Interesting Longer Range Forecast Situation

It is the first day of summer and, since the southwest US thunderstorm season is approaching, I plan to begin posting commentary on the blog again, after a long period of little activity.

I felt that the longer-term forecasts this morning were interesting because the GFS and ECMWF appeared, to me, to be presenting quite different forecasts, especially after 72 to 96 hours. The GFS predicts a dry pattern with the 500 mb anticyclone (now over MS and AL) building westward to be over NM/AZ by 144 to 168 hours. The ECMWF, on the other hand, predicts another significant cutoff at 500 mb developing off southern CA, much like the past several events. So, the ECMWF has the baroclinc, westerly cutoff doing battle with the subtropical high during much of the forecast period. This leads to strong southerly flow and the ECMWF dramatically increases moisture over AZ/NM after 72 hours. I suspect that that the ECMWF may be the model to pay attention to this week – based just on persistence over the last 8 weeks or so.

It is interesting that the NWS forecast offices in the southwest US seem to have somewhat different interpretations of what the two models are indicating for the coming week, as per:

TUS
BOTH THE GFS AND ECMWF INDICATE A TROUGH OVER THE EASTERN PACIFIC MAKING ITS WAY ONSHORE INTO SRN CALIFORNIA LATE WEDNESDAY INTO THURSDAY. BY EARLY FRIDAY THE DIFFERENCES BETWEEN THE TWO MODELS BECOME QUITE DIFFERENT WITH THE GFS SHOWING A BAGGY TROUGH MOVING NORTH OF THE AREA...WHILE THE ECMWF SHOWS A CLOSED LOW STILL OVER S CENTRAL CALIFORNIA. THUS...THE ECMWF IS MUCH WETTER THAN THE GFS.

ELP
MODELS IN GOOD AGREEMENT WITH UPPER RIDGE FINALLY EXTENDING WEST INTO CWA OVER NEXT 36 HOURS AS UPPER TROF OVER WEST COAST LIFTS NORTH OF THE RIDGE. THE WEST COAST TRO REFORMS TOMORROW AFTERNOON AND MAY CHANNEL ADDITIONAL MOISTURE INTO SOUTHERN PORTIONS OF CWA AND TEMPORARILY REDUCE CAP.

PHX
ECMWF/GFS ARE IN VERY GOOD AGREEMENT WITH RESPECT TO THE PROGRESSION OF SYNOPTIC-SCALE FEATURES THIS WEEK.

ABQ
MODELS WERE IN REASONABLE AGREEMENT INTO THURSDAY WITH REGARD TO THE POSITION OF THE RIDGE AND WHERE THE BEST MOISTURE WILL SETUP BUT THE GFS AND ECMWF CONTINUE TO DIVERGE SIGNIFICANTLY BY LATER THURSDAY AND INTO THE WEEKEND.

FLG
INCREASING MOISTURE FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE OVER TEXAS WILL STRENGTHEN AND PUSH WESTWARD...WHILE A LOW PRESSURE SYSTEM CUTS OFF WEST OF CALIFORNIA. THIS WILL OPEN THE DOOR FOR A STEADY AND GRADUAL MOISTURE INCREASE

So, we can look forward to a week of interesting changes, whatever they will actually prove to be, and can place our bets with our individual, long-term model of preference.

Bob