Summary: The sky looked to be clear with only a few high small white alto stratus clouds from time to time, during the morning, afternoon, evening, and night. The wind speeds looked to be calm. It felt cold, during the early and mid-morning. It felt very cool, during the late morning, afternoon, and early evening. It felt cold, during the late evening and early night. I believe there was a 0 percent chance for rain for the Houston, TX area, during the day. I did not see, or hear about any rain falling anywhere in, or near the Houston, TX area during any time of the day. I did not see, or feel any rain drops, where I was in the Houston, TX area, during anytime of the day.
Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
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000 FXUS64 KHGX 202332 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 532 PM CST Sun Dec 20 2020 .AVIATION [00Z TAF Issuance]... Not much change made to 18Z TAFS. With light winds and clear sky skies think conditions right for radiation fog as occurred last night. HRRR vsby progs suggest may be more southern sites for the more dense conditions...possibly CXO on south...but in any case should start be shallow. Not much of a signal in the SREF guidance but that may be due to shallow nature of fog. Will evaluate the fog threat further for the 06Z issuance...and update as necessary. 18 && .PREV DISCUSSION /Issued 355 PM CST Sun Dec 20 2020/... .SHORT TERM [Tonight through Monday Afternoon]... High pressure over Central Texas will drift eastward through the region setting the stage tonight for shallow fog to form under favorable radiational cooling conditions by midnight. Then thicken and may need dense fog advisories for the region after 3 am-ish. The thick fog should dissipate between 830-930 am Monday. A very pleasant day on tap Monday with light southwest and south winds and a few degrees warmer with highs in the upper 60s far west to lower to mid 60s east under sunny skies in the afternoon. 45 .LONG TERM [Wednesday Through Sunday]... The warming trend will continue as we approach Christmas Day, though the passage of a strong cold front on Wednesday will provide SE TX with cool and generally pleasant conditions for the holiday (however, we remain concerned about fire weather conditions...more on that in a bit). With onshore flow continuing to promote warm and moist advection, we should continue to see highs slightly above seasonable normals on Tuesday with most locations seeing the upper 60s to low 70s. By Wednesday, persistent increases in moisture will result in building cloudiness as a deepening surface low over the Northern Plains/Great Lakes brings an associated surface cold front through most of the central CONUS. There continues to be discrepancies amongst the global deterministic models regarding the timing of this feature`s arrival in SE TX. ECMWF & Canadian continue to favor a less progressive scenario with the boundary arriving in the northern counties later on Wednesday, while the GFS continues to depict the front already clearing the coastal waters by midnight on Thursday. The NAM solution is a relative middle ground between these two camps. As such, while we expect showers and storms to develop along and ahead of the front (though, less widespread and intense than in the previous fropa due to reduced instability and a relatively unfavorable position of the upper jet streak), the timing of the precipitation is less certain. I have slightly hedged my PoPs between these different scenarios given the continued uncertainty and maintain marginal chances into the early hours of Thursday. Northerly winds and clearing skies behind the front should prove favorable for a cool and dry (albeit gusty) Christmas Eve and Christmas Day. However, as echoed in the previous discussion by my colleague on the midnight shift, we continue to monitor the potential for elevated fire weather conditions in the wake of the fropa. The 12Z ECMWF has backed off on the aggressive single-digit dew points that its 00z counterpart depicted, though both the EC and GFS still show very dry conditions on Thursday and Friday. We will continue to monitor this situation closely in the coming days. Onshore winds will return by early Saturday as surface high pressure drifts eastward and another period of slightly warmer and more humid conditions should begin next weekend. With global models placing the area in the favorable left front quadrant of the dominant 300mb jet streak during this time, the potential for showers and storms will return on Saturday and Sunday. Cady .MARINE... Winds relaxing overnight as high pressure drifts through SETX tonight/Monday and into LA Tuesday. Southerly flow becomes the dominating issue Tuesday and dewpoints rise with windspeeds on the increase and Tuesday evening may need SCEC flags for southeasterly 15-20kt winds and seas building to 4-6 feet going into Wednesday. Strong cold front will be racing southeast and should cross the coast early Wednesday evening with strong CAA likely bringing wind gusts of at least 35 knots to the coastal waters and may peak closer to 45 knots. May need to hoist a Gale Watch with the Monday evening marine package. Winds start to let up during the afternoon Thursday but will still have a strong offshore flow into Thursday evening. Thunderstorms possible but iffy over the coastal waters with the frontal passage. 45 .FIRE WEATHER... Very dry air will stream through the area Wednesday night/Thursday in the wake of the strong cold front. May reach elevated fire weather conditions with RH values below 20 percent if current dewpoints hold...and this is question with much lower dewpoints in some of the guidance. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 37 66 42 67 55 / 0 0 0 0 0 Houston (IAH) 44 64 44 66 55 / 0 0 0 0 0 Galveston (GLS) 51 61 55 65 61 / 0 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ DISCUSSION...Cady NEAR TERM...45 SHORT TERM...45 LONG TERM...Cady AVIATION...18 MARINE...45 FIRE WEATHER...Cady
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