[BeauDodson]

The next storm system is already being well advertised. Figured I would start a thread on the specifics. GFS is showing a strong storm system coming out of the Plains and moving east into the Lakes. Several waves of low pressure are expected to ride up the boundary. There is already discussion among the National Weather Service Offices as to the impact this will have on the already serious flood situation.

This system appears (WAY too far off for details) to have a better severe weather threat with it...compared to this last one.

NWS Office in Paducah is already discussing the heavy rainfall threat.

Here is a moisture flux - there appears to be a connection from the Pacific, Gulf of Mexico, and Caribbean. If this holds true...same as last system. Plenty of moisture.
 marchmoisture.jpg (215.34K)
Number of downloads: 13

 avn_204_sfc.gif (55.35K)
Number of downloads: 3

and for good measure the 500mb map
 avn_500_wind_204.gif (70.12K)
Number of downloads: 2

I will be posting from my boat. :)

KPAH AFD - March 20th
THE INTERESTING TIME PERIOD RUNS FROM NEXT THURSDAY THROUGH NEXT
SATURDAY...AS THE ECMWF AND GFS STRONGLY DIVERGE IN THE TIMING AND
AMPLITUDE OF A WEST COAST SHORTWAVE /WITH THE BASE IN NORTHERN
CALIFORNIA/...AS IT IS PROGGED TO DEEPEN ACROSS THE WESTERN 1/2 OF
THE U.S. ON THURSDAY. BOTH THE ECMWF/GFS ELONGATE A TROUGH OF LOW
PRESSURE WITH TWO SURFACE LOWS OVER SRN IA AND SWRN OK. THE
PROBLEM LIES WITH THE TIMING /UP TO A 12-15 HOURS DIFFERENCE
BETWEEN THE MODELS/ AND THE INTENSITY OF THE AGEOSTROPHIC RESPONSE
/LIFT AND MOISTURE ADVECTION/ TO THESE CLOSED LOWS. AT THIS POINT
IN TIME...I HAVE CHOSEN TO GO WITH A SLOWER...MORE PROLONGED AND
FURTHER NORTHWARD SOLUTION FOR WEATHER/POP AND QPF. WITH THIS IN
MIND..I HAVE INTRODUCED A HIGH CHANCE CATEGORY FOR SHOWERS AND
THUNDERSTORMS STARTING THURSDAY AND EXTENDING THROUGH NEXT
SATURDAY. ALTHOUGH THIS SYSTEM WILL NOT BE THE SAME AS THE
PREVIOUS SYSTEM THAT PRODUCED ALL OF THE FLOODING...THE POTENTIAL
FOR 1-2 INCHES OF RAIN IS NOT OUT OF THE QUESTION OVER THE ENTIRE
PERIOD.

[BeauDodson]

From SPC

MS VALLEY DURING DAYS 6-7 TIME FRAME...BUT PROG
SOLUTIONS ARE TOO WIDELY DISTRIBUTED TO LEND ENOUGH CONFIDENCE FOR
OUTLOOK AREA ATTM.

[earthlight]

SVR EVENT APPEARS POSSIBLE OVER CENTRAL/SRN PLAINS
AND/OR LOWER-MID MS VALLEY DURING DAYS 6-7 TIME FRAME...BUT PROG
SOLUTIONS ARE TOO WIDELY DISTRIBUTED TO LEND ENOUGH CONFIDENCE FOR
OUTLOOK AREA ATTM.

..EDWARDS.. 03/21/2008

[joshMO]

It is certainly not what anyone in the Midwest needs. We'll see how consistent the GFS remains. THE ECMWF has somewhat of a similar setup, but is a little more progressive. Beau...where did you get the moisture flux graphic? It's a good one!

[BeauDodson]

GFS is already painting some high CAPE numbers.

www.wright-weather.com

Attached File(s)

•  avn_cape_156.gif (22.38K)
  Number of downloads: 6

[BeauDodson]

joshMO, on Mar 21 2008, 12:23 PM, said:

It is certainly not what anyone in the Midwest needs. We'll see how consistent the GFS remains. THE ECMWF has somewhat of a similar setup, but is a little more progressive. Beau...where did you get the moisture flux graphic? It's a good one!

That is from MetWise
See here
http://www.easternus...h...&hl=metwise

[BeauDodson]

...ROCKIES TO THE ATLANTIC COAST...

IN THE FLAT FLOW ACROSS THE NATION...GULF MOISTURE WILL BE
INITIALLY SLOW TO RETURN. THE ECMWF ENSEMBLE MEAN SUGGESTS A MEAN
FRONTAL ZONE SETTING UP FROM THE CENTRAL PLAINS TO THE MID
ATLANTIC REGION WED DAY 5 ONWARD. AFTER FILTERING OUT THE
OVERDEVELOPED WAVE FOR DAY 6 DEPICTED BY THE 00Z ECMWF OVER NEW
ENG...WE CAN EXPECT ADDITIONAL WAVE ACTION ALONG THE ZONE AS GULF
MOISTURE GETS BETTER. 12Z MODEL CONSENSUS SUGGESTS THAT THE AREA
WHICH HAS HAD RECENT HEAVY RAINFALL FROM ERN TX THRU THE OH VLY
COULD RECEIVE ANOTHER BOUT OF HEAVY RAINFALL THE LATTER PORTION OF
NEXT WEEK.

FLOOD
NCEP

[CUmet]

The GFS and the Euro are handling the trough a bit differently as usual. The GFS is faster with the trough, and it also seems to split the energy into a main piece that moves quickly to southern Canada, and another weaker piece that gets left behind. The Euro is about a day slower with the trough, and is more consolidated with it. Both models are too far to the north for there to be a widespread significant severe event, as depicted right now. However, the presence of strong ridging off the Southeast coast results in a high-quality air mass being available if the slower, more consolidated-trough solution verifies. Also, the low-amplitude, long-wavelength nature of this trough would ensure that the severe setup would be accompanied by very strong wind fields and steep lapse rates...hence the high CAPE outputs on the GFS.

In short, if the models start trending deeper with the trough and more consolidated, we're going to have to pay much closer attention.

[jhamps10]

NWS STL talking about this now:

UPPER FLOW PATTERN FLATTENS OUT BY EARLY NEXT WEEK WITH DRY WEATHER
CONTINUING. COOL HIGH PRESSURE WILL COVER THE REGION ON MONDAY.
COLD FRONT IS FORECAST TO MOVE INTO THE REGION. BY WEDNESDAY
EVENING, EXPECT THE FRONT WILL EXTEND FROM THE GREAT LAKES REGION
ACROSS CENTRAL MO INTO NORTHERN OK. FRONT IS THEN FORECAST TO STALL
ACROSS SOUTHERN MO ON THURSDAY WITH ZONAL FLOW ALOFT.

THE ECMWF AND GFS ARE FAIRLY SIMILAR IN FORECASTING A SIGNIFICANT
RETURN OF LOW LEVEL MOISTURE OVERRUNNING THIS FRONT. THE ECMWF IS
FORECASTING TREMENDOUS 850 MB MOISTURE CONVERGENCE/WARM AIR
ADVECTION INTO THE AREA THURSDAY NIGHT. THE COLD FRONT IS EXPECTED
TO MOVE ACROSS THE REGION FRIDAY NIGHT. THE ECMWF AND GFS HAVE THE
BACK EDGE OF THE RAIN AT SUNRISE SATURDAY ACROSS SOUTHERN
IL/SOUTHEAST MO. AT THIS POINT, EXPECT SEVERAL PERIODS OF HEAVY RAIN
ACROSS PORTIONS OF THE FORECAST AREA FROM WEDNESDAY THROUGH FRIDAY.
NOT EXACTLY WHAT WE NEED.

[Fred Gossage]

I'm not so sure that either the operational GFS or Euro have a good handle on this right now. In just the past three runs of the Euro, we've seen this trough base dig into New Mexico..... and then no further south than the Mid MS Valley. The GFS first introduced this system at 372 hrs on March 12th....and then trended southeastward. Sunday's runs had a BIG broad-based, negatively tilted trough emerging from the southern and central Rockies....with a low pressure area rapidly developing over Oklahoma, and 65+ solid tongue of dewpoints up to St. Louis.... The GFS ensembles are all showing a broad-based, negatively tilted trough over the Rockies at just under 180 hrs....and the past three or four runs have had the ensemble members converge on the timing more....and shift slowly southeast with each run. The ensemble mean average for the 576dm H5 height contour is just south of Birmingham, AL....with no ensemble member north of Lawrenceburg, TN....and some of the members as far south as the shelf waters of the northern Gulf. Last night's Canadian was much further south with the trough base than the op GFS...... the 12Z UKMET today at 144 hrs....was developing a sfc low over OK/TX.... and even the Japanese model had the trough over the Rockies digging further south than the GFS suggests. It appears also that around 180 hrs, the GFS pulled its trick of splitting the jet energy.... as we saw leading up to Jan 7th, Jan 10th, and Feb 5th. Significantly more questions than answers....... but it appears that a couple of the operational models may not exactly be the route to go....... and that there may be a lot of growing convergence in the ensembles and non-American operational models....on a potentially ominous solution for a large area from the Mid MS Valley, Ozarks, and Lower MS Valley.....over to the Ohio Valley, Tennessee Valley, and Gulf Coast states.

[joshMO]

I would agree Fred that the operational models have been all over the place of late with a solution. Nonetheless, the trend certainly needs monitored. Folks here in south Missouri are on edge as it is. This has been one crazy year so far.

[jhamps10]

joshMO, on Mar 21 2008, 08:32 PM, said:

I would agree Fred that the operational models have been all over the place of late with a solution. Nonetheless, the trend certainly needs monitored. Folks here in south Missouri are on edge as it is. This has been one crazy year so far.

yeah just what we don't need is more heavy rains.

[janetjanet998]

lets see if this will be the wettest year in IL history



so far

[tornadotony]

Gotta love this image.

 MARSforecast00z032208168h.PNG (140.55K)
Number of downloads: 33

[BeauDodson]

SPC a bit more bullish with each passing day...

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0339 AM CDT SAT MAR 22 2008

VALID 251200Z - 301200Z

...DISCUSSION...
PROGRESSIVE SHORTWAVE TRAIN IS PROGGED ALOFT...EMBEDDED WITHIN
STRONGLY ZONAL COMPONENT TO MEAN FLOW. THIS WILL SUPPORT MEAN LOW
LEVEL BAROCLINIC ZONE FROM MID-ATLANTIC WWD ACROSS CENTRAL PLAINS
AND GREAT BASIN...RIPPLED INTERMITTENTLY BY SFC LOWS ASSOCIATED WITH
INDIVIDUAL SHORTWAVE TROUGHS. MEANWHILE...GRADUAL MODIFICATION OF
GULF AIR MASS IS EXPECTED DAYS 4-5/25TH-27TH FOLLOWING DAY 2-3 SFC
FRONTAL INTRUSION. BY DAY-5 AND ESPECIALLY DAY-6/27TH-28TH...MREF
MEMBERS CONSISTENTLY AND REASONABLY PROG FAVORABLE MOISTURE S OF
WAVY FRONTAL ZONE AND FOR VARYING DISTANCES E OF CENTRAL/SRN PLAINS
DRYLINE...ALONG WITH WLY-SWLY FLOW ABOVE SAID DRYLINE AND PARALLEL
TO FRONT. THIS PATTERN ALONE...BUT ESPECIALLY IN CONSIDERATION OF
CLIMATOLOGY...INDICATES ONE OR MORE SVR EPISODES MAY OCCUR DURING
DAY 5-7/26TH-29TH TIME FRAME...SOMEWHERE FROM CENTRAL/SRN PLAINS EWD
TOWARD CENTRAL APPALACHIANS. HOWEVER...WIDE DISTRIBUTION OF BOTH
DETERMINISTIC MODELS AND MREF MEMBERS -- REGARDING TIMING/AMPLITUDE
OF SHORTWAVES ALOFT AND THEIR LOW LEVEL EFFECTS -- LENDS TOO MUCH
UNCERTAINTY ATTM TO OUTLINE THREATS FOR WELL-ORGANIZED SVR EVENTS ON
SPECIFIC DAYS.

..EDWARDS.. 03/22/2008

[ukrocks]

This going to be an interesting scenario, hopefully we can get some severe weather out of this one as well.

[Indystorm]

March 27 could get interesting for Missouri and Illinois areas. Here's the GFS Craven Svr. for 12z that day.

http://wxcaster4.com...IGSVR_120HR.gif time sensitive

[jhamps10]

PAH:

IN THE EXTENDED...GFS AND ECMWF ARE IN DECENT AGREEMENT ON THE
TIMING OF A WEAK COLD FRONT MOVING INTO THE REGION TUESDAY
NIGHT...THEN GRADUALLY MOVING BACK NORTH AS A WARM FRONT WEDNESDAY
INTO THURSDAY. BOTH MODELS SHOW A COLD FRONT THEN MOVING INTO AND
SLOWLY ACROSS THE REGION THURSDAY NIGHT INTO SATURDAY. OVERALL THIS
LEADS TO POPS EVERY PERIOD IN THE EXTENDED FOR TUESDAY NIGHT THROUGH
SATURDAY...AND CONTINUED WITH SLIGHT TO LOW CHANCE POPS THROUGH THIS
PERIOD. HIGHER POPS MAY WELL WORK THEIR WAY INTO THE LATE WORK WEEK
TIME PERIOD...BUT FOR NOW PREFER TO JUST KEEP AN EYE ON TIMING AND
STRENGTH OF THIS SYSTEM AND MAKE CHANGES AFTER COUPLE OF MORE MODEL
RUNS.

STL:
THE FRONT WILL BE THE FOCUS FOR SHOWERS/THUNDERSTORMS FROM MID WEEK
ON. WITH AN APPROACHING UPPER TROF, EXPECT THE FRONT TO LIFT
NORTHWARD ACROSS MUCH OF MO. BY SUNRISE THURSDAY, LOW PRESSURE IS
FORECAST TO BE CENTERED OVER CENTRAL NEBRASKA WITH FRONTAL BOUNDARY
EXTENDING EASTWARD ACROSS NORTH MO INTO NORTHERN KY. COLD FRONT IS
FORECAST TO CLEAR SOUTHEAST MO BY FRIDAY EVENING.

THE ECMWF AND GFS ARE FAIRLY SIMILAR IN FORECASTING A SIGNIFICANT
RETURN OF LOW LEVEL MOISTURE INTO THE REGION. THE GFS AND ECMWF
FORECAST SIGNIFICANT 850 MB MOISTURE CONVERGENCE/TRANSPORT INTO
THE AREA DURING THE DAY WEDNESDAY. BETTER MOISTURE CONVERGENCE/TRANSPORT
SHOULD SLIDE OFF TO THE SOUTHEAST ON THURSDAY. HOWEVER BOTH MODELS
THEN FORECAST THE MOISTURE TO COME BACK INTO OUR AREA WITH A
VENGENENCE BY FRIDAY MORNING.

[Indystorm]

The trend is significant not only for the possibility of svr but certainly with respect to additional or prolonged flooding in the affected regions.

[jhamps10]

Indystorm, on Mar 22 2008, 06:19 PM, said:

The trend is significant not only for the possibility of svr but certainly with respect to additional or prolonged flooding in the affected regions.

yeah, I looked at the ensambles, and they all show heavier precip, lasting longer here in this region. truely not a good sign at all,