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Hurricane CRISTINA Forecast Discussion Number 10

2014-06-12 04:36:34| National Hurricane Center (East Pacific)

Issued at 800 PM PDT WED JUN 11 2014 000 WTPZ43 KNHC 120236 TCDEP3 HURRICANE CRISTINA DISCUSSION NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032014 800 PM PDT WED JUN 11 2014 Cristina continues to gain strength. The eye has become more distinct in recent satellite images, and cloud tops surrounding the center have cooled. In addition, the overall cloud pattern appears more symmetric than earlier this afternoon with better organized banding features. Dvorak classifications were 4.5/77 kt from both TAFB and SAB at 0000 UTC. Since that time, the eye has become surrounded by white cloud tops on the Dvorak IR curve, which suggests that Cristina's winds have increased to at least 85 kt. The hurricane still has another day or so to gain additional strength, since the vertical shear is expected to remain quite low while Cristina lies over warm 29 C waters. In 2 to 3 days, the environment is expected to become less favorable as the cyclone begins to move over cooler water and into westerly shear. These hostile conditions should cause weakening, and Cristina is expected to become a remnant low in about 5 days. The NHC intensity forecast is a little higher than the previous one in the short term to account for the observed strengthening trend, but is otherwise unchanged. The eye of the hurricane has been wobbling, but a smooth initial motion estimate is 290/5. A slightly faster west-northwestward to northwestward motion is forecast during the next few days while Cristina moves along the southwestern periphery of a mid-level high pressure system. By the end of the forecast period, the weakening storm is expected to turn back toward the west steered by the low-level flow. The NHC track forecast is nudged to the north of the previous one trending toward the latest GFS and ECMWF consensus. FORECAST POSITIONS AND MAX WINDS INIT 12/0300Z 16.0N 105.8W 85 KT 100 MPH 12H 12/1200Z 16.4N 106.7W 95 KT 110 MPH 24H 13/0000Z 17.1N 108.1W 95 KT 110 MPH 36H 13/1200Z 17.9N 109.4W 90 KT 105 MPH 48H 14/0000Z 18.7N 110.6W 80 KT 90 MPH 72H 15/0000Z 19.6N 112.3W 60 KT 70 MPH 96H 16/0000Z 20.2N 113.6W 45 KT 50 MPH 120H 17/0000Z 20.5N 115.5W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Cangialosi

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Hurricane CRISTINA Forecast Discussion Number 9

2014-06-11 22:39:04| National Hurricane Center (East Pacific)

Issued at 200 PM PDT WED JUN 11 2014 000 WTPZ43 KNHC 112038 TCDEP3 HURRICANE CRISTINA DISCUSSION NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032014 200 PM PDT WED JUN 11 2014 An intermittent eye feature has been noted in both conventional and microwave satellite imagery today, and Dvorak intensity estimates have steadily increased as a result. However, a 1653 UTC AMSU pass indicated that the 15-20 nmi diameter eyewall was open to the east and that it was completely detached from any convective bands, suggesting that the hurricane is probably not quite as strong as the T4.5 satellite intensity estimates from TAFB and SAB are indicating. Therefore, the initial intensity estimate is set to 70 kt. Cristina is now moving at a fairly steady motion of 280/05 kt. The model guidance remains consistent on the hurricane moving westward through tonight, followed by a west-northwestward motion beginning on Thursday and continuing through 72 hours. After that, a weakening Cristina is forecast to turn more westward as the cyclone gradually becomes more vertically shallow as it encounters unfavorable atmospheric and oceanic conditions, and gets steered by the low-level easterly flow on the south side of broad ridge of high pressure. Although the new model tracks still diverge significantly at Days 4 and 5, the GFS and GFS-Ensemble models have nudged their tracks a little farther west and closer to the previous NHC forecast. As a result, the official forecast track is similar to the previous one, and remains a little to the left of the consensus model TCVE due to the right-bias of the GFDL-member. Intermittent intrusions of dry mid-level air should continue to interrupt the development of persistent eyewall convection for the next 36 hours or so. However, given that Cristina will still be over near 29C SSTs and in an extremely low shear environment, those conditions should allow for at least gradual strengthening during that time. Around 72 hours or so, environmental and oceanic conditions are expected to become increasingly unfavorable, which should combine to produce steady weakening, especially by 96 hours and beyond. FORECAST POSITIONS AND MAX WINDS INIT 11/2100Z 15.6N 105.2W 70 KT 80 MPH 12H 12/0600Z 16.0N 106.4W 75 KT 85 MPH 24H 12/1800Z 16.6N 107.8W 80 KT 90 MPH 36H 13/0600Z 17.3N 109.2W 85 KT 100 MPH 48H 13/1800Z 18.1N 110.5W 75 KT 85 MPH 72H 14/1800Z 19.1N 112.4W 60 KT 70 MPH 96H 15/1800Z 19.5N 113.9W 45 KT 50 MPH 120H 16/1800Z 19.9N 115.3W 30 KT 35 MPH $$ Forecaster Stewart

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Hurricane CRISTINA Forecast Discussion Number 8

2014-06-11 16:53:15| National Hurricane Center (East Pacific)

Issued at 800 AM PDT WED JUN 11 2014 000 WTPZ43 KNHC 111452 TCDEP3 HURRICANE CRISTINA DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032014 800 AM PDT WED JUN 11 2014 After an overnight period of strengthening, conventional and microwave satellite imagery suggest that Cristina's intensity has leveled off. Recent SSMI/S and TRMM overpasses indicated a low- level eye feature, but the mid-level eye is no longer evident. The cyclone again appears to have ingested dry mid-level air, which has eroded the convection in the western semicircle. The initial intensity of 65 kt is based on consensus Dvorak satellite intensity estimates of T4.0/65 kt from TAFB and SAB. After a brief jog to the west-southwest, Cristina appears to have resumed a westerly motion of 275/05 kt. Other than to make just a tad right-of-track adjustment due to the initial position, the NHC official forecast track is just an update of the previous advisory track. Cristina is expected to move westward today, followed by a west-northwestward motion around the southwestern periphery of a deep-layer ridge in the 24- to 72-hour period, a scenario which most of the reliable models strongly agree on. After that, however, the models diverge significantly with the GFS, GFS Ensemble, NAVGEM, HWRF, and GFDL models taking a stronger Cristina more northward, whereas the ECMWF and UKMET weaken the cyclone fairly quickly and move it more westward. Given that the official intensity forecast is calling for a weaker and smaller tropical cyclone by 96 and 120 hours, the official forecast at those times is roughly an average of the ECMWF and GFS models, which shows a weaker and more vertically shallow cyclone moving west-northward to westward. Cristina has consistently been intensifying at night during the convective maximum period, which seems likely to continue for another 24-48 hours. However, the cyclone will still be battling occasional intrusions of dry mid-level air for the remainder of the forecast period, especially after 72 hours, so only gradual intensification is expected. After day 3, increasing southwesterly vertical wind shear and SSTs cooler than 26C are expected to induce steady weakening. The NHC intensity forecast is similar to the previous advisory, and closely follows the consensus intensity model ICON. FORECAST POSITIONS AND MAX WINDS INIT 11/1500Z 15.4N 104.8W 65 KT 75 MPH 12H 12/0000Z 15.7N 105.9W 70 KT 80 MPH 24H 12/1200Z 16.2N 107.3W 75 KT 85 MPH 36H 13/0000Z 16.9N 108.6W 80 KT 90 MPH 48H 13/1200Z 17.7N 110.0W 75 KT 85 MPH 72H 14/1200Z 19.0N 112.3W 60 KT 70 MPH 96H 15/1200Z 19.5N 113.8W 45 KT 50 MPH 120H 16/1200Z 19.9N 115.1W 30 KT 35 MPH $$ Forecaster Stewart

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Hurricane CRISTINA Forecast Discussion Number 7

2014-06-11 10:44:27| National Hurricane Center (East Pacific)

Issued at 200 AM PDT WED JUN 11 2014 000 WTPZ43 KNHC 110844 TCDEP3 HURRICANE CRISTINA DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032014 200 AM PDT WED JUN 11 2014 Cristina continues to intensify. The cyclone consists of a small central dense overcast in geostationary satellite imagery with cold-topped convection to -80C in the northern semicircle. There have been faint hints of eye or warm spot during the past several hours, and a 0329 UTC TRMM overpass showed a closed low- to mid- level ring of convection surrounding the center. Satellite classifications from TAFB and SAB supported an intensity of 60 kt at synoptic time. However, the initial intensity estimate is increased to 65 kt, based on UW-CIMSS ADT values now to 4.5/77 kt and the persistence of an eye feature that has warmed slightly and become better defined. The cyclone has been moving south of due west in response to a strong mid-level ridge over northwestern Mexico, but the heading appears to have recently become more westerly. The ridge is forecast to either remain in place or shift slightly eastward during the next few days, which should cause the track of Cristina to gradually bend west-northwestward. The track guidance is in generally good agreement on this scenario, but small differences in the location of the ridge over Mexico lead to slightly different motion headings. The ECMWF maintains the center of the ridge a bit to the west of the GFS and other models, resulting in a solution on the southern side of the guidance envelope. The NHC track forecast is adjusted a hair to the left of the previous one in the direction of the ECMWF, which has continued to correctly forecast a more southern track. The environment in which Cristina is embedded remains ideal for intensification. The cyclone is located underneath a mid- to upper- level ridge axis and over very warm waters. The inner core structure has also become better defined, with the closed ring seen in microwave imagery signaling that rapid intensification is a possibility. The NHC forecast is adjusted upward in the short term based on current trends, and thee is some potential for Cristina to become stronger than forecast. In about 60 hours, Cristina should encounter increasing southwesterly shear associated with an upper-level trough extending southwestward from California coast and should reach markedly cooler waters in about 4 days. This should result in a pronounced weakening trend at the end of the forecast period and perhaps a quick demise. The NHC intensity forecast is close to the multi-model consensus through 72 hours and near the LGEM after that time. FORECAST POSITIONS AND MAX WINDS INIT 11/0900Z 15.2N 104.1W 65 KT 75 MPH 12H 11/1800Z 15.3N 105.2W 75 KT 85 MPH 24H 12/0600Z 15.7N 106.6W 80 KT 90 MPH 36H 12/1800Z 16.4N 108.0W 85 KT 100 MPH 48H 13/0600Z 17.2N 109.4W 85 KT 100 MPH 72H 14/0600Z 18.6N 111.8W 70 KT 80 MPH 96H 15/0600Z 19.2N 113.5W 55 KT 65 MPH 120H 16/0600Z 19.6N 114.7W 35 KT 40 MPH $$ Forecaster Kimberlain

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Tropical Storm CRISTINA Forecast Discussion Number 6

2014-06-11 04:34:01| National Hurricane Center (East Pacific)

Issued at 800 PM PDT TUE JUN 10 2014 000 WTPZ43 KNHC 110233 TCDEP3 TROPICAL STORM CRISTINA DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032014 800 PM PDT TUE JUN 10 2014 Cristina is intensifying this evening. The compact central dense overcast has become more circular, and hints of an eye have been apparent in geostationary satellite images. The initial intensity is increased to 55 kt, in agreement with unanimous Dvorak classifications of 3.5/55 kt from TAFB, SAB, and UW-CIMSS ADT. Although the curved bands beyond the inner-core region remain fragmented, a considerable amount of lightning has been occurring in a rain band located about 120 n mi to the south-southwest of the center. Recent research has documented that lightning in the outer bands of the tropical cyclone circulation is often a precursor of significant intensification. The only apparent factor that could limit strengthening during the next couple of days is mid-level dry air, which has been an issue for Cristina during the past day or so. In about 3 days, Cristina is expected to move into an environment of stronger southwesterly shear and over cooler waters, which should end the strengthening trend and cause the cyclone to weaken. The NHC intensity forecast is slightly higher than the previous one, and is pretty close to the intensity model consensus IVCN. Cristina has wobbled a little south of due west during the past 6 hours, and the latest initial motion estimate is 265/5. A westward to west-northwestward motion is forecast during the next day or so while the cyclone remains on the south side of a mid-level ridge over northwestern Mexico. After that time, a turn to the northwest is predicted when the ridge weakens and shifts eastward. The NHC track forecast is an update of the previous one, and close to a consensus of the GFS and ECMWF models. FORECAST POSITIONS AND MAX WINDS INIT 11/0300Z 15.2N 103.9W 55 KT 65 MPH 12H 11/1200Z 15.4N 105.0W 65 KT 75 MPH 24H 12/0000Z 15.8N 106.4W 70 KT 80 MPH 36H 12/1200Z 16.5N 107.7W 75 KT 85 MPH 48H 13/0000Z 17.2N 109.0W 75 KT 85 MPH 72H 14/0000Z 18.7N 111.5W 70 KT 80 MPH 96H 15/0000Z 19.6N 113.5W 55 KT 65 MPH 120H 16/0000Z 20.0N 115.5W 35 KT 40 MPH $$ Forecaster Cangialosi

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