
PHASE SPACE). THE SOUTHWEST REGION WILL STILL REMAIN UNDER SOME
MEASURE OF NWLY FLOW WITH COOL BOUNDARY LAYER AIR FILTERING SOUTH
FROM THE GREAT BASIN. REGARDLESS BY THIS TIME DESPITE THE CONTINUED
COOL TEMPERATURES...DRY SUNNY WEATHER MAY BE A WELCOME SIGHT.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
A LOW PRESSURE SYSTEM WILL BRING SHOWERS AND LOWER CIGS TO THE
PHOENIX AREA MONDAY. CIGS WILL CONTINUE TO LOWER WITH SHOWERS
BECOMING MORE WIDESPREAD AFTER 14Z MONDAY. CIGS WILL LIKELY DROP TO
AS LOW AS 4K FT MONDAY AFTERNOON. LATEST MODEL GUIDANCE SUGGESTS MVFR
CIGS COULD PERSIST THROUGH MONDAY NIGHT AS WELL.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND
KBLH...
SCATTERED SHOWERS ARE EXPECTED TO BECOME MORE WIDESPREAD AROUND 12Z
AT KIPL AND AROUND 14Z AT KBLH. CIGS WILL LIKELY BE LOWER AT KBLH
THAN AT KIPL...POSSIBLY AS LOW AS 4K FT BY AFTERNOON.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
SEVERAL WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICTS IN CLOSE
SUCCESSION THIS WEEK WITH HIGHLY VARIABLE RAINFALL OCCURRING EACH
DAY THROUGH FRIDAY...MAINLY EAST OF THE LOWER COLORADO RIVER VALLEY.
RAIN CHANCES TAPER OFF FOR SATURDAY. HUMIDITY WILL BE MUCH ABOVE
AVERAGE WITH MINIMUM VALUES NEAR AND ABOVE 40 PERCENT MOST DAYS ON
THE LOWER DESERTS AND MAX VALUES NEAR AND ABOVE 80 PERCENT MUCH OF
THE TIME. VALUES TREND DOWN SIGNIFICANTLY FROM WEST TO EAST ON
SATURDAY. DESPITE THE ACTIVE WEATHER PATTERN NO STRONG WIND EVENTS
ARE EXPECTED BUT JUST BREEZY AT TIMES...MAINLY WEDNESDAY AND
THURSDAY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...KUHLMAN/MO
AVIATION...HIRSCH
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS TUCSON AZ
914 PM MST SUN JAN 3 2016
.SYNOPSIS...A SERIES OF WET STORM SYSTEMS WILL BRING VALLEY
RAIN...MOUNTAIN SNOW AND COOLER TEMPERATURES THIS WEEK.
&&
.DISCUSSION...WATER VAPOR IMAGERY AND 04/00Z UPPER-AIR PLOTS SHOW
RIDGING TO OUR EAST OVER WEST TEXAS AND NEW MEXICO...WITH AN
APPROACHING PACIFIC TROUGH CURRENTLY JUST OFFSHORE OF THE SOUTHERN
CALIFORNIA AND NORTHERN BAJA COASTS. LIGHTNING DETECTION SHOWING
SOME CONVECTION WEST OF THE NORTHERN BAJA COAST AT THIS TIME. IR
SATELLITE IMAGERY SHOWS EXTENSIVE CLOUDINESS COVERING JUST ABOUT ALL
OF THE WESTERN STATES IN SOME FORM. RADAR MOSAIC SHOWS SOME ISOLATED
RETURNS MOVING ACROSS THE NORTHERN BAJA PENINSULA AND HEADED FOR
SOUTHWEST ARIZONA.
MODELS GENERALLY IN AGREEMENT IN SHOWING SHOWERS BEGINNING TO AFFECT
MY FORECAST AREA SHORTLY AFTER SUNRISE AND MAINLY OUT WEST TOWARD
THE AJO AREA...INITIALLY. AS THE MORNING PROGRESSES THIS BAND OF
SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WILL CONTINUE TO MARCH
EAST REACHING THE TUCSON AREA AROUND LATE MORNING INTO THE EARLY
AFTERNOON HOURS. THIS SCENARIO IS ALREADY DEPICTED WELL IN THE
INHERITED POP GRIDS...SO NO CHANGES ARE PLANNED AT THIS TIME. POP
GRIDS DURING THE REMAINDER OF THE EVENING AND INTO THE OVERNIGHT
HOURS JUST SHOW SLIGHT CHANCES AFTER MIDNIGHT AND MOSTLY OVER THE
FAR WESTERN DESERTS NEAR AJO AND ORGAN PIPE CACTUS NATIONAL
MONUMENT...WITH THE THREAT FOR SHOWERS RAMPING UP SIGNIFICANTLY
AFTER SUNRISE AS THE AFOREMENTIONED LINE OF SHOWERS AND/OR
THUNDERSTORMS PUSHES EAST.
AS OF 04Z (9 PM MST)...TEMPERATURES ACROSS THE REGION RANGED FROM
THE LOWER 40S TO THE MID 60S...WITH THE TUCSON INTL AIRPORT
REPORTING A TEMP OF 61 DEGS...AFTER ACHIEVING AN AFTERNOON HIGH OF
70 DEGS...WHICH WAS 6 DEGS ABOVE NORMAL FOR THIS DATE. THESE TEMP
READINGS SEEM TO BE ON TRACK WITH EXPECTED OVERNIGHT LOW TEMPS...SO
NO CHANGES ARE PLANNED BUT WILL CONTINUE TO MONITOR.
SEE THE PREVIOUS DISCUSSION BELOW FOR DETAILS REGARDING THE WEATHER
THROUGHOUT THE WEEK.
&&
.AVIATION...VALID THRU 05/06Z.
EXPECT INCREASING CLOUDS AND LOWERING CLOUD DECKS THROUGH THE REST
OF THE FORECAST PERIOD. SCT-BKN CLOUDS AT 8-12K FT AGL AND BKN-OVC
CLOUDS AT 12-16K FT AGL BY 04/12Z...AND THEN BKN-OVC CLOUDS AT 4-7K
FT AGL BY 04/23Z. SCATTERED VALLEY -SHRA AND MOUNTAIN -SHSN
DEVELOPING AFT 04/15Z...BECOMING NUMEROUS BY 04/21Z WITH LOCAL MVFR
CONDITIONS AND MOUNTAIN OBSCURATIONS. ELY/SELY SURFACE WIND AT 7-15
KTS...WITH GUSTS BETWEEN 15-20 KTS THRU 04/03Z. ELY/SELY SURFACE
WIND WILL THEN DECREASE TO 12 KTS OR LESS AFT 04/03Z. SELY/SLY
SURFACE WIND AT 10-15 KTS AFT 04/20Z. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DRY CONDITIONS WITH LOCALLY GUSTY EAST WINDS WILL
CONTINUE THROUGH THE EVENING HOURS TONIGHT. THERE WILL THEN BE A BIG
CHANGE IN THE WEATHER PATTERN THIS WEEK...WITH PERIODS OF VALLEY
RAIN AND MOUNTAIN SNOW...AND MUCH COOLER TEMPERATURES MONDAY THROUGH
FRIDAY. LINGERING SHOWERS WILL OCCUR MAINLY EAST OF TUCSON SATURDAY
FOLLOWED BY DRY CONDITIONS AREA-WIDE NEXT SUNDAY.
&&
.PREV DISCUSSION...SOME MOISTURE INCREASE ALREADY OCCURRING IN THE
STRENGTHENING SOUTHWESTERLY FLOW (BEHIND THE RIDGE AMPLIFYING
IMMEDIATELY DOWNSTREAM AND AHEAD OF THE FIRST IN A SERIES OF WET
PACIFIC STORMS THIS WEEK). 12Z KTWC SOUNDING WAS UP TO 1/2 INCH
PRECIPITABLE WATER WITH 3/4 INCH VALUES ALREADY BREACHING THE
SIERRAS OF SOUTHERN CALIFORNIA AND NORTHERN BAJA CIRA LAYERED PW
IMAGERY. LATEST HRRR TRENDS SHOW INCREASING SURFACE DEW POINTS FROM
THE NORTHERN GULF OF CALIFORNIA INTO LOWER WESTERN DESERTS OVER THE
NEXT 15 HOURS.
CONFIDENCE REMAINS VERY HIGH FOR A SERIES OF WET-TRAJECTORY STORMS
FROM THE PACIFIC WITH POTENTIALLY SIGNIFICANT VALLEY RAIN AND
MOUNTAIN SNOW AMOUNTS THIS COMING WEEK. JUDGING BY OPERATIONAL MODEL
BLENDS AS WELL AS ENSEMBLE MEANS...THE INITIAL IMPULSE WILL HAVE THE
GREATEST IMPACT ON OUR PART OF THE STATE FROM MONDAY AFTERNOON INTO
TUESDAY MORNING. FOLLOWING THAT...THE BEST PERIODS FOR OUR PART OF
THE STATE APPEAR TO BE WEDNESDAY...THURSDAY NIGHT AND FRIDAY
AFTERNOON INTO SATURDAY MORNING.
AS MENTIONED ABOVE OUR AVAILABLE MOISTURE SHOULD BE PLENTIFUL WITH
RELATIVELY EFFICIENT PRECIPITATION PROCESSES. FOR THE ENTIRE MONDAY
THROUGH FRIDAY PERIOD WE CONTINUE TO INCREASE OUR QPF VALUES WITH
CONSERVATIVE ESTIMATES OF 1/2 TO 1.25 INCHES IN VALLEYS AND 1 TO 2.5
INCHES IN MOUNTAINS. SNOW LEVELS ABOVE 7000 FEET FOR MOST OF THE
WEEK WITH SNOW AMOUNTS IN EXCESS OF 1 FT POSSIBLE AT HIGHER MOUNTAIN
LOCATIONS (AND WELL ABOVE THAT ON HIGHEST MOUNTAIN PEAKS).
THE LAST IMPULSE ON FRIDAY INTO SATURDAY MAY HAVE A HYBRID MOIST AND
COOLER TRAJECTORY FROM THE NORTHWEST. THAT WOULD MAKE FOR COOLER
TEMPERATURES AND LOWER SNOW LEVELS FRIDAY AND SATURDAY. THE ECMWF
HAS ANOTHER IMPULSE JUST NORTH OF THE AREA SUNDAY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
CURRENT DISCUSSION...MOLLERE
PREVIOUS DISCUSSION...MEYER/ZELL
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
343 AM CST MON JAN 4 2016
.SHORT TERM...
327 AM CST
THROUGH TUESDAY...
THE LAKE EFFECT SNOW IN THE FORECAST AREA TODAY STILL LOOKS LIKE
A GOOD POSSIBILITY AND THE MAIN FORECAST CHANGE WAS TO REFINE AND
HONE IN ON THE TIMING AND IMPACTS. REGARDING TIMING...THROUGH A
COMBINATION OF OBSERVATIONAL TRENDS AND HIGH-RESOLUTION GUIDANCE
HAVE SPED UP THE START TIME OF THE SNOW SHOWERS IN FAR NORTHEAST
ILLINOIS AND FAR NORTHWEST INDIANA AND ALSO LIMITED THE SNOW
SHOWER DURATION FROM PREVIOUS FORECAST. THIS DID RESULT IN LESS
AVERAGE FORECAST SNOWFALL TOTALS...THOUGH AS ALWAYS WITH LAKE
EFFECT SNOW SHOWERS THERE CAN BE A HIGH AMOUNT OF VARIABILITY OVER
SPACE. AROUND AN INCH IS FORECAST IN LAKE ADJACENT COUNTIES WITH
THE LIKELY POSSIBILITY OF LESS IN SOME SPOTS AND A LITTLE MORE IN
OTHERS. A DUSTING IS FORECAST IN THE SECOND TIER COUNTIES
SURROUNDING THE SOUTHERN PART OF THE LAKE.
THE UPPER AIR PATTERN EARLY THIS MORNING CONTINUES TO BE ONE OF
REINFORCING COLD AIR ALOFT OVER THE GREAT LAKES...WITH A 130KT DUE
SOUTHWARD POINTING JET ENTERING THE REGION. THE 850MB TEMPERATURES
ARE AROUND -13C OFFERING AROUND AN ESTIMATED 15C DIFFERENCE
BETWEEN THE 850MB AND LAKE SURFACE TEMPERATURES. THIS HAS
RESULTED IN BROAD SNOW SHOWERS ORIENTED INTO LOWER MICHIGAN AND
MAINLY LA PORTE COUNTY INDIANA THUS FAR.
AT THE SURFACE...A COLD FRONT IS ORIENTED NORTHWEST-TO-SOUTHEAST
OVER THE CENTRAL PART OF THE LAKE AHEAD OF AN ARCTIC HIGH THAT
WILL MODIFY AS IT CREEPS SOUTHWARD TODAY. PRESSURE RISES OF
4-5MB/3HR ARE PUSHING THE FRONT SOUTHWARD WITH MORE PRONOUNCED DRY
AIR BEHIND IT. ALONG THE BOUNDARY A LAKE-INDUCED CIRCULATION IS
PRESENT ON RADAR MOSAIC AND WIND STREAMLINE ANALYSIS OFF THE SHORE
OF LUDINGTON MICHIGAN. THIS FEATURE SHOULD CONTINUE SOUTHWARD DOWN
THE LAKE WITH THE SYNOPTIC BOUNDARY EARLY THIS MORNING ASSISTING
IS LOCALIZED CONVERGENCE AND LIKELY BRIEFLY ENHANCING SNOWFALL
RATES ON THE WESTERN FLANK WHICH RIGHT NOW IS EXPECTED TO CLIP FAR
NORTHEAST ILLINOIS AND INTO NORTHWEST INDIANA. A MORE PRONOUNCED
BAND OR COUPLE BANDS ARE STARTING TO DEVELOP UPSTREAM WITH THIS
AND SHOULD CONTINUE TO BETTER DEVELOP GIVEN THE FORECAST
CONVERGENCE AND SUGGESTED SOLUTIONS BY CONVECTIVE ALLOWING
GUIDANCE. LAKE-INDUCED CAPE AT THE LEADING EDGE OF THIS LOOKS TO
BE 100-200 J/KG WITH AN EQUILIBRIUM LEVEL AROUND 8000 FT PER
MODIFIED RAP AND NAM SOUNDINGS. THIS WILL LIKELY SUPPORT A BURST
OF MODERATE TO BRIEFLY HEAVY SNOW SHOWERS FOR SOME LOCATIONS
WHERE THIS COMES INLAND...ARRIVING BETWEEN 9-11 AM CURRENTLY
LOOKS LIKE THE BEST FORECAST TIME. HOWEVER THIS BAND/S/ LOOKS TO
HAVE A SNAKE-LIKE SHAPE AND BE FAIRLY PROGRESSIVE...THUS LIMITING
RESIDENCE TIME IN ANY ONE LOCATION AS THE FRONT AND MESOLOW PUSH
SOUTHWARD. SO WHILE A QUICK INCH OR A LITTLE OVER MAY OCCUR FOR
SOME...AMOUNTS AFTER THAT FIRST HOUR OR SO LOOK TO BE LESS. IT
ALSO LOOKS LIKE THE SNOW SHOULD SQUEEZE IN JUST BEHIND THE MORNING
COMMUTE...HELPING TO MINIMIZE IMPACTS SOME. WILL STILL LIKELY
ISSUE AN SPS JUST FOR THE POTENTIAL FOR A RAPID CHANGE IN
VISIBILITY EVEN IF BRIEF.
GOING INTO THE EARLY-MID AFTERNOON BEHIND THE FRONT...LESS
ORGANIZED SNOW SHOWERS OR FLURRIES WILL REMAIN WITH LIGHT
ADDITIONAL ACCUMULATION AS EQUILIBRIUM HEIGHTS LOWER ON A
STRENGTHENING SUBSIDENCE INVERSION. THE EXCEPTION MAY BE LAKE
COUNTY ILLINOIS AND NORTHERN COOK WHERE SOME CONVERGENCE WITH A
LONG FETCH IS FORECAST...SO RESIDENCE TIME OF LIGHT SNOW COULD
HELP TO YIELD AN ADDITIONAL HALF INCH OR MORE...BUT EVEN THAT
LOOKS TO WEAKEN THROUGH THE AFTERNOON AS DRY ADVECTION
STRENGTHENS.
HIGHS TODAY ARE FORECAST TO PEAK IN THE UPPER 20S IN MOST
LOCATIONS WITH GRADUALLY MORE SUNSHINE FORECAST IN THE AFTERNOON
AWAY FROM LAKE INDUCED CLOUDS. TONIGHT SHOULD SEE THE SKY CLEAR
IN MOST IF NOT ALL LOCATIONS. HAVE GONE TOWARD COOLER GFS-BASED
MOS GUIDANCE WITH WINDS DROPPING OFF AND SOME LOCATIONS HAVING A
TAD BIT OF FRESH SNOW. SOME UPPER SINGLE DIGITS ARE PROBABLY A
DECENT BET IN FAVORED COOLER LOCATIONS.
MTF
&&
.LONG TERM...
327 AM CST
TUESDAY NIGHT THROUGH SUNDAY...
A SLOW MODERATION CONTINUES TO BE FORECAST MIDWEEK WITH A
DAMPENING UPPER RIDGE SHIFTING EAST OVER THE AREA AND SOUTHWEST
850-1000MB FLOW DEVELOPING UNDERNEATH. THE BLOCKED PATTERN IN THE
WESTERN CONUS IS FORECAST TO BREAK DOWN WITH A STRONG WEST-TO-EAST
PACIFIC JET EXPANDING INTO SOUTHERN CALIFORNIA. A LEADING SHORT
WAVE EJECTING FROM THIS IS EXPECTED TO MOISTEN THE LOW-LEVEL FLOW
INTO THE MISSISSIPPI VALLEY REGION AND THAT STILL IS FORECAST
DURING LATER WEDNESDAY NIGHT INTO THURSDAY. WOULD NOT BE
SURPRISED TO SEE THIS SLOW DOWN A TAD. TEMPERATURES...
THICKNESSES...AND FORECAST PROFILES IN GENERAL STILL LOOK
SUPPORTIVE OF POTENTIALLY LIGHT SNOW OR A WINTRY MIX AT THE
LEADING EDGE OF SATURATED ASCENT.
THE MORE PRONOUNCED LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP
OVER THE CENTRAL PLAINS THURSDAY NIGHT INTO FRIDAY YIELDING DEEPER
MOISTURE TRANSPORT AND MORE WIDESPREAD LIFT WITHIN UPPER
DIFFLUENCE...ALL SUPPORTING LIKELY RAIN AT THIS JUNCTURE. THE LIFT
AND ESPECIALLY MOISTURE IS PRESENTLY NOT FORECAST TO THE MAGNITUDE
OF SEVERAL OF THE HEAVY RAIN DECEMBER SYSTEMS WE SAW...SO QPF IS
PRESENTLY BELOW AN INCH...BUT STILL ONE HALF TO THREE-QUARTERS OF
AN INCH OF RAIN IN JANUARY ON SATURATED GROUND IS NOTEWORTHY AND
SOMETHING WE WILL HAVE TO WATCH. THE 04.00 GFS CONTINUES JUST A
TAD FURTHER EAST AS DOES ITS ENSEMBLE COMPARED TO THE EC. IT WOULD
REQUIRE A FAIRLY LARGE SHIFT TO GET THE STRONGER COLD ADVECTION
WITH THIS SYSTEM GIVEN ITS SOMEWHAT BROAD NATURE...SO STILL FEEL
GOOD NOT MENTIONING ANY WINTERY PRECIPITATION CHANCES THURSDAY
NIGHT THROUGH FRIDAY NIGHT. EVEN DURING THE WEEKEND...WINTRY
PRECIPITATION PRESENTLY LOOKS TO BE LIGHT IF IT WERE TO
MATERIALIZE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* WINDS SHIFTING TO THE NORTHEAST LATE MORNING OR EARLY
AFTERNOON MONDAY WITH SPEEDS OF 10-12KT.
* LAKE EFFECT SNOW SHOWERS BEGINNING BY OR SHORTLY BEFORE NOON AND
PERSISTING INTO THE AFTERNOON. GENERALLY MVFR VIS LIKELY WITH
PERIODS OF VIS 1SM POSSIBLE. OCNL BRIEF PERIODS OF VIS LESS THAN
1SM POSSIBLE IN HEAVIER BANDS.
* MVFR CIGS LIKELY BY THE TIME OF SNOW ONSET AND CONTINUING INTO
EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 06Z...
SCT -SHSN HAVE PASSED THROUGH THE REGION THIS EVENING ASSOCIATED
WITH A MID LEVEL IMPULSE TRACKING ACROSS THE REGION. THERE IS A
CHANCE FOR BRIEF PERIODS OF VFR -SHSN UNTIL A COUPLE HOURS AFTER
MIDNIGHT...BUT CONDITIONS SHOULD REMAIN VFR.
OVERNIGHT...WINDS WILL GRADUALLY VEER FROM NWLY TO NELY AS HIGH
PRESSURE BUILDS ACROSS THE UPPER GREAT LAKES TO THE MIDDLE
MISSISSIPPI VALLEY. A WEAK PRESSURE GRADIENT OVER LAKE MICHIGAN
COMBINED WITH AN INFLUX OF COOLER AIR EXPECTED WHEN WINDS SHIFT
THROUGH NLY-NELY WILL SET UP A PATTERN CONDUCIVE TO LAKE EFFECT
SNOW. THE HIGH RESOLUTION MODEL GUIDANCE IS TRENDING TOWARD WHAT
THE LARGER SCALE MODELS HAD BEEN ADVERTISING...WITH A LAKE EFFECT
PLUME FORMING OVERNIGHT OVER THE ERN SIDE OF LAKE MICHIGAN AND
GRADUALLY MOVING TO THE WEST THROUGH THE EARLY MORNING HOURS. SNOW
SHOULD REACH GYY FIRST BY LATE MORNING AND THEN CONTINUE TO SHIFT
EAST...REACHING MDW/DPA/ORD BY LATE MORNING TO ARND NOON. THERE
IS SOME SUGGESTION THAT THE LAKE PLUME COULD BE IN A WEAKENING
PHASE AS THE PLUME REACHES THE CHICAGO AREA TERMINALS...BUT THE
LARGER SCALE SETUP SHOULD STILL BE CONDUCIVE TO BRING A PERIOD OF
LAKE EFFECT SNOW TO ORD/MDW. HAVE NOT MADE ANY SGFNT CHANGES TO
THE GOING FORECAST WITH RESPECT TO THE LAKE EFFECT SNOW AS EVEN
LIGHT SNOW CAN QUICKLY REDUCE VISIBILITY TO LOWER END MVFR OR IFR
LEVELS. WILL MAINTAIN THE PROB30 GROUP FOR 1SM AS ANY LAKE EFFECT
BAND THAT MANAGE TO REACH THE TERMINALS WOULD HAVE THE POTENTIAL
TO DROP VIS TO 1SM...OR POSSIBLY LESS...FOR AT LEAST BRIEF
PERIODS.
THE LARGE SCALE HIGH PRESSURE IS EXPECTED TO SAG ACROSS NERN
IL/SRN LAKE MICHIGAN/NRN INDIANA BY LATE AFTERNOON...SHUTTING OFF
THE LAKE EFFECT SNOW POTENTIAL AND SHIFTING WINDS TO SOUTHERLY.
MVFR CIGS SHOULD CONTINUE INTO THE EARLY EVENING...BUT AS THE HIGH
PRESSURE BUILDS ACROSS THE REGION...SKIES SHOULD QUICKLY SCATTER
OUT AND BECM MOSTLY CLEAR OVERNIGHT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM-HIGH CONFIDENCE IN TIMING OF LAKE EFFECT SNOW MONDAY.
LOW CONFIDENCE IN TIMING AND DURATION OF VIS DROPPING TO 1SM OR
LESS IN HEAVIER BANDS OF SNOW.
* MEDIUM-HIGH CONFIDENCE IN WIND AND CEILING TRENDS THROUGH THE
PERIOD.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...VFR. SOUTH WINDS.
WEDNESDAY...VFR. SOUTH WINDS.
THURSDAY...CHC OF A WINTER MIX CHANGING TO RA DURING THE
DAY. MVFR CIGS LIKELY. SOUTH WINDS BCMG SOUTHEAST OVERNIGHT.
FRIDAY...-RA LIKELY. VFR BCMG MVFR PERHAPS IFR OVERNIGHT. EAST
WINDS.
SATURDAY...CHC -RA BCMG -SN OVERNIGHT. MVFR WITH IFR PSBL. WEST
WINDS.
KJB
&&
.MARINE...
345 AM CST
MAIN MARINE CONCERN IN THE NEAR TERM IS A PERIOD OF NORTHWEST TO
NORTHEAST WINDS OF 20-25 KT WITH OCCASIONAL GUSTS TO 30
KT PRODUCING HAZARDOUS CONDITIONS FOR SMALL CRAFT ALONG BOTH THE
ILLINOIS AND INDIANA NEARSHORE WATERS THROUGH LATE THIS AFTERNOON
OR EARLY EVENING. WINDS WILL DIMINISH FAIRLY QUICKLY THIS EVENING
AS HIGH PRESSURE MOVES ACROSS THE LAKE THIS EVENING AND OVERNIGHT
TONIGHT.
WINDS WILL TURN TO THE SOUTH LATE TODAY NIGHT AS THE HIGH MOVES
OFF TO THE EAST... WITH THESE SOUTH WINDS INCREASING AS THE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A FAIRLY DEEP
AREA OF LOW PRESSURE TRACKING ACROSS HUDSON BAY. WINDS WILL RAMP
UP QUICKLY TO 30 KTS AND BECOME SOUTHWESTERLY ON NORTHERN LAKE
MICHIGAN LATE TONIGHT. A PERIOD OF SOUTHWEST GALES IS LIKELY
ACROSS THE NORTH HALF OF THE LAKE TUESDAY AND TUESDAY NIGHT WHEN
THE PRESSURE GRADIENT IS THE STRONGEST. THE GRADIENT WILL THEN
RELAX A BIT BY EARLY WEDNESDAY...AND WILL EVENTUALLY BACK TO THE
EAST THURSDAY NIGHT AS ANOTHER LOW LIFTS NORTHEAST FROM THE
SOUTHERN PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM MONDAY.
&&
$$
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
NWS CHICAGO/ROMEOVILLE IL
331 AM CST MON JAN 4 2016
.SHORT TERM...
327 AM CST
THROUGH TUESDAY...
THE LAKE EFFECT SNOW IN THE FORECAST AREA TODAY STILL LOOKS LIKE
A GOOD POSSIBILITY AND THE MAIN FORECAST CHANGE WAS TO REFINE AND
HONE IN ON THE TIMING AND IMPACTS. REGARDING TIMING...THROUGH A
COMBINATION OF OBSERVATIONAL TRENDS AND HIGH-RESOLUTION GUIDANCE
HAVE SPED UP THE START TIME OF THE SNOW SHOWERS IN FAR NORTHEAST
ILLINOIS AND FAR NORTHWEST INDIANA AND ALSO LIMITED THE SNOW
SHOWER DURATION FROM PREVIOUS FORECAST. THIS DID RESULT IN LESS
AVERAGE FORECAST SNOWFALL TOTALS...THOUGH AS ALWAYS WITH LAKE
EFFECT SNOW SHOWERS THERE CAN BE A HIGH AMOUNT OF VARIABILITY OVER
SPACE. AROUND AN INCH IS FORECAST IN LAKE ADJACENT COUNTIES WITH
THE LIKELY POSSIBILITY OF LESS IN SOME SPOTS AND A LITTLE MORE IN
OTHERS. A DUSTING IS FORECAST IN THE SECOND TIER COUNTIES
SURROUNDING THE SOUTHERN PART OF THE LAKE.
THE UPPER AIR PATTERN EARLY THIS MORNING CONTINUES TO BE ONE OF
REINFORCING COLD AIR ALOFT OVER THE GREAT LAKES...WITH A 130KT DUE
SOUTHWARD POINTING JET ENTERING THE REGION. THE 850MB TEMPERATURES
ARE AROUND -13C OFFERING AROUND AN ESTIMATED 15C DIFFERENCE
BETWEEN THE 850MB AND LAKE SURFACE TEMPERATURES. THIS HAS
RESULTED IN BROAD SNOW SHOWERS ORIENTED INTO LOWER MICHIGAN AND
MAINLY LA PORTE COUNTY INDIANA THUS FAR.
AT THE SURFACE...A COLD FRONT IS ORIENTED NORTHWEST-TO-SOUTHEAST
OVER THE CENTRAL PART OF THE LAKE AHEAD OF AN ARCTIC HIGH THAT
WILL MODIFY AS IT CREEPS SOUTHWARD TODAY. PRESSURE RISES OF
4-5MB/3HR ARE PUSHING THE FRONT SOUTHWARD WITH MORE PRONOUNCED DRY
AIR BEHIND IT. ALONG THE BOUNDARY A LAKE-INDUCED CIRCULATION IS
PRESENT ON RADAR MOSAIC AND WIND STREAMLINE ANALYSIS OFF THE SHORE
OF LUDINGTON MICHIGAN. THIS FEATURE SHOULD CONTINUE SOUTHWARD DOWN
THE LAKE WITH THE SYNOPTIC BOUNDARY EARLY THIS MORNING ASSISTING
IS LOCALIZED CONVERGENCE AND LIKELY BRIEFLY ENHANCING SNOWFALL
RATES ON THE WESTERN FLANK WHICH RIGHT NOW IS EXPECTED TO CLIP FAR
NORTHEAST ILLINOIS AND INTO NORTHWEST INDIANA. A MORE PRONOUNCED
BAND OR COUPLE BANDS ARE STARTING TO DEVELOP UPSTREAM WITH THIS
AND SHOULD CONTINUE TO BETTER DEVELOP GIVEN THE FORECAST
CONVERGENCE AND SUGGESTED SOLUTIONS BY CONVECTIVE ALLOWING
GUIDANCE. LAKE-INDUCED CAPE AT THE LEADING EDGE OF THIS LOOKS TO
BE 100-200 J/KG WITH AN EQUILIBRIUM LEVEL AROUND 8000 FT PER
MODIFIED RAP AND NAM SOUNDINGS. THIS WILL LIKELY SUPPORT A BURST
OF MODERATE TO BRIEFLY HEAVY SNOW SHOWERS FOR SOME LOCATIONS
WHERE THIS COMES INLAND...ARRIVING BETWEEN 9-11 AM CURRENTLY
LOOKS LIKE THE BEST FORECAST TIME. HOWEVER THIS BAND/S/ LOOKS TO
HAVE A SNAKE-LIKE SHAPE AND BE FAIRLY PROGRESSIVE...THUS LIMITING
RESIDENCE TIME IN ANY ONE LOCATION AS THE FRONT AND MESOLOW PUSH
SOUTHWARD. SO WHILE A QUICK INCH OR A LITTLE OVER MAY OCCUR FOR
SOME...AMOUNTS AFTER THAT FIRST HOUR OR SO LOOK TO BE LESS. IT
ALSO LOOKS LIKE THE SNOW SHOULD SQUEEZE IN JUST BEHIND THE MORNING
COMMUTE...HELPING TO MINIMIZE IMPACTS SOME. WILL STILL LIKELY
ISSUE AN SPS JUST FOR THE POTENTIAL FOR A RAPID CHANGE IN
VISIBILITY EVEN IF BRIEF.
GOING INTO THE EARLY-MID AFTERNOON BEHIND THE FRONT...LESS
ORGANIZED SNOW SHOWERS OR FLURRIES WILL REMAIN WITH LIGHT
ADDITIONAL ACCUMULATION AS EQUILIBRIUM HEIGHTS LOWER ON A
STRENGTHENING SUBSIDENCE INVERSION. THE EXCEPTION MAY BE LAKE
COUNTY ILLINOIS AND NORTHERN COOK WHERE SOME CONVERGENCE WITH A
LONG FETCH IS FORECAST...SO RESIDENCE TIME OF LIGHT SNOW COULD
HELP TO YIELD AN ADDITIONAL HALF INCH OR MORE...BUT EVEN THAT
LOOKS TO WEAKEN THROUGH THE AFTERNOON AS DRY ADVECTION
STRENGTHENS.
HIGHS TODAY ARE FORECAST TO PEAK IN THE UPPER 20S IN MOST
LOCATIONS WITH GRADUALLY MORE SUNSHINE FORECAST IN THE AFTERNOON
AWAY FROM LAKE INDUCED CLOUDS. TONIGHT SHOULD SEE THE SKY CLEAR
IN MOST IF NOT ALL LOCATIONS. HAVE GONE TOWARD COOLER GFS-BASED
MOS GUIDANCE WITH WINDS DROPPING OFF AND SOME LOCATIONS HAVING A
TAD BIT OF FRESH SNOW. SOME UPPER SINGLE DIGITS ARE PROBABLY A
DECENT BET IN FAVORED COOLER LOCATIONS.
MTF
&&
.LONG TERM...
327 AM CST
TUESDAY NIGHT THROUGH SUNDAY...
A SLOW MODERATION CONTINUES TO BE FORECAST MIDWEEK WITH A
DAMPENING UPPER RIDGE SHIFTING EAST OVER THE AREA AND SOUTHWEST
850-1000MB FLOW DEVELOPING UNDERNEATH. THE BLOCKED PATTERN IN THE
WESTERN CONUS IS FORECAST TO BREAK DOWN WITH A STRONG WEST-TO-EAST
PACIFIC JET EXPANDING INTO SOUTHERN CALIFORNIA. A LEADING SHORT
WAVE EJECTING FROM THIS IS EXPECTED TO MOISTEN THE LOW-LEVEL FLOW
INTO THE MISSISSIPPI VALLEY REGION AND THAT STILL IS FORECAST
DURING LATER WEDNESDAY NIGHT INTO THURSDAY. WOULD NOT BE
SURPRISED TO SEE THIS SLOW DOWN A TAD. TEMPERATURES...
THICKNESSES...AND FORECAST PROFILES IN GENERAL STILL LOOK
SUPPORTIVE OF POTENTIALLY LIGHT SNOW OR A WINTRY MIX AT THE
LEADING EDGE OF SATURATED ASCENT.
THE MORE PRONOUNCED LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP
OVER THE CENTRAL PLAINS THURSDAY NIGHT INTO FRIDAY YIELDING DEEPER
MOISTURE TRANSPORT AND MORE WIDESPREAD LIFT WITHIN UPPER
DIFFLUENCE...ALL SUPPORTING LIKELY RAIN AT THIS JUNCTURE. THE LIFT
AND ESPECIALLY MOISTURE IS PRESENTLY NOT FORECAST TO THE MAGNITUDE
OF SEVERAL OF THE HEAVY RAIN DECEMBER SYSTEMS WE SAW...SO QPF IS
PRESENTLY BELOW AN INCH...BUT STILL ONE HALF TO THREE-QUARTERS OF
AN INCH OF RAIN IN JANUARY ON SATURATED GROUND IS NOTEWORTHY AND
SOMETHING WE WILL HAVE TO WATCH. THE 04.00 GFS CONTINUES JUST A
TAD FURTHER EAST AS DOES ITS ENSEMBLE COMPARED TO THE EC. IT WOULD
REQUIRE A FAIRLY LARGE SHIFT TO GET THE STRONGER COLD ADVECTION
WITH THIS SYSTEM GIVEN ITS SOMEWHAT BROAD NATURE...SO STILL FEEL
GOOD NOT MENTIONING ANY WINTERY PRECIPITATION CHANCES THURSDAY
NIGHT THROUGH FRIDAY NIGHT. EVEN DURING THE WEEKEND...WINTRY
PRECIPITATION PRESENTLY LOOKS TO BE LIGHT IF IT WERE TO
MATERIALIZE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WINDS SHIFTING TO THE NORTHEAST LATE MORNING OR EARLY
AFTERNOON MONDAY WITH SPEEDS OF 10-12KT.
* LAKE EFFECT SNOW SHOWERS BEGINNING BY OR SHORTLY BEFORE NOON AND
PERSISTING INTO THE AFTERNOON. GENERALLY MVFR VIS LIKELY WITH
PERIODS OF VIS 1SM POSSIBLE. OCNL BRIEF PERIODS OF VIS LESS THAN
1SM POSSIBLE IN HEAVIER BANDS.
* MVFR CIGS LIKELY BY THE TIME OF SNOW ONSET AND CONTINUING INTO
EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 06Z...
SCT -SHSN HAVE PASSED THROUGH THE REGION THIS EVENING ASSOCIATED
WITH A MID LEVEL IMPULSE TRACKING ACROSS THE REGION. THERE IS A
CHANCE FOR BRIEF PERIODS OF VFR -SHSN UNTIL A COUPLE HOURS AFTER
MIDNIGHT...BUT CONDITIONS SHOULD REMAIN VFR.
OVERNIGHT...WINDS WILL GRADUALLY VEER FROM NWLY TO NELY AS HIGH
PRESSURE BUILDS ACROSS THE UPPER GREAT LAKES TO THE MIDDLE
MISSISSIPPI VALLEY. A WEAK PRESSURE GRADIENT OVER LAKE MICHIGAN
COMBINED WITH AN INFLUX OF COOLER AIR EXPECTED WHEN WINDS SHIFT
THROUGH NLY-NELY WILL SET UP A PATTERN CONDUCIVE TO LAKE EFFECT
SNOW. THE HIGH RESOLUTION MODEL GUIDANCE IS TRENDING TOWARD WHAT
THE LARGER SCALE MODELS HAD BEEN ADVERTISING...WITH A LAKE EFFECT
PLUME FORMING OVERNIGHT OVER THE ERN SIDE OF LAKE MICHIGAN AND
GRADUALLY MOVING TO THE WEST THROUGH THE EARLY MORNING HOURS. SNOW
SHOULD REACH GYY FIRST BY LATE MORNING AND THEN CONTINUE TO SHIFT
EAST...REACHING MDW/DPA/ORD BY LATE MORNING TO ARND NOON. THERE
IS SOME SUGGESTION THAT THE LAKE PLUME COULD BE IN A WEAKENING
PHASE AS THE PLUME REACHES THE CHICAGO AREA TERMINALS...BUT THE
LARGER SCALE SETUP SHOULD STILL BE CONDUCIVE TO BRING A PERIOD OF
LAKE EFFECT SNOW TO ORD/MDW. HAVE NOT MADE ANY SGFNT CHANGES TO
THE GOING FORECAST WITH RESPECT TO THE LAKE EFFECT SNOW AS EVEN
LIGHT SNOW CAN QUICKLY REDUCE VISIBILITY TO LOWER END MVFR OR IFR
LEVELS. WILL MAINTAIN THE PROB30 GROUP FOR 1SM AS ANY LAKE EFFECT
BAND THAT MANAGE TO REACH THE TERMINALS WOULD HAVE THE POTENTIAL
TO DROP VIS TO 1SM...OR POSSIBLY LESS...FOR AT LEAST BRIEF
PERIODS.
THE LARGE SCALE HIGH PRESSURE IS EXPECTED TO SAG ACROSS NERN
IL/SRN LAKE MICHIGAN/NRN INDIANA BY LATE AFTERNOON...SHUTTING OFF
THE LAKE EFFECT SNOW POTENTIAL AND SHIFTING WINDS TO SOUTHERLY.
MVFR CIGS SHOULD CONTINUE INTO THE EARLY EVENING...BUT AS THE HIGH
PRESSURE BUILDS ACROSS THE REGION...SKIES SHOULD QUICKLY SCATTER
OUT AND BECM MOSTLY CLEAR OVERNIGHT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN TIMING OF LAKE EFFECT SNOW MONDAY.
LOW CONFIDENCE IN TIMING AND DURATION OF VIS DROPPING TO 1SM OR
LESS IN HEAVIER BANDS OF SNOW.
* MEDIUM-HIGH CONFIDENCE IN WIND AND CEILING TRENDS THROUGH THE
PERIOD.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...VFR. SOUTH WINDS.
WEDNESDAY...VFR. SOUTH WINDS.
THURSDAY...CHC OF A WINTER MIX CHANGING TO RA DURING THE
DAY. MVFR CIGS LIKELY. SOUTH WINDS BCMG SOUTHEAST OVERNIGHT.
FRIDAY...-RA LIKELY. VFR BCMG MVFR PERHAPS IFR OVERNIGHT. EAST
WINDS.
SATURDAY...CHC -RA BCMG -SN OVERNIGHT. MVFR WITH IFR PSBL. WEST
WINDS.
KJB
&&
.MARINE...
237 PM CST
MAIN MARINE CONCERN IN THE NEAR TERM IS A PERIOD OF GUSTY 25-30
KT NORTH WINDS PRODUCING HAZARDOUS CONDITIONS FOR SMALL CRAFT
ALONG THE SOUTHERN LAKE MICHIGAN SHORE TONIGHT...AND ALONG BOTH
THE ILLINOIS AND INDIANA SHORES LATE TONIGHT AND MONDAY AS THE
WINDS BECOME MORE NORTHEAST. WINDS WILL DIMINISH FAIRLY QUICKLY
LATER MONDAY AS HIGH PRESSURE MOVES TOWARDS THE LAKE...PASSING
ACROSS IT MONDAY EVENING.
WINDS WILL TURN TO THE SOUTH LATE MONDAY NIGHT AS THE HIGH MOVES
OFF TO THE EAST... WITH THESE SOUTH WINDS INCREASING AS THE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A FAIRLY DEEP
AREA OF LOW PRESSURE TRACKING ACROSS HUDSON BAY. WINDS WILL RAMP
UP QUICKLY TO 30 KTS AND BECOME SOUTHWESTERLY ON NORTHERN LAKE
MICHIGAN LATE MONDAY NIGHT...WITH A PERIOD OF SOUTHWEST GALES
LIKELY THERE TUESDAY AND TUESDAY NIGHT. THE GRADIENT WILL THEN
RELAX A BIT BY EARLY WEDNESDAY...AND WILL EVENTUALLY BACK TO THE
EAST THURSDAY NIGHT AS ANOTHER LOW LIFTS NORTHEAST FROM THE
SOUTHERN PLAINS.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM MONDAY.
&&
$$
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...CORRECTED
NWS NORTHERN INDIANA
116 AM EST MON JAN 4 2016
.SYNOPSIS...
ISSUED AT 116 AM EST MON JAN 4 2016
LAKE EFFECT SNOW SHOWERS WILL CONTINUE OVERNIGHT AS THE COLDEST
AIR OF THE SEASON SETTLES INTO THE REGION. SNOWFALL COULD BE
LOCALLY HEAVY IN SOME LOCATIONS OVERNIGHT INTO EARLY MONDAY
MORNING...MAKING FOR A DIFFICULT MORNING COMMUTE IN THE LAKE
EFFECT COUNTIES. MORNING LOWS WILL GENERALLY BE IN THE 20 TO 25
DEGREE RANGE...WITH AFTERNOON TEMPERATURES ONLY A FEW DEGREES
HIGHER. LOWS BY TUESDAY MORNING WILL LIKELY BE IN THE SINGLE
DIGITS.
&&
.UPDATE...
ISSUED AT 820 PM EST SUN JAN 3 2016
THERE ARE NO IMMEDIATE PLANS FOR ANY HEADLINE CHANGES THIS
EVENING REGARDING THE ONGOING LAKE EFFECT SNOW ADVISORY. THE
INITIAL SYNOPTICALLY ENHANCED BAND DURING THE LATE AFTERNOON/EARLY
EVENING WAS SOMEWHAT TRANSITORY IN NATURE AS PASSING MID LEVEL
TROUGH INTERRUPTED OPPORTUNITY FOR MORE ORGANIZED BANDING. UP TO
THIS POINT...LACK OF DEEP MOISTURE THROUGH THE DGZ HAS LIMITED
EFFICIENCY OF SNOW ACCUMULATION WITH THIS BAND...WITH EVEN SOME
REPORTS OF SLEET/FREEZING RAIN AS THIS BAND PROGRESSED EASTWARD
EARLIER THIS AFTERNOON/EARLY EVENING WHICH LIMITED ACCUMULATIONS.
MORE PRONOUNCED LAKE THERMALLY ENHANCED TROUGHING RESIDES ACROSS
NORTHERN LOWER MICHIGAN SHORELINE AREA EARLY THIS EVENING AND WITH
ONLY SLOWLY RISING INVERSION HEIGHTS AND CONTINUED MARGINAL
RELATIVE HUMIDITIES IN CORE OF DGZ WOULD SUSPECT ONGOING LAKE
EFFECT SNOW SHOWERS FROM SOUTH HAVEN MI TO COLUMBIA CITY IN MAY
REMAIN OF RELATIVELY LOW INTENSITY FOR THE NEXT SEVERAL HOURS. BY
LATE TONIGHT...ESPECIALLY AFTER 05Z...SHOULD START TO SEE MORE
PRONOUNCED LAKE AGGREGATE TROUGHING BUILD SOUTHWARD INTO SOUTHWEST
LOWER MICHIGAN ALONG WITH MORE RAPIDLY INCREASING DEPTHS TO LAKE
INDUCED INSTABILITY. THIS SHOULD RESULT IN INCREASING INTENSITY OF
LAKE EFFECT BANDS IN THE 06Z-12Z TIMEFRAME. LATEST HRRR OUTPUT
STILL PAINTS HEAVIEST SNOW ACCUMULATIONS ACROSS EASTERN
BERRIEN/WESTERN CASS AND ACROSS THE FAR NORTHERN PORTIONS OF ST.
JOSEPH COUNTY INDIANA. GIVEN EVOLUTION OF ABOVE FACTORS...THIS
GENERAL AREA STILL SEEMS INLINE TO SEE THE HEAVIEST ACCUMULATIONS
ALTHOUGH UNCERTAINTIES STILL PERSIST REGARDING WHERE AXIS OF
STRONGEST LOW LEVEL CONVERGENCE WILL SET UP. 00Z RAOB FROM KGRB
DOES INDICATE A RATHER STRONG INVERSION BASED AROUND 775 MB WHICH
COULD BE ONE NEGATIVE FACTOR TO CONSIDER IN TERMS OF FULLY
REALIZING INSTABILITY MAGNITUDE OFFERED BY NAM FORECAST SOUNDINGS.
HIRES GUIDANCE STILL DEPICTS MESOVORTEX DEVELOPING ACROSS CENTRAL
LAKE MICHIGAN AS SFC TROUGH DROPS INTO THIS AREA...EVENTUALLY
DROPPING SOUTHWESTWARD INTO NORTHEAST ILLINOIS OR SOUTHEAST
WISCONSIN. IF THIS FEATURE DOES EVOLVE COULD SEE TEMPORARY
EASTWARD PUSH OF BETTER BANDING OVERNIGHT ACROSS EASTERN
CASS/ELKHART COUNTIES BEFORE FOCUS SHIFTS WESTWARD MONDAY MORNING.
THE POSSIBILITY OF A MORE TRANSITORY NATURE TO BANDING MONDAY
MORNING LENDS TO SOMEWHAT LOW CONFIDENCE IN ACCUMULATIONS ACROSS
LA PORTE COUNTY BUT WILL STICK WITH PREVIOUSLY FORECASTED 2 TO 4
INCH AMOUNTS GIVEN POTENTIALLY HIGHER SNOWFALL RATES WITH ANY
BANDING BY LATE TONIGHT/EARLY MONDAY MORNING.
GIVEN ABOVE UNCERTAINTIES WITH LAKE AGGREGATE...MESOVORTEX
EVOLUTION...AND INSTABILITY MAGNITUDE...WILL NOT MAKE ANY CHANGES
TO HEADLINES AT THIS TIME. MANY LOCATIONS NOT LIKELY TO EXPERIENCE
ADVISORY LEVEL AMOUNTS GIVEN ALL THE MESOSCALE FACTORS ABOVE...BUT
DIFFICULT AT THIS TIME TO DEVIATE MUCH FROM PREVIOUS THINKING
GIVEN POTENTIAL HIGHER SNOWFALL RATES OVERNIGHT. A NEW WSW WILL BE
SENT BY 0200Z.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 406 PM EST SUN JAN 3 2016
RAPIDLY EVOLVING SITUATION WITH REGARDS TO LAKE EFFECT EVENT
ACROSS THE GREAT LAKES THROUGH MONDAY MORNING. WILL DO THE BEST TO
SUM UP HIGHLIGHTS AND CONFIDENCE IN HOW THE EVENT MAY UNFOLD
ACROSS OUR AREA.
NEAR TERM...DOMINANT LAKE EFFECT BAND UNDERWAY EXTENDING FROM
WEST OF GRAND HAVEN MI CURVING SE INTO MUCH OF CASS COUNTY MI AND
POINTS SOUTH. HIGH CONFIDENCE ON ACCUMULATING SNOWFALL IN THIS
GENERAL AREA FOR THE NEXT COUPLE OF HOURS WITH A QUICK INCH OR 2
OF SNOW LIKELY. UPSTREAM TRENDS SHOW A DISRUPTION IN THIS BAND
WITH THE NEXT WAVE THAT SHOULD ALLOW IT TO WEAKEN...SHIFT EAST
INTO EARLY EVENING. IF THIS DOES NOT OCCUR...AMOUNTS ACROSS CASS
AND ELKHART COUNTY COULD BE MUCH HIGHER THAN CURRENTLY DEPICTED.
OUTSIDE OF THIS BAND..WIDELY SCT TO SCATTERED SNOW SHOWERS AND
FLURRIES ARE EXPECTED TO EXPAND ACROSS AT LEAST THE NW HALF OR SO
OF THE AREA.
TONIGHT...NEXT SURGE OF EVEN COLDER AIR WILL DROP INTO THE REGION
THIS EVENING...ALLOWING FOR A RAPID INCREASE IN LAKE EFFECT
PRODUCTION AS LAKE TO 850 MB TEMPERATURE DIFFERENCES INCREASE TO
NEARLY 20C. INVERSION HEIGHTS WILL ALSO SKYROCKET REACHING OR
EXCEEDING 10,000 FT ESPECIALLY IN THE 9 TO 15Z MONDAY WINDOW. DEEP
MOISTURE...PERFECT ALIGNMENT WITH DGZ AND SIGNS OF SUPERSATURATION
OF THE COLUMN IN AND ABOVE THE MOST FAVORABLE PRODUCTION ZONE ALL
POINT TOWARDS HIGH CONFIDENCE IN EXPANSION AND INTENSIFICATION OF
SNOW SHOWERS TONIGHT. CONFIDENCE DROPS TO MEDIUM WITH REGARDS TO
EXACTLY WHERE THE HEAVIEST SNOW BAND (S) WILL SET UP AND 2 TO 3
INCH PER HOUR SNOW RATES WILL HAVE THE GREATEST IMPACTS. FURTHER
COMPLICATING THE SITUATION WILL BE THE LIKELY DEVELOPMENT OF 1 OR
MORE MESOLOWS WITH THE STRONGEST OF THESE MOVING THROUGH IN THE 9
TO 15Z MONDAY WINDOW. HAVE TRENDED TOTAL SNOW AMOUNTS UPWARDS
ACROSS PORTIONS OF THE ADVISORY AREA...PUSHING NEAR WARNING
CRITERIA ACROSS EASTERN BERRIEN AND WESTERN CASS COUNTY MI.
CHANGES IN AMOUNTS AND POTENTIALLY HEADLINES MAY BE NEEDED THIS
EVENING INTO THE OVERNIGHT HOURS AS SETUP BECOMES CLEARER. FOR THE
REMAINDER OF THE FORECAST AREA...SCATTERED SNOW SHOWERS CAN BE
EXPECTED ESPECIALLY WITH CLOSER PROXIMITY TO THE LAKE. AMOUNTS
SHOULD GENERALLY BE LIGHT BUT STILL MAY CAUSE SOME SLIPPERY SPOTS
ON UNTREATED ROADS.
MONDAY...CHANGES MADE TO SLOW TIMING OF DOMINANT BANDS DEPARTURE
TO THE WEST WITH MUCH OF THE ADVISORY AREA LIKELY TO BE IMPACTED
DURING THE MORNING HOURS. TOTAL ACCUMULATIONS ACROSS THE ADVISORY
AREA WILL VARY GREATLY FROM 2 TO POTENTIALLY OVER 7 INCHES OF SNOW
DEPENDING ON THE FINAL EVOLUTION OF THE SNOW BANDS. BY
AFTERNOON...CLEARING WILL MOVE IN NE TO SW WITH A COLD DAY IN
STORE AS HIGHS STRUGGLE WARM BACK INTO THE 20S.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 406 PM EST SUN JAN 3 2016
ERN CONUS HGTS FLATTEN QUICKLY TO START THE PD IN WAKE OF LARGER
SCALE TROUGH PROGRESSING INTO THE WRN ATL AS SFC RIDGING EXPANDS
INVOF OF THE OH VALLEY. AFTER WHICH EPAC WAVE TRAIN EMBEDDED
WITHIN EL NINO SPLIT FLW ENTERS THE WRN US TUE W/LEAD SYS EMERGING
OVR THE SRN PLAINS WED AND THEN NEWD INTO THE LAKES LT THU. GIVEN
DECENT OVERALL CONSENSUS SOLUTION WRT TIMING OF ARRIVING SWRN US
SYS LT WEEK...BACK MENTIONABLE POPS TO THU NIGHT AND GENERALLY
BUMPED THEREAFTER AS UPR TROUGH ELONGATES ACRS THE LAKES.
SEASONABLY COLD TEMPS TO START MODERATE SIGLY TO WELL ABV NORMAL
LT PD AHD OF DEEPENING SWRLY FLW IN TANDEM W/EJECTING SWRN WAVE.
MUCH COLDER TEMPS LOOM THOUGH THROUGHOUT THE ERN US AS STEEP NOAM
PNA PATTN DVLPS AND POLAR VORTEX REFORMS ACRS SRN CANADA NXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 101 AM EST MON JAN 4 2016
SLIGHT MODIFICATIONS FOR KSBN TO HIGHLIGHT SLIGHTLY IMPROVED
DOMINANT CONDITIONS TEMPO IFR. AND WHILE LIFR REMAINS ENTIRELY
POSSIBLE BREVITY AND PRESENT UPSTREAM MORPHOLOGY OF DISJOINTED
SNOWBANDS SUGGEST LESSER DOOM/GLOOM. SLIGHT EARLIER END TIME TO
LAKE EFFECT AT KSBN AS DOMINATION OF LAKE AXIS LAND BREEZE OVER
MICHIGAN SWEEPS BAND WESTWARD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR INZ003>005.
MI...LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ077-078.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LMZ043-
046.
&&
$$
UPDATE...MARSILI
SYNOPSIS...MURPHY
SHORT TERM...FISHER
LONG TERM...T
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 DES MOINES IA
1147 PM CST SUN JAN 3 2016
.UPDATE...
ISSUED AT 927 PM CST SUN JAN 3 2016
HAVE HIT THE FOG WORDING A BIT HARDER OVER THE NW HALF OF THE
FORECAST AREA OVERNIGHT. LATEST RAP AND HRRR BOTH HAVE A GOOD
HANDLE ON CURRENT LOW VISIBILITIES THROUGH THE SIOUXLAND AREA AND
GRADUALLY EXPANDED THE FOG SOUTH AND EAST WITH TIME. NO HEADLINE
YET...BUT POSSIBILITY WILL CERTAINLY NEED TO BE MONITORED IF NW
OBS START DROPPING.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 320 PM CST SUN JAN 3 2016
BROAD AREA OF STRATUS STILL IN PLACE ACROSS IOWA THOUGH IT HAS BEEN
AGGRESSIVELY DISSIPATING OVER PORTIONS OF WEST CENTRAL MN THIS
AFTERNOON. HAVE KEPT MOSTLY CLOUDY CONDITIONS IN PLACE THROUGH
TONIGHT. WITH THE RESIDUAL MOISTURE IN PLACE...THE STRATUS SHOULD
START TO EXPAND BACK WEST SHORTLY AFTER MIDNIGHT OR MAY VERY WELL
FILL IN AS FOG AS HIGH PRESSURE BEGINS TO SETTLE OVER THE LOW LEVEL
MOISTURE. HAVE KEPT TEMPERATURES ABOVE GUIDANCE WITH THE EXPECTED
CLOUD COVER. HAVE ALSO BROUGHT FOG MENTION OVER WESTERN PORTIONS OF
THE FORECAST AREA. SHOULD CLEARING POCKETS DEVELOP...ADDITIONAL
AREAS OF FOG WILL BE POSSIBLE IN ADDITION TO LOCALIZED COLDER
TEMPERATURES.
.LONG TERM /MONDAY THROUGH SUNDAY/...
ISSUED AT 320 PM CST SUN JAN 3 2016
IN THE NEAR FUTURE THE STRATUS HAVE LITTLE PLACE TO GO. DESPITE
THE RIDGE MOVING OVER THE REGION BY MONDAY AFTERNOON THE STRATUS
LOOK TO EXPAND ENOUGH OVERNIGHT TONIGHT THAT IT WILL LIKELY TAKE
LONGER FOR THE CLOUDS TO DISSIPATE TOMORROW GIVEN THE TIME OF YEAR.
FOR NOW...WILL GO WITH PERSISTENCE AS EVEN THE MESOSCALE MODELS
ARE HOLDING ONTO SOME CLOUDS INTO MONDAY AFTERNOON. HIGHS MONDAY
WILL BE HELD BACK WITH THE CLOUD COVER...SIMILAR TO TODAY. THE
NEXT CHALLENGE WILL BE THE ARRIVAL OF THE WEAK SYSTEM ON WEDNESDAY.
A MINOR WAVE WILL APPROACH THE REGION WEDNESDAY WITH INCREASING
MOISTURE THROUGH H700. AS WARMER AIR ALSO LIFTS NORTH WITH THE
ACCOMPANYING SHORTWAVES LIFT...SOME LIGHT PRECIPITATION BEGINNING
AS SNOW WILL MOVE ACROSS THE REGION THROUGH MORNING THEN MIX IN
WITH SOME LIGHT RAIN OR LIGHT DRIZZLE LATER IN THE AFTERNOON.
DURING WED NIGHT THERE MAY BE A LIGHT MIX OF DRIZZLE OR FREEZING
DRIZZLE BUT FOR NOW HAVE NOT DEFINED THE THREAT IN GREAT DETAIL.
UNCERTAINTY OF THE THERMAL PROFILES FOR THIS EVENT IS MAKING PTYPE
FORECAST DIFFICULT. THIS TREND IS CONTINUING INTO THURSDAY AND
THURSDAY NIGHT WITH THE ARRIVAL OF THE MAIN SYSTEM...THOUGH THE
GENERAL TRENDS ARE FOR THE WARMER AIR TO OVERTAKE THE COLD AIR
ENOUGH TO CHANGE MUCH OF THE PRECIPITATION TO RAIN. BY LATE FRIDAY
AS THE SECOND SYSTEM BEGINS TO SHIFT EAST OF THE AREA...THE
PRECIPITATION WILL CHANGE BACK TO SNOW WITH SOME LIGHT ACCUMULATIONS
POSSIBLE AS THE LOW DEPARTS FRIDAY NIGHT INTO SATURDAY. HIGHS
THROUGH THE BULK OF THE WEEK WILL REMAIN MILDER THAN NORMAL ONCE
TUESDAY ROLLS AROUND. MOST AREAS WILL REACH THE 30S WITH THE
CENTRAL AND SOUTH THE UPPER 30S TO NEARING 40. LOWS WILL DROP INTO
THE 20S AND 30S. TOWARD THE END OF FRIDAY A THIRD SHORTWAVE WILL
TRACK ACROSS THE SOUTHERN US. CURRENTLY IT APPEARS THAT THE WAVE
WILL REMAIN FAR ENOUGH SOUTH THAT IT WILL NOT PHASE WITH THE
DIGGING NORTHERN STREAM. CURRENTLY THE EURO IS FARTHER WEST/NORTH
WITH THE TRACK OF THIS SYSTEM WHILE THE GFS REMAINS ALONG THE GULF
COAST. THOUGH IT LIKELY WONT BE A PROBLEM FOR OUR AREA...WILL
MONITOR FOR ANY POSSIBLE PHASING AND FARTHER NORTHWEST TRACK NEXT
WEEKEND. MEANWHILE...THERE CONTINUES A SIGNAL FOR MUCH COLDER
WEATHER BEYOND DAY7 AS AN ARCTIC INTRUSION BUILDS SOUTHEAST INTO
THE CENTRAL PLAINS. BY SUNDAY TEMPERATURES BEGIN TO SLIDE WITH
TEENS/20S FOR HIGHS AND LOWS IN THE SINGLE DIGITS DAY7 NIGHT.
&&
.AVIATION...04/06Z
ISSUED AT 1147 PM CST SUN JAN 3 2016
FOG AND CIG TRENDS REMAIN THE PRIMARY CONCERN THROUGH MON. LIFR-
MVFR CIGS ARE IN PLACE ACROSS THE FORECAST AREA NW-SE WITH THESE
LOWER VSBYS AND CIGS VERY GRADUALLY SPREADING SOUTH AND EAST
THROUGH THE EARLY MORNING HOURS. THERE IS FAIRLY HIGH CONFIDENCE
THAT LIFR CONDITIONS WILL REACH KFOD AND KMCW...AND IFR TOWARD
KDSM/KALO. OTHERWISE CONDFIDENCE WAS NOT THERE TO REDUCE FURTHER
AT THIS TIME...INCLUDING KEEPING KOTM MVFR FOR NOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...SMALL
SHORT TERM...DONAVON
LONG TERM...REV
AVIATION...SMALL
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1128 PM CST SUN JAN 3 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Monday)
Issued at 329 PM CST SUN JAN 3 2016
Tonight and Monday
Mid level ridging over the central CONUS continues to increase this
afternoon as broad troughing occurs from the Midwest towards the
Great Lakes region. Low stratus on the eastern edge of the high
pressure over Iowa into northern Missouri has slowly sank southward
through the day today. As the sun sets, temps currently in the
mid and upper 30s will quickly cool, carrying the stratus westward.
Forecast soundings develop a low stratus layer between 00 and 06Z at
the 950 mb layer. Some uncertainty exists between guidance on
timing of the stratus moving into the area, given the poor handling
of todays temperatures and lack of cloud cover. Forecast sided
closer to the RAP and HRRR solutions which have seemed to handled
trends through the afternoon. This result will also result in warmer
lows tonight in the upper teens and lower 20s given the mostly
cloudy skies. Patchy fog is also of concern, especially over north
central Kansas where cool temps and slower onset of cloud cover
could result in dense fog. Coverage and confidence is not high
enough for a headline at this time.
Sfc ridge progresses slowly eastward into northern Missouri Monday
shifting winds to the east and southeast below 10 mph. If widespread
stratus forms overnight, it will be difficult to mix out especially
over far east central Kansas where mixing remains very weak within
the boundary layer. Clearing is likely for most of the area by late
afternoon as better dry advection and mixing from the southeast will
help temps reach the low and middle 30s.
.LONG TERM...(Monday Night through Sunday)
Issued at 329 PM CST SUN JAN 3 2016
An upper ridge over the Central CONUS Monday
evening will move east Tuesday as a series of shortwave troughs move
into the plains from the desert southwest. The first shortwave
appears to be weakening as it moves through the central plains
Tuesday night and early Wednesday. The second, stronger wave,
should move through Thursday night and Friday. The northern stream
finally gets into the action late in the forecast period as
shortwave energy moves into the northern rockies and plains late in
the period. The models are in general agreement concerning these
large-scale features.
For northeast Kansas, we should have a few rounds of precipitation
associated with the passage of the upper troughs. The initial wave
will have limited moisture to work with Tuesday night and Wednesday.
Only brief focused forcing is expected and deeper moisture around
12Z Wednesday morning. While there is ice in the sounding, light
snow looks favored. However, in the absence of deep moisture and
forcing, soundings suggest a chance of freezing drizzle. Will have a
mixture of light freezing drizzle/light snow Tuesday night and early
Wednesday with small pops. Once the shortwave energy passes, low-
levels should remain nearly saturated over eastern Kansas with
sustained southerly flow in that layer. With only marginal UVV, will
keep a small chances of drizzle/light rain Wednesday into Wednesday
night.
The second round of precipitation Thursday and Friday should be more
significant, but based on temperature profiles at the time, it
should be all liquid precipitation over northeast Kansas. As the
system pulls out Friday night, what is left of the precipitation may
change over to light snow. However, by that point, the precipitation
chances are diminishing quickly.
Dry for the rest of the forecast next weekend with seasonally cold
temperatures. True arctic air should remain out of the area until
after the forecast period, but it may arrive next week.
As for temperatures, small diurnal ranges look likely with the
cloudiness and precipitation expected. Close to normal for highs,
but above normal lows.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1120 PM CST SUN JAN 3 2016
Good confidence that the KTOP/KFOE terminals start out under MVFR
CIGS while a period of IFR CIGS/VIS may be possible. Tried to
handle this with a TEMPO group at all TAF sites as IFR is a little
more low confidence as to how long it actually holds. KMHK a
similar situation as the stratus slowly moves in and should be
about 0730z at that site. Again, the IFR CIG/VIS only in a TEMPO
group as the concern for fog development will be lower due to
little snow still on the ground and persistent stratus deck not
allowing for as much radiational cooling that could otherwise have
taken place. Due to the high pressure in place, not expecting
significant mixing until late morning tomorrow to help break up
the stratus.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Johnson
AVIATION...Drake
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1105 PM CST SUN JAN 3 2016
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 1015 PM CST SUN JAN 3 2016
WV Imagery indicates a weak upper level ridge of high pressure
moving eastward across the Central Plains. Meanwhile, an upper
level trough of low pressure is pushing ashore into southern
California and Baja California. Near the surface, a broad area of
high pressure is drifting eastward across the Upper Midwest.
&&
.SHORT TERM...(THIS EVENING THROUGH Monday)
ISSUED AT 236 PM CST SUN JAN 3 2016
Winds will be fairly light for most of tonight, but should become
southeasterly by morning due to the aforementioned lee trough
development. Temperatures should easily fall into the upper teens
to lower 20s. The NAM and RAP hint at fog development, but
current thinking is that any fog would be confined to the
Interstate 70 corridor in central Kansas. Despite the south-
southeast winds on Monday, highs will probably only top out in the
upper 30s to lower 40s due to the light upslope wind component. A
few high clouds may move into western Kansas in the afternoon.
.LONG TERM...(Monday NIGHT THROUGH Sunday)
ISSUED AT 236 PM CST SUN JAN 3 2016
Weak lee troughing and southerly flow will allow for
some moisture return and milder overnight lows by mid-week.
Seasonable high temperatures can be expected through much of next
week in the absence of strong downslope flow or arctic air. There
are slight chances for rain Wednesday night into Thursday night
as upper level disturbances arrive from the southwest in the
presence of increasing low to mid level moisture and isentropic
lift. It is unclear whether it will be cold enough by Thursday
night for a changeover to snow across central and west central
Kansas. Most of the precipitation, albeit fairly light, should be
over by Friday. Colder air will move into western Kansas by
Saturday and Sunday as the leading edge of an arctic airmass
passes western Kansas.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Monday NIGHT)
ISSUED AT 1102 PM CST SUN JAN 3 2016
VFR conditions will prevail at all TAF sites overnight. However,
low level stratus developing across eastern Nebraska and northeast
Kansas is projected to edge westward into central Kansas toward
daybreak. As a result, IFR cigs/vsbys will be possible as far west
as KHYS early Monday morning. Otherwise, VFR conditions are expected
to persist through the day Monday at KGCK and KDDC.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 18 42 23 42 / 0 0 0 0
GCK 17 43 22 42 / 0 0 0 0
EHA 18 45 25 43 / 0 0 0 0
LBL 19 44 23 42 / 0 0 0 0
HYS 15 40 21 43 / 0 0 0 0
P28 18 40 21 40 / 0 0 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Finch
LONG TERM...Finch
AVIATION...JJohnson
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1017 PM CST SUN JAN 3 2016
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 1015 PM CST SUN JAN 3 2016
WV Imagery indicates a weak upper level ridge of high pressure
moving eastward across the Central Plains. Meanwhile, an upper
level trough of low pressure is pushing ashore into southern
California and Baja California. Near the surface, a broad area of
high pressure is drifting eastward across the Upper Midwest.
&&
.SHORT TERM...(THIS EVENING THROUGH Monday)
ISSUED AT 236 PM CST SUN JAN 3 2016
Winds will be fairly light for most of tonight, but should become
southeasterly by morning due to the aforementioned lee trough
development. Temperatures should easily fall into the upper teens
to lower 20s. The NAM and RAP hint at fog development, but
current thinking is that any fog would be confined to the
Interstate 70 corridor in central Kansas. Despite the south-
southeast winds on Monday, highs will probably only top out in the
upper 30s to lower 40s due to the light upslope wind component. A
few high clouds may move into western Kansas in the afternoon.
.LONG TERM...(Monday NIGHT THROUGH Sunday)
ISSUED AT 236 PM CST SUN JAN 3 2016
Weak lee troughing and southerly flow will allow for
some moisture return and milder overnight lows by mid-week.
Seasonable high temperatures can be expected through much of next
week in the absence of strong downslope flow or arctic air. There
are slight chances for rain Wednesday night into Thursday night
as upper level disturbances arrive from the southwest in the
presence of increasing low to mid level moisture and isentropic
lift. It is unclear whether it will be cold enough by Thursday
night for a changeover to snow across central and west central
Kansas. Most of the precipitation, albeit fairly light, should be
over by Friday. Colder air will move into western Kansas by
Saturday and Sunday as the leading edge of an arctic airmass
passes western Kansas.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Monday AFTERNOON)
ISSUED AT 1150 AM CST SUN JAN 3 2016
Surface high pressure will be situated across the central plains
through the period, resulting in light winds at the terminals.
VFR conditions will generally persist. However, the NAM and RAP
develop fog in central Kansas between 06 and 12z as weak upslope
flow develops after a night of radiational cooling. The NAM seems
to be too aggressive with the fog all the way south to KDDC. We
opted to keep the fog at KHYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 18 40 23 40 / 0 0 0 0
GCK 17 41 22 40 / 0 0 0 0
EHA 18 43 25 43 / 0 0 0 0
LBL 19 42 23 40 / 0 0 0 0
HYS 15 37 21 41 / 0 0 0 0
P28 18 40 21 40 / 0 0 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Finch
LONG TERM...Finch
AVIATION...Finch
AREA FORECAST DISCUSSION
NWS JACKSON KY
413 AM EST MON JAN 4 2016
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 412 AM EST MON JAN 4 2016
A FEW FLURRIES HAVE OCCURRED EARLIER HERE AT JKL...ALTHOUGH
NOTHING IS FALLING AT PRESENT. A FEW FLURRIES WERE REPORTED IN
EASTERN POWELL COUNTY AND IN BELL COUNTY OVERNIGHT. PER RECENT
RADAR RETURNS FLURRIES OR LIGHT SNOW SHOWERS ARE PROBABLY
OCCURRING IN THE BIG SANDY REGION AND NEAR INTERSTATE 64...BUT WE
HAVE NOT HAD ANY GROUND TRUTH REPORTS OF THAT FROM THAT AREA THUS
FAR. MORE SIGNIFICANT SNOW SHOWERS OR EVEN A FEW SNOW SQUALLS ARE
CURRENTLY UPSTREAM OVER SOUTHWESTERN OH AND EASTERN INDIANA AND
POISED TO DROP INTO EASTERN KY TODAY. UP TO A HALF OF AN INCH HAS
RECENTLY BEEN REPORTED FROM THE SNOW SHOWERS IN SOUTHWESTERN OH.
THE MAIN FORECAST CHALLENGE IN THE NEAR TERM IS THE SNOW SHOWERS
AND A FEW SNOW SQUALLS ANTICIPATED TODAY AS THE COLD FRONT AND AN
UPPER LEVEL DISTURBANCE WORK INTO AND ACROSS THE REGION AND THE
COMBINATION OF SOLAR INSOLATION AND COLDER AIR WORKING IN ALOFT
STEEPENS LAPSE RATES. THERE REMAINS MODEL UNCERTAINTY WITH THESE
AS THE NAM AND GFS HAVE EITHER ONE OR TWO LOCATIONS WHERE SNOW
SHOWERS SHOULD BE MOST PREVALENT AS DOES THE RECENT RAP RUNS. THE
0Z NAM AND THE 0Z GFS AS DOES THE 6Z NAM AS A MAX NEAR THE
INTERSTATE 75 CORRIDOR AND ANOTHER OVER THE NORTHERN TO EASTERN
PART OF THE CWA. THE RECENT RAP RUNS HAVE THE MAX GENERALLY FORM
ELLIOTT COUNTY TO MAGOFFIN COUNTY TO LETCHER COUNTY. WIDESPREAD
FLURRIES AND LIGHT SNOW SHOWERS ARE A CERTAINTY TODAY...WITH A FEW
LOCATIONS PICKING UP SNOW SQUALLS WITH GUSTS TO 20 MPH OR MORE AND
QUICK QUARTER OF AN INCH OR EVEN MULTIPLE SNOW SQUALLS. THE NNW
FLOW WOULD GENERALLY FAVOR THE HIGH TERRAIN OF SOUTHEASTERN KY IN
MOST INSTANCES FOR THE GREATEST ACCUMULATION AND OF COURSE
LOCATIONS THAT PICK UP MULTIPLE SNOW SQUALLS. MOST LOCATIONS WILL
PROBABLY NOT PICK UP MUCH MORE THAN A QUARTER OF AN INCH...ALTHOUGH
SOME OF THE HIGHER TERRAIN IN THE SOUTHEAST AND ANY LOCATIONS THAT
EXPERIENCE MULTIPLE SNOW SQUALLS MAY GET OVER A HALF OF AN INCH.
AN SPS WAS REFRESHED HIGHLIGHTING THIS. THE SNOW SHOWERS AND
SQUALLS SHOULD BE MOST PREVALENT DURING THE MORNING TO EARLY
AFTERNOON...AND THEN BEGIN TO WANE AS DRIER AIR FILTERS IN AT THE
LOW LEVELS. TEMPERATURES SHOULD ONLY HAVE A LIMITED RISE DURING
THE DAY TODAY.
SFC HIGH PRESSURE BUILDING IN BEHIND THE FRONT SHOULD SET THE
STAGE FOR CHILLY OVERNIGHT LOWS TONIGHT AND BELOW NORMAL
TEMPERATURES AGAIN ON TUESDAY. THERE REMAINS SOME UNCERTAINTY IN
HOW QUICKLY VALLEY LOCATIONS CAN DECOUPLE AND STRATOCU DISSIPATE...
BUT ADVECTION ALONE SHOULD BRING TEMPERATURES INTO THE TEENS IN
ALL AREAS. READINGS IN THE NORMALLY COLDER VALLEYS COULD BE A
COUPLE OF DEGREES BELOW THE CURRENT FORECAST IF DECOUPLING AND OR
CLEARING IS QUICKER. THESE WIDESPREAD READINGS IN THE TEEN SHOULD
BE THE COLDEST MOST LOCATIONS HAVE BEEN IN THE PAST 10 MONTHS OR
SO...SINCE MARCH 6 OR MARCH 7 OF 2015. TUESDAY SHOULD BE MOSTLY
SUNNY TO SUNNY WITH A FEW PASSING CIRRUS IN THE AFTERNOON...AND
FEATURE HIGHS IN THE 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM EST MON JAN 4 2016
THE EXTENDED PERIOD OF THE FORECAST WILL FEATURE A PERIOD OF DRY AND
WARMER THAN NORMAL WEATHER WEDNESDAY AND MOST OF THURSDAY. THE WARM
WEATHER WILL CONTINUE THROUGH THE UPCOMING WEEKEND...BUT A COUPLE OF
PASSING WEATHER SYSTEM WILL BRING CHANCES OF RAIN TO THE AREA FROM
THURSDAY EVENING ONWARD. THE BEST CHANCE OF RAIN WILL BE FROM
THURSDAY NIGHT THROUGH FRIDAY...AS WELL DEVELOPED AREA OF LOW
PRESSURE MOVES ACROSS THE MID MISSISSIPPI VALLEY AND INTO THE GREAT
LAKES THURSDAY NIGHT AND FRIDAY. THE MODELS WERE IN PRETTY GOOD
AGREEMENT WITH THIS FIRST WEATHER SYSTEM...SO LIKELY POPS SEEMED
REASONABLE FOR THE THURSDAY NIGHT FRIDAY TIME FRAME...WITH A GRADUAL
DECREASE IN RAIN CHANCES FRIDAY NIGHT AND SATURDAY. DECIDED TO KEEP
THE RAIN CHANCES IN PLAY FOR SATURDAY AND SATURDAY NIGHT TO ACCOUNT
FOR THE PRESENCE OF WHAT APPEARS TO BE A WEAK SURFACE BOUNDARY THAT
THE ECMWF MODEL IS KEEPING IN PLACE ACROSS CENTRAL KENTUCKY AND
WESTERN TENNESSEE. A SECOND DISTURBANCE IS FORECAST TO PASS THROUGH
THE REGION SUNDAY AND SUNDAY NIGHT...BUT THE MODELS ARE IN POOR
AGREEMENT AS TO THE EXACT TRACK OF THIS SYSTEM. THE GFS HAS THE
WEEKEND LOW PRESSURE MOVING BY FAR ENOUGH TO OUR SOUTH AND SOUTHEAST
TO KEEP THE AREA MOSTLY DRY...WHILE THE ECMWF MODEL TAKES THE SAME
LOW ACROSS CENTRAL KENTUCKY AND INTO THE OHIO VALLEY. THE ECMWF
SCENARIO WOULD BRING ANOTHER GOOD CHANCE OF RAIN TO THE AREA...WHILE
THE GFS WOULD GIVE US LITTLE IF ANY PRECIPITATION. THAT BEING
SAID...DECIDED TO SIDE MORE WITH THE ECMWF MODEL FOR THE END OF THE
PERIOD AND GOING WITH SMALL RAIN CHANCES TO FINISH OUT THE WEEKEND.
TEMPERATURES LATE SUNDAY NIGHT MAY GET CLOSE ENOUGH TO FREEZING TO
ALLOW A FEW FLAKES OF SNOW TO MIX IN WITH ANY RAIN THAT FALLS.
DAY TIME HIGHS DURING THE PERIOD ARE EXPECTED TO TOP OUT IN THE 50S
THURSDAY THROUGH SATURDAY...AND IN THE 40S ON WEDNESDAY AND SUNDAY.
OVERNIGHT LOWS WILL VARY GREATLY DUE TO THE PASSAGE OF THE TWO
AFOREMENTIONED WEATHER SYSTEMS. THE COLDEST AIR OF THE WINTER SEASON
IS EXPECTED TO SETTLE OVER THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING...AS A POLAR AIR MASS SETTLES OVER THE OHIO AND TENNESSEE
VALLEY REGIONS. MINIMUM TEMPERATURES ON WEDNESDAY MORNING ARE
EXPECTED TO DROP INTO THE TEENS AREA WIDE...WITH OUR VALLEY
LOCATIONS PERHAPS SEEING THE LOW TO MID TEENS. WEDNESDAY NIGHT WILL
SEE A SLIGHT WARM UP AS THE AIR MASS MODIFIES A BIT BENEATH MOSTLY
SUNNY SKIES DURING THE DAY. LOWS WEDNESDAY NIGHT ARE FORECAST TO
ONLY FALL INTO THE UPPER 20S. WE SHOULD SEE LOWS GENERALLY IN THE
LOWER 40S THURSDAY NIGHT THROUGH SATURDAY NIGHT AS WINDS SHIFT
AROUND TO THE SOUTH AND CLOUD COVER OVERSPREADS THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 135 AM EST MON JAN 4 2016
AVIATION POINTS ARE STARTING THE PERIOD VFR TO MVFR AS A STRATUS
AND STRATOCU HAS MOVED INTO THE AREA. AN APPROACHING UPPER LEVEL
TROUGH AND COLD FRONT WILL BRING A FEW FLURRIES 6Z TO 12Z...A
CHANCE OF SNOW SHOWERS AND SQUALLS MAINLY 11Z TO 19Z. THERE IS
STILL SOME UNCERTAINTY AND LOCATION OF THE HEAVIER SNOW SHOWERS
AND THUS HAVE LIMITED TO A FEW HOUR BLOCK OF MVFR VIS 11Z TO 16Z
TO 18Z WITH A FEW MORE HOURS OF JUST REDUCTIONS TO MVFR CIGS.
THESE SNOW SHOWERS WILL PRODUCE TIMES OF SUDDEN REDUCTIONS IN VIS
POSSIBLY TO IFR OR AIRPORT MINS IF A LOCATION TAKES A DIRECT HIT
FROM A HEAVIER SNOW SHOWERS. OTHERWISE...BY THE 20Z TO 0Z PERIOD
MOST LOCATIONS SHOULD RETURN TO VFR. GUSTY CONDITIONS WILL BE
POSSIBLE WITH ANY SNOW SQUALLS THAT DEVELOP ON MONDAY...OTHERWISE
MOST SITES WILL SEE WINDS FROM THE NORTHWEST TO NORTH AT KT OR
LESS THROUGH THE PERIOD...WITH WINDS SLACKENING 0Z TO 6Z
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JP
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1153 PM CST SUN JAN 3 2016
.UPDATE...
ISSUED AT 1002 PM CST SUN JAN 3 2016
ISSUED A DENSE FOG ADVISORY UNTIL 9 AM MONDAY MORNING FOR MUCH OF
WEST CENTRAL THROUGH SOUTH CENTRAL MN. VISIBILITIES CONTINUE TO
LOWER LATE THIS EVENING TO A QUARTER MILE OR LESS ACROSS WEST
CENTRAL MN UNDER THE RIDGE OF HIGH PRESSURE MOVING IN FROM SD.
THE THINKING OVERNIGHT IS THAT THE DENSE FOG WILL EXPAND INTO
SOUTH CENTRAL MN PER HRRR FORECASTS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CST SUN JAN 3 2016
THE SHORT TERM FORECAST CONCERNS ARE CLOUD COVER...HOW FAR SOUTH
AND EAST THE CLEARING LOCATED IN NW MN WILL EXTEND AS WELL AS
OVERNIGHT TEMPERATURES ASSOCIATED WITH CLOUDS OR NO CLOUDS.
SATELLITE SHOWS CLEAR SKIES OVER NW MN AND ALL OF ND AND MOST OF SD.
THIS AREA OF CLEARING IS SLOWLY MOVING SOUTHEAST AND IT IS
QUESTIONABLE AS TO HOW FAR SOUTH AND EAST IT WILL GO. MODEL
SOLUTIONS ARE SOMEWHAT MIXED. THE HRRR WANTS TO MIX OUT CLOUDS IN A
SOMEWHAT NATURAL PROGRESSION FROM NW TO SE. THE VARIOUS HOPWRF RUNS
ARE SOMEWHAT CONFLICTING TOO. IF YOU USE H875 OR H900 RH AS A PROXY
FOR WHERE CLOUDS ARE AND ARE NOT...THE GFS SHUNTS RH EAST OF THE
AREA AROUND 06Z. THE NAM IS EVEN FASTER. THE CHALLENGE IS WITH HIGH
PRESSURE WEST OF THE AREA AND DRIFTING SE TOWARD SW MN THERE IS NO
COMPELLING ARGUMENT FOR UNLOADING ENOUGH OF THE LOW LEVEL MOISTURE
TO SCATTER THE CLOUDS OUT. TO MAKE THINGS MORE CHALLENGING AREA THAT
WERE DOMINATED BY THE HIGH PRESSURE TODAY SAW VIRTUALLY NO LOSS OF
CLOUD COVER. AS A RESULT WILL SLOWLY SCATTER THE CLOUDS BETWEEN THE
I-94 CORRIDOR AND THE MN RIVER VALLEY TONIGHT. THERE MAY BE SOME
BREAK IN THE CLOUDS AS FAR SOUTH AND EAST AS THE TWIN
CITIES. SO WILL CONTINUE THAT TREND INTO MONDAY. WESTERN WI WILL
REMAIN OVERCAST. OVERNIGHT LOWS WERE ADJUSTED TO ACCOUNT FOR THE
VARYING CLOUD COVER. MORE SCATTERING OF CLOUDS IS EXPECT ON MONDAY
AS THE HIGH MOVES SOUTHEAST AND WINDS BECOME MORE SOUTHEASTERLY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CST SUN JAN 3 2016
SEVERAL CONCERNS OVER THE NEXT 7 DAYS IN TERMS OF PRECIPITATION
TYPE/SNOWFALL RATIOS AND SFC TEMPS WHICH WILL LEAD TO
UNCERTAINTIES OF SNOWFALL AMTS.
TUESDAY/TUESDAY NIGHT WILL BE DRY...BUT WINDS WILL SHIFT TO THE
SOUTH AND COMMENCE THE MUCH MILDER CONDS FOR WED/THU/FRI BEFORE
PROBABLY THE COLDEST AIR OF THE SEASON MOVES IN NEXT WEEKEND.
FIRST...THE SYSTEM MOVING INTO SOUTHERN CALIFORNIA OVER THE NEXT
12-24 HRS WILL BE THE FIRST INGREDIENT FOR PRECIPITATION TO
DEVELOP LATE WEDNESDAY AFTN/EVENING AS ENERGY FROM THIS SYSTEM
MOVES NE ACROSS THE UPPER MIDWEST. THIS SYSTEM WILL BE RELATIVELY
MOISTURE STARVED INITIALLY...BUT WITH THE INCREASING SOUTHERLY
FLOW AHEAD AND BEHIND IT...QPF AMTS WILL LIKELY INCREASE IN FUTURE
MODEL RUNS. ALSO THIS WILL SET THE STAGE FOR LATE IN THE WEEK AS
ANOTHER SYSTEM MOVES IN...WITH PRECIPITABLE WATER VALUES
INCREASING TO OVER 0.50". ALTHOUGH WEDNESDAY SYSTEM WILL BE COLD
ENOUGH INITIALLY FOR ALL SNOW...AM CONCERN AT THE END AS WET-BULB
TEMPS IN THE FIRST 0-1KM INCREASES TO AROUND +0.5C ALONG THE MN/IA
BORDER. AT LEAST ONCE SNOW DEVELOPS AND SFC TEMPS RISE TO NEAR
FREEZING OR SLIGHTLY ABV...SNOWFALL WILL LIKELY BE LIMITED WITH
SNOWFALL RATIOS DROPPING TO AROUND 8-1 OR 5-1. THIS LEADS TO
SNOWFALL AMOUNTS OF LESS THAN ONE INCH FOR MOST AREAS THAT STAY
ALL SNOW. OUR SNOWFALL PROBABILITIES HAVE A BETTER CHANCE OF 1-2"
OUTSIDE OUR GREATEST QPF AREAS WEST/NW OF THE TWIN CITIES METRO
AREA. SEE THE LATEST TRENDS ON OUR WEB PAGE.
WWW.WEATHER.GOV/MPX/WINTER.
ONCE WEDNESDAY SYSTEM MOVES OFF...THERE SHOULD BE A BREAK IN THE
PRECIPITATION UNTIL LATE THURSDAY NIGHT/FRIDAY DEPENDING UPON THE
SPEED OF THE NEXT SHORTWAVE MOVING OUT OF THE DESERT SW LATE IN
THE WEEK. MOST MODELS HAVE THE BEST TIME FRAME OF PRECIPITATION
DEVELOPING FRIDAY AFTERNOON/EVENING...AND SLOWLY EXITING THE AREA
SATURDAY. HAVE INCREASED POPS TO LIKELY FOR PORTIONS OF MPX CWA
FRIDAY/FRIDAY NIGHT...BUT STILL SOME UNCERTAINTIES ON LOCATION OF
THE BEST LIFT AND SFC FEATURES. BASED ON THE LATEST MODEL
RUNS...IT IS LIKELY THAT THIS SYSTEM WILL BE WARM ENOUGH FOR A
PERIOD OF RAIN OR RAIN/SNOW MIX IN MPX SE CWA. OR BASICALLY FROM
SC TO EC MN AND INTO WC WI. DEPENDING UPON THE UPPER LEVEL
FEATURES...THE WARMER AIR COULD ACTUALLY MOVE FURTHER TO THE NW
ALLOWING FOR MOST OF THE AREA TO SEE RAIN/SNOW BEFORE COLDER AIR
ARRIVES SATURDAY. AGAIN...THIS IS BASED ON THE CURRENT MODEL RUNS
WHICH IS TOO FAR OUT TO GUARANTEE ANY EXACT QPF AND SNOWFALL AMTS.
EVEN IF THE SYSTEM IS COLD ENOUGH FOR ALL SNOW...SNOWFALL RATIOS
WILL LIKELY BE NEAR 10-1 OR LOWER AROUND 6 OR 8-1.
THEREFORE...KEEPING SNOWFALL AMOUNTS ON THE LOW SIDE. SFC TEMPS
WILL REFLECT THE MILDER AIR WITH READINGS HOLDING NEAR FREEZING OR
SLIGHTLY ABOVE ONCE THE PRECIPITATION DEVELOPS.
DUE TO THE FACT THE MODELS HAVE TRENDED TOWARD A LARGE AREA OF
COLD AIR FROM NORTHEAST CANADA TO MOVE SOUTHWARD NEXT
WEEKEND...THE PROBABILITY OF THE COLDEST AIR OF THE SEASON WILL
ARRIVE LATE NEXT WEEKEND AND INTO EARLY NEXT WEEK. OUR FIRST BELOW
ZERO READING /MPX CWA WIDE/ IS ALSO LIKELY DURING THIS TIME
FRAME. IN ADDITION...THE EPO /EASTERN PACIFIC OSCILLATION/ WHICH
IS CURRENTLY NEGATIVE AND WILL REMAIN NEGATIVE THROUGH THE 13TH OF
JANUARY...LEADS TO MUCH COLDER AIR PROBABILITIES ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST. THIS IS THE SAME SCENARIO WITH WPC
BELOW NORMAL TEMPS FOR THE 6-14 DAY TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1152 PM CST SUN JAN 3 2016
THERE ARE 2 MAIN AREAS OF INTEREST WE ARE CURRENTLY WATCHING...THE
FIRST BEING AN AREA OF DENSE FOG CURRENTLY ACROSS PARTS OF WESTERN
AND SOUTHERN MN...AND THE SECOND IS AN AREA OF LOW CLOUDS MOVING
SOUTHWARD THROUGH NE MN AND NW WI. THE AREA OF FOG...CURRENTLY
IMPACTING RWF WITH 1/2 MILE VIS AND 200 FT CIGS...COULD SPREAD TO AXN
AND STC BY EARLY MORNING...BUT SOME UNCERTAINTY REMAINS. FARTHER
EAST...THE AFOREMENTIONED AREA OF LOW CLOUDS WILL CONTINUE MOVING
SOUTHWARD...AND WILL LIKELY IMPACT RNH WITH MVFR CIGS SHORTLY.
THESE LOW CLOUDS COULD IMPACT MSP AND EAU AS WELL...BUT CONFIDENCE
IS LOWER IN MVFR CIGS REACHING THESE SITES.
VFR CONDITIONS SHOULD RETURN TO CENTRAL AND WESTERN MN TOMORROW
LATE MORNING AS ANY REMAINING FOG IS EXPECTED TO DISSIPATE.
HOWEVER...IN EASTERN MN AND WESTERN WI...THE MVFR CIGS COULD
PERSIST IN SOME AREAS THROUGHOUT THE DAY ON MONDAY. WINDS WILL BE
LIGHT AND VARIABLE ON MONDAY MORNING...BECOMING SOUTHERLY BUT
REMAINING LIGHT THROUGH THE REST OF THE DAY.
KMSP...VFR CIGS ARE EXPECTED FOR THE NEXT FEW HOURS...BUT SOME
PATCHY FOG CANNOT BE RULED OUT FROM AROUND 09Z THROUGH SUNRISE.
ALSO...AN AREA OF LOW CLOUDS CURRENTLY MOVING SOUTH THROUGH
NORTHEAST MN MAY IMPACT THE TERMINAL ON MONDAY MORNING...AND COULD
CONTINUE OFF AND ON THROUGH THE AFTERNOON AND EVENING. IF THESE
CLOUDS REACH MSP...THEY WOULD LIKELY HAVE MVFR CIGS. WINDS WILL
LIKELY REMAIN BETWEEN 5-8 KTS FOR MOST OF THE PERIOD...STARTING
OUT NORTHWESTERLY OVERNIGHT AND BECOMING SOUTH-SOUTHEASTERLY ON
MONDAY.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS S 10-17 KTS.
WED...MVFR CIGS LIKELY. CHANCE -SN. WINDS 5-10 KTS.
THU...MVFR CIGS LIKELY. SLIGHT CHANCE -SN. WINDS SE 5-8 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...DENSE FOG ADVISORY UNTIL 9 AM CST MONDAY FOR MNZ047-048-054>057-
064-065-073>075-082-083-091-092.
&&
$$
UPDATE...RAH
SHORT TERM...DRL
LONG TERM...JLT
AVIATION...ADL
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 AM CST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CST MON JAN 4 2016
SATELLITE AND OBSERVATIONS SHOW STRATUS AND FOG ACROSS EASTERN
NEBRASKA AND KANSAS THAT IS MOVING TO THE WEST TONIGHT. AHEAD OF THE
STRATUS VISIBILITIES HAVE BEEN DROPPING AND A FEW LOCATIONS HAVE
DROPPED BELOW A HALF MILE. LOOKING AT WEBCAMS AROUND THE AREA THE
VISIBILITY APPEARS TO VARY GREATLY FROM LOCATION TO LOCATION.
AS THE STRATUS MOVES TO THE WEST EXPECT THE FOG ON THE EDGE OF THE
STRATUS TO ALSO MOVE TO THE WEST. THE HRRR HAS SOME FOG SPREADING
INTO THE FORECAST AREA...BUT THE FOG IS SPREADING A LITTLE FASTER
THAN THE LATEST RUN. BASED ON THE LOCATION OF THE LOWER VISIBILITY
FROM THE HRRR THE WORST OF THE FOG SHOULD BE IN THE EASTERN HALF TO
TWO THIRDS...MAINLY ALONG AND EAST OF HIGHWAY 183. HAVE KEPT SOME
FOG IN THE WEST...BUT HAVE THE WORSE CONDITIONS FURTHER TO THE EAST.
SO THE NEXT QUESTION BECOMES WHEN WILL THE VISIBILITY IMPROVE? THE
HRRR KEEPS VISIBILITY LOWER THROUGH THE MORNING HOURS AND EAST OF
HIGHWAY 281 AND NORTH OF HIGHWAY 6 COULD LINGER THROUGH MUCH OF THE
DAYTIME HOURS. HAVE KEPT SOME FOG THROUGH THE MORNING HOURS THEN
MOSTLY CLOUDY SKIES THROUGH THE AFTERNOON.
THE SURFACE HIGH CENTERED OVER WESTERN IOWA EARLY THIS MORNING IS
EXPECTED TO MOVE TO THE EAST. THE PRESSURE GRADIENT WILL TIGHTEN FOR
TODAY AND TONIGHT. THROUGH THE DAYTIME THE WINDS ALOFT ARE ONLY 10
TO 20 KTS SO NOT EXPECTING WINDS TO INCREASE MUCH...BUT THEY SHOULD
TURN TO THE SOUTH INSTEAD OF FROM THE EAST AS THEY ARE EARLY THIS
MORNING. THIS SHOULD HELP THE FOG BECOME LESS OF A CONCERN FOR LATER
THIS MORNING AND INTO THE AFTERNOON.
THE PRESSURE GRADIENT CONTINUES TO BE FAIRLY TIGHT TONIGHT AND WINDS
ALOFT INCREASE TO AROUND 45KTS. WINDS WILL NOT BE STRONG
TONIGHT...BUT THEY WILL INCREASE TO THE 10 TO 20 MPH RANGE AND FOG
SHOULD NOT FORM TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 359 AM CST MON JAN 4 2016
LONG TERM COMING SOON.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1118 PM CST SUN JAN 3 2016
LOW CLOUDS AND FOG/MIST WILL BE THE MAIN CONCERN FOR THE FORECAST
PERIOD. STRATUS IS MOVING TOWARD THE WEST AND WILL APPROACH THE
TERMINALS IN THE NEXT FEW HOURS. THERE WILL BE SOME FOG/MIST THAT
SHOULD REDUCE VISIBILITIES. THE NEXT CONCERN WILL BE HOW LONG IT
WILL HOLD ON IN THE MORNING. HAVE KEPT IT DURING THE MORNING BUT
CLEARED THINGS OUT IN THE AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
342 AM CST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CST MON JAN 4 2016
TODAY AND TONIGHT...THE ARCTIC DRAPE ACROSS ERN NEB SHOULD BE PULLED
WEST INTO THE FCST AREA THIS MORNING AND THEN NORTH DURING THE AFTN.
THE RAP MODEL BOUNDARY LAYER RH PROVIDES A PESSIMISTIC FCST OF
STRATUS APPROACHING HIGHWAY 83 AND SOCKING AREAS EAST ALL DAY. THE
NAM IS MORE MODERATE SUGGESTING MIXING AND SUNSHINE TODAY TO BE
REPLACED BY HIGH CLOUDS IN THE AFTN. THIS APPEARS TO BE SUPPORTED BY
THE GFS AND ECM.
AREAS OF FOG ARE UNDERWAY AS INDICATED IN THE RAP WHICH WOULD MIX
OUT THIS AFTN AS SHOWN BY THE NAM. THE TEMPERATURE FORECAST USES THE
ECS AND MAV GUIDANCE PLUS BIAS CORRECTION FOR HIGHS IN THE 30S TO
AROUND 40. SOUTH WINDS INCREASE TO 10 TO 20 MPH. H850MB TEMPERATURES
RISE TO 2 TO 6C THIS AFTN WHICH COULD PRODUCE HIGHS IN THE 40S
ACROSS ALL AREAS. THE TEMPERATURE FORECAST REPRESENTS A DIFFERENTIAL
BETWEEN THE SOUTH WINDS AND HIGH CLOUDS WHICH LIMIT MIXING VS WARM
AIR ADVECTION.
TONIGHT THE GFS AND NAM INDICATE STRATUS DEVELOPMENT IN A GRADIENT
OF STRONG SOUTHWEST WINDS. THE ECM BUILDS A MESO HIGH ACROSS THE
SANDHILLS ELIMINATING MOISTURE POOLING FOR CLOUD FORMATION. THE
FORECAST FOLLOWS THE GFS AND NAM WITH LOWS IN THE TEENS AND LOWER
20S. SOUTH WINDS CONTINUE AT 10 TO 20 MPH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 342 AM CST MON JAN 4 2016
12Z TUESDAY AND BEYOND. THE MODELS CONTINUE TO ADVERTISE THE
PASSAGE OF A LEAD SHORTWAVE FROM THE SOUTHWEST LATE TUESDAY INTO
WEDNESDAY. THE MODELS SUGGEST INCREASING SYSTEM RELATIVE UPGLIDE
GENERALLY ALONG THE 285-290K SURFACES THAT MAY WORK IN CONJUNCTION
WITH SMALL CONDENSATION PRESSURE DEFICITS TO PRODUCE LIGHT QPF
ACROSS OUR EASTERN ZONES EARLY WEDNESDAY. THE GFS IS LEADING THE
CHARGE WITH SUFFICIENT SATURATION TO PRODUCE A FEW HUNDRETHS
QPF...WHEREAS THE NAM AND THE ECMWF CONFINE MOISTURE IN THE LOWEST
LAYERS OF THE TROPOSPHERE AND GENERALLY FAVOR STRATUS...OR POSSIBLY
LIGHT DZ. WILL MAINTAIN A DRY FORECAST FOR NOW...BUT CONTINUE TO
CLOSELY MONITOR AS THE TIMING OF THE EVENT WOULD FAVOR FROZEN
QPF...EITHER -FZDZ OR -SN. THE SYSTEM AND ANY POTENTIAL QPF IS
SHOWN TO BE EAST OF THE FORECAST AREA BY 00Z THURSDAY. THE WAVE IF
NOTHING ELSE WILL PULL A WEAK BOUNDARY SOUTH ACROSS THE SANDHILLS ON
WEDNESDAY...COOLING TEMPERATURES SLIGHTLY.
ATTENTION TURNS TO THE NEXT PIECE OF ENERGY EJECTING FROM A WESTERN
CONUS MID-LEVEL TROUGH. THE GENERAL IDEA OF THE ECMWF AND GFS IS TO
DEVELOP A CLOSED LOW SOUTH OF THE CWA LATE THURSDAY INTO FRIDAY.
HOWEVER...THE MODELS /ESPECIALLY THE GFS/ HAVE TRENDED SOUTH WITH
THIS FEATURE. CONFIDENCE IS WANING...THUS NO CHANGES WERE MADE TO
THE EXTENDED BLEND PROCEDURE...WHICH ESSENTIALLY PRODUCED SIMILAR
RESULTS FROM THE PREVIOUS FORECAST. THE HIGHER END CHANCE POPS ARE
MAXIMIZED ACROSS OUR SOUTHERN AND EASTERN ZONES...WHICH IS
APPROPRIATE. PTYPE IS UNCERTAIN AT THIS POINT AS THE VARIOUS MODELS
SUGGEST DIFFERING AMOUNT OF SATURATION AND THERMAL PROFILES. LIGHT
FZDZ...-RA...-SN OR -ZR CANNOT BE RULED OUT AT THIS POINT. GIVEN THE
RECENT PATTERN...THE MOST LIKELY PTYPE WILL BE -SN WITH POSSIBLY A
PERIOD OF -FZDZ. MORE CERTAIN IS THAT IN THE WAKE OF THE SYSTEM
COLDER AIR WILL BE DRAWN SOUTH ACROSS THE CENTRAL PLAINS FOR LATE
WEEK AND THE WEEKEND. AS THE ARCTIC HIGH SETS UP RESIDENCE ACROSS
WEST CENTRAL NEBRASKA ON SUNDAY...HIGHS MAY STRUGGLE TO CLIMB OUT OF
THE TEENS WITH AREAS OF SUB 0F LOWS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1145 PM CST SUN JAN 3 2016
FOG IS EXPECTED TO DEVELOP MAINLY EAST OF A KANW TO KBBW LINE
OVERNIGHT. FOR LOCATIONS WEST OF THIS LINE...THE THREAT FOR FOG
DEVELOPMENT BASED ON THE LATEST MODEL SOLUTIONS IS MINIMAL
ATTM...WITH NO THREAT EXPECTED FOR KVTN. DECIDED TO RUN A TEMPO
GROUP FOR FOG FOR THE KLBF TERMINAL FROM 11Z TO 15Z MONDAY WITH
VISBYS AS LOW AS 5SM EXPECTED. THERE IS AN ADDITIONAL THREAT FOR
LOW CLOUD DEVELOPMENT OVER SOUTHWESTERN NEBRASKA MONDAY EVENING
AND HAVE INTRODUCED SOME MVFR CIGS FOR THE KLBF TERMINAL AFTER 04Z
TUES.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...BUTTLER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
108 AM EST MON JAN 4 2016
.SYNOPSIS...
NORTHWEST FLOW WILL CONTINUE TO DOMINATE THE PATTERN FOR THE NEXT
SEVERAL DAYS WITH THE COLDEST AIR OF THE SEASON EXPECTED TO START
THE FIRST FULL WEEK OF THE NEW YEAR. TEMPERATURES WILL BEGIN TO
MODERATE LATER IN THE WEEK AS HIGH PRESSURE BUILDS EASTWARD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE ARCTIC FRONT IS VERY HARD TO FIND BUT THE OLD RULE OF THUMB
-10C 850MB ISOTHERM IS SETTLING THROUGH SOUTHERN PA AT THIS HOUR.
SNOW SHOWERS ARE VERY CELLULAR AND DISORGANIZED. THE HRRR AND UCAR
ENSEMBLE SUPPORT ONLY ISOLATED MEASURABLE AMOUNTS AS THE OVER-
LAKE TRAJECTORIES SHORTEN UP AND INVERSION HEIGHTS LOWER RAPIDLY
OVERNIGHT. I TRIMMED POPS AND SNOW COVERAGE MORE THAN THE ACTUAL
AMOUNTS WHICH WEREN`T VERY HIGH TO BEGIN WITH.
THE LAURELS WILL LIKELY SEE A SEVERAL HOUR PERIOD OF SNOW...BUT
WITH VIZ AT JST OVER A MILE...IT CAN SNOW FOR A YEAR LIKE THAT AND
NOT AMOUNT TO MUCH. OVERALL TRIMMED ADDITIONAL AMOUNTS DOWN TO
LITTLE MORE THAN AN INCH IN SOME SPOTS.
OVERNIGHT LOWS IN THE TEENS TO LOW 20S WILL FEEL COLD COMPARED TO
WHAT THE SEASON HAS HAD TO OFFER TO DATE...BUT WILL ACTUALLY BE
VERY NEAR NORMAL FOR EARLY JANUARY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
WINDS WILL BECOME MORE NORTHERLY MONDAY...AS HIGH PRESSURE BUILDS
IN AND BRINGS WITH IT THE COLDEST AIR OF THE SEASON TO DATE. 850MB
TEMPS OVER NRN PA WILL BE IN THE NEIGHBORHOOD OF -20C BY MONDAY
AFTERNOON...WHICH HAS NOT BEEN SEEN SINCE LAST WINTER.
AS THE SURFACE HIGH BUILDS EASTWARD AND THE UPPER TROUGH LIFTS
OUT...SNOW SHOWER ACTIVITY SHOULD GRADUALLY TAPER OFF THROUGH THE
DAY ON MONDAY.
IT WILL BE COLD ON MONDAY...WITH TEMPS NOT RISING MUCH FOR MOST
AREAS. HIGHS WILL HOLD IN THE TEENS IN THE NORTH AND THE 20S FOR
THE CENTRAL MTNS...AND A MODERATE BREEZE WILL ONLY ADD TO THE
CHILL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
TUESDAY MORNING WILL BRING THE COLDEST AIR OF THE WINTER
SEASON AS -22C 850MB AIR DIPS INTO NORTHERN PA...BUT A MODERATION
IS IN STORE FOR THE REMAINDER OF THE WEEK.
HIGH PRESSURE CENTERED OVER PENNSYLVANIA TUESDAY MORNING WILL
SLIDE OFF THE ATLANTIC COAST INTO THURSDAY. THIS WILL ALLOW FOR
MODERATING TEMPERATURES BOTH AT THE SURFACE AND ALOFT.
A 500 MB WAVE OVER THE CENTRAL PLAINS WILL LIFT TO THE NORTH LATE
IN THE WEEK. AN AREA OF MOISTURE OVER THE GULF COAST STATES WILL
BE DRAWN NORTH. AT THIS TIME...THE TROUGH AXIS REMAINS TO THE WEST
OF THE FORECAST AREA AS A WEAK LOW DEVELOPS NEAR THE MID ATLANTIC
COAST ON THURSDAY AND FRIDAY. BY SATURDAY...ANOTHER...STRONGER LOW
PRESSURE SYSTEM DEVELOPS OVER THE LOWER MISSISSIPPI VALLEY AND
MOVES NORTHEAST. THE LOW PRESSURE TRACK DIFFERS BETWEEN THE
LONGER RANGE MODELS AND THAT WILL AFFECT THE QPF. DOESN`T SEEM TO
BE ENOUGH COLD AIR IN THE CARDS TO GET EXCITED ABOUT THE PROSPECTS
FOR BIG SNOW.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
CLOUD DECK COVERING ALL BUT SE SLIVER OF CWA THIS EVENING...THOUGH
LOW CLOUDS/RESTRICTIONS CONFINED TO MAINLY NORTHERN AND WESTERN
HIGHER TERRAIN - AIDED BY UPSLOPE FLOW AND CAA.
A COLD FRONT DROPPING INTO NORTHERN PA AT 01Z WILL CONTINUE TO
PUSH SOUTHEASTWARD ACROSS CENTRAL PA TONIGHT...ACCOMPANIED BY
SCTD SNOW SHOWERS AND POSSIBLY A SQUALL MAINLY IMPACTING AREAS
NORTH OF I-80 AND WEST OF I-99. BEHIND THE FRONT...LAKE-EFFECT
AND UPSLOPE SNOW SHOWERS WILL SETTLE IN TO AFFECT PRIMARILY THE
WRN HIGHLANDS /KBFD AND KJST/ OVERNIGHT INTO EARLY MONDAY...
ACCOMPANIED BY REDUCED CIGS AND VSBYS.
CONDITIONS SHOULD GRADUALLY IMPROVE ON MONDAY...AS HIGH PRES
BUILDS IN. VFR CONDITIONS SHOULD BE IN PLACE IN MOST AREAS BY
12Z...WITH WRN HIGHLANDS GRADUALLY IMPROVING THROUGH THE DAY.
AFTER THAT...HIGH PRES WILL REMAIN IN CONTROL THROUGH THURS. THE
NEXT WEATHER MAKER COULD BRING SOME RAIN SHOWERS INTO CENTRAL PA
BY FRI.
OUTLOOK...
MON...REDUCTIONS ACROSS WESTERN HIGHER TERRAIN IN SNOW SHOWERS
AND POTENTIAL SQUALLS. OTHERWISE MAINLY VFR. BREEZY.
TUE-THU...NO SIG WX.
FRI...INCR CLOUDS. SHRA POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/GARTNER
NEAR TERM...LA CORTE/GARTNER
SHORT TERM...GARTNER/EVANEGO
LONG TERM...LA CORTE/TYBURSKI
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
358 AM CST MON JAN 4 2016
.SHORT TERM...
(TODAY-WED NIGHT)
EXPECTING A DRY FORECAST THRU WED NIGHT. ONLY TRUE QUANDARY FOR THE
SHORT TERM PERIOD CENTERS AROUND LOW LEVEL CLOUD DECK MOVING N TO
S ACROSS THE MID STATE AS THESE EARLY MORNING HOURS HAVE PROGRESSED.
THIS LOW LEVEL MOISTURE ADVECTION ASSOCIATED WITH BROAD UPPER LEVEL
TROUGHING INFLUENCES MOVING ACROSS THE REGION. HRRR MODEL SHOWING
MOST OF THIS LOW LEVEL CLOUDINESS HANGING AROUND DURING THE DAY...
AND CAN NOT REALLY ARGUE WHY IT WOULD NOT WITH THE LATEST 08Z KOHX
LAPS SOUNDING SHOWING A PRONOUNCED LOW LEVEL INVERSION IN PLACE
925MB TO 700MB...WITH REALLY NO SIGNIFICANT MIXING SOURCE IN SITE...
UNTIL BULK OF THIS LOW LEVEL MOISTURE SHIFTS EWD AS UPPER LEVEL
TROUGHING INFLUENCES MOVE EWD ALSO...AND DIURNAL HEATING INFLUENCES
LATE IN THE DAY MAY RESULT IN SOME BREAKAGE IN THE CLOUDINESS ACROSS
MAINLY ERN PORTIONS OF THE MID STATE.
A DECENT SFC PRESSURE GRADIENT IS EXPECTED ACROSS THE MID STATE DURING
THE MORNING HRS ALSO. WIND CHILLS DURING THIS TIME PERIOD IN THE LOW
TO MID 20S ARE CERTAINLY NOT OUT THE QUESTION...EVEN UPPER TEENS
POSSIBLE PLATEAU...THRU AT LEAST THE MID MORNING HRS. THUS...THOSE
PARTICIPATING IN OUTDOOR ACTIVITIES THRU THE MID MORNING HOURS...
ESPECIALLY FOR THOSE SCHOOL DISTRICT STARTING SCHOOL AFTER THEIR
WINTER BREAKS...TODAY...WITH CHILDREN/PARENTS WAITING AT SCHOOL
BUS PICKUP ZONES...SHOULD DRESS FOR THESE COLD WX CONDITIONS APPROPRIATELY.
WITH THE POSSIBILITY OF SOME CLOUD BREAKAGE LATE AFTERNOON...A LITTLE
HESITANT IN BEING AGGRESSIVE IN CUTTING DOWN AFTERNOON HIGH TEMPS
BY MULTIPLE DEGREES FROM GUIDANCE...AND DID GO BELOW A FEW DEGREES
BELOW MAV/MET GUIDANCE VALUES...BUT WENT MORE IN LINE WITH 08Z GFS
LAMP VALUES. THUS...HIGHS TODAY WILL BE ONLY IN THE MID 30S...AROUND
FREEZING PLATEAU...10 TO 15 DEGREES COOLER THAN SEASONABLE NORMAL
VALUES. THUS TOO...ON AVERAGE...SOME OF THE COLDEST HIGH TEMPS SO
FAR THIS WINTER SEASON WILL BE EXPERIENCED TODAY ACROSS THE MID STATE.
BUILDING UPPER LEVEL RIDGING INFLUENCES WILL MOVE INTO THE MID STATE
AS TONIGHT PROGRESSES...AND ALONG WITH INFLUENCES FROM ERN GREAT
LAKES CENTERED SFC HIGH PRESSURE SYSTEM...WILL ERODE ANY
REMAINING CLOUDINESS ACROSS THE MID STATE BY THE EARLY EVENING HRS
TONIGHT. THIS WILL RESULT IN MOCLR SKIES ACROSS OUR AREA...WITH
LOWS TONIGHT MAINLY IN THE LOWER 20S...UPPER TEENS PLATEAU.
UPPER LEVEL RIDGING INFLUENCES WILL CONTINUE TO BUILD ACROSS THE AREA...
ALONG WITH INFLUENCES OF SFC HIGH PRESSURE CENTERED ACROSS THE ERN
GREAT LAKES REGION BY TUE MORNING THAT WILL SHIFT TOWARD THE MID
ATLANTIC COASTLINE BY LATE TUE AFTERNOON. THIS WILL PROVIDE FOR A
WARMUP IN AFTERNOON TEMPS TO AROUND SEASONAL NORMAL VALUES BY TUE
AFTERNOON. HIGHS WILL BE MAINLY IN THE UPPER 40S...MID 40S PLATEAU.
LOWS TUE NIGHT WILL REBOUND MAINLY INTO THE LOWER 30S.
THE BRUNT OF THE UPPER LEVEL RIDGING INFLUENCES WILL THEN SHIFT EWD AS
TUE NIGHT THRU WED NIGHT PROGRESS...WITH SFC HIGH PRESSURE INFLUENCES
MOVING INTO THE NE U.S...BUT OTHER THAN A SLOW INCREASE IN ATM MOISTURE
THRU WED NIGHT EXPECTED...LEADING TO A TRANSITION TO MOCLDY SKIES BY
WED NIGHT...DRY CONDITIONS WILL CONTINUE. HIGHS WILL CONTINUE TO WARM
WITH HIGHS NOW APPROACHING TEN DEGREES ABOVE SEASONAL NORMAL VALUES
BY WEDNESDAY AFTERNOON...MAINLY IN THE LOWER 50S. LOWS WED NIGHT
WILL BE MAINLY IN THE MID 40S AND BE AS WARM AS SEASONAL NORMAL HIGHS
FOR THIS TIME OF YEAR.
.LONG TERM...
(THU-SUN)
THURSDAY`S WEATHER MAP WILL FEATURE A NEGATIVELY TILTED SHORTWAVE AXIS
WHICH WILL EXTEND FROM KS SE THROUGH THE LOWER MS VALLEY. PVA TO THE
NORTHEAST OF THIS AXIS WILL BE APPARENT AND SHOWER CHANCES WILL BE
SPREADING NORTHEAST TOWARD THE MID STATE. MEANWHILE...AT THE SFC...A
N-S COLD FRONT WILL BE PUSHING EASTWARD AND OFFER A CONTINUING LOW
CHANCE OF SHOWERS FRIDAY INTO SATURDAY.
SHOWALTER VALUES WILL APPROACH ZERO THU NT AND INTO FRIDAY. HOWEVER...
ISC SUPPORT IS NOT THERE TO INCLUDE ANY THUNDER. WILL THEREFORE OPT TO
KEEP THE ACTIVITY AS RAIN SHOWERS ONLY.
MOVING AHEAD...ON SATURDAY...A SHORTWAVE OVER TX WILL BE TAKING THE
SOUTHERN ROUTE EASTWARD. THIS WILL LEAD TO CYCLOGENESIS OVER THE
NORTHERN GULF. AREA OF BEST THERMAL ADVECTION TO THE EAST OF THE
SFC LOW VARIES FROM MODEL TO MODEL. THUS...TRACKING WILL BE AN
UNCERTAINTY. EURO APPEARS TO BE IN THE MIDDLE...VERSUS THE DGEX
AND GFS...AND TRACKS THE LOW NE OVER EAST TN. THUS...THAT WOULD BE
A MORE FAVORABLE SCENARIO FOR MORE GENEROUS RAINFALL TOTALS. WILL
GO AHEAD AND INCLUDE A 40 TO PERHAPS 50 PERCENT CHANCE OF SHOWERS
FOR SAT NT AND INTO SUNDAY.
FOR THE EXTENDED TEMPS...SOUTHERLY FLOW WILL BE THE RULE THROUGH
SATURDAY. UPPER PATTERN REVEALS ELEVATED HEIGHTS...THEREFORE...LOOK
FOR ABOVE NORMAL TEMPS...TO THE TUNE OF 15 TO 20 DEGREES OR SO.
AS THE SOUTHERN ENERGY SPAWNS CYCLOGENESIS OVER NORTHERN
GULF...WE WILL SEE COOLER AIR RETURN. BY SUNDAY...TEMPS WILL ONLY
BE ABOUT 8- 10 DEGREES ABOVE NORMAL.
A SNEAK PEAK...7 TO 10 DAYS OUT...A SERIES OF CANADIAN SFC HIGHS
WILL PLUNGE SOUTHEASTWARD. THE EURO AND GFS MODELS BOTH CONCUR.
UPPER LEVEL WIND COMPONENT LOOKS NORTHERLY AND THUS...PROBABLY A
BELOW NORMAL PRECIP AND TEMP PATTERN.
&&
.AVIATION...
06Z TAF DISCUSSION.
CLOUD DECK FROM THE NORTH HAS CREPT IN A BIT SOONER THAN EXPECTED
THIS EVENING...AND BROUGHT CIGS TO MVFR AT KCKV. CIGS TO THE NORTH
AND EAST OF KCKV ARE CURRENTLY VFR...BUT ARE VERY CLOSE TO MVFR.
DECIDED TO BRING MVFR CIGS TO KBNA AS WELL FROM AROUND 10Z THROUGH
16Z...AND KEPT MVFR CIGS IN FOR KCSV FROM 08Z THROUGH THE MORNING.
IT STILL LOOKS LIKE VFR CIGS WILL RETURN TO ALL TERMINALS TOMORROW
AFTERNOON...BUT MVFR CIGS MAY HOLD AT KCSV SHOULD THE CLOUD DECK
HOLD OUT. WINDS WILL BE NORTHERLY AT AROUND 10 KNOTS WITH GUSTS TO
AROUND 15 TO 20 KNOTS OR SO MAINLY THROUGH THE EARLY AFTERNOON
BEFORE CALMING DOWN A BIT LATER IN THE AFTERNOON AND EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 37 24 45 25 50 / 0 0 0 0 0
CLARKSVILLE 35 21 44 24 48 / 0 0 0 0 0
CROSSVILLE 31 19 39 19 43 / 10 0 0 0 0
COLUMBIA 35 21 44 24 49 / 0 0 0 0 0
LAWRENCEBURG 35 21 43 23 48 / 0 0 0 0 0
WAVERLY 36 24 45 26 50 / 0 0 0 0 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........21
LONG TERM..................31
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1239 AM EST MON JAN 4 2016
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION OVERNIGHT INTO EARLY
MONDAY...BRINGING MUCH COLDER AIR ALONG WITH SNOW SHOWERS AND
STRONG NORTHWEST WINDS TO THE MOUNTAINS THROUGH MONDAY AFTERNOON.
COLD HIGH PRESSURE FOLLOWS THE FRONT MONDAY NIGHT INTO WEDNESDAY
BEFORE MOISTURE STARTS TO RETURN LATE WEDNESDAY NIGHT INTO
THURSDAY. A COMPLEX LOW PRESSURE SYSTEM WILL PASS TO THE WEST
FRIDAY RESULTING IN WARMER TEMPERATURES ALONG WITH MORE
WIDESPREAD RAINFALL FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 830 PM EST SUNDAY...
LEADING EDGE OF THE LOW CLOUD DECK ASSOCIATED WITH A LEAD SURFACE
TROUGH CONTINUES TO ADVANCE SOUTH INTO THE WESTERN SLOPES AND
SHOULD PUSH SOUTHEAST TOWARD THE BLUE RIDGE BY MIDNIGHT. HOWEVER
MOISTURE REMAINS QUITE LIMITED PER CONTINUED VERY DRY EVENING
SOUNDINGS WITH THE CLOUD SHIELD FADING AT TIMES UPON DROPPING
SOUTH. LACK OF DEEPER MOISTURE ALSO A LIMITING FACTOR IN SNOW
SHOWER DEVELOPMENT THIS EVENING...AND APPEARS WILL HAVE TO WAIT
UNTIL AFTER MIDNIGHT NW TO GET COVERAGE GOING PER LATEST RAP AND
LOCAL RNK-WRF SOLUTIONS. FORECAST SOUNDINGS DO SUPPORT MORE BANDED
NATURE SNOW SHOWERS LATE TONIGHT AS AN UPPER WAVE CROSSES BUT
AGAIN QUESTIONS WITH THE SHALLOW NATURE OF THE MOISTURE COLUMN.
APPEARS BEST POTENTIAL FOR BANDING WILL BE TO THE WEST PER
NAM TRAJECTORIES OFF THE LAKES...AND TO THE NORTH CLOSER TO THE
COLD POOL...WITH LIGHTER UPSLOPE DRIVEN SNOW SHOWERS IN BETWEEN.
THUS HAVE CONTINUED TO DELAY THE ONSET OF POPS A FEW HOURS AND CUT
BACK SOME ON SNOWFALL AMOUNTS ESPCLY GIVEN THE SLOWER ONSET AND
LIKELY OFF/ON NATURE TO THE PRECIP. STILL APPEARS THAT THE FAR NW
RIDGES COULD GET AN INCH OR TWO PENDING BANDS...WITH LESS
ELSEWHERE WESTERN SLOPES...AND MAINLY FLURRIES OUT TOWARD THE BLUE
RIDGE.
OTRW BECOMING MOSTLY CLOUDY WEST OVERNIGHT WITH POPS INCREASING
TO HIGH CHANCE/LIKELYS FAR WEST AND SLIGHT POPS ELSEWHERE OUT TO
THE BLUE RIDGE. MAINLY PARTLY CLOUDY EAST FOR EARLY HIGH CLOUDS
AND SOME SPILLOVER OF STRATO- CU LATE BUT DRY. WIDE RANGE OF TEMPS
ONGOING SHOULD PERSIST AS MIXING/CLOUDS INCREASE BUT THEN DROP
INTO THE UNIFORM LOW/MID 20S WEST. SOME RISES POSSIBLE EAST BEFORE
FALLING LATE AS THE ACTUAL 85H BOUNDARY AND BETTER COLD ADVECTION
ARRIVE BY DAYBREAK.
PREVIOUS DISCUSSION AS OF 315 PM EST SUNDAY...
WHILE MOST OF THE REGION IS ENJOYING SEASONABLE TEMPERATURES AND A
GOOD BIT OF SUN...SATELLITE IMAGERY SHOWS A WALL OF LOW CLOUDS TO
OUR NORTH MAKING STEADY PROGRESS TOWARD THE REGION. THESE CLOUDS
ARE ASSOCIATED WITH A COLD FRONT THAT WILL MOVE THROUGH THE
REGION TONIGHT AND BRING WITH IT MUCH COLDER AIR FOR THE START OF
THE WORKWEEK. BLUSTERY NORTHWEST WINDS CAN ALSO BE EXPECTED BEHIND
THE FRONT THROUGH MONDAY...ADDING A BITE TO THE COLD AND MAKING
OUR RECORD WARM DECEMBER SEEM LIKE A DISTANT MEMORY. EXPECT HIGH
TEMPERATURES ON MONDAY TO ONLY BE AROUND 40 DEGREES ACROSS THE
PIEDMONT WITH READINGS IN THE MID 20S/AROUND 30 WEST OF THE BLUE
RIDGE. WIND CHILLS WILL BE IN THE 20S EAST TO TEENS WEST.
THERE IS A GOOD AMOUNT OF SYNOPTIC LOW LEVEL MOISTURE MOVING IN
BEHIND THE FRONT AND THE MESO MODELS INDICATE POTENTIAL FOR UPSTREAM
LAKE INFLUENCE/STREAMERS AS WELL. ADD IN A GOOD NW UPSLOPE TRAJECTORY
AND UPPER SHORT WAVE SUPPORT...AND LOCATIONS FROM THE BLUE RIDGE
WESTWARD CAN EXPECT FLURRIES TO DEVELOP LATE THIS EVENING WITH THE
FAR WESTERN SLOPES SEEING SOME STEADIER SNOW SHOWERS WITH MINOR
ACCUMULATIONS. FROM TONIGHT THROUGH MONDAY... WESTERN GREENBRIER
IN WV CAN EXPECT ACCUMULATIONS AROUND 2 INCHES WITH AMOUNTS OF AN
INCH OR LESS DOWN THROUGH THE WEST FACES OF THE MOUNTAIN EMPIRE
AND GRAYSON HIGHLANDS OF VA INTO THE NORTHWEST MOUNTAINS OF
NC...AND TRACE AMOUNTS IN FLURRIES OUT TO THE BLUE RIDGE. NO
AMOUNTS WILL EXCEED ADVISORY CRITERIA BUT WILL MENTION IN THE HWO
SINCE THIS IS THE FIRST EVENT OF THE SEASON AND IT WILL BE THE
FIRST DAY BACK FROM BREAK FOR MANY SCHOOL DISTRICTS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 315 PM EST SUNDAY...
SOME LINGERING SNOW SHOWERS OR FLURRIES WILL CONTINUE ACROSS THE
PREFERRED WESTERN UPSLOPE AREAS OF THE FORECAST AREA MONDAY NIGHT
THROUGH THE EVENING HOURS. AS MIDNIGHT APPROACHES...LOW LEVEL WINDS
WILL HAVE VEERED MORE NORTHERLY THAN NORTHWEST...AND BY MORNING BE
NORTHEAST. THIS SERIES OF EVENTS WILL TURN OFF THE UPSLOPE MACHINE
ALLOWING FOR AN END OF PRECIPITATION AND A TREND TOWARDS DECREASING
CLOUDS.
HIGH PRESSURE WILL SETTLE OVER THE REGION BY TUESDAY EVENING...AND
THEN SHIFT NORTHEAST TO OVER PA/NJ BY WEDNESDAY NIGHT. THE RESULT
WILL BE PRIMARILY DRY CONDITIONS THROUGH THIS PORTION OF THE
FORECAST. THE ONE EXCEPTION WILL BE THE FAR SOUTHWEST PART OF THE
AREA. AS THE HIGH SHIFTS NORTHEAST...LOW LEVEL FLOW WILL BECOME EAST
OVER THE COAST OF THE CAROLINAS AND SOUTH OVER OUR REGION. THE
RESULT WILL BE AN INCREASE IN ATLANTIC MOISTURE THAT WILL BRING
INCREASING CLOUDS TO THE ENTIRE REGION...AND THE POTENTIAL FOR SOME
LIGHT RAIN OR LIGHT FREEZING RAIN OVER THE MOUNTAINS AND FOOTHILLS
OF NORTH CAROLINA LATE WEDNESDAY NIGHT.
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL AVERAGE 5 TO
10 DEGREES BELOW NORMAL.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 PM EST SUNDAY...
GUIDANCE VARIES ON THE SPECIFIC TIMING OF FEATURES...AND THE PATH
THESE FEATURES WILL TAKE DURING THIS PORTION OF THE FORECAST.
HOWEVER...THE GENERAL PATTERN IS PROGGED TO BE ONE ASSOCIATED WITH A
TROUGH/CLOSED LOW OVER THE CENTRAL PLAINS STATES HEADING NORTHEAST
INTO THE GREAT LAKES. ON ITS FORWARD FLANKS...A SERIES OF
DISTURBANCES ARE PROGGED TO PROGRESS NORTHEAST FROM THE WESTERN GULF
OF MEXICO TO OVER OR NEAR OUR REGION. THE FIRST IS EXPECTED TO
ARRIVE APPROXIMATELY THURSDAY NIGHT INTO FRIDAY. THIS SECOND HAS
MORE OF A SATURDAY NIGHT INTO SUNDAY WINDOW OF ARRIVAL.
LOW LEVEL TEMPERATURES PROFILES HAVE TRENDED SLIGHTLY WARMER WITH
THE FIRST SYSTEM. WE ALREADY HAD A PRIMARILY RAIN FORECAST DURING
THIS THURSDAY NIGHT/FRIDAY TIME PERIOD. THIS TREND STRENGTHENS THIS
LIKELIHOOD. THE TEMPERATURE PROFILE FOR THE SECOND SYSTEM IS MUCH
MORE IN QUESTION. THE GFS SOLUTIONS KEEPS THE GREAT LAKES LOW/TROUGH
DISTINCT FROM THE SOUTHERN STREAM SYSTEM...WITH A MORE PROGRESSIVE
SOLUTION THAT ALLOWS COLDER AIR TO WORK ITS WAY INTO WESTERN PARTS
OF THE AREA BY SUNDAY AFTERNOON. THE ECWMF SOLUTION TRIES TO MERGE
THE TWO SYSTEMS...ALLOWING FOR A SLOW DOWN...AND A MILDER LOW LEVEL
TEMPERATURE PROFILE TO EXIST FOR A LONGER PERIOD OF TIME. OUR
FORECAST WILL REFLECT A CONSENSUS OF THESE TWO.
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND WARMER
EACH DAY AND BE SOME 5 TO 10 DEGREES ABOVE NORMAL BY SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 1233 AM EST MONDAY...
EXPECT MVFR CIGS OVER THE MTNS FROM BCB TO BLF/LWB...WITH POSSIBLE
LIGHT SNOW SHOWERS OR FLURRIES THROUGH MIDDAY. THINK ROA/LYH WILL
STAY VFR WITH BKN CIGS AROUND 4KFT. WINDS WILL PICK UP BEHIND THE
SHORTWAVE DURING THE DAY MONDAY WITH GUSTS OVER 20KTS
COMMON...ESPECIALLY INTO ROA/BCB. THE CLOUDS WILL LINGER OVER THE
MTNS INTO THE AFTERNOON BUT SHOULD RISE TO VFR BY 20Z. VFR
EXPECTED THEREAFTER WITH WINDS SUBSIDING SOMEWHAT IN THE EVENING.
.EXTENDED AVIATION DISCUSSION...
VFR EXPECTED INTO EARLY WEDNESDAY...THEN MODELS VARY ON INFLUX OF
MOISTURE FROM THE SOUTH...WITH THE NAM QUICKEST IN BRINGING BACK
LOWER CIGS. THINK SHOULD STAY VFR THROUGH MOST OF WED INTO EARLY
WED NIGHT.
LOW LEVEL MOISTURE WILL THEN INCREASE LATER WEDNESDAY NIGHT INTO
THURSDAY. THIS MAY BRING MVFR CONDITIONS FOR LATER WEDNESDAY INTO
THURSDAY ALONG WITH SOME SPOTTY VERY LIGHT PRECIP ESPCLY ALONG THE
BLUE RIDGE BY EARLY THURSDAY MORNING. LOW LEVEL MOISTURE WITHIN
THE WEDGE LOOKS TO KEEP AT LEAST PERIODS OF SUB-VFR IN PLACE FOR
MUCH OF THURSDAY ALTHOUGH DEEP MOISTURE LOOKS TOO LIMITED FOR MUCH
RAINFALL OUTSIDE OF SPOTTY DRIZZLE OR SPRINKLES. MORE IN THE WAY
OF WIDESPREAD RAINFALL INCLUDING MVFR/IFR CONDITIONS APPEARS MORE
LIKELY LATER THURSDAY NIGHT INTO FRIDAY AHEAD OF A WARM FRONT
APPROACHING FROM THE SOUTHWEST LATE IN THE DAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/MBS
NEAR TERM...JH/MBS
SHORT TERM...DS
LONG TERM...DS
AVIATION...JH/MBS/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
248 AM CST MON JAN 4 2016
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 248 AM CST MON JAN 4 2016
THE FIRST CONCERN IS WITH WHAT THE CLOUD COVER IS GOING TO DO
TODAY. A NARROW AREA OF CLEARING HAS WORKED INTO THE WESTERN
SECTIONS BUT IS SURROUNDED BY THE LOW CLOUDS BOTH TO THE WEST AND
EAST. THE 04.06Z RAP 0.5KM RELATIVE HUMIDITY SUGGESTS THE CLOUDS
TO THE EAST OF THIS CLEARING SLOT WILL EVENTUALLY START MOVING
BACK TO THE WEST SO THAT THE CLOUDS COVER THE ENTIRE FORECAST AREA
AGAIN BY 12Z. HAVE TRENDED TOWARD THIS SOLUTION TO START THE DAY.
THE NEXT CONCERN IS WITH A THINNING AREA OF CLOUDS OVER NORTHEAST
WISCONSIN THAT THE RAP SUGGEST THEN WORKS INTO CENTRAL WISCONSIN
BY MID MORNING AND THE WORKS WEST ACROSS MOST OF THE AREA THROUGH
THE DAY. HAVE TRIED TO HANDLE THIS TREND BY SHOWING A DECREASE IN
THE CLOUDS OVER THE EASTERN SECTIONS DURING THE MORNING WITH A
DECREASING CLOUDS TREND FOR THE REST OF THE AREA THROUGH THE
AFTERNOON.
THE NEXT CHANCE FOR PRECIPITATION WILL COME WEDNESDAY AFTERNOON.
THE UPPER LEVEL RIDGE AXIS WILL SLIDE ACROSS THE REGION MONDAY
NIGHT AND TUESDAY SETTING UP A SOUTHWEST FLOW ALOFT. A SHORT WAVE
TROUGH WILL COME OUT THE ROCKIES AND MOVE ACROSS THE AREA
WEDNESDAY AFTERNOON AND NIGHT. THIS DOES NOT LOOK TO BE THAT
STRONG OF A SHORT WAVE TROUGH AND THE 04.00Z GFS ONLY SHOWS SOME
WEAK PV ADVECTION IN THE 500-300 MB LAYER. NOT A LOT OF
THERMODYNAMIC FORCING EITHER AS THERE IS NO FRONTOGENESIS AND
ABOUT 1 TO 3 UBAR/S OF UP GLIDE ON THE 285K ISENTROPIC SURFACE. IT
LOOKS LIKE A LOT OF THE FORCING FROM THIS WAVE WILL GO INTO
SATURATING THE COLUMN...WHICH SHOULD TAKE UNTIL THE AFTERNOON TO
OCCUR...AND THEN ONCE SATURATION IS ACHIEVED...THERE IS NOT A LOT
OF LIFT LEFT FOR PRECIPITATION PRODUCTION. WITH SATURATION NOT
OCCURRING UNTIL AFTERNOON...REMOVED THE SMALL SNOW CHANCES FROM
WEDNESDAY MORNING AND THEN KEPT THEM IN THE 20 TO 40 PERCENT RANGE
FOR THE AFTERNOON. THE BEST CHANCES FOR PRECIPITATION WILL
PROBABLY OCCUR WEDNESDAY EVENING WHEN THE WEAK FORCING FROM THE
WAVE AND ISENTROPIC UP GLIDE CAN WORK ON THE SATURATED COLUMN TO
PRODUCE SOME LIGHT SNOW AND RAISED THE CHANCES UP TO 50 PERCENT
ACROSS THE NORTHERN SECTIONS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 248 AM CST MON JAN 4 2016
THURSDAY LOOKS TO BE TRANSITION DAY WITH THE AREA BETWEEN SYSTEMS.
AS THE SHORT WAVE TROUGH FROM WEDNESDAY NIGHT MOVES OFF TO THE
EAST...THERE SHOULD BE A PERIOD OF SHORT WAVE RIDGING ALOFT THAT
MOVES ACROSS THE AREA. THE ISENTROPIC UP GLIDE DROPS OFF TO
VIRTUALLY NOTHING AS THE BEST AREA OF WARM AIR ADVECTION SHIFTS
EAST WITH THE DEPARTING SHORT WAVE TROUGH. IF THERE IS
PRECIPITATION AROUND THURSDAY...HAVE CONCERNS ON WHAT TYPE IT WILL
BE. THE GFS SOUNDINGS SHOW A LACK OF ICE IN THE CLOUDS AS DRYING
ALOFT OCCURS WITH THE SHORT WAVE RIDGING. THIS COULD LEAD TO A
PERIOD OF SOME FREEZING DRIZZLE UNTIL TEMPERATURES REACH THE
FREEZING MARK IN THE AFTERNOON. FOR NOW...WILL STAY WITH RAIN OR
SNOW BUT LATER FORECASTS MAY HAVE TO START CONSIDERING OTHER
PRECIPITATION TYPES.
THE NEXT SHORT WAVE TROUGH COMING TOWARD THE AREA IN THE SOUTHWEST
FLOW IS HANDLED PRETTY SIMILARLY BY THE GFS AND 04.00Z ECMWF WITH
THEM COMING INTO BETTER AGREEMENT THAT THIS SYSTEM SHOULD TRACK TO
THE SOUTH OF THE AREA. THERE ARE STILL MINOR DIFFERENCES ON THE
TIMING AND STRENGTH OF THIS SYSTEM...BUT LOOKING AT THE GFS
FORECAST SOUNDINGS...THE FARTHER SOUTH TRACK SHOULD NOT BRING IN
MUCH WARM AIR ALOFT OR PRESENT PROBLEMS WITH ICE IN THE CLOUDS.
THIS SHOULD KEEP THE PRECIPITATION TYPES CONTROLLED BY THE LOW
LEVEL THERMAL STRUCTURE AND WITH HIGHS FRIDAY EXPECTED TO BE THE
MIDDLE TO UPPER 30S...SHOULD SEE A MIX OF RAIN/SNOW OR ALL RAIN BY
THE AFTERNOON. ANOTHER SHORT WAVE TROUGH LOOKS TO TAKE A VERY
SIMILAR TRACK FOR SOME LOW END PRECIPITATION CHANCES FRIDAY NIGHT
INTO SATURDAY. THE MODELS THEN DIVERGE ON HOW STRONG THE NORTHERN
STREAM FLOW WILL BE WITH THE ECMWF WRAPPING UP A LARGE UPPER LEVEL
LOW OVER SOUTHERN CANADA WHILE THE GFS IS CONSIDERABLY WEAKER
WITH THIS FLOW AND KEEPS THE NORTHERN STREAM ENERGY STRUNG OUT IN
A TROUGH FROM HUDSON BAY ACROSS THE NORTHERN GREAT LAKES INTO THE
NORTHERN ROCKIES. BOTH MODELS AGREE THAT COLDER AIR WILL ARRIVE
OVER THE WEEKEND ONCE THE SURFACE LOW GOES BY WITH THE FRIDAY
NIGHT/SATURDAY SHORT WAVE TROUGH. SINCE THE ECMWF IS STRONGER WITH
THE NORTHERN STREAM IT SPREADS IN MORE COLD AIR AND SUGGESTS THE
HIGHS SUNDAY WOULD ONLY BE IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO WHILE THE GFS IS SOMEWHAT WARMER WITH HIGHS IN THE SINGLE
DIGITS AND TEENS ABOVE ZERO. FOR NOW...HAVE NOT GONE THAT COLD
WITH THE TEMPERATURES...BUT DID TREND THEM BELOW THE MODEL
CONSENSUS...ESPECIALLY ACROSS THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1143 PM CST SUN JAN 3 2016
COMPLEX CEILING/VISIBILITY FORECAST CONTINUES AT KRST THROUGH AT
LEAST 04.18Z. CURRENT CLEAR SKIES ARE EXPECTED TO ABRUPTLY GIVE
WAY TO LOW IFR CEILINGS BY 04.09Z AS STRATUS ACROSS SOUTH-CENTRAL
MN MOVE EAST OVERNIGHT. WITH THESE LOW CLOUDS...VISIBILITY WILL
ALSO DROP AT LEAST INTO THE MVFR RANGE....POSSIBLY LOWER IF FOG
CAN FORM. LOW CLOUDS EXPECTED TO HANG TOUGH THROUGH MONDAY MORNING
AS LOW-LEVEL FLOW WEAKENS WITH APPROACHING SURFACE HIGH. SHOULD
SEE SOME SCATTERING BY MONDAY AFTERNOON...BUT SOMETHING TO WATCH.
EXPECT VFR CONDITIONS AT KLSE THROUGH THE PERIOD WITH OVC035
SLOWLY SCATTERING OUT TO MOSTLY CLEAR SKIES BY MONDAY AFTERNOON.
LIGHT NORTHWEST WINDS AT BOTH TAF AIRFIELDS WILL BECOME LIGHT AND
VARIABLE MONDAY MORNING...AND THEN SHIFT TO THE SOUTHEAST MONDAY
AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
425 AM MST MON JAN 4 2016
.SYNOPSIS...A SERIES OF WET STORM SYSTEMS WILL BRING VALLEY RAIN...
MOUNTAIN SNOW AND BELOW AVERAGE TEMPERATURES THIS WEEK.
&&
.DISCUSSION...A NEGATIVELY TILTED TROUGH AXIS EXTENDED FROM WEST OF
THE NRN CALIFORNIA COAST NEAR 40N/130W SEWD INTO CENTRAL BAJA
CALIFORNIA. A CYCLONIC CIRCULATION FEATURE WAS ALSO NEAR THE SRN
CALIFORNIA/NRN BAJA CALIFORNIA COASTS...AND A FEW LIGHTNING STRIKES
HAVE BEEN DETECTED IN THE VICINITY OF THIS FEATURE DURING THE PAST
1-2 HOURS.
THE 04/12Z NAM/GFS/ECMWF/CMC REMAINED QUITE CONSISTENT VERSUS THEIR
RESPECTIVE SOLUTIONS FROM 24-48 HOURS AGO REGARDING THE PRECIP/TEMP
SCENARIO FOR SE ARIZONA INTO NEXT WEEKEND. A SLIGHT CHANCE OF
SHOWERS EXISTS THIS MORNING FROM TUCSON EWD TO THE NEW MEXICO
BORDER. MEANWHILE...SCATTERED TO NUMEROUS SHOWERS ARE FORECAST TO
OCCUR LATER THIS MORNING MAINLY ACROSS WESTERN PIMA COUNTY AND THE
TOHONO O`ODHAM NATION.
NUMEROUS SHOWERS WILL THEN MOVE EWD/NEWD ACROSS THE AREA THIS
AFTERNOON AND EVENING. THE BEST CHANCE FOR MEASURABLE RAINFALL
ACROSS THE TUCSON METRO AREA AS PER VARIOUS HRRR SOLUTIONS AND THE
04/00Z UNIV OF AZ WRF-NAM AND WRF-GFS APPEARS TO BE ABOUT FROM NOON
TODAY INTO THIS EVENING. SNOW LEVELS BY THIS EVENING WILL REMAIN
FAIRLY HIGH...GENERALLY RANGING FROM 7000-8000 FEET. AT THIS TIME...
APPEARS THAT SNOW ACCUMULATIONS WILL AVERAGE FROM 3-7 INCHES ABOVE
7500 FEET. THESE AMOUNTS ARE EXPECTED TO REMAIN JUST BELOW SNOW
ADVISORY CRITERIA. PRECIP COVERAGE SHOULD DECREASE SOMEWHAT LATE
TONIGHT AND ESPECIALLY TUE AS A LOW AMPLITUDE SHORTWAVE RIDGE MOVES
ACROSS THE AREA. THUS...POPS TUE AFTERNOON ARE MOSTLY IN THE SLIGHT-
CHANCE CATEGORY...ALTHOUGH A CHANCE OF SNOW SHOWERS CONTINUES TUE
AFTERNOON ACROSS THE WHITE MOUNTAINS.
THE SECOND SHORTWAVE TROUGH WILL ENHANCE PRECIP CHANCES TUE
EVENING... AND ESPECIALLY LATE TUE NIGHT INTO WED. THUS...EXPECT
SCATTERED TO NUMEROUS SHOWERS TO OCCUR WED...WITH SNOW LEVELS
LOWERING TO 6000-7000 FEET WED AFTERNOON. PRECIP CHANCES WILL
DECREASE SOMEWHAT WED EVENING...BUT WILL INCREASE AGAIN LATE WED
NIGHT AND THUR AS THE THIRD SHORTWAVE TROUGH MOVES EWD ACROSS THE
AREA. MOISTURE WILL REMAIN SUFFICIENT TO JUSTIFY CHANCE-CATEGORY
POPS ACROSS MUCH OF THE AREA THUR NIGHT.
THE FOURTH SHORTWAVE TROUGH CONTINUES TO BE PROGGED VIA THE GFS/
ECMWF/CMC TO MOVE EWD ACROSS SE ARIZONA FRI. THUS...SCATTERED TO
PERHAPS NUMEROUS SHOWERS ARE FORECAST TO OCCUR FRI...AND SCATTERED
SHOWERS WILL LIKELY CONTINUE ESPECIALLY FROM TUCSON EWD TO THE NEW
MEXICO BORDER FRI NIGHT. THE MAIN CONCERN REGARDING THIS SYSTEM WILL
BE THE POTENTIAL FOR SIGNIFICANT SNOWFALL...ESPECIALLY AT LOWER
ELEVATIONS. SNOW LEVELS BY EARLY SAT MORNING ARE EXPECTED TO BE
AROUND 4500 FEET.
NORTHWEST FLOW ALOFT SAT SHOULD TRANSLATE INTO SOMEWHAT DRIER
CONDITIONS ACROSS THE AREA. HOWEVER...ENOUGH MOISTURE SHOULD STILL
PREVAIL TO JUSTIFY A SLIGHT CHANCE OF VALLEY RAIN/ MOUNTAIN SNOW
SHOWERS SAT MAINLY FROM TUCSON EWD TO THE NEW MEXICO BORDER.
THEREAFTER...GFS/ECMWF WERE SIMILAR WITH DEPICTING YET ANOTHER
SHORTWAVE TROUGH TO MOVE SEWD ACROSS THE GREAT BASIN AND INTO NRN
ARIZONA. THIS SCENARIO IS A DEPARTURE FROM PREVIOUS SOLUTIONS.
GIVEN THIS DEVIATION...HAVE OPTED TO MAINTAIN DRY CONDITIONS ACROSS
THIS FORECAST AREA SAT NIGHT-SUN...AND AWAIT FURTHER MODEL SOLUTIONS
BEFORE ADJUSTING POPS UPWARD.
HIGH TEMPS TODAY WILL BE ABOUT 5-15 DEGS COOLER VERSUS MON...AND THE
MOST SIGNIFICANT COOLING TODAY WILL PREVAIL FROM TUCSON WWD INTO THE
WRN DESERTS. SLIGHTLY WARMER TEMPS WILL OCCUR FOR MOST LOCALES TUE.
A COOLING TREND WILL THEN PREVAIL WED-FRI...WITH HIGH TEMPS FRI TO
BE NEARLY 10-15 DEGS F BELOW NORMAL ACROSS THE AREA. A VERY MODEST
WARMING TREND IS ON TAP THIS WEEKEND.
&&
.AVIATION...VALID THRU 05/12Z.
SCT-BKN CLOUDS 8-12K FT AGL WITH BKN-OVC CIRRUS ABOVE. CLOUD DECKS
WILL CONTINUE TO LOWER THROUGHOUT THE DAY TODAY. EXPECT SCT-NUMEROUS
VALLEY SHRA AND MOUNTAIN SHSN TO OCCUR MID-MORNING MAINLY WEST OF
KTUS AND SPREADING EASTWARD ACROSS SE ARIZONA THIS AFTERNOON AND
CONTINUING INTO TONIGHT. MVFR CONDITIONS WILL OCCUR WITH THE HEAVIER
SHOWERS AND NEAR TERRAIN. SELY SURFACE WIND AT 12-15 KTS WITH GUSTS
TO AROUND 25 KTS WILL CONTINUE AT KTUS THIS MORNING. SPEEDS WILL
DECREASE TO GENERALLY LESS THAN 12 KTS EARLY THIS AFTERNOON.
ELSEWHERE...SELY/SLY SURFACE WIND AT 10-15 KTS WILL PERSIST THROUGH
THE DAY WITH NORMAL DIURNAL TRENDS RESUMING AFTER SUNSET TONIGHT.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...PERIODS OF VALLEY RAIN AND MOUNTAIN SNOW ALONG WITH
BELOW NORMAL TEMPERATURES WILL OCCUR THROUGH FRIDAY. LINGERING
SHOWERS ARE EXPECTED MAINLY EAST OF TUCSON SATURDAY FOLLOWED BY DRY
CONDITIONS AREA-WIDE SUNDAY. ELEVATED SOUTHEASTERLY 20-FT WINDS WILL
OCCUR TODAY ESPECIALLY THROUGH THE GILA VALLEY. LIGHT TERRAIN-DRIVEN
WINDS WITH PERIODIC AFTERNOON GUSTINESS IS THEN EXPECTED FOR THE
REMAINDER OF THE WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRANCIS
AVIATION/FIRE WEATHER...FRENCH
AREA FORECAST DISCUSSION
NWS ALBANY NY
936 AM EST MON JAN 4 2016
.SYNOPSIS...
THE COLDEST AIR MASS OF THE SEASON WILL BE OVER THE
REGION TODAY THROUGH TUESDAY. ASIDE FROM WIDELY SCATTERED SNOW
SHOWERS THROUGH MORNING...MAINLY OVER THE HIGHER TERRAIN EAST OF
ALBANY INTO THE EASTERN CAPITAL REGION...IT WILL BE MAINLY DRY
THROUGH THIS PERIOD. TEMPERATURES WILL MODERATE BACK TO SEASONAL
LEVELS BY THE MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 936 AM EST...A MESOSCALE CONVERGENCE BOUNDARY /SOME
SIMILARITIES TO MOHAWK-HUDSON CONV/ WILL CONTINUE TO PUSH S/SE
ACROSS THE CAPITAL REGION...AND BERKSHIRES THIS MORNING AND
WEAKEN. SCATTERED SNOW SHOWERS AND FLURRIES CONTINUE WITH THIS
BOUNDARY WITH SOME UPSLOPEN ENHANCEMENT OVER THE NRN TACONICS AND
NRN BERKSHIRES. THE LATEST HRRR IS FINALLY CATCHING UP...AND
SHOWING THIS FEATURE. IT SHOULD WEAKEN OVER THE NEXT FEW HOURS
WITH SOME COATINGS TO QUARTER INCH AMOUNTS BEFORE FALLING APART.
STRONG COLD ADVECTION CONTINUES OVER THE FCST AREA WITH TEMPS
FALLING INTO THE TEENS AND SINGLE DIGITS FROM THE CAPITAL REGION
NORTH AND WEST. NOT MUCH RECOVERY IS EXPECTED TODAY WITH HIGHS IN
THE TEENS TO M20S. WIND CHILLS WILL BE IN THE 10 ABOVE TO 10 BELOW
RANGE TODAY.
THIS LOOKS TO BE FIRST DAY WHERE OFFICIALLY THE HIGH TEMPERATURE
WILL NOT BE ABOVE FREEZING THIS WINTER SEASON AT ALBANY.
THIS WILL MAKE IT THE LATEST SUCH OCCURRENCE EVER...EASILY
BREAKING THE OLD RECORD FOR THE LATEST FREEZING DAY...
WHICH WAS CHRISTMAS DAY 2012.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
TONIGHT...THE SKY WILL BE CLEAR TO PARTLY CLOUDY AS SURFACE
HIGH PRESSURE BUILDS INTO THE REGION. IT WILL BE DRY
BUT BECOMING FRIGID. A BREEZE IN THE EVENING LOOKS TO DIMINISH
OVERNIGHT YIELDING TO GOOD RADIATIONAL COOLING. AREAS THAT WILL SEE
A SNOW PACK OVER AN INCH LOOK TO GET CLOSE TO OR EVEN A BIT
BELOW ZERO. AREAS FOR THE IMMEDIATE CAPITAL REGION SOUTHWARD
WILL SEE LOW TEMPERATURES IN THE SINGLE NUMBERS.
WITH THE DIMINISHING WIND IT LOOKS RIGHT NOW AS IF MOST AREAS
WILL NOT SEE WIND CHILLS REACHING WIND ADVISORY LEVELS BUT IT
WILL BE CLOSE.
THIS WILL BE BY FAR THE COLDEST READINGS OF THE WINTER THUS FAR
THE COLDEST SINCE MARCH 8TH OF LATE YEAR.
HIGH PRESSURE WILL BUILD TO OUR SOUTH ON TUESDAY...ALLOWING THE
FLOW TO BEGIN TO MORE SOUTHWESTERLY. H850 TEMPS ON TUESDAY
LOOK TO WARM PAST -10C...AND THEN WARM TO AROUND 0C BY
LATER WEDNESDAY.
SUNSHINE ON TUESDAY WILL ALLOW TEMPERATURES TO REACH BACK INTO THE 20S
FROM ABOUT GLENS FALLS SOUTHWARD. THE ADIRONDACKS AND SOUTHERN GREENS
WILL LIKELY TOP OUT ONLY IN THE TEENS.
BY TUESDAY NIGHT...THERE LOOKS TO BE SOME WARM AIR
ADVECTION AND ENOUGH OF A SOUTHERLY BREEZE TO KEEP
TEMPERATURES FROM FALLING A WHOLE LOT...
GENERALLY BACK INTO OR HOLDING IN THE TEENS...
ALTHOUGH A FEW SHELTERED VALLEYS WITH SNOW COVER
COULD EASILY DIP INTO THE SINGLE DIGITS.
WEDNESDAY...WITH MORE SUNSHINE AND A CONTINUED
SOUTH TO SOUTHWESTERLY BREEZE...TEMPERATURES LOOK TO MODERATE
BACK INTO THE 30S MOST AREAS.
WEDNESDAY NIGHT...HIGH PRESSURE WILL STILL BE OUR SOUTH. LOWS THAT
NIGHT WILL BE A TRICKY TO FORECAST. IF THE WIND DIMINISHES AND THE SKY
IS MOSTLY CLEAR...TEMPERATURES COULD EASILY GET AS COLD AS TUESDAY
NIGHT. HOWEVER...IF WE PICK UP MORE IN THE WAY OF WARM AIR ADVECTION
CLOUDS AND HOLD ONTO A LIGHT SOUTHERLY BREEZE...OVERNIGHT LOW TEMPERATURES
MIGHT NOT FALL OUT OF THE 20S. RIGHT NOW...TOOK THE COMPROMISE SOLUTION
WHICH YIELDS LOW TEMPERATURES TEENS IN OUR NORTHERN AREAS...NEAR 20 ALBANY
SOUTHWARD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
HIGH CONFIDENCE IN FORECAST THURSDAY AND FRIDAY. DECREASING
CONFIDENCE IN FORECAST AS WE GO FROM SATURDAY INTO SUNDAY.
CONTINUED QUIET WEATHER EXPECTED THURSDAY AND FRIDAY WITH ABOVE NORMAL
TEMPERATURES AS HIGH PRESSURE CONTROLS OUR WEATHER. LOWS IN THE
TEENS AND TWENTIES AND HIGHS GENERALLY IN THE 30S WITH SOME TWENTIES
IN THE HIGHEST TERRAIN.
BY FRIDAY NIGHT A STORM SYSTEM WILL BE MOVING INTO THE WESTERN GREAT
LAKES WITH A WARM FRONT APPROACHING THE ALBANY FORECAST AREA. OVER
RUNNING PRECIPITATION IS EXPECTED FRIDAY NIGHT AND SATURDAY.
PRECIPITATION TYPE BASED ON 00Z GFS AND 00Z/EURO USING TOP DOWN
METHODOLOGY PRODUCES A MIXED BAG. INITIALLY STARTING AS SNOW AND
SLEET FRIDAY NIGHT...TRANSITIONING TO SLEET AND FREEZING RAIN EARLY
SATURDAY...TO MOSTLY RAIN BY LATER SATURDAY.
MODEL SOLUTIONS START TO DIVERGE BY LATER SATURDAY. BOTH MODELS HAVE
THE WAVE MOVING THROUGH THE GREAT LAKES BUT MAIN DIFFERENCE IS THAT
00Z/GFS SOLUTION IS ABOUT 300 MILES EAST OF 00Z/EURO WITH TRACK OF
SURFACE WAVE. THE TRAILING COLD FRONT IS ALSO ABOUT 300 MILES
FURTHER EAST IN THE 00Z/GFS. THIS HAS IMPLICATIONS FOR SUNDAY
BECAUSE BOTH MODELS HAVE SECONDARY LOW DEVELOPMENT ALONG THE
TRAILING COLD FRONT. THIS LOW DEEPENS AS IT MOVES FROM THE SOUTHEAST
U.S. NORTH NORTHEASTWARD. 00Z/EURO WOULD TRACK THE LOW WEST OF
INTERSTATE 81 ACROSS LAKE ONTARIO BY MONDAY MORNING...WHILE 00Z/GFS
HAS THE LOW MOVING SOUTHEAST OF CAPE COD. QUITE A SPREAD.
TEMPERATURES SATURDAY AND SUNDAY EXPECTED ABOVE NORMAL WITH LOWS
20S TO LOW 30S AND HIGHS 30S TO NEAR 40.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD ENDING 06Z TUESDAY.
LAKE EFFECT SNOW SHOWERS COULD BRIEFLY REDUCE CONDITIONS TO MVFR
AT ALL THE TAF SITES EXCEPT KPOU THROUGH THE MORNING PEAK.
OTHERWISE VFR CIGS LOOK TO BECOME SCATTERED LATER TODAY.
A WEST WIND WILL ULTIMATELY BECOME NORTH AT
ALL THE TAF SITES LATER THIS MORNING.
THE WIND WILL AVERAGE AROUND 10KTS...BUT GUST OVER 20KTS
THROUGH AT LEAST MIDDAY AT TIMES.
OUTSIDE OF THE SNOW SHOWERS...VISIBILITY WILL BE UNRESTRICTED TODAY.
OUTLOOK...
TUESDAY NIGHT THROUGH FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN...SLEET.
SATURDAY: HIGH OPERATIONAL IMPACT. LIKELY RA...SLEET.
&&
.HYDROLOGY...
NO HYDRO ISSUES ARE ANTICIPATED THROUGH THE NEXT 5 DAYS.
ASIDE FROM SOME SNOW SHOWERS...MAINLY DRY WEATHER IS EXPECTED
THROUGH MUCH OF THIS WORK WEEK.
COLDER TEMPS WILL CONTINUE TO ALLOW FOR THE RIVERS AND STREAMS TO
SLOWLY RECEDE...WITH SOME ICE FORMATION MONDAY AND TUESDAY AS EVEN
COLDER AIR MOVES IN.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION LOOKS TO BE FRIDAY
NIGHT AND SATURDAY. AT THIS POINT THIS LOOKS LIKE A POTPOURRI
OF PRECIPITATION TYPES INCLUDING SOME RAIN MAINLY SOUTH.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/WASULA
NEAR TERM...HWJIV/WASULA
SHORT TERM...HWJIV
LONG TERM...SND
AVIATION...HWJIV
HYDROLOGY...HWJIV/NAS
AREA FORECAST DISCUSSION...CORRECTED
NWS TAMPA BAY RUSKIN FL
955 AM EST MON JAN 4 2016
.UPDATE (REST OF TODAY THROUGH TUESDAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOW AN AMPLIFIED UPPER LEVEL
PATTERN IN PLACE OVER THE CONUS. POTENT SHORTWAVE DISTURBANCE IS
ARRIVING OVER SOUTHERN CALIFORNIA/BAJA REGION...FOLLOWED QUICKLY
DOWNSTREAM BY HIGH AMPLITUDE RIDGING OVER THE INTER-MOUNTAIN WEST
AND CENTRAL PLAINS. THE NORTHERN STREAM THEN DIPS RAPIDLY ONCE
AGAIN INTO A SHARP AND COLD TROUGH DIGGING THROUGH THE GREAT
LAKES/NORTHEAST/MID-ATLANTIC STATES. SHORTWAVE ENERGY AT THE BASE
OF THIS EASTERN CONUS TROUGH IS JUST NOW PASSING TO OUR
NORTH...OFF THE GA/NE FLORIDA COAST. LARGE SCALE SYNOPTIC
FORCING/DEEP LAYER Q-VECTOR CONVERGENCE AHEAD OF THIS SHORTWAVE
HAS SHIFTED EAST AND SOUTHEAST OF OUR FORECAST AREA...AND THE LAST
OF THE LIGHT SHOWERS HAVE EXITED THE FORT MYERS/HIGHLANDS COUNTY
AREAS. A MUCH DRIER TROP COLUMN IS NOW ARRIVING FROM THE WEST AND
NORTHWEST. THE 12Z KTBW SOUNDING PROFILE STILL HAD A DECENT
MOISTURE PROFILE THROUGH ABOUT 500MB BEFORE REACHING THE
SUBSIDENCE INVERSION BEHIND THE TROUGH AXIS AND BECOMING
SIGNIFICANTLY DRIER ABOVE. HOWEVER...LOOKING UPSTREAM AT THE
TALLAHASSEE SOUNDING...WHICH HAD THE SUBSIDENCE INVERSION AROUND
700MB...AND MUCH DRIER AIR BETWEEN 700-500MB...WOULD ASSUME SOME
OF THIS MID/LOWER LEVEL MOISTURE THAT WAS IN PLACE EARLIER THIS
MORNING ACROSS THE CENTRAL FL PENINSULA HAS ALREADY SCOURED OUT
SINCE THE BALLOON SAMPLED THE AIRMASS. THIS DRYING OF THE COLUMN
WILL CONTINUE THROUGH THE REMAINDER OF THE DAY...AND ABUNDANT
SUNSHINE FOR ALL THIS AFTERNOON IS IN THE FORECAST.
THE AIRMASS ARRIVING BEHIND THE FRONT IS NOT ALL THAT COLD
(ESPECIALLY FOR THE TIME OF YEAR)...HOWEVER AFTER THE WARMTH OF
DECEMBER...IT CERTAINLY FEELS LIKE A BIG CHANGE. DESPITE THE
ABUNDANT SUNSHINE TODAY...HIGH TEMPERATURES THIS AFTERNOON SHOULD
END UP GENERALLY A COUPLE OF DEGREES BELOW NORMAL. HIGHS RANGE
FROM THE LOWER 60S UP NORTH TOWARD LEVY/CITRUS COUNTIES TO THE
UPPER 60S SOUTH TOWARD THE FORT MYERS AREA.
TONIGHT APPEARS AS THOUGH IT WILL BE THE COLD NIGHT FOR THE WEEK.
HIGH PRESSURE SETS UP WELL TO OUR NORTH ALLOWING FOR A COOL
NORTHERLY FLOW DOWN THE SPINE OF THE PENINSULA TO CONTINUE. THE
POSITION OF THE HIGH KEEPS THE GRADIENT TIGHT ACROSS THE ENTIRE
AREA...AND IT IS UNLIKELY THAT DECOUPLING OF THE BOUNDARY LAYER WILL
OCCUR...EVEN OVER THE FAR NORTHERN NATURE COAST ZONES.
THEREFORE...NOT LOOKING FOR MUCH IN THE WAY OF RADIATIVE PROCESSES
OVERNIGHT...BUT RATHER A PURE ADVECTION AIRMASS NIGHT. ONE OF THE
COLDER NIGHT OF THE SEASON SO FAR IS LIKELY...ALTHOUGH GENERALLY
SPEAKING MOS TENDS TO BE A BIT ON THE COLD SIDE WITH ADVECTION
EVENTS. MOS WOULD SUGGEST THAT TEMPS MAY APPROACH FREEZING TOWARD
DAWN ACROSS PARTS OF LEVY COUNTY. BASED ON THE MOS BIAS WILL KEEP
TEMPS IN THE MID 30S AROUND CHIEFLAND FOR NOW AND RE-EVALUATE WITH
THE AFTERNOON FORECAST PACKAGE. ALTHOUGH PATCHY FROST IS POSSIBLE
WITH TEMPERATURES IN THE MID 30S...THE POTENTIAL FOR FROST TONIGHT
APPEARS LOW FOR THESE FAR NORTHERN AREAS. FAILING TO DECOUPLE
ALONE MIGHT PREVENT IT...BUT ALSO LOOKING FOR A FAIRLY LARGE
DEWPOINT DEPRESSIONS. WOULD TEND TO LOOK FOR DEWPOINT DEPRESSIONS
LESS THAN 5 DEGREES IF FROST WAS GOING TO BE THREAT...AND
CURRENTLY NOT SEEING THAT IN THE GUIDANCE. SO...FORECAST FOR
TONIGHT WILL FEATURE MOSTLY CLEAR SKIES...A LIGHT NORTHEAST
BREEZE...AND LOW TEMPS BY SUNRISE RANGING FROM THE MID 30S FAR
NORTH...TO THE MID 40S IN THE I-4 CORRIDOR...AND MIDDLE TO UPPER
40S FURTHER SOUTH. NORMALLY WARMER SPOTS WITH A NORTHEAST BREEZE
OFF THE WATER...SUCH AS SOUTHERN PINELLAS COUNTY...AND THE ISLAND
OF CHARLOTTE HARBOR SHOULD HOLD IN THE LOWER 50S. WITH THE LIGHT
BREEZE...WIND CHILLS IN THE 30S ARE LIKELY TO REACH SOUTH BY
SUNRISE TO NORTHEAST HILLSBOROUGH COUNTY AND NORTHERN POLK COUNTY.
A PLEASANT...SEASONABLE...BUT BREEZY DAY IN STORE FOR YOUR TUESDAY.
HIGH PRESSURE REMAINS CENTERED WELL TO OUR NORTH KEEPING OUR WINDS
OUT OF THE NORTHEAST THROUGH THE DAY. CERTAINLY LOOKS AS THROUGH IT
WILL BE WINDY ON SOME OF THE AREA LAKES BY MID TO LATE MORNING...SO
BE AWARE OF THAT POTENTIAL. HIGH TEMPERATURES AGAIN STRUGGLING TO
REACH 60 UP TOWARD CHIEFLAND...BUT RECOVERING INTO THE UPPER 60S
THROUGH THE I-4 CORRIDOR...AND INTO THE LOWER 70S FOR PLACES LIKE
SARASOTA/PUNTA GORDA/FORT MYERS. LOOK FOR A MIX OF SUN AND SHALLOW
CU FOR THE MAJORITY OF THE DAYLIGHT HOURS.
HAVE A GREAT REST OF YOUR MONDAY EVERYONE!
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL FOR THE DURATION OF THE TAF PERIOD
ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA. BREEZY NORTH TO
NORTHEAST WINDS WILL ALSO PERSIST. PREVAILING VFR CONDITIONS ARE
EXPECTED TO CONTINUE THROUGH THE DAYLIGHT HOURS OF TUESDAY.
&&
.MARINE...
SMALL CRAFT ADVISORY IN EFFECT FOR THE WATERS OF TAMPA BAY AND
CHARLOTTE HARBOR TONIGHT INTO TUESDAY MORNING. SMALL CRAFT
ADVISORY IN EFFECT OUT TO 60NM FROM BONITA SPRINGS TO THE SUWANNEE
RIVER TONIGHT THROUGH LATE TUESDAY NIGHT.
A STRONG AREA OF HIGH PRESSURE WILL BE BUILDING TO THE NORTH OF
THE AREA THE REMAINDER OF TODAY. ALREADY ELEVATED NORTH WINDS
WILL BE INCREASING TO ADVISORY LEVELS THIS EVENING AS THEY TURN TO
THE NORTHEAST. WINDS AND SEAS WILL LIKELY BE NEAR OR OVER ADVISORY
LEVELS TONIGHT THROUGH TUESDAY NIGHT. THE GRADIENT IS EXPECTED TO
RELAX DURING THE SECOND HALF OF THE WEEK ALLOWING WINDS AND SEAS
TO SUBSIDE.
&&
.FIRE WEATHER...
A COOL AND DRY NORTHERN FLOW WILL RESULT IN THE POTENTIAL FOR A
COUPLE HOURS OF SUB 35 PERCENT RELATIVE HUMIDITY AWAY FROM THE
IMMEDIATE COAST TODAY. NO RED FLAG CONDITIONS ARE ANTICIPATED AS
ERC VALUES REMAIN LOW AND 20 FOOT WINDS REMAIN GENERALLY BELOW 15
KNOTS. LOW LEVEL MOISTURE WILL BEGIN TO RETURN TO THE REGION BY
TUESDAY...PREVENTING CRITICAL LEVELS OF RELATIVE HUMIDITY THROUGH
THE MIDDLE OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 67 46 68 54 / 0 0 0 10
FMY 69 48 72 57 / 10 0 10 30
GIF 65 46 67 54 / 0 0 10 30
SRQ 67 47 70 56 / 0 0 10 20
BKV 64 40 66 50 / 0 0 0 10
SPG 65 51 67 57 / 0 0 0 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR COASTAL WATERS FROM BONITA BEACH TO
ENGLEWOOD FL OUT 20 NM-COASTAL WATERS FROM ENGLEWOOD
TO TARPON SPRINGS FL OUT 20 NM-COASTAL WATERS FROM
TARPON SPRINGS TO SUWANNEE RIVER FL OUT 20 NM-WATERS
FROM BONITA BEACH TO ENGLEWOOD FL OUT 20 TO 60 NM-
WATERS FROM ENGLEWOOD TO TARPON SPRINGS FL OUT 20 TO
60 NM-WATERS FROM TARPON SPRINGS TO SUWANNEE RIVER FL
OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
TUESDAY FOR CHARLOTTE HARBOR AND PINE ISLAND SOUND-
TAMPA BAY WATERS.
&&
$$
UPDATE/AVIATION/MARINE/FIRE WX...MROCZKA
DECISION SUPPORT...CARLISLE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1002 AM CST MON JAN 4 2016
.UPDATE...
842 AM CST
LAKE EFFECT SNOW SHOWERS CONTINUE TO MOVE SOUTH AND SOUTHWEST INTO
NE IL AND NW IN THIS MORNING. MORE INTENSE ECHOES PERIODICALLY
DEVELOP BUT THE BAND HAS PRIMARILY BEEN MADE UP OF LESS INTENSE
REFLECTIVITY. UPSTREAM OBS SHOW SPORADIC VISIBILITY OF 1/2 TO 1
MILE BUT WEBCAMS SHOW LITTLE MORE THAN A DUSTING OF ACCUMULATION
IN MOST AREAS SUGGESTING THE VSBY DROP/PEAK SNOW INTENSITY IS
BRIEF. MORE INTENSE ECHOES ARE STILL OFFSHORE AND WILL BE TRACKING
SOUTHWARD INTO CENTRAL/SOUTHERN COOK AND LAKE AND PORTER COUNTIES
IN INDIANA BETWEEN NOW AND ABOUT 930/10 AM CST. THE CONVERGENCE
MAY BECOME SOMEWHAT STATIONARY OVER NE IL FOR A TIME BUT SNOW
INTENSITY WILL LIKELY EASE. THE WINDOW FOR ACCUMULATION WILL BE
THIS MORNING AND WIND DOWN BY MIDDAY OR SO THOUGH SOME LIGHT SNOW
SHOWERS MAY CONTINUE WITH THE FLOW OFF THE LAKE BUT WITH DECREASED
CONVERGENCE...LESS ORGANIZATION AND LESS FAVORABLE LAKE EFFECT
PARAMETERS TAKING OVER. OVERALL ACCUMS OF A DUSTING TO A FEW
TENTHS IS MOST LIKELY WITH ISOLATED AMOUNTS OF CLOSER TO AN INCH
STILL POSSIBLE...ESPECIALLY GIVEN THAT MORE INTENSE ECHOES ARE
STILL OFFSHORE.
MDB
&&
.SHORT TERM...
327 AM CST
THROUGH TUESDAY...
THE LAKE EFFECT SNOW IN THE FORECAST AREA TODAY STILL LOOKS LIKE
A GOOD POSSIBILITY AND THE MAIN FORECAST CHANGE WAS TO REFINE AND
HONE IN ON THE TIMING AND IMPACTS. REGARDING TIMING...THROUGH A
COMBINATION OF OBSERVATIONAL TRENDS AND HIGH-RESOLUTION GUIDANCE
HAVE SPED UP THE START TIME OF THE SNOW SHOWERS IN FAR NORTHEAST
ILLINOIS AND FAR NORTHWEST INDIANA AND ALSO LIMITED THE SNOW
SHOWER DURATION FROM PREVIOUS FORECAST. THIS DID RESULT IN LESS
AVERAGE FORECAST SNOWFALL TOTALS...THOUGH AS ALWAYS WITH LAKE
EFFECT SNOW SHOWERS THERE CAN BE A HIGH AMOUNT OF VARIABILITY OVER
SPACE. AROUND AN INCH IS FORECAST IN LAKE ADJACENT COUNTIES WITH
THE LIKELY POSSIBILITY OF LESS IN SOME SPOTS AND A LITTLE MORE IN
OTHERS. A DUSTING IS FORECAST IN THE SECOND TIER COUNTIES
SURROUNDING THE SOUTHERN PART OF THE LAKE.
THE UPPER AIR PATTERN EARLY THIS MORNING CONTINUES TO BE ONE OF
REINFORCING COLD AIR ALOFT OVER THE GREAT LAKES...WITH A 130KT DUE
SOUTHWARD POINTING JET ENTERING THE REGION. THE 850MB TEMPERATURES
ARE AROUND -13C OFFERING AROUND AN ESTIMATED 15C DIFFERENCE
BETWEEN THE 850MB AND LAKE SURFACE TEMPERATURES. THIS HAS
RESULTED IN BROAD SNOW SHOWERS ORIENTED INTO LOWER MICHIGAN AND
MAINLY LA PORTE COUNTY INDIANA THUS FAR.
AT THE SURFACE...A COLD FRONT IS ORIENTED NORTHWEST-TO-SOUTHEAST
OVER THE CENTRAL PART OF THE LAKE AHEAD OF AN ARCTIC HIGH THAT
WILL MODIFY AS IT CREEPS SOUTHWARD TODAY. PRESSURE RISES OF
4-5MB/3HR ARE PUSHING THE FRONT SOUTHWARD WITH MORE PRONOUNCED DRY
AIR BEHIND IT. ALONG THE BOUNDARY A LAKE-INDUCED CIRCULATION IS
PRESENT ON RADAR MOSAIC AND WIND STREAMLINE ANALYSIS OFF THE SHORE
OF LUDINGTON MICHIGAN. THIS FEATURE SHOULD CONTINUE SOUTHWARD DOWN
THE LAKE WITH THE SYNOPTIC BOUNDARY EARLY THIS MORNING ASSISTING
IS LOCALIZED CONVERGENCE AND LIKELY BRIEFLY ENHANCING SNOWFALL
RATES ON THE WESTERN FLANK WHICH RIGHT NOW IS EXPECTED TO CLIP FAR
NORTHEAST ILLINOIS AND INTO NORTHWEST INDIANA. A MORE PRONOUNCED
BAND OR COUPLE BANDS ARE STARTING TO DEVELOP UPSTREAM WITH THIS
AND SHOULD CONTINUE TO BETTER DEVELOP GIVEN THE FORECAST
CONVERGENCE AND SUGGESTED SOLUTIONS BY CONVECTIVE ALLOWING
GUIDANCE. LAKE-INDUCED CAPE AT THE LEADING EDGE OF THIS LOOKS TO
BE 100-200 J/KG WITH AN EQUILIBRIUM LEVEL AROUND 8000 FT PER
MODIFIED RAP AND NAM SOUNDINGS. THIS WILL LIKELY SUPPORT A BURST
OF MODERATE TO BRIEFLY HEAVY SNOW SHOWERS FOR SOME LOCATIONS
WHERE THIS COMES INLAND...ARRIVING BETWEEN 9-11 AM CURRENTLY
LOOKS LIKE THE BEST FORECAST TIME. HOWEVER THIS BAND/S/ LOOKS TO
HAVE A SNAKE-LIKE SHAPE AND BE FAIRLY PROGRESSIVE...THUS LIMITING
RESIDENCE TIME IN ANY ONE LOCATION AS THE FRONT AND MESOLOW PUSH
SOUTHWARD. SO WHILE A QUICK INCH OR A LITTLE OVER MAY OCCUR FOR
SOME...AMOUNTS AFTER THAT FIRST HOUR OR SO LOOK TO BE LESS. IT
ALSO LOOKS LIKE THE SNOW SHOULD SQUEEZE IN JUST BEHIND THE MORNING
COMMUTE...HELPING TO MINIMIZE IMPACTS SOME. WILL STILL LIKELY
ISSUE AN SPS JUST FOR THE POTENTIAL FOR A RAPID CHANGE IN
VISIBILITY EVEN IF BRIEF.
GOING INTO THE EARLY-MID AFTERNOON BEHIND THE FRONT...LESS
ORGANIZED SNOW SHOWERS OR FLURRIES WILL REMAIN WITH LIGHT
ADDITIONAL ACCUMULATION AS EQUILIBRIUM HEIGHTS LOWER ON A
STRENGTHENING SUBSIDENCE INVERSION. THE EXCEPTION MAY BE LAKE
COUNTY ILLINOIS AND NORTHERN COOK WHERE SOME CONVERGENCE WITH A
LONG FETCH IS FORECAST...SO RESIDENCE TIME OF LIGHT SNOW COULD
HELP TO YIELD AN ADDITIONAL HALF INCH OR MORE...BUT EVEN THAT
LOOKS TO WEAKEN THROUGH THE AFTERNOON AS DRY ADVECTION
STRENGTHENS.
HIGHS TODAY ARE FORECAST TO PEAK IN THE UPPER 20S IN MOST
LOCATIONS WITH GRADUALLY MORE SUNSHINE FORECAST IN THE AFTERNOON
AWAY FROM LAKE INDUCED CLOUDS. TONIGHT SHOULD SEE THE SKY CLEAR
IN MOST IF NOT ALL LOCATIONS. HAVE GONE TOWARD COOLER GFS-BASED
MOS GUIDANCE WITH WINDS DROPPING OFF AND SOME LOCATIONS HAVING A
TAD BIT OF FRESH SNOW. SOME UPPER SINGLE DIGITS ARE PROBABLY A
DECENT BET IN FAVORED COOLER LOCATIONS.
MTF
&&
.LONG TERM...
327 AM CST
TUESDAY NIGHT THROUGH SUNDAY...
A SLOW MODERATION CONTINUES TO BE FORECAST MIDWEEK WITH A
DAMPENING UPPER RIDGE SHIFTING EAST OVER THE AREA AND SOUTHWEST
850-1000MB FLOW DEVELOPING UNDERNEATH. THE BLOCKED PATTERN IN THE
WESTERN CONUS IS FORECAST TO BREAK DOWN WITH A STRONG WEST-TO-EAST
PACIFIC JET EXPANDING INTO SOUTHERN CALIFORNIA. A LEADING SHORT
WAVE EJECTING FROM THIS IS EXPECTED TO MOISTEN THE LOW-LEVEL FLOW
INTO THE MISSISSIPPI VALLEY REGION AND THAT STILL IS FORECAST
DURING LATER WEDNESDAY NIGHT INTO THURSDAY. WOULD NOT BE
SURPRISED TO SEE THIS SLOW DOWN A TAD. TEMPERATURES...
THICKNESSES...AND FORECAST PROFILES IN GENERAL STILL LOOK
SUPPORTIVE OF POTENTIALLY LIGHT SNOW OR A WINTRY MIX AT THE
LEADING EDGE OF SATURATED ASCENT.
THE MORE PRONOUNCED LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP
OVER THE CENTRAL PLAINS THURSDAY NIGHT INTO FRIDAY YIELDING DEEPER
MOISTURE TRANSPORT AND MORE WIDESPREAD LIFT WITHIN UPPER
DIFFLUENCE...ALL SUPPORTING LIKELY RAIN AT THIS JUNCTURE. THE LIFT
AND ESPECIALLY MOISTURE IS PRESENTLY NOT FORECAST TO THE MAGNITUDE
OF SEVERAL OF THE HEAVY RAIN DECEMBER SYSTEMS WE SAW...SO QPF IS
PRESENTLY BELOW AN INCH...BUT STILL ONE HALF TO THREE-QUARTERS OF
AN INCH OF RAIN IN JANUARY ON SATURATED GROUND IS NOTEWORTHY AND
SOMETHING WE WILL HAVE TO WATCH. THE 04.00 GFS CONTINUES JUST A
TAD FURTHER EAST AS DOES ITS ENSEMBLE COMPARED TO THE EC. IT WOULD
REQUIRE A FAIRLY LARGE SHIFT TO GET THE STRONGER COLD ADVECTION
WITH THIS SYSTEM GIVEN ITS SOMEWHAT BROAD NATURE...SO STILL FEEL
GOOD NOT MENTIONING ANY WINTERY PRECIPITATION CHANCES THURSDAY
NIGHT THROUGH FRIDAY NIGHT. EVEN DURING THE WEEKEND...WINTRY
PRECIPITATION PRESENTLY LOOKS TO BE LIGHT IF IT WERE TO
MATERIALIZE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* WINDS GRADUALLY VEERING TO NORTHEAST LATE MORNING OR EARLY
AFTERNOON WITH SPEEDS OF 10-12KT.
* LAKE EFFECT SNOW SHOWERS PERSISTING INTO THE AFTERNOON.
GENERALLY MVFR VIS LIKELY WITH PERIODS OF VIS 1SM POSSIBLE. OCNL
BRIEF PERIODS OF VIS LESS THAN 1SM POSSIBLE IN HEAVIER BANDS.
* MVFR CIGS LIKELY BY THE TIME OF SNOW ONSET AND CONTINUING INTO
EARLY EVENING.
KREIN/DEUBELBEISS
//DISCUSSION...UPDATED 12Z...
WINDS WILL GRADUALLY VEER FROM NWLY TO NELY AS HIGH
PRESSURE BUILDS ACROSS THE UPPER GREAT LAKES TO THE MIDDLE
MISSISSIPPI VALLEY. A WEAK PRESSURE GRADIENT OVER LAKE MICHIGAN
COMBINED WITH AN INFLUX OF COOLER AIR IS SETTING UP A PATTERN
CONDUCIVE TO LAKE EFFECT SNOW. LATEST RADAR IMAGERY ALREADY
INDICATES A WELL FORMED BAND OVER CENTRAL LAKE MICHIGAN WITH AN
APPARENT MESO-LOW APPEARANCE. THE HIGH RESOLUTION MODEL GUIDANCE
IS SUGGESTING THAT THE LAKE EFFECT PLUME COULD REACH THE CHICAGO
AREA TERMINALS A LITTLE FASTER THAN PREVIOUSLY NOTED...AND ALSO
INDICATING AN END TO THE MORE IMPACTING SNOWFALL A LITTLE EARLIER
AS WELL. IT IS LIKELY THAT THE HEAVIEST SNOW COULD IMPACT GYY MORE
SO THAN MDW/ORD/DPA...BUT STILL FEEL THAT THESE TERMINALS SHOULD
STILL SEE A PERIOD OF LAKE EFFECT SNOW DROPPING VISIBILITY TO
PREVAILING MVFR FOR A FEW HOURS OR SO. IT IS STILL POSSIBLE THAT
THERE WILL BE OCNL PERIODS OF LOWER VISIBILITY...1SM OR LESS...BUT
TIMING REMAINS UNCERTAIN AND WILL BE HIGHLY DEPENDENT ON THE
FINER SCALE EVOLUTION AND TRACK OF THE LAKE PLUME. IT IS LIKELY
THAT ORD/MDW COULD SEE AN INCH OR SO OF ACCUMULATION WITH DPA
POSSIBLY SEEING A LITTLE LESS AND GYY SEEING MORE.
THE LARGE SCALE HIGH PRESSURE IS EXPECTED TO SAG ACROSS NERN
IL/SRN LAKE MICHIGAN/NRN INDIANA BY LATE AFTERNOON...SHUTTING OFF
THE LAKE EFFECT SNOW POTENTIAL AND SHIFTING WINDS TO SOUTHEASTERLY
BY EARLY EVENING AND SOUTHERLY OVERNIGHT. MVFR CIGS DEVELOPING
WITH THE LAKE EFFECT SNOW SHOULD CONTINUE INTO THE EARLY
EVENING...BUT AS THE HIGH PRESSURE BUILDS ACROSS THE
REGION...SKIES SHOULD QUICKLY SCATTER OUT AND BECM MOSTLY CLEAR
OVERNIGHT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH CONFIDENCE IN TIMING/DURATION OF LAKE EFFECT SNOW.
LOW CONFIDENCE IN TIMING AND DURATION OF VIS DROPPING TO 1SM OR
LESS IN HEAVIER BANDS OF SNOW.
* MEDIUM CONFIDENCE IN WIND AND CEILING TRENDS THROUGH THE
PERIOD.
KREIN/DEUBELBEISS
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR/WX NIL.
WEDNESDAY...VFR/WX NIL.
THURSDAY...WINTRY MIX OF PCPN EARLY CHANGING OVER TO RAIN IN THE
AFTERNOON AND CONTINUING THROUGH THE NIGHT. MVFR CIG/VIS
LIKELY...IFR CONDITIONS POSSIBLE.
FRIDAY...RAIN LIKELY THROUGH THE DAY AND CONTINUING OVERNIGHT.
MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SATURDAY...CHANCE OF RAIN THROUGH THE DAY...CHANGING OVER TO SNOW
OVERNIGHT. MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF LINGERING LIGHT SNOW MORNING. MVFR CIG/VIS
POSSIBLE MORNING. OTRW...VFR/WX NIL.
KREIN
&&
.MARINE...
345 AM CST
MAIN MARINE CONCERN IN THE NEAR TERM IS A PERIOD OF NORTHWEST TO
NORTHEAST WINDS OF 20-25 KT WITH OCCASIONAL GUSTS TO 30
KT PRODUCING HAZARDOUS CONDITIONS FOR SMALL CRAFT ALONG BOTH THE
ILLINOIS AND INDIANA NEARSHORE WATERS THROUGH LATE THIS AFTERNOON
OR EARLY EVENING. WINDS WILL DIMINISH FAIRLY QUICKLY THIS EVENING
AS HIGH PRESSURE MOVES ACROSS THE LAKE THIS EVENING AND OVERNIGHT
TONIGHT.
WINDS WILL TURN TO THE SOUTH LATE TODAY NIGHT AS THE HIGH MOVES
OFF TO THE EAST... WITH THESE SOUTH WINDS INCREASING AS THE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A FAIRLY DEEP
AREA OF LOW PRESSURE TRACKING ACROSS HUDSON BAY. WINDS WILL RAMP
UP QUICKLY TO 30 KTS AND BECOME SOUTHWESTERLY ON NORTHERN LAKE
MICHIGAN LATE TONIGHT. A PERIOD OF SOUTHWEST GALES IS LIKELY
ACROSS THE NORTH HALF OF THE LAKE TUESDAY AND TUESDAY NIGHT WHEN
THE PRESSURE GRADIENT IS THE STRONGEST. THE GRADIENT WILL THEN
RELAX A BIT BY EARLY WEDNESDAY...AND WILL EVENTUALLY BACK TO THE
EAST THURSDAY NIGHT AS ANOTHER LOW LIFTS NORTHEAST FROM THE
SOUTHERN PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM MONDAY.
&&
$$
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
NWS CHICAGO/ROMEOVILLE IL
843 AM CST MON JAN 4 2016
.UPDATE...
842 AM CST
LAKE EFFECT SNOW SHOWERS CONTINUE TO MOVE SOUTH AND SOUTHWEST INTO
NE IL AND NW IN THIS MORNING. MORE INTENSE ECHOES PERIODICALLY
DEVELOP BUT THE BAND HAS PRIMARILY BEEN MADE UP OF LESS INTENSE
REFLECTIVITY. UPSTREAM OBS SHOW SPORADIC VISIBILITY OF 1/2 TO 1
MILE BUT WEBCAMS SHOW LITTLE MORE THAN A DUSTING OF ACCUMULATION
IN MOST AREAS SUGGESTING THE VSBY DROP/PEAK SNOW INTENSITY IS
BRIEF. MORE INTENSE ECHOES ARE STILL OFFSHORE AND WILL BE TRACKING
SOUTHWARD INTO CENTRAL/SOUTHERN COOK AND LAKE AND PORTER COUNTIES
IN INDIANA BETWEEN NOW AND ABOUT 930/10 AM CST. THE CONVERGENCE
MAY BECOME SOMEWHAT STATIONARY OVER NE IL FOR A TIME BUT SNOW
INTENSITY WILL LIKELY EASE. THE WINDOW FOR ACCUMULATION WILL BE
THIS MORNING AND WIND DOWN BY MIDDAY OR SO THOUGH SOME LIGHT SNOW
SHOWERS MAY CONTINUE WITH THE FLOW OFF THE LAKE BUT WITH DECREASED
CONVERGENCE...LESS ORGANIZATION AND LESS FAVORABLE LAKE EFFECT
PARAMETERS TAKING OVER. OVERALL ACCUMS OF A DUSTING TO A FEW
TENTHS IS MOST LIKELY WITH ISOLATED AMOUNTS OF CLOSER TO AN INCH
STILL POSSIBLE...ESPECIALLY GIVEN THAT MORE INTENSE ECHOES ARE
STILL OFFSHORE.
MDB
&&
.SHORT TERM...
327 AM CST
THROUGH TUESDAY...
THE LAKE EFFECT SNOW IN THE FORECAST AREA TODAY STILL LOOKS LIKE
A GOOD POSSIBILITY AND THE MAIN FORECAST CHANGE WAS TO REFINE AND
HONE IN ON THE TIMING AND IMPACTS. REGARDING TIMING...THROUGH A
COMBINATION OF OBSERVATIONAL TRENDS AND HIGH-RESOLUTION GUIDANCE
HAVE SPED UP THE START TIME OF THE SNOW SHOWERS IN FAR NORTHEAST
ILLINOIS AND FAR NORTHWEST INDIANA AND ALSO LIMITED THE SNOW
SHOWER DURATION FROM PREVIOUS FORECAST. THIS DID RESULT IN LESS
AVERAGE FORECAST SNOWFALL TOTALS...THOUGH AS ALWAYS WITH LAKE
EFFECT SNOW SHOWERS THERE CAN BE A HIGH AMOUNT OF VARIABILITY OVER
SPACE. AROUND AN INCH IS FORECAST IN LAKE ADJACENT COUNTIES WITH
THE LIKELY POSSIBILITY OF LESS IN SOME SPOTS AND A LITTLE MORE IN
OTHERS. A DUSTING IS FORECAST IN THE SECOND TIER COUNTIES
SURROUNDING THE SOUTHERN PART OF THE LAKE.
THE UPPER AIR PATTERN EARLY THIS MORNING CONTINUES TO BE ONE OF
REINFORCING COLD AIR ALOFT OVER THE GREAT LAKES...WITH A 130KT DUE
SOUTHWARD POINTING JET ENTERING THE REGION. THE 850MB TEMPERATURES
ARE AROUND -13C OFFERING AROUND AN ESTIMATED 15C DIFFERENCE
BETWEEN THE 850MB AND LAKE SURFACE TEMPERATURES. THIS HAS
RESULTED IN BROAD SNOW SHOWERS ORIENTED INTO LOWER MICHIGAN AND
MAINLY LA PORTE COUNTY INDIANA THUS FAR.
AT THE SURFACE...A COLD FRONT IS ORIENTED NORTHWEST-TO-SOUTHEAST
OVER THE CENTRAL PART OF THE LAKE AHEAD OF AN ARCTIC HIGH THAT
WILL MODIFY AS IT CREEPS SOUTHWARD TODAY. PRESSURE RISES OF
4-5MB/3HR ARE PUSHING THE FRONT SOUTHWARD WITH MORE PRONOUNCED DRY
AIR BEHIND IT. ALONG THE BOUNDARY A LAKE-INDUCED CIRCULATION IS
PRESENT ON RADAR MOSAIC AND WIND STREAMLINE ANALYSIS OFF THE SHORE
OF LUDINGTON MICHIGAN. THIS FEATURE SHOULD CONTINUE SOUTHWARD DOWN
THE LAKE WITH THE SYNOPTIC BOUNDARY EARLY THIS MORNING ASSISTING
IS LOCALIZED CONVERGENCE AND LIKELY BRIEFLY ENHANCING SNOWFALL
RATES ON THE WESTERN FLANK WHICH RIGHT NOW IS EXPECTED TO CLIP FAR
NORTHEAST ILLINOIS AND INTO NORTHWEST INDIANA. A MORE PRONOUNCED
BAND OR COUPLE BANDS ARE STARTING TO DEVELOP UPSTREAM WITH THIS
AND SHOULD CONTINUE TO BETTER DEVELOP GIVEN THE FORECAST
CONVERGENCE AND SUGGESTED SOLUTIONS BY CONVECTIVE ALLOWING
GUIDANCE. LAKE-INDUCED CAPE AT THE LEADING EDGE OF THIS LOOKS TO
BE 100-200 J/KG WITH AN EQUILIBRIUM LEVEL AROUND 8000 FT PER
MODIFIED RAP AND NAM SOUNDINGS. THIS WILL LIKELY SUPPORT A BURST
OF MODERATE TO BRIEFLY HEAVY SNOW SHOWERS FOR SOME LOCATIONS
WHERE THIS COMES INLAND...ARRIVING BETWEEN 9-11 AM CURRENTLY
LOOKS LIKE THE BEST FORECAST TIME. HOWEVER THIS BAND/S/ LOOKS TO
HAVE A SNAKE-LIKE SHAPE AND BE FAIRLY PROGRESSIVE...THUS LIMITING
RESIDENCE TIME IN ANY ONE LOCATION AS THE FRONT AND MESOLOW PUSH
SOUTHWARD. SO WHILE A QUICK INCH OR A LITTLE OVER MAY OCCUR FOR
SOME...AMOUNTS AFTER THAT FIRST HOUR OR SO LOOK TO BE LESS. IT
ALSO LOOKS LIKE THE SNOW SHOULD SQUEEZE IN JUST BEHIND THE MORNING
COMMUTE...HELPING TO MINIMIZE IMPACTS SOME. WILL STILL LIKELY
ISSUE AN SPS JUST FOR THE POTENTIAL FOR A RAPID CHANGE IN
VISIBILITY EVEN IF BRIEF.
GOING INTO THE EARLY-MID AFTERNOON BEHIND THE FRONT...LESS
ORGANIZED SNOW SHOWERS OR FLURRIES WILL REMAIN WITH LIGHT
ADDITIONAL ACCUMULATION AS EQUILIBRIUM HEIGHTS LOWER ON A
STRENGTHENING SUBSIDENCE INVERSION. THE EXCEPTION MAY BE LAKE
COUNTY ILLINOIS AND NORTHERN COOK WHERE SOME CONVERGENCE WITH A
LONG FETCH IS FORECAST...SO RESIDENCE TIME OF LIGHT SNOW COULD
HELP TO YIELD AN ADDITIONAL HALF INCH OR MORE...BUT EVEN THAT
LOOKS TO WEAKEN THROUGH THE AFTERNOON AS DRY ADVECTION
STRENGTHENS.
HIGHS TODAY ARE FORECAST TO PEAK IN THE UPPER 20S IN MOST
LOCATIONS WITH GRADUALLY MORE SUNSHINE FORECAST IN THE AFTERNOON
AWAY FROM LAKE INDUCED CLOUDS. TONIGHT SHOULD SEE THE SKY CLEAR
IN MOST IF NOT ALL LOCATIONS. HAVE GONE TOWARD COOLER GFS-BASED
MOS GUIDANCE WITH WINDS DROPPING OFF AND SOME LOCATIONS HAVING A
TAD BIT OF FRESH SNOW. SOME UPPER SINGLE DIGITS ARE PROBABLY A
DECENT BET IN FAVORED COOLER LOCATIONS.
MTF
&&
.LONG TERM...
327 AM CST
TUESDAY NIGHT THROUGH SUNDAY...
A SLOW MODERATION CONTINUES TO BE FORECAST MIDWEEK WITH A
DAMPENING UPPER RIDGE SHIFTING EAST OVER THE AREA AND SOUTHWEST
850-1000MB FLOW DEVELOPING UNDERNEATH. THE BLOCKED PATTERN IN THE
WESTERN CONUS IS FORECAST TO BREAK DOWN WITH A STRONG WEST-TO-EAST
PACIFIC JET EXPANDING INTO SOUTHERN CALIFORNIA. A LEADING SHORT
WAVE EJECTING FROM THIS IS EXPECTED TO MOISTEN THE LOW-LEVEL FLOW
INTO THE MISSISSIPPI VALLEY REGION AND THAT STILL IS FORECAST
DURING LATER WEDNESDAY NIGHT INTO THURSDAY. WOULD NOT BE
SURPRISED TO SEE THIS SLOW DOWN A TAD. TEMPERATURES...
THICKNESSES...AND FORECAST PROFILES IN GENERAL STILL LOOK
SUPPORTIVE OF POTENTIALLY LIGHT SNOW OR A WINTRY MIX AT THE
LEADING EDGE OF SATURATED ASCENT.
THE MORE PRONOUNCED LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP
OVER THE CENTRAL PLAINS THURSDAY NIGHT INTO FRIDAY YIELDING DEEPER
MOISTURE TRANSPORT AND MORE WIDESPREAD LIFT WITHIN UPPER
DIFFLUENCE...ALL SUPPORTING LIKELY RAIN AT THIS JUNCTURE. THE LIFT
AND ESPECIALLY MOISTURE IS PRESENTLY NOT FORECAST TO THE MAGNITUDE
OF SEVERAL OF THE HEAVY RAIN DECEMBER SYSTEMS WE SAW...SO QPF IS
PRESENTLY BELOW AN INCH...BUT STILL ONE HALF TO THREE-QUARTERS OF
AN INCH OF RAIN IN JANUARY ON SATURATED GROUND IS NOTEWORTHY AND
SOMETHING WE WILL HAVE TO WATCH. THE 04.00 GFS CONTINUES JUST A
TAD FURTHER EAST AS DOES ITS ENSEMBLE COMPARED TO THE EC. IT WOULD
REQUIRE A FAIRLY LARGE SHIFT TO GET THE STRONGER COLD ADVECTION
WITH THIS SYSTEM GIVEN ITS SOMEWHAT BROAD NATURE...SO STILL FEEL
GOOD NOT MENTIONING ANY WINTERY PRECIPITATION CHANCES THURSDAY
NIGHT THROUGH FRIDAY NIGHT. EVEN DURING THE WEEKEND...WINTRY
PRECIPITATION PRESENTLY LOOKS TO BE LIGHT IF IT WERE TO
MATERIALIZE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* WINDS SHIFTING TO THE NORTHEAST LATE MORNING OR EARLY AFTERNOON WITH
SPEEDS OF 10-12KT.
* LAKE EFFECT SNOW SHOWERS BEGINNING LATE MORNING AND PERSISTING
INTO THE AFTERNOON. GENERALLY MVFR VIS LIKELY WITH PERIODS OF
VIS 1SM POSSIBLE. OCNL BRIEF PERIODS OF VIS LESS THAN 1SM
POSSIBLE IN HEAVIER BANDS.
* MVFR CIGS LIKELY BY THE TIME OF SNOW ONSET AND CONTINUING INTO
EARLY EVENING.
KREIN/DEUBELBEISS
//DISCUSSION...UPDATED 12Z...
WINDS WILL GRADUALLY VEER FROM NWLY TO NELY AS HIGH
PRESSURE BUILDS ACROSS THE UPPER GREAT LAKES TO THE MIDDLE
MISSISSIPPI VALLEY. A WEAK PRESSURE GRADIENT OVER LAKE MICHIGAN
COMBINED WITH AN INFLUX OF COOLER AIR IS SETTING UP A PATTERN
CONDUCIVE TO LAKE EFFECT SNOW. LATEST RADAR IMAGERY ALREADY
INDICATES A WELL FORMED BAND OVER CENTRAL LAKE MICHIGAN WITH AN
APPARENT MESO-LOW APPEARANCE. THE HIGH RESOLUTION MODEL GUIDANCE
IS SUGGESTING THAT THE LAKE EFFECT PLUME COULD REACH THE CHICAGO
AREA TERMINALS A LITTLE FASTER THAN PREVIOUSLY NOTED...AND ALSO
INDICATING AN END TO THE MORE IMPACTING SNOWFALL A LITTLE EARLIER
AS WELL. IT IS LIKELY THAT THE HEAVIEST SNOW COULD IMPACT GYY MORE
SO THAN MDW/ORD/DPA...BUT STILL FEEL THAT THESE TERMINALS SHOULD
STILL SEE A PERIOD OF LAKE EFFECT SNOW DROPPING VISIBILITY TO
PREVAILING MVFR FOR A FEW HOURS OR SO. IT IS STILL POSSIBLE THAT
THERE WILL BE OCNL PERIODS OF LOWER VISIBILITY...1SM OR LESS...BUT
TIMING REMAINS UNCERTAIN AND WILL BE HIGHLY DEPENDENT ON THE
FINER SCALE EVOLUTION AND TRACK OF THE LAKE PLUME. IT IS LIKELY
THAT ORD/MDW COULD SEE AN INCH OR SO OF ACCUMULATION WITH DPA
POSSIBLY SEEING A LITTLE LESS AND GYY SEEING MORE.
THE LARGE SCALE HIGH PRESSURE IS EXPECTED TO SAG ACROSS NERN
IL/SRN LAKE MICHIGAN/NRN INDIANA BY LATE AFTERNOON...SHUTTING OFF
THE LAKE EFFECT SNOW POTENTIAL AND SHIFTING WINDS TO SOUTHEASTERLY
BY EARLY EVENING AND SOUTHERLY OVERNIGHT. MVFR CIGS DEVELOPING
WITH THE LAKE EFFECT SNOW SHOULD CONTINUE INTO THE EARLY
EVENING...BUT AS THE HIGH PRESSURE BUILDS ACROSS THE
REGION...SKIES SHOULD QUICKLY SCATTER OUT AND BECM MOSTLY CLEAR
OVERNIGHT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN TIMING/DURATION OF LAKE EFFECT SNOW.
LOW CONFIDENCE IN TIMING AND DURATION OF VIS DROPPING TO 1SM OR
LESS IN HEAVIER BANDS OF SNOW.
* MEDIUM-HIGH CONFIDENCE IN WIND AND CEILING TRENDS THROUGH THE
PERIOD.
KREIN/DEUBELBEISS
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR/WX NIL.
WEDNESDAY...VFR/WX NIL.
THURSDAY...WINTRY MIX OF PCPN EARLY CHANGING OVER TO RAIN IN THE
AFTERNOON AND CONTINUING THROUGH THE NIGHT. MVFR CIG/VIS
LIKELY...IFR CONDITIONS POSSIBLE.
FRIDAY...RAIN LIKELY THROUGH THE DAY AND CONTINUING OVERNIGHT.
MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SATURDAY...CHANCE OF RAIN THROUGH THE DAY...CHANGING OVER TO SNOW
OVERNIGHT. MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF LINGERING LIGHT SNOW MORNING. MVFR CIG/VIS
POSSIBLE MORNING. OTRW...VFR/WX NIL.
KREIN
&&
.MARINE...
345 AM CST
MAIN MARINE CONCERN IN THE NEAR TERM IS A PERIOD OF NORTHWEST TO
NORTHEAST WINDS OF 20-25 KT WITH OCCASIONAL GUSTS TO 30
KT PRODUCING HAZARDOUS CONDITIONS FOR SMALL CRAFT ALONG BOTH THE
ILLINOIS AND INDIANA NEARSHORE WATERS THROUGH LATE THIS AFTERNOON
OR EARLY EVENING. WINDS WILL DIMINISH FAIRLY QUICKLY THIS EVENING
AS HIGH PRESSURE MOVES ACROSS THE LAKE THIS EVENING AND OVERNIGHT
TONIGHT.
WINDS WILL TURN TO THE SOUTH LATE TODAY NIGHT AS THE HIGH MOVES
OFF TO THE EAST... WITH THESE SOUTH WINDS INCREASING AS THE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A FAIRLY DEEP
AREA OF LOW PRESSURE TRACKING ACROSS HUDSON BAY. WINDS WILL RAMP
UP QUICKLY TO 30 KTS AND BECOME SOUTHWESTERLY ON NORTHERN LAKE
MICHIGAN LATE TONIGHT. A PERIOD OF SOUTHWEST GALES IS LIKELY
ACROSS THE NORTH HALF OF THE LAKE TUESDAY AND TUESDAY NIGHT WHEN
THE PRESSURE GRADIENT IS THE STRONGEST. THE GRADIENT WILL THEN
RELAX A BIT BY EARLY WEDNESDAY...AND WILL EVENTUALLY BACK TO THE
EAST THURSDAY NIGHT AS ANOTHER LOW LIFTS NORTHEAST FROM THE
SOUTHERN PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM MONDAY.
&&
$$
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
NWS CHICAGO/ROMEOVILLE IL
814 AM CST MON JAN 4 2016
.SHORT TERM...
327 AM CST
THROUGH TUESDAY...
THE LAKE EFFECT SNOW IN THE FORECAST AREA TODAY STILL LOOKS LIKE
A GOOD POSSIBILITY AND THE MAIN FORECAST CHANGE WAS TO REFINE AND
HONE IN ON THE TIMING AND IMPACTS. REGARDING TIMING...THROUGH A
COMBINATION OF OBSERVATIONAL TRENDS AND HIGH-RESOLUTION GUIDANCE
HAVE SPED UP THE START TIME OF THE SNOW SHOWERS IN FAR NORTHEAST
ILLINOIS AND FAR NORTHWEST INDIANA AND ALSO LIMITED THE SNOW
SHOWER DURATION FROM PREVIOUS FORECAST. THIS DID RESULT IN LESS
AVERAGE FORECAST SNOWFALL TOTALS...THOUGH AS ALWAYS WITH LAKE
EFFECT SNOW SHOWERS THERE CAN BE A HIGH AMOUNT OF VARIABILITY OVER
SPACE. AROUND AN INCH IS FORECAST IN LAKE ADJACENT COUNTIES WITH
THE LIKELY POSSIBILITY OF LESS IN SOME SPOTS AND A LITTLE MORE IN
OTHERS. A DUSTING IS FORECAST IN THE SECOND TIER COUNTIES
SURROUNDING THE SOUTHERN PART OF THE LAKE.
THE UPPER AIR PATTERN EARLY THIS MORNING CONTINUES TO BE ONE OF
REINFORCING COLD AIR ALOFT OVER THE GREAT LAKES...WITH A 130KT DUE
SOUTHWARD POINTING JET ENTERING THE REGION. THE 850MB TEMPERATURES
ARE AROUND -13C OFFERING AROUND AN ESTIMATED 15C DIFFERENCE
BETWEEN THE 850MB AND LAKE SURFACE TEMPERATURES. THIS HAS
RESULTED IN BROAD SNOW SHOWERS ORIENTED INTO LOWER MICHIGAN AND
MAINLY LA PORTE COUNTY INDIANA THUS FAR.
AT THE SURFACE...A COLD FRONT IS ORIENTED NORTHWEST-TO-SOUTHEAST
OVER THE CENTRAL PART OF THE LAKE AHEAD OF AN ARCTIC HIGH THAT
WILL MODIFY AS IT CREEPS SOUTHWARD TODAY. PRESSURE RISES OF
4-5MB/3HR ARE PUSHING THE FRONT SOUTHWARD WITH MORE PRONOUNCED DRY
AIR BEHIND IT. ALONG THE BOUNDARY A LAKE-INDUCED CIRCULATION IS
PRESENT ON RADAR MOSAIC AND WIND STREAMLINE ANALYSIS OFF THE SHORE
OF LUDINGTON MICHIGAN. THIS FEATURE SHOULD CONTINUE SOUTHWARD DOWN
THE LAKE WITH THE SYNOPTIC BOUNDARY EARLY THIS MORNING ASSISTING
IS LOCALIZED CONVERGENCE AND LIKELY BRIEFLY ENHANCING SNOWFALL
RATES ON THE WESTERN FLANK WHICH RIGHT NOW IS EXPECTED TO CLIP FAR
NORTHEAST ILLINOIS AND INTO NORTHWEST INDIANA. A MORE PRONOUNCED
BAND OR COUPLE BANDS ARE STARTING TO DEVELOP UPSTREAM WITH THIS
AND SHOULD CONTINUE TO BETTER DEVELOP GIVEN THE FORECAST
CONVERGENCE AND SUGGESTED SOLUTIONS BY CONVECTIVE ALLOWING
GUIDANCE. LAKE-INDUCED CAPE AT THE LEADING EDGE OF THIS LOOKS TO
BE 100-200 J/KG WITH AN EQUILIBRIUM LEVEL AROUND 8000 FT PER
MODIFIED RAP AND NAM SOUNDINGS. THIS WILL LIKELY SUPPORT A BURST
OF MODERATE TO BRIEFLY HEAVY SNOW SHOWERS FOR SOME LOCATIONS
WHERE THIS COMES INLAND...ARRIVING BETWEEN 9-11 AM CURRENTLY
LOOKS LIKE THE BEST FORECAST TIME. HOWEVER THIS BAND/S/ LOOKS TO
HAVE A SNAKE-LIKE SHAPE AND BE FAIRLY PROGRESSIVE...THUS LIMITING
RESIDENCE TIME IN ANY ONE LOCATION AS THE FRONT AND MESOLOW PUSH
SOUTHWARD. SO WHILE A QUICK INCH OR A LITTLE OVER MAY OCCUR FOR
SOME...AMOUNTS AFTER THAT FIRST HOUR OR SO LOOK TO BE LESS. IT
ALSO LOOKS LIKE THE SNOW SHOULD SQUEEZE IN JUST BEHIND THE MORNING
COMMUTE...HELPING TO MINIMIZE IMPACTS SOME. WILL STILL LIKELY
ISSUE AN SPS JUST FOR THE POTENTIAL FOR A RAPID CHANGE IN
VISIBILITY EVEN IF BRIEF.
GOING INTO THE EARLY-MID AFTERNOON BEHIND THE FRONT...LESS
ORGANIZED SNOW SHOWERS OR FLURRIES WILL REMAIN WITH LIGHT
ADDITIONAL ACCUMULATION AS EQUILIBRIUM HEIGHTS LOWER ON A
STRENGTHENING SUBSIDENCE INVERSION. THE EXCEPTION MAY BE LAKE
COUNTY ILLINOIS AND NORTHERN COOK WHERE SOME CONVERGENCE WITH A
LONG FETCH IS FORECAST...SO RESIDENCE TIME OF LIGHT SNOW COULD
HELP TO YIELD AN ADDITIONAL HALF INCH OR MORE...BUT EVEN THAT
LOOKS TO WEAKEN THROUGH THE AFTERNOON AS DRY ADVECTION
STRENGTHENS.
HIGHS TODAY ARE FORECAST TO PEAK IN THE UPPER 20S IN MOST
LOCATIONS WITH GRADUALLY MORE SUNSHINE FORECAST IN THE AFTERNOON
AWAY FROM LAKE INDUCED CLOUDS. TONIGHT SHOULD SEE THE SKY CLEAR
IN MOST IF NOT ALL LOCATIONS. HAVE GONE TOWARD COOLER GFS-BASED
MOS GUIDANCE WITH WINDS DROPPING OFF AND SOME LOCATIONS HAVING A
TAD BIT OF FRESH SNOW. SOME UPPER SINGLE DIGITS ARE PROBABLY A
DECENT BET IN FAVORED COOLER LOCATIONS.
MTF
&&
.LONG TERM...
327 AM CST
TUESDAY NIGHT THROUGH SUNDAY...
A SLOW MODERATION CONTINUES TO BE FORECAST MIDWEEK WITH A
DAMPENING UPPER RIDGE SHIFTING EAST OVER THE AREA AND SOUTHWEST
850-1000MB FLOW DEVELOPING UNDERNEATH. THE BLOCKED PATTERN IN THE
WESTERN CONUS IS FORECAST TO BREAK DOWN WITH A STRONG WEST-TO-EAST
PACIFIC JET EXPANDING INTO SOUTHERN CALIFORNIA. A LEADING SHORT
WAVE EJECTING FROM THIS IS EXPECTED TO MOISTEN THE LOW-LEVEL FLOW
INTO THE MISSISSIPPI VALLEY REGION AND THAT STILL IS FORECAST
DURING LATER WEDNESDAY NIGHT INTO THURSDAY. WOULD NOT BE
SURPRISED TO SEE THIS SLOW DOWN A TAD. TEMPERATURES...
THICKNESSES...AND FORECAST PROFILES IN GENERAL STILL LOOK
SUPPORTIVE OF POTENTIALLY LIGHT SNOW OR A WINTRY MIX AT THE
LEADING EDGE OF SATURATED ASCENT.
THE MORE PRONOUNCED LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP
OVER THE CENTRAL PLAINS THURSDAY NIGHT INTO FRIDAY YIELDING DEEPER
MOISTURE TRANSPORT AND MORE WIDESPREAD LIFT WITHIN UPPER
DIFFLUENCE...ALL SUPPORTING LIKELY RAIN AT THIS JUNCTURE. THE LIFT
AND ESPECIALLY MOISTURE IS PRESENTLY NOT FORECAST TO THE MAGNITUDE
OF SEVERAL OF THE HEAVY RAIN DECEMBER SYSTEMS WE SAW...SO QPF IS
PRESENTLY BELOW AN INCH...BUT STILL ONE HALF TO THREE-QUARTERS OF
AN INCH OF RAIN IN JANUARY ON SATURATED GROUND IS NOTEWORTHY AND
SOMETHING WE WILL HAVE TO WATCH. THE 04.00 GFS CONTINUES JUST A
TAD FURTHER EAST AS DOES ITS ENSEMBLE COMPARED TO THE EC. IT WOULD
REQUIRE A FAIRLY LARGE SHIFT TO GET THE STRONGER COLD ADVECTION
WITH THIS SYSTEM GIVEN ITS SOMEWHAT BROAD NATURE...SO STILL FEEL
GOOD NOT MENTIONING ANY WINTERY PRECIPITATION CHANCES THURSDAY
NIGHT THROUGH FRIDAY NIGHT. EVEN DURING THE WEEKEND...WINTRY
PRECIPITATION PRESENTLY LOOKS TO BE LIGHT IF IT WERE TO
MATERIALIZE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* WINDS SHIFTING TO THE NORTHEAST LATE MORNING OR EARLY AFTERNOON WITH
SPEEDS OF 10-12KT.
* LAKE EFFECT SNOW SHOWERS BEGINNING LATE MORNING AND PERSISTING
INTO THE AFTERNOON. GENERALLY MVFR VIS LIKELY WITH PERIODS OF
VIS 1SM POSSIBLE. OCNL BRIEF PERIODS OF VIS LESS THAN 1SM
POSSIBLE IN HEAVIER BANDS.
* MVFR CIGS LIKELY BY THE TIME OF SNOW ONSET AND CONTINUING INTO
EARLY EVENING.
KREIN/DEUBELBEISS
//DISCUSSION...UPDATED 12Z...
WINDS WILL GRADUALLY VEER FROM NWLY TO NELY AS HIGH
PRESSURE BUILDS ACROSS THE UPPER GREAT LAKES TO THE MIDDLE
MISSISSIPPI VALLEY. A WEAK PRESSURE GRADIENT OVER LAKE MICHIGAN
COMBINED WITH AN INFLUX OF COOLER AIR IS SETTING UP A PATTERN
CONDUCIVE TO LAKE EFFECT SNOW. LATEST RADAR IMAGERY ALREADY
INDICATES A WELL FORMED BAND OVER CENTRAL LAKE MICHIGAN WITH AN
APPARENT MESO-LOW APPEARANCE. THE HIGH RESOLUTION MODEL GUIDANCE
IS SUGGESTING THAT THE LAKE EFFECT PLUME COULD REACH THE CHICAGO
AREA TERMINALS A LITTLE FASTER THAN PREVIOUSLY NOTED...AND ALSO
INDICATING AN END TO THE MORE IMPACTING SNOWFALL A LITTLE EARLIER
AS WELL. IT IS LIKELY THAT THE HEAVIEST SNOW COULD IMPACT GYY MORE
SO THAN MDW/ORD/DPA...BUT STILL FEEL THAT THESE TERMINALS SHOULD
STILL SEE A PERIOD OF LAKE EFFECT SNOW DROPPING VISIBILITY TO
PREVAILING MVFR FOR A FEW HOURS OR SO. IT IS STILL POSSIBLE THAT
THERE WILL BE OCNL PERIODS OF LOWER VISIBILITY...1SM OR LESS...BUT
TIMING REMAINS UNCERTAIN AND WILL BE HIGHLY DEPENDENT ON THE
FINER SCALE EVOLUTION AND TRACK OF THE LAKE PLUME. IT IS LIKELY
THAT ORD/MDW COULD SEE AN INCH OR SO OF ACCUMULATION WITH DPA
POSSIBLY SEEING A LITTLE LESS AND GYY SEEING MORE.
THE LARGE SCALE HIGH PRESSURE IS EXPECTED TO SAG ACROSS NERN
IL/SRN LAKE MICHIGAN/NRN INDIANA BY LATE AFTERNOON...SHUTTING OFF
THE LAKE EFFECT SNOW POTENTIAL AND SHIFTING WINDS TO SOUTHEASTERLY
BY EARLY EVENING AND SOUTHERLY OVERNIGHT. MVFR CIGS DEVELOPING
WITH THE LAKE EFFECT SNOW SHOULD CONTINUE INTO THE EARLY
EVENING...BUT AS THE HIGH PRESSURE BUILDS ACROSS THE
REGION...SKIES SHOULD QUICKLY SCATTER OUT AND BECM MOSTLY CLEAR
OVERNIGHT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN TIMING/DURATION OF LAKE EFFECT SNOW.
LOW CONFIDENCE IN TIMING AND DURATION OF VIS DROPPING TO 1SM OR
LESS IN HEAVIER BANDS OF SNOW.
* MEDIUM-HIGH CONFIDENCE IN WIND AND CEILING TRENDS THROUGH THE
PERIOD.
KREIN/DEUBELBEISS
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR/WX NIL.
WEDNESDAY...VFR/WX NIL.
THURSDAY...WINTRY MIX OF PCPN EARLY CHANGING OVER TO RAIN IN THE
AFTERNOON AND CONTINUING THROUGH THE NIGHT. MVFR CIG/VIS
LIKELY...IFR CONDITIONS POSSIBLE.
FRIDAY...RAIN LIKELY THROUGH THE DAY AND CONTINUING OVERNIGHT.
MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SATURDAY...CHANCE OF RAIN THROUGH THE DAY...CHANGING OVER TO SNOW
OVERNIGHT. MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF LINGERING LIGHT SNOW MORNING. MVFR CIG/VIS
POSSIBLE MORNING. OTRW...VFR/WX NIL.
KREIN
&&
.MARINE...
345 AM CST
MAIN MARINE CONCERN IN THE NEAR TERM IS A PERIOD OF NORTHWEST TO
NORTHEAST WINDS OF 20-25 KT WITH OCCASIONAL GUSTS TO 30
KT PRODUCING HAZARDOUS CONDITIONS FOR SMALL CRAFT ALONG BOTH THE
ILLINOIS AND INDIANA NEARSHORE WATERS THROUGH LATE THIS AFTERNOON
OR EARLY EVENING. WINDS WILL DIMINISH FAIRLY QUICKLY THIS EVENING
AS HIGH PRESSURE MOVES ACROSS THE LAKE THIS EVENING AND OVERNIGHT
TONIGHT.
WINDS WILL TURN TO THE SOUTH LATE TODAY NIGHT AS THE HIGH MOVES
OFF TO THE EAST... WITH THESE SOUTH WINDS INCREASING AS THE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A FAIRLY DEEP
AREA OF LOW PRESSURE TRACKING ACROSS HUDSON BAY. WINDS WILL RAMP
UP QUICKLY TO 30 KTS AND BECOME SOUTHWESTERLY ON NORTHERN LAKE
MICHIGAN LATE TONIGHT. A PERIOD OF SOUTHWEST GALES IS LIKELY
ACROSS THE NORTH HALF OF THE LAKE TUESDAY AND TUESDAY NIGHT WHEN
THE PRESSURE GRADIENT IS THE STRONGEST. THE GRADIENT WILL THEN
RELAX A BIT BY EARLY WEDNESDAY...AND WILL EVENTUALLY BACK TO THE
EAST THURSDAY NIGHT AS ANOTHER LOW LIFTS NORTHEAST FROM THE
SOUTHERN PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM MONDAY.
&&
$$
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
NWS CHICAGO/ROMEOVILLE IL
537 AM CST MON JAN 4 2016
.SHORT TERM...
327 AM CST
THROUGH TUESDAY...
THE LAKE EFFECT SNOW IN THE FORECAST AREA TODAY STILL LOOKS LIKE
A GOOD POSSIBILITY AND THE MAIN FORECAST CHANGE WAS TO REFINE AND
HONE IN ON THE TIMING AND IMPACTS. REGARDING TIMING...THROUGH A
COMBINATION OF OBSERVATIONAL TRENDS AND HIGH-RESOLUTION GUIDANCE
HAVE SPED UP THE START TIME OF THE SNOW SHOWERS IN FAR NORTHEAST
ILLINOIS AND FAR NORTHWEST INDIANA AND ALSO LIMITED THE SNOW
SHOWER DURATION FROM PREVIOUS FORECAST. THIS DID RESULT IN LESS
AVERAGE FORECAST SNOWFALL TOTALS...THOUGH AS ALWAYS WITH LAKE
EFFECT SNOW SHOWERS THERE CAN BE A HIGH AMOUNT OF VARIABILITY OVER
SPACE. AROUND AN INCH IS FORECAST IN LAKE ADJACENT COUNTIES WITH
THE LIKELY POSSIBILITY OF LESS IN SOME SPOTS AND A LITTLE MORE IN
OTHERS. A DUSTING IS FORECAST IN THE SECOND TIER COUNTIES
SURROUNDING THE SOUTHERN PART OF THE LAKE.
THE UPPER AIR PATTERN EARLY THIS MORNING CONTINUES TO BE ONE OF
REINFORCING COLD AIR ALOFT OVER THE GREAT LAKES...WITH A 130KT DUE
SOUTHWARD POINTING JET ENTERING THE REGION. THE 850MB TEMPERATURES
ARE AROUND -13C OFFERING AROUND AN ESTIMATED 15C DIFFERENCE
BETWEEN THE 850MB AND LAKE SURFACE TEMPERATURES. THIS HAS
RESULTED IN BROAD SNOW SHOWERS ORIENTED INTO LOWER MICHIGAN AND
MAINLY LA PORTE COUNTY INDIANA THUS FAR.
AT THE SURFACE...A COLD FRONT IS ORIENTED NORTHWEST-TO-SOUTHEAST
OVER THE CENTRAL PART OF THE LAKE AHEAD OF AN ARCTIC HIGH THAT
WILL MODIFY AS IT CREEPS SOUTHWARD TODAY. PRESSURE RISES OF
4-5MB/3HR ARE PUSHING THE FRONT SOUTHWARD WITH MORE PRONOUNCED DRY
AIR BEHIND IT. ALONG THE BOUNDARY A LAKE-INDUCED CIRCULATION IS
PRESENT ON RADAR MOSAIC AND WIND STREAMLINE ANALYSIS OFF THE SHORE
OF LUDINGTON MICHIGAN. THIS FEATURE SHOULD CONTINUE SOUTHWARD DOWN
THE LAKE WITH THE SYNOPTIC BOUNDARY EARLY THIS MORNING ASSISTING
IS LOCALIZED CONVERGENCE AND LIKELY BRIEFLY ENHANCING SNOWFALL
RATES ON THE WESTERN FLANK WHICH RIGHT NOW IS EXPECTED TO CLIP FAR
NORTHEAST ILLINOIS AND INTO NORTHWEST INDIANA. A MORE PRONOUNCED
BAND OR COUPLE BANDS ARE STARTING TO DEVELOP UPSTREAM WITH THIS
AND SHOULD CONTINUE TO BETTER DEVELOP GIVEN THE FORECAST
CONVERGENCE AND SUGGESTED SOLUTIONS BY CONVECTIVE ALLOWING
GUIDANCE. LAKE-INDUCED CAPE AT THE LEADING EDGE OF THIS LOOKS TO
BE 100-200 J/KG WITH AN EQUILIBRIUM LEVEL AROUND 8000 FT PER
MODIFIED RAP AND NAM SOUNDINGS. THIS WILL LIKELY SUPPORT A BURST
OF MODERATE TO BRIEFLY HEAVY SNOW SHOWERS FOR SOME LOCATIONS
WHERE THIS COMES INLAND...ARRIVING BETWEEN 9-11 AM CURRENTLY
LOOKS LIKE THE BEST FORECAST TIME. HOWEVER THIS BAND/S/ LOOKS TO
HAVE A SNAKE-LIKE SHAPE AND BE FAIRLY PROGRESSIVE...THUS LIMITING
RESIDENCE TIME IN ANY ONE LOCATION AS THE FRONT AND MESOLOW PUSH
SOUTHWARD. SO WHILE A QUICK INCH OR A LITTLE OVER MAY OCCUR FOR
SOME...AMOUNTS AFTER THAT FIRST HOUR OR SO LOOK TO BE LESS. IT
ALSO LOOKS LIKE THE SNOW SHOULD SQUEEZE IN JUST BEHIND THE MORNING
COMMUTE...HELPING TO MINIMIZE IMPACTS SOME. WILL STILL LIKELY
ISSUE AN SPS JUST FOR THE POTENTIAL FOR A RAPID CHANGE IN
VISIBILITY EVEN IF BRIEF.
GOING INTO THE EARLY-MID AFTERNOON BEHIND THE FRONT...LESS
ORGANIZED SNOW SHOWERS OR FLURRIES WILL REMAIN WITH LIGHT
ADDITIONAL ACCUMULATION AS EQUILIBRIUM HEIGHTS LOWER ON A
STRENGTHENING SUBSIDENCE INVERSION. THE EXCEPTION MAY BE LAKE
COUNTY ILLINOIS AND NORTHERN COOK WHERE SOME CONVERGENCE WITH A
LONG FETCH IS FORECAST...SO RESIDENCE TIME OF LIGHT SNOW COULD
HELP TO YIELD AN ADDITIONAL HALF INCH OR MORE...BUT EVEN THAT
LOOKS TO WEAKEN THROUGH THE AFTERNOON AS DRY ADVECTION
STRENGTHENS.
HIGHS TODAY ARE FORECAST TO PEAK IN THE UPPER 20S IN MOST
LOCATIONS WITH GRADUALLY MORE SUNSHINE FORECAST IN THE AFTERNOON
AWAY FROM LAKE INDUCED CLOUDS. TONIGHT SHOULD SEE THE SKY CLEAR
IN MOST IF NOT ALL LOCATIONS. HAVE GONE TOWARD COOLER GFS-BASED
MOS GUIDANCE WITH WINDS DROPPING OFF AND SOME LOCATIONS HAVING A
TAD BIT OF FRESH SNOW. SOME UPPER SINGLE DIGITS ARE PROBABLY A
DECENT BET IN FAVORED COOLER LOCATIONS.
MTF
&&
.LONG TERM...
327 AM CST
TUESDAY NIGHT THROUGH SUNDAY...
A SLOW MODERATION CONTINUES TO BE FORECAST MIDWEEK WITH A
DAMPENING UPPER RIDGE SHIFTING EAST OVER THE AREA AND SOUTHWEST
850-1000MB FLOW DEVELOPING UNDERNEATH. THE BLOCKED PATTERN IN THE
WESTERN CONUS IS FORECAST TO BREAK DOWN WITH A STRONG WEST-TO-EAST
PACIFIC JET EXPANDING INTO SOUTHERN CALIFORNIA. A LEADING SHORT
WAVE EJECTING FROM THIS IS EXPECTED TO MOISTEN THE LOW-LEVEL FLOW
INTO THE MISSISSIPPI VALLEY REGION AND THAT STILL IS FORECAST
DURING LATER WEDNESDAY NIGHT INTO THURSDAY. WOULD NOT BE
SURPRISED TO SEE THIS SLOW DOWN A TAD. TEMPERATURES...
THICKNESSES...AND FORECAST PROFILES IN GENERAL STILL LOOK
SUPPORTIVE OF POTENTIALLY LIGHT SNOW OR A WINTRY MIX AT THE
LEADING EDGE OF SATURATED ASCENT.
THE MORE PRONOUNCED LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP
OVER THE CENTRAL PLAINS THURSDAY NIGHT INTO FRIDAY YIELDING DEEPER
MOISTURE TRANSPORT AND MORE WIDESPREAD LIFT WITHIN UPPER
DIFFLUENCE...ALL SUPPORTING LIKELY RAIN AT THIS JUNCTURE. THE LIFT
AND ESPECIALLY MOISTURE IS PRESENTLY NOT FORECAST TO THE MAGNITUDE
OF SEVERAL OF THE HEAVY RAIN DECEMBER SYSTEMS WE SAW...SO QPF IS
PRESENTLY BELOW AN INCH...BUT STILL ONE HALF TO THREE-QUARTERS OF
AN INCH OF RAIN IN JANUARY ON SATURATED GROUND IS NOTEWORTHY AND
SOMETHING WE WILL HAVE TO WATCH. THE 04.00 GFS CONTINUES JUST A
TAD FURTHER EAST AS DOES ITS ENSEMBLE COMPARED TO THE EC. IT WOULD
REQUIRE A FAIRLY LARGE SHIFT TO GET THE STRONGER COLD ADVECTION
WITH THIS SYSTEM GIVEN ITS SOMEWHAT BROAD NATURE...SO STILL FEEL
GOOD NOT MENTIONING ANY WINTERY PRECIPITATION CHANCES THURSDAY
NIGHT THROUGH FRIDAY NIGHT. EVEN DURING THE WEEKEND...WINTRY
PRECIPITATION PRESENTLY LOOKS TO BE LIGHT IF IT WERE TO
MATERIALIZE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* WINDS SHIFTING TO THE NORTHEAST LATE MORNING OR EARLY AFTERNOON WITH
SPEEDS OF 10-12KT.
* LAKE EFFECT SNOW SHOWERS BEGINNING LATE MORNING AND PERSISTING
INTO THE AFTERNOON. GENERALLY MVFR VIS LIKELY WITH PERIODS OF
VIS 1SM POSSIBLE. OCNL BRIEF PERIODS OF VIS LESS THAN 1SM
POSSIBLE IN HEAVIER BANDS.
* MVFR CIGS LIKELY BY THE TIME OF SNOW ONSET AND CONTINUING INTO
EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 12Z...
WINDS WILL GRADUALLY VEER FROM NWLY TO NELY AS HIGH
PRESSURE BUILDS ACROSS THE UPPER GREAT LAKES TO THE MIDDLE
MISSISSIPPI VALLEY. A WEAK PRESSURE GRADIENT OVER LAKE MICHIGAN
COMBINED WITH AN INFLUX OF COOLER AIR IS SETTING UP A PATTERN
CONDUCIVE TO LAKE EFFECT SNOW. LATEST RADAR IMAGERY ALREADY
INDICATES A WELL FORMED BAND OVER CENTRAL LAKE MICHIGAN WITH AN
APPARENT MESO-LOW APPEARANCE. THE HIGH RESOLUTION MODEL GUIDANCE
IS SUGGESTING THAT THE LAKE EFFECT PLUME COULD REACH THE CHICAGO
AREA TERMINALS A LITTLE FASTER THAN PREVIOUSLY NOTED...AND ALSO
INDICATING AN END TO THE MORE IMPACTING SNOWFALL A LITTLE EARLIER
AS WELL. IT IS LIKELY THAT THE HEAVIEST SNOW COULD IMPACT GYY MORE
SO THAN MDW/ORD/DPA...BUT STILL FEEL THAT THESE TERMINALS SHOULD
STILL SEE A PERIOD OF LAKE EFFECT SNOW DROPPING VISIBILITY TO
PREVAILING MVFR FOR A FEW HOURS OR SO. IT IS STILL POSSIBLE THAT
THERE WILL BE OCNL PERIODS OF LOWER VISIBILITY...1SM OR LESS...BUT
TIMING REMAINS UNCERTAIN AND WILL BE HIGHLY DEPENDENT ON THE
FINER SCALE EVOLUTION AND TRACK OF THE LAKE PLUME. IT IS LIKELY
THAT ORD/MDW COULD SEE AN INCH OR SO OF ACCUMULATION WITH DPA
POSSIBLY SEEING A LITTLE LESS AND GYY SEEING MORE.
THE LARGE SCALE HIGH PRESSURE IS EXPECTED TO SAG ACROSS NERN
IL/SRN LAKE MICHIGAN/NRN INDIANA BY LATE AFTERNOON...SHUTTING OFF
THE LAKE EFFECT SNOW POTENTIAL AND SHIFTING WINDS TO SOUTHEASTERLY
BY EARLY EVENING AND SOUTHERLY OVERNIGHT. MVFR CIGS DEVELOPING
WITH THE LAKE EFFECT SNOW SHOULD CONTINUE INTO THE EARLY
EVENING...BUT AS THE HIGH PRESSURE BUILDS ACROSS THE
REGION...SKIES SHOULD QUICKLY SCATTER OUT AND BECM MOSTLY CLEAR
OVERNIGHT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE IN TIMING OF LAKE EFFECT SNOW. LOW CONFIDENCE
IN TIMING AND DURATION OF VIS DROPPING TO 1SM OR LESS IN HEAVIER
BANDS OF SNOW.
* MEDIUM-HIGH CONFIDENCE IN WIND AND CEILING TRENDS THROUGH THE
PERIOD.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR/WX NIL.
WEDNESDAY...VFR/WX NIL.
THURSDAY...WINTRY MIX OF PCPN EARLY CHANGING OVER TO RAIN IN THE
AFTERNOON AND CONTINUING THROUGH THE NIGHT. MVFR CIG/VIS
LIKELY...IFR CONDITIONS POSSIBLE.
FRIDAY...RAIN LIKELY THROUGH THE DAY AND CONTINUING OVERNIGHT.
MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SATURDAY...CHANCE OF RAIN THROUGH THE DAY...CHANGING OVER TO SNOW
OVERNIGHT. MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF LINGERING LIGHT SNOW MORNING. MVFR CIG/VIS
POSSIBLE MORNING. OTRW...VFR/WX NIL.
KREIN
&&
.MARINE...
345 AM CST
MAIN MARINE CONCERN IN THE NEAR TERM IS A PERIOD OF NORTHWEST TO
NORTHEAST WINDS OF 20-25 KT WITH OCCASIONAL GUSTS TO 30
KT PRODUCING HAZARDOUS CONDITIONS FOR SMALL CRAFT ALONG BOTH THE
ILLINOIS AND INDIANA NEARSHORE WATERS THROUGH LATE THIS AFTERNOON
OR EARLY EVENING. WINDS WILL DIMINISH FAIRLY QUICKLY THIS EVENING
AS HIGH PRESSURE MOVES ACROSS THE LAKE THIS EVENING AND OVERNIGHT
TONIGHT.
WINDS WILL TURN TO THE SOUTH LATE TODAY NIGHT AS THE HIGH MOVES
OFF TO THE EAST... WITH THESE SOUTH WINDS INCREASING AS THE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A FAIRLY DEEP
AREA OF LOW PRESSURE TRACKING ACROSS HUDSON BAY. WINDS WILL RAMP
UP QUICKLY TO 30 KTS AND BECOME SOUTHWESTERLY ON NORTHERN LAKE
MICHIGAN LATE TONIGHT. A PERIOD OF SOUTHWEST GALES IS LIKELY
ACROSS THE NORTH HALF OF THE LAKE TUESDAY AND TUESDAY NIGHT WHEN
THE PRESSURE GRADIENT IS THE STRONGEST. THE GRADIENT WILL THEN
RELAX A BIT BY EARLY WEDNESDAY...AND WILL EVENTUALLY BACK TO THE
EAST THURSDAY NIGHT AS ANOTHER LOW LIFTS NORTHEAST FROM THE
SOUTHERN PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM MONDAY.
&&
$$
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...UPDATED
National Weather Service Topeka KS
525 AM CST MON JAN 4 2016
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 326 AM CST MON JAN 4 2016
Sfc high pressure now centered across eastern NE will slide
southeast through the day. The stratus deck should continue to build
west through sunrise with an area of fog expected to develop along
the western periphery of the stratus deck across north central and
perhaps southeast KS. There have been some flurries with this deck
and soundings do show the top of the cloud to be in the -8 to -9C
range so can`t rule out a few flurries early this morning. Biggest
impact aside from morning fog will be for stratus and ENE winds to
keep highs colder than guidance and will generally keep diurnal to
less than 10F all areas today with mocldy skies.
Tonight skies may remain mocldy as WAA begins to take place atop the
moist boundary layer thereby trapping the stratus deck. Despite the
WAA and a modest veering profile in the lowest 3kft lift is
neutral at worst so conds should stay dry tonight.
.LONG TERM...(Tuesday through Sunday)
Issued at 326 AM CST MON JAN 4 2016
The long term forecast continues to focus on a prolonged period of
clouds and precipitation chances, with a few time frames within this
longer period becoming more interesting in terms of colder
temperatures and chances for winter precipitation.
On Tuesday, upper ridging will shift east of the area, giving way to
southwesterly flow as the first of several short wave troughs
approaches the central Plains. Tuesday itself should be in the low
40s, although with increasing high cloud cover through the day. By
late in the day, expect clouds to further increase, with a low
stratus shield building into the area by evening. Cloud cover is
likely to play an important role in the weather for Tuesday night
into Wednesday as the timing of the thicker clouds will impact
temperatures. As the forecast stands, expect temperatures to fall
into the 28-32 range by late Tuesday evening. At that time, the
initial short wave trough will be focusing lift over the forecast
area. The lift will not be particularly strong, and moisture
profiles marginal but sufficient for precipitation, but there is a
strong signal that it will be enough to produce some drizzle and
periods of snow. Instability above 500 hPa suggests even a few
pockets of brief moderate snow are possible. All-in-all, the system
is rather unorganized but will still need to watch for areas of
light icing from freezing drizzle as well as a few areas potentially
receiving an inch or less of snow through Wednesday morning.
Warm advection will continue Wednesday into Thursday and
temperatures are likely to be above freezing for this period
starting around noon Wednesday. Low level lift will continue even in
between stronger forcing associated with short wave troughs, so will
have periods of drizzle or light rain interspersed with periods of
moderate rain as deeper lift moves overhead. This more widespread
rain is likely to occur during the day on Thursday and into Thursday
night as a stronger piece of energy moves across the region.
Thursday night into Friday night, uncertainty increases regarding
temperature profiles and precipitation type...particularly over
northern Kansas. During this period, the series of upper energy will
continue to bring periods of lift to the region, with continuation
of periods of drizzle also seeming likely when deeper lift is
absent. On the whole, recent model guidance has trended colder with
the temperature profiles and generally a bit south with the broader
precipitation shield. This would suggest a better chance for
accumulating snow in northwest parts of the forecast area...
specifically north of a line from Concordia to Marysville. Even now,
temperature profiles in this area are borderline for rain vs snow
through much of this period, becoming more confident in supporting
snow as the precipitation becomes lighter and ends. Currently
believe that there is at least some potential for a few inches of
snow to fall in this area, although there is basically equal
potential for much of this to fall as rain with little to no snow.
Furthermore, any further shift to the south of the current forecast
track of the storm would point to increased chances for increased
snow accumulation.
Saturday through the coming week look to show a strong cooling
trend, with temperatures well below normal for much of next week.
Have trended temperatures toward the cold end of guidance from
Saturday on.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday Morning)
Issued at 521 AM CST MON JAN 4 2016
Given expected weak mixing in the boundary layer and with the sfc
high sliding off to our NE expect skies to remain mocldy with CIGS
expected to only gradually rise toward 1kft by midday. Prefer the
NAM and RAP soundings which seem to be handling the stratus better
at this time. Confidence is low whether we will see the stratus
lift or become scattered by this afternoon so will keep CIGS
around 1kft through the period per NAM bufkit soundings.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Omitt
LONG TERM...Barjenbruch
AVIATION...Omitt
AREA FORECAST DISCUSSION
NWS JACKSON KY
1020 AM EST MON JAN 4 2016
.UPDATE...
ISSUED AT 1020 AM EST MON JAN 4 2016
PORTIONS OF THE REGION CONTINUE TO SEE SOME SNOW SHOWERS/SQUALLS
MOVING THROUGH THE REGION...MAINLY ACROSS THE FAR EAST AND
SOUTHEAST THIS HOUR. MANY REPORTS FROM SOCIAL MEDIA SHOWING SNOW
COVERED ROADS AND QUICKLY REDUCING VIS. THEREFORE WE HAVE
MAINTAINED SPS PRODUCTS TO COVER THESE. THERE IS ALSO ANOTHER
AREA OF SNOW SHOWERS MOVING THROUGH THE NW PORTIONS OF THE CWA.
THERE IS SOME MORE ACTIVITY UPSTREAM IN INDIANA...BUT SEEMS
UNLIKELY AT THIS POINT THESE WILL BE ABLE TO SUSTAIN AND MAKE IT
INTO THE REGION. THE MODELS ARE HAVING A TOUGH TIME GIVEN THE TYPE
OF EVENT...BUT IN GENERAL THE STORM SCALE MODELS SEEM TO BE DOING
THE BEST THUS FAR. WILL CONTINUE WITH THE NOTION OF REDUCTION IN
COVERAGE AS WE MOVE THROUGH THE AFTERNOON...THEREFORE NOT MUCH
CHANGE TO THE OVERALL FORECAST AT THIS POINT. THOSE OUTSIDE OF
THESE SNOW SHOWERS EXPECT FLURRIES TO MOSTLY CLOUDY SKIES. MADE
SOME MINOR ADJUSTMENTS TO TEMPS/DEWS/WINDS TO ACCOUNT FOR LATEST
OBS.
UPDATE ISSUED AT 755 AM EST MON JAN 4 2016
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT RADAR TRENDS AND
OBSERVATIONS. SOME SQUALLS HAVE BROUGHT A QUARTER OF AN INCH
QUICKLY IN SOME LOCATIONS AND SOME WIND GUSTS AS WELL. WE WILL
CONTINUE TO HIGHLIGHT THESE IN THE HWO...AND SPS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 412 AM EST MON JAN 4 2016
A FEW FLURRIES HAVE OCCURRED EARLIER HERE AT JKL...ALTHOUGH
NOTHING IS FALLING AT PRESENT. A FEW FLURRIES WERE REPORTED IN
EASTERN POWELL COUNTY AND IN BELL COUNTY OVERNIGHT. PER RECENT
RADAR RETURNS FLURRIES OR LIGHT SNOW SHOWERS ARE PROBABLY
OCCURRING IN THE BIG SANDY REGION AND NEAR INTERSTATE 64...BUT WE
HAVE NOT HAD ANY GROUND TRUTH REPORTS OF THAT FROM THAT AREA THUS
FAR. MORE SIGNIFICANT SNOW SHOWERS OR EVEN A FEW SNOW SQUALLS ARE
CURRENTLY UPSTREAM OVER SOUTHWESTERN OH AND EASTERN INDIANA AND
POISED TO DROP INTO EASTERN KY TODAY. UP TO A HALF OF AN INCH HAS
RECENTLY BEEN REPORTED FROM THE SNOW SHOWERS IN SOUTHWESTERN OH.
THE MAIN FORECAST CHALLENGE IN THE NEAR TERM IS THE SNOW SHOWERS
AND A FEW SNOW SQUALLS ANTICIPATED TODAY AS THE COLD FRONT AND AN
UPPER LEVEL DISTURBANCE WORK INTO AND ACROSS THE REGION AND THE
COMBINATION OF SOLAR INSOLATION AND COLDER AIR WORKING IN ALOFT
STEEPENS LAPSE RATES. THERE REMAINS MODEL UNCERTAINTY WITH THESE
AS THE NAM AND GFS HAVE EITHER ONE OR TWO LOCATIONS WHERE SNOW
SHOWERS SHOULD BE MOST PREVALENT AS DOES THE RECENT RAP RUNS. THE
0Z NAM AND THE 0Z GFS AS DOES THE 6Z NAM AS A MAX NEAR THE
INTERSTATE 75 CORRIDOR AND ANOTHER OVER THE NORTHERN TO EASTERN
PART OF THE CWA. THE RECENT RAP RUNS HAVE THE MAX GENERALLY FORM
ELLIOTT COUNTY TO MAGOFFIN COUNTY TO LETCHER COUNTY. WIDESPREAD
FLURRIES AND LIGHT SNOW SHOWERS ARE A CERTAINTY TODAY...WITH A FEW
LOCATIONS PICKING UP SNOW SQUALLS WITH GUSTS TO 20 MPH OR MORE AND
QUICK QUARTER OF AN INCH OR EVEN MULTIPLE SNOW SQUALLS. THE NNW
FLOW WOULD GENERALLY FAVOR THE HIGH TERRAIN OF SOUTHEASTERN KY IN
MOST INSTANCES FOR THE GREATEST ACCUMULATION AND OF COURSE
LOCATIONS THAT PICK UP MULTIPLE SNOW SQUALLS. MOST LOCATIONS WILL
PROBABLY NOT PICK UP MUCH MORE THAN A QUARTER OF AN INCH...ALTHOUGH
SOME OF THE HIGHER TERRAIN IN THE SOUTHEAST AND ANY LOCATIONS THAT
EXPERIENCE MULTIPLE SNOW SQUALLS MAY GET OVER A HALF OF AN INCH.
AN SPS WAS REFRESHED HIGHLIGHTING THIS. THE SNOW SHOWERS AND
SQUALLS SHOULD BE MOST PREVALENT DURING THE MORNING TO EARLY
AFTERNOON...AND THEN BEGIN TO WANE AS DRIER AIR FILTERS IN AT THE
LOW LEVELS. TEMPERATURES SHOULD ONLY HAVE A LIMITED RISE DURING
THE DAY TODAY.
SFC HIGH PRESSURE BUILDING IN BEHIND THE FRONT SHOULD SET THE
STAGE FOR CHILLY OVERNIGHT LOWS TONIGHT AND BELOW NORMAL
TEMPERATURES AGAIN ON TUESDAY. THERE REMAINS SOME UNCERTAINTY IN
HOW QUICKLY VALLEY LOCATIONS CAN DECOUPLE AND STRATOCU DISSIPATE...
BUT ADVECTION ALONE SHOULD BRING TEMPERATURES INTO THE TEENS IN
ALL AREAS. READINGS IN THE NORMALLY COLDER VALLEYS COULD BE A
COUPLE OF DEGREES BELOW THE CURRENT FORECAST IF DECOUPLING AND OR
CLEARING IS QUICKER. THESE WIDESPREAD READINGS IN THE TEEN SHOULD
BE THE COLDEST MOST LOCATIONS HAVE BEEN IN THE PAST 10 MONTHS OR
SO...SINCE MARCH 6 OR MARCH 7 OF 2015. TUESDAY SHOULD BE MOSTLY
SUNNY TO SUNNY WITH A FEW PASSING CIRRUS IN THE AFTERNOON...AND
FEATURE HIGHS IN THE 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM EST MON JAN 4 2016
THE EXTENDED PERIOD OF THE FORECAST WILL FEATURE A PERIOD OF DRY AND
WARMER THAN NORMAL WEATHER WEDNESDAY AND MOST OF THURSDAY. THE WARM
WEATHER WILL CONTINUE THROUGH THE UPCOMING WEEKEND...BUT A COUPLE OF
PASSING WEATHER SYSTEM WILL BRING CHANCES OF RAIN TO THE AREA FROM
THURSDAY EVENING ONWARD. THE BEST CHANCE OF RAIN WILL BE FROM
THURSDAY NIGHT THROUGH FRIDAY...AS WELL DEVELOPED AREA OF LOW
PRESSURE MOVES ACROSS THE MID MISSISSIPPI VALLEY AND INTO THE GREAT
LAKES THURSDAY NIGHT AND FRIDAY. THE MODELS WERE IN PRETTY GOOD
AGREEMENT WITH THIS FIRST WEATHER SYSTEM...SO LIKELY POPS SEEMED
REASONABLE FOR THE THURSDAY NIGHT FRIDAY TIME FRAME...WITH A GRADUAL
DECREASE IN RAIN CHANCES FRIDAY NIGHT AND SATURDAY. DECIDED TO KEEP
THE RAIN CHANCES IN PLAY FOR SATURDAY AND SATURDAY NIGHT TO ACCOUNT
FOR THE PRESENCE OF WHAT APPEARS TO BE A WEAK SURFACE BOUNDARY THAT
THE ECMWF MODEL IS KEEPING IN PLACE ACROSS CENTRAL KENTUCKY AND
WESTERN TENNESSEE. A SECOND DISTURBANCE IS FORECAST TO PASS THROUGH
THE REGION SUNDAY AND SUNDAY NIGHT...BUT THE MODELS ARE IN POOR
AGREEMENT AS TO THE EXACT TRACK OF THIS SYSTEM. THE GFS HAS THE
WEEKEND LOW PRESSURE MOVING BY FAR ENOUGH TO OUR SOUTH AND SOUTHEAST
TO KEEP THE AREA MOSTLY DRY...WHILE THE ECMWF MODEL TAKES THE SAME
LOW ACROSS CENTRAL KENTUCKY AND INTO THE OHIO VALLEY. THE ECMWF
SCENARIO WOULD BRING ANOTHER GOOD CHANCE OF RAIN TO THE AREA...WHILE
THE GFS WOULD GIVE US LITTLE IF ANY PRECIPITATION. THAT BEING
SAID...DECIDED TO SIDE MORE WITH THE ECMWF MODEL FOR THE END OF THE
PERIOD AND GOING WITH SMALL RAIN CHANCES TO FINISH OUT THE WEEKEND.
TEMPERATURES LATE SUNDAY NIGHT MAY GET CLOSE ENOUGH TO FREEZING TO
ALLOW A FEW FLAKES OF SNOW TO MIX IN WITH ANY RAIN THAT FALLS.
DAY TIME HIGHS DURING THE PERIOD ARE EXPECTED TO TOP OUT IN THE 50S
THURSDAY THROUGH SATURDAY...AND IN THE 40S ON WEDNESDAY AND SUNDAY.
OVERNIGHT LOWS WILL VARY GREATLY DUE TO THE PASSAGE OF THE TWO
AFOREMENTIONED WEATHER SYSTEMS. THE COLDEST AIR OF THE WINTER SEASON
IS EXPECTED TO SETTLE OVER THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING...AS A POLAR AIR MASS SETTLES OVER THE OHIO AND TENNESSEE
VALLEY REGIONS. MINIMUM TEMPERATURES ON WEDNESDAY MORNING ARE
EXPECTED TO DROP INTO THE TEENS AREA WIDE...WITH OUR VALLEY
LOCATIONS PERHAPS SEEING THE LOW TO MID TEENS. WEDNESDAY NIGHT WILL
SEE A SLIGHT WARM UP AS THE AIR MASS MODIFIES A BIT BENEATH MOSTLY
SUNNY SKIES DURING THE DAY. LOWS WEDNESDAY NIGHT ARE FORECAST TO
ONLY FALL INTO THE UPPER 20S. WE SHOULD SEE LOWS GENERALLY IN THE
LOWER 40S THURSDAY NIGHT THROUGH SATURDAY NIGHT AS WINDS SHIFT
AROUND TO THE SOUTH AND CLOUD COVER OVERSPREADS THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 805 AM EST MON JAN 4 2016
SNOW SHOWERS AND FLURRIES ARE GENERALLY BRINGING IN MVFR TO VFR
CIGS AND VIS IN MOST LOCATIONS. HOWEVER...IFR TO EVEN BELOW
AIRPORT MINS ARE POSSIBLE IN HEAVIER SNOW SHOWERS AND SQUALLS
DROPPING ACROSS THE AREA EARLY IN THE PERIOD...AT JKL AND SJS.
THESE COULD ALSO NEAR LOZ. BY THE 20Z TO 0Z PERIOD MOST LOCATIONS
SHOULD RETURN TO VFR. GUSTY CONDITIONS WILL BE POSSIBLE WITH ANY
SNOW SQUALLS. OTHERWISE MOST SITES WILL SEE WINDS FROM THE
NORTHWEST TO NORTH AT KT OR LESS THROUGH THE PERIOD...WITH WINDS
SLACKENING BY 0Z TO 6Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...JP
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
810 AM EST MON JAN 4 2016
.UPDATE...
ISSUED AT 755 AM EST MON JAN 4 2016
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT RADAR TRENDS AND
OBSERVATIONS. SOME SQUALLS HAVE BROUGHT A QUARTER OF AN INCH
QUICKLY IN SOME LOCATIONS AND SOME WIND GUSTS AS WELL. WE WILL
CONTINUE TO HIGHLIGHT THESE IN THE HWO...AND SPS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 412 AM EST MON JAN 4 2016
A FEW FLURRIES HAVE OCCURRED EARLIER HERE AT JKL...ALTHOUGH
NOTHING IS FALLING AT PRESENT. A FEW FLURRIES WERE REPORTED IN
EASTERN POWELL COUNTY AND IN BELL COUNTY OVERNIGHT. PER RECENT
RADAR RETURNS FLURRIES OR LIGHT SNOW SHOWERS ARE PROBABLY
OCCURRING IN THE BIG SANDY REGION AND NEAR INTERSTATE 64...BUT WE
HAVE NOT HAD ANY GROUND TRUTH REPORTS OF THAT FROM THAT AREA THUS
FAR. MORE SIGNIFICANT SNOW SHOWERS OR EVEN A FEW SNOW SQUALLS ARE
CURRENTLY UPSTREAM OVER SOUTHWESTERN OH AND EASTERN INDIANA AND
POISED TO DROP INTO EASTERN KY TODAY. UP TO A HALF OF AN INCH HAS
RECENTLY BEEN REPORTED FROM THE SNOW SHOWERS IN SOUTHWESTERN OH.
THE MAIN FORECAST CHALLENGE IN THE NEAR TERM IS THE SNOW SHOWERS
AND A FEW SNOW SQUALLS ANTICIPATED TODAY AS THE COLD FRONT AND AN
UPPER LEVEL DISTURBANCE WORK INTO AND ACROSS THE REGION AND THE
COMBINATION OF SOLAR INSOLATION AND COLDER AIR WORKING IN ALOFT
STEEPENS LAPSE RATES. THERE REMAINS MODEL UNCERTAINTY WITH THESE
AS THE NAM AND GFS HAVE EITHER ONE OR TWO LOCATIONS WHERE SNOW
SHOWERS SHOULD BE MOST PREVALENT AS DOES THE RECENT RAP RUNS. THE
0Z NAM AND THE 0Z GFS AS DOES THE 6Z NAM AS A MAX NEAR THE
INTERSTATE 75 CORRIDOR AND ANOTHER OVER THE NORTHERN TO EASTERN
PART OF THE CWA. THE RECENT RAP RUNS HAVE THE MAX GENERALLY FORM
ELLIOTT COUNTY TO MAGOFFIN COUNTY TO LETCHER COUNTY. WIDESPREAD
FLURRIES AND LIGHT SNOW SHOWERS ARE A CERTAINTY TODAY...WITH A FEW
LOCATIONS PICKING UP SNOW SQUALLS WITH GUSTS TO 20 MPH OR MORE AND
QUICK QUARTER OF AN INCH OR EVEN MULTIPLE SNOW SQUALLS. THE NNW
FLOW WOULD GENERALLY FAVOR THE HIGH TERRAIN OF SOUTHEASTERN KY IN
MOST INSTANCES FOR THE GREATEST ACCUMULATION AND OF COURSE
LOCATIONS THAT PICK UP MULTIPLE SNOW SQUALLS. MOST LOCATIONS WILL
PROBABLY NOT PICK UP MUCH MORE THAN A QUARTER OF AN INCH...ALTHOUGH
SOME OF THE HIGHER TERRAIN IN THE SOUTHEAST AND ANY LOCATIONS THAT
EXPERIENCE MULTIPLE SNOW SQUALLS MAY GET OVER A HALF OF AN INCH.
AN SPS WAS REFRESHED HIGHLIGHTING THIS. THE SNOW SHOWERS AND
SQUALLS SHOULD BE MOST PREVALENT DURING THE MORNING TO EARLY
AFTERNOON...AND THEN BEGIN TO WANE AS DRIER AIR FILTERS IN AT THE
LOW LEVELS. TEMPERATURES SHOULD ONLY HAVE A LIMITED RISE DURING
THE DAY TODAY.
SFC HIGH PRESSURE BUILDING IN BEHIND THE FRONT SHOULD SET THE
STAGE FOR CHILLY OVERNIGHT LOWS TONIGHT AND BELOW NORMAL
TEMPERATURES AGAIN ON TUESDAY. THERE REMAINS SOME UNCERTAINTY IN
HOW QUICKLY VALLEY LOCATIONS CAN DECOUPLE AND STRATOCU DISSIPATE...
BUT ADVECTION ALONE SHOULD BRING TEMPERATURES INTO THE TEENS IN
ALL AREAS. READINGS IN THE NORMALLY COLDER VALLEYS COULD BE A
COUPLE OF DEGREES BELOW THE CURRENT FORECAST IF DECOUPLING AND OR
CLEARING IS QUICKER. THESE WIDESPREAD READINGS IN THE TEEN SHOULD
BE THE COLDEST MOST LOCATIONS HAVE BEEN IN THE PAST 10 MONTHS OR
SO...SINCE MARCH 6 OR MARCH 7 OF 2015. TUESDAY SHOULD BE MOSTLY
SUNNY TO SUNNY WITH A FEW PASSING CIRRUS IN THE AFTERNOON...AND
FEATURE HIGHS IN THE 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM EST MON JAN 4 2016
THE EXTENDED PERIOD OF THE FORECAST WILL FEATURE A PERIOD OF DRY AND
WARMER THAN NORMAL WEATHER WEDNESDAY AND MOST OF THURSDAY. THE WARM
WEATHER WILL CONTINUE THROUGH THE UPCOMING WEEKEND...BUT A COUPLE OF
PASSING WEATHER SYSTEM WILL BRING CHANCES OF RAIN TO THE AREA FROM
THURSDAY EVENING ONWARD. THE BEST CHANCE OF RAIN WILL BE FROM
THURSDAY NIGHT THROUGH FRIDAY...AS WELL DEVELOPED AREA OF LOW
PRESSURE MOVES ACROSS THE MID MISSISSIPPI VALLEY AND INTO THE GREAT
LAKES THURSDAY NIGHT AND FRIDAY. THE MODELS WERE IN PRETTY GOOD
AGREEMENT WITH THIS FIRST WEATHER SYSTEM...SO LIKELY POPS SEEMED
REASONABLE FOR THE THURSDAY NIGHT FRIDAY TIME FRAME...WITH A GRADUAL
DECREASE IN RAIN CHANCES FRIDAY NIGHT AND SATURDAY. DECIDED TO KEEP
THE RAIN CHANCES IN PLAY FOR SATURDAY AND SATURDAY NIGHT TO ACCOUNT
FOR THE PRESENCE OF WHAT APPEARS TO BE A WEAK SURFACE BOUNDARY THAT
THE ECMWF MODEL IS KEEPING IN PLACE ACROSS CENTRAL KENTUCKY AND
WESTERN TENNESSEE. A SECOND DISTURBANCE IS FORECAST TO PASS THROUGH
THE REGION SUNDAY AND SUNDAY NIGHT...BUT THE MODELS ARE IN POOR
AGREEMENT AS TO THE EXACT TRACK OF THIS SYSTEM. THE GFS HAS THE
WEEKEND LOW PRESSURE MOVING BY FAR ENOUGH TO OUR SOUTH AND SOUTHEAST
TO KEEP THE AREA MOSTLY DRY...WHILE THE ECMWF MODEL TAKES THE SAME
LOW ACROSS CENTRAL KENTUCKY AND INTO THE OHIO VALLEY. THE ECMWF
SCENARIO WOULD BRING ANOTHER GOOD CHANCE OF RAIN TO THE AREA...WHILE
THE GFS WOULD GIVE US LITTLE IF ANY PRECIPITATION. THAT BEING
SAID...DECIDED TO SIDE MORE WITH THE ECMWF MODEL FOR THE END OF THE
PERIOD AND GOING WITH SMALL RAIN CHANCES TO FINISH OUT THE WEEKEND.
TEMPERATURES LATE SUNDAY NIGHT MAY GET CLOSE ENOUGH TO FREEZING TO
ALLOW A FEW FLAKES OF SNOW TO MIX IN WITH ANY RAIN THAT FALLS.
DAY TIME HIGHS DURING THE PERIOD ARE EXPECTED TO TOP OUT IN THE 50S
THURSDAY THROUGH SATURDAY...AND IN THE 40S ON WEDNESDAY AND SUNDAY.
OVERNIGHT LOWS WILL VARY GREATLY DUE TO THE PASSAGE OF THE TWO
AFOREMENTIONED WEATHER SYSTEMS. THE COLDEST AIR OF THE WINTER SEASON
IS EXPECTED TO SETTLE OVER THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING...AS A POLAR AIR MASS SETTLES OVER THE OHIO AND TENNESSEE
VALLEY REGIONS. MINIMUM TEMPERATURES ON WEDNESDAY MORNING ARE
EXPECTED TO DROP INTO THE TEENS AREA WIDE...WITH OUR VALLEY
LOCATIONS PERHAPS SEEING THE LOW TO MID TEENS. WEDNESDAY NIGHT WILL
SEE A SLIGHT WARM UP AS THE AIR MASS MODIFIES A BIT BENEATH MOSTLY
SUNNY SKIES DURING THE DAY. LOWS WEDNESDAY NIGHT ARE FORECAST TO
ONLY FALL INTO THE UPPER 20S. WE SHOULD SEE LOWS GENERALLY IN THE
LOWER 40S THURSDAY NIGHT THROUGH SATURDAY NIGHT AS WINDS SHIFT
AROUND TO THE SOUTH AND CLOUD COVER OVERSPREADS THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 805 AM EST MON JAN 4 2016
SNOW SHOWERS AND FLURRIES ARE GENERALLY BRINGING IN MVFR TO VFR
CIGS AND VIS IN MOST LOCATIONS. HOWEVER...IFR TO EVEN BELOW
AIRPORT MINS ARE POSSIBLE IN HEAVIER SNOW SHOWERS AND SQUALLS
DROPPING ACROSS THE AREA EARLY IN THE PERIOD...AT JKL AND SJS.
THESE COULD ALSO NEAR LOZ. BY THE 20Z TO 0Z PERIOD MOST LOCATIONS
SHOULD RETURN TO VFR. GUSTY CONDITIONS WILL BE POSSIBLE WITH ANY
SNOW SQUALLS. OTHERWISE MOST SITES WILL SEE WINDS FROM THE
NORTHWEST TO NORTH AT KT OR LESS THROUGH THE PERIOD...WITH WINDS
SLACKENING BY 0Z TO 6Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...JP
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
652 AM EST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EST MON JAN 4 2016
WV IMAGERY AND RAP ANALYSIS INDICATED NRLY MID/UPPER LEVEL FLOW
THROUGH THE WRN LAKES BTWN A RIDGE OVER THE PLAINS AND A TROUGH FROM
QUEBEC INTO THE ERN LAKES. STRONG 700-300 MB QVECTOR DIV AND
RESULTING SUBSIDENCE FROM NRN ONTARIO THROUGH LAKE SUPERIOR AND
UPPER MI HAS BROUGHT A DIMINISHING TREND TO THE LES AS THE SHRTWV
THAT MOVED THROUGH LAKE SUPERIOR SUN EVENING MOVES INTO THE ERN
LAKES. ALTHOUGH INVERSION HEIGHTS HAVE DROPPED TO AROUND 4K
FT...INSTABILITY ASSOCIATED WITH 850 MB TEMPS NEAR -18C STILL
SUPPORTED SCT/NMRS LIGHT SNOW SHOWERS IN THE NNE LOW LEVEL FLOW.
TODAY...MID LEVEL AND SFC RIDGING WILL BUILD INTO THE WRN LAKES
TODAY BRINGING AN END TO THE LES THIS MORNING AS INVERSION HEIGHTS
DROP BLO 3K FT AND WINDS BECOME VARIABLE BY MIDDAY. THERE MAY STILL
BE SOME MINOR ADDITIONAL ACCUMULATIONS N CNTRL OF A HALF INCH OR LESS
AFTER 12Z. SW WINDS THIS AFTERNOON WILL HELP BRING SOME
CLEARING. EVEN WITH SOME AFTERNOON SUN...TEMPS WILL REMAIN AT OR
BELOW NORMAL WITH HIGHS AROUND 20. THE COLDEST AIR WILL REMAINED
ENTRENCHED OVER THE EAST NEAR KERY WHERE MAX READINGS REMAIN BLO 15.
TONIGHT...SW WINDS WILL INCREASE AS THE GRADIENT TIGHTENS BETWEEN
THE DEPARTING HIGH AND A TROUGH INTO THE NRN PLAINS. BOUNDARY LAYER
WINDS IN THE 10-20 KNOT RANGE WILL KEEP TEMPS FROM DROPPING OFF TOO
FAR WITH MINS FROM 10 TO 15 INLAND TO AROUND 20 NEAR LAKE SUPERIOR
WHERE DOWNSLOPE FLOW PREVAILS. THE SW WINDS OFF OF LAKE MI WITH 900
MB TEMPS AROUND -10C WILL SUPPORT A BAND OF CLOUDS AND SOME FLURRIES
BUT SHOULD REMAIN TO THE SE OF THE CWA OR JUST CLIP FAR SE LUCE
COUNTY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM EST MON JAN 4 2016
NO SIGNIFICANT WEATHER FOR TUE...BUT A SHORTWAVE WILL MOVE ACROSS
HUDSON BAY TUE INTO TUE NIGHT...DROPPING A SFC TROUGH/FRONT INTO THE
CWA WHERE IT WILL STALL INTO LATE WEEK UNTIL ANOTHER SYSTEM MOVES
THROUGH. COLDER AIR AND WSW WINDS MAY LEAD TO SOME LIGHT LES OVER
MAINLY THE KEWEENAW TUE NIGHT INTO WED MORNING. A WEAK SHORTWAVE
LOOKS TO MOVE ALONG THE FRONT WED NIGHT INTO THU MORNING...WHICH
WILL RESULT IN ADDITIONAL FORCING FOR WIDESPREAD LIGHT TO LOCALLY
MODERATE SNOW. AT THIS TIME...IT LOOKS LIKE THE MODERATE SNOW WILL
FALL OVER LAKE SUPERIOR OR TO THE NW OF THE CWA...BUT RUN TO RUN
CONTINUITY IS NOT GREAT WITH THE SYSTEM WHICH IS EXPECTED AT THAT
TIME FRAME WITH THIS TIME OF SETUP. THINK MOST OR ALL AREAS OF UPPER
MI WILL SEE SUB-ADVISORY AMOUNTS...BUT IF THE BETTER BAND OF SNOW
MOVES OVER WE WOULD PROBABLY SEE ADVISORY AMOUNTS. MAIN TIME FRAME
FOR THE WIDESPREAD SNOW IS WED EVENING INTO THU MORNING.
COULD SEE SOME DRIZZLE/FREEZING DRIZZLE WITH UPSLOPE OVER THE
KEWEENAW AFTER THE SYSTEM SNOW MOVES OUT THU AND AHEAD OF THE NEXT
SYSTEM...BUT THAT IS LOW CHANCE AND LOW CONFIDENCE SO WILL CONTINUE
TO JUST KEEP IT SNOW SHOWERS.
LOTS OF UNCERTAINTY WITH A LATE WEEK INTO THE WEEKEND SYSTEM AS
MODELS HAVE DISAGREEMENT AND RUN TO RUN DISCONTINUITY. MODELS SHOW A
SERIES OF SHORTWAVES LEADING TO A BROAD UPPER TROUGH AND SFC LOW.
SHOULD SEE LIGHT SNOW MOVE IN THU NIGHT/FRI MORNING...POSSIBLY
MIXING WITH OR TURNING TO RAIN OVER MAINLY SOUTHEASTERN UPPER MI FRI
EVENING INTO FRI NIGHT...BUT MODELS HAVE TRENDED COLDER IN THE
LATEST RUNS. PRECIP THEN TURNS BACK TO ALL LIGHT SNOW AND PERSISTS
THROUGH SAT. NOT LOOKING AT ANY SIGNIFICANT SNOWFALL RATES...BUT
IT DOES LOOK LIKE PERSISTENT LIGHT SNOWFALL FOR AROUND 36 HOURS.
SAT NIGHT AND SUN ARE QUITE UNCERTAIN IN EXACT DETAILS...BUT ANOTHER
SHORTWAVE DIVING INTO THE REGION LOOKS TO BRING MUCH COLDER AIR
(POSSIBLY THE COLDEST OF THE SEASON)...SO AT LEAST NW WIND LAKE
EFFECT APPEARS PROBABLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 651 AM EST MON JAN 4 2016
STRONG SUBSIDENCE BEHIND A DEPARTING SHRTWV/LOW PRES TROUGH WILL
CAUSE THE INTENSITY OF ONGOING LES TO DIMINISH THROUGH THIS MORNING.
THE MOST PERSISTENT SHSN WILL IMPACT SAW...WHERE UPSLOPE NNE WIND
AND CLOSER PROXIMITY TO THE COLDER AIR WL RESULT IN PERIODS OF MAINLY
MVFR VSBY EARLY. AT CMX/IWD...LESS FVRBL NNE WIND WILL BRING WITH
MVFR CIGS THIS MORNING AND VFR VSBY. STRONG SUBSIDENCE ASSOCIATED
WITH HIGH PRES BUILDING INTO THE AREA WILL BRING VFR CONDITIONS TO
ALL THE TAF SITES THIS AFTERNOON AND TONIGHT. INCREASING SW WINDS
ABOVE A STABLE BOUNDARY LAYER WILL RESULT IN LLWS TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EST MON JAN 4 2016
HIGH PRESSURE WILL QUICKLY BUILD ACROSS THE LAKE THIS MORNING AND
THEN QUICKLY MOVE SOUTH OF THE AREA THIS AFTERNOON. BEHIND THE
HIGH...SOUTHWEST WINDS WILL INCREASE TO GALES FORCE TONIGHT INTO TUE
EVENING AHEAD OF THE NEXT FROTNAL SYSTEM. THE GALE WATCH WAS UPGRADED
TO A WARNING FOR THIS PERIOD. THE FRONT STALLS OUT NEAR LAKE SUPERIOR
FOR WED-FRI...LEADING TO WINDS GENERALLY LESS THAN 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ005.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ006.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TUESDAY TO 1 AM EST WEDNESDAY FOR
LSZ265>267.
GALE WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 10 PM EST
/9 PM CST/ TUESDAY FOR LSZ162.
GALE WARNING FROM 10 PM THIS EVENING TO 1 AM EST WEDNESDAY FOR
LSZ263-264.
LAKE MICHIGAN...
GALE WATCH FROM TUESDAY MORNING THROUGH LATE TUESDAY NIGHT FOR
LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
521 AM EST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EST MON JAN 4 2016
WV IMAGERY AND RAP ANALYSIS INDICATED NRLY MID/UPPER LEVEL FLOW
THROUGH THE WRN LAKES BTWN A RIDGE OVER THE PLAINS AND A TROUGH FROM
QUEBEC INTO THE ERN LAKES. STRONG 700-300 MB QVECTOR DIV AND
RESULTING SUBSIDENCE FROM NRN ONTARIO THROUGH LAKE SUPERIOR AND
UPPER MI HAS BROUGHT A DIMINISHING TREND TO THE LES AS THE SHRTWV
THAT MOVED THROUGH LAKE SUPERIOR SUN EVENING MOVES INTO THE ERN
LAKES. ALTHOUGH INVERSION HEIGHTS HAVE DROPPED TO AROUND 4K
FT...INSTABILITY ASSOCIATED WITH 850 MB TEMPS NEAR -18C STILL
SUPPORTED SCT/NMRS LIGHT SNOW SHOWERS IN THE NNE LOW LEVEL FLOW.
TODAY...MID LEVEL AND SFC RIDGING WILL BUILD INTO THE WRN LAKES
TODAY BRINGING AN END TO THE LES THIS MORNING AS INVERSION HEIGHTS
DROP BLO 3K FT AND WINDS BECOME VARIABLE BY MIDDAY. THERE MAY STILL
BE SOME MINOR ADDITIONAL ACCUMULATIONS N CNTRL OF A HALF INCH OR LESS
AFTER 12Z. SW WINDS THIS AFTERNOON WILL HELP BRING SOME
CLEARING. EVEN WITH SOME AFTERNOON SUN...TEMPS WILL REMAIN AT OR
BELOW NORMAL WITH HIGHS AROUND 20. THE COLDEST AIR WILL REMAINED
ENTRENCHED OVER THE EAST NEAR KERY WHERE MAX READINGS REMAIN BLO 15.
TONIGHT...SW WINDS WILL INCREASE AS THE GRADIENT TIGHTENS BETWEEN
THE DEPARTING HIGH AND A TROUGH INTO THE NRN PLAINS. BOUNDARY LAYER
WINDS IN THE 10-20 KNOT RANGE WILL KEEP TEMPS FROM DROPPING OFF TOO
FAR WITH MINS FROM 10 TO 15 INLAND TO AROUND 20 NEAR LAKE SUPERIOR
WHERE DOWNSLOPE FLOW PREVAILS. THE SW WINDS OFF OF LAKE MI WITH 900
MB TEMPS AROUND -10C WILL SUPPORT A BAND OF CLOUDS AND SOME FLURRIES
BUT SHOULD REMAIN TO THE SE OF THE CWA OR JUST CLIP FAR SE LUCE
COUNTY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM EST MON JAN 4 2016
NO SIGNIFICANT WEATHER FOR TUE...BUT A SHORTWAVE WILL MOVE ACROSS
HUDSON BAY TUE INTO TUE NIGHT...DROPPING A SFC TROUGH/FRONT INTO THE
CWA WHERE IT WILL STALL INTO LATE WEEK UNTIL ANOTHER SYSTEM MOVES
THROUGH. COLDER AIR AND WSW WINDS MAY LEAD TO SOME LIGHT LES OVER
MAINLY THE KEWEENAW TUE NIGHT INTO WED MORNING. A WEAK SHORTWAVE
LOOKS TO MOVE ALONG THE FRONT WED NIGHT INTO THU MORNING...WHICH
WILL RESULT IN ADDITIONAL FORCING FOR WIDESPREAD LIGHT TO LOCALLY
MODERATE SNOW. AT THIS TIME...IT LOOKS LIKE THE MODERATE SNOW WILL
FALL OVER LAKE SUPERIOR OR TO THE NW OF THE CWA...BUT RUN TO RUN
CONTINUITY IS NOT GREAT WITH THE SYSTEM WHICH IS EXPECTED AT THAT
TIME FRAME WITH THIS TIME OF SETUP. THINK MOST OR ALL AREAS OF UPPER
MI WILL SEE SUB-ADVISORY AMOUNTS...BUT IF THE BETTER BAND OF SNOW
MOVES OVER WE WOULD PROBABLY SEE ADVISORY AMOUNTS. MAIN TIME FRAME
FOR THE WIDESPREAD SNOW IS WED EVENING INTO THU MORNING.
COULD SEE SOME DRIZZLE/FREEZING DRIZZLE WITH UPSLOPE OVER THE
KEWEENAW AFTER THE SYSTEM SNOW MOVES OUT THU AND AHEAD OF THE NEXT
SYSTEM...BUT THAT IS LOW CHANCE AND LOW CONFIDENCE SO WILL CONTINUE
TO JUST KEEP IT SNOW SHOWERS.
LOTS OF UNCERTAINTY WITH A LATE WEEK INTO THE WEEKEND SYSTEM AS
MODELS HAVE DISAGREEMENT AND RUN TO RUN DISCONTINUITY. MODELS SHOW A
SERIES OF SHORTWAVES LEADING TO A BROAD UPPER TROUGH AND SFC LOW.
SHOULD SEE LIGHT SNOW MOVE IN THU NIGHT/FRI MORNING...POSSIBLY
MIXING WITH OR TURNING TO RAIN OVER MAINLY SOUTHEASTERN UPPER MI FRI
EVENING INTO FRI NIGHT...BUT MODELS HAVE TRENDED COLDER IN THE
LATEST RUNS. PRECIP THEN TURNS BACK TO ALL LIGHT SNOW AND PERSISTS
THROUGH SAT. NOT LOOKING AT ANY SIGNIFICANT SNOWFALL RATES...BUT
IT DOES LOOK LIKE PERSISTENT LIGHT SNOWFALL FOR AROUND 36 HOURS.
SAT NIGHT AND SUN ARE QUITE UNCERTAIN IN EXACT DETAILS...BUT ANOTHER
SHORTWAVE DIVING INTO THE REGION LOOKS TO BRING MUCH COLDER AIR
(POSSIBLY THE COLDEST OF THE SEASON)...SO AT LEAST NW WIND LAKE
EFFECT APPEARS PROBABLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1221 AM EST MON JAN 4 2016
STRONG SUBSIDENCE BEHIND A DEPARTING SHRTWV/LO PRES TROF WL CAUSE
THE INTENSITY OF ONGOING LES TO DIMINISH THRU THIS MRNG. THE MOST
PERSISTENT SHSN WL IMPACT SAW...WHERE UPSLOPE NNE WIND AND
CLOSER PROXIMITY TO COLDER AIR WL RESULT IN MORE PERSISTENT IFR
VSBYS/MVFR CIGS INTO LATE THIS MRNG. AT CMX/IWD...LESS FVRBL NNE WIND
WL BRING FEWER -SHSN AND EVEN VFR CONDITIONS AT TIMES. STRONG
SUBSIDENCE ASSOCIATED WITH HI PRES BLDG INTO THE AREA WL BRING VFR
CONDITIONS TO ALL THE TAF SITES THIS AFTN AND EVNG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EST MON JAN 4 2016
HIGH PRESSURE WILL QUICKLY BUILD ACROSS THE LAKE THIS MORNING AND
THEN QUICKLY MOVE SOUTH OF THE AREA THIS AFTERNOON. BEHIND THE
HIGH...SOUTHWEST WINDS WILL INCREASE TO GALES FORCE TONIGHT INTO TUE
EVENING AHEAD OF THE NEXT FROTNAL SYSTEM. THE GALE WATCH WAS UPGRADED
TO A WARNING FOR THIS PERIOD. THE FRONT STALLS OUT NEAR LAKE SUPERIOR
FOR WED-FRI...LEADING TO WINDS GENERALLY LESS THAN 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ005.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ006.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TUESDAY TO 1 AM EST WEDNESDAY FOR
LSZ265>267.
GALE WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 10 PM EST
/9 PM CST/ TUESDAY FOR LSZ162.
GALE WARNING FROM 10 PM THIS EVENING TO 1 AM EST WEDNESDAY FOR
LSZ263-264.
LAKE MICHIGAN...
GALE WATCH FROM TUESDAY MORNING THROUGH LATE TUESDAY NIGHT FOR
LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
509 AM EST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EST MON JAN 4 2016
WV IMAGERY AND RAP ANALYSIS INDICATED NRLY MID/UPPER LEVEL FLOW
THROUGH THE WRN LAKES BTWN A RIDGE OVER THE PLAINS AND A TROUGH FROM
QUEBEC INTO THE ERN LAKES. STRONG 700-300 MB QVECTOR DIV AND
RESULTING SUBSIDENCE FROM NRN ONTARIO THROUGH LAKE SUPERIOR AND
UPPER MI HAS BROUGHT A DIMINISHING TREND TO THE LES AS THE SHRTWV
THAT MOVED THROUGH LAKE SUPERIOR SUN EVENING MOVES INTO THE ERN
LAKES. ALTHOUGH INVERSION HEIGHTS HAVE DROPPED TO AROUND 4K
FT...INSTABILITY ASSOCIATED WITH 850 MB TEMPS NEAR -18C STILL
SUPPORTED SCT/NMRS LIGHT SNOW SHOWERS IN THE NNE LOW LEVEL FLOW.
TODAY...MID LEVEL AND SFC RIDGING WILL BUILD INTO THE WRN LAKES
TODAY BRINGING AN END TO THE LES THIS MORNING AS INVERSION HEIGHTS
DROP BLO 3K FT AND WINDS BECOME VARIABLE BY MIDDAY. THERE MAY STILL
BE SOME MINOR ADDITIONAL ACCUMULATIONS N CNTRL OF A HALF INCH OR LESS
AFTER 12Z. SW WINDS THIS AFTERNOON WILL HELP BRING SOME
CLEARING. EVEN WITH SOME AFTERNOON SUN...TEMPS WILL REMAIN AT OR
BELOW NORMAL WITH HIGHS AROUND 20. THE COLDEST AIR WILL REMAINED
ENTRENCHED OVER THE EAST NEAR KERY WHERE MAX READINGS REMAIN BLO 15.
TONIGHT...SW WINDS WILL INCREASE AS THE GRADIENT TIGHTENS BETWEEN
THE DEPARTING HIGH AND A TROUGH INTO THE NRN PLAINS. BOUNDARY LAYER
WINDS IN THE 10-20 KNOT RANGE WILL KEEP TEMPS FROM DROPPING OFF TOO
FAR WITH MINS FROM 10 TO 15 INLAND TO AROUND 20 NEAR LAKE SUPERIOR
WHERE DOWNSLOPE FLOW PREVAILS. THE SW WINDS OFF OF LAKE MI WITH 900
MB TEMPS AROUND -10C WILL SUPPORT A BAND OF CLOUDS AND SOME FLURRIES
BUT SHOULD REMAIN TO THE SE OF THE CWA OR JUST CLIP FAR SE LUCE
COUNTY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM EST MON JAN 4 2016
NO SIGNIFICANT WEATHER FOR TUE...BUT A SHORTWAVE WILL MOVE ACROSS
HUDSON BAY TUE INTO TUE NIGHT...DROPPING A SFC TROUGH/FRONT INTO THE
CWA WHERE IT WILL STALL INTO LATE WEEK UNTIL ANOTHER SYSTEM MOVES
THROUGH. COLDER AIR AND WSW WINDS MAY LEAD TO SOME LIGHT LES OVER
MAINLY THE KEWEENAW TUE NIGHT INTO WED MORNING. A WEAK SHORTWAVE
LOOKS TO MOVE ALONG THE FRONT WED NIGHT INTO THU MORNING...WHICH
WILL RESULT IN ADDITIONAL FORCING FOR WIDESPREAD LIGHT TO LOCALLY
MODERATE SNOW. AT THIS TIME...IT LOOKS LIKE THE MODERATE SNOW WILL
FALL OVER LAKE SUPERIOR OR TO THE NW OF THE CWA...BUT RUN TO RUN
CONTINUITY IS NOT GREAT WITH THE SYSTEM WHICH IS EXPECTED AT THAT
TIME FRAME WITH THIS TIME OF SETUP. THINK MOST OR ALL AREAS OF UPPER
MI WILL SEE SUB-ADVISORY AMOUNTS...BUT IF THE BETTER BAND OF SNOW
MOVES OVER WE WOULD PROBABLY SEE ADVISORY AMOUNTS. MAIN TIME FRAME
FOR THE WIDESPREAD SNOW IS WED EVENING INTO THU MORNING.
COULD SEE SOME DRIZZLE/FREEZING DRIZZLE WITH UPSLOPE OVER THE
KEWEENAW AFTER THE SYSTEM SNOW MOVES OUT THU AND AHEAD OF THE NEXT
SYSTEM...BUT THAT IS LOW CHANCE AND LOW CONFIDENCE SO WILL CONTINUE
TO JUST KEEP IT SNOW SHOWERS.
LOTS OF UNCERTAINTY WITH A LATE WEEK INTO THE WEEKEND SYSTEM AS
MODELS HAVE DISAGREEMENT AND RUN TO RUN DISCONTINUITY. MODELS SHOW A
SERIES OF SHORTWAVES LEADING TO A BROAD UPPER TROUGH AND SFC LOW.
SHOULD SEE LIGHT SNOW MOVE IN THU NIGHT/FRI MORNING...POSSIBLY
MIXING WITH OR TURNING TO RAIN OVER MAINLY SOUTHEASTERN UPPER MI FRI
EVENING INTO FRI NIGHT...BUT MODELS HAVE TRENDED COLDER IN THE
LATEST RUNS. PRECIP THEN TURNS BACK TO ALL LIGHT SNOW AND PERSISTS
THROUGH SAT. NOT LOOKING AT ANY SIGNIFICANT SNOWFALL RATES...BUT
IT DOES LOOK LIKE PERSISTENT LIGHT SNOWFALL FOR AROUND 36 HOURS.
SAT NIGHT AND SUN ARE QUITE UNCERTAIN IN EXACT DETAILS...BUT ANOTHER
SHORTWAVE DIVING INTO THE REGION LOOKS TO BRING MUCH COLDER AIR
(POSSIBLY THE COLDEST OF THE SEASON)...SO AT LEAST NW WIND LAKE
EFFECT APPEARS PROBABLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1221 AM EST MON JAN 4 2016
STRONG SUBSIDENCE BEHIND A DEPARTING SHRTWV/LO PRES TROF WL CAUSE
THE INTENSITY OF ONGOING LES TO DIMINISH THRU THIS MRNG. THE MOST
PERSISTENT SHSN WL IMPACT SAW...WHERE UPSLOPE NNE WIND AND
CLOSER PROXIMITY TO COLDER AIR WL RESULT IN MORE PERSISTENT IFR
VSBYS/MVFR CIGS INTO LATE THIS MRNG. AT CMX/IWD...LESS FVRBL NNE WIND
WL BRING FEWER -SHSN AND EVEN VFR CONDITIONS AT TIMES. STRONG
SUBSIDENCE ASSOCIATED WITH HI PRES BLDG INTO THE AREA WL BRING VFR
CONDITIONS TO ALL THE TAF SITES THIS AFTN AND EVNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 335 PM EST SUN JAN 3 2016 EXPECT NORTH TO NORTHWEST WINDS TO 30KT TO BACK TO N-NE
TONIGHT BEHIND A TROUGH OF LOW PRESSURE THIS EVENING. HIGH PRESSURE
WILL QUICKLY BUILD ACROSS THE LAKE LATE TONIGHT. THIS HIGH QUICKLY
MOVES SOUTH OF THE AREA MONDAY AFTERNOON. BEHIND THE
HIGH...SOUTHWEST WINDS WILL INCREASE TO NEAR GALE FORCE MON NIGHT
INTO TUE AHEAD OF THE NEXT FROTNAL SYSTEM. WILL ISSUE A GALE WATCH
FOR THIS TIME PERIOD ACROSS THE LAKE. THE FRONT STALLS OUT NEAR LAKE
SUPERIOR FOR WED-FRI...LEADING TO WIND GENERALLY LESS THAN 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ005.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ006.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TUESDAY TO 1 AM EST WEDNESDAY FOR
LSZ265>267.
GALE WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 10 PM EST
/9 PM CST/ TUESDAY FOR LSZ162.
GALE WARNING FROM 10 PM THIS EVENING TO 1 AM EST WEDNESDAY FOR
LSZ263-264.
LAKE MICHIGAN...
GALE WATCH FROM TUESDAY MORNING THROUGH LATE TUESDAY NIGHT FOR
LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...MRD
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
553 AM CST MON JAN 4 2016
.DISCUSSION...
Issued at 331 AM CST MON JAN 4 2016
Stratus will continue to impact the region today and possibly into
tonight as moisture continues to pool and advect across the northern
and eastern Plains. NAM and RAP indicate stratus holding strong
through the day and possibly even retrograding slightly to the west,
and thus have lowered temperatures another degree or two for today,
and raised low temperatures a few degrees for tonight.
The main concern in the forecast remains the potential for some wet
weather during the latter half of the work week, possibly starting
out as light freezing drizzle early Wednesday morning just ahead of
the surface warm front. Synoptically, the broad western trough is
still expected to push developing surface low pressure eastward
across the forecast area on Friday, and isentropic lift/moisture
advection will support periods of light rain Wednesday through
Friday as the system ejects out. Temperatures will warm above the
freezing mark mid-morning Wednesday and remain there through
Saturday, keeping precipitation type all rain once the surface warm
front passes through the CWA. Precipitation will be very light until
saturation deepens and forcing improves Thursday evening, then a
half inch or perhaps a little more rainfall is possible through late
Friday just ahead of and in the vicinity of the surface low. A brief
mix with or changeover to snow is also still possible on the back
side of the system Saturday, but moisture should be limited enough
and the speed of the system fast enough to prevent much, if any,
snow accumulation.
Much colder temperatures are expected behind this system and
especially early next week when all model solutions show a deepening
trough digging into the Great Lakes region and allowing -25 to -30 C
850 mb temperatures to surge southward into the Midwest. Started the
trend of lowering both highs and lows from Saturday night through
the end of the forecast period, and will likely have to continue to
do so until model blends start to pick up on the anomalous pattern
early next week. Highs will likely top out in the teens or even the
upper single digits by the beginning of the next work week, and lows
could possibly fall below zero near the IA/MO border if the cold air
arrives as progged. Enough dry air accompanies this system to
prevent any decent potential for precipitation, so have kept the
forecast dry beyond this weekend`s system and do not anticipate
any wintry precipitation as the cold air arrives.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday Morning)
Issued at 553 AM CST MON JAN 4 2016
IFR to low-end MVFR stratus will continue to sit over all TAF sites
today, and could persist into the early overnight hours before
gradually diminishing. Ceilings may lift a few hundred feet during
the day, but will likely waver right around 1000 ft. Winds will
progressively veer from northeast to southeast, at speeds less than
10 kts.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Laflin
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
535 AM CST MON JAN 4 2016
.SHORT TERM: (Today and Tonight)
Issued at 330 AM CST Mon Jan 4 2016
The large high pressure system currently centered near the NE/IA
border will be the dominant weather feature today. Biggest
challenge will be stratus trapped within southeastern quadrant of
the high. The models are in good agreement that the center of the
high will slide to the north today which will lead to veering of
the low level winds from north to northeast. This pattern should
allow erosion/clearing from the northeast, beginning over west-
central and south central IL, with the stratus field pivoting to
a slightly more N/S orientation. Based on this scenario and RH
progs from the RAP and NAM, locations west of the MS River should
clear last. I currently have this occuring late afternoon and that
may be a tad fast. Continued veering of the low level winds to a
more southerly component will occur tonight as the high retreats,
which should promote remaining clouds to be advected to the
northwest. Another seasonably cold day and night is expected.
Glass
.LONG TERM: (Tuesday through Sunday)
Issued at 330 AM CST Mon Jan 4 2016
A progressive flow regime will continue to mature with a ridge
aloft overhead early Tuesday, dampening and moving east on
Tuesday night. The accompanying retreat of the low level
anticyclone will bring veering southeast-southwest lower trop flow
and pronounced WAA, and hence warmer temperatures. More active
southwest flow aloft ensues Wednesday through late Friday as a
broad longwave trof shifts eastward in response to several well-
defined migratory short waves. Weak large scale ascent and low
level WAA associated wth the first of these waves will result in
slight chance pops Wednesday afternoon for parts of central MO,
increasing to chance pops Wednesday night. I haven`t mentioned it
in the forecast due to the low probability, but there could be a
brief period of sleet or a rain/sleet mix at the onset of
precipitation due to evaporative cooling, however WAA will
utlimately win out.
Rain chances will ramp up Thursday/Thursday Night due to stronger
forcing/lift associated with the next more potent migratory short
wave trof.
Glass
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 529 AM CST Mon Jan 4 2016
Similar to yesterday...primary aviation concern will be on
evolution of stratus. Currently...borderline MVFR/low VFR stratus
covers most of the bi- state area. Slow advection of the deck to
the south/southwest with time may bring in some clearing to KUIN
and the metro TAF sites later today. However...am expecting SCT-
BKN stratocu development in its wake during the day. This should
diminish though with loss of daytime heating leaving KUIN and
metro TAF sites by and large free of clouds. KCOU should have more
consistent stratus during the day today and could hold onto it
much of the night as the low- level winds veer from the north this
morning all the way to a more southerly direction by tonight
around the periphery of the sfc high retreating into the Ohio
Valley.
Specifics for KSTL:
Stratus continues to impact the terminal. Ceiling should lift to
VFR late this morning and could scatter out for a few hours before
diurnal stratocu development fills in. The stratocu then should
fade this evening leaving a mostly clear sky. Sfc winds will start
off north/northeasterly this morning and veer to the southeast by
late tonight. Winds however should stay aob 10 knots.
Gosselin
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 34 23 41 27 / 0 0 0 5
Quincy 32 21 37 25 / 0 0 0 0
Columbia 33 21 41 26 / 0 0 0 5
Jefferson City 36 21 43 26 / 0 0 0 5
Salem 35 23 39 27 / 0 0 0 5
Farmington 34 21 39 26 / 0 0 0 5
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
612 AM CST MON JAN 4 2016
.UPDATE...
ISSUED AT 608 AM CST MON JAN 4 2016
DID A QUICK UPDATE TO HIT THE FOG A LITTLE HARDER IN A CURVED
NARROW CORRIDOR ON THE WEST EDGE OF THE SLOWLY EAST-PROGRESSING
STRATUS INTRUSION THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CST MON JAN 4 2016
SATELLITE AND OBSERVATIONS SHOW STRATUS AND FOG ACROSS EASTERN
NEBRASKA AND KANSAS THAT IS MOVING TO THE WEST TONIGHT. AHEAD OF THE
STRATUS VISIBILITIES HAVE BEEN DROPPING AND A FEW LOCATIONS HAVE
DROPPED BELOW A HALF MILE. LOOKING AT WEBCAMS AROUND THE AREA THE
VISIBILITY APPEARS TO VARY GREATLY FROM LOCATION TO LOCATION.
AS THE STRATUS MOVES TO THE WEST EXPECT THE FOG ON THE EDGE OF THE
STRATUS TO ALSO MOVE TO THE WEST. THE HRRR HAS SOME FOG SPREADING
INTO THE FORECAST AREA...BUT THE FOG IS SPREADING A LITTLE FASTER
THAN THE LATEST RUN. BASED ON THE LOCATION OF THE LOWER VISIBILITY
FROM THE HRRR THE WORST OF THE FOG SHOULD BE IN THE EASTERN HALF TO
TWO THIRDS...MAINLY ALONG AND EAST OF HIGHWAY 183. HAVE KEPT SOME
FOG IN THE WEST...BUT HAVE THE WORSE CONDITIONS FURTHER TO THE EAST.
SO THE NEXT QUESTION BECOMES WHEN WILL THE VISIBILITY IMPROVE? THE
HRRR KEEPS VISIBILITY LOWER THROUGH THE MORNING HOURS AND EAST OF
HIGHWAY 281 AND NORTH OF HIGHWAY 6 COULD LINGER THROUGH MUCH OF THE
DAYTIME HOURS. HAVE KEPT SOME FOG THROUGH THE MORNING HOURS THEN
MOSTLY CLOUDY SKIES THROUGH THE AFTERNOON.
THE SURFACE HIGH CENTERED OVER WESTERN IOWA EARLY THIS MORNING IS
EXPECTED TO MOVE TO THE EAST. THE PRESSURE GRADIENT WILL TIGHTEN FOR
TODAY AND TONIGHT. THROUGH THE DAYTIME THE WINDS ALOFT ARE ONLY 10
TO 20 KTS SO NOT EXPECTING WINDS TO INCREASE MUCH...BUT THEY SHOULD
TURN TO THE SOUTH INSTEAD OF FROM THE EAST AS THEY ARE EARLY THIS
MORNING. THIS SHOULD HELP THE FOG BECOME LESS OF A CONCERN FOR LATER
THIS MORNING AND INTO THE AFTERNOON.
THE PRESSURE GRADIENT CONTINUES TO BE FAIRLY TIGHT TONIGHT AND WINDS
ALOFT INCREASE TO AROUND 45KTS. WINDS WILL NOT BE STRONG
TONIGHT...BUT THEY WILL INCREASE TO THE 10 TO 20 MPH RANGE AND FOG
SHOULD NOT FORM TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 516 AM CST MON JAN 4 2016
THIS CONTINUES TO BE A CHALLENGING LONG TERM...ESPECIALLY REGARDING
A POTENTIAL FOR SNOW TOWARD MID-LATE WEEK.
KICKING OFF WITH TUESDAY...I ACTUALLY RAISED TEMPERATURE A BIT FOR
TUESDAY HIGHS WITH THE EXPECTED WARM AIR ADVECTION AND REDUCED SNOW
COVER...ALTHOUGH I EXPECT PLENTY OF CLOUDS...SO NOT GOING TO CRAZY
HERE WITH HIGHS GENERALLY NEAR 40 TO THE MID 40S. FOG MAY BE A
CONCERN FOR AT LEAST A COUPLE OF MORNINGS...AS MELTING SNOW MAY PLAY
A PART IN THIS. I DID NOT ADD ANY...BUT THE POTENTIAL IS THERE.
A SHORTWAVE TROUGH OR PERHAPS A SERIES OF TROUGHS ARE FORECAST TO
KICK OUT OF THE SOUTHERN ROCKIES INTO OUR AREA BY THE WEDNESDAY
THROUGH FRIDAY TIME FRAME. MODELS DEFINITELY VARY WITH PLACEMENT AND
TIMING...SO ANY POTENTIAL SNOWFALL AMOUNTS ARE TOUGH. IT APPEARS
THAT THE BEST SHOT AT PRECIPITATION WILL BE THE THURSDAY/THURSDAY
NIGHT TIME FRAME. ONE THING APPEARS CERTAIN...WE SHOULD SEE A STEADY
DECLINE OF HIGH TEMPERATURES FOR THE REST OF THE LONG TERM AS A MEAN
TROUGH DEVELOPS FOR THE WESTERN HALF OF THE COUNTRY AND INTRODUCES
QUITE POSSIBLY THE COLDEST AIR OF THE YEAR SO FAR. BY SUNDAY...IT
WILL PROBABLY BE A STRUGGLE TO MAKE IT INTO THE 20S...AND JUST
OUTSIDE THE SCOPE OF THE LONG TERM ON MONDAY NEXT WEEK...I WOULD NOT
BE SURPRISED IF WE DID NOT MANAGE TO BREAK OUT OF THE TEENS FOR
HIGHS. WE WILL BE FAR ENOUGH INTO THE COLD AIR THAT CONSRAW SEEMS TO
BE PICKING UP ON THE COLD AIR BETTER THAN ANYTHING ELSE...AT LEAST
FOR HIGH TEMPERATURES.
FORECAST SOUNDINGS INDICATE A POTENTIAL FOR SOME FREEZING DRIZZLE IN
OUR SOUTHEAST AS WE START GETTING SOME SIGNALS FOR THE
DRIZZLE/FREEZING DRIZZLE. BY THE TIME LIGHT PRECIPITATION MAY
SPREADS FARTHER NORTH...I SUSPECT SURFACE TEMPERATURES TO WARM ABOVE
FREEZING AND WE COULD EVEN FURTHER SATURATE MID AND UPPER
LEVELS...SO I KEPT ANY FREEZING DRIZZLE MENTIONED TO LATE TUESDAY
NIGHT AND EARLY WEDNESDAY FOR FAR SOUTHEASTERN PARTS OF THE CWA.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 518 AM CST MON JAN 4 2016
FOG AND LOW CLOUDS WILL PERSIST FOR THE MORNING HOURS. KGRI WILL
HAVE WORSE CONDITIONS THAN KEAR. THE WESTWARD MOVEMENT OF THE
STRATUS AND FOG HAS SLOWED DOWN A LITTLE. EXPECT THAT BY MID DAY
THE LOW CLOUDS AND FOG WILL LIFT. THERE IS A SMALL CHANCE THAT
THIS COULD LINGER INTO THE AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
526 AM CST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CST MON JAN 4 2016
SATELLITE AND OBSERVATIONS SHOW STRATUS AND FOG ACROSS EASTERN
NEBRASKA AND KANSAS THAT IS MOVING TO THE WEST TONIGHT. AHEAD OF THE
STRATUS VISIBILITIES HAVE BEEN DROPPING AND A FEW LOCATIONS HAVE
DROPPED BELOW A HALF MILE. LOOKING AT WEBCAMS AROUND THE AREA THE
VISIBILITY APPEARS TO VARY GREATLY FROM LOCATION TO LOCATION.
AS THE STRATUS MOVES TO THE WEST EXPECT THE FOG ON THE EDGE OF THE
STRATUS TO ALSO MOVE TO THE WEST. THE HRRR HAS SOME FOG SPREADING
INTO THE FORECAST AREA...BUT THE FOG IS SPREADING A LITTLE FASTER
THAN THE LATEST RUN. BASED ON THE LOCATION OF THE LOWER VISIBILITY
FROM THE HRRR THE WORST OF THE FOG SHOULD BE IN THE EASTERN HALF TO
TWO THIRDS...MAINLY ALONG AND EAST OF HIGHWAY 183. HAVE KEPT SOME
FOG IN THE WEST...BUT HAVE THE WORSE CONDITIONS FURTHER TO THE EAST.
SO THE NEXT QUESTION BECOMES WHEN WILL THE VISIBILITY IMPROVE? THE
HRRR KEEPS VISIBILITY LOWER THROUGH THE MORNING HOURS AND EAST OF
HIGHWAY 281 AND NORTH OF HIGHWAY 6 COULD LINGER THROUGH MUCH OF THE
DAYTIME HOURS. HAVE KEPT SOME FOG THROUGH THE MORNING HOURS THEN
MOSTLY CLOUDY SKIES THROUGH THE AFTERNOON.
THE SURFACE HIGH CENTERED OVER WESTERN IOWA EARLY THIS MORNING IS
EXPECTED TO MOVE TO THE EAST. THE PRESSURE GRADIENT WILL TIGHTEN FOR
TODAY AND TONIGHT. THROUGH THE DAYTIME THE WINDS ALOFT ARE ONLY 10
TO 20 KTS SO NOT EXPECTING WINDS TO INCREASE MUCH...BUT THEY SHOULD
TURN TO THE SOUTH INSTEAD OF FROM THE EAST AS THEY ARE EARLY THIS
MORNING. THIS SHOULD HELP THE FOG BECOME LESS OF A CONCERN FOR LATER
THIS MORNING AND INTO THE AFTERNOON.
THE PRESSURE GRADIENT CONTINUES TO BE FAIRLY TIGHT TONIGHT AND WINDS
ALOFT INCREASE TO AROUND 45KTS. WINDS WILL NOT BE STRONG
TONIGHT...BUT THEY WILL INCREASE TO THE 10 TO 20 MPH RANGE AND FOG
SHOULD NOT FORM TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 516 AM CST MON JAN 4 2016
THIS CONTINUES TO BE A CHALLENGING LONG TERM...ESPECIALLY REGARDING
A POTENTIAL FOR SNOW TOWARD MID-LATE WEEK.
KICKING OFF WITH TUESDAY...I ACTUALLY RAISED TEMPERATURE A BIT FOR
TUESDAY HIGHS WITH THE EXPECTED WARM AIR ADVECTION AND REDUCED SNOW
COVER...ALTHOUGH I EXPECT PLENTY OF CLOUDS...SO NOT GOING TO CRAZY
HERE WITH HIGHS GENERALLY NEAR 40 TO THE MID 40S. FOG MAY BE A
CONCERN FOR AT LEAST A COUPLE OF MORNINGS...AS MELTING SNOW MAY PLAY
A PART IN THIS. I DID NOT ADD ANY...BUT THE POTENTIAL IS THERE.
A SHORTWAVE TROUGH OR PERHAPS A SERIES OF TROUGHS ARE FORECAST TO
KICK OUT OF THE SOUTHERN ROCKIES INTO OUR AREA BY THE WEDNESDAY
THROUGH FRIDAY TIME FRAME. MODELS DEFINITELY VARY WITH PLACEMENT AND
TIMING...SO ANY POTENTIAL SNOWFALL AMOUNTS ARE TOUGH. IT APPEARS
THAT THE BEST SHOT AT PRECIPITATION WILL BE THE THURSDAY/THURSDAY
NIGHT TIME FRAME. ONE THING APPEARS CERTAIN...WE SHOULD SEE A STEADY
DECLINE OF HIGH TEMPERATURES FOR THE REST OF THE LONG TERM AS A MEAN
TROUGH DEVELOPS FOR THE WESTERN HALF OF THE COUNTRY AND INTRODUCES
QUITE POSSIBLY THE COLDEST AIR OF THE YEAR SO FAR. BY SUNDAY...IT
WILL PROBABLY BE A STRUGGLE TO MAKE IT INTO THE 20S...AND JUST
OUTSIDE THE SCOPE OF THE LONG TERM ON MONDAY NEXT WEEK...I WOULD NOT
BE SURPRISED IF WE DID NOT MANAGE TO BREAK OUT OF THE TEENS FOR
HIGHS. WE WILL BE FAR ENOUGH INTO THE COLD AIR THAT CONSRAW SEEMS TO
BE PICKING UP ON THE COLD AIR BETTER THAN ANYTHING ELSE...AT LEAST
FOR HIGH TEMPERATURES.
FORECAST SOUNDINGS INDICATE A POTENTIAL FOR SOME FREEZING DRIZZLE IN
OUR SOUTHEAST AS WE START GETTING SOME SIGNALS FOR THE
DRIZZLE/FREEZING DRIZZLE. BY THE TIME LIGHT PRECIPITATION MAY
SPREADS FARTHER NORTH...I SUSPECT SURFACE TEMPERATURES TO WARM ABOVE
FREEZING AND WE COULD EVEN FURTHER SATURATE MID AND UPPER
LEVELS...SO I KEPT ANY FREEZING DRIZZLE MENTIONED TO LATE TUESDAY
NIGHT AND EARLY WEDNESDAY FOR FAR SOUTHEASTERN PARTS OF THE CWA.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 518 AM CST MON JAN 4 2016
FOG AND LOW CLOUDS WILL PERSIST FOR THE MORNING HOURS. KGRI WILL
HAVE WORSE CONDITIONS THAN KEAR. THE WESTWARD MOVEMENT OF THE
STRATUS AND FOG HAS SLOWED DOWN A LITTLE. EXPECT THAT BY MID DAY
THE LOW CLOUDS AND FOG WILL LIFT. THERE IS A SMALL CHANCE THAT
THIS COULD LINGER INTO THE AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
517 AM CST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CST MON JAN 4 2016
SATELLITE AND OBSERVATIONS SHOW STRATUS AND FOG ACROSS EASTERN
NEBRASKA AND KANSAS THAT IS MOVING TO THE WEST TONIGHT. AHEAD OF THE
STRATUS VISIBILITIES HAVE BEEN DROPPING AND A FEW LOCATIONS HAVE
DROPPED BELOW A HALF MILE. LOOKING AT WEBCAMS AROUND THE AREA THE
VISIBILITY APPEARS TO VARY GREATLY FROM LOCATION TO LOCATION.
AS THE STRATUS MOVES TO THE WEST EXPECT THE FOG ON THE EDGE OF THE
STRATUS TO ALSO MOVE TO THE WEST. THE HRRR HAS SOME FOG SPREADING
INTO THE FORECAST AREA...BUT THE FOG IS SPREADING A LITTLE FASTER
THAN THE LATEST RUN. BASED ON THE LOCATION OF THE LOWER VISIBILITY
FROM THE HRRR THE WORST OF THE FOG SHOULD BE IN THE EASTERN HALF TO
TWO THIRDS...MAINLY ALONG AND EAST OF HIGHWAY 183. HAVE KEPT SOME
FOG IN THE WEST...BUT HAVE THE WORSE CONDITIONS FURTHER TO THE EAST.
SO THE NEXT QUESTION BECOMES WHEN WILL THE VISIBILITY IMPROVE? THE
HRRR KEEPS VISIBILITY LOWER THROUGH THE MORNING HOURS AND EAST OF
HIGHWAY 281 AND NORTH OF HIGHWAY 6 COULD LINGER THROUGH MUCH OF THE
DAYTIME HOURS. HAVE KEPT SOME FOG THROUGH THE MORNING HOURS THEN
MOSTLY CLOUDY SKIES THROUGH THE AFTERNOON.
THE SURFACE HIGH CENTERED OVER WESTERN IOWA EARLY THIS MORNING IS
EXPECTED TO MOVE TO THE EAST. THE PRESSURE GRADIENT WILL TIGHTEN FOR
TODAY AND TONIGHT. THROUGH THE DAYTIME THE WINDS ALOFT ARE ONLY 10
TO 20 KTS SO NOT EXPECTING WINDS TO INCREASE MUCH...BUT THEY SHOULD
TURN TO THE SOUTH INSTEAD OF FROM THE EAST AS THEY ARE EARLY THIS
MORNING. THIS SHOULD HELP THE FOG BECOME LESS OF A CONCERN FOR LATER
THIS MORNING AND INTO THE AFTERNOON.
THE PRESSURE GRADIENT CONTINUES TO BE FAIRLY TIGHT TONIGHT AND WINDS
ALOFT INCREASE TO AROUND 45KTS. WINDS WILL NOT BE STRONG
TONIGHT...BUT THEY WILL INCREASE TO THE 10 TO 20 MPH RANGE AND FOG
SHOULD NOT FORM TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 516 AM CST MON JAN 4 2016
THIS CONTINUES TO BE A CHALLENGING LONG TERM...ESPECIALLY REGARDING
A POTENTIAL FOR SNOW TOWARD MID-LATE WEEK.
KICKING OFF WITH TUESDAY...I ACTUALLY RAISED TEMPERATURE A BIT FOR
TUESDAY HIGHS WITH THE EXPECTED WARM AIR ADVECTION AND REDUCED SNOW
COVER...ALTHOUGH I EXPECT PLENTY OF CLOUDS...SO NOT GOING TO CRAZY
HERE WITH HIGHS GENERALLY NEAR 40 TO THE MID 40S. FOG MAY BE A
CONCERN FOR AT LEAST A COUPLE OF MORNINGS...AS MELTING SNOW MAY PLAY
A PART IN THIS. I DID NOT ADD ANY...BUT THE POTENTIAL IS THERE.
A SHORTWAVE TROUGH OR PERHAPS A SERIES OF TROUGHS ARE FORECAST TO
KICK OUT OF THE SOUTHERN ROCKIES INTO OUR AREA BY THE WEDNESDAY
THROUGH FRIDAY TIME FRAME. MODELS DEFINITELY VARY WITH PLACEMENT AND
TIMING...SO ANY POTENTIAL SNOWFALL AMOUNTS ARE TOUGH. IT APPEARS
THAT THE BEST SHOT AT PRECIPITATION WILL BE THE THURSDAY/THURSDAY
NIGHT TIME FRAME. ONE THING APPEARS CERTAIN...WE SHOULD SEE A STEADY
DECLINE OF HIGH TEMPERATURES FOR THE REST OF THE LONG TERM AS A MEAN
TROUGH DEVELOPS FOR THE WESTERN HALF OF THE COUNTRY AND INTRODUCES
QUITE POSSIBLY THE COLDEST AIR OF THE YEAR SO FAR. BY SUNDAY...IT
WILL PROBABLY BE A STRUGGLE TO MAKE IT INTO THE 20S...AND JUST
OUTSIDE THE SCOPE OF THE LONG TERM ON MONDAY NEXT WEEK...I WOULD NOT
BE SURPRISED IF WE DID NOT MANAGE TO BREAK OUT OF THE TEENS FOR
HIGHS. WE WILL BE FAR ENOUGH INTO THE COLD AIR THAT CONSRAW SEEMS TO
BE PICKING UP ON THE COLD AIR BETTER THAN ANYTHING ELSE...AT LEAST
FOR HIGH TEMPERATURES.
FORECAST SOUNDINGS INDICATE A POTENTIAL FOR SOME FREEZING DRIZZLE IN
OUR SOUTHEAST AS WE START GETTING SOME SIGNALS FOR THE
DRIZZLE/FREEZING DRIZZLE. BY THE TIME LIGHT PRECIPITATION MAY
SPREADS FARTHER NORTH...I SUSPECT SURFACE TEMPERATURES TO WARM ABOVE
FREEZING AND WE COULD EVEN FURTHER SATURATE MID AND UPPER
LEVELS...SO I KEPT ANY FREEZING DRIZZLE MENTIONED TO LATE TUESDAY
NIGHT AND EARLY WEDNESDAY FOR FAR SOUTHEASTERN PARTS OF THE CWA.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1118 PM CST SUN JAN 3 2016
LOW CLOUDS AND FOG/MIST WILL BE THE MAIN CONCERN FOR THE FORECAST
PERIOD. STRATUS IS MOVING TOWARD THE WEST AND WILL APPROACH THE
TERMINALS IN THE NEXT FEW HOURS. THERE WILL BE SOME FOG/MIST THAT
SHOULD REDUCE VISIBILITIES. THE NEXT CONCERN WILL BE HOW LONG IT
WILL HOLD ON IN THE MORNING. HAVE KEPT IT DURING THE MORNING BUT
CLEARED THINGS OUT IN THE AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...JCB
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
516 AM CST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CST MON JAN 4 2016
TODAY AND TONIGHT...THE ARCTIC DRAPE ACROSS ERN NEB SHOULD BE PULLED
WEST INTO THE FCST AREA THIS MORNING AND THEN NORTH DURING THE AFTN.
THE RAP MODEL BOUNDARY LAYER RH PROVIDES A PESSIMISTIC FCST OF
STRATUS APPROACHING HIGHWAY 83 AND SOCKING AREAS EAST ALL DAY. THE
NAM IS MORE MODERATE SUGGESTING MIXING AND SUNSHINE TODAY TO BE
REPLACED BY HIGH CLOUDS IN THE AFTN. THIS APPEARS TO BE SUPPORTED BY
THE GFS AND ECM.
AREAS OF FOG ARE UNDERWAY AS INDICATED IN THE RAP WHICH WOULD MIX
OUT THIS AFTN AS SHOWN BY THE NAM. THE TEMPERATURE FORECAST USES THE
ECS AND MAV GUIDANCE PLUS BIAS CORRECTION FOR HIGHS IN THE 30S TO
AROUND 40. SOUTH WINDS INCREASE TO 10 TO 20 MPH. H850MB TEMPERATURES
RISE TO 2 TO 6C THIS AFTN WHICH COULD PRODUCE HIGHS IN THE 40S
ACROSS ALL AREAS. THE TEMPERATURE FORECAST REPRESENTS A DIFFERENTIAL
BETWEEN THE SOUTH WINDS AND HIGH CLOUDS WHICH LIMIT MIXING VS WARM
AIR ADVECTION.
TONIGHT THE GFS AND NAM INDICATE STRATUS DEVELOPMENT IN A GRADIENT
OF STRONG SOUTHWEST WINDS. THE ECM BUILDS A MESO HIGH ACROSS THE
SANDHILLS ELIMINATING MOISTURE POOLING FOR CLOUD FORMATION. THE
FORECAST FOLLOWS THE GFS AND NAM WITH LOWS IN THE TEENS AND LOWER
20S. SOUTH WINDS CONTINUE AT 10 TO 20 MPH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 342 AM CST MON JAN 4 2016
12Z TUESDAY AND BEYOND. THE MODELS CONTINUE TO ADVERTISE THE
PASSAGE OF A LEAD SHORTWAVE FROM THE SOUTHWEST LATE TUESDAY INTO
WEDNESDAY. THE MODELS SUGGEST INCREASING SYSTEM RELATIVE UPGLIDE
GENERALLY ALONG THE 285-290K SURFACES THAT MAY WORK IN CONJUNCTION
WITH SMALL CONDENSATION PRESSURE DEFICITS TO PRODUCE LIGHT QPF
ACROSS OUR EASTERN ZONES EARLY WEDNESDAY. THE GFS IS LEADING THE
CHARGE WITH SUFFICIENT SATURATION TO PRODUCE A FEW HUNDRETHS
QPF...WHEREAS THE NAM AND THE ECMWF CONFINE MOISTURE IN THE LOWEST
LAYERS OF THE TROPOSPHERE AND GENERALLY FAVOR STRATUS...OR POSSIBLY
LIGHT DZ. WILL MAINTAIN A DRY FORECAST FOR NOW...BUT CONTINUE TO
CLOSELY MONITOR AS THE TIMING OF THE EVENT WOULD FAVOR FROZEN
QPF...EITHER -FZDZ OR -SN. THE SYSTEM AND ANY POTENTIAL QPF IS
SHOWN TO BE EAST OF THE FORECAST AREA BY 00Z THURSDAY. THE WAVE IF
NOTHING ELSE WILL PULL A WEAK BOUNDARY SOUTH ACROSS THE SANDHILLS ON
WEDNESDAY...COOLING TEMPERATURES SLIGHTLY.
ATTENTION TURNS TO THE NEXT PIECE OF ENERGY EJECTING FROM A WESTERN
CONUS MID-LEVEL TROUGH. THE GENERAL IDEA OF THE ECMWF AND GFS IS TO
DEVELOP A CLOSED LOW SOUTH OF THE CWA LATE THURSDAY INTO FRIDAY.
HOWEVER...THE MODELS /ESPECIALLY THE GFS/ HAVE TRENDED SOUTH WITH
THIS FEATURE. CONFIDENCE IS WANING...THUS NO CHANGES WERE MADE TO
THE EXTENDED BLEND PROCEDURE...WHICH ESSENTIALLY PRODUCED SIMILAR
RESULTS FROM THE PREVIOUS FORECAST. THE HIGHER END CHANCE POPS ARE
MAXIMIZED ACROSS OUR SOUTHERN AND EASTERN ZONES...WHICH IS
APPROPRIATE. PTYPE IS UNCERTAIN AT THIS POINT AS THE VARIOUS MODELS
SUGGEST DIFFERING AMOUNT OF SATURATION AND THERMAL PROFILES. LIGHT
FZDZ...-RA...-SN OR -ZR CANNOT BE RULED OUT AT THIS POINT. GIVEN THE
RECENT PATTERN...THE MOST LIKELY PTYPE WILL BE -SN WITH POSSIBLY A
PERIOD OF -FZDZ. MORE CERTAIN IS THAT IN THE WAKE OF THE SYSTEM
COLDER AIR WILL BE DRAWN SOUTH ACROSS THE CENTRAL PLAINS FOR LATE
WEEK AND THE WEEKEND. AS THE ARCTIC HIGH SETS UP RESIDENCE ACROSS
WEST CENTRAL NEBRASKA ON SUNDAY...HIGHS MAY STRUGGLE TO CLIMB OUT OF
THE TEENS WITH AREAS OF SUB 0F LOWS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 516 AM CST MON JAN 4 2016
THE NAM...SREF AND RAP MODELS SUGGEST LOCAL IFR/LIFR VIS IN FOG
IS POSSIBLE ALONG AND EAST OF HIGHWAY 183 THIS MORNING.
MVFR CIGS ARE EXPECTED TONIGHT...GENERALLY ALONG AND EAST OF
HIGHWAY 83. LIFR/IFR IN FOG MAY FORM TONIGHT ALONG AND WEST OF
HIGHWAY 61.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
713 AM EST MON JAN 4 2016
.SYNOPSIS...
NORTHWEST FLOW WILL CONTINUE TO DOMINATE THE PATTERN FOR THE NEXT
COUPLE OF DAYS WITH THE COLDEST AIR OF THE SEASON EXPECTED TO
START THIS FIRST FULL WEEK OF THE NEW YEAR. TEMPERATURES WILL
BEGIN TO MODERATE LATER IN THE WEEK AS HIGH PRESSURE BUILDS
EASTWARD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM THE IS SNOW SHOWERS ARE VERY SMALL...CELLULAR AND
DISORGANIZED...MORE LIKE SCATTERED FLURRIES. THE HRRR AND UCAR
ENSEMBLE SUPPORT ONLY ISOLATED MEASURABLE AMOUNTS AS THE OVER-LAKE
TRAJECTORIES SHORTEN UP AND INVERSION HEIGHTS LOWER RAPIDLY OVER
THE NEXT SEVERAL HOURS. KEPT LOW POPS AND LIMITED AND SNOW
ACCUM COVERAGE GIVEN THE MODEL AND RADAR TRENDS.
THE LAURELS WILL LIKELY SEE A SEVERAL HOUR PERIOD OF SNOW...BUT
WITH VISIBILITIES GENERALLY NO LOWER THAN 2-3 MILES...IT CAN SNOW
FOR A YEAR LIKE THAT AND NOT AMOUNT TO MUCH. OVERALL TRIMMED
ADDITIONAL AMOUNTS DOWN TO LITTLE MORE THAN AN INCH IN SOME SPOTS.
WITH THE CORE OF THE COLDEST AIR PASSING OVERHEAD TODAY...SHOULD
BE A FAIR AMOUNT OF CLOUDINESS WITH A FEW PASSING FLURRIES...MAINLY
THIS MORNING AS THE GUIDANCE INDICATES CONTINUED DRYING TODAY.
HIGHS WILL RANGE FROM THE MID TEENS TO AROUND 30 FROM NORTH TO
SOUTH. WELL BELOW NORMAL FOR A CHANGE.
SKIES WILL CLEAR LEADING TO THE COLDEST NIGHT OF THIS YOUNG COLD
SEASON. TEMPERATURES AROUND ZERO OVER THE NORTH...WITH THE NORMAL
ICE BOX LOCALITIES LIKELY TO RING IN EVEN COLDER...WILL RANGE TO
ONLY A COUPLE OF DEGREES EITHER SIDE OF 10 ABOVE ALONG THE
MARYLAND BORDER.
&&
.SHORT TERM /TUESDAY/...
TUESDAY WILL BE BRIGHT AND SUNNY AS THE SURFACE HIGH PLOPS ITSELF
DOWN ON THE REGION. WE`LL ENJOY LIGHT WINDS WITH HIGHS RISING TO
THE MID 20S TO AROUND 30 FROM NORTH TO SOUTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE SURFACE HIGH WILL SLIDE OFF THE MID ATLANTIC COAST AS THE
UPPER RIDGE REBOUNDS OVER THE EASTERN STATES EARLY IN THE PERIOD.
THIS WILL LEAD TO A STEADY MODERATION IN TEMPERATURES THROUGH THE
END OF THE WEEK.
CONSENSUS SEEMS TO BE FOR SOME SORT OF COMPLEX STORM/FRONTAL
SYSTEM TO BRING THE NEXT CHANCE OF PRECIPITATION...LIKELY
RAIN...STARTING FRIDAY AND LASTING INTO THE WEEKEND.
BY EARLY FRIDAY MORNING GEFS AND ECMWF AGREE IN EJECTING ENOUGH
SHORTWAVE ENERGY INTO THE EASTERN RIDGE TO CHEW AWAY AT THE
EASTERN HEIGHTS PRETTY EFFECTIVELY...EVENTUALLY LEADING TO A
REESTABLISHMENT OF THE LONG WAVE TROUGH OVER THE CENTRAL US.
FROM THERE GUIDANCE DIVERGES WITH THE ECMWF ADVERTISING A FRIGID
AIRMASS DROPPING INTO THE UPPER MIDWEST AND GREAT LAKES BY THIS
TIME NEXT WEEK...WHILE THE GFS/GEFS ARE SLOWER AND NOT AS ROBUST
WITH THE COLD SHOT. INTERESTING TO NOTE THAT AFTER SUCH A WARM
START TO THE SEASON...MODELS ARE FINALLY STARTING TO SHOW HIGH
PRESSURE OVER NW NORTH AMERICA WHICH IS WHAT WE LOOK FOR AS A
DELIVERY SYSTEM OF COLD AIR INTO THE EASTERN US. STILL WELL ENOUGH
OUT IN THE EXTENDED TO TINKER WITH THE DETAILS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
STILL SOME CLOUDS ACROSS THE AREA WITH SCATTERED SNOW SHOWERS.
CONDITIONS SHOULD IMPROVE DURING THE DAY...WITH BFD AND JST THE
LAST TO CLEAR.
FROM TONIGHT INTO THU...LOOKING AT MAINLY CLEAR SKIES WITH
PLENTY OF SUNSHINE. VERY DRY AIR TODAY WILL ALLOW TEMPERATURES
TO DROP INTO THE SINGLE DIGITS TONIGHT...BEFORE TEMPERATURES
CLIMB TO ABOVE NORMAL AGAIN LATER IN THE WEEK. TOO DRY FOR FOG
TONIGHT. PERHAPS SOME FOG LATER IN THE WEEK...DEPENDING ON THE
DEWPOINTS AND IF THERE IS ANY SNOW LEFT ON THE GROUND.
OUTLOOK...
TUE-THU...NO SIG WX.
FRI...INCR CLOUDS. SHRA POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
638 AM EST MON JAN 4 2016
.SYNOPSIS...
NORTHWEST FLOW WILL CONTINUE TO DOMINATE THE PATTERN FOR THE NEXT
COUPLE OF DAYS WITH THE COLDEST AIR OF THE SEASON EXPECTED TO
START THIS FIRST FULL WEEK OF THE NEW YEAR. TEMPERATURES WILL
BEGIN TO MODERATE LATER IN THE WEEK AS HIGH PRESSURE BUILDS
EASTWARD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM THE IS SNOW SHOWERS ARE VERY SMALL...CELLULAR AND
DISORGANIZED...MORE LIKE SCATTERED FLURRIES. THE HRRR AND UCAR
ENSEMBLE SUPPORT ONLY ISOLATED MEASURABLE AMOUNTS AS THE OVER-LAKE
TRAJECTORIES SHORTEN UP AND INVERSION HEIGHTS LOWER RAPIDLY OVER
THE NEXT SEVERAL HOURS. KEPT LOW POPS AND LIMITED AND SNOW
ACCUM COVERAGE GIVEN THE MODEL AND RADAR TRENDS.
THE LAURELS WILL LIKELY SEE A SEVERAL HOUR PERIOD OF SNOW...BUT
WITH VISIBILITIES GENERALLY NO LOWER THAN 2-3 MILES...IT CAN SNOW
FOR A YEAR LIKE THAT AND NOT AMOUNT TO MUCH. OVERALL TRIMMED
ADDITIONAL AMOUNTS DOWN TO LITTLE MORE THAN AN INCH IN SOME SPOTS.
WITH THE CORE OF THE COLDEST AIR PASSING OVERHEAD TODAY...SHOULD
BE A FAIR AMOUNT OF CLOUDINESS WITH A FEW PASSING FLURRIES...MAINLY
THIS MORNING AS THE GUIDANCE INDICATES CONTINUED DRYING TODAY.
HIGHS WILL RANGE FROM THE MID TEENS TO AROUND 30 FROM NORTH TO
SOUTH. WELL BELOW NORMAL FOR A CHANGE.
SKIES WILL CLEAR LEADING TO THE COLDEST NIGHT OF THIS YOUNG COLD
SEASON. TEMPERATURES AROUND ZERO OVER THE NORTH...WITH THE NORMAL
ICE BOX LOCALITIES LIKELY TO RING IN EVEN COLDER...WILL RANGE TO
ONLY A COUPLE OF DEGREES EITHER SIDE OF 10 ABOVE ALONG THE
MARYLAND BORDER.
&&
.SHORT TERM /TUESDAY/...
TUESDAY WILL BE BRIGHT AND SUNNY AS THE SURFACE HIGH PLOPS ITSELF
DOWN ON THE REGION. WE`LL ENJOY LIGHT WINDS WITH HIGHS RISING TO
THE MID 20S TO AROUND 30 FROM NORTH TO SOUTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE SURFACE HIGH WILL SLIDE OFF THE MID ATLANTIC COAST AS THE
UPPER RIDGE REBOUNDS OVER THE EASTERN STATES EARLY IN THE PERIOD.
THIS WILL LEAD TO A STEADY MODERATION IN TEMPERATURES THROUGH THE
END OF THE WEEK.
CONSENSUS SEEMS TO BE FOR SOME SORT OF COMPLEX STORM/FRONTAL
SYSTEM TO BRING THE NEXT CHANCE OF PRECIPITATION...LIKELY
RAIN...STARTING FRIDAY AND LASTING INTO THE WEEKEND.
BY EARLY FRIDAY MORNING GEFS AND ECMWF AGREE IN EJECTING ENOUGH
SHORTWAVE ENERGY INTO THE EASTERN RIDGE TO CHEW AWAY AT THE
EASTERN HEIGHTS PRETTY EFFECTIVELY...EVENTUALLY LEADING TO A
REESTABLISHMENT OF THE LONG WAVE TROUGH OVER THE CENTRAL US.
FROM THERE GUIDANCE DIVERGES WITH THE ECMWF ADVERTISING A FRIGID
AIRMASS DROPPING INTO THE UPPER MIDWEST AND GREAT LAKES BY THIS
TIME NEXT WEEK...WHILE THE GFS/GEFS ARE SLOWER AND NOT AS ROBUST
WITH THE COLD SHOT. INTERESTING TO NOTE THAT AFTER SUCH A WARM
START TO THE SEASON...MODELS ARE FINALLY STARTING TO SHOW HIGH
PRESSURE OVER NW NORTH AMERICA WHICH IS WHAT WE LOOK FOR AS A
DELIVERY SYSTEM OF COLD AIR INTO THE EASTERN US. STILL WELL ENOUGH
OUT IN THE EXTENDED TO TINKER WITH THE DETAILS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
CLOUD DECK COVERING ALL BUT SE SLIVER OF CWA THIS EVENING...THOUGH
LOW CLOUDS/RESTRICTIONS CONFINED TO MAINLY NORTHERN AND WESTERN
HIGHER TERRAIN - AIDED BY UPSLOPE FLOW AND CAA.
A COLD FRONT DROPPING INTO NORTHERN PA AT 01Z WILL CONTINUE TO
PUSH SOUTHEASTWARD ACROSS CENTRAL PA TONIGHT...ACCOMPANIED BY
SCTD SNOW SHOWERS AND POSSIBLY A SQUALL MAINLY IMPACTING AREAS
NORTH OF I-80 AND WEST OF I-99. BEHIND THE FRONT...LAKE-EFFECT
AND UPSLOPE SNOW SHOWERS WILL SETTLE IN TO AFFECT PRIMARILY THE
WRN HIGHLANDS /KBFD AND KJST/ OVERNIGHT INTO EARLY MONDAY...
ACCOMPANIED BY REDUCED CIGS AND VSBYS.
CONDITIONS SHOULD GRADUALLY IMPROVE ON MONDAY...AS HIGH PRES
BUILDS IN. VFR CONDITIONS SHOULD BE IN PLACE IN MOST AREAS BY
12Z...WITH WRN HIGHLANDS GRADUALLY IMPROVING THROUGH THE DAY.
AFTER THAT...HIGH PRES WILL REMAIN IN CONTROL THROUGH THURS. THE
NEXT WEATHER MAKER COULD BRING SOME RAIN SHOWERS INTO CENTRAL PA
BY FRI.
OUTLOOK...
MON...REDUCTIONS ACROSS WESTERN HIGHER TERRAIN IN SNOW SHOWERS
AND POTENTIAL SQUALLS. OTHERWISE MAINLY VFR. BREEZY.
TUE-THU...NO SIG WX.
FRI...INCR CLOUDS. SHRA POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN/RXR
AREA FORECAST DISCUSSION
NWS SEATTLE WA
358 AM PST MON JAN 4 2016
.SYNOPSIS...AN UPPER LEVEL LOW CENTERED NEAR VANCOUVER BRITISH
COLUMBIA THIS MORNING WILL SLOWLY MOVE NORTH AND EAST TODAY. A
WINTERY MIX OF LIGHT PRECIPITATION THIS MORNING WILL BECOME ALL
RAIN THIS AFTERNOON AS THE AIR MASS MODERATES. ANOTHER WEAK SYSTEM
WILL REACH THE AREA ON TUESDAY. AFTER A SHORT DRY SPELL MORE WEAK
SYSTEMS WILL REACH THE AREA FRIDAY INTO THE WEEKEND.
&&
.SHORT TERM...SATELLITE IMAGERY SHOWS UPPER LEVEL LOW NEAR
VANCOUVER BRITISH COLUMBIA EARLY THIS MORNING. BAND OF LIGHT
PRECIPITATION WRAPPING AROUND THE LOW OVER MOST OF THE INTERIOR
LOWLANDS AT 3 AM. WITH THE LACK OF CLOUD COVER ALONG THE NORTH
COAST TEMPERATURES DROPPED INTO THE MID 20S. FOR THE REMAINDER OF
THE LOWLANDS WITH SOME CLOUD COVER LOWER TO MID 30S WERE COMMON.
UPPER LEVEL LOW DRIFTING OFF TO THE NORTH AND EAST THIS MORNING
WITH THE LIGHT PRECIPITATION BAND MOVING WITH THE LOW. EARLY THIS
MORNING TEMPERATURES NEAR FREEZING OVER THE SOUTHWEST
INTERIOR...SOUTH SOUND AND THE CASCADES FOOTHILLS WILL RESULT IN A
WINTERY MIX...SNOW OR BRIEF FREEZING RAIN...OF LIGHT
PRECIPITATION. WILL EXTEND THE WINTER WEATHER ADVISORY UNTIL 10
AM. FOR THE REMAINDER OF THE AREA JUST A CHANCE OF LIGHT RAIN OR
SNOW WITH THE BEST CHANCES FOR SNOW OVER THE NORTHWEST INTERIOR.
BOTH THE NAM AND THE GFS HAVE OVER FORECASTED THE PRECIPITATION
AMOUNTS OVERNIGHT. WILL LEAN MORE TOWARD THE HRRR SOLUTION FOR THE
PRECIPITATION AMOUNTS. STILL A CHANCE OF PRECIPITATION WITH THE
SLOW MOVEMENT OF THE UPPER LEVEL LOW THIS AFTERNOON. THE AIR MASS
WILL SLOWLY WARM TODAY WITH THE WEAKENING LOW LEVEL OFFSHORE FLOW
AND WEST SOUTHWESTERLY FLOW ALOFT. BY THIS AFTERNOON THE SNOW
LEVEL WILL BE AT LEAST 1000 FEET. HIGHS THIS AFTERNOON AROUND 40
DEGREES.
UPPER LEVEL LOW OVER BRITISH COLUMBIA CONTINUING TO LIFT NORTH
TONIGHT WITH ANOTHER UPPER LEVEL LOW DEVELOPING OFF THE SOUTHERN
OREGON COAST. THIS LOW WILL MOVE NORTH ON TUESDAY WITH A WEAK
SYSTEM SPINNING OUT OF THE LOW MOVING INTO WESTERN WASHINGTON IN
THE AFTERNOON. THE AIR MASS WILL CONTINUE TO WARM OVERNIGHT INTO
TUESDAY KEEPING THE THREAT OF FROZEN PRECIPITATION CONFINED TO THE
MOUNTAINS. LOWS TONIGHT WILL BE IN THE 30S WITH HIGHS ON TUESDAY
IN THE UPPER 30S TO MID 40S.
UPPER LEVEL LOW MOVING BY TO THE WEST TUESDAY NIGHT INTO EARLY
WEDNESDAY MORNING KEEPING THE THREAT OF PRECIPITATION OVER THE
AREA. THE LOW WILL BE NORTH OF WESTERN WASHINGTON BY LATE
WEDNESDAY MORNING. ANOTHER UPPER LOW OFF THE SOUTHERN
OREGON/NORTHERN CALIFORNIA COAST WILL PULL THE NEXT SYSTEM SOUTH
OF THE AREA WEDNESDAY AFTERNOON. HIGHS WILL BE MOSTLY IN THE LOWER
TO MID 40S.
.LONG TERM...EXTENDED MODELS STARTING TO SHOW A LITTLE BIT MORE
CONSISTENCY IN THEIR SOLUTIONS THIS MORNING. BOTH THE GFS AND THE
ECMWF HAVE THE NEXT UPPER LEVEL LOW REMAINING WELL SOUTH OF THE
AREA WEDNESDAY NIGHT AND THURSDAY FOR A SHORT DRY SPELL. BOTH
MODELS ARE ALSO INDICATING SOME RIDGING OFFSHORE FOR FRIDAY AND
SPLIT FLOW ALOFT OFFSHORE OVER THE WEEKEND WHICH WOULD LEAD TO
MORE DRY DAYS. WITH THE INCONSISTENCY IN THE MODELS LATELY DO NOT
WANT TO COMPLETELY DRY OUT THE EXTENDED FORECAST. WILL LEAVE THE
CHANCE POPS IN THE FRIDAY THROUGH SUNDAY TIME FRAME FOR THIS
FORECAST PACKAGE. FELTON
&&
.AVIATION...AN UPPER LOW OVER SOUTHWEST BRITISH COLUMBIA WILL
DRIFT NORTH TODAY AND TONIGHT WITH SOUTHWEST FLOW ALOFT FOR
WESTERN WASHINGTON. AT THE SURFACE...OFFSHORE FLOW WILL PREVAIL
WITH HIGHER PRESSURE OVER EASTERN WASHINGTON. THE AIR MASS IS
MOIST AND STABLE.
KSEA...IFR CEILINGS EARLY THIS MORNING LIFTING TO MVFR BY LATE
MORNING. CEILINGS IMPROVING TO VFR LATE THIS AFTERNOON INTO THE
EVENING HOURS. NORTHERLY WIND 4-8 KNOTS.
A SOUTHWEST-NORTHEAST ORIENTED BAND OF PRECIPITATION WILL BRUSH
THE TERMINAL EARLY THIS MORNING...WITH A RAIN/SNOW MIX. THE BAND
IS EXPECTED TO WEAKEN AND SHIFT EAST BY 15Z. PRECIPITATION AFTER
THAT WILL BE SPOTTY AND ALL RAIN. SNOW ACCUMULATIONS AT THE
TERMINAL...IF ANY...SHOULD BE MINOR THIS MORNING.
THE SNOW LEVEL WILL BE NEAR THE SURFACE EARLY THIS MORNING...THEN
RISE TO AROUND 1000 FEET LATE THIS MORNING AND TO 3000 FEET THIS
AFTERNOON. SCHNEIDER
&&
.MARINE...A SERIES OF FRONTAL SYSTEMS WILL MOVE THROUGH THE COASTAL
WATERS THIS WEEK. AT THE SAME TIME...HIGHER PRESSURE WILL BE EAST
OF THE CASCADES...MAINTAINING OFFSHORE FLOW. SMALL CRAFT ADVISORY
EASTERLY WINDS ARE POSSIBLE AT TIMES...MAINLY FOR THE COASTAL
WATERS AND WEST ENTRANCE STRAIT OF JUAN DE FUCA. 10-15 FOOT WEST
SWELL WILL REACH THE WATERS LATER TUESDAY AND PERSIST THROUGH
ABOUT THURSDAY. SCHNEIDER
&&
.HYDROLOGY...FLOODING IS NOT EXPECTED FOR THE NEXT 7 DAYS.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING FOR EAST
PUGET SOUND LOWLANDS-SOUTHWEST INTERIOR-TACOMA AREA.
PZ...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM PST TUESDAY
COASTAL WATERS.
SMALL CRAFT ADVISORY UNTIL 6 PM PST TUESDAY FOR WEST ENTRANCE
U.S. WATERS STRAIT OF JUAN DE FUCA.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
603 AM CST MON JAN 4 2016
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 248 AM CST MON JAN 4 2016
THE FIRST CONCERN IS WITH WHAT THE CLOUD COVER IS GOING TO DO
TODAY. A NARROW AREA OF CLEARING HAS WORKED INTO THE WESTERN
SECTIONS BUT IS SURROUNDED BY THE LOW CLOUDS BOTH TO THE WEST AND
EAST. THE 04.06Z RAP 0.5KM RELATIVE HUMIDITY SUGGESTS THE CLOUDS
TO THE EAST OF THIS CLEARING SLOT WILL EVENTUALLY START MOVING
BACK TO THE WEST SO THAT THE CLOUDS COVER THE ENTIRE FORECAST AREA
AGAIN BY 12Z. HAVE TRENDED TOWARD THIS SOLUTION TO START THE DAY.
THE NEXT CONCERN IS WITH A THINNING AREA OF CLOUDS OVER NORTHEAST
WISCONSIN THAT THE RAP SUGGEST THEN WORKS INTO CENTRAL WISCONSIN
BY MID MORNING AND THE WORKS WEST ACROSS MOST OF THE AREA THROUGH
THE DAY. HAVE TRIED TO HANDLE THIS TREND BY SHOWING A DECREASE IN
THE CLOUDS OVER THE EASTERN SECTIONS DURING THE MORNING WITH A
DECREASING CLOUDS TREND FOR THE REST OF THE AREA THROUGH THE
AFTERNOON.
THE NEXT CHANCE FOR PRECIPITATION WILL COME WEDNESDAY AFTERNOON.
THE UPPER LEVEL RIDGE AXIS WILL SLIDE ACROSS THE REGION MONDAY
NIGHT AND TUESDAY SETTING UP A SOUTHWEST FLOW ALOFT. A SHORT WAVE
TROUGH WILL COME OUT THE ROCKIES AND MOVE ACROSS THE AREA
WEDNESDAY AFTERNOON AND NIGHT. THIS DOES NOT LOOK TO BE THAT
STRONG OF A SHORT WAVE TROUGH AND THE 04.00Z GFS ONLY SHOWS SOME
WEAK PV ADVECTION IN THE 500-300 MB LAYER. NOT A LOT OF
THERMODYNAMIC FORCING EITHER AS THERE IS NO FRONTOGENESIS AND
ABOUT 1 TO 3 UBAR/S OF UP GLIDE ON THE 285K ISENTROPIC SURFACE. IT
LOOKS LIKE A LOT OF THE FORCING FROM THIS WAVE WILL GO INTO
SATURATING THE COLUMN...WHICH SHOULD TAKE UNTIL THE AFTERNOON TO
OCCUR...AND THEN ONCE SATURATION IS ACHIEVED...THERE IS NOT A LOT
OF LIFT LEFT FOR PRECIPITATION PRODUCTION. WITH SATURATION NOT
OCCURRING UNTIL AFTERNOON...REMOVED THE SMALL SNOW CHANCES FROM
WEDNESDAY MORNING AND THEN KEPT THEM IN THE 20 TO 40 PERCENT RANGE
FOR THE AFTERNOON. THE BEST CHANCES FOR PRECIPITATION WILL
PROBABLY OCCUR WEDNESDAY EVENING WHEN THE WEAK FORCING FROM THE
WAVE AND ISENTROPIC UP GLIDE CAN WORK ON THE SATURATED COLUMN TO
PRODUCE SOME LIGHT SNOW AND RAISED THE CHANCES UP TO 50 PERCENT
ACROSS THE NORTHERN SECTIONS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 248 AM CST MON JAN 4 2016
THURSDAY LOOKS TO BE TRANSITION DAY WITH THE AREA BETWEEN SYSTEMS.
AS THE SHORT WAVE TROUGH FROM WEDNESDAY NIGHT MOVES OFF TO THE
EAST...THERE SHOULD BE A PERIOD OF SHORT WAVE RIDGING ALOFT THAT
MOVES ACROSS THE AREA. THE ISENTROPIC UP GLIDE DROPS OFF TO
VIRTUALLY NOTHING AS THE BEST AREA OF WARM AIR ADVECTION SHIFTS
EAST WITH THE DEPARTING SHORT WAVE TROUGH. IF THERE IS
PRECIPITATION AROUND THURSDAY...HAVE CONCERNS ON WHAT TYPE IT WILL
BE. THE GFS SOUNDINGS SHOW A LACK OF ICE IN THE CLOUDS AS DRYING
ALOFT OCCURS WITH THE SHORT WAVE RIDGING. THIS COULD LEAD TO A
PERIOD OF SOME FREEZING DRIZZLE UNTIL TEMPERATURES REACH THE
FREEZING MARK IN THE AFTERNOON. FOR NOW...WILL STAY WITH RAIN OR
SNOW BUT LATER FORECASTS MAY HAVE TO START CONSIDERING OTHER
PRECIPITATION TYPES.
THE NEXT SHORT WAVE TROUGH COMING TOWARD THE AREA IN THE SOUTHWEST
FLOW IS HANDLED PRETTY SIMILARLY BY THE GFS AND 04.00Z ECMWF WITH
THEM COMING INTO BETTER AGREEMENT THAT THIS SYSTEM SHOULD TRACK TO
THE SOUTH OF THE AREA. THERE ARE STILL MINOR DIFFERENCES ON THE
TIMING AND STRENGTH OF THIS SYSTEM...BUT LOOKING AT THE GFS
FORECAST SOUNDINGS...THE FARTHER SOUTH TRACK SHOULD NOT BRING IN
MUCH WARM AIR ALOFT OR PRESENT PROBLEMS WITH ICE IN THE CLOUDS.
THIS SHOULD KEEP THE PRECIPITATION TYPES CONTROLLED BY THE LOW
LEVEL THERMAL STRUCTURE AND WITH HIGHS FRIDAY EXPECTED TO BE THE
MIDDLE TO UPPER 30S...SHOULD SEE A MIX OF RAIN/SNOW OR ALL RAIN BY
THE AFTERNOON. ANOTHER SHORT WAVE TROUGH LOOKS TO TAKE A VERY
SIMILAR TRACK FOR SOME LOW END PRECIPITATION CHANCES FRIDAY NIGHT
INTO SATURDAY. THE MODELS THEN DIVERGE ON HOW STRONG THE NORTHERN
STREAM FLOW WILL BE WITH THE ECMWF WRAPPING UP A LARGE UPPER LEVEL
LOW OVER SOUTHERN CANADA WHILE THE GFS IS CONSIDERABLY WEAKER
WITH THIS FLOW AND KEEPS THE NORTHERN STREAM ENERGY STRUNG OUT IN
A TROUGH FROM HUDSON BAY ACROSS THE NORTHERN GREAT LAKES INTO THE
NORTHERN ROCKIES. BOTH MODELS AGREE THAT COLDER AIR WILL ARRIVE
OVER THE WEEKEND ONCE THE SURFACE LOW GOES BY WITH THE FRIDAY
NIGHT/SATURDAY SHORT WAVE TROUGH. SINCE THE ECMWF IS STRONGER WITH
THE NORTHERN STREAM IT SPREADS IN MORE COLD AIR AND SUGGESTS THE
HIGHS SUNDAY WOULD ONLY BE IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO WHILE THE GFS IS SOMEWHAT WARMER WITH HIGHS IN THE SINGLE
DIGITS AND TEENS ABOVE ZERO. FOR NOW...HAVE NOT GONE THAT COLD
WITH THE TEMPERATURES...BUT DID TREND THEM BELOW THE MODEL
CONSENSUS...ESPECIALLY ACROSS THE WEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 602 AM CST MON JAN 4 2016
KLSE AND KRST HAVE TWO VERY DIFFERENT FORECASTS FOR THE PERIOD.
SKIES ARE CLEARING OVER WI WHILE AN LIFR REGION OVER SERN MN AND
IA IS PERSISTING TO JUST EAST OF KRST. WI IS DOMINATED BY A
NORTH-NORTHEAST FLOW WHILE SERN MN HAS FLOW FROM THE WEST.
CONFIDENCE IS LOW ON HOW THE LIFR WILL LIFT TODAY AT KRST. THE TAF
SHOULD BE CONSIDERED ROUGH GUIDANCE ON THE LIFR TRENDS...AS THE
EDGE TO THE LIFR IS ONLY JUST EAST OF THE AIRFIELD AT 6 AM THIS
MORNING. BEING ON THE EDGE OF AN LIFR REGION CAN SOMETIMES CAUSE
AN EARLIER IMPROVEMENT TIME IN CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
329 PM EST MON JAN 4 2016
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOW AN AMPLIFIED UPPER LEVEL
PATTERN IN PLACE OVER THE CONUS. POTENT SHORTWAVE DISTURBANCE HAS
ARRIVED OVER SOUTHERN CALIFORNIA/BAJA REGION...AND IS PUSHING
INLAND ACROSS THE SOUTHWEST STATES. THE FLOW QUICKLY CHANGES
DOWNSTREAM TO HIGH AMPLITUDE RIDGING OVER THE INTER-MOUNTAIN WEST
AND CENTRAL PLAINS. THE DOWNSTREAM FLOW THEN FLIPS QUICKLY ONCE
AGAIN AS THE NORTHERN STREAM DIPS RAPIDLY INTO A SHARP AND COLD
TROUGH DIGGING THROUGH THE GREAT LAKES/NORTHEAST /MID-ATLANTIC
STATES. SHORTWAVE ENERGY AT THE BASE OF THIS EASTERN CONUS TROUGH
HAS PASSED TO OUR NORTH TODAY...AND IS NOW OFF THE GA/NE FLORIDA
COAST. LARGE SCALE SYNOPTIC FORCING/DEEP LAYER Q-VECTOR
CONVERGENCE AHEAD OF THIS SHORTWAVE HAS SHIFTED WELL TO THE EAST
AND SOUTHEAST OF OUR FORECAST AREA...WITH A RAIN-FREE FORECAST
FOR ALL ZONES THE REST OF THE DAY. DRYING OF THE DEEP LAYER COLUMN
WILL CONTINUE INTO THE EVENING...AND WOULD EXPECT TO SEE PW VALUES
WITH THE KTBW EVENING SOUNDING LOWER THAN WHAT WAS MEASURED AT 12Z
THIS MORNING.
THE AIRMASS ARRIVING BEHIND THE FRONT IS NOT ALL THAT COLD
(ESPECIALLY FOR THE TIME OF YEAR)...HOWEVER AFTER THE WARMTH OF
DECEMBER...IT CERTAINLY FEELS LIKE A BIG CHANGE. DESPITE THE
ABUNDANT SUNSHINE TODAY...HIGH TEMPERATURES HAVE ONLY RESPONDED UP
INTO THE 60S. SHOULD BE NOW JUST ABOUT REACHING OUR HIGH TEMPS
FOR THE DAY AS OF 3PM...AND WILL NOW BEGIN TO SEE THESE READINGS
DROPPING BACK OVER THE NEXT COUPLE OF HOURS. THIS TREND WILL LEAD
INTO ONE OF THE COOLER NIGHTS OF THE SEASON SO FAR.
&&
.SHORT TERM...
TONIGHT APPEARS AS THOUGH IT WILL BE THE COLD NIGHT FOR THE WEEK.
HIGH PRESSURE SETS UP WELL TO OUR NORTH ALLOWING FOR A COOL
NORTHERLY FLOW DOWN THE SPINE OF THE PENINSULA TO CONTINUE. THE
POSITION OF THE HIGH KEEPS THE GRADIENT TIGHT ACROSS THE ENTIRE
AREA...AND IT IS UNLIKELY THAT DECOUPLING OF THE BOUNDARY LAYER WILL
OCCUR...EVEN OVER THE FAR NORTHERN NATURE COAST ZONES.
THEREFORE...NOT LOOKING FOR MUCH IN THE WAY OF RADIATIVE PROCESSES
OVERNIGHT...BUT RATHER AN ADVECTION OF COOLER AIR FROM THE NORTH.
ONE OF THE COLDER NIGHT OF THE SEASON SO FAR IS LIKELY...ALTHOUGH
GENERALLY SPEAKING MOS TENDS TO BE A BIT ON THE COLD SIDE WITH
ADVECTION EVENTS. PAST SEVERAL GUIDANCE CYCLES...MOS HAS SUGGESTED
THAT TEMPS MAY APPROACH FREEZING TOWARD DAWN ACROSS PARTS OF LEVY
COUNTY. BASED ON THE MOS BIAS HAVE NOT DEVIATED FROM EARLIER
FORECAST AND WILL KEEP TEMPS IN THE MID 30S AROUND CHIEFLAND.
ALTHOUGH PATCHY FROST IS POSSIBLE WITH TEMPERATURES IN THE MID
30S...THE POTENTIAL FOR FROST TONIGHT APPEARS LOW FOR THESE FAR
NORTHERN AREAS. FAILING TO DECOUPLE ALONE MIGHT PREVENT IT...BUT
ALSO LOOKING FOR A FAIRLY LARGE DEWPOINT DEPRESSIONS. WOULD TEND
TO LOOK FOR DEWPOINT DEPRESSIONS LESS THAN 5 DEGREES IF FROST WAS
GOING TO BE THREAT...AND CURRENTLY NOT SEEING THAT IN THE
GUIDANCE. SO...FORECAST FOR TONIGHT WILL FEATURE MOSTLY CLEAR
SKIES...A STEADY NORTHEAST BREEZE...AND LOW TEMPS BY SUNRISE
RANGING FROM THE MID 30S FAR NORTH...TO THE MID 40S IN THE I-4
CORRIDOR...AND MIDDLE TO UPPER 40S FURTHER SOUTH. NORMALLY WARMER
SPOTS WITH A NORTHEAST BREEZE OFF THE WATER...SUCH AS SOUTHERN
PINELLAS COUNTY...AND THE ISLAND OF CHARLOTTE HARBOR SHOULD HOLD
IN THE LOWER 50S. WITH THE LIGHT BREEZE...WIND CHILLS IN THE 30S
ARE FORECAST TO EXTEND AS FAR SOUTH AS NORTHEAST HILLSBOROUGH
COUNTY AND NORTHERN POLK COUNTY BY SUNRISE. COLDEST WIND CHILL
VALUES...POTENTIAL IN THE UPPER 20S...WILL BE FOUND ACROSS LEVY
COUNTY.
A PLEASANT...SEASONABLE...BUT BREEZY DAY IN STORE FOR TUESDAY.
HIGH PRESSURE REMAINS CENTERED WELL TO OUR NORTH KEEPING OUR WINDS
OUT OF THE NORTHEAST THROUGH THE DAY. CERTAINLY LOOKS AS THROUGH
IT WILL BE WINDY ON SOME OF THE AREA LAKES BY MID TO LATE
MORNING...SO BE AWARE OF THAT POTENTIAL. A NORTHEAST BREEZE WITH
GUSTS OVER 20 MPH APPEARS WIDESPREAD FOR THE REGION. HIGH
TEMPERATURES STRUGGLING TO REACH THE LOWER 60S UP TOWARD
CHIEFLAND...BUT RECOVERING INTO THE MID/UPPER 60S THROUGH THE I-4
CORRIDOR...AND TO RIGHT AROUND 70 DEGREES FOR PLACES LIKE
SARASOTA/PUNTA GORDA/FORT MYERS. LOOK FOR A MIX OF SUN AND
INCREASING COVERAGE OF A SHALLOW CUMULUS FIELD THROUGH THE
DAYLIGHT HOURS.
HAVE A GREAT MONDAY EVENING EVERYONE!
&&
.LONG TERM (TUESDAY NIGHT-MONDAY)...
A MID-LEVEL RIDGE OVER EASTERN PART OF THE COUNTRY ON TUESDAY NIGHT
WILL SHIFT EASTWARD THROUGH WEDNESDAY AS SHORTWAVE ENERGY MOVES
ACROSS THE GULF AND FLORIDA. AT THE SURFACE...THE AREA OF HIGH
PRESSURE CENTERED OVER THE EASTERN SEABOARD WILL SHIFT EASTWARD OVER
THE WESTERN ATLANTIC WITH FLOW BECOMING MORE EASTERLY. THIS SETUP
WILL KEEP A CHANCE FOR SHOWERS IN THE FORECAST...MAINLY FOR THE
SOUTHERN AND INLAND PORTIONS OF THE FORECAST AREA. MODELS ARE IN
GOOD AGREEMENT IN SHOWING A SURFACE LOW DEVELOPING NEAR THE BAHAMAS
WEDNESDAY NIGHT AND SHIFTING NORTHEASTWARD AWAY FROM THE AREA
THROUGH THURSDAY. THIS IS AHEAD OF THE NEXT IN A SERIES OF
SHORTWAVES AND ASSOCIATED SURFACE LOWS AND BOUNDARIES THAT WILL BE
MOVING THROUGH THE SOUTHEAST. IN BETWEEN THESE FEATURES...EXPECT A
MAINLY RAIN-FREE DAY FOR THURSDAY WITH TEMPERATURES WARMING BY A FEW
DEGREES INTO THE LOWER TO MID 70S.
FOR THURSDAY NIGHT INTO FRIDAY...A WEAK SURFACE LOW OR TROUGH FORMS
SOMEWHERE ALONG THE NORTHERN GULF COAST/BIG BEND REGION...SHIFTING
NORTHEAST THROUGH THE DAY. THIS WILL BRING A CHANCE FOR SHOWERS TO
THE AREA...WITH THE BEST CHANCES OVER THE WESTERN PART OF THE
PENINSULA.
RAIN CHANCES INCREASE AGAIN FOR SATURDAY THROUGH SUNDAY AS ANOTHER
SHORTWAVE MOVES THROUGH THE SOUTHERN STREAM AND A SURFACE LOW
DEVELOPS OVER THE SOUTHEAST AND SHIFTS NORTHEASTWARD TOWARD NEW
ENGLAND. THE BEST RAIN CHANCES LOOK TO BE DURING THE DAY ON
SUNDAY...WITH HIGH PRESSURE THEN STARTING TO BUILD OVER THE
SOUTHEAST THROUGH MONDAY...ALTHOUGH STILL SOME UNCERTAINTY IN THE
FORECAST AND WILL LEAVE A SLIGHT CHANCE FOR SHOWERS IN PLACE.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL FOR THE DURATION OF THE TAF PERIOD
ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA. BREEZY NORTH TO
NORTHEAST WINDS WILL ALSO PERSIST. PREVAILING VFR CONDITIONS ARE
EXPECTED TO CONTINUE WITH GUSTY NORTHEAST WINDS THROUGH THE
DAYLIGHT HOURS OF TUESDAY.
&&
.MARINE...
SMALL CRAFT ADVISORY IN EFFECT FOR THE WATERS OF TAMPA BAY AND
CHARLOTTE HARBOR TONIGHT INTO TUESDAY MORNING.
SMALL CRAFT ADVISORY IN EFFECT OUT TO 20 NM FROM BONITA SPRINGS
TO THE SUWANNEE RIVER TONIGHT THROUGH LATE TUESDAY NIGHT.
SMALL CRAFT ADVISORY IN EFFECT FROM 20 TO 60 NM FROM BONITA
SPRINGS TO THE SUWANNEE RIVER TONIGHT THROUGH WEDNESDAY MORNING.
A STRONG AREA OF HIGH PRESSURE WILL CONTINUE TO BUILD NORTH OF
THE AREA TONIGHT. ELEVATED NORTH WINDS WILL QUICKLY BE INCREASING
TO ADVISORY LEVELS THIS EVENING AS THEY TURN TO THE NORTHEAST.
WINDS AND SEAS WILL LIKELY BE NEAR OR OVER ADVISORY LEVELS TONIGHT
THROUGH TUESDAY NIGHT. THE GRADIENT IS EXPECTED TO RELAX DURING
THE SECOND HALF OF THE WEEK ALLOWING WINDS AND SEAS TO SUBSIDE.
&&
.FIRE WEATHER...
A MUCH DRIER AIRMASS HAS ARRIVED FROM THE NORTH. HIGH PRESSURE
WILL SET UP THROUGH MIDWEEK OVER THE MID-ATLANTIC STATES KEEPING
A GENERAL NORTHEAST WIND FLOW OVER THE REGION. THE VERY DRY LOW
LEVELS WILL BE SHORT-LIVED AS ATLANTIC MOISTURE BEGINS TO RETURN
DURING TUESDAY AND WEDNESDAY. AFTER MONDAY AFTERNOON...RELATIVE
HUMIDITY VALUES ARE NOT EXPECTED TO DROP BELOW CRITICAL VALUES
AGAIN FOR THE REMAINDER OF THE FORECAST PERIOD. HOWEVER...THE
FORECAST WILL FEATURE HIGH DISPERSION VALUES...AND GUSTY
NORTHEASTERLY WINDS ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA
DURING LATE TUESDAY MORNING AND AFTERNOON.
FOG POTENTIAL...NO SIGNIFICANT AREA OF FOG OR REDUCED VISIBILITY
ARE EXPECTED THE NEXT SEVERAL NIGHTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 48 67 54 72 / 0 0 10 30
FMY 51 71 58 72 / 0 0 30 50
GIF 48 67 54 71 / 0 0 10 40
SRQ 50 69 56 73 / 0 0 10 30
BKV 43 64 50 70 / 0 0 10 20
SPG 51 67 57 71 / 0 0 10 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
WEDNESDAY FOR WATERS FROM BONITA BEACH TO ENGLEWOOD
FL OUT 20 TO 60 NM-WATERS FROM ENGLEWOOD TO TARPON
SPRINGS FL OUT 20 TO 60 NM-WATERS FROM TARPON SPRINGS
TO SUWANNEE RIVER FL OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR COASTAL WATERS FROM BONITA BEACH TO
ENGLEWOOD FL OUT 20 NM-COASTAL WATERS FROM ENGLEWOOD
TO TARPON SPRINGS FL OUT 20 NM-COASTAL WATERS FROM
TARPON SPRINGS TO SUWANNEE RIVER FL OUT 20 NM.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
TUESDAY FOR CHARLOTTE HARBOR AND PINE ISLAND SOUND-
TAMPA BAY WATERS.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT...CARLISLE
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
249 PM CST MON JAN 4 2016
.SHORT TERM...(Tonight)
ISSUED AT 240 PM CST MON JAN 4 2016
Earlier hole in the stratocumulus has filled in across much of the
forecast area this afternoon, due to diurnal development and
additional clouds advecting in from Lake Michigan. Latest NAM 925 mb
humidity guidance suggesting the mostly cloudy trend to persist
through about 9 pm before clearing out, while the HRRR scatters the
clouds out closer to 6 pm. With the diurnal nature of most of the
clouds, leaned more toward the faster solution. As ridge axis pushes
east across the state, winds will trend toward the southeast after
midnight. Most locations should fall into the lower 20s overnight,
but some teens likely across the I-74 corridor.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 240 PM CST MON JAN 4 2016
Quiet weather pattern to hold across the area through Wednesday
evening as upper level heights build over the Midwest allowing
warmer air to filter back into the region. Temperatures will
moderate a few degrees on Tuesday with the stronger return flow
setting up Tuesday night into Wednesday. This should push temps
Wednesday afternoon to around 40 degrees with the above normal
temperatures holding into Saturday. The storm system that is slated
to push out of the Southern Plains later Wednesday will begin to
spread precip into our area by Thursday morning. If the precip does
arrive before dawn Thursday, most of the forecast models suggest
more of a rain or freezing rain threat across our far northern
areas. For now, will keep it rain or snow and refine any precip
type issues as we draw closer to the event. The better rain
chances will move in late Thursday, Thursday night into Friday as
the main area of forcing/lift from the southern stream wave
pushes across our area, with rainfall amounts still looking to be
around one half inch.
As the storm system shifts to our northeast on Saturday, colder air
poised to our northwest will shift southeast into the region with
steady or slowly falling temperatures for the afternoon. We will
still have low chance POPs going during the day with a transition
from rain, to a rain snow mixture as the colder air filters in
during the afternoon as gusty northwest winds build in. Much colder
air will shift into the area Saturday night and Sunday accompanied
by gusty northwest winds. Most models suggest 850 temps of around
-20C by late Satuday night or Sunday as the center of the cold air
mass slides southeast into our area. This should result in morning
lows of 10 to 20 degrees by Monday morning with daytime highs
struggling mostly through the 20s Monday afternoon with the below
normal temperatures expected to hold through most of next week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1137 AM CST MON JAN 4 2016
Skies cleared earlier this morning over central Illinois, but some
diurnal clouds around 2500 feet are quickly developing from KPIA-
KSPI westward. There are also lake-effect clouds tracking
southwest from the Chicago area. Main question will be how much of
the area is filled in with clouds this afternoon. Model humidity
analysis suggests a continued increase in clouds through 21Z,
before thinning out again after 02-03Z. May be some brief MVFR
conditions as the clouds thicken, but general trend has been for
ceilings quickly going above 3,000 feet. Northerly winds expected
to lighten this evening and trend easterly as high pressure moves
overhead, resulting in south winds prevailing on Tuesday.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Smith
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
156 PM CST MON JAN 4 2016
.UPDATE...
1227 PM CST
LAKE EFFECT SNOW INTENSITY HAS BEEN WINDING DOWN WITH RADAR TRENDS
AND LAND/COASTAL/SHIP OBS ALL SHOWING CONVERGENCE HAS LOST FOCUS.
COLD ADVECTION AND SUFFICIENT LAKE-850MB DELTA-TS CONTINUE TO
SUPPORT A BROAD AREA OF LIGHT SNOW SHOWERS AND FLURRIES AFFECTING
THE CHICAGO METRO AND POINTS SOUTH TO KANKAKEE AND NORTHERN
IROQUOIS COUNTIES AND EASTWARD ACROSS NORTHWEST INDIANA.
INVERSION HEIGHTS WILL BE FALLING AS MID LEVELS WARM AHEAD OF AN
ADVANCING MID/UPPER RIDGE. THIS WILL BRING A STEADY DECREASE IN
THE LIGHT SNOW SHOWER ACTIVITY. STILL MAY BE SOME SEMBLANCE OF
CONVERGENCE ACROSS CENTRAL/EASTERN LAKE COUNTY IL...NORTHERN COOK
COUNTY AND DUPAGE COUNTY SO COULD STILL SEE SOME MORE INTENSE SNOW
SHOWERS BRIEFLY OCCUR IN THESE AREAS OVER THE NEXT FEW HOURS. DO
NOT EXPECT MUCH IN THE WAY OF NEW ACCUMULATION...THOUGH AN
ADDITIONAL DUSTING MAY OCCUR IN AREAS THAT SEE REPEATED SNOW
SHOWERS WITH AN ISOLATED ADDITIONAL TENTH OR TWO POSSIBLE WHERE
BETTER ECHOES MOVE OVERHEAD.
MDB
&&
.SHORT TERM...
327 AM CST
THROUGH TUESDAY...
THE LAKE EFFECT SNOW IN THE FORECAST AREA TODAY STILL LOOKS LIKE
A GOOD POSSIBILITY AND THE MAIN FORECAST CHANGE WAS TO REFINE AND
HONE IN ON THE TIMING AND IMPACTS. REGARDING TIMING...THROUGH A
COMBINATION OF OBSERVATIONAL TRENDS AND HIGH-RESOLUTION GUIDANCE
HAVE SPED UP THE START TIME OF THE SNOW SHOWERS IN FAR NORTHEAST
ILLINOIS AND FAR NORTHWEST INDIANA AND ALSO LIMITED THE SNOW
SHOWER DURATION FROM PREVIOUS FORECAST. THIS DID RESULT IN LESS
AVERAGE FORECAST SNOWFALL TOTALS...THOUGH AS ALWAYS WITH LAKE
EFFECT SNOW SHOWERS THERE CAN BE A HIGH AMOUNT OF VARIABILITY OVER
SPACE. AROUND AN INCH IS FORECAST IN LAKE ADJACENT COUNTIES WITH
THE LIKELY POSSIBILITY OF LESS IN SOME SPOTS AND A LITTLE MORE IN
OTHERS. A DUSTING IS FORECAST IN THE SECOND TIER COUNTIES
SURROUNDING THE SOUTHERN PART OF THE LAKE.
THE UPPER AIR PATTERN EARLY THIS MORNING CONTINUES TO BE ONE OF
REINFORCING COLD AIR ALOFT OVER THE GREAT LAKES...WITH A 130KT DUE
SOUTHWARD POINTING JET ENTERING THE REGION. THE 850MB TEMPERATURES
ARE AROUND -13C OFFERING AROUND AN ESTIMATED 15C DIFFERENCE
BETWEEN THE 850MB AND LAKE SURFACE TEMPERATURES. THIS HAS
RESULTED IN BROAD SNOW SHOWERS ORIENTED INTO LOWER MICHIGAN AND
MAINLY LA PORTE COUNTY INDIANA THUS FAR.
AT THE SURFACE...A COLD FRONT IS ORIENTED NORTHWEST-TO-SOUTHEAST
OVER THE CENTRAL PART OF THE LAKE AHEAD OF AN ARCTIC HIGH THAT
WILL MODIFY AS IT CREEPS SOUTHWARD TODAY. PRESSURE RISES OF
4-5MB/3HR ARE PUSHING THE FRONT SOUTHWARD WITH MORE PRONOUNCED DRY
AIR BEHIND IT. ALONG THE BOUNDARY A LAKE-INDUCED CIRCULATION IS
PRESENT ON RADAR MOSAIC AND WIND STREAMLINE ANALYSIS OFF THE SHORE
OF LUDINGTON MICHIGAN. THIS FEATURE SHOULD CONTINUE SOUTHWARD DOWN
THE LAKE WITH THE SYNOPTIC BOUNDARY EARLY THIS MORNING ASSISTING
IS LOCALIZED CONVERGENCE AND LIKELY BRIEFLY ENHANCING SNOWFALL
RATES ON THE WESTERN FLANK WHICH RIGHT NOW IS EXPECTED TO CLIP FAR
NORTHEAST ILLINOIS AND INTO NORTHWEST INDIANA. A MORE PRONOUNCED
BAND OR COUPLE BANDS ARE STARTING TO DEVELOP UPSTREAM WITH THIS
AND SHOULD CONTINUE TO BETTER DEVELOP GIVEN THE FORECAST
CONVERGENCE AND SUGGESTED SOLUTIONS BY CONVECTIVE ALLOWING
GUIDANCE. LAKE-INDUCED CAPE AT THE LEADING EDGE OF THIS LOOKS TO
BE 100-200 J/KG WITH AN EQUILIBRIUM LEVEL AROUND 8000 FT PER
MODIFIED RAP AND NAM SOUNDINGS. THIS WILL LIKELY SUPPORT A BURST
OF MODERATE TO BRIEFLY HEAVY SNOW SHOWERS FOR SOME LOCATIONS
WHERE THIS COMES INLAND...ARRIVING BETWEEN 9-11 AM CURRENTLY
LOOKS LIKE THE BEST FORECAST TIME. HOWEVER THIS BAND/S/ LOOKS TO
HAVE A SNAKE-LIKE SHAPE AND BE FAIRLY PROGRESSIVE...THUS LIMITING
RESIDENCE TIME IN ANY ONE LOCATION AS THE FRONT AND MESOLOW PUSH
SOUTHWARD. SO WHILE A QUICK INCH OR A LITTLE OVER MAY OCCUR FOR
SOME...AMOUNTS AFTER THAT FIRST HOUR OR SO LOOK TO BE LESS. IT
ALSO LOOKS LIKE THE SNOW SHOULD SQUEEZE IN JUST BEHIND THE MORNING
COMMUTE...HELPING TO MINIMIZE IMPACTS SOME. WILL STILL LIKELY
ISSUE AN SPS JUST FOR THE POTENTIAL FOR A RAPID CHANGE IN
VISIBILITY EVEN IF BRIEF.
GOING INTO THE EARLY-MID AFTERNOON BEHIND THE FRONT...LESS
ORGANIZED SNOW SHOWERS OR FLURRIES WILL REMAIN WITH LIGHT
ADDITIONAL ACCUMULATION AS EQUILIBRIUM HEIGHTS LOWER ON A
STRENGTHENING SUBSIDENCE INVERSION. THE EXCEPTION MAY BE LAKE
COUNTY ILLINOIS AND NORTHERN COOK WHERE SOME CONVERGENCE WITH A
LONG FETCH IS FORECAST...SO RESIDENCE TIME OF LIGHT SNOW COULD
HELP TO YIELD AN ADDITIONAL HALF INCH OR MORE...BUT EVEN THAT
LOOKS TO WEAKEN THROUGH THE AFTERNOON AS DRY ADVECTION
STRENGTHENS.
HIGHS TODAY ARE FORECAST TO PEAK IN THE UPPER 20S IN MOST
LOCATIONS WITH GRADUALLY MORE SUNSHINE FORECAST IN THE AFTERNOON
AWAY FROM LAKE INDUCED CLOUDS. TONIGHT SHOULD SEE THE SKY CLEAR
IN MOST IF NOT ALL LOCATIONS. HAVE GONE TOWARD COOLER GFS-BASED
MOS GUIDANCE WITH WINDS DROPPING OFF AND SOME LOCATIONS HAVING A
TAD BIT OF FRESH SNOW. SOME UPPER SINGLE DIGITS ARE PROBABLY A
DECENT BET IN FAVORED COOLER LOCATIONS.
MTF
&&
.LONG TERM...
327 AM CST
TUESDAY NIGHT THROUGH SUNDAY...
A SLOW MODERATION CONTINUES TO BE FORECAST MIDWEEK WITH A
DAMPENING UPPER RIDGE SHIFTING EAST OVER THE AREA AND SOUTHWEST
850-1000MB FLOW DEVELOPING UNDERNEATH. THE BLOCKED PATTERN IN THE
WESTERN CONUS IS FORECAST TO BREAK DOWN WITH A STRONG WEST-TO-EAST
PACIFIC JET EXPANDING INTO SOUTHERN CALIFORNIA. A LEADING SHORT
WAVE EJECTING FROM THIS IS EXPECTED TO MOISTEN THE LOW-LEVEL FLOW
INTO THE MISSISSIPPI VALLEY REGION AND THAT STILL IS FORECAST
DURING LATER WEDNESDAY NIGHT INTO THURSDAY. WOULD NOT BE
SURPRISED TO SEE THIS SLOW DOWN A TAD. TEMPERATURES...
THICKNESSES...AND FORECAST PROFILES IN GENERAL STILL LOOK
SUPPORTIVE OF POTENTIALLY LIGHT SNOW OR A WINTRY MIX AT THE
LEADING EDGE OF SATURATED ASCENT.
THE MORE PRONOUNCED LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP
OVER THE CENTRAL PLAINS THURSDAY NIGHT INTO FRIDAY YIELDING DEEPER
MOISTURE TRANSPORT AND MORE WIDESPREAD LIFT WITHIN UPPER
DIFFLUENCE...ALL SUPPORTING LIKELY RAIN AT THIS JUNCTURE. THE LIFT
AND ESPECIALLY MOISTURE IS PRESENTLY NOT FORECAST TO THE MAGNITUDE
OF SEVERAL OF THE HEAVY RAIN DECEMBER SYSTEMS WE SAW...SO QPF IS
PRESENTLY BELOW AN INCH...BUT STILL ONE HALF TO THREE-QUARTERS OF
AN INCH OF RAIN IN JANUARY ON SATURATED GROUND IS NOTEWORTHY AND
SOMETHING WE WILL HAVE TO WATCH. THE 04.00 GFS CONTINUES JUST A
TAD FURTHER EAST AS DOES ITS ENSEMBLE COMPARED TO THE EC. IT WOULD
REQUIRE A FAIRLY LARGE SHIFT TO GET THE STRONGER COLD ADVECTION
WITH THIS SYSTEM GIVEN ITS SOMEWHAT BROAD NATURE...SO STILL FEEL
GOOD NOT MENTIONING ANY WINTERY PRECIPITATION CHANCES THURSDAY
NIGHT THROUGH FRIDAY NIGHT. EVEN DURING THE WEEKEND...WINTRY
PRECIPITATION PRESENTLY LOOKS TO BE LIGHT IF IT WERE TO
MATERIALIZE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NORTHEAST WINDS THIS AFTERNOON GRADUALLY VEERING TO THE
SOUTHEAST THIS EVENING...SOUTH TONIGHT...AND SOUTHWEST TUESDAY.
* FEW LINGERING LAKE EFFECT SNOW FLURRIES THROUGH THE AFTERNOON.
BMD
//DISCUSSION...UPDATED 18Z...
LAKE EFFECT SNOW HAS GENERALLY BEEN ON THE DOWNWARD TREND THOUGH
ONE SHOWER JUST UPSTREAM OF ORD COULD STILL BRING BRIEF IFR
CONDITIONS OVER THE NEXT HOUR THROUGH ROUGHLY 18Z WITH PRIMARILY
HIGH END MVFR OR VFR CONDITIONS EXPECTED AFTER 18Z. WINDS HAVE
SHIFTED TO THE NORTHEAST FOR MOST LOCATIONS ACROSS NORTHEASTERN
ILLINOIS WITH ORD BEING ONE OF THE FEW HOLDOUTS WITH A NNW
WIND...THOUGH THAT SHOULD ALSO SWING AROUND TO THE NNE OR NE BY
18-19Z. THEREAFTER...WINDS ARE EXPECTED TO VERY SLOWLY VEER
THROUGH THE PERIOD...BECOMING SOUTHEAST THIS EVENING...SOUTH
TONIGHT...AND EVENTUALLY SOUTHWEST TOMORROW. EXPECT SOME GUSTS
INTO THE HIGH TEENS TO AROUND 20 KT TUESDAY AFTERNOON. CIGS 025-45
ASSOCIATED WITH THE LAKE EFFECT WILL LINGER INTO MID
AFTERNOON...BUT EXPECT THESE TO DISSIPATE AS THE WINDS VEER TO THE
EAST/SOUTHEAST LEAVING VFR CONDITIONS THE REMAINDER OF THE
FORECAST PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN WINDS AND GENERAL TIMING.
* MEDIUM CONFIDENCE IN CIGS AND GENERAL TIMING.
* LOW CONFIDENCE IN END TIME OF FLURRIES...BUT HIGH IN NO
ADDITIONAL ACCUMULATION.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR/WX NIL.
WEDNESDAY...VFR/WX NIL.
THURSDAY...WINTRY MIX OF PCPN EARLY CHANGING OVER TO RAIN IN THE
AFTERNOON AND CONTINUING THROUGH THE NIGHT. MVFR CIG/VIS
LIKELY...IFR CONDITIONS POSSIBLE.
FRIDAY...RAIN LIKELY THROUGH THE DAY AND CONTINUING OVERNIGHT.
MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SATURDAY...CHANCE OF RAIN THROUGH THE DAY...CHANGING OVER TO SNOW
OVERNIGHT. MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF LINGERING LIGHT SNOW MORNING. MVFR CIG/VIS
POSSIBLE MORNING. OTRW...VFR/WX NIL.
KREIN
&&
.MARINE...
345 AM CST
MAIN MARINE CONCERN IN THE NEAR TERM IS A PERIOD OF NORTHWEST TO
NORTHEAST WINDS OF 20-25 KT WITH OCCASIONAL GUSTS TO 30
KT PRODUCING HAZARDOUS CONDITIONS FOR SMALL CRAFT ALONG BOTH THE
ILLINOIS AND INDIANA NEARSHORE WATERS THROUGH LATE THIS AFTERNOON
OR EARLY EVENING. WINDS WILL DIMINISH FAIRLY QUICKLY THIS EVENING
AS HIGH PRESSURE MOVES ACROSS THE LAKE THIS EVENING AND OVERNIGHT
TONIGHT.
WINDS WILL TURN TO THE SOUTH LATE TODAY NIGHT AS THE HIGH MOVES
OFF TO THE EAST... WITH THESE SOUTH WINDS INCREASING AS THE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A FAIRLY DEEP
AREA OF LOW PRESSURE TRACKING ACROSS HUDSON BAY. WINDS WILL RAMP
UP QUICKLY TO 30 KTS AND BECOME SOUTHWESTERLY ON NORTHERN LAKE
MICHIGAN LATE TONIGHT. A PERIOD OF SOUTHWEST GALES IS LIKELY
ACROSS THE NORTH HALF OF THE LAKE TUESDAY AND TUESDAY NIGHT WHEN
THE PRESSURE GRADIENT IS THE STRONGEST. THE GRADIENT WILL THEN
RELAX A BIT BY EARLY WEDNESDAY...AND WILL EVENTUALLY BACK TO THE
EAST THURSDAY NIGHT AS ANOTHER LOW LIFTS NORTHEAST FROM THE
SOUTHERN PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM MONDAY.
&&
$$
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
NWS CHICAGO/ROMEOVILLE IL
1230 PM CST MON JAN 4 2016
.UPDATE...
1227 PM CST
LAKE EFFECT SNOW INTENSITY HAS BEEN WINDING DOWN WITH RADAR TRENDS
AND LAND/COASTAL/SHIP OBS ALL SHOWING CONVERGENCE HAS LOST FOCUS.
COLD ADVECTION AND SUFFICIENT LAKE-850MB DELTA-TS CONTINUE TO
SUPPORT A BROAD AREA OF LIGHT SNOW SHOWERS AND FLURRIES AFFECTING
THE CHICAGO METRO AND POINTS SOUTH TO KANKAKEE AND NORTHERN
IROQUOIS COUNTIES AND EASTWARD ACROSS NORTHWEST INDIANA.
INVERSION HEIGHTS WILL BE FALLING AS MID LEVELS WARM AHEAD OF AN
ADVANCING MID/UPPER RIDGE. THIS WILL BRING A STEADY DECREASE IN
THE LIGHT SNOW SHOWER ACTIVITY. STILL MAY BE SOME SEMBLANCE OF
CONVERGENCE ACROSS CENTRAL/EASTERN LAKE COUNTY IL...NORTHERN COOK
COUNTY AND DUPAGE COUNTY SO COULD STILL SEE SOME MORE INTENSE SNOW
SHOWERS BRIEFLY OCCUR IN THESE AREAS OVER THE NEXT FEW HOURS. DO
NOT EXPECT MUCH IN THE WAY OF NEW ACCUMULATION...THOUGH AN
ADDITIONAL DUSTING MAY OCCUR IN AREAS THAT SEE REPEATED SNOW
SHOWERS WITH AN ISOLATED ADDITIONAL TENTH OR TWO POSSIBLE WHERE
BETTER ECHOES MOVE OVERHEAD.
MDB
&&
.SHORT TERM...
327 AM CST
THROUGH TUESDAY...
THE LAKE EFFECT SNOW IN THE FORECAST AREA TODAY STILL LOOKS LIKE
A GOOD POSSIBILITY AND THE MAIN FORECAST CHANGE WAS TO REFINE AND
HONE IN ON THE TIMING AND IMPACTS. REGARDING TIMING...THROUGH A
COMBINATION OF OBSERVATIONAL TRENDS AND HIGH-RESOLUTION GUIDANCE
HAVE SPED UP THE START TIME OF THE SNOW SHOWERS IN FAR NORTHEAST
ILLINOIS AND FAR NORTHWEST INDIANA AND ALSO LIMITED THE SNOW
SHOWER DURATION FROM PREVIOUS FORECAST. THIS DID RESULT IN LESS
AVERAGE FORECAST SNOWFALL TOTALS...THOUGH AS ALWAYS WITH LAKE
EFFECT SNOW SHOWERS THERE CAN BE A HIGH AMOUNT OF VARIABILITY OVER
SPACE. AROUND AN INCH IS FORECAST IN LAKE ADJACENT COUNTIES WITH
THE LIKELY POSSIBILITY OF LESS IN SOME SPOTS AND A LITTLE MORE IN
OTHERS. A DUSTING IS FORECAST IN THE SECOND TIER COUNTIES
SURROUNDING THE SOUTHERN PART OF THE LAKE.
THE UPPER AIR PATTERN EARLY THIS MORNING CONTINUES TO BE ONE OF
REINFORCING COLD AIR ALOFT OVER THE GREAT LAKES...WITH A 130KT DUE
SOUTHWARD POINTING JET ENTERING THE REGION. THE 850MB TEMPERATURES
ARE AROUND -13C OFFERING AROUND AN ESTIMATED 15C DIFFERENCE
BETWEEN THE 850MB AND LAKE SURFACE TEMPERATURES. THIS HAS
RESULTED IN BROAD SNOW SHOWERS ORIENTED INTO LOWER MICHIGAN AND
MAINLY LA PORTE COUNTY INDIANA THUS FAR.
AT THE SURFACE...A COLD FRONT IS ORIENTED NORTHWEST-TO-SOUTHEAST
OVER THE CENTRAL PART OF THE LAKE AHEAD OF AN ARCTIC HIGH THAT
WILL MODIFY AS IT CREEPS SOUTHWARD TODAY. PRESSURE RISES OF
4-5MB/3HR ARE PUSHING THE FRONT SOUTHWARD WITH MORE PRONOUNCED DRY
AIR BEHIND IT. ALONG THE BOUNDARY A LAKE-INDUCED CIRCULATION IS
PRESENT ON RADAR MOSAIC AND WIND STREAMLINE ANALYSIS OFF THE SHORE
OF LUDINGTON MICHIGAN. THIS FEATURE SHOULD CONTINUE SOUTHWARD DOWN
THE LAKE WITH THE SYNOPTIC BOUNDARY EARLY THIS MORNING ASSISTING
IS LOCALIZED CONVERGENCE AND LIKELY BRIEFLY ENHANCING SNOWFALL
RATES ON THE WESTERN FLANK WHICH RIGHT NOW IS EXPECTED TO CLIP FAR
NORTHEAST ILLINOIS AND INTO NORTHWEST INDIANA. A MORE PRONOUNCED
BAND OR COUPLE BANDS ARE STARTING TO DEVELOP UPSTREAM WITH THIS
AND SHOULD CONTINUE TO BETTER DEVELOP GIVEN THE FORECAST
CONVERGENCE AND SUGGESTED SOLUTIONS BY CONVECTIVE ALLOWING
GUIDANCE. LAKE-INDUCED CAPE AT THE LEADING EDGE OF THIS LOOKS TO
BE 100-200 J/KG WITH AN EQUILIBRIUM LEVEL AROUND 8000 FT PER
MODIFIED RAP AND NAM SOUNDINGS. THIS WILL LIKELY SUPPORT A BURST
OF MODERATE TO BRIEFLY HEAVY SNOW SHOWERS FOR SOME LOCATIONS
WHERE THIS COMES INLAND...ARRIVING BETWEEN 9-11 AM CURRENTLY
LOOKS LIKE THE BEST FORECAST TIME. HOWEVER THIS BAND/S/ LOOKS TO
HAVE A SNAKE-LIKE SHAPE AND BE FAIRLY PROGRESSIVE...THUS LIMITING
RESIDENCE TIME IN ANY ONE LOCATION AS THE FRONT AND MESOLOW PUSH
SOUTHWARD. SO WHILE A QUICK INCH OR A LITTLE OVER MAY OCCUR FOR
SOME...AMOUNTS AFTER THAT FIRST HOUR OR SO LOOK TO BE LESS. IT
ALSO LOOKS LIKE THE SNOW SHOULD SQUEEZE IN JUST BEHIND THE MORNING
COMMUTE...HELPING TO MINIMIZE IMPACTS SOME. WILL STILL LIKELY
ISSUE AN SPS JUST FOR THE POTENTIAL FOR A RAPID CHANGE IN
VISIBILITY EVEN IF BRIEF.
GOING INTO THE EARLY-MID AFTERNOON BEHIND THE FRONT...LESS
ORGANIZED SNOW SHOWERS OR FLURRIES WILL REMAIN WITH LIGHT
ADDITIONAL ACCUMULATION AS EQUILIBRIUM HEIGHTS LOWER ON A
STRENGTHENING SUBSIDENCE INVERSION. THE EXCEPTION MAY BE LAKE
COUNTY ILLINOIS AND NORTHERN COOK WHERE SOME CONVERGENCE WITH A
LONG FETCH IS FORECAST...SO RESIDENCE TIME OF LIGHT SNOW COULD
HELP TO YIELD AN ADDITIONAL HALF INCH OR MORE...BUT EVEN THAT
LOOKS TO WEAKEN THROUGH THE AFTERNOON AS DRY ADVECTION
STRENGTHENS.
HIGHS TODAY ARE FORECAST TO PEAK IN THE UPPER 20S IN MOST
LOCATIONS WITH GRADUALLY MORE SUNSHINE FORECAST IN THE AFTERNOON
AWAY FROM LAKE INDUCED CLOUDS. TONIGHT SHOULD SEE THE SKY CLEAR
IN MOST IF NOT ALL LOCATIONS. HAVE GONE TOWARD COOLER GFS-BASED
MOS GUIDANCE WITH WINDS DROPPING OFF AND SOME LOCATIONS HAVING A
TAD BIT OF FRESH SNOW. SOME UPPER SINGLE DIGITS ARE PROBABLY A
DECENT BET IN FAVORED COOLER LOCATIONS.
MTF
&&
.LONG TERM...
327 AM CST
TUESDAY NIGHT THROUGH SUNDAY...
A SLOW MODERATION CONTINUES TO BE FORECAST MIDWEEK WITH A
DAMPENING UPPER RIDGE SHIFTING EAST OVER THE AREA AND SOUTHWEST
850-1000MB FLOW DEVELOPING UNDERNEATH. THE BLOCKED PATTERN IN THE
WESTERN CONUS IS FORECAST TO BREAK DOWN WITH A STRONG WEST-TO-EAST
PACIFIC JET EXPANDING INTO SOUTHERN CALIFORNIA. A LEADING SHORT
WAVE EJECTING FROM THIS IS EXPECTED TO MOISTEN THE LOW-LEVEL FLOW
INTO THE MISSISSIPPI VALLEY REGION AND THAT STILL IS FORECAST
DURING LATER WEDNESDAY NIGHT INTO THURSDAY. WOULD NOT BE
SURPRISED TO SEE THIS SLOW DOWN A TAD. TEMPERATURES...
THICKNESSES...AND FORECAST PROFILES IN GENERAL STILL LOOK
SUPPORTIVE OF POTENTIALLY LIGHT SNOW OR A WINTRY MIX AT THE
LEADING EDGE OF SATURATED ASCENT.
THE MORE PRONOUNCED LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP
OVER THE CENTRAL PLAINS THURSDAY NIGHT INTO FRIDAY YIELDING DEEPER
MOISTURE TRANSPORT AND MORE WIDESPREAD LIFT WITHIN UPPER
DIFFLUENCE...ALL SUPPORTING LIKELY RAIN AT THIS JUNCTURE. THE LIFT
AND ESPECIALLY MOISTURE IS PRESENTLY NOT FORECAST TO THE MAGNITUDE
OF SEVERAL OF THE HEAVY RAIN DECEMBER SYSTEMS WE SAW...SO QPF IS
PRESENTLY BELOW AN INCH...BUT STILL ONE HALF TO THREE-QUARTERS OF
AN INCH OF RAIN IN JANUARY ON SATURATED GROUND IS NOTEWORTHY AND
SOMETHING WE WILL HAVE TO WATCH. THE 04.00 GFS CONTINUES JUST A
TAD FURTHER EAST AS DOES ITS ENSEMBLE COMPARED TO THE EC. IT WOULD
REQUIRE A FAIRLY LARGE SHIFT TO GET THE STRONGER COLD ADVECTION
WITH THIS SYSTEM GIVEN ITS SOMEWHAT BROAD NATURE...SO STILL FEEL
GOOD NOT MENTIONING ANY WINTERY PRECIPITATION CHANCES THURSDAY
NIGHT THROUGH FRIDAY NIGHT. EVEN DURING THE WEEKEND...WINTRY
PRECIPITATION PRESENTLY LOOKS TO BE LIGHT IF IT WERE TO
MATERIALIZE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* WIND SHIFTING TO THE NORTHEAST THIS AFTERNOON...THEN GRADUALLY
VEERING TO THE SOUTHEAST THIS EVENING...SOUTH TONIGHT...AND
SOUTHWEST TUESDAY.
* FEW LINGERING LAKE EFFECT SNOW SHOWERS INTO THE EARLY AFTERNOON.
BMD
//DISCUSSION...UPDATED 18Z...
LAKE EFFECT SNOW HAS GENERALLY BEEN ON THE DOWNWARD TREND THOUGH
ONE SHOWER JUST UPSTREAM OF ORD COULD STILL BRING BRIEF IFR
CONDITIONS OVER THE NEXT HOUR THROUGH ROUGHLY 18Z WITH PRIMARILY
HIGH END MVFR OR VFR CONDITIONS EXPECTED AFTER 18Z. WINDS HAVE
SHIFTED TO THE NORTHEAST FOR MOST LOCATIONS ACROSS NORTHEASTERN
ILLINOIS WITH ORD BEING ONE OF THE FEW HOLDOUTS WITH A NNW
WIND...THOUGH THAT SHOULD ALSO SWING AROUND TO THE NNE OR NE BY
18-19Z. THEREAFTER...WINDS ARE EXPECTED TO VERY SLOWLY VEER
THROUGH THE PERIOD...BECOMING SOUTHEAST THIS EVENING...SOUTH
TONIGHT...AND EVENTUALLY SOUTHWEST TOMORROW. EXPECT SOME GUSTS
INTO THE HIGH TEENS TO AROUND 20 KT TUESDAY AFTERNOON. CIGS 025-45
ASSOCIATED WITH THE LAKE EFFECT WILL LINGER INTO MID
AFTERNOON...BUT EXPECT THESE TO DISSIPATE AS THE WINDS VEER TO THE
EAST/SOUTHEAST LEAVING VFR CONDITIONS THE REMAINDER OF THE
FORECAST PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WINDS AND GENERAL TIMING.
* MEDIUM CONFIDENCE IN CIGS AND GENERAL TIMING.
* MEDIUM-HIGH CONFIDENCE IN SNOW ENDING
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR/WX NIL.
WEDNESDAY...VFR/WX NIL.
THURSDAY...WINTRY MIX OF PCPN EARLY CHANGING OVER TO RAIN IN THE
AFTERNOON AND CONTINUING THROUGH THE NIGHT. MVFR CIG/VIS
LIKELY...IFR CONDITIONS POSSIBLE.
FRIDAY...RAIN LIKELY THROUGH THE DAY AND CONTINUING OVERNIGHT.
MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SATURDAY...CHANCE OF RAIN THROUGH THE DAY...CHANGING OVER TO SNOW
OVERNIGHT. MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF LINGERING LIGHT SNOW MORNING. MVFR CIG/VIS
POSSIBLE MORNING. OTRW...VFR/WX NIL.
KREIN
&&
.MARINE...
345 AM CST
MAIN MARINE CONCERN IN THE NEAR TERM IS A PERIOD OF NORTHWEST TO
NORTHEAST WINDS OF 20-25 KT WITH OCCASIONAL GUSTS TO 30
KT PRODUCING HAZARDOUS CONDITIONS FOR SMALL CRAFT ALONG BOTH THE
ILLINOIS AND INDIANA NEARSHORE WATERS THROUGH LATE THIS AFTERNOON
OR EARLY EVENING. WINDS WILL DIMINISH FAIRLY QUICKLY THIS EVENING
AS HIGH PRESSURE MOVES ACROSS THE LAKE THIS EVENING AND OVERNIGHT
TONIGHT.
WINDS WILL TURN TO THE SOUTH LATE TODAY NIGHT AS THE HIGH MOVES
OFF TO THE EAST... WITH THESE SOUTH WINDS INCREASING AS THE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A FAIRLY DEEP
AREA OF LOW PRESSURE TRACKING ACROSS HUDSON BAY. WINDS WILL RAMP
UP QUICKLY TO 30 KTS AND BECOME SOUTHWESTERLY ON NORTHERN LAKE
MICHIGAN LATE TONIGHT. A PERIOD OF SOUTHWEST GALES IS LIKELY
ACROSS THE NORTH HALF OF THE LAKE TUESDAY AND TUESDAY NIGHT WHEN
THE PRESSURE GRADIENT IS THE STRONGEST. THE GRADIENT WILL THEN
RELAX A BIT BY EARLY WEDNESDAY...AND WILL EVENTUALLY BACK TO THE
EAST THURSDAY NIGHT AS ANOTHER LOW LIFTS NORTHEAST FROM THE
SOUTHERN PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM MONDAY.
&&
$$
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
1137 AM CST MON JAN 4 2016
.UPDATE...
ISSUED AT 1022 AM CST MON JAN 4 2016
Large hole in the clouds encompasses the entire forecast area at
late morning. However, clouds are spreading southwest from Lake
Michigan, associated with some lake-effect snow showers coming
into the Chicago metro. RAP 925 mb humidity plot shows an increase
in clouds into midday, so have trended the sky grids back to being
partly sunny by early afternoon. Also introduced a few flurries in
the extreme northeast CWA around midday, but this will diminish as
the winds off the lake turn more east-northeast and the showers
diminish.
&&
.SHORT TERM...(Today)
ISSUED AT 339 AM CST MON JAN 4 2016
High pressure over the northern Plains will build into the Great
Lakes area today causing subsidence aloft to help clear out some of
the widespread cloud cover over the region. Nevertheless...a
temperature inversion near 850 mb will trap low level moisture
making it difficult for low cloud cover to dissipate. Forecast is
for mostly cloudy through the morning becoming partly cloudy by
afternoon. A few breaks in cloud cover over the region already this
morning are a good sign there will be at least a few periods of
partial sun for the afternoon. Cold advection today should continue
to keep temperatures cool...near or slightly cooler than
yesterday with highs from around 30 to 35. Winds will start the day
with a light NW breeze 10-15 mph then decrease to N 5-10 mph as the
approaching high pressure center brings a weaker pressure gradient
across the area.
.LONG TERM...(Tonight through Sunday)
ISSUED AT 339 AM CST MON JAN 4 2016
In the short and med range, the forecast is holding rather well,
with very few adjustments here and there. Cool air in place through
today, but overnight tonight and into Tuesday morning, winds taking
on a more southerly fetch and WAA starting to moderate the temps
through the end of the week. Southwesterly flow reestablishes
itself in the midlevels and warmer air filters into the region. A
return of the warmer temperatures will also signal some more
moisture feeding into the Midwest. Models persist in bringing a
short wave into the region for Wed night pops in the west...ahead of
the storm system developing in the SW. Better chances for
precipitation later Thursday through Friday with the main low.
Precip lingering into Saturday still in the SuperBlend, although the
models are speeding up the end of the precip comparatively to the
last run. Guidance temps for Thursday and Friday and into Saturday
are still creeping upward, pointing to a mainly rain event, with the
exception of a mix possible NW of the Illinois River Valley early
Saturday morning and Saturday as colder air pushes around the upper
low...and flurries in the wake of the system Sat night.
Pretty major issues cropping up in the extended btwn the GFS and the
ECMWF solutions. The ECMWF in this past run becoming far more
aggressive with a deep trof over the northern and central Plains,
and a significant amount of much colder air...which will effectively
drop the temps Sat night and Sunday at the very least. Looking into
teleconnections forecast, the AO is trending negative with the
ensembles forecasting more in favor of a negative value next week,
opening the access to the Arctic air. However, between the GFS and
the ensemble outlooks, the trend of the NAO signal to go extremely
negative is lacking. Granted, it has been warmer than normal for
much of the winter thus far, and therefore may not take much,
trendwise, to get that kind of cold air down here. The forecasted
outlooks do trend the NAO down (more amplified pattern over the
country responding to the weaker Icelandic low), but the shift in
the forecast this far out for such a major swing...would prefer to
remain conservative with the shifts until more comfortable with the
new trend of the ECMWF.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1137 AM CST MON JAN 4 2016
Skies cleared earlier this morning over central Illinois, but some
diurnal clouds around 2500 feet are quickly developing from KPIA-
KSPI westward. There are also lake-effect clouds tracking
southwest from the Chicago area. Main question will be how much of
the area is filled in with clouds this afternoon. Model humidity
analysis suggests a continued increase in clouds through 21Z,
before thinning out again after 02-03Z. May be some brief MVFR
conditions as the clouds thicken, but general trend has been for
ceilings quickly going above 3,000 feet. Northerly winds expected
to lighten this evening and trend easterly as high pressure moves
overhead, resulting in south winds prevailing on Tuesday.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Onton
LONG TERM...HJS
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1132 AM CST MON JAN 4 2016
.UPDATE...
842 AM CST
LAKE EFFECT SNOW SHOWERS CONTINUE TO MOVE SOUTH AND SOUTHWEST INTO
NE IL AND NW IN THIS MORNING. MORE INTENSE ECHOES PERIODICALLY
DEVELOP BUT THE BAND HAS PRIMARILY BEEN MADE UP OF LESS INTENSE
REFLECTIVITY. UPSTREAM OBS SHOW SPORADIC VISIBILITY OF 1/2 TO 1
MILE BUT WEBCAMS SHOW LITTLE MORE THAN A DUSTING OF ACCUMULATION
IN MOST AREAS SUGGESTING THE VSBY DROP/PEAK SNOW INTENSITY IS
BRIEF. MORE INTENSE ECHOES ARE STILL OFFSHORE AND WILL BE TRACKING
SOUTHWARD INTO CENTRAL/SOUTHERN COOK AND LAKE AND PORTER COUNTIES
IN INDIANA BETWEEN NOW AND ABOUT 930/10 AM CST. THE CONVERGENCE
MAY BECOME SOMEWHAT STATIONARY OVER NE IL FOR A TIME BUT SNOW
INTENSITY WILL LIKELY EASE. THE WINDOW FOR ACCUMULATION WILL BE
THIS MORNING AND WIND DOWN BY MIDDAY OR SO THOUGH SOME LIGHT SNOW
SHOWERS MAY CONTINUE WITH THE FLOW OFF THE LAKE BUT WITH DECREASED
CONVERGENCE...LESS ORGANIZATION AND LESS FAVORABLE LAKE EFFECT
PARAMETERS TAKING OVER. OVERALL ACCUMS OF A DUSTING TO A FEW
TENTHS IS MOST LIKELY WITH ISOLATED AMOUNTS OF CLOSER TO AN INCH
STILL POSSIBLE...ESPECIALLY GIVEN THAT MORE INTENSE ECHOES ARE
STILL OFFSHORE.
MDB
&&
.SHORT TERM...
327 AM CST
THROUGH TUESDAY...
THE LAKE EFFECT SNOW IN THE FORECAST AREA TODAY STILL LOOKS LIKE
A GOOD POSSIBILITY AND THE MAIN FORECAST CHANGE WAS TO REFINE AND
HONE IN ON THE TIMING AND IMPACTS. REGARDING TIMING...THROUGH A
COMBINATION OF OBSERVATIONAL TRENDS AND HIGH-RESOLUTION GUIDANCE
HAVE SPED UP THE START TIME OF THE SNOW SHOWERS IN FAR NORTHEAST
ILLINOIS AND FAR NORTHWEST INDIANA AND ALSO LIMITED THE SNOW
SHOWER DURATION FROM PREVIOUS FORECAST. THIS DID RESULT IN LESS
AVERAGE FORECAST SNOWFALL TOTALS...THOUGH AS ALWAYS WITH LAKE
EFFECT SNOW SHOWERS THERE CAN BE A HIGH AMOUNT OF VARIABILITY OVER
SPACE. AROUND AN INCH IS FORECAST IN LAKE ADJACENT COUNTIES WITH
THE LIKELY POSSIBILITY OF LESS IN SOME SPOTS AND A LITTLE MORE IN
OTHERS. A DUSTING IS FORECAST IN THE SECOND TIER COUNTIES
SURROUNDING THE SOUTHERN PART OF THE LAKE.
THE UPPER AIR PATTERN EARLY THIS MORNING CONTINUES TO BE ONE OF
REINFORCING COLD AIR ALOFT OVER THE GREAT LAKES...WITH A 130KT DUE
SOUTHWARD POINTING JET ENTERING THE REGION. THE 850MB TEMPERATURES
ARE AROUND -13C OFFERING AROUND AN ESTIMATED 15C DIFFERENCE
BETWEEN THE 850MB AND LAKE SURFACE TEMPERATURES. THIS HAS
RESULTED IN BROAD SNOW SHOWERS ORIENTED INTO LOWER MICHIGAN AND
MAINLY LA PORTE COUNTY INDIANA THUS FAR.
AT THE SURFACE...A COLD FRONT IS ORIENTED NORTHWEST-TO-SOUTHEAST
OVER THE CENTRAL PART OF THE LAKE AHEAD OF AN ARCTIC HIGH THAT
WILL MODIFY AS IT CREEPS SOUTHWARD TODAY. PRESSURE RISES OF
4-5MB/3HR ARE PUSHING THE FRONT SOUTHWARD WITH MORE PRONOUNCED DRY
AIR BEHIND IT. ALONG THE BOUNDARY A LAKE-INDUCED CIRCULATION IS
PRESENT ON RADAR MOSAIC AND WIND STREAMLINE ANALYSIS OFF THE SHORE
OF LUDINGTON MICHIGAN. THIS FEATURE SHOULD CONTINUE SOUTHWARD DOWN
THE LAKE WITH THE SYNOPTIC BOUNDARY EARLY THIS MORNING ASSISTING
IS LOCALIZED CONVERGENCE AND LIKELY BRIEFLY ENHANCING SNOWFALL
RATES ON THE WESTERN FLANK WHICH RIGHT NOW IS EXPECTED TO CLIP FAR
NORTHEAST ILLINOIS AND INTO NORTHWEST INDIANA. A MORE PRONOUNCED
BAND OR COUPLE BANDS ARE STARTING TO DEVELOP UPSTREAM WITH THIS
AND SHOULD CONTINUE TO BETTER DEVELOP GIVEN THE FORECAST
CONVERGENCE AND SUGGESTED SOLUTIONS BY CONVECTIVE ALLOWING
GUIDANCE. LAKE-INDUCED CAPE AT THE LEADING EDGE OF THIS LOOKS TO
BE 100-200 J/KG WITH AN EQUILIBRIUM LEVEL AROUND 8000 FT PER
MODIFIED RAP AND NAM SOUNDINGS. THIS WILL LIKELY SUPPORT A BURST
OF MODERATE TO BRIEFLY HEAVY SNOW SHOWERS FOR SOME LOCATIONS
WHERE THIS COMES INLAND...ARRIVING BETWEEN 9-11 AM CURRENTLY
LOOKS LIKE THE BEST FORECAST TIME. HOWEVER THIS BAND/S/ LOOKS TO
HAVE A SNAKE-LIKE SHAPE AND BE FAIRLY PROGRESSIVE...THUS LIMITING
RESIDENCE TIME IN ANY ONE LOCATION AS THE FRONT AND MESOLOW PUSH
SOUTHWARD. SO WHILE A QUICK INCH OR A LITTLE OVER MAY OCCUR FOR
SOME...AMOUNTS AFTER THAT FIRST HOUR OR SO LOOK TO BE LESS. IT
ALSO LOOKS LIKE THE SNOW SHOULD SQUEEZE IN JUST BEHIND THE MORNING
COMMUTE...HELPING TO MINIMIZE IMPACTS SOME. WILL STILL LIKELY
ISSUE AN SPS JUST FOR THE POTENTIAL FOR A RAPID CHANGE IN
VISIBILITY EVEN IF BRIEF.
GOING INTO THE EARLY-MID AFTERNOON BEHIND THE FRONT...LESS
ORGANIZED SNOW SHOWERS OR FLURRIES WILL REMAIN WITH LIGHT
ADDITIONAL ACCUMULATION AS EQUILIBRIUM HEIGHTS LOWER ON A
STRENGTHENING SUBSIDENCE INVERSION. THE EXCEPTION MAY BE LAKE
COUNTY ILLINOIS AND NORTHERN COOK WHERE SOME CONVERGENCE WITH A
LONG FETCH IS FORECAST...SO RESIDENCE TIME OF LIGHT SNOW COULD
HELP TO YIELD AN ADDITIONAL HALF INCH OR MORE...BUT EVEN THAT
LOOKS TO WEAKEN THROUGH THE AFTERNOON AS DRY ADVECTION
STRENGTHENS.
HIGHS TODAY ARE FORECAST TO PEAK IN THE UPPER 20S IN MOST
LOCATIONS WITH GRADUALLY MORE SUNSHINE FORECAST IN THE AFTERNOON
AWAY FROM LAKE INDUCED CLOUDS. TONIGHT SHOULD SEE THE SKY CLEAR
IN MOST IF NOT ALL LOCATIONS. HAVE GONE TOWARD COOLER GFS-BASED
MOS GUIDANCE WITH WINDS DROPPING OFF AND SOME LOCATIONS HAVING A
TAD BIT OF FRESH SNOW. SOME UPPER SINGLE DIGITS ARE PROBABLY A
DECENT BET IN FAVORED COOLER LOCATIONS.
MTF
&&
.LONG TERM...
327 AM CST
TUESDAY NIGHT THROUGH SUNDAY...
A SLOW MODERATION CONTINUES TO BE FORECAST MIDWEEK WITH A
DAMPENING UPPER RIDGE SHIFTING EAST OVER THE AREA AND SOUTHWEST
850-1000MB FLOW DEVELOPING UNDERNEATH. THE BLOCKED PATTERN IN THE
WESTERN CONUS IS FORECAST TO BREAK DOWN WITH A STRONG WEST-TO-EAST
PACIFIC JET EXPANDING INTO SOUTHERN CALIFORNIA. A LEADING SHORT
WAVE EJECTING FROM THIS IS EXPECTED TO MOISTEN THE LOW-LEVEL FLOW
INTO THE MISSISSIPPI VALLEY REGION AND THAT STILL IS FORECAST
DURING LATER WEDNESDAY NIGHT INTO THURSDAY. WOULD NOT BE
SURPRISED TO SEE THIS SLOW DOWN A TAD. TEMPERATURES...
THICKNESSES...AND FORECAST PROFILES IN GENERAL STILL LOOK
SUPPORTIVE OF POTENTIALLY LIGHT SNOW OR A WINTRY MIX AT THE
LEADING EDGE OF SATURATED ASCENT.
THE MORE PRONOUNCED LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP
OVER THE CENTRAL PLAINS THURSDAY NIGHT INTO FRIDAY YIELDING DEEPER
MOISTURE TRANSPORT AND MORE WIDESPREAD LIFT WITHIN UPPER
DIFFLUENCE...ALL SUPPORTING LIKELY RAIN AT THIS JUNCTURE. THE LIFT
AND ESPECIALLY MOISTURE IS PRESENTLY NOT FORECAST TO THE MAGNITUDE
OF SEVERAL OF THE HEAVY RAIN DECEMBER SYSTEMS WE SAW...SO QPF IS
PRESENTLY BELOW AN INCH...BUT STILL ONE HALF TO THREE-QUARTERS OF
AN INCH OF RAIN IN JANUARY ON SATURATED GROUND IS NOTEWORTHY AND
SOMETHING WE WILL HAVE TO WATCH. THE 04.00 GFS CONTINUES JUST A
TAD FURTHER EAST AS DOES ITS ENSEMBLE COMPARED TO THE EC. IT WOULD
REQUIRE A FAIRLY LARGE SHIFT TO GET THE STRONGER COLD ADVECTION
WITH THIS SYSTEM GIVEN ITS SOMEWHAT BROAD NATURE...SO STILL FEEL
GOOD NOT MENTIONING ANY WINTERY PRECIPITATION CHANCES THURSDAY
NIGHT THROUGH FRIDAY NIGHT. EVEN DURING THE WEEKEND...WINTRY
PRECIPITATION PRESENTLY LOOKS TO BE LIGHT IF IT WERE TO
MATERIALIZE.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* WIND SHIFTING TO THE NORTHEAST THIS AFTERNOON...THEN GRADUALLY
VEERING TO THE SOUTHEAST THIS EVENING...SOUTH TONIGHT...AND
SOUTHWEST TUESDAY.
* FEW LINGERING LAKE EFFECT SNOW SHOWERS INTO THE EARLY AFTERNOON.
BMD
//DISCUSSION...UPDATED 18Z...
LAKE EFFECT SNOW HAS GENERALLY BEEN ON THE DOWNWARD TREND THOUGH
ONE SHOWER JUST UPSTREAM OF ORD COULD STILL BRING BRIEF IFR
CONDITIONS OVER THE NEXT HOUR THROUGH ROUGHLY 18Z WITH PRIMARILY
HIGH END MVFR OR VFR CONDITIONS EXPECTED AFTER 18Z. WINDS HAVE
SHIFTED TO THE NORTHEAST FOR MOST LOCATIONS ACROSS NORTHEASTERN
ILLINOIS WITH ORD BEING ONE OF THE FEW HOLDOUTS WITH A NNW
WIND...THOUGH THAT SHOULD ALSO SWING AROUND TO THE NNE OR NE BY
18-19Z. THEREAFTER...WINDS ARE EXPECTED TO VERY SLOWLY VEER
THROUGH THE PERIOD...BECOMING SOUTHEAST THIS EVENING...SOUTH
TONIGHT...AND EVENTUALLY SOUTHWEST TOMORROW. EXPECT SOME GUSTS
INTO THE HIGH TEENS TO AROUND 20 KT TUESDAY AFTERNOON. CIGS 025-45
ASSOCIATED WITH THE LAKE EFFECT WILL LINGER INTO MID
AFTERNOON...BUT EXPECT THESE TO DISSIPATE AS THE WINDS VEER TO THE
EAST/SOUTHEAST LEAVING VFR CONDITIONS THE REMAINDER OF THE
FORECAST PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WINDS AND GENERAL TIMING.
* MEDIUM CONFIDENCE IN CIGS AND GENERAL TIMING.
* MEDIUM-HIGH CONFIDENCE IN SNOW ENDING
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR/WX NIL.
WEDNESDAY...VFR/WX NIL.
THURSDAY...WINTRY MIX OF PCPN EARLY CHANGING OVER TO RAIN IN THE
AFTERNOON AND CONTINUING THROUGH THE NIGHT. MVFR CIG/VIS
LIKELY...IFR CONDITIONS POSSIBLE.
FRIDAY...RAIN LIKELY THROUGH THE DAY AND CONTINUING OVERNIGHT.
MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SATURDAY...CHANCE OF RAIN THROUGH THE DAY...CHANGING OVER TO SNOW
OVERNIGHT. MVFR CIG/VIS LIKELY...IFR CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF LINGERING LIGHT SNOW MORNING. MVFR CIG/VIS
POSSIBLE MORNING. OTRW...VFR/WX NIL.
KREIN
&&
.MARINE...
345 AM CST
MAIN MARINE CONCERN IN THE NEAR TERM IS A PERIOD OF NORTHWEST TO
NORTHEAST WINDS OF 20-25 KT WITH OCCASIONAL GUSTS TO 30
KT PRODUCING HAZARDOUS CONDITIONS FOR SMALL CRAFT ALONG BOTH THE
ILLINOIS AND INDIANA NEARSHORE WATERS THROUGH LATE THIS AFTERNOON
OR EARLY EVENING. WINDS WILL DIMINISH FAIRLY QUICKLY THIS EVENING
AS HIGH PRESSURE MOVES ACROSS THE LAKE THIS EVENING AND OVERNIGHT
TONIGHT.
WINDS WILL TURN TO THE SOUTH LATE TODAY NIGHT AS THE HIGH MOVES
OFF TO THE EAST... WITH THESE SOUTH WINDS INCREASING AS THE
GRADIENT TIGHTENS BETWEEN THE DEPARTING HIGH AND A FAIRLY DEEP
AREA OF LOW PRESSURE TRACKING ACROSS HUDSON BAY. WINDS WILL RAMP
UP QUICKLY TO 30 KTS AND BECOME SOUTHWESTERLY ON NORTHERN LAKE
MICHIGAN LATE TONIGHT. A PERIOD OF SOUTHWEST GALES IS LIKELY
ACROSS THE NORTH HALF OF THE LAKE TUESDAY AND TUESDAY NIGHT WHEN
THE PRESSURE GRADIENT IS THE STRONGEST. THE GRADIENT WILL THEN
RELAX A BIT BY EARLY WEDNESDAY...AND WILL EVENTUALLY BACK TO THE
EAST THURSDAY NIGHT AS ANOTHER LOW LIFTS NORTHEAST FROM THE
SOUTHERN PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM MONDAY.
&&
$$
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
1022 AM CST MON JAN 4 2016
.UPDATE...
ISSUED AT 1022 AM CST MON JAN 4 2016
Large hole in the clouds encompasses the entire forecast area at
late morning. However, clouds are spreading southwest from Lake
Michigan, associated with some lake-effect snow showers coming
into the Chicago metro. RAP 925 mb humidity plot shows an increase
in clouds into midday, so have trended the sky grids back to being
partly sunny by early afternoon. Also introduced a few flurries in
the extreme northeast CWA around midday, but this will diminish as
the winds off the lake turn more east-northeast and the showers
diminish.
&&
.SHORT TERM...(Today)
ISSUED AT 339 AM CST MON JAN 4 2016
High pressure over the northern Plains will build into the Great
Lakes area today causing subsidence aloft to help clear out some of
the widespread cloud cover over the region. Nevertheless...a
temperature inversion near 850 mb will trap low level moisture
making it difficult for low cloud cover to dissipate. Forecast is
for mostly cloudy through the morning becoming partly cloudy by
afternoon. A few breaks in cloud cover over the region already this
morning are a good sign there will be at least a few periods of
partial sun for the afternoon. Cold advection today should continue
to keep temperatures cool...near or slightly cooler than
yesterday with highs from around 30 to 35. Winds will start the day
with a light NW breeze 10-15 mph then decrease to N 5-10 mph as the
approaching high pressure center brings a weaker pressure gradient
across the area.
.LONG TERM...(Tonight through Sunday)
ISSUED AT 339 AM CST MON JAN 4 2016
In the short and med range, the forecast is holding rather well,
with very few adjustments here and there. Cool air in place through
today, but overnight tonight and into Tuesday morning, winds taking
on a more southerly fetch and WAA starting to moderate the temps
through the end of the week. Southwesterly flow reestablishes
itself in the midlevels and warmer air filters into the region. A
return of the warmer temperatures will also signal some more
moisture feeding into the Midwest. Models persist in bringing a
short wave into the region for Wed night pops in the west...ahead of
the storm system developing in the SW. Better chances for
precipitation later Thursday through Friday with the main low.
Precip lingering into Saturday still in the SuperBlend, although the
models are speeding up the end of the precip comparatively to the
last run. Guidance temps for Thursday and Friday and into Saturday
are still creeping upward, pointing to a mainly rain event, with the
exception of a mix possible NW of the Illinois River Valley early
Saturday morning and Saturday as colder air pushes around the upper
low...and flurries in the wake of the system Sat night.
Pretty major issues cropping up in the extended btwn the GFS and the
ECMWF solutions. The ECMWF in this past run becoming far more
aggressive with a deep trof over the northern and central Plains,
and a significant amount of much colder air...which will effectively
drop the temps Sat night and Sunday at the very least. Looking into
teleconnections forecast, the AO is trending negative with the
ensembles forecasting more in favor of a negative value next week,
opening the access to the Arctic air. However, between the GFS and
the ensemble outlooks, the trend of the NAO signal to go extremely
negative is lacking. Granted, it has been warmer than normal for
much of the winter thus far, and therefore may not take much,
trendwise, to get that kind of cold air down here. The forecasted
outlooks do trend the NAO down (more amplified pattern over the
country responding to the weaker Icelandic low), but the shift in
the forecast this far out for such a major swing...would prefer to
remain conservative with the shifts until more comfortable with the
new trend of the ECMWF.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 517 AM CST MON JAN 4 2016
VFR conditions are likely across the central IL terminals for the
next 24 hours. Ceilings around 4 kft AGL have dissipated early
this morning as a significant clearing has moved across the area.
Additional cloud cover around 4-5 kft AGL will move back into the
area from 15-17Z...but coverage will likely be primarily
scattered. Winds N-NW 5-10 kts becoming light and variable after
02Z.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Onton
LONG TERM...HJS
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS GOODLAND KS
259 PM MST MON JAN 4 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 1245 PM MST MON JAN 4 2016
A RIDGE WILL REMAIN OVER THE PLAINS TONIGHT AND THEN SHIFT EAST
TUESDAY WITH SOUTHWEST FLOW ACROSS THE REGION. SURFACE HIGH PRESSURE
WILL REMAIN OVER THE PLAINS TONIGHT. HIGH PRESSURE WILL MOVE EAST
TUESDAY AS A SURFACE TROUGH MOVES INTO EASTERN COLORADO.
THE FORECAST WILL REMAIN DRY TONIGHT DUE TO SUBSIDENCE. A SHORTWAVE
WILL MOVE ACROSS THE FA TUESDAY BUT FORCING AND MOISTURE ARE BOTH
LACKING. POPS WILL BE NIL TONIGHT AND TUESDAY.
THE HRRR INDICATES THE POSSIBILITY OF SOME PATCHY FREEZING FOG EARLY
TUESDAY MORNING FOR A FEW HOURS NEAR NORTON AND GRAHAM COUNTIES.
CONFIDENCE IS RATHER LOW BUT CANNOT RULE IT OUT. PLAN TO INSERT SOME
PATCHY FREEZING FOG IN THAT AREA.
MIN TEMPERATURES TONIGHT SHOULD FALL BACK TO THE TEENS IN EASTERN
COLORADO WITH LOWER 20S ELSEWHERE. MAX TEMPERATURES TUESDAY SHOULD
REACH THE MID 40S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 157 PM MST MON JAN 4 2016
THE UPPER SHORT WAVE TROUGH WILL CONTINUE TO LIFT OUT ACROSS THE
CENTRAL HIGH PLAINS REGION TUESDAY NIGHT AND WEDNESDAY MORNING
WITH THE SURFACE TROUGH PUSHING FAR ENOUGH EAST THAT PRECIPITATION
ASSOCIATED WITH THE OPEN WAVE WILL LIKELY REMAIN SOUTH AND EAST
OF THE FORECAST AREA. THERE WILL BE BRIEF SHORT WAVE RIDGING ALOFT
WEDNESDAY AND WEDNESDAY NIGHT WITH DRY CONDITIONS.
A SURFACE LOW REDEVELOPS OVER SOUTHEAST COLORADO AHEAD OF THE
NEXT TROUGH THAT MOVES ACROSS THE FORECAST AREA THURSDAY INTO
THURSDAY EVENING. THE SOUTHERLY FETCH OF GULF MOISTURE STREAMING
INTO THE PLAINS STATES TURNS IT`S FOCUS ON THE CENTRAL HIGH PLAINS
WITH A MORE SOUTHEASTERLY FLOW AS THE SURFACE LOW MOVES INTO THE
PANHANDLE REGION. MOISTURE INCREASES IN THE COLUMN THURSDAY...BUT
INITIALLY REMAINS DRYER BETWEEN 850-700MB...SO PRECIPITATION THAT
MOVES INTO THE AREA EARLY THURSDAY MORNING LOOKS LIKE IT MAY START
AS FREEZING DRIZZLE BEFORE SURFACE TEMPERATURES WARM DURING THE
DAY AND THE COLUMN APPROACHES SATURATION AROUND 18Z. THE SURFACE
LOW MOVES INTO SOUTHEAST KANSAS BY THURSDAY NIGHT WITH
TEMPERATURES FALLING AND QUICKLY CHANGING PRECIPITATION OVER TO
ALL SNOW. THE LOW MOVES INTO NORTHERN MISSOURI BY
FRIDAY...BRINGING THE LIGHT SNOW TO AN END FROM WEST TO EAST BY
FRIDAY NIGHT.
BEYOND FRIDAY...MODEL SOLUTIONS FALL OUT OF AGREEMENT. HOWEVER...BOTH
THE ECMWF AND GFS SHOW STRONG SURFACE COLD AIR ADVECTION AS THE
MAIN UPPER FLOW MOVES WELL SOUTH OVER NORTHERN MEXICO...SURFACE
HIGH PRESSURE MOVES INTO THE REGION SATURDAY AND CONTINUES INTO
THE SOUTHERN PLAINS ON SUNDAY. LOW TEMPERATURES IN THE SINGLE
DIGITS...AND POSSIBLY BELOW ZERO...MAY BE OBSERVED THROUGH THE
WEEKEND WITH HIGH TEMPERATURES ONLY REACHING INTO THE UPPER TEENS
TO MIDDLE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1040 AM MST MON JAN 4 2016
VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24
HOURS. THERE IS A SLIGHT CHANCE OF SOME REDUCED FLIGHT CONDITIONS
AT KMCK TOWARD 12Z TUESDAY BUT LEFT OUT OF THE FORECAST DUE TO
UNCERTAINTY. GUSTY SOUTH WINDS ARE EXPECTED IN RESPONSE TO A
SURFACE TROUGH IN EASTERN COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...LOCKHART
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1246 PM MST MON JAN 4 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 1245 PM MST MON JAN 4 2016
A RIDGE WILL REMAIN OVER THE PLAINS TONIGHT AND THEN SHIFT EAST
TUESDAY WITH SOUTHWEST FLOW ACROSS THE REGION. SURFACE HIGH PRESSURE
WILL REMAIN OVER THE PLAINS TONIGHT. HIGH PRESSURE WILL MOVE EAST
TUESDAY AS A SURFACE TROUGH MOVES INTO EASTERN COLORADO.
THE FORECAST WILL REMAIN DRY TONIGHT DUE TO SUBSIDENCE. A SHORTWAVE
WILL MOVE ACROSS THE FA TUESDAY BUT FORCING AND MOISTURE ARE BOTH
LACKING. POPS WILL BE NIL TONIGHT AND TUESDAY.
THE HRRR INDICATES THE POSSIBILITY OF SOME PATCHY FREEZING FOG EARLY
TUESDAY MORNING FOR A FEW HOURS NEAR NORTON AND GRAHAM COUNTIES.
CONFIDENCE IS RATHER LOW BUT CANNOT RULE IT OUT. PLAN TO INSERT SOME
PATCHY FREEZING FOG IN THAT AREA.
MIN TEMPERATURES TONIGHT SHOULD FALL BACK TO THE TEENS IN EASTERN
COLORADO WITH LOWER 20S ELSEWHERE. MAX TEMPERATURES TUESDAY SHOULD
REACH THE MID 40S.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 240 AM MST MON JAN 4 2016
FOR THIS EXTENDED FORECAST PERIOD...THE PRIMARY CONCERNS REMAIN THE
POTENTIAL FOR WINTRY WEATHER THURSDAY INTO FRIDAY AND THE TIMING AND
SIGNIFICANCE OF THE ARCTIC BLASTS THIS WEEKEND AND NEXT WEEK.
OVERALL...THE PREVIOUS FORECASTS ARE FAIRLY SIMILAR TO THE FORECAST
ISSUED WITH THIS PACKAGE. HOWEVER...THERE ARE A FEW KEY SUBTLE
DIFFERENCES THAT HAVE LED TO A FEW CHANGES. MORE DETAILS BELOW.
BEGINNING WITH THURSDAY INTO FRIDAY...THIS IS THE PERIOD THAT
CONTAINS THE WEATHER OF MOST SIGNIFICANCE. A NEGATIVELY TILTED UPPER
LEVEL TROUGH EJECTS OVER THE CENTRAL PLAINS DURING THE DAY THURSDAY.
AS THIS HAPPENS...A SURFACE LOW PRESSURE SHOULD DEVELOP OVER
SOUTHEAST COLORADO AND NORTHEAST NEW MEXICO. THE LOW HEADS EAST...
THEN NORTHEAST TOWARDS WESTERN MISSOURI BY FRIDAY MORNING. AHEAD OF
THE LOW PRESSURE...WARM AIR ADVECTION IS EXPECTED AND A TROWAL MAY
DEVELOP DEPENDING ON HOW ORGANIZED THIS SYSTEM BECOMES. BEHIND THE
LOW...A COLD FRONT IS EXPECTED TO SURGE SOUTH. AS WITH THE PREVIOUS
FEW SYSTEMS...TEMPERATURES WILL BE A CONCERN...ESPECIALLY THURSDAY.
THE WARM AIR ADVECTION AHEAD OF THE SURFACE LOW IS MORE CONCERNING
AS THIS MAY LIMIT FALLING TEMPERATURES. THEREFORE...RAIN AND DRIZZLE
MAY BE THE PRIMARY PRECIPITATION TYPES AHEAD OF THE COLD FRONT WHILE
SNOW SHOULD OCCUR BEHIND THE FRONT. THROUGHOUT THE EVENT...CURRENT
PROJECTIONS ARE THAT THE DENDRITIC LAYER SHOULD BE SATURATED...
REDUCING CHANCE FOR DRIZZLE AND FREEZING DRIZZLE. THIS IS A DECENT
SHIFT IN GUIDANCE FROM PREVIOUS MODEL RUNS WHICH HAD THE DRY AIR
INTRUSION ENTERING THE FORECAST AREA. THIS INTRUSION IS NOW SHOWN
FURTHER SOUTH. DUE TO RUN-TO-RUN VARIABILITY...WAS NOT COMFORTABLE
REMOVING DRIZZLE/FREEZING DRIZZLE FROM THE FORECAST AT THIS TIME.
AS FOR SNOWFALL AMOUNTS...IT IS NOT OUT OF THE REALM OF POSSIBILITY
THAT SOME LOCATIONS COULD OBSERVE A MODERATE/HEAVY SNOW. LATEST
GLOBAL FORECAST RUNS INDICATE A BAND OF PRECIPITATION DEVELOPING
OVER NORTHWEST KANSAS THURSDAY...LIFTING VERY SLOWLY NORTHWEST
THROUGH THURSDAY NIGHT. HOWEVER...WITH THE WARM AIR ADVECTION/TROWAL
OVER THE REGION...MOST OF THE PRECIPITATION MAY FALL AS RAIN AHEAD
OF THE LOW WITH A LATER CHANGE TO SNOW. THIS LIMITS HEAVY SNOWFALL
POTENTIAL. FORECAST CALLS FOR HALF AN INCH TO NEAR TWO INCHES OF
SNOW...SIMILAR TO PREVIOUS FORECAST RUNS. HOWEVER...IF THE COLDER
AIR CAN MOVE SOUTH SOONER...A QUICKER CHANGE TO SNOW WOULD OCCUR AND
THUS...HEAVY SNOWFALL MAY BECOME AN ISSUE. STAY TUNED!
BEYOND FRIDAY...THE MAIN WEATHER STORY BECOMES THE TIMING AND
SIGNIFICANCE OF TWO ARCTIC BLASTS EXPECTED TO IMPACT THE REGION.
REMAIN FAIRLY CONFIDENT IN COLD WEATHER THIS WEEKEND WITH
TEMPERATURES REMAINING WELL BELOW FREEZING. HIGH TEMPERATURES FOR
SATURDAY AND SUNDAY ARE FORECAST TO BE IN THE 20S FOR MOST
LOCATIONS. GUIDANCE BEGINS TO LOSE ITS AGREEMENT BEYOND SUNDAY.
HOWEVER...MOST GUIDANCE HIGHLIGHTS THE POTENTIAL FOR AN OUTBREAK OF
BITTER ARCTIC AIR BY THE MIDDLE OF NEXT WEEK. THE QUESTION OF WHERE
THIS AIR MOVES AND THE TIMING REMAINS. DEPENDING ON THE UPPER LEVEL
PATTERN AND RESULTANT ATMOSPHERIC FLOW...THIS ARCTIC AIR COULD SLIDE
DUE SOUTH ALONG THE ROCKIES AND OVER THE HIGH PLAINS...OR...THE
ARCTIC AIR COULD BE PULLED EAST WITH A DEPARTING LOW PRESSURE SYSTEM
WITH ONLY A BRIEF STINT OF COLD WEATHER LIKELY HERE. IN THE END...
CONFIDENCE IS TOO LOW TO SAY ANYTHING SPECIFIC ON THIS POTENTIAL
OUTBREAK OF ARCTIC AIR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1040 AM MST MON JAN 4 2016
VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24
HOURS. THERE IS A SLIGHT CHANCE OF SOME REDUCED FLIGHT CONDITIONS
AT KMCK TOWARD 12Z TUESDAY BUT LEFT OUT OF THE FORECAST DUE TO
UNCERTAINTY. GUSTY SOUTH WINDS ARE EXPECTED IN RESPONSE TO A
SURFACE TROUGH IN EASTERN COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...RRH
AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1240 PM EST MON JAN 4 2016
.UPDATE...
ISSUED AT 1240 PM EST MON JAN 4 2016
CONTINUING TO SEE AREAS OF SNOW SHOWERS MOVING SOUTHEAST ACROSS
PORTION OF EASTERN KY THIS AFTERNOON. THESE SHOWERS WILL PRODUCE
QUICK BURSTS OF SNOW THAT WILL REDUCE THE VISIBILITY AND BRING A
QUICK DUSTING OF SNOW. GIVEN THE TIME OF DAY AND THE SCATTERED TO
ISOLATED NATURE THE SUN WILL QUICKLY MELT THE SNOW THAT HAS
FALLEN. EXPECTING MUCH OF THIS SNOW SHOWER ACTIVITY TO DECLINE
THROUGH THE AFTERNOON...AS HIGH PRESSURE SHIFTS EAST AND CUTS OFF
THE GREAT LAKES MOISTURE SOURCE. OUTSIDE OF THESE SNOW SHOWERS
EXPECT PARTLY SUNNY TO MOSTLY CLOUDY SKIES AT TIMES. UPDATED POPS
AND TEMP/DEW/WINDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 1020 AM EST MON JAN 4 2016
PORTIONS OF THE REGION CONTINUE TO SEE SOME SNOW SHOWERS/SQUALLS
MOVING THROUGH THE REGION...MAINLY ACROSS THE FAR EAST AND
SOUTHEAST THIS HOUR. MANY REPORTS FROM SOCIAL MEDIA SHOWING SNOW
COVERED ROADS AND QUICKLY REDUCING VIS. THEREFORE WE HAVE
MAINTAINED SPS PRODUCTS TO COVER THESE. THERE IS ALSO ANOTHER
AREA OF SNOW SHOWERS MOVING THROUGH THE NW PORTIONS OF THE CWA.
THERE IS SOME MORE ACTIVITY UPSTREAM IN INDIANA...BUT SEEMS
UNLIKELY AT THIS POINT THESE WILL BE ABLE TO SUSTAIN AND MAKE IT
INTO THE REGION. THE MODELS ARE HAVING A TOUGH TIME GIVEN THE TYPE
OF EVENT...BUT IN GENERAL THE STORM SCALE MODELS SEEM TO BE DOING
THE BEST THUS FAR. WILL CONTINUE WITH THE NOTION OF REDUCTION IN
COVERAGE AS WE MOVE THROUGH THE AFTERNOON...THEREFORE NOT MUCH
CHANGE TO THE OVERALL FORECAST AT THIS POINT. THOSE OUTSIDE OF
THESE SNOW SHOWERS EXPECT FLURRIES TO MOSTLY CLOUDY SKIES. MADE
SOME MINOR ADJUSTMENTS TO TEMPS/DEWS/WINDS TO ACCOUNT FOR LATEST
OBS.
UPDATE ISSUED AT 755 AM EST MON JAN 4 2016
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT RADAR TRENDS AND
OBSERVATIONS. SOME SQUALLS HAVE BROUGHT A QUARTER OF AN INCH
QUICKLY IN SOME LOCATIONS AND SOME WIND GUSTS AS WELL. WE WILL
CONTINUE TO HIGHLIGHT THESE IN THE HWO...AND SPS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 412 AM EST MON JAN 4 2016
A FEW FLURRIES HAVE OCCURRED EARLIER HERE AT JKL...ALTHOUGH
NOTHING IS FALLING AT PRESENT. A FEW FLURRIES WERE REPORTED IN
EASTERN POWELL COUNTY AND IN BELL COUNTY OVERNIGHT. PER RECENT
RADAR RETURNS FLURRIES OR LIGHT SNOW SHOWERS ARE PROBABLY
OCCURRING IN THE BIG SANDY REGION AND NEAR INTERSTATE 64...BUT WE
HAVE NOT HAD ANY GROUND TRUTH REPORTS OF THAT FROM THAT AREA THUS
FAR. MORE SIGNIFICANT SNOW SHOWERS OR EVEN A FEW SNOW SQUALLS ARE
CURRENTLY UPSTREAM OVER SOUTHWESTERN OH AND EASTERN INDIANA AND
POISED TO DROP INTO EASTERN KY TODAY. UP TO A HALF OF AN INCH HAS
RECENTLY BEEN REPORTED FROM THE SNOW SHOWERS IN SOUTHWESTERN OH.
THE MAIN FORECAST CHALLENGE IN THE NEAR TERM IS THE SNOW SHOWERS
AND A FEW SNOW SQUALLS ANTICIPATED TODAY AS THE COLD FRONT AND AN
UPPER LEVEL DISTURBANCE WORK INTO AND ACROSS THE REGION AND THE
COMBINATION OF SOLAR INSOLATION AND COLDER AIR WORKING IN ALOFT
STEEPENS LAPSE RATES. THERE REMAINS MODEL UNCERTAINTY WITH THESE
AS THE NAM AND GFS HAVE EITHER ONE OR TWO LOCATIONS WHERE SNOW
SHOWERS SHOULD BE MOST PREVALENT AS DOES THE RECENT RAP RUNS. THE
0Z NAM AND THE 0Z GFS AS DOES THE 6Z NAM AS A MAX NEAR THE
INTERSTATE 75 CORRIDOR AND ANOTHER OVER THE NORTHERN TO EASTERN
PART OF THE CWA. THE RECENT RAP RUNS HAVE THE MAX GENERALLY FORM
ELLIOTT COUNTY TO MAGOFFIN COUNTY TO LETCHER COUNTY. WIDESPREAD
FLURRIES AND LIGHT SNOW SHOWERS ARE A CERTAINTY TODAY...WITH A FEW
LOCATIONS PICKING UP SNOW SQUALLS WITH GUSTS TO 20 MPH OR MORE AND
QUICK QUARTER OF AN INCH OR EVEN MULTIPLE SNOW SQUALLS. THE NNW
FLOW WOULD GENERALLY FAVOR THE HIGH TERRAIN OF SOUTHEASTERN KY IN
MOST INSTANCES FOR THE GREATEST ACCUMULATION AND OF COURSE
LOCATIONS THAT PICK UP MULTIPLE SNOW SQUALLS. MOST LOCATIONS WILL
PROBABLY NOT PICK UP MUCH MORE THAN A QUARTER OF AN INCH...ALTHOUGH
SOME OF THE HIGHER TERRAIN IN THE SOUTHEAST AND ANY LOCATIONS THAT
EXPERIENCE MULTIPLE SNOW SQUALLS MAY GET OVER A HALF OF AN INCH.
AN SPS WAS REFRESHED HIGHLIGHTING THIS. THE SNOW SHOWERS AND
SQUALLS SHOULD BE MOST PREVALENT DURING THE MORNING TO EARLY
AFTERNOON...AND THEN BEGIN TO WANE AS DRIER AIR FILTERS IN AT THE
LOW LEVELS. TEMPERATURES SHOULD ONLY HAVE A LIMITED RISE DURING
THE DAY TODAY.
SFC HIGH PRESSURE BUILDING IN BEHIND THE FRONT SHOULD SET THE
STAGE FOR CHILLY OVERNIGHT LOWS TONIGHT AND BELOW NORMAL
TEMPERATURES AGAIN ON TUESDAY. THERE REMAINS SOME UNCERTAINTY IN
HOW QUICKLY VALLEY LOCATIONS CAN DECOUPLE AND STRATOCU DISSIPATE...
BUT ADVECTION ALONE SHOULD BRING TEMPERATURES INTO THE TEENS IN
ALL AREAS. READINGS IN THE NORMALLY COLDER VALLEYS COULD BE A
COUPLE OF DEGREES BELOW THE CURRENT FORECAST IF DECOUPLING AND OR
CLEARING IS QUICKER. THESE WIDESPREAD READINGS IN THE TEEN SHOULD
BE THE COLDEST MOST LOCATIONS HAVE BEEN IN THE PAST 10 MONTHS OR
SO...SINCE MARCH 6 OR MARCH 7 OF 2015. TUESDAY SHOULD BE MOSTLY
SUNNY TO SUNNY WITH A FEW PASSING CIRRUS IN THE AFTERNOON...AND
FEATURE HIGHS IN THE 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM EST MON JAN 4 2016
THE EXTENDED PERIOD OF THE FORECAST WILL FEATURE A PERIOD OF DRY AND
WARMER THAN NORMAL WEATHER WEDNESDAY AND MOST OF THURSDAY. THE WARM
WEATHER WILL CONTINUE THROUGH THE UPCOMING WEEKEND...BUT A COUPLE OF
PASSING WEATHER SYSTEM WILL BRING CHANCES OF RAIN TO THE AREA FROM
THURSDAY EVENING ONWARD. THE BEST CHANCE OF RAIN WILL BE FROM
THURSDAY NIGHT THROUGH FRIDAY...AS WELL DEVELOPED AREA OF LOW
PRESSURE MOVES ACROSS THE MID MISSISSIPPI VALLEY AND INTO THE GREAT
LAKES THURSDAY NIGHT AND FRIDAY. THE MODELS WERE IN PRETTY GOOD
AGREEMENT WITH THIS FIRST WEATHER SYSTEM...SO LIKELY POPS SEEMED
REASONABLE FOR THE THURSDAY NIGHT FRIDAY TIME FRAME...WITH A GRADUAL
DECREASE IN RAIN CHANCES FRIDAY NIGHT AND SATURDAY. DECIDED TO KEEP
THE RAIN CHANCES IN PLAY FOR SATURDAY AND SATURDAY NIGHT TO ACCOUNT
FOR THE PRESENCE OF WHAT APPEARS TO BE A WEAK SURFACE BOUNDARY THAT
THE ECMWF MODEL IS KEEPING IN PLACE ACROSS CENTRAL KENTUCKY AND
WESTERN TENNESSEE. A SECOND DISTURBANCE IS FORECAST TO PASS THROUGH
THE REGION SUNDAY AND SUNDAY NIGHT...BUT THE MODELS ARE IN POOR
AGREEMENT AS TO THE EXACT TRACK OF THIS SYSTEM. THE GFS HAS THE
WEEKEND LOW PRESSURE MOVING BY FAR ENOUGH TO OUR SOUTH AND SOUTHEAST
TO KEEP THE AREA MOSTLY DRY...WHILE THE ECMWF MODEL TAKES THE SAME
LOW ACROSS CENTRAL KENTUCKY AND INTO THE OHIO VALLEY. THE ECMWF
SCENARIO WOULD BRING ANOTHER GOOD CHANCE OF RAIN TO THE AREA...WHILE
THE GFS WOULD GIVE US LITTLE IF ANY PRECIPITATION. THAT BEING
SAID...DECIDED TO SIDE MORE WITH THE ECMWF MODEL FOR THE END OF THE
PERIOD AND GOING WITH SMALL RAIN CHANCES TO FINISH OUT THE WEEKEND.
TEMPERATURES LATE SUNDAY NIGHT MAY GET CLOSE ENOUGH TO FREEZING TO
ALLOW A FEW FLAKES OF SNOW TO MIX IN WITH ANY RAIN THAT FALLS.
DAY TIME HIGHS DURING THE PERIOD ARE EXPECTED TO TOP OUT IN THE 50S
THURSDAY THROUGH SATURDAY...AND IN THE 40S ON WEDNESDAY AND SUNDAY.
OVERNIGHT LOWS WILL VARY GREATLY DUE TO THE PASSAGE OF THE TWO
AFOREMENTIONED WEATHER SYSTEMS. THE COLDEST AIR OF THE WINTER SEASON
IS EXPECTED TO SETTLE OVER THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING...AS A POLAR AIR MASS SETTLES OVER THE OHIO AND TENNESSEE
VALLEY REGIONS. MINIMUM TEMPERATURES ON WEDNESDAY MORNING ARE
EXPECTED TO DROP INTO THE TEENS AREA WIDE...WITH OUR VALLEY
LOCATIONS PERHAPS SEEING THE LOW TO MID TEENS. WEDNESDAY NIGHT WILL
SEE A SLIGHT WARM UP AS THE AIR MASS MODIFIES A BIT BENEATH MOSTLY
SUNNY SKIES DURING THE DAY. LOWS WEDNESDAY NIGHT ARE FORECAST TO
ONLY FALL INTO THE UPPER 20S. WE SHOULD SEE LOWS GENERALLY IN THE
LOWER 40S THURSDAY NIGHT THROUGH SATURDAY NIGHT AS WINDS SHIFT
AROUND TO THE SOUTH AND CLOUD COVER OVERSPREADS THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1225 PM EST MON JAN 4 2016
SNOW SHOWERS HAVE BEEN THE BIGGEST ISSUE TAF WISE THUS FAR AND
WILL REMAIN A NUISANCE THROUGH THE AFTERNOON. THESE ARE BEING
AIDED BY GREAT LAKES MOISTURE...SHORTWAVE...AND UPSLOPE FLOW.
GENERALLY MOST SITES ARE RUNNING VFR WITH OCCASIONAL DROPS TO
MVFR. RIGHT NOW WILL KEEP VFR FOR MOST THROUGH THE TAF
PERIOD...GIVEN THE SCATTERED TO ISOLATED NATURE OF THESE SHOWERS.
THESE SHOWERS WILL CONTINUE TO LESSEN IN COVERAGE THROUGH THE DAY
AS MOISTURE SOURCE BECOMES CUTOFF BY BUILDING HIGH PRESSURE. THIS
WILL ALSO USHER IN CLEARING SKIES TONIGHT AND VFR TAFS SHOULD
REMAIN THE STORY. THE WINDS WILL GENERALLY REMAIN LIGHT OUTSIDE OF
THE HEAVIER SNOW SHOWERS WHERE 15 TO 20 KNOT GUST ARE POSSIBLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...JP
LONG TERM...AR
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1225 PM EST MON JAN 4 2016
.UPDATE...
ISSUED AT 1020 AM EST MON JAN 4 2016
PORTIONS OF THE REGION CONTINUE TO SEE SOME SNOW SHOWERS/SQUALLS
MOVING THROUGH THE REGION...MAINLY ACROSS THE FAR EAST AND
SOUTHEAST THIS HOUR. MANY REPORTS FROM SOCIAL MEDIA SHOWING SNOW
COVERED ROADS AND QUICKLY REDUCING VIS. THEREFORE WE HAVE
MAINTAINED SPS PRODUCTS TO COVER THESE. THERE IS ALSO ANOTHER
AREA OF SNOW SHOWERS MOVING THROUGH THE NW PORTIONS OF THE CWA.
THERE IS SOME MORE ACTIVITY UPSTREAM IN INDIANA...BUT SEEMS
UNLIKELY AT THIS POINT THESE WILL BE ABLE TO SUSTAIN AND MAKE IT
INTO THE REGION. THE MODELS ARE HAVING A TOUGH TIME GIVEN THE TYPE
OF EVENT...BUT IN GENERAL THE STORM SCALE MODELS SEEM TO BE DOING
THE BEST THUS FAR. WILL CONTINUE WITH THE NOTION OF REDUCTION IN
COVERAGE AS WE MOVE THROUGH THE AFTERNOON...THEREFORE NOT MUCH
CHANGE TO THE OVERALL FORECAST AT THIS POINT. THOSE OUTSIDE OF
THESE SNOW SHOWERS EXPECT FLURRIES TO MOSTLY CLOUDY SKIES. MADE
SOME MINOR ADJUSTMENTS TO TEMPS/DEWS/WINDS TO ACCOUNT FOR LATEST
OBS.
UPDATE ISSUED AT 755 AM EST MON JAN 4 2016
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT RADAR TRENDS AND
OBSERVATIONS. SOME SQUALLS HAVE BROUGHT A QUARTER OF AN INCH
QUICKLY IN SOME LOCATIONS AND SOME WIND GUSTS AS WELL. WE WILL
CONTINUE TO HIGHLIGHT THESE IN THE HWO...AND SPS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 412 AM EST MON JAN 4 2016
A FEW FLURRIES HAVE OCCURRED EARLIER HERE AT JKL...ALTHOUGH
NOTHING IS FALLING AT PRESENT. A FEW FLURRIES WERE REPORTED IN
EASTERN POWELL COUNTY AND IN BELL COUNTY OVERNIGHT. PER RECENT
RADAR RETURNS FLURRIES OR LIGHT SNOW SHOWERS ARE PROBABLY
OCCURRING IN THE BIG SANDY REGION AND NEAR INTERSTATE 64...BUT WE
HAVE NOT HAD ANY GROUND TRUTH REPORTS OF THAT FROM THAT AREA THUS
FAR. MORE SIGNIFICANT SNOW SHOWERS OR EVEN A FEW SNOW SQUALLS ARE
CURRENTLY UPSTREAM OVER SOUTHWESTERN OH AND EASTERN INDIANA AND
POISED TO DROP INTO EASTERN KY TODAY. UP TO A HALF OF AN INCH HAS
RECENTLY BEEN REPORTED FROM THE SNOW SHOWERS IN SOUTHWESTERN OH.
THE MAIN FORECAST CHALLENGE IN THE NEAR TERM IS THE SNOW SHOWERS
AND A FEW SNOW SQUALLS ANTICIPATED TODAY AS THE COLD FRONT AND AN
UPPER LEVEL DISTURBANCE WORK INTO AND ACROSS THE REGION AND THE
COMBINATION OF SOLAR INSOLATION AND COLDER AIR WORKING IN ALOFT
STEEPENS LAPSE RATES. THERE REMAINS MODEL UNCERTAINTY WITH THESE
AS THE NAM AND GFS HAVE EITHER ONE OR TWO LOCATIONS WHERE SNOW
SHOWERS SHOULD BE MOST PREVALENT AS DOES THE RECENT RAP RUNS. THE
0Z NAM AND THE 0Z GFS AS DOES THE 6Z NAM AS A MAX NEAR THE
INTERSTATE 75 CORRIDOR AND ANOTHER OVER THE NORTHERN TO EASTERN
PART OF THE CWA. THE RECENT RAP RUNS HAVE THE MAX GENERALLY FORM
ELLIOTT COUNTY TO MAGOFFIN COUNTY TO LETCHER COUNTY. WIDESPREAD
FLURRIES AND LIGHT SNOW SHOWERS ARE A CERTAINTY TODAY...WITH A FEW
LOCATIONS PICKING UP SNOW SQUALLS WITH GUSTS TO 20 MPH OR MORE AND
QUICK QUARTER OF AN INCH OR EVEN MULTIPLE SNOW SQUALLS. THE NNW
FLOW WOULD GENERALLY FAVOR THE HIGH TERRAIN OF SOUTHEASTERN KY IN
MOST INSTANCES FOR THE GREATEST ACCUMULATION AND OF COURSE
LOCATIONS THAT PICK UP MULTIPLE SNOW SQUALLS. MOST LOCATIONS WILL
PROBABLY NOT PICK UP MUCH MORE THAN A QUARTER OF AN INCH...ALTHOUGH
SOME OF THE HIGHER TERRAIN IN THE SOUTHEAST AND ANY LOCATIONS THAT
EXPERIENCE MULTIPLE SNOW SQUALLS MAY GET OVER A HALF OF AN INCH.
AN SPS WAS REFRESHED HIGHLIGHTING THIS. THE SNOW SHOWERS AND
SQUALLS SHOULD BE MOST PREVALENT DURING THE MORNING TO EARLY
AFTERNOON...AND THEN BEGIN TO WANE AS DRIER AIR FILTERS IN AT THE
LOW LEVELS. TEMPERATURES SHOULD ONLY HAVE A LIMITED RISE DURING
THE DAY TODAY.
SFC HIGH PRESSURE BUILDING IN BEHIND THE FRONT SHOULD SET THE
STAGE FOR CHILLY OVERNIGHT LOWS TONIGHT AND BELOW NORMAL
TEMPERATURES AGAIN ON TUESDAY. THERE REMAINS SOME UNCERTAINTY IN
HOW QUICKLY VALLEY LOCATIONS CAN DECOUPLE AND STRATOCU DISSIPATE...
BUT ADVECTION ALONE SHOULD BRING TEMPERATURES INTO THE TEENS IN
ALL AREAS. READINGS IN THE NORMALLY COLDER VALLEYS COULD BE A
COUPLE OF DEGREES BELOW THE CURRENT FORECAST IF DECOUPLING AND OR
CLEARING IS QUICKER. THESE WIDESPREAD READINGS IN THE TEEN SHOULD
BE THE COLDEST MOST LOCATIONS HAVE BEEN IN THE PAST 10 MONTHS OR
SO...SINCE MARCH 6 OR MARCH 7 OF 2015. TUESDAY SHOULD BE MOSTLY
SUNNY TO SUNNY WITH A FEW PASSING CIRRUS IN THE AFTERNOON...AND
FEATURE HIGHS IN THE 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM EST MON JAN 4 2016
THE EXTENDED PERIOD OF THE FORECAST WILL FEATURE A PERIOD OF DRY AND
WARMER THAN NORMAL WEATHER WEDNESDAY AND MOST OF THURSDAY. THE WARM
WEATHER WILL CONTINUE THROUGH THE UPCOMING WEEKEND...BUT A COUPLE OF
PASSING WEATHER SYSTEM WILL BRING CHANCES OF RAIN TO THE AREA FROM
THURSDAY EVENING ONWARD. THE BEST CHANCE OF RAIN WILL BE FROM
THURSDAY NIGHT THROUGH FRIDAY...AS WELL DEVELOPED AREA OF LOW
PRESSURE MOVES ACROSS THE MID MISSISSIPPI VALLEY AND INTO THE GREAT
LAKES THURSDAY NIGHT AND FRIDAY. THE MODELS WERE IN PRETTY GOOD
AGREEMENT WITH THIS FIRST WEATHER SYSTEM...SO LIKELY POPS SEEMED
REASONABLE FOR THE THURSDAY NIGHT FRIDAY TIME FRAME...WITH A GRADUAL
DECREASE IN RAIN CHANCES FRIDAY NIGHT AND SATURDAY. DECIDED TO KEEP
THE RAIN CHANCES IN PLAY FOR SATURDAY AND SATURDAY NIGHT TO ACCOUNT
FOR THE PRESENCE OF WHAT APPEARS TO BE A WEAK SURFACE BOUNDARY THAT
THE ECMWF MODEL IS KEEPING IN PLACE ACROSS CENTRAL KENTUCKY AND
WESTERN TENNESSEE. A SECOND DISTURBANCE IS FORECAST TO PASS THROUGH
THE REGION SUNDAY AND SUNDAY NIGHT...BUT THE MODELS ARE IN POOR
AGREEMENT AS TO THE EXACT TRACK OF THIS SYSTEM. THE GFS HAS THE
WEEKEND LOW PRESSURE MOVING BY FAR ENOUGH TO OUR SOUTH AND SOUTHEAST
TO KEEP THE AREA MOSTLY DRY...WHILE THE ECMWF MODEL TAKES THE SAME
LOW ACROSS CENTRAL KENTUCKY AND INTO THE OHIO VALLEY. THE ECMWF
SCENARIO WOULD BRING ANOTHER GOOD CHANCE OF RAIN TO THE AREA...WHILE
THE GFS WOULD GIVE US LITTLE IF ANY PRECIPITATION. THAT BEING
SAID...DECIDED TO SIDE MORE WITH THE ECMWF MODEL FOR THE END OF THE
PERIOD AND GOING WITH SMALL RAIN CHANCES TO FINISH OUT THE WEEKEND.
TEMPERATURES LATE SUNDAY NIGHT MAY GET CLOSE ENOUGH TO FREEZING TO
ALLOW A FEW FLAKES OF SNOW TO MIX IN WITH ANY RAIN THAT FALLS.
DAY TIME HIGHS DURING THE PERIOD ARE EXPECTED TO TOP OUT IN THE 50S
THURSDAY THROUGH SATURDAY...AND IN THE 40S ON WEDNESDAY AND SUNDAY.
OVERNIGHT LOWS WILL VARY GREATLY DUE TO THE PASSAGE OF THE TWO
AFOREMENTIONED WEATHER SYSTEMS. THE COLDEST AIR OF THE WINTER SEASON
IS EXPECTED TO SETTLE OVER THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING...AS A POLAR AIR MASS SETTLES OVER THE OHIO AND TENNESSEE
VALLEY REGIONS. MINIMUM TEMPERATURES ON WEDNESDAY MORNING ARE
EXPECTED TO DROP INTO THE TEENS AREA WIDE...WITH OUR VALLEY
LOCATIONS PERHAPS SEEING THE LOW TO MID TEENS. WEDNESDAY NIGHT WILL
SEE A SLIGHT WARM UP AS THE AIR MASS MODIFIES A BIT BENEATH MOSTLY
SUNNY SKIES DURING THE DAY. LOWS WEDNESDAY NIGHT ARE FORECAST TO
ONLY FALL INTO THE UPPER 20S. WE SHOULD SEE LOWS GENERALLY IN THE
LOWER 40S THURSDAY NIGHT THROUGH SATURDAY NIGHT AS WINDS SHIFT
AROUND TO THE SOUTH AND CLOUD COVER OVERSPREADS THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1225 PM EST MON JAN 4 2016
SNOW SHOWERS HAVE BEEN THE BIGGEST ISSUE TAF WISE THUS FAR AND
WILL REMAIN A NUISANCE THROUGH THE AFTERNOON. THESE ARE BEING
AIDED BY GREAT LAKES MOISTURE...SHORTWAVE...AND UPSLOPE FLOW.
GENERALLY MOST SITES ARE RUNNING VFR WITH OCCASIONAL DROPS TO
MVFR. RIGHT NOW WILL KEEP VFR FOR MOST THROUGH THE TAF
PERIOD...GIVEN THE SCATTERED TO ISOLATED NATURE OF THESE SHOWERS.
THESE SHOWERS WILL CONTINUE TO LESSEN IN COVERAGE THROUGH THE DAY
AS MOISTURE SOURCE BECOMES CUTOFF BY BUILDING HIGH PRESSURE. THIS
WILL ALSO USHER IN CLEARING SKIES TONIGHT AND VFR TAFS SHOULD
REMAIN THE STORY. THE WINDS WILL GENERALLY REMAIN LIGHT OUTSIDE OF
THE HEAVIER SNOW SHOWERS WHERE 15 TO 20 KNOT GUST ARE POSSIBLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...JP
LONG TERM...AR
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 PM EST MON JAN 4 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 359 PM EST MON JAN 4 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THAT THE TROF THAT DROPPED
INTO THE GREAT LAKES REGION OVER THE WEEKEND IS WEAKENING AND
QUICKLY SHIFTING INTO NEW ENGLAND IN RESPONSE TO A STRONG RIDGE
MOVING OUT OVER THE PLAINS AND SCNTRL CANADA. 12HR 500MB HEIGHT
RISES WERE 90M/160M AT KINL/CWPL RESPECTIVELY AT 12Z TODAY. THE
ASSOCIATED SFC HIGH PRES RIDGE IS ALREADY EXITING TO THE E OF THE
FCST AREA AND SW RETURN FLOW IS RAPIDLY INCREASING TO THE W AND NW
IN THE TIGHTENING PRES GRADIENT BTWN THE DEPARTING RIDGE AND LOW
PRES APPROACHING HUDSON BAY. AS A RESULT...LINGERING/DIMINISHING LES
OFF LAKE SUPERIOR HAS MOSTLY SHIFTED OFFSHORE EARLY THIS AFTN WITH
ONLY A FEW RESIDUAL FLURRIES OVER THE NCNTRL. FLURRIES HAVE ALSO
MOVED ONSHORE AROUND MENOMINEE AS WINDS VEER OVER NRN LAKE MI.
A QUIET SHORT TERM PORTION OF THE FCST IS SHAPING UP...AT LEAST PCPN-
WISE. SW FLOW WILL DOMINATE BTWN THE HIGH PRES RIDGE SHIFTING TO THE
E COAST AND LOW PRES TRACKING ACROSS HUDSON BAY. DESPITE
WAA/ISENTROPIC ASCENT...FCST SOUNDINGS SHOW COLUMN REMAINING VERY
DRY...SO PCPN WON`T BE AN ISSUE UNDER THE WAA REGIME TONIGHT/TUE.
HOWEVER...AS WINDS VEER TO THE SW OVER NRN LAKE MI...SOME FLURRIES
SHOULD BRUSH AREAS NEAR LAKE MI THIS EVENING...AND ONCE THE SW FLOW
LOCKS IN...THE WRN EDGE OF LIGHT LES/FLURRIES MAY OCCASIONALLY
AFFECT SE LUCE COUNTY OVERNIGHT. ELSEHWERE...AN ISSUE TONIGHT/TUE IS
THE POTENTIAL FOR LOW CLOUDS TO DEVELOP AS NAM/RAP SHOW SHALLOW
MOISTENING IN THE NEAR SFC LAYER...THE RAP MUCH SOONER THAN THE NAM.
SFC OBS/3.9 MICRON IMAGERY DO SHOW LOW STRATUS OVER MUCH OF IA INTO
PORTIONS OF SCNTRL MN THIS AFTN. TRAJECTORIES INITIALLY CARRY THIS
STRATUS NORTHWARD...BUT OVER TIME THESE LOW CLOUDS MAY SLIP INTO THE
HIGH TERRAIN OF WRN UPPER MI LATE TONIGHT OR TUE MORNING. WILL WAIT
TO SEE HOW THE STRATUS EVOLVES THIS EVENING WITHIN STRENGTHENING LOW-
LEVEL FLOW BEFORE SHIFTING TO A MUCH MORE PESSIMISTIC SKY COVER FCST
OVER THE HIGHER TERRAIN OF THE W HALF. ON TUE...TIGHT PRES GRADIENT
WILL LEAD TO GUSTY WINDS. LIMITED MIXING DEPTH WILL WORK TO KEEP
WINDS IN CHECK...BUT STILL EXPECT SOME GUSTS TO 30-35MPH OVER THE
HIGHER TERRAIN...DOWNSLOPE AREAS NEAR LAKE SUPERIOR AND DOWNWIND OF
LAKE MICHIGAN.
AS FOR TEMPS...TEMPS WILL HAVE A CHANCE TO FALL INITIALLY THIS
EVENING BEFORE GRADIENT TIGHTENS. TOUGH TO SAY HOW LOW TEMPS WILL
GET...BUT THE FAR E SHOULD HAVE THE BEST CHANCE FOR A QUICK FALL
THIS EVENING BEFORE CLOUDS AND/OR WINDS INCREASE AS THAT AREA IS
CLOSER TO THE DEPARTING HIGH PRES RIDGE. WILL SHOW TEMPS AS LOW AS
AROUND 5F ABOVE IN LUCE COUNTY/PORTIONS OF SCHOOLCRAFT COUNTY.
TRADITIONAL COLD SPOTS OVER THE INTERIOR W SHOULD SLIP JUST BLO 10F.
EXPECT HIGHS ON TUE IN THE MID/UPPER 20S FOR THE MOST PART.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 323 PM EST MON JAN 4 2016
NO SIGNIFICANT WEATHER CONCERNS FOR THE LONG TERM FORECAST...BUT
THERE WILL BE SEVERAL NUISANCE EVENTS THAT COULD LEAD TO OCCASIONAL
PERIODS OF SLIPPERY ROADS.
HIGH PRESSURE WILL BE OVER THE ATLANTIC SEABOARD AT THE START OF
THE LONG TERM PERIOD...WHILE A SHORTWAVE AND SURFACE LOW MOVE
THROUGH SOUTHERN HUDSON BAY. A WEAKENING TROUGH ASSOCIATED WITH THE
LOW WILL BE SLIDING SOUTHEAST TOWARDS THE AREA TUESDAY NIGHT AND
INTO WEDNESDAY (ACROSS NORTHWEST ONTARIO)...EVENTUALLY SETTLING
OVER WESTERN LAKE SUPERIOR. THAT TROUGH WILL REMAIN NEARLY
STATIONARY THROUGH THURSDAY...AS A WEAK SHORTWAVE LIFTS NORTHEAST
ACROSS THE UPPER GREAT LAKES REGION. EXPECT LIMITED PRECIPITATION
ALONG THE FRONT TUESDAY NIGHT INTO WEDNESDAY BEFORE THE SHORTWAVE
MOVES THROUGH...WITH THE BEST CHANCES TIED TO SOME LAKE ENHANCEMENT
NEAR THE KEWEENAW PENINSULA. THE GENERAL IDEA WITH THE HIGHER
RESOLUTION MODELS IS TO KEEP THE TROUGH OVER WESTERN LAKE SUPERIOR
AND THE HEAVIER BAND JUST BRUSHING THE NORTHERN PORTIONS OF
KEWEENAW COUNTY. WILL FOLLOW THAT IDEA WITH THE POPS/SNOW
FORECAST...BUT WILL NEED TO KEEP AN EYE ANY TRENDS TO THE SOUTH AS
THAT WOULD LEAD TO SOME HEAVIER SNOW AFFECTING KEWEENAW COUNTY.
OTHERWISE...EXPECT LOW CLOUDS TO SPREAD INTO THE AREA UNDER THE
STRONG INVERSION JUST ABOVE 900MB TUESDAY EVENING...ASSUMING THEY
DON/T OCCUR BEFORE THAT AS SHOWN ON THE NAM. WITH THE LOW CLOUD
POTENTIAL AND CLOUDS FROM THE TROUGH...SHOULD SEE A MOSTLY CLOUDY
PERIOD TUESDAY NIGHT INTO WEDNESDAY.
PRECIPITATION SHOULD MOVE INTO THE WESTERN U.P. WEDNESDAY
AFTERNOON/EVENING ALONG THE STALLED TROUGH AND ASSOCIATED WITH
INCREASING MOISTURE AND MID LEVEL Q-VECTOR CONVERGENCE WITH THE
SHORTWAVE. WILL LIKELY SEE TWO WAVES...WITH THE FIRST AN ELONGATED
WSW TO ENE AREA OF SNOW STRETCHING ACROSS THE WEST/CENTRAL U.P. AND
ASSOCIATED WITH 850-750MB FGEN FORCING. THE SECOND PUSH ARRIVES
LATE WEDNESDAY NIGHT INTO THURSDAY AS THE SHORTWAVE AND 850-700MB
WARM AIR ADVECTION PUSHES THROUGH. EXPECT ALL OF THIS PRECIP TO
FALL AS SNOW LATE WEDNESDAY AFTERNOON INTO THURSDAY...BUT WITH MUCH
OF THE FORCING BELOW THE DGZ...THINK SNOW-TO-LIQUID RATIOS WILL BE
RIGHT AROUND 10-1 FOR MUCH OF THE EVENT (MAYBE SLIGHTLY LOWER
INITIALLY AND SLIGHTLY HIGHER TOWARDS THE END). THUS...WITH QPF
AMOUNTS OF 0.1 TO 0.25 OVER THE WEST/CENTRAL U.P. WOULD EXPECT
SNOWFALL AMOUNTS AROUND 2 INCHES FOR MUCH OF THE WEST/CENTRAL U.P.
SHOULD SEE A BRIEF BREAK BEFORE THE NEXT WAVE OF LIGHT PRECIPITATION
MOVES NORTHEAST INTO THE AREA FRIDAY INTO SATURDAY AS A WEAK LOW
LIFTS FROM MISSOURI AT 12Z FRIDAY TO JAMES BAY BY 12Z SUNDAY. AT
THIS POINT...IT LOOKS LIKE THE BEST FORCING WILL BE OVER THE EASTERN
U.P. WITH THE BEST PUSH OF SNOW MOVING THROUGH DURING THE DAY ON
FRIDAY (GENERALLY 1-3 INCHES). THERE MAY BE ENOUGH LOW LEVEL WARMING
TO RAISE WETBULB0 HEIGHTS TO LEAD TO A LITTLE BIT OF RAIN MIXING IN
WITH THE SNOW ALONG THE BAY OF GREEN BAY SHORELINE SOUTH OF
ESCANABA...SO DID INCLUDE A SLIGHT CHANCE TO CHANCE OF RAIN THERE.
WHILE THE LOW IS FAIRLY WEAK AND BRINGS SOME LIGHT SNOW FRIDAY
INTO FRIDAY NIGHT...A STRONG WAVE FROM THE ARCTIC WILL BE DIVING
SOUTH ACROSS THE CANADIAN PRAIRIES AND BE MOVING TOWARDS THE GREAT
LAKES REGION FOR THE SECOND HALF OF THE WEEKEND AND FOR EARLY NEXT
WEEK. THAT WILL LEAD TO A SIGNIFICANT TRANSITION IN TEMPERATURES...
FROM THE LOWER 30S FOR THE LATER HALF OF THIS WEEK TO HIGHS IN THE
SINGLE DIGITS TO LOWER TEENS ABOVE ZERO ON MONDAY. THAT COLD AIR
WILL ALSO MARK THE FIRST TIME OUR OFFICE WILL FALL BELOW ZERO SINCE
MARCH 28...2015. THROUGH JANUARY 3...THAT MAKES A 281 DAY STREAK
AND IS CURRENTLY TIED FOR THE 16TH LONGEST STREAK. IF THE CURRENT
FORECAST HOLDS...WE WILL MAKE IT TO AROUND 288 OR 289 DAYS...WHICH
WOULD BE RIGHT AROUND THE 9TH LONGEST STREAK OF TEMPERATURES AT OR
ABOVE ZERO. THAT COLD AIR (850MB TEMPS FALLING TO -24C ON SUNDAY)
WILL KICK THE LAKE EFFECT MACHINE BACK INTO GEAR FOR THE AREA...BUT
THE COLD TEMPERATURES WILL KEEP THE CLOUD GENERALLY ABOVE THE DGZ
LEADING TO SMALLER FLAKES. THAT WILL KEEP SNOWFALL AMOUNTS IN CHECK
AND LIKELY WOULD ONLY SEE ADVISORY AMOUNTS IN THE TRADITIONAL
WEST-NORTHWEST WIND SNOWBELTS. THE GREATER IMPACT WITH THE SMALLER
FLAKES WILL BE THE REDUCED VISIBILITIES...ESPECIALLY IF THERE IS
ENOUGH WIND TO BLOW THE SNOW AROUND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1220 PM EST MON JAN 4 2016
WITH HIGH PRES RIDGE PASSING THIS AFTN...RESULTING IN WINDS VEERING
AROUND TO THE SW...STRATOCU OFF LAKE SUPERIOR/MVFR CIGS WILL SHIFT
OFFSHORE. THIS HAS ALREADY OCCURRED AT KIWD/KCMX...AND EXPECT VFR
CONDITIONS TO PREVAIL AT BOTH TERMINALS THRU THIS FCST PERIOD. AT
KSAW...VFR CONDITIONS WILL DEVELOP BY SUNSET IF NOT SOONER.
INCREASING SW WINDS ABOVE STABLE NEAR SFC LAYER WILL RESULT IN LLWS
TONIGHT AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EST MON JAN 4 2016
TIGHTENING PRES GRADIENT BTWN DEPARTING HIGH PRES RIDGE AND LOW PRES
MOVING OVER HUDSON BAY WILL RESULT IN SW WINDS INCREASING TO GALES
TONIGHT ACROSS LAKE SUPERIOR. THE GALES WILL CONTINUE TUE BEFORE
WINDS BEGIN TO DIMINISH TUE NIGHT. WINDS WILL DIMINISH FURTHER
WED/THU TO MOSTLY UNDER 20KT AS A LOW PRES TROF SETTLES OVER THE
UPPER GREAT LAKES. WINDS WILL INCREASE SOME ON FRI/SAT AS LOW PRES
LIFTS NE INTO THE GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TUESDAY TO 1 AM EST WEDNESDAY FOR
LSZ265>267.
GALE WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 10 PM EST
/9 PM CST/ TUESDAY FOR LSZ162.
GALE WARNING FROM 10 PM THIS EVENING TO 1 AM EST WEDNESDAY FOR
LSZ263-264.
GALE WARNING FROM 6 AM TUESDAY TO 1 AM EST WEDNESDAY FOR LSZ243-
244.
LAKE MICHIGAN...
GALE WARNING FROM 7 AM TUESDAY TO 1 AM EST WEDNESDAY FOR LMZ221-
248-250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
323 PM EST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EST MON JAN 4 2016
WV IMAGERY AND RAP ANALYSIS INDICATED NRLY MID/UPPER LEVEL FLOW
THROUGH THE WRN LAKES BTWN A RIDGE OVER THE PLAINS AND A TROUGH FROM
QUEBEC INTO THE ERN LAKES. STRONG 700-300 MB QVECTOR DIV AND
RESULTING SUBSIDENCE FROM NRN ONTARIO THROUGH LAKE SUPERIOR AND
UPPER MI HAS BROUGHT A DIMINISHING TREND TO THE LES AS THE SHRTWV
THAT MOVED THROUGH LAKE SUPERIOR SUN EVENING MOVES INTO THE ERN
LAKES. ALTHOUGH INVERSION HEIGHTS HAVE DROPPED TO AROUND 4K
FT...INSTABILITY ASSOCIATED WITH 850 MB TEMPS NEAR -18C STILL
SUPPORTED SCT/NMRS LIGHT SNOW SHOWERS IN THE NNE LOW LEVEL FLOW.
TODAY...MID LEVEL AND SFC RIDGING WILL BUILD INTO THE WRN LAKES
TODAY BRINGING AN END TO THE LES THIS MORNING AS INVERSION HEIGHTS
DROP BLO 3K FT AND WINDS BECOME VARIABLE BY MIDDAY. THERE MAY STILL
BE SOME MINOR ADDITIONAL ACCUMULATIONS N CNTRL OF A HALF INCH OR LESS
AFTER 12Z. SW WINDS THIS AFTERNOON WILL HELP BRING SOME
CLEARING. EVEN WITH SOME AFTERNOON SUN...TEMPS WILL REMAIN AT OR
BELOW NORMAL WITH HIGHS AROUND 20. THE COLDEST AIR WILL REMAINED
ENTRENCHED OVER THE EAST NEAR KERY WHERE MAX READINGS REMAIN BLO 15.
TONIGHT...SW WINDS WILL INCREASE AS THE GRADIENT TIGHTENS BETWEEN
THE DEPARTING HIGH AND A TROUGH INTO THE NRN PLAINS. BOUNDARY LAYER
WINDS IN THE 10-20 KNOT RANGE WILL KEEP TEMPS FROM DROPPING OFF TOO
FAR WITH MINS FROM 10 TO 15 INLAND TO AROUND 20 NEAR LAKE SUPERIOR
WHERE DOWNSLOPE FLOW PREVAILS. THE SW WINDS OFF OF LAKE MI WITH 900
MB TEMPS AROUND -10C WILL SUPPORT A BAND OF CLOUDS AND SOME FLURRIES
BUT SHOULD REMAIN TO THE SE OF THE CWA OR JUST CLIP FAR SE LUCE
COUNTY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 323 PM EST MON JAN 4 2016
NO SIGNIFICANT WEATHER CONCERNS FOR THE LONG TERM FORECAST...BUT
THERE WILL BE SEVERAL NUISANCE EVENTS THAT COULD LEAD TO OCCASIONAL
PERIODS OF SLIPPERY ROADS.
HIGH PRESSURE WILL BE OVER THE ATLANTIC SEABOARD AT THE START OF
THE LONG TERM PERIOD...WHILE A SHORTWAVE AND SURFACE LOW MOVE
THROUGH SOUTHERN HUDSON BAY. A WEAKENING TROUGH ASSOCIATED WITH THE
LOW WILL BE SLIDING SOUTHEAST TOWARDS THE AREA TUESDAY NIGHT AND
INTO WEDNESDAY (ACROSS NORTHWEST ONTARIO)...EVENTUALLY SETTLING
OVER WESTERN LAKE SUPERIOR. THAT TROUGH WILL REMAIN NEARLY
STATIONARY THROUGH THURSDAY...AS A WEAK SHORTWAVE LIFTS NORTHEAST
ACROSS THE UPPER GREAT LAKES REGION. EXPECT LIMITED PRECIPITATION
ALONG THE FRONT TUESDAY NIGHT INTO WEDNESDAY BEFORE THE SHORTWAVE
MOVES THROUGH...WITH THE BEST CHANCES TIED TO SOME LAKE ENHANCEMENT
NEAR THE KEWEENAW PENINSULA. THE GENERAL IDEA WITH THE HIGHER
RESOLUTION MODELS IS TO KEEP THE TROUGH OVER WESTERN LAKE SUPERIOR
AND THE HEAVIER BAND JUST BRUSHING THE NORTHERN PORTIONS OF
KEWEENAW COUNTY. WILL FOLLOW THAT IDEA WITH THE POPS/SNOW
FORECAST...BUT WILL NEED TO KEEP AN EYE ANY TRENDS TO THE SOUTH AS
THAT WOULD LEAD TO SOME HEAVIER SNOW AFFECTING KEWEENAW COUNTY.
OTHERWISE...EXPECT LOW CLOUDS TO SPREAD INTO THE AREA UNDER THE
STRONG INVERSION JUST ABOVE 900MB TUESDAY EVENING...ASSUMING THEY
DON/T OCCUR BEFORE THAT AS SHOWN ON THE NAM. WITH THE LOW CLOUD
POTENTIAL AND CLOUDS FROM THE TROUGH...SHOULD SEE A MOSTLY CLOUDY
PERIOD TUESDAY NIGHT INTO WEDNESDAY.
PRECIPITATION SHOULD MOVE INTO THE WESTERN U.P. WEDNESDAY
AFTERNOON/EVENING ALONG THE STALLED TROUGH AND ASSOCIATED WITH
INCREASING MOISTURE AND MID LEVEL Q-VECTOR CONVERGENCE WITH THE
SHORTWAVE. WILL LIKELY SEE TWO WAVES...WITH THE FIRST AN ELONGATED
WSW TO ENE AREA OF SNOW STRETCHING ACROSS THE WEST/CENTRAL U.P. AND
ASSOCIATED WITH 850-750MB FGEN FORCING. THE SECOND PUSH ARRIVES
LATE WEDNESDAY NIGHT INTO THURSDAY AS THE SHORTWAVE AND 850-700MB
WARM AIR ADVECTION PUSHES THROUGH. EXPECT ALL OF THIS PRECIP TO
FALL AS SNOW LATE WEDNESDAY AFTERNOON INTO THURSDAY...BUT WITH MUCH
OF THE FORCING BELOW THE DGZ...THINK SNOW-TO-LIQUID RATIOS WILL BE
RIGHT AROUND 10-1 FOR MUCH OF THE EVENT (MAYBE SLIGHTLY LOWER
INITIALLY AND SLIGHTLY HIGHER TOWARDS THE END). THUS...WITH QPF
AMOUNTS OF 0.1 TO 0.25 OVER THE WEST/CENTRAL U.P. WOULD EXPECT
SNOWFALL AMOUNTS AROUND 2 INCHES FOR MUCH OF THE WEST/CENTRAL U.P.
SHOULD SEE A BRIEF BREAK BEFORE THE NEXT WAVE OF LIGHT PRECIPITATION
MOVES NORTHEAST INTO THE AREA FRIDAY INTO SATURDAY AS A WEAK LOW
LIFTS FROM MISSOURI AT 12Z FRIDAY TO JAMES BAY BY 12Z SUNDAY. AT
THIS POINT...IT LOOKS LIKE THE BEST FORCING WILL BE OVER THE EASTERN
U.P. WITH THE BEST PUSH OF SNOW MOVING THROUGH DURING THE DAY ON
FRIDAY (GENERALLY 1-3 INCHES). THERE MAY BE ENOUGH LOW LEVEL WARMING
TO RAISE WETBULB0 HEIGHTS TO LEAD TO A LITTLE BIT OF RAIN MIXING IN
WITH THE SNOW ALONG THE BAY OF GREEN BAY SHORELINE SOUTH OF
ESCANABA...SO DID INCLUDE A SLIGHT CHANCE TO CHANCE OF RAIN THERE.
WHILE THE LOW IS FAIRLY WEAK AND BRINGS SOME LIGHT SNOW FRIDAY
INTO FRIDAY NIGHT...A STRONG WAVE FROM THE ARCTIC WILL BE DIVING
SOUTH ACROSS THE CANADIAN PRAIRIES AND BE MOVING TOWARDS THE GREAT
LAKES REGION FOR THE SECOND HALF OF THE WEEKEND AND FOR EARLY NEXT
WEEK. THAT WILL LEAD TO A SIGNIFICANT TRANSITION IN TEMPERATURES...
FROM THE LOWER 30S FOR THE LATER HALF OF THIS WEEK TO HIGHS IN THE
SINGLE DIGITS TO LOWER TEENS ABOVE ZERO ON MONDAY. THAT COLD AIR
WILL ALSO MARK THE FIRST TIME OUR OFFICE WILL FALL BELOW ZERO SINCE
MARCH 28...2015. THROUGH JANUARY 3...THAT MAKES A 281 DAY STREAK
AND IS CURRENTLY TIED FOR THE 16TH LONGEST STREAK. IF THE CURRENT
FORECAST HOLDS...WE WILL MAKE IT TO AROUND 288 OR 289 DAYS...WHICH
WOULD BE RIGHT AROUND THE 9TH LONGEST STREAK OF TEMPERATURES AT OR
ABOVE ZERO. THAT COLD AIR (850MB TEMPS FALLING TO -24C ON SUNDAY)
WILL KICK THE LAKE EFFECT MACHINE BACK INTO GEAR FOR THE AREA...BUT
THE COLD TEMPERATURES WILL KEEP THE CLOUD GENERALLY ABOVE THE DGZ
LEADING TO SMALLER FLAKES. THAT WILL KEEP SNOWFALL AMOUNTS IN CHECK
AND LIKELY WOULD ONLY SEE ADVISORY AMOUNTS IN THE TRADITIONAL
WEST-NORTHWEST WIND SNOWBELTS. THE GREATER IMPACT WITH THE SMALLER
FLAKES WILL BE THE REDUCED VISIBILITIES...ESPECIALLY IF THERE IS
ENOUGH WIND TO BLOW THE SNOW AROUND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1220 PM EST MON JAN 4 2016
WITH HIGH PRES RIDGE PASSING THIS AFTN...RESULTING IN WINDS VEERING
AROUND TO THE SW...STRATOCU OFF LAKE SUPERIOR/MVFR CIGS WILL SHIFT
OFFSHORE. THIS HAS ALREADY OCCURRED AT KIWD/KCMX...AND EXPECT VFR
CONDITIONS TO PREVAIL AT BOTH TERMINALS THRU THIS FCST PERIOD. AT
KSAW...VFR CONDITIONS WILL DEVELOP BY SUNSET IF NOT SOONER.
INCREASING SW WINDS ABOVE STABLE NEAR SFC LAYER WILL RESULT IN LLWS
TONIGHT AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EST MON JAN 4 2016
HIGH PRESSURE WILL QUICKLY BUILD ACROSS THE LAKE THIS MORNING AND
THEN QUICKLY MOVE SOUTH OF THE AREA THIS AFTERNOON. BEHIND THE
HIGH...SOUTHWEST WINDS WILL INCREASE TO GALES FORCE TONIGHT INTO TUE
EVENING AHEAD OF THE NEXT FROTNAL SYSTEM. THE GALE WATCH WAS UPGRADED
TO A WARNING FOR THIS PERIOD. THE FRONT STALLS OUT NEAR LAKE SUPERIOR
FOR WED-FRI...LEADING TO WINDS GENERALLY LESS THAN 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TUESDAY TO 1 AM EST WEDNESDAY FOR
LSZ265>267.
GALE WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 10 PM EST
/9 PM CST/ TUESDAY FOR LSZ162.
GALE WARNING FROM 10 PM THIS EVENING TO 1 AM EST WEDNESDAY FOR
LSZ263-264.
GALE WARNING FROM 6 AM TUESDAY TO 1 AM EST WEDNESDAY FOR LSZ243-
244.
LAKE MICHIGAN...
GALE WATCH FROM TUESDAY MORNING THROUGH LATE TUESDAY NIGHT FOR
LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1221 PM EST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EST MON JAN 4 2016
WV IMAGERY AND RAP ANALYSIS INDICATED NRLY MID/UPPER LEVEL FLOW
THROUGH THE WRN LAKES BTWN A RIDGE OVER THE PLAINS AND A TROUGH FROM
QUEBEC INTO THE ERN LAKES. STRONG 700-300 MB QVECTOR DIV AND
RESULTING SUBSIDENCE FROM NRN ONTARIO THROUGH LAKE SUPERIOR AND
UPPER MI HAS BROUGHT A DIMINISHING TREND TO THE LES AS THE SHRTWV
THAT MOVED THROUGH LAKE SUPERIOR SUN EVENING MOVES INTO THE ERN
LAKES. ALTHOUGH INVERSION HEIGHTS HAVE DROPPED TO AROUND 4K
FT...INSTABILITY ASSOCIATED WITH 850 MB TEMPS NEAR -18C STILL
SUPPORTED SCT/NMRS LIGHT SNOW SHOWERS IN THE NNE LOW LEVEL FLOW.
TODAY...MID LEVEL AND SFC RIDGING WILL BUILD INTO THE WRN LAKES
TODAY BRINGING AN END TO THE LES THIS MORNING AS INVERSION HEIGHTS
DROP BLO 3K FT AND WINDS BECOME VARIABLE BY MIDDAY. THERE MAY STILL
BE SOME MINOR ADDITIONAL ACCUMULATIONS N CNTRL OF A HALF INCH OR LESS
AFTER 12Z. SW WINDS THIS AFTERNOON WILL HELP BRING SOME
CLEARING. EVEN WITH SOME AFTERNOON SUN...TEMPS WILL REMAIN AT OR
BELOW NORMAL WITH HIGHS AROUND 20. THE COLDEST AIR WILL REMAINED
ENTRENCHED OVER THE EAST NEAR KERY WHERE MAX READINGS REMAIN BLO 15.
TONIGHT...SW WINDS WILL INCREASE AS THE GRADIENT TIGHTENS BETWEEN
THE DEPARTING HIGH AND A TROUGH INTO THE NRN PLAINS. BOUNDARY LAYER
WINDS IN THE 10-20 KNOT RANGE WILL KEEP TEMPS FROM DROPPING OFF TOO
FAR WITH MINS FROM 10 TO 15 INLAND TO AROUND 20 NEAR LAKE SUPERIOR
WHERE DOWNSLOPE FLOW PREVAILS. THE SW WINDS OFF OF LAKE MI WITH 900
MB TEMPS AROUND -10C WILL SUPPORT A BAND OF CLOUDS AND SOME FLURRIES
BUT SHOULD REMAIN TO THE SE OF THE CWA OR JUST CLIP FAR SE LUCE
COUNTY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM EST MON JAN 4 2016
NO SIGNIFICANT WEATHER FOR TUE...BUT A SHORTWAVE WILL MOVE ACROSS
HUDSON BAY TUE INTO TUE NIGHT...DROPPING A SFC TROUGH/FRONT INTO THE
CWA WHERE IT WILL STALL INTO LATE WEEK UNTIL ANOTHER SYSTEM MOVES
THROUGH. COLDER AIR AND WSW WINDS MAY LEAD TO SOME LIGHT LES OVER
MAINLY THE KEWEENAW TUE NIGHT INTO WED MORNING. A WEAK SHORTWAVE
LOOKS TO MOVE ALONG THE FRONT WED NIGHT INTO THU MORNING...WHICH
WILL RESULT IN ADDITIONAL FORCING FOR WIDESPREAD LIGHT TO LOCALLY
MODERATE SNOW. AT THIS TIME...IT LOOKS LIKE THE MODERATE SNOW WILL
FALL OVER LAKE SUPERIOR OR TO THE NW OF THE CWA...BUT RUN TO RUN
CONTINUITY IS NOT GREAT WITH THE SYSTEM WHICH IS EXPECTED AT THAT
TIME FRAME WITH THIS TIME OF SETUP. THINK MOST OR ALL AREAS OF UPPER
MI WILL SEE SUB-ADVISORY AMOUNTS...BUT IF THE BETTER BAND OF SNOW
MOVES OVER WE WOULD PROBABLY SEE ADVISORY AMOUNTS. MAIN TIME FRAME
FOR THE WIDESPREAD SNOW IS WED EVENING INTO THU MORNING.
COULD SEE SOME DRIZZLE/FREEZING DRIZZLE WITH UPSLOPE OVER THE
KEWEENAW AFTER THE SYSTEM SNOW MOVES OUT THU AND AHEAD OF THE NEXT
SYSTEM...BUT THAT IS LOW CHANCE AND LOW CONFIDENCE SO WILL CONTINUE
TO JUST KEEP IT SNOW SHOWERS.
LOTS OF UNCERTAINTY WITH A LATE WEEK INTO THE WEEKEND SYSTEM AS
MODELS HAVE DISAGREEMENT AND RUN TO RUN DISCONTINUITY. MODELS SHOW A
SERIES OF SHORTWAVES LEADING TO A BROAD UPPER TROUGH AND SFC LOW.
SHOULD SEE LIGHT SNOW MOVE IN THU NIGHT/FRI MORNING...POSSIBLY
MIXING WITH OR TURNING TO RAIN OVER MAINLY SOUTHEASTERN UPPER MI FRI
EVENING INTO FRI NIGHT...BUT MODELS HAVE TRENDED COLDER IN THE
LATEST RUNS. PRECIP THEN TURNS BACK TO ALL LIGHT SNOW AND PERSISTS
THROUGH SAT. NOT LOOKING AT ANY SIGNIFICANT SNOWFALL RATES...BUT
IT DOES LOOK LIKE PERSISTENT LIGHT SNOWFALL FOR AROUND 36 HOURS.
SAT NIGHT AND SUN ARE QUITE UNCERTAIN IN EXACT DETAILS...BUT ANOTHER
SHORTWAVE DIVING INTO THE REGION LOOKS TO BRING MUCH COLDER AIR
(POSSIBLY THE COLDEST OF THE SEASON)...SO AT LEAST NW WIND LAKE
EFFECT APPEARS PROBABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1220 PM EST MON JAN 4 2016
WITH HIGH PRES RIDGE PASSING THIS AFTN...RESULTING IN WINDS VEERING
AROUND TO THE SW...STRATOCU OFF LAKE SUPERIOR/MVFR CIGS WILL SHIFT
OFFSHORE. THIS HAS ALREADY OCCURRED AT KIWD/KCMX...AND EXPECT VFR
CONDITIONS TO PREVAIL AT BOTH TERMINALS THRU THIS FCST PERIOD. AT
KSAW...VFR CONDITIONS WILL DEVELOP BY SUNSET IF NOT SOONER.
INCREASING SW WINDS ABOVE STABLE NEAR SFC LAYER WILL RESULT IN LLWS
TONIGHT AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EST MON JAN 4 2016
HIGH PRESSURE WILL QUICKLY BUILD ACROSS THE LAKE THIS MORNING AND
THEN QUICKLY MOVE SOUTH OF THE AREA THIS AFTERNOON. BEHIND THE
HIGH...SOUTHWEST WINDS WILL INCREASE TO GALES FORCE TONIGHT INTO TUE
EVENING AHEAD OF THE NEXT FROTNAL SYSTEM. THE GALE WATCH WAS UPGRADED
TO A WARNING FOR THIS PERIOD. THE FRONT STALLS OUT NEAR LAKE SUPERIOR
FOR WED-FRI...LEADING TO WINDS GENERALLY LESS THAN 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TUESDAY TO 1 AM EST WEDNESDAY FOR
LSZ265>267.
GALE WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 10 PM EST
/9 PM CST/ TUESDAY FOR LSZ162.
GALE WARNING FROM 10 PM THIS EVENING TO 1 AM EST WEDNESDAY FOR
LSZ263-264.
GALE WARNING FROM 6 AM TUESDAY TO 1 AM EST WEDNESDAY FOR LSZ243-
244.
LAKE MICHIGAN...
GALE WATCH FROM TUESDAY MORNING THROUGH LATE TUESDAY NIGHT FOR
LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
340 PM CST MON JAN 4 2016
.DISCUSSION...
Issued at 340 PM CST MON JAN 4 2016
Near term concerns center around the stratus deck lying under the
western half of a departing surface high. The visible and 11u-3.9u
satellite imagery revealed how thin this cloud deck was over the CWA
and as a result we saw much scattering of the deck during the
afternoon hours. Do think the stratus will reform over northwest MO
this evening. However, also expect the clearing seen over central MO
will work its way northwest overnight. The latest RAP now is in line
with the clearing shown by NAM 950mb condensation pressure deficit
progs. Overnight shift will need to monitor for potential fog
development along the periphery of the stratus.
All operational progs continue to show a rather wet period starting
as early as Wednesday morning as the first in a serious of features
work their way through the Central Plains and Mid MO River Valley.
GFS, ECMWF and SREF are in synch timing-wise with the first
shortwave, currently lifting northeast out of AZ. Warm advection
zone preceding this feature will overspread the CWA Wednesday. Have
raised PoPs. Inspection of NAM/GFS Bufr soundings continue to
support a chance of mixed precipitation. Currently the models show a
minimal warm nose aloft so either light freezing rain or snow (no
warm nose) are possible. QPF will be quite light with either one,
but enough that travel problems are possible for the morning rush
commute to work.
While a second shortwave will arrive on Thursday the increasingly
moist isentropic ascent could yield areas of drizzle/patchy rain
overnight Wednesday so high chance PoPs used. Steady moderate warm
air advection through a deep layer will allow temperatures to remain
above freezing through Friday. So, precipitation will be all liquid.
Friday night could bring a mix of rain and snow to the region as the
deformation zone lifts through the region. Quite a bit of difference
between the strength of the upper system/associated surface low with
the GFS considerably stronger. Given how much energy remains back to
the southwest within an elongated longer upper trough have little
confidence in a strong or well developed surface low. So, have not
bit on the GFS snow output.
Much colder air filters into the region over the weekend with
temperatures struggling to recover on Saturday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1154 AM CST MON JAN 4 2016
Eastern edge of low-end MVFR stratus deck over northwest/west
central MO will continue to erode westward through the afternoon
hours. This erosion will slow after sunset with northwest MO likely
remaining under a MVFR canopy into early Tuesday morning. Satellite
imagery does show that where clouds scattered out a higher based MVFR
ceiling has formed over northeast and central MO. This cloud deck
should thin/scatter out after sunset. Otherwise, surface winds will
continue to gradually veer from the east to south during the period.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...MJ
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1201 PM CST MON JAN 4 2016
.DISCUSSION...
Issued at 331 AM CST MON JAN 4 2016
Stratus will continue to impact the region today and possibly into
tonight as moisture continues to pool and advect across the northern
and eastern Plains. NAM and RAP indicate stratus holding strong
through the day and possibly even retrograding slightly to the west,
and thus have lowered temperatures another degree or two for today,
and raised low temperatures a few degrees for tonight.
The main concern in the forecast remains the potential for some wet
weather during the latter half of the work week, possibly starting
out as light freezing drizzle early Wednesday morning just ahead of
the surface warm front. Synoptically, the broad western trough is
still expected to push developing surface low pressure eastward
across the forecast area on Friday, and isentropic lift/moisture
advection will support periods of light rain Wednesday through
Friday as the system ejects out. Temperatures will warm above the
freezing mark mid-morning Wednesday and remain there through
Saturday, keeping precipitation type all rain once the surface warm
front passes through the CWA. Precipitation will be very light until
saturation deepens and forcing improves Thursday evening, then a
half inch or perhaps a little more rainfall is possible through late
Friday just ahead of and in the vicinity of the surface low. A brief
mix with or changeover to snow is also still possible on the back
side of the system Saturday, but moisture should be limited enough
and the speed of the system fast enough to prevent much, if any,
snow accumulation.
Much colder temperatures are expected behind this system and
especially early next week when all model solutions show a deepening
trough digging into the Great Lakes region and allowing -25 to -30 C
850 mb temperatures to surge southward into the Midwest. Started the
trend of lowering both highs and lows from Saturday night through
the end of the forecast period, and will likely have to continue to
do so until model blends start to pick up on the anomalous pattern
early next week. Highs will likely top out in the teens or even the
upper single digits by the beginning of the next work week, and lows
could possibly fall below zero near the IA/MO border if the cold air
arrives as progged. Enough dry air accompanies this system to
prevent any decent potential for precipitation, so have kept the
forecast dry beyond this weekend`s system and do not anticipate
any wintry precipitation as the cold air arrives.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1154 AM CST MON JAN 4 2016
Eastern edge of low-end MVFR stratus deck over northwest/west
central MO will continue to erode westward through the afternoon
hours. This erosion will slow after sunset with northwest MO likely
remaining under a MVFR canopy into early Tuesday morning. Satellite
imagery does show that where clouds scattered out a higher based MVFR
ceiling has formed over northeast and central MO. This cloud deck
should thin/scatter out after sunset. Otherwise, surface winds will
continue to gradually veer from the east to south during the period.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1127 AM CST MON JAN 4 2016
.SHORT TERM: (Today and Tonight)
Issued at 330 AM CST Mon Jan 4 2016
The large high pressure system currently centered near the NE/IA
border will be the dominant weather feature today. Biggest
challenge will be stratus trapped within southeastern quadrant of
the high. The models are in good agreement that the center of the
high will slide to the north today which will lead to veering of
the low level winds from north to northeast. This pattern should
allow erosion/clearing from the northeast, beginning over west-
central and south central IL, with the stratus field pivoting to
a slightly more N/S orientation. Based on this scenario and RH
progs from the RAP and NAM, locations west of the MS River should
clear last. I currently have this occuring late afternoon and that
may be a tad fast. Continued veering of the low level winds to a
more southerly component will occur tonight as the high retreats,
which should promote remaining clouds to be advected to the
northwest. Another seasonably cold day and night is expected.
Glass
.LONG TERM: (Tuesday through Sunday)
Issued at 330 AM CST Mon Jan 4 2016
A progressive flow regime will continue to mature with a ridge
aloft overhead early Tuesday, dampening and moving east on
Tuesday night. The accompanying retreat of the low level
anticyclone will bring veering southeast-southwest lower trop flow
and pronounced WAA, and hence warmer temperatures. More active
southwest flow aloft ensues Wednesday through late Friday as a
broad longwave trof shifts eastward in response to several well-
defined migratory short waves. Weak large scale ascent and low
level WAA associated wth the first of these waves will result in
slight chance pops Wednesday afternoon for parts of central MO,
increasing to chance pops Wednesday night. I haven`t mentioned it
in the forecast due to the low probability, but there could be a
brief period of sleet or a rain/sleet mix at the onset of
precipitation due to evaporative cooling, however WAA will
utlimately win out.
Rain chances will ramp up Thursday/Thursday Night due to stronger
forcing/lift associated with the next more potent migratory short
wave trof.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1125 AM CST Mon Jan 4 2016
Stratus was trying to clear this morning from the northeast but
the sun has caused some diurnal stratocu to develop on the edge
and that is expected to continiue through the daylight hours for
much of the area. Cloud base has lifted to VFR in most locations.
North wind becomes light tonight and southeast tomorrow.
Specifics for KSTL:
Broken VFR stratocu today with clearing tonight. North wind to
become light.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
404 PM CST MON JAN 4 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 404 PM CST MON JAN 4 2016
THE PRIMARY FORECAST CHALLENGES WILL CENTER AROUND LOW STRATUS AND
FOG DEVELOPMENT...ALONG WITH POTENTIAL IMPACT OF CLOUDS/FOG ON
TEMPERATURES.
THIS AFTERNOON THROUGH TONIGHT...LOW STRATUS HAS BEEN SLOW TO ERODE
AND REMAINS ACROSS PORTIONS OF OUR EASTERN FORECAST AREA THIS
AFTERNOON. THESE LOW STRATUS CLOUDS ARE EXPECTED TO EXPAND BACK
ACROSS THE AREA OVERNIGHT AS MOIST SOUTHERLY WINDS KICK UP ACROSS
THE REGION. RECENT RUNS OF THE HRRR HAVE BEEN VERY AGGRESSIVE WITH
GRADUALLY DEVELOPING FOG ACROSS MUCH OF THE FORECAST AREA AS WE HEAD
THROUGH THE OVERNIGHT HOURS. THEREFORE...WILL FORECAST AREAS OF FOG
TONIGHT AND MAY EVEN END UP NEEDING A DENSE FOG HEADLINE SHOULD THE
FOG FORM AND BECOME DENSE ENOUGH. NOT ENOUGH CONFIDENCE THIS FAR OUT
TO ISSUE A HEADLINE AS OF THIS AFTERNOON...BUT WOULD NOT BE
SURPRISED IF A DENSE FOG HEADLINE IS EVENTUALLY NEEDED LATER TONIGHT.
TUESDAY...MOST FORECAST MODELS KEEP A MAJORITY OF OUR FORECAST AREA
STUCK UNDER A LOW STRATUS DECK THROUGHOUT THE DAY. SOUTHWESTERN
ZONES SEEM TO STAND THE BEST CHANCE AT CATCHING SOME LATE DAY
SUNSHINE...BUT NO GRANTEES AS THIS FOG/LOW CLOUD FORECAST IS VERY
CHALLENGING. FOG WILL BE AT ITS WORST DURING THE CLIMATOLOGICALLY
FAVORABLE TIME...TUESDAY MORNING...AND THEN SHOULD BEGIN TO LIFT
INTO MORE OF A LOW STRATUS BY LATER IN THE MORNING/AFTERNOON. THE
SOUTHERLY WINDS WILL ADVECT WARMER AIR INTO THE REGION...BUT WITH
THICK LOW CLOUDS TEMPERATURES MAY HAVE A DIFFICULT TIME RISING
MUCH...ESPECIALLY OVER SNOW COVERED AREAS. CONFIDENCE IN THE
TEMPERATURE FORECAST IS LOWER THAN NORMAL WITH A WIDE SPREAD IN
MODEL TEMPERATURES DEPENDING ON IF ANY SUN CAN POKE THROUGH THE
CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 404 PM CST MON JAN 4 2016
THIS 6-DAY PERIOD CAN BASICALLY BE BROKEN DOWN INTO 3 TIME
FRAMES WITH THEIR OWN UNIQUE HIGHLIGHTS/CHALLENGES...AND WILL
START OUT BY BREAKING THESE DOWN:
1) TUESDAY NIGHT-WEDNESDAY NIGHT: ALTHOUGH NO ACCUMULATING SNOW IS
CURRENTLY EXPECTED DURING THESE 36 HOURS DUE TO LACK OF SATURATION
ALOFT...THERE ARE LEGITIMATE CONCERNS FOR AT LEAST SOME SPOTTY
LIGHT FREEZING DRIZZLE/FREEZING RAIN MAINLY DURING THE NIGHT AND
EARLY MORNING HOURS. THERE COULD ALSO BE MORE FOG ISSUES AS
WELL...BUT GIVEN HOW UNCERTAIN/TRICKY FOG TRENDS CAN BE IN THIS
PATTERN...AND THAT WE ALREADY HAVE FOG MENTIONED IN THE SHORT TERM
PERIOD DESCRIBED ABOVE...WILL DEFER TO LATER SHIFTS TO INTRODUCE
ANY POSSIBLE NEED FOR FOG INTO THE OFFICIAL FORECAST FOR TUESDAY
NIGHT AND BEYOND.
2) THURSDAY DAYTIME-FRIDAY NIGHT: AS HAS BEEN THE CASE FOR THE
PAST SEVERAL DAYS...THIS 48-HOUR PERIOD STILL FEATURES THE
POTENTIAL "MAIN EVENT" OF THE WEEK IN TERMS OF POTENTIAL SNOW
ACCUMULATION. ALTHOUGH WE ARE CREEPING EVER-CLOSER...BECAUSE WE
ONLY ADVERTISE OFFICIAL SNOW ACCUMULATION FORECASTS THROUGH 72
HOURS...OUR CURRENT FORECAST DOES NOT INCLUDE ANY ACCUMULATION
DATA FOR THURSDAY NIGHT-FRIDAY...WHICH IS WHEN MOST SNOW IS
EXPECTED TO FALL. THAT BEING SAID...WITH THIS POSSIBLE SNOW EVENT
WITHIN 4 DAYS NOW...AND WITH MODELS SUCH AS THE 12Z ECMWF/GFS
SUGGESTING THAT AT LEAST A FEW INCHES COULD AFFECT PARTS OF THE
CWA...HAVE OPTED TO INTRODUCE A MENTION IN OUR LATEST HAZARDOUS
WEATHER OUTLOOK (HWOGID). OF COURSE...THERE IS STILL PLENTY OF
UNCERTAINTY ESPECIALLY REGARDING THE LOW-LEVEL TEMPERATURE PROFILE
AND JUST HOW QUICKLY/SLOWLY ESPECIALLY OUR SOUTHERN/SOUTHEAST
COUNTIES WILL CHANGE OVER FROM RAIN TO SNOW...AS RAIN COULD BE THE
PREDOMINANT PRECIPITATION TYPE MUCH OF THE TIME IN THIS AREA.
CONVERSELY...ALTHOUGH SNOW APPEARS TO BE THE MORE DOMINANT TYPE IN
ESPECIALLY NORTHERN/WEST-CENTRAL COUNTIES...THERE ARE QUESTIONS
HERE ABOUT HOW MUCH PRECIPITATION MIGHT ACTUALLY FALL COMPARED TO
COUNTIES FARTHER SOUTH AND EAST. THUS...IN THEORY...THIS COULD BE
A SITUATION WHERE CENTRAL PORTIONS OF THE CWA ACTUALLY SEE THE
HIGHEST SNOWFALL AMOUNTS IF TRENDS CONTINUE ON THEIR CURRENT
TRACK...WITH LESSER AMOUNTS NORTHWEST AND SOUTHEAST. STILL TOO
SOON TO SAY FOR SURE THOUGH...AND PLEASE NOTE THAT WE ARE 24-36
HOURS AWAY FROM ADVERTISING SNOW ACCUMULATION TOTALS THAT WILL
CAPTURE THE ENTIRE EVENT.
3) SATURDAY DAYTIME-MONDAY DAYTIME: THESE LAST 3 DAYS OF THE
FORECAST HAVE BEEN KEPT AS/INTRODUCED AS OFFICIALLY DRY...AS
ALTHOUGH IT`S NOT OUT OF THE QUESTION THAT SOME VERY LIGHT
SNOW/FLURRIES COULD MAYBE LINGER INTO AT LEAST SATURDAY MORNING
IN LATER FORECASTS (ESPECIALLY PER THE ECMWF SOLUTION)...THERE
APPEARS TO BE VERY LITTLE IF ANY CHANCE OF ANOTHER LEGITIMATE
WINTRY PRECIPITATION EVENT THROUGH THIS TIME. THAT MEANS THAT THE
MAIN STORY WILL TURN TOWARD COLDER-THAN-NORMAL TEMPERATURES.
ALTHOUGH MODELS ARE CERTAINLY NOT IN LOCK-STEP AT THIS DAY 5-7
RANGE (AS IS TYPICAL)...AT LEAST FOR NOW WE ARE AIMING HIGH
TEMPERATURES ONLY INTO THE 18-28 DEGREES RANGE ACROSS MOST OF THE
CWA...WHICH IS ROUGHLY 7-15 DEGREES BELOW AVERAGE/NORMAL FOR EARLY
JANUARY. IN TURN...OVERNIGHT LOW TEMPERATURES FROM SATURDAY NIGHT
ONWARD ARE EXPECTED TO DROP INTO THE SINGLE DIGITS ABOVE ZERO
ACROSS MUCH OF THE CWA.
WITH THE PRIMARY 3 WEATHER "REGIMES" AND THEIR CONCERNS BROKEN
DOWN ABOVE...WILL FINISH WITH A FAIRLY BRIEF LOOK AT A BIT MORE
METEOROLOGICAL DETAIL IN 12-60 HOUR BLOCKS:
TUESDAY EVENING/NIGHT: ALTHOUGH PREVIOUS FORECAST ALREADY
INTRODUCED THE POSSIBILITY OF SOME LIGHT FREEZING DRIZZLE IN FAR
SOUTHEAST COUNTIES...THIS LATEST PACKAGE HAS EXPANDED THIS "SLIGHT
CHANCE" MENTION OF FREEZING DRIZZLE AND/OR DRIZZLE TO ENCOMPASS
THE MAJORITY OF THE CWA...ASSUMING OF COURSE THAT WIDESPREAD LOW
STRATUS CLOUDS DO IN FACT DOMINATE THE AREA IN INCREASINGLY-MOIST
LOW LEVEL SOUTHERLY FLOW. VARIOUS 12Z/18Z MODELS ARE IN GOOD
AGREEMENT IN TRACKING THE FIRST LEGITIMATE-BUT-LOW-AMPLITUDE MID
LEVEL SHORTWAVE TROUGH OF THE WEEK NORTHEASTWARD ACROSS THE HEART
OF NEB/KS...THUS PROVIDING AT LEAST LOW-LEVEL LIFT FOR SOME
DRIZZLY ACTIVITY. THERE ARE HINTS THAT MAINLY THE FAR SOUTHEAST
CWA COULD SEE A QUICK BURST OF SNOW/POSSIBLY SLEET...BUT THIS
SEEMS MORE FAVORED OUTSIDE THE CWA WITHIN EASTERN KS. ASSUMING
PLENTIFUL CLOUDS AND SOUTHERLY SURFACE BREEZES GENERALLY 10-15
MPH...THIS SHOULD BE A SEASONABLY "MILD" NIGHT WITH LOWS ONLY
DROPPING TO AROUND 30 MOST PLACES.
WEDNESDAY/WEDNESDAY NIGHT: WHILE THE LOCAL AREA LARGELY SITS "IN
BETWEEN" UPPER LEVEL WAVES/FORCING DURING THIS TIME...THE PESKY
LOW-LEVEL STRATUS/SATURATION LOOKS TO PERSIST...AND THUS HAVE KEPT
A MENTION OF LIGHT RAIN/FREEZING RAIN OR LIGHT DRIZZLE/FREEZING
DRIZZLE GOING MUCH OF THIS TIME...DEPENDING ON SURFACE TEMPS.
SPEAKING OF WHICH...CONFIDENCE IS BELOW AVERAGE REGARDING WED HIGH
TEMPS DEPENDING ON THE BATTLE OF SOUTHERLY WARM AIR ADVECTION
VERSUS CLOUD COVER...BUT IF ANYTHING NUDGED HIGHS DOWN 1-2 DEGREES
FROM PREVIOUS WITH MID-UPPER 30S IN MOST NEB ZONES.
THURSDAY-THURSDAY NIGHT: SEE NUMBER "2" ABOVE FOR VARIOUS COMMENTS
ON THIS POSSIBLE SNOW EVENT...BUT IT WOULD GET UNDERWAY DURING
THIS TIME FRAME AS THE NEXT BATCH OF MID-UPPER FORCING ARRIVES
FROM THE SOUTHWEST...ALTHOUGH NOT IN AN OVERLY-ORGANIZED FASHION.
LATER FORECASTS MAY HAVE TO CONSIDER EXTENDING DRIZZLE/FREEZING
DRIZZLE POTENTIAL INTO AT LEAST THURSDAY DAYTIME BEFORE STEADIER
SNOW AND/OR RAIN BECOMES THE MORE DOMINANT TYPE. HAVE LOW END
"LIKELY" 60 PERCENT PRECIP CHANCES ACROSS MOST OF THE CWA FOR
THURSDAY NIGHT.
FRIDAY-FRIDAY NIGHT: ALTHOUGH ITS POSSIBLE THAT A LITTLE RAIN
POTENTIAL COULD STILL BE PRESENT BY SUNRISE FRIDAY IN FAR
SOUTHEAST ZONES...DEEPENING COLD AIR BEHIND A PASSING SURFACE COLD
FRONT SHOULD TRANSITION PRECIP TYPE TO SNOW ACROSS THE ENTIRE AREA
IF IT HASN`T ALREADY. WHILE SOME MODELS SUCH AS THE GFS PRETTY
MUCH SHUT DOWN ACCUMULATING SNOW BY FRIDAY NIGHT...OTHERS SUCH AS
THE ECMWF KEEP IT GOING.
SATURDAY DAYTIME-MONDAY DAYTIME: NOTHING MORE TO SAY HERE OTHER
THAN WHAT WAS ALREADY COVERED IN NUMBER "3" EARLIER ON: CONFIDENCE
IS REASONABLY HIGH IN A MAINLY SNOW-FREE STRETCH OF WEATHER WITH
THE ONLY REAL QUESTION SURROUNDING HOW COLD IT ACTUALLY GETS.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1233 PM CST MON JAN 4 2016
THIS IS A VERY CHALLENGING AVIATION FORECAST PERIOD DUE TO THE
POSSIBILITY OF FOG AND/OR VERY LOW STRATUS. A LOW STRATUS DECK HAS
BEEN LOCATED JUST EAST OF KGRI THROUGH THE LATE MORNING HOURS AND
SHOULD SLOWLY ERODE EVEN FURTHER BACK TO THE EAST THROUGH THE
AFTERNOON HOURS. HOWEVER...SEVERAL FORECAST MODELS REDEVELOP THE
LOW STRATUS AND FOG LATER TONIGHT. THEREFORE...WILL ACCOUNT FOR
THIS POSSIBLE IFR CEILING AND VISIBILITY SITUATION IN THE TAF FOR
LATER TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...WESELY
LONG TERM...PFANNKUCH
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1244 PM CST MON JAN 4 2016
.UPDATE...
ISSUED AT 608 AM CST MON JAN 4 2016
DID A QUICK UPDATE TO HIT THE FOG A LITTLE HARDER IN A CURVED
NARROW CORRIDOR ON THE WEST EDGE OF THE SLOWLY EAST-PROGRESSING
STRATUS INTRUSION THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CST MON JAN 4 2016
SATELLITE AND OBSERVATIONS SHOW STRATUS AND FOG ACROSS EASTERN
NEBRASKA AND KANSAS THAT IS MOVING TO THE WEST TONIGHT. AHEAD OF THE
STRATUS VISIBILITIES HAVE BEEN DROPPING AND A FEW LOCATIONS HAVE
DROPPED BELOW A HALF MILE. LOOKING AT WEBCAMS AROUND THE AREA THE
VISIBILITY APPEARS TO VARY GREATLY FROM LOCATION TO LOCATION.
AS THE STRATUS MOVES TO THE WEST EXPECT THE FOG ON THE EDGE OF THE
STRATUS TO ALSO MOVE TO THE WEST. THE HRRR HAS SOME FOG SPREADING
INTO THE FORECAST AREA...BUT THE FOG IS SPREADING A LITTLE FASTER
THAN THE LATEST RUN. BASED ON THE LOCATION OF THE LOWER VISIBILITY
FROM THE HRRR THE WORST OF THE FOG SHOULD BE IN THE EASTERN HALF TO
TWO THIRDS...MAINLY ALONG AND EAST OF HIGHWAY 183. HAVE KEPT SOME
FOG IN THE WEST...BUT HAVE THE WORSE CONDITIONS FURTHER TO THE EAST.
SO THE NEXT QUESTION BECOMES WHEN WILL THE VISIBILITY IMPROVE? THE
HRRR KEEPS VISIBILITY LOWER THROUGH THE MORNING HOURS AND EAST OF
HIGHWAY 281 AND NORTH OF HIGHWAY 6 COULD LINGER THROUGH MUCH OF THE
DAYTIME HOURS. HAVE KEPT SOME FOG THROUGH THE MORNING HOURS THEN
MOSTLY CLOUDY SKIES THROUGH THE AFTERNOON.
THE SURFACE HIGH CENTERED OVER WESTERN IOWA EARLY THIS MORNING IS
EXPECTED TO MOVE TO THE EAST. THE PRESSURE GRADIENT WILL TIGHTEN FOR
TODAY AND TONIGHT. THROUGH THE DAYTIME THE WINDS ALOFT ARE ONLY 10
TO 20 KTS SO NOT EXPECTING WINDS TO INCREASE MUCH...BUT THEY SHOULD
TURN TO THE SOUTH INSTEAD OF FROM THE EAST AS THEY ARE EARLY THIS
MORNING. THIS SHOULD HELP THE FOG BECOME LESS OF A CONCERN FOR LATER
THIS MORNING AND INTO THE AFTERNOON.
THE PRESSURE GRADIENT CONTINUES TO BE FAIRLY TIGHT TONIGHT AND WINDS
ALOFT INCREASE TO AROUND 45KTS. WINDS WILL NOT BE STRONG
TONIGHT...BUT THEY WILL INCREASE TO THE 10 TO 20 MPH RANGE AND FOG
SHOULD NOT FORM TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 516 AM CST MON JAN 4 2016
THIS CONTINUES TO BE A CHALLENGING LONG TERM...ESPECIALLY REGARDING
A POTENTIAL FOR SNOW TOWARD MID-LATE WEEK.
KICKING OFF WITH TUESDAY...I ACTUALLY RAISED TEMPERATURE A BIT FOR
TUESDAY HIGHS WITH THE EXPECTED WARM AIR ADVECTION AND REDUCED SNOW
COVER...ALTHOUGH I EXPECT PLENTY OF CLOUDS...SO NOT GOING TO CRAZY
HERE WITH HIGHS GENERALLY NEAR 40 TO THE MID 40S. FOG MAY BE A
CONCERN FOR AT LEAST A COUPLE OF MORNINGS...AS MELTING SNOW MAY PLAY
A PART IN THIS. I DID NOT ADD ANY...BUT THE POTENTIAL IS THERE.
A SHORTWAVE TROUGH OR PERHAPS A SERIES OF TROUGHS ARE FORECAST TO
KICK OUT OF THE SOUTHERN ROCKIES INTO OUR AREA BY THE WEDNESDAY
THROUGH FRIDAY TIME FRAME. MODELS DEFINITELY VARY WITH PLACEMENT AND
TIMING...SO ANY POTENTIAL SNOWFALL AMOUNTS ARE TOUGH. IT APPEARS
THAT THE BEST SHOT AT PRECIPITATION WILL BE THE THURSDAY/THURSDAY
NIGHT TIME FRAME. ONE THING APPEARS CERTAIN...WE SHOULD SEE A STEADY
DECLINE OF HIGH TEMPERATURES FOR THE REST OF THE LONG TERM AS A MEAN
TROUGH DEVELOPS FOR THE WESTERN HALF OF THE COUNTRY AND INTRODUCES
QUITE POSSIBLY THE COLDEST AIR OF THE YEAR SO FAR. BY SUNDAY...IT
WILL PROBABLY BE A STRUGGLE TO MAKE IT INTO THE 20S...AND JUST
OUTSIDE THE SCOPE OF THE LONG TERM ON MONDAY NEXT WEEK...I WOULD NOT
BE SURPRISED IF WE DID NOT MANAGE TO BREAK OUT OF THE TEENS FOR
HIGHS. WE WILL BE FAR ENOUGH INTO THE COLD AIR THAT CONSRAW SEEMS TO
BE PICKING UP ON THE COLD AIR BETTER THAN ANYTHING ELSE...AT LEAST
FOR HIGH TEMPERATURES.
FORECAST SOUNDINGS INDICATE A POTENTIAL FOR SOME FREEZING DRIZZLE IN
OUR SOUTHEAST AS WE START GETTING SOME SIGNALS FOR THE
DRIZZLE/FREEZING DRIZZLE. BY THE TIME LIGHT PRECIPITATION MAY
SPREADS FARTHER NORTH...I SUSPECT SURFACE TEMPERATURES TO WARM ABOVE
FREEZING AND WE COULD EVEN FURTHER SATURATE MID AND UPPER
LEVELS...SO I KEPT ANY FREEZING DRIZZLE MENTIONED TO LATE TUESDAY
NIGHT AND EARLY WEDNESDAY FOR FAR SOUTHEASTERN PARTS OF THE CWA.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1233 PM CST MON JAN 4 2016
THIS IS A VERY CHALLENGING AVIATION FORECAST PERIOD DUE TO THE
POSSIBILITY OF FOG AND/OR VERY LOW STRATUS. A LOW STRATUS DECK HAS
BEEN LOCATED JUST EAST OF KGRI THROUGH THE LATE MORNING HOURS AND
SHOULD SLOWLY ERODE EVEN FURTHER BACK TO THE EAST THROUGH THE
AFTERNOON HOURS. HOWEVER...SEVERAL FORECAST MODELS REDEVELOP THE
LOW STRATUS AND FOG LATER TONIGHT. THEREFORE...WILL ACCOUNT FOR
THIS POSSIBLE IFR CEILING AND VISIBILITY SITUATION IN THE TAF FOR
LATER TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1138 AM CST MON JAN 4 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CST MON JAN 4 2016
TODAY AND TONIGHT...THE ARCTIC DRAPE ACROSS ERN NEB SHOULD BE PULLED
WEST INTO THE FCST AREA THIS MORNING AND THEN NORTH DURING THE AFTN.
THE RAP MODEL BOUNDARY LAYER RH PROVIDES A PESSIMISTIC FCST OF
STRATUS APPROACHING HIGHWAY 83 AND SOCKING AREAS EAST ALL DAY. THE
NAM IS MORE MODERATE SUGGESTING MIXING AND SUNSHINE TODAY TO BE
REPLACED BY HIGH CLOUDS IN THE AFTN. THIS APPEARS TO BE SUPPORTED BY
THE GFS AND ECM.
AREAS OF FOG ARE UNDERWAY AS INDICATED IN THE RAP WHICH WOULD MIX
OUT THIS AFTN AS SHOWN BY THE NAM. THE TEMPERATURE FORECAST USES THE
ECS AND MAV GUIDANCE PLUS BIAS CORRECTION FOR HIGHS IN THE 30S TO
AROUND 40. SOUTH WINDS INCREASE TO 10 TO 20 MPH. H850MB TEMPERATURES
RISE TO 2 TO 6C THIS AFTN WHICH COULD PRODUCE HIGHS IN THE 40S
ACROSS ALL AREAS. THE TEMPERATURE FORECAST REPRESENTS A DIFFERENTIAL
BETWEEN THE SOUTH WINDS AND HIGH CLOUDS WHICH LIMIT MIXING VS WARM
AIR ADVECTION.
TONIGHT THE GFS AND NAM INDICATE STRATUS DEVELOPMENT IN A GRADIENT
OF STRONG SOUTHWEST WINDS. THE ECM BUILDS A MESO HIGH ACROSS THE
SANDHILLS ELIMINATING MOISTURE POOLING FOR CLOUD FORMATION. THE
FORECAST FOLLOWS THE GFS AND NAM WITH LOWS IN THE TEENS AND LOWER
20S. SOUTH WINDS CONTINUE AT 10 TO 20 MPH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 342 AM CST MON JAN 4 2016
12Z TUESDAY AND BEYOND. THE MODELS CONTINUE TO ADVERTISE THE
PASSAGE OF A LEAD SHORTWAVE FROM THE SOUTHWEST LATE TUESDAY INTO
WEDNESDAY. THE MODELS SUGGEST INCREASING SYSTEM RELATIVE UPGLIDE
GENERALLY ALONG THE 285-290K SURFACES THAT MAY WORK IN CONJUNCTION
WITH SMALL CONDENSATION PRESSURE DEFICITS TO PRODUCE LIGHT QPF
ACROSS OUR EASTERN ZONES EARLY WEDNESDAY. THE GFS IS LEADING THE
CHARGE WITH SUFFICIENT SATURATION TO PRODUCE A FEW HUNDRETHS
QPF...WHEREAS THE NAM AND THE ECMWF CONFINE MOISTURE IN THE LOWEST
LAYERS OF THE TROPOSPHERE AND GENERALLY FAVOR STRATUS...OR POSSIBLY
LIGHT DZ. WILL MAINTAIN A DRY FORECAST FOR NOW...BUT CONTINUE TO
CLOSELY MONITOR AS THE TIMING OF THE EVENT WOULD FAVOR FROZEN
QPF...EITHER -FZDZ OR -SN. THE SYSTEM AND ANY POTENTIAL QPF IS
SHOWN TO BE EAST OF THE FORECAST AREA BY 00Z THURSDAY. THE WAVE IF
NOTHING ELSE WILL PULL A WEAK BOUNDARY SOUTH ACROSS THE SANDHILLS ON
WEDNESDAY...COOLING TEMPERATURES SLIGHTLY.
ATTENTION TURNS TO THE NEXT PIECE OF ENERGY EJECTING FROM A WESTERN
CONUS MID-LEVEL TROUGH. THE GENERAL IDEA OF THE ECMWF AND GFS IS TO
DEVELOP A CLOSED LOW SOUTH OF THE CWA LATE THURSDAY INTO FRIDAY.
HOWEVER...THE MODELS /ESPECIALLY THE GFS/ HAVE TRENDED SOUTH WITH
THIS FEATURE. CONFIDENCE IS WANING...THUS NO CHANGES WERE MADE TO
THE EXTENDED BLEND PROCEDURE...WHICH ESSENTIALLY PRODUCED SIMILAR
RESULTS FROM THE PREVIOUS FORECAST. THE HIGHER END CHANCE POPS ARE
MAXIMIZED ACROSS OUR SOUTHERN AND EASTERN ZONES...WHICH IS
APPROPRIATE. PTYPE IS UNCERTAIN AT THIS POINT AS THE VARIOUS MODELS
SUGGEST DIFFERING AMOUNT OF SATURATION AND THERMAL PROFILES. LIGHT
FZDZ...-RA...-SN OR -ZR CANNOT BE RULED OUT AT THIS POINT. GIVEN THE
RECENT PATTERN...THE MOST LIKELY PTYPE WILL BE -SN WITH POSSIBLY A
PERIOD OF -FZDZ. MORE CERTAIN IS THAT IN THE WAKE OF THE SYSTEM
COLDER AIR WILL BE DRAWN SOUTH ACROSS THE CENTRAL PLAINS FOR LATE
WEEK AND THE WEEKEND. AS THE ARCTIC HIGH SETS UP RESIDENCE ACROSS
WEST CENTRAL NEBRASKA ON SUNDAY...HIGHS MAY STRUGGLE TO CLIMB OUT OF
THE TEENS WITH AREAS OF SUB 0F LOWS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1138 AM CST MON JAN 4 2016
THE MAIN CONCERN THROUGH THIS EVENING WILL BE SOUTHERLY WINDS
GUSTING TO NEAR 25 KTS. TONIGHT...THE WIND SPEED WILL LOWER
SLIGHTLY...BUT THE CHANCE OF STRATUS INCREASES. MVFR TO IFR
CEILINGS ARE POSSIBLE OVERNIGHT INTO TUESDAY MORNING...GENERALLY
FROM KLBF TO KVTN AND POINTS EAST. ON THE WESTERN FRINGE OF THE
STRATUS...MOST LIKELY ACROSS THE NEBRASKA PANHANDLE...FOG WILL BE
POSSIBLE. THE FOG AND STRATUS SHOULD DISSIPATE BY LATE MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...SNIVELY
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
933 AM PST MON JAN 4 2016
.SYNOPSIS...A SERIES OF PACIFIC STORMS WILL AFFECT THE REGION
THROUGH MUCH OF THE WEEK. THE FIRST SYSTEM TODAY IS EXPECTED TO
BRING SCATTERED LIGHT PRECIPITATION TO THE REGION...BUT TWO SYSTEMS
MOVING ACROSS TUESDAY THROUGH THURSDAY ARE EXPECTED TO BE MUCH
WETTER AND BRING WIDESPREAD VALLEY RAIN AND MOUNTAIN SNOW. HEAVY
SNOW IS A GOOD POSSIBILITY IN THE MOUNTAINS.
&&
.UPDATE...ANOTHER UPDATE TO TWEAK THE PRECIPITATION FORECAST THROUGH
THE DAY. LATEST RUNS OF THE HRRR HAVE PUSHED PRECIP A BIT FURTHER
WEST THIS AFTERNOON...AND WE MAY GET ANOTHER ROUND OF SHOWERS IN THE
LAS VEGAS METRO AREA BY SUNSET/EVENING COMMUTE. WILL CONTINUE TO
MONITOR AND UPDATE AS NEEDED.
&&
.PREV UPDATE...755 AM PST MON JAN 4 2016...QUICK UPDATE TO INCREASE
POPS TODAY...MAINLY FROM LAS VEGAS EAST WHERE LIGHT PRECIPITATION
HAS BROKEN OUT THIS MORNING. LATEST SHORT-RANGE HIGH-RES GUIDANCE
HAS CONTINUED SHOWER ACTIVITY MOVING NORTH THROUGH THE DAY. ALSO
INCREASED QPF AMOUNTS OVER THE MOUNTAINS...WITH THE PRIMARY INCREASE
OF NOTE OVER THE SPRING MOUNTAINS...WHERE WEAK LOW-LEVEL UPSLOPE
FLOW COULD RESULT IN ENHANCED PRECIPITATION. UPDATE FORECAST CALLS
FOR 2-4 INCHES OF NEW SNOW ABOVE 8000 FEET...BUT WILL NEED TO
MONITOR THROUGH THE DAY.
&&
.AVIATION...FOR MCCARRAN...LIGHT AND MOSTLY VARIABLE WINDS ARE
EXPECTED AT THE TERMINAL THROUGH TODAY. CONSIDERABLE CLOUD COVER AND
SHOWER ACTIVITY WILL PERSIST THROUGH TODAY WITH CIGS LOWERING
THROUGH THE AFTERNOON. LATEST THINKING IS THAT CIGS ARE LIKELY TO
DROP TO TO 3-5K FEET THIS AFTERNOON. CONDITIONS ARE LIKELY TO
IMPROVE THIS EVENING/OVERNIGHT BEFORE DROPPING AGAIN EARLY TUESDAY
MORNING. CIGS TUESDAY MAY DROP TO BELOW 2-3K FEET...WITH RAIN
SHOWERS. SIGNIFICANT PERIOD OF RAINFALL IS EXPECTED TUESDAY
AFTERNOON THROUGH TUESDAY EVENING.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...THE FIRST OF A SERIES OF SYSTEMS WILL MOVE THROUGH THE
REGION TODAY WITH ISOLATED TO SCATTERED SHOWERS AND CIGS DOWN TO 3-
5K FEET AT TIMES. THE MOST LIKELY AREAS FOR LOW CIGS AND PRECIP WILL
BE ACROSS MOHAVE...LINCOLN...CLARK...AND EASTERN SAN BERNARDINO
COUNTIES. MOST OTHER AREAS WILL SEE CIGS IN THE 5-10K FOOT RANGE.
WINDS WILL REMAIN UNDER 10KTS MOST AREAS. THERE WILL BE A BRIEF
BREAK IN SHOWERS AND LOWER CIGS WORKING FROM WEST TO EAST TONIGHT
AND EARLY TUESDAY. BY LATE TUESDAY MORNING...PRECIPITATION AND
MOUNTAIN OBSCURATIONS WILL BECOME MORE WIDESPREAD AS THE SECOND IN A
SERIES OF WET SYSTEMS MOVE THROUGH THE AREA.
&&
.PREV DISCUSSION...
332 AM PST MON JAN 4 2016
.SHORT TERM...THROUGH TUESDAY NIGHT.
THE FIRST IN A SERIES OF STORMS WILL MOVE THROUGH THE REGION TODAY
AND GRADUALLY WEAKEN AS IT MOVES EAST AND PRODUCE MAINLY LIGHT
SHOWERS OVER MUCH OF THE AREA. MOHAVE AND LINCOLN COUNTIES ARE
FORECAST TO SEE THE GREATEST CHANCE OF SHOWERS TODAY...BUT MOST
OTHER AREAS WILL SEE AT LEAST A CHANCE. MORNING RADAR IMAGERY
SHOWING LIGHT HIGH ELEVATION SHOWERS/VIRGA OVER AREAS MAINLY SOUTH
OF INTERSTATE 15...HOWEVER NOTHING HAS BEEN REPORTED OR MEASURED SO
FAR. DEW POINTS ARE STILL QUITE LOW OVER THE AREA SO IT WILL TAKE
SOME TIME FOR THE ATMOSPHERE TO BECOME SATURATED ENOUGH FOR
PRECIPITATION TO REACH THE SURFACE. OVERALL FORCING WITH THIS FIRST
WAVE IS PRETTY WEAK AND OUTSIDE OF SOME OF THE HIGHER ELEVATIONS
SEEING LIGHT SNOW ACCUMULATIONS...WINTER WEATHER PRODUCTS ARE NOT
NEEDED FOR TODAY.
IT LOOKS LIKE THERE WILL BE A BRIEF BREAK TONIGHT BETWEEN THIS FIRST
SYSTEM AND THE SECOND STRONGER SYSTEM WHICH WILL START TO IMPACT THE
AREA EARLY TUESDAY MORNING. PRECIPITATION TUESDAY MORNING WILL
MAINLY BE CONFINED TO THE SIERRA WHERE SNOW WILL BEGIN TO FALL. THE
CURRENT WINTER STORM WATCH FOR THE SIERRA GOES INTO EFFECT AT 4AM
TUESDAY...BUT LOOKING AT THE LATEST MODEL RUNS IT LOOKS LIKE
HEAVIEST SNOW WILL LIKELY BEGIN AFTER ABOUT 9AM. AT THIS TIME WILL
LET THE DAY SHIFT DETERMINE THE BEST TIMING AND WHETHER OR NOT TO
UPGRADE THE WATCH. THE TRAJECTORY OF THE TROUGH IS FAR ENOUGH SOUTH
THAT THE SIERRA WILL NOT BE ABLE TO INTERCEPT MOST OF THE
PRECIPITATION AND IT CONTINUES TO LOOK LIKE A GOOD WIDESPREAD
RAIN/SNOW EVENT FOR MUCH OF THE CWA FROM TUESDAY AFTERNOON THROUGH
WEDNESDAY MORNING. PRIOR TO THE PRECIPITATION...AREAS ACROSS THE
SOUTHERN HALF OF THE CWA COULD SEE AN INCREASE IN SOUTHWEST WINDS UP
TO 30 MPH...BUT AS THE PRECIPITATION BEGINS THESE WINDS WILL
DIMINISH. SNOW LEVELS WITH THIS SYSTEM ARE NOT PARTICULARLY LOW WITH
SNOW LEVELS GENERALLY REMAINING 5000 FEET AND HIGHER. LOCATIONS
BETWEEN 5000-7000 FEET COULD SEE SNOW AMOUNTS IN THE 3-7 INCH RANGE
WITH CLOSE TO A FOOT ABOVE 8000-9000 FEET. RAINFALL AMOUNTS IN THE
VALLEY ARE FORECAST TO RANGE FROM ABOUT A QUARTER TO HALF AN INCH
WITH SOME HIGHER AMOUNTS POSSIBLE.
PRECIPITATION IS FORECAST TO SHIFT EAST OVERNIGHT TUESDAY WITH
SHOWERS ENDING FROM WEST TO EAST BETWEEN MIDNIGHT AND 6AM AS A WEAK
VERY SHORT-LIVED SHORTWAVE RIDGE MOVES ACROSS THE REGION. THIS WILL
BE FOLLOWED BY A THIRD SYSTEM WHICH WILL IMPACT THE AREA WEDNESDAY.
WITH THE CLOUDS AND RAIN EXPECTED TEMPERATURES WILL REMAIN JUST A
FEW DEGREES BELOW NORMAL.
.LONG TERM...WEDNESDAY THROUGH SUNDAY.
ACTIVE PATTERN CONTINUES IN THE LONG TERM. FORECAST CONFIDENCE IS
VERY LOW AS MODEL AGREEMENT IS MARGINAL TO POOR...RUN-TO-RUN
VARIABILITY IS HIGH...AND FINE-SCALE DETAILS WILL BE CRITICAL TO
PREDICT LOCATION, TIMING, DURATION, AND QUANTITIES OF PRECIPITATION
ACCURATELY.
AFTER RAPID PASSAGE OF A SHORTWAVE RIDGE WEDNESDAY MORNING...NEXT IN
THE PARADE OF SYSTEMS MOVES IN BY WEDNESDAY AFTERNOON. THOUGH
VIRTUALLY ALL MODEL OUTPUT HAS THIS SYSTEM MOVING IN 18Z WEDNESDAY
TO 00Z THURSDAY...THERE ARE SUBTLE DIFFERENCES IN THE SMALLER-SCALE
VORTICITY MAXIMA AND THE ORIENTATION OF UPPER- AND MIDLEVEL FLOW
THAT MAKE THE FORECAST OF PRECIPITATION AND WINDS CHALLENGING.
PRECIPITATION OUTPUT IS TIED VERY CLOSELY TO PASSAGE OF THESE
EMBEDDED SHORTWAVE TROUGHS IN THE LONGWAVE TROUGH APPROACHING THE
AREA...THE TIMING OF WHICH OFTEN VERIFY POORLY IN SUCH PATTERNS.
NEVERTHELESS...SOME SIMILARITIES IN THE OUTPUT ARE APPARENT. THERE
APPEAR TO BE TWO DISTINCT VORT MAXIMA THAT MOVE THROUGH THE REGION
BETWEEN 18Z WEDNESDAY AND 00Z FRIDAY. THIS RESULTS IN AN INCREASE IN
PRECIPITATION FOR THE NORTHERN AND EASTERN CWA WITH THE FIRST WAVE
18Z WEDNESDAY TO 06Z THURSDAY AND THE SOUTHERN CWA WITH THE SECOND
AS THE LONGWAVE TROUGH AXIS APPROACHES THE AREA 12Z THURSDAY TO 00Z
FRIDAY. THE FIRST WAVE APPEARS TO BE MORE EFFECTIVELY BLOCKED BY THE
SIERRA THAN THE SECOND SINCE THE SIERRA TAKES A MUCH MORE DIRECT HIT
FROM THE FIRST. AS A RESULT...ASSOCIATED PRECIP OUTPUT WITH THE
FIRST WAVE IS FAIRLY LIGHT AND MOSTLY CONFINED TO THE SOUTHERN GREAT
BASIN AND MOHAVE COUNTY. THE SECOND WAVE PRODUCES MORE SUBSTANTIAL
PRECIPITATION FOR MUCH OF THE AREA ALONG AND SOUTHEAST OF I-15.
MEANWHILE, THE EASTERN SLOPES OF THE SOUTHERN SIERRA WILL LIKELY SEE
SOME...BUT NOT A LOT...OF SPILLOVER FROM THE BARRAGE OF VORT MAXIMA
MOVING INTO THE AREA DURING THIS PERIOD. SNOW LEVELS WILL GENERALLY
FALL FROM 4500-5500 FEET WEDNESDAY AFTERNOON TO 3500-4500 FEET BY
THURSDAY NIGHT.
FORECAST QPF FOR THE FIRST WAVE IS GENERALLY LESS THAN 0.25 INCHES
WITH THE HIGHEST AMOUNTS IN LINCOLN AND NORTHERN MOHAVE COUNTIES
(12Z WEDNESDAY TO 12Z THURSDAY). FOR THE SECOND WAVE TOTALS RANGE
FROM A TRACE TO 0.25 INCHES NORTH AND WEST OF I-15 TO 0.25-0.75
INCHES SOUTH AND EAST OF I-15 (12Z THURSDAY TO 12Z FRIDAY). SNOW
AMOUNTS WILL LIKELY BE FAR LESS THAN THE TUESDAY-EARLY WEDNESDAY
TIME PERIOD. THE HIGH SIERRA AND WHITES MAY SEE 4-8 INCHES WITH
LOWER AMOUNTS BELOW 8000 FEET. THE SPRINGS AND SHEEP RANGE MAY
ACCUMULATE 2-5 MORE INCHES...WITH THE SOUTHERN GREAT BASIN AND HIGH
TERRAIN OF MOHAVE COUNTY SEEING 1-4 INCHES. ALL OF THIS IS SAID WITH
THE AFOREMENTIONED LOW CONFIDENCE IN MIND...DETAILS REGARDING
TIMING, LOCATION, AND QUANTITY OF PRECIP THIS FAR OUT ARE SUBJECT TO
CONSIDERABLE CHANGE.
MODELS THEN HINT AT A THIRD WAVE ON THE UPSTREAM SIDE OF THE
LONGWAVE TROUGH MOVING THROUGH THE AREA THURSDAY NIGHT AND FRIDAY
MORNING. HOWEVER, AT THIS POINT, AGREEMENT IS QUITE POOR AMONG THE
GUIDANCE WITH THE GFS BEING MOST AGGRESSIVE WITH PRECIP FOR OUR AREA
AND THE CMC GIVING US BASICALLY NONE AT ALL. THIS SYSTEM WOULD BE A
NORTHWEST-FLOW TYPE EVENT, WHICH MEANS IT WILL BE A COLDER/SOMEWHAT
DRIER SYSTEM. THESE TYPES OF SYSTEMS ARE NOTORIOUSLY DIFFICULT TO
PREDICT SO FAR IN ADVANCE...PARTICULARLY THEIR ABILITY TO GENERATE
PRECIP IN OUR AREA. FOR NOW, JUST BROADBRUSHED PRECIP CHANCES WITH A
CLEAR NORTHWEST TO SOUTHEAST TREND IN THE GRIDS THROUGH FRIDAY. SNOW
LEVELS BY THIS POINT LOOK TO REACH 2500-4000 FEET.
BEYOND FRIDAY, NORTHWEST FLOW BECOMES FIRMLY ESTABLISHED AS A COLD
UPPER-LEVEL CYCLONE SETTLES INTO THE NORTHERN PLAINS AND SOUTHERN
CANADA. GIVEN THE WIDE RANGE OF MODEL SOLUTIONS WITH THIS LARGE-
SCALE FEATURE...AM EVEN LESS CONFIDENT DURING THIS PERIOD WITH THE
TIMING OF SMALLER-SCALE VORT MAXIMA MOVING THROUGH OUR AREA OVER THE
WEEKEND. GIVEN THAT THIS IS A DRIER PATTERN FOR OUR AREA...KEPT POPS
LOW WITH THE HIGHEST POPS FAVORING THE SIERRA AND THE HIGH TERRAIN
OF THE SOUTHERN GREAT BASIN. SINCE THE GFS/EURO ARE BOTH HINTING AT
PASSAGE BETWEEN SATURDAY NIGHT AND SUNDAY NIGHT...KEPT HIGHEST POPS
DURING THIS TIMEFRAME.
TEMPS DURING THE LONG TERM ARE EXPECTED TO BE NEAR TO SLIGHTLY BELOW
NORMAL GIVEN THE FREQUENT PASSAGE OF STORMS AND CONSIDERABLE
CLOUDINESS THROUGH FRIDAY AND THE COOLER NORTHWEST FLOW THEREAFTER.
&&
.SPOTTER INFORMATION STATEMENT...WHILE SPOTTER ACTIVATION IS NOT
EXPECTED...SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT
RAIN...SNOW...OR OTHER WEATHER-RELATED IMPACTS.
&&
$$
UPDATE/AVIATION...WOLCOTT
SHORT TERM........GORELOW
LONG TERM.........SHAFER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1058 AM CST MON JAN 4 2016
.UPDATE...
FOR 18Z AVIATION DISCUSSION.
&&
.SHORT TERM...
(TODAY-WED NIGHT)
EXPECTING A DRY FORECAST THRU WED NIGHT. ONLY TRUE QUANDARY FOR THE
SHORT TERM PERIOD CENTERS AROUND LOW LEVEL CLOUD DECK MOVING N TO
S ACROSS THE MID STATE AS THESE EARLY MORNING HOURS HAVE PROGRESSED.
THIS LOW LEVEL MOISTURE ADVECTION ASSOCIATED WITH BROAD UPPER LEVEL
TROUGHING INFLUENCES MOVING ACROSS THE REGION. HRRR MODEL SHOWING
MOST OF THIS LOW LEVEL CLOUDINESS HANGING AROUND DURING THE DAY...
AND CAN NOT REALLY ARGUE WHY IT WOULD NOT WITH THE LATEST 08Z KOHX
LAPS SOUNDING SHOWING A PRONOUNCED LOW LEVEL INVERSION IN PLACE
925MB TO 700MB...WITH REALLY NO SIGNIFICANT MIXING SOURCE IN SITE...
UNTIL BULK OF THIS LOW LEVEL MOISTURE SHIFTS EWD AS UPPER LEVEL
TROUGHING INFLUENCES MOVE EWD ALSO...AND DIURNAL HEATING INFLUENCES
LATE IN THE DAY MAY RESULT IN SOME BREAKAGE IN THE CLOUDINESS ACROSS
MAINLY ERN PORTIONS OF THE MID STATE.
A DECENT SFC PRESSURE GRADIENT IS EXPECTED ACROSS THE MID STATE DURING
THE MORNING HRS ALSO. WIND CHILLS DURING THIS TIME PERIOD IN THE LOW
TO MID 20S ARE CERTAINLY NOT OUT THE QUESTION...EVEN UPPER TEENS
POSSIBLE PLATEAU...THRU AT LEAST THE MID MORNING HRS. THUS...THOSE
PARTICIPATING IN OUTDOOR ACTIVITIES THRU THE MID MORNING HOURS...
ESPECIALLY FOR THOSE SCHOOL DISTRICT STARTING SCHOOL AFTER THEIR
WINTER BREAKS...TODAY...WITH CHILDREN/PARENTS WAITING AT SCHOOL
BUS PICKUP ZONES...SHOULD DRESS FOR THESE COLD WX CONDITIONS APPROPRIATELY.
WITH THE POSSIBILITY OF SOME CLOUD BREAKAGE LATE AFTERNOON...A LITTLE
HESITANT IN BEING AGGRESSIVE IN CUTTING DOWN AFTERNOON HIGH TEMPS
BY MULTIPLE DEGREES FROM GUIDANCE...AND DID GO BELOW A FEW DEGREES
BELOW MAV/MET GUIDANCE VALUES...BUT WENT MORE IN LINE WITH 08Z GFS
LAMP VALUES. THUS...HIGHS TODAY WILL BE ONLY IN THE MID 30S...AROUND
FREEZING PLATEAU...10 TO 15 DEGREES COOLER THAN SEASONABLE NORMAL
VALUES. THUS TOO...ON AVERAGE...SOME OF THE COLDEST HIGH TEMPS SO
FAR THIS WINTER SEASON WILL BE EXPERIENCED TODAY ACROSS THE MID STATE.
BUILDING UPPER LEVEL RIDGING INFLUENCES WILL MOVE INTO THE MID STATE
AS TONIGHT PROGRESSES...AND ALONG WITH INFLUENCES FROM ERN GREAT
LAKES CENTERED SFC HIGH PRESSURE SYSTEM...WILL ERODE ANY
REMAINING CLOUDINESS ACROSS THE MID STATE BY THE EARLY EVENING HRS
TONIGHT. THIS WILL RESULT IN MOCLR SKIES ACROSS OUR AREA...WITH
LOWS TONIGHT MAINLY IN THE LOWER 20S...UPPER TEENS PLATEAU.
UPPER LEVEL RIDGING INFLUENCES WILL CONTINUE TO BUILD ACROSS THE AREA...
ALONG WITH INFLUENCES OF SFC HIGH PRESSURE CENTERED ACROSS THE ERN
GREAT LAKES REGION BY TUE MORNING THAT WILL SHIFT TOWARD THE MID
ATLANTIC COASTLINE BY LATE TUE AFTERNOON. THIS WILL PROVIDE FOR A
WARMUP IN AFTERNOON TEMPS TO AROUND SEASONAL NORMAL VALUES BY TUE
AFTERNOON. HIGHS WILL BE MAINLY IN THE UPPER 40S...MID 40S PLATEAU.
LOWS TUE NIGHT WILL REBOUND MAINLY INTO THE LOWER 30S.
THE BRUNT OF THE UPPER LEVEL RIDGING INFLUENCES WILL THEN SHIFT EWD AS
TUE NIGHT THRU WED NIGHT PROGRESS...WITH SFC HIGH PRESSURE INFLUENCES
MOVING INTO THE NE U.S...BUT OTHER THAN A SLOW INCREASE IN ATM MOISTURE
THRU WED NIGHT EXPECTED...LEADING TO A TRANSITION TO MOCLDY SKIES BY
WED NIGHT...DRY CONDITIONS WILL CONTINUE. HIGHS WILL CONTINUE TO WARM
WITH HIGHS NOW APPROACHING TEN DEGREES ABOVE SEASONAL NORMAL VALUES
BY WEDNESDAY AFTERNOON...MAINLY IN THE LOWER 50S. LOWS WED NIGHT
WILL BE MAINLY IN THE MID 40S AND BE AS WARM AS SEASONAL NORMAL HIGHS
FOR THIS TIME OF YEAR.
.LONG TERM...
(THU-SUN)
THURSDAY`S WEATHER MAP WILL FEATURE A NEGATIVELY TILTED SHORTWAVE AXIS
WHICH WILL EXTEND FROM KS SE THROUGH THE LOWER MS VALLEY. PVA TO THE
NORTHEAST OF THIS AXIS WILL BE APPARENT AND SHOWER CHANCES WILL BE
SPREADING NORTHEAST TOWARD THE MID STATE. MEANWHILE...AT THE SFC...A
N-S COLD FRONT WILL BE PUSHING EASTWARD AND OFFER A CONTINUING LOW
CHANCE OF SHOWERS FRIDAY INTO SATURDAY.
SHOWALTER VALUES WILL APPROACH ZERO THU NT AND INTO FRIDAY. HOWEVER...
ISC SUPPORT IS NOT THERE TO INCLUDE ANY THUNDER. WILL THEREFORE OPT TO
KEEP THE ACTIVITY AS RAIN SHOWERS ONLY.
MOVING AHEAD...ON SATURDAY...A SHORTWAVE OVER TX WILL BE TAKING THE
SOUTHERN ROUTE EASTWARD. THIS WILL LEAD TO CYCLOGENESIS OVER THE
NORTHERN GULF. AREA OF BEST THERMAL ADVECTION TO THE EAST OF THE
SFC LOW VARIES FROM MODEL TO MODEL. THUS...TRACKING WILL BE AN
UNCERTAINTY. EURO APPEARS TO BE IN THE MIDDLE...VERSUS THE DGEX
AND GFS...AND TRACKS THE LOW NE OVER EAST TN. THUS...THAT WOULD BE
A MORE FAVORABLE SCENARIO FOR MORE GENEROUS RAINFALL TOTALS. WILL
GO AHEAD AND INCLUDE A 40 TO PERHAPS 50 PERCENT CHANCE OF SHOWERS
FOR SAT NT AND INTO SUNDAY.
FOR THE EXTENDED TEMPS...SOUTHERLY FLOW WILL BE THE RULE THROUGH
SATURDAY. UPPER PATTERN REVEALS ELEVATED HEIGHTS...THEREFORE...LOOK
FOR ABOVE NORMAL TEMPS...TO THE TUNE OF 15 TO 20 DEGREES OR SO.
AS THE SOUTHERN ENERGY SPAWNS CYCLOGENESIS OVER NORTHERN
GULF...WE WILL SEE COOLER AIR RETURN. BY SUNDAY...TEMPS WILL ONLY
BE ABOUT 8- 10 DEGREES ABOVE NORMAL.
A SNEAK PEAK...7 TO 10 DAYS OUT...A SERIES OF CANADIAN SFC HIGHS
WILL PLUNGE SOUTHEASTWARD. THE EURO AND GFS MODELS BOTH CONCUR.
UPPER LEVEL WIND COMPONENT LOOKS NORTHERLY AND THUS...PROBABLY A
BELOW NORMAL PRECIP AND TEMP PATTERN.
&&
.AVIATION...
18Z TAF DISCUSSION.
BNA/CKV/CSV...BAND OF LOW CLOUDS AND SCATTERED FLURRIES IS
CURRENTLY MOVING SOUTHWARD ACROSS MIDDLE TENNESSEE. CIGS SHOULD
REMAIN VFR, BUT THERE MAY BE A SWATH OF MVFR CLOUDS AT CKV THIS
AFTERNOON. AFTERWARDS, HIGH PRESSURE TO OUR NW WILL PUSH DRIER
AIR AND CLEAR SKIES INTO THE MID STATE, WITH WINDS DIMINISHING
AFTER 00Z.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........08
LONG TERM..................19
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
321 PM CST MON JAN 4 2016
.SHORT TERM...
.TONIGHT AND TUESDAY...FORECAST CONFIDENCE IS MEDIUM.
AREA OF VERY LIGHT LAKE EFFECT SNOW SHOWERS AND FLURRIES CONTINUE TO
MOVE SOUTHWESTWARD ACROSS THE FAR EASTERN COUNTIES. AS DELTA T
VALUES CONTINUE TO BECOME LESS FAVORABLE TOWARD EARLY
EVENING...THINK THAT THIS ACTIVITY WILL GRADUALLY WIND
DOWN. NOT EXPECTING ANY ADDITIONAL ACCUMULATIONS.
LAKE EFFECT CLOUDS SHOULD CONTINUE TO AFFECT THE EASTERN PORTIONS OF
THE AREA THIS EVENING...BEFORE LOW LEVEL WINDS WEAKEN AND SHIFT TO
THE SOUTH TO SOUTHWEST LATER TONIGHT. THESE CLOUDS SHOULD THEN
DISSIPATE OR PUSH BACK TO THE NORTHEAST LATER TONIGHT.
THERE IS UNCERTAINTY WITH HOW THE LOW STRATUS DECK OVER SOUTHERN
MINNESOTA INTO CENTRAL AND WESTERN IOWA WILL MOVE TONIGHT INTO
TUESDAY. 950 MB RAP HAS A DECENT HANDLE ON THIS CURRENT AREA...AND
SHIFTS IT SLOWLY NORTHEASTWARD TONIGHT INTO TUESDAY. IT DOES BRUSH
OUR FAR WESTERN COUNTIES TUESDAY MORNING. NOT SURE IF THIS DECK WILL
PUSH THAT FAR EAST...BUT WILL RAISE SKY COVER IN THE FAR WEST LATER
TONIGHT AND SPREAD IT EASTWARD INTO TUESDAY TO ACCOUNT FOR THIS
POSSIBILITY.
AS THE HIGH PUSHES EASTWARD TONIGHT INTO TUESDAY...WINDS WILL
GRADUALLY PICK UP OUT OF THE SOUTH TO SOUTHWEST...BECOMING GUSTY ON
TUESDAY. TEMPERATURES WILL DEPEND ON HOW MUCH CLOUD COVER REMAINS
OVER THE AREA...SO SOME UNCERTAINTY HERE AS WELL. FOR NOW...WENT
WITH MID TO UPPER TEENS TONIGHT...AND UPPER 20S TO AROUND 30 ON
TUESDAY.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE HIGH
THE UPPER FLOW BECOMES MORE SOUTHWEST WITH A VERY WEAK SHORTWAVE
APPROACHING SOUTHERN WISCONSIN WEDNESDAY THAT WEAKENS MORE AS IT
MOVES INTO THE AREA WEDNESDAY AFTERNOON. WEAK 700 MB UPWARD
MOTION CONTINUES. 700 MB RH SATURATES OVER SOUTH CENTRAL WISCONSIN
LATER IN THE AFTERNOON WITH FORECAST SOUNDINGS SHOWING THE
SATURATION ABOVE TO NEAR 300 MB. MOST OF THE MODELS ARE DRY WITH
AROUND A HUNDREDTH OF AN INCH OF PRECIPITATION JUST NORTHWEST OF
THE FORECAST AREA THROUGH THE AFTERNOON.
.WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH
A WEAK SOUTHWEST UPPER FLOW PERSISTS BEHIND THE EXITING VERY WEAK
SHORTWAVE WHILE THE MAIN SHORTWAVE TROUGH MOVES INTO THE CENTRAL
PLAINS WITH THE WEAK RIDGE AHEAD OF THE TROUGH MOVING INTO
SOUTHWEST WISCONSIN LATE.
THE SOUTH LOW LEVEL FLOW MOISTENS AND SATURATES THE LOWER LEVELS
AND LIGHT PRECIPITATION AFFECTS SOUTHERN WISCONSIN. THE GFS
FORECAST SOUNDINGS INDICATE MAINLY SNOW INITIALLY...ESPECIALLY
NORTH AREAS WITH SOME FREEZING RAIN POTENTIAL BECOMING MAINLY
LIGHT RAIN LATER THURSDAY.
.LONG TERM...
.THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
THE SHORTWAVE PUSHES INTO THE MID MISSISSIPPI VALLEY FRIDAY
MORNING WHICH IS A LITTLE FASTER AND WEAKER ON THE 00Z ECMWF.
LOW PRESSURE EXITS THE KANSAS/OKLAHOMA REGION FRIDAY MORNING WITH
A RATHER WEAK BROAD LOW ACROSS NORTHERN ILLINOIS TO SOUTHERN
WISCONSIN BY FRIDAY EVENING.
ON THE GFS THE PRECIPITATION TRENDS TOWARD MAINLY RAIN.
.FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
THE SHORTWAVE REACHES THE GREAT LAKES REGION FRIDAY NIGHT WITH A
SECOND SHORTWAVE SATURDAY ON THE ECMWF.
SURFACE LOW PRESSURE REACHES THE UPPER GREAT LAKES SATURDAY...WITH
THE 00Z ECMWF TRACK A LITTLE MORE WEST NEAR EASTERN LAKE SUPERIOR.
ON THE GFS THE PRECIPITATION TRENDS TURNS BACK TO MAINLY LIGHT SNOW
BY SATURDAY AS THE MID AND LOWER LEVELS COOL.
.SUNDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM.
A COLD MID/UPPER TROUGH DROPS DOWN FROM THE NORTHWEST SUNDAY AND
IS OVER THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES
MONDAY.
WHILE THE MODELS ARE MAINLY DRY...SOME VERY LIGHT SNOW OR FLURRIES
MAY OCCUR IN THE COLD NORTHWEST LOW LEVEL FLOW WITH A STRONG
RIDGE OF HIGH PRESSURE OVER THE NORTHERN PLAINS.
&&
.AVIATION/00Z TAFS/...
VERY LIGHT LAKE EFFECT SNOW SHOWERS AND FLURRIES SHOULD AFFECT
MILWAUKEE AND KENOSHA AT TIMES UNTIL AROUND 00Z TUESDAY. NO
ADDITIONAL ACCUMULATIONS ARE EXPECTED. CEILINGS MAY ALTERNATE
BETWEEN 2500 AND 3500 FEET ABOVE GROUND LEVEL. THESE CEILINGS
SHOULD LINGER INTO THE LATE EVENING AT THE EASTERN SITES...BEFORE
MOVING OFF TO THE NORTHEAST OR DISSIPATING.
OTHERWISE...HIGH PRESSURE OVER THE REGION WILL SLIDE TO THE EAST
TONIGHT AND TUESDAY. MOSTLY CLEAR SKIES ARE EXPECTED AT MADISON
INTO THIS EVENING. THERE IS UNCERTAINTY ON HOW FAR EAST THE LOW
STRATUS DECK OVER IOWA INTO SOUTHERN MINNESOTA WILL REACH LATER
TONIGHT INTO TUESDAY. KEPT THESE LOW CLOUDS OUT OF TAFS FOR NOW DUE
TO THE UNCERTAINTY.
NORTHEAST WINDS SHOULD GRADUALLY WEAKEN AND BECOME LIGHT
TONIGHT...BEFORE BECOMING GUSTY OUT OF THE SOUTH TO SOUTHWEST ON
TUESDAY.
&&
.MARINE...
CANCELLED THE CURRENT SMALL CRAFT ADVISORY ACROSS THE
NEARSHORE WATERS OF LAKE MICHIGAN...AS WINDS AND WAVES HAVE
FALLEN BELOW CRITERIA.
ISSUED ANOTHER SMALL CRAFT ADVISORY FROM 12Z TUESDAY UNTIL 15Z
WEDNESDAY...AS GUSTY SOUTH TO SOUTHWEST WINDS AND BUILDING WAVES ARE
EXPECTED WITH A TIGHT PRESSURE GRADIENT DEVELOPING. ANY HIGH WAVES
WOULD BE TOWARD OR OVER THE OPEN WATERS DURING THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 6 AM TUESDAY TO 9 AM CST WEDNESDAY FOR
LMZ643>646.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...WOOD
TUESDAY NIGHT THROUGH MONDAY...HENTZ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
312 PM CST MON JAN 4 2016
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 312 PM CST MON JAN 4 2016
AHHH YES...THE JOYS OF TRYING TO FORECAST FOG/STRATUS EVOLUTION IN
JANUARY WITH A WEAK SUN ANGLE AND HIGH PRESSURE NEARBY. THAT WILL BE
THE CHALLENGE OVERNIGHT AND INTO AT LEAST PART OF TUESDAY...WITH
OTHERWISE RATHER "QUIET" WEATHER WITH SAID HIGH GRADUALLY WORKING
THROUGH THE AREA. PER SATELLITE TRENDS AND EXPECTED STRENGTHENING
SOUTHERLY FLOW THROUGH THE NIGHT...HAVE TO BELIEVE MUCH OF THE
LINGERING STRATUS TO OUR SOUTHWEST WILL LIFT BACK NORTH...BUT MAYBE
HANG OVER THE WESTERN CWA THROUGH THE NIGHT (LOTS OF QUESTIONS MARKS
HERE). MEANWHILE...WE MAY HAVE TO DEAL WITH ADDITIONAL DEVELOPMENT
NEAR THE RIDGE CENTER ITSELF ACROSS CENTRAL/EASTERN WISCONSIN WITH
SOME CONTRIBUTION OF MOISTURE FROM LAKE MICHIGAN GIVEN INITIALLY
MORE EASTERLY FLOW TODAY. THAT STUFF MAY WELL LIFT NORTH QUICKLY
LATER TONIGHT AS WELL...BUT IT`S REALLY A TOUCH CALL. PROVIDED
CLOUDS DON`T GET IN THE WAY...STILL THINKING THERE`S A SHOT WE COULD
MAKE A RUN JUST ABOVE FREEZING DOWN IN THE MISSISSIPPI VALLEY
AREAS...BUT WITH GUSTY SOUTHERLY WINDS PER MIXING TO JUST SHY OF
900MB NOT MAKING IT FEEL VERY WARM.
OUTSIDE OF FOG/STRATUS...THE BIGGER CONCERN REMAINS LIGHT SNOW
POTENTIAL LATE WEDNESDAY INTO WEDNESDAY NIGHT. CURRENT RATHER ROBUST
UPPER TROUGH MOVING THROUGH SOUTHERN CALIFORNIA/NORTHERN BAJA REGION
SHOULD WEAKEN QUITE A BIT AS IT MAKES A RUN THROUGH BROAD UPPER
RIDGING IN OUR DIRECTION LATER WEDNESDAY. THE MOISTURE FETCH IS
RATHER LIMITED THOUGH PWAT VALUES PROGGED TO JUMP TOWARD THE 0.6
INCH RANGE HINT OF ITS PACIFIC ORIGIN. AS MENTIONED BY THE PREVIOUS
CREW...OVERALL FORCING IN THIS SYSTEM ISN`T ANYTHING TERRIBLY
IMPRESSIVE...THOUGH BROAD AND PERSISTENT DEEPER LAYER UPGLIDE SHOULD
GRADUALLY DRIVE TOP DOWN SATURATION. ONE AREA OF MORE PRONOUNCED
FORCING STILL LOOKS TO MAYBE CLIP THE NORTHERN CWA JUST SOUTH OF A
MORE ORGANIZED ALBEIT STILL WEAK AXIS OF MID LEVEL DEFORMATION IN
THE VICINITY OF LOW LEVEL TROUGHING. HOWEVER...STILL THINK MANY
AREAS WILL SEE AT LEAST A BRIEF PERIOD OF SOME LIGHT SNOW AS THAT
PERSISTENT UPGLIDE EVENTUALLY DOES LEAD TO SATURATION PER FORECAST
RAOBS...WITH MAYBE AN INCH OF ACCUMULATION (LOW SNOW-LIQUID RATIOS
GIVEN THE "WARM" AIRMASS).
ARRIVAL OF SHORTWAVE LOW/MID LEVEL RIDGING BY THURSDAY SHOULD
DELIVER A RETURN TO MAINLY DRY WEATHER...THOUGH DO HAVE SOME
CONCERNS ABOUT LINGERING LOWER LEVEL MOISTURE AS THE UPPER LEVELS
DRY OUT CONSIDERABLY. FORECAST SOUNDINGS THE PAST SEVERAL RUNS HAVE
BEEN HINTING AT SOME WEAKISH LIFT PERSISTING NEAR CLOUD TOP
LEVEL...SUPPORTING OF THE NOTION THAT THERE COULD BE SOME DRIZZLE
AND/OR FREEZING DRIZZLE DEVELOPMENT. THAT LOOKS MOST LIKELY THURSDAY
MORNING BEFORE LOW LEVEL RIDGING FOLDS IN BY AFTERNOON AND SHUTS
DOWN THE LIFT.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 312 PM CST MON JAN 4 2016
THE ACTIVE WEATHER PATTERN CONTINUES WITH A RATHER CLASSIC EL NINO
LOOK FOR A TIME GIVEN A STRONG SUBTROPICAL JET DOWN ALONG THE
SOUTHERN TIER OF STATES AND MEAN TROUGHING OVER THE WEST AND
SOUTHWEST EJECTING ADDITIONAL WAVES IN OUR DIRECTION. THE NEXT OF
THOSE WAVES LOOKS TO MAKE A MOVE THROUGH THE MID MISS VALLEY INTO
FRIDAY...WITH AN ASSOCIATED WEAKISH SURFACE WAVE TRACKING TOWARD
SOUTHERN LAKE MICHIGAN. THAT SLIGHT SOUTHERLY SHIFT IS A BIT OF A
CHANGE FROM 24 HOURS AGO...WITH ALSO MUCH MORE GUIDANCE AGREEMENT
THIS GO AROUND. MOISTURE TAP WITH THE SYSTEM CONTINUES TO LOOK
PRETTY DECENT WITH AN OPEN GULF WRAPPING IN PWAT VALUES UP NEAR 0.65
INCHES THIS FAR NORTH (MUCH BETTER TO THE SOUTH). HINTS OF A CLOSED
850-700MB CIRCULATION ADD CONFIDENCE THAT WE MAY SEE A PRETTY GOOD
BAND OF PRECIP WORK NORTH THROUGH THE AREA...WITH GUIDANCE
INDICATIONS OF 0.30-0.50 INCHES OF PRECIP. WITH THE SLIGHT SOUTHWARD
SHIFT...THERE DOES APPEAR (AT LEAST FOR THE MOMENT) TO BE SUFFICIENT
COLD AIR AROUND TO PRECLUDE ANY BIG WARM LAYER ISSUES ALOFT...WITH
EXACT PRECIP TYPE INSTEAD DRIVEN BY BOUNDARY LAYER TEMPS. PER
CURRENT TRENDS...THIS COULD END UP BEING AN ADVISORY LEVEL TYPE OF
EVENT...BUT STILL SEVERAL DAYS TO WATCH THINGS UNFOLD.
THEREAFTER...LOOK OUT BELOW! A RECENT SPLIT IN THE POLAR VORTEX
PATTERN NEAR THE POLE IS ALLOWING FOR PLENTY OF ARCTIC AIR TO SPREAD
SOUTHWARD THROUGH CANADA AND INTO RUSSIA AT THE MOMENT...WITH STRONG
SIGNALS PER THE CURRENT MJO REGIME AND LONGER RANGE GUIDANCE THAT WE
WILL SEE QUITE THE COLD PLUNGE INTO THE LOWER 48 SOMETIME INTO THE
WEEKEND AND EARLY NEXT WEEK. EXACT TIMING IS OF COURSE STILL A
LITTLE UNCERTAIN...BUT BY SUNDAY/MONDAY...CONFIDENCE IS FAIRLY HIGH
THAT TEMPS WILL STRUGGLE THROUGH THE SINGLE DIGITS (PERHAPS EVEN
STUCK BELOW ZERO IN SPOTS). WOULD ALSO THINK THERE WOULD BE A BURST
OF SNOW ALONG THE LEADING EDGE OF THE COLDER AIR GIVEN SUCH AN FGEN
RESPONSE...BUT WE CAN SORT OUT THOSE DETAILS AFTER WE GET THROUGH
THE NEXT COUPLE OF SYSTEMS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1100 AM CST MON JAN 4 2016
LIFR STRATUS/LOW VSBYS HAVE MIXED OUT AT KRST...WITH THE LOW CLOUDS
HANGING JUST WEST OF THE AIRPORT. TRENDS WOULD TEND TO FAVOR THIS
STAYING WEST THROUGH THE AFTERNOON...WITH SOME QUESTION WHETHER THE
CLOUDS WOULD ADVANCE BACK/REDEVELOP. RAP SUGGESTS IT
WOULD...HRRR/GFS DOES NOT. NAM WAITS UNTIL 12Z. VARIETY OF OPTIONS
KEEPS FORECAST CONFIDENCE LOW. NAM/GFS BOTH SUGGEST LOW CIGS
WOULD/COULD RETURN LATER TUE NIGHT AS THE FLOW BECOMES MORE
SOUTHWESTERLY.
WINDS WILL BE ON THE INCREASE OVERNIGHT AS THE PRESSURE GRADIENT
TIGHTENS. SEE SOME POTENTIAL FOR LLWS AT KLSE FOR A FEW HOURS...BUT
BORDERLINE ENOUGH TO ADD AT THIS TIME. IN ADDITION...SOME QUESTION
WHETHER FOG WOULD REDEVELOP TONIGHT. WITH WINDS INCREASING...DON/T
SEE SUB 1-2SM AS AN OPTION AT THIS TIME. MVFR MIGHT BE HARD PRESSED.
WILL LEAVE P6SM FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...LAWRENCE
LONG TERM...LAWRENCE
AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 AM CST MON JAN 4 2016
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 248 AM CST MON JAN 4 2016
THE FIRST CONCERN IS WITH WHAT THE CLOUD COVER IS GOING TO DO
TODAY. A NARROW AREA OF CLEARING HAS WORKED INTO THE WESTERN
SECTIONS BUT IS SURROUNDED BY THE LOW CLOUDS BOTH TO THE WEST AND
EAST. THE 04.06Z RAP 0.5KM RELATIVE HUMIDITY SUGGESTS THE CLOUDS
TO THE EAST OF THIS CLEARING SLOT WILL EVENTUALLY START MOVING
BACK TO THE WEST SO THAT THE CLOUDS COVER THE ENTIRE FORECAST AREA
AGAIN BY 12Z. HAVE TRENDED TOWARD THIS SOLUTION TO START THE DAY.
THE NEXT CONCERN IS WITH A THINNING AREA OF CLOUDS OVER NORTHEAST
WISCONSIN THAT THE RAP SUGGEST THEN WORKS INTO CENTRAL WISCONSIN
BY MID MORNING AND THE WORKS WEST ACROSS MOST OF THE AREA THROUGH
THE DAY. HAVE TRIED TO HANDLE THIS TREND BY SHOWING A DECREASE IN
THE CLOUDS OVER THE EASTERN SECTIONS DURING THE MORNING WITH A
DECREASING CLOUDS TREND FOR THE REST OF THE AREA THROUGH THE
AFTERNOON.
THE NEXT CHANCE FOR PRECIPITATION WILL COME WEDNESDAY AFTERNOON.
THE UPPER LEVEL RIDGE AXIS WILL SLIDE ACROSS THE REGION MONDAY
NIGHT AND TUESDAY SETTING UP A SOUTHWEST FLOW ALOFT. A SHORT WAVE
TROUGH WILL COME OUT THE ROCKIES AND MOVE ACROSS THE AREA
WEDNESDAY AFTERNOON AND NIGHT. THIS DOES NOT LOOK TO BE THAT
STRONG OF A SHORT WAVE TROUGH AND THE 04.00Z GFS ONLY SHOWS SOME
WEAK PV ADVECTION IN THE 500-300 MB LAYER. NOT A LOT OF
THERMODYNAMIC FORCING EITHER AS THERE IS NO FRONTOGENESIS AND
ABOUT 1 TO 3 UBAR/S OF UP GLIDE ON THE 285K ISENTROPIC SURFACE. IT
LOOKS LIKE A LOT OF THE FORCING FROM THIS WAVE WILL GO INTO
SATURATING THE COLUMN...WHICH SHOULD TAKE UNTIL THE AFTERNOON TO
OCCUR...AND THEN ONCE SATURATION IS ACHIEVED...THERE IS NOT A LOT
OF LIFT LEFT FOR PRECIPITATION PRODUCTION. WITH SATURATION NOT
OCCURRING UNTIL AFTERNOON...REMOVED THE SMALL SNOW CHANCES FROM
WEDNESDAY MORNING AND THEN KEPT THEM IN THE 20 TO 40 PERCENT RANGE
FOR THE AFTERNOON. THE BEST CHANCES FOR PRECIPITATION WILL
PROBABLY OCCUR WEDNESDAY EVENING WHEN THE WEAK FORCING FROM THE
WAVE AND ISENTROPIC UP GLIDE CAN WORK ON THE SATURATED COLUMN TO
PRODUCE SOME LIGHT SNOW AND RAISED THE CHANCES UP TO 50 PERCENT
ACROSS THE NORTHERN SECTIONS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 248 AM CST MON JAN 4 2016
THURSDAY LOOKS TO BE TRANSITION DAY WITH THE AREA BETWEEN SYSTEMS.
AS THE SHORT WAVE TROUGH FROM WEDNESDAY NIGHT MOVES OFF TO THE
EAST...THERE SHOULD BE A PERIOD OF SHORT WAVE RIDGING ALOFT THAT
MOVES ACROSS THE AREA. THE ISENTROPIC UP GLIDE DROPS OFF TO
VIRTUALLY NOTHING AS THE BEST AREA OF WARM AIR ADVECTION SHIFTS
EAST WITH THE DEPARTING SHORT WAVE TROUGH. IF THERE IS
PRECIPITATION AROUND THURSDAY...HAVE CONCERNS ON WHAT TYPE IT WILL
BE. THE GFS SOUNDINGS SHOW A LACK OF ICE IN THE CLOUDS AS DRYING
ALOFT OCCURS WITH THE SHORT WAVE RIDGING. THIS COULD LEAD TO A
PERIOD OF SOME FREEZING DRIZZLE UNTIL TEMPERATURES REACH THE
FREEZING MARK IN THE AFTERNOON. FOR NOW...WILL STAY WITH RAIN OR
SNOW BUT LATER FORECASTS MAY HAVE TO START CONSIDERING OTHER
PRECIPITATION TYPES.
THE NEXT SHORT WAVE TROUGH COMING TOWARD THE AREA IN THE SOUTHWEST
FLOW IS HANDLED PRETTY SIMILARLY BY THE GFS AND 04.00Z ECMWF WITH
THEM COMING INTO BETTER AGREEMENT THAT THIS SYSTEM SHOULD TRACK TO
THE SOUTH OF THE AREA. THERE ARE STILL MINOR DIFFERENCES ON THE
TIMING AND STRENGTH OF THIS SYSTEM...BUT LOOKING AT THE GFS
FORECAST SOUNDINGS...THE FARTHER SOUTH TRACK SHOULD NOT BRING IN
MUCH WARM AIR ALOFT OR PRESENT PROBLEMS WITH ICE IN THE CLOUDS.
THIS SHOULD KEEP THE PRECIPITATION TYPES CONTROLLED BY THE LOW
LEVEL THERMAL STRUCTURE AND WITH HIGHS FRIDAY EXPECTED TO BE THE
MIDDLE TO UPPER 30S...SHOULD SEE A MIX OF RAIN/SNOW OR ALL RAIN BY
THE AFTERNOON. ANOTHER SHORT WAVE TROUGH LOOKS TO TAKE A VERY
SIMILAR TRACK FOR SOME LOW END PRECIPITATION CHANCES FRIDAY NIGHT
INTO SATURDAY. THE MODELS THEN DIVERGE ON HOW STRONG THE NORTHERN
STREAM FLOW WILL BE WITH THE ECMWF WRAPPING UP A LARGE UPPER LEVEL
LOW OVER SOUTHERN CANADA WHILE THE GFS IS CONSIDERABLY WEAKER
WITH THIS FLOW AND KEEPS THE NORTHERN STREAM ENERGY STRUNG OUT IN
A TROUGH FROM HUDSON BAY ACROSS THE NORTHERN GREAT LAKES INTO THE
NORTHERN ROCKIES. BOTH MODELS AGREE THAT COLDER AIR WILL ARRIVE
OVER THE WEEKEND ONCE THE SURFACE LOW GOES BY WITH THE FRIDAY
NIGHT/SATURDAY SHORT WAVE TROUGH. SINCE THE ECMWF IS STRONGER WITH
THE NORTHERN STREAM IT SPREADS IN MORE COLD AIR AND SUGGESTS THE
HIGHS SUNDAY WOULD ONLY BE IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO WHILE THE GFS IS SOMEWHAT WARMER WITH HIGHS IN THE SINGLE
DIGITS AND TEENS ABOVE ZERO. FOR NOW...HAVE NOT GONE THAT COLD
WITH THE TEMPERATURES...BUT DID TREND THEM BELOW THE MODEL
CONSENSUS...ESPECIALLY ACROSS THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1100 AM CST MON JAN 4 2016
LIFR STRATUS/LOW VSBYS HAVE MIXED OUT AT KRST...WITH THE LOW CLOUDS
HANGING JUST WEST OF THE AIRPORT. TRENDS WOULD TEND TO FAVOR THIS
STAYING WEST THROUGH THE AFTERNOON...WITH SOME QUESTION WHETHER THE
CLOUDS WOULD ADVANCE BACK/REDEVELOP. RAP SUGGESTS IT
WOULD...HRRR/GFS DOES NOT. NAM WAITS UNTIL 12Z. VARIETY OF OPTIONS
KEEPS FORECAST CONFIDENCE LOW. NAM/GFS BOTH SUGGEST LOW CIGS
WOULD/COULD RETURN LATER TUE NIGHT AS THE FLOW BECOMES MORE
SOUTHWESTERLY.
WINDS WILL BE ON THE INCREASE OVERNIGHT AS THE PRESSURE GRADIENT
TIGHTENS. SEE SOME POTENTIAL FOR LLWS AT KLSE FOR A FEW HOURS...BUT
BORDERLINE ENOUGH TO ADD AT THIS TIME. IN ADDITION...SOME QUESTION
WHETHER FOG WOULD REDEVELOP TONIGHT. WITH WINDS INCREASING...DON/T
SEE SUB 1-2SM AS AN OPTION AT THIS TIME. MVFR MIGHT BE HARD PRESSED.
WILL LEAVE P6SM FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...RIECK