Wednesday, March 22, 2017

Another Moisture Starved Weather System


As was the case with the last few systems, the forecast models have trended drier as this event neared in time. The plumes from the SREF system above are from the SPC and are for the 09 UTC run valid for TUS. The mean (black) is only 0.04" (vertical scale shown in increments of 0.025" - thus the second highest airport amount shown by green line is just 0.10").

For unknown reasons the MIMIC PW and the GEFS plumes have not been available since 12 UTC Monday morning this week.

The forecast below shows total precipitation forecast by the WRF-GFS at Atmo for period from 06 UTC last night through 11:00 pm MST tomorrow night. Almost a total miss for southern Arizona in the current model forecast. The forecast soundings still indicate a chance for shallow showers with the cold front, centered around 02:00 am early tomorrow, indicating a bit of hope remaining.

Bottom image shows a bit of early morning color on our placita.






Monday, March 20, 2017

Showers Possible Wednesday Night In Metro Area


Models forecast the possiblity of a moisture-starved event on Wednesday night as a rapidly weakening AR affects southern Arizona. The 00 UTC 20 March QPF plumes for TUS are shown above (from the GEFS). The operational GFS (blue) was one of the wettest forecasts at 00 UTC. The GEFS forecasts 100 % POPs for the airport Wednesday night into Thursday morning - current NWS forecast bit more conservative at 40%. Remember that the grid point forecasts used to extrapolate the GEFS to TUS are a fair ways off and all at higher elevations than the airport. For comparison the plumes from about the same lead time for the February 28th "event" are shown down at the bottom.


The 00 UTC WRF-GFS forecast from Atmo for total precipitation through 05:00 pm MST on Thursday (above) avoids the airport. However, the forecast sounding for TUS below is valid at 02:00 am on Thursday and shows some threat of showers or thunder during the night. The 06 UTC runs have become somewhat drier than were the 00 UTC forecasts.

So another iffy situation for us to watch.





Sunday, March 19, 2017

Wildfire Just West Of Boulder

Another day here with high temperatures above 90 F - enough is enough.


Wildfire burning this afternoon in Sunshine Canyon just to west of Boulder. More than a 1,000 homes have been evacuated today. Much snow in high country but Plains and Foothills very dry with gusty winds.




Friday, March 17, 2017

High Today 92 F

Today's high temperature reached above 90 F again - hitting 92 F. This morning the NWS posted the graphic below about the number of temperature records observed so far this March.


St. Patrick's Day 2017


Trump administration - we don't want or need the EPA - perhaps this is the future of D.C. water?

More smiles across the Pond in Dublin today than in D.C.




Thursday, March 16, 2017

Weather Returns Middle Of Next Week?

Has been very mundane weather, dominated by hot and dry, since February 19th with only rain being 0.02" here on the 28th. The current forecast from NWS this morning indicates high temperatures in middle 90s F for Saturday and Sunday, but by Wednesday next week the forecast is for chances of showers and thunderstorms, with 30% PoPs for at least 0.01" of rain at the airport. Have taken a far-ahead look at the 00 UTC forecast run of the WRF-GFS from Atmo last evening.


The 500 mb forecast above is valid at 11:00 am MST next Wednesday, March 22nd.  A cold, negatively-tilted short-wave trough is forecast to be sweeping across Arizona at that time. The forecast sounding for Tucson at 10:00 am that morning (below) is quite impressive wrt to the current very hot and dry soundings. There is CAPE and 20 mm of PW in the forecast skewT as another weakening AR sweeps by southern Arizona. The model's forecast of composite radar echoes valid at 11:00 am that morning (bottom) is also very impressive.

Of course, this is VERY far ahead and it will be interesting to see if the models prove more accurate than they were for the "event" of February 28th.





Tuesday, March 14, 2017

Big Storm Comes Together Over Notheast


Dangerous storm centered along the coast south of NYC with large precipitation shield (rain, sleet, and snow) covering New England. Impacts will dominate news today. Above shows regional radar at 1240 UTC and below shows Columbus Circle (south end of Central Park) about 5 hours ago. The flight misery map is at bottom.





Monday, March 13, 2017

Developing Winter Storm For Northeast


Above is view of State Street, downtown Chicago, this morning, and below is surface plot for Midwest a bit before 07:00 am MST. The surface low is centered a bit north of Columbia, Missouri, with a central pressure of only about 1016 mb. However, surface pressures are very high to the north and east of the low, providing strong gradients. The low is expected to deepen and impact the entire northeast of the country tonight and tomorrow - from DC to Maine. This storm has already been the main weather news over the weekend.



Air travel has been delayed, mostly in Chicago area (Misery Map above for 06:00 am), and current delays/cancellations shown below. Situation will be very much worse by tomorrow morning.