Weather Alerts For Ithaca, NE

There is a Marginal Severe Storm Risk for your location. Continue reading for today's outlook from the National Weather Service's Storm Prediction Center. -------------------- National Severe Storm Outlook THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL/EASTERN OKLAHOMA AND FAR NORTH TEXAS SUMMARY Severe thunderstorms with very large to giant hail (2 to 4+ inches in diameter), tornadoes, and scattered damaging winds are expected late this afternoon through tonight across parts of the southern Plains and ArkLaTex. A couple of strong tornadoes are possible. Synopsis A closed mid/upper-level low will remain centered over Manitoba and Saskatchewan today, while generally zonal/westerly mid-level winds persist over the southern Plains. A weak shortwave trough over the Southwest/southern Rockies this morning is forecast to eject eastward over the southern/central Plains by late this afternoon. At the surface, a convectively reinforced outflow boundary draped across north-central/northeast TX will shift northward into OK as a warm front today, while a low gradually deepens over northwest TX by late afternoon/early evening. Rich low-level moisture characterized by upper 60s to low 70s surface dewpoints will likely advance as far north as central into southeast OK through peak diurnal heating, with lesser moisture return farther north into northwest OK, KS, and southeast NE ahead of a cold front. A dryline will extend south-southwestward from the surface low across central into south-central TX. Southern/Central Plains into the ArkLaTex Strong to locally extreme instability (MLCAPE 2500-4000+ J/kg) is expected to develop along/east of the dryline in TX and south of the warm front in OK by peak afternoon heating. The presence of seasonably cool temperatures aloft and 7.5-8.5 C/km mid-level lapse rates will also support this very favorable thermodynamic environment. While large-scale ascent associated with the ejecting mid-level shortwave trough is not expected to be overly robust, it should be sufficient for at least isolated thunderstorm initiation by mid afternoon to early evening (around 20-23Z), especially near the warm front/dryline intersection in south-central OK. 40-50 kt of generally westerly effective bulk shear will support intense supercells, with multiple right/left splits likely. This activity will quickly intensify shortly after convective initiation, and very large to giant hail appears likely (2-4+ inches in diameter). The Enhanced/Moderate Risk areas have been expanded slightly in OK and north TX to account for deviant thunderstorm motions and the potential for multiple intense supercells to track east-southeastward along/near the warm front. A conditional risk for supercells remains apparent farther south along the length of the dryline in TX, although confidence in convective initiation remains low. Have maintained the Marginal Risk for this potential, with some expansion eastward in case isolated thunderstorms do initiate. Modest southerly low-level winds (around 20-30 kt at 850 mb) will be present through this evening across the southern Plains. Locally enhanced 0-1 km SRH will be present near the warm front with backed near-surface winds. This will support a threat for tornadoes with any right-split supercells that can remain surface based. A slight increase in the low-level jet this evening and presence of very strong to locally extreme buoyancy also suggests some threat for a couple of EF-2+ tornadoes. With time this evening, convection may grow upscale and pose a threat for scattered severe/damaging winds as it spreads southeastward into the ArkLaTex. Farther north in KS/NE, instability and low-level moisture is expected to remain weaker/more limited. But, some supercells/small clusters may eventually develop this afternoon and move east-northeastward given sufficient deep-layer shear for updraft organization. Isolated to scattered severe hail and damaging winds should be the main threat with this activity through mid evening before it eventually weakens. Lower Mississippi Valley/Central Gulf Coast A long-lived convective cluster has nearly moved offshore from the coast of AL/MS/LA. In its wake, a rain-cooled airmass exists across much of the lower MS Valley. This should hinder the development of much surface-based instability through early afternoon. Still, eventual re-destabilization should occur along/near the remnant outflow boundary. Isolated cells that may develop could pose some risk for hail and damaging winds.

Pollen Index: 10.4 Pollen Level: high Predominant Pollen: Birch, Ash and Mulberry. Based on past pollen counts and expected weather conditions, pollen levels for Sunday will be falling in the moderate range. This change results in part from rising humidity and expected precipitation in the afternoon and evening which tends to wash pollen out of the air. This reduction in pollen levels should be a relief to allergy sufferers.