Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0652 AM CST Fri Jan 10 2020
Valid 101300Z - 111200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS NORTHEAST TX...SOUTHEAST OK...NORTHERN LA...CENTRAL/SOUTHERN AR...
...SUMMARY... Widespread severe thunderstorms are likely across the southern Great Plains, mainly this afternoon and evening, spreading east into the Lower Mississippi Valley tonight. The most dangerous corridor for strong tornadoes and intense damaging winds should be centered on northeast Texas through northern Louisiana and southern Arkansas this evening through the overnight.
...South-Central States... An outbreak of severe thunderstorms is possible later today through tonight, with the most dangerous portion being tonight into early Saturday morning with a potential derecho and embedded strong tornado risk. Primary changes this outlook are to expand the Moderate Risk east across the Lower MS Valley and increase tornado probabilities for the evening/overnight period.
Vigorous shortwave trough near the AZ/NM border will shift east across the southern Great Plains through 12Z Saturday. A powerful 90+ kt jet at 500 mb is expected to emanate out of the base of the trough across east TX/OK. In response to this trough, the LLJ will increase throughout the period, more notably late in the period. Along the northwest periphery of low-level moisture advancement, multiple elevated supercells are expected to develop this morning across parts of western/northern OK into southern KS. A large hail risk is anticipated initially, but convection will have an opportunity to become surface based towards midday, though discrete cells should not be particularly common as a polar front sags into this region.
Farther south, strong boundary-layer heating is expected across west TX where 0-3 km lapse rates are forecast to approach 9 C/km. At the same time, strong mid-level height falls will spread across the Pacific cold front/dryline by peak heating, and thunderstorms should easily develop along the eastern edge of this steeper lapse-rate plume. Scattered supercells will evolve from east-central OK to north-central TX by 19-21Z, and farther south into south-central TX during the late afternoon. This activity will be strongly sheared and could produce very large hail early in the convective cycle. With time, multi-scale forcing will encourage consolidation into an extensive QLCS that should accelerate toward the Ark-La-Tex region during the evening. Damaging winds will likely be common along the QLCS with embedded mesovortex and supercell tornadoes.
Guidance such as the 00Z HRW-NSSL and HRW-ARW, along with the 06Z NAM and 11Z HRRR suggest that pre-frontal convection should develop out ahead of the QLCS across the Sabine Valley towards 06Z. As this convection spreads northeast across northern LA towards the Ark-La-Miss, the strong tornado potential should increase amid strengthening 0-1 km SRH of 300+ m2/s2 and upper 60s surface dew points. A couple long-track tornadoes are possible given fast storm motions but convective mode should be messy. Consolidation with the accelerating upstream QLCS should eventually occur, sustaining potential for widespread damaging winds with embedded significant severe gusts and tornadoes as it spreads toward the Lower MS Valley through 12Z.
Mine's not up yet!! Had to order the mounting pole, and it took a LOOOONNNNNGGGG time to get here.
Chain link fence top rails FTW.
I have two 4x4’s mounted in concrete with a 2x4 in the middle on a hinge at the bottom (so I can swing it down to do maintenance periodically) with the 2x4 screwed into both 4x4’s on both sides.
The poles are attached to that 2x4 and the 2x4 is fastened via screws and metal ties to the rest of the set up. The anemometer is mounted atop two 10’ top rails that are connected via the ever so slightly bigger chain link fence post. Its slid over the two 10’ poles where an equal amount (about 3’) is on each side of where the two 10’ poles meet. I don’t weld so I drilled holes and have nuts & bolts going through to the other side to prevent it from coming apart.
I have the whole set up on top of a small mound about 2 feet or so higher than the rest of the yard. I believe total height is around 24’.
I was finding only conduit or pipe. Didn't look over in the fencing section. We decided to order their kit, figuring it shouldn't take long to get here..... Wrong!
Ordered the 26th of Dec, got it on Monday. Finally got it mounted about 1900 last night. Currently seeing 71 deg-F, 90% Humidity and 29.92 in. pressure.
Hopefully I'll get time to reset the time and date, etc., on the monitor tonight.
Awesome! I love mine but the phone app is terrible for rainfall history. Each month the yearly rainfall resets and I can't figure out how to fix it. I've dug around the Davis Weatherlink app and the weatherlink website and can't figure out how to fix that issue. I'm sure you'll grow to love yours as they're very accurate. I've owned a few weather stations over the years and always struggled to achieve accuracy but this thing is a beast. Totally worth the money I spent on it!
I AM NOT A PROFESSIONAL - ALL OF MY POSTS ARE BASED ON MY OPINIONS ONLY.
Post by grisairgasm on Jan 10, 2020 11:47:50 GMT -6
And yes, I’ve never regretted the money for a Davis Vantage Pro II weather station. Can’t recommend it enough. It’s the real deal . Only maintenance for me is cleaning the rain bucket every couple of months.
So, I'm gathering that NOLA's upcoming severe weather threat this week is not a big rainmaker (tornadoes, winds and lightening, but not as much a rain threat). Of course, I say that knowing that it doesn't take much rain around here for it to be an issue. Am I right?
Last Edit: Jan 10, 2020 12:55:24 GMT -6 by plankton
Post by grisairgasm on Jan 10, 2020 14:21:27 GMT -6
Yeah, it appears the severe threat will end here early Saturday afternoon. There will be areas of heavy rain before and with FROPA but should be moving East even though the line may be oriented in a “train” North / South pattern. Looks like the front actually backs up starting Sunday and hangs around causing multiple periods of rain particularly early in the week. I have not really looked but I don’t believe there is any flooding risk or severe at this point. However, anytime you have a warm front stalled in the winter down south it’s a possibility but not likely with this system. Somebody correct me if I’m wrong.
Post by grisairgasm on Jan 10, 2020 14:54:02 GMT -6
The Storm Prediction Center (SPC) is all over this event as usual. They are flat out amazing. I believe it may be one of the best entities in the NWS system. I’m sure glad I’m not in North Louisiana and elsewhere overnight. Scary.
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The southern sector of this event is about to start rolling...(note the graphic for them..."GIANT HAIL")
Mesoscale Discussion 0016 NWS Storm Prediction Center Norman OK 0252 PM CST Fri Jan 10 2020
Areas affected...Portions of central into south-central TX
Concerning...Severe potential...Watch likely
Valid 102052Z - 102245Z
Probability of Watch Issuance...80 percent
SUMMARY...Severe threat is increasing this afternoon. Scattered large hail and perhaps isolated giant hail will be possible, along with strong/damaging winds. A tornado or two may also occur. Watch issuance is likely in the next hour or so (by 22Z / 4 PM CST).
DISCUSSION...Strong surface pressure falls around 2.5-3.5 mb in the past two hours are occurring across parts of central TX this afternoon. This is indicative of large-scale ascent associated with a strong mid/upper-level jet overspreading this region. Storms will likely erupt along a pre-frontal confluence zone in the next couple of hours as this pronounced ascent erodes a low-level cap. As this convection moves eastward over parts of central TX and vicinity through the remainder of the afternoon and this evening, it will encounter a moderately to strongly unstable airmass. MLCAPE of 1500-2500 J/kg will likely persist as steep mid-level lapse rates overlie surface dewpoints generally in the lower to mid 60s F. RAP forecast soundings and recent VWPs from KGRK/KEWX show rapid strengthening of the low/mid-level winds, along with some veering. This is supporting 50-60 kt of effective bulk shear, which will be more than sufficient for supercells.
Scattered large hail should be the primary severe threat with initial semi-discrete development. Some of this hail could become very large (2+ inches in diameter) given the degree of instability and shear present. Strong to damaging winds may become an increasing concern later this evening as storms eventually congeal into a cluster/line along an eastward-moving cold front. A tornado or two also appears possible, mainly with the initial supercells, although a strong low-level jet and related shear will tend to shift slowly northeastward and away from central TX through the evening. Watch issuance will likely be needed within the next hour or so as storm initiation becomes increasingly probable.