Tag Archives: indicates

That Model Indicates The Dry

An issue we are seeing on both the ECMWF and GFS model (image on the left from WeatherBell) for this event is the negative Pacific North American index, or PNA. This is a negative Arctic Oscillation. As it does so, the low pressure causing the negative PNA will also move east, bringing the unforgiving Arctic cold into the Plains and Midwest. The second piece is the Arctic Oscillation, or AO. However, I think the ECMWF has a better handle on the North Atlantic Oscillation, hence my thinking that the strongest cold will be confined to the Plains and Midwest-Great Lakes. This is a negative East Pacific Oscillation, or EPO. We see a battle ongoing between low pressure just south of Greenland (typical of a positive NAO) and high pressure to the north of Greenland (typical of a negative NAO). I want to go into the high pressure ridge building over the Gulf of Alaska.

Close, but not quite perfect (a little too much over the water). It does not take much time to acquire a tan in such weather. Many of them ride long-distances to jobs in all kinds of weather and they often have cars without the latest safety features. And the Weather Service requires the resources to be first rate, something it does not have at this point. Panama City historically receives light rainfall from January through April with an average ranging between one and three inches a month, according to the World Weather Organization. So if you have one miserable cold week followed by a blazing hot one, then your average for those two weeks may indeed be 70°. Doesn’t seem like it though. The 3 stars may mean that you are in the middle of positive and negative energy. Students may initially be more comfortable making predictions about fiction than nonfiction or informational text. Explore more with Yearly Predictions.

Remember, ensemble prediction is based on making many forecast simulations, with mean of the ensemble members tending to be more skillful than any particular forecast. Here is the120 hour forecast. Here is the average of the NWS GFS ensemble for 500 hPa and the variability amount the members (shading). The left panels show the ensemble forecast means and the right the single high-res deterministic run (both at 500 hPa). Shown above are 500 millibar height anomalies for Hour 240 of the ECMWF model run from Weatherbell. The top image shows the geopotential height at 30 millibars in the stratosphere for January 21, 1985, while the bottom image shows the ECMWF forecast at 30 millibars for 10 days out. Another way of looking at the uncertainty is using “spaghetti” diagrams, in which we show two height lines from each ensemble member. Note the eerie similarities between the two images. Note that Phases 8, 1 and 2 are most favored for cooler than normal weather in the central and eastern U.S., while Phases 4, 5 and 6 are favored for warmer weather.

While warmer sea surface temperatures indicate this could happen, the general trend this year is for tropical systems to not strengthen when they are supposed to. Statistical weather forecasting on the other hand takes a look at the weather of the past year and uses that data to understand the weather possibilities for the same time in the current year. Unfortunately, the situation for NWS high resolution numerical weather prediction is at least as problematic as the global model, with one stellar exception, the High Resolution Rapid Refresh (or HRRR). I honestly don’t think the situation is going to worsen and I’m not unduly worried when I sign for the furniture at 10.10 am. In the window was a sign saying stained glass classes offered. She left her wallet and identification behind and has never been seen or heard from again. Going with the trend, I anticipate a modest tropical system (meaning some rain, some wind, but NOT a tropical storm or hurricane) to impact either Texas or Mexico. Becoming increasingly windy and cloudy ahead of a band of rain, heavy at times, slowly spreading eastwards during the afternoon and evening.

Considering the polar vortex is going through heavy damage, the AO will be strongly negative and could bomb out to extreme negative values. So, calculate the Part of Death and then look for progressions and heavy transits to that degree. Because this system is at the 10 degree north line, I find it reasonable that, should movement continue west, climatologically the system would want to enter the Caribbean in a similar way in which Hurricane Ernesto did. At bottom is 00 UTC WRF-GFS forecast on 5.4 km grid for total precipitation through 5:00 pm on September 23rd. That model indicates the dry, trough to the north will preavil and keep Norma’s impacts to the south. The third item is the North Atlantic Oscillation (NAO). As far south as Agadir, the Atlantic coast is showered by over 200 mm of rain in winter. The various weather user communities and our congressional representatives must deliver a strong message to the NWS that enough is enough, that the time for accepting mediocrity is over. Here is the UW WRF output for early Saturday (remember the UW model is driven by the National Weather Service GFS model).