Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/30/13
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
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 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...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
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
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 PITTSBURGH PA
957 PM EDT FRI MAR 29 2013
.SYNOPSIS...
A SURFACE HIGH WILL CROSS THE AREA TONIGHT AND PUSH EASTWARD ON
SATURDAY. THIS WILL ALLOW FOR UNSEASONABLY COLD TEMPERATURES
TONIGHT WITH ABUNDANT SUNSHINE ALLOWING FOR TEMPERATURES TO
WARM CLOSER TO SEASONAL NORMALS ON SATURDAY. ANOTHER STRONGER
FRONT WILL BRING MUCH COLDER TEMPERATURES WITH RAIN AND SNOW
SHOWERS MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
A QUICK UPDATE HAS BEEN ISSUED TO REDUCE CLOUD COVERAGE AND
ACCOUNT FOR THE LATEST TRENDS IN TEMPS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A DRY...NORTHWESTERLY 500MB FLOW. AT THE SURFACE...HIGH
PRESSURE IS CENTERED ACROSS THE OHIO/INDIANA BORDER WITH A WEAK
PRESSURE GRADIENT ACROSS THE UPPER OHIO VALLEY. SKIES HAVE MOSTLY
CLEARED WITH THE LOSS OF HEATING TONIGHT.
TONIGHT AND SATURDAY...THE SURFACE HIGH WILL SLOWLY SLIDE
EASTWARD...CENTERED ACROSS THE AREA BY AROUND 12Z SATURDAY AND
PUSHING INTO CENTRAL PA BY SATURDAY AFTERNOON. A DEEP LAYER OF DRY
AIR ALOFT WILL SUPPORT SKIES CLEARING QUICKLY OVERNIGHT. NEARLY
CALM WINDS ALONG WITH CLEAR SKIES AND DEW POINTS IN THE UPPER TEENS TO
LOWER 20S SUPPORT A STRONG RADIATIONAL COOLING NIGHT. THUS...LOWS
TONIGHT ARE 3-5 DEGREES COOLER THAN A MAV/MET BLEND IN MOST
LOCATIONS. ASIDE FROM SCATTERED DIURNAL CU DEVELOPING ON
SATURDAY...ABUNDANT SUNSHINE CAN BE EXPECTED. TEMPS ON SATURDAY ARE
FORECAST TO WARM ABOVE SEASONAL NORMS FOR HIGHS FOR THE FIRST TIME
IN MANY LOCATIONS SINCE MARCH 15TH. HIGHS WILL RANGE FROM THE
UPPER 50S SOUTHWEST OF PITTSBURGH TO THE UPPER 40S FOR THE EASTERN
RIDGES.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MODELS IN GOOD OVERALL AGREEMENT ON NEXT SYSTEM TO MOVE ACROSS
THE GREAT LAKES SUNDAY WITH A COLD FRONT SWEEPING ACROSS THE UPPER
OHIO VALLEY BY SUNDAY EVENING. CLOUDS WILL BE INCREASING SATURDAY
NIGHT WITH BULK OF RAIN WITH FRONT FALLING SUNDAY MORNING INTO MID
AFTERNOON. DOES NOT APPEAR TO BE ENOUGH LOW LEVEL INSTABILITY TO
INCLUDE ANY MENTION OF THUNDER WITH FRONT.
SUNDAY NIGHT NEXT STRONGER FRONT WILL BE APPROACHING AS YET
ANOTHER STRONG AND COLD VORTEX MOVES SOUTH AND SITS JUST NORTH OF
THE GREAT LAKES. THIS FRONT WILL ENTER THE REGION MONDAY MORNING
AND SLOWLY SINK SOUTHEAST AS THE DAY PROGRESSES. 850MB
TEMPERATURES WILL FALL BY LATE AFTERNOON TO AT LEAST -3C AT THE
MASON DIXON LINE TO -10C ACROSS THE I-80 CORRIDOR WITH THE NAM
MODEL EVEN COLDER. WITH THIS LIKELY POPS WERE MAINTAINED WITH MIXED
RAIN AND SNOW SHOWERS WHICH COULD BE ALL SNOW BY LATE AFTERNOON.
FOLLOWED A FAIRLY CLOSE BLEND OF MODEL MOS UNTIL MONDAY WHEN
GUIDANCE WAS UNDERCUT DUE TO PRECIP AND STRONG COLD ADVECTION.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLD ADVCTN IN THE WAKE OF THE FRONT WL CHANGE ANY RESIDUAL SHRA TO
SHSN...CHCS FOR WHICH MAY PERSIST THRU TUE AS SHRTWVS MOV THRU THE
BASE OF A BROAD LOW PROJECTED TO BE CENTERED OVR QUEBEC. THAT LOW
WL MAINTAIN SUBAVERAGE TEMPS FOR THE FIRST HALF OF THE WEEK.
MDL-PROGGED SHRTWV RIDGE IN ADVN OF A PLAINS-TROF IS EXPECTED TO
SPPRT A DRY FORECAST FOR MIDWEEK WITH TEMP MODERATION BACK TWD THE
SEASONAL AVERAGES. HOWEVER...EWD PROGRESS OF THAT TROF WL INCRS
POPS FOR THE CLOSE OF THE WORK WEEK.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
VFR IS EXPECTED FOR NEARLY THE ENTIRE TAF PERIOD. HOWEVER...WITH
NEARLY CALM WINDS EXPECTED TONIGHT...SOME MVFR FOG CANNOT BE RULED
OUT IN LOCATIONS THAT ALREADY HAVE HIGHER DEWPOINTS. HAD ENOUGH
CONFIDENCE TO INCLUDE TEMPO MVFR AT ZZV...WITH LESS CONFIDENCE FOR
FKL AND DUJ. SOME ADDITIONAL SCATTERED DIURNAL CU IS POSSIBLE ON
SATURDAY. WINDS WILL BE LESS THAN 10 KTS OUT OF THE WEST-SOUTHWEST.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
THE NXT CHC FOR WIDESPREAD RESTRICTIONS WL COME WITH...AND IN THE
WAKE OF A SUNDAY CDFNT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...TGREEN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
818 PM EDT FRI MAR 29 2013
.SYNOPSIS...
A SURFACE HIGH WILL CROSS THE AREA TONIGHT AND PUSH EASTWARD ON
SATURDAY. THIS WILL ALLOW FOR UNSEASONABLY COLD TEMPERATURES
TONIGHT WITH ABUNDANT SUNSHINE ALLOWING FOR TEMPERATURES TO
WARM CLOSER TO SEASONAL NORMALS ON SATURDAY. ANOTHER STRONGER
FRONT WILL BRING MUCH COLDER TEMPERATURES WITH RAIN AND SNOW
SHOWERS MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
00Z ENHANCED SHORT TERM FORECAST HAS BEEN ISSUED TO REDUCE CLOUD
COVERAGE AND TO DECREASE OVERNIGHT LOWS BY 1-2 DEGREES.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A DRY...NORTHWESTERLY 500MB FLOW. AT THE SURFACE...HIGH
PRESSURE IS CENTERED ACROSS THE OHIO/INDIANA BORDER WITH A WEAK
PRESSURE GRADIENT ACROSS THE UPPER OHIO VALLEY. DIURNAL CUMULUS
CLOUDS ARE QUICKLY DIMINISHING WITH THE LOSS OF HEATING THIS
EVENING.
TONIGHT AND SATURDAY...THE SURFACE HIGH WILL SLOWLY SLIDE
EASTWARD...CENTERED ACROSS THE AREA BY AROUND 12Z SATURDAY AND
PUSHING INTO CENTRAL PA BY SATURDAY AFTERNOON. A DEEP LAYER OF DRY
AIR ALOFT WILL SUPPORT SKIES CLEARING QUICKLY OVERNIGHT. NEARLY
CALM WINDS ALONG WITH CLEAR SKIES AND DEW POINTS IN THE UPPER TEENS TO
LOWER 20S SUPPORT A STRONG RADIATIONAL COOLING NIGHT. THUS...LOWS
TONIGHT ARE 3-5 DEGREES COOLER THAN A MAV/MET BLEND IN MOST
LOCATIONS. ASIDE FROM SCATTERED DIURNAL CU DEVELOPING ON
SATURDAY...ABUNDANT SUNSHINE CAN BE EXPECTED. TEMPS ON SATURDAY ARE
FORECAST TO WARM ABOVE SEASONAL NORMS FOR HIGHS FOR THE FIRST TIME
IN MANY LOCATIONS SINCE MARCH 15TH. HIGHS WILL RANGE FROM THE
UPPER 50S SOUTHWEST OF PITTSBURGH TO THE UPPER 40S FOR THE EASTERN
RIDGES.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MODELS IN GOOD OVERALL AGREEMENT ON NEXT SYSTEM TO MOVE ACROSS
THE GREAT LAKES SUNDAY WITH A COLD FRONT SWEEPING ACROSS THE UPPER
OHIO VALLEY BY SUNDAY EVENING. CLOUDS WILL BE INCREASING SATURDAY
NIGHT WITH BULK OF RAIN WITH FRONT FALLING SUNDAY MORNING INTO MID
AFTERNOON. DOES NOT APPEAR TO BE ENOUGH LOW LEVEL INSTABILITY TO
INCLUDE ANY MENTION OF THUNDER WITH FRONT.
SUNDAY NIGHT NEXT STRONGER FRONT WILL BE APPROACHING AS YET
ANOTHER STRONG AND COLD VORTEX MOVES SOUTH AND SITS JUST NORTH OF
THE GREAT LAKES. THIS FRONT WILL ENTER THE REGION MONDAY MORNING
AND SLOWLY SINK SOUTHEAST AS THE DAY PROGRESSES. 850MB
TEMPERATURES WILL FALL BY LATE AFTERNOON TO AT LEAST -3C AT THE
MASON DIXON LINE TO -10C ACROSS THE I-80 CORRIDOR WITH THE NAM
MODEL EVEN COLDER. WITH THIS LIKELY POPS WERE MAINTAINED WITH MIXED
RAIN AND SNOW SHOWERS WHICH COULD BE ALL SNOW BY LATE AFTERNOON.
FOLLOWED A FAIRLY CLOSE BLEND OF MODEL MOS UNTIL MONDAY WHEN
GUIDANCE WAS UNDERCUT DUE TO PRECIP AND STRONG COLD ADVECTION.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLD ADVCTN IN THE WAKE OF THE FRONT WL CHANGE ANY RESIDUAL SHRA TO
SHSN...CHCS FOR WHICH MAY PERSIST THRU TUE AS SHRTWVS MOV THRU THE
BASE OF A BROAD LOW PROJECTED TO BE CENTERED OVR QUEBEC. THAT LOW
WL MAINTAIN SUBAVERAGE TEMPS FOR THE FIRST HALF OF THE WEEK.
MDL-PROGGED SHRTWV RIDGE IN ADVN OF A PLAINS-TROF IS EXPECTED TO
SPPRT A DRY FORECAST FOR MIDWEEK WITH TEMP MODERATION BACK TWD THE
SEASONAL AVERAGES. HOWEVER...EWD PROGRESS OF THAT TROF WL INCRS
POPS FOR THE CLOSE OF THE WORK WEEK.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR IS EXPECTED FOR NEARLY THE ENTIRE TAF PERIOD. HOWEVER...WITH
NEARLY CALM WINDS EXPECTED TONIGHT...SOME MVFR FOG CANNOT BE RULED
OUT IN LOCATIONS THAT ALREADY HAVE HIGHER DEWPOINTS. HAD ENOUGH
CONFIDENCE TO INCLUDE TEMPO MVFR AT ZZV...WITH LESS CONFIDENCE FOR
FKL AND DUJ. SOME ADDITIONAL SCATTERED DIURNAL CU IS POSSIBLE ON
SATURDAY. WINDS WILL BE LESS THAN 10 KTS OUT OF THE WEST-SOUTHWEST.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
THE NXT CHC FOR WIDESPREAD RESTRICTIONS WL COME WITH...AND IN THE
WAKE OF A SUNDAY CDFNT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...TGREEN
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
726 PM CDT FRI MAR 29 2013
.UPDATE...
00Z AVIATION DISCUSSION ADDED BELOW.
&&
.PREV DISCUSSION...
/ISSUED 356 PM CDT FRI MAR 29 2013/
TEMPERATURES HAVE REALLY RAMPED UP THIS AFTERNOON...ACROSS MUCH
OF THE CWA...AS SUFFICIENT MIXING HAS OCCURRED WITH LIGHT SE
FLOW COUPLED WITH ABUNDANT DIFFUSE SUNSHINE. READINGS RANGE FROM
THE LOW TO MID 40S OVER CENTRAL MN AND WE CENTRAL WI TO THE MID
TO UPPER 50S ACROSS THE FAR SOUTH AND SW. WEAK SURFACE CYCLONE
OVER CENTRAL SODAK AND NORTHERN NE WILL SLOWLY MOVE EAST AND
WEAKEN INTO A SURFACE TROUGH BY DAWN ON SATURDAY. GFS40...EUROPEAN
AND NAM GUIDANCE ALL INDICATING A PRECIPITATION EVENT BEGINNING
OVER MUCH OF THE FA BY MIDNIGHT AND ENDING BY SATURDAY AFTN.
USED GFS40 295K ISENTROPIC SFC...AND THETA E ADVECTION SIGNATURE
TO PLACE TIMING AND CHANCES FOR PCPN. 850 TEMPS CONFIRMING AN ALMOST
ALL LIQUID EVENT FA WIDE...SAVE THE FAR NORTHERN PERIPHERY...WHERE A
VERY LIGHT FREEZING RAIN WINDOW MAY OCCUR BETWEEN 09 AND 12Z. NOT
EXPECTING ANY SIGNIFICANT ICE ACCUMULATIONS DUE TO SHORT WINDOW OF
BELOW FREEZING TEMPERATURES. AN LI TONGUE IS ALSO POINTING TO
POSSIBLE ISOLATED THUNDERSTORMS AFTER MIDNIGHT AND INTO SAT MORNING
OVER PORTIONS OF THE SOUTHERN FA. EVAPORATING SNOWFALL THIS
AFTERNOON COUPLED WITH A VERY WEAK WIND REGIME AFTER MIDNIGHT
PROMPTED MENTION OF AT LEAST PATCHY FOG OVER MUCH OF FA. QPF
VALUES INDICATING A FEW TENTHS TO POSSIBLY AS MUCH AS FOUR TENTHS
OF AN INCH OF MOISTURE OVER FA...WITH HIGHEST AMOUNTS ANTICIPATED
OVER WEST CENTRAL WI.
A COLD FRONT WILL MARCH THROUGH SOUTHERN MN AND WEST CENTRAL
WI BY EARLY SUNDAY EVENING. LARGE POOL OF POLAR AIR BEHIND FRONTAL
BOUNDARY WILL PUSH TEMPERATURES BACK TO BETWEEN 15 AND 20 DEGREES
BELOW NORMAL FOR MONDAY AND TUESDAY. FAIRLY ROBUST PRESSURE GRADIENT
WILL DEVELOP OVER MUCH OF FA SUNDAY AFTERNOON INTO SUNDAY EVENING
AS 50H CLOSED LOW DIPS INTO THE GREAT LAKES REGION FROM SOUTHERN
ONTARIO. RETURN SW FLOW BEHIND A 1030MB SURFACE HIGH PRESSURE SYSTEM
WILL PROVIDE SLIGHTLY BELOW TO NEAR NORMAL HIGH TEMPERATURES OVER
THE FA STARTING ON WED...WITH SLOW WARMING CONTINUING INTO FRIDAY.
GFS40 INDICATING A WEAK SHORT WAVE TREKKING THROUGH CWA ON THUR
..SO INCLUDED A SLIGHT CHANCE POPS THIS TIME FRAME. 1000-500MB
THICKNESS VALUES POINTING TO A POSSIBLE RAIN SNOW MIX. A MUCH
BETTER PCPN SHIELD SIGNATURE INDICATED FOR THE FRIDAY/SATURDAY
TIME FRAME. ONCE AGAIN...THERMAL COLUMN INDICATING A RAIN SNOW
MIX FOR THE NORTHERN FA...WITH AN ALL RAIN SCENARIO REMAINDER.
BIG DIFFERENCE WITH LATE WEEK SYSTEM IS MUCH LARGER AMOUNT OF QPF
INDICATED. CUTTING BIAS OF OVERDOING PCPN IN HALF...CURRENT
FORECAST OF ONE HALF TO THREE QUARTERS OF AN INCH OF ADDED
MOISTURE DURING THIS TIME FRAME NOT OUT OF THE QUESTION.
&&
.AVIATION.../00Z TAF ISSUANCE/
MAIN CHANGE MADE IN 00Z TAFS WAS TO SPEED UP ARRIVAL OF RAIN A
COUPLE HOURS AT STC/AXN/RWF...WITH TIMING AT OTHER TERMINALS
REMAINING MORE OR LESS UNCHANGED. GIVEN STRONG AGREEMENT IN PRECIP
PLACEMENT AMONGST THE 4 MEMBERS OF THE HOPWRF...USED IT TO TIME
-SHRA ACROSS THE AREA WITH THE COLD FRONT. LITTLE WORRIED THAT
MSP/RWF MAY END UP SOUTH OF MORE ORGANIZED PRECIP...WITH THE RAP
SHOWING NOSE OF LLJ TRACKING ACROSS CENTRAL MN INTO NRN WI. EXPECT
-SHRA TO DEVELOP IN THE AXN AREA AROUND 3Z...THEN TRY TO BUILD
SOUTH INTO THE LLJ. OUTSIDE OF LINGERING FOG ISSUES IN THE RED
RIVER VALLEY...NOT SEEING MUCH IN THE WAY OF SUB-VFR CLOUDS ACROSS
THE DAKOTAS...SO NOT ANTICIPATING MVFR CONDS TO ARRIVE IN ERNEST
UNTIL PRECIP ARRIVES. EXPECT CIGS TO DROP BELOW 2K FT /AND POSSIBLY
BELOW 1K FT UP TOWARD AXN/ BEHIND THE FRONT...BUT NAM 925-850
LAYER RH FIELD INDICATES SKIES MAY SCT OUT ACROSS MN FAIRLY QUICKLY
BEHIND THE FRONT AS COLD AIR ADVECTION BEHIND THIS FRONT IS WEAK.
INSTEAD...SECONDARY BOUNDARY COMING THROUGH SATURDAY NIGHT LOOKS
TO BRING WITH IT THE STRONG COLD ADVECTION AND EXPANSIVE POST
FRONTAL STRATUS FIELD.
KMSP...INITIALLY HRRR WAS WANTING TO TAKE PRECIP NORTH OF THE
FIELD...THOUGH LAST SEVERAL RUNS HAVE COME IN LINE WITH OTHER HIGH
RES MODELS WITH PRECIP FILLING IN ALONG FRONT. PRETTY GOOD
AGREEMENT AMONGST MODELS WITH RAIN MOVING ACROSS THE FIELD BETWEEN
10Z AND 14Z. CONFIDENCE IN FORECAST BEHIND THE FORECAST IS LOW.
FAVORED FORECAST TOWARD THE OPTIMISTIC NAM GIVEN WEAK COLD
ADVECTION EXPECTED BEHIND THE FRONT...FEEL LAMP IS CONTINUING TO
OVERDO LOW LEVEL MOISTURE BASED ON WHAT IS OUT THERE NOW. WIND
FORECAST MAY REQUIRE MORE REFINING...BUT AT THE VERY LEAST...BOTH
THE LAMP AND RAP/HRRR HAVE SLOWED THE ARRIVAL OF THE FRONT AND NW
WINDS BY A COUPLE OF HOURS.
/OUTLOOK FOR KMSP/
SUN...MVFR CIGS POSSIBLE. WINDS NW 20G30KTS.
MON...MVFR CIGS POSSIBLE. WINDS NW 15G25KTS.
TUE...VFR. WIND NW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AJZ/MPG
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...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...UPDATED
NWS NORTH PLATTE NE
817 PM CDT FRI MAR 29 2013
.SYNOPSIS...
ISSUED AT 318 PM CDT FRI MAR 29 2013
H5 HAND ANALYSIS THIS MORNING IS INDICATING BROAD LOW
AMPLITUDE FLOW ACROSS THE LOWER 48...WITH EMBEDDED SHORTWAVES NOTED
OVER THE NORTHERN ROCKIES OF IDAHO AND MONTANA. ABUNDANT MID LEVEL
INSTABILITY AND MID LEVEL ALTO CU HAS TRACKED INTO WESTERN AND
CENTRAL NEBRASKA THIS MORNING...WITH RADAR INDICATING HIGHLY
ELEVATED SHOWERS...NONE OF WHICH IS REACHING THE GROUND ATTM. AT THE
SURFACE...A LEE SIDE TROUGH HAS BEGUN TO DEEPEN ACROSS THE PANHANDLE
AND FAR EASTERN COLORADO OVER THE PAST COUPLE OF HOURS. THIS HAS
RESULTED IN INCREASED SRLY WINDS THIS AFTERNOON AND INCREASED LOW
LEVEL MOISTURE...WITH DEW POINTS BEGINNING TO REACH INTO THE LOWER
40S AS OF 3 PM CDT. TEMPERATURES AS OF 3 PM CDT RANGED FROM 64
DEGREES AT VALENTINE TO 71 DEGREES AT OGALLALA.
&&
.UPDATE...
ISSUED AT 817 PM CDT FRI MAR 29 2013
THE SHOWERS AND THUNDERSTORMS HAVE LARGELY MOVED OFF TO THE EAST.
GIVEN THE RESIDUAL MOISTURE ALOFT WHICH WILL REMAIN IN PLACE THROUGH
SATURDAY EVENING. ISOLATED SHOWERS ARE POSSIBLE THROUGH MIDNIGHT
TONIGHT AND THEN AGAIN SATURDAY MORNING WITH SHOWERS AND
THUNDERSTORMS POSSIBLE SATURDAY AFTERNOON AS ANOTHER DISTURBANCE
MOVES THROUGH IN THE NORTHWEST FLOW ALOFT.
A NEW FORECAST IS OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 318 PM CDT FRI MAR 29 2013
MAIN FORECASTING CHALLENGES
OVER THE NEXT 24 HOURS ARE THUNDERSTORM POTENTIAL AND ASSOCIATED
PRECIPITATION CHANCES TONIGHT...THEN LOW PRECIPITATION CHANCES FOR
SATURDAY...IN PARTICULAR SATURDAY AFTERNOON. FOR TONIGHT...AM
EXPECTING SOME ISOLATED TSRA INITIATION INVOF OF SURFACE TROUGH AXIS
LATER THIS AFTERNOON. BASED ON THE LATEST NAM AND RUC SOLNS...THIS
SHOULD BE SOMEWHERE FROM AROUND OGALLALA TO NORTHERN CHERRY COUNTY
BY 21Z THIS AFTERNOON. AM EXPECTING ISOLATED CONVECTION TO FIRE
INVOF OF THIS FEATURE DURING THE 21Z TO 00Z TIME FRAME LATER THIS
AFTERNOON. DECENT MID LEVEL FLOW...WILL TRACK ANY ISOLATED
CONVECTION QUICKLY EAST INTO THE CENTRAL AND EASTERN CWFA LATER THIS
EVENING AND OVERNIGHT. CONVECTION IS EXPECTED TO BECOME BETTER
ORGANIZED IN THE EASTERN CWFA OVERNIGHT AS A NICE LOW LEVEL JET
PUSHES NORTH INTO EASTERN NEBR...THE NOSE OF WHICH PUSHES INTO OUR
NERN ZONES. FOR PRECIPITATION CHANCES TONIGHT...FAVORED POPS AROUND
20 PERCENT...ALONG AND WEST OF HIGHWAY 83...INCREASING THEM EASTWARD
TO AROUND 50 PERCENT IN THE NERN CWA. AS FOR THE THREAT OF SEVERE
THUNDERSTORMS TONIGHT...THE LATEST SWODY1 HAS A SEE TEXT ACROSS OUR
SWRN ZONES AND CENTRAL SANDHILLS MAINLY FOR EARLY EVENING CONVECTION
TIED TO PEAK HEATING. AT THIS JUNCTURE...SOME GUSTY WINDS MAY
ACCOMPANY THE STRONGEST STORMS GIVEN THE DRY CONDS BLO 10000 FT AGL
AND EXPECTED HIGH BASED TSRAS IN THE WEST. EVEN IN LIGHT OF WET BULB
ZEROES OF AROUND 9000 FT MSL...LARGE HAIL THREAT WILL BE MINIMAL AS
DEEP LAYER SHEAR IS ONLY AROUND 30 KTS AND FREEZING LEVELS ARE
AROUND 5 TO 7 THOUSAND FT AGL.
FOR SATURDAY...NORTHWESTERLY WINDS WILL DEVELOP BEHIND EXITING LOW
PRESSURE AND MAY BECOME GUSTY DURING THE AFTERNOON HOURS. WITH
SURFACE HEATING...MID LEVEL LAPSE RATES WILL STEEPEN SIGNIFICANTLY
DURING THE AFTERNOON HOURS...AND WILL CONTINUE MENTION OF ISOLATED
SHOWERS. LI`S ARE BARELY NEGATIVE TOMORROW AFTERNOON AND WILL FORGO
MENTION OF THUNDER ATTM. HIGHS SATURDAY WILL BE COOLER THAN TDYS
READINGS. BASED ON H85 TEMPS AND GOOD MIXING...HIGHS WILL RANGE FROM
THE 50S NORTH...TO THE LOWER 60S IN THE SOUTH.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 318 PM CDT FRI MAR 29 2013
SATURDAY NIGHT WILL SEE A DISTURBANCE PUSHING SOUTH AND AN ARCTIC
COLD FRONT DIPPING SOUTH ACROSS THE NORTHERN PLAINS. BY SUNDAY
AFTERNOON THE COLD FRONT WILL BE PUSHING INTO NRN NEBRASKA. SHOULD
SQUEAK OUT ANOTHER NICE DAY WITH HIGHS IN THE 60S FOR MOST OF THE
CWA. PORTIONS OF NORTH CENTRAL WILL SEE HIGHS ONLY IN THE 50S AS THE
COLD FRONT ARRIVES BEFORE PEAK HEAT. ALSO GOING TO SEE SOME SHOWERS
DEVELOP ALONG/AHEAD OF THE FRONT...MAINLY WHERE THERE IS BETTER
MOISTURE TO THE EAST. BY SUNDAY NIGHT COLD AIR WILL PUSH ACROSS THE
AREA. NOT A GREAT CHANCE FOR PRECIP...BUT COLD AIR ALOFT WILL CREATE
SOME STEEP LAPSE RATES. ALSO AS TEMPS FALL A MIX OR CHANGE TO SNOW
CAN BE EXPECTED.
MONDAY WILL FEEL THE COLD ARCTIC AIR AS HIGHS ONLY WARM INTO THE MID
30S TO MID 40S. PRECIP WILL BE PUSHING SOUTH...SO HIGHS MAY ACTUALLY
BE ABLE TO WARM UP A LITTLE MORE THAN FORECAST AS APRIL SUNSHINE
ARRIVES FOR THE AFTERNOON.
COLD AIR IS SHORT LIVED AS CENTER OF HIGH SHIFTS TO THE EAST FOR
TUESDAY...WITH RETURN SOUTHERLY FLOW BY TUESDAY AFTERNOON. NOT A
FAST REBOUND ON TUESDAY AS HIGHS ONLY IN THE 40S TO LOW 50S.
WEDNESDAY INTO THURSDAY WILL CONTINUE TO SEE A REBOUND OF TEMPS.
SURF HIGH CONTINUES TO PUSH TO THE SE WITH MORE WARM AIR TO PUSH
NORTHWARD AND THE BACKSIDE OF THE HIGH. 850 MB TEMPS PUSH INTO THE
SINGLE DIGITS ABOVE ZERO AND CLOSE TO 10 IN THE WEST WITH GUIDANCE
CLOSE TO 60. PRECIP CHANCES DO NOT LOOK GOOD THROUGH THE WEEK...AS
GULF MOISTURE REMAINS SHUT OFF AND MODELS CONTINUE A DRY BL. AN
UPPER LEVEL DISTURBANCE LATE IN THE WEEK MAY BRING SOME LIGHT
PRECIP...BUT WILL HAVE TO BE A TOP DOWN SATURATION AND DO NOT HAVE
IN THE FORECAST ATTM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 636 PM CDT FRI MAR 29 2013
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE EAST
THIS EVENING AND EXIT THE FCST AREA AROUND 06Z. VFR IS GENERALLY EXPECTED
THEREAFTER THROUGH SATURDAY AFTERNOON. ISOLATED AFTERNOON SHOWERS
ARE EXPECTED TO DEVELOP WHICH COULD PRODUCE LOCAL MVFR.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
637 PM CDT FRI MAR 29 2013
.SYNOPSIS...
ISSUED AT 318 PM CDT FRI MAR 29 2013
H5 HAND ANALYSIS THIS MORNING IS INDICATING BROAD LOW
AMPLITUDE FLOW ACROSS THE LOWER 48...WITH EMBEDDED SHORTWAVES NOTED
OVER THE NORTHERN ROCKIES OF IDAHO AND MONTANA. ABUNDANT MID LEVEL
INSTABILITY AND MID LEVEL ALTO CU HAS TRACKED INTO WESTERN AND
CENTRAL NEBRASKA THIS MORNING...WITH RADAR INDICATING HIGHLY
ELEVATED SHOWERS...NONE OF WHICH IS REACHING THE GROUND ATTM. AT THE
SURFACE...A LEE SIDE TROUGH HAS BEGUN TO DEEPEN ACROSS THE PANHANDLE
AND FAR EASTERN COLORADO OVER THE PAST COUPLE OF HOURS. THIS HAS
RESULTED IN INCREASED SRLY WINDS THIS AFTERNOON AND INCREASED LOW
LEVEL MOISTURE...WITH DEW POINTS BEGINNING TO REACH INTO THE LOWER
40S AS OF 3 PM CDT. TEMPERATURES AS OF 3 PM CDT RANGED FROM 64
DEGREES AT VALENTINE TO 71 DEGREES AT OGALLALA.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 318 PM CDT FRI MAR 29 2013
MAIN FORECASTING CHALLENGES
OVER THE NEXT 24 HOURS ARE THUNDERSTORM POTENTIAL AND ASSOCIATED
PRECIPITATION CHANCES TONIGHT...THEN LOW PRECIPITATION CHANCES FOR
SATURDAY...IN PARTICULAR SATURDAY AFTERNOON. FOR TONIGHT...AM
EXPECTING SOME ISOLATED TSRA INITIATION INVOF OF SURFACE TROUGH AXIS
LATER THIS AFTERNOON. BASED ON THE LATEST NAM AND RUC SOLNS...THIS
SHOULD BE SOMEWHERE FROM AROUND OGALLALA TO NORTHERN CHERRY COUNTY
BY 21Z THIS AFTERNOON. AM EXPECTING ISOLATED CONVECTION TO FIRE
INVOF OF THIS FEATURE DURING THE 21Z TO 00Z TIME FRAME LATER THIS
AFTERNOON. DECENT MID LEVEL FLOW...WILL TRACK ANY ISOLATED
CONVECTION QUICKLY EAST INTO THE CENTRAL AND EASTERN CWFA LATER THIS
EVENING AND OVERNIGHT. CONVECTION IS EXPECTED TO BECOME BETTER
ORGANIZED IN THE EASTERN CWFA OVERNIGHT AS A NICE LOW LEVEL JET
PUSHES NORTH INTO EASTERN NEBR...THE NOSE OF WHICH PUSHES INTO OUR
NERN ZONES. FOR PRECIPITATION CHANCES TONIGHT...FAVORED POPS AROUND
20 PERCENT...ALONG AND WEST OF HIGHWAY 83...INCREASING THEM EASTWARD
TO AROUND 50 PERCENT IN THE NERN CWA. AS FOR THE THREAT OF SEVERE
THUNDERSTORMS TONIGHT...THE LATEST SWODY1 HAS A SEE TEXT ACROSS OUR
SWRN ZONES AND CENTRAL SANDHILLS MAINLY FOR EARLY EVENING CONVECTION
TIED TO PEAK HEATING. AT THIS JUNCTURE...SOME GUSTY WINDS MAY
ACCOMPANY THE STRONGEST STORMS GIVEN THE DRY CONDS BLO 10000 FT AGL
AND EXPECTED HIGH BASED TSRAS IN THE WEST. EVEN IN LIGHT OF WET BULB
ZEROES OF AROUND 9000 FT MSL...LARGE HAIL THREAT WILL BE MINIMAL AS
DEEP LAYER SHEAR IS ONLY AROUND 30 KTS AND FREEZING LEVELS ARE
AROUND 5 TO 7 THOUSAND FT AGL.
FOR SATURDAY...NORTHWESTERLY WINDS WILL DEVELOP BEHIND EXITING LOW
PRESSURE AND MAY BECOME GUSTY DURING THE AFTERNOON HOURS. WITH
SURFACE HEATING...MID LEVEL LAPSE RATES WILL STEEPEN SIGNIFICANTLY
DURING THE AFTERNOON HOURS...AND WILL CONTINUE MENTION OF ISOLATED
SHOWERS. LI`S ARE BARELY NEGATIVE TOMORROW AFTERNOON AND WILL FORGO
MENTION OF THUNDER ATTM. HIGHS SATURDAY WILL BE COOLER THAN TDYS
READINGS. BASED ON H85 TEMPS AND GOOD MIXING...HIGHS WILL RANGE FROM
THE 50S NORTH...TO THE LOWER 60S IN THE SOUTH.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 318 PM CDT FRI MAR 29 2013
SATURDAY NIGHT WILL SEE A DISTURBANCE PUSHING SOUTH AND AN ARCTIC
COLD FRONT DIPPING SOUTH ACROSS THE NORTHERN PLAINS. BY SUNDAY
AFTERNOON THE COLD FRONT WILL BE PUSHING INTO NRN NEBRASKA. SHOULD
SQUEAK OUT ANOTHER NICE DAY WITH HIGHS IN THE 60S FOR MOST OF THE
CWA. PORTIONS OF NORTH CENTRAL WILL SEE HIGHS ONLY IN THE 50S AS THE
COLD FRONT ARRIVES BEFORE PEAK HEAT. ALSO GOING TO SEE SOME SHOWERS
DEVELOP ALONG/AHEAD OF THE FRONT...MAINLY WHERE THERE IS BETTER
MOISTURE TO THE EAST. BY SUNDAY NIGHT COLD AIR WILL PUSH ACROSS THE
AREA. NOT A GREAT CHANCE FOR PRECIP...BUT COLD AIR ALOFT WILL CREATE
SOME STEEP LAPSE RATES. ALSO AS TEMPS FALL A MIX OR CHANGE TO SNOW
CAN BE EXPECTED.
MONDAY WILL FEEL THE COLD ARCTIC AIR AS HIGHS ONLY WARM INTO THE MID
30S TO MID 40S. PRECIP WILL BE PUSHING SOUTH...SO HIGHS MAY ACTUALLY
BE ABLE TO WARM UP A LITTLE MORE THAN FORECAST AS APRIL SUNSHINE
ARRIVES FOR THE AFTERNOON.
COLD AIR IS SHORT LIVED AS CENTER OF HIGH SHIFTS TO THE EAST FOR
TUESDAY...WITH RETURN SOUTHERLY FLOW BY TUESDAY AFTERNOON. NOT A
FAST REBOUND ON TUESDAY AS HIGHS ONLY IN THE 40S TO LOW 50S.
WEDNESDAY INTO THURSDAY WILL CONTINUE TO SEE A REBOUND OF TEMPS.
SURF HIGH CONTINUES TO PUSH TO THE SE WITH MORE WARM AIR TO PUSH
NORTHWARD AND THE BACKSIDE OF THE HIGH. 850 MB TEMPS PUSH INTO THE
SINGLE DIGITS ABOVE ZERO AND CLOSE TO 10 IN THE WEST WITH GUIDANCE
CLOSE TO 60. PRECIP CHANCES DO NOT LOOK GOOD THROUGH THE WEEK...AS
GULF MOISTURE REMAINS SHUT OFF AND MODELS CONTINUE A DRY BL. AN
UPPER LEVEL DISTURBANCE LATE IN THE WEEK MAY BRING SOME LIGHT
PRECIP...BUT WILL HAVE TO BE A TOP DOWN SATURATION AND DO NOT HAVE
IN THE FORECAST ATTM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 636 PM CDT FRI MAR 29 2013
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE EAST
THIS EVENING AND EXIT THE FCST AREA AROUND 06Z. VFR IS GENERALLY EXPECTED
THEREAFTER THROUGH SATURDAY AFTERNOON. ISOLATED AFTERNOON SHOWERS
ARE EXPECTED TO DEVELOP WHICH COULD PRODUCE LOCAL MVFR.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...MASEK
AVIATION...CDC
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
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
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 NEWPORT/MOREHEAD CITY NC
1038 PM EDT FRI MAR 29 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE OFFSHORE JUST SOUTH OF THE AREA TONIGHT.
A WEAK BACKDOOR COLD FRONT WILL PUSH DOWN THE NORTH CAROLINA COAST
BEFORE STALLING NEAR CAPE HATTERAS ON SATURDAY. THE FRONT WILL
RETURN BACK NORTH AS A WARM FRONT ON SUNDAY. A SLOW MOVING COLD
FRONT WILL APPROACH THE AREA MONDAY AND CROSS THE AREA MONDAY
NIGHT. A COOL HIGH PRESSURE BUILDS INTO THE REGION DURING THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1035 PM FRIDAY...EARLY PANELS OF THE 00Z MODEL CYCLE STILL
SHOWING A WELL- DEFINED MID- LEVEL SHORTWAVE TO DIVE SOUTHEAST
ACROSS NORTH CAROLINA TOWARD MORNING. RAP...NAM AND 4 KM WRF
SIMULATED RADAR REFLECTIVITY ALL SHOW SOME LIGHT PRECIP ACROSS THE
FAR SOUTHWESTERN CWA EARLY TOMORROW MORNING. ONLY REAL CHANGE TO
FORECAST IS TO LOWER MIN TEMPS A COUPLE OF DEGREES BASED ON
CURRENT READINGS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
SLIGHT TO LOW PRECIP CHANCES CONTINUE INTO SAT MORNING FOR FAR
SOUTHERN AREAS ONLY. ANY LIGHT PRECIP...MAINLY IN THE FORM OF
SPRINKLES WILL BE WANING AS THE SHORT WAVE PASSES OFF THE COAST
NEAR MIDDAY. AT THE SFC A WIND SHIFT BNDRY WILL CREEP DOWN THE
COAST BEFORE STALLING IN THE VICINITY OF HATTERAS SAT AFTN.
HAVE FAVORED THE COOLER MOS GUIDANCE FOR MAX TEMPS TOMORROW GIVEN
THE EXPECTED EXTENSIVE CLOUD COVER AND WIND SHIFT OVER THE OUTER
BANKS. HIGHS INLAND MAY REACH INTO THE LOWER 60S ESPECIALLY IF
ANY APPRECIABLE SUNSHINE CAN DEVELOP DURING THE AFTN. REMAINING
IN THE COOL LOWER TO MID 50S FOR OBX.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM FRI...A WARM FRONT WILL PUSH NORTH THROUGH EASTERN
NC SAT NIGHT WITH DEWPOINTS RISING INTO THE 40S. CLOUD COVER AND
INCREASED SOUTHERLY WAA FLOW WILL KEEP TEMPS IN THE LOW/MID 40S
INLAND TO UPPER 40S OBX. PRECIP CHANCES INCREASE LATE SAT NIGHT AS
A SHORTWAVE AHEAD OF THE MAIN UPPER AND SURFACE TROUGH APPROACHES
FROM THE WEST. POPS WILL INCREASE TO HIGH CHANCE SUN AS A COLD
FRONT WILL CROSS THE REGION. TEMPS WILL BE CLOSE TO CLIMO...MID TO
UPPER 60S INLAND TO AROUND 60 OBX. 12Z GUIDANCE INDICATES WEAK
INSTABILITY SUN AFTERNOON ALTHOUGH THE SCENARIO APPEARS MORE STABLE
WITH PRECIP AND CLOUD COVER INHIBITING MUCH INSOLATION.
MODELS IN GOOD AGREEMENT WITH PRECIP OFF THE COAST SUN NIGHT INTO
EARLY MON THOUGH COULD SEE AN ISOLATED SHOWER...ESPECIALLY
THROUGH PEAK HEATING MON AFTERNOON ACROSS SOUTHERN ZONES. TEMPS MON
WILL FINALLY BUILD TO AROUND 70. A SECONDARY COLD FRONT WILL PUSH
THROUGH EASTERN NC EARLY TUES MORNING. 12Z GFS IS NOW ABOUT 6
HOURS SLOWER THAN THE 12Z ECMWF BUT WILL CONTINUE TO FOLLOW CLOSER
TO THE ECMWF FOR THE EXTENDED. WILL MAINTAIN CHANCE POPS TUES AS
MODELS IN FAIR AGREEMENT BRINGING OVERRUNNING MOISTURE OVER A
STRONG LOW LEVEL INVERSION. A NON-DIURNAL TEMP CURVE IS LIKELY
MON NIGHT INTO TUE WITH LOWS MAINLY IN THE LOW TO MID 50S AHEAD OF
THE FRONT MON NIGHT...THEN HIGHS LIKELY IN THE MID TO UPPER 50S
EARLY TUE WITH CAA AND LOW CLOUDS/PRECIP RAMPING UP AFTER FRONTAL
PASSAGE. NORTHERLY FLOW WED BRINGS CAA WITH HIGH PRESSURE BUILDING
IN FROM THE WEST AND EXPECT DRY BUT COOLER CONDITIONS WITH HIGHS
IN THE 50S. TUES NIGHT AND WED NIGHT BRING THE NEXT CHANCE FOR
FROST/FREEZE POTENTIAL WITH LOWS IN THE MID TO UPPER 30S. THE MORE
PESSIMISTIC ECMWF MOS DROPS TEMPS DOWN INTO THE UPPER 20S TO LOWER
30S. WILL HOLD WITH LOWS IN THE MID TO UPPER 30S BOTH NIGHTS.
HIGH PRESSURE SLIDES OFF THE COAST THURS IN ADVANCE OF A ROBUST
MID LEVEL SHORTWAVE MOVING ACROSS THE CENTRAL PLAINS. CLOUDS
EXPECTED TO INCREASE THROUGH THE DAY THURS AS THE SYSTEM TAPS INTO
RICH GULF MOISTURE BUT MODELS IN AGREEMENT HOLDING OFF PCPN UNTIL
LATE THU NIGHT AT THE EARLIEST. THE 12Z ECMWF/GFS BLEND IS IN
DECENT AGREEMENT FOR DAY 7 WITH THE LOCATION OF THE SURFACE LOW
AND UPPER FEATURES. HAVE ADDED SLIGHT CHANCE POPS THURS NIGHT AND
FRI. TEMPS THURS AND FRI WILL REMAIN BELOW CLIMO WITH HIGHS IN
THE MID 50S THURS TO LOW 60S FRI.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /TONIGHT AND SATURDAY/...
AS OF 710 PM FRIDAY...GENERALLY SOME SCATTERED TO BROKEN MID AND
HIGH LEVEL CLOUDS ACROSS THE NORTHERN SECTIONS OF THE CWA WITH
GENERALLY CLEAR SKIES TO THE SOUTH. LATEST SATELLITE DOES SHOW
SOME INCREASE IN CLOUDS APPROACHING THE SOUTHERN COUNTIES OVER THE
NEXT FEW HOURS. A WELL-DEFINED SHORTWAVE CROSSING THE AREA LATER
TONIGHT INTO SATURDAY MORNING WILL BE MOISTURE DEPRIVED IN THE LOWER
LAYERS. DESPITE A SIGNIFICANT INCREASE IN CLOUDS...EXPECT CLOUD
BASES TO REMAIN AOA 4-5K FT. MAY ALSO SEE SOME LIGHT RAIN/SPRINKLES
VERY LATE TONIGHT THRU SAT MORNING...MAINLY OVER THE SOUTHERNMOST
TERMINALS.
LONG TERM /SAT NIGHT THRU WEDNESDAY/...
AS OF 410 PM FRI...VFR CONDITIONS EXPECTED TO PREVAIL THROUGH SAT
NIGHT AS HIGH PRESSURE SLIDES OFF THE COAST. SUB-VFR CONDITIONS
POSSIBLE SUN INTO SUN NIGHT AS PRECIP ASSOCIATED WITH A COLD FRONT
CROSSES THE TERMINALS. SOUTHERLY WINDS SAT AND SOUTHWESTERLY WINDS
SUN MAY BE GUSTY AS THE GRADIENT TIGHTENS AHEAD OF THE COLD FRONT
WHICH WILL CROSS THE REGION SUN NIGHT. A SECOND COLD FRONT WILL
MOVE ACROSS ROUTES EARLY TUES WITH A STRONG LOW LEVEL INVERSION
DEVELOPING AFTER FROPA WITH SUB-VFR CONDITIONS POSSIBLE. HIGH
PRESSURE BUILDS OVER THE REGION WED WITH A RETURN TO VFR.
&&
.MARINE...
SHORT TERM /TONIGHT AND SATURDAY/...
AS OF 1035 PM FRIDAY...WINDS ARE SLOWLY VEERING TO S/SSW ACROSS
THE COASTAL WATERS WHILE REMAINING SSE/S OVER THE SOUNDS. SPEEDS
SHOULD REMAIN BELOW 15 KNOTS AND VEER MORE TOWARD THE WEST BY MORNING
PER LATEST RAP AND NAM12 MODELS. NO MAJOR CHANGES NEEDED TO MARINE
FORECAST AT THIS TIME. WINDS SHIFT N/NE OVER NORTHERN AREAS BEHIND
THE BACKDOOR FRONT SAT AFTN BUT REMAIN LIGHT GIVEN THE WEAK
GRADIENT. SEAS MAINLY 1-3 FT THRU THE PERIOD EXCEPT POSSIBLE 4
FOOTERS FAR OUTER WTRS.
LONG TERM /SAT NIGHT THRU WEDNESDAY/...
AS OF 415 PM FRI...WINDS BLO 15 KT WILL SHIFT TO S/SE SAT NIGHT
AS A SFC RIDGE SHIFTS OFF THE COAST WHILE SEAS WILL BE AROUND 1-3
FT. WINDS SHIFT TO S/SW AND INCREASE TO 15-25 KT SUN AFTERNOON
WITH SEAS BUILDING TO 4-7 FT ACROSS THE SOUTHERN WATERS AND 3-5 FT
NORTHERN WATERS LATE SUN THROUGH SUN NIGHT. WINDS WILL DIMINISH TO
10-15 KT MON WITH 3-5 FT SEAS SUBSIDING TO 2-4 FT. A COLD FRONT
WILL PUSH THROUGH THE WATERS EARLY TUESDAY WITH MODERATE CAA IN N
FLOW AROUND 15-20 KTS WITH SEAS BUILDING TO 4-7 FT. HIGH PRESSURE
WILL BUILD OVER THE WATERS WED WITH NORTHERLY WINDS DIMINISHING
10-15 KT AND SEAS SUBSIDING TO 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC
SHORT TERM...BTC
LONG TERM...DAG
AVIATION...CTC/BTC/DAG
MARINE...CTC/BTC/DAG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
715 PM EDT FRI MAR 29 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE OFFSHORE JUST SOUTH OF THE AREA TONIGHT.
A WEAK BACKDOOR COLD FRONT WILL PUSH DOWN THE NORTH CAROLINA COAST
BEFORE STALLING NEAR CAPE HATTERAS ON SATURDAY. THE FRONT WILL
RETURN BACK NORTH AS A WARM FRONT ON SUNDAY. A SLOW MOVING COLD
FRONT WILL APPROACH THE AREA MONDAY AND CROSS THE AREA MONDAY
NIGHT. A COOL HIGH PRESSURE BUILDS INTO THE REGION DURING THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 705 PM FRIDAY...GOOD AGREEMENT AMONGST THE RAP...NAM12 AND
GFS SHOWING A WELL-DEFINED SHORTWAVE EMBEDDED IN THE NORTHWESTERLY
FLOW AT THE MID-LEVELS MOVING SOUTHEAST ACROSS THE REGION LATER
TONIGHT AND EARLY SATURDAY. ALL OF THE SHORT TERM MODELS PRODUCE
SOME LIGHT QPF OVER THE SOUTHERN COUNTIES TOWARD MORNING AND HAVE
CONTINUED THIS TREND. QPF WILL BE LIGHT...JUST A FEW HUNDREDTHS OF
AN INCH AT BEST AND WILL LIKELY ONLY AFFECT DUPLIN AND ONSLOW
COUNTIES AND PERHAPS PORTIONS OF SOUTHERN JONES...CARTERET AND
CRAVEN COUNTIES THROUGH THE EARLY MORNING HOURS. WITH THE
INCREASING CLOUD COVER ASSOCIATED WITH THE SHORTWAVE...AND WITH
CURRENT TEMPERATURES STILL IN THE 50S...NO ISSUE FOR FROST/FREEZE
OVERNIGHT WITH THE COOLEST LOWS LIKELY IN THE UPPER 30S TO LOWER
40S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
SLIGHT TO LOW PRECIP CHANCES CONTINUE INTO SAT MORNING FOR FAR
SOUTHERN AREAS ONLY. ANY LIGHT PRECIP...MAINLY IN THE FORM OF
SPRINKLES WILL BE WANING AS THE SHORT WAVE PASSES OFF THE COAST
NEAR MIDDAY. AT THE SFC A WIND SHIFT BNDRY WILL CREEP DOWN THE
COAST BEFORE STALLING IN THE VICINITY OF HATTERAS SAT AFTN.
HAVE FAVORED THE COOLER MOS GUIDANCE FOR MAX TEMPS TOMORROW GIVEN
THE EXPECTED EXTENSIVE CLOUD COVER AND WIND SHIFT OVER THE OUTER
BANKS. HIGHS INLAND MAY REACH INTO THE LOWER 60S ESPECIALLY IF
ANY APPRECIABLE SUNSHINE CAN DEVELOP DURING THE AFTN. REMAINING
IN THE COOL LOWER TO MID 50S FOR OBX.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM FRI...A WARM FRONT WILL PUSH NORTH THROUGH EASTERN
NC SAT NIGHT WITH DEWPOINTS RISING INTO THE 40S. CLOUD COVER AND
INCREASED SOUTHERLY WAA FLOW WILL KEEP TEMPS IN THE LOW/MID 40S
INLAND TO UPPER 40S OBX. PRECIP CHANCES INCREASE LATE SAT NIGHT AS
A SHORTWAVE AHEAD OF THE MAIN UPPER AND SURFACE TROUGH APPROACHES
FROM THE WEST. POPS WILL INCREASE TO HIGH CHANCE SUN AS A COLD
FRONT WILL CROSS THE REGION. TEMPS WILL BE CLOSE TO CLIMO...MID TO
UPPER 60S INLAND TO AROUND 60 OBX. 12Z GUIDANCE INDICATES WEAK
INSTABILITY SUN AFTERNOON ALTHOUGH THE SCENARIO APPEARS MORE STABLE
WITH PRECIP AND CLOUD COVER INHIBITING MUCH INSOLATION.
MODELS IN GOOD AGREEMENT WITH PRECIP OFF THE COAST SUN NIGHT INTO
EARLY MON THOUGH COULD SEE AN ISOLATED SHOWER...ESPECIALLY
THROUGH PEAK HEATING MON AFTERNOON ACROSS SOUTHERN ZONES. TEMPS MON
WILL FINALLY BUILD TO AROUND 70. A SECONDARY COLD FRONT WILL PUSH
THROUGH EASTERN NC EARLY TUES MORNING. 12Z GFS IS NOW ABOUT 6
HOURS SLOWER THAN THE 12Z ECMWF BUT WILL CONTINUE TO FOLLOW CLOSER
TO THE ECMWF FOR THE EXTENDED. WILL MAINTAIN CHANCE POPS TUES AS
MODELS IN FAIR AGREEMENT BRINGING OVERRUNNING MOISTURE OVER A
STRONG LOW LEVEL INVERSION. A NON-DIURNAL TEMP CURVE IS LIKELY
MON NIGHT INTO TUE WITH LOWS MAINLY IN THE LOW TO MID 50S AHEAD OF
THE FRONT MON NIGHT...THEN HIGHS LIKELY IN THE MID TO UPPER 50S
EARLY TUE WITH CAA AND LOW CLOUDS/PRECIP RAMPING UP AFTER FRONTAL
PASSAGE. NORTHERLY FLOW WED BRINGS CAA WITH HIGH PRESSURE BUILDING
IN FROM THE WEST AND EXPECT DRY BUT COOLER CONDITIONS WITH HIGHS
IN THE 50S. TUES NIGHT AND WED NIGHT BRING THE NEXT CHANCE FOR
FROST/FREEZE POTENTIAL WITH LOWS IN THE MID TO UPPER 30S. THE MORE
PESSIMISTIC ECMWF MOS DROPS TEMPS DOWN INTO THE UPPER 20S TO LOWER
30S. WILL HOLD WITH LOWS IN THE MID TO UPPER 30S BOTH NIGHTS.
HIGH PRESSURE SLIDES OFF THE COAST THURS IN ADVANCE OF A ROBUST
MID LEVEL SHORTWAVE MOVING ACROSS THE CENTRAL PLAINS. CLOUDS
EXPECTED TO INCREASE THROUGH THE DAY THURS AS THE SYSTEM TAPS INTO
RICH GULF MOISTURE BUT MODELS IN AGREEMENT HOLDING OFF PCPN UNTIL
LATE THU NIGHT AT THE EARLIEST. THE 12Z ECMWF/GFS BLEND IS IN
DECENT AGREEMENT FOR DAY 7 WITH THE LOCATION OF THE SURFACE LOW
AND UPPER FEATURES. HAVE ADDED SLIGHT CHANCE POPS THURS NIGHT AND
FRI. TEMPS THURS AND FRI WILL REMAIN BELOW CLIMO WITH HIGHS IN
THE MID 50S THURS TO LOW 60S FRI.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM /TONIGHT AND SATURDAY/...
AS OF 710 PM FRIDAY...GENERALLY SOME SCATTERED TO BROKEN MID AND
HIGH LEVEL CLOUDS ACROSS THE NORTHERN SECTIONS OF THE CWA WITH
GENERALLY CLEAR SKIES TO THE SOUTH. LATEST SATELLITE DOES SHOW
SOME INCREASE IN CLOUDS APPROACHING THE SOUTHERN COUNTIES OVER THE
NEXT FEW HOURS. A WELL-DEFINED SHORTWAVE CROSSING THE AREA LATER
TONIGHT INTO SATURDAY MORNING WILL BE MOISTURE DEPRIVED IN THE LOWER
LAYERS. DESPITE A SIGNIFICANT INCREASE IN CLOUDS...EXPECT CLOUD
BASES TO REMAIN AOA 4-5K FT. MAY ALSO SEE SOME LIGHT RAIN/SPRINKLES
VERY LATE TONIGHT THRU SAT MORNING...MAINLY OVER THE SOUTHERNMOST
TERMINALS.
LONG TERM /SAT NIGHT THRU WEDNESDAY/...
AS OF 410 PM FRI...VFR CONDITIONS EXPECTED TO PREVAIL THROUGH SAT
NIGHT AS HIGH PRESSURE SLIDES OFF THE COAST. SUB-VFR CONDITIONS
POSSIBLE SUN INTO SUN NIGHT AS PRECIP ASSOCIATED WITH A COLD FRONT
CROSSES THE TERMINALS. SOUTHERLY WINDS SAT AND SOUTHWESTERLY WINDS
SUN MAY BE GUSTY AS THE GRADIENT TIGHTENS AHEAD OF THE COLD FRONT
WHICH WILL CROSS THE REGION SUN NIGHT. A SECOND COLD FRONT WILL
MOVE ACROSS ROUTES EARLY TUES WITH A STRONG LOW LEVEL INVERSION
DEVELOPING AFTER FROPA WITH SUB-VFR CONDITIONS POSSIBLE. HIGH
PRESSURE BUILDS OVER THE REGION WED WITH A RETURN TO VFR.
&&
.MARINE...
SHORT TERM /TONIGHT AND SATURDAY/...
AS OF 710 PM FRIDAY...CURRENT WINDS ARE ESE/SE OVER THE WATERS
NORTH OF CAPE LOOKOUT WITH S/SW TO THE SOUTH. SPEEDS SHOULD REMAIN
BELOW 15 KNOTS AND WILL VEER TO A MORE WESTERLY DIRECTION TOWARD
MORNING PER LATEST RAP AND NAM12 MODELS. NO MAJOR CHANGES NEEDED
TO MARINE FORECAST AT THIS TIME. WINDS SHIFT N/NE OVER NORTHERN
AREAS BEHIND THE BACKDOOR FRONT SAT AFTN BUT REMAIN LIGHT GIVEN
THE WEAK GRADIENT. SEAS MAINLY 1-3 FT THRU THE PERIOD EXCEPT
POSSIBLE 4 FOOTERS FAR OUTER WTRS.
LONG TERM /SAT NIGHT THRU WEDNESDAY/...
AS OF 415 PM FRI...WINDS BLO 15 KT WILL SHIFT TO S/SE SAT NIGHT
AS A SFC RIDGE SHIFTS OFF THE COAST WHILE SEAS WILL BE AROUND 1-3
FT. WINDS SHIFT TO S/SW AND INCREASE TO 15-25 KT SUN AFTERNOON
WITH SEAS BUILDING TO 4-7 FT ACROSS THE SOUTHERN WATERS AND 3-5 FT
NORTHERN WATERS LATE SUN THROUGH SUN NIGHT. WINDS WILL DIMINISH TO
10-15 KT MON WITH 3-5 FT SEAS SUBSIDING TO 2-4 FT. A COLD FRONT
WILL PUSH THROUGH THE WATERS EARLY TUESDAY WITH MODERATE CAA IN N
FLOW AROUND 15-20 KTS WITH SEAS BUILDING TO 4-7 FT. HIGH PRESSURE
WILL BUILD OVER THE WATERS WED WITH NORTHERLY WINDS DIMINISHING
10-15 KT AND SEAS SUBSIDING TO 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC
SHORT TERM...BTC
LONG TERM...DAG
AVIATION...CTC/BTC/DAG
MARINE...CTC/BTC/DAG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
911 PM CDT FRI MAR 29 2013
.DISCUSSION...
MAIN HEADACHES FOR THIS EVENING HAVE BEEN FOG AND RAIN/FREEZING
RAIN. AREAS OF DENSE FOG HAVE CONTINUED OVER PORTIONS OF THE
NORTHERN RED RIVER VALLEY SINCE JUST BEFORE SUNSET. HOWEVER...WEB
CAMS SHOW THERE IS SOME VARIATION IN THE DENSITY AND WITH SHOWERS
MOVING INTO THE REGION FROM THE WEST...THINK THERE SHOULD BE SOME
IMPROVEMENT DURING THE NEXT FEW HOURS. LANGDON HAS ALREADY
IMPROVED FROM A QUARTER OF A MILE UP TO THREE MILES AND THINK THIS
SHOULD CONTINUE AS THE RADAR RETURNS MOVE EAST. WILL COVER THE FOG
WITH NOWCASTS AND A MENTION IN THE GRIDS...BUT HOLD OFF ON ANY
ADVISORY FOR NOW.
THE NEXT QUESTION WILL BE HOW MUCH RAIN OR FREEZING RAIN FALLS
OVERNIGHT. RUC AND NAM ARE IN PRETTY GOOD AGREEMENT ON PRECIP
INTENSIFYING OVER OUR SOUTHEASTERN COUNTIES AS THE MAIN SHORTWAVE
DIGS INTO THE AREA. FORTUNATELY...TEMPS IN OUR SOUTH AND SOUTHEAST
HAVE BEEN HOLDING ABOVE FREEZING FOR NOW AND THINK THAT AT LEAST
OUR FAR SOUTHEASTERN COUNTIES WILL NOT GET DOWN BELOW 32 UNTIL THE
VERY EARLY MORNING HOURS. WILL KEEP PRECIP ALL LIQUID RAIN IN THE
SOUTHEAST. DECENT RADAR RETURNS HAVE BEEN DEVELOPING OVER GRIGGS
STEELE AND TRAILL COUNTIES...AND TEMPS HAVE BEEN HOLDING RIGHT
AROUND 32 DEGREES. SO FAR NOT MUCH MORE THAN A HUNDREDTH OR TWO
HAS FALLEN AND NO WIDESPREAD SLICK ROADS REPORTED. HOWEVER...WILL
HAVE TO KEEP AN EYE ON THINGS AS TEMPS CONTINUE TO DROP OVERNIGHT.
FURTHER NORTH OVER THE DEVILS LAKE BASIN INTO THE NORTHERN RED
RIVER VALLEY...DO NOT THINK MUCH WILL REACH THE GROUND BUT
INCLUDED A SMALL MENTION. FOR NOW HEAVIEST AMOUNTS SEEM THAT THEY
WILL BE LIQUID RAIN SO WILL KEEP ANY FREEZING RAIN ADVISORY OUT
FOR NOW.
&&
.AVIATION...
VLIFR CONTINUES AT KGFK AND MVFR CONDITIONS AT KDVL AND KFAR.
THINK THAT THERE WILL BE SOME IMPROVEMENT AT KGFK AS FZRA SHOWERS
MOVE INTO THE AREA. MVFR TO IFR CONDITIONS WILL CONTINUE FOR MUCH
OF THE NIGHT HOWEVER...WITH SOME FZRA AND RA POSSIBLE. EVEN KTVF
AND KBJI WHICH ARE VFR AND WILL REMAIN MOSTLY DRY SHOULD SEE SOME
DETERIORATION DOWN TO MVFR. VFR CONDITIONS WILL RETURN AFTER 18Z
SATURDAY AS WINDS PICK UP OUT OF THE NORTHWEST.
&&
.PREV DISCUSSION... /ISSUED 324 PM CDT FRI MAR 29 2013/
SHORT TERM...
MAIN CHALLENGE FOR THIS FORECAST CONTINUES TO BE PERSISTENT FOG
AND TEMPERATURES. SOUNDINGS CONTINUE TO SHOW STRONG INVERSION NEAR
THE SURFACE WITH LIGHT WINDS...THUS EXPECT AREAS OF FOG TO
CONTINUE IN THE DVL BASIN AND ALONG THE RED RIVER VALLEY.
HOWEVER...WILL LET THE ADVISORY EXPIRE AT 21Z AS MOST AREAS HAVE
IMPROVED.
FOR THIS EVENING INTO TONIGHT...A WAVE ASSOCIATED WITH AN AREA OF
LOW PRESSURE IS EXPECTED TO MOVE ACROSS THE AREA TONIGHT. ANALYSIS
OF THE 295K ISENTROPIC SFC SHOWS DECENT UPGLIDE AND FAVORABLE
CONDENSATION PRESSURE DEFICITS POINTING TOWARD PCPN OVERNIGHT.
FCST SOUNDINGS SHOW A WARM LAYER ALOFT AND IS SUFFICIENTLY DEEP TO
FAVOR -ZR ACROSS THE SRN ZONES AND IS REFLECTED IN THE GRIDS.
FOR SATURDAY...GFS AND ECMWF SHOW GOOD COLD ADVECTION BEHIND THE
FRONT WITH BREEZY CONDITIONS AND EXPECT THE COLD AIR WILL OFFSET
ANY SOLAR. WITH A SIGNIFICANT SNOWPACK OVER THE FA...WILL KEEP
TEMPS A BIT COOLER WITH LITTLE RECOVERY DURING THE DAY.
OTHERWISE...EXPECT LOWS SUNDAY MORNING TO BE NEAR SINGLE DIGITS
ACROSS THE NORTH. THE SFC RIDGE LOOKS TO CROSS THE AREA RAPIDLY
AND RETURN FLOW ON MONDAY WILL HELP TEMPS RECOVER A BIT BUT REMAIN
BELOW SEASONAL AVERAGES. LITTLE PCPN IS EXPECTED FOR THE REMAINDER
OF THE WEEKEND.
LONG TERM (TUE THRU FRI)...
THROUGH MUCH OF THE EXTENDED PERIOD THE VARIOUS MODELS ARE IN
DECENT AGREEMENT THROUGH MOST OF THIS PERIOD. LIKE THE GFS BLENDED
WITH BC-ECMWF. MODELS DIVERGE ON SOLUTIONS TOWARD THE END OF THE
PERIOD AND BEYOND.
AT THE START OF THE EXTENDED A SHARP TROUGH OVER THE GREAT LAKES
WITH RESULTING NORTHWEST FLOW OVER CWFA. ECMWF/GEM/GFS/DGEX ALL IN
GOOD AGREEMENT WITH SURFACE HIGH NORTH TO SOUTH THROUGH FA. LIGHT
WINDS AND DECREASING CLOUD COVER FORECAST SO HAVE OPTED TO LOWER
MINS TUESDAY MORNING ABOUT 5F...CLOSER TO BC-GRIDS WHICH HAVE BEEN
PERFORMING BETTER.
RETURN FLOW BEGINS BY 00Z WEDNESDAY BUT GUIDANCE SUGGESTS LOW LEVEL
WAA SLOW TO CRANK UP. THEREFORE HAVE LOWERED MAXES ABOUT 2F TO 4F...
AGAIN LEANING ON A BC-BLEND. LOW LEVEL WAA DOES KICK IN PRETTY
STRONGLY BY 12Z WEDNESDAY. WHEN COMBINED WITH APPROACHING SHORTWAVE
..LOW LEVEL LIFT...850-500MB OMEGA AND LOWER COND PRES DEF LIKE
THE IDEA OF SLGHT CHC/CHC POPS. LIKELY A MIX OF RA/SN...PERHAPS ALL
RA AFTERNOON...BUT LIGHT AMOUNTS FORECAST.
MODEST BOUNDARY LAYER TEMPERATURE DROP OF 4C TO 6C FORECAST BETWEEN
WEDNESDAY AND THURSDAY...SO HAVE LOWERED THURSDAY MAXES ACCORDINGLY.
I HAVE ALSO UPPED WIND SPEEDS A TAD AS THE LOW LEVEL CAA APPEARS
FAIRLY IMPRESSIVE ON ALL MODELS.
THIS FORECAST PERIOD ENDS WITH MODEL DIFFERENCES BECOMING MORE
GLARING. WITH RETURN FLOW...INCREASING CLOUDS AND MOISTURE AS STRONG
LOW LEVEL BOUNDARY SET THE STAGE FOR LIGHT -RA/-SN. ECMWF HAS A MORE
PROGRESSIVE AND FARTHER NORTH SYSTEM WHILE GFS MUCH SLOWER AND
FARTHER SOUTH. FOLLOWED GUIDANCE TO PAINT SWATH OF PRECIPITATION
MOVING WEST TO EAST LATE THURSDAY INTO FRIDAY. MADE A RASN MIX
DURING THE OVERNIGHT THURSDAY INTO EARLY FRIDAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
JR
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 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
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...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...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
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
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...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 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 GREEN BAY WI
1033 PM CDT FRI MAR 29 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 236 PM CDT FRI MAR 29 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
STRETCHING FROM THE SOUTHEAST CONUS TO THE WESTERN GREAT LAKES EARLY
THIS AFTERNOON. MID-LEVEL CLOUD DECK IS SLOWLY MOVING EAST OVER
WESTERN WISCONSIN AND IS APPROACHING CENTRAL WISCONSIN. A FEW
SPRINKLES HAVE BEEN REPORTED OVER MINNESOTA OUT OF THIS CLOUD DECK
BUT AIRMASS IS COMPARATIVELY DRIER OVER CENTRAL WISCONSIN...SO WILL
KEEP ANY MENTION OF SPRINKLES OUT OF THE FORECAST. SHORTWAVE
TROUGH... WHICH WILL BRING THE NEXT CHANCE OF PRECIP TOMORROW...IS
JUST ENTERING THE WESTERN DAKOTAS. AS THIS WAVE AND ATTENDANT COLD
FRONT APPROACHES...PRECIP CHANCES ARE THE MAIN FORECAST CONCERN.
TONIGHT...SURFACE HIGH PRESSURE WILL MOVE FROM THE CENTRAL TO THE
EASTERN GREAT LAKES...WHILE A SHEARED SHORTWAVE WILL PUSH A COOL
FRONT ACROSS THE NORTHERN PLAINS INTO THE NORTHERN MISSISSIPPI
VALLEY. SCT TO BKN LOW TO MID-DECK UPSTREAM WILL GRADUALLY MOVE
NORTHEAST THROUGH THE NIGHT...BUT DEEPER MOISTURE WILL NOT ARRIVE
INTO NORTHWEST WISCONSIN UNTIL LATE TONIGHT. SOUTH TO SOUTHWEST LOW
LEVEL WINDS WILL ADVECT IN DRY AIR FROM THE RECEDING AIRMASS...WHICH
WILL CAUSE LEVELS BELOW 5-6KFT TO STRUGGLE TO SATURATE. FIRST
THOUGHT WAS TO DELAY PRECIP CHANCES BECAUSE OF THIS DRY AIR...BUT AREAS
ACROSS THE NORTH MAY STILL REACH ENOUGH SATURATION FOR LIGHT RAIN TO
ARRIVE AFTER 09Z. SO WILL TREND A LITTLE SLOWER WITH THE PRECIP
CHANCES OVER CENTRAL AND NORTHEAST WISCONSIN...WHICH WILL KEEP THE
SE HALF OF THE AREA DRY BEFORE 15Z. THE DRY AIR SHOULD ALLOW TEMPS
TO FALL QUICKLY THIS EVENING AND WILL HAVE LOWS AROUND
MIDNIGHT...THEN TEMPS SHOULD RISE AS THICKENING CLOUDS ARRIVE. WET
BULB TEMPS LOOK TO BE SLIGHTLY ABOVE FREEZING OVER N-C WISCONSIN BY
THE TIME THE PRECIP ARRIVES...SO WILL KEEP A MENTION OF FREEZING
RAIN OUT OF THE FORECAST. THOUGH WILL MENTION TO THE EVENING CREW
TO WATCH TEMPS CLOSELY. LOWS IN THE UPPER 20S TO LOW 30S.
SATURDAY...WEAK SHORTWAVE WILL MOVE FROM NORTHERN MINNESOTA TO
EASTERN LAKE SUPERIOR AND WILL PUSH THE COOL FRONT ACROSS MOST OF
THE STATE EXCEPT FOR EASTERN WISCONSIN. WARM ADVECTION PRECIP OVER
NORTH-CENTRAL WISCONSIN WILL LIFT NORTH INTO THE UPPER PENINSULA
DURING THE EARLY MORNING. THEN THE 850MB THETAE AXIS WILL SHIFT
INTO CENTRAL WISCONSIN BY 15Z AND INTO EASTERN WISCONSIN AFTER 18Z.
PRECIP AMOUNTS SHOULD RANGE FROM A QUARTER TO A HALF INCH. HIGHS
MAINLY IN THE LOW TO MID 40S.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 236 PM CDT FRI MAR 29 2013
MODELS SHOWED A COLD FRONT...THAT WAS MOVING ACROSS
WISCONSIN...EXTENDING FROM NORTHEAST TO SOUTHWEST WISCONSIN AT 00Z
SUNDAY. HAVE KEPT LIKELY POPS FOR THE SOUTHEAST PART OF THE AREA
DURING THE EARLY PART OF THE EVENING...BUT THEN DOWN TO CHANCE
POPS BY LATE EVENING. HAVE A SLIGHT CHANCE FOR SNOW SHOWERS ACROSS
THE FAR NORTH LATE IN THE NIGHT AS COLD AIR PASSES OVER THE WARMER
LAKE SUPERIOR WATERS IN CYCLONIC FLOW. SNOW AND/OR RAIN SHOWERS
REMAIN POSSIBLE ON SUNDAY AS A SECONDARY COLD FRONT PUSHES THROUGH
WISCONSIN. THERE WILL BE A CHANCE OF SNOW SHOWERS SUNDAY NIGHT
AND MONDAY BUT THEY SHOULD MAINLY BE CONFINED TO VILAS COUNTY AS
WINDS BECOME LESS FAVORABLE FOR LAKE EFFECT IN MOST LOCATIONS.
CLOUDS AND THE COLD FRONT SHOULD KEEP TEMPERATURES MAINLY IN THE
30S IN THE FAR NORTH ON SUNDAY...AND THE ENTIRE AREA MONDAY AND
TUESDAY.
A SURFACE HIGH AND UPPER LEVEL RIDGE WILL BRING DRIER CONDITIONS
TO THE AREA FOR THE MIDDLE PART OF THE WEEK AND TEMPERATURES
SHOULD WARM UP A BIT WITH LESS CLOUD COVER. RETURN FLOW AROUND THE
HIGH SHOULD BRING NEAR NORMAL TEMPERATURES TO THE AREA ON
THURSDAY. ANOTHER SYSTEM APPROACHING THE AREA WILL BRING A SLIGHT CHANCE
OF PRECIPITATION FOR FRIDAY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1031 PM CDT FRI MAR 29 2013
WL INCREASE LLWS A LITTLE FM 00Z ISSUANCE. WL ALSO CARRY THE
POSSIBLITY OF SOME MIXED PCPN AT THE ONSET OVER THE NW PART OF THE
AREA. OTHERWISE...LITTLE CHG TO FCST THINKING. EXPECT BAND OF
SHRA TO WORK ACRS THE AREA SAT. CIGS MAY HOLD UP INITIALLY AS LOW-
LEVELS WL START OUT DRY. A BETTER CHC AT LOWER CIGS DEVELOPING IN
THE WAKE OF THE MAIN RAIN BAND AS WINDS DECR NEAR FRONTAL
BOUNDARY.
&&
.HYDROLOGY...
ISSUED AT 236 PM CDT FRI MAR 29 2013
EXPECT MILD TEMPERATURES FOR THE NEXT TWO DAYS...WITH
HIGHS IN MID TO UPPER 40S OVER THE FORECAST AREA. THIS WILL CONTINUE
THE GRADUAL MELTING OF THE SNOWPACK. RAIN IS EXPECTED SATURDAY INTO
SATURDAY EVENING...WITH PCPN AMOUNTS OF A QUARTER TO HALF INCH
POSSIBLE. GIVEN THIS SCENARIO...THE EXPECTED RUNOFF SHOULD CAUSE
A GRADUAL RISE IN THE RIVERS OVER THE FORECAST AREA THIS WEEKEND.
A FEW RIVERS IN EAST CENTRAL WISCONSIN COULD EXCEED BANKFULL.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......MG
AVIATION.......SKOWRONSKI
HYDROLOGY......MPC
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
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
355 AM EDT SAT MAR 30 2013
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW A GENERALLY
BENIGN UPPER LEVEL PATTERN IN PLACE OVER THE CONUS THIS MORNING.
CONVERGENT FLOW ARRIVES OVER THE PACIFIC NORTHWEST AND THEN FORMS A
GENERAL WEST TO NORTHWEST FLOW PATTERN ACROSS THE REMAINDER OF THE
CONUS. ONLY SIGNIFICANT ONGOING SENSIBLE WEATHER ARE THUNDERSTORMS
ACROSS THE PLAINS IN ASSOCIATION WITH A WEAK IMPULSE EJECTING OUT OF
THE INTER-MOUNTAIN WEST WITHIN THE MAIN FLOW. WV IMAGERY SHOWS OUR
FORECAST AREA RESIDES UNDER THIS GENERAL WESTERLY FLOW ALOFT AND
THIS IS CONFIRMED BY THE 30/00Z KTBW SOUNDING PROFILE. THE PROFILE
FROM LAST EVENING WAS STILL QUITE DRY THROUGH THE EXTENT OF THE
COLUMN...HOWEVER WE SHOULD SEE THE MID/UPPER LEVELS BEGIN TO MOISTEN
SOMEWHAT OVER THE NEXT 12-18 HOURS AS THE WEAK IMPULSE NOTED ABOVE
APPROACHES FROM THE NORTHWEST.
AT THE SURFACE...SURFACE HIGH PRESSURE IS RIDGING BACK WESTWARD OVER
THE PENINSULA AND EASTERN GULF FROM A POSITION CENTERED NORTH OF THE
BAHAMAS EARLY THIS MORNING. THE RIDGE AXIS AND CLEAR SKIES OVERHEAD
ARE ALLOWING YET ANOTHER COOL OVERNIGHT FOR LATE MARCH...HOWEVER
UNLIKE PREVIOUS MORNING...IT DOES NOT APPEAR AS THOUGH TEMPERATURES
WILL DROP ENOUGH FOR FROST TO BE A REAL CONCERN.
&&
.SHORT TERM (TODAY THROUGH MONDAY)...
TODAY/TONIGHT...
SURFACE HIGH PRESSURE OFF THE SE CONUS COAST WILL RIDGE BACK ACROSS
THE CENTRAL FL PENINSULA. EFFICIENT DIURNAL MIXING AND MODIFIED LOW
LEVEL AIRMASS SHOULD ALLOW AFTERNOON TEMPS TO REACH WELL UP INTO THE
70S NORTH AND INTO THE LOWER 80S SOUTH AWAY FROM THE BEACHES.
VIRTUALLY ALL NWP GUIDANCE IS SHOWING SEA-BREEZE DEVELOPMENT BY
EARLY AFTERNOON...AND WILL FOLLOW LOCAL HI-RES GUIDANCE FOR THE WIND
GRIDS IN TERMS OF TIMING AND STRENGTH FOR THE INLAND PROPAGATION OF
THE INITIAL BOUNDARY. THE SEA-BREEZE WILL HAVE MORE POTENTIAL FOR
SIGNIFICANT INLAND PENETRATION TO THE NORTH OF TAMPA BAY WHERE THE
GRADIENT FLOW ON THE NORTH SIDE OF THE RIDGE AXIS WILL AID IN THE
EASTWARD EXPANSION OF THE CIRCULATION. THE COOLEST SHELF WATERS IN
THE LOWER TO MIDDLE 60S ARE STILL FOUND OFF THE NATURE COAST...AND
THE ONSHORE FLOW OFF THESE WATERS IS LIKELY TO DROP TEMPS BACK DOWN
TOWARD THE UPPER 60S/LOW 70S NEAR THE COAST DURING THE SECOND HALF
OF THE AFTERNOON. WILL SEE SOME COOLING FOR THE SUNCOAST BEACHES
SOUTH OF TAMPA BAY AS WELL...HOWEVER THE WEAKER SEA-BREEZE AND
RELATIVELY WARMER SHELF WATERS SHOULD LIMIT THE COOLING. PLENTY OF
SUNSHINE WILL START THE DAY. DURING THE MIDDLE TO LATER PORTION OF
THE AFTERNOON TIME-HEIGHT PLOTS FROM THE GFS/NAM/ECMWF ALL SHOW AN
EVENTUAL INCREASE IN MID/HIGH LEVEL CLOUDS TO FILTER THE SUN IN
RESPONSE TO THE APPROACH OF A SHORTWAVE IMPULSE. TONIGHT STILL LOOKS
DRY AND SEASONABLY COOL. NO FROST CONCERNS EXPECTED WITH THE COOLEST
LOCATIONS ONLY DROPPING INTO THE UPPER 40S BY SUNRISE. SEVERAL MODEL
RUNS NOW HAVE SHOWN A DECENT SWATH OF MOISTURE COINCIDENT WITH
SYNOPTIC LIFT IN THE MID/UPPER LEVELS ASSOCIATED WITH THIS SHORTWAVE
DURING THE OVERNIGHT PERIOD. APPEARS TO BE ENOUGH FOR SKIES TO
POTENTIALLY GO MOSTLY CLOUDY NORTH OF I-4 FOR A PERIOD.
SUNDAY/SUNDAY NIGHT...
INITIAL SHORTWAVE QUICKLY PULLS EAST OF THE AREA DURING THE MORNING.
THE NEXT SHORTWAVE IN LINE ROTATING AROUND AN AMPLIFYING LONGWAVE
TROUGH WELL TO OUR NORTH WILL BE APPROACHING DURING THE DAY...BUT
SHOULD REMAIN FAR ENOUGH WEST TO HAVE LITTLE IMPACT DURING THE
DAYLIGHT HOURS. LEADING THIS ENERGY...A COLD FRONT WILL PUSH INTO
THE SOUTHEASTERN CONUS DURING THE DAY. THIS FRONT LOOKS TO STALL
NORTH OF I-10 LATER SUNDAY OR SUNDAY NIGHT. THE FORECAST PHILOSOPHY
HAS NOT CHANGED IN THE PAST 24 HOURS...AND ALTHOUGH IT IS NOT OUT OF
THE QUESTION TO SEE A BRIEF SHOWER OR TWO ACROSS LEVY/CITRUS
COUNTIES LATER SUNDAY/SUNDAY NIGHT...THE BETTER LOW LEVEL FOCUS FOR
LIFT REMAINS PROGGED TO STAY NORTH OF OUR ZONES. OF NOTE...THE
CONVECTIVE PARAMETRIZATION SCHEMES FROM A FEW OF THE SREF MEMBERS
ARE STILL KICKING OFF OVER THE PENINSULA (SOUTH OF I-4) DURING
SUNDAY AFTERNOON. THE GFS HAS BACKED OFF ON THIS SCENARIO...AND
SURFACE DEWPOINTS IN THE 50S SEEM TO ARGUE AGAINST ANY INSTABILITY
THAT WOULD CURRENTLY WARRANT SHOWER MENTION IN THE FORECAST.
AVAILABLE CONVECTION ALLOWING GUIDANCE ALSO SHOW LITTLE SHOWER
POTENTIAL AND WILL KEEP POPS AT SILENT 10%. TEMPERATURES WILL BE
SEASONABLE WITH UPPER 70S TO AROUND 80 NORTH OF I-4 AND LOW/MID 80S
FURTHER SOUTH. AFTERNOON SEA-BREEZES WILL AGAIN KEEP THE BEACHES
COOLER.
MONDAY...
SURFACE RIDGE AXIS WILL SETTLE A BIT SOUTH WHILE THE SURFACE COLD
FRONT REMAINS STALLED JUST TO THE NORTH OF I-10. AS THE NEXT
SHORTWAVE IN LINE CROSSES THE AREA...BETTER CHANCES FOR SHOWERS WILL
ARRIVE FOR THE NATURE COAST...ESPECIALLY NORTH OF HERNANDO COUNTY...
IN CLOSER PROXIMITY TO THE FRONTAL FOCUS. ALSO...SLIGHTLY BETTER
CHANCES FOR A FEW SEA-BREEZE FORCED SHOWERS MONDAY AFTERNOON FURTHER
SOUTH ACROSS THE PENINSULA DUE TO BETTER LOW LEVEL MOISTURE AND SOME
AIDED SUPPORT BY THE PASSING SHORTWAVE. BEST CHANCES TO SEE A BRIEF
SHOWER MONDAY AFTERNOON LOOK TO BE WELL INLAND FROM THE GULF...AND
MOST LIKELY OVER BY THE I-95 CORRIDOR WHERE SEA-BREEZE FOCUS WILL BE
MAXIMIZED. FOR NOW WILL SHOW A SLIGHT 20% CHANCE FOR THE AFTERNOON
SHOWERS TO THE EAST OF THE I-75 CORRIDOR. HIGH TEMPS INTO THE 80S
FOR MOST LOCATIONS AWAY FROM THE WATER.
&&
.LONG TERM (MONDAY NIGHT THROUGH NEXT FRIDAY)...
THE PERIOD BEGINS WITH ONE UPPER LOW OVER THE SIERRA NEVADA/GREAT
BASIN REGION AND A SECOND LOW OVER ONTARIO/QUEBEC...RESULTING IN
WESTERLY FLOW ALOFT THE GULF AND FL. AT THE SURFACE A FRONTAL
BOUNDARY WAS STRUNG OUT ALONG THE GULF COAST AND SE U.S. AS HIGH
PRESSURE RIDGED ACROSS FL FROM THE ATLANTIC TO THE GULF. THROUGH THE
REST OF THE WEEK - THE WESTERN LOW BECOMES AN OPEN TROUGH AS IT
TRACKS EASTWARD...REACHING THE EASTERN SEABOARD AND EAST GULF LATE
FRI. THE SURFACE RIDGE RETREATS EAST ALLOWING THE FRONTAL BOUNDARY
TO SAG IN ACROSS THE STATE AND WEAKEN THROUGH WED. MEANWHILE THE
APPROACHING UPPER TROUGH FORMS A INVERTED TROUGH/LOW OVER THE
WESTERN GULF THAT MOVES NORTHEASTWARD CROSSING THE GULF TO THE SE
U.S COASTAL WATERS FRI WITH A COLD FRONT SWEEPING INTO FL.
WITH SOME TIMING AND LOCATION DIFFERENCES BETWEEN THE MODELS HAVE
OPTED TO MAKE FEW CHANGES TO THE CURRENT FORECAST. CLOUDS ALONG WITH
RAIN CHANCES WILL BE INCREASING BUT HAVE KEPT POPS AT 40 PERCENT OR
LESS AND JUST SHOWERS FOR NOW. WINDS WILL BE PICKING UP MID AND LATE
WEEK BUT THAT WILL BE MORE OF A MARINE ISSUE AND HAVE CAPPED WINDS
AROUND 20 KNOTS. TEMPERATURES WILL RUN ABOVE NORMAL ALTHOUGH THEY
WILL COOL SLIGHTLY BY WEEKS END.
&&
.AVIATION...
VFR CONDITIONS FOR THE NEXT 24 HOURS WITH FEW-SCT CUMULUS UNDER SOME
CIRRUS. LIGHT VARIABLE WINDS INCREASE DURING THE MORNING THEN SHIFT
TO ONSHORE IN THE AFTERNOON.
&&
.MARINE...
HIGH PRESSURE WILL CONTINUE TO RIDGE WESTWARD ACROSS THE EASTERN
GULF OF MEXICO THROUGH THE WEEKEND. A WEAK COLD FRONT WILL APPROACH
FROM THE NORTH LATER MONDAY...BUT LIKELY WASH OUT BEFORE REACHING
THE NORTHERN WATERS ON TUESDAY. WINDS AND SEAS ARE FORECAST TO
REMAIN BELOW HEADLINE CRITERIA DURING THE NEXT SEVERAL DAYS.
SEA-BREEZE CIRCULATIONS DEVELOPING THIS AFTERNOON AND AGAIN ON
SUNDAY AFTERNOON WILL TURN WINDS ONSHORE NEAR THE COAST.
&&
.FIRE WEATHER...
ANOTHER DRY DAY ACROSS THE REGION WITH SURFACE HIGH PRESSURE IN
CONTROL. MINIMUM RELATIVE HUMIDITY VALUES AWAY FROM THE COAST WILL
DROP INTO THE UPPER 20S...WITH UP TO 6 HOUR OF CRITICAL RELATIVE
HUMIDITY VALUES POSSIBLE. A DEVELOPING SEA-BREEZE SHOULD HELP TO
BRING INCREASED LOW LEVEL MOISTURE TO LOCATIONS CLOSE TO THE COAST
DURING THE SECOND HALF OF THE AFTERNOON. A RED FLAG WARNING REMAINS
IN EFFECT FOR POLK...HIGHLANDS...AND LEE COUNTIES WHERE RELATIVE
HUMIDITY AND ERC VALUES MEET CRITERIA. A SLOW INCREASE IN LOW LEVEL
MOISTURE WILL LIKELY PREVENT CRITICAL DURATIONS OF LOW RELATIVE
HUMIDITY ON SUNDAY ALTHOUGH A FEW HOURS OF SUB 35 PERCENT READINGS
WILL BE POSSIBLE EAST OF THE I-75 CORRIDOR. A FURTHER INCREASE OF
LOW LEVEL MOISTURE SHOULD END FIRE WEATHER CONCERNS BY MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 75 58 79 63 / 0 0 0 10
FMY 80 60 85 63 / 0 0 10 10
GIF 79 55 82 61 / 0 0 10 10
SRQ 74 58 78 62 / 0 0 0 10
BKV 77 49 81 57 / 0 10 0 10
SPG 75 62 79 65 / 0 0 0 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RED FLAG WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING
FOR HIGHLANDS-LEE-POLK.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...RUDE
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1122 PM CDT FRI MAR 29 2013
.SYNOPSIS...
ISSUED AT 318 PM CDT FRI MAR 29 2013
H5 HAND ANALYSIS THIS MORNING IS INDICATING BROAD LOW
AMPLITUDE FLOW ACROSS THE LOWER 48...WITH EMBEDDED SHORTWAVES NOTED
OVER THE NORTHERN ROCKIES OF IDAHO AND MONTANA. ABUNDANT MID LEVEL
INSTABILITY AND MID LEVEL ALTO CU HAS TRACKED INTO WESTERN AND
CENTRAL NEBRASKA THIS MORNING...WITH RADAR INDICATING HIGHLY
ELEVATED SHOWERS...NONE OF WHICH IS REACHING THE GROUND ATTM. AT THE
SURFACE...A LEE SIDE TROUGH HAS BEGUN TO DEEPEN ACROSS THE PANHANDLE
AND FAR EASTERN COLORADO OVER THE PAST COUPLE OF HOURS. THIS HAS
RESULTED IN INCREASED SRLY WINDS THIS AFTERNOON AND INCREASED LOW
LEVEL MOISTURE...WITH DEW POINTS BEGINNING TO REACH INTO THE LOWER
40S AS OF 3 PM CDT. TEMPERATURES AS OF 3 PM CDT RANGED FROM 64
DEGREES AT VALENTINE TO 71 DEGREES AT OGALLALA.
&&
.UPDATE...
ISSUED AT 817 PM CDT FRI MAR 29 2013
THE SHOWERS AND THUNDERSTORMS HAVE LARGELY MOVED OFF TO THE EAST.
GIVEN THE RESIDUAL MOISTURE ALOFT WHICH WILL REMAIN IN PLACE THROUGH
SATURDAY EVENING. ISOLATED SHOWERS ARE POSSIBLE THROUGH MIDNIGHT
TONIGHT AND THEN AGAIN SATURDAY MORNING WITH SHOWERS AND
THUNDERSTORMS POSSIBLE SATURDAY AFTERNOON AS ANOTHER DISTURBANCE
MOVES THROUGH IN THE NORTHWEST FLOW ALOFT.
A NEW FORECAST IS OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 318 PM CDT FRI MAR 29 2013
MAIN FORECASTING CHALLENGES
OVER THE NEXT 24 HOURS ARE THUNDERSTORM POTENTIAL AND ASSOCIATED
PRECIPITATION CHANCES TONIGHT...THEN LOW PRECIPITATION CHANCES FOR
SATURDAY...IN PARTICULAR SATURDAY AFTERNOON. FOR TONIGHT...AM
EXPECTING SOME ISOLATED TSRA INITIATION INVOF OF SURFACE TROUGH AXIS
LATER THIS AFTERNOON. BASED ON THE LATEST NAM AND RUC SOLNS...THIS
SHOULD BE SOMEWHERE FROM AROUND OGALLALA TO NORTHERN CHERRY COUNTY
BY 21Z THIS AFTERNOON. AM EXPECTING ISOLATED CONVECTION TO FIRE
INVOF OF THIS FEATURE DURING THE 21Z TO 00Z TIME FRAME LATER THIS
AFTERNOON. DECENT MID LEVEL FLOW...WILL TRACK ANY ISOLATED
CONVECTION QUICKLY EAST INTO THE CENTRAL AND EASTERN CWFA LATER THIS
EVENING AND OVERNIGHT. CONVECTION IS EXPECTED TO BECOME BETTER
ORGANIZED IN THE EASTERN CWFA OVERNIGHT AS A NICE LOW LEVEL JET
PUSHES NORTH INTO EASTERN NEBR...THE NOSE OF WHICH PUSHES INTO OUR
NERN ZONES. FOR PRECIPITATION CHANCES TONIGHT...FAVORED POPS AROUND
20 PERCENT...ALONG AND WEST OF HIGHWAY 83...INCREASING THEM EASTWARD
TO AROUND 50 PERCENT IN THE NERN CWA. AS FOR THE THREAT OF SEVERE
THUNDERSTORMS TONIGHT...THE LATEST SWODY1 HAS A SEE TEXT ACROSS OUR
SWRN ZONES AND CENTRAL SANDHILLS MAINLY FOR EARLY EVENING CONVECTION
TIED TO PEAK HEATING. AT THIS JUNCTURE...SOME GUSTY WINDS MAY
ACCOMPANY THE STRONGEST STORMS GIVEN THE DRY CONDS BLO 10000 FT AGL
AND EXPECTED HIGH BASED TSRAS IN THE WEST. EVEN IN LIGHT OF WET BULB
ZEROES OF AROUND 9000 FT MSL...LARGE HAIL THREAT WILL BE MINIMAL AS
DEEP LAYER SHEAR IS ONLY AROUND 30 KTS AND FREEZING LEVELS ARE
AROUND 5 TO 7 THOUSAND FT AGL.
FOR SATURDAY...NORTHWESTERLY WINDS WILL DEVELOP BEHIND EXITING LOW
PRESSURE AND MAY BECOME GUSTY DURING THE AFTERNOON HOURS. WITH
SURFACE HEATING...MID LEVEL LAPSE RATES WILL STEEPEN SIGNIFICANTLY
DURING THE AFTERNOON HOURS...AND WILL CONTINUE MENTION OF ISOLATED
SHOWERS. LI`S ARE BARELY NEGATIVE TOMORROW AFTERNOON AND WILL FORGO
MENTION OF THUNDER ATTM. HIGHS SATURDAY WILL BE COOLER THAN TDYS
READINGS. BASED ON H85 TEMPS AND GOOD MIXING...HIGHS WILL RANGE FROM
THE 50S NORTH...TO THE LOWER 60S IN THE SOUTH.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 318 PM CDT FRI MAR 29 2013
SATURDAY NIGHT WILL SEE A DISTURBANCE PUSHING SOUTH AND AN ARCTIC
COLD FRONT DIPPING SOUTH ACROSS THE NORTHERN PLAINS. BY SUNDAY
AFTERNOON THE COLD FRONT WILL BE PUSHING INTO NRN NEBRASKA. SHOULD
SQUEAK OUT ANOTHER NICE DAY WITH HIGHS IN THE 60S FOR MOST OF THE
CWA. PORTIONS OF NORTH CENTRAL WILL SEE HIGHS ONLY IN THE 50S AS THE
COLD FRONT ARRIVES BEFORE PEAK HEAT. ALSO GOING TO SEE SOME SHOWERS
DEVELOP ALONG/AHEAD OF THE FRONT...MAINLY WHERE THERE IS BETTER
MOISTURE TO THE EAST. BY SUNDAY NIGHT COLD AIR WILL PUSH ACROSS THE
AREA. NOT A GREAT CHANCE FOR PRECIP...BUT COLD AIR ALOFT WILL CREATE
SOME STEEP LAPSE RATES. ALSO AS TEMPS FALL A MIX OR CHANGE TO SNOW
CAN BE EXPECTED.
MONDAY WILL FEEL THE COLD ARCTIC AIR AS HIGHS ONLY WARM INTO THE MID
30S TO MID 40S. PRECIP WILL BE PUSHING SOUTH...SO HIGHS MAY ACTUALLY
BE ABLE TO WARM UP A LITTLE MORE THAN FORECAST AS APRIL SUNSHINE
ARRIVES FOR THE AFTERNOON.
COLD AIR IS SHORT LIVED AS CENTER OF HIGH SHIFTS TO THE EAST FOR
TUESDAY...WITH RETURN SOUTHERLY FLOW BY TUESDAY AFTERNOON. NOT A
FAST REBOUND ON TUESDAY AS HIGHS ONLY IN THE 40S TO LOW 50S.
WEDNESDAY INTO THURSDAY WILL CONTINUE TO SEE A REBOUND OF TEMPS.
SURF HIGH CONTINUES TO PUSH TO THE SE WITH MORE WARM AIR TO PUSH
NORTHWARD AND THE BACKSIDE OF THE HIGH. 850 MB TEMPS PUSH INTO THE
SINGLE DIGITS ABOVE ZERO AND CLOSE TO 10 IN THE WEST WITH GUIDANCE
CLOSE TO 60. PRECIP CHANCES DO NOT LOOK GOOD THROUGH THE WEEK...AS
GULF MOISTURE REMAINS SHUT OFF AND MODELS CONTINUE A DRY BL. AN
UPPER LEVEL DISTURBANCE LATE IN THE WEEK MAY BRING SOME LIGHT
PRECIP...BUT WILL HAVE TO BE A TOP DOWN SATURATION AND DO NOT HAVE
IN THE FORECAST ATTM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1122 PM CDT FRI MAR 29 2013
VFR IS GENERALLY EXPECTED OVERNIGHT THROUGH 20Z.
THEREAFTER...ANOTHER UPPER LEVEL DISTURBANCE...CURRENTLY ACROSS
SCNTL MT...WILL MOVE SOUTHEAST THROUGH WESTERN AND SOUTH CENTRAL
NEBRASKA PRODUCING ISOLATED TO SCATTERED SHRA AND TSTM COVERAGE.
THESE STORMS ARE EXPECTED TO EXIT THE FCST AREA BY AROUND 03Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS TULSA OK
457 AM CDT SAT MAR 30 2013
.DISCUSSION...
WAVE TRAIN ROLLING ALONG IN NORTHWEST FLOW HAULING
CLUSTERS OF SHOWERS AND THUNDERSTORMS THIS MORNING.
SOME OF THE STRONGER THUNDERSTORMS PROVED EFFICIENT
HAIL PRODUCERS OVERNIGHT.
IN THE SHORT TERM FOLLOWED HRRR MODEL WHICH HAS BEEN
GOOD LAST SIX HOURS WITH CONVECTIVE ACTION. BULK OF
CURRENT PRECIP EAST OF NORTHWEST AR ZONES AROUND 18Z.
QUESTION THEN BECOMES WHAT BOUNDARIES ARE LEFT BEHIND
TO FIRE LATE AFTERNOON..OR EVENING. TEMPERATURES INTO
THE MID 70S THIS AFTERNOON..IN ADVANCE OF A WEAK COOL
FRONTAL BOUNDARY SAGGING INTO THE FORECAST AREA WILL
LIKELY IGNITE ANOTHER ROUND OF THUNDER. CAPE VALUES
IN THE 2000 J/KG NEIGHBORHOOD AND SUFFICIENT SHEAR
WILL BE CAPABLE OF LARGE HAIL PRODUCTION.
CONVECTION MIGRATING SOUTHEAST OVERNIGHT LEAVING MOST
AREAS NORTH OF INTERSTATE 40 WITH A DRY WARM EASTER.
SHOWERS THUNDER MOST LIKELY NEAR OR SOUTH OF THE RED
RIVER.
NEXT WAVE AND REAL COLD FRONT ARRIVE SOMETIME MONDAY.
WRF VERY FAST AND THE OUTLIER IN BRINGING IN THE COLD
AIR COMPARED TO MOST OF THE OTHER MODELS. RESULTING
WRF MOS BASED MAX TEMPS SOME 15 TO 20 DEGREES COLDER
FOR NORTHERN LOCATIONS. USED FOUR MODEL MAX TEMP.
MODEL DIFFERENCES CONTINUE TO PLAGUE THE MIDWEEK TIME
PERIOD. ECMWF CONSISTENT WITH ITSELF BRINGING AN UPPER
LOW DIRECTLY OVER FORECAST AREA. MEANWHILE GFS WEAKER
DRIER... MORE PROGRESSIVE WITH THE FEATURE. ECMWF TOO
GOOD TO TOTALLY IGNORE..CHANCE POPS MIDWEEK.
GW
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 77 51 73 43 / 50 60 10 10
FSM 73 56 74 48 / 80 60 30 10
MLC 75 55 73 48 / 50 60 30 10
BVO 76 46 72 40 / 40 50 10 10
FYV 69 51 70 42 / 90 70 20 0
BYV 67 49 69 41 / 90 70 10 0
MKO 75 54 72 46 / 60 60 20 10
MIO 71 47 71 42 / 70 60 0 10
F10 76 54 72 47 / 50 60 20 10
HHW 74 57 72 53 / 60 60 60 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...18
LONG TERM....21
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
831 AM PDT SAT MAR 30 2013
.DISCUSSION...AS OF 8:29 AM PDT SATURDAY...IR SATELLITE AND KMUX
PRETTY MUCH SAY IT ALL...A STORM SYSTEM IS APPROACHING THE BAY
AREA WITH A MIXTURE OF CLOUDS AND SHOWERS. AS MENTIONED ON THE
PREVIOUS DISCUSSION...MUCH OF THE SHORT TERM WEATHER CONCERNS WILL
BE ASSOCIATED WITH A SFC LOW NEAR 34N/132W. KMUX RADAR IMAGERY
CONTINUES TO INDICATE SHOWER ACTIVITY OFF THE NORTH BAY COAST AND
PARTS OF THE NORTH BAY. HOWEVER...THESE SHOWERS ARE BEING DETECTED AT
ROUGHLY 10-12K FEET AGL. THE MORNING KOAK SOUNDING SHOWS A MOIST
LAYER AROUND 10K FEET...BUT A LARGE DRY POCKET OF AIR JUST BELOW
10K FEET. THE ECHOES DETECTED ON RADAR ARE PROBABLY NOT REACHING
THE GROUND. THIS IS FURTHER CONFIRMED BY THE LACK OF SFC REPORTS
FOR MEASURABLE PRECIP. THAT BEING SAID...PATCHY STRATUS DOES EXIST
ALONG THE COAST WITH LIGHT DRIZZLE BEING REPORTED. ALSO...DURING
THE MORNING HOURS A FEW SPRINKLES MAY BE POSSIBLE WITH THE RADAR
ECHOES...BUT WIDESPREAD SHOWERS SEEMS UNLIKELY.
NO UPDATE PLANNED AT THIS TIME. WILL CONTINUE TO MONITOR
DEVELOPING SHOWERS AND APPROACHING STORM SYSTEM. THERE WILL BE A
BETTER CHANCE FOR SHOWERS LATE THIS AFTERNOON AND EVENING AS THE
PARENT SFC LOW MOVES CLOSER TO THE COAST. IN FACT...SOME OF THE
12Z MODEL GUIDANCE...INCLUDING THE RAP AND HRRR...KEEP THE BULK OF
THE MOISTURE OFF THE COAST UNTIL AFTER 00Z SUNDAY. THE OTHER
INTERESTING ITEM OF NOTE...THE NAM12 FCST SOUNDINGS STILL DEVELOP
CONVECTION OVER THE NORTH BAY THIS AFTERNOON...CAPE 500 J/KG WITH
LITTLE CIN AND LI/S MINUS 3. NOT TOTALLY BUYING OFF ON THIS YET
GIVEN THE CLOUD COVER/WEAK MARINE LAYER AND LACK OF SOLAR HEATING
EXPECTED. BETTER CHANCE FOR CONVECTION ON SUNDAY AS THE UPPER LOW
AND COLD AIR ALOFT PASS OVERHEAD.
THE BULK OF THE RAIN STILL LOOKS TO OCCUR DURING THE OVERNIGHT
HOURS TONIGHT AND SUNDAY. HIGH PRESSURE BUILDS OVER THE REGION ON
MONDAY AND ANY LINGERING SHOWERS WILL DIMINISH. NAILING DOWN
PRECIP AMOUNTS IS SOMEWHAT PROBLEMATIC GIVEN THE CONVECTIVE NATURE
OF PRECIP TONIGHT THROUGH EARLY MONDAY. FOR NOW...BEST GUESS
CONTINUES INDICATE A FEW TENTHS OVER THE LOWER ELEVATIONS AND UP
TO ONE INCH OVER THE COASTAL MOUNTAINS.
PREVIOUS...THE NEXT RAIN CHANCES WILL OCCUR WEDNESDAY NIGHT AND THURSDAY AS
AN UPPER TROUGH MOVES ONTO THE COAST...WITH ANOTHER SYSTEM
POSSIBLE BY NEXT WEEKEND.
&&
.AVIATION...AS OF 4:47 AM PDT SATURDAY...CURRENTLY THE IR
SATELLITE IMAGE IS SHOWING MID TO HIGH CLOUDS AND SOUTHERLY FLOW
OVER THE FORECAST AREA. THE GOES IFR PROB PROD IS INDICATING IFR
PROB GREATER THAN 60% OVER PORTIONS OF SAN FRANCISCO BAY WITH KOAK
OB INDICATING BKN005. SOUTHERLY FLOW SHOULD HELP TO KEEP THE LOW
CIGS OUT OF KSFO BUT THERE MAY BE SOME IFR CIGS OVER THE APPROACH.
RUNWAYS SHOULD REMAIN DRY THIS MORNING WITH SHOWERS EXPECTED TO
DEVELOP LATER THIS EVENING.
VICINITY OF KSFO...VFR IS ANTICIPATED TODAY WITH A LOW PROBABILITY
OF IFR CIGS THIS MORNING. IF IFR DOES DEVELOP CONDITIONS SHOULD
IMPROVE NO LATER THAN 1700Z. GENERALLY LIGHT WINDS WILL INCREASE
OUT OF THE SOUTHWEST TO 10 TO 12 KT BY 2100Z.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO WITH A HIGHER PROB OF IFR
CIGS THIS MORNING. IF IFR CIGS DO DEVELOP CONDITIONS SHOULD
IMPROVE BY 1700Z.
MONTEREY BAY AREA TERMINALS...LIFR CIGS THIS MORNING WILL IMPROVE
TO IFR BY 1700Z WITH CONTINUED IMPROVEMENT TO VFR BY 2000Z.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: MM
AVIATION/MARINE: LARRY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS TAUNTON MA
706 AM EDT SAT MAR 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL BRING DRY AND MILD WEATHER TO THE REGION TODAY
INTO MOST OF SUNDAY AFTERNOON. AN APPROACHING COLD FRONT WILL BRING
A PERIOD OF SHOWERS TO THE REGION SUN NIGHT WITH EVEN THE RISK FOR
AN ISOLATED THUNDERSTORM. ANOTHER COLD FRONT WILL BRING COLDER
WEATHER INTO THE MID PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
MID LVL SHORTWAVE IS NOW BEGINNING TO SHIFT E OF THE FORECAST AREA
EARLY THIS MORNING. THIS IS ALLOWING BOTH SOME LOW TO MID STRATO-
CU AND SOME LIGHT SHOWERS OVER THE ISLANDS TO BEGIN SHIFTING E OF
THE AREA...GIVING WAY TO MOSTLY SKC CONDITIONS ACROSS MUCH OF THE
INTERIOR. THE TREND WILL BE TOWARD THIS CLEARING EVEN IN THE E.
WILL STILL NEED TO MONITOR FOR THE SLIGHT CHANCE OF AN AFTERNOON
SHOWER PARTICULARLY IN THE SE...BUT IT APPEARS MUCH OF THE AY WILL
BE DRY. THEREFORE WILL CONTINUE WITH NIL POPS. ADJUSTED SKIES
TOWARD LATEST RAP AND ALSO UPDATED TEMPS AND DWPTS TO BRING THEM
UP TO CURRENT TRENDS.
PREVIOUS DISCUSSION...
A MID LEVEL SHORTWAVE WAS RESULTING IN A FEW LINGERING
SPRINKLES/LIGHT SHOWERS ACROSS THE CAPE AND ISLANDS VERY EARLY THIS
MORNING. THIS ACTIVITY SHOULD EXIT THE REGION BY DAYBREAK.
OTHERWISE...A PARTLY TO MOSTLY SUNNY AND MILD DAY IS ON TAP FOR THE
REGION. ALTHOUGH 850 MB TEMPS ARE AROUND -3C...DRY NORTHWEST FLOW
AND A WELL MIXED ATMOSPHERE WILL YIELD A SUPER ADIABATIC ATMOSPHERE.
HIGH TEMPS SHOULD RISE INTO THE MID TO UPPER 50S...AND ITS NOT OUT
OF THE QUESTION THAT A FEW SPOTS HIT THE 60 DEGREE MARK. GIVEN THE
RELATIVELY WEAK PRESSURE GRADIENT...SEA BREEZES MAY DEVELOP ALONG
THE VERY IMMEDIATE COAST RESULTING IN LOCALIZED COOLER CONDITIONS IN
THOSE REGIONS DURING AFTERNOON.
WE KEPT THE FORECAST DRY AS UPPER LEVEL TROUGH IS MOVING EAST AND
ALLOWING FOR RISING HEIGHT FIELDS IN SOUTHERN NEW ENGLAND. GUESS
THERE IS STILL A LOW RISK OF AN ISOLATED SPOT SHOWER NEAR THE
SOUTHEAST NEW ENGLAND COAST THIS AFTERNOON...BUT NOT WORTH
MENTIONING IN THE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
TONIGHT...
A RIDGE OF HIGH PRESSURE BUILDS OVER THE REGION. THIS WILL RESULT
IN MAINLY CLEAR SKIES/LIGHT WINDS AND A GOOD NIGHT OF RADIATIONAL
COOLING. DESPITE THE MILD DAY...LOW TEMPS SHOULD FALL WELL DOWN
INTO THE 20S TO LOWER 30S IN MOST LOCALES BY DAYBREAK SUN.
SUNDAY AND SUNDAY NIGHT...
THE RIDGE OF HIGH PRESSURE MOVES OFF THE
COAST EARLY ON SUN...ALLOWING FOR A SOUTHERLY FLOW OF MILD AIR TO
WORK INTO THE REGION. WHILE CLOUDS WILL INCREASE DURING THE
AFTERNOON FROM WEST TO EAST...A FAIR AMOUNT OF SUNSHINE IS EXPECTED
FOR THE FIRST PART OF THE DAY. THIS SHOULD ALLOW HIGH TEMPS TO
REACH INTO THE UPPER 50S TO AROUND 60 NORTHWEST OF BOS TO PVD LINE.
SOUTHERLY FLOW OFF THE OCEAN WILL RESULT IN TEMPS A BIT COOLER
SOUTHEAST OF THIS REGION...WITH HIGHS HELD DOWN INTO THE UPPER 40S
AND LOWER 50S ACROSS THE CAPE/ISLANDS.
EXPECT THE WEATHER TO PRETTY MUCH REMAIN DRY DURING THE DAY SUNDAY.
A COLD FRONT APPROACHING FROM THE WEST WILL BRING A BAND OF SHOWERS
ACROSS THE REGION SUNDAY NIGHT FOR A FEW HOURS. THERE MAY BE JUST
ENOUGH ELEVATED INSTABILITY FOR A FEW EMBEDDED THUNDERSTORMS...WITH
THE BEST CHANCE ALONG THE SOUTHEAST NEW ENGLAND COAST. THE MODELS
INDICATE THAT TOTAL TOTALS MAY RISE INTO THE MID 50S WITH SHOWALTERS
DROPPING TO AROUND ZERO...SO HAVE INSERTED SOME ISOLATED THUNDER
INTO THE FORECAST. THE FRONT WILL BE FAST MOVING SO SHOWERS SHOULD
ONLY LAST A FEW HOURS IN A GIVEN LOCATION...WITH RAINFALL AMOUNTS
LESS THAN A HALF INCH.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
* WARMER TEMPERATURES EXPECTED MON THEN COOLING
* COOLER WEATHER MOVES BACK IN TUES AND WED
* WARMING THU AND FRI...BUT WILL HAVE TO WATCH OCEAN STORM
OVERVIEW AND MODEL PREFERENCES...
30/00Z MODEL GUIDANCE SUITE CONTINUES TO SHOW REASONABLY GOOD
AGREEMENT THROUGH MUCH OF THE LONG TERM AND HAS BEEN DELAYING THE
BREAKDOWN OF BLOCKING GREENLAND RIDGE. CPC CONTINUES TO SHOW A
NEGATIVE AO PATTERN NOW INTO EARLY APRIL...WHICH SUPPORTS THIS
THINKING. THE RIDGE LOOKS TO REMAIN IN PLACE THROUGH MUCH OF THE
COMING WEEK AND THEREFORE HOLDS CUTOFF LOW PRES IN VICINITY OF
NEWFOUNDLAND AND LABRADOR. THIS SETUP SUGGESTS TEMPERATURES
GENERALLY REMAIN ON THE COOL SIDE OF NORMAL FOR MUCH OF THE WEEK.
OPERATIONAL GFS AND ECMWF ARE BOTH IN AGREEMENT HERE...BUT THE
ECMWF CONTINUES TO BE A BIT COLDER...AND SEEMS TO HAVE BEEN MORE
PERSISTENT. THEREFORE...WILL CONTINUE WITH USING IT AS A BASELINE.
DETAILS...
MON INTO MON NIGHT...
FOLLOWING OCCLUSION IN THE MORNING EXPECT A BRIEF LULL IN
PRECIPITATION LIKELY UNTIL MID TO LATE AFTERNOON THANKS TO A
FAIRLY ROBUST DRY SLOT IN ADVANCE OF AN ARCTIC COLD FRONT. THIS
SECONDARY FRONT IS EXPECTED TO MOVE THROUGH BETWEEN 18Z AND 00Z
TUE...WITH SOME ISOLATED RAIN SHOWERS INITIALLY. GIVEN A FAIR
AMOUNT OF COLD DRY AIR ADVECTING IN RAPIDLY...MAY ACTUALLY SEE A
BRIEF CHANGE OVER TO SOME SNOW SHOWERS TOWARD THE END OF THE DAY.
AT THIS POINT...GIVEN THE WARM START /H85 TEMPS START HIGHER THAN
0C/ WILL LIKELY SEE LITTLE ACCUMULATION IF ANY UNLESS A BRIEF
HEAVIER SNOW SHOWER OCCURS IN WHICH DYNAMIC COOLING IS ENOUGH FOR
BETTER SNOW DEVELOPMENT. MAY SEE SOME WIND GUSTS EXCEEDING 30 MPH
ESPECIALLY WITH THE FRONT...BUT EXPECT THAT MOST GUSTS SHOULD
REMAIN BELOW WIND ADVISORY CRITERIA.
TUE AND WED...
ARCTIC FRONT MOVES FURTHER OFFSHORE TUE AND DRY HIGH PRES BEGINS
TO BUILD IN FROM THE W. THIS ALLOWS THE CONTINUED COOL NW FLOW
OVER THE REGION. MAY SEE SOME CLOUDS AND LIGHT SHOWERS
PARTICULARLY IN THE NW THANKS TO DECENT MID LVL COLD
ADVECTION...BUT OTHERWISE THE BEGINNING OF A MOSTLY DRY PERIOD IS
EXPECTED. EXPECTING THE CONTINUATION OF SOME 20 TO 30 MPH WIND
GUSTS PARTICULARLY DURING THE DAY...SO IT WILL BE BLUSTERY. H85
TEMPERATURES ARE EXPECTED TO HOVER CLOSE TO ABOUT -10C...SO
TEMPERATURES IN THE LOW TO MID 40S ARE LIKELY GIVEN THE EARLY
APRIL SUN.
THU INTO FRI...
HIGH PRES BUILDS OVER THE REGION DURING THIS PERIOD. AT THIS
POINT...MOST LONG RANGE GUIDANCE SUGGESTS THE BLOCKING HIGH SHIFTS
INTO THE MARITIMES AND SETS UP SUCH THAT SRN STREAM WAVE STAYS TOO
FAR OFFSHORE TO AFFECT THE REGION. HOWEVER...THIS WILL NEED TO BE
MONITORED SHOULD THE BLOCK SHIFT TO THE N...WHICH MAY ALLOW THIS
COASTAL LOW TO AFFECT THE REGION. THE 00Z ECMWF DOES SHOW THIS
MAKING A CLOSE ENOUGH PASS...SUCH THAT PRECIP MAY FALL...HOWEVER
WILL CONTINUE TO HOLD THE DRY TREND CONSIDERING THIS IS THE FIRST
RUN AND MANY OF ITS ENSEMBLE MEMBERS CONTINUE TO BE FURTHER
OFFSHORE. EXPECTING A SLIGHT MODERATING TREND IN TEMPERATURES AS
HIGH PRES SLIDES E AND SOME WEAK WARM ADVECTION DEVELOPS.
NEXT WEEKEND...
WHILE THIS WILL BE DEPENDENT SOMEWHAT ON EXACTLY WHAT THE SRN
STREAM WAVE DOES...IT APPEARS THAT SOME HIGH PRES WILL BUILD BACK
OVER THE REGION BY NEXT WEEKEND. ALLOWING FOR A GENERAL DRYING
TREND.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW...HIGH CONFIDENCE THROUGH SUNDAY AFTERNOON. MODERATE
CONFIDENCE SUNDAY NIGHT.
VFR CONDITIONS TODAY THROUGH SUNDAY AFTERNOON.
OTHERWISE...MVFR CONDITIONS BEGIN WITH A BAND OF RAIN MOVING FROM
W TO E BY SUN AFTERNOON...MVFR WILL LIKELY ACCOMPANY THIS RAIN
ALTHOUGH CAN/T RULE OUT A BRIEF PERIOD OF IFR. THERE ALSO MAY BE
A FEW EMBEDDED THUNDERSTORMS WITH THE BEST CHANCE ALONG THE
COASTAL PLAIN DURING THE EVENING AND EARLY OVERNIGHT SUN NIGHT..
KBOS TAF...HIGH CONFIDENCE IN VFR CONDITIONS TODAY AND TONIGHT.
WILL HAVE TO MONITOR FOR ANOTHER WEAK SEA BREEZE FOR A COUPLE OF
HOURS THIS AFTERNOON. WILL TIME THIS IN THE TAF...AND WILL HAVE TO
MONITOR THE STRENGTH OF THE SFC WIND...SHOULD IT DIMINISH THIS
AFTERNOON THE CHANCE OF THE SEA BREEZE COMING ON SHORE IS HIGHER.
KBDL TAF...HIGH CONFIDENCE IN TAF TODAY AND TONIGHT.
OUTLOOK...MONDAY THROUGH WEDNESDAY...
MONDAY...MODERATE CONFIDENCE IN MAINLY VFR CONDITIONS. HOWEVER...A
SECONDARY FRONT MAY BRING ISOLATED MVFR CONDITIONS LATE DAY MON.
TUESDAY AND WEDNESDAY...HIGH CONFIDENCE.
MAINLY VFR.
&&
.MARINE...
HIGH CONFIDENCE THROUGH SUNDAY AFTERNOON THAT WINDS/SEAS WILL REMAIN
BELOW SCA THRESHOLDS WITH A RELATIVELY WEAK PRESSURE GRADIENT IN
PLACE. AN APPROACHING COLD FRONT WILL LIKELY BRING A PERIOD OF
SOUTHERLY SCA WIND GUSTS AND SEAS TO THE WATERS SUNDAY NIGHT. SINCE
ITS A 4TH PERIOD EVENT...IT WAS TOO EARLY TO ISSUE ANY MARINE
HEADLINES.
OUTLOOK...MONDAY THROUGH WEDNESDAY...
MODERATE TO HIGH CONFIDENCE.
AFTER A SERIES OF FRONTS SUN NIGHT AND MONDAY...EXPECT NW WINDS TO
BUILD AND MAINTAIN AROUND 25 TO 30 KT AT TIMES FROM LATE DAY MON
INTO WED. SEAS MAY DROP A BIT ESPECIALLY ON NEAR SHORE
WATERS...BUT WILL LIKELY REMAIN ABOVE 5 FT OVER OUT WATERS. SMALL
CRAFT ADVISORIES ARE LIKELY FROM MON INTO WED.
LOW PROBABILITY OF SOME ISOLATED GALE FORCE WIND GUSTS DURING THIS
PERIOD AS WELL.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...FRANK/DOODY
SHORT TERM...FRANK
LONG TERM...DOODY
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1006 AM CDT SAT MAR 30 2013
.UPDATE...
ISSUED AT 955 AM CDT SAT MAR 30 2013
UPDATED FORECAST TO REMOVE POPS THIS MORNING ACROSS MUCH OF THE
AREA. SCATTERED SHOWERS WILL CONTINUE ACROSS BROWN...NORTHERN
JACKSON AND NORTHERN JEFFERSON THROUGH NOON.
SHOWERS AND THUNDERSTORMS WILL REDEVELOP AHEAD OF A COLD FRONT
ACROSS NORTHEAST AND EAST CENTRAL KS THIS AFTERNOON. IF WE GET
INSOLATION LATE THIS MORNING AND DURING THE AFTERNOON HOURS...THE
ATMOSPHERE MAY DESTABILIZE ENOUGH DURING THE AFTERNOON HOURS FOR SOME
OF THE THUNDERSTORMS TO BECOME STRONG TO POSSIBLY SEVER...WITH THE
PRIMARY HAZARD BEING QUARTER SIZE HAIL AND STRONG WIND GUSTS.
GARGAN
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
WATER VAPOR IMAGERY SHOWING ONE SHORTWAVE TROUGH OVER NE MOVING
SOUTHEAST WITH CONVECTION OUT AHEAD OF IT WITHIN WAA REGIME ACROSS
SOUTHERN NE INTO CENTRAL KS. THIS AREA OF CONVECTION WILL CONTINUE
TO MOVE EAST AND SOUTHEAST ACROSS THE CWA THROUGH SUNRISE BEFORE
DIMINISHING. A COLD FRONT OVER CENTRAL NE WILL MOVE SOUTHEAST ACROSS
THE CWA THROUGH THE MIDDAY/AFTERNOON HOURS. IF SUFFICIENT
HEATING/DESTABILIZATION IN THE WAKE OF THIS MORNINGS ACTIVITY
OCCURS...MUCAPES OF 1500-2000 J/KG ARE POSSIBLE ACROSS THE SOUTHEAST
CWA...PRIMARILY ALONG AND SOUTHEAST OF THE I 35 CORRIDOR AT THE TIME
OF THE FROPA. IF ANY ISOLATED TO SCATTERED CONVECTION IS ABLE TO
REDEVELOP ALONG/AHEAD OF THE FRONT WITHIN THIS ENVIRONMENT...THEY
MAY BECOME CAPABLE OF PRODUCING SOME HAIL TO QUARTER SIZE AND STRONG
GUSTY WINDS. THIS ACTIVITY WOULD LIKELY EXIT THE FAR SOUTHEAST CWA
BY EARLY EVENING...ALTHOUGH MORE POST FRONTAL SHOWERS COULD STILL
REDEVELOP FURTHER TOWARDS THE NORTHWEST IN ADVANCE OF THE SHORTWAVE
TROUGH CURRENTLY MOVING INTO WY. ANY SHOWERS ASSOCIATED WITH THIS
SHOULD DISSIPATE BY MIDNIGHT...LEAVING THE REMAINDER OF NIGHT DRY
AND COOLER.
SUNDAY STILL LOOKING DRY AND MILD WITH HIGHS GENERALLY 65 TO 70 IN
ADVANCE OF THE NEXT MUCH STRONGER COLD FRONT TO THE NORTH. THIS
FRONT WILL PASS THROUGH THE CWA NORTH TO SOUTH THROUGH THE EVENING
WITH A CHANCE FOR RAIN...THEN A CHANCE FOR RAIN OR SNOW OVERNIGHT
INTO MONDAY AS THE COLDER AIR PLUNGES SOUTHWARD. ANY SNOWFALL APPEAR
SHOULD PRIMARILY BE UNDER HALF AN INCH AT THIS TIME. THE WINTRY MIX
POTENTIAL WILL SHIFT TO THE SOUTHERN CWA THROUGH AFTERNOON THEN END
BY EVENING...BUT AGAIN AMOUNTS SHOULD BE VERY LIGHT. 63
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 955 AM CDT SAT MAR 30 2013*
ISSUED AT 955 AM CDT SAT MAR 30 2013
MODELS STILL KEEPING THE NEXT TROUGH IN THE ROCKIES TO THE SOUTH OF
THE AREA THROUGH MID WEEK WITH DRY CONDITIONS AND A GRADUAL
MODERATION IN TEMPS AS THE AREA GRADUALLY TRANSITIONS FROM NORTHWEST
FLOW ALOFT TO A MORE ZONAL FLOW. HIGHS SHOULD RISE FROM NEAR 40 ON
MONDAY TO THE 50S BY WEDNESDAY...THEN THE 60S AGAIN BY FRIDAY. LOWS
IN THE 20S EARLY IN THE WEEK SHOULD RISE TO NEAR 40 BY FRIDAY. 63
&&
.AVIATION...
LOW CIGS HAVE HAD A HARD TIME MOVING INTO THE TERMINALS AND THINK
THE MODELS CONTINUE TO BE TO COOL IN THE BOUNDARY LAYER AND
OVERDOING THE RH. OUTSIDE OF SOME LIGHT SHOWERS...THINK CONDITIONS
WILL TEND TO BE VFR. ONLY EXCEPTION WOULD BE IF WE CLEAR OUT. THEN
THERE COULD BE SOME RADIATIONAL FOG...BUT THINK THE CLOUDS WILL HANG
IN UNTIL AFTER SUNRISE. FROPA SHOULD OCCUR IN THE EARLY TO MID
AFTERNOON. SOME OF THE HIGH RES SOLUTIONS SHOW SOME WEAK POP UP
SHOWERS POSSIBLE UNTIL THE FRONT MOVES THROUGH. THE HRRR SEEMS TO BE
DOING THE BEST WITH THIS MORNINGS PRECIP AND TAKES MOST OF THE
ACTIVITY EAST OF TOP AND FOE BY 15Z. SO WILL KEEP A DRY FORECAST DUE
TO LOW CONFIDENCE IN LOCATION OF ANY ISOLATED SHOWER ACTIVITY THIS
AFTERNOON.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GARGAN
SHORT TERM...63
LONG TERM...63
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
617 AM CDT SAT MAR 30 2013
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
LOW CIGS HAVE HAD A HARD TIME MOVING INTO THE TERMINALS AND THINK
THE MODELS CONTINUE TO BE TO COOL IN THE BOUNDARY LAYER AND
OVERDOING THE RH. OUTSIDE OF SOME LIGHT SHOWERS...THINK CONDITIONS
WILL TEND TO BE VFR. ONLY EXCEPTION WOULD BE IF WE CLEAR OUT. THEN
THERE COULD BE SOME RADIATIONAL FOG...BUT THINK THE CLOUDS WILL HANG
IN UNTIL AFTER SUNRISE. FROPA SHOULD OCCUR IN THE EARLY TO MID
AFTERNOON. SOME OF THE HIGH RES SOLUTIONS SHOW SOME WEAK POP UP
SHOWERS POSSIBLE UNTIL THE FRONT MOVES THROUGH. THE HRRR SEEMS TO BE
DOING THE BEST WITH THIS MORNINGS PRECIP AND TAKES MOST OF THE
ACTIVITY EAST OF TOP AND FOE BY 15Z. SO WILL KEEP A DRY FORECAST DUE
TO LOW CONFIDENCE IN LOCATION OF ANY ISOLATED SHOWER ACTIVITY THIS
AFTERNOON.
WOLTERS
&&
.PREV DISCUSSION... /415 AM CDT SAT MAR 30 2013/
WATER VAPOR IMAGERY SHOWING ONE SHORTWAVE TROUGH OVER NE MOVING
SOUTHEAST WITH CONVECTION OUT AHEAD OF IT WITHIN WAA REGIME ACROSS
SOUTHERN NE INTO CENTRAL KS. THIS AREA OF CONVECTION WILL CONTINUE
TO MOVE EAST AND SOUTHEAST ACROSS THE CWA THROUGH SUNRISE BEFORE
DIMINISHING. A COLD FRONT OVER CENTRAL NE WILL MOVE SOUTHEAST ACROSS
THE CWA THROUGH THE MIDDAY/AFTERNOON HOURS. IF SUFFICIENT
HEATING/DESTABILIZATION IN THE WAKE OF THIS MORNINGS ACTIVITY
OCCURS...MUCAPES OF 1500-2000 J/KG ARE POSSIBLE ACROSS THE SOUTHEAST
CWA...PRIMARILY ALONG AND SOUTHEAST OF THE I 35 CORRIDOR AT THE TIME
OF THE FROPA. IF ANY ISOLATED TO SCATTERED CONVECTION IS ABLE TO
REDEVELOP ALONG/AHEAD OF THE FRONT WITHIN THIS ENVIRONMENT...THEY
MAY BECOME CAPABLE OF PRODUCING SOME HAIL TO QUARTER SIZE AND STRONG
GUSTY WINDS. THIS ACTIVITY WOULD LIKELY EXIT THE FAR SOUTHEAST CWA
BY EARLY EVENING...ALTHOUGH MORE POST FRONTAL SHOWERS COULD STILL
REDEVELOP FURTHER TOWARDS THE NORTHWEST IN ADVANCE OF THE SHORTWAVE
TROUGH CURRENTLY MOVING INTO WY. ANY SHOWERS ASSOCIATED WITH THIS
SHOULD DISSIPATE BY MIDNIGHT...LEAVING THE REMAINDER OF NIGHT DRY
AND COOLER.
SUNDAY STILL LOOKING DRY AND MILD WITH HIGHS GENERALLY 65 TO 70 IN
ADVANCE OF THE NEXT MUCH STRONGER COLD FRONT TO THE NORTH. THIS
FRONT WILL PASS THROUGH THE CWA NORTH TO SOUTH THROUGH THE EVENING
WITH A CHANCE FOR RAIN...THEN A CHANCE FOR RAIN OR SNOW OVERNIGHT
INTO MONDAY AS THE COLDER AIR PLUNGES SOUTHWARD. ANY SNOWFALL APPEAR
SHOULD PRIMARILY BE UNDER HALF AN INCH AT THIS TIME. THE WINTRY MIX
POTENTIAL WILL SHIFT TO THE SOUTHERN CWA THROUGH AFTERNOON THEN END
BY EVENING...BUT AGAIN AMOUNTS SHOULD BE VERY LIGHT.
MODELS STILL KEEPING THE NEXT TROUGH IN THE ROCKIES TO THE SOUTH OF
THE AREA THROUGH MID WEEK WITH DRY CONDITIONS AND A GRADUAL
MODERATION IN TEMPS AS THE AREA GRADUALLY TRANSITIONS FROM NORTHWEST
FLOW ALOFT TO A MORE ZONAL FLOW. HIGHS SHOULD RISE FROM NEAR 40 ON
MONDAY TO THE 50S BY WEDNESDAY...THEN THE 60S AGAIN BY FRIDAY. LOWS
IN THE 20S EARLY IN THE WEEK SHOULD RISE TO NEAR 40 BY FRIDAY. 63
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TULSA OK
1026 AM CDT SAT MAR 30 2013
.DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE ACROSS EAST CENTRAL OK
AND NORTHWEST AR THIS MORNING BUT CONTINUE TO DECREASE IN
INTENSITY AS THEY SHIFT SOUTHEAST. EXPECT THIS ROUND TO MOVE OUT
OF THE FORECAST AREA AROUND 19-20Z WITH ENOUGH BREAKS IN CLOUDS TO
SEND TEMPS WELL INTO 70S ACROSS MUCH OF EASTERN OK...AND REMAINING
A BIT COOLER IN FAR EASTERN AREAS. RE-DEVELOPMENT OF STORMS ALONG
ANY BOUNDARIES THIS AFTERNOON APPEARS QUESTIONABLE...THOUGH
CERTAINLY NOT A ZERO CHANCE IN UNSTABLE AND WEAKLY CAPPED
ENVIRONMENT. HAVE UPDATED POPS BASED ON RADAR TRENDS FOR THE
MORNING AND HAVE REDUCED THEM SOME FOR THE AFTERNOON ACROSS
WESTERN AREAS. ALSO KNOCKED A FEW DEGREES OFF FORECAST HIGHS IN
FAR NW ARKANSAS.
&&
.PREV DISCUSSION... /ISSUED 623 AM CDT SAT MAR 30 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VARIABLE SKY CONDITIONS WILL PERSIST THROUGH THE MORNING
HOURS...WITH AREAS OF MVFR/IFR CIGS MAINLY ACROSS SOUTHEAST
OK AND WEST CENTRAL AR. LOCALIZED LOWER CIGS/VSBYS WILL
OCCUR WITH SHOWERS/THUNDERSTORMS THROUGH THE MORNING HOURS.
SOME IMPROVEMENT IS EXPECTED INTO THE AFTERNOON...WITH
AREAS OF SHOWERS/THUNDERSTORMS DEVELOPING AGAIN BY LATE
AFTERNOON OR EARLY EVENING.
PREV DISCUSSION... /ISSUED 457 AM CDT SAT MAR 30 2013/
DISCUSSION...
WAVE TRAIN ROLLING ALONG IN NORTHWEST FLOW HAULING
CLUSTERS OF SHOWERS AND THUNDERSTORMS THIS MORNING.
SOME OF THE STRONGER THUNDERSTORMS PROVED EFFICIENT
HAIL PRODUCERS OVERNIGHT.
IN THE SHORT TERM FOLLOWED HRRR MODEL WHICH HAS BEEN
GOOD LAST SIX HOURS WITH CONVECTIVE ACTION. BULK OF
CURRENT PRECIP EAST OF NORTHWEST AR ZONES AROUND 18Z.
QUESTION THEN BECOMES WHAT BOUNDARIES ARE LEFT BEHIND
TO FIRE LATE AFTERNOON..OR EVENING. TEMPERATURES INTO
THE MID 70S THIS AFTERNOON..IN ADVANCE OF A WEAK COOL
FRONTAL BOUNDARY SAGGING INTO THE FORECAST AREA WILL
LIKELY IGNITE ANOTHER ROUND OF THUNDER. CAPE VALUES
IN THE 2000 J/KG NEIGHBORHOOD AND SUFFICIENT SHEAR
WILL BE CAPABLE OF LARGE HAIL PRODUCTION.
CONVECTION MIGRATING SOUTHEAST OVERNIGHT LEAVING MOST
AREAS NORTH OF INTERSTATE 40 WITH A DRY WARM EASTER.
SHOWERS THUNDER MOST LIKELY NEAR OR SOUTH OF THE RED
RIVER.
NEXT WAVE AND REAL COLD FRONT ARRIVE SOMETIME MONDAY.
WRF VERY FAST AND THE OUTLIER IN BRINGING IN THE COLD
AIR COMPARED TO MOST OF THE OTHER MODELS. RESULTING
WRF MOS BASED MAX TEMPS SOME 15 TO 20 DEGREES COLDER
FOR NORTHERN LOCATIONS. USED FOUR MODEL MAX TEMP.
MODEL DIFFERENCES CONTINUE TO PLAGUE THE MIDWEEK TIME
PERIOD. ECMWF CONSISTENT WITH ITSELF BRINGING AN UPPER
LOW DIRECTLY OVER FORECAST AREA. MEANWHILE GFS WEAKER
DRIER... MORE PROGRESSIVE WITH THE FEATURE. ECMWF TOO
GOOD TO TOTALLY IGNORE..CHANCE POPS MIDWEEK.
GW
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 77 51 73 43 / 90 60 10 10
FSM 73 56 74 48 / 70 60 30 10
MLC 75 55 73 48 / 70 60 30 10
BVO 76 46 72 40 / 40 50 10 10
FYV 67 51 70 42 / 100 70 20 0
BYV 65 49 69 41 / 90 70 10 0
MKO 75 54 72 46 / 60 60 20 10
MIO 71 47 71 42 / 90 60 0 10
F10 76 54 72 47 / 50 60 20 10
HHW 74 57 72 53 / 50 60 60 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...14
AREA FORECAST DISCUSSION
NWS TULSA OK
623 AM CDT SAT MAR 30 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VARIABLE SKY CONDITIONS WILL PERSIST THROUGH THE MORNING
HOURS...WITH AREAS OF MVFR/IFR CIGS MAINLY ACROSS SOUTHEAST
OK AND WEST CENTRAL AR. LOCALIZED LOWER CIGS/VSBYS WILL
OCCUR WITH SHOWERS/THUNDERSTORMS THROUGH THE MORNING HOURS.
SOME IMPROVEMENT IS EXPECTED INTO THE AFTERNOON...WITH
AREAS OF SHOWERS/THUNDERSTORMS DEVELOPING AGAIN BY LATE
AFTERNOON OR EARLY EVENING.
&&
.PREV DISCUSSION... /ISSUED 457 AM CDT SAT MAR 30 2013/
DISCUSSION...
WAVE TRAIN ROLLING ALONG IN NORTHWEST FLOW HAULING
CLUSTERS OF SHOWERS AND THUNDERSTORMS THIS MORNING.
SOME OF THE STRONGER THUNDERSTORMS PROVED EFFICIENT
HAIL PRODUCERS OVERNIGHT.
IN THE SHORT TERM FOLLOWED HRRR MODEL WHICH HAS BEEN
GOOD LAST SIX HOURS WITH CONVECTIVE ACTION. BULK OF
CURRENT PRECIP EAST OF NORTHWEST AR ZONES AROUND 18Z.
QUESTION THEN BECOMES WHAT BOUNDARIES ARE LEFT BEHIND
TO FIRE LATE AFTERNOON..OR EVENING. TEMPERATURES INTO
THE MID 70S THIS AFTERNOON..IN ADVANCE OF A WEAK COOL
FRONTAL BOUNDARY SAGGING INTO THE FORECAST AREA WILL
LIKELY IGNITE ANOTHER ROUND OF THUNDER. CAPE VALUES
IN THE 2000 J/KG NEIGHBORHOOD AND SUFFICIENT SHEAR
WILL BE CAPABLE OF LARGE HAIL PRODUCTION.
CONVECTION MIGRATING SOUTHEAST OVERNIGHT LEAVING MOST
AREAS NORTH OF INTERSTATE 40 WITH A DRY WARM EASTER.
SHOWERS THUNDER MOST LIKELY NEAR OR SOUTH OF THE RED
RIVER.
NEXT WAVE AND REAL COLD FRONT ARRIVE SOMETIME MONDAY.
WRF VERY FAST AND THE OUTLIER IN BRINGING IN THE COLD
AIR COMPARED TO MOST OF THE OTHER MODELS. RESULTING
WRF MOS BASED MAX TEMPS SOME 15 TO 20 DEGREES COLDER
FOR NORTHERN LOCATIONS. USED FOUR MODEL MAX TEMP.
MODEL DIFFERENCES CONTINUE TO PLAGUE THE MIDWEEK TIME
PERIOD. ECMWF CONSISTENT WITH ITSELF BRINGING AN UPPER
LOW DIRECTLY OVER FORECAST AREA. MEANWHILE GFS WEAKER
DRIER... MORE PROGRESSIVE WITH THE FEATURE. ECMWF TOO
GOOD TO TOTALLY IGNORE..CHANCE POPS MIDWEEK.
GW
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 77 51 73 43 / 50 60 10 10
FSM 73 56 74 48 / 80 60 30 10
MLC 75 55 73 48 / 50 60 30 10
BVO 76 46 72 40 / 40 50 10 10
FYV 69 51 70 42 / 90 70 20 0
BYV 67 49 69 41 / 90 70 10 0
MKO 75 54 72 46 / 60 60 20 10
MIO 71 47 71 42 / 70 60 0 10
F10 76 54 72 47 / 50 60 20 10
HHW 74 57 72 53 / 60 60 60 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...18
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
949 AM EDT SAT MAR 30 2013
.DISCUSSION...
LOW LEVEL MOISTURE APPEARS TO BE TRAPPED IN THE TN VALLEY. WITH
VERY WEAK FLOW FROM THE SURFACE TO 850 MB...THE CLOUDS WILL
PROBABLY BE SLOWER TO CLEAR THAN MODELS INDICATE. EXPECT THAT
CLEARING WILL NOT COME UNTIL AROUND 18Z OR LATER BASED ON THE
LATEST RUC SOUNDINGS. THIS WILL AFFECT TEMPS...SO THE UPDATE WILL
MAKE SOME DOWNWARD ADJUSTMENTS.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1008 AM EDT SAT MAR 30 2013
.SYNOPSIS...
HIGH PRESSURE ACROSS THE REGION WILL GRADUALLY SHIFT EAST AND
OFFSHORE THIS AFTERNOON INTO TONIGHT. THIS WILL RESULT IN MILDER
TEMPERATURES AHEAD OF A COLD FRONT THAT WILL BRING A CHANCE OF
RAIN SHOWERS LATER TONIGHT INTO SUNDAY. ANOTHER COLD FRONT SHOULD
PROVIDE A RETURN TO COLDER CONDITIONS DURING NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 943 AM EDT SATURDAY...
THIS MORNING 8AM/12Z RNK SOUNDING DISPLAYED AN INVERSION AROUND
910MB WITH A POCKET OF MOISTURE ABOUT 720 MB AND A WEST TO
NORTHWEST FLOW. HIGH PRESSURE OVER OHIO THIS MORNING WILL TRAVEL
EAST TODAY INTO TONIGHT. THIS WILL RESULT IN PLEASANT WEATHER THIS
AFTERNOON FOR OUR REGION WITH SEASONABLE TEMPERATURES. RNK WRFARW
AND HRRR SUPPORT THE MENTION OF ISOLATED SHOWERS ACROSS SOUTHWEST
PORTIONS OF CWA THIS AFTERNOON AND EVENING. THE MAIN AREA OF RAIN
ASSOCIATED WITH THE WARM FRONT ON TRACK TO DEVELOP OVERNIGHT.
MADE SOME MINOR MODIFICATIONS TO TEMPERATURES...CLOUD COVER AND
POPS FOR TODAY.
AS OF 252 AM EDT SATURDAY...
WARMING TREND CONTINUES OVER THE NEXT 24 HOURS AS HIGH PRESSURE
ACROSS THE REGION THIS MORNING GRADUALLY SHIFTS EAST AND OFFSHORE
ALLOWING A WEAK WARM ADVECTION PATTERN TO TAKE SHAPE. WILL HAVE A
WEAK IMPULSE PASSING TO THE SOUTH EARLY THIS MORNING BEFORE THE
AREA WORKS INTO A WEAK SUBSIDENCE REGION BETWEEN THE RIDGE AND A
WARM FRONT TO THE SW THIS AFTERNOON. THIS LOOKS TO HELP DIMINISH
CLOUDS IN ALL AREAS EXCEPT PERHAPS THE FAR SW WHERE SOME MOISTURE
MAY GET STUCK FROM THE NW NC RIDGES INTO SW VA. MAY ALSO LEAVE IN
THE GOING ISOLATED -RA MENTION IN NW NC EARLY BEFORE DEEPER
MOISTURE EXITS WITH MORE OF AN AC TO CU FIELD ELSW THIS AFTERNOON.
LATEST MODEL THICKNESS COMBO WITH WEAK SW FLOW AND BASED ON MORE
INSOLATION SUPPORTS HIGHS LOW/MID 60S BLUE RIDGE EAST TODAY...AND
MID/UPPER 50S WEST OUTSIDE OF THE HIGHER ELEVATIONS.
WARM FRONT AND ASSOCIATED WEAK VORT AXIS WILL APPROACH FROM THE
SW OVERNIGHT HELPING TURN THE LOW LEVEL FLOW MORE SE THIS EVENING
AHEAD OF THE MAIN BODY OF DEEPER MOISTURE/SHRA THAT WILL BE
NEARING THE WEST SHORTLY AFTER MIDNIGHT. MODELS REMAIN RATHER
CONSISTENT IN SHOWING A SWATH OF BETTER LIFT ACROSS THE NW CLOSER
TO THE MAIN SHORTWAVE AXIS...AND ALONG THE SRN BLUE RIDGE WHERE
AIDED BY WEAK UPSLOPE AND PERHAPS A SECONDARY BAGGY WAVE ALONG THE
WARM FRONT LATE. THIS INITIAL UPSLOPE FLOW SUPPORTS GOING A BIT
FASTER WITH POPS OVERNIGHT WITH ALL EXCEPT THE EASTERN THIRD
SEEING LIKELY/CAT POPS BY DAYBREAK. CANT TOTALLY RULE OUT A RUMBLE
OF THUNDER ESPCLY SW GIVEN DECENT LIFT AND PUNCH OF WARM AIR
COMING IN WITH AN INCREASING 85H JET LIKELY WITH WHATS LEFT OF AN
EARLIER MCS. HOWEVER GIVEN FCST LOW LEVEL STABILITY WONT INCLUDE
FOR NOW. HEAVIEST QPF THRU DAWN LOOKS TO BE OVER THE FAR WEST WITH
AROUND A QUARTER TO ONE HALF INCH POSSIBLE ESPCLY WHERE ENHANCED
BY WEAK UPSLOPE AND SOME EMBEDDED CONVECTION ALOFT. LOW TEMPS
SHOULD BE MUCH MILDER THAN SEEN IN A WHILE WITH UPPER 30S TO MID
40S...WITH PERHAPS A FEW VALLEYS AND EASTERN SPOTS A BIT COLDER
EARLY ON BEFORE RISING LATE AS CLOUDS/SHRA ARRIVE.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 315 AM EDT SATURDAY...
A WARM FRONT WILL SPREAD A QUICK SHOT OF RAIN ACROSS THE REGION
DURING THE FIRST HALF OF SUNDAY. THE COLD FRONT HOLDS TO THE NW LONG
ENOUGH SO THAT MONDAY WILL FEATURE MANY HIGHS IN THE 60S WITH H85
TEMPS FROM +4C TO +8C. ALTHOUGH ITS BEEN SAID WAY TOO MANY TIMES
THIS MARCH...THE COLD SHOT ARRIVING MONDAY NIGHT THROUGH TUESDAY MAY
BE WINTER`S LAST GASP...WITH -10C AT H85 ONCE AGAIN TOUCHING SE WEST
VA. ALTHOUGH THE OP GFS IS GENERATING LIGHT SNOW ACROSS MOSTLY
GREENBRIER MONDAY NIGHT...ALL OTHER MODELS SAY NO...AND ARE MUCH
DRIER AT H85 AND H7.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 115 PM EDT FRIDAY...
COLDER AIR PUSHING IN WITH STRONG CANADIAN HIGH MOVING SE INTO
THE PLAINS. THIS HIGH MOVES INTO THE OHIO VALLEY BY WEDNESDAY AND
SHIFTS EAST OF US THURSDAY. TEMPS WILL AGAIN BE FALLING WELL BELOW
NORMAL WITH HIGHS TUE-WED IN THE UPPER 30S TO MID 40S MTNS...AND
MID 40S TO LOWER 50S EAST.
FOR THE THU NIGHT-FRI TIME FRAME...THE 00Z ECMWF SHOWS THE NEXT
SHORTWAVE PUSHING INTO THE OHIO VALLEY SOUTH TO THE GULF COAST.
MEANWHILE...THE 12Z GFS IS FASTER AND FURTHER SOUTH WITH ITS SYSTEM
KEEPING PRECIP MORE OVER THE SOUTHEAST. THE ECMWF WORKS A WARM FRONT
AND LOW NE TO THE AREA FRIDAY WITH RAIN...AND RETREATING HIGH
PRESSURE. LEANED THE FORECAST TOWARD A WETTER SOLUTION SIMILAR TO
THE ECMWF. SHOULD BE MAINLY RAIN BUT CANNOT RULE OUT SOME WINTRY
PRECIP IF THE COLD AIR IS SLOW TO DISLODGE.
BOTH MODELS AFTER FRIDAY CLOSE OFF AN UPPER LOW ALONG THE EAST
COAST...DELMARVA AREA FOR ECMWF AND EAST OF SOUTH CAROLINA FOR THE
GFS.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 AM EDT SATURDAY...
AN UPPER LEVEL DISTURBANCE WILL CONTINUE TO TRACK SE OF THE AREA
THIS MORNING ALLOWING A REDUCTION IN COVERAGE OF LOW/MID CLOUDS
THROUGH MIDDAY. APPEARS ANY LEFTOVER MID DECK OR STRATO-CU LAYER
ALONG WITH PATCHY FOG WILL QUICKLY MIX OUT THIS MORNING PER
HEATING TO MORE SCTD/BKN VFR LEVEL CU BY AFTERNOON. THUS EXPECT
GOOD FLYING CONDITIONS TO PREVAIL IN MOST AREAS INTO/THROUGH EARLY
THIS EVENING BEFORE THE APPROACH OF A WARM FRONT BRINGS AN
INCREASING THREAT OF SHOWERS ALONG WITH FLIGHT RESTRICTIONS BACK
INTO MVFR OR IFR RANGE LATER TONIGHT INTO MUCH OF SUNDAY. LOOKS
LIKE MOST OF THE RAINFALL WILL AFFECT THE WESTERN TAF LOCATIONS
SUCH AS KBLF/KBCB SHORTLY AFTER MIDNIGHT...AND THEN PROGRESS
NORTH/EAST OVER THE REMAINDER OF THE FORECAST POINTS BY DAYBREAK.
COULD SEE CIGS/VSBYS RAPIDLY LOWER AS WELL AROUND DAWN ON SUNDAY
AS A PERIOD OF MODERATE TO HEAVY RAIN TRACKS ACROSS PARTS OF THE
AREA AS WELL.
PASSAGE OF THE WARM FRONT EARLY AND SUBSEQUENT COLD FRONT LATER IN
THE DAY SHOULD BRING END TO RAIN THREAT ALONG WITH CLEARING SKIES
IN DOWNSLOPING AREAS EAST OF THE BLUE RIDGE BY LATE SUNDAY
AFTERNOON. HOWEVER TYPICAL UPSLOPING CLOUDS..AND POSSIBLY SOME
ISOLATED SHOWERS SHOULD MAINTAIN A THREAT FOR AT LEAST OCCASIONAL
MVFR CEILINGS THROUGH SUNDAY NIGHT ACROSS SOUTHEASTERN WV TERMINAL
FORECAST POINTS.
APPROACH OF MUCH MORE POTENT COLD FRONT WILL MAINTAIN MVFR TO
POSSIBLY IFR RESTRICTIONS WITH INCREASING THREAT OF PRECIPITATION
ACROSS UPSLOPE AREAS OF THE WEST LATER MONDAY INTO MONDAY
NIGHT. EXPECT VFR CONDITIONS EAST OF THE BLUE RIDGE TO BE OVERTAKEN
BY AT LEAST MVFR RESTRICTIONS MONDAY NIGHT INTO TUESDAY MORNING AS
COLD FRONT AND ASSOCIATED PRECIPITATION MOVE EAST THROUGH THE
AREA.
PROLONGED PERIOD OF COLD UPSLOPING WINDS AND SNOW SHOWERS WILL
AGAIN MAINTAIN MVFR TO OCCASIONAL IFR RESTRICTIONS TO WESTERN
FLANKS OF THE APPALACHIANS TUESDAY THROUGH WEDNESDAY...BUT WITH A
RETURN TO VFR WEATHER EXPECTED IN DOWNSLOPING AREAS EAST OF THE
BLUE RIDGE FOLLOWING FRONTAL PASSAGE TUESDAY AFTERNOON CONTINUING
INTO WEDNESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/WP
NEAR TERM...JH/KK
SHORT TERM...KM
LONG TERM...WP
AVIATION...JH/WERT
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1215 PM PDT SAT MAR 30 2013
UPDATED CLIMATE SECTION
.DISCUSSION...AS OF 8:29 AM PDT SATURDAY...IR SATELLITE AND KMUX
PRETTY MUCH SAY IT ALL...A STORM SYSTEM IS APPROACHING THE BAY
AREA WITH A MIXTURE OF CLOUDS AND SHOWERS. AS MENTIONED ON THE
PREVIOUS DISCUSSION...MUCH OF THE SHORT TERM WEATHER CONCERNS WILL
BE ASSOCIATED WITH A SFC LOW NEAR 34N/132W. KMUX RADAR IMAGERY
CONTINUES TO INDICATE SHOWER ACTIVITY OFF THE NORTH BAY COAST AND
PARTS OF THE NORTH BAY. HOWEVER...THESE SHOWERS ARE BEING DETECTED AT
ROUGHLY 10-12K FEET AGL. THE MORNING KOAK SOUNDING SHOWS A MOIST
LAYER AROUND 10K FEET...BUT A LARGE DRY POCKET OF AIR JUST BELOW
10K FEET. THE ECHOES DETECTED ON RADAR ARE PROBABLY NOT REACHING
THE GROUND. THIS IS FURTHER CONFIRMED BY THE LACK OF SFC REPORTS
FOR MEASURABLE PRECIP. THAT BEING SAID...PATCHY STRATUS DOES EXIST
ALONG THE COAST WITH LIGHT DRIZZLE BEING REPORTED. ALSO...DURING
THE MORNING HOURS A FEW SPRINKLES MAY BE POSSIBLE WITH THE RADAR
ECHOES...BUT WIDESPREAD SHOWERS SEEMS UNLIKELY.
NO UPDATE PLANNED AT THIS TIME. WILL CONTINUE TO MONITOR
DEVELOPING SHOWERS AND APPROACHING STORM SYSTEM. THERE WILL BE A
BETTER CHANCE FOR SHOWERS LATE THIS AFTERNOON AND EVENING AS THE
PARENT SFC LOW MOVES CLOSER TO THE COAST. IN FACT...SOME OF THE
12Z MODEL GUIDANCE...INCLUDING THE RAP AND HRRR...KEEP THE BULK OF
THE MOISTURE OFF THE COAST UNTIL AFTER 00Z SUNDAY. THE OTHER
INTERESTING ITEM OF NOTE...THE NAM12 FCST SOUNDINGS STILL DEVELOP
CONVECTION OVER THE NORTH BAY THIS AFTERNOON...CAPE 500 J/KG WITH
LITTLE CIN AND LI/S MINUS 3. NOT TOTALLY BUYING OFF ON THIS YET
GIVEN THE CLOUD COVER/WEAK MARINE LAYER AND LACK OF SOLAR HEATING
EXPECTED. BETTER CHANCE FOR CONVECTION ON SUNDAY AS THE UPPER LOW
AND COLD AIR ALOFT PASS OVERHEAD.
THE BULK OF THE RAIN STILL LOOKS TO OCCUR DURING THE OVERNIGHT
HOURS TONIGHT AND SUNDAY. HIGH PRESSURE BUILDS OVER THE REGION ON
MONDAY AND ANY LINGERING SHOWERS WILL DIMINISH. NAILING DOWN
PRECIP AMOUNTS IS SOMEWHAT PROBLEMATIC GIVEN THE CONVECTIVE NATURE
OF PRECIP TONIGHT THROUGH EARLY MONDAY. FOR NOW...BEST GUESS
CONTINUES INDICATE A FEW TENTHS OVER THE LOWER ELEVATIONS AND UP
TO ONE INCH OVER THE COASTAL MOUNTAINS.
PREVIOUS...THE NEXT RAIN CHANCES WILL OCCUR WEDNESDAY NIGHT AND
THURSDAY AS AN UPPER TROUGH MOVES ONTO THE COAST...WITH ANOTHER
SYSTEM POSSIBLE BY NEXT WEEKEND.
&&
.AVIATION...AS OF 11:45 AM PDT SATURDAY...FOR 18Z TAFS. SOUTHERLY
FLOW ASSOCIATED WITH UPPER LOW IS KEEPING STUBBORN LOW CLOUDS
AROUND THE REGION ALONG WITH MID AND HIGH DECKS. AIRPORT LEAST
IMPACTED CONTINUES TO BE SAN JOSE WHILE MVFR CLOUD DECKS CONTINUE
TO COME IN AND OUT OF KSFO AND KOAK WITH SHOWERS AND IFR
CONDITIONS IN THE NORTH BAY. IN GENERAL LOOK FOR LIFTING CLOUD
DECKS THIS AFTERNOON AND EVENING AS THE AREA WILL BE IN A LULL
REGION BEFORE THE NEXT SPOKE OF ENERGY ROTATES ONSHORE AFTER 06Z.
VICINITY OF KSFO...MVFR CONDITIONS CONTINUE THROUGH 21Z BUT WITH
CIG HEIGHTS CONTINUING TO LIFT THROUGH THE LATE AFTERNOON AND
EVENING HOURS. NEXT BAND OF SHOWERS LOOKS TO HOLD OFF UNTIL
SOMETIME AROUND MIDNIGHT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO BUT WITH LESS LOW CLOUDS
EXPECTED SOUTH OF THE BRIDGE AND TOWARDS KSJC THIS AFTERNOON AND EVENING.
MONTEREY BAY AREA TERMINALS...STUBBORN CIGS CONTINUE TO IMPACT
KMRY AND KSNS BUT WITH CLEAR SKIES JUST WEST OF KMRY AND OVER THE
OCEAN EXPECTED TO DEVELOP BY LATER THIS AFTERNOON. -SHRA EXPECTED
TO DEVELOP LATER THIS EVENING NEAR KMRY IN SW FLOW AHEAD OF NEXT
UPPER DISTURBANCE.
&&
.CLIMATE...DOWNTOWN SAN FRANCISCO IS ON TRACK TO HAVE ITS DRIEST
JANUARY THROUGH MARCH ON RECORD. THE CITY HAS A CONTINUAL DATA SET
GOING BACK TO 1850, SO IT IS NOTABLE WHEN RECORDS ARE BROKEN
THERE. AS OF NOON TODAY, ONLY 1.73" OF RAIN HAS BEEN RECORDED.
THIS AMOUNT IS NEARLY 1.5" BELOW THE CURRENT JANUARY THROUGH MARCH
RECORD OF 3.20" SET ALL OF THE WAY BACK IN 1850. THE AVERAGE
RAINFALL FOR THE SAME TIME PERIOD IS 12.22". WE WILL PROVIDE
UPDATED NUMBERS AS RAIN FALLS IN SAN FRANCISCO THIS WEEKEND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: MM
AVIATION/MARINE: RWW
CLIMATE: BELL
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1145 AM PDT SAT MAR 30 2013
.DISCUSSION...AS OF 8:29 AM PDT SATURDAY...IR SATELLITE AND KMUX
PRETTY MUCH SAY IT ALL...A STORM SYSTEM IS APPROACHING THE BAY
AREA WITH A MIXTURE OF CLOUDS AND SHOWERS. AS MENTIONED ON THE
PREVIOUS DISCUSSION...MUCH OF THE SHORT TERM WEATHER CONCERNS WILL
BE ASSOCIATED WITH A SFC LOW NEAR 34N/132W. KMUX RADAR IMAGERY
CONTINUES TO INDICATE SHOWER ACTIVITY OFF THE NORTH BAY COAST AND
PARTS OF THE NORTH BAY. HOWEVER...THESE SHOWERS ARE BEING DETECTED AT
ROUGHLY 10-12K FEET AGL. THE MORNING KOAK SOUNDING SHOWS A MOIST
LAYER AROUND 10K FEET...BUT A LARGE DRY POCKET OF AIR JUST BELOW
10K FEET. THE ECHOES DETECTED ON RADAR ARE PROBABLY NOT REACHING
THE GROUND. THIS IS FURTHER CONFIRMED BY THE LACK OF SFC REPORTS
FOR MEASURABLE PRECIP. THAT BEING SAID...PATCHY STRATUS DOES EXIST
ALONG THE COAST WITH LIGHT DRIZZLE BEING REPORTED. ALSO...DURING
THE MORNING HOURS A FEW SPRINKLES MAY BE POSSIBLE WITH THE RADAR
ECHOES...BUT WIDESPREAD SHOWERS SEEMS UNLIKELY.
NO UPDATE PLANNED AT THIS TIME. WILL CONTINUE TO MONITOR
DEVELOPING SHOWERS AND APPROACHING STORM SYSTEM. THERE WILL BE A
BETTER CHANCE FOR SHOWERS LATE THIS AFTERNOON AND EVENING AS THE
PARENT SFC LOW MOVES CLOSER TO THE COAST. IN FACT...SOME OF THE
12Z MODEL GUIDANCE...INCLUDING THE RAP AND HRRR...KEEP THE BULK OF
THE MOISTURE OFF THE COAST UNTIL AFTER 00Z SUNDAY. THE OTHER
INTERESTING ITEM OF NOTE...THE NAM12 FCST SOUNDINGS STILL DEVELOP
CONVECTION OVER THE NORTH BAY THIS AFTERNOON...CAPE 500 J/KG WITH
LITTLE CIN AND LI/S MINUS 3. NOT TOTALLY BUYING OFF ON THIS YET
GIVEN THE CLOUD COVER/WEAK MARINE LAYER AND LACK OF SOLAR HEATING
EXPECTED. BETTER CHANCE FOR CONVECTION ON SUNDAY AS THE UPPER LOW
AND COLD AIR ALOFT PASS OVERHEAD.
THE BULK OF THE RAIN STILL LOOKS TO OCCUR DURING THE OVERNIGHT
HOURS TONIGHT AND SUNDAY. HIGH PRESSURE BUILDS OVER THE REGION ON
MONDAY AND ANY LINGERING SHOWERS WILL DIMINISH. NAILING DOWN
PRECIP AMOUNTS IS SOMEWHAT PROBLEMATIC GIVEN THE CONVECTIVE NATURE
OF PRECIP TONIGHT THROUGH EARLY MONDAY. FOR NOW...BEST GUESS
CONTINUES INDICATE A FEW TENTHS OVER THE LOWER ELEVATIONS AND UP
TO ONE INCH OVER THE COASTAL MOUNTAINS.
PREVIOUS...THE NEXT RAIN CHANCES WILL OCCUR WEDNESDAY NIGHT AND
THURSDAY AS AN UPPER TROUGH MOVES ONTO THE COAST...WITH ANOTHER
SYSTEM POSSIBLE BY NEXT WEEKEND.
&&
.AVIATION...AS OF 11:45 AM PDT SATURDAY...FOR 18Z TAFS. SOUTHERLY
FLOW ASSOCIATED WITH UPPER LOW IS KEEPING STUBBORN LOW CLOUDS
AROUND THE REGION ALONG WITH MID AND HIGH DECKS. AIRPORT LEAST
IMPACTED CONTINUES TO BE SAN JOSE WHILE MVFR CLOUD DECKS CONTINUE
TO COME IN AND OUT OF KSFO AND KOAK WITH SHOWERS AND IFR
CONDITIONS IN THE NORTH BAY. IN GENERAL LOOK FOR LIFTING CLOUD
DECKS THIS AFTERNOON AND EVENING AS THE AREA WILL BE IN A LULL
REGION BEFORE THE NEXT SPOKE OF ENERGY ROTATES ONSHORE AFTER 06Z.
VICINITY OF KSFO...MVFR CONDITIONS CONTINUE THROUGH 21Z BUT WITH
CIG HEIGHTS CONTINUING TO LIFT THROUGH THE LATE AFTERNOON AND
EVENING HOURS. NEXT BAND OF SHOWERS LOOKS TO HOLD OFF UNTIL
SOMETIME AROUND MIDNIGHT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO BUT WITH LESS LOW CLOUDS
EXPECTED SOUTH OF THE BRIDGE AND TOWARDS KSJC THIS AFTERNOON AND EVENING.
MONTEREY BAY AREA TERMINALS...STUBBORN CIGS CONTINUE TO IMPACT
KMRY AND KSNS BUT WITH CLEAR SKIES JUST WEST OF KMRY AND OVER THE
OCEAN EXPECTED TO DEVELOP BY LATER THIS AFTERNOON. -SHRA EXPECTED
TO DEVELOP LATER THIS EVENING NEAR KMRY IN SW FLOW AHEAD OF NEXT
UPPER DISTURBANCE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: MM
AVIATION/MARINE: RWW
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
404 PM CDT SAT MAR 30 2013
...UPDATED SHORT TERM AND LONG TERM SECTIONS...
.SYNOPSIS...
ISSUED AT 215 PM CDT SAT MAR 30 2013
THE LONGWAVE PATTERN WAS CHARACTERIZED BY NORTHWEST FLOW FROM
WESTERN CANADA INTO THE CENTRAL CONUS. SEVERAL SHORTWAVE TROUGHS
EMBEDDED IN THE NORTHWEST FLOW PATTERN COULD BE IDENTIFIED ON WATER
VAPOR LOOP AND RAP ANALYSIS. THE DISTURBANCE WHICH LED TO LAST
NIGHT`S SEVERE WEATHER EVENT WAS LOCATED OVER MISSOURI AND ARKANSAS
EARLY THIS AFTERNOON. FARTHER UPSTREAM...ANOTHER SHORTWAVE TROUGH
WAS EVIDENT FROM WYOMING TO SOUTH DAKOTA. MEANWHILE...A FAIRLY LARGE
UPPER LOW WAS CENTERED OFF THE COAST OF CALIFORNIA DISCONNECTED FROM
THE POLAR JET STREAM FLOW. A SUBTROPICAL JET CONTAINED A FAIR AMOUNT
OF HIGH LEVEL CIRRUS IN THE LOW LATITUDES SOUTH OF THE
AFOREMENTIONED UPPER LOW INTO WESTERN MEXICO. AT THE SURFACE...A
WEAK TROUGH AXIS EXTENDED FROM NORTHEAST KANSAS INTO WESTERN
OKLAHOMA. THE NORTH TO NORTHWEST WINDS BEHIND THE TROUGH AXIS HAD
LOWER MOISTURE CONTENT WITH DEWPOINTS IN THE UPPER 30S TO LOWER 40S.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 403 PM CDT SAT MAR 30 2013
THE SHORTWAVE TROUGH MOVING SOUTHEAST ACROSS WESTERN NEBRASKA WILL
AID IN THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS LATE THIS AFTERNOON ACROSS SOUTHWEST NEBRASKA AND
NORTHEAST COLORADO. THE AIRMASS IN THIS REGION IS DRY WITH DEWPOINT
TEMPERATURES ONLY IN THE LOWER TO MID 30S. STEEP LAPSE RATES WERE
FOUND AHEAD OF THIS SHORTWAVE TROUGH AS SURFACE TEMPERATURES WARM
INTO THE LOWER TO MID 60S...AND MID LEVEL TEMPERATURES WERE COLD
(-20 TO -22C AT 500MB, 0 TO -4C AT 700MB). THIS THERMODYNAMIC
SETTING RESULTED IN A LITTLE BIT OF CONVECTIVE INSTABILITY WITH
SBCAPE AROUND A COUPLE HUNDRED J/KG. THERE WILL BE LOOSELY ORGANIZED
SHOWERS AND EMBEDDED THUNDER MOVING SOUTHEAST FROM THE CO/NE/KS
TRI-BORDER REGION TO WESTERN/CENTRAL KANSAS LATE TONIGHT. MID LEVEL
COLD ADVECTION AND DEEP TROPOSPHERIC ASCENT AHEAD OF THE WAVE WILL
AID IN SUSTAINING SHOWER AND THUNDER ACTIVITY THROUGH THE NIGHT.
AREAS CLOSER TO CENTRAL KANSAS (I.E. ELLIS COUNTY) WILL STAND A
BETTER CHANCE AT MORE ORGANIZED CONVECTION AS REMNANT LOW LEVEL
MOISTURE WAS HANGING AROUND AFTER THE TROUGH PASSAGE FROM EARLIER
TODAY. POPS WERE RAISED TO 40 TO 50 PERCENT...ESPECIALLY IN THE
NORTHEASTERN DDC FORECAST AREA (CLOSER TO CENTRAL KANSAS).
SUBSIDENCE IN THE WAKE OF THE SHORTWAVE TROUGH WILL MOVE INTO WEST
CENTRAL KANSAS DURING THE 09-12Z TIME FRAME...AND THE SHOWER
ACTIVITY WILL MOVE INTO SOUTH CENTRAL KANSAS AND NORTHERN OKLAHOMA.
AS FAR AS TEMPERATURES GO...COLD ADVECTION WILL BE RATHER WEAK AT
THE SURFACE WITH SOME DOWNSLOPE MODIFICATION...SO LOWS TONIGHT AFTER
THE SHOWERS MOVE THROUGH WILL ONLY BOTTOM OUT IN THE UPPER 30S TO
LOWER 40S. ON SUNDAY...SUBSIDENCE WILL PREVAIL WITH WEAK SURFACE
HIGH YIELDING LIGHT WINDS THROUGH THE DAY. HIGHS WERE LOWERED JUST
A COUPLE DEGREES INTO THE UPPER 60S GIVEN THE SLIGHTLY COOLER LOWER
TROPOSPHERE BEHIND THE WAVE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 403 PM CDT SAT MAR 30 2013
A COLD CANADIAN HIGH PRESSURE WILL AGAIN INFLUENCE THE WEATHER FOR
AT LEAST THE MONDAY THROUGH WEDNESDAY TIMEFRAME. BOTH THE GFS AND
ECMWF ALLOW A SURFACE BACKDOOR COLD FRONT TO SLIDE INTO WESTERN
KANSAS SUNDAY NIGHT INTO EARLY MONDAY, BRINGING EASTERLY UPSLOPE
WINDS THAT REMAIN ESTABLISHED THROUGH ABOUT WEDNESDAY MORNING.
ADDITIONALLY, THE MODELS HAVE BEEN VERY CONSISTENT NOW FOR SEVERAL
DAYS IN DEVELOPING A PROGRESSIVE TROUGH OVER THE WESTERN UNITED
STATES WHICH DIGS INTO THE SOUTHERN ROCKIES BY TUESDAY AND TUESDAY
NIGHT. THE RESULT WILL BE AN INCREASING CHANCE OF PRECIPITATION
(EITHER RAIN/SNOW OR BOTH) FROM THE LATE MONDAY TIMEFRAME THROUGH
TUESDAY AND WEDNESDAY MORNING. WITH THE COOL AND EASTERLY UPSLOPE
EXPECTED BY MONDAY, TEMPERATURES WILL DROP 20 TO 30 DEGREES FROM
SUNDAY AFTERNOON`S LOW 70`S. STRATUS WILL LIKELY IMPEDE INSOLATION
SIGNIFICANTLY DURING THE TIMEFRAME BASED ON MODEL 925-850 MB
RELATIVE HUMIDITY FIELDS. THROUGH THE DAY THE LAYER BECOME THICKER
WITH TIME, WHICH MIGHT SUGGEST SOME LIGHT FOG OR EVEN DRIZZLE
POTENTIAL THROUGH THE OVERNIGHT SUNDAY WITH TEMPERATURES REMAINING
ABOVE FREEZING. SNOW PRECIPITATION TYPE REALLY WON`T BE DEPENDENT ON
THE ARRIVAL OF COLD ENOUGH AIR ALOFT, BUT RATHER THE MOISTENING UP OF A
DEEP ENOUGH SATURATED LAYER THROUGH THE QG-FRONTOGENESIS/ISENTROPIC
LIFTING PROCESS ON TUESDAY.
THE LATEST ECMWF MODEL RUN DEPICT THE HEAVIER SNOWFALL TO OCCUR
FARTHER SOUTHWEST OVER SOUTHEAST COLORADO AND THE PANHANDLES, THAN
THE GFS MODEL RUNS WHICH FORECASTS HEAVY SNOW ACROSS SOUTHWEST
KANSAS. AT A MINIMUM THE MODEL TRENDS LEND CONFIDENCE TO HIGHER
CHANCES FOR PRECIPITATION DURING THIS TIMEFRAME, AND INFLUENCING
COOLER TEMPERATURES FOR WEDNESDAY. THE REMAINDER OF THE WEEK SHOULD
BRING A WARMING TREND BACK TOWARD CLIMATOLOGY AS UPPER LEVEL RIDGING
TO FLAT ZONAL UPPER LEVEL FLOW AND SOUTHERLY SURFACE WINDS BECOME
RE-ESTABLISHED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 215 PM CDT SAT MAR 30 2013
SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE SOUTHEAST ACROSS
WESTERN KANSAS DURING THE LATE EVENING HOURS. A COLD FRONT WILL MOVE
SOUTH TIED TO A SHORTWAVE TROUGH MOVING SOUTHEAST OUT OF NEBRASKA.
BEHIND THE FRONT...CEILINGS WILL DEVELOP IN THE MVFR RANGE AND WILL
FORECAST 1500 TO 2500 CEILING IN THE 09-15Z TIME FRAME. THERE WILL
BE A 2 OR 3 HOUR PERIOD OF FAIRLY STRONG NORTH TO NORTHWEST WINDS
IMMEDIATELY BEHIND THE FRONT OF 20 TO 25 KNOTS WITH SOME GUSTS ABOVE
30 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 40 68 35 45 / 40 10 40 40
GCK 38 68 35 44 / 40 10 30 40
EHA 41 68 40 44 / 30 10 30 40
LBL 41 68 42 45 / 30 10 30 40
HYS 38 67 34 44 / 50 10 40 40
P28 47 69 40 46 / 40 10 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...RUSSELL
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
216 PM CDT SAT MAR 30 2013
...UPDATED AVIATION AND SYNOPSIS SECTIONS...
.SYNOPSIS...
ISSUED AT 215 PM CDT SAT MAR 30 2013
THE LONGWAVE PATTERN WAS CHARACTERIZED BY NORTHWEST FLOW FROM
WESTERN CANADA INTO THE CENTRAL CONUS. SEVERAL SHORTWAVE TROUGHS
EMBEDDED IN THE NORTHWEST FLOW PATTERN COULD BE IDENTIFIED ON WATER
VAPOR LOOP AND RAP ANALYSIS. THE DISTURBANCE WHICH LED TO LAST
NIGHT`S SEVERE WEATHER EVENT WAS LOCATED OVER MISSOURI AND ARKANSAS
EARLY THIS AFTERNOON. FARTHER UPSTREAM...ANOTHER SHORTWAVE TROUGH
WAS EVIDENT FROM WYOMING TO SOUTH DAKOTA. MEANWHILE...A FAIRLY LARGE
UPPER LOW WAS CENTERED OFF THE COAST OF CALIFORNIA DISCONNECTED FROM
THE POLAR JET STREAM FLOW. A SUBTROPICAL JET CONTAINED A FAIR AMOUNT
OF HIGH LEVEL CIRRUS IN THE LOW LATITUDES SOUTH OF THE
AFOREMENTIONED UPPER LOW INTO WESTERN MEXICO. AT THE SURFACE...A
WEAK TROUGH AXIS EXTENDED FROM NORTHEAST KANSAS INTO WESTERN
OKLAHOMA. THE NORTH TO NORTHWEST WINDS BEHIND THE TROUGH AXIS HAD
LOWER MOISTURE CONTENT WITH DEWPOINTS IN THE UPPER 30S TO LOWER 40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 234 AM CDT SAT MAR 30 2013
TODAY:
NORTHWESTERLY FLOW ALOFT AND AN EMBEDDED SHORTWAVE TROF WILL MOVE ACROSS
THE NORTHERN PRAIRIES AND ACROSS THE CENTRAL PLAINS TODAY. THIS UL FEATURE
WILL USHER IN THE PASSAGE FOR A COLD FRONT WITH MUCH DRIER AIR ADVECTING
IN ACROSS THE REGION. NNW WINDS WILL STILL BE DOWNSLOPE AND A WARM 850
HPA PLUME WILL ADVECT ACROSS THE REGION, SO TEMPERATURES ARE EXPECTED
TO BE WARM. FORECASTING HIGHS IN THE MID TO UPPER 70S DEG F, WHICH IS
IN LINE WITH MOS GUIDANCE.
TONIGHT:
AN AREA OF ENHANCED 800-600 HPA FRONTOGENESIS WILL MOVE ACROSS THE REGION
AND COULD RESULT IN A FEW SHOWERS TONIGHT. EVEN THOUGH 500 HPA TEMPERATURES
ARE FAIRLY COLD /-20 DEG C/ NOT EXPECTING MUCH INSTABILITY AS THE DRY
AIR ADVECTS IN AND THE HIGHER THETA-E AXIS MOVES EAST OF THE REGION.
OVERNIGHT LOWS INTO SUNDAY WILL BE COOLER WITH THE DRIER AIRMASS - 30S
AND 40S DEG F.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT MAR 30 2013
A STRONG COLD FRONT IS STILL ADVERTISED TO PUSH SOUTH ACROSS THE
CENTRAL HIGH PLAINS LATE SUNDAY NIGHT INTO EARLY MONDAY. THE MEDIUM
RANGE MODELS ARE FOR THE MOST PART CONTINUING TO TREND TOWARD A
LESSENING IMPACT OF COLD AIR BEHIND THE FRONT. THE CANADIAN AND
ECMWF KEEP 850 MB TEMPERATURES ABOVE 0C ON MONDAY WHILE THE GFS IS
THE COLDEST WITH BELOW 0C TEMPERATURES SPREADING SOUTH THROUGH
NEARLY ALL OF SOUTHWEST KANSAS. HOWEVER, EVEN THIS MODEL IS NOT AS
COLD AS IT WAS A FEW DAYS AGO. HAVE BACKED OFF A BIT ON THE MENTION
OF SNOW FOR MONDAY...KEEPING IT CONFINED TO THE AREA ALONG AND NORTH
OF HIGHWAY 96 DURING THE DAY. WILL KEEP SOME SLIGHT CHANCES FOR RAIN
OR SNOW GOING MONDAY NIGHT INTO TUESDAY OVER FAR SOUTHWEST KANSAS AS
THE REMAINS OF THE WEST COAST SYSTEM MOVE OUT INTO THE CENTRAL AND
SOUTHERN PLAINS. THROUGH THE REMAINDER OF THE EXTENDED PERIOD WE
SHOULD SEE WARMER TEMPERATURES RETURN AS UPPER LEVEL RIDGING BUILDS
BACK INTO THE CENTRAL PART OF THE COUNTRY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 215 PM CDT SAT MAR 30 2013
SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE SOUTHEAST ACROSS
WESTERN KANSAS DURING THE LATE EVENING HOURS. A COLD FRONT WILL MOVE
SOUTH TIED TO A SHORTWAVE TROUGH MOVING SOUTHEAST OUT OF NEBRASKA.
BEHIND THE FRONT...CEILINGS WILL DEVELOP IN THE MVFR RANGE AND WILL
FORECAST 1500 TO 2500 CEILING IN THE 09-15Z TIME FRAME. THERE WILL
BE A 2 OR 3 HOUR PERIOD OF FAIRLY STRONG NORTH TO NORTHWEST WINDS
IMMEDIATELY BEHIND THE FRONT OF 20 TO 25 KNOTS WITH SOME GUSTS ABOVE
30 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 71 35 45 / 40 10 40 40
GCK 38 71 35 44 / 40 10 30 40
EHA 41 71 40 44 / 30 10 30 40
LBL 41 71 42 45 / 30 10 30 40
HYS 38 70 34 44 / 50 10 40 40
P28 47 72 40 46 / 40 10 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
458 PM EDT SAT MAR 30 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 453 PM EDT SAT MAR 30 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A RIDGE OVER THE FAR WRN
CONUS INTO WRN CANADA WHILE DOWNSTREAM TROF WAS AMPLIFYING S THRU
CNTRL CANADA INTO THE NCNTRL CONUS. WITHIN THE DEEPENING TROF...A
SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES HAS BROUGHT A BAND OF
PCPN TO UPPER MI TODAY. PCPN WAS MAINLY RAIN OVER THE W...BUT MIXED
WITH/CHANGED TO SNOW OVER THE CNTRL/E. SNOW WAS MDT/HVY ACROSS
IRON/DICKINSON COUNTIES WHERE A FEW INCHES OF WET SNOW ACCUMULATION
HAS BEEN REPORTED. THE HEAVIER SNOW IS NOW STREAKING E TOWARD LUCE
COUNTY. BACKEDGE OF THE MAIN PCPN AREA WAS OVER CNTRL UPPER MI AS OF
20Z. WITH DEPARTURE OF THIS AREA OF PCPN...ATTENTION IN THE SHORT
TERM SHIFTS TO SHORTWAVE DIGGING SHARPLY INTO THE UPPER GREAT LAKES
LATE TONIGHT/SUN AND THE INCREASINGLY COLDER AIR IT WILL BRING.
INCORPORATING EXTRAPOLATION FOR ENDING PCPN...EXPECT STEADIER PCPN
TO EXIT THE ERN FCST AREA AROUND 03Z WITH ALL OF THE AREA DRY BY
06Z. MAY SEE AN INCH OR SO OF WET SNOW OVER THE INTERIOR E DURING
THE LATE AFTN. LOW CLOUDS AND FOG WERE PRESENT EARLY TODAY BEHIND
THE PCPN AREA IN MN...AND WILL PROBABLY SEE SOME OF THAT AND PERHAPS
SOME -DZ IN MAINLY AREAS THAT SEE UPSLOPING WITH A W WIND FOR A FEW
HRS AFTER PCPN ENDS AND BEFORE THE ONSET OF CAA OVERNIGHT INCREASES
LOW-LEVEL MIXING. BY 12Z...850MB TEMPS ARE PROGGED AT -8/-9C OVER
WRN LAKE SUPERIOR. WHILE THAT IS SHY OF THE THRESHOLD FOR LES GIVEN
WATER TEMPS AROUND 1C...SRN EDGE OF DEEP LAYER FORCING ASSOCIATED
WITH APPROACHING SHORTWAVE AND PRESENCE OF CYCLONIC FLOW MAY
GENERATE SOME LAKE ENHANCED -SHSN OVER NW UPPER MI LATE IN THE
NIGHT.
DURING THE DAY SUN...SHORTWAVE DIGS S ACROSS THE UPPER GREAT
LAKES...BRINGING 100-120M HEIGHT FALLS AT 500MB. ALTHOUGH BEST DEEP
LAYER FORCING PASSES N AND NE OF UPPER MI...DEEP CYCLONIC FLOW AND
SUFFICIENT INCREASE IN MOISTURE DEPTH TO AROUND 10KFT SUGGESTS SCT
TO NMRS -SHSN ARE A GOOD BET. LATE MAR SOLAR INSOLATION WILL ADD A
DIURNAL COMPONENT TO -SHSN COVERAGE OVER THE INTERIOR WHILE
DISRUPTING NORMAL LAKE EFFECT PROCESSES THAT WOULD BE GETTING
UNDERWAY OVER LAKE SUPERIOR AS 850MB TEMPS FALL TOWARD -14C IN THE
AFTN. ALTHOUGH COLUMN BECOMES MORE SUPPORTIVE OF SNOW AS PTYPE AS
THE DAY PROGRESSES...DAYTIME HEATING SHOULD RESULT IN MIX WITH -SHRA
INTO THE MID AFTN OVER THE SCNTRL. WINDS MAY APPROACH ADVY CRITERIA
OVER THE KEWEENAW...BUT WITH MIXED LAYER WINDS LOW/MID 30KT AT MOST
AND ONLY MODEST PRES RISES APPROACHING FROM THE NW...DO NOT
ANTICIPATE WIND ADVY BEING NEEDED AT THIS POINT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 453 PM EDT SAT MAR 30 2013
CONTINUE TO SEE GOOD AGREEMENT FROM GFS/ECMWF/GEM-NH IN OVERALL
LARGER SCALE PATTERN FOR THE LONG TERM. DEEP AND COLD TROUGHING
INITIALLY IN PLACE LEADS TO A PERIOD OF LAKE ENHANCED SNOW FOR
SNOWBELTS FAVORED BY NORTHWEST WINDS SUNDAY NIGHT THROUGH TUESDAY
MORNING. FOCUSED IN ON MORE OF THE DETAILS THIS GO AROUND. WAVE
THAT MOVES THROUGH TO BRING IN THE TROUGHING ON SUNDAY NIGHT PRETTY
SHARP UPSTREAM THIS MORNING OVER NORTHERN MANITOBA INTO NINAVUT.
WENT WITH MODELS THAT WERE SHARPER WITH H5 WAVE AND RESULTING SFC
TROUGH DROPPING ACROSS LK SUPERIOR LATE SUNDAY AFTN INTO SUNDAY
EVENING. SOUNDINGS DURING THAT TIME INDICATE MORE OF A WIDESPREAD
SNOW JUST IN WAKE OF FRONT...ALONG WITH PUSH OF NORTH WINDS TO AROUND
40 MPH. EXPANDED POPS OVER MUCH OF THE NORTH HALF OF CWA SUNDAY
EVENING. SNOWFALL RATES MAY EXCEED 1"/HOUR FOR A COUPLE HOURS AS
THIS BAND OF SNOW MOVES THROUGH. BY MIDNIGHT...MODELS INDICATE
WIDESPREAD DEEPER H8-H7 MOISTURE DEPARTS LEAVING MOST OF THE SNOW
SET UP OVER HIGHER TERRAIN OF WEST AND NCNTRL CWA AND ALSO FOR
SNOWBELTS FROM MUNISING TO NEWBERRY.
LAKE ENHANCED SNOW THAT OCCURS FOR THOSE SNOWBELTS LATER SUNDAY
NIGHT INTO MONDAY MAY BE HEAVY AT TIMES AS SOUNDINGS INDICATE
MOISTURE THROUGH H8 AND INVERSION HEIGHTS UP TO 10KFT. OVER-WATER
INSTABILITY IS SUFFICIENT AS H85 TEMPS ARE AROUND -16C. AT FIRST
GLANCE SEEMS LIKE LAKE EFFECT SNOW WATCH MAY BE IN ORDER. THERE ARE
A COUPLE NEGATIVE FACTORS THOUGH THAT PROHIBITED ISSUANCE OF WATCH.
FIRST OF WHICH IS DRYING NOTED BLO 5KFT LEADING TO MORE OF AN
INVERTED-V LOOK TO SOUNDING...ESPECIALLY OVERNIGHT SUNDAY NIGHT INTO
MONDAY. SECOND NEGATIVE IS SHEAR IN THE MOIST CONVECTIVE LAYER AT
LEAST TO START OUT...BUT THIS DOES EASE LATE SUNDAY NIGHT THOUGH BLYR
WINDS STAY UP TO 30 KTS FROM THE NORTHWEST. BEST SHOT AT HEAVIER SNOW
WOULD BE THROUGH MID-LATE MORNING ON MONDAY AS DAYTIME HEATING/HIGHER
SUN ANGLE WILL ACT TO DISRUPT SNOW SHOWERS AS THE DAY GOES ON. LAKE
EFFECT SNOW SHOWERS MAY INCREASE AGAIN MONDAY NIGHT. DUE TO COMBO OF
THE LAKE EFFECT SNOWS AND BLOWING SNOW...LIKELY WILL NEED ADVISORY
HEADLINES INTO MONDAY NIGHT AND TUESDAY MORNING.
SINCE THERE IS NOT MUCH BLOCKINESS DOWNSTREAM...DEEP TROUGH WILL REMAIN
PROGRESSIVE WITH RISING HEIGHTS DEVELOPING OVER UPPER LAKES AS EARLY
AS TUESDAY. SUFFICIENTLY COLD AND MOIST ENOUGH FOR LK EFFECT BUT
LARGER SCALE NEGATIVES SHOULD RESULT IN DIMINISHING TREND TO LK
EFFECT BY TUESDAY AFTN. POPS REFLECTED THIS FOR MOST PART...JUST
NEEDED SOME MINOR TWEAKS.
AFTER PARTIAL CLEARING AND WARMER CONDITIONS FOR WEDNESDAY ANOTHER
SHORTWAVE TROUGH THEN SWINGS ACROSS MANITOBA AND NORTHERN ONTARIO
WEDNESDAY NIGHT AND THURSDAY. ASSOCIATED COLD FRONT MOVES ACROSS
UPPER LAKES ON THURSDAY. DPROG/DT FROM EARLIER GFS/ECMWF RUNS
INDICATED A SLOWER TREND WITH SHORTWAVE POINTING TO MOST OF
PRECIPITATION FROM THE SYSTEM TAKING PLACE ON THURSDAY OVER UPPER
MICHIGAN. 12Z GFS REALLY SPED UP AND SEEMS OUT OF PLACE NOW WITH
PCPN TIMING. 1000-500MB AND 1000-850MB THICKNESSES INDICATE MIX OF
RAIN/SNOW. LIMITED MOISTURE WILL KEEP AMOUNTS LIGHT. COOLER AND DRY
IN WAKE OF COLD FRONT INTO FRIDAY.
QUESTIONS INCREASE FOR NEXT WEEKEND. GOOD BET THAT UPPER LAKES WILL
BE ON THE SOUTHERN EDGE OF STRONGER JET STREAM RIDING ALONG SOUTHERN
TIER OF CANADA. AS MID-LEVEL FLOW BECOMES MORE WESTERLY MODELS
INDICATE SHORTWAVE TROUGH AND SFC-H85 LOWS VCNTY OF NORTHERN PLAINS
INTO WESTERN GREAT LAKES BY 12Z SATURDAY. POOR CONSISTENCY ON WHERE
SFC-H85 LOWS SET UP THOUGH. LATEST ECMWF/GFS CONTINUE TO INDICATE
FARTHER NORTH LOW WITH QPF INTO UPPER LAKES BY NEXT SATURDAY WHILE
EARLIER RUNS KEPT MOST OF QPF TO SOUTH. 1000-500MB AND 1000-850MB
THICKNESSES AT OR ABOVE 540DAM AND 1305M AND H85 TEMPS OVER 0C INTO
WESTERN CWA INDICATE MIX OF RAIN AND SNOW. CONSENSUS OF MODELS CAME
UP WITH HIGHER CHANCE POPS WHICH WILL WORK IF THE NORTHERN TREND
CONTINUES IN THE MODELS. JUST CANNOT SEEM TO SHAKE THIS COOLER AND
ACTIVE WEATHER PATTERN AS WE HEAD INTO THE FIRST WEEK OF APRIL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 134 PM EDT SAT MAR 30 2013
AREA OF PCPN ASSOCIATED WITH LOW PRES TROF HAS SHIFTED E OF KIWD AND
WILL SOON BE E OF KCMX. PER SATELLITE IMAGERY AND PER SFC OBS
SHOWING INCREASING SFC T/TD SPREADS UPSTREAM...THERE SHOULD BE
SUFFICIENT DRYING BEHIND TROF TO ALLOW IFR CONDITIONS TO IMPROVE TO
MVFR AND THEN VFR AT KIWD BY LATE AFTN. MEANWHILE...AT KCMX...EXPECT
IFR/LIFR CONDITIONS TO IMPROVE TO MVFR LATE IN THE AFTN. APPROACH OF
NEXT DISTURBANCE WILL BRING A RETURN TO MVFR CONDITIONS AT KIWD
OVERNIGHT. EXPECT INCREASING POTENTIAL OF -SHSN AND CONTINUED MVFR
AT KIWD/KCMX LATE TONIGHT/SUN MORNING AS DISTURBANCE ARRIVES. GUSTY
WNW WINDS WILL DEVELOP FOLLOWING NEXT SFC TROF PASSAGE LATE MORNING.
AT KSAW...IFR/LIFR CONDITIONS WITH -SN/-RA SHOULD IMPROVE TO MVFR
LATE AFTN AS PCPN EXITS. DRYING IS MORE UNCERTAIN AT KSAW DUE TO
LIGHTER WIND REGIME AND LESS POTENTIAL TO ADVECT DRIER AIR INTO THE
AREA. ALTHOUGH WESTERLY WIND WOULD FAVOR DOWNSLOPE DRYING...OPTED TO
MAINTAIN MVFR THRU THE EVENING AS WINDS ARE LIGHT. AS WINDS DIMINISH
FURTHER OVERNIGHT...MAY SEE IFR CIGS DEVELOP. EXPECT IMPROVEMENT TO
MVFR IN THE MORNING UNDER STRENGTHENING CAA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 453 PM EDT SAT MAR 30 2013
STRONGER DISTURBANCE MOVING INTO THE UPPER LAKES SUN WILL USHER
COLDER AIR OVER LAKE SUPERIOR WHILE SFC LOW PRES DEEPENS TO THE E
AND NE. THIS WILL RESULT IN STRENGTHENING NW WINDS ACROSS THE LAKE.
IN FACT...NW GALES ARE EXPECTED TO DEVELOP OVER CNTRL AND ERN LAKE
SUPERIOR SUN AFTN. UNDER SLOW MOVING WEATHER PATTERN WITH COLD
UNSTABLE AIR OVER THE LAKE...THE GALES WILL LIKELY CONTINUE INTO
TUE. FREEZING SPRAY WILL ALSO DEVELOP SUN NIGHT AND LINGER INTO TUE
AS UNSEASONABLY COLD AIR SETTLES OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 2 PM SUNDAY TO 8 PM EDT TUESDAY FOR LSZ264>267.
GALE WARNING FROM 2 PM SUNDAY TO 6 PM EDT MONDAY FOR LSZ244-245-
249>251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1213 PM CDT SAT MAR 30 2013
.UPDATE...
ISSUED AT 1212 PM CDT SAT MAR 30 2013
STRATUS CONTS TO MIX OUT. ONLY THE FAR SE FRINGE OF THE FCST AREA
HAS ANY STRATUS OVC BUT IT IS RAPIDLY THINNING/DISSIPATING. FCST
TEMPS WERE RUNNING TOO WARM WHERE STRATUS HAS IMPEDED WARMING. SO
MERGED CURRENT OBS WITH THE FCST 3 HRS IN ADVANCE TO GET BACK ON
THE TEMP CURVE. DWPTS CONT MUCH HIGHER THAN FCST. SO USED HRRR FOR
18Z AND NAM FOR 21Z/00Z AND INTERPOLATED WITH CURRENT OBS.
THE STRATUS WILL CLEAR RESULTING IN A RAPID INCREASE IN TEMPS. GRI
IS ALREADY 60F. SO WE MAY NEED TO INCREASE HIGH TEMPS. THE FIRST
BATCH OF MID-LEVEL SHWRS WILL BE MOVING INTO VALLEY/GREELEY
COUNTIES WITHIN THE HR. AT THIS POINT BELIEVE THE SUB-CLOUD LAYER
IS TOO DRY FOR SPRINKLES. CLOUD BASES ARE AVERAGING AROUND 10K FT.
THE 4 AM FCST EMPHASIZES SHWR CHANCES OVER THE WRN FRINGE OF THE
FCST AREA THIS AFTN. BASED ON CURRENT SATL WE MADE NEED TO
RECONFIGURE THEM MORE ACROSS OUR NRN COUNTIES.
UPDATE ISSUED AT 915 AM CDT SAT MAR 30 2013
ESTF UPDATE EXTENDED THE DENSE FOG ADVY THRU 16Z BUT WE WERE ABLE
TO REMOVE SOME COUNTIES. VIS SATL SHOWS STRATUS/FOG IS SHIFTING S.
IT/S THIN AND SUN WARMING THE GROUND AROUND ITS EDGES...EXPECT
MIXING WILL DISSIPATE THE FOG/STRATUS BY NO LATER THAN 18Z.
SOME ADJUSTMENTS TO SHORT-TERM CLOUDS WERE ALSO MADE. WE MAY NEED
TO ADJUST TEMP CURVES AS STRATUS WILL HAMPER HEATING OVER THE NEXT
COUPLE HRS.
PLEASE SEE UPDATED AVN SECTION.
UPDATE ISSUED AT 650 AM CDT SAT MAR 30 2013
AS MENTIONED IN THE SHORT-TERM DISCUSSION BELOW...REMNANT MOISTURE
FROM LAST NIGHTS RAIN HAS PROVIDED HIGH DEWPOINTS AND WITH THE
LOWER TROPOSPHERE READILY RADIATING OUT...NEAR-ZERO TO ZERO LOW
LEVEL DEWPOINT DEPRESSIONS HAVE RESULTED ACROSS MUCH OF THE CWA.
IN ADDITION...AS OF 11Z THE SURFACE TROUGH WAS NOTED BISECTING THE
CWA FROM NORTHEAST TO SOUTHWEST. THE LOW LEVEL WIND FIELD ACROSS
OUR CWA HAS BECOME VERY LIGHT AS A RESULT. THE COMBINATION OF LOW
DEWPOINT DEPRESSIONS AND A LIGHT WIND HAS RESULTED IN WIDESPREAD
FOG DEVELOPMENT ACROSS THE CWA...WITH MANY LOCATIONS NEAR OR BELOW
1/4SM. THIS FOG SHOULD DIMINISH RAPIDLY POST SUNRISE AS DIABATIC
HEATING COMMENCES THUS PROVIDING INCREASING BOUNDARY LAYER HEIGHT
AND MIXING. UNTIL THAT TIME HOWEVER...DENSE FOG WILL PERSIST
ACROSS MUCH OF THE AREA AND AS A RESULT...WENT AHEAD WITH A DENSE
FOG ADVISORY...IN EFFECT UNTIL 14Z...FOR LOCATIONS GENERALLY ALONG
AND NORTHWEST OF A LINE FROM OSBORNE TO OSCEOLA. REMAINDER OF THE
FORECAST REMAINS IN GOOD SHAPE WITH ONLY MINOR TWEAKS MADE TO
HOURLY TEMPERATURE...DEWPOINT AND WIND GRIDS TO BETTER REFLECT
CURRENT CONDITIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM CDT SAT MAR 30 2013
OVERNIGHT UPPER AIR ANALYSIS INDICATES NORTHWESTERLY MID AND UPPER
LEVEL FLOW OVER THE WESTERN HALF OF THE CONUS...WITH QUASI-ZONAL
FLOW PERSISTING ACROSS THE EAST. MID AND UPPER LEVEL FLOW OVER OUR
AREA MAXES OUT AT AROUND 55KTS NEAR 200MB PER 00Z SOUNDING DATA
FROM KOAX. WATER VAPOR IMAGERY INDICATES A MID LEVEL PERTURBATION
MOVING OVER THE CENTRAL PLAINS...WITH ANOTHER MID LEVEL
PERTURBATION OVER THE NORTHERN PLAINS. AT THE SURFACE A TROUGH OF
LOW BAROMETRIC PRESSURE EXISTS FROM EASTERN SOUTH DAKOTA INTO
WESTERN NEBRASKA AND WESTERN KANSAS. THE SYNOPTIC LOW LEVEL WIND
FIELD REMAINS FROM THE SOUTHEAST ACROSS OUR CWA AS A
RESULT...ALTHOUGH REMNANT OUTFLOW FROM EARLIER CONVECTION HAS
DISRUPTED THE SYNOPTIC FLOW AT A FEW LOCATIONS ACROSS OUR CWA.
RADAR DATA FROM KUEX INDICATES LINGERING CONVECTION OVER EASTERN
NEBRASKA...WITH SOME OF THIS ACTIVITY STILL IMPACTING EXTREME
EASTERN PORTIONS OF OUR CWA. REGIONAL RADAR DATA ALSO INDICATES
ADDITIONAL CONVECTION ONGOING ACROSS PORTIONS OF CENTRAL AND
EASTERN KANSAS. CLOUDY SKIES PERSIST OVER EAST/SOUTHEASTERN
PORTIONS OF OUR CWA WHERE CONVECTION IS NEAR AND ALTHOUGH CLEARING
SKIES HAVE BEEN NOTED FARTHER WEST/NORTHWEST ACROSS THE
AREA...PATCHY FOG IS QUICKLY REPLACING MUCH OF THE CLEARING WHICH
HAS BEEN OBSERVED.
0.37" OF RAIN WAS OBSERVED HERE AT THE OFFICE FROM OVERNIGHT
CONVECTION...WITH ANYWHERE FROM A FEW TENTHS OF AN INCH TO AROUND
A HALF INCH OF RAIN...MAYBE MORE...LIKELY OBSERVED ACROSS MUCH OF
THE CWA. REMNANT MOISTURE FROM THIS RAINFALL IS PROVIDING
RELATIVELY HIGH SURFACE DEWPOINTS EARLY THIS MORNING...GENERALLY
IN THE MID 40S TO LOWER 50S ACROSS OUR CWA. WITH THE
AFOREMENTIONED CLEARING SKIES BEHIND THE PRIMARY AREA OF
CONVECTION...THE LOWER TROPOSPHERE IS RADIATING OUT VERY QUICKLY
THUS RESULTING IN NEAR-ZERO LOW LEVEL DEWPOINT DEPRESSIONS. IN
ADDITION THE LOW DEWPOINT DEPRESSION...THE LOW LEVEL WIND FIELD IS
ALSO DECREASING IN INTENSITY AS THE SURFACE TROUGH...CURRENTLY
OVER WESTERN NEBRASKA AND WESTERN KANSAS...APPROACHES FROM THE
WEST. THESE INGREDIENTS ARE PROVIDING THE DEVELOPING FOG WE HAVE
NOTICED ACROSS OUR WESTERN CWA THROUGH THE PAST FEW HOURS AND
THESE ARE TRENDS WHICH ARE EXPECTED TO CONTINUE THROUGH SUNRISE OR
SHORTLY THEREAFTER. GIVEN THIS...WENT AHEAD AND INTRODUCED PATCHY
FOG TO THE FORECAST FOR THIS MORNING.
MODEL GUIDANCE SUGGESTS DRY CONDITIONS WILL BE OBSERVED ACROSS OUR
AREA THROUGH MUCH OF TODAY ONCE THE CURRENT BATCH OF CONVECTION
PUSHES OFF TO THE EAST. AS A RESULT...DRY CONDITIONS ARE IN THE
FORECAST THROUGH MID AFTERNOON. BY MID TO LATE AFTERNOON
HOWEVER...FORECAST PROXIMITY SOUNDINGS FROM ACROSS OUR
SOUTH/SOUTHEASTERN CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST
THE CONVECTIVE TEMPERATURE WILL BE REACHED THUS PROVIDING THE
OPPORTUNITY FOR ISOLATED CONVECTION. WENT AHEAD WITH 20% POPS
ACROSS OUR SOUTH/SOUTHEAST DURING THE MID AND LATE AFTERNOON HOURS
AS A RESULT. IN ADDITION TO THE POSSIBILITY OF AFTERNOON
CONVECTION...GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND
SREF-MEAN ALL SUGGEST THE MID LEVEL PERTURBATION...CURRENTLY OVER
THE NORTHERN PLAINS...WILL CONTINUE MOVING SOUTHEAST AND NEAR OUR
AREA LATE THIS AFTERNOON. GUIDANCE CURRENTLY SUGGESTS THERE SHOULD
BE JUST ENOUGH LOW TO MID TROPOSPHERIC MOISTURE AND JUST ENOUGH
OMEGA...PERHAPS APPROACHING 5-UBAR/S...FOR PRECIPITATION
PRODUCTION ACROSS WESTERN PORTIONS OF OUR CWA BEGINNING MID TO
LATE THIS AFTERNOON. WENT AHEAD WITH ~20% POPS ACROSS OUR WEST MID
TO LATE AFTERNOON AS A RESULT.
ANY SURFACE-BASED CONVECTION ACROSS OUR SOUTH/SOUTHEAST SHOULD
DIMINISH SHORTLY AFTER SUNSET THIS EVENING AS DIABATIC HEATING IS
LOST. PRECIPITATION ACROSS OUR WEST HOWEVER SHOULD SPREAD ACROSS
THE SOUTHWESTERN HALF OF OUR CWA TONIGHT AS OMEGA...AHEAD OF THE
APPROACHING MID LEVEL PERTURBATION...CONTINUES OVERTAKING THE
AREA. TAKING AN EVEN-AVERAGE OF THE NAM...OPERATIONAL
GFS...EC...AND SREF-MEAN PROVIDES RAINFALL AMOUNTS OF ~0.05"
ACROSS SOUTHWESTERN PORTIONS OF OUR CWA 00Z-06Z AND AS A
RESULT...WENT AHEAD WITH 30%-40% POPS ACROSS OUR SOUTHWESTERN CWA
00Z-06Z. PRECIPITATION CHANCES QUICKLY COME TO AN END ACROSS OUR
CWA BY 06Z HOWEVER AS THE MID LEVEL PERTURBATION CLEARS THE AREA
AND OMEGA IS LOST. DRY CONDITIONS ARE CURRENTLY FORECAST 06Z-12Z.
SHOULD AFTERNOON CONVECTION ACROSS OUR SOUTH/SOUTHEAST BE
REALIZED...FORECAST PROXIMITY SOUNDINGS...PER THE NAM AND
OPERATIONAL GFS...SUGGEST 500 TO 600J/KG 0-1KM MLCAPE WILL BE
AVAILABLE FOR UPDRAFT PRODUCTION. NOT OVERLY IMPRESSIVE BUT GIVEN
THE LOW FREEZING HEIGHTS TYPICAL THIS TIME OF YEAR...WILL GO AHEAD
AND MENTION SMALL HAIL IN THE HWO. IN ADDITION TO THE SMALL HAIL
THREAT...FORECAST PROXIMITY SOUNDINGS...IN PARTICULAR FROM THE
NAM...SUGGEST DEEP INVERTED-V SOUNDINGS TO AROUND 800MB WILL BE IN
EXISTENCE...THUS PRESENTING THE OPPORTUNITY FOR BRIEF GUSTY WINDS.
GIVEN THIS THREAT...WILL ALSO MENTION SUB-SEVERE WIND GUSTS IN THE
HWO.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 441 AM CDT SAT MAR 30 2013
PRIMARY FORECAST CONCERN FOR THE LONG TERM RESIDES SUNDAY NIGHT
AND MONDAY AS A COLD FRONT PUSHES IN FROM THE NORTH ACROSS THE
CWA. THE MAIN CHALLENGES DURING THE LONG TERM WILL BE
PRECIPITATION AND TEMPERATURES...MAINLY SUNDAY THROUGH MONDAY.
PRESSURE RISES ON THE ORDER OF 10 TO 15 MB WILL BE REALIZED BEHIND
THE FRONT SUNDAY NIGHT. TEMPERATURES ACROSS THE CWA WILL DROP
ROUGHLY 40 DEGREES IN MOST LOCATIONS FROM SUNDAY AFTERNOON TO
MONDAY MORNING...BRINGING A COLD REMINDER OF WINTER-LIKE
TEMPERATURES TO THE AREA. IN OTHER WORDS...WE WILL GO FROM
SLIGHTLY ABOVE NORMAL TEMPERATURES SUNDAY AFTERNOON...TO WELL
BELOW NORMAL TEMPERATURES MONDAY WHEN HIGHS ARE FORECAST TO BE
AROUND 20 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. NORMAL HIGH
TEMPERATURES FOR THIS TIME OF YEAR RANGE FROM THE MID 50S TO THE
UPPER 50S...AND NORMAL LOW TEMPERATURES FOR THIS TIME OF YEAR
RANGE FROM THE LOWER 30S TO THE MID 30S. 850MB TEMPERATURES ARE
TRENDING WARMER INITIALLY BEHIND THE COLD FRONT...SO NOT MUCH SNOW
IS EXPECTED AT THE BEGINNING OF THE EVENT. FORECAST SOUNDINGS ARE
DEPICTING A RELATIVELY WARM LAYER NEAR THE SURFACE...AND THE
REALITY IS THIS LAYER NEAR THE SURFACE WOULD NEED TO COOL MUCH
QUICKER TO GET ANY SNOW TO REACH THE SURFACE. GOING TO HOLD OFF ON
THE MENTION OF ANY SNOW UNTIL AFTER MIDNIGHT ON SUNDAY. THESE
PRECIPITATION CHANCES APPEAR TO BE MOSTLY SYNOPTICALLY DRIVEN. THE
RIGHT REAR QUADRANT OF THE UPPER LEVEL JET WILL SET UP OVER THE
CWA...AND HENCE AN AREA OF DIVERGENT AIR ALOFT WILL BE
REALIZED...HELPING INDUCE RISING AIR BELOW THE JET MONDAY MORNING.
HOWEVER...LITTLE TO NO PRECIPITATION IS EXPECTED AFTER 12Z MONDAY.
IF ANYTHING...THERE MIGHT BE SOME ACTIVITY ACROSS OUR KANSAS
COUNTIES MONDAY MORNING WHERE A SLIGHT CHANCES OF PRECIPITATION
WILL EXIST. CONFIDENCE IS PRETTY HIGH REGARDING THE OUTLOOK OF
PRECIPITATION AFTER 12Z AS THERE IS GOOD AGREEMENT BETWEEN THE
NAM...GFS AND EC.
NORTHWESTERLY FLOW ALOFT WILL DOMINATE THE WEATHER PATTERN THROUGH
MOST OF THE LONG TERM PERIOD. OUTSIDE OF MONDAY...PRECIPITATION
CHANCES ARE LOOKING VERY SLIM. THE LATEST RUN OF THE EC IS NOW
HINTING AT SOME POTENTIAL RAINFALL ACROSS THE CWA WEDNESDAY NIGHT
THROUGH THURSDAY. HOWEVER...THE GFS DOES NOT HAVE ANYTHING NEAR
THE AMOUNT OF COVERAGE OR INTENSITY. SINCE THE LATEST RUN OF THE
EC IS VASTLY DIFFERENT THAN THE PREVIOUS RUN...GOING TO LEAVE THIS
RAIN MENTION OUT FOR NOW UNTIL SOME CONSISTENCY BECOMES EVIDENT
BETWEEN THE MODELS.
HIGH TEMPERATURES WILL BE NEAR NORMAL FOR BOTH WEDNESDAY AND
THURSDAY. TUESDAY HIGHS...ON THE OTHER HAND...WILL BE ROUGHLY 10
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. AND LASTLY...FRIDAY
AFTERNOON HIGHS WILL BE ABOVE NORMAL...WITH LOCATIONS ACROSS THE
SOUTH FLIRTING WITH 70 DEGREES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1212 PM CDT SAT MAR 30 2013
THIS AFTN: VFR WITH A 7-10K FT MID-LEVEL CIGS GRADUALLY INVADING
FROM THE NW. N WINDS GUST TO 20 KTS AT TIMES.
TNGT: VFR MID-LEVEL CIGS WILL CONT WITH A CHANCE FOR A BRIEF SHWR
OR SPRINKLES. AFTER 08Z CLEARING. WINDS DIMINISH TO LESS THAN 10
KTS AND THEN SHIFT TO WNW.
SUN THRU 18Z: VFR WITH ESSENTIALLY SKC. NW WINDS AVERAGE 10 KTS.
CIG CONFIDENCE: HIGH
VSBY CONFIDENCE: HIGH
WIND CONFIDENCE: HIGH
WX CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...BRYANT
LONG TERM...GUERRERO
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
359 PM EDT SAT MAR 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE REGION TONIGHT. A TROUGH OF
LOW PRESSURE WILL MOVE THROUGH THE OHIO VALLEY ON
SUNDAY...PROVIDING A CHANCE OF RAIN. A COLD FRONT WILL THEN MOVE
THROUGH SUNDAY NIGHT...PROVIDING COOLER TEMPERATURES FOR THE FIRST
PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A RELATIVELY DRY SURFACE AIR MASS HAS INHIBITED CUMULUS
DEVELOPMENT TODAY. A LOOK AT SURFACE OBS SHOWS THAT DEWPOINTS OVER
THE REGION REMAIN IN THE 20S TO LOWER 30S...WITH DEWPOINTS OVER 40
SOUTH AND WEST OF A BOUNDARY THAT CUTS THROUGH THE FAR
SOUTHWESTERN TIP OF INDIANA. AT THE SAME TIME...HIGH CLOUDS HAVE
BEEN INCREASING...AND MOISTURE IS EXPECTED TO CONTINUE TO LOWER
THROUGH THE NEAR TERM OF THE FORECAST.
THE FOCUS FOR PRECIPITATION WILL BE ON A SHORTWAVE CURRENTLY
MOVING ACROSS MISSOURI AND INTO ILLINOIS. THERE WILL BE EFFECTS ON
THE CWA BEFORE MORNING...BUT FOR THE SAKE OF EASE...THIS FEATURE
WILL BE DISCUSSED IN THE SHORT TERM SECTION OF THE AFD.
WITH CLOUDS MOVING IN...AND WARM ADVECTION AHEAD OF THE
SHORTWAVE...OVERNIGHT TEMPS WILL BE AT LEAST TEN DEGREES WARMER
THAN LAST NIGHT. MIN TEMP VALUES ARE NEAR OR SLIGHTLY WARMER THAN
THE MODEL BLEND...WHICH EXHIBITS A RELATIVELY SMALL
SPREAD. HOWEVER...THE FORECAST IS NOT AS WARM AS THE RAP13.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
A SHORTWAVE CURRENTLY MOVING THROUGH THE MIDDLE MISSISSIPPI VALLEY
WILL BEGIN TO AFFECT THE WESTERN CWA BY 06Z. THE AMPLITUDE OF THIS
SHORTWAVE IS NOT ESPECIALLY STRONG...AND IT IS SOMEWHAT TOUGH TO
DISCERN WHEN LOOKING ONLY AT 500MB HEIGHT CONTOURS. WITH THE DRY
AIR IN PLACE OVER MUCH OF THE OHIO VALLEY RIGHT NOW...IT IS NOT
ENTIRELY SURPRISING THAT THE TREND HAS BEEN TOWARD SLIGHTLY DRIER
SOLUTIONS FOR SUNDAY MORNING. THE SIGNAL FROM THE HIGH-
RESOLUTION OUTPUT IS CONFLICTING...WITH THE 12Z SPC-WRF INDICATING
ONLY SCATTERED SHOWERS (AND SOME BIG DRY PATCHES)...AND THE MOST
RECENT HRRR RUN SHOWING A SOLID AREA OF PRECIPITATION FOR THE
SOUTHERN HALF OF THE CWA. TIMING WAS ADJUSTED ON THE POPS...WITH A
SLIGHTLY ADJUSTMENT DOWNWARD IN VALUE AS WELL...AND NO HIGHER THAN
LIKELY FOR THE SOUTHERN CWA.
AN ASPECT OF THE SYSTEM THAT IS AGREED UPON FROM ALL SOURCES IS A
SPLIT IN THE PRECIPITATION BETWEEN A SOUTHERN AREA OF
PRECIPITATION (PRIMARILY AFFECTING KENTUCKY AND TENNESSEE) AND
WITH A NORTHERN STREAM SYSTEM MOVING THROUGH MICHIGAN. THE
NORTHERN SYSTEM WILL LAG BEHIND THE SOUTHERN SYSTEM BY SEVERAL
HOURS...BUT THIS WILL LIKELY ACT TO INITIATE MORE SHOWERS OVER THE
EASTERN CWA THROUGH MID-AFTERNOON. SPC SREF PARAMETERS INDICATE
THAT SOME WEAK INSTABILITY COULD BUILD IN TO THE SOUTHEASTERN AND
EASTERN CWA DURING THIS TIME FRAME...SO THUNDER WAS KEPT IN THE
FORECAST.
BY SUNDAY NIGHT...A COLD FRONT WILL BE MOVING INTO THE NORTHERN
PORTIONS OF THE CWA. WHILE THE COLD ADVECTION IS NOTABLE BEHIND
THE FRONT...THE SURFACE PRESSURE PATTERN IS WEAK...AND FORCING
IS ALMOST NON-EXISTENT. AS A RESULT OF THIS...THE FRONT SHOULD
PASS THROUGH DRY. HOWEVER...IN A REGION OF COLD ADVECTION BEHIND
THE FRONT...A WEAK RIPPLE IN THE FLOW (ROUNDING THE SOUTHWESTERN
EDGE OF THE LARGE UPPER TROUGH) WILL PASS INTO THE CWA. THIS
FEATURE MAY BRING A BAND OF LIGHT PRECIPITATION DURING THE FIRST
TWO-THIRDS OF MONDAY. HOWEVER...THIS HAS BEEN MODELED DRIER ON THE
LAST SET OF RUNS...SO POPS HAVE BEEN LIMITED TO 20 PERCENT.
TEMPERATURES SUPPORT A MIX OF SNOW AND RAIN (WITH GENERALLY SNOW
IN THE NORTH AND GENERALLY RAIN IN THE SOUTH)...BUT AS QPF IS
EXTREMELY LIGHT...THE DAY SHOULD NOT BE A STRIKEOUT.
WITH THE ONLY SIGNIFICANT TEMPERATURE ADVECTION OCCURRING SUNDAY
NIGHT WITH THE COLD FRONT...TEMPS SHOULD REMAIN GENERALLY DIURNAL
THROUGH THE PERIOD. AFTER A DAY OF COLD ADVECTION AND AS SKIES
CLEAR OUT MONDAY NIGHT...TEMPS APPEAR TO BE SET TO DROP INTO THE
20S...10-15 DEGREES BELOW NORMAL FOR EARLY APRIL.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
DEEP MID LVL TROUGH WILL PROGRESS EASTWARD TUESDAY INTO WEDNESDAY
...ALLOWING SFC HIGH PRESSURE TO SETTLE INTO THE GREAT LAKES AND
OHIO VALLEY. ON TUESDAY...THERE COULD BE SOME DIURNALLY DRIVEN
CUMULUS BUT IT LOOKS LIKE MOST OF THE REGION WILL BE MOSTLY SUNNY. IT
SHOULD BE MOSTLY CLEAR TUESDAY NIGHT AND MOSTLY SUNNY ON WEDNESDAY.
COLDEST TEMPERATURES ARE EXPECTED TUESDAY INTO TUESDAY NIGHT. HIGHS
ON TUESDAY WILL RANGE FROM THE UPPER 30S NORTH TO THE MID 40S SOUTH.
LOWS TUESDAY NIGHT WILL DROP INTO THE LOWER AND MID 20S. SOME
MODIFICATION IS EXPECTED ON WEDNESDAY BUT TEMPERATURES WILL REMAIN
BELOW NORMAL FOR EARLY APRIL. HIGHS WILL RANGE FROM THE LOWER 40S NE
TO THE UPPER 40S SOUTHWEST.
UPR LVL FLOW WILL TRANSITION TO A MORE ZONAL PATTERN LATE IN THE
WEEK. THERE WILL BE A SPLIT FLOW BETWEEN NRN STREAM ENERGY AND SRN
STREAM ENERGY. MODELS HAVE BEEN OSCILLATING ON HOW THE NRN STREAM
ENERGY WILL INTERACT WITH THE SRN STREAM ENERGY. FOR NOW...HAVE KEPT
AN UPR LVL LOW AND PCPN WITH THE SRN STREAM ENERGY TO OUR SOUTH AND
EAST THURSDAY INTO FRIDAY WHILE A WEAK COLD FRONT DROPS SOUTHEAST
THROUGH THE REGION THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL
CONTINUE TO MODERATE WITH HIGHS IN THE 50S ON THURSDAY AND 50S TO
NEAR 60 ON FRIDAY.
FOR FRIDAY NIGHT INTO SATURDAY...SURFACE HIGH PRESSURE WILL PUSH
INTO THE REGION AND WILL EVENTUALLY MOVE EAST. DRY WEATHER WITH
TEMPERATURES NEAR SEASONAL NORMALS ARE EXPECTED.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
LOCATIONS OF GREATEST CONFIDENCE FOR SHRA WILL BE KCVG/KLUK WITH
BEING ON THE NORTHERN FRINGE OF TONIGHTS SHORTWAVE PUSHING ACROSS
THE TN/CUMBERLAND VALLEYS. CARRIED THUNDER IN THE 10-13Z
TIMEFRAME...THOUGH CONFIDENCE NOT WITH THE LATEST MODEL RUNS.
WOULD STILL EXPECT PERIOD OF MVFR CIGS MAINLY AT KDAY/KCVG/KLUK
AND POSSIBLY KILN CLOSER TO THE SOUTHERN STREAM S/WV. SECONDARY
WAVE SWINGING ACROSS NORTHERN AREA MAY NOT HAVE AS MUCH OF AN
EFFECT ON TAF SITES AS CURRENT MODELS PLACE BEST CHANCE FOR
PRECIPITATION FURTHER NORTH THAN TAF SITES. AS A RESULT...MVFR
LIMITED TO MAINLY THE SOUTHERN SYSTEM FROM THE 10Z-15Z
TIMEFRAME...WITH WESTERLY WINDS BECOMING A LITTLE MORE GUSTY AFTER
20Z.
OUTLOOK...MVFR CONDITIONS AGAIN ON MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...JDR
AREA FORECAST DISCUSSION
NWS TULSA OK
1225 PM CDT SAT MAR 30 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
MORNING ROUND OF SHOWERS AND STORMS EXITING THIS MORNING WITH
GENERALLY VFR CONDITIONS IN ITS WAKE...BUT SOME MVFR CEILINGS MAY
LINGER AN HOUR OR SO OVER WESTERN ARKANSAS. SOME ADDITIONAL
THUNDERSTORMS MAY DEVELOP LATE IN THE AFTERNOON TOWARD 00Z WITH AN
INCREASE TONIGHT AS A COLD FRONT PUSHES THROUGH 06-12Z. WHILE
PREVAILING CONDITIONS SHOULD REMAIN JUST ABOVE VFR LEVELS...A
PERIOD OF MVFR OR EVEN IFR CONDITIONS WITHIN THAT TIME FRAME IS
LIKELY AS THE FRONT PASSES. CONDITIONS WILL IMPROVE FROM THE NORTH
AFTER 12Z.
&&
.PREV DISCUSSION... /ISSUED 1026 AM CDT SAT MAR 30 2013/
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE ACROSS EAST CENTRAL OK
AND NORTHWEST AR THIS MORNING BUT CONTINUE TO DECREASE IN
INTENSITY AS THEY SHIFT SOUTHEAST. EXPECT THIS ROUND TO MOVE OUT
OF THE FORECAST AREA AROUND 19-20Z WITH ENOUGH BREAKS IN CLOUDS TO
SEND TEMPS WELL INTO 70S ACROSS MUCH OF EASTERN OK...AND REMAINING
A BIT COOLER IN FAR EASTERN AREAS. RE-DEVELOPMENT OF STORMS ALONG
ANY BOUNDARIES THIS AFTERNOON APPEARS QUESTIONABLE...THOUGH
CERTAINLY NOT A ZERO CHANCE IN UNSTABLE AND WEAKLY CAPPED
ENVIRONMENT. HAVE UPDATED POPS BASED ON RADAR TRENDS FOR THE
MORNING AND HAVE REDUCED THEM SOME FOR THE AFTERNOON ACROSS
WESTERN AREAS. ALSO KNOCKED A FEW DEGREES OFF FORECAST HIGHS IN
FAR NW ARKANSAS.
PREV DISCUSSION... /ISSUED 623 AM CDT SAT MAR 30 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VARIABLE SKY CONDITIONS WILL PERSIST THROUGH THE MORNING
HOURS...WITH AREAS OF MVFR/IFR CIGS MAINLY ACROSS SOUTHEAST
OK AND WEST CENTRAL AR. LOCALIZED LOWER CIGS/VSBYS WILL
OCCUR WITH SHOWERS/THUNDERSTORMS THROUGH THE MORNING HOURS.
SOME IMPROVEMENT IS EXPECTED INTO THE AFTERNOON...WITH
AREAS OF SHOWERS/THUNDERSTORMS DEVELOPING AGAIN BY LATE
AFTERNOON OR EARLY EVENING.
PREV DISCUSSION... /ISSUED 457 AM CDT SAT MAR 30 2013/
DISCUSSION...
WAVE TRAIN ROLLING ALONG IN NORTHWEST FLOW HAULING
CLUSTERS OF SHOWERS AND THUNDERSTORMS THIS MORNING.
SOME OF THE STRONGER THUNDERSTORMS PROVED EFFICIENT
HAIL PRODUCERS OVERNIGHT.
IN THE SHORT TERM FOLLOWED HRRR MODEL WHICH HAS BEEN
GOOD LAST SIX HOURS WITH CONVECTIVE ACTION. BULK OF
CURRENT PRECIP EAST OF NORTHWEST AR ZONES AROUND 18Z.
QUESTION THEN BECOMES WHAT BOUNDARIES ARE LEFT BEHIND
TO FIRE LATE AFTERNOON..OR EVENING. TEMPERATURES INTO
THE MID 70S THIS AFTERNOON..IN ADVANCE OF A WEAK COOL
FRONTAL BOUNDARY SAGGING INTO THE FORECAST AREA WILL
LIKELY IGNITE ANOTHER ROUND OF THUNDER. CAPE VALUES
IN THE 2000 J/KG NEIGHBORHOOD AND SUFFICIENT SHEAR
WILL BE CAPABLE OF LARGE HAIL PRODUCTION.
CONVECTION MIGRATING SOUTHEAST OVERNIGHT LEAVING MOST
AREAS NORTH OF INTERSTATE 40 WITH A DRY WARM EASTER.
SHOWERS THUNDER MOST LIKELY NEAR OR SOUTH OF THE RED
RIVER.
NEXT WAVE AND REAL COLD FRONT ARRIVE SOMETIME MONDAY.
WRF VERY FAST AND THE OUTLIER IN BRINGING IN THE COLD
AIR COMPARED TO MOST OF THE OTHER MODELS. RESULTING
WRF MOS BASED MAX TEMPS SOME 15 TO 20 DEGREES COLDER
FOR NORTHERN LOCATIONS. USED FOUR MODEL MAX TEMP.
MODEL DIFFERENCES CONTINUE TO PLAGUE THE MIDWEEK TIME
PERIOD. ECMWF CONSISTENT WITH ITSELF BRINGING AN UPPER
LOW DIRECTLY OVER FORECAST AREA. MEANWHILE GFS WEAKER
DRIER... MORE PROGRESSIVE WITH THE FEATURE. ECMWF TOO
GOOD TO TOTALLY IGNORE..CHANCE POPS MIDWEEK.
GW
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...99
LONG TERM....99
AVIATION...14
AREA FORECAST DISCUSSION...CORRECTED
NWS MEDFORD OR
256 PM PDT SAT MAR 30 2013
.SHORT TERM...A CUTOFF LOW OFF THE CENTRAL CALIFORNIA COAST
REMAINS THE MAIN WEATHER MAKER FOR THE NEXT COUPLE DAYS. THIS LOW
IS MOVING TOWARDS REGION TODAY AND IS FORECAST TO MOVE INLAND
SUNDAY AND MONDAY. THEN A HIGH PRESSURE RIDGE WILL BRING WARM AND
DRY CONDITIONS BEGINNING TUESDAY.
AHEAD OF THIS LOW...MOISTURE AND INSTABILITY ARE INCREASING TODAY.
ISOLATED THUNDERSTORMS HAVE DEVELOPED EARLY THIS AFTERNOON TO THE
SOUTH IN LASSEN AND SHASTA COUNTY WHERE THE BEST LIFT IS INDICATED
IN THE MESO ANALYSIS AND RAP FORECAST. ALSO MESO ANALYSIS SHOWS
PRECIPITABLE WATER VALUES OF 0.8 INCHES ALONG THE NORTHERN
CALIFORNIA COAST. INLAND PW AMOUNTS RANGE FROM 0.4 TO 0.7 INCHES AND
WILL INCREASE LATE THIS AFTERNOON AND THIS EVENING AS MOISTURE
MOVES UP FROM THE SOUTH AND SOUTHEAST INTO THE AREA. DAYTIME
HEATING WILL RESULT IN SURFACE BASED INSTABILITY AND MODELS SHOW
INCREASING LIFT OVER CENTRAL PORTIONS AND SOUTHERN PORTIONS OF
THE AREA IN THE LATE AFTERNOON AND EVENING. ALSO MODELS SHOW
THAT CAPE WILL INCREASE FROM THE CASCADES WEST DURING THIS PERIOD.
THE INCREASE IN MOISTURE...LIFT AND INSTABILITY WILL ALLOW SHOWERS
AND ISOLATED THUNDERSTORMS TO DEVELOP LATE THIS AFTERNOON INTO
THIS EVENING OVER SISKIYOU AND MODOC COUNTIES IN NORTHERN
CALIFORNIA AND OVER SOUTHWESTERN PORTIONS OF SOUTHERN
OREGON....MAINLY FROM KLAMATH COUNTY WEST. ADDITIONALLY A BAND OF
SHOWERS IS EXPECTED TO MOVE INTO THE CWA FROM THE SOUTH LATE THIS
EVENING AND TONIGHT. SOME ISOLATED EMBEDDED THUNDERSTORMS AS WELL
AS AREAS OF MODERATE TO HEAVY RAIN ARE ALSO POSSIBLE WITH THIS
LINE.
ON SUNDAY...THE LOW BEGINS TO MOVES INLAND TO THE SOUTH AND WILL
BRING CONTINUED MOISTURE AND SHOWERS TO THE AREA. BY
AFTERNOON...EXPECT SHOWERS TO BECOME WIDESPREAD OVER MOST THE
AREA. INSTABILITY INCREASES OVER THE AREA AGAIN SUNDAY
AFTERNOON. HAVE EXPANDED THE SLIGHT RISK OF THUNDERSTORMS OVER THE
INLAND AREAS SUNDAY AFTERNOON INTO SUNDAY EVENING GIVEN THE MODEL
CONSENSUS ON BETTER INSTABILITY...AS WELL AS INCREASED DIVERGENCE
ALOFT AND CONTINUED MOISTURE CONVERGENCE OVER PORTIONS OF THE CWA.
ON MONDAY...MODELS CONTINUE TO SHOW DIFFERENCES ON THE SPEED OF
THE LOW AS IT MOVES EAST INTO NEVADA AND UTAH WITH THE ECMWF
BEING SHOWER THAN THE GFS AND NAM. HAVE COMPROMISED IN THE
FORECAST WITH CHANCE POPS OVER THE CENTRAL AND EASTERN PORTIONS
OF THE CWA AND A SLIGHT CHANCE ELSEWHERE. BY MONDAY NIGHT EXPECT
SHOWER ACTIVITY TO DIMINISH ACROSS THE AREA AS A STRONG RIDGE OF
HIGH PRESSURE BUILDS INTO PLACE.
ON TUESDAY...A RIDGE WILL BRING DRY AND VERY WARM CONDITIONS WITH
HIGHS IN THE UPPER 60S TO MID 70S FOR VALLEYS WEST OF THE CASCADES
AND IN THE MID 60S EAST OF THE CASCADES. THESE WARM AND DRY
CONDITIONS CONTINUE INTO WEDNESDAY.
.LONG TERM...AN ACTIVE PATTERN IS IN THE WORKS STARTING NEXT
THURSDAY AND COULD LAST THROUGH NEXT WEEKEND. THE EC AND GFS
OPERATIONAL AND ENSEMBLE MEANS HAVE BEEN TRENDING IN THIS DIRECTION
FOR THE PAST FEW DAYS. SO CONFIDENCE IS BECOMING HIGHER WE`LL BE
HEADING INTO A COOLER AND WETTER PATTERN....BUT LESS CONFIDENT ON
THE TIMING OF EACH INDIVIDUAL SYSTEM. THE EC IS SLOWER THEN THE
GFS WITH A NEGATIVE TILTED TROUGH MOVING INTO THE AREA THURSDAY
AFTERNOON. SO WE`LL CONTINUE TO GO ABOVE CLIMO FROM THURSDAY
ONWARD IN THE EXTENDED. TEMPERATURES ARE ALSO LIKELY TO BE BELOW
NORMAL DURING THE DAY...BUT NEAR OR SLIGHTLY ABOVE NORMAL AT NIGHT
DUE TO CLOUD COVER AND PRECIPITATION. -PETRUCELLI
&&
.AVIATION...VFR CONDITIONS WILL CONTINUE INTO TONIGHT. HIGH AND MID
LEVEL CLOUDS WILL GRADUALLY INCREASE IN THE AFTERNOON WITH LIGHT
TO MODERATE EAST TO NORTHEAST WINDS ALOFT VEERING TO SOUTHERLY.
THE AIR MASS WILL DESTABILIZE LATE THIS THE AFTERNOON WITH SHOWERS
AND ISOLATED THUNDERSTORMS POSSIBLE OVER THE MOUNTAINS OF SISKIYOU
COUNTY. TEMPORARY MVFR CIGS ARE POSSIBLE EARLY SUNDAY MORNING IN
THE ROGUE VALLEY AND UMPQUA BASIN WITH PARTIAL MOUNTAIN
OBSCURATIONS. -PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...NONE.
$$
CC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1224 PM EDT SAT MAR 30 2013
.SYNOPSIS...
HIGH PRESSURE ACROSS THE REGION WILL GRADUALLY SHIFT EAST AND
OFFSHORE THIS AFTERNOON INTO TONIGHT. THIS WILL RESULT IN MILDER
TEMPERATURES AHEAD OF A COLD FRONT THAT WILL BRING A CHANCE OF
RAIN SHOWERS LATER TONIGHT INTO SUNDAY. ANOTHER COLD FRONT SHOULD
PROVIDE A RETURN TO COLDER CONDITIONS DURING NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1210 PM EDT SATURDAY...
ADJUSTED CLOUD COVER TO AC/CU
FIELDS IN THE MOUNTAINS. MODIFIED TEMPERATURES AND RAISE HIGH
TEMPERATURES A FEW DEGREES ESPECAILLY IN THE SOUTHEAST. WAITING TO
SEE IF ANY SHOWERS DEVELOP THIS AFTERNOON ACROSS THE HIGHER
TERRAIN.
AS OF 943 AM EDT SATURDAY...
THIS MORNING 8AM/12Z RNK SOUNDING DISPLAYED AN INVERSION AROUND
910MB WITH A POCKET OF MOISTURE ABOUT 720 MB AND A WEST TO
NORTHWEST FLOW. HIGH PRESSURE OVER OHIO THIS MORNING WILL TRAVEL
EAST TODAY INTO TONIGHT. THIS WILL RESULT IN PLEASANT WEATHER THIS
AFTERNOON FOR OUR REGION WITH SEASONABLE TEMPERATURES. RNK WRFARW
AND HRRR SUPPORT THE MENTION OF ISOLATED SHOWERS ACROSS SOUTHWEST
PORTIONS OF CWA THIS AFTERNOON AND EVENING. THE MAIN AREA OF RAIN
ASSOCIATED WITH THE WARM FRONT ON TRACK TO DEVELOP OVERNIGHT.
MADE SOME MINOR MODIFICATIONS TO TEMPERATURES...CLOUD COVER AND
POPS FOR TODAY.
AS OF 252 AM EDT SATURDAY...
WARMING TREND CONTINUES OVER THE NEXT 24 HOURS AS HIGH PRESSURE
ACROSS THE REGION THIS MORNING GRADUALLY SHIFTS EAST AND OFFSHORE
ALLOWING A WEAK WARM ADVECTION PATTERN TO TAKE SHAPE. WILL HAVE A
WEAK IMPULSE PASSING TO THE SOUTH EARLY THIS MORNING BEFORE THE
AREA WORKS INTO A WEAK SUBSIDENCE REGION BETWEEN THE RIDGE AND A
WARM FRONT TO THE SW THIS AFTERNOON. THIS LOOKS TO HELP DIMINISH
CLOUDS IN ALL AREAS EXCEPT PERHAPS THE FAR SW WHERE SOME MOISTURE
MAY GET STUCK FROM THE NW NC RIDGES INTO SW VA. MAY ALSO LEAVE IN
THE GOING ISOLATED -RA MENTION IN NW NC EARLY BEFORE DEEPER
MOISTURE EXITS WITH MORE OF AN AC TO CU FIELD ELSW THIS AFTERNOON.
LATEST MODEL THICKNESS COMBO WITH WEAK SW FLOW AND BASED ON MORE
INSOLATION SUPPORTS HIGHS LOW/MID 60S BLUE RIDGE EAST TODAY...AND
MID/UPPER 50S WEST OUTSIDE OF THE HIGHER ELEVATIONS.
WARM FRONT AND ASSOCIATED WEAK VORT AXIS WILL APPROACH FROM THE
SW OVERNIGHT HELPING TURN THE LOW LEVEL FLOW MORE SE THIS EVENING
AHEAD OF THE MAIN BODY OF DEEPER MOISTURE/SHRA THAT WILL BE
NEARING THE WEST SHORTLY AFTER MIDNIGHT. MODELS REMAIN RATHER
CONSISTENT IN SHOWING A SWATH OF BETTER LIFT ACROSS THE NW CLOSER
TO THE MAIN SHORTWAVE AXIS...AND ALONG THE SRN BLUE RIDGE WHERE
AIDED BY WEAK UPSLOPE AND PERHAPS A SECONDARY BAGGY WAVE ALONG THE
WARM FRONT LATE. THIS INITIAL UPSLOPE FLOW SUPPORTS GOING A BIT
FASTER WITH POPS OVERNIGHT WITH ALL EXCEPT THE EASTERN THIRD
SEEING LIKELY/CAT POPS BY DAYBREAK. CANT TOTALLY RULE OUT A RUMBLE
OF THUNDER ESPCLY SW GIVEN DECENT LIFT AND PUNCH OF WARM AIR
COMING IN WITH AN INCREASING 85H JET LIKELY WITH WHATS LEFT OF AN
EARLIER MCS. HOWEVER GIVEN FCST LOW LEVEL STABILITY WONT INCLUDE
FOR NOW. HEAVIEST QPF THRU DAWN LOOKS TO BE OVER THE FAR WEST WITH
AROUND A QUARTER TO ONE HALF INCH POSSIBLE ESPCLY WHERE ENHANCED
BY WEAK UPSLOPE AND SOME EMBEDDED CONVECTION ALOFT. LOW TEMPS
SHOULD BE MUCH MILDER THAN SEEN IN A WHILE WITH UPPER 30S TO MID
40S...WITH PERHAPS A FEW VALLEYS AND EASTERN SPOTS A BIT COLDER
EARLY ON BEFORE RISING LATE AS CLOUDS/SHRA ARRIVE.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 315 AM EDT SATURDAY...
A WARM FRONT WILL SPREAD A QUICK SHOT OF RAIN ACROSS THE REGION
DURING THE FIRST HALF OF SUNDAY. THE COLD FRONT HOLDS TO THE NW LONG
ENOUGH SO THAT MONDAY WILL FEATURE MANY HIGHS IN THE 60S WITH H85
TEMPS FROM +4C TO +8C. ALTHOUGH ITS BEEN SAID WAY TOO MANY TIMES
THIS MARCH...THE COLD SHOT ARRIVING MONDAY NIGHT THROUGH TUESDAY MAY
BE WINTER`S LAST GASP...WITH -10C AT H85 ONCE AGAIN TOUCHING SE WEST
VA. ALTHOUGH THE OP GFS IS GENERATING LIGHT SNOW ACROSS MOSTLY
GREENBRIER MONDAY NIGHT...ALL OTHER MODELS SAY NO...AND ARE MUCH
DRIER AT H85 AND H7.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 115 PM EDT FRIDAY...
COLDER AIR PUSHING IN WITH STRONG CANADIAN HIGH MOVING SE INTO
THE PLAINS. THIS HIGH MOVES INTO THE OHIO VALLEY BY WEDNESDAY AND
SHIFTS EAST OF US THURSDAY. TEMPS WILL AGAIN BE FALLING WELL BELOW
NORMAL WITH HIGHS TUE-WED IN THE UPPER 30S TO MID 40S MTNS...AND
MID 40S TO LOWER 50S EAST.
FOR THE THU NIGHT-FRI TIME FRAME...THE 00Z ECMWF SHOWS THE NEXT
SHORTWAVE PUSHING INTO THE OHIO VALLEY SOUTH TO THE GULF COAST.
MEANWHILE...THE 12Z GFS IS FASTER AND FURTHER SOUTH WITH ITS SYSTEM
KEEPING PRECIP MORE OVER THE SOUTHEAST. THE ECMWF WORKS A WARM FRONT
AND LOW NE TO THE AREA FRIDAY WITH RAIN...AND RETREATING HIGH
PRESSURE. LEANED THE FORECAST TOWARD A WETTER SOLUTION SIMILAR TO
THE ECMWF. SHOULD BE MAINLY RAIN BUT CANNOT RULE OUT SOME WINTRY
PRECIP IF THE COLD AIR IS SLOW TO DISLODGE.
BOTH MODELS AFTER FRIDAY CLOSE OFF AN UPPER LOW ALONG THE EAST
COAST...DELMARVA AREA FOR ECMWF AND EAST OF SOUTH CAROLINA FOR THE
GFS.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1205 PM EDT SATURDAY...
EXPECT GOOD FLYING CONDITIONS TO PREVAIL IN MOST AREAS
INTO/THROUGH EARLY THIS EVENING BEFORE THE APPROACH OF A WARM
FRONT BRINGS AN INCREASING THREAT OF SHOWERS ALONG WITH FLIGHT
RESTRICTIONS BACK INTO MVFR OR IFR RANGE LATER TONIGHT INTO MUCH
OF SUNDAY. LOOKS LIKE MOST OF THE RAINFALL WILL AFFECT THE WESTERN
TAF LOCATIONS SUCH AS KBLF/KBCB SHORTLY AFTER MIDNIGHT...AND THEN
PROGRESS NORTH/EAST OVER THE REMAINDER OF THE FORECAST POINTS BY
DAYBREAK. COULD SEE CIGS/VSBYS RAPIDLY LOWER AS WELL AROUND DAWN
ON SUNDAY AS A PERIOD OF MODERATE TO HEAVY RAIN TRACKS ACROSS
PARTS OF THE AREA AS WELL. AN ISOLATED THUNDERSTORM IS POSSIBLE.
BECAUSE OF THE LIMITED COVERAGE...LEFT OUT OF TAFS FOR NOW.
PASSAGE OF THE WARM FRONT EARLY AND SUBSEQUENT COLD FRONT LATER IN
THE DAY SHOULD BRING END TO RAIN THREAT ALONG WITH CLEARING SKIES
IN DOWNSLOPING AREAS EAST OF THE BLUE RIDGE BY LATE SUNDAY
AFTERNOON. HOWEVER TYPICAL UPSLOPING CLOUDS..AND POSSIBLY SOME
ISOLATED SHOWERS SHOULD MAINTAIN A THREAT FOR AT LEAST OCCASIONAL
MVFR CEILINGS THROUGH SUNDAY NIGHT ACROSS SOUTHEASTERN WV TERMINAL
FORECAST POINTS.
APPROACH OF MUCH MORE POTENT COLD FRONT WILL MAINTAIN MVFR TO
POSSIBLY IFR RESTRICTIONS WITH INCREASING THREAT OF PRECIPITATION
ACROSS UPSLOPE AREAS OF THE WEST LATER MONDAY INTO MONDAY
NIGHT. EXPECT VFR CONDITIONS EAST OF THE BLUE RIDGE TO BE OVERTAKEN
BY AT LEAST MVFR RESTRICTIONS MONDAY NIGHT INTO TUESDAY MORNING AS
COLD FRONT AND ASSOCIATED PRECIPITATION MOVE EAST THROUGH THE
AREA.
PROLONGED PERIOD OF COLD UPSLOPING WINDS AND SNOW SHOWERS WILL
AGAIN MAINTAIN MVFR TO OCCASIONAL IFR RESTRICTIONS TO WESTERN
FLANKS OF THE APPALACHIANS TUESDAY THROUGH WEDNESDAY...BUT WITH A
RETURN TO VFR WEATHER EXPECTED IN DOWNSLOPING AREAS EAST OF THE
BLUE RIDGE FOLLOWING FRONTAL PASSAGE TUESDAY AFTERNOON CONTINUING
INTO WEDNESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/WP
NEAR TERM...JH/KK
SHORT TERM...KM
LONG TERM...WP
AVIATION...JH/KK/WERT