Thursday July 2, 2015
Posted at 3:32 pm by Howard
Flash Flood Watch Today: http://forecast.weather.gov/showsigwx.php?warnzone=CAZ073&warncounty=CAC051&firewxzone=CAZ273&local_place1=17 Miles ESE Bodie CA&product1=Flash+Flood+Watch&lat=38.0781&lon=-118.739#.VZgAMGfbKUk
Saturday the 4TH of July:
An upper wave moving NW along the periphery of the upper high is tracking NW along the CA/NV border. Abundant moisture and instability will combine to bring a good chance of rainfall to Mono County, Later this AM and this afternoon. Not every part of Mono County will get heavy rain. However, the areas that do get thunderstorm’s, it is possibly because of the nature of this pattern to get torrential rains and flash flooding. So if you are outdoors today, have a plan to be able to seek shelter if necessary. A flash flood watch goes into effect at 11:00am this morning and ends at 8:00PM this evening. Precipitation should end this evening until Sunday afternoon when more storms are possible. However, there does not seem to be the focusing Sunday for as much heavy rain as today.
Scattered mainly late afternoon and evening thunderstorms are expected today with an uptick in action tomorrow afternoon due to wave moving from south to north.
It will be drier and a bit cooler next week with only isolated action.
Here is an important update from the Climatic Prediction Center today:
During the past several days, an extremely strong anomalous westerly wind burst, partly caused by tropical cyclone activity, developed over the equatorial western Pacific just west of the Date Line. This feature helped contribute to a very strong Phase-7 projection on the RMM MJO index, more than three standard deviations outside the circle. Dynamical models favor further amplification of the RMM Index, followed by gradual weakening, with the ECMWF continuing to depict further eastward propagation of the intraseasonal signal, while the GFS maintains a more stationary pattern.
Two additional tropical cyclones developed over the northwestern Pacific during the past several days, both within the high confidence formation shape depicted on the 30 June GTH Outlook. Tropical Storm Linfa is currently east of the Philippines, and may make landfall over Luzon over the next several days. Tropical Depression 11W formed near 170E and 10N, and is forecast to move westward or west-northwestward while intensifying. Dynamical models do not favor additional tropical cyclogenesis over the western Pacific, so the TC formation shape was removed from the updated outlook. The enhanced precipitation shape was modified based on the latest tropical cyclone track forecasts.
The National Hurricane Center is currently monitoring two systems that have a potential to develop over the southwestern portion of the East Pacific basin during the next 5 days. Additionally, the Central Pacific Hurricane Center is monitoring a system near 140W and 10N that has a low potential for development during the next 48 hours. For the updated GTH Outlook, a broad high confidence TC formation shape encompasses all three areas of potential development. A moderate confidence TC shape was maintained south of Hawaii for Week-2, and dynamical models, the MJO, and the El Nino base state all favor new potential cyclogenesis over the eastern Pacific during Week-2.
A moist South East flow with transient areas of upper divergence will continue through the holiday weekend. With that said, a drying trend will begin Sunday and continue into next week. There is some differences on the handling of the upper low off the central coast next week. Will it come inland; cut off and provide an area of upper divergence focused only it its NE quad. Will have to see. However, it will provide a lot of drying Sunday into Monday. The NWS has isolated action for early next week with a lot less humidity. Highs in the upper 70s and low 80s, lows in the low 50s.
The Madden Julian Oscillation is off the charts at the moment for July. This may be the only time of this intensity this time of the year since the early 1980s; which coincidently was one of the biggest El Ninos. 1982/9183. SEE: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmm.shtml
The system is responsible for modulating tropical convection as it moves west to east along the equator. At the moment the core of the enhanced state is located about 160E with its suppressed state over the Indian Ocean. It will be shifting east and weakening next week. Well see if there is any effect over the southern portion of the Hawaiian islands later next week. Eventually it will modulate Eastern Tropical Pacific, (East Pac) Watch out for TS Storm action moving along the Mexican coast around the middle of July.
About last night rains….
These MCVs are often missed on many initial analysis because of the scale but are extremely important in initiating new convection. and providing the upper divergence component of a conv/div couplet. Because these vort maxes appear to come and go so quickly, its is hard follow them from day to day with any continuity on the computer models. Only large scale systems such as ex-hurricane’s easterly waves and large MCSs get carried through on models from run to run with any continuity. The MCV is the most common upper level convective focus/ trigger mechanism around the periphery of the 4 corners high which are often mis-identified as moisture surges. If forecasters would just look at the SPC analysis they will see many areas of upper divergence that that cannot be resolved in the traditional synoptic scale vort analysis in many cases.
A mesoscale convective vortex (MCV) is a low-pressure center within an mesoscale convective system (MCS) that pulls winds into a circling pattern, or vortex. With a core only 30 to 60 miles (97 km) wide and 1 to 3 miles (4.8 km) deep, an MCV is often overlooked in standard weather analysis. But an MCV can take on a life of its own, persisting for up to 12 hours after its parent MCS has dissipated. This orphaned MCV will sometimes then become the seed of the next thunderstorm outbreak. An MCV that moves into tropical waters, such as the Gulf of Mexico, can serve as the nucleus for a tropical storm or hurricane.
Thunderstorm Action will continue this afternoon….with less action wednesday then increasing thunderstorm’s Thursday and Friday…..MJO rapidly intensifying over West Pac
Tuesday June 30, 2015
Posted at 9:41 am by Howard
As indicated earlier, thunderstorm action will be suppressed this afternoon. Much of the action will be over the southern sierra due to the configuration of the upper high. Very late this afternoon or early evening odds will increase somewhat. Better odds Thursday and Friday…
Check out the BMOM forecast; the Sigma is off the chart! That is not just convection associated with the MJO. It is a combination of that plus all the tropical convection and OLR associated with several tropical storms over the western pacific adding to the MJO to give you this!: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/bomm.shtml
Today weather shows a lot of high clouds…..
A moist SE flow will continue with another round of afternoon and evening Thunderstorms expected Tuesday. Some localized areas of heavy rain possible. The upper flow backs more from the east Wednesday and so it will be a bit drier with less thunderstorm action. Thursday into Friday will be both warmer with an increasing threat of Thunderstorms. Highs in Mammoth today will be warmer. So expect low 80s…..Expect warmer temps Wednesday into Thursday….Overnight lows again near 50.
The outlook for the holiday weekend is for a chance of afternoon and early evening thunderstorms with highs in the mid 80s. low in the upper 40s.
MJO rapidly intensifying over Western pacific. Westerly wind burst is in process as twin Cyclones work together on each side of the equator…..
Major Westerly Wind Burst in process…SEE: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/tlonhov_u850.shtml
This will be intensified by the two current Tropical Storms on each side of the Equator. Just like back in March!
SEE: Open this link then drag the globe to the right. Check out the two Cyclones at 160E just above and below the equator. This is adding to the strong westerly winds bursts and will combine with KW to add more fuel to the ENSO fire later…. http://earth.nullschool.net/#current/wind/surface/level/orthographic=-165.80,3.06,373
A Fire Weather Watch is Hoisted for the Sierra of Mono County because of the possibility of Dry Lightening Saturday afternoon through Sunday evening…..Wetter Storms are possible Later Sunday afternoon…..MJO is Amping as it goes into the Western Pacific….There will be a pattern change due to this action the week following July Fourth…But it may not effect the far southwest.
Saturday June 27, 2015
Posted at 10:39 am by Howard
A few sprinkles occurred yesterday afternoon in Mammoth Lakes. The most important thing that happened was that air mass modification occurred, as evidenced by 1. Dew points have risen from the mid 30s yesterday to the mid 40s this AM and Precipitable water has jumped up in our area up to about 3/4 of an inch. Looking at the SPC this AM, there is an 850MB-250MB convergence/divergence couplet over the Northern Owens Valley at this time. Also, radar is showing light precipitation over the Northern Owens Valley. This may not be reaching the ground yet. The HRRR rapid refresh model has rainfall for our area developing later this morning and increasing this afternoon. Thunderstorms and rain showers, some of which may be locally heavy at times are possible later this afternoon. High temps will be cooler today with upper 70s more likely than 80s. The fetch of monsoon moisture along with the combination of air mass modification and (couplet’s of upper divergence and surface convergence) will continue through tomorrow, mainly during the afternoon and evening hours. There may be a break Tuesday according to the new 12z Sunday WRF model….
As previously mentioned in the past two discussion’s…. MJO induced retrogression will occur later next week.
1. The First change that will happen is that the continental high will get pulled west over North Central CA and so expect another heat wave to develop this coming Wednesday into Friday. Highs may reach into the upper 80s in Mammoth Lakes by Thursday/Friday. In Bishop between 105 and 109 by Thursday thru Saturday. With the core of the upper high so close to us, daytime convection may be capped…will have wait to see.
By the way, Bishop broke another high temperature record Saturday of 106 breaking the old record of 105 set back in 2013. One more thing….There were 5 days in a row in 2013, between 6-27-2013 and 7-1-2013 that were records for Bishop. Although the next few day will be a bit cooler due to the increase in monsoon moisture, it may still remain in the low 100s. However, by Thursday, highs will be near record levels again.
Back to retrogression of the long wave upper ridge; this change is forecasted by all global models out to 145 west by early the following week. The models are struggling with the strength of the Continental High in its western location….. If the upper high remains strong enough, it will continue to be located west of the 4 corners area. If the upper trof is stronger as it digs south the continental high will be displaced east of the four corners area. The latter would result in a long wave trof off the west coast later the following week. If the latter happened…A dry SW flow would develop leading to a dry breezy pattern, for the Central Sierra with temps a bit cooler like upper 70s. If the upper southwest high wins out, then we’ll stay very warm with the chance of TSRWs through the period. Will update on this next week.
The only other concern is that the MJOs convective envelope will be well established in the eastern tropical pacific by the Fourth of July and that following week. It will no doubt be busy modulating tropical convection as it “Constructively Interferes” with the El Nino Base state, the week following the 4th of July. If by chance, we do get a long wave trof that sets up in the right spot over the Eastern Pacific, it may draw up one of the tropical systems and entrain it in the upper flow. Chances are best that any of that would benefit the desert southwest more than Southern CA, but stranger things have happened in the past. It is important to note that the MJO that is currently strengthening in Phase 6 is possibly in record territory for July with a sigma of close to +4 according to the ECMM. That is nearly at the end of the scale as a deviation from normal. What this may also mean is for the possibility of another strong westerly wind burst along the equator, over the western or central pacific. Can you imagine injecting more warm water into the Nino Basin 150 Meters under the surface that is already +5C to +6C?
Like the Dweebs said earlier….This is getting very scary! 😈
In the meantime, enjoy the thunderstorms the next two days and hope that no new fire starts occur today or Monday.
Dr Howard and the Dweebs…………..:-)
Saturday AM Update:
Expect Low to mid 80s to continue at resort levels this weekend with over night lows in the low 50s….Expect the addition of high cloudiness today Saturday with scattered high based thunderstorm’s later this afternoon. This is due to the channeling of high level moisture between the continental high to the east and an upper low to the west. The upper low is forecasted to shift north along the coast through the weekend eventually being absorbed by the westerlies early next week. Through the process, there is the possibility of nocturnal convection as the models show good 250MB divergence aloft Sunday afternoon over Mono County and at night over the west side of the sierra. Should this verify another 50 miles east we would have rain Sunday night. On the topic of divergence aloft, the new 12z run of the WRF shows 250 upper divergence over Mono County later this afternoon into the early evening hours as well as Sunday afternoon into that evening. As Sunday will be more moist, that afternoon and evening seems to be the best chance of wetting rainfall. The upper flow does back a bit from the southwest Monday. Not too sure if that will do much to lessen the chance for thunder. However, it quickly backs from the SSE by this coming Tuesday/Wednesday.
Outlook: Lots going on in this El Nino Summer.
Once again the global models bring significant retrogression to the Hemi pattern going into the holiday weekend. This acts first to retrograde the continental high to over Eastern CA Thursday and Friday for hot weather, the 2nd and 3rd of July, then weakens it a bit as the long wave upper high both retrogrades and redevelops and AMPS at 145west. This action will dig a strong short wave trof along 125west to the Pacific NW. In the process it picks up a small upper low in the mid latitudes, early that following week. Although the Dweebs will have to keep a eye on this anomalous pattern for the week just following the Fourth of July Holiday, it is unlikely that this trof will make it far enough south to bring weather to the high country. This is because the Continental high is so strong and acts to block it. However, at the same time we have a very unusual set up over the western pacific with a very strong MJO developing the next 7 days. This MJO no doubt to the Dweebs, is responsible for the retrogression forecasted in the westerlies and the Pacific NW trof the 5th and 6th of July. Additionally, this MJO as expected, has assisted in a major crash in the SOI to -50 yesterday and -41 today. So effectively the crash of the SOI weakening the easterlies has created a better environment for convection over the western pacific while the MJO enhances Upper Divergence over the western pacific tropics at the same time. Expect an enhanced state for the development of major typhoon action over the western pacific the next 2 weeks. PS. With a little luck there may be another strong westerly wind burst over the next week as a result…We’ll see.
All the global models now have the development of a tropical wave moving out of the ITCZ at this time as the convective envelope of the MJO moves into that area. The forecast is for the storm to move NW toward the Northern Mariana Islands by the Fourth Of July… This typhoon by then will continue to strengthen the following week. Another Tropical Storm will follow on its heals for week two. Now if these storms constructively phase with the westerlies late week 2, we’ll have another issue to deal with along the west coast later, but that is not in the long range forecast. The storms seem to be headed for the China Mainland.
Tropical Eastern Pacific:
The Convective Envelope of the MJO will move into the tropical central and eastern pacific week 2 and into Week 3. Above medium precip is forecasted to extend as far east as 110West. Tropical storm action will be enhanced for both the central and eastern tropical pacific week 2 and 3. As mentioned earlier, this may also enhance the SW monsoon the second week of July.
Dr Howard and the Dweebs…………………….:-)