Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/28/13
AREA FORECAST DISCUSSION
NWS TAUNTON MA
739 AM EDT TUE MAR 26 2013
.SYNOPSIS...
A DISTANT OCEAN STORM WILL MOVE FURTHER AWAY FROM THE REGION TODAY.
UPPER LEVEL LOW BACKING IN FROM THE WEST WILL BRING CLOUDS AND
SCATTERED RAIN/SNOW SHOWERS LATE WEDNESDAY AND THURSDAY. THE REST OF
THIS WEEK SHOULD BE DRY WITH TEMPERATURES CLOSE TO OR A LITTLE BELOW
NORMAL.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
BULK OF SNOW/SLEET ASSOCIATED WITH THE MAIN LOW PRES WELL OFFSHORE
HAS MOVED AWAY FROM CAPE/ISLANDS IN THE LAST FEW HOURS. JUST A FEW
INTERIOR SNOW SHOWERS MOVING THROUGH THE REGION THIS MORNING INVOF
OF THE CONNECTICUT VALLEY. IT APPEARS THAT WITH UPPER LVL LOW
STILL GRADUALLY MOVING THROUGH SRN NEW ENGLAND EXPECT IT TO TAKE
SOME TIME FOR CLOUDS TO BREAK UP SAVE FOR EAST COASTAL LOCATIONS
TODAY. HAVE ADJUSTED TOWARD THE LATEST RAP WHICH SHOWS THIS TREND
WELL. OTHERWISE...HAVE UPDATED TEMPS/DWPTS AS WELL AS POPS AND WX
TO BETTER MATCH CURRENT TRENDS.
PREVIOUS DISCUSSION...
SCATTERED OCEAN EFFECT RAIN/SNOW SHOWERS ALONG WITH SOME SLEET
PELLETS ACROSS SOUTHEAST MA/RHODE ISLAND WILL BE WINDING DOWN EARLY
THIS MORNING. LITTLE IF ANY ACCUMULATIONS ARE ANTICIPATED.
OTHERWISE...GENERALLY A DRY DAY IS EXPECTED BUT WITH THE UPPER LEVEL
LOW LOCATED ACROSS NORTHERN NEW ENGLAND A SPOT SHOWER OR TWO WILL
REMAIN POSSIBLE INTO THE AFTERNOON. AREAL COVERAGE/DURATION OF
ANYTHING THAT DEVELOPS SHOULD BE QUITE LIMITED...SO WILL JUST COVER
IT WITH SLIGHT CHANCE POPS.
AN ABUNDANCE OF CLOUDS THIS MORNING SHOULD GIVE WAY TO SOME PARTIAL
SUNSHINE LATER THIS MORNING AND AFTERNOON...BUT STILL EXPECT AT
LEAST SCATTERED CUMULUS CLOUDS. HIGHS SHOULD RANGE FROM THE LOWER
TO MIDDLE 40S ACROSS THE HIGHER TERRAIN...TO THE UPPER 40S ACROSS
PORTIONS OF THE COASTAL PLAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...
MOST OF THE DIURNAL CLOUDS SHOULD DISSIPATE ALONG WITH DIMINISHING
WINDS. THIS SHOULD ALLOW LOW TEMPS TO FALL INTO THE 20S...TO THE
LOWER 30S WITH DRY WEATHER EXPECTED.
WEDNESDAY... A PIECE OF UPPER LEVEL ENERGY WILL DROP SOUTH FROM
NORTHERN NEW ENGLAND. THIS WILL ALLOW FOR CLOUDS TO INCREASE FROM
THE NORTH THROUGH THE DAY ON WED. A FEW SPOT SHOWERS WILL ALSO BE
POSSIBLE...BUT THE VAST MAJORITY OF THE DAY WILL BE DRY IN A GIVEN
LOCATION. THEREFORE...JUST INCLUDED SLIGHT CHANCE POPS FOR NOW.
HIGH TEMPS WILL RANGE FROM THE MIDDLE 40S ACROSS THE HIGHER TERRAIN
AND FROM THE UPPER 40S TO AROUND 50 ON THE COASTAL PLAIN.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
OVERVIEW AND MODEL PREFERENCES...
26/00Z GUIDANCE IS IN FAIRLY GOOD AGREEMENT REGARDING THE
CONTINUATION OF STRONGLY BLOCKING PATTERN OVER WRN ATLANTIC AND
ERN CONUS. GIVEN THE BLOCKING...THE UPPER LVL LOW PRES ASSOCIATED
WITH THE SNOW/RAIN SHOWERS EARLY THIS MORNING WILL TAKE IT/S TIME
MOVING FURTHER OFFSHORE THROUGH THE WEEK. WITH MODELS IN DECENT
AGREEMENT THROUGH MUCH OF THIS WORK WEEK...WILL CONTINUE WITH THE
GFS/ECMWF BLEND SUPPORTED BY PREVIOUS LONG RANGE FORECASTERS. THE
ONLY CAVEAT HERE WILL THE POTENTIAL FOR A STRONGER LOW PRES AND
COLD FRONTAL SYSTEM FOR EARLY NEXT WEEK. AT THIS TIME...GIVEN THE
BLOCKED UPPER LVL FLOW...IT APPEARS THAT THE GFS MAY BE SHOWING
ITS TYPICAL FAST BIAS WITH THIS SYSTEM...SO WILL LEAN CLOSER TO
THE ECMWF TIMING...WHICH SUGGESTS PRECIPITATION IS MOST LIKELY
DURING THE DAY MON INTO MON NIGHT RATHER THAN SUN NIGHT INTO MON.
DETAILS...
WED NIGHT INTO THU NIGHT...
SLOW MOVING UPPER LVL LOW PRES WILL BE CONTINUING TO GRADUALLY
SHIFT TO THE E WITH TIME DURING THIS PERIOD. GIVEN THE MOISTURE
ASSOCIATED WITH THIS LOW...COMBINED WITH H5 TEMPERATURES DIPPING
TO SUB -30C...EXPECT MOSTLY UNSETTLED CONDITIONS TO CONTINUE WITH
A FAIR AMOUNT OF CLOUDS AND EVEN AN ISOLATED SHOWER OR TWO
POSSIBLE WED NIGHT INTO EARLY THU.
THU MID DAY INTO THU NIGHT...A STRONG SHORTWAVE WILL BE ROTATING
SW FROM THE MARITIMES. WHILE THIS WAVE WILL ACT AS THE KICKER TO
MOVE THE CUTOFF OFFSHORE...IT/S ASSOCIATED WITH A SFC COLD FRONT
WHICH WILL SWEEP FROM N TO S ACROSS THE REGION...ENHANCING LIFT
AND WORKING ON AVAILABLE MOISTURE. THEREFORE...WILL BE INCREASING
POPS DURING THIS PERIOD. P-TYPE WILL BE RELATED TO BOTH TIME OF
DAY AND PRECIPITATION INTENSITY. DURING THE DAY...HIGHER CHANCE
FOR RAIN UNLESS PRECIP RATES ARE HIGH ENOUGH TO FORCE A WETBULB
WITH DWPTS BELOW FREEZING SUPPORTING SOME SLEET/SNOW. ANY
LINGERING SHOWERS OVERNIGHT MAY BECOME MOSTLY SNOW/SLEET AS TEMPS
COOL. IN ANY CASE...QPF VALUES ARE EXPECTED TO BE BELOW 0.25
INCHES. TEMPERATURES GENERALLY JUST BELOW NORMAL THROUGH THE
PERIOD.
FRI INTO SUN...
MODEL GUIDANCE CONTINUES TO SUGGEST /WITH SUPPORT FROM CPC/ THAT
THE MID ATLANTIC /AND ERN CONUS/ BLOCKING PATTERN BEGINS TO BREAK
DOWN TOWARD THE BEGINNING OF APRIL. INITIALLY HIGH PRES WILL BE
BUILDING OVER THE REGION FROM THE W...WITH MOSTLY DRY CONDITIONS
AND H85 TEMPS RANGING FROM -2C TO ABOUT -5C WHICH WOULD YIELD
TEMPS CLOSE...TO POSSIBLY EVEN SLIGHTLY ABOVE NORMAL FOR LATE
MARCH AND EARLY APRIL. GUIDANCE DOES TRY TO PUSH ONE LAST
SHORTWAVE ASSOCIATED WITH THE CUTOFF THROUGH ON FRI...BUT IT WILL
BE A BALANCE AS TO WHETHER OR NOT DRY SUBSIDENCE CAN WIN OUT. FOR
NOW...WILL KEEP THE FORECAST MOSTLY DRY.
EARLY NEXT WEEK...
AT THIS TIME...IT STILL APPEARS THAT A STRONG WAVE AND ASSOCIATED
LOW PRES WILL PASS NW OF THE REGION DRAGGING A STRONG COLD FRONT
THROUGH THE REGION. USING THE ECMWF TIMING SUPPORTS PRECIPITATION
ONSET EARLY IN THE DAY MON...AND CONTINUING INTO EARLY MON NIGHT
FOLLOWED BY SOME COLDER TEMPERATURES THROUGH MID WEEK. WILL NEED
TO WATCH THIS...AS THERE DOES EXIST AT LEAST THE POTENTIAL FOR
SOME OCCASIONALLY HEAVY RAINFALL ASSOCIATED FRONTAL PASSAGE.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW...HIGH CONFIDENCE THROUGH WEDNESDAY AFTERNOON.
MOSTLY VFR AT TAF SITES THIS MORNING SAVE FOR SOME ISOLATED MVFR
CIGS AND VSBYS ASSOCIATED WITH WEAK SNOW SHOWERS JUST E OF THE CT
VALLEY. THESE WILL REMAIN ISOLATED THROUGH THE MORNING.
OTHERWISE...MAINLY VFR CIGS IN SCATTERED TO BROKEN CUMULUS CLOUDS
THROUGH WED. BRIEF PERIODS OF MVFR CIGS ARE STILL POSSIBLE THROUGH
WED ALONG WITH A SPOT SHOWER OR TWO...BUT VFR CONDITIONS SHOULD
DOMINATE.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEDNESDAY NIGHT-THURSDAY...GENERALLY VFR. POTENTIAL FOR MVFR IN
SCATTERED SHOWERS. MODERATE CONFIDENCE.
FRIDAY AND SATURDAY...VFR. HIGH CONFIDENCE.
&&
.MARINE...
HIGH CONFIDENCE THROUGH WEDNESDAY AFTERNOON.
TODAY...NORTHERLY WINDS WILL CONTINUE TO SLOWLY DIMINISH TODAY AS
OCEAN STORM MOVES NORTHEAST AND FURTHER AWAY FROM THE REGION. WILL
CONTINUE GALE WARNINGS JUST FOR THE WATERS SOUTHEAST OF NANTUCKET
UNTIL 7 AM THIS MORNING. OTHERWISE...NORTHERLY WIND GUSTS WILL
SLOWLY DIMINISH BUT STILL REMAIN AT SCA THRESHOLDS INTO THE
AFTERNOON ACROSS THE OUTER-WATERS. SEAS WILL ONLY SLOWLY DIMINISH
LATER THIS MORNING AND AFTERNOON...REMAINING ABOVE SCA THRESHOLDS
ACROSS THE OUTER-WATERS THROUGH THE AFTERNOON.
TONIGHT AND WEDNESDAY...LEFT OVER NORTHEAST SWELL WILL RESULT IN SCA
SEAS LINGERING ACROSS THE EASTERN OUTER-WATERS INTO EARLY WED
MORNING. AFTER THAT TIME...WINDS/SEAS SHOULD BE BELOW SCA
THRESHOLDS OVER ALL OUR WATERS.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WED NIGHT INTO THU NIGHT...MODERATE CONFIDENCE.
WINDS AND SEAS GRADUALLY INCREASE LATE WED NIGHT INTO THE DAY THU.
SEAS REACHING 5-7 FT OVER THE OUTER WATERS WITH WIND GUSTS AROUND
25 KT OVER ALL WATERS. SMALL CRAFT ADVISORIES LIKELY...BUT
CONDITIONS BEGIN TO SUBSIDE THU NIGHT.
FRI AND SAT...HIGH CONFIDENCE.
WINDS AND SEAS GENERALLY REMAIN BELOW SMALL CRAFT THRESHOLDS
THROUGH THE PERIOD AS HIGH PRES BUILDS OVER THE WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR
ANZ231>235-237.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ250-254-
255.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ251.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ256.
&&
$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
251 PM CDT TUE MAR 26 2013
.DISCUSSION...
ISSUED 240 PM CDT TUE MAR 26 2013
SHORT TERM...TONIGHT THROUGH FRIDAY
TEMPERATURES OVER THE SNOW COVERED AREAS OF CENTRAL IL THE MAIN
FORECAST CHALLENGE THE NEXT SEVERAL DAYS.
RATHER QUIET WEATHER PATTERN FOR OUR AREA AS NORTHWEST FLOW DOMINATES
WITH ONLY MINOR UPPER LEVEL SHORTWAVES EXPECTED TO PASS CLOSE TO THE
REGION. SURFACE RIDGE AXIS...CURRENTLY TO OUR WEST...WILL SHIFT OVER
THE MIDWEST ON WEDNESDAY AND EDGE TO OUR EAST BY LATE THURSDAY INTO
FRIDAY. MODELS SUGGEST A BIT MORE SIGNIFICANT WAVE TO DROP SOUTHEAST
ALONG A TIGHT BAROCLINIC ZONE TO OUR SOUTHWEST LATE WED NIGHT INTO
THURSDAY...BRINGING AN INCREASE IN CLOUDS AND THREAT FOR RAIN OVER
PARTS OF MO INTO SOUTHERN IL. AIR MASS IN OUR REGION APPEARS TO BE
TOO DRY TO SUPPORT PRECIP WITH THIS PARTICULAR DISTURBANCE BASED ON
SOUNDINGS OVER OUR SOUTH AND SOUTHWEST...SO WILL KEEP LATE WED AND
THURSDAY DRY.
NEXT UPPER LEVEL SHORTWAVE TRACKING EVEN FURTHER TO OUR SOUTHWEST
ON FRIDAY WITH PRECIP FROM THAT SYSTEM OCCURRING OVER PARTS OF
SOUTHERN MISSOURI AND THE SOUTHERN TIP OF IL DURING THE DAY...WHILE
FURTHER NORTH IN OUR AREA...SURFACE HIGH PRESSURE WILL SLOWLY PUSH
AWAY FROM THE STATE.
TRENDING CLOSER TO THE COOLER TEMP GUID (USUALLY THE MET GUID) FOR
DAYTIME HIGHS...EXCEPT FOR THE SOUTHEAST...AND A MAVMET BLEND AT
NIGHT LOOKS REASONABLE DURING THIS PERIOD.
LONG TERM...SATURDAY THROUGH TUESDAY
FLAT W-NW FLOW PATTERN FORECAST TO UNDERGO SOME SIGNIFICANT CHANGES
EARLY NEXT WEEK AS A SERIES OF SHORTWAVES EXPECTED TO CARVE OUT
ANOTHER STRONG UPPER LEVEL TROF OVER THE GREAT LAKES BRINGING A
SHOT OF COLD AIR BACK INTO OUR AREA.
JUST AHEAD OF THE TROF LATE SATURDAY INTO SUNDAY...RAIN CHANCES
WILL START TO INCREASE AHEAD OF THE APPROACHING COLD FRONT. MILD
TEMPS SHOULD HOLD ON SATURDAY AND A PART OF SUNDAY AHEAD OF THE
FRONT...HOWEVER...ONCE THE FRONT SWEEPS THROUGH THE AREA LATER
SUNDAY INTO SUNDAY NIGHT...MUCH COLDER WEATHER TO SETTLE IN FOR
EARLY NEXT WEEK AS CANADIAN HIGH PRESSURE SHIFTS SOUTHEAST INTO
THE MIDWEST. WITH THE COLD AIR IN PLACE...MODELS INDICATING A
SOUTHERN STREAM WAVE PUSHING ACROSS CALIFORNIA SUNDAY NIGHT WILL
SHIFT EAST INTO THE CENTRAL PLAINS TUESDAY AND BEGIN SPREADING
PRECIP BACK NORTH AND EAST INTO THE COLD AIR MASS. JUST HOW FAR
NORTH AND EAST THE PRECIP GETS IS BEING HANDLED DIFFERENTLY BY
MEDIUM RANGE MODELS WITH THE GFS APPEARING TO BE TOO AGGRESSIVE IN
BRINGING THE PRECIP NORTH INTO A MORE CONFLUENT FLOW ALOFT...
WHILE THE ECMWF WAS MORE CONSERVATIVE IN TIMING AND NORTHWARD
EXTENT TUE/TUESDAY NIGHT. AT THIS POINT...THE ECMWF LOOKS MORE
REASONABLE WITH HOW IT IS HANDLING THE SOUTHERN STREAM SYSTEM
IN THE AMPLIFIED FLOW PATTERN...SO WILL KEEP TUESDAY DRY AT THIS
TIME.
TEMPERATURES START OUT CLOSE TO OR JUST BELOW NORMAL SATURDAY AND
SUNDAY...BEFORE A RETURN TO SOME RATHER CHILLY TEMPERATURES AGAIN
EARLY NEXT WEEK.
SMITH
&&
.AVIATION...
ISSUED 104 PM CDT TUE MAR 26 2013
MAIN TAF CONCERN WILL BE THE RETURN OF CLOUDS TO CENTRAL AND
EASTERN IL THIS AFTERNOON...AND THEN THE TIMING ON THE DISSIPATION
OF CLOUDS TONIGHT.
THE HRRR MODEL HAS DONE A GOOD JOB WITH DEPICTING THE RETURN OF
CLOUDS TO NW AND WEST CENTRAL IL EARLY THIS AFTERNOON. SATELLITE
LOOPS SHOW THAT THE LEADING EDGE OF THESE CLOUDS IS ROTATING DOWN
FROM NORTHERN IL TOWARD THE I-74 CORRIDOR AT 17Z. THE CEILINGS ARE
EXPECTED TO BE ON THE LOWER END OF VFR...AND HAVE DECIDED TO DROP
THEM INTO THE MVFR CATEGORY AT PIA AND BMI BY THIS EVENING. THE
CLOUDS WILL GRADUALLY SPREAD TOWARD THE I-72 CORRIDOR LATER THIS
AFTERNOON.
THE CONCERN THEN SHIFTS TO THE DISSIPATION OF THE CLOUDS. THE NAM
KEEPS CEILINGS GOING FOR THE NEXT 24-36 HOURS...WHILE THE GFS
SCATTERS THE LOWER CLOUDS OUT BEFORE 06Z TONIGHT. THE NAM SEEMS TO
BE HOLDING ON TO THE LOW LEVEL MOISTURE WAY TOO LONG...WHILE THE
GFS MAY BE A BIT QUICK. WITH THE SHORTWAVE ENERGY ROTATING THROUGH
THE GREAT LAKES DURING THE EVENING INTO EARLY TONIGHT WILL KEEP
THE BROKEN CLOUDS GOING UNTIL A FEW HOURS BEFORE DAYBREAK.
THE NEXT SHORTWAVE WILL BE APPROACHING FROM THE NORTHERN PLAINS VERY
CLOSE TO DAYBREAK AND MOVING THROUGH DURING THE MORNING WITH
MAINLY HIGH CLOUDS..BUT INCREASING LOW LEVEL SUBSIDENCE WHICH
SHOULD RESULT IN SCATTERED LOW LEVEL CLOUDS AND NO PRECIPITATION.
MILLER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
102 PM CDT TUE MAR 26 2013
.DISCUSSION...
ISSUED 1049 AM CDT TUE MAR 26 2013
MADE SOME MINOR ADJUSTMENTS TO THE FORECAST FOR SKY COVER AND
TWEAKED TEMPERATURES A BIT FOR THIS AFTERNOON. THE LATEST VISIBLE
SATELLITE SHOWING A CLEAR SKY ALONG AND WEST OF THE IL RIVER..WITH
PARTLY SUNNY CONDITIONS BETWEEN I-55 AND I-57 AND CLOUDY
CONDITIONS IN THE EAST AND SOUTHEAST. THE MODELS HAVE DONE A POOR
JOB OF FORECASTING THE LOW LEVEL MOISTURE FIELDS AND CLOUDS...WITH
THE EXCEPTION OF THE HRRR WHICH NAILED THE CLEARING TRENDS.
SATELLITE AND THE HRRR BOTH INDICATE THAT CLOUDS WILL ADVECT/FILL
BACK IN ACROSS WEST CENTRAL AND CENTRAL IL THIS AFTERNOON.
&&
.AVIATION...
ISSUED 104 PM CDT TUE MAR 26 2013
MAIN TAF CONCERN WILL BE THE RETURN OF CLOUDS TO CENTRAL AND
EASTERN IL THIS AFTERNOON...AND THEN THE TIMING ON THE DISSIPATION
OF CLOUDS TONIGHT.
THE HRRR MODEL HAS DONE A GOOD JOB WITH DEPICTING THE RETURN OF
CLOUDS TO NW AND WEST CENTRAL IL EARLY THIS AFTERNOON. SATELLITE
LOOPS SHOW THAT THE LEADING EDGE OF THESE CLOUDS IS ROTATING DOWN
FROM NORTHERN IL TOWARD THE I-74 CORRIDOR AT 17Z. THE CEILINGS ARE
EXPECTED TO BE ON THE LOWER END OF VFR...AND HAVE DECIDED TO DROP
THEM INTO THE MVFR CATEGORY AT PIA AND BMI BY THIS EVENING. THE
CLOUDS WILL GRADUALLY SPREAD TOWARD THE I-72 CORRIDOR LATER THIS
AFTERNOON.
THE CONCERN THEN SHIFTS TO THE DISSIPATION OF THE CLOUDS. THE NAM
KEEPS CEILINGS GOING FOR THE NEXT 24-36 HOURS...WHILE THE GFS
SCATTERS THE LOWER CLOUDS OUT BEFORE 06Z TONIGHT. THE NAM SEEMS TO
BE HOLDING ON TO THE LOW LEVEL MOISTURE WAY TOO LONG...WHILE THE
GFS MAY BE A BIT QUICK. WITH THE SHORTWAVE ENERGY ROTATING THROUGH
THE GREAT LAKES DURING THE EVENING INTO EARLY TONIGHT WILL KEEP
THE BROKEN CLOUDS GOING UNTIL A FEW HOURS BEFORE DAYBREAK.
THE NEXT SHORTWAVE WILL BE APPROACHING FROM THE NORTHERN PLAINS VERY
CLOSE TO DAYBREAK AND MOVING THROUGH DURING THE MORNING WITH
MAINLY HIGH CLOUDS..BUT INCREASING LOW LEVEL SUBSIDENCE WHICH
SHOULD RESULT IN SCATTERED LOW LEVEL CLOUDS AND NO PRECIPITATION.
MILLER
&&
.PREV DISCUSSION...
ISSUED 245 AM CDT TUE MAR 26 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
MAIN TROF AXIS HAS SHIFTED SOUTH OF THE CWA WITH LINGERING
FLURRIES EXITING THE SE CWA EARLY THIS MORNING. PLENTY OF STRATOCU
OVERHEAD AND UPSTREAM AND WITH CYCLONIC LOW LEVEL FLOW CONTINUING
TODAY MOSTLY CLOUDY SKIES EXPECTED. SOME CLEARING NOTED ON IR SAT
IMAGERY OVER NRN IA/SRN MN SO SOME BREAKS FOR SUN CERTAINLY
POSSIBLE. LITTLE AIRMASS CHANGE FROM YESTERDAY AND HAVE HIGHS IN
THE MID/UPPER 30S. AN ELONGATED HIGH PRESSURE RIDGE WILL SHIFT EAST INTO
THE MISSISSIPPI VALLEY TONIGHT. IF SUBSIDENCE IS STRONG
ENOUGH TO PROVIDE SOME CLEARING LOW 20S OR EVEN SOME UPPER TEENS
LOWS POSSIBLE WITH SNOW COVER IN PLACE...HOWEVER FEEL CLOUDS MAY
HANG TOUGH WITH BETTER SUBSIDENCE TO OUR WEST SO WENT MORE
CONSERVATIVE LOW/MID 20S LOWS. BOTH NAM/GFS FORECAST SOUNDINGS
STILL SHOW MOISTURE TRAPPED BELOW A STRONG SUBSIDENCE INVERSION
UNDER THE IN-BUILDING RIDGE ON WEDNESDAY. SO WILL BE PESSIMISTIC
WITH CLEARING TRENDS THOUGH STRONGER LATE MARCH SUN COULD BREAK UP
THE CLOUDS FOR MORE OF A PARTLY SUNNY AFTERNOON. A GRADUAL WARMING
TREND WILL BEGIN AND MOST AREAS SHOULD SEE HIGHS IN THE LOWER 40S.
LONG TERM...THURSDAY THROUGH MONDAY
THE SURFACE RIDGE WILL BE THE DOMINANT FEATURE THROUGH THE END OF
THE WEEK AS IT GRADUALLY SHIFTS EAST INTO THE GREAT LAKES. SLOWLY
RISING HEIGHTS ALONG WITH SNOW MELT/MORE BARE GROUND WILL ALLOW
READINGS TO CLIMB A FEW DEGREES BOTH THU AND FRI. A DEVELOPING MID
LEVEL BAROCLINIC ZONE AND SFC WARM FRONT OVER THE MISSOURI
VALLEY...SHOULD KEEP ANY RAIN AND MOST OF THE CLOUD COVER WELL TO
OUR SOUTHWEST. BY SATURDAY THE HIGH SHIFTS EAST INTO THE
APPALACHIANS ALLOWING SOUTHERLY LLVL FLOW TO BRING EVEN WARMER AIR
INTO THE AREA WITH HIGHS EXPECTED INTO THE 50S. AN UPPER LEVEL
TROF MOVING INTO THE NORTHERN PLAINS WILL HELP DRIVE A COLD FRONT
INTO THE MIDWEST SATURDAY. 00Z GUIDANCE HAS SPED UP THE TIMING OF
THIS SYSTEM BY A SEVERAL HOURS...BUT MOST RAIN SHOULD BE ALONG AND
BEHIND THE FRONT. THUS HIGHEST RAIN CHANCES WILL BE SATURDAY NIGHT
AND SUNDAY MORNING. WITH LIMITED GULF MOISTURE ENTRAINED INTO THE
SYSTEM LIGHT AMOUNTS ARE EXPECTED. THE EXTENT OF THE COOL DOWN
BEHIND THIS FRONT IS IN QUESTION AS THE LONGER RANGE MODELS DIFFER
IN HOW FAR SOUTH THE SOUTHERN EXTENSION OF THE POLAR VORTEX DIGS
TOWARDS THE GREAT LAKES. MORE AGGRESSIVE GFS FAVORS A RETURN TO
WELL BELOW NORMAL TEMPS...WHILE THE ECMWF PUSHES THE BRUNT OF THE
COLD AIR OFF TO OUR NORTHEAST. FOR NOW WILL KEEP A BLENDED
FORECAST WITH TEMPS A FEW DEGREES BELOW NORMAL FOR THE BEGINNING
OF NEXT WEEK.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1050 AM CDT TUE MAR 26 2013
.DISCUSSION...
ISSUED 1049 AM CDT TUE MAR 26 2013
MADE SOME MINOR ADJUSTMENTS TO THE FORECAST FOR SKY COVER AND
TWEAKED TEMPERATURES A BIT FOR THIS AFTERNOON. THE LATEST VISIBLE
SATELLITE SHOWING A CLEAR SKY ALONG AND WEST OF THE IL RIVER..WITH
PARTLY SUNNY CONDITIONS BETWEEN I-55 AND I-57 AND CLOUDY
CONDITIONS IN THE EAST AND SOUTHEAST. THE MODELS HAVE DONE A POOR
JOB OF FORECASTING THE LOW LEVEL MOISTURE FIELDS AND CLOUDS...WITH
THE EXCEPTION OF THE HRRR WHICH NAILED THE CLEARING TRENDS.
SATELLITE AND THE HRRR BOTH INDICATE THAT CLOUDS WILL ADVECT/FILL
BACK IN ACROSS WEST CENTRAL AND CENTRAL IL THIS AFTERNOON.
TEMPERATURES WILL BE TRICKY DUE TO SKY COVER FLUCTUATIONS AND SNOW
COVER...WHICH IS RAPIDLY DECREASING IN SOME AREAS DUE TO COMPACTION
...THE SUNSHINE AND CURRENT READINGS IN THE MID 30S. WILL
GENERALLY STICK TO A 35-40 RANGE FOR MOST AREAS THIS AFTERNOON.
WILL KEEP SCATTERED FLURRIES GOING FOR THE REST OF THE MORNING
INTO EARLY AFTERNOON IN EASTERN IL. NO RECENT REPORTS OF FLURRIES
HAVE BEEN RECEIVED...BUT RADAR INDICATED PATCHES EAST OF A CMI-
MTO-ROBINSON LINE.
MILLER
&&
.AVIATION...
ISSUED 655 AM CDT TUE MAR 26 2013
VFR CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE CENTRAL IL
TERMINAL AIRPORTS THROUGH 12Z/7 AM WED. BROKEN TO OVERCAST
CEILINGS OF 3.5-6K FT TO OCCUR INTO THIS EVENING...AND THEN SCATTERED
OUT FROM NW TO SE OVERNIGHT. FLURRIES SHOULD STAY NE OF I-74 TODAY
AND INTO INDIANA. CLEARING LINE WORKING ITS WAY SE INTO FAR NW IL
EARLY THIS MORNING...BUT EXPECT LOW CLOUDS TO FILL BACK IN LATER
THIS MORNING AND AFTERNOON BEFORE DECREASING AGAIN DURING TONIGHT.
NW WINDS 8-13 KTS TODAY TO DIMINISH TO 4-8 KTS THIS EVENING AND
LIGHT OVERNIGHT AS 1031 MB HIGH PRESSURE RIDGE OVER THE GREAT
PLAINS TO DRIFT EAST INTO THE MS VALLEY BY DAWN WED.
07
&&
.PREV DISCUSSION...
ISSUED 245 AM CDT TUE MAR 26 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
MAIN TROF AXIS HAS SHIFTED SOUTH OF THE CWA WITH LINGERING
FLURRIES EXITING THE SE CWA EARLY THIS MORNING. PLENTY OF STRATOCU
OVERHEAD AND UPSTREAM AND WITH CYCLONIC LOW LEVEL FLOW CONTINUING
TODAY MOSTLY CLOUDY SKIES EXPECTED. SOME CLEARING NOTED ON IR SAT
IMAGERY OVER NRN IA/SRN MN SO SOME BREAKS FOR SUN CERTAINLY
POSSIBLE. LITTLE AIRMASS CHANGE FROM YESTERDAY AND HAVE HIGHS IN
THE MID/UPPER 30S. AN ELONGATED HIGH PRESSURE RIDGE WILL SHIFT EAST INTO
THE MISSISSIPPI VALLEY TONIGHT. IF SUBSIDENCE IS STRONG
ENOUGH TO PROVIDE SOME CLEARING LOW 20S OR EVEN SOME UPPER TEENS
LOWS POSSIBLE WITH SNOW COVER IN PLACE...HOWEVER FEEL CLOUDS MAY
HANG TOUGH WITH BETTER SUBSIDENCE TO OUR WEST SO WENT MORE
CONSERVATIVE LOW/MID 20S LOWS. BOTH NAM/GFS FORECAST SOUNDINGS
STILL SHOW MOISTURE TRAPPED BELOW A STRONG SUBSIDENCE INVERSION
UNDER THE IN-BUILDING RIDGE ON WEDNESDAY. SO WILL BE PESSIMISTIC
WITH CLEARING TRENDS THOUGH STRONGER LATE MARCH SUN COULD BREAK UP
THE CLOUDS FOR MORE OF A PARTLY SUNNY AFTERNOON. A GRADUAL WARMING
TREND WILL BEGIN AND MOST AREAS SHOULD SEE HIGHS IN THE LOWER 40S.
LONG TERM...THURSDAY THROUGH MONDAY
THE SURFACE RIDGE WILL BE THE DOMINANT FEATURE THROUGH THE END OF
THE WEEK AS IT GRADUALLY SHIFTS EAST INTO THE GREAT LAKES. SLOWLY
RISING HEIGHTS ALONG WITH SNOW MELT/MORE BARE GROUND WILL ALLOW
READINGS TO CLIMB A FEW DEGREES BOTH THU AND FRI. A DEVELOPING MID
LEVEL BAROCLINIC ZONE AND SFC WARM FRONT OVER THE MISSOURI
VALLEY...SHOULD KEEP ANY RAIN AND MOST OF THE CLOUD COVER WELL TO
OUR SOUTHWEST. BY SATURDAY THE HIGH SHIFTS EAST INTO THE
APPALACHIANS ALLOWING SOUTHERLY LLVL FLOW TO BRING EVEN WARMER AIR
INTO THE AREA WITH HIGHS EXPECTED INTO THE 50S. AN UPPER LEVEL
TROF MOVING INTO THE NORTHERN PLAINS WILL HELP DRIVE A COLD FRONT
INTO THE MIDWEST SATURDAY. 00Z GUIDANCE HAS SPED UP THE TIMING OF
THIS SYSTEM BY A SEVERAL HOURS...BUT MOST RAIN SHOULD BE ALONG AND
BEHIND THE FRONT. THUS HIGHEST RAIN CHANCES WILL BE SATURDAY NIGHT
AND SUNDAY MORNING. WITH LIMITED GULF MOISTURE ENTRAINED INTO THE
SYSTEM LIGHT AMOUNTS ARE EXPECTED. THE EXTENT OF THE COOL DOWN
BEHIND THIS FRONT IS IN QUESTION AS THE LONGER RANGE MODELS DIFFER
IN HOW FAR SOUTH THE SOUTHERN EXTENSION OF THE POLAR VORTEX DIGS
TOWARDS THE GREAT LAKES. MORE AGGRESSIVE GFS FAVORS A RETURN TO
WELL BELOW NORMAL TEMPS...WHILE THE ECMWF PUSHES THE BRUNT OF THE
COLD AIR OFF TO OUR NORTHEAST. FOR NOW WILL KEEP A BLENDED
FORECAST WITH TEMPS A FEW DEGREES BELOW NORMAL FOR THE BEGINNING
OF NEXT WEEK.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1243 AM CDT TUE MAR 26 2013
.DISCUSSION...
819 PM CDT
LAKE EFFECT SNOW SHOWERS CONTINUE TO STREAM ONSHORE ACROSS
SOUTHEAST COOK...LAKE...AND PORTER COUNTIES. LATEST RADAR TRENDS
AND OBS SHOW SOME BETTER ORGANIZATION WHICH IS SUPPORTED BY NEAR
TERM RAP SOUNDINGS THAT SHOW INVERSION HEIGHTS RISING CLOSER TO
7000 FT. 00Z GREEN BAY RAOB SHOWS AN INVERSION AROUND 6800 FT
WITH AN H85 TEMP AT -11C WITH LAKE WATER TEMP ROUGHLY AROUND +3C
YIELDING A 14C DIFFERENCE. LOW LEVEL WINDS HAVE BEGUN TO TURN MORE
NORTHWESTERLY...AT LEAST SLIGHTLY...OVER THE LAST FEW HOURS WHICH
SUPPORTS A GRADUAL EASTWARD SHIFT IN THE MORE FOCUSED ACTIVITY AND
BETTER RETURNS HAVE BEEN OCCURRING OVER PORTER COUNTY. OVERALL THE
GOING FORECAST REFLECTS THE ABOVE SO WILL ONLY MAKE MINOR TWEAKS
FOR NOW. STILL EXPECT THAT A FEW INCHES OF ACCUMULATION IS
POSSIBLE THROUGH THE OVERNIGHT ACROSS PORTER COUNTY BUT COVERAGE
OF ACCUMS MAY BE SOMEWHAT ISOLATED WITH MORE WIDESPREAD LIGHTER
AMOUNTS POSSIBLE GIVEN THE TRANSIENT NATURE OF THE BANDS.
ELSEWHERE...FLURRIES CONTINUE WITH NORTH-NORTHWEST WINDS EASING.
HAVE ADJUSTED TEMP TRENDS TO SUPPORT A SLOWER FALL INTO THE
OVERNIGHT.
MDB
//PREV DISCUSSION...
318 PM CDT
MAIN CONCERNS THIS FORECAST CYCLE ARE INITIALLY LAKE EFFECT SNOW
SHOWER TRENDS INTO TUESDAY...AND THEN TIMING OF NEXT COLD FRONT OVER
THE WEEKEND AND ASSOCIATED CHALLENGES OF TEMPS.
BROAD UPPER TROUGH DOMINATES THE EASTERN CONUS THIS AFTERNOON WITH
CLOSED LOW WHICH BROUGHT HEAVY SNOW TO THE MIDWEST ON SUNDAY/SUNDAY
NIGHT NOW PROPAGATING ACROSS THE MID-ATLANTIC REGION. SURFACE LOW
PRESSURE CONTINUES TO FILL OVER THE APPALACHIANS AS COASTAL LOW
DEEPENS OFF THE JERSEY SHORE...WITH BROAD AREA OF COOL CYCLONIC LOW
LEVEL FLOW TRAILING ACROSS THE GREAT LAKES AND MISSISSIPPI VALLEY
REGION. THIS HAS PRODUCED PERSISTENT FLURRIES/LIGHT SNOW SHOWERS
WITH STEEP LOW LEVEL LAPSE RATES...AS WELL AS LAKE EFFECT SNOW
SHOWERS WHICH HAVE GRADUALLY BECOME BETTER ORGANIZED THIS AFTERNOON.
LIGHT SNOW SHOWERS HAVE GENERALLY BEEN DECREASING ACROSS AREAS AWAY
FROM THE LAKE THIS AFTERNOON WITH WEAK SYNOPTIC SUBSIDENCE/HEIGHT
RISES IN THE WAKE OF THE SHEARED MID-LEVEL VORT DRIFTING SOUTH AWAY
FROM OUR AREA...THOUGH FORECAST SOUNDINGS SUPPORT CONTINUED STRATOCU
LINGERING TONIGHT WHICH WILL PROBABLY STILL PRODUCE SOME SCATTERED
INCONSEQUENTIAL FLURRIES AT TIMES. GUIDANCE DOES INDICATE A WEAK MID
LEVEL SHORT WAVE WILL APPROACH FROM THE NORTH/NORTHWEST LATE TONIGHT
AND WILL CROSS THE AREA TUESDAY MORNING...WHICH ALTHOUGH NO
SIGNIFICANT QPF IS INDICATED WILL LIKELY CONTINUE TO SUPPORT SOME
FLURRIES INTO TUESDAY MORNING. AS FOR THE LAKE EFFECT...BOUNDARY
LAYER WINDS ARE STARTING TO BACK FROM NORTHEAST TO MORE NORTHERLY...
AND WERE HELPING FOCUS CONVERGENCE FOR A NORTH-SOUTH LAKE-PARALLEL
BAND TO BECOME EVIDENT IN REGIONAL RADAR IMAGERY. WINDS CONTINUE TO
BACK GRADUALLY TO MORE NORTHWEST THROUGH TUESDAY MORNING WHICH
SHOULD ALLOW THIS BAND TO SHIFT ACROSS NORTHWEST INDIANA AND
EVENTUALLY EAST OF PORTER COUNTY AND OUT OF OUR CWA TUESDAY
AFTERNOON. THERMODYNAMIC PROFILES REMAIN FAIRLY MARGINAL FOR STRONG
LAKE EFFECT...WITH DELTA T VALUES GRADUALLY APPROACHING +14 OR SO
AND WITH EQUILIBRIUM LEVELS 6000-7000 FT. THUS WHILE ACCUMULATIONS
ARE NOT EXPECTED TO BE GREAT...WEAK LES EVENT IS EXPECTED TO PERSIST
AND HAVE BUMPED UP POPS ESPECIALLY OVER NORTHWEST INDIANA
TONIGHT/EARLY TUES. WITH LIGHT SNOW AND TEMPS ABOVE FREEZING NOT
MUCH ACCUMULATING ATTM...THOUGH ACCUMULATIONS OF AN INCH OR TWO ARE
LIKELY OVERNIGHT WITH SLIGHTLY COOLER TEMPS AND MORE ORGANIZED BAND.
BEYOND TUESDAY...UPPER FLOW REMAINS NORTHWEST WHILE HEIGHTS
GRADUALLY INCREASE AS EASTERN TROUGH SLOWLY MOVES AWAY. WEAK SURFACE
HIGH PRESSURE RIDGE MOVES INTO THE AREA BY LATE WEDNESDAY AND
THURSDAY WHICH WILL PROVIDE DRY WEATHER WITH SLOWLY MODERATING
TEMPS...LIKELY REACHING THE MID 40S BY THURSDAY.
GUIDANCE IS IN GOOD AGREEMENT IN DEPICTING AN UPPER TROUGH DROPPING
OUT OF CANADA AND AMPLIFYING ACROSS THE UPPER MIDWEST THIS WEEKEND.
SURFACE LOW PRESSURE INITIALLY DEVELOPS TO OUR NORTH/NORTHWEST ON
SATURDAY...WHICH ALLOWS OUR LOW LEVEL FLOW TO BECOME SOUTHERLY AS
THE SURFACE RIDGE DRIFTS AWAY TO THE EAST. WARMING COMMENCES... WITH
GUIDANCE INDICATING UPPER 40S/LOW 50S BY THE WEEKEND. MODELS REMAIN
A BIT CONFLICTED IN THE LONGER TERM WITH HOW QUICKLY THE COLD FRONT
ASSOCIATED WITH THE UPPER MIDWEST/LAKE LOW MOVES THROUGH HOWEVER.
THE GFS...WHILE CONSISTENT WITH ITSELF IS QUICKEST AND MOVES THE
FRONT THROUGH SATURDAY NIGHT...WHILE THE ECMWF BRINGS IT THROUGH
DURING THE DAY SUNDAY. THIS HAS SIGNIFICANT IMPLICATIONS ON TEMPS
ESPECIALLY SUNDAY...WITH ANOTHER DAY OF 50 DEGREE WARMTH ON SUNDAY
WITH THE SLOWER ECMWF SOLUTION. HAVE LEANED IN FAVOR OF THE USUALLY
CONSISTENT PERFORMING ECMWF...WITH 50S ACROSS THE SOUTHEAST 2/3 OR
SO OF THE CWA SUNDAY WITH NEAR 50 NORTHWEST CLOSER TO APPROACHING
FRONT. IN EITHER CASE...IT APPEARS THAT OUR THERMAL PROFILES WILL BE
WARM ENOUGH TO RESULT IN FRONTAL/PRE-FRONTAL PRECIP FALLING IN THE
FORM OF RAIN SATURDAY NIGHT INTO SUNDAY...PERHAPS MIXING WITH WET
SNOW BEFORE ENDING BEHIND THE FRONT SUNDAY NIGHT. EARLY NEXT WEEK
SHOWS EVEN BIGGER DIFFERENCES IN EVOLUTION OF PATTERN WITH THE GFS
REBUILDING WARMTH QUICKLY...WHILE THE ECMWF INDICATES MORE OF A COOL
DOWN BACK TO SUB-NORMAL TEMPS BEHIND THE FRONT MONDAY. 12Z EC NOT AS
COLD AS THE 00Z RUN...THOUGH HAVE AGAIN SHADED AWAY FROM THE 50S AS
PRODUCED BY THE GFS. WILL PULL FOR THE WARMER GFS SOLUTION HOWEVER!
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
*NONE.
TRS
//DISCUSSION...UPDATED 06Z...
LIGHT LAKE EFFECT SNOW SHOWERS CONTINUE JUST E OF THE IL SHORE OUT
TO MID-LAKE AND INTO FAR NORTHWEST IN. OFFSHORE OF THE IL. FLOW IN
LOWER LEVELS AND THROUGH THE DEPTH OF THE LAKE EFFECT CLOUDS IS TO
REMAIN BASICALLY OUT OF THE DUE NORTH DURING THE FIRST PART OF THE
OVERNIGHT BEFORE THEY BACK A BIT AND SHIFT TO LAKE EFFECT SNOW
SHOWERS FURTHER EAST ACROSS NORTHWEST IN AND TO FAR SOUTHWEST
LOWER MI AND NORTH CENTRAL IN DURING THE PREDAWN AND TUESDAY
MORNING.
PAIR OF UPPER LOW OVER NEW ENGLAND TO MERGE AS THEY CONTINUE TO
THE EAST ALONG AND OFF THE CANADIAN MARITIMES TODAY WHILE AN UPPER
RIDGE OVER WESTERN NOAM WEAKENS AND BROADENS AS IT MOVES TO THE
NORTHERN AND CENTRAL ROCKIES AND THE 4 CORNERS. A SHORT WAVE
ROTATING WEST SOUTHWEST AC ROS THE SOUTHERN QUEBEC- ONTARIO BORDER
HAS ALREADY STARTED TO TURN TO THE SOUTH IN SATELLITE LOOPS AND
WILL CROSS OVER THEN CENTRAL AND EASTERN GREAT LAKES. MODELS
INDICATE A MID/UPPER SHORT WAVE DROPPING SOUTH OVER THE UPPER
MIDWEST LATE OVERNIGHT AND TUESDAY MORNING WITH A MODERATELY
STRONG VORT MAX CURRENTLY OVER SOUTHERN MN MOVING SOUTHEAST ACROSS
NORTHEAST IA TO CENTRAL IL BY MIDDAY. WHILE LOW LEVELS HAVE
MOISTURE TRAPPED BENEATH AN INVERSION UP AROUND 5K FT IT IS VERY
DRY IN THE MID AND UPPER LEVELS SO ANY UVV RESULTING FROM POSITIVE
VORTICITY ADVECTION ACROSS THE AREA WILL NOT HAVE MOISTURE TO WORK
WITH.
NORTHWEST WINDS WILL BE LESS THAN DURING THE DAY MONDAY AS THE
PRESSURE GRADIENT SLOWLY DECREASES OVER THE AREA AS THE HIGH
PRESSURE RIDGE TO THE WEST GRADUALLY APPROACHES THE AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE ALL FORECAST ELEMENTS.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...MVFR IMPROVING TO VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF RAIN/MVFR.
BMD
&&
.MARINE...
225 PM CDT
STRONG LOW PRESSURE OFF THE MID ATLANTIC COAST WILL MOVE EAST OUT
INTO THE ATLANTIC OCEAN WITH HIGH PRESSURE OVER THE PLAINS BUILDING
EAST INTO THE MISSISSIPPI VALLEY AND WESTERN GREAT LAKES. STRONG
NORTHERLY FETCH WILL KEEP WAVES UP FOR THE NEARSHORE THROUGH TUESDAY
OR TUESDAY NIGHT. FAIRLY LIGHT WINDS ARE EXPECTED WEDNESDAY THROUGH
FRIDAY AS HIGH PRESSURE SETS UP CAMP OVER THE REGION BEFORE SCOOTING
EAST OVER THE WEEKEND ALLOWING FOR SOUTHERLY WINDS TO DEVELOP.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 7 PM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
410 PM EDT TUE MAR 26 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 324 PM EDT TUE MAR 26 2013
SCATTERED FLURRIES AND ISOLATED SNOW SHOWERS SHOULD GIVE
WAY TO DRY CONDITIONS LATER TONIGHT AS AN UPPER RIDGE OF HIGH
PRESSURE MOVES INTO CENTRAL INDIANA. CLOUDS MAY LINGER A BIT LONGER
INTO WEDNESDAY MORNING BUT THEN SHOULD SEE SLOWLY INCREASING
TEMPERATURES AND DECREASING SKY COVER THROUGH THE REMAINDER OF THE
WORK WEEK. SATURDAY NIGHT CHANCES FOR RAIN ARRIVE AS LOW PRESSURE
MOVES THROUGH THE AREA BY SUNDAY NIGHT. TEMPERATURES MAX OUT IN THE
MIDDLE 50S ON SUNDAY BUT THEN DROP AGAIN FOR NEXT WEEK.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 324 PM EDT TUE MAR 26 2013
RADAR SHOWS SCATTERED WEAK ECHOES ACROSS CENTRAL INDIANA. MOST OF
THESE ARE PRODUCING ONLY FLURRIES...BUT THERE IS A WEAK WAVE MOVING
THROUGH AND SATELLITE IS SHOWING CONVECTIVE ENHANCEMENT TO THE
CLOUDS. WITH THIS IN MIND WILL GO WITH A 20 POP FOR THE REMAINDER OF
THE AFTERNOON FOR MUCH OF THE AREA AND MENTION ISOLATED SNOW SHOWERS
WITH SCATTERED FLURRIES. FOR TONIGHT HELD ONTO SLIGHT CHANCE POPS IN
THE NORTHEAST WITH FLURRIES ELSEWHERE THROUGH 6Z TO COVER LIGHT
ECHOES SHOWING UP IN HRRR DUE TO THE AFOREMENTIONED WEAK WAVE. AFTER
6Z WEATHER SHOULD BE DRY AS HIGH PRESSURE AND UPPER RIDGING START TO
BUILD IN.
INCREASED SKY COVER FROM CONSENSUS TO ACCOUNT FOR THE CYCLONIC
FLOW...LEAVING MOSTLY CLOUDY SKIES IN PLACE FOR MOST OF THE NIGHT.
THIS SHOULD KEEP TEMPERATURES FROM BOTTOMING OUT AND THUS A GUIDANCE
BLEND FOR LOW TEMPERATURES IN THE MIDDLE 20S LOOKED GOOD.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 324 PM EDT TUE MAR 26 2013
THE SHORT TERM LOOKS LIKE QUIET WEATHER IS IN STORE AS HIGH PRESSURE
BUILDS OVER THE AREA AND TEMPERATURES SLOWLY BEGIN TO WARM. SHOULD
SEE SKY COVER CLEARING DURING THE DAY ON WEDNESDAY AND LEAVE MOSTLY
CLEAR SKIES IN PLACE FOR WEDNESDAY NIGHT. WHILE THE MAV REBOUNDS
TEMPERATURES QUICKLY THINK THIS WILL BE TEMPERED BY SNOW COVER AND
THUS WENT NEAR RAW MODEL NUMBERS OF THE COOLER NAM. WENT WITH COOLER
CONSENSUS NUMBERS WHICH WERE COOLER THAN EITHER GUIDANCE FOR
WEDNESDAY NIGHT WITH THE MOSTLY CLEAR SKY COVER AND STILL SOME SNOW
PACK ESPECIALLY IN THE NORTH. AS FAR AS WARMING IS CONCERNED...BY
FRIDAY SHOULD SEE HIGHS IN THE UPPER 40S TO LOWER 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 245 PM EDT TUE MAR 26 2013
NICE WARMUP IN TEMPS FROM RECENT LEVELS CULMINATES OVER THE
WEEKEND AS MUCH OF THE FORECAST AREA LIKELY TO WARM IN THE 50S.
SATURDAY IN PARTICULAR WILL BE A NICE DAY WITH DRY CONDITIONS AS
HIGH PRESSURE SHIFTS OFF TO THE EAST. MODEL CONSENSUS REMAINS
CONSISTENT WITH TRACKING A COLD FRONT THROUGH THE REGION FOR THE
SECOND HALF OF THE WEEKEND...WITH RAIN LIKELY FROM LATE SATURDAY
THROUGH SUNDAY. IN THE WAKE OF THE FRONT TEMPERATURES WILL ONCE
AGAIN TURN COLDER TO BEGIN THE MONTH OF APRIL AS MODEL GUIDANCE
INDICATING THE POLAR VORTEX DIVING SOUTH INTO THE GREAT LAKES ONCE
AGAIN. THIS WILL ONCE AGAIN REESTABLISH A NORTHWEST FLOW ALOFT AS
THE POLAR VORTEX MOVES INTO NEW ENGLAND BY THE END OF THE PERIOD.
UNDERCUT ALLBLEND TEMPS FOR MONDAY AND TUESDAY AS THE SHOT OF
COLDER AIR IN THE WAKE OF THE PASSAGE OF THE FRONT LIKELY KEEPS
HIGHS IN THE 40S BOTH DAYS.
&&
.AVIATION /DISCUSSION FOR THE 26/21Z TAF UPDATE/...
ISSUED AT 410 PM EDT TUE MAR 26 2013
NO SIGNIFICANT CHANGES NECESSARY. PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 100 PM EDT TUE MAR 26 2013
BRIEF PERIODS OF MVFR CONDITIONS POSSIBLE THIS AFTERNOON WITHIN
LIGHT SNOW SHOWERS...OTHERWISE VFR EXPECTED THROUGH THE PERIOD.
WEAK RIDGING ALOFT PASSING THROUGH THE OHIO VALLEY EARLY THIS
AFTERNOON...ALLOWING FOR SOME BREAKS IN THE CLOUDS TO DEVELOP.
HAVE SEEN A GRADUAL INCREASE IN COVERAGE TO FLURRIES AND EVEN A
FEW SNOW SHOWERS OVER NORTHERN INDIANA...INFLUENCED BY NORTHWEST
FLOW IN THE LOW LEVELS COMING OFF OF LAKE MICHIGAN...AND THE
APPROACH OF ANOTHER WAVE ALOFT. BOTH OF THESE FEATURES COMBINED
WITH A PERIOD OF STEEPENING LAPSE RATES AND SUBTLE INSTABILITY IS
LIKELY TO CONTRIBUTE SCATTERED FLURRIES/SNOW SHOWERS THROUGH THE
AFTERNOON. WITH UNCERTAINTY TO COVERAGE AT THIS POINT...WILL JUST
CARRY A VCSH MENTION INTO THE EARLY EVENING AT ALL BUT KHUF.
NORTHWEST WINDS AT 10-15KTS WILL CONTINUE.
THE UPPER WAVE WILL MOVE TO THE SOUTHEAST OF THE TERMINALS THIS
EVENING WITH ANY LINGERING FLURRIES ENDING. WHILE IT DOES APPEAR
CLOUDS WILL SCATTER SOMEWHAT LATE TONIGHT AS HIGH PRESSURE NOSES
IN...REGION REMAINS IN A LARGELY CYCLONIC FLOW ALOFT AND WILL KEEP
CLOUDS AROUND INTO WEDNESDAY. W/NW WINDS WILL LIGHTEN UNDER 10KTS
OVERNIGHT AND SHOULD STAY THAT WAY INTO WEDNESDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...RYAN/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
326 PM EDT TUE MAR 26 2013
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 324 PM EDT TUE MAR 26 2013
SCATTERED FLURRIES AND ISOLATED SNOW SHOWERS SHOULD GIVE
WAY TO DRY CONDITIONS LATER TONIGHT AS AN UPPER RIDGE OF HIGH
PRESSURE MOVES INTO CENTRAL INDIANA. CLOUDS MAY LINGER A BIT LONGER
INTO WEDNESDAY MORNING BUT THEN SHOULD SEE SLOWLY INCREASING
TEMPERATURES AND DECREASING SKY COVER THROUGH THE REMAINDER OF THE
WORK WEEK. SATURDAY NIGHT CHANCES FOR RAIN ARRIVE AS LOW PRESSURE
MOVES THROUGH THE AREA BY SUNDAY NIGHT. TEMPERATURES MAX OUT IN THE
MIDDLE 50S ON SUNDAY BUT THEN DROP AGAIN FOR NEXT WEEK.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 324 PM EDT TUE MAR 26 2013
RADAR SHOWS SCATTERED WEAK ECHOES ACROSS CENTRAL INDIANA. MOST OF
THESE ARE PRODUCING ONLY FLURRIES...BUT THERE IS A WEAK WAVE MOVING
THROUGH AND SATELLITE IS SHOWING CONVECTIVE ENHANCEMENT TO THE
CLOUDS. WITH THIS IN MIND WILL GO WITH A 20 POP FOR THE REMAINDER OF
THE AFTERNOON FOR MUCH OF THE AREA AND MENTION ISOLATED SNOW SHOWERS
WITH SCATTERED FLURRIES. FOR TONIGHT HELD ONTO SLIGHT CHANCE POPS IN
THE NORTHEAST WITH FLURRIES ELSEWHERE THROUGH 6Z TO COVER LIGHT
ECHOES SHOWING UP IN HRRR DUE TO THE AFOREMENTIONED WEAK WAVE. AFTER
6Z WEATHER SHOULD BE DRY AS HIGH PRESSURE AND UPPER RIDGING START TO
BUILD IN.
INCREASED SKY COVER FROM CONSENSUS TO ACCOUNT FOR THE CYCLONIC
FLOW...LEAVING MOSTLY CLOUDY SKIES IN PLACE FOR MOST OF THE NIGHT.
THIS SHOULD KEEP TEMPERATURES FROM BOTTOMING OUT AND THUS A GUIDANCE
BLEND FOR LOW TEMPERATURES IN THE MIDDLE 20S LOOKED GOOD.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 324 PM EDT TUE MAR 26 2013
THE SHORT TERM LOOKS LIKE QUIET WEATHER IS IN STORE AS HIGH PRESSURE
BUILDS OVER THE AREA AND TEMPERATURES SLOWLY BEGIN TO WARM. SHOULD
SEE SKY COVER CLEARING DURING THE DAY ON WEDNESDAY AND LEAVE MOSTLY
CLEAR SKIES IN PLACE FOR WEDNESDAY NIGHT. WHILE THE MAV REBOUNDS
TEMPERATURES QUICKLY THINK THIS WILL BE TEMPERED BY SNOW COVER AND
THUS WENT NEAR RAW MODEL NUMBERS OF THE COOLER NAM. WENT WITH COOLER
CONSENSUS NUMBERS WHICH WERE COOLER THAN EITHER GUIDANCE FOR
WEDNESDAY NIGHT WITH THE MOSTLY CLEAR SKY COVER AND STILL SOME SNOW
PACK ESPECIALLY IN THE NORTH. AS FAR AS WARMING IS CONCERNED...BY
FRIDAY SHOULD SEE HIGHS IN THE UPPER 40S TO LOWER 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 245 PM EDT TUE MAR 26 2013
NICE WARMUP IN TEMPS FROM RECENT LEVELS CULMINATES OVER THE
WEEKEND AS MUCH OF THE FORECAST AREA LIKELY TO WARM IN THE 50S.
SATURDAY IN PARTICULAR WILL BE A NICE DAY WITH DRY CONDITIONS AS
HIGH PRESSURE SHIFTS OFF TO THE EAST. MODEL CONSENSUS REMAINS
CONSISTENT WITH TRACKING A COLD FRONT THROUGH THE REGION FOR THE
SECOND HALF OF THE WEEKEND...WITH RAIN LIKELY FROM LATE SATURDAY
THROUGH SUNDAY. IN THE WAKE OF THE FRONT TEMPERATURES WILL ONCE
AGAIN TURN COLDER TO BEGIN THE MONTH OF APRIL AS MODEL GUIDANCE
INDICATING THE POLAR VORTEX DIVING SOUTH INTO THE GREAT LAKES ONCE
AGAIN. THIS WILL ONCE AGAIN REESTABLISH A NORTHWEST FLOW ALOFT AS
THE POLAR VORTEX MOVES INTO NEW ENGLAND BY THE END OF THE PERIOD.
UNDERCUT ALLBLEND TEMPS FOR MONDAY AND TUESDAY AS THE SHOT OF
COLDER AIR IN THE WAKE OF THE PASSAGE OF THE FRONT LIKELY KEEPS
HIGHS IN THE 40S BOTH DAYS.
&&
.AVIATION /DISCUSSION FOR 261800Z TAF ISSUANCE/...
ISSUED AT 100 PM EDT TUE MAR 26 2013
BRIEF PERIODS OF MVFR CONDITIONS POSSIBLE THIS AFTERNOON WITHIN
LIGHT SNOW SHOWERS...OTHERWISE VFR EXPECTED THROUGH THE PERIOD.
WEAK RIDGING ALOFT PASSING THROUGH THE OHIO VALLEY EARLY THIS
AFTERNOON...ALLOWING FOR SOME BREAKS IN THE CLOUDS TO DEVELOP.
HAVE SEEN A GRADUAL INCREASE IN COVERAGE TO FLURRIES AND EVEN A
FEW SNOW SHOWERS OVER NORTHERN INDIANA...INFLUENCED BY NORTHWEST
FLOW IN THE LOW LEVELS COMING OFF OF LAKE MICHIGAN...AND THE
APPROACH OF ANOTHER WAVE ALOFT. BOTH OF THESE FEATURES COMBINED
WITH A PERIOD OF STEEPENING LAPSE RATES AND SUBTLE INSTABILITY IS
LIKELY TO CONTRIBUTE SCATTERED FLURRIES/SNOW SHOWERS THROUGH THE
AFTERNOON. WITH UNCERTAINTY TO COVERAGE AT THIS POINT...WILL JUST
CARRY A VCSH MENTION INTO THE EARLY EVENING AT ALL BUT KHUF.
NORTHWEST WINDS AT 10-15KTS WILL CONTINUE.
THE UPPER WAVE WILL MOVE TO THE SOUTHEAST OF THE TERMINALS THIS
EVENING WITH ANY LINGERING FLURRIES ENDING. WHILE IT DOES APPEAR
CLOUDS WILL SCATTER SOMEWHAT LATE TONIGHT AS HIGH PRESSURE NOSES
IN...REGION REMAINS IN A LARGELY CYCLONIC FLOW ALOFT AND WILL KEEP
CLOUDS AROUND INTO WEDNESDAY. W/NW WINDS WILL LIGHTEN UNDER 10KTS
OVERNIGHT AND SHOULD STAY THAT WAY INTO WEDNESDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1154 AM MDT TUE MAR 26 2013
.UPDATE...
ISSUED AT 1143 AM MDT TUE MAR 26 2013
COMPLETED AN UPDATE EARLIER. SWITCH IN WIND DIRECTION FROM
YESTERDAY HAS MADE A BIG DIFFERENCE. WITH THE SOUTH WINDS THE
SOUTHEAST FRINGE OF THE AREA THAT HAS LITTLE TO NO SNOW IS WARMING
UP QUICKLY. THE MESOSCALE MODELS ARE CATCHING THIS. HOWEVER...THEY...WITH
THE EXCEPTION OF THE NAM12...ARE EXTENDING THIS WARMING WELL INTO
THE DEEPER SNOWFIELD. NAM IS KEEPING THE MAIN WARMING CONFINED TO
OUR EXTREME SOUTH WHICH IS NOT FAR ENOUGH NORTH IN COMPARISON TO
THE CURRENT OBSERVATIONS.
CONSIDERING THE POSITION AND DEEPENING NATURE OF THE SURFACE LOW
OVER SOUTHEAST COLORADO...BELIEVE AT THIS TIME THAT THE FURTHER
NORTH SOLUTIONS ARE TOO FAR NORTH. SO WILL USE THE MESOSCALE
MODELS TO WARM THIS SOUTHEAST FRINGE AND TEMPER THE WARMING
FURTHER NORTH. VERY LOW CONFIDENCE IN HOW THIS IS GOING TO WORK
OUT. THE HRRR AND NAM ARE CATCHING THE WIND FIELD THE BEST AND
ADJUSTED ACCORDING TO THEM.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 231 AM MDT TUE MAR 26 2013
MAIN FORECAST CONCERN IN THE SHORT TERM PERIOD IS ON TEMPERATURES.
TEMPERATURES WILL WARM THROUGH THE WEEK WITH WEAK RIDGING ALOFT
OVER THE ROCKY MOUNTAIN AND INTERMOUNTAIN WEST AND GENERALLY SOUTH
WINDS AT THE SURFACE OVER THE CENTRAL HIGH PLAINS REGION.
THE COLD HIGH PRESSURE AREA IN PLACE OVER THE REGION WILL MOVE TO
THE EAST TODAY. WINDS BECOME MORE SOUTHERLY AHEAD OF A WEAK
SURFACE TROUGH THAT DEVELOPS ALONG THE FRONT RANGE FROM WYOMING TO
NEW MEXICO IN RESPONSE TO A COUPLE OF SHORT WAVE TROUGHS MOVING
THROUGH APEX OF THE UPPER RIDGE AND EAST OF THE ROCKIES TONIGHT
AND ACROSS THE FORECAST AREA BY MID DAY ON WEDNESDAY. CLOUDS WILL
INCREASE WITH FLURRIES POSSIBLE OVERNIGHT AS THE TROUGH MOVES
ACROSS THE FORECAST AREA.
THE RIDGE REAMPLIFIES WEDNESDAY NIGHT THROUGH THURSDAY NIGHT WITH
DRY CONDITIONS AND TEMPERATURES THAT WILL CONTINUE TO WARM.
SNOWCOVER IS EXPECTED TO SUPPRESS DAYTIME WARMING AND HAVE KEPT
MAINLY THE NORTHWEST PORTION OF THE FORECAST AREA COOLER DURING
THE DAY.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 102 AM MDT TUE MAR 26 2013
MODELS SHOW A RATHER UNSETTLED LONG TERM PERIOD. THE CENTRAL
PLAINS WILL BE UNDER NORTHWEST FLOW ALOFT TO START THE
PERIOD...FOLLOWED BY BRIEF SHORTWAVE RIDGING AROUND SUNDAY AHEAD
OF A SOUTHERN STREAM DISTURBANCE WHICH WILL APPROACH EARLY NEXT
WEEK. WHILE UNDER NORTHWEST FLOW...A SERIES OF WEAK SHORTWAVE
TROUGHS WILL PROVIDE WEAK FORCING FOR SLIGHT/LOW CHANCES OF
SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM WITH WEAK SURFACE
BASED INSTABILITY FORECAST FRIDAY AND SATURDAY AFTERNOON/EVENINGS.
DRY WEATHER WILL ACCOMPANY THE RIDGE ON SUNDAY. HOWEVER...BEST
CHANCES FOR PRECIPITATION WILL BE WITH THE SYSTEM EARLY NEXT
WEEK. PRECIPITATION TYPE MAY BE PROBLEMATIC AS MODELS SHOW A
SHALLOW COLD AIR MASS ARRIVING ON MONDAY...WITH FREEZING/FROZEN
PRECIPITATION POSSIBLE. TEMPERATURES MAY BE MUCH COLDER THAN
CURRENTLY FORECAST IN THE MONDAY AND TUESDAY PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1143 AM MDT TUE MAR 26 2013
COMPLICATED SET OF TAFS. WINDS BEING AFFECTED BY THE SNOWFIELD.
IN ADVANCE OF A FAST MOVING SYSTEM...WINDS WILL SHIFT FROM SOUTH
TO NORTH DURING THE NIGHT. MOISTURE AHEAD OF THIS SYSTEM APPEARS
TO BE LACKING. HOWEVER...MODELS SHOWING A RATHER STRONG RIGHT REAR
QUADRANT OF THE JET AND STRONG PV ANOMALY...MAINLY TOWARD THE
SOUTH. SO AT THIS TIME...PUT IN FLURRIES AT KGLD WITHOUT ANY
RESTRICTIONS AND VFR CEILINGS. WITH A LIGHT EASTERLY WINDS
FIELD...THERE WILL BE THE POSSIBILITY OF FOG AT KMCK. CONDITIONS
IMPROVE BY 15Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...LOCKHART
LONG TERM...024
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
112 PM EDT TUE MAR 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 513 AM EDT TUE MAR 26 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A PERSISTENT BLOCKING RIDGE
FROM NRN CANADA INTO HUDSON BAY AND A TROUGH FROM THE CANADIAN
MARITIMES INTO NRN NEW ENGLAND RESULTING IN WEAK NE FLOW THROUGH THE
NRN GRREAT LAKES. AT THE SFC...NRLY FLOW PREVAILED ACROSS LAKE
SUPERIOR BETWEEN A TROUGH INTO THE ERN LAKES AND A RIDGE OVER THE
PLAINS. IR LOOP SHOWED THE BACK EDGE OF THE CLOUDS AND DEEPER
MOISTURE ADVANCING WESTWARD TOWARD THE E SIDE OF LAKE SUPERIOR.
RADAR INDICATED SCT SHSN INTO CNTRL UPPER MI WITH MORE CELLULAR THAN
BANDED PATTERN MORE TYPICAL OF LES. EVEN THOUGH 850 MB TEMPS TO NEAR
-10C ONLY PROVIDED MARGINAL OVER LAKE INSTABILITY...A WEAK SHORTWAVE
TROUGH AND ASSOCIATED 700-300 MB QVECTOR CONV HAS SUPPORTED SHSN
DEVELOPMENT. SNOW/WATER RATIO HAS INCREASED AND -FZDZ POTENTIAL
DIMINISHED WITH MOISTURE THROUGH THE DGZ.
TODAY...AS THE FORCING WITH THE SHRTWV SLIDES OFF TO THE SOUTHEAST
AND THE DEEPER MOISTURE DEPARTS...EXPECT THE SHSN TO QUICKLY
DIMINISH BY LATE MORNING. SO...ADDITIONAL SNOWFALL AMOUNTS OF ONLY A
HALF INCH OR LESS ARE EXPECTED. THERE MAY STILL BE A PERIOD WHERE
SOME -FZDZ IS POSSIBLE AS THE MOIST LAYER FALLS AT OR BELOW THE -10C
LEVEL. WITH DAYTIME HEATING AND GREATER MIXING...THERE MAY EVEN BE A
PERIOD OF SOME CLEARING INTO THE E HALF OF UPPER MI.
OTHERWISE...HIGH TEMPS WILL REMAIN BELOW NORMAL...IN THE LOWER TO
MID 30S.
TONIGHT...ANOTHER BATCH OF 925-850 MB MOISTURE IS EXPECTED TO MOVE
IN FROM THE NORTHEAST BRINGING THE POTENTIAL FOR ANOTHER ROUND OF
LAKE ENHANCED PCPN. SINCE TEMPS NEAR TO THE TOP OF THE MOIST LAYER
AT 850 MB ARE A BIT HIGHER...ONLY TO AROUND -8C...THERE MAY BE A
BETTER CHANCE FOR -FZDZ WITH ANY PCPN THAT DEVELOPS. WITH ONLY A
MODEST NRLY UPSLOPE WIND COMPONENT IN THE 20 TO 25 KNOT RANGE...ONLY
SLIGHT OR LOWER END CHANCE POPS WERE MENTIONED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM EDT TUE MAR 26 2013
LINGERING LOW LEVEL MOISTURE ROTATING IN FROM THE NORTH WILL BE
SLOWLY DIMINISHING WITH MUCH OF THE REMAINING FREEZING DRIZZLE AND
LIGHT SNOW SHOWERS/FLURRIES ENDING FOR THE MOST PART ON WEDNESDAY.
MOISTURE WILL BE TRAPPED BELOW 800MB WEDNESDAY MORNING AND FALL
AROUND OR BELOW 900MB BY WEDNESDAY EVENING...UNDER THE STRENGTHENING
INVERSION. WHILE THE MODELS DO SPIT OUT AROUND 0.01IN OR LESS
WEDNESDAY NIGHT AND THURSDAY...SIGNIFICANT PRECIP IS NOT ANTICIPATED.
THE STEADILY WARMING AFTERNOON HIGH TEMPERATURES WILL CONTINUE AS
THE 500MB HIGH OVER HUDSON BAY ON TUESDAY SINKS INTO ONTARIO AND
COMBINES WITH THE RIDGE ALREADY SET UP ACROSS THE WESTERN HALF OF
THE UNITED STATES. 850MB TEMPS AROUND -11C WEDNESDAY MORNING WILL
WARM TO -6C BY 12Z THURSDAY ON CONTINUED NORTHERLY WINDS...AND
REMAIN NEARLY STEADY THROUGH FRIDAY AFTERNOON.
A WEAK SHORTWAVE WILL SWING IN ON THE NORTHWESTERLY FLOW ALOFT
THURSDAY NIGHT INTO EARLY FRIDAY...WITH LITTLE INFLUENCE ON OUR
WEATHER. THE WRAPPED UP 500MB LOW ENCOMPASSING MUCH OF CENTRAL
CANADA FROM MID WEEK ON WILL DIG A TROUGH ACROSS THE NORTHERN PLAINS
FRIDAY NIGHT INTO SATURDAY...AND EXTEND TO THE UPPER GREAT LAKES
FROM SATURDAY THROUGH AT LEAST MONDAY. TIMING AND STRENGTH OF THE
ASSOCIATED COLD FRONT IS STILL IN QUESTION...BUT IT LOOKS LIKE IT
SHOULD BE OVER FAR WESTERN LAKE SUPERIOR SATURDAY AFTERNOON...AND
SLOWLY TRANSITION ACROSS CENTRAL AND EASTERN LAKE SUPERIOR SATURDAY
NIGHT...AS THE SFC LOW DRIFTS OVER CENTRAL ONTARIO.
WHILE THE GFS IS MORE PROGRESSIVE WITH THE FRONT...AND BUILDS COLD
HIGH PRESSURE BACK INTO WESTERN AND CENTRAL LAKE SUPERIOR ON
SUNDAY...THE ECMWF HOLDS ONTO THE SFC TROUGH A BIT LONGER. THE
DIFFERENCE SHOWS UP WELL ON THE 850MB CHART...WITH TEMPS OF -14C AT
18Z SUNDAY OFF THE GFS...WHILE THE ECMWF STILL HAS READINGS AROUND
-4C...AND KEEPS ANY COOLER READINGS BELOW -10C TO LATE SUNDAY NIGHT
AND BEYOND. THE 500MB TROUGH SHOULD PUSH EAST INTO THE LOWER GREAT
LAKES AND EASTERN ONTARIO ON MONDAY...WITH NORTHWESTERLY FLOW
REMAINING ALOFT THROUGH AT LEAST TUESDAY. ON A SIDE NOTE...THE
00Z/26 RUN OF THE ECMWF SIGNIFICANTLY INTENSIFIED THE SOUTHERN EDGE
OF THE TROUGH ROTTING THROUGH THE AREA SUNDAY NIGHT. THIS WOULD
RESULT IN A BETTER CHANCE OF PRECIPITATION...AND MUCH STRONGER
WINDS. AT 12Z MONDAY THE 12Z/25 RUN HAD WINDS OF UP TO 25KTS AT
850MB. THE LATEST RUN...WITH A SECONDARY DEEPENING SFC LOW CROSSING
CENTRAL AND EASTERN UPPER MICHIGAN SUNDAY NIGHT ALLOWS FOR A 45-60KT
850MB LLJ TO CROSS AT 12Z MONDAY. WILL BE INTERESTING IF THE 12Z RUN
LATER TODAY KEEPS UP THIS TREND...BUT FOR NOW WILL KEEP IT OUT OF
THE ONGOING FORECAST...WITH NO GALES OVER THE LAKE EXPECTED QUITE
YET.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 111 PM EDT TUE MAR 26 2013
VFR CONDITIONS WILL CONTINUE PREVAIL AT ALL SITES THIS AFTERNOON.
UNTIL THE DRIER AIR GETS IN AT SAW...MVFR CIGS WILL BE IN EARLY THIS
AFTERNOON. WITH THE LOSS OF DAYTIME HEATING/MIXING AND WITH
ADDITIONAL LOW LEVEL MOISTURE MOVING IN FROM THE NORTHEAST AND WEAK
UPSLOPE FLOW...MVFR CIGS ARE EXPECTED AGAIN TONIGHT INTO WED
MORNING. THERE COULD ALSO BE SOME UPSLOPE FLURRIES AND FREEZING
DRIZZLE AT IWD AND SAW OVERNIGHT TONIGHT INTO WED MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 513 AM EDT TUE MAR 26 2013
HIGH PRESSURE OVER THE PLAINS WILL ONLY SLOWLY BUILD TO THE EAST
TODAY INTO WEDNESDAY KEEPING NORTHERLY WINDS IN THE 15 TO 25 KNOT
RANGE OVER THE EAST HALF OF THE LAKE AND IN THE 10 TO 15 KNOT RANGE
OVER THE WEST. AS THE HIGH BUILDS INTO THE WESTERN GREAT LAKES FROM
WED NIGHT INTO FRIDAY WINDS WILL BE RELATIVELY LIGHT...GENERALLY
BELOW 20 KNOTS. AS THE RIDGE SHIFTS TO THE EAST OF THE AREA
SATURDAY...LIGHT TO MODERATE S TO SW WINDS WILL DEVELOP.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1250 PM EDT TUE MAR 26 2013
.AVIATION...
//DISCUSSION...
THE RADAR AND SATELLITE COMPOSITE HAS BEEN SHOWING CONVECTIVE
INSTABILITY ON THE INCREASE. EXPECT THE COVERAGE OF RAIN SHOWERS
WILL INCREASE THROUGH THE AFTERNOON AS A RESULT. SOME OF THE HIGHER
INTENSITY SHOWERS WILL BE CAPABLE OF PRODUCING A BRIEF BURST OF
SNOW. WHILE RESIDUAL LOW LEVEL MOISTURE THIS MORNING LED TO SOME
POCKETS OF MVFR STRATO CU...CLOUD BASES WILL SLOWLY RISE THROUGH THE
AFTERNOON WITH CONTINUED DAYTIME HEATING. CLOUDS WILL DECREASE IN
COVERAGE DURING THE EVENING AS DAYTIME INSTABILITY IS LOST.
OBSERVATIONAL DATA ACROSS ONTARIO /NORTHEAST OF LAKE HURON/ SUGGEST
CONDITIONS ARE MUCH DRIER THAN CURRENT MODEL SOLUTIONS INDICATE.
THIS SUPPORTS HOLDING ANY CEILING ABOVE 6K FT THIS EVENING THROUGH
DAYBREAK WED.
FOR DTW...OCCASIONAL CLOUD BASES BETWEEN 3K AND 5K FT CAN BE
EXPECTED THIS AFTERNOON...ESPECIALLY DURING ANY CONVECTIVE SHOWERS.
THE DEGREE OF DRY AIR NOW OBSERVED UPSTREAM IS SUGGESTIVE OF A GOOD
CHANCE THAT CIGS WILL REMAIN CLEAR BELOW 5K FT TONIGHT INTO EARLY
WED MORNING.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILING BELOW 5000 FEET THIS AFTERNOON AND
EVENING.
&&
.PREV DISCUSSION...ISSUED 1017 AM EDT TUE MAR 26 2013
UPDATE...
THE 12Z DTX SOUNDING SHOWED RATHER STEEP LAPSE RATES IN THE
900-700MB LAYER. BY AFTERNOON...DIURNAL HEATING WILL ONLY STEEPEN
THE LOW LEVEL LAPSE RATES. THE REGIONAL WATER VAPOR LOOP SHOWS A
WEAK MID LEVEL CIRCULATION OVER THE WESTERN GREAT LAKES. THIS
FEATURE WILL SPREAD SOME LARGE SCALE ASCENT ACROSS SE MI THROUGH
EARLY AFTERNOON. THE COMBINATION OF THE WEAK LARCE SCALE LIFT AND
INCREASING DIURNAL INSTABILITY WITHIN A REGION OF AMPLE MID LEVEL
MOISTURE OVER LOWER MI SHOULD SUPPORT FAIRLY GOOD COVERAGE OF
SHOWERS ACROSS A GOOD PORTION OF THE FORECAST AREA THIS AFTERNOON.
THIS WILL BE SUPPORTIVE OF A SLIGHT INCREASE IN POPS THIS
AFTERNOON. THE MORNING DTX SOUNDING ALSO SUGGESTED THAT AFTERNOON
MIXING WILL BOOST TEMPS INTO THE LOWER 40S. THIS LOOKS REASONABLE
GIVEN THERE HAVE BEEN SOME BREAKS IN THE CLOUDS AND GIVEN 10 AM
TEMPS ARE ALREADY IN THE MID-UPPER 30S. THIS SLIGHT UPWARD
ADJUSTMENT TO THE TEMPS /WHICH THE RAP SOUNDINGS SEEM TO HAVE A
BETTER HANDLE ON/ WOULD SUGGEST THAT THE DEPTH OF WARM AIR IN THE
BOUNDARY LAYER WOULD BE SUPPORTIVE OF MAINLY RAIN FOR AFTERNOON
PRECIP TYPE. GIVEN THE CONVECTIVE POTENTIAL...A CHANGE OVER TO
BRIEFLY HEAVY/WET SNOW WOULD STILL BE POSSIBLE. THUS WILL UPDATE
THE FORECAST TO INCREASE AFTERNOON TEMPS AND ADD A MIX OF
RAIN/SNOW TO THE PRECIP TYPE.
PREV DISCUSSION...ISSUED 331 AM EDT TUE MAR 26 2013
SHORT TERM... TODAY AND TONIGHT
RADAR COMPOSITES INDICATE RESPECTABLE COVERAGE OF FLURRIES AND
CLUSTERS OF SNOW SHOWERS OVER LOWER MICHIGAN DURING THE EARLY
MORNING. THE 00Z SOUNDINGS FROM APX AND DTX INDICATE THIS LIGHT
ACTIVITY IS PRIMARILY A RESULT OF BROAD CYCLONIC LOW LEVEL FLOW
WORKING ON STEEP LAPSE RATES OF 7-8 C/KM BELOW 750 MB. CLUSTERS OF
SNOW SHOWERS SLIGHTLY ABOVE A FLURRY EMANATING FROM OVER LAKE HURON
ARE GETTING A BOOST FROM THE RELATIVELY WARM WATER BUT ARE JUST AN
EXTENSION OF ACTIVITY FROM UPSTREAM OVER NORTHERN ONTARIO RATHER
THAN LEGITIMATE LAKE EFFECT. SATELLITE IMAGERY ALSO INDICATES MID
LEVEL CIRCULATION WITHIN THE WEAK UPPER LEVEL TROUGH OVER THE
NORTHERN GREAT LAKES. THIS FEATURE WILL ADD SOME MID LEVEL COOLING
TO THE RATHER SUBSIDENT LOOKING 00Z APX SOUNDING AS THE TROUGH
SETTLES SOUTHWARD OVER LOWER MICHIGAN DURING THE DAY. ADD TO THAT A
COMPONENT OF DIURNAL SURFACE WARMING AND WE CAN EXPECT ONGOING
ACTIVITY TO CONTINUE IF NOT GROW IN COVERAGE BY LATE MORNING THROUGH
THE AFTERNOON. MODEL SOUNDINGS INDICATE THE ABOVE FREEZING LAYER
DEEPENING FROM THE SURFACE TO JUST ABOUT 800 FEET BY MID AFTERNOON
WHICH IS SHALLOW ENOUGH TO ALLOW SNOWFLAKES TO REACH THE SURFACE
WHERE THEY WILL MELT ON CONTACT WITH THE GROUND AS MAX TEMPS MAKE A
RUN TOWARD 40. GIVEN THE EXPECTATION OF ONLY TRACE AMOUNTS OF SNOW
AT ANY ONE LOCATION, THE INHERITED GENEROUS SCATTERED POP FORECAST
LOOKS FINE AND WILL BE CONTINUED IN THIS PACKAGE.
LEFTOVER DIURNALLY ENHANCED SNOW SHOWERS OR FLURRIES WILL LAST INTO
THE EVENING BUT WILL THEN GIVE WAY TO A CHALLENGING CLOUD FORECAST
FOR THE REST OF THE NIGHT. A SIZEABLE SLUG OF DRY AIR OVER WESTERN
QUEBEC/NE ONTARIO AT PRESS TIME WILL LIKELY HAVE A NEGATIVE
INFLUENCE ON THE POTENTIAL FOR STRATOCU MAINTENANCE OVER THE GREAT
LAKES LATER TONIGHT. THIS DRY AIR WILL WORK AGAINST CONTINUED BROAD
CYCLONIC FLOW THROUGH THE LOW LEVELS WITH ENOUGH COLD AIR BELOW 850
MB FOR SOME SIPHONING OF MOISTURE FROM THE LAKES. LOW LEVEL RH
FIELDS IN THE 00Z MODELS EXHIBIT THE USUAL HIGH BIAS IN MOISTURE
CONTENT WHICH MAKES IT A TOUGH CALL ON WHICH PROCESS WILL WIN OUT.
THE FORECAST WILL REFLECT CAUTIOUS OPTIMISM BY CUTTING CLOUD COVER
BELOW MODEL DEPICTIONS BUT STILL MAINTAIN SOME COVERAGE THROUGH
SUNRISE WEDNESDAY.
LONG TERM...WEDNESDAY THROUGH MONDAY
PV ANOMALY ASSOCIATED WITH THE NEWFOUNDLAND UPPER LOW IS STILL
PROGGED BY THE 00Z GUIDANCE TO ROTATE SOUTHWARD ACROSS THE EASTERN
GREAT LAKES LATE ON WEDNESDAY, BRINGING A GLANCING BLOW OF SHALLOW
FORCING FOR ASCENT TO SOUTHEAST MICHIGAN. ULTIMATELY MADE THE
DECISION TO REINTRODUCE POPS FOR LATE WEDNESDAY NIGHT OWING
PRIMARILY TO THE RESPECTABLE MOISTURE CONTENT THAT WILL BE
ASSOCIATED WITH THIS WAVE. 00Z NAM PLANVIEWS DEPICT OF 2 G/KG OF H20
AT H7 AND 3 G/KG AT H85. WHILE NOT PARTICULARLY IMPRESSIVE, THIS
WILL BE SUFFICIENT TO MAINTAIN SATURATION THROUGH ABOUT THE LOWEST
10KFT AND WILL ALSO PROVIDE A BRIEF WINDOW FOR ACTIVATION OF THE
DENDRITE GROWTH LAYER...AT LEAST THE LOWER REACHES OF IT. AS A
RESULT, POPS TAPERING FROM HIGH CHANCE IN THE EASTERN THUMB TO LOW
CHC ACROSS THE CENTRAL/SW CWA ARE NOW IN PLACE ALONG WITH
CATEGORICAL MENTION OF FLURRIES FOR ROUGHLY THE SAME AREA.
A STRONG SURGE OF PACIFIC JET ENERGY WILL DRIVE THE EVOLUTION OF THE
LARGE SCALE NOAM PATTERN FOR THE REMAINDER OF THE LONG TERM PERIOD.
WHAT THIS WILL MEAN LOCALLY IS THAT THE NEXT TWO DAYS WILL BE
CHARACTERIZED BY DECREASING INFLUENCE OF LARGE SCALE MOIST CYCLONIC
FLOW AND THUS INCREASED POTENTIAL TO SEE SOME SUN AND WARMING OF
TEMPERATURES BEGINNING ACROSS THE WEST ON THURSDAY. AS THE UPPER AIR
PATTERN IS PUSHED ALONG BY THE PAC JET, HIGH LATITUDE SHORTWAVE
RIDGING WILL DEAMPLIFY AND PROPAGATE ACROSS THE GREAT LAKES
THURS/FRI RESULTING IN A PATTERN OF RISING HEIGHTS AND A REBOUNDING
THERMAL FIELD. AREAS THAT SEE SUN ON THURSDAY, MOST LIKELY ACROSS
THE FAR WEST/SOUTHWEST WILL SEE TEMPERATURES JUMP INTO THE MID 40S,
WHILE THE REMAINDER OF SEMI WILL HAVE TO WAIT UNTIL FRIDAY WHEN MOST
OF THE AREA WILL SEE MID/UPPER 40S. ANOTHER ROUND OF SHORTWAVE
RIDGING LEADING A RENEWED SURGE OF DRY NW FLOW WILL KEEP THE AREA
DRY THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND AND WILL FORCE
FURTHER WARMTH TO LIFT INTO THE STATE ALLOWING HIGHS TO CLIMB TO
AROUND 50.
THE APPROACH OF THE AFOREMENTIONED PAC JET SURGE WILL BE FELT
STRONGLY SUNDAY INTO MONDAY, FIRST WITH A PERIOD OF RAIN SHOWERS
ASSOCIATED WITH THE INITIAL ROUND OF HEIGHT FALLS ON SUNDAY AND THEN
WITH THE PASSAGE OF A VIGOROUS UPPER TROUGH AS THE JET DIVES OUT OF
NW FLOW ALOFT. MONDAY WILL THEN POTENTIALLY REPRESENT A TRANSITION
DAY THAT WILL SEE THE RETURN OF BELOW NORMAL TEMPERATURES/SNOW
CHANCES. SOLID RUN-TO-RUN CONTINUITY OF THE ECMWF ALONG WITH THE
HIGH AMPLITUDE NATURE OF THE TROUGH AND GRADUAL TREND TOWARD A MORE
VIGOROUS EVOLUTION ALL LEND HIGHER THAN NORMAL CONFIDENCE IN THE
GENERAL ASPECT OF A RETURN TO COOLER WEATHER EARLY NEXT WEEK.
MULTIPLE CYCLES OF THE GFS PROVIDING RESPECTABLE CONTINUITY LATE
THIS WEEKEND INTO EARLY NEXT WEEK PROVIDE AN ADDITIONAL BOOST IN
CONFIDENCE.
MARINE...
LAKE HURON AND LOWER MICHIGAN WILL REMAIN BETWEEN HIGH PRESSURE OVER
THE PLAINS AND LOW PRESSURE OFF THE NEW ENGLAND COAST THROUGH THE
MIDDLE PART OF THE WEEK. THIS WILL MAINTAIN A PERSISTENT NORTHWEST
WIND IN THE 10 TO 15 KNOT RANGE WITH GUSTS TO 20 KNOTS. THE WIND
FIELD WILL VARY IN STRENGTH DURING THIS TIME BUT OVERALL WILL FORCE
WAVES IN EXCESS OF 4 FEET OVER THE SOUTH HALF OF LAKE HURON AT LEAST
THROUGH WEDNESDAY NIGHT. HIGH PRESSURE WILL THEN BE ABLE TO MAKE
SOME EASTWARD PROGRESS INTO THE GREAT LAKES THURSDAY WHICH WILL HELP
IMPROVE MARINE CONDITIONS HEADING INTO THE WEEKEND.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
SANILAC...UNTIL 6 AM THURSDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...BT
LONG TERM....JVC
MARINE.......BT
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
1017 AM EDT TUE MAR 26 2013
.UPDATE...
THE 12Z DTX SOUNDING SHOWED RATHER STEEP LAPSE RATES IN THE
900-700MB LAYER. BY AFTERNOON...DIURNAL HEATING WILL ONLY STEEPEN
THE LOW LEVEL LAPSE RATES. THE REGIONAL WATER VAPOR LOOP SHOWS A
WEAK MID LEVEL CIRCULATION OVER THE WESTERN GREAT LAKES. THIS
FEATURE WILL SPREAD SOME LARGE SCALE ASCENT ACROSS SE MI THROUGH
EARLY AFTERNOON. THE COMBINATION OF THE WEAK LARCE SCALE LIFT AND
INCREASING DIURNAL INSTABILITY WITHIN A REGION OF AMPLE MID LEVEL
MOISTURE OVER LOWER MI SHOULD SUPPORT FAIRLY GOOD COVERAGE OF
SHOWERS ACROSS A GOOD PORTION OF THE FORECAST AREA THIS AFTERNOON.
THIS WILL BE SUPPORTIVE OF A SLIGHT INCREASE IN POPS THIS
AFTERNOON. THE MORNING DTX SOUNDING ALSO SUGGESTED THAT AFTERNOON
MIXING WILL BOOST TEMPS INTO THE LOWER 40S. THIS LOOKS REASONABLE
GIVEN THERE HAVE BEEN SOME BREAKS IN THE CLOUDS AND GIVEN 10 AM
TEMPS ARE ALREADY IN THE MID-UPPER 30S. THIS SLIGHT UPWARD
ADJUSTMENT TO THE TEMPS /WHICH THE RAP SOUNDINGS SEEM TO HAVE A
BETTER HANDLE ON/ WOULD SUGGEST THAT THE DEPTH OF WARM AIR IN THE
BOUNDARY LAYER WOULD BE SUPPORTIVE OF MAINLY RAIN FOR AFTERNOON
PRECIP TYPE. GIVEN THE CONVECTIVE POTENTIAL...A CHANGE OVER TO
BRIEFLY HEAVY/WET SNOW WOULD STILL BE POSSIBLE. THUS WILL UPDATE
THE FORECAST TO INCREASE AFTERNOON TEMPS AND ADD A MIX OF
RAIN/SNOW TO THE PRECIP TYPE.
&&
.AVIATION...ISSUED 708 AM EDT TUE MAR 26 2013
//DISCUSSION...
A BROKEN HIGH VFR CEILING DURING THE MORNING WILL CARRY SOME SNOW
FLURRIES BEFORE FILLING IN AND FALLING UNDER 5000 FEET DURING THE
AFTERNOON. DAYTIME SURFACE HEATING UNDER THE COOL AIR MASS SUPPLIED
BY PERSISTENT NORTHWEST WIND WILL RESULT IN THE LOWER CLOUD COVER
AND POSSIBLY SCATTERED COVERAGE OF HEAVIER SNOW SHOWERS THROUGH
EARLY EVENING. AFTER THAT, THERE IS CAUTIOUS OPTIMISM THAT DRY AIR
FROM NORTHERN ONTARIO WILL HELP WITH A MODEST CLEARING TREND BY
MIDNIGHT THROUGH SUNRISE WEDNESDAY.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET DURING THE AFTERNOON
AND EVENING.
&&
.PREV DISCUSSION...ISSUED 331 AM EDT TUE MAR 26 2013
SHORT TERM... TODAY AND TONIGHT
RADAR COMPOSITES INDICATE RESPECTABLE COVERAGE OF FLURRIES AND
CLUSTERS OF SNOW SHOWERS OVER LOWER MICHIGAN DURING THE EARLY
MORNING. THE 00Z SOUNDINGS FROM APX AND DTX INDICATE THIS LIGHT
ACTIVITY IS PRIMARILY A RESULT OF BROAD CYCLONIC LOW LEVEL FLOW
WORKING ON STEEP LAPSE RATES OF 7-8 C/KM BELOW 750 MB. CLUSTERS OF
SNOW SHOWERS SLIGHTLY ABOVE A FLURRY EMANATING FROM OVER LAKE HURON
ARE GETTING A BOOST FROM THE RELATIVELY WARM WATER BUT ARE JUST AN
EXTENSION OF ACTIVITY FROM UPSTREAM OVER NORTHERN ONTARIO RATHER
THAN LEGITIMATE LAKE EFFECT. SATELLITE IMAGERY ALSO INDICATES MID
LEVEL CIRCULATION WITHIN THE WEAK UPPER LEVEL TROUGH OVER THE
NORTHERN GREAT LAKES. THIS FEATURE WILL ADD SOME MID LEVEL COOLING
TO THE RATHER SUBSIDENT LOOKING 00Z APX SOUNDING AS THE TROUGH
SETTLES SOUTHWARD OVER LOWER MICHIGAN DURING THE DAY. ADD TO THAT A
COMPONENT OF DIURNAL SURFACE WARMING AND WE CAN EXPECT ONGOING
ACTIVITY TO CONTINUE IF NOT GROW IN COVERAGE BY LATE MORNING THROUGH
THE AFTERNOON. MODEL SOUNDINGS INDICATE THE ABOVE FREEZING LAYER
DEEPENING FROM THE SURFACE TO JUST ABOUT 800 FEET BY MID AFTERNOON
WHICH IS SHALLOW ENOUGH TO ALLOW SNOWFLAKES TO REACH THE SURFACE
WHERE THEY WILL MELT ON CONTACT WITH THE GROUND AS MAX TEMPS MAKE A
RUN TOWARD 40. GIVEN THE EXPECTATION OF ONLY TRACE AMOUNTS OF SNOW
AT ANY ONE LOCATION, THE INHERITED GENEROUS SCATTERED POP FORECAST
LOOKS FINE AND WILL BE CONTINUED IN THIS PACKAGE.
LEFTOVER DIURNALLY ENHANCED SNOW SHOWERS OR FLURRIES WILL LAST INTO
THE EVENING BUT WILL THEN GIVE WAY TO A CHALLENGING CLOUD FORECAST
FOR THE REST OF THE NIGHT. A SIZEABLE SLUG OF DRY AIR OVER WESTERN
QUEBEC/NE ONTARIO AT PRESS TIME WILL LIKELY HAVE A NEGATIVE
INFLUENCE ON THE POTENTIAL FOR STRATOCU MAINTENANCE OVER THE GREAT
LAKES LATER TONIGHT. THIS DRY AIR WILL WORK AGAINST CONTINUED BROAD
CYCLONIC FLOW THROUGH THE LOW LEVELS WITH ENOUGH COLD AIR BELOW 850
MB FOR SOME SIPHONING OF MOISTURE FROM THE LAKES. LOW LEVEL RH
FIELDS IN THE 00Z MODELS EXHIBIT THE USUAL HIGH BIAS IN MOISTURE
CONTENT WHICH MAKES IT A TOUGH CALL ON WHICH PROCESS WILL WIN OUT.
THE FORECAST WILL REFLECT CAUTIOUS OPTIMISM BY CUTTING CLOUD COVER
BELOW MODEL DEPICTIONS BUT STILL MAINTAIN SOME COVERAGE THROUGH
SUNRISE WEDNESDAY.
LONG TERM...WEDNESDAY THROUGH MONDAY
PV ANOMALY ASSOCIATED WITH THE NEWFOUNDLAND UPPER LOW IS STILL
PROGGED BY THE 00Z GUIDANCE TO ROTATE SOUTHWARD ACROSS THE EASTERN
GREAT LAKES LATE ON WEDNESDAY, BRINGING A GLANCING BLOW OF SHALLOW
FORCING FOR ASCENT TO SOUTHEAST MICHIGAN. ULTIMATELY MADE THE
DECISION TO REINTRODUCE POPS FOR LATE WEDNESDAY NIGHT OWING
PRIMARILY TO THE RESPECTABLE MOISTURE CONTENT THAT WILL BE
ASSOCIATED WITH THIS WAVE. 00Z NAM PLANVIEWS DEPICT OF 2 G/KG OF H20
AT H7 AND 3 G/KG AT H85. WHILE NOT PARTICULARLY IMPRESSIVE, THIS
WILL BE SUFFICIENT TO MAINTAIN SATURATION THROUGH ABOUT THE LOWEST
10KFT AND WILL ALSO PROVIDE A BRIEF WINDOW FOR ACTIVATION OF THE
DENDRITE GROWTH LAYER...AT LEAST THE LOWER REACHES OF IT. AS A
RESULT, POPS TAPERING FROM HIGH CHANCE IN THE EASTERN THUMB TO LOW
CHC ACROSS THE CENTRAL/SW CWA ARE NOW IN PLACE ALONG WITH
CATEGORICAL MENTION OF FLURRIES FOR ROUGHLY THE SAME AREA.
A STRONG SURGE OF PACIFIC JET ENERGY WILL DRIVE THE EVOLUTION OF THE
LARGE SCALE NOAM PATTERN FOR THE REMAINDER OF THE LONG TERM PERIOD.
WHAT THIS WILL MEAN LOCALLY IS THAT THE NEXT TWO DAYS WILL BE
CHARACTERIZED BY DECREASING INFLUENCE OF LARGE SCALE MOIST CYCLONIC
FLOW AND THUS INCREASED POTENTIAL TO SEE SOME SUN AND WARMING OF
TEMPERATURES BEGINNING ACROSS THE WEST ON THURSDAY. AS THE UPPER AIR
PATTERN IS PUSHED ALONG BY THE PAC JET, HIGH LATITUDE SHORTWAVE
RIDGING WILL DEAMPLIFY AND PROPAGATE ACROSS THE GREAT LAKES
THURS/FRI RESULTING IN A PATTERN OF RISING HEIGHTS AND A REBOUNDING
THERMAL FIELD. AREAS THAT SEE SUN ON THURSDAY, MOST LIKELY ACROSS
THE FAR WEST/SOUTHWEST WILL SEE TEMPERATURES JUMP INTO THE MID 40S,
WHILE THE REMAINDER OF SEMI WILL HAVE TO WAIT UNTIL FRIDAY WHEN MOST
OF THE AREA WILL SEE MID/UPPER 40S. ANOTHER ROUND OF SHORTWAVE
RIDGING LEADING A RENEWED SURGE OF DRY NW FLOW WILL KEEP THE AREA
DRY THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND AND WILL FORCE
FURTHER WARMTH TO LIFT INTO THE STATE ALLOWING HIGHS TO CLIMB TO
AROUND 50.
THE APPROACH OF THE AFOREMENTIONED PAC JET SURGE WILL BE FELT
STRONGLY SUNDAY INTO MONDAY, FIRST WITH A PERIOD OF RAIN SHOWERS
ASSOCIATED WITH THE INITIAL ROUND OF HEIGHT FALLS ON SUNDAY AND THEN
WITH THE PASSAGE OF A VIGOROUS UPPER TROUGH AS THE JET DIVES OUT OF
NW FLOW ALOFT. MONDAY WILL THEN POTENTIALLY REPRESENT A TRANSITION
DAY THAT WILL SEE THE RETURN OF BELOW NORMAL TEMPERATURES/SNOW
CHANCES. SOLID RUN-TO-RUN CONTINUITY OF THE ECMWF ALONG WITH THE
HIGH AMPLITUDE NATURE OF THE TROUGH AND GRADUAL TREND TOWARD A MORE
VIGOROUS EVOLUTION ALL LEND HIGHER THAN NORMAL CONFIDENCE IN THE
GENERAL ASPECT OF A RETURN TO COOLER WEATHER EARLY NEXT WEEK.
MULTIPLE CYCLES OF THE GFS PROVIDING RESPECTABLE CONTINUITY LATE
THIS WEEKEND INTO EARLY NEXT WEEK PROVIDE AN ADDITIONAL BOOST IN
CONFIDENCE.
MARINE...
LAKE HURON AND LOWER MICHIGAN WILL REMAIN BETWEEN HIGH PRESSURE OVER
THE PLAINS AND LOW PRESSURE OFF THE NEW ENGLAND COAST THROUGH THE
MIDDLE PART OF THE WEEK. THIS WILL MAINTAIN A PERSISTENT NORTHWEST
WIND IN THE 10 TO 15 KNOT RANGE WITH GUSTS TO 20 KNOTS. THE WIND
FIELD WILL VARY IN STRENGTH DURING THIS TIME BUT OVERALL WILL FORCE
WAVES IN EXCESS OF 4 FEET OVER THE SOUTH HALF OF LAKE HURON AT LEAST
THROUGH WEDNESDAY NIGHT. HIGH PRESSURE WILL THEN BE ABLE TO MAKE
SOME EASTWARD PROGRESS INTO THE GREAT LAKES THURSDAY WHICH WILL HELP
IMPROVE MARINE CONDITIONS HEADING INTO THE WEEKEND.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
SANILAC...UNTIL 6 AM THURSDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SC
AVIATION.....BT
SHORT TERM...BT
LONG TERM....JVC
MARINE.......BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
741 AM EDT TUE MAR 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 513 AM EDT TUE MAR 26 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A PERSISTENT BLOCKING RIDGE
FROM NRN CANADA INTO HUDSON BAY AND A TROUGH FROM THE CANADIAN
MARITIMES INTO NRN NEW ENGLAND RESULTING IN WEAK NE FLOW THROUGH THE
NRN GRREAT LAKES. AT THE SFC...NRLY FLOW PREVAILED ACROSS LAKE
SUPERIOR BETWEEN A TROUGH INTO THE ERN LAKES AND A RIDGE OVER THE
PLAINS. IR LOOP SHOWED THE BACK EDGE OF THE CLOUDS AND DEEPER
MOISTURE ADVANCING WESTWARD TOWARD THE E SIDE OF LAKE SUPERIOR.
RADAR INDICATED SCT SHSN INTO CNTRL UPPER MI WITH MORE CELLULAR THAN
BANDED PATTERN MORE TYPICAL OF LES. EVEN THOUGH 850 MB TEMPS TO NEAR
-10C ONLY PROVIDED MARGINAL OVER LAKE INSTABILITY...A WEAK SHORTWAVE
TROUGH AND ASSOCIATED 700-300 MB QVECTOR CONV HAS SUPPORTED SHSN
DEVELOPMENT. SNOW/WATER RATIO HAS INCREASED AND -FZDZ POTENTIAL
DIMINISHED WITH MOISTURE THROUGH THE DGZ.
TODAY...AS THE FORCING WITH THE SHRTWV SLIDES OFF TO THE SOUTHEAST
AND THE DEEPER MOISTURE DEPARTS...EXPECT THE SHSN TO QUICKLY
DIMINISH BY LATE MORNING. SO...ADDITIONAL SNOWFALL AMOUNTS OF ONLY A
HALF INCH OR LESS ARE EXPECTED. THERE MAY STILL BE A PERIOD WHERE
SOME -FZDZ IS POSSIBLE AS THE MOIST LAYER FALLS AT OR BELOW THE -10C
LEVEL. WITH DAYTIME HEATING AND GREATER MIXING...THERE MAY EVEN BE A
PERIOD OF SOME CLEARING INTO THE E HALF OF UPPER MI.
OTHERWISE...HIGH TEMPS WILL REMAIN BELOW NORMAL...IN THE LOWER TO
MID 30S.
TONIGHT...ANOTHER BATCH OF 925-850 MB MOISTURE IS EXPECTED TO MOVE
IN FROM THE NORTHEAST BRINGING THE POTENTIAL FOR ANOTHER ROUND OF
LAKE ENHANCED PCPN. SINCE TEMPS NEAR TO THE TOP OF THE MOIST LAYER
AT 850 MB ARE A BIT HIGHER...ONLY TO AROUND -8C...THERE MAY BE A
BETTER CHANCE FOR -FZDZ WITH ANY PCPN THAT DEVELOPS. WITH ONLY A
MODEST NRLY UPSLOPE WIND COMPONENT IN THE 20 TO 25 KNOT RANGE...ONLY
SLIGHT OR LOWER END CHANCE POPS WERE MENTIONED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM EDT TUE MAR 26 2013
LINGERING LOW LEVEL MOISTURE ROTATING IN FROM THE NORTH WILL BE
SLOWLY DIMINISHING WITH MUCH OF THE REMAINING FREEZING DRIZZLE AND
LIGHT SNOW SHOWERS/FLURRIES ENDING FOR THE MOST PART ON WEDNESDAY.
MOISTURE WILL BE TRAPPED BELOW 800MB WEDNESDAY MORNING AND FALL
AROUND OR BELOW 900MB BY WEDNESDAY EVENING...UNDER THE STRENGTHENING
INVERSION. WHILE THE MODELS DO SPIT OUT AROUND 0.01IN OR LESS
WEDNESDAY NIGHT AND THURSDAY...SIGNIFICANT PRECIP IS NOT ANTICIPATED.
THE STEADILY WARMING AFTERNOON HIGH TEMPERATURES WILL CONTINUE AS
THE 500MB HIGH OVER HUDSON BAY ON TUESDAY SINKS INTO ONTARIO AND
COMBINES WITH THE RIDGE ALREADY SET UP ACROSS THE WESTERN HALF OF
THE UNITED STATES. 850MB TEMPS AROUND -11C WEDNESDAY MORNING WILL
WARM TO -6C BY 12Z THURSDAY ON CONTINUED NORTHERLY WINDS...AND
REMAIN NEARLY STEADY THROUGH FRIDAY AFTERNOON.
A WEAK SHORTWAVE WILL SWING IN ON THE NORTHWESTERLY FLOW ALOFT
THURSDAY NIGHT INTO EARLY FRIDAY...WITH LITTLE INFLUENCE ON OUR
WEATHER. THE WRAPPED UP 500MB LOW ENCOMPASSING MUCH OF CENTRAL
CANADA FROM MID WEEK ON WILL DIG A TROUGH ACROSS THE NORTHERN PLAINS
FRIDAY NIGHT INTO SATURDAY...AND EXTEND TO THE UPPER GREAT LAKES
FROM SATURDAY THROUGH AT LEAST MONDAY. TIMING AND STRENGTH OF THE
ASSOCIATED COLD FRONT IS STILL IN QUESTION...BUT IT LOOKS LIKE IT
SHOULD BE OVER FAR WESTERN LAKE SUPERIOR SATURDAY AFTERNOON...AND
SLOWLY TRANSITION ACROSS CENTRAL AND EASTERN LAKE SUPERIOR SATURDAY
NIGHT...AS THE SFC LOW DRIFTS OVER CENTRAL ONTARIO.
WHILE THE GFS IS MORE PROGRESSIVE WITH THE FRONT...AND BUILDS COLD
HIGH PRESSURE BACK INTO WESTERN AND CENTRAL LAKE SUPERIOR ON
SUNDAY...THE ECMWF HOLDS ONTO THE SFC TROUGH A BIT LONGER. THE
DIFFERENCE SHOWS UP WELL ON THE 850MB CHART...WITH TEMPS OF -14C AT
18Z SUNDAY OFF THE GFS...WHILE THE ECMWF STILL HAS READINGS AROUND
-4C...AND KEEPS ANY COOLER READINGS BELOW -10C TO LATE SUNDAY NIGHT
AND BEYOND. THE 500MB TROUGH SHOULD PUSH EAST INTO THE LOWER GREAT
LAKES AND EASTERN ONTARIO ON MONDAY...WITH NORTHWESTERLY FLOW
REMAINING ALOFT THROUGH AT LEAST TUESDAY. ON A SIDE NOTE...THE
00Z/26 RUN OF THE ECMWF SIGNIFICANTLY INTENSIFIED THE SOUTHERN EDGE
OF THE TROUGH ROTTING THROUGH THE AREA SUNDAY NIGHT. THIS WOULD
RESULT IN A BETTER CHANCE OF PRECIPITATION...AND MUCH STRONGER
WINDS. AT 12Z MONDAY THE 12Z/25 RUN HAD WINDS OF UP TO 25KTS AT
850MB. THE LATEST RUN...WITH A SECONDARY DEEPENING SFC LOW CROSSING
CENTRAL AND EASTERN UPPER MICHIGAN SUNDAY NIGHT ALLOWS FOR A 45-60KT
850MB LLJ TO CROSS AT 12Z MONDAY. WILL BE INTERESTING IF THE 12Z RUN
LATER TODAY KEEPS UP THIS TREND...BUT FOR NOW WILL KEEP IT OUT OF
THE ONGOING FORECAST...WITH NO GALES OVER THE LAKE EXPECTED QUITE
YET.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 739 AM EDT TUE MAR 26 2013
WHILE VFR CONDITIONS PREVAIL AT CMX/IWD...MVFR WILL PERSIST AT KSAW
UNTIL LATE THIS MORNING AS DRIER AIR MOVES IN FROM THE NORTHEAST.
SOME -FZDZ MAY ALSO BE POSSIBLE AS THE DEEPER MOISTURE DEPARTS THIS
MORNING. WITH INCREASED MIXING/DRYING INTO THE AFTERNOON CONDITIONS
SHOULD IMPROVE TO VFR. HOWEVER...WITH THE LOSS OF DAYTIME
HEATING/MIXING AND WITH ADDITIONAL LOW LEVEL MOISTURE MOVING IN FROM
THE NORTHEAST AND WEAK UPSLOPE FLOW...MVFR CIGS ARE EXPECTED AGAIN
TONIGHT AT ALL TAF SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 513 AM EDT TUE MAR 26 2013
HIGH PRESSURE OVER THE PLAINS WILL ONLY SLOWLY BUILD TO THE EAST
TODAY INTO WEDNESDAY KEEPING NORTHERLY WINDS IN THE 15 TO 25 KNOT
RANGE OVER THE EAST HALF OF THE LAKE AND IN THE 10 TO 15 KNOT RANGE
OVER THE WEST. AS THE HIGH BUILDS INTO THE WESTERN GREAT LAKES FROM
WED NIGHT INTO FRIDAY WINDS WILL BE RELATIVELY LIGHT...GENERALLY
BELOW 20 KNOTS. AS THE RIDGE SHIFTS TO THE EAST OF THE AREA
SATURDAY...LIGHT TO MODERATE S TO SW WINDS WILL DEVELOP.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EDT TUE MAR 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 513 AM EDT TUE MAR 26 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A PERSISTENT BLOCKING RIDGE
FROM NRN CANADA INTO HUDSON BAY AND A TROUGH FROM THE CANADIAN
MARITIMES INTO NRN NEW ENGLAND RESULTING IN WEAK NE FLOW THROUGH THE
NRN GRREAT LAKES. AT THE SFC...NRLY FLOW PREVAILED ACROSS LAKE
SUPERIOR BETWEEN A TROUGH INTO THE ERN LAKES AND A RIDGE OVER THE
PLAINS. IR LOOP SHOWED THE BACK EDGE OF THE CLOUDS AND DEEPER
MOISTURE ADVANCING WESTWARD TOWARD THE E SIDE OF LAKE SUPERIOR.
RADAR INDICATED SCT SHSN INTO CNTRL UPPER MI WITH MORE CELLULAR THAN
BANDED PATTERN MORE TYPICAL OF LES. EVEN THOUGH 850 MB TEMPS TO NEAR
-10C ONLY PROVIDED MARGINAL OVER LAKE INSTABILITY...A WEAK SHORTWAVE
TROUGH AND ASSOCIATED 700-300 MB QVECTOR CONV HAS SUPPORTED SHSN
DEVELOPMENT. SNOW/WATER RATIO HAS INCREASED AND -FZDZ POTENTIAL
DIMINISHED WITH MOISTURE THROUGH THE DGZ.
TODAY...AS THE FORCING WITH THE SHRTWV SLIDES OFF TO THE SOUTHEAST
AND THE DEEPER MOISTURE DEPARTS...EXPECT THE SHSN TO QUICKLY
DIMINISH BY LATE MORNING. SO...ADDITIONAL SNOWFALL AMOUNTS OF ONLY A
HALF INCH OR LESS ARE EXPECTED. THERE MAY STILL BE A PERIOD WHERE
SOME -FZDZ IS POSSIBLE AS THE MOIST LAYER FALLS AT OR BELOW THE -10C
LEVEL. WITH DAYTIME HEATING AND GREATER MIXING...THERE MAY EVEN BE A
PERIOD OF SOME CLEARING INTO THE E HALF OF UPPER MI.
OTHERWISE...HIGH TEMPS WILL REMAIN BELOW NORMAL...IN THE LOWER TO
MID 30S.
TONIGHT...ANOTHER BATCH OF 925-850 MB MOISTURE IS EXPECTED TO MOVE
IN FROM THE NORTHEAST BRINGING THE POTENTIAL FOR ANOTHER ROUND OF
LAKE ENHANCED PCPN. SINCE TEMPS NEAR TO THE TOP OF THE MOIST LAYER
AT 850 MB ARE A BIT HIGHER...ONLY TO AROUND -8C...THERE MAY BE A
BETTER CHANCE FOR -FZDZ WITH ANY PCPN THAT DEVELOPS. WITH ONLY A
MODEST NRLY UPSLOPE WIND COMPONENT IN THE 20 TO 25 KNOT RANGE...ONLY
SLIGHT OR LOWER END CHANCE POPS WERE MENTIONED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM EDT TUE MAR 26 2013
LINGERING LOW LEVEL MOISTURE ROTATING IN FROM THE NORTH WILL BE
SLOWLY DIMINISHING WITH MUCH OF THE REMAINING FREEZING DRIZZLE AND
LIGHT SNOW SHOWERS/FLURRIES ENDING FOR THE MOST PART ON WEDNESDAY.
MOISTURE WILL BE TRAPPED BELOW 800MB WEDNESDAY MORNING AND FALL
AROUND OR BELOW 900MB BY WEDNESDAY EVENING...UNDER THE STRENGTHENING
INVERSION. WHILE THE MODELS DO SPIT OUT AROUND 0.01IN OR LESS
WEDNESDAY NIGHT AND THURSDAY...SIGNIFICANT PRECIP IS NOT ANTICIPATED.
THE STEADILY WARMING AFTERNOON HIGH TEMPERATURES WILL CONTINUE AS
THE 500MB HIGH OVER HUDSON BAY ON TUESDAY SINKS INTO ONTARIO AND
COMBINES WITH THE RIDGE ALREADY SET UP ACROSS THE WESTERN HALF OF
THE UNITED STATES. 850MB TEMPS AROUND -11C WEDNESDAY MORNING WILL
WARM TO -6C BY 12Z THURSDAY ON CONTINUED NORTHERLY WINDS...AND
REMAIN NEARLY STEADY THROUGH FRIDAY AFTERNOON.
A WEAK SHORTWAVE WILL SWING IN ON THE NORTHWESTERLY FLOW ALOFT
THURSDAY NIGHT INTO EARLY FRIDAY...WITH LITTLE INFLUENCE ON OUR
WEATHER. THE WRAPPED UP 500MB LOW ENCOMPASSING MUCH OF CENTRAL
CANADA FROM MID WEEK ON WILL DIG A TROUGH ACROSS THE NORTHERN PLAINS
FRIDAY NIGHT INTO SATURDAY...AND EXTEND TO THE UPPER GREAT LAKES
FROM SATURDAY THROUGH AT LEAST MONDAY. TIMING AND STRENGTH OF THE
ASSOCIATED COLD FRONT IS STILL IN QUESTION...BUT IT LOOKS LIKE IT
SHOULD BE OVER FAR WESTERN LAKE SUPERIOR SATURDAY AFTERNOON...AND
SLOWLY TRANSITION ACROSS CENTRAL AND EASTERN LAKE SUPERIOR SATURDAY
NIGHT...AS THE SFC LOW DRIFTS OVER CENTRAL ONTARIO.
WHILE THE GFS IS MORE PROGRESSIVE WITH THE FRONT...AND BUILDS COLD
HIGH PRESSURE BACK INTO WESTERN AND CENTRAL LAKE SUPERIOR ON
SUNDAY...THE ECMWF HOLDS ONTO THE SFC TROUGH A BIT LONGER. THE
DIFFERENCE SHOWS UP WELL ON THE 850MB CHART...WITH TEMPS OF -14C AT
18Z SUNDAY OFF THE GFS...WHILE THE ECMWF STILL HAS READINGS AROUND
-4C...AND KEEPS ANY COOLER READINGS BELOW -10C TO LATE SUNDAY NIGHT
AND BEYOND. THE 500MB TROUGH SHOULD PUSH EAST INTO THE LOWER GREAT
LAKES AND EASTERN ONTARIO ON MONDAY...WITH NORTHWESTERLY FLOW
REMAINING ALOFT THROUGH AT LEAST TUESDAY. ON A SIDE NOTE...THE
00Z/26 RUN OF THE ECMWF SIGNIFICANTLY INTENSIFIED THE SOUTHERN EDGE
OF THE TROUGH ROTTING THROUGH THE AREA SUNDAY NIGHT. THIS WOULD
RESULT IN A BETTER CHANCE OF PRECIPITATION...AND MUCH STRONGER
WINDS. AT 12Z MONDAY THE 12Z/25 RUN HAD WINDS OF UP TO 25KTS AT
850MB. THE LATEST RUN...WITH A SECONDARY DEEPENING SFC LOW CROSSING
CENTRAL AND EASTERN UPPER MICHIGAN SUNDAY NIGHT ALLOWS FOR A 45-60KT
850MB LLJ TO CROSS AT 12Z MONDAY. WILL BE INTERESTING IF THE 12Z RUN
LATER TODAY KEEPS UP THIS TREND...BUT FOR NOW WILL KEEP IT OUT OF
THE ONGOING FORECAST...WITH NO GALES OVER THE LAKE EXPECTED QUITE
YET.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 143 AM EDT TUE MAR 26 2013
ALTHOUGH SOME NEAR SFC DRY AIR HAS SLOWED THE PROCESS A BIT...EXPECT
CONDITIONS AT ALL 3 SITES TO TREND TOWARD MVFR AS A DISTURBANCE/
MOISTER AIR ARRIVES EARLY THIS MRNG IN THE PRESENCE OF UPSLOPE CYC
NLY FLOW. THE SOMEWHAT LOWER CONDITIONS ALONG WITH THE THREAT OF
SOME -SHSN/-FZDZ ARE MOST LIKELY AT IWD/SAW...WHERE THE LLVL FLOW
PRESENTS A GREATER UPSLOPE WIND COMPONENT. PASSAGE OF DISTURBANCE
AND DIURNAL HEATING ON TUE AFTN SHOULD ALLOW SOME IMPROVEMENT TO HI
END MVFR/LO END VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 513 AM EDT TUE MAR 26 2013
HIGH PRESSURE OVER THE PLAINS WILL ONLY SLOWLY BUILD TO THE EAST
TODAY INTO WEDNESDAY KEEPING NORTHERLY WINDS IN THE 15 TO 25 KNOT
RANGE OVER THE EAST HALF OF THE LAKE AND IN THE 10 TO 15 KNOT RANGE
OVER THE WEST. AS THE HIGH BUILDS INTO THE WESTERN GREAT LAKES FROM
WED NIGHT INTO FRIDAY WINDS WILL BE RELATIVELY LIGHT...GENERALLY
BELOW 20 KNOTS. AS THE RIDGE SHIFTS TO THE EAST OF THE AREA
SATURDAY...LIGHT TO MODERATE S TO SW WINDS WILL DEVELOP.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
413 AM EDT TUE MAR 26 2013
.UPDATE...
ISSUED AT 952 PM EDT MON MAR 25 2013
BASED ON LOCAL 00Z RAOBS...WHICH SHOW INVERTED V T/TD PROFILES
THRU ABOUT H85 CONSISTENT WITH INCRSG SOLAR ANGLE/DAYTIME HEATING...
LOWERED POPS/REMOVED FZDZ THRU ABOUT 06Z. STILL LOOKING FOR
COMBINATION OF ARRIVAL OF DEEPER MSTR/SHRTWV FM THE NE ALONG WITH
SOME ACCOMPANYING DEEP LYR QVECTOR CNVGC IN THE PRESENCE OF
NOCTURNAL COOLING AND PERSISTENT CYC LLVL NNE FLOW TO GENERATE SOME
-SHSN OVERNGT IN SPITE OF MARGINAL H85 TEMPS FOR LES. SINCE FCST
PROFILES FM MOST GUIDANCE STILL SHOW BULK OF UVV FOCUSED IN THE
LLVLS/UPSLOPE FORCING AND BLO THE DGZ...RETAINED MENTION OF FZDZ.
BUT DID CUT BACK TO PATCHY BASED ON SOMEWHAT HIER SFC DEWPT
DEPRESSIONS/DRIER LLVL AIR.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 356 PM EDT MON MAR 25 2013
...CHALLENGING FORECAST IN STORE THIS AFTERNOON THROUGH TUESDAY...
BROAD CYCLONIC FLOW IS PROGGED TO LINGER OVER MUCH OF THE GREAT
LAKES REGION THIS AFTERNOON THROUGH MUCH OF THE DAY TUESDAY AS A LOW
PRESSURE SYSTEM SLOWLY SHIFTS FROM THE OHIO VALLEY THIS
NORTHEASTWARD TOWARD THE NEW ENGLAND AREA. RADAR IS SHOWING SEVERAL
RETURNS NEAR LAKE SUPERIOR. SURFACE OBSERVATIONS AND WEBCAMS
INDICATE THAT THIS PRECIPITATION IS A MIX OF LIGHT FREEZING RAIN AS
WELL AS LIGHT SNOW SHOWERS. THE MAIN ISSUE FOR THE DAY INTO THE
NIGHT WILL BE PRECIPITATION TYPE AS SOUNDINGS SHOW ONLY MARGINAL
SUPPORT FOR SNOW DEVELOPMENT WITH THE TOP OF THE MOIST LAYER
REACHING AROUND -10C THROUGH MID MORNING. RUC AND NAM SOUNDING
INDICATE SLIGHTLY COOLER AIR...AROUND 12C...MOVING IN NEAR THE TOP
OF THE MOIST LAYER DURING THE AFTERNOON HOURS. THIS MAY TRANSITION
THE FZDZ OVER TO MORE OF A LIGHT SNOW AND FZDZ MIX OR TRANSITION
OVER TO ALL SNOW. AROUND 00Z SOUNDINGS WARM SLIGHTLY ALOFT AHEAD OF
THE NEXT 500MB TROUGH ROTATING INTO THE AREA. THIS WILL ALLOW THE
PRECIPITATION TO TRANSITION BACK TO A -FZDZ/-SHSN MIX...WHICH WILL
LAST THROUGH MID AFTERNOON BEFORE SLOWLY TAPERING OFF. CONFIDENCE
LEVEL IN ANY ONE TYPE OF PRECIPITATION IS LOW AS TEMPS ALOFT ARE
HUGGING THE -12C ISOTHERM WHICH IS WHERE ICE IS INTRODUCED INTO THE
CLOUD...THEREFORE HAVE KEPT A MIX OF FZDZ AND -SHSN IN THE FORECAST.
DELTA T VALUES ARE EXPECTED TO BE AROUND -12 TO -14 ALONG WITH MOIST
LOW LEVEL PROFILES WHICH WILL CONTINUE TO SUPPORT LAKE EFFECT
PRECIPITATION...WHICH MAY BE ENHANCED FURTHER OVERNIGHT AS THE
TROUGH PASSES DIRECTLY OVERHEAD. THERE IS ALSO AN UPSLOPE COMPONENT
WHICH MAY HELP FOCUS THE PRECIPITATION OVER THE HIGHER
TERRAIN...ESPECIALLY IN NORTH CENTRAL LOCATIONS AS WELL AS OVER THE
KEWEENAW.
TUESDAY...LAKE EFFECT SHSN AND FZDZ WILL LIKELY LINGER THROUGH THE
MID TO LATE MORNING HOURS BEFORE THE 500MB TROUGH SHIFTS TO THE
SOUTH OF THE UPPER PENINSULA. THIS WILL ALLOW SURFACE TO 850 DELTA T
VALUES TO BE AROUND -8C TO -9C...EFFECTIVELY REDUCING THE LAKE
EFFECT PRECIPITATION. SCATTERED FZDZ MAY LINGER OVER THE HIGH
TERRAIN IN CENTRAL UPPER MI AS A SIGNIFICANT AMOUNT OF LOW LEVEL
MOISTURE REMAINS IN PLACE AND UPSLOPE NORTH TO NORTH-NORTHWEST FLOW
CONTINUES TO MOVE FROM LAKE SUPERIOR INLAND.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM EDT TUE MAR 26 2013
LINGERING LOW LEVEL MOISTURE ROTATING IN FROM THE NORTH WILL BE
SLOWLY DIMINISHING WITH MUCH OF THE REMAINING FREEZING DRIZZLE AND
LIGHT SNOW SHOWERS/FLURRIES ENDING FOR THE MOST PART ON WEDNESDAY.
MOISTURE WILL BE TRAPPED BELOW 800MB WEDNESDAY MORNING AND FALL
AROUND OR BELOW 900MB BY WEDNESDAY EVENING...UNDER THE STRENGTHENING
INVERSION. WHILE THE MODELS DO SPIT OUT AROUND 0.01IN OR LESS
WEDNESDAY NIGHT AND THURSDAY...SIGNIFICANT PRECIP IS NOT ANTICIPATED.
THE STEADILY WARMING AFTERNOON HIGH TEMPERATURES WILL CONTINUE AS
THE 500MB HIGH OVER HUDSON BAY ON TUESDAY SINKS INTO ONTARIO AND
COMBINES WITH THE RIDGE ALREADY SET UP ACROSS THE WESTERN HALF OF
THE UNITED STATES. 850MB TEMPS AROUND -11C WEDNESDAY MORNING WILL
WARM TO -6C BY 12Z THURSDAY ON CONTINUED NORTHERLY WINDS...AND
REMAIN NEARLY STEADY THROUGH FRIDAY AFTERNOON.
A WEAK SHORTWAVE WILL SWING IN ON THE NORTHWESTERLY FLOW ALOFT
THURSDAY NIGHT INTO EARLY FRIDAY...WITH LITTLE INFLUENCE ON OUR
WEATHER. THE WRAPPED UP 500MB LOW ENCOMPASSING MUCH OF CENTRAL
CANADA FROM MID WEEK ON WILL DIG A TROUGH ACROSS THE NORTHERN PLAINS
FRIDAY NIGHT INTO SATURDAY...AND EXTEND TO THE UPPER GREAT LAKES
FROM SATURDAY THROUGH AT LEAST MONDAY. TIMING AND STRENGTH OF THE
ASSOCIATED COLD FRONT IS STILL IN QUESTION...BUT IT LOOKS LIKE IT
SHOULD BE OVER FAR WESTERN LAKE SUPERIOR SATURDAY AFTERNOON...AND
SLOWLY TRANSITION ACROSS CENTRAL AND EASTERN LAKE SUPERIOR SATURDAY
NIGHT...AS THE SFC LOW DRIFTS OVER CENTRAL ONTARIO.
WHILE THE GFS IS MORE PROGRESSIVE WITH THE FRONT...AND BUILDS COLD
HIGH PRESSURE BACK INTO WESTERN AND CENTRAL LAKE SUPERIOR ON
SUNDAY...THE ECMWF HOLDS ONTO THE SFC TROUGH A BIT LONGER. THE
DIFFERENCE SHOWS UP WELL ON THE 850MB CHART...WITH TEMPS OF -14C AT
18Z SUNDAY OFF THE GFS...WHILE THE ECMWF STILL HAS READINGS AROUND
-4C...AND KEEPS ANY COOLER READINGS BELOW -10C TO LATE SUNDAY NIGHT
AND BEYOND. THE 500MB TROUGH SHOULD PUSH EAST INTO THE LOWER GREAT
LAKES AND EASTERN ONTARIO ON MONDAY...WITH NORTHWESTERLY FLOW
REMAINING ALOFT THROUGH AT LEAST TUESDAY. ON A SIDE NOTE...THE
00Z/26 RUN OF THE ECMWF SIGNIFICANTLY INTENSIFIED THE SOUTHERN EDGE
OF THE TROUGH ROTTING THROUGH THE AREA SUNDAY NIGHT. THIS WOULD
RESULT IN A BETTER CHANCE OF PRECIPITATION...AND MUCH STRONGER
WINDS. AT 12Z MONDAY THE 12Z/25 RUN HAD WINDS OF UP TO 25KTS AT
850MB. THE LATEST RUN...WITH A SECONDARY DEEPENING SFC LOW CROSSING
CENTRAL AND EASTERN UPPER MICHIGAN SUNDAY NIGHT ALLOWS FOR A 45-60KT
850MB LLJ TO CROSS AT 12Z MONDAY. WILL BE INTERESTING IF THE 12Z RUN
LATER TODAY KEEPS UP THIS TREND...BUT FOR NOW WILL KEEP IT OUT OF
THE ONGOING FORECAST...WITH NO GALES OVER THE LAKE EXPECTED QUITE
YET.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 143 AM EDT TUE MAR 26 2013
ALTHOUGH SOME NEAR SFC DRY AIR HAS SLOWED THE PROCESS A BIT...EXPECT
CONDITIONS AT ALL 3 SITES TO TREND TOWARD MVFR AS A DISTURBANCE/
MOISTER AIR ARRIVES EARLY THIS MRNG IN THE PRESENCE OF UPSLOPE CYC
NLY FLOW. THE SOMEWHAT LOWER CONDITIONS ALONG WITH THE THREAT OF
SOME -SHSN/-FZDZ ARE MOST LIKELY AT IWD/SAW...WHERE THE LLVL FLOW
PRESENTS A GREATER UPSLOPE WIND COMPONENT. PASSAGE OF DISTURBANCE
AND DIURNAL HEATING ON TUE AFTN SHOULD ALLOW SOME IMPROVEMENT TO HI
END MVFR/LO END VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 356 PM EDT MON MAR 25 2013
HIGH PRESSURE IN PLACE OVER THE NORTHERN PLAINS AND LOW PRESSURE
SHIFTING EASTWARD FROM THE OHIO VALLEY TO EASTER SEABOARD WILL LEAD
TO A TIGHT PRESSURE GRADIENT OVER LAKE SUPERIOR THROUGH TUESDAY.
THIS WILL RESULT IN NORTHERLY TO NORTHWESTERLY WINDS 15 TO 25 KNOTS.
BEYOND TUESDAY AFTERNOON...HIGH PRESSURE WILL BUILD INTO THE UPPER
GREAT LAKES REGION KEEPING WINDS GENERALLY BELOW 20 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...KEC
LONG TERM...KF
AVIATION...KC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
143 AM EDT TUE MAR 26 2013
.UPDATE...
ISSUED AT 952 PM EDT MON MAR 25 2013
BASED ON LOCAL 00Z RAOBS...WHICH SHOW INVERTED V T/TD PROFILES
THRU ABOUT H85 CONSISTENT WITH INCRSG SOLAR ANGLE/DAYTIME HEATING...
LOWERED POPS/REMOVED FZDZ THRU ABOUT 06Z. STILL LOOKING FOR
COMBINATION OF ARRIVAL OF DEEPER MSTR/SHRTWV FM THE NE ALONG WITH
SOME ACCOMPANYING DEEP LYR QVECTOR CNVGC IN THE PRESENCE OF
NOCTURNAL COOLING AND PERSISTENT CYC LLVL NNE FLOW TO GENERATE SOME
-SHSN OVERNGT IN SPITE OF MARGINAL H85 TEMPS FOR LES. SINCE FCST
PROFILES FM MOST GUIDANCE STILL SHOW BULK OF UVV FOCUSED IN THE
LLVLS/UPSLOPE FORCING AND BLO THE DGZ...RETAINED MENTION OF FZDZ.
BUT DID CUT BACK TO PATCHY BASED ON SOMEWHAT HIER SFC DEWPT
DEPRESSIONS/DRIER LLVL AIR.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 356 PM EDT MON MAR 25 2013
...CHALLENGING FORECAST IN STORE THIS AFTERNOON THROUGH TUESDAY...
BROAD CYCLONIC FLOW IS PROGGED TO LINGER OVER MUCH OF THE GREAT
LAKES REGION THIS AFTERNOON THROUGH MUCH OF THE DAY TUESDAY AS A LOW
PRESSURE SYSTEM SLOWLY SHIFTS FROM THE OHIO VALLEY THIS
NORTHEASTWARD TOWARD THE NEW ENGLAND AREA. RADAR IS SHOWING SEVERAL
RETURNS NEAR LAKE SUPERIOR. SURFACE OBSERVATIONS AND WEBCAMS
INDICATE THAT THIS PRECIPITATION IS A MIX OF LIGHT FREEZING RAIN AS
WELL AS LIGHT SNOW SHOWERS. THE MAIN ISSUE FOR THE DAY INTO THE
NIGHT WILL BE PRECIPITATION TYPE AS SOUNDINGS SHOW ONLY MARGINAL
SUPPORT FOR SNOW DEVELOPMENT WITH THE TOP OF THE MOIST LAYER
REACHING AROUND -10C THROUGH MID MORNING. RUC AND NAM SOUNDING
INDICATE SLIGHTLY COOLER AIR...AROUND 12C...MOVING IN NEAR THE TOP
OF THE MOIST LAYER DURING THE AFTERNOON HOURS. THIS MAY TRANSITION
THE FZDZ OVER TO MORE OF A LIGHT SNOW AND FZDZ MIX OR TRANSITION
OVER TO ALL SNOW. AROUND 00Z SOUNDINGS WARM SLIGHTLY ALOFT AHEAD OF
THE NEXT 500MB TROUGH ROTATING INTO THE AREA. THIS WILL ALLOW THE
PRECIPITATION TO TRANSITION BACK TO A -FZDZ/-SHSN MIX...WHICH WILL
LAST THROUGH MID AFTERNOON BEFORE SLOWLY TAPERING OFF. CONFIDENCE
LEVEL IN ANY ONE TYPE OF PRECIPITATION IS LOW AS TEMPS ALOFT ARE
HUGGING THE -12C ISOTHERM WHICH IS WHERE ICE IS INTRODUCED INTO THE
CLOUD...THEREFORE HAVE KEPT A MIX OF FZDZ AND -SHSN IN THE FORECAST.
DELTA T VALUES ARE EXPECTED TO BE AROUND -12 TO -14 ALONG WITH MOIST
LOW LEVEL PROFILES WHICH WILL CONTINUE TO SUPPORT LAKE EFFECT
PRECIPITATION...WHICH MAY BE ENHANCED FURTHER OVERNIGHT AS THE
TROUGH PASSES DIRECTLY OVERHEAD. THERE IS ALSO AN UPSLOPE COMPONENT
WHICH MAY HELP FOCUS THE PRECIPITATION OVER THE HIGHER
TERRAIN...ESPECIALLY IN NORTH CENTRAL LOCATIONS AS WELL AS OVER THE
KEWEENAW.
TUESDAY...LAKE EFFECT SHSN AND FZDZ WILL LIKELY LINGER THROUGH THE
MID TO LATE MORNING HOURS BEFORE THE 500MB TROUGH SHIFTS TO THE
SOUTH OF THE UPPER PENINSULA. THIS WILL ALLOW SURFACE TO 850 DELTA T
VALUES TO BE AROUND -8C TO -9C...EFFECTIVELY REDUCING THE LAKE
EFFECT PRECIPITATION. SCATTERED FZDZ MAY LINGER OVER THE HIGH
TERRAIN IN CENTRAL UPPER MI AS A SIGNIFICANT AMOUNT OF LOW LEVEL
MOISTURE REMAINS IN PLACE AND UPSLOPE NORTH TO NORTH-NORTHWEST FLOW
CONTINUES TO MOVE FROM LAKE SUPERIOR INLAND.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 356 PM EDT MON MAR 25 2013
UPPER TROUGH THAT HAS BEEN INFLUENCING THE AREA OVER THE LAST
SEVERAL DAYS WILL BEGIN TO SHIFT EAST TUESDAY NIGHT INTO
WEDNESDAY...ALLOWING A WEAK UPPER RIDGE AND SURFACE HIGH PRESSURE TO
MOVE IN WEDNESDAY NIGHT AND REMAIN THROUGH FRIDAY.
LINGERING MOISTURE UNDER THE CYCLONIC FLOW FROM THE UPPER AND
SURFACE LOW OF THE NEW ENGLAND STATES WILL CONTINUE TO BRING THE
POTENTIAL FOR CLOUDS AND PRECIPITATION FOR TUESDAY NIGHT AND
WEDNESDAY. THIS WILL BE ESPECIALLY TRUE FOR LOCATIONS FAVORED BY
NORTH TO NORTHWEST WINDS. MODELS ARE FAIRLY PERSISTENT ON THE LOWER
LEVEL MOISTURE...925-850MB...BEING PRESENT FOR TUESDAY NIGHT INTO
WEDNESDAY MORNING WHILE A SURFACE TROUGH DROPS SOUTH ACROSS EASTERN
LAKE SUPERIOR. BEST CHANCES FOR PRECIPITATION LOOK TO BE ON TUESDAY
NIGHT INTO WEDNESDAY MORNING...BEFORE THE DEEPER MOISTURE DEPARTS
AND SUBSIDENCE FROM THE APPROACHING HIGH BEGINS TO INFLUENCE THE
CLOUD THICKNESS. WILL CONTINUE TO MENTION SLIGHT CHANCE AND A FEW
LOCALIZED CHANCE POPS FOR THE FAVORED NORTH-NORTHWEST LOCATIONS.
TYPE LOOKS TO BE A CONCERN AGAIN ON TUESDAY NIGHT INTO
WEDNESDAY...WITH CLOUD TOP TEMPERATURES BARELY RISING ABOVE -10C. AS
HAS BEEN THE CASE OVER THE LAST COUPLE OF DAYS...THE LIGHTER SHOWERS
WILL LIKELY BE FZDZ AND IF ANY STRONGER SHOWERS OCCUR THERE COULD BE
SNOW ASSOCIATED WITH IT. WILL LIMIT THE SNOW MENTION THOUGH...AS
CLOUD TOPS APPEAR TO BE A COUPLE DEGREES WARMER THAN THE LAST COUPLE
OF DAYS.
WEDNESDAY NIGHT INTO THURSDAY WILL BE THE TRANSITION PERIOD...AS THE
HIGH PRESSURE RIDGE MOVES OVER THE AREA FROM THE UPPER MISSISSIPPI
VALLEY AND THE RESIDUAL MOISTURE BECOMES FORCED BELOW 925MB. THIS
DOES LEAD TO SOME CONCERN FOR LOW CLOUDS BECOMING TRAPPED OVER THE
AREA ON WEDNESDAY NIGHT. SFC TO 925MB DELTA-T VALUES ARE ONLY AROUND
8-9C...SO LAKE INFLUENCE WILL BE BE LIMITED. BUT IF CLOUDS ARE STILL
PRESENT FROM WEDNESDAY...THE INCREASING SUBSIDENCE INVERSION AND
LACK OF MIXING DURING THE OVERNIGHT HOURS WILL TRY TO KEEP THEM IN
PLACE. THUS...WILL TRY TO HOLD ONTO MORE OF A PARTLY/MOSTLY CLOUDY
SKY FOR WEDNESDAY NIGHT AND THEN HAVE DAYTIME MIXING TRY TO REDUCE
CLOUDS SOMEWHAT ON THURSDAY. ONE THING TO WATCH ON THURSDAY WILL BE
THE INCREASING SFC-925MB LAPSE RATES IF BREAKS DO OCCUR. THIS COULD
LEAD TO DIURNAL CU REDEVELOPING OVER INTERIOR WEST LOCATIONS WHERE
LAPSE RATES APPROACH 9C/KM. WITH PLENTY OF DRY AIR...THURSDAY NIGHT
INTO FRIDAY SHOULD BE DRY AND PARTLY/MOSTLY CLEAR EVEN THOUGH A
SHORTWAVE MOVES ACROSS THE AREA IN THE NORTHWEST FLOW.
EXPECT GRADUAL WARMING TEMPERATURES THROUGH THE WEEK...ESPECIALLY
FOR THURSDAY AND FRIDAY WITH THE LATE MARCH SUNSHINE. WEDNESDAY
SHOULD SEE HIGHS IN THE MID-UPPER 30S AND THEN UPPER 30S THROUGH MID
40S FOR THURSDAY AND FRIDAY. 00Z ECMWF AND MOST OF IT/S ENSEMBLE
MEMBERS HAVE KSAW REACHING THE LOW 40S ON FRIDAY AND SATURDAY.
THUS...IT IS LOOKING LIKE OUR OFFICE WILL END UP REACHING 40 DEGREES
AND KEEP THIS MARCH FROM BEING THE FIRST MARCH ON RECORD WHERE WE
DIDN/T REACH 40 DEGREES.
CHANGES LOOK TO ARRIVE FOR THIS WEEKEND...AS A STRONG SHORTWAVE
DIVES SOUTHEAST THROUGH CENTRAL CANADA AND INTO THE UPPER GREAT
LAKES FOR LATE SATURDAY INTO SUNDAY. MODELS ARE FAIRLY CONSISTENT
ON THIS IDEA...WHICH INCREASES CONFIDENCE INTO THE FIRST PART OF
NEXT WEEK. AT THIS TIME...LOOKS LIKE ASSOCIATED COLD FRONT WILL
MOVE THROUGH ON SATURDAY AFTERNOON/NIGHT. BASED OFF THICKNESS AND
THERMAL PROFILES...LOOKS LIKE A MIX OF RAIN/SNOW AS THE FRONT MOVES
THROUGH. WITH THE DRY HIGH IN PLACE...QPF AMOUNTS LOOK TO BE
LIMITED AT THIS POINT WITH THE INITIAL FRONT. THEN BEHIND THE FRONT
ON SUNDAY...MAIN SHORTWAVE MOVES THROUGH AND COLDER 850MB TEMPS
SURGE SOUTHEAST AND REACH -12C/ECMWF OR -10C/GFS BY MONDAY MORNING.
WITH THE NORTHWEST FLOW GENERATED BY THE HIGH OVER THE NORTHERN
PLAINS...WOULD SOME LAKE EFFECT SNOW SHOWERS IN THE NORTHWEST
WIND FAVORED LOCATIONS FOR MONDAY. WILL TREND POPS UP SLIGHTLY FROM
A GENERAL MODEL CONSENSUS FOR THAT TIME FRAME NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 143 AM EDT TUE MAR 26 2013
ALTHOUGH SOME NEAR SFC DRY AIR HAS SLOWED THE PROCESS A BIT...EXPECT
CONDITIONS AT ALL 3 SITES TO TREND TOWARD MVFR AS A DISTURBANCE/
MOISTER AIR ARRIVES EARLY THIS MRNG IN THE PRESENCE OF UPSLOPE CYC
NLY FLOW. THE SOMEWHAT LOWER CONDITIONS ALONG WITH THE THREAT OF
SOME -SHSN/-FZDZ ARE MOST LIKELY AT IWD/SAW...WHERE THE LLVL FLOW
PRESENTS A GREATER UPSLOPE WIND COMPONENT. PASSAGE OF DISTURBANCE
AND DIURNAL HEATING ON TUE AFTN SHOULD ALLOW SOME IMPROVEMENT TO HI
END MVFR/LO END VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 356 PM EDT MON MAR 25 2013
HIGH PRESSURE IN PLACE OVER THE NORTHERN PLAINS AND LOW PRESSURE
SHIFTING EASTWARD FROM THE OHIO VALLEY TO EASTER SEABOARD WILL LEAD
TO A TIGHT PRESSURE GRADIENT OVER LAKE SUPERIOR THROUGH TUESDAY.
THIS WILL RESULT IN NORTHERLY TO NORTHWESTERLY WINDS 15 TO 25 KNOTS.
BEYOND TUESDAY AFTERNOON...HIGH PRESSURE WILL BUILD INTO THE UPPER
GREAT LAKES REGION KEEPING WINDS GENERALLY BELOW 20 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...KEC
LONG TERM...SRF
AVIATION...KC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
629 PM CDT WED MAR 27 2013
.AVIATION...
00Z TAFS FOR KOMA...KLNK...AND KOFK.
AVIATION CONCERNS TONIGHT WILL BE FOG POTENTIAL. MOST SHORT-RANGE
MODELS ARE CURRENTLY OVERDOING SURFACE DEWPOINTS...HOWEVER ECMWF
AND RAP ARE HANDLING THIS BETTER. OVERNIGHT...EC/RAP DROP DEWPOINT
DEPRESSIONS TO 2 TO 3 DEGREES FOR THE TAF SITES. VFR CONDITIONS
EXPECTED TO CONTINUE FOR MUCH OF TONIGHT AND WITH WEAK BOUNDARY
LAYER FLOW HAVE INCLUDED SOME MVFR FOG BETWEEN 10 AND 14Z. WILL
NEED TO MONITOR LATER TONIGHT AND EARLY THURSDAY. A WEATHER
DISTURBANCE SHOULD BRING AN INCREASE IN SOME MID CLOUDS THURSDAY
MORNING AND INCLUDED SOME CIGS FL100.
&&
.PREV DISCUSSION... /ISSUED 317 PM CDT WED MAR 27 2013/
DISCUSSION...
THREE MAJOR UPPER LEVEL LOWS WILL PLAY ROLES IN THE FORECAST
THROUGH THE MIDDLE OF NEXT WEEK. THE FIRST IS OFF THE EASTERN
CANADIAN COAST WITH A TROUGH EXTENDING THROUGH NEW ENGLAND INTO
THE GREAT LAKES. THE SECOND IS A LOW OVER ALASKA AND THE NORTHWEST
TERRITORIES. AND THE THIRD WAS DEVELOPING IN THE SOUTHERN GULF OF
ALASKA. AS THE NEW ENGLAND TROUGH ROTATES OFF THE EAST COAST
AROUND THE FIRST LOW...AND THE THIRD LOW DROPS SOUTH FROM THE GULF
OF ALASKA...GRADUALLY RISING HEIGHTS WILL ENSUE ACROSS THE MIDDLE
OF THE COUNTRY THROUGH AT LEAST FRIDAY. THIS SIGNALS WARMING
TEMPERATURES FOR OUR AREA THE REMAINDER OF THE WEEK.
THE SECOND LOW WILL SLOWLY DRIFT ACROSS NORTHERN CANADA THROUGH
SATURDAY BEFORE DROPPING SOUTHEAST INTO THE NORTHERN GREAT LAKES
EARLY NEXT WEEK. A SIGNIFICANT SHORTWAVE TROUGH WILL RACE SOUTHEAST
THROUGH THE ROCKIES AND INTO THE PLAINS SATURDAY AHEAD OF THIS
LOW...DRIVING A COLD FRONT THROUGH THE MIDDLE OF THE COUNTRY. A
CHANCE FOR PRECIPITATION AND SLIGHTLY COOLER TEMPERATURES WILL
RESULT FROM THIS FEATURE.
AS THE SECOND LOW MOVES INTO THE GREAT LAKES MONDAY...A SECONDARY
COLD PUSH WILL OVERSPREAD THE NORTHERN AND CENTRAL PLAINS...BRINGING
MUCH COLDER TEMPERATURES BACK INTO THE FORECAST. THEN MODELS ARE
STARTING TO CONVERGE ON THE MOVEMENT/TIMING OF LOW NUMBER
THREE...MOVING IT THROUGH THE FOUR CORNERS REGION TUESDAY WHILE
MAINTAINING NORTHWEST FLOW ACROSS OUR AREA THROUGH WEDNESDAY.
TONIGHT THROUGH FRIDAY...GENERAL SOUTHERLY FLOW WILL RETURN TO
THE REGION AHEAD OF SLOWLY DEEPENING LOW PRESSURE IN THE LEE OF
THE ROCKIES. LOW CLOUDS MAY DEVELOP BOTH TONIGHT AND THURSDAY
NIGHT AS LOW LEVEL THETA-E ADVECTION INCREASES. LOW LEVEL RH PROGS
SUGGEST WESTERN SECTIONS OF OUR CWA WILL SEE THE HIGHEST CHANCE
FOR LOWER CLOUDS TONIGHT...WITH ALL OF OUR AREA FRIDAY MORNING.
HOWEVER LOWER CLOUDS SHOULD BE SHORT-LIVED EACH MORNING WITH
PLENTY OF SUNSHINE EXPECTED IN THE AFTERNOONS. SOME WARM ADVECTION
MID CLOUDS ARE LIKELY IN OUR NORTH THURSDAY AFTERNOON AND
NIGHT...AND COULD SQUEEZE OUT A FEW SPRINKLES. OTHERWISE EXPECT
HIGHS TO REACH THE 50S THURSDAY AND PERHAPS 60 FRIDAY GIVEN RISING
HEIGHTS AND WARMER AIRMASS PUSHING INTO THE REGION.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...COLD FRONT WILL SWEEP THROUGH
OUR AREA ON SATURDAY...WITH MOST MODELS SUGGESTING WIND SHIFT WILL
BE EAST OF THE CWA BY EARLY EVENING. WARM/MOIST ADVECTION FRIDAY
NIGHT WILL SPREAD WEAK ELEVATED INSTABILITY ACROSS SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA...BUT CONVERGENCE TO GET PRECIP GOING IS
TOUGH TO NAIL DOWN UNTIL FRONT APPROACHES SATURDAY. SO WILL
MAINTAIN A SMALL CHANCE FOR ELEVATED SHOWERS/STORMS FOR A GOOD
PART OF THE AREA FRIDAY NIGHT...AND KEEP LIKELY CHANCES FOR
SHOWERS/STORMS SATURDAY. GFS FORECAST SOUNDINGS SHOW 300-900 J/KG
OF SKINNY CAPE SUGGESTING AT LEAST ISOLATED RUMBLES COULD OCCUR.
LINGERING SHOWERS MAY AFFECT OUR SOUTHEAST SATURDAY NIGHT...BUT
MOST OF THE NIGHT AND SUNDAY SHOULD BE DRY. HIGHS SATURDAY WILL BE
AFFECTED BY INCREASING CLOUDS...BUT A WARMER START IN THE 40S WILL
ALLOW HIGHS TO REBOUND BACK INTO THE 50S OR LOWER 60S. AND DESPITE
A CHANGE TO NORTHERLY WINDS SUNDAY...ONLY WEAK COOL ADVECTION AND
PLENTY OF SUNSHINE SUGGEST HIGHS REBOUNDING FROM MORNING LOWS IN
THE 30S BACK INTO THE 50S. THERE IS ONE CAVEAT FOR SUNDAY
AFTERNOON. GFS SHOWS A SHORTWAVE/JET SEGMENT KNIFING INTO THE
REGION...AND PRODUCING A SIGNIFICANT SWATH OF PRECIPITATION LATE
IN THE DAY AND EVENING...WITH 850 TEMPERATURES AND COOLING
SOUNDINGS SUGGESTING A GOOD PART OF THAT PRECIPITATION COULD
BECOME SNOW LATE IN THE DAY. NEW 12Z ECMWF ALSO SHOWS
PRECIPITATION BUT IS LEST ROBUST. AM NOT GOING TO ALTER CURRENT
FORECAST TOO FAR FROM THE CHANCE FOR RAIN OR SNOW SUNDAY
NIGHT...BUT THIS BEARS WATCHING.
MONDAY THROUGH WEDNESDAY...SECONDARY COLD FRONT SHOULD USHER IN EVEN
COLDER AIR MONDAY MORNING...WHICH THEN HOLDS ON INTO MID WEEK. HIGHS
IN THE 30S OR 40S MONDAY LOOK TO STAY IN THE 40S INTO WEDNESDAY.
PRECIPITATION CHANCES SHOULD REMAIN RELATIVELY LOW GIVEN NORTHWEST
MID LEVEL FLOW.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
723 PM EDT WED MAR 27 2013
.SYNOPSIS...
A COLD NORTHWEST FLOW WILL PERSIST THROUGH THE REMAINDER OF THE WORK
WEEK...OCCASIONALLY BRINGING SCATTERED SNOW AND RAIN SHOWERS.
TEMPERATURES WILL FINALLY BUT BRIEFLY TURN SLIGHTLY MILDER OVER
THE WEEKEND...AND THEN WE WILL RETURN TO A COOL UNSETTLED PATTERN.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
715 PM UPDATE...
DIURNAL CONVECTION CONTS AT THIS TIME AIDED BY TROF ALOFT. HV
TWEAKED POPS TO KEEP SCTD SNOW SHOWERS IN ACRS MAJORITY OF CWA
TONIGHT UNTIL TROF PASSES OFF TO THE SOUTH. ALSO DID SLIGHT
ADJUSTMENT TO KEEP UP WITH HRLY TEMP TRENDS BUT NO CHGS NEEDED TO
MINS. HV WORDED SNOW/RAIN SHOWERS IN THRU 01Z FOR VLY LOCATIONS
THEN BCMG ALL SNOW AFT THAT TIME.
4 PM UPDATE...
QUICK UPDATE TO EXPAND 50 POPS ACRS MOST OF THE CWA WITH EXCEPTION
OF NERN CNTYS AS THEY RMN UNDER SUBSIDENCE AFT FIRST S/WV PASSED
BY. EXPECT SNOW SHOWERS TO WEAKEN BY 00Z TNGT BFR RE-DVLPNG AFT
MIDNIGHT AS MAIN UL TROF DROPS THRU AND REGENERATES POPS.
130 PM UPDATE...
WEAK WAVE IS DROPPING OVER THE REGION WHICH WITH DIURNAL HEATING
IS CAUSING EXPECTED BLOSSOM OF SCATTERED RAIN/SNOW SHOWERS AND
SPRINKLES/FLURRIES. AS PER LOCAL HIGH RESOLUTION MODELS...WE
ARE HAVING A RELATIVE MAXIMUM IN DIURNAL ACTIVITY ACROSS THE
CENTRAL TO SOUTHWESTERN ZONES COMPARED TO THE NORTHEAST. SUBSIDENCE
AND DRIER COLUMN THIS AFTERNOON/EARLY EVENING BEHIND WAVE IN THE
NORTHEASTERN ZONES INCLUDING MOHAWK VALLEY AND NY THRUWAY...SHOULD
LEAD TO RELATIVE MINIMUM IN ACTIVITY THERE...BEFORE BETTER WAVE
DROPS IN LATER TONIGHT. FORECAST DETAILS HAVE BEEN ADJUSTED
ACCORDINGLY.
RUC/RAP SOUNDINGS HAVE STEEPER LAPSE RATES AND THUS MORE
INSTABILITY COMPARED TO THE NAM. GIVEN THAT MAV AND ESPECIALLY
MET GUIDANCE HAVE BEEN TOO COLD LATELY...AND THE EXTRA ENERGY FROM
EARLY SUNSHINE TODAY...THE MORE UNSTABLE RUC SOUNDINGS ARE A
BETTER REPRESENTATION. CONVECTIVE NATURE TO THE SCATTERED SHOWERS
ARE THUS BEING REALIZED AS CAN BE SEEN ON THE RADAR THE LAST HOUR
OR SO...COMPLETE WITH BURSTS OF GRAUPEL. ALSO...MET GUIDANCE AGAIN
HAS BEEN SHOWN TO BE MUCH TOO COOL FOR TEMPERATURES THIS AFTERNOON.
AFTER DIURNAL ACTIVITY WANES LATE AFTERNOON INTO EVENING...A
BETTER UPPER TROUGH WILL DROP NORTH TO SOUTH 03Z-09Z
OVERNIGHT...ALLOWING SCATTERED SNOW SHOWERS TO
REDEVELOP...ESPECIALLY CENTRAL NY. THAT BEING SAID...ACCUMULATIONS
WILL BE GENERALLY ONLY A FEW TO SEVERAL TENTHS OF AN INCH FOR
MOST LOCATIONS. WITH AMOUNT OF CLOUDS OVERNIGHT...NOT FIGURING ON
MUCH RADIATIONAL COOLING AND SO NEAR OR SLIGHTLY ABOVE BLENDED
GUIDANCE IS EXPECTED FOR LOW TEMPERATURES /MID 20S TO AROUND 30/.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
230 PM UPDATE...
MAIN UPPER TROUGH AXIS WILL FINISH EXITING SOUTH THURSDAY
MORNING. MODELS SUGGEST THAT A WEAKER SHORTWAVE WILL STILL SLIP
THROUGH DURING THE DAY. HOWEVER...THICKNESSES WILL BE A GOOD 5 OR SO
DECAMETERS HIGHER...AND SO LAPSE RATES WILL NOT BE AS STEEP. AS
DIURNAL ENERGY AGAIN TRIES TO BURP UP SCATTERED SHOWERS...THERE WILL
NOT BE AS MUCH INSTABILITY COMPARED TO 24 HOURS PRIOR...AND RIDGING
WILL ALREADY BE INITIATING ALOFT. I ONLY PLACED SLIGHT TO LOW CHANCE
POPS...AND MAINLY UP TO MIDDAY...FOR DIURNAL ENHANCEMENT AND PASSING
WAVE. AS WITH RECENT DAYS...I HAVE STAYED ON WARM SIDE OF MODEL
GUIDANCE FOR HIGH TEMPERATURES THURSDAY...ESPECIALLY THE MAV WHICH
HAS BEEN MUCH TOO COOL LATELY. MAINLY 40S AREAWIDE. WETBULBING AGAIN
WILL ALLOW SNOW OR GRAUPEL WITHIN THE SHOWERS DESPITE TEMPERATURES
GETTING WELL ABOVE FREEZING.
WEAK RIDGING THURSDAY EVENING...WILL GIVE WAY TO ANOTHER WEAK TROUGH
THAT WILL DIP INTO THE AREA FRIDAY...THOUGH FOR THE FIRST TIME IN
QUITE AWHILE...NOT ONE ASSOCIATED WITH THE RESIDENT UPPER LOW IN
THE CANADIAN MARITIMES. MOISTURE WILL BE FAIRLY SHALLOW...YET LAPSE
RATES ALSO STEEPER. THUS WITH THE PASSING FEATURE...DIURNAL
INSTABILITY WILL PROBABLY HELP TO REALIZE ADDITIONAL SCATTERED
RAIN/SNOW SHOWERS.
BY SATURDAY...CYCLONIC FLOW WILL GIVE WAY TO A BETTER RIDGE ON ITS
WAY IN. MOISTURE GETS VERY SHALLOW AS WARM AIR ADVECTION ENSUES
ALOFT. FIGURING ON A DRY NEAR CLIMATOLOGY DAY WITH STRATOCUMULUS
BECOME MORE CELLULAR AND THEN SCATTERING OUT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. A BRIEF BREAK IN THE COLD SAT NGT TO
SUNDAY WITH SFC HIGH PRESSURE AND AN UL RIDGE. A COLD FRONT GOES
THROUGH SUN AFTN AND EVE WITH MOSTLY RAIN...WHICH MAY CHANGE TO
SNOW BEFORE ENDING. ANOTHER BREAK LATE SUN NGT TO MON BEFORE
COLDER AIR COMES IN MON NGT WITH SNOW...A COLD FRONT AND STRONG
SHORT WAVE. THE LOW LEVEL FLOW SHIFTS TO NW BEHIND THE FRONT SO
SNOW SHOWERS FOR TUES AND WED. COOLER THAN NORMAL WITH A DEEP
UPPER LEVEL TROF IN THE NE US.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
LINE OF SNOW SQUALLS MOVING TOWARD BGM WILL PRODUCE TEMPO IFR
CONDITIONS BETWEEN 630 PM AND 8 PM EDT. THEREAFTER THE CONVECTIVE
ELEMENTS OF THE SNOW/RAIN SHOWERS WILL WEAKEN AND DISSIPATE.
HOWEVER ENERGY MOVING OFF THE LAKES WILL CAUSE LIGHT SNOW SHOWERS
OR FLURRIES TO REFORM OVERNIGHT. THIS ACTIVITY WILL BE VERY HIT
AND MISS, AND WILL BE ON THE LIGHT SIDE. SO WE WILL FORECAST MVFR
RESTRICTIONS WITHIN SNOW SHOWERS.
GENERALLY LOW VFR TO HIGH MVFR CEILINGS WILL PERSIST INTO MIDDAY
THURSDAY. WINDS WILL BE WESTERLY AROUND 10 KNOTS.
.OUTLOOK...
THUR AFTN TO FRI NGT...OCNL RESTRICTIONS IN -SHSN/FLRYS
THROUGHOUT THIS PD...MAINLY FOR THE CNY TERMINALS.
SAT TO SUN AM...MAINLY VFR.
SUN AFTN TO EVE...MVFR POSSIBLE IN RAIN SHOWERS.
LATE SUN NGT TO MON...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP/PVN
SHORT TERM...MDP
LONG TERM...TAC
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
106 PM EDT TUE MAR 26 2013
.SYNOPSIS...
LOW PRESSURE OFF THE NEW ENGLAND COAST WILL MOVE NORTHEAST TODAY
WHILE AN UPPER LEVEL DISTURBANCE MOVES ACROSS NORTH CAROLINA FROM
THE WEST THIS AFTERNOON AND EVENING. STRONG HIGH PRESSURE WILL BUILD
INTO THE AREA FROM THE WEST THROUGH FRIDAY. THE HIGH WILL BE OVER
THE AREA SATURDAY AND MOVE OFF OF THE COAST SUNDAY. A COLD FRONT
WILL APPROACH THE REGION MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM TUESDAY...LATEST VSBY SATELLITE IMAGERY SHOWING
WIDESPREAD STRATOCUMULUS ACROSS THE REGION. NAM12 HAS BACKED OFF
THE LIGHT PRECIP FOR THE AFTERNOON...BUT THE RAP AND LATEST 4 KM
WRF MODELS STILL CONTINUE TO SHOW SPOTTY LIGHT SPRINKLES AND
SHOWERS AND HAVE A SLIGHT CHC POP OVER MOST AREAS THROUGH 00Z.
AMOUNTS WILL BE VERY LIGHT WHERE MEASURABLE...AT PERHAPS A
HUNDREDTH OR TWO. WITH THE CLOUDY SKIES...MAX TEMPERATURES WILL NOT
GO UP MUCH MORE THAN CURRENT LEVELS IN THE UPPER 40S TO AROUND 50.
OTHER THAN THE POPS...NO MAJOR CHANGES TO FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 330 AM TUESDAY...SCT-BKN SCU WITH PSBL ISOLD SHOWERS WILL
LINGER INTO EARLY EVENING...THEN DECREASING CLOUDS EXPECTED WITH
LOSS OF HEATING. SECONDARY CAA SURGE FOLLOWING SHRT WV EXPECTED TO
PRODUCE ENOUGH WIND TO PRECLUDE DECOUPLING OVERNIGHT...BUT CONTINUED
SLIGHT COOLING OF AIR MASS WILL SUPPORT MIN TEMPS IN LOW-MID 30S
INLAND WITH UPR 30S OBX. NW HALF OF ONSLOW COUNTY...WHERE GROWING
SEASON IS IN EFFECT...COULD SEE LOWS AROUND 32...BUT WILL LET DAY
SHIFT TAKE A LOOK AT PSBL NEED FOR FREEZE WARNING THERE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 3 AM TUE...A SLOW WARMING TREND IS IN STORE FOR THE EXTENDED
PERIOD DUE TO A STEADILY CHANGING SURFACE PATTERN. THE LARGE
CYCLONIC FLOW AROUND THE DEEP LOW FAR TO THE NORTHEAST WILL SLOWLY
BE REPLACED BY A SURFACE RIDGE BUILDING IN FROM THE WEST. THE HIGH
WILL BE CENTERED OVER THE AREA FRIDAY AND SATURDAY. THE HIGH WILL
MOVE OFF THE SOUTHEAST COAST SUNDAY. THE NEXT FRONT WILL APPROACH
FROM THE NORTHWEST MONDAY. HIGH TEMPS WEDNESDAY WILL BE IN THE
LOWER 50S...WARMING TO THE MID/UPPER 60S BY EARLY NEXT WEEK. ONLY
PRECIP IN THE FORECAST WILL BE A CHANCE OF SHOWERS SUNDAY NIGHT
AND MONDAY ASSOCIATED WITH THE APROACHING FRONT.
NOTE: GROWING SEASON WILL BEGIN ON WEDNESDAY FOR REST OF FORECAST
AREA...AND FREEZE WATCH/WARNING MAY BE NEEDED FOR INLAND SECTIONS
WED NIGHT/THU MORNING.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 12Z WEDNESDAY/...
AS OF 1 PM TUESDAY...WIDESPREAD 5000-6000 FT STRATOCUMULUS WILL
CONTINUE THROUGH LATE AFTERNOON BUT SHOULD DISSIPATE WITH LOSS OF
HEATING TONIGHT. VFR CONDITIONS TO CONTINUE.
LONG TERM /WED THRU SAT/
AS OF 3 AM TUE...VFR WITH MOSTLY CLEAR SKIES AND A LIGHT NORTHWEST
FLOW THROUGH THE PERIOD.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM TUESDAY...SMALL CRAFT ADVISORIES HAVE EXPIRED OVER THE
PAMLICO SOUND AND TWO SOUTHERN LEGS. THEY WILL REMAIN IN EFFECT
FOR THE NEXT HOUR OR SO SLOWLY...BUT WITH THE BUOY 13 MILES EAST
OF OREGON INLET STILL HOVERING AROUND 6 FEET...MAY EXTEND THE SCA
SHORTLY.
LONG TERM /WED THRU SAT/
AS OF 3 AM TUE...LATEST RUN OF THE GFS AND ECMWF SHOWS THEM IN
GOOD AGREEMENT. USED A CONSENSUS BLEND FOR THE FORECAST. NORTHWEST
FLOW WILL CONTINUE OVER THE AREA. CYCLONIC FLOW AROUND DEEP LOW
FAR TO THE NORTHEAST WILL GRADUALLY GIVE WAY TO A SURFACE RIDGE
BUILDING IN FROM THE WEST THROUGH THE WEEKEND. WINDS AND SEAS
WILL SLOWLY SUBSIDE AS A RESULT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR AMZ150-152-
154.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...HSA
AVIATION...CTC/HSA
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
915 AM EDT TUE MAR 26 2013
.SYNOPSIS...
LOW PRESSURE OFF THE NEW ENGLAND COAST WILL MOVE NORTHEAST TODAY
WHILE AN UPPER LEVEL DISTURBANCE MOVES ACROSS NORTH CAROLINA FROM
THE WEST THIS AFTERNOON AND EVENING. STRONG HIGH PRESSURE WILL BUILD
INTO THE AREA FROM THE WEST THROUGH FRIDAY. THE HIGH WILL BE OVER
THE AREA SATURDAY AND MOVE OFF OF THE COAST SUNDAY. A COLD FRONT
WILL APPROACH THE REGION MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 905 AM TUESDAY...ANOTHER CHILLY DAY IN STORE WITH MAX TEMPS
IN THE UPPER 40S TO LOWER 50S. LATEST RAP MODEL...ALONG WITH THE
EMC AND SPC 4 KM WRF MODELS AND NAM12 SHOW A FEW LIGHT SHOWERS OR
SPRINKLES WILL BE POSSIBLE OVER EASTERN NORTH CAROLINA THIS
AFTERNOON WITH STRONG H5 SHORTWAVE LINGERING JUST TO THE SOUTH OF
THE REGION. THE BEST CHANCE OF ANY MEASUREABLE PRECIP WILL BE IN
THE NORTHEAST AREAS BETWEEN THE SOUNDS. NO OTHER MAJOR CHANGES TO
THE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 330 AM TUESDAY...SCT-BKN SCU WITH PSBL ISOLD SHOWERS WILL
LINGER INTO EARLY EVENING...THEN DECREASING CLOUDS EXPECTED WITH
LOSS OF HEATING. SECONDARY CAA SURGE FOLLOWING SHRT WV EXPECTED TO
PRODUCE ENOUGH WIND TO PRECLUDE DECOUPLING OVERNIGHT...BUT CONTINUED
SLIGHT COOLING OF AIR MASS WILL SUPPORT MIN TEMPS IN LOW-MID 30S
INLAND WITH UPR 30S OBX. NW HALF OF ONSLOW COUNTY...WHERE GROWING
SEASON IS IN EFFECT...COULD SEE LOWS AROUND 32...BUT WILL LET DAY
SHIFT TAKE A LOOK AT PSBL NEED FOR FREEZE WARNING THERE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 3 AM TUE...A SLOW WARMING TREND IS IN STORE FOR THE EXTENDED
PERIOD DUE TO A STEADILY CHANGING SURFACE PATTERN. THE LARGE
CYCLONIC FLOW AROUND THE DEEP LOW FAR TO THE NORTHEAST WILL SLOWLY
BE REPLACED BY A SURFACE RIDGE BUILDING IN FROM THE WEST. THE HIGH
WILL BE CENTERED OVER THE AREA FRIDAY AND SATURDAY. THE HIGH WILL
MOVE OFF THE SOUTHEAST COAST SUNDAY. THE NEXT FRONT WILL APPROACH
FROM THE NORTHWEST MONDAY. HIGH TEMPS WEDNESDAY WILL BE IN THE
LOWER 50S...WARMING TO THE MID/UPPER 60S BY EARLY NEXT WEEK. ONLY
PRECIP IN THE FORECAST WILL BE A CHANCE OF SHOWERS SUNDAY NIGHT
AND MONDAY ASSOCIATED WITH THE APROACHING FRONT.
NOTE: GROWING SEASON WILL BEGIN ON WEDNESDAY FOR REST OF FORECAST
AREA...AND FREEZE WATCH/WARNING MAY BE NEEDED FOR INLAND SECTIONS
WED NIGHT/THU MORNING.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 12Z WEDNESDAY/...
AS OF 700 AM TUESDAY...VFR CONDITIONS EXPECTED THROUGH TAF PERIOD.
PTCHY SCU WILL AFFECT MAINLY KISO NEXT FEW HOURS...MOSTLY CLEAR
ELSEWHRE...THEN PERIOD OF BKN SCU CIGS AFTN INTO EVENING WITH SHRT
WV MOVING ACROSS...CLEARING OVERNIGHT. W-NW WINDS WITH GUSTS TO
AROUND 20 KT DURING THE DAY.
LONG TERM /WED THRU SAT/
AS OF 3 AM TUE...VFR WITH MOSTLY CLEAR SKIES AND A LIGHT NORTHWEST
FLOW THROUGH THE PERIOD.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 915 AM TUESDAY...GUSTY WNW WINDS CONTINUE ON THE COASTAL
WATERS AND SOUNDS WITH SEAS AS HIGH AS 7 FEET. NO CHANGES TO THE
ADVISORIES AT THIS TIME...BUT AS PORTIONS OF THE ADVISORY AREA
EXPIRE DURING THE LATE MORNING...WILL RE-EVALUATE THE ADVISORY.
LONG TERM /WED THRU SAT/
AS OF 3 AM TUE...LATEST RUN OF THE GFS AND ECMWF SHOWS THEM IN
GOOD AGREEMENT. USED A CONSENSUS BLEND FOR THE FORECAST. NORTHWEST
FLOW WILL CONTINUE OVER THE AREA. CYCLONIC FLOW AROUND DEEP LOW
FAR TO THE NORTHEAST WILL GRADUALLY GIVE WAY TO A SURFACE RIDGE
BUILDING IN FROM THE WEST THROUGH THE WEEKEND. WINDS AND SEAS
WILL SLOWLY SUBSIDE AS A RESULT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ135-
156-158.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR AMZ150-152-
154.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...HSA
AVIATION...JBM/HSA
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
633 AM EDT TUE MAR 26 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL CONTINUE TO SEND PIECES OF JET ENERGY
ACROSS THE REGION THROUGH THURSDAY. HIGH PRESSURE WILL BUILD INTO
THE AREA FOR FRIDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENT FORECAST STILL LOOKS REASONABLE. HAVE ONLY MADE MINOR
TWEAKS TO TEMPERATURES TO REFLECT CURRENT CONDITIONS.
PREVIOUS DISCUSSION...
WARM ADVECTION IS OCCURRING AT 8H THIS MORNING ON NORTHERLY WINDS.
THIS MAKES IT DIFFICULT FOR THE LAKES TO CONTRIBUTE VERY MUCH
MOISTURE TO DEPOSIT ON NORTHERN OHIO. HOWEVER THERE MAY BE SOME
MIDDLE LEVEL FLURRIES OR MAYBE EVEN SOME SPRINKLES AS WE WARM INTO
THE MIDDLE TO UPPER 30S THIS AFTERNOON.
BY AFTERNOON INTO THE EVENING IT APPEARS THERE WILL BE ANOTHER
PIECE OF JET ENERGY MOVING THROUGH THE UPPER LEVEL TROUGH. THIS
SHOULD HELP TO INCREASE THE LIFT ACROSS THE REGION WITH AN
INCREASE IN LIGHT SNOW ANTICIPATED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
AS THE WAVE PASSES LATE TONIGHT INTO WEDNESDAY MORNING WE SHOULD
SEE SLIGHTLY COOLER AIR FLOW ACROSS LAKE ERIE. THIS MAY BE JUST
ENOUGH TO GET SOME LAKE EFFECT SNOW SHOWERS GOING...ESPECIALLY
WEDNESDAY EVENING INTO THURSDAY. ACCUMULATIONS WILL BE LIGHT BUT
MAY END UP BEING AN INCH OR 2 IN A FEW LOCATIONS TONIGHT AND
UP TO 3 INCHES IN THE SNOWBELT WEDNESDAY NIGHT. SINCE THE SUN
ANGLE HAS INCREASED IT WILL BE DIFFICULT SO SEE ANY SIGNIFICANT
ACCUMULATIONS DURING THE DAY.
DIURNAL TEMPERATURES WILL NOT VARY ALL THAT MUCH THROUGH THURSDAY
WITH HIGHS GENERALLY IN THE 30S AND LOWS FROM THE MID 20S TO LOWER
30S. HIGHS MAY GET BACK INTO THE 40S FOR MOST OF THE FORECAST AREA
ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE WILL LINGER OVER THE OHIO VALLEY ON SATURDAY BEFORE
MOVING TO THE EAST COAST SATURDAY NIGHT. THE HIGH WILL BRING
SEASONAL TEMPERATURES AND DRY CONDITIONS FOR SATURDAY. TEMPERATURES
ON SUNDAY WILL BE SLIGHTLY WARMER THAN SATURDAY AS SOUTHERLY TO
SOUTHWESTERLY FLOW KICKS IN AHEAD OF AN APPROACHING COLD FRONT. THE
COLD FRONT WILL MOVE INTO THE AREA FROM THE NORTHWEST ON SUNDAY
AFTERNOON...WITH A DECENT CHANCE OF RAIN AHEAD AND ALONG THE FRONT.
PRECIPITATION WILL CONTINUE WELL INTO MONDAY AS A MOIST UPPER LEVEL
TROF LINGERS OVER THE AREA. SURFACE HIGH PRESSURE WILL MOVE INTO THE
AREA FROM THE WEST AGAIN ON TUESDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
HAD GOOD IMPROVEMENT FOR AVIATION THE PAST FEW HOURS WITH THE
IFR/MVFR EXITING WITH SOME DRYING COMING IN FROM THE NORTH. SO
QUESTION WILL BE WILL NON-VFR CONDITIONS RE-DEVELOP
OVERNIGHT/TOWARD MORNING. LATEST HRRR GUIDANCE IN PARTICULAR SHOW
THE NON VFR CEILINGS RETURNING TO THE EASTERN HALF OF THE AREA.
WITH LAMP GUIDANCE STILL SUGGESTING SOME IFR...HAVE INCLUDED THAT
IN A TEMPO FOR MFD/CAK. MAY GET SOME MVFR VBSY TO DEVELOP
TOO...VERY LOW LEVEL MOISTURE STICKS AROUND WITH ALL OF THE SNOW
ON THE GROUND. OVERALL A LOW CONFIDENCE FORECAST IN WHAT WILL
DEVELOP OVERNIGHT.
FOR TUESDAY ANOTHER TROUGH IN A SERIES WILL MOVE ACROSS NRN OH/NW
PA. THIS WILL BRING AN INCREASE IN SNOW SHOWER ACTIVITY...MOST
NOTABLY FOR THE EASTERN HALF OF THE AREA...BUT TOL/FDY MAY ALSO
SEE SOME LIGHT SNOW. THIS ARRIVES FOR THE AFTERNOON/EARLY EVENING.
.OUTLOOK...NON VFR IN -SHSN CONTINUING INTO THURSDAY.
&&
.MARINE...
HAVE ALLOWED THE SMALL CRAFT ADVISORY TO END. A COUPLE OF TROUGHS
WILL BRUSH THE LAKE...ONE THIS AFTERNOON AND THE OTHER ON WEDNESDAY
WITH SCATTERED SNOW SHOWERS. TODAY THE NORTHWEST WINDS WILL BECOME
MORE WNW AND FOR THE MOST PART STAY THAT WAY THROUGH THURSDAY WHEN
HIGH PRESSURE FINALLY BEGINS TO BUILD OVER THE REGION. WINDS COME UP
SOME ON WEDNESDAY...BUT THIS SHOULD STAY UNDER SMALL CRAFT ADV. HIGH
PRESSURE AND LIGHT/VARIABLE WINDS FOR FRIDAY AND SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...MULLEN
SHORT TERM...MULLEN
LONG TERM...YEAGER
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
359 AM EDT TUE MAR 26 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL CONTINUE TO SEND PIECES OF JET ENERGY
ACROSS THE REGION THROUGH THURSDAY. HIGH PRESSURE WILL BUILD INTO
THE AREA FOR FRIDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WARM ADVECTION IS OCCURRING AT 8H THIS MORNING ON NORTHERLY WINDS.
THIS MAKES IT DIFFICULT FOR THE LAKES TO CONTRIBUTE VERY MUCH
MOISTURE TO DEPOSIT ON NORTHERN OHIO. HOWEVER THERE MAY BE SOME
MIDDLE LEVEL FLURRIES OR MAYBE EVEN SOME SPRINKLES AS WE WARM INTO
THE MIDDLE TO UPPER 30S THIS AFTERNOON.
BY AFTERNOON INTO THE EVENING IT APPEARS THERE WILL BE ANOTHER
PIECE OF JET ENERGY MOVING THROUGH THE UPPER LEVEL TROUGH. THIS
SHOULD HELP TO INCREASE THE LIFT ACROSS THE REGION WITH AN
INCREASE IN LIGHT SNOW ANTICIPATED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
AS THE WAVE PASSES LATE TONIGHT INTO WEDNESDAY MORNING WE SHOULD
SEE SLIGHTLY COOLER AIR FLOW ACROSS LAKE ERIE. THIS MAY BE JUST
ENOUGH TO GET SOME LAKE EFFECT SNOW SHOWERS GOING...ESPECIALLY
WEDNESDAY EVENING INTO THURSDAY. ACCUMULATIONS WILL BE LIGHT BUT
MAY END UP BEING AN INCH OR 2 IN A FEW LOCATIONS TONIGHT AND
UP TO 3 INCHES IN THE SNOWBELT WEDNESDAY NIGHT. SINCE THE SUN
ANGLE HAS INCREASED IT WILL BE DIFFICULT SO SEE ANY SIGNIFICANT
ACCUMULATIONS DURING THE DAY.
DIURNAL TEMPERATURES WILL NOT VARY ALL THAT MUCH THROUGH THURSDAY
WITH HIGHS GENERALLY IN THE 30S AND LOWS FROM THE MID 20S TO LOWER
30S. HIGHS MAY GET BACK INTO THE 40S FOR MOST OF THE FORECAST AREA
ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE WILL LINGER OVER THE OHIO VALLEY ON SATURDAY BEFORE
MOVING TO THE EAST COAST SATURDAY NIGHT. THE HIGH WILL BRING
SEASONAL TEMPERATURES AND DRY CONDITIONS FOR SATURDAY. TEMPERATURES
ON SUNDAY WILL BE SLIGHTLY WARMER THAN SATURDAY AS SOUTHERLY TO
SOUTHWESTERLY FLOW KICKS IN AHEAD OF AN APPROACHING COLD FRONT. THE
COLD FRONT WILL MOVE INTO THE AREA FROM THE NORTHWEST ON SUNDAY
AFTERNOON...WITH A DECENT CHANCE OF RAIN AHEAD AND ALONG THE FRONT.
PRECIPITATION WILL CONTINUE WELL INTO MONDAY AS A MOIST UPPER LEVEL
TROF LINGERS OVER THE AREA. SURFACE HIGH PRESSURE WILL MOVE INTO THE
AREA FROM THE WEST AGAIN ON TUESDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
HAVE HAD GOOD IMPROVEMENT FOR AVIATION THE PAST FEW HOURS WITH
THE IFR/MVFR EXITING WITH SOME DRYING COMING IN FROM THE NORTH. SO
QUESTION WILL BE WILL NON-VFR CONDITIONS RE-DEVELOP
OVERNIGHT/TOWARD MORNING. LATEST HRRR GUIDANCE IN PARTICULAR SHOW
THE NON VFR CEILINGS RETURNING TO THE EASTERN HALF OF THE AREA.
WITH LAMP GUIDANCE STILL SUGGESTING SOME IFR...HAVE INCLUDED THAT
IN A TEMPO FOR MFD/CAK. MAY GET SOME MVFR VBSY TO DEVELOP
TOO...VERY LOW LEVEL MOISTURE STICKS AROUND WITH ALL OF THE SNOW
ON THE GROUND. OVERALL A LOW CONFIDENCE FORECAST IN WHAT WILL
DEVELOP OVERNIGHT.
FOR TUESDAY ANOTHER TROUGH IN A SERIES WILL MOVE ACROSS NRN OH/NW
PA. THIS WILL BRING AN INCREASE IN SNOW SHOWER ACTIVITY...MOST
NOTABLY FOR THE EASTERN HALF OF THE AREA...BUT TOL/FDY MAY ALSO
SEE SOME LIGHT SNOW. THIS ARRIVES FOR THE AFTERNOON/EARLY EVENING.
.OUTLOOK...NON VFR IN -SHSN CONTINUING INTO THURSDAY.
&&
.MARINE...
HAVE ALLOWED THE SMALL CRAFT ADVISORY TO END. A COUPLE OF TROUGHS
WILL BRUSH THE LAKE...ONE THIS AFTERNOON AND THE OTHER ON WEDNESDAY
WITH SCATTERED SNOW SHOWERS. TODAY THE NORTHWEST WINDS WILL BECOME
MORE WNW AND FOR THE MOST PART STAY THAT WAY THROUGH THURSDAY WHEN
HIGH PRESSURE FINALLY BEGINS TO BUILD OVER THE REGION. WINDS COME UP
SOME ON WEDNESDAY...BUT THIS SHOULD STAY UNDER SMALL CRAFT ADV. HIGH
PRESSURE AND LIGHT/VARIABLE WINDS FOR FRIDAY AND SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
LEZ142>149.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...MULLEN
SHORT TERM...MULLEN
LONG TERM...YEAGER
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
145 AM EDT TUE MAR 26 2013
.SYNOPSIS...
THE LOW THAT WAS OVER WESTERN PENNSYLVANIA WAS WEAKENING AND THE LOW
OFF THE MID ATLANTIC COAST WAS BECOMING PREDOMINATE. AN UPPER
LEVEL TROUGH WILL LINGER ACROSS THE EASTERN GREAT LAKES THROUGH
MID WEEK. HIGH PRESSURE WILL BUILD IN BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
FLURRIES WITH AN OCCASIONAL HEAVIER SNOW SHOWER WILL CONTINUE
ACROSS PORTIONS OF THE AREA THROUGH THE REMAINDER OF THE NIGHT.
THE BETTER CHANCES OF SEEING LIGHT SNOW WILL BE ACROSS THE WESTERN
COUNTY WARNING AREA...INCLUDING THE CENTRAL HIGHLANDS. STILL CANT
COMPLETELY RULE OUT SOME PATCHY FREEZING DRIZZLE BUT BELIEVE
CHANCES ARE TOO LOW TO MENTION.
PREVIOUS DISCUSSION...
THE SNOW WAS ON THE DECREASE AS THE SURFACE LOW OVER WESTERN PA
WAS WEAKENING. GOING WITH LIGHT SNOW OR SNOW SHOWERS TRANSITIONING
TO FLURRIES. LITTLE ADDITIONAL SNOW ACCUMULATION. A LITTLE CONCERN
ABOUT SOME DRIZZLE OR FREEZING DRIZZLE MIXING IN AS SOME DRYING
OCCURS ALOFT. AT THIS TIME IT SEEMS LIKE IT SHOULD BE MAINLY SNOW
OR FLURRIES. ADJUSTED THE LOWS UP A LITTLE BECAUSE OF MOSTLY
CLOUDY SKIES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
LONGWAVE TROUGH WILL SET UP OVER THE AREA FOR NEXT SEVERAL DAYS
SETTING UP A SITUATION OF ON AGAIN...OFF AGAIN INTERMITTENT SNOW
SHOWERS THROUGH THURSDAY AS SERIES OF SURFACE TROUGHS SWING ACROSS
THE AREA. MODELS INDICATE FIRST TROUGH SHOULD SWING ACROSS THE AREA
TOMORROW AFTERNOON. WENT WITH LIKELY POPS...BUT LOW ACCUMULATIONS.
THE 850 MB TEMPS DIP TO MINUS 10 C TUESDAY SO WILL ALSO HAVE SOME
LAKE ENHANCED SNOW. WITH WINDS SHIFTING FROM NW TO W AND BACK AGAIN
EXPECT MOST OF THE LIGHT SNOW WILL BE CONFINED ACROSS EASTERN HALF
OF THE FORECAST AREA. EXPECT TEMPERATURES TO REMAIN BELOW NORMAL
THROUGH THE PERIOD WITH HIGHS IN THE 30S AND LOWS IN THE 20S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LONG TERM BEGINS ON FRIDAY WITH MODELS IS GENERAL AGREEMENT
SHOWING A BROAD SURFACE HIGH ACROSS THE OHIO VALLEY AND GREAT LAKES
AND WEAK LOW PRESSURE IN THE SOUTHERN PLAINS. ALOFT...NORTHWEST
FLOW WILL BE ACROSS THE AREA. SATURDAY MODELS CONTINUE TO SHOW HIGH
PRESSURE ACROSS THE OHIO VALLEY HOWEVER BY EVENING THE HIGH WILL
HAVE MOVED EAST. SUNDAY MODELS SHOW THE HIGH WELL OFF THE EAST
COAST WITH AND LOW PRESSURE MOVING THROUGH CENTRAL CANADA. THIS LOW
WILL HAVE A COLD FRONT EXTENDING SOUTH THROUGH THE WESTERN LAKES
THAT WILL DROP ACROSS THE OHIO VALLEY SUNDAY NIGHT. WOULD EXPECT A
DECENT CHANCE OF SHOWERS AHEAD OF THE FRONT ACROSS THE AREA SO WILL
HAVE CHANCE POPS SUNDAY AND SUNDAY EVENING. WILL CONTINUE WITH
CHANCE POPS MONDAY WITH AN UPPER TROF AND ASSOCIATED MOISTURE
DROPPING SOUTH ACROSS THE AREA. TEMPS LOWER THAN NORMAL AT FIRST
BUT TEMPS LOOK TO BE MODERATING TO NEAR NORMAL SATURDAY AND SUNDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
HAVE HAD GOOD IMPROVEMENT FOR AVIATION THE PAST FEW HOURS WITH THE
IFR/MVFR EXITING WITH SOME DRYING COMING IN FROM THE NORTH. SO
QUESTION WILL BE WILL NON-VFR CONDITIONS RE-DEVELOP OVERNIGHT/TOWARD
MORNING. LATEST HRRR GUIDANCE IN PARTICULAR SHOW THE NON VFR
CEILINGS RETURNING TO THE EASTERN HALF OF THE AREA. WITH LAMP GUIDANCE
STILL SUGGESTING SOME IFR...HAVE INCLUDED THAT IN A TEMPO FOR
MFD/CAK. MAY GET SOME MVFR VBSY TO DEVELOP TOO...VERY LOW LEVEL
MOISTURE STICKS AROUND WITH ALL OF THE SNOW ON THE GROUND. OVERALL
A LOW CONFIDENCE FORECAST IN WHAT WILL DEVELOP OVERNIGHT.
FOR TUESDAY ANOTHER TROUGH IN A SERIES WILL MOVE ACROSS NRN OH/NW
PA. THIS WILL BRING AN INCREASE IN SNOW SHOWER ACTIVITY...MOST
NOTABLY FOR THE EASTERN HALF OF THE AREA...BUT TOL/FDY MAY ALSO
SEE SOME LIGHT SNOW. THIS ARRIVES FOR THE AFTERNOON/EARLY EVENING.
.OUTLOOK...NON VFR IN -SHSN CONTINUING INTO THURSDAY.
&&
.MARINE...
THE NORTHEAST WIND WILL BACK TO NORTHWEST AND GRADUALLY DIMINISH
TONIGHT AS LOW PRESSURE MOVES OFF THE EAST COAST. THE SMALL CRAFT
ADVISORY IS TO EXPIRE AT 4 AM AND THAT MAY WORK OUT. THERE WILL BE A
SLIGHTLY LULL IN THE NORTHWEST WIND ON TUESDAY...THEN THE NORTHWEST
WIND MAY PICK BACK UP JUST ENOUGH ON WEDNESDAY INTO THURSDAY AS A
COUPLE OF TROUGHS SWING ACROSS THE EASTERN GREAT LAKES TO REQUIRE
ANOTHER SMALL CRAFT ADVISORY ON THE EAST HALF OF THE LAKE. HIGH
PRESSURE WILL BUILD OVER THE LAKE BY THE WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
LEZ142>149.
&&
$$
SYNOPSIS...DJB
NEAR TERM...KIELTYKA/MULLEN
SHORT TERM...DJB
LONG TERM...TK
AVIATION...OUDEMAN
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
622 PM CDT WED MAR 27 2013
.UPDATE...
ISSUED AT 519 PM CDT WED MAR 27 2013
UPDATED GRIDS TO ADD PATCHY FOG TO REST OF CWA OVERNIGHT INSTEAD
OF JUST THE NORTH. WITH LOW LEVEL SOUTHEAST FLOW AND NON MIXED AIR
OVER IOWA...COULD SEE PATCHY FOG FORM. ALSO NEED TO WATCH TONIGHT
FOR STRATUS DEVELOPMENT ESPECIALLY ACROSS THE EASTERN CWA. IF THIS
DOES HAPPEN...HIGHS COULD BE 5 TO 10 DEGREES COOLER THAN EXPECTED
OVER THE EAST ON THURSDAY AS STRATUS WOULD TAKE TIME TO BURN OFF.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 341 PM CDT WED MAR 27 2013
LOW LEVEL SOUTHEASTERLY FLOW WILL WEAKEN A BIT TONIGHT AND THAT WITH
COOLING WILL ALLOW SURFACE WINDS TO GO LIGHTER AS THE NIGHT GOES ON.
STILL...SLOW LOW LEVEL MOISTURE INCREASE IS MARGINAL AS FAR AS FOG
PRODUCING WITH THE COOLING. WILL KEEP PATCHY FOG MAINLY NORTH
TONIGHT. AREAS OF FOG MIGHT BE TECHNICALLY BETTER GIVE THE LIGHT BUT
STEADY FLOW...BUT LIKE TO KEEP THE MENTION MINIMAL FOR NOW AS
VISIBILITIES MAY NOT GET VERY LOW. LESS CLOUD INCREASE IS EXPECTED
THAN WE WERE THINKING EARLIER WITH A LITTLE MID CLOUD DEVELOPMENT
BACKING INTO THE EASTERN EDGE OF THE AREA. THINK SUGGESTION OF MODELS
OF STRATUS ESPECIALLY WEST IS OVERDONE AS USUAL...IN FACT THE
MOISTURE INDICATED IS LESS DEEP THAN WHAT WAS FORECAST FOR THE
SOUTHWEST CORNER LAST NIGHT AND NOTHING DEVELOPED.
THERE WILL BE A MID CLOUD INCREASE BEGINNING AROUND OR A LITTLE
BEFORE DAYBREAK AS WEAK SHORT WAVE MOVES TOWARD THE SOUTHWEST CORNER
OF THE AREA. THESE MIDDLE CLOUDS SHOULD INCREASE FROM WEST TO EAST
THURSDAY...ESPECIALLY ACROSS OUR SOUTHERN FORECAST AREA...BUT THIS
FEATURE TO MIGHT BE OVERDONE GIVEN THAT IT IS SUCH SMALL SCALE...SO
WILL NOT MAKE IT TOO CLOUDY FOR THURSDAY. TEMPERATURES WE HAVE BEEN
GOING FOR LOOK GOOD FOR TONIGHT. THURSDAY HIGHS ARE AGAIN LIKELY TO
BE ABOVE GUIDANCE AND AM GOING ACCORDINGLY...THOUGH NOT QUITE AS WARM
AS WE WOULD WITH A SKY AS CLEAR AS TODAY....ESPECIALLY SOUTH WHERE
THE INCREASING CLOUD COVER SHOULD BE THE THICKEST. YES...THERE WILL
LIKELY BE A FEW LIGHT MID LEVEL SHOWERS WITH THIS WEAK SYSTEM...BUT
THE KEY WORD IS WEAK...AND WITH THE AIR STILL PROGGED TO BE PRETTY
DRY BELOW MID LEVELS...AM ELECTING FOR NOW TO WITHHOLD SHOWER
MENTION.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 341 PM CDT WED MAR 27 2013
WARMING TREND CONTINUES INTO FRIDAY WITH SOUTHERLY FLOW AHEAD OF AN
APROACHING COLD FRONT AND STRONG LOW/MID LEVEL TEMPERATURE
ADVECTION. 925 MB TEMPERATURES COULD EVEN APROACH +10C IN SOUTH
CENTRAL SD BY FRIDAY EVENING. DESPITE SOME FILTERED SUNSHINE...HIGHS
SHOULD STILL REACH THE 50S FOR ALL BUT THE FAR NORTHERN FORECAST AREA
AND MAY BE NEAR 60 IN THE MISSOURI VALLEY. THE FRONT DROPS INTO OUR
FAR WESTERN COUNTIES AROUND MIDNIGHT AND WILL GRADUALLY TRACK
SOUTHEAST THROUGH THE FORECAST AREA INTO SATURDAY. THE SOUTHERLY
FETCH WILL TAP INTO INCREASED MOISTURE INTO FRIDAY NIGHT...ALLOWING
SCATTERED RAIN SHOWERS TO DEVELOP AHEAD OF THE FRONT IN OUR FAR WEST
ON FRIDAY EVENING. THE SHOWERS WILL BECOME MORE WIDESPREAD AS THEY
MOVE INTO THE CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA
LATE FRIDAY NIGHT THROUGH SATURDAY. ABOVE FREEZING TEMPERATURES INTO
THE MID LEVELS WILL KEEP PRECIPITATION ENTIRELY RAINFALL...AND THERE
COULD EVEN BE ENOUGH WEAK INSTABILITY FOR SOME ISOLATED
THUNDERSTORMS AS WELL...MAINLY ACROSS THE SOUTH.
COOLER NORTHWEST FLOW SETTLES IN FOR THE EARLY PART OF NEXT WEEK
WITH A REINFORNCING SHOT OF COLD AIR ARRIVING SUNDAY NIGHT. CLOUDS
WILL STICK AROUND SUNDAY AND SUNDAY NIGHT...HOWEVER MODELS DO AGREE
ON KEEPING THE THERMAL BOUNDARY AND ANY WEAK WAVES SOUTH OF THE
AREA. AS A RESULT...THE BULK OF THE FORECAST AREA SHOULD REMAIN DRY
WITH PERHAPS SOME SCATTERED FLURRIES ON SUNDAY NIGHT. WITH CANADIAN
HIGH PRESSURE SINKING SOUTHWARD ON MONDAY...HIGHS WILL RETURN TO WELL
BELOW NORMAL READINGS IN THE 30S...FOLLOWED BY LOWS MAINLY IN THE
TEENS ON MONDAY NIGHT. WE SEE SOME MODERATION TUESDAY AND
WEDNESDAY...BUT CONDITIONS STILL LOOK NEAR OR BELOW NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 619 PM CDT WED MAR 27 2013
BOTH HRRR AND RAP ARE MUCH DRIER THAN THE NAM OR GFS. THE NET
RESULT IS TO REMOVE FOG FROM FORECAST FOR BOTH KFSD AND KSUX
TERMINALS. WITH LINGERING SNOW PACK NEAR KHON...LOW LEVEL MOISTURE
MAY BE MORE ABUNDANT...SO LEFT MENTION IN THE FORECAST FOR NOW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...25
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
505 PM MDT WED MAR 27 2013
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 221 PM MDT WED MAR 27 2013
20Z UPPER LEVEL ANALYSIS SHOWS A RIDGE OVER THE WESTERN CONUS MOVING
INTO THE NORTHERN PLAINS. SKIES ACROSS THE AREA ARE MOSTLY SUNNY.
WINDS ARE LIGHT AND VARIABLE...AND TEMPS ARE CLIMBING INTO THE 40S
AND LOWER 50S.
LIGHT WINDS AND PARTLY CLOUDY SKIES ARE EXPECTED TONIGHT...WITH LOWS
IN THE 20S. THE NAM IS SHOWING THE POSSIBILITY FOR SOME PATCHY
SHALLOW FOG ACROSS PARTS OF WESTERN SOUTH DAKOTA BY EARLY THURSDAY
MORNING...BUT THE RAP AND GFS ARE DRIER. NOT CONVINCED ANYTHING WILL
DEVELOP...SO WILL LEAVE IT OUT OF THE FORECAST FOR NOW.
AS THE RIDGE PROGRESSES EASTWARD...TEMPS WILL WARM INTO LOWER 50S TO
LOWER 60S ON THURSDAY. WINDS WILL BE LIGHT AND EASTERLY. A SMALL
AMOUNT OF CAPE IS EXPECTED TO DEVELOP OVER THE BLACK HILLS IN THE
LATE AFTERNOON...ALONG AN AREA OF FRONTOGENESIS AND MOISTURE
CONVERGENCE. THEREFORE...THE HILLS COULD SEE SOME LIGHT RAIN SHOWERS
THURSDAY AFTERNOON. THE POSSIBILITY FOR FOG LOOKS A LITTLE BETTER
EARLY FRIDAY MORNING WITH HIGHER RH PREDICTED...BUT WILL LET LATER
SHIFTS DECIDE ON WHETHER TO ADD IT.
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 221 PM MDT WED MAR 27 2013
RIDGE TO THE WEST WILL WEAKEN BY THE WEEKEND AS UPPER
LOW SLIDES SLOWLY SOUTHEAST ACROSS SOUTH CENTRAL CANADA. CYCLONIC
FLOW AROUND THE LOW WILL BRING AN UPPER LEVEL DISTURBANCE THROUGH
THE AREA FRIDAY NIGHT AND SATURDAY. FRIDAY WILL BE THE MILDEST DAY
OF THE WEEK...WITH HIGH TEMPERATURES IN THE MID 50S TO MID 60S. A
FEW SHOWERS ARE POSSIBLE OVER THE BLACK HILLS FRIDAY AFTERNOON AS
THE DISTURBANCE APPROACHES. WITH SOME WEAK INSTABILITY IN
PLACE...WOULD NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS LATE
FRIDAY INTO FRIDAY EVENING FROM THE BLACK HILLS AREA INTO SOUTHERN
SD. OTHERWISE...WILL KEEP CHANCE FOR MOSTLY RAIN SHOWERS...WITH LATE
NIGHT/EARLY MORNING SNOW SHOWERS POSSIBLE OVER NORTHERN AND WESTERN
PORTIONS OF THE CWA.
BEYOND SATURDAY...THE FORECAST REMAINS UNCERTAIN WITH AN UPPER LOW
MOVING EAST ACROSS THE SOUTHWESTERN CONUS AND A STRONGER UPPER LOW
ACROSS CENTRAL CANADA BRINGING DEEP NORTHWEST FLOW ACROSS THE
REGION. ADDITIONAL WEAKER DISTURBANCES IN THE NORTHWESTERLY FLOW
WILL MOVE ACROSS THE REGION THROUGH SUNDAY...SO WILL KEEP SOME
SLIGHT CHANCES FOR SHOWERS ACROSS THE CWA. DRIER CONDITIONS ARE
EXPECTED FOR THE EARLY WORK WEEK AS A COLD CANADIAN AIRMASS PUSHES
INTO THE NORTHERN PLAINS. HAVE DROPPED TEMPS FOR THIS PERIOD...BUT
MAY NEED TO BE DROPPED FURTHER IF TRENDS CONTINUE TOWARD COLDER AIR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 504 PM MDT WED MAR 27 2013
VFR CONDITIONS ARE EXPECTED THROUGH THURSDAY AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...POJORLIE
LONG TERM...13
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
439 AM CDT TUE MAR 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 439 AM CDT TUE MAR 26 2013
PATCHES OF STRATUS DRIFTING SOUTHWARD THROUGH THE CENTRAL PORTIONS
OF THE CWA AT THIS TIME. WILL CARRY SOME OF THIS ALONG I-29 CORRIDOR
INTO THE EARLY MORNING HOURS...BUT EXPECT THAT IT WILL GRADUALLY
DIMINISH AFTER 15Z AS SUGGESTED BY LOW LEVEL RH FIELDS ON LATEST
RAP. THEREAFTER SHOULD SEE FAIR AMOUNT OF SUN TODAY...THOUGH SOME
LINGERING LOW LEVEL MOISTURE COULD LEAD TO SCATTERED AFTERNOON
CU. LIMITED MIXING WITHIN SURFACE RIDGE AXIS WILL KEEP TEMPS QUITE
COOL AGAIN...WITH EXPECTED HIGHS FROM UPPER 20S NORTHEAST TO UPPER
30S FAR SOUTHWEST.
ANY CU SHOULD DIMINISH THIS EVENING...AND EXPECT CENTRAL/EASTERN
PARTS OF THE CWA TO REMAIN CLEAR/PARTLY CLOUDY THROUGH THE NIGHT.
DIFFERENT STORY ACROSS THE WEST HOWEVER...AS BOTH NAM/GFS INDICATE
DEVELOPMENT OF WIDESPREAD STRATUS AND/OR FOG WEST OF THE MISSOURI
RIVER IN UPSLOPE EASTERLY FLOW TOWARD 06Z...THEN EXPANDING INTO OUR
FAR WEST AFTER 09Z. WEAK LIFT IN/JUST ABOVE THE STRATUS LAYER ALSO
INDICATED IN WEAK WARM ADVECTION. UNFORTUNATELY NO SIGN OF MID LEVEL
MOISTURE TO SEED THE STRATUS WITH ICE...AND TEMPS WITHIN THE STRATUS
LAYER TOO WARM FOR ICE INTRODUCTION/INSTA-FLURRIES ON ITS OWN AS WE
SAW WITH THE STRATOCU MONDAY AFTERNOON/EVENING. THUS ANY LIGHT PRECIP
WOULD BE IN FORM OF FREEZING DRIZZLE AND HAVE ADDED THIS ALONG WITH
AREAS OF FOG TO FAR WESTERN AREAS AROUND CHAMBERLAIN LATE TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 439 AM CDT TUE MAR 26 2013
ANY STRATUS/FOG/FREEZING DRIZZLE IN THE FAR WEST EXPECTED TO CONTINUE
INTO WEDNESDAY MORNING...POSSIBLY EXPANDING INTO AREAS JUST WEST OF
THE JAMES RIVER/HURON/MITCHELL BEFORE SUBTLE LIFT DIMINISHES AND
WEAK HEATING/MIXING START TO ERODE THE STRATUS. LOW LEVEL MOISTURE
LINGERS HOWEVER...DRIFTING EAST AHEAD OF WEAK INVERTED TROUGH AXIS
WEDNESDAY INTO WEDNESDAY NIGHT. COULD THEN BE LOOKING AT FAIR AMOUNT
OF CLOUDS LATER WEDNESDAY NIGHT THROUGH THURSDAY...WHICH WOULD HOLD
TEMPS DOWN FROM FULL POTENTIAL THURSDAY GIVEN 925MB TEMPERATURES
FINALLY WARMING ABOVE ZERO. STILL EXPECT SLIGHTLY WARMER TEMPERATURES
THURSDAY...WITH HIGHS THURSDAY IN THE UPPER 30S AND 40S. MODELS STILL
TRY TO PRODUCE PATCHY LIGHT QPF THROUGH THIS PERIOD...HOWEVER GIVEN
UNCERTAINTY IN STRATUS PERSISTENCE/EXPANSION...OPTED TO NOT INCLUDE
ANY MENTION OF FOG OR DRIZZLE/FREEZING DRIZZLE AT THIS POINT. WILL BE
SOMETHING FOR FUTURE SHIFTS TO EXAMINE MORE CLOSELY THOUGH.
GREATER WARMUP EXPECTED LATE THIS WEEK...AHEAD OF UPPER WAVE AND
ASSOCIATED COLD FRONT. AS IS TYPICAL IN TRANSITIONAL PATTERNS...
MODELS HAVING TOUGH TIME AGREEING ON TIMING OF BOUNDARIES/ASSOCIATED
DEGREE OF WARMING/COOLING. GENERAL CONSENSUS SHOWS FRIDAY SHOULD BE
OUR FIRST GOOD CHANCE OF SEEING NEAR NORMAL TEMPERATURES...AND WITH
SLIGHTLY BETTER MIXING AHEAD OF INCOMING WAVE...WILL STICK WITH HIGHS
FROM THE UPPER 40S NORTHEAST TO UPPER 50S SOUTHWEST. HIGHS SATURDAY
COULD BE A BIT MORE DEPENDENT ON TIMING OF THE FRONT...WHICH HAS
TRENDED A BIT FASTER THAN WAS SEEN LAST NIGHT. GIVEN UNCERTAINTY IN
TIMING AT THIS RANGE...WILL STAY FAIRLY CLOSE TO MODEL CONSENSUS...
WHICH STILL PUTS MOST AREAS A FEW DEGREES ABOVE LATE MARCH NORMALS.
WITH FASTER TREND IN FRONTAL TIMING FROM 24 HOURS AGO...BETTER PRECIP
CHANCES WILL ADJUST ACCORDINGLY. LOOKING AT A SLIGHT CHANCE ACROSS
THE WEST/NORTH FRIDAY NIGHT...WITH BETTER CHANCE ACROSS THE SOUTHEAST
HALF OF THE CWA SATURDAY. WITH MOIST SOUTHERLY FLOW AHEAD OF BOUNDARY
FRIDAY NIGHT...TEMPERATURES SHOULD REMAIN WARM ENOUGH THAT ANY PRECIP
WOULD REMAIN LIQUID...WITH RAIN SHOWERS CONTINUING INTO SATURDAY AND
SATURDAY EVENING. MORE UNCERTAINTY IN SPEED OF COOLING LATER SATURDAY
NIGHT...BOTH SURFACE AND ALOFT...SO WILL INTRODUCE RAIN/SNOW MIX FOR
PARTS OF NORTHWEST IOWA THEN...ALTHOUGH GOOD CHANCE THAT ANY PRECIP
WOULD BE SOUTHEAST OF THE AREA BEFORE TEMPERATURES COOL ENOUGH FOR
CHANGEOVER.
SUNDAY IS DAY OF GREATEST TEMPERATURE UNCERTAINTY...AS GFS PUSHES
COLD AIR THROUGH MORE QUICKLY...WHILE ECMWF HOLDS ONTO WARMER AIR
UNTIL SECONDARY TROUGH ROTATES AROUND ONTARIO/HUDSON BAY UPPER LOW
SUNDAY NIGHT. THIS LEADING TO 20+ DEGREE DIFFERENCES BETWEEN HIGH
TEMPERATURES FORECAST BY THESE MODELS ON SUNDAY...WITH 26/00Z ECMWF
IN THE 50S-LOWER 60S FOR EASTER SUNDAY...AND CORRESPONDING GFS IN
THE 30S-LOWER 40S. 00Z CANADIAN MORE SUPPORTIVE OF SLOWER COOLING AND
THUS WILL HEDGE TOWARD THE WARMER SIDE OF CONSENSUS AVERAGE...BUT
STILL BACK TO A SHADE BELOW NORMAL...ESPECIALLY ACROSS THE NORTH.
ALTHOUGH ECMWF TIMING FOR COOLDOWN LAGS THE GFS...TEMPERATURES FOR
MONDAY HAVE TRENDED TOWARD THE COLDER SOLUTION AND WILL LIKEWISE
TREND COOLER WITH HIGHS FOR MONDAY. STILL GOING A GOOD 5-10 DEGREES
ABOVE WHAT RAW ECMWF/GFS MODEL GUIDANCE SUGGESTS FOR NOW THOUGH...
ALLOWING FOR A FEW MORE DAYS OF WAVERING ON TIMING BEFORE MODELS
REALLY LOCK ONTO PREFERRED SOLUTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1042 PM CDT MON MAR 25 2013
DESPITE NAM GUIDANCE SUGGESTING FAIRLY SUBSTANTIAL FOG THREAT FOR
KHON...HAVE KEPT MENTION OUT OF FORECAST WITH BOTH HRRR AND RAP
CONTINUING TO SUGGEST RADIATIONAL FOG WOULD REMAIN ACROSS
NORTHEAST PORTIONS OF SOUTH DAKOTA. WITH SCATTERED CLOUDS ACROSS
THE AREA...RADIATIONAL COOLING WILL BE RETARDED...THUS LIMITING
FOG POTENTIAL. LIGHT WINDS AND MOSTLY CLEAR SKIES WILL PREVAIL ON
TUESDAY WITH LIGHT EASTERLY FLOW DEVELOPING TUESDAY EVENING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JH
LONG TERM...JH
AVIATION...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1034 PM EDT WED MAR 27 2013
.SYNOPSIS...
LITTLE CHANGE IS EXPECTED IN THE WEATHER PATTERN THROUGH THURSDAY.
FRIDAY AND SATURDAY HIGH PRESSURE BUILDS INTO THE REGION THEN
MOVES OFFSHORE. A COLD FRONT WILL APPROACH THE REGION EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 1010 PM EDT WEDNESDAY...
UPSLOPE SNOW SHOWERS CONTINUE OVER PORTIONS OF SE WV...WITH
FLURRIES SCATTERED EAST TO THE BLUE RIDGE. ANOTHER VORT TRACKING
ACROSS MISSOURIS PROGGED TO IMPACT THE NC MTNS AFTER 06Z. THE
LOCAL WRF HINTS AT THIS IN TERMS OF ADJUSTING ITS HIGHER QPF FROM
SE WV BACK TOWARD THE MTN EMPIRE OF SW VA AND HIGH COUNTRY OF NC.
AFTER A LULL THIS EVENING...SHOULD SEE SNOW SHOWERS INCREASE AGAIN
OVERNIGHT IN THE MOUNTAINS OF NORTH CAROLINA. OVERALL...THE FLOW
SUGGEST SOME BANDING POSSIBLE EXTENDING INTO THE NEW RIVER VALLEY.
AMOUNTS WILL BE AN INCH OR LESS...WITH LOCALLY 2 INCHES OVER THE
TYPICAL WRN SLOPES OF GREENBRIER COUNTY WV. HAVE A SPECIAL WEATHER
STATEMENT OUT TO COVER SLICK ROADS...AND WILL ALSO BE DEALING WITH
SOME BLACK ICE ISSUES...AS TEMPS FALL BELOW FREEZING.
WINDS STAYING UP JUST ENOUGH TO KEEP TEMPS FROM DROPPING FAR BUT
STILL LOOKING AT UPPER TEENS TO LOWER 20S WV MTNS TO MID TO UPPER
20S REST OF THE MTNS AND LOWER 30S OUT EAST.
PREVIOUS VALID DISCUSSION...
WATER VAPOR LOOP SHOWED THE NEXT FEATURE MOVING SOUTH THROUGH THE
EASTERN GREAT LAKES. MODELS HAVE THIS SHORT WAVE MOVING THROUGH
EASTERN VIRGINIA ON THURSDAY MORNING.
850 MB WINDS THROUGH THE PERIOD REMAIN IN THE 20 TO 35 KNOT RANGE
FROM THE NORTHWEST. RAP GUIDANCE AND LOCAL WRF BOTH INDICATED
SOME BANDS OF SNOW SHOWERS MAY DEVELOP BEFORE MIDNIGHT TONIGHT.
HAVE ADDED MORE CLOUD COVER IN THE EAST THURSDAY MORNING...WITH
THE NEXT SHORT WAVE...OTHERWISE PERSISTENT DOWNSLOPE FLOW WILL
LIMIT COVER COVER AND SHOWERS EAST OF THE FOOTHILLS OVERNIGHT.
HOWEVER...TEMPERATURES ALOFT REMAIN COLD ENOUGH AND LAPSE RATES
DURING THE DAY ARE LARGE ENOUGH THAT MORE SCATTERED STRATOCUMULUS
WILL FORM AGAIN BY LATE THURSDAY MORNING.
STAYED ON THE COOL SIDE OF GUIDANCE FOR LOWS TONIGHT AND
ESPECIALLY HIGHS ON THURSDAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 200 PM EDT WEDNESDAY...
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE REGION WILL CONTINUE TO BE
IN A PATTERN OF NORTHWEST FLOW. HOWEVER...THE VARIOUS SHORTWAVE
TROUGHS WITHIN THE LARGER SYNOPTIC PATTERN WITH BE PROGRESSIVELY
FARTHER NORTH OF THE REGION. ALSO...THE PRESSURE GRADIENT WILL BE
BROADENING...AND THEREFORE...THE MAGNITUDE OF THE UPSLOPE WINDS WILL
BE LESS. WHILE WE WILL STILL BE FORECASTING UPSLOPE SNOW
SHOWERS/FLURRIES FOR SOUTHEAST WEST VIRGINIA...THE IMPACT WILL BE
ALSO BE DECREASING IN TIME. THE ONE CLINKER IN THIS SCENARIO IS THE
POTENTIAL FOR SOME LIGHT PRECIPITATION ACROSS THE SOUTHWEST PART OF
THE FORECAST AREA FRIDAY NIGHT. THE 12Z/8AM GFS/NAM/CANADIAN
SOLUTIONS HAVE BEEN HINTING AT A WEAK DISTURBANCE PROGRESSING
THROUGH KY/TN AND INTO SW VA/NW NC. WHILE IT HAS BEEN WEAK...IT HAS
BEEN CONSISTENT FROM MODEL RUN TO MODEL RUN. OUR CURRENT FORECAST
HAS THIS FEATURE REFLECTED LATE FRIDAY NIGHT INTO EARLY SATURDAY
MORNING TO A MINIMAL DEGREE. WE WILL SHOW AN INCREASE IN THE
POTENTIAL OF A LIGHT MIX OF WINTRY PRECIPITATION IN THIS FORECAST
PACKAGE...WHILE STILL MAINTAINING RELATIVELY LOW CHANCES.
BY SATURDAY INTO SATURDAY NIGHT...MODEL GUIDANCE IS SUGGESTING WHAT
HAS BEEN AN EXTENDED PERIOD OF NORTHWEST FLOW COMES TO AN END AS AN
UPPER LEVEL SHORTWAVE RIDGE BUILDS ACROSS THE REGION...AND THE
PREVAILING FLOW BECOMES SOUTHWEST. RIDGING OVER THE REGION WILL BE
BE BRIEF AS IT DEVELOPS AS A RESULT OF OUR NEXT SHORTWAVE TROUGH
PROGRESSING THROUGH THE CENTER OF THE COUNTRY. WITHIN THIS SOUTHWEST
FLOW WILL BE A NEW SOURCE OF MOISTURE...THE GULF OF MEXICO. WE WILL
EXPERIENCE PATCHY LIGHT RAIN AND INCREASED CLOUD COVER MOVING INTO
THE SOUTHWEST PART OF THE AREA AS EARLY AS SATURDAY EVENING.
THROUGHOUT SATURDAY NIGHT...THE PRECIPITATION WILL PROGRESS
NORTH...AND EXPAND IN COVERAGE...HOWEVER...AMOUNTS ARE EXPECTED TO
BE ON THE LIGHT SIDE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 1245 PM EDT WEDNESDAY...
ON SUNDAY...THE TREND WILL CONTINUE FOR INCREASING CHANCES OF RAIN
THROUGHOUT THE MORNING AND AFTERNOON...WITH HEAVIER SHOWERS POSSIBLE
ACROSS THE MOUNTAINS DURING THE AFTERNOON THANKS TO THE APPROACH OF
A COLD FRONT. TEMPERATURES WILL CONTINUE TO TREND MILDER. LOWS
SUNDAY MORNING WILL BE IN THE LOWER 40S ACROSS MUCH OF THE
REGION...WITH HIGHER RIDGE TOPS OF SE WV IN THE MID TO UPPER 30S. ON
SUNDAY...LOW TO MID 50S FOR HIGHS ARE EXPECTED IN THE
MOUNTAINS...WITH UPPER 50S TO AROUND 60 EAST OF THE BLUE RIDGE.
SUNDAY NIGHT...THE COLD FRONT CROSSES THE REGION WITH ITS ASSOCIATED
PRECIPITATION...AND THEN COLDER AIR STARTS TO RETURN. BY LATE SUNDAY
NIGHT...ENOUGH COLD AIR MAY BRING SOME SNOW SHOWERS MIXED WITH THE
RAIN SHOWERS TO WESTERN GREENBRIER CO WV.
MONDAY THROUGH WEDNESDAY...THE REGION REMAINS WITH A NORTHWEST FLOW
PATTERN DURING THIS PERIOD. THIS WILL PUT US BACK IN AN UPSLOPE
PATTERN WITH A MIX OF RAIN AND SNOW SHOWERS ACROSS SE WV. THE GFS IS
SUGGESTING TUESDAY MAY BE A DAY WITH PRECIPITATION ACROSS A WIDER
SWATH OF THE AREA IN ADDITION TO THE UPSLOPE PRECIPITATION. ITS
SOLUTION BRINGS A SOUTHERN STREAM SYSTEM ALONG THE GULF COAST STATES
AND THEN NORTH ALONG THE COAST ALONG THE FRONTAL BOUNDARY THAT WOULD
HAVE CROSS OUR REGION ON SUNDAY. OUR FORECAST WILL OFFER SOME
CREDENCE TO THIS POTENTIAL...BUT ONLY WITH A SLIGHT CHANCE OF
RAIN SHOWERS IN THE EAST.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
AS OF 720 PM EDT WEDNESDAY...
SNOW SHOWERS AND FLURRIES WILL BE PERSISTENT ACROSS THE BLF/LWB
AND SOMETIMES BCB TERMINALS THROUGH TONIGHT. AT LEAST ENOUGH
CONFIDENCE TO HAVE BLF DROPPING TO IFR VSBYS AROUND 08Z. WILL KEEP
MVFR CIGS IN THE WEST WHILE THE EAST WILL STAY VFR WITH SCT V BKN
4-6KFT.
WINDS WILL BE SETTLING DOWN EAST OF THE MOUNTAINS TONIGHT WHILE
STAYING AROUND 10 KNOTS IN THE MTNS WITH PERHAPS AN OCCASIONAL
GUST TO 20 KNOTS.
AFTER SUNRISE THE WINDS PICK BACK UP WITH GUSTS 20 TO 30 KNOTS.
EXPECT VFR FOR MOST OF THE AREA...WHILE LIGHT SNOW SHOWERS
ACCOMPANIED BY LOWER CEILINGS WILL REMAIN IN THE WEST
VIRGINIA...BUT SHOULD SEE IMPROVING CIGS AFTER 15Z.
BY FRIDAY THE LOW LEVEL MOISTURE ERODES AND PUTS AN END TO THE
UPSLOPE SNOW SHOWERS ACROSS THE MOUNTAINS AND CLEARS OUT THE LOW
LEVEL CU. SURFACE HIGH PRESSURE BUILDS IN FOR FRIDAY AND SATURDAY
RESULTING IN LIGHTER WINDS AND VFR CONDITIONS.
CLOUDS INCREASE AGAIN AHEAD OF ANOTHER FRONT ON SATURDAY NIGHT.
DEEPER MOISTURE ALONG WITH THE THREAT OF SHOWERS WILL HOLD OFF
UNTIL SUNDAY WHEN MVFR CEILINGS AND VISIBILITIES OR WORSE MAY
DEVELOP. A STRONG COLD FRONT IS EXPECTED TO CROSS THROUGH THE
REGION..RETURNING BELOW NORMAL TEMPERATURES AND MOUNTAIN SNOW
SHOWERS ON MONDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...DS
LONG TERM...DS
AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
737 PM EDT WED MAR 27 2013
.SYNOPSIS...
LITTLE CHANGE IS EXPECTED IN THE WEATHER PATTERN THROUGH THURSDAY.
FRIDAY AND SATURDAY HIGH PRESSURE BUILDS INTO THE REGION THEN
MOVES OFFSHORE. A COLD FRONT WILL APPROACH THE REGION EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 720 PM EDT WEDNESDAY...
THE UPSLOPE COMBINED WITH SEVERAL SHORTWAVES WILL KEEP SNOW
SHOWERS GOING OVER THE WV MOUNTAINS INTO PORTIONS OF SW VA AND NW
NC. NOT REALLY SEEING MUCH OF A LULL EXCEPT IN NW NC WHERE SKIES
WERE CLEARING SOME...BUT NEXT WAVE OVER KY ARRIVES SOON AND SHOULD
BRING ANOTHER ROUND OF SNOW SHOWERS AND FLURRIES BACK TO THE HIGH
COUNTRY. AT THE MOMENT SNOWFALL TOTALS THROUGH THE NIGHT SHOULD BE
LESS THAN AN INCH...EXCEPT HIGHER OVER WRN GREENBRIER. AS
USUAL...SOME BANDING POSSIBLE AND WE COULD SEE SNOW SHOWERS
STREAKING EWD TOWARD THE NEW RIVER VALLEY AND ROANOKE AREA
TONIGHT.
PREVIOUS VALID DISCUSSION...
WATER VAPOR LOOP SHOWED THE NEXT FEATURE MOVING SOUTH THROUGH THE
EASTERN GREAT LAKES. MODELS HAVE THIS SHORT WAVE MOVING THROUGH
EASTERN VIRGINIA ON THURSDAY MORNING.
850 MB WINDS THROUGH THE PERIOD REMAIN IN THE 20 TO 35 KNOT RANGE
FROM THE NORTHWEST. RAP GUIDANCE AND LOCAL WRF BOTH INDICATED
SOME BANDS OF SNOW SHOWERS MAY DEVELOP BEFORE MIDNIGHT TONIGHT.
HAVE ADDED MORE CLOUD COVER IN THE EAST THURSDAY MORNING...WITH
THE NEXT SHORT WAVE...OTHERWISE PERSISTENT DOWNSLOPE FLOW WILL
LIMIT COVER COVER AND SHOWERS EAST OF THE FOOTHILLS OVERNIGHT.
HOWEVER...TEMPERATURES ALOFT REMAIN COLD ENOUGH AND LAPSE RATES
DURING THE DAY ARE LARGE ENOUGH THAT MORE SCATTERED STRATOCUMULUS
WILL FORM AGAIN BY LATE THURSDAY MORNING.
STAYED ON THE COOL SIDE OF GUIDANCE FOR LOWS TONIGHT AND
ESPECIALLY HIGHS ON THURSDAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 200 PM EDT WEDNESDAY...
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE REGION WILL CONTINUE TO BE
IN A PATTERN OF NORTHWEST FLOW. HOWEVER...THE VARIOUS SHORTWAVE
TROUGHS WITHIN THE LARGER SYNOPTIC PATTERN WITH BE PROGRESSIVELY
FARTHER NORTH OF THE REGION. ALSO...THE PRESSURE GRADIENT WILL BE
BROADENING...AND THEREFORE...THE MAGNITUDE OF THE UPSLOPE WINDS WILL
BE LESS. WHILE WE WILL STILL BE FORECASTING UPSLOPE SNOW
SHOWERS/FLURRIES FOR SOUTHEAST WEST VIRGINIA...THE IMPACT WILL BE
ALSO BE DECREASING IN TIME. THE ONE CLINKER IN THIS SCENARIO IS THE
POTENTIAL FOR SOME LIGHT PRECIPITATION ACROSS THE SOUTHWEST PART OF
THE FORECAST AREA FRIDAY NIGHT. THE 12Z/8AM GFS/NAM/CANADIAN
SOLUTIONS HAVE BEEN HINTING AT A WEAK DISTURBANCE PROGRESSING
THROUGH KY/TN AND INTO SW VA/NW NC. WHILE IT HAS BEEN WEAK...IT HAS
BEEN CONSISTENT FROM MODEL RUN TO MODEL RUN. OUR CURRENT FORECAST
HAS THIS FEATURE REFLECTED LATE FRIDAY NIGHT INTO EARLY SATURDAY
MORNING TO A MINIMAL DEGREE. WE WILL SHOW AN INCREASE IN THE
POTENTIAL OF A LIGHT MIX OF WINTRY PRECIPITATION IN THIS FORECAST
PACKAGE...WHILE STILL MAINTAINING RELATIVELY LOW CHANCES.
BY SATURDAY INTO SATURDAY NIGHT...MODEL GUIDANCE IS SUGGESTING WHAT
HAS BEEN AN EXTENDED PERIOD OF NORTHWEST FLOW COMES TO AN END AS AN
UPPER LEVEL SHORTWAVE RIDGE BUILDS ACROSS THE REGION...AND THE
PREVAILING FLOW BECOMES SOUTHWEST. RIDGING OVER THE REGION WILL BE
BE BRIEF AS IT DEVELOPS AS A RESULT OF OUR NEXT SHORTWAVE TROUGH
PROGRESSING THROUGH THE CENTER OF THE COUNTRY. WITHIN THIS SOUTHWEST
FLOW WILL BE A NEW SOURCE OF MOISTURE...THE GULF OF MEXICO. WE WILL
EXPERIENCE PATCHY LIGHT RAIN AND INCREASED CLOUD COVER MOVING INTO
THE SOUTHWEST PART OF THE AREA AS EARLY AS SATURDAY EVENING.
THROUGHOUT SATURDAY NIGHT...THE PRECIPITATION WILL PROGRESS
NORTH...AND EXPAND IN COVERAGE...HOWEVER...AMOUNTS ARE EXPECTED TO
BE ON THE LIGHT SIDE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 1245 PM EDT WEDNESDAY...
ON SUNDAY...THE TREND WILL CONTINUE FOR INCREASING CHANCES OF RAIN
THROUGHOUT THE MORNING AND AFTERNOON...WITH HEAVIER SHOWERS POSSIBLE
ACROSS THE MOUNTAINS DURING THE AFTERNOON THANKS TO THE APPROACH OF
A COLD FRONT. TEMPERATURES WILL CONTINUE TO TREND MILDER. LOWS
SUNDAY MORNING WILL BE IN THE LOWER 40S ACROSS MUCH OF THE
REGION...WITH HIGHER RIDGE TOPS OF SE WV IN THE MID TO UPPER 30S. ON
SUNDAY...LOW TO MID 50S FOR HIGHS ARE EXPECTED IN THE
MOUNTAINS...WITH UPPER 50S TO AROUND 60 EAST OF THE BLUE RIDGE.
SUNDAY NIGHT...THE COLD FRONT CROSSES THE REGION WITH ITS ASSOCIATED
PRECIPITATION...AND THEN COLDER AIR STARTS TO RETURN. BY LATE SUNDAY
NIGHT...ENOUGH COLD AIR MAY BRING SOME SNOW SHOWERS MIXED WITH THE
RAIN SHOWERS TO WESTERN GREENBRIER CO WV.
MONDAY THROUGH WEDNESDAY...THE REGION REMAINS WITH A NORTHWEST FLOW
PATTERN DURING THIS PERIOD. THIS WILL PUT US BACK IN AN UPSLOPE
PATTERN WITH A MIX OF RAIN AND SNOW SHOWERS ACROSS SE WV. THE GFS IS
SUGGESTING TUESDAY MAY BE A DAY WITH PRECIPITATION ACROSS A WIDER
SWATH OF THE AREA IN ADDITION TO THE UPSLOPE PRECIPITATION. ITS
SOLUTION BRINGS A SOUTHERN STREAM SYSTEM ALONG THE GULF COAST STATES
AND THEN NORTH ALONG THE COAST ALONG THE FRONTAL BOUNDARY THAT WOULD
HAVE CROSS OUR REGION ON SUNDAY. OUR FORECAST WILL OFFER SOME
CREDENCE TO THIS POTENTIAL...BUT ONLY WITH A SLIGHT CHANCE OF
RAIN SHOWERS IN THE EAST.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 720 PM EDT WEDNESDAY...
SNOW SHOWERS AND FLURRIES WILL BE PERSISTENT ACROSS THE BLF/LWB
AND SOMETIMES BCB TERMINALS THROUGH TONIGHT. AT LEAST ENOUGH
CONFIDENCE TO HAVE BLF DROPPING TO IFR VSBYS AROUND 08Z. WILL KEEP
MVFR CIGS IN THE WEST WHILE THE EAST WILL STAY VFR WITH SCT V BKN
4-6KFT.
WINDS WILL BE SETTLING DOWN EAST OF THE MOUNTAINS TONIGHT WHILE
STAYING AROUND 10 KNOTS IN THE MTNS WITH PERHAPS AN OCCASIONAL
GUST TO 20 KNOTS.
AFTER SUNRISE THE WINDS PICK BACK UP WITH GUSTS 20 TO 30 KNOTS.
EXPECT VFR FOR MOST OF THE AREA...WHILE LIGHT SNOW SHOWERS
ACCOMPANIED BY LOWER CEILINGS WILL REMAIN IN THE WEST
VIRGINIA...BUT SHOULD SEE IMPROVING CIGS AFTER 15Z.
BY FRIDAY THE LOW LEVEL MOISTURE ERODES AND PUTS AN END TO THE
UPSLOPE SNOW SHOWERS ACROSS THE MOUNTAINS AND CLEARS OUT THE LOW
LEVEL CU. SURFACE HIGH PRESSURE BUILDS IN FOR FRIDAY AND SATURDAY
RESULTING IN LIGHTER WINDS AND VFR CONDITIONS.
CLOUDS INCREASE AGAIN AHEAD OF ANOTHER FRONT ON SATURDAY NIGHT.
DEEPER MOISTURE ALONG WITH THE THREAT OF SHOWERS WILL HOLD OFF
UNTIL SUNDAY WHEN MVFR CEILINGS AND VISIBILITIES OR WORSE MAY
DEVELOP. A STRONG COLD FRONT IS EXPECTED TO CROSS THROUGH THE
REGION..RETURNING BELOW NORMAL TEMPERATURES AND MOUNTAIN SNOW
SHOWERS ON MONDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...DS
LONG TERM...DS
AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS SPOKANE WA
424 PM PDT Wed Mar 27 2013
.SYNOPSIS...
A low pressure system off the coast of Washington will bring
clouds and increasing chances for rain showers to the Inland
Northwest tonight through Friday. Temperatures will be mild for the
next week. A drying trend is expected Saturday through the middle
of next week. Some of the warmest weather so far this spring is
expected Saturday through Tuesday.
&&
.DISCUSSION...
Tonight: We will be watching the decaying upper low currently off
the Washington coast. It is expected to drift toward the Olympic
Peninsula by sunrise. The mid level moisture drawn northward by
this shearing upper low will be working to overcome a wedge drier
air centered over north central and northeast Washington. Surface
dewpoints this afternoon around Omak and Colville have remained in
the mid to upper 20s. Richer boundary layer moisture resides over
the lower Columbia Basin, around the vicinity of the Blue
Mountains, and over the Palouse. The RUC model analysis suggests
surface based CAPE approaching 150 J/KG around Walla Walla,
Pomeroy and Pullman. Synoptic scale forcing is quite weak over
northeast Oregon and southeast Washington, so afternoon heating
over the high terrain will have to be the trigger for any
thunderstorm initiation. A slight chance of thunderstorms prior to
8 PM has been retained around Winchester, Pomeroy, Lewiston and
southern Shoshone county. From mid-evening through the sunrise,
low chances of high based showers will spread from south to north
with the axis of the mid-level trough associated with the upper
low pivoting toward the Olympic Peninsula.
Thursday and Thursday Night: Showers and thunderstorms will likely
peak in the mid to late afternoon hours on Thursday, and for most
of the Inland Northwest, Thursday afternoon will be the best
chance for precipitation for the next week. Surface dewpoints in
the upper 30s and low 40s should be sufficient for scattered
convective development. Again the atmosphere will not provide a
strong synoptic scale trigger for showers and thunderstorms.
However, the models do suggest that a weak wave ejecting from low
pressure off the coast of northern California may reach northern
Oregon and southern Washington by Thursday afternoon. This upper
wave will probably not be strong enough to perpetuate convection
much past early evening. Look for showers and thunderstorms to
decay quickly Thursday evening. /GKoch
Friday through Sunday...High pressure anchored just west of the
Washington coast will keep much of the weather on the warm and dry
side through the weekend. A departing shortwave will continue to
drag a cold front southeast on Friday, with lingering
precipitation over southeast Washington and the central and
southern Idaho panhandle. Model soundings show just enough
instability for isolated thunderstorms over the southern Idaho
panhandle, with cold enough temperatures in the cloud layer for a
lightning strike. This doesn`t look like a widespread thunder
event, with even the total precipitation looking on the meager
side. Snow levels are also going to be quite high, so travel
problems over the passes do not look like it will be a problem. By
Saturday, precipitation chances trend toward zero,
with temperatures looking to be above normal, and in some cases
five to ten degrees above normal. The lack of cloud cover and the
continued influence of the upper level high pressure should allow
for good cooling at night. So short sleeves during the day will
likely be replaced by a sweat shirt at night. But the dry air will
also mean a quick warm up for the afternoon hours. ty
SUNDAY NIGHT THROUGH WEDNESDAY: A ridge of high pressure will
dominate the region leading to dry conditions and near to above
normal temperatures. The main challenge during the period will be
potential for breezy winds as a pair of weather disturbances slide
around the northern and eastern periphery of the ridge. The first
potential for winds will come on Sunday night and early Monday as
a Polar surface high drops south along and east of the Continental
Divide....through the Canadian and US Northern Plains. This will
lead to a light push of northerly winds down the Okanogan Valley
Sunday evening transitioning to stronger east to northeasterly
winds through the Purcell Trench Sunday night and Monday. It does
not appear any wind highlights will be necessary but gusts to 30
mph will be possible given the current suite of model guidance.
The next bout of winds will be possible Tuesday night into
Wednesday as the ridge flattens and a trof swings through central
BC. This is a more classical breezy to windy pattern for the
Inland NW as a surface low deepens over southern Alberta leading
to breezy west to southwesterly winds for much of the Basin and
ridgetops. High temperatures during the period are expected to
warm near to above normal...generally in the 60`s with overnight
lows continuing to flirt with freezing in the northern valleys and
mid to upper 30`s to low 40`s elsewhere. /sb
&&
.AVIATION...
00Z TAFs: A weakening mid-level upper low and influx of moisture
(largely in the mid-levels too) will bring a threat of widely sct
to isolated showers around TAF sites this evening, with chances
waning into the overnight as instability dissipates. Isolated
embedded thunderstorms are possible toward the Blue Mountains
through central Panhandle. A few may slip by KLWS/KPUW but the
threat is minimal. Storms may contain locally gusty winds, heavy
downpours of rain and/or small hail/graupel, which may briefly
reduce visibilities to under 3 miles at times. Otherwise expect
VFR conditions. Another wave approaches the region later Thursday,
renewing the threat of showers and isolated thunderstorms to most
locations. However overall forcing remains weak to the highest
chances will be tied to the higher terrain. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 38 56 40 59 39 60 / 30 40 20 20 10 0
Coeur d`Alene 36 55 37 58 39 59 / 30 50 20 30 10 0
Pullman 39 59 40 57 40 61 / 20 40 20 30 10 0
Lewiston 43 63 45 63 43 66 / 20 30 20 30 10 0
Colville 34 60 35 63 36 64 / 30 50 20 20 10 0
Sandpoint 34 51 34 54 35 58 / 30 50 20 30 10 0
Kellogg 37 55 37 55 36 58 / 40 50 30 40 20 0
Moses Lake 39 62 41 65 39 66 / 30 20 10 10 0 0
Wenatchee 41 62 42 65 43 66 / 20 20 10 10 0 0
Omak 37 60 38 63 36 66 / 30 30 20 10 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1037 PM CDT WED MAR 27 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 229 PM CDT WED MAR 27 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
STRETCHING FROM THE GULF COAST UP THE MISSISSIPPI RIVER TO CENTRAL
CANADA EARLY THIS AFTERNOON. LINGERING CLOUD COVER AT THE BASE OF
THE INVERSION REMAINS ARCED FROM NORTHERN INDIANA TO WESTERN
ONTARIO...BUT HAS BEEN SLOWLY BREAKING UP. SKIES BECOME CLEAR ON
EITHER SIDE OF THIS ARCING CLOUD BAND WITH TEMPS MAINLY IN THE 30S
TO LOWER 40S. CLOUDS AND TEMPS REMAIN THE MAIN FORECAST CONCERNS.
TONIGHT...HIGH PRESSURE RIDGE AXIS WILL GRADUALLY MOVE EAST FROM THE
NORTHERN MISSISSIPPI VALLEY INTO WESTERN WISCONSIN. OVERCAST 5-6KFT
CLOUD DECK HAS BECOME THINNER BASED OFF OF 12Z SOUNDINGS...AND
STARTED TO BREAK UP BY LATE IN THE MORNING. BUT STILL NOT AN EASY
CLOUD FORECAST TONIGHT. BASED ON THE RATE OF CLEARING SO FAR
TODAY...WENT MORE OPTIMISTIC WITH SKY COVER THIS EVENING...AND SHOW
MOSTLY CLEAR SKIES ARRIVING BY MIDNIGHT EXCEPT FOR WESTERN SECTIONS
OF THE CWA. FORECASTED LOWS ARE DEPENDENT UPON CLEARING AGAIN SO
CONFIDENCE IS LOW ONCE AGAIN. WILL GO WITH LOWS MAINLY IN THE 20S
EXCEPT A FEW COLD SPOTS MAY DROP A COUPLE DEGREES COLDER.
THURSDAY...HIGH PRESSURE WILL BE OVER THE REGION...LEADING TO
ANOTHER QUIET DAY. A MOSTLY CLEAR TO PARTLY CLOUDY START TO THE
DAY...WILL SEE DIURNAL CU BUILD BY EARLY IN THE AFTERNOON. HIGHS A
COUPLE DEGREES WARMER INTO THE LOW TO MID 40S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 229 PM CDT WED MAR 27 2013
SPLIT FLOW OVER THE ERN PACIFIC CONTS TO GIVE THE MDLS FITS AS TO
WHAT THE FLOW WL DO DOWNSTREAM OVER THE CONUS. LATEST TREND IS TO
BRING A NRN BRANCH SYSTEM THRU THE GREAT LAKES THIS WEEKEND...THEN
SWING A POLAR VORTEX SOUTH/THEN EAST ACROS SRN ONTARIO/SRN QUEBEC
EARLY NEXT WEEK. THIS TREND WOULD BRING UNSETTLED WEATHER TO NE WI
DURING THE WEEKEND/MON...TO BE FOLLOWED BY A DRYING TREND THEREAFTER.
TEMPS SHOULD BE AT OR EVEN SLIGHTLY ABOVE NORMAL INTO THE WEEKEND
AND THEN COOL TO BELOW NORMAL LEVELS FOR THE FIRST HALF OF NEXT WEEK.
RDG OF HI PRES TO EXTEND FROM THE UPR MS VALLEY SEWD THRU WI TO
THE TN VALLEY REGION THU NGT. ANY DAYTIME CU FIELD WL DISSIPATE UPON
SUNSET LEAVING GENERALLY MOSTLY CLEAR SKIES AND LIGHT WINDS OVER NE
WI. THIS SYNOPTIC SET-UP COULD BRING SOME LATE NIGHT FOG INTO THE
AREA AS MELTING SNOW ADDS MOISTURE TO THE ATMOSPHERE. MIN TEMPS ARE
EXPECTED TO DIP INTO THE UPR TEENS NORTH...MID 20S E-CNTRL WI.
THIS SFC RDG AXIS SLIDES ACROSS WI FRI MORNING AND BE TO OUR EAST
BY THE AFTERNOON HOURS. LIGHT W-NW WINDS WL BACK W-SW WITH WEAK WAA
BEGINNING IN THE AFTERNOON. UNDER MOSTLY SUNNY SKIES...MAX TEMPS
SHOULD BE ABLE TO RANGE FROM THE LWR TO MID 40S NORTH...MID TO UPR
40S CNTRL/E-CNTRL WI. ONLY EXCEPTION MIGHT BE ALONG LAKE MI WHERE
AN ONSHORE WIND MAY KEEP READINGS IN THE LWR 40S.
AS THE NEXT WEATHER SYSTEM (IN THE FORM OF A CDFNT AND SHORTWAVE
TROF) DROPS SE THRU THE NRN PLAINS AND REACHES THE UPR MIDWEST BY
DAYBREAK...SW WINDS WL BEGIN TO DRAW MOISTURE TOWARD WI WHICH WL
GRADUALLY INCREASE CLOUDS ACROSS WI. MAY NEED TO RAISE TEMPS OVER
CNTRL WI WHERE THE CLOUDS TO REACH FIRST BY A FEW DEGS (UPR 20S TO
AROUND 30) WHILE KEEPING ERN WI SIMILAR TO THE PREVIOUS FCST (UPR
20S).
MDLS CONT TO SHOW THE APPROACH OF A SFC CDFNT/MID-LEVEL SHORWAVE
TROF TOWARD THE WRN GREAT LAKES ON SAT. SOUTH WINDS IN PLACE AHEAD
OF THIS SYSTEM WL BRING AN INCREASE IN BOTH MOISTURE AND ISEN LIFT
TO WI AND EXPECT TO SEE PCPN CHCS INCREASE FROM WEST TO EAST...
ESPECIALLY AS BETTER MOISTURE CONVERGENCE/FORCING ARRIVE. THERE
COULD BE A LINGERING PCPN TYPE ISSUE OVER CNTRL WI EARLY SAT
MORNING WITH SFC TEMPS BELOW 32 DEGS AND A SMALL LAYER OF ABOVE
FREEZING TEMPS JUST ABOVE THE SFC. MAY NEED TO MENTION A LITTLE
SLEET INITIALLY BEFORE THE PCPN TRANSITIONS TO EITHER ALL RAIN OR
A RAIN/SNOW MIX BY MID-MORNING. BY SAT AFTERNOON...TEMPS TO HAVE
WARMED ENUF TO CARRY HI CHC POPS OF RAIN FOR THE ENTIRE FCST AREA.
CDFNT/SHORTWAVE TROF PUSH THRU WI MAINLY SAT EVENING (PERHAPS
AROUND MIDNGT OVER THE EAST)...THUS WL CONT THE NEED FOR POPS IN
THE FCST. PCPN TYPE TIMING REMAINS AN ISSUE DEPENDING ON HOW FAST
COOLER AIR SPREADS INTO THE REGION BEHIND THE CDFNT. HAVE ATTEMPTED
TO SHOW THIS GRADUAL TRANSITION IN THE GRIDS WITH N-CNTRL WI ALL
SNOW BY MIDNGT AND RAIN BECOMING MIXED WITH SNOW AFTER MIDNGT
E-CNTRL WI. DO NOT EXPECT MUCH IN THE WAY OF ACCUMULATION SAT NGT
AS BETTER MOISTURE TO ALREADY HAVE BEEN SHUNTED EAST BY THE TIME
THE COOLER AIR ARRIVES. MDL DIFFERENCES REMAIN ON SUNDAY AS THE
GFS DRIVES A SECONDARY CDFNT THRU WI...WHILE THE REST OF THE MDLS
HOLD THIS SECOND FNT BACK OVER NRN SECTIONS OF THE GREAT LAKES. IF
THE LATTER SOLUTION IS CORRECT...PCPN CHCS MAY BE LIMITED TO NRN
WI CLOSER TO THE FNT AND A SHORTWAVE ROTATING SEWD TOWARD THE WRN
GREAT LAKES. WOULD STILL EXPECT A DECENT AMOUNT OF CLOUDS IN THIS
COLD...CYCLONIC PATTERN LEFT OVER THE STATE ON SUNDAY WITH MAX
TEMPS DIPPING INTO THE UPR 30S TO MID 40S.
THIS SECOND CDFNT TO DROP SOUTH INTO CNTRL SECTIONS OF WI SUNDAY
NGT AND SHOVE OUT OF WI ALTOGETHER ON MON. SOME SNOW SHWRS MAY
ACCOMPANY THIS FROPA...BUT THE MAIN FOCUS FOR SNOW SHWR ACTIVITY
WOULD BE LAKE EFFECT OVER N-CNTRL WI AS 8H TEMPS OVER LAKE SUPERIOR
DROP TO AROUND -17C BY 12Z MON...DELTA-T`S CLIMB INTO THE UPR TEENS
AND THERE IS LITTLE IN THE WAY OF ANY LOW-LEVEL INVERSIONS. THE
ONLY THING LACKING IS FAVORABLE TRAJS AS WINDS TO BE FROM THE W-NW.
NEVERTHELESS...WL CARRY A MEDIUM CHC POP FOR VILAS CNTY SUNDAY NGT
INTO MON WITH LESSER POPS FARTHER SOUTH AS THE CYCLONIC FLOW
PERSISTS THRU MON.
THE LAKE EFFECT FOR N-CNTRL WI COULD LINGER INTO TUE MORNING BEFORE
A LARGE AREA OF HI PRES OVER THE NRN PLAINS BEGINS TO BUILD EWD AND
SENDS ENUF DRY AIR TOWARD WI TO END THE LAKE EFFECT. THE REST OF NE
WI WL SEE A DECENT AMOUNT OF SUNSHINE...ALBEIT WITH BELOW NORMAL
TEMPS. THIS HI PRES THEN OVERSPREADS THE WRN GREAT LAKES BY NEXT
WED WHICH WL BRING A MIX OF SUN AND CLOUDS ALONG WITH LIGHT WINDS.
TEMPS SHOULD BEGIN A SLOW MODERATION WITH MAX TEMPS REACHING THE
UPR 30S TO LWR 40S.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1035 PM CDT WED MAR 27 2013
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD.
SOME DIURNAL CU EXPECTED AGAIN ON THU AFTN. VFR CONDITIONS
EXPECTED THROUGH THE TAF PERIOD.
&&
.HYDROLOGY...
ISSUED AT 229 PM CDT WED MAR 27 2013
EXPECT A GRADUAL MODERATION IN TEMPERATURES FOR THE
REST OF THE WEEK...WITH HIGHS REACHING INTO MID TO UPPER 40S OVER
THE FORECAST AREA THIS WEEKEND. THIS WILL RESULT IN A GRADUAL MELTING
OF THE SNOWPACK. RAIN OR MIXED PCPN IS EXPECTED THIS WEEKEND...BUT
PCPN AMOUNTS SHOULD BE FAIRLY LIGHT. GIVEN THIS SCENARIO...THE
EXPECTED RUNOFF SHOULD ONLY CAUSE A GRADUAL RISE IN THE RIVERS
OVER CENTRAL AND EAST CENTRAL WISCONSIN BY THE WEEKEND.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......TE
HYDROLOGY......MPC
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SYNOPSIS...
ISSUED AT 229 PM CDT TUE MAR 26 2013
QUIET WEATHER WITH MODERATING TEMPERATURES THE REST OF THE WORK
WEEK...SOME LIGHT PRECIPTIATION THIS WEEKEND...THEN PROBABLY
COLDER AGAIN NEXT WEEK.
THE BLOCKING ACRS THE CONUS WL EASE DURING THE PERIOD...WITH LOW
AMPLITUDE WNWLY UPR FLOW BECOMING RE-ESTABLISHED. BUT THE FLOW AT
HIGHER LATITUDES WL REMAIN BLOCKY. THE BREAK DOWN OF THE MIDDLE
LATITUDE BLOCKING WL ALLOW W TO E PROGRESSION OF WX SYSTEMS TO
RESUME...AND TEMPERATURES TO MODERATE BACK TO NEAR OR EVEN A
LITTLE ABOVE SEASONAL NORMALS. BUT IT WL BE TOUGH TO GET ANY
PROLONGED SIGNIFICANT WARMING AS LONG AS HIGH LATITUDES ARE
BLOCKED...AND ANOTHER SHOT OF CHILLY CANADIAN AIR IS LIKELY TO
OVERSPREAD THE AREA EARLY NEXT WK. THE PATTERN LOOKS UNFAVORABLE
FOR SIG PCPN.
&&
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 229 PM CDT TUE MAR 26 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SHORTWAVE
ACTIVITY PROGRESSING SOUTH ACROSS MUCH OF CENTRAL AND SOUTHERN
WISCONSIN. DEEP CYCLONIC FLOW AND COLD TEMPS ALOFT HAVE MAINTAINED
A WIDESPREAD VFR CLOUD DECK FROM NORTHERN ILLINOIS/INDIANA TO
WESTERN ONTARIO. FLURRY ACTIVITY MOVED OUT OF THE AREA FOR THE MOST
PART BY LATE IN THE MORNING...BUT DIURNAL INSTABILITY GENERATED SCT
SNOW SHOWERS EARLY THIS AFTERNOON ACROSS MUCH OF THE AREA. THINK
MUCH OF THE SNOW SHOWERS WILL DISSIPATE WITH LOSS OF HEATING LATE
THIS AFTERNOON OR EARLY THIS EVENING...BUT WILL KEEP A MENTION OF FLURRIES
GOING THROUGH 01Z. DRIER AIR IS MOVING SE OVER EASTERN UPPER
MICHIGAN AND LAKE SUPERIOR...AND IS APPROACHING NORTHERN LAKE
MICHIGAN EARLY THIS AFTERNOON. BESIDES THE SNOW SHOWERS...CLOUD
TRENDS ARE THE MAIN FORECAST CONCERN.
TONIGHT...THE SHORTWAVE TROUGH WILL MOVE SOUTHEAST OVER THE
SOUTH-CENTRAL GREAT LAKES TOWARDS THE OHIO VALLEY. CHALLENGING
CLOUD FORECAST TONIGHT...WHICH WILL IMPACT TEMPS. MID-LEVEL HEIGHT
RISES WILL ONLY BE MODEST THIS EVENING...SO NOT ANTICIPATING A FAST
CLEARING TREND. ADVECTION OF DRIER AIR FROM THE NORTHEAST AND ALSO
FROM HIGH PRESSURE OVER THE NORTHERN PLAINS WILL CAUSE THE MID-LEVEL
MOISTURE RIBBON TO BECOME STRETCHED ACROSS NORTHEAST WISCONSIN
TONIGHT. AS A RESULT...THINK CLOUDS SHOULD THIN AS HOLES DEVELOP
THROUGH THE NIGHT. CLOUDS TO HANG A BIT LONGER OVER N-C WISCONSIN
WHERE FLOW REMAINS OFF LAKE SUPERIOR. IN THE END...MOSTLY CLOUDY
THIS EVENING TO BECOME PARTLY CLOUDY OVERNIGHT. IF SKY CLEARS OUT
QUICKER...TEMPS WILL FALL LOWER THAN CURRENTLY PLANNED. WILL GO
WITH LOWS IN THE MID TEENS OVER THE COLD SPOT OF CENTRAL
WISCONSIN...TO THE MID 20S NEAR LAKE MICHIGAN.
WEDNESDAY...WILL STILL HAVE CYCLONIC FLOW THROUGH THE COLUMN
TOMORROW...ALONG WITH AMPLE LOW LEVEL MOISTURE. AS LOW LEVEL LAPSE
RATES STEEPEN WITH MORE IN THE WAY OF SUNSHINE...SHOULD SEE
LINGERING CLOUD COVER BECOME ENHANCED THROUGH DIURNAL TEMPS RISES BY LATE
MORNING TO EARLY AFTERNOON. TEMPS ALOFT WILL BE SIMILAR TO
TODAY...BUT SHOULD SEE MORE SUNSHINE...SO WILL GO WITH TEMPS MAYBE A
DEGREE WARMER THAN TODAY.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 229 PM CDT TUE MAR 26 2013
QUIET FOR THE REST OF THE WORK WEEK AS HIGH PRESSURE RIDGING SWD
FM CANADA CONTROLS THE WX ACRS THE AREA. MODERATION OF THE AIR
MASS SHOULD YIELD A LITTLE WARMING EACH DAY...ESP ONCE LOW-LEVELS
DRY OUT A BIT MORE AND THERE ARE FEWER CLDS.
STILL LOOKS LIKE THERE IS A CHC FOR PCPN WITH SHRTWV CROSSING THE
AREA THIS WEEKEND. LATER SAT AND SAT NGT SEEM TO BE MOST FAVORED
TIME PERIOD. BUT WITH LIMITED MOISTURE AND MODEST FORCING AT
BEST...PCPN AMNTS WL BE LIGHT AND SOME AREAS MAY MISS OUT ON THE
PCPN COMPLETELY.
UPR VORTEX DIGGING ESE THROUGH THE LAKE SUPERIOR RGN COULD BRING
ANOTHER BATCH OF LGT PCPN LATE IN THE WEEKEND OR EARLY NEXT WK.
BUT IT/S MAIN INFLUENCE WL BE TO USHER ANOTHER COLD AIR MASS INTO
THE AREA.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1231 PM CDT TUE MAR 26 2013
SCT FLURRY ACTIVITY WILL DIMINISH THIS AFTERNOON WHEN AN
UPPER LEVEL DISTURBANCE DEPARTS TO THE SOUTHEAST. MID-LEVEL CLOUD
DECK WILL HANG AROUND LONGER...AND TIMING OF THE ARRIVAL OF CLEARING
IS NOT CLEAR-CUT. DRIER AIR IS WORKING INTO THE REGION FROM THE
NORTHEAST...AND INCREASING SUBSIDENCE BEHIND THE UPPER LEVEL
DISTURBANCE POINTS TOWARDS A SLOW CLEARING TAKING PLACE THIS EVENING
INTO THE OVERNIGHT HOURS. LOW LEVEL FLOW WILL REMAIN OFF LAKE
SUPERIOR...SO ANTICIPATE CLOUDS HANGING AROUND THROUGH THE REST OF
THE TAF PERIOD OVER FAR N-C WISCONSIN. DESPITE THE CLOUD
COVER...MAINLY VFR CONDITIONS THROUGH LATE MORNING TOMORROW.
DIURNAL CU TO BUILD MIDDAY TOMORROW DUE TO STEEP LOW LEVEL LAPSE
RATES.
&&
.HYDROLOGY...
ISSUED AT 229 PM CDT TUE MAR 26 2013
CONDITIONS FOR A FAST SNOWMELT NOT ON THE RADAR FOR
MOST OF THE WORK WEEK...WITH CONTINUED DRY WEATHER AND COOL
TEMPERATURES PERSISTING. HOWEVER...THERE STILL WILL BE A GRADUAL
EROSION OF THE SNOWPACK WITH TEMPERATURES CLIMBING ABOVE THE
FREEZING MARK EACH DAY. RUNOFF POTENTIAL FROM SNOW MELT INCREASES
FOR NEXT WEEKEND WITH FORECAST TEMPERATURES CLIMBING TO THE LOWER
TO MIDDLE 40S ON FRIDAY/SATURDAY/SUNDAY. OVERNIGHT LOW TEMPERATURES
SATURDAY NIGHT ONLY FALL TO THE FREEZING MARK OVER EAST CENTRAL
WISCONSIN AHEAD OF A WEAK COOL FRONT TO KEEP THE SNOWMELT
PARTIALLY GOING. WITH THIS SCENARIO...THE MAIN AFFECTS OF RUNOFF
COULD PRODUCE SOME PONDING OF WATER...AND A RISE IN THE RIVERS
OVER CENTRAL AND EAST CENTRAL WISCONSIN LATE NEXT WEEKEND. RAIN
OR MIXED PCPN MAY ALSO OCCUR THIS WEEKEND WITH THE FRONT...BUT
PCPN AMOUNTS LOOK LIKE THEY WILL BE FAIRLY LIGHT AT THIS TIME.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......MPC
HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
606 AM CDT TUE MAR 26 2013
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
323 AM CDT TUE MAR 26 2013
MAIN FORECAST CONCERNS THIS PACKAGE...CLOUD AND TEMPERATURE TRENDS
THROUGH THE PERIOD.
06Z DATA ANALYSIS HAD AN AREA OF LOW PRESSURE CENTERED OFF THE MID
ATLANTIC COAST WITH ITS BROAD CIRCULATION AS FAR NORTHWEST AS ONT/
MN/IA/WI. A RIDGE OF HIGH PRESSURE EXTENDED FROM MAN TO TX. LOWER
LEVEL MOISTURE WRAPPING AROUND THE BROAD LOW CIRCULATION REMAINED
OVER WI AND EASTERN MN/IA. TEMPERATURES UNDER THE CLOUDS WERE MOSTLY
IN THE MID 20S-LOW 30S WHILE FURTHER WEST CLOSER TO THE SFC RIDGE
AXIS MOST TEMPERATURES WERE IN THE SINGLE DIGITS AND TEENS.
26.00Z MODELS INITIALIZED WELL AND OFFER SIMILAR SOLUTIONS FOR TODAY
THRU THU NIGHT AS HGTS SLOWLY RISE AND THE LOW/MID LEVELS GRADUALLY
WARM. DPROG/DT OF 500MB HGTS AT 26.00Z SHOWED THE MODEL RUNS OF
24.00Z AND 25.00Z VERIFIED QUITE WELL ACROSS NOAM/EASTERN PAC
CONSIDERING ALL THE SMALLER WAVES/RIPPLES IN THE RATHER ACTIVE FLOW
PATTERN. TREND FAVORS A CONSENSUS OF THE EARLIER RUNS WITH MOST OF
THE FEATURES. TIGHTER CONSENSUS FOR TODAY THRU WED NIGHT FOR
LONGWAVE TROUGHING TO REMAIN OVER THE EASTERN CONUS...CONFLUENT
NORTHWEST FLOW TO REMAIN OVER THE UPPER MIDWEST AND WEAK RIDGING TO
BUILD INTO SOUTH-CENTRAL CAN. CONSISTENCY REMAINS AS GOOD AS CAN BE
EXPECTED BY THU/THU NIGHT...ESPECIALLY WITH THE SHORTWAVE DETAILS
IN RATHER BROAD NORTHWEST FLOW FROM SOUTHWEST CAN TO THE SOUTHEAST
U.S. COAST AS THE EASTERN CONUS TROUGH BEGINS TO EXIT OFF THE COAST.
CHECK OF OBS VS. MODEL DATA AT 06Z SHOW ALL TO BE GOOD WITH THE SFC
MASS FIELDS OVER CENTRAL NOAM. DETERMINISTIC MODELS GENERALLY
STRUGGLING WITH THE CLOUDS/MOISTURE NEAR 850MB ACROSS MN/IA/WI...
MOST TEND TO BE TOO FAR WEST WITH THE MOISTURE/CLOUDS OVER MN/IA.
HOWEVER ALL DO GIVE INDICATIONS OF THE HOLES SEEN IN THE CLOUD DECKS
EARLY THIS MORNING. SREF MEAN ACTUALLY LOOKS TO HAVE A DECENT HANDLE
ON THE 850MB MOISTURE/CLOUDS AT 06Z. PER WV IMAGERY...MODELS ALL
APPEAR RESPECTABLE WITH THE SHORTWAVE DETAILS OVER NOAM/EASTERN
PAC. NO ONE MODEL FAVORITE AND WITH A TREND TOWARD A TIGHTER...
COMPROMISE CONSENSUS THRU WED NIGHT...FAVORED A MODEL/ENSEMBLE
BLEND. SHORT TERM FCST CONFIDENCE AVERAGE TO GOOD THIS CYCLE.
IN THE SHORT TERM...MOISTURE AND CLOUDS NEAR 850MB WILL BE
PROBLEMATIC TODAY INTO WED. AXIS OF MOISTURE/CLOUDS FROM NORTH OF
LK SUPERIOR SOUTHWARD ACROSS WI/MI ROTATES SLOWLY SOUTH-SOUTHWEST
ON THE WESTERN EDGE OF THE BROAD EASTERN CONUS CIRCULATION. 850MB
GRADIENT WEAKENS OVER THE AREA TODAY...SO THIS MOISTURE/CLOUDS LOOK
STUCK OVER THE AREA AT LEAST TODAY. INCREASED/HELD MORE CLOUD COVER
OVER THE AREA TODAY...ESPECIALLY ALONG/EAST OF THE MS RIVER. THIS
MOISTURE REMAINS OVER THE AREA TONIGHT...BUT BECOMES SHALLOWER
UNDER A SUBSIDENCE INVERSION AS THE SFC-850MB AXIS IN THE PLAINS
MOVES EAST INTO MN/IA. BY TONIGHT/WED 850MB TEMPS START TO WARM AS
WELL. WITH NO INFLUX OF NEW MOISTURE...WILL REMAIN OPTIMISTIC FOR
CLOUDS TO DECREASE TONIGHT. WINDS LIGHTER TONIGHT AS THE SFC RIDGE
AXIS MOVES INTO MN/IA...FOR A COLDER NIGHT MOST AREAS WITHOUT THE
CLOUD BLANKET.
925-850MB TEMPS SLOWLY WARM WED/THU WITH MORE SUNSHINE/MIXING AS
THE SFC RIDGE AXIS DRIFTS OVER THE AREA AND THE PATTERN SLOWLY
PROGRESSES. MORE SUNSHINE AND GRADUAL AIRMASS MODIFICATION LOOK TO
ADD ABOUT A CATEGORY TO THE HIGHS BOTH WED AND THU.
PRECIP CHANCE REMAIN ABOUT NIL TODAY THRU THU NIGHT WITH A STRONG
CONSENSUS FOR A DRY 825-500MB AIRMASS OVER THE REGION AND THE
SHORTWAVES IN THE NORTHWEST FLOW WEAKENING AS THE DROP INTO THE
CONFLUENT MID LEVEL FLOW OVER THE UPPER MIDWEST.
FAVORING THE MODEL/ENSEMBLE CONSENSUS...USED A BLEND OF THE
NUMERICAL GUIDANCE HIGHS/LOWS FOR TODAY THRU THU NIGHT. WILL HAVE TO
WATCH LOWS TONIGHT IF SKIES CLEAR QUICKLY THIS EVENING AND WINDS
BECOME LIGHT/VARIABLE. LOWS IN SOME OF THE SHELTERED/NORMALLY
COLDER VALLEYS COULD DROP INTO THE SINGLE DIGITS OVER THE
PERSISTENT SNOW COVER.
.LONG TERM...FRIDAY THROUGH MONDAY
323 AM CDT TUE MAR 26 2013
26.00Z MEDIUM RANGE MODELS IN GOOD AGREEMENT FOR DRY/QUIET/WARMING
WEATHER TO CONTINUE FRI. THIS AS HGTS SLOWLY RISE...THE SFC RIDGE
AXIS DRIFTING EAST OF THE AREA AND LOW LEVEL WARM ADVECTION
INCREASING OVER MN/IA/WI. HIGHS FRI LOOKING TO TACK ON ANOTHER
CATEGORY OR TWO OVER THOSE OF THU AS 925MB TEMPS CLIMB ABOVE 0C
ACROSS THE AREA.
CONSISTENCY REMAINS GOOD FOR A STRONGER NORTHWEST FLOW SHORTWAVE
AND TROUGH TO APPROACH SAT...PUSHING A MDT COLD FRONT SOUTHEAST
ACROSS THE UPPER MIDWEST. MOISTURE/LIFT INCREASE AHEAD OF/WITH THIS
FRONT/TROUGH...WITH PW VALUES IN THE 0.5 TO 0.75 INCH RANGE BY SAT
AFTERNOON. MODEST/MOIST ADIABATIC LAPSE RATES INDICATED ABOVE 800MB
AS WELL...FOR MORE EASILY VERTICALLY MOVED PARCELS. COLUMN WARM
ENOUGH FOR ANY PRECIP AS RAIN SAT/SAT EVENING. WITH AREA AHEAD OF
THE FRONT ON SAT AND CONTINUED LOW LEVEL WARM ADVECTION...HIGHS IN
THE UPPER 40S-LOW 50S APPEAR REASONABLE.
CONFIDENCE DROPS FOR SAT NIGHT THRU MON AS MODELS DIFFER ON THE
DETAILS WITH THE CANADIAN AIRMASS INTRUSION BEHIND THE COLD FRONT
STARTING SAT NIGHT. GFS WITH A RAPID INFLUX OF COLDER AIR ALREADY BY
SUN MORNING...ECMWF/UKMET WOULD BRING THE COLDER AIR IN BEHIND A
SECONDARY COLD FRONT SUN NIGHT WHILE GEM A GLANCING BLOW AT BEST.
ECMWF OFFERS THE BETTER RUN-TO-RUN CONSISTENCY WITH ITS 25.00Z AND
25.12Z RUNS FOR THIS TIME PERIOD...WHICH GIVES THE AREA A COOLER DAY
SUNDAY...BUT STILL NEAR NORMAL. WITH THE MIXED TEMP/COLD AIR SIGNALS
BEHIND THE FIRST FRONT...WILL LEAVE PRECIP CHANCES FOR LATE SAT
NIGHT/SUN MORNING AS -RA OR -SN FOR MUCH OF THE AREA. FAVORING
THE MODEL/ENSEMBLE CONSENSUS IN THE DAY 6/7 TIME-FRAME...SMALL -RA
AND/ OR -SN CHANCES SUN-MON IN COLDER CYCLONIC FLOW LOOK REASONABLE
FOR NOW. MODEL/ENSEMBLE CONSENSUS OF THE HIGHS/LOWS FOR FRI-MON LOOK
GOOD AS WELL UNTIL A CLEARER/PREFERRED MODEL SIGNAL IS SEEN.
&&
.AVIATION...TODAY AND TONIGHT
606 AM CDT TUE MAR 26 2013
LARGE AREA OF VFR CLOUDS COVERS MUCH OF WISCONSIN AND THE EASTERN
SECTIONS OF MINNESOTA EARLY THIS MORNING. ONE OF THE LAST PATCHES
OF CLEARING IS OVER KLSE BUT SATELLITE IMAGES SHOW THE CLOUDS
WILL BE PUSHING BACK OVER KLSE AROUND 12Z AND PLAN TO START THEM
WITH A BROKEN VFR CEILING. WITH ALL THE CLOUDS UPSTREAM...EXPECT
THE VFR CEILINGS TO REMAIN IN PLACE UNTIL THE HIGH PRESSURE RIDGE
FROM THE WEST CAN BUILD OVER THE AREA. THE 26.06Z NAM AND 26.09Z
RAP INDICATE THE RIDGE COMING IN LATE THIS AFTERNOON INTO THE
EVENING. THE RAP BUFKIT SOUNDINGS SEEM TO HAVE A BETTER HANDLE ON
THE MOISTURE WITH THE CLOUDS AND SUGGESTS KRST SHOULD SCATTER OUT
LATE THIS AFTERNOON WITH THE CLOUDS BREAKING UP AT KLSE THIS
EVENING. ONCE THE CLOUDS BREAK UP...EXPECTING CLEAR SKIES TO
PREVAIL THROUGH THE OVERNIGHT HOURS WITH THE HIGH CONTINUING TO
BUILD INTO THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
323 AM CDT TUE MAR 26 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
345 AM CDT THU MAR 28 2013
.DISCUSSION...
332 AM CDT
WHILE THE FORECAST IS GENERALLY QUIET...THERE ARE SOME CHALLENGES.
THESE CONTINUE TO BE TEMPERATURES AND WEIGHING THE EFFECTS OF THE
LAKE BREEZE FOR DOWNTOWN CHICAGO AND OTHER NEARBY
LOCATIONS...FOLLOWED BY RAIN LIKELIHOOD SATURDAY NIGHT AND THE
PATTERN BEHIND THE COLD FRONT.
WHILE THE UPPER AND MID-LEVEL WIND FLOW REMAINS NORTHWESTERLY...THE
AIR MASS IS BECOMING MORE PACIFIC ORIGIN THAN MODIFIED ARCTIC PER
UPPER AIR ANALYSES. THE HIGH PRESSURE RIDGE IS CENTERED NEAR THE
MISSISSIPPI RIVER EARLY THIS MORNING AND WILL MOVE OVER THE AREA
BY AFTERNOON AND PERSIST THROUGH LATE IN THE DAY FRIDAY. THIS
LIGHT PRESSURE GRADIENT FORCE ALONG WITH MORE SUNSHINE TOWARD
WARMING TEMPERATURES OVER LAND WILL CERTAINLY FOSTER LAKE BREEZE
DEVELOPMENT. IT IS LIKELY THIS WILL BE EARLIER THAN THE PAST TWO
DAYS GIVEN THE SETUP. THIS IS SUPPORTED BY THE HRRR WHICH STARTS
THE LAKE BREEZE NEAR 11 AM. HAVE CONTINUED TO REFLECT A DROPPING
AND THEN STABILIZING TEMPERATURE TREND NEAR THE LAKE SHORE...WITH
AFTERNOON READINGS LIKELY IN THE UPPER AND MAYBE EVEN MID 30S. AS
FOR THE REMAINDER OF THE FORECAST AREA...SOME CU IS POSSIBLE
NAMELY OVER NE IL AND NW IN AS THE LAST OF THE COLD AIR ALOFT
SCOOTS OUT. THE WARM AIR ADVECTION IN ITS PLACE AND FURTHER MIXING
SHOULD ALLOW FOR WIDESPREAD HIGHS IN THE MID 40S...BASICALLY THE
HIGHS OF YESTERDAY PLUS THREE TO FOUR DEGREES.
ANOTHER SHARP UPPER TROUGH WILL DIG INTO THE GREAT LAKES REGION BY
EARLY NEXT WEEK...WITH A FIRST SEEMINGLY WELL-DEFINED SHORT WAVE
AND SURFACE TROUGH ADVANCING THROUGH THE AREA SATURDAY NIGHT. THE
NAM...GFS...AND EC ALL AGREE ON A SURFACE LOW RESPONSE FROM
NORTHERN MO THROUGH OUR AREA DURING SATURDAY NIGHT...WITH A
FOCUSED MOIST ADVECTION AND CONVERGENCE AREA MOVING ACROSS WITHIN
FAIRLY GOOD UPPER FORCING. HAVE CONTINUED TO INCH UP POPS FOR
SATURDAY EVENING. SOME GUIDANCE INCLUDING THE EC AND NAM ALREADY
SPREAD RAIN INTO THE WESTERN AND SOUTHWESTERN FORECAST AREA AS
EARLY AS MID TO LATE AFTERNOON AND HAVE CONTINUED TO ACCOUNT FOR
THAT. MORE MEMBERS OF THE GEFS SHOW POTENTIAL FOR OVER A QUARTER
OF AN INCH BUT VERY FEW INCLUDING IN THE SREF GIVE OVER ONE HALF
AN INCH.
TEMPERATURES IN ADVANCE OF THE FRONT LOOK TO EXCEED 50 AREA-WIDE
ON SATURDAY WITH A MILD NIGHT AS THE CLOUDS AND THE BOUNDARY PASS.
SUNDAY TEMPERATURES IN THE UPPER 40S TO MID 50S ARE LOOKING MORE
CONFIDENT THANKS TO A HIGH STARTING POINT AND THE FIRST COLD FRONT
NOT BRINGING MUCH OF A COLD AIR DUMP. THAT WILL COME SUNDAY NIGHT
WITH A COOL PATTERN TO START NEXT WEEK AS 850 MB TEMPERATURES DROP
ONCE AGAIN TO ONE AND A HALF STANDARD DEVIATIONS BELOW NORMAL /PER
GEFS AND EC FORECASTS/. HAVE ADAPTED LOCAL CLIMATOLOGICAL RESEARCH
FOR THESE 850MB TEMPERATURES OF -10C INTO THE FORECAST...WHICH
INDICATE GOOD POTENTIAL FOR HIGHS TO REMAIN AT OR BELOW 40 IN
CHICAGO...WHICH ALREADY LOOKED PRETTY GOOD IN THE FORECAST. ONE
THING ABOUT NEXT WEEK COMPARED TO THE COOL TEMPERATURES OF EARLIER
THIS WEEK IS THAT WHILE UNDER CYCLONIC FLOW AGAIN WE WILL BE LESS
ENTRENCHED AND THUS LESS FAVORED FOR CONTINUOUS STARTOCU. WE
SHOULD HAVE SOME DURING THE DAYS BUT WE ARE FURTHER FROM THE
CYCLONIC CENTER WHICH WILL BE UP IN QUEBEC ALREADY BY MONDAY
AFTERNOON. NO SIGN OF A MAJOR WARM-UP BUT A GRADUAL ONE LATE NEXT
WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LAKE BREEZE DEVELOPMENT DURING THU AND HOW FAR INLAND IT
REACHES DURING BY EVENING.
TRS
//DISCUSSION...UPDATED 06Z...
A RIDGE OF HIGH PRESSURE CURRENTLY EXTENDS FROM WESTERN HUDSON
BAY SOUTH ACROSS THE UPPER MIDWEST AND MID AND LOWER MS VALLEY TO
THE GULF OF MEX LATE TONIGHT. THIS RIDGE HAS BEEN MOVING VERY
SLOWLY E FROM THE PLAINS TOWARD THE LOCAL AREA OVER THE LAST FEW
DAYS. WITH ITS CONTINUED GRADUAL DRIFT TO THE E THE RIDGE AXIS IS
FINALLY PROGGED TO MOVE OVER THE LOCAL AREA DURING THIS AFTERNOON
AND EVENING.
WITH THE RIDGE AXIS VERY NEAR OR OVERHEAD THIS AFTERNOON AND
EVENING THE CURRENT LIGHT NW TO NNW LOW LEVEL FLOW WILL WEAKEN
EVEN FURTHER AND BASICALLY BE NIL BY 00Z. WHILE A VERY WEAK LAKE
BREEZE DID DEVELOP WED IT DID NOT MAKE MORE THAN A MILE OR TWO
INLAND. WITH AFTERNOON TEMPERATURES FORECAST SOME 3 TO 5 DEG F
WARMER THAN THOSE REACHED WED AND VERY LITTLE LOW LEVEL FLOW TO
IMPEDE A FURTHER INLAND ADVANCE OF THE LAKE BREEZE DO EXPECT IT
TO REACH MDW AROUND 22Z AND MDW AROUND 23Z SHIFTING LIGHT WINDS
FROM OUT OF THE NNW AND N TO OUT OF THE ENE AND NE.
WITH SUNSET AND LOSS OF HEATING THE BOUNDARY WILL WASH OUT
LEAVING WINDS LIGHT VARIABLE OR NIL AS THE RIDGE AXIS WILL BE
OVERHEAD THROUGH THE NIGHT AS IT IS NOT PROGGED TO REACH THE IL
LAKE SHORE TIL EARLY FRI MORNING.
SURFACE HEATING AND MARGINAL LOW LEVEL MOISTURE MAY GIVE RISE
TO FEW-SCT STRATOCU MID MORNING THROUGH EARLY AFTERNOON THEN
WARMING IN THE 850-800HPA LAYER CREATES TOO LARGE OF A DEW
POINT DEPRESSION TO SUPPORT AND STRATOCU DURING THE LATER THIS
AFTERNOON. OTHERWISE ONLY FEW-SCT CIRRUS RIDING OVER A BROAD
WESTERN UPPER RIDGE REACHING THE LOCAL AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE LAKE BREEZE DEVELOPMENT AGAIN THU AFTERNOON...
MEDIUM CONFIDENCE REGARDING TIMING AT ORD/MDW.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...DRY. VFR. AFTERNOON LAKE BREEZE.
* SATURDAY...DRY/VFR DURING THE DAY THEN MVFR WITH RAIN LIKELY
SATURDAY NIGHT.
* SUNDAY...CHANCE OF RAIN. MVFR POSSIBLE.
* MONDAY AND TUESDAY...DRY. VFR.
&&
.MARINE...
342 AM CDT
A HIGH PRESSURE RIDGE EXTENDING FROM HUDSON BAY S ACROSS THE
UPPER MIDWEST AND MID AND LOWER MS VALLEY TO THE GULF COAST HAS
BEEN MOVING VERY SLOWLY EASTWARD THE LAST FEW DAYS AND WILL
CONTINUE THIS VERY SLOW APPROACH EASTWARD TODAY...WITH THE RIDGE
AXIS FINALLY MOVING OVER LAKE MI TONIGHT. WITH THE RIDGE CLOSE BY
AND EVENTUALLY OVER THE LAKE ONLY LIGHT TO GENTLE BREEZES WILL BE
EXPERIENCED FROM MIDDAY TODAY THROUGH FRIDAY.
WITH THE RIDGE THEN MOVING FURTHER E TO THE LOWER GREAT LAKES AND
THE UPPER OH FRI NIGHT...AND LOW PRESSURE MOVING E ACROSS
NORTHERN MANITOBA TO NORTHERN ONTARIO PUSHING A COLD FRONT
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS WINDS WILL RESULT IN
S TO SW WINDS ESTABLISHING OVERNIGHT FRIDAY AND GRADUALLY
INCREASING TO FRESH SOUTH BREEZES BY SAT AFTERNOON.
THE STRONG COLD FRONT TRAILING SW FROM THE CANADIAN LOW WILL MOVE
ACROSS LAKE MI SUN AND SUN NIGHT LEADING SHIFTING WINDS TO OUT OF
THE W AND NW AND AN INCREASE TO NEAR GALE FORCE OVERNIGHT SUNDAY.
THESE NEAR GALE WINDS WINDS CONTINUE INTO MONDAY AFTERNOON. THERE
IS THE POTENTIAL FOR LOW END GALES ON THE LAKE AFTER THE COLD
FRONT PASSES INTO THE CENTRAL GREAT LAKES LATE SUN NIGHT AND MON
BUT THIS POTENTIAL LOOKS TO BE SMALL AT THIS TIME.
BEHIND THE COLD FRONT HIGH PRESSURE BUILDS FROM SASKATCHEWAN TO
THE CENTRAL PLAINS SUN AND MON. AS THE HIGH MOVES FURTHER TO THE
E ACROSS THE PLAINS NW WINDS ON LAKE MI WILL BEGIN TO GRADUALLY
DIMINISH LATE MONDAY NIGHT AND TUESDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
403 AM CDT THU MAR 28 2013
...UPDATED LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1030 PM CDT WED MAR 27 2013
THE 28.00Z 250 HPA RAOB MAP SHOWED WESTERLY TO NORTHWESTERLY FLOW ACROSS
MUCH OF THE COUNTRY. WIND MAGNITUDES WERE ~50 KT OVER THE PACIFIC NORTHWEST,
~85 KT ACROSS THE KDDC REGION, AND THE STRONGEST WAS ~125+ KT ACROSS
FLORIDA. AT 500 HPA, A DRY NORTHWESTERLY FLOW WAS OBSERVED ACROSS THE
GREAT PLAINS. TEMPERATURES VARIED FROM -10 DEG C AT KBRO TO -24 DEG
C AT KBIS. THE MID LEVEL COLD POOL WITH TEMPERATURES IN THE -30 DEG
C TO -33 DEG C RANGE WAS WELL TO THE NORTHEAST OF SOUTHWEST KANSAS.
AT 700 HPA, THERE WAS A WEAK BAROCLINIC BOUNDARY BETWEEN KDDC (-1 DEG
C) AND KAMA (4 DEG C). AT 850 HPA, A TEMPERATURE GRADIENT CONTINUED
FROM KDDC (7 DEG C) TO KAMA (16 DEG C). SOME LOW LEVEL MOISTURE ADVECTION
WAS NOTED ACROSS FAR SOUTH TEXAS. AT THE SFC, A STATIONARY FRONT WAS
ANALYZED ACROSS THE NORTHERN HIGH PLAINS. THIS BOUNDARY TURNED INTO
A COLD FRONT ACROSS THE SOUTHERN HIGH PLAINS. RELATIVELY HIGHER DEWPOINTS
OF 50+ DEG F WERE CONFINED TO COASTAL SOUTH TEXAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CDT THU MAR 28 2013
THIS MORNING:
IMMEDIATE SHORT TERM CONCERN IS PATCHY FOG ACROSS CENTRAL KANSAS THIS
MORNING. A NORTHEASTERLY UPSLOPE FLOW ALONG WITH SURFACE PRESSURE CONDENSATION
DEFICITS NEAR 0 HPA AND IN COMBINATION WITH BUFR/BUFKIT FORECAST SOUNDING
SPELL THE CONCERN FOR PATCHY FOG NORTHEAST OF A LINE FROM ST. JOHN TO
PENDENNIS. HRRR IS QUITE AGGRESSIVE WITH THE FOG AND SUGGESTING DENSE
FOG (LESS THAN/EQUAL TO QUARTER OF A MILE VISIBILITY) BUT FEEL THIS
MIGHT BE OVERDONE.
TODAY:
A WEAK WARM AIR ADVECTION PATTERN IS EXPECTED TODAY AS A RESULT OF 500
HPA GEOPOTENTIAL HEIGHT INCREASES AND WITH WINDS BECOMING EAST-SOUTHEASTERLY
TONIGHT AS WEAK LEE SURFACE TROUGHING DEEPENS ACROSS COLORADO. FORECAST
SOUNDINGS SHOW A MIXED PROFILE GENERALLY UP TO 750 HPA, WHICH SUPPORTS
MIX DOWN TEMPERATURES IN THE 60S DEG F. PLENTY OF MID TO HIGH LEVEL
CLOUDS IS EXPECTED TODAY AS WATER VAPOR IMAGERY SHOWS MOISTURE ADVECTION
FROM THE ROCKIES AND EVENTUALLY OUT ACROSS THE CENTRAL PLAINS. DELETERIOUS
TEMPERATURE IMPACTS ARE NOT EXPECTED FROM THE AFOREMENTIONED CLOUDS.
TONIGHT:
HAVE A SLIGHT CONCERN FOR OVERNIGHT SHOWERS ACROSS SOUTH CENTRAL KANSAS
IN ASSOCIATION WITH CONTINUED WARM AIR ADVECTION AND WEAK LIFT ALONG
A STATIONARY FRONT. 0-10 KM MUCAPE (DONE TO CAPTURE THE ENTIRE ATMOSPHERIC
COLUMN) FROM THE NAM SHOWS VALUES AROUND 500-700 J/KG ACROSS THIS REGION,
SO CANNOT RULE OUT ISOLATED THUNDER. THE BEST THETA-E ADVECTION IS SOUTH
AND EAST OF THE REGION, SO WILL NOT GET CARRIED AWAY WITH PRECIPITATION
PROBABILITIES OTHER THAN THE SLIGHT CATEGORY. OVERNIGHT LOWS WILL BE
WARMER - 40S DEG F - AS A RESULT OF CLOUD COVER, SOUTHERLY WINDS, AND
SLIGHTLY HIGHER DEWPOINTS (PARTICULARLY ACROSS SC KS).
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 402 AM CDT THU MAR 28 2013
WEST NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE CENTRAL HIGH
PLAINS. LOW LEVEL MOISTURE OVER THE SOUTHERN PLAINS WILL BE
ADVECTING NORTHWARD INTO KANSAS THROUGH THE NEXT FEW DAYS. A FRONTAL
BOUNDARY IS PROGGED TO REMAIN NEARLY STATIONARY ACROSS OKLAHOMA AND
THE TEXAS PANHANDLE INTO EASTERN COLORADO. THE LOW LEVEL MOISTURE
WILL RESULT IN INCREASING LOW CLOUDINESS TO SOUTHWEST KANSAS FRIDAY
INTO FRIDAY NIGHT. MODEL SOUNDINGS SHOW INCREASING MID LEVEL
INSTABILITY AS WELL. SOME MID LEVEL WARM ADVECTION COULD SPAWN A FEW
SHOWERS AND THUNDERSTORMS ON FRIDAY. THUNDERSTORMS COULD ALSO
DEVELOP OVER EASTERN COLORADO FRIDAY AFTERNOON AND MOVE INTO FAR
WESTERN KANSAS LATER IN THE DAY. A SHORTWAVE TROUGH MOVING INTO THE
UPPER MIDWEST WILL PUSH ANOTHER COLD FRONT SOUTH ACROSS WESTERN
KANSAS ON SATURDAY. THIS COULD TRIGGER THUNDERSTORMS AGAIN SATURDAY
AFTERNOON. THERE IS SOME POTENTIAL FOR SEVERE THUNDERSTORMS OVER
SOUTH CENTRAL KANSAS AS CAPE AND SHEAR VALUES INCREASE TO AROUND
1000 J/KG AND 30-40 KNOTS, RESPECTIVELY. DRIER CONDITIONS SHOULD
PREVAIL ON SUNDAY BEHIND THE FRONT.
THE MEDIUM RANGE MODELS CONTINUE TO SHOW A STRONG UPPER LEVEL LOW
PRESSURE SYSTEM DIGGING SOUTH OUT OF CANADA INTO THE GREAT LAKES
REGION WITH NEARLY MERIDIONAL FLOW DEVELOPING OVER THE NORTHERN
PLAINS. THIS WILL PUSH A STRONG COLD FRONT SOUTH ACROSS THE CENTRAL
PLAINS SUNDAY NIGHT WITH MUCH COLDER TEMPERATURES WILL BE PUSHING
SOUTH BEHIND THE FRONT. THERE WILL BE CHANCES FOR SHOWERS AND
ISOLATED THUNDERSTORMS WITH THE FRONT. THE RAIN SHOULD MIX WITH OR
CHANGE OVER TO LIGHT SNOW LATE SUNDAY NIGHT INTO MONDAY AS THE
COLDER AIR MOVES IN. HAVE LOWERED HIGH TEMPERATURES ON MONDAY INTO
THE 30S WITH LOW 40S ALONG THE OKLAHOMA BORDER. HIGHS ON TUESDAY
WILL CONTINUE TO BE ON THE COOL SIDE...STAYING MAINLY IN THE 40S.
WARMER WEATHER WILL RETURN TO THE CENTRAL PLAINS BY MID WEEK AS
TEMPERATURES CLIMB BACK INTO THE 50S AND 60S BY WEDNESDAY AND
THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1200 AM CDT THU MAR 28 2013
MAIN CONCERN FOR TAFS IS POSSIBLE MVFR CIGS ACROSS CENTRAL KANSAS THIS
MORNING. BUFR/BUFKIT THERMODYNAMIC PROFILES SUGGEST BR FOR KHYS. THIS
IS ALSO SUPPORTED VIA HRRR/LAMP GUIDANCE/ARW-NMM MODELS. CONFIDENCE
IS LOWER FARTHER SW TOWARDS KDDC, SO WILL LEAVE OUT FOR NOW. OTHERWISE,
SOME CIRRIFORM CLOUDS EXPECTED THROUGH TAF PD. WINDS WILL EVENTUALLY
VEER FROM NORTHEASTERLY TO EASTERLY/EAST-SOUTHEASTERLY LATER TODAY AS
HIGH PRESSURE SHIFTS EASTWARD. MAGNITUDE OF WIND VECTOR 5-10 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 43 65 48 / 10 10 30 20
GCK 64 41 65 46 / 10 10 20 20
EHA 64 42 68 46 / 10 10 20 20
LBL 64 44 67 48 / 10 10 20 20
HYS 62 39 64 47 / 10 10 20 20
P28 65 47 63 51 / 10 20 40 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
250 AM CDT THU MAR 28 2013
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1030 PM CDT WED MAR 27 2013
THE 28.00Z 250 HPA RAOB MAP SHOWED WESTERLY TO NORTHWESTERLY FLOW ACROSS
MUCH OF THE COUNTRY. WIND MAGNITUDES WERE ~50 KT OVER THE PACIFIC NORTHWEST,
~85 KT ACROSS THE KDDC REGION, AND THE STRONGEST WAS ~125+ KT ACROSS
FLORIDA. AT 500 HPA, A DRY NORTHWESTERLY FLOW WAS OBSERVED ACROSS THE
GREAT PLAINS. TEMPERATURES VARIED FROM -10 DEG C AT KBRO TO -24 DEG
C AT KBIS. THE MID LEVEL COLD POOL WITH TEMPERATURES IN THE -30 DEG
C TO -33 DEG C RANGE WAS WELL TO THE NORTHEAST OF SOUTHWEST KANSAS.
AT 700 HPA, THERE WAS A WEAK BAROCLINIC BOUNDARY BETWEEN KDDC (-1 DEG
C) AND KAMA (4 DEG C). AT 850 HPA, A TEMPERATURE GRADIENT CONTINUED
FROM KDDC (7 DEG C) TO KAMA (16 DEG C). SOME LOW LEVEL MOISTURE ADVECTION
WAS NOTED ACROSS FAR SOUTH TEXAS. AT THE SFC, A STATIONARY FRONT WAS
ANALYZED ACROSS THE NORTHERN HIGH PLAINS. THIS BOUNDARY TURNED INTO
A COLD FRONT ACROSS THE SOUTHERN HIGH PLAINS. RELATIVELY HIGHER DEWPOINTS
OF 50+ DEG F WERE CONFINED TO COASTAL SOUTH TEXAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CDT THU MAR 28 2013
THIS MORNING:
IMMEDIATE SHORT TERM CONCERN IS PATCHY FOG ACROSS CENTRAL KANSAS THIS
MORNING. A NORTHEASTERLY UPSLOPE FLOW ALONG WITH SURFACE PRESSURE CONDENSATION
DEFICITS NEAR 0 HPA AND IN COMBINATION WITH BUFR/BUFKIT FORECAST SOUNDING
SPELL THE CONCERN FOR PATCHY FOG NORTHEAST OF A LINE FROM ST. JOHN TO
PENDENNIS. HRRR IS QUITE AGGRESSIVE WITH THE FOG AND SUGGESTING DENSE
FOG (LESS THAN/EQUAL TO QUARTER OF A MILE VISIBILITY) BUT FEEL THIS
MIGHT BE OVERDONE.
TODAY:
A WEAK WARM AIR ADVECTION PATTERN IS EXPECTED TODAY AS A RESULT OF 500
HPA GEOPOTENTIAL HEIGHT INCREASES AND WITH WINDS BECOMING EAST-SOUTHEASTERLY
TONIGHT AS WEAK LEE SURFACE TROUGHING DEEPENS ACROSS COLORADO. FORECAST
SOUNDINGS SHOW A MIXED PROFILE GENERALLY UP TO 750 HPA, WHICH SUPPORTS
MIX DOWN TEMPERATURES IN THE 60S DEG F. PLENTY OF MID TO HIGH LEVEL
CLOUDS IS EXPECTED TODAY AS WATER VAPOR IMAGERY SHOWS MOISTURE ADVECTION
FROM THE ROCKIES AND EVENTUALLY OUT ACROSS THE CENTRAL PLAINS. DELETERIOUS
TEMPERATURE IMPACTS ARE NOT EXPECTED FROM THE AFOREMENTIONED CLOUDS.
TONIGHT:
HAVE A SLIGHT CONCERN FOR OVERNIGHT SHOWERS ACROSS SOUTH CENTRAL KANSAS
IN ASSOCIATION WITH CONTINUED WARM AIR ADVECTION AND WEAK LIFT ALONG
A STATIONARY FRONT. 0-10 KM MUCAPE (DONE TO CAPTURE THE ENTIRE ATMOSPHERIC
COLUMN) FROM THE NAM SHOWS VALUES AROUND 500-700 J/KG ACROSS THIS REGION,
SO CANNOT RULE OUT ISOLATED THUNDER. THE BEST THETA-E ADVECTION IS SOUTH
AND EAST OF THE REGION, SO WILL NOT GET CARRIED AWAY WITH PRECIPITATION
PROBABILITIES OTHER THAN THE SLIGHT CATEGORY. OVERNIGHT LOWS WILL BE
WARMER - 40S DEG F - AS A RESULT OF CLOUD COVER, SOUTHERLY WINDS, AND
SLIGHTLY HIGHER DEWPOINTS (PARTICULARLY ACROSS SC KS).
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 331 PM CDT WED MAR 27 2013
HAVING BEEN SUPPRESSED INTO THE TROPICS BY A PREVIOUS FRONTAL
INCURSION, SOME LIMITED LOW LEVEL MOISTURE WILL BEGIN TO MOVE NORTHWARD
INTO THE PLAINS BY FRIDAY. THIS IS THE RESULT OF ZONAL FLOW ACROSS
THE SOUTHERN ROCKIES AT MID LEVELS, WHICH WILL CAUSE LEE TROUGHING
AND WARM ADVECTION. ALSO, A SURFACE FRONT WILL DEVELOP ACROSS THE
SOUTHERN PLAINS, WITH WARM ADVECTION NORTH OF THIS BOUNDARY. ANY
SURFACE BASED CONVECTION WILL STAY SOUTH OF KANSAS ALONG THE
FRONT. A FEW SHOWERS ARE POSSIBLE FRIDAY AND FRIDAY NIGHT, WITH
THE BEST CHANCES IN SOUTH CENTRAL KANSAS. BY SATURDAY AND INTO
SUNDAY, A DEEP UPPER LEVEL TROUGH WILL MOVE SOUTHWARD FROM CANADA
INTO THE NORTHERN PLAINS AND GREAT LAKES. THIS WILL TEND TO SHUNT
THE LOW LEVEL MOISTURE SOUTHEASTWARD AND AWAY FROM WESTERN KANSAS,
WITH ONLY VERY SLIGHT CHANCES FOR RAIN. MEANWHILE, BY SUNDAY,
UPPER LEVEL TROUGHING WILL DEVELOP NEAR THE CALIFORNIA COAST. BUT
THE LARGE UPPER LEVEL TROUGH DIGGING INTO THE GREAT LAKES WILL
TEND TO BLOCK THE EASTERLY MOVEMENT OF THE WEST COAST TROUGH. SO
INSTEAD OF HAVING A ROBUST SHORTWAVE TROUGH APPROACHING THE HIGH
PLAINS MONDAY AND TUESDAY AS THE MODELS PREVIOUSLY ADVERTISED,
THIS SYSTEM WILL TEND TO SHEAR OUT AND WEAKEN AS IT MOVES
EASTWARD, AND WILL BE SUPPRESSED SOUTHWARD A BIT. COLD AIR
ASSOCIATED WITH THE LARGE NORTHERN PLAINS/GREAT LAKES TROUGH WILL
SURGE INTO WESTERN KANSAS MONDAY. SOME MID LEVEL WARM ADVECTION
WILL DEVELOP NORTH OF THE FRONT BY LATE SUNDAY NIGHT INTO MONDAY
AND MONDAY NIGHT. THIS PRECIPITATION MAY START OUT AS RAIN AND
THEN CHANGE TO SNOW. HOWEVER, THIS WILL PROBABLY NOT BE A MAJOR
PRECIPITATION EVENT SINCE THE APPROACHING UPPER LEVEL TROUGH WILL
NOT BE ROBUST ENOUGH AND FAR ENOUGH NORTH TO PRODUCE HEAVIER
PRECIPITATION. COLDER TEMPERATURES CAN BE EXPECTED MONDAY AND
TUESDAY WITH HIGHS IN THE 30S/40S AND LOWS IN THE 20S.
TEMPERATURES SHOULD MODERATE BY THE MIDDLE OF NEXT WEEK AND INTO
NEXT WEEKEND AS THE AFOREMENTIONED UPPER LEVEL TROUGH OVER THE
GREAT LAKES REGION MOVES FURTHER EAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1200 AM CDT THU MAR 28 2013
MAIN CONCERN FOR TAFS IS POSSIBLE MVFR CIGS ACROSS CENTRAL KANSAS THIS
MORNING. BUFR/BUFKIT THERMODYNAMIC PROFILES SUGGEST BR FOR KHYS. THIS
IS ALSO SUPPORTED VIA HRRR/LAMP GUIDANCE/ARW-NMM MODELS. CONFIDENCE
IS LOWER FARTHER SW TOWARDS KDDC, SO WILL LEAVE OUT FOR NOW. OTHERWISE,
SOME CIRRIFORM CLOUDS EXPECTED THROUGH TAF PD. WINDS WILL EVENTUALLY
VEER FROM NORTHEASTERLY TO EASTERLY/EAST-SOUTHEASTERLY LATER TODAY AS
HIGH PRESSURE SHIFTS EASTWARD. MAGNITUDE OF WIND VECTOR 5-10 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 43 65 48 / 10 10 20 20
GCK 64 41 65 46 / 10 10 20 20
EHA 64 42 68 46 / 10 10 30 20
LBL 64 44 67 48 / 10 10 20 20
HYS 62 39 64 47 / 10 10 20 20
P28 65 47 63 51 / 10 20 30 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...FINCH
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
410 AM CDT THU MAR 28 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CDT THU MAR 28 2013
PRIMARY FORECAST LIES WITH TEMPERATURES AND FOG POTENTIAL.
QUIET CONDITIONS IN PLACE EARLY THIS MORNING...WITH UPPER AIR
PROFILER AND SATELLITE DATA SHOWING SLIGHT NORTHWESTERLY FLOW SET
UP OVER THE REGION...AS WEAK RIDGING SITS OVER THE ROCKIES AND
LOW PRESSURE/TROUGHING AFFECTS THE NORTHEASTERN CONUS. OUTSIDE OF
SOME MID/UPPER LEVEL CLOUDS GRADUALLY CREEPING EAST FROM THE HIGH
PLAINS AND ROCKIES...SKIES ACROSS THE CWA ARE CLEAR. THE SURFACE
PATTERN OVER THE CENTRAL PLAINS REMAINS WEAK...WITH HIGH PRESSURE
EXTENDING FROM ONTARIO TO THE GULF COAST...WHILE A STATIONARY
BOUNDARY LIES ALONG THE FRONT RANGE OF THE ROCKIES...RESULTING IN
CONTINUED LIGHT AND VARIABLE WINDS ACROSS THE CWA. REALLY HASNT
BEEN AT ANY HINTS OF FOG DEVELOPMENT YET THIS MORNING...BUT SOME
THE HRRR ESP CONTINUES TO SHOW THE POTENTIAL CLOSER TO
SUNRISE...SO WILL CONTINUE TO KEEP THE PATCHY MENTION GOING IN THE
FORECAST FOR THIS MORNING.
LOOKING AT THE REST OF THE SHORT TERM FORECAST...IT REMAINS A DRY
ONE WITH NO NOTABLE CHANGES OVERALL IN THE UPPER LEVEL PATTERN.
SRN PORTIONS OF THE CWA WONT BE TOO TERRIBLY FAR AWAY FROM
PRECIPITATION FORECAST OVER CENTRAL KS OVERNIGHT TONIGHT ALONG A
SFC WARM FRONT AS AN UPPER LEVEL DISTURBANCE PASSES THROUGH...ALSO
AIDED BY AN INCREASE LLJ. AT THE SURFACE...AGAIN NOT EXPECTING ANY
SIGNIFICANT CHANGES...REMAINING FAIRLY WEAK AND KEEPING WINDS
GENERALLY E/SERLY. SHOULD SEE A BUMP UP IN SPEEDS DURING THE
DAYTIME HOURS TODAY INTO THE 10 TO 15 MPH RANGE...BUT WILL LIKELY
DIE OFF AGAIN THIS EVENING/OVERNIGHT WITH A BOUNDARY LOOKING TO
SET UP OVER THE CWA. THIS IS AGAIN SOME CONCERN FOR SOME FOG
TONIGHT...WITH THE LIGHT WINDS RETURNING...BUT CONFIDENCE IS NOT
HIGH IN ITS OCCURRENCE...SO KEPT IT ONLY A PATCHY MENTION.
DEPENDING ON HOW THE REST OF THIS MORNING GOES AND WITH 12Z
MODELS...DAY SHIFT MAY BE ABLE TO REMOVE IT FROM THE FORECAST.
AS FAR AS TEMPERATURES GO...SOME GUIDANCE AND MODELS THE LAST
COUPLE OF DAYS HAVE REALLY UNDERDONE HIGHS...AND AM CONCERNED IT
MAY HAPPEN AGAIN TODAY...THOUGH MAYBE NOT QUITE TO THE EXTENT OF
PREVIOUS DAYS. STICKING CLOSER TO THE NAM/MET/ECMWF FOR TODAYS
HIGHS...YESTERDAY HAD LITTLE PROBLEM GETTING INTO THE MID
50S...AND WITH A GENERALLY SIMILAR SET UP TODAY BUT A SLIGHT
INCREASE IN TEMPS ALOFT...FELT THAT UPPER 50S/LOWER 60S WAS
REASONABLE. MAY BE A FEW MORE CLOUDS AROUND TODAY...AND AT THIS
POINT DONT FEEL IT WILL HOLD BACK TEMPS SIGNIFICANTLY...BUT IT
WILL BE SOMETHING FOR THE DAY SHIFT TO KEEP A CLOSE EYE ON.
OVERNIGHT LOWS TONIGHT LOOK TO COOL INTO THE MID 30S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 409 AM CDT THU MAR 28 2013
GUIDANCE SUGGESTS THE LONG TERM FORECAST PERIOD WILL BE DOMINATED
BY NORTHWESTERLY MID AND UPPER LEVEL FLOW. CHANCES FOR
PRECIPITATION ARE SPRINKLED THROUGHOUT THE LONG TERM FORECAST
PERIOD...THE FIRST OF WHICH PRESENTS ITSELF LATE FRIDAY AFTERNOON.
AN OVERALL LACK IN KINEMATIC FORCING WOULD OTHERWISE PRESENT DRY
CONDITIONS TO THE AREA ON FRIDAY...HOWEVER FORECAST PROXIMITY
SOUNDINGS...PER THE NAM AND OPERATIONAL GFS...SUGGEST WESTERN
PORTIONS OF OUR CWA...PRIMARILY WEST OF HIGHWAY 183...WILL REACH A
CONVECTIVE TEMPERATURE IN THE LOWER 60S. SHOULD CONVECTIVE
INITIATION BE REALIZED LATE FRIDAY AFTERNOON...THESE SAME
PROXIMITY SOUNDINGS SUGGEST 200-500J/KG SBCAPE WILL BE READY FOR
UPDRAFT PRODUCTION. FARTHER EAST ACROSS OUR CWA IT APPEARS A LOW
LEVEL CAPPING INVERSION WILL KEEP CONVECTION AT BAY...BUT GIVEN
THE THREAT FOR CONVECTION FARTHER WEST...OPTED TO KEEP THE SLIGHT
CHANCE POPS INHERITED FROM THE PREVIOUS FORECAST. GIVEN THE
AFOREMENTIONED INSTABILITY AND THE FAIRLY LOW FREEZING
HEIGHTS...WILL GO AHEAD AND CONTINUE HIGHLIGHTING SMALL HAIL IN
THE HWO FOR FRIDAY AFTERNOON.
SURFACE-BASED CONVECTION ACROSS OUR WEST FRIDAY AFTERNOON...SHOULD
IT BE REALIZED...WILL QUICKLY DISSIPATE TOWARDS SUNSET AS
DIABATIC HEATING IS LOST ACROSS THE AREA. THAT BEING
SAID...ADDITIONAL PRECIPITATION WILL BE POSSIBLE ACROSS MOST ALL
OF OUR CWA FRIDAY NIGHT INTO EARLY SATURDAY MORNING AS THE AXIS OF
A 25-30KT LOW LEVEL JET STREAK SETS UP ACROSS THE AREA. AT THIS
TIME IS APPEARS THE NOSE OF THIS LOW LEVEL JET STREAK WILL BE
REALIZED ACROSS NORTHEASTERN NEBRASKA INTO PORTIONS OF SOUTH
DAKOTA. WITH THE RESULTANT AREA OF LOW LEVEL CONVERGENCE ALSO
EXPECTED TO RESIDE NORTH OF OUR AREA...QPF FIELDS FROM MOST MODELS
KEEP THE HEAVIEST PRECIPITATION ON FRIDAY NIGHT TO OUR
NORTH/NORTHEAST. THAT BEING SAID IT STILL APPEARS THERE WILL BE
ENOUGH LOW LEVEL THERMAL ADVECTION ALONG THE LOW LEVEL JET AXIS
FOR PRECIPITATION PRODUCTION ACROSS MOST ALL OF OUR CWA. WENT
AHEAD WITH 30%-50% POPS ACROSS OUR NORTH/NORTHEAST FRIDAY
NIGHT/SATURDAY MORNING...CLOSER TO THE NOSE OF THE LOW LEVEL
JET...WITH POPS CLOSER TO 20% FARTHER SOUTH/SOUTHWEST ACROSS OUR
CWA.
THERE MAY BE SOME LINGERING CONVECTION ALONG THE LOW LEVEL JET
AXIS AROUND OR JUST AFTER SUNRISE SATURDAY...HOWEVER THIS
ACTIVITY SHOULD WANE AS THE LOW LEVEL JET DECREASES IN INTENSITY.
WENT AHEAD AND KEPT 20%-30% POPS GOING ACROSS MUCH OF OUR CWA 12Z-
18Z SATURDAY AS A RESULT. THE PASSAGE OF A SUBTLE MID LEVEL SHORT
WAVE ACROSS THE NORTHERN PLAINS IS EXPECTED TO HELP PUSH A LOW
LEVEL BAROCLINIC ZONE ACROSS OUR AREA DURING THE DAY SATURDAY AND
WHILE MUCH OF OUR AREA SHOULD BE DRY ON SATURDAY FOLLOWING THE
DISSIPATION OF MORNING CONVECTION...THERE IS SOME CONCERN THAT
THERE COULD BE ADDITIONAL AFTERNOON CONVECTION ALONG THE LOW LEVEL
BAROCLINIC ZONE ACROSS OUR SOUTH. GIVEN THIS...WENT AHEAD AND KEPT
~20% POPS GOING ACROSS OUR SOUTH. FORECAST PROXIMITY SOUNDINGS
FROM ACROSS OUR SOUTH SUGGEST 200-400J/KG 0-1MLCAPE VALUES COULD
BE REALIZED SATURDAY AFTERNOON AND MUCH LIKE FRIDAY
AFTERNOON...WILL CONTINUE TO HIGHLIGHT THE CHANCE FOR SMALL HAIL
IN THE HWO. ONCE THE LOW LEVEL BAROCLINIC ZONE DOES CLEAR OUR AREA
SATURDAY...DRY CONDITIONS ARE THEN EXPECTED SATURDAY NIGHT AS AN
OVERALL LACK IN KINEMATIC FORCING OVERTAKES THE AREA.
THE PERIOD OF DRY CONDITIONS WILL BE SHORT-LIVED HOWEVER AS A MID
LEVEL SHORT WAVE ADVANCES SOUTHEAST OUT OF CANADA AND ACROSS THE
UPPER MISSISSIPPI VALLEY...PERHAPS CLIPPING PORTIONS OF THE
NORTHERN AND CENTRAL PLAINS...NEXT MONDAY INTO TUESDAY. DPVA AND
MID LEVEL THERMAL ADVECTION AHEAD OF THE MID LEVEL TROUGH AXIS IS
EXPECTED TO REMAIN EAST/NORTHEAST OF OUR AREA WHICH WOULD
OTHERWISE SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL ALSO
REMAIN EAST/NORTHEAST OF OUR AREA. THAT WONT BE THE CASE HOWEVER
AS A 90-100KT MID LEVEL JET STREAK ACCOMPANIES THE SHORT WAVE
ACROSS PORTIONS OF THE REGION. THE RIGHT-REAR QUADRANT OF THIS MID
LEVEL JET STREAK IS EXPECTED MOVE OVER OUR AREA SUNDAY THROUGH
MONDAY...WITH ENOUGH OF A DIRECT THERMAL CIRCULATION AND RESULTANT
OMEGA FOR PRECIPITATION PRODUCTION ACROSS MOST ALL OF OUR CWA.
ALLBLEND PROVIDED A WIDE RANGE OF POPS DURING THIS 36-HOUR
PERIOD...RANGING FROM ~20% TO ~50%...WITH THE HIGHEST POPS
CURRENTLY FORECAST SUNDAY NIGHT. SAW LITTLE REASON TO DISAGREE
WITH ALLBLEND AND THUS LEFT THESE POPS UNCHANGED. FORECAST
PROXIMITY SOUNDINGS FROM ACROSS THE CWA...PER THE OPERATIONAL GFS
AND EC...SUGGEST THE LOWER TROPOSPHERE SHOULD BE WARM ENOUGH FOR
RAIN DURING THE DAY SUNDAY. WITH CONTINUED LOW LEVEL COLD AIR
ADVECTION HOWEVER A TRANSITION TO SNOWFALL IS APPEARING MORE AND
MORE LIKELY ACROSS MOST ALL OF THE CWA SUNDAY NIGHT AND INTO THE
DAY MONDAY. QPF FIELDS FROM THE OPERATIONAL GFS AND EC BOTH
SUGGEST A COUPLE TENTHS OF AN INCH OF LIQUID PRECIPITATION COULD
BE REALIZED FROM THIS SYSTEM...WHICH SEEMS REASONABLE GIVEN
SUFFICIENT LOWER TROPOSPHERIC MOISTURE WILL BE IN PLACE AND OMEGA
VALUES APPROACHING 10-UBAR/S. GIVEN ALL THIS ONE MIGHT SUSPECT AN
INCH OR TWO OF SNOW ACCUMULATION COULD BE REALIZED SUNDAY NIGHT
INTO MONDAY...BUT SINCE WE ARE NOW APPROACHING EARLY APRIL AND THE
SUN ANGLE IS SO HIGH...IT SEEMS HIGHLY UNLIKELY MUCH OF ANY
ACCUMULATION WILL BE REALIZED AS MUCH OF THE SNOWFALL SHOULD MELT
ON CONTACT WITH THE WARM SURFACE. SO...DESPITE THIS BEING A LATE-
SEASON SNOW EVENT...LITTLE IN THE WAY OF IMPACTS ARE CURRENTLY
EXPECTED ACROSS THE CWA AND WILL LEAVE ANY SUCH WORDING OUT OF THE
HWO. AN OVERALL LACK IN KINEMATIC FORCING SHOULD THEN PROVIDE DRY
CONDITIONS TO OUR AREA MONDAY NIGHT THROUGH THE END OF THE CURRENT
FORECAST PERIOD.
TEMPERATURES IN THE 50S AND 60S ARE STILL EXPECTED FRIDAY THROUGH
SUNDAY...WITH A COOLING TREND PUSHING HIGHS DOWN INTO THE 30S
MONDAY...FOLLOWED BY AFTERNOON HIGHS IN THE 40S AND 50S TO FINISH
THE FORECAST PERIOD. OVERNIGHT LOWS IN THE 30S AND 40S SHOULD BE
OBSERVED FRIDAY NIGHT AND SATURDAY NIGHT...WITH COOLER AIR THEN
PRESENTING OVERNIGHT LOWS IN THE 20S ACROSS MUCH OF THE AREA
SUNDAY NIGHT...IN THE TEENS AND 20S MONDAY NIGHT...AND THEN BACK
INTO THE 20S AND 30S TO FINISH THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1204 AM CDT THU MAR 28 2013
QUIET WEATHER FORECAST FOR THIS PERIOD...WITH THE PRIMARY CONCERN
LYING WITH FOG POTENTIAL LATER TONIGHT. SKIES ARE CURRENTLY
CLEAR...BUT CLOUDS ARE EXPECTED TO INCREASE TO BRING AT LEAST
PARTLY CLOUDY SKIES THROUGH THE PERIOD...ESP IN THE MID/UPPER
LEVELS AND DURING THE LATE MORNING/AFTERNOON HOURS. A CONTINUED
WEAK SURFACE PATTERN IS KEEPING WINDS GENERALLY EASTERLY BUT VERY
LIGHT IN SPEEDS...WHICH WILL REMAIN THROUGH THE REST OF THE
OVERNIGHT HOURS. WONT SEE A NOTABLE CHANGE IN DIRECTION THROUGH
THE TAF PERIOD...THOUGH WINDS SHOULD BUMP UP CLOSER TO 10 MPH
DURING THE DAY. AS FAR AS FOG GOES...CONTINUED THE MVFR MENTION
GOING IN THE TAF...WITH WINDS REMAINING LIGHT AND PLENTY OF
COOLING GOING ON. DIDNT DECREASE VISIBILITIES ANY MORE...COMPARED
TO 24 HRS AGO MODELS HAVE BACKED OFF ON THE EXTENT OF ANY
FOG...BUT WILL BE KEEPING A CLOSE EYE ON ITS DEVELOPMENT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADO
LONG TERM...BRYANT
AVIATION...ADO
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
324 AM CDT THU MAR 28 2013
.DISCUSSION...
NO SIGNIFICANT CHANGES MADE TO GOING FCST THIS MORNING. MAIN
CONCERNS CONTINUE TO BE POSSIBLE PCPN ACCOMPANYING COLDER AIR MASS
SWEEPING IN THIS WEEKEND. BEFORE THEN...MODEST HGT RISES SPREADING OVER
THE PLAINS WILL RESULT IN LONG-AWAITED WARM UP OVER THE NEXT
SEVERAL DAYS. MET/MAV HIGHS PROBABLY A TAD ON THE COOL SIDE TODAY
THRU SAT...SO WILL ADJUST UP A BIT. FRI NIGHT...LEADING EDGE OF
CHILLY CANADIAN AIR MASS WILL BE PRESSING DEEP INTO THE CNTRL
PLAINS. EXPECT PCPN ACTIVITY ALONG MID LVL FRONTOGENETIC AXIS WILL
CROSS INTO THE CWA FRIDAY EVENING...THEN SPREAD OVER THE REST OF
THE CWA SAT MORNING. TPI VALUES INDICATE ENOUGH INSTABILITY WILL
BE PRESENT TO KICK OFF SOME THUNDER. THE BOTTOM DROPS OUT THEN
SUNDAY NIGHT WHEN RE-ENFORCING SHOT OF CAA SWEEPS INTO THE CNTRL
PLAINS. MODELS ARE IN VERY GOOD AGREEMENT MAGNITUDE OF
AGEOSTROPHIC FORCING WILL BE MUCH GREATER...AND MOST PREVALENT
SOUTH OF THE I-80 CORRIDOR. AS OF NOW IT APPEARS THAT THE CAA WILL
BE INTENSE ENOUGH TO PRODUCE A PCPN MIX OF RA/SN SUNDAY NIGHT. AS
FOR TEMPS...EXPECT MONDAY WILL BE THE COLDEST. MATTER OF
FACT...ECM MOS/MEX HAVE BEEN PROGRESSIVELY DROPPING TEMPS MONDAY.
BOTH ARE NO0W IN GOOD AGREEMENT ADVERTISING MON HIGHS STRUGGLING
TO REACH 40. OTHERWISE DRY THRU THE REST OF THE FCST PD WITH TEMPS
WARMING IN RESPONSE TO RIDGE BUILDING IN FROM THE WEST.
DEE
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
WEAK SOUTHEAST FLOW MAY RESULT IN SOME PATCHY FOG
OVERNIGHT AND MVFR VSBYS POSSIBLE THURSDAY MORNING. CONTINUED A
TEMPO FOG MENTION IN THE MORNING. RAP TENDED TO FOCUS MORE SOUTH
OF THE TAF SITES TOWARD THE KANSAS BORDER...BUT WITH FEW CLOUDS
AND WEAK FLOW COULD SEE SOME PATCHY FOG. VFR SKY CONDITIONS SHOULD
CONTINUE OVERNIGHT. SOME PASSING SCT-BKN MID CLOUDS FL100-150
THURSDAY.
CZ
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1150 PM CDT WED MAR 27 2013
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
WEAK SOUTHEAST FLOW MAY RESULT IN SOME PATCHY FOG
OVERNIGHT AND MVFR VSBYS POSSIBLE THURSDAY MORNING. CONTINUED A
TEMPO FOG MENTION IN THE MORNING. RAP TENDED TO FOCUS MORE SOUTH
OF THE TAF SITES TOWARD THE KANSAS BORDER...BUT WITH FEW CLOUDS
AND WEAK FLOW COULD SEE SOME PATCHY FOG. VFR SKY CONDITIONS SHOULD
CONTINUE OVERNIGHT. SOME PASSING SCT-BKN MID CLOUDS FL100-150
THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 317 PM CDT WED MAR 27 2013/
DISCUSSION...
THREE MAJOR UPPER LEVEL LOWS WILL PLAY ROLES IN THE FORECAST
THROUGH THE MIDDLE OF NEXT WEEK. THE FIRST IS OFF THE EASTERN
CANADIAN COAST WITH A TROUGH EXTENDING THROUGH NEW ENGLAND INTO
THE GREAT LAKES. THE SECOND IS A LOW OVER ALASKA AND THE NORTHWEST
TERRITORIES. AND THE THIRD WAS DEVELOPING IN THE SOUTHERN GULF OF
ALASKA. AS THE NEW ENGLAND TROUGH ROTATES OFF THE EAST COAST
AROUND THE FIRST LOW...AND THE THIRD LOW DROPS SOUTH FROM THE GULF
OF ALASKA...GRADUALLY RISING HEIGHTS WILL ENSUE ACROSS THE MIDDLE
OF THE COUNTRY THROUGH AT LEAST FRIDAY. THIS SIGNALS WARMING
TEMPERATURES FOR OUR AREA THE REMAINDER OF THE WEEK.
THE SECOND LOW WILL SLOWLY DRIFT ACROSS NORTHERN CANADA THROUGH
SATURDAY BEFORE DROPPING SOUTHEAST INTO THE NORTHERN GREAT LAKES
EARLY NEXT WEEK. A SIGNIFICANT SHORTWAVE TROUGH WILL RACE SOUTHEAST
THROUGH THE ROCKIES AND INTO THE PLAINS SATURDAY AHEAD OF THIS
LOW...DRIVING A COLD FRONT THROUGH THE MIDDLE OF THE COUNTRY. A
CHANCE FOR PRECIPITATION AND SLIGHTLY COOLER TEMPERATURES WILL
RESULT FROM THIS FEATURE.
AS THE SECOND LOW MOVES INTO THE GREAT LAKES MONDAY...A SECONDARY
COLD PUSH WILL OVERSPREAD THE NORTHERN AND CENTRAL PLAINS...BRINGING
MUCH COLDER TEMPERATURES BACK INTO THE FORECAST. THEN MODELS ARE
STARTING TO CONVERGE ON THE MOVEMENT/TIMING OF LOW NUMBER
THREE...MOVING IT THROUGH THE FOUR CORNERS REGION TUESDAY WHILE
MAINTAINING NORTHWEST FLOW ACROSS OUR AREA THROUGH WEDNESDAY.
TONIGHT THROUGH FRIDAY...GENERAL SOUTHERLY FLOW WILL RETURN TO
THE REGION AHEAD OF SLOWLY DEEPENING LOW PRESSURE IN THE LEE OF
THE ROCKIES. LOW CLOUDS MAY DEVELOP BOTH TONIGHT AND THURSDAY
NIGHT AS LOW LEVEL THETA-E ADVECTION INCREASES. LOW LEVEL RH PROGS
SUGGEST WESTERN SECTIONS OF OUR CWA WILL SEE THE HIGHEST CHANCE
FOR LOWER CLOUDS TONIGHT...WITH ALL OF OUR AREA FRIDAY MORNING.
HOWEVER LOWER CLOUDS SHOULD BE SHORT-LIVED EACH MORNING WITH
PLENTY OF SUNSHINE EXPECTED IN THE AFTERNOONS. SOME WARM ADVECTION
MID CLOUDS ARE LIKELY IN OUR NORTH THURSDAY AFTERNOON AND
NIGHT...AND COULD SQUEEZE OUT A FEW SPRINKLES. OTHERWISE EXPECT
HIGHS TO REACH THE 50S THURSDAY AND PERHAPS 60 FRIDAY GIVEN RISING
HEIGHTS AND WARMER AIRMASS PUSHING INTO THE REGION.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...COLD FRONT WILL SWEEP THROUGH
OUR AREA ON SATURDAY...WITH MOST MODELS SUGGESTING WIND SHIFT WILL
BE EAST OF THE CWA BY EARLY EVENING. WARM/MOIST ADVECTION FRIDAY
NIGHT WILL SPREAD WEAK ELEVATED INSTABILITY ACROSS SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA...BUT CONVERGENCE TO GET PRECIP GOING IS
TOUGH TO NAIL DOWN UNTIL FRONT APPROACHES SATURDAY. SO WILL
MAINTAIN A SMALL CHANCE FOR ELEVATED SHOWERS/STORMS FOR A GOOD
PART OF THE AREA FRIDAY NIGHT...AND KEEP LIKELY CHANCES FOR
SHOWERS/STORMS SATURDAY. GFS FORECAST SOUNDINGS SHOW 300-900 J/KG
OF SKINNY CAPE SUGGESTING AT LEAST ISOLATED RUMBLES COULD OCCUR.
LINGERING SHOWERS MAY AFFECT OUR SOUTHEAST SATURDAY NIGHT...BUT
MOST OF THE NIGHT AND SUNDAY SHOULD BE DRY. HIGHS SATURDAY WILL BE
AFFECTED BY INCREASING CLOUDS...BUT A WARMER START IN THE 40S WILL
ALLOW HIGHS TO REBOUND BACK INTO THE 50S OR LOWER 60S. AND DESPITE
A CHANGE TO NORTHERLY WINDS SUNDAY...ONLY WEAK COOL ADVECTION AND
PLENTY OF SUNSHINE SUGGEST HIGHS REBOUNDING FROM MORNING LOWS IN
THE 30S BACK INTO THE 50S. THERE IS ONE CAVEAT FOR SUNDAY
AFTERNOON. GFS SHOWS A SHORTWAVE/JET SEGMENT KNIFING INTO THE
REGION...AND PRODUCING A SIGNIFICANT SWATH OF PRECIPITATION LATE
IN THE DAY AND EVENING...WITH 850 TEMPERATURES AND COOLING
SOUNDINGS SUGGESTING A GOOD PART OF THAT PRECIPITATION COULD
BECOME SNOW LATE IN THE DAY. NEW 12Z ECMWF ALSO SHOWS
PRECIPITATION BUT IS LEST ROBUST. AM NOT GOING TO ALTER CURRENT
FORECAST TOO FAR FROM THE CHANCE FOR RAIN OR SNOW SUNDAY
NIGHT...BUT THIS BEARS WATCHING.
MONDAY THROUGH WEDNESDAY...SECONDARY COLD FRONT SHOULD USHER IN EVEN
COLDER AIR MONDAY MORNING...WHICH THEN HOLDS ON INTO MID WEEK. HIGHS
IN THE 30S OR 40S MONDAY LOOK TO STAY IN THE 40S INTO WEDNESDAY.
PRECIPITATION CHANCES SHOULD REMAIN RELATIVELY LOW GIVEN NORTHWEST
MID LEVEL FLOW.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
151 AM EDT THU MAR 28 2013
.SYNOPSIS...
A COLD NORTHWEST FLOW WILL PERSIST THROUGH THE REMAINDER OF THE WORK
WEEK...OCCASIONALLY BRINGING SCATTERED SNOW AND RAIN SHOWERS.
TEMPERATURES WILL FINALLY BUT BRIEFLY TURN SLIGHTLY MILDER OVER
THE WEEKEND...AND THEN WE WILL RETURN TO A COOL UNSETTLED PATTERN.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
715 PM UPDATE...
DIURNAL CONVECTION CONTS AT THIS TIME AIDED BY TROF ALOFT. HV
TWEAKED POPS TO KEEP SCTD SNOW SHOWERS IN ACRS MAJORITY OF CWA
TONIGHT UNTIL TROF PASSES OFF TO THE SOUTH. ALSO DID SLIGHT
ADJUSTMENT TO KEEP UP WITH HRLY TEMP TRENDS BUT NO CHGS NEEDED TO
MINS. HV WORDED SNOW/RAIN SHOWERS IN THRU 01Z FOR VLY LOCATIONS
THEN BCMG ALL SNOW AFT THAT TIME.
4 PM UPDATE...
QUICK UPDATE TO EXPAND 50 POPS ACRS MOST OF THE CWA WITH EXCEPTION
OF NERN CNTYS AS THEY RMN UNDER SUBSIDENCE AFT FIRST S/WV PASSED
BY. EXPECT SNOW SHOWERS TO WEAKEN BY 00Z TNGT BFR RE-DVLPNG AFT
MIDNIGHT AS MAIN UL TROF DROPS THRU AND REGENERATES POPS.
130 PM UPDATE...
WEAK WAVE IS DROPPING OVER THE REGION WHICH WITH DIURNAL HEATING
IS CAUSING EXPECTED BLOSSOM OF SCATTERED RAIN/SNOW SHOWERS AND
SPRINKLES/FLURRIES. AS PER LOCAL HIGH RESOLUTION MODELS...WE
ARE HAVING A RELATIVE MAXIMUM IN DIURNAL ACTIVITY ACROSS THE
CENTRAL TO SOUTHWESTERN ZONES COMPARED TO THE NORTHEAST. SUBSIDENCE
AND DRIER COLUMN THIS AFTERNOON/EARLY EVENING BEHIND WAVE IN THE
NORTHEASTERN ZONES INCLUDING MOHAWK VALLEY AND NY THRUWAY...SHOULD
LEAD TO RELATIVE MINIMUM IN ACTIVITY THERE...BEFORE BETTER WAVE
DROPS IN LATER TONIGHT. FORECAST DETAILS HAVE BEEN ADJUSTED
ACCORDINGLY.
RUC/RAP SOUNDINGS HAVE STEEPER LAPSE RATES AND THUS MORE
INSTABILITY COMPARED TO THE NAM. GIVEN THAT MAV AND ESPECIALLY
MET GUIDANCE HAVE BEEN TOO COLD LATELY...AND THE EXTRA ENERGY FROM
EARLY SUNSHINE TODAY...THE MORE UNSTABLE RUC SOUNDINGS ARE A
BETTER REPRESENTATION. CONVECTIVE NATURE TO THE SCATTERED SHOWERS
ARE THUS BEING REALIZED AS CAN BE SEEN ON THE RADAR THE LAST HOUR
OR SO...COMPLETE WITH BURSTS OF GRAUPEL. ALSO...MET GUIDANCE AGAIN
HAS BEEN SHOWN TO BE MUCH TOO COOL FOR TEMPERATURES THIS AFTERNOON.
AFTER DIURNAL ACTIVITY WANES LATE AFTERNOON INTO EVENING...A
BETTER UPPER TROUGH WILL DROP NORTH TO SOUTH 03Z-09Z
OVERNIGHT...ALLOWING SCATTERED SNOW SHOWERS TO
REDEVELOP...ESPECIALLY CENTRAL NY. THAT BEING SAID...ACCUMULATIONS
WILL BE GENERALLY ONLY A FEW TO SEVERAL TENTHS OF AN INCH FOR
MOST LOCATIONS. WITH AMOUNT OF CLOUDS OVERNIGHT...NOT FIGURING ON
MUCH RADIATIONAL COOLING AND SO NEAR OR SLIGHTLY ABOVE BLENDED
GUIDANCE IS EXPECTED FOR LOW TEMPERATURES /MID 20S TO AROUND 30/.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
230 PM UPDATE...
MAIN UPPER TROUGH AXIS WILL FINISH EXITING SOUTH THURSDAY
MORNING. MODELS SUGGEST THAT A WEAKER SHORTWAVE WILL STILL SLIP
THROUGH DURING THE DAY. HOWEVER...THICKNESSES WILL BE A GOOD 5 OR SO
DECAMETERS HIGHER...AND SO LAPSE RATES WILL NOT BE AS STEEP. AS
DIURNAL ENERGY AGAIN TRIES TO BURP UP SCATTERED SHOWERS...THERE WILL
NOT BE AS MUCH INSTABILITY COMPARED TO 24 HOURS PRIOR...AND RIDGING
WILL ALREADY BE INITIATING ALOFT. I ONLY PLACED SLIGHT TO LOW CHANCE
POPS...AND MAINLY UP TO MIDDAY...FOR DIURNAL ENHANCEMENT AND PASSING
WAVE. AS WITH RECENT DAYS...I HAVE STAYED ON WARM SIDE OF MODEL
GUIDANCE FOR HIGH TEMPERATURES THURSDAY...ESPECIALLY THE MAV WHICH
HAS BEEN MUCH TOO COOL LATELY. MAINLY 40S AREAWIDE. WETBULBING AGAIN
WILL ALLOW SNOW OR GRAUPEL WITHIN THE SHOWERS DESPITE TEMPERATURES
GETTING WELL ABOVE FREEZING.
WEAK RIDGING THURSDAY EVENING...WILL GIVE WAY TO ANOTHER WEAK TROUGH
THAT WILL DIP INTO THE AREA FRIDAY...THOUGH FOR THE FIRST TIME IN
QUITE AWHILE...NOT ONE ASSOCIATED WITH THE RESIDENT UPPER LOW IN
THE CANADIAN MARITIMES. MOISTURE WILL BE FAIRLY SHALLOW...YET LAPSE
RATES ALSO STEEPER. THUS WITH THE PASSING FEATURE...DIURNAL
INSTABILITY WILL PROBABLY HELP TO REALIZE ADDITIONAL SCATTERED
RAIN/SNOW SHOWERS.
BY SATURDAY...CYCLONIC FLOW WILL GIVE WAY TO A BETTER RIDGE ON ITS
WAY IN. MOISTURE GETS VERY SHALLOW AS WARM AIR ADVECTION ENSUES
ALOFT. FIGURING ON A DRY NEAR CLIMATOLOGY DAY WITH STRATOCUMULUS
BECOME MORE CELLULAR AND THEN SCATTERING OUT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE. A BRIEF BREAK IN THE COLD SAT NGT TO
SUNDAY WITH SFC HIGH PRESSURE AND AN UL RIDGE. A COLD FRONT GOES
THROUGH SUN AFTN AND EVE WITH MOSTLY RAIN...WHICH MAY CHANGE TO
SNOW BEFORE ENDING. ANOTHER BREAK LATE SUN NGT TO MON BEFORE
COLDER AIR COMES IN MON NGT WITH SNOW...A COLD FRONT AND STRONG
SHORT WAVE. THE LOW LEVEL FLOW SHIFTS TO NW BEHIND THE FRONT SO
SNOW SHOWERS FOR TUES AND WED. COOLER THAN NORMAL WITH A DEEP
UPPER LEVEL TROF IN THE NE US.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
UPR TROF MVG THRU THE AREA THIS MRNG IS PRODUCING SOME LGT RN AND
SN SHWRS ALONG WITH MVFR AND IFR CIGS. XPCT LTL CHG OVRNGT WITH
THE LL MOISTURE AND LGT WINDS THERE/S LTL TO IMPRV CONDS. AFT
SUNRISE...MIXING WILL SLOWLY IMPROV STATIONS TO VFR/MVFR BUT WITH
THE CONTSD THREAT OF SHWRS. XPCT CONDS TO LWR ONCE AGAIN AFT 00Z
AS STABLE SNDG RETURNS AND LL MOISTURE REMAINS.
.OUTLOOK...
FRI/FRI NGT...OCNL RESTRICTIONS IN -SHSN/FLRYS THROUGHOUT THIS
PD...MAINLY FOR THE CNY TERMINALS.
SAT TO SUN AM...MAINLY VFR.
SUN AFTN TO EVE...MVFR POSSIBLE IN RAIN SHOWERS.
LATE SUN NGT TO MON...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP/PVN
SHORT TERM...MDP
LONG TERM...TAC
AVIATION...DGM/DJP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
356 AM CDT THU MAR 28 2013
.SHORT TERM...TODAY AND TONIGHT...
ISSUED AT 355 AM CDT THU MAR 28 2013
THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM IS FOG.
LATEST 11-3.9 SATELLITE IMAGERY AND SURFACE OBSERVATIONS AT 08Z
DEPICT AN AREA OF DENSE FOG AND A LOW STRATUS DECK ACROSS NORTHERN
NORTH DAKOTA...EXPANDING SOUTH TOWARDS THE JAMES RIVER VALLEY.
DEWPOINT DEPRESSIONS ACROSS THE SNOW PACK CONTINUE TO HOVER AROUND 0
DEGREES...INDICATING A VERY MOIST BOUNDARY LAYER. THIS WAS ALSO
COINCIDENT WITH CALM TO LIGHT AND VARIABLE WINDS...GENERATING AN
ENVIRONMENT CONDUCIVE TO MAINTAINING DENSE FOG AND THE DEVELOPMENT
OF FOG FURTHER SOUTH ACROSS THE JAMES RIVER VALLEY. ACROSS THE
SNOWLESS SOUTHWEST...THE LACK OF MOISTURE AND PRESENCE OF HIGH THIN
CIRRUS...HAVE LIMITED THE DEVELOPMENT OF FOG. HAVE DECIDED TO REMOVE
PATCHY FOG WORDING IN THE WEATHER GRIDS...WHILE KEEPING AREAS TO
WIDESPREAD FOG/DENSE FOG WORDING ELSEWHERE. THIS IS SUPPORTED BY THE
4Z HRRR...WHERE IT CONTINUES TO DEPICT WIDESPREAD VISIBILITIES BELOW
ONE HALF MILE WITH LOW STRATUS WHERE A SNOW PACK IS PRESENT THROUGH
THE MORNING. AFTER SUNRISE...THE HRRR HAS THE AREAL COVERAGE OF
LOWERED VISIBILITIES SLOWLY ERODING LATE THIS MORNING...WHILE IT AND
OTHER 00Z MODEL GUIDANCE KEEPS LOW LEVEL STRATUS THROUGH AT LEAST
17Z. THEREAFTER...THE STRATUS DECK AND ANY REMAINING FOG WILL GIVE
WAY TO MOSTLY SUNNY CONDITIONS AND WARMING TEMPERATURES INTO THE MID
20S NORTH TO LOWER 50S SOUTHWEST DURING THE AFTERNOON. AT THIS
TIME...WILL KEEP DENSE FOG ADVISORY GOING AS IS SINCE IT IS
REPRESENTATIVE OF CURRENT CONDITIONS.
.LONG TERM...FRIDAY THROUGH THURSDAY...
ISSUED AT 355 AM CDT THU MAR 28 2013
NORTHWEST FLOW ALOFT IS FORECAST TO REMAIN IN PLACE THROUGH MUCH
IF NOT ALL OF THE LONG TERM FORECAST PERIOD. WILL SEE AN ACTIVE
FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND. THE
EC/GFS/GEM/NAM ALL CONTINUE TO DEPICT AN EMBEDDED MID LEVEL S/WV
IMPULSE SLIDING SOUTHEAST ACROSS NORTH DAKOTA ALONG WITH AN AREA
OF ASSOCIATED SURFACE LOW PRESSURE FRIDAY/FRIDAY NIGHT. WILL
MAINTAIN CHANCES FOR MIXED PRECIPITATION WITH THE COMBINATION OF
WAA ALOFT COMBINED WITH BELOW/ABOVE FREEZING SURFACE AIR
TEMPERATURES. BOTH THE NAM AND GFS STILL GENERATE DAYTIME
INSTABILITY FRIDAY MID/LATE AFTERNOON OVER SOUTHWEST NORTH
DAKOTA...WITH THE LATEST SPC DAY 2 OUTLOOK NOW JUST OFF TO OUR
SOUTH AND WEST. WILL KEEP AN EYE ON THIS PERIOD OVER THE NEXT FEW
FORECAST CYCLES IN CASE WE NEED TO ADD THUNDER INTO THE FORECAST.
CLOSED UPPER LOW MOVING SOUTH ACROSS CENTRAL CANADA SATURDAY AND
INTO THE GREAT LAKES REGION SUNDAY AND MONDAY WILL BRING A SURGE
OF COLDER AIR INTO THE NORTHERN PLAINS FOR THE EASTER HOLIDAY
WEEKEND. BUMPED HIGH/LOW TEMPERATURES DOWN SEVERAL DEGREES SUNDAY
AND MONDAY. ENOUGH ENERGY ALOFT SHOULD ALSO SEE SOME SLIGHT
CHANCES FOR PRECIPITATION THIS WEEKEND.
WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT
WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS
DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. FOR NOW
STUCK WITH ALLBLEND POPS GIVING ME SLIGHT CHANCES FOR MIXED PRECIP
WED/WED NIGHT. TEMPERATURES MODERATE BACK TO NORMAL MID-WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 355 AM CDT THU MAR 28 2013
HIGH PRESSURE OVER EASTERN NORTH DAKOTA WILL MOVE SLOWLY EAST
THROUGH THE FORECAST PERIOD. THIS WILL CONTINUE BRING A MOIST EAST
TO SOUTHEAST FLOW ACROSS ALL TAF SITES THROUGH THE PERIOD. SATELLITE
IMAGERY AT 08 UTC...SHOWS AN AREA OF DENSE FOG AND STRATUS EXPANDING
SOUTH FROM NORTHERN NORTH DAKOTA INTO THE JAMES RIVER VALLEY. LIFR
CONDITIONS HAVE BEEN REPORTED AT KISN/KMOT...WHILE VFR CONDITIONS
CONTINUE AT KDIK/KBIS/KJMS. HOWEVER...LIFR CONDITIONS IN DENSE
FOG/STRATUS ARE EXPECTED TO DEVELOP AT KJMS OVER THE NEXT FEW HOURS.
MVFR/IFR CONDITIONS MAY DEVELOP AT KBIS BUT UNCERTAINTY IS HIGH.
KDIK WILL CONTINUE TO SEE VFR CONDITIONS THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR NDZ001>005-009>013-
021>023-025.
&&
$$
SHORT TERM...LTH
LONG TERM/AVIATION...NH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
353 AM CDT THU MAR 28 2013
.SHORT TERM...
QUITE INTERESTING TEMP PATTERN EARLY THIS MORNING. GFS SHOWS 925
MB WINDS NR 15 KTS IN NE SD/SE ND/WCNTRL MN AND IN THIS AREA SFC
WINDS REMAINING SOUTHEAST 5 TO 10 KTS AND TEMPS ARE QUITE A BIT
HIGHER FARGO-DETROIT LAKES-FERGUS FALLS REGION AND STILL IN THE
MID 20S. NORTH OF THIS AREA DVL-GFK NORTHWARD WINDS ARE LIGHTER
AND TEMPS FALLING INTO THE UPPER SINGLE DIGITS AND SOME FOG
FORMING. HAVE NOTICED PAST HOUR CLOUDS INCREASING IN MID LEVEL
WARM ADV ZONE OVER SE ND AND PUSHING NORTHWARD AND THIS SHOWN
SOMEWHAT ON LATEST RAP MODEL IN SPREADING CLOUD COVER NORTHWARD
THRU THE RED RIVER VALLEY EARLY THIS MORNING. IT ALSO KEEPS TEMPS
MUCH MILDER IN THE SRN VALLEY AND PARTS OF WCNTRL MN THRU 12Z.
SO DOES LOOK LIKE A WARMER TEMP SURGE AND SOME CLOUDS WILL SPREAD
NORTHWARD INTO THE NRN VALLEY THROUGH MID MORNING AND TRIED TO
ADJUST TEMP CURVE FOR THIS.
OVERALL TODAY THOUGH WILL LIKELY SEE SOME CLOUD COVER VALLEY INTO
NW MN IN WARM ADV ZONE AND RAP/GFS SHOWS SOME DECENT 850 MB
MOISTURE IN PLACE. TEMPS SHOULD WARM TODAY AS WELL TO ABOVE
FREEZING IN ALL BUT DVL BASIN. PROVIDED SUN APPEARS AT SOME POINT
IN THE FAR EAST TODAY ANOTHER 40-45 DEGREE DAY IS LIKELY.
ATTENTION TURNS TO LATER FRIDAY AND FRIDAY NIGHT. NOT WELL
ORGANIZED VORT MAX REGION FROM WASHINGTON STATE INTO MONTANA WILL
SPREAD EAST INTO ND/NW MN BY 12Z SAT. SFC LOW WILL BE TO OUR SOUTH
AND THERE WILL A SPREAD OF MOISTURE NORTH AND THEN NORTHEAST INTO
ERN ND AND ESPECIALLY INTO MINNESOTA AND ERN SD AS THIS SYSTEM
PASSES THROUGH. TEMP PROFILES USING BUFKIT SHOW ENOUGH WARMING AT
850 AND BELOW FOR MOSTLY LIQUID PRECIPITATION FOR THIS EVENT. NOW
SFC TEMPS SUGGEST PLAIN LIGHT RAIN FOR FAR SRN ND INTO WCNTRL MN
AND NORTH CENTRAL MN THRU FRI EVE...WITH TEMPS CLOSE ENOUGH TO 32F
IN DVL BASIN AND THE NRN VALLEY FOR RA/FZRA. TEMPS WILL FALL
ENOUGH FOR SOME PSBL FZRA IN FAR SE ND INTO WCNTRL/NORTH CENTRAL
MN OVERNIGHT FRI NIGHT BEFORE PRECIP MOVES OUT SATURDAY MID
MORNING. DID KEEP A LITTLE -SN MIX IN NE ND LATE FRI NIGHT AS
COOLER 850 MB AIR MOVES IN. WPC WWD GRAPHICS DOWNPLAY THREAT FOR
FZRA IN OUR AREA... SREF PROB FOR FZRA ARE HIGHEST IN THE CNTRL
RED RIVER VALLEY FRI NIGHT. REGARDLESS OF PTYPE AMOUNDS LOOK LIGHT
THOUGH A TENTH OF AN INCH OF LIQUID PSBL IN WARMER TEMP REGIME IN
WCNTRL MN.
.LONG TERM...SUNDAY THROUGH WEDNESDAY.
LONG WAVE TROUGH OVER WESTERN ATLANTIC WEAKENS AND RETROGRESSES OVER
EASTERN CANADA BY THE END OF THE PERIOD. CONCURRENTLY LONG WAVE
RIDGE OVER THE WEST CANADIAN COAST WEAKENS. GFS WAS THE FASTER
SOLUTION THAN THE ECMWF AT THE BEGINNING OF THE PERIOD AND BECOMES
MORE SO BY THE END OF THE PERIOD. WILL PREFER THE SLOWER ECMWF.
ISOLATED LOW POPS IN THE NORTHEAST ZONES FOR SUN NIGHT WAS REMOVED.
WITH GFS BEING FAST WILL REMOVE POPS ON WED AND WED NIGHT.
LOWERED HIGH TEMPS SUN BY THREE DEGREES BELOW GUIDANCE. OTHERWISE
HIGH TEMPS ARE A DEGREE OR TWO HIGHER THAN YESTERDAYS RUN FOR MON
THROUGH WED.
.AVIATION...
LATEST OBSERVATIONS INDICATE THE SPREAD OF 4-6K FT CLOUDS
NORTHWARD THRU THE THE VALLEY AND PARTS OF NW MN EARLY THIS
MORNING AND THIS SHOULD CONTINUE THIS MORNING BEFORE CLEARING OUT.
THIS IMPACT WILL GET RID OF THE FOG PATCHES IN MOST
AREAS....LEAVING GENERALLY VFR CONDITIONS AT TAF SITES BEYOND 12Z.
WINDS WILL BE SOUTH-SOUTHEAST 5 TO 10 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
RIDDLE/HOPPES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
108 AM CDT THU MAR 28 2013
.UPDATE...
ISSUED AT 107 AM CDT THU MAR 28 2013
LATEST 11-3.9 SATELLITE IMAGERY AT 05Z...SHOWS AN EXPANDING AREA
OF DENSE FOG...WITH VISIBILITIES DOWN BELOW ONE QUARTER OF A
MILE...FROM THE NORTHWEST EAST THROUGH THE SOURIS RIVER AND SOUTH
THROUGH DENHOFF AND CARRINGTON. HAVE ISSUED A DENSE FOG ADVISORY
FOR THESE AREAS...THROUGH MID MORNING. THE 02Z HRRR AND LAMP
GUIDANCE CONTINUES TO SUGGEST WIDESPREAD REDUCED VISIBILITIES
BELOW ONE HALF MILE NORTH AND EAST OF THE MISSOURI RIVER. DEWPOINT
DEPRESSIONS ACROSS MUCH OF THE SNOW PACK ARE HOVERING AT 0 TO 1
DEGREES WITH LIGHT WINDS...SO AM EXPECTING THE DENSE FOG TO
INCREASE IN AREAL COVERAGE AS THE MORNING CONTINUES TO INCLUDE
LOCATIONS IN THE JAMES RIVER VALLEY WEST THROUGH THE MISSOURI
RIVER VALLEY. HOWEVER...CLOUD COVERAGE HAS INCREASED ACROSS THE
CENTRAL AND EAST AND COULD BE A LIMITING FACTOR TO THE EXPANSION
OF DENSE FOG. WILL CONTINUE TO MONITOR...TO DETERMINE IF THE
ADVISORY NEEDS TO BE EXPANDED.
OTHERWISE...MADE MINOR CHANGES TO ONGOING FORECAST FOR LATEST
OBSERVATIONS.
UPDATE ISSUED AT 930 PM CDT WED MAR 27 2013
BRIGHT SHINNING STARS WILL SLOWLY DIM AS FOG OBSCURES THEIR VIEW
LATER THIS EVENING. FOR THIS UPDATE...FOG WAS EXPANDED WEST...COVERAGE WAS
INCREASED AND DENSE FOG WAS INCLUDED FOR PORTIONS OF THE JAMES AND
MISSOURI RIVER VALLEYS. TEMPERATURES CONTINUE TO COOL QUICKLY
UNDER CLEAR SKIES. DEWPOINT DEPRESSIONS OVER AREAS WITH SNOW PACK
CONTINUE TO HOVER NEAR ZERO. WITH A VERY MOIST BOUNDARY LAYER OVER
THE SNOWPACK...LIGHT WINDS...AND CLEAR SKIES...FOG IS BEGINNING TO
DEVELOP THIS EVENING. FOG IS DEVELOPING FIRST IN THE FAR NORTHWEST
AND EASTERN JAMES RIVER VALLEY. LATER FOG WILL DEVELOP WEST ALONG
THE MISSOURI RIVER VALLEY. AREAS WITH DEEP SNOW PACK ARE MOST
LIKELY TO EXPERIENCE WIDESPREAD FOG. THE 22 UTC RUN OF THE HRRR
AND LATEST LAMP GUIDANCE SUGGEST SOME LOCATIONS ALONG THE JAMES
RIVER VALLEY AND UPPER MISSOURI VALLEY COULD SEE DENSE FOG AFTER
MIDNIGHT. NO OTHER CHANGES WERE MADE TO THE FORECAST IN THIS
UPDATE.
UPDATE ISSUED AT 634 PM CDT WED MAR 27 2013
AS THE SUN SETS TEMPERATURES SHOULD BEGIN TO COOL QUICKLY WITH
CLEAR SKIES AND DIMINISHING WINDS. DEWPOINT DEPRESSIONS OVER
AREAS WITH SNOW PACK ARE VERY LOW RANGING FROM 4 DEGREES DOWN TO
ZERO. WITH A VERY MOIST BOUNDARY LAYER OVER THE SNOWPACK...LIGHT
WINDS...AND CLEAR SKIES...FOG IS LIKELY TO DEVELOP TONIGHT. THE
JAMES RIVER VALLEY IS MOST LIKELY TO SEE WIDESPREAD FOG WITH
DEWPOINT DEPRESSIONS ALREADY AT ZERO AND A LIGHT UPSLOPE WIND.
PATCHY FOG IS ALSO POSSIBLE IN THE MISSOURI RIVER VALLEY...ESPECIALLY
IN AREAS WITH SNOW PACK. SOME LOCATIONS ALONG THE JAMES RIVER
VALLEY COULD SEE DENSE FOG AFTER MIDNIGHT. HOWEVER NO CHANGES WERE
MADE TO THE FOG FORECAST FOR THIS UPDATE. WILL MONITOR CURRENT
TRENDS AND REANALYZE THE FOG THREAT FOR TONIGHT TO SEE IF
ADDITIONAL AREAS OF FOG NEED TO BE ADDED AND OR CURRENT FOG
UPGRADED TO DENSE FOG. NO MAJOR CHANGES WERE MADE TO THE REST OF
THE FORECAST. UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...TONIGHT THROUGH THURSDAY AFTERNOON...
LATEST WATER VAPOR IMAGERY SHOWS A BROAD SHORTWAVE RIDGE ACROSS
NORTH DAKOTA WITH A SHORTWAVE TROUGH SEEN OVER EAST CENTRAL
SASKATCHEWAN SLIDING SOUTHEAST WITH TIME. UPWARD VERTICAL MOTION
FIELD PER NAM/GFS/RAP H85-H3 OMEGA REMAINS WEAK AS IT QUICKLY
SLIDES THROUGH EAST CENTRAL TONIGHT. SOUNDINGS SHOW AN OVERALL DRY
COLUMN WHICH IS NOT SUPPORTIVE FOR PRECIPITATION...THUS WILL
MAINTAIN A DRY FORECAST. LIGHT WINDS...AND CLEAR SKIES INITIALLY
WILL LIKELY PROMPT THE DEVELOPMENT OF LOW CLOUDS/FOG IN THE JAMES
RIVER VALLEY BY MID EVENING. HAVE INCREASED CLOUDS TO MOSTLY
CLOUDY IN THE SKY GRIDS AND MENTIONED AREAS OF FOG JAMES RIVER
VALLEY...AND PATCHY FURTHER NORTH AND WEST. CURRENT UPSTREAM
OBSERVATIONS AHEAD OF THE SHORTWAVE DO SHOW SCT/BKN LOW TO MID
CLOUDS BUT NOT SEEING ANY SIGNS OF OBSERVED PRECIPITATION. LOW
TEMPERATURES TONIGHT WILL RANGE FROM AROUND 10 ABOVE NORTH TO NEAR
20 SOUTHWEST. HIGHS THURSDAY WILL RANGE FROM THE UPPER 20S NORTH TO
UPPER 40S SOUTHWEST.
.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY...
THURSDAY NIGHT THROUGH FRIDAY NIGHT...ZONAL WEST-TO-EAST FLOW IN THE
WESTERLIES WILL DOMINATE THE NORTHERN PLAINS. THE MODELS BRING AN
EMBEDDED SHORTWAVE IN THIS FLOW ACROSS THE STATE FRIDAY AND FRIDAY
NIGHT...AND INCREASED CHANCES AND AREAL COVERAGE OF PRECIPITATION.
TEMPERATURE PROFILES INDICATE PRECIPITATION WOULD BE A MIX OF TYPES
- FROM FREEZING RAIN FRIDAY MORNING IN THE WEST...TO RAIN SOUTHWEST
AND RAIN OR SNOW NORTHWEST AND CENTRAL FRIDAY AFTERNOON...TO
RAIN/SLEET/SNOW FRIDAY NIGHT. PRECIPITATION AMOUNTS SHOULD BE
LIGHT...BUT WILL KEEP THE HIGHLIGHT IN THE HAZARDOUS WEATHER
OUTLOOK.
SATURDAY THROUGH NEXT TUESDAY...THE UPPER LEVEL PATTERN SHIFTS TO A
MORE NORTHWEST/NORTHERLY FLOW AND ALLOWS A SURFACE ARCTIC AIRMASS OF
HIGH PRESSURE PLUNGES SOUTHWARD FROM CENTRAL CANADA. THE MODEL
CONSENSUS IS THE COLD FRONT MOVES SOUTHWARD THROUGH THE STATE ON
SATURDAY...BRINGING WELL BELOW AVERAGE TEMPERATURES FOR THE WEEKEND
INTO EARLY NEXT WEEK.
REGARDING TEMPERATURES: LOOKING AT HIGHS SATURDAY FROM THE 30S NORTH
TO 40S SOUTHWEST AS THE FRONT MOVES THROUGH...THEN HIGHS IN THE 20S
NORTH AND 30S SOUTHWEST SUNDAY AND MONDAY. NIGHTTIME TEMPERATURES
WILL LIKELY RANGE FROM 5 TO 15 ABOVE SUNDAY NIGHT AND MONDAY NIGHT.
TEMPERATURES BEGIN TO RECOVER A BIT ON TUESDAY AS THE ARCTIC HIGH
EXITS TO THE EAST...WITH HIGHS FROM THE 20S IN THE TURTLE MOUNTAINS
TO AROUND 40 SOUTHWEST.
BY NEXT WEDNESDAY...HIGHS AGAIN IN THE 30S NORTH AND CENTRAL TO THE
40S SOUTHWEST. ANOTHER UPPER LEVEL SYSTEM IS PROGGED TO MOVE
SOUTHEAST ACROSS THE STATE...WITH CHANCES OF A MIX OF PRECIPITATION
TUESDAY NIGHT AND WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 107 AM CDT THU MAR 28 2013
MVFR CLOUDS WERE DEVELOPING OVER THE KBIS TAF AREA...AND WILL
ACCOUNT FOR THIS DEVELOPMENT WITH SCT-BKN MENTION AT 1500 FEET
THROUGH 20Z. IFR CIGS/VSBYS DISSIPATING AT KJMS. OTHERWISE EXPECT
VFR CONDITIONS FOR THE AFTERNOON AND EVENING HOURS. HOWEVER...EXPECT
MVFR TO IFR CIGS/VSBYS AFT 06Z FOR CENTRAL NORTH DAKOTA SITES OF
KMOT/KBIS/KJMS. SOUTHEAST WIND FLOW THROUGHOUT THE FORECAST PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR NDZ001>005-009>013-
021>023-025.
&&
$$
UPDATE...LTH
SHORT TERM...KS
LONG TERM....JV
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
337 AM CDT THU MAR 28 2013
.SHORT TERM...TODAY THROUGH SATURDAY
WAA BAND OF MID LEVEL CLOUDS WERE FORMING THIS MORNING ACROSS THE
FAR EASTERN CWA. THIS SHOULD CONTINUE TO MOVE EAST. THERE WERE
ALSO MORE MID LEVEL CLOUDS MOVING INTO THE WESTERN CWA EARLY THIS
MORNING. OTHERWISE...THE ISSUE THIS MORNING WILL BE THE FOG
FORMATION. NOT MUCH FOR FOG SHOWING UP ON SURFACE OBS OR SATELLITE
EARLY THIS MORNING. ALTHOUGH...SOME WEB CAMS SHOWED SOME FOG OUT
WEST. MUCH OF THE FOG WAS ACROSS THE BORDER IN ND EXPANDING
SOUTHWARD. WITH THE WINDS BECOMING LIGHT AT ABR ALONG WITH A
DECREASING DEW POINT SPREAD...BELIEVE THIS FOG/STRATUS AREA WILL
CONTINUE TO EXPAND SOUTHWARD INTO NORTHERN SD THIS MORNING. THERE
COULD ALSO BE SOME PATCHY DENSE FOG. THE HRRR MODEL ALSO SHOWED
INDICATIONS OF STRATUS AND LOWER VISIBILITIES DEVELOPING INTO
NORTHERN SD THIS MORNING. THUS...CONTINUED WITH FOG THROUGH 10 AM
WITH SOME PATCHY DENSE FOG. THE VISIBLE SATELLITE SHOWED VERY WELL
WHERE THE SNOW COVERED AREAS REMAIN. SURFACE OBS ALSO SHOW THE
SNOW TO BE DEEP ACROSS MUCH OF THE EASTERN CWA WITH UP TO 12
INCHES STILL IN SOME LOCATIONS. THIS SNOW COVER WILL CONTINUE TO
HAVE AN AFFECT ON TEMPERATURES WITH VERY LITTLE MIXING DESPITE THE
LATE MARCH SUN. FOR TODAY THROUGH FRIDAY...ALL OF THE MODELS SHOW
THE LOW LEVEL 925MB AND 850MB TEMPERATURES RISING. THUS...LOOK FOR
HIGH TEMPERATURES TO BE WARMER EACH DAY FROM THURSDAY TO FRIDAY.
THE BARE GROUND AREAS FOR THE COUNTIES EITHER SIDE OF THE MISSOURI
RIVER WILL WARM UP QUITE A BIT TODAY AND FRIDAY. SHOULD HAVE 50S
AND LOWER 60S FOR THIS AREA FOR BOTH DAYS. INCREASED HIGHS ALSO IN
THE EAST AS THE SNOW COVER DIMINISHES OVER THE NEXT FEW DAYS BUT
WILL STILL HAVE A BIG INFLUENCE ON TEMPERATURES. STILL HAVE HIGHS
IN THE MID 30S TO THE MID 40S OVER THE SNOW COVER FOR THURSDAY
AND FRIDAY. WITH MORE SNOW MELT MOISTURE ALONG WITH LIGHT WINDS
AND A GOOD INVERSION...COULD HAVE SOME MORE FOG EAST IN THE CWA
LATE TONIGHT AND FRIDAY MORNING.
THE MODELS CONTINUE TO SHOW A SHORT WAVE TROUGH ALONG WITH A
SURFACE COOL FRONT DROPPING ACROSS THE REGION FRIDAY NIGHT AND
EARLY SATURDAY. THE MODELS ALL SHOW DIFFERENT SOLUTIONS FOR QPF
WITH THIS SYSTEM. INCREASED POPS TO GOOD CHANCES MAINLY EAST IN
THE CWA FOR FRIDAY NIGHT. WITH ALL OF THE WARM AIR ALONG WITH NOT
MUCH COOLING AT THE SURFACE FRIDAY NIGHT...ALL MODEL INDICATIONS
POINT TO JUST RAIN WITH THIS SYSTEM PASSAGE. SATURDAY WILL HAVE
BETTER MIXING WITH MAINLY COOLER TEMPERATURES OUT WEST WITH STILL
UPPER 30S TO THE MID 40S OVER THE DIMINISHED SNOW COVERED AREAS EAST.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
THE LONG TERM PATTERN WILL FEATURE AN UPPER LOW DROPPING SOUTH
ACROSS CANADA...FIRST MOVING ACROSS NORTHERN MANITOBA AND THEN
EASTWARD TO THE GREAT LAKES REGION. THIS WILL PLACE OUR AREA OF
CONCERN IN NORTHWEST FLOW ALOFT...AND MOST OF THE ENERGY
ASSOCIATED WITH THE UPPER LOW WILL STAY NORTH OF OUR AREA.
HOWEVER...RIGHT NOW...THE BEST CHANCES FOR ANY TYPE OF
PRECIPITATION ACROSS OUR CWA WILL BE ON SUNDAY. MODELS ARE SHOWING
SOME CONSENSUS WITH TRACKING A COLD FRONT ACROSS THE REGION...AND
700 MB OMEGA VALUES INDICATE WEAK TO MODERATE FORCING...SO
INCLUDED A CHANCE OF LIGHT SNOW ACROSS THE SOUTHERN HALF OF THE
CWA. TEMPERATURES REALLY PLUMMET BEHIND THIS FEATURE AS WELL. 925
MB TEMPERATURES DROP INTO THE SINGLE DIGITS AND TEENS BELOW ZERO
SUNDAY AND MONDAY. ALLBLEND HAS BEEN SLOW TO RESPOND TO THE
COOLING TREND...SO USED A DETERMINISTIC MODEL BLEND AND DROPPED
TEMPERATURES ACCORDINGLY. THE COLD AIR DOESNT STICK AROUND TOO
LONG HOWEVER...AND RETURN FLOW WINDS ON TUESDAY SHOULD BE ABLE TO
TRANSPORT WARMER AIR BACK INTO THE REGION BY EARLY TO MID WEEK.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED TO PERSIST POSSIBLY FOR AS MUCH AS A
FEW MORE HOURS BEFORE RADIATION FOG BEGINS TO DEVELOP AND FLIGHT
CATEGORY DROPS BELOW VFR. REGIONAL SATELLITE AND SURFACE
OBSERVATIONS ARE BEGINNING TO SHOW AREAS OF FOG/LOW STRATUS
FORMING THROUGHOUT THE REGION. SNOW-MELT EARLIER ON WEDNESDAY
ADDS SOME ADDITIONAL MOISTURE TO THE BOUNDARY LAYER TONIGHT.
ANOTHER NIGHT OF LIGHT WINDS AND CLEAR SKIES WITH ADDITIONAL
SURFACE/BOUNDARY LAYER MOISTURE SHOULD AID ADDITIONAL COVERAGE OF
FOG AND LOW STRATUS FORMATION BEFORE SUNRISE AND RIGHT ON INTO
THURSDAY MORNING. BUFKIT AND UPS FOG CROSSOVER-DEWPOINT TECHNIQUE
INDICATES A PRETTY GOOD CHANCE OF FOG AND/OR LOW STRATUS
DEVELOPING OVER THE CWA LATE TONIGHT INTO THURSDAY MORNING. GIVEN
THAT FOG/STRATUS HAVE DEVELOPED IN SPOTS OVER THE CWA EACH OF THE
PAST COUPLE OF NIGHTS...FORECASTER CONFIDENCE IS FAIRLY HIGH THAT
FOG/STRATUS WILL DEVELOP OVERNIGHT WITH ONE OR MORE TERMINALS
FALLING INTO SOME CATEGORY OF IFR CONDITION BY 12Z THURSDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...MOHR
LONG TERM...SERR
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1100 PM MDT WED MAR 27 2013
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 221 PM MDT WED MAR 27 2013
20Z UPPER LEVEL ANALYSIS SHOWS A RIDGE OVER THE WESTERN CONUS MOVING
INTO THE NORTHERN PLAINS. SKIES ACROSS THE AREA ARE MOSTLY SUNNY.
WINDS ARE LIGHT AND VARIABLE...AND TEMPS ARE CLIMBING INTO THE 40S
AND LOWER 50S.
LIGHT WINDS AND PARTLY CLOUDY SKIES ARE EXPECTED TONIGHT...WITH LOWS
IN THE 20S. THE NAM IS SHOWING THE POSSIBILITY FOR SOME PATCHY
SHALLOW FOG ACROSS PARTS OF WESTERN SOUTH DAKOTA BY EARLY THURSDAY
MORNING...BUT THE RAP AND GFS ARE DRIER. NOT CONVINCED ANYTHING WILL
DEVELOP...SO WILL LEAVE IT OUT OF THE FORECAST FOR NOW.
AS THE RIDGE PROGRESSES EASTWARD...TEMPS WILL WARM INTO LOWER 50S TO
LOWER 60S ON THURSDAY. WINDS WILL BE LIGHT AND EASTERLY. A SMALL
AMOUNT OF CAPE IS EXPECTED TO DEVELOP OVER THE BLACK HILLS IN THE
LATE AFTERNOON...ALONG AN AREA OF FRONTOGENESIS AND MOISTURE
CONVERGENCE. THEREFORE...THE HILLS COULD SEE SOME LIGHT RAIN SHOWERS
THURSDAY AFTERNOON. THE POSSIBILITY FOR FOG LOOKS A LITTLE BETTER
EARLY FRIDAY MORNING WITH HIGHER RH PREDICTED...BUT WILL LET LATER
SHIFTS DECIDE ON WHETHER TO ADD IT.
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 221 PM MDT WED MAR 27 2013
RIDGE TO THE WEST WILL WEAKEN BY THE WEEKEND AS UPPER
LOW SLIDES SLOWLY SOUTHEAST ACROSS SOUTH CENTRAL CANADA. CYCLONIC
FLOW AROUND THE LOW WILL BRING AN UPPER LEVEL DISTURBANCE THROUGH
THE AREA FRIDAY NIGHT AND SATURDAY. FRIDAY WILL BE THE MILDEST DAY
OF THE WEEK...WITH HIGH TEMPERATURES IN THE MID 50S TO MID 60S. A
FEW SHOWERS ARE POSSIBLE OVER THE BLACK HILLS FRIDAY AFTERNOON AS
THE DISTURBANCE APPROACHES. WITH SOME WEAK INSTABILITY IN
PLACE...WOULD NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS LATE
FRIDAY INTO FRIDAY EVENING FROM THE BLACK HILLS AREA INTO SOUTHERN
SD. OTHERWISE...WILL KEEP CHANCE FOR MOSTLY RAIN SHOWERS...WITH LATE
NIGHT/EARLY MORNING SNOW SHOWERS POSSIBLE OVER NORTHERN AND WESTERN
PORTIONS OF THE CWA.
BEYOND SATURDAY...THE FORECAST REMAINS UNCERTAIN WITH AN UPPER LOW
MOVING EAST ACROSS THE SOUTHWESTERN CONUS AND A STRONGER UPPER LOW
ACROSS CENTRAL CANADA BRINGING DEEP NORTHWEST FLOW ACROSS THE
REGION. ADDITIONAL WEAKER DISTURBANCES IN THE NORTHWESTERLY FLOW
WILL MOVE ACROSS THE REGION THROUGH SUNDAY...SO WILL KEEP SOME
SLIGHT CHANCES FOR SHOWERS ACROSS THE CWA. DRIER CONDITIONS ARE
EXPECTED FOR THE EARLY WORK WEEK AS A COLD CANADIAN AIRMASS PUSHES
INTO THE NORTHERN PLAINS. HAVE DROPPED TEMPS FOR THIS PERIOD...BUT
MAY NEED TO BE DROPPED FURTHER IF TRENDS CONTINUE TOWARD COLDER AIR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1059 PM MDT WED MAR 27 2013
VFR CONDITIONS WILL DOMINATE THROUGH THURSDAY EVENING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...POJORLIE
LONG TERM...13
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
404 AM CDT THU MAR 28 2013
.DISCUSSION...
CURRENT UPPER AIR ANALYSIS DEPICTS UPPER TROUGHS OVER THE
NORTHEAST CONUS...NORTHWEST CANADA AND THE CENTRAL PACIFIC OCEAN
WITH WEAK RIDGING ACROSS THE WESTERN CONUS. THIS PLACES NORTH
TEXAS UNDER MODERATE WESTERLY FLOW ALOFT. AT THE SURFACE...A
SURFACE LOW HAS DEVELOPED ACROSS EASTERN NEW MEXICO WITH A SURFACE
TROUGH EXTENDING TO THE NORTHEAST INTO THE TEXAS PANHANDLE AND
INTO CENTRAL OKLAHOMA. BREEZY SOUTHERLY WINDS IN THE LOW LEVELS OF
THE ATMOSPHERE ARE EXPECTED ONCE AGAIN TODAY. LOW CLOUDS HAVE
DEVELOPED TO OUR SOUTH AND WILL CONTINUE TO STREAM NORTHWARD THIS
MORNING. WEST WINDS AT 800 MB HAVE BROUGHT WARMER TEMPERATURES
ALOFT...AND A STRONG CAPPING INVERSION IS NOW IN PLACE. THIS
INVERSION SHOULD PREVENT THE LOW CLOUDS FROM COMPLETELY MIXING OUT
TODAY...AND CLOUDS SHOULD BE AROUND FOR MOST OF THE DAY.
WITHIN THE WESTERLY FLOW ALOFT...A COUPLE OF WEAK EMBEDDED
DISTURBANCES ARE EXPECTED TO MOVE THROUGH OKLAHOMA. THE FIRST ONE
WILL MOVE THROUGH THIS AFTERNOON...BUT WITH WEAK LIFT FOR OUR AREA AND
THE STRONG CAP IN PLACE...RAIN CHANCES WILL BE MINIMAL. THE NAM
AND RAP ARE MIXING US OUT A BIT MORE THAN THE GFS AND ACTUALLY
SHOW A SMALL AMOUNT OF CAPE UNDER THE CAP. THIS COULD LEAD TO A
FEW SHOWERS LATE THIS AFTERNOON...BUT CONFIDENCE WASNT HIGH
ENOUGH TO MENTION ANYTHING IN THE FORECAST. A SECOND WEAK
SHORTWAVE WILL AGAIN MOVE THROUGH OKLAHOMA LATE TONIGHT. THE BEST
CHANCES OF RAIN SHOULD BE IN OKLAHOMA...WHERE THE BEST LIFT AND
SURFACE TROUGH WILL BE LOCATED. COULD SEE A COUPLE OF SHOWERS OR
STORMS ALONG THE RED RIVER...AND WILL CONTINUE WITH A 20 POP
THERE.
THE STRONG CAP WILL CONTINUE TO HAVE A HOLD ON OUR FORECAST FOR
FRIDAY. THE SURFACE LOW WILL HAVE MOVED A BIT FURTHER EAST...AND
THE BEST CHANCE FOR THE CAP TO BREAK WOULD BE TO THE EAST OF THE
LOW NEAR CHILDRESS. IF THIS WERE TO OCCUR...WE COULD SEE ACTIVITY
MOVE INTO THE NORTHWEST ZONES FRIDAY EVENING. BUT AGAIN...THE CAP
REMAINS IN PLACE AND ACTIVITY WOULD NOT BE EXPECTED TO THRIVE
LONG. WILL CONTINUE WITH A 30 POP FOR THE NORTHWESTERN ZONES AND
20S FOR THE REST OF THE NORTHERN HALF OF THE CWA.
FOR SATURDAY...THE NAM COMPLETELY ERODES THE CAP AND HAS PRECIP FOR
THE AREA. HOWEVER...THIS IS FEEDBACK FROM THE NAM BRINGING IN
PRECIP THROUGH THE REGION FROM THE FRIDAY NIGHT SYSTEM. BASICALLY
THE NAM IS COOLING THE WARM LAYER AS THE MODEL IS COMPUTING RAIN
EVAPORATING WITHIN THIS LAYER. THEREFORE AM LESS OPTIMISTIC THAN
THE NAM FOR POPS SATURDAY...AS CONFIDENCE IS NOT HIGH WITH THE
FRIDAY SYSTEM BRINGING WIDESPREAD RAIN FRIDAY NIGHT.
HOWEVER...SOME STORMS ARE POSSIBLE...AND ANY STORMS THAT DEVELOP
TO OUR WEST NEAR THE SURFACE LOW...WOULD HAVE MODERATE SHEAR AND
1500+ J/KG OF CAPE TO WORK WITH. A COUPLE OF STRONG TO SEVERE
STORMS ARE POSSIBLE.
ON SUNDAY...THE UPPER LOW CURRENTLY OVER NORTHWEST CANADA WILL
PUSH INTO THE CENTRAL PLAINS AND DRIVE A COLD FRONT SOUTHWARD. THE
UPPER LOW CURRENTLY OVER THE CENTRAL PACIFIC OCEAN WILL BE MOVING
ONSHORE CENTRAL CALIFORNIA AT THE SAME TIME. AS THE MAIN FORCING
OF THE NORTHERN UPPER LOW SHIFTS EAST...MODELS NOW ADVERTISE THE
COLD FRONT STALLING IN OKLAHOMA...DUE TO THE APPROACHING TROUGH
FROM THE WEST. PREVIOUS MODEL RUNS BROUGHT THE FRONT THROUGH THE
CWA AND HAD TO ADJUST POPS NORTHWARD AND KEEP THE HIGHEST POPS
NORTH OF THE I-20 CORRIDOR...CLOSEST TO THE STALLED FRONTAL
BOUNDARY.
THIS FRONT WILL QUICKLY SURGE NORTHWARD SUNDAY NIGHT AS THE WEST
COAST UPPER LOW PUSHES EAST. HOWEVER...AT THE SAME TIME...ANOTHER
IMPULSE ON THE BACKSIDE OF THE NORTHERN UPPER LOW WILL PUSH
THROUGH THE PLAINS...DRIVING A STRONGER FRONT SOUTH MONDAY. MODELS
ARE FASTER WITH THIS FRONT...SWEEPING IT THROUGH THE CWA MONDAY
AFTERNOON AND EVENING. WITH THIS QUICKER TIMING...HAD TO DECREASE
TEMPERATURES MONDAY NIGHT AND TUESDAY.
MAJOR DISCREPANCIES BETWEEN THE GFS AND ECMWF ARE APPARENT FOR
TUESDAY WITH THE HANDLING OF THE WEST COAST TROUGH. MODELS ARE
CONSISTENT WITH THE WEAKENING OF THE LOW...BUT THE ECMWF IS MOST
AGGRESSIVE WITH THIS WEAKENING TREND...AND MOVES IT THROUGH THE
AREA WEDNESDAY. THE GFS IS A BIT STRONGER THAN THE ECMWF AND
BRINGS THE TROUGH THROUGH TUESDAY WITH MORE PRECIP. THE ECMWF
WOULD THUS HAVE LESS PRECIP AS MOISTURE WOULD BE SCOURED OUT
BEHIND THE FRONT GIVEN THE LATER TIMING. NEVERTHELESS...WITH BOTH
MODELS WEAKENING THE LOW...WIDESPREAD RAIN CHANCES FOR TUESDAY
DONT APPEAR AS HIGH AS YESTERDAY. TEMPERATURES TUESDAY AND
WEDNESDAY BEHIND THE FRONT WILL BE IN THE 50S FOR HIGHS AND
30S/40S FOR LOWS.
HAMPSHIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 69 57 72 59 76 / 5 10 10 20 30
WACO, TX 71 57 73 59 75 / 5 5 10 10 20
PARIS, TX 67 54 69 58 72 / 5 20 20 20 30
DENTON, TX 69 55 72 57 76 / 5 10 20 30 30
MCKINNEY, TX 69 55 69 58 74 / 5 10 20 20 30
DALLAS, TX 71 57 73 59 75 / 5 10 10 20 30
TERRELL, TX 69 55 71 59 73 / 5 5 10 20 30
CORSICANA, TX 70 56 71 59 73 / 5 5 10 10 30
TEMPLE, TX 70 56 72 59 76 / 5 5 10 10 20
MINERAL WELLS, TX 71 55 73 56 80 / 5 10 10 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
126 AM EDT THU MAR 28 2013
.SYNOPSIS...
AN UPPER LEVEL AREA OF LOW PRESSURE OFF THE MID ATLANTIC COAST
WILL MAINTAIN A CHILLY NORTHWEST FLOW OF AIR ACROSS THE REGION
THROUGH THURSDAY. FRIDAY AND SATURDAY...HIGH PRESSURE BUILDS INTO
THE REGION THEN MOVES OFFSHORE ALLOWING TEMPERATURES TO SLOWLY
MODERATE INTO THE WEEKEND. A COLD FRONT WILL APPROACH THE REGION
EARLY NEXT WEEK BRINGING THE NEXT CHANCE OF SHOWERS.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1010 PM EDT WEDNESDAY...
UPSLOPE SNOW SHOWERS CONTINUE OVER PORTIONS OF SE WV...WITH
FLURRIES SCATTERED EAST TO THE BLUE RIDGE. ANOTHER VORT TRACKING
ACROSS MISSOURIS PROGGED TO IMPACT THE NC MTNS AFTER 06Z. THE
LOCAL WRF HINTS AT THIS IN TERMS OF ADJUSTING ITS HIGHER QPF FROM
SE WV BACK TOWARD THE MTN EMPIRE OF SW VA AND HIGH COUNTRY OF NC.
AFTER A LULL THIS EVENING...SHOULD SEE SNOW SHOWERS INCREASE AGAIN
OVERNIGHT IN THE MOUNTAINS OF NORTH CAROLINA. OVERALL...THE FLOW
SUGGEST SOME BANDING POSSIBLE EXTENDING INTO THE NEW RIVER VALLEY.
AMOUNTS WILL BE AN INCH OR LESS...WITH LOCALLY 2 INCHES OVER THE
TYPICAL WRN SLOPES OF GREENBRIER COUNTY WV. HAVE A SPECIAL WEATHER
STATEMENT OUT TO COVER SLICK ROADS...AND WILL ALSO BE DEALING WITH
SOME BLACK ICE ISSUES...AS TEMPS FALL BELOW FREEZING.
WINDS STAYING UP JUST ENOUGH TO KEEP TEMPS FROM DROPPING FAR BUT
STILL LOOKING AT UPPER TEENS TO LOWER 20S WV MTNS TO MID TO UPPER
20S REST OF THE MTNS AND LOWER 30S OUT EAST.
PREVIOUS VALID DISCUSSION...
WATER VAPOR LOOP SHOWED THE NEXT FEATURE MOVING SOUTH THROUGH THE
EASTERN GREAT LAKES. MODELS HAVE THIS SHORT WAVE MOVING THROUGH
EASTERN VIRGINIA ON THURSDAY MORNING.
850 MB WINDS THROUGH THE PERIOD REMAIN IN THE 20 TO 35 KNOT RANGE
FROM THE NORTHWEST. RAP GUIDANCE AND LOCAL WRF BOTH INDICATED
SOME BANDS OF SNOW SHOWERS MAY DEVELOP BEFORE MIDNIGHT TONIGHT.
HAVE ADDED MORE CLOUD COVER IN THE EAST THURSDAY MORNING...WITH
THE NEXT SHORT WAVE...OTHERWISE PERSISTENT DOWNSLOPE FLOW WILL
LIMIT COVER COVER AND SHOWERS EAST OF THE FOOTHILLS OVERNIGHT.
HOWEVER...TEMPERATURES ALOFT REMAIN COLD ENOUGH AND LAPSE RATES
DURING THE DAY ARE LARGE ENOUGH THAT MORE SCATTERED STRATOCUMULUS
WILL FORM AGAIN BY LATE THURSDAY MORNING.
STAYED ON THE COOL SIDE OF GUIDANCE FOR LOWS TONIGHT AND
ESPECIALLY HIGHS ON THURSDAY.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 200 PM EDT WEDNESDAY...
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE REGION WILL CONTINUE TO BE
IN A PATTERN OF NORTHWEST FLOW. HOWEVER...THE VARIOUS SHORTWAVE
TROUGHS WITHIN THE LARGER SYNOPTIC PATTERN WITH BE PROGRESSIVELY
FARTHER NORTH OF THE REGION. ALSO...THE PRESSURE GRADIENT WILL BE
BROADENING...AND THEREFORE...THE MAGNITUDE OF THE UPSLOPE WINDS WILL
BE LESS. WHILE WE WILL STILL BE FORECASTING UPSLOPE SNOW
SHOWERS/FLURRIES FOR SOUTHEAST WEST VIRGINIA...THE IMPACT WILL BE
ALSO BE DECREASING IN TIME. THE ONE CLINKER IN THIS SCENARIO IS THE
POTENTIAL FOR SOME LIGHT PRECIPITATION ACROSS THE SOUTHWEST PART OF
THE FORECAST AREA FRIDAY NIGHT. THE 12Z/8AM GFS/NAM/CANADIAN
SOLUTIONS HAVE BEEN HINTING AT A WEAK DISTURBANCE PROGRESSING
THROUGH KY/TN AND INTO SW VA/NW NC. WHILE IT HAS BEEN WEAK...IT HAS
BEEN CONSISTENT FROM MODEL RUN TO MODEL RUN. OUR CURRENT FORECAST
HAS THIS FEATURE REFLECTED LATE FRIDAY NIGHT INTO EARLY SATURDAY
MORNING TO A MINIMAL DEGREE. WE WILL SHOW AN INCREASE IN THE
POTENTIAL OF A LIGHT MIX OF WINTRY PRECIPITATION IN THIS FORECAST
PACKAGE...WHILE STILL MAINTAINING RELATIVELY LOW CHANCES.
BY SATURDAY INTO SATURDAY NIGHT...MODEL GUIDANCE IS SUGGESTING WHAT
HAS BEEN AN EXTENDED PERIOD OF NORTHWEST FLOW COMES TO AN END AS AN
UPPER LEVEL SHORTWAVE RIDGE BUILDS ACROSS THE REGION...AND THE
PREVAILING FLOW BECOMES SOUTHWEST. RIDGING OVER THE REGION WILL BE
BE BRIEF AS IT DEVELOPS AS A RESULT OF OUR NEXT SHORTWAVE TROUGH
PROGRESSING THROUGH THE CENTER OF THE COUNTRY. WITHIN THIS SOUTHWEST
FLOW WILL BE A NEW SOURCE OF MOISTURE...THE GULF OF MEXICO. WE WILL
EXPERIENCE PATCHY LIGHT RAIN AND INCREASED CLOUD COVER MOVING INTO
THE SOUTHWEST PART OF THE AREA AS EARLY AS SATURDAY EVENING.
THROUGHOUT SATURDAY NIGHT...THE PRECIPITATION WILL PROGRESS
NORTH...AND EXPAND IN COVERAGE...HOWEVER...AMOUNTS ARE EXPECTED TO
BE ON THE LIGHT SIDE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 1245 PM EDT WEDNESDAY...
ON SUNDAY...THE TREND WILL CONTINUE FOR INCREASING CHANCES OF RAIN
THROUGHOUT THE MORNING AND AFTERNOON...WITH HEAVIER SHOWERS POSSIBLE
ACROSS THE MOUNTAINS DURING THE AFTERNOON THANKS TO THE APPROACH OF
A COLD FRONT. TEMPERATURES WILL CONTINUE TO TREND MILDER. LOWS
SUNDAY MORNING WILL BE IN THE LOWER 40S ACROSS MUCH OF THE
REGION...WITH HIGHER RIDGE TOPS OF SE WV IN THE MID TO UPPER 30S. ON
SUNDAY...LOW TO MID 50S FOR HIGHS ARE EXPECTED IN THE
MOUNTAINS...WITH UPPER 50S TO AROUND 60 EAST OF THE BLUE RIDGE.
SUNDAY NIGHT...THE COLD FRONT CROSSES THE REGION WITH ITS ASSOCIATED
PRECIPITATION...AND THEN COLDER AIR STARTS TO RETURN. BY LATE SUNDAY
NIGHT...ENOUGH COLD AIR MAY BRING SOME SNOW SHOWERS MIXED WITH THE
RAIN SHOWERS TO WESTERN GREENBRIER CO WV.
MONDAY THROUGH WEDNESDAY...THE REGION REMAINS WITH A NORTHWEST FLOW
PATTERN DURING THIS PERIOD. THIS WILL PUT US BACK IN AN UPSLOPE
PATTERN WITH A MIX OF RAIN AND SNOW SHOWERS ACROSS SE WV. THE GFS IS
SUGGESTING TUESDAY MAY BE A DAY WITH PRECIPITATION ACROSS A WIDER
SWATH OF THE AREA IN ADDITION TO THE UPSLOPE PRECIPITATION. ITS
SOLUTION BRINGS A SOUTHERN STREAM SYSTEM ALONG THE GULF COAST STATES
AND THEN NORTH ALONG THE COAST ALONG THE FRONTAL BOUNDARY THAT WOULD
HAVE CROSS OUR REGION ON SUNDAY. OUR FORECAST WILL OFFER SOME
CREDENCE TO THIS POTENTIAL...BUT ONLY WITH A SLIGHT CHANCE OF
RAIN SHOWERS IN THE EAST.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 105 AM EDT THURSDAY...
SIMILAR TO LAST NIGHT...NEXT ROUND OF SNOW SHOWERS AND FLURRIES
SPILLING ACROSS SE WVA TOWARD THE BLUE RIDGE ATTM ALTHOUGH NOT AS
INTENSE AT THIS POINT. HOWEVER AT LEAST ENOUGH TO CAUSE PERIODIC
MVFR/IFR CONDITIONS AT KBLF AND AT TIMES AROUND KLWB FOR A FEW
HOURS BEFORE DAYBREAK. MVFR CIGS ALSO LIKELY AT KBCB WHERE BRIEF
REDUCTIONS IN VSBY TO MVFR ALSO POSSIBLE OVER THE NEXT FEW HOURS.
THUS ENOUGH CONFIDENCE TO HAVE MOSTLY MVFR CIGS/VSBYS FAR WEST AND
TEMPO IN AN IFR GROUP FOR A HEAVIER -SHSN ESPCLY AROUND KBLF
OVERNIGHT. FEW FLURRIES ALSO POSSIBLE INTO KROA BUT THINKING
MAINLY VFR CIGS THERE WITH SKC TO ONLY SCTD CLOUDS EAST THROUGH
EARLY THURSDAY MORNING.
WINDS WILL BE SETTLING DOWN EAST OF THE MOUNTAINS OVERNIGHT WHILE
STAYING AROUND 10 KNOTS IN THE MTNS WITH PERHAPS AN OCCASIONAL
GUST TO 20 KNOTS.
AFTER SUNRISE THE WINDS PICK BACK UP WITH GUSTS 20 TO 30 KNOTS.
EXPECT VFR FOR MOST OF THE AREA...WHILE LIGHT SNOW SHOWERS
ACCOMPANIED BY LOWER CEILINGS WILL REMAIN IN WEST VIRGINIA.
HOWEVER SHOULD SEE IMPROVING CIGS AFTER 15Z/11AM AS DRIER AIR
FINALLY STARTS TO MIX IN BEHIND THE DEPARTING UPPER LOW THAT
SHOULD BEGIN TO PIVOT EAST BY AFTERNOON.
UPSLOPE CLOUDS MAY MAKE A BRIEF RETURN OVERNIGHT AS ANOTHER FAINT
WAVE SLIDES ACROSS FROM THE NW BUT MAINLY HIGH END MVFR TO VFR
CIGS AT KBLF/KLWB THURSDAY NIGHT.
BY FRIDAY THE LOW LEVEL MOISTURE ERODES AND PUTS AN END TO THE
UPSLOPE SNOW SHOWERS ACROSS THE MOUNTAINS AND CLEARS OUT THE LOW
LEVEL CU. SURFACE HIGH PRESSURE BUILDS IN FOR FRIDAY AND SATURDAY
RESULTING IN LIGHTER WINDS AND VFR CONDITIONS.
CLOUDS INCREASE AGAIN AHEAD OF ANOTHER FRONT ON SATURDAY NIGHT.
DEEPER MOISTURE ALONG WITH THE THREAT OF SHOWERS WILL HOLD OFF
UNTIL SUNDAY WHEN MVFR CEILINGS AND VISIBILITIES OR WORSE MAY
DEVELOP. A STRONG COLD FRONT IS EXPECTED TO CROSS THROUGH THE
REGION EARLY NEXT WEEK...RETURNING MOUNTAIN SNOW SHOWERS AND
ASSOCIATED MVFR CONDITIONS LATER MONDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...AMS/WP
SHORT TERM...DS
LONG TERM...DS
AVIATION...AMS/JH/WP
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1003 AM CDT THU MAR 28 2013
.DISCUSSION...
ISSUED 1002 AM CDT THU MAR 28 2013
HIGH PRESSURE AXIS CURRENTLY DRAPED NORTHWEST-SOUTHEAST ACROSS THE
FORECAST AREA. SOME WARM AIR ADVECTION CONTINUES TO CREATE
CLOUDINESS ACROSS MISSOURI...AND SATELLITE AND LATEST RAP MODEL
ANALYSIS TRACKS THIS LARGELY SOUTHEAST THROUGH THE AFTERNOON.
MAIN CONCERN IS WITH TEMPERATURES TODAY. VISIBLE SATELLITE IMAGERY
SHOWING LOCATIONS NORTHWEST OF A HAVANA TO LACON LINE...AS WELL AS
SOUTH OF AN EFFINGHAM TO PARIS LINE...WITH LITTLE OR NO SNOW
COVER. THESE AREAS WILL BE THE MILDER LOCATIONS TODAY. HAVE MADE
SOME MINOR UPWARD ADJUSTMENTS TO TEMPERATURES IN THE NORTHWEST
CORNER OF THE CWA...BUT LEFT MUCH OF THE REMAINDER OF THE AREA
ALONE FOR NOW.
GEELHART
&&
.AVIATION...
ISSUED 650 AM CDT THU MAR 28 2013
VFR CONDITIONS SHOULD CONTINUE ACROSS THE CENTRAL IL AIRPORTS
THROUGH 12Z/7 AM FRI AS 1029 MB ELONGATED HIGH PRESSURE RIDGE
STAYS NEAR IL. FEW-SCT MID LEVEL CLOUDS AROUND 10K FT TO OCCUR
TODAY AT SPI AND DEC. CURULE SHOWS FEW IF ANY CUMULUS CLOUDS TODAY
OVER CENTRAL IL...AND MAINLY CONFINED TO INDIANA AND MO INTO SW IL.
HAVE BROKEN MID LEVEL CLOUDS OF 7-12K FT WITH SCATTERED CLOUDS
FROM 3-6K FT SPREADING NE INTO CENTRAL IL BETWEEN 03Z-09Z
TONIGHT. MVFR CEILINGS SHOULD STAY SW OF CENTRAL IL AIRPORTS
OVERNIGHT. LIGHT AND VARIABLE WINDS THIS MORNING TO BECOME EAST
AROUND 5 KTS TONIGHT. AIRMASS FAIRLY DRY WITH DEWPOINTS IN THE 20S
NEXT 24 HOURS SO DO NOT THINK FOG WILL FORM OVERNIGHT.
07
&&
.PREV DISCUSSION...
ISSUED 316 AM CDT THU MAR 28 2013
SHORT TERM...TODAY THROUGH FRIDAY NIGHT
HIGH PRESSURE IN FIRM CONTROL OF THE WEATHER PATTERN ACROSS THE
AREA THIS MORNING PRODUCING CLEAR AND CALM CONDITIONS. THE RIDGE
AXIS IS PROGGED TO MOVE LITTLE THROUGH THIS AFTERNOON AND WILL
PROVIDE A SUNNY DAY WITH TEMPS A FEW DEGREES WARMER THAN YESTERDAY
DUE TO AIRMASS MODIFICATION AND MORE BARE GROUND FOR THE STRONG
LATE MARCH SUN TO WORK ON. TONIGHT...ELEVATED WARM AIR ADVECTION
WILL BE TAKING PLACE TO THE NORTH OF A WARM FRONT WHICH WILL BE
STRETCHED WEST-EAST OVER THE SOUTHERN THIRD OF MISSOURI. FAIRLY
STRONG ISENTROPIC LIFT NOTED ON 290K SFC 06-12Z FRIDAY OVER ERN
MO/SW IL COINCIDENT WITH WEAK DPVA OFF A SHORTWAVE RIDING
SOUTHEAST FROM IA SHOULD BE SUFFICIENT TO DEVELOP SCATTERED
SHOWERS. QUESTIONS REMAIN HOW FAR NORTHEAST THIS ACTIVITY WILL
DEVELOP INTO SUBSIDENCE REGION OF LINGERING RIDGE AND DRIER AIR
OVER CENTRAL IL...BUT TRENDS OVER THE PAST 24 HOURS SUGGEST
INTRODUCING LOW CHANCE POPS LATE TONIGHT AND FRIDAY MORNING SOUTH
OF I-70. NAM FORECAST SOUNDINGS SHOW TEMPS ABOVE 0 C IN THE LOWEST
2500 FT SO ANY PRECIP SHOULD FALL AS RAIN. QUIET WEATHER THEN
EXPECTED FRIDAY AFTERNOON AND NIGHT AHEAD OF THE NEXT WEATHER
SYSTEM WHICH WILL BRING MORE WIDESPREAD RAINS THIS WEEKEND.
LONG TERM...SATURDAY THROUGH WEDNESDAY
COLD FRONT STILL SLATED TO SHIFT ACROSS THE CWA LATE
SATURDAY/EARLY SUNDAY BRINGING A GOOD CHANCE OF RAIN. AHEAD OF THE
FRONT...SOUTHERLY SURFACE FLOW SHOULD ALLOW READINGS TO GET UP
INTO THE MID/UPPER 50S. CLOUDS WILL BE ON THE INCREASE FROM THE NW
BY AFTERNOON AND HAVE CHANCE POPS NW OF THE IL RIVER. GOOD MODEL
AGREEMENT ON FRONTAL TIMING WHICH BRINGS HIGHEST RAIN COVERAGE
OVERNIGHT. PROGRESSIVE FRONT SO MAINLY QUARTER TO HALF INCH
TOTALS. THE RAIN SHOULD PUSH INTO INDIANA BY EARLY MORNING...AND
WITH THE MAIN COLD SURGE STAYING NORTH THROUGH AFTERNOON SUNDAY
NOW LOOKS LIKE A DECENT DAY WITH HIGHS GETTING BACK UP INTO THE
50S. SECONDARY COLD FRONT HITS SUNDAY EVENING BRINGING ANOTHER
BATCH OF MODIFIED ARCTIC AIR...WITH 850 MB TEMPS CRASHING TO -6 TO
-10 C ON MONDAY. AN IMPULSE RIDING EAST FROM THE PLAINS WILL
LIKELY SPREAD PRECIP NORTH OVER THE SOUTHERN FRINGE OF THE COLDER
AIRMASS...AFFECTING PARTS OF THE MIDWEST AND OHIO VALLEY ON
MONDAY. WITH STRENGTH OF THE HIGH BUILDING SOUTH THROUGH THE
PLAINS FEEL MOST OF THIS ACTIVITY WILL BE SUPPRESSED SOUTH OF THE
LOCAL AREA...HOWEVER MODEL CONSENSUS KEEPS LOW CHANCE POPS OVER
THE SOUTHERN HALF OF THE CWA SUNDAY NIGHT AND MONDAY. IF ACTIVITY
DOES MATERIALIZE THIS FAR NORTH PRECIP TYPE WOULD BE IN QUESTION
GIVEN MARGINAL SFC TEMPS. LATE SEASON ARCTIC HIGH WILL THEN
DOMINATE THE WEATHER PATTERN ACROSS THE AREA THROUGH MID-WEEK
PRODUCING DRY AND COOL CONDITIONS.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
854 AM CDT THU MAR 28 2013
.DISCUSSION...
332 AM CDT
WHILE THE FORECAST IS GENERALLY QUIET...THERE ARE SOME CHALLENGES.
THESE CONTINUE TO BE TEMPERATURES AND WEIGHING THE EFFECTS OF THE
LAKE BREEZE FOR DOWNTOWN CHICAGO AND OTHER NEARBY
LOCATIONS...FOLLOWED BY RAIN LIKELIHOOD SATURDAY NIGHT AND THE
PATTERN BEHIND THE COLD FRONT.
WHILE THE UPPER AND MID-LEVEL WIND FLOW REMAINS NORTHWESTERLY...THE
AIR MASS IS BECOMING MORE PACIFIC ORIGIN THAN MODIFIED ARCTIC PER
UPPER AIR ANALYSES. THE HIGH PRESSURE RIDGE IS CENTERED NEAR THE
MISSISSIPPI RIVER EARLY THIS MORNING AND WILL MOVE OVER THE AREA
BY AFTERNOON AND PERSIST THROUGH LATE IN THE DAY FRIDAY. THIS
LIGHT PRESSURE GRADIENT FORCE ALONG WITH MORE SUNSHINE TOWARD
WARMING TEMPERATURES OVER LAND WILL CERTAINLY FOSTER LAKE BREEZE
DEVELOPMENT. IT IS LIKELY THIS WILL BE EARLIER THAN THE PAST TWO
DAYS GIVEN THE SETUP. THIS IS SUPPORTED BY THE HRRR WHICH STARTS
THE LAKE BREEZE NEAR 11 AM. HAVE CONTINUED TO REFLECT A DROPPING
AND THEN STABILIZING TEMPERATURE TREND NEAR THE LAKE SHORE...WITH
AFTERNOON READINGS LIKELY IN THE UPPER AND MAYBE EVEN MID 30S. AS
FOR THE REMAINDER OF THE FORECAST AREA...SOME CU IS POSSIBLE
NAMELY OVER NE IL AND NW IN AS THE LAST OF THE COLD AIR ALOFT
SCOOTS OUT. THE WARM AIR ADVECTION IN ITS PLACE AND FURTHER MIXING
SHOULD ALLOW FOR WIDESPREAD HIGHS IN THE MID 40S...BASICALLY THE
HIGHS OF YESTERDAY PLUS THREE TO FOUR DEGREES.
ANOTHER SHARP UPPER TROUGH WILL DIG INTO THE GREAT LAKES REGION BY
EARLY NEXT WEEK...WITH A FIRST SEEMINGLY WELL-DEFINED SHORT WAVE
AND SURFACE TROUGH ADVANCING THROUGH THE AREA SATURDAY NIGHT. THE
NAM...GFS...AND EC ALL AGREE ON A SURFACE LOW RESPONSE FROM
NORTHERN MO THROUGH OUR AREA DURING SATURDAY NIGHT...WITH A
FOCUSED MOIST ADVECTION AND CONVERGENCE AREA MOVING ACROSS WITHIN
FAIRLY GOOD UPPER FORCING. HAVE CONTINUED TO INCH UP POPS FOR
SATURDAY EVENING. SOME GUIDANCE INCLUDING THE EC AND NAM ALREADY
SPREAD RAIN INTO THE WESTERN AND SOUTHWESTERN FORECAST AREA AS
EARLY AS MID TO LATE AFTERNOON AND HAVE CONTINUED TO ACCOUNT FOR
THAT. MORE MEMBERS OF THE GEFS SHOW POTENTIAL FOR OVER A QUARTER
OF AN INCH BUT VERY FEW INCLUDING IN THE SREF GIVE OVER ONE HALF
AN INCH.
TEMPERATURES IN ADVANCE OF THE FRONT LOOK TO EXCEED 50 AREA-WIDE
ON SATURDAY WITH A MILD NIGHT AS THE CLOUDS AND THE BOUNDARY PASS.
SUNDAY TEMPERATURES IN THE UPPER 40S TO MID 50S ARE LOOKING MORE
CONFIDENT THANKS TO A HIGH STARTING POINT AND THE FIRST COLD FRONT
NOT BRINGING MUCH OF A COLD AIR DUMP. THAT WILL COME SUNDAY NIGHT
WITH A COOL PATTERN TO START NEXT WEEK AS 850 MB TEMPERATURES DROP
ONCE AGAIN TO ONE AND A HALF STANDARD DEVIATIONS BELOW NORMAL /PER
GEFS AND EC FORECASTS/. HAVE ADAPTED LOCAL CLIMATOLOGICAL RESEARCH
FOR THESE 850MB TEMPERATURES OF -10C INTO THE FORECAST...WHICH
INDICATE GOOD POTENTIAL FOR HIGHS TO REMAIN AT OR BELOW 40 IN
CHICAGO...WHICH ALREADY LOOKED PRETTY GOOD IN THE FORECAST. ONE
THING ABOUT NEXT WEEK COMPARED TO THE COOL TEMPERATURES OF EARLIER
THIS WEEK IS THAT WHILE UNDER CYCLONIC FLOW AGAIN WE WILL BE LESS
ENTRENCHED AND THUS LESS FAVORED FOR CONTINUOUS STARTOCU. WE
SHOULD HAVE SOME DURING THE DAYS BUT WE ARE FURTHER FROM THE
CYCLONIC CENTER WHICH WILL BE UP IN QUEBEC ALREADY BY MONDAY
AFTERNOON. NO SIGN OF A MAJOR WARM-UP BUT A GRADUAL ONE LATE NEXT
WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE BREEZE WILL BE DEVELOPING THIS AFTERNOON. THE QUESTION IS
WHETHER IT WILL MOVE INLAND FAR ENOUGH TO PASS THROUGH MDW AND
ORD.
PAW
//DISCUSSION...UPDATED 12Z...
A RIDGE OF HIGH PRESSURE EXTENDING FROM WESTERN HUDSON BAY SOUTH
ACROSS THE UPPER MIDWEST AND MID AND LOWER MS VALLEY TO THE GULF
OF MEX HAS BEEN MOVING VERY SLOWLY E FROM THE PLAINS TOWARD THE
LOCAL AREA OVER THE LAST FEW DAYS. WITH ITS CONTINUED GRADUAL
DRIFT TO THE E THE RIDGE AXIS IS FINALLY PROGGED TO MOVE OVER THE
LOCAL AREA DURING THIS AFTERNOON AND EVENING.
WITH THE RIDGE AXIS VERY NEAR OR OVERHEAD THIS AFTERNOON AND
EVENING THE CURRENT LIGHT NW TO NNW LOW LEVEL FLOW WILL WEAKEN
EVEN FURTHER AND BASICALLY BE NIL BY 00Z. WHILE A VERY WEAK LAKE
BREEZE DID DEVELOP WED IT DID NOT MAKE IT MORE THAN A MILE OR TWO
INLAND. WITH AFTERNOON TEMPERATURES FORECAST SOME 3 TO 5 DEG F
WARMER THAN THOSE REACHED WED AND VERY LITTLE LOW LEVEL FLOW TO
IMPEDE A FURTHER INLAND ADVANCE OF THE LAKE BREEZE DO EXPECT IT
TO REACH MDW AROUND 22Z AND MDW AROUND 23Z SHIFTING LIGHT WINDS
FROM OUT OF THE NNW AND N TO OUT OF THE ENE AND NE.
WITH SUNSET AND LOSS OF HEATING THE BOUNDARY WILL WASH OUT
LEAVING WINDS LIGHT VARIABLE OR NIL WITH THE RIDGE AXIS BASICALLY
STILL OVERHEAD AS IT IS NOT PROGGED TO REACH THE IL LAKE SHORE TIL
EARLY FRI MORNING.
SURFACE HEATING AND MARGINAL LOW LEVEL MOISTURE MAY GIVE RISE
TO FEW-SCT STRATOCU MID MORNING THROUGH EARLY AFTERNOON THEN
WARMING IN THE 850-800HPA LAYER CREATES TOO LARGE OF A DEW
POINT DEPRESSION TO SUPPORT ANY DIURNAL CLOUDS. OTHERWISE ONLY
FEW-SCT CIRRUS RIDING OVER A BROAD WESTERN UPPER RIDGE REACHING
THE LOCAL AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN LAKE BREEZE DEVELOPING. LOW TO MEDIUM
CONFIDENCE IN IT PASSING THROUGH MDW OR ORD...AND THE TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT AND SATURDAY...VFR.
* SATURDAY NIGHT....MVFR. RAIN LIKELY.
* SUNDAY...MVFR EARLY...THEN VFR. W-WNW WINDS GUSTING 20-25KT LATE
MORNING THROUGH AFTERNOON.
* SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR.
TRS
&&
.MARINE...
342 AM CDT
A HIGH PRESSURE RIDGE EXTENDING FROM HUDSON BAY S ACROSS THE
UPPER MIDWEST AND MID AND LOWER MS VALLEY TO THE GULF COAST HAS
BEEN MOVING VERY SLOWLY EASTWARD THE LAST FEW DAYS AND WILL
CONTINUE THIS VERY SLOW APPROACH EASTWARD TODAY...WITH THE RIDGE
AXIS FINALLY MOVING OVER LAKE MI TONIGHT. WITH THE RIDGE CLOSE BY
AND EVENTUALLY OVER THE LAKE ONLY LIGHT TO GENTLE BREEZES WILL BE
EXPERIENCED FROM MIDDAY TODAY THROUGH FRIDAY.
WITH THE RIDGE THEN MOVING FURTHER E TO THE LOWER GREAT LAKES AND
THE UPPER OH FRI NIGHT...AND LOW PRESSURE MOVING E ACROSS
NORTHERN MANITOBA TO NORTHERN ONTARIO PUSHING A COLD FRONT
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS WINDS WILL RESULT IN
S TO SW WINDS ESTABLISHING OVERNIGHT FRIDAY AND GRADUALLY
INCREASING TO FRESH SOUTH BREEZES BY SAT AFTERNOON.
THE STRONG COLD FRONT TRAILING SW FROM THE CANADIAN LOW WILL MOVE
ACROSS LAKE MI SUN AND SUN NIGHT LEADING SHIFTING WINDS TO OUT OF
THE W AND NW AND AN INCREASE TO NEAR GALE FORCE OVERNIGHT SUNDAY.
THESE NEAR GALE WINDS WINDS CONTINUE INTO MONDAY AFTERNOON. THERE
IS THE POTENTIAL FOR LOW END GALES ON THE LAKE AFTER THE COLD
FRONT PASSES INTO THE CENTRAL GREAT LAKES LATE SUN NIGHT AND MON
BUT THIS POTENTIAL LOOKS TO BE SMALL AT THIS TIME.
BEHIND THE COLD FRONT HIGH PRESSURE BUILDS FROM SASKATCHEWAN TO
THE CENTRAL PLAINS SUN AND MON. AS THE HIGH MOVES FURTHER TO THE
E ACROSS THE PLAINS NW WINDS ON LAKE MI WILL BEGIN TO GRADUALLY
DIMINISH LATE MONDAY NIGHT AND TUESDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
622 AM CDT THU MAR 28 2013
.DISCUSSION...
332 AM CDT
WHILE THE FORECAST IS GENERALLY QUIET...THERE ARE SOME CHALLENGES.
THESE CONTINUE TO BE TEMPERATURES AND WEIGHING THE EFFECTS OF THE
LAKE BREEZE FOR DOWNTOWN CHICAGO AND OTHER NEARBY
LOCATIONS...FOLLOWED BY RAIN LIKELIHOOD SATURDAY NIGHT AND THE
PATTERN BEHIND THE COLD FRONT.
WHILE THE UPPER AND MID-LEVEL WIND FLOW REMAINS NORTHWESTERLY...THE
AIR MASS IS BECOMING MORE PACIFIC ORIGIN THAN MODIFIED ARCTIC PER
UPPER AIR ANALYSES. THE HIGH PRESSURE RIDGE IS CENTERED NEAR THE
MISSISSIPPI RIVER EARLY THIS MORNING AND WILL MOVE OVER THE AREA
BY AFTERNOON AND PERSIST THROUGH LATE IN THE DAY FRIDAY. THIS
LIGHT PRESSURE GRADIENT FORCE ALONG WITH MORE SUNSHINE TOWARD
WARMING TEMPERATURES OVER LAND WILL CERTAINLY FOSTER LAKE BREEZE
DEVELOPMENT. IT IS LIKELY THIS WILL BE EARLIER THAN THE PAST TWO
DAYS GIVEN THE SETUP. THIS IS SUPPORTED BY THE HRRR WHICH STARTS
THE LAKE BREEZE NEAR 11 AM. HAVE CONTINUED TO REFLECT A DROPPING
AND THEN STABILIZING TEMPERATURE TREND NEAR THE LAKE SHORE...WITH
AFTERNOON READINGS LIKELY IN THE UPPER AND MAYBE EVEN MID 30S. AS
FOR THE REMAINDER OF THE FORECAST AREA...SOME CU IS POSSIBLE
NAMELY OVER NE IL AND NW IN AS THE LAST OF THE COLD AIR ALOFT
SCOOTS OUT. THE WARM AIR ADVECTION IN ITS PLACE AND FURTHER MIXING
SHOULD ALLOW FOR WIDESPREAD HIGHS IN THE MID 40S...BASICALLY THE
HIGHS OF YESTERDAY PLUS THREE TO FOUR DEGREES.
ANOTHER SHARP UPPER TROUGH WILL DIG INTO THE GREAT LAKES REGION BY
EARLY NEXT WEEK...WITH A FIRST SEEMINGLY WELL-DEFINED SHORT WAVE
AND SURFACE TROUGH ADVANCING THROUGH THE AREA SATURDAY NIGHT. THE
NAM...GFS...AND EC ALL AGREE ON A SURFACE LOW RESPONSE FROM
NORTHERN MO THROUGH OUR AREA DURING SATURDAY NIGHT...WITH A
FOCUSED MOIST ADVECTION AND CONVERGENCE AREA MOVING ACROSS WITHIN
FAIRLY GOOD UPPER FORCING. HAVE CONTINUED TO INCH UP POPS FOR
SATURDAY EVENING. SOME GUIDANCE INCLUDING THE EC AND NAM ALREADY
SPREAD RAIN INTO THE WESTERN AND SOUTHWESTERN FORECAST AREA AS
EARLY AS MID TO LATE AFTERNOON AND HAVE CONTINUED TO ACCOUNT FOR
THAT. MORE MEMBERS OF THE GEFS SHOW POTENTIAL FOR OVER A QUARTER
OF AN INCH BUT VERY FEW INCLUDING IN THE SREF GIVE OVER ONE HALF
AN INCH.
TEMPERATURES IN ADVANCE OF THE FRONT LOOK TO EXCEED 50 AREA-WIDE
ON SATURDAY WITH A MILD NIGHT AS THE CLOUDS AND THE BOUNDARY PASS.
SUNDAY TEMPERATURES IN THE UPPER 40S TO MID 50S ARE LOOKING MORE
CONFIDENT THANKS TO A HIGH STARTING POINT AND THE FIRST COLD FRONT
NOT BRINGING MUCH OF A COLD AIR DUMP. THAT WILL COME SUNDAY NIGHT
WITH A COOL PATTERN TO START NEXT WEEK AS 850 MB TEMPERATURES DROP
ONCE AGAIN TO ONE AND A HALF STANDARD DEVIATIONS BELOW NORMAL /PER
GEFS AND EC FORECASTS/. HAVE ADAPTED LOCAL CLIMATOLOGICAL RESEARCH
FOR THESE 850MB TEMPERATURES OF -10C INTO THE FORECAST...WHICH
INDICATE GOOD POTENTIAL FOR HIGHS TO REMAIN AT OR BELOW 40 IN
CHICAGO...WHICH ALREADY LOOKED PRETTY GOOD IN THE FORECAST. ONE
THING ABOUT NEXT WEEK COMPARED TO THE COOL TEMPERATURES OF EARLIER
THIS WEEK IS THAT WHILE UNDER CYCLONIC FLOW AGAIN WE WILL BE LESS
ENTRENCHED AND THUS LESS FAVORED FOR CONTINUOUS STARTOCU. WE
SHOULD HAVE SOME DURING THE DAYS BUT WE ARE FURTHER FROM THE
CYCLONIC CENTER WHICH WILL BE UP IN QUEBEC ALREADY BY MONDAY
AFTERNOON. NO SIGN OF A MAJOR WARM-UP BUT A GRADUAL ONE LATE NEXT
WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LAKE BREEZE DEVELOPMENT DURING THE AFTERNOON AND HOW FAR INLAND
IT REACHES BY EVENING.
TRS
//DISCUSSION...UPDATED 12Z...
A RIDGE OF HIGH PRESSURE EXTENDING FROM WESTERN HUDSON BAY SOUTH
ACROSS THE UPPER MIDWEST AND MID AND LOWER MS VALLEY TO THE GULF
OF MEX HAS BEEN MOVING VERY SLOWLY E FROM THE PLAINS TOWARD THE
LOCAL AREA OVER THE LAST FEW DAYS. WITH ITS CONTINUED GRADUAL
DRIFT TO THE E THE RIDGE AXIS IS FINALLY PROGGED TO MOVE OVER THE
LOCAL AREA DURING THIS AFTERNOON AND EVENING.
WITH THE RIDGE AXIS VERY NEAR OR OVERHEAD THIS AFTERNOON AND
EVENING THE CURRENT LIGHT NW TO NNW LOW LEVEL FLOW WILL WEAKEN
EVEN FURTHER AND BASICALLY BE NIL BY 00Z. WHILE A VERY WEAK LAKE
BREEZE DID DEVELOP WED IT DID NOT MAKE IT MORE THAN A MILE OR TWO
INLAND. WITH AFTERNOON TEMPERATURES FORECAST SOME 3 TO 5 DEG F
WARMER THAN THOSE REACHED WED AND VERY LITTLE LOW LEVEL FLOW TO
IMPEDE A FURTHER INLAND ADVANCE OF THE LAKE BREEZE DO EXPECT IT
TO REACH MDW AROUND 22Z AND MDW AROUND 23Z SHIFTING LIGHT WINDS
FROM OUT OF THE NNW AND N TO OUT OF THE ENE AND NE.
WITH SUNSET AND LOSS OF HEATING THE BOUNDARY WILL WASH OUT
LEAVING WINDS LIGHT VARIABLE OR NIL WITH THE RIDGE AXIS BASICALLY
STILL OVERHEAD AS IT IS NOT PROGGED TO REACH THE IL LAKE SHORE TIL
EARLY FRI MORNING.
SURFACE HEATING AND MARGINAL LOW LEVEL MOISTURE MAY GIVE RISE
TO FEW-SCT STRATOCU MID MORNING THROUGH EARLY AFTERNOON THEN
WARMING IN THE 850-800HPA LAYER CREATES TOO LARGE OF A DEW
POINT DEPRESSION TO SUPPORT ANY DIURNAL CLOUDS. OTHERWISE ONLY
FEW-SCT CIRRUS RIDING OVER A BROAD WESTERN UPPER RIDGE REACHING
THE LOCAL AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE LAKE BREEZE DEVELOPMENT AGAIN THIS AFTERNOON...
MEDIUM CONFIDENCE REGARDING TIMING OF ARRIVAL AT ORD AND MDW.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT AND SATURDAY...VFR.
* SATURDAY NIGHT....MVFR. RAIN LIKELY.
* SUNDAY...MVFR EARLY...THEN VFR. W-WNW WINDS GUSTING 20-25KT LATE
MORNING THROUGH AFTERNOON.
* SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR.
TRS
&&
.MARINE...
342 AM CDT
A HIGH PRESSURE RIDGE EXTENDING FROM HUDSON BAY S ACROSS THE
UPPER MIDWEST AND MID AND LOWER MS VALLEY TO THE GULF COAST HAS
BEEN MOVING VERY SLOWLY EASTWARD THE LAST FEW DAYS AND WILL
CONTINUE THIS VERY SLOW APPROACH EASTWARD TODAY...WITH THE RIDGE
AXIS FINALLY MOVING OVER LAKE MI TONIGHT. WITH THE RIDGE CLOSE BY
AND EVENTUALLY OVER THE LAKE ONLY LIGHT TO GENTLE BREEZES WILL BE
EXPERIENCED FROM MIDDAY TODAY THROUGH FRIDAY.
WITH THE RIDGE THEN MOVING FURTHER E TO THE LOWER GREAT LAKES AND
THE UPPER OH FRI NIGHT...AND LOW PRESSURE MOVING E ACROSS
NORTHERN MANITOBA TO NORTHERN ONTARIO PUSHING A COLD FRONT
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS WINDS WILL RESULT IN
S TO SW WINDS ESTABLISHING OVERNIGHT FRIDAY AND GRADUALLY
INCREASING TO FRESH SOUTH BREEZES BY SAT AFTERNOON.
THE STRONG COLD FRONT TRAILING SW FROM THE CANADIAN LOW WILL MOVE
ACROSS LAKE MI SUN AND SUN NIGHT LEADING SHIFTING WINDS TO OUT OF
THE W AND NW AND AN INCREASE TO NEAR GALE FORCE OVERNIGHT SUNDAY.
THESE NEAR GALE WINDS WINDS CONTINUE INTO MONDAY AFTERNOON. THERE
IS THE POTENTIAL FOR LOW END GALES ON THE LAKE AFTER THE COLD
FRONT PASSES INTO THE CENTRAL GREAT LAKES LATE SUN NIGHT AND MON
BUT THIS POTENTIAL LOOKS TO BE SMALL AT THIS TIME.
BEHIND THE COLD FRONT HIGH PRESSURE BUILDS FROM SASKATCHEWAN TO
THE CENTRAL PLAINS SUN AND MON. AS THE HIGH MOVES FURTHER TO THE
E ACROSS THE PLAINS NW WINDS ON LAKE MI WILL BEGIN TO GRADUALLY
DIMINISH LATE MONDAY NIGHT AND TUESDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
604 AM CDT THU MAR 28 2013
.DISCUSSION...
332 AM CDT
WHILE THE FORECAST IS GENERALLY QUIET...THERE ARE SOME CHALLENGES.
THESE CONTINUE TO BE TEMPERATURES AND WEIGHING THE EFFECTS OF THE
LAKE BREEZE FOR DOWNTOWN CHICAGO AND OTHER NEARBY
LOCATIONS...FOLLOWED BY RAIN LIKELIHOOD SATURDAY NIGHT AND THE
PATTERN BEHIND THE COLD FRONT.
WHILE THE UPPER AND MID-LEVEL WIND FLOW REMAINS NORTHWESTERLY...THE
AIR MASS IS BECOMING MORE PACIFIC ORIGIN THAN MODIFIED ARCTIC PER
UPPER AIR ANALYSES. THE HIGH PRESSURE RIDGE IS CENTERED NEAR THE
MISSISSIPPI RIVER EARLY THIS MORNING AND WILL MOVE OVER THE AREA
BY AFTERNOON AND PERSIST THROUGH LATE IN THE DAY FRIDAY. THIS
LIGHT PRESSURE GRADIENT FORCE ALONG WITH MORE SUNSHINE TOWARD
WARMING TEMPERATURES OVER LAND WILL CERTAINLY FOSTER LAKE BREEZE
DEVELOPMENT. IT IS LIKELY THIS WILL BE EARLIER THAN THE PAST TWO
DAYS GIVEN THE SETUP. THIS IS SUPPORTED BY THE HRRR WHICH STARTS
THE LAKE BREEZE NEAR 11 AM. HAVE CONTINUED TO REFLECT A DROPPING
AND THEN STABILIZING TEMPERATURE TREND NEAR THE LAKE SHORE...WITH
AFTERNOON READINGS LIKELY IN THE UPPER AND MAYBE EVEN MID 30S. AS
FOR THE REMAINDER OF THE FORECAST AREA...SOME CU IS POSSIBLE
NAMELY OVER NE IL AND NW IN AS THE LAST OF THE COLD AIR ALOFT
SCOOTS OUT. THE WARM AIR ADVECTION IN ITS PLACE AND FURTHER MIXING
SHOULD ALLOW FOR WIDESPREAD HIGHS IN THE MID 40S...BASICALLY THE
HIGHS OF YESTERDAY PLUS THREE TO FOUR DEGREES.
ANOTHER SHARP UPPER TROUGH WILL DIG INTO THE GREAT LAKES REGION BY
EARLY NEXT WEEK...WITH A FIRST SEEMINGLY WELL-DEFINED SHORT WAVE
AND SURFACE TROUGH ADVANCING THROUGH THE AREA SATURDAY NIGHT. THE
NAM...GFS...AND EC ALL AGREE ON A SURFACE LOW RESPONSE FROM
NORTHERN MO THROUGH OUR AREA DURING SATURDAY NIGHT...WITH A
FOCUSED MOIST ADVECTION AND CONVERGENCE AREA MOVING ACROSS WITHIN
FAIRLY GOOD UPPER FORCING. HAVE CONTINUED TO INCH UP POPS FOR
SATURDAY EVENING. SOME GUIDANCE INCLUDING THE EC AND NAM ALREADY
SPREAD RAIN INTO THE WESTERN AND SOUTHWESTERN FORECAST AREA AS
EARLY AS MID TO LATE AFTERNOON AND HAVE CONTINUED TO ACCOUNT FOR
THAT. MORE MEMBERS OF THE GEFS SHOW POTENTIAL FOR OVER A QUARTER
OF AN INCH BUT VERY FEW INCLUDING IN THE SREF GIVE OVER ONE HALF
AN INCH.
TEMPERATURES IN ADVANCE OF THE FRONT LOOK TO EXCEED 50 AREA-WIDE
ON SATURDAY WITH A MILD NIGHT AS THE CLOUDS AND THE BOUNDARY PASS.
SUNDAY TEMPERATURES IN THE UPPER 40S TO MID 50S ARE LOOKING MORE
CONFIDENT THANKS TO A HIGH STARTING POINT AND THE FIRST COLD FRONT
NOT BRINGING MUCH OF A COLD AIR DUMP. THAT WILL COME SUNDAY NIGHT
WITH A COOL PATTERN TO START NEXT WEEK AS 850 MB TEMPERATURES DROP
ONCE AGAIN TO ONE AND A HALF STANDARD DEVIATIONS BELOW NORMAL /PER
GEFS AND EC FORECASTS/. HAVE ADAPTED LOCAL CLIMATOLOGICAL RESEARCH
FOR THESE 850MB TEMPERATURES OF -10C INTO THE FORECAST...WHICH
INDICATE GOOD POTENTIAL FOR HIGHS TO REMAIN AT OR BELOW 40 IN
CHICAGO...WHICH ALREADY LOOKED PRETTY GOOD IN THE FORECAST. ONE
THING ABOUT NEXT WEEK COMPARED TO THE COOL TEMPERATURES OF EARLIER
THIS WEEK IS THAT WHILE UNDER CYCLONIC FLOW AGAIN WE WILL BE LESS
ENTRENCHED AND THUS LESS FAVORED FOR CONTINUOUS STARTOCU. WE
SHOULD HAVE SOME DURING THE DAYS BUT WE ARE FURTHER FROM THE
CYCLONIC CENTER WHICH WILL BE UP IN QUEBEC ALREADY BY MONDAY
AFTERNOON. NO SIGN OF A MAJOR WARM-UP BUT A GRADUAL ONE LATE NEXT
WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LAKE BREEZE DEVELOPMENT DURING THU AND HOW FAR INLAND IT
REACHES DURING BY EVENING.
TRS
//DISCUSSION...UPDATED 06Z...
A RIDGE OF HIGH PRESSURE CURRENTLY EXTENDS FROM WESTERN HUDSON
BAY SOUTH ACROSS THE UPPER MIDWEST AND MID AND LOWER MS VALLEY TO
THE GULF OF MEX LATE TONIGHT. THIS RIDGE HAS BEEN MOVING VERY
SLOWLY E FROM THE PLAINS TOWARD THE LOCAL AREA OVER THE LAST FEW
DAYS. WITH ITS CONTINUED GRADUAL DRIFT TO THE E THE RIDGE AXIS IS
FINALLY PROGGED TO MOVE OVER THE LOCAL AREA DURING THIS AFTERNOON
AND EVENING.
WITH THE RIDGE AXIS VERY NEAR OR OVERHEAD THIS AFTERNOON AND
EVENING THE CURRENT LIGHT NW TO NNW LOW LEVEL FLOW WILL WEAKEN
EVEN FURTHER AND BASICALLY BE NIL BY 00Z. WHILE A VERY WEAK LAKE
BREEZE DID DEVELOP WED IT DID NOT MAKE MORE THAN A MILE OR TWO
INLAND. WITH AFTERNOON TEMPERATURES FORECAST SOME 3 TO 5 DEG F
WARMER THAN THOSE REACHED WED AND VERY LITTLE LOW LEVEL FLOW TO
IMPEDE A FURTHER INLAND ADVANCE OF THE LAKE BREEZE DO EXPECT IT
TO REACH MDW AROUND 22Z AND MDW AROUND 23Z SHIFTING LIGHT WINDS
FROM OUT OF THE NNW AND N TO OUT OF THE ENE AND NE.
WITH SUNSET AND LOSS OF HEATING THE BOUNDARY WILL WASH OUT
LEAVING WINDS LIGHT VARIABLE OR NIL AS THE RIDGE AXIS WILL BE
OVERHEAD THROUGH THE NIGHT AS IT IS NOT PROGGED TO REACH THE IL
LAKE SHORE TIL EARLY FRI MORNING.
SURFACE HEATING AND MARGINAL LOW LEVEL MOISTURE MAY GIVE RISE
TO FEW-SCT STRATOCU MID MORNING THROUGH EARLY AFTERNOON THEN
WARMING IN THE 850-800HPA LAYER CREATES TOO LARGE OF A DEW
POINT DEPRESSION TO SUPPORT AND STRATOCU DURING THE LATER THIS
AFTERNOON. OTHERWISE ONLY FEW-SCT CIRRUS RIDING OVER A BROAD
WESTERN UPPER RIDGE REACHING THE LOCAL AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE LAKE BREEZE DEVELOPMENT AGAIN THU AFTERNOON...
MEDIUM CONFIDENCE REGARDING TIMING AT ORD/MDW.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...DRY. VFR. AFTERNOON LAKE BREEZE.
* SATURDAY...DRY/VFR DURING THE DAY THEN MVFR WITH RAIN LIKELY
SATURDAY NIGHT.
* SUNDAY...CHANCE OF RAIN. MVFR POSSIBLE.
* MONDAY AND TUESDAY...DRY. VFR.
&&
.MARINE...
342 AM CDT
A HIGH PRESSURE RIDGE EXTENDING FROM HUDSON BAY S ACROSS THE
UPPER MIDWEST AND MID AND LOWER MS VALLEY TO THE GULF COAST HAS
BEEN MOVING VERY SLOWLY EASTWARD THE LAST FEW DAYS AND WILL
CONTINUE THIS VERY SLOW APPROACH EASTWARD TODAY...WITH THE RIDGE
AXIS FINALLY MOVING OVER LAKE MI TONIGHT. WITH THE RIDGE CLOSE BY
AND EVENTUALLY OVER THE LAKE ONLY LIGHT TO GENTLE BREEZES WILL BE
EXPERIENCED FROM MIDDAY TODAY THROUGH FRIDAY.
WITH THE RIDGE THEN MOVING FURTHER E TO THE LOWER GREAT LAKES AND
THE UPPER OH FRI NIGHT...AND LOW PRESSURE MOVING E ACROSS
NORTHERN MANITOBA TO NORTHERN ONTARIO PUSHING A COLD FRONT
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS WINDS WILL RESULT IN
S TO SW WINDS ESTABLISHING OVERNIGHT FRIDAY AND GRADUALLY
INCREASING TO FRESH SOUTH BREEZES BY SAT AFTERNOON.
THE STRONG COLD FRONT TRAILING SW FROM THE CANADIAN LOW WILL MOVE
ACROSS LAKE MI SUN AND SUN NIGHT LEADING SHIFTING WINDS TO OUT OF
THE W AND NW AND AN INCREASE TO NEAR GALE FORCE OVERNIGHT SUNDAY.
THESE NEAR GALE WINDS WINDS CONTINUE INTO MONDAY AFTERNOON. THERE
IS THE POTENTIAL FOR LOW END GALES ON THE LAKE AFTER THE COLD
FRONT PASSES INTO THE CENTRAL GREAT LAKES LATE SUN NIGHT AND MON
BUT THIS POTENTIAL LOOKS TO BE SMALL AT THIS TIME.
BEHIND THE COLD FRONT HIGH PRESSURE BUILDS FROM SASKATCHEWAN TO
THE CENTRAL PLAINS SUN AND MON. AS THE HIGH MOVES FURTHER TO THE
E ACROSS THE PLAINS NW WINDS ON LAKE MI WILL BEGIN TO GRADUALLY
DIMINISH LATE MONDAY NIGHT AND TUESDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
634 AM CDT THU MAR 28 2013
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1030 PM CDT WED MAR 27 2013
THE 28.00Z 250 HPA RAOB MAP SHOWED WESTERLY TO NORTHWESTERLY FLOW ACROSS
MUCH OF THE COUNTRY. WIND MAGNITUDES WERE ~50 KT OVER THE PACIFIC NORTHWEST,
~85 KT ACROSS THE KDDC REGION, AND THE STRONGEST WAS ~125+ KT ACROSS
FLORIDA. AT 500 HPA, A DRY NORTHWESTERLY FLOW WAS OBSERVED ACROSS THE
GREAT PLAINS. TEMPERATURES VARIED FROM -10 DEG C AT KBRO TO -24 DEG
C AT KBIS. THE MID LEVEL COLD POOL WITH TEMPERATURES IN THE -30 DEG
C TO -33 DEG C RANGE WAS WELL TO THE NORTHEAST OF SOUTHWEST KANSAS.
AT 700 HPA, THERE WAS A WEAK BAROCLINIC BOUNDARY BETWEEN KDDC (-1 DEG
C) AND KAMA (4 DEG C). AT 850 HPA, A TEMPERATURE GRADIENT CONTINUED
FROM KDDC (7 DEG C) TO KAMA (16 DEG C). SOME LOW LEVEL MOISTURE ADVECTION
WAS NOTED ACROSS FAR SOUTH TEXAS. AT THE SFC, A STATIONARY FRONT WAS
ANALYZED ACROSS THE NORTHERN HIGH PLAINS. THIS BOUNDARY TURNED INTO
A COLD FRONT ACROSS THE SOUTHERN HIGH PLAINS. RELATIVELY HIGHER DEWPOINTS
OF 50+ DEG F WERE CONFINED TO COASTAL SOUTH TEXAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CDT THU MAR 28 2013
THIS MORNING:
IMMEDIATE SHORT TERM CONCERN IS PATCHY FOG ACROSS CENTRAL KANSAS THIS
MORNING. A NORTHEASTERLY UPSLOPE FLOW ALONG WITH SURFACE PRESSURE CONDENSATION
DEFICITS NEAR 0 HPA AND IN COMBINATION WITH BUFR/BUFKIT FORECAST SOUNDING
SPELL THE CONCERN FOR PATCHY FOG NORTHEAST OF A LINE FROM ST. JOHN TO
PENDENNIS. HRRR IS QUITE AGGRESSIVE WITH THE FOG AND SUGGESTING DENSE
FOG (LESS THAN/EQUAL TO QUARTER OF A MILE VISIBILITY) BUT FEEL THIS
MIGHT BE OVERDONE.
TODAY:
A WEAK WARM AIR ADVECTION PATTERN IS EXPECTED TODAY AS A RESULT OF 500
HPA GEOPOTENTIAL HEIGHT INCREASES AND WITH WINDS BECOMING EAST-SOUTHEASTERLY
TONIGHT AS WEAK LEE SURFACE TROUGHING DEEPENS ACROSS COLORADO. FORECAST
SOUNDINGS SHOW A MIXED PROFILE GENERALLY UP TO 750 HPA, WHICH SUPPORTS
MIX DOWN TEMPERATURES IN THE 60S DEG F. PLENTY OF MID TO HIGH LEVEL
CLOUDS IS EXPECTED TODAY AS WATER VAPOR IMAGERY SHOWS MOISTURE ADVECTION
FROM THE ROCKIES AND EVENTUALLY OUT ACROSS THE CENTRAL PLAINS. DELETERIOUS
TEMPERATURE IMPACTS ARE NOT EXPECTED FROM THE AFOREMENTIONED CLOUDS.
TONIGHT:
HAVE A SLIGHT CONCERN FOR OVERNIGHT SHOWERS ACROSS SOUTH CENTRAL KANSAS
IN ASSOCIATION WITH CONTINUED WARM AIR ADVECTION AND WEAK LIFT ALONG
A STATIONARY FRONT. 0-10 KM MUCAPE (DONE TO CAPTURE THE ENTIRE ATMOSPHERIC
COLUMN) FROM THE NAM SHOWS VALUES AROUND 500-700 J/KG ACROSS THIS REGION,
SO CANNOT RULE OUT ISOLATED THUNDER. THE BEST THETA-E ADVECTION IS SOUTH
AND EAST OF THE REGION, SO WILL NOT GET CARRIED AWAY WITH PRECIPITATION
PROBABILITIES OTHER THAN THE SLIGHT CATEGORY. OVERNIGHT LOWS WILL BE
WARMER - 40S DEG F - AS A RESULT OF CLOUD COVER, SOUTHERLY WINDS, AND
SLIGHTLY HIGHER DEWPOINTS (PARTICULARLY ACROSS SC KS).
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 402 AM CDT THU MAR 28 2013
WEST NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE CENTRAL HIGH
PLAINS. LOW LEVEL MOISTURE OVER THE SOUTHERN PLAINS WILL BE
ADVECTING NORTHWARD INTO KANSAS THROUGH THE NEXT FEW DAYS. A FRONTAL
BOUNDARY IS PROGGED TO REMAIN NEARLY STATIONARY ACROSS OKLAHOMA AND
THE TEXAS PANHANDLE INTO EASTERN COLORADO. THE LOW LEVEL MOISTURE
WILL RESULT IN INCREASING LOW CLOUDINESS TO SOUTHWEST KANSAS FRIDAY
INTO FRIDAY NIGHT. MODEL SOUNDINGS SHOW INCREASING MID LEVEL
INSTABILITY AS WELL. SOME MID LEVEL WARM ADVECTION COULD SPAWN A FEW
SHOWERS AND THUNDERSTORMS ON FRIDAY. THUNDERSTORMS COULD ALSO
DEVELOP OVER EASTERN COLORADO FRIDAY AFTERNOON AND MOVE INTO FAR
WESTERN KANSAS LATER IN THE DAY. A SHORTWAVE TROUGH MOVING INTO THE
UPPER MIDWEST WILL PUSH ANOTHER COLD FRONT SOUTH ACROSS WESTERN
KANSAS ON SATURDAY. THIS COULD TRIGGER THUNDERSTORMS AGAIN SATURDAY
AFTERNOON. THERE IS SOME POTENTIAL FOR SEVERE THUNDERSTORMS OVER
SOUTH CENTRAL KANSAS AS CAPE AND SHEAR VALUES INCREASE TO AROUND
1000 J/KG AND 30-40 KNOTS, RESPECTIVELY. DRIER CONDITIONS SHOULD
PREVAIL ON SUNDAY BEHIND THE FRONT.
THE MEDIUM RANGE MODELS CONTINUE TO SHOW A STRONG UPPER LEVEL LOW
PRESSURE SYSTEM DIGGING SOUTH OUT OF CANADA INTO THE GREAT LAKES
REGION WITH NEARLY MERIDIONAL FLOW DEVELOPING OVER THE NORTHERN
PLAINS. THIS WILL PUSH A STRONG COLD FRONT SOUTH ACROSS THE CENTRAL
PLAINS SUNDAY NIGHT WITH MUCH COLDER TEMPERATURES WILL BE PUSHING
SOUTH BEHIND THE FRONT. THERE WILL BE CHANCES FOR SHOWERS AND
ISOLATED THUNDERSTORMS WITH THE FRONT. THE RAIN SHOULD MIX WITH OR
CHANGE OVER TO LIGHT SNOW LATE SUNDAY NIGHT INTO MONDAY AS THE
COLDER AIR MOVES IN. HAVE LOWERED HIGH TEMPERATURES ON MONDAY INTO
THE 30S WITH LOW 40S ALONG THE OKLAHOMA BORDER. HIGHS ON TUESDAY
WILL CONTINUE TO BE ON THE COOL SIDE...STAYING MAINLY IN THE 40S.
WARMER WEATHER WILL RETURN TO THE CENTRAL PLAINS BY MID WEEK AS
TEMPERATURES CLIMB BACK INTO THE 50S AND 60S BY WEDNESDAY AND
THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 634 AM CDT THU MAR 28 2013
WITH ONLY SCATTERED HIGH CLOUDINESS EXPECTED TO STREAM ACROSS THE
CENTRAL HIGH PLAINS TODAY...VFR CONDITIONS ARE EXPECTED TO PREVAIL
THROUGH THIS EVENING. LOW LEVEL MOISTURE MOVING UP FROM THE
SOUTHERN PLAINS TODAY AND TONIGHT WILL BRING INCREASING CHANCES
FOR AT MVFR/IFR CIGS AND VSBYS TOWARD THE END OF THIS TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 43 65 48 / 10 10 30 20
GCK 64 41 65 46 / 10 10 20 20
EHA 64 42 68 46 / 10 10 20 20
LBL 64 44 67 48 / 10 10 20 20
HYS 62 39 64 47 / 10 10 20 20
P28 65 47 63 51 / 10 20 40 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...GERARD
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1045 AM CDT THU MAR 28 2013
.UPDATE...
ISSUED AT 1024 AM CDT THU MAR 28 2013
NOT MUCH CHANGE IS NEEDED TO GOING FORECAST. HAVE CONFINED SPRINKLES
TO THE FAR SOUTHWEST PART OF THE CWA THROUGH MID AFTERNOON...CLOSE
TO WHERE THERE IS A DIMINISHING BAND OF -SHRA OVER SOUTH CENTRAL
MO. KEPT GOING FORECAST FOR ISOLATED -SHRA OVER THE SOUTHERN CWA
LATE THIS AFTERNOON WHERE RAP IS SHOWING SOME MODEST 925-850MB
MOISTURE CONVERGENCE. STILL EXPECT THE COVERAGE OF -SHRA TO
INCREASE TONIGHT AS LOW LEVEL MOISTURE CONVERGENCE INCREASES UNDER
MODEST ASCENT ASSOCIATED WITH WEAK MID LEVEL VORT MOVING
SOUTHEASTWARD ACROSS THE AREA. DID INCREASE TEMPERATURES A BIT IN
THE FAR NORTHWESTERN CWA WHERE THERE IS SOME MORE SUNSHINE WITH
LITTLE SNOW COVER.
BRITT
&&
.SHORT TERM...(THROUGH LATE THIS AFTERNOON)
ISSUED AT 425 AM CDT THU MAR 28 2013
WEAK BUT PERSISTENT WAA SHOULD ALLOW CLOUDS TO PERSIST OVER MUCH OF
THE CWA TODAY...ALTHOUGH DO EXPECT SOME DIURNALLY DRIVEN
BREAKS/THINNING DURING THE LATE MORNING AND AFTERNOON. THIS WAA
DRIVEN ASCENT IS SHOWING UP NICELY ON THE 290 AND 295 THETA SURFACES
FROM THE 00Z RUNS. RADAR DATA DOES INDICATE SOME WEAK RETURNS TO
THE W/SW OF THE LSX 88D EARLY TODAY...AND HAVE CARRIED A FEW
SPRINKLES WITH THIS WEEPING AC INTO MID MORNING. HAVE ALSO
INTRODUCED SOME SLIGHT CHANCE POPS OVER S SECTIONS OF THE CWA BY
LATE THIS AFTERNOON AS THE WAA APPEARS TO BEGIN TO INTENSIFY BY THIS
TIME...BUT CERTAINLY THE MAIN PRECIP THREAT SHOULD BE LATER TONIGHT.
MEANWHILE...AND MUCH LIKE YESTERDAY...DRIER AIR ASSOCIATED WITH
SLOWLY RETREATING SURFACE HIGH WILL TEND TO KEEP THE CLOUDS AT BAY
OVER NE SECTIONS OF THE CWA.
TEMPERATURES WILL BE A TOUGH CALL...WITH VARIABLE SKY
CONDITIONS...RECEDING SNOW COVER...A SLOWLY MODERATING AIRMASS...AND
A SURFACE WARM FRONT THAT 2M TEMPS FROM THE HI-RES MODELS SUGGEST
MAY REACH OUR FAR S COUNTIES. UNDER THE CLOUD COVER IN MID MO HAVE
LEANED TOWARDS CONDITIONAL CLIMATOLOGY...WHICH WOULD SUGGEST ABOUT A
15 DEGREE CLIMB FROM MORNING LOWS...WHILE IN OUR FAR S HAVE ALLOWED
TEMPS TO PUSH THE 60 DEGREE MARK. FINALLY...IN THE MORE SUNNY AREAS
IN OUR NE COUNTIES...HAVE RAISED MAX TEMPS ABOUT ONE CAT FROM
YESTERDAYS HIGHS.
TRUETT
&&
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 425 AM CDT THU MAR 28 2013
MODELS HAVE BEEN CONSISTENTLY SHOWING AN INCREASE IN MOISTURE RETURN
FOR TONIGHT. THERE ARE A COUPLE OF WEAK SIGNALS FOR PCPN INCLUDING A
WEAK SHORTWAVE THAT WILL BE APPROACHING THE AREA WITHIN NW FLOW
ALOFT...AN AREA OF MODERATE ISENTROPIC ASCENT ALONG THE 290K SFC AS
DEPICTED BY THE ECMWF/GFS/GEM...AND WEAK H85 MCONV ALONG THE NOSE OF
A SWLY LLJ. CHC POPS FOR SHRA/TSRA LOOK REASONABLE IN THE ABSENCE OF
ANY SINGLE STRONG SIGNAL FOR PCPN OTHER THAN MOISTURE RETURN. PDS OF
ISO-SCT PCPN MAY CONTINUE THROUGH FRI NIGHT INVOF A DVLPG BAROCLINIC
ZONE IN SRN MO UNTIL THE BDRY LIFTS NEWD ON SAT.
TWO CDFNTS ARE STILL EXPECTED TO MOVE ACROSS MO/IL THIS WEEKEND
HOWEVER RECENT MODELS RUNS HAVE BEEN MUCH QUICKER WITH FROPA TIMING
THAN THEY WERE 24 HR AGO. IT NOW APPEARS THAT THE FIRST CDFNT WILL
MOVE THROUGH THE CWA ON SAT NIGHT. MODELS CONTINUE TO SHOW A FEW
HUNDRED J/KG OF MUCAPE ON SAT NIGHT THEREFORE THERE MAY BE SOME
EMBEDDED THUNDERSTORMS ALONG WITH THE RAIN SHOWERS. A VORT LOBE WILL
DRIVE THE SECONDARY CDFNT THROUGH MO/IL ON SUNDAY NIGHT AND EARLY
MONDAY MORNING...BRINGING A REINFORCING SHOT OF COLD AIR TO THE AREA
WHILE A 1030MB SFC HIGH BUILDS SEWD OUT OF CANADA. WITH A MUCH
COLDER AIR MASS IN PLACE ACROSS THE REGION...THE NEXT ROUND OF PCPN
COULD FALL AS A RAIN/SNOW MIX WHEN ANOTHER VORT LOBE MOVES ACROSS
THE AREA ON MON NIGHT AND TUE. GFS/ECMWF REMAIN IN POOR AGREEMENT
REGARDING FEATURES WITHIN THE LARGE SCALE PATTN AFTER 00Z TUE
HOWEVER BOTH MODELS DO SHOW A POTENTIAL SRN STREAM SYSTEM FOR
SOMETIME DURING THE MIDDLE OR LATE PART OF THE WEEK. TEMPERATURES
REMAIN BELOW NORMAL THROUGH THE EXTENDED FCST PD.
KANOFSKY
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 705 AM CDT THU MAR 28 2013
RATHER WEAK BUT PERSISTENT WAA SHOULD KEEP MID CLOUD DECK LOCKED
OVER THE REGION TODAY...WITH VFR CIGS AOA 5KFT. INCREASE OF
MOISTURE ADVECTION INTO AREA TONIGHT ALONG WITH APPROACH OF
SHORTWAVE IN NW FLOW SHOULD PRODUCE SHOWERS...WITH THE GREATEST
COVERAGE ALONG AND ESPECIALLY SOUTH OF THE I-70 CORRIDOR. WITH
SURFACE WARM FRONT BECOMING ESTABLISHED OVER S MO...WOULD THINK
THAT CIGS AND VSBYS WILL ALSO BE DROPPING INTO AT LEAST THE MVFR
CAT AFTER 06Z.
SPECIFICS FOR KSTL...CIGS AOA 5KFT WILL BE COMMON THROUGHOUT THE
DAY AND INTO THE EARLY EVENING HOURS. CIGS SHOULD SLOWLY LOWER
AFTER 00Z WITH THE AFOREMENTIONED INCREASE OF MOISTURE AND
LIFT...WITH A FEW SHOWERS THREATENING THE AREA BEGINNING AROUND
MIDNIGHT. ALSO EXPECT A FAIRLY RAPID DROP IN CIGS AND VSBYS INTO
AT LEAST THE THE MVFR CAT DURING THE PREDAWN HOURS.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
927 AM MDT THU MAR 28 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...
MORNING UPDATE...
SHOWERS WILL KICK OFF LATE TODAY ACROSS THE CENTRAL MONTANA
MOUNTAINS. A SMALL CHANCE EXISTS FOR EMBEDDED THUNDER TO MAKE IT
AS FAR EAST AS THE LITTLE ROCKIES BEFORE DYING AND TRANSITIONING
OVER TO TOTAL RAIN SHOWERS BY THE LATE EVENING HOURS. NAM FORECAST
SOUNDINGS HAVE 400J/KG OF CAPE OVER LEWISTOWN BUT DRAMATICALLY
TAPER IT DOWN TO 100J/KG OR LESS ACROSS JORDAN...AND ELEVATE IT TO
BOOT. HRRR RUNS ALSO SHOW QPF EXITING THE DOWNSLOPE AND BECOMING
LESS INTENSE DURING THE AFTERNOON/EVENING TRANSITION. THIS SEEMS
TO SUPPORT THE OVERALL IDEA. ASIDE FROM THIS... SKEWED WIND FIELDS TO
CURRENT MESOSCALE MODELS. GAH
PREVIOUS SHORT TERM DISCUSSION...
A LONG-WAVE TROUGH OVER EASTERN CONUS AND AN UPPER RIDGE TO THE
WEST WILL MAINTAIN NORTHWEST FLOW ALOFT ACROSS NORTHEAST MONTANA
THROUGH THE SHORT TERM PERIOD. THE MAIN DETERMINING FACTOR FOR
TEMPERATURES AND PRECIPITATION WILL BE THE LOCATION OF THE DIFFUSE
STATIONARY BOUNDARY.
TODAY THAT BOUNDARY WILL SEE OVERRUNNING MOISTURE THAT WILL
RESULT IN CLOUD COVER...BUT NOT MUCH IN THE WAY OF PRECIPITATION.
THAT BOUNDARY WILL FLUCTUATE THROUGH FRIDAY. HOWEVER LATE TONIGHT
AND FRIDAY A WEAK EMBEDDED DISTURBANCE IN THE FLOW ALOFT WITH ADD
JUST ENOUGH ENERGY TO POSSIBLY KICK OFF A FEW SHOWERS. THEN A
POLAR VORTEX DROPPING RAPIDLY SOUTH FROM NORTHERN CANADA WILL FIRM
UP THE BOUNDARY AS A COLD FRONT...PUSHING SOUTH INTO MONTANA LATE
FRIDAY AND SATURDAY. THIS SHARPER BOUNDARY SETTLES SOUTH OF NEMONT
BUT COULD CLIP THE SOUTHWEST ZONES WITH A BANDS OF PRECIPITATION.
TEMPERATURE THROUGH THE SHORT TERM WILL CONTINUE TO NUDGE UPWARD
AS THE SNOW-PACK MELTS. THE VISUAL GOES IMAGERY TODAY REVEALED
THE EDGE OF THE SNOW-PACK TO STRETCH FROM NORTHERN PHILLIPS COUNTY
TO RICHLAND COUNTY. ALL LOCATIONS NORTHEAST OF THAT LINE REMAINS
UNDER SNOW-PACK. THIS WILL CONTINUE TO INSURE A WIDE SPREAD OF
TEMPERATURES FROM THE NORTHEAST COUNTIES TO THE SOUTHWEST
COUNTIES. WITH THE BOUNDARY IN GENERAL STRETCHING FROM THE
NORTHWEST TO THE SOUTHEAST AREA OF THE CWA...TEMPERATURES WILL
CONTINUE SLIGHTLY BELOW NORMAL...THUS ENSURING CONTINUED SNOW
MELT. SO FAR THE RIVERS ARE HANDLING THE RUNOFF.
WITH ANOTHER RATHER WARM AND MOSTLY SUNNY DAY ON WEDNESDAY...THE
BOUNDARY LAYER HAS ADDED HUMIDITY. THEREFORE PATCHY FREEZING FOG
WILL CONTINUE TO AFFECT AREAS WHERE THERE IS STILL SNOW-PACK.
ADDED AREAS OF DENSE FOG IN SHERIDAN AND EASTERN ROOSEVELT
COUNTIES. SCT
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
COLDER AIRMASS MOVES SOUTH INTO EASTERN MONTANA SATURDAY NIGHT AND
SUNDAY AS POLAR VORTEX UPPER LOW DIVES SOUTH TOWARDS THE WESTERN
GREAT LAKES. BOTH THE GFS AND ECMWF AGREE ON SOME OVERRUNNING
MOISTURE NORTHEAST OF THE FRONTAL BOUNDARY ON SUNDAY MAINLY IN THE
SOUTHWEST PART OF THE FORECAST AREA. WILL MENTION A CHANCE OF SNOW
FOR NOW.
ARCTIC HIGH PRESSURE BUILDS INTO THE AREA SUNDAY NIGHT AND MONDAY
WITH CLEAR TO PARTLY CLOUDY SKIES AND WINTER-LIKE TEMPERATURES.
NORTHWEST FLOW ALOFT WILL CONTINUE TUESDAY AND WEDNESDAY.
MEANWHILE...THE POLAR VORTEX MOVES TO THE EAST AND UPPER RIDGE
MOVES INLAND FROM THE PACIFIC WHILE WILL ALLOW FOR A WARMING TREND
OVER NORTHEAST MONTANA. LINGERING SNOW OVER THE NORTHEAST HALF OF
THE REGION WILL LIMIT WARMING THERE.
MODELS DIFFER ON TIMING OF COLD FRONT FOR THE MIDDLE OF NEXT WEEK.
GFS BRINGS THE FRONT SOUTH ON WEDNESDAY WHILE THE ECWMF WAITS
UNTIL THURSDAY. WILL MENTION A SLIGHT CHANCE OF RAIN OR SNOW
SHOWERS IN SOME AREAS FOR NOW. FORRESTER
&&
.AVIATION...
PATCHY FOG IN THE GLENDIVE AND SIDNEY AREAS SHOULD BURN OFF BY
NOON IF NOT EARLIER. FOLLOWING FOG BURN OFF...ALL SITES SHOULD SEE
VFR CONDITIONS WITH SCATTERED TO BROKEN MID AND HIGH LEVEL CLOUDS
TODAY AND TONIGHT WITH LIGHT MAINLY EASTERLY WINDS. A WEAK UPPER
LEVEL DISTURBANCE COULD BRING SOME WIDELY SCATTERED SHOWERS FRIDAY
MORNING. MARTIN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
610 AM CDT THU MAR 28 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CDT THU MAR 28 2013
PRIMARY FORECAST LIES WITH TEMPERATURES AND FOG POTENTIAL.
QUIET CONDITIONS IN PLACE EARLY THIS MORNING...WITH UPPER AIR
PROFILER AND SATELLITE DATA SHOWING SLIGHT NORTHWESTERLY FLOW SET
UP OVER THE REGION...AS WEAK RIDGING SITS OVER THE ROCKIES AND
LOW PRESSURE/TROUGHING AFFECTS THE NORTHEASTERN CONUS. OUTSIDE OF
SOME MID/UPPER LEVEL CLOUDS GRADUALLY CREEPING EAST FROM THE HIGH
PLAINS AND ROCKIES...SKIES ACROSS THE CWA ARE CLEAR. THE SURFACE
PATTERN OVER THE CENTRAL PLAINS REMAINS WEAK...WITH HIGH PRESSURE
EXTENDING FROM ONTARIO TO THE GULF COAST...WHILE A STATIONARY
BOUNDARY LIES ALONG THE FRONT RANGE OF THE ROCKIES...RESULTING IN
CONTINUED LIGHT AND VARIABLE WINDS ACROSS THE CWA. REALLY HASNT
BEEN AT ANY HINTS OF FOG DEVELOPMENT YET THIS MORNING...BUT SOME
THE HRRR ESP CONTINUES TO SHOW THE POTENTIAL CLOSER TO
SUNRISE...SO WILL CONTINUE TO KEEP THE PATCHY MENTION GOING IN THE
FORECAST FOR THIS MORNING.
LOOKING AT THE REST OF THE SHORT TERM FORECAST...IT REMAINS A DRY
ONE WITH NO NOTABLE CHANGES OVERALL IN THE UPPER LEVEL PATTERN.
SRN PORTIONS OF THE CWA WONT BE TOO TERRIBLY FAR AWAY FROM
PRECIPITATION FORECAST OVER CENTRAL KS OVERNIGHT TONIGHT ALONG A
SFC WARM FRONT AS AN UPPER LEVEL DISTURBANCE PASSES THROUGH...ALSO
AIDED BY AN INCREASE LLJ. AT THE SURFACE...AGAIN NOT EXPECTING ANY
SIGNIFICANT CHANGES...REMAINING FAIRLY WEAK AND KEEPING WINDS
GENERALLY E/SERLY. SHOULD SEE A BUMP UP IN SPEEDS DURING THE
DAYTIME HOURS TODAY INTO THE 10 TO 15 MPH RANGE...BUT WILL LIKELY
DIE OFF AGAIN THIS EVENING/OVERNIGHT WITH A BOUNDARY LOOKING TO
SET UP OVER THE CWA. THIS IS AGAIN SOME CONCERN FOR SOME FOG
TONIGHT...WITH THE LIGHT WINDS RETURNING...BUT CONFIDENCE IS NOT
HIGH IN ITS OCCURRENCE...SO KEPT IT ONLY A PATCHY MENTION.
DEPENDING ON HOW THE REST OF THIS MORNING GOES AND WITH 12Z
MODELS...DAY SHIFT MAY BE ABLE TO REMOVE IT FROM THE FORECAST.
AS FAR AS TEMPERATURES GO...SOME GUIDANCE AND MODELS THE LAST
COUPLE OF DAYS HAVE REALLY UNDERDONE HIGHS...AND AM CONCERNED IT
MAY HAPPEN AGAIN TODAY...THOUGH MAYBE NOT QUITE TO THE EXTENT OF
PREVIOUS DAYS. STICKING CLOSER TO THE NAM/MET/ECMWF FOR TODAYS
HIGHS...YESTERDAY HAD LITTLE PROBLEM GETTING INTO THE MID
50S...AND WITH A GENERALLY SIMILAR SET UP TODAY BUT A SLIGHT
INCREASE IN TEMPS ALOFT...FELT THAT UPPER 50S/LOWER 60S WAS
REASONABLE. MAY BE A FEW MORE CLOUDS AROUND TODAY...AND AT THIS
POINT DONT FEEL IT WILL HOLD BACK TEMPS SIGNIFICANTLY...BUT IT
WILL BE SOMETHING FOR THE DAY SHIFT TO KEEP A CLOSE EYE ON.
OVERNIGHT LOWS TONIGHT LOOK TO COOL INTO THE MID 30S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 409 AM CDT THU MAR 28 2013
GUIDANCE SUGGESTS THE LONG TERM FORECAST PERIOD WILL BE DOMINATED
BY NORTHWESTERLY MID AND UPPER LEVEL FLOW. CHANCES FOR
PRECIPITATION ARE SPRINKLED THROUGHOUT THE LONG TERM FORECAST
PERIOD...THE FIRST OF WHICH PRESENTS ITSELF LATE FRIDAY AFTERNOON.
AN OVERALL LACK IN KINEMATIC FORCING WOULD OTHERWISE PRESENT DRY
CONDITIONS TO THE AREA ON FRIDAY...HOWEVER FORECAST PROXIMITY
SOUNDINGS...PER THE NAM AND OPERATIONAL GFS...SUGGEST WESTERN
PORTIONS OF OUR CWA...PRIMARILY WEST OF HIGHWAY 183...WILL REACH A
CONVECTIVE TEMPERATURE IN THE LOWER 60S. SHOULD CONVECTIVE
INITIATION BE REALIZED LATE FRIDAY AFTERNOON...THESE SAME
PROXIMITY SOUNDINGS SUGGEST 200-500J/KG SBCAPE WILL BE READY FOR
UPDRAFT PRODUCTION. FARTHER EAST ACROSS OUR CWA IT APPEARS A LOW
LEVEL CAPPING INVERSION WILL KEEP CONVECTION AT BAY...BUT GIVEN
THE THREAT FOR CONVECTION FARTHER WEST...OPTED TO KEEP THE SLIGHT
CHANCE POPS INHERITED FROM THE PREVIOUS FORECAST. GIVEN THE
AFOREMENTIONED INSTABILITY AND THE FAIRLY LOW FREEZING
HEIGHTS...WILL GO AHEAD AND CONTINUE HIGHLIGHTING SMALL HAIL IN
THE HWO FOR FRIDAY AFTERNOON.
SURFACE-BASED CONVECTION ACROSS OUR WEST FRIDAY AFTERNOON...SHOULD
IT BE REALIZED...WILL QUICKLY DISSIPATE TOWARDS SUNSET AS
DIABATIC HEATING IS LOST ACROSS THE AREA. THAT BEING
SAID...ADDITIONAL PRECIPITATION WILL BE POSSIBLE ACROSS MOST ALL
OF OUR CWA FRIDAY NIGHT INTO EARLY SATURDAY MORNING AS THE AXIS OF
A 25-30KT LOW LEVEL JET STREAK SETS UP ACROSS THE AREA. AT THIS
TIME IS APPEARS THE NOSE OF THIS LOW LEVEL JET STREAK WILL BE
REALIZED ACROSS NORTHEASTERN NEBRASKA INTO PORTIONS OF SOUTH
DAKOTA. WITH THE RESULTANT AREA OF LOW LEVEL CONVERGENCE ALSO
EXPECTED TO RESIDE NORTH OF OUR AREA...QPF FIELDS FROM MOST MODELS
KEEP THE HEAVIEST PRECIPITATION ON FRIDAY NIGHT TO OUR
NORTH/NORTHEAST. THAT BEING SAID IT STILL APPEARS THERE WILL BE
ENOUGH LOW LEVEL THERMAL ADVECTION ALONG THE LOW LEVEL JET AXIS
FOR PRECIPITATION PRODUCTION ACROSS MOST ALL OF OUR CWA. WENT
AHEAD WITH 30%-50% POPS ACROSS OUR NORTH/NORTHEAST FRIDAY
NIGHT/SATURDAY MORNING...CLOSER TO THE NOSE OF THE LOW LEVEL
JET...WITH POPS CLOSER TO 20% FARTHER SOUTH/SOUTHWEST ACROSS OUR
CWA.
THERE MAY BE SOME LINGERING CONVECTION ALONG THE LOW LEVEL JET
AXIS AROUND OR JUST AFTER SUNRISE SATURDAY...HOWEVER THIS
ACTIVITY SHOULD WANE AS THE LOW LEVEL JET DECREASES IN INTENSITY.
WENT AHEAD AND KEPT 20%-30% POPS GOING ACROSS MUCH OF OUR CWA 12Z-
18Z SATURDAY AS A RESULT. THE PASSAGE OF A SUBTLE MID LEVEL SHORT
WAVE ACROSS THE NORTHERN PLAINS IS EXPECTED TO HELP PUSH A LOW
LEVEL BAROCLINIC ZONE ACROSS OUR AREA DURING THE DAY SATURDAY AND
WHILE MUCH OF OUR AREA SHOULD BE DRY ON SATURDAY FOLLOWING THE
DISSIPATION OF MORNING CONVECTION...THERE IS SOME CONCERN THAT
THERE COULD BE ADDITIONAL AFTERNOON CONVECTION ALONG THE LOW LEVEL
BAROCLINIC ZONE ACROSS OUR SOUTH. GIVEN THIS...WENT AHEAD AND KEPT
~20% POPS GOING ACROSS OUR SOUTH. FORECAST PROXIMITY SOUNDINGS
FROM ACROSS OUR SOUTH SUGGEST 200-400J/KG 0-1MLCAPE VALUES COULD
BE REALIZED SATURDAY AFTERNOON AND MUCH LIKE FRIDAY
AFTERNOON...WILL CONTINUE TO HIGHLIGHT THE CHANCE FOR SMALL HAIL
IN THE HWO. ONCE THE LOW LEVEL BAROCLINIC ZONE DOES CLEAR OUR AREA
SATURDAY...DRY CONDITIONS ARE THEN EXPECTED SATURDAY NIGHT AS AN
OVERALL LACK IN KINEMATIC FORCING OVERTAKES THE AREA.
THE PERIOD OF DRY CONDITIONS WILL BE SHORT-LIVED HOWEVER AS A MID
LEVEL SHORT WAVE ADVANCES SOUTHEAST OUT OF CANADA AND ACROSS THE
UPPER MISSISSIPPI VALLEY...PERHAPS CLIPPING PORTIONS OF THE
NORTHERN AND CENTRAL PLAINS...NEXT MONDAY INTO TUESDAY. DPVA AND
MID LEVEL THERMAL ADVECTION AHEAD OF THE MID LEVEL TROUGH AXIS IS
EXPECTED TO REMAIN EAST/NORTHEAST OF OUR AREA WHICH WOULD
OTHERWISE SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL ALSO
REMAIN EAST/NORTHEAST OF OUR AREA. THAT WONT BE THE CASE HOWEVER
AS A 90-100KT MID LEVEL JET STREAK ACCOMPANIES THE SHORT WAVE
ACROSS PORTIONS OF THE REGION. THE RIGHT-REAR QUADRANT OF THIS MID
LEVEL JET STREAK IS EXPECTED MOVE OVER OUR AREA SUNDAY THROUGH
MONDAY...WITH ENOUGH OF A DIRECT THERMAL CIRCULATION AND RESULTANT
OMEGA FOR PRECIPITATION PRODUCTION ACROSS MOST ALL OF OUR CWA.
ALLBLEND PROVIDED A WIDE RANGE OF POPS DURING THIS 36-HOUR
PERIOD...RANGING FROM ~20% TO ~50%...WITH THE HIGHEST POPS
CURRENTLY FORECAST SUNDAY NIGHT. SAW LITTLE REASON TO DISAGREE
WITH ALLBLEND AND THUS LEFT THESE POPS UNCHANGED. FORECAST
PROXIMITY SOUNDINGS FROM ACROSS THE CWA...PER THE OPERATIONAL GFS
AND EC...SUGGEST THE LOWER TROPOSPHERE SHOULD BE WARM ENOUGH FOR
RAIN DURING THE DAY SUNDAY. WITH CONTINUED LOW LEVEL COLD AIR
ADVECTION HOWEVER A TRANSITION TO SNOWFALL IS APPEARING MORE AND
MORE LIKELY ACROSS MOST ALL OF THE CWA SUNDAY NIGHT AND INTO THE
DAY MONDAY. QPF FIELDS FROM THE OPERATIONAL GFS AND EC BOTH
SUGGEST A COUPLE TENTHS OF AN INCH OF LIQUID PRECIPITATION COULD
BE REALIZED FROM THIS SYSTEM...WHICH SEEMS REASONABLE GIVEN
SUFFICIENT LOWER TROPOSPHERIC MOISTURE WILL BE IN PLACE AND OMEGA
VALUES APPROACHING 10-UBAR/S. GIVEN ALL THIS ONE MIGHT SUSPECT AN
INCH OR TWO OF SNOW ACCUMULATION COULD BE REALIZED SUNDAY NIGHT
INTO MONDAY...BUT SINCE WE ARE NOW APPROACHING EARLY APRIL AND THE
SUN ANGLE IS SO HIGH...IT SEEMS HIGHLY UNLIKELY MUCH OF ANY
ACCUMULATION WILL BE REALIZED AS MUCH OF THE SNOWFALL SHOULD MELT
ON CONTACT WITH THE WARM SURFACE. SO...DESPITE THIS BEING A LATE-
SEASON SNOW EVENT...LITTLE IN THE WAY OF IMPACTS ARE CURRENTLY
EXPECTED ACROSS THE CWA AND WILL LEAVE ANY SUCH WORDING OUT OF THE
HWO. AN OVERALL LACK IN KINEMATIC FORCING SHOULD THEN PROVIDE DRY
CONDITIONS TO OUR AREA MONDAY NIGHT THROUGH THE END OF THE CURRENT
FORECAST PERIOD.
TEMPERATURES IN THE 50S AND 60S ARE STILL EXPECTED FRIDAY THROUGH
SUNDAY...WITH A COOLING TREND PUSHING HIGHS DOWN INTO THE 30S
MONDAY...FOLLOWED BY AFTERNOON HIGHS IN THE 40S AND 50S TO FINISH
THE FORECAST PERIOD. OVERNIGHT LOWS IN THE 30S AND 40S SHOULD BE
OBSERVED FRIDAY NIGHT AND SATURDAY NIGHT...WITH COOLER AIR THEN
PRESENTING OVERNIGHT LOWS IN THE 20S ACROSS MUCH OF THE AREA
SUNDAY NIGHT...IN THE TEENS AND 20S MONDAY NIGHT...AND THEN BACK
INTO THE 20S AND 30S TO FINISH THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 606 AM CDT THU MAR 28 2013
QUIET WEATHER REMAINS IN THE FORECAST FOR THIS TAF PERIOD...THOUGH
A FEW SPRINKLES ARE GOING TO SLIDE JUST NORTH OF THE TERMINAL
EARLY THIS MORNING. SKY COVER WILL BE VARIABLE THROUGH THE
DAY...BUT CEILINGS ARE EXPECTED TO REMAIN VFR. A WEAK SURFACE
PATTERN WILL KEEP WINDS LIGHT AND VARIABLE THIS MORNING...WITH
MORE SOUTHEASTERLY WINDS EXPECTED TO DEVELOP LATER THIS MORNING
AND CONTINUE THROUGH THE AFTERNOON HOURS. SPEEDS ARE EXPECTED TO
TOP OUT IN THE 10 TO 15 MPH RANGE. THIS EVENING/OVERNIGHT LIGHT
AND VARIABLE WINDS WILL RETURN...AND THERE AGAIN IS SOME CONCERN
FOR FOG. AT THIS POINT CONFIDENCE IS LOW ENOUGH NOT TO LOWER
VISIBILITIES TOO MUCH...AND LET FUTURE FORECAST LOOK INTO IT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADO
LONG TERM...BRYANT
AVIATION...ADO
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1046 AM CDT THU MAR 28 2013
.DISCUSSION...
WILL ISSUE A DENSE FOG ADVISORY FOR TOWNER/BENSON/EDDY/RAMSEY AND
CAVALIER COUNTIES THROUGH 18 UTC. AREAS OF DENSE FOG HAVE BEEN
SLOW TO DISSIPATE AND WITH VISIBILITY STILL BELOW 1/4 SM IN AREAS...
FEEL AN ADVISORY IS NEEDED. MAY NEED TO EXTEND IN TIME IF SOLAR
ALOFT CANNOT BREAK IT UP IN THE NEXT FEW HOURS.
OTHER CHALLENGES INCLUDE CLOUD TRENDS AND TEMPERATURES. CLOUD COVER/
FOG OVERNIGHT PLAYED HAVOC WITH MORNING LOWS AND THAT WILL CONTINUE
THROUGH THE DAY. 15 UTC TEMPERATURES RANGE FROM 9 ABOVE AT DEVILS
LAKE WHERE FOG HAS JUST LIFTED TO 39 ABOVE AT WASKISH WITH FULL
SUN. FOG ACROSS THE DEVILS LAKE BASIN WILL LIMIT TEMPERATURE
RECOVERY EVEN IF IT BREAKS UP LATER THIS MORNING. HIGH TEMPERATURES
HERE AT BEST WILL REACH THE MID 20S. ELSEWHERE...EXPECT MID 30S
ALONG THE VALLEY FLOOR TO THE MID TO UPPER 40S ACROSS THE FORESTS
OF NORTHWEST MN. THESE TEMPERATURES...HOWEVER...WILL ALSO BE
DEPENDENT ON NEARLY STATIONARY MID-LEVEL CLOUD COVER FROM HALLOCK TO
ROSEAU AND POINTS SOUTH TO ALEXANDRIA AND WADENA. LATEST RAP SUGGESTS
THESE CLOUDS WILL MOVE VERY LITTLE AND BE SLOW TO DISSIPATE...SO
AREAS WITH PERSISTENT CLOUD COVER MAY NOT REACH FORECAST HIGHS.
OTHERWISE...ILL-DEFINED SURFACE HIGH PRESSURE WILL DOMINATE THE
REGION TODAY...RESULTING IN DRY CONDITIONS AND LIGHT WIND. BESIDES
TWEAKING TEMPERATURES AND CLOUD COVER...NO OTHER MAJOR CHANGES TO
THE FORECAST.
&&
.AVIATION...
AN AREA OF MID CLOUDS CONTINUES TO MOVE NORTHEAST. THERE WILL BE
PATCHY BR AND IFR CONDITIONS PERSISTING NEAR KDVL THROUGH THIS
MORNING...WITH IMPROVING CONDITIONS THEREAFTER.
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT THU MAR 28 2013/
SHORT TERM...
QUITE INTERESTING TEMP PATTERN EARLY THIS MORNING. GFS SHOWS 925
MB WINDS NR 15 KTS IN NE SD/SE ND/WCNTRL MN AND IN THIS AREA SFC
WINDS REMAINING SOUTHEAST 5 TO 10 KTS AND TEMPS ARE QUITE A BIT
HIGHER FARGO-DETROIT LAKES-FERGUS FALLS REGION AND STILL IN THE
MID 20S. NORTH OF THIS AREA DVL-GFK NORTHWARD WINDS ARE LIGHTER
AND TEMPS FALLING INTO THE UPPER SINGLE DIGITS AND SOME FOG
FORMING. HAVE NOTICED PAST HOUR CLOUDS INCREASING IN MID LEVEL
WARM ADV ZONE OVER SE ND AND PUSHING NORTHWARD AND THIS SHOWN
SOMEWHAT ON LATEST RAP MODEL IN SPREADING CLOUD COVER NORTHWARD
THRU THE RED RIVER VALLEY EARLY THIS MORNING. IT ALSO KEEPS TEMPS
MUCH MILDER IN THE SRN VALLEY AND PARTS OF WCNTRL MN THRU 12Z.
SO DOES LOOK LIKE A WARMER TEMP SURGE AND SOME CLOUDS WILL SPREAD
NORTHWARD INTO THE NRN VALLEY THROUGH MID MORNING AND TRIED TO
ADJUST TEMP CURVE FOR THIS.
OVERALL TODAY THOUGH WILL LIKELY SEE SOME CLOUD COVER VALLEY INTO
NW MN IN WARM ADV ZONE AND RAP/GFS SHOWS SOME DECENT 850 MB
MOISTURE IN PLACE. TEMPS SHOULD WARM TODAY AS WELL TO ABOVE
FREEZING IN ALL BUT DVL BASIN. PROVIDED SUN APPEARS AT SOME POINT
IN THE FAR EAST TODAY ANOTHER 40-45 DEGREE DAY IS LIKELY.
ATTENTION TURNS TO LATER FRIDAY AND FRIDAY NIGHT. NOT WELL
ORGANIZED VORT MAX REGION FROM WASHINGTON STATE INTO MONTANA WILL
SPREAD EAST INTO ND/NW MN BY 12Z SAT. SFC LOW WILL BE TO OUR SOUTH
AND THERE WILL A SPREAD OF MOISTURE NORTH AND THEN NORTHEAST INTO
ERN ND AND ESPECIALLY INTO MINNESOTA AND ERN SD AS THIS SYSTEM
PASSES THROUGH. TEMP PROFILES USING BUFKIT SHOW ENOUGH WARMING AT
850 AND BELOW FOR MOSTLY LIQUID PRECIPITATION FOR THIS EVENT. NOW
SFC TEMPS SUGGEST PLAIN LIGHT RAIN FOR FAR SRN ND INTO WCNTRL MN
AND NORTH CENTRAL MN THRU FRI EVE...WITH TEMPS CLOSE ENOUGH TO 32F
IN DVL BASIN AND THE NRN VALLEY FOR RA/FZRA. TEMPS WILL FALL
ENOUGH FOR SOME PSBL FZRA IN FAR SE ND INTO WCNTRL/NORTH CENTRAL
MN OVERNIGHT FRI NIGHT BEFORE PRECIP MOVES OUT SATURDAY MID
MORNING. DID KEEP A LITTLE -SN MIX IN NE ND LATE FRI NIGHT AS
COOLER 850 MB AIR MOVES IN. WPC WWD GRAPHICS DOWNPLAY THREAT FOR
FZRA IN OUR AREA... SREF PROB FOR FZRA ARE HIGHEST IN THE CNTRL
RED RIVER VALLEY FRI NIGHT. REGARDLESS OF PTYPE AMOUNDS LOOK LIGHT
THOUGH A TENTH OF AN INCH OF LIQUID PSBL IN WARMER TEMP REGIME IN
WCNTRL MN.
LONG TERM...SUNDAY THROUGH WEDNESDAY.
LONG WAVE TROUGH OVER WESTERN ATLANTIC WEAKENS AND RETROGRESSES OVER
EASTERN CANADA BY THE END OF THE PERIOD. CONCURRENTLY LONG WAVE
RIDGE OVER THE WEST CANADIAN COAST WEAKENS. GFS WAS THE FASTER
SOLUTION THAN THE ECMWF AT THE BEGINNING OF THE PERIOD AND BECOMES
MORE SO BY THE END OF THE PERIOD. WILL PREFER THE SLOWER ECMWF.
ISOLATED LOW POPS IN THE NORTHEAST ZONES FOR SUN NIGHT WAS REMOVED.
WITH GFS BEING FAST WILL REMOVE POPS ON WED AND WED NIGHT.
LOWERED HIGH TEMPS SUN BY THREE DEGREES BELOW GUIDANCE. OTHERWISE
HIGH TEMPS ARE A DEGREE OR TWO HIGHER THAN YESTERDAYS RUN FOR MON
THROUGH WED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR NDZ006-007-
014-015-024.
MN...NONE.
&&
$$
ROGERS/RIDDLE/DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1014 AM CDT THU MAR 28 2013
.DISCUSSION...UPDATE TO ADJUST HOURLY TRENDS AND TRIMMED AFTERNOON
HIGHS A TAD OVER THE DENSE FOG AREA. MAINLY NORTH AND EAST OF THE
MISSOURI RIVER THE SNOW PACK WAS PROVIDING SOME LOW LEVEL MOISTURE
AND ALLOWED TEMPERATURES TO FALL OVERNIGHT SUCH THAT FOG AND LOW
CLOUDS FORMED. MEANWHILE DECENT WARM ADVECTION WAS OCCURRING FROM
THE SOUTHWEST...RIDING UP AND OVER THE SHALLOW COLD AND MOIST
BOUNDARY LAYER OVER THE SNOW PACK. THE DAYTIME SUN ALONG WITH THE
WARMING FROM THE SOUTHWEST SHOULD DISSIPATE THE FOG DURING THE
MORNING AND EARLY AFTERNOON HOURS. DENSE FOG - 1/4 MILE VISIBILITY
OR LESS - IS NOT EXPECTED TO REMAIN DURING THE AFTERNOON. THE
CURRENT DENSE FOG ADVISORY STILL LOOKS ON TRACK TO BE IN EFFECT
UNTIL NOON CDT.
&&
.AVIATION...AMENDED THE KBIS AND KISN TAF TO REFLECT THE LOWER
VSBYS. HOWEVER TRENDS FOR IMPROVING CIGS AND VSBYS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 623 AM CDT THU MAR 28 2013/
UPDATE...ISSUED AT 622 AM CDT THU MAR 28 2013
MADE SOME MINOR MODIFICATIONS TO ADJUST HOURLY WEATHER
TRENDS...OTHERWISE THE INHERITED FORECAST IS ON TRACK.
DENSE FOG REMAINS NORTH AND EAST OF THE MISSOURI RIVER THIS
THURSDAY MORNING. FOG HAS BEEN STEADILY INCREASING NOW AT
BISMARCK. NO CHANGES TO DENSE FOG HEADLINES.
SHORT TERM...TODAY AND TONIGHT...
ISSUED AT 355 AM CDT THU MAR 28 2013
THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM IS FOG.
LATEST 11-3.9 SATELLITE IMAGERY AND SURFACE OBSERVATIONS AT 08Z
DEPICT AN AREA OF DENSE FOG AND A LOW STRATUS DECK ACROSS NORTHERN
NORTH DAKOTA...EXPANDING SOUTH TOWARDS THE JAMES RIVER VALLEY.
DEWPOINT DEPRESSIONS ACROSS THE SNOW PACK CONTINUE TO HOVER AROUND 0
DEGREES...INDICATING A VERY MOIST BOUNDARY LAYER. THIS WAS ALSO
COINCIDENT WITH CALM TO LIGHT AND VARIABLE WINDS...GENERATING AN
ENVIRONMENT CONDUCIVE TO MAINTAINING DENSE FOG AND THE DEVELOPMENT
OF FOG FURTHER SOUTH ACROSS THE JAMES RIVER VALLEY. ACROSS THE
SNOWLESS SOUTHWEST...THE LACK OF MOISTURE AND PRESENCE OF HIGH THIN
CIRRUS...HAVE LIMITED THE DEVELOPMENT OF FOG. HAVE DECIDED TO REMOVE
PATCHY FOG WORDING IN THE WEATHER GRIDS...WHILE KEEPING AREAS TO
WIDESPREAD FOG/DENSE FOG WORDING ELSEWHERE. THIS IS SUPPORTED BY THE
4Z HRRR...WHERE IT CONTINUES TO DEPICT WIDESPREAD VISIBILITIES BELOW
ONE HALF MILE WITH LOW STRATUS WHERE A SNOW PACK IS PRESENT THROUGH
THE MORNING. AFTER SUNRISE...THE HRRR HAS THE AREAL COVERAGE OF
LOWERED VISIBILITIES SLOWLY ERODING LATE THIS MORNING...WHILE IT AND
OTHER 00Z MODEL GUIDANCE KEEPS LOW LEVEL STRATUS THROUGH AT LEAST
17Z. THEREAFTER...THE STRATUS DECK AND ANY REMAINING FOG WILL GIVE
WAY TO MOSTLY SUNNY CONDITIONS AND WARMING TEMPERATURES INTO THE MID
20S NORTH TO LOWER 50S SOUTHWEST DURING THE AFTERNOON. AT THIS
TIME...WILL KEEP DENSE FOG ADVISORY GOING AS IS SINCE IT IS
REPRESENTATIVE OF CURRENT CONDITIONS.
LONG TERM...FRIDAY THROUGH THURSDAY...
ISSUED AT 355 AM CDT THU MAR 28 2013
NORTHWEST FLOW ALOFT IS FORECAST TO REMAIN IN PLACE THROUGH MUCH
IF NOT ALL OF THE LONG TERM FORECAST PERIOD. WILL SEE AN ACTIVE
FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND. THE
EC/GFS/GEM/NAM ALL CONTINUE TO DEPICT AN EMBEDDED MID LEVEL S/WV
IMPULSE SLIDING SOUTHEAST ACROSS NORTH DAKOTA ALONG WITH AN AREA
OF ASSOCIATED SURFACE LOW PRESSURE FRIDAY/FRIDAY NIGHT. WILL
MAINTAIN CHANCES FOR MIXED PRECIPITATION WITH THE COMBINATION OF
WAA ALOFT COMBINED WITH BELOW/ABOVE FREEZING SURFACE AIR
TEMPERATURES. BOTH THE NAM AND GFS STILL GENERATE DAYTIME
INSTABILITY FRIDAY MID/LATE AFTERNOON OVER SOUTHWEST NORTH
DAKOTA...WITH THE LATEST SPC DAY 2 OUTLOOK NOW JUST OFF TO OUR
SOUTH AND WEST. WILL KEEP AN EYE ON THIS PERIOD OVER THE NEXT FEW
FORECAST CYCLES IN CASE WE NEED TO ADD THUNDER INTO THE FORECAST.
CLOSED UPPER LOW MOVING SOUTH ACROSS CENTRAL CANADA SATURDAY AND
INTO THE GREAT LAKES REGION SUNDAY AND MONDAY WILL BRING A SURGE
OF COLDER AIR INTO THE NORTHERN PLAINS FOR THE EASTER HOLIDAY
WEEKEND. BUMPED HIGH/LOW TEMPERATURES DOWN SEVERAL DEGREES SUNDAY
AND MONDAY. ENOUGH ENERGY ALOFT SHOULD ALSO SEE SOME SLIGHT
CHANCES FOR PRECIPITATION THIS WEEKEND.
WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT
WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS
DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. FOR NOW
STUCK WITH ALLBLEND POPS GIVING ME SLIGHT CHANCES FOR MIXED PRECIP
WED/WED NIGHT. TEMPERATURES MODERATE BACK TO NORMAL MID-WEEK.
AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 510 AM CDT THU MAR 28 2013
HIGH PRESSURE OVER EASTERN NORTH DAKOTA WILL MOVE SLOWLY EAST
THROUGH THE FORECAST PERIOD. THIS WILL CONTINUE BRING A MOIST EAST
TO SOUTHEAST FLOW ACROSS ALL TAF SITES THROUGH THE PERIOD. SATELLITE
IMAGERY AT 10 UTC...CONTINUES TO SHOW AN AREA OF DENSE FOG AND
STRATUS EXPANDING SOUTH FROM NORTHERN NORTH DAKOTA INTO THE JAMES
RIVER VALLEY. LIFR CONDITIONS HAVE BEEN REPORTED AT
KISN/KMOT/KJMS...WHILE VFR CONDITIONS CONTINUE AT KDIK/KBIS.
MVFR/IFR CONDITIONS MAY DEVELOP AT KBIS BUT UNCERTAINTY IS HIGH.
KDIK WILL CONTINUE TO SEE VFR CONDITIONS THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR NDZ001>005-009>013-
021>023-025-035>037-046>048-050-051.
&&
$$
SHORT TERM...JV
LONG TERM....NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
623 AM CDT THU MAR 28 2013
.UPDATE...ISSUED AT 622 AM CDT THU MAR 28 2013
MADE SOME MINOR MODIFICATIONS TO ADJUST HOURLY WEATHER
TRENDS...OTHERWISE THE INHERITED FORECAST IS ON TRACK.
DENSE FOG REMAINS NORTH AND EAST OF THE MISSOURI RIVER THIS
THURSDAY MORNING. FOG HAS BEEN STEADILY INCREASING NOW AT
BISMARCK. NO CHANGES TO DENSE FOG HEADLINES.
&&
.SHORT TERM...TODAY AND TONIGHT...
ISSUED AT 355 AM CDT THU MAR 28 2013
THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM IS FOG.
LATEST 11-3.9 SATELLITE IMAGERY AND SURFACE OBSERVATIONS AT 08Z
DEPICT AN AREA OF DENSE FOG AND A LOW STRATUS DECK ACROSS NORTHERN
NORTH DAKOTA...EXPANDING SOUTH TOWARDS THE JAMES RIVER VALLEY.
DEWPOINT DEPRESSIONS ACROSS THE SNOW PACK CONTINUE TO HOVER AROUND 0
DEGREES...INDICATING A VERY MOIST BOUNDARY LAYER. THIS WAS ALSO
COINCIDENT WITH CALM TO LIGHT AND VARIABLE WINDS...GENERATING AN
ENVIRONMENT CONDUCIVE TO MAINTAINING DENSE FOG AND THE DEVELOPMENT
OF FOG FURTHER SOUTH ACROSS THE JAMES RIVER VALLEY. ACROSS THE
SNOWLESS SOUTHWEST...THE LACK OF MOISTURE AND PRESENCE OF HIGH THIN
CIRRUS...HAVE LIMITED THE DEVELOPMENT OF FOG. HAVE DECIDED TO REMOVE
PATCHY FOG WORDING IN THE WEATHER GRIDS...WHILE KEEPING AREAS TO
WIDESPREAD FOG/DENSE FOG WORDING ELSEWHERE. THIS IS SUPPORTED BY THE
4Z HRRR...WHERE IT CONTINUES TO DEPICT WIDESPREAD VISIBILITIES BELOW
ONE HALF MILE WITH LOW STRATUS WHERE A SNOW PACK IS PRESENT THROUGH
THE MORNING. AFTER SUNRISE...THE HRRR HAS THE AREAL COVERAGE OF
LOWERED VISIBILITIES SLOWLY ERODING LATE THIS MORNING...WHILE IT AND
OTHER 00Z MODEL GUIDANCE KEEPS LOW LEVEL STRATUS THROUGH AT LEAST
17Z. THEREAFTER...THE STRATUS DECK AND ANY REMAINING FOG WILL GIVE
WAY TO MOSTLY SUNNY CONDITIONS AND WARMING TEMPERATURES INTO THE MID
20S NORTH TO LOWER 50S SOUTHWEST DURING THE AFTERNOON. AT THIS
TIME...WILL KEEP DENSE FOG ADVISORY GOING AS IS SINCE IT IS
REPRESENTATIVE OF CURRENT CONDITIONS.
.LONG TERM...FRIDAY THROUGH THURSDAY...
ISSUED AT 355 AM CDT THU MAR 28 2013
NORTHWEST FLOW ALOFT IS FORECAST TO REMAIN IN PLACE THROUGH MUCH
IF NOT ALL OF THE LONG TERM FORECAST PERIOD. WILL SEE AN ACTIVE
FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND. THE
EC/GFS/GEM/NAM ALL CONTINUE TO DEPICT AN EMBEDDED MID LEVEL S/WV
IMPULSE SLIDING SOUTHEAST ACROSS NORTH DAKOTA ALONG WITH AN AREA
OF ASSOCIATED SURFACE LOW PRESSURE FRIDAY/FRIDAY NIGHT. WILL
MAINTAIN CHANCES FOR MIXED PRECIPITATION WITH THE COMBINATION OF
WAA ALOFT COMBINED WITH BELOW/ABOVE FREEZING SURFACE AIR
TEMPERATURES. BOTH THE NAM AND GFS STILL GENERATE DAYTIME
INSTABILITY FRIDAY MID/LATE AFTERNOON OVER SOUTHWEST NORTH
DAKOTA...WITH THE LATEST SPC DAY 2 OUTLOOK NOW JUST OFF TO OUR
SOUTH AND WEST. WILL KEEP AN EYE ON THIS PERIOD OVER THE NEXT FEW
FORECAST CYCLES IN CASE WE NEED TO ADD THUNDER INTO THE FORECAST.
CLOSED UPPER LOW MOVING SOUTH ACROSS CENTRAL CANADA SATURDAY AND
INTO THE GREAT LAKES REGION SUNDAY AND MONDAY WILL BRING A SURGE
OF COLDER AIR INTO THE NORTHERN PLAINS FOR THE EASTER HOLIDAY
WEEKEND. BUMPED HIGH/LOW TEMPERATURES DOWN SEVERAL DEGREES SUNDAY
AND MONDAY. ENOUGH ENERGY ALOFT SHOULD ALSO SEE SOME SLIGHT
CHANCES FOR PRECIPITATION THIS WEEKEND.
WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT
WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS
DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. FOR NOW
STUCK WITH ALLBLEND POPS GIVING ME SLIGHT CHANCES FOR MIXED PRECIP
WED/WED NIGHT. TEMPERATURES MODERATE BACK TO NORMAL MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 510 AM CDT THU MAR 28 2013
HIGH PRESSURE OVER EASTERN NORTH DAKOTA WILL MOVE SLOWLY EAST
THROUGH THE FORECAST PERIOD. THIS WILL CONTINUE BRING A MOIST EAST
TO SOUTHEAST FLOW ACROSS ALL TAF SITES THROUGH THE PERIOD. SATELLITE
IMAGERY AT 10 UTC...CONTINUES TO SHOW AN AREA OF DENSE FOG AND
STRATUS EXPANDING SOUTH FROM NORTHERN NORTH DAKOTA INTO THE JAMES
RIVER VALLEY. LIFR CONDITIONS HAVE BEEN REPORTED AT
KISN/KMOT/KJMS...WHILE VFR CONDITIONS CONTINUE AT KDIK/KBIS.
MVFR/IFR CONDITIONS MAY DEVELOP AT KBIS BUT UNCERTAINTY IS HIGH.
KDIK WILL CONTINUE TO SEE VFR CONDITIONS THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR NDZ001>005-009>013-
021>023-025-035>037-046>048-050-051.
&&
$$
UPDATE...NH
SHORT TERM/AVIATION...LTH
LONG TERM...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
510 AM CDT THU MAR 28 2013
.UPDATE...
ISSUED AT 510 AM CDT THU MAR 28 2013
QUICK UPDATE TO EXPAND THE DENSE FOG ADVISORY INTO BURLEIGH AND
EMMONS COUNTIES EAST THROUGH THE JAMES RIVER VALLEY. LATEST 11-3.9
SATELLITE IMAGERY AND SURFACE OBSERVATIONS AT 10Z...CONTINUE TO
SHOW THE SOUTHWARD EXPANSION OF DENSE FOG...WITH VISIBILITIES LESS
THAN ONE QUARTER OF A MILE AT MOST LOCATIONS NORTH AND EAST OF THE
MISSOURI RIVER...WHERE A MOIST BOUNDARY LAYER AND LIGHT WINDS ARE
CONDUCIVE TO THE MAINTENANCE AND EXPANSION OF DENSE FOG THIS
MORNING.
&&
.SHORT TERM...TODAY AND TONIGHT...
ISSUED AT 355 AM CDT THU MAR 28 2013
THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM IS FOG.
LATEST 11-3.9 SATELLITE IMAGERY AND SURFACE OBSERVATIONS AT 08Z
DEPICT AN AREA OF DENSE FOG AND A LOW STRATUS DECK ACROSS NORTHERN
NORTH DAKOTA...EXPANDING SOUTH TOWARDS THE JAMES RIVER VALLEY.
DEWPOINT DEPRESSIONS ACROSS THE SNOW PACK CONTINUE TO HOVER AROUND 0
DEGREES...INDICATING A VERY MOIST BOUNDARY LAYER. THIS WAS ALSO
COINCIDENT WITH CALM TO LIGHT AND VARIABLE WINDS...GENERATING AN
ENVIRONMENT CONDUCIVE TO MAINTAINING DENSE FOG AND THE DEVELOPMENT
OF FOG FURTHER SOUTH ACROSS THE JAMES RIVER VALLEY. ACROSS THE
SNOWLESS SOUTHWEST...THE LACK OF MOISTURE AND PRESENCE OF HIGH THIN
CIRRUS...HAVE LIMITED THE DEVELOPMENT OF FOG. HAVE DECIDED TO REMOVE
PATCHY FOG WORDING IN THE WEATHER GRIDS...WHILE KEEPING AREAS TO
WIDESPREAD FOG/DENSE FOG WORDING ELSEWHERE. THIS IS SUPPORTED BY THE
4Z HRRR...WHERE IT CONTINUES TO DEPICT WIDESPREAD VISIBILITIES BELOW
ONE HALF MILE WITH LOW STRATUS WHERE A SNOW PACK IS PRESENT THROUGH
THE MORNING. AFTER SUNRISE...THE HRRR HAS THE AREAL COVERAGE OF
LOWERED VISIBILITIES SLOWLY ERODING LATE THIS MORNING...WHILE IT AND
OTHER 00Z MODEL GUIDANCE KEEPS LOW LEVEL STRATUS THROUGH AT LEAST
17Z. THEREAFTER...THE STRATUS DECK AND ANY REMAINING FOG WILL GIVE
WAY TO MOSTLY SUNNY CONDITIONS AND WARMING TEMPERATURES INTO THE MID
20S NORTH TO LOWER 50S SOUTHWEST DURING THE AFTERNOON. AT THIS
TIME...WILL KEEP DENSE FOG ADVISORY GOING AS IS SINCE IT IS
REPRESENTATIVE OF CURRENT CONDITIONS.
.LONG TERM...FRIDAY THROUGH THURSDAY...
ISSUED AT 355 AM CDT THU MAR 28 2013
NORTHWEST FLOW ALOFT IS FORECAST TO REMAIN IN PLACE THROUGH MUCH
IF NOT ALL OF THE LONG TERM FORECAST PERIOD. WILL SEE AN ACTIVE
FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND. THE
EC/GFS/GEM/NAM ALL CONTINUE TO DEPICT AN EMBEDDED MID LEVEL S/WV
IMPULSE SLIDING SOUTHEAST ACROSS NORTH DAKOTA ALONG WITH AN AREA
OF ASSOCIATED SURFACE LOW PRESSURE FRIDAY/FRIDAY NIGHT. WILL
MAINTAIN CHANCES FOR MIXED PRECIPITATION WITH THE COMBINATION OF
WAA ALOFT COMBINED WITH BELOW/ABOVE FREEZING SURFACE AIR
TEMPERATURES. BOTH THE NAM AND GFS STILL GENERATE DAYTIME
INSTABILITY FRIDAY MID/LATE AFTERNOON OVER SOUTHWEST NORTH
DAKOTA...WITH THE LATEST SPC DAY 2 OUTLOOK NOW JUST OFF TO OUR
SOUTH AND WEST. WILL KEEP AN EYE ON THIS PERIOD OVER THE NEXT FEW
FORECAST CYCLES IN CASE WE NEED TO ADD THUNDER INTO THE FORECAST.
CLOSED UPPER LOW MOVING SOUTH ACROSS CENTRAL CANADA SATURDAY AND
INTO THE GREAT LAKES REGION SUNDAY AND MONDAY WILL BRING A SURGE
OF COLDER AIR INTO THE NORTHERN PLAINS FOR THE EASTER HOLIDAY
WEEKEND. BUMPED HIGH/LOW TEMPERATURES DOWN SEVERAL DEGREES SUNDAY
AND MONDAY. ENOUGH ENERGY ALOFT SHOULD ALSO SEE SOME SLIGHT
CHANCES FOR PRECIPITATION THIS WEEKEND.
WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT
WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS
DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. FOR NOW
STUCK WITH ALLBLEND POPS GIVING ME SLIGHT CHANCES FOR MIXED PRECIP
WED/WED NIGHT. TEMPERATURES MODERATE BACK TO NORMAL MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 510 AM CDT THU MAR 28 2013
HIGH PRESSURE OVER EASTERN NORTH DAKOTA WILL MOVE SLOWLY EAST
THROUGH THE FORECAST PERIOD. THIS WILL CONTINUE BRING A MOIST EAST
TO SOUTHEAST FLOW ACROSS ALL TAF SITES THROUGH THE PERIOD. SATELLITE
IMAGERY AT 10 UTC...CONTINUES TO SHOW AN AREA OF DENSE FOG AND
STRATUS EXPANDING SOUTH FROM NORTHERN NORTH DAKOTA INTO THE JAMES
RIVER VALLEY. LIFR CONDITIONS HAVE BEEN REPORTED AT
KISN/KMOT/KJMS...WHILE VFR CONDITIONS CONTINUE AT KDIK/KBIS.
MVFR/IFR CONDITIONS MAY DEVELOP AT KBIS BUT UNCERTAINTY IS HIGH.
KDIK WILL CONTINUE TO SEE VFR CONDITIONS THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR NDZ001>005-009>013-
021>023-025-035>037-046>048-050-051.
&&
$$
UPDATE...LTH
SHORT TERM...LTH
AVIATION...LTH
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1042 AM CDT THU MAR 28 2013
.UPDATE...
FOG HAS CLEARED ACROSS THE AREA AS INDICATED ON WEBCAMS AND OBS.
MID CLOUDS ARE EXPANDING ACROSS THE REGION BUT SHOULD HAVE
NEGLIGIBLE IMPACT ON FORECAST HIGHS. CURRENT PERIOD AND OVERNIGHT
ARE ON TRACK. ADJUSTED FRI NIGHT/SAT MORNING POPS/WX TO LOWER POPS
IN THE WEST AND RAISE THEM EAST OF THE JAMES BASED ON LATEST
GUIDANCE. PRECIP TYPE CONTINUES TO BE A FORECAST CHALLENGE WITH
THIS UPCOMING SYSTEM.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
WAA BAND OF MID LEVEL CLOUDS WERE FORMING THIS MORNING ACROSS THE
FAR EASTERN CWA. THIS SHOULD CONTINUE TO MOVE EAST. THERE WERE
ALSO MORE MID LEVEL CLOUDS MOVING INTO THE WESTERN CWA EARLY THIS
MORNING. OTHERWISE...THE ISSUE THIS MORNING WILL BE THE FOG
FORMATION. NOT MUCH FOR FOG SHOWING UP ON SURFACE OBS OR SATELLITE
EARLY THIS MORNING. ALTHOUGH...SOME WEB CAMS SHOWED SOME FOG OUT
WEST. MUCH OF THE FOG WAS ACROSS THE BORDER IN ND EXPANDING
SOUTHWARD. WITH THE WINDS BECOMING LIGHT AT ABR ALONG WITH A
DECREASING DEW POINT SPREAD...BELIEVE THIS FOG/STRATUS AREA WILL
CONTINUE TO EXPAND SOUTHWARD INTO NORTHERN SD THIS MORNING. THERE
COULD ALSO BE SOME PATCHY DENSE FOG. THE HRRR MODEL ALSO SHOWED
INDICATIONS OF STRATUS AND LOWER VISIBILITIES DEVELOPING INTO
NORTHERN SD THIS MORNING. THUS...CONTINUED WITH FOG THROUGH 10 AM
WITH SOME PATCHY DENSE FOG. THE VISIBLE SATELLITE SHOWED VERY WELL
WHERE THE SNOW COVERED AREAS REMAIN. SURFACE OBS ALSO SHOW THE
SNOW TO BE DEEP ACROSS MUCH OF THE EASTERN CWA WITH UP TO 12
INCHES STILL IN SOME LOCATIONS. THIS SNOW COVER WILL CONTINUE TO
HAVE AN AFFECT ON TEMPERATURES WITH VERY LITTLE MIXING DESPITE THE
LATE MARCH SUN. FOR TODAY THROUGH FRIDAY...ALL OF THE MODELS SHOW
THE LOW LEVEL 925MB AND 850MB TEMPERATURES RISING. THUS...LOOK FOR
HIGH TEMPERATURES TO BE WARMER EACH DAY FROM THURSDAY TO FRIDAY.
THE BARE GROUND AREAS FOR THE COUNTIES EITHER SIDE OF THE MISSOURI
RIVER WILL WARM UP QUITE A BIT TODAY AND FRIDAY. SHOULD HAVE 50S
AND LOWER 60S FOR THIS AREA FOR BOTH DAYS. INCREASED HIGHS ALSO IN
THE EAST AS THE SNOW COVER DIMINISHES OVER THE NEXT FEW DAYS BUT
WILL STILL HAVE A BIG INFLUENCE ON TEMPERATURES. STILL HAVE HIGHS
IN THE MID 30S TO THE MID 40S OVER THE SNOW COVER FOR THURSDAY
AND FRIDAY. WITH MORE SNOW MELT MOISTURE ALONG WITH LIGHT WINDS
AND A GOOD INVERSION...COULD HAVE SOME MORE FOG EAST IN THE CWA
LATE TONIGHT AND FRIDAY MORNING.
THE MODELS CONTINUE TO SHOW A SHORT WAVE TROUGH ALONG WITH A
SURFACE COOL FRONT DROPPING ACROSS THE REGION FRIDAY NIGHT AND
EARLY SATURDAY. THE MODELS ALL SHOW DIFFERENT SOLUTIONS FOR QPF
WITH THIS SYSTEM. INCREASED POPS TO GOOD CHANCES MAINLY EAST IN
THE CWA FOR FRIDAY NIGHT. WITH ALL OF THE WARM AIR ALONG WITH NOT
MUCH COOLING AT THE SURFACE FRIDAY NIGHT...ALL MODEL INDICATIONS
POINT TO JUST RAIN WITH THIS SYSTEM PASSAGE. SATURDAY WILL HAVE
BETTER MIXING WITH MAINLY COOLER TEMPERATURES OUT WEST WITH STILL
UPPER 30S TO THE MID 40S OVER THE DIMINISHED SNOW COVERED AREAS EAST.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
THE LONG TERM PATTERN WILL FEATURE AN UPPER LOW DROPPING SOUTH
ACROSS CANADA...FIRST MOVING ACROSS NORTHERN MANITOBA AND THEN
EASTWARD TO THE GREAT LAKES REGION. THIS WILL PLACE OUR AREA OF
CONCERN IN NORTHWEST FLOW ALOFT...AND MOST OF THE ENERGY
ASSOCIATED WITH THE UPPER LOW WILL STAY NORTH OF OUR AREA.
HOWEVER...RIGHT NOW...THE BEST CHANCES FOR ANY TYPE OF
PRECIPITATION ACROSS OUR CWA WILL BE ON SUNDAY. MODELS ARE SHOWING
SOME CONSENSUS WITH TRACKING A COLD FRONT ACROSS THE REGION...AND
700 MB OMEGA VALUES INDICATE WEAK TO MODERATE FORCING...SO
INCLUDED A CHANCE OF LIGHT SNOW ACROSS THE SOUTHERN HALF OF THE
CWA. TEMPERATURES REALLY PLUMMET BEHIND THIS FEATURE AS WELL. 925
MB TEMPERATURES DROP INTO THE SINGLE DIGITS AND TEENS BELOW ZERO
SUNDAY AND MONDAY. ALLBLEND HAS BEEN SLOW TO RESPOND TO THE
COOLING TREND...SO USED A DETERMINISTIC MODEL BLEND AND DROPPED
TEMPERATURES ACCORDINGLY. THE COLD AIR DOESNT STICK AROUND TOO
LONG HOWEVER...AND RETURN FLOW WINDS ON TUESDAY SHOULD BE ABLE TO
TRANSPORT WARMER AIR BACK INTO THE REGION BY EARLY TO MID WEEK.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
FOG HAS DEVELOPED ACROSS CENTRAL NORTH DAKOTA AND NORTH CENTRAL
SOUTH DAKOTA THIS MORNING. WHILE THERE MAY BE A FEW PATCHES OF
DENSE FOG...MAINLY EXPECT MVFR CIGS AT THE KABR AND KMBG TAF
SITES THIS MORNING. FOG SHOULD BURN OFF QUICKLY AFTER SUNRISE. VFR
CONDITIONS WILL THEN PREVAIL THROUGH THE AFTERNOON HOURS. ANOTHER
CHANCE OF RADIATIONAL FOG IS POSSIBLE LATE TONIGHT AND INTO FRIDAY
MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...MOHR
LONG TERM...SERR
AVIATION...SD
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
639 AM CDT THU MAR 28 2013
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
WAA BAND OF MID LEVEL CLOUDS WERE FORMING THIS MORNING ACROSS THE
FAR EASTERN CWA. THIS SHOULD CONTINUE TO MOVE EAST. THERE WERE
ALSO MORE MID LEVEL CLOUDS MOVING INTO THE WESTERN CWA EARLY THIS
MORNING. OTHERWISE...THE ISSUE THIS MORNING WILL BE THE FOG
FORMATION. NOT MUCH FOR FOG SHOWING UP ON SURFACE OBS OR SATELLITE
EARLY THIS MORNING. ALTHOUGH...SOME WEB CAMS SHOWED SOME FOG OUT
WEST. MUCH OF THE FOG WAS ACROSS THE BORDER IN ND EXPANDING
SOUTHWARD. WITH THE WINDS BECOMING LIGHT AT ABR ALONG WITH A
DECREASING DEW POINT SPREAD...BELIEVE THIS FOG/STRATUS AREA WILL
CONTINUE TO EXPAND SOUTHWARD INTO NORTHERN SD THIS MORNING. THERE
COULD ALSO BE SOME PATCHY DENSE FOG. THE HRRR MODEL ALSO SHOWED
INDICATIONS OF STRATUS AND LOWER VISIBILITIES DEVELOPING INTO
NORTHERN SD THIS MORNING. THUS...CONTINUED WITH FOG THROUGH 10 AM
WITH SOME PATCHY DENSE FOG. THE VISIBLE SATELLITE SHOWED VERY WELL
WHERE THE SNOW COVERED AREAS REMAIN. SURFACE OBS ALSO SHOW THE
SNOW TO BE DEEP ACROSS MUCH OF THE EASTERN CWA WITH UP TO 12
INCHES STILL IN SOME LOCATIONS. THIS SNOW COVER WILL CONTINUE TO
HAVE AN AFFECT ON TEMPERATURES WITH VERY LITTLE MIXING DESPITE THE
LATE MARCH SUN. FOR TODAY THROUGH FRIDAY...ALL OF THE MODELS SHOW
THE LOW LEVEL 925MB AND 850MB TEMPERATURES RISING. THUS...LOOK FOR
HIGH TEMPERATURES TO BE WARMER EACH DAY FROM THURSDAY TO FRIDAY.
THE BARE GROUND AREAS FOR THE COUNTIES EITHER SIDE OF THE MISSOURI
RIVER WILL WARM UP QUITE A BIT TODAY AND FRIDAY. SHOULD HAVE 50S
AND LOWER 60S FOR THIS AREA FOR BOTH DAYS. INCREASED HIGHS ALSO IN
THE EAST AS THE SNOW COVER DIMINISHES OVER THE NEXT FEW DAYS BUT
WILL STILL HAVE A BIG INFLUENCE ON TEMPERATURES. STILL HAVE HIGHS
IN THE MID 30S TO THE MID 40S OVER THE SNOW COVER FOR THURSDAY
AND FRIDAY. WITH MORE SNOW MELT MOISTURE ALONG WITH LIGHT WINDS
AND A GOOD INVERSION...COULD HAVE SOME MORE FOG EAST IN THE CWA
LATE TONIGHT AND FRIDAY MORNING.
THE MODELS CONTINUE TO SHOW A SHORT WAVE TROUGH ALONG WITH A
SURFACE COOL FRONT DROPPING ACROSS THE REGION FRIDAY NIGHT AND
EARLY SATURDAY. THE MODELS ALL SHOW DIFFERENT SOLUTIONS FOR QPF
WITH THIS SYSTEM. INCREASED POPS TO GOOD CHANCES MAINLY EAST IN
THE CWA FOR FRIDAY NIGHT. WITH ALL OF THE WARM AIR ALONG WITH NOT
MUCH COOLING AT THE SURFACE FRIDAY NIGHT...ALL MODEL INDICATIONS
POINT TO JUST RAIN WITH THIS SYSTEM PASSAGE. SATURDAY WILL HAVE
BETTER MIXING WITH MAINLY COOLER TEMPERATURES OUT WEST WITH STILL
UPPER 30S TO THE MID 40S OVER THE DIMINISHED SNOW COVERED AREAS EAST.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
THE LONG TERM PATTERN WILL FEATURE AN UPPER LOW DROPPING SOUTH
ACROSS CANADA...FIRST MOVING ACROSS NORTHERN MANITOBA AND THEN
EASTWARD TO THE GREAT LAKES REGION. THIS WILL PLACE OUR AREA OF
CONCERN IN NORTHWEST FLOW ALOFT...AND MOST OF THE ENERGY
ASSOCIATED WITH THE UPPER LOW WILL STAY NORTH OF OUR AREA.
HOWEVER...RIGHT NOW...THE BEST CHANCES FOR ANY TYPE OF
PRECIPITATION ACROSS OUR CWA WILL BE ON SUNDAY. MODELS ARE SHOWING
SOME CONSENSUS WITH TRACKING A COLD FRONT ACROSS THE REGION...AND
700 MB OMEGA VALUES INDICATE WEAK TO MODERATE FORCING...SO
INCLUDED A CHANCE OF LIGHT SNOW ACROSS THE SOUTHERN HALF OF THE
CWA. TEMPERATURES REALLY PLUMMET BEHIND THIS FEATURE AS WELL. 925
MB TEMPERATURES DROP INTO THE SINGLE DIGITS AND TEENS BELOW ZERO
SUNDAY AND MONDAY. ALLBLEND HAS BEEN SLOW TO RESPOND TO THE
COOLING TREND...SO USED A DETERMINISTIC MODEL BLEND AND DROPPED
TEMPERATURES ACCORDINGLY. THE COLD AIR DOESNT STICK AROUND TOO
LONG HOWEVER...AND RETURN FLOW WINDS ON TUESDAY SHOULD BE ABLE TO
TRANSPORT WARMER AIR BACK INTO THE REGION BY EARLY TO MID WEEK.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
FOG HAS DEVELOPED ACROSS CENTRAL NORTH DAKOTA AND NORTH CENTRAL
SOUTH DAKOTA THIS MORNING. WHILE THERE MAY BE A FEW PATCHES OF
DENSE FOG...MAINLY EXPECT MVFR CIGS AT THE KABR AND KMBG TAF
SITES THIS MORNING. FOG SHOULD BURN OFF QUICKLY AFTER SUNRISE. VFR
CONDITIONS WILL THEN PREVAIL THROUGH THE AFTERNOON HOURS. ANOTHER
CHANCE OF RADIATIONAL FOG IS POSSIBLE LATE TONIGHT AND INTO FRIDAY
MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...MOHR
LONG TERM...SERR
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1102 AM CDT THU MAR 28 2013
.UPDATE...
NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST OTHER THAN MINOR
ADJUSTMENTS TO THE HOURLY GRIDS. LOW CLOUDS CONTINUE TO STREAM
NORTHWARD WITH STRONG LOW LEVEL MOISTURE ADVECTION. DEWPOINTS ARE
RUNNING 20 TO 25 DEGREES HIGHER THAN THIS TIME YESTERDAY. CLOUDY
AND INCREASINGLY MOIST CONDITIONS EXPECTED TO PERSIST THROUGH THE
REMAINDER OF THE DAY.
DUNN
&&
.AVIATION...
FOR THE 12Z TAFS...TIMING THE ONSET OF FLIGHT CATEGORY
RESTRICTIONS ASSOCIATED WITH STRATOCUMULUS CLOUD BASES IS THE
PRIMARY AVIATION WEATHER CONCERN.
UPSTREAM OF THE DFW AREA IS A NEARLY SOLID DECK OF STRATOCUMULUS
WITH BASES OBSERVED ANYWHERE FROM 2500 TO 5000 FT AGL. AT THE TIME
OF THIS DISCUSSION THE LEADING EDGE OF THESE CLOUDS WERE OVER
KACT...MOVING NORTH AT APPROXIMATELY 20 KTS. ITS DIFFICULT TO SAY
WITH A HIGH DEGREE OF CONFIDENCE WHETHER CIGS WILL BE HIGH MVFR OR
LOW VFR WHEN THEY BUILD OVER DFW AREA TAF SITES THIS MORNING. WITH
THESE TAFS SIDED WITH LOW VFR CIGS BECAUSE IT LOOKS LIKE WE WILL
SEE AN HOUR OR TWO OF SUN BEFORE THE CLOUDS BUILD OVER THE AREA.
WITH UPSTREAM CIGS OBSERVING MORE VFR CIGS THAN MVFR ALREADY...
THINK THE ADDITIONAL CONSIDERATION OF SOME BRIEF SURFACE HEATING
TIPS THE SCALE IN FAVOR OF HIGHER CIGS.
LOW VFR CIGS WILL PERSIST UNTIL AFTER SUNSET WHEN NOCTURNAL
COOLING AND PERSISTENT MOIST ADVECTION WILL ALLOW CIGS TO LOWER A
CATEGORY. THIS PROCESS WILL CONTINUE OVERNIGHT...ALLOWING CIGS TO
LOWER BELOW 2 KFT BEFORE SUNRISE.
WE DO HAVE A SLIGHT CHANCE OF RAIN SHOWERS AROUND AREA TAF
SITES...MOST LIKELY AFTER 21Z. FORECAST SOUNDINGS INDICATE A VERY
SHALLOW LAYER OF POSITIVE CAPE UNDER A STOUT INVERSION LOCATED
NEAR 800 MB ACCORDING TO THE 12Z FWD RAOB. IF THIS CAPE IS
REALIZED...SHALLOW CONVECTION IN THE FORM OF ISOLATED RAIN SHOWERS
COULD DEVELOP LATE THIS AFTERNOON OR EVENING. CONFIDENCE IS TOO
LOW TO MENTION THIS IN THE TAFS AT THIS TIME.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 404 AM CDT THU MAR 28 2013/
CURRENT UPPER AIR ANALYSIS DEPICTS UPPER TROUGHS OVER THE
NORTHEAST CONUS...NORTHWEST CANADA AND THE CENTRAL PACIFIC OCEAN
WITH WEAK RIDGING ACROSS THE WESTERN CONUS. THIS PLACES NORTH
TEXAS UNDER MODERATE WESTERLY FLOW ALOFT. AT THE SURFACE...A
SURFACE LOW HAS DEVELOPED ACROSS EASTERN NEW MEXICO WITH A SURFACE
TROUGH EXTENDING TO THE NORTHEAST INTO THE TEXAS PANHANDLE AND
INTO CENTRAL OKLAHOMA. BREEZY SOUTHERLY WINDS IN THE LOW LEVELS OF
THE ATMOSPHERE ARE EXPECTED ONCE AGAIN TODAY. LOW CLOUDS HAVE
DEVELOPED TO OUR SOUTH AND WILL CONTINUE TO STREAM NORTHWARD THIS
MORNING. WEST WINDS AT 800 MB HAVE BROUGHT WARMER TEMPERATURES
ALOFT...AND A STRONG CAPPING INVERSION IS NOW IN PLACE. THIS
INVERSION SHOULD PREVENT THE LOW CLOUDS FROM COMPLETELY MIXING OUT
TODAY...AND CLOUDS SHOULD BE AROUND FOR MOST OF THE DAY.
WITHIN THE WESTERLY FLOW ALOFT...A COUPLE OF WEAK EMBEDDED
DISTURBANCES ARE EXPECTED TO MOVE THROUGH OKLAHOMA. THE FIRST ONE
WILL MOVE THROUGH THIS AFTERNOON...BUT WITH WEAK LIFT FOR OUR AREA AND
THE STRONG CAP IN PLACE...RAIN CHANCES WILL BE MINIMAL. THE NAM
AND RAP ARE MIXING US OUT A BIT MORE THAN THE GFS AND ACTUALLY
SHOW A SMALL AMOUNT OF CAPE UNDER THE CAP. THIS COULD LEAD TO A
FEW SHOWERS LATE THIS AFTERNOON...BUT CONFIDENCE WASNT HIGH
ENOUGH TO MENTION ANYTHING IN THE FORECAST. A SECOND WEAK
SHORTWAVE WILL AGAIN MOVE THROUGH OKLAHOMA LATE TONIGHT. THE BEST
CHANCES OF RAIN SHOULD BE IN OKLAHOMA...WHERE THE BEST LIFT AND
SURFACE TROUGH WILL BE LOCATED. COULD SEE A COUPLE OF SHOWERS OR
STORMS ALONG THE RED RIVER...AND WILL CONTINUE WITH A 20 POP
THERE.
THE STRONG CAP WILL CONTINUE TO HAVE A HOLD ON OUR FORECAST FOR
FRIDAY. THE SURFACE LOW WILL HAVE MOVED A BIT FURTHER EAST...AND
THE BEST CHANCE FOR THE CAP TO BREAK WOULD BE TO THE EAST OF THE
LOW NEAR CHILDRESS. IF THIS WERE TO OCCUR...WE COULD SEE ACTIVITY
MOVE INTO THE NORTHWEST ZONES FRIDAY EVENING. BUT AGAIN...THE CAP
REMAINS IN PLACE AND ACTIVITY WOULD NOT BE EXPECTED TO THRIVE
LONG. WILL CONTINUE WITH A 30 POP FOR THE NORTHWESTERN ZONES AND
20S FOR THE REST OF THE NORTHERN HALF OF THE CWA.
FOR SATURDAY...THE NAM COMPLETELY ERODES THE CAP AND HAS PRECIP FOR
THE AREA. HOWEVER...THIS IS FEEDBACK FROM THE NAM BRINGING IN
PRECIP THROUGH THE REGION FROM THE FRIDAY NIGHT SYSTEM. BASICALLY
THE NAM IS COOLING THE WARM LAYER AS THE MODEL IS COMPUTING RAIN
EVAPORATING WITHIN THIS LAYER. THEREFORE AM LESS OPTIMISTIC THAN
THE NAM FOR POPS SATURDAY...AS CONFIDENCE IS NOT HIGH WITH THE
FRIDAY SYSTEM BRINGING WIDESPREAD RAIN FRIDAY NIGHT.
HOWEVER...SOME STORMS ARE POSSIBLE...AND ANY STORMS THAT DEVELOP
TO OUR WEST NEAR THE SURFACE LOW...WOULD HAVE MODERATE SHEAR AND
1500+ J/KG OF CAPE TO WORK WITH. A COUPLE OF STRONG TO SEVERE
STORMS ARE POSSIBLE.
ON SUNDAY...THE UPPER LOW CURRENTLY OVER NORTHWEST CANADA WILL
PUSH INTO THE CENTRAL PLAINS AND DRIVE A COLD FRONT SOUTHWARD. THE
UPPER LOW CURRENTLY OVER THE CENTRAL PACIFIC OCEAN WILL BE MOVING
ONSHORE CENTRAL CALIFORNIA AT THE SAME TIME. AS THE MAIN FORCING
OF THE NORTHERN UPPER LOW SHIFTS EAST...MODELS NOW ADVERTISE THE
COLD FRONT STALLING IN OKLAHOMA...DUE TO THE APPROACHING TROUGH
FROM THE WEST. PREVIOUS MODEL RUNS BROUGHT THE FRONT THROUGH THE
CWA AND HAD TO ADJUST POPS NORTHWARD AND KEEP THE HIGHEST POPS
NORTH OF THE I-20 CORRIDOR...CLOSEST TO THE STALLED FRONTAL
BOUNDARY.
THIS FRONT WILL QUICKLY SURGE NORTHWARD SUNDAY NIGHT AS THE WEST
COAST UPPER LOW PUSHES EAST. HOWEVER...AT THE SAME TIME...ANOTHER
IMPULSE ON THE BACKSIDE OF THE NORTHERN UPPER LOW WILL PUSH
THROUGH THE PLAINS...DRIVING A STRONGER FRONT SOUTH MONDAY. MODELS
ARE FASTER WITH THIS FRONT...SWEEPING IT THROUGH THE CWA MONDAY
AFTERNOON AND EVENING. WITH THIS QUICKER TIMING...HAD TO DECREASE
TEMPERATURES MONDAY NIGHT AND TUESDAY.
MAJOR DISCREPANCIES BETWEEN THE GFS AND ECMWF ARE APPARENT FOR
TUESDAY WITH THE HANDLING OF THE WEST COAST TROUGH. MODELS ARE
CONSISTENT WITH THE WEAKENING OF THE LOW...BUT THE ECMWF IS MOST
AGGRESSIVE WITH THIS WEAKENING TREND...AND MOVES IT THROUGH THE
AREA WEDNESDAY. THE GFS IS A BIT STRONGER THAN THE ECMWF AND
BRINGS THE TROUGH THROUGH TUESDAY WITH MORE PRECIP. THE ECMWF
WOULD THUS HAVE LESS PRECIP AS MOISTURE WOULD BE SCOURED OUT
BEHIND THE FRONT GIVEN THE LATER TIMING. NEVERTHELESS...WITH BOTH
MODELS WEAKENING THE LOW...WIDESPREAD RAIN CHANCES FOR TUESDAY
DONT APPEAR AS HIGH AS YESTERDAY. TEMPERATURES TUESDAY AND
WEDNESDAY BEHIND THE FRONT WILL BE IN THE 50S FOR HIGHS AND
30S/40S FOR LOWS.
HAMPSHIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 69 57 72 59 76 / 5 10 10 20 30
WACO, TX 70 57 73 59 75 / 5 5 10 10 20
PARIS, TX 68 54 69 58 72 / 5 20 20 20 30
DENTON, TX 68 55 72 57 76 / 5 10 20 30 30
MCKINNEY, TX 68 55 69 58 74 / 5 10 20 20 30
DALLAS, TX 71 57 73 59 75 / 5 10 10 20 30
TERRELL, TX 69 55 71 59 73 / 5 5 10 20 30
CORSICANA, TX 70 56 71 59 73 / 5 5 10 10 30
TEMPLE, TX 70 56 72 59 76 / 5 5 10 10 20
MINERAL WELLS, TX 71 55 73 56 80 / 5 10 10 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
649 AM CDT THU MAR 28 2013
.AVIATION...
FOR THE 12Z TAFS...TIMING THE ONSET OF FLIGHT CATEGORY
RESTRICTIONS ASSOCIATED WITH STRATOCUMULUS CLOUD BASES IS THE
PRIMARY AVIATION WEATHER CONCERN.
UPSTREAM OF THE DFW AREA IS A NEARLY SOLID DECK OF STRATOCUMULUS
WITH BASES OBSERVED ANYWHERE FROM 2500 TO 5000 FT AGL. AT THE TIME
OF THIS DISCUSSION THE LEADING EDGE OF THESE CLOUDS WERE OVER
KACT...MOVING NORTH AT APPROXIMATELY 20 KTS. ITS DIFFICULT TO SAY
WITH A HIGH DEGREE OF CONFIDENCE WHETHER CIGS WILL BE HIGH MVFR OR
LOW VFR WHEN THEY BUILD OVER DFW AREA TAF SITES THIS MORNING. WITH
THESE TAFS SIDED WITH LOW VFR CIGS BECAUSE IT LOOKS LIKE WE WILL
SEE AN HOUR OR TWO OF SUN BEFORE THE CLOUDS BUILD OVER THE AREA.
WITH UPSTREAM CIGS OBSERVING MORE VFR CIGS THAN MVFR ALREADY...
THINK THE ADDITIONAL CONSIDERATION OF SOME BRIEF SURFACE HEATING
TIPS THE SCALE IN FAVOR OF HIGHER CIGS.
LOW VFR CIGS WILL PERSIST UNTIL AFTER SUNSET WHEN NOCTURNAL
COOLING AND PERSISTENT MOIST ADVECTION WILL ALLOW CIGS TO LOWER A
CATEGORY. THIS PROCESS WILL CONTINUE OVERNIGHT...ALLOWING CIGS TO
LOWER BELOW 2 KFT BEFORE SUNRISE.
WE DO HAVE A SLIGHT CHANCE OF RAIN SHOWERS AROUND AREA TAF
SITES...MOST LIKELY AFTER 21Z. FORECAST SOUNDINGS INDICATE A VERY
SHALLOW LAYER OF POSITIVE CAPE UNDER A STOUT INVERSION LOCATED
NEAR 800 MB ACCORDING TO THE 12Z FWD RAOB. IF THIS CAPE IS
REALIZED...SHALLOW CONVECTION IN THE FORM OF ISOLATED RAIN SHOWERS
COULD DEVELOP LATE THIS AFTERNOON OR EVENING. CONFIDENCE IS TOO
LOW TO MENTION THIS IN THE TAFS AT THIS TIME.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 404 AM CDT THU MAR 28 2013/
CURRENT UPPER AIR ANALYSIS DEPICTS UPPER TROUGHS OVER THE
NORTHEAST CONUS...NORTHWEST CANADA AND THE CENTRAL PACIFIC OCEAN
WITH WEAK RIDGING ACROSS THE WESTERN CONUS. THIS PLACES NORTH
TEXAS UNDER MODERATE WESTERLY FLOW ALOFT. AT THE SURFACE...A
SURFACE LOW HAS DEVELOPED ACROSS EASTERN NEW MEXICO WITH A SURFACE
TROUGH EXTENDING TO THE NORTHEAST INTO THE TEXAS PANHANDLE AND
INTO CENTRAL OKLAHOMA. BREEZY SOUTHERLY WINDS IN THE LOW LEVELS OF
THE ATMOSPHERE ARE EXPECTED ONCE AGAIN TODAY. LOW CLOUDS HAVE
DEVELOPED TO OUR SOUTH AND WILL CONTINUE TO STREAM NORTHWARD THIS
MORNING. WEST WINDS AT 800 MB HAVE BROUGHT WARMER TEMPERATURES
ALOFT...AND A STRONG CAPPING INVERSION IS NOW IN PLACE. THIS
INVERSION SHOULD PREVENT THE LOW CLOUDS FROM COMPLETELY MIXING OUT
TODAY...AND CLOUDS SHOULD BE AROUND FOR MOST OF THE DAY.
WITHIN THE WESTERLY FLOW ALOFT...A COUPLE OF WEAK EMBEDDED
DISTURBANCES ARE EXPECTED TO MOVE THROUGH OKLAHOMA. THE FIRST ONE
WILL MOVE THROUGH THIS AFTERNOON...BUT WITH WEAK LIFT FOR OUR AREA AND
THE STRONG CAP IN PLACE...RAIN CHANCES WILL BE MINIMAL. THE NAM
AND RAP ARE MIXING US OUT A BIT MORE THAN THE GFS AND ACTUALLY
SHOW A SMALL AMOUNT OF CAPE UNDER THE CAP. THIS COULD LEAD TO A
FEW SHOWERS LATE THIS AFTERNOON...BUT CONFIDENCE WASNT HIGH
ENOUGH TO MENTION ANYTHING IN THE FORECAST. A SECOND WEAK
SHORTWAVE WILL AGAIN MOVE THROUGH OKLAHOMA LATE TONIGHT. THE BEST
CHANCES OF RAIN SHOULD BE IN OKLAHOMA...WHERE THE BEST LIFT AND
SURFACE TROUGH WILL BE LOCATED. COULD SEE A COUPLE OF SHOWERS OR
STORMS ALONG THE RED RIVER...AND WILL CONTINUE WITH A 20 POP
THERE.
THE STRONG CAP WILL CONTINUE TO HAVE A HOLD ON OUR FORECAST FOR
FRIDAY. THE SURFACE LOW WILL HAVE MOVED A BIT FURTHER EAST...AND
THE BEST CHANCE FOR THE CAP TO BREAK WOULD BE TO THE EAST OF THE
LOW NEAR CHILDRESS. IF THIS WERE TO OCCUR...WE COULD SEE ACTIVITY
MOVE INTO THE NORTHWEST ZONES FRIDAY EVENING. BUT AGAIN...THE CAP
REMAINS IN PLACE AND ACTIVITY WOULD NOT BE EXPECTED TO THRIVE
LONG. WILL CONTINUE WITH A 30 POP FOR THE NORTHWESTERN ZONES AND
20S FOR THE REST OF THE NORTHERN HALF OF THE CWA.
FOR SATURDAY...THE NAM COMPLETELY ERODES THE CAP AND HAS PRECIP FOR
THE AREA. HOWEVER...THIS IS FEEDBACK FROM THE NAM BRINGING IN
PRECIP THROUGH THE REGION FROM THE FRIDAY NIGHT SYSTEM. BASICALLY
THE NAM IS COOLING THE WARM LAYER AS THE MODEL IS COMPUTING RAIN
EVAPORATING WITHIN THIS LAYER. THEREFORE AM LESS OPTIMISTIC THAN
THE NAM FOR POPS SATURDAY...AS CONFIDENCE IS NOT HIGH WITH THE
FRIDAY SYSTEM BRINGING WIDESPREAD RAIN FRIDAY NIGHT.
HOWEVER...SOME STORMS ARE POSSIBLE...AND ANY STORMS THAT DEVELOP
TO OUR WEST NEAR THE SURFACE LOW...WOULD HAVE MODERATE SHEAR AND
1500+ J/KG OF CAPE TO WORK WITH. A COUPLE OF STRONG TO SEVERE
STORMS ARE POSSIBLE.
ON SUNDAY...THE UPPER LOW CURRENTLY OVER NORTHWEST CANADA WILL
PUSH INTO THE CENTRAL PLAINS AND DRIVE A COLD FRONT SOUTHWARD. THE
UPPER LOW CURRENTLY OVER THE CENTRAL PACIFIC OCEAN WILL BE MOVING
ONSHORE CENTRAL CALIFORNIA AT THE SAME TIME. AS THE MAIN FORCING
OF THE NORTHERN UPPER LOW SHIFTS EAST...MODELS NOW ADVERTISE THE
COLD FRONT STALLING IN OKLAHOMA...DUE TO THE APPROACHING TROUGH
FROM THE WEST. PREVIOUS MODEL RUNS BROUGHT THE FRONT THROUGH THE
CWA AND HAD TO ADJUST POPS NORTHWARD AND KEEP THE HIGHEST POPS
NORTH OF THE I-20 CORRIDOR...CLOSEST TO THE STALLED FRONTAL
BOUNDARY.
THIS FRONT WILL QUICKLY SURGE NORTHWARD SUNDAY NIGHT AS THE WEST
COAST UPPER LOW PUSHES EAST. HOWEVER...AT THE SAME TIME...ANOTHER
IMPULSE ON THE BACKSIDE OF THE NORTHERN UPPER LOW WILL PUSH
THROUGH THE PLAINS...DRIVING A STRONGER FRONT SOUTH MONDAY. MODELS
ARE FASTER WITH THIS FRONT...SWEEPING IT THROUGH THE CWA MONDAY
AFTERNOON AND EVENING. WITH THIS QUICKER TIMING...HAD TO DECREASE
TEMPERATURES MONDAY NIGHT AND TUESDAY.
MAJOR DISCREPANCIES BETWEEN THE GFS AND ECMWF ARE APPARENT FOR
TUESDAY WITH THE HANDLING OF THE WEST COAST TROUGH. MODELS ARE
CONSISTENT WITH THE WEAKENING OF THE LOW...BUT THE ECMWF IS MOST
AGGRESSIVE WITH THIS WEAKENING TREND...AND MOVES IT THROUGH THE
AREA WEDNESDAY. THE GFS IS A BIT STRONGER THAN THE ECMWF AND
BRINGS THE TROUGH THROUGH TUESDAY WITH MORE PRECIP. THE ECMWF
WOULD THUS HAVE LESS PRECIP AS MOISTURE WOULD BE SCOURED OUT
BEHIND THE FRONT GIVEN THE LATER TIMING. NEVERTHELESS...WITH BOTH
MODELS WEAKENING THE LOW...WIDESPREAD RAIN CHANCES FOR TUESDAY
DONT APPEAR AS HIGH AS YESTERDAY. TEMPERATURES TUESDAY AND
WEDNESDAY BEHIND THE FRONT WILL BE IN THE 50S FOR HIGHS AND
30S/40S FOR LOWS.
HAMPSHIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 69 57 72 59 76 / 5 10 10 20 30
WACO, TX 71 57 73 59 75 / 5 5 10 10 20
PARIS, TX 67 54 69 58 72 / 5 20 20 20 30
DENTON, TX 69 55 72 57 76 / 5 10 20 30 30
MCKINNEY, TX 69 55 69 58 74 / 5 10 20 20 30
DALLAS, TX 71 57 73 59 75 / 5 10 10 20 30
TERRELL, TX 69 55 71 59 73 / 5 5 10 20 30
CORSICANA, TX 70 56 71 59 73 / 5 5 10 10 30
TEMPLE, TX 70 56 72 59 76 / 5 5 10 10 20
MINERAL WELLS, TX 71 55 73 56 80 / 5 10 10 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
249 PM CDT THU MAR 28 2013
.DISCUSSION...
332 AM CDT
WHILE THE FORECAST IS GENERALLY QUIET...THERE ARE SOME CHALLENGES.
THESE CONTINUE TO BE TEMPERATURES AND WEIGHING THE EFFECTS OF THE
LAKE BREEZE FOR DOWNTOWN CHICAGO AND OTHER NEARBY
LOCATIONS...FOLLOWED BY RAIN LIKELIHOOD SATURDAY NIGHT AND THE
PATTERN BEHIND THE COLD FRONT.
WHILE THE UPPER AND MID-LEVEL WIND FLOW REMAINS NORTHWESTERLY...THE
AIR MASS IS BECOMING MORE PACIFIC ORIGIN THAN MODIFIED ARCTIC PER
UPPER AIR ANALYSES. THE HIGH PRESSURE RIDGE IS CENTERED NEAR THE
MISSISSIPPI RIVER EARLY THIS MORNING AND WILL MOVE OVER THE AREA
BY AFTERNOON AND PERSIST THROUGH LATE IN THE DAY FRIDAY. THIS
LIGHT PRESSURE GRADIENT FORCE ALONG WITH MORE SUNSHINE TOWARD
WARMING TEMPERATURES OVER LAND WILL CERTAINLY FOSTER LAKE BREEZE
DEVELOPMENT. IT IS LIKELY THIS WILL BE EARLIER THAN THE PAST TWO
DAYS GIVEN THE SETUP. THIS IS SUPPORTED BY THE HRRR WHICH STARTS
THE LAKE BREEZE NEAR 11 AM. HAVE CONTINUED TO REFLECT A DROPPING
AND THEN STABILIZING TEMPERATURE TREND NEAR THE LAKE SHORE...WITH
AFTERNOON READINGS LIKELY IN THE UPPER AND MAYBE EVEN MID 30S. AS
FOR THE REMAINDER OF THE FORECAST AREA...SOME CU IS POSSIBLE
NAMELY OVER NE IL AND NW IN AS THE LAST OF THE COLD AIR ALOFT
SCOOTS OUT. THE WARM AIR ADVECTION IN ITS PLACE AND FURTHER MIXING
SHOULD ALLOW FOR WIDESPREAD HIGHS IN THE MID 40S...BASICALLY THE
HIGHS OF YESTERDAY PLUS THREE TO FOUR DEGREES.
ANOTHER SHARP UPPER TROUGH WILL DIG INTO THE GREAT LAKES REGION BY
EARLY NEXT WEEK...WITH A FIRST SEEMINGLY WELL-DEFINED SHORT WAVE
AND SURFACE TROUGH ADVANCING THROUGH THE AREA SATURDAY NIGHT. THE
NAM...GFS...AND EC ALL AGREE ON A SURFACE LOW RESPONSE FROM
NORTHERN MO THROUGH OUR AREA DURING SATURDAY NIGHT...WITH A
FOCUSED MOIST ADVECTION AND CONVERGENCE AREA MOVING ACROSS WITHIN
FAIRLY GOOD UPPER FORCING. HAVE CONTINUED TO INCH UP POPS FOR
SATURDAY EVENING. SOME GUIDANCE INCLUDING THE EC AND NAM ALREADY
SPREAD RAIN INTO THE WESTERN AND SOUTHWESTERN FORECAST AREA AS
EARLY AS MID TO LATE AFTERNOON AND HAVE CONTINUED TO ACCOUNT FOR
THAT. MORE MEMBERS OF THE GEFS SHOW POTENTIAL FOR OVER A QUARTER
OF AN INCH BUT VERY FEW INCLUDING IN THE SREF GIVE OVER ONE HALF
AN INCH.
TEMPERATURES IN ADVANCE OF THE FRONT LOOK TO EXCEED 50 AREA-WIDE
ON SATURDAY WITH A MILD NIGHT AS THE CLOUDS AND THE BOUNDARY PASS.
SUNDAY TEMPERATURES IN THE UPPER 40S TO MID 50S ARE LOOKING MORE
CONFIDENT THANKS TO A HIGH STARTING POINT AND THE FIRST COLD FRONT
NOT BRINGING MUCH OF A COLD AIR DUMP. THAT WILL COME SUNDAY NIGHT
WITH A COOL PATTERN TO START NEXT WEEK AS 850 MB TEMPERATURES DROP
ONCE AGAIN TO ONE AND A HALF STANDARD DEVIATIONS BELOW NORMAL /PER
GEFS AND EC FORECASTS/. HAVE ADAPTED LOCAL CLIMATOLOGICAL RESEARCH
FOR THESE 850MB TEMPERATURES OF -10C INTO THE FORECAST...WHICH
INDICATE GOOD POTENTIAL FOR HIGHS TO REMAIN AT OR BELOW 40 IN
CHICAGO...WHICH ALREADY LOOKED PRETTY GOOD IN THE FORECAST. ONE
THING ABOUT NEXT WEEK COMPARED TO THE COOL TEMPERATURES OF EARLIER
THIS WEEK IS THAT WHILE UNDER CYCLONIC FLOW AGAIN WE WILL BE LESS
ENTRENCHED AND THUS LESS FAVORED FOR CONTINUOUS STARTOCU. WE
SHOULD HAVE SOME DURING THE DAYS BUT WE ARE FURTHER FROM THE
CYCLONIC CENTER WHICH WILL BE UP IN QUEBEC ALREADY BY MONDAY
AFTERNOON. NO SIGN OF A MAJOR WARM-UP BUT A GRADUAL ONE LATE NEXT
WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE HAS DEVELOPED NEAR THE LAKE SHORE. POTENTIAL LATE
THIS AFTERNOON FOR IT TO MOVE INLAND FAR ENOUGH TO PASS THROUGH
MDW AND ORD.
PAW
//DISCUSSION...UPDATED 18Z...
A HIGH PRESSURE RIDGE DOMINATES NORTHERN ILLINOIS AND NORTHWEST
INDIANA WEATHER TODAY. FEW CLOUDS AND LIGHT WINDS. A LAKE BREEZE
HAS DEVELOPED AND PUSHED PAST GYY ALREADY. THE QUESTION FOR THE
AFTERNOON IS WHETHER IT WILL MOVE INLAND FAR ENOUGH TO PASS
THROUGH MDW AND ORD. WITH THE RIDGE AXIS JUST TO THE WEST OF THE
TERMINALS AND GOOD HEATING IT SEEMS LIKELY THAT ORD AND MDW WILL
SEE WINDS GO TO THE NORTHEAST BY LATE THIS AFTERNOON.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE THAT LAKE BREEZE WILL PASS MDW OR ORD...AND
TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT AND SATURDAY...VFR.
* SATURDAY NIGHT....MVFR. RAIN LIKELY.
* SUNDAY...MVFR EARLY...THEN VFR. W-WNW WINDS GUSTING 20-25KT LATE
MORNING THROUGH AFTERNOON.
* SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR.
TRS
&&
.MARINE...
230 PM CDT
BROAD RIDGE OF HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER
OVER THE ENTIRE GREAT LAKES REGION...STRETCHING FROM HUDSON BAY
SOUTH TO THE GULF OF MEXICO. THIS RIDGE WILL CONSOLIDATE SLIGHTLY
AND BECOME FOCUSED OVERNIGHT ACROSS THE GREAT LAKES AND TENNESSEE
VALLEY. GUIDANCE CONTINUES TO SUGGEST THE RIDGE WILL REMAIN
OVERHEAD THROUGH SATURDAY MORNING...DRIFTING EAST BY SATURDAY
NIGHT. THE FOCUS THEN TURNS TOWARDS A DEVELOPING LOW PRESSURE
SYSTEM THAT WILL QUICKLY SLIDE NORTHEAST TOWARDS THE UPPER MIDWEST
AND NORTHERN GREAT LAKES REGION...WITH A TIGHTENING WIND GRADIENT.
IT APPEARS THAT WITH THE INCREASING SOUTHERLY WINDS SATURDAY NIGHT
INTO SUNDAY THAT WAVES WILL BE BUILDING OVER THE OPEN WATERS OF
LAKE MICHIGAN. WITH THE APPROACHING COLD FRONT LATE IN THE
WEEKEND...AND GUSTY WINDS...THE POTENTIAL FOR GALES STILL LOOKS
POSSIBLE OVERNIGHT SUNDA INTO MONDAY MORNING. THEN HIGH PRESSURE
BUILDS INTO THE REGION YET AGAIN FROM CENTRAL CANADA...WITH A
PERIOD OF NORTHWEST WINDS BUILDING WAVES FOR THE SOUTHERN HALF OF
LAKE MICHIGAN EARLY NEXT WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
247 PM CDT THU MAR 28 2013
.DISCUSSION...
332 AM CDT
WHILE THE FORECAST IS GENERALLY QUIET...THERE ARE SOME CHALLENGES.
THESE CONTINUE TO BE TEMPERATURES AND WEIGHING THE EFFECTS OF THE
LAKE BREEZE FOR DOWNTOWN CHICAGO AND OTHER NEARBY
LOCATIONS...FOLLOWED BY RAIN LIKELIHOOD SATURDAY NIGHT AND THE
PATTERN BEHIND THE COLD FRONT.
WHILE THE UPPER AND MID-LEVEL WIND FLOW REMAINS NORTHWESTERLY...THE
AIR MASS IS BECOMING MORE PACIFIC ORIGIN THAN MODIFIED ARCTIC PER
UPPER AIR ANALYSES. THE HIGH PRESSURE RIDGE IS CENTERED NEAR THE
MISSISSIPPI RIVER EARLY THIS MORNING AND WILL MOVE OVER THE AREA
BY AFTERNOON AND PERSIST THROUGH LATE IN THE DAY FRIDAY. THIS
LIGHT PRESSURE GRADIENT FORCE ALONG WITH MORE SUNSHINE TOWARD
WARMING TEMPERATURES OVER LAND WILL CERTAINLY FOSTER LAKE BREEZE
DEVELOPMENT. IT IS LIKELY THIS WILL BE EARLIER THAN THE PAST TWO
DAYS GIVEN THE SETUP. THIS IS SUPPORTED BY THE HRRR WHICH STARTS
THE LAKE BREEZE NEAR 11 AM. HAVE CONTINUED TO REFLECT A DROPPING
AND THEN STABILIZING TEMPERATURE TREND NEAR THE LAKE SHORE...WITH
AFTERNOON READINGS LIKELY IN THE UPPER AND MAYBE EVEN MID 30S. AS
FOR THE REMAINDER OF THE FORECAST AREA...SOME CU IS POSSIBLE
NAMELY OVER NE IL AND NW IN AS THE LAST OF THE COLD AIR ALOFT
SCOOTS OUT. THE WARM AIR ADVECTION IN ITS PLACE AND FURTHER MIXING
SHOULD ALLOW FOR WIDESPREAD HIGHS IN THE MID 40S...BASICALLY THE
HIGHS OF YESTERDAY PLUS THREE TO FOUR DEGREES.
ANOTHER SHARP UPPER TROUGH WILL DIG INTO THE GREAT LAKES REGION BY
EARLY NEXT WEEK...WITH A FIRST SEEMINGLY WELL-DEFINED SHORT WAVE
AND SURFACE TROUGH ADVANCING THROUGH THE AREA SATURDAY NIGHT. THE
NAM...GFS...AND EC ALL AGREE ON A SURFACE LOW RESPONSE FROM
NORTHERN MO THROUGH OUR AREA DURING SATURDAY NIGHT...WITH A
FOCUSED MOIST ADVECTION AND CONVERGENCE AREA MOVING ACROSS WITHIN
FAIRLY GOOD UPPER FORCING. HAVE CONTINUED TO INCH UP POPS FOR
SATURDAY EVENING. SOME GUIDANCE INCLUDING THE EC AND NAM ALREADY
SPREAD RAIN INTO THE WESTERN AND SOUTHWESTERN FORECAST AREA AS
EARLY AS MID TO LATE AFTERNOON AND HAVE CONTINUED TO ACCOUNT FOR
THAT. MORE MEMBERS OF THE GEFS SHOW POTENTIAL FOR OVER A QUARTER
OF AN INCH BUT VERY FEW INCLUDING IN THE SREF GIVE OVER ONE HALF
AN INCH.
TEMPERATURES IN ADVANCE OF THE FRONT LOOK TO EXCEED 50 AREA-WIDE
ON SATURDAY WITH A MILD NIGHT AS THE CLOUDS AND THE BOUNDARY PASS.
SUNDAY TEMPERATURES IN THE UPPER 40S TO MID 50S ARE LOOKING MORE
CONFIDENT THANKS TO A HIGH STARTING POINT AND THE FIRST COLD FRONT
NOT BRINGING MUCH OF A COLD AIR DUMP. THAT WILL COME SUNDAY NIGHT
WITH A COOL PATTERN TO START NEXT WEEK AS 850 MB TEMPERATURES DROP
ONCE AGAIN TO ONE AND A HALF STANDARD DEVIATIONS BELOW NORMAL /PER
GEFS AND EC FORECASTS/. HAVE ADAPTED LOCAL CLIMATOLOGICAL RESEARCH
FOR THESE 850MB TEMPERATURES OF -10C INTO THE FORECAST...WHICH
INDICATE GOOD POTENTIAL FOR HIGHS TO REMAIN AT OR BELOW 40 IN
CHICAGO...WHICH ALREADY LOOKED PRETTY GOOD IN THE FORECAST. ONE
THING ABOUT NEXT WEEK COMPARED TO THE COOL TEMPERATURES OF EARLIER
THIS WEEK IS THAT WHILE UNDER CYCLONIC FLOW AGAIN WE WILL BE LESS
ENTRENCHED AND THUS LESS FAVORED FOR CONTINUOUS STARTOCU. WE
SHOULD HAVE SOME DURING THE DAYS BUT WE ARE FURTHER FROM THE
CYCLONIC CENTER WHICH WILL BE UP IN QUEBEC ALREADY BY MONDAY
AFTERNOON. NO SIGN OF A MAJOR WARM-UP BUT A GRADUAL ONE LATE NEXT
WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE HAS DEVELOPED NEAR THE LAKE SHORE. POTENTIAL FOR IT
TO MOVE INLAND FAR ENOUGH THIS AFTERNOON TO PASS THROUGH MDW
AND ORD.
PAW
//DISCUSSION...UPDATED 18Z...
A HIGH PRESSURE RIDGE DOMINATES NORTHERN ILLINOIS AND NORTHWEST
INDIANA WEATHER TODAY. FEW CLOUDS AND LIGHT WINDS. A LAKE BREEZE
HAS DEVELOPED AND PUSHED PAST GYY ALREADY. THE QUESTION FOR THE
AFTERNOON IS WHETHER IT WILL MOVE INLAND FAR ENOUGH TO PASS
THROUGH MDW AND ORD. WITH THE RIDGE AXIS JUST TO THE WEST OF THE
TERMINALS AND GOOD HEATING IT SEEMS LIKELY THAT ORD AND MDW WILL
SEE WINDS GO TO THE NORTHEAST BY LATE THIS AFTERNOON.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE THAT LAKE BREEZE WILL PASS MDW OR ORD...AND
TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT AND SATURDAY...VFR.
* SATURDAY NIGHT....MVFR. RAIN LIKELY.
* SUNDAY...MVFR EARLY...THEN VFR. W-WNW WINDS GUSTING 20-25KT LATE
MORNING THROUGH AFTERNOON.
* SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR.
TRS
&&
.MARINE...
230 PM CDT
BROAD RIDGE OF HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER
OVER THE ENTIRE GREAT LAKES REGION...STRETCHING FROM HUDSON BAY
SOUTH TO THE GULF OF MEXICO. THIS RIDGE WILL CONSOLIDATE SLIGHTLY
AND BECOME FOCUSED OVERNIGHT ACROSS THE GREAT LAKES AND TENNESSEE
VALLEY. GUIDANCE CONTINUES TO SUGGEST THE RIDGE WILL REMAIN
OVERHEAD THROUGH SATURDAY MORNING...DRIFTING EAST BY SATURDAY
NIGHT. THE FOCUS THEN TURNS TOWARDS A DEVELOPING LOW PRESSURE
SYSTEM THAT WILL QUICKLY SLIDE NORTHEAST TOWARDS THE UPPER MIDWEST
AND NORTHERN GREAT LAKES REGION...WITH A TIGHTENING WIND GRADIENT.
IT APPEARS THAT WITH THE INCREASING SOUTHERLY WINDS SATURDAY NIGHT
INTO SUNDAY THAT WAVES WILL BE BUILDING OVER THE OPEN WATERS OF
LAKE MICHIGAN. WITH THE APPROACHING COLD FRONT LATE IN THE
WEEKEND...AND GUSTY WINDS...THE POTENTIAL FOR GALES STILL LOOKS
POSSIBLE OVERNIGHT SUNDA INTO MONDAY MORNING. THEN HIGH PRESSURE
BUILDS INTO THE REGION YET AGAIN FROM CENTRAL CANADA...WITH A
PERIOD OF NORTHWEST WINDS BUILDING WAVES FOR THE SOUTHERN HALF OF
LAKE MICHIGAN EARLY NEXT WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1241 PM CDT THU MAR 28 2013
.DISCUSSION...
332 AM CDT
WHILE THE FORECAST IS GENERALLY QUIET...THERE ARE SOME CHALLENGES.
THESE CONTINUE TO BE TEMPERATURES AND WEIGHING THE EFFECTS OF THE
LAKE BREEZE FOR DOWNTOWN CHICAGO AND OTHER NEARBY
LOCATIONS...FOLLOWED BY RAIN LIKELIHOOD SATURDAY NIGHT AND THE
PATTERN BEHIND THE COLD FRONT.
WHILE THE UPPER AND MID-LEVEL WIND FLOW REMAINS NORTHWESTERLY...THE
AIR MASS IS BECOMING MORE PACIFIC ORIGIN THAN MODIFIED ARCTIC PER
UPPER AIR ANALYSES. THE HIGH PRESSURE RIDGE IS CENTERED NEAR THE
MISSISSIPPI RIVER EARLY THIS MORNING AND WILL MOVE OVER THE AREA
BY AFTERNOON AND PERSIST THROUGH LATE IN THE DAY FRIDAY. THIS
LIGHT PRESSURE GRADIENT FORCE ALONG WITH MORE SUNSHINE TOWARD
WARMING TEMPERATURES OVER LAND WILL CERTAINLY FOSTER LAKE BREEZE
DEVELOPMENT. IT IS LIKELY THIS WILL BE EARLIER THAN THE PAST TWO
DAYS GIVEN THE SETUP. THIS IS SUPPORTED BY THE HRRR WHICH STARTS
THE LAKE BREEZE NEAR 11 AM. HAVE CONTINUED TO REFLECT A DROPPING
AND THEN STABILIZING TEMPERATURE TREND NEAR THE LAKE SHORE...WITH
AFTERNOON READINGS LIKELY IN THE UPPER AND MAYBE EVEN MID 30S. AS
FOR THE REMAINDER OF THE FORECAST AREA...SOME CU IS POSSIBLE
NAMELY OVER NE IL AND NW IN AS THE LAST OF THE COLD AIR ALOFT
SCOOTS OUT. THE WARM AIR ADVECTION IN ITS PLACE AND FURTHER MIXING
SHOULD ALLOW FOR WIDESPREAD HIGHS IN THE MID 40S...BASICALLY THE
HIGHS OF YESTERDAY PLUS THREE TO FOUR DEGREES.
ANOTHER SHARP UPPER TROUGH WILL DIG INTO THE GREAT LAKES REGION BY
EARLY NEXT WEEK...WITH A FIRST SEEMINGLY WELL-DEFINED SHORT WAVE
AND SURFACE TROUGH ADVANCING THROUGH THE AREA SATURDAY NIGHT. THE
NAM...GFS...AND EC ALL AGREE ON A SURFACE LOW RESPONSE FROM
NORTHERN MO THROUGH OUR AREA DURING SATURDAY NIGHT...WITH A
FOCUSED MOIST ADVECTION AND CONVERGENCE AREA MOVING ACROSS WITHIN
FAIRLY GOOD UPPER FORCING. HAVE CONTINUED TO INCH UP POPS FOR
SATURDAY EVENING. SOME GUIDANCE INCLUDING THE EC AND NAM ALREADY
SPREAD RAIN INTO THE WESTERN AND SOUTHWESTERN FORECAST AREA AS
EARLY AS MID TO LATE AFTERNOON AND HAVE CONTINUED TO ACCOUNT FOR
THAT. MORE MEMBERS OF THE GEFS SHOW POTENTIAL FOR OVER A QUARTER
OF AN INCH BUT VERY FEW INCLUDING IN THE SREF GIVE OVER ONE HALF
AN INCH.
TEMPERATURES IN ADVANCE OF THE FRONT LOOK TO EXCEED 50 AREA-WIDE
ON SATURDAY WITH A MILD NIGHT AS THE CLOUDS AND THE BOUNDARY PASS.
SUNDAY TEMPERATURES IN THE UPPER 40S TO MID 50S ARE LOOKING MORE
CONFIDENT THANKS TO A HIGH STARTING POINT AND THE FIRST COLD FRONT
NOT BRINGING MUCH OF A COLD AIR DUMP. THAT WILL COME SUNDAY NIGHT
WITH A COOL PATTERN TO START NEXT WEEK AS 850 MB TEMPERATURES DROP
ONCE AGAIN TO ONE AND A HALF STANDARD DEVIATIONS BELOW NORMAL /PER
GEFS AND EC FORECASTS/. HAVE ADAPTED LOCAL CLIMATOLOGICAL RESEARCH
FOR THESE 850MB TEMPERATURES OF -10C INTO THE FORECAST...WHICH
INDICATE GOOD POTENTIAL FOR HIGHS TO REMAIN AT OR BELOW 40 IN
CHICAGO...WHICH ALREADY LOOKED PRETTY GOOD IN THE FORECAST. ONE
THING ABOUT NEXT WEEK COMPARED TO THE COOL TEMPERATURES OF EARLIER
THIS WEEK IS THAT WHILE UNDER CYCLONIC FLOW AGAIN WE WILL BE LESS
ENTRENCHED AND THUS LESS FAVORED FOR CONTINUOUS STARTOCU. WE
SHOULD HAVE SOME DURING THE DAYS BUT WE ARE FURTHER FROM THE
CYCLONIC CENTER WHICH WILL BE UP IN QUEBEC ALREADY BY MONDAY
AFTERNOON. NO SIGN OF A MAJOR WARM-UP BUT A GRADUAL ONE LATE NEXT
WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE HAS DEVELOPED NEAR THE LAKE SHORE. POTENTIAL FOR IT
TO MOVE INLAND FAR ENOUGH THIS AFTERNOON TO PASS THROUGH MDW
AND ORD.
PAW
//DISCUSSION...UPDATED 18Z...
A HIGH PRESSURE RIDGE DOMINATES NORTHERN ILLINOIS AND NORTHWEST
INDIANA WEATHER TODAY. FEW CLOUDS AND LIGHT WINDS. A LAKE BREEZE
HAS DEVELOPED AND PUSHED PAST GYY ALREADY. THE QUESTION FOR THE
AFTERNOON IS WHETHER IT WILL MOVE INLAND FAR ENOUGH TO PASS
THROUGH MDW AND ORD. WITH THE RIDGE AXIS JUST TO THE WEST OF THE
TERMINALS AND GOOD HEATING IT SEEMS LIKELY THAT ORD AND MDW WILL
SEE WINDS GO TO THE NORTHEAST BY LATE THIS AFTERNOON.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE THAT LAKE BREEZE WILL PASS MDW OR ORD...AND
TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT AND SATURDAY...VFR.
* SATURDAY NIGHT....MVFR. RAIN LIKELY.
* SUNDAY...MVFR EARLY...THEN VFR. W-WNW WINDS GUSTING 20-25KT LATE
MORNING THROUGH AFTERNOON.
* SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR.
TRS
&&
.MARINE...
342 AM CDT
A HIGH PRESSURE RIDGE EXTENDING FROM HUDSON BAY S ACROSS THE
UPPER MIDWEST AND MID AND LOWER MS VALLEY TO THE GULF COAST HAS
BEEN MOVING VERY SLOWLY EASTWARD THE LAST FEW DAYS AND WILL
CONTINUE THIS VERY SLOW APPROACH EASTWARD TODAY...WITH THE RIDGE
AXIS FINALLY MOVING OVER LAKE MI TONIGHT. WITH THE RIDGE CLOSE BY
AND EVENTUALLY OVER THE LAKE ONLY LIGHT TO GENTLE BREEZES WILL BE
EXPERIENCED FROM MIDDAY TODAY THROUGH FRIDAY.
WITH THE RIDGE THEN MOVING FURTHER E TO THE LOWER GREAT LAKES AND
THE UPPER OH FRI NIGHT...AND LOW PRESSURE MOVING E ACROSS
NORTHERN MANITOBA TO NORTHERN ONTARIO PUSHING A COLD FRONT
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS WINDS WILL RESULT IN
S TO SW WINDS ESTABLISHING OVERNIGHT FRIDAY AND GRADUALLY
INCREASING TO FRESH SOUTH BREEZES BY SAT AFTERNOON.
THE STRONG COLD FRONT TRAILING SW FROM THE CANADIAN LOW WILL MOVE
ACROSS LAKE MI SUN AND SUN NIGHT LEADING SHIFTING WINDS TO OUT OF
THE W AND NW AND AN INCREASE TO NEAR GALE FORCE OVERNIGHT SUNDAY.
THESE NEAR GALE WINDS WINDS CONTINUE INTO MONDAY AFTERNOON. THERE
IS THE POTENTIAL FOR LOW END GALES ON THE LAKE AFTER THE COLD
FRONT PASSES INTO THE CENTRAL GREAT LAKES LATE SUN NIGHT AND MON
BUT THIS POTENTIAL LOOKS TO BE SMALL AT THIS TIME.
BEHIND THE COLD FRONT HIGH PRESSURE BUILDS FROM SASKATCHEWAN TO
THE CENTRAL PLAINS SUN AND MON. AS THE HIGH MOVES FURTHER TO THE
E ACROSS THE PLAINS NW WINDS ON LAKE MI WILL BEGIN TO GRADUALLY
DIMINISH LATE MONDAY NIGHT AND TUESDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1202 PM CDT THU MAR 28 2013
.DISCUSSION...
ISSUED 1002 AM CDT THU MAR 28 2013
HIGH PRESSURE AXIS CURRENTLY DRAPED NORTHWEST-SOUTHEAST ACROSS THE
FORECAST AREA. SOME WARM AIR ADVECTION CONTINUES TO CREATE
CLOUDINESS ACROSS MISSOURI...AND SATELLITE AND LATEST RAP MODEL
ANALYSIS TRACKS THIS LARGELY SOUTHEAST THROUGH THE AFTERNOON.
MAIN CONCERN IS WITH TEMPERATURES TODAY. VISIBLE SATELLITE IMAGERY
SHOWING LOCATIONS NORTHWEST OF A HAVANA TO LACON LINE...AS WELL AS
SOUTH OF AN EFFINGHAM TO PARIS LINE...WITH LITTLE OR NO SNOW
COVER. THESE AREAS WILL BE THE MILDER LOCATIONS TODAY. HAVE MADE
SOME MINOR UPWARD ADJUSTMENTS TO TEMPERATURES IN THE NORTHWEST
CORNER OF THE CWA...BUT LEFT MUCH OF THE REMAINDER OF THE AREA
ALONE FOR NOW.
GEELHART
&&
.AVIATION...
ISSUED 1201 PM CDT THU MAR 28 2013
MAIN CONCERN IS WITH PERIOD FROM 06-15Z...AS WEAK UPPER WAVE
PASSES TO OUR SOUTHWEST. CURRENTLY THINK THAT THE CENTRAL ILLINOIS
TAF SITES WILL REMAIN DRY...HOWEVER CLOUDS WILL GRADUALLY MOVE IN
AND LOWER OVERNIGHT. GFS SOUNDINGS KEEP CEILINGS AT LEAST 4000
FEET LATE TONIGHT INTO FRIDAY MORNING. WITH ABUNDANT SUNSHINE AND
MORE SNOW MELT TODAY...THE ADDED MOISTURE MAY PRODUCE SOME LIGHT
FOG/HAZE CONDITIONS SIMILAR TO THIS MORNING...BUT MORE EXTENSIVE
CLOUD COVER SHOULD KEEP IT FROM GETTING OUT OF HAND. WILL ADD
SOME TEMPO VISIBILITIES AROUND 5SM AT MOST SITES EXCEPT FOR
KPIA...WHERE CURRENT SNOW DEPTH IS NOT AS SIGNIFICANT.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 316 AM CDT THU MAR 28 2013
SHORT TERM...TODAY THROUGH FRIDAY NIGHT
HIGH PRESSURE IN FIRM CONTROL OF THE WEATHER PATTERN ACROSS THE
AREA THIS MORNING PRODUCING CLEAR AND CALM CONDITIONS. THE RIDGE
AXIS IS PROGGED TO MOVE LITTLE THROUGH THIS AFTERNOON AND WILL
PROVIDE A SUNNY DAY WITH TEMPS A FEW DEGREES WARMER THAN YESTERDAY
DUE TO AIR MASS MODIFICATION AND MORE BARE GROUND FOR THE STRONG
LATE MARCH SUN TO WORK ON. TONIGHT...ELEVATED WARM AIR ADVECTION
WILL BE TAKING PLACE TO THE NORTH OF A WARM FRONT WHICH WILL BE
STRETCHED WEST-EAST OVER THE SOUTHERN THIRD OF MISSOURI. FAIRLY
STRONG ISENTROPIC LIFT NOTED ON 290K SFC 06-12Z FRIDAY OVER ERN
MO/SW IL COINCIDENT WITH WEAK DPVA OFF A SHORTWAVE RIDING
SOUTHEAST FROM IA SHOULD BE SUFFICIENT TO DEVELOP SCATTERED
SHOWERS. QUESTIONS REMAIN HOW FAR NORTHEAST THIS ACTIVITY WILL
DEVELOP INTO SUBSIDENCE REGION OF LINGERING RIDGE AND DRIER AIR
OVER CENTRAL IL...BUT TRENDS OVER THE PAST 24 HOURS SUGGEST
INTRODUCING LOW CHANCE POPS LATE TONIGHT AND FRIDAY MORNING SOUTH
OF I-70. NAM FORECAST SOUNDINGS SHOW TEMPS ABOVE 0 C IN THE LOWEST
2500 FT SO ANY PRECIP SHOULD FALL AS RAIN. QUIET WEATHER THEN
EXPECTED FRIDAY AFTERNOON AND NIGHT AHEAD OF THE NEXT WEATHER
SYSTEM WHICH WILL BRING MORE WIDESPREAD RAINS THIS WEEKEND.
LONG TERM...SATURDAY THROUGH WEDNESDAY
COLD FRONT STILL SLATED TO SHIFT ACROSS THE CWA LATE
SATURDAY/EARLY SUNDAY BRINGING A GOOD CHANCE OF RAIN. AHEAD OF THE
FRONT...SOUTHERLY SURFACE FLOW SHOULD ALLOW READINGS TO GET UP
INTO THE MID/UPPER 50S. CLOUDS WILL BE ON THE INCREASE FROM THE NW
BY AFTERNOON AND HAVE CHANCE POPS NW OF THE IL RIVER. GOOD MODEL
AGREEMENT ON FRONTAL TIMING WHICH BRINGS HIGHEST RAIN COVERAGE
OVERNIGHT. PROGRESSIVE FRONT SO MAINLY QUARTER TO HALF INCH
TOTALS. THE RAIN SHOULD PUSH INTO INDIANA BY EARLY MORNING...AND
WITH THE MAIN COLD SURGE STAYING NORTH THROUGH AFTERNOON SUNDAY
NOW LOOKS LIKE A DECENT DAY WITH HIGHS GETTING BACK UP INTO THE
50S. SECONDARY COLD FRONT HITS SUNDAY EVENING BRINGING ANOTHER
BATCH OF MODIFIED ARCTIC AIR...WITH 850 MB TEMPS CRASHING TO -6 TO
-10 C ON MONDAY. AN IMPULSE RIDING EAST FROM THE PLAINS WILL
LIKELY SPREAD PRECIP NORTH OVER THE SOUTHERN FRINGE OF THE COLDER
AIR MASS...AFFECTING PARTS OF THE MIDWEST AND OHIO VALLEY ON
MONDAY. WITH STRENGTH OF THE HIGH BUILDING SOUTH THROUGH THE
PLAINS FEEL MOST OF THIS ACTIVITY WILL BE SUPPRESSED SOUTH OF THE
LOCAL AREA...HOWEVER MODEL CONSENSUS KEEPS LOW CHANCE POPS OVER
THE SOUTHERN HALF OF THE CWA SUNDAY NIGHT AND MONDAY. IF ACTIVITY
DOES MATERIALIZE THIS FAR NORTH PRECIP TYPE WOULD BE IN QUESTION
GIVEN MARGINAL SFC TEMPS. LATE SEASON ARCTIC HIGH WILL THEN
DOMINATE THE WEATHER PATTERN ACROSS THE AREA THROUGH MID-WEEK
PRODUCING DRY AND COOL CONDITIONS.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1105 AM CDT THU MAR 28 2013
.DISCUSSION...
332 AM CDT
WHILE THE FORECAST IS GENERALLY QUIET...THERE ARE SOME CHALLENGES.
THESE CONTINUE TO BE TEMPERATURES AND WEIGHING THE EFFECTS OF THE
LAKE BREEZE FOR DOWNTOWN CHICAGO AND OTHER NEARBY
LOCATIONS...FOLLOWED BY RAIN LIKELIHOOD SATURDAY NIGHT AND THE
PATTERN BEHIND THE COLD FRONT.
WHILE THE UPPER AND MID-LEVEL WIND FLOW REMAINS NORTHWESTERLY...THE
AIR MASS IS BECOMING MORE PACIFIC ORIGIN THAN MODIFIED ARCTIC PER
UPPER AIR ANALYSES. THE HIGH PRESSURE RIDGE IS CENTERED NEAR THE
MISSISSIPPI RIVER EARLY THIS MORNING AND WILL MOVE OVER THE AREA
BY AFTERNOON AND PERSIST THROUGH LATE IN THE DAY FRIDAY. THIS
LIGHT PRESSURE GRADIENT FORCE ALONG WITH MORE SUNSHINE TOWARD
WARMING TEMPERATURES OVER LAND WILL CERTAINLY FOSTER LAKE BREEZE
DEVELOPMENT. IT IS LIKELY THIS WILL BE EARLIER THAN THE PAST TWO
DAYS GIVEN THE SETUP. THIS IS SUPPORTED BY THE HRRR WHICH STARTS
THE LAKE BREEZE NEAR 11 AM. HAVE CONTINUED TO REFLECT A DROPPING
AND THEN STABILIZING TEMPERATURE TREND NEAR THE LAKE SHORE...WITH
AFTERNOON READINGS LIKELY IN THE UPPER AND MAYBE EVEN MID 30S. AS
FOR THE REMAINDER OF THE FORECAST AREA...SOME CU IS POSSIBLE
NAMELY OVER NE IL AND NW IN AS THE LAST OF THE COLD AIR ALOFT
SCOOTS OUT. THE WARM AIR ADVECTION IN ITS PLACE AND FURTHER MIXING
SHOULD ALLOW FOR WIDESPREAD HIGHS IN THE MID 40S...BASICALLY THE
HIGHS OF YESTERDAY PLUS THREE TO FOUR DEGREES.
ANOTHER SHARP UPPER TROUGH WILL DIG INTO THE GREAT LAKES REGION BY
EARLY NEXT WEEK...WITH A FIRST SEEMINGLY WELL-DEFINED SHORT WAVE
AND SURFACE TROUGH ADVANCING THROUGH THE AREA SATURDAY NIGHT. THE
NAM...GFS...AND EC ALL AGREE ON A SURFACE LOW RESPONSE FROM
NORTHERN MO THROUGH OUR AREA DURING SATURDAY NIGHT...WITH A
FOCUSED MOIST ADVECTION AND CONVERGENCE AREA MOVING ACROSS WITHIN
FAIRLY GOOD UPPER FORCING. HAVE CONTINUED TO INCH UP POPS FOR
SATURDAY EVENING. SOME GUIDANCE INCLUDING THE EC AND NAM ALREADY
SPREAD RAIN INTO THE WESTERN AND SOUTHWESTERN FORECAST AREA AS
EARLY AS MID TO LATE AFTERNOON AND HAVE CONTINUED TO ACCOUNT FOR
THAT. MORE MEMBERS OF THE GEFS SHOW POTENTIAL FOR OVER A QUARTER
OF AN INCH BUT VERY FEW INCLUDING IN THE SREF GIVE OVER ONE HALF
AN INCH.
TEMPERATURES IN ADVANCE OF THE FRONT LOOK TO EXCEED 50 AREA-WIDE
ON SATURDAY WITH A MILD NIGHT AS THE CLOUDS AND THE BOUNDARY PASS.
SUNDAY TEMPERATURES IN THE UPPER 40S TO MID 50S ARE LOOKING MORE
CONFIDENT THANKS TO A HIGH STARTING POINT AND THE FIRST COLD FRONT
NOT BRINGING MUCH OF A COLD AIR DUMP. THAT WILL COME SUNDAY NIGHT
WITH A COOL PATTERN TO START NEXT WEEK AS 850 MB TEMPERATURES DROP
ONCE AGAIN TO ONE AND A HALF STANDARD DEVIATIONS BELOW NORMAL /PER
GEFS AND EC FORECASTS/. HAVE ADAPTED LOCAL CLIMATOLOGICAL RESEARCH
FOR THESE 850MB TEMPERATURES OF -10C INTO THE FORECAST...WHICH
INDICATE GOOD POTENTIAL FOR HIGHS TO REMAIN AT OR BELOW 40 IN
CHICAGO...WHICH ALREADY LOOKED PRETTY GOOD IN THE FORECAST. ONE
THING ABOUT NEXT WEEK COMPARED TO THE COOL TEMPERATURES OF EARLIER
THIS WEEK IS THAT WHILE UNDER CYCLONIC FLOW AGAIN WE WILL BE LESS
ENTRENCHED AND THUS LESS FAVORED FOR CONTINUOUS STARTOCU. WE
SHOULD HAVE SOME DURING THE DAYS BUT WE ARE FURTHER FROM THE
CYCLONIC CENTER WHICH WILL BE UP IN QUEBEC ALREADY BY MONDAY
AFTERNOON. NO SIGN OF A MAJOR WARM-UP BUT A GRADUAL ONE LATE NEXT
WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE HAS DEVELOPED NEAR THE LAKE SHORE. THE QUESTION IS
WHETHER IT WILL MOVE INLAND FAR ENOUGH THIS AFTERNOON TO PASS
THROUGH MDW AND ORD.
PAW
//DISCUSSION...UPDATED 12Z...
A RIDGE OF HIGH PRESSURE EXTENDING FROM WESTERN HUDSON BAY SOUTH
ACROSS THE UPPER MIDWEST AND MID AND LOWER MS VALLEY TO THE GULF
OF MEX HAS BEEN MOVING VERY SLOWLY E FROM THE PLAINS TOWARD THE
LOCAL AREA OVER THE LAST FEW DAYS. WITH ITS CONTINUED GRADUAL
DRIFT TO THE E THE RIDGE AXIS IS FINALLY PROGGED TO MOVE OVER THE
LOCAL AREA DURING THIS AFTERNOON AND EVENING.
WITH THE RIDGE AXIS VERY NEAR OR OVERHEAD THIS AFTERNOON AND
EVENING THE CURRENT LIGHT NW TO NNW LOW LEVEL FLOW WILL WEAKEN
EVEN FURTHER AND BASICALLY BE NIL BY 00Z. WHILE A VERY WEAK LAKE
BREEZE DID DEVELOP WED IT DID NOT MAKE IT MORE THAN A MILE OR TWO
INLAND. WITH AFTERNOON TEMPERATURES FORECAST SOME 3 TO 5 DEG F
WARMER THAN THOSE REACHED WED AND VERY LITTLE LOW LEVEL FLOW TO
IMPEDE A FURTHER INLAND ADVANCE OF THE LAKE BREEZE DO EXPECT IT
TO REACH MDW AROUND 22Z AND MDW AROUND 23Z SHIFTING LIGHT WINDS
FROM OUT OF THE NNW AND N TO OUT OF THE ENE AND NE.
WITH SUNSET AND LOSS OF HEATING THE BOUNDARY WILL WASH OUT
LEAVING WINDS LIGHT VARIABLE OR NIL WITH THE RIDGE AXIS BASICALLY
STILL OVERHEAD AS IT IS NOT PROGGED TO REACH THE IL LAKE SHORE TIL
EARLY FRI MORNING.
SURFACE HEATING AND MARGINAL LOW LEVEL MOISTURE MAY GIVE RISE
TO FEW-SCT STRATOCU MID MORNING THROUGH EARLY AFTERNOON THEN
WARMING IN THE 850-800HPA LAYER CREATES TOO LARGE OF A DEW
POINT DEPRESSION TO SUPPORT ANY DIURNAL CLOUDS. OTHERWISE ONLY
FEW-SCT CIRRUS RIDING OVER A BROAD WESTERN UPPER RIDGE REACHING
THE LOCAL AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* LOW TO MEDIUM CONFIDENCE THAT LAKE BREEZE WILL PASS MDW OR
ORD...AND TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT AND SATURDAY...VFR.
* SATURDAY NIGHT....MVFR. RAIN LIKELY.
* SUNDAY...MVFR EARLY...THEN VFR. W-WNW WINDS GUSTING 20-25KT LATE
MORNING THROUGH AFTERNOON.
* SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR.
TRS
&&
.MARINE...
342 AM CDT
A HIGH PRESSURE RIDGE EXTENDING FROM HUDSON BAY S ACROSS THE
UPPER MIDWEST AND MID AND LOWER MS VALLEY TO THE GULF COAST HAS
BEEN MOVING VERY SLOWLY EASTWARD THE LAST FEW DAYS AND WILL
CONTINUE THIS VERY SLOW APPROACH EASTWARD TODAY...WITH THE RIDGE
AXIS FINALLY MOVING OVER LAKE MI TONIGHT. WITH THE RIDGE CLOSE BY
AND EVENTUALLY OVER THE LAKE ONLY LIGHT TO GENTLE BREEZES WILL BE
EXPERIENCED FROM MIDDAY TODAY THROUGH FRIDAY.
WITH THE RIDGE THEN MOVING FURTHER E TO THE LOWER GREAT LAKES AND
THE UPPER OH FRI NIGHT...AND LOW PRESSURE MOVING E ACROSS
NORTHERN MANITOBA TO NORTHERN ONTARIO PUSHING A COLD FRONT
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS WINDS WILL RESULT IN
S TO SW WINDS ESTABLISHING OVERNIGHT FRIDAY AND GRADUALLY
INCREASING TO FRESH SOUTH BREEZES BY SAT AFTERNOON.
THE STRONG COLD FRONT TRAILING SW FROM THE CANADIAN LOW WILL MOVE
ACROSS LAKE MI SUN AND SUN NIGHT LEADING SHIFTING WINDS TO OUT OF
THE W AND NW AND AN INCREASE TO NEAR GALE FORCE OVERNIGHT SUNDAY.
THESE NEAR GALE WINDS WINDS CONTINUE INTO MONDAY AFTERNOON. THERE
IS THE POTENTIAL FOR LOW END GALES ON THE LAKE AFTER THE COLD
FRONT PASSES INTO THE CENTRAL GREAT LAKES LATE SUN NIGHT AND MON
BUT THIS POTENTIAL LOOKS TO BE SMALL AT THIS TIME.
BEHIND THE COLD FRONT HIGH PRESSURE BUILDS FROM SASKATCHEWAN TO
THE CENTRAL PLAINS SUN AND MON. AS THE HIGH MOVES FURTHER TO THE
E ACROSS THE PLAINS NW WINDS ON LAKE MI WILL BEGIN TO GRADUALLY
DIMINISH LATE MONDAY NIGHT AND TUESDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1245 PM CDT THU MAR 28 2013
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 1030 PM CDT WED MAR 27 2013
THE 28.00Z 250 HPA RAOB MAP SHOWED WESTERLY TO NORTHWESTERLY FLOW ACROSS
MUCH OF THE COUNTRY. WIND MAGNITUDES WERE ~50 KT OVER THE PACIFIC NORTHWEST,
~85 KT ACROSS THE KDDC REGION, AND THE STRONGEST WAS ~125+ KT ACROSS
FLORIDA. AT 500 HPA, A DRY NORTHWESTERLY FLOW WAS OBSERVED ACROSS THE
GREAT PLAINS. TEMPERATURES VARIED FROM -10 DEG C AT KBRO TO -24 DEG
C AT KBIS. THE MID LEVEL COLD POOL WITH TEMPERATURES IN THE -30 DEG
C TO -33 DEG C RANGE WAS WELL TO THE NORTHEAST OF SOUTHWEST KANSAS.
AT 700 HPA, THERE WAS A WEAK BAROCLINIC BOUNDARY BETWEEN KDDC (-1 DEG
C) AND KAMA (4 DEG C). AT 850 HPA, A TEMPERATURE GRADIENT CONTINUED
FROM KDDC (7 DEG C) TO KAMA (16 DEG C). SOME LOW LEVEL MOISTURE ADVECTION
WAS NOTED ACROSS FAR SOUTH TEXAS. AT THE SFC, A STATIONARY FRONT WAS
ANALYZED ACROSS THE NORTHERN HIGH PLAINS. THIS BOUNDARY TURNED INTO
A COLD FRONT ACROSS THE SOUTHERN HIGH PLAINS. RELATIVELY HIGHER DEWPOINTS
OF 50+ DEG F WERE CONFINED TO COASTAL SOUTH TEXAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CDT THU MAR 28 2013
THIS MORNING:
IMMEDIATE SHORT TERM CONCERN IS PATCHY FOG ACROSS CENTRAL KANSAS THIS
MORNING. A NORTHEASTERLY UPSLOPE FLOW ALONG WITH SURFACE PRESSURE CONDENSATION
DEFICITS NEAR 0 HPA AND IN COMBINATION WITH BUFR/BUFKIT FORECAST SOUNDING
SPELL THE CONCERN FOR PATCHY FOG NORTHEAST OF A LINE FROM ST. JOHN TO
PENDENNIS. HRRR IS QUITE AGGRESSIVE WITH THE FOG AND SUGGESTING DENSE
FOG (LESS THAN/EQUAL TO QUARTER OF A MILE VISIBILITY) BUT FEEL THIS
MIGHT BE OVERDONE.
TODAY:
A WEAK WARM AIR ADVECTION PATTERN IS EXPECTED TODAY AS A RESULT OF 500
HPA GEOPOTENTIAL HEIGHT INCREASES AND WITH WINDS BECOMING EAST-SOUTHEASTERLY
TONIGHT AS WEAK LEE SURFACE TROUGHING DEEPENS ACROSS COLORADO. FORECAST
SOUNDINGS SHOW A MIXED PROFILE GENERALLY UP TO 750 HPA, WHICH SUPPORTS
MIX DOWN TEMPERATURES IN THE 60S DEG F. PLENTY OF MID TO HIGH LEVEL
CLOUDS IS EXPECTED TODAY AS WATER VAPOR IMAGERY SHOWS MOISTURE ADVECTION
FROM THE ROCKIES AND EVENTUALLY OUT ACROSS THE CENTRAL PLAINS. DELETERIOUS
TEMPERATURE IMPACTS ARE NOT EXPECTED FROM THE AFOREMENTIONED CLOUDS.
TONIGHT:
HAVE A SLIGHT CONCERN FOR OVERNIGHT SHOWERS ACROSS SOUTH CENTRAL KANSAS
IN ASSOCIATION WITH CONTINUED WARM AIR ADVECTION AND WEAK LIFT ALONG
A STATIONARY FRONT. 0-10 KM MUCAPE (DONE TO CAPTURE THE ENTIRE ATMOSPHERIC
COLUMN) FROM THE NAM SHOWS VALUES AROUND 500-700 J/KG ACROSS THIS REGION,
SO CANNOT RULE OUT ISOLATED THUNDER. THE BEST THETA-E ADVECTION IS SOUTH
AND EAST OF THE REGION, SO WILL NOT GET CARRIED AWAY WITH PRECIPITATION
PROBABILITIES OTHER THAN THE SLIGHT CATEGORY. OVERNIGHT LOWS WILL BE
WARMER - 40S DEG F - AS A RESULT OF CLOUD COVER, SOUTHERLY WINDS, AND
SLIGHTLY HIGHER DEWPOINTS (PARTICULARLY ACROSS SC KS).
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 402 AM CDT THU MAR 28 2013
WEST NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE CENTRAL HIGH
PLAINS. LOW LEVEL MOISTURE OVER THE SOUTHERN PLAINS WILL BE
ADVECTING NORTHWARD INTO KANSAS THROUGH THE NEXT FEW DAYS. A FRONTAL
BOUNDARY IS PROGGED TO REMAIN NEARLY STATIONARY ACROSS OKLAHOMA AND
THE TEXAS PANHANDLE INTO EASTERN COLORADO. THE LOW LEVEL MOISTURE
WILL RESULT IN INCREASING LOW CLOUDINESS TO SOUTHWEST KANSAS FRIDAY
INTO FRIDAY NIGHT. MODEL SOUNDINGS SHOW INCREASING MID LEVEL
INSTABILITY AS WELL. SOME MID LEVEL WARM ADVECTION COULD SPAWN A FEW
SHOWERS AND THUNDERSTORMS ON FRIDAY. THUNDERSTORMS COULD ALSO
DEVELOP OVER EASTERN COLORADO FRIDAY AFTERNOON AND MOVE INTO FAR
WESTERN KANSAS LATER IN THE DAY. A SHORTWAVE TROUGH MOVING INTO THE
UPPER MIDWEST WILL PUSH ANOTHER COLD FRONT SOUTH ACROSS WESTERN
KANSAS ON SATURDAY. THIS COULD TRIGGER THUNDERSTORMS AGAIN SATURDAY
AFTERNOON. THERE IS SOME POTENTIAL FOR SEVERE THUNDERSTORMS OVER
SOUTH CENTRAL KANSAS AS CAPE AND SHEAR VALUES INCREASE TO AROUND
1000 J/KG AND 30-40 KNOTS, RESPECTIVELY. DRIER CONDITIONS SHOULD
PREVAIL ON SUNDAY BEHIND THE FRONT.
THE MEDIUM RANGE MODELS CONTINUE TO SHOW A STRONG UPPER LEVEL LOW
PRESSURE SYSTEM DIGGING SOUTH OUT OF CANADA INTO THE GREAT LAKES
REGION WITH NEARLY MERIDIONAL FLOW DEVELOPING OVER THE NORTHERN
PLAINS. THIS WILL PUSH A STRONG COLD FRONT SOUTH ACROSS THE CENTRAL
PLAINS SUNDAY NIGHT WITH MUCH COLDER TEMPERATURES WILL BE PUSHING
SOUTH BEHIND THE FRONT. THERE WILL BE CHANCES FOR SHOWERS AND
ISOLATED THUNDERSTORMS WITH THE FRONT. THE RAIN SHOULD MIX WITH OR
CHANGE OVER TO LIGHT SNOW LATE SUNDAY NIGHT INTO MONDAY AS THE
COLDER AIR MOVES IN. HAVE LOWERED HIGH TEMPERATURES ON MONDAY INTO
THE 30S WITH LOW 40S ALONG THE OKLAHOMA BORDER. HIGHS ON TUESDAY
WILL CONTINUE TO BE ON THE COOL SIDE...STAYING MAINLY IN THE 40S.
WARMER WEATHER WILL RETURN TO THE CENTRAL PLAINS BY MID WEEK AS
TEMPERATURES CLIMB BACK INTO THE 50S AND 60S BY WEDNESDAY AND
THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1227 PM CDT THU MAR 28 2013
MODELS FORECASTING INCREASING HIGH AND MID LEVEL CLOUDINESS
TONIGHT AND FRIDAY. WITH LIGHT UPSLOPE AND LLVL MOISTURE ADVECTION
COULD SEE SOME PATCHY FOG DEVELOP TOWARDS SUNRISE, HOWEVER MID
LEVEL CLOUDINESS EXPECTED TO KEEP TEMPERATURES FROM REACHING THE
DEW POINT. GFS/SREF MODELS SHOWS A BETTER CHANCE FOR WIDESPREAD
ADVECTION FOG/LOW STRATUS WITH HIGHER BOUNDARY LAYER DEWPOINTS.
FOR NOW EXPECTING VFR CONDITIONS THROUGH THE PERIOD. MODELS ALSO
HINTING AT SOME POSSIBLE ELEVATED CONVECTION TONIGHT, HOWEVER NO
FORCING SEEMS TO BE AVAILABLE WITH UPPER LEVEL RIDGING/LITTLE TO
NO WARM AIR ADVECTION/SHALLOW BOUNDARY LEVEL MOISTURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 43 65 48 / 10 10 30 20
GCK 64 41 65 46 / 10 10 20 20
EHA 64 42 68 46 / 10 10 20 20
LBL 64 44 67 48 / 10 10 20 20
HYS 62 39 64 47 / 10 10 20 20
P28 65 47 63 51 / 10 20 40 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...KRUSE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1222 PM CDT THU MAR 28 2013
.UPDATE...
ISSUED AT 1024 AM CDT THU MAR 28 2013
NOT MUCH CHANGE IS NEEDED TO GOING FORECAST. HAVE CONFINED SPRINKLES
TO THE FAR SOUTHWEST PART OF THE CWA THROUGH MID AFTERNOON...CLOSE
TO WHERE THERE IS A DIMINISHING BAND OF -SHRA OVER SOUTH CENTRAL
MO. KEPT GOING FORECAST FOR ISOLATED -SHRA OVER THE SOUTHERN CWA
LATE THIS AFTERNOON WHERE RAP IS SHOWING SOME MODEST 925-850MB
MOISTURE CONVERGENCE. STILL EXPECT THE COVERAGE OF -SHRA TO
INCREASE TONIGHT AS LOW LEVEL MOISTURE CONVERGENCE INCREASES UNDER
MODEST ASCENT ASSOCIATED WITH WEAK MID LEVEL VORT MOVING
SOUTHEASTWARD ACROSS THE AREA. DID INCREASE TEMPERATURES A BIT IN
THE FAR NORTHWESTERN CWA WHERE THERE IS SOME MORE SUNSHINE WITH
LITTLE SNOW COVER.
BRITT
&&
.SHORT TERM...(THROUGH LATE THIS AFTERNOON)
ISSUED AT 425 AM CDT THU MAR 28 2013
WEAK BUT PERSISTENT WAA SHOULD ALLOW CLOUDS TO PERSIST OVER MUCH OF
THE CWA TODAY...ALTHOUGH DO EXPECT SOME DIURNALLY DRIVEN
BREAKS/THINNING DURING THE LATE MORNING AND AFTERNOON. THIS WAA
DRIVEN ASCENT IS SHOWING UP NICELY ON THE 290 AND 295 THETA SURFACES
FROM THE 00Z RUNS. RADAR DATA DOES INDICATE SOME WEAK RETURNS TO
THE W/SW OF THE LSX 88D EARLY TODAY...AND HAVE CARRIED A FEW
SPRINKLES WITH THIS WEEPING AC INTO MID MORNING. HAVE ALSO
INTRODUCED SOME SLIGHT CHANCE POPS OVER S SECTIONS OF THE CWA BY
LATE THIS AFTERNOON AS THE WAA APPEARS TO BEGIN TO INTENSIFY BY THIS
TIME...BUT CERTAINLY THE MAIN PRECIP THREAT SHOULD BE LATER TONIGHT.
MEANWHILE...AND MUCH LIKE YESTERDAY...DRIER AIR ASSOCIATED WITH
SLOWLY RETREATING SURFACE HIGH WILL TEND TO KEEP THE CLOUDS AT BAY
OVER NE SECTIONS OF THE CWA.
TEMPERATURES WILL BE A TOUGH CALL...WITH VARIABLE SKY
CONDITIONS...RECEDING SNOW COVER...A SLOWLY MODERATING AIRMASS...AND
A SURFACE WARM FRONT THAT 2M TEMPS FROM THE HI-RES MODELS SUGGEST
MAY REACH OUR FAR S COUNTIES. UNDER THE CLOUD COVER IN MID MO HAVE
LEANED TOWARDS CONDITIONAL CLIMATOLOGY...WHICH WOULD SUGGEST ABOUT A
15 DEGREE CLIMB FROM MORNING LOWS...WHILE IN OUR FAR S HAVE ALLOWED
TEMPS TO PUSH THE 60 DEGREE MARK. FINALLY...IN THE MORE SUNNY AREAS
IN OUR NE COUNTIES...HAVE RAISED MAX TEMPS ABOUT ONE CAT FROM
YESTERDAYS HIGHS.
TRUETT
&&
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 425 AM CDT THU MAR 28 2013
MODELS HAVE BEEN CONSISTENTLY SHOWING AN INCREASE IN MOISTURE RETURN
FOR TONIGHT. THERE ARE A COUPLE OF WEAK SIGNALS FOR PCPN INCLUDING A
WEAK SHORTWAVE THAT WILL BE APPROACHING THE AREA WITHIN NW FLOW
ALOFT...AN AREA OF MODERATE ISENTROPIC ASCENT ALONG THE 290K SFC AS
DEPICTED BY THE ECMWF/GFS/GEM...AND WEAK H85 MCONV ALONG THE NOSE OF
A SWLY LLJ. CHC POPS FOR SHRA/TSRA LOOK REASONABLE IN THE ABSENCE OF
ANY SINGLE STRONG SIGNAL FOR PCPN OTHER THAN MOISTURE RETURN. PDS OF
ISO-SCT PCPN MAY CONTINUE THROUGH FRI NIGHT INVOF A DVLPG BAROCLINIC
ZONE IN SRN MO UNTIL THE BDRY LIFTS NEWD ON SAT.
TWO CDFNTS ARE STILL EXPECTED TO MOVE ACROSS MO/IL THIS WEEKEND
HOWEVER RECENT MODELS RUNS HAVE BEEN MUCH QUICKER WITH FROPA TIMING
THAN THEY WERE 24 HR AGO. IT NOW APPEARS THAT THE FIRST CDFNT WILL
MOVE THROUGH THE CWA ON SAT NIGHT. MODELS CONTINUE TO SHOW A FEW
HUNDRED J/KG OF MUCAPE ON SAT NIGHT THEREFORE THERE MAY BE SOME
EMBEDDED THUNDERSTORMS ALONG WITH THE RAIN SHOWERS. A VORT LOBE WILL
DRIVE THE SECONDARY CDFNT THROUGH MO/IL ON SUNDAY NIGHT AND EARLY
MONDAY MORNING...BRINGING A REINFORCING SHOT OF COLD AIR TO THE AREA
WHILE A 1030MB SFC HIGH BUILDS SEWD OUT OF CANADA. WITH A MUCH
COLDER AIR MASS IN PLACE ACROSS THE REGION...THE NEXT ROUND OF PCPN
COULD FALL AS A RAIN/SNOW MIX WHEN ANOTHER VORT LOBE MOVES ACROSS
THE AREA ON MON NIGHT AND TUE. GFS/ECMWF REMAIN IN POOR AGREEMENT
REGARDING FEATURES WITHIN THE LARGE SCALE PATTN AFTER 00Z TUE
HOWEVER BOTH MODELS DO SHOW A POTENTIAL SRN STREAM SYSTEM FOR
SOMETIME DURING THE MIDDLE OR LATE PART OF THE WEEK. TEMPERATURES
REMAIN BELOW NORMAL THROUGH THE EXTENDED FCST PD.
KANOFSKY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1209 PM CDT THU MAR 28 2013
EXPECT DRY AND VFR CONDITIONS UNTIL AFTER 00Z WHEN AN UPPER LEVEL
DISTURBANCE WILL BRING -SHRA AND ISOLD -TSRA TO THE REGION. THESE
-SHRA WILL MOVE INTO CENTRAL AND SOUTHEASTERN MISSOURI FIRST...AND
THEN SPREAD INTO THE ST. LOUIS METRO TAF SITES AROUND 06Z. CEILINGS
WILL THEN FALL INTO THE LOW MVFR/PERHAPS IFR CATEGORY AFTER 10Z WITHOUT
MUCH IMPROVEMENT UNTIL MIDDAY FRIDAY. WINDS WILL REMAIN OUT OF THE
EAST-SOUTHEAST THROUGH THE END OF THE PERIOD/
SPECIFICS FOR KSTL...EXPECT DRY AND VFR CONDITIONS INTO THE EVENING.
THEREAFTER...THERE WILL BE AN INCREASING CHANCE OF RAIN...
PARTICULARLY AFTER MIDNIGHT. CEILINGS WILL DECREASE TO LOW MVFR OR
IFR THROUGH FRIDAY MORNING BEFORE INCREASING ABOVE 2000FT ON
SATURDAY.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1258 PM CDT THU MAR 28 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CDT THU MAR 28 2013
PRIMARY FORECAST LIES WITH TEMPERATURES AND FOG POTENTIAL.
QUIET CONDITIONS IN PLACE EARLY THIS MORNING...WITH UPPER AIR
PROFILER AND SATELLITE DATA SHOWING SLIGHT NORTHWESTERLY FLOW SET
UP OVER THE REGION...AS WEAK RIDGING SITS OVER THE ROCKIES AND
LOW PRESSURE/TROUGHING AFFECTS THE NORTHEASTERN CONUS. OUTSIDE OF
SOME MID/UPPER LEVEL CLOUDS GRADUALLY CREEPING EAST FROM THE HIGH
PLAINS AND ROCKIES...SKIES ACROSS THE CWA ARE CLEAR. THE SURFACE
PATTERN OVER THE CENTRAL PLAINS REMAINS WEAK...WITH HIGH PRESSURE
EXTENDING FROM ONTARIO TO THE GULF COAST...WHILE A STATIONARY
BOUNDARY LIES ALONG THE FRONT RANGE OF THE ROCKIES...RESULTING IN
CONTINUED LIGHT AND VARIABLE WINDS ACROSS THE CWA. REALLY HASNT
BEEN AT ANY HINTS OF FOG DEVELOPMENT YET THIS MORNING...BUT SOME
THE HRRR ESP CONTINUES TO SHOW THE POTENTIAL CLOSER TO
SUNRISE...SO WILL CONTINUE TO KEEP THE PATCHY MENTION GOING IN THE
FORECAST FOR THIS MORNING.
LOOKING AT THE REST OF THE SHORT TERM FORECAST...IT REMAINS A DRY
ONE WITH NO NOTABLE CHANGES OVERALL IN THE UPPER LEVEL PATTERN.
SRN PORTIONS OF THE CWA WONT BE TOO TERRIBLY FAR AWAY FROM
PRECIPITATION FORECAST OVER CENTRAL KS OVERNIGHT TONIGHT ALONG A
SFC WARM FRONT AS AN UPPER LEVEL DISTURBANCE PASSES THROUGH...ALSO
AIDED BY AN INCREASE LLJ. AT THE SURFACE...AGAIN NOT EXPECTING ANY
SIGNIFICANT CHANGES...REMAINING FAIRLY WEAK AND KEEPING WINDS
GENERALLY E/SERLY. SHOULD SEE A BUMP UP IN SPEEDS DURING THE
DAYTIME HOURS TODAY INTO THE 10 TO 15 MPH RANGE...BUT WILL LIKELY
DIE OFF AGAIN THIS EVENING/OVERNIGHT WITH A BOUNDARY LOOKING TO
SET UP OVER THE CWA. THIS IS AGAIN SOME CONCERN FOR SOME FOG
TONIGHT...WITH THE LIGHT WINDS RETURNING...BUT CONFIDENCE IS NOT
HIGH IN ITS OCCURRENCE...SO KEPT IT ONLY A PATCHY MENTION.
DEPENDING ON HOW THE REST OF THIS MORNING GOES AND WITH 12Z
MODELS...DAY SHIFT MAY BE ABLE TO REMOVE IT FROM THE FORECAST.
AS FAR AS TEMPERATURES GO...SOME GUIDANCE AND MODELS THE LAST
COUPLE OF DAYS HAVE REALLY UNDERDONE HIGHS...AND AM CONCERNED IT
MAY HAPPEN AGAIN TODAY...THOUGH MAYBE NOT QUITE TO THE EXTENT OF
PREVIOUS DAYS. STICKING CLOSER TO THE NAM/MET/ECMWF FOR TODAYS
HIGHS...YESTERDAY HAD LITTLE PROBLEM GETTING INTO THE MID
50S...AND WITH A GENERALLY SIMILAR SET UP TODAY BUT A SLIGHT
INCREASE IN TEMPS ALOFT...FELT THAT UPPER 50S/LOWER 60S WAS
REASONABLE. MAY BE A FEW MORE CLOUDS AROUND TODAY...AND AT THIS
POINT DONT FEEL IT WILL HOLD BACK TEMPS SIGNIFICANTLY...BUT IT
WILL BE SOMETHING FOR THE DAY SHIFT TO KEEP A CLOSE EYE ON.
OVERNIGHT LOWS TONIGHT LOOK TO COOL INTO THE MID 30S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 409 AM CDT THU MAR 28 2013
GUIDANCE SUGGESTS THE LONG TERM FORECAST PERIOD WILL BE DOMINATED
BY NORTHWESTERLY MID AND UPPER LEVEL FLOW. CHANCES FOR
PRECIPITATION ARE SPRINKLED THROUGHOUT THE LONG TERM FORECAST
PERIOD...THE FIRST OF WHICH PRESENTS ITSELF LATE FRIDAY AFTERNOON.
AN OVERALL LACK IN KINEMATIC FORCING WOULD OTHERWISE PRESENT DRY
CONDITIONS TO THE AREA ON FRIDAY...HOWEVER FORECAST PROXIMITY
SOUNDINGS...PER THE NAM AND OPERATIONAL GFS...SUGGEST WESTERN
PORTIONS OF OUR CWA...PRIMARILY WEST OF HIGHWAY 183...WILL REACH A
CONVECTIVE TEMPERATURE IN THE LOWER 60S. SHOULD CONVECTIVE
INITIATION BE REALIZED LATE FRIDAY AFTERNOON...THESE SAME
PROXIMITY SOUNDINGS SUGGEST 200-500J/KG SBCAPE WILL BE READY FOR
UPDRAFT PRODUCTION. FARTHER EAST ACROSS OUR CWA IT APPEARS A LOW
LEVEL CAPPING INVERSION WILL KEEP CONVECTION AT BAY...BUT GIVEN
THE THREAT FOR CONVECTION FARTHER WEST...OPTED TO KEEP THE SLIGHT
CHANCE POPS INHERITED FROM THE PREVIOUS FORECAST. GIVEN THE
AFOREMENTIONED INSTABILITY AND THE FAIRLY LOW FREEZING
HEIGHTS...WILL GO AHEAD AND CONTINUE HIGHLIGHTING SMALL HAIL IN
THE HWO FOR FRIDAY AFTERNOON.
SURFACE-BASED CONVECTION ACROSS OUR WEST FRIDAY AFTERNOON...SHOULD
IT BE REALIZED...WILL QUICKLY DISSIPATE TOWARDS SUNSET AS
DIABATIC HEATING IS LOST ACROSS THE AREA. THAT BEING
SAID...ADDITIONAL PRECIPITATION WILL BE POSSIBLE ACROSS MOST ALL
OF OUR CWA FRIDAY NIGHT INTO EARLY SATURDAY MORNING AS THE AXIS OF
A 25-30KT LOW LEVEL JET STREAK SETS UP ACROSS THE AREA. AT THIS
TIME IS APPEARS THE NOSE OF THIS LOW LEVEL JET STREAK WILL BE
REALIZED ACROSS NORTHEASTERN NEBRASKA INTO PORTIONS OF SOUTH
DAKOTA. WITH THE RESULTANT AREA OF LOW LEVEL CONVERGENCE ALSO
EXPECTED TO RESIDE NORTH OF OUR AREA...QPF FIELDS FROM MOST MODELS
KEEP THE HEAVIEST PRECIPITATION ON FRIDAY NIGHT TO OUR
NORTH/NORTHEAST. THAT BEING SAID IT STILL APPEARS THERE WILL BE
ENOUGH LOW LEVEL THERMAL ADVECTION ALONG THE LOW LEVEL JET AXIS
FOR PRECIPITATION PRODUCTION ACROSS MOST ALL OF OUR CWA. WENT
AHEAD WITH 30%-50% POPS ACROSS OUR NORTH/NORTHEAST FRIDAY
NIGHT/SATURDAY MORNING...CLOSER TO THE NOSE OF THE LOW LEVEL
JET...WITH POPS CLOSER TO 20% FARTHER SOUTH/SOUTHWEST ACROSS OUR
CWA.
THERE MAY BE SOME LINGERING CONVECTION ALONG THE LOW LEVEL JET
AXIS AROUND OR JUST AFTER SUNRISE SATURDAY...HOWEVER THIS
ACTIVITY SHOULD WANE AS THE LOW LEVEL JET DECREASES IN INTENSITY.
WENT AHEAD AND KEPT 20%-30% POPS GOING ACROSS MUCH OF OUR CWA 12Z-
18Z SATURDAY AS A RESULT. THE PASSAGE OF A SUBTLE MID LEVEL SHORT
WAVE ACROSS THE NORTHERN PLAINS IS EXPECTED TO HELP PUSH A LOW
LEVEL BAROCLINIC ZONE ACROSS OUR AREA DURING THE DAY SATURDAY AND
WHILE MUCH OF OUR AREA SHOULD BE DRY ON SATURDAY FOLLOWING THE
DISSIPATION OF MORNING CONVECTION...THERE IS SOME CONCERN THAT
THERE COULD BE ADDITIONAL AFTERNOON CONVECTION ALONG THE LOW LEVEL
BAROCLINIC ZONE ACROSS OUR SOUTH. GIVEN THIS...WENT AHEAD AND KEPT
~20% POPS GOING ACROSS OUR SOUTH. FORECAST PROXIMITY SOUNDINGS
FROM ACROSS OUR SOUTH SUGGEST 200-400J/KG 0-1MLCAPE VALUES COULD
BE REALIZED SATURDAY AFTERNOON AND MUCH LIKE FRIDAY
AFTERNOON...WILL CONTINUE TO HIGHLIGHT THE CHANCE FOR SMALL HAIL
IN THE HWO. ONCE THE LOW LEVEL BAROCLINIC ZONE DOES CLEAR OUR AREA
SATURDAY...DRY CONDITIONS ARE THEN EXPECTED SATURDAY NIGHT AS AN
OVERALL LACK IN KINEMATIC FORCING OVERTAKES THE AREA.
THE PERIOD OF DRY CONDITIONS WILL BE SHORT-LIVED HOWEVER AS A MID
LEVEL SHORT WAVE ADVANCES SOUTHEAST OUT OF CANADA AND ACROSS THE
UPPER MISSISSIPPI VALLEY...PERHAPS CLIPPING PORTIONS OF THE
NORTHERN AND CENTRAL PLAINS...NEXT MONDAY INTO TUESDAY. DPVA AND
MID LEVEL THERMAL ADVECTION AHEAD OF THE MID LEVEL TROUGH AXIS IS
EXPECTED TO REMAIN EAST/NORTHEAST OF OUR AREA WHICH WOULD
OTHERWISE SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL ALSO
REMAIN EAST/NORTHEAST OF OUR AREA. THAT WONT BE THE CASE HOWEVER
AS A 90-100KT MID LEVEL JET STREAK ACCOMPANIES THE SHORT WAVE
ACROSS PORTIONS OF THE REGION. THE RIGHT-REAR QUADRANT OF THIS MID
LEVEL JET STREAK IS EXPECTED MOVE OVER OUR AREA SUNDAY THROUGH
MONDAY...WITH ENOUGH OF A DIRECT THERMAL CIRCULATION AND RESULTANT
OMEGA FOR PRECIPITATION PRODUCTION ACROSS MOST ALL OF OUR CWA.
ALLBLEND PROVIDED A WIDE RANGE OF POPS DURING THIS 36-HOUR
PERIOD...RANGING FROM ~20% TO ~50%...WITH THE HIGHEST POPS
CURRENTLY FORECAST SUNDAY NIGHT. SAW LITTLE REASON TO DISAGREE
WITH ALLBLEND AND THUS LEFT THESE POPS UNCHANGED. FORECAST
PROXIMITY SOUNDINGS FROM ACROSS THE CWA...PER THE OPERATIONAL GFS
AND EC...SUGGEST THE LOWER TROPOSPHERE SHOULD BE WARM ENOUGH FOR
RAIN DURING THE DAY SUNDAY. WITH CONTINUED LOW LEVEL COLD AIR
ADVECTION HOWEVER A TRANSITION TO SNOWFALL IS APPEARING MORE AND
MORE LIKELY ACROSS MOST ALL OF THE CWA SUNDAY NIGHT AND INTO THE
DAY MONDAY. QPF FIELDS FROM THE OPERATIONAL GFS AND EC BOTH
SUGGEST A COUPLE TENTHS OF AN INCH OF LIQUID PRECIPITATION COULD
BE REALIZED FROM THIS SYSTEM...WHICH SEEMS REASONABLE GIVEN
SUFFICIENT LOWER TROPOSPHERIC MOISTURE WILL BE IN PLACE AND OMEGA
VALUES APPROACHING 10-UBAR/S. GIVEN ALL THIS ONE MIGHT SUSPECT AN
INCH OR TWO OF SNOW ACCUMULATION COULD BE REALIZED SUNDAY NIGHT
INTO MONDAY...BUT SINCE WE ARE NOW APPROACHING EARLY APRIL AND THE
SUN ANGLE IS SO HIGH...IT SEEMS HIGHLY UNLIKELY MUCH OF ANY
ACCUMULATION WILL BE REALIZED AS MUCH OF THE SNOWFALL SHOULD MELT
ON CONTACT WITH THE WARM SURFACE. SO...DESPITE THIS BEING A LATE-
SEASON SNOW EVENT...LITTLE IN THE WAY OF IMPACTS ARE CURRENTLY
EXPECTED ACROSS THE CWA AND WILL LEAVE ANY SUCH WORDING OUT OF THE
HWO. AN OVERALL LACK IN KINEMATIC FORCING SHOULD THEN PROVIDE DRY
CONDITIONS TO OUR AREA MONDAY NIGHT THROUGH THE END OF THE CURRENT
FORECAST PERIOD.
TEMPERATURES IN THE 50S AND 60S ARE STILL EXPECTED FRIDAY THROUGH
SUNDAY...WITH A COOLING TREND PUSHING HIGHS DOWN INTO THE 30S
MONDAY...FOLLOWED BY AFTERNOON HIGHS IN THE 40S AND 50S TO FINISH
THE FORECAST PERIOD. OVERNIGHT LOWS IN THE 30S AND 40S SHOULD BE
OBSERVED FRIDAY NIGHT AND SATURDAY NIGHT...WITH COOLER AIR THEN
PRESENTING OVERNIGHT LOWS IN THE 20S ACROSS MUCH OF THE AREA
SUNDAY NIGHT...IN THE TEENS AND 20S MONDAY NIGHT...AND THEN BACK
INTO THE 20S AND 30S TO FINISH THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1258 PM CDT THU MAR 28 2013
MID LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS THE TERMINAL FOR
THE NEXT HOUR OR TWO SCATTERING OUT BY LATE AFTERNOON. WITH
CLEARING SKIES...LIGHT SOUTHEASTERLY WINDS AND INCREASING LOW
LEVEL MOISTURE...MODELS ARE KEYING IN ON SOME FOG DEVELOPMENT IN
THE VICINITY OF THE TERMINAL. WENT AHEAD AND LOWERED VISIBILITIES
TO MVFR LEVELS FOR A FEW HOURS FRIDAY MORNING...ALBEIT SOME
GUIDANCE IS HINTING AT POSSIBLE LIFR CIGS AND VSBYS BY DAYBREAK
FRIDAY. AFTER ANY FOG THAT DOES FORM BURNS OFF BY MID
MORNING...EXPECT ANOTHER NICE DAY AT THE TERMINAL...WITH LIGHT
SOUTHEASTERLY WINDS AND SCT-BKN HIGH CLOUD COVER EXPECTED AFT
29/15Z.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADO
LONG TERM...BRYANT
AVIATION...SAR
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
545 PM CDT THU MAR 28 2013
.DISCUSSION...
DENSE FOG CONTINUES WEST OF THE DEVILS LAKE AND LANGDON AREAS SO
WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR THIS AREA. LIGHT
WINDS AND FALLING TEMPS TONIGHT WILL LIKELY RESULT IN A WIDER AREA
SO WILL CONTINUE TO MONITOR.
&&
.AVIATION...
FOG WILL BE A CONCERN OVERNIGHT...AND COULD BE LOCALLY DENSE AT
TIMES. HAVE GONE WITH IFR CONDITIONS NEAR DVL WITH LOW CIGS/VSBY
FROM DENSE FOG. THERE IS POTENTIAL FOR WIDESPREAD IFR/LIFR
CONDITIONS OVERNIGHT IN FOG...AND HAVE ALREADY MENTIONED MVFR
CONDITIONS IN ALL AREAS AFTER 06Z.
&&
.PREV DISCUSSION... /ISSUED 345 PM CDT THU MAR 28 2013/
SHORT TERM...TONIGHT THROUGH SUNDAY
FOG ACROSS THE DEVILS LAKE BASIN HAS BEEN A REAL HEADACHE TODAY.
WILL ALLOW THE DENSE FOG ADVISORY TO EXPIRE AT 4 PM WITH SOME HOLES
DEVELOPING IN LATEST SATELLITE LOOP...ALTHOUGH A FEW LOCATIONS ARE
STILL REPORTING REDUCTIONS IN VISIBILITY TO 1/4 MILE. LATEST HRRR
SUGGESTS FOG WILL EXPAND THIS EVENING AND PERSIST OVERNIGHT IN
SOME FORM MAINLY ACROSS EASTERN ND...SO WOULD NOT BE SURPRISED IF
A NEW ADVISORY IS NEEDED THIS EVENING. MID-LEVEL MOISTURE FROM THE
NORTHERN VALLEY INTO CENTRAL MN HAS ALSO REMAINED STATIONARY
TODAY. LATEST RAP SHOWS 850 HPA MOISTURE DISSIPATING SOMEWHAT...
BUT STILL EXPECT SOME DEGREE OF CLOUD COVER OVERNIGHT. ALL OF THIS
WILL CREATE A CHAOTIC TEMPERATURE PATTERN...BUT FOR AREAS THAT
CLEAR OUT...EXPECT LOWER TO MID TEENS FOR OVERNIGHT LOWS.
LATE FRIDAY INTO SATURDAY...ALL MODELS SHOW A WEAK OPEN WAVE
MOVING ACROSS THE NORTHERN PLAINS. BEST MID-LEVEL WARM AIR ADVECTION/
ISENTROPIC LIFT ON THE 285 K SURFACE IS ACROSS THE SOUTHERN FORECAST
AREA COINCIDENT WITH THERMAL GRADIENT. MID-LEVEL TEMPERATURES
SHOULD BE WARM ENOUGH FOR LIQUID PRECIPITATION...ALTHOUGH SUB-
FREEZING GROUND TEMPERATURES WOULD RESULT IN FREEZING ON CONTACT.
USED SREF PROBABILITY OF PRECIPITATION TYPE TO DELINEATE AREAS OF
FREEZING RAIN/RAIN/SNOW...ALTHOUGH DOMINANT TYPE SHOULD BE FREEZING
RAIN. OVERALL...LIQUID AMOUNTS SHOULD BE A TENTH OF INCH OR
LESS...BUT TRAVEL COULD BECOME TRICKY FOR AREAS THAT SEE
ACCUMULATIONS.
TEMPERATURES CRASH SATURDAY NIGHT AND EARLY SUNDAY MORNING AS A
STRONG COLD FRONT DROPS ACROSS THE REGION. HIGHS SUNDAY AFTERNOON
WILL DROP BACK INTO THE 20S REGION-WIDE AND 25 TO 30 KTS IN A
VERY DEEP BOUNDARY LAYER WILL RESULT IN BREEZY NORTHWEST WIND.
SOME LIGHT SNOW IS POSSIBLE...BUT NOT EXPECTING MUCH ACCUMULATION
AT THIS TIME.
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
EXTENDED MODELS ARE IN FAIRLY GOOD AGREEMENT WITH TEMPS WELL BELOW
NORMAL FOR MON/TUE. TEMPS WILL MODERATE ON WED AHEAD OF ANOTHER COLD
FRONT FOR THU. THERE IS STILL A DEEP SNOW PACK IN PLACE IN ALL
AREAS...SO TEMPS WILL CONTINUE TO BE MODULATED BY THE SNOW COVER. NO
MAJOR STORMS ARE ON THE HORIZON...AND WILL KEEP A DRY EXTENDED
FORECAST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 10 AM CDT FRIDAY FOR NDZ006-007-014-015-
024.
MN...NONE.
&&
$$
GODON
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
345 PM CDT THU MAR 28 2013
.SHORT TERM...TONIGHT THROUGH SUNDAY
FOG ACROSS THE DEVILS LAKE BASIN HAS BEEN A REAL HEADACHE TODAY.
WILL ALLOW THE DENSE FOG ADVISORY TO EXPIRE AT 4 PM WITH SOME HOLES
DEVELOPING IN LATEST SATELLITE LOOP...ALTHOUGH A FEW LOCATIONS ARE
STILL REPORTING REDUCTIONS IN VISIBILITY TO 1/4 MILE. LATEST HRRR
SUGGESTS FOG WILL EXPAND THIS EVENING AND PERSIST OVERNIGHT IN
SOME FORM MAINLY ACROSS EASTERN ND...SO WOULD NOT BE SURPRISED IF
A NEW ADVISORY IS NEEDED THIS EVENING. MID-LEVEL MOISTURE FROM THE
NORTHERN VALLEY INTO CENTRAL MN HAS ALSO REMAINED STATIONARY
TODAY. LATEST RAP SHOWS 850 HPA MOISTURE DISSIPATING SOMEWHAT...
BUT STILL EXPECT SOME DEGREE OF CLOUD COVER OVERNIGHT. ALL OF THIS
WILL CREATE A CHAOTIC TEMPERATURE PATTERN...BUT FOR AREAS THAT
CLEAR OUT...EXPECT LOWER TO MID TEENS FOR OVERNIGHT LOWS.
LATE FRIDAY INTO SATURDAY...ALL MODELS SHOW A WEAK OPEN WAVE
MOVING ACROSS THE NORTHERN PLAINS. BEST MID-LEVEL WARM AIR ADVECTION/
ISENTROPIC LIFT ON THE 285 K SURFACE IS ACROSS THE SOUTHERN FORECAST
AREA COINCIDENT WITH THERMAL GRADIENT. MID-LEVEL TEMPERATURES
SHOULD BE WARM ENOUGH FOR LIQUID PRECIPITATION...ALTHOUGH SUB-
FREEZING GROUND TEMPERATURES WOULD RESULT IN FREEZING ON CONTACT.
USED SREF PROBABILITY OF PRECIPITATION TYPE TO DELINEATE AREAS OF
FREEZING RAIN/RAIN/SNOW...ALTHOUGH DOMINANT TYPE SHOULD BE FREEZING
RAIN. OVERALL...LIQUID AMOUNTS SHOULD BE A TENTH OF INCH OR
LESS...BUT TRAVEL COULD BECOME TRICKY FOR AREAS THAT SEE
ACCUMULATIONS.
TEMPERATURES CRASH SATURDAY NIGHT AND EARLY SUNDAY MORNING AS A
STRONG COLD FRONT DROPS ACROSS THE REGION. HIGHS SUNDAY AFTERNOON
WILL DROP BACK INTO THE 20S REGION-WIDE AND 25 TO 30 KTS IN A
VERY DEEP BOUNDARY LAYER WILL RESULT IN BREEZY NORTHWEST WIND.
SOME LIGHT SNOW IS POSSIBLE...BUT NOT EXPECTING MUCH ACCUMULATION
AT THIS TIME.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
EXTENDED MODELS ARE IN FAIRLY GOOD AGREEMENT WITH TEMPS WELL BELOW
NORMAL FOR MON/TUE. TEMPS WILL MODERATE ON WED AHEAD OF ANOTHER COLD
FRONT FOR THU. THERE IS STILL A DEEP SNOW PACK IN PLACE IN ALL
AREAS...SO TEMPS WILL CONTINUE TO BE MODULATED BY THE SNOW COVER. NO
MAJOR STORMS ARE ON THE HORIZON...AND WILL KEEP A DRY EXTENDED
FORECAST.
&&
.AVIATION...
FOG WILL BE A CONCERN OVERNIGHT...AND COULD BE LOCALLY DENSE AT TIMES.
HAVE GONE WITH IFR CONDITIONS NEAR DVL WITH LOW CIGS/VSBY FROM DENSE
FOG. THERE IS POTENTIAL FOR WIDESPREAD IFR/LIFR CONDITIONS OVERNIGHT
IN FOG...AND HAVE ALREADY MENTIONED MVFR CONDITIONS IN ALL AREAS
AFTER 06Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
210 PM CDT THU MAR 28 2013
.UPDATE...
ISSUED AT 206 PM CDT THU MAR 28 2013
AREAS OF FOG WERE DISSIPATING AND VISIBILITIES WERE IMPROVING OVER
NORTHERN AND PARTS OF CENTRAL NORTH DAKOTA. THUS HAVE ALLOWED THE
DENSE FOG ADVISORY TO EXPIRE AT 2 PM CDT. MAY SEE SOME PATCHY
DENSE FOG FOR THE NEXT HOUR OR SO...BUT SHOULD BE LOCALIZED.
UPDATE ISSUED AT 1156 AM CDT THU MAR 28 2013
LOOKING AT FOG TRENDS...THE LIGHT EASTERLY/NORTHEASTERLY WINDS
ALONG THE COTEAU WERE PROVIDING UPSLOPE FLOW AND KEEPING THE
VISIBILITIES IN THE FOG AREA AT 1/4 MILE OR LESS. THE WESTERN AND
SOUTHERN EDGE OF THE FOG AREA WAS DISSIPATING...BASED ON LINTON
VISIBILITY AND WISHEK WEB CAM. WILLISTON WAS IMPROVING...BUT TIOGA
WAS STILL AT 1/4 MILE. THUS ONLY TRIMMED A COUPLE OF COUNTIES FROM
THE DENSE FOG ADVISORY AND EXTENDED IN TIME THE WHOLE ADVISORY
UNTIL 19Z OR 2 PM CDT. BY THEN THE WARM ADVECTION FROM THE
SOUTHWEST AND SUNSHINE ABOVE THE LOW CLOUD/FOG LAYER SHOULD HAVE
WORKED TO DISSIPATE THE FOG COMPLETELY OR AT LEAST ALLOWED
VISIBILITIES TO COME UP ABOVE A MILE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAR 28 2013
THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM IS FOG.
LATEST 11-3.9 SATELLITE IMAGERY AND SURFACE OBSERVATIONS AT 08Z
DEPICT AN AREA OF DENSE FOG AND A LOW STRATUS DECK ACROSS NORTHERN
NORTH DAKOTA...EXPANDING SOUTH TOWARDS THE JAMES RIVER VALLEY.
DEWPOINT DEPRESSIONS ACROSS THE SNOW PACK CONTINUE TO HOVER AROUND 0
DEGREES...INDICATING A VERY MOIST BOUNDARY LAYER. THIS WAS ALSO
COINCIDENT WITH CALM TO LIGHT AND VARIABLE WINDS...GENERATING AN
ENVIRONMENT CONDUCIVE TO MAINTAINING DENSE FOG AND THE DEVELOPMENT
OF FOG FURTHER SOUTH ACROSS THE JAMES RIVER VALLEY. ACROSS THE
SNOWLESS SOUTHWEST...THE LACK OF MOISTURE AND PRESENCE OF HIGH THIN
CIRRUS...HAVE LIMITED THE DEVELOPMENT OF FOG. HAVE DECIDED TO REMOVE
PATCHY FOG WORDING IN THE WEATHER GRIDS...WHILE KEEPING AREAS TO
WIDESPREAD FOG/DENSE FOG WORDING ELSEWHERE. THIS IS SUPPORTED BY THE
4Z HRRR...WHERE IT CONTINUES TO DEPICT WIDESPREAD VISIBILITIES BELOW
ONE HALF MILE WITH LOW STRATUS WHERE A SNOW PACK IS PRESENT THROUGH
THE MORNING. AFTER SUNRISE...THE HRRR HAS THE AREAL COVERAGE OF
LOWERED VISIBILITIES SLOWLY ERODING LATE THIS MORNING...WHILE IT AND
OTHER 00Z MODEL GUIDANCE KEEPS LOW LEVEL STRATUS THROUGH AT LEAST
17Z. THEREAFTER...THE STRATUS DECK AND ANY REMAINING FOG WILL GIVE
WAY TO MOSTLY SUNNY CONDITIONS AND WARMING TEMPERATURES INTO THE MID
20S NORTH TO LOWER 50S SOUTHWEST DURING THE AFTERNOON. AT THIS
TIME...WILL KEEP DENSE FOG ADVISORY GOING AS IS SINCE IT IS
REPRESENTATIVE OF CURRENT CONDITIONS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 AM CDT THU MAR 28 2013
NORTHWEST FLOW ALOFT IS FORECAST TO REMAIN IN PLACE THROUGH MUCH
IF NOT ALL OF THE LONG TERM FORECAST PERIOD. WILL SEE AN ACTIVE
FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND. THE
EC/GFS/GEM/NAM ALL CONTINUE TO DEPICT AN EMBEDDED MID LEVEL S/WV
IMPULSE SLIDING SOUTHEAST ACROSS NORTH DAKOTA ALONG WITH AN AREA
OF ASSOCIATED SURFACE LOW PRESSURE FRIDAY/FRIDAY NIGHT. WILL
MAINTAIN CHANCES FOR MIXED PRECIPITATION WITH THE COMBINATION OF
WAA ALOFT COMBINED WITH BELOW/ABOVE FREEZING SURFACE AIR
TEMPERATURES. BOTH THE NAM AND GFS STILL GENERATE DAYTIME
INSTABILITY FRIDAY MID/LATE AFTERNOON OVER SOUTHWEST NORTH
DAKOTA...WITH THE LATEST SPC DAY 2 OUTLOOK NOW JUST OFF TO OUR
SOUTH AND WEST. WILL KEEP AN EYE ON THIS PERIOD OVER THE NEXT FEW
FORECAST CYCLES IN CASE WE NEED TO ADD THUNDER INTO THE FORECAST.
CLOSED UPPER LOW MOVING SOUTH ACROSS CENTRAL CANADA SATURDAY AND
INTO THE GREAT LAKES REGION SUNDAY AND MONDAY WILL BRING A SURGE
OF COLDER AIR INTO THE NORTHERN PLAINS FOR THE EASTER HOLIDAY
WEEKEND. BUMPED HIGH/LOW TEMPERATURES DOWN SEVERAL DEGREES SUNDAY
AND MONDAY. ENOUGH ENERGY ALOFT SHOULD ALSO SEE SOME SLIGHT
CHANCES FOR PRECIPITATION THIS WEEKEND.
WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT
WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS
DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. FOR NOW
STUCK WITH ALLBLEND POPS GIVING ME SLIGHT CHANCES FOR MIXED PRECIP
WED/WED NIGHT. TEMPERATURES MODERATE BACK TO NORMAL MID-WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1156 AM CDT THU MAR 28 2013
WILL KEEP VSBYS LOW EARLY AFTERNOON AT KMOT/KBIS/KJMS THEN RAISE
GRADUALLY. EXPECT FOG TO RETURN AFT 03Z-06Z TONIGHT. ON FRIDAY A
SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA AND AN UPPER LEVEL
SHORTWAVE WILL BE ASSOCIATED WITH SMALL CHANCES OF LIGHT
PRECIPITATION. FREEZING RAIN CHANGING TO RAIN IN KHEI/KDIK...WITH
CHANCES OF FREEZING RAIN/ICE PELLETS FOR KISN/KMOT. FOR NOW
HOWEVER HAVE ONLY VCSH SINCE PROBABILITIES ARE LOW AND CONFIDENCE
IS LOW FOR TIMING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...LTH
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1206 PM CDT THU MAR 28 2013
.UPDATE...
ISSUED AT 1156 AM CDT THU MAR 28 2013
LOOKING AT FOG TRENDS...THE LIGHT EASTERLY/NORTHEASTERLY WINDS
ALONG THE COTEAU WERE PROVIDING UPSLOPE FLOW AND KEEPING THE
VISIBILITIES IN THE FOG AREA AT 1/4 MILE OR LESS. THE WESTERN AND
SOUTHERN EDGE OF THE FOG AREA WAS DISSIPATING...BASED ON LINTON
VISIBILITY AND WISHEK WEB CAM. WILLISTON WAS IMPROVING...BUT TIOGA
WAS STILL AT 1/4 MILE. THUS ONLY TRIMMED A COUPLE OF COUNTIES FROM
THE DENSE FOG ADVISORY AND EXTENDED IN TIME THE WHOLE ADVISORY
UNTIL 19Z OR 2 PM CDT. BY THEN THE WARM ADVECTION FROM THE
SOUTHWEST AND SUNSHINE ABOVE THE LOW CLOUD/FOG LAYER SHOULD HAVE
WORKED TO DISSIPATE THE FOG COMPLETELY OR AT LEAST ALLOWED
VISIBILITIES TO COME UP ABOVE A MILE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CDT THU MAR 28 2013
THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM IS FOG.
LATEST 11-3.9 SATELLITE IMAGERY AND SURFACE OBSERVATIONS AT 08Z
DEPICT AN AREA OF DENSE FOG AND A LOW STRATUS DECK ACROSS NORTHERN
NORTH DAKOTA...EXPANDING SOUTH TOWARDS THE JAMES RIVER VALLEY.
DEWPOINT DEPRESSIONS ACROSS THE SNOW PACK CONTINUE TO HOVER AROUND 0
DEGREES...INDICATING A VERY MOIST BOUNDARY LAYER. THIS WAS ALSO
COINCIDENT WITH CALM TO LIGHT AND VARIABLE WINDS...GENERATING AN
ENVIRONMENT CONDUCIVE TO MAINTAINING DENSE FOG AND THE DEVELOPMENT
OF FOG FURTHER SOUTH ACROSS THE JAMES RIVER VALLEY. ACROSS THE
SNOWLESS SOUTHWEST...THE LACK OF MOISTURE AND PRESENCE OF HIGH THIN
CIRRUS...HAVE LIMITED THE DEVELOPMENT OF FOG. HAVE DECIDED TO REMOVE
PATCHY FOG WORDING IN THE WEATHER GRIDS...WHILE KEEPING AREAS TO
WIDESPREAD FOG/DENSE FOG WORDING ELSEWHERE. THIS IS SUPPORTED BY THE
4Z HRRR...WHERE IT CONTINUES TO DEPICT WIDESPREAD VISIBILITIES BELOW
ONE HALF MILE WITH LOW STRATUS WHERE A SNOW PACK IS PRESENT THROUGH
THE MORNING. AFTER SUNRISE...THE HRRR HAS THE AREAL COVERAGE OF
LOWERED VISIBILITIES SLOWLY ERODING LATE THIS MORNING...WHILE IT AND
OTHER 00Z MODEL GUIDANCE KEEPS LOW LEVEL STRATUS THROUGH AT LEAST
17Z. THEREAFTER...THE STRATUS DECK AND ANY REMAINING FOG WILL GIVE
WAY TO MOSTLY SUNNY CONDITIONS AND WARMING TEMPERATURES INTO THE MID
20S NORTH TO LOWER 50S SOUTHWEST DURING THE AFTERNOON. AT THIS
TIME...WILL KEEP DENSE FOG ADVISORY GOING AS IS SINCE IT IS
REPRESENTATIVE OF CURRENT CONDITIONS.
.LONG TERM...FRIDAY THROUGH THURSDAY...
ISSUED AT 355 AM CDT THU MAR 28 2013
NORTHWEST FLOW ALOFT IS FORECAST TO REMAIN IN PLACE THROUGH MUCH
IF NOT ALL OF THE LONG TERM FORECAST PERIOD. WILL SEE AN ACTIVE
FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND. THE
EC/GFS/GEM/NAM ALL CONTINUE TO DEPICT AN EMBEDDED MID LEVEL S/WV
IMPULSE SLIDING SOUTHEAST ACROSS NORTH DAKOTA ALONG WITH AN AREA
OF ASSOCIATED SURFACE LOW PRESSURE FRIDAY/FRIDAY NIGHT. WILL
MAINTAIN CHANCES FOR MIXED PRECIPITATION WITH THE COMBINATION OF
WAA ALOFT COMBINED WITH BELOW/ABOVE FREEZING SURFACE AIR
TEMPERATURES. BOTH THE NAM AND GFS STILL GENERATE DAYTIME
INSTABILITY FRIDAY MID/LATE AFTERNOON OVER SOUTHWEST NORTH
DAKOTA...WITH THE LATEST SPC DAY 2 OUTLOOK NOW JUST OFF TO OUR
SOUTH AND WEST. WILL KEEP AN EYE ON THIS PERIOD OVER THE NEXT FEW
FORECAST CYCLES IN CASE WE NEED TO ADD THUNDER INTO THE FORECAST.
CLOSED UPPER LOW MOVING SOUTH ACROSS CENTRAL CANADA SATURDAY AND
INTO THE GREAT LAKES REGION SUNDAY AND MONDAY WILL BRING A SURGE
OF COLDER AIR INTO THE NORTHERN PLAINS FOR THE EASTER HOLIDAY
WEEKEND. BUMPED HIGH/LOW TEMPERATURES DOWN SEVERAL DEGREES SUNDAY
AND MONDAY. ENOUGH ENERGY ALOFT SHOULD ALSO SEE SOME SLIGHT
CHANCES FOR PRECIPITATION THIS WEEKEND.
WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT
WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS
DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. FOR NOW
STUCK WITH ALLBLEND POPS GIVING ME SLIGHT CHANCES FOR MIXED PRECIP
WED/WED NIGHT. TEMPERATURES MODERATE BACK TO NORMAL MID-WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1156 AM CDT THU MAR 28 2013
WILL KEEP VSBYS LOW EARLY AFTERNOON AT KMOT/KBIS/KJMS THEN RAISE
GRADUALLY. EXPECT FOG TO RETURN AFT 03Z-06Z TONIGHT. ON FRIDAY A
SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA AND AN UPPER LEVEL
SHORTWAVE WILL BE ASSOCIATED WITH SMALL CHANCES OF LIGHT
PRECIPITATION. FREEZING RAIN CHANGING TO RAIN IN KHEI/KDIK...WITH
CHANCES OF FREEZING RAIN/ICE PELLETS FOR KISN/KMOT. FOR NOW
HOWEVER HAVE ONLY VCSH SINCE PROBABILITIES ARE LOW AND CONFIDENCE
IS LOW FOR TIMING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 2 PM CDT THIS AFTERNOON FOR NDZ001>005-
009>013-021>023-025-035>037-047-048-051.
&&
$$
UPDATE...JV
SHORT TERM...LTH
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1243 PM CDT THU MAR 28 2013
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
FOG HAS CLEARED ACROSS THE AREA AS INDICATED ON WEBCAMS AND OBS.
MID CLOUDS ARE EXPANDING ACROSS THE REGION BUT SHOULD HAVE
NEGLIGIBLE IMPACT ON FORECAST HIGHS. CURRENT PERIOD AND OVERNIGHT
ARE ON TRACK. ADJUSTED FRI NIGHT/SAT MORNING POPS/WX TO LOWER POPS
IN THE WEST AND RAISE THEM EAST OF THE JAMES BASED ON LATEST
GUIDANCE. PRECIP TYPE CONTINUES TO BE A FORECAST CHALLENGE WITH
THIS UPCOMING SYSTEM.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
WAA BAND OF MID LEVEL CLOUDS WERE FORMING THIS MORNING ACROSS THE
FAR EASTERN CWA. THIS SHOULD CONTINUE TO MOVE EAST. THERE WERE
ALSO MORE MID LEVEL CLOUDS MOVING INTO THE WESTERN CWA EARLY THIS
MORNING. OTHERWISE...THE ISSUE THIS MORNING WILL BE THE FOG
FORMATION. NOT MUCH FOR FOG SHOWING UP ON SURFACE OBS OR SATELLITE
EARLY THIS MORNING. ALTHOUGH...SOME WEB CAMS SHOWED SOME FOG OUT
WEST. MUCH OF THE FOG WAS ACROSS THE BORDER IN ND EXPANDING
SOUTHWARD. WITH THE WINDS BECOMING LIGHT AT ABR ALONG WITH A
DECREASING DEW POINT SPREAD...BELIEVE THIS FOG/STRATUS AREA WILL
CONTINUE TO EXPAND SOUTHWARD INTO NORTHERN SD THIS MORNING. THERE
COULD ALSO BE SOME PATCHY DENSE FOG. THE HRRR MODEL ALSO SHOWED
INDICATIONS OF STRATUS AND LOWER VISIBILITIES DEVELOPING INTO
NORTHERN SD THIS MORNING. THUS...CONTINUED WITH FOG THROUGH 10 AM
WITH SOME PATCHY DENSE FOG. THE VISIBLE SATELLITE SHOWED VERY WELL
WHERE THE SNOW COVERED AREAS REMAIN. SURFACE OBS ALSO SHOW THE
SNOW TO BE DEEP ACROSS MUCH OF THE EASTERN CWA WITH UP TO 12
INCHES STILL IN SOME LOCATIONS. THIS SNOW COVER WILL CONTINUE TO
HAVE AN AFFECT ON TEMPERATURES WITH VERY LITTLE MIXING DESPITE THE
LATE MARCH SUN. FOR TODAY THROUGH FRIDAY...ALL OF THE MODELS SHOW
THE LOW LEVEL 925MB AND 850MB TEMPERATURES RISING. THUS...LOOK FOR
HIGH TEMPERATURES TO BE WARMER EACH DAY FROM THURSDAY TO FRIDAY.
THE BARE GROUND AREAS FOR THE COUNTIES EITHER SIDE OF THE MISSOURI
RIVER WILL WARM UP QUITE A BIT TODAY AND FRIDAY. SHOULD HAVE 50S
AND LOWER 60S FOR THIS AREA FOR BOTH DAYS. INCREASED HIGHS ALSO IN
THE EAST AS THE SNOW COVER DIMINISHES OVER THE NEXT FEW DAYS BUT
WILL STILL HAVE A BIG INFLUENCE ON TEMPERATURES. STILL HAVE HIGHS
IN THE MID 30S TO THE MID 40S OVER THE SNOW COVER FOR THURSDAY
AND FRIDAY. WITH MORE SNOW MELT MOISTURE ALONG WITH LIGHT WINDS
AND A GOOD INVERSION...COULD HAVE SOME MORE FOG EAST IN THE CWA
LATE TONIGHT AND FRIDAY MORNING.
THE MODELS CONTINUE TO SHOW A SHORT WAVE TROUGH ALONG WITH A
SURFACE COOL FRONT DROPPING ACROSS THE REGION FRIDAY NIGHT AND
EARLY SATURDAY. THE MODELS ALL SHOW DIFFERENT SOLUTIONS FOR QPF
WITH THIS SYSTEM. INCREASED POPS TO GOOD CHANCES MAINLY EAST IN
THE CWA FOR FRIDAY NIGHT. WITH ALL OF THE WARM AIR ALONG WITH NOT
MUCH COOLING AT THE SURFACE FRIDAY NIGHT...ALL MODEL INDICATIONS
POINT TO JUST RAIN WITH THIS SYSTEM PASSAGE. SATURDAY WILL HAVE
BETTER MIXING WITH MAINLY COOLER TEMPERATURES OUT WEST WITH STILL
UPPER 30S TO THE MID 40S OVER THE DIMINISHED SNOW COVERED AREAS EAST.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
THE LONG TERM PATTERN WILL FEATURE AN UPPER LOW DROPPING SOUTH
ACROSS CANADA...FIRST MOVING ACROSS NORTHERN MANITOBA AND THEN
EASTWARD TO THE GREAT LAKES REGION. THIS WILL PLACE OUR AREA OF
CONCERN IN NORTHWEST FLOW ALOFT...AND MOST OF THE ENERGY
ASSOCIATED WITH THE UPPER LOW WILL STAY NORTH OF OUR AREA.
HOWEVER...RIGHT NOW...THE BEST CHANCES FOR ANY TYPE OF
PRECIPITATION ACROSS OUR CWA WILL BE ON SUNDAY. MODELS ARE SHOWING
SOME CONSENSUS WITH TRACKING A COLD FRONT ACROSS THE REGION...AND
700 MB OMEGA VALUES INDICATE WEAK TO MODERATE FORCING...SO
INCLUDED A CHANCE OF LIGHT SNOW ACROSS THE SOUTHERN HALF OF THE
CWA. TEMPERATURES REALLY PLUMMET BEHIND THIS FEATURE AS WELL. 925
MB TEMPERATURES DROP INTO THE SINGLE DIGITS AND TEENS BELOW ZERO
SUNDAY AND MONDAY. ALLBLEND HAS BEEN SLOW TO RESPOND TO THE
COOLING TREND...SO USED A DETERMINISTIC MODEL BLEND AND DROPPED
TEMPERATURES ACCORDINGLY. THE COLD AIR DOESNT STICK AROUND TOO
LONG HOWEVER...AND RETURN FLOW WINDS ON TUESDAY SHOULD BE ABLE TO
TRANSPORT WARMER AIR BACK INTO THE REGION BY EARLY TO MID WEEK.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED FOR ALL TERMINALS THROUGH MOST OF THE
VALID TAF PERIOD. THERE IS ANOTHER CHANCE OF RADIATIONAL FOG LATE
TONIGHT AND INTO FRIDAY MORNING FOR ALL TERMINALS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...MOHR
LONG TERM...SERR
AVIATION...SD
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1213 PM CDT THU MAR 28 2013
.AVIATION...
MVFR CIGS SHOULD LIFT TO VFR BY MID AFTERNOON...BUT WILL DROP
BACK DOWN TO MVFR BY MID EVENING. GULF MOISTURE WILL CONTINUE TO
STREAM NORTH OVERNIGHT AND CLOUDS WILL BE VERY SLOW TO LIFT
TOMORROW. GUIDANCE SHOWS A HIGHER INVERSION ON FRIDAY...SO THERE
MAY BE SOME LIGHT SHOWER ACTIVITY POSSIBLE DUE TO THE DEEPER CLOUD
LAYER. FRIDAY CONVECTION STILL APPEARS TO BE CONCENTRATED IN
OKLAHOMA...ALTHOUGH ANY OUTFLOW BOUNDARY THAT MIGHT SLIDE SOUTH
ACROSS THE RED RIVER MAY BRING ACTIVITY CLOSER TO THE METROPLEX
TERMINALS. 84
&&
.UPDATE...
NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST OTHER THAN MINOR
ADJUSTMENTS TO THE HOURLY GRIDS. LOW CLOUDS CONTINUE TO STREAM
NORTHWARD WITH STRONG LOW LEVEL MOISTURE ADVECTION. DEWPOINTS ARE
RUNNING 20 TO 25 DEGREES HIGHER THAN THIS TIME YESTERDAY. CLOUDY
AND INCREASINGLY MOIST CONDITIONS EXPECTED TO PERSIST THROUGH THE
REMAINDER OF THE DAY.
DUNN
&&
.PREV DISCUSSION... /ISSUED 404 AM CDT THU MAR 28 2013/
CURRENT UPPER AIR ANALYSIS DEPICTS UPPER TROUGHS OVER THE
NORTHEAST CONUS...NORTHWEST CANADA AND THE CENTRAL PACIFIC OCEAN
WITH WEAK RIDGING ACROSS THE WESTERN CONUS. THIS PLACES NORTH
TEXAS UNDER MODERATE WESTERLY FLOW ALOFT. AT THE SURFACE...A
SURFACE LOW HAS DEVELOPED ACROSS EASTERN NEW MEXICO WITH A SURFACE
TROUGH EXTENDING TO THE NORTHEAST INTO THE TEXAS PANHANDLE AND
INTO CENTRAL OKLAHOMA. BREEZY SOUTHERLY WINDS IN THE LOW LEVELS OF
THE ATMOSPHERE ARE EXPECTED ONCE AGAIN TODAY. LOW CLOUDS HAVE
DEVELOPED TO OUR SOUTH AND WILL CONTINUE TO STREAM NORTHWARD THIS
MORNING. WEST WINDS AT 800 MB HAVE BROUGHT WARMER TEMPERATURES
ALOFT...AND A STRONG CAPPING INVERSION IS NOW IN PLACE. THIS
INVERSION SHOULD PREVENT THE LOW CLOUDS FROM COMPLETELY MIXING OUT
TODAY...AND CLOUDS SHOULD BE AROUND FOR MOST OF THE DAY.
WITHIN THE WESTERLY FLOW ALOFT...A COUPLE OF WEAK EMBEDDED
DISTURBANCES ARE EXPECTED TO MOVE THROUGH OKLAHOMA. THE FIRST ONE
WILL MOVE THROUGH THIS AFTERNOON...BUT WITH WEAK LIFT FOR OUR AREA AND
THE STRONG CAP IN PLACE...RAIN CHANCES WILL BE MINIMAL. THE NAM
AND RAP ARE MIXING US OUT A BIT MORE THAN THE GFS AND ACTUALLY
SHOW A SMALL AMOUNT OF CAPE UNDER THE CAP. THIS COULD LEAD TO A
FEW SHOWERS LATE THIS AFTERNOON...BUT CONFIDENCE WASNT HIGH
ENOUGH TO MENTION ANYTHING IN THE FORECAST. A SECOND WEAK
SHORTWAVE WILL AGAIN MOVE THROUGH OKLAHOMA LATE TONIGHT. THE BEST
CHANCES OF RAIN SHOULD BE IN OKLAHOMA...WHERE THE BEST LIFT AND
SURFACE TROUGH WILL BE LOCATED. COULD SEE A COUPLE OF SHOWERS OR
STORMS ALONG THE RED RIVER...AND WILL CONTINUE WITH A 20 POP
THERE.
THE STRONG CAP WILL CONTINUE TO HAVE A HOLD ON OUR FORECAST FOR
FRIDAY. THE SURFACE LOW WILL HAVE MOVED A BIT FURTHER EAST...AND
THE BEST CHANCE FOR THE CAP TO BREAK WOULD BE TO THE EAST OF THE
LOW NEAR CHILDRESS. IF THIS WERE TO OCCUR...WE COULD SEE ACTIVITY
MOVE INTO THE NORTHWEST ZONES FRIDAY EVENING. BUT AGAIN...THE CAP
REMAINS IN PLACE AND ACTIVITY WOULD NOT BE EXPECTED TO THRIVE
LONG. WILL CONTINUE WITH A 30 POP FOR THE NORTHWESTERN ZONES AND
20S FOR THE REST OF THE NORTHERN HALF OF THE CWA.
FOR SATURDAY...THE NAM COMPLETELY ERODES THE CAP AND HAS PRECIP FOR
THE AREA. HOWEVER...THIS IS FEEDBACK FROM THE NAM BRINGING IN
PRECIP THROUGH THE REGION FROM THE FRIDAY NIGHT SYSTEM. BASICALLY
THE NAM IS COOLING THE WARM LAYER AS THE MODEL IS COMPUTING RAIN
EVAPORATING WITHIN THIS LAYER. THEREFORE AM LESS OPTIMISTIC THAN
THE NAM FOR POPS SATURDAY...AS CONFIDENCE IS NOT HIGH WITH THE
FRIDAY SYSTEM BRINGING WIDESPREAD RAIN FRIDAY NIGHT.
HOWEVER...SOME STORMS ARE POSSIBLE...AND ANY STORMS THAT DEVELOP
TO OUR WEST NEAR THE SURFACE LOW...WOULD HAVE MODERATE SHEAR AND
1500+ J/KG OF CAPE TO WORK WITH. A COUPLE OF STRONG TO SEVERE
STORMS ARE POSSIBLE.
ON SUNDAY...THE UPPER LOW CURRENTLY OVER NORTHWEST CANADA WILL
PUSH INTO THE CENTRAL PLAINS AND DRIVE A COLD FRONT SOUTHWARD. THE
UPPER LOW CURRENTLY OVER THE CENTRAL PACIFIC OCEAN WILL BE MOVING
ONSHORE CENTRAL CALIFORNIA AT THE SAME TIME. AS THE MAIN FORCING
OF THE NORTHERN UPPER LOW SHIFTS EAST...MODELS NOW ADVERTISE THE
COLD FRONT STALLING IN OKLAHOMA...DUE TO THE APPROACHING TROUGH
FROM THE WEST. PREVIOUS MODEL RUNS BROUGHT THE FRONT THROUGH THE
CWA AND HAD TO ADJUST POPS NORTHWARD AND KEEP THE HIGHEST POPS
NORTH OF THE I-20 CORRIDOR...CLOSEST TO THE STALLED FRONTAL
BOUNDARY.
THIS FRONT WILL QUICKLY SURGE NORTHWARD SUNDAY NIGHT AS THE WEST
COAST UPPER LOW PUSHES EAST. HOWEVER...AT THE SAME TIME...ANOTHER
IMPULSE ON THE BACKSIDE OF THE NORTHERN UPPER LOW WILL PUSH
THROUGH THE PLAINS...DRIVING A STRONGER FRONT SOUTH MONDAY. MODELS
ARE FASTER WITH THIS FRONT...SWEEPING IT THROUGH THE CWA MONDAY
AFTERNOON AND EVENING. WITH THIS QUICKER TIMING...HAD TO DECREASE
TEMPERATURES MONDAY NIGHT AND TUESDAY.
MAJOR DISCREPANCIES BETWEEN THE GFS AND ECMWF ARE APPARENT FOR
TUESDAY WITH THE HANDLING OF THE WEST COAST TROUGH. MODELS ARE
CONSISTENT WITH THE WEAKENING OF THE LOW...BUT THE ECMWF IS MOST
AGGRESSIVE WITH THIS WEAKENING TREND...AND MOVES IT THROUGH THE
AREA WEDNESDAY. THE GFS IS A BIT STRONGER THAN THE ECMWF AND
BRINGS THE TROUGH THROUGH TUESDAY WITH MORE PRECIP. THE ECMWF
WOULD THUS HAVE LESS PRECIP AS MOISTURE WOULD BE SCOURED OUT
BEHIND THE FRONT GIVEN THE LATER TIMING. NEVERTHELESS...WITH BOTH
MODELS WEAKENING THE LOW...WIDESPREAD RAIN CHANCES FOR TUESDAY
DONT APPEAR AS HIGH AS YESTERDAY. TEMPERATURES TUESDAY AND
WEDNESDAY BEHIND THE FRONT WILL BE IN THE 50S FOR HIGHS AND
30S/40S FOR LOWS.
HAMPSHIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 69 57 72 59 76 / 5 10 10 20 30
WACO, TX 70 57 73 59 75 / 5 5 10 10 20
PARIS, TX 68 54 69 58 72 / 5 20 20 20 30
DENTON, TX 68 55 72 57 76 / 5 10 20 30 30
MCKINNEY, TX 68 55 69 58 74 / 5 10 20 20 30
DALLAS, TX 71 57 73 59 75 / 5 10 10 20 30
TERRELL, TX 69 55 71 59 73 / 5 5 10 20 30
CORSICANA, TX 70 56 71 59 73 / 5 5 10 10 30
TEMPLE, TX 70 56 72 59 76 / 5 5 10 10 20
MINERAL WELLS, TX 71 55 73 56 80 / 5 10 10 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 PM CDT THU MAR 28 2013
.SHORT TERM...TONIGHT THROUGH SUNDAY
345 PM CDT THU MAR 28 2013
AT 3 PM...A 1028 MB SURFACE HIGH WAS CENTERED OVER SOUTHEAST
MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN. DESPITE
THIS HIGH PRESSURE AREA...A BROKEN DECK OF MID CLOUDS WERE LOCATED
ACROSS THIS AFOREMENTIONED AREA. THIS WAS DUE TO MODERATE WARM AIR
ADVECTION AHEAD OF A SHORT WAVE MOVING THROUGH SOUTHWEST MINNESOTA.
OVERALL THE 28.17Z RAP MODEL IS HANDLING THESE CLOUDS THE BEST.
THEY SHOW THAT THESE MID CLOUDS WILL MOVE SOUTHEAST OUT OF THE
AREA BY 29.03Z...AND THEN SOME MORE MID CLOUDS WILL MOVE BACK INTO
THE AREA FROM WESTERN MINNESOTA AND DAKOTAS AFTER 29.06Z. THESE
CLOUDS ARE THE RESULT OF SOME WARM AIR ADVECTION AHEAD OF YET
ANOTHER SHORT WAVE TROUGH MOVING OUT OF NORTH DAKOTA. SOUNDINGS
SUGGEST THAT THIS MOISTURE WILL LIMITED TO A 100 TO 150 MB LAYER
AROUND 700 MB. AS A RESULT...NOT EXPECTING ANY PRECIPITATION FROM
THIS WAVE. THIS IS IN DESPITE THE GFS TRYING TO GENERATE SOME
PRECIPITATION JUST UPSTREAM OF THE FORECAST AREA.
FROM LATE FRIDAY NIGHT INTO SATURDAY EVENING...A STRONG SHORT WAVE
TROUGH WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA. AHEAD OF
THIS WAVE...THERE WILL BE MODERATE TO STRONG 290K ISENTROPIC
LIFT...AND MODERATE 925 MB TO 850 MB MOISTURE TRANSPORT. THIS WILL
RESULT IN THE DEVELOPMENT OF A BAND OF RAIN ALONG AND AHEAD OF
THIS FRONT. INSTABILITY STILL LOOKS LIMITED WITH MOST UNSTABLE
CAPES CLIMBING UP TO 100 J/KG. AS A RESULT...LEFT ISOLATED
THUNDERSTORMS IN THE FORECAST MAINLY ALONG AND SOUTH OF INTERSTATE
90. TEMPERATURES AT THE ONSET OF THIS PRECIPITATION MAY RESULT IN
A BRIEF WINTRY MIX OF FREEZING RAIN AND SLEET MAINLY NORTHEAST OF
INTERSTATE 94. THERE MAY BE A BRIEF PERIOD OF GLAZING. HOWEVER...
IT WILL SHORT-LIVED AS TEMPERATURES CLIM QUICKLY INTO THE 40S.
ON SUNDAY...A STRONG CANADIAN COLD FRONT WILL MOVE SOUTHEAST
THROUGH THE FORECAST AREA. THERE IS VERY LITTLE 925 AND 850 MB
MOISTURE TRANSPORT ASSOCIATED WITH THIS FRONT. IN THE WAKE OF THIS
FRONT...THERE WILL BE MODERATE 290K ISENTROPIC LIFT. HOWEVER
SUBSIDENCE IN THE WAKE OF THIS FRONT WILL CAUSE CONDENSATION
PRESSURE DEFICITS TO RISE INTO THE 50 TO 100 MB RANGE. AS A
RESULT...THERE IS A QUESTION ON WHETHER THERE WILL BE ENOUGH
MOISTURE FOR ANY RAIN AND SNOW SHOWERS DURING THE AFTERNOON AND
EVENING...THUS...KEPT PRECIPITATION CHANCES ON THE LOW SIDE MAINLY
NORTH OF INTERSTATE 94.
.LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY
345 PM CDT THU MAR 28 2013
FROM SUNDAY NIGHT INTO TUESDAY...IT CONTINUES TO LOOK LIKE
ANOMALOUS COLD AIR MASS WILL BE LOCATED ACROSS THE AREA. THE ECMWF
850 TEMPERATURES ARE RUNNING 1 TO 1.5 STANDARD DEVIATIONS BELOW
NORMAL ON MONDAY...AND AROUND 1 STANDARD DEVIATION BELOW NORMAL ON
TUESDAY. THIS WILL RESULT IN HIGH TEMPERATURES IN THE LOWER AND
MID 30S ON MONDAY...AND IN THE MID AND UPPER 30S ON TUESDAY.
ON WEDNESDAY...ANOTHER COLD FRONT WILL MOVE SOUTHEAST THROUGH THE
REGION. AT THIS TIME...IT LOOKS LIKE THE BEST MOISTURE AND LIFT
WILL BE TO OUR NORTH...THUS KEPT THE FORECAST DRY.
LOOKING AHEAD TO THE FIRST HALF OF APRIL...THE CFS VERSION 2
CONTINUES TO SHOW THAT THE AREA WILL SEE PREDOMINANTLY NORTHWEST
FLOW. AS A RESULT...IT CONTINUES TO SHOW COLDER-THAN-NORMAL
TEMPERATURES PERSISTING THROUGH THIS TIME PERIOD. THE MAIN REASON
FOR THIS IS THAT THE ARCTIC OSCILLATION REMAINS NEGATIVE.
&&
.AVIATION...THROUGH 18Z FRIDAY
1150 AM CDT THU MAR 28 2013
LIFT AHEAD OF A WEAK UPPER LEVEL TROUGH WAS PRODUCING A BAND OF
ALTOCUMULUS IN THE 7-8KFT RANGE ACROSS SOUTHERN MN INTO NORTHEAST
IA. THIS TROUGH AND ASSOCIATED MID CLOUD WILL PROGRESS EASTWARD
ACROSS THE AREA THIS AFTERNOON AND EXITS EAST BY LATER THIS
EVENING. SNOWMELT/LOWER BOUNDARY LAYER MOISTURE LOADING TODAY MAY
SET THE STAGE FOR SOME 3-5SM BR ACROSS THE AREA OVERNIGHT/EARLY
FRIDAY MORNING UNDER PARTLY CLOUDY SKIES. ANOTHER UPPER LEVEL
TROUGH AND WARM AIR ADVECTION IS EXPECTED TO PRODUCE SOME MID-
CLOUD AGAIN OVERNIGHT INTO FRIDAY MORNING. DEPENDING ON HOW THICK
THIS CLOUD WILL BE WILL HAVE A BEARING ON FOG PRODUCTION. THE
THICKER THE CLOUD...THE LESS LIKELY FOR FOG PRODUCTION. WILL
ASSESS THIS CLOSELY FOR THE 18Z TAF ISSUANCE.
&&
.HYDROLOGY...
345 PM CDT THU MAR 28 2013
DUE TO A MELTING SNOWPACK OVER THE LAST SEVERAL DAYS...MANY RIVERS
ACROSS NORTHEAST IA/SOUTHEAST MN/AND SOUTHWEST WI HAVE EXPERIENCED
WITHIN BANK RISES OF 2 TO 4 FEET. IN AREAS WHERE THE SNOW HAS MELTED...
SOME OF THE FROST HAS MELTED IN THE TOP FEW INCHES OF THE SOIL...THIS
IS ALLOWING SOME OF THE SNOW MELT TO GET INTO THE TOP SOILS. THIS
MOISTURE THEN FREEZES IN THE TOP SOILS AT NIGHT. THIS IS LIMITING
THE AMOUNT OF RUNOFF INTO THE RIVERS.
ON SATURDAY...LOOK FOR A QUARTER TO HALF INCH OF RAIN. THIS WILL
ADD ONTO THE RUNOFF FROM THE SNOW MELT. HOWEVER THE WARM RAINS
WILL HELP TO MELT SOME FROST IN THE TOP SOILS...SO NOT LOOKING FOR
COMPLETE RUNOFF LIKE WE HAD EARLIER IN THE MONTH.
WHILE NO FLOODING IS EXPECTED AT THIS TIME...PEOPLE LIVING NEAR
OR HAVING INTERESTS ALONG RIVER WAYS ARE URGED TO MONITOR LATEST
RIVER FORECASTS AND STATEMENTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
243 PM CDT THU MAR 28 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DAS
HYDROLOGY...DAS/BOYNE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 247 PM CDT THU MAR 28 2013
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE
HIGH PRESSURE STRETCHING FROM THE SOUTHEAST GULF COAST TO THE
WESTERN GREAT LAKES TO HUDSON BAY EARLY THIS AFTERNOON. MOSTLY
CLEAR SKIES PREVAIL ACROSS MUCH OF THE STATE AS TEMPERATURES CLIMB
INTO THE UPPER 30S TO MID 40S. MEANWHILE OUT WEST...A THIN BAND OF
ALTO-STRATUS HAS BEEN SLOWLY FALLING APART TODAY...WHICH IS ALIGNED
ALONG A WEAK 850MB BAROCLINIC ZONE. A SOUTHEAST MOVING SHORTWAVE
OVER NORTHERN MINNESOTA HAS BEEN BENIGN SO FAR...BUT STARTING TO GET
A FEW CU POPPING OVER THE HIGHER TERRAIN OF UPPER MICHIGAN WHICH ARE
SPREADING SOUTH. 12Z SOUNDINGS ACROSS THE REGION ARE PRETTY DRY...AND
DEWPOINTS HAVE FALLEN INTO THE LOWER TEENS OVER N-C WISCONSIN. WILL
STILL TAKE DOWN SKY COVER A COUPLE NOTCHES THROUGH THE REST OF THE
AFTERNOON. TEMPS AND CLOUDS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...WEAK SHORTWAVE WILL MOVE ACROSS NORTHEAST WISCONSIN
WITHOUT MUCH OF AN IMPACT. A RATHER DRY MOISTURE PROFILE WITHIN THE
12Z SOUNDINGS ACROSS THE REGION SUGGEST THERE IS LITTLE HOPE FOR
CLOUD COVER SO WILL DROP WORDING INTO THE MOSTLY CLEAR CATEGORY
EVERYWHERE. WITH HIGH PRESSURE AND LIGHT WINDS AT THE
SURFACE...MOSTLY CLEAR SKIES WILL CAUSE TEMPS TO FALL SIMILAR TO
LAST NIGHTS. SO USED MAINLY PERSISTENCE FOR LOW TEMPS FOR THIS
FORECAST...AND BLENDED IN THE ORIGINAL FORECAST TO GIVE THEM A
COUPLE DEGREES BUMP SINCE AFTERNOON HIGHS WILL BE A TAD WARMER THAN
YESTERDAYS.
FRIDAY...HIGH PRESSURE WILL REMAIN ACROSS THE AREA WHICH WILL LEAD
TO A MOSTLY SUNNY DAY. WEAK WARM ADVECTION WILL ARRIVE OVER CENTRAL
WISCONSIN IN THE AFTERNOON...AND MAY PUSH A FEW CLOUDS INTO THAT
AREA. OTHERWISE...TEMPS SHOULD BE A COUPLE MORE DEGREES WARMER THAN
TODAY...AND WILL GO WITH HIGHS IN THE MID TO UPPER 40S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 247 PM CDT THU MAR 28 2013
THE LARGE SCALE PATTERN SHOWS A DEVELOPING UPR RDG
OVER THE WRN CONUS AND A GENERAL MEAN TROFFING FROM THE PLAINS TO
THE MID-ATLANTIC STATES. THERE ARE SIGNS THAT THIS PATTERN WL
BREAK DOWN LATER NEXT WEEK AS A NEW UPR TROF HEADS TOWARD THE WEST
COAST AND SHOVES THE WRN CONUS UPR RDG EWD INTO THE ROCKIES. MAIN
WEATHER FEATURES TO IMPACT NE WI WL BE THE PASSAGE OF A SHORTWAVE
TROF/CDFNT THIS WEEKEND AND A POLAR VORTEX SWINGING THRU NRN
SECTIONS OF THE GREAT LAKES EARLY NEXT WEEK. TEMPS TO PEAK ON SAT...
DROP TO WELL BELOW NORMAL MON...AND RECOVER TO NEAR NORMAL BY NEXT
THU.
CLOUDS WL STEADILY BE ON THE INCREASE FRI NGT AS THE SFC HI MOVES
TOWARD THE ERN GREAT LAKES AND A SHORTWAVE TROF/CDFNT COMBINATION
PUSHES E-SE INTO THE UPR MS VALLEY. A PREVAILING SW FLOW ALOFT WL
HELP TO INCREASE MOISTURE INTO WI ALONG WITH WAA. THE GFS APPEARS
TO SPREAD THE PCPN TOO FAR EAST (INTO FAR NE WI) BY DAYBREAK
CONSIDERING THE STRONGEST LIFT TO STILL BE OVER S-CNTRL MN TO NW
WI. THEREFORE...PREFER TO FOLLOW THE MAJORITY MDL SOLUTION OF
BRINGING THE LEADING EDGE OF PCPN TOWARD CNTRL WI BY 12Z SAT. ONLY
CONCERN WOULD BE PCPN TYPE DUE TO SFC TEMPS STILL EXPECTED TO BE
BELOW THE FREEZING MARK. N-CNTRL WI COULD SEE A BRIEF PERIOD OF A
WINTRY MIX BEFORE TEMPS WARM UP ENUF PAST SUNRISE. EXPECT TEMPS
OVER CNTRL WI TO BOTTOM OUT SHORTLY AFTER MIDNGT AND THEN EITHER
STEADY OUT OR EVEN RISE A COUPLE OF DEGS. ERN WI SHOULD REACH A
TYPICAL SUNRISE MIN TEMP IN THE UPR 20S TO LWR 30S.
THE SHORTWAVE TROF/CDFNT REACH THE WRN GREAT LAKES ON SAT WITH A
SWATH OF MAINLY RAIN ACROSS THE FCST AREA. ONCE AGAIN...NRN WI MAY
SEE MIXED PCPN CARRY OVER TIL AROUND MID-MORNING BEFORE THE
ATMOSPHERIC COLUMN WARMS ENUF TO SUSTAIN ALL LIQUID. MDLS ALL
POINT 0.25-0.50" OF QPF OVER CNTRL WI BY 00Z SUNDAY AND MAY NEED
TO RAISE POPS EVEN MORE. ALL THE CLOUDS AND PCPN WL LIMIT DAYTIME
WARMING WITH MOST OF NE WI REACHING THE MID TO UPR 40S.
SHORTWAVE TROF/CDFNT PUSH THRU THE REST OF WI PRIMARILY DURING SAT
EVENING WITH PCPN CHCS DIMNISHING UPON FROPA. ERN WI TO HAVE THE
HIGHEST POPS (LIKELY)...WHILE N-CNTRL WI TO ONLY HAVE A LOW-END
CHC POP. AS COLDER AIR RUSHES INTO WI BEHIND THE FNT...THE RAIN WL
MIX WITH OR CHANGE TOTALLY TO ALL LIGHT SNOW. MDLS DO SHOW SOME
SUBSIDENCE BUILDING THRU CNTRL WI AFTER MIDNGT...THUS ANY LINGERING
POPS TO BE RELEGATED TO N-CNTRL WI AND ERN WI.
TIMING ISSUES WITH BOTH THE POLAR VORTEX AND SECONDARY CDFNT MAKE
SUNDAY`S FCST DIFFICULT AT BEST. THE POLAR VORTEX LOCATION RANGES
FROM THE ERN TIP OF LAKE SUPERIOR (GEM) TO SW ONTARIO (GFS) TO
WEST OF JAMES BAY (NAM). THIS TIMING DIFFERENCE IS IMPORTANT
BECAUSE THIS FEATURE WL HELP TO DRIVE THE CDFNT THRU NE WI EITHER
SUNDAY MORNING WITH FALLING AFTERNOON TEMPS OR LATER SUNDAY
AFTERNOON WITH TEMPS ABLE TO REACH THE UPR 30S TO LWR 40S. SINCE
MODELS CONT TO WAFFLE WITH THE TIMING ASPECT...FEEL A COMPROMISE
SOLUTION WOULD WORK BEST WITH A LATER MORNING TO EARLY AFTERNOON
FROPA ACCOMPANIED BY EITHER SOME RAIN OR SNOW SHWRS. WINDS WL ALSO
STEADILY INCREASE THRU THE DAY AND BECOME RATHER BLUSTERY AT TIMES
ONCE THE FNT PASSES THRU.
THE WRN GREAT LAKES TO THEN BE LOCKED IN A COLD...CYCLONIC FLWO
SUNDAY NGT INTO MON AS THE POLAR VORTEX SWINGS ACROSS SRN ONTARIO
INTO SRN QUEBEC. CAA CONTS TO POUR INTO WI AS WINDS VEER MORE TO
THE NW AND 8H TEMPS DROP INTO THE LWR TO MID TEENS BELOW ZERO (C).
THIS LEADS TO THE POSSIBILITY OF LAKE EFFECT SNOW SHWRS OVER N-CNTRL
WI WITH A MINOR ACCUMULATION IN THE FAVORED SNOWBELT OF VILAS CNTY.
CANNOT RULE OUT A FEW SNOW SHWRS OVER THE REST OF THE FCST AREA ON
MON AS LAPSE RATES STEEPEN AND INSTABILITY INCREASES. AN UNSEASONABLY
COOL AND BLUSTERY SPRING DAY ON TAP FOR MON WITH MAX TEMPS TO EASILY
BE 15 TO 20 DEGS BELOW NORMAL.
SNOW SHWR THREAT FROM LAKE SUPERIOR COULD LINGER OVER N-CNTRL WI
RIGHT INTO TUE DEPENDING ON HOW FAST A RDG OF HI PRES BUILDS EWD
FROM THE PLAINS. FOR NOW...HAVE KEPT A SMALL POP MAINLY FOR VILAS
CNTY MON NGT INTO TUE. THE REST OF NE WI WL REMAIN DRY (OTHER THAN
A FEW PASSING FLURRIES MON NGT) WITH A MIX OF SUNY AND CLOUDS ON
TUE. TEMPS SHOULD BEGIN A SLOW MODERATING TREND AS THE CORE OF THE
COLDEST AIR SHIFTS OFF TO THE EAST.
LONG-TERM MDLS ALSO DISAGREE ON WHEN TO SEND THIS SFC RDG THRU THE
WRN GREAT LAKES HEADED TOWARD THE MIDDLE OF NEXT WEEK WITH THE GFS
ALMOST 12 HOURS FASTER THAN THE ECMWF. WHILE THIS DIFFERENCE WOULD
NOT IMPACT THE DRY WEATHER EXPECTED...IT WOULD AFFECT BOTH WIND
DIRECTION AND MAX TEMPS. HAVE AGAIN SPLIT THE DIFFERENCE WITH
WINDS BACKING S-SW WED AFTERNOON. MDLS NOW BRING A QUICK-MOVING
CLIPPER SYSTEM ACROSS SRN CANADA WITH A CDFNT RACING THRU WI WED
NGT. GULF MOISTURE IS CUT-OFF...THUS ANY PCPN APPEARS TO BE VERY
LIGHT AND SCATTERED AT BEST.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 247 PM CDT THU MAR 28 2013
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD.
SCT-BKN CUMULUS/STRATOCUMULUS IS EXPECTED TO DEVELOP OVER MAINLY NC/NE
WI THIS AFTERNOON/EARLY EVG...AS AN UPPER LEVEL DISTURBANCE MOVES
THROUGH. ASIDE FROM SOME PATCHY MVFR/IFR VSBYS IN FOG OVER NC/C WI
LATE THU NGT...VFR CONDITIONS ARE ANTICIPATED THROUGH THE TAF
PERIOD.
&&
.HYDROLOGY...
ISSUED AT 247 PM CDT THU MAR 28 2013
EXPECT A GRADUAL MODERATION IN TEMPERATURES FOR THE REST OF THE
WEEK...WITH HIGHS REACHING INTO MID TO UPPER 40S OVER THE FORECAST
AREA ON FRIDAY AND SATURDAY. THIS WILL CONTINUE THE GRADUAL
MELTING OF THE SNOWPACK. RAIN OR MIXED PCPN IS EXPECTED THIS
WEEKEND...BUT PCPN AMOUNTS SHOULD ONLY BE AROUND A QUARTER INCH.
GIVEN THIS SCENARIO...THE EXPECTED RUNOFF SHOULD ONLY CAUSE A
GRADUAL RISE IN THE RIVERS OVER CENTRAL AND EAST CENTRAL WISCONSIN
BY THE WEEKEND. &&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......MPC
HYDROLOGY......MPC