000
FXUS63 KDDC 210708
AFDDDC

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

...UPDATED SHORT TERM SECTION...

.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...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 357 PM CDT MON MAY 20 2013

AN UPPER LEVEL LOW PRESSURE SYSTEM WAS SITUATED OVER THE NORTHERN
PLAINS WITH A SHORTWAVE TROUGH WAS ROTATING AROUND THE SOUTHWEST
QUADRANT OF THE UPPER LOW OVER THE CENTRAL ROCKIES. THE UPPER LOW IS
FORECAST TO SLOWLY MOVE INTO THE UPPER MIDWEST THROUGH MIDWEEK WHILE
THE SHORTWAVE TROUGH MOVES OUT THROUGH THE TEXAS PANHANDLE INTO THE
RED RIVER VALLEY. THROUGH THE SAME TIME, ANOTHER UPPER LEVEL LOW
WILL BE DIGGING SOUTH ALONG THE WEST COAST OF CANADA INTO THE
PACIFIC NORTHWEST. THROUGH THE LATTER PART OF THE WEEK THE MIDWEST
LOW IS PROGGED TO PHASE WITH A NORTHERN STREAM SHORTWAVE OVER THE
GREAT LAKES REGION WHILE UPPER LEVEL RIDGING DEVELOPS OVER THE
NORTHERN AND CENTRAL PLAINS. THE MODELS SHOW A SHORTWAVE ROTATING
AROUND THE PACIFIC NORTHWEST LOW WHICH HELPS LIFT IT NORTHWARD INTO
SOUTHWEST CANADA BY THIS WEEKEND.

A FRONTAL BOUNDARY NOW EXTENDING SOUTH ACROSS THE PLAINS WILL
CONTINUE BE TO THE SOUTH OF WESTERN KANSAS THROUGH THE NEXT FEW DAYS
AND WILL BE REINFORCED AS HIGH PRESSURE BUILDS SOUTH FROM THE
NORTHERN PLAINS. FAIRLY QUIET WEATHER ALONG WITH MILD TEMPERATURES
CAN BE EXPECTED THROUGH THE MIDDLE PART OF THE WEEK. THERE WILL BE
SOME SMALL CHANCES FOR THUNDERSTORMS AS EARLY AS WEDNESDAY NIGHT AS
SOME LOW LEVEL MOISTURE BEGINS TO RETURN TO TO THE CENTRAL HIGH
PLAINS. THIS MOISTURE RETURN WILL CONTINUE THROUGH THE LATTER PART
OF THE WEEK WITH SURFACE DEWPOINTS INCREASING INTO THE 50S AND LOW
60S THROUGH LATE WEEK. LOW LEVEL UPSLOPE FLOW IS EXPECTED OVER
SOUTHWEST KANSAS TO THE NORTH OF THE FRONTAL BOUNDARY WITH THE LOW
LEVEL MOISTURE ADVECTING INTO THE EASTERN SLOPES OF THE ROCKIES.
THIS PATTERN COULD BE FAVORABLE FOR AFTERNOON THUNDERSTORMS
DEVELOPING OFF THE FRONT RANGE AND MOVING INTO WESTERN KANSAS
THROUGH THE EVENING AND NIGHTTIME HOURS. FOR NOW HAVE LEFT THE
ALLBLEND PRECIPITATION FORECAST INTACT FOR THURSDAY AND THURSDAY
NIGHT WITH CHANCE POPS ACROSS MUCH OF WEST CENTRAL AND SOUTHWEST
KANSAS. THE MODELS MOVE A SHORTWAVE TROUGH OUT OF THE ROCKIES INTO
THE NORTHERN PLAINS ON FRIDAY AND FORECAST DETAILS BECOME MORE
UNCERTAIN BY THEN. THE GFS CONTINUES TO KEEP SOUTHWEST KANSAS TO THE
NORTH OF THE FRONTAL BOUNDARY WHILE THE ECMWF SHOWS INCREASING
SOUTHERLY FLOW OVER THE HIGH PLAINS TO THE EAST OF A LEE SIDE TROUGH
DEVELOPING OVER EASTERN COLORADO AND A DRYLINE ALONG THE
KANSAS/COLORADO BORDER. INTO EARLY NEXT WEEK THE GFS HAS THE FRONTAL
BOUNDARY LOCATED OVER NEBRASKA WHILE THE ECMWF KEEPS IN TO THE SOUTH
OVER THE PANHANDLES. OBVIOUSLY A LOT OF UNCERTAINTY AS TO WHICH ONE
WILL BE RIGHT BUT TEND TO LEAN TOWARD THE ECMWF SOLUTION GIVEN THE
LOCATION OF THE UPPER LEVEL RIDGE.

&&

.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  78  49  81  52 /  10  10  10  10
GCK  75  47  82  52 /  10  10  10  20
EHA  77  48  84  55 /  10  10  20  20
LBL  79  49  84  54 /  10  10  10  20
HYS  74  48  76  51 /  10  10  10  10
P28  78  52  82  55 /  10  10  10  10

&&

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

$$

SYNOPSIS...RUTHI
SHORT TERM...RUTHI
LONG TERM...GERARD
AVIATION...RUTHI