000
FXUS63 KDDC 210907
AFDDDC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
407 AM CDT TUE MAY 21 2013

...UPDATE TO LONG TERM...

.SYNOPSIS...
ISSUED AT 116 AM CDT TUE MAY 21 2013

THE UPPER LEVEL FLOW ACROSS THE CENTRAL UNITED STATES WAS DOMINATED
BY A DEEP UPPER LEVEL CYCLONE CENTERED IN SOUTHEAST NORTH DAKOTA.
NORTH OF THE UPPER LEVEL CYCLONE, A BLOCKING UPPER LEVEL HIGH WAS
CENTERED IN SASKATCHEWAN. ANOMALOUSLY STRONG MID LEVEL FLOW WITH
WIND SPEEDS ABOVE 50KTS AT H5 PREVAILED FROM NEW MEXICO ACROSS
OKLAHOMA TO THE UPPER MIDWEST. VERY COLD AIR ALOFT COVERED THE
CENTRAL PLAINS AND ROCKIES WITH H5 TEMPERATURES AT OR BELOW -16C
ACROSS A WIDE AREA. A VIGOROUS UPPER LEVEL TROUGH WAS EVIDENT ON
SATELLITE IMAGERY IN CENTRAL NEW MEXICO, AND CONSIDERABLE MID AND
HIGH LEVEL CLOUDINESS IN THE REGION OF UPWARD VERTICAL MOTION EAST
OF THE TROUGH COVERED EASTERN NEW MEXICO AND THE TEXAS PANHANDLE.

A MINOR TROUGH ROTATING AROUND THE GYRE CENTERED IN THE NORTHERN
PLAINS EXTENDED FROM CENTRAL NEBRASKA INTO SOUTHEAST COLORADO AT
00Z, AND A REINFORCING SURGE OF COLD AIR IN THE LOWER LEVELS OF THE
ATMOSPHERE WAS SPREADING ACROSS WESTERN KANSAS. THE LEADING EDGE OF
THE COLD AIR ADVECTION EXTENDED FROM SOUTHEAST NEBRASKA TO THE
CENTRAL OKLAHOMA PANHANDLE AT 04Z. AN INCREASE IN NORTHWEST WINDS
AND RISING PRESSURES WAS EVIDENT BEHIND THE SUBTLE BOUNDARY. VERY
RICH LOW LEVEL MOISTURE COVERED THE SOUTHERN PLAINS IN ADVANCE OF A
DRYLINE IN WEST TEXAS, AND A WARM ELEVATED MIXED LAYER WAS EVIDENT
IN THE MID LEVELS FROM WEST TEXAS TO THE UPPER MIDWEST.

UPSTREAM IN THE PACIFIC, A DEEP OCCLUDED CYCLONE OVER THE ALEUTIAN
ISLANDS NEAR 175W WAS FEEDING WARM AIR NORTH INTO AN UPPER LEVEL
RIDGE NEAR 150W, AND A DOWNSTREAM TROUGH NEAR 130W WAS DIGGING
TOWARD THE PACIFIC NORTHWEST.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 207 AM CDT TUE MAY 21 2013

A PERIOD OF QUIESCENT WEATHER WILL PREVAIL IN WESTERN KANSAS THROUGH
WEDNESDAY, AND TEMPERATURES WILL PROVIDE THE BIGGEST FORECAST
CHALLENGE. CONSIDERABLE HIGH LEVEL CLOUDINESS WILL SPREAD NORTHWARD
INTO SOUTHWEST KANSAS THIS MORNING AS THE VIGOROUS UPPER LEVEL
TROUGH IN NEW MEXICO MOVES EAST INTO THE TEXAS PANHANDLE. THE HIGH
CLOUDINESS WILL THIN THIS AFTERNOON AS THE TROUGH PROPAGATES EAST
INTO CENTRAL OKLAHOMA. VERY COLD AIR ALOFT WILL PERSIST, AND
AFTERNOON HEATING WILL SUPPORT DEVELOPMENT OF HIGH BASED CUMULUS
CLOUDINESS AGAIN TODAY. COLD AIR ADVECTION BEHIND THE SUBTLE FRONTAL
BOUNDARY WILL CONTINUE THIS MORNING, AND THE LOW LEVELS OF THE
ATMOSPHERE WILL BE A LITTLE COOLER THAN YESTERDAY. TEMPERATURES AT
H7 ARE CONTINUING TO COOL, AND MID LEVEL INSTABILITY WILL BE NEARLY
ABSENT THIS AFTERNOON. AS A RESULT, THERE SHOULD BE FEW IF ANY HIGH
BASED SHOWERS THIS AFTERNOON. A SUBTLE UPPER LEVEL TROUGH IN EASTERN
UTAH WILL DROP INTO NEW MEXICO AND SOUTHEAST COLORADO THIS
AFTERNOON, AND THE ENTRANCE REGION OF THE JET STREAK WITH THE MINOR
TROUGH MAY PROVIDE SOME UPPER LEVEL DIVERGENCE IN SOUTHEAST COLORADO
LATE IN THE DAY. MODEL SOUNDINGS TO HAVE SOME SLIGHT MID LEVEL
INSTABILITY IN FAR SOUTHWEST KANSAS, AND A FEW VIRGA SHOWERS MAY
SPREAD FROM COLORADO INTO MORTON COUNTY BEFORE DYING THIS EVENING.
TEMPERATURES TODAY WILL BE SLIGHTLY COOLER THAN MONDAY AS A
CONSEQUENCE OF THE INVASION OF COOLER AIR LATE MONDAY AND MONDAY
NIGHT.

WEAK HIGH PRESSURE WILL COVER WESTERN KANSAS TUESDAY NIGHT, AND
WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE BOUNDARY LAYER
STABILIZES. DEWPOINTS IN THE 30S, MOSTLY CLEAR SKIES AND COLD AIR
ALOFT WILL FAVOR STRONG RADIATIONAL COOLING, AND TEMPERATURES WILL
DROP INTO THE 40S DURING THE NIGHTTIME HOURS.

THE UPPER LEVEL ANTICYCLONE IN SASKATCHEWAN WILL BUILD INTO THE
NORTHWEST TERRITORIES AS THE DEEP TROUGH NEAR 130W CLOSES OFF OVER
THE PACIFIC NORTHWEST ON WEDNESDAY. A TROUGH ROTATING AROUND THE A
LOBE OF THE POLAR VORTEX NORTHEAST OF HUDSON BAY WILL DIG SOUTH TO
JAMES BAY WEDNESDAY, AND THE NORTHERN PLAINS UPPER LEVEL LOW WILL
OPEN UP AND MOVE EAST WEDNESDAY AND THURSDAY. UPPER LEVEL RIDGING
WILL BUILD OVER THE CENTRAL PLAINS WEDNESDAY, AND ANOTHER DAY OF
MILD, QUIET WEATHER CAN BE EXPECTED IN WESTERN KANSAS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CDT TUE MAY 21 2013

MEDIUM RANGE MODELS INDICATE A WEAK UPPER LEVEL RIDGE OF HIGH
PRESSURE MOVING EAST OUT OF THE ROCKIES INTO THE WESTERN HIGH
PLAINS WEDNESDAY. ALONG WITH A GENERALLY WEAK FLOW ALOFT, FAIRLY
DRY CONDITIONS CAN BE EXPECTED ACROSS WESTERN KANSAS THROUGH LATE
WEDNESDAY AFTERNOON. HOWEVER, A FEW SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP IN A SOUTHEASTERLY UPSLOPE FLOW ACROSS EASTERN
COLORADO WEDNESDAY AFTERNOON AS AN UPPER LEVEL JET CORE NOSES
NORTHEAST ACROSS NEW MEXICO. AN ISOLATED THUNDERSTORM DRIFTING OFF
THE FRONT RANGE INTO EXTREME SOUTHWESTERN KANSAS CANNOT BE RULED OUT
WEDNESDAY EVENING.

THE WEAK UPPER LEVEL RIDGE WILL DRIFT FURTHER EAST INTO THE CENTRAL
PLAINS THURSDAY AS A STRONG CLOSED OFF LOW DROPS SOUTHEAST ACROSS
THE PACIFIC NORTHWEST. THIS WILL OPEN MORE OF A SOUTHWESTERLY FLOW
ALOFT ACROSS THE WESTERN HIGH PLAINS INCREASING DYNAMIC SUPPORT,
INCLUDING INCREASING DIVERGENCE FIELDS. NEAR THE SURFACE, A BROAD
AREA OF HIGH PRESSURE ACROSS THE UPPER MIDWEST WILL HELP INFLUENCE
AN EASTERLY UPSLOPE FLOW ACROSS MUCH OF WESTERN KANSAS WHILE AN AREA
OF LOW PRESSURE SETS UP ACROSS THE INTERMOUNTAIN WEST CREATING
INCREASED LOW LEVEL CONVERGENCE ACROSS THE WESTERN HIGH PLAINS.
AS PLENTY OF MOISTURE ADVECTS BACK INTO THE REGION WITHIN THE
UPSLOPE FLOW, THE DEVELOPMENT OF THUNDERSTORMS WILL BE POSSIBLE,
INCLUDING ACROSS PORTIONS OF WESTERN KANSAS. CHANCES FOR
THUNDERSTORMS WILL CONTINUE EACH DAY FROM FRIDAY THROUGH THE
WEEKEND AS THE UPPER LEVEL PATTERN VARIES LITTLE THROUGH THE END
OF THE PERIOD.

RATHER SEASONABLE TEMPERATURES ARE EXPECTED WEDNESDAY AS THE WEAK
UPPER LEVEL RIDGING MOVES OF THE ROCKIES INTO THE WESTERN HIGH
PLAINS. AN EASTERLY UPSLOPE FLOW WILL SET UP ACROSS THE WESTERN
HIGH PLAINS AS SURFACE HIGH PRESSURE DRIFTS SLOWLY EAST ACROSS
THE NORTHERN PLAINS. THIS WILL KEEP GENERALLY COOLER AIR IN PLACE
WITH H85 TEMPERATURES RANGING FROM THE MID TEENS(C) ACROSS CENTRAL
KANSAS TO THE LOWER 20S(C) ACROSS EXTREME SOUTHWEST KANSAS. LOOK
FOR HIGHS UP INTO THE 70S(F) ACROSS CENTRAL KANSAS TO THE 80S(F)
IN FAR SOUTHWEST KANSAS WEDNESDAY AFTERNOON. COOLER TEMPERATURES
ARE EXPECTED THURSDAY AS THE SURFACE HIGH DROPS SOUTHEAST FROM THE
NORTHERN PLAINS INTO THE UPPER MIDWEST USHERING SLIGHTLY COOLER
AIR SOUTHWESTWARD INTO THE WESTERN HIGH PLAINS. HOWEVER, THIS
BREAK WILL BE BRIEF AS WEAK UPPER LEVEL RIDGING RE-ESTABLISHES
ACROSS THE CENTRAL PLAINS ALLOWING FOR A WARMING TREND LASTING
THROUGH THE WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1249 AM CDT TUE MAY 21 2013

VFR CONDITIONS WILL CONTINUE AT ALL TAF LOCATIONS THROUGH WEDNESDAY
MORNING. A DEEP UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO
SPIN OVER THE NORTHERN PLAINS TODAY, AND UNSEASONABLY COLD AIR ALOFT
WILL PERSIST IN THE CENTRAL PART OF THE COUNTRY. A VIGOROUS UPPER
LEVEL TROUGH IN CENTRAL NEW MEXICO WILL MOVE INTO CENTRAL OKLAHOMA
BY THIS EVENING, AND A WEAK UPPER LEVEL TROUGH IN UTAH WILL EXTEND
FROM SOUTHEAST COLORADO TO EASTERN NEW MEXICO BY SUNSET. SCATTERED
CLOUDS AOA 120 WITH OCCASIONAL BROKEN CLOUDS AOA 200 NEAR THE
OKLAHOMA BORDER CAN BE EXPECTED THIS MORNING. WITH AFTERNOON
HEATING, SCATTERED CUMULUS CLOUDS WITH BASES NEAR 080 WILL DEVELOP
AROUND 19Z. THE CUMULUS CLOUDS WILL DISSIPATE BY SUNSET.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  77  45  81  52 /  10   0   0  10
GCK  74  45  82  52 /  10   0   0  20
EHA  76  47  84  55 /  10  10  20  20
LBL  78  47  84  54 /  10  10  10  20
HYS  72  45  76  51 /  10   0   0  10
P28  77  49  82  55 /  10   0   0  10

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...RUTHI
SHORT TERM...RUTHI
LONG TERM...JJOHNSON
AVIATION...RUTHI