Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/26/18

Area Forecast Discussion
National Weather Service Lake Charles LA
1000 PM CST Tue Dec 25 2018 .DISCUSSION... Wx map shows sfc high pressure over the East Coast, and low pressure beginning to intensify over AR/W TX this evening. Over our region, light southeast winds 5 mph or less to calm noted, with patchy fog reported at a few locations across C LA. For the forecast update, minor changes to show patchy to areas of fog after midnight through 6 am, mainly due to lowering ceilings. May at times become dense, but the confidence in the widespread dense fog to occur is less for this forecast than it was this morning. Reason being, various guidance is conflicting in the signal, HRRR showing no fog, with NAM12 showing pockets of dense fog at various times overnight. By daybreak, the winds will likely pick up in response to a tightening pressure gradient, mixing out any fog that would have developed by 9 AM. Other than adding marine hazards for Wednesday & Thursday winds/seas, remainder of the forecast remains unchanged. DML && .MARINE... Patchy to areas of fog will be possible this evening and overnight, but not expected to become widespread like this morning due to the expected increase in the pressure gradient and winds. Expecting the winds to increase near 20 knots or greater in 12 hours, and 25-30 knots by Wednesday evening/early Thursday morning. Due to this, raised Small Craft Advisories for the 0-60nm Coastal Waters from Intracoastal City to High Island beginning at 16z (10 AM CST) Wednesday, and all the 0-60nm zones and inland lakes/bays beginning at 00z (6 PM) Wednesday. DML && .PREV DISCUSSION... /issued 520 PM CST Tue Dec 25 2018/ AVIATION...Lower ceilings and visibilities will redevelop tonight and linger into Wednesday morning. Winds will increase earlier in the day tomorrow likely ending the reduction is vis earlier than this past morning. Winds will be southeast through the period. PREV DISCUSSION... /issued 501 PM CST Tue Dec 25 2018/ DISCUSSION... An unseasonably warm Christmas Day across the region despite ample cloud cover, with readings rising to around 70 in spots where the sun was able to peek through this afternoon. A cloudy but otherwise quiet night is expected, with the potential once again for fog development to occur. Probs not quite as high as they were last night, but still indicate possible advection fog beginning over the nearshore coastal waters this evening and subsequently spreading inland after midnight. For now will simply insert patchy fog wording and let subsequent shifts evaluate the need for any possible advisory. Robust upper trof currently over the Desert SW progged to continue EWD tonight and WED, with the pressure gradient tightening over the area between its attendant SFC low and high pressure over the Mid-Atlantic. Winds will near advisory criteria over the coastal counties and parishes by the afternoon. Increasing lift associated with a lead shortwave ejecting ahead of the main upper trof will result in an initial round of showers and thunderstorms spreading into the area tomorrow afternoon and evening, with a more robust and organized band of convection developing farther west into TX along/ahead of the SFC front. This more organized band of convection will begin to push into E TX after midnight, bringing an attendant risk of locally heavy rainfall and SVR TSTMS. Progged kinematic fields are quite impressive, with 0-1KM shear/helicity of 40-50 KT/400-500 m2/s2. Questions continue to surround degree of instability and the possible presence of a near SFC marine/stable layer limiting more discrete development ahead of the primary band. Nonetheless, a risk of hail/damaging winds along with embedded QLCS tornadoes will exist with the linear convection as it pushes through the area from late tomorrow night through the day on Thursday. Areawide rainfall totals of 1 to 3 inches are expected, with locally higher amounts possible. Have continued with the locally heavy rainfall wording for this period. Brief reprieve in rain is expected on FRI, but the SFC front is progged to stall over the NW Gulf, with one or more impulses ejecting through SW flow aloft brining about periodic rain chances for the weekend into early next week. 13 MARINE... Patchy fog is possible tonight as southeast flow continues to result in Gulf moisture streaming atop relatively cooler shelf waters. Southeast winds will increase and become gusty by tomorrow afternoon as an upper level storm system and associated surface low enters the western Plains. A small craft advisory will likely be needed. Winds gusts in excess of Gale force are possible by tomorrow night. The strengthening onshore flow will result in above normal tidal readings, with latest guidance indicating a coastal flood advisory may be needed for minor coastal flooding tomorrow night. Widespread showers and thunderstorms are expected Wednesday afternoon through Thursday night as this storm system lifts northeast into the upper Midwest and drags a surface front into the coastal waters. A modest northeast flow is expected in the wake of the front. Elevated rain chances will continue into the weekend as the front stalls out over the northwest Gulf. 13 && .PRELIMINARY POINT TEMPS/POPS... AEX 54 69 62 71 / 20 40 60 90 LCH 58 70 64 72 / 10 60 60 90 LFT 57 70 64 73 / 10 50 50 90 BPT 60 70 64 72 / 10 60 80 90 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...Small Craft Advisory from 6 PM Wednesday to noon CST Thursday for GMZ455-475. Small Craft Exercise Caution from Wednesday morning through Wednesday afternoon for GMZ430-432-435-455-475. Small Craft Advisory from 10 AM Wednesday to noon CST Thursday for GMZ450-452-470-472. Small Craft Advisory from 6 PM Wednesday to 6 AM CST Thursday for GMZ430-432-435. Small Craft Exercise Caution Thursday morning for GMZ430-432-435. && $$ PUBLIC...08
Area Forecast Discussion
National Weather Service Tucson AZ
313 PM MST Tue Dec 25 2018 .SYNOPSIS...Expect unsettled weather the rest of this week, with much cooler temperatures and periods of valley rain and mountain snow showers. The first system will bring widespread valley rain and mountain snow with gusty winds at times this evening into Wednesday. A colder system should arrive Thursday night into Friday with snow levels potentially near valley floors. The coldest nights of the season so far are expected this weekend with widespread sub-freezing temperatures even across the lower deserts. && .DISCUSSION...Isolated showers and thunderstorms were starting to develop across western Pima county around Ajo and Why this afternoon. Latest HRRR solution continued to suggest that this development will expand this evening, with the bulk of the precipitation occuring tonight into early Wednesday. That said, will keep the Winter Weather Advisory for snow accumulations posted this evening into Wednesday for elevations above 6000 feet. Otherwise, expect some improving weather conditions during the afternoon Wednesday through much of Thursday. This will be a brief break in the weather as another system brings more valley rain and mountain snow by Thursday evening into Friday. This next system will usher in much colder air setting the stage for the coldest nights of the season so far, and the potential for some snowflakes in the lower desert valleys on Friday. Unsettled weather may continue over the weekend as models continued to depict another system hanging around the region. Will keep the slight chance of precipitation in the forecast this weekend with below normal temperatures continuing. Thereafter, yet another system might impact the region for the start of the New Year. && .AVIATION...Valid through 27/00Z. Expect -SHRA to develop west of Tucson late this afternoon becoming widespread valley -SHRA and mountain -SHSN late this evening into Wednesday morning. Some occasional thunder will be possible in the storms west of Tucson this late this afternoon. MVFR conditions will be likely this evening into Wednesday afternoon especially in the presence of -SHRA and near the higher terrain. Winds this afternoon into the late evening will be out of the southwest at 15-22 kts with gusts up to 30 kts becoming southerly/southwesterly at 8-12 kts overnight into Wednesday morning. Wednesday afternoon winds will pick up again out of the southwest 12-18 kts with gusts to 25 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect widespread valley rain and mountain snow by this evening and continuing into Wednesday. Wednesday night into Thursday afternoon precipitation chances move to the White Mountains and along the Arizona/New Mexico border. Valley rain and mountain snow returns from Tucson eastward Thursday night into Friday. Over the weekend there is a slight chance of snow showers in the White Mountains, then potentially more valley rain and mountain snow by the middle of next week. Gusty southwest to northwest winds will prevail this afternoon and tomorrow afternoon. Otherwise, 20-foot winds will be terrain driven under 15 mph with the exception of Sunday which will see easterly winds. && .TWC WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 5 PM this afternoon to 5 PM MST Wednesday above 6000 feet for AZZ510>514. && $$ Visit us on Facebook...Twitter...YouTube...and at