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Archive for January, 2012
Strong Positive Phase PNA Pattern to Develope over Eastern Pacific…..Coupled Air Sea Climate Models….Back Peddle on Break Through of Westerlies For Ca……Dry Pattern Likely to Continue……
Monday January 30, 2012
Pattern Change show Strong Amplification expected in the westerlies resulting in Strong Blocking ridge over west coast next weekend, north into Canada with high latitude bloc extending will into Arctic later during week 2. Although the southern branch splits main effects probably better for SW CONUS. So wet weather for Ca looking pretty unlikely for California…..well into February. Position of Upper Ridge/Block likely to bring period of very mild weather for February as well.
Here is the word from NCEP for this morning…..
1. The MJO is forecast to contribute to enhanced convection across parts of the western Pacific, northeast Australia and the South Pacific Convergence Zone (SPCZ) during the next two weeks. Suppressed convection is favored for the Indian Ocean over the period.
2. For the U.S., the current and forecast phases of the MJO favor a tendency for a “positive PNA pattern” in coming weeks with enhanced chances for below-normal temperatures in the eastern U.S..
3. “Later” as the MJO enters the western hemisphere, there is a tendency for stronger jet streams to develop. “There is potential for a ridge in the west to be undercut”, returning wet conditions to the west, and also enhanced moisture is more likely across the southern tier of the U.S.
The net results…
If we get the breakthrough it will take longer….Possibly around or beyond 2nd week of February.
The Dweeber…………………….:-)
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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.
Short Term and 7 day Forecast Continue Dry…..However Some Interesting Possibilities Developing With MJO Over The Next 7 to 15 Days
Saturday January 28, 2012
MJO…that elusive little inter-seasonal phenomena may play an important role in California weather, Beginning toward the end of the 1st week of February then develop stronger during the 2nd week of February.
See: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml
What is significant is that it projects strongly into the MJO “Phase Space 7” (EL NINO LIKE). The NCEP’s NCPE (Operational), NCPB, (Ensemble) and NCPO Bias corrected Ensemble are singing the same tune as well as some of the EURO Models. The Climate Prediction Center / NCEP update will be out early next week and should shed some light on the possibilities then…. Additionally…..the Dweebs expect Atmospheric angular momentum to soar for the first time this winter!! Will post the Global Wind Chart “GWO”…….. later next week
Additionally, the climate models are wetter for California (precip) with an under cutting 500mb signature with higher heights over the pacific NW Week 2. See: http://www.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/images1/wk1.wk2_20120127.NA.gif
Looking at the MJO Precip composites for the Month of February, there is a strong signal with a strong incursion of MJO into Phase Space 7 and above normal precipitation in Central California. It is several deviations above normal. Although it is forecasted to move into Phase Space 7 about the 9th of February, The Climate models bring wet weather earlier to the state. Could they be too fast? Phase space 7 is the pseudo El Nino State in which tropical convection moves east of the dateline. This would spin up the subtropical jet strengthen it and provide the means for strong undercutting of the highly amplified ridge that is expected to form next weekend. This is exciting stuff……:-) More Later>>>>>>>>
Here is the argumant against the idea of a strong enough jet to provide significant undercutting….
SSTA’s are -1.1C in the Nino 4 region. Although La Nina has been weakening in the Nino 1 and 2 region…region 3-4 is still -1.1C. This will work against any “strong tropical convection” trying to make it east of the dateline. Lets hope the Tropics will boil with convection from the dateline east as the inter-seasonal wave develops…strengthens in phase 6 then shifts east as it goes through phase 7. The AO has turned decisively negative.
Dr Howard and the Dweebs……………………………..:-)
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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.
Temps Cooler Friday and Seasonal Weather Saturday…..Looks Like Another Dry 5 to 7 Day Period Ahead…
Friday January 27, 2012
This is going to be a very brief update with a more detailed discussion over the weekend Saturday or Sunday….time permitting….
An upper ridge anchored to the southwest of Ca will shift eastward to the Rockies later next week possibly opening up the storm door (Slightly) by late Sunday some 10 days from now. Beyond that time frame is a pretty significant Arctic Airmass that is expected to drop south over the Ohio Valley. With the Ridge to the east of us, Arctic air well south into the east, there would be the possibility that a significant storm would track further south into Ca during that week 2 period (2nd week of February) It would be especially wet with high snow levels again…at least initially.
Last nights short wave provided a few showers over night due to a small band of moisture that got dragged along with it. Normally we would not receive anything from a system like that but it did encounter a little moisture along the way. Today will be breezy up over the crest with winds in the 50+mph class out of the ENE. Although there is not much 700mb support of wind….There is a pretty good surface gradient that is developing as a 1040mb high is slipping southeast toward SE Idaho/NE Utah. The next few impulses will come through early Monday Am and early Tuesday Am. There does not appear to be another pre-existing band to work on, however the new 12z run of the GFS had some 700mb moisture that once again gets drags south over Mono County Late Sunday night into Early Monday AM. The 500-1000mb thickness pool is colder with the 2nd short wave Tuesday Am, so early next week will be seasonal to cooler then normal.
More over the weekend………………………..:-)
The Dweeber…………………….:-)
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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.