000 
FXUS63 KMPX 060921
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
415 AM CDT TUE JUL 6 2004

.DISCUSSION...
FCST PBLMS FOCUS ON RAIN TODAY/TONIGHT ACRS CWA...THEN RAPID ATMS 
TRANSITION BY END OF SHORT TERM AS WE GRAVITATE TWRD PSBL SVR WX 
THREAT THUR NIGHT INTO FRI. SOME RECORD COOL MAX TEMPS ALSO THROWN 
INTO THE MIX.

CURRENT 88-D MOSAICS SHOWING TWO SEP VORT MAXS IN VERY SHORT PERIOD 
TO EACH OTHER...WITH EACH DOING ITS SHARE TO CARVE OUT FAIRLY 
IMPRESSIVE UPR TROF OVR MN/WI. ONE VORT MAX IN SRN WI LIFTING 
NORTHEAST TAKING ASSOCD RAIN SHIELD OVR FAR WRN WI WITH IT. THIS SYS 
DROPPED 1-3 OF RAIN OVR SCNTL MN LAST EVENING IN SRN TWO TIERS OF 
COUNTIES. SECOND S/W/VORT MAX ROTATING SOUTHEAST OUT OF SERN SD FOR 
A PATH ACRS NRN IA TODAY. 70KT JETLET UNDERNEATH SAID VORT...AND 
ANTICYCLONICALLY CURVED 90KT JET OVR ONT COUPLING UP TO PROVIDE 
LARGE AREA OF UPR DIV MAXIMA OVR NRN/WRN MN WHERE RAIN IS 
STEADY/INCREASING. IN BETWEEN TWO VORT MAXES...WHERE LIKELY SOME 
SMALL SCALE SUBSIDENCE IS TAKING PLACE...SCT SHRA MEANDERING AROUND 
AIMLESSLY...BUT ON THE INCREASE AS LARGE SCALE FORCING ACRS CWA IS 
ON THE UP AND UP. 

TODAY...DEVIL IN THE DETAILS. PLENTY OF FORCING CROSSING MUCH OF CWA 
FROM W TO E TODAY AND PATTERNED POPS MAINLY AFTER THE MAX IN H5-H3 
CONV-Q...AND THE PATH OF THE COUPLED UPR JET MAXIMA. LITTLE 
THERMALLY DRIVEN/THERMODYNAMIC LIFT WITH THIS SYS...AS MOST LIFT 
OCCURING KINEMATICALLY WITH VORT MAX AND UPR JET. STRONG PV ADV ALSO 
NOTED CROSSING CWA MAINLY THIS MORNING. THINK CURRENT VOID IN 
BETWEEN TWO S/WS WILL FILL IN WITH GENERAL -RA AND A LARGE RA 
SHIELD WL CROSS CNTL/NRN CWA ESP ALONG/NORTH OF HIGHWAY 12. SHOULD 
SEE WIDESPREAD 1/2 TO 3/4 AMTS WITH 1 AMTS FROM STC/AXN/LXL/JMR 
AREAS (NRN CWA)...AND 1/4 TO 1/2 ACRS CNTL CWA. AM A TAD CONCERNED 
WHERE THE SRN FRINGE OF THE RAIN SHIELD WILL BE AS THE AREA SOUTH OF 
THIS WILL SEE A DRASITCALLY BETTER DAY WITH ONLY SCT SHRA AND MUCH 
WARMER TEMPS...WELL..WARMER IN A RELATIVE SENSE. UNDER THE RA SHIELD 
TEMPS WL NOT MOV MUCH FROM NOW. LIKELY SOME RECORD LOW MAXES IN STC 
AGAIN (SET ONE YDAY) AND MOST AREAS ACRS CNTL MN. HINTS IN ETA THAT 
SOME INSTABILITY WL WORK INTO FAR SRN/SERN CWA IN SERN QUAD OF UPR 
TROF...AND LIGHT SOME ISO/SCT AFTN LO TOPPED TSRAS. CLEARING WONT 
BE FAR AWAY IN IOWA AND IF SOME CAN COME INTO SCNTL MN THREAT 
GREATLY INCREASES. DAY SHIFT WL NEED TO WATCH AS THERE IS A LOT OF 
SPIN ALOFT. SHIFT POPS W TO E ACRS CWA THRU DAY...TAPERING OUT WEST 
BY MID AFTN.

TONIGHT...HOLDING ONTO POPS IN THE EVE IN ERN 1/2 OF CWA AS TWO 
VORTS PHASE AND UPR TROF BECOMES MATURE AND SLOW. TONS OF CYCLONIC 
CURVATURE AND LL MOISTURE SO NO HURRY IN BREAKING OUT CLOUDS. 

WED...KEEPING ISO SHRA WORDING IN WRN WI NEAREST COLD POCKET AND 
CYCLONIC CURVATURE. TEMPS STILL VRY COOL FOR EARLY JULY...SOME 15 
DEG BLO NORMAL. SKIES WL WANT TO BREAK FROM WEST TO EAST IN AFTN AS 
S/W RIDGING AND HEIGHT RISES BEGIN TO MOV IN AHEAD OF DEVELOPING UPR 
TROF OVR NRN ROCKIES. SHOULD SEE MAINLY CLEAR SKIES WED NIGHT AND 
SOME PATCHY FG AS SFC RIDGE MOVS IN.

THU-THU NIGHT...MUCH DISCONNECT HERE BETWEEN ETA/GFS. LOW 
CONFIDENCE. ETA WANTS TO BRING INSTABILITY AND LEAD S/W EAST INTO 
NRN PLAINS MUCH FASTER THAN GFS. ETA DESTABILIZATION NOTHING SHORT 
OF DYNAMITE THU AFTN/NIGHT AS STONG MERIDIONAL LLJ CRANKS ON 
BACKSIDE OF H85 RIDGE AND AHEAD OF LEAD S/W. SOME OF THE HIER VALUES 
OF DIFF THETA-E ADV AND PURE THETA-E ADV IN MID TROP THAT I HAVE 
SEEN IN A WHILE OWING TO HOW QUICK THIS DESTABILIZATION WILL BE...AS 
WE TRANSITION THE UPR PATTERN FROM OUR RECORD COOL MAX TEMPS TDY 
INTO A PATTERN WHICH WL SUPPORT 85/70 PROFILES BY FRI. A WED NIGHT 
MCS OVR THE DAKS MAY HOLD TOGETHER LONG ENOUGH TO MAKE WRN MN IN THE 
MORNING ON THUR ON NOSE OF BUILDING CNTL PLAINS HOT PROD/THICKNESS 
MAX WITH VRY STEEP LAPSE RATES. THIS MCS...OR SOME MANIFESTATION OF 
IT...AND THERMODYNAMIC LIFT DRIVING IT...SEEMINGLY COULD HOLD 
TOGETHER ACRS CWA GIVEN HOW IMPRESSIVE THE MID LVL DESTABILIZATION 
IS. SO I DO BRING A BLOB OF CHC TSRA ACRS CWA IN BEST THETA-E ADV 
THRU DAY. AS STATED...LO CONFIDENCE...AS GFS IS ABOUT 12 HRS SLOWER 
AND SHOWS THIS TYPE OF SCENARIO FOR THUR NIGHT...AND NOTHING FOR 
THUR. AS AN ADDED NOTE...IF ETA VERIFIED AS WE SEE IT NOW...SEVERE 
MCS WOULD ERUPT IN ERN DAKS THUR EVE AND CROSS CWA ON NOSE OF STRONG 
CAP/50 KT LLJ...WITH ELEVATED THETA-E MAXIMA SITTING IN HEART OF 
CWA. STRONG (55KT) MID LVL FLOW AND ORIENTATION OF DEVELOPING WF 
SUGGEST A WIND JAMMER. THE START OF WHAT SEEMS WILL BE A VERY ACTIVE 
END OF WEEK ON THE EDGE OF CAP.

LONGER TERM...
NEW GFS CONTINUES THE THEME OF MAINTAINING A BROAD WEST TO SOUTHWEST 
FLOW PATTERN ACROSS THE GREAT BASIN INTO THE WESTERN GREAT LAKES 
REGION. FORECAST THICKNESS VALUES AVERAGE BETWEEN 568 AND 577 ACROSS 
THE MPX CWA DURING THIS PERIOD SO THIS CAN ONLY MEAN HEAT AND HIGH 
HUMIDITY. WITH THE THICKNESS VALUES FORECAST ALONG WITH THE 
SHARPNESS IN THE THERMAL RIDGE AT TIMES...CONVECTIVE TIMING WILL BE 
QUITE PROBLEMATIC AS AIRMASS CAPPING WOULD LIKELY OCCUR. GRIDS 
MODIFIED IN THE DIRECTION OF MORE HEAT AND HUMIDITY. 
 
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.

&&

$$

BINAU/WFO MPX